Ala, Asn(10) --> Ala or Gln, Leu(11) --> Arg,
Gly(12) --> Ala, His(14) --> Trp) enhanced activity 2-10-fold. These effects were
additive, as [Ala(3),(10,12),Arg(11), Trp(14)] rPTH(1-14)NH(2) was 220-fold more
potent than rPTH(1-14)NH(2) (EC(50) = 0.6 +/- 0.1 and 133 +/- 16 micrometer,
respectively). Native rPTH(1-11) was inactive, but [Ala(3,10), Arg(11)]rPTH(1
11)NH(2) achieved maximal cAMP stimulation (EC(50) = 17 micrometer). The modified
PTH fragments induced cAMP formation with hP1R-delNt in COS-7 cells as potently
as they did with hP1R-WT; PTH(1-34) was 6,000-fold weaker with hP1R-delNt than
with hP1R-WT. The most potent analog, [Ala(3,10,12),Arg(11), Trp(14)]rPTH(1
14)NH(2), stimulated inositol phosphate production with hP1R-WT. The results show
that short NH(2)-terminal peptides of PTH can be optimized for considerable gains
in signaling potency through modification of interactions involving the regions
of the receptor containing the transmembrane domains and extracellular loops.
PMID- 10777514
TI - Absence of cardiolipin in the crd1 null mutant results in decreased mitochondrial
membrane potential and reduced mitochondrial function.
AB - Cardiolipin (CL) is a unique phospholipid which is present throughout the
eukaryotic kingdom and is localized in mitochondrial membranes. Saccharomyces
cerevisiae cells containing a disruption of CRD1, the structural gene encoding CL
synthase, have no CL in mitochondrial membranes. To elucidate the physiological
role of CL, we compared mitochondrial functions in the crd1Delta mutant and
isogenic wild type. The crd1Delta mutant loses viability at elevated temperature,
and prolonged culture at 37 degrees C leads to loss of the mitochondrial genome.
Mutant membranes have increased phosphatidylglycerol (PG) when grown in a
nonfermentable carbon source but have almost no detectable PG in medium
containing glucose. In glucose-grown cells, maximum respiratory rate, ATPase and
cytochrome oxidase activities, and protein import are deficient in the mutant.
The ADP/ATP carrier is defective even during growth in a nonfermentable carbon
source. The mitochondrial membrane potential is decreased in mutant cells. The
decrease is more pronounced in glucose-grown cells, which lack PG, but is also
apparent in membranes containing PG (i.e. in nonfermentable carbon sources). We
propose that CL is required for maintaining the mitochondrial membrane potential
and that reduced membrane potential in the absence of CL leads to defects in
protein import and other mitochondrial functions.
PMID- 10777516
TI - HighWire press is 5 years old
PMID- 10777515
TI - Platelet-derived growth factor (PDGF) receptor-alpha activates c-Jun NH2-terminal
kinase-1 and antagonizes PDGF receptor-beta -induced phenotypic transformation.
AB - Platelet-derived growth factor (PDGF) is a potent mitogen for mesenchymal cells.
The PDGF B-chain (c-sis proto-oncogene) homodimer (PDGF BB) and v-sis, its viral
counterpart, activate both alpha- and beta-receptor subunits (alpha-PDGFR and
beta-PDGFR) and mediate anchorage-independent growth in NIH3T3 cells. In
contrast, the PDGF A chain homodimer (PDGF AA) activates alpha-PDGFR only and
fails to induce phenotypic transformation. In the present study, we investigated
alpha- and beta-PDGFR specific signaling pathways that are responsible for the
differences between the transforming ability of PDGF AA and BB. To study PDGF BB
activation of beta-PDGFR, we established NIH3T3 clones in which alpha-PDGFR
signaling is inhibited by a dominant-negative alpha-PDGFR, or an antisense
construct of alpha-PDGFR. Here, we demonstrate that beta-PDGFR activation alone
is sufficient for PDGF BB-mediated anchorage-independent cell growth. More
importantly, inhibition of alpha-PDGFR signaling enhanced PDGF BB-mediated
phenotypic transformation, suggesting that alpha-PDGFR antagonizes beta-PDGFR
induced transformation. While both alpha- and beta-receptors effectively activate
ERKs, alpha-PDGFR, but not beta-PDGFR, activates stress-activated protein kinase
1/c-Jun NH(2)-terminal kinase-1 (JNK-1). Inhibition of JNK-1 activity using a
dominant-negative JNK-1 mutant markedly enhanced PDGF BB-mediated anchorage
independent cell growth, demonstrating an antagonistic role for JNK-1 in PDGF
induced transformation. Consistently, overexpression of wild-type JNK-1 reduced
PDGF BB-mediated transformation. Taken together, the present study showed that
alpha- and beta-PDGFRs differentially regulate Ras-mitogen-activated protein
kinase pathways critical for regulation of cell transformation, and
transformation suppressing activity of alpha-PDGFR involves JNK-1 activation.
PMID- 10777517
TI - ICln is essential for cellular and early embryonic viability.
AB - pICln is a 26-kDa protein that is ubiquitously expressed and highly conserved
from Xenopus laevis to Homo sapiens. The physiological functions of pICln remain
to be established. To address this question, we disrupted the ICln gene in
embryonic stem cells. We found that murine embryos lacking ICln die early in
gestation (between stages E3.5 and E7.5). Furthermore, we found that ICln is
essential for embryonic stem cell viability. Previously, we showed that pICln
interacts directly with a homolog of a yeast protein that binds a PAK-like kinase
and participates in the regulation of cell morphology and cell cycling. pICln
also forms a complex with several core spliceosomal proteins, and this
interaction may play a role in the regulation of spliceosomal biogenesis.
Collectively, these data strongly suggest that pICln participates in critical
cellular pathways, including regulation of the cell cycle and RNA processing.
PMID- 10777518
TI - Electron paramagnetic resonance evidence for a novel interconversion of [3Fe
4S](+) and [4Fe-4S](+) clusters with endogenous iron and sulfide in anaerobic
ribonucleotide reductase activase in vitro.
AB - We report an EPR study of the iron-sulfur enzyme, anaerobic ribonucleotide
reductase activase from Lactococcus lactis. The activase (nrdG gene) together
with S-adenosyl-L-methionine (AdoMet) give rise to a glycyl radical in the NrdD
component. A semi-reduced [4Fe-4S](+) cluster with an axially symmetric EPR
signal was produced upon photochemical reduction of the activase. Air exposure of
the reduced enzyme gave a [3Fe-4S](+) cluster. The Fe(3)S(4) cluster was
convertible to the EPR-active [4Fe-4S](+) cluster by renewed treatment with
reducing agents, demonstrating a reversible [3Fe-4S](+)- to-[4Fe-4S](+) cluster
conversion without exogenous addition of iron or sulfide. Anaerobic reduction of
the activase by a moderate concentration of dithionite also resulted in a semi
reduced [4Fe-4S](+) cluster. Prolonged reduction gave an EPR-silent fully reduced
state, which was enzymatically inactive. Both reduced states gave the [3Fe-4S](+)
EPR signal after air exposure. The iron-sulfur cluster interconversion was also
studied in the presence of AdoMet. The EPR signal of semi-reduced activase-AdoMet
had rhombic symmetry and was independent of which reductant was applied, whereas
the EPR signal of the [3Fe-4S](+) cluster after air exposure was unchanged. The
results indicate that an AdoMet-mediated [4Fe-4S](+) center is the native active
species that induces the formation of a glycyl radical in the NrdD component.
PMID- 10777519
TI - TFIIA has activator-dependent and core promoter functions in vivo.
AB - The physiological role of TFIIA was investigated by analyzing transcription in a
yeast strain that contains a TATA-binding protein (TBP) mutant (N2-1) defective
for interacting with TFIIA. In cells containing N2-1, transcription from a set of
artificial his3 promoters dependent on different activators is generally reduced
by a similar extent, indicating that TFIIA function is largely nonselective for
activators. In addition, TATA element utilization, a core promoter function, is
altered at his3 promoters dependent on weak activators. Genomic expression
analysis reveals that 3% of the genes are preferentially affected by a factor of
4 or more. Chimeras of affected promoters indicate that the sensitivity to the
TFIIA-TBP interaction can map either to the upstream or core promoter region.
Unlike wild-type TBP or TFIIA, the N2-1 derivative does not activate
transcription when artificially recruited to the promoter via a heterologous DNA
binding domain, indicating that TFIIA is important for transcription even in the
absence of an activation domain. Taken together, these results suggest that TFIIA
plays an important role in both activator-dependent and core promoter functions
in vivo. Further, they suggest that TFIIA function may not be strictly related to
the recruitment of TBP to promoters but may also involve a step after TBP
recruitment.
PMID- 10777520
TI - Isolation and functional expression of human COQ3, a gene encoding a
methyltransferase required for ubiquinone biosynthesis.
AB - The COQ3 gene in Saccharomyces cerevisiae encodes an O-methyltransferase required
for two steps in the biosynthetic pathway of ubiquinone (coenzyme Q, or Q). This
enzyme methylates an early Q intermediate, 3,4-dihydroxy-5-polyprenylbenzoic
acid, as well as the final intermediate in the pathway, converting demethyl-Q to
Q. This enzyme is also capable of methylating the distinct prokaryotic early
intermediate 2-hydroxy-6-polyprenyl phenol. A full-length cDNA encoding the human
homologue of COQ3 was isolated from a human heart cDNA library by sequence
homology to rat Coq3. The clone contained a 933-base pair open reading frame that
encoded a polypeptide with a great deal of sequence identity to a variety of
eukaryotic and prokaryotic Coq3 homologues. In the region between amino acids 89
and 255 in the human sequence, the rat and human homologues are 87% identical,
whereas human and yeast are 35% identical. When expressed in multicopy, the human
construct rescued the growth of a yeast coq3 null mutant on a nonfermentable
carbon source and restored coenzyme Q biosynthesis, although at lower levels than
that of wild type yeast. In vitro methyltransferase assays using farnesylated
analogues of intermediates in the coenzyme Q biosynthetic pathway as substrates
showed that the human enzyme is active with all three substrates tested.
PMID- 10777521
TI - Heat-inactivated proteins managed by DnaKJ-GrpE-ClpB chaperones are released as a
chaperonin-recognizable non-native form.
AB - Chaperones of Thermus thermophilus cooperate in reactivation of heat-inactivated
proteins. The protein, inactivated at a high temperature in a TDnaKJ-GrpE set,
recovered its activity during subsequent incubation with TClpB at moderate
temperature (Motohashi, K., Watanabe, Y., Yohda, M., and Yoshida, M. (1999) Proc.
Natl. Acad. Sci. U. S. A. 96, 7184-7189). Here, we report that the addition of
chaperonin (Tcpn) at moderate temperature improves the yield of the TDnaKJ-GrpE
ClpB-dependent reactivation. The trap-Tcpn, which binds substrate protein but
does not release it, inhibits reactivation severely. Maximum recovery is gained
at sub-stoichiometric amounts of each component of TDnaKJ, TGrpE, and TClpB
relative to the substrate monomer. These observations indicate that, driven by
ATP hydrolysis, TDnaKJ-GrpE-ClpB chaperones catalytically cooperate and release
heat-inactivated protein as a non-native, chaperonin-recognizable folding
intermediate.
PMID- 10777522
TI - Transcription factor S, a cleavage induction factor of the archaeal RNA
polymerase.
AB - We have analyzed the function of an archaeal protein (now called transcription
factor S (TFS)) that shows sequence similarity to eukaryotic transcription factor
IIS (TFIIS) as well as to small subunits of eukaryotic RNA polymerases I (A12.6),
II (B12.2), and III (C11). Western blot analysis with antibodies against
recombinant TFS demonstrated that this protein is not a subunit of the RNA
polymerase. In vitro transcription experiments with paused elongation complexes
at position +25 showed that TFS is able to induce cleavage activity in the
archaeal RNA polymerase in a similar manner to TFIIS. In the presence of TFS, the
cleavage activity of the RNA polymerase truncates the RNA back to position +15 by
releasing mainly dinucleotides from the 3'-end of the nascent RNA. Furthermore,
TFS reduces the amount of non-chaseable elongation complexes at position +25 as
well as position +45. These findings clearly demonstrate that this protein has a
similar function to eukaryotic TFIIS.
PMID- 10777523
TI - Site-directed mutagenesis of 2,4-dichlorophenoxyacetic acid/alpha-ketoglutarate
dioxygenase. Identification of residues involved in metallocenter formation and
substrate binding.
AB - 2,4-dichlorophenoxyacetic acid (2,4-D)/alpha-ketoglutarate (alpha-KG) dioxygenase
(TfdA) is an Fe(II)-dependent enzyme that catalyzes the first step in degradation
of the herbicide 2,4-D. The active site structures of a small number of enzymes
within the alpha-KG-dependent dioxygenase superfamily have been characterized and
shown to have a similar HXDX(50-70)HX(10)RXS arrangement of residues that make up
the binding sites for Fe(II) and alpha-KG. TfdA does not have obvious homology to
the dioxygenases containing the above motif but is related in sequence to eight
other enzymes in the superfamily that form a distinct consensus sequence
(HX(D/E)X(138-207) HX(10)R/K). Variants of TfdA were created to examine the roles
of putative metal-binding residues and the functions of the other seven
histidines in this protein. The H167A, H200A, H213A, H245A, and H262A forms of
TfdA formed inclusion bodies when overproduced in Escherichia coli DH5alpha;
however, these proteins were soluble when fused to the maltose-binding protein
(MBP). MBP-TfdA exhibited kinetic parameters similar to the native enzyme. The
H8A and H235A variants were catalytically similar to wild-type TfdA. MBP-H213A
and H216A TfdA have elevated K(m) values for 2,4-D, and the former showed a
decreased k(cat), suggesting these residues may affect substrate binding or
catalysis. The H113A, D115A, MBP-H167A, MBP-H200A, MBP-H245A and MBP-H262A
variants of TfdA were inactive. Gel filtration analysis revealed that the latter
two proteins were highly aggregated. The remaining four inactive variants were
examined in their Cu(II)-substituted forms by EPR and electron spin-echo envelope
modulation (ESEEM) spectroscopic methods. Changes in EPR spectra upon addition of
substrates indicated that copper was present at the active site in the H113A and
D115A variants. ESEEM analysis revealed that two histidines are bound
equatorially to the copper in the D115A and MBP-H167A TfdA variants. The
experimental data and sequence analysis lead us to conclude that His-113, Asp
115, and His-262 are likely metal ligands in TfdA and that His-213 may aid in
catalysis or binding of 2,4-D.
PMID- 10777524
TI - Inactivation of active thrombin-activable fibrinolysis inhibitor takes place by a
process that involves conformational instability rather than proteolytic
cleavage.
AB - Thrombin-activable fibrinolysis inhibitor (TAFI) is present in the circulation as
an inactive zymogen. Thrombin converts TAFI to a carboxypeptidase B-like enzyme
(TAFIa) by cleaving at Arg(92) in a process accelerated by the cofactor,
thrombomodulin. TAFIa attenuates fibrinolysis. TAFIa can be inactivated by both
proteolysis by thrombin and spontaneous temperature-dependent loss of activity.
The identity of the thrombin cleavage site responsible for loss of TAFIa activity
was suggested to be Arg(330), but site-directed mutagenesis of this residue did
not prevent inactivation of TAFIa by thrombin. In this study we followed TAFI
activation and TAFIa inactivation by thrombin/thrombomodulin in time and
characterized the cleavage pattern of TAFI using matrix-assisted laser desorption
ionization mass spectrometry. Mass matching of the fragments revealed that TAFIa
was cleaved at Arg(302). Studies of a mutant R302Q-TAFI confirmed identification
of this thrombin cleavage site and, furthermore, suggested that inactivation of
TAFIa is based on its conformational instability rather than proteolytic cleavage
at Arg(302).
PMID- 10777525
TI - The requirement of both extracellular regulated kinase and p38 mitogen-activated
protein kinase for stimulation of cytosolic phospholipase A(2) activity by either
FcgammaRIIA or FcgammaRIIIB in human neutrophils. A possible role for Pyk2 but
not for the Grb2-Sos-Shc complex.
AB - The signal transduction pathways initiated by opsonized zymosan (OZ) leading to
activation of cytosolic phospholipase A(2) (cPLA(2)) in human neutrophils remain
obscure. In a previous study, we showed that the activation of cPLA(2) by OZ is
tyrosine kinase-dependent. The present study demonstrates that the signals
initiated by OZ involve activation of tyrosine kinase Pyk2 but not the formation
of the adhesion protein complex, Shc-Grb2-Sos. Stimulation of cPLA(2) activity by
OZ is mediated by Fc gamma receptors (FcgammaRs) and not by complement receptors
for the C3b protein. Cross-linking of FcgammaRIIA or FcgammaRIIIB induces p38
mitogen-activated protein (MAP) kinase and extracellular regulated kinase (ERK)
phosphorylation. The kinetics of cPLA(2) activity stimulated by either of the
FcgammaRs or by both is similar to that of p38 MAP kinase and was detected as
early as 15 s after stimulation, maintained a plateau for 10 min, and decreased
thereafter. ERK activation was detected also within 15 s but decreased
significantly 5 min after stimulation. The MEK inhibitor, PD-098059, or the p38
MAP kinase inhibitor, SB-203580, caused a partial inhibition during the time
course of cPLA(2) activity, whereas their combination caused a total inhibition.
Thus, although ERK activation is significantly shorter than that of p38 MAP
kinase, it is equally required for activation and maintenance of cPLA(2) activity
by occupancy of a single receptor, FcgammaRIIA or FcgammaRIIIB.
PMID- 10777526
TI - Assembly of gamma- with alpha-globin chains to form human fetal hemoglobin in
vitro and in vivo.
AB - Soluble gamma-globin chains were expressed in bacteria and purified to assess the
mechanism of gamma- and alpha-chain assembly to form Hb F. Formation of Hb F in
vitro following incubation of equimolar mixtures of gamma and alpha chains was
about 4 x 10(5)-fold slower than assembly of alpha and beta chains to form Hb A
in vitro. Results of assembly for gamma(116Ile-->His) and gamma(112Thr-->Asp)
chains with alpha chains were similar to that of beta chains, whereas assembly of
gamma(112Thr-->Cys) and alpha chains was similar to wild type gamma chains,
indicating that amino acid differences at alpha1beta1 and alpha1gamma1
interaction sites between gamma116 Ile and beta116 His are responsible for the
different assembly rates in vitro in the formation of Hb F and Hb A. Homoassembly
in vitro of individual gamma chains as assessed by size-exclusion chromatography
shows that gamma and gamma(112Thr-->Cys) chains form stable dimers like alphabeta
and alphagamma that do not dissociate readily into monomers like beta chains. In
contrast, gamma(116Ile-->His) chains form monomers and dimers upon dilution.
These results are consistent with the slower assembly rate in vitro of gamma and
gamma(112Thr-->Cys) with alpha chains, whereas the faster rate of assembly of
gamma(116Ile-->His) and gamma(112Thr-->Asp) chains with alpha chains, like beta
chains, may be caused by dissociation to monomers. These results suggest that
dissociation of gamma(2) dimers to monomers limits formation of Hb F in vitro.
However, yields of soluble Hb F expressed in bacteria were similar to Hb A, and
no unassembled alpha and gamma chains were detected. These results indicate that
gamma chains assemble in vivo with alpha chains prior to forming stable gamma(2)
dimers, possibly binding to alpha chains as partially folded nascent gamma-globin
chains prior to release from polyribosomes.
PMID- 10777527
TI - Steady-state kinetic characterization and crystallization of a polychlorinated
biphenyl-transforming dioxygenase.
AB - The oxygenase component of biphenyl dioxygenase (BPDO) from Comamonas
testosteroni B-356 dihydroxylates biphenyl and some polychlorinated biphenyls
(PCBs), thereby initiating their degradation. Overexpressed, anaerobically
purified BPDO had a specific activity of 4.9 units/mg, and its oxygenase
component appeared to contain a full complement of Fe(2)S(2) center and catalytic
iron. Oxygenase crystals in space group R3 were obtained under anaerobic
conditions using polyethylene glycol as the precipitant. X-ray diffraction was
measured to 1.6 A. Steady-state kinetics assays demonstrated that BPDO had an
apparent k(cat)/K(m) for biphenyl of (1.2 +/- 0.1) x 10(6) M(-1) s(-1) in air
saturated buffer. Moreover, BPDO transformed dichlorobiphenyls (diClBs) in the
following order of apparent specificities: 3,3'- > 2,2'- > 4, 4'-diClB.
Strikingly, the ability of BPDO to utilize O(2) depended strongly on the biphenyl
substrate: k(cat)/K(m(O(2))) = (3.6 +/- 0. 3), (0.06 +/- 0.02), and (0.4 +/-
0.07) x 10(5) M(-1) s(-1) in the presence of biphenyl and 2,2'- and 3,3'-diClBs,
respectively. Moreover, biphenyl/O(2) consumed was 0.97, 0.44, 0.63, and 0.48 in
the presence of biphenyl and 2,2'-, 3,3'-, and 4,4'-diClBs, respectively. Within
experimental error, the balance of consumed O(2) was detected as H(2)O(2). Thus,
PCB congeners such as 2, 2'-diClB exact a high energetic cost, produce a
cytotoxic compound (H(2)O(2)), and can inhibit degradation of other congeners.
Each of these effects would be predicted to inhibit the aerobic microbial
catabolism of PCBs.
PMID- 10777528
TI - Substitution of the heme binding module in hemoglobin alpha- and beta-subunits.
Implication for different regulation mechanisms of the heme proximal structure
between hemoglobin and myoglobin.
AB - In our previous work, we demonstrated that the replacement of the "heme binding
module," a segment from F1 to G5 site, in myoglobin with that of hemoglobin alpha
subunit converted the heme proximal structure of myoglobin into the alpha-subunit
type (Inaba, K., Ishimori, K. and Morishima, I. (1998) J. Mol. Biol. 283, 311
327). To further examine the structural regulation by the heme binding module in
hemoglobin, we synthesized the betaalpha(HBM)-subunit, in which the heme binding
module (HBM) of hemoglobin beta-subunit was replaced by that of hemoglobin alpha
subunit. Based on the gel chromatography, the betaalpha(HBM)-subunit was
preferentially associated with the alpha-subunit to form a heterotetramer,
alpha(2)[betaalpha(HBM)(2)], just as is native beta-subunit. Deoxy
alpha(2)[betaalpha(HBM)(2)] tetramer exhibited the hyperfine-shifted NMR
resonance from the proximal histidyl N(delta)H proton and the resonance Raman
band from the Fe-His vibrational mode at the same positions as native hemoglobin.
Also, NMR spectra of carbonmonoxy and cyanomet alpha(2)[betaalpha(HBM)(2)]
tetramer were quite similar to those of native hemoglobin. Consequently, the heme
environmental structure of the betaalpha(HBM)-subunit in tetrameric
alpha(2)[betaalpha(HBM)(2)] was similar to that of the beta-subunit in native
tetrameric Hb A, and the structural conversion by the module substitution was not
clear in the hemoglobin subunits. The contrastive structural effects of the
module substitution on myoglobin and hemoglobin subunits strongly suggest
different regulation mechanisms of the heme proximal structure between these two
globins. Whereas the heme proximal structure of monomeric myoglobin is simply
determined by the amino acid sequence of the heme binding module, that of
tetrameric hemoglobin appears to be closely coupled to the subunit interactions.
PMID- 10777529
TI - Multiple interactions between receptor protein-tyrosine phosphatase (RPTP) alpha
and membrane-distal protein-tyrosine phosphatase domains of various RPTPs.
AB - Receptor protein-tyrosine phosphatase (RPTP) alpha belongs to the large family of
receptor protein-tyrosine phosphatases containing two tandem phosphatase domains.
Most of the catalytic activity is retained in the first, membrane-proximal domain
(RPTPalpha-D1), and little is known about the function of the second, membrane
distal domain (RPTPalpha-D2). We investigated whether proteins bound to RPTPalpha
using the two-hybrid system and found that the second domain of RPTPsigma
interacted with the juxtamembrane domain of RPTPalpha. We confirmed this
interaction by co-immunoprecipitation experiments. Furthermore, RPTPalpha not
only interacted with RPTPsigma-D2 but also with RPTPalpha-D2, LAR-D2, RPTPdelta
D2, and RPTPmu-D2, members of various RPTP subfamilies, although with different
affinities. In the yeast two-hybrid system and in glutathione S-transferase pull
down assays, we show that the RPTP-D2s interacted directly with the wedge
structure of RPTPalpha-D1 that has been demonstrated to be involved in
inactivation of the RPTPalpha-D1/RPTPalpha-D1 homodimer. The interaction was
specific because the equivalent wedge structure in LAR was unable to interact
with RPTPalpha-D2 or LAR-D2. In vivo, we show that other interaction sites exist
as well, including the C terminus of RPTPalpha-D2. The observation that
RPTPalpha, but not LAR, bound to multiple RPTP-D2s with varying affinities
suggests a specific mechanism of cross-talk between RPTPs that may regulate their
biological function.
PMID- 10777530
TI - Identification of a nuclear respiratory factor-1 binding site within the core
promoter of the human polio virus receptor/CD155 gene.
AB - In this report we describe a cis-acting element within the core promoter of the
CD155 gene specifying the polio virus receptor that is bound by the nuclear
respiratory factor-1 (NRF-1) transcription factor. DNase I footprint analysis
identified a nuclear protein binding site from -282 to -264 nucleotides upstream
of the translation initiation codon of the CD155 gene, which we have called foot
print IV (FPIV). Linker scanning mutagenesis revealed that a tandem repeat motif,
GCGCAGGCGCAG, located within FPIV was essential for the basal activity of the
CD155 core promoter. The results of the electrophoretic mobility shift assay
experiments suggested that identical FPIV binding activities were present in a
variety of nuclear extracts and that the tandem repeat was essential for binding.
A one-hybrid screen was then carried out using FPIV as bait to clone the cDNA of
the FPIV binding factor. The sequences of the cDNAs that were cloned from the
screen were identical to NRF-1, a result that was confirmed by further
electrophoretic mobility shift assay experiments. Overexpression of full-length
NRF-1 and a dominant-negative form of NRF-1 modulated reporter gene expression
driven by the core promoter. Remarkably, CD155 is the first gene shown to be
regulated by NRF-1 that possesses an expression profile during embryogenesis
correlating with this factor's proposed role in the development of the vertebrate
optic system. We propose that NRF-1, which has been shown by others to be
expressed during embryogenesis in animal systems, may be involved in regulating
the expression of CD155 at specific stages of central nervous system development.
PMID- 10777531
TI - Anion-mediated iron release from transferrins. The kinetic and mechanistic model
for N-lobe of ovotransferrin.
AB - Iron release process of ovotransferrin N-lobe (N-oTf) to anion/chelators has been
resolved using kinetic and mechanistic approach. The iron release kinetics of N
oTf were measured at the endosomal pH of 5.6 with three different anions such as
nitrilotriacetate, pyrophosphate, and sulfate using stopped flow
spectrofluorimetric method, all yielding clear biphasic progress curves. The two
observed rate constants and the corresponding amplitudes obtained from the double
exponential curve fit to the biphasic curves varied depending on the type and
concentration of anions. Several possible models for the iron release kinetic
mechanism were examined on the basis of a newly introduced quantitative equation.
Results from the curve fitting analyses were consistent with a dual pathway
mechanism that includes the competitive iron release from two different protein
states, namely, X and Y, with the respective first order rate constants of K(1)
and K(2) (X, domain closed holo N-oTf; Y, anion induced different conformer of
holo N-oTf). The reversible interconversions of X to Y and Y to X are driven by
the second order rate constant k(3) and the first order rate constant K(4),
respectively. The obtained rate constants were greatly variable for the three
anions depending on the synergistic or nonsynergistic nature. In the light of the
anion-binding sites of N-oTf located crystallographically, the compatible
mechanistic model that includes competitive anion binding to the iron
coordination sites and to a specific anion site is suggested for the dual pathway
iron release mechanism.
PMID- 10777532
TI - Silencing mediator of retinoic acid and thyroid hormone receptors, as a novel
transcriptional corepressor molecule of activating protein-1, nuclear factor
kappaB, and serum response factor.
AB - Silencing mediator of retinoic acid and thyroid hormone receptors (SMRT) is known
to interact with Sin3 and recruit the histone deacetylases (HDACs) that lead to
hypoacetylation of histones and transrepression of target transcription factors.
Herein, we found that coexpression of SMRT significantly repressed
transactivations by activating protein-1 (AP-1), nuclear factor-kappaB
(NFkappaB), and serum response factor (SRF) in a dose-dependent manner, but not
in the presence of trichostatin A, a specific inhibitor of HDAC. Similarly,
coexpression of HDAC1 and mSin3A also showed repressive effects. Consistent with
these results, the C-terminal region of SMRT directly interacted with SRF, the AP
1 components c-Jun and c-Fos, and the NFkappaB components p50 and p65, as
demonstrated by the yeast and mammalian two hybrid tests as well as the
glutathione S-transferase pull down assays. Thus, we concluded that SMRT serves
to recruit Sin3/HDACs to SRF, NFkappaB, and AP-1 in vivo and modulate their
transactivation.
PMID- 10777533
TI - Des-Arg(10)-kallidin engagement of the B1 receptor stimulates type I collagen
synthesis via stabilization of connective tissue growth factor mRNA.
AB - Expression of the kinin B1 receptor is up-regulated in chronic inflammatory and
fibrotic disorders; however, little is known about its role in fibrogenesis. We
examined human embryonic lung fibroblasts that constitutively express the B1
receptor and report that engagement of the B1 receptor by des-Arg(10)-kallidin
stabilized connective tissue growth factor (CTGF) mRNA, stimulated an increase in
alpha1(I) collagen mRNA, and stimulated type I collagen production. These events
were not observed in B2 receptor-activated fibroblasts. In addition, B1 receptor
activation by des-Arg(10)-kallidin induced a rise in cytosolic Ca(2+) that is
consistent with B1 receptor pharmacology. Our results show that the des-Arg(10)
kallidin-stimulated increase in alpha1(I) collagen mRNA was time- and dose
dependent, with a peak response observed at 20 h with 100 nM des-Arg(10)
kallidin. The increase in CTGF mRNA was also time- and dose-dependent, with a
peak response observed at 4 h with 100 nM des-Arg(10)-kallidin. The increase in
CTGF mRNA was blocked by the B1 receptor antagonist des-Arg(10),Leu(9)-kallidin.
Inhibition of protein synthesis by cycloheximide did not block the des-Arg(10)
kallidin-induced increase in CTGF mRNA. These results suggest that engagement of
the kinin B1 receptor contributes to fibrogenesis through increased expression of
CTGF.
PMID- 10777534
TI - Characterization and regulation of the 5'-flanking region of the murine
endothelial protein C receptor gene.
AB - The protein C pathway plays a critical role in the negative regulation of blood
coagulation. The nucleotide sequence of the murine endothelial protein C receptor
(mEPCR) gene was determined for 8.8 kilobase pairs of the genomic structure and
3.4 kilobase pairs of the 5'-flanking region. RNase protection assay revealed six
major transcription start sites clustered at -100 to -109 upstream of the
translation initiation site. A series of 5'-promoter deletion fragments were
fused to a luciferase reporter gene and transiently transfected into bovine
aortic endothelium. Deletion of the sequence from -220 to -180 dramatically
reduced luciferase expression in bovine aortic endothelial cells. This region of
the murine endothelial protein C receptor gene contains one AP4 site and one SP1
site. Mutations in the core sequence of the AP4 and SP1 sites impaired both
nuclear protein binding and luciferase expression. These results suggest
important roles for AP4 and SP1 in the constitutive expression of mEPCR. A
thrombin response element (CCCACCCC) was found to mediate the induction of mEPCR
by thrombin in cell culture. Transgenic mice were developed expressing green
fluorescent protein driven by the -350 to -1 or -1080 to -1 promoter. Thrombin up
regulated mEPCR and the transgene in vivo.
PMID- 10777536
TI - Transcriptional regulation of the ATP citrate-lyase gene by sterol regulatory
element-binding proteins.
AB - In an attempt to identify unknown target genes for SREBP-1, total RNA from a
stable Chinese hamster ovary cell line (CHO-487) expressing a mature form of
human SREBP-1a (amino acids 1-487) with a LacSwitch Inducible Mammalian
Expression System was subjected to a polymerase chain reaction subtraction
method. One of the fragments was found to have 90 and 86% homology with rat and
human ATP citrate-lyase (ACL) cDNA, respectively. When Hep G2 cells are cultured
under either sterol-loaded or -depleted conditions, expression of the gene is
induced approximately 2-3-fold by sterol depletion. To investigate the direct
effect of SREBP-1a on transcription, luciferase assays using the promoter of the
human ACL gene were performed. These deletion studies indicated that a minimum
160-base pair segment contains the information required for the transcriptional
regulation brought about by enforced expression of SREBP-1a. Luciferase assays
using mutant reporter genes revealed that SREBP-dependent transcriptional
regulation is mediated by two nearby motifs, the SREBP-binding site (a TCAGGCTAG
sequence) and the NF-Y-binding site (a CCAAT box). It was confirmed by gel
mobility shift assays that recombinant SREBP-1a binds to the sequence. Data from
studies with transgenic mice and reporter assays show that the ACL gene promoter
is activated by SREBP-1a more strongly than SREBP-2 in contrast to the HMG CoA
synthase and LDL receptor gene promoters, which exhibit the same preference for
the two factors. Therefore, SREBPs transcriptionally regulates ACL enzyme
activity, which generates the cytosolic acetyl CoA required for both cholesterol
and fatty acid synthesis.
PMID- 10777537
TI - Cloning, expression, and characterization of the acyl-CoA-binding protein in
African trypanosomes.
AB - African trypanosomes are shielded from their hosts' defenses by a coat of variant
surface glycoprotein molecules, each of which is attached to the plasma membrane
by a glycosylphosphatidylinositol anchor. During the later stages of
glycosylphosphatidylinositol biosynthesis, myristic acid is incorporated into the
anchor from the donor myristoyl-CoA by a series of unique fatty acid remodeling
and exchange reactions. We have cloned and expressed a recombinant trypanosome
acyl-CoA-binding protein that has a preference for binding relatively short chain
acyl-CoAs and that has a high affinity for binding myristoyl-CoA (K(d) = 3.5 x
10(-10) M). This protein enhances fatty acid remodeling of
glycosylphosphatidylinositol precursors in the trypanosome cell-free system. We
speculate that the trypanosome acyl-CoA-binding protein plays an active role in
supplying myristoyl-CoA to the fatty acid remodeling machinery in the parasite.
PMID- 10777535
TI - Enterotoxigenic Escherichia coli secretes active heat-labile enterotoxin via
outer membrane vesicles.
AB - Escherichia coli and other Gram-negative bacteria produce outer membrane vesicles
during normal growth. Vesicles may contribute to bacterial pathogenicity by
serving as vehicles for toxins to encounter host cells. Enterotoxigenic E. coli
(ETEC) vesicles were isolated from culture supernatants and purified on velocity
gradients, thereby removing any soluble proteins and contaminants from the crude
preparation. Vesicle protein profiles were similar but not identical to outer
membranes and differed between strains. Most vesicle proteins were resistant to
dissociation, suggesting they were integral or internal. Thin layer
chromatography revealed that major outer membrane lipid components are present in
vesicles. Cytoplasmic membranes and cytosol were absent in vesicles; however,
alkaline phosphatase and AcrA, periplasmic residents, were localized to vesicles.
In addition, physiologically active heat-labile enterotoxin (LT) was associated
with ETEC vesicles. LT activity correlated directly with the gradient peak of
vesicles, suggesting specific association, but could be removed from vesicles
under dissociating conditions. Further analysis revealed that LT is enriched in
vesicles and is located both inside and on the exterior of vesicles. The distinct
protein composition of ETEC vesicles and their ability to carry toxin may
contribute to the pathogenicity of ETEC strains.
PMID- 10777538
TI - Characterization of a catalytically slow AP lyase activity in DNA polymerase
gamma and other family A DNA polymerases.
AB - Mitochondrial DNA polymerase gamma (pol gamma) is active in base excision repair
of AP (apurinic/apyrimidinic) sites in DNA. Usually AP site repair involves
cleavage on the 5' side of the deoxyribose phosphate by AP endonuclease. Previous
experiments suggested that DNA pol gamma acts to catalyze the removal of a 5'
deoxyribose phosphate (dRP) group in addition to playing the conventional role of
a DNA polymerase. We confirm that DNA pol gamma is an active dRP lyase and show
that other members of the family A of DNA polymerases including Escherichia coli
DNA pol I also possess this activity. The dRP lyase reaction proceeds by
formation of a covalent enzyme-DNA intermediate that is converted to an enzyme
dRP intermediate following elimination of the DNA. Both intermediates can be
cross-linked with NaBH(4). For both DNA pol gamma and the Klenow fragment of pol
I, the enzyme-dRP intermediate is extremely stable. This limits the overall
catalytic rate of the dRP lyase, so that family A DNA polymerases, unlike pol
beta, may only be able to act as dRP lyases in repair of AP sites when they occur
at low frequency in DNA.
PMID- 10777539
TI - Transcriptional activation by hepatocyte nuclear factor-1 requires synergism
between multiple coactivator proteins.
AB - Hepatocyte nuclear factor-1 (HNF-1) plays an important role in the regulation of
a large number of genes expressed in the liver, kidney, and pancreatic beta
cells. In exploring the molecular mechanism involved in HNF-1-dependent gene
activation in the in vivo chromatin context, we found that HNF-1 can physically
interact with the histone acetyltransferases (HATs) CREB-binding protein (CBP),
p300/CBP-associated factor (P/CAF), Src-1, and RAC3. The transcriptional
activation potential of HNF-1 on a genome integrated promoter was strictly
dependent on the synergistic action of CBP and P/CAF, which can independently
interact with the N-terminal and C-terminal domain of HNF-1, respectively.
Moreover, the HAT activity of both coactivators was important, as opposed to the
selective requirement for the HAT activity of P/CAF in activation from a
transiently transfected reporter. Interaction of CBP with the N-terminal domain
of HNF-1 greatly increased the binding affinity for P/CAF with the C-terminal
activation domain, which may represent the molecular basis for the observed
functional synergism. The results support a model that involves the combined
action of multiple coactivators recruited by HNF-1, which activate transcription
by coupling nucleosome modification and recruitment of the general transcription
machinery.
PMID- 10777540
TI - Insight into the uncoupling mechanism of sarcoplasmic reticulum ATPase using the
phosphorylating substrate UTP.
AB - Ca(2+) transport and UTP hydrolysis catalyzed by sarcoplasmic reticulum Ca(2+)
ATPase from skeletal muscle was studied. A passive Ca(2+) load inside microsomal
vesicles clearly decreased the net uptake rate and the final accumulation of
Ca(2+) but not the UTP hydrolysis rate, causing energy uncoupling. In the absence
of passive leak, the Ca(2+)/P(i) coupling ratio was 0.7-0.8. UTP hydrolysis did
not maintain a rapid component of Ca(2+) exchange between the cytoplasmic and
lumenal compartments as occurs with ATP. The uncoupling process in the presence
of UTP is associated with: (i) the absence of a steady state accumulation of ADP
insensitive phosphoenzyme; (ii) the cytoplasmic dissociation of Ca(2+) bound to
the ADP-sensitive phosphoenzyme; and (iii) the absence of enzyme inhibition by
cyclopiazonic acid. All these characteristics confirm the lack of enzyme
conformations with low Ca(2+) affinity and point to the existence of an
uncoupling mechanism mediated by a phosphorylated form of the enzyme. Suboptimal
coupling values can be explained in molecular terms by the proposed functional
model.
PMID- 10777541
TI - The murine and human cholesterol 7alpha-hydroxylase gene promoters are
differentially responsive to regulation by fatty acids mediated via peroxisome
proliferator-activated receptor alpha.
AB - We determined if fatty acids can regulate the murine Cyp7a1 and human CYP7A1 gene
promoters via peroxisome proliferator-activated receptor alpha (PPARalpha)/9-cis
retinoic acid receptor alpha (RXRalpha). In transfected cells, the murine Cyp7a1
gene promoter displayed markedly lower basal activity, but greater sensitivity to
fatty acid- or WY 14,643-activated PPARalpha/RXRalpha when compared with the
human CYP7A1 gene promoter. PPARalpha/RXRalpha can bind to a site (Site II)
located within the region at nucleotides -158 to -132 of both promoters.
Mutagenesis of the human CYP7A1 Site II element abolished the response to
activated PPARalpha/RXRalpha. The murine Cyp7a1 gene promoter contains an
additional PPARalpha/RXRalpha-binding site (Site I) located within nucleotides
72 to -57. Replacement of a single residue in human CYP7A1 Site I with that found
in the murine Cyp7a1 Site I sequence enabled PPARalpha/RXRalpha binding, and this
mutation resulted in reduced basal activity, but substantially improved the
response to activated PPARalpha/RXRalpha in transfected cells. We conclude that
fatty acids can regulate the cyp7a gene promoter via PPARalpha/RXRalpha. The
differential response of the murine Cyp7a1 and human CYP7A1 gene promoters to
PPARalpha activators is attributable to the additional PPARalpha/RXRalpha-binding
site in the murine Cyp7a1 gene promoter.
PMID- 10777542
TI - Novel inhibition of gbetagamma-activated potassium currents induced by M(2)
muscarinic receptors via a pertussis toxin-insensitive pathway.
AB - G(i) protein-coupled receptors such as the M(2) muscarinic acetylcholine receptor
(mAChR) and A(1) adenosine receptor have been shown to activate G protein
activated inwardly rectifying K(+) channels (GIRKs) via pertussis toxin-sensitive
G proteins in atrial myocytes and in many neuronal cells. Here we show that
muscarinic M(2) receptors not only activate but also reversibly inhibit these
K(+) currents when stimulated with agonist for up to 2 min. The M(2) mAChR
mediated inhibition of the channel was also observed when the channels were first
activated by inclusion of guanosine 5'-O-(thiotriphosphate) in the pipette. Under
these conditions the M(2) mAChR-induced inhibition was quasi-irreversible,
suggesting a role for G proteins in the inhibitory process. In contrast, when
GIRK currents were maximally activated by co-expressing exogenous Gbetagamma, the
extent of acetylcholine (ACh)-induced inhibition was significantly reduced,
suggesting competition between the receptor-mediated inhibition and the large
pool of available Gbetagamma subunits. The signaling pathway that led to the ACh
induced inhibition of GIRK channels was unaffected by pertussis toxin
pretreatment. Furthermore, the internalization and agonist-induced
phosphorylation of M(2) mAChR was not required because a phosphorylation- and
internalization-deficient mutant of the M(2) mAChR was as potent as the wild-type
counterpart. Pharmacological agents modulating various protein kinases or
phosphatidylinositol 3-kinase did not affect the inhibition of GIRK currents.
Furthermore, the signaling pathway that mediates GIRK current inhibition was
found to be membrane-delimited because bath application of ACh did not inhibit
GIRK channel activity in cell-attached patches. Other G protein-coupled receptors
including M(4) mAChR and alpha(1A) adrenergic receptors also caused the
inhibition, whereas other G protein-coupled receptors including A(1) and A(3)
adenosine receptors and alpha(2A) and alpha(2C) adrenergic receptors could not
induce the inhibition. The presented results suggest the existence of a novel
signaling pathway that can be activated selectively by M(2) and M(4) mAChR but
not by adenosine receptors and that involves non-pertussis toxin-sensitive G
proteins leading to an inhibition of Gbetagamma-activated GIRK currents in a
membrane-delimited fashion.
PMID- 10777543
TI - Formation of W(3)A(1) electron-transferring flavoprotein (ETF) hydroquinone in
the trimethylamine dehydrogenase x ETF protein complex.
AB - The electron-transferring flavoprotein (ETF) from Methylophilus methylotrophus
(sp. W(3)A(1)) exhibits unusual oxidation-reduction properties and can only be
reduced to the level of the semiquinone under most circumstances (including
turnover with its physiological reductant, trimethylamine dehydrogenase (TMADH),
or reaction with strong reducing reagents such as sodium dithionite). In the
present study, we demonstrate that ETF can be reduced fully to its hydroquinone
form both enzymatically and chemically when it is in complex with TMADH.
Quantitative titration of the TMADH x ETF protein complex with sodium dithionite
shows that a total of five electrons are taken up by the system, indicating that
full reduction of ETF occurs within the complex. The results indicate that the
oxidation-reduction properties of ETF are perturbed upon binding to TMADH, a
conclusion further supported by the observation of a spectral change upon
formation of the TMADH x ETF complex that is due to a change in the environment
of the FAD of ETF. The results are discussed in the context of ETF undergoing a
conformational change during formation of the TMADH x ETF electron transfer
complex, which modulates the spectral and oxidation-reduction properties of ETF
such that full reduction of the protein can take place.
PMID- 10777544
TI - Coupling of the inositol 1,4,5-trisphosphate receptor and chromogranins A and B
in secretory granules.
AB - The secretory granules of neuroendocrine cells which contain large amounts of
Ca(2+) and chromogranins have been demonstrated to release Ca(2+) in response to
inositol 1,4,5-trisphosphate (IP(3)). Moreover, chromogranin A (CGA) has been
shown to interact with several secretory granule membrane proteins, including the
IP(3) receptor (IP(3)R). To determine whether the IP(3)Rs interact directly with
chromogranins A and B (CGB), two major proteins of the secretory granules, we
have used purified IP(3)R from bovine cerebellum in the interaction study with
CGA and CGB, and have shown that chromogranins A and B directly interact with the
IP(3)R at the intravesicular pH 5.5. Immunogold cytochemical study using the
IP(3)R and CGA antibodies indicated that IP(3)R-labeled gold particles were
localized in the periphery of the secretory granules, indicating the presence of
the IP(3)Rs on the secretory granule membrane. To determine whether the IP(3)R
and chromogranins A and B are physically linked in the cells, bovine type 1
IP(3)R (IP(3)R-1) and CGA or CGB are co-transfected into COS-7 cells and co
immunoprecipitation was carried out. Immunoprecipitation of the cell extracts
demonstrated the presence of CGA-IP(3)R-1 and CGB-IP(3)R-1 complexes,
respectively, indicating the complex formation between the IP(3)R and
chromogranins A and B in native state.
PMID- 10777545
TI - Stability of the ATF2 transcription factor is regulated by phosphorylation and
dephosphorylation.
AB - Trans-activation of the activating transcription factor-2 (ATF2) in response to
cellular stress requires the N-terminal phosphorylation of ATF2 by stress
activated protein kinases (SAPK). In this study, we investigated the role of ATF2
phosphorylation in the maintenance of ATF2 stability. Activation of SAPK by
forced expression of DeltaMEKK1 increased overall ATF2 ubiquitination, presumably
because of the enhanced dimerization of ATF2. Treatment of DeltaMEKK1-expressing
cells with okadaic acid led to the increase in N-terminal phosphorylation,
protection from ubiquitination, and accumulation of exogenously expressed ATF2,
indicating the role of protein phosphatases in balancing the effects of stress
kinases. Analysis of ubiquitination and degradation of the constitutively
dimerized ATF2 mutant (ATF2(Delta150-248)) showed that activation of JNK or p38
kinase renders ATF2 resistant to ubiquitination and degradation. This effect is
mediated by JNK/p38-dependent phosphorylation of ATF2 at Thr-69 and Thr-71,
because the phosphorylation-deficient mutant (ATF2(Delta150-248-T69A,T71A)) was
not protected from ubiquitination and degradation by the activation of SAPK.
Treatment of cells with okadaic acid elevated the tumor necrosis factor alpha
induced ATF2 level and the extent of its specific N-terminal phosphorylation.
Cycloheximide, which activates SAPK, while inhibiting protein synthesis,
stabilized endogenous ATF2. However, treatment of cells with the high dose of
SB203580, which inhibits JNK and p38 kinase, resulted in efficient degradation of
ATF2 in cells exposed to cycloheximide. This degradation was abrogated by co
treatment with the proteasome inhibitor MG132. Our findings suggest that N
terminal phosphorylation of ATF2 dimers protect ATF2 from ubiquitination and
degradation. We propose the hypothesis that the balance between SAPK and protein
phosphatases affects the duration and magnitude of ATF2 transcriptional output
because of the effect on substrate recognition for ubiquitination and
degradation.
PMID- 10777546
TI - Insulin receptor substrate-1 expression is regulated by estrogen in the MCF-7
human breast cancer cell line.
AB - Estrogens can stimulate the proliferation of estrogen-responsive breast cancer
cells by increasing their proliferative response to insulin-like growth factors.
The mechanism underlying the increased proliferation could involve the induction
of components of the insulin-like growth factor signal transduction pathway by
estrogen. In this study we have examined the regulation of the expression of
insulin receptor substrate-1, a major intracellular substrate of the type I
insulin-like growth factor receptor tyrosine kinase. Estradiol increased insulin
receptor substrate-1 mRNA and protein levels at concentrations consistent with a
mechanism involving the estrogen receptor. Insulin receptor substrate-1 was not
induced significantly by the antiestrogens tamoxifen and ICI 182,780, but they
inhibited the induction of insulin receptor substrate-1 by estradiol. Analysis of
tyrosine-phosphorylated insulin receptor substrate-1 showed that the highest
levels were found in cells stimulated by estradiol and insulin-like growth factor
I, whereas low levels were found in the absence of estradiol irrespective of
whether type I insulin-like growth factor ligands were present. Insulin receptor
substrate-2, -3, and -4 were not induced by estradiol. These results suggest that
estrogens and antiestrogens may regulate cell proliferation by controlling
insulin receptor substrate-1 expression, thereby amplifying or attenuating
signaling through the insulin-like growth factor signal transduction pathway.
PMID- 10777547
TI - Simultaneous suppression of cdc2 and cdk2 activities induces neuronal
differentiation of PC12 cells.
AB - The involvement of cdc2 and cdk2 during neuronal differentiation in rat
pheochromocytoma PC12 cells was examined. When PC12 cells were cultured with
nerve growth factor (NGF), expression of cdc2 decreased significantly after day
5, while expression of cdk2 decreased gradually after day 7. Cells overexpressing
cdc2 or cdk2 were resistant to NGF-induced differentiation and growth
suppression, and maintained high cdc2 or cdk2 kinase activity, respectively,
during NGF treatment. In contrast, the NGF-treated parental cells showed a marked
decline in these kinase activities after day 3. When PC12 cells were treated with
specific inhibitors of cdc2/cdk2 (butyrolactone-I, olomoucin), they showed marked
neurite extension and up-regulation of microtubule-associated protein 2
expression. In addition, treatment with mixtures of antisense oligonucleotides
for cdc2 and cdk2 resulted in down-regulation of both cdc2 and cdk2 kinase
activities as well as significant neurite outgrowth and up-regulation of
microtubule-associated protein 2 expression. However, neurite outgrowth was not
observed in cells treated with either single antisense oligonucleotide, or
antisense cdc2 + cdk4 or cdk2 + cdk4 oligonucleotide mixtures. These results
suggest that simultaneous down-regulation of cdc2 and cdk2 activity is sufficient
and necessary for neuronal differentiation in PC12 cells.
PMID- 10777548
TI - Steady-state and transient kinetics of Escherichia coli nitric-oxide dioxygenase
(flavohemoglobin). The B10 tyrosine hydroxyl is essential for dioxygen binding
and catalysis.
AB - Escherichia coli expresses an inducible flavohemoglobin possessing robust NO
dioxygenase activity. At 37 degrees C, the enzyme shows a maximal turnover number
(V(max)) of 670 s(-1) and K(m) values for NADH, NO, and O(2) equal to 4.8, 0.28,
and approximately 100 microM, respectively. Individual reduction, ligand binding,
and NO dioxygenation reactions were examined at 20 degrees C, where V(max) is
approximately 94 s(-1). Reduction by NADH occurs in two steps. NADH reduces bound
FAD with a rate constant of approximately 15 microM(-1) s(-1), and heme iron is
reduced by FADH(2) with a rate constant of 150 s(-1). Dioxygen binds tightly to
reduced flavohemoglobin, with association and dissociation rate constants equal
to 38 microM(-1) s(-1) and 0.44 s(-1), respectively, and the oxygenated
flavohemoglobin dioxygenates NO to form nitrate. NO also binds reversibly to
reduced flavohemoglobin in competition with O(2), dissociates slowly, and
inhibits NO dioxygenase activity at [NO]/[O(2)] ratios of 1:100. Replacement of
the heme pocket B10 tyrosine with phenylalanine increases the O(2) dissociation
rate constant approximately 80-fold and reduces NO dioxygenase activity
approximately 30-fold, demonstrating the importance of the tyrosine hydroxyl for
O(2) affinity and NO scavenging activity. At 37 degrees C, V(max)/K(m)(NO) is
2,400 microM(-1) s(-1), demonstrating that the enzyme is extremely efficient at
converting toxic NO into nitrate under physiological conditions.
PMID- 10777549
TI - Identification and characterization of HAOX1, HAOX2, and HAOX3, three human
peroxisomal 2-hydroxy acid oxidases.
AB - Computer-based approaches identified three distinct human 2-hydroxy acid oxidase
genes, HAOX1, HAOX2, and HAOX3, that encode proteins with significant sequence
similarity to plant glycolate oxidase, a prototypical 2-hydroxy acid oxidase. The
products of these genes are targeted to peroxisomes and have 2-hydroxy acid
oxidase activities. Each gene displays a distinct tissue-specific pattern of
expression, and each enzyme exhibits distinct substrate preferences. HAOX1 is
expressed primarily in liver and pancreas and is most active on the two-carbon
substrate, glycolate, but is also active on 2-hydroxy fatty acids. HAOX2 is
expressed predominantly in liver and kidney and displays highest activity toward
2-hydroxypalmitate. HAOX3 expression was detected only in pancreas, and this
enzyme displayed a preference for the medium chain substrate 2-hydroxyoctanoate.
These results indicate that all three human 2-hydroxy acid oxidases are involved
in the oxidation of 2-hydroxy fatty acids and may also contribute to the general
pathway of fatty acid alpha-oxidation. Primary hyperoxaluria type 1 (PH1) is
caused by defects in peroxisomal alanine-glyoxylate aminotransferase, the enzyme
that normally eliminates intraperoxisomal glyoxylate. The presence of HAOX1 in
liver and kidney peroxisomes and the ability of HAOX1 to oxidize glyoxylate to
oxalate implicate HAOX1 as a mediator of PH1 pathophysiology.
PMID- 10777550
TI - A T4-phage deoxycytidylate deaminase mutant that no longer requires deoxycytidine
5'-triphosphate for activation.
AB - A deoxycytidylate (dCMP) deaminase encoded in T4-bacteriophage DNA that is
induced on phage infection of Escherichia coli was shown earlier (Maley, G. F.,
Duceman, B. W., Wang, A. M., Martinez, J. M., and Maley, F. (1990) J. Biol. Chem.
265, 47-51) to be similar in size, properties, and amino acid composition to the
T2-phage-induced deaminase. Neither enzyme is active in the absence of dCTP or
its natural activator, 5-hydroxymethyl-dCTP. However, on changing the arginine
(Arg) at residue 115 of the T4-deaminase to either a glutamate (R115E) or a
glutamine (R115Q), the resulting mutant enzymes were active in the absence of
dCTP, with each mutant possessing a turnover number or k(cat) that is about 15%
that of the wild-type deaminase. When compared on the basis of specific activity,
however, the mutants are about 40-50% of the wild-type (WT)-enzyme's specific
activity. Molecular weight analysis on the wild-type and mutant deaminases using
HPLC size exclusion chromatography revealed that the wild-type deaminase was
basically a hexamer, particularly in the presence of dCTP, regardless of the
extent of dilution. Under similar conditions, R115E remained a dimer, whereas
R115Q and F112A varied from hexamers to dimers particularly at concentrations
normally present in the assay solution. Activity measurements appear to support
the conclusion that the hexameric form of the enzyme is activated by dCTP, while
the dimer is not. Another feature emphasizing the difference between the WT and
mutant deaminases was observed on their denaturation-renaturation in EDTA, which
revealed the mutants to be restored to 50% of their original activities with the
WT deaminase only marginally restored.
PMID- 10777551
TI - Overproduction of Pex5p stimulates import of alcohol oxidase and dihydroxyacetone
synthase in a Hansenula polymorpha Pex14 null mutant.
AB - Hansenula polymorpha Deltapex14 cells are affected in peroxisomal matrix protein
import and lack normal peroxisomes. Instead, they contain peroxisomal membrane
remnants, which harbor a very small amount of the major peroxisomal matrix
enzymes alcohol oxidase (AO) and dihydroxyacetone synthase (DHAS). The bulk of
these proteins is, however, mislocated in the cytosol. Here, we show that in
Deltapex14 cells overproduction of the PTS1 receptor, Pex5p, leads to enhanced
import of the PTS1 proteins AO and DHAS but not of the PTS2 protein amine
oxidase. The import of the PTS1 protein catalase (CAT) was not stimulated by
Pex5p overproduction. The difference in import behavior of AO and CAT was not
related to their PTS1, since green fluorescent protein fused to the PTS1 of
either AO or CAT were both not imported in Deltapex14 cells overproducing Pex5p.
When produced in a wild type control strain, both proteins were normally imported
into peroxisomes. In Deltapex14 cells overproducing Pex5p, Pex5p had a dual
location and was localized in the cytosol and bound to the outer surface of the
peroxisomal membrane. Our results indicate that binding of Pex5p to the
peroxisomal membrane and import of certain PTS1 proteins can proceed in the
absence of Pex14p.
PMID- 10777552
TI - Induction of the fatty acid transport protein 1 and acyl-CoA synthase genes by
dimer-selective rexinoids suggests that the peroxisome proliferator-activated
receptor-retinoid X receptor heterodimer is their molecular target.
AB - The intracellular fatty acid content of insulin-sensitive target tissues
determines in part their insulin sensitivity. Uptake of fatty acids into cells is
a controlled process determined in part by a regulated import/export system that
is controlled at least by two key groups of proteins, i.e. the fatty acid
transport protein (FATP) and acyl-CoA synthetase (ACS), which facilitate,
respectively, the transport of fatty acids across the cell membrane and catalyze
their esterification to prevent their efflux. Previously it was shown that the
expression of the FATP-1 and ACS genes was controlled by insulin and by
peroxisome proliferator-activated receptor (PPAR) agonists in liver or in adipose
tissue. The aim of this investigation was to determine the effects of retinoic
acid derivatives on the expression of FATP-1 and ACS. In several cultured cell
lines, it was shown that the expression of both the FATP-1 and ACS mRNAs was
specifically induced at the transcriptional level by selective retinoid X
receptor (RXR) but not by retinoic acid receptor (RAR) ligands. This effect was
most pronounced in hepatoma cell lines. A similar induction of FATP-1 and ACS
mRNA levels was also observed in vivo in Zucker diabetic fatty rats treated with
the RXR agonist, LGD1069 (4-[1-(3,5,5,8,8-pentamethyl-5,6,7, 8-tetrahydro-2
naphthyl)ethenyl]benzoic acid). Through the use of heterodimer-selective
compounds, it was demonstrated that the modulatory effect of these rexinoids on
FATP-1 and ACS gene expression was mediated through activation of RXR in the
context of the PPAR-RXR heterodimer. The observation that both RXR and PPAR
agonists can stimulate the transcription of genes implicated in lipid metabolism,
suggest that rexinoids may also act as lipid-modifying agents and support a role
of the permissive PPAR-RXR heterodimer in the control of insulin sensitivity.
PMID- 10777553
TI - Carbachol-stimulated transactivation of epidermal growth factor receptor and
mitogen-activated protein kinase in T(84) cells is mediated by intracellular
Ca2+, PYK-2, and p60(src).
AB - Ca(2+)-dependent agonists, such as carbachol (CCh), stimulate epidermal growth
factor receptor (EGFR) transactivation and mitogen-activated protein kinase
activation in T(84) intestinal epithelial cells. This pathway constitutes an
antisecretory mechanism by which CCh-stimulated chloride secretion is limited.
Here, we investigated mechanisms underlying CCh-stimulated epidermal growth
factor receptor (EGFR) transactivation. Thapsigargin (TG, 2 microM) stimulated
EGFR and extracellular signal-regulated kinase (ERK) phosphorylation in T(84)
cells. Inhibition of either EGFR or ERK activation, with tyrphostin AG1478 (1
microM) and PD 98059 (20 microM), respectively, potentiated chloride secretory
responses to TG, as measured by changes in short-circuit current (I(sc)) across
T(84) cells. CCh (100 microM) stimulated tyrosine phosphorylation and association
of the Ca(2+)-dependent tyrosine kinase, PYK-2, with the EGFR, which was
inhibited by the Ca(2+) chelator, BAPTA (20 microM). The calmodulin inhibitor,
fluphenazine (50 microM) inhibited CCh-stimulated PYK-2 association with the EGFR
and phosphorylation of EGFR and ERK. CCh also induced tyrosine phosphorylation of
p60(src) and association of p60(src) with both PYK-2 and the EGFR. The Src family
kinase inhibitor, PP2 (20 nM-20 microM) attenuated CCh-stimulated EGFR and ERK
phosphorylation and potentiated chloride secretory responses to CCh. We conclude
that CCh-stimulated transactivation of the EGFR is mediated by a pathway
involving elevations in intracellular Ca(2+), calmodulin, PYK-2, and p60(src).
This pathway represents a mechanism that limits CCh-stimulated chloride secretion
across intestinal epithelia.
PMID- 10777554
TI - CCAAT/enhancer-binding protein-beta regulates interferon-induced transcription
through a novel element.
AB - We have described previously a novel interferon (IFN)-responsive cis-acting
enhancer element called gamma-IFN-activated transcriptional element (GATE). GATE
is distinct from the known IFN-stimulated elements and binds to novel transacting
factors. To identify the gamma-IFN-responsive transacting factors that interact
with GATE, we have screened a cDNA expression library derived from IFN-gamma
stimulated murine macrophage cell line and isolated three different cDNAs. Among
these is a gene coding for the pleiotropic transcription factor, CCAAT/enhancer
binding protein-beta (C/EBP-beta). We report here that the gene for C/EBP-beta
binds to GATE and induces gene expression. A mutant C/EBP-beta interferes with
the IFN-gamma-stimulated transcription of the ISGF3gamma (p48) promoter. Other
members of the C/EBP family do not cause these effects. Interestingly, the
expression of C/EBP-beta, not the other members of its family, is induced by IFN
gamma. These studies thus identify a novel role for C/EBP-beta in the IFN
signaling pathways.
PMID- 10777555
TI - Oxidized low density lipoprotein (ox-LDL) binding to ox-LDL receptor-1 in
endothelial cells induces the activation of NF-kappaB through an increased
production of intracellular reactive oxygen species.
AB - In this study we examined the effect of oxidized low density lipoprotein (ox-LDL)
on the intracellular production of reactive oxygen species (ROS) in bovine aortic
endothelial cells (BAECs) and whether this increase occurs through its binding to
the endothelial receptor lectin-like ox-LDL receptor-1 (LOX-1). Furthermore, this
study also aimed to ascertain whether the binding of ox-LDL to LOX-1 is
associated with NF-kappaB activation. ox-LDL induced a significant dose-dependent
increase in ROS production after a 30-s incubation with BAECs (p < 0.01). ROS
formation was markedly reduced in BAECs incubated with anti-LOX-1 monoclonal
antibody (p < 0.001), while control nonimmune IgG produced no effect. ox-LDL
induced a time- and dose-dependent significant increase in ROS formation only in
CHO-K1 cells stably expressing bovine LOX-1 (p < 0.001), while no increase was
present in CHO-K1 cells. The activation of the transcription factor NF-kappaB in
BAECs was evident after a 5-min incubation with ox-LDL and was attenuated by anti
LOX-1 monoclonal antibody. The conclusion is that one of the pathophysiological
consequences of ox-LDL binding to LOX-1 may be the activation of NF-kappaB
through an increased ROS production.
PMID- 10777556
TI - Purification, cloning, expression, and mechanism of action of a novel platelet
aggregation inhibitor from the salivary gland of the blood-sucking bug, Rhodnius
prolixus.
AB - Rhodnius prolixus aggregation inhibitor 1 (RPAI-1), a 19-kDa protein isolated
from the salivary gland of R. prolixus, was purified by strong cation exchange
and reverse-phase high performance liquid chromatographies. Based on 49 amino
terminal amino acid sequences of RPAI-1, primers were produced to generate probes
to screen an R. prolixus salivary gland cDNA library. A phage containing the full
length clone of RPAI-1 codes for a mature protein of 155 amino acids. RPAI-1
shows sequence homology to triabin and pallidipin, lipocalins from Triatoma
pallidipennis. The cDNA sequence was cloned in Pet17B Escherichia coli expression
vector, producing an active peptide. RPAI-1 inhibits human platelet-rich plasma
aggregation triggered by low concentrations of ADP, collagen, arachidonic acid,
thromboxane A(2) mimetics (U46619), and very low doses of thrombin and convulxin.
Here we show that ADP is the target of RPAI-1 since (i) RPAI-1 inhibits ADP
dependent large aggregation formation and secretion triggered by U46619, without
affecting Ca(2+) increase and shape change; (ii) ADP restored the inhibition of
U46619-induced platelet aggregation by RPAI-1, (iii) PGE(1)-induced increase of
cAMP (which is antagonized by U46619 in an ADP-dependent manner) was restored by
RPAI-1, (iv) RPAI-1 inhibits low concentrations of ADP-mediated responses of
indomethacin-treated platelets, and (v) RPAI-1 binds to ADP, as assessed by large
zone chromatography. RPAI-1 affects neither integrin alpha(2)beta(1)- nor
glycoprotein VI-mediated platelet responses. We conclude that RPAI-1 is the first
lipocalin described that inhibits platelet aggregation by a novel mechanism,
binding to ADP.
PMID- 10777557
TI - Mapping the agonist binding site of the nicotinic acetylcholine receptor.
Orientation requirements for activation by covalent agonist.
AB - To characterize the structural requirements for ligand orientation compatible
with activation of the Torpedo nicotinic acetylcholine receptor (nAChR), we used
Cys mutagenesis in conjunction with sulfhydryl-reactive reagents to tether
primary or quaternary amines at defined positions within the agonist binding site
of nAChRs containing mutant alpha- or gamma-subunits expressed in Xenopus
oocytes. 4-(N-Maleimido)benzyltrimethylammonium and 2
aminoethylmethanethiosulfonate acted as irreversible antagonists when tethered at
alphaY93C, alphaY198C, or gammaE57C, as well as at alphaN94C (2
aminoethylmethanethiosulfonate only). [2-(Trimethylammonium)-ethyl]
methanethiosulfonate (MTSET), which attaches thiocholine to binding site Cys,
also acted as an irreversible antagonist when tethered at alphaY93C, alphaN94C,
or gammaE57C. However, MTSET modification of alphaY198C resulted in prolonged
activation of the nAChR not reversible by washing but inhibitable by subsequent
exposure to non-competitive antagonists. Modification of alphaY198C (or any of
the other positions tested) by [(trimethylammonium)methyl]methanethiosulfonate
resulted only in irreversible inhibition, while modification of alphaY198C by [3
(trimethylammonium)propyl]methanethiosulfonate resulted in irreversible
activation of nAChR, but at lower efficacy than by MTSET. Thus changing the
length of the tethering arm by less than 1 A in either direction markedly effects
the ability of the covalent trimethylammonium to activate the nAChR, and agonist
activation depends on a very selective orientation of the quaternary ammonium
within the agonist binding site.
PMID- 10777558
TI - Distinct mechanisms of STAT phosphorylation via the interferon-alpha/beta
receptor. Selective inhibition of STAT3 and STAT5 by piceatannol.
AB - Interferon-alpha (IFNalpha) can activate several members of the signal
transducers and activator of transcription (STAT) transcription factor family, a
process that requires the tyrosine kinases Jak1 and Tyk2. Here we provide
evidence that IFNalpha-mediated activation of various STAT proteins is regulated
by distinct mechanisms. Piceatannol, previously reported as a Syk/ZAP70-specific
kinase inhibitor, selectively inhibits the tyrosine phosphorylation of STAT3 and
STAT5, but not of STAT1 and STAT2. This inhibition is paralleled by the loss of
Jak1 and IFNAR1 tyrosine phosphorylation in response to IFNalpha, whereas Tyk2
and IFNAR2 tyrosine phosphorylation is unaffected. Last, the IFNalpha-induced
serine phosphorylation of STAT1 and STAT3 is not inhibited by piceatannol but is
sensitive to the Src kinase-specific inhibitor PP2. Thus, our results not only
demonstrate that the IFNalpha/beta receptor utilizes distinct mechanisms to
trigger the tyrosine phosphorylation of specific STAT proteins, but they also
indicate a diverging pathway that leads to the serine phosphorylation of STAT1
and STAT3.
PMID- 10777559
TI - Crk activation of JNK via C3G and R-Ras.
AB - v-crk is an oncogene identified originally in CT10 chicken tumor virus. C3G, a
guanine nucleotide exchange factor (GEF) for Rap1 and R-Ras, is postulated to
transduce the oncogenic signal of v-Crk to c-Jun kinase (JNK). We have found that
R-Ras, but not Rap1, mediates JNK activation by v-Crk in 293T and NIH 3T3 cells.
Constitutively activated R-Ras, R-Ras(Val-38), but not Rap1(Val-12), activated
JNK, as did the constitutively active H-Ras(Val-12) or Rac1(Val-12). v-Crk
activation of JNK was inhibited by a dominant-negative mutant of R-Ras, R-Ras(Asn
43). JNK activation by R-Ras(Val-38) was inhibited by a dominant-negative mutant
of mixed lineage kinase 3. Among six GEFs for Ras-family G proteins, mSos1, Ras
GRF, C3G, CalDAG-GEFI, Ras-GRP/CalDAG-GEFII, and Epac/cAMP-GEFI, GEFs for either
H-Ras or R-Ras activated JNK and c-Jun-dependent transcription. CalDAG-GEFI and
Epac/cAMP-GEFI, both of which are GEFs specific for Rap1, did not activate JNK or
c-Jun-dependent transcription. These results demonstrate that R-Ras, but not
Rap1, is the downstream effector of C3G to stimulate JNK. Finally, we found that
expression of the dominant-negative R-Ras mutant induced flat reversion of NIH
3T3 cells transformed by v-Crk, suggesting that R-Ras-dependent JNK activation is
critical for the transformation by v-Crk.
PMID- 10777560
TI - Three-dimensional clustering of human RAG2 gene mutations in severe combined
immune deficiency.
AB - The V(D)J recombination, which leads to the somatic rearrangement of variable,
diversity, and joining segments, is the mechanism accountable for the diversity
of T cell receptor- and Ig-encoding genes. The products of the RAG1 and RAG2
genes are the lymphoid-specific factors responsible for the initiation of the
V(D)J recombination through the generation of a DNA double strand break. RAG1 or
RAG2 gene inactivation in the mouse leads to abortion of the V(D)J rearrangement
process, early block in both T and B cell maturation, and, ultimately, to severe
combined immune deficiency (SCID). A human SCID condition is also characterized
by an absence of mature T and B lymphocytes and is associated with mutations in
either RAG1- or RAG2-encoding genes. Based on the predicted beta-propeller three
dimensional structure model for RAG2, we found that six out of the seven
mutations described to date in T-B-SCID patients are clustered on one side of the
propeller, in regions exposed to solvent. This finding reinforces the biological
significance of this predicted model and suggests that RAG1 interacts with RAG2
on one of the side of the scaffold formed by the beta-propeller.
PMID- 10777561
TI - Superinduction of CYP1A1 gene expression. Regulation of 2,3,7, 8
tetrachlorodibenzo-p-dioxin-induced degradation of Ah receptor by cycloheximide.
AB - Cycloheximide superinduces the transcription of CYP1A1 in the presence of an
agonist for the Ah receptor (AhR). To investigate the molecular target for
"superinduction," we analyzed the agonist-induced degradation of AhR. Whereas
2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD), a potent agonist of AhR, induces a
rapid reduction of the AhR protein, cycloheximide blocks the down-regulation of
steady state AhR. Analyses of the turnover of AhR reveal that cycloheximide
blocks the shortening of the half-life of AhR by TCDD. Blocking of the TCDD
induced AhR degradation requires inhibition of protein synthesis, because (a)
cycloheximide inhibits protein synthesis at the concentration at which it causes
superinduction and inhibition of AhR degradation; and (b) puromycin, an inhibitor
of protein synthesis by mimicking aminoacyl-tRNA, also blocks the TCDD-induced
AhR degradation. The blocking of the TCDD-induced AhR degradation correlates with
the superinduction of CYP1A1 gene expression in a time- and dose-dependent
manner. Furthermore, cycloheximide is shown to increase the accumulation of the
TCDD-activated AhR and the functional AhR x Arnt complex in nucleus.
Collectively, our results reveal a mechanism of superinduction by cycloheximide
by enhancing the stability of agonist-activated AhR. The finding that inhibition
of protein synthesis blocks the TCDD-induced AhR turnover implicates a
cycloheximide-sensitive, labile factor (designated as AhR degradation promoting
factor, or ADPF) in controlling the removal of agonist-activated AhR in nucleus.
PMID- 10777562
TI - Selective involvement of superoxide anion, but not downstream compounds hydrogen
peroxide and peroxynitrite, in tumor necrosis factor-alpha-induced apoptosis of
rat mesangial cells.
AB - Tumor necrosis factor-alpha (TNF-alpha) induces reactive oxygen species (ROS)
that serve as second messengers for intracellular signaling. Currently, precise
roles of individual ROS in the actions of TNF-alpha remain to be elucidated. In
this report, we investigated the roles of superoxide anion (O-(2)), hydrogen
peroxide (H(2)O(2)), and peroxynitrite (ONOO(-)) in TNF-alpha-triggered apoptosis
of mesangial cells. Mesangial cells stimulated by TNF-alpha produced O-(2) and
underwent apoptosis. The apoptosis was inhibited by transfection with manganese
superoxide dismutase or treatment with a pharmacological scavenger of O-(2),
Tiron. In contrast, although exogenous H(2)O(2) induced apoptosis, TNF-alpha
triggered apoptosis was not affected either by transfection with catalase cDNA or
by treatment with catalase protein or glutathione ethyl ester. Similarly,
although ONOO(-) precursor SIN-1 induced apoptosis, treatment with a scavenger of
ONOO(-), uric acid, or an inhibitor of nitric oxide synthesis, N(G)-nitro-L
argininemethyl ester hydrochloride, did not affect the TNF-alpha-triggered
apoptosis. Like TNF-alpha-induced apoptosis, treatment with a O-(2)-releasing
agent, pyrogallol, induced typical apoptosis even in the concurrent presence of
scavengers for H(2)O(2) and ONOO(-). These results suggested that, in mesangial
cells, TNF-alpha induces apoptosis through selective ROS. O-(2), but not H(2)O(2)
or ONOO(-), was identified as the crucial mediator for the TNF-alpha-initiated,
apoptotic pathway.
PMID- 10777563
TI - Hydrophobic pairwise interactions stabilize alpha-conotoxin MI in the muscle
acetylcholine receptor binding site.
AB - The present work delineates pairwise interactions underlying the nanomolar
affinity of alpha-conotoxin MI (CTx MI) for the alpha-delta site of the muscle
acetylcholine receptor (AChR). We mutated all non-cysteine residues in CTx MI,
expressed the alpha(2)betadelta(2) pentameric form of the AChR in 293 human
embryonic kidney cells, and measured binding of the mutant toxins by competition
against the initial rate of (125)I-alpha-bungarotoxin binding. The CTx MI
mutations P6G, A7V, G9S, and Y12T all decrease affinity for alpha(2)betadelta(2)
pentamers by 10,000-fold. Side chains at these four positions localize to a
restricted region of the known three-dimensional structure of CTx MI. Mutations
of the AChR reveal major contributions to CTx MI affinity by Tyr-198 in the alpha
subunit and by the selectivity determinants Ser-36, Tyr-113, and Ile-178 in the
delta subunit. By using double mutant cycles analysis, we find that Tyr-12 of CTx
MI interacts strongly with all three selectivity determinants in the delta
subunit and that deltaSer-36 and deltaIle-178 are interdependent in stabilizing
Tyr-12. We find additional strong interactions between Gly-9 and Pro-6 in CTx MI
and selectivity determinants in the delta subunit, and between Ala-7 and Pro-6
and Tyr-198 in the alpha subunit. The overall results reveal the orientation of
CTx MI when bound to the alpha-delta interface and show that primarily
hydrophobic interactions stabilize the complex.
PMID- 10777564
TI - Ca(2+)/calmodulin-dependent protein kinase II is stimulated by Wnt and Frizzled
homologs and promotes ventral cell fates in Xenopus.
AB - Wnt ligands working through Frizzled receptors have a differential ability to
stimulate release of intracellular calcium (Ca(2+)) and activation of protein
kinase C (PKC). Since targets of this Ca(2+) release could play a role in Wnt
signaling, we first tested the hypothesis that Ca(2+)/calmodulin-dependent
protein kinase II (CamKII) is activated by some Wnt and Frizzled homologs. We
report that Wnt and Frizzled homologs that activate Ca(2+) release and PKC also
activate CamKII activity in Xenopus embryos, while Wnt and Frizzled homologs that
activate beta-catenin function do not. This activation occurs within 10 min after
receptor activation in a pertussis toxin-sensitive manner, concomitant with
autophosphorylation of endogenous CamKII. Based on data that Wnt-5A and Wnt-11
are present maternally in Xenopus eggs, and activate CamKII, we then tested the
hypothesis that CamKII participates in axis formation in the early embryo.
Measurements of endogenous CamKII activity from dorsal and ventral regions of
embryos revealed elevated activity on the prospective ventral side, which was
suppressed by a dominant negative Xwnt-11. If this spatial bias in CamKII
activity were involved in promoting ventral cell fate one might predict that
elevating CamKII activity on the dorsal side would inhibit dorsal cell fates,
while reducing CamKII activity on the ventral side would promote dorsal cell
fates. Results obtained by expression of CamKII mutants were consistent with this
prediction, revealing that CamKII contributes to a ventral cell fate.
PMID- 10777565
TI - Identification of an enhancer sequence within the first intron required for
cartilage-specific transcription of the alpha2(XI) collagen gene.
AB - Type XI collagen, a heterotrimer composed of alpha1(XI), alpha2(XI) and
alpha3(XI), is primarily synthesized by chondrocytes in cartilage and is also
present in some other tissues. Type XI collagen plays a critical role in collagen
fibril formation and skeletal morphogenesis. We investigated a tissue-specific
transcriptional enhancer in the first intron of the alpha2(XI) collagen gene
(Col11a2). Transient transfection assays using reporter gene constructs revealed
that a 60-base pair (bp) segment within intron 1 increased promoter activity of
Col11a2 in rat chondrosarcoma cells but not in either BalB/3T3 cells or
undifferentiated ATDC5 cells, suggesting that it contained cell type-specific
enhancer activity. In transgenic mice, this 60-bp fragment was also able to
target beta-galactosidase expression to cartilage including the limbs and axial
skeleton, with similar localization specificity as the full-length intron 1
fragment. Competition experiments in gel shift assays using mutated
oligonucleotides showed that recombinant Sox9 bound to a 7-bp sequence, CTCAAAG,
within the 60-bp segment. Anti-Sox9 antibodies supershifted the complex of the 60
bp segment with recombinant Sox9 or with rat chondrosarcoma cell extracts,
confirming the binding of Sox9 to the enhancer. Moreover, a site-specific
mutation within the 7-bp segment resulted in essentially complete loss of the
enhancer activity in chondrosarcoma cells and transgenic mice. These results
suggest that the 7-bp sequence within intron 1 plays a critical role in the
cartilage-specific enhancer activity of Col11a2 through Sox9-mediated
transcriptional activation.
PMID- 10777566
TI - Assembly of type IV collagen. Insights from alpha3(IV) collagen-deficient mice.
AB - Type IV collagen includes six genetically distinct polypeptides named alpha1(IV)
through alpha6(IV). These isoforms are speculated to organize themselves into
unique networks providing mammalian basement membranes specificity and
inequality. Recent studies using bovine and human glomerular and testis basement
membranes have shown that unique networks of collagen comprising either alpha1
and alpha2 chains or alpha3, alpha4, and alpha5 chains can be identified. These
studies have suggested that assembly of alpha5 chain into type IV collagen
network is dependent on alpha3 expression where both chains are normally present
in the tissue. In the present study, we show that in the lens and inner ear of
normal mice, expression of alpha1, alpha2, alpha3, alpha4, and alpha5 chains of
type IV collagen can be detected using alpha chain-specific antibodies. In the
alpha3(IV) collagen-deficient mice, only the expression of alpha1, alpha2, and
alpha5 chains of type IV collagen was detectable. The non-collagenous 1 domain of
alpha5 chain was associated with alpha1 in the non-collagenous 1 domain hexamer
structure, suggesting that network incorporation of alpha5 is possible in the
absence of the alpha3 chain in these tissues. The present study proves that
expression of alpha5 is not dependent on the expression of alpha3 chain in these
tissues and that alpha5 chain can assemble into basement membranes in the absence
of alpha3 chain. These findings support the notion that type IV collagen assembly
may be regulated by tissue-specific factors.
PMID- 10777567
TI - Interaction of the N-methyl-D-aspartic acid receptor NR2D subunit with the c-Abl
tyrosine kinase.
AB - The COOH-terminal domain of the NR2D subunit of the NMDA receptor contains
proline-rich regions that show striking homology to sequences known to bind to
Src homology 3 (SH3) domains. To determine whether the proline-rich region of the
NR2D subunit interacts with specific SH3 domains, in vitro SH3 domain binding
assays were performed. A proline-rich fragment of the NR2D subunit (2D(866-1064))
bound to the Abl SH3 domain but not to the SH3 domains from Src, Fyn, Grb2, GAP,
or phospholipase C-gamma (PLCgamma). Co-immunoprecipitation of NR2D with Abl
suggests stable association of NR2D and Abl in transfected cells. The SH3 domain
plays an important role in the negative regulation of Abl kinase activity. To
determine whether the interaction of NR2D with the Abl SH3 domain alters Abl
kinase activity, Abl was expressed alone or with NR2D in 293T cells.
Autophosphorylation of Abl was readily observed when Abl was expressed alone.
However, co-expression of Abl with 2D(866-1064) or full-length NR2D inhibited
autophosphorylation. 2D(866-1064) did not inhibit DeltaSH3 Abl, indicating a
requirement for the Abl SH3 domain in the inhibitory effect. Similarly, 2D(866
1064) did not inhibit the catalytic activity of Abl-PP, which contains two point
mutations in the SH2-kinase linker domain that release the negative kinase
regulation by the SH3 domain. In contrast, the full-length NR2D subunit partially
inhibited the autokinase activity of both DeltaSH3 Abl and Abl-PP, suggesting
that NR2D and Abl may interact at multiple sites. Taken together, the data in
this report provide the first evidence for a novel inhibitory interaction between
the NR2D subunit of the NMDA receptor and the Abl tyrosine kinase.
PMID- 10777568
TI - Discovery of molecular and catalytic diversity among human diphosphoinositol
polyphosphate phosphohydrolases. An expanding Nudt family.
AB - The turnover of the "high energy" diphosphoinositol polyphosphates by Ca(2+)- and
cyclic nucleotide-modulated enzymes is considered a regulatory, molecular
switching activity. Target processes may include intracellular trafficking.
Following our earlier identification of a prototype human diphosphoinositol
polyphosphate phosphohydrolase (hDIPP1), we now describe new 21-kDa human
isoforms, hDIPP2alpha and hDIPP2beta, distinguished from each other solely by
hDIPP2beta possessing one additional amino acid (Gln(86)). Candidate DIPP2alpha
and DIPP2beta homologues in rat and mouse were also identified. The rank order
for catalytic activity is hDIPP1 > hDIPP2alpha > hDIPP2beta. Differential
expression of hDIPP isoforms may provide flexibility in response times of the
molecular switches. The 76% identity between hDIPP1 and the hDIPP2s includes
conservation of an emerging signature sequence, namely, a Nudt (MutT) motif with
a GX(2)GX(6)G carboxy extension. Northern and Western analyses indicate
expression of hDIPP2s is broad but atypically controlled; these proteins are
translated from multiple mRNAs that differ in the length of the 3'-untranslated
region because of utilization of an array of alternative (canonical and
noncanonical) polyadenylation signals. Thus, cells can recruit sophisticated
molecular processes to regulate diphosphoinositol polyphosphate turnover.
PMID- 10777569
TI - NF-kappaB inhibits apoptosis in murine mammary epithelia.
AB - The transcription factor NF-kappaB is a key modulator of apoptosis in a variety
of cell types, but to date this specific function of NF-kappaB has not been
demonstrated in epithelia. Here, we describe the activation of NF-kappaB during
post-lactational involution of the mouse mammary gland, a period of extensive
apoptosis of luminal epithelial cells. Significantly, active NF-kappaB localized
exclusively to nonapoptotic epithelial cells both in vivo and in the mammary
epithelial cell line, KIM-2, transduced with an NF-kappaB-dependent green
fluorescent protein reporter. Activation of NF-kappaB in vitro coincided with a
decrease in the cytosolic repressor, IkappaBalpha. Furthermore, induction of NF
kappaB either by extracellular ligands or, more specifically, by inhibition of
the IkappaB repressor with adenoviral constructs expressing antisense mRNA,
resulted in enhanced survival of KIM-2 cells. Therefore, although coincident with
induction of apoptosis both in vivo and in vitro, NF-kappaB appeared to exert a
selective survival function in epithelial cells. This study highlights for the
first time a role for NF-kappaB in modulating apoptosis in epithelium.
PMID- 10777570
TI - Successful targeting to rat hepatic stellate cells using albumin modified with
cyclic peptides that recognize the collagen type VI receptor.
AB - The key pathogenic event in liver fibrosis is the activation of hepatic stellate
cells (HSC). Consequently, new antifibrotic therapies are directed toward an
inhibition of HSC activities. The aim of the present study was to develop a drug
carrier to HSC, which would allow cell-specific delivery of antifibrotic drugs
thus enhancing their effectiveness in vivo. We modified human serum albumin (HSA)
with 10 cyclic peptide moieties recognizing collagen type VI receptors
(C*GRGDSPC*, in which C* denotes the cyclizing cysteine residues) yielding pCVI
HSA. In vivo experiments showed preferential distribution of pCVI-HSA to both
fibrotic and normal rat livers (respectively, 62 +/- 6 and 75 +/- 16% of the dose
at 10 min after intravenous injection). Immunohistochemical analysis demonstrated
that pCVI-HSA predominantly bound to HSC in fibrotic livers (73 +/- 14%). In
contrast, endothelial cells contributed mostly to the total liver accumulation in
normal rats. In vitro studies showed that pCVI-HSA specifically bound to rat HSC,
in particular to the activated cells, and showed internalization of pCVI-HSA by
these cells. In conclusion, pCVI-HSA may be applied as a carrier to deliver
antifibrotic agents to HSC, which may strongly enhance the effectiveness and
tissue selectivity of these drugs. This approach has the additional benefit that
such carriers may block receptors that play a putative role in the pathogenesis
of liver fibrosis.
PMID- 10777571
TI - SCAMP1 function in endocytosis.
AB - Secretory carrier membrane proteins (SCAMPs) are ubiquitous components of
recycling vesicles that shuttle between the plasma membrane, endosomes, and the
trans-Golgi complex. SCAMPs contain multiple N-terminal NPF repeats and four
highly conserved transmembrane regions. NPF repeats often interact with EH domain
proteins that function in budding of transport vesicles from the plasma membrane
or the Golgi complex. We now show that the NPF repeats of SCAMP1 bind to two EH
domain proteins, intersectin 1, which is involved in endocytic budding at the
plasma membrane, and gamma-synergin, which may mediate the budding of vesicles in
the trans-Golgi complex. Expression of SCAMP1 lacking the N-terminal NPF repeats
potently inhibited transferrin uptake by endocytosis. Our data suggest that one
of the functions of SCAMPs is to participate in endocytosis via a mechanism which
may involve the recruitment of clathrin coats to the plasma membrane and the
trans-Golgi network.
PMID- 10777572
TI - ATPase activity of a highly stable alpha(3)beta(3)gamma subcomplex of
thermophilic F(1) can be regulated by the introduced regulatory region of gamma
subunit of chloroplast F(1).
AB - A mutant F(1)-ATPase alpha(3)beta(3)gamma subcomplex from the thermophilic
Bacillus PS3 was constructed, in which 111 amino acid residues (Val(92) to
Phe(202)) from the central region of the gamma subunit were replaced by the 148
amino acid residues of the homologous region from spinach chloroplast F(1)-ATPase
gamma subunit, including the regulatory stretch, and were designated as
alpha(3)beta(3)gamma((TCT)) (Thermophilic-Chloroplast-Thermophilic). By the
insertion of this regulatory region into the gamma subunit of thermophilic F(1),
we could confer the thiol modulation property to the thermophilic
alpha(3)beta(3)gamma subcomplex. The overexpressed alpha(3)beta(3)gamma((TCT))
was easily purified in large scale, and the ATP hydrolyzing activity of the
obtained complex was shown to increase up to 3-fold upon treatment with
chloroplast thioredoxin-f and dithiothreitol. No loss of thermostability compared
with the wild type subcomplex was found, and activation by dithiothreitol was
functional at temperatures up to 80 degrees C. alpha(3)beta(3)gamma((TCT)) was
inhibited by the epsilon subunit from chloroplast F(1)-ATPase but not by the one
from the thermophilic F(1)-ATPase, indicating that the introduced amino acid
residues from chloroplast F(1)-gamma subunit are important for functional
interaction with the epsilon subunit.
PMID- 10777573
TI - Modeling and functional analysis of the interaction between von Willebrand factor
A1 domain and glycoprotein Ibalpha.
AB - Binding of the von Willebrand factor (vWF) A1 domain to the glycoprotein (GP) Ib
IX-V complex mediates platelet adhesion to reactive substrates under high shear
stress conditions, a key event in hemostasis and thrombosis. We have now used the
known three-dimensional structure of the A1 domain to model the interaction with
the GP Ibalpha sequence 271-279, which has previously been implicated in ligand
binding. Docking procedures suggested that A1 domain residues in strand beta3 and
preceding loop (residues 559-566) as well as in helix alpha3 (residues 594-603)
interact with Asp residues 272, 274, 277 and sulfated Tyr residues 278 and 279 in
GP Ibalpha. To verify this model, 14 mutant A1 domain fragments containing single
or multiple side chain substitutions were tested for their ability to mediate
platelet adhesion under flow. Each of the vWF residues Tyr(565), Glu(596), and
Lys(599) proved to be strictly required for A1 domain function, which, in
agreement with previous findings, was also dependent on Gly(561). Moreover, an
accessory functional role was apparent for a group of positively charged
residues, including Arg at positions 629, 632, 636 and Lys at positions 643 and
645, possibly acting in concert. There was, however, no evidence from the model
that these residues directly participate in forming the complex with GP Ibalpha.
These results provide a partial model of the vWF-GP Ibalpha interaction linked to
the manifestation of functional activity in platelet adhesion.
PMID- 10777574
TI - High density lipoprotein-mediated cholesterol uptake and targeting to lipid
droplets in intact L-cell fibroblasts. A single- and multiphoton fluorescence
approach.
AB - Fluorescent sterols, dehydroergosterol and NBD-cholesterol, were used to examine
high density lipoprotein-mediated cholesterol uptake and intracellular targeting
in L-cell fibroblasts. The uptake, but not esterification or targeting to lipid
droplets, of these sterols differed >100-fold, suggesting significant differences
in uptake pathways. NBD-cholesterol uptake kinetics and lipoprotein specificity
reflected high density lipoprotein-mediated sterol uptake via the scavenger
receptor B1. Fluorescence energy transfer showed an average intermolecular
distance of 26 A between the two fluorescent sterols in L-cells. Indirect
immunofluorescence revealed that both fluorescent sterols localized to L-cell
lipid droplets, the surface of which contained adipose differentiation-related
protein. This lipid droplet-specific protein specifically bound NBD-cholesterol
with high affinity (K(d) = 2 nM) at a single site. Thus, NBD-cholesterol and
dehydroergosterol were useful fluorescent probes of sterol uptake and
intracellular sterol targeting. NBD-cholesterol more selectively probed high
density lipoprotein-mediated uptake and rapid intracellular targeting of sterol
to lipid droplets. Targeting of sterol to lipid droplets was correlated with the
presence of adipose differentiation related protein, a lipid droplet-specific
protein shown for the first time to bind unesterified sterol with high affinity.
PMID- 10777575
TI - Calcium binding to the photosystem II subunit CP29.
AB - We have identified a Ca(2+)-binding site of the 29-kDa chlorophyll a/b-binding
protein CP29, a light harvesting protein of photosystem II most likely involved
in photoregulation. (45)Ca(2+) binding studies and dot blot analyses of CP29
demonstrate that CP29 is a Ca(2+)-binding protein. The primary sequence of CP29
does not exhibit an obvious Ca(2+)-binding site therefore we have used Yb(3+)
replacement to analyze this site. Near-infrared Yb(3+) vibronic side band
fluorescence spectroscopy (Roselli, C., Boussac, A., and Mattioli, T. A. (1994)
Proc. Natl. Acad. Sci. U. S. A. 91, 12897-12901) of Yb(3+)-reconstituted CP29
indicated a single population of Yb(3+)-binding sites rich in carboxylic acids,
characteristic of Ca(2+)-binding sites. A structural model of CP29 presents two
purported extra-membranar loops which are relatively rich in carboxylic acids,
one on the stromae side and one on the lumenal side. The loop on the lumenal side
is adjacent to glutamic acid 166 in helix C of CP29, which is known to be the
binding site for dicyclohexylcarbodiimide (Pesaresi, P., Sandona, D., Giuffra, E.
, and Bassi, R. (1997) FEBS Lett. 402, 151-156). Dicyclohexylcarbodiimide binding
prevented Ca(2+) binding, therefore we propose that the Ca(2+) in CP29 is bound
in the domain including the lumenal loop between helices B and C.
PMID- 10777576
TI - The functional role of basic patch, a structural element of Escherichia coli
transcript cleavage factors GreA and GreB.
AB - The transcript cleavage factors GreA and GreB of Escherichia coli are involved in
the regulation of transcription elongation. The surface charge distribution
analysis of their three-dimensional structures revealed that the N-terminal
domains of GreA and GreB contain a small and large basic "patch," respectively.
To elucidate the functional role of basic patch, mutant Gre proteins were
engineered in which the size and charge distribution of basic patch were modified
and characterized biochemically. We found that Gre mutants lacking basic patch or
carrying basic patch of decreased size bind to RNA polymerase and induce
transcript cleavage reaction in minimally backtracked ternary elongation complex
(TEC) with the same efficiency as the wild type factors. However, they exhibit
substantially lower readthrough and cleavage activities toward extensively
backtracked and arrested TECs and display decreased efficiency of photocross
linking to the RNA 3'-terminus. Unlike wild type factors, basic patch-less Gre
mutants are unable to complement the thermosensitive phenotype of GreA(-):GreB(-)
E. coli strain. The large basic patch is required but not sufficient for the
induction of GreB-type cleavage reaction and for the cleavage of arrested TECs.
Our results demonstrate that the basic patch residues are not directly involved
in the induction of transcript cleavage reaction and suggest that the primary
role of basic patch is to anchor the nascent RNA in TEC. These interactions are
essential for the readthrough and antiarrest activities of Gre factors and,
apparently, for their in vivo functions.
PMID- 10777577
TI - Alpha(1)-proteinase inhibitor, alpha(1)-antichymotrypsin, or alpha(2)
macroglobulin is required for vascular smooth muscle cell spreading in three
dimensional fibrin gel.
AB - It is assumed that vitronectin and other adhesion molecules induce cell
spreading. We found that vascular smooth muscle cells require unidentified plasma
components besides adhesion molecules to spread in fibrin gel, a likely
provisional matrix at wound sites. By purification, the plasma components were
found to be alpha(1)-proteinase inhibitor, alpha(1)-antichymotrypsin, and
alpha(2)-macroglobulin. The chemically inactivated alpha(1)-proteinase inhibitor
and alpha(2)-macroglobulin lose the spreading activity, indicating that these
proteins function as proteinase inhibitors but not as adhesion molecules. Not
only anti-integrin (alpha(v)beta(3) and alpha(5)beta(1)) antibodies but also anti
fibronectin antibodies inhibit the cell spreading. The spreading occurs without
the addition of fibronectin and integrins, suggesting that cells produce these
molecules. In the absence of the proteinase inhibitors, Western blot analysis
shows that the fibronectin is degraded in fibrin gel, while it is intact in the
presence of the inhibitors. Thus, the proteinase inhibitors prevent adhesion
molecules such as fibronectin from being degraded by a cell-derived proteinase(s)
and thus play a role in cell spreading.
PMID- 10777578
TI - Human procathepsin B interacts with the annexin II tetramer on the surface of
tumor cells.
AB - To study potential roles of plasma membrane-associated extracellular cathepsin B
in tumor cell invasion and metastasis, we used the yeast two-hybrid system to
screen for proteins that interact with human procathepsin B. The annexin II light
chain (p11), one of the two subunits of the annexin II tetramer, was one of the
proteins identified. We have confirmed that recombinant human procathepsin B
interacts with p11 as well as with the annexin II tetramer in vitro. Furthermore,
procathepsin B could interact with the annexin II tetramer in vivo as
demonstrated by coimmunoprecipitation. Cathepsin B and the annexin II tetramer
were shown by immunofluorescent staining to colocalize on the surface of human
breast carcinoma and glioma cells. Taken together, our results indicate that the
annexin II tetramer can serve as a binding protein for procathepsin B on the
surface of tumor cells, an interaction that may facilitate tumor invasion and
metastasis.
PMID- 10777579
TI - Thermodynamic consequences of grafting enhanced affinity toward the mutated
antigen onto an antibody. The case of anti-lysozyme antibody, HyHEL-10.
AB - In order to address the mechanism of enhancement of the affinity of an antibody
toward an antigen from a thermodynamic viewpoint, anti-hen lysozyme (HEL)
antibody HyHEL-10, which also recognize the mutated antigen turkey lysozyme (TEL)
with reduced affinity, was examined. Grafting high affinity toward TEL onto HyHEL
10 was performed by saturation mutagenesis into four residues (Tyr(53), Ser(54),
Ser(56), and Tyr(58)) in complementarity-determining region 2 of the heavy chain
(CDR-H2) followed by selection with affinity for TEL. Several clones enriched
have a Phe residue at site 58. Thermodynamic analyses showed that the clones
selected had experienced a greater than 3-fold affinity increase toward TEL in
comparison with wild-type Fv, originating from an increase in negative enthalpy
change. Substitution of HyHEL-10 HTyr(58) with Phe led to the increase in
negative enthalpy change and to almost identical affinity for TEL in comparison
with mutants selected, indicating that mutations at other sites decrease the
entropy loss despite little contribution to the affinity for TEL. These results
suggest that the affinity of an antibody toward the antigen is enhanced by the
increase in enthalpy change by some limited mutation, and excess entropy loss due
to the mutation is decreased by other energetically neutral mutations.
PMID- 10777580
TI - Cloning and characterization of the murine glucosamine-6-phosphate
acetyltransferase EMeg32. Differential expression and intracellular membrane
association.
AB - N-Linked glycosylation is a post-translational modification occurring in many
eukaryotic secreted and surface-bound proteins and has impact on diverse
physiological and pathological processes. Similarly important is the generation
of glycosylphosphatidylinositol linkers, which anchor membrane proteins to the
cell. Both protein modifications depend on the central nucleotide sugar UDP-N
acetylglucosamine (UDP-GlcNAc). The enzymatic reactions leading to generation of
nucleotide sugars are established, yet most of the respective genes still await
cloning. We describe the characterization of such a gene, EMeg32, which we
identified based on its differential expression in murine hematopoietic precursor
cells. We further demonstrate regulated expression during embryogenesis. EMeg32
codes for a 184-amino acid protein exhibiting glucosamine-6-phosphate
acetyltransferase activity. It thereby holds a key position in the pathway toward
de novo UDP-GlcNAc synthesis. Surprisingly, the protein associates with the
cytoplasmic side of various intracellular membranes, accumulates prior to
mitosis, and copurifies with the cdc48 homolog p97/valosin-containing protein.
PMID- 10777581
TI - The GPI-linked Ly-6 antigen E48 regulates expression levels of the FX enzyme and
of E-selectin ligands on head and neck squamous carcinoma cells.
AB - By differential display we demonstrated that antibody-mediated ligation of the
GPI-linked protein product of E48, a newly discovered human Ly-6 gene, up
regulates the expression of the FX enzyme in 3 lines of head and neck squamous
carcinoma cells. FX is responsible for the last step in the synthesis of GDP-L
fucose. The up-regulation of FX was E48 ligand-specific. 22AWT head and neck
squamous carcinoma cells expressing high levels of E48 expressed significantly
higher levels of FX than the E48 antisense transfected 22AWT cells (8-3 cells).
The former cells also expressed higher levels of two major fucosylated glycans
(the selectin ligand, Sialyl Lewis a, and VIM-2) than the E48 antisense
transfectants. Conversely, transfection of cells from the 14CWT line expressing
very low levels of E48 with E48 cDNA caused an up-regulated expression of FX and
of the two fucosylated glycans in the 14C-CMV16 transfectants. Moreover, the
expression levels of Sialyl Lewis a was significantly up-regulated on HNSCC upon
ligation of E48 by anti-E48 antibodies. The functional significance of the E48
mediated up-regulation of Sialyl Lewis a was demonstrated in rolling experiments
on E-selectin bearing surfaces under physiological conditions of shear flow and
on tumor necrosis factor alpha-activated human umbilical venous endothelial
cells. Only high E48/FX/Sialyl Lewis a expressing 14C-CMV16 cells could roll on
purified E-selectin or establish E-selectin dependent rolling on the activated
human umbilical venous endothelial cells. Low E48/FX/Sialyl Lewis a expressing
14CWT cells did not roll. These results show that E48 controls the expression of
the FX enzyme and of certain fucosylated E-selectin ligands by HNSCC. E48 may
thus function as a key regulator of the adhesiveness of these tumor cells to
inflamed vessel walls expressing E-selectin.
PMID- 10777582
TI - Identification and cloning of a new calmodulin-like protein from human epidermis.
AB - After separating by two-dimensional gel electrophoresis an extract of total
proteins from human stratum corneum, two spots were extracted and analyzed for
their peptide sequence. The resulting internal protein sequences provided
evidence for the identification of a new calcium-binding protein. Cloning of the
corresponding full-length cDNA was achieved by reverse transcriptase-polymerase
chain reaction using two keratinocyte libraries, one from proliferating cultured
keratinocytes and one from differentiated keratinocytes of reconstructed human
epidermis. The cDNA had an open reading frame encoding a new calcium-binding
protein of 146 amino acids, a member of the calmodulin family. We named this new
protein calmodulin-like skin protein (CLSP), since reverse transcriptase
polymerase chain reaction studies of CLSP expression in 10 different human
tissues revealed that this protein was particularly abundant in the epidermis
where its expression is directly related to keratinocyte differentiation.
Expression of the cloned cDNA in Escherichia coli yielded a recombinant protein
which allowed its further characterization. rCLSP is able to bind calcium, and
similarly to calmodulin, exposes thereafter hydrophobic parts which most likely
interact with target proteins. Epidermal proteins retained by CaM affinity column
are quantitatively and qualitatively distinct from those of the rCLSP column.
Sequencing of a rCLSP affinity purified protein revealed 100% identity with
transglutaminase 3, a key enzyme in terminal differentiation, indicating an
important role of CLSP in this process.
PMID- 10777583
TI - SOCS3 exerts its inhibitory function on interleukin-6 signal transduction through
the SHP2 recruitment site of gp130.
AB - Interleukin-6 is involved in the regulation of many biological activities such as
gene expression, cell proliferation, and differentiation. The control of the
termination of cytokine signaling is as important as the regulation of initiation
of signal transduction pathways. Three families of proteins involved in the down
regulation of cytokine signaling have been described recently: (i) SH2 domain
containing protein-tyrosine phosphatases (SHP), (ii) suppressors of cytokine
signaling (SOCS), and (iii) protein inhibitors of activated STATs (PIAS). We have
analyzed the interplay of two inhibitors in the signal transduction pathway of
interleukin-6 and demonstrate that the tyrosine phosphatase SHP2 and SOCS3 do not
act independently but are functionally linked. The activation of one inhibitor
modulates the activity of the other; Inhibition of SHP2 activation leads to
increased SOCS3-mRNA levels, whereas increased expression of SOCS3 results in a
reduction of SHP2 phosphorylation after activation of the interleukin-6 signal
transduction pathway. Furthermore, we show that tyrosine 759 in gp130 is
essential for both SHP2 and SOCS3 but not for SOCS1 to exert their inhibitory
activities on interleukin-6 signal transduction. Besides SHP2, SOCS3 also
interacts with the Tyr(P)-759 peptide of gp130. Taken together, our results
suggest differences in the function of SOCS1 and SOCS3 and a link between SHP2
and SOCS3.
PMID- 10777584
TI - Identification of a novel SCAN box-related protein that interacts with MZF1B. The
leucine-rich SCAN box mediates hetero- and homoprotein associations.
AB - The SCAN box or leucine-rich (LeR) domain is a conserved motif found within a
subfamily of C(2)H(2) zinc finger proteins. The function of a SCAN box is
unknown, but it is predicted to form alpha-helices that may be involved in
protein-protein interactions. Myeloid zinc finger gene-1B (MZF1B) is an
alternatively spliced human cDNA isoform of the zinc finger transcription factor,
MZF1. MZF1 and MZF1B contain 13 C(2)H(2) zinc finger motifs, but only MZF1B
contains an amino-terminal SCAN box. A bone marrow cDNA library was screened for
proteins interacting with the MZF1B SCAN box domain and RAZ1 (SCAN-related
protein associated with MZF1B) was identified. RAZ1 is a novel cDNA that encodes
a SCAN-related domain and arginine-rich region but no zinc finger motifs. Co
immunoprecipitation assays demonstrate that the SCAN box domain of MZF1B is
necessary for association with RAZ1. By yeast two-hybrid analysis, the carboxyl
terminus of RAZ1 is sufficient for interaction with the MZF1B SCAN box.
Furthermore, MZF1B and RAZ1 each self-associate in vitro via a SCAN box-dependent
mechanism. These data provide evidence that the SCAN box is a protein interaction
domain that mediates both hetero- and homoprotein associations.
PMID- 10777585
TI - Roles of thermal instability and proteolytic cleavage in regulation of activated
thrombin-activable fibrinolysis inhibitor.
AB - We have used site-directed mutagenesis and a recombinant expression system for
thrombin-activable fibrinolysis inhibitor (TAFI) in order to identify the
thrombin cleavage site in activated TAFI (TAFIa) and to determine the relative
contribution of proteolytic cleavage and thermal instability in regulation of
TAFIa activity in clots. Arg-330 of TAFIa had been proposed to be the thrombin
cleavage site based on studies with trypsin, but mutation of this residue to Gln
did not prevent thrombin-mediated cleavage nor did mutation to Gln of the nearby
Arg-320 residue. However, mutation of Arg-302 to Gln abolished thrombin-mediated
cleavage of TAFIa. All TAFIa variants were susceptible to plasmin cleavage.
Interestingly, all Arg to Gln substitutions decreased the thermal stability of
TAFIa. The antifibrinolytic potential of the TAFI mutants in vitro correlates
with the thermal stability of their respective TAFIa species, indicating that
this property plays a key role in regulating the activity if TAFIa. Incubation of
TAFIa under conditions that result in complete thermal inactivation of the enzyme
accelerates subsequent thrombin- and plasmin-mediated cleavage of TAFIa.
Moreover, the extent of cleavage of TAFIa by thrombin does not affect the rate of
decay of TAFIa activity. Collectively, these studies point to a role for the
thermal instability, but not for proteolytic cleavage, of TAFIa in regulation of
its activity and, thus, of its antifibrinolytic potential. Finally, we propose a
model for the thermal instability of TAFIa.
PMID- 10777586
TI - The zinc finger repressor, ZBP-89, binds to the silencer element of the human
vimentin gene and complexes with the transcriptional activator, Sp1.
AB - Vimentin is a component of the eukaryotic cytoskeleton belonging to the family of
intermediate filament proteins. It exhibits a complex pattern of tissue- and
development-specific expression. It is also a marker of the metastatic potential
of many tumor cells. Previously, the human vimentin promoter was shown to contain
several regions for the binding of positive and negative acting regulatory
factors. Until now, the silencer element, which shuts down vimentin synthesis in
selected tissues during development, was not precisely localized; nor was its
binding protein known. In vivo DMS footprinting by ligation-mediated PCR
delineated the position of guanine residues important to vimentin expression.
Transient transfection assays in HeLa cells of various vimentin 5'-end promoter
sequences and mutants thereof precisely defined two regulatory elements, a
negative element and an adjoining positive acting element. Band shift assays, UV
cross-linking, and Southwestern blot analysis confirm that the silencer element
specifically binds a protein. Several lines of evidence show that ZBP-89, a zinc
finger, Kruppel-like repressor protein is vimentin's silencer element binding
factor. Co-immunoprecipitation and DNA affinity chromatography prove that Sp1
heterodimerizes with ZBP-89 when bound to the silencer element to yield a DNA
protein complex whose mobility is indistinguishable from that displayed by HeLa
nuclear extract in band shift assays.
PMID- 10777587
TI - The tumor suppressor PTEN negatively regulates insulin signaling in 3T3-L1
adipocytes.
AB - PTEN is a tumor suppressor with sequence homology to protein-tyrosine
phosphatases and the cytoskeleton protein tensin. PTEN is capable of
dephosphorylating phosphatidylinositol 3,4, 5-trisphosphate in vitro and down
regulating its levels in insulin-stimulated 293 cells. To study the role of PTEN
in insulin signaling, we overexpressed PTEN in 3T3-L1 adipocytes approximately 30
fold above uninfected or control virus (green fluorescent protein)-infected
cells, using an adenovirus gene transfer system. PTEN overexpression inhibited
insulin-induced 2-deoxy-glucose uptake by 36%, GLUT4 translocation by 35%, and
membrane ruffling by 50%, all of which are phosphatidylinositol 3-kinase
dependent processes, compared with uninfected cells or cells infected with
control virus. Microinjection of an anti-PTEN antibody increased basal and
insulin stimulated GLUT4 translocation, suggesting that inhibition of endogenous
PTEN function led to an increase in intracellular phosphatidylinositol 3,4,5
trisphosphate levels, which stimulates GLUT4 translocation. Further, insulin
induced phosphorylation of downstream targets Akt and p70S6 kinase were also
inhibited significantly by overexpression of PTEN, whereas tyrosine
phosphorylation of the insulin receptor and IRS-1 or the phosphorylation of
mitogen-activated protein kinase were not affected, suggesting that the
Ras/mitogen-activated protein kinase pathway remains fully functional. Thus, we
conclude that PTEN may regulate phosphatidylinositol 3-kinase-dependent insulin
signaling pathways in 3T3-L1 adipocytes.
PMID- 10777588
TI - The Elp2 subunit of elongator and elongating RNA polymerase II holoenzyme is a
WD40 repeat protein.
AB - A novel yeast gene, ELP2, is shown to encode the 90-kDa subunit of the Elongator
complex and elongating RNA polymerase II holoenzyme. ELP2 encodes a protein with
eight WD40 repeats, and cells lacking the gene display typical elp phenotypes,
such as temperature and salt sensitivity. Generally, different combinations of
double and triple ELP gene deletions cause the same phenotypes as single ELP1,
ELP2, or ELP3 deletion, providing genetic evidence that the ELP gene products
work together in a complex.
PMID- 10777589
TI - Selective regulation of endogenous G protein-coupled receptors by arrestins in
HEK293 cells.
AB - Arrestins play an important role in regulating desensitization and trafficking of
G protein-coupled receptors (GPCRs). However, limited insight into the
specificity of arrestin-mediated regulation of GPCRs is currently available.
Recently, we used an antisense strategy to reduce arrestin levels in HEK293 cells
and characterize the role of arrestins on endogenous G(s)-coupled receptors
(Mundell, S. J., Loudon, R. B., and Benovic, J. L. (1999) Biochemistry 38, 8723
8732). Here, we characterized GPCRs coupled to either G(q) (M(1) muscarinic
acetylcholine receptor (M(1)AchR) and P2y(1) and P2y(2) purinergic receptors) or
G(i) (somatostatin and AT1 angiotensin receptors) in wild type and arrestin
antisense HEK293 cells. The agonist-specific desensitization of the M(1)Ach and
somatostatin receptors was significantly attenuated in antisense-expressing
cells, whereas desensitization of P2y(1) and P2y(2) purinergic and AT1
angiotensin receptors was unaffected by reduced arrestin levels. To further
examine arrestin/GPCR specificity, we studied the effects of endogenous GPCR
activation on the redistribution of arrestin-2 epitope tagged with the green
fluorescent protein (arrestin-2-GFP). These studies revealed a receptor-specific
movement of arrestin-2-GFP that mirrored the arrestin-receptor specificity
observed in the antisense cells. Thus, agonist-induced activation of endogenous
beta(2)-adrenergic, prostaglandin E(2), M(1)Ach, and somatostatin receptors
induced arrestin-2-GFP redistribution to early endosomes, whereas P2y(1) and
P2y(2) purinergic and AT1 angiotensin receptor activation did not. Thus,
endogenous arrestins mediate the regulation of selective G(q)- and G(i)-coupled
receptors in HEK293 cells.
PMID- 10777590
TI - FHX, a novel fork head factor with a dual DNA binding specificity.
AB - The HNF3/fork head family includes a large number of transcription factors that
share a structurally related DNA binding domain. Fork head factors have been
shown to play important roles both during development and in the adult. We now
describe the cloning of a novel mammalian fork head factor that we have named FHX
(fork head homologous X (FHX), which is expressed in many adult tissues. In the
embryo, FHX expression showed a very early onset during the cleavage stages of
preimplantation development. Polymerase chain reaction-assisted site selection
experiments showed that FHX bound DNA with a dual sequence specificity. Sites
recognized by FHX could be classified into two different types according to their
sequences. Binding of FHX to sequences of each type appeared to occur
independently. Our data suggest that either different regions of the fork head
domain or different molecular forms of this domain could be involved in binding
of FHX to each type of site. In transfection assays, FHX was capable of
activating transcription from promoters containing FHX sites of either type.
PMID- 10777591
TI - Mechanistic studies of the effects of anti-factor H antibodies on complement
mediated lysis.
AB - We have recently reported that complement factor H, a negative regulator of
complement-mediated cytotoxicity, is produced and secreted by most bladder
cancers. This observation was exploited in the development of the BTA stat and
BTA TRAK diagnostic assays, both of which make use of two factor H-specific
monoclonal antibodies in sandwich format. Here we show that both antibodies exert
interesting effects on the biochemistry of complement activation in in vitro
systems. Antibody X13.2 competes with C3b for association with factor H and
strongly inhibits factor H/factor I-mediated cleavage of C3b, thereby evidently
inactivating a negative regulator of complement; yet, the antibody strongly
inhibits complement-mediated lysis as well. Conversely, antibody X52. 1, which
does not compete with C3b and has no effect on solution-phase cleavage of C3b, is
capable of enhancing complement-mediated lysis of various cell types, including
cancer cells, by over 10-fold. Our observations indicate that it is possible to
deconvolute the biochemical roles of factor H in complement by means of
appropriate inhibitors, a finding with potentially valuable implications for both
basic research and cancer therapy.
PMID- 10777592
TI - Reversible transdominant inhibition of a metabolic pathway. In vivo evidence of
interaction between two sequential tricarboxylic acid cycle enzymes in yeast.
AB - The enzymes of the Krebs tricarboxylic acid cycle in mitochondria are proposed to
form a supramolecular complex, in which there is channeling of intermediates
between enzyme active sites. While interactions have been demonstrated in vitro
between most of the sequential tricarboxylic acid cycle enzymes, no direct
evidence has been obtained in vivo for such interactions. We have isolated, in
the Saccharomyces cerevisiae gene encoding the tricarboxylic acid cycle enzyme
citrate synthase Cit1p, an "assembly mutation," i.e. a mutation that causes a
tricarboxylic acid cycle deficiency without affecting the citrate synthase
activity. We have shown that a 15-amino acid peptide from wild type Cit1p
encompassing the mutation point inhibits the tricarboxylic acid cycle in a
dominant manner, and that the inhibitory phenotype is overcome by a co
overexpression of Mdh1p, the mitochondrial malate dehydrogenase. These data
provide the first direct in vivo evidence of interaction between two sequential
tricarboxylic acid cycle enzymes, Cit1p and Mdh1p, and indicate that the
characterization of assembly mutations by the reversible transdominant inhibition
method may be a powerful way to study multienzyme complexes in their
physiological context.
PMID- 10777593
TI - The role of transcription factor B in transcription initiation and promoter
clearance in the archaeon Sulfolobus acidocaldarius.
AB - Mechanisms of transcription initiation appear to be remarkably conserved between
archaea and eucaryotes. For instance, there is homology between archaeal and
eucaryotic basal transcription factors. Also, the archaeal RNA polymerase (RNAP)
resembles eucaryotic nuclear RNAPs in subunit composition and at the amino acid
sequence level. Here, we examine the role of transcription factor B, the archaeal
homologue of eucaryotic transcription factor IIB, in transcription initiation. We
show that the N-terminal region of transcription factor B is required for RNAP
recruitment. Furthermore, we reveal that mutation of a conserved residue
immediately C-terminal of the N-terminal zinc ribbon motif abrogates
transcription on certain promoters. Finally, we identify the promoter sequences
responsive to this mutation and demonstrate that the effect of the mutation is to
block a late stage in transcription initiation, following formation of the
promoter open complex.
PMID- 10777594
TI - Cleavage of the serum response factor during death receptor-induced apoptosis
results in an inhibition of the c-FOS promoter transcriptional activity.
AB - The c-FOS protooncogene is rapidly induced by a wide variety of extracellular
stimuli including mitogenic signals. Regulation of c-FOS expression is tightly
dependent on the serum response element localized within its promoter. Two
transcription factors, the serum response factor (SRF) and the ternary complex
factor, bind to the serum response element and play a key role in the regulation
of the c-FOS promoter activity. In the present study, we show that two death
effectors (CH11 and TRAIL) severely impaired the transcriptional activity of the
c-FOS promoter in Jurkat T cells. This inhibition can be accounted for by the
specific cleavage by caspase 3 of the SRF both in vitro and in vivo, since acetyl
DEVD-aldehyde prevented SRF cleavage and abolished the inhibitory effect of CH11
and TRAIL on the c-FOS promoter activity. Moreover, phorbol myristate acetate, a
potent anti-apoptotic effector, was found to protect SRF completely from cleavage
by caspase 3 and also to prevent the inhibition of the c-FOS promoter activity by
death effectors. Survival factors play an essential function in the regulation of
cell growth mainly by regulating the expression of immediate early gene such as c
FOS. In this line, cleavage of SRF at the onset of apoptosis could abrogate the
ability of the cell to induce inappropriate survival pathways. All together, our
results are consistent with a role of SRF at the interface between cell survival
and death pathways.
PMID- 10777595
TI - Activating transcription factor 2 is necessary for maximal activity and serum
induction of the cyclin A promoter in chondrocytes.
AB - Endochondral bone growth is regulated through the proliferation and
differentiation of growth plate chondrocytes. Mice deficient for the activating
transcription factor 2 (ATF-2) gene show reduced proliferation of chondrocytes.
Here we demonstrate that the cyclin A gene is a target of ATF-2 in chondrocytes.
Serum stimulation of chondrogenic rat chondrosarcoma cells induces cyclin A
expression. A cyclic AMP response element (CRE) is necessary for optimal activity
and serum inducibility of the cyclin A promoter and confers regulation by ATF-2.
Phosphorylation and activity of ATF-2 are enhanced dramatically upon serum
stimulation of rat chondrosarcoma cells. Mutation of the CRE or overexpression of
dominant-negative ATF-2 inhibits serum induction of the cyclin A promoter.
Chondrocytes from ATF-2-deficient mice display reduced and delayed induction of
cyclin A upon serum stimulation. The ATF-2-related transcription factor CRE
binding protein contributes to the activity of the cyclin A CRE in chondrocytes,
whereas c-Jun and c-Fos regulate the promoter independently of the CRE. Our data
suggest that the reduction in cyclin A levels in chondrocytes from ATF-2
deficient mice contributes to their phenotype of reduced chondrocyte
proliferation and dwarfism.
PMID- 10777596
TI - Involvement of mytilins in mussel antimicrobial defense.
AB - Four cationic peptides were purified from mussel (Mytilus galloprovincialis)
hemocytes. A combination of Edman degradation and mass spectrometry of plasma
revealed (i) a previously characterized molecule, mytilin B (Charlet, M.,
Chernysh, S., Philippe, H., Hetrut, C., Hoffmann, J., and Bulet, P. (1996) J.
Biol. Chem. 271, 21808-21813) and (ii) three new isoforms, mytilin C, D, and G1.
The four molecules exhibited complementary antimicrobial properties. The cDNA
sequence coding for the mytilin B precursor was obtained from a hemocyte cDNA
library. This precursor contains a putative signal peptide of 22 residues, a
processing peptide sequence of 34 amino acids, and a C-terminal extension of 48
residues rich in acidic residues. Distribution of mytilin B mRNA and of the
corresponding peptide in various mussel tissues revealed that mytilins are
synthesized and stored in a specific hemocyte subtype. Furthermore, in an
experimental model of infection, we showed (i) a recruitment of hemocytes
containing mytilins toward the injection site within hours following bacterial
challenge, (ii) that mytilins probably play a prominent role in killing
intracellular bacteria after phagocytosis, and (ii) later an increase of mytilin
like material occurred in the plasma suggesting a secondary systemic role.
PMID- 10777597
TI - Structural determinants for post-transcriptional stabilization of lactate
dehydrogenase A mRNA by the protein kinase C signal pathway.
AB - Activation of protein kinase C (PKC) and protein kinase A (PKA) in rat C6 glioma
cells increases the half-life of short-lived lactate dehydrogenase (LDH)-A mRNA
about 5- and 8-fold, respectively. PKA and PKC act synergistically and prolong
LDH-A mRNA half-life more than 21-fold. Similar effects were observed after
transfection and transcription of a globin/lactate dehydrogenase minigene
consisting of a beta-globin expression vector in which the 3'-untranslated region
(UTR) of beta-globin had been replaced with the LDH-A 3'-UTR. Synergism was only
obtained by transcription of minigenes containing the entire 3'-UTR and did not
occur when truncated 3'-UTR fragments were analyzed. Additional mutational
analyses showed that a 20-nucleotide region, named PKC-stabilizing region (PCSR),
is responsible for mediating the stabilizing effect of PKC. Previous studies
(Tian, D., Huang, D., Short, S., Short, M. L., and Jungmann, R. A. (1998) J.
Biol. Chem. 273, 24861-24866) have demonstrated the existence of a cAMP
stabilizing region in LDH-A 3'-UTR. Sequence analysis of PCSR identified a 13
nucleotide AU-rich region that is common to both cAMP-stabilizing region and
PCSR. These studies identify a specific PKC-responsive stabilizing element and
indicate that interaction of PKA and PKC results in a potentiating effect on LDH
A mRNA stabilization.
PMID- 10777598
TI - Integrins regulate the linkage between upstream and downstream events in G
protein-coupled receptor signaling to mitogen-activated protein kinase.
AB - Receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs) can both
activate mitogen-activated protein kinase (MAPK), a critical intermediate in the
transduction of proliferative signals. Numerous observations have demonstrated
that integrin-mediated cell anchorage can regulate the efficiency of signaling
from RTKs to MAPK. Recently, a relationship between integrins and GPCR signaling
has also emerged; however, little is understood concerning the mechanisms
involved. Here, we investigate integrin regulation of GPCR signaling to MAPK,
focusing on the P2Y class of GPCRs that function through activation of
phospholipase Cbeta. P2Y receptor signaling to the downstream components mitogen
activated protein kinase kinase and MAPK is highly dependent on integrin-mediated
cell anchorage. However, activation of upstream events, including inositol
phosphate production and generation of calcium transients, is completely
independent of cell anchorage. This indicates that integrins regulate the linkage
between upstream and downstream events in this GPCR pathway, just as they do in
some aspects of RTK signaling. However, the P2Y pathway does not involve cross
activation of a RTK, nor a role for Shc or c-Raf; thus, it is quite distinct from
the classical RTK-Ras-Raf-MAPK cascade. Rather, integrin-modulated P2Y receptor
stimulation of MAPK depends on calcium and on the activation of protein kinase C.
PMID- 10777599
TI - A novel activation mechanism of caspase-activated DNase from Drosophila
melanogaster.
AB - Caspase-activated DNase (CAD) is an enzyme that cleaves chromosomal DNA in
apoptotic cells. Here, we identified a DNase in Drosophila Schneider cells that
can be activated by caspase 3, and purified it as a complex of two subunits (p32
and p20). Using primers based on the amino acid sequence of the purified
proteins, a cDNA coding for Drosophila CAD (dCAD) was cloned. The polypeptide
encoded by the cDNA contained 450 amino acids with a calculated M(r) of 52,057,
and showed significant homology with human and mouse CAD (22% identity).
Mammalian CADs carry a nuclear localization signal at the C terminus. In
contrast, dCAD lacked the corresponding sequence, and the purified dCAD did not
cause DNA fragmentation in nuclei in a cell-free system. When dCAD was co
expressed in COS cells with Drosophila inhibitor of CAD (dICAD), a 52-kDa dCAD
was produced as a heterotetrameric complex with dICAD. When the complex was
treated with human caspase 3 or Drosophila caspase (drICE), the dICAD was
cleaved, and released from dCAD. In addition, dCAD was also cleaved by these
caspases, and behaved as a (p32)(2)(p20)(2) complex in gel filtration. When a
Drosophila neuronal cell line was induced to apoptosis by treatment with a kinase
inhibitor, both dCAD and dICAD were cleaved. These results indicated that unlike
mammalian CAD, Drosophila CAD must be cleaved by caspases to be activated.
PMID- 10777600
TI - Interleukin-1-mediated stabilization of mouse KC mRNA depends on sequences in
both 5'- and 3'-untranslated regions.
AB - mRNA transcribed from the mouse KC chemokine gene accumulated to significantly
higher levels in multiple cell types after treatment with interleukin 1alpha (IL
1alpha) as compared with tumor necrosis factor-alpha (TNFalpha). Although
TNFalpha and IL-1alpha both signaled the activation of nuclear factor kappaB and
enhanced transcription of the KC gene with equal potency, only IL-1alpha
treatment resulted in stabilization of KC mRNA. Nucleotide sequences that confer
sensitivity for IL-1alpha-mediated mRNA stabilization were identified within the
5'- and 3'-untranslated regions (UTRs) of KC mRNA using transient transfection of
chimeric plasmids containing specific portions of KC mRNA linked to the
chloramphenicol acetyltransferase (CAT) gene. When plasmids containing either the
3'- or 5'-UTR of KC mRNA were used, the half-life of CAT mRNA was unaltered
either in untreated or IL-1alpha-stimulated cells. In contrast, CAT mRNA
transcribed from plasmids that contained both the 5'- and 3'-UTRs of the KC mRNA
decayed more rapidly than control CAT mRNA, and this enhanced decay was prevented
in cells treated with IL-1alpha. A cluster of four overlapping AUUUA motifs
within the 3'-UTR was required, whereas the 5'-UTR region exhibited orientation
dependence. These findings indicate that cooperative function of the two
nucleotide sequences involves a distinct signaling pathway used by IL-1alpha but
not TNFalpha.
PMID- 10777601
TI - The accessibility of histone H3 tails in chromatin modulates their acetylation by
P300/CBP-associated factor.
AB - P300/CBP-associated factor (PCAF) is a transcriptional coactivator with intrinsic
histone acetylase activity. Reversible acetylation of the core histone tails in
chromatin has been linked to transcriptional regulation. Here we investigate the
mechanism whereby PCAF acetylates its target in chromatin. We demonstrate that
recombinant PACF preferentially acetylates the H3 tail in oligonucleosomes, as
compared with nucleosome core particles. The rate of acetylation is directly
related to the length of the oligonucleosomal substrate. Using a trypsin
accessibility assay, we demonstrate that the rate of acetylation is also related
to the accessibility of the H3 tail in uncondensed oligonucleosomes. We suggest
that PCAF, and perhaps other histone acetyltransferases, acetylate chromatin
templates more efficiently than core particle subunits and that this preference
arises from an increased accessibility of the H3 tail in either condensed or
uncondensed oligonucleosomes. Acetylation of the H3 tails by the native PCAF
complex is not affected by the length of the oligonucleosomal substrate. Our
results suggest that the accessibility of the H3 tail in chromatin is a major
factor affecting their rate of acetylation and that component(s) in the native
PCAF complex function to modify the organization of these tails in chromatin
thereby enhancing their accessibility to PCAF.
PMID- 10777602
TI - Structural organization of the microsomal glutathione S-transferase gene (MGST1)
on chromosome 12p13.1-13.2. Identification of the correct promoter region and
demonstration of transcriptional regulation in response to oxidative stress.
AB - The structure and regulation of the microsomal glutathione S-transferase gene
(MGST1) are considerably more complex than originally perceived to be. The MGST1
gene has two alternative first exons and is located in the 12p13.1-13.2 region.
Two other potential first exons were determined to be nonfunctional. The region
between the functional first exons cannot direct transcription. Thus, one common
promoter element directing transcription exists, and RNA splicing occurs such
that only one of the first exons (containing only untranslated mRNA) is
incorporated into each mRNA species with common downstream exons. MGST1
expression and regulation are therefore similar to those of other hepatic
xenobiotic handling enzymes, which also produce mRNA species differing only in
the 5'-untranslated regions to yield identical proteins. MGST1 was previously
considered a "housekeeping" gene, as non-oxidant inducers had little effect on
activity. However, the promoter region immediately upstream of the dominant first
exon transcriptionally responds to oxidative stress. In this respect, MGST1 is
similar to glutathione peroxidases that also transcriptionally respond to
oxidative stress. The discovery that MGST1 utilizes alternative first exon
splicing eliminates a problem with the first description of MGST1 cDNA in that it
appeared that MGST1 expression was in violation of the ribosomal scanning model.
The identification that the first exon originally noted is in fact a minor
alternative first exon far downstream of the primary first exon eliminates this
conundrum.
PMID- 10777603
TI - Steady-state levels of histone acetylation in Saccharomyces cerevisiae.
AB - The importance of control of the levels of histone acetylation for the control of
gene expression in eukaryotic chromatin is being elucidated, and the yeast
Saccharomyces cerevisiae has proven to be an important model system. The level of
histone acetylation in yeast is the highest known. However, only acetylation of
H4 has been quantified, and reports reveal loss of acetylation in histone
preparations. A chaotropic guanidine-based method for histone isolation from
intact wild-type cells or from a single-step nuclear preparation with butyrate
preserves acetylation of all core histones. Histone H4 has an average of more
than 2 acetylated lysines per molecule, distributed over 4 sites. Histones H2A,
H3, and H2B have 0. 2, approximately 2, and >2 acetylated lysines per molecule,
respectively, distributed across 2, 5, and 6 sites. Thus, yeast nucleosomes
carry, on average, 13 acetylated lysines per octamer, i. e. just above the
threshold of 10-12 deduced for transcriptionally activated chromatin of animals,
plants, and algae. Following M(r) 100,000 ultrafiltration in 2.5% acetic acid,
yeast histone H3 was purified to homogeneity by reversed-phase high pressure
liquid chromatography. Other core histones were obtained at 80-95% purity.
PMID- 10777604
TI - Human cytosolic and mitochondrial folylpolyglutamate synthetase are
electrophoretically distinct. Expression in antifolate-sensitive and -resistant
human cell lines.
AB - Folylpolyglutamate synthetase (FPGS) activity in CCRF-CEM human leukemia cells
was found in the cytosolic ( approximately 67% of total) and mitochondrial (
approximately 22%) fractions. A polyclonal antipeptide antibody (430Ab) to human
FPGS specifically recognized distinct immunoreactive bands ( approximately 60
kDa) present in each subcellular fraction. Human cytosolic FPGS (hcFPGS) migrated
more rapidly than mitochondrial FPGS (hmFPGS); their estimated difference in
molecular mass was 1 kDa. The human K562 acute nonlymphocytic leukemia and the
A253 and FaDu head and neck cancer cell lines also expressed the two FPGS
isoforms, and the ratio of hcFPGS to hmFPGS protein in each cell line was
similar. Since K562 and A253 cells are intrinsically resistant to pulse
methotrexate (MTX) exposure relative to CCRF-CEM and FaDu cells, respectively,
because of decreased MTX polyglutamate synthesis (despite having similar levels
of total FPGS activity expression), these data suggest that the natural
difference in drug sensitivity cannot be explained by compartmentalization of
FPGS activity. Higher expression of hmFPGS relative to hcFPGS was observed in
some sublines of CCRF-CEM with acquired MTX resistance suggesting that
differential expression of the hmFPGS isoform may contribute to MTX resistance
caused by decreased FPGS activity.
PMID- 10777605
TI - The efficiency and fidelity of translesion synthesis past cisplatin and
oxaliplatin GpG adducts by human DNA polymerase beta.
AB - DNA polymerase beta (pol beta) is the only mammalian DNA polymerase identified to
date that can catalyze extensive bypass of platinum-DNA adducts in vitro.
Previous studies suggest that DNA synthesis by pol beta is distributive on primed
single-stranded DNA and processive on gapped DNA. The data presented in this
paper provide an analysis of translesion synthesis past cisplatin- and
oxaliplatin-DNA adducts by pol beta functioning in both distributive and
processive modes using primer extension and steady-state kinetic experiments.
Translesion synthesis past Pt-DNA adducts was greater with gapped DNA templates
than with single-stranded DNA templates. In the processive mode pol beta did not
discriminate between cisplatin and oxaliplatin adducts, while in the distributive
mode it displayed about 2-fold increased ability for translesion synthesis past
oxaliplatin compared with cisplatin adducts. The differentiation between
cisplatin and oxaliplatin adducts resulted from a K(m)-mediated increase in the
efficiency of dCTP incorporation across from the 3'-G of oxaliplatin-GG adducts.
Rates of misincorporation across platinated guanines determined by the steady
state kinetic assay were higher in reactions with primed single-stranded
templates than with gapped DNA and a slight increase in the misincorporation of
dTTP across from the 3'-G was found for oxaliplatin compared with cisplatin
adducts.
PMID- 10777606
TI - Cyclic nucleotides suppress tumor necrosis factor alpha-mediated apoptosis by
inhibiting caspase activation and cytochrome c release in primary hepatocytes via
a mechanism independent of Akt activation.
AB - Cyclic nucleotides have been previously shown to modulate cell death processes in
many cell types; however, the mechanisms by which cyclic nucleotides regulate
apoptosis are unclear. In this study, we demonstrated that cAMP as well as cGMP
analogs suppressed tumor necrosis factor alpha (TNFalpha) plus actinomycin D
(ActD)-induced apoptosis in a dose-dependent manner in cultured primary
hepatocytes. Furthermore, forskolin, which increases intracellular cAMP levels,
also effectively suppressed TNFalpha+ActD-induced apoptosis. Activation of
multiple caspases was suppressed in cells exposed to TNFalpha+ActD in the
presence of cAMP or cGMP analogs. TNFalpha+ActD-induced cytochrome c release from
mitochondria was also inhibited by cAMP or cGMP, reinforcing our conclusion that
cyclic nucleotides interfere with the early signaling events of TNFalpha-mediated
apoptosis. We evaluated the possibility that cAMP and cGMP inhibit apoptosis by
activating the serine/threonine kinase Akt, which is known to promote cell
survival. Both cAMP- and cGMP-elevating agents led to marked increases in Akt
activation that was inhibited by the phosphatidylinositol 3'-kinase inhibitors,
LY294002 and wortmannin. However, complete inhibition of cyclic nucleotide
induced Akt activation had little effect on cyclic nucleotide-mediated cell
survival, indicating the existence of other survival pathways. Interestingly, the
specific inhibitor of protein kinase A (PKA), KT5720, blocked cGMP-mediated
protection but only partially prevented the anti-apoptotic effect of cAMP,
indicating that both PKA-dependent and -independent mechanisms are involved in
cAMP-mediated suppression of apoptosis signaling. Our data suggest that multiple
survival signaling pathways coexist in cells and that cyclic nucleotides delay
apoptosis by interfering with apoptosis signaling by both PKA-dependent and
independent mechanisms.
PMID- 10777607
TI - Ouabain-sensitive H,K-ATPase functions as Na,K-ATPase in apical membranes of rat
distal colon.
AB - Na,K-ATPase activity has been identified in the apical membrane of rat distal
colon, whereas ouabain-sensitive and ouabain-insensitive H,K-ATPase activities
are localized solely to apical membranes. This study was designed to determine
whether apical membrane Na,K-ATPase represented contamination of basolateral
membranes or an alternate mode of H,K-ATPase expression. An antibody directed
against the H, K-ATPase alpha subunit (HKcalpha) inhibited apical Na,K-ATPase
activity by 92% but did not alter basolateral membrane Na,K-ATPase activity. Two
distinct H,K-ATPase isoforms exist; one of which, the ouabain-insensitive
HKcalpha, has been cloned. Because dietary sodium depletion markedly increases
ouabain-insensitive active potassium absorption and HKcalpha mRNA and protein
expression, Na, K-ATPase and H,K-ATPase activities and protein expression were
determined in apical membranes from control and sodium-depleted rats. Sodium
depletion substantially increased ouabain-insensitive H, K-ATPase activity and
HKcalpha protein expression by 109-250% but increased ouabain-sensitive Na,K
ATPase and H,K-ATPase activities by only 30% and 42%, respectively. These studies
suggest that apical membrane Na,K-ATPase activity is an alternate mode of ouabain
sensitive H,K-ATPase and does not solely represent basolateral membrane
contamination.
PMID- 10777608
TI - Communication between the ATPase and cleavage/religation domains of human
topoisomerase IIalpha.
AB - The DNA strand passage activity of eukaryotic topoisomerase II relies on a
cascade of conformational changes triggered by ATP binding to the N-terminal
domain of the enzyme. To investigate the interdomain communication between the
ATPase and cleavage/religation domains of human topoisomerase IIalpha, we
characterized a mutant enzyme that contains a deletion at the interface between
the two domains, covering amino acids 350-407. The ATPase domain retained full
activity with a rate of ATP hydrolysis that was severalfold higher than normal,
but the ATPase activity was unaffected by DNA. The cleavage and religation
activities of the enzyme were comparable with those of the wild-type enzyme both
in the absence and presence of cancer chemotherapeutic agents. However, neither
ATP nor a nonhydrolyzable ATP analog stimulated cleavage complex formation.
Although both conserved domains retained full activity, the mutant enzyme was
unable to coordinate these activities into strand passage. Our findings suggest
that the normal conformational transitions occurring in the enzyme upon ATP
binding are hampered or lacking in the mutant enzyme. Consistent with this
hypothesis, the enzyme displayed an abnormal clamp closing activity. In summary,
the region covering amino acids 350-407 in human topoisomerase IIalpha seems to
be essential for correct interdomain communication and probably is involved in
signaling ATP binding to the rest of the enzyme.
PMID- 10777609
TI - Molecular basis of vitamin E action. Tocotrienol potently inhibits glutamate
induced pp60(c-Src) kinase activation and death of HT4 neuronal cells.
AB - HT4 hippocampal neuronal cells were studied to compare the efficacy of
tocopherols and tocotrienol to protect against glutamate-induced death.
Tocotrienols were more effective than alpha-tocopherol in preventing glutamate
induced death. Uptake of tocotrienols from the culture medium was more efficient
compared with that of alpha-tocopherol. Vitamin E molecules have potent
antioxidant properties. Results show that at low concentrations, tocotrienols may
have protected cells by an antioxidant-independent mechanism. Examination of
signal transduction pathways revealed that protein tyrosine phosphorylation
processes played a central role in the execution of death. Activation of pp60(c
Src) kinase and phosphorylation of ERK were observed in response to glutamate
treatment. Nanomolar amounts of alpha-tocotrienol, but not alpha-tocopherol,
blocked glutamate-induced death by suppressing glutamate-induced early activation
of c-Src kinase. Overexpression of kinase-active c-Src sensitized cells to
glutamate-induced death. Tocotrienol treatment prevented death of Src
overexpressing cells treated with glutamate. alpha-Tocotrienol did not influence
activity of recombinant c-Src kinase suggesting that its mechanism of action may
include regulation of SH domains. This study provides first evidence describing
the molecular basis of tocotrienol action. At a concentration 4-10-fold lower
than levels detected in plasma of supplemented humans, tocotrienol regulated
unique signal transduction processes that were not sensitive to comparable
concentrations of tocopherol.
PMID- 10777610
TI - PDZ domain-dependent suppression of NF-kappaB/p65-induced Abeta42 production by a
neuron-specific X11-like protein.
AB - It is widely believed that one of the causes of Alzheimer's disease (AD) is the
generation and secretion of beta-amyloid (Abeta) from amyloid precursor protein
in the brain. Here we report that a transcription factor, NF-kappaB/p65, induces
increased secretion of amyloidogenic Abeta42 but not Abeta40. The kappaB motif
dependent production of Abeta42 was suppressed by binding of NF-kappaB/p65 to the
PDZ domain of the X11-like protein (X11L), which a human homologue protein of LIN
10. The results suggest that the PDZ domain of X11L can control the ability of NF
kappaB/p65 to induce expression of protein(s) involved in Abeta42 production. The
amino acids 161-163 in Rel homology domain (RHD) of NF-kappaB/p65 is important in
interaction of NF-kappaB/p65 with X11L. Another subunit NF-kappaB/p50 and
heterodimers of p65 and p50 do not bind to X11L. Our finding indicates NF-kappaB
and X11L may, in novel way, regulate Abeta production in neuronal cells.
Targeting X11L by specific therapy may provide the possibility to control the
progression of AD.
PMID- 10777611
TI - RNA degradation and primer selection by Moloney murine leukemia virus reverse
transcriptase contribute to the accuracy of plus strand initiation.
AB - During reverse transcription, plus strand DNA synthesis is initiated at a purine
rich RNA primer generated by the RNase H activity of reverse transcriptase (RT).
Specific initiation of plus strand synthesis from this polypurine tract (PPT) RNA
is essential for the subsequent integration of the linear viral DNA product.
Based on current models, it is predicted that priming from sites upstream of the
PPT may be tolerated by the virus, whereas efficient extension from RNA primers
located downstream from the PPT is predicted to generate dead-end products. By
using hybrid duplex substrates derived from the Moloney murine leukemia virus
long terminal repeat, we investigated the extent to which RNase H degrades the
viral RNA during time course cleavage assays, and we tested the capacity of the
polymerase activity of RT to use the resulting cleavage products as primers. We
find that the majority of the RNA fragments generated by RNase H are 2-25
nucleotides in length, and only following extensive degradation are most
fragments reduced to 10 nucleotides or smaller. Although extensive RNA
degradation by RNase H likely eliminates many potential RNA primers, based on
thermostability predictions it appears that some RNA fragments remain stably
annealed to the DNA template. RNA primers generated by RNase H within the long
terminal repeat sequence are found to have the capacity to initiate DNA synthesis
by RT; however, the priming efficiency is significantly less than that observed
with the PPT primer. We find that Moloney murine leukemia virus nucleocapsid
protein reduces RNase H degradation and slightly alters the cleavage specificity
of RT; however, nucleocapsid protein does not appear to enhance PPT primer
utilization or suppress extension from non-PPT RNA primers.
PMID- 10777612
TI - Structural and functional characterization of platelet receptor-mediated factor
VIII binding.
AB - Optimal rates of factor X (FX) activation require occupancy of receptors for
factor IXa (FIXa), factor VIII (FVIII), and FX on the activated platelet surface.
The presence of FVIII and FX increases 5-fold the affinity of FIXa for the
surface of activated platelets, and the presence of FVIII or FVIIIa generates a
high affinity, low capacity specific FX-binding site on activated platelets. We
have now examined the effects of FX and active site-inhibited FIXa (EGR-FIXa) on
the binding of both FVIII and FVIIIa to activated platelets and show the
following: (a) von Willebrand factor inhibits FVIII binding (K(i) = 0.54 nM) but
not FVIIIa binding; (b) thrombin and the thrombin receptor activation peptide
(SFLLRN amide) are the most potent agonists required for FVIII-binding site
expression, whereas ADP is inert; (c) FVa does not compete with FVIIIa or FVIII
for functional platelet-binding sites; and (d) Annexin V is a potent inhibitor of
FVIIIa binding (IC(50) = 10 nM) to activated platelets. The A2 domain of FVIII
significantly increases the affinity and stoichiometry of FVIIIa binding to
platelets and contributes to the stability of the FX-activating complex. Both
FVIII and FVIIIa binding were specific, saturable, and reversible. FVIII binds to
specific, high affinity receptors on activated platelets (n = 484 +/- 59; K(d) =
3.7 +/- 0.31 nM) and FVIIIa interacts with an additional 300-500 sites per
platelet with enhanced affinity (K(d) = 1.5 +/- 0.11 nM). FVIIIa binding to
activated platelets in the presence of FIXa and FX is closely coupled with rates
of F-X activation. The presence of EGR-FIXa and FX increases both the number and
the affinity of binding sites on activated platelets for both FVIII and FVIIIa,
emphasizing the validity of a three-receptor model in the assembly of the F-X
activating complex on the platelet surface.
PMID- 10777613
TI - An NF-Y binding site is important for basal, but not gonadotropin-releasing
hormone-stimulated, expression of the luteinizing hormone beta subunit gene.
AB - Regulated synthesis of luteinizing hormone (LH) requires coordinated
transcriptional control of the alpha and LHbeta subunits in pituitary
gonadotropes. Several cis-acting elements and trans-acting factors have been
defined for control of the LHbeta promoter through heterologous cell culture
models. In this report, we describe the identification of bipartite NF-Y
(CBF/CP1) binding sites within the proximal bovine LHbeta promoter. When
multimerized, one of these sites activates the heterologous, minimal HSV
thymidine kinase promoter in the gonadotrope-derived cell line alphaT3-1. The
functional role of the promoter-distal site in regulating the full-length bovine
LHbeta promoter was assessed in vivo using transgenic mice harboring a mutant
promoter linked to the chloramphenicol acetyltransferase reporter gene. While
this element is important for conferring high level activity of the LHbeta
promoter in pituitary, it does not appear to be essential for mediating
gonadotropin-releasing hormone (GnRH) regulation. This is the first
characterization of a cis-acting element within this GnRH-dependent promoter that
is restricted to regulating basal expression and not GnRH-induced activity.
PMID- 10777614
TI - Functional relationship between calreticulin, calnexin, and the endoplasmic
reticulum luminal domain of calnexin.
AB - Calnexin is a membrane protein of the endoplasmic reticulum (ER) that functions
as a molecular chaperone and as a component of the ER quality control machinery.
Calreticulin, a soluble analog of calnexin, is thought to possess similar
functions, but these have not been directly demonstrated in vivo. Both proteins
contain a lectin site that directs their association with newly synthesized
glycoproteins. Although many glycoproteins bind to both calnexin and
calreticulin, there are differences in the spectrum of glycoproteins that each
binds. Using a Drosophila expression system and the mouse class I
histocompatibility molecule as a model glycoprotein, we found that calreticulin
does possess apparent chaperone and quality control functions, enhancing class I
folding and subunit assembly, stabilizing subunits, and impeding export of
assembly intermediates from the ER. Indeed, the functions of calnexin and
calreticulin were largely interchangeable. We also determined that a soluble form
of calnexin (residues 1-387) can functionally replace its membrane-bound
counterpart. However, when calnexin was expressed as a soluble protein in L
cells, the pattern of associated glycoproteins changed to resemble that of
calreticulin. Conversely, membrane-anchored calreticulin bound to a similar set
of glycoproteins as calnexin. Therefore, the different topological environments
of calnexin and calreticulin are important in determining their distinct
substrate specificities.
PMID- 10777615
TI - Comparison of the functional characteristics of the nucleotide binding domains of
multidrug resistance protein 1.
AB - Multidrug Resistance Protein 1 (MRP1) transports diverse organic anionic
conjugates and confers resistance to cytotoxic xenobiotics. The protein contains
two nucleotide binding domains (NBDs) with features characteristic of members of
the ATP-binding cassette superfamily and exhibits basal ATPase activity that can
be stimulated by certain substrates. It is not known whether the two NBDs of MRP1
are functionally equivalent. To investigate this question, we have used a
baculovirus dual expression vector encoding both halves of MRP1 to reconstitute
an active transporter and have compared the ability of each NBD to be
photoaffinity-labeled with 8-azido-[(32)P]ATP and to trap 8-azido-[(32)P]ADP in
the presence of orthovanadate. We found that NBD1 was preferentially labeled with
8-azido-[(32)P]ATP, while trapping of 8-azido-[(32)P]ADP occurred predominantly
at NBD2. Although trapping at NBD2 was dependent on co-expression of both halves
of MRP1, binding of 8-azido-ATP by NBD1 remained detectable when the NH(2)
proximal half of MRP1 was expressed alone and when NBD1 was expressed as a
soluble polypeptide. Mutation of the conserved Walker A lysine 684 or creation of
an insertion mutation between Walker A and B motifs eliminated binding by NBD1
and all detectable trapping of 8-azido-ADP at NBD2. Both mutations decreased
leukotriene C(4) (LTC(4)) transport by approximately 70%. Mutation of the NBD2
Walker A lysine 1333 eliminated trapping of 8-azido-ADP by NBD2 but, in contrast
to the mutations in NBD1, essentially eliminated LTC(4) transport activity
without affecting labeling of NBD1 with 8-azido-[(32)P]ATP.
PMID- 10777616
TI - Degradation of DNA topoisomerase I by a novel trypsin-like serine protease in
proliferating human T lymphocytes.
AB - DNA topoisomerase I (Topo I) contributes to various important biological
functions, and its activity is therefore likely regulated in response to
different physiological conditions. Increases in both the synthesis and
degradation of Topo I were previously shown to accompany phytohemagglutinin
stimulation of proliferation in human peripheral T lymphocytes. The mechanism of
this degradation of Topo I has now been investigated with both in vivo and in
vitro assays. The activity of a nuclear protease that specifically degrades Topo
I was induced in proliferating T lymphocytes. The full-length Topo I protein (100
kDa) was sequentially degraded to 97- and 82-kDa fragments both in vivo and in
vitro. The initial site of proteolytic cleavage was mapped to the NH(2)-terminal
region of the enzyme. The degradation of Topo I in vitro was inhibited by
aprotinin or soybean trypsin inhibitor, suggesting that the enzyme responsible is
a trypsin-like serine protease. Furthermore, Topo I degradation by this protease
was Mg(2+)-dependent. The Topo I-specific protease activity induced during T
lymphocytes proliferation was not detected in Jurkat (human T cell leukemia)
cells and various other tested human cancer cell lines, possibly explaining why
the abundance of Topo I is increased in tumor cells.
PMID- 10777617
TI - The association of CRKII with C3G can be regulated by integrins and defines a
novel means to regulate the mitogen-activated protein kinases.
AB - In studies to define mechanisms of ERK activation in Chinese hamster ovary cells,
we have observed an inverse correlation between CRKII-C3G complex formation and
ERK activity. That is, we were able to coprecipitate the guanine nucleotide
exchange factor C3G with the adaptor protein CRKII in lysates from suspended
cells that had low ERK activity, but we could not do so or could do so less
efficiently in lysates of adherent cells with increased ERK activity. Consistent
with the presence of a functional CRKII-C3G complex, we detected more GTP-loaded
RAP1 in suspension than adherent lysates. Overexpression of cDNAs encoding B-RAF,
CRKII W109L, and PTP1B C215S activated ERK in suspension cells, the latter two
constructs also disrupting CRKII-C3G complex formation. Finally, we have also
observed that certain integrin alpha subunit cytoplasmic splice variants
differentially regulate ERK1/2 but also in a manner that correlated with levels
of a CRKII-C3G complex. Thus, these data suggest the involvement of integrins in
an ERK suppression pathway mediated by CRKII-C3G complex formation and downstream
signaling from activated RAP1.
PMID- 10777618
TI - SH2-B is required for growth hormone-induced actin reorganization.
AB - The Src homology-2 (SH2) domain-containing protein SH2-Bbeta is a substrate of
the growth hormone (GH) receptor-associated tyrosine kinase JAK2. Here we tested
whether SH2-Bbeta is involved in GH regulation of the actin cytoskeleton. Based
on cell fractionation and confocal microscopy, we find SH2-Bbeta present at the
plasma membrane and in the cytosol. SH2-Bbeta colocalized with filamentous actin
in GH and platelet-derived growth factor (PDGF)-induced membrane ruffles. To test
if SH2-Bbeta is required for actin reorganization, we transiently overexpressed
wild-type or mutant SH2-Bbeta in 3T3-F442A cells and assayed for GH- and PDGF
induced membrane ruffling and fluid phase pinocytosis. Overexpression of wild
type SH2-Bbeta enhanced ruffling and pinocytosis produced by submaximal GH but
not submaximal PDGF. Point mutant SH2-Bbeta (R555E) and truncation mutant
DeltaC555, both lacking a functional SH2 domain, inhibited membrane ruffling and
pinocytosis induced by GH and PDGF. Mutant DeltaN504, which possesses a
functional SH2 domain and enhances JAK2 kinase activity in overexpression
systems, also inhibited GH-stimulated membrane ruffling. DeltaN504 failed to
inhibit GH-induced nuclear localization of Stat5B, indicating JAK2 is active in
these cells. Taken together, these results show that SH2-Bbeta is required for GH
induced actin reorganization by a mechanism discrete from the action of SH2-Bbeta
as a stimulator of JAK2 kinase activity.
PMID- 10777619
TI - Sequential serum-dependent activation of CREB and NRF-1 leads to enhanced
mitochondrial respiration through the induction of cytochrome c.
AB - Progression through the cell cycle requires ATP for protein synthesis,
cytoskeletal rearrangement, chromatin remodeling, and protein degradation. The
mechanisms by which mammalian cells increase respiratory capacity and ATP
production in preparation for cell division are largely unexplored. Here, we
demonstrate that serum induction of cytochrome c mRNA and processed protein in
quiescent BALB/3T3 fibroblasts is associated with a marked increase in
mitochondrial respiration. Cytochrome c was induced in the absence of any
increase in citrate synthase activity or in subunit IV of the cytochrome c
oxidase complex mRNA or protein, indicating that the enhanced respiratory rate
did not require a general increase in mitochondrial biogenesis or respiratory
chain expression. Transfections with a series of cytochrome c promoter mutants
showed that both nuclear respiratory factor 1 (NRF-1) and cAMP-response element
binding protein (CREB) binding sites contributed equally to induced expression by
serum. Moreover, CREB and NRF-1 were phosphorylated sequentially in response to
serum, and the NRF-1 phosphorylation was accompanied by an increase in its
ability to trans-activate target gene expression. The results demonstrate that
the differential transcriptional expression of cytochrome c, through sequential
transcription factor phosphorylations, leads to enhanced mitochondrial
respiratory capacity upon serum-induced entry to the cell cycle.
PMID- 10777620
TI - Role of phosphatidylinositol 3-kinase and specific protein kinase B isoforms in
the suppression of apoptosis mediated by the Abelson protein-tyrosine kinase.
AB - Leukemogenic oncogenes, such as the Abelson protein-tyrosine kinases (PTK),
disrupt the normal regulation of survival, proliferation, and differentiation in
hemopoietic progenitor cells. In the absence of cytokines, hemopoietic progenitor
cells die by apoptosis. Abl PTKs mediate suppression of this apoptotic response
leading to aberrant survival. To investigate the mechanism of Abl PTK action, we
have used an interleukin-3-dependent murine mast cell line that expresses a
temperature-sensitive form of the v-ABL PTK, which is active at the permissive
temperature of 32 degrees C and inactive at 39 degrees C. At the permissive
temperature, these cells are resistant to apoptosis induced both by the
withdrawal of the hemopoietic growth factor (interleukin-3) and the addition of
cytotoxic drugs. We demonstrate that v-Abl associates with and stimulates
activation of phosphatidylinositol 3-kinase (PI3K) and, crucially, that this
activation results in enhanced cellular levels of the mass of the second
messenger phosphatidylinositol-3,4,5-trisphosphate. Activation of PI3K leads to
enhanced activity of PKB and increased levels of the anti-apoptotic protein Bcl
X(L). Transfection of cells with a dominant negative PKB reduces both the Abl
stimulated PKB activity and the survival effect conferred by activation of this
oncogene. Thus, PI3K and PKB are required for the anti-apoptotic effects of Abl
PTK.
PMID- 10777621
TI - FKBP12 is a negative regulator of transforming growth factor-beta receptor
internalization.
AB - Transforming growth factor-beta (TGF-beta) family polypeptides regulate cell
growth and differentiation by binding to single pass serine/threonine kinases
referred to as TGF-beta type I and II receptors. Although interaction screens
have shown that the immunophilin FKBP12 interacts with TGF-beta type I receptors,
the role of FKBP12 in TGF-beta receptor action is presently unclear. Using a
chimeric TGF-beta receptor system, we have shown a specific enhancement of
internalization when FKBP12 binding to the type I receptor was prevented with
rapamycin. Moreover, although earlier studies demonstrated that type II receptor
kinase activity was required for optimal internalization in mesenchymal cells, we
found that rapamycin functioned downstream of the type II receptor kinase. Thus,
rather than modulating TGF-beta signaling, our data suggest a novel role for
FKBP12 as a negative regulator of TGF-beta receptor endocytosis.
PMID- 10777622
TI - Characterization of the roles of the 594-645 region in human endothelial nitric
oxide synthase in regulating calmodulin binding and electron transfer.
AB - It has been postulated that a segment (residues 594-645) inserted in the FMN
subdomain of human endothelial nitric-oxide synthase (eNOS) plays a crucial role
in controlling Ca(2+)-dependent CaM binding for eNOS activity. To investigate its
functions, we expressed human eNOS in a baculovirus system with deletion of a 45
residue segment from this region (residues 594-606 and 614-645, designated as
Delta45eNOS), and characterized the purified mutant enzyme. In contrast with wild
type eNOS, Delta45eNOS exhibited characteristics resembling inducible NOS (iNOS).
It contained an endogenously bound CaM, which was essential in folding and
stabilizing this mutant enzyme, and retained 60% of L-citrulline formation in 5
mM EGTA. We also produced four N-terminally truncated reductase domains with or
without the 45-residue segment, and either including or excluding the CaM-binding
sequence. Basal cytochrome c reductase activity of reductase domains without the
45-residue segment was up to 20 fold greater than that of corresponding insert
containing domains, and higher than CaM-stimulated activity of the wild-type
enzyme. A series of mutants with smaller fragment deletion in this region such as
Delta594-604, Delta605-612, Delta613-625, Delta626-634, Delta632-639, and
Delta640-645 mutants were further characterized. The crude lysate of mutants
Delta613-625 and Delta632-639 did not show activity in the presence of
Ca(2+)/CaM, while other four mutants had activity comparable to that of WTeNOS.
The purified Delta594-604 and Delta605-612 proteins had a 3-5-fold higher
affinity for Ca(2+)/CaM, but their L-citrulline forming activity was still 80%
dependent upon the addition of Ca(2+)/CaM. Both mutants exhibited a low level of
the cytochrome c and ferricyanide reductase activities, which either did not
respond to (Delta594-604) or slightly enhanced by (Delta605-612) the exogenous
CaM. In contrast, activities of Delta626-634 and Delta640-645 like those of
WTeNOS were largely Ca(2+)/CaM-dependent. Thus, our findings indicate that the N
terminal half of the 594-645 segment containing residues 594-612 plays a
significant role in regulating Ca(2+)/CaM binding.
PMID- 10777624
TI - The Catalytic Asymmetric Aldol Reaction.
AB - The construction of C-C bonds with complete control of the stereochemical course
of a reaction is of utmost importance for organic synthesis. The aldol reaction
the simple addition of an enolate donor to a carbonyl acceptor-is one of the most
powerful reactions available to the synthetic chemist. In general, control of the
relative and absolute configuration of the newly formed stereogenic centers has
been achieved through the use of chiral starting materials or chiral auxiliaries.
In recent years the search for catalytic methods that efficiently and effectively
transfer chirality information has become a major effort in synthetic organic
chemistry. Two different approaches have been taken toward the catalytic
asymmetric aldol reaction: biocatalysis and catalysis with small molecules. Both
approaches have specific advantages and limitations, and as a result are
complementary to each other. The important efforts toward both approaches are
reviewed in this article.
PMID- 10777625
TI - Ceramics and Nanostructures from Molecular Precursors.
AB - The elaboration of solids from the molecular scale by a kinetically controlled
methodology is one of the main challenges of molecular chemistry. In the long
term, this should permit the design of solids with desired properties. Here, some
examples are given which show a few methods that have been used for the
preparation of solids from molecular precursors. The one-pot synthesis of
rheologically controlled SiC is described. Access to a new kind of ceramic is
obtained by the same methodology using molecular precursors. Mixed ceramics with
interpenetrating networks are not accessible by the chemical thermodynamic route.
The chemistry of hybrid materials obtained from molecular precursors through
inorganic polymerization is presented. This class of materials offers wide
perspectives because of 1) the large possibilities opened by the organic unit, 2)
the kinetic control, which permits any kind of texture for the solid, and 3) the
aptitude of these solids to become nanostructured.
PMID- 10777626
TI - Chemistry and Biology of Plant Leaf Movements.
AB - The leaves of Mimosa pudica L. are well known for their rapid movement when
touched. Recently, we were able to isolate an excitatory substance in small
quantities from this plant, which consists of three different components
(potassium L-malate, magnesium trans-aconitate, and dimethylammonium salt). Many
plants close their leaves in the evening, as if to sleep, and open them early in
the morning (nyctinastic leaf movement). This circadian rhythm is known to be
controlled by the biological clock of such plants. Extensive studies on other
nyctinastic plants led to the isolation of a variety of leaf-opening substances
(LOSs) and leaf-closing substances (LCSs). Based on our experiments on these
bioactive substances, we found that the circadian rhythmic leaf movement of these
plants is initiated by the regulated balance of LOSs and LCSs. The balance of
concentration between the two leaf-movement factors (LMFs) is inversed during the
day. The glycoside-type LMF is hydrolyzed with beta-glucosidase, the activity of
which is regulated by the biological clock. The circadian rhythm observed in the
leaf movement is introduced by activation of beta-glucosidase regulated by the
biological clock.
PMID- 10777627
TI - Syntheses of CP-225,917 and CP-263,114.
PMID- 10777628
TI - In Spite of the Chemist's Belief: Carbonic Acid Is Surprisingly Stable.
PMID- 10777629
TI - [{Cp]
PMID- 10777630
TI - Asymmetric Catalysis with Chiral Phosphane/Phosphoramidite Ligands Derived from
Quinoline (QUINAPHOS) This work was supported by the Max Planck Society, MURST
(Rome), and the University of Messina (exchange fellowship for G.F.). We thank
Dr. C. Arena (University of Messina), Prof. G. Hanan (University of Waterloo),
and Dr. C. W. Lehmann (MPI Mulheim) for fruitful discussions.
PMID- 10777631
TI - Stereoselective Combinatorial Ugi-Multicomponent Synthesis on Solid Phase This
work was supported by the Deutsche Forschungsgemeinschaft and by the Fonds der
Chemischen Industrie.
PMID- 10777632
TI - Ring-Opening Metathesis Polymerization: Access to a New Class of Functionalized,
Monolithic Stationary Phases for Liquid Chromatography.
PMID- 10777633
TI - Optimized Two-Dimensional NLO Chromophores with a Threefold Symmetry Axis The
authors would like to thank the Volkswagenstiftung and the Fonds der Chemischen
Industrie for generous financial supports of this work.
PMID- 10777634
TI - Synthesis of the First Selective Irreversible Inhibitor of Neutral
Sphingomyelinase This work was supported by grants from the Fonds der Chemischen
Industrie. C.A. is grateful to the Land of Baden-Wurttemberg for a scholarship
from the Landesgraduiertenforderung.
PMID- 10777635
TI - Structural Characterization of a Plutonium(IV) Siderophore Complex: Single
Crystal Structure of Pu-Desferrioxamine E Support for this work is provided by
the U.S. Department of Energy (Natural and Accelerated Bioremediation Research
(NABIR) Program). We thank Professor G. Winkelmann, Universitat Tubingen, for
generously providing a sample of desferrioxamine E.
PMID- 10777636
TI - Towards Detection of a Long-lived Protonated Metal Cation: Generation of GeH(2+)
Using High-Energy Collisions This research was supported by the Deutsche
Forschungsgemeinschaft, the Volkswagen-Stiftung, and the Fonds der Chemischen
Industrie. The Konrad-Zuse-Zentrum, Berlin, is acknowledged for generous
allocation of computer time. R.S. is grateful to the Deutscher Akademischer
Austauschdienst (DAAD) for financial support, and thanks Dr. K. V. Raghavan,
Director of the Indian Institute of Chemical Technology, for his encouragement
and assistance.
PMID- 10777637
TI - The structure of IF(3) This work was supported by the Deutsche
Forschungsgemeinschaft and the Fonds der Chemischen Industrie.
PMID- 10777638
TI - Synthesis of the N-Terminal N-Myristoylated and S-Palmitoylated
Undetrigintapeptide of Endothelial NO-Synthase This research was supported by the
Fonds der Chemischen Industrie and the Deutsche Forschungsgemeinschaft.
PMID- 10777639
TI - 4-(N-Methylhydrazino)-7-nitro-2,1,3-benzooxadiazole (MNBDH): A Novel Fluorogenic
Peroxidase Substrate The authors would like to thank the Fonds der Chemischen
Industrie (Frankfurt/Main) for financial support.
PMID- 10777640
TI - sigma-Homoconjugation in Cyclically Preoriented N4-(Radical) Cations-N small
middle dot small middle dot small middle dotN Bond Lengths >2 A This project has
been supported by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen
Industrie and BASF AG. We thank Dipl.-Chem. V. Peron and B. Geiser for technical
assistance.
PMID- 10777641
TI - Extremely Long, Discrete meso - meso-Coupled Porphyrin Arrays This work was
supported by Grant-in-Aids for Scientific Research (No. 11136221 and 11223205)
from the Ministry of Education, Science, Sports, and Culture of Japan and by
CREST (Core Research for Evolutional Science and Technology) from the Japan
Science and Technology Corporation (JST). The work at KRISS was supported by the
National Creative Research Initiatives of the Ministry of Science and Technology
of Korea.
PMID- 10777642
TI - Formation of Rearranged Grignard Reagents by Carbenoid-C-H Insertion This study
was supported by the Deutsche Forschungsgemeinschaft (SFB 260).
PMID- 10777643
TI - A New Biosynthetic Pathway to Alkaloids in Plants: Acetogenic Isoquinolines We
thank Dr. D. Marek and Dr. D. Moskau (Bruker AG, Fallanden, Switzerland), who
made the cryoprobe technique available to us, Prof. L. Ake Assi (Centre National
de Floristique, Abidjan Ivory Coast) for a long and fruitful collaboration on
Dioncophyllaceae and Ancistrocladaceae plants, and Dr. D. Scheutzow (Universitat
Wurzburg) for valuable advice. This work was supported by the Deutsche
Forschungsgemeinschaft (SFB 251 and Graduiertenkolleg "NMR in vivo und in
vitro"), by the Fonds der Chemischen Industrie, and by the Max-Buchner-Stiftung.
PMID- 10777644
TI - 6Li and (15)N NMR Data as a Probe for the Influence of Solvent and Intramolecular
Solvation on the Solution-State Structures of Chiral Lithium Amides The authors
are most grateful to the Swedish Natural Science Research Council and Carl
Trygger for financial support.
PMID- 10777645
TI - Low-Temperature, Catalyzed Growth of Indium Nitride Fibers from Azido-Indium
Precursors This work was supported by the U.S. National Science Foundation (Grant
CHE-9709104). We gratefully acknowledge assistance from Dr. W. R. Winchester with
GC-MS and Dr. Couture with X-ray fluorescence studies.
PMID- 10777646
TI - Oxidation - Reduction and Photochemical Reactions of Metalladecaborane Clusters:
The Interconversion of hypercloso-
PMID- 10777647
TI - Study of the Configuration Stability of the Carbon - Zinc Bond, Direct
Measurement of Enantiomeric Ratios, and Tentative Assignment of the Absolute
Configuration in Secondary Organozinc Halides We gratefully acknowledge the
financial support provided by the National Science Foundation (R.D.R.). We also
thank Dr. R. Shoemaker for his help in obtaining the NMR data.
PMID- 10777648
TI - Electrochemical Oxidation of Water to Dioxygen Catalyzed by the Oxidized Form of
the Bis(ruthenium - hydroxo) Complex in H(2)O This work was partly supported by
the Grant-in-Aid for Scientific Research on Priority Areas from the Ministry of
Education, Science, Sports, and Culture of Japan (No. 10149259).
PMID- 10777649
TI - Designing a Helical Polymer that Reverses its Handedness at a Selected,
Continuously Variable, Temperature We would like to thank R. L. B. Selinger for
helpful discussions. The Office of Naval Research supported the work at both the
Polytechnic University and the Naval Research Laboratory. The work at the
Polytechnic University was also supported by the Chemistry and Polymers Programs
of the National Science Foundation and by the Petroleum Research Fund
administered by the American Chemical Society. We are grateful to Professor
Krzysztof Matyjaszewski of Carnegie-Mellon University for a discussion that led
to the development of this work.
PMID- 10777650
TI - Piezoelectricity in Polar Supramolecular Materials This work was partly carried
out at the University of Illinois at Urbana-Champaign and supported by grants
from the Army Research Office (DAAH04-96-1-0450) and the Office of Naval Research
(N00014-99-1-0239). S.I.S. expresses his gratitude for the support of the
Humboldt Foundation in the form of a Senior Award.
PMID- 10777651
TI - Unusual Smectic Ordering of Unlocked Copper Bis-(terpyridine) Complexes This work
was supported by the Centre National de la Recherche Scientifique (CNRS) and by
the Engineering School of Chemistry (ECPM).
PMID- 10777652
TI - An Expeditious Total Synthesis of the Natural Stereomeric Mixture of Stenusine
Following a Possible Biogenetic Pathway We are grateful to Prof. Dr. Dieter
Enders for fruitful discussions.
PMID- 10777654
TI - AlITQ-6 and TiITQ-6: Synthesis, Characterization, and Catalytic Activity We thank
the Spanish CICYT for financial support (project MAT97-1016-C02-01 and project
MAT97-1207-C03-01). U.D. and M.E.D. thank the M.E.C. and M.E.A., respectively,
for funding their doctoral fellowships.
PMID- 10777653
TI - From Large Furan-Based Calixarenes to Calixpyrroles and Calix
PMID- 10777655
TI - Ligand-Directed Structural Modification of Imidotin(II) Cubanes: The Mixed
Oxidation State Double-Cubanes
PMID- 10777657
TI - Polymeric Layers Catenated by Ribbons of Rings in a Three-Dimensional Self
Assembled Architecture: A Nanoporous Network with Spongelike Behavior.
PMID- 10777656
TI - How Important is the Inert Matrix of Supported Enantiomeric Catalysts? Reversal
of Topicity with Two Polystyrene Backbones We would like to warmly thank Prof. J.
M. J. Frechet and Dr. F. Svec for technical advice. Financial support for this
work was provided by the Spanish C.I.C.Y.T. (Project MAT96-1053) and Fundacio
Caixa Castello-Bancaixa (P1B97-10).
PMID- 10777658
TI - Asymmetric Synthesis of an Organic Compound with High Enantiomeric Excess Induced
by Inorganic Ionic Sodium Chlorate This work was supported by a Grant-in-Aid for
Scientific Research from the Ministry of Education, Science, Sports, and Culture.
We thank Mr. Koji Ohtake for experimental work in the early stage, Prof. Naoyuki
Koide and Dr. Takashi Mihara from the Department of Chemistry of our university
for a microscope measurement of the size of the powdered NaClO(3).
PMID- 10777659
TI - A human cDNA library for high-throughput protein expression screening.
AB - We have constructed a human fetal brain cDNA library in an Escherichia coli
expression vector for high-throughput screening of recombinant human proteins.
Using robot technology, the library was arrayed in microtiter plates and gridded
onto high-density filter membranes. Putative expression clones were detected on
the filters using an antibody against the N-terminal sequence RGS-His(6) of
fusion proteins. Positive clones were rearrayed into a new sublibrary, and 96
randomly chosen clones were analyzed. Expression products were analyzed by SDS
PAGE, affinity purification, matrix-assisted laser desorption/ionization-time-of
flight mass spectrometry, and the determined protein masses were compared to
masses predicted from DNA sequencing data. It was found that 66% of these clones
contained inserts in a correct reading frame. Sixty-four percent of the correct
reading frame clones comprised the complete coding sequence of a human protein.
High-throughput microtiter plate methods were developed for protein expression,
extraction, purification, and mass spectrometric analyses. An enzyme assay for
glyceraldehyde-3-phosphate dehydrogenase activity in native extracts was adapted
to the microtiter plate format. Our data indicate that high-throughput screening
of an arrayed protein expression library is an economical way of generating large
numbers of clones producing recombinant human proteins for structural and
functional analyses.
PMID- 10777660
TI - Determination of X-chromosome inactivation status using X-linked expressed
polymorphisms identified by database searching.
AB - The large number of redundant sequences available in nucleotide databases
provides a resource for the identification of polymorphisms. Expressed
polymorphisms in X-linked genes can be used to determine the inactivation status
of the genes, and polymorphisms in genes that are subject to inactivation can
then be used as tools to examine X-chromosome inactivation status in heterozygous
females. In this study, we have identified six new X-linked single-nucleotide
polymorphisms and determined the inactivation status of these genes by
examination of expression patterns in female cells previously demonstrated to
have skewed inactivation, as well as by analysis of somatic cell hybrids
retaining the inactive human X chromosome. Expression was seen from both alleles
in females heterozygous for the RPS4X gene, confirming the previously reported
expression from the inactive X chromosome. Expression of only a single allele was
seen in females heterozygous for polymorphisms in the BGN, TM4SF2, ATP6S1, VBP1,
and PDHA1 genes, suggesting that these genes are subject to X-chromosome
inactivation.
PMID- 10777661
TI - Identification of a new EGF-repeat-containing gene from human Xp22: a candidate
for developmental disorders.
AB - Epidermal growth factor (EGF) repeat-containing proteins constitute an expanding
family of proteins involved in several cellular activities such as blood
coagulation, fibrinolysis, cell adhesion, and neural and vertebrate development.
By using a bioinformatic approach, we have identified a new member of this family
named MAEG (MAM- and EGF-containing gene; HGMW-approved gene symbol and gene
name). Sequence analysis indicates that MAEG encodes a secreted protein
characterized by the presence of five EGF repeats, three of which display a
Ca(2+)-binding consensus sequence. In addition, a MAM domain is also present at
the C-terminus of the predicted protein product. The human and murine full-length
cDNAs were identified and mapped to human Xp22 and to the mouse syntenic region.
Northern analysis indicates that MAEG is expressed early during development.
Taken together, these data render MAEG a candidate for human and murine
developmental disorders.
PMID- 10777662
TI - Physical interactions among human checkpoint control proteins HUS1p, RAD1p, and
RAD9p, and implications for the regulation of cell cycle progression.
AB - Schizosaccharomyces pombe hus1 promotes radioresistance and hydroxyurea
resistance, as well as S and G2 phase checkpoint control. We isolated a human
cDNA homologous to hus1, called HUS1. The major focus of this report is on a
detailed analysis of the physical interactions of the HUS1-encoded protein and
two other checkpoint control proteins, RAD1p and RAD9p, implicated in the
cellular response to DNA damage. We found that HUS1p interacts with itself and
the N-terminal region of RAD1p. In contrast, the C-terminal portion of the
checkpoint protein RAD9p is essential for interacting with HUS1p and the C
terminal region of RAD1p. Since the N-terminal portion of RAD9p was previously
demonstrated to participate in apoptosis, this protein likely has at least two
functional domains, one that regulates programmed cell death and another that
regulates cell cycle checkpoint control. Truncated versions of HUS1p are unable
to bind RAD1p, RAD9p, or another HUS1p molecule. RAD1p-RAD1p and RAD9p-RAD9p
interactions can be demonstrated by coimmunoprecipitation, but not by two-hybrid
analysis, suggesting that the proteins associate as part of a complex but do not
interact directly. Northern blot analysis indicates that HUS1 is expressed in
different tissues, but the mRNA is most predominant in testis where high levels
of RAD1 and RAD9 message have been detected. These studies suggest that HUS1p,
RAD9p, and RAD1p form a complex in human cells and may function in a meiotic
checkpoint in addition to the cell cycle delays induced by incomplete DNA
replication or DNA damage.
PMID- 10777663
TI - A clone contig of 12q24.3 encompassing the distal hereditary motor neuropathy
type II gene.
AB - We previously assigned the disease locus for autosomal dominant hereditary motor
neuropathy type II (distal HMN II) within a 13-cM interval at chromosome 12q24.3.
We constructed a physical map of the distal HMN II region based on yeast
artificial chromosomes (YACs), P1 artificial chromosomes (PACs), and bacterial
artificial chromosomes (BACs) using an STS content mapping approach. The contig
contains 26 YAC, 15 PAC, and 60 BAC clones and covers a physical distance of
approximately 5 Mb. A total of 99 STS markers, including 25 known STSs and STRs,
49 new STSs generated from clone end-fragments, 20 ESTs, and 5 known genes, were
located on the contig. This physical map provides a valuable resource for mapping
genes and markers located within the distal HMN II region and facilitates the
positional cloning of the distal HMN II gene.
PMID- 10777664
TI - Cloning and characterization of a novel human ubiquitin-specific protease, a
homologue of murine UBP43 (Usp18).
AB - The ubiquitin-specific proteases (UBP) are a family of enzymes that cleave
ubiquitin from ubiquitinated protein substrates. We have recently cloned UBP43, a
novel member of this family from AML1-ETO knock-in mice. To analyze the role of
UBP43 in hematopoiesis and leukemogenesis, we have cloned a full-length human
UBP43 cDNA by screening a human monocytic cDNA library as well as by 5'- and 3'
rapid amplification of cDNA ends analyses. This cDNA encodes a polypeptide of 372
amino acids with all of the structural motifs of a deubiquitinating enzyme. The
human UBP43 mRNA is strongly expressed in human liver and thymus. Transfection
analysis has demonstrated that UBP43 is a nuclear protein. Interestingly, the
gene encoding human UBP43 maps to chromosome 22q11.2. This region, known as
DiGeorge syndrome critical region, contains a minimal area of 2 Mb and is
consistently deleted in DiGeorge syndrome and related disorders. The syndrome is
marked by thymic aplasia or hypoplasia, parathyroid hypoplasia, or congenital
cardiac abnormalities. Taken together, our results broaden the understanding of a
new human ubiquitin-specific protease, UBP43, and suggest that this gene may also
be related to DiGeorge syndrome.
PMID- 10777665
TI - Characterization of Ngef, a novel member of the Dbl family of genes expressed
predominantly in the caudate nucleus.
AB - We have identified Ngef as a novel member of the family of Dbl genes. Many
members of this family have been shown to function as guanine nucleotide exchange
factors for the Rho-type GTPases. Ngef is predominantly expressed in brain, with
the strongest signal in the caudate nucleus, a region associated with the control
of movement. Ngef contains a translated trinucleotide repeat, a polyglutamic acid
stretch interrupted by a glycine. We have localized the Ngef gene to mouse
chromosome 1 and the human homologue of Ngef to human chromosome 2q37. We have
shown in preliminary experiments that Ngef has transforming potential in cell
culture and is able to induce tumors in nude mice.
PMID- 10777666
TI - Molecular characterization of germline NF2 gene rearrangements.
AB - Neurofibromatosis type 2 (NF2) is an autosomal dominant disease that causes a
predisposition to nervous system tumors. Deleterious point mutations have been
found in about 55% of NF2 patients, and large genomic deletions account for
approximately 33% of NF2 gene alterations. The majority of these deletions are
larger than 50 kb, with a breakpoint usually lying outside the NF2 gene. We
identified two cases of intragenic deletion with loss of 1.5 and 40 kb,
respectively. In both cases, one boundary of the deletion was located in or at
the proximity of an SVA sequence in NF2 intron 4. No sequence identity longer
than 5 bases and no signal of specific recombination have been evidenced on
either side of the deletion breakpoints. These observations are compatible with a
nonhomologous recombination being responsible for the genomic deletions. In a
third case, a paracentric inversion of chromosome 22 was found. This chromosomal
rearrangement breaks the NF2 gene in two parts and carries the first NF2 exon in
a juxta-centromeric position. The variability in position of the deletions and
the observation of a new chromosomal rearrangement in the NF2 gene underscore the
importance of FISH analysis in the molecular diagnosis of NF2.
PMID- 10777667
TI - Molecular cytogenetic evaluation in a patient with a translocation (3;21)
associated with blepharophimosis, ptosis, epicanthus inversus syndrome (BPES).
AB - Blepharophimosis, ptosis, epicanthus inversus syndrome type I (BPES; OMIM 110100)
is an autosomal dominant disorder affecting craniofacial development and ovarian
function. We have identified a patient with BPES who carried a de novo reciprocal
translocation [46, XX,t(3;21)(q23;q22.1)]. Fluorescence in situ hybridization
analysis at band 3q23 using probes derived from BAC 175G20 (Research Genetics),
PACs 108L15 and 169C10 (RPCI1), and cosmids AC174D4, AC68D3, AC44F5, and AC125C5
(Lawrence Livermore National Laboratory) was performed. The patient's breakpoint
was found to lie within the overlapping region of the BAC and PACs but
centromeric to all the cosmids. However, a 10.5-kb BamHI-digested fragment,
common to the BAC and PAC clones, was shown to cross the breakpoint. The results
have placed our patient's breakpoint proximal to that of the previously reported
patient [46,XY,t(3;4)(q23;p15.2)] and within a 10.5-kb interval. This is the
second patient in which a breakpoint was refined by molecular cytogenetics. Our
findings emphasize the significance of this region for BPES.
PMID- 10777669
TI - Identification and characterization of human ZNF274 cDNA, which encodes a novel
kruppel-type zinc-finger protein having nucleolar targeting ability.
AB - A human cDNA encoding a novel zinc-finger protein, ZNF274, was identified by the
"nuclear transportation trap" method (Ueki, N., Oda, T., Kondo, M., Yano, K.,
Noguchi, T., and Muramatsu, M., 1998, Nat. Biotechnol. 16: 1338-1342). Based on
sequence analysis of the full-length cDNA, this novel gene has two alternative
splicing forms, ZNF274a and ZNF274b, which encode putative proteins of 621 and
584 amino acids, respectively. ZNF274a contains five C2H2-type zinc-finger
motifs, two KRAB-A (Kruppel-associated box) domains, and one leucine-rich domain.
ZNF274b lacks the first KRAB-A domain at the N-terminus. ZNF274 mRNA is detected
in various human tissues by Northern analysis. The ZNF274 gene is mapped distal
to marker RP S28 1 in the human chromosome 19qter region, by RH mapping. The KRAB
domains of ZNF274 exhibited transcription repressor activity when tested in GAL4
fusion protein assays. EGFP-ZNF274 fusion protein expressed in COS7 cells
predominantly localized to the nucleoli. A series of deletion constructs revealed
that a minimal domain consisting of the third and fourth zinc-fingers possesses
nucleolar targeting ability. These results suggest that ZNF274 is a ubiquitous
transcription repressor that plays a role in the nucleoli.
PMID- 10777668
TI - Cloning and expression analysis of a novel gene, RP42, mapping to an autism
susceptibility locus on 6q16.
AB - We isolated a novel mouse gene, RP42, in a systematic search for genes expressed
in proliferating neuroblasts whose human orthologs map to susceptibility loci for
autism. This gene is intronless and encodes a putative 259-amino-acid protein
that exhibits 30-36% overall sequence identity to a fission yeast and a nematode
protein (GenPept Accession Nos. CAA17006 and CAB54261). Nevertheless, no homology
to any known gene was found. RP42 has developmentally regulated expression,
particularly in proliferating neuroblasts from which neocortical neurons
originate. Its human ortholog is located in a cluster of embryonic neuronally
expressed genes on the 6q16 chromosome, making it a positional candidate
susceptibility gene for autism.
PMID- 10777670
TI - Comparative mapping of the human homologue of the rat diabetes susceptibility
gene lyp to a 1.3-Mb segment on HSA7.
AB - The rat diabetes susceptibility gene, Lyp or Lymphopenia, has been localized to
RNO4. Proximal to Lyp are the genes caspase-2 (Casp2) and pancreatic trypsin 1
(Prss1), while neuropeptide Y (Npy) is the closest distally positioned gene. In
human, the three genes are syntenic on HSA7, but they are not on a conserved
segment: CASP2 and PRSS1 are localized to 7q35, while NPY is localized to 7p15.1.
This raises the question whether the human homologue of Lyp is linked to
CASP2/PRSS1 or to NPY. We present a comparative map of the Lyp region in rat and
human, assigning the gene to a 1.3-Mb segment between RNY3 and ABP1 at 7q35.
PMID- 10777671
TI - Linkage of human narcolepsy with HLA association to chromosome 4p13-q21.
AB - Although narcolepsy is highly associated with human leukocyte antigen (HLA)
DQ6/DQB1*0602 and/or DR2/DRB1*1501, most individuals with the HLA haplotype are
free of narcolepsy. This indicates that HLA alone makes a relatively small
contribution to the development of narcolepsy and that a non-HLA gene(s) can
contribute to the genetic predisposition even in narcoleptic cases with HLA
association. We conducted a genome-wide linkage search for narcolepsy in eight
Japanese families with 21 DR2-positive patients (14 narcoleptic cases with
cataplexy and 7 cases with an incomplete form of narcolepsy). A lod score of 3.09
suggested linkage to chromosome 4p13-q21. A lod score of 1.53 was obtained at the
HLA-DRB1 locus, though this lod score may be biased since all the affected
patients and many of the family members were DR2-positive. No other loci
including hypocretin, hypocretin receptor 1, and hypocretin receptor 2 had lod
scores greater than 1.0. The present study suggests that chromosome 4p13-q21
contains a second locus for HLA-associated human narcolepsy.
PMID- 10777672
TI - Zinc increases the activity of vitamin D-dependent promoters in osteoblasts.
AB - Zinc modulates the structure and binding of the DNA binding domain of the
1alpha,25-dihydroxyvitamin D(3) receptor to specific vitamin D response element
DNA (Nature Biotechnology 16, 262-266, 1998). To determine whether zinc alters
1alpha,25-dihydroxyvitamin D(3)-regulated genes in cells, we permanently
transfected rat osteoblasts with two vitamin D-dependent promoter-reporter
systems and examined their responses to 1alpha,25-dihydroxyvitamin D(3) in the
presence of increasing amounts of extracellular zinc. When extracellular zinc
concentrations were increased in the presence of 1alpha,25-dihydroxyvitamin D(3),
there was an increase in the activity of 1alpha,25-dihydroxyvitamin D(3)
dependent promoters with increasing concentrations of zinc. The effect was
specific for zinc since metals such as copper failed to increase the activity of
1alpha,25-dihydroxyvitamin D(3)-dependent promoters. The concentration of the
vitamin D receptor within the cell and the affinity of 1alpha,25-dihydroxyvitamin
D(3) for its receptor remained unchanged with added zinc. Our results show that
zinc increases the activity of 1alpha,25-dihydroxyvitamin D(3)-dependent
promoters in osteoblasts.
PMID- 10777673
TI - Molecular cloning and genomic structure of human frizzled-3 at chromosome 8p21.
AB - WNT receptors encoded by the Frizzled genes are implicated in carcinogenesis as
well as in embryonic development. Human Frizzled-3 (FZD3) gene, encoding seven
transmembrane receptor with the N-terminal cysteine-rich domain, has been cloned
and characterized. Expression of the FZD3 mRNAs was investigated by using three
FZD3 specific probes: HF3S1, corresponding to the 5'-UTR and a part of the coding
region; HF3S2, corresponding to a part of the coding region; HF3S3, corresponding
to the 3'-UTR. HF3S1 and HF3S2 hybridized to the 14.0-, 9.0-, 4.0- and 1.8-kb
FZD3 mRNA, while HF3S3 hybridized to the 14.0-, 9.0-, and 4.0-kb FZD3 mRNA. The
14. 0-kb FZD3 mRNA was the major transcript in fetal brain and adult cerebellum,
while the 1.8-kb FZD3 mRNA was the major transcript in adult pancreas, and many
cancer cell lines examined. The 1.8-kb FZD3 mRNA, alternatively polyadenylated by
the internal AATAAA signal in the coding region, is predicted to encode the
truncated FZD3 protein lacking the region through the second extracellular loop
to the C-terminal tail, and might function as the transmembrane-type antagonist
for WNTs. The FZD3 gene consists of 8 exons, and has been mapped to human
chromosome 8p21.
PMID- 10777674
TI - Contribution of the carboxy-terminal domain of lipoprotein lipase to interaction
with heparin and lipoproteins.
AB - The C-terminal domain of lipoprotein lipase (LPL) is involved in several
important interactions. To assess its contribution to the binding ability of full
length LPL we have determined kinetic constants using biosensor technique. The
affinity of the C-terminal domain for heparin was about 500-fold lower than that
of full-length LPL (K(d) = 1.3 microM compared to 3.1 nM). Replacement of Lys403,
Arg405 and Lys407 by Ala abolished the heparin affinity, whereas replacement of
Arg420 and Lys422 had little effect. The C-terminal domain increased binding of
chylomicrons and VLDL to immobilized heparin relatively well, but was less than
10% efficient in binding of LDL compared to full-length LPL. Deletion of residues
390-393 (WSDW) did not change the affinity to heparin and only slightly decreased
the affinity to lipoproteins. We conclude that the C-terminal folding domain
contributes only moderately to the heparin affinity of full-length LPL, whereas
the domain appears important for tethering triglyceride-rich lipoproteins to
heparin-bound LPL.
PMID- 10777675
TI - Oligosaccharide trimming plays a role in the endoplasmic reticulum-associated
degradation of tyrosinase.
AB - The effect of glucosidase and mannosidase inhibitors on the ER-associated
degradation of tyrosinase was assessed in transiently transfected COS-7 cells. We
found that the glucosidase inhibitors castanospermine and deoxynojirimycin had
very little effect on tyrosinase degradation, whereas the mannosidase inhibitors
deoxymannojirimycin and kifunensine significantly delayed the rate of tyrosinase
degradation as measured by pulse-chase analysis. In addition, we show that
tyrosinase degradation is sensitive to the proteasome inhibitor lactacystin and
that tyrosinase associates with endogenous calnexin in COS-7 cells. Our data
support a model of tyrosinase degradation that involves mannose trimming,
calnexin association, and the retrograde transport of tyrosinase from the ER to
the cytosol for proteasomal degradation. The pathways of tyrosinase degradation
have important ramifications with regard to the exact types of antigenic epitopes
that are presented to the immune system.
PMID- 10777676
TI - Cloning and initial characterization of the human DPYD gene promoter.
AB - Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme in the
degradation of pyrimidine bases and pyrimidine-based antimetabolites. Reduced DPD
activity is associated with toxicity to 5-fluorouracil (5FU) therapy in cancer
patients and with neurological abnormalities in paediatric patients. Although
variant DPYD alleles have been identified in DPD-deficient patients, they do not
adequately explain polymorphic DPD activity or associated clinical phenotypes in
vivo. DPD may be transcriptionally regulated as mRNA levels correlate with
activity and are differentially regulated in human tissues. A 1.85 kb 5' flanking
region of the human DPYD gene was cloned and has transcriptional activity in
cultured cells. Analysis of this 5' flanking region in rhesus and cynomolgus
monkeys demonstrated conservation (>96%) between humans and primates. Putative
binding sites for ubiquitous and cell-specific factors were identified. A
polymorphism that disrupts a putative gamma-interferon response element was
identified in a cancer patient with reduced DPD activity and severe 5FU toxicity.
Further insight into regulation of DPD expression may identify new avenues for
the treatment of clinical problems associated with DPD deficiency.
PMID- 10777677
TI - Rat basophilic leukemia cells express syntaxin-3 and VAMP-7 in granule membranes.
AB - In neuronal cells, it is generally agreed that SNARE proteins underlie the
release of neurotransmitter. It is controversial, however, whether they also work
functionally in the degranulation of RBL-2H3 cells because the expression of
SNARE proteins has not been confirmed and the degranulation is not inhibited by
tetanus toxin which cleaves one of SNARE proteins, VAMP-2. We investigated the
expression and the localization of SNARE proteins including VAMP-7 which is
insensitive to tetanus toxin. RT-PCR analysis showed the existence of SNARE
proteins, including syntaxin-2, -3, -4, SNAP-23, VAMP-2, and VAMP-7. Experiments
using GFP-conjugated proteins revealed that VAMP-7 was localized only in granule
membranes, whereas syntaxin-3 was in both the plasma and granule membranes. Upon
antigen stimulation, these proteins in granule membranes moved to the cell
surface due to the fusion of granules with the plasma membrane. The results
suggest the involvement of SNARE proteins in the degranulation of RBL-2H3 cells.
PMID- 10777678
TI - The product of the ABC half-transporter gene ABCG2 (BCRP/MXR/ABCP) is expressed
in the plasma membrane.
AB - The products of the ABC gene family can be generally classified as either full
transporters of half-transporters. Full-transporters are expressed in the plasma
membrane, whereas half-transporters are usually found in intracellular membranes.
Recently, an ABC half-transporter, the ABCG2 gene product Breast
Cancer/Mitoxantrone Resistance Protein (BCRP/MXR), has been shown to cause
mitoxantrone and topotecan resistance. The purpose of this study was to determine
the expression and the intracellular localization of this protein in various drug
resistant cell lines. BCRP/MXR expression was determined by Western blot and
immunohistochemistry. This protein is highly overexpressed in several drug
resistant cell lines and localizes predominantly to the plasma membrane, instead
of to intracellular membranes as seen with all other known half-transporters.
Therefore, BCRP/MXR is unique among the ABC half-transporters by being localized
to the plasma membrane.
PMID- 10777679
TI - Interrelations between plasma homocysteine and intracellular S
adenosylhomocysteine.
AB - S-Adenosylhomocysteine, a potent intracellular methylation inhibitor, is
suggested as a potential mediator for hyperhomocysteinemia-related vascular
changes. We investigated the effect of acute and chronic hyperhomocysteinemia on
intracellular S-adenosylhomocysteine and S-adenosylmethionine in rats and humans.
Elevated plasma homocysteine in rats infused with homocysteine produced an
increase in S-adenosylhomocysteine (P < 0.001) but not S-adenosylmethionine
levels (P > 0.05) in various rat tissues. However intraerythrocyte S
adenosylhomocysteine and S-adenosylmethionine levels were not changed in
homocysteine-infused rats and human subjects with experimentally acute
hyperhomocysteinemia by methionine loading test. In contrast, erythrocyte S
adenosylhomocysteine levels were significantly higher in chronic renal failure
patients, who had chronically elevated plasma homocysteine levels, than in either
vascular disease patients or healthy controls (P < 0.05). In conclusion, acute
hyperhomocysteinemia can increase intracellular S-adenosylhomocysteine levels in
tissues actively involved in homocysteine metabolism. The findings are relevant
to homocysteine-related endothelial dysfunction since S-adenosylhomocysteine
modulates endothelial cell apoptosis.
PMID- 10777680
TI - Cry1Ac protoxin from Bacillus thuringiensis sp. kurstaki HD73 binds to surface
proteins in the mouse small intestine.
AB - Bacillus thuringiensis (Bt), considered a safe insecticide, produces insecticidal
proteins named Cry during sporulation, which possess exceptional immunological
properties. In this work using an immunohistochemical test we demonstrated that
Cry1Ac protoxin (pCry1Ac) binds to the mucosal surface of the mouse small
intestine. Ligand blot assay allowed us to detect, under denaturing conditions,
six pCry1Ac-binding polypeptides present in brush border membrane vesicles
isolated from the small intestine. Moreover, this protein induced in situ
temporal changes in the electrophysiological properties of the mouse jejunum. The
data obtained indicate a possible interaction in vivo of Cry proteins with the
animal bowel which could induce changes in the physiological status of the
intestine.
PMID- 10777681
TI - Tyrosine 50 at the subunit interface of dimeric human glutathione transferase P1
1 is a structural key residue for modulating protein stability and catalytic
function.
AB - The dimer interface in human GSTP1-1 has been altered by site-directed
mutagenesis of Tyr50. It is shown that the effects of some mutations of this
single amino acid residue are as detrimental for enzyme function as mutations of
Tyr8 in the active site. The dimeric structure is a common feature of the soluble
glutathione transferases and the structural lock-and-key motif contributing to
the subunit-subunit interface is well conserved in classes alpha, mu, and pi. The
key residue Tyr50 in GSTP1-1 was replaced with 5 different amino acids with
divergent properties and the mutant proteins expressed and characterized. Mutant
Y50F is an improved variant, with higher thermal stability and higher catalytic
efficiency than the wild-type enzyme. The other mutants studied are also dimeric
proteins, but have lower stabilities and catalytic activities that are reduced by
a factor of 10(2)-10(4) from the wild-type value. Mutants Y50L and Y50T are
characterized by a markedly increased K(M) value for GSH, while the effect is
mainly due to decreased k(cat) values for mutants Y50A and Y50R. In conclusion,
residue 50 in the interface governs both structural stability and catalytic
function.
PMID- 10777682
TI - The beta(2) subunit of soluble guanylyl cyclase contains a human-specific
frameshift and is expressed in gastric carcinoma.
AB - Soluble or nitric oxide (NO) stimulated guanylyl cyclases are obligate heme
containing heterodimers (alpha/beta). We report the full-length cDNA of the human
ortholog of the rat beta(2)-subunit from human kidney. A database search yielded
matches of the 3' non-coding sequence with previously unassigned expressed
sequence tags from kidney and stomach signet ring cell carcinoma. PCR comparison
of cDNA from stomach signet ring cell carcinoma and normal stomach tissue
demonstrated beta(2) subunit expression in cancer but not in normal tissue. On
the cDNA level a frameshift deletion of one nucleotide was present in the novel
human sequence which was confirmed on the genomic DNA level. In four closely
related nonhuman primate species the frameshift deletion was absent while
analysis of genomic DNA from different ethnic backgrounds revealed the uniform
presence of the frameshift deletion in the human population.
PMID- 10777683
TI - IgG-coated erythrocytes augment LPS-stimulated TNF-alpha secretion, TNF-alpha
mRNA levels, and TNF-alpha mRNA stability in macrophages.
AB - Previous studies have shown that IgG-coated erythrocytes (EIgG) augment the LPS
stimulated increase in serum TNF-alpha levels in animals and the LPS-stimulated
secretion of TNF-alpha by isolated macrophages. The present study evaluated the
mechanism for the effect of EIgG on LPS-stimulated TNF-alpha secretion in the
murine macrophage cell line, RAW 264.7. Incubation of the macrophages with EIgG
or IgG-coated glass beads caused a dose-dependent augmentation of LPS-stimulated
TNF-alpha secretion. The addition of EIgG increased the rate of LPS-stimulated
TNF-alpha protein secretion between 2 and 4 hr after LPS. Accordingly, EIgG
increased the levels of TNF-alpha mRNA at 2 and 3 hr after LPS. The increase in
the LPS-stimulated TNF-alpha mRNA levels caused by EIgG was associated with an
increase in TNF-alpha mRNA stability. Thus, the augmentation of LPS-stimulated
TNF-alpha secretion by EIgG was associated with an increase in TNF-alpha mRNA
levels which at least partly resulted from an increase in the stability of TNF
alpha mRNA.
PMID- 10777684
TI - Involvement of tail domains in regulation of Dictyostelium myosin II.
AB - The actin-dependent ATPase activity of Dictyostelium myosin II filaments is
regulated by phosphorylation of the regulatory light chain. Four deletion mutant
myosins which lack different parts of subfragment 2 (S2) showed phosphorylation
independent elevations in their activities. Phosphorylation-independent elevation
in the activity was also achieved by a double point mutation to replace conserved
Glu932 and Glu933 in S2 with Lys. These results suggested that inhibitory
interactions involving the head and S2 are required for efficient regulation.
Regulation of wild-type myosin was not affected by copolymerization with a S2
deletion mutant myosin in the same filaments. Furthermore, the activity linearly
correlated with the fraction of phosphorylated molecules in wild-type filaments.
These latter two results suggest that the inhibitory head-tail interactions are
primarily intramolecular.
PMID- 10777685
TI - Effect of estradiol on neuronal Swedish-mutated beta-amyloid precursor protein
metabolism: reversal by astrocytic cells.
AB - Alzheimer's disease is the most frequent neurodegenerative disorder in the aged
population and is characterized by the deposition of the 40/42-residue amyloid
beta protein (Abeta), a proteolytic fragment of the beta-amyloid precursor
protein (APP). Recently, it has been shown that physiological doses of estradiol
reduce the generation of endogenous Abeta in primary cortical neurons. Here we
investigate the influence of estrogen in amyloidogenesis and sAPPalpha secretion
in the CNS. By means of primary cortical neurons overexpressing humanized
APP(695) bearing the Swedish mutation (hAPP(695sw)), we analyzed APP maturation
in the absence or in the presence of estrogen. We show that estrogen at a 2
microM concentration increases the release of the neuroprotective sAPPalpha
fragment but does not reduce the release of Abeta in primary neurons
overexpressing the Swedish-mutated form of APP. Furthermore, neurons cocultured
with astrocytic cells or grown with astrocytes conditioned media do not exhibit
the estrogen-induced increase in sAPPalpha secretion. Altogether, our data
indicate that astrocytes interfere with estrogen in the regulation of sAPPalpha
secretion, probably via secreted factor(s).
PMID- 10777686
TI - Decreased ADP-ribosylation of the Galpha(olf) and Galpha(s) subunits by high
glucose in pancreatic B-cells.
AB - In HIT-T15 insulinoma B-cells incubated in presence of [(32)P]NAD, we identified
by autoradiography and immunoblotting ADP-ribosylation (ADP-R) of the trimeric G
protein Galpha(s) and Galpha(olf) subunits (45 kDa) induced by cholera toxin in
M1 (120,000g) and M2 (70,000g) subcellular fractions containing plasma membranes,
insulin granules, and mitochondria. This ADP-R indicates that these two fractions
contain functionally competent Galpha subunits for adenylyl cyclase activation.
Prolonged exposure of HIT-T15 cells to high glucose (25 mM instead of 6 mM)
specifically reduced the ADP-R in Galpha(s) and Galpha(olf) subunits in the M1
fraction only, despite the clear increase of their accumulation in this
compartment. A similar alteration in the ADP-R of the M1-associated Galpha(s) and
Galpha(olf) subunits was observed in pancreatic islets isolated from fasted and
fed rats. These results may explain, at least in part, the undesirable effects of
sustained hyperglycemia on the cAMP-dependent process of insulin secretion in
diabetes.
PMID- 10777687
TI - An SP1-like cis-element is the major DNA motif for differential expression
regulation of the adipocyte amino acid transporter.
AB - Adipocyte amino acid transporter (AAAT) is induced during the 3T3-L1 preadipocyte
differentiation process. In the -1819-bp 5'-upstream flanking region of the AAAT
genomic gene, six DNase I protected sites were identified by using the 3T3-L1
adipocyte nuclear extract. Results of chloramphenicol acetyltransferase (CAT)
expression from the chimeric AAAT promoter-driven CAT reporter gene indicated
that one protein binding site, from -68 to -26, was essential for the promoter
activity. However, this protein binding site does not contain recognition sites
of the transcription factors important for adipocyte differentiation, i.e., the
C/EBP or PPAR family. Further analysis revealed that the DNA sequence,
TTCAAGTCCCGCCCTCCGCT from -65 to -46, was the cis-element essential and partially
sufficient for inducible activity of the AAAT gene promoter.
PMID- 10777688
TI - Differential expression of the adipocyte amino acid transporter is transactivated
by SP1 and SP3 during the 3T3-L1 preadipocyte differentiation process.
AB - It was identified that a Sp1-like cis-element in the adipocyte amino acid
transporter gene (AAAT) promoter is the major cis-motif for its induced
expression during the 3T3-L1 preadipocyte differentiation process.
Electrophoretic mobility shift analysis of this cis DNA element showed that the
transcription factors binding to this sequence were Sp1 and Sp3. Protein analysis
of Sp1 and Sp3 in nuclear extracts from 3T3-L1 cells at various differentiation
stages indicated that these two transcription factors existed in noninduced 3T3
L1 preadipocytes, but they did not bind to the AAAT promoter element with high
affinity. They were activated after differentiation induction. It was further
demonstrated that dephosphorylation of Sp1 increased its binding affinity to this
inducible AAAT promoter element.
PMID- 10777689
TI - Direct immunization of malaria DNA vaccine into the liver by gene gun protects
against lethal challenge of Plasmodium berghei sporozoite.
AB - The liver is the first target organ for malaria parasites immediately after the
bite of an infected mosquito. We studied local immunization of malaria DNA
vaccines at the site of the liver using a gene gun as a useful tool for in vivo
transfection of foreign genes. A malaria DNA vaccine consisting of the Plasmodium
berghei circumsporozoite protein (PbCSP) gene plus the mouse IL-12 gene was
bombarded directly by a gene gun into mouse liver once or into the skin twice. A
marked protective effect was induced by gene bombardment into the liver (more
than 71%) compared with that into the skin (less than 33%). A Th1-type immune
response and high production of iNOS were observed in the hepatic lymphocytes
from mice bombarded into the liver, resulting in more effective protection
compared with those bombarded into the skin. These results provide an important
implication on the development of efficient malaria vaccine strategies.
PMID- 10777690
TI - Nestin-expressing cells in the pancreatic islets of Langerhans.
AB - The pancreatic islets of Langerhans produce several peptide hormones,
predominantly the metabolically active hormones insulin and glucagon, which are
critical for maintaining normal fuel homeostasis. Some evidence exists that
pancreatic endocrine cells turn over at a slow rate and can regenerate in certain
conditions. This could be due to the presence of pluripotent cells residing in
the pancreas. Recently the intermediate filament protein nestin has been
identified to be a marker for a multipotent stem cell in the central nervous
system. Given the similarity between the pancreatic islets and neuronal cells, we
hypothesized that stem cells expressing nestin might be present in the pancreas.
Here we present evidence that a subset of cells in the pancreatic islets express
the stem cell marker nestin. These cells might serve as precursors of
differentiated pancreatic endocrine cells.
PMID- 10777691
TI - Enhanced detection of deleterious and other germline mutations of hMSH2 and hMLH1
in Japanese hereditary nonpolyposis colorectal cancer kindreds.
AB - Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal, dominantly
inherited cancer-prone syndrome. Here, we describe a novel and efficient approach
for screening mutations of two major HNPCC susceptibility genes, hMSH2 and hMLH1.
The system consists of RNA extraction from whole blood treated with the
translation inhibitor, followed by long RT-PCR of the entire coding regions
combined with direct sequencing. In analysis of 15 kindreds suspicious for HNPCC,
8 samples were subjected to analysis after puromycin treatment and 7 samples were
analyzed without puromycin treatment. Three deleterious mutations were detected
in the kindreds with puromycin treatment, while none were observed in those
without puromycin. Signals from mutated alleles were enhanced after puromycin
treatment and easily distinguished from the wild-type allele, achieved by
suppression of nonsense-mediated mRNA decay. Furthermore, 12 other mutations were
detected in 15 kindreds. The system is considered to be a reliable and useful
approach for detecting germline mutations of hMSH2 and hMLH1 in HNPCC kindreds.
PMID- 10777693
TI - Expression of interleukin-1beta, interleukin-1 receptor, and interleukin-1
receptor antagonist mRNA in rat carotid artery after balloon angioplasty.
AB - Interleukin-1beta (IL-1beta) is a pleiotropic cytokine capable of inducing smooth
muscle activation and leukocyte recruitment in restenosis and atherosclerosis.
Our present study investigated the expression of IL-1beta, IL-1 receptor
antagonist (IL-1ra), and IL-1 receptor (IL-1RI and IL-1RII) mRNA in carotid
artery after balloon angioplasty using semiquantitative reverse
transcription/polymerase chain reaction (RT/PCR) and Northern analysis. Time
course studies revealed that IL-1beta mRNA was rapidly induced at 6 h (30-fold
increase over control, P < 0.001) post balloon injury and diminished to basal
levels at 24 h. The increased expression of IL-1ra mRNA was delayed, reaching a
peak at 24 h (400-fold increase, P < 0.001) and sustained up to 14 days. The
expression of IL-1RII mRNA was remarkably similar to that of IL-1beta, whereas
the IL-1RI (the signaling receptor) mRNA expression was delayed (significantly
induced at day 1; 14.2-fold increase, P < 0.01) post balloon injury.
Immunohistochemical studies revealed a strong induction of IL-1beta in the area
with actively proliferating and migrating smooth muscle cells (i.e., in the inner
medial layer at day 1 and in neointima at day 14 after balloon injury). The
differential but concomitant expression of IL-1beta, IL-1ra, IL-1RI, and IL-1RII
mRNAs after balloon angioplasty suggests that each of these IL-1 system
components may play a distinct role in neointima formation.
PMID- 10777692
TI - In situ RT-PCR detection of CYP1A mRNA in pharyngeal epithelium and chondroid
cells from chemically untreated fish: involvement in vertebrate craniofacial
skeletal development?
AB - Knowledge about the expression sites of cytochrome P450 1A (CYP1A) mRNA is
crucial for a better understanding of the physiological function of CYP1A. We
investigated the cellular localization of CYP1A mRNA in chemically untreated fish
by use of an in situ reverse transcription-polymerase chain reaction (IS RT-PCR)
technique. The fathead minnow (Pimephales promelas) was formalin-fixed, and
paraffin-embedded. Sections (5 microm) were treated with trypsinogen. Following
reverse transcription of CYP1A mRNA, the cDNA was amplified in situ by PCR with
specific primers. Detection of the amplicons was accomplished by a second PCR
performed with digoxigenin-labeled dUTP. CYP1A mRNA expression was detected in
cytoplasm of chondroid cells surrounding hyaline cartilage in gill arches. This
result was consistent with that of immunohistochemical analysis with a CYP1A1
specific monoclonal antibody. CYP1A mRNA also was found in stratified squamous
epithelium of the pharynx and gill arches, but no staining was detected in those
cells by immunohistochemical analysis. The results indicate that IS RT-PCR is an
effective/sensitive technique for localizing low level CYP1A expression. In
addition, the sites where we identified expression of CYP1A are targets of
retinoic acid, sonic hedgehog and Hox genes, suggesting that functional CYP1A in
vertebrates could participate in craniofacial skeletal development through
involvement in the retinoic acid signaling cascade.
PMID- 10777694
TI - Human adrenoleukodystrophy protein and related peroxisomal ABC transporters
interact with the peroxisomal assembly protein PEX19p.
AB - Four ABC half transporters (ALDP, ALDRP, PMP70, and PMP69) have been identified
in the mammalian peroxisomal membrane but no function has been unambiguously
assigned to any of them. To date X-linked adrenoleukodystrophy (X-ALD) is the
only human disease known to result from a defect of one of these ABC
transporters, ALDP. Using the yeast two-hybrid system and in vitro GST pull-down
assays, we identified the peroxin PEX19p as a novel interactor of ALDP, ALDRP,
and PMP70. The cytosolic farnesylated protein PEX19p was previously shown to be
involved in an early step of the peroxisomal biogenesis. The PEX19p interaction
occurs in an internal N-terminal region of ALDP which we verified to be important
for proper peroxisomal targeting of this protein. Farnesylated wild-type PEX19p
and a farnesylation-deficient mutant PEX19p did not differ in their ability to
bind to ALDP. Our data provide evidence that PEX19p is a cytosolic acceptor
protein for the peroxisomal ABC transporters ALDP, PMP70, and ALDRP and might be
involved in the intracellular sorting and trafficking of these proteins to the
peroxisomal membrane.
PMID- 10777695
TI - XSIP1, a member of two-handed zinc finger proteins, induced anterior neural
markers in Xenopus laevis animal cap.
AB - We characterized Xenopus SIP1 (XSIP1), Smad interacting protein, from activin
treated animal caps by differential screening. The XSIP1 is very similar to mouse
SIP1 in the protein coding region including the zinc finger domain and
homeodomain. The expression pattern was analyzed by RT-PCR and whole mount in
situ hybridization. XSIP1 expression was initially restricted to the dorsal
marginal zone in the late gastrula and was subsequently expressed at the lateral
edge of neural plate and, in the tailbud stage, in the forebrain, neural tube,
and eye. Overexpression of XSIP1 at the animal caps resulted in activation of
anterior neural markers without mesodermal markers. Ectopic expression of XSIP1
induced enlargement of neural cells and disordered eye formation. In addition to
abnormal head phenotypes, many embryos were short-tailed. Our findings suggest
that XSIP1 is a transcriptional repressor, which may be involved in the activin
dependent signal pathway.
PMID- 10777696
TI - The inhibitory effects of vasoactive intestinal peptide and pituitary adenylate
cyclase-activating polypeptide on osteoclast formation are associated with
upregulation of osteoprotegerin and downregulation of RANKL and RANK.
AB - The presence of a network of peptidergic nerve fibers in the skeleton, expressing
several neuropeptides including vasoactive intestinal peptide (VIP), has been
demonstrated. This observation, together with our findings in vitro showing that
VIP can regulate the activities of osteoblasts and osteoclasts as well as the
recruitment of osteoclasts, has suggested the existence of a neuro-osteogenic
interplay in bone metabolism. In the present study, the effects of VIP and
pituitary adenylate cyclase-activating polypeptide (PACAP), two members of the
VIP/secretin/glucagon superfamily, on osteoclast formation and mRNA expression of
three key regulatory proteins involved in osteoclast formation have been
investigated. VIP, PACAP-27, and PACAP-38, at concentrations of 10(-6) M, all
significantly inhibited formation of tartrate-resistant acid phosphatase-positive
multinuclear cells (TRAP + MNC) in mouse bone marrow cultures stimulated by 1,
25(OH)(2)-vitamin D3 (D3; 10(-8) M). By using semiquantitative RT-PCR, it was
found that D3 upregulated the mRNA expressions of receptor activator of NF-kappaB
ligand (RANKL) and receptor activator of NF-kappaB (RANK), whereas the expression
of osteoprotegerin (OPG) was downregulated in mouse bone marrow cultures
stimulated by D3 for 7 days. Both VIP and PACAP-38 decreased the stimulatory
effects of D3 on RANKL and RANK expression, whereas the inhibitory effect of D3
on OPG expression was reversed by VIP and PACAP-38. These observations indicate
that the inhibitory effects of VIP and PACAP on osteoclast recruitment are due to
regulation of the expression of key proteins involved in later stages of
osteoclast differentiation.
PMID- 10777697
TI - Small heat shock protein 27 (HSP27) associates with tubulin/microtubules in HeLa
cells.
AB - One of the monoclonal antibodies raised against mitotic HeLa cells (termed as
mH3) recognized a 27-kDa protein and stained microtubules in the mitotic spindles
of HeLa cells. Immunoscreening of a HeLa cDNA library revealed that mH3 antigen
is a small heat shock protein, HSP27. Immunoprecipitation analysis using mH3
suggested that both alpha- and beta-tubulin are associated with HSP27. Further,
sucrose-cushioned ultra centrifugation revealed that HSP27 is co-sedimented with
taxol-stabilized microtubules. These results indicate that HSP27 associates with
tubulin/microtubules in HeLa cells.
PMID- 10777698
TI - Differential expression of sense and antisense transcripts of the mitochondrial
DNA region coding for ATPase 6 in fetal and adult porcine brain: identification
of novel unusually assembled mitochondrial RNAs.
AB - The mammalian mitochondrial genome is a double-stranded circular DNA molecule,
which is transcribed from both strands as polycistronic RNAs, which are further
processed to yield the mature polyadenylated mRNAs, rRNAs and tRNAs. We compared
the gene expression patterns of foetal and adult porcine brains and identified a
sequence tag from the ATPase 6 region of the mitochondrial genome which, in adult
brain, was more abundant in the sense (H-strand) form, but, in foetal brain, more
abundant in the antisense form (L-strand). By means of solution hybridisation/S1
nuclease protection assay, Northern blotting, and PCR based techniques, we
demonstrated that the ATPase 6 region of the porcine mitochondrial genome is
transcribed as co-existing, stable sense and antisense RNAs. Furthermore, we
identified sense and antisense transcripts from this region consisting of
inversely assembled fragments joined together at a direct repeat of 7
nucleotides. Our results suggest that transcription and post-transcriptional
processing of mitochondrial RNAs are much more complex than presently thought.
PMID- 10777700
TI - Silkworm hemolymph inhibits baculovirus-induced insect cell apoptosis.
AB - The effect of silkworm hemolymph on baculovirus-induced insect cell apoptosis was
investigated. The addition of silkworm hemolymph into the culture medium either
before or during the baculovirus infection increased the host cell longevity;
however, its addition after the infection was less effective. This can be
explained by the higher transfer rate of silkworm hemolymph which is caused by
endocytosis during the virus internalization step. The delayed cell death due to
silkworm hemolymph was not caused by an inhibition of the virus attachment and
internalization steps. The apoptosis was analyzed using DNA fragmentation and
TUNEL assays, and the resulting data confirm that silkworm hemolymph inhibits
baculovirus-induced insect cell apoptosis.
PMID- 10777699
TI - Monoamine oxidase B induces ERK-dependent cell mitogenesis by hydrogen peroxide
generation.
AB - The mitochondrial enzyme monoamine oxidase (MAO) A and B catalyze the oxidative
deamination of various endogenous and exogenous biogenic amines. In the present
study, we used human embryonic kidney 293 (HEK 293) cells stably transfected with
human MAO-B cDNA to investigate the potential role of hydrogen peroxide
(H(2)O(2)) produced by MAO-B isoform as an intracellular messenger involved in
regulation of cell signaling and function. The MAO substrate tyramine induced
tyrosine phosphorylation of Shc, ERK activation, and an increase in DNA synthesis
in HEK 293 expressing MAO-B, but not in wild type HEK 293 cells, which do not
express MAO. Tyramine effects were fully prevented by cell pretreatment with the
MAO inhibitor pargyline or the antioxidant N-acetylcysteine. These results show
that MAO-B induces MAPK/ERK activation and cell mitogenesis through H(2)O(2)
production.
PMID- 10777701
TI - Animal and plant members of a gene family with similarity to alkaloid
synthesizing enzymes.
AB - Here we describe novel members of a gene family which have similarity to
strictosidine synthase (SS), one of the key enzymes in the production of
monoterpene indole alkaloids. In addition to the first animal member of the
family described previously (Drosophila hemomucin), a second Drosophila member
has been identified, which appears to differ in subcellular distribution from
hemomucin. In Arabidopsis, SS-like genes form a multigene family, compatible with
a possible function as antifeedants and antibacterial compounds. In
Caenorhabditis, two members have been identified and one member each in mouse and
human. Interestingly, the human SS-like gene is strongly expressed in the brain,
the very organ many of the indole alkaloids act upon.
PMID- 10777702
TI - Decreased gene expression of adrenomedullin receptor in mouse lungs during
sepsis.
AB - Plasma concentrations of adrenomedullin (AM) are markedly increased during
sepsis, but the role of AM has not been clarified. Coexpression of calcitonin
receptor-like receptor (CRLR) and receptor activity modifying protein (RAMP) 2 or
3 have been reported to form the adrenomedullin (AM) specific receptor. We
examined the expression of CRLR and RAMP1, 2, and 3 in several tissues from mice
in a sepsis model induced by lipopolysaccharide (LPS). High expression of CRLR
and RAMP2 mRNA was observed in lungs of normal mice, but it was markedly
decreased in endotoxemic mice. It is suggested that the abundant binding sites of
AM in lungs are formed by CRLR and RAMP2 in healthy subjects and that their
reduction should contribute to the increase of plasma AM concentrations during
sepsis. In contrast, LPS treatment markedly increased RAMP3 gene expression in
lungs, spleen, and thymus. It is revealed that the distributions of receptor or
binding sites of AM are changed in sepsis, and it is suggested that AM plays
distinct roles in the clinical course of this syndrome.
PMID- 10777703
TI - Mechanism of regulation of HGF/SF gene expression in fibroblasts by TGF-beta1.
AB - The effect of transforming growth factor beta 1 (TGF-beta1) on levels of
hepatocyte growth factor/scatter factor (HGF/SF) gene transcripts was
investigated in the human lung embryonic fibroblast cell line, MRC-5. TGF-beta1
markedly reduced the expression of the 6. 0-kb and 3.0-kb HGF/SF mRNA, which
encode full-length HGF/SF, but it had little effect on the expression of the
alternatively spliced 1. 5-kb mRNA, which encodes NK2, a competitive HGF/SF
antagonist. Using actinomycin D to block RNA synthesis, it was observed that TGF
beta1 had little effect on the stability of the 1.5-kb NK2 mRNA but increased the
rate of degradation of the 6.0- and 3.0-kb HGF/SF mRNA transcripts by a mechanism
that was dependent on new protein synthesis. TGF-beta1 minimally increased rather
than reduced HGF/SF promoter activity in cells transiently transfected with
chloramphenicol acetyltransferase (CAT) reporter genes driven by HGF/SF gene 5'
flanking sequences. In MRC-5 cells, TGF-beta1 modulates HGF/SF gene transcripts
at the posttranscriptional level in order to favour expression of the 1.5-kb mRNA
that encodes the truncated protein NK2.
PMID- 10777704
TI - The Pro12Ala polymorphism in PPAR gamma2 may confer resistance to type 2
diabetes.
AB - Peroxisome proliferator-activated receptor gamma (PPARgamma) has been implicated
in adipocyte differentiation. Recently it was reported that heterozygous
deficiency of PPARgamma led to the protection from high-fat diet-induced insulin
resistance in an animal model. A Pro12Ala polymorphism has been detected in the
human PPARgamma2 gene. Since this amino acid substitution may cause a reduction
in the transcriptional activity of PPARgamma, this polymorphism may be associated
with decreased insulin resistance and decreased risk of type 2 diabetes. To
investigate this hypothesis, we performed a case-control study of the Pro12Ala
PPARgamma2 polymorphism in Japanese diabetic and non-diabetic subjects. The
frequency of Ala12 was significantly lower in the diabetic group. In an
overweight or obese group, subjects with Ala12 were more insulin sensitive than
those without. These results suggest that the PPARgamma is a thrifty gene and
that the Pro12Ala PPARgamma2 polymorphism protects against type 2 diabetes in the
Japanese.
PMID- 10777705
TI - Enhancement of S-nitrosylation in glycosylated hemoglobin.
AB - In this study, we report a novel differential nitric oxide interaction with
nonglycosylated and glycosylated hemoglobin. After in vitro incubation of
hemoglobin with S-nitroso N-acetyl penicillamine (SNAP), S-nitrosoglutathione, or
S-nitrosocysteine, S-nitrosylation was significantly higher in human glycosylated
hemoglobin purified from diabetic subjects compared to nondiabetic controls.
Inversely, spontaneous decomposition was significantly lower for S
nitrosohemoglobin obtained from glycosylated hemoglobin. Bidimensional
isoelectric focusing of hemoglobins incubated in vitro with SNAP also revealed a
greater interaction of nitric oxide with glycosylated hemoglobin. In addition, a
significantly higher level of S-nitrosohemoglobin was found in erythrocyte
lysates from streptozotocin-induced diabetic rats compared to control rats. We
suggest that highly glycosylated hemoglobin in diabetic subjects may favor S
nitrosylation, which may in turn impair vascular function, and participate in
diabetic microangiopathy.
PMID- 10777706
TI - In vivo metabolic imaging of cardiac bioenergetics in transgenic mice.
AB - Recent advances in transgenic technology have made the mouse a particularly
interesting small animal in cardiovascular research. Increasingly sophisticated
experimental methods and tools are needed for detailed characterization of
cardiovascular physiology and biochemistry in the mice. The objective of this
study was to develop a method for noninvasive evaluation of cardiac energy
metabolism in the mouse. Cardiac gated (31)P magnetic resonance spectroscopy
using Image Selected in Vivo Spectroscopy (ISIS) method was applied in old mice
overexpressing bovine growth hormone (bGH) (n = 5) and control mice (n = 5). The
localized volumes of interest were 128 and 112 microL, respectively.
Phosphocreatine-to-ATP ratio was 1.5 +/- 0.13 in the bGH mice and 2.1 +/- 0.04 in
the control group (P < 0.01). The study demonstrates the feasibility of
application of volume-selective (31)P MRS for evaluation of cardiac energy
metabolism in the mouse under maintained physiological conditions.
PMID- 10777707
TI - Chitinous materials inhibit nitric oxide production by activated RAW 264.7
macrophages.
AB - Chitinous materials have been studied in wound healing and artificial skin
substitutes for many years. Nitric oxide (NO) has been shown to contribute to
cytotoxicity in cell proliferation during inflammation of wound healing. In this
study, we examined the effect of chitin and its derivatives on NO production by
activated RAW 264.7 macrophages. Chitin and chitosan showed a significantly
inhibitory effect on NO production by the activated macrophages. Hexa-N
acetylchitohexaose and penta-N-acetylchitopentaose also inhibited NO production
but with less potency. However, N-acetylchitotetraose, -triose, -biose, and
monomer of chitin, N-acetylglucosamine and glucosamine had little effect on NO
production by the activated cells. These results suggest that the promotive
effect of chitinous material on wound healing be related, at least partly, to
inhibit NO production by the activated macrophages.
PMID- 10777708
TI - Drug-induced desensitization of insulinotropic actions of sulfonylureas.
AB - K(ATP)-channel-dependent and K(ATP)-channel-independent insulin-releasing actions
of the sulfonylurea, tolbutamide, were examined in the clonal BRIN-BD11 cell
line. Tolbutamide stimulated insulin release at both nonstimulatory (1.1 mM) and
stimulatory (16. 7 mM) glucose. Under depolarizing conditions (16.7 mM glucose
plus 30 mM KCl) tolbutamide evoked a stepwise K(ATP) channel-independent
insulinotropic response. Culture (18 h) with tolbutamide or the guanidine
derivative BTS 67 582 (100 microM) markedly reduced (P < 0. 001) subsequent
responsiveness to acute challenge with tolbutamide, glibenclamide, and BTS 67 582
but not the imidazoline drug, efaroxan. Conversely, 18 h culture with efaroxan
reduced (P < 0.001) subsequent insulinotropic effects of efaroxan but not that of
tolbutamide, glibenclamide, or BTS 67 582. Culture (18 h) with tolbutamide
reduced the K(ATP) channel-independent actions of both tolbutamide and
glibenclamide. Whereas culture with efaroxan exerted no effect on the K(ATP)
channel-independent actions of sulfonylureas, BTS 67 582 abolished the response
of tolbutamide and inhibited that of glibenclamide. These data demonstrate that
prolonged exposure to tolbutamide desensitizes both K(ATP)-channel-dependent and
independent insulin-secretory actions of sulfonylureas, indicating synergistic
pathways mediated by common sulfonylurea binding site(s).
PMID- 10777709
TI - Light chain determines the binding property of human anti-dsDNA IgG
autoantibodies.
AB - We have previously prepared human anti-double-stranded (ds) DNA IgG Fab clones
using phage-display technology. Nucleotide sequence analysis of genes of
immunoglobulin (Ig) heavy and light chain variable regions in these Fab clones
suggested that the DNA-binding activity of the clones depended on light chain
usage. To confirm the role of the light chain in antibody binding to DNA, we
constructed in the present study's new recombined Fab clones by heavy and light
chain shuffling between the original anti-dsDNA Fab clones. Clones constructed by
pairing Fdgamma fragments with the light chain from a high DNA-binding clone
showed high DNA-binding activities, whereas other constructed clones using light
chains from low DNA-binding clones showed low DNA-binding activities. Our results
indicate that light chains in anti-dsDNA antibodies can determine the DNA-binding
activity of the antibodies. Ig chain shuffling of phage-display antibodies may be
useful for investigating the molecular mechanisms for antigen-antibody binding of
human autoantibodies.
PMID- 10777710
TI - ADP modulates the dynamic behavior of the glycolytic pathway of Escherichia coli.
AB - A mathematical model that includes biochemical interactions among the PTS system,
phosphofructokinase (PFK), and pyruvate kinase (PK) is used to evaluate the
dynamic behavior of the glycolytic pathway of Escherichia coli under steady-state
conditions. The influence of ADP, phosphoenolpyruvate (PEP), and fructose-6
phosphate (F6P) on the dynamic regulation of this pathway is also analyzed. The
model shows that the dynamic behavior of the system is affected significantly
depending on whether ADP, PEP, or F6P is considered constant a steady state.
Sustained oscillations are observed only when dADP/dt not equal 0 and completely
suppressed if dADP/dt = 0 at any steady-state value. However, when PEP or F6P is
constant, the system evolves toward the formation of stable limit cycles with
periods ranging from 0.2 min to hours.
PMID- 10777711
TI - Zinc-deficient rat embryos have increased caspase 3-like activity and apoptosis.
AB - Caspase activity is a hallmark of apoptosis. Given that maternal zinc (Zn)
deficiency results in apoptosis in the rat embryo, we assessed caspase activity
in Zn-deficient embryos. Mid-gestation rat embryos were collected from dams fed
either a Zn-deficient (0.5 Zn/g) diet ad libitum, or a Zn-adequate (25 microg
Zn/g) diet ad libitum or pair fed to dams fed the Zn-deficient diet. Embryos from
dams fed the Zn-adequate diet had a normal level of cell death, while embryos
from the dams fed the Zn-deficient diet had either increased or normal levels of
cell death. Zn-deficient embryos displaying increased cell death had increased
caspase activity. Embryos with normal levels of cell death, regardless of
maternal diet, had similar caspase activities. Thus, Zn-deficiency-induced
apoptosis in vivo is associated with increased caspase activity.
PMID- 10777712
TI - The differential expression of apoptosis factors in the alveolar epithelium is
redox sensitive and requires NF-kappaB (RelA)-selective targeting.
AB - Fetal alveolar type II (fATII) epithelial cells were used to evaluate the role of
signaling factors involved in oxidative stress-induced programmed cell death
(PCD; apoptosis). Bcl-2, an antiapoptotic proto-oncogene, showed maximum
abundance in hypoxia and mild reoxygenation, but declined thereafter. The Bcl-2
counterpart, Bax, which promotes PCD, displayed an increasing logarithmic profile
with ascending DeltapO(2) regimen, such that the ratio of Bcl-2/Bax decreased as
pO(2) increased. The expression of p53, a cell cycle regulator, paralleled Bax
abundance. Pretreatment of fATII cells with l-buthionine-(S,R)-sulfoximine, an
irreversible inhibitor of gamma-glutamylcysteine synthetase, the rate-limiting
enzyme in the biosynthesis of glutathione (GSH), enhanced Bax and p53 expression
over Bcl-2. The GSH analogue, gamma-glutamylcysteinyl-ethyl ester, down-regulated
Bax/p53 abundance but restored that of Bcl-2, thereby increasing Bcl-2/Bax. The
antioxidant and GSH precursor N-acetyl-l-cysteine favored Bcl-2 at the expense of
Bax/p53, whereas pyrrolidine dithiocarbamate induced Bax against Bcl-2, with mild
effect on p53. Sulfasalazine, a potent and specific inhibitor of NF-kappaB,
induced Bax at the expense of Bcl-2, in a p53-dependent manner. We conclude that
the differential expression of signaling factors involved in PCD in the alveolar
epithelium is redox-sensitive and mediated, at least in part, by a negative
feedback mechanism transduced by NF-kappaB.
PMID- 10777713
TI - Direct evidence for decreased sialylation and galactosylation of human serum IgA1
Fc O-glycosylated hinge peptides in IgA nephropathy by mass spectrometry.
AB - Human serum immunoglobulin IgA1 is produced in bone marrow and interacts with
specific cellular receptors that mediate biological events. In this study, we
have analyzed the detailed glycoform structure of the human serum IgA1 Fc O
glycosylated hinge region by electrospray ionization liquid mass spectrometry.
The IgA1 fragments containing the hinge glycopeptide were separated from 4 IgA
nephropathy patient (IgAN) pooled sera, 10 non-IgAN pooled sera with other
primary glomerulonephritides, and 5 healthy control subject pooled sera by
trypsin treatment and Jacalin affinity chromatography. The molecular weights of
IgA1 hinge glycopeptide were estimated using mass spectrometry, and 13 sialo and
8 asialo glycopeptide groups were identified. The results obtained clearly showed
a decrease of GalNAc, Gal, and sialic acid in IgAN compared with non-IgAN and
normal controls, and those strongly suggested the possibility that the decreased
galactosylation and sialylation of the IgA1 hinge result in its glomerular
deposition in IgAN.
PMID- 10777714
TI - Genomewide search in Canadian families with inflammatory bowel disease reveals
two novel susceptibility loci.
AB - The chronic inflammatory bowel diseases (IBDs)-Crohn disease (CD) and ulcerative
colitis (UC)-are idiopathic, inflammatory disorders of the gastrointestinal
tract. These conditions have a peak incidence in early adulthood and a combined
prevalence of approximately 100-200/100,000. Although the etiology of IBD is
multifactorial, a significant genetic contribution to disease susceptibility is
implied by epidemiological data revealing a sibling risk of approximately 35-fold
for CD and approximately 15-fold for UC. To elucidate the genetic basis for these
disorders, we undertook a genomewide scan in 158 Canadian sib-pair families and
identified three regions of suggestive linkage (3p, 5q31-33, and 6p) and one
region of significant linkage to 19p13 (LOD score 4.6). Higher-density mapping in
the 5q31-q33 region revealed a locus of genomewide significance (LOD score 3.9)
that contributes to CD susceptibility in families with early-onset disease. Both
of these genomic regions contain numerous genes that are important to the immune
and inflammatory systems and that provide good targets for future candidate-gene
studies.
PMID- 10777715
TI - Molecular cytogenetic analysis of eight inversion duplications of human
chromosome 13q that each contain a neocentromere.
AB - Neocentromeres are fully functional centromeres that have arisen in previously
noncentromeric chromosomal locations on rearranged chromosomes. The formation of
neocentromeres results in the mitotic stability of chromosomal fragments that do
not contain endogenous centromeres and that would normally be lost. Here we
describe a unique collection of eight independent patient-derived cell lines,
each of which contains a neocentromere on a supernumerary inversion duplication
of a portion of human chromosome 13q. Findings in these patients reveal insight
into the clinical manifestations associated with polysomy for portions of
chromosome 13q. The results of FISH and immunofluorescent analysis of the
neocentromeres in these chromosomes confirm the lack of alpha-satellite DNA and
the presence of CENtromere proteins (CENP)-C, -E, and hMAD2. The positions of the
inversion breakpoints in these chromosomes have been placed onto the physical map
of chromosome 13, by means of FISH mapping with cosmid probes. These cell lines
define, within chromosome 13q, at least three distinct locations where
neocentromeres have formed, with five independent neocentromeres in band 13q32,
two in band 13q21, and one in band 13q31. The results of examination of the set
of 40 neocentromere-containing chromosomes that have thus far been described,
including the 8 neocentromere-containing chromosomes from chromosome 13q that are
described in the present study, suggest that chromosome 13q has an increased
propensity for neocentromere formation, relative to some other human chromosomes.
These neocentromeres will provide the means for testing hypotheses about sequence
requirements for human centromere formation.
PMID- 10777717
TI - A novel locus (DFNA23) for prelingual autosomal dominant nonsyndromic hearing
loss maps to 14q21-q22 in a Swiss German kindred.
AB - DFNA23, a novel locus for autosomal dominant nonsyndromic hearing loss, was
identified in a Swiss German kindred. DNA samples were obtained from 22 family
members in three generations: 10 with hearing impairment caused by the DFNA23
locus, 8 unaffected offspring, and 4 spouses of hearing-impaired pedigree
members. In this kindred, the hearing-impaired family members have prelingual
bilateral symmetrical hearing loss. All audiograms from hearing-impaired
individuals displayed sloping curves, with hearing ability ranging from normal
hearing to mild hearing loss in low frequencies, normal hearing to profound
hearing loss in mid frequencies, and moderate to profound hearing loss in high
frequencies. A conductive component existed for 50% of the hearing-impaired
family members. The majority of the hearing-impaired family members did not
display progression of hearing loss. The DFNA23 locus maps to 14q21-q22. Linkage
analysis was carried out under a fully penetrant autosomal dominant mode of
inheritance with no phenocopies. A maximum multipoint LOD score of 5.1 occurred
at Marker D14S290. The 3.0-LOD unit support interval is 9.4 cM and ranged from
marker D14S980 to marker D14S1046.
PMID- 10777716
TI - COL5A1 haploinsufficiency is a common molecular mechanism underlying the
classical form of EDS.
AB - We have identified haploinsufficiency of the COL5A1 gene that encodes the
proalpha1(V) chain of type V collagen in the classical form of the Ehlers-Danlos
syndrome (EDS), a heritable connective-tissue disorder that severely alters the
collagen-fibrillar structure of the dermis, joints, eyes, and blood vessels.
Eight of 28 probands with classical EDS who were heterozygous for expressed
polymorphisms in COL5A1 showed complete or nearly complete loss of expression of
one COL5A1 allele. Reduced levels of proalpha1(V) mRNA relative to the levels of
another type V collagen mRNA, proalpha2(V), were also observed in the cultured
fibroblasts from EDS probands. Products of the two COL5A1 alleles were
approximately equal after the addition of cycloheximide to the fibroblast
cultures. After harvesting of mRNAs from cycloheximide-treated cultured
fibroblasts, heteroduplex analysis of overlapping reverse transcriptase-PCR
segments spanning the complete proalpha1(V) cDNA showed anomalies in four of the
eight probands that led to identification of causative mutations, and, in the
remaining four probands, targeting of CGA-->TGA mutations in genomic DNA revealed
a premature stop at codon in one of them. We estimate that approximately one
third of individuals with classical EDS have mutations of COL5A1 that result in
haploinsufficiency. These findings indicate that the normal formation of the
heterotypic collagen fibrils that contain types I, III, and V collagen requires
the expression of both COL5A1 alleles.
PMID- 10777719
TI - Self-assembly in vivo.
PMID- 10777718
TI - Gaucher disease: the origins of the Ashkenazi Jewish N370S and 84GG acid beta
glucosidase mutations.
AB - Type 1 Gaucher disease (GD), a non-neuronopathic lysosomal storage disorder,
results from the deficient activity of acid beta-glucosidase (GBA). Type 1
disease is panethnic but is more prevalent in individuals of Ashkenazi Jewish
(AJ) descent. Of the causative GBA mutations, N370S is particularly frequent in
the AJ population, (q approximately .03), whereas the 84GG insertion (q
approximately .003) occurs exclusively in the Ashkenazim. To investigate the
genetic history of these mutations in the AJ population, short tandem repeat
(STR) markers were used to map a 9.3-cM region containing the GBA locus and to
genotype 261 AJ N370S chromosomes, 60 European non-Jewish N370S chromosomes, and
62 AJ 84GG chromosomes. A highly conserved haplotype at four markers flanking GBA
(PKLR, D1S1595, D1S2721, and D1S2777) was observed on both the AJ chromosomes and
the non-Jewish N370S chromosomes, suggesting the occurrence of a founder common
to both populations. Of note, the presence of different divergent haplotypes
suggested the occurrence of de novo, recurrent N370S mutations. In contrast, a
different conserved haplotype at these markers was identified on the 84GG
chromosomes, which was unique to the AJ population. On the basis of the linkage
disequilibrium (LD) delta values, the non-Jewish European N370S chromosomes had
greater haplotype diversity and less LD at the markers flanking the conserved
haplotype than did the AJ N370S chromosomes. This finding is consistent with the
presence of the N370S mutation in the non-Jewish European population prior to the
founding of the AJ population. Coalescence analyses for the N370S and 84GG
mutations estimated similar coalescence times, of 48 and 55.5 generations ago,
respectively. The results of these studies are consistent with a significant
bottleneck occurring in the AJ population during the first millennium, when the
population became established in Europe.
PMID- 10777720
TI - Molecular dynamics simulations of protein-tyrosine phosphatase 1B. II. substrate
enzyme interactions and dynamics.
AB - Molecular dynamics simulations of protein tyrosine phosphatase 1B (PTP1B)
complexed with the phosphorylated peptide substrate DADEpYL and the free
substrate have been conducted to investigate 1) the physical forces involved in
substrate-protein interactions, 2) the importance of enzyme and substrate
flexibility for binding, 3) the electrostatic properties of the enzyme, and 4)
the contribution from solvation. The simulations were performed for 1 ns, using
explicit water molecules. The last 700 ps of the trajectories was used for
analysis determining enthalpic and entropic contributions to substrate binding.
Based on essential dynamics analysis of the PTP1B/DADEpYL trajectory, it is shown
that internal motions in the binding pocket occur in a subspace of only a few
degrees of freedom. In particular, relatively large flexibilities are observed
along several eigenvectors in the segments: Arg(24)-Ser(28), Pro(38)-Arg(47), and
Glu(115)-Gly(117). These motions are correlated to the C- and N-terminal motions
of the substrate. Relatively small fluctuations are observed in the region of the
consensus active site motif (H/V)CX(5)R(S/T) and in the region of the WPD loop,
which contains the general acid for catalysis. Analysis of the individual enzyme
substrate interaction energies revealed that mainly electrostatic forces
contribute to binding. Indeed, calculation of the electrostatic field of the
enzyme reveals that only the field surrounding the binding pocket is positive,
while the remaining protein surface is characterized by a predominantly negative
electrostatic field. This positive electrostatic field attracts negatively
charged substrates and could explain the experimentally observed preference of
PTP1B for negatively charged substrates like the DADEpYL peptide.
PMID- 10777721
TI - The probability of quantal secretion near a single calcium channel of an active
zone.
AB - A Monte Carlo analysis has been made of calcium dynamics and quantal secretion at
microdomains in which the calcium reaches very high concentrations over distances
of <50 nm from a channel and for which calcium dynamics are dominated by
diffusion. The kinetics of calcium ions in microdomains due to either the
spontaneous or evoked opening of a calcium channel, both of which are stochastic
events, are described in the presence of endogenous fixed and mobile buffers.
Fluctuations in the number of calcium ions within 50 nm of a channel are
considerable, with the standard deviation about half the mean. Within 10 nm of a
channel these numbers of ions can give rise to calcium concentrations of the
order of 100 microM. The temporal changes in free calcium and calcium bound to
different affinity indicators in the volume of an entire varicosity or bouton
following the opening of a single channel are also determined. A Monte Carlo
analysis is also presented of how the dynamics of calcium ions at active zones,
after the arrival of an action potential and the stochastic opening of a calcium
channel, determine the probability of exocytosis from docked vesicles near the
channel. The synaptic vesicles in active zones are found docked in a complex with
their calcium-sensor associated proteins and a voltage-sensitive calcium channel,
forming a secretory unit. The probability of quantal secretion from an isolated
secretory unit has been determined for different distances of an open calcium
channel from the calcium sensor within an individual unit: a threefold decrease
in the probability of secretion of a quantum occurs with a doubling of the
distance from 25 to 50 nm. The Monte Carlo analysis also shows that the
probability of secretion of a quantum is most sensitive to the size of the single
channel current compared with its sensitivity to either the binding rates of the
sites on the calcium-sensor protein or to the number of these sites that must
bind a calcium ion to trigger exocytosis of a vesicle.
PMID- 10777722
TI - The probability of quantal secretion within an array of calcium channels of an
active zone.
AB - A Monte Carlo analysis has been made of calcium dynamics in submembranous domains
of active zones in which the calcium contributed by the opening of many channels
is pooled. The kinetics of calcium ions in these domains has been determined
using simulations for channels arranged in different geometries, according to the
active zone under consideration: rectangular grids for varicosities and boutons
and lines for motor-nerve terminals. The effects of endogenous fixed and mobile
buffers on the two-dimensional distribution of free calcium ions at these active
zones are then given, together with the extent to which these are perturbed and
can be detected with different affinity calcium indicators when the calcium
channels open stochastically under an action potential. A Monte Carlo analysis of
how the dynamics of calcium ions in the submembranous domains determines the
probability of exocytosis from docked vesicles is also presented. The spatial
distribution of exocytosis from rectangular arrays of secretory units is such
that exocytosis is largely excluded from the edges of the array, due to the
effects of endogenous buffers. There is a steeper than linear increase in quantal
release with an increase in the number of secretory units in the array,
indicating that there is not just a local interaction between secretory units.
Conditioning action potentials promote an increase in quantal release by a
subsequent action potential primarily by depleting the fixed and mobile buffers
in the center of the array. In the case of two parallel lines of secretory units
exocytosis is random, and diffusion, together with the endogenous calcium
buffers, ensures that the secretory units only interact over relatively short
distances. As a consequence of this and in contrast to the case of the
rectangular array, there is a linear relationship between the extent of quantal
secretion from these zones and their length, for lengths greater than a critical
value. This Monte Carlo analysis successfully predicts the relationship between
the size and geometry of active zones and the probability of quantal secretion at
these, the existence of quantal versus multiquantal release at different active
zones, and the origins of the F1 phase of facilitation in synapses possessing
different active zone geometries.
PMID- 10777723
TI - Dynamics of fusion pores connecting membranes of different tensions.
AB - The energetics underlying the expansion of fusion pores connecting biological or
lipid bilayer membranes is elucidated. The energetics necessary to deform
membranes as the pore enlarges, in some combination with the action of the fusion
proteins, must determine pore growth. The dynamics of pore growth is considered
for the case of two homogeneous fusing membranes under different tensions. It is
rigorously shown that pore growth can be quantitatively described by treating the
pore as a quasiparticle that moves in a medium with a viscosity determined by
that of the membranes. Motion is subject to tension, bending, and viscous forces.
Pore dynamics and lipid flow through the pore were calculated using Lagrange's
equations, with dissipation caused by intra- and intermonolayer friction. These
calculations show that the energy barrier that restrains pore enlargement depends
only on the sum of the tensions; a difference in tension between the fusing
membranes is irrelevant. In contrast, lipid flux through the fusion pore depends
on the tension difference but is independent of the sum. Thus pore growth is not
affected by tension-driven lipid flux from one membrane to the other. The
calculations of the present study explain how increases in tension through
osmotic swelling of vesicles cause enlargement of pores between the vesicles and
planar bilayer membranes. In a similar fashion, swelling of secretory granules
after fusion in biological systems could promote pore enlargement during
exocytosis. The calculations also show that pore expansion can be caused by pore
lengthening; lengthening may be facilitated by fusion proteins.
PMID- 10777724
TI - Lateral diffusion of membrane proteins in the presence of static and dynamic
corrals: suggestions for appropriate observables.
AB - We consider the possibility of inferring the nature of cytoskeletal interaction
with transmembrane proteins via optical experiments such as single-particle
tracking (SPT) and near-field scanning optical microscopy (NSOM). In particular,
we demonstrate that it may be possible to differentiate between static and
dynamic barriers to diffusion by examining the time-dependent variance and higher
moments of protein population inside cytoskeletal "corrals." Simulations modeling
Band 3 diffusion on the surface of erythrocytes provide a concrete demonstration
that these statistical tools might prove useful in the study of biological
systems.
PMID- 10777725
TI - Cell property determination from the acoustic microscope generated voltage versus
frequency curves.
AB - Among the methods for the determination of mechanical properties of living cells
acoustic microscopy provides some extraordinary advantages. It is relatively
fast, of excellent spatial resolution and of minimal invasiveness. Sound velocity
is a measure of the stiffness or Young's modulus of the cell. Attenuation of
cytoplasm is a measure of supramolecular interactions. These parameters are of
crucial interest for studies of cell motility, volume regulations and to
establish the functional role of the various elements of the cytoskeleton. Using
a phase and amplitude sensitive modulation of a scanning acoustic microscope
(Hillman et al., 1994, J. Alloys Compounds. 211/212:625-627) longitudinal wave
speed, attenuation and thickness profile of a biological cell are obtained from
the voltage versus frequency or V(f) curves. A series of pictures, for instance
in the frequency range 980-1100 MHz with an increment of 20 MHz, allows the
experimental generation of V(f) curves for each pixel while keeping the lens
specimen distance unchanged. Both amplitude and phase values of the V(f) curves
are used for obtaining the cell properties and the cell thickness profile. The
theoretical analysis shows that the thin liquid layer, between the cell and the
substrate, has a strong influence on the reflection coefficient and should not be
ignored during the analysis. Cell properties, cell profile and the thickness of
the thin liquid layer are obtained from the V(f) curves by the simplex inversion
algorithm. The main advantages of this new method are that imaging can be done
near the focal plane, therefore an optimal signal to noise ratio is achieved, no
interference with Rayleigh waves occurs, and the method requires only an
approximate estimate of the material properties of the solid substratum where the
cells are growing on.
PMID- 10777726
TI - Solvent-isotope and pH effects on flagellar rotation in Escherichia coli.
AB - We studied changes in speed of the flagellar rotary motor of Escherichia coli
when tethered cells or cells carrying small latex spheres on flagellar stubs were
shifted from H(2)O to D(2)O or subjected to changes in external pH. In the high
torque, low-speed regime, solvent isotope effects were found to be small; in the
low-torque, high-speed regime, they were large. The boundaries between these
regimes were close to those found earlier in measurements of the torque-speed
relationship of the flagellar rotary motor (, Biophys. J. 65:2201-2216;, Biophys.
J., 78:1036-1041). This observation provides direct evidence that the decline in
torque at high speed is due primarily to limits in rates of proton transfer.
However, variations of speed (and torque) with shifts of external pH (from 4.7 to
8.8) were small for both regimes. Therefore, rates of proton transfer are not
very dependent on external pH.
PMID- 10777727
TI - Three-dimensional motion of the organ of Corti.
AB - The vibration of the organ of Corti, a three-dimensional micromechanical
structure that incorporates the sensory cells of the hearing organ, was measured
in three mutually orthogonal directions. This was achieved by coupling the light
of a laser Doppler vibrometer into the side arm of an epifluorescence microscope
to measure velocity along the optical axis of the microscope, called the
transversal direction. Displacements were measured in the plane orthogonal to the
transverse direction with a differential photodiode mounted on the microscope in
the focal plane. Vibration responses were measured in the fourth turn of a
temporal-bone preparation of the guinea-pig cochlea. Responses were corrected for
a "fast" wave component caused by the presence of the hole in the cochlear wall,
made to view the structures. The frequency responses of the basilar membrane and
the reticular lamina were similar, with little phase differences between the
vibration components. Their motion was rectilinear and vertical to the surface of
their membranes. The organ of Corti rotated about a point near the edge of the
inner limbus. A second vibration mode was detected in the motion of the tectorial
membrane. This vibration mode was directed parallel to the reticular lamina and
became apparent for frequencies above approximately 0.5 oct below the
characteristic frequency. This radial vibration mode presumably controls the
shearing action of the hair bundles of the outer hair cells.
PMID- 10777728
TI - A bimodal pattern of InsP(3)-evoked elementary Ca(2+) signals in pancreatic
acinar cells.
AB - InsP(3)-evoked elementary Ca(2+) release events have been postulated to play a
role in providing the building blocks of larger Ca(2+) signals. In pancreatic
acinar cells, low concentrations of acetylcholine or the injection of low
concentrations of InsP(3) elicit a train of spatially localized Ca(2+) spikes. In
this study we have quantified these responses and compared the Ca(2+) signals to
the elementary events shown in Xenopus oocytes. The results demonstrate, at the
same concentrations of InsP(3), Ca(2+) signals consisting of one population of
small transient Ca(2+) release events and a second distinct population of larger
Ca(2+) spikes. The signal mass amplitudes of both types of events are within the
range of amplitudes for the elementary events in Xenopus oocytes. However, the
bimodal Ca(2+) distribution of Ca(2+) responses we observe is not consistent with
the continuum of event sizes seen in Xenopus. We conclude that the two types of
InsP(3)-dependent events in acinar cells are both elementary Ca(2+) signals,
which are independent of one another. Our data indicate a complexity to the
organization of the Ca(2+) release apparatus in acinar cells, which might result
from the presence of multiple InsP(3) receptor isoforms, and is likely to be
important in the physiology of these cells.
PMID- 10777729
TI - Structural basis for ligand selectivity of heteromeric olfactory cyclic
nucleotide-gated channels.
AB - In vertebrate olfactory receptors, cAMP produced by odorants opens cyclic
nucleotide-gated (CNG) channels, which allow Ca(2+) entry and depolarization of
the cell. These CNG channels are composed of alpha subunits and at least two
types of beta subunits that are required for increased cAMP selectivity. We
studied the molecular basis for the altered cAMP selectivity produced by one of
the beta subunits (CNG5, CNCalpha4, OCNC2) using cloned rat olfactory CNG
channels expressed in Xenopus oocytes. Compared with alpha subunit homomultimers
(alpha channels), channels composed of alpha and beta subunits (alpha+beta
channels) were half-activated (K(1/2)) by eightfold less cAMP and fivefold less
cIMP, but similar concentrations of cGMP. The K(1/2) values for heteromultimers
of the alpha subunit and a chimeric beta subunit with the alpha subunit cyclic
nucleotide-binding region (CNBR) (alpha+beta-CNBRalpha channels) were restored to
near the values for alpha channels. Furthermore, a single residue in the CNBR
could account for the altered ligand selectivity. Mutation of the methionine
residue at position 475 in the beta subunit to a glutamic acid as in the alpha
subunit (beta-M475E) reverted the K(1/2,cAMP)/K(1/2,cGMP) and K(1/2,
cIMP)/K(1/2,cGMP) ratios of alpha+beta-M475E channels to be very similar to those
of alpha channels. In addition, comparison of alpha+beta-CNBRalpha channels with
alpha+beta-M475E channels suggests that the CNBR of the beta subunit contains
amino acid differences at positions other than 475 that produce an increase in
the apparent affinity for each ligand. Like the wild-type beta subunit, the
chimeric beta/alpha subunits conferred a shallow slope to the dose-response
curves, increased voltage dependence, and caused desensitization. In addition, as
for alpha+beta channels, block of alpha+betaCNBRalpha channels by internal Mg(2+)
was not steeply voltage-dependent (zdelta approximately 1e(-)) as compared to
block of alpha channels (zdelta 2.7e(-)). Thus, the ligand-independent effects
localize outside of the CNBR. We propose a molecular model to explain how the
beta subunit alters ligand selectivity of the heteromeric channels.
PMID- 10777730
TI - Mutating three residues in the bovine rod cyclic nucleotide-activated channel can
switch a nucleotide from inactive to active.
AB - Cyclic nucleotide-gated (CNG) channels, which were initially studied in retina
and olfactory neurons, are activated by cytoplasmic cGMP or cAMP. Detailed
comparisons of nucleotide-activated currents using nucleotide analogs and
mutagenesis revealed channel-specific residues in the nucleotide-binding domain
that regulate the binding and channel-activation properties. Of particular
interest are N(1)-oxide cAMP, which does not activate bovine rod channels, and Rp
cGMPS, which activates bovine rod, but not catfish, olfactory channels.
Previously, we showed that four residues coordinate the purine interactions in
the binding domain and that three of these residues vary in the alpha subunits of
the bovine rod, catfish, and rat olfactory channels. Here we show that both N(1)
oxide cAMP and Rp-cGMPS activate rat olfactory channels. A mutant of the bovine
rod alpha subunit, substituted with residues from the rat olfactory channel at
the three variable positions, was weakly activated by N(1)-oxide cAMP, and a
catfish olfactory-like bovine rod mutant lost activation by Rp-cGMPS. These
experiments underscore the functional importance of purine contacts with three
residues in the cyclic nucleotide-binding domain. Molecular models of nucleotide
analogs in the binding domains, constructed with AMMP, showed differences in the
purine contacts among the channels that might account for activation differences.
PMID- 10777731
TI - The kinetic and physical basis of K(ATP) channel gating: toward a unified
molecular understanding.
AB - K(ATP) channels can be formed from Kir6.2 subunits with or without SUR1. The open
state stability of K(ATP) channels can be increased or reduced by mutations
throughout the Kir6.2 subunit, and is increased by application of PIP(2) to the
cytoplasmic membrane. Increase of open-state stability is manifested as an
increase in the channel open probability in the absence of ATP (Po(zero)) and a
correlated decrease in sensitivity to inhibition by ATP. Single channel lifetime
analyses were performed on wild-type and I154C mutant channels expressed with,
and without, SUR1. Channel kinetics include a single, invariant, open duration;
an invariant, brief, closed duration; and longer closed events consisting of a
"mixture of exponentials," which are prolonged in ATP and shortened after PIP(2)
treatment. The steady-state and kinetic data cannot be accounted for by assuming
that ATP binds to the channel and causes a gate to close. Rather, we show that
they can be explained by models that assume the following regarding the gating
behavior: 1) the channel undergoes ATP-insensitive transitions from the open
state to a short closed state (C(f)) and to a longer-lived closed state (C(0));
2) the C(0) state is destabilized in the presence of SUR1; and 3) ATP can access
this C(0) state, stabilizing it and thereby inhibiting macroscopic currents. The
effect of PIP(2) and mutations that stabilize the open state is then to shift the
equilibrium of the "critical transition" from the open state to the ATP
accessible C(0) state toward the O state, reducing accessibility of the C(0)
state, and hence reducing ATP sensitivity.
PMID- 10777732
TI - Tests of continuum theories as models of ion channels. I. Poisson-Boltzmann
theory versus Brownian dynamics.
AB - Continuum theories of electrolytes are widely used to describe physical processes
in various biological systems. Although these are well-established theories in
macroscopic situations, it is not clear from the outset that they should work in
small systems whose dimensions are comparable to or smaller than the Debye
length. Here, we test the validity of the mean-field approximation in Poisson
Boltzmann theory by comparing its predictions with those of Brownian dynamics
simulations. For this purpose we use spherical and cylindrical boundaries and a
catenary shape similar to that of the acetylcholine receptor channel. The
interior region filled with electrolyte is assumed to have a high dielectric
constant, and the exterior region representing protein a low one. Comparisons of
the force on a test ion obtained with the two methods show that the shielding
effect due to counterions is overestimated in Poisson-Boltzmann theory when the
ion is within a Debye length of the boundary. As the ion gets closer to the
boundary, the discrepancy in force grows rapidly. The implication for membrane
channels, whose radii are typically smaller than the Debye length, is that
Poisson-Boltzmann theory cannot be used to obtain reliable estimates of the
electrostatic potential energy and force on an ion in the channel environment.
PMID- 10777733
TI - Tests of continuum theories as models of ion channels. II. Poisson-Nernst-Planck
theory versus brownian dynamics.
AB - We test the validity of the mean-field approximation in Poisson-Nernst-Planck
theory by contrasting its predictions with those of Brownian dynamics simulations
in schematic cylindrical channels and in a realistic potassium channel.
Equivalence of the two theories in bulk situations is demonstrated in a control
study. In simple cylindrical channels, considerable differences are found between
the two theories with regard to the concentration profiles in the channel and its
conductance properties. These differences are at a maximum in narrow channels
with a radius smaller than the Debye length and diminish with increasing radius.
Convergence occurs when the channel radius is over 2 Debye lengths. These tests
unequivocally demonstrate that the mean-field approximation in the Poisson-Nernst
Planck theory breaks down in narrow ion channels that have radii smaller than the
Debye length.
PMID- 10777734
TI - Electrostatic interaction between charybdotoxin and a tetrameric mutant of Shaker
K(+) channels.
AB - The scorpion toxin, Charybdotoxin (CTX), blocks homotetrameric, voltage-gated
K(+) channels by binding near the outer entrance to the pore in one of four
indistinguishable orientations. We have determined the pH-dependence of CTX block
of a tetrameric Shaker potassium channel with a single copy of a histidine
replacing the wild-type phenylalanine at position 425. We compared this pH
dependence with that from homotetrameric channels with four copies of the
mutation. We found that protonation of a single amino acid at position 425 had a
large effect on the affinity of the channel for CTX-much larger than expected if
only one of the four CTX binding orientations was disrupted. The pK(a) for the
H(+)-ion induced protection from CTX block indicates that the electrostatic
environment near position 425 is likely basic in nature, perhaps because of the
proximity of lysine 427. We also examined the pH-dependence of block of channels
with one and four copies of the histidine mutation by CTX containing neutralizing
mutations of four basic residues on the active face of the toxin. The results
suggested an orientation of CTX on the channel that places three of the
positively charged CTX residues very near three of the four Shaker 425 positions.
PMID- 10777735
TI - Action potential and contractility changes in [Na(+)](i) overloaded cardiac
myocytes: a simulation study.
AB - Sodium overload of cardiac cells can accompany various pathologies and induce
fatal cardiac arrhythmias. We investigate effects of elevated intracellular
sodium on the cardiac action potential (AP) and on intracellular calcium using
the Luo-Rudy model of a mammalian ventricular myocyte. The results are: 1) During
rapid pacing, AP duration (APD) shortens in two phases, a rapid phase without
Na(+) accumulation and a slower phase that depends on [Na(+)](i). 2) The rapid
APD shortening is due to incomplete deactivation (accumulation) of I(Ks). 3) The
slow phase is due to increased repolarizing currents I(NaK) and reverse-mode
I(NaCa), secondary to elevated [Na(+)](i). 4) Na(+)-overload slows the rate of AP
depolarization, allowing time for greater I(Ca(L)) activation; it also enhances
reverse-mode I(NaCa). The resulting increased Ca(2+) influx triggers a greater
[Ca(2+)](i) transient. 5) Reverse-mode I(NaCa) alone can trigger Ca(2+) release
in a voltage and [Na(+)](i)-dependent manner. 6) During I(NaK) block, Na(+) and
Ca(2+) accumulate and APD shortens due to enhanced reverse-mode I(NaCa);
contribution of I(K(Na)) to APD shortening is negligible. By slowing AP
depolarization (hence velocity) and shortening APD, Na(+)-overload acts to
enhance inducibility of reentrant arrhythmias. Shortened APD with elevated
[Ca(2+)](i) (secondary to Na(+)-overload) also predisposes the myocardium to
arrhythmogenic delayed afterdepolarizations.
PMID- 10777736
TI - Conformation and dynamics of melittin bound to magnetically oriented lipid
bilayers by solid-state (31)P and (13)C NMR spectroscopy.
AB - The conformation and dynamics of melittin bound to the
dimyristoylphosphatidylcholine (DMPC) bilayer and the magnetic orientation in the
lipid bilayer systems were investigated by solid-state (31)P and (13)C NMR
spectroscopy. Using (31)P NMR, it was found that melittin-lipid bilayers form
magnetically oriented elongated vesicles with the long axis parallel to the
magnetic field above the liquid crystalline-gel phase transition temperature
(T(m) = 24 degrees C). The conformation, orientation, and dynamics of melittin
bound to the membrane were further determined by using this magnetically oriented
lipid bilayer system. For this purpose, the (13)C NMR spectra of site
specifically (13)C-labeled melittin bound to the membrane in the static, fast
magic angle spinning (MAS) and slow MAS conditions were measured. Subsequently,
we analyzed the (13)C chemical shift tensors of carbonyl carbons in the peptide
backbone under the conditions where they form an alpha-helix and reorient rapidly
about the average helical axis. Finally, it was found that melittin adopts a
transmembrane alpha-helix whose average axis is parallel to the bilayer normal.
The kink angle between the N- and C-terminal helical rods of melittin in the
lipid bilayer is approximately 140 degrees or approximately 160 degrees, which is
larger than the value of 120 degrees determined by x-ray diffraction studies.
Pore formation was clearly observed below the T(m) in the initial stage of lysis
by microscope. This is considered to be caused by the association of melittin
molecules in the lipid bilayer.
PMID- 10777737
TI - 15N NMR study of the ionization properties of the influenza virus fusion peptide
in zwitterionic phospholipid dispersions.
AB - Influenza virus hemagglutinin (HA)-mediated membrane fusion involves insertion
into target membranes of a stretch of amino acids located at the N-terminus of
the HA(2) subunit of HA at low pH. The pK(a) of the alpha-amino group of (1)Gly
of the fusion peptide was measured using (15)N NMR. The pK(a) of this group was
found to be 8.69 in the presence of DOPC (1,2-dioleoyl-sn-glycero-3
phosphocholine). The high value of this pK(a) is indicative of stabilization of
the protonated form of the amine group through noncovalent interactions. The
shift reagent Pr(3+) had large effects on the (15)N resonance from the alpha
amino group of Gly(1) of the fusion peptide in DOPC vesicles, indicating that the
terminal amino group was exposed to the bulk solvent, even at low pH.
Furthermore, electron paramagnetic resonance studies on the fusion peptide region
of spin-labeled derivatives of a larger HA construct are consistent with the N
terminus of this peptide being at the depth of the phosphate headgroups. We
conclude that at both neutral and acidic pH, the N-terminal of the fusion peptide
is close to the aqueous phase and is protonated. Thus neither a change in the
state of ionization nor a significant increase in membrane insertion of this
group is associated with increased fusogenicity at low pH.
PMID- 10777738
TI - Solvent drag across gramicidin channels demonstrated by microelectrodes.
AB - The competition of ion and water fluxes across gramicidin channels was assessed
from the concentration distributions of both pore-impermeable and -permeable
cations that were simultaneously measured by double-barreled microelectrodes in
the immediate vicinity of a planar bilayer. Because water movement across the
membrane led to accumulation of solutes on one side of the membrane and depletion
on the other, the permeable cation was not only pushed by water across the
channel (true solvent drag); it also flowed along its concentration gradient
(pseudo-solvent drag). For the demonstration of true solvent drag, a difference
between the bulk concentrations on the hypertonic and the hypotonic sides of the
membrane was established. It was adjusted to get equal cation concentrations at
both membrane/water interfaces. From the sodium and potassium fluxes measured
along with membrane conductivity under these conditions, approximately five water
molecules were found to be transported simultaneously with one ion through the
channel. In diphytanoyl phosphatidylcholine membranes, a single-channel hydraulic
permeability coefficient of 1.6 x 10(-14) cm(3) s(-1) was obtained.
PMID- 10777739
TI - Correlation of membrane/water partition coefficients of detergents with the
critical micelle concentration.
AB - The membrane/water partition coefficients, K, of 15 electrically neutral (non
charged or zwitterionic) detergents were measured with phospholipid vesicles by
using isothermal titration calorimetry, and were compared to the corresponding
critical micellar concentrations, cmc. The detergents measured were
oligo(ethylene oxide) alkyl ethers (C(m)EO(n) with m = 10/n = 3, 7 and m = 12/n =
3.8); alkylglucosides (octyl, decyl); alkylmaltosides (octyl, decyl, dodecyl);
diheptanoylphosphatidylcholine; Tritons (X-100, X-114) and CHAPS. A linear
relation between the free energies of partitioning into the membrane and micelle
formation was found such that K. CMC approximately 1. The identity K. CMC = 1 was
used to classify detergents with respect to their membrane disruption potency.
"Strong" detergents are characterized by K. CMC < 1 and solubilize lipid
membranes at detergent-to-lipid ratios X(b) < 1 (alkylmaltosides, tritons,
heptaethylene glycol alkyl ethers). "Weak" detergents are characterized by K. CMC
> 1 and accumulate in the membrane- to detergent-to-lipid ratios X(b) > 1 before
the bilayer disintegrates (alkylglucosides, pentaethylene glycol dodecyl ether).
PMID- 10777740
TI - A (2)H NMR study of macroscopically aligned bilayer membranes containing
interfacial hydroxyl residues.
AB - The polar interface of membranes containing phosphatidylglycerol or cholesterol
was studied by (2)H nuclear magnetic resonance (NMR) as a function of membrane
hydration. The membranes were macroscopically aligned and hydrated with deuterium
oxide. Water uptake and membrane annealing was achieved under NMR control, using
a novel hydration technique. Well-resolved (2)H quadrupolar doublets were
obtained from individual hydroxyl residues and from the interlamellar water. The
response of the phosphatidylglycerol headgroup and of the cholesterol molecule to
the spontaneous evaporation of interlamellar water could be thus monitored
continuously. It is shown that the phosphatidylglycerol headgroup undergoes
changes of conformation and average orientation with respect to the membrane
surface and that the off-axis motion of the cholesterol molecule decreases. The
deuteron exchange between hydroxyl residues and surface-associated D(2)O was
determined by an inversion transfer technique. The exchange rates of the hydroxyl
residues in the phosphatidylglycerol headgroup were different and depended
strongly on the total hydration of the membrane. Significantly lower and almost
hydration-independent rates were obtained for cholesterol. These results will be
discussed with reference to earlier reports on the headgroup dynamics of
phosphatidylglycerol and on the interaction of cholesterol with the membrane
water interface.
PMID- 10777741
TI - Effect of trehalose and sucrose on the hydration and dipole potential of lipid
bilayers.
AB - The water activity in dimyristoylphosphatidylcholine (DMPC) decreases by 60% when
the lipid is dehydrated in the presence of trehalose concentrations higher than
0.02 M. In contrast, sucrose in concentrations 10 times higher produced only a
20% decrease in the water activity in the sample. Titrations of a DMPC solution
in chloroform yielded 14 water molecules per lipid when pure water was added and
seven water molecules per lipid when the titration was done with 0.025 M
trehalose. The same concentrations of sucrose produced a turbid solution, which
made it impossible to quantify the number of water molecules per lipid. Lipid
monolayers spread on an air/water interface showed a decrease from 480 mV in pure
water to 425 mV in 0.1 M trehalose. However, the same concentrations of sucrose
produced an increase of less than 100 mV. Results obtained with Fourier transform
infrared spectroscopy (FTIR) under the same conditions denoted that trehalose
binds to the carbonyl groups, while sucrose showed no specific binding. It is
concluded that per lipid molecule, 11 of 14 water molecules can be replaced by
three trehalose molecules. About four are displaced by changes in the water
activity of the bulk solution, and seven by specific interactions with the
phospholipids. In this last case, at least two of them are linked to the
carbonyls, and this appears to be the cause of the decrease in the dipole
potential of the membrane. In contrast, four sucrose molecules displace only
three water molecules per lipid, with no effect on the dipole potential or the
carbonyl groups.
PMID- 10777743
TI - Kinetics of linear rouleaux formation studied by visual monitoring of red cell
dynamic organization.
AB - Red blood cells (RBCs) in the presence of plasma proteins or other macromolecules
may form aggregates, normally in rouleaux formations, which are dispersed with
increasing blood flow. Experimental observations have suggested that the
spontaneous aggregation process involves the formation of linear rouleaux (FLR)
followed by formation of branched rouleaux networks. Theoretical models for the
spontaneous rouleaux formation were formulated, taking into consideration that
FLR may involve both "polymerization," i.e., interaction between two single RBCs
(e + e) and the addition of a single RBC to the end of an existing rouleau (e +
r), as well as "condensation" between two rouleaux by end-to-end addition (r +
r). The present study was undertaken to experimentally examine the theoretical
models and their assumptions, by visual monitoring of the spontaneous FLR (from
singly dispersed RBC) in plasma, in a narrow gap flow chamber. The results
validate the theoretical model, showing that FLR involves both polymerization and
condensation, and that the kinetic constants for the above three types of
intercellular interactions are the same, i.e., k(ee) = k(er) = k(rr) = k, and for
all tested hematocrits (0.625-6%) k < 0.13 +/- 0.03 s(-1).
PMID- 10777742
TI - Dimyristoylphosphatidylcholine/C16:0-ceramide binary liposomes studied by
differential scanning calorimetry and wide- and small-angle x-ray scattering.
AB - Ceramide has recently been established as a central messenger in the signaling
cascades controlling cell behavior. Physicochemical studies have revealed a
strong tendency of this lipid toward phase separation in mixtures with
phosphatidylcholines. The thermal phase behavior and structure of fully hydrated
binary membranes composed of dimyristoylphosphatidylcholine (DMPC) and N
palmitoyl-ceramide (C16:0-ceramide, up to a mole fraction X(cer) = 0.35) were
resolved in further detail by high-sensitivity differential scanning calorimetry
(DSC) and x-ray diffraction. Both methods reveal very strong hysteresis in the
thermal phase behavior of ceramide-containing membranes. A partial phase diagram
was constructed based on results from a combination of these two methods. DSC
heating scans show that with increased X(cer) the pretransition temperature T(p)
first increases, whereafter at X(cer) > 0.06 it can no longer be resolved. The
main transition enthalpy DeltaH remains practically unaltered while its width
increases significantly, and the upper phase boundary temperature of the mixture
shifts to approximately 63 degrees C at X(cer) = 0.30. Upon cooling, profound
phase separation is evident, and for all of the studied compositions there is an
endotherm in the region close to the T(m) for DMPC. At X(cer) >/= 0.03 a second
endotherm is evident at higher temperatures, starting at 32.1 degrees C and
reaching 54.6 degrees C at X(cer) = 0.30. X-ray small-angle reflection heating
scans reveal a lamellar phase within the temperature range of 15-60 degrees C,
regardless of composition. The pretransition is observed up to X(cer) < 0.18,
together with an increase in T(p). In the gel phase the lamellar repeat distance
d increases from approximately 61 A at X(cer) = 0. 03, to 67 A at X(cer) = 0.35.
In the fluid phase increasing X(cer) from 0.06 to 0.35 augments d from 61 A to 64
A. An L(beta')/L(alpha) (ripple/fluid) phase coexistence region is observed at
high temperatures (from 31 to 56.5 degrees C) when X(cer) > 0.03. With cooling
from temperatures above 50 degrees C we observe a slow increase in d as the
coexistence region is entered. A sudden solidification into a metastable,
modulated gel phase with high d values is observed for all compositions at
approximately 24 degrees C. The anomalous swelling for up to X(cer) = 0.30 in the
transition region is interpreted as an indication of bilayer softening and
thermally reduced bending rigidity.
PMID- 10777744
TI - The effect of peptide/lipid hydrophobic mismatch on the phase behavior of model
membranes mimicking the lipid composition in Escherichia coli membranes.
AB - The effect of hydrophobic peptides on the lipid phase behavior of an aqueous
dispersion of dioleoylphosphatidylethanolamine and dioleoylphosphatidylglycerol
(7:3 molar ratio) was studied by (31)P NMR spectroscopy. The peptides (WALPn
peptides, where n is the total number of amino acid residues) are designed as
models for transmembrane parts of integral membrane proteins and consist of a
hydrophobic sequence of alternating leucines and alanines, of variable length,
that is flanked on both ends by tryptophans. The pure lipid dispersion was shown
to undergo a lamellar-to-isotropic phase transition at approximately 60 degrees
C. Small-angle x-ray scattering showed that at a lower water content a cubic
phase belonging to the space group Pn3m is formed, suggesting also that the
isotropic phase in the lipid dispersion represents a cubic liquid crystalline
phase. It was found that the WALP peptides very efficiently promote formation of
nonlamellar phases in this lipid system. At a peptide-to-lipid (P/L) molar ratio
of 1:1000, the shortest peptide used, WALP16, lowered the lamellar-to-isotropic
phase transition by approximately 15 degrees C. This effect was less for longer
peptides. For all of the WALP peptides used, an increase in peptide concentration
led to a further lowering of the phase transition temperature. At the highest P/L
ratio (1:25) studied, WALP16 induced a reversed hexagonal liquid crystalline
(H(II)) phase, while the longer peptides still promoted the formation of an
isotropic phase. Peptides with a hydrophobic length larger than the bilayer
thickness were found to be unable to inhibit formation of the isotropic phase.
The results are discussed in terms of mismatch between the hydrophobic length of
the peptide and the hydrophobic thickness of the lipid bilayer and its
consequences for lipid-protein interactions in membranes.
PMID- 10777745
TI - A thermodynamic study of the effects of cholesterol on the interaction between
liposomes and ethanol.
AB - The association of ethanol with unilamellar dimyristoyl phosphatidylcholine
(DMPC) liposomes of varying cholesterol content has been investigated by
isothermal titration calorimetry over a wide temperature range (8-45 degrees C).
The calorimetric data show that the interaction of ethanol with the lipid
membranes is endothermic and strongly dependent on the phase behavior of the
mixed lipid bilayer, specifically whether the lipid bilayer is in the solid
ordered (so), liquid disordered (ld), or liquid ordered (lo) phase. In the low
concentration regime (<10 mol%), cholesterol enhances the affinity of ethanol for
the lipid bilayer compared to pure DMPC bilayers, whereas higher levels of
cholesterol (>10 mol%) reduce affinity of ethanol for the lipid bilayer.
Moreover, the experimental data reveal that the affinity of ethanol for the DMPC
bilayers containing small amounts of cholesterol is enhanced in the region around
the main phase transition. The results suggest the existence of a close
relationship between the physical structure of the lipid bilayer and the
association of ethanol with the bilayer. In particular, the existence of
dynamically coexisting domains of gel and fluid lipids in the transition
temperature region may play an important role for association of ethanol with the
lipid bilayers. Finally, the relation between cholesterol content and the
affinity of ethanol for the lipid bilayer provides some support for the in vivo
observation that cholesterol acts as a natural antagonist against alcohol
intoxication.
PMID- 10777746
TI - A chloride-activated Na(+)/HCO(3)(-)-coupled transport activity in corneal
endothelial membranes.
AB - Investigations of corneal endothelium were made to resolve the apparent
contradiction of the presence of sodium/bicarbonate cotransporter (NBC) in fresh
and cultured cells and NBC's reported absence in isolated plasma membrane
vesicles. Gradient-driven ion fluxes into the vesicles were measured. Short-term
incubations (0-30 s) showed the presence of a bicarbonate-dependent inward sodium
flux (BDSF), which was active when the insides of the vesicles were preloaded
with chloride ions. The BDSF was absent if chloride was present only externally
to the vesicles. Chloride at concentrations between 30 and 40 mM inside the
vesicle had its maximum effect on BDSF. Other anions (acetate, thiocyanate, or
gluconate) inside the vesicles did not mimic the chloride effect. Associated with
the net inward sodium flux was a net inward bicarbonate flux. Hill plots of
sodium influx with respect to external bicarbonate concentrations indicated that
the stoichiometry of the net transfer was 1.7 +/- 0.2 (mean +/- standard error, n
= 5) bicarbonate ions for each sodium ion transported. There was no net chloride
flux found across the membrane vesicles. The finding of a novel chloride
activated NBC activity fully resolves the apparent contradiction between whole
cell and membrane vesicle preparations.
PMID- 10777747
TI - Orientation of the infrared transition moments for an alpha-helix.
AB - Appropriate values for the orientation of the amide transition dipoles are
essential to the growing use of isotopically edited vibrational spectroscopy
generally in structural biology and to infrared dichroism measurements on
membrane-associated alpha-helices, in particular. The orientations of the
transition moments for the amide vibrations of an alpha-helix have been
determined from the ratio of intensities of the A- and E(1)-symmetry modes in the
infrared spectra of poly(gamma-methyl-L-glutamate)(x)-co-(gamma-n-octadecyl-L
glutamate)( y) oriented on silicon substrates. Samples possessing a high degree
of alignment were used to facilitate band fitting. Consistent results were
obtained from both attenuated total reflection and transmission experiments with
polarized radiation, yielding values of Theta(I) = 38 degrees, Theta(II) = 73
degrees, and Theta(A) = 29 degrees, relative to the helix axis, for the amide I,
amide II, and amide A bands, respectively. The measurements are discussed both in
the context of the somewhat divergent older determinations, and in relation to
the helix geometry and results on model amide compounds, to resolve current
uncertainties in the literature.
PMID- 10777748
TI - In vivo x-ray diffraction of indirect flight muscle from Drosophila melanogaster.
AB - Small-angle x-ray diffraction from isolated muscle preparations is commonly used
to obtain time-resolved structural information during contraction. We extended
this technique to the thoracic flight muscles of living fruit flies, at rest and
during tethered flight. Precise measurements at 1-ms time resolution indicate
that the myofilament lattice spacing does not change significantly during
oscillatory contraction. This result is consistent with the notion that a net
radial force maintains the thick filaments at an equilibrium interfilament
spacing of approximately 56 nm throughout the contractile cycle. Transgenic flies
with amino-acid substitutions in the conserved phosphorylation site of the myosin
regulatory light chain (RLC) exhibit structural abnormalities that can explain
their flight impairment. The I(20)/I(10) equatorial intensity ratio of the mutant
fly is 35% less than that of wild type, supporting the hypothesis that myosin
heads that lack phosphorylated RLC remain close to the thick filament backbone.
This new experimental system facilitates investigation of the relation between
molecular structure and muscle function in living organisms.
PMID- 10777749
TI - Thymosin-beta(4) changes the conformation and dynamics of actin monomers.
AB - Thymosin-beta(4) (Tbeta(4)) binds actin monomers stoichiometrically and maintains
the bulk of the actin monomer pool in metazoan cells. Tbeta(4) binding quenches
the fluorescence of N-iodoacetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine (AEDANS)
conjugated to Cys(374) of actin monomers. The K(d) of the actin-Tbeta(4) complex
depends on the cation and nucleotide bound to actin but is not affected by the
AEDANS probe. The different stabilities are determined primarily by the rates of
dissociation. At 25 degrees C, the free energy of Tbeta(4) binding MgATP-actin is
primarily enthalpic in origin but entropic for CaATP-actin. Binding is coupled to
the dissociation of bound water molecules, which is greater for CaATP-actin than
MgATP-actin monomers. Proteolysis of MgATP-actin, but not CaATP-actin, at Gly(46)
on subdomain 2 is >12 times faster when Tbeta(4) is bound. The C terminus of
Tbeta(4) contacts actin near this cleavage site, at His(40). By tritium exchange,
Tbeta(4) slows the exchange rate of approximately eight rapidly exchanging amide
protons on actin. We conclude that Tbeta(4) changes the conformation and
structural dynamics ("breathing") of actin monomers. The conformational change
may reflect the unique ability of Tbeta(4) to sequester actin monomers and
inhibit nucleotide exchange.
PMID- 10777750
TI - Conformational deformability of RNA: a harmonic mode analysis.
AB - The harmonic mode analysis method was used to characterize the conformational
deformability of regular Watson-Crick paired, mismatch- and bulge-containing RNA.
Good agreement between atomic Debye-Waller factors derived from x-ray
crystallography of a regular RNA oligonucleotide and calculated atomic
fluctuations was obtained. Calculated helical coordinate fluctuations showed a
small sequence dependence of up to approximately 30-50%. A negative correlation
between motions at a given base pair step and neighboring steps was found for
most helical coordinates. Only very few calculated modes contribute significantly
to global motions such as bending, twisting, and stretching of the RNA molecules.
With respect to a local helical description of the RNA helix our calculations
suggest that RNA bending is mostly due to a periodic change in the base pair step
descriptors slide and roll. The presence of single guanine:uridine or
guanine:adenine mismatches had little influence on the calculated RNA
flexibility. In contrast, for tandem guanine:adenine base pairs the harmonic mode
approach predicts a significantly reduced conformational flexibility in the case
of a sheared arrangement and slightly enhanced flexibility for a face-to-face
(imino proton) pairing relative to regular RNA. The presence of a single extra
adenine bulge nucleotide stacked between flanking sequences resulted in an
increased local atomic mobility around the bulge site (approximately 40%) and a
slightly enhanced global bending flexibility. For an adenine bulge nucleotide in
a looped-out conformation a strongly enhanced bulge nucleotide mobility but no
increased bending flexibility compared to regular RNA was found.
PMID- 10777752
TI - Sequence-dependent dynamics in duplex DNA.
AB - The submicrosecond bending dynamics of duplex DNA were measured at a single site,
using a site-specific electron paramagnetic resonance active spin probe. The
observed dynamics are interpreted in terms of the mean squared amplitude of
bending relative to the end-to-end vector defined by the weakly bending rod
model. The bending dynamics monitored at the single site varied when the length
and position of a repeated AT sequence, distant from the spin probe, were
changed. As the distance between the probe and the AT sequence was increased, the
mean squared amplitude of bending seen by the probe due to that sequence
decreased. A model for the sequence-dependent internal flexural motion of duplex
DNA, which casts the mean squared bending amplitudes in terms of sequence
dependent bending parameters, has been developed. The best fit of the data to the
model occurs when the (AT)(n) basepairs are assumed to be 20% more flexible than
the average of the basepairs within the control sequence. These findings provide
a quantitative basis for interpreting the kinetics of biological processes that
depend on duplex DNA flexibility, such as protein recognition and chromatin
packaging.
PMID- 10777751
TI - Structural changes induced by binding of the high-mobility group I protein to a
mouse satellite DNA sequence.
AB - Using spectroscopic methods, we have studied the structural changes induced in
both protein and DNA upon binding of the High-Mobility Group I (HMG-I) protein to
a 21-bp sequence derived from mouse satellite DNA. We show that these structural
changes depend on the stoichiometry of the protein/DNA complexes formed, as
determined by Job plots derived from experiments using pyrene-labeled duplexes.
Circular dichroism and melting temperature experiments extended in the far
ultraviolet range show that while native HMG-I is mainly random coiled in
solution, it adopts a beta-turn conformation upon forming a 1:1 complex in which
the protein first binds to one of two dA.dT stretches present in the duplex. HMG
I structure in the 1:1 complex is dependent on the sequence of its DNA target. A
3:1 HMG-I/DNA complex can also form and is characterized by a small increase in
the DNA natural bend and/or compaction coupled to a change in the protein
conformation, as determined from fluorescence resonance energy transfer (FRET)
experiments. In addition, a peptide corresponding to an extended DNA-binding
domain of HMG-I induces an ordered condensation of DNA duplexes. Based on the
constraints derived from pyrene excimer measurements, we present a model of these
nucleated structures. Our results illustrate an extreme case of protein structure
induced by DNA conformation that may bear on the evolutionary conservation of the
DNA-binding motifs of HMG-I. We discuss the functional relevance of the
structural flexibility of HMG-I associated with the nature of its DNA targets and
the implications of the binding stoichiometry for several aspects of chromatin
structure and gene regulation.
PMID- 10777754
TI - Aspartate 75 mutation in sensory rhodopsin II from Natronobacterium pharaonis
does not influence the production of the K-like intermediate, but strongly
affects its relaxation pathway.
AB - The early steps in the photocycle of the aspartate 75-mutated sensory rhodopsin
II from Natrobacterium pharaonis (pSRII-D75N) were studied by time-resolved laser
induced optoacoustic spectroscopy combined with quantum yield determinations by
flash photolysis with optical detection. Similar to the case of pSRII-WT,
excitation of pSRII-D75N produces in subnanosecond time a K-like intermediate.
Different to the case of K in pSRII-WT, in pSRII-D75N there are two K states.
K(E) decays into K(L) with a lifetime of 400 ns (independent of temperature in
the range 6.5-52 degrees C) which is optically silent under the experimental
conditions of our transient absorption experiments. This decay is concomitant
with an expansion of 6.5 ml/mol of produced intermediate. This indicates a
protein relaxation not affecting the chromophore absorption. For pSRII-D75N
reconstituted into polar lipids from purple membrane, the mutation of Asp-75 by
the neutral residue Asn affects neither the K(E) production yield (PhiK(e) 0.51
+/- 0.05) nor the energy stored by this intermediate (E(E)K(E) = 91 +/- 11
kJ/mol), nor the expansion upon its production (DeltaV(R,1) = 10 +/- 0.3 ml/mol).
All these values are very similar to those previously determined for K with pSRII
WT in the same medium. The millisecond transient species is attributed to K(L)
with a lifetime corresponding to that determined by electronic absorption
spectroscopy for K(565). The determined energy content of the intermediates as
well as the structural volume changes for the various steps afford the
calculation of the free energy profile of the phototransformation during the
pSRII-D75N photocycle. These data offer insights regarding the photocycle in
pSRII-WT. Detergent solubilization of pSRII-D75N affects the sample properties to
a larger extent than in the case of pSRII-WT.
PMID- 10777753
TI - Photosensitizer binding to lipid bilayers as a precondition for the
photoinactivation of membrane channels.
AB - The photodynamic activity of sulfonated aluminum phthalocyanines (AlPcS(n), 1 =
n = 4) was found to correlate with their affinity for membrane lipids.
Adsorbing to the surface of large unilamellar vesicles (LUVs), aluminum
phthalocyanine disulfonate induced the highest changes in their electrophoretic
mobility. AlPcS(2) was also most efficient in mediating photoinactivation of
gramicidin channels, as revealed by measurements of the electric current across
planar lipid bilayers. The increase in the degree of sulfonation of
phthalocyanine progressively reduced its affinity for the lipid bilayer as well
as its potency of sensitizing gramicidin channel photoinactivation. The portion
of photoinactivated gramicidin channels, alpha, increased with rising
photosensitizer concentration up to some optimum. The concentration at which
alpha was at half-maximum amounted to 80 nM, 30 nM, 200 nM, and 2 microM for
AlPcS(1), AlPcS(2), AlPcS(3), and AlPcS(4), respectively. At high concentrations
alpha was found to decrease, which was attributed to quenching of reactive oxygen
species and self-quenching of the photosensitizer triplet state by its ground
state. Fluoride anions were observed to inhibit both AlPcS(n) (2 = n = 4)
binding to LUVs and sensitized photoinactivation of gramicidin channels. It is
concluded that photosensitizer binding to membrane lipids is a prerequisite for
the photodynamic inactivation of gramicidin channels.
PMID- 10777755
TI - B800-->B850 energy transfer mechanism in bacterial LH2 complexes investigated by
B800 pigment exchange.
AB - Femtosecond transient absorption measurements were performed on native and a
series of reconstituted LH2 complexes from Rhodopseudomonas acidophila 10050 at
room temperature. The reconstituted complexes contain chemically modified
tetrapyrrole pigments in place of the native bacteriochlorophyll a-B800
molecules. The spectral characteristics of the modified pigments vary
significantly, such that within the B800 binding sites the B800 Q(y) absorption
maximum can be shifted incrementally from 800 to 670 nm. As the spectral overlap
between the B800 and B850 Q(y) bands decreases, the rate of energy transfer (as
determined by the time-dependent bleaching of the B850 absorption band) also
decreases; the measured time constants range from 0.9 ps (bacteriochlorophyll a
in the B800 sites, Q(y) absorption maximum at 800 nm) to 8.3 ps (chlorophyll a in
the B800 sites, Q(y) absorption maximum at 670 nm). This correlation between
energy transfer rate and spectral blue-shift of the B800 absorption band is in
qualitative agreement with the trend predicted from Forster spectral overlap
calculations, although the experimentally determined rates are approximately 5
times faster than those predicted by simulations. This discrepancy is attributed
to an underestimation of the electronic coupling between the B800 and B850
molecules.
PMID- 10777756
TI - Photochemical oxygen consumption sensitized by a porphyrin phosphorescent probe
in two model systems.
AB - Phosphorescence quenching of certain metalloporphyrins is used to measure tissue
and microvascular pO(2). Oxygen quenching of metalloporphyrin triplet states
creates singlet oxygen, which is highly reactive in biological systems, and these
oxygen-consuming reactions are capable of perturbing tissue oxygenation. Kinetics
of photochemical oxygen consumption were measured for a Pd-porphyrin in two model
systems in vitro over a range of irradiances (1.34-134 mW cm(-2)). For a given
irradiance, and, after correction for differing porphyrin concentrations, rates
of oxygen consumption were similar when the Pd-porphyrin was bound to bovine
serum albumin and when it was taken up by tumor cells in spheroids. At
irradiances comparable to those used in imaging superficial anatomy, rates of
oxygen consumption were sufficiently low (2.5 microM s(-1)) that tissue
oxygenation would be reduced by a maximum of 6%. An irradiance of 20 mW cm(-2),
however, initiated a rate of oxygen consumption capable of reducing tissue pO(2)
by at least 20-40%. These measured rates of consumption impose limitations on the
use of phosphorescence quenching in thick tissues. The irreversible
photobleaching of the Pd-porphyrin was also measured indirectly. The bleaching
branching ratio, 23 M(-1), is significantly lower than that of porphyrin
photodynamic agents.
PMID- 10777757
TI - Intracellular reactions in single human granulocytes upon phorbol myristate
acetate activation using confocal Raman microspectroscopy.
AB - We have obtained new evidence for the occurrence of intracellular NADPH-oxidase
activity in neutrophilic and eosinophilic granulocytes upon stimulation with
phorbol myristate acetate (PMA). PMA activation leads to a partial translocation
of cytochrome b(558) from the membranes of the specific granules to the plasma
membrane. It was suggested that NADPH-oxidase activity only takes place in the
plasma membrane, leading to an extracellular release of oxygen metabolites
because cellular self-destruction can be avoided in this way. The effects of PMA
activation were indirectly studied in recent experiments employing scavengers of
extracellular superoxide anion and hydrogen peroxide, and support for
intracellular NADPH-oxidase activity was obtained. In this paper we use Raman
microspectroscopy as a direct method to study intracellular molecular reactions
that result from cellular triggering by PMA. The molecular specificity of this
microscopic method enables us to show that intracellular reduction of both
myeloperoxidase (MPO) and cytochrome b(558) occurs in neutrophilic granulocytes.
Control measurements with cytochrome b(558)-deficient neutrophilic granulocytes
did not show a reduction of intracellular MPO. This is direct support for the
occurrence of intracellular NADPH-oxidase activity in organelles that must be in
close contact with the azurophilic granules that contain MPO. Furthermore, a
comparison was made with chemical reactions occurring in eosinophilic
granulocytes after activation with PMA. Moreover, in these cells an intracellular
reduction of eosinophil peroxidase was observed.
PMID- 10777758
TI - Restrained torsional dynamics of nuclear DNA in living proliferative mammalian
cells.
AB - Physical parameters, describing the state of chromatinized DNA in living
mammalian cells, were revealed by in situ fluorescence dynamic properties of
ethidium in its free and intercalated states. The lifetimes and anisotropy decays
of this cationic chromophore were measured within the nuclear domain, by using
the ultra-sensitive time-correlated single-photon counting technique, confocal
microscopy, and ultra-low probe concentrations. We found that, in living cells:
1) free ethidium molecules equilibrate between extracellular milieu and nucleus,
demonstrating that the cation is naturally transported into the nucleus; 2) the
intercalation of ethidium into chromatinized DNA is strongly inhibited, with
relaxation of the inhibition after mild (digitonin) cell treatment; 3)
intercalation sites are likely to be located in chromatin DNA; and 4) the
fluorescence anisotropy relaxation of intercalated molecules is very slow. The
combination of fluorescence kinetic and fluorescence anisotropy dynamics
indicates that the torsional dynamics of nuclear DNA is highly restrained in
living cells.
PMID- 10777760
TI - Observing secretory granules with a multiangle evanescent wave microscope.
AB - In total internal reflection fluorescence microscopy (TIRFM), fluorophores near a
surface can be excited with evanescent waves, which decay exponentially with
distance from the interface. Penetration depths of evanescent waves from 60 nm to
300 nm were generated by varying the angle of incidence of a laser beam. With a
novel telecentric multiangle evanescent wave microscope, we monitored and
investigated both single secretory granules and pools of granules in bovine
chromaffin cells. By measuring the fluorescence intensity as a function of
penetration depth, it is possible through a Laplace transform to obtain the
fluorophore distribution as a function of axial position. We discuss the extent
to which it is possible to determine distances and diameters of granules with
this microscopy technique by modeling the fluorescent volumes of spheres in
evanescent fields. The anisotropic near-field detection of fluorophores and the
influence of the detection point-spread function are considered. The diameters of
isolated granules between 70 nm and 300 nm have been reconstructed, which is
clearly beyond the resolution limit of a confocal microscope. Furthermore, the
paper demonstrates how evanescent waves propagate along surfaces and scatter at
objects with a higher refractive index. TIRFM will have a limited applicability
for quantitative measurements when the parameters used to define evanescent waves
are not optimally selected.
PMID- 10777759
TI - Rapid flip-flop of phospholipids in endoplasmic reticulum membranes studied by a
stopped-flow approach.
AB - The transbilayer movement of short-chain spin-labeled and fluorescent 7-nitrobenz
2-oxa-1,3-diazol-4-yl (NBD) phospholipid analogs in rat liver microsomes is
measured by stopped-flow mixing of labeled microsomes with bovine serum albumin
(BSA) solution. Extraction of analogs from the outer leaflet of microsomes to BSA
can be directly monitored in conjunction with electron paramagnetic resonance or
fluorescence spectroscopy by taking advantage of the fact that the signal of spin
labeled or fluorescent analogs bound to BSA is different from that of the analogs
inserted into membranes. From the signal kinetics, the transbilayer movement and
the distribution of analogs in microsomal membranes can be derived provided the
extraction of analogs by BSA is much faster in comparison to the transbilayer
movement of analogs. Half-times of the back-exchange for spin-labeled and
fluorescent analogs were <3.5 and <9.5 s, respectively. The unprecedented time
resolution of the assay revealed that the transbilayer movement of spin-labeled
analogs is much faster than previously reported. The half-time of the movement
was about 16 s or even less at room temperature. Transmembrane movement of NBD
labeled analogs was six- to eightfold slower than that of spin-labeled analogs.
PMID- 10777761
TI - Estimating intracellular calcium concentrations and buffering without wavelength
ratioing.
AB - We describe a method for determining intracellular free calcium concentration
([Ca(2+)]) from single-wavelength fluorescence signals. In contrast to previous
single-wavelength calibration methods, the proposed method does not require
independent estimates of resting [Ca(2+)] but relies on the measurement of
fluorescence close to indicator saturation during an experiment. Consequently, it
is well suited to [Ca(2+)] indicators for which saturation can be achieved under
physiological conditions. In addition, the method requires that the indicators
have large dynamic ranges. Popular indicators such as Calcium Green-1 or Fluo-3
fulfill these conditions. As a test of the method, we measured [Ca(2+)] in CA1
pyramidal neurons in rat hippocampal slices using Oregon Green BAPTA-1 and 2
photon laser scanning microscopy (BAPTA: 1,2-bis(2-aminophenoxy)ethane-N,N,N', N'
tetraacetic acid). Resting [Ca(2+)] was 32-59 nM in the proximal apical dendrite.
Monitoring action potential-evoked [Ca(2+)] transients as a function of indicator
loading yielded estimates of endogenous buffering capacity (44-80) and peak
[Ca(2+)] changes at zero added buffer (178-312 nM). In young animals (postnatal
days 14-17) our results were comparable to previous estimates obtained by
ratiometric methods (, Biophys. J. 70:1069-1081), and no significant differences
were seen in older animals (P24-28). We expect our method to be widely applicable
to measurements of [Ca(2+)] and [Ca(2+)]-dependent processes in small neuronal
compartments, particularly in the many situations that do not permit wavelength
ratio imaging.
PMID- 10777762
TI - Direct probing by atomic force microscopy of the cell surface softness of a
fibrillated and nonfibrillated oral streptococcal strain.
AB - In this paper, direct measurement by atomic force microscopy (AFM) of the cell
surface softness of a fibrillated oral streptococcal strain Streptococcus
salivarius HB and of a nonfibrillated strain S. salivarius HBC12 is presented,
and the data interpretation is validated by comparison with results from
independent techniques. Upon approach of the fibrillated strain in water, the AFM
tip experienced a long-range repulsion force, starting at approximately 100 nm,
attributed to the compression of the soft layer of fibrils present at the cell
surface. In 0.1 M KCl, repulsion was only experienced when the tip was closer
than approximately 10 nm, reflecting a stiffer cell surface due to collapse of
the fibrillar mass. Force-distance curves indicated that the nonfibrillated
strain, probed both in water and in 0.1 M KCl, was much stiffer than the
fibrillated strain in water, and a repulsion force was experienced by the tip at
close approach only (20 nm in water and 10 nm in 0.1 M KCl). Differences in cell
surface softness were further supported by differences in cell surface
morphology, the fibrillated strain imaged in water being the only specimen that
showed characteristic topographical features attributable to fibrils. These
results are in excellent agreement with previous indirect measurements of cell
surface softness by dynamic light scattering and particulate microelectrophoresis
and demonstrate the potential of AFM to directly probe the softness of microbial
cell surfaces.
PMID- 10777763
TI - Hybrid scanning ion conductance and scanning near-field optical microscopy for
the study of living cells.
AB - We have developed a hybrid scanning ion conductance and scanning near-field
optical microscope for the study of living cells. The technique allows
quantitative, high-resolution characterization of the cell surface and the
simultaneous recording of topographic and optical images. A particular feature of
the method is a reliable mechanism to control the distance between the probe and
the sample in physiological buffer. We demonstrate this new method by recording
near-field images of living cells (cardiac myocytes).
PMID- 10777764
TI - Differential analysis of human leukocytes by dielectrophoretic field-flow
fractionation.
AB - The differential analysis of human leukocytes has many important biological and
medical applications. In this work, dielectrophoretic field-flow-fractionation
(DEP-FFF), a cell-separation technique that exploits the differences in the
density and dielectric properties of cells, was used to separate the mixtures of
the major human leukocyte subpopulations (T- and B-lymphocytes, monocytes, and
granulocytes). The separation was conducted in a thin chamber equipped with an
array of microfabricated interdigitated electrodes on the bottom surface, and the
separation performance was characterized by on-line flow cytometry. To
investigate optimal separation conditions for different leukocyte mixtures,
elution fractograms at various DEP field frequencies were obtained for each
leukocyte subtype. With appropriately chosen conditions, high separation
performance was achieved in separating T- (or B-) lymphocytes from monocytes, T-
(or B-) lymphocytes from granulocytes, and monocytes from granulocytes. DEP-FFF
does not involve cell-labeling or cell-modification step, and provides a new
approach to hematological analysis.
PMID- 10777765
TI - Conformational transitions in model silk peptides.
AB - Protein structural transitions and beta-sheet formation are a common problem both
in vivo and in vitro and are of critical relevance in disparate areas such as
protein processing and beta-amyloid and prion behavior. Silks provide a
"databank" of well-characterized polymorphic sequences, acting as a window onto
structural transitions. Peptides with conformationally polymorphic silk-like
sequences, expected to exhibit an intractable beta-sheet form, were characterized
using Fourier transform infrared spectroscopy, circular dichroism, and electron
diffraction. Polymorphs resembling the silk I, silk II (beta-sheet), and silk III
(threefold polyglycine II-like helix) crystal structures were identified for the
peptide fibroin C (GAGAGS repetitive sequence). Two peptides based on silk
amorphous sequences, fibroin A (GAGAGY) and fibroin V (GDVGGAGATGGS),
crystallized as silk I under most conditions. Methanol treatment of fibroin A
resulted in a gradual transition from silk I to silk II, with an intermediate
state involving a high proportion of beta-turns. Attenuated total reflectance
Fourier transform infrared spectroscopy has been used to observe conformational
changes as the peptides adsorb from solution onto a hydrophobic surface. Fibroin
C has a beta-strand structure in solution but adopts a silk I-like structure upon
adsorption, which when dried on the ZnSe crystal contains silk III crystallites.
PMID- 10777766
TI - Variable velocity liquid flow EPR applied to submillisecond protein folding.
AB - We have developed a variable velocity, rapid-mix, continuous-flow method for
observing and delineating kinetics by dielectric resonator-based electron
paramagnetic resonance (EPR). The technology opens a new facet for kinetic study
of radicals in liquid at submillisecond time resolution. The EPR system (after
Sienkiewicz, A., K. Qu, and C. P. Scholes. 1994. Rev. Sci. Instrum. 65:68-74)
accommodated a miniature quartz capillary mixer with an approximately 0.5
microliter delivery volume to the midpoint of the EPR-active zone. The flow
velocity was varied in a preprogrammed manner, giving a minimum delivery time of
approximately 150 microseconds. The mixing was efficient, and we constructed
kinetics in the 0.15-2. 1-ms time range by plotting the continuous wave EPR
signal taken during flow versus the reciprocal of flow velocity. We followed the
refolding kinetics of iso-1-cytochrome c spin-labeled at Cysteine 102. At 20
degrees C, upon dilution of guanidinium hydrochloride denaturant, a fast phase of
refolding was resolved with an exponential time constant of 0.12 ms, which was
consistent with the "burst" phase observed by optically detected flow techniques.
At 7 degrees C the kinetic refolding time of this phase increased to 0.5 ms.
PMID- 10777768
TI - Chiral discotic columnar germs of nucleosome core particles.
AB - In concentrated solution and in the presence of high concentrations of monovalent
cations, nucleosome core particles order into a discotic columnar mesophase. This
phase is limited to finite-sized hexagonal germs that further divide into six
coiled branches, following an iterative process. We show how the structure of the
germs comes from the competition between hexagonal packing and chirality with a
combination of dendritic facetting and double-twist configurations. Geometrical
considerations lead us to suspect that the chirality of the eukaryotic
chromosomes may originate from the same competition.
PMID- 10777767
TI - Motion determination in actin filament fluorescence images with a spatio-temporal
orientation analysis method.
AB - We present a novel approach of automatically measuring motion in series of
microscopic fluorescence images. As a differential method, the three-dimensional
structure tensor technique is used to calculate the displacement vector field for
every image of the sequence, from which the velocities are subsequently derived.
We have used this method for the analysis of the movement of single actin
filaments in the in vitro motility assay, where fluorescently labeled actin
filaments move over a myosin decorated surface. With its fast implementation and
subpixel accuracy, this approach is, in general, very valuable for analyzing
dynamic processes by image sequence analysis.
PMID- 10777769
TI - The extracellular signal-regulated kinase cascade is required for NMDA receptor
independent LTP in area CA1 but not area CA3 of the hippocampus.
AB - Activation of extracellular signal-regulated kinase (ERK) has been shown to be
necessary for NMDA receptor-dependent long-term potentiation (LTP). We studied
the role of ERK in three forms of NMDA receptor-independent LTP: LTP induced by
very high-frequency stimulation (200 Hz-LTP), LTP induced by the K(+) channel
blocker tetraethylammonium (TEA) (TEA-LTP), and mossy fiber (MF) LTP (MF-LTP). We
found that ERK was activated in area CA1 after the induction of both 200 Hz-LTP
and TEA-LTP and that this activation required the influx of Ca(2+) through
voltage-gated Ca(2+) channels. Inhibition of the ERK signaling cascade with
either PD 098059 or U0126 prevented the induction of both 200 Hz-LTP and TEA-LTP
in area CA1. In contrast, neither PD 098059 nor U0126 prevented MF-LTP in area
CA3 induced by either brief or long trains of high-frequency stimulation. U0126
also did not prevent forskolin-induced potentiation in area CA3. However,
incubation of slices with forskolin, an activator of the cAMP-dependent protein
kinase (PKA) cascade, did result in increases in active ERK and cAMP response
element-binding protein (CREB) phosphorylation in area CA3. The forskolin-induced
increase in active ERK was inhibited by U0126, whereas the increase in CREB
phosphorylation was not, which suggests that in area CA3 the PKA cascade is not
coupled to CREB phosphorylation via ERK. Overall, our observations indicate that
activation of the ERK signaling cascade is necessary for NMDA receptor
independent LTP in area CA1 but not in area CA3 and suggest a divergence in the
signaling cascades underlying NMDA receptor-independent LTP in these hippocampal
subregions.
PMID- 10777770
TI - Neurosteroid modulation of GABA IPSCs is phosphorylation dependent.
AB - The neurosteroid 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone)
facilitates GABA(A) receptor-mediated ionic currents via allosteric modulation of
the GABA(A) receptor. Accordingly, allopregnanolone caused an increase in the
slow decay time constant of spontaneous GABA-mediated IPSCs in magnocellular
neurons recorded in hypothalamic slices. The allopregnanolone effect on IPSCs was
inhibited by a G-protein antagonist as well as by blocking protein kinase C and,
to a lesser extent, cAMP-dependent protein kinase activities. G-protein and
protein kinase C activation in the absence of the neurosteroid had no effect on
spontaneous IPSCs but enhanced the effect of subsequent allopregnanolone
application. These findings together suggest that the neurosteroid modulation of
GABA-mediated IPSCs requires G-protein and protein kinase activation, although
not via a separate G-protein-coupled steroid receptor.
PMID- 10777771
TI - A novel particulate form of Ca(2+)/calmodulin-dependent [correction of
Ca(2+)/CaMKII-dependent] protein kinase II in neurons.
AB - Cytoskeletal and postsynaptic density (PSD) fractions from forebrain contain
discrete spherical structures that are immunopositive for Ca(2+)/calmodulin
dependent protein kinase II (CaMKII). Spherical structures viewed by rotary
shadow electron microscopy have an average diameter of approximately 100 nm and,
in distinction to postsynaptic densities, do not immunolabel for PSD-95. These
structures were purified to near homogeneity by extraction with the detergent N
lauryl sarcosinate. Biochemical analysis revealed that CaMKII accounts for
virtually all of the protein in the purified preparation, suggesting that
spherical structures are clusters of self-associated CaMKII. Exposure of cultured
hippocampal neurons to a mitochondrial uncoupler in glucose-free medium promotes
the formation of numerous CaMKII-immunopositive structures identical in size and
shape to the CaMKII clusters observed in subcellular fractions. Clustering of
CaMKII would reduce its kinase function by preventing its access to fixed
substrates. On the other hand, clustering would not affect the ability of the
large cellular pool of CaMKII to act as a calmodulin sink, as demonstrated by the
Ca(2+)-dependent binding of gold-conjugated calmodulin to CaMKII clusters. We
propose that the observed clustering of CaMKII into spherical structures is a
protective mechanism preventing excessive protein phosphorylation upon loss of
Ca(2+) homeostasis, without compromising calmodulin regulation.
PMID- 10777772
TI - Activation of group II metabotropic glutamate receptors inhibits synaptic
excitation of the substantia Nigra pars reticulata.
AB - Loss of nigrostriatal dopaminergic neurons in Parkinson's disease (PD) leads to
increased activity of glutamatergic neurons in the subthalamic nucleus (STN).
Recent studies reveal that the resultant increase in STN-induced excitation of
basal ganglia output nuclei is responsible for the disabling motor impairment
characteristic of PD. On the basis of this, it is possible that any manipulation
that reduces activity at excitatory STN synapses onto basal ganglia output nuclei
could be useful in the treatment of PD. We now report that group II metabotropic
glutamate receptors (mGluRs) are presynaptically localized on STN terminals and
that activation of these receptors inhibits excitatory transmission at STN
synapses. In agreement with the hypothesis that this could provide a therapeutic
benefit in PD, a selective agonist of group II mGluRs induces a dramatic reversal
of catalepsy in a rat model of PD. These results raise the exciting possibility
that selective agonists of group II mGluRs could provide an entirely new approach
to the treatment of PD. These novel therapeutic agents would provide a
noninvasive pharmacological treatment that does not involve the manipulation of
dopaminergic systems, thus avoiding the problems associated with current
therapies.
PMID- 10777773
TI - Evidence that G(z)-proteins couple to hypothalamic 5-HT(1A) receptors in vivo.
AB - Using in situ hybridization and immunoblot analysis, the present studies
identified G(z) mRNA and G(z)-protein in the hypothalamic paraventricular
nucleus. The role of G(z)-proteins in hypothalamic 5-HT(1A) receptor signaling
was examined in vivo. Activation of 5-HT(1A) receptors increases the secretion of
oxytocin and ACTH, but not prolactin. Intracerebroventricular infusion (3-4 d) of
G(z) antisense oligodeoxynucleotides, with different sequences and different
phosphorothioate modification patterns, reduced the levels of G(z)-protein in the
hypothalamic paraventricular nucleus, whereas missense oligodeoxynucleotides had
no effect. Neither antisense nor missense oligodeoxynucleotide treatment altered
basal plasma levels of ACTH, oxytocin, or prolactin, when compared with untreated
controls. An antisense-induced decrease in hypothalamic G(z)-protein levels was
paralleled by a significant decrease in the oxytocin and ACTH responses to the 5
HT(1A) agonist 8-hydroxy-dipropylamino-tetralin (8-OH-DPAT). In contrast, the
prolactin response to 8-OH-DPAT (which cannot be blocked by 5-HT(1A) antagonists)
was not inhibited by G(z) antisense oligodeoxynucleotides. G(z)-proteins are the
only members of the G(i)/G(o)-protein family that are not inactivated by
pertussis toxin. In a control experiment, pertussis toxin treatment (1
microgram/5 microliter, i.c.v.; 48 hr before the 8-OH-DPAT challenge) did not
inhibit the ACTH response, potentiated the oxytocin response, and eliminated the
prolactin response to 8-OH-DPAT. Thus, pertussis toxin-sensitive G(i)/G(o)
proteins do not mediate the 5-HT(1A) receptor-mediated increase in ACTH and
oxytocin secretion. Combined, these studies provide the first in vivo evidence
for a key role of G(z)-proteins in coupling hypothalamic 5-HT(1A) receptors to
effector mechanisms.
PMID- 10777774
TI - Involvement of retinoblastoma family members and E2F/DP complexes in the death of
neurons evoked by DNA damage.
AB - Neuronal death evoked by DNA damage requires cyclin-dependent kinase 4 (Cdk4) and
6 activity and is accompanied by elevation of cyclin D1-associated kinase
activity. Because Cdk4/6 phosphorylates retinoblastoma protein (pRb) family
members that then modulate the transcriptional activity of E2F/DP1 complexes, we
examined the involvement of these components in DNA damage-evoked neuronal death.
Camptothecin induced rapid pRb and p107 phosphorylation at a Cdk4/6
phosphorylation site followed by selective loss of Rb and p107. The CDK inhibitor
flavopiridol suppressed pRb and p107 phosphorylation and loss, implicating CDK
activity in these events. Moreover, the loss of pRb and p107 appeared to be
mediated by caspases because it was blocked by general caspase inhibitors. The
role of phosphorylation and pRb and p107 loss in the death pathway was indicated
by observations that virally mediated expression of pRb mutated at sites of
phosphorylation, including the Cdk4/6 site, inhibited death. Finally, expression
of dominant-negative versions of DP1, known to compromise E2F transcriptional
activity, protects cortical neurons from death induced by camptothecin and
sympathetic neurons from death evoked by UV treatment. Taken together, these
results implicate the CDK-pRb/E2F/DP pathway as a required element in the
neuronal death evoked by DNA damage.
PMID- 10777775
TI - Reluctant gating of single N-type calcium channels during neurotransmitter
induced inhibition in bullfrog sympathetic neurons.
AB - Whole-cell recordings have been used to extensively characterize the voltage
dependent inhibition of N-type calcium current induced by various
neurotransmitters. Results from these studies have yielded several predictions on
the effect of inhibition on N-channel gating, namely delayed channel opening and
inhibition-induced reluctant openings. Previous single N-channel studies observed
delayed channel opening but failed to find reluctant openings. However, strong
depolarizations may be necessary to see reluctant openings, but this was not
tested. We have examined N-channel gating at voltages depolarized to those used
previously and found a neurotransmitter-induced open state that has properties
predicted for the reluctant open state. The openings had lower open probability
(P(o)) and brief open times compared to the dominant gating state observed in
control (high P(o)). These reluctant events were reduced after strong
depolarizing pulses used to reverse inhibition. The threshold voltage for
activation of reluctant events was approximately 30 mV depolarized to that of the
normal gating state (high P(o)). However, an action potential will provide
sufficient depolarization to open reluctant N-channels.
PMID- 10777776
TI - Plasma membrane calcium pump isoform 1 gene expression is repressed by
corticosterone and stress in rat hippocampus.
AB - Glucocorticoids (GCs) are critical to learning and memory, in large part because
of their actions in the hippocampus. Chronic high levels of GCs have profound
effects on hippocampal structure and function and can even result in irreversible
neurodegeneration. Hippocampal GC actions are mediated by intracellular receptors
that modulate the transcription of specific target genes. In a screen for genes
repressed by GCs in rat hippocampus, we identified plasma membrane calcium pump
isoform 1 (PMCA1), a plasma membrane calcium ATPase. In Northern blots, PMCA1 was
repressed approximately 33% after a high, but not a low dose of the GC,
corticosterone (B), suggesting glucocorticoid (but not mineralocorticoid)
receptor-mediated repression. Furthermore, in situ hybridization demonstrated
that B significantly downregulated PMCA1 mRNA in all brain regions examined.
Repression of PMCA1 was also observed in cultured hippocampal neurons, but only
when the cells were in the differentiated state. Stress also repressed PMCA1
expression in hippocampus of adrenal-intact animals, and a clear inverse
correlation between B level and PMCA1 mRNA could be discerned. However, other non
B-dependent factors appeared to be involved in the response of PMCA1 to stress
because, unlike exogenous B, cold stress did not repress PMCA1 in brain regions
other than hippocampus. Moreover, in the presence of constant B (B-replaced,
adrenalectomized animals), cold stress led to increased hippocampal PMCA1
expression. These observations suggest that repression of PMCA1 represents one
molecular mechanism by which corticosteroids regulate Ca(2+) homeostasis and
hence influence neuronal activity. Moreover, other stress-related neurohumoral
factors appear to counter the repressive effects of B. Defects in the balance
between GC-mediated and non-GC-mediated effects on PMCA1 expression may have
adverse effects on neuronal function and ultimately result in irreversible
neuronal damage.
PMID- 10777777
TI - Zinc-induced cortical neuronal death: contribution of energy failure attributable
to loss of NAD(+) and inhibition of glycolysis.
AB - Excessive zinc influx may contribute to neuronal death after certain insults,
including transient global ischemia. In light of evidence that levels of
intracellular free Zn(2+) associated with neurotoxicity may be sufficient to
inhibit glyceraldehyde-3-phosphate dehydrogenase (GAPDH), experiments were
performed looking for reduced glycolysis and energy failure in cultured mouse
cortical neurons subjected to lethal Zn(2+) exposure. As predicted, cultures
exposed for 3-22 hr to 40 mixroM Zn(2+) developed an early increase in levels of
dihydroxy-acetone phosphate (DHAP) and fructose 1,6-bisphosphate (FBP) and a
progressive loss of ATP levels, followed by neuronal cell death; furthermore,
addition of the downstream glycolytic substrate pyruvate to the bathing medium
attenuated the fall in ATP and neuronal death. However, an alternative to direct
Zn(2+) inhibition of GAPDH was raised by the observation that Zn(2+) exposure
also induced an early decrease in nicotinamide-adenine dinucleotide (NAD(+))
levels, an event itself capable of inhibiting GAPDH. Favoring this indirect
mechanism of GAPDH inhibition, the neuroprotective effects of pyruvate addition
were associated with normalization of cellular levels of NAD(+), DHAP, and FBP.
Zn(2+)-induced neuronal death was also attenuated by addition of the energy
substrate oxaloacetate, the activator of pyruvate dehydrogenase, dichloroacetate,
or the inhibitors of NAD(+) catabolism, niacinamide or benzamide. Acetyl
carnitine, alpha-keto butyrate, lactate, and beta-hydroxy-butyrate did not
attenuate Zn(2+)-induced neurotoxicity, perhaps because they could not regenerate
NAD(+) or be used for energy production in the presence of glucose.
PMID- 10777778
TI - Slow death of postnatal hippocampal neurons by GABA(A) receptor overactivation.
AB - Neurotransmitters can have both toxic and trophic functions in addition to their
role in neural signaling. Surprisingly, chronic blockade of GABA(A) receptor
activity for 5-8 d in vitro enhanced survival of hippocampal neurons, suggesting
that GABA(A) receptor overactivation may be neurotoxic. Potentiating GABA(A)
receptor activity by chronic treatment with the endogenous neurosteroid
(3alpha,5alpha)-3-hydroxypregnan-20-one caused massive cell loss over 1 week in
culture. Other potentiators of GABA(A) receptors, including benzodiazepines,
mimicked the cell loss, suggesting that potentiating endogenous GABA activity is
sufficient to produce neuronal death. Neurosteroid-treated neurons had lower
resting intracellular calcium levels than control cells and produced smaller
calcium rises in response to depolarizing challenges. Manipulating intracellular
calcium levels with chronic elevated extracellular potassium or with the calcium
channel agonist Bay K 8644 protected neurons. The results may have implications
for the mechanisms of programmed cell death in the developing CNS as well as
implications for the long-term consequences of chronic GABAmimetic drug use
during development.
PMID- 10777779
TI - Ethanol-associated behaviors of mice lacking norepinephrine.
AB - Although norepinephrine (NE) has been implicated in animal models of ethanol
consumption for many years, the exact nature of its influence is not clear.
Lesioning and pharmacological studies examining the role of NE in ethanol
consumption have yielded conflicting results. We took a genetic approach to
determine the effect of NE depletion on ethanol-mediated behaviors by using
dopamine beta-hydroxylase knockout (Dbh -/-) mice that specifically lack the
ability to synthesize NE. Dbh -/- males have reduced ethanol preference in a two
bottle choice paradigm and show a delay in extinguishing an ethanol-conditioned
taste aversion, suggesting that they drink less ethanol in part because they find
its effects more aversive. Both male and female Dbh -/- mice are hypersensitive
to the sedative and hypothermic effects of systemic ethanol administration, and
the sedation phenotype can be rescued pharmacologically by acute replacement of
central NE. Neither the decreased body temperature nor changes in ethanol
metabolism can explain the differences in consumption and sedation. These results
demonstrate a significant role for NE in modulating ethanol-related behaviors and
physiological responses.
PMID- 10777780
TI - Brain-derived neurotrophic factor (BDNF) induces dendritic targeting of BDNF and
tyrosine kinase B mRNAs in hippocampal neurons through a phosphatidylinositol-3
kinase-dependent pathway.
AB - This study aims to understand the mechanisms of dendritic targeting of brain
derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) mRNAs. We show
that brief depolarizations are sufficient to induce accumulation of BDNF and TrkB
mRNAs in dendrites of hippocampal neurons. Endogenous BDNF, secreted during the
KCl stimulation, contributes significantly to the dendritic accumulation of BDNF
TrkB mRNAs. In the absence of depolarization, 1 min pulses of exogenous BDNF are
sufficient to induce dendritic accumulation of BDNF-TrkB mRNAs. After binding to
TrkB, BDNF exerts this action by activating a PI-3 kinase-dependent pathway. The
accumulation of dendritic mRNA by BDNF is not mediated by BDNF-induced
neurotransmitter release. Because most hippocampal neurons coexpress BDNF and
TrkB receptors, these results show that the subcellular distribution of BDNF-TrkB
mRNAs is under the control of an autocrine-paracrine BDNF-TrkB-dependent loop.
PMID- 10777781
TI - DNA methyltransferase contributes to delayed ischemic brain injury.
AB - DNA methylation is important for controlling the profile of gene expression and
is catalyzed by DNA methyltransferase (MTase), an enzyme that is abundant in
brain. Because significant DNA damage and alterations in gene expression develop
as a consequence of cerebral ischemia, we measured MTase activity in vitro and
DNA methylation in vivo after mild focal brain ischemia. After 30 min middle
cerebral artery occlusion (MCAo) and reperfusion, MTase catalytic activity and
the 190 kDa band on immunoblot did not change over time. However, [(3)H]methyl
group incorporation into DNA increased significantly in wild-type mice after
reperfusion, but not in mutant mice heterozygous for a DNA methyltransferase gene
deletion (Dnmt(S/+)). Dnmt(S/+) mice were resistant to mild ischemic damage,
suggesting that increased DNA methylation is associated with augmented brain
injury after MCA occlusion. Consistent with this formulation, treatment with the
MTase inhibitor 5-aza-2'-deoxycytidine and the deacetylation inhibitor
trichostatin A conferred stroke protection in wild-type mice. In contrast to mild
stroke, however, DNA methylation was not enhanced, and reduced dnmt gene
expression was not protective in an ischemia model of excitotoxic/necrotic cell
death. In conclusion, our results demonstrate that MTase activity contributes to
poor tissue outcome after mild ischemic brain injury.
PMID- 10777782
TI - Glial cell line-derived neurotrophic factor is essential for postnatal survival
of midbrain dopamine neurons.
AB - Glial cell line-derived neurotrophic factor (GDNF) is one of the most potent
trophic factors that have been identified for midbrain dopamine (DA) neurons.
Null mutations for trophic factor genes have been used frequently for studies of
the role of these important proteins in brain development. One problem with these
studies has been that often only prenatal development can be studied because many
of the knockout strains, such as those with GDNF null mutations, will die shortly
after birth. In this study, we looked at the continued fate of specific neuronal
phenotypes from trophic factor knockout mice beyond the time that these animals
die. By transplanting fetal neural tissues from GDNF -/-, GDNF +/-, and wild-type
(WT) mice into the brain of adult wild-type mice, we demonstrate that the
continued postnatal development of ventral midbrain dopamine neurons is severely
disturbed as a result of the GDNF null mutation. Ventral midbrain grafts from -/-
fetuses have markedly reduced DA neuron numbers and fiber outgrowth. Moreover, DA
neurons in such transplants can be "rescued" by immersion in GDNF before
grafting. These findings suggest that postnatal survival and/or phenotypic
expression of ventral mesencephalic DA neurons is dependent on GDNF. In addition,
we present here a strategy for studies of maturation and even aging of tissues
from trophic factor and other knockout animals that do not survive past birth.
PMID- 10777783
TI - Protein aggregation after transient cerebral ischemia.
AB - Protein aggregates containing ubiquitinated proteins are commonly present in
neurodegenerative disorders and have been considered to cause neuronal
degeneration. Here, we report that transient cerebral ischemia caused severe
protein aggregation in hippocampal CA1 neurons. By using ethanolic
phosphotungstic acid electron microscopy (EM) and ubiquitin immunogold EM, we
found that protein aggregates were accumulated in CA1 neurons destined to die 72
hr after 15 min of cerebral ischemia. Protein aggregates appeared as clumps of
electron-dense materials that stained heavily for ubiquitin and were associated
with various intracellular membranous structures. The protein aggregates appeared
at 4 hr and progressively accumulated at 24 and 48 hr of reperfusion in CA1 dying
neurons. However, they were rarely observed in dentate gyrus neurons that were
resistant to ischemia. At 4 hr of reperfusion, protein aggregates were mainly
associated with intracellular vesicles in the soma and dendrites, and the nuclear
membrane. By 24 hr of reperfusion, the aggregates were also associated with
mitochondria, the Golgi apparatus, and the dendritic plasmalemma. High-resolution
confocal microscopy further demonstrated that protein aggregates containing
ubiquitin were persistently and progressively accumulated in all CA1 dying
neurons but not in neuronal populations that survive in this model. We conclude
that proteins are severely aggregated in hippocampal neurons vulnerable to
transient brain ischemia. We hypothesize that the accumulation of protein
aggregates cause ischemic neuronal death.
PMID- 10777784
TI - Agonist- and reflex-evoked internalization of metabotropic glutamate receptor 5
in enteric neurons.
AB - We demonstrate that metabotropic glutamate receptor 5 (mGluR5) is present in the
guinea pig ileum. A punctate ring-like distribution of immunoreactivity is found
on the soma of a subset of neurons, consistent with an association of mGluR5 with
the plasma membrane. mGluR5-containing cells in the submucosal plexus are
predominantly noncholinergic and contain vasoactive intestinal peptide, a marker
of secretomotor neurons. Using immunocytochemistry in conjunction with confocal
microscopy, we show that the mGluR5 undergoes agonist- and reflex-evoked
internalization that is inhibited by the group I antagonist 1-aminoindan-1,5
dicarboxylic acid. In addition, group I mGluR antagonists reduce the distension
induced phosphorylation of cAMP-responsive element-binding protein in enteric
neurons and attenuate both glutamate- and group I agonist-induced depolarizing
responses and slow synaptic events in submucosal neurons. These findings support
the idea that mGluRs play a role in enteric reflexes and suggest that
internalization might be a major mechanism for regulation of mGluR activity.
PMID- 10777785
TI - Molecular cloning of a novel membrane glycoprotein, pal, specifically expressed
in photoreceptor cells of the retina and containing leucine-rich repeat.
AB - We have isolated a novel retina-specific gene in a screen for genes of which
expression is not apparent neonatally in rat retina but is abundant postnatally
on day 14 (P14). This gene, named Pal, encodes a putative type I transmembrane
protein containing five leucine-rich repeats (LRRs), a single C2-type Ig-like
domain, and a single fibronectin type III domain and is considered to be a new
member of the LRR and Ig superfamily. No expression of Pal was found in rat
retina at P1, but it was detected at P7 and markedly increased with subsequent
development. These expression patterns of Pal appeared to be correlated with the
development of the photoreceptor outer segments, because in the adult rat retina
it was specifically localized in these segments. Ultrastructually, Pal
immunoreactivity was distributed diffusely on the disk membrane in the lamellar
regions. On the basis of its structural features and localization pattern, Pal
may act as a receptor for a certain trophic factor or for an adhesion molecule
participating in morphogenesis. The human homolog of Pal was mapped to chromosome
10q23.2-23.3 using fluorescence in situ hybridization.
PMID- 10777786
TI - Synucleins are developmentally expressed, and alpha-synuclein regulates the size
of the presynaptic vesicular pool in primary hippocampal neurons.
AB - alpha-, beta-, and gamma-Synuclein, a novel family of neuronal proteins, has
become the focus of research interest because alpha-synuclein has been
increasingly implicated in the pathogenesis of Parkinson's and Alzheimer's
disease. However, the normal functions of the synucleins are still unknown. For
this reason, we characterized alpha-, beta-, and gamma-synuclein expression in
primary hippocampal neuronal cultures and showed that the onset of alpha- and
beta-synuclein expression was delayed after synaptic development, suggesting that
these synucleins may not be essential for synapse formation. In mature cultured
primary neurons, alpha- and beta-synuclein colocalized almost exclusively with
synaptophysin in the presynaptic terminal, whereas little gamma-synuclein was
expressed at all. To assess the function of alpha-synuclein, we suppressed
expression of this protein with antisense oligonucleotide technology.
Morphometric ultrastructural analysis of the alpha-synuclein antisense
oligonucleotide-treated cultures revealed a significant reduction in the distal
pool of synaptic vesicles. These data suggest that one function of alpha
synuclein may be to regulate the size of distinct pools of synaptic vesicles in
mature neurons.
PMID- 10777787
TI - Brain-derived neurotrophic factor differentially regulates excitatory and
inhibitory synaptic transmission in hippocampal cultures.
AB - Brain-derived neurotrophic factor (BDNF) has been postulated to be a key
signaling molecule in regulating synaptic strength and overall circuit activity.
In this context, we have found that BDNF dramatically increases the frequency of
spontaneously initiated action potentials in hippocampal neurons in dissociated
culture. Using analysis of unitary synaptic transmission and immunocytochemical
methods, we determined that chronic treatment with BDNF potentiates both
excitatory and inhibitory transmission, but that it does so via different
mechanisms. BDNF strengthens excitation primarily by augmenting the amplitude of
AMPA receptor-mediated miniature EPSCs (mEPSCs) but enhances inhibition by
increasing the frequency of mIPSC and increasing the size of GABAergic synaptic
terminals. In contrast to observations in other systems, BDNF-mediated increases
in AMPA-receptor mediated mEPSC amplitudes did not require activity, because
blocking action potentials with tetrodotoxin for the entire duration of BDNF
treatment had no effect on the magnitude of this enhancement. These forms of
synaptic regulations appear to be a selective action of BDNF because intrinsic
excitability, synapse number, and neuronal survival are not affected in these
cultures. Thus, although BDNF induces a net increase in overall circuit activity,
this results from potentiation of both excitatory and inhibitory synaptic drive
through distinct and selective physiological mechanisms.
PMID- 10777788
TI - Selective presynaptic propagation of long-term potentiation in defined neural
networks.
AB - Induction of long-term potentiation (LTP) of the synaptic connection between two
hippocampal glutamatergic neurons in a neural network formed in cell culture
resulted in a specific pattern of potentiation at other connections within the
network. We found that potentiation propagated from the site of induction
retrogradely to glutamatergic or GABAergic synapses received by the dendrites of
the presynaptic neuron and laterally to those made by its axonal collaterals onto
other glutamatergic cells. In contrast, synapses made by the same presynaptic
neuron onto GABAergic cells were not affected, and there was no postsynaptic
lateral or forward propagation to other synapses received or made by the
postsynaptic neuron. In addition, there was no secondary propagation to synapses
not directly associated with the presynaptic neuron. Both induction and
propagation of LTP required correlated spiking of the postsynaptic cell as well
as the activation of the NMDA subtype of glutamate receptors. Such selective
propagation suggests the existence of a long-range cytoplasmic signaling within
the presynaptic neuron, leading to a specific pattern of coordinated potentiation
along excitatory pathways in a neural network.
PMID- 10777789
TI - Intrinsic bias and lineage restriction in the phenotype determination of dopamine
and neuropeptide Y amacrine cells.
AB - Blastomere lineages are differentially biased to produce different
neurotransmitter subtypes of amacrine cells (Huang and Moody, 1995, 1997,). To
elucidate when this bias is acquired, we examined amacrine lineages at different
early developmental times. Our experiments demonstrate that the bias to express
dopamine and neuropeptide Y amacrine fates involves several steps before the
formation of the definitive optic cup. At cleavage stages, a retinal progenitor
that contributes large numbers of cells is already biased to produce its normal
repertoire of dopamine amacrine cells, as revealed by transplantation to a new
location, whereas the amacrine fate of a progenitor that contributes fewer cells
is modified by its new position. At neural plate stages, not all retinal
progenitors are multipotent. Nearly one-half populate only the inner nuclear
layer and are enriched in amacrine cells. During early optic vesicle stages, an
appropriate mitotic tree is required for dopamine and neuropeptide Y, but not
serotonin, amacrine cell clusters to form. Thus, the acquisition of amacrine fate
bias involves intrinsic maternal factors at cleavage, fate restriction in the
neural plate, and specified mitotic patterns in the optic vesicle. At each of
these steps only a subset of the embryonic retinal progenitors contributing to
amacrine subtypes is biased; the remaining progenitors maintain multipotency.
Thus, from the earliest embryonic stages, progenitors of the retina are a dynamic
mosaic. This is the first experimental demonstration of amacrine fate decisions
that occur during early embryonic periods in advance of the events described in
the later, committed retina.
PMID- 10777790
TI - c-Raf regulates cell survival and retinal ganglion cell morphogenesis during
neurogenesis.
AB - The signaling cascade Ras/Raf/mitogen-activated protein kinases modulates cell
proliferation, differentiation, and survival, all key cellular processes during
neural development. To better define the in vivo role of Raf during chick retinal
neurogenesis, we interfered with Raf-dependent signaling during days 4.5 to 7.5
of embryonic development by expressing a dominant negative mutant of c-Raf
(DeltaRaf), which blocks Ras-dependent Raf activation, and by overexpressing wild
type c-Raf. DeltaRaf expression induced an increase in cell death by apoptosis,
whereas it did not affect overall cell proliferation and differentiation. In
parallel, the number of Islet-1/2-positive and TUJ1-positive retinal ganglion
cells were diminished in their definitive layer, whereas there was an increase in
the number of mislocated Islet-1/2-positive cells. This disturbed morphogenesis
correlated with a disruption of the optic fiber layer. Conversely, c-Raf
overexpression caused moderate opposite effects on apoptosis. These results frame
in vivo early neurogenesis processes in which c-Raf is essential.
PMID- 10777791
TI - Laminar distribution of neurons in extrastriate areas projecting to visual areas
V1 and V4 correlates with the hierarchical rank and indicates the operation of a
distance rule.
AB - The directionality of corticocortical projections is classified as feedforward
(going from a lower to higher hierarchical levels), feedback (interconnecting
descending levels), and lateral (interconnecting equivalent levels).
Directionality is determined by the combined criteria of the laminar patterns of
the axon terminals as well as the cells of origins and has been used to construct
models of the visual system, which reveals a strict hierarchical organization
(Felleman and Van Essen, 1991; Hilgetag et al., 1996a). However, these models are
indeterminate partly because we have no indication of the distance separating
adjacent levels. Here we have attempted to determine a graded parameter
describing the anatomical relationship of interconnected areas. We have
investigated whether the precise percentage of labeled supragranular layer
neurons (SLN%) in each afferent area after injection in either visual areas V1 or
V4 determines its hierarchical position in the model. This shows that pathway
directionality in the Felleman and Van Essen model is characterized by a range of
SLN% values. The one exception is the projection of the frontal eye field to area
V4, which resembles a feedforward projection. Individual areal differences in
SLN% values are highly significant, and the number of hierarchical steps
separating a target area from a source area is found to be tightly correlated to
SLN%. The present results show that the hierarchical rank of each afferent area
is reliably indicated by SLN%, and therefore this constitutes a graded parameter
that is related to hierarchical distance.
PMID- 10777792
TI - A spatiotemporal wave of turnover and functional maturation of olfactory receptor
neurons in the spiny lobster Panulirus argus.
AB - Olfactory receptor neurons (ORNs) of crustaceans are housed in aesthetasc
sensilla that are located on the lateral flagellum of the antennule. We used
young adult spiny lobsters to examine turnover of aesthetascs and functional
maturation of their ORNs after molting. The proliferation zone for new
aesthetascs is located in the proximal part of the aesthetasc-bearing region and
progressively moves along a distoproximal axis. Older aesthetascs are lost in the
distal part of the aesthetasc-bearing region. As a result, an aesthetasc may be
shed three to six molts after it differentiates. Taurine-like immunoreactivity is
elevated in ORNs of aesthetascs that have yet to emerge on the cuticular surface
and thereafter decreases gradually and asynchronously. ORNs from the distalmost
developing aesthetascs lose taurine-like immunoreactivity immediately before
sensillar emergence, whereas ORNs from the most proximal and lateral new
aesthetascs retain taurine-like immunoreactivity throughout the intermolt stage
after sensillar emergence. Furthermore, taurine-like immunoreactivity is
inversely correlated with odor responsiveness. These results suggest that taurine
like immunoreactivity reveals immature ORNs and that their functional maturation
is not synchronized with molting and may not be completed until many weeks after
sensillar emergence. Our data suggest successive spatiotemporal waves of birth,
differentiation and functional maturation, and death of ORNs.
PMID- 10777793
TI - Activation of intrinsic afferent pathways in submucosal ganglia of the guinea pig
small intestine.
AB - The enteric nervous system contains intrinsic primary afferent neurons that allow
mucosal stimulation to initiate reflexes without CNS input. We tested the
hypothesis that submucosal primary afferent neurons are activated by 5
hydroxytryptamine (5-HT) released from the stimulated mucosa. Fast and/or slow
EPSPs were recorded in submucosal neurons after the delivery of exogenous 5-HT,
WAY100325 (a 5-HT(1P) agonist), mechanical, or electrical stimuli to the mucosa
of myenteric plexus-free preparations (+/- extrinsic denervation). These events
were responses of second-order cells to transmitters released by excited primary
afferent neurons. After all stimuli, fast and slow EPSPs were abolished by a 5
HT(1P) antagonist, N-acetyl-5-hydroxytryptophyl-5-hydroxytryptophan amide, and by
1.0 microM tropisetron, but not by 5-HT(4)-selective antagonists (SB204070 and
GR113808A) or 5-HT(3)-selective antagonists (ondansetron and 0.3 microM
tropisetron). Fast EPSPs in second-order neurons were blocked by hexamethonium,
and most slow EPSPs were blocked by an antagonist of human calcitonin gene
related peptide (hCGRP(8-37)). hCGRP(8-37) also inhibited the spread of
excitation in the submucosal plexus, assessed by measuring the uptake of FM2-10
and induction of c-fos. In summary, data are consistent with the hypothesis that
5-HT from enterochromaffin cells in response to mucosal stimuli initiates
reflexes by stimulating 5-HT(1P) receptors on submucosal primary afferent
neurons. Second-order neurons respond to these cholinergic/CGRP-containing cells
with nicotinic fast EPSPs and/or CGRP-mediated slow EPSPs. Slow EPSPs are
necessary for excitation to spread within the submucosal plexus. Because some
second-order neurons contain also CGRP, primary afferent neurons may be
multifunctional and also serve as interneurons.
PMID- 10777794
TI - Cortical regions involved in perceiving object shape.
AB - The studies described here use functional magnetic resonance imaging to test
whether common or distinct cognitive and/or neural mechanisms are involved in
extracting object structure from the different image cues defining an object's
shape, such as contours, shading, and monocular depth cues. We found overlapping
activations in the lateral and ventral occipital cortex [known as the lateral
occipital complex (LOC)] for objects defined by different visual cues (e.g.,
grayscale photographs and line drawings) when each was compared with its own
scrambled-object control. In a second experiment we found a reduced response when
objects were repeated, independent of whether they appeared in the same or a
different format (i.e., grayscale images vs line drawings). A third experiment
showed that activation in the LOC was no stronger for three-dimensional shapes
defined by contours or monocular depth cues, such as occlusion, than for two
dimensional shapes, suggesting that these regions are not selectively involved in
processing three-dimensional shape information. These results suggest that common
regions in the LOC are involved in extracting and/or representing information
about object structure from different image cues.
PMID- 10777795
TI - Cuneiform neurons activated during cholinergically induced active sleep in the
cat.
AB - In the present study, we report that the cuneiform (Cun) nucleus, a brainstem
structure that before now has not been implicated in sleep processes, exhibits a
large number of neurons that express c-fos during carbachol-induced active sleep
(AS-carbachol). Compared with control (awake) cats, during AS-carbachol, there
was a 671% increase in the number of neurons that expressed c-fos in this
structure. Within the Cun nucleus, three immunocytochemically distinct
populations of neurons were observed. One group consisted of GABAergic neurons,
which predominantly did not express c-fos during AS-carbachol. Two other
different populations expressed c-fos during this state. One of the Fos-positive
(Fos(+)) populations consisted of a distinct group of nitric oxide synthase (NOS)
NADPH-diaphorase (NADPH-d)-containing neurons; the neurotransmitter of the other
Fos(+) population remains unknown. The Cun nucleus did not contain cholinergic,
catecholaminergic, serotonergic, or glycinergic neurons. On the basis of neuronal
activation during AS-carbachol, as indicated by c-fos expression, we suggest that
the Cun nucleus is involved, in an as yet unknown manner, in the physiological
expression of active sleep. The finding of a population of NOS-NADPH-d containing
neurons, which were activated during AS-carbachol, suggests that nitrergic
modulation of their target cell groups is likely to play a role in active sleep
related physiological processes.
PMID- 10777796
TI - New insights into the hemodynamic blood oxygenation level-dependent response
through combination of functional magnetic resonance imaging and optical
recording in gerbil barrel cortex.
AB - Fast, low-angle shoot functional magnetic resonance imaging (fMRI), based on the
blood oxygenation level-dependent (BOLD) effect, was combined with optical
recording of intrinsic signals (ORIS) and 2-deoxyglucose labeling in gerbil
barrel cortex. We observed over the activated barrel a positive BOLD signal and
increased levels of deoxyhemoglobin and total hemoglobin during each period of
prolonged (30 sec) D2 vibrissal stimulation. These data show that the hemodynamic
basis of this fMRI signal is not necessarily a washout of deoxyhemoglobin, as
generally assumed. Instead, they suggest that a positive BOLD signal can also be
caused by a local increase of blood volume, even if deoxyhemoglobin levels are
persistently elevated. We also show that this alternative interpretation is
consistent with theoretical models of the BOLD signal. The changes in BOLD signal
and blood volume, which are most tightly correlated with the periodic
stimulation, peak at the site of neuronal activation. These results contribute to
the understanding of the hemodynamic mechanisms underlying the BOLD signal and
also suggest analysis methods, which improve the spatial localization of neuronal
activation with both fMRI and ORIS.
PMID- 10777797
TI - Ectopic expression of the neuropeptide pigment-dispersing factor alters
behavioral rhythms in Drosophila melanogaster.
AB - To study the function of the neuropeptide pigment-dispersing factor (PDF) in the
circadian system of Drosophila, we misexpressed the pdf gene from the grasshopper
Romalea in the CNS of Drosophila and investigated the effect of this on
behavioral rhythmicity. pdf was either ectopically expressed in different numbers
of neurons in the brain or the thoracical nervous system or overexpressed in the
pacemaker neurons alone. We found severe alterations in the activity and eclosion
rhythm of several but not all lines with ectopic pdf expression. Only ectopic pdf
expression in neurons that projected into the dorsal central brain severely
influenced activity rhythms. Therefore, we conclude that PDF acts as a
neuromodulator in the dorsal central brain that is involved in the rhythmic
control of behavior. Overexpression of pdf in the pacemaker neurons alone or in
the other neurons that express the clock genes period (per) and timeless (tim)
did not disturb the activity rhythm. Such flies still showed a rhythm in PDF
accumulation in the central brain terminals. This rhythm was absent in the
terminals of neurons that expressed PDF ectopically. Probably, PDF is
rhythmically processed, transported, or secreted in neurons expressing per and
tim, and additional PDF expression in these cells does not influence this
rhythmic process. In neurons lacking per and tim, PDF appears to be continuously
processed, leading to a constant PDF secretion at their nerve terminals. This may
lead to conflicting signals in the rhythmic output pathway and result in a
severely altered rhythmic behavior.
PMID- 10777798
TI - Novel hippocampal interneuronal subtypes identified using transgenic mice that
express green fluorescent protein in GABAergic interneurons.
AB - The chief inhibitory neurons of the mammalian brain, GABAergic neurons, are
comprised of a myriad of diverse neuronal subtypes. To facilitate the study of
these neurons, transgenic mice were generated that express enhanced green
fluorescent protein (EGFP) in subpopulations of GABAergic neurons. In one of the
resulting transgenic lines, called GIN (GFP-expressing Inhibitory Neurons), EGFP
was found to be expressed in a subpopulation of somatostatin-containing GABAergic
interneurons in the hippocampus and neocortex. In both live and fixed brain
preparations from these mice, detailed microanatomical features of EGFP
expressing interneurons were readily observed. In stratum oriens of the
hippocampus, EGFP-expressing interneurons were comprised almost exclusively of
oriens/alveus interneurons with lacunosum-moleculare axon arborization (O-LM
cells). In the neocortex, the somata of EGFP-expressing interneurons were largely
restricted to layers II-IV and upper layer V. In hippocampal area CA1, two
previously uncharacterized subtypes of interneurons were identified using the GIN
mice: stratum pyramidale interneurons with lacunosum-moleculare axon arborization
(P-LM cells) and stratum radiatum interneurons with lacunosum-moleculare axon
arborization (R-LM cells). These newly identified interneuronal subtypes appeared
to be closely related to O-LM cell, as they selectively innervate stratum
lacunosum-moleculare. Whole-cell patch-clamp recordings revealed that these cells
were fast-spiking and showed virtually no spike frequency accommodation. The
microanatomical features of these cells suggest that they function primarily as
"input-biasing" neurons, in that synaptic volleys in stratum radiatum would lead
to their activation, which in turn would result in selective suppression of
excitatory input from the entorhinal cortex onto CA1 pyramidal cells.
PMID- 10777799
TI - Classical conditioning of feeding in Aplysia: I. Behavioral analysis.
AB - A training protocol was developed to classically condition feeding behavior in
Aplysia californica using tactile stimulation of the lips as the conditional
stimulus (CS) and food as the unconditional stimulus (US). Paired training
induced a greater increase in the number of bites to the CS than unpaired
training or US-only stimulation. Memory for classical conditioning was retained
for at least 24 hr. The organization of the reinforcement pathway that supports
classical conditioning was analyzed in additional behavioral experiments. No
evidence was found for the contribution to appetitive reinforcement of US
mediating pathways originating in the lips of the animals. Bilateral lesions of
the anterior branch of the esophageal nerve, which innervates parts of the
foregut, however, were found to attenuate classical conditioning. Thus, it
appears likely that reinforcement during appetitive classical conditioning of
feeding was mediated by afferent pathways that originate in the foregut. The
companion paper () describes two neurophysiological correlates of the classical
conditioning.
PMID- 10777800
TI - Classical conditioning of feeding in Aplysia: II. Neurophysiological correlates.
AB - Feeding behavior in Aplysia californica can be classically conditioned using
tactile stimulation of the lips as conditional stimulus (CS) and food as
unconditional stimulus (US) [ (companion paper)]. Conditioning resulted in an
increase in the number of CS-evoked bites that persisted for at least 24 hr after
training. In this study, neurophysiological correlates of classical conditioning
training were identified and characterized in an in vitro preparation of the
cerebral and buccal ganglia. Stimulation of a lip nerve (AT(4)), which mediates
mechanosensory information, resulted in a greater number of buccal motor patterns
(BMPs) in ganglia isolated from animals that had received paired training than in
ganglia from control animals. The majority of the evoked BMPs were classified as
ingestion-like patterns. Intracellular recordings from pattern-initiating neuron
B31/32 revealed that stimulation of AT(4) evoked greater excitatory input in
B31/32 in preparations from animals that had received paired training than from
control animals. In contrast, excitatory input to buccal neuron B4/5 in response
to stimulation of AT(4) was not significantly increased by paired training.
Moreover, correlates of classical conditioning were specific to stimulation of
AT(4). The number of spontaneously occurring BMPs and the intrinsic properties of
two buccal neurons (B4/5 and B31/32) did not differ between groups. These results
suggest that appetitive classical conditioning of feeding resulted in the pairing
specific strengthening of the polysynaptic pathway between afferent fibers and
pattern-initiating neurons of the buccal central pattern generator.
PMID- 10777801
TI - The precision of single neuron responses in cortical area V1 during stereoscopic
depth judgments.
AB - The performance of single neurons in cortical area V1 of alert macaque monkeys
was compared against the animals' psychophysical performance during a binocular
disparity discrimination task. Performance was assessed with stimuli that
consisted of a patch of dynamic random dots, whose disparity varied from trial to
trial, surrounded by an annulus of similar dots at a fixed disparity. On each
trial, the animals indicated whether the depth of the central patch was in front
of or behind the annulus. For each disparity of the center patch, neural
performance was assessed by calculating the probability that the response of the
neuron was greater or less than the response when the center disparity was the
same as that of the annulus. Initially the animals performed the task
simultaneously with the neural recording. However, the range of disparities used,
which was appropriate for the neuronal recording, may have affected performance,
because the thresholds were substantially lower (2.6x) when the psychophysical
measurements were repeated later. Average neuronal thresholds were approximately
4x poorer than these behavioral thresholds, although the best neurons were
marginally better than the animals' behavior. Thus, the well known precision of
relative depth judgments can be supported with signals from a small number of V1
neurons. Interference with the relative depth information in the stimulus
profoundly affected behavioral thresholds, which were approximately 10x poorer
when the surround was absent or contained binocularly uncorrelated dots. In this
case, single V1 neurons consistently outperform the observer: presumably here,
psychophysical thresholds are limited by other factors (such as uncertainty about
vergence eye position).
PMID- 10777802
TI - Reversal of dopamine D(2) receptor responses by an anandamide transport
inhibitor.
AB - We characterized the pharmacological properties of the anandamide transport
inhibitor N-(4-hydroxyphenyl)-arachidonamide (AM404) in rats and investigated the
effects of this drug on behavioral responses associated with activation of
dopamine D(2) family receptors. Rat brain slices accumulated [(3)H]anandamide via
a high-affinity transport mechanism that was blocked by AM404. When administered
alone in vivo, AM404 caused a mild and slow-developing hypokinesia that was
significant 60 min after intracerebroventricular injection of the drug and was
reversed by the CB1 cannabinoid receptor antagonist SR141716A. AM404 produced no
significant catalepsy or analgesia, two typical effects of direct-acting
cannabinoid agonists. However, AM404 prevented the stereotypic yawning produced
by systemic administration of a low dose of apomorphine, an effect that was dose
dependent and blocked by SR141716A. Furthermore, AM404 reduced the stimulation of
motor behaviors elicited by the selective D(2) family receptor agonist
quinpirole. Finally, AM404 reduced hyperactivity in juvenile spontaneously
hypertensive rats, a putative model of attention deficit hyperactivity disorder.
The results support a primary role of the endocannabinoid system in the
regulation of psychomotor activity and point to anandamide transport as a
potential target for neuropsychiatric medicines.
PMID- 10777803
TI - Coregulation of voltage-dependent kinetics of Na(+) and K(+) currents in electric
organ.
AB - The electric organ cells of Sternopygus generate action potentials whose
durations vary over a fourfold range. This variation in action potential duration
is the basis for individual variation in a communication signal. Thus, action
potential duration must be precisely regulated in these cells. We had observed
previously that the inactivation kinetics of the electrocyte Na(+) current show
systematic individual variation. In this study, using a two-electrode voltage
clamp, we found that the voltage-dependent activation and deactivation kinetics
of the delayed rectifying K(+) current in these cells covary in a graded and
predictable manner across fish. Furthermore, when Na(+) and K(+) currents were
recorded in the same cell, their voltage-dependent kinetics were highly
correlated. This finding illustrates an unprecedented degree of coregulation of
voltage-dependent properties in two molecularly distinct ionic channels. Such a
coregulation of ionic channels is uniquely observable in a cell specialized to
generate individual differences in electrical activity and in which the results
of biophysical control mechanisms are evident in behaving animals. We propose
that the precise coregulation of the voltage-dependent kinetics of multiple ionic
currents may be a general mechanism for regulation of membrane excitability.
PMID- 10777804
TI - A role for complement in the rejection of porcine ventral mesencephalic
xenografts in a rat model of Parkinson's disease.
AB - Vascularized whole organ discordant xenografts placed in the periphery are
rejected by a rapid "hyperacute" process that involves preformed antibody binding
to the xeno-antigens on the donor endothelial cells with complement activation.
In the CNS, xenografts are classically thought to be rejected more slowly by a T
cell-dependent process. We now report that xenografts of embryonic porcine
ventral mesencephalic tissue in the 6-hydroxydopamine-lesioned,
nonimmunosuppressed rat induce both a humoral and a cell-mediated response. Over
the first 10 d after implantation, the xenografts matured with identifiable TH
neurons and pig-specific neurofilament fibers extending along host white matter
tracts. During this period of time, IgM and complement binding were observed
within the graft, as well as a CD8 cellular infiltrate, leading to rejection of
the transplant over the next 25 d. These intracerebral xenografts were not
associated with an early systemic antibody response. A role for complement in
this rejection process was further investigated using cobra venom factor (CVF),
which systemically depleted the rats of complement for 7 d. CVF treatment, when
given in the period immediately before and after grafting, delayed but did not
prevent the cellular immune response induced by the graft, demonstrating that
xenografted neural tissue can activate the humoral arm of the rejection process,
in particular the complement cascade. This suggests that interventions targeting
this aspect of the immune rejection process may be of great importance for the
future development of xenotransplantation for neurodegenerative conditions.
PMID- 10777805
TI - The genetic variant Voila causes gustatory defects during Drosophila development.
AB - Voila(1), an enhancer-trap strain in Drosophila melanogaster, expresses GAL4 in
most gustatory neurons, both before and after metamorphosis. Voila(1) expression
starts at embryonic stage 10. In the periphery, it labels larval gustatory
sensilla in the antennomaxillary complex as well as in the pharynx. GAL4 is also
expressed in the CNS in a manner that prefigures expression in adult flies. Most
Voila(1/1) homozygotes die between second larval instar and early adulthood.
Moreover, escaping Voila(1/1) larvae do not show gustatory responses to NaCl and
sucrose. The simultaneous rescue of normal larval gustation together with adult
viability after removal of the transposable PGAL4 element suggests that both
these phenotypes are caused by the same inserted element.
PMID- 10777806
TI - Metaplasticity of mossy fiber synaptic transmission involves altered release
probability.
AB - Activity-dependent synaptic plasticity is a fundamental feature of CNS synapses.
Intriguingly, the capacity of synapses to express plastic changes is itself
subject to considerable activity-dependent variation, or metaplasticity. These
forms of higher order plasticity are important because they may be crucial to
maintain synapses within a dynamic functional range. In this study, we asked
whether neuronal activity induced in vivo by application of kainate can induce
lasting changes in mossy fiber short- and long-term plasticity. Several weeks
after kainate-induced status epilepticus, the mossy fiber, but not the
associational-commissural pathway, exhibits a marked loss of paired-pulse
facilitation, augmentation, and long-term potentiation (LTP). Because the
adenylyl cyclase-protein kinase A cascade is involved in mossy fiber LTP
induction, we have tested the integrity of this key pathway by pharmacological
activation of either adenylyl cyclase or protein kinase A. These treatments
resulted in LTP in control, but not in kainate-treated animals, indicating that
status-induced changes occur downstream of protein kinase A. To test whether
altered neurotransmitter release might account for these changes, we measured the
size of the releasable pool of glutamate in mossy fiber terminals. We find that
the size of the releasable pool of glutamate was significantly increased in
kainate-treated rats, indicating an increased release probability at the mossy
fiber-CA3 synapse. Therefore, we suggest that lasting changes in neurotransmitter
release probability caused by neuronal activity may be a powerful mechanism for
metaplasticity that modulates both short- and long-term plasticity in the mossy
fiber-CA3 synapse after status epilepticus.
PMID- 10777807
TI - A novel selective melanocortin-4 receptor agonist reduces food intake in rats and
mice without producing aversive consequences.
AB - Studies using nonselective agonists and antagonists of melanocortin-3 receptor
(MC3R) and MC4R point to the importance of the CNS melanocortin system in the
control of food intake. We describe here a novel compound that is highly
selective as an agonist at the MC4 receptor but has minimal activity at the MC3
receptor. When administered centrally to rats, this selective agonist increased
Fos-like immunoreactivity in the paraventricular nucleus, central nucleus of the
amygdala, nucleus of the solitary tract, and area postrema, a pattern of neuronal
activation that is similar to that induced by a nonselective MC3/4R agonist.
Additionally, it suppresses food intake when administered centrally to rats or
peripherally to db/db mice that lack functional leptin receptors via a mechanism
that is not accompanied by illness or other nonspecific effects. Conversely, a
related compound that is a selective MC4R antagonist potently increased food
intake when administered centrally in rats. These results support the hypothesis
that the brain MC4R is intimately involved in the control of food intake and body
weight and provide evidence that selective activation of MC4R causes anorexia
that is not secondary to aversive effects.
PMID- 10777808
TI - Extraretinal control of saccadic suppression.
AB - We measured the time course of saccadic suppression and tested whether
suppression results entirely from retinal image motion or has an extraretinal
source. We measured contrast thresholds for low-frequency gratings modulated
either in luminance, at 17 cd/m(2) and 0.17 cd/m(2), or color at 17 cd/m(2).
Gratings were flashed on a uniform background before, during, or after voluntary
12 degrees saccades and, additionally in the case of luminance modulated
gratings, saccades simulated by mirror motion. A 10-fold decrease in contrast
sensitivity was found for luminance-modulated gratings with saccades, but little
suppression was found with simulated saccades. Adding high-contrast noise to the
display increased the magnitude and the duration of the suppression during
simulated saccades but had little effect on suppression produced by real
saccades. Suppression anticipates saccades by 50 msec, is maximal at the moment
of saccadic onset, and outlasts saccades by approximately 50 msec. At lower
luminance, suppression is reduced, and its course is shallower than at higher
luminance. Simulated saccades produce shallower suppression over a longer time
course at both luminances. No suppression was found for chromatically modulated
gratings. Differences between real and simulated saccades in the magnitude and
time course of sensitivity loss suggest that saccadic suppression has an
extraretinal component. We model the effects of saccades by adding a signal to
the visual input, so as to saturate the nonlinear stage of visual processing and
make detection of a test stimulus more difficult.
PMID- 10777809
TI - Role of microglial-derived tumor necrosis factor in mediating CD14 transcription
and nuclear factor kappa B activity in the brain during endotoxemia.
AB - Systemic injection of the endotoxin lipopolysaccharide (LPS) upregulates the gene
encoding CD14 early in the circumventricular organs (CVOs) and later in the brain
parenchyma. The present study tested the hypothesis that the parenchymal
production of the proinflammatory cytokine tumor necrosis factor alpha (TNF
alpha) by microglial cells is responsible for triggering CD14 transcription in an
autocrine/paracrine loop-like manner. In a first set of experiments, Sprague
Dawley rats were killed 1, 3, 6, and 12 hr after an intracerebroventricular
administration of recombinant rat TNF-alpha or vehicle solution. Second, anti-rat
TNF-alpha-neutralizing antibody or vehicle solution was administrated into the
lateral ventricle 10 hr before an intraperitoneal injection of LPS. Central
administration of the cytokine caused a strong induction of IkappaBalpha, TNF
alpha, and CD14 mRNA in parenchymal microglial cells. The hybridization signal
for these transcripts was localized to the edge of the ventricles and the site of
infusion. The time-related expression of each mRNA suggested that TNF-alpha has
the ability to trigger its own production followed by the transcription of the
LPS receptor; the signal for IkappaBalpha, TNF-alpha, and CD14 peaked at 1, 3,
and 6 hr, respectively. The genes encoding TNF-alpha and mCD14 were also induced
in the CVOs and within microglial cells across the brain parenchyma in response
to intraperitoneal LPS administration. This induction in parenchymal cells of the
brain was prevented in animals that received the anti-TNF-antisera
intracerebroventricularly 10 hr before the systemic treatment with the endotoxin.
The present data provide the evidence that microglial-derived TNF-alpha is
responsible for the production of the LPS receptor CD14 during endotoxemia. This
autocrine/paracrine stimulatory loop may be of great importance in controlling
the inflammatory events that take place in the CNS during innate immune response
as well as under pathological conditions.
PMID- 10777810
TI - A site of auditory experience-dependent plasticity in the neural representation
of auditory space in the barn owl's inferior colliculus.
AB - The barn owl's optic tectum contains a map of auditory space that is based, in
part, on a map of interaural time difference (ITD). Previous studies have shown
that this ITD map is shaped by auditory experience. In this study, we
investigated whether the plasticity responsible for experience-induced changes in
ITD tuning in the tectum occurs within the tectum itself or at an earlier stage
in the auditory pathway. We altered auditory experience in young owls by
implanting an acoustic filtering device in one ear that caused frequency
dependent changes in sound timing and level. We analyzed the representation of
ITD in normal and device-reared owls in two nuclei in the ascending pathway: the
external nucleus of the inferior colliculus (ICX), the primary source of
ascending auditory input to the tectum, and the lateral shell of the central
nucleus of the inferior colliculus (ICCls), the primary source of input to the
ICX. In the ICX, device rearing caused adaptive, frequency-dependent changes in
ITD tuning, as well as changes in frequency tuning. These changes in tuning were
similar to changes that occurred in the optic tectum in the same owls. In
contrast, in the ICCls, tuning for ITD and frequency was unaffected by device
rearing. The data indicate that plasticity at the level of the ICX is largely
responsible for the adaptive adjustments in ITD tuning and frequency tuning that
are observed in the optic tecta of owls raised with abnormal auditory experience.
PMID- 10777811
TI - Activity-dependent plasticity of descending synaptic inputs to spinal motoneurons
in an in vitro turtle brainstem-spinal cord preparation.
AB - An in vitro brainstem-spinal cord preparation from adult turtles was used to test
the hypothesis that descending synaptic inputs to multifunctional spinal
motoneurons (i.e., involved in respiration and locomotion) express activity
dependent depression or potentiation. The tissue was placed in a chamber that
allowed for separate superfusion of the brainstem, spinal segments C(2)-C(4), and
C(5)-D(1). Action potential conduction between the brainstem and spinal segments
C(5)-D(1) was blocked by superfusing C(2)-C(4) with Na(+)-free solution. With
C(5)-D(1) at [K(+)] = 10 mM, electrical stimulation at C(5) every 2 min evoked
potentials in intact pectoralis (expiratory, inward rotation of shoulder) and
serratus (inspiratory, outward rotation of shoulder) nerves that were stable for
at least 2 hr. Application of conditioning stimulation (900 pulses at 1 or 10 Hz)
at C(5) decreased pectoralis evoked potential amplitudes by approximately 40%
initially and by 20% after 90 min; serratus evoked potentials were unaltered.
Conditioning stimulation (100 Hz, 900 pulses) transiently depressed pectoralis
evoked potential amplitude by <20% but produced a delayed 72% increase in
serratus evoked potential amplitude after approximately 80 min. Conditioning
stimulation (10 Hz) at C(5) also reduced the amplitude of sensory afferent evoked
potentials in pectoralis produced by stimulating ipsilateral dorsal roots at
C(8). Thus, long-lasting changes in descending synaptic inputs to multifunctional
spinal motoneurons were frequency-dependent and heterosynaptic. We hypothesize
that activity-dependent plasticity may modulate descending synaptic drive to
spinal motoneurons involved in both respiration and locomotion.
PMID- 10777812
TI - Synergistically interacting dopamine D1 and NMDA receptors mediate nonvesicular
transporter-dependent GABA release from rat striatal medium spiny neurons.
AB - Given the complex interactions between dopamine D1 and glutamate NMDA receptors
in the striatum, we investigated the role of these receptors in transporter
mediated GABA release from cultured medium spiny neurons of rat striatum. Like
NMDA receptor-mediated [(3)H]-GABA release, that induced by prolonged (20 min)
dopamine D1 receptor activation was enhanced on omission of external calcium, was
action potential-independent (tetrodotoxin-insensitive), and was diminished by
the GABA transporter blocker nipecotic acid, indicating the involvement of
transporter-mediated release. Interestingly, lowering the external sodium
concentration only reduced the stimulatory effect of NMDA. Blockade of Na(+)/K(+)
ATPase by ouabain enhanced NMDA-induced but abolished dopamine-induced release.
Moreover, dopamine appeared to potentiate the effect of NMDA on [(3)H]-GABA
release. These effects of dopamine were mimicked by forskolin. mu-Opioid receptor
mediated inhibition of adenylyl cyclase by morphine reduced dopamine- and NMDA
induced release. These results confirm previous studies indicating that NMDA
receptor activation causes a slow action potential-independent efflux of GABA by
reversal of the sodium-dependent GABA transporter on sodium entry through the
NMDA receptor channel. Moreover, our data indicate that activation of G-protein
coupled dopamine D1 receptors also induces a transporter-mediated increase in
spontaneous GABA release, but through a different mechanism of action, i.e.,
through cAMP-dependent inhibition of Na(+)/K(+)-ATPase, inducing accumulation of
intracellular sodium, reversal of the GABA carrier, and potentiation of NMDA
induced release. These receptor interactions may play a crucial role in the
behavioral activating effects of psychostimulant drugs.
PMID- 10777814
TI - Cerebral asymmetry of the "top-down" allocation of attention to global and local
features.
AB - Neuropsychological and neuroimaging studies have indicated that global and local
features of a visual scene are processed differentially by the two hemispheres.
Although visual selective attention is suggested to play a role in the
hemispheric asymmetry, the precise mechanism of attentional control for the
global-local processing is not fully understood. We investigated the neural
correlates of cerebral asymmetry in directing attention to the global pattern and
local components of a hierarchical stimulus. Event-related brain potentials
(ERPs) were recorded while the subjects shifted their attention to the global or
local level of a hierarchically structured letter. The shift direction was
controlled by a preceding cue stimulus. The ERPs to the cue stimuli demonstrated
that the right temporal-parietal and left posterior temporal regions were
differentially activated during attentional allocation to the global and local
levels, respectively. These effects started 240 msec after the cue stimulus. The
late ERP components to the target stimuli also manifested the hemispheric global
local asymmetry as seen during the attentional shift. These electrophysiological
results provided an asymmetrical neural basis for the "top-down" allocation of
attention to global and local features and revealed the contribution of the
temporal-parietal cortex to this attentional mechanism.
PMID- 10777813
TI - Dual effects of D-amphetamine on dopamine neurons mediated by dopamine and
nondopamine receptors.
AB - By increasing dopamine (DA) release and activating feedback mechanisms,
amphetamine and related psychostimulants are known to inhibit DA cell firing.
Here, we report that D-amphetamine also has an excitatory effect on DA cells,
which under control conditions, is masked by the inhibitory effect of D
amphetamine and is revealed when D2-like receptors are blocked. Thus, using in
vivo single-unit recording in rats, we found that the selective D2 antagonist
raclopride not only blocked the inhibition induced by D-amphetamine but also
enabled D-amphetamine to excite DA cells. The excitation, expressed as an
increase in both firing rate and bursting, persisted when both D1- and D2-like
receptors were blocked by SCH23390 and eticlopride, suggesting that it is not
mediated by DA receptors. The norepinephrine uptake blocker nisoxetine mimicked
the effect of D-amphetamine, especially the increase in bursting, whereas the 5
HT uptake blocker fluoxetine produced no significant effect. Adrenergic alpha1
antagonists prazosin and WB4101 and the nonselective alpha antagonist
phenoxybenzamine completely blocked increase in bursting induced by D-amphetamine
and partially blocked the increase in firing rate. The alpha2 antagonist idazoxan
and the beta antagonist propranolole, however, failed to prevent D-amphetamine
from producing the excitation. Thus, revising the traditional concept, this study
suggests that D-amphetamine has two effects on DA cells, a DA-mediated inhibition
and a non-DA-mediated excitation. The latter is mediated in part through
adrenergic alpha1 receptors.
PMID- 10777815
TI - NMDA receptor activity in utero averts respiratory depression and anomalous long
term depression in newborn mice.
AB - Mutant mice lacking NMDA receptor 1 subunit (NR1) showed marked depression of
respiratory and suckling activities in vivo and overexpression of synaptic long
term depression (LTD) in a brainstem cardiorespiratory-related region (nucleus
tractus solitarius) in vitro. Pharmacological blockade of NMDA receptors in
normal newborn mice mimicked the depression in suckling activity but not
respiratory depression in vivo or brainstem LTD in vitro. Results at the
behavioral and cellular levels demonstrate that NMDA receptor deficiency during
prenatal development may unleash an anomalous form of NMDA receptor-independent
LTD along with life-threatening respiratory depression consequences in the
newborn. These findings raise the specter of cardiorespiratory dysregulation with
increased risks of morbidity and mortality in the infant as a result of premature
births or genetic or drug-induced NMDA receptor antagonism during pregnancy.
PMID- 10777816
TI - [Fungal infections in immunocompromised patients].
AB - The number of immunocompromised patients is increasing due to the intensive
therapy being administered those with cancer, organ transplant, and HIV
infection. Fungal infections are one of the important opportunistic infections in
immunocompromised patients. Early diagnosis is difficult, and the prognosis of
these patinas is usually poor. Several methods of diagnosis for fungal infections
have been developed: detection of antigens of the infected fungi from the sera is
useful for early diagnosis; polymerase chain reaction (PCR) technology may be the
most valuable method for the diagnosis of fungal infection in immunocompromised
patients, and antifungal agents are the drugs used to the fungal infections in
those patients. However, there are only five drugs available to fungal infections
in Japan. Although amphotericin B is the recommended first choice for treatment
of invasive aspergillosis, its use for immunocompromised patients is limited
because of its adverse effects. Novel antifungal agents (azoles, amphotericin B
drug deliver system, and 1,3-beta-D-glucan synthetase inhibitors) have been
developed and some of these compounds undergoing clinical trials.
PMID- 10777817
TI - [Host defense mechanisms against fungal infections].
AB - Recent advances in the research on host defense mechanisms against infections
with Candida and Aspergillus were reviewed. Modes of the defense mechanisms were
divided into three phases by thedifferent physiological circumstances surrounding
the fungi: 1, the exocrine fluid in which fungi exist on the mucosal membranes;
2, the tissues invaded by fungi with the circulating blood; and 3, the limited
lesions where fungi continue to be alive with a restricted blood flow. In each
defense mechanism, theroles of the endogenous antifungal substances such as
lactoferrin, defensins and calprotectin and leukocytes were discussed.
PMID- 10777818
TI - [A case of fixed sporotrichosis with recurred in a child following itraconazole
treatment].
AB - We report a case of fixed sporotrichosis in a 2-year-old girl who showed a
reddish nodule on her left cheek for 1 year without trauma. Fungi flora-Y
staining showed fungal elements from the exudate onthe erosion of this nodule.
Sporothrix schenckii was isolated from a culture of the fungus taken from the
biopsy specimen. Treatment with itraconazole 4.5 mg/kg/day for 16 weeks resulted
in an atrophic scar after 2.1 mg/kg/day for 8 weeks without side effects. Six
months later, her eruption recurred and wastreated with potassium iodide for 21
weeks with complete resolution. During the 1 year follow up period, there was no
recurrence. Six cases of sporotrichosis in children including ours have been
reported in Japan. Each case showed complete resolution and no recurrence.
However, careful follow-up is believed to be necessary based on our case.
PMID- 10777819
TI - [Phaeomycotic cyst caused by Phaeoacremonium parasiticum].
AB - Phaeoacremonium parasiticum was identified as the causative agent of a
phaeomycotic cyst seen just below the right knee of a 59-year-old healthy woman.
She had no history of trauma. Direct KOH examination of the pus aspirated from
the subcutaneous nodule revealed abundant mycelia, which were not too deeply
brown in color. The nodule was surgically excised, and there was no recurrence
during a half year of observation. Tissue section of the excised material
revealed rather a large cavity extending from the cutis to the subcutis. The
cavity had a thick wall composed of granulomatous tissues. Mycelial and yeast
like fungal elements were seen within the cavity and the granulomatous tissues. A
dematiaceous fungus was cultured from both pus and the excised material. The
isolates were characterized by a dark green to black colony, unbranched or
infrequently branched, brownish conidiophores bearing an aculeate monophialide
with a narrow funnel-shaped collarette, and slimy, hyaline, one-celled, ellipsoid
to allantoid conidia.
PMID- 10777820
TI - [Suppressive effects of lanoconazole on arthus phenomenon in vivo and on
production and functions of TNF in vitro].
AB - The anti-inflammatory effect of lanoconazole (LCZ) was investigated in vivo and
in vitro. The effect of LCZ was evaluated on the inflammatory reactions elicited
by intradermal injection of ovalbumin to ovalbumin-immunized rabbits, as an
Arthus phenomenon. A one or two % cream preparation of LCZ was topically applied
on the lesion daily after challenging injection until the inflamation had
diminished. By macroscopic observation and measuring the diameter of edema,
erythema, hemorrhage and necrosis, the effects of LCZ on the reactions were
compared with the reactions of the sites administered withcream vehicle as
reference agent. Two % LCZ showed an anti-hemorrhagic effect. The in vitro effect
of LCZ on production and functions of an inflammatory cytokine, TNF was also
examined. LCZ suppressed the production of TNF by murine peritoneal macrophages
at 20 micro g/ml and the adhesion of neutrophils at 100 micro g/ml. Moreover, LCZ
significantly suppressed the growth inhibitory activity of TNF against L929
fibroblasts at 0.5 micro g/ml. A very low concentration of LCZ might protect the
fibroblasts from immunological cytotoxicity in vivo. These findings suggest that
LCZ has a suppressive activity to inflammatory responses and this suppressive
action may be due to its protective activity to cells like fibroblasts.
PMID- 10777821
TI - [An autopsy case of HELLP syndrome with disseminated aspergillosis].
AB - Disseminated aspergillosis is an uncommon and unpredictable complication in
severely immunocompromised patients and poses a challenging problem in the
management and care of seriously ill patients receiving intensive care therapy.
We report an autopsied case of disseminated aspergillosis occurring ina 31-year
old female patient who was treated for HELLP (hemolysis, elevated liver enzymes,
and low platelet count) syndrome. She initially presented with edema and
proteinuria at a pregnancy check-up. At gestational age 33 weeks and 2 days, she
had right lower abdominal pain, nausea, and jaundice. The next day she delivered
a male neonate transvaginally, followed by excessive postpartum uterine bleeding.
Although an emergency hysterectomy was performed, her hemorrhagic diathesis could
not be controlled even after transcatheter embolization of the internal iliac
arteries with subsequent ligation and repeated blood transfusions totalling to
31,070 ml. She eventually died of a cerebral hemorrhage 21 days after the
parturition. Autopsy showed generalized jaundice and petechiae, as well as
extensive hemorrhage observed in the abdominal wall, peritoneal cavity, and
retroperitoneal and pelvic spaces. In addition,there were multifocal hemorrhages
found in the left temporal, right frontal and posterior lobes of the cerebrum,
and pons. Disseminated aspergillosis was found in the lungs, trachea, brain,
esophagus, stomach, heart, and thyroid gland. These findings suggest that
systemic postoperative complications, associated with massive blood transfusions
and hepatic failure, mutually contribute to the overall deterioration of host
defense mechanism, and may underlie the occurrence of devastating systemic fungal
infection.
PMID- 10777822
TI - Are giant cells conidia in Sporothrix schenckii? -Freeze-fracture electron
microscopic observation-.
AB - Sporothrix schenckii is a well-known pathogenic dimorphic fungus. In this study,
we focused on the plasma membrane ultrastructures of giant cells of S. schenckii
seen mainly on Sabouraud's dextroseagar slant medium. In the organisms grown for
1, 2, 3, 4, 6 and 8 weeks at 27 and 37 degrees C on brain heart infusion and
Sabouraud's dextrose agar slant media, the number of conidia, hyphae, brownish
and non-brownish giant cells were counted in ten separated areas under light
microscope (x100) to determine the culture conditions under which giant cells
were generated. The results showed that brownish giant cells were predominantly
seen after longer cultivation periods. Using freeze-fracture electron microscopy,
larger oval- or round shaped cells can be identified as conidia by their plasma
membrane ultrastructure characteristics, i.e, trench-like invaginations seen in
ordinary mature conidia (Maeda M et al.; Can J Microbiol 33: 40, 1987). From
these structural features seen by freeze-fracture electron microscopy, giant
cells appeared possibly be conidia and were suggested to be starved because of
their predominant existence under longer cultivation conditions.
PMID- 10777823
TI - [Protective effect of oral administration of several traditional Kampo-medicines
on lethal Candida infection in immunosuppressed mice].
AB - The protective effects of a "hozai" type of Kampo medicine, Juzen-taiho-to (Shi
quan-da-bu-tang, TJ-48), Hochu-ekki-to (Bu-zhong-yi-qi-tang, TJ-41) or Ninjin
yoei-to (Ren-shen-yang-rong-tang, TJ-108) on experimental candidiasis in
immunosuppressed mice were investigated. ICR mice, which were immunosuppressed by
injection of cyclophosphamide or prednisolone, were given these medicines orally
andchallenged intravenously with Candida albicans (day 0). Treatments with a
daily dose of 1 g/kg/day of TJ-48 or that of 1 or 2 g/kg/day of TJ-108 for 4
consecutive days from day-4 significantly prolonged the survival time of the
Candida-infected mice pretreated with cyclophosphamide. Treatments with a daily
dose of 1 g/kg/day of TJ-48 for 4 consecutive days from day 0, but not from day
4, significantly prolonged the life span of the Candida-infected mice pretreated
with prednisolone. On the basis of these results and previous findings,
characteristics of these kampo medicines as therapeutic agents against
candidiasis in immunosuppressed hosts were discussed.
PMID- 10777825
TI - What kind of controls to use in case control studies of malformed infants: recall
bias versus "teratogen nonspecificity" bias.
PMID- 10777824
TI - A case of seborrhoeic blepharitis.
AB - A fifty five-year old woman suffered from itching and scaling of the edge of her
eyelid. She had long used topical corticosteroid for this condition. Direct
examination of the scale by Parker KOH showed numerous fungal elements of spores
and hyphae of Malassezia furfur. She was treated with oral itraconazole (100 mg
daily or twice a week) for 8 weeks and was cured clinically and mycologically.
The result suggests the possibility of treatment with an anti-fungal drug for
seborrhoeic blepharitis or seborrhoeic dermatitis.
PMID- 10777826
TI - More on data from teratogen information systems (TIS)
PMID- 10777827
TI - Familial recurrence of nonsyndromic interrupted aortic arch and truncus
arteriosus with atrioventricular canal.
AB - BACKGROUND: Multifactorial inheritance is probably involved in most cases of
nonsyndromic conotruncal heart defects (CHDs), but Mendelian transmission is
often suspected. RESULTS: We report on a family with recurrence of nonsyndromic
CTHD in two double first cousins; i.e., two brothers married two sisters. One of
the cousins (case 1) had interrupted aortic arch (IAA) type B, while the other
one (case 2) had truncus arteriosus (TA) with atrioventricular canal defect
(AVCD). CONCLUSIONS: Our family further supports monogenic inheritance of CTHDs.
In addition, the presence of TA associated with AVCD in one of the patients
confirms the higher occurrence of CTHD in families with complex TA. The absence
of 22q11 microdeletion (del22q11) in our patients, as in several literature
reports of familial CTHDs, supports the existence of genes different to those
located on chromosome 22q11 which could be implicated in the pathogenesis of
CTHDs.
PMID- 10777828
TI - Effects of supplemental methionine on antiserum-induced dysmorphology in rat
embryos cultured in vitro.
AB - BACKGROUND: Heterologous antiserum to the visceral yolk sac (AVYS) is
teratogenic, inducing a spectrum of malformations in vivo and producing similar
effects in vitro. Numerous studies support the concept that AVYS-induced
malformations result from embryonic nutritional deficiency, without affecting the
maternal nutritional status. This has provided a useful model with which to
investigate the nutritional requirements of the early embryo, as well as the role
of various nutrients in the etiology of congenital defects. METHODS: In the
current investigation, we examined the effects of methionine and other nutrients
on AVYS-induced embryotoxicity in vitro. For these experiments, we cultured rat
embryos (9.5 p.c) for 48 hr with AVYS and/or methionine at several concentration
levels. RESULTS: The addition of L-methionine to AVYS-exposed cultures reduced
dysmorphology and open neural tube; this effect was concentration dependent. AVYS
induced dysmorphology was completely prevented at a concentration of L-methionine
corresponding to 50-fold the basal serum concentration. Utilization of D
methionine, L-leucine, or folic acid (5-methyltetrahydrofolate, MTHF) instead of
L-methionine had no protective effects. CONCLUSIONS: These results suggest that,
although AVYS limits the supply of all amino acids to the embryo, embryopathy
largely results from a deficiency of methionine. Furthermore, although
endocytosis and degradation of proteins by the VYS supplies most amino acids to
the embryo, free amino acids may be compensatory when this source is reduced.
These results support those of previous investigations that suggest methionine is
required for normal NT closure and that methionine is a limiting nutrient for
embryonic development.
PMID- 10777829
TI - Patterns of infant mortality caused by major congenital anomalies.
AB - BACKGROUND: We assessed the impact of recent advances in perinatal care on infant
mortality due to congenital anomaly. METHODS: Analysis of trends in congenital
anomaly-attributed infant mortality, using the 1981-1995 Statistics Canada's
birth and death records, with a total of 2,878,826 live births, 21,883 infant
deaths, and 6, 908 infant deaths due to congenital anomalies. RESULTS: Infant
mortality due to major congenital anomaly decreased from 3.11 per 1, 000 live
births in 1981 to 1.89 per 1,000 live births in 1995. Cause-specific infant
mortality rates for anencephaly, spina bifida, other central nervous system
anomalies, cardiovascular system anomalies, respiratory system anomalies,
digestive system anomalies, certain musculoskeleton anomalies, urinary system
anomalies, chromosomal anomalies, and multiple congenital anomalies were 0.20,
0.23, 0.27, 1.04, 0.24, 0.08, 0.22, 0.16, 0.22, and 0.13 per 1,000 live births,
respectively, in 1981-1983, whereas corresponding rates were 0.07, 0.07, 0.18,
0.73, 0.25, 0.03, 0.12, 0.12, 0.26, and 0.06 per 1,000 live births, respectively,
in 1993-1995. CONCLUSIONS: Recent Canadian data show that infant deaths caused by
major congenital anomalies have decreased significantly, but reductions varied
substantially according to specific forms of anomalies.
PMID- 10777830
TI - Expression of the sonic hedgehog gene in human embryos with neural tube defects.
AB - BACKGROUND: To estimate the rate of malformations observed during early human
development, a series of 38,913 first-trimester abortions were studied. Neural
tube defects (NTD) were found in 57 cases. METHODS: A histological study of
serial sections performed in 25 embryos revealed a spectrum of axial structure
abnormalities. Expression of the SHH gene was studied by in situ hybridization in
one case of CRS and in two cases of SB. RESULTS: A cervical notochord duplication
was always found in craniorachischisis (CRS, n = 8), but not in spina bifida (SB,
n = 10) or diplomyelia (split cord malformation, n = 3). In the embryo with CRS,
expression of SHH was found in both domains, corresponding to the duplicated part
of the notochord, whereas a single signal was observed in the nonduplicated part.
This expression was associated at the cervical level of the open neural tube with
a broad SHH expression domain and with two or even three domains in its lumbar
region, suggesting multiple functional floor plates. Similarly, in two embryos
with SB, two domains of SHH expression were found in the ventral neural tube.
CONCLUSIONS: Our findings suggest that notochord splitting in the cervical region
might be involved in the pathogenesis of CRS. Interestingly, similar notochord
abnormality and altered expression of the shh gene are observed in Lp mice with
NTD. This suggests that the Lp gene could be a candidate gene for human CRS.
Further studies are needed to establish the primary event responsible for the
notochord splitting and for the abnormal expression of the SHH gene in the floor
plate in embryos with CRS and SB.
PMID- 10777831
TI - Malformations in offspring of diabetic rats: morphometric analysis of neural
crest-derived organs and effects of maternal vitamin E treatment.
AB - BACKGROUND: We have previously reported on a malformation-prone Sprague-Dawley
rat substrain (U), which presents a high frequency of micrognathia in the
offspring of diabetic mothers. This malformation is related to impaired
development of the cranial neural crest cells (NCC); the defect may be prevented
by antioxidative treatment of the mother. METHODS: We have therefore investigated
whether fetuses of diabetic rats display other malformations associated with
altered cranial NCC development and whether maternal vitamin E supplementation
may affect such malformations. RESULTS: Fetuses of diabetic rats showed low-set
external ears, severely malformed Meckel's cartilage, small thyroid and thymus,
and absence of parathyroid glands. Cardiac anomalies were frequently observed,
including rightward displacement of the aorta, double outlet right ventricle
(DORV), persistent truncus arteriosus (PTA) combined with ventricular septal
defects due to a malaligned outlet septum. The malformations in the outflow tract
included abnormalities of the great arteries; right-sided aortic arch/descending
aorta, and double aortic arches. These defects tended to occur together within
individual fetuses. Maternal dietary treatment with 2% vitamin E markedly reduced
the severity of the malformations. CONCLUSIONS: The phenotypic appearance of
these defects is strikingly similar to the DiGeorge anomaly in humans, which has
been found in children of diabetic mothers together with an overrepresentation of
PTA and DORV. The malformations associated with defective NCC development in the
offspring of diabetic U rats show several morphological similarities to those in
humans; hence the teratogenic mechanisms may be similar and accessible for study.
PMID- 10777832
TI - Interrupted aortic arch: an epidemiologic study.
AB - BACKGROUND: Interruption of the aortic arch (IAA) is a rare but severe anomaly
associated with major intracardiac defects and with multisystem noncardiac
malformations, recently linked to chromosome deletion of 22q11.2. METHODS: The
Baltimore-Washington Infant Study (1981-1989), a population-based epidemiologic
study of cardiovascular malformations, evaluated 53 infants with IAA in
comparison with 3,572 controls. Risk factors for the anatomic subtypes were
evaluated in 14 cases of IAA type A and 32 cases of IAA type B, but no molecular
genetic tests were available. The distribution of associated cardiac defects was
similar for both types. RESULTS: DiGeorge syndrome (DGS) occurred more frequently
in IAA type B. Case-control comparisons demonstrated that infants in both groups
were growth retarded at birth. A family history of noncardiac defects occurred
only in IAA type B cases and included relatives with cleft lip and/or cleft
palate. Candidate risk factors were associated only in type B cases and differed
for those with (n = 10) and for those without (n = 19) DGS: a family history of
noncardiac defects (odds ratio [OR] = 7.2, 95% confidence interval [CI] = 1.5
39.2) and maternal use of aspirin during the critical period (OR = 4.8, 95% CI =
1.3-25.4) occurred with DGS, while previous stillbirth (OR = 9.4, 95% CI = 1.3
53.1), bleeding during pregnancy (OR = 3.7, 95% CI = 1.4-11.4), and maternal
exposure to arts/crafts paints (OR = 4.8, 95% CI = 1.3-17.4) were associated in
those without DGS. CONCLUSIONS: These findings confirm the heterogeneity of IAA
and of the type B subtype. Risk factors specific for cases with DGS may open a
window to further investigations of the etiology of IAA and of the associated
molecular genetic abnormalities.
PMID- 10777833
TI - Spina bifida phenotypes in infants or fetuses of obese mothers.
AB - BACKGROUND: A twofold or greater risk of neural tube defect (NTD)-affected
pregnancy has been associated with prepregnant obesity, where obesity was defined
as body mass index (BMI) of >29 kg/m(2). Risks have been more elevated for spina
bifida than for anencephaly. METHODS: We investigated whether finer phenotypic
classifications of spina bifida, in combination with other factors, were
associated with a BMI of >29 kg/m(2). Data were derived from a case-control study
of fetuses and infants with NTDs among 1989-1991 California births. Interviews
were conducted with mothers of 277 spina bifida cases and 517 nonmalformed
controls. RESULTS: Women with a BMI of >29 kg/m(2) compared with those =29
kg/m(2) revealed an odds ratio (OR) of 2.2 (95% confidence interval [95% CI] =
1.4-3. 3) for spina bifida in their infants and fetuses. Elevated risks were
observed for each spina bifida subphenotype, and risks varied by subphenotype:
open spina bifida, OR = 2.0 (1.2-3.1); closed (skin-covered), 3.3 (1.4-7.5);
isolated, 2.2 (1.4-3.4); nonisolated, 1.9 (0.9-4.2); high, 4.5 (2.1-9.6); low,
1.9 (1.2-2.9); open/isolated/high, 7.1 (2.8-18.1); and open/isolated/low, 1.8 (1.
1-3.1). Risks were higher among female infants/fetuses and foreign-born Latinas,
and for some phenotypes the risks were quite large, e.g., OR = 8.3 (2.9-23.6) for
"closed" spina bifida among female infants/fetuses whose mothers were >29 kg/m(2)
compared with males whose mothers were =29 kg/m(2). Maternal periconceptional
vitamin use was not observed to influence risk as greatly across phenotypes.
CONCLUSIONS: The observed pathogenetic heterogeneity of prepregnant obesity and
spina bifida risks suggests that there are likely to be several biologic
mechanisms underlying the association.
PMID- 10777834
TI - Prenatal ages and stages-measures and errors.
AB - BACKGROUND: The confusing term "gestational age" is generally either not defined
or is used for menstrual "age," postovulatory age, or postfertilizational age.
The designation (post)menstrual weeks and/or days is very useful in obstetrics
but, because prenatal age extends from fertilization to birth, menstrual "age" is
a misnomer. The term "stage" has a specific morphological meaning in embryology
and should not be used either for ages or for lengths. METHODS: Embryonic age is
best assessed, when possible, from the 23 internationally recognized
morphological stages. A morphological staging system is not available for the
fetal period, and fetal age is assessed mainly from measurements. RESULTS: Among
these, the unsatisfactory designation crown-rump length (CRL) should be replaced,
in ultrasonic biometry as well as in embryology, by the greatest length (GL),
exclusive of the lower limbs. These points are discussed in detail, and
justification for the views expressed is provided. CONCLUSIONS: The continuing
confusion concerning prenatal age is shown to be unnecessary once the ambiguous
and superfluous term "gestational age" is abandoned.
PMID- 10777835
TI - Introduction.
PMID- 10777836
TI - Impact of natural chemokine receptor polymorphisms on perinatal transmission of
human immunodeficiency virus type 1.
PMID- 10777837
TI - Role of the placenta in fetal HIV infection.
PMID- 10777838
TI - Follow-up of children exposed to perinatal antiretrovirals.
PMID- 10777840
TI - It's what the surgeon doesn't see that kills the patient.
AB - Peritoneal dissemination can be prevented by the responsible surgeon at least in
part by proper surgical technique used to resect the primary malignancy. What
most people do not know is that cancer surgery can do great harm. It can convert
a contained malignant condition into a disseminated disease that unnecessarily
becomes a deadly process. Containment must be the number one priority of the
gastrointestinal cancer surgery. Also, established peritoneal carcinomatosis can
be cured if it is attacked in a timely fashion with peritonectomy procedures and
heated intraoperative intraperitoneal chemotherapy. Many small changes can make a
big difference in survival with gastrointestinal cancer surgery.
PMID- 10777839
TI - Potential toxicities of HIV therapeutics in the developing infant.
PMID- 10777841
TI - Endoscopic treatment of vesicoureteral reflux in children with glutaraldehyde
cross-linked bovine dermal collagen. Short-term results.
AB - BACKGROUND: Endoscopic treatment using glutaraldehyde cross-linked (GAX) collagen
was conducted on 4 children with bilateral primary vesicoureteral reflux
(VUR)..... a 1-year-old boy and three 5- to 8-year-old girls $B!D (Ball having a
history of repeated hospitalization for fever due to acute pyelonephritis,
visiting as pediatric outpatients regularly and receiving antibiotics
continuously. By international VUR classification, 4 ureters were grade 3, 2
grade 4, and 2 grade 5. METHODS: After nonallergy to GAX collagen was confirmed
intracutaneously, a needle was used through a 9.5 Fr cystoscope channel to
puncture bladder mucosa 4 to 5 mm from the affected ureteral orifice at 6 o'clock
under general anesthesia; 1.1 to 1.9 ml of GAX collagen was injected immediately
below affected orifices. RESULTS: Three months after surgery, voiding
cystourethrography showed reflux had disappeared in 6 ureters, for a short-term
success rate of 75%. VUR in the Remaining 2 ureters improved from grade 3 to 1
and from grade 5 to 4. No postoperative urinary tract infection occurred and
antibiotics were stopped. CONCLUSION: Since GAX collagen is less viscous than
Teflon paste, it is easily injected into submucosa, does not form granuloma or
migrate to other organs, and is noncarcinogenic. Endoscopic VUR treatment using
GAX collagen is indicated when less invasion and shorter hospitalization are
considered, although it requires general anesthesia, which itself involves some
risk.
PMID- 10777842
TI - The clinical efficacy of neuroendoscope in surgical treatment for deafferentation
pain.
AB - Spinal cord stimulation (SCS) is one of the most minimally invasive and effective
treatments for intractable pain. We report the efficacy of a very small diameter
neuroendoscope on setting the electrode to the proper site in the epidural space.
Our cases include thalamic hemorrhage, and each patient had unilateral
intractable pain on L1 or less as the main complaint. They had been treated for
over two years in other hospitals, but no significant relief was achieved.
Because each patient had been given frequent epidural blocks, the adhesion in the
epidural space was expected. In Group A (3 cases), we used very small diameter
neuroendoscope to dissect adhesion in the epidural space and to make optimal
space for lead placement under direct vision. Conventional lead placement under
fluoroscopy was performed in Group B (3 cases). Medtronic's PISCES lead system
was used for SCS. In Group A, stimulation and pain regions matched in all cases,
and good pain relief was also achieved. In Group B, however, stimulation and pain
regions matched incompletely and the increase in stimulation caused stimulation
on the pain-free side.
PMID- 10777843
TI - Femoral bone density and changes therein associated with differing histories of
pregnancy and lactation in aged rats.
AB - OBJECTIVE: To examine the effect of prior pregnancy and lactation on bone density
in aged rats. MATERIALS AND METHODS: 2 month-old female Fischer-344 rats were
divided into 4 groups: 1)13 rats were allowed to get pregnant and to nurse their
offspring for two or three cycles; 2)14 rats were allowed to get pregnant two or
three times and were immediately separated from their young after each delivery
prior to lactation; 3)10 rats were not allowed to become pregnant; and 4)7 rats
were sacrificed at the beginning of the experiment. All rats were fed ad libitum.
After the rats had completed two or three pregnancies with or without subsequent
lactation, all were fed a restricted diet until they were 25 months old (aged
rats). Then they were sacrificed and both femurs were removed from each rat. One
bone was used for analysis of mineral content and the other bone was used for
photodensitometry of the diaphysis. RESULTS: 31 rats (83.8% ) survived until they
were sacrificed. The femurs of the aged rats showed increased ash weight compared
to those of 2 month-old rats. Aged rats with prior pregnancies with or without
subsequent lactation had higher femoral ash weight than those without prior
pregnancies. There were no differences among aged rats in regard to marrow
diameter, bone diameter, cortical width or bone density of the diaphysis in femur
by photodensitometry. CONCLUSION: In aged rats, past pregnancies but not
lactation were related to increases in bone density of the femur.
PMID- 10777844
TI - 4D-CT: a new development in three-dimensional hepatic computed tomography.
AB - OBJECTIVE: Addition of contrast dynamics to three-dimensional hepatic tumor CT
imaging. MATERIALS AND METHODS: Six patients with hepatic cavernous hemangioma
with a mean age of 57 years were included in the study. Two of the patients were
male and four were female. Contrast enhanced computed tomography (CT) was carried
out on the tumors in six phases by helical CT, using bolus injection of contrast
medium intravenously. Using maximum intensity projection (MIP), a separate three
dimensional image was then reconstructed for each phase, and rotational images
around the longitudinal axis of the torso were observed using the CRT monitor.
RESULTS: The patterns of contrast enhancement of hepatic cavernous hemangiomas
were obtained on 3D-images. In all patients, the reciprocal relations between the
tumor and the portal veins and the hepatic veins were clearly imaged three
dimensionally. CONCLUSIONS: We have succeeded in adding the dynamic observation
of a contrast medium to static three-dimensional imaging. This will be valuable
for the diagnosis of hepatic tumors, and it opens up new prospects for diagnostic
imaging.
PMID- 10777845
TI - Evaluation of prognostic factors and PCNA expression for pulmonary metastatic
tumors of colorectal carcinoma.
AB - The present study was conducted to evaluate clinicopathologically 26 patients
whose primary colorectal carcinoma and resulting pulmonary metastatic tumors had
been resected, and to determine the relationship between tumor progress and
prognosis by PCNA immunostaining. Patients with solitary pulmonary metastasis
were found to have much better prognoses than those with multiple metastasis.
There was no correlation between tumor size of pulmonary metastasis and
prognosis. Survival rates of patients with disease-free intervals (DFIs) of 2
years or longer were higher than for those with DFIs of less than 2 years. Mean
PCNA expression of pulmonary metastatic lesions was significantly higher than
that of primary lesions. It was suggested that the higher PCNA expression
stemming from the relation between depth of tumor invasion and PCNA expression
was greater with tumor progress.
PMID- 10777846
TI - Surgical treatment of comminuted fractures of the distal clavicle using Wolter
clavicular plates.
AB - Surgical reduction and fixation using Wolter clavicular plates was performed in
16 patients with distal clavicle fractures. Good bony union was obtained in all
cases. The patients had neither postoperative pain nor muscle weakness. Compared
with tension band wiring, the Wolter clavicular plates were better able to
maintain the anatomic repositioning of comminuted distal clavicle fractures.
However this method takes longer and requires a second operation for plate
removal. Wolter clavicular plate placement is the treatment of choice for
unstable distal clavicle fractures with small comminuted fragments.
PMID- 10777847
TI - [Practical diagnosis and treatment of Graves' disease].
PMID- 10777848
TI - [Detection of messenger RNA expression cells in tissue specimens: technical note
for in situ hybridization using digoxigenin labeled probe].
PMID- 10777849
TI - Current understanding of the cause of dental caries.
AB - Dental caries-associated oral streptococci are called the mutans streptococci,
with Streptococcus mutans and Streptococcus sobrinus being the most prevalent
caries-associated organisms in humans. Strains of the mutans streptococci are
highly conserved within not only mothers and their children but also racial
groups, suggesting vertical transmission of this organism within human
populations. It has been found that the mother-child infection route of the
mutans streptococci can be prevented by simply reducing the amount of the mutans
streptococci contained in the mothers' saliva. Moreover, a chlorhexidine varnish
reduces the salivary mutans streptococci by an average of 3 logs (99.9%), and
moved them below detectable levels. We should attempt to eliminate the infection
with the mutans streptococci among Japanese people by attempting to break the
infectious chain from mothers to children.
PMID- 10777850
TI - Does polio eradication succeed meeting the target year of 2000?
AB - The global polio eradication program is under way with the target year of 2000.
We reviewed the program progress, in perspective, from the experience of the
global smallpox eradication, which is at present a sole disease ever eradicated
by orchestrated global efforts. We concluded that despite substantial efforts
being made by the World Health Organization and member states with the current
progress, it would require additional some three years, namely 2002. This would
safe-guard the success. As of January 2000, there are still at least 22 endemic
states in Indian Subcontinent and sub-Saharan Africa. Experiences in smallpox
eradication, although the disease is different, indicated that to stop
transmission in such a large number of endemic states took more than three years,
assuming that further support would come toward the final goal.
PMID- 10777851
TI - Insecticide susceptibility status of Culex tritaeniorhynchus giles, vector of
Japanese encephalitis in Delhi.
AB - Laboratory studies were carried out to ascertain the current susceptibility
status of adult and larval stages of the Culex tritaeniorhynchus mosquito, vector
of Japanese encephalitis, to various insecticides used under public health
programs in India. The present study revealed that exposure of adult mosquitoes
to diagnostic concentrations of DDT - 4.0%, malathion - 5.0%, fenitrothion -
1.0%, and propoxur - 0.1% could induce only 50.0, 10. 0, 15.0, and 5.0%
mortality, respectively, indicating that the species was resistant to all of
these insecticides. The LT50 and LT95 values calculated using diagnostic
concentrations of DDT, malathion, fenitrothion, and propoxur were found to be
56.4 and 136, 138 and 272, 185 and 258, and 187 and 249 min, respectively.
However, when adult mosquitoes were exposed to the diagnostic concentration of
synthetic pyrethroids, viz., deltamethrin - 0.025%, permethrin - 0.25%, and
lambdacyhalothrin - 0.1%, 100.0% mortality was observed, indicating that the
species was highly susceptible to these adulticides. Larval susceptibility tests
carried out using diagnostic dosages of DDT- 0.008, temephos- 0.02, fenthion-
0.008, fenitrothion- 0.125, and malathion- 0.005 mg/l failed to induce any
mortality, indicating that larvae were resistant to these larvicides. The LC50
and LC90 values calculated for commonly used larvicides, viz., temephos and
fenthion, were 0.1511 and 1.9098, and 0.6151 and 2.395 mg/l, respectively.
Increase in tolerance level were estimated at 95.5- and 299.4-fold when these
LC90 values were compared with diagnostic dosages of temephos and fenthion,
respectively.
PMID- 10777852
TI - Salmonella typhimurium DT104 from livestock in Japan.
AB - We examined the distribution of multidrug-resistant Salmonella enterica serotype
Typhimurium definitive phage type 104 (DT104) among Japanese livestock from 1973
to 1998. The 144 S. Typhimurium field isolates were tested for susceptibility to
ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, tetracycline,
kanamycin, trimethoprim, nalidixic acid, and norfloxacin. Thirty-six of 68
strains which exhibited resistance to five or more antimicrobials (ACSSuT+) were
identified as DT104. Results of plasmid profiling showed that all DT104 strains
retain a 90-kb virulence plasmid, while 20 of 36 strains possessed a few
additional small plasmids ranging from 2 to 4 kb. These results showed that DT104
strains have existed in Japanese livestock since 1990, and that this phage type
may be an important pathogen for cattle in Japan.
PMID- 10777853
TI - Molluscicidal saponins from Anagallis arvensis against schistosome intermediate
hosts.
AB - The molluscicidal activity of saponins isolated from the plant Anagallis arvensis
(Primulaceae) was studied against schistosome intermediate hosts, Biomphalaria
glabrata and Oncomelania quadrasi. @Strong molluscicidal activity was found in
two compounds called desglucoanagalloside B and anagalloside B. Their structures
were identified on the basis of chemical and spectroscopic analyses and their
activities are comparable to that of the synthetic molluscicide, niclosamide.
PMID- 10777854
TI - Inverse relation between number of methicillin-resistant staphylococcus aureus
(MRSA) isolates and total number of bacterial specimens submitted to laboratory
diagnosis.
PMID- 10777855
TI - Seroprevalence of parvovirus B19 among HIV-1-positives in Japan.
PMID- 10777856
TI - Adenovirus type 7 outbreaks in Japan in 1998.
PMID- 10777857
TI - Outbreak of salmonella enteritidis caused by contaminated buns peddled by a
producer using traveling cars in hyogo and neighboring prefectures in 1999: an
epidemiological study using pulsed-field gel electrophoresis.
PMID- 10777858
TI - Comparison by pulsed-field gel electrophoresis of salmonella enteritidis
genotypes from various food poisoning outbreaks from 1997 to 1999 in hyogo
prefecture.
PMID- 10777859
TI - Japanese spotted fever cases in Kochi prefecture.
PMID- 10777861
TI - Mercury(II) polyphosphate, Hg(PO3)2
PMID- 10777860
TI - Anti-fungal chemotherapy for symptomatic pulmonary aspergilloma.
PMID- 10777862
TI - Rubidium stannate(IV), Rb4SnO4
PMID- 10777863
TI - High-temperature LaAs2
PMID- 10777864
TI - (Triphenylarsine)iodinemonobromine: a charge-transfer adduct in which arsenic
selectively bonds to iodine
PMID- 10777865
TI - Two saccharinate complexes:
PMID- 10777866
TI - A three-dimensional network of cadmium
PMID- 10777867
TI - Redetermination of the double salt lambda-
PMID- 10777870
TI - Diaquatris(pentane-2,4-dionato-O,O')holmium(III) monohydrate and
diaquatris(pentane-2,4-dionato-O,O')holmium(III) 4-hydroxypentan-2-one solvate
dihydrate
PMID- 10777869
TI - Bis(tetra-n-butylammonium) bis[(mandelato)oxo(peroxo)vanadate(V)] mandelic acid
solvate.
PMID- 10777871
TI - Tetrabutylbis(N-phthaloylglycinato)distannoxane dimer.
PMID- 10777872
TI - Hexakis(imidazole-N3)nickel(II) bis(4-methoxybenzoate).
PMID- 10777873
TI - Hexaaquabis(dimethyl sulfoxide)yttrium(III) trichloride
PMID- 10777874
TI - Bis(4-aminopyridine)silver(I) nitrate and tris(2,6-diaminopyridine)silver(I)
nitrate
PMID- 10777875
TI - Sodium diphenylacetate, an infinite columnar structure
PMID- 10777876
TI - Linkage isomerism of organoplatinum(II) compounds coordinated by two 1,3
dimethylbarbiturate anions
PMID- 10777877
TI - Bis(4-hydroxybenzoato-O)(1,4,8,11-tetraazacyclotetradecane-kappa 4N)nickel(II): a
three-dimensional framework built from O-H...O and N-H...O hydrogen bonds
PMID- 10777878
TI - Na10(glycine)2[H2W12O42].28H2O.
PMID- 10777880
TI - (Dicyclohexyldithiophosphinato-S,S')-
PMID- 10777879
TI - Bis
PMID- 10777881
TI - Sulfido-bridged rhenium-carbonyl complexes with planar and folded Re2S2 cores
PMID- 10777882
TI - (2-Acetylpyridine-kappa N 4-phenylthiosemicarbazonato-kappa 2N1,S)halogeno-trans
dimethyltin(IV) (halogeno = chloro and bromo).
PMID- 10777883
TI - N,N'-dimethyl-1,4-dithiine-1,2:4,5-tetracarboximide and N,N'-dimethyl-1,4
diselenine-1,2:4,5-tetracarboximide
PMID- 10777884
TI - Structural analysis of pyrrolidinones.
PMID- 10777885
TI - Tylophorine B benzene solvate.
PMID- 10777887
TI - 1-deoxy-1-(4-fluorophenyl)-beta-D-ribofuranose, its hemihydrate, and 1-deoxy-1
(2,4-difluorophenyl)-beta-D-ribofuranose: structural evidence for intermolecular
C-H...F-C interactions
PMID- 10777886
TI - 2beta-Hydroxy-4'-demethyldesoxy-podophyllotoxin.
PMID- 10777888
TI - 1:1 complex of 4-nitrobenzoic acid and 4-nitropyridine N-oxide
PMID- 10777889
TI - Two phenanthroline hydrochlorides
PMID- 10777890
TI - 4,4'-dibromobenzophenone at 293 and 103 K
PMID- 10777892
TI - Weak C-H...O and C-H...N interactions in nitropyrazoles
PMID- 10777891
TI - 2,6-bis-(3-trifluoromethylpyrazol-1-yl)-pyridine
PMID- 10777893
TI - The gamma-form of n-eicosanol
PMID- 10777894
TI - 3-(2-furyl)-6-(4-methylphenyl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine and its
6-phenyl analogue.
PMID- 10777895
TI - Leurosine methiodide-methanol-water (1/3/2).
PMID- 10777896
TI - (1R,2S)-2-[N-methyl-N-(4-toluene-sulfonyl)amino]-1-phenylpropan-1-ol.
PMID- 10777897
TI - 4,17,25,26-tetraaza-6,9,12,15-tetraoxa-2,19,21,24-tetrathiatricyclo-
PMID- 10777898
TI - N-(4-cyanophenyl)-alpha-(4-methoxyphenyl)nitrone
PMID- 10777899
TI - Cyclomicrobuxine monohydrate.
PMID- 10777900
TI - 2,2-dimethyl-1-(2,4,6-trinitrophenyl)hydrazine
PMID- 10777901
TI - Acetone-4-methylthiosemicarbazone at 220 K.
PMID- 10777902
TI - Chiral and meso-bis(
PMID- 10777903
TI - 4-(4-hydroxybenzylideneamino)-4H-1,2,4-triazole hemihydrate.
PMID- 10777904
TI - 4-chloro-N-(4-cyano-2-nitrophenyl)-3-nitrobenzamide
PMID- 10777905
TI - Model porphyrin precursors: 1,2,4,5-tetrakis(cyanomethyl)benzene, methyl 3,4,5
triacetoxybenzoate and 2-(N-phthalimidomethyl)benzoic acid.
PMID- 10777908
TI - (E)-5-
PMID- 10777906
TI - Absolute configuration of (-)-4-(3,4-dichlorophenyl)-4-(2-pyridyl)butanoic acid:
essential information to determine crucial steric features of arpromidine-type
histamine H2 receptor agonists.
PMID- 10777907
TI - Morpholine-beta-iodophenylacetylene (1/1) revisited: an exceptionally short I...N
contact
PMID- 10777909
TI - 1-(2,4,6-trimethylphenyl)-1H-1,2,3,4-tetrazole
PMID- 10777911
TI - A series of three bis
PMID- 10777910
TI - 8-chloro-6-phenyl-4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepin-5(6H)-one.
PMID- 10777912
TI - C
PMID- 10777913
TI - Cadmium copper tetrachloride tetrahydrate
PMID- 10777914
TI - Redetermination of the iron-zinc phase FeZn13
PMID- 10777915
TI - Sn4.4Mo24O38
PMID- 10777916
TI - A new cluster complex, (NH4)6
PMID- 10777917
TI - Barium vanadium(III) hydrogen phosphate, Ba3V2(HPO4)6
PMID- 10777918
TI - The monoclinic and cubic phases of metaboric acid (precise redeterminations)
PMID- 10777919
TI - Halocarbon and arene coordination of lithium(I) in (1-anilino-3
phenyliminopropenyl)chloro(methyl)aluminium bis
PMID- 10777920
TI - (2,2'-dipyridyl sulfide-N,N')hydroxy-bis(nitrito-Q)(nitrogen monoxide
N)ruthenium(III)
PMID- 10777921
TI - Protonation products of pentaaminopentane as novel building blocks for hydrogen
bonded networks.
PMID- 10777922
TI - Chains of (4,4'-bipyridyl)copper(I) bridged by dimolybdate units
PMID- 10777923
TI - Bis
PMID- 10777924
TI - (2,2'-bipyridine-kappa 2N)bis
PMID- 10777925
TI - Poly
PMID- 10777926
TI - Dichlorodiethylbis(pyridine-N)tin(IV).
PMID- 10777927
TI - trans-diaqua(C-meso-5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane-
N,N',N",N"')copper(II) dichloride dihydrate
PMID- 10777928
TI - The one-electron oxidation product of a metallocenyl-terminated cyanine
PMID- 10777930
TI - [2,6-bis]
PMID- 10777929
TI - Copper(II) and zinc(II) complexes of pyridine-2,6-dicarboxylic acid.
PMID- 10777931
TI - One-dimensional chains in sodium tetraphenylphosphonium bis(2-mercapto-4-
methylphenolato-O,S)oxo-vanadate(IV)
PMID- 10777932
TI - Triaquatris(mu-oxydiacetato)dipraseodymium(III) pentahydrate and hexaaquatris(mu
oxydiacetato)dineodymium(III) oxydiacetic acid solvate dihydrate
PMID- 10777933
TI - Aquatris(1,10-phenanthroline)(trans-2,3-dimethylacrylato)ytterbium(III)
PMID- 10777934
TI - Bis
PMID- 10777935
TI - Polymeric tetraaquatris(malonato)-dilanthanum(III) monohydrate
PMID- 10777936
TI - Complexes of dimethyltin dihalides with N-methylpyrrolidinone, C12H24N2O2X2Sn (X
= Cl, Br or I)
PMID- 10777937
TI - (N-maleoylglycinato)trimethyltin(IV).
PMID- 10777938
TI - Trans-(2-methylthiobenzoato-O)-phenylbis(triphenylphosphine)-palladium(II), two
conformational isomers
PMID- 10777939
TI - [2-]
PMID- 10777940
TI - 6-aminonicotinic acid hydrochloride
PMID- 10777941
TI - 2-amino derivatives of 5-nitrophenylacetamide
PMID- 10777942
TI - N-piperonyl analogue of the atypical antipsychotic clozapine.
PMID- 10777944
TI - 5,11,17,23-tetra-tert-butyl-25,27-bis(carboxymethoxy)-26,28-bis(2-
methoxyethoxy)calix
PMID- 10777943
TI - 2-hydroxy-1-naphthaldehyde 2-methylthiosemicarbazone.
PMID- 10777945
TI - 5-amino-6-phenyl-1,6-dihydropyridazin-3(2H)-one.
PMID- 10777946
TI - N,N'-bis(2-tosylaminobenzylidene)-1,2-ethanediamine
PMID- 10777947
TI - N-benzyl-2'-iodocinnamanilide and N-benzyl-2'-iodo-4'-methyl-2
phenylcinnamanilide.
PMID- 10777948
TI - (+/-)-9-(2-bromophenyl)-7,7-dimethyl-1,3,4,5,6,7,8,9-octahydrofuro
PMID- 10777949
TI - 2-bromo-5-hydroxybenzaldehyde
PMID- 10777950
TI - (m-CH3C6H4NH3)6P6O18
PMID- 10777952
TI - 6-(1-hydroxy-2,2-diphenylethyl)-4,4-diphenyl-2-cyclohexen-1-one
PMID- 10777951
TI - (1S,4R,5R,6R)-6-methoxycarbonyl-4-pivaloyloxy-2-(pivaloyloxymethyl)-
bicyclo[3.1.0]hex-2-ene-1-carboxylic acid.
PMID- 10777953
TI - 3,5-diamino-6-(2-fluorophenyl)-1,2,4-triazine-dimethylformamide (1/1).
PMID- 10777954
TI - Intermolecular interactions in the chiral and racemic forms of 3-hydroxy-2-(1
oxoisoindolin-2-yl)butanoic acid derived from threonine.
PMID- 10777956
TI - 7-oxobicyclo
PMID- 10777955
TI - Costuslactone B.
PMID- 10777957
TI - Azinyl sulfides. L. 14-methyl-1,4-thiazino[2,3-c;6,5-c']diquinoline.
PMID- 10777958
TI - Two tetrahydrofuran solvates of HN(SePPh2)2
PMID- 10777960
TI - 2,6-bis
PMID- 10777959
TI - 25,27:26,28-bis(3,9-dioxa-6-azaundecane-1,11-dioxy)calix
PMID- 10777961
TI - A new precursor for the synthesis of porphyrazine: 2,3-bis(4
methylphenyl)maleonitrile
PMID- 10777962
TI - A novel class of fused heterocycles, benzo
PMID- 10777963
TI - An angularly fused three-ring precursor to phytuberin.
PMID- 10777965
TI - 4-chloroacetophenone
PMID- 10777964
TI - N-ethylazatribenzo-21-crown-7
PMID- 10777966
TI - [Molecular interactions in the metabolism of copper and iron].
PMID- 10777967
TI - [Heterogeneous expression of cyclin D3 in breast carcinoma:absence of prognostic
significance in a series of 92 cases with long follow-up].
PMID- 10777968
TI - [A further object of controversy: Giulio Bizzozero and the discovery of
platelets].
PMID- 10777969
TI - The embodiment of class-related and health inequalities: Australian policies.
PMID- 10777970
TI - The citation index: what it is and what it isn't.
PMID- 10777971
TI - Long-term benzodiazepine use by elderly people living in the community.
AB - OBJECTIVE: To investigate the prevalence of long-term benzodiazepine use in an
elderly community sample, and factors associated with such use. METHOD: Data came
from the Sydney Older Persons Study, a longitudinal study of people aged 75 or
over. There were 337 subjects who were interviewed in 1991-93, and subsequently
followed up after three and 4.5 years. At the first interview, subjects were
assessed for socio-demographic characteristics, physical and mental health, and
use of health services. At the first and subsequent interviews, subjects were
asked about use of medications, including benzodiazepines. RESULTS: There were
16.6% who were using benzodiazepines at the time of all three interviews, while a
further 19.6% were using them at one or two interviews. In a multivariate ordered
logit regression model, long-term benzodiazepine use was associated with
treatment for nervous conditions, restless sleep, being female, being divorced
and greater contact with medical services. CONCLUSIONS: The prevalence of
benzodiazepine use in the elderly is high and much of this use is long term. The
high prevalence of benzodiazepine use stands in contrast to the findings from
national surveys that the elderly living in the community tend to have better
mental health than younger age groups. IMPLICATIONS: Efforts are needed to reduce
the number of elderly people becoming long-term users. The use of benzodiazepines
in this age group is of particular concern, because they may be a risk factor for
falls and for cognitive impairment in the elderly.
PMID- 10777972
TI - Age at first intercourse in an Australian national sample of technical college
students.
AB - OBJECTIVE: This study aims to broaden the current body of knowledge regarding the
sexual behaviour of young Australians by examining the age and correlates of age
of first intercourse in a national sample of Technical and Further Education
apprentices. METHOD: In 1995, students at randomly selected technical colleges in
Australia were surveyed on HIV-related issues. Questionnaires were administered
to a stratified cluster sample of automotive, hairdressing and commercial cookery
apprentices. Respondents were asked the age at which they first had heterosexual
vaginal or anal intercourse. RESULTS: Of 4,055 respondents aged 15-24 years,
3,848 answered the question; 3,195 (83%) had had intercourse. Males and females
did not differ significantly. Median age at first intercourse was 16 (range 12
23). In multivariate analysis, older age at first intercourse was associated
with: greater age at interview; higher school education; church attendance; and
State of residence. The model, however, accounted for only 14% of the variance in
age at first intercourse. CONCLUSIONS AND IMPLICATIONS: In this sample, those
apprentices who completed secondary school became sexually active later on
average than those who left before the end of Year 10. For sex education to occur
before sexual initiation, it needs to be offered in primary schools and the first
year of high school (aged 11-13 years). Further, as technical college students
are likely to initiate sex earlier than their age mates still at school, colleges
may be in a position to take responsibility for the continuing sexual education
of this group, especially for those students entering college at 15 or 16 years
of age.
PMID- 10777973
TI - Immunisation coverage reporting through the Australian Childhood Immunisation
Register--an evaluation of the third-dose assumption.
AB - OBJECTIVE: The Australian Childhood Immunisation Register (ACIR) currently
classifies those children who have the third dose recorded as fully immunised at
12 months of age, even if records of earlier doses are missing. This analysis
assesses the impact this "third-dose assumption" has on immunisation coverage
estimates for children aged 12 months. METHODS: ACIR records from three equally
spaced cohorts of children at 12 months of age, which relied on the third-dose
assumption, were examined for variation in doses and vaccine types recorded by
jurisdiction and Medicare registration status. RESULTS: Although the percentage
reduction in coverage without application of the third-dose assumption decreased
through the three cohorts examined, the proportion classified as fully immunised
still decreased by 11-12% (to < 75%) if the third-dose assumption was not used in
the most recent cohort. "Fully immunised" status among children with delayed
Medicare registration or in jurisdictions with a high proportion of paper
reporting to the ACIR was disproportionately reduced without use of the
assumption. CONCLUSIONS AND IMPLICATIONS: While independent sources of data
continue to show that the ACIR incorrectly classifies some children as not fully
immunised even with the third-dose assumption, its use seems appropriate for
reporting population trends in immunisation coverage. Earlier Medicare
registration and increased electronic reporting to the ACIR, together with
incentives for parents and providers to ensure complete ACIR records, should
eventually eliminate the need for the third-dose assumption.
PMID- 10777974
TI - Factors associated with delayed tobacco uptake among Vietnamese/Asian and Arabic
youth in Sydney, NSW.
AB - OBJECTIVE: To describe the smoking behaviour and possible reasons for delayed
uptake of tobacco smoking among Arabic and Vietnamese/Asian speaking senior
school students in Sydney METHOD: A descriptive study involving four adult in
depth interviews and five student focus groups plus a quantitative survey of
2,573 school students attending Years 10 and 11 from 12 high schools with high
Vietnamese and Arabic populations was conducted in Sydney in 1998. Self-reported
smoking behaviour and peer, parent, school and cultural background information
was collected. RESULTS: Students who smoke were more likely to have more than $20
a week pocket money, be from an English-speaking background, have no rules at
home about smoking, have family members who smoke, not feel close to their
father, spend three or more evenings a week out with friends, and have negative
perceptions of the school environment and of the level of teacher support. They
were less likely to smoke if they perceived their peers to be unsupportive.
CONCLUSIONS: These results confirm the delayed uptake of smoking among students
from a Vietnamese/Asian and Arabic-speaking backgrounds compared with those from
an English-speaking background. A number of family and school factors were
associated with smoking. IMPLICATIONS: Positive parental modelling, active
parenting including awareness of or supervision of student leisure time, strict
rules about not smoking and less pocket money are important strategies for
preventing smoking among all adolescents.
PMID- 10777975
TI - Mental health status of the South Australian population.
AB - OBJECTIVE: To determine, by the use of a telephone survey, the mental health
status of SA adults (18+ years) using the GHQ-28, SF-12 and self-report as
indicators of mental health, and to examine risk factors for mental health
morbidity. SAMPLE: A random representative sample of South Australian adults
selected from the Electronic White Pages. Overall, 2,501 interviews were
conducted (74.0% response rate). RESULTS: Overall, 19.5% of respondents had a
mental health problem as determined by the GHQ-28, 11.8% as determined by the
mental health component summary score of the SF-12 and 11.9% self-reported a
mental health condition. The percentage of people with a mental health problem
who had used a psychologist or a psychiatrist in the previous 12 months was 9.6%
for people diagnosed by the GHQ-28, 16.2% by SF-12 and 23.7% for self-report. The
logistic regression analyses undertaken to describe people with a mental health
problem as determined by the GHQ-28 and to describe people who visited a
psychologist or psychiatrist produced different age categories, demographic and
co-morbidity indicators. Variables found in both analyses included living in the
metropolitan area, being economically inactive and being a high user of health
services. CONCLUSIONS: One in five South Australian adults has a mental problem.
Although the prevalence is higher for younger age groups, older adults are more
likely to visit a psychologist or a psychiatrist. IMPLICATIONS: Telephone
interviewing produces robust indicators of the prevalence of mental health
problems and is a cost-effective way of identifying prevalence estimates or
tracking changes over time.
PMID- 10777976
TI - Regional variation in alcohol consumption in the Northern Territory.
AB - OBJECTIVE: To identify any regional variation in per capita consumption of
alcohol and the types of beverages consumed in the NT; and to estimate the
relative contributions to consumption by Aboriginal and non-Aboriginal people.
METHOD: Per capita consumption estimates were based on wholesale purchases of
alcohol by license and Census population data. Mean levels and the percentages of
each beverage type consumed were compared between regions and through time.
Estimates of per capita levels of consumption between Aboriginal and non
Aboriginal segments of the population were based on reports of the proportion of
frequent and occasional drinkers in each group and the ratio of consumption among
Aboriginal and non-Aboriginal drinkers. RESULTS: Mean quarterly per capita
consumption was higher in both the Lower Top End (4.22 litres) and the Central NT
(4.04 litres), and less in the Barkly (3.44 litres) than in the Top End (3.55
litres). Over the four-year period, consumption in the Top End rose 6.4%, but
dropped 22.5% in the Barkly. In the Lower Top End and the Central NT a larger
percentage of alcohol was consumed as cask wine than in the Top End. Before
licensing restrictions were introduced, this was also the case in the Barkly. In
the NT, per capita consumption among Aboriginal people is approximately 1.97
times, and among non-Aboriginal people about 1.43 times, the national average.
CONCLUSIONS: Alcohol consumption in the NT is greater than in Australia as a
whole and there is significant regional variation. The problem is not simply an
Aboriginal problem, and a broad range of strategies--including a component to
address regional variation--is required to reduce it.
PMID- 10777977
TI - Beating the grog: an evaluation of the Tennant Creek liquor licensing
restrictions.
AB - OBJECTIVE: To review the effectiveness of, and community attitudes towards,
increased restrictions on the availability of alcohol in Tennant Creek. METHOD:
Estimates of quarterly per capita consumption of pure alcohol by persons aged >
or = 15 years, admissions data from the local hospital, women's refuge and
sobering up shelter, and police data on detentions in custody and common offences
were compared for the 12 months prior and 24 months subsequent to the
introduction of the restrictions. A random sample survey of residents aged > or =
18 years was conducted to ascertain attitudes towards the restrictions. RESULTS:
Over the two years following the introduction of the restrictions, there was a
reduction of 19.4% in annual per capita consumption of pure alcohol. This was
accompanied by declines in: hospital admissions for acute alcohol-related
diagnostic related groups; and persons taken into police custody and the
proportions of offences reported on Thursdays. A majority of survey respondents
was in favour of retaining or strengthening the existing restrictions.
CONCLUSIONS: The restrictions were effective in reducing alcohol consumption and
acute related harm and had the support of the majority of people in Tennant
Creek. On the basis of this evidence, the NT Liquor Commission made a decision to
retain them. Restrictions do not provide a simple answer to the problems
associated with excessive alcohol consumption. However, they can be an effective
part of a broad public health strategy to deal with such problems.
PMID- 10777978
TI - Liquor licensing and community action in regional and remote Australia: a review
of recent initiatives.
AB - OBJECTIVE: To review the effectiveness of community-based initiatives involving
restrictions on alcohol availability in remote and regional locations in
Australia, and to assess their implications for other communities or towns
contemplating similar measures. METHODS: Findings from evaluations of community
initiatives in Tennant Creek (NT), Derby (WA), Halls Creek (WA), Elliott (NT) and
Curtin Springs (NT) are compared with respect to impact on alcohol consumption,
and on indicators of alcohol-related harm relating to public order, health and
well-being, and economic activities. The extent of community support for these
initiatives is also examined. RESULTS: Restrictions were found to have a modest
but real impact on alcohol consumption, and a significant impact on indicators of
alcohol-related harm, especially violence. Restrictions were also found to have
widespread community support, often qualified by a belief that other measures
were also required. CONCLUSIONS: Restrictions on availability are an effective
means of reducing alcohol-related harm at a local level and, depending upon the
processes involved in their introduction, are likely to have strong community
support, provided that other measures are also pursued. IMPLICATIONS: Five issues
are identified that are likely to arise in other settings where restrictions are
contemplated. These are: the issue of representativeness ('who speaks for the
community?'); selection of particular kinds of restrictions on availability;
selection of most appropriate additional measures; universal vs. selective
restrictions; and the role of liquor licensing authorities in imposing or
facilitating restrictions.
PMID- 10777979
TI - What harms do young Australians experience in alcohol-use situations?
AB - OBJECTIVE: An insight into the alcohol-related experiences of young students in
Perth, Western Australia, with particular emphasis to alcohol-related harm.
METHOD: The sample of 2,329 students (female: n = 1,089, male: n = 1,240) is a
school-based group selected using cluster sampling, with stratification by socio
economic area and represents 11 to 12 year olds' experiences with alcohol and
alcohol-related harm. The SHAHRP survey instrument was developed and pre-tested
to measure students' knowledge, attitudes, patterns and context of use, harms
associated with the students' own alcohol consumption and harms associated with
other people's use of alcohol and incorporates the students' perceptions of
alcohol-related harm. RESULTS: Nearly two-thirds of all young people consumed
alcohol under adult supervision; nearly 40% of all young males and 34% of all
young females drink alcohol in unsupervised situations; and a fifth of young
males consumed alcohol alone. Young males start drinking younger and consumed
alcohol more regularly than young females, and consumed more alcohol per
occasion. In the past 12 months, young males experienced more than five and young
females more than three alcohol-related harms associated with their own alcohol
consumption. They experienced a similar number of harms associated with other
people's use of alcohol. Unsupervised drinkers were nearly seven times more
likely to experience alcohol-related harm than supervised drinkers and nearly 13
times more likely to experience alcohol-related harm than non-drinkers.
CONCLUSION AND IMPLICATIONS: The results can help inform the development of
alcohol education programs for young people.
PMID- 10777980
TI - Is birthweight an appropriate health-outcome measure for Torres Strait Islander
babies?
AB - BACKGROUND: Although Torres Strait Islanders (TSIs) are often combined with
Aborigines, they are a distinct group and would prefer to be considered
separately. The Queensland Perinatal Data Collection (QPDC) has been the only
population-based, perinatal collection in Australia that has distinguished
between Aboriginal and TSI mothers. It provided a unique opportunity to compare
outcome measures based on birthweight in the TSI, Aboriginal and white
populations. TSIs were of particular interest because recent research from
overseas suggests that in groups with high rates of obesity and diabetes,
birthweight is not a valid outcome measure. This is of concern because outcome
measures based on birthweight have been proposed as a way of monitoring the
neonatal health of Indigenous Australians. METHODS: Retrospective analysis of 10
years of routine data from the QPDC. RESULTS: TSIs had a birthweight distribution
similar to that of whites, but mortality rates similar to those of Aborigines.
For birthweights between 2500 g and 4000 g, TSIs had mortality rates that were
2.5 times higher than those for whites (95% CI: 1.3 to 4.2). CONCLUSIONS:
Although birthweight is widely used, it is not necessarily a valid outcome
measure in all populations. For TSIs, maternal conditions such as obesity and
diabetes might cause changes in the uterine environment that produce heavier, but
not healthier babies.
PMID- 10777981
TI - The use of conjoint analysis to elicit community preferences in public health
research: a case study of hospital services in South Australia.
AB - AIMS: To demonstrate the use of conjoint analysis (CA) in public health research
through a survey of the South Australian community about aspects of their public
hospital services. METHODS: A series of focus groups determined the most
important attributes in choice of hospital services. These were built into a CA
survey, using the discrete choice approach. The survey was posted to a
representative sample of 700 South Australians. Theoretical validity, internal
consistency and non-response bias were all investigated. RESULTS: Some 231
individuals returned the questionnaire. The attribute, 'improvement in
complication rates' was positively associated with choice of hospital. Three
attributes were found to be negatively associated with such choice: 'waiting
times for casualty', 'waiting times for elective surgery' and, anomalously,
'parking and transport facilities'. 'Travel time' and the cost attribute,
'Medicare levy' were not statistically significant. Trade-offs between the
significant attributes were estimated, as were satisfaction or utility scores for
different ways of providing hospital services. Results concerning internal
consistency and internal validity were encouraging, but some potential for non
response bias was detected. CONCLUSION: A high premium is placed on the quality
of hospital care and members of the community are prepared to choose between
hospitals largely on the basis of outcomes and length of waiting times for
elective surgery and in casualty. IMPLICATIONS: CA can yield potentially policy
relevant information about community preferences for health services.
PMID- 10777982
TI - Inequitable distribution of general practitioners in Australia: estimating need
through the Robin Hood Index.
AB - OBJECTIVE: From Census data, to document the distribution of general
practitioners in Australia and to estimate the number of general practitioners
needed to achieve an equitable distribution accounting for community health need.
METHODS: Data on location of general practitioners, population size and crude
mortality by statistical division (SD) were obtained from the Australian Bureau
of Statistics. The number of patients per general practitioner by SD was
calculated and plotted. Using crude mortality to estimate community health need,
a ratio of the number of general practitioners per person: mortality was
calculated for all Australia and for each SD (the Robin Hood Index). From this,
the number of general practitioners needed to achieve equity was calculated.
RESULTS: In all, 26,290 general practitioners were identified in 57 SDs. The mean
number of people per general practitioner is 707, ranging from 551 to 1887.
Capital city SDs have most favourable ratios. The Robin Hood Index for Australia
is 1, and ranges from 0.32 (relatively under-served) to 2.46 (relatively over
served). Twelve SDs (21%) including all capital cities and 65% of all
Australians, have a Robin Hood Index > 1. To achieve equity per capita 2489 more
general practitioners (10% of the current workforce) are needed. To achieve
equity by the Robin Hood Index 3351 (13% of the current workforce) are needed.
CONCLUSIONS: The distribution of general practitioners in Australia is skewed.
Nonmetropolitan areas are relatively underserved. Census data and the Robin Hood
Index could provide a simple means of identifying areas of need in Australia.
PMID- 10777983
TI - Outcomes of an educational activity with Victorian GPs aimed at improving
knowledge and practices in relation to sexually transmissible diseases.
AB - OBJECTIVE: To measure the effect of a simple educational strategy for general
practitioners (GPs) on their knowledge and self-reported practice in relation to
sexually transmissible disease (STD) management. METHOD: In 1995, we surveyed 520
Victorian GPs; 444 (85%) responded. A sub-sample of 242 was sent an educational
package in relation to STD management that required them to reflect on their
performance in the survey in relation to that of the sample as a whole. Two
months after they had received the package, a brief follow-up questionnaire,
using a selection of questions from the first survey, was sent to these GPs.
RESULTS: Practitioners showed statistically significant improvements in knowledge
and self-reported practice for four of the six outcomes that were examined.
CONCLUSION: A relatively simple educational package for GPs had a high
participation rate and resulted in improvements in knowledge and self-reported
practice that could contribute to increased STD case finding in the general
practice setting. IMPLICATIONS: The key to enabling GPs to make a greater
contribution to improved STD control is to encourage them to be more active in
diagnosing and treating asymptomatic disease. For asymptomatic patients, sexual
history-taking and selective screening are important skills but there are
barriers to their implementation in the general practice setting. A key objective
of GP educational programs in relation to STDs is to increase their likelihood of
taking a sexual history and the significant increase in this measure for the
whole sample was encouraging.
PMID- 10777984
TI - Reliability and validity of women's recall of mammographic screening.
AB - OBJECTIVE: To assess the reliability and validity of self-reported attendance for
mammographic screening. METHODS: To assess reliability of recall of attendance
for a screening mammogram, 100 women selected at random were interviewed twice
(approximately one week apart). To assess validity, 127 women who reported having
a mammogram within the national breast screening program (BreastScreen Australia)
consented to having their reports verified by the national program. RESULTS: Test
retest reliability for the question "Have you ever had a mammogram?" was perfect
(agreement 100%, kappa 1). Validity was also high. About one-quarter of women
(24.4%) recalled the exact date of their last mammogram and a further third
(39.4%) correctly reported the month in which the mammogram was done. Almost all
(91.3%) women reported the mammogram date accurately to within 12 months of the
recorded date. CONCLUSIONS: These data suggest that Australian women provide
reliable and valid information in relation to mammographic screening attendance.
IMPLICATIONS: Self-reported data about attendance for mammographic screening are
likely to provide reliable and valid estimates for research and health services
evaluation purposes.
PMID- 10777985
TI - Hitting up in the top end: characteristics of needle exchange clients in Darwin.
AB - OBJECTIVE: Little is known about injecting drug use (IDU) and blood-borne viral
(BBV) infection in rural Australia. METHOD: These repeat cross-sectional studies
were conducted during a two-week period in July and October-November 1998 at the
Darwin needle exchange, with 129 and 121 respondents respectively. RESULTS: The
commonest drug of choice was heroin, but the commonest drug injected was
morphine. Self-reported sharing of needles and syringes was uncommon. Self
reported serostatus for HIV was high (8% and 11.4% respectively), but seemingly
mostly associated with sexual rather than IDU risk; for hepatitis C (HCV) status,
these were 54% and 37%. Among IDUs of Aboriginal or Torres Strait Islander (ATSI)
background, who made up 14% of the first round respondents, patterns of IDU and
of BBV infection were the same as among non-ATSI respondents. CONCLUSIONS: These
surveys reveal patterns of IDU in Darwin that have both similarities and
differences with those in the major urban centres in Australia. In the absence of
a comprehensive methadone maintenance program, many participate in a more or less
informal morphine substitution program. HIV is present among these IDUs, and the
risks of further sexual transmission may be high. IMPLICATIONS: These surveys
confirm the presence among injecting drug users in Darwin of HIV, HBV and HCV,
and of the risk for further spread of these viruses. Control of blood-borne virus
transmission among IDUs requires an even greater commitment to abolishing sharing
of needles and syringes, and therefore continued support and enhancement of
needle and syringe availability.
PMID- 10777986
TI - Lipoproteins, diabeto-genicity, age and risk of diabetes mellitus death.
AB - OBJECTIVE: To examine the clinical significance of a specific relationship
between very low density lipoprotein (VLDL) and high density lipoprotein (HDL),
namely their differential, in relation to Type 2 non-insulin dependent diabetes
mellitus (NIDDM). METHODS: The study subjects were 300 female and 300 male
patients of doctors in city and rural New South Wales referred for lipid studies.
Their clinical notes suggested a relationship of VLDL-HDL to diabetes mellitus
(DM) and it was therefore hypothesised that this expression is a functional
measure of diabeto-genicity. RESULTS: By incorporation of age, a calculated
measure of risk of overt DM and consequent death can be derived. This is
confirmed by comparing the age incidence of this risk function with the age
incidence of death attributed to DM in the Australian population to give a simple
linear correlation. The principal conclusion is drawn from a mathematical model
of the population incidence of DM in terms of VLDL, HDL and age. CONCLUSION: From
this model springs the inference that NIDDM is a cumulative dyslipidaemia-over
time process. If this inference is correct, NIDDM can properly be viewed as a
societal disease of which all run a measurable risk that increases with age and
from which all will die in the long term who do not die sooner from another
cause. IMPLICATIONS: The implications for public health are the ability to
identify the individuals at raised risk before DM becomes symptomatic by
lipoprotein screening, and the ability to lower risk of DM over the whole
population by preventive measures with increased longevity for all.
PMID- 10777987
TI - Daily mortality in relation to weather and air pollution in Christchurch, New
Zealand.
AB - OBJECTIVE: To investigate the relationship between the daily number of deaths,
weather and ambient air pollution. METHOD: An ecological study. We assembled
daily data for the city of Christchurch, New Zealand (population 300,000) from
June 1988 to December 1993. We used Poisson regression models, controlling for
season using a parametric method. RESULTS: Above the third quartile (20.5 degrees
C) of maximum temperature, an increase of 1 degree C was associated with a 1%
(95% CI: 0.4 to 2.1%) increase in all-cause mortality and a 3% (0.1 to 6.0%)
increase in respiratory mortality. An increase in PM10 of 10 micrograms/m3 was
associated (after a lag of one day) with a 1% (0.5 to 2.2%) increase in all-cause
mortality and a 4% (1.5 to 5.9%) increase in respiratory mortality. We found no
evidence of interaction between the effects of temperature and particulate air
pollution. CONCLUSIONS: High temperatures and particulate air pollution are
independently associated with increased daily mortality in Christchurch. The fact
that these results are consistent with those of similar studies in other
countries strengthens the argument that the associations are likely to be causal.
IMPLICATIONS: These findings contribute to evidence of health consequences of
fuel combustion, both in the short term (from local air pollution) and in the
long term (from the global climatic effects of increased atmospheric CO2).
PMID- 10777988
TI - Anonymous linkage of New Zealand mortality and Census data.
AB - BACKGROUND: The New Zealand Census-Mortality Study (NZCMS) aims to investigate
socio-economic mortality gradients in New Zealand, by anonymously linking Census
and mortality records. OBJECTIVES: To describe the record linkage method, and to
estimate the magnitude of bias in that linkage by demographic and socio-economic
factors. METHODS: Anonymous 1991 Census records, and mortality records for
decedents aged 0-74 years on Census night and dying in the three-year period 1991
94, were probabilistically linked using Automatch. Bias in the record linkage was
determined by comparing the demographic and socio-economic profile of linked
mortality records to unlinked mortality records. RESULTS: 31,635 of 41,310
(76.6%) mortality records were linked to one of 3,373,896 Census records. The
percentage of mortality records linked to a Census record was lowest for 20-24
year old decedents (49.0%) and highest for 65-69 year old decedents (81.0%). By
ethnic group, 63.4%, 57.7%, and 78.6% of Maori, Pacific, and decedents of other
ethnic groups, respectively, were linked. Controlling for demographic factors,
decedents from the most deprived decile of small areas were 8% less likely to be
linked than decedents from the least deprived decile, and male decedents from the
lowest occupational class were 6% less likely to be linked than decedents from
the highest occupational class. CONCLUSION: The proportion and accuracy of
mortality records linked was satisfactorily high. Future estimates of the
relative risk of mortality by socio-economic status will be modestly under
estimated by 5-10%.
PMID- 10777989
TI - Use of self-report to monitor overweight and obesity in populations: some issues
for consideration.
AB - OBJECTIVE: To examine the validity of self-reported height and weight data
reported over the telephone in the 1997 NSW Health Survey, and to determine its
accuracy to monitor overweight and obesity in population surveys. METHOD: Self
reported and measured heights and weights were collected from 227 people living
in Western Sydney, who had participated in the NSW Health Survey 1997. RESULTS:
Self-reported (SR) weights and heights led to misclassification of relative
weight status. BMI, based on measured weights and heights, classified 62% of
males and 47% of females as overweight or obese, compared with 39% and 32%,
respectively, from self-report. CONCLUSIONS: Caution should be used when
interpreting SR height and weight data from surveys, because BMI derived from
these is likely to underestimate the true prevalence of overweight and obesity.
IMPLICATIONS: SR data have a place in nutrition monitoring because they are
relatively inexpensive and easy to collect. However, classifying people into
weight categories on the basis of accepted cut-points, using SR heights and
weights, yields inaccurate prevalence estimates. Periodic sub-studies of the
validity of SR heights and weights are needed to indicate the extent to which the
validity of SR is changing.
PMID- 10777990
TI - It's time: record linkage--the vision and the reality.
AB - OBJECTIVE: To examine reasons for the minimal use of Australian administrative
health data for research and evaluation. METHOD: Legislative, organisational,
social and political barriers in Australia are described. RESULTS: System changes
are identified that would support the implementation of an evaluation-oriented
health data collection system. A Universal Patient Identifier is essential.
Leadership and funding at the federal level will be required to ensure the co
ordinated introduction of a rational and integrated health data system in
Australia. CONCLUSIONS: Health data in Australia is not currently collected in a
manner that allows the assessment of health outcomes. It is time to change the
basis of health data collection from accounting to health outcomes evaluation and
to reorganise the system to support this. IMPLICATIONS: If appropriate national
health data were available, research and evaluation of services could be
undertaken and treatment outcomes and adverse events could be monitored. Such
information could provide a basis for targeted clinical trials and provide
evidence for best clinical practice.
PMID- 10777991
TI - The emperor's quality clothes: for goodness' sake, let's take the strain off the
word quality!
AB - Quality is a much used word in health care. It clearly has positive connotations.
Yet there is less than clarity in the literature as to what it means. This
article suggests that quality has to have something to do with 'goodness' and
indeed 'betterment'. It then argues that it follows that quality cannot be
defined before we have sorted out 'good' and 'better'. The author appeals for
these terms to be defined.
PMID- 10777992
TI - Tobacco taxes are no insurance against litigation.
PMID- 10777993
TI - The potential public health impact of global environmental change.
PMID- 10777994
TI - Outbreak of cryptosporidiosis in Lancashire.
PMID- 10777995
TI - Sexually transmitted diseases quarterly report: genital chlamydial infection,
ectopic pregnancy, and syphilis in England and Wales.
PMID- 10777996
TI - AIDS and HIV infection in the United Kingdom: monthly report.
PMID- 10777997
TI - Domestic violence and children: analysis and recommendations.
PMID- 10777998
TI - Prevalence and effects of child exposure to domestic violence.
AB - In recent years, researchers have focused attention on children who are exposed
to domestic violence. Although presently there are no scientifically credible
estimates of the national prevalence of children exposed to domestic violence,
existing data suggest that large numbers of American children are affected. This
article discusses the limitations of current databases and describes a promising
model for the collection of reliable and valid prevalence data, the Spousal
Assault Replication Program, which uses data collected through collaboration
between police and university researchers. Research examining the effects of
childhood exposure to domestic violence is also limited by a range of
methodological problems. Despite this, however, sufficient evidence from the body
of studies exists to conclude that such exposure has adverse effects. The
specific effects may differ depending on a host of variables, such as the
children's ages, the nature and severity of the violence, the existence of other
risk factors in the children's lives (for example, poverty, parental substance
abuse), and whether the children are also directly physically abused. In general,
childhood exposure to domestic violence can be associated with increased display
of aggressive behavior, increased emotional problems such as depression and/or
anxiety, lower levels of social competence, and poorer academic functioning. A
scientifically credible body of research on the prevalence and effects of
childhood exposure to domestic violence is necessary to promote the development
of effective interventions and to permit the proper channeling of public and
private funds. This article identifies some of the steps that can be taken to
build the research capacity necessary to obtain the needed data.
PMID- 10777999
TI - The impact of violence on children.
AB - Existing research on the effects of children's exposure to violence covers a
broad range of community, family, and media violence. This research is relevant
and useful to an examination of domestic violence in two key ways. First,
understanding how exposure to various types of violence affects children and what
best enables them to cope can point to important considerations when trying to
help children cope with exposure to domestic violence in particular. And second,
many families experiencing domestic violence are exposed to other types of
violence as well. Exposure to violence on multiple levels can affect the parents'
behavior and can compound the effects on children. This article begins with an
overview of the extent of children's exposure to various types of violence, and
then examines what is known about the effects of this exposure across the
developmental continuum. Key protective factors for children exposed to violence
are examined. Research indicates that the most important resource protecting
children from the negative effects of exposure to violence is a strong
relationship with a competent, caring, positive adult, most often a parent. Yet,
when parents are themselves witnesses to or victims of violence, they may have
difficulty fulfilling this role. In the final section, directions for future
research are discussed.
PMID- 10778000
TI - The impact of federal and state laws on children exposed to domestic violence.
AB - Until recently, few federal and state laws specifically addressed the needs of
children in families in which there is domestic violence. Yet, many laws,
particularly in the areas of domestic violence, family law, child welfare,
welfare reform, and immigration, can have profound effects on the well-being of
these children. The growing understanding by legislators and policymakers of the
potential harms of domestic violence to children has resulted in recent years in
statutory changes, particularly at the state level. However, laws that are
enacted and implemented with inadequate knowledge of the complex dynamics of
domestic violence and the unique issues battered parents and their children face
may have unintended negative consequences for the children these laws are
designed to protect. Collaboration across public and private social service
agencies and domestic violence training for court personnel are examples of
efforts that can bridge this knowledge gap and increase the likelihood that the
protective intent of the laws is carried out in practice. This article analyzes
current and proposed federal and state civil laws to better understand their
potential impact on children affected by domestic violence. A companion article
by Lemon in this journal issue examines court decisions related to these laws.
PMID- 10778001
TI - The legal system's response to children exposed to domestic violence.
AB - Historically, the legal system has not responded adequately, if at all, to cases
involving domestic violence. In the past two decades, U.S. courts and law
enforcement agencies have increasingly acknowledged the seriousness of domestic
violence and have developed responses to it. Unfortunately, the legal system has
been slower to recognize the impact of domestic violence on children. This
article highlights four key areas of case law in which the courts have begun, in
varying degrees, to examine the effects of domestic violence on children: child
custody and visitation, restraining orders, failure to protect a child from harm,
and termination of parental rights. A survey of appellate cases since 1990,
though not representative of all cases, shows an ongoing need for mandatory
judicial training on domestic violence and its effects on children, greater
clarity about how to interpret relevant laws, changes in the laws to better serve
children, and the renewal of national funding for legal aid programs. Courts and
law enforcement agencies in some locales have implemented innovative programs to
improve their interventions with children exposed to domestic violence. These
programs include coordinated court responses, child development training for
police officers, multidisciplinary team approaches, and supervised visitation
centers. However, few of these programs have been evaluated for overall
effectiveness in improving outcomes for children. Better evaluation is needed, as
is ongoing funding for the replication of successful programs nationwide. A
companion article by Matthews in this journal issue examines federal laws and
policies with regard to domestic violence and children, and reviews many of the
state statutes on which the court decisions discussed here are based.
PMID- 10778002
TI - Child protective services and domestic violence.
AB - Studies estimate that domestic violence is present in at least one-third of the
families involved in child protective services (CPS). Yet, until recently, CPS
has not directly addressed domestic violence in its handling of child abuse and
neglect cases. By the same token, domestic violence programs have historically
emphasized services for battered women, with limited understanding of the child
safety goals of CPS. Despite these historical differences, collaborative efforts
between CPS and domestic violence service programs are emerging based on a common
goal of safety from violence for all family members. Innovative strategies
include the use of domestic violence specialists in a variety of child protection
settings for case consultation and for support to the battered women, direct
referrals of battered women from domestic violence programs to family
preservation services, and cross-training of CPS workers and domestic violence
service providers. A survey of state CPS administrators and domestic violence
coalition directors conducted for this article revealed that although there is
mutual interest in greater collaboration, such efforts remain limited. New
forums, such as CPS citizen review panels and community-based CPS partnerships,
hold promise for further collaboration. Critical to successful strategies are
supportive agency leadership, greater trust and understanding across systems, a
recognition of common goals, and a willingness to change policies and practice.
PMID- 10778003
TI - Community-based domestic violence services.
AB - Community-based domestic violence services have grown significantly since their
emergence in the 1970s. Now more than 2,000 in number, domestic violence
organizations have expanded their range of programs. In addition to crisis
oriented services, such as telephone hot lines and temporary shelter, many of
these agencies provide legal, health, mental health, or vocational services or
referrals, and assistance in finding housing, relocating, and planning for
safety. Most recently, in response to increasing knowledge about the deleterious
effects of exposure to domestic violence on children, community-based service
providers have developed programs addressing children's mental health, health,
educational, and safety needs. This article describes and analyzes trends in
service delivery by these community-based organizations to children affected by
domestic violence. It concludes that, although there has been significant growth
in services, substantial segments of the target population still are not reached,
and most organizations do not yet have a sufficient range of services to meet
children's diverse needs. Challenges posed by inadequate funding, needs for
specialized staffing, and a dearth of data on the efficacy of current
intervention programs hamper domestic violence service providers' ability to meet
children's needs. However, this article highlights promising new directions in
service delivery. Community-based domestic violence organizations increasingly
are using innovative strategies to address children's service needs. These
agencies are expanding community outreach efforts and attempts to educate the
public and professionals about domestic violence and children. In addition, these
organizations are building important collaborative relationships with other
agencies concerned with children's welfare, such as child protective services,
law enforcement, schools, and health care facilities. These and related
developments suggest cautious optimism that future years will see continuing
progress in attempts by community-based organizations to address the needs of
children whose well-being is jeopardized by their exposure to domestic violence.
PMID- 10778004
TI - Health care system responses to children exposed to domestic violence.
AB - The health care system has only recently adopted protocols and training to enable
practitioners to identify and respond to victims of domestic violence. Currently,
most hospitals have domestic violence protocols in place, although training in
the use of protocols is less routine. However, because the provision of health
care focuses on the treatment of the individual, the well-being of the children
of adult domestic violence victims has received little attention in adult health
care settings. Pediatricians do not routinely receive training in domestic
violence identification and do not see responding to battered mothers as within
the purview of their practice. Innovative programs in children's hospitals in
Boston, Massachusetts, and San Diego, California, recognize that the safety of
children is integrally tied to the safety of their mothers. These programs
identify abused children whose mothers are the victims of domestic violence and
provide advocacy and support that allow mothers and children to remain together
in most instances. Little is known about the health impacts of teen dating
violence, and opportunities for screening exist in the settings where teens
receive health care. Likewise, prenatal visits provide regularized opportunities
for domestic violence screening. Integrating the health care needs of mothers and
children from violent households will require continued and expanded training,
collaboration with community institutions, and improvements in insurance
reimbursements to cover the costs of needed services.
PMID- 10778005
TI - Mental health services for children who witness domestic violence.
AB - Exposure to domestic violence has significant negative repercussions for
children's social, emotional, and academic functioning. In the past decade,
mental health professionals have developed treatment programs and approaches
aimed at mitigating these deleterious effects. Their efforts, however, are often
hampered by difficulty identifying and gaining access to the target population
because the occurrence of domestic violence remains a family secret in many
households. Clinicians and researchers have published descriptions of group and
individual therapy approaches for children who witness domestic violence. These
approaches share several goals: promoting open discussion about children's
experiences with domestic violence, helping children to deal with the emotions
and consequences that follow such exposure, reducing the problematic symptoms
children experience, strengthening children's relationships with their nonabusive
caregivers, and helping children and their families to create and maintain
relationships and living situations that are free from violence and abuse. One
limitation of the literature describing these interventions is the absence of
controlled outcome studies demonstrating the effects of these programs, in the
short and long terms. Thus, development of such evaluative components is an
important future direction for this field. Some of the other challenges that
confront clinicians include working with children's families, addressing
children's complex and intense emotional experiences, and determining whether
children have themselves been victims of abuse or neglect (and then interfacing
with child protective services).
PMID- 10778006
TI - Emerging strategies in the prevention of domestic violence.
AB - Responses to domestic violence have focused, to date, primarily on intervention
after the problem has already been identified and harm has occurred. There are,
however, new domestic violence prevention strategies emerging, and prevention
approaches from the public health field can serve as models for further
development of these strategies. This article describes two such models. The
first involves public health campaigns that identify and address the underlying
causes of a problem. Although identifying the underlying causes of domestic
violence is difficult--experts do not agree on causation, and several different
theories exist--these theories share some common beliefs that can serve as a
foundation for prevention strategies. The second public health model can be used
to identify opportunities for domestic violence prevention along a continuum of
possible harm: (1) primary prevention to reduce the incidence of the problem
before it occurs; (2) secondary prevention to decrease the prevalence after early
signs of the problem; and (3) tertiary prevention to intervene once the problem
is already clearly evident and causing harm. Examples of primary prevention
include school-based programs that teach students about domestic violence and
alternative conflict-resolution skills, and public education campaigns to
increase awareness of the harms of domestic violence and of services available to
victims. Secondary prevention programs could include home visiting for high-risk
families and community-based programs on dating violence for adolescents referred
through child protective services (CPS). Tertiary prevention includes the many
targeted intervention programs already in place (and described in other articles
in this journal issue). Early evaluations of existing prevention programs show
promise, but results are still preliminary and programs remain small, locally
based, and scattered throughout the United States and Canada. What is needed is a
broadly based, comprehensive prevention strategy that is supported by sound
research and evaluation, receives adequate public backing, and is based on a
policy of zero tolerance for domestic violence.
PMID- 10778007
TI - Domestic violence and children. A selected bibliography.
PMID- 10778008
TI - Introduction to the special section on contemporary relational psychologies and
group therapy.
PMID- 10778009
TI - From identified patient to identifiable group: the alchemy of the group as a
whole.
AB - Group-as-a-whole theory is a relational paradigm of some complexity. Despite the
growing popularity of this perspective, there is abiding confusion about the
essence of group-as-a-whole practice and whether the approach attends
sufficiently to members and part processes. The threefold aims of this article
are to (a) show how group-centered thinking differs essentially from traditional
psychodynamic theory that relies heavily on familial dynamics, interpretation,
and transference analysis; (b) present the mind-set and working principles for a
generic treatment that specifically utilizes collective forces generated in the
context of the group matrix; and (c) compare and contrast the thrust of recent
dyadic relational therapies with group therapy generally and the group-as-a-whole
approach more particularly. The relationship between the whole (group) and its
parts (members and what they bring) is detailed and demonstrated as it appears in
the context of fused, affiliated, fragmented, and differentiated groups.
PMID- 10778010
TI - Intersubjectivity and narcissism in group psychotherapy: how feedback works.
AB - In group psychotherapy, inter-subjectivity is complicated by the number and
quality of therapist-member, member-member, and member-group relations. Inter
member feedback structures the relational process. However, fears of narcissistic
injury engender resistance to this form of engagement. The nature of the
narcissistic belief system that motivates such resistance is discussed. Then, two
models of feedback are presented: the cybernetic and the inter-subjective. In the
cybernetic model, feedback is intended to inform recipients about themselves and
to change their behavior accordingly. As such, this model is consistent with
narcissistic beliefs in the power of others' perceptions to control one's being,
identity, or value. The inter-subjective model focuses, instead, on what feedback
tells recipients about their donors' worlds. This model and some of its
parameters are exemplified clinically.
PMID- 10778011
TI - The use of the self in group leadership: a relational perspective.
AB - This article, written from a relational perspective, describes a shift that is
taking place in the thinking of many psychodynamically oriented psychotherapists
regarding the practice of therapy and the implications it has for group
therapists. The shift, from one-person to two-person and multi-person theory, has
particular importance for group leaders since it recommends making the subjective
involvement of the therapist in the interactional field of the group much more a
part of the treatment process. Theory and research on the use of
countertransference, non-interpretive interventions, humor, and spontaneity by
the leader are reviewed and vignettes are presented to illustrate the application
of these ideas. Guidelines regarding the application of such ideas in group
therapy are also discussed.
PMID- 10778012
TI - Contributions of object relations theory and self psychology to relational
psychology and group psychotherapy.
AB - Object relations theory and self psychology are psychoanalytic perspectives that
are especially concerned with interpersonal relations and their mental
representations. Object relations theory began as an intrapsychic "singleton"
psychology with the work of Freud and Melanie Klein. It subsequently evolved into
a multi-person psychology with the work of Bion on groups, as well as the
clinical and theoretical contributions of Winnicott and Fairbairn. Kohutian self
psychology, which emerged later, has been interested in the relations between the
self and significant others as mirroring and idealizing "self-objects."
Stolorow's "inter-subjective perspective" emerged from self psychology as a full
fledged multi-person point of view. This article considers the significance of
contemporary object relations theory and self psychology as relational, multi
person perspectives in terms of their application to group psychotherapy,
focusing upon the group-as-a-whole, projective identification, transitional space
and object, and self/self-object relations as particularly useful constructs. A
clinical vignette is provided.
PMID- 10778013
TI - Narcissistic leadership in psychotherapy groups.
AB - Narcissistic leaders in groups are capable of impeding progress of their patients
and, at worst, can produce iatrogenic effects. Significant interferences may
occur when the therapist is unable to tolerate the expression of negative
transferences and when they need to be idealized by their patients. The rare
therapist who is a malignant narcissist is capable of inflicting severe damage by
sadistically exploiting the group to satisfy his or her own pathological needs.
Less severe interferences consist of inhibition in making transference
interpretations, reluctance to seek out training or supervision, and a difficulty
in protecting patients against being scapegoated as a result of the displacement
of negative feelings toward the therapist onto a member. The universality of
these issues among therapists is discussed and possible remediation is proposed.
PMID- 10778014
TI - Individual and group psychotherapy with infertile couples.
AB - After reviewing some of the relevant literature, the writers proceed to describe
a new development in psychotherapy for couples presenting with relatively
unexplained infertility. Several couples who had failed to achieve conception
(despite the use of assisted reproductive techniques and personal psychotherapy)
were brought together into a supportive-expressive group led by the writers, an
experienced analytic cotherapy couple. An interesting outcome is described, and
mention made of current plans for a future research project.
PMID- 10778015
TI - Response to special issue on group supervision of group psychotherapy.
PMID- 10778017
TI - New book chronicles history of medicine in Iowa
PMID- 10778016
TI - High-quality, affordable health care.
PMID- 10778018
TI - Old law, new bite mandatory abuse training.
PMID- 10778020
TI - College binge drinking in the 1990s: a continuing problem. Results of the Harvard
School of Public Health 1999 College Alcohol Study.
AB - In 1999, the Harvard School of Public Health College Alcohol Study resurveyed
colleges that participated in the 1993 and 1997 surveys. Responses to mail
questionnaires from more than 14,000 students at 119 nationally representative 4
year colleges in 39 states were compared with responses received in 1997 and
1993. Two of 5 students (44%) were binge drinkers in 1999, the same rate as in
1993. However, both abstention and frequent binge-drinking rates increased
significantly. In 1999, 19% were abstainers, and 23% were frequent binge
drinkers. As before, binge drinkers, and particularly frequent binge drinkers,
were more likely than other students to experience alcohol-related problems. At
colleges with high binge-drinking rates, students who did not binge drink
continued to be at higher risk of encountering the second-hand effects of others'
heavy drinking. The continuing high level of binge drinking is discussed in the
context of the heightened attention and increased actions at colleges. Although
it may take more time for interventions to take effect, the actions college
health providers have undertaken thus far may not be a sufficient response.
PMID- 10778019
TI - The political, social, and public health problems of binge drinking in college.
PMID- 10778021
TI - A campus-community coalition to control alcohol-related problems off campus: an
environmental management case study.
AB - The authors report on the effects of a university and community coalition in
preventing problems related to college students' off-campus drinking. The Albany,
New York, Committee on University and Community Relations used strategies based
on an environmental-management approach that focuses on changing the environment
in which individuals make decisions about alcohol consumption and related
behaviors. Committee initiatives included improving enforcement of local laws and
ordinances, creating a safety-awareness campaign for off-campus students, and
developing a comprehensive advertising and beverage-service agreement with local
tavern owners. The initiatives were associated with a decline in the number of
alcohol-related problems in the community, as indicated by decreases in the
number of off-campus noise ordinance reports filed by police and the number of
calls to a university-maintained hotline for reporting off-campus problems. An
environmental management approach, the authors suggest, has promise as an
effective means of preventing alcohol-related problems among college students.
PMID- 10778022
TI - What colleges are doing about student binge drinking. A survey of college
administrators.
AB - In 1999, the Harvard School of Public Health College Alcohol Study surveyed 734
US college administrators to learn what colleges were doing to prevent binge
drinking. Respondents rated the severity of student alcohol-abuse problems and
described prevention efforts and institutional investments in prevention
infrastructure. Prevention practices were widespread in the areas of general
education about alcohol, use of policy controls to limit access to alcohol,
restricting advertising at home-game sporting events, and allocation of living
space to alcohol-free dormitories. Programming was less prevalent for more
targeted alcohol education, outreach, and restrictions on alcohol advertising in
campus media. Nationally, most of the surveyed colleges reported having a campus
alcohol specialist, many had task forces, and about half were performing in-house
data collection. Less common were program evaluations, community agreements, or
neighborhood exchanges. Prevention practices varied with institutional
characteristics and the surveyed administrators' perceptions of the severity of
alcohol problems.
PMID- 10778023
TI - Suicide ideation among US college students. Associations with other injury risk
behaviors.
AB - Suicide, the endpoint of a continuum that begins with suicide ideation, is the
third leading cause of death among the US college-aged population. The first and
second leading causes of death among this age group, unintentional injury and
homicide, may also be linked to suicide ideation. We used data from the National
College Health Risk Behavior Survey to examine the association between suicide
ideation and injury-related behaviors among 18- to 24-year-old college students.
Students who reported suicide ideation were significantly more likely than
students who did not report considering suicide to carry a weapon, engage in a
physical fight, boat or swim after drinking alcohol, ride with a driver who had
been drinking alcohol, drive after drinking alcohol, and rarely or never used
seat belts. Given this clustering of injury-related risk behaviors, college
prevention programs should aim to reduce risks for injuries comprehensively,
rather than addressing each risk behavior separately.
PMID- 10778024
TI - In praise of feedback: an effective intervention for college students who are
heavy drinkers.
AB - The efficacy of brief motivational feedback to reduce drinking among college
students has been reported by several researchers. As an extension of this
theoretical and applied framework, the author tested the use of mailed feedback
to influence the drinking behavior of students self-identified as moderate-to
heavy drinkers in two randomized trials. A 6-week follow-up of the efforts
suggested the efficacy of the feedback intervention at reducing alcohol
consumption. The feedback mechanism used in the studies is described in detail
and possible reasons for its efficacy are explored. In light of the cost
effective nature of this intervention, it may warrant a place in larger campus
prevention programs.
PMID- 10778025
TI - Living with chronic venous leg ulcers: a descriptive study of knowledge and
functional health status.
AB - A descriptive design was used to identify the functional health status and
knowledge level of individuals living at home with chronic venous leg ulcers (N =
21). Limitations in physical function and vitality were moderate to severe,
impacting on study participants' productive activities and activities of daily
living. Severe to moderate pain was experienced by 19% of the participants. In
addition, knowledge deficits were apparent regarding the cause and treatment of
leg ulcers. Findings of this study suggest the importance of assessing these
factors in addition to the wound when caring for individuals in the community
with chronic venous leg ulcers.
PMID- 10778026
TI - Improving readability of patient education materials.
AB - Functional illiteracy contributes to negative long-term health consequences for
patients who must understand and adhere to complex health care instructions and,
therefore, is of primary importance to community health nurses. This problem is
compounded when English is the patient's second language. A process for improving
patient education materials (PEMs) through adaptation or creation of new
materials to meet the health needs of diverse groups is presented. The process
was applied to a popular health education program used with school-age children
and their parents to teach them home management of asthma. Target parents were
known to read at a 5th-grade level, and English was a second language for many of
them. Therefore, extensive revision of the existing PEMs was required. The steps
to successful revision included assessing readability and comprehensibility,
editing the materials, and evaluating the new PEMs to determine the effectiveness
of the revision measures.
PMID- 10778027
TI - End-of-life care directives among African Americans: lessons learned--a need for
community-centered discussion and education.
AB - African Americans appear to be less likely to know about advance directives and,
even if known, to complete them. This small, exploratory study used a community
centered educational group discussion to assess African Americans' knowledge,
attitudes, and utilization of end-of-life care directives before the occurrence
of a health crisis. McNemar and paired t tests were computed to detect immediate
changes in participants' initial and final perceptions about advance directives
before and after the group discussion. Findings indicated further education is
needed to clarify the terms used for advance directives. African Americans rely
on a family-centered approach to end-of-life decision making, especially in the
absence of written advance directives. They are open to community forums to
discuss end-of-life care choices if presented the opportunity. Culture plays an
essential role in this issue. There is a need for community health nurses to
develop community-based educational programs that are not a "one-size-fits-all"
approach.
PMID- 10778028
TI - Implementation and evaluation of church-based health fairs.
AB - From a comprehensive, community health-needs assessment based on the Neuman
Systems Model (Neuman, 1995), cardiovascular disease was identified as the
priority health concern in one quadrant of a small Midwestern city. The Plan, Do,
Check, Act program planning model (Dees & Garcia, 1995) was the basis for the
planning, implementation, and evaluation of a mini cardiovascular health fair
held at 3 churches. Congruence of the program planning model with the roles of
the clinical specialist in community health nursing is discussed, followed by a
discussion of the health fair goals and objectives, implementation, and formative
and summative evaluations.
PMID- 10778029
TI - Effectiveness of a cardiovascular health promotion education intervention on the
attitudes of urban African American school-age children.
AB - African American children are at risk for high rates of morbidity and mortality
associated with cardiovascular (CV) disease as they become adults, yet little is
known about the effectiveness of CV risk-reduction interventions in African
American children. This study explored the effectiveness of a concentrated CV
health promotion educational program on health-related attitudes of 76 African
American children enrolled in a mid-southern school system. The Children's
Cardiovascular Health Promotion Attitude Scale was used to examine differences in
attitude prior to and 2 weeks following a focused health education intervention.
Results demonstrate that children have preconceived attitudes regarding practice
of health behaviors and that these attitudes are modifiable with age and
developmental level specific educational interventions. Findings indicate the
need for health care providers to assume more active roles in reducing the risk
of future CV disease and death in African Americans through health promotion
education of individuals who influence the development of children's attitudes.
PMID- 10778030
TI - Relationship between breast milk feeding and atopic dermatitis in children.
AB - OBJECTIVE: To determine whether or not the breast milk feeding has a role in the
prevalence of atopic dermatitis among children. METHODS: The target population of
the study was all children participating in health check-up program for 3-year
old children in 60 municipalities locating 10 selected prefectures during
designated 2 months between October and December 1997. Using a questionnaire,
information on nutrition in infants (breast milk only, bottled milk only, or
mixed), parity, mothers' age at birth, and a history of atopic dermatitis was
obtained. Besides, data on potential confounding factors were obtained. RESULTS:
Questionnaires from 3856 children (81.6% of those who were to participate in the
programs, and 96.4% of children who participated them) were analyzed. After the
adjustment for all potential confounding factors using unconditional logistic
models, the risk of atopic dermatitis was slightly higher among children with
breast milk (odds ratio [OR] = 1.16 with 95% confidence interval [CI] 0.96-1.40).
Mothers' age at birth (OR for those who were more than 30 years or older in
comparison with those who were younger than 30 years = 1.15; 95% CI, 0.96-1.37)
and those with second or later parity orders (OR = 1.14, 95% CI; 0.95-1.35)
showed odds ratios that were higher than unity without statistical significance.
CONCLUSION: Breast milk elevates the risk of atopic dermatitis slightly without
statistical significance; the risk may be, however, higher in children in second
or later parity orders.
PMID- 10778031
TI - Prevalence of sleep disturbance and hypnotic medication use in relation to
sociodemographic factors in the general Japanese adult population.
AB - This study was the first nationwide population-based study to estimate the
prevalence rates of sleep disturbance and hypnotic medication use in the general
Japanese adult population. In 1997, 2,800 Japanese adults aged 20 years and over
were randomly selected from the 1995 Census and 1,871 were examined using the
Pittsburgh Sleep Quality Index. The respective estimated overall prevalences of
insomnia (INS), difficulty initiating sleep (DIS), difficulty maintaining sleep
(DMS), poor perceived quality of sleep (PQS) and hypnotic medication use (HMU)
were 17.3%, 8.6%, 12.9%, 17.8%, and 3.5% in males and 21.5%, 12.6%, 16.2%, 20.2%
and 5.4% in females. Among males, DIS (OR = 2.76) and PQS (OR = 2.12) were
associated with never having married. DMS was associated with being 60 years and
older (OR = 2.68) or divorced/separated (OR = 3.74). Among females, DMS was
associated with being widowed (OR = 1.65), unemployed (OR = 1.60), 40 to 59 years
old (OR = 0.57) or never having married (OR = 0.39). DIS was associated with
being widowed (OR = 1.67) or unemployed (OR = 1.58). HMU was associated with
advancing age (OR = 8.26-10.7), being widowed (OR = 2.12) or never having married
(OR = 2.84). PQS was associated with advancing age (OR = 0.63-0.50). Our study
showed sleep disturbance and hypnotic medication use were prevalent among
Japanese adults and some sociodemographic factors contributed to them.
PMID- 10778032
TI - Sleep patterns and total mortality: a 12-year follow-up study in Japan.
AB - A population-based cohort study was conducted to assess the relationship between
total mortality and self-reported sleep patterns as regards not only to sleep
duration but also subjective sleep quality. A total of 5,322 inhabitants in Gifu
Prefecture, Japan, completed a self-administered questionnaire on health status
and lifestyles including habitual sleep patterns, and were followed-up for an
average of 11.9 years. Relative risks were computed by using Cox proportional
hazards models. Both longer and shorter sleep, compared to 7-8 hour-sleep, was
related to significantly increased risk of total mortality in males (relative
risk [RR] for > or = 10 hours = 1.94, and RR for < 7 hour = 1.90), but not in
females. Females complaining of poor awakening state experienced a higher
mortality risk compared to those who woke up normally (RR: 1.97). Males who
usually fell asleep easily showed a marginally lower mortality risk compared to
those who fell asleep normally (RR: 0.70). Female users of sleeping pills were at
an elevated risk (RR: 1.89). These findings were almost unchanged after
adjustment for sleep duration and other confounders. Poor self-reported quality
of sleep seemed to be associated with an increased risk of mortality
independently of sleep duration.
PMID- 10778034
TI - Weight gain in adulthood and risk of developing glucose tolerance disturbance: a
study of a Japanese-Brazilian population. Japanese-Brazilian Diabetes Study
Group.
AB - We examined the data from 530 subjects enrolled in a survey on the prevalence of
diabetes in a Japanese-Brazilian population aged 40-79 years. Past self-reported
and current weight values were analysed. Student t test was used to compare
anthropometric measures between subjects with and without disturbance of glucose
tolerance (DGT), hypertension and dyslipidemia. Point and interval estimates of
the weight at 20 years-, age- and sex-adjusted odds ratios (OR) were obtained by
logistic regression analysis to evaluate the relationship between these diseases
and the percent weight gain. Subjects with DGT, hypertension or dyslipidemia
tended to have higher BMI during adulthood and to gain more weight in a shorter
interval of time. Also, they presented higher waist-to-hip ratio and plasma
glucose and worse lipid profile. OR were consistent with associations between
chronic diseases and percent weight gain. Trend test of OR indicated that the
risk of developing DGT alone or combined with hypertension and abdominal obesity
increased 2% and 15% by percent unit of gained weight, respectively, as compared
with those subjects with stable weight. Weight gain and the rate by which this
occurs during lifetime may confer increased risk of chronic diseases. We
suggested that preventive measures against obesity, i.e. the maintenance of
healthy body weight lifelong, are necessary to minimize the occurrence of these
diseases, also among migrant populations such as the Japanese-Brazilians.
PMID- 10778033
TI - Characteristics of receipt rate of financial aid for intractable disease patients
in Gifu Prefecture, Japan.
AB - The data on intractable disease patients who applied for official financial aid
for medical treatment in Gifu Prefecture, Japan, in fiscal year 1997 were
analyzed. In addition, to assess the nonapplied patients, a questionnaire on
intractable disease patients with disabilities needing assistance was sent to all
medical institutions in the prefecture. The results suggest that the low receipt
rate of financial aid in Gifu Prefecture results from both nonapplication by
patients and underdiagnosis at medical institutions. Percent completion of
medical treatment for intractable disease patients in a single secondary medical
service area was low. Although the percentage of patients with disabilities
authorized to receive financial aid was 4.6%, the estimated ratio of patients
with disabilities needing assistance exceeded this value. Therefore, the
dissemination of information on official services for patients and medical care
facilities must be strengthened.
PMID- 10778035
TI - Dietary patterns in a high-risk population for glucose intolerance. Japanese
Brazilian Diabetes Study Group.
AB - We evaluated dietary habits as risk factor for glucose intolerance in a high risk
population of Japanese-Brazilians enrolled in a study on the prevalence of
diabetes (DM). Based on oral glucose tolerance test and WHO criteria, 331 had
normal tolerance (NGT), 88 impaired tolerance (IGT) and 83 had type 2 DM (51 self
reported, 32 newly diagnosed diabetics). Clinical, laboratory and dietary data,
assessed by food frequency questionnaire (FFQ), were compared between the NGT
group and another composed of IGT and newly diagnosed DM (disturbed glucose
tolerance or DGT group). Associations of total energy intake and nutrient intakes
with glucose intolerance were analyzed by logistic regression. Also, subjects
with NGT and DGT entered into separate models of multiple linear regression
including BMI as the dependent variable, and total energy intake or each nutrient
as independent variables. DGT group showed higher waist-to-hip ratio, blood
pressure, plasma glucose and insulin levels and worse lipid profile. Total energy
intake, macronutrients, fibers, alcohol and saturated fat intakes did not differ
between groups; DGT was not associated with any nutrient intake in multivariate
analyses. BMI of the subjects with DGT but not with NGT was associated with
protein and cholesterol intakes in linear regression analysis. Our findings did
not support an association between nutritional factors and glucose intolerance
even in subjects who are unaware of their DGT, using FFQ to reflect current
habits. However, we suggest that protein and cholesterol intakes may be markers
of increased BMI. Despite assuming that obesity and insulin resistance precedes
DM, FFQ may not be useful in the assessment of unfavorable dietary patterns among
subjects at risk for glucose intolerance, such as Japanese-Brazilians with
elevated BMI.
PMID- 10778036
TI - Validity and reliability of the Japanese version of the selected anger expression
scale and age, sex, occupation and regional differences in anger expression among
Japanese.
AB - To examine the reliability and construct validity of the Japanese version of the
Anger Expression Scale among four Japanese communities, and to examine
distributions of anger expression scores according to sex, age, occupation, and
community, we performed a cross-sectional study among 1,802 men and 3,229 women
aged 20-70 in four geographic populations in 1995-97. We handed a self
administered questionnaire, which was selected from the Spielberger Anger
Expression Scale, to the participants in the risk factor surveys and measured
anger-in and anger-out as the anger expression scale. These scales had high
internal consistency (Cronbach's alpha coefficient was 0.97-0.98 for anger-out
and 0.77-0.86 for anger-in) and were of almost the same structure as the
original. The Pearson correlation coefficients for the anger expression scale
examined in 1995 and 1996 were 0.69 for anger-out and 0.57 for anger-in (both p <
0.001). The mean scores of both anger-out and anger-in were inversely associated
with age. The mean anger-out score was higher for men than for women (p < 0.001),
whereas the mean anger-in score did not vary significantly between the sexes.
Furthermore, the mean scores of anger-out and anger-in varied among populations
and occupational groups. The present study suggests that the Japanese version of
the selected Anger Expression Scale is an acceptable scale for evaluating anger
expression among Japanese.
PMID- 10778037
TI - Erythrocyte sedimentation rate in healthy school children of Bangladesh.
AB - The reference value of erythrocyte sedimentation rate (ESR) should be established
for a population concerned because it is influenced by many local conditions. It
has not yet been determined in healthy children of Bangladesh. This study was
done to determine the reference value of ESR in Bangladeshi children. ESR was
determined in a sample of 413 'healthy' primary school students (259 boys and 154
girls, mean age 8.7 years). Ninety-five percent of them had ESR < or = 30 mm
(Westergren 1 h). Our findings suggest that ESR value > 30 mm (Westergren 1 h)
should be considered high in Bangladeshi primary school children.
PMID- 10778038
TI - Comparison of isoflavones among dietary intake, plasma concentration and urinary
excretion for accurate estimation of phytoestrogen intake.
AB - Biological effects of dietary isoflavones, such as daidzein and genistein are of
interest in preventive medicine. We estimated the dietary intake of isoflavones
from dietary records and compared the values with the plasma concentrations and
urinary excretions in Japanese middle-aged women. The dietary intake of daidzein
and genistein was 64.6 and 111.6 mumol /day/capita (16.4 and 30.1 mg/day/capita),
respectively. The isoflavones intake was mostly attributable to tofu, natto and
miso. The median of plasma daidzein and genistein concentration was 72.46 and
206.09 nmol/L, respectively. The median of urinary excretion was 20.54 mumol /day
for daidzein, 10.79 for genistein, 15.74 for equol and 1.64 for O
desmethylangolensin (O-DMA). Equol and O-DMA were excreted by 50% and 84% of all
participants, respectively. Equol metabolizers were significantly lower the
plasma and urinary daidzein and urinary O-DMA. The dietary intake of daidzein and
genistein after the adjustment for total energy intake was significantly
correlated with the urinary excretion (r = 0.365 for daidzein and r = 0.346 for
genistein) and plasma concentration (r = 0.335 for daidzein and r = 0.429 for
genistein). The plasma concentration of isoflavones was also significantly
correlated with the urinary excretion. We conclude that in epidemiological
studies measurements of plasma concentration or urinary excretion of these
isoflavones are useful biomarkers of dietary intake and important for studies on
their relation to human health.
PMID- 10778039
TI - A managed care insurance product for the uninsured: a case study.
PMID- 10778040
TI - Exploring the role of religiosity in hypertension management among African
Americans.
AB - The role of religiosity in hypertension management among African Americans was
studied. Data were collected from in-depth, personal interviews with 20 African
Americans who had been diagnosed with hypertension for at least one year. A
majority of the participants used their religious beliefs as protective, control,
and coping mechanisms in the management of hypertension. Their personal religious
commitment enabled them to feel protected from immediate and long-term negative
consequences of hypertension, as well as find meaning in and exert control over
hypertension management. Furthermore, religious beliefs served to enhance their
ability to cope with having hypertension. These findings support the utility and
value of religiosity in the management of hypertension among African Americans.
Implications for hypertension management and educational interventions are
offered.
PMID- 10778041
TI - Barriers to health care for abused Latina and Asian immigrant women.
AB - This study identifies social, political, and cultural barriers to help seeking
from health care organizations faced by abused Latina and Asian immigrant women.
Qualitative data were collected through four semistructured ethnic-specific focus
group interviews with 28 abused Latina and Asian immigrant women. Participants
who had suffered intimate partner abuse were recruited through urban community
based organizations in San Francisco, California. Sociopolitical barriers to help
seeking and patient-provider communication included social isolation, language
barriers, and, for some, discrimination and fears of deportation. Sociocultural
barriers included dedication to the children and family unity, shame related to
the abuse, and the cultural stigma of divorce. Abused Latina and Asian immigrant
women face significant social, cultural, and political barriers to patient
provider communication and help seeking. Medical and social service providers and
policy makers may improve the quality of care for these women by understanding
and addressing these barriers.
PMID- 10778042
TI - Difficulty in reaching low-income women for screening mammography.
AB - Low-income women have a high mortality from breast cancer. Yet, they participate
in breast cancer early detection screening programs less than women in the
general population. An intervention study to improve screening mammography rates
of low-income women participating in Tennessee's TennCare program (state Medicaid
and Medicare program) revealed significant barriers to reaching these women.
Intervention methods included mail, telephone calls, and home visits. Results
indicate that only 38 percent of the women could be contacted for a baseline
survey. Reasons for noncontact included absence from home (39 percent), having
moved (22 percent), refusal to participate (17 percent), having no physical
domicile (15 percent), language barriers (4 percent), and miscellaneous other
factors (4 percent). Women with telephones tended to have a relatively higher
economic status and were more successfully reached than women without telephones.
These findings provide useful insights for future program planning and research
design.
PMID- 10778043
TI - Health status measurement performance and health status differences by age,
ethnicity, and gender: assessment in the medical outcomes study.
AB - The comparative measurement performance of self-reported health status
instruments for African American and Hispanic elderly has rarely been studied,
despite evidence of their poor health status. This study examined psychometric
performance and health status differences by age, ethnicity, and gender among
10,569 ethnically diverse patients who completed the Short-Form General Health
Survey in the Medical Outcomes Study (MOS). Hispanics and African Americans
tended to have slightly lower measurement performance than other ethnic groups.
Compared with whites, health status scores for African American and Hispanic
women were slightly but significantly lower. The small differences in health
status by ethnicity may be due to the MOS sampling strategy, which excluded low
socioeconomic status minorities with poor education and no regular medical care.
The psychometric performance of MOS health status measures should be examined in
studies of ethnically diverse, community-dwelling, elderly populations who have
poor access to care, poor education, and/or low socioeconomic status.
PMID- 10778044
TI - Determining needs and setting priorities for HIV-affected and HIV-infected
persons: northeast Ohio and San Diego.
AB - The Ryan White Comprehensive AIDS Resources Emergency (CARE) Act of 1991 requires
that communities receiving Title I funding engage in a needs assessment and
priority process to guide the allocation of those funds to various services
within the local community. This paper reports on the process and results of the
needs assessments in northeast Ohio and San Diego County for 1996-1997 and 1998.
Data from northeast Ohio's 1998 needs assessment indicated significant
differences between whites and nonwhites in the utilization of HIV specialist
care, HIV-related prescription medications such as antiretrovirals, and health
insurance. A need for additional dental care, complementary therapies, housing,
and assistance with utility payments was found in both geographic areas. Consumer
participation in San Diego's health department-based needs assessment process was
more extensive than in northeast Ohio's academic-based approach but was also
related to increased community-borne expense.
PMID- 10778045
TI - Frailty, family, and church support among urban African American elderly.
AB - A community-based survey of 507 African Americans aged 60 and older from South
Central Los Angeles was conducted to estimate the prevalence of frailty and
describe the correlation between frailty, social support from family and church,
and use of community services. Persons were considered frail if they met criteria
for any of four conditions: functional impairment, depression, urinary
incontinence, falls. Sixty-seven percent met criteria for frailty. Analyses
revealed that frail elderly were significantly less likely to report feeling very
close to family. Family contact, feeling that church was important, and receiving
church support were similar for the frail and nonfrail. Frail elderly were more
likely to use community services. These findings suggest that frail elderly in
this population may not receive more support from family and church than nonfrail
elderly. There is a need for caution when assuming families and churches in urban
African American communities are able to support the most vulnerable elderly.
PMID- 10778046
TI - The influences of race, ethnicity, and poverty on the mental health of children.
AB - Sufficient evidence demonstrates that poverty has a negative effect on the
psychological well-being of children, but most research has focused only on white
populations. The purpose of this literature review is to gain a better
understanding of the positive and negative influences of socioeconomic factors,
cultural/ethnic characteristics, and racial differences on the mental health of
children. A review of the literature on the influence of race, ethnicity, and
poverty on the mental health of children found that (1) children whose parents
are in poverty or who have experienced severe economic losses are more likely to
report or be reported to have higher rates of depression, anxiety, and antisocial
behaviors; and (2) after controlling for socioeconomic status, African Americans,
Native Americans, and Hispanics are less likely to report or be reported to have
such mental health problems. A theoretical construct for this protective effect
is related to cultural factors, such as perceived social support, deep
religiosity/spirituality, extended families, and maternal coping strategies as
buffers against psychological distress.
PMID- 10778047
TI - [Growth hormone (GH, hGH)].
PMID- 10778048
TI - [Growth hormone-releasing hormone (GHRH)].
PMID- 10778049
TI - [Somatostatin].
PMID- 10778050
TI - [Insulin like growth factor-I and II].
PMID- 10778051
TI - [Insulin-like growth factor binding protein-3 (IGFBP-3)].
PMID- 10778052
TI - [Growth hormone-binding protein].
PMID- 10778053
TI - [Luteinizing hormone (LH)].
PMID- 10778054
TI - [Follicle stimulating hormone (FSH)].
PMID- 10778055
TI - [Gonadotropin releasing hormone (GnRH)].
PMID- 10778056
TI - [Adrenocorticotropic hormone (ACTH)].
PMID- 10778057
TI - [Corticotropin-releasing hormone (CRH)].
PMID- 10778058
TI - [Lipotropins (LPH) and melanocyte-stimulating hormone (MSH)].
PMID- 10778059
TI - [Met5-enkephalin, Leu5-enkephalin].
PMID- 10778060
TI - [Beta-endorphin].
PMID- 10778061
TI - [Thyroid stimulating hormone (TSH)].
PMID- 10778062
TI - [Thyrotropin releasing hormone (TRH)].
PMID- 10778063
TI - [Prolactin (PRL)].
PMID- 10778064
TI - [Arginine vasopressin].
PMID- 10778065
TI - [Oxytocin (OT)].
PMID- 10778066
TI - [Neurophysin].
PMID- 10778067
TI - [Neurotensin].
PMID- 10778068
TI - [Total thyroxine (T4), free thyroxine (FT4)].
PMID- 10778069
TI - [Total triiodothyronine (T3), free triiodothyronine (FT3), reverse
triiodothyronine (rT3)].
PMID- 10778070
TI - [Monoiodothyronine and diiodothyronine].
PMID- 10778071
TI - [Thyroglobulin (Tg)].
PMID- 10778072
TI - [Thyroxine binding globulin (TBG)].
PMID- 10778073
TI - [Thyroxine binding capacity (TBC)].
PMID- 10778074
TI - [TSH receptor antibodies].
PMID- 10778075
TI - [Antithyroglobulin antibodies and antimicrosomal antibodies].
PMID- 10778076
TI - [Antithyroid peroxidase antibodies].
PMID- 10778077
TI - [Parathyroid hormone (PTH)].
PMID- 10778078
TI - [Parathyroid hormone-related protein (PTHrP)].
PMID- 10778079
TI - [Calcitonin (CT)].
PMID- 10778080
TI - [Calcitonin gene-related peptide (CGRP)].
PMID- 10778081
TI - [Serum cortisol, cortisone and free cortisol in urine].
PMID- 10778082
TI - [11-deoxycortisol and 21-deoxycortisol].
PMID- 10778083
TI - [18-hydroxycortisol, 18-oxocortisol, and 6 beta-hydroxycortisol].
PMID- 10778084
TI - [Corticosterone].
PMID- 10778085
TI - [11-deoxycorticosterone (DOC) and 18-OH-DOC].
PMID- 10778086
TI - [18-hydroxycorticosterone (18-OH-B)].
PMID- 10778087
TI - [Aldosterone].
PMID- 10778088
TI - [Dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S)].
PMID- 10778089
TI - [Pregnenolone, pregnenolone sulfate].
PMID- 10778090
TI - [17 alpha-Hydroxypregnenolone].
PMID- 10778091
TI - [17 alpha-Hydroxyprogesterone].
PMID- 10778092
TI - [Androstenedione].
PMID- 10778093
TI - [Androsterone].
PMID- 10778094
TI - [Etiocholanolone].
PMID- 10778095
TI - [Corticosteroid-binding globulin (CBG): measurement and its clinical
implication].
PMID- 10778096
TI - [11-hydroxycorticosteroid (11-OHCS)].
PMID- 10778097
TI - [17-hydroxycorticoids (17-OHCS) and its fractions].
PMID- 10778098
TI - [Urinary 17-ketosteroids (17-KS) and 17-KS fractions].
PMID- 10778099
TI - [Urinary 17-ketogenic steroids (17-KGS) and 17-KGS fractions].
PMID- 10778100
TI - [Urinary tetrahydro-11-deoxycortisol (THS)].
PMID- 10778101
TI - [Catecholamine].
PMID- 10778102
TI - [3,4-dihydroxyphenylalanine (DOPA)].
PMID- 10778103
TI - [Dopamine].
PMID- 10778104
TI - [Dopamine-beta-hydroxylase (DBH)].
PMID- 10778105
TI - [Metanephrine (M) and normetanephrine (NM)].
PMID- 10778106
TI - [Vanillylmandelic acid (VMA) and homovanillic acid (HVA)].
PMID- 10778107
TI - [3-methoxy-4-hydroxyphenylglycol (MHPG)].
PMID- 10778108
TI - [3,4-dihydroxyphenylacetic acid (DOPAC)].
PMID- 10778109
TI - [Chromogranin A, chromogranin B, chromogranin C].
PMID- 10778110
TI - [Serotonin (5-hydroxytriptamine; 5HT)].
PMID- 10778111
TI - [5-hydroxyindole acetic acid (5HIAA)].
PMID- 10778112
TI - [Neuropeptide Y].
PMID- 10778114
TI - [Catecholestrogen].
PMID- 10778113
TI - [Estrogen: estrone (E1), estradiol (E2), estriol (E3) and estetrol (4)].
PMID- 10778115
TI - [Progesterone].
PMID- 10778116
TI - [Pregnanediol (P2), pregnanetriol (P3)].
PMID- 10778117
TI - [Total testosterone, free testosterone].
PMID- 10778118
TI - [5 alpha-Dihydrotestosterone (DHT)].
PMID- 10778119
TI - [Androstanediol, androstanediol glucuronide].
PMID- 10778120
TI - [Sex hormone-binding globulin (SHBG)].
PMID- 10778121
TI - [Human chorionic gonadotropin (hCG) and subunits].
PMID- 10778122
TI - [Human placental lactogen (hPL)].
PMID- 10778123
TI - [Inhibin and activin].
PMID- 10778124
TI - [Insulin and abnormal insulin].
PMID- 10778125
TI - [Proinsulin].
PMID- 10778126
TI - [C-peptide (CPR)].
PMID- 10778127
TI - [Pancreatic glucagon].
PMID- 10778128
TI - [Enteroglucagon (EG)].
PMID- 10778129
TI - [GLP-1 (glucagon-like peptide 1)].
PMID- 10778130
TI - [Gastrin].
PMID- 10778131
TI - [Vasoactive intestinal polypeptide (VIP)].
PMID- 10778132
TI - [Cholecystokinin.pancreozymin (CCK-PZ)].
PMID- 10778133
TI - [Substance P].
PMID- 10778134
TI - [Secretin].
PMID- 10778135
TI - [Motilin].
PMID- 10778136
TI - [Human pancreatic polypeptide (hPP)].
PMID- 10778137
TI - [Pancreatic polypeptide (PP)].
PMID- 10778138
TI - [Gastric inhibitory polypeptide (GIP)].
PMID- 10778139
TI - [Insulin antibody].
PMID- 10778140
TI - [Anti-insulin receptor antibody].
PMID- 10778141
TI - [Islet cell antibody (ICA), islet cell surface antibody (ICSA)].
PMID- 10778142
TI - [GAD antibodies, GAD65 antibody].
PMID- 10778143
TI - [Plasma renin activity (PRA) and active renin concentration (ARC)].
PMID- 10778144
TI - [Angiotensin I, angiotensin II, angiotensin III].
PMID- 10778145
TI - [Erythropoietin].
PMID- 10778146
TI - [Kallikrein, kininogen and kinin in health and disease].
PMID- 10778147
TI - [Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type
natriuretic peptide (CNP)].
PMID- 10778148
TI - [Endothelin].
PMID- 10778149
TI - [Melatonin].
PMID- 10778150
TI - [Leptin].
PMID- 10778151
TI - [Cyclic AMP (cAMP)].
PMID- 10778152
TI - [Cyclic GMP (cGMP)].
PMID- 10778153
TI - [Thrombopoietin (TPO)].
PMID- 10778155
TI - [The integrin family].
PMID- 10778154
TI - [Immunoglobulin super family (ICAM, VCAM, NCAM)].
PMID- 10778156
TI - [Selectin family (E-selectin, P-selectin, L-selectin)].
PMID- 10778157
TI - [Cadherin].
PMID- 10778158
TI - [alpha-Fetoprotein (AFP)].
PMID- 10778159
TI - [Basic fetoprotein (BFP)].
PMID- 10778160
TI - [Carcinoembryonic antigen (CEA)].
PMID- 10778161
TI - [CEA (carcinoembryonic antigen) in nipple discharge].
PMID- 10778162
TI - [Pancreatic oncofetal antigen (POA), pancreatic cancer-associated antigen
(PCAA)].
PMID- 10778163
TI - [CA125].
PMID- 10778164
TI - [CA19-9].
PMID- 10778165
TI - [CA50].
PMID- 10778166
TI - [CA130].
PMID- 10778167
TI - [CA546, CA602].
PMID- 10778168
TI - [CA15-3].
PMID- 10778169
TI - [CYFRA21-1].
PMID- 10778170
TI - [Sialyl Tn antigen].
PMID- 10778171
TI - [2-->6 sialyl Lea antigen].
PMID- 10778172
TI - [BCA225].
PMID- 10778173
TI - [CA72-4 (TAG72)].
PMID- 10778174
TI - [Sialyl SSEA-1 (SLX)].
PMID- 10778175
TI - [NCC-ST-439].
PMID- 10778176
TI - [SCC antigen].
PMID- 10778177
TI - [DU-PAN-2, SPan-1].
PMID- 10778178
TI - [KMO1].
PMID- 10778179
TI - [Prostate-specific antigen (PSA) and PSA-ACT].
PMID- 10778180
TI - [Gamma-Sm].
PMID- 10778181
TI - [Prostatic acid phosphatase (PAP)].
PMID- 10778182
TI - [Tissue polypeptide antigen (TPA)].
PMID- 10778183
TI - [Immunosuppressive acidic protein (IAP)].
PMID- 10778184
TI - [PIVKA-II].
PMID- 10778185
TI - [Neuron specific enolase (NSE)].
PMID- 10778186
TI - [Elastase 1].
PMID- 10778187
TI - [5'-nucleotide phosphodiesterase isoenzyme-V (5'-NPD-V)].
PMID- 10778188
TI - [GAT (galactosyltransferase associated with tumor)].
PMID- 10778189
TI - [Small intestinal mucin antigen (SIMA)].
PMID- 10778190
TI - [Pregnancy specific beta 1 glycoprotein (SP-1)].
PMID- 10778191
TI - [Isoferritin].
PMID- 10778192
TI - [GSA-2-binding glycoprotein (GBG) and GSA-2-binding glycoprotein 2 (GBG2)].
PMID- 10778193
TI - [Pepsinogen I and II].
PMID- 10778194
TI - [Polyamine and ODC].
PMID- 10778195
TI - [Neopterin].
PMID- 10778196
TI - [Pro-gastrin-releasing peptide].
PMID- 10778197
TI - [Estrogen and progesterone receptors].
PMID- 10778198
TI - [Human chorionic gonadotropin beta-core fragment (hCG beta-cf)].
PMID- 10778199
TI - [Basic fibroblast growth factor in urine].
PMID- 10778200
TI - [Human urinary trypsin inhibitor].
PMID- 10778201
TI - [Free L-fucose (UFC) and sulfated bile acids in urine (U-SBA)].
PMID- 10778202
TI - [Urinary melanogen].
PMID- 10778203
TI - [Urinary BTA (bladder tumor antigen)].
PMID- 10778204
TI - [Urinary NMP22].
PMID- 10778205
TI - [Genetic testing as clinical tests].
PMID- 10778206
TI - [Introduction: maternal serum marker test for Down syndrome--present and
problems].
PMID- 10778207
TI - [The referral reasons of chromosome analysis and selection of samples].
PMID- 10778208
TI - [Method of chromosome analysis and karyotype description].
PMID- 10778209
TI - [Various methods of chromosome abnormality detection by DNA technology].
PMID- 10778210
TI - [Chromosome abnormalities and their clinical significance in leukemia and
lymphoma].
PMID- 10778211
TI - [Chromosome analysis of solid tumors using recent molecular-cytogenetic
techniques].
PMID- 10778212
TI - [Chromosomal analysis in congenital malformation syndromes].
PMID- 10778213
TI - [Indications of DNA diagnosis, clinical samples and storage].
PMID- 10778214
TI - [Genetic analysis--detection methods of genetic mutation].
PMID- 10778215
TI - [Methods of the detection for rearrangement of genes and its clinical relevancy].
PMID- 10778216
TI - [Significance of genetic diagnosis with oncogen and suppressor gene].
PMID- 10778217
TI - [DNA diagnosis of inborn errors of metabolism].
PMID- 10778218
TI - [Genetic analysis of malignant solid tumors].
PMID- 10778219
TI - [The genetic diagnosis of hematopoietic tumors].
PMID- 10778220
TI - [Gene diagnosis of hereditary hematological disorders].
PMID- 10778221
TI - [Molecular genetic diagnosis of muscle diseases].
PMID- 10778222
TI - [Genetic testing of triplet repeat disease].
PMID- 10778223
TI - [Genetics of neurologic disorders in children].
PMID- 10778224
TI - [Genetic diagnosis for the infectious diseases--a nonradioactive PCR-SSCP
technique].
PMID- 10778225
TI - [Genetic diagnosis of respiratory diseases].
PMID- 10778226
TI - [Molecular diagnosis of human gastrointestinal cancer].
PMID- 10778227
TI - [Hereditary assessment of cardiovascular disease].
PMID- 10778228
TI - [Genetic diagnosis of renal diseases].
PMID- 10778229
TI - [Molecular diagnosis of endocrine diseases].
PMID- 10778230
TI - [Gene mutation associated with diabetes mellitus].
PMID- 10778231
TI - [Genetic analysis of collagen diseases: rheumatic diseases].
PMID- 10778233
TI - [Nitric oxide and its related compounds].
PMID- 10778232
TI - [Analysis of atopic gene].
PMID- 10778235
TI - [NO3- in blood].
PMID- 10778234
TI - [Active oxygen].
PMID- 10778236
TI - [Allantoin].
PMID- 10778237
TI - [KL-6 antigen].
PMID- 10778238
TI - [Palmitoleic acid].
PMID- 10778239
TI - [Cholylglycine (CG)].
PMID- 10778240
TI - [Lysophospholipids].
PMID- 10778241
TI - [Serum nuclear matrix proteins (NMPs)].
PMID- 10778242
TI - Use of the MMPI-2's VRIN scale with severely disturbed populations: consistent
responding may be more problematic than inconsistent responding.
AB - The Minnesota Multiphasic Personality Inventory--Second Edition includes a new
validity scale, the VRIN scale, intended to detect random responding. High scores
are viewed as casting suspicion on the validity of the profile. For the present
study, the authors evaluated some of the complexities of the VRIN scale including
its interaction with the F scale. In particular, we tested two hypotheses. First
is that among psychotically disturbed test takers, some inconsistent responding
is an integral and expected mode of responding to a self-report measure. That is,
in an inpatient psychiatric population increased confused responding (high VRIN
score) is related in predictable ways to increased endorsement of psychotic
scales and two-point codes and to increased psychotic diagnoses. The second
hypothesis is a corollary--that the absence of inconsistency (low VRIN) in a
protocol indicating acute distress (high F) may indicate that a respondent is
being too consistent in presenting self as having severe difficulties. In this
case, the rest of the protocol may be an exaggerated description of the clinical
presentation. A sample of 521 psychiatric inpatients was used to evaluate these
hypotheses. Some support for both hypotheses is reported. Further studies are
recommended to evaluate the hypotheses.
PMID- 10778243
TI - Relationship between relaxation by guided imagery and performance of working
memory.
AB - This study tested the hypothesis that relaxation by guided imagery improves
working-memory performance of healthy participants. 30 volunteers (both sexes,
ages 17-56 years) were randomly assigned to one of three groups and administered
the WAIS-III Letter-Number Sequencing Test before and after 10-min. treatment
with guided imagery or popular music. The control group received no treatment.
Groups' test scores were not different before treatment. The mean increased after
relaxation by guided imagery but not after music or no treatment. This result
supports the hypothesis that working-memory scores on the test are enhanced by
guided imagery and implies that human information processing may be enhanced by
prior relaxation.
PMID- 10778244
TI - Program review of community residential care.
AB - This article provides an overview of the Department of Veterans Affairs Community
Residential Care Program and summarizes key literature about programs developed
in the United States. Descriptive data for 1995 and 1996 are provided to assist
program planners in comparing and contrasting client characteristics and
services. The authors conclude that, in addition to being cost effective, the
residential care program strengthens relationships between the health care
facility and the community it serves.
PMID- 10778245
TI - Vocational students' learning preferences: the interpretability of ipsative data.
AB - A number of researchers have argued that ipsative data are not suitable for
statistical procedures designed for normative data. Others have argued that the
interpretability of such analyses of ipsative data are little affected where the
number of variables and the sample size are sufficiently large. The research
reported here represents a factor analysis of the scores on the Canfield Learning
Styles Inventory for 1,252 students in vocational education. The results of the
factor analysis of these ipsative data were examined in a context of existing
theory and research on vocational students and lend support to the argument that
the factor analysis of ipsative data can provide sensibly interpretable results.
PMID- 10778247
TI - The role of aesthetic experience in changing selves.
AB - Some rapprochement between psychology and the arts may have therapeutic potential
as well as offer a basis for positive social interaction more generally. A simple
proposal is offered as a foundation.
PMID- 10778246
TI - Relationships between psychological variables relevant to asthma and patients'
quality of life.
AB - The relationships between health-related quality of life and various
psychological variables relevant to the clinical evolution of bronchial asthma
were evaluated for 101 asthma patients ages 14 to 72 years. Scores on quality of
life exhibited a significant negative correlation with perceived vulnerability,
panic-fear personality, and irritability, fatigue, airway obstruction,
hyperventilation, and panic-fear during attacks but was not significantly
correlated with preventive behaviour, attack-related behaviour, recognition, and
control of respiratory function, or quality of care. These results imply that the
effects of the former group of variables should be taken into account when
assessing asthmatic patients' quality of life.
PMID- 10778248
TI - Locus of control and attitudes toward large carnivores.
AB - It has been hypothesized tha the negative attitudes toward carnivores found among
rural groups is only one element embedded in a larger sociopolitical complex of
disputes over resource use and rural development. Negative attitudes may reflect
a protest against increased control of land use by central political authorities.
In a survey among sheep farmers, wildlife managers, and research biologists in
Norway we found that the sheep farmers expressed an external locus of control,
indicating a belief that external forces control events, relative to the two
other groups. Among sheep farmers and research biologists a positive association
was found between an external locus of control and negative attitudes toward
large carnivores.
PMID- 10778249
TI - Philosophy as a missing link between values and behavior.
AB - Despite the persistence of social scientists, evaluating the relationship between
values and behavior has not yielded clear results. Here, a model is proposed to
conceptualize and measure a person's operating philosophy. This assesses a
different level of the value structure within personality from separate values or
clusters of values; it is the evaluative structure within which a person's values
exist. Building on major philosophies, such as utilitarianism or humanism, the
model assumes that a person has a predominant Pragmatic, Intellectual, or Human
Operating Philosophy. In a sample of 801 subjects, each of these operating
philosophies had significant associations with a variety of the expected
behaviors evident in work and graduate school, such as initiative and empathy, as
well as learning styles, skills, and flexibility. Interpretation of the results
is offered as a way to understand the relationship between people's values or
beliefs and their behavior and approach to learning.
PMID- 10778250
TI - How popular is the Personality Assessment Inventory in practice and training?
AB - A review of recent survey data indicates that the Personality Assessment
Inventory ranks among the most frequently used objective personality tests in
practice and clinical training.
PMID- 10778251
TI - Moral reasoning, interpersonal skills, and cognition of rapists, child molesters,
and incest offenders.
AB - 54 inmates were subdivided into four groups and classified according to their
index offense. The groups included Rapists (n = 14), Incest Offenders (n = 9),
Child Molesters (n = 11), General Offenders (n = 20). Nonoffenders (n = 20) were
included as a control group. Psychometric tests including the Test of Nonverbal
Intelligence, the Defining Issues Test, Survey of Interpersonal Values, Porteus
Maze, and Minnesota Multiphasic Personality Inventory were administered to all
inmate and control groups. Analysis showed the rapists and child molesters scored
higher on moral reasoning on the Defining Issues Test; also rapists' scores were
more elevated on the Psychopathic Deviate and Paranoia scales of the Minnesota
Multiphasic Personality Inventory than those of other offender and control
groups. These results imply that rapists and child molesters have the ability to
understand moral issues; however, given their personality orientation, they
ignore these interpersonal social values.
PMID- 10778252
TI - Health of women: associations among life events, social support, and personality
for selected patient groups.
AB - This study examined the effects of life events, social support, personality
traits, and siblings' birth-order on the health of women. 199 middle-class
participants were included. 95 women, randomly assigned from four different
patient groups, were compared with a control group of 96 randomly selected women
without any special health problems. They completed a questionnaire which
included questions regarding family background, health, different life events,
social support, and signs of disease and a projective test, the Sivik
Psychosomatism Test. Analysis indicated that report of negative life events was
associated with more physical symptoms than positive life events and that the
patient groups reported more negative life events and less social support than
the control group.
PMID- 10778253
TI - Factor structure of the College Adjustment Scales.
AB - The present study examined the underlying structure of the College Adjustment
Scales via principal components analysis. A correlation matrix of the nine
subscales showed significant multicolinearity. A subsequent principal components
analysis demonstrated that one factor accounted for 57% of the total variance and
that the majority of subscales were moderately correlated with this single
factor. The results suggest that the College Adjustment Scales may measure the
same underlying construct and that the clinical distinctions implied by subscale
scores should be regarded with caution. Conclusions are constrained by sample
size and demographic characteristics, but the results suggest the need for
further empirical validation of the College Adjustment Scales, which may be
useful in college counseling centers.
PMID- 10778254
TI - Methodology in epidemiological studies of human neurobehavioral toxicity: a case
study with critical review.
AB - Health care professionals and government decision makers concerned with
neurotoxicity increasingly rely on neuropsychological research studies. An
example is an article relied upon by the U.S. Environmental Protection Agency
that reported effects on neurobehavioral performance in a group of factory
workers exposed to toluene by Foo, Jeyaratnam, and Koh in 1990, which is
described as lacking reliability and as having implausible contents. A critical
review can serve as an educational tool for neuropsychologists, to emphasize the
need to design and document their research and interpret findings without
speculation. For example, in the Foo, et al. study the implications of the
findings for the general population cannot be interpreted. To conclude that this
study has identified toluene as the cause of neurobehavioral deficits is a leap
of inference far exceeding the power in their study. The review underscores the
need for more critical reviews of research relied upon by decision makers and
researchers.
PMID- 10778255
TI - Students' perceptions of their self-regulatory and other-directed study
strategies: a factor analysis.
AB - Edited items on the 24-item Self-efficacy for Self-regulated Learning Scale were
combined with 7 items on external regulation developed in 1992 by Vermunt. The
inventory was administered to 244 entering freshmen enrolled in a university
orientation course. 19 students with incomplete responses were excluded from
analysis. Exploratory factor analysis with promax rotation indicated the five
factors of general organization and planning, external regulation, typical study
strategies, environmental restructuring, and recall. Coefficients alpha were .87,
.68, .74, .74, and .73, respectively.
PMID- 10778256
TI - Responses of seventh grade students to "do you have a partner with whom you would
like to have a baby?".
AB - This study investigated differences in demographic data, self-esteem, and coping
skills for 225 students in Grade 7 who reported having a partner with whom they
wanted to have a baby and 946 students who did not. Data were collected on the
Rosenberg Self-esteem Scale, the Family Crisis-oriented Personal Evaluation
Scale, and questions related to attitudes towards teen pregnancy and demographic
data. The sample included 548 (46.8%) boys and 624 (53.2%) girls whose mean age
was 13.2 yr. Students with a partner had significantly lower scores on the
curriculum questions, self-esteem, and family coping skills, combined with higher
scores in passivity. They indicated a desire to have a greater number of
children, beginning by having their first child at a younger age and believed
that having a baby improves a couple's relationship. Possible approaches may
include effective teaching methods to overcome passivity through boosting self
confidence, goal-setting, and acquiring a purpose in life besides parenting a
child.
PMID- 10778257
TI - A study of mood changes and personality during a 31-day period of chronic hypoxia
in a hypobaric chamber (Everest-Comex 97).
AB - High altitudes of more than 3,000 meters produce physiological disorders and
adverse changes in mood states. In the present study, we report analyses of mood
states and personality traits in eight experienced climbers participating in a 31
day period of confinement in hypobaric chamber and gradual decompression from sea
level to 8,848 m (Experiment 'Everest-Comex 97'). The subjects were tested at
5,500 m and 6,500 m on Day 13, 5,000 m and 6,500 m on Day 24, and 8,000 m and
8,848 m altitude on Days 27 and 31. Adverse changes in mood states, such as Vigor
and Fatigue, occurred at 8,000 m and 8,848 m, which were significantly correlated
with cerebral altitude symptomatology. In addition, a significant negative
correlation was found between Fatigue and Factor C, which is a personality
measure of emotional stability. We suggest that individuals with low emotional
stability could be more sensitive to environmental stressors than more
emotionally stable subjects who face reality.
PMID- 10778258
TI - Evaluation of a networked self-testing program.
AB - The use of a computerized, multiple-choice test bank to present practice and
assessment tests on a network was evaluated with 46 men and 119 women from a
first-year class in psychology. A correlation of .65 (p < .001) between scores on
a traditional paper-and-pencil test and scores on a computerized test provided
some validity for the computerized assessment. Regression analysis showed that
ability (previous academic performance) and motivation (number of practice tests
taken) accounted for 73% of the explained variance in computerized test scores.
Sex differences did not enter the regression equation significantly.
PMID- 10778259
TI - Sex differences in pain indices, exercise, and use of analgesics.
AB - To understand better reported sex differences in sensitivity to pain, this study
examined daily pain frequency and intensity, use of analgesics, physical
activity, and both subjective and physiological response to acute pain in 18 men
and 24 women, healthy people who provided information about their daily pain
symptoms and physical activity before completing a cold pressor task. Compared to
men, women reported more frequent and intense pain symptoms, as well as more
frequent use of analgesics and lower physical activity. Women evinced higher
physiological arousal during the cold pressor task but similar subjective pain.
The findings highlight the different ways men and women cope with pain and the
effect on their responses to acute pain.
PMID- 10778260
TI - Motivations for preventing versus assisting suicide.
AB - The motivations of those seeking to prevent and assist suicide are conceptualized
as defensive styles of repression versus sensitization adopted to deal with
personal suicidal desires.
PMID- 10778261
TI - Self-reflection and well-being: is there a healthy amount of introspection?
AB - Both extremely high and extremely low self-reflection have been considered as
risk factors for psychological maladjustment. Therefore, from an integrating
perspective medium amounts of self-reflection may constitute "healthy
introspection." To test this hypothesis, self-reflection and psychological well
being were measured with self-report tests given a pooled sample of 647 subjects.
A regressive relationship with self-reflection as a quadratic predictor of well
being was estimated using the LMS method for nonlinear structural equation
modeling. No evidence for a curvilinear effect was detected in the total sample
or in subgroups. Alternative theoretical assumptions are discussed on a
psychological and operational level.
PMID- 10778262
TI - Manic-depressive tendencies, suicidality, and perfectionism.
AB - In a sample of 82 college students, depression scores, but not manic scores, were
associated with both perfectionism and imposter scores.
PMID- 10778263
TI - Influence tactics used by subordinates: an empirical analysis of the Kipnis and
Schmidt Subscales.
AB - It was the purpose of this research to analyze the factorial and construct
validity of the Profile of Organizational Influence Strategies, Form M of Kipnis
and Schmidt, which assesses attempts to influence a manager and also attempts
when the manager has resisted doing what the employee wants. 254 German employees
from various organizations participated. The Profile of Organizational Influence
Strategies and the Blickle Inventory assessed upward influencing strategies over
2 wk. Data were analyzed with confirmatory factor analyses in a multitrait
multimethod design. All items loaded significantly on the expected factors. The
results support the factorial and convergent validity of the subscales. In
addition, the data show that initial attempts to influence and attempts after
resistance should be assessed separately.
PMID- 10778264
TI - Differentiating myoclonus from tics.
AB - A Myoclonus Versus Tic Checklist facilitates making this vexing differential
diagnosis. Although it appears to be a valuable tool for clinical, educational,
and research purposes, psychometric characterization of the Myoclonus Versus Tic
Checklist is needed.
PMID- 10778265
TI - Associations of symptoms of anxiety disorders and self-reported behavior problems
in normal children.
AB - 61 children, aged between 14 and 18 years, completed the Screen for Child Anxiety
Related Emotional Disorders, a scale of anxiety disorders symptoms, and the Youth
Self-report, a measure of internalizing, i.e., emotional, and externalizing,
i.e., behavioral, problems. Analysis showed that, with the exception of the
Social Phobia and the Specific Phobia subscales, Screen total and subscale scores
were significantly related to Internalizing problems (rs between .40 and .77).
Thus, the more frequently children reported Anxiety Disorder symptoms, the more
often they reported emotional problems. Furthermore, in particular, anxious
depressed problems as measured by the Youth Self-report were significantly
associated with scores on Screen scales. These results further support the
concurrent validity of the Screen.
PMID- 10778266
TI - Perceptions of insanity based on occupation of defendant and seriousness of
crime.
AB - The purpose was to estimate the relationship between a defendant's stated
intelligence on perceptions of his sanity and responsibility. This analog study
was a 2 (occupation of defendant) x 2 (seriousness of outcome) between-subjects
design. A scenario involving an insanity defense was read by 190 college students
who then answered a 12-item questionnaire. The hypothesis that participants would
attribute less responsibility to less intelligent defendants than to more
intelligent ones was partially supported. Belief in a Just World moderated these
evaluations. Seriousness of outcome influenced men's perceptions of the
defendant's insanity, responsibility, and sentence, but not women's. Participants
seemed to be more willing to accept the possibility that the defendant was insane
if the outcome of his crime was not serious.
PMID- 10778267
TI - Male entertainment award winners are older than female winners.
AB - It has been said that in the entertainment industry after a certain age women
have a harder time being as successful as men. Four analyses of the ages of male
and female Oscar winners, Oscar nominees, Emmy winners, and Grammy winners over
the past 25 years showed that in all four groups women were, on the average,
younger than the men. Two interpretations of these differences are delineated.
PMID- 10778268
TI - Dementia and mental retardation markers on the Rey 15-item Visual Memory Test.
AB - This study examined the qualitative errors of repetitions and confabulations on
the Rey 15-item Visual Memory Test among 500 psychiatric patients who were
divided into groups with (1) low IQ scores, (2) a diagnosis of dementia, and (3)
other psychiatric diagnoses. These groups were compared on the presence of
confabulated figures and repetitions on the Rey. The low IQ patients had the
highest rate for both confabulations (48.2%) and repetitions (43.6%). Demented
patients had the next highest rate of confabulations (39.8%) and repetitions
(39.8%). The general psychiatric patients had the lowest rates on confabulations
(16.2%) and repetitions (26.8%). Chi squared analysis showed that both
confabulations and repetitions significantly differentiated these patients of low
IQ and demented patients from general psychiatric patients. These results suggest
that clinicians who use the Rey 15-item Visual Memory Test and find either
confabulated or repeated figures should further explore the possibility that the
patient might have low intellectual functioning or dementia.
PMID- 10778269
TI - Strong commitment to traditional Protestant religious beliefs is negatively
related to beliefs in paranormal phenomena.
AB - Numerous studies have yielded small, negative correlations between measures of
paranormal and "traditional religious beliefs". This may partly reflect opinions
of Christians in the samples who take biblical sanctions against many
"paranormal" activities seriously. To test this, 391 college students (270 women
and 121 men) rated their beliefs in various paranormal phenomena and were
classified as Believers, Nominal Believers, and Nonbelievers on the strength of
their self-rated commitment to key biblical (particularly Protestant) doctrines.
As predicted, Believers were significantly less likely than Nominal Believers or
Nonbelievers to endorse reincarnation, contact with the dead, UFOs, telepathy,
prophecy, psychokinesis, or healing, while the beliefs of Nominal Believers were
similar to those of Nonbelievers. Substantial percentages of Nominal and
Nonbelievers (30-50%) indicated at least moderate acceptance of the paranormal
phenomena surveyed.
PMID- 10778270
TI - The role of police dogs as companions and working partners.
AB - Written responses to a questionnaire by 255 officers who used canines in police
work were assessed. Almost all officers frequently played with, talked to,
petted, and brushed their dogs and believed the dogs benefitted their health and
well-being. Officers whose dogs slept indoors, often in the same bedroom,
generally said they loved their dogs and they described their dogs as calm rather
than active, as indicated by a multiple correspondence analysis. These 96
officers more than the 154 officers whose dogs slept outdoors or in kennels also
planned to remain in canine work. Although departments often assumed
responsibility for purchasing the dogs, the more experienced officers usually
were involved in the final selection of dogs (logistic regression: p < .0001).
Compared with 94 officers not involved in selecting their dogs, 106 officers with
a specific role in selecting their dogs planned to stay in canine work, as shown
by a multiple correspondence analysis. They believed the dogs had saved their
lives (p < .01). Over-all, officers reported spending 4.1 hr. on-duty and 2.9 hr.
off-duty per week training their dogs, and also played with them for 6.5 hr. per
week, assuring a regular pattern of exercise for the officers. Virtually all
officers valued canine service and believed the dogs enhanced the department's
effectiveness. This study showed that both close companionship with the dog and
involvement in selecting the dog were associated both with satisfaction with the
dog and with working as a canine officer.
PMID- 10778271
TI - An examination of raters' and ratees' preferences in process and feedback in
performance appraisal.
AB - This paper examined the raters' and the ratees' preferences in Malaysia regarding
the performance appraisal process and feedback. A total of 52 managers (raters)
and 122 subordinates (ratees) participated. Analysis by t test and correlation
showed significant differences between raters and the ratees on most factors.
Ratees preferred to have more frequent appraisals than once a year and preferred
to have more frequent feedback from the managers about their performance. Ratees'
preference for the purpose of information on performance was towards salary
increase, promotion, training, and career development whereas the raters gave
more importance to training and career development.
PMID- 10778272
TI - Assessing attitudes toward gay marriage among selected Christian groups using the
lost-letter technique.
AB - 100 each envelopes were distributed to Christian church parking lots and general
public parking lots. Letters were addressed to either the "Gay Marriage
Foundation" or to a neutral organization. Significantly more neutral letters (n =
75) were returned than "Gay Marriage Foundation" letters (n = 36) from both types
of locations, but no differences were found for return rates. Gay marriage may be
a controversial topic for people in this area of California. The limitations of
the lost-letter technique prohibit fine distinctions; however, one may infer
attitudes toward gay marriage may not be more negative among Christian church
attendees than in the general public.
PMID- 10778273
TI - Workaholism and divorce.
AB - This study compared workaholism components and workaholic behaviors of managers
currently divorced or currently married. Data were collected using anonymous
questionnaires from 530 women and men. 44 divorced and 415 still-married managers
indicated similar workaholism and workaholic behaviors.
PMID- 10778274
TI - Levels of personal agency among academic majors.
AB - Action identification theory presented by Vallacher and Wegner characterizes
individual differences in identification level in terms of a personality
dimension known as "level of personal agency." Levels of personal agency, as
measured by the Behavior Identification Form, were examined in a sample of 237
college "seniors" representing eight academic majors. The mean levels of personal
agency among individuals in several of these majors were significantly different.
PMID- 10778275
TI - An outcome survey of psychology residency training program graduates of the
University of Texas Houston Medical School.
AB - A survey of 71 graduates of the psychology residency program at The University of
Texas Houston Medical School and the Texas Research Institute of Mental Science
indicated that two-thirds of the respondents were involved in private practice,
conducting primarily individual therapy, with assessment also playing a major
role in their practice. Managed care had the effect of placing limits on the
numbers of sessions available to patients, reducing income, and increasing
paperwork associated with practice. Implications for training during residency
are that individual therapy, using focused short-term approaches, and assessment
should continue to be the primary clinical experiences for trainees, and that
there should also be training in the business aspect of practice, including
marketing.
PMID- 10778276
TI - Human motor responses to simultaneous aversive stimulation and failure on a
valued task.
AB - The effects of presentation of an aversive stimulus and simultaneous failure on a
bogus intelligence test upon a subject's aggressive reactions were studied. The
subject's fist clenching was used as an indicator of aggression. Four conditions,
generated by the combinations of two kinds of stimulus delivered to the subjects
(aversive or nonaversive) and two outcomes of the task (failure or success), were
investigated. 20 female and 20 male students (ages: 17-34 years) were instructed,
upon the reception of an aversive or nonaversive acoustic signal, to press with
the right hand a device that displayed a slide. Each slide presented an item from
an intelligence test, to which the subjects were either allowed to answer
successfully (success) or not (failure). Failure increased the subject's
autonomic arousal, as measured by photoplethysmographic sensors, in all
stimulation conditions, but only the condition with aversive stimulation
increased the speed of clenching. This was interpreted as indicating subject's
tendencies to aggression. These results are discussed in relation to the effects
of frustration.
PMID- 10778277
TI - An examination of graduate students' statistical judgments: statistical and fuzzy
set approaches.
AB - The present study examined how statistical significance levels are treated and
interpreted by graduate students who use hypothesis-testing in their scientific
investigation. To test underlying psychological aspects of hypothesis-testing,
the idea of fuzzy set theory was employed to identify the uncertain points in
judgments. 34 graduate students in a psychology department made judgments about
hypothetical statistical decisions. The results indicated that (1) the majority
of these students treated significance levels on a continuum and rated them
according to the magnitude of statistical significance; (2) the subjects shifted
their decisions based on the types of hypothetical scenarios but not by the
sample sizes; instead, they interpreted a smaller sample size as being less
reliable. (3) The subjects frequently chose formally used statistical terms,
e.g., Significant and Not Significant, more than graduated verbal expressions,
e.g., Marginally Significant and Borderline Significant; and (4) the Fuzziness
(degree of confidence in decision-making) was dependent on individuals and
existed more in the critical points of transition where judgments are most
difficult. The Fuzziness Index illustrated the subtle shifts of human decision
making patterns in statistical judgments. Underlying decision uncertainties and
difficulties can be illustrated by functions generated from fuzzy set theory,
which may more closely resemble human psychological mechanism. This integrative
study of fuzzy set theory and behavioral measurements appears to provide a
technique that is more natural for examining and understanding imprecise
boundaries of human decisions.
PMID- 10778278
TI - Romantic acts and depression.
AB - The aim of the present study was to provide an examination of the relationship
between the importance individuals attach to romantic acts and depressive
symptoms. Among 140 male and 160 female English undergraduate students, the
importance individuals attach to romantic acts is significantly negatively
correlated with higher scores on the Beck Depression Inventory and the Depression
symptoms subscale of the General Health Questionnaire among the men only.
PMID- 10778279
TI - Assessing clinically significant change: application to the SCL-90-R.
AB - A Symptom Checklist (SCL-90-R) is a potentially useful measure of psychological
distress; it is frequently used in psychotherapy research and clinical practice.
The purpose of this study was to illustrate the use of the SCL-90-R for
determining statistically reliable change and clinical significance outlined by
Jacobson and Truax in 1991. This paper describes the concepts of statistical and
clinical significance of change. A proposal for obtaining and characterizing
samples is made. Then a clinician's perspective is taken. Reliable change
estimates and cut-off scores are chosen based on outcome data. Selected data from
a single psychotherapeutic process and outcome study then were used to test the
estimates of change and cut-off scores.
PMID- 10778280
TI - Personality and psychopathology of drug addicts in Puerto Rico.
AB - Drug abuse is one of the most pressing sociomedical problems of society. The
purpose of this study was to examine the personality and psychopathology of
addicts. 229 addicts in treatment programs scored high on Neuroticism and on the
Lie Scale and low on Psychoticism and Extraversion on the Eysenck Personality
Questionnaire for Puerto Rico. An Addiction Scale, based on a factor analysis,
showed a high component of Neuroticism items.
PMID- 10778281
TI - Care of elderly persons in the family: an approach based on a developmental
model.
AB - Care-giving as an act of decision-making, as a reciprocal action, and based on
sex of the care-giver, are reviewed. It is suggested that the care of elderly
parents, a long-term commitment, should be viewed from a developmental
perspective, beginning from childhood for an adult care-giver to be better
adjusted to this role and for better outcomes.
PMID- 10778282
TI - Using a small sample Q sort to identify item groups.
AB - A small sample of 40 second-year university students in Hong Kong were asked to
perform a Q sort on the 36 items of a questionnaire used to assess six dimensions
of student approaches to learning, the Learning Process Questionnaire.
Participants were instructed to sort the items into as many groups as they liked
with the only conditions being that all items within a group be as similar as
possible in perceived meaning and that no item be placed into more than one
group. By treating participants' responses as a form of multiple-choice data and
by applying optimal scaling, three solutions were obtained. A two-dimensional
plot of the optimal item scores for the first two solutions yielded 10 clearly
defined item clusters suggesting a possible ten-factor model as opposed to the
six-factor model found in studies of this questionnaire. The implications of
using this approach to identify potential competing factor models, especially
within a cross-cultural context, are discussed.
PMID- 10778283
TI - A field study of two measures of work motivation for predicting leader's
transformational behaviors.
AB - Relationships between motivation and transformational leadership were examined in
this study. 56 leaders and 234 followers from a variety of organizations were
sampled. Leaders were administered the Motivation Sources Inventory and the Job
Choice Decision-making Exercise, while followers reported leaders' behaviors
using the Multifactor Leadership Questionnaire (MLQ-rater version). Scores on the
Motivation Sources Inventory subscales subsequently correlated with the
Multifactor Leadership Questionnaire subscales of inspirational motivation,
idealized influence (behavior), and individualized consideration (range, r = .13
to .23). There were no significant correlations among any of the Job Choice
Decision-making Exercise subscales with any of the variables measured.
PMID- 10778284
TI - Internal consistency reliability and construct validity of the Dutch translation
of the Francis Scale of Attitude toward Christianity among adolescents.
AB - A sample of 1,021 young people attending Years 7, 8, 9, 10, and 11 at Catholic
secondary schools within the state-maintained sector completed the Dutch
translation of the Francis Scale of Attitude toward Christianity. The data
support its reliability and validity and commend it for further use in studies
conducted among young people in The Netherlands.
PMID- 10778285
TI - Descriptions of religious experience using trait and affect adjectives.
AB - 66 adults rated the relevance of adjectives representing dimensions of affect and
personality for describing how they felt during religious experiences.
Adjectives, representing positive affect (enthusiastic, at ease), low neuroticism
(calm, relaxed), and high agreeableness (soft-hearted, sympathetic),
conscientiousness (conscientious, reliable), and extraversion (sociable,
talkative), were rated to be descriptive of religious experiences. The failure of
openness to discriminate religious experiences is consistent with Block's
criticism (1995) of the five-factor model of personality.
PMID- 10778286
TI - FIRO-B: factors and facets.
AB - 10 FIRO-B intercorrelation matrices were factor analysed; one matrix was derived
from new FIRO-B data, all the other matrices were found in the literature. The
correlation matrices were also subjected to meta-analysis. The findings suggested
that the four FIRO-B scales associated with Inclusion and Affection are facets of
the ubiquitous interpersonal superfactor, Nurturance, but the two FIRO-B Control
scales each express an orthogonal construct both of which relate to the super
factor, Dominance.
PMID- 10778287
TI - Comparison of forced-choice and subjective probability scales measuring
behavioral intentions.
AB - Three surveys compared the accuracy of predictions based on forced-choice and
subjective probability scales. The latter produced significantly more accurate
election predictions and significantly reduced the percentage of undecided, or
"Don't Know" responses, compared to forced-choice scales in all three surveys.
Analysis indicates subjective probability scales decrease sampling error and
confirms there is an inherent source of error in traditional forced-choice
questions about voting intentions not attributable to sampling error. The results
are discussed with respect to (1) sampling and measurement errors in forced
choice and subjective probability scales measuring behavioral intentions, (2)
their practical application, and (3) cognitive theory, especially support theory.
PMID- 10778288
TI - Shyness in self-disclosure mediated by social skill.
AB - The purpose of this study was to examine the effect of Shyness and Social Skills
on Self-disclosure. Three scales, the Trait Shyness Scale, the Scale of Social
Skill, and the Self-disclosure Questionnaire were administered to 443 university
students. Scores on Shyness were highly negatively correlated with those on
Social Skills and moderately negatively correlated with Self-disclosure.
Furthermore, Self-disclosure scores correlated positively with Social Skills.
Separate factor analyses of the Shyness and Social Skills scales yielded four and
two factors, respectively. Findings suggest that shy people may have low
interpersonal skills and thus, they may hesitate to engage in self-disclosure.
PMID- 10778289
TI - Harris-Lingoes MMPI-2 Pd subscales and the assessment of law enforcement
candidates.
AB - This study analyzed the performance of 111 male law enforcement applicants on
MMPI-2 Harris-Lingoes Psychopathic Deviate (Pd) subscales. Applicants' self
descriptions derived from their scores on these subscales showed greater
confidence and resistance to authority and less social alienation and personal
unhappiness than the MMPI-2 national normative sample. A multiple regression
analysis indicated that Pd2 (Authority Problems) was the best predictor of K
corrected Pd scores for the sample of applicants.
PMID- 10778290
TI - Exposure to suggestion and creation of false auditory memories.
AB - The experiment investigated the possibility of creating false auditory memory
through exposure to suggestion. Research by Loftus and others has indicated that,
through suggestion, false memories can be created. Participants viewed a short
film and were given a 9-item questionnaire. Eight questions were used as filler
while one question asked respondents to recall a phrase one character had said.
Although the character actually said nothing, 23 of 30 respondents recalled
having heard him speak and specifically recalled his words. This statistically
significant result shows that auditory memories can also be created.
PMID- 10778291
TI - The Sexual Desire Inventory as a measure of sexual motivation in college
students.
AB - The human sexual response consists of at least two phases of behavior, the
motivational phase and the consummatory phase, which are difficult to isolate.
Sexual motivation questionnaires commonly contain items that assume sexual
intercourse or partners' experience and are often difficult to use with sexually
inexperienced persons. The Sexual Desire Inventory by Spector, Carey, and
Steinberg does not appear to be confounded with consummatory behavior. Our goal
was to check whether it can be used to measure sexual motivation. 40 men and 63
women completed the Sexual Experience Scale of sexual motivation by Frenken and
Vennix and the Sexual Desire Inventory. Scores on the two inventories were highly
correlated with this measure of sexual motivation and may be used with sexually
inexperienced individuals.
PMID- 10778292
TI - Security of medical information: the threat from within.
PMID- 10778293
TI - . . . and data for all: the NCI initiative on clinical infrastructure standards.
PMID- 10778294
TI - Biomedical computing: territorial expansion for informatics.
PMID- 10778295
TI - Positive outcomes, lower costs: using net-based IT to manage care.
PMID- 10778296
TI - Improving access to healthcare information: the Lister Hill National Center for
Biomedical Communications.
PMID- 10778298
TI - eHealthcareWorld. Changing the power structure of the industry.
PMID- 10778297
TI - Visual integration. A new technology for the thinking physician.
PMID- 10778299
TI - Wireless technology transforms healthcare delivery and tracking.
PMID- 10778300
TI - Births, marriages, divorces, and deaths: provisional data for March 1999.
PMID- 10778301
TI - PDA comments on draft guidance for industry, ANDAs: blend uniformity. Parenteral
Drug Association.
PMID- 10778302
TI - Validation of D value by different SCD culture medium manufacturer and/or
different SCD culture medium constituent.
AB - Variation in decimal reduction (D) time/value for attaining sterility assurance
was reported in terms of difference between lot to lot and/or manufacturer to
manufacturer of soybean casein digest (SCD) culture medium. The D value variation
phenomenon itself due to SCD culture medium was reported by Graham et al;
however, it was not sufficiently clarified what constituent(s) of SCD culture
medium would mainly contribute to the variation of D value. If it is not well
clarified, the reproducible sterility assurance cannot be successfully attained.
The authors studied individually the constituent of SCD broth (SCDB), SCD agar
(SCDA) and SCD broth plus 1.5% agar (SCDB/A). As a result, the culture medium
constituent causing D value variation among SCD culture medium was determined as
the difference of calcium (Ca) amount as well as the presence and the absence of
K2HPO4 in SCD culture medium. Additionally, it was clarified D value differed
significantly between SCDB and SCDA. D value using the former was around 1 min
lower than that using the latter. This phenomenon can be explained from the
formation of insoluble CaHPO4 in SCDB culture medium, resulting in insufficiency
of usable Ca to B. stearothermophilus in SCDB culture medium.
PMID- 10778303
TI - The influence of lyophilization on the polymorphic behavior of mannitol.
PMID- 10778304
TI - A note on concordance correlation coefficient.
AB - In this note, we first review some recent developments about measures of
agreement, which are often required in medicine and other sciences, with focus on
differences between these methods. In the last part, we mention five important
concerns when using a newly developed concordance correlation coefficient. Our
conclusion is that we need to be especially careful when using existing
correlation methods and a new correlation method needs to be developed in the
future.
PMID- 10778305
TI - Contamination control in HVAC systems for aseptic processing area. Part I: Case
study of the airflow velocity in a unidirectional airflow workstation with
computational fluid dynamics.
AB - A unidirectional airflow workstation for processing a sterile pharmaceutical
product is required to be "Grade A," according to EU-GMP and WHO-GMP. These
regulations have employed the wording of "laminar airflow" for unidirectional
airflow, with an unclear definition given. This seems to have allowed many
reports to describe discussion of airflow velocity only. The guidance values as
to the velocity are expressed in various words of 90 ft/min, 0.45 m/sec, 0.3
m/sec, +/- 20%, or "homogeneous air speed." It has been also little clarified how
variation in airflow velocity gives influences on contamination control of a
workstation working with varying key characteristics, such as ceiling height,
internal heat load, internal particle generation, etc. The present author has
revealed following points from a case study using Computational Fluid Dynamics:
the airflow characteristic in Grade A area shows no significant changes with
varying the velocity of supplied airflow, and the particles generated from the
operator will be exhausted outside Grade A area without contamination.
PMID- 10778306
TI - Parametric release--much ado about nothing.
PMID- 10778307
TI - Isolators and barrier devices in pharmaceutical manufacturing.
AB - The use of isolators and barrier technology in pharmaceutical manufacturing may
cause design problems, some of them unrecognised. These design problems are
highlighted in this paper and, where possible, solutions are given.
PMID- 10778308
TI - Applying a uniform layer of disinfectant by wiping.
AB - Disinfection or sterilization often requires applying a film of liquid to a
surface, frequently done by using a wiper as the applicator. The wiper must not
only hold a convenient amount of liquid, it must deposit it readily and
uniformly. Contact time is critical to disinfection efficacy. Evaporation can
limit the contact time. To lengthen the contact time, thickly applied layers are
generally preferred. The thickness of such layers can be determined by using dyes
or other tracers, as long as the tracers do not significantly affect the liquid's
surface tension and viscosity and thus do not affect the thickness of the applied
layer. Alternatively, as done here, the thickness of the layer can be inferred
from the weight loss of the wiper. Results are reported of experiments on
thickness of the layers applied under various conditions. Near saturation,
hydrophilic polyurethane foam wipers gave layers roughly 10 microns thick,
somewhat less than expected from hydrodynamic theory, but more than knitted
polyester or woven cotton. Wipers with large liquid holding capacity, refilled
often, should produce more nearly uniform layers. Higher pressures increase
saturation in the wiper, tending to thicken the layer, but higher pressures also
force liquid from the interface, tending to thin the layer, so the net result
could be thicker or thinner layers, and there is likely to be an optimal
pressure.
PMID- 10778309
TI - Steam sterilization and steam quality.
PMID- 10778310
TI - Sterilisation decision trees development and implementation.
PMID- 10778311
TI - [When should ruptured abdominal aneurysms be surgically treated?].
PMID- 10778312
TI - [Ultrasound contrast media].
PMID- 10778313
TI - [Bone lengthening. History of the development and field of applications].
AB - Leg lengthening has been performed since early in this century. The first
successful lengthening was reported in 1905. Leg lengthening evolved from forced
lengthening of the bone during anaesthesia, through use of cortical bone grafts,
plate and screws to callus distraction (callotasis). Development of external
fixators and evolution of biological concepts of bone regeneration has been
important. In 1951 Ilizarov developed his apparatus. Ilizarov pioneered the
biology of bone and soft-tissue regeneration. He performs a percutaneous
subperiosteal corticotomy and waits five to seven days prior to distraction with
a rate of 0.25 mm of length four times each day. The method has increased the
opportunities in reconstructive bone surgery. The technique is difficult with
many problems and obstacles which can be overcome.
PMID- 10778314
TI - [Surgery for ruptured abdominal aneurysm assisted by vascular unit team at the
primary receiving hospital].
AB - The objective of the study was to compare emergency operations for ruptured
abdominal aortic aneurysm (RAAA) by a mobile operation team, with operation for
RAAA carried out at our vascular unit. During a five year period (1993-1998), 18
emergency operations were carried out for abdominal aortic aneurysm (AAA) with
rupture at the primary receiving hospital with assistance from a mobile operation
team. In the same period 82 aneurysms with rupture were resected at our vascular
surgical unit. Preoperatively, patients operated at the primary receiving
hospitals had significantly lower blood pressure (P < 0.05) and an intraoperative
higher blood loss (P < 0.05). Furthermore, postoperative complications tended to
be higher among patients operated at hospitals without a vascular unit.
consequently, the mortality was 67% compared to 47% in the department. However,
1/3 of the patients operated by the mobile operation team survived. Consequently,
haemodynamically unstable non-transportable patients with an RAAA should be
considered for surgery by a mobile operation team.
PMID- 10778315
TI - [Recurrent familial intrahepatic cholestasis in the Faroe Islands].
AB - Recurrent familial intrahepatic cholestasis is an autosomal recessive disorder
characterized by episodes of severe pruritus and jaundice lasting for weeks to
months without extrahepatic bile duct obstruction. Symptom-free intervals may
last for months to years, and chronic liver damage does not develop. We recently
studied four of the five patients from the Faeroe Islands described by us 30
years ago (one had recently died), and a further five patients who were
identified after the initial report. The episodes of cholestasis were more
frequent and severe in patients with early onset, but tended to reduce in
frequency with age. The youngest patient, aged 25 years, who had had 16 episodes,
each lasting about six months, had a liver transplant after which no further
episodes were recorded (one year after surgery). Signs of chronic liver disease
were absent in all patients. The FIC1 gene was investigated for mutations in the
surviving patients. A single mutation (I661T) was found on both chromosomes in
all 9 patients, indicating that they are genetically identical for the disease
causing defect. Nevertheless, considerable differences between patients were
observed clinically.
PMID- 10778316
TI - [Injuries among 11-15 year old children].
AB - The objective is to describe the one year incidence rate of self-reported
injuries, their causes, where they happened, and their consequences within the
age group 11-15 years. Four thousand and forty-six students from a random sample
of 45 schools answered a standardized questionnaire about health and health
behaviour. This report regards injuries treated by a doctor or a nurse. During
one year, 28% were injured, 12% more than once; 12% needed medical treatment such
as a plaster cast, stitches, surgery or staying in a hospital; 16% missed at
least one full day in school. The injury incidence rate increases with age among
boys but not among girls. The proportion with more than one injury increases by
age among girls but not boys. The proportion who receive hospital treatment is
higher among boys than girls. The proportion who stay home from school because of
the injury increases with age among both girls and boys. Five percent are injured
at home, 5% at school, 9% are injured at a sport facility, and 4% in the
street/road. Ten percent report a sports injury, 4% an injury by falling, and 3%
by riding a bicycle. Most common injuries are sprain/strain/pull of a muscle
(9%), broken or dislocated bone (6%), and cuts (3%). In conclusion, the incidence
of self-reported injuries is much higher than the hospital-reported. More
research about injury-mechanisms and more preventive efforts are needed.
PMID- 10778317
TI - [Prophylactic contralateral orchiopexy in patients with testicular torsion].
AB - The aim of the study was to examine the recommendations for prophylactic
contralateral orchiopexy in patients presenting with unilateral testicular
torsion in Denmark. A questionnaire was mailed to the 61 surgical departments
treating acute urological patients. Prophylactic contralateral orchiopexy was
performed in 60 of the 61 departments. Twenty-eight departments routinely
performed a combined ipsilateral and contralateral operation. In 20 departments
the contralateral procedure was performed immediately in the case of a vital
ipsilateral testis, but delayed a median of five (3-12) weeks in the case of a
necrotic testis. In seven departments the contralateral orchiopexy was routinely
performed a median of 10 (2-12) weeks after the ipsilateral operation, and in the
remaining five departments the time of the contralateral procedure was determined
by the surgeon. In conclusion prophylactic contralateral orchiopexy was widely
used in patients with unilateral testicular torsion, but the timing of the
procedure varied.
PMID- 10778318
TI - [Acute hemolytic anemia caused by glucose-6-phosphate dehydrogenase deficiency].
AB - Glukose-6-phosphate dehydrogenase (G6PD) is essential in protecting the red cell
from oxidative damage. We report a case of acute haemolysis in a child with G6PD
deficiency. Because of the severity of the anaemia, the patient was treated with
blood transfusions and recovered fully. There are two main variants of G6PD
deficiency (the Mediterranean variant and variant A) with different clinical
profiles. Acute haemolytic attacks are induced by certain drugs, by infections
or, in the Mediterranean variant, by ingestion of fava beans (favism). Increased
awareness of this condition is necessary in Denmark because of increased
immigration.
PMID- 10778319
TI - [The UK Prospective Diabetes Study. Polypharmacy marching in?].
PMID- 10778320
TI - [Picture of the month. Rest tumors and metastases].
PMID- 10778321
TI - [Physicians and behavior of mass media--spying or attacking by the media?].
PMID- 10778322
TI - [Same day surgery--how far will we go?].
PMID- 10778323
TI - [Cochrane Colorectal Cancer Group--1998 activities].
PMID- 10778324
TI - [Somatoform disorders. What is wrong when there is "nothing" wrong?].
AB - Patients with somatoform and dissociative disorders complain of symptoms
suggesting physical disease. These patients are high utilizers of health services
but seldom receive relevant treatment. Recently empirical data have been obtained
concerning epidemiology, familiar distribution, and relation to personality in
these disorders. Somatoform patients often have comorbid depression and anxiety
disorder. These complications are often overlooked, but accessible to
psychopharmacological treatment. A number of psychotherapeutic techniques have
been developed for treatment in general practice and in hospital settings.
PMID- 10778325
TI - [Laparoscopic cholecystectomy as a same-day surgical procedure].
AB - The aim of this study was to describe the results of laparoscopic cholecystectomy
as an outpatient procedure in a prospective, consecutive, descriptive study. The
study included 50 patients selected in the period from April to December 1997,
who accepted the outpatient procedure. Preoperative complications, morbidity
during hospital stay, length of hospital stay, frequency of readmission and the
satisfaction of the patients were registered. In our investigation we found a
risk of preoperative complications of 6% (severe 0%), a morbidity during hospital
stay of 6% (severe 2%) and an incidence of readmission of 4%. A total of 74% of
the patient went home on the same day as the procedure, and 90% of all patients
had been discharged 24 hours later. The patients showed a high degree of
satisfaction. In conclusion laparoscopic cholecystectomy as an outpatient
procedure may be performed with a low risk of complications, a low incidence of
readmission, a high degree of satisfaction in patients, but with a high frequency
of primary admission (26%).
PMID- 10778326
TI - [Behavioral disorders in nursing home residents. 147 consecutive referrals to an
interdisciplinary team of consulting specialists].
AB - During a period of 22 months 147 consecutive residents with behavioural
disturbances from 80% of the Copenhagen nursing homes were referred to a visiting
team of consulting specialists. Each resident was evaluated clinically, and data
were recorded in a database. The conditions thought to represent the underlying
etiologies were dementia (79%), delirium (28%) and depression (35%). The most
commonly observed behavioural symptoms were aggressiveness, vocally disruptive
behavior and non-aggressive psychomotor symptoms. The most common interventions
suggested by the team were further diagnostic evaluations, adjustment of
pharmaceutical treatment, using the life history of the resident as a reference
for behaviour management, and psychological behavior management. There is a need
for increased focus on systematic diagnosis and treatment of behavioural
disorders, observed in nursing homes, which often have multifactorial etiology.
PMID- 10778327
TI - [Medical research and gender. An analysis of the preclinical departments at the
University of Copenhagen].
AB - The proportion of women among Danish medical graduates increased from 25% to 50%
in the years 1970 to 1996. The proportion of women among the medical scientific
staff has, however, not changed significantly over this period. At The University
of Copenhagen women comprised 16% of the preclinical faculty in 1970 and 21% in
1996, and today's lack of women cannot be explained as a legacy from previous
periods. The construction of a professional hierarchy is central in any
discussion of position and influence in scientific research. Women at the medical
faculties have in many respects a peripheral position. Relatively few have a
postgraduate medical degree, they are in general not employed in traditional
medical research areas such as physiology and anatomy, and there are
disproportionately fewer among the professors. The authors argue that the women's
position as non-doctors in low-status areas results in a lack of influence and
access to resources.
PMID- 10778328
TI - [Professional prestige and gender--clinical scientific staff in Copenhagen as an
example].
AB - At the clinical medical departments of The University of Copenhagen only 5% of
the clinical professors and 18% of the associate professors were women in 1995.
Among the other categories of the scientific staff, e.g. assistant professors,
34% were women. There was also an uneven distribution of women among the
specialties, ranging from 0% women on the scientific staff of the ear, nose and
throat specialty to 75% in geriatrics. Based on a ranking scale for the medical
specialties constructed by Album (9), the study shows that the percentage of
women within a specialty is negatively correlated to the prestige of the
specialty. On Album's scale ranging from 1 (highest) to 22 (lowest) the
specialties of the female professors had a mean ranking of 18.5 compared to 12.6
for the male professors. The mean ranking for the associate professors was 15.0
for the women compared to 8.8 for the men.
PMID- 10778329
TI - [Laparoscopic cholecystectomy as a same-day surgical procedures. Results and
patient satisfaction].
PMID- 10778330
TI - [Gastroscopic removal of penetrating gastric band].
AB - Gastric wall penetration of a gastric band after operation for morbid obesity is
a well known late complication. The treatment is usually reoperation. In this
case report we show that a band penetrating the gastric wall can be successfully
treated by gastroscopic operation. This technique is more simple than
reoperation, especially in case of morbid obesity at the time of the
complication.
PMID- 10778331
TI - [Human EGF receptor 2 and treatment of breast cancer].
PMID- 10778332
TI - [Treatment with iodine radioisotopes and thyroid-associated ophthalmopathy in
Graves' disease].
PMID- 10778334
TI - [Back pain].
PMID- 10778333
TI - [Picture of the month. Ventricular cancer].
PMID- 10778335
TI - [Is malabsorption the answer in connection with obesity?].
PMID- 10778336
TI - [Guidelines for measurement of TSH receptor antibodies in pregnant women. Results
from an evidence based symposium organized by the European Thyroid Society].
PMID- 10778337
TI - [Aerococcus urinae. A newcomer among pathogenic bacteria in clinical and
microbiological practice].
AB - A decade ago we discovered a hitherto unrecognized Aerococcus-like organism (ALO)
in urine specimens from patients with urinary tract infection. Further
microbiological and clinical investigations enabled us to classify it as a human
pathogen also causing urogenic septicaemia and endocarditis, the latter often
with lethal outcome. The organism is now designated Aerococcus urinae.
PMID- 10778339
TI - [Interobserver variation in the Red-Yellow-Black wound classification system].
AB - Communicating wound descriptions between disciplines for treatment and wound care
necessitates a simple and unequivocal classification system. The Red-Yellow-Black
(RYB) system has been suggested to comply with these demands. The reliability of
the RYB-system has, however only been investigated in small studies. The aim of
this study was to determine interobserver homogeneity (group Kappa a.m. Schouten)
of the RYB-system and further to examine whether interobserver homogeneity was
dependent on educational level. One-hundred-and-twenty photo-slides of non
healing ulcers of various etiologies were shown to 21 observers who recorded
their assessments in an entry form without discussing their assessments with the
other observers. Eighty-nine percent of the possible assessments were completed.
Observed agreement for all observers = 0.65; Kappa = 0.47. Kappa-coefficient in
subgroup of nurses = 0.49, subgroup of physicians with less than three years of
experience with wound treatment = 0.46 and for physicians with more than 10 years
of experience with wound healing = 0.48. In conclusion, we demonstrated moderate
interobserver agreement for using the RYB-characteristics. The RYB-system is
useful for communication about wound care and treatment. However, continuous
education and consensus meetings are advisable to increase agreement.
PMID- 10778338
TI - [Healing of venous leg ulcers. A randomized prospective study of a long-stretch
versus short-stretch compression bandage].
AB - The aim of the study was to compare the efficacy of two types of compression
bandage with different degrees of elasticity on healing of venous leg ulcers.
Forty-three patients with venous leg ulcers were included and blindly randomized
to treatment with one of the two types of bandage aiming at a sub-bandage
pressure in the ankle area of 40 mmHg. Forty legs were evaluated. Healed ulcers
after 12 months were observed in 71% of the long-stretch group and in 30% of the
short-stretch group (p = 0.06). Using life-table analysis the predicted healing
rate in the long-stretch group after 12 months was 81% and for the short-stretch
group 31% (p = 0.03). The mean of relative ulcer areas at 12 months was 0.25 for
the long-stretch group and 0.95 for the short-stretch group (p = 0.01). The
present study appears to indicate a positive influence of the elasticity of a
compression bandage applied with a sub-bandage pressure around 40 mmHg in the
ankle area on venous ulcer healing.
PMID- 10778340
TI - [Occurrence of carotid stenosis in patients with cerebrovascular symptoms].
AB - Stenosis of the internal carotid artery is a well known risk factor and is
estimated to be the cause of 20-30% of all strokes. As ultrasonography easily can
demonstrate arterial stenosis and causal surgical treatment is available we found
it of interest to investigate the occurrence of stenosis found among consecutive
non selected patients with focal neurological symptoms. Results of duplex
scanning from consecutive patients with various symptoms were collected.
Seventeen percent of the patients who had had transient ischaemic attacks were
found to have stenosis of 50% or greater. For the patients with persistent
central neurological symptoms (stroke) we found stenosis greater than 50% in 23%.
Only a few patients with uncharacteristic, non focal symptoms were found to have
stenoses. Carotid stenosis is found in approximately 20% of patients with focal
neurological symptoms. Hence ultrasound investigation is indicated for patients
suited for surgical treatment.
PMID- 10778341
TI - [Intravesical drug therapy in women with severe urge incontinence. Clinical
experiences from a department of gynecology].
AB - Conventional oral pharmacotherapy for urge incontinence remains problematic
because of limited efficacy and systemic side effects. In this study 27 patients
with severe urge incontinence were treated with intravesical drugs (emepron 200
mg or oxybutynin 5 mg) twice a day. They had previously on average undergone 3.3
other treatment options without satisfactory effect. The average age was 62
years, and their incontinence had on average lasted for 15 years. Seven percent
were cured and 41% were improved. Fifty-two percent had no satisfactory effect of
the treatment. The number of side effects was low, and none left the study for
this reason. Intravesical anticholinergic pharmacotherapy can be a treatment
option in women with severe urge incontinence.
PMID- 10778342
TI - [Complications after surgery for pilonidal cyst. An introduction to a new debate
on a "costly" disease].
AB - The frequency of wound complications following operation for pilonidal disease in
our department was compared with results from the literature. The case-records of
88 consecutive patients operated for 100 sinuses (12 recurrences), were evaluated
retrospectively, supplemented by a questionnaire. Wound healing problems occurred
in 69% of the sutured sinuses. Length of hospitalization was two days in
uncomplicated, five days in complicated, and eight days in open treated cases.
Convalescence (days off work) took 25 days, 41 days and 26 days, respectively.
There was no correlation between previous history of pilonidal disease, wound
healing complications, and outcome (recurrence frequency). Relapses occurred in
18%. In conclusion, the closure of pilonidal sinuses had a high frequency of
wound healing complications and recurrences.
PMID- 10778343
TI - [Eosinophilic cystitis in children].
AB - Eosinophilic cystitis is an inflammatory disorder of the urinary bladder,
characterised by irritative voiding symptoms, negative urine cultures, and
eosinophilic infiltration of the bladder wall. Since 1960 only about 20 cases
have been described in the English scientific reports, making it a rather rare
entity. In children the disease appears to be shortlived and self-limited,
requiring no specific treatment. We present a case with a 7.5-year-old boy, who
experienced spontaneous remission of all symptoms, following an acute attack of
eosinophilic cystitis.
PMID- 10778345
TI - [Language development in secretory otitis media].
PMID- 10778344
TI - [Acute pancreatitis in children caused by gallstones].
AB - A 10 year-old girl presented with acute abdominal pain. Serum-amylase was 3959
U/l. Ultrasonography showed dilatation of both the common bile duct and the
pancreatic duct and a high density area near the ampulla. Endoscopic retrograde
cholangiography (ERC) verified a stone near the ampulla, which was removed after
sphincterotomy. The girl recovered fully.
PMID- 10778346
TI - [A report on subarachnoid hemorrhage and intracranial aneurysm].
PMID- 10778347
TI - [Orlistat: medically induced malabsorption of the fat in the treatment of severe
obesity].
PMID- 10778348
TI - [In Process Citation]
PMID- 10778349
TI - [Declined semen quality?].
PMID- 10778350
TI - Shaken baby syndrome.
PMID- 10778351
TI - [Infertility due to azoospermia. Causes, examination methods and therapeutic
strategies].
AB - Azoospermia can be due to a genetic defect (abnormal karyotype, Y chromosome
micro-deletion or cystic fibroses carrier), genital tract infection or trauma.
Examination of azoospermic men includes ultrasound examination of the scrotal
contents, prostate and seminal vesicles, hormone analysis, genetic examinations
and testis biopsy. Some patients with obstructive azoospermia can be cured
surgically. If passage can not be established through the genital tract, sperm
can be obtained from the epididymis or testis for micro-insemination of oocytes
from the female partner. No increased occurrence of malformations among children
born after micro-insemination has been found, but an increased occurrence of
severe reduced semen quality may be expected, when the "ICSI boys" grow up.
Freezing of additional sperm or testis tissue is recommended.
PMID- 10778352
TI - [Assessment of nutritional risks among elderly hospitalized patients - which body
mass index and degree of weight loss should be considered?].
AB - The "Subjective Global Assessment", the "Nutrition Risk Score" and a Danish
counterpart are simple screening methods to detect patients at risk of nutrition
related complications. The cut-off points used in the screening are a body mass
index (BMI) less than 20 kg/m2 (or 18.5 kg/m2 in the Danish version) and weight
loss of more than 5% during the last month--regardless of age. This review of the
literature indicates that the optimal range of BMI for elderly people is
increasing from 18.7-25 kg/m2 to 24-29 kg/m2. It also suggests that a clinically
significant weight loss for the elderly is around 5% annually, less than in
younger age groups. Finally, there seems to be a high percentage of the old,
especially those initially malnourished, who will not benefit from nutritional
support. In conclusion, other cut-off points should be used for elderly (65+
years) patients, i.e. BMI less than 24 kg/m2 or any degree of weight loss.
PMID- 10778353
TI - [Pesticides and time to pregnancy among Danish farmers].
AB - The aim of this study was to examine time to pregnancy among farmers who used
pesticides (traditional farmers) and farmers who did not (organic farmers). A
total of 904 men, selected from the Danish Ministry of Agriculture lists of
traditional and organic farmers, participated in telephone interviews. The
participation rate was 84%. Information was collected on "time to pregnancy" for
the youngest child, exposure to pesticides and potential confounders. Using the
discrete analogue of the Cox Regression Model (including potential confounders:
male and female smoking, female age, parity and contraceptive method), the
fecundability ratio between traditional farmers using pesticides and organic
farmers was 1.03 (95% CI: 0.75-1.40). In the group of farmers who sprayed with
pesticides, none of the characteristics related to the use of pesticides could
account for the variation in time to pregnancy. No overall effect of pesticides
on male fecundability could be demonstrated in this retrospective study among
Danish farmers.
PMID- 10778354
TI - [Semen quality and fertility in a population-based follow-up study].
AB - Little is known about the importance of semen quality in male infertility. We
followed 430 first pregnancy planners with no previous reproductive experience
recruited among more than 50,000 cohabiting trade-union members. The couples were
consecutively enrolled into the study as they discontinued contraception and were
followed up for six month menstrual cycles or until a pregnancy was verified.
Each man provided a semen sample at enrollment. Women kept daily record of
vaginal bleeding and sexual activity. The probability of conception increased
with increasing sperm concentration up to 40 x 10(6)/ml, but any higher sperm
density was not associated with additional likelihood of pregnancy. The
proportion of sperm with normal morphology was strongly related to likelihood of
pregnancy, independently of sperm concentration. In conclusion, sperm
concentration and morphology are valuable biological markers of male fecundity.
Reference values for semen quality based on biological knowledge can be
established.
PMID- 10778355
TI - [Occurrence of testicular cancer in subfertile men. A case-control study].
AB - In order to evaluate the association between male subfertility and the subsequent
risk of testicular cancer, a population-based case-control study was conducted in
The Danish population. Cases were identified in the Danish Cancer Registry;
controls were randomly selected from the Danish population using the computerized
Danish Central Population Register. The men were interviewed by telephone; 514
cases and 720 controls participated. A reduced risk of testicular cancer was
associated with paternity (relative risk = 0.63; 95% confidence interval: 0.47
0.85). In men who prior to the diagnosis of testicular cancer had a lower number
of children than expected on the basis of their age, the relative risk was 1.98
(95% confidence interval: 1.43-2.75). There was no corresponding protective
effect associated with a higher number of children than expected. The
associations were similar for seminoma and non-seminoma, and were not influenced
by adjustment for potential confounding factors. These data are consistent with
the hypothesis that male subfertility and testicular cancer share important
aetiological factors.
PMID- 10778356
TI - [Topical steroids in the treatment of phimosis in children].
AB - The aim of this study was to evaluate the efficacy of steroid application in the
treatment of childhood phimosis. In a consecutive study 91 boys were treated with
application of topical betamethason 0.05% cream twice daily. The foreskin was
treated for one month, with an attempt at foreskin retraction after fourteen
days. Treatment was controlled after one month and six months. Sixty boys
achieved full retraction of the foreskin and nine had partial retraction and
relief of symptoms. Twenty-two boys had unsatisfactory response and had an
operation. Forty-five boys were controlled after six months, 13 had recurrence,
of these nine were satisfied and free of symptoms, two had a new steroid
treatment with full success, and two wanted a circumcision. A total of 74% did
not need an operation after topical steroid treatment. No side-effects or
complications were registered. Childhood phimosis can be successfully treated
with steroid application, and the treatment should be offered prior to an
operation.
PMID- 10778357
TI - [Hearing tests in a specialized practice].
AB - The purpose of the study was to evaluate the quality of examinations performed in
ENT-practice as preparation for hearing aid (HA) fitting. The material comprises
113 referrals to an audiological department from the Eastern Danish area
including an audiogram. The referrals were evaluated concerning information
relevant for HA fitting. A comparison between the pure tone air conduction
hearing thresholds measured in the ENT-practice and in the audiological
department was also performed. Only one referral contained information about all
relevant examinations. Pure tone air conduction thresholds measured in ENT
practice deviated significantly at 250 Hz-4 kHz from the hearing thresholds
measured in the audiological department, and indicated poorer hearing at all
frequencies. Only 53% of the air conduction hearing thresholds evaluated for the
average of 0.5-4 kHz corresponded with the thresholds measured in the
audiological department within the repeatability of the test (i.e. +/- 10 dB). In
conclusion, the audiometries in the referrals should only be considered as
screening.
PMID- 10778358
TI - [Respiratory depression following medication change from tramadol to morphine].
AB - Respiratory depression following change of medication from tramadol to morphine
is described in two patients. Tramadol is metabolized by cytochromoxidase CYP2D6
to O-desmethyl-tramadol with opioid agonist activity. Of the western population
7% have a mutation of the gene responsible for CYP2D6, resulting in low enzyme
activity. These persons will have little effect of tramadol. When tailoring
analgesia, the lack of response to tramadol may be interpreted as a need for
opioid dose increase. In such cases, excessive opioid doses may be prescribed
resulting in opioid side effects.
PMID- 10778359
TI - [Thrombocytopenia caused by Parvovirus B19 infection in a child with acute
lymphatic leukemia].
AB - A three-year-old boy was diagnosed with acute lymphoblastic leukemia. Two years
later, while on maintenance chemotherapy, the patient was readmitted due to
thrombocytopenia. The thrombocytopenia was caused by parvovirus B19 infection as
evidenced by the finding of specific DNA in serum and bone marrow samples.
Previous reports have highlighted the role of parvovirus B19 as a haematological
pitfall and the present case shows that this virus has the potential to mimic a
leukemic relapse.
PMID- 10778360
TI - [The Danish Infertility Cohort--a research database].
PMID- 10778361
TI - The genetically modified food fight.
PMID- 10778362
TI - Providing universal coverage under national health insurance.
PMID- 10778363
TI - Why health care is failing in a booming economy.
PMID- 10778364
TI - Utilitarianism and the perversion of the ethics of hippocrates.
PMID- 10778365
TI - Beware of bosses bearing beverages.
PMID- 10778366
TI - A baby with pink cheeks.
PMID- 10778367
TI - Biotechnology company claims to have 97% of human genes on its database.
PMID- 10778368
TI - Breast cancer researcher accused of serious scientific misconduct.
PMID- 10778369
TI - Guidelines for advertising on health web sites: who's guarding the Koop.
PMID- 10778370
TI - Growing pains of the Internet age.
PMID- 10778371
TI - Oregon's suicide video.
PMID- 10778372
TI - Outbreak of boils in an Alaskan village: a case-control study.
AB - OBJECTIVE: To determine whether taking steam baths was associated with
furunculosis and to evaluate possible risk factors for the occurrence of boils
during a large outbreak in Alaska. DESIGN: A cohort study of village residents, a
case-control study, and assessment of environmental cultures taken from steam
baths. SETTING: Village in southwestern Alaska. PARTICIPANTS: 1 adult member from
77 of the 92 households in the village was interviewed; 115 residents with at
least one boil occurring between January 1 and December 12, 1996 were considered
to be cases; 209 residents without a boil acted as the control group. All 459
village residents were included in the cohort study. MAIN OUTCOME MEASURE: Rate
of infection among all residents and residents who regularly took steam baths,
risk factors for infection, and relative risk of infection. RESULTS: 115 people
(25%) had had at least one boil. Men were more likely to have had a boil than
women (relative risk 1.5; 95% confidence interval 1.1 to 2.2). The highest rate
of infection was among people ages 25-34 years (32/76; 42%). No children younger
than 2 years had had boils. Boils were associated with using a steam bath (odds
ratio 8.1; 3.3 to 20.1). Among those who used a steam bath, the likelihood of
developing boils was reduced by routinely sitting on a towel while bathing, which
women were more likely to do, and bathing with fewer than 8 people. Of the 93
samples taken from steam baths, one Staphylococcus aureus isolate was obtained
from a bench in an outer dressing room. CONCLUSION: Using a steam bath was
associated with developing boils in this outbreak in a village in Alaska. People
should be advised to sit on towels while using steam baths.
PMID- 10778373
TI - Using towels and soap in steam baths could reduce infection.
PMID- 10778374
TI - Active management of labor: a cost analysis of a randomized controlled trial.
AB - OBJECTIVE: To compare the costs of a protocol of active management of labor with
those of traditional labor management. DESIGN: Cost analysis of a randomized
controlled trial. METHODS: From August 1992 to April 1996, we randomly allocated
405 women whose infants were delivered at the University of New Mexico Health
Sciences Center, Albuquerque, to an active management of labor protocol that had
substantially reduced the duration of labor or a control protocol. We calculated
the average cost for each delivery, using both actual costs and charges. RESULTS:
The average cost for women assigned to the active management protocol was
$2,480.79 compared with an average cost of $2,528.61 for women in the control
group (P = 0.55). For women whose infant was delivered by cesarean section, the
average cost was $4,771.54 for active management of labor and $4,468.89 for the
control protocol (P = 0.16). Spontaneous vaginal deliveries cost an average of
$27.00 more for actively managed patients compared with the cost for the control
protocol. CONCLUSIONS: The reduced duration of labor by active management did not
translate into significant cost savings. Overall, an average cost saving of only
$47.91, or 2%, was achieved for labors that were actively managed. This reduction
in cost was due to a decrease in the rate of cesarean sections in women whose
labor was actively managed and not to a decreased duration of labor.
PMID- 10778375
TI - The active management of labor: is it worth the cost?
PMID- 10778376
TI - Poor-quality studies suggest that vitamin B6 use is beneficial in premenstrual
syndrome.
PMID- 10778377
TI - A psychoeducational program increased knowledge and decreased sexual risk
behaviors in young adults with genital herpes.
PMID- 10778378
TI - A low dose of albuterol by metered-dose inhaler with a spacer was as effective as
higher doses by metered-dose inhaler or low doses by nebulizer in children with
mild acute asthma.
PMID- 10778379
TI - Severe neutropenia: a diagnostic approach.
PMID- 10778380
TI - How molecular epidemiology has changed what we know about tuberculosis.
PMID- 10778381
TI - How to treat influenza and colds.
PMID- 10778382
TI - Can exercise-induced muscle damage be avoided?
PMID- 10778383
TI - Anatomy of a medical accident.
PMID- 10778384
TI - An honest mistake, within the standard of care, will not result in a finding of
liability.
PMID- 10778385
TI - Placebo-controlled trials: good science or medical neglect?
PMID- 10778386
TI - Medical practice 2010: how we get there.
PMID- 10778387
TI - The biosphere theory of V. I. Vernadsky and the Gaia theory of James Lovelock: a
comparative analysis of the two theories and traditions.
AB - James Hutton (1726-1797) regarded Earth as a super-organism and physiology the
science to study it. A strong line of evidence for an intimate relationship of
biological and abiotic processes on Earth leads from Hutton to the Gaia theory of
J. Lovelock. A less known in the West but important approach to the biosphere as
a self-regulating system (the biosphere theory) was proposed V.I. Vernadsky (1863
1945). The main concern of this paper revolves around the question: What is the
difference between Gaia and the biosphere? To approach the problem of Earth as a
super-organism one can use also the biosphere theory of V. N. Beklemishev (1890
1962), who examined the biosphere from a morphological viewpoint.
PMID- 10778388
TI - [The mathematical modelling of population dynamics taking into account the
adaptive behavior of individuals].
AB - The general approach for modelling of abundance dynamic of biological populations
and communities is offered. The mechanisms of individual adaptation in changing
environment are considered. The approach is detailed for population models
without structure and with age structure. The property of solutions are
investigated. As examples the author studies the concrete definitions of general
models by analogy with models of Ricker and May. Theoretical analysis and
calculations shows that survival of model population in extreme situation
increases if adaptive behaviour is taking into account.
PMID- 10778389
TI - Identification of highly conserved hydrophobic amino acid motif in deduced amino
acid sequence of Elymus sibiricus L. mitochondrial S13 ribosomal protein.
AB - The nucleotide sequence of mitochondrial ribosomal protein rps13 gene from wild
perennial grass Elymus sibiricus is presented. It was determined by the method of
PCR amplification with specific oligonucleotide primers and the direct sequencing
of the amplification product. The sequence of E. sibiricus mitochondrial gene for
S13 predicts a hydrophobic ribosomal protein of 116 amino acids that shows strong
similarity to those of wheat (99.7% identity) and maize (98%). The deduced amino
acid sequence of S13 protein from E. sibiricus and homologous plant's (Zea mays,
Daucus carota, Nicotiana tabacum, Marchantia polymorpha) and nonplant's
(Escherichia coli) proteins shows the presence of hydrophobic amino acids' motif
L-X10-L-X10-M-X10-L-X10-L-. Slightly modified it can be found in many other
ribosomal proteins. This conserved motif is presumed to be particularly important
for association of the ribosomal S13 protein with other proteins in the small
subunit of the mitochondrial ribosome.
PMID- 10778390
TI - [The calcium and magnesium ion metabolic characteristics of water plants in
different taxonomic groups].
AB - Ca2+ and Mg2+ metabolism was investigated in 7 angiosperms and 3 moss species
from fresh water of different mineral content. It is considered that adaptation
in the water with low mineral content is connected with the decrease in salt
wastes of an organism. The adaptation of ion-transport system of aquatic plants
to living under conditions of low mineralization is higher in mosses than in
angiosperms. Characteristics of mosses are very low speed of salt waste in
distillate water (V0) and concentration of balance (Cb). According to suitability
of ion metabolism system to the existence in water with low mineralization
angiosperms could be divided into three groups. Some species are close to mosses,
but the majority of plants are adopted to the water with medium or high
mineralization. The difference in ion metabolism is connected with the conditions
of origin of the given groups. The authors consider that effective adaptations
were formed in the ancestor group of this taxon.
PMID- 10778391
TI - [The input of the chemical potential gradient of the water in the medium to the
energy balance of terrestrial vascular plants].
AB - One of the characteristic feature of activity of plant organism vital functions
is a speed of its inner water flow. The main source of energy providing the
transport of water is gradient of water chemical potential between soil and
atmosphere. In case of equal potentials of these surroundings, the plant organism
have additional energetic expenses to compensate the energy of external source.
Series of experiments to investigate the influence of saturation of atmosphere
with water (equilibrium of potentials) to energetic balance of plant were carried
out. The results shows that: 1) etiolate seedlings in this conditions waste 10-15
percent energy per unit of new formation more than under 70-80 percent humidity;
2) saturation of atmosphere with water above plants with well developed
transpiration surface leads to the decrease in their heat content; 3) equilibrium
of water chemical potentials of different environments increases the intensity of
intact root transpiration, i.e. intensifies "the burning" of organic matter.
Thus, gradient of water chemical potential existing in nature between
environments of different organs if sufficient source of energy for a plant.
PMID- 10778392
TI - [The mechanisms of the restriction of pollinator range in the fireweed
(Chamaenerion angustifolium) and 2 species of geranium (Geranium palustre) and G.
pratense)].
AB - Flowers of Chamaenerion angustifolium, Geranium palustre and G. pratense are
visited by more than 100 insect species. For all plants the spectrum of visitors
is similar. However the role of insects species in pollination is different and
depends on the stamen and stigma length, flexibility of pedicle and feeding
behaviour of insect inside flower. The possibility to take and to transport
pollen grains usually increase with the size of insect. The nature of this
correlation is determined by stamen and stigma length. Pollinators of G. palustre
with short stamens and stigmas are smaller than those of Ch. angustifolium and G.
pratense. On the other hand, more flexible pedicle of G. palustre prevent the
flowers from visits of big insects. Three plants studied by the authors are not
equally attractive for different insect groups. Dense in fluorescence of Ch.
angustifolium and G. pratense that usually are lifter under the grass are very
attractive for foraging social insects (honey bee, bumblebee). Flies avoid long
distance travelling and prefer single flowers located not far from each other.
For instance G. palustre is more attractive for flies not for social bees. It is
pollinated mainly by flies and solitary bees with average weight of 10-70 mg. The
main pollinators of Ch. angustifolium and G. pratense are honey bees, bumblebees
and wasps with average mass exceeding 70 mg.
PMID- 10778393
TI - [The sensitivity of the moor frog Rana arvalis Nilss. tadpoles to natural L-amino
acids and its alteration in ontogeny].
AB - The Rana arvalis tadpoles at 27-40 stages responded to solution of some L-amino
acids in concentration 10(-2) mol/l with feeding reactions. The range of
perceptible amino acids increased during development from 10 to 16. The best
feeding stimuli were aspartic and glutamic acids; amino-acids (proline and
oxyproline), methionine, leucine and isoleucine did not evoke the significant
reactions. The sensitivity to some amino acids (alanine, glutamine, lysine,
ornithine, proline and valine) was 10(-5)-10(-4) mol/l at earlier stages and
increased to 10(-6)-10(-5) mol/l during larval ontogenesis.
PMID- 10778394
TI - [The migrations of the green oak tortrix Tortrix viridana L. (Lepidoptera,
Torticidae): an analytical study].
AB - The author analyses mono-factorial theories of population dynamics of Tortrix
viridana and discusses the hypothesis of its distant and attended migrations
together with its specialized parasitoid Dirophanes invisor. Data on T. viridana
temporal-spatial distribution for the period of 1938-1995 are presented. It was
shown that the main factors caused the decrease in population numbers are intra
population mechanisms, providing the initiation long embryonic diapause for some
part of population, the decrease in the frequency of its outbreaks. Some data
indicate that large scale migrations are not important for spreading of T.
viridana outbreaks.
PMID- 10778396
TI - [Laser revascularization--a questionable method without revascularization].
PMID- 10778395
TI - Lung volume reduction surgery.
PMID- 10778397
TI - ["The best prescription may be no prescription"].
PMID- 10778398
TI - [Percutaneous myocardial laser revascularization. A new therapy technique for
patients with coronary disease and severe angina pectoris without conventional
therapy options].
AB - BACKGROUND AND OBJECTIVES: In patients with intractable angina because of end
stage coronary artery disease, transmyocardial laser revascularization (TMR)
leads to improvement of angina pectoris and increased exercise capacity. However,
surgical thoracotomy is required for TMR with considerable morbidity and
mortality. Therefore, a catheter-based laser system has been developed which
allows to create laser channels into the myocardium from the left ventricular
cavity. PATIENTS AND METHODS: 46 patients (38 m, 8 f) with refractory angina
pectoris due to severe coronary artery disease were treated with "percutaneous
myocardial laser revascularisation" (PMR). Clinical parameters (severity of
angina pectoris, use of additional nitroglycerin) and results of non-invasive
tests (exercise-ECG, echocardiography, thallium-scintigraphy) were analysed at
baseline and 3, 6 and 12 months after PMR. RESULTS: The PMR procedure was
successfully completed in all patients. In 30 patients, one region (anterior,
lateral, inferior) of the left ventricle was treated and in 16 patients, 2 or 3
regions were treated. Clinical follow-up demonstrated significant improvement of
angina pectoris (CCS-class at baseline: 3.1 +/- 0.2, 3 months after PMR: 1.8 +/-
0.7, 12 months after PMR: 1.5 +/- 0.9) (p < 0.001) and increased exercise
capacity (exercise time on standard bicycle ergometry at baseline: 383 +/- 151 s,
3 months after PMR: 494 +/- 140 s, 12 months after PMR: 480 +/- 151 s) (p <
0.05), but thallium scintigraphy failed to show improved perfusion of the laser
treated regions. CONCLUSIONS: PMR is a new safe and feasible therapeutic option
in patients with refractory angina pectoris due to end-stage coronary artery
disease. Initial results show significant improvement of clinical symptoms and an
increased exercise capacity but thallium scintigraphy failed to show improved
perfusion after PMR.
PMID- 10778399
TI - [Clinical value of scintigraphy for gastrointestinal bleeding. Experiences in a
large community hospital].
AB - BACKGROUND AND OBJECTIVE: In the majority of cases of gastrointestinal bleeding
the site and cause can be determined by gastroscope. If this is unsuccessful,
radiological and nuclear-medical tests are available. This study was undertaken
to determine the value of scintigraphy in diagnosing of the site of
gastrointestinal bleeding. PATIENTS AND METHODS: The data on 155 patients who,
between 1984 and 1988, had undergone 161 scintigraphies (with 99mTc-labelled
erythrocytes, 5 with 99mTc-Sn colloid) were retrospectively analysed. The results
were compared with other diagnostic tests that had been performed, with the
definitive diagnosis and, where applicable, the findings at surgery. RESULTS: 78
scintigrams (47%) provided positive results. The site of bleeding had been
demonstrated ca. 20 hours after the diagnostic studies had begun. In 47 of the
cases the diagnosis was confirmed by additional tests. The intestine was the most
common site of bleeding. Localization of the source of bleeding by scintigraphy
and other diagnostic tests succeeded in 34 cases, with a 82% concordance between
the tests. No bleeding was demonstrated in 88 scintigrams (53%), including all
those done with Sn-colloid. In 13 cases the final diagnosis suggested that there
had been no previous bleeding and in 43 cases the source of bleeding could not be
determined. In 32 scintigraphically negative cases the source of bleeding was
demonstrated by other tests. But only 2 of the 13 angiograms and none of the 33
double-contrast studies of the small intestine gave positive results. Among the
total number of cases in which bleeding was demonstrated, scintigraphy had a
sensitivity of 71%. CONCLUSION: Because of the long duration of observation,
scintigraphy with 99mTc-labelled erythrocytes proved superior to other diagnostic
tests in the demonstration of the bleeding. By localizing the source of bleeding
in a definite part of the gastrointestinal tract, scintigraphy points the way to
choosing other diagnostic methods or treatment. If the initial endoscopy has
failed, scintigraphy, a method of low invasiveness, should be included when
further tests are planned.
PMID- 10778400
TI - [Hepatocellular carcinoma with extension per continuitatem into the right
atrium].
AB - HISTORY AND CLINICAL FINDINGS: A 61-year-old asymptomatic patient presented with
a hepatocellular carcinoma and a history of 11 cycles of transarterial
chemoembolization. Staging investigations revealed an enlarged hepatic tumour and
a right atrial mass. INVESTIGATIONS: Computed tomography of chest and abdomen
showed a progressive tumour in both hepatic lobes with extension to the inferior
vena cava, through the diaphragma and to the right atrium. TREATMENT AND COURSE:
The patient received supportive treatment and died 3 months later. CONCLUSION:
Inspite the incidence of 1-4%, hepatocellular carcinoma with extension to the
heart has been diagnosed rarely. Although treatment is limited, early diagnosis
by abdominal echography or echocardiography is necessary for the interpretation
of cardiogenic symptoms and the prognosis.
PMID- 10778401
TI - [Hepatocyte transplantation. Possibilities for use and examples of practical
clinical application].
PMID- 10778402
TI - [Self-medication--economic, sociopharmacologic and toxicologic aspects].
PMID- 10778404
TI - [Protection against dismissal after the law for the severely disabled].
PMID- 10778403
TI - [Migraine treatment].
PMID- 10778405
TI - Is it time to address our future? Ethical and financial imperatives in HIV care.
PMID- 10778406
TI - Recent hepatitis C virus studies examined.
PMID- 10778407
TI - Best treatment of jellyfish stings?
PMID- 10778408
TI - Toxic epidermal necrolysis. A widespread, life-threatening blistering reaction.
PMID- 10778409
TI - Could your practice use a waiting room kiosk? How to turn waiting time into
learning time.
PMID- 10778410
TI - Hypertension in patients with diabetes. Strategies for drug therapy to reduce
complications.
AB - Hypertension in diabetic patients must be treated aggressively if patients are to
benefit from reduced risk of morbidity and mortality. Diabetes itself must be
diagnosed promptly, particularly in at-risk patients, so appropriate lifestyle
modifications can be made at the earliest opportunity. Although this may reduce
or delay onset of hypertension, antihypertensive drug treatment should be
initiated in the diabetic patient with even high-normal blood pressure.
Traditional approaches to management of hypertension are inappropriate for most
patients with diabetes. While ACE inhibitors, calcium antagonists, angiotensin II
receptor blockers, beta blockers, and low-dose diuretics, alone or in
combination, all currently have roles in hypertension management, the outcomes of
studies now under way may clarify some still unanswered questions about the
dangerous combination of high blood pressure and diabetes.
PMID- 10778411
TI - Infectious vaginitis. An accurate diagnosis is essential and attainable.
AB - Infectious vaginitis is a common clinical problem. Unfortunately, treatment,
including self-medication, is often instituted before an adequate evaluation has
been performed. An accurate diagnosis can usually be made in the office setting,
and effective pharmacologic treatments are readily available.
PMID- 10778412
TI - A systematic approach to laceration repair. Tricks to ensure the desired cosmetic
result.
AB - An organized, systematic approach to wound repair based on the mnemonic LACERATE
can jog the memory and ensure a successful outcome. This stepwise approach
consists of looking at the wound to assess repair options, anesthetizing and
cleaning the wound, setting up equipment, selecting the proper repair technique,
assessing results, determining the patient's tetanus immunization status, and
educating the patient about wound care.
PMID- 10778413
TI - Pleural effusions in cardiovascular disease. Pearls for correlating the evidence
with the cause.
AB - In patients with cardiomegaly and signs and symptoms compatible with CHF,
unilateral right-sided or bilateral pleural effusions of similar size are likely
to be due to left-sided CHF. Isolated right ventricular failure or chronic
pulmonary hypertension is not usually associated with pleural effusions, and
unrecognized or new-onset left ventricular dysfunction and other causes should be
considered when a patient with cor pulmonale presents with a pleural effusion.
Unilateral left-sided pleural effusions with cardiomegaly may be due to
pericardial disease. Current hypotheses do not adequately explain the laterality
of effusions in CHF or pericardial disease. Clinical and radiographic correlation
is always required; however, the associations described occur often enough to
make them useful in day-to-day clinical practice. When ascribing pleural
effusions to CHF, clinicians must be sure the clinical signs and history "fit the
picture," because pneumonia and pulmonary embolism may also cause pleural
effusions in patients with heart failure. Typical pleural effusions in patients
with uncomplicated CHF (demonstrated by small to medium-sized effusions and the
absence of fever, leukocytosis, pleuritic chest pain, or marked asymmetry in
bilateral effusions) do not require routine diagnostic thoracentesis for
evaluation. A reasonable approach in such cases is treatment of the underlying
CHF and follow-up radiography to monitor for resolution of the effusions. Prompt
diagnostic thoracentesis is indicated whenever atypical features are present and
other diagnoses are under consideration.
PMID- 10778414
TI - Corticosteroids for tuberculosis?
PMID- 10778415
TI - Primary HIV infection. Current trends in transmission, testing, and treatment.
AB - In the changing kaleidoscope of HIV disease, early detection of primary infection
has become increasingly important. Primary care physicians who recognize the
signs and symptoms are in an ideal position to diagnose the disease at an early
stage and to help stem the tide of new infections in the community. In this
article, Drs Yu and Daar discuss current strategies for early diagnosis,
including recommended testing and steps to prevent transmission of the virus, and
present the latest thinking about antiretroviral therapy during primary HIV
infection.
PMID- 10778416
TI - Practical approaches to HIV therapy. Recommendations for the year 2000.
AB - Despite advances in treatment, HIV infection continues to present a daunting
global medical challenge. Rapid development of new pharmaceutical agents has led
to significant increases in the effectiveness of therapy. However, as use of
antiretroviral drugs increases, so does our appreciation of the potential toxic
effects of these agents. In-depth knowledge of HIV pathophysiology and the
characteristics of individual drugs is mandatory for any physician caring for
patients with HIV infection. In this article, Dr Wolfe outlines a practical
approach to HIV therapy based on current consensus and his own recommendations.
PMID- 10778417
TI - HIV-associated metabolic and morphologic abnormality syndrome. Welcome therapy
may have unwelcome effects.
AB - Metabolic and morphologic complications of HAART are probably caused by several
interrelated and complex physiologic processes that are just beginning to be
understood. Whether there is validity to the current theories regarding
mitochondrial toxicity of NRTIs, lipid pathway interruptions of protease
inhibitors, or the host immune response itself as the primary culprit remains to
be seen. In the interim, physicians should use great caution and be circumspect
in their judgment with regard to "quick-fix" treatments of these complications.
Furthermore, scientifically unsupported decisions about switching antiretroviral
agents in an attempt to alleviate a particular toxic effect may place the patient
at risk for antiretroviral-therapy failure. Formal adoption of a case definition
of HAMMAS remains a priority for the scientific community, because anecdotal
observations compiled to date do not yet constitute a discrete syndrome. A clear
case definition, possibly modeled after criteria for defining rheumatic diseases,
will greatly facilitate properly designed research trials to elucidate causes and
possible treatments of this troublesome syndrome.
PMID- 10778418
TI - Designing salvage antiretroviral regimens. Some basic guidelines and use of
resistance testing.
AB - Treatment of HIV infection is rapidly changing from a hit-or-miss hodgepodge of
unknowns, in which nearly anything beneficial was acceptable, to a true science
based on reproducible principles. With this growth in complexity, HIV therapy has
become a valid field of medicine. The potency of available agents, their success
in suppressing the destructive nature of HIV infection, and the increasingly
rapid pace of technology development in this area require that HIV-seropositive
patients be treated by physicians specializing in the field. The growing but
finite number of antiretroviral therapeutic agents demands that a thoughtful,
strategic, long-term approach be formulated. The evolving science of
antiretroviral resistance testing offers great promise for better shaping this
approach, which is still less than straightforward. Potential interactions, some
good and some bad, between mutations within HIV genes will profoundly affect
therapy and are still to be defined. Declaring that a regimen has failed and
choosing a new one to replace it is a complex task, particularly when all the
factors involved are considered (e.g., rising viral load, declining CD4 count,
patient adherence, patient preferences, drug interactions, adverse effects). Care
of HIV-positive patients has always been an art, and now at last it is becoming a
science.
PMID- 10778419
TI - HIV disease in children. The many ways it differs from the disease in adults.
AB - HIV infects and affects children differently than it does adults. An
understanding of the epidemiology of pediatric HIV infection may reveal
opportunities to reduce and perhaps eliminate perinatal transmission. Knowledge
of unique diagnostic features of HIV-exposed newborns and pathogenetic
characteristics reflected in clinical manifestations helps physicians meet the
management challenges presented by children with HIV and their families.
PMID- 10778420
TI - Cancer genetics in primary care. When is genetic screening an option and when is
it the standard of care?
AB - In some families, predisposition to cancer is caused by a germline mutation in a
single gene, which produces an autosomal dominant pattern of cancer transmission.
Several hereditary cancer syndromes have been identified and for many of them,
genetic testing is clinically available. Determining which patients are at risk
for hereditary cancer begins by taking a complete family history. In particular,
a three-generation family history and pedigree can provide valuable information
for both patients and primary care physicians. When the history supports the
possibility of hereditary cancer, a qualified genetic professional can assist
with specific advice about testing and treatment options for the entire family.
If pedigree analysis substantiates a heritable form of cancer, patients should be
thoroughly informed about potential benefits, limitations, and risks of genetic
screening and offered testing as appropriate. The ultimate goal is to reduce
cancer morbidity and mortality through interventions that decrease cancer risk or
increase early detection.
PMID- 10778421
TI - How to handle myasthenic crisis. Essential steps in patient care.
AB - Myasthenic crisis, or respiratory failure requiring intubation and mechanical
ventilation, may be caused by infections, aspiration, physical and emotional
stress, and changes in medication. Although no single factor determines the need
for respiratory support, all patients with questionable respiratory status should
be admitted to the ICU. Because management of crisis includes treatment of the
underlying myasthenia gravis, a neurologist should share in any decisions
regarding care.
PMID- 10778422
TI - Lipid screening in adults. Working to prevent coronary artery disease. Institute
for Clinical Systems Improvement.
PMID- 10778423
TI - Asymptomatic 'streaks' in a healthy young man. Adolescent lumbar striae.
PMID- 10778424
TI - Foodborne and waterborne infectious diseases. Contributing factors and solutions
to new and reemerging pathogens.
AB - Demographic changes and complexities in food production, combined with
complacency about the role of infectious diseases in general and the safety of
the US food supply in particular, have brought about a resurgence in foodborne
and waterborne infectious diseases and, with it, challenges that are
unprecedented in recent times. A vigorous effort is already under way to ensure
that food and water supplies are safe. This renewed attention to food and water
safety must not be an interim response to a perceived short-term threat but,
rather, a long-term effort to protect the population from pathogenic
microorganisms whose wily adaptations will require constant vigilance.
PMID- 10778425
TI - HIV and AIDS update.
PMID- 10778426
TI - Condoms and safe sex.
PMID- 10778427
TI - [The repair processes and cell populations relationship in bone marrow of
patients with acute radiation injury: morphological study].
AB - The results of bone marrow pathomorphologic investigation in patients who died of
acute radiation sickness (3.7-13.7 Gy) after the Chernobyl accident are
presented. Stratification into three consecutive periods was performed according
to the length of postexposure survival (14-96 days) and the morphologic picture
dynamics: 1) bone marrow aplasia (2-3 weeks after exposure) with a domination of
stromal and plasma cell populations, exhibiting the morphologic characteristics
of functional activity; 2) initial repair period (3-4 weeks after exposure) was
characterized by the beginning of hematopoietic proliferation with simultaneous
occurrence of cell death via apoptosis; 3) active repair period (4 and more weeks
after exposure) was defined by increased marrow cellularity (trilineage
regeneration), accompanied by decreased number of plasma cells and occurrence of
large granular lymphocytes.
PMID- 10778428
TI - [The nature of SOS response in E. coli K-12 (uvrA) cells exposed to the different
ultraviolet doses].
AB - The kinetic and dose dependencies of the SOS-induction in E. coli (uvrA) cells
exposed to UV light were investigated. Below 2 J/m2 the rate of the SOS-induction
increased with dose. The maximal level of the SOS-response was proportional to
the UV dose. Pyrimidine dimers were necessary for the induction. In the dose
range 2-10 J/m2 the rate of the SOS-induction decreased with dose. The dose
response curve was non-linear. Pyrimidine dimers were not required for the
induction. The nature of the molecular events leading to the SOS-induction at low
and high doses was discussed.
PMID- 10778429
TI - [Methods of automated cell analysis and their application in radiation biology].
AB - The present review is concerned with the methods of automated analysis of
biological micro-objects and covers two groups into which all the systems of
automated analysis can be divided--systems of flow (flow cytometry) and scanning
(image analysis systems) type. Particular emphasis has been placed on their use
in radiobiological studies, namely, in the micronucleus test, a cytogenetic assay
for monitoring the clastogenic action of ionizing radiation commonly used at
present. It is evident that the problem is acute, with of radiobiologists'
interest in the biological action of low-dose radiation recently increasing. In
addition, the estimation of a low-level damage requires the analysis of a large
number of experimental objects. Examples of using both the methods elsewhere and
actual setups are given. The analysis of advantages and disadvantages of the
methods of automated cell analysis enables us to choose more thoroughly between
the systems of flow and scanning type to use them in particular research.
PMID- 10778430
TI - [The effect of urea, gamma- and UV-irradiation on physico-chemical
characteristics of native and immobilized inulinase].
AB - The immobilization of inulinase by ionexchange AB-26 and AB-17-2P has been made
by adsorbtion and glutaraldehyde methods. The effect of UV-radiation, carbamide
and gamma-rays on the stability of native and immobilized enzyme has been
investigated. The stability of inulinase in relation to denaturation agents has
been shown to increase with the immobilization of ionexchange. The character of
binding with the matrix affects greatly the stability of immobilized enzyme to
physical factors.
PMID- 10778431
TI - [The effect of ionizing radiation on Ca ATPase of erythrocyte membranes].
AB - Erythrocyte ghosts were irradiated with doses of 4 x 10(-3)-10(3) Gy. The
activity of Ca(2+)-ATPase, the kinetic characteristics of enzyme reaction, the
Hill's coefficient, the association constant and a number of La3+ linking centers
were determined. The structural--functional peculiarities of Ca(2+)-ATPase
changes under exposure to 4 x 10(-3) and 40 Gy of ionizing radiation have been
established.
PMID- 10778432
TI - [Autoimmune disorders in liqvidators 11 years after the Chernobyl accident].
AB - We studied long-lasting consequences of the low-doses irradiation on the immune
system of 71 clean-up workers who participated in the emergency work after the
Chernobyl Plant accident in 1986 and 25 healthy donors from Belarus. In sera of
the workers the level of autoantibodies to thyroid gland antigens (thyroglobulin
and microsomal fraction of thyroid gland) was increased in 48% of cases, the
level of autoantibodies to lens oculis antigen was increased in 44% of cases; the
level of circulating immune complexes was elevated in 55%, and the serum level of
thyroglobulin in 60% of people. Immunological disorders were found without any
definite clinical evidences of diseases and this allows us to consider the
examined contingent as a group of risk for the development of autoimmune
pathology in the future.
PMID- 10778434
TI - [The effect of acute external gamma-irradiation and thyroid glands dysfunction on
rat reproductive system and frequency of structural mutations in somatic cells of
pregnant females and their offspring].
AB - Experimental hypofunction of thyroid gland, caused by mercazolil administration,
and acute external exposure to 0.5 and 1.0 Gy of gamma-irradiation were shown to
result in disturbance of reproductive function in puberal females and of
estrogenreceptor interaction, in reduction of pregnancy probability, increase in
pre- and postimplantation lethality of fetuses as well as in rise in the
frequency of structural mutations in somatic cells of pregnant rats and their
offspring.
PMID- 10778433
TI - [Quantitative regularities for clinical manifestations of radiation injury in
large-sized laboratory animals exposed to supralethal radiation doses Gamma
neutron and electron biological effectiveness as influenced by exposure
conditions and dose distribution in the animal body].
AB - The damaging effect of gamma-neutron radiation over a wide neutron-energy range,
with average values of 0.37 and 1.2 MeV, and that of electrons with an average
electron energy of 25 MeV have been compared in dogs and two monkey species
exposed to a broad range of supralethal doses. An analysis of absorbed dose
distribution in critical organs and systems has shown the highest effect of gamma
neutron radiation with an average neutron energy of 1.2 MeV. With severity of
early clinical manifestations of damage as a criterion, electrons have appeared
the most effective. The radiosensitivity of animals grew in the order as follows:
dog-->M. fascicularis-->P. hamadryas.
PMID- 10778437
TI - [Effect of co-polymer 2-methyl-5-vinylpyridine and 2-methyl-5- vinylpyridinium-n
oxide radiation induced myelodepression in mice].
AB - On the model of cytopenia induced in mice by irradiation with a dose of 4.0 Gy it
was shown that injection of examined copolymer (400 mg/kg) 3 h after irradiation
exerts positive effect on haemopoietic system: the decrease of damage and
acceleration of repair processes.
PMID- 10778435
TI - [Relationship between electronic structure and eadioprotective activity of some
indazoles].
AB - Quantum chemical MNDO study of electronic structure for 29 indazoles has been
performed. Statistically significant quantitative relation between some
characteristics obtained and radioprotective activity was found out. Indazole
structures which data predicted for radioprotective activity (survival, %) are on
50% level or more are proposed.
PMID- 10778438
TI - [Lymphocyte subpopulation of human peripheral blood responds to the low doses of
ionizing radiation,interleukin-2 and to both factors].
AB - Increasing of 3H-thymidine incorporation in lymphocytes of human peripheral blood
which depends non-linearly on X-ray dose (3 cGy max) and interleukin-2 (IL-2)
concentration (17.5 Units/ml) is shown. However addition of IL-2 (17.5 U/ml) into
the medium of cells after irradiation (3 cGy) decreases almost to the control the
effects induced by independently shown actions. Lymphocytes subpopulation
responsible for the described phenomena are isolated during the fractionation of
lymphocytes in the density gradient and pH (V-fraction BSA). Cell fraction less
than 1-2% from the isolated lymphocytes is characterized by increasing of
spontaneous corporation of 3H-thymidine, large sizes (d > 8 mkm), decreasing
repair after UV-irradiation. It is believed that low dose irradiation and IL-2
activate this cell subpopulation of "last reaction", and higher doses of these
factors and this both actions stopping 3H-thymidine incorporation initiate
apoptosis. The relation of this sell subpopulation and before proposed
ontogenetical reserve cells is discussed.
PMID- 10778436
TI - [Radioprotective activity and toxicity of copolymer 2-methyl-5-vinyl pyridine
with 2-methyl-5-vinylpyridinium-n-oxide].
AB - In experiments in mice, hamsters and dogs therapeutic radioprotective efficiency
and toxicity of new water-soluble copolymer were studied. It was found that at
intramuscular injection of the copolymer to dogs in a dose of 5 mg/kg 24 h after
irradiation with a dose of 3.30 Gy (LD85/45) it showed pronounced therapeutic
effect (68.1%). In mice and hamsters, the effect was less pronounced: 42-21%
after irradiation with a dose of 8.0 Gy. The copolymer is low toxic substance and
according to the State standards of Russian Federation belongs to the fourth
class (harmless).
PMID- 10778439
TI - [Effect of low doses of ionizing irradiation on viability of cortical
thymocytes].
AB - The cortical thymocytes of rats in whole organism, isolated lobes of thymus and
cells suspension were exposed to ionizing radiation in a wide range of doses (0.1
200 cGy). In contrast to relatively high dose radiation (50-200 cGy), exposure to
doses of 10 cGy resulted in cell death without DNA degradation. The level of
doses lower than 10 cGy (0.5-5 cGy) induced thymocyte death which is independent
of DNA degradation, RNA and protein synthesis. With decrease in radiation dose,
the increase of latent period preceding cell death took place.
PMID- 10778440
TI - [Pharmacological approaches to study of choline- and GABA-receptor sta tes in
neuronal membranes after low doses irradiation].
AB - As a result of the study of both the acetylcholine (10(-10) M; 10(-6) M) and
gamma-aminobutyric acid (10(-9) M; 10(-5) M) effects on active K+ transport in
rat brain cortex slices using any selective antagonists of cholinoreceptors (ChR)
and GABA-receptors (GABA-R) it had been shown that after whole-body 25 cGy
irradiation (1.75 mGy/min) metabotropic muscarinic ChR and GABAB-R were involved
into processes of neurotransmitter modulation, whereas under the normal
conditions they were mediated via ionotropic nicotinic ChR and GABAA-R. Observed
changes were supposed to be an adaptive reaction. Perhaps, postirradiation
structure-functional disorders in receptors were pointed as one of the reasons
leading to essential changes in the interneuronal metabolic communication
processes in CNS.
PMID- 10778442
TI - [Sexual function of male rats exposed to the factors of the Chernobyl exclusion
zone].
AB - The influence of chronic internal and external irradiation in low doses on sexual
behavior and fertility of sexual active animals keeping within the 30-km
Chernobyl exclusion zone was studied. After the 1.5 month consumption of drinking
water containing radionuclides of natural Chernobyl spectrum the decrease in
proportion of sexual active animals and suppression of sexual motivation and
erection were observed. This deviations resulted in the reducing of the
inseminated females number. The dependence between the magnitude of total
absorbed dose and the working of the sexual behavior regulative mechanisms was
obtained. In addition, the reduction of rat fertility took place because of the
increase of preimplantation, but not post-implantation death in in irradiated
females coupled with irradiated males. The irradiation of males with total
absorbed dose on testis 0.23 cGy decreased the fertility because of sexual
behavior disturbance, and this effect was intensified by negative influence of
ionizing radiation in the range of 0.7-7.0 cGy on male gametes.
PMID- 10778441
TI - [The effect of lead on DNA repair in thymocytes of gamma-irradiated mice].
AB - The effects of Pb on the repair of DNA have been studied in the thymocytes of
gamma-irradiated mice exposed to diacetate lead in the drinking water (up to 20
mg/l) for 14-50 days. It is found that lead causes no DNA degradation by itself
and renders its genotoxic action indirectly, via inhibiting the repair of single
strand DNA breaks induced by acute gamma-irradiation of mice. Genotoxic effect of
lead is reversible that becomes evident when exposed animals are maintained on Pb
free drinking water for 1-2 weeks.
PMID- 10778443
TI - [The effect of internal exposure to 90Sr on hematopoietic stem cells in CBA
mice].
AB - After acute intake of 90Sr the changes of d-9 CFUs number in mice (CBA) bone
marrow, spleen and peripheral blood were investigated. The obtained results
indicated similar quantitative changes in bone marrow and spleen CFUs on exposure
to the 90Sr when radiation doses did not cause the decrease in life-time (1.11
kBq/g). Sarcomogeneous doses of 90Sr (29.6 kBq/g) resulted in drastic changes of
hemopoietic system: spleen haematopoiesis activation and suppression of bone
marrow functions. On the first day after 90Sr injection (29.6 kBq/g) the increase
in number of peripheral blood CFUs (circulating pool) was observed.
PMID- 10778444
TI - [Simultaneous action of UV light and hyperthermia on survival and recombination
of yeast: effect of intensity of agents on their synergistic interaction].
AB - Synergistic effects of simultaneous application of ultraviolet (UV) light and
hyperthermia on survival and recombination of diploid yeast cells were studied.
For both test-systems the dependence of the synergistic interaction on UV light
fluence rate and exposure temperature was revealed: the temperature range
synergistically increasing the action of UV light is shifted towards low
temperature values with decreasing of UV light fluence rate. For cell survival,
the dependence of the synergistic enhancement ratio on the exposure temperature
passes through a maximum. A possible qualitative interpretation of these results
is discussed.
PMID- 10778446
TI - [Modeling of different types of size-effect in accumulation of 137Cs in fish from
the cooling pond of the Chernobyl Power Plant].
AB - All known types of size-effect in accumulation of radiocesium in fish are
described on the basis of the dynamic model of distribution and migration of the
radionuclide in aquatic ecosystem. The time-dependent activity of 137Cs in
different age classes of carp and pike-perch from the Chernobyl Nuclear Power
Plant Cooling Pond is calculated. It is shown that during the first year after
the accident the activity of 137Cs in the young generations of fish was higher
(negative size-effect) owing to higher feeding rate of young fish. During the
following years the increase of activity in the older fish generations takes
place (positive size-effect). It is shown that size-dependence is more clear for
the predatory species.
PMID- 10778445
TI - [Modification of the effect of high temperature on biochemical processes by
perturbed geomagnetic field].
AB - The biochemical data on the influence of perturbed geomagnetic field on the
hormonal-mediator regulation systems are presented. The possibility of biological
effects modification under combined action of perturbed geomagnetic field and
high temperature of environment is discussed.
PMID- 10778447
TI - [The study of interaction between 134Cs and potassium in system peat soil-plant
under increasing concentration of macroelement in soil].
AB - The interaction between analogous elements K and 134Cs in the system "peat-soil
plant" was investigated. The values of some parameters of sorption model for
uptake of radionuclides by plants from soil were determined. An attempt to
interpret the processes going on in the studied system under pot experiment from
the viewpoint of soil chemistry was done. Two intervals of potassium
concentration in peat-soil were displayed, with different effect on 134Cs uptake
by plants.
PMID- 10778448
TI - [Results of the studies on radiation ecology and radiation biology at the
Institute of Biology of Komi Science Center of Ural division of Russian Academy
of Science (on 40th anniversary of the Department of Radiation Ecology)].
AB - Information about the foundation and history of the Radiation Ecology Department
and results of the researches on the effect of increased background radiation
level on plant and animal populations, migration of radionuclides in natural
biocoenosies with increased radiation level are presented.
PMID- 10778449
TI - [Nuclear medicine--therapeutic advances into new dimensions?].
PMID- 10778450
TI - [Cerebral perfusion CT: theoretical aspects, methodical implementation and
clinical experience in the diagnosis of ischemic cerebral infarction].
AB - Cerebral perfusion CT using dynamic CT after bolus injection of contrast has
recently been introduced in the clinical management of stroke patients. Based on
the indicator dilution principle various theoretical models can be formulated
which all aim at the quantitative determination of cerebral blood flow (CBF). Our
Perfusion CT approach is based on the "maximum slope" model and allows in
addition to the calculation of CBF parameter images the display of cerebral blood
volume (CBV) and "time to peak" as diagnostically meaningful parameters. This
approach allows the detection of acute ischemia of the supratentorial brain with
a sensitivity of 91% and has proven its value as a routine diagnostic tool for
acute stroke. The combination of various functional maps provides excellent
information regarding the type of ischemia. Although the direct assessment of
ischemia using absolute CBF values is severely restricted by patient dependent
systematic errors, the severity of ischemia may reliably be assessed by using
relative CBF perfusion indices.
PMID- 10778451
TI - [CT perfusion imaging in acute ischemic cerebral infarct: comparison of cerebral
perfusion maps and conventional CT findings].
AB - PURPOSE: To evaluate the findings of acute brain ischemia on different functional
maps of cerebral perfusion CT in stroke patients and to compare the results with
early ischemic changes on conventional CT. METHODS: The baseline CT scans of 45
acute stroke patients were retrospectively evaluated with respect to early CT
findings. For each patient the extent of cerebral ischemia as shown on the maps
of cerebral blood flow (CBF), cerebral blood volume (CBV), and "time to peak"
(TP) was compared and the severity of ischemia was assigned to one of three
levels based on the findings of the CBF image. RESULTS: In 75% of all patients
conventional CT was performed within 2 hours from symptom onset. 29 of 45
patients showed early signs of ischemia on conventional CT, whereas perfusion CT
revealed cerebral ischemia in all patients. Severe ischemia was found in
approximately the same rate of incidence in patients with early CT changes
(55.2%) and in those with normal findings (43.8%). If the perfusion impairment
was judged as mild or moderate the extent of the hypoperfused area was
significantly larger on the CBF and TP images than on the CBV map. This was
significantly different in patients with severe hypoperfusion where a complete
correspondence of the affected area between the three functional maps was found.
DISCUSSION: The use of conventional CT for the assessment of stroke in the
hyperacute phase is limited. Perfusion CT yields excellent information regarding
the severity and extent of ischemia. The use of various perfusion maps helps to
differentiate the core of infarction from the ischemic penumbra zone.
PMID- 10778453
TI - [Radiation exposure during spiral-CT of the paranasal sinuses].
AB - PURPOSE: Determination of the radiation doses in spiral CT of the paranasal
sinuses using a variety of mAs values and scan protocols. MATERIAL AND METHODS:
CT examinations of the paranasal sinuses were performed using an Alderson-Rando
phantom. Radiation dose was determined by LiF-TLD at the level of high risk
organs in the head and neck region for combinations of different scan parameters
(2/3, 3/3, 3/4 mm) and decreasing charges (200, 150, 100, 50, 25 mAs) on a spiral
CT. Additional measurements were performed on three other CT scanners using the
2/3 mm protocol at 50 mAs, and a single slice technique (5/5 mm) on one scanner.
RESULTS: The lowest dose values found were 1.88 mGy for the eye lenses, 1.35 mGy
for the parotid gland, 0.03 mGy for the thyroid gland and 0.1 mGy for the medulla
oblongata using 2 mm collimation and 3 mm table feed at 25 mAs. Maximal dose
values resulted using the 3/3 mm protocol at 200 mAs (31.00 mGy for the eye
lense, 0.65 mGy for the thyroid gland). There were no significant differences
found between the different CT scanners. CONCLUSIONS: Using up-to-date CT
scanners, radiation exposure may be reduced by a factor of 15-20 compared to that
of conventional CT technique. Thus, the exposure of the eye lens comes to only a
thousandth of the value supposedly inducing a cataract, as published by the ICRP.
PMID- 10778452
TI - [3D CISS, 3D MP-PAGE and 2D TSE for the preoperative MRI prior to cochlear
implantation].
AB - PURPOSE: The aim of this study was to determine the presurgical predictive value
of high resolution MRI in patients scheduled for cochlear implantation. METHOD
AND MATERIAL: The presurgical MRI (3D CISS, 3D MP-RAGE with and without i.v.
contrast medium, 2D TSE) findings of 54 patients and the intraoperative situation
reported by the surgeon were compared retrospectively. The surgical and
functional success of the cochlear implantation was evaluated. RESULTS: We found
a high degree of correlation between MRI and intraoperative findings concerning
the patency of the whole cochlea and anomalies as well as in the diagnosis of
pathology of the cochlear, vestibular and facial nerves and in anomalies of the
internal auditory canal. However, in four out of 54 patients there was a false
negative prediction regarding the patency of the cochlea. The sensitivity was 50%
(4/8), the specificity 100% (46/46). Concerning the surgical success the accuracy
was 100%. In all patients MRI gave sufficient anatomical information to the
surgeon concerning the jugular bulb and the facial nerve. CONCLUSION: A high
resolution MRI protocol consisting of coronal 2D T2w TSE, 3D T2*w transverse
CISS; plain and contrast enhanced sagittal T1w 3D MP-RAGE is recommended for the
evaluation of candidates scheduled for cochlear implantation.
PMID- 10778454
TI - [Hybrid 3D visualization and virtual endoscopy in cochlear implants].
AB - PURPOSE: The aim of this study was to demonstrate on a complex anatomical
structure the possibilities and the advantages of a superimposition of a color
coded surface and volume rendering (hybrid rendering) method with the possibility
of the performance of a virtual endoscopy. MATERIAL AND METHOD: In 6 patients
with cochlear implants a high-resolution spiral computed tomography of the
petrous bone was performed. The cochlear implants, the middle and inner ear
structures were visualized using a color-coded surface rendering method, either
shaded or as a grid. The petrous bone was visualized using a transparent volume
rendering method. RESULTS: The hybrid 3D visualization uses the advantages of
both the color-coded 3D surface and volume rendering method. In comparison to the
axial source images, the hybrid 3D visualization thus facilitates a clearer
representation and better assessment of the complex topographical relationship
without loss of diagnostic information. The virtual endoscopy facilitates an
intraluminal visualization and inspection of all color-coded 3D surface- and
volume rendered structures. CONCLUSIONS: The hybrid rendering and virtual
endoscopy make the morphological assessment of cochlear implants easier by the
simultaneous visualization of the surrounding structures and thereby support the
diagnostic imaging methods. This image processing method can be used pre
operatively for the individual planning, simulation, training and further
development of surgical procedures and interventions and post-operatively for the
control of the position and further developments of implants.
PMID- 10778455
TI - [Determination of left ventricular function parameters and myocardial mass:
comparison of MRI and EBT].
AB - PURPOSE: Comparative volumetric assessment of the left ventricle by magnetic
resonance imaging (MRI) and electron beam tomography (EBT) in patients with
ischemic and dilated cardiac disease. METHODS: Thirty-two patients underwent cine
MRI and EBT in the multislice mode. All studies were triggered to the ECG. Left
ventricular ejection fraction (EF), end-diastolic (EDV) and end-systolic volume
(ESV), and myocardial mass (MM) were determined by 3D-volumetry by MRI and EBT
and results were compared. RESULTS: The correlation between MRI and EBT for EF,
EDV, ESV, and MM were r = 0.86, r = 0.95, r = 0.95, and r = 0.93, respectively.
CONCLUSIONS: There is an excellent correlation between MRI and EBT in determining
left-ventricular parameters. Both methods are suitable for volumetric assessment
of the left ventricle.
PMID- 10778456
TI - [Effects of biphasic spiral CT, conventional and iron oxide enhanced MRI on
therapy and therapy costs in patients with focal liver lesions].
AB - PURPOSE: Evaluation of the diagnostic efficacy and cost-benefit of contrast
enhanced CT (CT) and MRI pre- and post-SPIO-particles in focal hepatic disease
with consideration of therapeutic outcome. METHODS: In 52 patients with the
suspicion of primary or secondary hepatic malignancy, biphasic spiral CT and
breath-hold gradient-echo T1- and fast spin-echo T2-weighted MRI pre- and post
iron oxide administration (1.5 T, body-phased-array coil) were compared. The
number of hepatic lesions and the related diagnoses resulting from each imaging
modality were recorded and statistically correlated to the final diagnoses
established by biopsy/OP (34/52), long term follow-up of 12 months (18/52), and a
consensus reading of all imaging modalities considering all clinical imaging
information. The most likely induced therapy resulting from each imaging test was
correlated to the final therapy. Based on data from the hospitals accountants,
the therapy-related costs were estimated without hospitalization costs. RESULTS:
In 34/52 (65.4%) of the cases the correct diagnosis was primarily stated by CT
(sensitivity [se.] 85.2%, specificity [sp.] 44.0%). In additional 10/52 of the
cases unenhanced MRI (se. 91.4%, sp. 75.0%) enabled correct diagnoses, and in
another 6 cases the diagnosis was established only by SPIO-MRI (se. 100%, sp.
86.7%). Considering the possible therapeutic recommendation arising from each
modality, CT would have induced needles therapy costs of 191,042 DM, unenhanced
MRI of 171,035 DM, and SPIO-MRI of 7,311 DM. In comparison to the real therapy
costs of 221,873 DM, this would have corresponded to an unnecessary increase of
therapy costs of 86.1%, 77.1%, and 3.3%, respectively. In two cases (1
hemangioma, 1 regenerative nodule) all modalities failed, causing unnecessary
surgery in one patient. DISCUSSION: In this problem-oriented scenario unenhanced
and SPIO-enhanced MRI proved to be superior to CT regarding diagnostic efficacy.
The cost-benefit resulted mainly due to preserving patients from unnecessary
surgical procedures.
PMID- 10778458
TI - [Low-field MRI of the ankle joint: initial experience in children and adolescents
using an open 0.2 T MR-system].
AB - PURPOSE: To evaluate the feasibility and diagnostic confidence of MRI with an
open low field System (Magnetom open, Siemens, Germany) in children with
predominantly traumatic disorders. MATERIAL AND METHODS: Conventional X-rays and
MRI examinations have been evaluated in 55 children. MRI was performed at an open
0.2 T MR-unit. The study protocol comprised coronal STIR-sequence, an angulated
T2 weighted TSE-sequence and T1 weighted SE-sequence. RESULTS: MRI showed
ligamental rupture in 33/50 (60%) cases. Injuries of the ATFL were most frequent
(27/33); osseous ligamental tears occurred in approx. 50% of all cases. Fractures
of the distal tibia and fibula were diagnosed in 28/55 children. 15/28 cases
showed an involvement of the epiphysis. We found occult fractures in 11/28
children. Fractures, diagnosed by conventional x-rays, were excluded in 6 cases.
Therapy changed in 35/55 patients on the basis of MRI-findings. CONCLUSION: Low
field MRI of the ankle joint in children and adolescents is able to show numerous
pathological conditions. We recommend low-field MRI of the ankle in children with
persistent or unclear pain of the ankle joint and inconspicuous conventional x
ray.
PMID- 10778457
TI - [Arthrography, ultrasound and MRI in rotator cuff lesions: a comparison of
methods in partial lesions and small complete ruptures].
AB - PURPOSE: To evaluate the accuracy of arthrography, ultrasound and MR imaging in
rotator cuff disease. METHODS: 40 patients suffering from subacromial impingement
syndrome for at least three months and who were selected for surgery, underwent
ultrasound, double-contrast arthrography and MR imaging. Patient preselection
focused on partial and small complete tears. RESULTS: 13/26 surgically confirmed
tears were partial tears (articular surface: 10, bursal surface: 2, intra
substance tearing: 1). Arthrography, ultrasound and MR imaging yield a
sensitivity for complete tears of 91%, 69% and 92% with a specificity of 100%,
93% and 93%. For partial tears sensitivity was 50%, 69% and 69% with a
specificity of 100%, 79% and 86%. Concerning evaluation of localisation, extent
and correct classification ultrasound was correct in 17/26 cases, MR in 21/26
cases. CONCLUSION: Arthrography is not helpful in detecting partial tears.
Ultrasound and MR imaging yield comparable accuracy. MR imaging has advantages
concerning better evaluation of extent, location and classification as well as
for the detection of associated pathologies.
PMID- 10778459
TI - [Animal experiment studies on the effectiveness of permanent occlusion of the
hepatic artery in transarterial chemoembolization].
AB - PURPOSE: To evaluate the effect of permanent occlusion of the hepatic artery on
the efficacy of transarterial chemoembolization (TACE) in an animal model.
MATERIAL AND METHODS: 12 days after inoculation of the Morris hepatoma 3924 A in
15 male ACI rats, TACE with Mitomycin C (0.25 mg/kgBW) + Lipiodol (0.2 ml/kgBW)
without (n = 5) and with permanent occlusion of the hepatic artery (n = 5) was
performed. Control group consisted of 5 rats. Tumor volume was determined by MRI
(1.0 T, T1 [TR/TE, 400/14 ms]) before and 12 days after therapy. RESULTS:
Compared to the control group, TACE without and with permanent occlusion of the
hepatic artery showed a significant reduced tumor growth after 12 days (p = 0.017
and p = 0.005). However, permanent occlusion did not improve the retarding effect
on tumor growth (p = 0.9). CONCLUSION: The effectiveness of TACE in an animal
model using a cytostatic-/lipiodol-emulsion is not improved by permanent
occlusion of the hepatic artery.
PMID- 10778460
TI - [Stent artifacts in 3D MR angiography: experimental studies].
AB - PURPOSE: The purpose of this phantom study was to evaluate the visualization of
vascular stents by using contrast-enhanced (CE) 3D MR angiography (MRA). METHODS:
The measurements were performed on a Magnetom Vision operating at 1.5 T with 25
mT/m gradients by using a head coil; a 3D FISP sequence (TR/TE/FA 4.6 ms/1.8
ms/30 degrees) was used. A phantom was designed with a length of 20 cm and
consisted of a plastic cylinder filled with hydrogel. Tubes were used to install
7 different stents (Strecker, Boston Scientific; Cragg, Mintec; Wall, Schneider;
Memotherm, Angiomed; St-Come, Trigon-MTS; Sinus, Optimed; Palmaz, Johnson &
Johnson) with different metal components. The tubes were perfused with a solution
of water and Gd-DTPA. Four radiologists evaluated the image quality. The
measurements of the endoluminal stent diameters were compared with the findings
obtained by digital subtraction angiography. The signal intensities were measured
before (inflow), within (stent) and after (outflow) the different stent types.
RESULTS: The endoluminal diameter of the Cragg stent and the strecker graft were
easily detectable. The signal loss within the lumen of the Wall stent was approx.
10% in relation to the inflow and outflow measurements. The result was an only
slightly reduced image quality. The other grafts (St-Come, Sinus, Palmaz,
Memotherm) showed significant signal losses ranging from 65% to 96%. A correct
diagnosis was not possible within these graft lumina. CONCLUSION: Contrast
enhanced MR angiography can be used to evaluate vascular stents. A prerequisite
is the application of particular commercially available grafts.
PMID- 10778461
TI - [Chloroma (granulocytic sarcoma, myeloblastoma). Clinical aspects and
radiological diagnosis].
AB - Six cases of granulocytic sarcoma are presented. A mediastinal chloroma and a
tumor of the submandibular gland were observed with two patients as single sign
of acute myeloic leukaemia. In one patient a chloroma appeared as first
manifestation of acute myeloic leukaemia. Two patients exhibited the tumor as
first symptom of a blastic crisis of chronic myelogenous leukaemia (femoral bone,
lumbar spine). The sixth patient with a myelodyplastic syndrome showed a chloroma
of the breast. Various radiological procedures were applied including plain
radiography, MRT, CT and mammography. The results are compared with literature.
Principles of therapy were supplemented.
PMID- 10778462
TI - [Radiology of gastrointestinal stromal tumors (GIST) and a case of Carney
syndrome].
AB - Gastrointestinal stromal tumors (GIST) represent an extremely rare group of
tumors, which are mostly of smooth muscle origin like leiomyomas, leiomyosarcomas
and leiomyoblastomas. With the introduction of immunohistochemical analysis an
epithelioid and an autonomic nerve variant can be distinguished. The purpose of
this review is to demonstrate the image morphological appearance of these rare
tumors together with the pathology based upon a retrospective analysis of five of
our own cases since 1997. There are no pathognomonic imaging findings for
characterizing a gastrointestinal stromal tumor; however, it should be included
in the differential diagnosis if one or multiple large, round or oval, well
delineated gastrointestinal tumors occur in combination with central necrosis.
Carney's syndrome is characterized by the syndromal association of a
gastrointestinal stromal tumor (originally: gastric leiomyosarcoma) with an extra
adrenal paraganglioma and a pulmonary chondroma. In this rare syndrome, the
radiological approach is important to diagnose or rule out the--simultaneous or
consecutive--appearance of at least two of the three tumor entities (GIST, extra
adrenal paraganglioma, pulmonary chondroma).
PMID- 10778463
TI - [Hypothenar hammer syndrome: causes, sequelae and diagnostic aspects].
AB - PURPOSE: To investigate the reasons and disease course of Hypothenar Hammer
Syndrome. INTRODUCTION: Occlusion of the ulnar artery at the level of the hamate
bone due to repetitive trauma to the hypothenar eminence is implicated as the
cause of the rarely diagnosed hypothenar hammer syndrome (HHS). The thrombotic
occlusion and the formation of an aneurysm of the ulnar artery and the
superficial palmar arch with possible peripheral embolism of the digital arteries
are a direct cause of the chronic damage to the vessel wall. Generally, HHS is
diagnosed too late for recanalization to be a viable therapeutic option. METHODS:
From 1996 to 1998 the diagnosis of an HHS was made in 8 patients at our hospital.
Etiology, clinical settings and disease course were assessed. RESULTS: Our
analysis suggests that HHS may be caused by a single severe trauma in addition to
repetitive injuries. The pathogenesis of the syndrome is dependent on the
vascular anatomy of the individual hand. Interindividual variations in the
arterial supply of the affected hand influences the clinical symptomatology with
possible masking of arterial occlusions. CONCLUSION: An exact investigation
concerning the pathogenesis of HHS is a precondition for treating the disease and
may help to establish HHS as an occupational disease. MR-angiography may be a new
approach for assessing HHS.
PMID- 10778464
TI - When and how to evaluate a patient with nephrolithiasis.
AB - Nephrolithiasis is a common disorder that afflicts up to 12% of the population
and continues to be a significant cause of patient injury. Evaluation of these
patients should include the assessment of their comorbidities and underlying
medical conditions. Patients who form stones can undergo a streamlined
evaluation. A cause can be found in more than 90% of these patients. With medical
treatment, stone-recurrence rates can be decreased by 85% for calcium oxalate
stone formation, which affects a large proportion of patients. Introduction of
nonspecific medical therapy in uncomplicated calcium stone disease may improve
the quality of life for these patients and allow utilization a simple diagnostic
protocol. This is in contrast to the previous recommendations of disease-specific
therapy. Because patients without complications represent the majority of those
who form stones, a simplified approach greatly reduces the cost of evaluation and
treatment. Underlying medical conditions, however, require disease-specific
therapy. The protocol represented here should aid physicians and patients in the
approach to management of stone disease. The fasting calcium-load test is not
required, and the entire evaluation can be performed in an ambulatory setting in
two visits. Two 24-hour urine samples should be obtained on a random and
restricted diet. Patients who form calcium stones can be subdivided into those
who form hypercalciuric and normocalciuric stones. Patients who form
normocalciuric stones are treated with conservative measures (increased fluid
intake) and potassium and magnesium citrate. Patients who form hypercalciuric
stones are treated with a combination of thiazides and potassium and magnesium
citrate.
PMID- 10778465
TI - Stone disease.
AB - Imaging studies used for the detection and characterization of urinary tract
calculi are presented in this article. Comparisons of traditional imaging studies
are made with noncontrast helical CT scanning, the most recent addition to stone
imaging. Imaging findings for noncontrast helical CT and an approach to dealing
with various combinations of CT studies are also presented.
PMID- 10778466
TI - Helical CT and ureteral colic.
AB - The advantages of nonenhanced helical CT for the diagnosis of ureteral calculi
include rapid scan time and patient throughput, safety (no contrast, less
radiation), cost-effectiveness, high accuracy, minimal invasiveness, and ability
to suggest of alternative diagnoses for flank pain--urologic and otherwise. Size
measurement and location in the ureter, the two most important determinants of
therapy, are precise with CT. It is particularly good for imaging small or
radiolucent calculi, and calculi located at the ureterovesical. Secondary signs
of obstruction and the soft-tissue rim sign are additional aids to the routine
diagnosis of ureteral calculi. CT numbers indicate the fragility and therefore
the likelihood of successful treatment of a calculus. Postprocessing options may
help guide management decisions and may help plan interventions. The authors'
experience after 30 months of using helical CT exclusively in the work-up of
ureteral colic has been extremely favorable. Without hesitation, the authors
believe that nonenhanced helical CT is the study of choice for the work-up of
ureteral calculi.
PMID- 10778467
TI - Medical therapy and new approaches to management of urolithiasis.
AB - A simple, step-by-step approach to diagnosis and medical treatment of stone
disease is described. It uses urinary stone risk profile obtained before and
after dietary modification, history, and minimum diagnostic tests. For each
abnormal stone risk factor, potential causes are discussed and treatment options
are presented. The article concludes with diagnosis and treatment of combined
disturbances.
PMID- 10778469
TI - Secondary and miscellaneous urolithiasis. Medications, urinary diversions, and
foreign bodies.
AB - Secondary stones, those with no "classic" cause, provide unusual diagnostic and
treatment challenges to the urologist. Stones related to medications, to urinary
diversions or augmentation, or to presence of foreign bodies within the urinary
tract occur rarely. Nevertheless, they represent situations that may be corrected
fully by appropriate conservative or procedural therapy, and therefore they must
be included in the differential diagnosis of many patients who present with
symptoms of urolithiasis.
PMID- 10778468
TI - Role of diet in the therapy of urolithiasis.
AB - The data reviewed in this paper indicate that there is compelling direct and
indirect evidence that certain dietary modifications can limit the risk for stone
formation. Fluid therapy should be a front-line approach for all stone formers,
because it is safe, cheap, and effective. Restricting sodium and animal-protein
consumption produces changes in the urinary environment that should benefit the
majority of stone formers, including a decrease in calcium and increase in
citrate excretion. Minimizing the intake of processed goods limits sodium
gluttony. These dietary modifications also reduce cardiovascular risks.
Indiscriminant calcium restriction should be avoided, because it could accelerate
stone formation and violate skeletal integrity. Oxalate restriction should be
considered for calcium oxalate stone formers, especially those with
hyperoxaluria. Specific recommendations for modifying the consumption of other
nutrients cannot be made at this time because of the limited available
information about the resultant effects. The aforementioned goals can be achieved
within the context of a nutritionally balanced diet providing adequate sources of
fruits and vegetables. There is a definite need for better designed studies of
the nutritional effects on stone disease. This would promote a better
understanding of the interplay between the genetic and environmental components
of this disorder.
PMID- 10778470
TI - Kidney stones as a manifestation of hypercalcemic disorders. Hyperparathyroidism
and sarcoidosis.
AB - When hypercalcemia is detected in a kidney stone formation, an intact parathyroid
hormone measurement should be made. Detection of hyperparathyroidism (HPT) is
important to prevent further stone episodes and to avoid the complications of
high serum calcium in other organ systems. Stones in patients with HPT often
contain apatite salts in addition to calcium oxalate because parathyroid excess
may create a renal tubular acidosis. The calculi seen in patients with
sarcoidosis, another hypercalcemic state that may cause stone formation, however,
are usually pure calcium oxalate. Excess generation of 1,25-dihydroxyvitamin D
results in intestinal hyperabsorption of calcium and secondary hyperoxaluria.
PMID- 10778471
TI - Genetic disorders and urolithiasis.
AB - A recent analysis of the McKusick's On-Line Mendelian Inheritance in Man (OMIM)
database revealed over 30 genetic or putatively genetic conditions in which
urolithiasis contributes to the disease pathology at least to some extent. There
is wide clinical, biochemical, and genetic heterogeneity in many of these
conditions.
PMID- 10778472
TI - Intracorporeal lithotripsy. Update on technology.
AB - The number and variety of devices currently available for endoscopic lithotripsy
reflect the reality that no single device is ideal in all situations. Although
the search for the universal lithotriptor continues, the urologist must consider
several factors if faced with the decision of which device to purchase. Perhaps
foremost among these factors is the clinical situation with which one commonly
deals. For example, although the smaller, flexible probes such as EHL or laser
demonstrate considerable utility if used ureteroscopically, the larger stone
burden associated with today's percutaneous nephrolithotripsy population often is
treated more efficiently with one of the mechanical devices employing a larger,
rigid probe, such as ultrasound or the Lithoclast. Similarly, the type and size
of endoscopic equipment at one's disposal have a significant impact on which
device to purchase or use. There are physical constraints affecting which device
may or may not be used, rigid versus flexible endoscope, working channel caliber,
and offset versus end-on-port. The skill and experience of the surgeon is also a
factor of obvious importance, particularly if one is using a modality with a
relatively narrow margin of safety such as EHL. Likewise, the training and
experience of nursing personnel is a factor, especially regarding the use of
lasers, which require certified personnel who are well versed in laser safety.
Finally, in today's environment one must carefully evaluate cost in terms of not
only initial capital outlay but also ongoing charges for disposable and
maintenance items. Thus, the decision of which device to purchase is complex and
requires careful evaluation of all of the previously noted variables. Likewise,
if one is fortunate enough to have more than one device available, the decision
of which lithotriptor to employ requires a similar decision based on sound
surgical judgment.
PMID- 10778473
TI - Extracorporeal lithotripsy. Update on technology.
AB - The development of shock-wave lithotripsy was a serendipitous event. Fortunately,
the significance of this accidental discovery was not overlooked by the engineers
at Dornier and their medical counterparts. There are many components that make up
a lithotripter, but the heart of the lithotripter is its energy source. These
machines often are categorized by the type of shock-wave generator used, and each
type of generator has its own advantages and disadvantages. Unfortunately, no
quantitative value of a shock-wave generator can be correlated to its qualitative
effect. Interestingly, each type of energy source delivers its shock-wave energy
with such distinctiveness that even the crater pattern it leaves in a stone is
unique. New technology and ideas have transformed lithotripters in form and
function so that they bear little resemblance to the original HM-1 prototype.
Ongoing research is attempting to improve ESWL in several different ways, and
advances in shock-wave generation, shock-wave measurement, and stone localization
should result in even more efficient lithotripsy. The application of the time
reversal process to lithotripsy ultimately may enable lithotripters to track
stones and electronically steer shock waves toward the target. Advances like
these herald a time when ESWL, fortunately or unfortunately, will become
automated completely.
PMID- 10778474
TI - Is there a role for open stone surgery?
AB - Modern day urinary-stone treatment involves procedures and techniques that were
not even available 20 years ago. The relatively rapid and sometimes explosive
development of ESWL, percutaneous techniques, and ureteroscopy and intracorporeal
lithotripsy has ushered in the era of minimally invasive stone management. In
many regards, open surgery has such a limited role that its performance often is
regarded as a sign of failure. To think of open stone surgery in this manner is
likely to do a disservice to a small but important segment of the urinary-stone
patient population. The critical responsibility of the urologist treating stone
disease is to be able to recognize those clinical situations in which open stone
surgery may represent at least a viable and reasonable alternative to less
invasive modalities. The duty of the surgeon is then to be able to present this
option to the patient in an unbiased fashion and to effectively perform and
implement this form of treatment if chosen. It is only with this approach that
open surgery will continue to be correctly applied on those rare occasions and
will not become a lost surgical art in the era of minimally invasive surgery.
PMID- 10778475
TI - The vesical calculus.
AB - Bladder calculi account for 5% of urinary calculi and usually occur because of
foreign bodies, obstruction, or infection. Males with prostate disease or
previous prostate surgery and women who undergo anti-incontinence surgery are at
higher risk for developing bladder calculi. Patients with SCI with indwelling
Foley catheters are at high risk for developing stones. There appears to be a
significant association between bladder calculi and the formation of malignant
bladder tumors in these patients. Transplant recipients are not at increased risk
for developing vesical calculi in the absence of intravesical suture fragments
and other foreign bodies. Patients who undergo bladder-augmentation procedures
using a vascularized gastric patch appear to be protected from vesicolithiasis,
perhaps by the acidic environment. Ileum and colon tissues, however, are
colonized by urease-producing organisms, producing an alkaline pH that promotes
stone formation. Children remain at high risk for bladder-stone development in
endemic areas. Diet, voiding dysfunction, and uncorrected anatomic abnormalities,
such as posterior urethral valves and vesicoureteral reflux, predispose them to
bladder-calculus formation. Finally, there are a number of techniques and
modalities available to remove bladder stones. Relieving obstruction, eliminating
infection, meticulous surgical technique, and accurate diagnosis are essential in
their treatment.
PMID- 10778476
TI - Management of residual stones.
AB - Stone-free status is highly dependent on selection of the appropriate surgical
technique, which should be tailored according to the individual stone and patient
parameters. Although a stone-free state is the desired outcome of surgical
intervention of urolithiasis, the authors believe that the presence of
noninfection, nonobstructive, asymptomatic postprocedural residual fragments can
be managed metabolically in order to prevent stone growth adequately. Further
surgical intervention in the case of residual fragments is warranted if the
clinical indications that prompted the original surgery persist.
PMID- 10778477
TI - Chemolysis of urinary calculi.
AB - Irrigant chemolysis was developed to collaborate with open surgery, removing the
residual fragments. With the worldwide diffusion of the procedures performed by
the endourologist in the early 1980s and the present availability of ESWL,
however, direct irrigation of stones has a reduced field of influence even as an
adjunctive measure. Urologists have applied economic analysis to their clinical
practices, and the findings related to irrigant chemolysis made this technique an
unusual procedure. The cost to the providers of medical care, the burden on the
patient in terms of suffering and loss of productivity, and the amount of time
required to liberate the patient even partially from the stones make irrigant
chemolysis an inauspicious scenario. In this era of cost containment and
decreasing length of stay, it is increasingly difficult to justify hospital
admissions for this form of therapy. Being simultaneously more expensive and less
effective than the existing alternatives, local chemolysis should be discarded,
except for special situations, such as patients at high risk for any surgical
procedure. Oral chemolysis preserves reduced indications, for example as an
adjuvant to an endourologic operation or ESWL in special situations. As long as
urinary stones continue to afflict humans, chemolysis is likely to retain a
limited but important role in their management.
PMID- 10778478
TI - Orthotopic urinary diversion in women.
AB - Orthotopic urinary diversions can be performed safely with acceptable morbidity
rates in women. Attention to detail during the surgical dissection of the bladder
neck and vagina is critical to a good outcome. With improvements in orthotopic
urinary diversions, earlier use of a cystectomy for the treatment of minimally
invasive bladder cancer may improve the survival rate in these patients.
PMID- 10778479
TI - [Epilepsy as a symptom].
AB - Epilepsy and seizures are often misinterpreted as identical phenomenon and
treatment of seizures confused with treatment of epilepsy. In this paper the
concept of both epilepsy and seizures are revised and also the more new
etiopathogenics hypothesis, stressing the importance of etiological diagnosis for
a suitable therapy and prognosis, which depends more of the etiology than the
morphology of seizures.
PMID- 10778480
TI - [Corpus callosum agenesis and epileptic seizures].
AB - INTRODUCTION: The corpus callosum is the major neopallial connection between the
two cerebral hemispheres. The corpus callosum agenesis (CCA) is found in 14% of
CNS malformations. The diagnosis is based on neuroimaging procedures
(ultrasonography, CT, MRI). The CCA is usually associated with facial dysmorphia,
developmental delay and epileptic seizures. Two casuistic are studied, one with
necropsies material and another with CCA patients alive, on which CCA was
frequently associated with other CNS malformations, in order to establish the
circumstances in which the epileptic seizures have been observed. DEVELOPMENT: It
is commonly admitted that the presenting signs or symptoms in individuals with
CCA are due to concurrent brain abnormalities and that isolated CCA is
essentially asymptomatic. The CCA is a common component in some malformative
syndromes, frequent in another, and occasional in many of them. The CCA has been
reported in many chromosomal aberrations and less frequently in inborn errors of
metabolism and neurocutaneous diseases. In the casuistic studies of 73 patients
alive, 25 (39%) have presented epileptic fits: in 24 of them the CCA was
associated to another brain abnormalities; in 17 cases, the first seizures was
recorded during the first year, in 6 cases between 1 and 3 years and in cases
after 2 years: the type of epileptic seizures is variable: neonatal convulsions
in 4 cases, infantile spasms in 5, unilateral fits in 3, and partial seizures in
1 case. In the necropsies casuistic with 26 CCA cases, 6 (23%) suffered epileptic
fits, all with another malformations of the CNS; in 3 the onset of the seizures
was during the newborn period, 2 had infantile spasms during the first years and
1 case generalized seizures during the second year. CONCLUSIONS: 1. Epileptic
seizures were observed in 23%-39% of the CCA cases studied. 2. All cases with
CCA, except for one, have also another brain abnormality. 3. In 70% of the cases,
the onset of the fits takes place during the first year. 4. The type of seizures
is variable with predominance of infantile spasms and unilateral seizures.
PMID- 10778481
TI - [Epileptic signs in alterations of neuronal migration].
AB - INTRODUCTION: A wide range of conditions are due to alterations in neurone
migration (ANM). Mental retardation, motor disorders and epilepsy are seen in all
these disorders. Anomalies included with the ANM are those produced at the time
of neuronal migration in the phase prior to neurone proliferation and during the
time following cortical organization. All these have a common characteristic,
namely an anomalous cerebral cortex (cerebral dysplasias). DEVELOPMENT: There is
a high incidence of epilepsy in ANM (60%), appearing early (10% neonatal, 42%
before 1 year old). The frequency of crises increases with age. Extended and
diffused generalized forms presents as epileptic encephalopathies (Ohtahara,
West, Lennox-Gastaut), whilst focal forms are seen as simple motor, partial
crises, complex and secondarily generalized crises with a tendency to status
epilepticus and also to continuous partial epilepsy. In diffuse, extensive forms,
the EEG is characterized by large amplitude theta-delta rhythm activity
(specific) with the presence of rapid activity (15-25 Hz) and of large amplitude
(150-300 microV) which may also be found in other processes. In localized forms
the recordings vary: localized discharges with/without crises, multifocal
discharges in more than two lobes with a defined critical area, positive
discharges, ipsilateral spike-and-wave complexes associated with focal discharges
or with normal recordings. We review different types of ANM: in the phase of
proliferation (hemimegalencephalia), the agyria-paquigyria complex; in phase of
migration: type I lissencephalias (Miller-Dieker), layered heterotopias (double
cortex), type II (cobblestone) lissencephalias and neuronal heterotopias, and in
the phase of organization of the cortex: polymicrogyria and the
esquissencephalias I and II. CONCLUSIONS: The functional prognosis in ANM depends
on the control of the crises rather than on the extent of the lesion. Surgical
treatment leads to 42% good or excellent results.
PMID- 10778482
TI - [Sleep as a method of the study of epilepsy].
AB - It has been well known from the literature that sleep and epilepsy have strong
reciprocal influences and this is true for all kinds of epilepsies. The
electroencephalographic paroxysmal activity increases in slow wave sleep and the
localization of the primary epileptogenic area is more reliable in paradoxical
sleep. The video-polygraphic recording is a mandatory methodology in the study of
the different types of epilepsies.
PMID- 10778483
TI - [Epileptic signs of metabolic origin].
AB - INTRODUCTION: It is very difficult to identify metabolic causes of epileptic
crises. This is partly because metabolic disorders are not fully understood and
partly because the complementary tests required for their identification can be
undertaken only in a few laboratories. DEVELOPMENT: We describe the
characteristics of the metabolic disorders which may most frequently lead to
epileptic crises occurring during the neonatal period, the first year of life,
between the ages of one and six years and between six and fifteen years of age.
We also emphasize the findings which may help in orientation towards diagnosis of
these metabolic disorders, and the complementary tests required for confirmation.
PMID- 10778484
TI - [Epileptic signs of neonatal hypoxia-ischemia].
AB - INTRODUCTION: Neonatal convulsions are usually symptomatic and originate mainly
from a hypoxic-ischemic (H-I) lesion. The high incidence of crises and their
serious sequelas have led us to carry out this retrospective study. PATIENTS AND
METHODS: We studied 54 histories of neonatal H-I and epileptic crises, analyzing
45 variables and evaluating their diagnostic concordance. RESULTS: In 20 children
meconium was detected during gestation and, to a lesser extent, infection and
hemorrhage. Birth was dystonic on 48 occasions, 37 at term and 12 preterm. In
most cases (27) birth weight was in accordance with gestational age. Apgar scores
were always less than 5. The crises, occasional or daily in most cases, were of
subtle semiology in 29 children, followed by generalized tonic (23), focal clonic
(13), general clonic (11), multifocal clonic (7), focal tonic and multifocal
myoclonic (6), focal myoclonic (4) and generalized myoclonic (2) crises. Only 7
EEGs were done during crises (1 normal, 3 with anomalies and 3 with slow basal
activity). Paroxystic anomalies were only found on 10 EEGs done between crises.
Cerebral echography was the method most used and most useful. Very frequently
changes were observed in other organs as the expression of a multisystemic
disorder. Most children had abnormalities on neurological examination. In most
cases, classical anti-epileptic drugs were used intravenously, and new generation
drugs were given if the crises persisted. After an average of 16-19 months of
follow-up, 13 children had died and 34 no longer had crises. However, only 20 of
the surviving children were considered to be normal, 14 had severe mental
retardation, 6 moderate and one slight retardation. CONCLUSIONS: Neonatal H-I is
the main cause of epileptic crises in the RN period, with a high percentage
mortality and severe neurological sequelas. The crises are usually well
controlled by classical anti-epileptic drugs, and are an excellent marker,
together with the Apgar score and gestational and placental changes. The
appearance of normal EEGs during periods of crises should make us doubt the
authenticity of subtle crises, perhaps corroborated by a good therapeutic
response.
PMID- 10778485
TI - [Introduction to the study of peroxisomal disorders].
AB - The peroxisome is an organelle found in all nucleated cells of mammalian. Its
name is due to H2O2 formation as result of cell respiration catalyzed by oxidases
and catalases and play and important role on myelination and neuronal migration.
Peroxisomes are formed by assembling of membrane proteins (structural, receptors
and transporters) into peroxisomal membrane. Peroxisomal proteins are encoded by
nuclear genes, synthesized on cytosol ribosomes and imported into peroxisomal
matrix, mediated by receptors and transporters membrane proteins. There are two
main categories of peroxisomal disorders: disorder of peroxisome biogenesis
exemplified by Zellweger syndrome, where multiple peroxisomal protein, functions
are deficient and disorders which involves a single peroxisomal protein,
exemplified by X-adrenoleukodystrophy, where the organelle is apparently intact.
PMID- 10778486
TI - [The peroxisome: structure, function and biogenesis].
AB - The peroxisome is the most recently identified subcellular organelle.
Understanding of its function, particularly in various aspects of lipid
metabolism and its biogenesis, has increased rapidly during the last decade. At
least 15 peroxisomal disorders have been identified, and 12 of these involve the
nervous system severely.
PMID- 10778487
TI - [The diagnosis of peroxisomal disorders in Spain during the period 1987-1997].
AB - INTRODUCTION: Peroxisomal disorders are divided into two groups: a) Those with
alterations in multiple peroxisomal functions, and b) With alterations in only
one peroxisomal function. DEVELOPMENT: During the period 1987-1997, using very
long chain fatty acids, plasmalogens and phytanic acid as diagnostic parameters,
we diagnosed 116 cases of peroxisomal disorders in Spain. The most frequent (76%)
was found to be X-linked adrenoleukodystrophy (X-ALD). Of the five phenotypes
described in this condition, the adult cerebral form is seen in a higher
percentage in the Spanish population (14%) than in other populations studied (1
3%). Defects in the assembly of peroxisomes made up 18%; the commonest phenotype
was that of Zellweger's syndrome (13 cases), followed by neonatal
adrenoleukodystrophy (5 cases) and infantile Refsum (2 cases). In the latter two
patients, study of the hepatic peroxisomes showed a mosaic distribution.
Rhizomelic punctate chondroplasia made up 3%, isolated beta-oxidation defects 2%
and defects of plasmalogen synthesis 1%. In X-ALD, diagnosis of an initial case
led to the detection of 12 presymptomatic and 70 heterozygote persons. Prenatal
diagnoses were made on 10 occasions and 7 fetuses found to be affected. The
introduction of the study of ALDP expression in the fibroblasts and the profile
of the organic acids in the urine has led to improved diagnosis of these
disorders.
PMID- 10778488
TI - [Peroxisomal disorders: classification and overview of biochemical
abnormalities].
AB - The peroxisomal disorders are subdivided into two major categories: those in
which the organelle is not formed normally (disorders of peroxisome biogenesis),
and those that are associated with defects of single peroxisomal proteins. The
Zellweger cerebrohepatorenal syndrome is the prototype of the peroxisome
biogenesis disorders. It has been shown to be due to defective import of proteins
into the organelle. Ten distinct molecular defects can lead to the failure of
import.
PMID- 10778489
TI - [Clinical symptoms of generalized peroxisomal disorders].
AB - INTRODUCTION: In generalized peroxisomal disorders, the clinical picture is not
always obvious enough to orientate the diagnosis at an early stage of the
disease. Although classic Zellweger syndrome can seldom be misdiagnosed, unless
we ignore this kind of pathology altogether, the other phenotypes (neonatal
adrenoleukodystrophy and infantile Refsum disease) are not always clearly
delineated. Above all, the diagnosis may be difficult if we expect the patient to
closely correspond to the cerebro-hepato-renal syndrome prototype. DEVELOPMENT:
Thus, we must establish a series of crucial signs and symptoms that, taken
together, make us suspect a peroxisomal disease and order the corresponding
biochemical screening. In our experience, craniofacial dysmorphia may be
misleading in the less severe phenotypes and is probably the most subjective
feature. In contrast, an infant with widely open fontanels and axial hypotonia,
in special if failure to thrive and/or hepatomegaly are associated, must be
considered suspicious enough to make us think of a peroxisomal disorder and
perform a metabolic screening. Later on in life, the neurological picture and
psychomotor delay become more and more clear, and sensorineural blindness and
deafness are virtually constant.
PMID- 10778491
TI - [Treatment of generalized peroxisomal disorders with docosahexaenoic acid ethyl
ether].
AB - INTRODUCTION: We found that patients with the Zellweger syndrome and other
generalized peroxisomal disorders have a dramatic decrease of docosahexaenoic
acid (DHA, 22:6n-3) in the blood, brain, retina and other tissues. DHA is
believed to play an important role in the brain and retina. DEVELOPMENT: Patients
with the Zellweger syndrome and its variants have severe cerebral and retinal
defects that could be related to their DHA deficiency. With this rationale, we
have been treating peroxisomal-disorder patients with a DHA derivative of a high
degree of purity (DHA ethyl ester, > 90% pure) since 1991. So far, we have
treated 13 DHA-deficient peroxisomal patients, one with the classic Zellweger
syndrome and 12 with milder variants of the disease. This paper presents the
follow-up of these DHA-treated patients. In summary, we have found important
improvements in liver function, in the plasmalogen levels and in the two ratios
26:0/22:0 y 26:1/22:0, diagnostic of the disease. We have also found clear
clinical improvements in most cases. Most significantly, magnetic resonance
imaging has shown advances in brain myelination, so far in 6 of the treated
patients. CONCLUSION: We strongly recommend treatment with DHA ethyl ester in all
DHA-deficient patients with generalized peroxisomal disorders. Logically,
treatment should be started as soon as possible, in the hope of preventing
cerebral and visual damage.
PMID- 10778490
TI - [Disorders associated with alterations in single peroxisomal proteins, including
X-linked adrenoleukodystrophy].
AB - X-linked adrenoleukodystrophy is the prototype of the disorders that involve a
single peroxisomal protein, and it is by far the most common peroxisomal
disorder. The gene that is defective in this disorder is a peroxisomal membrane
protein involved, in an as yet undefined manner, in the degradation of very long
chain fatty acids. All of the peroxisomal disorders can be identified pre- and
postnatally by non-invasive tests.
PMID- 10778493
TI - [Child neuropsychology in the next millennium].
AB - INTRODUCTION: The progress made in recent decades in neuropsychology has meant a
major advance in the recognition of sub-types of various disorders of nervous
development. DEVELOPMENT: Recognition of symptomatology by means of a fragmental
study of the components of all the different systems for obtaining information
brings to light new therapeutic options. The different neuropsychological tests
are used to study not only the final development of a particular ability but also
how this has been achieved. Study of the type of mistakes made by each child
permits recognition of the neuro-cognitive profile used. Cognitive rehabilitation
of different processes presenting in infancy and adolescence offers the
possibility of acquiring an alternative system of learning to minimize or
substitute for deficiency. This is possible in cases affecting secondary or
tertiary processing areas. CONCLUSIONS: The recognition of alternative routines,
used to overcome specific disorders of nervous system development, makes one
reflect on the way in which information is acquired, processed and produced by
the brain and the possibility of generating auxiliary strategies for processing,
even in healthy brains, so that perhaps options will be available in the case of
future lesions (aphasia, Alzheimer's disease, etc.).
PMID- 10778492
TI - [Therapeutic strategies for peroxisomal disorders].
AB - Therapies are emerging for some of these therapies, and include dietary
modification, pharmacological agents, and tissue transplants. Animal models have
been developed for several of these disorders, and will increase understanding of
disease mechanisms and facilitate the evaluation of current and new therapies,
including gene therapy.
PMID- 10778494
TI - [Children at risk for learning disorders].
AB - INTRODUCTION: To find what is meant by normal learning, it is essential to
understand learning difficulties not only from the anatomical but also from the
functional point of view. DEVELOPMENT: We review the literature concerning risk
factors for learning difficulties in order to treat them early on and attain
satisfactory long-term development. CONCLUSIONS: Learning difficulties are the
largest groups of disorders in everyday neuropaediatric practice. It should be
remembered that in most children with learning difficulties there are undiagnosed
preexisting neurological disorders, which come to light on reaching an age at
which improved academic achievement is obligatory.
PMID- 10778495
TI - [Neurocognitive and pharmacological approach to specific learning disorders].
AB - INTRODUCTION: Specific learning disorders are distinguished from general
development disorders since, in general, only a certain number of processing
mechanisms are involved whilst the remainder are unaffected. DEVELOPMENT: The
classification proposed by the DSM-IV takes a step towards clinical understanding
and use of a common nomenclature. However, neuropsychological assessment is
essential to understanding clinical subtypes. The neuro-cognitive approach, when
taking into account the processing systems affected or involved, should include
the strategies and principles of a cognitive-behavioural approach, accompanied by
computerized cognitive training. Pharmacological treatment uses drugs with
different modes of action depending on the specific neuropsychological
characteristics of each type of disorder of nerve development. We discuss the
clinical use of various drugs in view of investigations, present and past:
methylphenidate for the dys-attentional subtype of ADHD; piracetam in
developmental dyslexia of dysideatic type; citocolina in the infantile dysphasias
of sensory input predominance, thiapride in dysfluencial and combined subtype of
ADHD; pipamperona in behaviour disorders and the hyperactive-impulsive subtype of
ADHD, with or without associated and selegilina in the dysattention subtype of
ADHD and the dysgraphias of the subtype with predominance of calligraphy and
spatial disorders.
PMID- 10778496
TI - [Psychopedagogic rehabilitation of learning disorders in school children].
AB - In this paper we discuss the main contributions of the three theoretical
perspectives of psychology--conductual, cognitive and socio-historical--of
education when there are learning difficulties. Finally, we emphasize the
inefficacy of interventions and the need for implication in both the cognitive
and meta-cognitive problems, and the socio-effective and conductual problems of
these students.
PMID- 10778497
TI - [Language development: psychosocial requirements for communication].
AB - This work describes the social and psychological characteristics of attachment
adults. These features are considered as sociopsychological prerequisites for the
child language development. The focus is put on the so-called no formal
education, suitable for these attachment adults who are involved affectively and
emotionally. Some educational strategies to be practised at home are also
presented.
PMID- 10778498
TI - [Specific disorders in the language development: neurobiological basis].
AB - Studies of twins, familial aggregates and particular phenotypic conditions have
shown an inherited basis for some dysphasias or specific developmental language
impairments (SLI). This predisposition is usually multifactorial but the analysis
of some families allows to postulate an autosomal dominant transmission of
deficits in specific modular aspects of linguistic competences. Moreover,
neuroimaging studies have shown modifications of normal volumetric
interhemispheric asymmetries, and in group of SLI with receptive prominent
disorder coexist epileptiform activity in wakefulness and non-REM sleep EEG; in
some of these cases, antiepileptic drugs, specially steroids, can significantly
ameliorate the language processing. As many patients with SLI have a difficulty
for discrimination of subtle temporal indices, a hypothesis can also be made of a
dysfunction in various subcortical structures (thalamus, basal ganglia,
cerebellum) modulating the cerebral cortex in phonological processing.
PMID- 10778499
TI - [Logopedic intervention in language learning disorderss].
AB - The objective of this study is to analyze, from the conceptual point of view,
logopaedic intervention in disorders of acquisition of language. We describe the
'model of intervention at three levels': reinforcing stimulation of language,
restructuration of language and substitution of language. We analyze the concepts
of 'ambiental intervention', from the naturalist point of view, that of
functional exercises and of directed or formal exercises. We study the variables
which affect the specificity of logopaedic treatments. As a specific example we
describe intervention in auditory perception.
PMID- 10778500
TI - [Language in autistic disorders].
AB - Autism is a developmental disorder affecting social relationships, communication
and flexibility of thought. These three basic aspects of autism may present in
many different forms and degrees. Therefore autism should be considered to be a
spectrum of autistic disorders rather than a single strictly defined condition.
The spectrum of autistic disorders extends from intelligent individuals with
acceptable social integration, to severely retarded patients with scarcely any
social interaction. Language is almost always affected either in its formal
aspects or in its usage. Autistic linguistic disorders form a specific language
disorder (developmental dysphasia) and a pragmatic disorder linked both to the
primary language problem and to the social cognitive deficit. We discuss the
different linguistic syndromes observed in autistic patients with special
emphasis on the semantic-pragmatic disorder.
PMID- 10778501
TI - [Stereotypes, developmental disorders and neuroimaging studies].
AB - INTRODUCTION: We believe that it is of great interest, in neuropediatric clinic,
to value the molar behavior disorders and to accomplish the corresponding
molecular alterations in the central nervous system. PATIENTS AND METHODS: We
studied 26 patients diagnosed of serious disorders of the development, that were
presenting a typical clinic with manual stereotypes. We choose at random 5
children to practice them a study of metabolic neuroimaging through the Positron
Emission Tomography with 18Fluoro-Deoxi-Glucose (PET-FDG). RESULTS AND
CONCLUSIONS: The conclusion, more meaningful, is that the children with serious
disorders of the development present a mature failure in the neuro-function
circuits of the thalamus, as well as the cortical connection and association
areas. This clinical situation is reinforced by the results of the PET-FDG, that
presents a characteristic metabolic image of the autism children, with a
bilateral decrease of the capitation of FDG, mainly in regions as thalamus,
frontal and temporary lobes.
PMID- 10778502
TI - [Therapeutic intervention in infantile autism and generalized developmental
disorders: self-injury and self-stimulation].
AB - INTRODUCTION: In this article we present a review of the aetiology and treatment
of self-injury and self-stimulation in infantile autism and in generalized
development disorders. We summarize 20 years of study and investigation in the
treatment of these serious behaviour disorders, in a pioneer institution in
Spain: the centre for rehabilitation 'El Cau' in Castellon. DEVELOPMENT: We
describe the most frequent behaviour disorders, with particular reference to self
injury and self-stimulatory behaviour. Models explaining the aetiology and
treatment are described in a brief general review of the subject, and we consider
explicative models which integrate different treatments (in family and
institutional contexts) by means of family therapy, psychoeducational models and
social support networks.
PMID- 10778503
TI - [Psychological manifestations of epilepsy in childhood].
AB - Epilepsy in infancy, far from being a condition in which only convulsive
phenomena occur, also has important cognitive and behavioral components, which
may be more important than the epileptic seizures itself. The psychological
repercussions of epilepsy are the sum of various factors due to the epilepsy
itself, the treatment given, the side-effects of drugs given and the manner in
which the patient copes with his illness. The epilepsy itself shows the effect of
the causal lesion, lesions associated with this causal lesion and the immediate
and long-term effects of the resulting paroxystic discharges. The most
significant manifestations are: attention disorders, problems of social
relationships and problems of conduct. Treatment and diagnosis should not be
limited to treatment of the crises. In all epileptic children neuropsychological
assessment should be directed towards the detection and surveillance of the most
common problems. This has a considerable effect on the quality of life of the
epileptic patient. In cases of benign idiopathic epilepsies, which occur most
frequently in childhood, evaluation of conduct using Achenbach's questionnaire
(CBCL) may be sufficient, together with assessment of the ability to pay
attention on Continuous Performance Test (CPT) and a quantitative and qualitative
evaluation of intellectual capacity using the WISC-R or K-ABC scales.
PMID- 10778504
TI - [Epilepsy and learning: a neuropsychological approach].
AB - INTRODUCTION: The quality of life of an epileptic patient largely depends on the
interplay of the control of the convulsive crises and the degree to which higher
mental functions are affected. Some types of epilepsy lead to mental retardation
during development and with others the basic cerebral mechanisms for processing
data are damaged and this may lead to transient or permanent cogniscitive
deterioration. DEVELOPMENT: There are certain important clinical factors such as
the site of the discharge regarding the lobe, hemisphere, type of cerebral area
involved and the age of the patient. We describe the clinical features of each
type of epilepsy with respect to focal or generalized involvement. The
subclinical effects of continuous discharges affects processing in the areas
involved and therefore intellectual function, thus leading to a secondary
learning disorder. The neuropsychological tests used in investigation of higher
cerebral functions in epilepsy include, in general, tests to assess speed of
processing, attention, memory, reasoning and visuospacial ability and frontal
executive functions. CONCLUSIONS: These tests should be sufficiently sensitive so
as to detect minimal changes in the state of the illness, the time elapsed and
the medication given. Anticonvulsant drugs may themselves cause changes in mental
functions. There may often be mixed neurocognitive behaviour depending on the
drug used. There may also be transient cognitive deterioration.
PMID- 10778505
TI - [Headaches in childhood: association with sleep disorders and psychological
implications].
AB - INTRODUCTION: Infantile headache is an increasingly important cause of medical
consultation, due both to its increasing prevalence and its subsequent
repercussion on the child's life. Also, certain sleep disorders (parasomnias) are
commoner in infancy than in later life. The relationship between headache and
sleep disorders is not clear, but from the literature it would seem that there is
an association, at least in some types of headache, in adults. PATIENTS AND
METHODS: In order to determine possible alterations in patterns of sleep in
children with chronic headache (a history of headache during the previous six
months occurring more than 15/month or 180 days/year) we carried out a
comparative study on a total of 224 Valencian children aged between 3 and 15
years. Of these, 97 children had been diagnosed as having primary chronic
headache (cases) in a specialized. PAEDIATRIC NEUROLOGY CLINIC: Twenty seven
healthy children with no history of headache (controls) were found amongst the
pupils of a Valencian state school. Using a purpose-designed sleep questionnaire,
data was obtained as to the duration, hygiene, quality and incidence of
parasomnia in the two groups. RESULTS: The results showed a decrease in duration
of sleep at night, increased frequency of poor sleep hygiene, increased
prevalence of certain sleep disorders (insomnia and nocturnal wakening), of
certain parasomnias (somnambulism, somniloquy, enuresis) and of nocturnal
snoring, all of statistical significance (test chi 2 with p < 0.005). CONCLUSION:
In children there is an association between chronic headache and certain sleep
disorders.
PMID- 10778506
TI - [Disorders associated with the Gilles de la Tourette syndrome].
AB - INTRODUCTION AND OBJECTIVE: Diagnostic criteria of the Gilles de la Tourette
syndrome hasn't changed in many years. Lately, associated symptoms have became
very important. In this study, we want to stress the relationship between
precocious diagnostic criteria, proposed by us, and the associated
symptomatology, specially the obsessive-compulsive disorder. PATIENTS AND
METHODS: We have studied 30 patients with the diagnosis of Gilles de la Tourette
syndrome with associated obsessive-compulsive disorder by means of our criteria,
evaluating their fiability when confronted to the Shapiro et al and DSM III-R
criteria. CONCLUSIONS: New criteria, that we have named Munoz-Gomez, were useful
for the precocious diagnosis of this syndrome and for evaluation of the
associated symptomatology.
PMID- 10778507
TI - [Neurobiology of attention deficit-hyperactivity disorder].
AB - This is a review of current relevant evidences concerning the nature and
pathophysiological mechanisms of attention deficit hyperactivity disorder (ADHD).
From a neuropsychological point of view, clinical symptoms seem to arise from an
early dysfunction of the executive system. Patients with ADHD have deficits in
inhibitory control, cognitive flexibility, working memory and self-motivation,
and all of them account for the attentional deficit in non automatic information
processing. Decrease in prefrontal, caudate and pallidal structures, which
sustain the executive function, have been found in neuroimaging volumetry.
Cognitive evoked potentials obtained during attentional tasks have augmented
latencies and abnormal topography. A dopaminergic deficit in the structures
sustaining executive function is postulated from the results in experimental
animal models and from functional neuroimaging studies in patients, and this seem
to be the foundation of the favorable outcome with psychostimulants in correctly
diagnosed patients. Psychopedagogic interventions are necessary to help the
patient in order to get an optimal internal locus of control, which is necessary
for attention and impulsiveness inhibition, and also for compensation of
associated disorders.
PMID- 10778508
TI - [Neuropsychological subtypes of the inattention and hyperactivity syndrome].
AB - INTRODUCTION: One of the commonest neurological development disorders is the
syndrome of inattention with hyperactivity, ADHD. The complex neurobiological
network which intervenes in paying attention permits us to maintain a basal state
of alertness, to focalize and maintain attention for long periods, select the
stimulus-signal required and analyze its components, and also to simultaneously
carry out processes of input-output and performance (tutorial, controlling).
DEVELOPMENT: Damage to the various systems participating in 'paying attention'
leads to a syndrome of inattention, with or without hyperactivity. The
distinction into clinical sub-types (combined, mainly lacking attention or mainly
hyperactive and impulsive) gives a primary differentiation of the syndrome.
However, from the neuropsychological point of view, some degree of heterogeneity
within the groups which defines academic behaviour and conduct may also be
recognized. This type of study permits a more specific neuro-cognitive and
pharmacological approach. Some clinical characteristics of the syndrome of
inattention improve with different drugs, such as the state of alterness
(methylphenidate), impulsivity (pipamperone) and selective attention (tiapride).
However, this treatment is symptomatic and in most cases is useful to accompany
the ultimate biological development of the neocortical control mechanisms.
CONCLUSIONS: A neuro-cognitive approach which permits acquisition of habits of
control, functional strategies, sequential planning of activities and per- and
post-functional surveillance is fundamental. The EFE programme for training
executive functions is directed towards working with the damaged processing
mechanisms in each neuropsychological subtype.
PMID- 10778509
TI - [Studies of evoked potentials in children with the syndrome of attention deficit
and hyperactivity].
AB - INTRODUCTION: The syndrome of attention deficit and hyperactivity (SADH) is a
frequent diagnosis in school children, based on clinical criteria systematized in
the DSM-IV and the ICD-10. Nevertheless, there is no biological marker
sufficiently sensitive and specific to confirm the diagnosis and clarify the
physiopathological mechanism of this disorder of psychological development.
DEVELOPMENT: For this, endogenous evoked potentials especially the P300 wave,
related to the processes of selective attention and sensory elaboration of
discriminatory stimuli, have been used. In order to study the type of alteration
in the P300 wave of children diagnosed as having SADH, and the changes induced
after two months of treatment with methylphenidate (MF), 12 children were
studied. The paradigm of oddball type auditory stimulation was used. The latency
and wavelength of the P300 wave at the Cz electrode before (basal) and 2 hours
after taking 10 mg of MF were determined. Comparative analysis of the average
latencies before and after administration of MF showed significant differences (p
< 0.01), with a shortening of the latency following treatment. No significant
changes were seen in amplitude. In only two patients (17%) were there no
differences in the latency of response before and after treatment, and no
response at all to treatment. CONCLUSION: These results show the practical
usefulness of study of the P300 wave in children with SADH, at least for
monitoring the efficacy of pharmacological treatment.
PMID- 10778510
TI - [The evaluation of the effects of pharmacological treatment of children with
attention deficit hyperactivity disorder].
AB - In this study we approach problems related to the dosage and specific action of
methylphenidate, its effects at cognitive and social levels, possible side
effects and limitations to its usage, and methods for evaluation of the response
to treatment in the school environment. We make special mention of the importance
of both parents and teachers being familiar with these problems.
PMID- 10778511
TI - [Attention deficit hyperactivity disorders: current controversy regarding
definition, epidemiology, etiology and treatment].
AB - In this paper a review of the current literature is carried out to provide
information of consensus and divergence points from the Scientific Community,
about interesting questions in the hyperactivity disorder. The core and
traditionally debated questions are boarded, including the concept, assessment,
prognosis and etiology to finish up with the comment concerning the treatment
approaches. It's a concluded that although there aren't definitive answers, the
different approaches of conceptualization are getting closer, a better
understanding of neurobiological disorder basis, and the need of facing its
assessment and treatment from multidisciplinary and multi-methodological
assumptions is taking place.
PMID- 10778512
TI - [Tics in childhood].
AB - INTRODUCTION: Tics in infancy often cause problems in social relationships of
children and worry to their immediate family. We review some aspects of these
abnormal movements and mention Gilles de la Tourette disease, discussing the
graduation from simple tics to the more severe tics which occur in this illness.
DEVELOPMENT: Tics are the commonest abnormal movements in infancy, when
paroxystic disorders are excluded. We review the scant progress made in more than
100 years regarding their aetiology and pathogenesis. Current strategies for the
treatment of tics are considered (not only pharmacological) and choice of drug
depending on associated disorders.
PMID- 10778513
TI - [Movement disorders: dystonias which are apparently psychosomatic. Torsion
dystonias].
AB - In neuropediatric clinical practice, disorders of movement include a wide
diversity of conditions, amongst which the dystonias are uncommon in our
practice, although they have to be considered amongst the possible diagnoses in
some cases. The great variety of clinical symptoms and age of onset together with
the nonspecific, erratic clinical course make diagnosis difficult. Some clinical
pictures of genuine torsion disorders may be confused with hysterical conversion
disorders, somatizations or Munchausen's syndrome. Diagnosis requires clinical
knowledge of both conditions--torsion dystonia as opposed to hysteria or a
conversion reaction--and considerable ability and experience. Genetics and
molecular studies have helped to clarify some difficult diagnostic problems and
facilitated both diagnosis and treatment. In a diagnostic video session we show
the case of a seven year old boy who initially presented with a dystonic
disorder. There was some doubt as to the aetiology and different types of
treatment were given by different specialists. The true diagnosis was reached
after molecular genetic studies.
PMID- 10778514
TI - [Dystonia responsive to L-dopa].
AB - A comprehensive literature review is made. Clinical characteristics, differential
diagnosis, treatment with L-dopa and underlying pathological conditions are
commented.
PMID- 10778515
TI - Rationale anti-snake venom therapy: randomized controlled trials or clinical
judgment.
PMID- 10778516
TI - Randomized controlled trial on the effective dose of anti-snake venom in cases of
snake bite with systemic envenomation.
AB - Snake bite is the common cause of morbidity and mortality in India. Snake
antivenom, although very effective, is expensive, scarce, and associated with
side effects. The conventional dose may not be required in all cases and a
smaller dose may be as effective. A randomized double blind controlled trial was
conducted to compare the effect of lower versus the conventional (high) dose.
Patients presenting within 24 hours of snake bite with hematological or
neurological evidence of systemic envenomation were included in the study.
Patients were randomized either to receive high dose (2 vials over 1 hour,
followed by 2 vials over 4 hours and repeated 4 hourly until clotting parameters
normalized and then 2 vials as infusion over 24 hours) or low dose (2 vials over
1 hour, followed by 1 vial over four hours, repeated 4 hourly until clotting
parameters were normalized and then 1 vial as an infusion over 24 hours). Thirty
one patients received high dose and 29 a low dose. The mean dose of antivenom
used was significantly different in the two groups (8.9 and 4.7, respectively).
There was no mortality. The duration of stay was 4.94 and 3.48 days,
respectively. There was no difference in the transfusion, dialysis or ventilation
requirement of the two groups. Low dose regimen is more effective and required 5
vials less than the conventional dose. Each vial costs Rs. 200, so the estimated
savings is Rs. 1000 per patient.
PMID- 10778517
TI - Age at onset, gender distribution and intraarterial blood pressure changes in
atrioventricular node-dependant tachycardias.
AB - OBJECTIVE: Atrioventricular nodal reentrant tachycardia (AVNRT) and
atrioventricular reentrant tachycardia (AVRT) utilising accessory pathways
constitute the vast majority of paroxysmal supraventricular tachycardia (SVT). We
studied the age at onset, the gender distribution and the intraarterial
hemodynamics of these tachycardias. METHODS: The data of 224 patients who
underwent electrophysiology study (EPS) and radiofrequency ablation was analysed.
The age at onset of tachycardia was assessed by a careful history. The
intraarterial BP was noted during sinus rhythm (SR), immediately after
tachycardia onset (T0) and 15 seconds after the onset of tachycardia (T15).
RESULTS: The age at onset of tachycardia was a decade later for AVNRT (48 +/- 10
years) than for AVRT (37 +/- 11 years). There was no gender preponderance in the
AVNRT group (60 males, 56 females) while a male preponderance was seen in the
AVRT group (71 males, 37 females, p < 0.01). There was a marked fall in the
intraarterial systolic BP in both groups at the onset of tachycardia, from 143 +/
24 mm Hg to 108 +/- 16 mm Hg (p < 0.05) for AVNRT and from 139 +/- 25 mm Hg to
107 +/- 18 mm Hg (p < 0.05) for AVRT. There was no correlation between the rate
of tachycardia and the extent of fall of BP. CONCLUSION: Hospital-based data in
an Indian setting found a similar pattern of age of onset of AV node-dependant
tachycardia as in Western literature. However, unlike in Western studies, no
female preponderance was seen in the AVNRT group. The fall in systolic BP at the
onset of tachycardia is significant, similar in the two groups and independent of
the rate of tachycardia.
PMID- 10778518
TI - Resurgence of malaria in Mumbai--is escalating chloroquine resistance a cause?
AB - OBJECTIVES: Given the steep increase in the incidence of malaria in the city of
Mumbai in the nineties, we decided to study the causes for the same as well as
analyse the resistance pattern of P. falciparum in the city. METHODS: Smear
positive cases of acute uncomplicated P. falciparum malaria who presented to us
in 1994, 1995 and 1996 were analysed for their response to full dose chloroquine
(25 mg/kg over 3 days). Samples of those patients who satisfied criteria for in
vitro resistance testing to chloroquine and other antimalarials, were also
studied. Chloroquine level in all patients was studied on Day 3 by HPLC. In vivo
response to chloroquine was studied in 30, 71 and 78 patients while in vitro
response was studied in 17, 35 and 30 patients respectively in the above years.
RESULTS: We found in vivo chloroquine resistance figures of 36.78%, 45% and 53.8%
in the years '94, '95 and '96 and the in vitro resistance figures of 41.17%,
54.28% and 66.6% in the same years. CONCLUSIONS: Our previous studies documenting
15% chloroquine resistance in 1993 and the increasing incidence in subsequent
years suggests resistance to chloroquine as one of the causes of resurgence and
maintenance of malaria in the city. If patients of uncomplicated P. falciparum
malaria are to be treated with chloroquine, rigorous monitoring for nonresponse
and timely rescue medication is necessary. Alternative antimalarial drugs such as
mefloquine, artemisinin derivatives and sulfadoxine-pyrimethamine should be used
in patients where this is not possible.
PMID- 10778519
TI - An evaluation of oxidative stress in diabetes mellitus during uncontrolled and
controlled state and after vitamin E supplementation.
AB - OBJECTIVE: The study was conducted on 50 patients (10 insulin dependent diabetes
mellitus (IDDM) and 40 non-insulin dependent diabetes mellitus (NIDDM) of
recently diagnosed diabetes mellitus. The main objectives of the study were: 1.
To evaluate oxidative stress at uncontrolled stage. 2. To evaluate the effect of
optimal control on oxidative stress irrespective of type of drug therapy used. 3.
To further evaluate the effect of vitamin E supplementation on oxidative stress
after achieving optimal control. This was done in order to explore anti-oxidant
effect of vitamin E. METHODS: Fifty patients of uncontrolled diabetes of less
than 1 year duration and without any overt complications were studied. The
parameters of oxidative stress included malonyl-di-aldehyde (MDA), reduced
glutathione and vitamin E levels in the blood. They were done at three stages
i.e. (a) In uncontrolled stage, (b) At controlled stage and (c) After 4 weeks of
vitamin E supplementation in dosage of 400 mg daily. The parameters of control
included fasting blood sugar < or = 140 mg%, post prandial < or = 200 mg and
HbA1c < or = 7% (analysed by prepared kit). RESULTS: The significantly raised
levels of MDA and decreased levels of reduced glutathione and vitamin E during
uncontrolled stage of diabetes indicated free radical stress inducing lipid
peroxidation. The significant fall of MDA and rise in reduced glutathione and
vitamin E levels in blood after optimal control revealed its beneficial effect on
oxidative stress. The levels were not normalised but still stayed higher than
controls. After 4 weeks of vitamin E supplementation, further fall in MDA and
rise in reduced glutathione suggested beneficial effect of vitamin E over and
above the optimal control. Vitamin E estimation in blood at this stage did not
constitute parameter of oxidative stress as it was provided from outside but was
done to know the compliance of patients. Normalisation or near normalisation was
not achieved with vitamin E therapy indicating persistence of oxidative stress.
CONCLUSION: There was an evidence of oxidative stress in diabetes which decreased
with optimal control and further declined after vitamin E supplementation
indicating anti-oxidant effect of vitamin E alone. Normalisation of oxidative
stress was not achieved. A further study is desired to study the effect of
vitamin E for longer period at least 3-6 months before a definite conclusion is
drawn.
PMID- 10778521
TI - Modification of antihistaminic activity of cetirizine by nimesulide.
AB - OBJECTIVE: To study the effect of nimesulide (4-nitro-2-phenoxymethane
sulfonanilide) a non-steroidal anti-inflammatory drug, on antihistaminic activity
of cetirizine. METHOD: A randomized, double blind, cross over study was conducted
in ten healthy male volunteers. Wheal and flare responses to histamine were
measured by performing intradermal injection of histamine (2 micrograms base)
diluted in 100 microliters volume of saline on the volar surface of forearm, on
four occasions (0, 2, 4, and 6 hrs. post-dosing). Each volunteer was randomized
to receive either treatment A (cetirizine 10 mg + placebo) or treatment B
(cetirizine 100 mg + nimesulide 100 mg), with one week wash out period in between
each administration. Wheal and flare responses were measured ten minutes after
each histamine injection. RESULTS: Both cetirizine 10 mg alone and cetirizine 10
mg + nimesulide 100 mg, decreased wheal and flare responses significantly at 2
hrs. and this continued till 6 hrs. post-dosing. This decrease was highly
significant when cetirizine was given along with nimesulide. CONCLUSION: The
results suggest a synergistic effect exhibited by the combined use of cetirizine
with nimesulide.
PMID- 10778520
TI - Brucella spondylitis: an important treatable cause of low backache.
AB - OBJECTIVES: This study was undertaken to see if brucella spondylitis existed as a
cause of backache in Mumbai and to identify the clinical setting in patients of
backache where brucella serology is indicated. METHODS: In 18 months (June 1996
Dec. 1997) we performed tube agglutination test (TAT) for Brucella melitensis and
abortus on 72 patients of low backache from Orthopaedics Department of a teritary
health centre. All 72 patients satisfied the inclusion and exclusion criteria
designed to exclude radiologically detectable congenital or degenerative cause of
backache. RESULTS: Six out of 72 patients were seropositive for brucellosis. All
six patients had either history of animal contact or ingestion of raw milk or
milk product (cheese or paneer). The lumbosacral backache was severe, radiating
to the legs and straight leg raising test was significantly positive, they had
marked tenderness on spinous process of lower lumbar vertebrae. Changes of
brucella spondylitis were present on plain radiogram of lumbosacral spine in
three patients. Four patients had abnormalities on bone scintigraphy. CONCLUSION:
Low backache of brucella spondylitis closely simulates pain of prolapsed
intervertebral disc. Serologic testing for brucellosis is an important step in
management of such patients, especially when history of animal contact or raw
milk or milk product ingestion is present, as the disease can be eminantly
treated with antibiotics.
PMID- 10778522
TI - Response to exercise and ambulatory blood pressure monitoring in essential
hypertension.
AB - To evaluate the relationship of ambulatory blood pressure (ABP) recording and
blood pressure response to exercise, 58 essential hypertensive patients, not
taking any drugs, had symptom-limited treadmill stress test (TST) within 48-96
hours of ABP, TST time, blood pressure increase, decrease, mode of increase and
decrease, were independent of ABP systolic (SBP) and diastolic blood pressure
(DBP) over 24 hours, day time and night time (p = ns). SBP decrease immediately
after exercise were independent of ABP data. TST achieved heart rate was related
to both 24 hours SBP (r = -0.64, p = 0.00005) and DBP (r = -0.55, p = 0.00001) in
both day (r = -0.64, p = 0.00001 and r = -0.54, p = 0.002) and night (r = -0.52,
p = 0.0001 and r = -0.46, p = 0.003) time periods. Therefore patients with
achieved heart rate < 100% (n = 18) had higher 24 hour SBP (148 vs 132 +/- 2 mm
Hg, p = 0.0006) and DBP (92.4 +/- 6.4 vs 84 +/- 6.2 mm Hg, P = 0.006) day and
night. It is concluded that there is no overlap of diagnostic information using
blood pressure. Values in TST or ABP although achieved heart rate in exercise is
inversely related to severity of hypertension.
PMID- 10778523
TI - Mallory-Weiss syndrome: clinical features and management.
AB - OBJECTIVE: To report the clinical features, endoscopic appearance, management and
outcome of patients with upper gastrointestinal bleeding due to Mallory-Weiss
tear seen at our institution during the last seven years. METHODS: A
retrospective study of all patients with upper gastrointestinal bleeding seen
during the last seven years was performed. Patients who were bleeding from
longitudinal non-perforating tear(s) of the gastro-oesophageal mucosa were
included in the study and their clinical features, endoscopic appearance
management and outcome were recorded. RESULTS: During the study period 426
patients with upper gastrointestinal bleeding were seen. Sixty-six (15.5%) of
these were found to have bled or were bleeding from Mallory-Weiss tear(s). Twenty
seven (41%) patients with Mallory-Weiss tear had no antecedent nausea, retching,
abdominal pain or vomiting. Two patients had portal hypertension and a solitary
case bled from an iatrogenic tear induced during routine upper gastrointestinal
endoscopy. Multiple bleeding episodes were seen in 12% of cases. Twenty (30%)
patients needed endoscopic sclerotherapy. Haemostasis was achieved in all. Except
retrosternal pain, no procedure related complications were seen. CONCLUSIONS:
Mallory-Weiss tear is a common cause of upper gastrointestinal bleeding. Nearly
half of the patients have no antecedent symptoms and presented for the first time
with upper gastrointestinal bleeding. Endoscopic therapy is very effective and
safe in producing haemostasis in these patients.
PMID- 10778524
TI - Alpha tocopherol concentration in serum of critically ill patients.
AB - OBJECTIVE: Alpha tocopherol is the biologically and chemically active form of
vitamin E and is the most abundant lipid-soluble antioxidant in humans protecting
the cell membranes. Serum concentration of the antioxidant alpha tocopherol was
measured in critically ill patients in whom the excessive generation of reactive
oxygen species could compromise antioxidant defence mechanisms. METHOD: Alpha
tocopherol concentration in serum was measured spectrofluorometrically in
critically ill patients admitted in intensive care unit and age matched healthy
adults, patients with diabetes mellitus (DM) and chronic myeloid leukaemia (CML)
served as control. RESULTS: Alpha tocopherol levels were significantly lower in
critically ill patients (p < 0.001) as compared to healthy control subjects and
those in two other disease groups (DM, CML) in which reactive oxygen species are
reported to be increased. Elderly patients and patients who stayed longer than 8
days had lower plasma concentration of vitamin E. CONCLUSION: These findings
indicate that antioxidant defence could be considerably compromised in these very
sick patients and vitamin E supplementation may be beneficial in increasing their
antioxidant reserve.
PMID- 10778525
TI - Lipid peroxidation in leukaemia.
AB - OBJECTIVE: Free radicals have been implicated in the pathogenesis of leukaemias,
so the degree of lipid peroxidation was studied as a marker of disease activity
in patients of leukaemia. METHODS: Lipid peroxidation product malonyldialdehyde
(MDA) was estimated in serum from 30 patients of leukaemia by thio-barbituric
acid reaction before and after chemotherapy. There were 10 patients of acute
myeloid leukaemia (AML), 5 with acute lymphocytic leukaemia (ALL), 15 with
chronic myeloid leukaemia (CML) of which 10 were in chronic stable phase and 5 in
blast crisis. Twenty healthy age and sex matched individuals served as control.
RESULTS: There was a significant increase in MDA levels in AML and ALL patients
and serum MDA levels were higher in the active phase of disease than in
remission. We observed a direct correlation between peripheral leucocyte counts
and MDA levels. In CML, MDA levels were higher, more so in the patients who were
in blast crisis. Patients of CML blast crisis who achieved remission showed a
significant decrease in MDA levels as compared to those without remission.
CONCLUSION: We observed a significant increase in MDA levels in active phase of
acute as well as chronic leukaemia than those in remission. The proposed
mechanism for high MDA is that myeloid cells are a major source of superoxide and
other oxygen metabolites which lead to lipid peroxidation. MDA estimation in
leukaemia can be of help in detecting type of leukaemia, response of therapy, and
to predict the chances of relapse.
PMID- 10778526
TI - High altitude koilonychia.
AB - OBJECTIVE: To study the incidence of koilonychia in the residents of high
altitude. METHODS: Nails of all the patients attending the Medical Outpatient
Department (MOPD) of a multispeciality medical camp at Kaza in Himalayas (height
12,500 feet above sea level) were looked for the presence of koilonychia and were
included for the study. Those residing below 10,000 feet were excluded from the
study. A detailed history was taken and a thorough physical examination was made
in each. Routine laboratory investigations were undertaken. Serum ferritin levels
were estimated in seven. RESULTS: Koilonychia was present in 6.99% of the
patients (67 out of the 986). There were 29 males and 37 females within the age
range of 37 to 78 years. Sixty four were high landers since generations and three
were high landers from 2nd generation onward. All were right handed. Koilonychia
was in the nails of both upper and lower limbs in 14, in the nails of upper limbs
in 49 and in the nails of lower limbs in 18. In the upper limbs it was in all the
fingers in 42, in thumb, index and middle fingers of right hand in 12 and of left
hand in nine. In the lower limbs it was bilateral in the first three toes in
nine. Chronic obstructive pulmonary disease was in 29, ulcer like dyspepsia in
24, osteoarthritis of knee in 17, hypertension in 14, pulmonary tuberculosis in
eight, anxiety neurosis in five, pneumoconiosis in two and squamous cell
carcinoma of lung in one. The haemoglobin in all was normal and serum ferritin
level of the seven patients estimated was also normal. CONCLUSIONS: Koilonychia
at high altitude is present in 6.99%. It is due to retardation of nail plate
growth and is more common in upper limbs.
PMID- 10778527
TI - Infections and atherosclerosis in the Indian context.
PMID- 10778528
TI - Pictorial CME. Reiter's syndrome with keratoderma blenorrhagica.
PMID- 10778529
TI - Growth hormone therapy.
AB - Growth hormone therapy with rhGH (recombinant human growth hormone) has been
recommended for treatment of GH deficient short stature in children, repeated
hypoglycemias in infancy and early childhood due to GH deficiency, short stature
accompanying chronic renal failure prior to renal transplantation and Turner's
syndrome. It is now increasingly recommended to adults with GH deficiency
following pituitary tumour surgery or irradiation or idiopathic hypopituitarism.
There are other indications for its use where evidence for protein catabolism is
very strong such as burns injury. The end points of GH therapy in children
include achievement of desirable adult height or a growth rate velocity of < 2.5
cm/year. In adults GH deficiency, GH therapy is intended for improvement of
general well being, body composition and metabolic markers of GH function.
PMID- 10778530
TI - Building related illnesses and indoor air pollution.
AB - Building related illnesses are a common problem in developed countries and are
expected to increase rapidly in urban India. Although objective physical
abnormalities are not generally found except in a few specific diseases like
Legionnaires' disease, the symptoms can be uncomfortable and even disabling. In
this review we initially introduce the concept of indoor air pollution and
building related illnesses. Subsequently we review the sources of and exposure to
the pollutants along with their health effects and the approach to a patient of
suspected building related illness. We conclude by discussing the measures for
the control of indoor air pollution.
PMID- 10778531
TI - GLUT-4, tumour necrosis factor, essential fatty acids and daf-genes and their
role in glucose homeostasis, insulin resistance, non-insulin dependent diabetes
mellitus, and longevity.
AB - GLUT-4 receptor, tumor necrosis factor-alpha (TNF-alpha), essential fatty acids
(EFAs) and their metabolites and daf-genes seem to play an important and
essential role in the maintenance of glucose homeostasis, and in the pathobiology
of obesity and non-insulin dependent diabetes mellitus (NIDDM). Daf-genes encode
for proteins which are 35% identical to the human insulin receptor, a
transforming growth factor-beta (TGF-beta) type signal and can also enhance the
expression of superoxide dismutase (SOD). On the other hand, EFAs and their
metabolites can increase the cell membrane fluidity and thus, enhance the
expression of GLUT-4 and insulin receptors. In addition, EFAs can suppress TNF
alpha production and secretion and thus, are capable of reversing insulin
resistance. Melatonin has anti-oxidant actions similar to daf-16, TGF-beta and
SOD. Hence, it is likely that there is a close interaction between GLUT-4, TNF
alpha, EFAs, daf-genes, melatonin and leptin that may have relevance to the
development of insulin resistance, obesity, NIDDM, complications due to NIDDM,
longevity and ageing.
PMID- 10778532
TI - Ion channels and channelopathy.
PMID- 10778533
TI - Angina--an Indian disease.
PMID- 10778534
TI - Epstein-Barr virus induced non-Hodgkin's lymphoma as a presenting manifestation
of acquired immune deficiency syndrome.
AB - A 30 year old, human immunodeficiency virus (HIV) positive patient presented with
fever and intra-abdominal lymphadenopathy. Cytology smears from the nodes showed
a high grade Non-Hodgkin's lymphoma (NHL) which was B cell in origin. NHL was the
acquired immune deficiency syndrome (AIDS) defining disease in this patient.
Polymerase chain reaction (PCR) studies on tumour tissue showed presence of
Epstein Barr Virus.
PMID- 10778535
TI - Myoglobinuria and transient acute renal failure in a patient revealing
hypothyroidism.
AB - Muscle involvement in hypothyroidism commonly manifests as fatigue, myalgias,
stiffness and slowed reflexes. We report a case of transient acute renal failure
related to rhabdomyolysis and myoglobinuria in a 40 year old man that revealed
the diagnosis of hypothyroidism with myopathy. The patient had proximal muscle
weakness and tenderness, markedly raised muscle enzymes and deranged renal
functions that normalised with thyroid replacement therapy. Hypothyroidism,
though rare, should be considered a definite and authentic cause of
rhabdomyolysis.
PMID- 10778536
TI - Uncommon presentations of pontine haemorrhage.
PMID- 10778537
TI - Tuberculosis of the breast.
AB - Nowadays, tuberculosis of the breast is relatively rare compared to other forms
of extrapulmonary tuberculosis. The incidence of tuberculosis of the breast has
decreased mainly due to effective antituberculous chemotherapy. We report two
cases of tuberculosis of the breast.
PMID- 10778538
TI - Brucellar spondylitis.
PMID- 10778539
TI - Parthenium hysterophorus (Congress grass) as allergen in allergic airway disease.
PMID- 10778540
TI - Sustained ventricular tachycardia in a case of aconite poisoning.
PMID- 10778541
TI - Phenytoin sodium induced diabetes insipidus.
PMID- 10778542
TI - Eosinophilic meningitis.
PMID- 10778543
TI - Liposarcoma of the mediastinum--a rare cause of haemorrhagic pleural effusion.
PMID- 10778544
TI - Myelofibrosis with myeloid metaplasia due to tuberculosis.
PMID- 10778545
TI - Topical aspirin-chloroform in the treatment of zoster associated pain.
PMID- 10778546
TI - Bioequivalence of two brands of sustained release theophylline brands.
PMID- 10778548
TI - Digital index--a new way of numerical assessment of clubbing.
PMID- 10778547
TI - Correlation between clubbing and exophthalmos and/or pretibial myxoedema in
Graves disease.
PMID- 10778549
TI - Knowledge of universal precautions among undergraduate medical students.
PMID- 10778550
TI - Hypovitaminosis D in patients attending a rheumatology clinic at a tertiary
referral clinic.
PMID- 10778551
TI - Paracetamol induced urticaria.
PMID- 10778552
TI - Neurocysticercosis: clinical and diagnostic dilemma.
PMID- 10778553
TI - Cysticercus immunoblot assay in patients with single, small enhancing lesions and
multilesional neurocysticercosis.
AB - A single, small (< 20 mm), ring or disc shaped contrast enhancing lesion located
at the cortical-subcortical junction with minimal or no surrounding edema on
computed tomography is the commonest mode of presentation of neurocysticercosis
in the Indian subcontinent. Serum samples of 37 patients with these single, small
enhancing lesions (SSEL's) and five patients with typical multilesional
parenchymal neurocysticercosis were tested by the electro-immunoblot transfer
(EITB) assay and the enzyme linked immunosorbent assay (ELISA). EITB was positive
in 18 patients (48.64%) and ELISA was positive in 21 patients (56.76%) with
SSEL's. On the other hand EITB was positive in all five patients (100%) and ELISA
was positive in four patients (80%) with multilesional neurocysticercosis. The
low sensitivity of the EITB in the SSEL's is probably linked to an insufficient
immune stimulation provided by a single cysticercus cyst.
PMID- 10778554
TI - Clinical profile of polymyositis in Kashmir valley.
AB - OBJECTIVES: The present study is a retrospective and prospective study of 24
cases of idiopathic inflammatory myopathies from Kashmir valley. The study was
conducted to depict the clinical profile of polymyositis from this part of the
world. METHODS: The diagnosis of polymyositis/dermatomyositis was established by
following the criteria of Bohan and Peter (1975). Besides relevant clinical
examination, investigations like complete blood count, ESR, muscle enzymes, LE
cell phenomenon, antinuclear antibodies and rheumatoid factor were also done.
Electrophysiological study and open muscle biopsy was performed in 21 and 24
cases respectively. RESULTS: The mean age at presentation was 34 years with 62.5%
cases presenting in fourth decade. Pelvic girdle weakness was observed in all the
24 cases. Male:Female ratio was 1:1.4. Four (16.8%) cases had associated collagen
vascular disease. No case was associated with malignancy or childhood vasculitis.
Raynauds' phenomenon was seen in seven (29.1%) cases. Creatine phosphokinase and
lactic dehydrogenase was elevated in 22 (91.6%) and 12 (50%) cases respectively.
Electromyography revealed myopathic features in 74.3% cases. Muscle biopsy
revealed features of inflammatory myopathy in 22 (91%) cases. CONCLUSIONS: The
conclusions drawn from this study are as follows: a. Younger age at presentation
b. Shorter duration of illness at presentation c. Increased frequency of
Raynaud's phenomenon as compared to other Indian series. d. No case of
polymyositis/dermatomyositis associated with malignancy or childhood vasculitis
was seen. e. Biochemical, electrophysiological and histopathological features
suggestive of shorter duration of illness were observed.
PMID- 10778555
TI - Clinical and pathological profile of 73 patients with lung carcinoma: is the
picture changing?
AB - OBJECTIVE: A prospective study was undertaken to study the clinical features and
pathological cell type of primary lung carcinoma in our institute. METHODS:
Seventy three patients were included in the study over a period of three years.
These were investigated according to a study protocol which included a detailed
history regarding the onset and progress of the disease, smoking habits, x-ray
chest, computed tomography of the chest and upper abdomen, and flexible
bronchoscopy with brushings and biopsy. RESULTS AND CONCLUSIONS: 32.85% of
patients were non-smokers. The male-female ratio was 4.2:1. Male sex, age > 50
years and history of smoking are still a risk factor for lung carcinoma. Tobacco
smoking of 20 pack-years or more is significantly associated with the incidence
of squamous cell carcinoma compared to other cell types. Adenocarcinoma (28.8%)
was the most common cell type observed. It was also the most common cell type in
central location (32.8%). Adenocarcinoma was the most common cell type diagnosis
amongst females (50%) and non-smokers (43.5%). Computed tomography done in 47
patients diagnosed additional eleven patients with rib or vertebral metastases in
addition to the three diagnosed by chest roentgenology. Computed tomography
diagnosed significant mediastinal lymphadenopathy in 16 patients in whom
mediastinal lymphadenopathy was not suspected on chest roentgenology. Computed
tomography confirmed liver metastases in four patients diagnosed by
ultrasonography and additionally in three more patients. Bronchial brushing
cytology yielded positive results in 51.72% of central tumours and 40% in
peripheral tumors. Yield of endobronchial biopsy was 59% and transbronchial
biopsy was sixty percent. At presentation 74.1% patients with non-small cell
carcinoma were inoperable and in case of small cell carcinoma 75% had extensive
disease. Fiberoptic bronchoscopy with brushings and biopsy, and computed
tomography of the chest and upper abdomen are useful investigations in the
diagnosis of lung carcinoma.
PMID- 10778556
TI - Role of radionuclide perfusion study in cold solitary thyroid nodule for
diagnosis of malignancy: a complimentary diagnostic modality to fine needle
aspiration cytology.
AB - One hundred and forty eight subjects with euthyroid solitary thyroid nodules
(STN) were taken up for radionuclide perfusion study. They were found to have a
cold STN on 99mTc thyroid static scan. All had fine needle aspiration cytology
(FNAC), and except for subjects with chronic lymphocytic thyroiditis, were
subjected to surgery for tissue diagnosis by histopathology. The diagnostic
findings in these patients of solitary thyroid nodules were correlated with the
histopathology. Radionuclide perfusion study is considered useful to
differentiate benign from malignant cold thyroid solitary nodules with high
degree of sensitivity (95%) and specificity (87.9%).
PMID- 10778557
TI - Epilepsy surgery in India: All India Institute of Medical Sciences experience.
AB - OBJECTIVES: Surgical treatment of epilepsy should be considered an important
alternative to medical therapy. The identification of a suitable candidate, pre
operative evaluation requires a multidisciplinary team. The specific diagnostic
studies required depend on the operative strategy and objective of surgical
treatment. METHODS: In twenty patients with medically intractable epilepsy, who
had clinical evaluation, electroencephalography (EEG), video-EEG monitoring using
scalp electrodes, high resolution magnetic resonance imaging (MRI),
neuropsychology, single photon emission computed tomography (SPECT) was done to
localise the seizure focus. If the investigations were concordant resective
surgery was performed. In case of frequent falls, atonic and tonic seizures, with
generalised/multifocal discharges on EEG, a callostomy was done. Surgical outcome
was assessed using Engel's 4 point scale. RESULTS: In 18 patients the seizure
focus was localised, 13 had temporal lobectomy, five extra-temporal resection,
and two had callosotomy. Fifteen patients had a follow-up of more than eight
months, mean 20.5 (range 8-35 months), 13 had outcome I (seizure free), two had
outcome II (occasional seizures), one-outcome III. Three were lost to follow-up
and one patient died. There were no major post-operative complications.
CONCLUSIONS: Surgical treatment of epilepsy is a safe, effective mode of therapy.
Suitable candidates should be identified early and referred to appropriate
centres.
PMID- 10778558
TI - The prevalence of antiphospholipid antibodies in cases of recurrent pregnancy
loss.
AB - Antiphospholipid antibodies (aPL) are a diverse family of autoantibodies reactive
against negatively charged phospholipid-protein complexes. The clinically
significant members include lupus anticoagulant (LA), anticardiolipin antibody
(aCL) and reaginic antibodies causing biological false positive (BFP) venereal
disease laboratory test (VDRL). Although detected in various clinical scenarios,
unexplained fetal loss in women of reproductive age group is the commonest
association. Fifty pregnant women of first and second trimester with a history of
two or more unexplained pregnancy losses were studied for the presence of LA, aCL
and reaginic antibodies. Thirty pregnant women of the same trimester without any
history of fetal loss were taken as control. LA was detected in nine (18%) cases
and aCL in 12 (24%) cases of the study group. The control group was negative for
any autoantibody. The prevalence of aPL in the study group found to be
statistically significant. Detection of aPL must be considered in women with
previous pregnancies complicated by unexplained fetal wastage.
PMID- 10778559
TI - Paclitaxel-epirubicin in advanced breast cancer.
AB - Breast cancer remains a major cause of morbidity and early death in women
worldwide. Despite the responsiveness of advanced breast cancer to a number of
chemotherapeutic and hormonal agents, long term outcome remains poor. The
introduction of paclitaxel with a novel mechanism of action has kindled a ray of
hope. Combination of paclitaxel with anthracyclines are being tried, with varying
degree of success. Twenty patients with metastatic or locally advanced breast
cancer were treated with Paclitaxel (175 mg/m2) and Epirubicin (80 mg/m2)
administered sequentially. Each patient received 3 to 6 such cycles at 3 weekly
intervals. A response rate of 85% (95% Confidence Interval (CI) 69%-100%) was
observed in these patients with 25% (95% CI 6%-44%) achieving complete response.
A response rate of 100% was observed in the six patients with locally advanced
disease who had not received any chemotherapy earlier. Grade III neutropenia
occurred in 5 patients and was reversible in all the cases. This combination is
well tolerated. Its efficacy is being compared in a randomised trial with CAF
regime in advanced breast cancer in our center.
PMID- 10778560
TI - Mountain desert silicosis.
AB - OBJECTIVES: To evaluate the radiological miliary shadows in the high landers of a
Himalayan desert for the presence of silicosis. METHODS: Seventeen high landers
attending the Medicine OPD of a multi-speciality medical camp at Kaza in
Himalayas (height 12,500 feet above sea level) having radiological miliary
shadows were included in the study. A detailed life time work place history was
taken. In the laboratory workup their hemogram, repeat chest skiagram, peak
expiratory flow rate, urinalysis and electrocardiogram were undertaken. Their
localities were looked for the presence of industries particularly for silicosis
prone work place. The silica contents of upper strata of soil were estimated.
RESULTS: Silicosis--chronic simple variety was present in nine males and eight
females. The youngest person was 43 years of age and oldest person was of 65
years of age. There was no silicosis prone industry in their locality. Four had
taken repeated courses of anti-tubercular treatment in adequate doses for these
miliary shadows without any change in the radiological shadows. Three had
silicosis prone work history. Seven were smokers and two had hypertension. The
miliary shadows were 2-4 mm in size and hilar lymphadenopathy was in 11 and fine
calcification of lymph nodes in two. Peak expiratory flow rate was reduced. Upper
strata of soil had a silica content of 36.8 percent. CONCLUSION: Silicosis
developed in high landers of the Himalayas even without working in silicosis
prone work place. They were exposed to silica from the non-work place silica rich
environment.
PMID- 10778561
TI - Distribution of blood viscosity values and biochemical correlates in healthy
adults.
AB - OBJECTIVE: Increase in the viscosity of blood predict clinical manifestation of
atherothrombotic vascular disease. The clinical utility of viscosity measurements
in cardiovascular risk factor requires a reference value established from a
healthy disease free population. METHODS: Blood viscosity (based on empirical
Merill's formula), fibrinogen, haematocrit and lipid profile were measured in 100
fasting healthy nonsmoking adults (50 men, 50 women). RESULTS: The mean (+/- SD)
blood viscosity values were 0.030 +/- 0.015 dyne/cm2. Men had higher viscosity
values than women. Also, men had higher triglycerides, haematocrit as well as
fibrinogen as compared to women. CONCLUSION: This study provides reference values
for the blood viscosity, fibrinogen haematocrit and lipid profile. Viscosity
measurements may improve identification and risk stratification of patients at
high risk for atherothrombotic vascular disease and its complications.
PMID- 10778563
TI - Medical profession at cross roads.
PMID- 10778562
TI - Basal ganglia calcification.
AB - Basal ganglia calcification (BGC) is now being diagnosed with increasing
frequency with widespread application of computed tomography (CT) in clinical
practice and is no more considered a rarity. During the period 1987 to 1995, 42
patients were noted to have BGC and it constituted 0.93% of all CT scan of brain
carried out during the relevant period. These patients presented with diverse
neurological and endocrine disorders i.e., epilepsy (22 patients), mental
retardation (five patients), extra-pyramidal syndromes (five patients), abnormal
behaviour (three patients), stroke (two patients), raised intracranial tension
without localizing signs (one patient), following radiotherapy (one patient), and
with hypoparathyroidism (three patients). These patients were noted to have
variable degree of calcification in different parts of brain i.e., basal ganglia
(42 cases), cerebellum (12 cases) and cerebral cortex (nine cases). Family
history of a neurological disorder was available in five patients. This study
highlights the fact that calcification of basal ganglia and other parts of the
brain is often a nonspecific finding on CT scan and it may not be possible to
establish a clinicopathological correlation.
PMID- 10778564
TI - Pictorial CME.
PMID- 10778565
TI - Imaging strategies for evaluation of carotid artery disease.
PMID- 10778566
TI - Epidemiological studies in medical practice pose practical challenges in
developing countries--a situational analysis.
PMID- 10778567
TI - Trinucleotide repeat diseases.
PMID- 10778568
TI - Retrosternal abscess caused by Aspergillus fumigatus following coronary artery
bypass surgery.
PMID- 10778569
TI - Malignancy in rheumatoid arthritis--a report of two cases.
AB - The development of malignancy in the setting of pre-existing connective tissue
disease is well known. We report two cases of rheumatoid arthritis who developed
malignancy--multiple myeloma in one of them and carcinoma cervix in the other.
Case 1 was a 62 year old man, who developed multiple myeloma three years after
the onset of rheumatoid arthritis. Case 2 was a 61 year old female with history
of rheumatoid arthritis for two years and who developed carcinoma cervix.
PMID- 10778570
TI - Fatal rabies encephalitis despite post-exposure vaccination in a diabetic
patient: a need for use of rabies immune globulin in all post-exposure cases.
PMID- 10778571
TI - Stroke like presentation of Creutzfeldt Jakob disease: an unusual variant.
AB - Creutzfeldt-Jakob disease (CJD) is a degenerative process of the brain, induced
by novel infectious agent or prion, and is usually characterized by a rapidly
progressive dementia in association with myoclonus. However different patterns of
disease presentation have been identified. The authors describe three probable
cases of CJD. None of them had positive family history or any known modes of
iatrogenic transmission. Interestingly, all the cases presented like a stroke.
This is the first series of CJD cases from this part of country.
PMID- 10778572
TI - Pulmonary hamartoma in a patient with testicular seminoma.
PMID- 10778573
TI - Ehler-Danlos syndrome type VI variant presenting with recurrent respiratory
infections and responding to high dose vitamin C.
PMID- 10778574
TI - Metaphyseal chondrodysplasia.
PMID- 10778575
TI - Megaloblastic anemia and acute subdural haematoma.
PMID- 10778576
TI - Artesunate therapy in falciparum malaria--alone or in combination.
PMID- 10778577
TI - Trials on pralidoxime.
PMID- 10778579
TI - Angiotensin converting enzyme estimation in pyrexia of unknown origin with
bilateral hilar lymphadenopathy--an essential investigation.
PMID- 10778578
TI - Uncommon iatrogenic pneumothorax.
PMID- 10778580
TI - Adrenaline precipitated intracerebral hemorrhage.
PMID- 10778581
TI - Ankle jerk in myxoedema with hemiplegia.
PMID- 10778582
TI - Antiphospholipid (Hughes) syndrome and recurrent pregnancy loss.
PMID- 10778583
TI - A preliminary study of antiphospholipid antibodies in 50 cases of bad obstetric
history.
AB - The prevalence of the antiphospholipid antibodies in certain high risk groups
like bad obstetric history is higher than previously realized. A pilot study in
50 patients of bad obstetric history, for the presence of lupus anticoagulant and
anticardiolipin antibodies was carried out to establish an association between
the presence of the antiphospholipid antibodies and recurrent fetal wastage.
Lupus anticoagulant alone was positive in six patients (12%) and anticardiolipin
antibody alone was positive in 14 patients (28%), while both lupus anticoagulant
and anticardiolipin antibodies were positive in three patients (6%). Activated
partial thromboplastin time (aPTT) and prothrombin time (PT) were not
significantly prolonged. Platelet count was normal in all the patients. We
conclude that lupus anticoagulant as based on kaolin clotting time and
anticardiolipin antibodies are important tests to detect the etiology of fetal
wastage.
PMID- 10778584
TI - Preceding infection as a risk factor of stroke in the young.
AB - INTRODUCTION: The cause of stroke in the young remains unknown in 20-50% of the
patients. Infections preceding stroke have been recently recognised to be an
independent risk factor of stroke. MATERIAL AND METHODS: Sixty consecutive
patients aged 40 years or less presenting with ischaemic completed stroke are
taken up for the study. Patients with neurological deficit of less than 24 hours,
evidence of haemorrhage on CT scan, infection occurring after the onset of stroke
were excluded. Controls consisted of age and sex matched persons residing in the
same area. Both the groups were enquired about preceding fever and infections and
were examined for evidence of infections. Serum was examined for antibodies
against measles, herpes simplex, and Japanese B encephalitis viruses. Cultures
were put up from appropriate samples and CSF examined in patients only. RESULTS:
Evidence of infection was noted in 26 (43.3%) of patients and 6 controls (p <
0.001). History of fever was elicited in 23 patients and 3 controls while 15
patients were febrile on examination at admission. Signs of local infection was
observed in 14 patients and one control. The commonest site of infection was
respiratory tract. Cultures were positive in 11 patients, commonest being beta
haemolytic streptococci in six from throat. Conventional risk factors were
identical in both groups of patients with and without evidence of preceding
infection. Smoking and alcoholism were significantly higher in patients with
preceding infection. CONCLUSION: Preceding infection is an important risk factor
of stroke in the young. Smoking and alcoholism are more frequent in patients with
preceding infection. Whether they predispose the individual for infection or
infection increases the stroke risk in them needs to be examined.
PMID- 10778585
TI - A study of lipid peroxide and alpha tocopherol in acute myocardial infarction.
AB - Thirty patients of acute myocardial infarction proven by electrocardiography
(ECG) and enzymes were included in the study. All of them received streptokinase.
A single lead showing the largest ST elevation, a proportional value for the
shift in ST segment > or = 0.5 was taken as criteria for reperfusion. ECG was
recorded at 0 hour, 3 hours and 72 hours. At the start of streptokinase and 3
hours after, marker of free radical activity malondialdehyde (MDA) and
antioxidant alpha tocopherol was measured. Mean value of serum alpha tocopherol
level at start of streptokinase (t0) 10.03 +/- 2.5 micrograms/ml and at (t3) 3
hours after streptokinase was 8.60 +/- 2.6 micrograms/ml (P < 0.001) and mean
value of serum lipid peroxidation level was 6.86 +/- 2.92 nanomol/ml at t(o) and
at t3 value was 8.4 +/- 3.88 (P < 0.012) in successfully reperfused patients. In
unsuccessful reperfusion group serum alpha tocopherol level at t(o) was 8.89 +/-
2.55 micrograms/ml and at t3 8.23 +/- 2.9 micrograms/ml (p > 0.05). Serum lipid
peroxidation level in the same group at t0 was 6.53 +/- 2.26 nanomol/ml and at t3
was 6.29 +/- 2.27 nanomol/ml (p > 0.05). The increase in free radical marker MDA
and decrease in one of the important antioxidant alpha tocopherol suggest that
free radicals are increased after coronary vessels open up. As a result
reperfused patients may be at risk of free radical mediated injury which may deny
him the full benefit of reperfusion.
PMID- 10778586
TI - Toxoplasmic encephalitis in acquired immunodeficiency syndrome.
AB - OBJECTIVES: To study the clinical course and outcome of toxoplasmic encephalitis
(TE) in patients with acquired immunodeficiency syndrome (AIDS). METHODS:
Patients infected with human immunodeficiency virus (HIV) and neurological
abnormality compatible with diagnosis of TE were enrolled in the study. These
patients were treated with combination of trimethoprim/sulfamethoxazole and
pyrimethamine. Response to therapy was assessed by clinical examination and
repeat CT/MRI scan done after three weeks of starting treatment. Those showing
response were put on prophylactic therapy. RESULTS: A total of 451 patients of
HIV infections were admitted to this centre during the study period, of these 11
patients were diagnosed to have TE. The common presenting symptoms were fever
(80%), seizures (45%), headache (45%) and altered sensorium (25%). Focal
neurological deficit was present in 80% of cases. Nine cases had ring-enhancing
lesions on CT scan while in the remaining two patient's ring lesions were seen on
MRI. These were either multiple (55%) or solitary (45%). Antitoxoplasma antibody
was detected in 10 patients. It was absent in one patient. Ten patients had
clinical and radiological improvement with trimethoprim/sulfamethoxazole and
pyrimethamine within 10 +/- 3 days of starting therapy. One patient died within
10 days of starting therapy. CONCLUSION: Toxoplasmosis is a common opportunistic
infection of the central nervous system in patients with AIDS. Majority of
patients with cerebral toxoplasmosis present with focal neurological abnormality
in presence of characteristic neuroradiological abnormality and positive
antitoxoplasma antibody titer. Response to empirical therapy helps to confirm the
diagnosis, lifelong prophylaxis there after prevents relapse of potentially fatal
and easily treatable condition.
PMID- 10778588
TI - Hypochromic anaemia in chronic renal failure--role of aluminium.
AB - BACKGROUND: Anaemia is a cardinal feature of chronic renal failure and
classically it is normochromic normocytic. Hypochromic anaemia in these patients
is often attributed to iron deficiency. AIM: This study was aimed to find the
contribution of aluminium in causation of anaemia in CRF patients. METHODS:
Dialysis dependent patients of chronic renal failure with adequate dietary intake
(> 1500 Cals/day) and no apparent source of blood loss were evaluated for type of
anaemia. (During period of this study centre didn't have reverse osmosis plant
for water treatment). Evaluation included upper GI endoscopy, complete hemogram,
serum proteins, serum iron, total iron binding capacity, and bone marrow iron
status. For aluminium evaluation serum aluminium levels were done. RESULTS: Sixty
four patients were evaluated for type of anaemia. Mean age of patients was 41.19
years (15-76 years) with male:female ratio 2.3:1. Classical normochromic picture
was seen in 28.5% while rest had hypochromic picture. On bone marrow aspiration
study two patients had zero iron stores while all others had normal/excessive
iron stores. In 10 patients with hypochromic picture, mean serum aluminium levels
were 170 micrograms/L (30-310 micrograms/L). CONCLUSIONS: This study highlights
the high prevalence of hypochromic anaemia in patients with adequate dietary
intake and aluminium overload in Indian CRF patients.
PMID- 10778587
TI - Safety and efficacy of Hartone in stable angina pectoris--an open comparative
trial.
AB - OBJECTIVES: To evaluate the safety and efficacy of 'Hartone'--a proprietary
herbal product primarily containing Terminalia arjuna in stable angina pectoris
patients. PATIENTS AND METHODS: Ten patients with stable angina pectoris were
given Hartone 2 caps twice daily for 6 weeks and 1 cap twice daily for the next 6
weeks. Haematological and biochemical investigations to assess safety were
carried out on day 0, day 42 and day 84. Serum lipid profile was done before and
after therapy. Efficacy was assessed by considering the reduction in the number
of anginal episodes and improvement in stress test. The results were compared
with 10 patients of stable angina pectoris on isosorbide mononitrate (ISMN) 20 mg
twice daily. RESULTS: Hartone afforded symptomatic relief in 80% of patients and
ISMN in 70%. The number of anginal attacks were reduced from 79/wk to 24/wk by
Hartone and from 26/wk to 7/wk by ISMN. Although patients of both groups showed
improvement in several stress test parameters compared to base line, the
difference was not statistically significant. Hartone improved BP response to
stress test in two patients and ejection fraction in one. Hartone was better
tolerated than ISMN and showed no evidence of hepatic or renal impairment. Its
effects on lipid profile was not consistent. CONCLUSION: Hartone is a safe and
effective anti-anginal agent comparable to ISMN and is better tolerated. Large
scale, randomised, double blind trials are needed to prove its efficacy.
PMID- 10778589
TI - Botulinum toxin in the treatment of writer's cramp.
AB - BACKGROUND: Writer's cramp is a task specific focal dystonia. The treatment of
writer's cramp is very disappointing. AIM: Study the effect of botulinum toxin
(BTX) in the treatment of writer's cramp. MATERIAL AND METHODS: Sixteen patients
of writer's cramp (15 men, 1 woman) with mean age of 35.75 years and mean
duration of symptoms for 3.64 years received 22 treatment sessions of botulinum
toxin-A (BTX). All patients were evaluated before, 3 and 12 weeks after BTX
therapy on a rating scale from 0-4 for ease of writing, abnormal posture and pain
(0 = normal, 4 = very severe disability). The speed of writing was also recorded
before and 3 and 12 weeks after therapy. Each patient also gave a global
subjective assessment 12 weeks after BTX therapy. RESULTS: Follow up was
available after 19 treatment sessions. Significant improvement was seen in all
the parameters studied i.e. abnormal posture (p = 0.0039), pain (p = 0.0092),
ease of writing of (p = 0.0025) and speed of writing (p = 0.0025). An improvement
of 50% or more was observed after 13 treatment sessions. Asymptomatic weakness in
the injected limb was seen in all patients but four patients complained of
weakness of fingers. The mean onset of improvement was 10.68 +/- 4.32 days and
mean duration of effect was 9.47 +/- 5.34 weeks. CONCLUSION: BTX is effective in
the treatment of writer's cramp. The draw-backs are short duration of action and
prohibitive cost.
PMID- 10778590
TI - Comparison of absorption rate and bioavailability of two brands of carbamazepine.
AB - OBJECTIVE: To assess the bioavailability of carbamazepine from two brands of
carbamazepine--Tegretol 200 and Zen-200. METHODS: A two-way randomised cross-over
bioavailability of carbamazepine was carried out in twelve healthy male
volunteers. Coded plasma samples were analysed for levels of carbamazepine by
high performance liquid chromatography (HPLC) method. Tegretol 200 and Zen-200
were tested for in-vitro dissolution profiles. RESULTS: The mean Cmax, Tmax and
t1/2a for Tegretol 200 were: 2.17 +/- 0.42 mcg/mL, 11.67 +/- 6.37 h and 2.72 +/-
1.87 h; for Zen-200 were 3.10 +/- 0.05 mcg/mL, 3.50 +/- 2.11 h and 0.76 +/- 0.76
h respectively. These values were statistically significant. However AUC (0-96 h)
value of 150.16 +/- 27.13 mcg/ml.h after Zen-200 was not statistically
significant as compared to 128.68 +/- 20.22 mcg/ml.h after Tegretol 200. The in
vitro dissolution profiles of the two formulations were dissimilar. The
fluctuations in CBZ levels after Tegretol 200 was significantly less as compared
to Zen-200. The absorption profile as judged by parameter 'A' was 50.44 +/- 10.95
for Tegretol 200 and 42.49 +/- 18.89 for Zen-200. CONCLUSION: Based on parameter
'A' and other pharmacokinetic parameters, the marketed generic carbamazepine
product, Zen-200 is not bioequivalent to Tegretol 200.
PMID- 10778591
TI - Serum vitamin E levels in patients of chronic myeloid leukaemia.
AB - OBJECTIVE: To estimate vitamin E levels in sera of patients of chronic myeloid
leukaemia (CML) before and after treatment with busulphan and hydroxyurea and to
compare the levels with those in healthy controls. METHODS: The study was carried
out in a total of 50 subjects (mean age 34 +/- 8.86 years; 25 were proved cases
of CML and 25 were healthy controls. Vitamin E level was measured by
spectrofluorometeric method. In patients of CML vitamin E level was estimated
twice i.e. once when their total leucocyte count (TLC) was raised (i.e. before
treatment) and then after treatment after bringing the TLC near normal. RESULTS:
The mean serum vitamin E level in 25 normal healthy controls was 7.19
micrograms/ml and that in 25 patients of CML at presentation (before treatment)
was 2.67 micrograms/ml. It increased to 3.61 micrograms/ml after treatment.
CONCLUSION: The results show that patients of CML have a significantly lower (p <
0.001) level of serum vitamin E as compared to normal healthy adults and that the
level of vitamin E increased significantly (p < 0.001) after treatment even
without supplementing vitamin E.
PMID- 10778593
TI - Clinical profile of ethylene Di-bromide (EDB; 1,2 dibromo ethane) poisoning.
PMID- 10778592
TI - Insulin resistance and urinary excretion of sodium in hypertensive patients with
non-insulin dependent diabetes mellitus.
AB - BACKGROUND: Hyperinsulinemia has been implicated in the pathogenesis of
hypertension both in non-diabetic and diabetic patients. A causal relationship
between renal sodium retention and hyperinsulinemia is speculated to play role in
the development of hypertension in diabetes mellitus. MATERIAL AND METHODS:
Twenty patients (12 males; 8 females) with hypertension and non-insulin dependent
diabetes mellitus (NIDDM) and twenty normotensive patients (11 males, 9 females)
with NIDDM were included in the present study. Blood samples for glucose and
immunoreactive insulin (IRI) assay were collected at 0, 30, 60 and 120 minutes
after 75 g of glucose per oral. Urinary sodium excretion in 24 hrs was estimated
by flame photometry. Insulin response to glucose and correlation between basal
insulin secretion and urinary sodium excretion were evaluated. RESULTS: Mean
fasting plasma glucose value was significantly raised in hypertensive group in
comparison with normotensive group of diabetic patients. Patients with diabetes
and hypertension and significantly higher level of serum IRI than normotensive
patients with diabetes mellitus. Urinary sodium excretion was significantly lower
in diabetic patients with hypertension than in diabetic patients without
hypertension. A negative correlation between basal insulin level and urinary Na+
excretion was observed in hypertensive patients with NIDDM. CONCLUSION: A
negative correlation between hyperinsulinemia and 24 hrs urinary Na+ excretion
was observed in patients with diabetes and hypertension. The study highlights
that patients with diabetes mellitus have tendency to retain sodium under the
influence of insulin but this needs further evaluation.
PMID- 10778594
TI - Drug-related problems and adverse drug events: negligence, litigation and
prevention.
AB - Since the inclusion of medical profession under Consumer Protection Act, Indian
doctors are facing malpractice suits. The incidence of adverse events (AEs) is
3.4-3.7, of adverse drug events (ADEs) is 2.4-6.5 and of adverse drug reactions
(ADRs) is 6.7 per 100 hospital admissions. The complications of drug-related
problems (DRPs) include therapeutic failure (TF) in 23% and new medical problems
(NMPs) in 10% and could lead to serious permanent disability and death in
majority (42%). The incidence of negligence in serious ADEs and death is 34% and
51%, respectively. Proportion of preventable ADEs is 28-50%. Errors occur most
often in prescribing (39-56%) and result in malpractice claims in 13-25% of
cases. Rational prescribing, improved therapeutic knowledge through re-training
and effective use of computers in prescribing could prevent errors and reduce
economic consequences for patients, doctors and hospitals.
PMID- 10778595
TI - Hepatitis G virus: an innocent contaminant.
PMID- 10778596
TI - Severe hyponatremia in a chronic schizophrenic patient.
PMID- 10778597
TI - Cortical blindness in acute intermittent porphyria.
PMID- 10778598
TI - Profuse variceal hemorrhage as a presenting feature of pancreatic adenocarcinoma
in a young non-icteric patient.
AB - Pancreatic adenocarcinoma can present with a vast spectrum of rare
manifestations. It usually occurs after the age of 50 years, the peak incidence
being in sixth and seventh decades. We report a previously asymptomatic subject
of pancreatic adenocarcinoma who presented for the first time with massive upper
gastrointestinal hemorrhage. Endoscopy revealed ruptured esophageal varices which
were secondary to tumour-induced thrombosis of the portal vein. Besides the
uncommon mode of presentation, the patient was unusual because of his young age.
Further, he was non-icteric at the time of presentation and remained so
throughout the clinical course despite having a large lesion in the head of the
pancreas.
PMID- 10778599
TI - Symmetric peripheral gangrene and falciparum malaria--an interesting association.
AB - Symmetric peripheral gangrene (SPG) is a rare syndrome in which disseminated
intravascular coagulation (DIC) is the most common underlying condition. We
report three cases of SPG in association with Plasmodium falciparum malaria and
DIC, an association unreported so far.
PMID- 10778600
TI - Hepatitis A and acute pancreatitis.
AB - Acute pancreatitis in association with acute viral hepatitis A in uncommon. We
present the case of a young girl with acute pancreatitis complicating acute viral
hepatitis A. The finding of IgM anti-HAV and exclusion of a vast array of other
etiologies implicates hepatitis A the cause.
PMID- 10778601
TI - Cutaneous vasculitis in a patient with primary Sjogren's syndrome.
AB - Sjogren's syndrome (SS) is an uncommonly described disorder from India. In this
report we describe a patient with SS and who developed cutaneous vasculitis.
PMID- 10778602
TI - Tuberculosis: a rare cause of splenic abscess.
AB - Splenic abscess is a rare condition associated with septicemic conditions.
Splenic abscess due to tuberculosis is still rarer, mostly diagnosed in immuno
compromised hosts. A case of tubercular splenic abscess without any underlying
disease is reported.
PMID- 10778603
TI - Percutaneous drainage of mediastinal abscess following oesophageal perforation.
PMID- 10778604
TI - Reciprocal ST segment changes in acute pancreatitis simulating acute myocardial
infarction.
PMID- 10778605
TI - Acute cerebellar ataxia following herpes zoster ophthalmicus.
PMID- 10778606
TI - Cyclosporine as a cause of unilateral gynecomastia in renal transplant recipient.
PMID- 10778607
TI - High dose cyclophosphamide in the treatment of systemic lupus erythematosus.
PMID- 10778608
TI - Clinical profile of AIDS: a study at a referral hospital.
PMID- 10778609
TI - Tuberculosis in patients with systemic lupus erythematosus.
PMID- 10778610
TI - Tuberculosis in patients with systemic lupus erythematosus.
PMID- 10778611
TI - Sparfloxacin in tuberculosis.
PMID- 10778612
TI - Sparfloxacin in mycobacterial infections.
PMID- 10778613
TI - Treatment of tuberculosis--role of sparfloxacin?
PMID- 10778614
TI - Objective Structural Clinical Examination.
PMID- 10778615
TI - Comparison of bioavailability of two brands of rifampicin.
PMID- 10778616
TI - Diet, activity and diabetes.
PMID- 10778617
TI - Influence of life style factors in development of diabetes in Indians--scope for
primary prevention.
AB - OBJECTIVE: The objective of the study was to evaluate the influence of physical
activity and stress factors on the development of diabetes mellitus (DM).
METHODS: One hundred and eighty-seven adult subjects (M:F 112:75), registered in
the primary prevention of diabetes programme for 2 or more years were studied
prospectively. The study was done only in those who had either normal glucose
tolerance (NGT) or diabetes at the time of review (tR). At entry (tE), 121
(64.7%) had normal glucose tolerance (NGT) and 66 (34.3%) had impaired glucose
tolerance (IGT) by the WHO criteria. Dietary modifications and regular exercise
programme were advised. Dietary modifications and regular exercise programme were
advised. Study subjects were reviewed during August 1997 to October 1998. At
review (TR) none had known history of diabetes. At TR, the status of glucose
tolerance was assessed by oral GTT and influence of intervention measures and
evaluation of the role of physical and psychological stress on glucose tolerance
were assessed by a questionnaire method. RESULTS: At tR, 100 (53.5%) had NGT, and
87 (46.5%) had developed diabetes (DM). Adherence to exercise and other
preventive measures was poor in the DM compared to nondiabetic group (NGT) (P <
0.0012). They showed lower dietary adherence (P = 0.042) and scores on mental
stress was higher than in NGT group (P < 0.001). After controlling for age,
gender and the initial 2 h plasma glucose, non-adherence to exercise and high
scores of psychological stress showed strong association with diabetes.
CONCLUSION: In this study, significant and independent roles of physical
inactivity and psychological stress factors are demonstrated in the development
of diabetes.
PMID- 10778618
TI - Silent myocardial ischemia and cardiac autonomic neuropathy in diabetics.
AB - OBJECTIVE: To evaluate the association of silent myocardial ischemia (SMI) with
cardiac autonomic neuropathy in asymptomatic diabetic patients. MATERIAL AND
METHODS: Two hundred asymptomatic patients of diabetes mellitus were assessed for
evidence of cardiac autonomic neuropathy. Of these, 30 (15 males, 15 females;
mean age 44.7 +/- 8.8 years) were found to have cardiac autonomic neuropathy.
Thirty (30) age and sex matched diabetic patients (mean age 42.4 +/- 7.6 years)
who had no evidence autonomic neuropathy were included in the study as control
group. Both the groups of patients were evaluated for SMI by 24 hour ambulatory
electrocardiographic (ECG) monitoring. RESULTS: Incidence of SMI was
significantly higher in patients with autonomic neuropathy 12/30 (40%) compared
to those without 3/30 (10%) p < 0.001. Duration of diabetes was more (13 +/- 1.59
years) in patients with autonomic neuropathy compared to the control group (8.66
+/- 1.55 years) p < 0.001. Serum cholesterol and triglyceride levels were
significantly higher in patients with autonomic neuropathy in comparison to
control group < 0.05 and < 0.01, respectively. There was no difference in the
pattern of SMI in the two groups (p = N.S). CONCLUSION: Cardiac autonomic
neuropathy predisposes patients with diabetes mellitus to SMI. Twenty four hour
ambulatory ECG monitoring provides useful diagnostic information in early
detection and evaluation of SMI in asymptomatic diabetic patients.
PMID- 10778619
TI - Results of allogeneic bone marrow transplant in chronic myeloid leukaemia
following conditioning with busulfan and cyclophosphamide.
AB - OBJECTIVE: To study the outcome of oral busulfan and intravenous cyclophosphamide
(BuCY 2 regimen) followed by allogeneic bone marrow transplant (BMT) in a cohort
of patients with Philadelphia chromosome (Ph+) chronic myeloid leukaemia (CML) in
a single centre. METHODS: From 1991 to March 1998, a total of 27 consecutive Ph+
CML patients received busulfan 4 mg/kg/day over 4 days and cyclophosphamide 60
mg/kg/day over 2 days followed by infusion of HLA-identical sibling
haematopoietic stem cells. All except one (who received peripheral blood stem
cells) were given donor bone marrow cells. Post-transplant graft versus host
disease (GVHD) prophylaxis included a short course of methotrexate (on days +1,
+3, +6 and +11) and cyclosporine till day +180. RESULTS: With a median follow-up
of 30.5 months (1-55+ months), 14 patients (52%) are alive free from relapse.
Early mortality was relatively high with 10 patients (37%) dying within first 100
days post-transplant. Acute GVHD developed in 14 patients (52%) inspite of GVHD
prophylaxis with methotrexate and cyclosporine; six had grade I/II and eight
grade III/IV. Chronic GVHD developed in five of 15 patients who lived beyond 70
days. CONCLUSION: Allogeneic BMT appears to result in eradication of CML and
ensure disease free survival in about half of the young patients. However,
efforts should be on to minimise early mortality.
PMID- 10778620
TI - Mortality trends in falciparum malaria--effect of gender difference and
pregnancy.
AB - Falciparum malaria in pregnancy is a significant health problem in India.
Pregnant women constitute an important high risk group for malaria infection
which may cause abortions, stillbirths, intra-uterine growth retardation (IUGR)
and premature labour. In this hospital based study on 602 admitted patients of
falciparum malaria which included 314 males, 243 non-pregnant females and 45
pregnant females, there was significantly increased mortality rate in females
(18.4%) in comparison to males (7.64%, p < 0.001). The mortality rate was highly
significant in pregnant females (37.77%) in comparison to non-pregnant females
(14.81%) and males (7.64%; p < 0.001). Severe anaemia with Hb < 5 gm% was
observed more commonly in pregnant patients (20.0%) in comparison to non-pregnant
patients (4.11%). Incidence of malaria infection was more in primi gravida and
second gravida. Pregnancy related complications in the form of preterm live
births, intra-uterine death (IUD), still births and abortions were more in primi
parous than multiparous patients. As the pregnancy is associated with increased
incidence and adverse outcome of P.falciparum malaria infection, chemoprophylaxis
should be made an integral part of antenatal care along with antianaemia therapy
to reduce the risk of serious maternal and fetal complications.
PMID- 10778621
TI - Pulmonary infections after kidney transplantation.
AB - OBJECTIVE: To retrospectively analyse the epidemiology, aetiology, temporal
profile and outcome of lung infection following kidney transplantation. METHODS:
Out of 142 consecutive renal transplant (RT) recipients who underwent live donor
transplantation from June, 1990 to May, 1998, 43 (33%) had serious infection
requiring hospitalisation of which 27 were pulmonary. All such pneumonia were
included for retrospective analysis. All had a minimum follow up of six months
(if alive) and were on triple drug immunosuppression. All had detailed and
appropriate investigations for definitive diagnosis. RESULTS: The aetiological
agents were Gram negative bacterial infection (2), Gram positive bacterial
infection (1), nocardia (2), tuberculosis (10), aspergillosis (2), mixed
bacterial and fungal infection (4), Pneumocystis (2) and unconfirmed (4). Four
patients had pneumonia because of probable nosocomial exposure. Radiologically
lobar/segmental pneumonia was observed in five, nodular lesion six,
reticulonodular lesion eight, patchy consolidation five and pleural effusion
three. Nodular pneumonias were due to aspergillosis or nocardiosis. Four patients
developed secondary cavitation. Pulmonary infections were significantly
associated with leucopenia (8/27) (p < 0.01) but not with renal dysfunction
(creat > 2 mg%), diabetes, old age or additional immunosuppression (p > 0.05).
There were 11 deaths. Mortality was related to failure to reach diagnosis (3) and
delayed institution of therapy (6 patients). Pneumonia within first six months
had a higher mortality (9/16) compared to late pneumonia (2/11). Immunomodulating
virus (CMV 4, HEP B 2) was present in six patients of whom four succumbed.
CONCLUSION: Pulmonary infection is a common and serious post-transplant infection
requiring hospitalisation, is associated with high mortality. Patients with
leucopenia are predisposed to these infections. Prophylaxis for Pneumocystis,
Nocardia and tuberculosis needs strong consideration to reduce mortality of such
infection. Nosocomial exposure risk needs careful consideration in outbreaks of
opportunistic infection.
PMID- 10778622
TI - Effect of selegiline on cognitive functions in Parkinson's disease.
AB - BACKGROUND: Selegiline hydrochloride, a selective MAO-B inhibitor is known to
improve motor functions in Parkinson's disease (PD). The present study was
undertaken to study the effect of selegiline on memory and intelligence of PD
patients. MATERIAL AND METHOD: Thirty two patients of PD were divided in two
groups: selegiline group (n = 17) received 10 mg selegiline per day and control
group (n = 15) did not receive selegiline. Patients receiving trihexyphenidyl and
selegiline were excluded. All other treatment remained unchanged. All patients
were examined at baseline and after three months for change in UPDRS score, WAIS
score, memory test and P300. RESULTS: Patients in selegiline group had less
severe disease (UPDRS score 24.11 +/- 14.07) as compared to controls (UPDRS score
40.53 +/- 18.52). There was significant improvement in UPDRS score (p < 0.05),
WAIS (p < 0.001) and memory (p < 0.001) in selegiline group. In the control group
there was a significant prolongation of P300 latency (p < 0.05). CONCLUSION: The
study suggests that selegiline improves memory functions and intelligence in PD
patients in addition to motor functions. It also prevents prolongation of P300
latency which is a marker of cognitive function.
PMID- 10778623
TI - Diagnostic significance of immunoglobulins and adenosine deaminase in pleural
effusion.
AB - OBJECTIVES: 1) To evaluate the diagnostic significance of ELISA for detection of
antibodies to antigen A60 of Mycobacterium tuberculosis and adenosine deaminase
(ADA) in patients with pleural effusion without prior history of tuberculosis, 2)
To study the importance of the above tests in patients with HIV infection and
pleural effusion. METHOD: Eighty one patients with pleural effusion were studied.
In addition to diagnostic paracentesis and pleural biopsy, pleural fluid specific
IgG, IgM, IgA against antigen A60 and fluid ADA were estimated. HIV testing
(ELISA) was done in all patients. RESULTS: Out of 81 patients, 13 were HIV
positive. IgG anti A60 had a sensitivity and specificity of 90.71% and 33.33%
respectively. The combination of IgG and IgM had a sensitivity and specificity of
96.3% and 55.55% respectively. IgA alone or in combination did not offer any
diagnostic advantage. ADA had a sensitivity and specificity of 76% and 60%
respectively. In presence of HIV infection, antibodies against A60 had a
sensitivity of 76.92% and ADA had a sensitivity of 61.54%. CONCLUSIONS: In
patients with pleural effusion, immunoglobulins against antigen A60 have a
limited diagnostic role with high false positive rates. Co infection with HIV
further reduces the value of above diagnostic tests.
PMID- 10778624
TI - Profile of extrahepatic portal venous obstruction in Mumbai.
AB - AIM OF THE STUDY: To study the clinical profile of extrahepatic portal venous
obstruction (EHPVO) in a tertiary referral centre in Mumbai. METHODOLOGY:
Retrospective analysis of records of 113 patients with EHPVO, treated between
January 1984 and May 1996. RESULTS: Thirty eight of 54 (70.4%) patients in whom
information was available were delivered at home. Eleven of the 50 (22%) had
umbilical sepsis after birth. Median disease duration was 5 years (range 4 months
31 years), with age at initial presentation 13 (range 0.5-45) years; 24 (20%)
patients presented after age 20 years. Eleven presenting initially with
splenomegaly bled after 3 (1-14) years. Number of bleeding episodes per patient
was 2.5 (1-12). 13 of 44 (29.6%) patients bled (first bleed or recurrence) after
age 20 years. Twenty five (22.3%) had ascites at some time, 17/102 (16.7%) had
hypersplenism, and hypoalbuminaemia was present in 20/103 (19.2%). Endoscopic
sclerotherapy obliterated varices in 47/52 (90.4%) in 10.5 (3-40) sessions over 7
(1-100) months. Twenty three patients underwent surgery: devascularisation in 20
(with splenectomy in seven), distal lieno-renal shunt in two, and meso-caval
shunt in one patient. Follow-up was available in 68 (60.2%) patients. Rebleeding
after sclerotherapy occurred in 27/64 (42.2%), with median one (1-5) per patient;
recurrence of varices was noted in 15/35 (42.9%) patients over 12 (3-39) months.
Varices were present in 12 patients 163 (33-305) months after surgery.
CONCLUSIONS: Home delivery and umbilical sepsis may be risk factors in the
development of EHPVO. A significant number of patients present or continue to
bleed from varices after age 20. Variceal sclerotherapy is effective for
eradication of oesophageal varices.
PMID- 10778625
TI - Antibiotics sensitivity pattern of N. gonorrhoeae with special emphasis on
norfloxacin and ciprofloxacin.
AB - The current study is carried out to find the in-vitro susceptibility of N.
gonorrhoeae to Ciprofloxacin, Norfloxacin, Gentamycin etc. in 110 isolates
obtained from acute gonococcal urethritis confirmed by smear examination. The
isolates obtained are from the patients attending the Skin and STD Clinic of a
teaching hospital, clinically diagnosed as suffering from acute gonococcal
urethritis. Antibiotic susceptibility test was done by Kirby Bauer disc diffusion
technique. Four to five similar well isolated colonies of the gonococcal strains
were picked up with a wire loop and transferred to 5 cc of sterile trypticase
soya broth (TSB). Tubes were incubated at 36 degrees C. GC agar base plates were
inoculated with suspensions using a sterile cotton swab. Antibiotic discs were
placed on these plates. The plates were incubated at 35 degrees C for 18-24 hours
in a candle jar with 5-10% CO2. The plates were then observed to note the zones
of inhibition around the discs. 87.27% of isolated strains were inhibited by
norfloxacin at an MIC of 0.06 mu gm/ml; 89.08% of the strains were inhibited by
ciprofloxacin at an MIC of 0.025 mu gm/ml. All the strains (110) were inhibited
by ciprofloxacin at a concentration of 0.2 mu gm/ml. Gentamycin sensitivity was
86.36%. Out of 110 patients, 85 were treated with norfloxacin of which 81
(95.29%) were cured. Twenty five were treated with ciprofloxacin of which 24
(96%) were cured. This study shows high sensitivity of N. gonorrhoeae to
norfloxacin and ciprofloxacin.
PMID- 10778627
TI - Pictorial CME. Complex regional pain syndrome, type I.
PMID- 10778626
TI - Mega dose intravenous methylprednisolone in bilateral simultaneous optic
neuritis.
AB - OBJECTIVES: The study was carried out to assess the efficacy of megadose
intravenous methylprednisolone in patients of bilateral simultaneous optic
neuropathy (BSON) of unknown etiology. METHODS: Fifteen consecutive patients
admitted in neurology unit were included in the study. These patients were
subjected to various investigations including MRI and CSF exam to exclude all
known causes of optic neuropathy including multiple sclerosis. All patients were
put on single dose intravenous methylprednisolone, 1 gm/day in adults and 500
mg/day in children for three days. Pre and post-treatment visual parameters
including visual evoked potentials (VEP) were carried out. RESULTS: There was a
female preponderance and the average age was 28 years. The visual acuity and P100
latences of visual evoked potentials (VEP) improved in all cases. The improvement
was statistically significant (P < 0.001). CONCLUSION: Use of intravenous
methylprednisolone is a preferred drug in bilateral simultaneous optic neuropathy
(BSON) as compared to oral or retrobulbar steroids.
PMID- 10778628
TI - Isolated cerebral hydatid cysts: a comparative study of two different types of
presentations.
AB - OBJECTIVES: To demonstrate the existence of two imaging patterns of cerebral
hydatidosis and discuss its clinical importance. MATERIAL AND METHODS: A
retrospective review of six cases of cerebral hydatidosis using various imaging
techniques including CT, MRI, angiography and cystogram. RESULTS: Clinically the
most common findings included papilloedema, headache and vomiting. Two of the
cases reported recurrence of symptoms and were reoperated. The first 4 cases
presented the classical signs of unilocular well defined cysts while the last two
cases had multilocular, often polygonal cysts with perifocal edema, calcification
and membrane detachment. CONCLUSION: Two radiologically and pathologically
distinct subtypes of hydatidosis exist. Division into groups may assist decision
over treatment protocol.
PMID- 10778629
TI - Grudgitis.
PMID- 10778630
TI - Telemedicine: applications, barriers and medico-legal aspects.
PMID- 10778631
TI - C-reactive protein--marker for atherothrombotic events.
PMID- 10778632
TI - Tracheoesophageal fistula following prolonged mechanical ventilation.
PMID- 10778633
TI - Concurrent multidrug resistant Plasmodium falciparum from northeast India.
PMID- 10778634
TI - Coexistence of anomalous pancreaticobiliary ductal union with acalculous
cholecystitis.
PMID- 10778635
TI - Polyneuritis cranialis in a case of leprosy.
PMID- 10778637
TI - Mandibulo-acral dysplasia: Indian patient with severe bony changes.
AB - We report an Indian patient with mandibulo-acral dysplasia. This patient had
absence of spinous processes of 4th and 5th cervical vertebrae and very severe
bony changes but no loss of teeth.
PMID- 10778636
TI - Fatal paraquat poisoning: report of two cases.
AB - Paraquat, a dipyridium compound is widely used as a herbicide. It is available in
India as a liquid concentrate for agricultural use and is highly toxic if
ingested. It leads to renal, hepatic, cardiac and pulmonary toxicity and also
causes burns of oral mucosa and esophagus as it is caustic in nature. We describe
two cases of paraquat poisoning who developed serious toxicity following its
ingestion and died of respiratory failure.
PMID- 10778638
TI - Insulin dependent diabetes mellitus induced by chemotherapy and granulocyte,
macrophage--colony stimulating factor.
PMID- 10778639
TI - Stiff-man syndrome--diagnostic criteria and pitfalls.
PMID- 10778640
TI - Acute renal failure and hepatitis induced by intermittent rifampicin therapy.
PMID- 10778641
TI - Acute myocardial infarction presenting as masquerading bundle branch block.
PMID- 10778642
TI - Cefoperazone induced gastrointestinal haemorrhage.
PMID- 10778643
TI - Acrocephalosyndactyly--type I (Apert's syndrome).
PMID- 10778644
TI - Tuberculin sensitivity in HIV--seropositive patients.
PMID- 10778645
TI - Haematuria caused by oral typhoid vaccine.
PMID- 10778646
TI - The role of myoglobin in early detection of acute myocardial infarction.
PMID- 10778647
TI - Serum lipoprotein(a) levels in ischaemic heart disease.
PMID- 10778648
TI - Unusual and severe forms of adverse drug reactions.
PMID- 10778649
TI - The changed clinical spectrum of malaria due to drug resistance.
PMID- 10778650
TI - Scorpion sting.
PMID- 10778651
TI - Treatment and outcome of lupus nephritis at the turn of the millennium.
PMID- 10778652
TI - Prognostic factors in diffuse proliferative lupus nephritis.
AB - BACKGROUND: Patients with diffuse proliferative lupus nephritis (DPLN) can have
variable clinical course. Identification of the predictors of outcome would help
to improve the management. We have studied the prognostic significance of
clinical, laboratory and histological parameters in patients with DPLN. METHODS:
Twenty nine patients diagnosed to be having DPLN seen between 1987 and 1991 were
followed up for over 57 months. Parameters assessed for prognostic significance
included serum creatinine, urine protein at the time of biopsy, blood pressure,
type of immunosuppression, composite scores and individual components of activity
index (AI) and chronicity index (CI). Kaplan-Meier survival curves were plotted
and the results were compared using log rank test. Fishers' exact test was used
to study the risk factors. RESULTS: End stage renal failure developed in 7/29
(24.1%) patients; 7/19 (36.8%) who had hypertension and 7/16 (43.8%) who had
nephrotic proteinuria developed renal failure, while none who had normal blood
pressure or nonnephrotic proteinuria, developed renal failure (p < 0.01). Three
patients had high activity index (> 12) and all three developed renal failure.
Other parameters such as age, gender, serum creatinine, type of
immunosuppression, CI and individual components of AI failed to predict the
outcome (p > 0.05). CONCLUSION: Hypertension, nephrotic proteinuria and high AI
were predictive of progression to end stage renal failure in patients with
diffuse proliferative lupus nephritis.
PMID- 10778653
TI - Seroprevalence of IgG antibodies to Helicobacter pylori among gastrointestinal
endoscopists, radiologists and paramedical personnel.
AB - BACKGROUND: The route of transmission of Helicobacter pylori is unknown. Since
the organism has been isolated from saliva, gastric juice and stool, medical
personnel could be at high risk for acquiring the infection during procedures
like gastrointestinal endoscopy. AIMS: To study whether endoscopy is a
professional hazard for acquisition of H. pylori. METHODS: We studied the
prevalence of IgG antibodies to H. pylori in endoscopists (n = 17), radiologists
(n = 17) and personnel from paraclinical branches (n = 35); microbiology (n =
21), pathology (n = 7) and forensic medicine (n = 7); among the paraclinical
personnel five were at high risk because they worked with cultures of H. pylori.
Subjects answered a questionnaire regarding upper gastrointestinal symptoms, and
precautions taken at the work place against infection. The serum was tested for
IgG antibodies to H. pylori using a microwell ELISA and a rapid card test.
RESULTS: H. pylori antibodies were present in five (29.4%) endoscopists, three
(17.6%) radiologists and seven (20%) paraclinical personnel; only one of the 5
high risk para medical personnel was positive. There was no correlation between
the duration of performing endoscopies and the H. pylori IgG status. CONCLUSION:
Endoscopy is not a risk factor for acquiring H. pylori infection.
PMID- 10778654
TI - Effect of protein and phosphate restricted and calcium and alphacalcidol
supplemented diet on renal and parathyroid functions and protein status in
chronic renal failure patients.
AB - OBJECTIVE: To assess the effect of low protein (0.6 g/kg/day), low phosphate (5
10 mg/kg/day) diet with calcium (600 mg/day) and alpha-D3 (0.5 microgram/day)
supplementation on renal and parathyroid functions in patients with chronic renal
failure (CRF). METHODS: The study included 20 adult patients of CRF, maintained
on diet therapy alone. The patients were followed up for renal and parathyroid
functions and protein status for 6 months at monthly interval. RESULTS: There was
symptomatic improvement in 88% patients. Blood urea and serum creatinine
decreased significantly (p < 0.001 and < 0.01, respectively) and the slope of
inverse serum creatinine against time changed to static or an upslope. Glomerular
filtration rate (GFR) improved from a basal value of 29.35 +/- 18.2 ml/min to
39.25 +/- 27 ml/min after 6 months. Serum parathyroid hormone (PTH) level of
197.65 +/- 133.7 pg/ml and post treatment level of 254.55 +/- 217.19 after 6
months were not different (p > 0.05). Serum calcium remained stationary with a
slight increase in serum phosphorus. Phosphorus had a negative correlation with
calcium and GFR, whereas calcium had a negative correlation with PTH and
phosphorus. PTH had a positive correlation with phosphorus and negative with GFR
and calcium. CONCLUSION: There was an improvement in renal functions without any
deleterious effect on the protein status of the patients of CRF. Also, there was
halting of parathyroid dysfunction especially in those patients where there was
no evidence of pre-existing hyperparathyroidism. Hence, dietry management should
be strictly enforced in CRF patients early in the course of disease.
PMID- 10778655
TI - Hypohaptoglobinaemia as a biochemical and epidemiological marker of falciparum
malaria.
AB - OBJECTIVES: The study was conducted in two parts to find out the usefulness of
hypohaptoglobinemia (Hpo) as a biochemical and epidemiological marker of malaria.
Part-I study was conducted in a Medical College Hospital to find out Hpo in
malaria and the time required for normalization of Hpo. Part-II study was
undertaken in two endemic areas of malaria to find out the prevalence of Hpo and
haptoglobin index (HI) throughout the year along with other indicators of
malaria. METHODS: In Part-I study, 172 patients of malaria constituting 58, 52
and 62 patients of cerebral malaria, uncomplicated falciparum malaria and vivax
malaria, respectively were enrolled. Along with routine haematological and
biochemical investigations, haptoglobin (Hp) estimation was done by endoplate
haptoglobin test kit on admission and at 15 days interval for 3 months. In Part
II study Hp was estimated is 305 subjects in two endemic areas of malaria. HI,
parasitic index, slide positivity rate (SPR), slide falciparum rate (SFR) were
estimated throughout the year and HI was compared with these epidemiological
markers. RESULTS: Hpo was present in 102 (92.7%) cases of falciparum malaria
which was significantly more than vivax malaria and non-malarial fever. The
normalisation of Hpo took about a month or more. The incidence of Hpo was 32.1%
is endemic and 4.7% in nonendemic area of malaria. The HI varied between 12.4 to
25.2% throughout the year and was found to be a better marker than other
classical markers of malaria. CONCLUSION: Hypohaptoglobinemia may be considered
as a useful indirect indicator of falciparum malaria. HI can be used as an
epidemiological maker which is better than classical markers of malaria used at
present.
PMID- 10778656
TI - Comparative study of platelet histamine and serotonin with their corresponding
plasma oxidases in asthmatics with normals.
AB - OBJECTIVE: Asthma is well controllable but non-curable disease. Exact
pathophysiology involved is unresolved till today. Role of allergic
hypersensitivity reaction in asthmatic on-set is well established. Present work
is an effort to elucidate some basic points of unresolved pathophysiology of
asthma taking platelets as marker. MATERIAL AND METHODS: A group of 52 normal
human subjects in the age group of 20-60 years were studied for platelet
histamine and serotonin levels and also for their plasma metabolising enzymes
diamine oxidase (DAO) and monoamine oxidase (MAO). The data was collected for 79
asthmatic patients at different stages of asthma and accordingly were studied as
four different groups of seventy nine asthmatics those were on regular treatment
and were comfortable with drugs and were free from symptomatic attack formed gr.
I; these (79) patients were followed-up during their symptomatic phase (gr. II)
and same (79) patients immediately after their recovery from symptomatic stage
studied as gr. III members. All the 79 asthmatic patients fall in gr. I, II and
III in a serial manner i.e. all (n = 79) in each group. A separate group of
thirty seven patients with known history of asthma but were symptom free and also
off drugs for last 2-4 years formed gr. IV. RESULTS: Results showed mean platelet
count in asthmatics at all four stages were in the normal range but were slightly
low in comparison with normals. Both the enzymatic levels (DAO and MAO) in gr. I,
II and III were significantly higher than normals but were same in the case of
gr. IV patients. Low levels of platelet biogenic amines were observed in
asthmatics (gr. I to gr. IV) than normals. CONCLUSIONS: Thus, study parameters
showed significant difference in asthmatics and normals. Findings of the study
have been utilized to understand unanswered hypersensitivity shown by the
asthmatics over normal individuals (non-asthmatics).
PMID- 10778657
TI - An open study to evaluate the efficacy of artemether in severe falciparum
malaria.
AB - An open clinical trial was conducted in 30 patients of severe falciparum malaria
with heavy parasitaemia (parasitized erythrocytes above 5%). Artemether (methyl
ether of dihydroartemisinin-active principle isolated from Chinese plant
Qinghaosu) was administered as 80 mg intramuscular injection twice on first day
and then single dose of 80 mg intramuscular on 2nd to 5th day. The trial could be
completed in 28 patients and two patients expired. In our observation falciparum
malaria affected the young adults in their most productive period of life i.e. 25
44 yrs. All patients became afebrile by the 4th day with fever clearance time
approximately 31.92 +/- 15.30 hr. Twenty-five patients (83.33%) became parasite
free by 5th day with mean parasite clearance time approximately 47.04 +/- 19.95
hr. Deranged liver function and renal profile was observed in 63% and 50%
patients respectively. Two patients, who died had very high degree of
parasitaemia (50% and 16%) with cerebral malaria. One died due to multiorgan
failure and other due to massive hematemesis and shock. The type of response
achieved by artemether therapy was analysed as per WHO criteria suggested for
chloroquine resistance. S response was observed in 25 patients (cure rate
83.33%). Two patients (6.66%) patients showed R II response, one patient (3.33%)
showed R III response and R I response was not observed in any patient. No
significant side effects were noted. This pilot study demonstrated that
intramuscular artemether is a useful addition to antimalarial drugs in this era
of multidrug resistant P. falciparum malaria showing high clinical potency with
virtually no side effect.
PMID- 10778659
TI - Splenectomy in sickle cell disease.
AB - INTRODUCTION: Since role of splenectomy in sickle cell disease still remains
controversial, this paper evaluates the same in 32 cases of splenectomy in sickle
disease patients observed by the author. MATERIAL AND METHODS: After proper
diagnosis by standard methods the cases were observed for 2-3 years before
deciding on splenectomy. Though acute splenic sequestration (53%) and chronic
hypersplenism (21.8%) were the main indication. Two cases of splenic abscess and
one case with frequent pain attacks were also subjected to splenectomy. There was
one immediate post-operative death. RESULTS: The cases were followed up for 1 to
> 8 years. While Acute splenic sequestration disappeared, in chronic
hypersplenism cases as well as others besides a sense of general well being,
steady state hemoglobin rose by > 2G/dl in 81% and significant increase in height
and weight was seen in 90% and 61% cases respectively. Frequency of pain attack,
fever, anaemia and need for blood transfusion improved in 79% patients.
CONCLUSION: Splenectomy in selected cases appears to be an acceptable procedure
in sickle disease.
PMID- 10778658
TI - Comparative bioavailability study of a conventional and two controlled release
oral formulations of Tegretol (carbamazepine)--200 mg.
AB - OBJECTIVES: To assess the bioquivalence of carbamazepine (CBZ) controlled release
formulation A (Tegretol CR, local) vs formulation B (Tegretol CR, Basel) and
confirm their controlled release characteristics by comparing with conventional
formulation (Tegretol). METHODS: A three-way randomized cross-over
bioavailability study was carried out using CBZ 200 mg tablets of conventional
and two controlled release formulations in twelve healthy volunteers. Coded
plasma samples were analysed for levels of CBZ by HPLC method. RESULTS: The mean
Cmax, Tmax, t1/2 and AUC for formulation A were: 1.67 +/- 0.26 mcg/mL, 24 +/- 0
hr, 47.8 +/- 9.7 hr and 136.7 +/- 25.4 mcg/ml. h; for formulation B were 1.41 +/-
0.31 mcg/mL, 25 +/- 8 hr, 46.9 +/- 7.9 and 119 +/- 32.3 mcg/ml.h and for
conventional formulation were 2.43 +/- 3.6 mcg/mL, 9.5 +/- 7.4 hr, 44.6 +/- 9.8
hr and 178.8 +/- 41.9 mcg/ml.h respectively. The fluctuation in plasma
concentration within 24 h (peak:trough) were 11.7 +/- 8.14% with conventional
formulation as compared to 0% and 1.2 +/- 3.98% with formulation A and B
respectively. The mean Tmax for both the controlled release formulations was not
statistically significant. On the basis of 90% confidence interval, mean AUC and
Cmax values obtained after controlled release formulation A, though statistically
significant (P < 0.05) lie well within the prescribed limits of 80-120% as
compared to formulation B. Thus both the controlled release formulations were
bioequivalent. In comparison to conventional formulation, both controlled release
formulations gave lower Cmax, lower AUCs, higher Tmax values, less fluctuation in
CBZ plasma concentrations, reduction in ratio of Cmax/AUC values, thus
demonstrating controlled release characteristics of the formulation. CONCLUSIONS:
Based on the above mentioned parameters both controlled release formulations are
bioequivalent and demonstrate controlled release characteristics.
PMID- 10778660
TI - Surrogate endpoints: do they really contribute in therapeutic decision making?
AB - Surrogate endpoints are substitutes for the true endpoints and measured in any
clinical research to relate in some way to the outcome of primary interest.
Inappropriate selection of surrogate markers may lead to controversies during
clinical trials or therapeutic interventions. Use of surrogate markers depends
upon thorough understanding of the pathophysiology of the disease and
pharmacology of drugs. Results obtained with surrogates should be regarded as
preliminary and necessitates definitive studies.
PMID- 10778661
TI - Pictorial CME. Pulmonary Cryptococcus neoformans infection.
PMID- 10778663
TI - Essential fatty acids in health and disease.
AB - Essential fatty acids (EFAs) form an important component of cell membranes, are
eicosanoid precursors and are therefore required for both the structure and
function of every cell in the body. EFAs can modulate the activity of protein
kinase C, T and B cell response, free radical generation and lipid peroxidation,
lymphokine secretion and cell proliferation. EFAs also have anti-mutagenic, anti
bacterial, anti-fungal and anti-viral properties. EFAs and their metabolites
lower serum cholesterol, triglycerides and blood pressure. EFAs appear to be of
benefit in atopic eczema, premenstrual syndrome, psoriasis, auto-immune disorders
especially rheumatoid arthritis and systemic lupus erythematosus, prevention of
target organ damage in diabetes mellitus, peptic ulcer disease, ulcerative
colitis, coronary heart disease and atherosclerosis. EFAs and their metabolites
can selectively kill tumor cells both in vitro and in vivo without harming normal
cells. In addition, EFAs seem to play a fundamental role in inflammation and
immune response. In view of their actions and relative safety, it is anticipated
that EFAs may be useful in the management of several diseases.
PMID- 10778664
TI - Recent advances in drug therapy for rheumatoid arthritis.
PMID- 10778662
TI - Oxygen therapy.
PMID- 10778665
TI - Postoperative endocarditis due to Candida tropicalis.
AB - In conclusion, we emphasize the importance of isolating the fungal agent from
repeated blood cultures, particularly in infective endocarditis following heart
surgeries.
PMID- 10778666
TI - Ileo-ileo-colic intussusception secondary to an ileal lipoma.
AB - Adult intussusception is extremely uncommon and constitutes approximately 5-16%
of all intussusceptions. We describe a case of ileo-ileo-colic intussusception
secondary to an ileal lipoma occurring in a 22 year old man who in addition had
autosomal dominant polycystic kidney disease. CT scan played a pivotal role in
not only demonstrating the cause of intestinal obstruction (intussusception) but
also showed that a lipoma was the lead point precipitating the intussusception.
PMID- 10778667
TI - Coronary arterial fistula in association with rheumatic heart disease.
PMID- 10778668
TI - Idiopathic hypoparathyroidism with extensive intracranial calcification
associated with kinesigenic choreoathetosis.
PMID- 10778669
TI - Post-vaccinal diffuse myelitis: magnetic resonance imaging features.
PMID- 10778670
TI - Tuberculous peritonitis: an uncommon presentation.
PMID- 10778671
TI - Cryptococcal meningitis in immunocompetent individuals.
PMID- 10778672
TI - Transient ischaemic attack caused by a small basal ganglia haematoma.
PMID- 10778673
TI - Spontaneous acute thymic hemorrhage in a patient with aplastic anemia.
PMID- 10778674
TI - Diabetes mellitus: an uncommon manifestation of pancreatic tuberculosis.
PMID- 10778675
TI - Cervical myelopathy due to fluorosis in non-endemic area of Vidarbha.
PMID- 10778676
TI - Colonic tuberculosis mimicking ulcerative colitis.
PMID- 10778677
TI - Carcinoma colon presenting as paraneoplastic syndrome neuropathy.
PMID- 10778678
TI - Benzathine penicillin.
PMID- 10778679
TI - Neuroleptic malignant syndrome.
PMID- 10778680
TI - Neuroleptic malignant syndrome.
PMID- 10778681
TI - Use of BCG as aerosol may import better immunity against tuberculosis.
PMID- 10778682
TI - Terfenadine should be withdrawn from clinical use.
PMID- 10778683
TI - Clinical relevance of reduced bioavailability of rifampicin.
PMID- 10778684
TI - Is the practice of routine sputum cultures a "sacred cow"?
PMID- 10778685
TI - Cell mediated immunity to Plasmodium vivax infection: in vitro inhibition of
parasite growth by monocyte derived macrophages.
AB - OBJECTIVE: To study the ability of soluble blood stage or cell associated
antigens of Plasmodium vivax to stimulate human peripheral blood mononuclear
cells (PBMC) and produce factors capable of causing inhibition of parasite growth
in vitro was the objective of this investigation. METHOD: A local isolate of P
vivax was either synchronized by triple sorbitol lysis for antigen preparation or
used as unsynchronized culture for parasite inhibition, employing a macrophage
inhibition assay. The soluble or cell associated antigens of P vivax were added
to human monocyte derived macrophages with P vivax parasitized red blood cells.
The percent inhibition of parasite growth was examined after 72 hrs by microscopy
of Giemsa stained smears of red blood cells from the experimental and control
groups. RESULTS: The differences in parasite inhibition were compared using
Wilcoxon rank sum test for paired differences. Unstimulated PBMC supernatants did
not inhibit parasite growth. Significant inhibition of parasite growth (90%) was
seen after incubating P vivax infected erythrocytes with PBMC supernatants
resulting from stimulation with soluble antigens (T = 3; P < 0.05). However, the
cell associated antigens of P vivax did not stimulate PBMC to activate
macrophages for parasite killing in vitro (T = 14, P < 0.05). CONCLUSION: We
conclude that the soluble blood stage antigens of P vivax can stimulate human
PBMC to produce factors capable of activating macrophages to function as effector
cells in P vivax malaria.
PMID- 10778686
TI - Cryptococcal meningitis in acquired immunodeficiency syndrome.
AB - OBJECTIVE: To study the clinical course and outcome of cryptococcal meningitis
(CM) in patients with acquired immunodeficiency syndrome (AIDS). METHOD: Patients
infected with human immunodeficiency virus (HIV) and symptoms suggestive of
meningitis were evaluated with detailed history, clinical examination and
investigations. Diagnosis of CM was based on positive India ink preparation or
positive fungal culture of CSF. All patients were treated with amphotericin those
showing response were put on oral fluconazole. RESULT: A total of 431 patients
with HIV infection were admitted to this centre during the study period, of these
15 were diagnosed to have CM. Majority of the patients had a subacute
presentation with signs of meningeal irritation seen in only seven patients.
India ink preparation and positive fungal culture on cerebrospinal fluid (CSF)
established diagnosis in all cases. All patients were treated with amphotericin B
and fluconazole. Complete response was noticed in seven patients, two patients
were lost to follow-up and six patients died during the course of therapy. Raised
intracranial tension (ICT) and disseminated disease were associated with poor
prognosis. CONCLUSION: CM is a common opportunistic fungal infection in patients
with AIDS. A high index of clinical suspicion and routine mycological
surveillance is required to diagnose this infection. Majority of patients respond
to therapy except those who have disseminated infection, altered sensorium and
features of raised ICT at presentation.
PMID- 10778687
TI - Antihypertensive efficacy and tolerability of once-daily sustained-release
diltiazem alone and in combination with ramipril in hypertension.
AB - This study assessed once-daily (OD), sustained-release (SR) diltiazem alone and
in combination with ramipril in essential hypertension. Fifty patients with
supine diastolic blood pressure (DBP) > or = 95-< or = 114 mm Hg were entered
into the active treatment phase of the study after 2 weeks of placebo run-in.
Sustained-release diltiazem 180 mg OD was administered for 2 weeks, then
optimally titrated, at 2 week intervals, to SR diltiazem 240 mg OD and then SR
diltiazem 180 mg + ramipril 2.5 mg OD to achieve supine DBP < or = 90 mm Hg.
After 4 weeks of diltiazem monotherapy (SR diltiazem 180 mg or 240 mg OD) mean
supine DBP was reduced from 102.84 +/- 3.81 mm Hg to 90.15 +/- 5.02 mm Hg (P <
0.01) and mean supine heart rate was reduced from 85.15 +/- 11.02 bpm to 77.62 +/
11.45 bpm (p < 0.01). Diltiazem monotherapy reduced supine DBP to < or = 90 mm
Hg in 35/45 (77.77%) patients. Combination therapy (SR diltiazem 180 mg +
ramipril 2.5 mg OD), received by non-responders to diltiazem monotherapy, reduced
supine DBP to < or = 90 mm Hg in 3/10 (30%) patients. Sinus bradycardia was
observed in one patient. Sustained-release diltiazem alone and in combination
with ramipril reduce blood pressure in a dose related manner and is well
tolerated.
PMID- 10778688
TI - Variable clinical severity of Hb E beta-thalassemia among Indians.
AB - OBJECTIVE: The aim of this preliminary report was to look at the effect of
genetic variations in the alpha, beta and gamma globin genes in 7 cases of
hemoglobin E/beta-thalassemia with diverse clinical expression of the disease.
METHODS: beta-thalassemia mutations were characterized by PCR and dot blot
hybridization. G gamma gene polymorphism (Xmnl) was determined by PCR followed by
restriction enzyme digestion and polyacrylamide gel electrophoresis. alpha
genotyping was done by Southern blot hybridization. RESULTS: Six cases had a
severe beta+ mutation [IVS 1 nt 5 (G-->C)] and one case had a beta zero mutation
[F/S 41/42 (-CTTT)]. Hence, the beta-thalassemia mutation does not seem to
contribute towards the clinical diversity. alpha-genotyping showed a single alpha
gene deletion of the rightward type in three of the five milder cases. The -158 G
gamma (C-->T) substitution was present at least in heterozygous state (+/-) in
all the milder cases. CONCLUSIONS: Deletional alpha thalassemia and presence of
the -158 G gamma (C->T) substitution are the two factors which appear to be more
important in decreasing the severity of the disease rather than the nature of the
beta thalassemia mutation.
PMID- 10778689
TI - Comparison of efficacy of intravenous diltiazem and esmolol in terminating
supraventricular tachycardia.
AB - OBJECTIVE: Paroxysmal supraventricular tachycardia (PSVT) can be effectively
terminated by the intravenous administration of adenosine or verapamil. However
adenosine is expensive and injectable verapamil currently is scarcely available.
While intravenous diltiazem has been shown to be useful for terminating PSVT, the
efficacy of esmolol in this regard has not been evaluated previously. Hence these
latter two drugs were studied for their efficacy in terminating PSVT. METHODS: A
prospective, randomised, crossover study was undertaken in patients presenting
with hemodynamically tolerated PSVT to the ICCU. While 50 patients had been
planned for the trial, the study had to be prematurely terminated after 32
patients had been enrolled due to the marked superiority of diltiazem. Two
sequential doses with a 5 minute interval of either drug were administered before
crossover. Diltiazem was given in a dose of 0.25 mg/kg while the esmolol dose was
0.5 mg/kg. RESULTS: Diltiazem terminated PSVT in all the 16 patients in whom it
was given as the first drug. The 12 patients who did not respond to esmolol were
also effectively treated with diltiazem. Thus totally 28/28 patients responded to
diltiazem while only 4/16 patients responded to esmolol (p < 0.001). Of the 28
patients who responded to diltiazem, in 13 patients the second bolus of diltiazem
worked after the first one had failed. No significant adverse effects were seen.
CONCLUSION: Intravenous diltiazem is highly effective and safe for terminating
PSVT. When the first bolus is ineffective, the second bolus given after 5 minutes
usually succeeds. Esmolol in the dose of 0.5 mg/kg has poor efficacy for
terminating PSVT, even when 2 boluses are administered.
PMID- 10778690
TI - Can we diagnose early Barrett's oesophagus?
AB - OBJECTIVES: The definition of Barrett's oesophagus, has been of late, is stressed
on the presence of specialised columnar epithelium with goblet cells and not on
other metaplastic epithelia, which however could be the early, immature,
undifferentiated cell types such as junctional and gastric types. Hence this
study was carried out to find out the ways of detecting the early metaplastic
cell forms before the goblet cells appear. METHODS: Among 134 cases of reflux
oesophagitis selected in the prospective study of 7 years from January 1992 to
December 1998, 31 biopsies were diagnosed as Barrett's oesophagus (BO). These
were compared with 20 age matched control biopsies from gastro-oesophageal
junction. They were studied morphologically, morphometrically and histochemically
for acid, neutral and sulphomucins using alcian blue (AB), alcian blue-periodic
acid Schiff (AB-PAS) and high iron diamine-alcin blue (HID-AB) stains. RESULTS:
Twelve of the cases were of junctional type, 16 of specialised columnar
intestinal metaplastic (IM) type (Type I = 0, Type II = 5, Type III = 11) and
three showed a combination of both junctional and Type I IM. Mucins were a
mixture of neutral mucin, sialomucin and sulphomucin while the control biopsies
showed chiefly neutral mucin. Morphometrically, the epithelial cells in BO were
taller (mean 28u in junctional types and 32u in IM) in comparison to the control
(mean 24.5 u). CONCLUSION: When the classical specialised columnar epithelium
(with goblet cells) in oesophagus is absent, presence of metaplastic junctional
type of mucosa, may, for all probabilities be considered as the initial step
towards transformation to the classical Barrett's mucosa. In such situations, it
is essential to differentiate it from the normal gastro-oesophageal junctional
epithelium and is possible with histochemical analysis of the biopsy material
aided by morphometry, especially so when the level of biopsy is not indicated.
PMID- 10778692
TI - A rational approach for the assessment of clinical competence of undergraduate
medical students.
PMID- 10778693
TI - Screening of sputum: an experience in a tertiary care hospital.
AB - In order to reduce the work load on the clinical laboratory, it has been
recommended that sputum samples, before accepting for culture, should be looked
for the presence of polymorphs and squamous epithelial cells. (An appropriate
sample should have more than 25 polymorphs per low power field and less than 10
epithelial cells per low power field; others are labelled as inappropriate). We
examined this criteria for it's suitability on 1043 samples received at the
clinical bacteriology laboratory at the All India Institute of Medical Sciences
(AIIMS) for a period of one year (September, 1996 to August, 1997). Four hundred
samples were found appropriate while 643 were inappropriate as per recommended
criteria. Amongst the 400 appropriate samples, 215 were culture positive and 185
grew normal flora. However, we found that out of 643 inappropriate samples, 195
were culture positive (p < 0.01, statistically significant). The data was further
divided into hospitalized and OPD cases. The distribution of culture positive
cases in the appropriate samples was again found to be highly significant. It is
apparent from our results that an attempt to process an inappropriate sample does
not provide useful information.
PMID- 10778691
TI - Tuberculous lymphadenitis in children--role of fine needle aspiation cytology.
AB - OBJECTIVES: Tuberculosis in children remains misdiagnosed, underdiagnosed or
paradoxically overtreated as a result of diagnostic difficulties and non-specific
manifestations such as lymphadenopathy. The aims of the study were, i) To assess
the efficiency of fine needle aspiration cytology (FNAC) in comparison to
histology to determine the prevalence of tuberculosis in lymph nodes, ii) To
compare the cytological and histopathological features of lymphadenopathy in
children to adults, iii) To analyse the clinical significance of the results in
the context of diagnosis. MATERIAL AND METHODS: The biopsies of lymph nodes
obtained during the seven year period from January 1989 to December 1995 and the
lymph nodes on which fine needle aspiration cytology was done during the period,
January 1990 to December 1995 were included for the study. Hemotoxylin and Eosin
stain was used for basic evaluation of the histopathologic features. A grading
system of 0 to 5+ was used to assess the smears to categorise them into
diagnostic groups. RESULTS: Among 1396 lymph node biopsies submitted for
evaluation of non-neoplastic conditions 54.12% (741) showed tuberculosis, in
which children constituted 9.04%. A higher incidence of 68.61% was observed on
FNAC. Both on cytology and histology, a necrotizing type of inflammation was
observed more in children, which indicated hypersensitivity. CONCLUSION: FNAC was
found to be a useful adjunct diagnostic technique especially in children, but the
need to develop a sensitive and easily available method to diagnose in
asymptomatic and high risk children still persists. Selection of patients with
lymphadenopathy for more than three weeks is important, as otherwise nonspecific
changes and acute inflammatory changes are likely to interfere with the
diagnosis.
PMID- 10778694
TI - Hereditary hemolytic disorders among the Ashram school children in Mayurbhanj
district of Orissa.
AB - Hemoglobinopathy and allied hemolytic disorders are important genetic and public
health problems in Orissa. These cause high degree of hemolytic anemia, morbidity
and mortality in the vulnerable populations. A total of 465 Ashram School
children aged 6-15 years belonging to Bathudi, Bhumiz, Kolha and Santal tribes in
six localities of Mayurbhanj district of Orissa were screened for
hemoglobinopathy, glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, ABO and
Rhesus blood groups serology and any other hereditary condition. The sickle cell
trait (Hb AS) was detected in Santal (1.0%), Bathudi (1.0%) and Bhumiz (0.9%)
tribals. No case of homozygous sickle cell disease was detected among the tribes
of Mayurbhanj district. The beta-thalassemia trait was detected in Santal (8.0%),
Kolha (2.0%), Bhumiz (1.7%) and other tribal (3.8%) students. Sickle cell
hemoglobinopathy and beta-thalassemia are prevalent in this district among the
tribes, but the frequency is very low. The prevalence of G-6-PD deficiency is
considerably high (7.7-9.8%) among the tribes of Mayurbhanj district in Orissa.
Out of total 43 G-6-PD deficient subjects, there were 32 males, 9 heterozygote
females and 2 homozygous females. This shows that the antimalarial drugs should
be administered with caution as these cause hemolytic anemia, sometimes fatal
also. The distribution of ABO and Rhesus blood groups shows the preponderance of
B blood group (33.8%) over O (29.6%) and 2.1% cases of Rhesus negativity were
detected among the Bathudi tribe. This pattern is consistent with the
characteristic features of tribal populations in India.
PMID- 10778695
TI - Utility of HemoCue in estimation of hemoglobin against standard blood cell
counter method.
AB - INTRODUCTION: There are various methods which have been recommended for
haemoglobin (Hb) estimation for assessment of anaemia. Each method has it's
advantages and limitations. OBJECTIVE: The present study was conducted to assess
the utility of HemoCue, a recent method, in assessment of haemoglobin against the
standard blood cell counter (BCC) method. METHODOLOGY: Eighty five venous blood
samples were collected, Hb was assessed in each by utilising the HemoCue and BCC
methods. The results were compared utilising the standard statistical methods.
RESULTS: The HemoCue provided consistently higher value in comparison to BCC by a
margin of 0.5 g/dl. It is known that the correlation coefficient is independent
of change of origin but mean gets affected. Therefore, we can subtract 0.5 g/dl
from the Hb estimates achieved by HemoCue through which all conditions regarding
better agreement between both methods get satisfied. The two assays correlated
well. CONCLUSION: The HemoCue method was found more rapid and easy in assessment
of total hemoglobin as compared to blood cell counter method with an adjustment
of 0.5 per dl.
PMID- 10778696
TI - The enigma of the endothelium.
AB - The endothelium was earlier regarded as a relatively inert layer performing
rather simple physiological functions. However extensive research has recently
revealed that the endothelial layer performs a vast array of functions such as
maintenance of vascular tone, control over coagulation and fibrinolysis besides a
lot of chemical interactions. More recently, endothelial dysfunction has been
implicated as important in the pathogenesis of atherosclerosis, coronary artery
disease, myocardial ischemia and post-intervention restenosis. The demonstration
that endothelial dysfunction may be reversible by employing various strategies
raises the possibility of retarding the progress or even preventing the process
of atherosclerosis thereby reducing the risk of acute cardiovascular events.
PMID- 10778697
TI - Multiple cranial neuropathy: a common diagnostic problem.
AB - Syndrome of multiple cranial palsies is a common clinical problem routinely
encountered in neurological practice. Anatomical patterns of cranial nerves
involvement help in localizing the lesion. Various infections, malignant
neoplasms and autoimmune vasculitis are common disorders leading to various
syndromes of multiple cranial nerve palsies. A large number of diffuse
neurological disorders (e.g. Gullian-Barre syndrome, myopathies) may also present
with syndrome of multiple cranial nerve palsies. Despite extensive biochemical
and radiological work-up the accurate diagnosis may not be established. Few such
patients represent "idiopathic" variety of multiple cranial nerve involvement and
show good response to corticosteroids. Widespread and sequential involvements of
cranial nerves frequently suggest possibility of malignant infiltration of
meninges, however, confirmation of diagnosis may not be possible before autopsy.
PMID- 10778698
TI - Newer antimalarials.
PMID- 10778699
TI - Acute disseminated encehalomyelitis with typhoid fever.
AB - A 45 year old male came with fever, headache, altered sensorium pallor and lower
gastrointestinal bleeding. Laboratory investigations confirmed typhoid fever.
Magnetic resonance imaging (MRI) was suggestive of acute disseminated
encephalomyelitis.
PMID- 10778700
TI - Acinetobacter meningitis following head trauma.
AB - A case of acinetobacter meningitis following head injury in a patient who
developed cerebrospinal fluid otorrhea, and did not have any neurosurgical
procedure, is presented. Previously reported cases are cited, with a review of
the literature. Pefloxacin monotherapy is associated with a poor clinical
response.
PMID- 10778702
TI - Neurocysticercosis presenting as chronic meningitis.
PMID- 10778701
TI - Mycobacterium fortuitum endocarditis and meningitis after balloon mitral
valvotomy.
AB - Mycobacteria rarely cause endocardial infections. We describe the clinical course
of a patient who developed endocarditis, and meningitis with Mycobacterium
fortuitum following balloon mitral valvotomy. The patient was treated with
amikacin and clarithromycin but did not respond. She developed haemolytic anaemia
as the terminal event.
PMID- 10778703
TI - HELLP syndrome.
PMID- 10778704
TI - Acute intermittent porphyria presenting postmenopausally for the first time.
PMID- 10778705
TI - Isolated agenesis of cerebellum.
PMID- 10778706
TI - Leukemoid reaction simulating acute promyelocytic leukemia.
PMID- 10778707
TI - Role of DNA probes in characterization of pathogenic and non-pathogenic E.
histolytica.
PMID- 10778708
TI - Blood pressure measurement: application of new units educatory role of new
working groups.
PMID- 10778709
TI - Gliclazide, a better choice for type 2 diabetes.
PMID- 10778710
TI - The circadian pattern of ischaemic heart disease events in Indian population.
PMID- 10778711
TI - CPR and adrenaline in anaphylaxis.
PMID- 10778712
TI - Wide pulse pressure in acute hepatic failure.
PMID- 10778713
TI - Paracetamol poisoning--the emerging threat.
PMID- 10778714
TI - [Can a woman become pregnant after a stem cell transplantation?].
AB - Three women with chronic myelogenous leukaemia underwent stem cell
transplantation. They all were concerned about their future fertility. The first
woman underwent egg donation when she was in complete remission, and gave birth
to a healthy son. The second one underwent an IVF treatment before stem cell
transplantation: 15 embryos were frozen. The third woman asked for
cryopreservation of ovarian tissue. This procedure is not (yet) possible in our
clinic. The possibilities and complications of these three procedures are
discussed as well as the indication for the possible cryopreservation of ovarian
tissue.
PMID- 10778715
TI - [Cryopreservation of ovarian tissue open for discussion].
AB - In view of the promising developments in preclinical studies on the
cryopreservation of human ovarian tissue offering this technology as a 'fertility
insurance' to cancer patients can be justified. This commentary briefly discusses
some of the ethical issues involved, including the doctors responsibility
regarding the risk of the reintroduction of cancer, the pros and cons of both
xenotransplantation and in vitro maturation, parental responsibility in
consenting to fertility insurance for minors, and cryopreservation of ovarian
tissue of younger, healthy women who wish to postpone fertility.
PMID- 10778716
TI - [Cryopreservation of ovarian tissue; now is the time for ethical considerations].
AB - The development of ovarian tissue cryopreservation will expand the range of
clinical applications in reproductive medicine. This emerging technology may have
beneficial opportunities for patients, particularly in oncology, as well as for
the process of oocyte donation. However, it will also lead to new moral problems
requiring critical reflection concerning the criteria for tissue banking and
future clinical applications. Because cryopreservation of ovarian tissue nowadays
is the focus of experimental research, technology assessment is currently
appropriate, anticipating introduction into clinical practice. Specific
guidelines, developed by the medical profession in cooperation with ethicists and
lawyers can contribute to prudent clinical use.
PMID- 10778717
TI - [Treatment of young transsexuals in the Netherlands].
AB - For more than ten years transsexual adolescents have been diagnosed and treated
psychologically at the department of Child and Adolescent Psychiatry, University
Medical Centre in Utrecht, the Netherlands. The medical part of the treatment
takes place at the Academic Hospital of the Free University of Amsterdam.
Diagnosis is done in two phases: the first diagnostic phase and the 'real life
test'. In this second phase the ability to live in the opposite gender role is
tested. Gender dysphoric non-transsexual adolescents are offered psychological or
psychiatric interventions. For transsexual adolescents with the express wish to
undergo a sex change two types of hormones are prescribed. First, hormones which
halt the own pubertal development, then cross-sex hormones with irreversible
effects. Surgery for adolescents is not different from surgery for adults.
Although the cause of transsexuality is probably impaired sexual differentiation
at cerebral level, it appears that the risk of unjustified treatment is higher
when the treatment is administered at an early age than in adults; justified
treatment, however, has better results when it is administered at an early age.
PMID- 10778718
TI - [Cardiovascular effects of hypothyroidism].
AB - The clinical presentation of cardiac symptoms related to hypothyroidism is only
rarely observed nowadays due to early diagnosis of hypothyroidism by easily
available thyroid-stimulating hormone assays. A measurable abnormality of the
left ventricle is the lengthened duration of contraction and relaxation,
normalizing after restoration of euthyroidism. The ejection fraction and cardiac
reserve are only slightly diminished in hypothyroidism. There is reversible
diastolic disfunction. Pericardial effusion is a rare phenomenon. Diastolic
hypertension due to hypothyroidism is the most frequent cause of endocrine
hypertension. The relation between accelerated atherosclerosis and hypothyroidism
is not definitively proven. Patients below age 65 and without cardiac risk
factors can probably be treated with a full replacement dose of levothyroxin from
the beginning. There is no increased risk of percutaneous transluminal coronary
angioplasty or coronary artery bypass graft procedure in hypothyroid patients,
either during or after the intervention.
PMID- 10778719
TI - [Prevalence and treatment of hypercholesterolemia in patients with manifest
vascular disease according to practice guidelines of the current cholesterol
consensus].
AB - OBJECTIVE: To determine the prevalence of hypercholesterolaemia and the use of
lipid-lowering medication in patients with a manifest vascular disease. DESIGN:
Prospective, cross-sectional. METHODS: In patients who visited the University
Medical Centre Utrecht, the Netherlands, for the first time with a manifestation
of atherosclerosis in the period 1 September 1996-15 November 1998, we determined
by a single measurement of the cholesterol if they were eligible for lipid
lowering medication according to the cholesterol cut-off value mentioned in the
new Dutch cholesterol guidelines (1998) of the Dutch Institute for Health Care
Improvement. RESULTS: The study group comprised 737 patients: 539 (73%) males and
198 (27%) females, with a mean age of 62 year. 500 (68%) were eligible for lipid
lowering treatment. 66 patients (9%) were being treated according to the
guidelines and in 106 (14%) the aim of a cholesterol lower than 5.0 mmol/1 was
not reached despite cholesterol lowering medication. In 328 patients (45%)
hyperlipidaemia was not treated pharmacologically. CONCLUSION: Two-thirds of the
patients with manifest vascular disease had hypercholesterolaemia. Many of these
patients were not yet being treated.
PMID- 10778720
TI - [Ethanol for treatment of delirium in alcohol dependent patients on intensive
care units in the Netherlands: efficacy not proven].
AB - OBJECTIVE: To determine the use of ethanol in Dutch intensive care departments
(ICUs) for the treatment of deliriant symptoms in alcohol-dependent patients, and
to study the literature data concerning this use. DESIGN: Literature search and
questionnaire. METHOD: In Medline a search was performed from 1993 onward with
keywords 'intensive care' and 'alcohol'/'alcohol withdrawal syndrome'/'delirium'.
All Dutch ICUs received a written questionnaire (n = 247) concerning the use of
ethanol in this patient group. RESULTS: According to the literature the syndrome
is characterized by autonomous hyperactivity, resulting in tachycardia,
tachypnoea, hypertension, perspiration, fever, tremors en fear. In delirium
caused by alcohol withdrawal benzodiazepines are advised, sometimes in
combination with haloperidol. ICUs sometimes use ethanol, although the
effectiveness in preventing or treating withdrawal symptoms has never been
ascertained in scientific investigations: in a meta-analysis the conclusion is
drawn that the studies are too small and insufficiently objective to determine
the effectiveness. The response to the questionnaire was 55% (96/176). From all
ICUs, 15 (16%) used ethanol occasionally, and treated an estimated 17% of the
admitted alcohol-dependent patients. There was a tendency for large ICUs to use
ethanol in these patients more frequently. Each ICU used its own method to
calculate the required ethanol dosage. Calculation on the basis of these dosages
indicated a plasma ethanol concentration of at most 0.5 promille. CONCLUSION:
Because only a small percentage of deliriums on ICUs are caused by alcohol
withdrawal, and the effectiveness of ethanol in alcohol-dependent patients with a
delirium has never been proven, the use of ethanol in such cases is discouraged.
PMID- 10778721
TI - [Two patients with emphysematous pyelonephritis].
AB - A 55-year-old man with diabetes mellitus was sick with shivering, abdominal pain
and Escherichia coli in blood and urine cultures; a 40-year-old woman with
asthmatic bronchitis had abdominal pain and anaemia. Both had renal dysfunction
and the CT scan showed hydronephrosis with a perirenal inflammatory infiltrate
and gas in the right and left renal pelvis, respectively. The man had a difficult
recovery after treatment with antibiotics and percutaneous drainage. In the
woman, a calculus obstructed the pyelo-ureteral passage; the resected kidney
contained a squamous cell carcinoma. She was operated, received chemotherapy and
recovered. Emphysematous pyelonephritis is a rare, severe disease. Percutaneous
drainage and, if necessary, nephrectomy are paramount in the treatment. The
condition is observed mostly in patients with diabetes mellitus or obstruction of
the urinary tract.
PMID- 10778722
TI - [Respiratory syncytial virus infections and preventive options].
PMID- 10778724
TI - [Electronic medical record, confidentiality, and safeguarding of privacy].
PMID- 10778723
TI - [Creative mathematics with clopidogrel; exaggeration of the preventive effect by
the pharmaceutical company].
PMID- 10778726
TI - Brain tumor invasion rate measured in vitro does not correlate with Ki-67
expression.
AB - The need for more accurate prediction of the biological behavior of brain tumors
has lead to the use of immunohistochemical methods for assessment of
proliferating cell nuclear antigens such as Ki-67. There is a variable
association of glioma Ki-67 labeling index with patient survival. Brain invasion
by individual tumor cells also defines biological aggressiveness, and can be
assessed in vitro. Further, proliferation and migration seem to be mutually
exclusive behaviors for a given cell at a point in time. We studied the
relationship between Ki-67 labeling index and invasion rate in a group of 10
gliomas, and 2 meningiomas. Human tumor spheroids obtained from operative
specimen were co-cultured with fetal rat brain aggregates, and invasion rate was
measured by confocal microscopic observation. There was no correlation between
two measures of invasion and Ki-67 labeling. This finding supports the
dichotomous nature of glioma proliferation and invasion, and may in part explain
the limited usefulness of proliferation marker labeling.
PMID- 10778725
TI - Pediatric medulloblastoma: prognostic value of p53, bcl-2, Mib-1, and microvessel
density.
AB - The aim of this study was to retrospectively assess the prognostic value of p53
and bcl-2 protein expression, cell proliferation index (Mib-1 index), and tumor
microvessel density (factor VIII-related antigen) in pediatric medulloblastoma
patients. Tumor specimens of 55 patients (age 2-18 years) with medulloblastoma
treated with a curative intent between 1972 and 1991 were studied. Slides of
paraffin embedded tissue were stained with monoclonal antibodies (mAb) and
examined under high power light microscopy for the presence of immunoreactivity.
Microvessel density was scored both in the area of most intense staining ('Angio
max') and in 3 additional randomly selected areas. The sum of these 4 scores was
termed 'Angio-total'. 'Angio-max' and 'Angio-total' were evaluated separately by
two independent investigators to assess reproducibility. None of the parameters
studied, i.e. p53 or bcl-2 expression, Mib-1 index or microvessel density scores
were associated with patient survival. Microvessel scores between observers were
significantly but weakly correlated, with correlation coefficients (r) < 0.5 for
both 'Angio-max' and 'Angio-total'. Leptomeningeal spread at diagnosis was the
only independent factor associated with a poor survival (p = 0.003). There was no
association of leptomeningeal metastasis with any of the biological markers
tested in this study.
PMID- 10778727
TI - Vascular endothelial growth factor (VEGF) in astrocytic gliomas--a prognostic
factor?
AB - Survival in astrocytic gliomas is closely related to WHO tumor grade. Within one
tumor grade, especially in grade II and III tumors, the clinical course is
variable and can hardly be predicted by histological criteria. Neovascularization
is a neuropathological hallmark in high grade gliomas and angiogenic factors may
play an important role in malignant tumor progression. Therefore, 162 primary
astrocytic gliomas (57 astrocytomas WHO grade II, 27 astrocytomas WHO grade III
and 78 glioblastomas WHO grade IV) were investigated immunohistochemically for
expression of vascular endothelial growth factor (VEGF), which is considered to
represent the main angiogenic factor in astrocytic gliomas. Clinical data known
to influence prognosis were documented. VEGF expression was found in 21 of 57
astrocytomas WHO grade II (36.8%), in 18 of 27 astrocytomas WHO grade III (66.7%)
and in 50 of 78 glioblastomas (64.1%). A strong correlation between VEGF
expression and survival was found within the whole study group, however, within
one tumor grade no such correlation was obvious. In a multifactorial analysis
VEGF expression was not found to be an independent prognostic factor in
astrocytic gliomas.
PMID- 10778728
TI - Expression of TGFalpha in meningiomas.
AB - The objective of this study was to examine the expression of transforming growth
factor alpha (TGFalpha), a mitogen for many cell types, and its receptor in basic
subtypes of meningiomas as well as in meningiomas of varying grade. Formalin
fixed tissues from 26 meningiomas including 15 benign (5 meningothelial, 5
transitional, and 5 fibrous variants), 6 atypical, and 5 malignant examples were
immunohistochemically examined for both TGFalpha protein and EGF/TGFalpha
receptor protein. In addition, in situ hybridization (ISH) was used to detect
TGFalpha mRNA expression. Immunostaining for TGFalpha was strongest in fibrous
and atypical meningiomas, followed closely by transitional and malignant tumors.
Only weak reactivity was observed in the meningothelial variant. In all but 4
tumors (2 fibrous, 2 atypical), ISH showed TGFalpha mRNA to be present, the
signal being stronger in malignant than in conventional or atypical tumors.
Lastly, immunostaining for EGF/TGFalpha receptor was positive in all tumors
studied. Strong TGFalpha protein expression in meningiomas is commonly associated
with fibrous morphology. Although the frequent detection of both TGFalpha protein
and its mRNA, as well as of EGF/TGFalpha receptor within tumors of all type and
grades, suggests that TGFalpha serves to promote tumor growth, its possible role
in tumorigenesis or malignant progression is uncertain. In summary, demonstration
of these substances is of no utility in the classification or grading of this
common tumor because the differences in their expression among the various
meningioma subtypes were not statistically significant.
PMID- 10778729
TI - Progressive disease in children with medulloblastoma/PNET during preradiation
chemotherapy.
AB - The overall prognosis in children with medulloblastoma/PNET has not significantly
improved over the past decade. Intensive neoadjuvant chemotherapy has not yet
adequately explored. We evaluated the short-term clinical results of an intensive
chemotherapy regimen in high risk children with newly diagnosed MB/PNET, after
surgery and before radiation. Twelve previously untreated patients with high-risk
medulloblastoma/PNET, according to Chang's classification, were treated with the
following chemotherapy regimen: high dose carboplatin 600 mg/m2/day on days 1 and
2; the same course was administered 4 weeks later. One month later, high dose
cyclophosphamide 2 g/m2/day on days 1 and 2, followed by an identical course 4
weeks later. Vincristine 1, 5 mg/m2 i.v. was given on the first day of each
course. Systemic evaluation of the disease included imaging of the entire
neuraxis, including MRI of the entire spine. Out of 12 enrolled, 7 patients were
able to be evaluated for a residual disease after surgery. After two cycles of
high dose carboplatin, we noted 1 CR, 4 PR and 2 MR. After the subsequent two
cycles of high dose cyclophosphamide we observed an additional response in 4
cases. On the other hand, 4 patients clearly showed evidence of PD immediately
after the first course of cyclophosphamide (2 cases) or following the second
course. Three of the 4 patients had shown respectively 1 CR and 2 PR after the
second course of carboplatin. Whereas it was confirmed that 2 courses of high
dose carboplatin is effective in high risk MB/PNET children, we observed an
unacceptable number of PD during the subsequent high dose cyclophosphamide
therapy. A review from the literature also suggests that, in general, the longer
radiotherapy is delayed, the higher the incidence of PD. In the search for the
optimal drug combination in "sandwich chemotherapy" for children with high risk
MB/PNET, PD must be reduced to an acceptable incidence, since a high number of PD
may significantly lower the probability of long-term survival.
PMID- 10778730
TI - Pilot study of local autologous tumor infiltrating lymphocytes for the treatment
of recurrent malignant gliomas.
AB - A prospective pilot study was performed in order to assess the safety of treating
recurrent malignant gliomas (MGs) with locally infused autologous tumor
infiltrating lymphocytes (TILs) and recombinant interleukin-2 (rIL-2). Six
patients were entered between June 27, 1994 and June 2, 1995 and followed until
July 1, 1998. At surgery an Ommaya reservoir was placed for later infusion of
TILs and rIL-2. Following surgery, autologous TILs were expanded in vitro in the
presence of rIL-2 and infused on treatment days 1 and 14, with concurrent rIL-2
infusions performed three times each week for one month. Following completion of
immunotherapy all patients were offered chemotherapy. Phenotypic analysis
demonstrated TILs to be T-lymphocytes (87-99% CD3+). Of these, 4 of 6 cases (67%)
phenotyped as cytotoxic/suppressor T-lymphocytes (CD8+) and 2 of 6 cases (33%)
phenotyped as helper/inducer T-lymphocytes (CD4+). TILs demonstrated limited
selective cytotoxicity, with dose dependent cytotoxicity against autologous
tumor, allogenic tumor and long term MG cell lines. There were no significant
(Grade 3 or 4) complications. One patient developed transient low grade fevers,
and 2 developed asymptomatic hydrocephalus. All patients developed transient and
asymptomatic cerebral swelling, noted on the immediate post-treatment imaging
studies. At three and six month follow-up, 3 patients responded with partial
response, 2 demonstrated stable disease and 1 patient progressed. At long term
follow-up, 1 patient had a complete response (45 month follow-up), 2 had a
partial response (48 and 47 month follow-up) and 3 patients expired as a result
of progressive disease (at 12, 12 and 18 months following immunotherapy). A
relationship between subsequent chemotherapy or extent of resection to outcome
was not apparent but could not be excluded. This pilot study demonstrated that
locally infused autologous TILs and rIL-2 could be delivered without serious
toxicity. Further studies are indicated to determine the safety and long term
efficacy of TIL immunotherapy.
PMID- 10778731
TI - Radiation and concomitant weekly administration of paclitaxel in patients with
glioblastoma multiforme. A phase II study.
AB - The present study was conducted to evaluate the activity and toxicity profile of
radiation (RT) and concomitant chemotherapy in patients with glioblastoma
multiforme (GBM). Thirty-nine patients were treated postoperatively with RT and
concomitant administration of paclitaxel. Cranial irradiation was initiated 2-3
weeks postoperatively and was administered in 2.0 fractions, one fraction per
day, for 5 consecutive days per week, to a total of 60 Gy. Paclitaxel was
delivered at a dose of 100 mg/m2 over 3-h once weekly for 6 weeks. Thirty-three
patients received all 6 cycles of paclitaxel according to the protocol. Totally,
217 cycles were delivered all of them at full dose. The median relative dose
intensity of paclitaxel was 1 (range 0.88-1.1). Three (7.5%) patients achieved
complete and 9 (23%) partial response, while 12 (30.5%) patients demonstrated
stabilization of the disease. Side effects from combined chemoradiotherapy were
mainly mild. Grade III toxicity included infection (7.5%) and alopecia (5%).
Median time to progression was 6 (range 0.9-27) months and median survival 10.7
(range 0.9-39.5+) months. The present study has clearly shown that 100 mg/m2 of
paclitaxel in 1-h infusion weekly can be safely given concomitantly with RT in
patients with GBM with manageable toxicity. However, the efficacy of this
combined modality treatment does not appear to be superior to that of RT alone.
PMID- 10778732
TI - Post-radiotherapy myelitis observed in an AIDS patient with a meningioma: case
report and review of the literature.
AB - Radiation myelitis is an uncommon but serious complication of radiation therapy.
Although the definitive threshold to cause myelitis is unknown, it is believed
that less than 50 Gy when given in 25 or more fractions is highly unlikely to
cause myelopathy. This report describes a case of myelitis within the
radiotherapy portal in an HIV infected patient who received radiation therapy for
an atypical meningioma located in the cervical spine. A complete resolution of
the meningioma was also noted in this case. The possible contributing roles of
HIV infection and concomitant administration of antiviral drugs are discussed.
PMID- 10778733
TI - Clinical trial of intrathecal administration of 5-fluoro-2'-deoxyuridine for
treatment of meningeal dissemination of malignant tumors.
AB - Intrathecal administration of 5-fluoro-2'-deoxyuridine (FdUrd) was performed in
patients with meningeal dissemination of malignant tumors during the period from
January 1996 to September 1998, and they were followed up until February 1999.
The study population consisted of 23 patients: 12 with lung cancer, 4 with breast
cancer, 2 with colon cancer, 1 with malignant lymphoma, 2 with glioblastoma and 2
with metastatic brain tumors of unknown origin. FdUrd was administered
intrathecally through an Ommaya reservoir placed in the lateral ventricle
initially at a dose of 1 microg twice per week, and the dose was increased to 10
microg and administration schedule was also increased every day. Headache and
nuchal pain were relieved in all patients regardless of responsiveness to
intrathecal FdUrd therapy as determined from the findings in the cerebrospinal
fluid (CSF). Patients showed no side effects during the course of intrathecal
chemotherapy except for slight nausea in two patients and dull headache in one.
Sixteen of the 23 patients showed decreased cell number in the cerebrospinal
fluid (CSF). Positive cytological findings in CSF became negative in 6 of the 23
patients, and the levels of CSF tumor markers were decreased in 14.
Responsiveness to intrathecal administration of FdUrd was defined as 'response'
when both the cell number and tumor markers were decreased in both ventricular
and spinal CSF or when the cell number was decreased in cases in which the tumor
markers were not detected. Overall, 16 of the 23 patients (70%) showed complete
or partial responses to intrathecal FdUrd therapy as determined from CSF
findings. These results demonstrated the efficacy of intrathecal FdUrd
chemotherapy without apparent neurotoxicity for treatment of meningeal
dissemination of malignant tumors.
PMID- 10778734
TI - Carboplatin therapy for optic pathway tumors in children with neurofibromatosis
type-1.
AB - Symptomatic optic pathway tumors (OPT) occur in 7% of children with
neurofibromatosis type-1 (NF-1). Although tumor progression following diagnosis
is unusual in such children, specific therapy may be necessary for patients with
either severe or progressive disease. We reviewed the records of 9 children (6
girls, 3 boys) with NF-1 associated OPT who were treated with the second
generation platinum compound carboplatin. Carboplatin was given at a dose of 560
mg/mm2 every 4 weeks for a mean of 15 cycles. The mean age at presentation of the
OPT was 3.4 years. Eight children had abnormal ophthalmologic examinations at the
time of diagnosis. Only 4 patients had documented evidence of progressive disease
prior to the institution of therapy. No patient had evidence of progressive
disease following therapy. Four patients had radiologic evidence of tumor
shrinkage and 2 patients had definite improvement in vision. There was only
minimal toxicity. In conclusion, carboplatin is a safe and effective treatment
for OPT in children with NF-1. However, as disease stabilization of NF-1
associated OPT often occurs following clinical presentation, the clinician should
document tumor progression or visual deterioration prior to the institution of
therapy.
PMID- 10778735
TI - Lupine leghemoglobin I: expression in transgenic Lotus and tobacco tissues.
AB - The proximal parts of the promoters of the genes for symbiotic-type hemoglobins
are generally conserved, but the promoter of the lbI gene of lupine (LulbI) shows
some unusual structural features. It lacks typical organ-specific elements
characteristic of all the leghemoglobin gene promoters described thus far. We
have analysed its functional activity in transgenic Lotus corniculatus. A fusion
construct between the lbI promoter and the GUS reporter gene was expressed mainly
in the central zone of the root nodule, but the product was also detected in the
non-nodule root zone and in roots in tissue culture. In roots of transgenic
tobacco, the activity of the promoter was only 24% lower than in Lotus nodules.
LulbI promoter activity was also detected in tobacco leaves. Lupine hemoglobin I
has a higher sequence identity to symbiotic-type hemoglobins and thus it groups
within the "Class II" hemoglobins.
PMID- 10778736
TI - Identification of Drosophila melanogaster RECQE as a member of a new family of
RecQ homologues that is preferentially expressed in early embryos.
AB - We describe the isolation of a new type of RecQ homologue in Drosophila
melanogaster, RECQE. The Recqe gene consists of five exons and four introns, and
encodes a protein of 1058 amino acids with a predicted molecular weight of
120,000 Da. The RECQE protein has seven helicase motifs. The helicase domain
shows 42% identity overall to that of Escherichia coli RecQ DNA helicase, and is
most closely related to Homo sapiens RecQL5 and Caenorhabditis elegans E03A3.2.
The C-terminal region of RECQE protein is unique and the longest known among
members of the RecQ superfamily. We demonstrate that the RECQE protein has DNA
helicase activity and that the C-terminal region is dispensable for this
activity. The RECQE mRNA accumulates in oocytes and is expressed at high levels
in early embryos. We show for the first time that the expression of a RecQ
homologue is developmentally regulated in embryos. These data suggest that the
DNA helicase activity of RECQE might be involved in the DNA metabolism of early
embryos.
PMID- 10778737
TI - Two loci on wheat chromosome 5A regulate the differential cold-dependent
expression of the cor14b gene in frost-tolerant and frost-sensitive genotypes.
AB - Although cold acclimation in cereals involves the expression of many cold
regulated genes, genetic studies have shown that only very few chromosomal
regions carry loci that play an important role in frost tolerance. To investigate
the genetic relationship between frost tolerance and the expression of cold
regulated genes, the expression and regulation of the wheat homolog of the barley
cold-regulated gene cor14b was studied at various temperatures in frost-sensitive
and frost-tolerant wheat genotypes. At 18/15 degrees C (day/night temperatures)
frost-tolerant plants accumulated cor14b mRNAs and expressed COR14b proteins,
whereas the sensitive plants did not. This result indicates that the threshold
temperature for induction of the wheat cor14b homolog is higher in frost
resistant plants, and allowed us to use this polymorphism in a mapping approach.
Studies made with chromosome substitution lines showed that the polymorphism for
the threshold induction temperature of the wheat cor14b homolog is controlled by
a locus(i) located on chromosome 5A of wheat, while the cor14b gene was mapped in
Triticum monococcum on the long arm of chromosome 2Am. The analysis of single
chromosome recombinant lines derived from a cross between Chinese Spring/Triticum
spelta 5A and Chinese Spring/Cheyenne 5A identified two loci with additive
effects that are involved in the genetic control of cor14b mRNA accumulation. The
first locus was tightly linked to the marker psr911, while the second one was
located between the marker Xpsr2021 and Frost resistance 1 (Fr1).
PMID- 10778738
TI - Isolation and molecular characterisation of the gene encoding the cytoplasmic
ribosomal protein S28 in Prunus persica [L.]] Batsch.
AB - RT-PCR was performed on peach (Prunus persica [L.] Batsch) RNA to isolate cDNAs
corresponding to transcripts which are differentially expressed in leaves borne
on basal and apical shoots. A gene was identified which was more highly expressed
in the leaves of basal shoots, and codes for the cytoplasmic protein S28 present
in the small ribosomal subunit. The 5' leader regions of RPS28 mRNAs were found
to harbour 8-11 pyrimidine tracts, which suggested similarities to regulatory
stretches that control the translation of mRNAs for ribosomal proteins in
animals. The peach S28 is encoded by two intron-containing genes, which are both
transcribed in mitotically active tissues such as developing leaves and roots. In
situ hybridisation to shoot vegetative apices and the measurement of
nucleus/nucleolus ratios indicated that RPS28 expression was confined to areas
undergoing active cell division. The mature RPS28 mRNA was detected as a single
species in actively dividing tissues such as apical tips, developing leaves,
vegetative buds, stamens, developing fruits and roots. In contrast, accumulation
of a precursor RNA, in the presence of the mature product, was found in fully
expanded leaves and subtending stems, while only the precursor species was
detected in several late-stage tissues. This phenomenon suggested that expression
of the mature RNA is controlled at the level of splicing and turnover of the
precursor RNA. This is similar to the mode of regulation of ribosomal protein
genes in animals.
PMID- 10778739
TI - Pea chloroplast FtsZ can form multimers and correct the thermosensitive defect of
an Escherichia coli ftsZ mutant.
AB - This paper reports the isolation and characterization of a cDNA encoding the FtsZ
protein of pea. The protein is synthesised as a precursor molecule of 423 amino
acids with a molecular mass of 44 kDa. When translated in vitro, the protein is
translocated efficiently into isolated, intact pea chloroplasts, demonstrating
that the protein is localised in the chloroplast. Pea FtsZ synthesised in vitro
formed multimers in a calcium-dependent manner. The pea cDNA complemented the
thermosensitive defect of an E. coli ftsZ mutant in vivo and converted the
filamentous phenotype of the E. coli mutant into the normal wild-type morphology
at 42 degrees C. However, pea FtsZ mutants that were defective in multimerisation
in vitro failed to correct the phenotype of the E. coli ftsZ mutant in vivo. The
pea ftsZ transcripts were abundantly present in the young leaves, but barely
detectable in roots and stems and undetectable in older leaves. Light stimulated
transcription of the gene significantly in young and dark-grown leaves. This
study strongly suggests that the division mechanisms used by chloroplasts and
bacteria show considerable similarity.
PMID- 10778740
TI - Intergenic complementation truncation mutants of cyclin-dependent kinase.
AB - The Saccharomyces cerevisiae genes PHO80 and PHO85 encode, respectively, a cyclin
and cyclin-dependent kinase, which negatively regulate PHO5 gene transcription by
phosphorylating the transcription activator Pho4p. Cyclin-dependent kinases
(CDKs) are highly conserved proteins, both within and between species. It was
previously demonstrated, using reporter genes activated in yeast by Pho4p, that
hybrid proteins in which over two-thirds of Pho85p were replaced with the
homologous region from human Cdk2 retained the function of native Pho85p with
respect to promoter repression. In the present study, various truncated forms of
the hybrid human-yeast CDKs were tested for function. Surprisingly, truncations
in which significant portions of the C-terminal region of the 291-residue hybrid
CDK were deleted retained activity. Genes encoding human Cdk2 proteins which
terminated after amino acids 151, 140, 130, 120 and 90 each complement a
chromosomal pho85 gene disruption in which the HIS3 gene is inserted at codon 49.
Truncated Cdk2 proteins containing less than 60 amino acids failed to complement
the pho85::HIS3 gene disruption. Although the functional C-terminal truncations
disrupt the ATP-binding and active sites of Cdk2, reporter gene repression
mediated by these truncated proteins is apparently due to phosphorylation of
Pho4p, since a gene in which the essential lysine codon at position 33 was
converted to an arginine codon does not complement the chromosomal gene
disruption. The human Cdk2 truncations were demonstrated to function through
intergenic complementation. The intact Cdk2-Pho85 hybrid CDK complemented the
pho85 mutation in yeast strains in which the entire PHO85 coding region was
deleted from chromosome XVI. The C-terminal Cdk2 truncations, however, were non
functional in these strains and thus dependent for activity on the pho85 coding
region which remained in the mutant pho85::HIS3 chromosomal locus. These genetic
results are consistent with a model involving protein fragment complementation in
which the active site of the CDK is bisected.
PMID- 10778741
TI - A novel nuclear factor, SREB, binds to a cis-acting element, SRE, required for
inducible expression of the Aspergillus oryzae Taka-amylase A gene in A.
nidulans.
AB - The Taka-amylase A gene (taaG2) of Aspergillus oryzae is inducibly expressed in
A. nidulans upon exposure to inducing carbon sources, such as starch and maltose.
In order to identify nuclear factor(s) possibly involved in the induction of the
taaG2 gene, gel mobility shift assays and DNase I footprinting analyses were
carried out, and revealed a novel nuclear factor in A. nidulans extracts, which
specifically bound to two sites in the taaG2 promoter region, -204 to -189 and
182 to -168, which share the common sequence GGAAATT. The nuclear factor was
detected in nuclei from both induced and uninduced mycelia. Mutational analysis
within and around the binding sequences demonstrated that only the upstream
binding sequence, designated SRE (starch responsive element), was required for
the inducible expression of the taaG2 gene, and thus we designated the nuclear
factor SREB (SRE binding factor). The downstream binding site contained an
inverted SRE (ISRE) and played no role in the induction of taaG2 expression. SREB
was shown by gel retardation assays to have higher affinity for SRE than for
ISRE.
PMID- 10778742
TI - Mutational accessibility of essential genes on chromosome I(left) in
Caenorhabditis elegans.
AB - We have analyzed a region of approximately 5.4 million base pairs for mutations,
which under standard laboratory conditions result in developmental arrest,
sterility, or maternal-effect lethality in Caenorhabditis elegans. Lethal
mutations were isolated, maintained, and genetically manipulated as homozygotes
using sDp2--a duplication of the left half of chromosome I. All of the lethals
and rearrangements used in this analysis were balanced by sDp2. Relatively low
doses of mutagen, (approximately 15 mM ethylmethane sulfate; EMS), were used so
as to limit the occurrence of second-site mutations, thus increasing the
probability of recovering single nucleotide substitutions. Treatment of over
32,400 marked chromosomes resulted in 486 analyzed mutations. In this paper, we
add 133 previously unidentified let genes, isolated in the EMS screens, and one
let gene identified by a gamma-ray induced mutation, to our collection of 103
essential genes. We also recovered lethal alleles of genes for which visible
mutants already existed. In total, eight deficiencies and alleles of 237
essential genes were identified. Eighty-nine of the previously unidentified let
genes are represented by more than one lethal allele. Statistical analysis
indicates a minimum estimate of 400 essential genes in the region of chromosome I
balanced by sDp2. This region occupies approximately half of chromosome I, and
contains over 1135 protein-coding genes predicted from the genomic sequence data.
Thus, approximately one-third of the predicted genes are estimated to be
essential. Of these approximately 60% are represented by lethal alleles. Less
than 2% of the lethal-bearing strains recovered in our analysis, including the
eight genetically definable deficiencies, carried more than one lethal mutation.
Several screens were used to recover mutations for this analysis. Because all the
mutations were isolated using the same balancer, under similar screening
conditions, it was possible to compare intervals within the sDp2 region with each
other. The fraction of essential genes that present relatively large targets for
EMS was highest within the central cluster (dpy-5 to unc-13).
PMID- 10778743
TI - The protein kinases Rck1 and Rck2 inhibit meiosis in budding yeast.
AB - The genes RCK1 and RCK2 of budding yeast were initially identified as suppressors
of checkpoint mutations in fission yeast. Here, we show that homozygous diploid
rck1/rck1 mutants in standard sporulation medium enter meiosis in about half the
time required by wild-type cells. A similar, but weaker, effect is seen in
rck2/rck2 mutants, whereas double homozygous rck1/rck1 rck2/rck2 mutants display
a phenotype similar to that of the rck1/rck1 single mutants. In diploids with
mutations in either of the meiotic checkpoint genes MEC1 and RAD24,
overexpression of RCK1 or RCK2 reduces meiotic proficiency, most prominently seen
with RCK2. The rate of meiotic recombination was unaltered in rck1 and rck2
mutants. There is a transient shift in the relative abundance of the two RCK2
transcripts in meiotic cells. We propose that one function of Rck1 and Rck2 is to
inhibit meiosis.
PMID- 10778744
TI - Structure and function of a pyrimidine/purine-biased sequence from the 5'
flanking region of the basidiomycete Lentinus edodes gene priA.
AB - The priA gene of the basidiomycete Lentinus edodes possesses a pyrimidine (CT)
rich stretch (26 bp) that includes a short (6-bp) repeat, the elements of which
form a mirror repeat at and near the transcriptional initiation sites. A DNA
fragment that included this sequence was inserted into pBR322, and the resulting
plasmids were introduced into Escherichia coli. Analysis of the susceptibility of
these pBR322 derivatives to cleavage by S1 nuclease, following isolation from E.
coli, indicated the formation of an open, S1-sensitive structure within and just
downstream of the CT/AG-biased sequence. Replacement of two dTMP residues in one
of the repeat elements by dGMP resulted in the elimination of the S1-cleavable
open structure from the plasmids. To analyze the effect of the CT/AG-biased
sequence from priA in the basidiomycete Coprinus cinereus, the integrating
vectors pLC2 and pLC2mutCT were used; these contained the wild-type priA promoter
and the mutant priA promoter with the aforementioned mutation in the mirror
repeat, respectively. The Streptomyces-derived bialaphos resistance gene (bar)
was fused downstream of the promoters, and the resulting plasmids, pLC2-bar and
pLC2mutCT-bar, were introduced into C. cinereus. Transformants carrying pLC2mutCT
bar grew significantly more slowly on bialaphos-containing agar plates and
contained a noticeably lower level of the bar transcript when compared with the
transformants obtained with pLC2-bar. These results suggest that an unusual
structure induced by the CT/AG-biased sequence is required for efficient gene
expression from the priA promoter.
PMID- 10778745
TI - Foxy: an active family of short interspersed nuclear elements from Fusarium
oxysporum.
AB - A novel family of short interspersed nuclear elements (SINEs) has been identified
in Fusarium oxysporum. This family has been called Foxy. The feature that makes
Foxy unique among SINEs is the presence of 5' terminal tetranucleotide repeats.
Both the number and the sequence of these repeats vary between individual members
of the family. The genome of F. oxysporum f. sp. lycopersici contains at least
160 copies of Foxy. In a mutant obtained upon gamma irradiation of a wild-type
isolate, 13 new Foxy insertions were identified. These observations, together
with the occurrence of many Foxy-specific polymorphisms between isolates within
one vegetative incompatibility group and the presence of Foxy-specific
transcripts in the fungus, indicate that Foxy is currently active and may
contribute to the genetic variability of F. oxysporum. Since we have not been
able to detect Foxy sequences by PCR analyses in other fungi, this novel family
of SINEs seems to be confined to Fusarium species.
PMID- 10778746
TI - Cloning and characterization of oah, the gene encoding oxaloacetate hydrolase in
Aspergillus niger.
AB - The enzyme oxaloacetate hydrolase (EC 3.7.1.1), which is involved in oxalate
formation, was purified from Aspergillus niger. The native enzyme has a molecular
mass of 360-440 kDa, and the denatured enzyme has a molecular mass of 39 kDa, as
determined by gel electrophoresis. Enzyme activity is maximal at pH 7.0 and 45
degrees C. The fraction containing the enzyme activity contained at least five
proteins. The N-terminal amino acid sequences of four of these proteins were
determined. The amino acid sequences were aligned with EST sequences from A.
niger, and an EST sequence that showed 100% identity to all four sequences was
identified. Using this EST sequence the gene encoding oxaloacetate hydrolase
(oah) was cloned by inverse PCR. It consists of an ORF of 1227 bp with two
introns of 92 and 112 bp, respectively. The gene encodes a protein of 341 amino
acids with a molecular mass of 37 kDa. Under the growth conditions tested, the
highest oah expression was found for growth on acetate as carbon source. The gene
was expressed only at pH values higher than 4.0.
PMID- 10778747
TI - Telomeric silencing of a natural subtelomeric gene.
AB - The heterochromatin at telomeres can repress the expression of reporter genes
when they are transplanted into their vicinity. Although this transcriptional
silencing has been widely characterized using reporter genes, the ability of
telomeres to repress natural subtelomeric genes has remained uncertain. In a
previous report we described telomeric silencing of a yeast retrotransposon. Here
we describe the identification of a subtelomeric gene from Saccharomyces
cerevisiae that is subject to natural telomeric silencing. In addition, we show
that telomeric silencing is not a general feature of the first ORFs located
adjacent to Telomere-Associated Sequences.
PMID- 10778748
TI - Comparative analysis of the mating-type loci from Neurospora crassa and Sordaria
macrospora: identification of novel transcribed ORFs.
AB - The mating-type locus controls mating and sexual development in filamentous
ascomycetes. In the heterothallic ascomycete Neurospora crassa, the genes that
confer mating behavior comprise dissimilar DNA sequences (idiomorphs) in the mat
a and mat A mating partners. In the homothallic fungus Sordaria macrospora,
sequences corresponding to both idiomorphs are located contiguously in the mating
type locus, which contains one chimeric gene, Smt A-3, that includes sequences
which are similar to sequences found at the mat A and mat a mating-type
idiomorphs in N. crassa. In this study, we describe the comparative
transcriptional analysis of the chimeric mating-type region of S. macrospora and
the corresponding region of the N. crassa mat a idiomorph. By means of RT-PCR
experiments, we identified novel intervening sequences in the mating-type loci of
both ascomycetes and, hence, concluded that an additional ORF, encoding a
putative polypeptide of 79 amino acids, is present in the N. crassa mat a
idiomorph. Furthermore, our analysis revealed co-transcription of the novel gene
with the mat a-1 gene in N. crassa. The same mode of transcription was found in
the corresponding mating-type region of S. macrospora, where the chimeric Smt A-3
gene is co-transcribed with the mat a-specific Smt a-1 gene. Analysis of a Smt A
3 cDNA revealed optional splicing of two introns. We believe that this is the
first report of co-transcription of protein-encoding nuclear genes in filamentous
fungi. Possible functions of the novel ORFs in regulating mating-type gene
expression are discussed.
PMID- 10778749
TI - Tagging of a nitrogen pathway-specific regulator gene in Tolypocladium inflatum
by the transposon Restless.
AB - Restless is an endogenous hAT transposon found in the cyclosporin-producing
fungus Tolypocladium inflatum. This element is present in about 15 copies in a
particular strain (ATCC34921) which was used for successful gene tagging. We have
isolated a T. inflatum mutant with a defect in nitrogen metabolism. This mutant
carries a copy of the Restless element in a gene encoding a C6 zinc-finger
protein. The deduced amino acid sequence of the gene product shows a significant
similarity to the NIT4 protein of Neurospora crassa, which is a regulator of
nitrogen metabolism. The wild-type T. inflatum gene was shown to complement a nit
4 mutant of N. crassa. From these data, we conclude that the T. inflatum gene
also encodes a regulator of nitrogen metabolism, which was named tnir1
(Tolypocladium nitrogen regulator 1). To the best of our knowledge, this is the
first fungal gene to be identified by transposon-directed gene tagging. A general
method for gene tagging using an endogenous fungal transposon is presented.
PMID- 10778750
TI - Overexpression of Arabidopsis thaliana SKP1 homologues in yeast inactivates the
Mig1 repressor by destabilising the F-box protein Grr1.
AB - The timed destruction of cell cycle regulatory proteins is of key importance in
controlling cell cycle progression in eukaryotes. Recently, Skp1 from yeast
(Saccharomyces cerevisiae) was shown to play an important role in the ubiquitin
mediated proteolysis of these proteins via the Skp1-Cdc53-F-box (SCF) pathway.
Here we describe the fortuitous cloning of cDNAs for two Skp1 homologues from the
plant Arabidopsis thaliana on account of their ability to activate reporter gene
expression in yeast directed by the cyt-1 element from the promoter of the
Agrobacterium tumefaciens T-cyt gene, which is essential for expression of the
gene in plants. This element is strikingly similar in sequence to the binding
site for the yeast Migl protein, a transcriptional repressor of genes involved in
the utilisation of carbohydrates other than glucose. We report that Mig1 protein
binds to the cyt-1 element with similar specificity as a previously described
plant nuclear protein factor, and that the cyt-1 element is a target for an
unknown yeast transcriptional activator when Mig1 itself is inactivated.
Interestingly, our data further indicate that A. thaliana Skp1 inactivates Mig1
by destabilising the yeast F-box protein Grr1, which is required for cyclin
degradation and is thus involved in control of the cell cycle, and for glucose
regulated gene repression. Our results suggest that the plant counterpart of
yeast Skp1 is probably also instrumental in ubiquitin-mediated proteolysis of
specific proteins via an SCF-like pathway.
PMID- 10778751
TI - The effects of transcription and RNA processing on the initiation of chloroplast
DNA replication in Chlamydomonas reinhardtii.
AB - In Chlamydomonas reinhardtii, the origin for chloroplast DNA replication, Ori A,
overlaps the coding region for the chloroplast ribosomal protein Rpl16. In an in
vitro DNA replication system that uses cloned Ori A as template, alteration of
transcription across rpl16 affects replication activity. S1 nuclease protection
mapping of cellular RNA derived from this region revealed multiple 5' and 3'
ends, and several 3' ends were mapped within mini Ori A (224 bp), the core region
for replication initiation. We also demonstrated that the protein fraction used
in the in vitro DNA replication system contained an RNA processing activity
responsible for the generation of multiple 3' ends. The 3' ends of some of the
processed RNA species coincided with those of the cellular transcripts.
Initiation of DNA replication in the in vitro system changed the abundance of
some of the processed RNA species, and the S1 nuclease protection pattern
generated by the 3' ends now mimicked that of the in vivo transcripts. We also
monitored the pattern of 3' ends in cellular transcripts from the rpl16 region
during gametogenesis--when the chloroplast DNA is under-replicated--and detected
a change in transcript abundance that correlated with that seen in the in vitro
study. Measurements of the template activity of mutants with targeted sequences
change near the sites of processing also supported the notion that the processed
transcripts play an important role in DNA replication.
PMID- 10778752
TI - An AFLP marker that differentiates biotypes of the Asian rice gall midge
(Orseolia oryzae, Wood-Mason) is sex-linked and also linked to avirulence.
AB - In an attempt to identify a specific marker for biotype 2 of the Asian rice gall
midge (Orseolia oryzae, Wood-Mason), we used AFLP (amplified fragment length
polymorphism) fingerprinting. We identified an AFLP marker that is specifically
amplified in biotypes 1, 2 and 5 of the rice gall midge, but not in biotype 4.
Biotypes 1, 2 and 5 are avirulent to hosts bearing the Gm2 resistance gene (found
in rice variety Phalguna), whereas biotype 4 is virulent to Gm2. Based on the
sequence of this AFLP marker, SCAR (sequence characterized amplified region)
primers were designed and used in combination with previously developed SCAR
primers to distinguish effectively all five biotypes in a multiplex PCR-based
assay. The inheritance pattern of this marker in the progenies of inter-biotype
crosses between biotypes 1, 2 and 4 shows that the marker can be amplified by PCR
from all F1 females, irrespective of the biotype status of their parents.
However, the marker is present only in those male progenies whose mother was of a
Gm2 avirulent biotype. The specific amplification of this marker in the avirulent
biotypes and its pattern of inheritance show that avirulence with respect to
carriers of the Gm2 gene in rice gall midge is sex-linked.
PMID- 10778753
TI - hobo-induced rearrangements are responsible for mutation bursts at the yellow
locus in a natural population of Drosophila melanogaster.
AB - In 1981 recurrent local bursts of mutability of the yellow gene were observed in
a natural population of Drosophila melanogaster from Uman' (Ukraine). A series of
y2-like mutations in the yellow gene were recovered during the period 1982 to
1991. Most of the mutants display the y2-phenotype, i.e. mutant yellow color of
wings and body cuticle. Ninety-nine y2 mutants were shown to be generated by an
inversion that occurred between two hobo elements, one located 129 bp from the
start site of yellow transcription, and the other in the distal telomere region.
The y2 phenotype was caused by the separation of the body and wing enhancers from
the transcription unit. Many of the y2-like alleles were highly unstable and
reverted to y+, which again, gave rise to y2-like mutants. We found that the y2-
>y+-->y2 transitions were generated by repeated inversions between the two hobo
elements mentioned. The y2 and y+ alleles lost their instability after deletion
of the hobo element present at the tip of the X chromosome.
PMID- 10778754
TI - Nitric oxide reduction, the last step in denitrification by Fusarium oxysporum,
is obligatorily mediated by cytochrome P450nor.
AB - The involvement of cytochrome P450nor (P450nor) is the most striking feature of
the fungal denitrifying system, and has never been shown in bacterial systems. To
establish the physiological significance of the P450nor, we constructed and
investigated mutants of Fusarium oxysporum that lacked the gene for P450nor. We
mutated the gene by targeted integration of a disrupted gene into the chromosome
of F. oxysporum. The mutants were shown to contain neither P450nor protein nor
nitric oxide (NO) reductase (Nor) activity, implying that they are indeed
deficient in P450nor. These mutants had apparently lost the denitrifying activity
and failed to evolve nitrous oxide (N2O) upon incubation under oxygen-limiting
conditions in the presence of nitrate. Their mycelia exhibited normal levels of
dissimilatory nitrite reductase (Nir) activity and were able to evolve NO under
these conditions. The promoter region of the P450nor gene was fused to lacZ and
introduced into the wild-type strain of F. oxysporum. The transformed strain
produced beta-galactosidase under denitrifying conditions as efficiently as the
wild type does P450nor. These results represent unequivocal genetic evidence that
P450nor is essential for the reduction of NO to N2O, the last step in
denitrification by F. oxysporum.
PMID- 10778755
TI - Expression of the hemolysin operon in Escherichia coli is modulated by a nucleoid
protein complex that includes the proteins Hha and H-NS.
AB - The Escherichia coli protein Hha is a temperature- and osmolarity-dependent
modulator of the expression of the hemolysin operon. The Hha protein was purified
and its DNA-binding properties analyzed. Hha binds in a non-specific manner
throughout the upstream regulatory region of the hemolysin operon in the
recombinant hemolytic plasmid pANN202-312. A search for interacting proteins
revealed that Hha interacts with H-NS. DNA-binding studies showed that, in vitro,
Hha and H-NS together form a complex with DNA that differs from those formed with
either protein alone. These data, together with the effects of hha and hns
mutations on the expression of the hemolysin genes, suggest that in vivo H-NS and
Hha form a nucleoid-protein complex that accounts for the thermo-osmotic
regulation of the hemolysin operon in E. coli.
PMID- 10778756
TI - Diverse response of rice and maize genes encoding homologs of WPK4, an SNF1
related protein kinase from wheat, to light, nutrients, low temperature and
cytokinins.
AB - The wheat gene WPK4 encodes a 56-kDa protein kinase that belongs to group 3 of
the SNF1-related protein kinase family (SnRK3), and is up-regulated by light and
cytokinins and down-regulated by sucrose. In order to determine whether or not
this particular regulation pattern is general among plant species, we isolated
and characterized homologous genes from rice and maize. Two rice genes, OsPK4 and
OsPK7, encode proteins comprising 508 and 520 amino acids, and show,
respectively, 75% and 76% sequence similarity to WPK4. OsPK4 and OsPK7 proteins
produced in Escherichia coli were able to phosphorylate themselves and myelin
basic proteins, the reaction requiring magnesium and/or manganese ions.
Transcripts of OsPK4 were detected in all tissues tested, and amounts were
increased upon illumination, nutrient deprivation and treatment with cytokinins.
In contrast, transcripts of OsPK7 were not found in any tissues except in mature
leaves at low levels, and did not accumulate under any of the stress conditions
examined. A maize gene, ZmPK4, encodes a protein with 518 amino acids that shows
74% similarity to WPK4. Its transcripts were constitutively expressed in all
tissues, regardless of light, nutrient and cytokinin status, but were increased
upon exposure to low temperature. These results indicate that, despite the
sequence similarity between their products, genes for SnRK3 proteins are
differentially regulated in response to environmental stimuli.
PMID- 10778757
TI - A point mutation at the Miniature1 seed locus reduces levels of the encoded
protein, but not its mRNA, in maize.
AB - We report here on the molecular nature of an EMS-induced mutant, mn1-89, a leaky
semidominant allele of the Miniature1 (Mn1) seed locus that encodes a seed
specific cell wall invertase, INCW2. The mn1-89 locus specifies normal levels of
the Incw2 transcript but extremely low levels (about 6% of normal) of the protein
and enzyme activity are expressed. Sequence analysis of Incw2 clones derived from
the parental Mn1 and the mutant genotypes shows a C to T transition in the mn1-89
allele, leading to a single amino acid alteration (proline to leucine) near the C
terminus of the mutant INCW2 protein. Although this change is not in the
catalytic domain, putative N-glycosylation sites, or the beta-fructosidase motif,
it does lie in a motif that is well conserved among all plant invertases and
related fructosyltransferases. On the basis of these genetic in planta data, we
believe we have identified a proline residue in a hitherto unknown GPFG motif as
critical for the stability of such proteins. The single base change (C to T) also
leads to the elimination of a BglI restriction site in the mutant allele. Indeed,
BglI restriction digests of genomic DNAs from mn1-89 and Mn1 genotypes show one
and two fragments, respectively. Sequence analysis of RT-PCR-derived endosperm
Incw clones from mn1-1 (the reference allele) seeds predict five amino acid
substitutions relative to Mn1. Whether or not these sequences are encoded by the
mn1-1 locus or another non-allelic Incw gene in the maize genome remains to be
elucidated.
PMID- 10778758
TI - Surgical strategies in colorectal cancer metastatic to the liver.
AB - Surgical resection remains a milestone in the treatment of colorectal metastases
to the liver. There is a distinct subset of patients who benefit from surgical
resection in terms of longer survival or definitive cure. The main effort of the
surgical oncological regards the safety of the procedure and the adequacy of the
recommendation. Many studies, some of them including multivariate analysis, have
shown the presence of prognostic determinants of long-term survival and
prognostic indexes of the outcome after hepatectomy. It is now accepted that
liver resection should be done when the complete excision of all demonstrable
tumor with clear resection margins is feasible. Major contra-indication is
represented by the presence of extra-hepatic intra-abdominal disease or of
unresectable lung metastatic deposits. There is a wide literature indicating that
in very selected patients liver reresection and multiorgan synchronous or
metachronous resections are beneficial. The role of neoadjuvant chemotherapy and
especially postoperative adjuvant local (intra-hepatic) and systemic chemotherapy
is promising and supported by recent multicenter randomised clinical trials.
PMID- 10778759
TI - Validation of the modified TNM-Izumi classification for hepatocellular carcinoma.
AB - AIMS AND BACKGROUND: The clinical value of the UICC TNM classification and the
Izumi TNM modification regarding prognosis after hepatic resection was evaluated.
METHODS: Between January 1993 and December 1998, survival and disease-free
survival were analyzed in 53 cirrhotic patients (40 males, 13 females; mean age,
65 years; range, 43-81) who underwent hepatic resection for HCC. RESULTS: The 1-,
3-, and 5-year overall survivals were: 89%, 54%, and 50%, with disease-free
survivals of 70%, 38%, and 28%, respectively. The difference between stages 1 and
2 or stages 3 and 4A using the UICC TNM classification was not significant with
respect to survival or disease-free survival. Conversely, the Izumi TNM
modification showed a significant difference between each stage with respect to
survival and disease-free survival. In a multivariate analysis the lack of
micro/macro vascular invasion was predictive of long-term outcome. CONCLUSIONS:
Our results show that the UICC TNM classification for hepatocellular carcinoma is
inadequate. The Izumi modified TNM staging system is superior in assessing
prognosis for surgical HCC patients.
PMID- 10778760
TI - Factors of risk for breast cancer influencing post-menopausal long-term hormone
replacement therapy.
AB - The advantages of hormone replacement therapy (HRT) are well documented in
contrasting the symptomatology of climacterium and in reducing morbidity and
mortality associated with coronary heart disease and osteoporotic fractures of
postmenopausal age. However, growing evidence points to increased breast cancer
risk in HRT long-term users, and the adverse effect would, obviously, overwhelm
any other benefit. At present, the risk/benefit ratio of HRT is an object of hot
debate, and we feel it necessary and urgent to select women who can safely
benefit from HRT and women whose risk of breast cancer can be perilously
increased by the raised hormonal levels related to HRT. We have reviewed studies
on the breast cancer risk in HRT users and data on the interaction between
steroid hormones and breast cancer. Reasoning that the outcome of mammary cancer
can be increased by hormonal overstimulation of the breast, we have focused on
those factors of risk that could be further enhanced by the exogenous hormonal
stimulus of HRT, so as to cause a further significant increase in the risk of
breast cancer. We conclude that some biologic and clinical markers, namely
android obesity, bone density, mammographic density, androgen and estrogen
circulating levels, alcohol consumption, benign breast disease, and familiarity,
should be carefully considered before prescribing long-term HRT. Our analysis
suggests that HRT could increase the risk of breast cancer and useless in
preventing coronary heart disease and osteoporotic fractures when administered in
women with positivity for one or more of these markers.
PMID- 10778761
TI - Prognostic significance of anemia and role of erythropoietin in radiation
therapy.
AB - Anemia represents a common finding in cancer patients, especially at an advanced
stage. Anemia has an impact on the quality of life and at the same time seems to
markedly limit the disease control that can be achieved with radiotherapy. The
results of a series of clinical studies published in the last decade allow some
general observations: 1. the administration of erythropoietin, especially if
associated to ferrous sulfate is able to increase hemoglobulin levels in cancer
patients undergoing radiation therapy (combined with concomitant chemotherapy);
2. erythropoietin stimulation of hemoglobin in anemia decreases the need for
blood transfusion in cancer patients; 3. tumor response to radiation therapy
appears to be enhanced by erythropoietin-induced hemoglobulin increase. Further
clinical studies are required for assessment of indications, identification of
optimal administration modalities, cost-analysis of this promising therapy for
patients undergoing radiation therapy.
PMID- 10778762
TI - Hormonal profiles and estrogen receptors in Egyptian female breast cancer
patients.
AB - AIMS AND BACKGROUND: Hormones are considered to be an important factor in the
etiology of breast cancer. Serum hormonal profiles of premenopausal and
postmenopausal breast cancer patients as well as estrogen receptor (ER)
concentrations in breast cancer tissues were examined in an attempt to establish
a possible association between hormones and breast cancer risk and to elucidate
the biological features of the disease among Egyptian female patients. METHODS:
Levels of estradiol (E2), testosterone (T), progesterone (P), LH, FSH, prolactin,
T3, T4 and TSH were measured by highly specific radioimmunoassays in the sera of
women with breast cancer and compared to those of control subjects. ER
concentrations in breast tumor tissues were measured using 125I-radioreceptor
assay. RESULTS: Levels of T and prolactin showed a significant increase in both
premenopausal and postmenopausal patients. E2 and P levels were significantly
increased in follicular premenopausal and postmenopausal patients. Luteal E2
showed non-significant changes, whereas the luteal P level was significantly
decreased. No significant alterations were found in the levels of serum LH, FSH,
T3, T4 and TSH either in premenopausal or postmenopausal patients. Higher levels
of ER were found in the tumors of postmenopausal than in those of premenopausal
patients. A positive correlation was found between levels of ER and age of the
patients (r = 0.35), whereas a negative correlation was observed between ER and
serum E2 (r = -0.26). CONCLUSIONS: This study provides evidence of an association
between high levels of serum E2 and T and increased risk of breast cancer in
postmenopausal women. Abnormalities in serum P and prolactin are probably
associated with a breast cancer risk and ER may be considered as a biochemical
marker for breast cancer development.
PMID- 10778763
TI - Mutual predictive value of c-erbB-2 overexpression and various prognostic factors
in ductal invasive breast carcinoma.
AB - AIMS AND BACKGROUND: Breast carcinoma is a heterogeneous disease, the prognosis
of which correlates with various prognostic factors. The aim of this study was to
assess the prognostic significance of c-erbB-2 overexpression in breast carcinoma
patients in association with other known prognostic factors. METHODS & STUDY
DESIGN: The relationship between immunohistochemical expression of the c-erbB-2
oncoprotein and various established prognostic factors such as tumor size,
axillary node status, estrogen and progesterone receptor status, DNA ploidy,
proliferation index, cathepsin D expression and histological grade in invasive
ductal breast carcinoma is presented in this study. RESULTS: Of the 93 ductal
invasive carcinomas 22 (23.7%) were grade I, 51 (54.8%) grade II, and 20 (21.5%)
grade III, and the majority (78: 83.9%) were 2-5 cm in diameter. Tumor metastases
were identified in one or more lymph nodes in 55 (59.1%) patients, the remaining
38 (40.9%) patients being lymph node negative. According to the DNA histograms 40
(43.0%) tumors were aneuploid and 53 (57.0%) were diploid, and the majority of
tumors had more than 4% of cells in the S phase of the cell cycle (83.9%).
Expression of c-erbB-2 as shown by immunohistochemical intense membrane staining
was present in 49 (52.7%) tumors. Cathepsin D-positive cytoplasmic granular
staining and cathepsin D-positive stromal macrophages were found in 60 (64.5%)
and 72 (77.4%) tumors, respectively. Univariate analysis showed that overall
survival correlated significantly with axillary lymph node involvement and with
estrogen and progesterone receptor status for each of the receptors separately
and for their coexpression, and only marginally with c-erbB-2 overexpression. In
mulitivariate analysis only axillary lymph node metastases and coexpression of
estrogen and progesterone receptors were found to be independent and significant
prognostic factors. CONCLUSIONS: When patients were stratified according to c
erbB-2 expression it was shown that those with c-erbB-2 overexpression and grade
II tumors, tumor size greater than 2 cm, high content of aneuploid cells and
cathepsin D-positive stromal macrophages had a shorter long-term survival than c
erbB-2 negative patients.
PMID- 10778764
TI - A randomized open-label parallel-group study comparing ondansetron with
ondansetron plus dexamethasone in patients with metastatic breast cancer
receiving high-dose epirubicin. A Hellenic Cooperative Oncology Group study.
AB - AIMS AND BACKGROUND: The purpose of this multicenter randomized, open-label,
parallel-group study was to assess whether the addition of low-dose dexamethasone
to ondansetron results in improved control of chemotherapy-induced emesis in
patients undergoing first-line chemotherapy with high-dose epirubicin. METHODS &
STUDY DESIGN: Patients were randomized to receive either 24 mg of ondansetron or
24 mg of ondansetron plus 8 mg of dexamethasone administered as an intravenous
infusion 30 minutes prior to administration of chemotherapy. Both groups of
patients received 8 mg of ondansetron given orally from day 2 to 5 two times
daily. Fifty-three patients received ondansetron and 50 received ondansetron plus
dexamethasone. The patients recorded nausea and the number of vomits and retches
daily on diary cards. RESULTS: Significantly more patients in the ondansetron
plus dexamethasone group experienced neither vomiting nor retching during the
first day of the first course of chemotherapy compared to those receiving
ondansetron alone (79.6% vs 53.8%, P = 0.0062). Furthermore, there was a trend in
favor of ondansetron plus dexamethasone in the control of nausea. There was no
statistically significant difference between ondansetron plus dexamethasone
versus ondansetron alone in protecting patients from emesis between days 2 and 5
of the first course of chemotherapy (66.7% vs 62.7%, P = 0.68). This was probably
due to the small sample size. Ondansetron was well tolerated, with 15 patients
(15%) reporting adverse events such as headache or constipation. CONCLUSIONS: It
appears that ondansetron given intravenously in combination with dexamethasone is
more effective than ondansetron alone in the control of acute emesis in patients
undergoing their first course of chemotherapy with high-dose epirubicin. No
difference between the regimens was found with regard to nausea and delayed
emesis control.
PMID- 10778765
TI - Continuous infusion fluorouracil in the management of advanced breast cancer: a
phase II study.
AB - AIMS AND BACKGROUND: The evaluation of unconventional schedules of well-known
drugs represents a promising avenue in the search for new regimens with a better
therapeutic index in metastatic breast cancer. In particular, protracted
continuous infusion (PCI) of 5-fluorouracil (5-FU) has yielded interesting
results in gastrointestinal malignancies and in breast cancer. METHODS: From
March 1996 30 consecutive patients with heavily pretreated breast cancer were
treated with PCI 5-FU at a daily dose of 250 mg/m2 by means of disposable
elastomeric pumps until progression or toxicity. The median age was 54 years
(range, 28-71) and median performance status was 1 (range, 0-3). All patients but
four were pretreated with anthracycline-containing regimens or taxanes; the
median number of chemotherapy lines was 3 (range, 2-4). Metastatic sites were
predominantly visceral in 60% of the patient population. RESULTS: All 30 patients
were evaluable for response and toxicity. The median duration of PCI was 20 weeks
(range, 2-36 weeks). Two complete responses (7%) and eight partial remissions
(26%) were observed, giving an overall response rate of 33%. The median duration
of response was six months (range, 4-9 months). Stabilization was observed in
seven patients (23%) with a median duration of seven months (range, 3-9 months).
The main toxic effects were grade I-II mucositis and hematologic toxicity, while
grade 3 hand-foot syndrome was observed in eight patients (27%). CONCLUSIONS:
This study confirms the efficacy and safety of 5-FU at this dosage and schedule
in heavily pretreated women with advanced breast cancer. In order to improve on
these results further studies are needed in a less advanced stage of the disease
and together with other active drugs.
PMID- 10778767
TI - Cell kinetics analysis in patients affected by squamous cell carcinoma of the
head and neck treated with primary surgery and adjuvant radiotherapy.
AB - BACKGROUND: The increasing complexity of management strategies for patients with
head and neck squamous cell carcinoma (HN-SCC) calls for the investigation of new
objective prognostic parameters to subdivide patients according to the tumor's
biological aggressiveness. METHODS: We evaluated in 35 HN-SCC patients the
pretreatment cell kinetics parameters and DNA ploidy after in vivo infusion of
bromodeoxyuridine and flow cytometric analysis. Patients were treated with
radical surgery followed by conventional radiation therapy. Locoregional control
data are available for follow-up times above five years. RESULTS: We found that
the likelihood of locoregional control for patients with rapidly proliferating HN
SCC characterized by a short potential doubling time (Tpot <5 days) was
significantly smaller than for HN-SCC patients with slow tumor proliferation
(Tpot >5 days). Moreover, when patients were stratified according to DNA ploidy
and Tpot value, we found that the locoregional failure rate for rapidly
proliferating tumors was significantly higher for diploid HN-SCCs than for
aneuploid HN-SCCs. CONCLUSION: The present data suggest that patients with
resectable HN-SCC characterized by fast growth might have a worse prognosis after
surgery and adjuvant conventional radiotherapy and might benefit from more
aggressive radiotherapeutic modalities.
PMID- 10778766
TI - Tumor infiltrating lymphocytes and continuous infusion interleukin-2 after
metastasectomy in 61 patients with melanoma, colorectal and renal carcinoma.
AB - AIMS AND BACKGROUND: Adoptive immunotherapy with tumor infiltrating lymphocyte
(TIL) reinfusion plus continuous interleukin-2 (IL-2) infusion could represent an
innovative way of treating immunogenic tumors. This study therefore recruited
melanoma, colorectal and renal carcinoma patients whose metastases had been
surgically removed. STUDY DESIGN: The treatment was initially given to 22
patients with advanced disease and more recently to 39 disease-free (DF) patients
after radical metastasectomy. The latter group was selected in view of a
theoretically better lymphocyte/tumor cell ratio and with the aim to improve
disease-free and overall survival (DFS-OS) in very high risk patients. The
starting IL-2 dose was 12 MIU/day (West's schedule); doses were modulated on the
bases of toxicity parameters. Even though patients received different total
amounts of IL-2, all of them completed the treatment. RESULTS: The treatment was
offered to 22 advanced-stage cancer patients (12 melanomas, 9 colorectal
carcinomas, 1 kidney carcinoma). Few and short stabilizations were observed with
a median survival of 12 months (range, 3-29). Subsequently, another 39 patients
were treated in an adjuvant setting after radical metastasectomy (18 melanomas,
19 colorectal carcinomas, 2 kidney cancers). Eleven out of 17 DF melanoma
patients (64.7%) are still free of disease after a median of 37+ months (range,
5+ - 69+). In the group of DF colorectal cancer patients eight (44.4%) are still
DF after a median of 21+ months (range, 7+ - 67+ months). One of the two patients
with kidney cancer is still DF after 28+ months. Two patients (1 melanoma and 1
colorectal cancer) had just been treated and were therefore not evaluable. Severe
toxicity occurred in three cases but was rapidly resolved. There was a great
diversity in IL-2 doses administered; comparison of the total IL-2 dose
administered between the patients who are still DF and those who progressed
revealed no difference between the two groups of colorectal cancer patients,
whereas melanoma patients who progressed received an average IL-2 dose of 6.5
MIU/day versus 15.8 MIU/day in DF patients. No differences were observed in any
of the groups between the number of TILs reinfused and clinical response.
CONCLUSIONS: The study is still ongoing; it has been decided to focus on DF
melanoma patients after radical metastasectomy, for whom the data seem to be
encouraging. Further endpoints of the study are the role of IL-2 dosage in the
adjuvant setting, and the possibility to make correlations between biological
parameters and clinical results.
PMID- 10778768
TI - Benefit of adjuvant radiotherapy in surgically staged stage I-II endometrial
carcinoma.
AB - AIMS AND BACKGROUND: This study was performed to determine the treatment outcomes
and patterns of failure following external beam therapy in patients with
pathological stage I-II endometrial carcinoma. STUDY DESIGN: Eighty-three
patients with stage I-II endometrial carcinoma surgically staged who were found
to have high risk factors and who received postoperative radiation therapy are
the subject of this report. High risk factors were: histologic grade II-III,
depth of myometrial invasion (DMI) > or =1/2, stage II, poor prognostic histology
(clear cell, papillary serous cell) and lymphovascular invasion. RESULTS:
Recurrences were observed in six patients. The recurrences were located in the
vagina (1), lung (2), liver (1), and paraaortic lymph nodes (1). Five of the six
recurrences were stage IC and II. The overall survival (OS), cause-specific
survival (CSS) and disease-free survival (DFS) at five years were 82.9%, 85.0%
and 81.3%, respectively. DMI, grade, age and cervical stromal invasion had a
significant impact on CSS. CONCLUSION: Adjuvant radiotherapy decreases the rate
of relapse in pathologically staged high-risk stage I-II endometrial carcinoma
patients. After reviewing the other studies on this subject we conclude that
vaginal cuff brachytherapy alone could be used in stage IA grade III and stage IB
grade I-II patients because the recurrence rate is low; pelvic radiotherapy +
vaginal cuff brachytherapy should be used for stage IC-II disease. Distant
metastases occurred in five of our patients and represent a significant type of
failure.
PMID- 10778769
TI - Characterization of tumor-associated antigens on human oral squamous cell
carcinomas using monoclonal antibody 3F8E3.
AB - Tumor associated antigen (TAA) on oral squamous cell carcinoma (SCC) was
characterized using the monoclonal antibody (MAb) 3F8E3. Flow cytometric analysis
revealed a varying degree of reactivity of MAb 3F8E3 to TAA on oral tumor cells.
Pretreatment of SCC cells with pronase and trypsin annulled the reactivity of MAb
3F8E3. Sodium metaperiodate (NaIO4) and neuraminidase marginally enhanced the
binding of 3F8E3 on oral SCC cells. The studies indicate that the TAA recognized
by MAb 3F8E3 on oral tumors is a protein moiety. On Western blotting MAb 3F8E3
showed reactivity to proteins with a molecular weight of 60-66 kDa on oral tumor
lysates. MAb 3F8E3 reacted strongly to recombinant human hsp60 and 70 in ELISA.
The results suggest that MAb 3F8E3 may react to an epitope expressed on a family
of heat shock proteins.
PMID- 10778770
TI - Association between cutaneous melanoma and neurofibromatosis type 1: analysis of
three clinical cases and review of the literature.
AB - The authors report a rare association between cutaneous melanoma and Von
Recklinghausen's disease (NF-1) and analyze the possible meaning of this
occurrence. Various types of tumors have been associated with NF-1, in particular
those of neuroectodermal origin, such as malignant peripheral nerve sheath tumors
(MPNST) and phaeochromocytoma. The development of malignant melanoma in NF-1
patients is rare. Data from the literature is enable to demonstrate an increased
incidence of cutaneous melanoma in patients with neurofibromatosis but the
association of these two disorders seems reasonable in theory, as both are
abnormalities of a neural crest origin. The cases described may represent not
only a clinical report of two rarely associated disorders, but may also confirm
the biological mechanisms responsible for these infrequent diseases.
PMID- 10778771
TI - Mesenchymal chondrosarcoma of the sacrum: a case report and review of the
literature.
AB - The authors present a case of mesenchymal chondrosarcoma located in the sacrum of
a 23-year-old patient treated with radiotherapy and chemotherapy. A review of the
literature on the topic is also reported.
PMID- 10778772
TI - Chondrosarcoma of the larynx. Case report and review of the literature.
AB - Chondrosarcoma of the larynx is a rare tumor; worldwide only about 250-300 cases
have been described in the literature. We present a clinical case of laryngeal
chondrosarcoma manifesting as a swollen mass of 10 x 7 x 6 cm in the infrahyoid
and left lateral cervical region. The patient underwent total laryngectomy,
thyroidectomy and bilateral neck dissection. A review of the literature on this
disease is also reported.
PMID- 10778773
TI - Carcinosarcoma of the lung: a case report.
AB - The clinical and pathological data of a single case of carcinosarcoma of the lung
observed in the period from 1978 to 1998 were reviewed. The diagnosis was based
on immunohistochemical examination of the surgical specimen after a lower left
lobectomy. The patient was given adjuvant chemotherapy. The local recurrence
showed only sarcomatous features. The characteristics of this rare tumor are
discussed in this case report.
PMID- 10778774
TI - Rectal neurogenic sarcoma: case report and review of the literature.
AB - A neurogenic sarcoma without NF-1 was discovered in a 73-year-old woman in the
anorectal region, an unusual site for these tumors. The tumor was of high-grade
malignancy and deeply located with mesorectal infiltration; it did not originate
from a major nerve. We presume an origin from less differentiated neural crest
cells and present a review of the literature on the best treatment for these
neoplasms.
PMID- 10778775
TI - Metastatic renal cell carcinoma to the head and neck area.
AB - AIMS AND BACKGROUND: Metastases of renal cell carcinoma to the head and neck are
rare. We report on three cases with tumor spread to this area (nasal cavity,
tongue and larynx) and present a review of the literature. PATIENTS: The first
patient presented with lung and nasal cavity metastases five years after renal
tumor resection. In patient 2 the diagnosis of primary renal carcinoma and lung
and tongue metastases was concomitant. In case 3 a primary kidney tumor was not
suspected until radical resection of a tongue lesion was performed. RESULTS: The
first two patients received radiation therapy. They had been previously treated
with interleukin + interferon and vinblastine + interleukin 2 and achieved a
survival of 14 and 16 months, respectively. The third patient has not been given
any treatment to date (apart from surgery) and remains asymptomatic four years
after diagnosis. CONCLUSIONS: In patients with cell carcinoma the occurrence of
lesions in the head and neck area may suggest metastases. In some cases they may
precede the diagnosis of a renal tumor and mimic a primary head and neck tumor;
otolaryngologists should be aware of this possibility. An individualized
treatment approach is recommended. In the case of solitary metastases a surgical
excision should be performed as palliation, if not cure.
PMID- 10778776
TI - Primary carcinoid tumor of the ovary: report of an unusual case.
AB - Carcinoid tumors are endocrine malignancies that are often associated with a
characteristic syndrome, the malignant carcinoid syndrome, which is most common
in patients with small bowel tumors and liver metastases. In the rare instances
when the syndrome is present without liver metastases the primary tumor is
usually localized to the bronchus or ovary and secretes hormones directly into
the systemic circulation. About two thirds of patients with carcinoid syndrome
have evidence of carcinoid heart disease. We report on a case of a primary
ovarian carcinoid tumor with an unusual clinical presentation.
PMID- 10778777
TI - Colon cancer in pregnancy: report of a case and review of the literature.
AB - Most colon cancer cases occur in patients over 50 years of age, although about 3%
of colorectal cancer patients are younger than 40. During pregnancy the incidence
of this neoplasm is estimated to be 0.002%. To date only 32 cases of colonic
cancer arising above the peritoneal reflection during pregnancy have been
described in the literature. We report another such case, stressing the need for
constant alertness on the part of physicians in the presence of abdominal pain
and/or distension, a palpable abdominal mass, rectal bleeding and/or weight loss
during pregnancy. In fact, the reportedly poorer prognosis of this cancer in
pregnant patients is mainly due to the fact that the initial symptoms of the
malignancy are usually attributed by the patient, but also by physicians, to
normal pregnancy.
PMID- 10778779
TI - [Therapeutic strategies in oncology and quality of life: Echoes from 2 recent
congresses. IX National Congress of the Italian Society of Palliative Therapy,
Rome, 17-20 November 1999. XXV National Congress of the Tumor Italian Society
(Societa Italiana Tumori), Sorrento, 17-21 November 1999].
PMID- 10778778
TI - Lethal midline granuloma starting as granuloma laryngis.
AB - We report a case of lethal midline granuloma in a 34-year-old male patient. The
patient was referred to our hospital because of long-lasting hoarseness. He was
treated for granuloma laryngis. After two years nasal obstruction developed
followed by ulceration of the hard palate and destruction of part of the nose and
the upper lip. A biopsy demonstrated polymorphic infiltrate consisting of small
lymphocytes, plasma cells, macrophages, atypical lymphoid cells and eosinophils.
Radiotherapy was very effective and led to long-term remission. The different
etiological aspects of this syndrome are discussed.
PMID- 10778780
TI - Environmental enrichment of laboratory animals used in regulatory toxicology
studies.
AB - There is a wealth of information in the published literature which describes a
multitude of approaches to enriching the environment of laboratory animals. This
paper attempts to review the various methods of enrichment through social
contact, enhancement of the environment and diet, and improvements in husbandry.
It attempts to place the various enrichment initiatives within the context of a
laboratory which conducts regulatory toxicology, describes some of the
experiences in the author's own laboratory and attempts to highlight those ideas
which might prove practical to implement in the future. The aim is to demonstrate
that a creative approach to environmental enrichment is indeed compatible with
regulatory toxicology. It is hoped that this will encourage those responsible for
the care and welfare of animals in such a laboratory to challenge historical
practices and include environmental enrichment as a fundamental necessity of
study design.
PMID- 10778781
TI - Interference of pain control employing opioids in in vivo immunological
experiments.
AB - Pain control (PC) in laboratory animals is supported by ethical as well as
methodological considerations, aimed at preventing an interfering reduction in
food and water intake and normalizing stress hormone levels. However, little is
known about the immunomodulatory attributes of analgesics, which putatively
prevents the routine implementation of PC in immunological research. In an
established murine model of endotoxemia we investigated the immunomodulatory
properties of common clinical analgesics (the opioids fentanyl and
buprenorphine). Additionally, a literature study was conducted to investigate the
frequency of PC in laboratory animals used for immunological experimentation. In
line with various reports, we observed interactions between the opioid analgesics
and the immune system that altered the outcome of performed in vivo immunological
experiments. Of 100 evaluated publications, none mentioned the use of PC,
indicating its uncommon implementation. In conclusion, more studies on the
interactions between the immune system and analgesics are needed to establish
better criteria for adequate implementation. Finally, we propose that
methodological sections in scientific journals should clearly document whether or
not PC was employed. If PC is not used, the reason for not using it should be
stated.
PMID- 10778782
TI - The generation of monoclonal antibodies in mice: influence of adjuvants on the
immune response, fusion efficiency and distress.
AB - The objective of this study was to find a reliable alternative to Freund's
adjuvant in order to reduce the distress imposed on the animals without impairing
the fusion efficiency for immune-positive clones. For this purpose several
commercially available adjuvants and adjuvant formulations representing different
classes of molecules were compared. Humoral responses and animals' distress
evaluated by clinical assessment and histopathological examinations were
investigated and compared to fusion efficiencies. In a first set of experiments
seven adjuvants were tested essentially to determine their potential to induce
distress. Poly(A).poly(U) and GERBU were selected for further investigations due
to their low overall toxicity. They were combined with five different antigens
and compared to the classic Freund's adjuvant system (CFA/IFA) and to control
immunizations without adjuvant. The results showed that adjuvants of very low
toxicity could induce a high fusion efficiency. According to a standardized
immunization protocol, GERBU induced polyclonal titres similar to Freund's
whereas animals treated with poly(A).poly(U) did not attain titres higher than
mice immunized with antigen in saline. Poly(A).poly(U) however, exhibited the
best fusion efficiency, Freund and GERBU were slightly less efficient. Therefore
poly(A).poly(U) and GERBU may serve as valuable alternatives to Freund's adjuvant
for generating monoclonal antibodies. Furthermore, these two adjuvants are very
easy to use.
PMID- 10778783
TI - Allometric comparison of recommendations of minimum floor areas for laboratory
animals.
AB - The recommendations for minimum floor area given in the European Convention for
the Protection of Vertebrate Animals used for Experimental and other Scientific
Purposes (1986), as well as in the Publication on the Planning and Structure of
Animal Facilities for Institutes Performing Animal Experiments of the Society for
Laboratory Animal Science (GV-SOLAS 1989), are plotted in a double logarithmic
system in order to get an allometric function of recommended floor area to body
weight. Both recommendations correspond very well with the so-called metabolic
body weight seen at the allometric exponent of 0.73 and 0.70 respectively. Thus
the recommendations in general attribute the floor space according to the
metabolic body weight of the animal. Nevertheless, despite this general rule,
some species are recommended less space than others when measured on this
allometric scale. Thus it must be questioned why, for example, rabbits, chicken
and pigs are recommended less space than other species. The general allometric
measure seems at least to be a good scale for the comparison of recommended floor
space, and for the discussion of species-specific needs for more or less space.
PMID- 10778784
TI - Electrophysiology and pathology evaluation of the Yucatan pig as a non-rodent
animal model for regulatory and mechanistic toxicology studies.
AB - Six male and six female Yucatan pigs were utilized to investigate the feasibility
of this species as a non-rodent model for routine regulatory and mechanistic
toxicology studies. This study evaluated disease surveillance and computerized
electrophysiology, along with possible gross and micropathology changes. Two pigs
were used as sentinel animals to evaluate the microbiological status of the
vendor upon arrival; the other pigs were maintained as biomonitors and to provide
baseline clinical chemistry, urinalysis, pathology and electrophysiology data.
The electrophysiology tests conducted included electrocardiography (ECG),
electroretinography (ERG) and quantitative electroencephalography (qEEG), which
achieved consistent baseline values with acceptable intrasubject variation.
Tissue cholinesterase and histochemical staining were done to determine their
suitability for testing cholinesterase compounds. Evaluation of the serum
chemistry profile demonstrated increased CPK and LDH, which was likely associated
with slight haemolysis or minor subclinical muscle stress during handling. There
were no additional clinical chemistry changes or findings in haematology,
urinalysis parameters or gross pathology. Micropathology found an absence of
background lesions which would interfere with routine toxicology studies, except
for a mild rhinitis. The aetiological agent was identified by electron microscopy
as being consistent with inclusion body rhinitis of swine, previously unreported
in miniature swine. This would most notably interfere with inhalation studies.
The anatomical and physiological similarities of the Yucatan pig, along with its
ability to accept the performance of electrophysiology tests allow this species
to be considered as a suitable model for organ system testing in toxicology
studies.
PMID- 10778785
TI - Beta-adrenoceptor inhibition for induction of acute cardiac failure in pigs.
AB - For the testing of heart assist devices most animal models of acute cardiac
failure that are usually used show certain disadvantages. We therefore developed
a new method using the beta-adrenoceptor antagonist carazolol. We administered a
bolus injection of 1 mg/kg followed by a continuous infusion of 1 mg/kg/h in
adult German 'Landrasse' pigs. Blood pressure, heart rate, cardiac output and
maximum left ventricular pressure rise time showed a significant (P < 0.05)
reduction of the control value varying between 40% and 59%. The method is
suitable for the testing of surgical approaches in heart failure.
PMID- 10778786
TI - Superovulation in vesper mice, Calomys laucha--an important biomedical model for
hantavirus and arenavirus (Rodentia-Sigmodontinae).
AB - Sigmodontine rodents are poorly studied and have not received much attention as a
reproductive model. Renewed interest in the South American rodents has been
stimulated by their link to endemic diseases that are transmitted to man. Calomys
laucha acts as a reservoir of two dangerous viruses: an arenavirus named 'Junin
virus', the aetiological agent of Argentinian haemorrhagic fever, and the
hantavirus, both of which constitute serious sanitary problems. The aim of this
study was to establish suitable conditions to superovulate the vesper mouse,
Calomys laucha. We examined the hormonal doses, the time interval between
hormones, the time-course of ovulation, and the effect of female age on the
response to exogenous hormone administration. Female mice were injected with 5-5,
8-8 or 12-15 IU of PMSG/hCG, 48 h apart, at different age intervals (from 30 to >
120 days old). The best superovulation rate was obtained with 8-8 IU PMSG/hCG.
Ovulation started about 10 h post-hCG and was completed during the next 4-5 h,
and was achieved irrespectively from the oestrus cycle stage. The number of
oocytes was influenced by the age of the females. The youngest females had only a
superovulatory response. Females older than 61 days showed both ovulatory and
superovulatory responses, although 91-120-day-old females had a high ovulatory
response. Most of the oocytes (96.5%) recovered were morphologically normal. The
genus Calomys constitutes a reproductive model completely different from
conventional laboratory rodents.
PMID- 10778787
TI - Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)
assay for the mouse leptin receptor (Lepr(db)) mutation.
AB - A PCR-RFLP assay for genotyping at the mouse leptin receptor (Lepr(db)) mutation
site was developed using modified primers. The first modified primer creates an
AccI restriction site in the mutant Lepr(db) allele to distinguish between the
Lepr(db) and Lepr+ alleles whereas the second modified primer creates another
AccI site in both alleles to serve as a control for restriction enzyme digestion.
The assay is robust and works efficiently on unpurified lysates of mouse tissues
and can be applied at any age of the animal. The assay may be used as a
diagnostic tool for maintenance of stocks, introgression or other types of
crosses involving the Lepr(db) mutation.
PMID- 10778788
TI - DNA detection in hair of transgenic mice--a simple technique minimizing the
distress on the animals.
AB - The breeding of transgenic animals requires that each individual offspring be
analysed for integration of transgenic deoxyribonucleic acid (DNA), unless
exclusively homozygous animals are mated. The standard protocol for
identification of transgenic animals (Hogan et al. 1994) is based on tissue
samples and preparation of chromosomal DNA including proteinase K digestion and
phenol/chloroform extraction. The procedure described here represents a much
simpler and faster method to screen offspring for the transgene DNA. It is based
on the use of hair bulbs as sample material, which can be directly used for
polymerase chain reaction (PCR) after alkaline lysis. This protocol allows large
numbers of animals to be easily screened in a minimum amount of time. A unique
advantage though, is the reduction of the distress caused to the animals. With
respect to the 3Rs (Replacement, Reduction, Refinement), and because of technical
advantages this method may replace ear or tail clipping.
PMID- 10778789
TI - Sarcocystis muris--a rare case in laboratory mice.
AB - In a lifespan transgeneration study under standard laboratory conditions using a
total of 4682 CBA/J mice, unusual intramuscular inclusions were found in the
diaphragm, heart and skeletal muscle of one mouse using light microscopy. Located
within the myocytes, they caused no visible tissue reaction. Cross-sections of
these spherical and cystic lesions showed numerous banana-shaped structures,
identified as permanent parasitic bradyzoites, which permitted these infections
to be diagnosed microscopically as sarcocystosis.
PMID- 10778791
TI - Progress in development of immunization registries--United States, 1999.
AB - Community-based and state-based immunization registries are confidential,
population-based, computerized information systems that contain data about
children's vaccinations and represent an important tool to increase and sustain
high vaccination coverage. Immunization registries consolidate vaccination
records for children from multiple providers, provide a vaccination needs
assessment for each child, generate reminder and recall vaccination notices,
produce an official vaccination record, and provide practice-specific and
community-based vaccination coverage assessments. One of the Healthy People 2010
national objectives is to increase to 95% the proportion of children aged <6
years who are enrolled in a fully operational population-based immunization
registry. To assess the status of immunization registry development, CDC analyzed
data from the 1999 Immunization Registry Annual Report (IRAR) of 64 jurisdictions
(grantees) that receive federal immunization funds under section 317d of the
Public Health Service Act. Findings from this analysis indicate that substantial
progress has been made in the United States in developing and implementing
community-based and state-based immunization registries.
PMID- 10778790
TI - Histological characteristics of the intestinal mucosa of the rat during the first
year of life.
AB - In spite of the widespread use of rats in gastrointestinal research, there is a
lack of information on the qualitative and quantitative histological
characteristics. Therefore, a study was performed in 69 male Wistar rats with
ages ranging from one day to one year old. The features studied included: height
and number of villi in the duodenum, jejunum and ileum, and depth and number of
crypts in the duodenum, jejunum, ileum, colon and rectum. Morphometric
observations were expressed in a mathematical logarithmic curve that showed a
normal, pattern of intestinal growth for each intestinal level. The number of
villi in the small intestine decreased from 1 to 35 days of age, whereas the
other intestinal parameters all increased during the same period. After 35 days
the rates of increase or decrease were lower. The quantification of these
intestinal changes provides a new complementary pattern as a reference for
research as indicators of normality or malfunction in the rat intestine.
PMID- 10778792
TI - Palmar pallor as an indicator for anthelminthic treatment among ill children aged
2-4 years--Western Kenya, 1998.
AB - Infections with the soil-transmitted intestinal helminths (i.e., Ascaris
lumbricoides, Trichuris trichiura, and hookworm), estimated to affect
approximately 1 billion persons, are among the most common and widespread human
infections. Among children aged <5 years, intestinal helminth infections cause
malnutrition and anemia, two important causes of mortality. Anthelminthic
treatment (deworming) improves nutritional status of school-aged children. The
World Health Organization and the United Nations Children's Fund (UNICEF) have
developed guidelines that include interventions for anemia and malnutrition in
the integrated management of childhood illness (IMCI) for children aged <5 years
seen at first-level health-care facilities in developing countries. Under the
IMCI guidelines, in geographic areas where hookworm or Trichuris infections are
endemic, children aged 2-4 years with palmar pallor are treated with an
anthelminthic drug. This report summarizes an investigation of the use of palmar
pallor as an indication for anthelminthic treatment among ill children aged 2-4
years seen at first-level health-care facilities in rural western Kenya; the
investigation found that palmar pallor was associated with anemia but not with
intestinal helminth infection.
PMID- 10778793
TI - Community indicators of health-related quality of life--United States, 1993-1997.
AB - It is known that persons' longevity is affected by the environmental and
population characteristics of their community. Studies that identify community
level characteristics associated with the health-related quality of life (HRQOL)
of residents could help guide local health planning. Data from the Behavioral
Risk Factor Surveillance System (BRFSS) for 1993-1997 indicate that HRQOL differs
among U.S. counties according to county population size. In addition,
socioeconomic and health status indicators, such as poverty, noncompletion of
high school, unemployment, number of persons with severe work disabilities,
mortality, and births to adolescents, also might affect county-level HRQOL
differences. This report examines initial findings on the relation between
selected community health status indicators (CHSIs) and the mean number of days
that persons aged > or =18 years reported ill health (i.e., unhealthy days), a
surveillance measure of population HRQOL. The findings suggest that CHSIs may be
useful in the public health planning process.
PMID- 10778794
TI - Influence of ankle support on joint range of motion before and after exercise: a
meta-analysis.
AB - STUDY DESIGN: Meta-analysis. OBJECTIVE: To evaluate the effects of different
types of ankle support on ankle and foot joint range of motion before and after
activity using meta-analysis procedures. BACKGROUND: The effects of ankle support
on joint range of motion before and after exercise has been extensively studied,
but the results among studies are not consistent. Obtaining knowledge from
synthesizing the available literature with a meta-analysis can provide a greater
understanding of these effects. METHODS AND MEASURES: A total of 253 cases from
19 studies were examined and included in this analysis. The treatment variables
were ankle support with 3 levels (tape, lace-up, and semirigid) and time with 2
levels (before exercise and after exercise). Standardized effect sizes were
computed for inversion, eversion, dorsiflexion, and plantar flexion range of
motion to measure the difference between control and treatment groups at each
point in time. Effect sizes were analyzed using a mixed-model factorial analysis
of variance. RESULTS: Before exercise, the semirigid condition (-2.97 +/- 0.63)
demonstrated greater restriction compared with the tape (-2.33 +/- 0.38) and lace
up conditions (-2.18 +/- 0.86) for inversion range of motion. After exercise, the
semirigid condition (-3.85 +/- 0.64) restricted inversion range of motion more
than the tape (-1.07 +/- 0.20) and lace-up (-1.56 +/- 0.29) conditions. No
differences were found between the mean effect sizes for the tape and lace-up
conditions before and after exercise. With respect to eversion range of motion,
the semirigid support (-2.69 +/- 0.43) provided greater restraint compared with
the tape (-1.00 +/- 0.21) and lace-up (-1.40 +/- 0.47) conditions. The lace-up
condition also displayed greater support compared with tape alone. For
dorsiflexion range of motion, greatest overall support was provided by the tape
condition (-0.94 +/- 0.06) compared with the lace-up condition (-0.51 +/- 0.06).
CONCLUSIONS: The greatest restriction of motion in the frontal plane was offered
by the semirigid support condition, whereas taping offered the most support for
limiting dorsiflexion range of motion. The results of this study may help
clinicians make rational decisions concerning the selection of ankle appliances
for preventing acute or chronic reinjury.
PMID- 10778795
TI - Influence of orthopaedic clinical specialist certification on clinical outcomes.
AB - STUDY DESIGN: Effect of clinical specialization was studied in a retrospective
analysis of a commercial outcomes database. OBJECTIVE: To assess effectiveness of
care as measured by changes in health status and efficiency as measured by
visits, duration of treatment episode, and net revenue between patients treated
by clinicians with and without orthopaedic clinical specialist certification
(OCS). BACKGROUND: Clinical specialization is becoming common in physical
therapy, but there are no studies to support improved efficiency or effectiveness
with advanced practitioner competencies. METHODS AND MEASURES: A total of 258
adults treated in practices participating in the Focus on Therapeutic Outcomes
process during 1996 comprised the data set. Seven physical therapists with OCS
treated 129 patients (clinical specialist group). These patients were matched to
129 patients not treated by physical therapists with OCS (comparison group)
randomly chosen from the aggregate data set. All patients completed a
standardized health status questionnaire at initial evaluation and discharge.
Standardized response means (SRMs) were calculated to measure change during
treatment. RESULTS: Therapists with OCS were more efficient than therapists
without OCS, using fewer visits (9.1 +/- 6.7 vs 11.2 +/- 7.4) for less estimated
cost ($949 +/- $736 vs $1238 +/- $1227) during the same treatment duration (35.9
+/- 48.3 vs 35.4 +/- 25.6 days) and performed fewer treatment procedures.
Overall, there was no difference in effectiveness as measured by change in health
status, that is, unit of functional improvement per episode (0.89 +/- 1.0 SRM for
clinical specialists compared with 0.88 +/- 1.0 SRM for comparison group). The
OCS group had better value (unit of functional improvement per estimated dollar)
and utilization (unit of functional improvement per visit) for the constructs of
physical functioning (value: 1.31 +/- 2.7 vs 0.78 +/- 1.8; utilization: 1.25 +/-
2.2 vs 0.76 +/- 1.6) and role physical (value: 1.26 +/- 2.9 vs 0.44 +/- 3.5;
utilization: 1.11 +/- 1.9 vs 0.51 +/- 2.3) (SRMs for OCS group vs comparison
group, respectively). CONCLUSIONS: Our data support the conclusion that physical
therapists with OCS are more efficient compared with clinicians without OCS.
Study limitations in design, small sample size, and low number of clinicians are
discussed.
PMID- 10778796
TI - Proposed practice guidelines for nonoperative anterior cruciate ligament
rehabilitation of physically active individuals.
AB - Nonoperative management of anterior cruciate ligament (ACL) rupture has not been
a successful option for those who participate in high-level physical activity.
However, there are instances when patients may want to attempt to return to
physically demanding activities with nonoperative rehabilitation for an ACL
injury. The purpose of this commentary is to describe guidelines for nonoperative
management of physically active individuals with ACL injuries who wish to return
to preinjury levels of physical activity. The guidelines are based on the results
of 2 clinical studies that improved the overall success of nonoperative
management of physically active individuals with ACL ruptures. A decision-making
process for selecting appropriate candidates for nonoperative management
(rehabilitation candidates) is described. Individuals are classified as
rehabilitation candidates if they have no concomitant ligament or mensical damage
associated with the ACL injury, have a unilateral ACL injury, and meet all 4 of
the following criteria: (1) timed hop test score of 80% or more of the uninjured
limb, (2) Knee Outcome Survey Activities of Daily Living Scale score of 80% or
more, (3) global rating of knee function of 60% or more, and (4) no more than 1
episode of giving way since the incident injury to the time of testing.
Individuals meeting the criteria of a rehabilitation candidate undergo an
intensive rehabilitation program before returning to high-level activity. The
rehabilitation program consisting of lower extremity muscle strength training,
cardiovascular endurance training, agility and sport-specific skill training, and
a training program using balance perturbations is described.
PMID- 10778797
TI - Shoulder muscle activation during aquatic and dry land exercises in nonimpaired
subjects.
AB - STUDY DESIGN: Randomized, single blind experimental design using electromyography
to measure shoulder muscle activation in nonimpaired subjects. OBJECTIVES: To
compare the muscle activation of rotator cuff and shoulder synergists during
rehabilitation exercises performed in water or on dry land. BACKGROUND: Early
motion is critical to restoration of normal shoulder function. Aquatic therapy
has been promoted as a method for increasing range of motion while minimizing
stress on the shoulder. METHODS AND MEASURES: The integrated electromyography
amplitude of 6 muscles of the shoulder girdle was examined on the nondominant
shoulders of 6 subjects (supraspinatus, infraspinatus, and subscapularis,
anterior, middle, and posterior deltoids). Each subject performed elevation (0
degree to 90 degrees) in the scapular plane with neutral rotation on land and in
water at 3 different speeds of elevation (30 degrees/s, 45 degrees/s, and 90
degrees/s). The mean percentage of the maximal voluntary contraction was
determined for each of the 3 test speeds on land and in water. Comparisons
between water and dry land were made with a repeated measures analysis of
variance. RESULTS: For all 6 muscles tested, muscle activation during the 30
degrees/s test speed and all muscles tested at the 45 degrees/s test speed was
significantly less when performed in water versus when performed on land. For
example, electromyography activation of the supraspinatus muscle was 16.68% of a
maximal voluntary contraction when elevation at was performed at 30 degrees/s on
dry land versus 3.93% when performed in water. CONCLUSION: These data suggest
that shoulder elevation in the water at slower speeds resulted in a significantly
lower activation of the rotator cuff and synergistic muscles. This decreased
muscle activation during aquatic physical therapy allows for earlier active
motion in the postoperative period without compromising patient safety.
PMID- 10778798
TI - Effects of isometric quadriceps activation on the Q-angle in women before and
after quadriceps exercise.
AB - STUDY DESIGN: Single-group test-retest design with correlation analysis.
OBJECTIVES: (1) To confirm that the Q-angle decreases with isometric quadriceps
activation (IQA), (2) to determine if the decrease in the Q-angle with IQA is
related to the magnitude of the Q-angle at rest, and (3) to determine if a
vigorous bout of exercise affects the change in the Q-angle with IQA. BACKGROUND:
The Q-angle represents an estimate of the resultant force of the quadriceps on
the patella and is a predictor of lateral movement of the patella under dynamic
conditions. METHODS AND MEASURES: Q-angles were assessed in 22 nonimpaired women
(mean +/- SD age, 22.3 +/- 4.9 years) while standing relaxed and during IQA.
Subjects then rode a cycle ergometer until a preset number of repetitions per
minute was unable to be maintained. Q-angles were again assessed while subjects
were relaxed and during IQA. RESULTS: There was a significant decrease (mean +/-
SD, 5.7 +/- 4.2 degrees) in the Q-angle with IQA compared with relaxed standing.
There was a significant relationship (r=0.72) between the Q-angle at rest and the
change with IQA. The cycle ergometer exercise resulted in a small (0.5 degrees)
but significantly greater decrease in the Q-angle with IQA compared with relaxed
standing. CONCLUSIONS: The Q-angle decreases with IQA, and the magnitude of this
decrease is dependent on the magnitude of the Q-angle at rest. Our findings
support the view that an excessive Q-angle may predispose women to greater
lateral displacement of the patella during vigorous activities and sports in
which the quadriceps muscle is stressed.
PMID- 10778799
TI - Plantar fasciitis.
PMID- 10778800
TI - Relationship between the pixel value in digital subtraction angiography and
iodine concentration: study in high iodine concentration with original phantom.
AB - Quantitative digital subtraction angiography (DSA) image analysis based on
densitometry is widely accepted and used. For the densitometoric DSA image
analysis, it is required that there is a linear relationships between the pixel
values on DSA images (DSA values) and contrast medium iodine concentration or the
thickness of the vessels or the chambers filled with contrast material. We
studied on relationship between the DSA value and iodine concentration especially
in high iodine concentration. As for the relationship between DSA values and
iodine concentration on the DSA images at low concentration, DSA phantom had a
good linear relationship. However, the relationship at the high iodine
concentration, DSA phantom sometimes lost this linear relationship. Our results
suggested that it was necessary to identify relationship between DSA values and
iodine concentration in each DSA system, especially in high iodine concentration
setting, for densitometoric DSA image analysis.
PMID- 10778801
TI - HLA-DR expression of synovium and correlation with clinical features of patients
with rheumatoid arthritis.
AB - To investigate whether the expression of human leukocyte antigen-DR (HLA-DR) in
synovial tissues obtained at synovectomy contributes to the clinical features of
patients with rheumatoid arthritis (RA), immunohistochemical analysis was
performed to determine the intensity and pattern of HLA-DR expression in synovial
tissue from 96 patients with RA. The clinical features before and 1 year after
the synovectomy were investigated. At the time of the surgery, duration of
morning stiffness was associated with the degree of HLA-DR expression in synovial
lining layer, and this synovial lining expression of HLA-DR was more frequently
observed in elbow and wrist joints than in knee joint. In patients who underwent
knee synovectomy, erythrocyte sedimentation rate and C-reactive protein level one
year after the surgery were significantly higher in the patients with intense
expression of HLA-DR in the synovial lining. Our findings showed that the
expression of HLA-DR in the synovial lining contributes to several clinical
features, and the expression in large joint such as knee may related with disease
course of patients with RA.
PMID- 10778802
TI - The prevalence of serum GB virus C/hepatitis G virus RNA and anti-E2 in Japanese
children without a history of blood transfusion.
AB - The prevalence of serum GB virus C (GBV-C)/Hepatitis G virus (HGV) RNA and anti
E2 was investigated in Japanese children younger than 16 years of age without a
history of blood transfusion and the family members of serum GBV-C/HGV RNA
positive children. The prevalences of serum GBV-C/HGV RNA and anti-E2 were 0.5%
(5/1000) and 0% (0/330), respectively. Viral RNA was also detected in the mothers
of all five GBV-C/HGV RNA-positive children and in two of their siblings.
Sequence determinations indicated the likelihood of mother-to-infant transmission
in all cases. The presence of the virus persisted for at least 10-18 months in
all 5 children, without any appearance of anti-E2.
PMID- 10778803
TI - A questionnaire survey on current surgical procedures for endometrial cancer in
Japan.
AB - The current standards for surgical procedures and lymph node dissection of
endometrial cancer in Japan were investigated using a questionnaire survey. The
estimated clinical stages used in the questionnaire were predicted from
preoperative diagnostic imaging, histopathology of endometrial biopsies and
intraoperative findings using a new classification, Federation Internationale de
Gynecologie et d'Obstetrique (FIGO) in 1988. Questionnaires were mailed to 235
institutions, and 212 institutions (90.2%) responded. As a standard surgery for
endometrial cancer, institutions performed simple total hysterectomy or
semiradical hysterectomy and bilateral adnexectomy, which accounted for 86% of
all respondents. For stage I carcinoma, simple (44%) or semi-radical (47%)
hysterectomy was carried out in 91% of institutions, while radical hysterectomy
was selected in 84% of institutions when stage II carcinoma was diagnosed
clinically. The consensus of this survey was that dissection of both the para
aortic and pelvic lymph nodes can be omitted in G1 cases showing lesions confined
to the endometrium, and that pelvic lymph nodes should be dissected, but para
aortic lymph node dissection could be omitted in G1 or G2 cases demonstrating
myometrial invasion of 1/2 or less. Moreover, findings from this survey suggest
that biopsy or dissection of the para-aortic lymph nodes was required in G3
cases, or in those patients diagnosed with myometrial invasion more than 1/2.
PMID- 10778804
TI - The absence of impairment of cliff avoidance reaction induced by subchronic
methamphetamine treatment in inbred strains of mice.
AB - Cliff avoidance reaction (CAR), an index of behavioral teratology in rodents, can
be impaired by motor, arousal, or cognitive dysfunction. We formerly reported
subchronic administration of methamphetamine (MAP) induced the CAR impairment,
which might reflect MAP-induced cognitive dysfunction, in three strains of rats.
In this study, the effects of subchronic MAP treatment on the behavioral
sensitization in stereotypy (stereotypy sensitization) and CAR were examined in
two inbred strains of male mice; C57BL/6J(C57) and DBA/2J(DBA). The animals
received 4 mg/kg/day MAP intraperitoneally for 28 days. There were apparent
strain differences in the development of stereotypy sensitization induced by
chronic MAP; DBA mice developed stereotypy sensitization quickly, but C57 did
not. Unlike rats, neither strains of mice showed the CAR impairment. These
results suggest that chronic MAP (4 mg/kg) administration did not introduce any
cognitive dysfunction measured by CAR in the two inbred mice, DBA and C57. The
discrepancy between rats and mice is still unclear. It might relate to the
species-selective effect of MAP on the CAR impairment. Further studies should to
be required.
PMID- 10778805
TI - PCR and RFLP analysis for identification and typing of Helicobacter pylori
strains isolated from gastric biopsy specimens.
AB - Helicobacter pylori (H. pylori) infection is the most common gastrointestinal
tract infection which plays an important role in the ethiopathogenesis of peptic
ulcer and gastritis. In recent years, molecular biological methods have been
presented for detection of H. pylori in addition to histopathological and
microbiological methods. Among these methods, polymerase chain reaction (PCR) and
following restriction fragment length polymorphism analyses (RFLP) are highly
sensitive methods for diagnosis and follow up of patients. In this present study
our aim was to amplify H. pylori urease A and B genes by PCR and perform RFLP
analysis. Gastric biopsy specimens from 17 female and 18 male patients were
included in the study. Amplified PCR products were subjected to RFLP analysis and
typing of the bacteria in pre and posttreatment specimens were performed. H.
pylori urease A and B gene amplification was observed in 32 pretreatment samples
and in 8 of 21 posttreatment specimens. As a result, PCR is a sensitive method to
determine the H. pylori infection. RFLP, which is another effective method in
order to demonstrate the reinfection of H. pylori.
PMID- 10778806
TI - Ceramide-induced cell death in cultured rat retinal pigment epithelial cells.
AB - We investigated whether retinal pigment epithelial (RPE) responds to ceramide, a
known second messenger of apoptosis. RPE cells were isolated by 6-8 day old Long
Evans rat eye. We used MTS assay for viability test, and used Hoechst 33552 and
propidium iodide for apoptotic cell staining. In cultured rat RPE cells, the
addition of membrane-permeable ceramide induced apoptosis-like cell death
rapidly. RPE cell death was dependent on C2-ceramide concentration. The effective
dose (ED50) of C2-ceramide was 23.64 microM. Ceramide-induced RPE cell death was
inhibited by zVAD-fmk, a CPP32-like protease inhibitor. Our findings indicated
that ceramide in RPE cell death functions upstream of CPP32-like proteases.
PMID- 10778807
TI - Telomerase activity in normal ovaries and premature ovarian failure.
AB - The average age for the onset of menopause in humans is about 51 years. On the
other hand, premature ovarian failure (POF) is generally defined as the onset of
menopause before the age of 40 years. Telomeres have been extensively examined as
a mitotic clock. Telomeric DNA is elongated by telomerase. We analyzed the
telomerase activity of 20 patients with normal ovaries and 5 patients with POF.
Telomerase activity was present in the normal ovaries, however it decreased with
age. Eight normal ovaries under 38 years of age showed significantly higher
telomerase activity among the women with a regular menstrual cycle. Two POF
patients showed high telomerase activity and 3 showed low telomerase activity.
Our findings indicate that telomerase is present in the normal human ovary and
that telomerase activity decreases with age. Patients with follicle dysfunction
showed high telomerase activity and those with follicle depletion showed very low
telomerase activity. Based on these results, we speculated that the decline of
telomerase activity in the ovary is related to primordial follicle depletion with
age and telomerase activity can be used as a marker of the ovarian functional
age.
PMID- 10778808
TI - Better health care decisions: fulfilling the promise of health services research.
PMID- 10778809
TI - Uninsured and unstably insured: the importance of continuous insurance coverage.
AB - OBJECTIVE: To examine the importance of continuous health insurance for access to
care by comparing the access and cost experiences of insured adults with a recent
time uninsured to the experiences of currently uninsured adults and experiences
of adults with no time uninsured within a reference time period (continuously
insured). DATA SOURCES: Adults ages 18-64. Data draw from three different survey
databases: the Robert Wood Johnson Foundation 1996-1997 Community Tracking
Survey, the Kaiser/Commonwealth 1997 National Survey of Health Insurance, and the
1995-1997 Kaiser/Commonwealth State Low Income Surveys. STUDY DESIGN: The study
groups individuals into three insurance categories based on respondents' reports
of insurance coverage within a reference time period: continuously insured;
insured when surveyed but with recent time uninsured; and currently uninsured. In
the two Kaiser/Commonwealth surveys the recently uninsured group included any
insured respondent with a time uninsured in the past two years. In the Community
Tracking Survey, the recently uninsured group included any insured respondent
with a time uninsured in the past year. Measures of access include foregoing
health care when needed, usual source of care, use of health care services,
difficulties paying for medical care, and satisfaction with care. DATA
COLLECTION: All three surveys were conducted primarily by telephone. The
Community Tracking Survey drew from 60 community sites, with an additional random
national sample. The Kaiser/Commonwealth National Survey was a random national
sample; the Kaiser/Commonwealth State Low Income Surveys included adults ages 18
64 with incomes at or below 250 percent of poverty in seven states: Minnesota,
Oregon, Tennessee, Florida, Texas, New York, and California. PRINCIPAL FINDINGS:
Compared to the continuously insured, those insured but with a recent time
uninsured were at high risk of going without needed care and of having problems
paying medical bills. This group was two to three times as likely as those with
continuous coverage to report access problems. Rates of access and cost problems
reported by insured adults with a recent time uninsured neared levels reported by
those who were uninsured at the time of the survey. These two groups also rated
care received more negatively than did adults with continuous insurance coverage.
In general, the access gap between persons insured and uninsured widened as a
result of distinguishing insured adults with a recent time uninsured from insured
adults with no time uninsured. CONCLUSION: Studies that focus on current
insurance status alone will underestimate the extent to which having a time
uninsured during the year contributes to access difficulties and undermines
quality of care, and will underestimate the proportion of the population at risk
because they are uninsured. Policy reforms are needed to maintain continuous
insurance coverage and avoid spells uninsured. Currently uninsured and unstably
insured adults are both at high risk.
PMID- 10778810
TI - Promises unfulfilled: implementation of expanded coverage for the elderly poor.
AB - OBJECTIVE: To examine implementation of the Qualified Medicare Beneficiary (QMB)
and Specified Low-Income Medicare Beneficiary (SLMB) programs, enacted in 1988.
The article summarizes the origin of the QMB and SLMB programs, describes what we
have learned about QMB and SLMB enrollment in state Medicaid programs and,
despite some encouraging news on the federal front, identifies policy issues that
remain in assuring access to health care for the low-income elderly. SOURCE:
Based in part on research that assessed state variations in Medicaid QMB and SLMB
enrollment of low-income Medicare beneficiaries and identified best practices
among states in administration of the QMB and SLMB programs. STUDY DESIGN:
Telephone interviews were conducted with officials in ten states to elicit
qualitative information about how state Medicaid programs have implemented
federal protections for low-income Medicare beneficiaries. PRINCIPAL FINDINGS:
The QMB and SLMB programs fail to reach a sizable proportion of potentially
eligible individuals in most states. Fragmentation of Medicare and Medicaid
benefits, complex Medicaid eligibility and income verification processes, and
rigid federal and state administrative and data systems, impede efforts to
achieve promised protection for low-income elderly persons. CONCLUSIONS: For low
income Medicare beneficiaries, obtaining financial protection against their high
out-of-pocket health care costs remains an important issue. The complexities
associated with aligning Medicare and Medicaid to deliver health benefits to low
income older persons makes improved coordination across federal and state
agencies uncertain.
PMID- 10778811
TI - Does type of health insurance affect health care use and assessments of care
among the privately insured?
AB - OBJECTIVE: To inform the debate about managed care by examining how different
types of private insurance-indemnity insurance, PPOs, open model HMOs, and closed
model HMOs-affect the use of health services and consumer assessments of care.
DATA SOURCES/DATA COLLECTION: The 1996-1997 Community Tracking Study Household
Survey, a nationally representative telephone survey of households, and the
Community Tracking Study Insurance Followback Survey, a supplement to the
Household Survey, which asks insurance organizations to match household
respondents to specific insurance products. The analysis sample includes 27,257
nonelderly individuals covered by private insurance. STUDY DESIGN: Based on
insurer reports, individuals are grouped into one of the four insurance product
types. Measures of service use include ambulatory visits, preventive care use,
hospital use, surgeries, specialist use, and whether there is a usual source of
care. Consumer assessments of care include unmet or delayed care needs,
satisfaction with health care, ratings of the last physician visit, and trust in
physicians. Estimates are adjusted to control for differences in individual
characteristics and location. PRINCIPAL FINDINGS: As one moves from indemnity
insurance to PPOs to open model HMOs to closed model HMOs, use of primary care
increases modestly but use of specialists is reduced. Few differences are
observed in other areas of service use, such as preventive care, hospital use,
and surgeries. The likelihood of having unmet or delayed care does not vary by
insurance type, but the reasons that underlie such access problems do vary:
enrollees in more managed products are less likely to cite financial barriers to
care but are more likely to perceive problems in provider access, convenience,
and organizational factors. Consumer assessments of care-including satisfaction
with care, ratings of the last physician visit, and trust in physicians-are
generally lower under more managed products, particularly closed model HMOs.
CONCLUSIONS: The type of insurance that people have-not just whether it is
managed care but the type of managed care-affects their use of services and their
assessments of the care they receive. Consumers and policymakers should be
reminded that managed care encompasses a variety of types of insurance products
that have different effects and may require different policy responses.
PMID- 10778812
TI - The effect of marginal tax rate on the probability of employment-based insurance
by risk group.
AB - RESEARCH OBJECTIVE: To evaluate the effect of the tax subsidy on participation in
employment-based health insurance for high- and low-risk individuals. The total
exclusion of employer-paid health insurance premiums from taxable income has
frequently been seen as contributing to excess insurance and hence welfare loss.
However, less attention has been paid to quantifying the extent to which the tax
subsidy mitigates the deleterious effects of adverse selection on the health
insurance market. Adverse selection reduces pooling in an insurance market, so
that high-risk individuals are either unable to obtain coverage or are forced to
pay premiums that are unaffordable to all but the wealthiest. If there is an
external benefit to society of an individual's purchase of medical care, then the
presence of adverse selection may reduce the purchase of health care below the
socially optimal level. Therefore, a mechanism for enhancing access to insurance
and ultimately to medical care for high-risk individuals may be socially
desirable. STUDY DESIGN: Data from the March 1996-March 1998 Current Population
Survey (CPS). For each observation in the sample, state and federal income tax
liability is calculated using code based on the ACIR Significant Features of
Fiscal Federalism. The probability of having employment-based coverage in either
one's own name or as a dependent is evaluated as a function of demographic
variables such as age, education, marital status and family size, family income,
type of employment, employer size, occupation, location, marginal tax rate, risk
group (determined by self-assessed health status), and an interaction between
risk group and tax rate. CPS data do not identify individuals who have declined
offered coverage. Under alternative models of employer group decision making, the
tax subsidy will have an important influence on the employer's decision to offer
coverage. If offered, high-risk individuals accept coverage, while some low-risk
individuals may decline coverage. PRINCIPAL FINDINGS: For all individuals, the
probability of having coverage is an increasing function of the marginal tax
rate. Those classified as high-risk because their own or a family member's self
assessed health status is fair or poor are less likely to have coverage than
those considered low-risk. The effect of the tax subsidy on insurance coverage is
greater for high-risk individuals than for individuals classified as low-risk.
CONCLUSIONS: These preliminary results indicate that high-risk individuals
benefit from the tax subsidy by increased access to employment-based coverage.
Therefore, welfare loss from excess levels of health insurance may be mitigated
by welfare gain through expanded access to health insurance and hence to health
care for high-risk individuals. IMPLICATIONS FOR POLICY, DELIVERY, OR PRACTICE:
Elimination or reduction of the tax exclusion of health insurance premiums may
have the unintended consequences of disproportionately reducing the probability
of obtaining coverage in the employment-based market for high-risk individuals.
PMID- 10778814
TI - Mental health parity legislation: much ado about nothing?
AB - OBJECTIVE: To determine whether state-level parity legislation has led to an
increase in utilization of mental health services. DATA SOURCES: Healthcare For
Communities (HCC), a multi-site nationally representative study sponsored by the
Robert Wood Johnson Foundation that tracks health care system changes for mental
health and substance abuse treatment. Information on state-level parity
legislation was provided by state offices of the National Alliance for the
Mentally Ill (NAMI); local and state market data come from the Area Resource
File; information on other health mandates from Blue Cross/Blue Shield. STUDY
DESIGN: Two-stage regressions are used to estimate the effect of state parity
legislation on use of any mental health services, use of specialty mental health
services, and number of specialty visits in the past year. In the first stage, we
predicted the probability that a state decides to pass parity legislation as a
function of state health care market indicators and previous legislative
activity. The fitted probability is used in the second stage to determine the
effect of this legislation on access and utilization. PRINCIPAL FINDINGS: State
parity legislation is not associated with a significant increase in any of our
measures of mental health services utilization. These results are robust to
various specifications of the models. CONCLUSIONS: Those states that are able to
pass parity legislation do not experience significant increases in the
utilization of mental health services. This may be due in part to a loss of
coverage for those people most at risk for mental health disorders. The results
could be very different, however, if strong federal legislation were passed.
PMID- 10778813
TI - Health insurance may be improving--but not for individuals with mental illness.
AB - OBJECTIVE: To explore the question of how insurance coverage has changed among
individuals with mental problems compared to the general population in the last
two years. DATA SOURCES: HealthCare for Communities, a national survey to track
health system changes. PRINCIPAL FINDINGS: The percentage of uninsured persons in
the general population has not changed very much, and more respondents believe
that health insurance coverage has improved rather than deteriorated over the
years 1996 to 1998. However, among individuals with probable mental health
disorders, more have lost insurance in those two years than have gained it and
more report decreases in health benefits. Individuals with worse mental health
consistently report a deterioration of access to care compared to individuals
with better mental health. CONCLUSIONS: Substantial activity has taken place in
state and federal legislation to increase the mental health benefits offered by
health insurance. Although this activity could have improved health insurance
especially for individuals with mental illness, such persons continue to fare
significantly worse than the general population.
PMID- 10778815
TI - Utilization of specialty mental health care among persons with severe mental
illness: the roles of demographics, need, insurance, and risk.
AB - OBJECTIVE: To examine the sociodemographic, need, risk, and insurance
characteristics of persons with severe mental illness and the importance of these
characteristics for predicting specialty mental health utilization among this
group. DATA SOURCE: The Healthcare for Communities survey, a national study that
tracks alcohol, drug, and mental health services utilization. Data come from a
telephone survey of adults from 60 communities across the United States, and from
a supplemental geographically dispersed sample. STUDY DESIGN: Respondents were
categorized as having a severe mental disorder, other mental disorder, or no
measured mental disorder. Differences among groups in sociodemographics (gender,
marital status, race, education, and income), insurance coverage, need for mental
health care (symptoms and perceived need), and risk indicators (suicide ideation,
criminal involvement, and aggressive behavior) are examined. Measures of service
use for mental health care include emergency room, inpatient, and specialty
outpatient care. The importance of sociodemographics, need, insurance status, and
risk indicators for specialty mental health care utilization are examined through
logistic regression. PRINCIPAL FINDINGS: The severely mentally ill in this study
are disproportionately African American, unmarried, male, less educated, and have
lower family incomes than those with other disorders and those with no measured
mental disorders. In a 12-month period almost three-fifths of persons with severe
mental illness did not receive specialty mental health care. One in five persons
with severe mental illness are uninsured, and Medicare or Medicaid insures 37
percent. Persons covered by these public programs are over six times more likely
to have access to specialty care than the uninsured are. Involvement in the
criminal justice system also increases the probability that a person will receive
care by a factor of about four, independent of level of need. The average number
of outpatient visits for specialty care varies little across type of disorder,
and the median number of visits (ten) is equivalent for those with a severe
mental illness and those with other disorders. CONCLUSIONS: Persons with severe
mental illness have a high level of economic and social disadvantage. Barriers to
care, including lack of insurance, are substantial and many do not receive
specialty care. Public insurance programs are the major points of leverage for
improving access, and policy interventions should be targeted to these programs.
Problems of adequate care for the severely mentally ill may be exacerbated by the
managed care trend to reductions in intensity of treatment.
PMID- 10778816
TI - Community effects on access to behavioral health care.
AB - OBJECTIVE: To explore the effects of community-level factors on access to any
behavioral health care and specialty behavioral health care. DATA: Healthcare for
Communities household survey data, merged to supplemental data from the 1990
Census Area Resource File, 1995 U.S. Census Bureau Small Area Estimates, and 1994
HMO enrollment data. STUDY DESIGN: We use a random intercept model to estimate
the influences of community-level factors on access to any outpatient care, any
behavioral health care conditional on having received outpatient care, and any
specialty behavioral health care conditional on having received behavioral health
care. DATA COLLECTION: HCC data were collected in 1997 from about 10,000
households nationwide but clustered in 60 sites. PRINCIPAL FINDINGS: Individuals
in areas with greater HMO presence have better overall access to care, which in
turn affects access to behavioral health care; individuals in poorer communities
have less access to specialty care compared to individuals in wealthier
communities. CONCLUSIONS: Our findings of lower access to specialty care among
those in poor communities raises concerns about the appropriateness and quality
of the behavioral health care they are receiving. More generally, the findings
suggest the importance of considering the current status and expected evolution
of HMO penetration and the income level in a community when devising health care
policy.
PMID- 10778817
TI - Individual income, income inequality, health, and mortality: what are the
relationships?
AB - OBJECTIVE: To examine the pathways between income inequality, self-rated health,
and mortality in the United States. DATA SOURCE: The first National Health and
Nutrition Examination Survey and Epidemiologic Follow-up Study. DESIGN: This was
a longitudinal, multilevel study. DATA COLLECTION: Baseline data were collected
on county income inequality, individual income, age, sex, self-rated health,
level of depressive symptoms, and severity of biomedical morbidity from physical
examination. Follow-up data included self-rated health assessed in 1982 through
1984 and mortality through 1987. PRINCIPAL FINDINGS: After adjustment for age and
sex, income inequality had a modest independent effect on the level of depressive
symptoms, and on baseline and follow-up self-rated health, but no independent
effect on biomedical morbidity or subsequent mortality. Individual income had a
larger effect on severity of biomedical morbidity, level of depressive symptoms,
baseline and follow-up self-rated health, and mortality. CONCLUSION: Income
inequality appears to have a small effect on self-rated health but not mortality;
the effect is mediated in part by psychological, but not biomedical pathways.
Individual income has a much larger effect on all of the health pathways.
PMID- 10778818
TI - Do quality report cards play a role in HMOs' contracting practices? Evidence from
New York State.
AB - OBJECTIVE: To answer two related questions: (1) Do managed care organizations
(MCOs) in New York State (NYS) consider quality when they choose cardiac
surgeons? (2) Do they use information about risk-adjusted mortality rates (RAMR)
provided in the New York State Cardiac Surgery Reports? DATA SOURCES: (1)
Telephone interviews with and contracting data from the majority of MCOs licensed
in NYS; (2) RAMR, quality outlier designation, and procedure volume for all
cardiac surgeons, as reported in the Cardiac Surgery Reports. STUDY DESIGN:
Interview data were analyzed in conjunction with patterns revealed by contracting
data. Null hypotheses that MCOs' contracting choices were random with respect to
the information published in the Cardiac Surgery Reports were tested. PRINCIPAL
FINDINGS: Sixty percent of MCOs ranked the quality of surgeons as most important
in their contracting considerations. Although 64 percent of MCOs indicated some
knowledge of the NYS Cardiac Surgery Reports, only 20 percent indicated that the
reports were a major factor in their contracting decision. Analyses of actual
contracting patterns show that in aggregate, the hypothesis of random choice
could be rejected with respect to high-quality outlier status and high procedure
volume but not for RAMR or poor-quality outlier status. The panel composition of
the majority of MCOs (80.2 percent) was within two standard deviations of the
expected mean under the null hypothesis. CONCLUSIONS: Despite a professed
preference for high-quality surgeons, the use of publicly available quality
reports by MCOs is currently low, and contracting practices for the majority of
MCOs do not indicate a systematic selection either for or against surgeons based
on their reported mortality scores. This study suggests that policy initiatives
to increase the effective use of report cards should be encouraged.
PMID- 10778819
TI - Associations between primary care physician satisfaction and self-reported
aspects of utilization management.
AB - OBJECTIVE: To evaluate the association between physician-reported utilization
management (UM) techniques in capitated physician groups and physician
satisfaction with capitated care. STUDY SETTING: 1,138 primary care physicians
from 89 California capitated physician groups in 1995. STUDY DESIGN: Eighty
percent of physicians (N = 910) responded to a mail survey regarding the UM
policies in their groups and their satisfaction with the care they deliver.
Physician-reported UM strategies measured included group-mandated
preauthorization (number of referrals requiring preauthorization, referral denial
rate, and referral turnaround time), group-provided explicit practice guidelines,
and group-delivered educational programs regarding capitated care. We also
measured two key dimensions of satisfaction with capitated care (multi-item
scales): (1) satisfaction with capitated care autonomy and quality, and (2)
satisfaction with administrative burden for capitated patients. EXTRACTION
METHODS: We constructed two multivariate linear regression models to examine
associations between physician-reported UM strategies and physician satisfaction,
controlling for demographic and practice characteristics and adjusting for
clustering. PRINCIPAL FINDINGS: Physician-reported denial rate and turnaround
time were significantly negatively associated with capitated care satisfaction.
Physicians who reported that their groups provided more guidelines were more
satisfied on both dimensions, while physicians who reported that their groups
sponsored more educational programs were more satisfied with administrative
burden. The number of clinical decisions requiring preauthorization was not
significantly associated with either dimension of satisfaction. CONCLUSIONS:
Physicians who reported that their groups used UM methods that directly affected
their autonomy (high denial rates and long turnaround times) were less satisfied
with care for capitated patients. However, a preauthorization policy for
referrals or tests was not, in and of itself, associated with satisfaction.
Indirect control mechanisms such as guidelines and education were positively
associated with satisfaction.
PMID- 10778820
TI - Comparing consumer-directed and agency models for providing supportive services
at home.
AB - OBJECTIVE: To examine the service experiences and outcomes of low-income Medicaid
beneficiaries with disabilities under two different models for organizing home
based personal assistance services: agency-directed and consumer-directed. DATA
SOURCE: A survey of a random sample of 1,095 clients, age 18 and over, who
receive services in California's In-Home Supportive Services (IHSS) program
funded primarily by Medicaid. Other data were obtained from the California
Management and Payrolling System (CMIPS). STUDY DESIGN: The sample was stratified
by service model (agency-directed or consumer-directed), client age (over or
under age 65), and severity. Data were collected on client demographics,
condition/functional status, and supportive service experience. Outcome measures
were developed in three areas: safety, unmet need, and service satisfaction.
Factor analysis was used to reduce multiple outcome measures to nine dimensions.
Multiple regression analysis was used to assess the effect of service model on
each outcome dimension, taking into account the client-provider relationship,
client demographics, and case mix. DATA COLLECTION: Recipients of IHSS services
as of mid-1996 were interviewed by telephone. The survey was conducted in late
1996 and early 1997. PRINCIPAL FINDINGS: On various outcomes, recipients in the
consumer-directed model report more positive outcomes than those in the agency
model, or they report no difference. Statistically significant differences emerge
on recipient safety, unmet needs, and service satisfaction. A family member
present as a paid provider is also associated with more positive reported
outcomes within the consumer-directed model, but model differences persist even
when this is taken into account. Although both models have strengths and
weaknesses, from a recipient perspective the consumer-directed model is
associated with more positive outcomes. CONCLUSIONS: Although health
professionals have expressed concerns about the capacity of consumer direction to
assure quality, particularly with respect to safety, meeting unmet needs, and
technical quality, our findings suggest that the consumer-directed service model
is a viable alternative to the agency model. Because public programs are under
growing pressure to address the long-term care needs of low-income people of all
ages with disabilities, the Medicaid personal assistance benefit needs to be
reassessed in light of these findings. Consumer-directed models may offer a less
elaborate and possibly less costly option for organizing supportive services at
home. Study limitations may limit the generalizability of these findings. This
was a natural experiment, in which only some counties offered both service models
and counties assigned recipients to a service model. The use of a telephone
survey excluded important recipient subsets, notably people with severe cognitive
impairments. A more definitive study would include direct observations as well as
survey approaches.
PMID- 10778821
TI - The Community Tracking Study analyses of market change: introduction.
AB - OBJECTIVE: To introduce two articles and describe methods that are common to
them. DATA SOURCES/STUDY SETTING: Interviews conducted in person in 1996/1997
with leaders of organizations involved in the financing and delivery of
healthcare. STUDY DESIGN: As part of the Community Tracking Study, 12
metropolitan statistical areas (MSAs) were selected randomly from MSAs with
populations over 200,000. Researchers made baseline site visits to these
communities and conducted from 36 to 60 interviews, depending on the size of the
site. The communities were compared to identify common patterns of change and
differences across communities. DATA COLLECTION/EXTRACTION METHODS: Researchers
conducted interviews with a broad cross-section of leaders in each community.
Interview modules were designed to obtain multiple perspectives on a question.
PRINCIPAL FINDINGS AND CONCLUSIONS: Fundamental changes in the way care is
actually delivered is likely to lag behind the extensive changes in
organizational relationships that are taking place.
PMID- 10778822
TI - Health plan competition in local markets.
AB - OBJECTIVE: To examine the structure of local health insurance markets and the
strategies health plans were using to respond to competitive pressures in local
markets in 1996/1997. DATA SOURCES/STUDY SETTING: Community Tracking Study site
visits conducted between May 1996 and April 1997 in 12 U.S. markets selected to
be nationally representative. STUDY DESIGN: In each site, 36 to 60 interviews on
local health system change were conducted with healthcare industry informants
representing health plans, providers, and purchasers. DATA COLLECTION/EXTRACTION
METHOD: Relevant data for this article were abstracted from standardized
protocols administered to multiple respondents in each site. PRINCIPAL FINDINGS:
Although the competitive threat from national plans was pervasive, local plans in
most sites continued to retain strong, often dominant, positions in historically
concentrated markets. In all sites, in response to purchaser pressures for stable
premiums and provider choice, and the threat of entry and to plans were using
three strategies to increase market share and market power: (1)
consolidation/geographic expansion, (2) price competition, and (3) product
line/segment diversification that focused on broad networks and open-access
products. In most markets, in response to the demand for provider choice, the
trend was away from ownership and exclusive arrangements with providers.
CONCLUSIONS: Although local plans were moving to become full-service regional
players, there was uncertainty about the abilities of all plans to sustain growth
strategies at the expense of margins and organizational stability, and to
effectively manage care with broad networks.
PMID- 10778823
TI - Organizing and managing care in a changing health system.
AB - OBJECTIVE: To examine ways in which the management and organization of medical
care is changing in response to the shifting incentives created by managed care.
DATA SOURCES: Site visits conducted in 12 randomly selected communities in 1996/
1997. STUDY DESIGN: Approximately 35-60 interviews were conducted per site with
key informants in healthcare and community organizations; about half were with
providers. DATA COLLECTION: A standardized interview protocol was implemented
across all sites, enabling cross-site comparisons. Multiple respondents were
interviewed on each issue. PRINCIPAL FINDINGS: A great deal of experimentation
and apparent duplication exist in efforts to develop programs to influence
physician practice patterns. Responsibility for managing care is being contested
by health plans, medical groups and hospitals, as each seeks to accrue the
savings that can result from the more efficient delivery of care. To manage the
financial and clinical risk, providers are aggressively consolidating and
reorganizing. Most significant was the rapid formation of intermediary
organizations, such as independent practice arrangements (IPAs), physician
hospital organizations (PHOs), or management services organizations (MSOs), for
contracting with managed care organizations. CONCLUSIONS: Managed care appears to
have only a modest effect on how healthcare organizations deliver medical care,
despite the profound effect that managed care has on how providers are organized.
Rather than improving the efficiency of healthcare organizations, provider
efforts to build large systems and become indispensable to health plans are
exacerbating problems of excess capacity. It is not clear if new organizational
arrangements will help providers manage the changing incentives they face, or if
their intent is to blunt the effects of the incentives by forming larger
organizations to improve their bargaining power and resist change.
PMID- 10778824
TI - Simulating the impact of medical savings accounts on small business.
AB - OBJECTIVE: To simulate whether allowing small businesses to offer employer-funded
medical savings accounts (MSAs) would change the amount or type of insurance
coverage. STUDY SETTING: Economic policy evaluation using a national probability
sample of nonelderly non-institutionalized Americans from the 1993 Current
Population Survey (CPS). STUDY DESIGN: We used a behavioral simulation model to
predict the effect of MSAs on the insurance choices of employees of small
businesses (and their families). The model predicts spending by each family in a
FFS plan, an HMO plan, an MSA, and no insurance. These predictions allow us to
compute community-rated premiums for each plan, but with firm-specific load fees.
Within each firm, employees then evaluate each option, and the firm decides
whether to offer insurance-and what type-based on these evaluations. If firms
offer insurance, we consider two scenarios: (1) all workers elect coverage; and
(2) workers can decline the coverage in return for a wage increase. PRINCIPAL
FINDINGS: In the long run, under simulated conditions, tax-advantaged MSAs could
attract 56 percent of all employees offered a plan by small businesses. However,
the fraction of small-business employees offered insurance increases only from 41
percent to 43 percent when MSAs become an option. Many employees now signing up
for a FFS plan would switch to MSAs if they were universally available.
CONCLUSIONS: Our simulations suggest that MSAs will provide a limited impetus to
businesses that do not currently cover insurance. However, MSAs could be
desirable to workers in firms that already offer HMOs or standard FFS plans. As a
result, expanding MSA availability could make it a major form of insurance for
covered workers in small businesses. Overall welfare would increase slightly.
PMID- 10778825
TI - The effect of Employee Assistance Programs use on healthcare utilization.
AB - OBJECTIVE: To estimate the effect of Employee Assistance Program (EAP) use on
healthcare utilization as measured by health claims. DATA SOURCES: A unique data
set that combines individual-level information on EAP utilization, demographic
information, and health insurance claims from 1991 to 1995 for all employees of a
large midwestern employer. STUDY DESIGN: Using "fixed-effect" econometric models
that control for unobserved differences between individuals' propensities to use
healthcare resources and the EAP, we perform our analyses in two steps. First,
for those employees who visited the EAP, we test whether post-EAP claims differ
from pre-EAP claims. Second, we combine claims data of individuals who went to an
EAP with those of individuals who did not use an EAP to test whether differences
in utilization exist between EAP users and nonusers. DATA COLLECTION METHODS:
From the EAP we obtained the date of first EAP contact for all employees who used
the service, and from the company's human resources department we obtained
limited demographic data on all employees. We obtained healthcare utilization
claims data on all employees and their dependents from the company's two
healthcare plans: a fee-for-service (FFS) plan and a health maintenance
organization (HMO) plan. PRINCIPAL FINDINGS: We found that going to an EAP
substantially increases both the probability of an alcohol, drug abuse, or mental
health (ADM) claim and the number of ADM claims in the same quarter as EAP
contact. The increased probability of an ADM claim persists for approximately 11
quarters after the initial contact, while the increased ADM charges persist for
approximately six quarters after the initial EAP contact. CONCLUSIONS: Our
results strongly suggest that the EAP is able to identify behavioral and other
health problems that may affect workplace performance and prompt EAP users to
access ADM and other healthcare. Consistent with the stated goals of many EAPs,
including the one examined in this study, this process should improve
individuals' health, family functioning, and workplace performance.
PMID- 10778826
TI - Impact of HMO market structure on physician-hospital strategic alliances.
AB - OBJECTIVE: To assess the impact of HMO market structure on the formation of
physician-hospital strategic alliances from 1993 through 1995. The two trends,
managed care and physician-hospital integration have been prominent in reshaping
insurance and provider markets over the past decade. STUDY DESIGN: Pooled cross
sectional data from the InterStudy HMO Census and the Annual Survey conducted by
the American Hospital Association (AHA) between 1993 and the end of 1995 to
examine the effects of HMO penetration and HMO numbers in a market on the
formation of hospital-sponsored alliances with physicians. Because prior research
has found nonlinear effects of HMOs on a variety of dependent variables, we
operationalized HMO market structure two ways: using a Taylor series expansion
and cross-classifying quartile distributions of HMO penetration and numbers into
16 dummy indicators. Alliance formation was operationalized using the presence of
any alliance model (IPA, PHO, MSO, and foundation) and the sum of the four models
present in the hospital. Because managed care and physician-hospital integration
are endogenous (e.g., some hospitals also sponsor HMOs), we used an instrumental
variables approach to model the determinants of HMO penetration and HMO numbers.
These instruments were then used with other predictors of alliance formation:
physician supply characteristics, the extent of hospital competition, hospital
level descriptors, population size and demographic characteristics, and
indicators for each year. All equations were estimated at the MSA level using
mixed linear models and first-difference models. PRINCIPAL FINDINGS: Contrary to
conventional wisdom, alliance formation is shaped by the number of HMOs in the
market rather than by HMO penetration. This confirms a growing perception that
hospital-sponsored alliances with physicians are contracting vehicles for managed
care: the greater the number of HMOs to contract with, the greater the
development of alliances. The models also show that alliance formation is low in
markets where a small number of HMOs have deeply penetrated the market. First
difference models further show that alliance formation is linked to HMO
consolidation (drop in the number of HMOs in a market) and hospital downsizing.
Alliance formation is not linked to changes in hospital costs, profitability, or
market competition with other hospitals. CONCLUSIONS: Hospitals appear to form
alliances with physicians for several reasons. Alliances serve to contract with
the growing number of HMOs, to pose a countervailing bargaining force of
providers in the face of HMO consolidation, and to accompany hospital downsizing
and restructuring efforts. IMPLICATIONS FOR POLICY, DELIVERY, OR PRACTICE:
Physician-hospital integration is often mentioned as a provider response to
increasing cost-containment pressures due to rising managed care penetration. Our
findings do not support this view. Alliances appear to serve the hospital's
interest in bargaining with managed care plans on a more even basis.
PMID- 10778827
TI - Outcomes monitoring and the testing of new psychiatric treatments: work therapy
in the treatment of chronic post-traumatic stress disorder.
AB - OBJECTIVE: To evaluate the effectiveness of a work therapy intervention, the
Department of Veterans Affairs (VA) Compensated Work Therapy program (CWT), in
the treatment of patients suffering from chronic war-related post-traumatic
stress disorder (PTSD); and to demonstrate methods for using outcomes monitoring
data to screen previously untested treatments. DATA SOURCES/STUDY SETTING:
Baseline and four-month follow-up questionnaires administered to 3,076 veterans
treated in 52 specialized VA inpatient programs for treatment of PTSD at
facilities that also had CWT programs. Altogether 78 (2.5 percent) of these
patients participated in CWT during the four months after discharge. STUDY
DESIGN: The study used a pre-post nonequivalent control group design. DATA
COLLECTION/EXTRACTION METHODS: Questionnaires documented PTSD symptoms, violent
behavior, alcohol and drug use, employment status, and medical status at the time
of program entry and four months after discharge from the hospital to the
community. Administrative databases were used to identify participants in the CWT
program. Propensity scores were used to match CWT participants and other
patients, and hierarchical linear modeling was used to evaluate differences in
outcomes between treatment groups on seven outcomes. PRINCIPAL FINDINGS: The
propensity scaling method created groups that were not significantly different on
any measure. No greater improvement was observed among CWT participants than
among other patients on any of seven outcome measures. CONCLUSIONS: Substantively
this study suggests that work therapy, as currently practiced in VA, is not an
effective intervention, at least in the short term, for chronic, war-related
PTSD. Methodologically it illustrates the use of outcomes monitoring data to
screen previously untested treatments and the use of propensity scoring and
hierarchical linear modeling to adjust for selection biases in observational
studies.
PMID- 10778829
TI - Routine preoperative testing before cataract surgery.
PMID- 10778828
TI - Illicit drug use and emergency room utilization.
AB - OBJECTIVE: To provide an empirical examination of the effect that chronic illicit
drug use has on emergency room (ER) utilization, controlling for the potential
biases introduced by correlation between unobservable determinants of chronic
illicit drug use and ER utilization. DATA SOURCES/STUDY SETTING: From the
National Household Survey on Drug Abuse 1994 (NHSDA94). STUDY DESIGN: Chronic
illicit drug use and ER utilization are analyzed for 5,384 females and 4,177
males in 1994. The study uses a two-stage estimation technique. In the first
stage, sociodemographic, drug use history, and drug use risk variables are used
to estimate the probability that the subject is a chronic illicit drug user
(CDU). In the second stage, the first-stage estimates provide information needed
to test for the possibility of bias in the estimation of ER utilization. This
bias is the result of the correlation between unobservable influences on the
probability that the person is a CDU and the probability that he or she uses an
ER. DATA COLLECTION/EXTRACTION METHODS: The data were collected through a
multistage stratified sampling design. With the use of this methodology, the
resulting data set provides the most comprehensive information on household drug
use. PRINCIPAL FINDINGS: Without a correction for the possibility of endogeneity
bias, chronic illicit drug use is a positive (for both males and females) and a
significant (for females only) determinant of the probability of using an ER for
medical treatment. After a correction for endogeneity, the influence of chronic
drug use remains positive and significant for females and becomes significant for
males. The corresponding change in probability for females is from 6 percent to
30 percent, while for males the increase is from an insignificant 0.1 percent to
a significant 36 percent change. CONCLUSIONS: We estimate that chronic drug-using
females and males, after adjustments for bias, increase the probability that they
use an ER by more than 30 percent compared to their casual or non-drug-using
counterparts. Therefore, policymakers and health services providers may consider
designing programs to bring primary care and prevention services to facilities
where drug users are more likely to seek access to care, within an ER setting.
PMID- 10778830
TI - Effects of influenza vaccination of health care workers on mortality of elderly
people.
PMID- 10778831
TI - Intubation ineffective in vigorous meconium-stained infants.
PMID- 10778832
TI - Estrogen-progestin increases breast cancer risk.
PMID- 10778833
TI - Screening mammography may not be effective at any age.
PMID- 10778834
TI - Do physicians who diagnose more mental health disorders generate lower health
care costs?
AB - BACKGROUND: Underrecognition and undertreatment of mental health disorders in
primary care have been associated with poor health outcomes and increased health
care costs, but little is known about the impact of the diagnoses of mental
health disorders on health care expenditures or outcomes. Our goal was to examine
the relationships between the proportion of mental health diagnoses by primary
care physicians and both health care expenditures and the risk of avoidable
hospitalizations. METHODS: We used cross-sectional analyses of claims data from
an independent practice association-style (IPA) managed care organization in
Rochester, New York, in 1995. The sample was made up of the 457 primary care
physicians in the IPA and the 243,000 adult patients assigned to their panels. We
looked at total expenditures per panel member per year generated by each primary
care physician and avoidable hospitalizations among their patients. RESULTS:
After adjustment for case mix, physicians who recorded a greater proportion of
mental health diagnoses generated significantly lower per panel member
expenditures. For physicians in the highest quartile of recording mental health
diagnoses, expenditures were 9% lower than those of physicians in the lowest
quartile (95% confidence interval, 5% - 13%). There was a trend (P = .051) for
patients of physicians in the highest quartile of recording mental health
diagnoses to be at lower risk for an avoidable hospitalization than those of
physicians in the lowest quartile. CONCLUSIONS: Primary care physicians with
higher proportions of recorded mental health diagnoses generate significantly
lower panel member costs, and their patients may be less likely to be admitted
for avoidable hospitalization conditions.
PMID- 10778835
TI - Mental health diagnoses and the costs of primary care.
PMID- 10778836
TI - The physician's role in educating patients. A comparison of mailed versus
physician-delivered patient education.
AB - BACKGROUND: Patients value receiving educational information during office
visits, but physicians often lack the time or training to satisfy this need. We
examined whether an increased physician role in educating patients is an
effective means of improving patient satisfaction. METHODS: Using a nonrandomized
controlled research design, we compared patient satisfaction with self-care
information provided by traditional direct-mail approaches and by physicians
during routine office visits. We also studied a control group of patients
receiving usual care. RESULTS: Patients who received a medical self-care book
from a physician were significantly more likely to be satisfied with their office
visit than those who received the book in the mail or those who experienced usual
care. The intervention group reported greater satisfaction with 11 out of 13
variables related to physician-patient communication and quality of care. There
were no significant differences between the control group and the direct-mail
group. CONCLUSIONS: The patients who received self-care information from their
physicians were significantly more satisfied with their care and their physician
patient communication experience than those in either the direct-mail group or
the control group. Our findings lend support to the growing evidence that
patients informed by their physicians are more satisfied with their care.
PMID- 10778837
TI - The organization and distribution of patient education materials in family
medicine practices.
AB - BACKGROUND: Millions of dollars are spent annually on the production and
distribution of patient education materials; however, there are no studies
describing their actual use by physicians. Using qualitative data from a large
comparative case study, our analysis evaluates how patient education materials
are organized and used in family practices. METHODS: Eighteen purposefully
selected family medicine practices were directly observed for 4 to 12 weeks each.
A total of 57 providers were shadowed by a research nurse, and detailed field
notes on 1600 patient encounters were recorded. A 3-member analysis team reviewed
the qualitative data and identified emergent patterns. RESULTS: Clinics' use of
patient education materials fell mostly into 2 distinct patterns. "Stockpilers"
were providers who relied on the clinic staff to develop and organize a common
library of patient education handouts. Providers with a "personal stash"
collected much smaller numbers of materials that they personally maintained.
Providers in the latter group had a known repertoire of a limited amount of
educational material and used it more often than providers with access to a
greater variety and number of handouts. In all practices, providers distributed
most handouts; staff and self-selection by patients played a minor role.
CONCLUSIONS: It appears that provider involvement and familiarity with patient
education materials are key to their use in clinical practice. Clinicians use
written patient education materials most efficiently by personally selecting and
maintaining a small number of handouts that address topics most relevant to their
practice.
PMID- 10778838
TI - Patient education in our offices.
PMID- 10778839
TI - Direct-to-consumer prescription drug advertising, 1989-1998. A content analysis
of conditions, targets, inducements, and appeals.
AB - BACKGROUND: We conducted a content analysis of consumer-targeted prescription
drug advertisements to explore trends in prevalence, shifts in the medical
conditions for which drugs are promoted, reliance on financial and nonmonetary
inducements, and appeals used to attract public interest. METHODS: We collected
the drug advertisements appearing in 18 consumer magazines from 1989 through
1998. Two judges independently coded each advertisement and placed it in a
category pertaining to the target audience, use of inducements, and product
benefits (mean kappa=0.93). We employed descriptive statistics, cross
tabulations, and curve estimation procedures. RESULTS: A total of 320 distinct
advertisements were identified, representing 101 brands and 14 medical
conditions. New advertisement and brand introductions increased dramatically
during this decade. Advertisements for drugs used for dermatologic, human
immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), and
obstetric/gynecologic conditions were most common. Almost all of the
advertisements were aimed at the potential user of the drug, not third-party
intermediaries such as parents and spouses. Although most advertisements were
gender-neutral, women were more likely to be exclusively targeted. One eighth of
the advertisements offered a monetary incentive (eg, a rebate or money-back
guarantee), and one third made an offer of additional information in printed or
audio/video form. The most common appeals used were effectiveness, symptom
control, innovativeness, and convenience. CONCLUSIONS: Consumer-directed
prescription drug advertising has increased dramatically during the past decade.
The pharmaceutical industry is turning to this type of advertising to generate
interest in its products. Our data may be useful to physicians who want to stay
abreast of the treatments that are being directly marketed to their patients.
PMID- 10778840
TI - Which medicines do our patients want from us?
AB - BACKGROUND: The prescribing of medication, whether for infections or injuries,
has come under the scrutiny of health maintenance organizations (HMOs). Our goal
was to examine patient beliefs about the usefulness of certain classes of
medications. METHODS: We surveyed 244 consecutive adult patients who presented to
an urban private family medicine practice in Georgia. RESULTS: Regardless of who
paid for prescriptions (an HMO or the patient), most people in the survey would
be satisfied with over-the-counter medications and reassurance (84% for upper
respiratory infection, 72% for muscle strain, 56% for diarrhea). Few differences
were attributable to payment status (prepaid as opposed to fee-for-service).
African Americans are less likely than whites to accept reassurance as an
appropriate treatment. CONCLUSIONS: Patients may be more willing to accept
reassurance and over-the-counter medications than is commonly believed by
physicians.
PMID- 10778841
TI - Fibro-fatty nodules and low back pain. The back mouse masquerade.
AB - BACKGROUND: Few useful interventions exist for patients with persistent low back
pain. We suggest that a fibro-fatty nodule ("back mouse") may be an identifiable
and treatable cause of this and other types of pain. METHODS: We describe 2
patients with painful nodules in the lower back and lateral iliac crest areas. In
both cases, the signs and symptoms were unusual and presented at locations
distant from the nodule. One patient complained of severe acute lower abdominal
pain, and the other had been treated for chronic recurrent trochanteric bursitis
for several years. RESULTS: In both patients, symptoms appeared to be relieved by
multiple injection of the nodule. DISCUSSION: There is agreement that back mice
exist. Referred pain from the nodules might explain the distant symptoms and
signs in these cases. Multiple puncture may be an effective treatment because it
lessens the tension of a fibro-fatty nodule. CONCLUSIONS: Randomized trials on
this subject are needed. In the meantime, physicians should keep back mice in
mind when presented with atypical and unaccountable symptoms in the lower
abdomen, inguinal region, or legs.
PMID- 10778842
TI - Does the use of electronic medical records improve surrogate patient outcomes in
outpatient settings?
AB - BACKGROUND: We reviewed the evidence regarding the effectiveness of electronic
medical records (EMRs) as tools for improving surrogate patient outcomes in the
outpatient primary care setting. METHODS: We searched the MEDLINE database (1966
1999) to find relevant articles for inclusion in the systematic review. Reference
lists of retrieved publications were also searched for relevant citations. We
included original published reports of all prospective studies evaluating the use
of hybrid or complete EMR systems as a method of improving surrogate patient
outcomes in the outpatient primary care setting. Criteria for evaluation included
the use of a random study group assignment, appropriateness of control group,
blinded assessment of outcomes, number and reasons for withdrawal of subjects,
and attempts to minimize confounding interventions. RESULTS: Seven prospective
trials of complete EMRs and 9 prospective trials of hybrid EMRs were located.
Most evaluated the impact of EMR-generated reminders on provider and patient
compliance with health maintenance interventions. Findings were equally positive
for both complete and hybrid EMRs, and all but 1 trial reported positive results.
However, the methodologic quality of the trials was modest. Design problems
included lack of concurrent control groups, non-blinded outcome assessment, and
the presence of potentially confounding concurrent interventions. CONCLUSIONS:
Evidence from published trials suggests that utilization of either complete or
hybrid EMRs can improve some surrogate outpatient care outcomes. However,
rigorous trials that evaluate their impact on morbidity and mortality, and employ
current technologies are required before widespread adoption of EMRs can be
confidently recommended.
PMID- 10778843
TI - What to do until the POEMs arrive. An endothelial example.
AB - There is a growing trend toward evidence-based medicine, in which patient
oriented data are valued more highly than disease-oriented evidence (DOEs). In
the vernacular of evidence-based medicine, the old DOEs are slowly being replaced
by POEMs (patient-oriented evidence that matters). Unfortunately, POEMs do not
yet exist to meet every family-practice need. When there are no POEMs to
determine an appropriate therapeutic choice, another decision-making method must
be used. This method includes liberal use of DOEs combined with thoughtful use of
causal pathways to provide preliminary direction. This article applies that
method to an example from the growing basic science surrounding endothelial
functioning.
PMID- 10778844
TI - Culture confirmation of negative rapid strep test results.
PMID- 10778845
TI - Vitamin E does not prevent cardiovascular events in high-risk patients.
PMID- 10778846
TI - ACE inhibitors to prevent cardiovascular events in high-risk patients.
PMID- 10778847
TI - ERT and breast cancer.
PMID- 10778848
TI - Heights and weights in an overweight population: an UPRNet study. Upper Peninsula
Research Network.
PMID- 10778849
TI - Reversing neurodegeneration: a promise unfolds.
PMID- 10778850
TI - The ABCs of floral evolution.
PMID- 10778851
TI - Mechanisms of left-right determination in vertebrates.
PMID- 10778852
TI - Paul Sigler (1934-2000).
PMID- 10778853
TI - RNAi: double-stranded RNA directs the ATP-dependent cleavage of mRNA at 21 to 23
nucleotide intervals.
AB - Double-stranded RNA (dsRNA) directs the sequence-specific degradation of mRNA
through a process known as RNA interference (RNAi). Using a recently developed
Drosophila in vitro system, we examined the molecular mechanism underlying RNAi.
We find that RNAi is ATP dependent yet uncoupled from mRNA translation. During
the RNAi reaction, both strands of the dsRNA are processed to RNA segments 21-23
nucleotides in length. Processing of the dsRNA to the small RNA fragments does
not require the targeted mRNA. The mRNA is cleaved only within the region of
identity with the dsRNA. Cleavage occurs at sites 21-23 nucleotides apart, the
same interval observed for the dsRNA itself, suggesting that the 21-23 nucleotide
fragments from the dsRNA are guiding mRNA cleavage.
PMID- 10778854
TI - Modulation of RNA polymerase by (p)ppGpp reveals a RecG-dependent mechanism for
replication fork progression.
AB - We have discovered a correlation between the ability of Escherichia coli cells to
survive damage to DNA and their ability to modulate RNA polymerase via the
stringent response regulators, (p)ppGpp. Elevation of (p)ppGpp, or certain
mutations in the beta subunit of RNA polymerase, dramatically improve survival of
UV-irradiated strains lacking the RuvABC Holliday junction resolvase. Increased
survival depends on excision and recombination proteins and relies on the ability
of RecG helicase to form Holliday junctions from replication forks stalled at
lesions in the DNA and of PriA to initiate replication restart. The role of RecG
provides novel insights into the interplay between transcription, replication,
and recombination, and suggests a general model in which recombination underpins
genome duplication in the face of frequent obstacles to replication fork
progression.
PMID- 10778855
TI - Structural basis of collagen recognition by integrin alpha2beta1.
AB - We have determined the crystal structure of a complex between the I domain of
integrin alpha2beta1 and a triple helical collagen peptide containing a critical
GFOGER motif. Three loops on the upper surface of the I domain that coordinate a
metal ion also engage the collagen, with a collagen glutamate completing the
coordination sphere of the metal. Comparison with the unliganded I domain reveals
a change in metal coordination linked to a reorganization of the upper surface
that together create a complementary surface for binding collagen. Conformational
changes propagate from the upper surface to the opposite pole of the domain,
suggesting both a basis for affinity regulation and a pathway for signal
transduction. The structural features observed here may represent a general
mechanism for integrin-ligand recognition.
PMID- 10778856
TI - Reversal of neuropathology and motor dysfunction in a conditional model of
Huntington's disease.
AB - Neurodegenerative disorders like Huntington's disease (HD) are characterized by
progressive and putative irreversible clinical and neuropathological symptoms,
including neuronal protein aggregates. Conditional transgenic models of
neurodegenerative diseases therefore could be a powerful means to explore the
relationship between mutant protein expression and progression of the disease. We
have created a conditional model of HD by using the tet-regulatable system. Mice
expressing a mutated huntingtin fragment demonstrate neuronal inclusions,
characteristic neuropathology, and progressive motor dysfunction. Blockade of
expression in symptomatic mice leads to a disappearance of inclusions and an
amelioration of the behavioral phenotype. We thus demonstrate that a continuous
influx of the mutant protein is required to maintain inclusions and symptoms,
raising the possibility that HD may be reversible.
PMID- 10778857
TI - Molecular chaperones activate the Drosophila ecdysone receptor, an RXR
heterodimer.
AB - The steroid hormone 20-hydroxyecdysone coordinates the stages of Drosophila
development by activating a nuclear receptor heterodimer consisting of the
ecdysone receptor, EcR, and the Drosophila RXR receptor, USP. We show that
EcR/USP DNA binding activity requires activation by a chaperone heterocomplex
like that required for activation of the vertebrate steroid receptors, but not
previously shown to be required for activation of RXR heterodimers. Six proteins
normally present in the chaperone complex were individually purified and shown to
be sufficient for this activation. We also show that two of the six (Hsp90 and
Hsc70) are required in vivo for ecdysone receptor activity, and that EcR is the
primary target of the chaperone complex.
PMID- 10778858
TI - Exit from G1 and S phase of the cell cycle is regulated by repressor complexes
containing HDAC-Rb-hSWI/SNF and Rb-hSWI/SNF.
AB - We present evidence that Rb forms a repressor containing histone deacetylase
(HDAC) and the hSWI/SNF nucleosome remodeling complex, which inhibits
transcription of genes for cyclins E and A and arrests cells in the G1 phase of
the cell cycle. Phosphorylation of Rb by cyclin D/cdk4 disrupts association with
HDAC, relieving repression of the cyclin E gene and G1 arrest. However, the Rb
hSWI/SNF complex persists and is sufficient to maintain repression of the cyclin
A and cdc2 genes, inhibiting exit from S phase. HDAC-Rb-hSWI/SNF and Rb-hSWI/SNF
then appear to maintain the order of cyclin E and A expression during the cell
cycle, which in turn regulates exit from G1 and from S phase, respectively.
PMID- 10778859
TI - Drosophila p53 is a structural and functional homolog of the tumor suppressor
p53.
AB - The importance of p53 in carcinogenesis stems from its central role in inducing
cell cycle arrest or apoptosis in response to cellular stresses. We have
identified a Drosophila homolog of p53 ("Dmp53"). Like mammalian p53, Dmp53 binds
specifically to human p53 binding sites, and overexpression of Dmp53 induces
apoptosis. Importantly, inhibition of Dmp53 function renders cells resistant to X
ray-induced apoptosis, suggesting that Dmp53 is required for the apoptotic
response to DNA damage. Unlike mammalian p53, Dmp53 appears unable to induce a G1
cell cycle block when overexpressed, and inhibition of Dmp53 activity does not
affect X ray-induced cell cycle arrest. These data reveal an ancestral
proapoptotic function for p53 and identify Drosophila as an ideal model system
for elucidating the p53 apoptotic pathway(s) induced by DNA damage.
PMID- 10778860
TI - Drosophila p53 binds a damage response element at the reaper locus.
AB - The tumor suppressor gene p53 regulates multiple cellular responses to DNA
damage, but the transcriptional targets that specify these responses are
incompletely understood. We describe a Drosophila p53 homolog and demonstrate
that it can activate transcription from a promoter containing binding sites for
human p53. Dominant-negative forms of Drosophila p53 inhibit both transactivation
in cultured cells and radiation-induced apoptosis in developing tissues. The cis
regulatory region of the proapoptotic gene reaper contains a radiation-inducible
enhancer that includes a consensus p53 binding site. Drosophila p53 can activate
transcription from this site in yeast and a multimer of this site is sufficient
for radiation induction in vivo. These results indicate that reaper is a direct
transcriptional target of Drosophila p53 following DNA damage.
PMID- 10778861
TI - Acute cold exposure decreases plasma leptin in women.
AB - We investigated whether cold exposure affects circulating leptin in humans. Five
women (age, 32+/-4 years; body mass index, 23.1+/-1.7 kg/m2) participated in two
separate trials. Subjects sat at room temperature ([RT] 24.8 degrees+/-0.3
degrees C) or in the cold (6.3 degrees+/-0.5 degrees C) for 90 minutes. During RT
exposure, plasma leptin and norepinephrine were unchanged over time. Cold
exposure significantly decreased plasma leptin by 14%, 17%, and 22% at 30, 60,
and 90 minutes, respectively (temperature x time interaction, P < .04). Plasma
norepinephrine increased by 400% to 500% (P < .001) and plasma glycerol increased
by 110% over baseline during cold exposure (temperature effect, P < .005). We
conclude that circulating leptin decreases during cold exposure, probably as a
result of activation of the sympathetic nervous system (SNS).
PMID- 10778862
TI - A study of human growth hormone and insulin gene regions in relation to metabolic
control of non-insulin-dependent diabetes mellitus.
AB - The possible association of human growth hormone (hGH) and insulin (INS) gene
regions with metabolic control in diabetes was investigated in 98 subjects with
non-insulin-dependent diabetes mellitus (NIDDM); 54 control subjects from the
same population were also studied. Two polymorphic restriction sites in the
region of the hGH cluster (BGLIIA and BGLIIB) show significant association with
both glycemic and hemoglobin A1c (HbA1c) levels. Mean values for plasma glucose
and HbA1c show a maximum in the BGLIIA *1/*1 genotype and a minimum in the BGLIIA
*2/*2 genotype. Mean values for plasma glucose and HbA1c show a maximum in the
BGLIIB *1/*2 genotype. The BGLIIA*2/BGLIIB*1 haplotype shows a negative
correlation with plasma glucose and HbA1c levels. Since the two markers are
located in the area surrounding the hGH-V locus, the expression of this gene in
NIDDM warrants further investigation.
PMID- 10778863
TI - Scavenging effect of nicorandil on free radicals and lipid peroxide in
streptozotocin-induced diabetic rats.
AB - Free radicals and lipid peroxide (LPO), easily formed in the diabetic state, play
an important role in the development of diabetic complications. Potentially,
nicorandil may reduce the production of free radicals and LPO in various organs.
In fact, increased LPO levels in the serum, kidney, and cardiac muscle of
diabetic (DM) rats were reduced by nicorandil treatment (N treatment). Xanthine
oxidase (XOD), which produces free radicals, was decreased in the liver and
increased in the kidney of DM rats compared with control rats, and these changes
were prevented by N treatment. The concentration of Cu, Zn-superoxide dismutase
(SOD) decreased in the cardiac muscle and increased in the kidney of DM rats, and
these changes returned to normal after N treatment. The decreased concentration
of Mn-SOD in the liver, kidney, and cardiac muscle from DM rats was also reversed
by N treatment. The changes in catalase and glutathione peroxidase (GSH-PX)
activities in DM rats were not improved effectively by N treatment. Another K
adenosine triphosphate (K-ATP) channel opener, tilisolol hydrochloride, had an
effect similar to that of nicorandil. The effects of nicorandil and tilisolol
were studied only in DM rats. These data imply that N treatment, as an
antioxidative therapy, may be beneficial in preventing diabetic complications due
to lipoperoxidation and free radicals in DM rats.
PMID- 10778864
TI - Linkage and association studies of the lipoprotein lipase gene with postheparin
plasma lipase activities, body fat, and plasma lipid and lipoprotein
concentrations: the HERITAGE Family Study.
AB - Lipoprotein lipase (LPL) is responsible for the hydrolysis of triglyceride (TG)
rich lipoproteins. The aims of the present study were (1) to test for potential
linkages (sib-pair method) between postheparin plasma lipase (lipoprotein and
hepatic lipase) activities, body fatness, plasma lipid concentrations, and LPL
polymorphisms (Ser447Ter and a tetranucleotide repeat) and microsatellite markers
flanking the LPL locus (D8S261 and D8S258); and (2) to investigate associations
between the LPL Ser447Ter (S447X) polymorphism and these phenotypes. Data on 190
parents and 312 adult offspring from 99 Caucasian families participating in the
HERITAGE Family Study were available for this study. Data were adjusted for the
effects of age within sex, and lipases, lipid variables, and abdominal visceral
fat were further adjusted for fat mass. A suggestive linkage was observed only
between the S447X polymorphism and very-low-density (VLDL)-apolipoprotein B (apo
B) (332 sib-pairs, P = .013). The S447X polymorphism was not associated with body
fat phenotypes or postheparin plasma LPL (PH-LPL) activity (men, P = .19; women,
P = .47). In contrast, the X447 allele carriers had lower plasma TG (men and
women, P = .01), VLDL-TG (men and women, P = .01), and VLDL-apo B (men and women,
P = .009). The relationships between the X447 allele and plasma TG, VLDL-TG, and
VLDL-apo B in both genders were observed in obese (body mass index [BMI] > or =
30 kg/m2) but not in normal-weight (BMI < 25 kg/m2) subjects. Thus, the S447X
polymorphism of the LPL gene is not associated with body fatness and postheparin
plasma lipase activities. However, the obese carriers of the X447 allele have
plasma TG, VLDL-TG, and plasma cholesterol/high-density lipoprotein cholesterol
(HDL-C) levels equivalent to those of normal-weight sedentary adults.
PMID- 10778865
TI - Voglibose administration before the evening meal improves nocturnal hypoglycemia
in insulin-dependent diabetic patients with intensive insulin therapy.
AB - Nocturnal hypoglycemia is one of the serious complications of intensive insulin
therapy in patients with insulin-dependent diabetes mellitus (IDDM; type 1 DM).
We assessed the effect of voglibose (alpha-glucosidase inhibitor) administration
before the evening meal on nocturnal hypoglycemia in IDDM patients with intensive
insulin therapy. Ten IDDM patients received 0.3 mg voglibose just before the
evening meal for 5 days. The diet and insulin regimen were not changed throughout
the study. Nocturnal plasma glucose levels (10 PM, 3 AM, and 7 AM) were studied
in these patients before and during voglibose administration. Blood glucose
levels were measured at 3 AM before and during voglibose treatment. The mean
plasma glucose level at 3 AM was 3.4+/-0.4 mmol/L before voglibose treatment and
7.3+/-1.0 mmol/L during treatment. Plasma glucose at 3 AM was elevated in 9 of 10
patients with voglibose. The decrease in plasma glucose from 10 PM to 3 AM was
6.5+/-0.8 mmol/L before voglibose administration but 3.2+/-0.9 mmol/L during
treatment (P < .01). The hypoglycemia rate was 52% (17 of 33 nights) before
voglibose administration but only 9.1% (3 of 33 nights) during treatment. We
conclude that voglibose administration before the evening meal improves nocturnal
hypoglycemia in IDDM patients with intensive insulin therapy.
PMID- 10778866
TI - Effect of tyrosine intake on the rate of phenylalanine hydroxylation in adult
males.
AB - This study evaluated the effect of varying levels of tyrosine intake on the
estimation of phenylalanine hydroxylation. Healthy men were fed 1 g protein kg(
1) x d(-1) for a 2-day period. On the third day, subjects consumed a formula diet
containing 1 g protein kg(-1) x d(-1) hourly over 10 hours, and primed hourly
oral doses of L-[15N]phenylalanine and L-[3,3-2H2]tyrosine for the last 6 hours.
Each subject was studied at 7 levels of tyrosine intake (3.0, 4.5, 6.0, 7.5, 9.0,
10.5, and 12.0 mg x kg(-1) x d(-1)) at a constant intake of phenylalanine (9 mg x
kg(-1) x d(-1), 4.55 micromol x kg(-1) x h(-1)). Phenylalanine hydroxylation was
estimated from the ratio of plasma amino acid isotope enrichment of
[15N]phenylalanine and [15N]tyrosine and the tyrosine flux estimated from
[2H2]tyrosine enrichment. Phenylalanine and tyrosine fluxes showed no significant
response to alterations in the intake of tyrosine. Linear regression analysis
showed a significant response such that the rate of phenylalanine hydroxylation
decreased as tyrosine intake increased (R2 = .21; P = .003). The mean rates of
phenylalanine hydroxylation were 3.89 to 8.06 micromol x kg(-1) x h(-1). Given
model uncertainties, the apparent protein breakdown observed at tyrosine intake
levels less than 10.5 mg x kg(-1) x d(-1), and the significant differences
observed between the present data and our prior data, we cannot estimate the
tyrosine requirement with any degree of certainty with the present hydroxylation
results.
PMID- 10778867
TI - Elevation of plasma fatty acids by ten-hour intralipid infusion has no effect on
basal or glucose-stimulated insulin secretion in normal man.
AB - There is controversy over the effect of free fatty acids (FFAs) on insulin
secretion. Previous studies have shown opposite effects of short- and long-term
exposure to elevated concentrations of FFAs. We studied 8 normal subjects (mean
age, 30 years; mean body mass index, 23.4 kg/m2) on 2 occasions. Each had a 10
hour overnight infusion of Intralipid 20% (Pharmacia, Milton Keynes, UK) with
simultaneous infusion of heparin (0.4 U/kg body weight/min) or a control infusion
of saline (150 mmol/L). Insulin secretion was assessed immediately after
completion of the 10-hour infusion by an intravenous glucose tolerance test.
Results were analyzed using paired ttests. Intralipid infusion caused an increase
in plasma FFAs of more than 9-fold (P < .01), with a simultaneous increase in
glycerol (P < .01) and hydroxybutyrate (P < .01). There was no difference in
blood glucose concentrations during the infusion or intravenous glucose tolerance
test. Similarly, insulin secretion was not significantly different during
Intralipid infusion or in the intravenous glucose tolerance test (peak insulin
achieved in glucose tolerance test, P = .51; total insulin secretion during
intravenous glucose tolerance test, P = .27). In conclusion, after increasing
plasma FFA concentrations over 9-fold during a 10-hour infusion of Intralipid and
heparin, we found no difference in basal or glucose-stimulated insulin secretion.
PMID- 10778868
TI - Correlation between fasting plasma glucose and two-hour plasma glucose during
oral glucose tolerance test in South Indians.
AB - The diagnostic criteria for diabetes have been recently revised and the fasting
plasma glucose (FPG) level reduced to 126 mg/dL, since the earlier cutoff of 140
mg/dL was considered to correspond to a much higher level than the 2-hour
postglucose (2 h PG) value of 200 mg/dL. However, there are few data directly
correlating FPG and 2 h PG during an oral glucose tolerance test (OGTT). This
study reports on a retrospective analysis of 5,936 OGTTs performed at a diabetes
center in South India and attempts to correlate the FPG and 2 h PG values. Using
a 2 h PG of 200 mg/dL or higher as the diagnostic criterion, 46.7% of the cohort
had diabetes. The corresponding values using the old FPG of 140 mg/dL or higher
and the new FPG of 126 mg/dL or higher were 31.7% and 39.8%, respectively. If the
FPG was further reduced to 118 mg/dL, the "diabetic yield" increased to 45.8%,
ie, it approached the figures based on a 2 h PG of > or =200 mg/dL. Various
regression equations were used to correlate FPG and 2 h PG values. When FPG was
used as the dependent variable, the semilogarithmic regression equation provided
the best fit, and using this model, the 2 h PG of 200 mg/dL corresponds to a FPG
of 118 mg/dL. When the 2 h PG was used as the dependent variable, the log-log
model provided the best fit, and using this model, a 2 h PG of 200 mg/dL
corresponds to a FPG of 118 mg/dL. Thus, a FPG of 118 mg/dL seems to correlate
with a 2 h PG of 200 mg/dL in South Indians.
PMID- 10778869
TI - Effect of venous drainage site on insulin action after pancreas transplantation
in the rat--is there insulin resistance and a risk for atherosclerosis?
AB - The aim of the present study was to determine the influence of the venous
drainage site on insulin homeostasis and the possible risk for atherosclerosis
development after pancreas transplantation. We studied inbred rats that received
pancreas transplants with either systemic (STX) or portal (PTX) venous drainage
after prior induction of diabetes with streptozotocin and sham-operated controls.
The observation period was 6 months. Fasting plasma glucose and insulin levels
were similar in all 3 groups, but fasting plasma glucagon levels were elevated in
STX (mean +/- SEM, 282+/-35 ng/L) in comparison to PTX rats (119+/-9 ng/L, P <
.05), although the difference versus the control group (191+/-31 ng/L) was
insignificant. Glucose utilization and hepatic glucose production (HGP), assessed
by a dose-response euglycemic-hyperinsulinemic clamp in combination with
tritiated glucose infusion, were similar in all 3 groups. The groups were also
similar with respect to the molar ratio of plasma C-peptide and insulin during
basal steady state and the metabolic clearance rate (MCR) of insulin during the
clamp studies, suggesting an unchanged hepatic insulin extraction (HIE) after
transplantation with either technique. Factors known to be related to
atherosclerosis, ie, blood pressure, intracellular magnesium, and fasting levels
of plasma cholesterol, triglycerides, and high-density lipoprotein (HDL) and low
density lipoprotein (LDL) cholesterol, were similar in all 3 groups. Light
microscopy of the aorta showed a slightly thicker intima in STX rats (24.3+/-0.5
microm, P < .05) versus PTX rats (21.4+/-0.7 microm) and control (21.4+/-0.6
microm); however, atherosclerosis-like lesions were absent in all 3 groups. In
conclusion, in a rat model with streptozotocin-diabetes and pancreas
transplantation but no need for immunosuppression, both systemic and portal
venous drainage avoid peripheral and hepatic insulin resistance; also, there is
no increased risk for atherosclerosis.
PMID- 10778870
TI - Intramuscular lipid content is increased in obesity and decreased by weight loss.
AB - The triglyceride content of skeletal muscle samples determined by lipid
extraction correlates with the severity of insulin-resistant glucose metabolism
in muscle. To determine whether this reflects increased triglyceride within
muscle fibers and to test the hypothesis that the lipid content in muscle fibers
is increased in obesity, the present study was undertaken using quantitative
histochemistry of Oil Red O staining of vastus lateralis muscle. A percutaneous
muscle biopsy was performed in 9 lean subjects, 15 obese subjects without type 2
diabetes mellitus (DM), and 10 obese subjects with type 2 DM (body mass index
[BMI], 23.4+/-1.0, 33.6+/-0.6, and 36.0+/-1.1 kg x m(-2) for lean, obese, and DM,
respectively). Eight obese and 7 DM subjects had a weight loss and reassessment
of muscle lipid content. Transverse muscle cryosections were examined by light
microscopy with quantitative image analysis (grayscale images obtained by analog
to digital conversion) to determine a lipid accumulation index (LAI) based on the
percentage of cross-sectional fiber area occupied by lipid droplets. Muscle fiber
lipid content was greater in obese individuals with DM than in lean individuals
(3.62%+/-0.65% v 1.42%+/-0.28%, P < .05) but was not different in obese
individuals without DM (2.53%+/-0.41%). Weight loss reduced the LAI from 3.43%+/
0.53% to 2.35%+/-0.31%. In summary, lipid accumulation within muscle fibers is
significantly increased in obesity and is reduced by weight loss. This provides
important information regarding the accumulation and distribution of skeletal
muscle triglyceride in type 2 DM and obesity.
PMID- 10778871
TI - Effect of stanol ester on postabsorptive squalene and retinyl palmitate.
AB - Stanol ester dissolved in margarine inhibits cholesterol absorption in general
and, despite increasing cholesterol synthesis, decreases serum total and low
density lipoprotein (LDL) cholesterol levels, but its effects on postprandial
lipid metabolism are unknown. We performed fat tolerance tests in 11 men at
baseline and during short-term stanol ester consumption without and with stanol
esters added to the test meal also containing retinol and squalene. Cholesterol,
triglycerides, retinyl palmitate, and squalene were analyzed in plasma,
chylomicrons, and very-low-density lipoprotein (VLDL) at baseline and 3, 4, 6, 9,
12, and 24 hours after the test meal. Serum total and LDL cholesterol only tended
to diminish after the 2-week stanol ester consumption. However, the proportion of
plasma plant sterol and cholesterol-precursor sterol to cholesterol was
significantly altered, suggesting that cholesterol absorption was diminished and
cholesterol synthesis was increased. Postprandial peak times of squalene and
retinyl palmitate in plasma, chylomicrons, and VLDL were significantly reduced by
stanol esters, but their concentrations in chylomicrons were unchanged. Stanol
esters reduced the VLDL squalene peak concentration by 23% (P < .05) and the
incremental area under the curve (AUIC) in plasma and VLDL by 22% and 32% (P <
.01 for both). Chylomicron remnant metabolism measured with triglycerides only
tended to diminish. The effects of stanol esters in the diet only and both in the
diet and with supplementation did not differ significantly. We conclude that
dietary stanol esters reduce postprandial lipoproteins measured with dietary
retinyl palmitate and especially squalene, and the reduction is observed even
though serum total and LDL cholesterol are only inconsistently decreased after
short-term stanol ester consumption.
PMID- 10778872
TI - Gemfibrozil metabolite inhibits in vitro low-density lipoprotein (LDL) oxidation
and diminishes cytotoxicity induced by oxidized LDL.
AB - We hypothesized that M1, a metabolite of gemfibrozil, may have antioxidant
properties because of its hydroxylated phenol ring, 5-(4-hydroxy-2,5-dimethyl
phenoxy)-2,2-dimethyl pentanoic acid. The susceptibility of low-density
lipoprotein (LDL) to oxidative modification was investigated by a method using
2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile [MeO-AMVN]) or Cu2+ as previously
reported. Conjugated dienes (CDs), lipid hydroperoxide (LPO), and thiobarbituric
acid-reactive substances (TBARS) were measured to evaluate the degree of LDL
oxidation. Oxidized LDL (OxLDL), which is used for cytotoxicity studies, was
prepared by the dialysis method using Cu2+ as the oxidation inducer. Cytotoxicity
induced by OxLDL was studied in J774 macrophages by colorimetric assay using 3
[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT assay). The
oxidative modification of LDL was inhibited by M1 in a dose-dependent manner. The
antioxidant effect of M1 on LDL oxidation was diminished by dialysis of the LDL
incubated with M1 against phosphate-buffered saline (PBS), suggesting that M1 is
hydrophilic rather than lipophilic. M1 diminished the cytotoxicity induced by
OxLDL, although it was milder versus probucol. These data suggest that this
gemfibrozil metabolite has an antioxidant effect on LDL, and thus M1 may
contribute to the antiatherogenic effects of gemfibrozil.
PMID- 10778873
TI - Preoperative feeding does not reverse postoperative insulin resistance in
skeletal muscle in the rat.
AB - Metabolic studies on injured and postoperative patients have shown impaired
glucose disposal in peripheral tissues after trauma. Using small-bowel resection
as a model of surgical trauma, we investigated whether substrate availability
could ameliorate the changes in muscle glucose uptake induced by trauma. We also
studied the effect of preoperative feeding on postoperative insulin-stimulated
insulin receptor substrate-1 (IRS-1)-associated phosphatidylinositol (PI) 3
kinase activity in both Wistar rats and genetically non-insulin-dependent
diabetic Goto-Kakazaki rats (GK rats). Serum glucose, insulin, plasma
epinephrine, lactate, and plasma nonesterified free fatty acids (NEFAs) were
measured as indicators of the metabolic state and surgical stress. Insulin
stimulated glucose transport was significantly reduced in fed traumatized Wistar
rats compared with fed nontraumatized rats (P < .05). Significant increases in in
vivo insulin-stimulated IRS-1-associated PI 3-kinase activity were found in fed
traumatized Wistar rats compared with fed nontraumatized Wistar rats and fasted
traumatized Wistar rats, as well as fed traumatized GK rats compared with fed
nontraumatized GK animals (all P < .017). Serum insulin concentrations were
significantly reduced in fed traumatized Wistar and GK rats compared with the
respective fed nontraumatized groups (both P < .01). Serum glucose levels were
significantly elevated in fed traumatized GK rats compared with fed
nontraumatized animals (P < .01). In the present study, preoperative feeding did
not prevent a postoperative reduction in insulin-stimulated glucose transport in
skeletal muscle. The finding that insulin-stimulated PI 3-kinase activity
increased after trauma in both Wistar and GK rats indicates that postoperative
insulin resistance is not caused by an impairment in the early steps of the
insulin signaling pathway. The postoperative decreases in serum insulin despite
high blood glucose suggest that trauma impairs the insulin response to
hyperglycemia.
PMID- 10778874
TI - Decreased hepatic expression of the low-density lipoprotein (LDL) receptor and
LDL receptor-related protein in aging rats is associated with delayed clearance
of chylomicrons from the circulation.
AB - Aging in both humans and rats is associated with the development of insulin
resistance and the ensuing alterations in the plasma lipoprotein profile. In this
study, young (2 months) and old (15 months) Sprague-Dawley (SD) rats were used to
investigate age-related alterations in the chylomicron clearance pathway.
Clearance from the blood of an intravenously injected bolus of 14C-labeled
cholesterol ester (CE) and 3H-labeled triacylglycerol (TAG) lymph chylomicrons
was markedly delayed in the old rats (P < .05). Hepatic expression of the two
principal receptors of chylomicron remnant removal, the low-density lipoprotein
(LDL) receptor and LDL receptor-related protein (LRP), was determined by ligand
blotting and immunoblotting. The old rats expressed 43%+/-7% of the level of LDL
receptor in the young animals (P < .05) and 45%+/-16% of the corresponding level
of LRP (P < .05). The results suggest that the delayed clearance of chylomicron
remnants in this animal model of aging and insulin resistance is due, at least in
part, to a decrease in the hepatic expression of LDL receptor and LRP.
PMID- 10778875
TI - Comparison of fasting plasma leptin concentrations in healthy subjects with high
and low plasma insulin.
AB - This study was initiated to evaluate the role of hyperinsulinemia in the
regulation of fasting plasma leptin. We measured plasma leptin and insulin
concentrations in 404 healthy nondiabetic subjects. For analytical purposes, the
population was divided into quartiles on the basis of the lowest (quartile 1) and
highest (quartile 4) plasma insulin response to oral glucose, and fasting plasma
leptin values in these 2 dichotomous groups were compared. The total plasma
integrated insulin response was 4-fold greater in quartile 4, associated with
significantly higher (P < .001) fasting plasma leptin (12.60+/-0.85 v8.53+/-0.56
ng/mL). Fasting plasma leptin concentrations remained significantly higher in the
hyperinsulinemic quartile when comparisons were made after subdividing the
population on the basis of gender, body mass index (BMI), or waist to hip ratio
(WHR). These results demonstrate that fasting plasma leptin concentrations are
significantly higher in hyperinsulinemic individuals, and this difference is
independent of either overall or central obesity.
PMID- 10778876
TI - High-fat diet feeding reduces the diurnal variation of plasma leptin
concentration in rats.
AB - To investigate the response of plasma leptin and its diurnal variation to graded
levels of dietary fat intake, adult (486.8+/-10.8 g), male rats (N = 52) were fed
diets containing 12%, 28%, 44%, and 60% fat for 4 weeks. The body weight gain and
abdominal fat pad weight were higher (P < .05) in groups fed diets containing 44%
and 60% fat compared with the two diets containing less fat. There were no
significant differences in terms of body weight or fat pad weight between animals
fed the two diets with higher fat content or between animals fed the two lower
fat diets. Twenty-four-hour energy expenditure was not different among the
dietary fat groups. After 3 days on the experimental diets, plasma leptin
increased (P < .03) in all dietary groups. The increases in leptin in animals fed
12% and 28% fat diets occurred primarily in the morning. In contrast, in groups
fed the two diets containing higher fat content, leptin levels increased mainly
in the afternoon. As a result, the daily variation in leptin increased (P < .05)
in the two groups fed lower-fat diets, but decreased (P < .04) in animals fed the
two higher-fat diets. These data demonstrate that short-term high-fat diet
feeding abolished the diurnal fluctuation of plasma leptin levels, which may
prevent proper leptin function and eventually contribute to the development of
obesity.
PMID- 10778877
TI - Effect of dietary omega-3 fatty acids and chronic ethanol consumption on reverse
cholesterol transport in rats.
AB - We previously showed that chronic ethanol feeding leads to a decrease of
apolipoprotein E (apoE) in high-density lipoprotein (HDL), whereas supplementing
this diet with 2.8% of total dietary calories as omega3-fatty acids (omega3FAs)
restores HDL-apoE to the control values. Since HDL containing apoE plays a major
role in reverse cholesterol transport (RCT), we measured the effects chronic
ethanol intake and omega3-FAs on RCT in the present study. Four groups of rats,
control normal fat (CN), alcohol-normal fat (AN), control omega3FA fat (CF), and
alcohol-omega3FA fat (AF), were fed their respective diets for 8 weeks, after
which hepatocytes and HDLs from each group were evaluated for RCT capacity
(cholesterol efflux from macrophages and uptake by liver cells). Compared with
the control diet (CN), chronic ethanol (AN) feeding inhibited the cholesterol
efflux capacity of HDL by 21% (P < .01), whereas omega3FA feeding (2.8% of total
dietary calories) stimulated this capacity by 79% (P < .01) and 25% (P < .01) in
CF and AF rats, respectively. With respect to cholesterol uptake by the liver,
there were no significant 3-way or 4-way interactions between the 4 factors, HDL
alcohol, HDL-fish oil, hepatocyte-alcohol, and hepatocyte-fish oil. The main
effects for HDL-alcohol, HDL-fish oil, and hepatocyte-alcohol were all highly
significant (P = .0001, .0001, and .007, respectively). There was a significant
HDL-alcohol and HDL-fish oil interaction (P = .0001). Hepatocyte-alcohol was not
a factor in any 2-way interactions. Our study indicates no evidence of an
interaction between the effects of omega3FAs and the effects of alcohol on
hepatocytes in terms of RCT function. Thus, feeding as little as 2.8% of the
total dietary calories as omega3FA not only restored the impaired RCT function of
HDL caused by chronic ethanol intake, but also enhanced by severalfold the
ability of HDL to promote RCT even in normal animals.
PMID- 10778878
TI - Blood lipid response to 20 weeks of supervised exercise in a large biracial
population: the HERITAGE Family Study.
AB - We studied the effects of 20 weeks of supervised cycle-ergometer exercise on
plasma lipids in 675 healthy, sedentary, normolipidemic white and black men and
women aged 17 to 65 years, participating in the HERITAGE Family Study. Fasting
plasma lipids were assessed twice at baseline and 24 and 72 hours after the last
exercise session and adjusted for plasma volume changes. No significant
differences from the mean baseline levels were observed for total, low-density
lipoprotein (LDL), and very-low-density lipoprotein (VLDL) cholesterol and
apolipoprotein B (Apo B). A significant reduction (P < .01) from baseline levels
in plasma total and VLDL triglycerides was observed only in the 24-hour
posttraining specimens, reflecting a response to the last bout of exercise. High
density lipoprotein (HDL) cholesterol increased 3.6% for the combined group,
primarily due to an increase in HDL2, with an associated increase in Apo A-1 (P <
.001). No significant differences were noted in the HDL response by sex, race, or
age. An inverse correlation (r = -.241) was observed between the increase in HDL
cholesterol and change in body fat only in men, and the increase in HDL
cholesterol was unrelated to the change in maximal oxygen uptake (VO2max).
PMID- 10778879
TI - Tissue-specific actions of antidiabetic thiazolidinediones on the reduced fatty
acid oxidation in skeletal muscle and liver of Zucker diabetic fatty rats.
AB - Fatty acid overload has been proposed as a cause of decreased responsiveness in
the major insulin target tissues of the body such as muscle and liver tissue. We
therefore investigated fatty acid oxidation in soleus muscle and liver isolated
from Zucker diabetic fatty (ZDF) rats treated with thiazolidinediones, a new
class of antidiabetic agents. 14CO2 production from [14C]palmitic (C16:0) acid
was lower in the soleus muscle and liver of ZDF rats versus lean rats (P < .05).
When administered orally to ZDF rats for 2 weeks, the thiazolidinediones
troglitazone (300 mg/kg) and KRP-297 (10 mg/kg) increased palmitic acid oxidation
in the soleus muscle of ZDF rats (P < .05). KRP-297, but not troglitazone,
increased palmitic acid oxidation in the liver of ZDF rats (P < .05), and both
troglitazone and KRP-297 inhibited triglyceride accumulation in the skeletal
muscle of ZDF rats. Hepatic triglyceride accumulation in ZDF rats was inhibited
by KRP-297, but not by troglitazone. A reduction of fatty acid oxidation in the
liver of ZDF rats and an increase in response to KRP-297 were observed only when
C16:0 and C18:0 fatty acids, not C8:0, were used as substrates. Thus, there were
defects in fatty acid catabolic activity and triglyceride accumulation in the
soleus muscle and liver of ZDF rats. These results indicate that KRP-297 has
advantages over troglitazone in the amelioration of these lipid metabolic
abnormalities in insulin resistance associated with obesity.
PMID- 10778880
TI - Implication of insulin and nutritional factors in the regulation of intestinal
galactosyltransferase activity during postnatal development.
AB - In the rat small intestine, galactosyltransferases are the enzymes implicated in
the biosynthesis of glycoproteins of the brush-border membranes and mucins.
During postnatal development, the circulating insulin level increased at weaning
in parallel with the activities of intestinal galactosyltransferases on O-glycans
and N-glycans. This study deals with the role of insulin in the regulation of
galactosyltransferase activities during postnatal development. The treatment of
immature suckling rats with insulin induced a precocious increase in the
activities of the O-glycan and N-glycan galactosyltransferases, partly
reproducing the increase in galactosyltransferase activity normally found at
weaning, since the O-glycan galactosyltransferase activity increased more quickly
than the N-glycan galactosyltransferase activity. The sensitivity of the two
galactosyltransferase activities to insulin disappeared after weaning, a period
when drastic diet changes occur. In 22-day-old rats submitted to prolonged
nursing (high-fat diet), the activities of the O-glycan and N-glycan
galactosyltransferases were lower than those found in age-matched normally weaned
rats (high-carbohydrate diet), indicating a delay in the maturation of the
intestine of prolonged-nursing rats. The circulating insulin level of these
animals stayed lower than that of the age-matched weaned rats. When the prolonged
nursing animals were treated with insulin, the O-glycan and N-glycan
galactosyltransferase activities reached levels similar to those of the weaned
rats. These observations suggest that insulin is one of the maturation factors
for intestinal glycoprotein galactosylation and may be partly responsible for the
natural enhancement of intestinal galactosyltransferase activities observed
during postnatal development in relation to the dietary changes at weaning.
PMID- 10778881
TI - Inhibition of insulin gene expression by long-term exposure of pancreatic beta
cells to palmitate is dependent on the presence of a stimulatory glucose
concentration.
AB - Long-term exposure of pancreatic beta cells to elevated levels of fatty acids
(FAs) impairs glucose-induced insulin secretion. However, the effects of FAs on
insulin gene expression are controversial. We hypothesized that FAs adversely
affect insulin gene expression only in the presence of elevated glucose
concentrations. To test this hypothesis, isolated rat islets were cultured for up
to 1 week in the presence of 2.8 or 16.7 mmol/L glucose with or without 0.5
mmol/L palmitate. Insulin release, insulin content, and insulin mRNA levels were
determined at the end of each culture period. Palmitate increased insulin release
at each time point independently of the glucose concentration. In contrast,
insulin content was unchanged in the presence of palmitate at 2.8 mmol/L glucose,
but was markedly decreased in the presence of 0.5 mmol/L palmitate and 16.7
mmol/L glucose after 2, 3, and 7 days of culture. In the presence of a basal
concentration of glucose, insulin mRNA levels were transiently increased by
palmitate at 24 hours but were unchanged thereafter. In contrast, palmitate
significantly inhibited the stimulatory effects of 16.7 mmol/L glucose on insulin
mRNA levels after 2, 3, and 7 days. To determine whether the inhibitory effect of
palmitate on glucose-stimulated insulin mRNA levels was associated with decreased
insulin promoter activity, HIT-T15 cells were cultured for 24 hours in 11.1
mmol/L glucose in the presence or absence of palmitate, and insulin gene promoter
activity was measured in transient transfection experiments using the insulin
promoter-reporter construct INSLUC. INSLUC activity was decreased more than 2
fold after 24 hours of exposure to 0.5 mmol/L palmitate. We conclude that long
term exposure of pancreatic beta cells to palmitate decreases insulin gene
expression only in the presence of elevated glucose concentrations, in part
through inhibition of insulin gene promoter activity.
PMID- 10778882
TI - Effect of soy protein foods on low-density lipoprotein oxidation and ex vivo sex
hormone receptor activity--a controlled crossover trial.
AB - Plant-derived estrogen analogs (phytoestrogens) may confer significant health
advantages including cholesterol reduction, antioxidant activity, and possibly a
reduced cancer risk. However, the concern has also been raised that
phytoestrogens may be endocrine disrupters and major health hazards. We therefore
assessed the effects of soy foods as a rich source of isoflavonoid phytoestrogens
on LDL oxidation and sex hormone receptor activity. Thirty-one hyperlipidemic
subjects underwent two 1-month low-fat metabolic diets in a randomized crossover
study. The major differences between the test and control diets were an increase
in soy protein foods (33 g/d soy protein) providing 86 mg isoflavones/2,000
kcal/d and a doubling of the soluble fiber intake. Fasting blood samples were
obtained at the start and at weeks 2 and 4, with 24-hour urine collections at the
end of each phase. Soy foods increased urinary isoflavone excretion on the test
diet versus the control (3.8+/-0.7 v 0.0+/-0.0 mg/d, P < .001). The test diet
decreased both oxidized LDL measured as conjugated dienes in the LDL fraction
(56+/-3 v 63+/-3 micromol/L, P < .001) and the ratio of conjugated dienes to LDL
cholesterol (15.0+/-1.0 v 15.7+/-0.9, P = .032), even in subjects already using
vitamin E supplements (400 to 800 mg/d). No significant difference was detected
in ex vivo sex hormone activity between urine samples from the test and control
periods. In conclusion, consumption of high-isoflavone foods was associated with
reduced levels of circulating oxidized LDL even in subjects taking vitamin E,
with no evidence of increased urinary estrogenic activity. Soy consumption may
reduce cardiovascular disease risk without increasing the risk for hormone
dependent cancers.
PMID- 10778883
TI - Plasma insulin concentration is more tightly linked to plasma leptin
concentration than is the body mass index.
AB - This study tested the hypothesis that the integrated plasma insulin response to
oral glucose is a more sensitive predictor of the fasting plasma leptin
concentration than the body mass index (BMI) or waist to hip ratio (WHR). For
this purpose, we determined the fasting plasma leptin concentration and plasma
insulin response to a 75-g oral glucose challenge in 76 healthy female subjects,
with a BMI of 19.1 to 36.6 kg/m2 and a WHR of 0.57 to 1.1. The results
demonstrated that fasting plasma leptin concentrations were significantly
correlated with both the BMI (r = .64, P < .001) and the plasma insulin response
to glucose (r = .61, P < .001), but not with the WHR (r = .27). Since the BMI and
the insulin response were also significantly related (r = .34, P = .003),
multivariate analysis was performed to determine if the BMI and insulin response
were independent determinants of the fasting leptin concentration. This analysis
indicated that both the BMI and insulin response were significantly related to
plasma leptin (P < .001). To pursue this issue further, the population was
divided into tertiles on the basis of the (1) plasma leptin concentration, (2)
BMI, and (3) integrated insulin response. The two variables that were most
closely linked to each other were the leptin concentration and insulin response.
In contrast, the BMI was relatively easily disassociated from the other two
variables. These results indicate that while both the plasma insulin response to
glucose and the BMI are significantly associated with the fasting plasma leptin
concentration, the plasma insulin response appears more closely associated with
the plasma leptin concentration.
PMID- 10778884
TI - Evaluation of the circadian profiles of serum dehydroepiandrosterone (DHEA),
cortisol, and cortisol/DHEA molar ratio after a single oral administration of
DHEA in elderly subjects.
AB - Aging is associated with a selective decline in circulating levels of
dehydroepiandrosterone (DHEA) and its sulfate, with no major changes in cortisol
secretion. In young subjects, serum levels of both DHEA and cortisol are
regulated according to a circadian rhythm, and an age-related attenuation of
DHEA, but not cortisol, circadian rhythmicity has been reported. Several trials
have evaluated the effects of DHEA supplementation in elderly subjects, although
the results are still controversial. However, no data are available on the 24
hour profile of DHEA circulating levels in elderly subjects with DHEA
administration. In the present study, we evaluated the circadian rhythms of DHEA,
cortisol, and the cortisol/DHEA molar ratio in old subjects treated with either
placebo (old-PL) or a single 50-mg dose of DHEA (old-D), both administered orally
at 0700 hours. For each variable, the circadian profiles were compared with those
obtained in young control subjects. The group of young subjects displayed a
circadian rhythm for both DHEA and cortisol serum concentrations but no rhythm
for the cortisol/DHEA molar ratio. In the old-PL group, the circadian rhythm of
DHEA was completely abolished, whereas significant rhythms for both cortisol and
the cortisol/DHEA molar ratio were observed. Particularly, at each time point,
the cortisol/DHEA molar ratio was significantly higher in these subjects versus
the young group. In the old-D group, the circadian rhythm of DHEA was completely
restored and was comparable to that observed in the young group. Analogous to the
observations in young subjects, the profile of the cortisol/DHEA molar ratio in
old-D subjects did not display any circadian rhythmicity, the values being almost
completely comparable to those observed in young controls. Our data demonstrate
that the circadian rhythm of DHEA is totally abolished in elderly subjects. A
single 50-mg dose of DHEA administered orally at 0700 hours restores the
circadian rhythmicity of serum DHEA and almost completely normalizes the 24-hour
profile of the cortisol/DHEA molar ratio in old subjects without affecting the
cortisol circadian rhythm.
PMID- 10778885
TI - Age-associated decrease in plasma cholesterol and changes in cholesterol
metabolism in homozygous Watanabe heritable hyperlipidemic rabbits.
AB - We examined the cholesterol metabolism of homozygous Watanabe heritable
hyperlipidemic (WHHL) rabbits, an animal model deficient in low-density
lipoprotein (LDL) receptors, to clarify the mechanism of the age-associated
decrease of plasma total cholesterol, one of the properties of WHHL rabbits. The
rabbits were examined at several ages: after weaning at 3 months, at sexual
maturation at 6 months, at 12 months, and at 24 months, equivalent to about 35
years of age in humans. Plasma total cholesterol, triglyceride, and phospholipid
levels decreased with aging by about 45%. These reductions were mainly dependent
on a decrease in the LDL fraction. In the liver microsomal fraction, although
there were no age-related changes in the cholesterol concentration and
cholesterol 7alpha-hydroxylase (C7H) activity, 3-hydroxy-3-methylglutaryl
coenzyme A (HMG-CoA) reductase activity increased and acyl-coenzyme A:cholesterol
acyltransferase (ACAT) activity decreased with aging. The lipolytic activity
varied with aging. The secretion rate of very-low-density lipoprotein (VLDL)
cholesterol as determined by injection of Triton WR-1339 decreased significantly
with aging, while the catabolic rate of VLDL cholesterol was about 2-fold higher
in the oldest group versus the young groups. From these results, we conclude that
the age-associated decrease in plasma cholesterol in WHHL rabbits is related not
only to a decrease in the secretion rate of VLDL cholesterol but also to an
increase in the catabolic rate.
PMID- 10778886
TI - Update on the use of auricular cartilage in laryngotracheal reconstruction.
AB - The pediatric otolaryngologist is often called upon to aid in the diagnosis and
management of subglottic stenosis. This report contains an update of our
experience using auricular cartilage in laryngotracheal reconstruction. A
retrospective review of the medical records at St Louis Children's Hospital
identified 43 children with subglottic stenosis. Thirty-one children were treated
by use of auricular cartilage with a success rate of 84%, and an overall 94%
success rate after revision surgery. Eight children in whom an anterior cricoid
split initially failed were secondarily treated with auricular cartilage with a
success rate of 75%. Two children initially treated with costochondral cartilage
underwent multiple reconstructive procedures with either auricular cartilage or
costochondral cartilage with an overall success rate of 50%. The remaining 2
children had long-segment tracheal stenosis and underwent repair with auricular
cartilage with a 50% success rate. We find that auricular cartilage grafts are
highly effective when used in a primary single-stage procedure in children with
grade I or II stenosis. We have had limited success with auricular cartilage in
patients with grade III stenosis and are reluctant to use it in grade IV
stenosis, long-segment tracheal stenosis, staged reconstruction, or revision of
an auricular or costal cartilage graft laryngotracheal reconstruction.
PMID- 10778887
TI - Effect on families and caregivers of caring for a child with laryngomalacia.
AB - We used a retrospective chart review and telephone interviews using a standard
format to 1) measure the outcome and psychosocial costs of caring for a child
with upper airway obstruction due to laryngomalacia and 2) develop an
epidemiologic instrument that measures the impact on the lives of families who
have a child with laryngomalacia. Forty-four patients had laryngomalacia
documented by endoscopy between 1993 and 1997. Complete follow-up information
through 1998 was available on 26 patients. Of the 44 patients, 37 were managed
expectantly and 7 (16%) required surgical intervention. Polysomnograms were
obtained on 11 before neonatal discharge. Twelve patients wore an apnea monitor
for at least 1 month. The quality of life analysis found that the majority of
caregivers were not substantially affected by caring for the stridorous child.
Loss of sleep and heightened anxiety were commonly reported by these caregivers.
Younger parents or parents with fewer than 3 other children were more affected by
caring for a child with laryngomalacia. There was no substantial loss of
workdays, increase in doctor visits, or difficulty in obtaining day care. Caring
for a child with laryngomalacia results in minor disruption of a family's
lifestyle.
PMID- 10778888
TI - Chemodenervation of the rat hemilarynx with phenol.
AB - In this study, the injection of phenol into the true vocal fold was evaluated on
a rat model as a possible treatment for adductor spasmodic dysphonia. A 10%
phenol solution was injected into the right true vocal fold. Quantitative
measurement of vocal fold adductory force showed reduction to 35% of the
preinjection value 3 months after injection (p < .05). Qualitative evaluation by
videolaryngoscopy demonstrated maintenance of the normal vocal fold range of
motion. Histologic studies showed a transient inflammatory infiltrate and
myolysis, while the vocal fold mucosa and the cricoarytenoid joints remained
undamaged. Further investigation into the potential use of phenol for treating
spasmodic dysphonia is warranted.
PMID- 10778889
TI - Arytenoid adduction: controlling vertical position.
AB - In flaccid laryngeal paralysis, the vocal process (VP) is displaced laterally and
superiorly. The arytenoid adduction procedure (AA) moves the VP medially and
caudally, closing the glottic gap. However, clinical evidence suggests that the
VP is more caudal after AA than in physiological phonation. The neurally intact
arytenoid is supported by tonic and phonatory activity of the posterior
cricoarytenoid muscle (PCA). We hypothesize that a posterior anchoring suture
could replace PCA support, achieving a more natural VP location. Cadaver larynges
were scanned with computed tomography at rest and after AA, alone or in
combination with a second arytenoid suture anchored to either the posterior
midline cricoid (PC) or the inferior thyroid cornu (IC). Each posterior suture
reduced caudal displacement of the VP during AA, but the glottic gap was wider
with the PC suture. In 3 patients undergoing AA for laryngeal paralysis, the IC
suture improved arytenoid posture and voice quality.
PMID- 10778890
TI - Laryngeal synkinesis revisited.
AB - First described in 1982, laryngeal synkinesis continues to play an important
diagnostic and therapeutic role following recurrent laryngeal nerve (RLN) injury.
Vocal fold motion impairment (formerly called "vocal cord paralysis"),
hyperadducted and hyperabducted vocal folds, and certain laryngeal spasmodic and
tremor disorders are often best explained by synkinesis. A closer look at these
mechanisms confirms that following RLN injury, immobile vocal folds may be nearly
normally functional (favorable), or spastic, hyperadducted, or hyperabducted
(unfavorable). This has resulted in a functional classification of laryngeal
synkinesis as follows: type I laryngeal synkinesis, with satisfactory voice and
airway (vocal fold poorly mobile, or immobile); type II synkinesis, with
spasmodic vocal folds and an unsatisfactory voice and/or airway; type III
synkinesis, with hyperadducted vocal folds and airway compromise; and type IV
synkinesis, with hyperabducted vocal folds, poor voice, and possible aspiration.
This classification facilitates the understanding of laryngeal pathophysiology
following RLN injuries and promotes a more scientific basis for management.
PMID- 10778891
TI - Surgical planning of the treatment of cholesteatoma and postoperative follow-up.
AB - There is no single surgical treatment of choice for aural cholesteatoma. The
extent of the cholesteatoma, the amount of preoperative destruction, and the size
of the mastoid pneumatization should guide the surgeon in choosing the type of
operation for a particular ear--which may range from a simple extraction of the
cholesteatoma (delivery) all the way to a radical mastoidectomy. It is the
clinical acumen that will determine the type of surgery for a given
cholesteatomatous ear, algorithms being of little use in the complex situation of
a pathological condition with infinite variables. However, even when the most
suitable surgical modality is chosen by the best of surgeons, the operated ear
will still be left with the innate cause of the cholesteatoma, namely, its
physiopathologic background and its tendency to develop a negative gas balance in
the middle ear. Because of this tendency to redevelop negative middle ear
pressure, insertion and reinsertion of ventilation tubes are often necessary to
prevent recurrent retractions and maintain aeration of the middle ear in
posterior tympanotomies and modified radical mastoidectomies. Further, when the
mastoid bowl is marsupialized, as in radical and modified radical
mastoidectomies, the mastoid bowl is often not self-cleansing, thus periodically
requiring the help of the otologist to keep it clean and dry. My study consisted
of a long-term follow-up of 368 cholesteatomatous ears, which were operated on
according to 6 different surgical modalities, ie, 112 radical mastoidectomies, 88
modified radicals, 72 posterior tympanotomies, 52 atticotomies, 36 deliveries,
and 8 obliterations. Of the 368 ears, 11% did not require any postoperative
toilet, whereas 89% required revisiting the surgeon periodically on an average of
every 5 months, for cleansing of the mastoid cavity or securing the aeration of
the middle ear by reinserting a ventilation tube.
PMID- 10778892
TI - Migraine and benign positional vertigo.
AB - Because inner ear symptoms are common in patients with migraine, we questioned
whether benign positional vertigo (BPV) is more common in patients with migraine
than in the general population. We reviewed the records of 247 patients seen in
our neurotology clinic over the past 5 years with a confirmed diagnosis of BPV.
Each patient had the typical history of BPV, and in each case the characteristic
torsional vertical positioning nystagmus was identified. All were interviewed
regarding migraine symptoms by means of standard International Headache Society
criteria. Migraine was 3 times more common in patients with BPV of unknown cause
than in those with BPV secondary to trauma or surgical procedures. Most patients
were cured with the particle repositioning maneuver, regardless of the cause.
Presumably, patients with migraine suffer recurrent damage to the inner ear (due
to vasospasm or some other mechanism) that predisposes them to recurrent bouts of
BPV.
PMID- 10778893
TI - Correlation of pure tone audiogram results and hearing benefit of tympanoplasty
for chronic suppurative otitis media.
AB - The aim of this study was to evaluate the correlation between pure tone audiogram
results and the subjective sensation of hearing benefit of patients who had
tympanoplasty for chronic suppurative otitis media. This is a prospective study
of 115 patients who had tympanoplasty between 1992 and 1994. The outcome,
including a pure tone audiogram and the subjective sensation of hearing benefit,
was evaluated at 1 year after operation. There were 63 (55%) patients with
subjective hearing benefit after the tympanoplasty. The subjective sensation of
hearing benefit correlated with the magnitude of the air conduction (AC)
threshold reduction, and increased from 39% for an AC reduction of less than or
equal to 10 dB to 100% for an AC reduction of more than 30 dB. The effect of the
interaural AC threshold difference on the subjective sensation of hearing was not
significant; improvement was felt by 92% of patients when the operated ear became
the better hearing ear, and by 73% of patients when the operated ear remained the
worse hearing ear. There was considerable discrepancy between the subjective
hearing benefit and the pure tone audiogram results. A combination of parameters,
including the air-bone gap, the AC threshold, and the subjective hearing change,
is recommended in reporting the results of tympanoplasty.
PMID- 10778894
TI - Endolaryngeal microsurgery at the anterior glottal commissure: controversies and
observations.
AB - There are a number of tenets regarding endolaryngeal microsurgical management of
disease that involves and/or encroaches upon the anterior glottal commissure
(AGC). They include avoidance of 1) bilateral epithelial incisions near the AGC,
2) removal of papillomatosis in the AGC, and 3) resection of bilateral keratosis
with atypia or carcinoma at the AGC. During the last 6 years, 115 patients
underwent microsurgical management of disease at the AGC: carcinoma in 20 (T1 in
15 and T2 in 5), keratosis in 41, papillomatosis in 20, and polypoid corditis
(Reinke's edema) in 34. No patients with polypoid corditis developed a synechia
or web. All cancers were successfully resected en bloc; 1 of the 20 patients
developed a microscopic local failure that was successfully re-resected
endoscopically. Eleven of the 20 cancers required excision of part of the
supraglottis to establish adequate exposure for the glottic cancer resection.
Eight of 15 patients with bilateral keratosis underwent staged resections.
Fourteen of 15 patients with bilateral papillomatosis required staged resections.
Twelve of the total 115 patients presented with a web secondary to prior
microsurgery, and 3 developed a new, clinically insignificant web. The
complications of management of disease in or near the AGC described by other
authors were not noted in this series. This success was primarily the result of
improved exposure in the AGC, which was achieved by use of larger and better
designed laryngoscopes and by resection of supraglottic tissue as necessary.
Positioning these prototype laryngoscopes was facilitated by the use of elevated
vector suspension and external counterpressure.
PMID- 10778895
TI - Montgomery Thyroplasty Implant for vocal fold immobility: phonatory outcomes.
AB - Forty-three patients with a diagnosis of unilateral vocal fold immobility
underwent thyroplasty type I with the Montgomery Thyroplasty Implant System.
Preoperative and postoperative evaluations were completed by means of
videostroboscopic, acoustic, and aerodynamic measures. Clinicians' perceptions of
vocal quality and patients' satisfaction with the surgery and vocal quality were
determined. Improvements after surgery were observed for glottal closure, vocal
fold amplitude, mucosal wave activity, average intensity, maximum intensity
range, maximum phonation time, glottal airflow, average sound pressure, and
subglottal pressure. Average postsurgical fundamental frequency values fell
within normal limits and did not display significant changes relative to
presurgical values. The clinicians' perceptual evaluations indicated an
improvement in voice quality for most patients. A majority of patients expressed
satisfaction with the surgery and resulting voice quality. The results of the
present study, in combination with the surgical advantages that have been
described for the Montgomery Thyroplasty Implant System, support the view that
this approach offers an attractive alternative for treating unilateral vocal fold
immobility.
PMID- 10778896
TI - Patterns of chromosomal aberrations in metastasizing and nonmetastasizing
squamous cell carcinomas of the oropharynx and hypopharynx.
AB - Although several cytogenetic events of the tumor progression cascade have been
identified in the past, the specific types of chromosomal alterations that lead
to the development of lymph node metastases are still unknown. Operative
specimens of 20 patients (10 patients with metastasizing tumors, 10 patients with
nonmetastasizing tumors) with squamous cell carcinomas of the oropharynx and
hypopharynx, along with the corresponding lymph node metastases, were
investigated by quantitative DNA measurements and comparative genomic
hybridization (CGH). Nonmetastasizing tumors (N0) displayed overrepresentations
on chromosomes 10q (8 cases); 5p (7 cases); 3q and 20q (6 cases each); 8q (5
cases); 1p and 21q (4 cases each); 7p and 20p (3 cases each); and 2p, 15q, and
19q (2 cases each). Loss of chromosomal material was found on 5q, 9p, and 14q (2
cases each). Metastasizing tumors (N+) demonstrated overrepresentations on
chromosomes 5p, 15q, and 22q (6 cases each); 3q and 11q13 (5 cases each); 20p and
21q (4 cases each); and 10q (3 cases). In 2 cases, an overrepresentation of the
chromosomal arm 3q was accompanied by a loss of chromosomal arm 3p. Less frequent
overrepresentations were observed on chromosomes 1q and 17q. Deletions were found
on chromosomes 18q (3 cases), 3p, 4q, 5q, and 19p (2 cases each); and sporadic
deletions occurred on 2q, 6q, 8p, 9p, 10p, 13q, 14q, 15q, and 16q. Whereas
overrepresentations on chromosomes 1p and 7p occurred exclusively in N0 tumors,
overrepresentations on chromosomes 1q, 11q, and 22q, along with deletions on 18q,
were only observed in N+ tumors. Quantitative DNA measurements revealed a
significantly higher percentage of aneuploid cells and a higher degree of DNA
entropy in the N+ tumors. Chromosomal overrepresentations on chromosomes 1q, 8q,
11q, 18q, and 19q occurred more frequently in the metastases than in the
corresponding primary tumors. Pairwise analysis of chromosomal alterations in the
primary tumors and associated lymph node metastases revealed a genetic
relationship, although a greater number of chromosomes on average were affected
in the lymph node metastases. Quantitative DNA measurements demonstrated greater
aneuploid values in the metastases. Recurring patterns of chromosomal alterations
in N0 and N+ tumors were demonstrated in this study. In general, metastasizing
tumors are characterized by overrepresentations on chromosomes 11q13 and 22q, and
deletions on 18q. These aberrations suggest an elevation along the tumor
progression cascade.
PMID- 10778897
TI - Pediatric lymphangiomas of the head and neck.
AB - To better define the cause, presentation, diagnosis, and staging of
lymphangiomas, we reviewed all cases of lymphangiomas of the head and neck region
in children seen at our institution between 1986 and 1996. Sixty-seven children
were identified (31 male and 36 female). Age at presentation ranged from birth to
18 years. All but 8 patients presented with an obvious mass, and 5 required
tracheotomy because of airway obstruction. The most common location was the
submandibular region (37%), followed by the parotid gland (31%). Treatment ranged
from observation to extensive and multiple resections. Thirty-one patients
underwent only 1 resection, and 2 patients received interferon as part of their
treatment. Lesions involving the lip, hypopharynx and/or larynx, the tongue, and
the floor of the mouth had high rates of recurrent or persistent disease. We
review our experience with these difficult lesions and propose a staging system
based on functional deficit, cosmetic changes, sites of involvement, and age at
diagnosis.
PMID- 10778898
TI - Slow-release 5-fluorouracil and triamcinolone reduces subglottic stenosis in a
rabbit model.
AB - A previous pilot study suggested that a sustained-release conjugate that provided
a slow release of 5-fluorouracil and triamcinolone acetonide injected into the
tracheal and paratracheal tissues of rabbits at the time of subglottic surgery
reduced the formation of subglottic stenosis. Our study was undertaken to confirm
the effect. Ten milligrams of the compound suspended in hyaluronic acid was
injected at the time of injury via a laryngofissure approach. The results showed
that the control group had a mean stenosis of 52%, whereas the treated group had
a mean stenosis of 32%. There was a significant difference between the treated
and untreated groups (p = .003). It is hoped that this co-drug ultimately can be
used in humans to reduce stenosis formation after laryngotracheal surgery and in
other forms of otorhinolaryngological surgery.
PMID- 10778899
TI - Endoscopic revision surgery for recurrent epiphora occurring after external
dacryocystorhinostomy.
AB - Recurrent epiphora after external dacryocystorhinostomy (DCR) can be a
frustrating experience for both the patient and the physician. We present the
results of a retrospective study of 18 patients with epiphora recurring after
external DCR who were operated upon to recreate lacrimal drainage through an
endoscopic endonasal approach. The procedure was successful in 83.3% of cases,
with no major complications. The results are comparable to those of an external
approach, but the cosmetic advantages are clear. It is a 1-stage procedure that
permits correction of associated intranasal disease that may be a causative
factor in the recurrence of lacrimal obstruction. The endoscopic endonasal
approach is a relatively safe and reliable option in the management of recurrent
epiphora.
PMID- 10778900
TI - Fourth branchial cyst presenting with neonatal respiratory distress.
AB - Fourth branchial cysts are quite rare. A neonate with a left lateral neck mass
and respiratory distress was found to have a fourth branchial cyst, which was
diagnosed with computed tomography and endoscopy. The characteristic computed
tomography findings included an air-containing neck cyst, which was located at
the anteromedial site of the common carotid artery with mediastinal extension.
Endoscopic examination revealed an internal opening at the apex of the pyriform
sinus, communicating with the cyst. Total excision of the cyst was performed, and
the specimen, which showed ciliated columnar epithelium with a subepithelial
lymphoid infiltrate, thyroid follicles, and thymic tissue, histologically
confirmed the diagnosis.
PMID- 10778902
TI - Chordoma of the cervical spine.
PMID- 10778901
TI - Irreversible sensorineural hearing loss as a result of azithromycin ototoxicity.
A case report.
AB - Azithromycin, an azalide antibiotic, rarely causes ototoxicity. According to the
few reports in existence, azithromycin-induced ototoxicity occurred following
prolonged high-dose therapy in patients with acquired immunodeficiency syndrome
and resulted in a reversible sensorineural hearing loss. We present a case of
irreversible sensorineural hearing loss due to azithromycin ototoxicity in an
otherwise healthy woman following low-dose exposure to azithromycin.
PMID- 10778903
TI - The role of the clinical toxicologist in environmental toxicology.
PMID- 10778904
TI - Pyrethroid insecticides: poisoning syndromes, synergies, and therapy.
AB - BACKGROUND: Pyrethroid insecticides are widely used, but there have been
relatively few reports of systemic poisoning. These reports have, however, shown
that pharmacotherapy is difficult and that the duration of poisoning can be
unexpectedly long. Pyrethroids are ion channel toxins prolonging neuronal
excitation, but are not directly cytotoxic. Two basic poisoning syndromes are
seen. Type I pyrethroids produce reflex hyperexcitability and fine tremor. Type
II pyrethroids produce salivation, hyperexcitability, choreoathetosis, and
seizures. Both produce potent sympathetic activation. Local effects are also
seen: skin contamination producing paresthesia and ingestion producing
gastrointestinal irritation. The slow absorption of pyrethroids across the skin
usually prevents systemic poisoning, although a significant reservoir of
pyrethroid may remain bound to the epidermis. Carboxyesterase inhibitors can
enhance pyrethroid toxicity in high-dose experimental studies. Hence, the
unauthorized pyrethroid/organophosphate mixtures marketed in some developing
countries may precipitate human poisoning. Pyrethroid paresthesia can be treated
by decontamination of the skin, but systemic poisoning is difficult to control
with anticonvulsants. Pentobarbitone, however, is surprisingly effective as
therapy against systemic type II pyrethroid poisoning in rats, probably due to
its dual action as a chloride channel agonist and a membrane stabilizer.
PMID- 10778905
TI - Pyrethroid-induced paresthesia--a central or local toxic effect?
AB - BACKGROUND: Pyrethroid-induced paresthesia is frequently seen after dermal
exposure to pyrethroids. Affected individuals experience a sensation of burning,
tingling, itching, or numbness, most commonly in the face. This occurs 1-2 hours
after the beginning of exposure and resolves spontaneously. MECHANISMS:
Paresthesia occurs as a result of a direct effect on intracutaneous nerve endings
at very low pyrethroid doses. It is related to potency of the pyrethroid with
pyrethroids without an alpha-cyano group generally showing the weakest effect.
CONCLUSION: Doses sufficient to cause paresthesia are far lower than those
causing central or systemic toxicity. Paresthesia is therefore considered to be a
localized nuisance effect. The best advice to affected individuals is to prevent
paresthesia from occurring through appropriate hygiene measures and personal
protection.
PMID- 10778906
TI - Management of pyrethroid exposure.
AB - OVERVIEW: Severe pyrethroid insecticide poisoning is uncommon in the developed
world, but more common in developing countries because of its wide use in
agriculture. This short review proposes a management strategy for pyrethroid
poisoning based on the present literature. It also mentions an experimental
approach, which will require further study in animals and may have eventual
relevance for man.
PMID- 10778908
TI - Mechanisms of toxicity, clinical features, and management of diquat poisoning: a
review.
AB - USES: Diquat (1,1'-ethylene-2,2'-bipyridilium) is a nonselective bipyridyl
herbicide, related structurally to paraquat, which is used both as a contact
herbicide and a preharvest desiccant. In comparison to paraquat, diquat is used
much less widely in agriculture. MECHANISMS OF TOXICITY: Diquat is a potent redox
cycler and is readily converted to a free radical which, in reaction with
molecular oxygen, generates superoxide anions and subsequently other redox
products. These products can induce lipid peroxidation in cell membranes, and
potentially cause cell death. FEATURES: Over the period 1968-1999, only 30 cases
of diquat poisoning were reported in detail in the literature, of which 13 (43%)
were fatal. Local and systemic effects have been reported following diquat
exposure, with systemic features being invariably associated with ingestion. In
severe and usually fatal cases, gastrointestinal mucosal ulceration, paralytic
ileus, hypovolemic shock, acute renal failure, and coma have been reported.
MANAGEMENT: After rapid confirmation of the diagnosis using a qualitative urine
test, gut decontamination may be considered in patients who present within 1 hour
of a life-threatening ingestion (>6 g). Supportive measures including fluid and
electrolyte replacement should then be employed. Although hemofiltration and
hemodialysis are of proven value if renal failure supervenes, there is no
clinical evidence that hemodialysis or hemoperfusion removes toxicologically
significant amounts of diquat, thereby reducing the risk of organ failure and
preventing a fatal outcome in severe cases.
PMID- 10778907
TI - Mechanisms of toxicity, clinical features, and management of acute chlorophenoxy
herbicide poisoning: a review.
AB - INTRODUCTION: Chlorophenoxy herbicides are used widely for the control of broad
leaved weeds. They exhibit a variety of mechanisms of toxicity including dose
dependent cell membrane damage, uncoupling of oxidative phosphorylation, and
disruption of acetylcoenzyme A metabolism. Between January 1962 and January 1999,
66 cases of chlorophenoxy herbicide poisoning following ingestion were reported
in the literature. FEATURES FOLLOWING INGESTION: Adjuvants in the formulations
may have contributed to some of the features observed. Vomiting, abdominal pain,
diarrhea, and, occasionally, gastrointestinal hemorrhage were early effects. When
present, hypotension was predominantly due to intravascular volume loss, although
vasodilation and direct myocardial toxicity may have contributed in some cases.
Neurotoxic features included coma, hypertonia, hyperreflexia, ataxia, nystagmus,
miosis, hallucinations, convulsions, fasciculation, and paralysis.
Hypoventilation occurred not infrequently, usually in association with central
nervous system depression, but respiratory muscle weakness was a factor in the
development of respiratory failure in some patients. Myopathic symptoms including
limb muscle weakness, loss of tendon reflexes, and myotonia were observed and
increased creatine kinase activity was noted in some cases. Other clinical
features reported included metabolic acidosis, rhabdomyolysis, renal failure,
increased aminotransferase activities, pyrexia, and hyperventilation. Twenty-two
of 66 patients died. FEATURES FOLLOWING DERMAL AND INHALATIONAL EXPOSURE:
Substantial dermal or inhalational 2,4-dichlorophenoxyacetic acid exposure has
occasionally led to systemic features but no such reports have been published in
the last 20 years and no fatalities have been reported at any time. Substantial
dermal exposure has been reported to cause mild gastrointestinal irritation after
a latent period followed by progressive mixed sensory-motor peripheral
neuropathy. Mild, transient gastrointestinal and peripheral neuromuscular
symptoms have also occurred after occupational inhalation exposure, with or
without dermal exposure. MANAGEMENT: In addition to supportive care, alkaline
diuresis to enhance herbicide elimination should be considered in all seriously
poisoned patients. Limited clinical data suggest that hemodialysis produces
similar herbicide clearance to alkaline diuresis without the need for urine pH
manipulation and the administration of substantial amounts of intravenous fluid
in an already compromised patient. CONCLUSIONS: While chlorophenoxy herbicide
poisoning is uncommon, ingestion of a chlorophenoxy herbicide can result in
serious and sometimes fatal sequelae. In severe cases of poisoning, alkaline
diuresis or hemodialysis to increase herbicide elimination should be considered.
PMID- 10778909
TI - Herbicide formulations.
AB - BACKGROUND: Herbicides comprise nearly half of the 5 billion pounds of pesticide
active ingredients used worldwide annually. The active ingredient must be
formulated with other ingredients to allow mixing, dilution, application, and
stability. Liquid commercial formulations for spray foliar application include
water-soluble liquids, emulsifiable concentrates, suspension concentrates or
"flowables," and gels. Dry formulations that are mixed with water for spray
application include wettable powders and water-dispersible granules. Granules are
broadcast directly out of the bag. The carrier in liquid formulations is either
water or an organic solvent or oil. The general chemical class of the carrier may
be deduced based on the solubility characteristics of the active ingredient.
Cosolvents may be necessary to optimize solubility and stability. Surfactants are
nearly universally present in herbicide formulations or added prior to
application. They aid uniform spreading of the spray droplet on the leaf and
penetration of its waxy cuticle by the active ingredient. In solvent-based
formulations, surfactants permit a stable oil-in-water emulsion to form when
diluted with water for actual use. New surfactant systems are currently of
intense competitive importance. Other formulation ingredients include pH
adjusters, buffers, milling aids, antifoaming agents, acid scavengers, dyes,
suspending agents, preservatives, dispersants, emulsifiers, densifiers,
antifreeze, and crystal promoters. In highly regulated environments, the other
formulation components in pesticides are receiving scrutiny. In the US, the EPA's
strategy has been to categorize currently used formulation ingredients into 4
lists based on their toxicology profiles. The ultimate outcome is to have all
inert ingredients on List 4, Minimal Risk. List 4 ingredients are generally
regarded as safe or have current use patterns that do not pose an unreasonable
risk of adverse effect to public health or the environment.
PMID- 10778910
TI - Chemical contamination of private drinking water supplies in the West Midlands,
United Kingdom.
AB - INTRODUCTION: In the United Kingdom, private drinking water supplies are subject
to much less stringent sampling and testing regimes than are public supplies.
Information regarding the quality of private drinking water supplies is disparate
and poorly defined. The aim of this study was to collate the data for chemical
contamination of private drinking water supplies in the West Midlands, a region
of Central England with a population of 5.3 million. METHODS: The most recent
year's data on the number of private supplies, the number of supplies sampled,
and the number and type of failures for chemical parameters were obtained from
District and Local Authorities in the West Midlands Region. RESULTS: Data covered
12-month periods during 1995-1996. Of the 6013 private supplies identified,
samples from 1297 had been tested for chemical parameters during the period of
the study. A total of 420 individual failures for chemical parameters were
reported in 386 water supplies. The majority of breaches of United Kingdom and
European Union standards were due to increased concentrations of nitrates (270),
magnesium (21), manganese (17), and iron (15). Increased turbidity was present in
27 cases. Only 6 samples breached the standard for lead and 6 for pesticides.
CONCLUSIONS: Over a quarter of the supplies tested during the period of the study
were in breach of United Kingdom and European Union legislation. Of the reported
failures, the high concentrations of nitrate and nitrite, lead, copper, and
sulfate are of concern to health and remedial action is warranted. Regular
sampling of private drinking water supplies remains necessary to prevent risk to
health from a wide variety of toxic contaminants.
PMID- 10778911
TI - Pesticides in drinking water: what should be the standard?
PMID- 10778912
TI - A case of fatal diquat poisoning: toxicokinetic data and autopsy findings.
AB - CASE REPORT: A 37-year-old man ingested in a suicide attempt 300 mL of a diquat
solution (equivalent to 60 g diquat ion). The initial diquat serum concentration
was 64 microg/mL 4 hours after poisoning. The clinical course was characterized
by a progressive anuria and by neurological disorders (coma and seizures). The
patient died 26 hours after poisoning from refractory cardiocirculatory collapse.
Extracorporeal techniques removed 1.09 g of diquat which could be considered as
significant in regard to the total amount that was likely absorbed, but they did
not influence the clinical outcome. There was marked renal tubular damage at
autopsy and the highest diquat tissue concentration was found in the kidneys.
PMID- 10778913
TI - A case of transient diabetes insipidus associated with poisoning by a herbicide
containing glufosinate.
AB - BACKGROUND: The herbicide BASTA (AgrEvo, Germany), containing glufosinate
ammonium (20%) and an anionic surfactant, polyoxyethylene alkylether sulfate
(33%), is widely used. In acute oral BASTA poisoning, patients develop a variety
of clinical signs, including disturbed consciousness, convulsions, and apnea.
These effects are suspected to be due to the effects of glufosinate on the
central nervous system. CASE REPORT: A 60-year-old man ingested 500 mL of BASTA
herbicide in a suicide attempt. He developed not only unconsciousness,
respiratory distress, and convulsions but also an increase in urine output (7885
mL/d), elevated serum sodium (167 mEq/L), elevated plasma osmolality (332
mOsm/kg), and a decrease in both urine osmolality (200 mOsm/kg) and urine
specific gravity (1.003), which suggested the development of diabetes insipidus.
The plasma level of antidiuretic hormone remained within the normal range (1.3
pg/mL), despite high plasma osmolality. The administration of desmopressin was
successful in normalizing urine volume, specific gravity, and osmolality. Serum
sodium corrected gradually within 48 hours. The possible mechanisms causing the
diabetes insipidus are discussed.
PMID- 10778914
TI - Human mast cell subsets--distinct functions in inflammation?
AB - That mast cells participate in inflammatory reactions is beyond argument. A major
question posed by mast cell biologists is whether specific functions in
inflammation are subserved by different subsets of the mast cell population. We
have investigated the two major subsets of human mast cells (MC(T) and MC(TC)),
in the chronic inflammatory processes associated with rheumatoid arthritis (RA).
Whereas normal synovium contains mainly MC(TC) mast cells, the MC(T) subset is
selectively expanded in early RA, in numbers that correlate with synoviocyte
hyperplasia and T-lymphocyte infiltration. In contrast, in RA of long duration,
MC(TC) mast cells predominate in numbers that correlate with clinical indices of
rapidity of disease progression. We suggest that MC(T) mast cells participate in
active inflammatory events, whereas MC(TC) mast cells may be more relevant in
repair or damage to connective tissues.
PMID- 10778915
TI - Induced sputum of patients with chronic obstructive pulmonary disease (COPD)
contains adhesion-promoting, therapy-sensitive factors.
AB - OBJECTIVE: The aim of this study was to investigate whether sputum of COPD
patients before and after treatment with inhaled corticosteroids (IHC) or N
acetylcysteine (NAC) exerts any effect on the adhesion of isolated
polymorphonuclear cells (PMNs) to cultured endothelial cells. METHODS: A human
endothelial cell line was grown to confluence before use in adhesion experiments.
PMNs were obtained from normal, non-smoking volunteers and preincubated (30 min,
37 degrees C) with diluted sputum sol obtained from COPD patients before the
cells were put on the endothelial cells. RESULTS: Basal adhesion of unstimulated
PMNs after 30 min at 37 degrees C in 5% CO2 was 15.9+/-1.1% (mean +/- SEM, n =
9). A significant enhancement of the adhesion to 33.0+/-1.4% (n = 11, P<0.0001)
was observed with sputum obtained from COPD patients before treatment with IHC,
and 34.6+/-1.5% (n = 10, P<0.0001) before treatment with NAC. Administration of
IHC for 8 weeks resulted in an adhesion of 27.7+/-2.4%, which is an inhibition of
31% (n = 11, P<0.05). However, treatment for 8 weeks with NAC showed no change in
the adhesion of stimulated PMNs. Long-term treatment with NAC showed a gradual
decrease of adhesion (n = 9, P<0.05), whereas long-term treatment with IHC lead
to an increase in adhesion (n = 10, P<0.02). CONCLUSIONS: These results indicate
that factors locally produced in the airways of COPD patients may promote
adhesion of neutrophils to endothelium. They further suggest that glucocorticoids
may only have a short-term transient effect on adhesion, whereas NAC showed
effects on the adhesion after administration for longer periods.
PMID- 10778916
TI - Effects of pentoxifylline and nabumetone on the serum levels of IL-1beta and
TNFalpha in rats with adjuvant arthritis.
AB - OBJECTIVE AND DESIGN: This study examined whether serum levels of cytokines, IL
1beta and TNFalpha were elevated in rats with adjuvant arthritis in relation to
disease progression, and if so, to verify the treatment effects of nabumetone (20
mg/kg, p. o.), a COX-2 inhibitor and pentoxifylline (20 mg/kg, p.o.), a type-4
phosphodiesterase (PDE4) inhibitor, alone or in combination. MATERIALS AND
METHODS: Female Wistar rats were used. Freund's complete adjuvant (FCA) was used
to induce arthritis. The increment in contralateral hind paw volume (the
secondary lesion) was determined by plethysmometry and the serum cytokines were
measured by ELISA. RESULTS: In control rats, the serum IL-1beta and TNFalpha
levels were greatly elevated on the very first day i.e. 5 h after FCA, and
thereupon a progressive decrease in IL-1beta but not TNFalpha was observed until
day 30. The secondary arthritic lesion began to increase on day 14 (125+/-26
microl), and attained its peak (330+/-79 microl) on day 21 post-adjuvant
injection. The peak arthritic lesion was significantly (p<0.001) less in rats
that received nabumetone and pentoxifylline, alone or in combination (20+/-8,
41+/-15 and 65+/-10 microL, respectively). When serum cytokine levels were
analysed on day 20 postadjuvant injection, rats treated with pentoxifylline or in
association with nabumetone, but not nabumetone alone showed significantly
lowered levels of serum TNFalpha. Unlike TNFalpha, serum IL-1beta did not vary
significantly. CONCLUSIONS: The drugs nabumetone and pentoxifylline although
appearing to produce differential effects on serum cytokine levels, seem to be
equally efficacious in attentuating the progression of FCA-induced arthritis.
Serum cytokine levels may not accurately reflect the treatment efficacy.
PMID- 10778918
TI - Alterations in protein kinase C isoforms in experimentally-induced colitis in the
rat.
AB - BACKGROUND: Although protein kinase C (PKC) isoenzymes have been implicated as
mediators for multiple physiological processes, PKC also mediates cellular and
intestinal mucosal injury. We have investigated the expression of the isoenzymes,
PKCalpha, PKCdelta, PKCepsilon and PKCzeta in colonic mucosal tissue from TNBS
treated and HLA-B27 spontaneous colitis animals. METHODS: Colonic mucosal samples
were taken at various times (2 h-14 d) after instillation of TNBS (75 mg/kg in
50% ethanol) or from HLA-B27 rats at 16-18 weeks of age. Tissues were homogenized
and separated into membrane and cytosolic fractions by centrifugation. PKC
activity was measured radioenzymatically. PKC protein for isoforms alpha, delta,
epsilon and delta was assessed by Western blot while corresponding mRNA was
analyzed by RT-PCR. RESULTS: PKC activity increased in cytosolic and membrane
fractions by 1d after TNBS and returned to normal by d3. PKCalpha protein was
translocated from cytosol to membrane by 2 h after TNBS followed by down
regulation until d3. Increases in PKCdelta, PKCepsilon and PKCzeta protein
occurred initially in membrane fractions as early as 2 h after TNBS. Increases in
cytosolic protein occurred at later times after induction of colitis. Protein
levels for all isoenzymes remained increased up to 7d after TNBS. RT-PCR revealed
that mRNA for PKCalpha decreased while PKC mRNA increased correspondingly with
their respective protein levels. In HLA-B27 rats, protein levels for all isoforms
were less than was detected in normal colonic tissue. CONCLUSIONS: The early
increase in gene expression and protein levels for PKCalpha and zeta suggest that
these isozymes may play roles in an acute model of colitis induced by TNBS. In
contrast, the increase in PKCdelta and epsilon protein was not associated with
mRNA changes suggesting that these isozymes are not similarly regulated in the
inflamed colonic mucosa. In a chronic model of experimental colonic inflammation
(HLA-B27), all of these isoforms appeared to be down-regulated.
PMID- 10778917
TI - Differential anti-inflammatory effects of immunosuppressive drugs: cyclosporin,
rapamycin and FK-506 on inducible nitric oxide synthase, nitric oxide,
cyclooxygenase-2 and PGE2 production.
AB - OBJECTIVE AND DESIGN: Cyclosporin, FK-506 and rapamycin have similar but distinct
modes of interaction with cyclophilins, calcineurins and transcription factors.
These immunosuppressive drugs have also been shown to inhibit cytotoxic and
inflammatory responses in macrophage. Therefore, we evaluated the mechanism of
action of these drugs on iNOS and COX-2 expression by macrophages, the products
of which (NO and PGE2) have cytotoxic and proinflammatory activities. MATERIALS
AND METHODS: The murine macrophage cell line RAW 264.7 was grown as monolayer
cultures. The effects of pharmacologically relevant concentrations of
cyclosporin, rapamycin and FK-506 were evaluated in the presence and absence of
lipopolysaccharide (LPS) which is a known inducer of iNOS and COX-2. Subsequently
the expression of iNOS and COX-2 were analyzed by Western and Northern analysis.
The production of NO and PGE2 were assayed by Greiss and RIA respectively.
RESULTS: Cyclosporin (1-5 microg/ml) and rapamycin (1.0-10 nM) but not FK-506 (5
10 nM) inhibited both iNOS and COX-2 expression at mRNA level which led to
significant inhibition of NO and PGE2 production. CONCLUSION: These studies
characterize differential mechanistic capacity of the immunophilin-binding
immunosuppressive drugs (comparable to hydrocortisone) to inhibit both iNOS and
COX-2 expression. Inhibition of iNOS and COX-2 mRNA accumulation by cyclosporin
and rapamycin seem to be distinct. These studies also highlight potential anti
inflammatory properties of these drugs in addition to their known
immunosuppressive activity.
PMID- 10778919
TI - Excitatory amino acid release in the locus coeruleus during naloxone-precipitated
morphine withdrawal in adjuvant arthritic rats.
AB - OBJECTIVE AND DESIGN: Excitatory amino acid levels in the locus coeruleus (LC)
and the behavioral signs during naloxone-precipitated withdrawal in arthritic
rats treated with chronic morphine were investigated by in vivo microdialysis.
METHODS: Increases in glutamate (Glu) and aspartate (Asp) were noted after
naloxone (48 nmol/5 microl, LC)-precipitated withdrawal from normal and adjuvant
arthritic rats which had been intracerebroventricularly infused for 3 days with
morphine (26 nmol/l microl/h). RESULTS: The increases in Glu and Asp levels on
morphine withdrawal in normal rats were attenuated following naloxone challenge
in the morphine-dependent arthritic rats. Moreover, behavioral signs during
morphine withdrawal were detected following the naloxone challenge in both the
morphine-dependent normal and adjuvant arthritic rats, but not in the saline
infused controls. CONCLUSIONS: These results show that the attenuation of Glu and
Asp release from the LC in the adjuvant arthritic rats might explain the anti
inflammatory and analgesic effects of mu-opioids in adjuvant arthritic rats.
PMID- 10778920
TI - Inhibitory effects of newly synthesized active center-directed trypsin-like
serine protease inhibitors on the complement system.
AB - OBJECTIVE: To obtain a synthetic anti-complement inhibitor which has stronger
activity than FUT-175 (nafamostat mesilate), as a synthetic ester derivative
containing amidino and guanidino groups. METHODS: We synthesized several modified
compounds of FUT-175. The anti-complement activities were measured using
synthetic substrates and complement-mediated hemolysis in vitro. The anti
complement activity in vivo was evaluated via Forssman systemic shock in guinea
pigs. RESULTS: FUT-175 inhibited C1r and C1s with IC50s of 1.7x10(-6) and 3.2x10(
7) M, respectively. Inhibitory activities were decreased by substitution of the
amidino group with a hydrogen atom (compound 2), but not the guanidino group with
a hydrogen atom (compound 3). Compound 6, in which the benzene ring of compound 3
was substituted with a furan ring, inhibited C1r and the complement-mediated
hemolysis in high-diluted serum with higher potency than FUT-175. The inhibitory
activity of compound 6 in hemolysis was weakened in low diluted serum. Compound 7
had a guanidino group inserted into compound 6; however, Compound 7 strongly
inhibited hemolysis even in low-diluted serum, and suppressed Forssman systemic
shock more potently than both FUT-175 and compound 6. CONCLUSIONS: These data
suggest that the 2-furylcarboxylic acid derivatives have a strong potential for
inhibiting the activities of the complement, and the guanidino group was required
to retain high inhibitory activities in vivo, and compound 7 is a hopeful anti
complement agent.
PMID- 10778921
TI - Simultaneous analysis of shikimate-derived secondary metabolites in Lithospermum
erythrorhizon cell suspension cultures by high-performance liquid chromatography.
AB - A high-performance liquid chromatography (HPLC) analysis system based on a water
acetonitrile gradient program was established for simultaneous quantification of
shikimate-derived secondary metabolites in cultured cells of Lithospermum
erythrorhizon. The cells cultured in pigment production medium (M-9) are capable
of producing five highly hydrophilic compounds such as p-hydroxybenzoic acid-O
glucoside and lithospermic acid B, as well as eleven lipophilic compounds
including echinofuran B and acetylshikonin. In addition to the wide polarities of
those compounds, many of them are unstable under light, dryness, oxygen and
heating. Thus, a new extraction procedure for all these compounds was also
established by use of ultrasonication under ice-water chilling with MeOH as the
solvent. This procedure was applied to the quantitative analyses of these
compounds in cell cultures and hairy root cultures of Lithospermum, and in the
intact plants as well.
PMID- 10778922
TI - Simultaneous determination of hydrocortisone, dexamethasone, indomethacin,
phenylbutazone and oxyphenbutazone in equine serum by high-performance liquid
chromatography.
AB - Ethyl acetate extracts of equine serum, containing 0-5 microg/ml of
hydrocortisone (HYD), dexamethasone (DEX), oxyphenbutazone (OPB), indomethacin
(IND), phenylbutazone (PB) and probenecid as internal standard, were evaporated
with nitrogen, resuspended in methanol and analyzed by HPLC, using a C-18 column
equilibrated with 51:49 acetonitrile-water, 0.1% trifluoroacetic acid, at 1
ml/min. The eluate was monitored at 254 nm. The selectivity (inter-assay
C.V.<4%), sensitivity (limits of quantitation of 0.25 microg/ml for HYD, DEX and
IND, 0.5 microg/ml for PB and 1 microg/ml for OPB, despite the occurrence of
significant degradation of OPB and PB during the analysis) and precision (intra
assay and inter-assay C.V.'s of about 3-6 and 9-15%, respectively) of the method
appeared appropriate for anti-doping control of racehorses.
PMID- 10778923
TI - Enantioselective analysis of metoprolol in plasma using high-performance liquid
chromatographic direct and indirect separations: applications in
pharmacokinetics.
AB - Direct enantioselective separation on chiral stationary phases and indirect
separation based on the formation of diastereomeric derivatives were developed
and compared for the HPLC analysis of R(+) and S(-)-metoprolol in human plasma.
Plasma samples prepared using solid-phase extraction columns or liquid-liquid
extraction were directly analyzed on a Chiralpack AD or on a Chiralcel OD-H
columns, respectively. S-(-)-menthyl choroformate was also used to yield
diastereomeric derivatives resolved on a RP-8 column. The methods were employed
to determine plasma concentrations of metoprolol enantiomers in a pharmacokinetic
study of single dose administration of racemic metoprolol to a healthy Caucasian
volunteer phenotyped as extensive metabolizer of debrisoquine. The correlation
coefficients among enantioselective metoprolol plasma concentrations (5-223
ng/ml) obtained by the three methods were equal or higher than 0.99. The direct
method that employed the chiral column Chiralpak AD may be considered the most
sensitive, although the three methods demonstrated interchangeable use in the
pharmacokinetic investigation.
PMID- 10778924
TI - Determination of mandelic acid enantiomers in urine by gas chromatography and
electron-capture or flame ionisation detection.
AB - A sensitive and stereospecific GC method was developed for the analysis of R- and
S-enantiomers of mandelic acid (MA) in urine, using a chiral CP Chirasil-Dex-CB
column. The enantiomers of MA were derivatised with isopropanol into their
corresponding isopropyl esters and determined either directly with flame
ionisation detection (FID) or after subsequent derivatisation of a hydroxy group
with pentafluoropropionic anhydride with electron-capture detection (ECD). Both
derivatisation steps proceeded with negligible inversion of enantiomers (<1%).
The limit of detection of the FID determination was 8 and 5 mg/l for R-MA and S
MA, respectively and of the ECD determination 1 mg/l for both enantiomers.
Repeatability (within-day precision) and reproducibility (day-to-day precision)
was for both enantiomers below 7.5% for the FID and below 5.8% for the ECD
analysis. The method was applied to urine of volunteers exposed to 105 and 420 mg
styrene/m3 air. In the urine of the exposed volunteers, the S-enantiomer showed
higher excretion compared to that of the R-enantiomer, with marked
interindividual differences in excretion of both enantiomers.
PMID- 10778925
TI - High-performance liquid chromatographic method with fluorescence detection for
the determination of 3-hydroxybenzo[a]pyrene and 3-hydroxybenz[a]anthracene in
the urine of polycyclic aromatic hydrocarbon-exposed workers.
AB - The described high-performance liquid chromatographic method with fluorescence
detection (HPLC-FD) permits the simultaneous determination of 3
hydroxybenzo[a]pyrene and 3-hydroxybenz[a]anthracene as the most important
metabolites of the carcinogenic polycyclic aromatic hydrocarbons (PAHs)
benzo[a]pyrene and benz[a]anthracene in human urine. After enzymatic hydrolysis,
to release the conjugated metabolites, the analytes are separated from the matrix
by means of a liquid-solid extraction step which is followed by a coupled column
HPLC procedure using an enriching precolumn consisting of silica modified with
copper phthalocyanine. This special precolumn selectively adsorbs PAHs with at
least three condensed rings and thus separates them from the urine matrix. The
quantitative analysis was carried out using a switchable fluorescence detector.
The detection limits were 6 ng/l urine (3-hydroxybenzo[a]pyrene) and 8 ng/l urine
(3-hydroxybenz[a]anthracene). The relative standard deviations of the within
series imprecision ranged between 4.0% and 9.0%. The between-day imprecision was
7.7% (3-hydroxybenz[a]anthracene) and 12.9% (3-hydroxybenzo[a]pyrene). The
recovery rates ranged between 102% and 124%. Using this analytical method we
determined PAH metabolites in post shift urine samples from 19 workers engaged in
the production of fire-proof materials. The urinary concentrations ranged from 3
to 198 ng 3-hydroxybenzo[a]pyrene per g creatinine and from 15 to 1871 ng 3
hydroxybenz[a]anthracene per g creatinine.
PMID- 10778926
TI - New and simple procedure for the determination of muramic acid in chemically
complex environments by gas chromatography-ion trap tandem mass spectrometry.
AB - A gas chromatographic-ion trap tandem mass spectrometric method was developed for
the quantification of muramic acid, a marker of bacterial peptidoglycan, in
environmental and clinical specimens. Samples (bacteria, house dust and urine)
were heated in methanolic hydrochloric acid overnight and extracted with hexane
for removal of hydrophobic compounds. The aqueous phase was evaporated and heated
in acetic anhydride and pyridine after which the product, the acetate derivative,
was washed with dilute hydrochloric acid and water. The described method is both
rapid and simple to apply, and produces a stable derivative. It should become
widely used for measuring peptidoglycan in chemically complex environments.
PMID- 10778927
TI - Enantioselective high-performance liquid chromatographic analysis of the 5-HT1A
receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin. Application to a
pharmacokinetic-pharmacodynamic study in rats.
AB - A rapid, sensitive and enantioselective HPLC assay for the simultaneous
determination of the reference 5-HT1A receptor agonists, R-(+)- and S-(-)-8
hydroxy-2-(di-n-propylamino)tetralin (R-8-OH-DPAT and S-8-OH-DPAT, respectively),
in rat blood is presented. A selective extraction procedure was developed using a
preliminary sample clean-up followed by isolation of R- or S-8-OH-DPAT on mixed
mode NARC-2 solid-phase columns. Separation of the enantiomers was performed by
high-performance liquid chromatography using a Chiracel OD-R column. Detection
was obtained using an electrochemical detector set at a voltage of 0.63 V. The
mobile phase consisted of a 50 mM phosphate buffer (pH 5.5)-acetonitrile (80:20,
v/v) mixture. At a flow-rate of 1 ml min(-1), the total run time was
approximately 14 min. The limit of detection for R- and S-8-OH-DPAT was 0.5 ng
ml(-1). In the concentration range between 50 ng ml(-1) and 1000 ng ml(-1) intra-
and inter-day relative standard deviations were less than 12%. The assay was
applied to a pharmacokinetic-pharmacodynamic study in rats in which decrease of
body temperature was used as a measure of 5-HT1A receptor-mediated effect. Values
for clearance, volume of distribution at steady state and terminal elimination
rate constant were 22+/-2 ml min(-1), 1969+/-473 ml and 156+/-34 min for R-8-OH
DPAT and 16+/-1 ml min(-1), 3353+/-347 ml and 334+/-36 min for S-8-OH-DPAT,
respectively. No enantiomeric interconversion was observed in vivo from R-8-OH
DPAT to S-8-OH-DPAT or vice versa.
PMID- 10778928
TI - Concurrent quantification and pharmacokinetic analysis of cefotaxime in rat blood
and brain by microdialysis and microbore liquid chromatography.
AB - A simple but effective coupling of microdialysis and microbore liquid
chromatograph with UV detection technique was applied to the simultaneous
studying of the pharmacokinetics of cefotaxime in both the peripheral compartment
and central nervous system. The mobile phase consisted of methanol-100 mM
monosodium phosphoric acid (25:75, v/v, pH 5.5) pumped through a C18 microbore
column at a flow-rate of 0.05 ml/min. Detection of cefotaxime was set at a UV
wavelength of 254 nm. Microdialysis probes were inserted into the jugular vein
and striatum of the rat. Following stabilization of microdialysate levels, rats
received cefotaxime (20 mg/kg, i.v., n=6) via the femoral vein, and complete
concentration versus time profiles for blood and striatum were constructed. The
results indicated that cefotaxime rapidly (within 10 min) entered the
extracellular fluid of brain striatum following intravenous administration.
Noncompartmental pharmacokinetics analysis indicated that the area under the
concentration versus time ratio of cefotaxime in rat brain and blood was 6.9%,
suggesting appreciable blood-brain barrier penetration. The method was relatively
simple, imposed minimal physiological perturbance as it involved no body fluid
consumption and sampled in particular protein-unbound drugs, generally believed
to be the active fraction.
PMID- 10778929
TI - Determination of a novel thrombin inhibitor in human plasma and urine utilizing
liquid chromatography with tandem mass spectrometric and ultraviolet detection.
AB - An LC-MS-MS method and an HPLC-UV method have been developed for the assay of a
novel thrombin inhibitor in human fluids. The LC-MS-MS method is developed for
plasma, which usually requires maximum sensitivity. The HPLC-UV method is for
urine. In both methods, analytes are extracted using liquid-liquid extraction,
and analyzed by reversed-phase high-performance liquid chromatography. A tandem
mass spectrometer in the multiple reaction monitoring (MRM) mode is used for
detection of the analytes in the plasma method. UV is the detector for the urine
method. The plasma method has a lower limit of quantitation (LOQ) of 0.1 ng/ml
with a linearity range of 0.1-100 ng/ml. The urine method has an LOQ of 8.12
ng/ml (20 nM) and the linear dynamic range is 8.12-8120 ng/ml (20-20000 nM). Both
methods are fast, specific and sensitive. Various validation procedures have
proven that both methods are rugged, robust and reproducible. The research also
suggested that, while LC-MS-MS provides superior sensitivity and selectivity for
the determination of drugs and their metabolites at very low concentrations, HPLC
with a conventional detector such as UV is still useful in the analysis when the
sensitivity requirement is not crucial.
PMID- 10778930
TI - High-performance liquid chromatographic analysis of the anti-fungal agent SCH
56592 in dog serum.
AB - SCH 56592 is a novel triazole antifungal agent that is active both orally and
intravenously. This compound is in phase II-III clinical trials for the treatment
of systemic fungal infections. A high-performance liquid chromatographic (HPLC)
method was developed for the analysis of SCH 56592 in serum of dogs, a species
used for safety evaluation. The HPLC analysis involved protein precipitation with
methanol followed by separation on a C18 column and quantitation by UV absorbance
at 262 nm. The method was sensitive with a limit of quantification of 0.05
microg/ml in dog serum. The linearity was satisfactory as indicated by
correlations of >0.996, in addition to visual examination of the calibration
curves. The precision and accuracy were satisfactory as indicated by coefficients
of variation (C.V.) ranging from 2.0 to 3.8%, and bias values ranging from -6.5
to 10%. Moreover, SCH 56592 was stable in dog serum after being subjected to
three freeze-thaw cycles. The assay was shown to be sensitive, specific,
accurate, precise, and reliable for use in pharmacokinetic or toxicokinetic
studies.
PMID- 10778931
TI - Determination of isotopic enrichments of [1-13C]homocysteine, [1-13C]methionine
and [2H3-methyl-1-13C]methionine in human plasma by gas chromatography-negative
chemical ionization mass spectrometry.
AB - We describe a reliable method for the simultaneous determination of isotopic
enrichments of [1-13C]homocysteine, [1-13C]methionine and [2H3-methyl-1
13C]methionine in human plasma. Accurate [1-13C]homocysteine calibration
standards were prepared by chemical conversion via thiolactonisation of [1
13C]methionine standards. Based upon anion-exchange chromatography, (di)acetyl
3,5-bis-trifluoromethylbenzyl derivatives, preparation of accurate calibration
curves and gas chromatography-negative chemical ionization mass spectrometry,
isotopic enrichments in human plasma could be determined with TTR (%) <+/-0.2%
(N=3) for [1-13C]homocysteine (enrichment range 0-8%), [1-13C]methionine
(enrichment range 0-3%) and [2H3-methyl-1-13C]methionine (enrichment range 0
12%). The method was applied in a [2H3-methyl-1-13C]methionine tracer infusion
study in a biological model.
PMID- 10778932
TI - Studies on the metabolism and toxicological detection of the amphetamine-like
anorectic fenproporex in human urine by gas chromatography-mass spectrometry and
fluorescence polarization immunoassay.
AB - Studies on the metabolism and the toxicological analysis of fenproporex (R,S-3
[(1-phenyl-2-propyl)-amino]-propionitrile, FP) using GC-MS and fluorescence
polarization immunoassay are described. The metabolites were identified in urine
samples of volunteers by GC-MS after cleavage of conjugates, extraction and
acetylation. Besides unchanged FP, fourteen metabolites, including amphetamine,
could be identified. Two partially overlapping metabolic pathways could be
postulated: ring degradation by one- and two-fold aromatic hydroxylation followed
by methylation and side chain degradation by N-dealkylation to amphetamine (AM).
A minor pathway leads via beta-hydroxylation of AM to norephedrine. For GC-MS
detection, the systematic toxicological analysis procedure including acid
hydrolysis, extraction at pH 8-9 and acetylation was suitable (detection limits
50 ng/ml for FP and 100 ng/ml for AM). Excretion studies showed, that only AM but
neither FP nor its specific metabolites were detectable 30-60 h after ingestion
of 20 mg of FP. Therefore, misinterpretation can occur. The Abbott TDx FPIA
amphetamine/methamphetamine II gave positive results up to 58 h. All the positive
immunoassay results could be confirmed by the described GC-MS procedure.
PMID- 10778933
TI - Simultaneous determination of endogenous and 13C-labelled cortisols and
cortisones in human plasma by stable isotope dilution mass spectrometry.
AB - This study describes a capillary GC-MS method for the simultaneous determination
of endogenous cortisol and cortisone and their 13C-labelled analogues, [1,2,4,19
13C4]cortisol (cortisol-13C4) and [1,2,4,19-13C4]cortisone (cortisone-13C4), in
human plasma. [1,2,4,19-13C4,1,1,19,19,19-2H5]Cortisol (cortisol-13C4,2H5) and
[1,2,4,19-13C4,1,1,19,19,19-2H5]cortisone (cortisone-13C4,2H5) were used as
analytical internal standards. A double derivatization (bismethylenedioxy
pentafluoropropionate, BMD-PFP) with good GC behavior was employed for the GC-MS
analysis of cortisol and cortisone. Quantitation was carried out by selected-ion
monitoring of the molecular ions ([M]+*) of the BMD-PFP derivatives of cortisol
and cortisone. The sensitivity limit of the present GC-MS-SIM method was found to
be 150 pg per injection for cortisol (s/n=5.0) and 50 pg for cortisone (s/n=8.1).
The within-day reproducibility in which the amounts of unlabelled and labelled
cortisols and cortisones determined were in good agreement with the actual
amounts added, the relative errors being less than 3.07%. The inter-assay
coefficients of variation (C.V.) were less than 1.80% for unlabelled and labelled
cortisols and cortisones.
PMID- 10778934
TI - Automated quantitative determination of the new renin inhibitor CGP 60536 by high
performance liquid chromatography.
AB - A fully automated high-performance liquid chromatography method with fluorescence
detection for the determination of the renin inhibitor CGP 60536 in animal and
human plasma and urine has been developed and validated. After addition of an
internal standard, the compounds were automatically extracted from 400 microl of
plasma or urine with methyl alcohol-acetic acid (99:1, v/v) on 100-mg Bond-Elut
CN cartridges using the Gilson ASPEC system. The on-line chromatographic
separation was performed on a LiChrospher 100 RP8 5-microm particle size packed
analytical column (25x0.4 cm I.D.). The mobile phase consisted of acetonitrile
0.01 M potassium dihydrogenphosphate (65:35, v/v) at a flow-rate of 0.8 ml/min.
The analytes were detected using a fluorescence detector at excitation and
emission wavelengths of 280 and 330 nm, respectively. The limit of quantitation
was established at 4.5 ng/ml in plasma (accuracy 106% and precision 1%), and 9.0
ng/ml in urine (accuracy 101% and precision 13%). The method was applied to the
investigation of the pharmacokinetics of CGP 60536.
PMID- 10778935
TI - Rapid and highly sensitive method for the determination of verapamil,
[2H7]verapamil and metabolites in biological fluids by liquid chromatography-mass
spectrometry.
AB - A rapid and highly sensitive method for the determination of verapamil [2,8-bis
(3,4-dimethoxyphenyl)-6-methyl-2-isopropyl-6-azaoctanitrile+ ++] and
[2H7]verapamil and their primary metabolites D-617 [2-(3,4-dimethoxyphenyl)-5
methylamino-2-isopropylvaleronitrile], D-703 [2-(4-hydroxy-3-methoxyphenyl)-8
(3,4-dimethoxy-phenyl)-6-methyl-2-iso-p ropyl-6-azaoctanitrile], D-702 [2-(3,4
dimethoxy-phenyl)-8-(4-hydroxy-3-methoxyphenyl)-6-methyl-2-isopr opyl-6
azaoctanitrile], norverapamil [2,8-bis-(3,4-dimethoxyphenyl)-2-isopropyl-6
azaoctanitrile] and secondary metabolites D-620 [2-(3,4-dimethoxyphenyl)-5-amino
2-isopropylvaleronitrile], D-717 [2-(4-hydroxy-3-methoxyphenyl)-5-amino-2
isopropylvaleronitrile], and D-715 [2-(4-hydroxy-3-methoxyphenyl)-8-(3,4
dimethoxy-phenyl)-2-isopropyl-6-++ +azaoctanitrile] has been developed using high
performance liquid chromatography-electrospray mass spectrometry. D-832, the
gallopamil analogue of D-617 and [2H3]norverapamil were used as internal
standards. The analytes were extracted automatically from plasma and intestinal
perfusate using end-capped CN- and C2 solid-phase extraction cartridges.
Separation of the eight analytes was achieved on a LUNA C8 analytical column
(150x2 mm I.D., 5 microm particle size) with 5 mM ammonium acetate-acetonitrile
as the mobile phase run with a gradient from 70:30 to 40:60 and run times of 15
min. With the mass spectrometer operated in the selected-ion monitoring mode, the
limits of quantification in plasma and intestinal perfusate were 1 pmol/ml for D
620, D-617, D-702, D-703, norverapamil, verapamil, and [2H7]verapamil and 2.5
pmol/ml for D-717 and D-715 using a sample size of 1 ml plasma and intestinal
perfusate. The method described was successfully applied to the determination of
verapamil, [2H7]verapamil and their metabolites in human plasma and intestinal
fluid in pharmacokinetic studies.
PMID- 10778936
TI - Chromatographic behavior of mouse serum immunoglobulin G in protein G perfusion
affinity chromatography.
AB - In this study chromatographic behavior of mouse serum immunoglobulin G (IgG) on a
protein G perfusion affinity chromatographic column was investigated
experimentally. The results indicate that the protein G column has no non
specific binding to the other proteins in mouse serum but an irreversible
adsorption to IgG under the conditions investigated. It was found that variations
of the elution solution composition, ionic strength and pH played to some extent
an essential effect on the chromatographic behavior of IgG. The influence of the
mobile phase flow-rate on the chromatographic behavior of IgG was also
researched. These results show that the dissociation of IgG from protein G
affinity packings becomes the rate-limiting step in the perfusion affinity
chromatographic separation process.
PMID- 10778937
TI - Liposomal lurtotecan (NX211): determination of total drug levels in human plasma
and urine by reversed-phase high-performance liquid chromatography.
AB - Lurtotecan (GI147211; LRT) is a semisynthetic and water-soluble analogue of the
topoisomerase I inhibitor camptothecin. To determine whether the therapeutic
efficacy of LRT in patients could be improved, the drug was encapsulated in
liposomes (NX211; Gilead Sciences). In order to allow accurate description of the
pharmacokinetic behavior of NX211 in cancer patients, we have developed sensitive
RP-HPLC assays with fluorescence detection (lambdaex=378 nm; lambdaem=420 nm) for
the determination of total LRT levels in human plasma and urine. Sample
pretreatment involved deproteinization with 10% (w/v) aqueous perchloric acid
acetonitrile (2:1, v/v), and chromatographic separations were achieved on an
Inertsil-ODS 80A analytical column. The lower limit of quantitation (LLQ) was
established at 1.00 ng/ml in plasma (200-microl sample) and at 100 ng/ml in urine
(200 microl of 40-fold diluted sample). The within-run and between-run precisions
were <7.5%. LRT concentrations in urine of <100 ng/ml were determined by a
modified procedure comprising a single solvent extraction with n-butanol-diethyl
ether (3:4, v/v). In this assay, the fluorescence signal of LRT was increased 14
fold prior to detection by post-column exposure to UV light (254 nm) in a
photochemical reaction unit. The LLQ of this assay was 0.500 ng/ml (150-microl
sample) and the within-run and between-run precisions were <10%.
PMID- 10778938
TI - Determination of 18alpha-glycyrrhizin and 18beta-glycyrrhizin in dog plasma by
high-performance liquid chromatography.
AB - A high-performance liquid chromatographic method has been developed for the
separation and determination of 18alpha-glycyrrhizin (alpha-GZ) and 18beta
glycyrrhizin (beta-GZ) in dog plasma. The two compounds were separated on a
reversed-phase column and detected by UV absorption at 254 nm. The mobile phase
was a mixture of water-methanol-60% perchloric acid (45:55:0.5, v/v) and was
adjusted to pH 8.0 with 25% ammonia solution. Indomethacin was added to the
plasma as an internal standard. Methanol was selected for the extraction of both
the compounds and internal standard. Alpha-GZ and beta-GZ could be precisely
determined in concentration of 1 mg/ml in a 0.1 ml sample.
PMID- 10778939
TI - Simple and sensitive high-performance liquid chromatographic.
AB - A rapid, selective, sensitive, and reproducible reversed-phase HPLC procedure for
the quantitative determination of mycophenolic acid (MPA)--an active plasma
metabolite of the immunosuppressant mycophenolate mofetil (MMF) in plasma is
described. The procedure involves one-step extraction of MPA and the internal
standard, standard [RS-60461-000: (E)-6-[1,3-dihydro-4-(4-carboxy-butoxy)-6
methoxy-7-methyl-3-oxo-5-is obenzo-furanyl-4-methyl-4-hexenoic acid] with
dichloromethane-dichloroethane (1:1, v/v) at acidic pH. Chromatographic
separation consisted of the mobile phase [acetonitrile-0.05% phosphate buffer, pH
3.4 (45:55, v/v)] running through the column (Techopak-10 C18) at flow-rate of
0.8 ml/min. Detection was at UV wavelength of 254 nm. The mean recoveries of MPA
and the internal standard at concentrations of 0.1 and 20 microg/ml were 89-98%,
and 90-96%, respectively. The within-day coefficients of variation for MPA were
0.3-7.8% and the day-to-day coefficients of variation were 1.1-2.0%. The minimum
detectable concentrations for both MPA and the internal standard in plasma were
0.005 microg/ml. The method was found to be suitable for use in clinical
pharmacokinetic study.
PMID- 10778940
TI - Rapid microbore liquid chromatographic analysis of biphenyldimethyl dicarboxylate
in human plasma with on-line column switching.
AB - A fully automated method including microbore liquid chromatography and column
switching was developed for the analysis of biphenyldimethyl dicarboxylate (DDB)
from human plasma samples. After direct injection of plasma samples (100 microl)
into the system, deproteinization and analyte fractionation occurred on a Capcell
Pak MF Ph-1 column (20x4 mm I.D.) and the DDB fraction was transferred from the
MF Ph-1 column to an intermediate column (35x2 mm I.D.) using 15% acetonitrile in
phosphate buffer (50 mM, pH 7.0). The main separation was performed on a
microbore C18 column (150x1.5 mm I.D.) using 45% acetonitrile in water. The
method showed excellent sensitivity (detection limit of 5 ng/ml) and good
precision (CV.< or =3.0%), and shortened total analysis time (20 min). In the
concentration range of 5-200 ng/ml, the mean recovery was 90.7+/-1.8% and the
response was linear (r2> or =0.999).
PMID- 10778941
TI - Detection of mycoloylglycerol by thin-layer chromatography as a tool for the
rapid inclusion of corynebacteria of clinical origin in the genus
Corynebacterium.
AB - A chemotaxonomic study of some corynebacteria isolated from clinical samples
revealed characteristic thin-layer chromatographic patterns for meso
diaminopimelic acid containing species included in the genera Corynebacterium,
Dermabacter and Brevibacterium. Notably, a specific compound was consistently
detected in mycolic acid containing species of the genus Corynebacterium. This
compound was composed by glycerol and mycolic acids and structural analyses
carried out by fast atom bombardment mass spectrometry in C. minutissimum
confirmed its identification as mycoloylglycerol. The chain length of mycoloyl
groups in this molecule ranged from 28 to 34 carbon atoms, being mono-, di- or
triunsaturated. Detection of mycoloylglycerol by thin-layer chromatography may be
thus useful for the rapid inclusion of a great variety of corynebacteria of
clinical origin in the genus Corynebacterium in laboratories employing
chromatographic techniques as an adjunct for the identification of these
microorganisms.
PMID- 10778942
TI - Cytochrome P-450 and other determinants of pharmacokinetics, toxicity, and
efficacy in humans.
PMID- 10778943
TI - Clinical pharmacokinetics of oxaliplatin: a critical review.
AB - Oxaliplatin (cis-[(1R,2R)-1,2-cyclohexanediamine-N,N'] oxalato(2-)-O,O']
platinum; Eloxatine) is a novel platinum coordination complex used for the
treatment of metastatic colorectal carcinoma in combination with
fluoropyrimidines. The objective of this review is to integrate the key data from
multiple studies into a single, comprehensive overview of oxaliplatin disposition
in cancer patients. The pharmacokinetics (PKs) of unbound platinum in plasma
ultrafiltrate after oxaliplatin administration was triphasic, characterized by a
short initial distribution phase and a long terminal elimination phase (t1/2, 252
273 h). No accumulation was observed in plasma ultrafiltrate after 130 mg/m2
every 3 weeks or 85 mg/m2 every 2 weeks. Interpatient and intrapatient
variability in platinum exposure (area under the curve(0-48)) is moderate to low
(33 and 5% respectively). In the blood, platinum binds irreversibly to plasma
proteins (predominantly serum albumin) and erythrocytes. Accumulation of platinum
in blood cells is not considered to be clinically significant. Platinum is
rapidly cleared from plasma by covalent binding to tissues and renal elimination.
Urinary excretion (53.8 +/- 9.1%) was the predominant route of platinum
elimination, with fecal excretion accounting for only 2.1 +/- 1.9% of the
administered dose 5 days postadministration. Tissue binding and renal elimination
contribute equally to the clearance of ultrafilterable platinum from plasma.
Renal clearance of platinum significantly correlated with glomerular filtration
rate, indicating that glomerular filtration is the principal mechanism of
platinum elimination by the kidneys. Clearance of ultrafilterable platinum is
lower in patients with moderate renal impairment; however, no marked increase in
drug toxicity was reported. The effect of severe renal impairment on platinum
clearance and toxicity is currently unknown. Covariates such as age, sex, and
hepatic impairment had no significant effect on the clearance of ultrafilterable
platinum, and dose adjustment due to these variables is not required. Oxaliplatin
undergoes rapid and extensive nonenzymatic biotransformation and is not subjected
to CYP450-mediated metabolism. Up to 17 platinum-containing products have been
observed in plasma ultrafiltrate samples from patients. These include several
proximate cytotoxic species, including the monochloro-, dichloro-, and diaquo
diaminocyclohexane platinum complexes, along with several other noncytotoxic
products. Oxaliplatin does not inhibit CYP450 isoenzymes in vitro. Platinum was
not displaced from plasma proteins by a variety of concomitant medications tested
in vitro, and no marked PK interactions between oxaliplatin, 5-fluorouracil, and
irinothecan have been observed. These results indicate that the
additive/synergistic antitumor activity observed with these agents is not due to
major alterations in drug exposure, and the enhanced efficacy is likely to be
mechanistically based. Together, these PK, biotransformation, drug-drug
interaction analyses and studies in special patient populations provide a firm
scientific basis for the safe and effective use of oxaliplatin in the clinic.
These analyses also reveal that the pharmacological activity of oxaliplatin may
be attributable, at least in part, to the unique pattern of platinum disposition
observed in patients.
PMID- 10778944
TI - Universal inactivation of both p16 and p15 but not downstream components is an
essential event in the pathogenesis of T-cell acute lymphoblastic leukemia.
AB - p16/p15 regulate the cell cycle pathway by inhibiting the cyclin Ds-CDK4/6
mediated phosphorylation of pRb. We reported previously that in T-cell acute
lymphoblastic leukemia (T-ALL), p16 and p15 were frequently (approximately 70%)
inactivated at the DNA level by deletion, mutation, or hypermethylation.
Therefore, we hypothesize that inactivation of the cell cycle regulatory pathway
may be essential in the pathogenesis of T-ALL, and that the remaining T-ALL with
a wild-type p16/p15 gene likely harbor inactivation of these genes at RNA or
protein levels. Alternatively, the downstream components of the pathway including
CDK4/6, cyclin Ds, and pRb may be deregulated. In 124 primary T-ALLs, we found
inactivation of the p16 and p15 genes at the DNA level in 79 (64%) and 64 (52%)
samples, respectively. Only 9 of the 45 samples with wild-type p16 expressed p16
protein, whereas the remaining 36 lacked p16 expression at the RNA or protein
level. In the 60 samples with an intact p15 gene, only 2 expressed p15 mRNA, and
the only one analyzed lacked p15 protein. Overall, the abrogation rates for p16
and p15 at DNA/RNA/protein levels were 93% (115 of 124) and 99% (123 of 124),
respectively. Although no alterations were evident in cyclin Ds or CDK4/6, pRb
was hyperphosphorylated in the majority of samples investigated. These findings
strongly support that both p16 and p15 are specific targets in the deregulation
of the cell cycle pathway in T-ALL and that the inactivation of these genes is
most likely essential in the pathogenesis of this disease.
PMID- 10778945
TI - Up-regulation of cyclooxygenase-2 in squamous carcinogenesis of the esophagus.
AB - Cyclooxygenase-2 (COX-2) is overexpressed in various types of human malignancies
including squamous cell carcinomas (SCCs) of the esophagus, but little is known
about COX-2 expression in premalignant esophageal squamous dysplasia. To
elucidate the role of COX-2 in esophageal carcinogenesis, we examined the
expression of this enzyme in normal squamous epithelium (n = 42), squamous
dysplasia [high-grade dysplasia (HGD, n = 41; low-grade dysplasia (LGD, n = 33)];
carcinoma in situ (n = 16), mucosal invasive carcinoma (n = 18), and advanced SCC
(n = 45). Immunohistochemistry showed a significantly high COX-2 expression in
HGD compared with other lesions. The COX-2 score, an index determined by
intensity and positivity of COX-2 staining (maximum 3.0), was 0.29 +/- 0.04 in
normal esophagus, 1.75 +/- 0.11 in LGD, 2.89 +/- 0.05 in HGD, 2.17 +/-0.18 in
CIS, 1.95 +/- 0.22 in mucosal invasive carcinoma, and 1.81 +/- 0.08 in advanced
SCC. Results of reverse transcription-PCR assays confirmed those obtained by
immunohistochemistry. COX-2 expression correlated with proliferation activity
assessed by the proliferating cell nuclear antigen index in dysplastic lesions (P
= 0.001) but not in SCCs. COX-2 expression in SCC did not correlate with various
clinicopathological parameters including prognosis. Our results indicate that COX
2 is a sensitive marker for HGD and suggest that COX-2 may be involved in early
stages of squamous carcinogenesis of the esophagus.
PMID- 10778946
TI - Adenoviral expression of p53 represses telomerase activity through down
regulation of human telomerase reverse transcriptase transcription.
AB - Telomerase activation is a critical step in cellular immortality and oncogenesis.
The activity of telomerase is known to be correlated with cell proliferation, but
its regulation by cell cycle regulators is not well understood. In the present
study, we examined the effects of p53 on telomerase activity. Wild-type p53 was
introduced into SiHa cells via a recombinant adenoviral vector, Ad5CMV-p53, and
change in telomerase activity was examined by quantitative telomerase assay.
Telomerase activity in the Ad5CMV-p53-infected cells was significantly repressed
36 h after infection following down-regulation of human telomerase catalytic
subunit [human telomerase reverse transcriptase (hTERT)] mRNA expression, whereas
no change in telomerase activity was observed in the cells infected with control
vector AdSCMV-beta-gal. Interestingly, repression of telomerase activity was an
early event that preceded cell growth inhibition or apoptosis induced by p53
overexpression, suggesting that p53 directly regulates telomerase activity.
Transient expression assays using hTERT-promoter reporter constructs revealed
that overexpression of p53 significantly repressed promoter activity of hTERT. 5'
Truncation of the promoter sequences revealed that the proximal core promoter
region containing multiple binding sites for transcription factor Spl was
responsible for p53-mediated transcriptional repression. Mutations in these
binding sites for Spl led to failure of p53 to repress transcription. These
findings suggest that p53 repressed telomerase activity through down-regulation
of hTERT transcription and that interaction of p53 with Sp1 or other
transcription factors may be involved in this regulation.
PMID- 10778947
TI - Carboxyamido-triazole induces apoptosis in bovine aortic endothelial and human
glioma cells.
AB - Carboxyamido-triazole (CAI), an inhibitor of non-voltage-gated calcium channels,
has been studied in Phase I/II clinical trials following the identification of
its inhibitory effects on tumor cell invasion and motility. It has also been
reported to inhibit human endothelial cell proliferation, migration, and adhesion
to the basement membrane. In glioma, biological assays have shown CAI to be
active in inhibiting the phenotypes of invasion and angiogenesis. The exact
mechanism of action is not clearly understood, although it appears to work via
inhibition of calcium influx in several signal transduction pathways that inhibit
cell cycle progression. Recent evidence implicates apoptosis as a contributing
mechanism of chemotherapy-induced tumor cytotoxicity. Therefore, we studied the
effects of CAI on apoptosis in bovine aortic endothelial cells and a human glioma
cell line (U251N) using a variety of methods, including: (a) cell morphology; (b)
terminal deoxynucleotidyl transferase-mediated nick end labeling analysis of in
situ DNA strand breaks; (c) agarose gel electrophoresis to visualize DNA
fragmentation; and (d) flow cytometry. Here we report that the kinetics of CAI
induced apoptosis in bovine aortic endothelial cells and glioma cells was
determined to be both dose and time dependent in micromolar concentrations
achievable in brain tissue in vivo.
PMID- 10778948
TI - The effect of an individual's cytochrome CYP3A4 activity on docetaxel clearance.
AB - Docetaxel is a chemotherapeutic agent effective in the treatment of various solid
tumors. Patients given a standard dose of docetaxel exhibit wide interpatient
variation in clearance (CL) and toxic effects. Docetaxel undergoes metabolism by
cytochrome CYP3A4. Thus, interpatient variability in CYP3A4 activity may account
in part for differences in toxicity and CL. Twenty-one heavily pretreated
patients with metastatic sarcomas received docetaxel (100 mg/m2). Hepatic CYP3A4
activity in each patient was measured by the [14C-N-methyl]erythromycin breath
test (ERMBT). Blood samples were taken at selected times over the next 24 h for
pharmacokinetic analysis. Phenotypic expression of hepatic CYP3A4 activity
measured by the ERMBT varied over 20-fold (administered 14C exhaled in 1 h: mean,
2.53%; range, 0.25-5.35%), which is similar to a normal control population. CL of
docetaxel varied nearly 6-fold (mean, 21.0 liters/h/m2; range, 5.4-29.1
liters/h/m2). The ERMBT was the best predictor of CL when compared with serum
alanine aminotransferase, albumin, alkaline phosphatase, or serum alpha-1-acidic
glycoprotein. The natural log of ERMBT accounted for 67% of the interpatient
variation in CL. Multivariate analysis showed that the natural log of ERMBT and
albumin together accounted for 72% of the interpatient variation in CL. The
greatest toxicity was seen in patients with the lowest ERMBT. Hepatic CYP3A4
activity is the strongest predictor of docetaxel CL and accounts for the majority
of interpatient differences in CL. Patients with low CYP3A4 activity are at risk
for having decreased CL and may thus experience increased toxicity from
docetaxel. Those with high activity may be receiving a suboptimal dose. By
measuring CYP3A4 activity, the ERMBT may be clinically useful in tailoring doses
of CYP3A4 substrates, such as docetaxel, in certain individuals.
PMID- 10778949
TI - A safety and pharmacokinetic study of a mixed-backbone oligonucleotide (GEM231)
targeting the type I protein kinase A by two-hour infusions in patients with
refractory solid tumors.
AB - GEM231 is a mixed-backbone oligonucleotide targeting the regulatory subunit alpha
of type I protein kinase A, which plays an important role in growth and
maintenance of malignancies. Preclinically, GEM231 inhibited human cancer
xenografts either alone or synergistically with chemotherapeutic agents and has
demonstrated an improved metabolic stability and safety profile compared to the
first-generation compounds. Objectives of this study were to define the safety
profile and pharmacokinetics of GEM231 administered as 2-h IV infusions twice
weekly in patients with refractory solid tumors. Fourteen patients (13 evaluable
for safety) received escalating doses of GEM231 at 20-360 mg/m2 (2.5-9 mg/kg).
Tumor histologies included non-small cell lung cancer, renal cell cancer,
sarcoma, and others. The plasma pharmacokinetics of GEM231 were linear and
predictable. Maximum plasma concentration (Cmax) reached 50-70 microg/ml (8-13
microM) at dose 360 mg/m2 and 27-32 microg/ml at dose 240 mg/m2. The plasma half
life was about 1.5 h. The only clinical toxicities were transient grade I-II
fever and fatigue at doses > or = 240 mg/m2. There was no treatment-related
complement activation or thrombocytopenia at any dose level, except with the
first dose in one patient who had pre-existing borderline thrombocytopenia.
Transient activated partial thrombin time prolongation occurred at doses > or
=160 mg/m2. Dose-limiting toxicities included transient activated partial
thrombin time prolongation (one of three patients at 360 mg/m2) and cumulative
reversible transaminase elevation (three of three patients at 360 mg/m2 and three
of six patients at 240 mg/m2 during weeks 3-10). One patient with colon cancer
had stabilization of a previously rising carcinoembryonic antigen. Thus, in this
first clinical evaluation of a mixed-backbone oligonucleotide in cancer patients,
high plasma concentrations of GEM231 were well tolerated without significant
acute toxicities, but prolonged treatment was associated with reversible
transaminitis. Although 240 mg/m2 by 2-h infusion twice weekly was safe for a 4
week treatment duration, alternative dosing schedules are being tested to
minimize the cumulative toxicity, which will be essential to extend the duration
of therapy at the highest GEM231 dose tested.
PMID- 10778950
TI - Phase I trial of combined immunotherapy with subcutaneous granulocyte macrophage
colony-stimulating factor, low-dose interleukin 2, and interferon alpha in
progressive metastatic melanoma and renal cell carcinoma.
AB - The purpose of our study was to determine the maximally tolerated dose (MTD) and
DLT of combined administration of granulocyte macrophage colony-stimulating
factor (GM-CSF), low-dose interleukin 2 (IL-2) and IFN-alpha in patients with
progressive metastatic melanoma or renal cell carcinoma (RCC). In addition, the
activation and expansion of effector cells were measured. Cohorts of three
patients were treated with increasing doses of IL-2 (1, 4, and 8 MIU/m2) and GM
CSF (2.5 and 5 microg/kg) with a constant dose of IFNalpha (5 million units) s.c.
for 12 days every 3 weeks. An additional six patients were treated at the MTD.
Immune activation was monitored during the first cycle. Response was evaluated
after two cycles. The MTD was found to be 2.5 microg/kg GM-CSF, 4 MIU/m2 IL-2,
and 5 mega units of IFNalpha. DLT was grade 4 fever, chills with hypotension,
grade 3 fatigue/malaise, and fluid retention. Dose reduction of IL-2 to 2 MIU/m2
was necessary in three of nine patients who initially received the MTD. Treatment
was initiated in the hospital but could be continued at home after 3-4 days.
Significant increases in lymphocytes, (activated) T cells (CD4+ and CD8+), NK
cells, monocyte DR expression, neutrophils, and eosinophils were found. CD8+ T
cell activation (sCD8) and NK cell expansion was mainly present in patients
receiving 2 or 4 MIU/m2 IL-2. Of eight patients with progressive metastatic RCC
after nephrectomy, three achieved a complete remission, and 1 of 7 patients with
metastatic melanoma achieved a partial remission. In our study, the MTD of
combined immunotherapy with GM-CSF, IL-2, and IFNalpha was established; DLT was:
(a) grade 4 fever with hypotension needing i.v. fluid support; and (b) grade 3
fluid retention and/or fatigue/malaise. The scheme resulted in considerable
expansion and/or activation of various effector cells. The complete responses in
RCC patients are promising but need to be confirmed in Phase II studies.
PMID- 10778951
TI - Mouse mammary tumor virus-like ENV gene sequences in human breast tumors and in a
lymphoma of a breast cancer patient.
AB - DNA sequences with very high similarity (95-98%) to the mouse mammary tumor virus
(MMTV) ENV gene have been amplified by PCR in 38.5% of human breast tumors and in
<2% of normal breast tissue (Wang et al., Cancer Res., 55: 5173-5179, 1995).
Intrigued by these findings, which suggested an exogenous viral etiology for a
certain percentage of human breast tumors, we have screened a panel of human
breast tumors and normal breast tissue for the presence of MMTV-like DNA
sequences. Using similar PCR procedures and stringent hybridization techniques,
we have detected the presence of MMTV-like ENV gene sequences in 37% of the human
breast tumors that we have analyzed. DNA sequencing has shown these sequences to
be 99% homologous to the BR6 strain of MMTV and 100% homologous to the GR and C3H
strains of MMTV. We have not detected these MMTV-like sequences in normal breast
tissue. However, we have detected these sequences by PCR and stringent
hybridization in a T-cell lymphoma of a breast cancer patient who was
simultaneously diagnosed with both diseases. Our results support the possibility
of an exogenous retroviral etiology for a certain percentage of human breast
tumors. Our results also suggest that a similar exogenous retroviral etiology may
exist for certain human T-cell lymphomas. In many inbred strains of mice, both
breast cancer and T-cell lymphoma are caused by MMTV, hence, in a certain
percentage of humans, one or both of these diseases may be caused by an MMTV-like
retroviral entity.
PMID- 10778952
TI - (F-18) fluorodeoxyglucose positron emission tomography as a predictor of
pathologic grade and other prognostic variables in bone and soft tissue sarcoma.
AB - Positron emission tomography (PET) can be used to measure tumor metabolism in
sarcomas by measuring the standard uptake value (SUV) of (F-18)
fluorodeoxyglucose (FDG). FDG-PET SUV has been shown to correlate with
histological grade. We compared FDG-PET SUV in 89 bone and soft tissue sarcomas
with histopathological features, including tumor grade, as well as with markers
of cell proliferation and cell cycle regulatory gene expression that may be
prognostically or therapeutically important. All patients had undergone PET
before biopsy. Features evaluated included grade (National Cancer Institute for
soft tissue or Mayo Clinic for bone), cellularity, and the number of mitoses per
10 400x fields. Deparaffinized, formalin-fixed sections were immunostained with
antibodies to Ki-67 (MIB-1), p53 (DO7), p21WAF1 (EA10), and mdm-2 (1B10). For Ki
67, results were estimated as a percentage of positive cells. For p53 and mdm-2,
only cases with >20% positive cells were considered to be overexpressing these
proteins. For p21WAF1, only cases with <10% positive cells were considered to
have lost normal p21WAF1 expression. Tumor S-phase percentage and ploidy were
determined by flow cytometry. FDG-PET SUV was associated with histopathological
grade, cellularity, mitotic activity, MIB labeling index, and p53 overexpression.
No association was seen with p21WAF1, mdm-2, S-phase fraction, or ploidy. Tumor
metabolism data acquired by FDG-PET may help ensure accurate grading and
prognostication in sarcoma by guiding biopsy toward the most biologically
significant regions of large masses. Further follow-up will be necessary to
determine whether FDG-PET provides independent prognostic information.
PMID- 10778953
TI - Topotecan lacks third space sequestration.
AB - The objective of this study was to determine the influence of pleural and ascitic
fluid on the pharmacokinetics of the antitumor camptothecin derivative topotecan.
Four patients with histological proof of malignant solid tumor received topotecan
(0.45 or 1.5 mg/m2) p.o. on several occasions in both the presence and absence of
third space volumes. Serial plasma and pleural or ascitic fluid samples were
collected during each dosing and analyzed by high-performance liquid
chromatography for both the intact lactone form of topotecan and its ring-opened
carboxylate form. The apparent topotecan clearance demonstrated substantial
interpatient variability but remained unchanged within the same patient in the
presence [110 +/- 55.6 liters/ h/m2 (mean +/- SD of eight courses)] or absence of
pleural and ascitic fluid [118 +/- 31.1 liters/h/m2 (mean +/- SD of seven
courses)]. Similarly, terminal half-lives and area under the concentration-time
curve ratios of lactone:total drug in plasma were similar between courses within
each patient. Topotecan penetration into pleural and ascitic fluid demonstrated a
mean lag time of 1.61 h (range, 1.37-1.86 h), and ratios with plasma
concentration increased with time after dosing in all patients. The mean ratio of
third space topotecan total drug area under the concentration-time curve to that
in plasma was 0.55 (range, 0.26-0.87). These data indicate that topotecan can be
safely administered to patients with pleural effusions or ascites and that there
is substantial penetration of topotecan into these third spaces, which may prove
beneficial for local antitumor effects.
PMID- 10778954
TI - Novel marine-derived anticancer agents: a phase I clinical, pharmacological, and
pharmacodynamic study of dolastatin 10 (NSC 376128) in patients with advanced
solid tumors.
AB - Dolastatin (DOLA)-10 is a pentapeptide isolated from the mollusc Dolabella
auricularia with clinically promising antitumor activity documented in various in
vitro and in vivo tumor models. The objectives of this Phase I study were to
determine the maximum tolerated dose, evaluate toxic effects, and document any
antitumor activity of this novel agent. Using an electrospray ionization mass
spectroscopy system, we also characterized the clinical pharmacokinetics,
pharmacodynamics, and metabolism of DOLA-10. The maximum tolerated dose was
reached at 300 microg/m2. Granulocytopenia, the dose-limiting toxicity, was
documented in 33% of the patients treated at that dose level. There were no
episodes of thrombocytopenia or severe anemia (Hgb < 8), and no major
nonhematological toxicity was observed. Stabilization of tumor growth was
observed in four patients, but no objective responses were seen. Whereas a two
compartment model described the DOLA-10 plasma concentration-time data reasonably
well, a three-compartment model consistently performed better. After a rapid
distribution phase, DOLA-10 plasma levels declined with mean beta and gamma half
lives of 0.99 and 18.9 h, respectively. Significant interpatient and intrapatient
variability in DOLA-10 plasma clearances was observed. The mean area under the
concentration-time curve increased proportionally as the dose was escalated, but
there was significant overlap between dose levels. The area under the
concentration-time curve and the percentage of decline in neutrophils were
correlated. A single DOLA-10 metabolite was detected in five patients. Unlike the
in vitro studies of DOLA-10, the principal metabolite detected was an N-demethyl
derivative, confirmed by mass spectroscopy. In all five subjects, the
concentration of this metabolite never exceeded 2% of the simultaneously measured
parent drug concentration. The available preclinical, pharmacological, and
clinical data suggest that further study of escalated DOLA-10 dosing with
cytokine support is warranted.
PMID- 10778955
TI - A phase I study of combination therapy with immunotoxins IgG-HD37-deglycosylated
ricin A chain (dgA) and IgG-RFB4-dgA (Combotox) in patients with refractory
CD19(+), CD22(+) B cell lymphoma.
AB - This study used an 8-day continuous infusion regimen of a 1:1 mixture of two
immunotoxins (ITs) prepared from deglycosylated ricin A chain (dgA) conjugated to
monoclonal antibodies directed against CD22 (RFB4-dgA) and CD19 (HD37-dgA;
Combotox) in a Phase I trial involving 22 patients with refractory B cell
lymphoma to determine the maximum tolerated dose, clinical pharmacology, and
toxicity profile and to characterize any clinical responses. Adult patients
received a continuous infusion of Combotox at 10, 20, or 30 mg/m2/192 h. No
intrapatient dose escalation was permitted. Patients with > or =50 circulating
tumor cells (CTCs)/mm3 in peripheral blood tolerated all doses without major
toxicity. The maximum level of serum IT (Cmax) achieved in this group was 345
ng/ml of RFB4-dgA and 660 ng/ml of HD37-dgA (1005 ng/ml of Combotox). In
contrast, patients without CTCs (<50/mm3) had unpredictable clinical courses that
included two deaths probably related to the IT. Additionally, patients exhibited
a significant potential for association between mortality and a history of either
autologous bone marrow or peripheral blood stem cell transplants (P2 = 0.003) and
between mortality and a history of radiation therapy (P2 = 0.036). In patients
with CTCs, prior therapies appeared to have little impact on toxicity. Subsequent
evaluation of the ITs revealed biochemical heterogeneity between two lots of HD37
dgA. In addition, HD37-dgA thawed at the study site tended to contain significant
particulates, which were not apparent in matched controls stored at the
originating site. This suggests that a tendency to aggregate may have resulted
from shipping, storage, and handling of the IT that occurred prior to preparation
for administration. It is not clear to what extent, if any, the aggregation of
HD37-dgA IT was related to the encountered clinical toxicities; however, the
potential to aggregate does suggest one possible basis for problems in our
clinical experience with HD37-dgA and leads us to the conclusion that non
aggregate-forming formulations for these ITs should be pursued prior to future
clinical trials.
PMID- 10778956
TI - Intravenous ifosfamide/mesna is associated with depletion of plasma thiols
without depletion of leukocyte glutathione.
AB - Depletion of cellular glutathione (GSH) enhances the efficacy of many anticancer
agents in preclinical systems. Limited published data showing depletion of GSH in
vitro and in patients by ifosfamide and/or mesna provided the rationale for a
Phase I trial. Ifosfamide and mesna were infused over 24 and 36 h, respectively,
at equal daily doses; carboplatin was given after ifosfamide to a target plasma
area under the curve of 4 mg x min x ml(-1). Plasma and peripheral WBC thiols
were quantitated by high-performance liquid chromatography. The dose of
ifosfamide was escalated from 2 to 8 g/m2; the maximum tolerated dose was 6 g/m2.
Significant depletion in plasma cysteine and homocysteine, precursors for GSH
synthesis, was observed (maximum, 95% to >99% at 8 g/m2). Plasma mesna and
cysteine/ homocysteine levels were inversely correlated; nadir levels of
cysteine/homocysteine were maintained for several hours after ifosfamide infusion
had stopped and while mesna infusion was continuing. In vitro coincubation
experiments confirmed that mesna reduces these thiols from disulfides to
sulfhydryls, which are readily cleared, as evidenced by the significantly
increased rate of excretion of cysteine in urine. In contrast, ifosfamide/mesna
treatment caused a moderate depletion of plasma GSH in only 60% of the patients,
with a nadir at 24 h and recovery immediately after the end of ifosfamide
infusion. The GSH depletion in these patients was not dose related. The profile
of GSH recovery in plasma after ifosfamide and the fact that mesna could not
reduce GSH disulfides in vitro suggest that the observed GSH depletion in plasma
in 60% of the patients may be related to direct reactions of GSH with ifosfamide
metabolites and/or mesna. Our results indicate that mesna is a modulator of GSH
precursors and that a prolonged infusion of mesna may be required to achieve GSH
precursor starvation and the consequent GSH depletion in cells.
PMID- 10778957
TI - Colorectal tumors responding to 5-fluorouracil have low gene expression levels of
dihydropyrimidine dehydrogenase, thymidylate synthase, and thymidine
phosphorylase.
AB - We had previously shown that high gene expressions (mRNA levels) of thymidylate
synthase (TS; Leichman et al., J. Clin. Oncol., 15: 3223-3229, 1997) and
thymidine phosphorylase (TP; Metzger et al., Clin. Cancer Res., 4: 2371-2376,
1998) in pretreatment tumor biopsies could identify tumors that would be
nonresponsive to 5-fluorouracil (5-FU)-based therapy. In this study, we
investigated the association between intratumoral gene expression of the
pyrimidine catabolism enzyme dihydropyrimidine dehydrogenase (DPD) and the
response of colorectal tumors to the same 5-FU-based protocol. DPD expressions
were measured by quantitative reverse transcription-PCR in 33 pretreatment
biopsies of colorectal tumors from patients who went on to receive treatment with
5-FU and leucovorin (LV). The range of DPD gene expression in those tumors that
were nonresponsive to 5-FU was much broader than that of the responding tumors.
None of the tumors with basal-level DPD expressions above a DPD:beta-actin ratio
of 2.5 x 10(-3) (14 of 33) were responders to 5-FU/LV therapy, whereas those
tumors with DPD gene expressions below DPD: beta-actin ratio of 2.5 x 10(-3) had
a response rate of 50%. There was no correlation among DPD, TS, and TP expression
values in this set of colorectal tumors, which indicated that these gene
expressions are independent variables. All of the tumors that responded to 5-FU
therapy (11 of 33) had expression values of all three of the genes, TS, TP, and
DPD, below their respective nonresponse cutoff values, whereas, in each of the
nonresponding tumors, at least one of these gene expressions was high. The
patients with low expression of all three of the genes had significantly longer
survival than patients with a high value of any one of the gene expressions. The
results of this study show that intratumoral gene expression level of DPD is
associated with tumor response to 5-FU and that the use of more than one
independent determinant of response permits the identification of a high
percentage of responding patients.
PMID- 10778958
TI - Sequential treatment of a resistant chronic lymphocytic leukemia patient with
bryostatin 1 followed by 2-chlorodeoxyadenosine: case report.
AB - Bryostatin 1 (Bryo-1) has been shown to differentiate chronic lymphocytic
leukemia (CLL) cells to the hairy cell leukemia phenotype. The purine analogue 2
chlorodeoxyadenosine (2-CdA) exhibits enhanced activity in patients with hairy
cell leukemia compared to those with CLL. Here we present a case report of a
patient diagnosed with resistant CLL and treated sequentially with Bryo-1
followed by 2-CdA for three cycles. Molecular and biochemical parameters relative
to the sequential treatment with these agents in vivo were comparable to those
found in the WSU-CLL cell line in vitro (R. M. Mohammad et al., Clin. Cancer
Res., 4: 445-453, 1998; R. M. Mohammad et al., Biol. Chem., 379: 1253-1261,
1998). There was a significant reduction of lymphocyte count from 37.1 x
10(3)/microl before the treatment to 3.4 x 10(3)/microl after treatment, and
partial remission was achieved 2 months after the treatment. The percentage of
morphologically differentiated lymphocytes was increased from 3% before treatment
to 92% with the first cycle of Bryo-1. Similarly, expression of CD22, a marker of
differentiation, increased from 38% to 97% and was maintained at a high level for
the duration of the treatment. Analysis of the molecular markers of apoptosis in
isolated peripheral blood lymphocytes revealed an increase in the Bax:Bcl-2 ratio
after treatment with Bryo-1 in cycles 2 and 3, with associated poly(ADP-ribose)
polymerase cleavage after Bryo-1 and 2-CdA treatment. The deoxycytidine kinase:
cytosolic 5'-nucleotidase activity ratio increased modestly after Bryo-1
treatment, indicating increased sensitivity of the peripheral blood lymphocytes
to 2-CdA. In summary, we found that sequential treatment with Bryo-1 and 2-CdA
caused a significant reduction in peripheral blood lymphocytes (CLL cells) with
simultaneous induction of differentiation and the initiation of the Bax: Bcl-2
apoptotic pathway.
PMID- 10778959
TI - A multicenter phase II trial of losoxantrone (DuP-941) in hormone-refractory
metastatic prostate cancer.
AB - Our purpose in this study was to determine the efficacy and toxicity of
losoxantrone (DuP-941), an anthrapyrazole, in patients with metastatic hormone
refractory prostate cancer. Patients with metastatic prostate cancer progressing
on androgen ablation therapy without demonstrable antiandrogen withdrawal
response were treated with losoxantrone 50 mg/m2 i.v. bolus every 21 days. All of
the patients had elevated serum prostate-specific antigen (PSA) before study
entry and had no prior chemotherapy. Forty-three assessable patients were
entered. The median age was 70.6 years (range, 53.9-85.9), median Karnofsky
performance scale (KPS), 70% (50-90%), and the median serum PSA, 173 microg/liter
(12.5-11,140). The median number of courses was 4 (1-9). Five patients (25%) had
a partial response as defined by >50% decline in the serum PSA. Two of nine
patients with measurable disease had partial responses and three had minor
responses. Thirty percent of patients had improvement in KPS and 37% had an
improvement in symptoms with decrease in pain and/or decrease in analgesic
requirement. Nonhematological grade 3 and 4 toxicities were one each of grade 3
headache, grade 4 hypocalcemia, grade 3 hyperbilirubinemia, and grade 3 dyspnea.
Twenty-six patients (60%) had grade 3 or 4 absolute neutropenia. In conclusion,
losoxantrone demonstrated a partial biochemical response rate of 25%, response in
measurable disease sites in 22%, and improvement in clinical symptoms in one
third of patients. In this study, PSA increase was not necessarily associated
with lack of palliative response.
PMID- 10778960
TI - 7-monohydroxyethylrutoside protects against chronic doxorubicin-induced
cardiotoxicity when administered only once per week.
AB - Doxorubicin is a very effective antitumor agent, but its clinical use is limited
by the occurrence of a cumulative dose-related cardiotoxicity, resulting in
congestive heart failure. 7-Monohydroxyethylrutoside (monoHER), a flavonoid
belonging to the semisynthetic hydroxyethylrutoside family, has been shown to
protect against doxorubicin-induced cardiotoxicity when administered i.p. at a
dose of 500 mg/kg five times/week in combination with a weekly i.v. dose of
doxorubicin. Such a dosing schedule would be very inconvenient in clinical
practice. We therefore investigated a dosing schedule of one administration of
monoHER just before doxorubicin. The electrocardiogram was measured
telemetrically in mice after the combined treatment of doxorubicin (4 mg/kg,
i.v.) with one dose of monoHER (500 mg/kg, i.p., administered 1 h before
doxorubicin) for 6 weeks. These data were compared with the five times/week
schedule (500 mg/kg, i.p., administered 1 h before doxorubicin and every 24 h for
4 days). The increase of the ST interval was used as a measure for
cardiotoxicity. It was shown that 500 mg/kg monoHER administered only 1 h before
doxorubicin provided complete protection against the cardiotoxicity. This
protection was present for at least 10 weeks after the last treatment. Because of
the short half-life of monoHER, these results suggest that the presence of
monoHER is only necessary during the highest plasma levels of doxorubicin.
PMID- 10778961
TI - Altered pharmacokinetics and metabolism of CPT-11 in liver dysfunction: a need
for guidelines.
AB - Metabolic conversion of CPT-11 is a major route of elimination of this new
topoisomerase 1 inhibitor. Presently, recommendations for dose adjustments of CPT
11 in patients with liver dysfunction are lacking. We describe the case of a
patient with metastatic colon cancer with liver dysfunction treated with CPT-11
at two different dose levels (100 mg/m2 and 30 mg/m2, single dose, administered
as a 90-min i.v. infusion). The lactones and carboxylates of CPT-11 and SN-38
were determined by high-performance liquid chromatography. SN-38 glucuronide was
determined after deglucuronidation. The procedures allowed intrapatient
comparison of pharmacokinetics and metabolism of the drug. Severe side effects
were encountered, which could be explained by the reduced clearance of CPT-11 and
its metabolites. These included neutropenic fever with culture-proven septicemia,
thrombocytopenia, somnolence, diarrhea, and signs and symptoms of transient
hepatic failure. Our findings offer important data for the further development of
guidelines for dose reduction of CPT-11 in patients with liver dysfunction.
PMID- 10778962
TI - Delayed-type hypersensitivity response is a predictor of peripheral blood T-cell
immunity after HER-2/neu peptide immunization.
AB - Many groups that immunize cancer patients with cancer vaccines use the generation
of a delayed-type hypersensitivity (DTH) response as the primary measure of the
ability to immunize a patient to a tumor cell or specific tumor antigen. This
study examines whether the development of a tumor antigen-specific DTH response,
measured after vaccination with peptide-based vaccines, correlates to in vitro
assessment of peripheral blood antigen-specific T-cell responses. The HER-2/neu
protein was used as a model tumor antigen. Thirty-two patients who completed a
course of immunization with HER-2/neu peptide-based vaccines were analyzed. HER
2/neu peptide-specific DTH responses (n = 93) and peripheral blood T-cell
responses (n = 93) were measured 30 days after the final immunization. Size of
DTH induration was correlated with HER-2/neu-specific T-cell proliferative
responses assessed from peripheral blood lymphocytes isolated concurrently with
peptide skin test placement. HER-2/neu peptide-specific DTH responses > or =10
mm2 correlated significantly to a measurable peptide-specific peripheral blood T
cell response defined as stimulation index >2.0 (P = 0.0006). However, antigen
specific DTH responses with magnitudes between 5 and 9 mm2 were not significantly
associated with the development of systemic immunity. DTH responses between 5 and
9 mm2 carried an odds ratio of 1.3 (P = 0.61) in predicting a measurable systemic
tumor antigen response. The findings presented here demonstrate that tumor
antigen-specific DTH responses > or =10 mm2 correlate with measurable in vitro
antigen-specific lymphocytic proliferation and are, in this model system, a
reflection of systemic immunization.
PMID- 10778963
TI - Spontaneous apoptosis of CD8+ T lymphocytes in peripheral blood of patients with
advanced melanoma.
AB - Peripheral blood mononuclear cells (PBMCs) obtained from patients with advanced
melanoma but not from healthy individuals were found to undergo spontaneous ex
vivo apoptosis upon incubation in medium. PBMCs were evaluated for evidence of
apoptosis using Annexin V binding, caspase-3 activation, and DNA fragmentation
(terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling). PBMCs of
patients with melanoma contained a significantly higher proportion (P = 0.0027)
of spontaneously apoptotic cells than PBMCs of controls after 24-h incubation in
medium alone. The relative proportion of activated Fas+ and tumor necrosis factor
receptor 1-positive (TNFR1+) PBMCs was significantly higher in patients with
melanoma than that observed in controls. To demonstrate that the TNF family of
receptors and ligands was involved in this type of apoptosis, PBMCs were
incubated in the presence of agonistic anti-Fas antibody (CH-11) or TNF-alpha.
The proportion of terminal deoxynucleotidyl transferase-mediated dUTP nick end
labeling-positive PBMCs undergoing spontaneous apoptosis was found to be
comparable with that induced by CH-11 antibody or TNF-alpha. Three-color flow
cytometry revealed that CD3+ Fas+ T cells were especially sensitive to apoptosis
and were preprogrammed in vivo to die. Apoptosis occurred in all subsets of PBMCs
but was significantly higher (P = 0.01) in the CD3+ CD8+ T-cell subset in
patients relative to controls. In two patients with melanoma, who responded
clinically to dendritic cell-based peptide vaccines, the proportion of apoptotic
T cells was decreased by half after therapy. In patients who were treated
previously with vaccination-based therapies, levels of T-cell apoptosis were
lower than in the other melanoma patients. The observed accelerated death of T
cells, which are activated and susceptible to apoptosis in patients with
melanoma, may contribute to a rapid turnover of immune cells, resulting in a
decreased immunocompetence.
PMID- 10778964
TI - The orally administered P-glycoprotein inhibitor R101933 does not alter the
plasma pharmacokinetics of docetaxel.
AB - This Phase I study was performed to assess the feasibility of combining docetaxel
with the new P-glycoprotein inhibitor R101933 and to determine the dose limiting
toxicity of this combination. Fifteen patients received oral R101933 alone at a
dose escalated from 200 to 300 mg twice daily (b.i.d.; cycle 0), an escalating
i.v. dose of docetaxel (60, 75, and 100 mg/m2) as a 1-h infusion (cycle 1), and
the combination (cycle 2 and further). Dose limiting toxicity consisting of
mucositis and neutropenic fever was reached at the combination of docetaxel, 100
mg/m2, and R101933, 300 mg b.i.d., and the maximum tolerated dose was established
at docetaxel, 100 mg/m2, and R101933, 200 mg b.i.d. Plasma concentrations of
R101933 achieved in patients were in the same range as required in preclinical
rodent models to overcome paclitaxel resistance. The plasma pharmacokinetics of
docetaxel were not influenced by the R101933 regimen at any dose level tested, as
indicated by plasma clearance values of 26.5 +/- 7.78 liters/h/m2 and 23.4 +/-
4.52 liters/h/m2 (P = 0.15) in cycles 1 and 2, respectively. These findings
indicate that the contribution of a P-glycoprotein inhibitor to the activity of
anticancer chemotherapy can now be assessed in patients for the first time
independent of its effect on drug pharmacokinetics.
PMID- 10778965
TI - Definition and refinement of chromosome 8p regions of loss of heterozygosity in
gastric cancer.
AB - Loss of heterozygosity at several chromosomal loci is a common feature of the
malignant progression of human tumors. These regions are thought to harbor one or
more putative tumor suppressor gene(s) playing a role in tumor development.
Allelic losses on the short arm of chromosome 8 (8p) have been reported as
frequent events in several cancers, and three commonly deleted regions have been
defined at 8p11.2-12, 8p21-22, and 8p23.1. To evaluate the possible involvement
of these regions in gastric cancer, we used eight microsatellite markers to
perform an extensive analysis of allele loss at 8p21-22 in 52 cases of primary
gastric adenocarcinoma. We found that 44% of tumors showed allelic loss for at
least one marker at 8p21-22. The critical region of loss was found to be between
markers LPL and D8S258, which displayed loss of heterozygosity in 39% and 33% of
cases, respectively. This region is centromeric to the LPL locus and centered on
the D8S258 locus. We conclude that 8p22 deletion is a frequent event in gastric
cancer and suggest the presence of a putative tumor suppressor gene near the
D8S258 locus. Initial steps were taken toward the identification of this gene,
which is likely to play an important role in the pathogenesis of gastric cancer
and of other tumors as well.
PMID- 10778966
TI - Thymidylate synthase expression: an independent prognostic factor for local
recurrence, distant metastasis, disease-free and overall survival in rectal
cancer.
AB - Several studies have suggested that the intratumoral level of thymidylate
synthase (TS) in colorectal tumors correlates with survival. We have studied the
correlation between TS expression in primary rectal cancer and locoregional
recurrence, distant metastases, and survival. TS enzyme levels were evaluated
immunohistochemically using the specific monoclonal antibody TS 106 in paraffin
embedded tumors from 243 patients who had undergone primary surgery for rectal
cancer during the years 1980-1993. All patients were included in prospective
randomized trials aimed at determining the clinical value of a short preoperative
course of local radiation therapy (five doses of 5 Gy each). With a median follow
up of 94 months (range, 43-202 months), it was observed by multivariate analysis
that Dukes' stage and TS expression were independent prognostic markers of
locoregional recurrence (P < 0.001 and P = 0.038, respectively) distant
metastasis (P < 0.001 and P = 0.011, respectively) disease-free survival (P <
0.001 and 0.014, respectively), and overall survival (P < 0.001 and 0.020,
respectively). By multivariate analysis, preoperative irradiation therapy showed
a borderline improvement in locoregional recurrence (P = 0.051). No other
factors, such as age, sex, differentiation of the tumor, or p53 expression, were
noted to be independent prognostic factors for clinical outcome in these
patients. We concluded that the intratumoral expression of TS in primary rectal
cancer is an independent prognostic factor for locoregional recurrence, distant
metastases, disease-free survival, and overall survival. Patients with low
intratumoral TS expression had a significantly better outcome than those with
high TS expression.
PMID- 10778967
TI - Marked increase of trypsin(ogen) in serum of linitis plastica (gastric cancer,
borrmann 4) patients.
AB - Linitis plastica, or Borrmann 4 gastric cancer, shows very poor prognosis, and
the reason has not been understood. In the present study, we examined serum
levels of trypsin(ogen) in 44 gastric cancer patients, including 17 early gastric
cancer, 18 non-Borrmann 4 advanced gastric cancer, and 9 Borrmann 4 gastric
cancer, by using the RIA gnost Trypsin kit (Hoechst Japan, Tokyo, Japan), which
was expected to detect trypsin-1, trypsin-2, trypsinogen-1, and trypsinogen-2 in
sera. The trypsin(ogen) concentration was much higher in the patients with
linitis plastica than in the other gross types of gastric cancer.
Hypertrypsinemia was identified in approximately 60% of advanced gastric cancer
cases. Lymph node involvement, liver metastasis, or poorly differentiated
adenocarcinoma is an important factor of hypertrypsinemia. The serum
trypsin(ogen) level in linitis plastica patients was 3484.4 +/- 2319.7 ng/ml
(mean +/- SD), which was significantly higher not only than that of the early
gastric cancer (384.1 +/- 92.1) but also the stage IV gastric cancer patients
(578 +/- 440.4), excluding those with linitis plastica. The elevated serum
trypsinogen level in linitis plastica patients may be related to the malignant
behavior of this type of cancer cell. Serum trypsin(ogen) of linitis plastica
shows significantly higher concentrations than do the other types of advanced
gastric cancer. Therefore, serum concentration of trypsin(ogen) might be a good
marker of gastric cancer of linitis plastica.
PMID- 10778968
TI - Concentrations of galectin-3 in the sera of normal controls and cancer patients.
AB - Galectin-3, a member of the beta-galactoside-binding animal lectins, has been
implicated in tumor invasion and metastasis. Using an immunoligand assay, we
assessed the circulating levels of galectin-3 in sera from cancer patients as
well as from healthy controls. Low serum levels of galectin-3 were detected in
healthy individuals (median, 62 ng/ml; range, 20-313 ng/ml; 95th percentile,
184.3 ng/ml). Compared with healthy individuals, galectin-3 serum levels in
patients with breast, gastrointestinal, lung, or ovarian cancer, melanoma, and
non-Hodgkin's lymphoma were significantly elevated (P = 0.014). Moreover,
galectin-3 concentrations in sera from patients with metastatic disease were
higher than in sera from patients with localized tumors. Maximum serum
concentrations of galectin-3 (median, 320 ng/ml; range, 20-950 ng/ml) were found
in patients with metastatic gastrointestinal carcinoma. These results suggest
that circulating galectin-3 may play a role in tumor progression. The possibility
of using this assay in early-stage cancer to predict metastasis should be
studied.
PMID- 10778969
TI - Overexpression of the hOGG1 gene and high 8-hydroxy-2'-deoxyguanosine (8-OHdG)
lyase activity in human colorectal carcinoma: regulation mechanism of the 8-OHdG
level in DNA.
AB - 8-Hydroxy-2'-deoxyguanosine (8-OHdG) is one of the most abundant oxidatively
modified lesions in DNA. Our previous study (Kondo et al, Free Radic. Biol. Med.,
27: 401-410, 1999) revealed that human colorectal carcinoma cells are oxidatively
stressed based on 8-OHdG determination. To elucidate 8-OHdG metabolism and its
clinical significance in colorectal carcinoma, we studied the 8-OHdG repair
system in DNA by measuring specific lyase activity and hOGG1 expression using
quantitative-competitive reverse transcription-PCR. In addition, we searched for
the presence of mutations and single nucleotide polymorphisms of the hOGG1 gene
by single-strand conformational polymorphism and sequencing analyses. It was
found that 8-OHdG-specific lyase activity and hOGG1 expression were significantly
up-regulated in carcinoma, and a proportional association between 8-OHdG levels
and either 8-OHdG lyase activity (r = 0.641, P < 0.05) or hOGG1 expression (r =
0.702, P < 0.05) was present. Whereas no difference was detected in the 8-OHdG
level between early- and advanced-stage cancer, lyase activity (1.2-fold) and
hOG1 expression (1.6-fold) were significantly increased in advanced-stage cancer.
No mutation was found in the 25 tumors examined. Three kinds of single nucleotide
polymor. phism were observed, including that of codon 326 (Ser/Cys) in exon 7.
However, there was no correlation between any of the three polymorphic patterns
and either 8-OHdG level or lyase activity. These results suggest that increased 8
OHdG levels in colorectal carcinoma are attributed to increased formation and are
maintained by induced 8-OHdG repair activity at appropriate high levels. Our
results may offer a unique approach in the development of preventive and
therapeutic interventions as well as new insights into the pathogenesis of
colorectal carcinoma.
PMID- 10778970
TI - BAX and PKCalpha modulate the prognostic impact of BCL2 expression in acute
myelogenous leukemia.
AB - Previously, we demonstrated that the level of BCL2 expression is prognostic in
acute myelogenous leukemia (AML). High levels of BCL2 correlate with an adverse
outcome when associated with favorable and intermediate prognosis cytogenetics
(FIPC), whereas low levels portend an adverse outcome when associated with
unfavorable cytogenetics (UC). Because BCL2 function can be modulated by
dimerization with family members, like BAX, or by phosphorylation by protein
kinase C alpha (PKCalpha), we hypothesize that the relative expression of these
proteins in primary leukemic cells might alter the prognostic impact of BCL2
expression. We therefore measured BAX and PKCalpha protein levels in peripheral
blood mononuclear cell lysates from 165 newly diagnosed AML patients and
correlated the expression of these proteins with BCL2 expression, patient
survival, and remission induction success. Expression levels of BAX and PKCalpha
were normalized against a control cell line, K562. BAX and PKCalpha expression
levels were heterogeneous and did not correlate with the percentage of blasts in
the sample (R2 = 0.01 and <0.01). The median expression of both was similar
across FAB groups but the range was greater for M4. A similar distribution of
expression was observed in all cytogenetic groups, except that patients with
inversion 16 demonstrated lower levels of BAX. Individually, neither PKCalpha nor
BAX expression was prognostic of response to induction therapy or survival. A
similar outcome was obtained when patients were stratified by cytogenetics into
FIPC and UC groups. However, the ratio of either BCL2:BAX (B2:BX) or
PKCalpha*B2:BX (PK*B2:BX) was highly prognostic. Patients with FIPC and a lower
ratio (less than median) of either B2:BX or PK*B2:BX had a significantly higher
remission induction rate (88 versus 69%, P = 0.04) and longer survival (median:
141 versus 80.5 weeks, P = 0.007) compared with those with ratios more than
median. For patients with UC, values of either B2:BX or PK*B2:BX below the median
had an inferior response rate to induction therapy (35 versus 78%, P = 0.0006)
and inferior survival outcomes (median survival: 11 versus 53 weeks, P =
0.00002). Interestingly, FIPC and UC patients with antiapoptotic ratios (defined
as B2:BX or PK*B2:BX more than median) had identical response rates and survival
outcomes. In multivariate analyses, the compound variables of cytogenetics and
B2:BX, or PK*B2:BX were independent predictors of survival. These results suggest
that expression levels of proteins that affect the functional status of BCL2
modify the prognostic impact of BCL2 and suggest that the role of apoptosis in
different cases of AML varies independently in the different cytogenetic
subgroups.
PMID- 10778971
TI - Allelic loss and microsatellite alterations of chromosome 3p14.2 are more
frequent in recurrent cervical dysplasias.
AB - Epidemiological studies have documented the unpredictable clinical progression or
recurrence of cervical dysplasia. Recent studies have shown several molecular
changes in cervical cancers and their associated dysplasia. We conducted
molecular analyses on a retrospectively ascertained cohort of recurrent and
nonrecurrent cervical dysplasia cases in an attempt to define molecular
biomarkers to predict progressive or recurrent disease. Cases were chosen if long
term follow-up (3-5 years after conization) and biopsy confirmation were
available. Paraffin-embedded, postconization cervical tissues from 19 recurrent
and 18 nonrecurrent dysplasias were analyzed. Human papillomavirus (HPV) was
identified by PCR for general and type-specific (HPV-16 and HPV-18) primers.
Allelotyping analysis was performed by multiplex PCR using a panel of 16
microsatellite markers targeting putative tumor suppressor gene regions on
chromosomes 3p, 5p, 6p, 9p, 11q, and 17p. The overall rate of HPV infection was
similar in both groups. In the allelotyping analysis, loss of heterozygosity at
the fragile histidine triad region in 3p14.2 was significantly higher in the
recurrent group than in the nonrecurrent group (P = 0.005). Furthermore,
microsatellite alterations (MAs) were more frequent in the recurrent group (mean
MA index, 0.254) as compared with the nonrecurrent group (mean MA index, 0.085; P
= 0.0025). These findings suggest that HPV status alone does not predict
recurrence and that loss of heterozygos. ity at the fragile histidine triad
region may represent a potential biomarker in predicting recurrence. Frequent MAs
in the recurrent group may represent an underlying genomic instability that
creates susceptibility for allelic loss, thus increasing the risk for recurrence
or progression.
PMID- 10778972
TI - Analysis of MLH1 and MSH2 expression in ovarian cancer before and after platinum
drug-based chemotherapy.
AB - Preclinical studies have demonstrated a relationship between DNA mismatch repair
(MMR) status and sensitivity to cisplatin and carboplatin. MMR-deficient cells
are resistant to both drugs, and selection for cisplatin resistance in vitro is
sometimes accompanied by loss of MMR protein expression. We used
immunohistochemical staining techniques to investigate hMLH1 and hMSH2 expression
in paired ovarian tumor sections from 54 ovarian cancer patients before and after
platinum-based therapy. We sought associations between hMLH1 and hMSH2 protein
expression and clinical parameters known to be of prognostic significance as well
as response to treatment and overall survival. hMLH1 and hMSH2 staining decreased
significantly after platinum-based therapy. The percent of malignant cells that
stained positive correlated with the intensity of nuclear staining for both
proteins; staining for hMLH1 correlated well with staining for hMSH2.
Unexpectedly, expression of nuclear hMLH1 correlated negatively with response to
treatment. Expression of nuclear hMLH1 and hMSH2 was positively correlated with
pretreatment CA125 level, and expression of nuclear hMSH2 was positively
correlated with change in CA125 level after treatment. Tumor stage was associated
with expression of nuclear hMSH2, and tumor histological subtype was associated
with both hMLH1 and hMSH2 staining. No association was found between expression
of either protein and overall survival. These results indicate that the tumor is
biologically altered after chemotherapy consistent with treatment-induced
selection for cells expressing lower hMLH1 and hMSH2 levels. However,
immunohistochemical staining for either hMLH1 or hMSH2 was not highly predictive
of drug sensitivity as measured by response or survival.
PMID- 10778973
TI - A large 6q deletion is a common cytogenetic alteration in fibroadenomas, pre
malignant lesions, and carcinomas of the breast.
AB - To assess whether early breast lesions are the precursors of invasive carcinomas,
three classes of breast lesions, namely benign tumors (including fibroadenomas),
putative premalignant lesions (including cases of atypical hyperplasia), and
invasive carcinomas, were compared at the cytogenetic and molecular cytogenetic
levels. Genetic relatedness was clearly demonstrated by the sharing of several
anomalies, among which 6q deletions outnumbered all of the other alterations
detected. Indeed, deletions of the long arm of chromosome 6, most likely
occurring in epithelial cells, were present in 83.9% of benign breast tumors, 64%
of putative premalignant lesions, and 77.4% of analyzable carcinomas.
Furthermore, the interval between 6q24 and qter appeared to be the common region
of deletion in all three classes of breast lesions, whereas the minimal common
region of deletion was 6q27-qter. Interestingly, the latter region was reported
previously to be deleted in benign ovarian tumors and recently found to harbor a
gene (SEN6) that is important for SV40-mediated immortalization of human cells.
PMID- 10778974
TI - CpG island arrays: an application toward deciphering epigenetic signatures of
breast cancer.
AB - CpG island hypermethylation is a frequent epigenetic event in cancer. We have
recently developed an array-based method, called differential methylation
hybridization (DMH), allowing for a genome-wide screening of CpG island
hypermethylation in breast cancer cell lines (T. H-M. Huang et al., Hum. Mol.
Genet., 8: 459-470, 1999). In the present study, DMH was applied to screen 28
paired primary breast tumor and normal samples and to determine whether patterns
of specific epigenetic alterations correlate with pathological parameters in the
patients analyzed. Amplicons, representing a pool of methylated CpG DNA derived
from these samples, were used as hybridization probes in an array panel
containing 1104 CpG island tags. Close to 9% of these tags exhibited extensive
hypermethylation in the majority of breast tumors relative to their normal
controls, whereas others had little or no detectable changes. Pattern analysis in
a subset of CpG island tags revealed that CpG island hypermethylation is
associated with histological grades of breast tumors. Poorly differentiated
tumors appeared to exhibit more hypermethylated CpG islands than their moderately
or well-differentiated counterparts (P = 0.041). This early finding lays the
groundwork for a population-based DMH study and demonstrates the need to develop
a database for examining large-scale methylation data and for associating
specific epigenetic signatures with clinical parameters in breast cancer.
PMID- 10778975
TI - Detection of circulating tumor cells in carcinoma patients by a novel epidermal
growth factor receptor reverse transcription-PCR assay.
AB - The epidermal growth factor receptor (EGFR) is overexpressed in 50-70% of human
primary breast, lung, and colon carcinomas, whereas it is not usually expressed
in hematopoietic cells. We developed a novel reverse transcription-PCR (RT-PCR)
Southern blot assay for the detection of circulating, EGFR mRNA-expressing tumor
cells in carcinoma patients. The assay was set up by increasing the amount of
cDNA step by step in the PCR reaction. The highest sensitivity and specificity
were found when using 800 ng of cDNA in the PCR reaction. Peripheral blood
samples from 91 patients with either colon (38), lung (30), or breast (23)
carcinomas and from 38 healthy volunteers were analyzed. EGFR transcripts were
found in 44 of 75 (59%) patients with metastatic carcinoma and in 4 of 38 (10.5%)
healthy donors (P < 0.001; chi2 test). The expression of EGFR, cytokeratin 19,
and carcinoembryonic antigen mRNA in blood samples from patients with metastatic
colon carcinoma was compared. EGFR, cytokeratin 19, and carcinoembryonic antigen
transcripts were found in 8 of 11 (73%), 3 of 11 (27%), and 5 of 11 (45%)
patients, respectively. Furthermore, two of seven (29%) Dukes' B and five of nine
(55%) Dukes' C colon carcinoma patients were found to express EGFR mRNA in the
peripheral blood. All patients that expressed EGFR transcripts in the peripheral
blood were found to express the EGFR protein in the corresponding primary
carcinoma, as assessed by immunohistochemistry. These data suggest that the EGFR
assay that we developed is a highly specific and sensitive technique to detect
circulating tumor cells in patients affected by different carcinoma types.
PMID- 10778976
TI - Clinical significance of serum soluble interleukin 2 receptor-alpha in esophageal
squamous cell carcinoma.
AB - Although the serum level of soluble interleukin-2 receptor alpha (sIL-2Ralpha)
has been shown to correlate with progression and prognosis of several cancers,
data to support its clinical significance to esophageal squamous cell carcinoma
(ESCC) are limited. This study was conducted to assess the prognostic value and
source of sIL-2Ralpha in patients with ESCC. From January 1986 to June 1997, 125
patients with histopathologically confirmed ESCC were enrolled for study. Ninety
three patients underwent en bloc esophagectomy, and 32 patients with unresectable
tumor underwent palliative surgery. Four (4.3%; 4 of 93) patients died of
surgical complications. Serum levels of sIL-2Ralpha were measured by ELISA.
Expression of IL-2Ralpha, IL-2Rbeta, and IL-2Rgamma in the pathological section
was determined, respectively, by immunohistochemistry (IHC) and in situ
hybridization (ISH). Compared with the healthy control group (1020 +/-476 pg/ml,
n = 103), ESCC patients tended to have significantly higher serum sIL-2Ralpha
concentrations (1424 +/- 798 pg/ml, n = 121). The sIL-2Ralpha level was
correlated with age, Tumor-Node-Metastasis classification, tumor stage, reading
score of the IHC staining, and survival but not with the pathological grade or
lymphovascular invasion. Prognosis was worse for patients with high sIL-2Ralpha
levels (> or =1500 pg/ml) than for those with low serum sIL-2Ralpha levels (<
1500 pg/ml; P = 0.0209). It can be used as an independent prognostic factor of
ESCC. In the pathological sections, expression of IL-2Ralpha, IL-2Rbeta, and IL
2Rgamma was detected in 17 (18.1%), 83 (89.2%), and 83 (89.2%) cases,
respectively, by IHC, and the message of IL-2Ralpha was identified in tumor cells
by ISH in 30.1% (28 of 93) of the cases. Serum concentrations of sIL-2Ralpha are
frequently elevated in ESCC patients and are correlated with disease progression
and survival. These data indicate that, in addition to activated T cells, cancer
cells could be an important source of sIL-2Ralpha in ESCC patients.
PMID- 10778977
TI - A novel approach for nasopharyngeal carcinoma treatment uses phenylbutyrate as a
protein kinase C modulator: implications for radiosensitization and EBV-targeted
therapy.
AB - Sodium phenylbutyrate (NaPB) represent a new non-toxic class of compounds with
antiproliferative activities to different tumors and has been shown to modulate
many gene expressions by inhibiting histone deacetylation and DNA methylation as
the major mechanism. Butyrate and other protein kinase C (PKC) activators have
been reported to be able to activate virus enzymes. The present work investigates
whether NaPB has an antiproliferative effect or modulatory effects on EBV
associated nasopharyngeal carcinoma (NPC) and whether EBV thymidine kinase gene
can be activated to make cells susceptible to ganciclovir (GCV) therapy. NaPB
treatment displayed a dose- and time-dependent antiproliferative effect on the
NPC cell line CNE2. Cell cycle analysis revealed an inhibitory effect of NaPB on
G1-S-phase progression. Shortly after NaPB treatment, we found that PKC activity
was activated rapidly but also decreased rapidly. Down-regulation of PKC-alpha
and translocation of PKC-alpha from the cytosol to membrane were seen by Western
blot. The decrease in PKC activity by NaPB corresponds to an enhanced response to
radiation on CEN2 cells. Moreover, NaPB up-regulated EBV thymidine kinase
activity to render EBV-associated Daudi cells susceptible to killing by GCV.
Based on the observations of NaPB as a PKC modulator, the combination of NaPB,
GCV, and radiation may provide a potential novel approach for treatment of EBV
associated NPC.
PMID- 10778978
TI - High avidity melanoma-reactive cytotoxic T lymphocytes are efficiently induced
from peripheral blood lymphocytes on stimulation by peptide-pulsed melanoma
cells.
AB - To design an efficient procedure to expand high avidity melanoma reactive T cells
and to perform immunotherapies, we compared conditions of peripheral blood
lymphocyte (PBL) stimulation by Melan-A/MART-1 peptides. Avidity of induced CTLs
was evaluated by measuring their lysis and cytokine secretion to peptide-pulsed
transporter-associated protein-deficient cells and to melanoma cells. In side-by
side experiments, we show that melanoma cells, either allogeneic or autologous,
induced the growth of high avidity Melan-A-reactive CTLs from all donors, whereas
essentially low avidity T cells were induced by peptide-pulsed PBLs. We also show
that at least two cytokines, interleukin-6 and interleukin-2, were required to
promote the growth of high avidity CTLs. Once sorted by tetramer labeling or
cloning, the specificity and reactivity to tumor cells of peptide-specific T
cells induced by allogeneic melanoma cells were confirmed. We then describe a
relatively simple and efficient procedure that allowed us to obtain
systematically high amounts (in the range of billion) of high avidity Melan-A/
MART-1-specific T cells from the PBLs of HLA-A2 melanoma patients and healthy
donors in 3 months. Because this antigen is expressed by most melanoma tumors,
this procedure should be useful for checking the efficiency of adoptive
immunotherapy of melanoma tumors and using functionally well-defined Melan-A/MART
1-specific CTLs in a large group of patients.
PMID- 10778979
TI - Preclinical toxicity and efficacy study of a 14-day schedule of oral 5-iodo-2
pyrimidinone-2'-deoxyribose as a prodrug for 5-iodo-2'-deoxyuridine
radiosensitization in U251 human glioblastoma xenografts.
AB - In anticipation of an initial clinical Phase I trial in patients with high-grade
gliomas of p.o. administered 5-iodo2-pyrimidinone-2'-deoxyribose (IPdR) given
daily for 14 days as a prodrug for 5-iodo-2'-deoxyuridine (IUdR)-mediated tumor
radiosensitization, we determined the systemic toxicities and the percentage IUdR
DNA incorporation in normal athymic mouse tissues and a human glioblastoma
xenograft (U251) after this dosing schedule of IPdR. Using a tumor regrowth assay
of s.c. U251 xenografts, we also compared radiosensitization with this IPdR
dosing schedule to radiation therapy (XRT) alone (2 Gy/day for 4 days) or to XRT
after continuous infusion IUdR for 14 days at the maximum tolerated dose in mice
(100 mg/kg/day). Athymic mice with and without U251 s.c. xenografts tolerated 750
or 1500 mg/kg/day of p.o. IPdR (using gastric lavage) for 14 days without weight
loss or activity level changes during treatment and for a 28-day posttreatment
observation period. The percentage IUdR-DNA incorporation in U251 tumor cells was
significantly higher after p.o. IPdR (750 and 1500 mg/kg/day) for 14 days (3.1 +/
0.2% and 3.7 +/- 0.3%, respectively) than continuous infusion IUdR for 14 days
(1.4 +/- 0.1%). Compared to XRT alone, a significant sensitizer enhancement ratio
(SER) was found with the combination of p.o. IPdR (1500 mg/kg/d) + XRT (SER =
1.31; P = 0.05) but not for the combination of continuous infusion IUdR + XRT
(SER = 1.07; P = 0.57) in the U251 xenografts. The percentage IUdR-DNA
incorporation after IPdR at 1500 mg/kg/day for 14 days in normal bone marrow,
normal small intestine, and normal liver were 1.2 +/-0.2%, 3.3 +/- 0.3%, and 0.2
+/- 0.1%, respectively. We conclude that a 14-day p.o. schedule of IPdR at up to
1500 mg/kg/day results in no significant systemic toxicity in athymic mice and is
associated with significant radiosensitization using this human glioblastoma
multiforme xenograft model. Based on these data and our previously published data
using shorter IPdR dosing schedules, which also demonstrate an improved
therapeutic index for IPdR compared to IUdR, an initial clinical Phase I and
pharmacokinetic study of p.o. IPdR daily for 14 days is being designed.
PMID- 10778980
TI - Cytotoxic activity of disulfide-stabilized recombinant immunotoxin RFB4(dsFv)
PE38 (BL22) toward fresh malignant cells from patients with B-cell leukemias.
AB - Chemical conjugates of anti-CD22 monoclonal antibodies and toxins have been used
to treat CD22+ hematological malignancies. A new anti-CD22 recombinant
immunotoxin RFB4(dsFv)-PE38, composed of the Fv portion of the monoclonal
antibody RFB4 fused to a truncated form of Pseudomonas exotoxin A, is being
developed to target CD22+ tumor cells. To explore the potential clinical utility
of this recombinant toxin in treating patients with B-cell malignancies, the
fresh cells of patients were incubated ex vivo with RFB4(dsFv)-PE38. Specific
cytotoxicity was demonstrated in the malignant cells of 25 of 28 patients with a
variety of B-cell malignancies, including acute and chronic lymphocytic leukemias
and large cell, mantle cell, and follicular lymphomas. The IC50S, the
concentrations necessary for 50% inhibition of protein synthesis, were 3-10 ng/ml
in five patients and 10-50 ng/ml in seven patients. Cytotoxicity correlated with
cell death upon direct examination of the malignant cells. Significant
cytotoxicity was observed with cells containing as few as 350 CD22 sites/cell. A
more active derivative of RFB4(dsFv)-PE38, RFB4(dsFv)-PE38KDEL, was produced and
was slightly to more than 10-fold more cytotoxic toward patient cells and about
twice as toxic to mice. Thus, RFB4(dsFv)-PE38 was specifically cytotoxic toward
malignant cells from patients with B-cell leukemias. These data support the
testing of RFB4(dsFv)-PE38 in patients with CD22+ leukemias and lymphomas, which
is presently under way.
PMID- 10778981
TI - Differential cytotoxic pathways of topoisomerase I and II anticancer agents after
overexpression of the E2F-1/DP-1 transcription factor complex.
AB - The transcription factor complex E2F-1/DP-1 regulates the G1-to-S-phase
transition and has been associated with sensitivity to the S-phase-specific
anticancer agents camptothecin and etoposide, which poison DNA topoisomerase I
and II, respectively. To investigate the relationship between E2F-1 and drug
sensitivity in detail, we established human osteosarcoma U-20S-TA cells
expressing full-length E2F-1/ DP-1 under the control of a tetracycline-responsive
promoter, designated UE1DP-1 cells. Topoisomerase I levels and activity as well
as the number of camptothecin-induced DNA single- and double-strand breaks were
unchanged in UEIDP-1/tc- cells with >10-fold E2F-1/DP-1 overexpression. However,
UE1DP-1/tc- cells were hypersensitive to camptothecin in both a clonogenic assay
and four different apoptotic assays. This indicates that camptothecin-induced
toxicity in this model is due to the activation of an E2F-1/ DP-1-induced post
DNA damage pathway rather than an increase in the number of replication forks
caused by the S-phase initiation. In contrast, topoisomerase IIalpha levels (but
not topoisomerase IIbeta levels), together with topoisomerase IIalpha promoter
activity, increased 2--3-fold in UE1DP-1/tc-cells. Furthermore, the number of
etoposide-induced DNA single- and double-strand breaks increased in UE1DP-1/tc
cells together with a rise in clonogenic sensitivity to etoposide, but an equal
apoptotic sensitivity to etoposide. The increase in topoisomerase IIalpha
promoter activity in UE1DP-1/tc--cells was shown to be due to S-phase initiation
per se because it was blocked by ectopic expression of dominant negative cyclin
dependent kinase 2. In conclusion, overexpression of E2F-1/DP-1 in U-20S-TA cells
is sufficient to increase clonogenic sensitivity to both topoisomerase I- and II
targeted anticancer drugs. However, the mechanism by which this occurs appears to
be qualitatively different. The UE1DP-1 cell model may be used to elucidate post
DNA damage mechanisms of cell death induced by topoisomerase I-directed
anticancer agents.
PMID- 10778982
TI - The in vivo effect of bryostatin-1 on paclitaxel-induced tumor growth, mitotic
entry, and blood flow.
AB - Pretreatment of tumor cells with the protein kinase C (PKC) inhibitor bryostatin
1 enhances the cytotoxicity of most chemotherapeutic agents. However, in the case
of paclitaxel, this effect has been shown in vitro to be best achieved when
bryostatin-1 follows (rather than precedes) paclitaxel treatment. With
combination trials of bryostatin-1 and paclitaxel planned for clinical trials and
with only in vitro data available regarding drug sequence, we elected to
undertake an in vivo study evaluating the effect of sequential bryostatin-1 and
paclitaxel in a tumor-bearing mouse model and to correlate this effect to cell
cycle events, tumor metabolism, and tumor blood flow. At the maximum tolerated
i.p. dose, bryostatin-1 at 80 microg/kg resulted in a small but significant
increase in tumor doubling time (4.2 +/- 0.3 days) compared with control tumors
(3.0 +/- 0.3 days; P < 0.01). Mice treated with i.v. paclitaxel, administered at
a dose of 12 mg/kg every 12 h for three doses, weekly for 3 weeks, had a tumor
doubling time of 23.4 +/- 1.7 days. Mice pretreated with i.p. bryostatin-1 (80
microg/kg) followed 12 h later by i.v. paclitaxel (12 mg/kg every 12h for three
doses) weekly for 3 weeks had a tumor doubling time of 9.7 +/- 1.1 days. This was
significantly less (P < .001) than paclitaxel alone, which indicated an
inhibitory effect by bryostatin-1 on paclitaxel therapy. In comparison, tumor
bearing mice that were treated with the same dose but with the sequence of
paclitaxel followed by bryostatin-1 had a tumor doubling time of 29.6 +/- 0.6
days. This was significantly greater than the tumor doubling times for any
condition tested (P < 0.01), demonstrating the sequence dependence of this
combination. The efficacy of paclitaxel is dependent on mitotic entry, a step
that requires activation of p34cdc2 kinase activity. Treatment with paclitaxel in
vivo increased p34 cdc2 kinase activity in the mouse mammary tumors, whereas
administration of bryostatin-1 before paclitaxel prevented the p34cdc2 kinase
activation by paclitaxel. This was further evaluated in vitro by flow cytometry
in MKN-74 human gastric cancer cells. As determined by MPM-2 labeling, which
identifies cells in mitosis, pretreatment with bryostatin-1 prevented paclitaxel
treated cells from entering mitosis. Bryostatin-1 has been reported to induce
changes in muscle metabolism and to decrease muscle blood flow. These events
could impact on the interaction of bryostatin-1 with paclitaxel. Using proton
decoupled phosphorus nuclear magnetic resonance (31P-NMR) spectroscopy in vivo,
bryostatin-1 at 80 micro1g/kg induced a decrease in both intratumoral pH and high
energy phosphates. In vivo perfusion studies, using dynamic enhanced NMR imaging
with gadolinium diethylenetriamine pentaacetic acid, also demonstrated decreased
tumor blood flow. These studies suggest that the inhibition of tumor response to
paclitaxel by bryostatin-1 is multifactorial and includes such diverse factors as
inhibition of cell entry into mitosis, a decrease in pH and energy metabolism,
and a decrease in tumor blood flow. These results indicate that, as this
combination enters Phase I clinical trials, the sequence of paclitaxel followed
by bryostatin-1 will be critical in the clinical trial design.
PMID- 10778983
TI - Synergistic effect of prochlorperazine and dipyridamole on the cellular retention
and cytotoxicity of doxorubicin.
AB - Incubation of drug-resistant human tumor cells with a combination of
prochlorperazine and dipyridamole has additive/synergistic effect on the cellular
retention and cytotoxicity of doxorubicin. In patients administered a fixed dose
of doxorubicin and prochlorperazine with escalating doses of dipyridamole, mean
plasma levels of dipyridamole and prochlorperazine achieved were as high as 3.01
+/- 0.41 microm and 0.94 +/- 0.09 microm, respectively. Plasma samples from
patients were analyzed in an in vitro assay to monitor the effect on the cellular
retention of tritium-labeled daunorubicin in MDR1-transfected P388 cells. In 22
of 49 of the plasma samples analyzed, the daunorubicin in efflux blocking
activity was one-half or greater than that of cells incubated with 12.5 microM
verapamil, a well-known efflux blocker. These observations suggest that a
combination of prochlorperazine and dipyridamole may enhance cellular doxorubicin
retention by blocking efflux while reducing normal tissue toxicity and unwanted
side effects in vivo.
PMID- 10778984
TI - Requirement for the von Hippel-Lindau tumor suppressor gene for functional
epidermal growth factor receptor blockade by monoclonal antibody C225 in renal
cell carcinoma.
AB - Renal cell carcinoma (RCC) is a cytologically and histologically diverse disease
in which a spectrum of distinct molecular alterations occurs, including the
inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene, which is
specific for the clear cell variant of RCC. The prognosis for RCC is poor, and,
to date, no effective systemic treatment is available for this cancer. In the
present study, we assessed the extent to which the transforming growth factor
alpha-epidermal growth factor receptor (EGFR) autocrine loop could be used as a
potential therapeutic target for RCC. Northern blot analysis of transforming
growth factor alpha and EGFR revealed variable but consistent expression of these
transcripts in cell lines derived from both clear cell and non-clear cell RCC
variants, indicating the potential for this autocrine loop in both tumor types.
The therapeutic utility of interruption of this feedback loop was determined by
examining growth inhibition after the exposure of these cell lines to a humanized
anti-EGFR monoclonal antibody, C225. In vitro treatment of clear cell RCC-derived
cell lines lacking VHL resulted in only a modest decrease in growth rate. In
contrast, non-clear cell RCC-derived cell lines that retained VHL responded
significantly to C225 treatment. Transfection of VHL into VHL-negative RCC cell
lines restored responsiveness to C225, indicating that this tumor suppressor gene
is required for effective EGFR blockade. Growth inhibition by C225 in VHL
positive cells was linked to a requirement for VHL to up-regulate p27 in response
to C225. These data provide compelling evidence that treatment modalities for RCC
are likely to be strongly influenced by the molecular etiology of this
phenotypically diverse cancer.
PMID- 10778985
TI - Differential antiproliferative and apoptotic response of sanguinarine for cancer
cells versus normal cells.
AB - Sanguinarine, derived from the root of Sanguinaria canadendid, has been shown to
possess antimicrobial, anti-inflammatory, and antioxidant properties. Here we
compared the antiproliferative and apoptotic potential of sanguinarine against
human epidermoid carcinoma (A431) cells and normal human epidermal keratinocytes
(NHEKs). Sanguinarine treatment was found to result in a dose-dependent decrease
in the viability of A431 cells as well as NHEKs albeit at different levels
because sanguinarine-mediated loss of viability occurred at lower doses and was
much more pronounced in the A431 carcinoma cells than in the normal
keratinocytes. DNA ladder assay demonstrated that compared to vehicle-treated
control, sanguinarine treatment of A431 cells resulted in an induction of
apoptosis at 1-, 2-, and 5-microM doses. Sanguinarine treatment did not result in
the formation of a DNA ladder in NHEKs, even at the very high dose of 10 microM.
The induction of apoptosis by sanguinarine was also evident by confocal
microscopy after labeling the cells with annexin V. This method also identified
necrotic cells, and sanguinarine treatment also resulted in the necrosis of A431
cells. The NHEKs showed exclusively necrotic staining at high doses (2 and 5
microM). We also explored the possibility of cell cycle perturbation by
sanguinarine in A431 cells. The DNA cell cycle analysis revealed that
sanguinarine treatment did not significantly affect the distribution of cells
among the different phases of the cell cycle in A431 cells. We suggest that
sanguinarine could be developed as an anticancer drug.
PMID- 10778987
TI - Apoptosis-inducing vanadocene compounds against human testicular cancer.
AB - We systematically assessed the cytotoxic effects of five metallocene dichlorides
containing vanadium (vanadocene dichloride), titanium (titanocene dichloride),
zirconium (zircodocene dichloride), molybdenum (molybdocene dichloride), and
hafnium (hafnocene dichloride) as the central metal atom and 19 other vanadocene
complexes. These compounds were tested against the human testicular cancer cell
lines Tera-2 and Ntera-2 using both 3-(4,5-dimethylthiazol-2-yl)-2,5
diphenyltetrazolium bromide assays and apoptosis assays. Notably, only the
vanadium(IV)-containing metallocenes exhibited significant cytotoxicity against
Tera-2 and Ntera-2 cells and induced apoptosis within 24 h. Vanadocenes with
dithiocyanate [VCp2(SCN)2 x 0.5 H2O] and diselenocyanate [VCp2(NCSe)2] as
ancillary ligands were identified as the most potent cytotoxic compounds.
Vanadocenes, especially the lead compound VCp2(NCSe)2, may be useful in the
treatment of testicular cancer.
PMID- 10778986
TI - Enhanced antitumor activity of 5-fluorouracil in combination with 2'-deoxyinosine
in human colorectal cell lines and human colon tumor xenografts.
AB - We investigated the effects of 2'-deoxyinosine (d-Ino), a modulator yielding
thymidine phosphorylase activity, on cellular pharmacology of 5-fluorouracil
(FUra) in various human colorectal cell lines and its antitumoral activity when
combined with FUra in human xenografts. Associating d-Ino with FUra increased by
38 up to 700 times the sensitivity of HT29 and FUra-resistant SW620 lines,
respectively, but not of CaCO2 cells, although high levels of intracellular FdUMP
and subsequent higher thymidylate synthase inhibition were observed. Cell death
studies confirmed the ability of d-Ino to enhance both early and late apoptosis
induced by FUra in HT29 and SW620 but not in CaCo2. Similarly, we showed that
associating d-Ino increased by 68 up to 101% the Fas overexpression induced by
FUra in HT29 and SW620 but not in CaCo2 cells. Anti-Fas and anti-FasL antibodies
both partly reversed this increase of cell sensitivity, thus confirming the role
Fas plays in the modulation of FUra toxicity by d-Ino. This Fas component could
explain the discrepancy between the lines because CaCO2 has been described as
insensitive to Fas-mediated apoptosis. Antitumor activity of the combination was
next investigated in nude mice transplanted with SW620. Results showed that
although FUra alone has little effect on SW620 xenografts (P > 0.05), associating
d-Ino significantly reduced the tumor growth by 57% (P < 0.05). This study
suggests that it is possible to reduce both in vitro and in vivo resistance to
FUra by modulating the way the drug is converted after cellular uptake.
PMID- 10778988
TI - Bis(4,7-dimethyl-1,10-phenanthroline) sulfatooxovanadium(IV) as a novel apoptosis
inducing anticancer agent.
AB - In a systematic effort to identify a potent anticancer agent, we synthesized 15
oxovanadium(IV) complexes and examined their cytotoxic activity against 14
different human cancer cell lines. The oxovanadium compounds included mono and
bis ancillary ligands of 1,10-phenanthroline (phen) [VO(phen), VO(phen)2, VO(Me2
phen), VO (Me2-phen)2, VO(Cl-phen), VO(Cl-phen)2, VO(NO2-phen), VO(NO2-phen)2],
2,2'-bipyridyl (bipy) [VO(bipy), VO(bipy)2, VO(Me2-bipy), VO(Me2-bipy)2], and 2
2'-bipyrimidine(bipym) [VO(bipym) and VO-(bipym)2], linked via nitrogen atoms,
and 5'-bromo-2'-hydroxyacetophenone (acph) [VO(acph)2], linked via oxygen donor
atom. The mono-chelated [VO(Me2-phen), compound 3] and bis-chelated-phen[VO(Me2
phen)2, compound 4] complexes were the most potent oxovanadium compounds and
killed target cancer cells at low micromolar concentrations. Notably, the
dimethyl substitution of the phenanthroline rings was essential for the
anticancer activity of both compound 4 [VO(Me2-phen)2] and compound 3 [VO(Me2
phen)] because unsubstituted bis-chelated and mono-chelated phen oxovanadium(IV)
complexes [VO(phen), compound 1, or VO(phen)2, compound 2] were less active.
Addition of a chloro or nitro group to the phen complexes did not significantly
improve the cytotoxic activity of the unsubstituted oxovanadium(IV) complexes.
Irrespective of the ligands, bis-chelated phenanthroline containing compounds
showed better activity than the mono-chelated phenanthroline containing
complexes. The marked differences in the cytotoxic activity of oxovanadium(IV)
complexes containing different heterocyclic ancillary ligands suggest that the
cytotoxic activity of these compounds is determined by the identity of the five
member bidentate ligands, as well as the nature of the substitutents on the
heterocyclic aromatic rings. Our results presented herein provide experimental
evidence that oxovanadium compounds induce apoptosis in human cancer cells.
Oxovanadium compounds, especially the lead compound VO(Me2-phen)2, may be useful
in the treatment of cancer.
PMID- 10778989
TI - Homocamptothecin, an E-ring-modified camptothecin, exerts more potent
antiproliferative activity than other topoisomerase I inhibitors in human colon
cancers obtained from surgery and maintained in vitro under histotypical culture
conditions.
AB - Topoisomerase I (Topo I) is overexpressed in cancer colon tissues compared with
normal colon tissues. Several anti-Topo I inhibitors are already successfully
used in the clinic. We illustrate here the antiproliferative activity of a new
class of Topo I inhibitors, i.e., E-ring-modified camptothecins with enhanced
lactone stability (L. Lesueur-Ginot et al., Cancer Res., 59: 2939-2943, 1999).
Forty-three human colon cancers were obtained from surgical resection and
maintained under organotypical culture conditions for 48 h. Cell proliferation
was assessed in these ex vivo tumor tissue cultures by tritiated thymidine
autoradiography. As a validation of the methodology, we first analyzed in our
model the antiproliferative activity of two clinically active topoisomerase II
(Topo II) inhibitors, Adriamycin and etoposide, which are not active for colon
cancers; and three Topo I inhibitors, camptothecin (CPT) and two clinically
active compounds (especially for colon cancers), i.e., topotecan and the active
metabolite of irinothecan, SN-38. We then compared the antiproliferative activity
of CPT, topotecan, and SN-38 against those of two investigational E-ring-modified
camptothecins, i.e., BN80245 and BN80915. Three concentrations (1, 10, and 100
nM) were studied for each compound. The results indicate that the three Topo I
inhibitors used as references, i.e., CPT, irinothecan, and SN-38, were much more
active than the two Topo II inhibitors, i.e., Adriamycin and etoposide, with SN
38 being the most efficient. The two investigational compounds BN80245 and
BN80915 exerted higher antiproliferative activity than the three anti-Topo I
reference compounds, with the highest activity observed for BN80915.
PMID- 10778990
TI - Identification of receptor-selective retinoids that are potent inhibitors of the
growth of human head and neck squamous cell carcinoma cells.
AB - Retinoids modulate the growth and differentiation of cancer cells presumably by
activating gene transcription via the nuclear retinoic acid receptor (RAR) alpha,
beta, and gamma and retinoid X receptor (RXR) alpha, beta, and gamma. We analyzed
the effects of 38 RAR-selective and RXR-selective retinoids on the proliferation
of 10 human head and neck squamous cell carcinoma (HNSCC) cell lines. All of
these cell lines expressed constitutively all of the receptor subtypes except
RARbeta, which was detected in only two of them. Most of the RAR-selective
retinoids inhibited the growth of HNSCC cells to varying degrees, whereas the RXR
selective retinoids showed very weak or no inhibitory effects. Three RAR
antagonists suppressed growth inhibition by RAR-selective agonists, as well as by
RAR/RXR panagonists such as 9-cis-retinoic acid. Combinations of RXR-selective
and RAR-selective retinoids exhibited additive growth-inhibitory effects.
Furthermore, we found that CD437, the most potent growth-inhibitory retinoid
induced apoptosis and up-regulated the expression of several apoptosis-related
genes in HNSCC cells. These results indicate that: (a) retinoid receptors are
involved in the growth-inhibitory effects of retinoids; (b) RXR-RAR heterodimers
rather than RXR-RXR homodimer are the major mediators of growth inhibition by
retinoids in HNSCC cells; and (c) induction of apoptosis can account for one
mechanism by which retinoids such as CD437 inhibit the growth of HNSCC cells.
Finally, these studies identified several synthetic retinoids, which are much
more effective than the natural RAs and can be good candidates for
chemoprevention and therapy of head and neck cancers.
PMID- 10778991
TI - The new dioxolane, (-)-2'-deoxy-3'-oxacytidine (BCH-4556, troxacitabine), has
activity against pancreatic human tumor xenografts.
AB - There is a great need for new therapeutic agents for patients with advanced
pancreatic cancer. The new dioxolane analogue troxacitabine was evaluated in two
human pancreatic cancer xenograft models. The models used included the Panc-01
and MiaPaCa pancreatic cancer cell lines. Whereas there is certainly no absolute
evidence that either of the in vivo models is predictive for clinical activity,
there is at least some evidence that they may be helpful in selecting agents for
clinical trials in patients with pancreatic cancer. Troxacitabine was
administered i.v. to the animals at doses of 10 and 25 mg/kg on a daily x 5
regimen. Gemcitabine was used as a positive control. The end points for the study
included tumor growth inhibition (TGI), final weight, and the number of partial
and complete tumor responses in the animals. Troxacitabine was highly active
against the Panc-01 model (n = 8), with TGI levels of 88.5% and 84.3% at the 10
and 25 mg/kg doses, respectively. The mean final tumor weights for animals given
troxacitabine were also significantly smaller (P < 0.001) compared with vehicle
controls. At the 10 mg/kg dose, there were three partial tumor shrinkages and one
complete tumor shrinkage, whereas at the 25 mg/kg dose, there were three partial
tumor shrinkages. Troxacitabine had less activity against the MiaPaCa model (n =
10) and, by traditional response criteria, would be considered inactive, with
TGIs of 4% and 22.7% at the 10 and 25 mg/kg dose level, respectively. Of note is
that in comparison with gemcitabine, troxacitabine was more efficacious against
Panc-01 and was equally active against MiaPaCa. These in vivo results are
encouraging and support the prospect of performing Phase II and perhaps Phase III
trials with troxacitabine in patients with advanced pancreatic cancer.
PMID- 10778992
TI - Caspase activation and changes in Bcl-2 family member protein expression
associated with E2F-1-mediated apoptosis in human esophageal cancer cells.
AB - The prognosis for patients with esophageal cancer remains poor, prompting the
search for new treatment strategies. Overexpression of E2F-1 has been shown to
induce apoptosis in several cancer cell types. In the present study, the effect
of adenovirus-mediated E2F-1 overexpression on human esophageal cancer cell lines
Yes-4 and Yes-6 was evaluated. Cells were treated by mock infection, infection
with an adenoviral vector expressing beta-galactosidase (Ad5CMV-LacZ), or E2F-1
(Ad5CMVE2F-1). Western blot analysis confirmed marked overexpression of E2F-1 in
Ad5CMVE2F-1-infected cells. Overexpression of E2F-1 resulted in marked growth
inhibition and rapid loss of cell viability due to apoptosis, although Yes-6
cells were somewhat more resistant to E2F-1-mediated growth inhibition than Yes-4
cells. Cell cycle analysis revealed that overexpression of E2F-1 led to G2
arrest, followed by apoptotic cell death. p53 expression remained undetectable in
both cell lines after E2F-1 overexpression. The apoptosis inhibitor proteins of
the Bcl-2 gene family, Bcl-2, Mcl-1, and BcI-XL, decreased at 48 h after
infection in Yes-4 cells, but remained unchanged in Yes-6 cells. Levels of
retinoblastoma gene product (pRb) declined at 48 h after E2F-1 infection in Yes-4
cells, at which apoptosis predominated, whereas pRb expression remained constant
in Yes-6 cells. Expression of p14ARF did not change after E2F-1 infection in
either cell line. Involvement of caspase 3 and caspase 6 in E2F-1-mediated
apoptosis was demonstrated by cleavage of caspase 3/CPP32 and poly-ADP-ribose
polymerase, as well as fragmentation of the caspase 6 substrate, lamin B. These
results indicate that the sensitivity of esophageal cancer cells to E2F-1
mediated apoptosis may be related to differential expression of Bcl-2 family
member proteins and suggest that the adenovirus-mediated E2F-1 gene therapy may
be a promising treatment strategy for the treatment of this disease.
PMID- 10778993
TI - Energy metabolism of human LoVo colon carcinoma cells: correlation to drug
resistance and influence of lonidamine.
AB - The relationship between modification of energy metabolism and extent of drug
resistance was investigated in two sublines (LoVoDX and LoVoDX10) from human LoVo
colon carcinoma cells that exhibit different degrees of resistance to
doxorubicin. Results indicated that the extent of alteration in energy metabolism
strictly correlated with degree of resistance. In LoVoDX cells, only 14CO2
production was enhanced, whereas in the more resistant LoVoDX10 cells, both 14CO2
and aerobic lactate production were stimulated. The basal and glucose-supported
efflux rate and the amount of drug extruded by LoVoDX10 cells were significantly
higher than in the resistant LoVoDX cells. Because the expression of surface P
170 glycoprotein was similar in both cell lines, this phenomenon was attributed
to increased efflux pump activity resulting from greater ATP availability.
Inhibition of 14CO2 production, aerobic glycolysis, and clonogenic activity by
lonidamine (LND) increased with enhancement of the energy metabolism. Moreover,
LND, by affecting energy-yielding processes, reduced intracellular ATP content,
lowered the energy supply to the ATP-driven efflux pump, and inhibited, almost
completely, doxorubicin extrusion by resistant LoVo cells. These findings
strongly suggest that LND, currently used in tumor therapy, reduces drug
resistance by restoring the capacity to accumulate and retain drug of cells with
the MDR phenotype that overexpress P-170.
PMID- 10778994
TI - Correspondence re: W.M. Lin et al., loss of heterozygosity and mutational
analysis of the PTEN/MMAC1 gene in synchronous endometrial and ovarian
carcinomas. Clin. Cancer Res., 4: 2577-2583, 1998.
PMID- 10778995
TI - Correspondence re: M.S. Tockman et al., Prospective detection of preclinical lung
cancer: results from two studies of heterogeneous nuclear ribonucleoprotein A2/B1
overexpression. Clin. Cancer Res., 3: 2237-2246, 1997.
PMID- 10778996
TI - Usefulness of carotid intima-media thickness measurement and peripheral B-mode
ultrasound scan in the clinical screening of patients with coronary artery
disease.
AB - Previous observational studies have shown a relationship between carotid intima
media thickness (IMT) and coronary artery disease (CAD). In this study the
authors evaluated the accuracy of the common carotid IMT measurement in
predicting the presence and severity of CAD and the additional information
offered by the detection of carotid, iliac, and lower limb plaques. One hundred
and fifty consecutive patients were subjected to coronary angiography and
carotid, iliac, and lower limb ultrasound scan. The mean value of six IMT
measurements of the far wall of the common carotid artery was calculated in each
patient. The mean IMT was significantly correlated to the number of stenosed
coronary vessels (r = 0.43, p<0.001), although the positive and negative
predictive value of mean IMT in identifying patients with CAD was low (81% and
46%, respectively). The combined information offered by IMT measurements and
peripheral (carotid, iliac, and lower limb) plaque detection was then used to
obtain the best multivariate regression model able to predict CAD status. The
multivariate model showed a highly significant multiple correlation coefficient
(r = 0.60, p<0.0001) and a sharp improvement in the negative predictive value
(92%) with respect to the univariable model. B-mode ultrasound scan including
common carotid IMT measurement and peripheral plaque detection may be of clinical
value in the screening of patients with CAD.
PMID- 10778997
TI - Percutaneous transluminal coronary angioplasty performed 24-48 hours after the
onset of acute myocardial infarction improves chronic-phase left ventricular
regional wall motion.
AB - The authors investigated the capacity of percutaneous transluminal coronary
angioplasty (PTCA) performed 24-48 hours after the onset of acute myocardial
infarction (AMI) to improve regional left ventricular wall motion. Twenty-four
patients were divided into two groups: a PTCA group who received successful PTCA
(14 cases) and a non-PTCA group (10 cases) who did not receive PTCA. Left
ventricular end-diastolic volume (LVEDV) increased significantly (p<0.01) from
57+/-14 mL/m2 during the acute phase to 83+/-16 mL/m2 during the chronic phase in
the non-PTCA group, whereas no significant change in LVEDV was seen in the PTCA
group (69+/-26 vs. 76+/-16 mL/m2). In addition, in patients with 99%
stenosis/thrombolysis in myocardial infarction (TIMI) grade 3 flow, increases in
regional left ventricular wall motion (delta(sd)/chord) at the infarcted site
between the acute and chronic phases were significantly greater in the PTCA group
than in the non-PTCA group (2.49+/-1.05 vs. 0.67+/-0.65, p<0.01). PTCA performed
24-48 hours after the onset of AMI improved wall motion at the infarcted site.
PMID- 10778998
TI - Antiplatelet is superior to anticoagulant treatment after coronary stenting:
fewer coronary and other events within 30 days after stenting.
AB - Stent prosthesis is a high efficacious method with low complication rates.
However, the ideal adjunctive therapy following stent implantation remains
controversial. The authors compared the effectiveness and complication rates of
aspirin-ticlopidine antiplatelet therapy vs. anticoagulant therapy with
acenocoumarol within 30 days following stent prosthesis. They prospectively
studied 404 patients following stent prosthesis while randomly receiving
anticoagulant (Group A: 201 patients) vs. antiplatelet treatment (Group B: 203
patients). Groups A and B were similar in demographic data (age, gender), stent
location, clinical presentation, indication of stenting, and type of implanted
stent. Chi-square test, t test, and Wilcoxon test for two samples were used for
statistical analysis of the results. Stent implantation was attempted in 434
cases. This was successful in 70/85 (82%) of the bailout, 122/135 (90%) of the
suboptimal, and 212/214 (99%) of the elective cases. In 201 patients
anticoagulant treatment with acenocoumarol was administered for 4 weeks (group
A), while 203 received antiplatelet treatment with ticlopidine (group B). The
need for reintervention was less and total cardiac events were fewer in group B
than in group A: three (1.5%) and nine (4.4%) vs 18 (9%) and 29 (14.4%), p<0.0008
and p<0.006 respectively. Hemorrhagic complications and total noncardiac events
were fewer in group B than in group A: six (3%) and six (3%) vs. 18 (9%) and 19
(9.5%), p<0.01 and p<0.007 respectively. The length of hospital stay was shorter
in group B than in A, p<0.0001. In conclusion, in this study of intracoronary
stenting the authors had a high success rate in 434 attempted cases. Antiplatelet
therapy was accompanied by fewer cardiac and noncardiac 1 month events when
compared with anticoagulant therapy, supporting its role as the adjunctive
treatment of choice post-stenting for the time being.
PMID- 10778999
TI - Expression of muscarinic receptor genes in the human coronary artery.
AB - The authors investigated the role of muscarinic receptors in functional control
of coronary arteries affected by intimal thickening due to arteriosclerosis. They
first examined the genetic subtypes of muscarinic receptors expressed in human
coronary arteries. Twelve samples of human coronary artery, obtained by autopsy
from eight subjects, were examined for the expression of four genetic subtypes of
muscarinic receptor, m1 to m4, by reverse transcription and polymerase chain
reaction (RT-PCR). Two subtypes, m2 and m3, were found to be expressed in the
coronary artery. The m2 gene was expressed in seven of the 12 vessels, and m3 in
eight of the 12. Expression of both m2 and m3 genes was observed in five of the
12 vessels. Neither the m1 nor m4 was expressed in these samples. These results
indicate that the m2 and m3 genes are mainly expressed in the coronary arteries
and suggest that these patterns of expression are differentially controlled to
induce the diversity of contraction/relaxation reactions induced in the coronary
arteries by acetylcholine.
PMID- 10779000
TI - Assessment of collateral perfusion: a pharmacodynamic study with buflomedil
hydrochloride.
AB - The aim of the study was to assess the influence of Buflomedil hydrochloride on
collateral function. Ten patients with isolated superficial femoral occlusions
were investigated twice by duplex sonography with measurement sites at the common
femoral artery (CF) and the popliteal artery (PA). After the second scan 200 mg
of Buflomedil hydrochloride were infused; the infusion was followed by a third
duplex examination. Endpoints assessed included the arterial diameter (D(CF),
D(PA)), the systolic peak velocity (Vmax), the mean velocity of the maximum
envelope (Vmean m.e.), the intensity weighted time average mean velocity (Vmean
i.w.), the maximum reverse flow velocity (Vrev), the end-diastolic velocity
(Venddiast), the calculated volume flow (Q), the pulsatility and the resistance
indices (PI, RI), and PI and RI based segmental damping factors (DF(PI), DF(RI)).
For the CF measurement site the infusion of Buflomedil hydrochloride resulted in
a significant reduction in Vrev and PI (p<0.05), whereas trends in the opposite
direction (increase) were observed for both measures of Vmean and for Q
(0.1150 x 109/L) and 4
(10.5%) had a platelet count between 50 and 150 x 109/L. Only two of the five
(13.2%) remaining patients who continued to have a platelet count less than 50 x
109/L had hemorrhagic manifestations necessitating intermittent therapy with
corticosteroids. CONCLUSION: Laparoscopic or open splenectomy is a safe and
effective procedure for children with chronic or refractory ITP and should be
considered when medical management fails or causes excessive toxicity.
PMID- 10779030
TI - Jaundice caused by the vanishing bile duct syndrome in a child with Hodgkin
lymphoma.
AB - The authors report a 5-year-old boy with Hodgkin disease and cholestatic jaundice
that predated the start of treatment for his lymphoma. His clinical course was
punctuated by relentless progression of jaundice, characterized by obstructive
pattern liver function tests, severe pruritus, intermittent fever, and marked
hypercholesterolemia with development of palmar xanthomata. The jaundice was
found to be attributable to vanishing bile duct syndrome (VBDS). The extent of
hepatic dysfunction precluded appropriate treatment of the lymphoma with
chemotherapy, and the boy died of liver failure. In the differential diagnosis of
jaundice in children with Hodgkin disease, VBDS should be considered.
PMID- 10779031
TI - Paraneoplastic cerebellar degeneration and Horner syndrome: association of two
uncommon findings in a child with Hodgkin disease.
AB - An 11-year-old boy admitted with a right cervical mass was found to have Hodgkin
disease. On admission, he also had right Homer syndrome and severe cerebellar
ataxia. Cranial MRI revealed marked cerebellar atrophy. He was treated with
chemotherapy consisting of doxorubicin, bleomycin, vinblastine, and dacarbazine
(ABVD), in addition to radiotherapy. Three months after initiation of therapy, he
had a partial remission of tumor. Neurologic symptoms improved dramatically after
chemotherapy started. Hodgkin disease should be included in the differential
diagnosis of children with cerebellar findings and Horner syndrome.
PMID- 10779032
TI - Epstein-Barr virus--positive undifferentiated thymic carcinoma in a 12-year-old
white girl.
AB - Thymic epithelial malignant diseases are extremely rare in children. The authors
report a 12-year-old white girl admitted for a polymetastatic tumor of the
anterior mediastinum. Tumor proliferation was typical of an undifferentiated
thymic carcinoma. A close link between Epstein-Barr virus (EBV) and the tumor was
established by a high titer of anti-VCA IgA and the presence of EBV RNA and DNA
in the tumor. In addition, monoclonal viral episomes were present in tumor cells,
indicating that EBV infection was an early event in the oncogenic process. The
patient died despite resection, irradiation, and chemotherapy.
PMID- 10779034
TI - Wilms tumor in a child with trisomy 13.
AB - A 4-year-old black boy with trisomy 13, a history of frequent urinary tract
infections, and a horseshoe kidney with painless gross hematuria was examined. An
abdominal mass was detected and surgically resected. Examination of the surgical
specimen revealed a Wilms tumor. Given the concurrence of trisomy 13 and Wilms
tumor and the presence of another such case in the literature, there may be just
cause to suspect a locus on chromosome 13 that affects the probability of
developing Wilms tumor. Given the increasingly longer survival of patients with
trisomy 13, clinicians may need to be aware of the possibility of renal malignant
disease in this population of patients.
PMID- 10779033
TI - Central nervous system involvement of Epstein-Barr virus lymphoproliferative
disease in a patient with acute lymphocytic leukemia.
AB - Epstein-Barr virus-related lymphoproliferative disease (EBV-LPD) is a serious and
often fatal complication of a variety of immune-suppressed conditions. A 6-year
old boy undergoing chemotherapy for standard-risk acute lymphocytic leukemia
experienced separate episodes of EBV-LPD in different organ systems. The patient
experienced three separate episodes of EBV-LPD in the cervical lymph node, the
central nervous system (CNS), and the liver occurring, respectively, in January
1992, February 1992, and November 1993 after the completion of chemotherapy in
May 1993. The EBV presence was confirmed by in situ hybridization in the biopsy
samples from each lesion. Several different treatment modalities, including
acyclovir, intravenous gamma globulin, and surgery were used to combat the EBV
LPD. The patient has recovered completely, with normal CNS and liver function,
and for the past 6 years has experienced leukemia remission while not receiving
chemotherapy. Careful monitoring of patients and the use of new immune therapies
offer the highest chance for successful outcomes in such patients.
PMID- 10779035
TI - Long-term survival in an adolescent with widely metastatic renal cell carcinoma
with rhabdoid features.
AB - Renal cell carcinoma is rarely seen in children and adolescents. Patients with
widespread disease at diagnosis have a particularly poor survival rate.
Currently, all known chemotherapy has been ineffective in improving the median
survival in patients with advanced disease. A 13-year-old black boy with stage IV
renal cell carcinoma with rhabdoid features is a long-term disease-free survivor
after aggressive multiagent chemotherapy. After the initial evaluation and
histologic diagnosis of renal cell carcinoma, the patient received three courses
of an aggressive chemotherapy regimen consisting of vincristine, doxorubicin,
cyclophosphamide with mesna uroprotection, granulocyte colony-stimulating factor
and erythropoietin (Epogen). After an almost complete response, a radical
nephrectomy was performed and results demonstrated a solitary small nodule with
viable tumor. After surgery, he received floxuridine infusion for 14 days by
circadian schedule at 28-day intervals for a total of 1 year. The patient is well
and free of disease 5 years after initial presentation. The dramatic response to
treatment and long-term disease-free survival of this patient suggest this
chemotherapeutic approach warrants additional investigation.
PMID- 10779036
TI - Diamond-blackfan anemia and cyclosporine therapy revisited.
AB - A girl with Diamond-Blackfan anemia diagnosed in infancy started cyclosporine A
(CSA) therapy at 9 years and 8 months of age after experiencing unacceptable side
effects while receiving prednisone. Since then, she has been followed-up for more
than 4 years. She exhibited a dramatic response to CSA, with weaning and then
cessation of steroid therapy after 5 months. She has remained transfusion
independent. Attempts to discontinue CSA therapy have been unsuccessful. Relapse
of the anemia has occurred in the context of viral infections with missed CSA
doses. The major clinical problem during treatment has been recurrent oral
aphthous ulceration, which responds to topical therapy. She is currently
maintained on CSA 100 mg twice daily with a hemoglobin of 10.2 g/dL and a
reticulocyte count of 1.6%. A trial of CSA therapy should be considered in
patients with Diamond-Blackfan anemia in whom steroid therapy has failed before a
transfusion program is instituted or alternative donor stem cell transplantation
is entertained.
PMID- 10779037
TI - Multicentric Castleman disease and systemic lupus erythematosus phenotype in a
boy with Klinefelter syndrome: long-term disease stabilization with interferon
therapy.
AB - An 11-year-old boy with Klinefelter syndrome had Castleman disease (CD) of plasma
cell type develop. Nonregulated antibody production mimicked systemic lupus
erythematosus (SLE). Hepatitis C virus (HCV) infection caused significant disease
worsening. The patient was treated with a daily dosage of 2 million units/m2 of
IFN-alpha. Dramatic clinical improvement and decreasing autoimmune phenomenon
were observed. HCV RNA were cleared. Hypergammaglobulinemia did not change. The
boy has been living for 8 years with his disease. Plasma cell type CD can mimic
collagenosis. Disease worsening is caused by HCV, though it can be reversed with
IFN-alpha. Klinefelter syndrome may be a genetic susceptibility factor for CD in
some cases.
PMID- 10779038
TI - Plasma homocysteine levels in sickle cell disease and the need for folate
supplementation.
PMID- 10779039
TI - Homocysteine levels and sickle cell anemia.
PMID- 10779040
TI - Homocysteine levels and sickle cell anemia: response to Rana et al.
PMID- 10779041
TI - Aplastic crisis and acute splenic sequestration crisis.
PMID- 10779042
TI - Renal carcinoma in a patient with glycogen storage disease Ib receiving long-term
granulocyte colony-stimulating factor therapy.
PMID- 10779043
TI - Influence of ovariectomy on extracellular fluid volume in rats: assessment of
extracellular fluid volume by means of bromide.
PMID- 10779044
TI - Reactive oxygen species and endothelins in diabetic nephropathy.
PMID- 10779045
TI - Influence of ovariectomy on extracellular fluid volume in rats: assessment of
extracellular fluid volume by means of bromide.
AB - There is considerable evidence that the extracellular fluid volume (ECV) may
change in disease states or during longitudinal Intervention studies. Therefore,
the measurement of ECV is Important for studying body composition in patients and
laboratory animals. We present a modified plasma bromide (Br-, non-radioactive)
assay using anion-exchange chromatography, in which a small blood sample of 200
microL (100 microL of plasma) appeared to be enough to reproducibly measure ECV.
The inter- and intra-assay accuracy of the Br- analysis ranged from -1.6% to 0.9%
and from -0.5% to 0%, respectively. The inter- and intra-assay precision ranged
from 1.3% to 1.7% and from 0.6% to 1.2%, respectively. This modified precise and
accurate Br- analysis in a small blood sample was applied to investigate whether
the ECV changed in rats after ovariectomy. Ovariectomy significantly (P < .05)
reduced the ECV as compared with results in SHAM rats. This observation indicates
that a change in clinical condition may change ECV, which has consequences for
the determination of, for example, the fractional absorption and the relative
bioavailability of compounds principally distributed through the ECV.
PMID- 10779046
TI - Reactive oxygen species enhances endothelin-1 production of diabetic rat
glomeruli in vitro and in vivo.
AB - Both reactive oxygen species (ROS) and endothelin-1 (ET- 1) have been implicated
in the pathophysiology of diabetic nephropathy. The interrelationship between
them, however, has not been documented in this disease. To determine whether ROS
regulates ET-1 production in diabetic kidneys, we examined the in vitro and in
vivo effects of ROS donors and scavengers on ET-1 production of diabetic rat
glomeruli. For in vitro study, the glomeruli were isolated with a sieving method
from streptozotocin-induced diabetic rats and killed at 1 week, 1 month, and 3
months, respectively. Superoxide was measured by a spectrophotometer, and ET-1
was measured by radioimmunoassay. The results demonstrated that the basal
production levels of superoxide and ET-1 were higher in diabetic glomeruli than
in normal glomeruli in vitro. There was a positive correlation between the
production of superoxide and ET-1 in diabetic glomeruli. The basal ET-1
production was markedly attenuated by ROS scavengers including superoxide
dismutase, catalase, dimethyl sulfoxide, and deferoxamine in diabetic glomeruli.
Exogenous ROS generated by xanthine/xanthine oxidase significantly enhanced ET-1
generation by both diabetic and normal glomeruli. A high glucose concentration
(500 mg/dL) in vitro increased ET-1 production by normal glomeruli but not
diabetic glomeruli, and insulin partly suppressed ET- 1 production by diabetic
glomeruli. The in vivo study demonstrated that when diabetic rats were injected
daily with superoxide dismutase or catalase after diabetes was induced, the basal
production of ET-1 was markedly attenuated after 1 week and 1 month,
respectively. These results indicate that exogenously or endogenously derived ROS
can enhance ET-1 production by diabetic rat glomeruli and that ROS scavengers
suppress ET- 1 production both in vitro and in vivo. The effects of ROS on ET-1
production of diabetic glomeruli may be partly caused by the effect of
hyperglycemia or insulin deficiency.
PMID- 10779047
TI - Cardiac remodeling by fibrous tissue after infarction in rats.
AB - After transmural myocardial infarction (MI), extensive myocardial remodeling by
fibrous tissue appears in both infarcted and noninfarcted myocardium, which
contributes to ventricular diastolic dysfunction. In the present study we sought
to assess the time course of collagen remodeling in the infarcted rat hearts by
detecting spatial and time-dependent cellular events related to collagen
synthesis and degradation 2 to 28 days after left coronary artery ligation. In
infarcted hearts, and compared with findings in sham-operated and unoperated rat
hearts, we found the following: (1) macrophages infiltrated into sites of MI and
visceral pericardium on day 2 and gradually disappeared after day 14; (2)
myofibroblasts (MyoFb) first appeared at these sites of repair on day 3 and
remained abundant thereafter at all time points examined; (3) transforming growth
factor-beta1 (TGF-beta1) mRNA was enhanced in infarcted and noninfarcted
myocardium on day 2 and remained throughout 28 days; (4) type I and III collagen
mRNAs began to increase at and remote to MI on day 3 and remained elevated
thereafter; (5) matrix metalloproteinase-1 mRNA was significantly increased at
and remote to MI on day 3, declined to the control level on day 7, and remained
low thereafter; (6) tissue inhibitor of matrix metalloproteinase (TIMP)-I, -II,
and -III mRNAs were markedly elevated at sites of repair on day 3 and sustained
throughout 28 days; (7) fibrillar collagen accumulation that was evident at and
remote to MI on day 7 continued to accumulate thereafter at each site over 4
weeks. When compared with findings in unoperated rat heart, pericardial fibrosis
was evident in both infarcted and noninfarcted heart, and the temporal response
of collagen generation/ degradation in pericardium was similar to that in
infarcted myocardium. Thus collagen synthesis is activated in both infarcted and
noninfarcted rat myocardium after transmural anterior infarction and is
persistent throughout the 28-day period of study, whereas early collagen
degradation is short lived and inactivated in the fibrogenic phase. Activated TGF
beta1 mRNA expression is accompanied by the appearance of MyoFb and the
expression of fibrillar collagens and TIMPs, suggesting that this fibrogenic
cytokine may contribute to collagen remodeling in the rat heart after MI.
PMID- 10779048
TI - Up-regulation of the proteasome subunit LMP7 in tissues of endotoxemic rats.
AB - The proteasome has been implicated in systemic responses to infection or
inflammatory stimuli including catabolism of skeletal muscle. Cytokines including
tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) are
known to be elevated systemically and locally under these conditions. They are
also known to be potent inducers of three peptide subunits of the proteasome,
including LMP7, that replace constitutively expressed subunits and change
enzymatic properties. To determine whether endotoxemia alters the expression of
inducible proteasome subunits, we examined the levels of LMP7 in tissues from
rats 3 days after the injection of lipopolysaccharide (LPS) or normal saline
solution (NS). By both immunoblotting and immunohistochemistry, significant
increases in levels of LMP7 were observed in the heart, kidney, and lung of
animals given LPS as compared with results in NS-treated animals, whereas
immunoblotting revealed no changes in LMP7 levels in skeletal muscle or brain.
Increased expression of LMP7 was limited to certain subpopulations of cells and
was further localized at the subcellular level. Decreases in organ weight were
also documented for organs in which the expression of LMP7 was up-regulated.
Systemic or local release of cytokines or other proinflammatory mediators is
suggested as the most likely mechanism for changes in LMP7 expression during
endotoxemia. Changes in LMP7 expression may have functional consequences that
contribute to organ dysfunction during systemic responses to infection and
inflammatory stimuli.
PMID- 10779049
TI - Vascular endothelial growth factor in bronchoalveolar lavage from normal subjects
and patients with diffuse parenchymal lung disease.
AB - Vascular endothelial growth factor (VEGF) is a potent angiogenic agent that is
expressed by epithelial cells in the mature lung of various animal species. We
hypothesized that VEGF levels in lower respiratory tract secretions may vary with
age or with lung inflammation in human beings. We measured VEGF165 in
bronchoalveolar lavage fluid (BALF) from normal volunteers (NVs) of varying age
and from patients with cystic fibrosis (CF), sarcoidosis, or idiopathic pulmonary
fibrosis (IPF). A considerable gradient in VEGF levels was found with relatively
high VEGF concentrations in BALF as compared with serum VEGF. VEGF levels were
303 +/- 34 pg/mL (mean +/- SEM) in serum samples from patients with CF (N = 9)
versus 122 +/- 16 pg/mL for the comparable, youngest group of NVs (P < .01). BALF
VEGF concentrations were 165 +/- 17 pg/mL for CF upper lobe BALF (N = 9), 140 +/-
17 pg/mL for CF lower lobe BALF (N = 9), and 235 +/- 24 pg/mL for young adult NVs
(N = 29). Serum VEGF levels did not differ significantly between NVs and patients
with interstitial lung disease, but mean BALF VEGF levels declined significantly
with advancing age in NVs and were significantly depressed in patients with IPF
(32 +/- 6 pg/mL) as compared with all other groups, including the oldest group of
NVs (134 +/- 13 pg/mL, P < .0001). We conclude that a considerable gradient in
VEGF concentration exists from epithelial bronchoalveolar surface fluid to serum.
Concentrations of VEGF in lower respiratory tract secretions vary with age and
are significantly depressed in IPF.
PMID- 10779050
TI - Animal models for studies on cold-induced platelet activation in human beings.
AB - When human platelets are chilled below about 20 degrees C, they spontaneously
activate, a phenomenon that limits their storage lifetime. We have previously
shown that this activation in chilled human platelets is associated with passage
through a lipid phase transition. Because animal models are necessary for
Investigating methods for cold storage of platelets, it is essential to determine
whether such phase transitions and chilling-induced activation are found in these
models. In this study we examined platelets from some commonly used animal models
pigs, rhesus monkeys, mice, dogs, and rabbits. Using Fourier transform infrared
spectroscopy (FTIR), we detected the thermotropic membrane phase transition in
Intact platelets and assessed the morphologic response of the platelets to
chilling. Statistical analysis of both FTIR and shape change show that of the
animal models tested, pig platelets are most similar to human platelets. These
studies suggest that pigs and pig platelets are the models of choice for the
study of cold-induced platelet activation in human beings.
PMID- 10779051
TI - Influence of parathyroid hormone, calcitonin, 1,25(OH)2 cholecalciferol, calcium,
and the calcium ionophore A23187 on erythrocyte morphology and blood viscosity.
AB - Parathyroid hormone and calcitonin, both endocrine modulators of calcium
homeostasis, may influence blood rheology. Parathyroid hormone is known to reduce
erythrocyte survival, leading to anemia. Calcitonin has been found to have some
vascular effects. We have analyzed the Influence of parathyroid hormone (10(-7)
to 10(-10) mol/L), calcitonin (10(-6) to 10(-12) mol/L), 1,25(OH)2
cholecalciferol (10(-7) to 10(-10) mol/L), additional calcium in plasma (+1 and 2
mmol/L), and the calcium lonophore A23187 (50 micromol/L) on erythrocyte
morphology and blood viscosity at high shear rate (94 s(-1)) and low shear rate
(0.1 s(-1)) in vitro. The loading of erythrocytes with calcium by the ionophore
A23187 produced a marked echinocytic shape transformation, an increased blood
viscosity at high shear rate caused by decreased deformability of these cells,
and a decreased viscosity at low shear rate caused by decreased aggregation of
echinocytes. In contrast, increasing plasma calcium concentrations, parathyroid
hormone, calcitonin, and 1,25(OH)2 vitamin D3 had no effect on erythrocyte
morphology and blood viscosity. We conclude that an increase in intraerythrocytic
calcium leads to severe echinocytosis and altered blood viscosity. The endocrine
modulators of calcium homeostasis--namely, parathyroid hormone, calcitonin, and
1,25(OH)2 vitamin D3--apparently do not influence intraerythrocytic calcium to a
significant degree and have, therefore, no influence on cell morphology and blood
viscosity.
PMID- 10779052
TI - Angiotensin II-induced cardiomyocyte hypertrophy and cardiac fibrosis in stroke
prone spontaneously hypertensive rats.
AB - Angiotensin-converting enzyme inhibitors (ACEIs) cause regression of hypertensive
left ventricular hypertrophy (LVH) by reducing angiotensin II, increasing
bradykinin, or both. The mechanisms of these cardioprotective effects remain
controversial. The aims of this study were to determine whether the
cardioprotective effects of ACEIs are mediated by reducing angiotensin II and
whether ACEIs ameliorate the morphologic, physiologic, and biochemical changes in
the hearts of stroke-prone spontaneously hypertensive rats (SHRSPs). Male SHRSPs
were treated with hydralazine, captopril, or candesartan, an angiotensin II type
1 receptor (AT1R) antagonist, from age 12 to 24 weeks. We measured systolic blood
pressure (SBP), left ventricular weight (LVW), left ventricular (LV) myocyte
cross-sectional area (myocyte size), LV Interstitial collagen volume fraction
(ICVF), perivascular collagen area/luminal area ratio (PVCA/LA), the medial area
to luminal area ratio (MA/LA), the relative amount of V3 myosin heavy chain
(MHCV3), and coronary reserve maximum (coronary flow max/ventricular weight
(CFmax/VW)). These parameters were compared with those of untreated SHRSPs and
Wistar-Kyoto rats (WKYs). SHRSPs exhibited decreased coronary reserve and LVH
with an increase in myocyte size, PVCA/LA, MA/LA, and MHCV3 at 12 weeks of age.
In addition to these changes, 24-week-old SHRSPs showed an increase in ICVF. The
LVW, coronary reserve, myocyte size, PVCA/LA, ICVF, and MHCV3 of SHRSPs treated
with captopril or candesartan all approached control values. In contrast,
hydralazine decreased only ICVF. These results suggest that ACEIs regress LVH and
normalize coronary reserve by modulating the effects of angiotensin II via AT1R
on the induction of cardiomyocyte hypertrophy, perivascular fibrosis, and medial
thickening of intramyocardial coronary arteries in SHRSPs. We concluded that
these effects, in addition to the reduction of SBP, are important in causing the
regression of LVH.
PMID- 10779053
TI - Minimally invasive surgery for primary hyperparathyroidism: a systematic review.
AB - BACKGROUND: The aim of the present paper was to systematically review the
literature regarding the safety and efficacy of minimally invasive
parathyroidectomy techniques in patients with primary hyperparathyroidism.
Studies using unilateral or endoscopic exploration following imaging were
compared with bilateral open neck exploration. METHODS: Studies on minimally
invasive parathyroid surgery were identified using MEDLINE (1984 to August 1998),
EMBASE (1974 to August 1998) and Current Contents (1993 to week 34, 1998). The
search terms were ((endoscop* or (minimal* and invasive) or unilateral) and
parathyroid). The Cochrane Library was searched from 1966 to issue 3 1998, using
the search terms 'parathyroidectomy or parathyroid resection'. Human studies of
patients with primary hyperparathyroidism using unilateral or endoscopic
exploration were included. Animal studies describing minimally invasive technique
development were also included. A surgeon and researcher independently assessed
the retrieved articles for their inclusion in the review. Studies directly
comparing the unilateral method with bilateral open neck exploration were used to
analyse outcomes. RESULTS: Analysis of data using odds ratios and 95% confidence
intervals (CI) indicated a tendency to favour the unilateral technique. These
individual studies generally had large CI, however; therefore preference to the
unilateral procedure cannot be espoused with certainty. There is also a selection
bias due to the strict enrollment criteria for unilateral surgery. CONCLUSIONS:
The proposed role of minimally invasive parathyroid surgery is for patients with
primary hyperparathyroidism who have unilateral parathyroid pathology. To assess
the safety and efficacy of minimally invasive techniques it is suggested that
their introduction be monitored as part of a trial in Australia, from which data
should be accrued to a register.
PMID- 10779054
TI - Zuckerkandl's tubercle of the thyroid gland in association with pressure
symptoms: a coincidence or consequence?
AB - BACKGROUND: The Zuckerkandl's tubercle (ZT) of the thyroid gland is a well
described anatomical landmark, but few studies have clearly defined its
association with pressure symptoms. METHODS: Sixty-six consecutive patients who
had primary thyroid surgery were prospectively included in the present study
between late January and early August 1998. RESULTS: A total of 96 capsular
dissections were performed at thyroid surgery. Grades two and three ZT were
recognized in 77 (80.2%) dissections. In general 49 (63.6%) of them were
associated with significant pressure symptoms. In 43 (87.8%) of the dissections
with pressure symptoms, grade 3 ZT was observed (mean weight of goitre: 154.8 g).
Interestingly in this group, 16 (37.2%) patients with pressure symptoms had a
goitre that was < 100 g and in one patient it was only 21 g. CONCLUSIONS: The
pressure symptom of the thyroid gland does not always appear to be due to the
large size of the goitre. In a relatively small-size goitre the ZT may cause
significant pressure symptoms. Observations in the present study supported a
strong association of enlarged ZT with pressure symptoms. We believe this is
unlikely to be simply a coincidence but rather a consequence of the enlarged
tubercle. Nonetheless a prospective randomized study is called for to allow
meaningful and objective evidence to be drawn.
PMID- 10779055
TI - Gastric resection in the aged (> or = 80 years) with gastric carcinoma: a
multivariate analysis of prognostic factors.
AB - BACKGROUND: The incidence of gastric neoplasm is increasing in the elderly
population. Therefore, a rational method of treatment for gastric cancer in the
elderly should be constituted to improve the survival. The purpose of the present
study was to clarify whether the patient's age is an independent prognostic
factor and to determine clinicopathological characteristics in the elderly.
METHODS: Curative resection of gastric cancer was carried out on 601 patients who
were 40 years or older. They were divided into the following two groups: younger
patients (between 40 and 79 years old) and elderly patients (80 years or older).
The clinicopathologic features of these patients were reviewed retrospectively
and multivariate analysis was carried out. RESULTS: The distinguishing features
of gastric cancer in the elderly patients were intestinal and mixed types of
cancer, distal third stomach dominance in the tumour location, advanced stage of
disease, and a low rate of extensive lymph node dissection (D3 or more).
Regarding the recurrence site, the liver was the dominant site in the elderly
group (25.3% in the younger group vs 54.5% in the elderly group). The 10-year
disease-free survival rate of the elderly group was 53.2%, which was
significantly worse than that (79.9%) of the younger patients (P = 0.0004). In
multivariate analysis, an age of > or = 80 years is an independent prognostic
factor, as well as stage, depth of tumour invasion, lymph node metastasis,
scirrhous carcinoma, and blood transfusion. CONCLUSIONS: Results indicate that
gastric cancer in elderly patients has a poorer prognosis than that in younger
patients.
PMID- 10779056
TI - Large bowel volvulus in childhood.
AB - BACKGROUND: Large bowel volvulus is extremely uncommon in children. The probable
pathogenesis, predisposing factors and management of large bowel volvulus in
children are debatable. METHODS: Seven consecutive cases of large bowel volvulus
occurring over a 6-year period are reported. RESULTS: Two patients with caecal
volvulus, one with transverse and subsequent sigmoid volvulus, one with
transverse colon volvulus and three children with sigmoid volvulus are reported.
Four girls and one boy with cerebral palsy, one female with Moya Moya disease and
spastic paraplegia and an otherwise healthy boy presented at a mean age of 8.3
years (range: 3-15 years). The common presentation was abdominal distension (n =
6), tenderness (n = 6), constipation (n = 7) and bloody mucoid discharge per
rectum (n = 6). Plain abdominal X-ray and barium enema were diagnostic. Resection
with primary ileocolic, colocolic or colorectal anastomosis was performed in all
cases. The mean follow-up was 3.4 years (range: 1-6 years) and there was no
mortality. CONCLUSIONS: Large bowel volvulus in children may be due to congenital
anomalous or absent ligamentous fixation of the large bowel, and abnormal
mesocolon or a common ileocolo-mesentery. Large bowel obstruction due to volvulus
must be considered in the differential diagnosis in a child presenting with
constipation associated with bloody mucoid discharge per rectum. Resection of the
involved segment and primary anastomosis is the definitive treatment for large
bowel volvulus in children.
PMID- 10779057
TI - Neck dissection and ipsilateral radiotherapy in the management of cervical
metastatic carcinoma from an unknown primary.
AB - BACKGROUND: In a small proportion of patients presenting with metastases to
cervical lymph nodes the primary cancer remains occult despite thorough
evaluation. The present report examines patterns of failure and outcome following
an initial treatment strategy directed principally at the clinically involved
side of the neck. METHODS: From a prospectively compiled computerized database 38
patients were identified with metastatic squamous cell carcinoma from an occult
primary site. These patients were evaluated with respect to initial treatment,
subsequent detection of a primary tumour, neck recurrence and survival
characteristics. RESULTS: Thirty-seven of 38 patients were treated with curative
intent and all had neck dissection. Adjuvant radiotherapy was given to 34 of the
37 (90%; 32 postoperatively and two pre-operatively). Radiotherapy was directed
at the ipsilateral neck alone in 24 patients while 10 received comprehensive
treatment to both sides of the neck and potential occult primary sites. The rate
of control of disease in the ipsilateral neck was 91% while the failure rate in
the contralateral neck was 16% (six patients). A primary cancer was ultimately
identified in five patients (13%). Disease-specific survival was 63% at 4 years.
Clinical N3 stage, extracapsular tumour extension and involved surgical margins
predicted for poorer survival on univariate analysis. Analysis using multiple
risk factors found that only involved surgical margins predicted for treatment
failure. CONCLUSIONS: Despite generally advanced disease at presentation,
patients presenting with cervical metastasis from an unknown primary carcinoma
have a reasonable survival expectation and aggressive treatment is warranted, but
approximately half will develop recurrent disease. Careful follow-up is required
if effective salvage treatment is to be instituted.
PMID- 10779058
TI - Rectal cancer in the Kingdom of Saudi Arabia: the King Faisal Specialist Hospital
experience.
AB - BACKGROUND: No survival data have yet been published from the Kingdom of Saudi
Arabia for patients with rectal cancer. The present paper reports experience with
these patients over an 8-year period. METHODS: All patients referred to the King
Faisal Specialist Hospital (KFSH) between March 1990 and February 1998 for the
primary management of rectal cancer were entered into a computerized database.
Prior to 1993 patients did not receive adjuvant therapy. Kaplan-Meier survival
curves and the log-rank test were used to compare outcome data. RESULTS: There
were 70 men (average age: 55.6 years) and 75 women (average age: 52.8 years).
Twelve per cent of patients admitted a family history of colorectal carcinoma
(CRC). Twenty-seven per cent of tumours were circumferential. Most tumours were
larger than 4 cm and the lowest edge of the majority of tumours was less than 6
cm from the anal verge. Fifty-four per cent of tumours were fixed; 69% of
patients received either pre-operative or postoperative radiotherapy. A total of
106 patients underwent 'curative' surgery. Equal numbers of patients had abdomino
perineal resection (APR) and anterior resection (AR) of the rectum. Thirty-five
patients received blood peri-operatively (APR, 34%; AR, 12%). Major anastomotic
leakage following AR occurred in two patients. Two patients died within 30 days
of surgery. Ten patients were lost to follow-up. Following curative AR, eight
patients had a distal resection margin of < 2 cm and two patients (Dukes' C)
developed local recurrence (25%); 37 patients had a margin > 2 cm and seven
developed local recurrence (18.9%). A total of 48 patients underwent curative
APR, and four patients developed local recurrence (8.3%). Overall local
recurrence was tumour stage-dependent (Dukes' B, 8.8%; Dukes' C, 29.3%).
Recurrence was local in 13 patients. Pre-operative radiotherapy seemed to reduce
average tumour size (3.6 vs 4.3 cm). The crude overall 5-year survival rate was
39%. The 5-year survival rate for patients with Dukes' stage C cancers following
'curative' surgery was 25%. CONCLUSION: Curative surgery can be performed with a
relatively low requirement for blood transfusion, a low mortality and morbidity,
and comparable outcomes to Western studies in spite of the large, low and often
advanced stage of the tumours managed. Local recurrence rates following curative
resection and re-anastomosis for low rectal cancers may be reduced by resisting
patient pressure to avoid stomata.
PMID- 10779059
TI - Eighteen-year experience with femoro-femoral bypass.
AB - BACKGROUND: The role of femoro-femoral bypass in the management of aorto-iliac
occlusive disease has evolved during the past two decades. The aim of the present
study was to evaluate the early and long-term outcomes of femoro-femoral bypass
grafts performed at the University of Hong Kong Medical Centre during an 18-year
period. METHODS: From 1981 to 1998, a retrospective analysis of 61 patients who
underwent femoro-femoral bypass at the University of Hong Kong Medical Centre was
undertaken. Data on demographic features and results of surgical intervention
were reviewed. Early outcomes (morbidity, mortality and improvement of clinical
category) and long-term outcomes (graft patency, patient survival and limb
salvage rates) were analysed. RESULTS: The postoperative morbidity and mortality
rates were 16% and 7%, respectively. Clinical success was achieved in 48 patients
(79%) after operation. The primary patency of femoro-femoral bypass was 86%, 79%
and 71% at 1, 3 and 5 years, respectively. The limb salvage rate was 85% at 3
years. The cumulative survival rate of the study population was 89%, 82% and 73%
at 1, 3 and 5 years, respectively. CONCLUSIONS: Femoro-femoral bypass was
successful in relieving ischaemic pain and limb salvage in approximately 80% of
patients. A 5-year patency rate of 71% was achieved. Femoro-femoral bypass
remains a valuable surgical procedure for limb salvage in poor-risk patients with
unilateral iliac artery occlusion.
PMID- 10779060
TI - Study populations and casemix: influence on analysis of postoperative outcomes.
AB - BACKGROUND: The importance of patient casemix as a determinant of surgical
outcome is now being recognized. The present study was undertaken in order to
compare the presentation and outcomes in colorectal patients managed surgically
by the same surgeon, in the same way, in different settings. METHODS: Colorectal
outcome data from the University Department of Surgery in Wellington and the King
Faisal Specialist Hospital in Riyadh were analysed in order to determine casemix
differences between the two hospitals. Data relating to the type of surgery, the
surgeon, the patient's disease, the operation performed and the postoperative
complications were compared. Specific colorectal clinical indicators were
compared for two commonly performed operations for rectal cancer: anterior
resection and abdomino-perineal resection of the rectum. RESULTS: Wellington
patients were slightly older and there were more females. Emergency surgery was
more frequent in Wellington. Left hemicolectomy, sigmoid colectomy, abscess
drainage and pilonidal surgery were more common in Wellington whereas abdomino
perineal resection and anterior resection of the rectum, stoma closure, fistula
surgery, seton insertion, restorative proctocolectomy and ileostomy were
undertaken more frequently in Riyadh. More complex anal fistulas were managed in
Riyadh. Condylomata accuminata, pilonidal abscess, anorectal abscess, rectal
prolapse and diverticular disease were rarely seen in Riyadh. There were more
postoperative pulmonary and cardiac complications in Wellington. Patients having
anterior resection of the rectum were younger in Riyadh and there were
proportionally more females. There were some obvious numerical outcome
differences in postoperative atelectasis, wound infection, anastomotic leak and
deep vein thrombosis rates but none of these reached statistical significance
except atelectasis. In Riyadh the usual male-to-female ratio of patients
undergoing abdomino-perineal resection was reversed but, again, none of the
numerical outcome differences observed reached statistical significance except
postoperative atelectasis and intraabdominal abscess. CONCLUSION: Although not
statistically significant, the results of the present study suggest that when the
same surgeon operates using the same technique in different communities, the
outcomes may be different. Care should thus be taken when comparing different
populations with different casemixes before definitive conclusions are made in
comparative studies.
PMID- 10779062
TI - Management of the axilla in early breast cancer: is it time to change tack?
AB - The standard surgical treatment of the axilla in patients with early breast
cancer is about to undergo a radical change. Although axillary dissection is an
excellent procedure for both staging and local control, particularly in the
clinically positive axilla, it has considerable morbidity and may understage a
significant proportion of patients, because it will usually miss micrometastases
that can occur in approximately 10% of 'node negative' patients. An increasing
number of patients whose tumours are either non-invasive (ductal carcinoma in
situ; DCIS), micro-invasive, tubular cancers or low-grade T1a tumours without
lymphovascular invasion may be spared axillary surgery because the risk of
axillary disease is 0-3%. Many studies, both prospective trials and large
retrospective series, show that axillary radiotherapy alone provides similar
local control rates to axillary dissection in patients with clinically negative
axillas. Primary treatment of the axilla with radiotherapy alone, however, does
not allow appropriate staging. Sentinel lymph node biopsy is being increasingly
used in patients with breast cancer to provide this information. When a sentinel
node is identified it is equal to or better than axillary dissection for staging
the axilla and, if the node is positive, it will help select patients who should
then proceed to further axillary surgery or axillary radiotherapy. Although
sentinel lymph node biopsy is being rapidly adopted in many centres worldwide,
the results of randomized controlled trials are needed before it can be
recommended as the standard of care.
PMID- 10779061
TI - Thyroid pathology associated with primary hyperparathyroidism.
AB - BACKGROUND: Thyroid carcinoma and benign thyroid disease associated with primary
hyperparathyroidism (PHPT) have been well described. With the developing trend
toward minimally invasive parathyroidectomy without intra-operative thyroid gland
palpation, thyroid pathology may be missed. The authors consider it timely to
revisit the issue of thyroid pathology found at neck exploration for PHPT.
METHODS: A retrospective review of all cases of neck exploration for PHPT between
1993 and 1998 at Liverpool Hospital was undertaken. RESULTS: There were 65
patients in the study group (44 women, 21 men; mean age: 59 years). The most
common indication for surgery was asymptomatic hypercalcaemia. The mean pre
operative calcium level was 2.9 mmol/L and the mean parathyroid hormone (PTH)
level was 17 pmol/L. There were 26 cases (40%) of coexistent thyroid pathology.
Ten cases (15%) were of mild multinodular change, seven cases (11%) were of
severe multinodular change requiring thyroidectomy, three cases (4%) were nodules
secondary to Hashimoto's thyroiditis and six cases (10%) were suspicious nodules
that proved to be either adenomas (n = 3) or carcinomas (n = 3) following
excision. There were four papillary carcinomas detected in the present series
with a mean metastases, age, completeness of excision, invasion size (MACIS)
score of 4.92. CONCLUSION: A 25% association of significant thyroid pathology
with PHPT is reported. Despite pre-operative tests there were two cases (4%) of
thyroid carcinoma where the decision to resect the thyroid gland was made
following intra-operative thyroid gland palpation. One of these two papillary
carcinoma patients would have fulfilled criteria for minimally invasive
parathyroid surgery. When evaluating results of minimally invasive parathyroid
surgery one must be aware of the potential for missed thyroid pathology.
PMID- 10779063
TI - Grantsmanship: achieving success in research funding.
AB - High-quality research is seldom feasible without skillful grantsmanship. Like
most skills it is learnt and then improved by practice. Fortunately, there is a
consistent formula to constructing a research grant, provided certain guidelines
are followed. The grant application need not be a significant barrier between a
good idea and its realization in improvements to patient care. This paper
outlines the essential principles in the construction of the successful research
grant application.
PMID- 10779064
TI - Progress of surgical training in Papua New Guinea to the end of the 20th century.
AB - BACKGROUND: Health care in Papua New Guinea (PNG) throughout the 20th century has
been characterized by a significant shortage of medical practitioners and
surgical expertise. A number of initiatives within the country and from outside
have sought to address these deficiencies of numbers and quality. The present
paper seeks to review the development of surgery and surgical training in PNG.
METHODS: Review of the surgical literature, reports and records in the Division
of Surgery at the University of Papua New Guinea (UPNG), and personal
observations are used to look critically at the content and productivity of the
various training initiatives. RESULTS: For the first half of the century, PNG
relied on national medical assistants who were trained, supervised and directed
by expatriate doctors. Medical training of PNG doctors began in 1951 and by 1999
more than 600 doctors had graduated. Expatriate specialist surgeons arrived in
1950 and were the only surgeons until the postgraduate Master of Medicine
(surgical) programme produced its first graduates in 1978. This programme has now
produced 37 surgeons who are reasonably well distributed throughout the country.
Higher surgical diplomas were introduced in 1994 for more specialized training of
some of the general surgeons. These training developments have been supported by
AusAid as well as by Australian surgeons. CONCLUSIONS: Surgical expertise has
progressively improved throughout the 20th century with the most major advances
being achieved in the last decade. Training programmes have provided an expanding
core of expertise of considerable quality, but the numbers of doctors and
surgeons remain well below requirements.
PMID- 10779065
TI - Intussusception in coeliac disease: a little-known association.
PMID- 10779066
TI - Urethral carcinoma: an unusual cause of peri-urethral abscess.
PMID- 10779067
TI - Metastatic malignant fibrous histiocytoma: a rare cause of small bowel
intussusception.
PMID- 10779068
TI - The role of liposomes in drug delivery and diagnostic imaging: a review.
AB - This manuscript is not intended as a comprehensive overview of the large filed of
liposome technology and all its applications. However, our intent was to present
current data, which are active, cutting-edge research. Because of their unique
properties liposomes will continue to be investigated in drug delivery and
imaging systems, and very likely will be incorporated into our discipline of
veterinary medicine as the clinical applications of liposomes continue to expand.
PMID- 10779069
TI - Use of radiography, computed tomography and magnetic resonance imaging for
evaluation of navicular syndrome in the horse.
AB - Radiographic evaluation of navicular syndrome is problematic because of its
inconsistent correlation with clinical signs. Scintigraphy often yields false
positive and false negative results and diagnostic ultrasound is of limited
value. Therefore, we assessed the use of computed tomography and magnetic
resonance imaging in a horse with clinical and radiographic signs of navicular
syndrome. Cadaver specimens were examined with spiral computed tomographic and
high-field magnetic resonance scanners and images were correlated with pathologic
findings. Radiographic changes consisted of bony remodeling, which included
altered synovial fossae, increased medullary opacity, cyst formation and shape
change. These osseous changes were more striking and more numerous on computed
tomographic and magnetic resonance images. They were most clearly defined with
computed tomography. Many osseous changes seen with computed tomography and
magnetic resonance imaging were not radiographically evident. Histologically
confirmed soft tissue alterations of the deep digital flexor tendon, impar
ligament and marrow were identified with magnetic resonance imaging, but not with
conventional radiography. Because of their multiplanar capability and tomographic
nature, computed tomography and magnetic resonance imaging surpass conventional
radiography for navicular imaging, facilitating earlier, more accurate diagnosis.
Current advances in imaging technology should make these imaging modalities
available to equine practitioners in the future.
PMID- 10779070
TI - Distinguishing rhinitis and nasal neoplasia by radiography.
AB - To compare the incidence of radiographic signs in dogs with rhinitis and primary
nasal neoplasia and to assess the performance of observers for distinguishing
these conditions, the nasal radiographs of 72 dogs with either rhinitis (n = 42)
or primary nasal neoplasia (n = 30) were examined by two independent observers
using custom-designed forms to record their interpretations. Rhinitis was
associated with a higher incidence of focal or multifocal lesions, localised soft
tissue opacities, lucent foci, and a lack of frontal sinus involvement. Neoplasia
was associated with soft tissue opacities and loss of turbinate detail that
affected the entire ipsilateral nasal cavity, signs of invasion of the bones
surrounding the nasal cavity, and soft tissue/fluid opacities within the
ipsilateral frontal sinus. The signs with the highest positive predictive value
(PPV) for rhinitis were absence of frontal sinus lesions and lucent foci in nasal
cavity (PPV of each 82%), and invasion of surrounding bones for neoplasia (PPV
88%). There were no significant differences in the position of the lesion within
the nasal cavity, incidence of unilateral versus bilateral lesions, calcified
lesions, or absence of teeth. There was moderate agreement between observers
about the diagnosis (kappa 0.59). Areas (SE) under ROC curves were 0.94 (0.03)
and 0.96 (0.03) for observers A and B, respectively (not significantly different;
P = 0.68). These results indicate a high accuracy for radiologists examining dogs
with nasal diseases. Differentiation of rhinitis and nasal neoplasia should be
based on finding combinations of radiologic signs that together have a high PPV.
Differences in interpretation between experienced observers in this study suggest
that certain signs are potential sources of error.
PMID- 10779071
TI - Computed tomographic findings of dogs with cubital joint lameness.
AB - The purpose of this study was to identify the incidence of abnormal computed
tomography (CT) findings in dogs with lameness of one or both elbows. CT
examinations of 102 elbows in 51 dogs were reviewed individually and by group
consensus by 3 examiners and graded for various abnormalities. Frequently
encountered abnormalities included abnormal shape and sclerosis of the medial
coronoid process of the ulna, irregularity of the radial incisure of the ulna,
and ulnar trochlear notch sclerosis. Other abnormalities included
distinct/separate or fissure/in situ fragmentation of the medial coronoid;
lucency of the radial incisure; ununited anconeal process; sclerosis, lucency, or
flattening of the medial aspect of the humeral condyle; osteophyte formation; and
joint incongruity. In conclusion, CT of the canine cubital joint is useful in
identification of various lesions beyond simple fragmentation of the medial
coronoid process of the ulna.
PMID- 10779072
TI - Low-field magnetic resonance imaging of the equine tarsus: normal anatomy.
AB - The objective of this study was to define the normal gross anatomic appearance of
the adult equine tarsus on a low-field magnetic resonance (MR) image. Six
radiographically normal, adult, equine tarsal cadavers were utilized. Using a
scanner with a 0.064 Tesla magnet, images were acquired in the sagittal,
transverse and dorsal planes for T1-weighted and the sagittal plane for T2
weighted imaging sequences. Anatomic structures on the MR images were identified
and compared with cryosections of the imaged limbs. Optimal image planes were
identified for the evaluation of articular cartilage, subchondral bone, flexor
and extensor tendons, tarsal ligaments, and synovial structures. MR images
provide a thorough evaluation of the anatomic relationships of the structures of
the equine tarsus.
PMID- 10779073
TI - Magnetic resonance, computed tomographic and radiologic findings in a dog with
discospondylitis.
AB - Magnetic resonance (MR), computed tomographic and radiographic imaging were
conducted in a dog with discospondylitis. The MR findings were increased T2 and
decreased T1 signal intensity of the soft tissues ventral to vertebral bodies,
the end plates of the same vertebral bodies and the intervertebral disc, and are
similar to those described in human with discospondylitis.
PMID- 10779074
TI - Radiographic diagnosis--engorged ticks appearing as distinct radiographic
opacities.
PMID- 10779075
TI - Incomplete ossification of the humeral condyle in Vietnamese pot-bellied pigs.
AB - The purpose of this study was to evaluate the occurrence of humeral condylar
fractures in Vietnamese pot-bellied pigs and to postulate a possible predisposing
cause for these fractures. Thirteen Vietnamese pot-bellied pigs (Group A) were
evaluated over an eight year period (1990-1998), each with a history of either a
unilateral or bilateral forelimb lameness. The cause of lameness was localized to
the elbow region. Of the thirteen pigs, twenty-one elbows were evaluated
radiographically. Pigs ranged in age from six months to four years old. All pigs
over the age of seven months showed radiographic evidence of elbow degenerative
joint disease. Fractures involving the medial aspect of the humeral condyle were
identified in 8/21 studies (38%). A well-defined linear intracondylar articular
lucency was identified in 7/21 studies (33%) on the craniocaudal projection. The
site of this lucency corresponded to the location of the articular component of
the fractures seen involving the humeral condyle. The elbows of five pot-bellied
pigs with no known history of forelimb lameness or trauma (Group B) were
evaluated radiographically following euthanasia. All five pigs were of unknown
age and gender. An intracondylar vertical linear lucency was identified
bilaterally in three pigs (60%). Concurrent degenerative joint disease was
present in all instances. The remaining two pigs were radiographically normal.
Computed tomography of the elbows was performed in one affected pig from Group B.
The radiographic findings in this pig were verified. Histopathology of the right
elbow of this affected pig was diagnostic for incomplete endochondral
ossification of the humeral condyle. A similar condition involving the humeral
condyle has been previously described in Cocker and Brittany Spaniels. These
canine breeds also have a high incidence of humeral condylar fractures. It is
postulated that Vietnamese pot-bellied pigs are similarly prone to humeral
condylar fractures, even in the absence of known trauma, due to incomplete
ossification of the humeral condyle.
PMID- 10779076
TI - Non-cardiac thoracic ultrasound in 75 feline and canine patients.
AB - The purpose of this study was to describe the ultrasonographic appearance of non
cardiac diseases of the small animal thorax. Ultrasound images from a total of 75
animals (26 cats and 49 dogs) were compared to cytologic, histopathologic, and
necropsy findings. Clinical diagnoses included neoplasia of the mediastinum,
pleura, or lungs (43); idiopathic mediastinal cyst (3); diaphragmatic or
peritoneopericardial hernia (4); lung lobe torsion (1); pulmonary eosinophilic
infiltrates (1); and idiopathic, chylous, congestive heart failure, or
lymphangiectasia associated pleural effusion (14). In the remaining 9 patients, a
definitive diagnosis was not obtained. Ultrasound-guided fine needle aspirate was
performed in 56 patients; 1 of these also had an ultrasound-guided tissue core
biopsy. Of the fine needle aspirates, 51 (91%) were diagnostic. Ultrasound
examination, particularly when accompanied by guided tissue sampling, can be a
valuable tool in the diagnosis of non-cardiac intrathoracic lesions.
PMID- 10779077
TI - Most dogs with medullary rim sign on ultrasonography have no demonstrable renal
dysfunction.
AB - The medullary rim sign is a distinct hyperechoic line in the renal medulla
parallel to the corticomedullary junction that has been reported in dogs with a
variety of renal diseases. To examine the association between medullary rim sign
and renal disease, the medical records of thirty-two dogs that had medullary rim
sign were reviewed retrospectively. Eighteen dogs (56%) had no evidence of renal
dysfunction; 14 (44%) had clinicopathological evidence of renal disease,
including 6 (19%) that had hypercalcemic nephropathy. Most dogs (72%) in which
medullary rim sign was the only ultrasonographic finding affecting the kidneys
had no evidence of renal dysfunction. In contrast, 78% dogs that had medullary
rim sign and other renal signs (reduced size, increased medullary echogenicity,
and pyelectasia) had renal disease. On the basis of this study, the medullary rim
sign appears to be a non-specific ultrasonographic sign; however, the possibility
cannot be excluded that is a sentinel sign of subclinical renal disease.
PMID- 10779078
TI - Duplex-ultrasonographic evaluation of the common carotid artery in the resting,
sedated and anesthetized horse.
AB - The aim of this study was to determine the blood flow in the carotid artery
during halothane anaesthesia by means of duplex-sonography. Seventeen warm blood
horses were evaluated in dorsal and lateral recumbency and the results were
compared with the values of the same horses resting and under sedation. The cross
sectional area of the vessels, the time-averaged maximal blood velocity, time
averaged maximal blood flow and the resistance index were determined and the flow
profile was evaluated. During halothane anesthesia the total blood flow shows a
significant increase which is not dependent on the positioning of the horse. Mean
blood velocity is decreased by sedation and significantly increased during
anesthesia. Reduced peripheral resistance is expressed by a decline of the
resistance index. After sedation and during recumbency there is an increase in
diameter of the carotid artery.
PMID- 10779079
TI - Non-invasive diagnosis of ischemic brain damage after cardiopulmonary
resuscitation in dogs by using transcranial Doppler ultrasonography.
AB - We have attempted to identify whether it is possible to utilize transcranial
Doppler ultrasonography to evaluate the brain damage that occurs after
resuscitation from 3 min (control group) and 12 min (damage group) of cardiac
arrest in dogs. In this study we used transcranial Doppler ultrasonography to
follow the basilar arterial flow and middle cerebral arterial flow for 180 min
following the induction of cardiac arrests. Two abnormal waveform patterns (the
"to-and-fro" and "diastolic no-flow" patterns) were found in all dogs in the
damage group whereas abnormal waveforms were not detected in the control group.
Pathological diagnosis revealed that, compared with the control group, the damage
group recognized ischemic alteration at the level of the hippocampus and caudate
nucleus. In conclusion, this study shows that the basilar arterial flow of
observed with transcranial Doppler ultrasonography may be use for the prediction
of outcome and the diagnosis of brain damage in the dog.
PMID- 10779080
TI - Measuring sphere-like structures using transrectal ultrasonography.
AB - Sphere-like structures are commonly measured for clinical or research purposes.
We measured two diameters, the circumference (perimeter) and cross sectional area
of 113 equine ovarian follicles in a water bath then determined the relationships
between those measurements and the actual volume of fluid in the follicles. Cross
sectional area, diameter3 and area2/3 were all highly correlated with the volume
of the structures and superior (p < 0.05) to diameter or perimeter as predictors
of volume. As predictors of volume, there was no significant difference (p >
0.05) between cross-sectional area, diameter3, and area2/3. Because of the ease
of measuring diameter, we suggest that diameter3 be used to estimate the actual
size of sphere-like structures by ultrasonographic measurement. A table was
generated for clinical use to show how much the largest diameter of a fluid
filled structure (follicle, cyst, hematoma, etc.) would have to increase or
decrease to indicate a significant change in the volume of the structure.
PMID- 10779081
TI - Scintigraphic characterization of distal radial physeal closure in young
Standardbred racehorses.
AB - A longitudinal scintigraphic and radiographic study of distal radial physeal
activity in 14 Standardbred trotters was conducted to quantify and visually
evaluate physeal uptake around the time of physeal closure. Initial intense 99mTc
HDP uptake was seen, followed by a rapid decrease of activity starting at a mean
age of 20 months. Mean physeal to distal diaphyseal ROI and line profile ratios
compared to ratios of mature horses decreased from 2.8 to 1.4 at the time of
radiographic closure at 24-32 months. Ratios then gradually decreased until
values of mature horses were reached at the end of the study (mean age 42
months). Visually discernible distal radial physeal activity was present with
declining frequency throughout the study. This study indicates that, in the
normal Standardbred trotter, there is mild distal radial physeal uptake present
after radiographic evidence of physeal closure. This uptake is not likely to
confound evaluation of pathologic conditions of the physeal or carpal regions.
PMID- 10779082
TI - Dr. W. Harker Rhodes: Recipient of the ACVR Distinguished Service Award. American
College of Veterinary Radiology.
PMID- 10779083
TI - Targeting of the renin-angiotensin system by antisense gene therapy: a possible
strategy for the long-term control of hypertension.
AB - Traditional pharmacological agents have been successfully used for the treatment
of hypertension for a number of decades. However, this therapeutic regimen has
reached a conceptual plateau and a cure for the disease is far from appearing on
the horizon. With this in mind, and recent advances in state of the art gene
delivery system coupled with the anticipated completion of the human genome
project, it is timely to think about the possibility of treating and/or curing
hypertension using genetic means. In this review, we discuss the role of renin
angiotensin system (RAS) in hypertension; the current gene delivery/gene transfer
systems and the RAS as a target for gene therapy to treat hypertension; the
successful use of retroviral vectors to deliver antisense to the AT1 receptor
(AT1-AS) to prevent the development of hypertension and cardiovascular
pathophysiology; the potential use of the viral vectors for the reversal of
hypertension; and the future of antisense gene therapy and potential advantages
and limitations of this regimen in the treatment and/or control of hypertension.
PMID- 10779084
TI - Impaired endothelial function in arterial hypertension and hypercholesterolemia:
potential mechanisms and differences.
AB - This review focuses on the role of impaired endothelial function for the
development of atherosclerosis in human arterial hypertension and
hypercholesterolemia in vivo. Potential mechanisms underlying impaired
endothelial function and decreased bioavailability of nitric oxide under these
clinical conditions are discussed and potential differences in these mechanisms
between arterial hypertension and hypercholesterolemia are outlined. It further
addresses therapeutic strategies aiming to improve the bioavailability of nitric
oxide in these patients. The overall conclusion is that the bioavailability of
nitric oxide is probably impaired not by a single defect, but by various
mechanisms affecting nitric oxide synthesis as well as nitric oxide breakdown. In
both diseases, increased superoxide anion production and oxidative stress
represents a major mechanism. However, potential differences in the underlying
mechanisms of superoxide production or nitric oxide synthesis are evident between
arterial hypertension and hypercholesterolemia. Decreased bioavailability of
nitric oxide does not only impair endothelium-dependent vasodilation, but also
activates other mechanisms that play an important role in the pathogenesis of
atherosclerosis. Thus, therapeutic strategies should aim to restore
bioavailability of nitric oxide, which has been demonstrated for lipid-lowering
therapy in hypercholesterolemia. The mechanisms by which nitric oxide
bioavailability can be improved by any drug therapy remain to be elucidated and
may provide further insights into the mechanisms that are involved in impaired
endothelial function and atherogenesis.
PMID- 10779085
TI - The debate on the amplifier hypothesis' - some comments.
PMID- 10779086
TI - Direct and surrogate measures of the white-coat effect: methodological aspects
and clinical relevance.
PMID- 10779087
TI - Difference between office and ambulatory blood pressure or real white coat
effect: does it matter in terms of prognosis?
AB - OBJECTIVE: The blood pressure (BP) response to the doctor's visit, generally
referred as the white coat (WC) response, is usually estimated by the difference
between office BP (OBP) and ambulatory BP (ABP). The purpose of this study was to
determine the validity of this estimation. To that end, we compared the real WC
effect and the estimated WC effect (OBP-ABP) in terms of magnitude and
consequences on target organs. DESIGN: The study comprised 88 patients referred
for hypertension. The real WC effect was measured using a Finapres device and
expressed as the maximal WC effect (Max WC) or the average WC effect (Aver WC).
For the estimation of target organ damages, the whole hypertensive group was
separated into two groups according to the medians of the Aver WC, the Max WC,
and the estimated WC effects, successively. Left ventricular mass index, E to A
mitral wave ratio and pulse wave velocity were compared between groups as were
serum creatinine, cholesterol and glucose levels. RESULTS: The estimated WC
effect proved to be a bad index of the real response to the doctor's visit as
assessed by their difference of magnitude between the two (20 +/- 17, 12 +/- 12
and 30 +/- 14 mmHg as estimated WC, Aver WC and Max WC effects, respectively),
their loose correlations (r=0.31, P=0.004 between estimated WC and Aver WC
effects; r=0.27, P=0.01 between estimated WC and Max WC effects), and finally by
the fact that they were in agreement in less than two-thirds of the patients for
the categorization of the WC response. Concerning target organ damages, no
difference in terms of cardiac mass, diastolic function, arterial distensibility,
renal function and cardiovascular risk profile could be discerned between the
groups with a high and a low WC effect, either real or estimated, when age and
ABP were taken into account. CONCLUSION: The present work supports the view that
the true WC effect and its estimation are not equivalent. However, the way in
which the WC response is defined does not alter its effect on target organs or
cardiovascular risk profile.
PMID- 10779088
TI - Comparison of nurse- and physician-determined clinic blood pressure levels in
patients referred to a hypertension clinic: implications for subsequent
management.
AB - BACKGROUND: When measuring BP, the physician induces a transient pressor response
triggered by an alarm reaction. This 'white-coat effect' can influence
therapeutic decisions. Whether it depends on the characteristics of the physician
has not been evaluated. OBJECTIVE: To assess the 'white-coat effect' induced by
several physicians in a large sample of patients, using the blood pressure
measured by trained nurses as a reference. SETTING: Referral hypertension clinic.
METHODS: Patients were selected for the study if they had been referred for the
first time to the clinic and if they had had their supine systolic/diastolic
blood pressure measured by a trained nurse (mean of the last two of three
measurements taken every 1 min by an oscillometric device) and a physician
(auscultatory method using a standard mercury sphygmomanometer). Physicians were
included in the study provided they had seen at least 25 patients during the
study period. The between-physician difference was assessed using linear
regression analysis. Physician blood pressure was the dependent and nurse blood
pressure was the independent variable. RESULTS: From 1 January 1997 to 15
September 1997, 1062 patients (50% male, aged 52 +/- 14 years), seen by 10
physicians (26-187 patients per physician) and one nurse were included for
analysis. The mean systolic/diastolic blood pressure for physicians was 162 +/-
27/ 97 +/- 15 mmHg and that for the nurse was 155 +/- 24/ 88 +/- 14 mmHg. The
nurse-physician differences were -6 mmHg (range -67 to +66) for systolic and -8
mmHg (-44 to +31) for diastolic blood pressures. Major differences were observed
between individual physicians. Intercepts of the physician blood pressure versus
nurse blood pressure relationship ranged from 0.1 -60.7 mmHg for systolic and
from 13.3-55.3 mmHg for diastolic pressures. The slopes of this relationship
differed less between physicians for systolic (0.72-1) than for diastolic
pressures (0.56-0.97). There was no difference between the patients seen by
physicians in patients' age, sex, tobacco consumption, anti-hypertensive
treatment or target-organ damage. CONCLUSION: Large between-physician differences
exist in the magnitude of the white-coat effect that cannot be explained by
patient characteristics. Physicians should therefore not make any decisions based
on blood pressure measured manually during a first encounter.
PMID- 10779089
TI - Increased blood pressure response to the cold pressor test in pregnant women
developing pre-eclampsia.
AB - OBJECTIVES: Recent data indicate an increased vascular reactivity due to an
overactivity of the sympathetic nervous system in women with pre-eclampsia. We
therefore evaluated whether this increased vascular reactivity can be detected
prior to the clinical manifestation of preeclampsia by the use of a physiological
stimulus. DESIGN: Prospective data collection. SETTING: Clinic of Obstetrics and
Gynecology in a 2000 bed tertiary care hospital. PARTICIPANTS: One hundred and
twenty-three pregnant women between the 16th to 20th week of gestation.
INTERVENTIONS: A cold pressor test was performed by positioning an ice-bag on the
forehead of the woman for 3 min. Blood pressure and heart rate were monitored by
a continuous, noninvasive blood pressure measurement device during the stimulus
and after removal of the icebag. A clinical follow-up was carried out by review
of the charts after delivery to identify those women who have developed pre
eclampsia. RESULTS: Ten (8%) out of 123 pregnant women developed pre-eclampsia.
During the cold pressor test systolic as well as diastolic blood pressure
increased significantly and was more pronounced in women developing pre-eclampsia
compared with healthy pregnant women (systolic blood pressure: 14.2 +/- 5.5
versus 8.5 +/- 7.2 mmHg, P= 0.02; diastolic blood pressure: 7.3 +/- 4.9 versus
3.9 +/- 4.7 mmHg, P=0.03). The change in heart rate was similar between both
groups (8 +/- 2.6 versus 10.4 +/- 6.4 beats/min, not significant). CONCLUSIONS:
An increased vasoconstrictive response to a physiological stimulus is present in
women with pre-eclampsia as a sign of an increased vascular reactivity prior to
clinical manifestation of the disease. The cold pressor test may be a suitable
diagnostic tool to identify women, who will develop pre-eclampsia. However,
future studies in larger cohorts are required to establish the final value of
this test.
PMID- 10779090
TI - Physical activity level is an independent predictor of the diurnal variation in
blood pressure.
AB - OBJECTIVE: The aim of this study was to define the relationship between physical
activity and the magnitude of the percentage fall in blood pressure at night
(nocturnal dip). METHODS: We simultaneously monitored 24-h ambulatory blood
pressure and measured physical activity by actigraphy in 434 patients. Blood
pressure was measured every 20 min; the actigraph integrated an activity score
every 10 s. Mean daytime and night-time activity were calculated from mean scores
for the 15 min preceding each blood pressure measurement. Nocturnal dip in
systolic and diastolic blood pressure (SBP and DBP) were regressed on mean (log
transformed) daytime activity. Mean night-time activity, age, gender, smoking
status, body mass index (BMI) and clinic blood pressure were added into a
multiple linear regression. RESULTS: The patient group was heterogeneous in age,
gender and mean 24-h blood pressure. Mean daytime activity level was
significantly and positively associated with the magnitude of the nocturnal dip
in both SBP and DBP. Increased night-time activity was significantly associated
with a smaller nocturnal dip. Older patients had a smaller nocturnal dip per log
unit daytime activity. Nocturnal dip in SBP was greater in males, and smaller in
those taking antihypertensive medications. Smoking, BMI and clinical blood
pressure level were not associated with the extent of the nocturnal dip after
adjustment for other factors. CONCLUSIONS: Daytime and night-time physical
activity levels are independently and significantly predictive of the magnitude
of the nocturnal dip in blood pressure. Variation in activity may confound
interpretation of 24-h ambulatory blood pressure monitoring, and contribute to
the poor reproducibility of dipper status.
PMID- 10779091
TI - Effect of vitamin C on ambulatory blood pressure and plasma lipids in older
persons.
AB - OBJECTIVES: To determine the effect of oral vitamin C supplements on ambulatory
blood pressure and plasma lipids. DESIGN: A 6-month double-blind randomized
placebo-controlled cross-over study with a 1 -week washout between cross-over
periods. METHODS: Vitamin C 500 mg daily or matching placebo was given to 40 men
and women aged between 60 and 80 years for 3 months each in a cross-over fashion.
Clinic and 24-h ambulatory blood pressure, plasma ascorbate and lipids were
measured at baseline and at the end of each cross-over phase. RESULTS: Clinic
blood pressure did not change between placebo and vitamin C phases. Daytime
ambulatory blood pressure showed a small but significant fall in systolic blood
pressure (2.0 +/- 5.2 mmHg; 95% confidence interval 0-3.9 mmHg) but not in
diastolic blood pressure. Regression analysis showed that with increasing
baseline daytime blood pressure the fall in blood pressure with vitamin C
supplementation increased. Regression analysis of the change in high-density
lipoprotein (HDL) cholesterol showed a significant effect of sex on the change in
HDL cholesterol. In women, but not men, HDL cholesterol increased significantly
by 0.08 +/- 0.11 mmol/l, P=0.007. There was no change in low-density lipoprotein
cholesterol between treatment periods. CONCLUSION: In older adults high intakes
of ascorbic acid have modest effects on lowering high systolic blood pressure,
which could contribute to the reported association between higher vitamin C
intake and lower risk of cardiovascular disease and stroke.
PMID- 10779092
TI - Excess mortality associated with increased pulse pressure among middle-aged men
and women is explained by high systolic blood pressure.
AB - OBJECTIVE: To assess the risk of death from coronary heart disease, stroke, all
cardiovascular diseases and all-cause mortality associated with pulse pressure
among the middle-aged population. METHODS AND DESIGN: A prospective 15-year
follow-up cohort study was conducted of two independent cross-sectional random
samples of the population who participated in baseline surveys in 1972 or 1977.
Each survey included a self-administered questionnaire with questions on smoking
and antihypertensive drug treatment, measurements of height, weight and blood
pressure and the determination of the serum cholesterol concentration.
Multivariate analyses were performed by using Cox proportional hazard models.
SETTING: The provinces of North Karelia and Kuopio in eastern Finland
PARTICIPANTS: Men and women aged 45-64 years with no history of myocardial
infarction or stroke at the time of the baseline survey were selected. In total
4333 men and 5270 women took part in this follow-up study. RESULTS: The relative
risk of coronary heart disease, stroke, cardiovascular disease and all-cause
mortality increased with the increasing pulse pressure in individuals aged 45-64
years independent of the diastolic blood pressure level. Only in women with
diastolic blood pressure > or = 95 mmHg was the relative risk of fatal stroke not
statistically significant. After adjustment for systolic blood pressure, the
positive association between mortality and increasing pulse pressure disappeared.
CONCLUSION: Increasing pulse pressure is a predictor of death from coronary heart
disease, stroke, cardiovascular disease and all causes in men and women aged 45
64 years, but the increase in risk is entirely associated with the increase in
systolic blood pressure.
PMID- 10779093
TI - High-normal serum homocysteine concentrations are associated with an increased
risk of early atherosclerotic carotid artery wall lesions in healthy subjects.
AB - OBJECTIVE: Moderate hyperhomocysteinaemia is common in the general population and
has been linked with systemic atherosclerotic vascular disease. We studied the
relation of sonographically determined carotid intima-media wall thickness to
serum homocysteine concentrations in asymptomatic, healthy subjects. METHODS AND
RESULTS: Seventy-five male and female untreated subjects (mean age 49 years,
range 22-75) with normal serum folate concentrations were included. High
resolution duplex sonography was used to determine intima-media thickness of the
common carotid artery. Serum homocysteine concentration was measured by high
performance liquid chromotography with fluorescence detection. Mean intima-media
thickness (+/- SD) was 0.78 +/- 0.19 mm (range 0.5-1.35) and mean serum
homocysteine concentration was 10.5 +/- 2.81 micromol/l (range 5.7-19.6). In
stepwise regression models, statistically significant predictors of intima-media
thickness included age, body mass index, LDL cholesterol and homocysteine (R2 =
0.51). Homocysteine concentration was independently associated with intima-media
thickness after adjustment for the other variables (P < 0.001) and explained an
additional 18% of the variation of intima-media thickness. CONCLUSIONS: In
healthy subjects, high-normal serum homocysteine concentrations are associated
with an increased prevalence of carotid artery wall thickening. The significance
of the contribution of homocysteine to the variation of carotid intima-media
thickness, even at concentrations previously believed to be normal, suggests a
role for homocysteine as an independent risk factor for early carotid artery
atherosclerosis in the asymptomatic subjects.
PMID- 10779094
TI - Association between the apolipoprotein E polymorphism and arterial wall thickness
in asymptomatic adults.
AB - OBJECTIVES: The polymorphism of the apolipoprotein E gene (epsilon2, epsilon3,
epsilon4) affects plasma cholesterol but the relationship with artery wall
thickness has indicated contradictory results. This study investigated the
relationship between apolipoprotein E polymorphism and vascular phenotypes of the
carotid and radial arteries, two arterial sites differently affected by
atherosclerosis. METHODS: We studied a cohort of 320 Caucasian subjects (age 49
+/- 12 years) without evidence of cardiovascular disease. Structural (internal
diameter and wall thickness) and functional phenotypes (compliance,
distensibility) were evaluated for the common carotid and the radial arteries
using high resolution echo-tracking devices. Genotypes of apolipoprotein E were
determined by allele-specific oligonucleotides hybridization. Because of the
relative low frequency of some apolipoprotein E genotypes, they were designated
as E2 (epsilon2/epsilon2, epsilon2/epsilon3), E3 (epsilon3/epsilon3), and E4
(epsilon4/epsilon4, epsilon3/epsilon4). RESULTS: Apolipoprotein E allele
frequencies were epsilon2 = 0.08, epsilon3 = 0.79, epsilon4 = 0.13. Subjects with
epsilon4 allele had the highest levels of total serum cholesterol and low density
lipoprotein cholesterol; subjects with epsilon2 allele had the lowest levels (P <
0.001). Considering carotid hypertrophy as intima-media thickness > 660 microm,
and radial hypertrophy as intima-media thickness > 260 microm, a logistic
regression model testing determinants of arterial hypertrophy (age, gender,
weight, systolic blood pressure, smoking habits, and total serum cholesterol)
observed a significant and positive association between carotid hypertrophy and
epsilon2 allele carriers (P= 0.03). In contrast, no association was found between
hypertrophy and apolipoprotein E genotypes for the radial artery. No association
was observed between the apolipoprotein E genotypes and functional artery
parameters. CONCLUSIONS: In subjects without any evidence of cardiovascular
disease, the presence of the epsilon2 allele is related to wall hypertrophy in
carotid artery despite favourable effect on the lipid profile.
PMID- 10779095
TI - Headache in patients with mild to moderate hypertension is generally not
associated with simultaneous blood pressure elevation.
AB - OBJECTIVE: Although headache is regarded a symptom of hypertension, its relation
to blood pressure, especially in mild and moderate hypertension, is not clear.
Thus, the aim of the study was to investigate whether headache in patients with
mild to moderate hypertension may be attributed to simultaneous elevations in
blood pressure. DESIGN AND METHODS: Ambulatory blood pressure monitoring (ABPM)
was performed in patients (mean age 48 +/- 10 years, n = 150, 92 men, 58 women)
classified, according to their office blood pressure, as stage 1 -2 hypertensives
(JNC VI). Headache periods were recorded in patients' diaries. RESULTS: Headaches
were generally not directly associated with blood pressure elevations in the
studied group of stage 1-2 hypertensive patients because (i) blood pressure
values from headache periods were not significantly higher than those from
headache-free periods; (ii) blood pressure values directly preceding the pain
were not significantly different from values at the beginning of headache; and
(iii) in the vast majority of hypertensives, their maximal blood pressure values
were recorded during headache-free periods. Moreover, in some instances, patients
who showed maximal ABPM values during headache had relatively high blood
pressure, i.e. > or = 180/110 mmHg. CONCLUSIONS: Our results did not support the
opinion that headache experienced by stage 1-2 hypertensives was generally caused
by simultaneous elevation in blood pressure. The direct mechanisms of headache in
hypertension, as well as the relation between increments in blood pressure above
180/110 mmHg and headache, need further investigations.
PMID- 10779096
TI - Cardiac hypertrophy depends upon sleep blood pressure: a study in rats.
AB - OBJECTIVE: The objective of this study was to determine whether cardiac
hypertrophy in hypertensive rats could be reduced and normalized by intermittent
reduction of blood pressure, and to determine whether left ventricular
hypertrophy was related to 24 h workload or peak blood pressure responses.
METHODS: Hypertension was created by the application of a 0.20 mm clip to the
left renal artery. Blood pressure response was monitored using a telemetry system
(Data Science International). Blood pressure was reduced for varying periods of
the day by giving different doses of captopril in the drinking water or by intra
peritoneal administration. Cardiac size was measured by weighing the ventricles
and factoring by the body weight to obtain a cardiac index. RESULTS: Captopril 75
mg/kg per day and 25 mg/kg per day in the drinking water administered between
1800 and 2000 h lowered the 24 h blood pressure more than captopril 15 mg/kg per
day or 5 mg/kg per day intra-peritoneally given at 0800 h. Captopril 75 mg/kg per
day and captopril 15 mg/kg per day (intra-peritoneal) caused regression of
cardiac hypertrophy whereas the other doses had no effect The best predictor of
the cardiac hypertrophy response was the blood pressure between 0800 and 1200 h
(i.e. the sleeping blood pressure). Twenty-four hour cardiac work did not
correlate with the response. CONCLUSION: Cardiac hypertrophy can be reduced by
intermittent treatment of elevated blood pressure. It is also caused by
intermittent elevation of blood pressure. It appears that the crucial factor is
when these alterations in blood pressure take place. An elevated blood pressure
during the sleeping hours causes left ventricular hypertrophy, whereas a normal
blood pressure during the sleeping hours allows reduction. It is suggested that
acute wall stress is the signal to initiate the events that lead to cardiac
hypertrophy but this only occurs if the hormonal milieu is appropriate.
PMID- 10779097
TI - Early impairment of coronary flow reserve and increase in minimum coronary
resistance in borderline hypertensive patients.
AB - OBJECTIVE: To evaluate relations between coronary flow velocity and myocardial
oxygen demand at rest, as well as coronary vasodilator capacity and flow reserve,
in asymptomatic subjects with borderline hypertension as compared to normotensive
controls and patients with sustained high blood pressure (HBP) and without left
ventricular hypertrophy (LVH). SUBJECTS AND METHODS: Forty-two asymptomatic males
were studied: 13 healthy normotensive volunteers; 12 subjects with borderline HBP
and 17 asymptomatic subjects with sustained systemic hypertension. Coronary flow
velocity in left anterior descending artery and coronary flow reserve were
assessed by transesophageal echo-doppler at baseline and during intravenous
adenosine infusion. Left ventricular mass, peak systolic wall stress (PSWS; Pa),
and midwall fractional shortening (MFS; %) were obtained from M-mode images of
the left ventricle in transthoracic long-axis view and in transesophageal
transgastric view. RESULTS: Coronary flow velocity at baseline was not
significantly different in the three groups, despite significantly higher rate
pressure product (RPP) in the hypertensive groups as compared with controls. Only
in control subjects, was resting coronary flow velocity significantly correlated
with RPP (y = 4279 + 200x, r = + 0.58, P < 0.05) and PSWS (y = 17.2 + 5.1 x, r =
+ 0.62, P < 0.05). Coronary reserve was 3.5 +/- 0.65 in controls and
significantly lower (P < 0.05) in borderline hypertensive (2.87 +/- 0.46) and in
sustained hypertensive subjects (2.66 +/- 0.56). Minimum coronary resistance was
significantly increased in both hypertensive groups (1.30 +/- 0.29 and 1.39 +/-
0.48 mmHg/s per cm) as compared to normotensive controls (0.93 +/- 0.20 mmHg/s
per cm, P < 0.01). CONCLUSIONS: In asymptomatic subjects with borderline
hypertension and without LVH, a significant reduction in coronary flow reserve is
already detectable and appears almost entirely related to an impaired coronary
vasodilator capacity rather than to an increased myocardial oxygen demand.
PMID- 10779098
TI - QT dispersion and hypertensive heart disease in the elderly.
AB - AIM: To determine the predictors and risk of increased QT dispersion in the
elderly hypertensive patients. METHODS: A 12-lead electrocardiogram (ECG), M-mode
echocardiography and ambulatory blood pressure as well as Holter monitoring were
performed for 67 patients over 60 years of age with essential hypertension (I and
II(o) WHO). The presence of ischaemic changes on ECG was evaluated based on the
Minnesota Code. QT intervals were corrected with Bazett's formulae and QT
dispersion was determined as the difference between maximal and minimal QTc
intervals. Interventricular septal thickness (IVSTd), left ventricular internal
diameter (LVDd) and posterior wall thickness (PWTd) were measured and left
ventricular mass index (LVMI) was calculated. Subjects were divided according to
the median of QTc dispersion (0.10 s). The differences between groups were
assessed using chi-squared and Student's t-test. RESULTS: Subjects with increased
QTc dispersion did not differ from those with low QTc dispersion when age, gender
and body mass index were analysed. Similarly, the average systolic blood
pressure, diastolic blood pressure and blood pressure variability were comparable
in both groups. The mean QTc interval was similar in both groups. In patients
with increased QT dispersion, left ventricular hypertrophy (LVH) and ischaemic
changes on ECG were more frequently recognized (respectively 41.2 versus 18.2%, P
< 0.001; 47.1 versus 21.2%, P < 0.05). Moreover, these subjects presented a
significantly greater number of premature ventricular beats (317.1 +/- 665.6
versus 64.88 +/- 188.6, P < 0.05) and higher classes of Lown's arrhythmia scale
(classes III-IV, 23.35% versus 9.1%). LVMI was insignificantly higher in the
group with greater QTc dispersion (165.82 +/- 54.5 versus 145.07 +/- 36.47 g/
m2). Other echocardiographic indices of LVH were similar in both groups. On the
other hand, the analysis of regression indicated positive correlation between the
dispersion of QTc interval and thickness of left ventricle walls (for IVSd - r =
0.37; for PWd - r = 0.31), relative wall thickness (r = 0.28) and LVMI (r =
0.28). CONCLUSIONS: QTc dispersion is increased in the elderly hypertensive
individuals, with the presence of LVH and myocardial ischaemia on ECG. These
patients are more likely to demonstrate severe ventricular dysrhythmias.
PMID- 10779099
TI - Insulin-stimulated cardiac glucose uptake is impaired in spontaneously
hypertensive rats: role of early steps of insulin signalling.
AB - OBJECTIVE: Although the heart is one of the target organs of insulin, it is still
unknown whether the effect of insulin on cardiac muscle is preserved in essential
hypertension, where insulin resistance has been observed in skeletal muscle.
METHODS: We evaluated cardiac glucose uptake and the early steps of insulin
signalling in spontaneously hypertensive (SHR, 10-12 weeks old) and in age
matched normotensive Wistar-Kyoto (WKY) rats. Cardiac glucose uptake
(micromol/100 g per min) was assessed by 2-[14C]deoxyglucose method. After an
overnight fast, 16 WKY rats and 17 SHR underwent a hyperinsulinemic euglycemic
clamp. In particular, 2-h intravenous (i.v.) infusion of insulin (10 mU/kg per
min) or saline (NaCl 0.9%) was administered, followed by an i.v. bolus injection
of 2-[14C]deoxyglucose (100 microCi/kg) to measure cardiac glucose uptake.
RESULTS: During saline infusion, cardiac glucose uptake was significantly higher
in SHR compared to WKY rats (85 +/- 18 versus 8 +/- 3 mg/kg per min, P < 0.01).
Furthermore, insulin was able to markedly increase cardiac glucose uptake in WKY
rats whereas this insulin action was entirely abolished in SHR; thus, the cardiac
glucose uptake became similar in the two rat strains (76 +/- 16 versus 82 +/- 16
mg/kg per min, not significant). More importantly, during saline infusion SHR
showed a significantly higher phosphorylation of insulin receptor substance-1
(IRS-1) coupled to enhanced association of the p85 subunit of
phosphatidylinositol 3-kinase (PI 3-kinase) to IRS-1 and to an increased PI 3
kinase activity compared to WKY rats. As expected, insulin exposure evoked an
activation of its signalling cascade in WKY rats. In contrast, in SHR, the
hormone failed to activate post-receptor molecular events. CONCLUSIONS: Our data
indicate that the heart of SHR shows an overactivity of the proximal steps of
insulin signalling which cannot be further increased by the exposure to the
hormone. This abnormality may account for the marked increase of basal cardiac
glucose uptake and the loss of insulin-stimulated glucose uptake observed in SHR.
PMID- 10779100
TI - Endothelin-1 inactivating peptidase in the human kidney and urine.
AB - OBJECTIVE: Recently, an apparently novel, specific endothelin-1 inactivating
metalloendopeptidase (ET-1 peptidase) has been isolated from the rat kidney. In
this study we attempted to determine whether the same or a similar peptidase is
present in the human kidney, and whether the enzyme is excreted into the urine.
The urinary ET-1 peptidase could serve as an indirect index of the renal
endothelin system, both in physiology and pathophysiology. METHODS: Kidney
specimens were obtained from part of nephrectomized kidneys unaffected by any
neoplastic process from six adult patients. The enzyme was purified using
differential centrifugation, detergent solubilization of the membrane proteins,
ultrafiltration and nondenaturing gel electrophoresis. The enzyme activity assays
were performed at pH 5.5 and 37 degrees C in the presence of increasing
concentrations of unlabelled peptides and inhibitors using a fixed amount of
[125I]ET-1 as substrate. The degradation extent was quantified with
trichloroacetic acid precipitation and high performance liquid chromatography.
The degrading activity of ET-1 was determined in urine samples from adult
patients with hypertension, children with chronic renal failure and those with
stable renal allograft RESULTS: ET-1 peptidase from the human kidney displays
characteristics close to that of the rat ET-1 peptidase we have recently
described (J. Hypertens 1994; 12:1155-1162). The enzyme, a membrane-bound
metalloendopeptidase, exhibits low electro- phoretical mobility on nondenaturing
gel (Rf 0.08); it is an apparently heterologous structure comprising three
enzymatically inactive subunits, it has a pH optimum at 5.5, a nanomolar range
affinity to the ET-1 (KM 180 nmol/l) that is hydrolysed to two main degradation
products, and a 10-100-fold lower affinity to big ET-1 (KM 11.5 micromol/l),
endothelin 11 21 fragment (KM 15.3 micromol/l), endothelin antagonist Trp-Leu-Asp
Ile-Ile-Trp (KM 3.1 micromol/I), gastrin (KM 2.2 micromol/l) and cholecystokinin
(KM 4.0 micromol/l). Substance P, neuropeptide Y, atrial natriuretic peptide,
bradykinin, angiotensin II and enkephalin were poor substrates for the enzyme.
The most powerful inhibitors of the ET-1 peptidase included thiorphan (IC50 0.28
nmol/l), phosphoramidon (IC50 0.55 nmol/l), phenanthroline (IC50 11.5
micromol/l), cyclosporin (IC50 400 micromol/l), phosphate (IC50 1.2 mmol/l),
citrate (IC50 0.6 mmol/l) and aniline naphthalene sulphonic acid (IC50 0.25
mmol/l). Our data suggest that three ET-1 degrading peptidases with optimal
activity at pH 4.5, 5.5 and 7.0, respectively, are excreted into the urine. The
enzyme with a pH optimum 4.5 is of lysosomal origin whereas the two other enzymes
correspond by their pH optima to the renal ET-1 peptidase and neutral
endopeptidase. We have found statistically significant increases (P < 0.001) in
the activity of both lysosomal and ET-1 peptidase in the urine in patients with
hypertension and in children with chronic renal failure compared with healthy
subjects or children with stable renal allograft CONCLUSIONS: Human kidney
contains an acidic, highly specific endothelin-1 inactivating
metalloendopeptidase that may have a key role in the regulation of concentrations
of renal and circulating endothelins. The enzyme is excreted into the urine where
its activity seems to be increased in patients with hypertension and chronic
renal failure; it may potentially serve as an indirect index of the renal
endothelin system.
PMID- 10779101
TI - Ambulatory blood pressure 16-26 years after the first urinary tract infection in
childhood.
AB - OBJECTIVE: To evaluate blood pressure in a population-based cohort with
urographic renal scarring after childhood urinary tract infection. DESIGN: Follow
up investigation 16-26 years after the first recognized urinary tract infection.
SETTING: University out-patient clinic for children with urinary infections
serving the local area. PATIENTS: From the original cohort of 1221 consecutive
children with first urinary tract infection diagnosed during 1970-1979, 57 of 68
with non-obstructive renal scarring participated as well as 51 matched subjects
without scarring. MAIN OUTCOME MEASURE: 24 h ambulatory blood pressure. RESULTS:
Acceptable blood pressure monitorings were obtained from 53 individuals with and
47 without scarring. There were no significant differences between the two groups
even when only patients with the most extensive scarring (individual kidney
clearance < 30 ml/min per 1.73 m2) or patients with bilateral scarring were
compared with the non-scarring group. Mean systolic or diastolic blood pressure
above +2 SD were found in 5/53 (9%) and 3/47 (6%) in the scarring and non
scarring group, respectively. Plasma renin activity, angiotensin II and
aldosterone concentrations were not significantly different, but atrial
natriuretic protein was significantly higher in the scarring group (P = 0.004).
CONCLUSION: This study demonstrates a low risk of hypertension two decades after
childhood urinary tract infection. It should be stressed that the patients with
renal scarring were under close supervision throughout childhood. Those with
scarring had higher concentrations of atrial natriuretic protein which might
indicate a counter-regulation mechanism.
PMID- 10779102
TI - Multimicroelectrode stimulation within the cat L6 spinal cord: influences of
electrode combinations and stimulus interleave time on knee joint extension
torque.
AB - During multimicroelectrode stimulation within the cat L6 spinal cord, the number
of electrodes activated, their separation distance, and the stimulus interleave
time all influenced isometric knee joint extension torque. The torque evoked by
stimulation with a three electrode combination could be enhanced or suppressed
when compared with that evoked by single or paired electrode stimulation. A
similar difference was noted when comparing two electrode combination versus
single electrode stimulation. Relative fatigue was not improved significantly by
interleaving the stimuli from two or three microelectrodes. Compared with the
extension torque response evoked by noninterleaved stimulation, torque evoked by
interleaved stimulation with the two microelectrode combination was decreased
when the electrode distance was 2.0 mm or less and increased when the electrode
distance was 3.0 mm. Designing an optimal stimulation strategy for
multimicroelectrode spinal cord stimulation will be challenging and complex if a
suppression effect among these electrodes is to be avoided. To reduce muscle
fatigue, an asynchronous, interleaved strategy of stimulation may be required.
PMID- 10779103
TI - Selective activation of muscle groups in the feline hindlimb through electrical
microstimulation of the ventral lumbo-sacral spinal cord.
AB - Selective activation of muscle groups in the feline hindlimb by electrical
stimulation of the ventral lumbo-sacral spinal cord was investigated. Spinal cord
segments L5 to S1 were mapped using a penetrating tungsten needle electrode.
Locations that produced isolated contraction of quadriceps, tibialis anterior or
triceps surae/plantaris muscles when stimulated with a current of 40 microA or
less, and in which spread of activity to other muscles was not detected after
increasing the stimulus to at least twice the threshold level, were defined as
belonging to the target muscle's "activation pool." The quadriceps activation
pool was found to extend from the beginning of L5 to the middle of L6. The
tibialis anterior activation pool extended from the beginning of L6 to the middle
of L7, and the triceps surae/plantaris activation pool extended from the caudal
end of L6 to the beginning of S1. The three activation pools were located in
Rexed motor lamina IX and their spatial organization was found to correspond well
with that of the anatomically defined motor pools innervating the same muscles.
The spatial and functional segregation of motor pools manifested at the spinal
cord level can have direct applications in the areas of functional electrical
stimulation and motor control.
PMID- 10779104
TI - Muscle recruitment through electrical stimulation of the lumbo-sacral spinal
cord.
AB - The goal of this study was to determine the feasibility of producing graded
muscle contraction in individual muscles or muscle groups by electrically
stimulating motor neurons in the lumbo-sacral spinal cord. Recruitment curves
were obtained for quadriceps, tibialis anterior and triceps surae/plantaris by
stimulating their activation pools in the ventral horn of the feline spinal cord.
Mean twitch times-to-peak for quadriceps, tibialis anterior and triceps
surae/plantaris were 33.0, 41.0, and 36.0 ms, respectively. Twitch duration as a
function of stimulus strength demonstrated a mixed motor unit recruitment order,
distinctively different from the inverse recruitment order exhibited by
conventional methods of electrical stimulation of peripheral nerve. The
recruitment curve slopes (expressed as a percentage of maximum force per
nanocurrent of delivered charge) were shallow: 7.9 for quadriceps, 2.6 for
tibialis anterior and 8.5 for triceps surae/plantaris. These results show that
graded control of force in individual muscles or muscle groups can be obtained
through spinal cord stimulation, and suggest that spinal cord stimulation could
be used for functional neuromuscular stimulation applications.
PMID- 10779105
TI - Functional electrical stimulation of abdominal muscles to augment tidal volume in
spinal cord injury.
AB - Functional electrical stimulation (FES) of abdominal muscles as a method of
enhancing ventilation was explored in six neurologically intact subjects and five
subjects with spinal cord injury (SCI) who had levels of injury between C4 and
C7. Pulmonary ventilation was augmented in both groups predominantly due to an
increase in tidal volume. The average increase in tidal volume during FES for the
neurologically intact group was 350 ml, while in the SCI group it was 220 ml. The
FES caused active volume decreases in both the lower thorax and upper abdomen,
which together appear to be the mechanism behind the increases seen in tidal
volume. Therefore, the proposed method might be useful in future clinical
practice. The results indicate that FES of abdominal muscles should be more
thoroughly explored as a potential technique of ventilatory support in SCI. The
results also point to the necessity for further studies of maintaining the
condition of the chest wall in the pulmonary rehabilitation of individuals with
tetraplegia.
PMID- 10779106
TI - Measurement of external pressures generated by nerve cuff electrodes.
AB - When external pressures are applied to a peripheral nerve, tissue damage can
occur via compression and blood flow occlusion, resulting in degeneration and
demyelination of axons. Although many types of nerve electrodes have been
designed to avoid or minimize this pressure during stimulation of the nerve or
recording of its activity, the measurement of the pressure exerted by these cuffs
has not been reported. Currently, only theoretical models are used to predict
nerve cuff electrode pressures. We have developed a nerve cuff electrode pressure
sensor to measure external pressures exerted by peripheral nerve cuff electrodes.
The sensor has a high sensitivity, linear response with little hysteresis and
reproducible output. Pressure measurements have been obtained for split-ring and
spiral cuff electrodes. The measurements obtained are in agreement with
theoretical predictions. Moreover, they indicate that the pressures exerted by
cuffs currently used for stimulation generate only a small amount of pressure,
which is below the pressure required to occlude blood flow in nerves. The results
also suggest that this new sensor can provide reliable measurement of external
pressures exerted by nerve electrodes and would be an important tool for
comparing various nerve cuff electrode designs.
PMID- 10779107
TI - Adaptive neural network control of cyclic movements using functional
neuromuscular stimulation.
AB - In this study, we evaluated the performance of an adaptive feedforward controller
and its ability to automatically develop and customize stimulation patterns for
use in functional neuromuscular stimulation (FNS) systems. Results from previous
experiments using the pattern generator/pattern shaper (PG/PS) controller to
generate isometric contractions demonstrated its ability to adjust stimulation
patterns to account for recruitment nonlinearities and muscle dynamics. In this
study, the PG/PS controller was tested under isotonic conditions. This evaluation
required the PG/PS controller to account for muscle length-tension and force
velocity properties as well as limb dynamics. The performance of the adaptive
controller was also compared with that of a proportional-derivative (PD) feedback
controller. The PG/PS controller is composed of a neural network system that
adaptively filters a periodic signal to produce a muscle stimulation pattern for
generating cyclic movements. We used computer-simulated models to determine
controller parameters for the PG/PS and PD controller that perform well across a
variety of musculoskeletal systems. The controllers were then experimentally
evaluated on both legs of two subjects with spinal cord injury. Results indicated
that the PG/PS controller was able to achieve and maintain better tracking
performance than the PD controller. This study indicates that the PG/PS control
system may provide an effective mechanism for automatically customizing
stimulation patterns for individuals using FNS systems.
PMID- 10779108
TI - Tremor suppression through impedance control.
AB - This paper presents a method for designing tremor suppression systems that
achieve a specified reduction in pathological tremor power through controlling
the impedance of the human-machine interface. Position, rate, and acceleration
feedback are examined and two techniques for the selection of feedback
coefficients are discussed. Both techniques seek a desired closed-loop human
machine frequency response and require the development of open-loop human-machine
models through system identification. The design techniques were used to develop
a tremor suppression system that was subsequently evaluated using human subjects.
It is concluded that nonadaptive tremor suppression systems that utilize
impedance control to achieve a specified reduction in tremor power can be
successfully designed when accurate open-loop human-machine models are available.
PMID- 10779109
TI - Analysis of arm trajectories of everyday tasks for the development of an upper
limb orthosis.
AB - Spatiotemporal arm and body movements of able-bodied subjects performing nine
everyday tasks were recorded for the purpose of guiding the development of an
upper-limb orthosis. To provide a user the opportunity to carry out these tasks
with natural movements, the orthosis should allow replication of the measured
trajectories. We outline the orthosis architecture, which supports the user's
upper arm and forearm, and analyze the movement data to obtain orthosis design
specifications. Trajectories were obtained using six-degree-of-freedom magnetic
position sensors affixed to the wrist, elbow, shoulder, trunk and head. Elbow
trajectory data were decomposed into ranges along the principle Cartesian axes to
provide a generally useful envelope measure. The smallest Cartesian parallel
piped that contained the elbow trajectories for most tasks was approximately 30
cm front/back, 15 cm side/side, and 17 cm up/down. A rough lower bound estimate
obtained by asking subjects to repeat the tasks while minimizing elbow movement
substantially reduced movement in the up/down and side/side dimensions. Elbow
angles were generally in the range 50 degrees-150 degrees, and the angle of the
forearm with respect to vertical was 10 degrees-110 degrees. Raw trajectory data
may be downloaded from www://asel.udel.edu/robotics/orthosis/range.h tml.
PMID- 10779110
TI - Feedback error learning neural network for trans-femoral prosthesis.
AB - Feedback-error learning (FEL) neural network was developed for control of a
powered trans-femoral prosthesis. Nonlinearities and time-variations of the
dynamics of the plant, in addition to redundancy and dynamic uncertainty during
the double support phase of walking, makes conventional control methods very
difficult to use. Rule-based control, which uses a knowledge base determined by
machine learning and finite automata method is limited since it does not respond
well to perturbations and environmental changes. FEL can be regarded as a hybrid
control, because it combines nonparametric identification with parametric
modeling and control. This paper presents simulation of a powered trans-femoral
prosthesis controlled by a FEL neural network. Results suggest that FEL can be
used to identify inverse dynamics of an arbitrary trans-femoral prosthesis during
simple single joint movements (e.g., sinusoidal oscillations). The identified
inverse dynamics then allows the tracking of an arbitrary trajectory such as a
desired walking pattern within a multijoint structure. Simulation shows that the
identified controller responds correctly when the leg motion is exposed to a
perturbation such as a frequent change of the ground reaction force or the hip
joint torque generated by the user. FEL eliminates the need for precise, tedious,
and complex identification of model parameters.
PMID- 10779111
TI - Practical low-cost visual communication using binary images for deaf sign
language.
AB - Deaf sign language transmitted by video requires a temporal resolution of 8 to 10
frames/s for effective communication. Conventional videoconferencing
applications, when operated over low bandwidth telephone lines, provide very low
temporal resolution of pictures, of the order of less than a frame per second,
resulting in jerky movement of objects. This paper presents a practical solution
for sign language communication, offering adequate temporal resolution of images
using moving binary sketches or cartoons, implemented on standard personal
computer hardware with low-cost cameras and communicating over telephone lines.
To extract cartoon points an efficient feature extraction algorithm adaptive to
the global statistics of the image is proposed. To improve the subjective quality
of the binary images, irreversible preprocessing techniques, such as isolated
point removal and predictive filtering, are used. A simple, efficient and fast
recursive temporal prefiltering scheme, using histograms of successive frames,
reduces the additive and multiplicative noise from low-cost cameras. An efficient
three-dimensional (3-D) compression scheme codes the binary sketches. Subjective
tests performed on the system confirm that it can be used for sign language
communication over telephone lines.
PMID- 10779112
TI - A novel speech controller for radio amateurs with a vision impairment.
AB - This paper describes a portable speech controller system for persons with a
vision impairment to adjust the channel frequency of a radio set via speech
commands. The speech commands are recognized on a general-purpose digital signal
processor using a hidden Markov model (HMM), and are used to remotely control
radio channel changes.
PMID- 10779113
TI - Design and evaluation of a software prototype for participatory planning of
environmental adaptations.
AB - A software prototype to support the planning process for adapting home and work
environments for people with physical disabilities was designed and later
evaluated. The prototype exploits low-cost three-dimensional (3-D) graphics
products in the home computer market. The essential features of the prototype
are: interactive rendering with optional hardware acceleration, interactive walk
throughs, direct manipulation tools for moving objects and measuring distances,
and import of 3-D-objects from a library. A usability study was conducted,
consisting of two test sessions (three weeks apart) and a final interview. The
prototype was then tested and evaluated by representatives of future users: five
occupational therapist students, and four persons with physical disability, with
no previous experience of the prototype. Emphasis in the usability study was
placed on the prototype's efficiency and learnability. We found that it is
possible to realise a planning tool for environmental adaptations, both regarding
usability and technical efficiency. The usability evaluation confirms our
findings from previous case studies, regarding the relevance and positive
attitude towards this kind of planning tool. Although the prototype was found to
be satisfactorily efficient for the basic tasks, the paper presents several
suggestions for improvement of future prototype versions.
PMID- 10779114
TI - Controlling mouse pointer position using an infrared head-operated joystick.
AB - This paper describes the motivation for and the design considerations of a low
cost head-operated joystick. The paper briefly summarizes the requirements of
head-operated mouse pointer control for people with disabilities before
discussing a set of technological approaches that can be used to satisfy these
requirements. The paper focuses on the design of a head-operated joystick that
uses infrared light emitting diodes (LED's) and photodetectors to determine head
position, which is subsequently converted into signals that emulate a Microsoft
mouse. There are two significant findings. The first is that, while nonideal
device characteristics might appear to make the joystick difficult to use, users
naturally compensate for nonlinearities, in a transparent manner, because of
visual feedback of mouse pointer position. The second finding, from relatively
informal, independent trials, indicates that disabled users prefer a head
operated device that has the characteristics of a joystick (a relative pointing
device) to those of a mouse (an absolute pointing device).
PMID- 10779115
TI - Evaluation of an isometric and a position joystick in a target acquisition task
for individuals with cerebral palsy.
AB - Individuals with cerebral palsy (CP) with upper limb disability have difficulty
operating standard computer input devices such as, a mouse and a keyboard. The
present study evaluated the performance of unimpaired individuals and those with
CP in the use of a zero-order spring-centered position joystick and a zero-order
isometric joystick when interacting with the computer. We hypothesize that the
isometric device due to its stiff resistance would provide better control on
cursor movement than the position joystick. The subjects acquired differently
sized targets at different distances by positioning a cursor on the target.
Performance with the position joystick was superior to that of the isometric
joystick. The time to acquire the target was directly proportional to the cursor
target distance A, and indirectly proportional to the target size W. Subjects
chose to move more slowly toward the smaller and closer targets and they
increased speed for larger and more distant targets. The phase-plane diagram that
plots values of the velocity profile of the cursor over its displacement revealed
the presence of one large amplitude movement that accounts for the peak velocity
of the cursor, and several submovements. Fitts' index of difficulty, log(e)(2W/A)
was found to be a good predictor of the movement time in a cursor positioning
task for both, unimpaired individuals and those with CP.
PMID- 10779116
TI - Development of a wheelchair occupant injury risk assessment method and its
application in the investigation of wheelchair securement point influence on
frontal crash safety.
AB - To promote proper wheelchair securement in transportation, the proposed
ANSI/RESNA Standard on Wheelchairs Used as Seats in Motor Vehicles will require
that all transit wheelchairs be equipped with four securement points compatible
with strap-type tiedowns. Through computer simulations, the location of these
securement points has been found to influence wheelchair user response to a
frontal crash. This study develops and employs an injury risk assessment method
to compare the crashworthiness of various securement point configurations. The
comparative injury risk assessment method is designed to predict the risk
associated with internalized crash forces, as well as risk associated with
secondary occupant impact with the vehicle interior. Injury criteria established
by Federal Motor Vehicle Safety Standards and General Motors, along with
excursion limitations set by the Society of Automotive Engineers (SAE) J2249
Wheelchair Tiedowns and Occupant Restraint Systems (WTORS) Standard were used as
benchmarks for the risk assessment method. The simulation model subjected a
secured commercial powerbase wheelchair with a seated 50th percentile male Hybrid
III test dummy to a 20 g/30 mph crash. The occupant was restrained using pelvic
and shoulder belts, and the wheelchair was secured with four strap-type tiedowns.
Results indicated that securement points located 1.5 in to 2.5 in above the
evaluated wheelchair's center of gravity provide the most effective occupant
protection.
PMID- 10779117
TI - Biomechanical analysis of legrest support of occupied wheelchairs: comparison
between a conventional and a compensatory legrest.
AB - This study was undertaken to investigate the effects of elevating legrest on
posture and pressure distribution in a group of ten able-bodied subjects sitting
in a manual wheelchair. Two types of legrest were tested: a conventional
elevating legrest with a fixed axis of rotation, and a compensatory elevating
legrest with a moving axis of rotation. A three-dimensional (3-D) kinematics
analysis was carried out to assess body posture simultaneously with pressure
measurement data collected at the back, seat, calf and foot supports. The
compensatory legrest enables to lengthen foot support as the legrest proclines.
This compensation at the knee joint level has a beneficial effect in minimizing
pelvic and thigh motion as well as in reducing pressure distribution under seat
and foot supports. In contrast, the use of a conventional legrest modifies
significantly the subject's posture and induces a substantial increase of 40% on
pressure data under ischial tuberosities in procline position. These findings are
important for disabled and elderly people who need to elevate their lower leg
frequently.
PMID- 10779118
TI - A mechanical arthrometer to measure knee joint contracture in rats.
AB - Animal models for joint diseases are necessary for in vivo studies. Joint
contractures are characterized by lack of the normal range of motion of a joint
most often due to increased soft tissue stiffness. Biological and biochemical
data have been obtained but biomechanical data on small animals are rare. An
instrument was developed to measure rat knee angular displacement at various soft
tissue loads in normal and pathological circumstances. This article describes the
instrument and reports its reproducibility and accuracy. The reproducibility and
accuracy of this instrument was found to be acceptable thereby validating its use
for research purposes with adult rat knees.
PMID- 10779119
TI - Biomechanical evaluation of a prototype foot/ankle prosthesis.
AB - In this paper, we report on our pilot evaluation of a prototype foot/ankle
prosthesis. This prototype has been designed and fabricated with the intention of
providing decreased ankle joint stiffness during the middle portion of the stance
phase of gait, and increased (i.e., more normal) knee range of motion during
stance. Our evaluation involved fitting the existing prototype foot/ankle
prosthesis, as well as a traditional solid ankle cushioned heel (SACH) foot, to
an otherwise healthy volunteer with a below-knee (BK) amputation. We measured
this individual's lower extremity joint kinematics and kinetics during walking
using a video motion analysis system and force platform. These measurements
permitted direct comparison of prosthetic ankle joint stiffness and involved side
knee joint motion, as well as prosthetic ankle joint moment and power.
PMID- 10779120
TI - Nitric oxide as a metabolic regulator during exercise: effects of training in
health and disease.
AB - 1. Accumulating animal and human data suggest that nitric oxide (NO) is important
for both coronary and peripheral haemodynamic control and metabolic regulation
during performance of exercise. 2. While still controversial, NO of endothelial
origin is thought to potentiate exercise-induced hyperaemia, both in the
peripheral and coronary circulations. The mechanism of release may include both
acetylcholine derived from the neuromuscular junction and vascular shear stress.
3. A splice variant of neuronal nitric oxide synthase (NOS), nNOSmicro,
incorporating an extra 34 amino acids, is expressed in human skeletal muscle. In
addition to being a potential modulator of blood flow, skeletal muscle-derived NO
is an important regulator of muscle contraction and metabolism. In particular,
recent human data indicate that NO modulates muscle glucose uptake during
exercise, independently of blood flow. 4. Exercise training in healthy
individuals promotes adaptations in the various NO systems, which can increase NO
bioavailability through a variety of mechanisms, including increased NOS enzyme
expression and activity. Such adaptations likely contribute to increased exercise
capacity and protection from cardiovascular events. 5. Cardiovascular risk
factors, including hypercholesterolaemia, hypertension, diabetes and smoking, as
well as established disease, are associated with impairment of the various NO
systems. Given that NO is an important signalling mechanism during exercise, such
impairment may contribute to limitations in exercise capacity through inadequate
coronary or peripheral blood delivery and via metabolic effects. 6. Exercise
training in individuals with elevated cardiovascular risk or established disease
can increase NO bioavailability and may represent an important mechanism by which
exercise training provides benefit in the setting of secondary prevention.
PMID- 10779121
TI - Congenic rats for hypertension: how useful are they for the hunting of
hypertension genes?
AB - 1. Linkage studies have revealed quantitative trait loci (QTL) for blood pressure
in the rat genome using genetic hypertensive rat models. To identify the genes
responsible for hypertension, the construction of congenic rats is essential. 2.
To date, several congenic strains have been obtained from spontaneously
hypertensive or Dahl salt-sensitive rats. The results of these studies should be
interpreted according to whether the rats carry the whole QTL region or not. 3.
After establishing congenic strains, three strategies are possible: (i) an
orthodox positional cloning in which, using subcongenic strains, the QTL region
is cut down to smaller fragments suitable for physical mapping; (ii) a positional
candidate strategy in which candidate genes in the QTL regions are studied; or
(iii) physiological studies in which intermediate phenotypes directly associated
with the hypertension gene are explored. Several other experimental strategies
are also available using congenic strains as new animal models for hypertension.
4. To make the most of advances in DNA technology, the precise evaluation of the
phenotypic difference between congenic strains carrying different QTL or between
a congenic and parental strain is critical.
PMID- 10779123
TI - Cardiac and vascular responses in deoxycorticosterone acetate-salt hypertensive
rats.
AB - 1. Hypertension leads to ventricular hypertrophy and, eventually, to heart
failure. The present study has investigated the functional consequences of
deoxycorticosterone acetate (DOCA)-salt hypertension in rats by defining the
inotropic, chronotropic and vascular responses to noradrenaline (NA; beta1
adrenoceptor agonist), forskolin (adenylate cyclase activator) and theophylline
(phosphodiesterase inhibitor). 2. Administration of DOCA (25 mg, s.c., every 4th
day) and excess salt (1% NaCl in drinking water) to uninephrectomized rats
increased left ventricular wet weight by 35 and 71% after 4 and 8 weeks,
respectively. Addition of KCl (0.4%) or CaCl2 (1%) in the drinking water for 4
weeks attenuated blood pressure increases, but not ventricular weight increases
(46 and 28%, respectively). 3. Positive inotropic responses in papillary muscles
from uninephrectomized rats to NA (-log EC50 6.73+/-0.38; n = 7), forskolin (-log
EC50 6.15+/-0.31; n = 7) and CaCl2 (-log EC50 2.40+/-0.02; n = 14) were unchanged
in hypertrophied left ventricles of DOCA and DOCA-CaCl2 rats, although maximal
responses to NA were decreased in DOCA-KCI rats (1.2+/-0.6 mN, n = 8; DOCA-salt
2.9+/-0.5 mN, n = 6); theophylline was less potent in DOCA-salt rats. Positive
chronotropic responses to NA, forskolin and theophylline in right atria and
negative inotropic responses to carbachol in papillary muscles were unchanged. 4.
Maximal vasoconstrictor responses to NA in thoracic aortic rings were reduced in
DOCA-KCI rats to 2.4+/-0.9 mN (n = 5), but were increased in DOCA-CaCl2 rats to
26.6+/-2.2 mN (n = 7; DOCA-salt 7.8+/-2.2 mN, n = 9). Vasorelaxant responses to
forskolin and theophylline were unchanged. 5. These results show that cardiac
responses are only minimally affected during the development of DOCA-salt
hypertension-induced hypertrophy, despite the reported decreases in adenylate
cyclase activity, in these rats. This is in contrast with the decreased responses
reported in other rat models of cardiac hypertrophy and in the failing human
heart. Thus, hypertrophy in hearts of DOCA-salt hypertensive rats does not
produce similar changes to the failing human heart.
PMID- 10779122
TI - Pretreatment with ramiprilat induces cardioprotection against free radical injury
in guinea-pig isolated heart: involvement of bradykinin, protein kinase C and
prostaglandins.
AB - 1. Pretreatment with ramiprilat, an angiotensin-converting enzyme (ACE)
inhibitor, induced cardioprotection and its possible mechanism of action was
investigated in guinea-pig Langendorff perfused heart. 2. Superoxide anion (*O2
), produced by hypoxanthine and xanthine oxidase, and the 1,1-diphenyl-2-picryl
hydrazyl (DPPH) free radical were used for triggering free radical injury in
cardiac tissue. 3. 1,1-Diphenyl-2-picryl-hydrazyl and *O2- significantly reduced
left ventricular developed pressure (LVDP), +/-dP/dt(max), heart rate and
coronary flow. Left ventricular end-diastolic pressure (LVEDP) was elevated and
lactate dehydrogenase (LDH) leakage and the formation of thiobarbituric acid
reactive substances (TBARS) formation were significantly increased. 4.
Pretreatment with ramiprilat induced cardioprotection against DPPH and *O2- free
radical injury. Cardiac functions (LVDP, LVEDP and +/-dP/dt(max)) were
significantly improved. Both LDH and TBARS were reduced. 5. HOE 140 (a selective
bradykinin B2 receptor antagonist), calphostin C (a protein kinase C (PKC)
inhibitor) and indomethacin (a cyclo-oxygenase inhibitor) all abolished the
cardiac protective effect of ramiprilat. However, N(G)-nitro-L-arginine methyl
ester, a nitric oxide synthase inhibitor, had no effect. 6. In conclusion,
ramiprilat pretreatment induces cardioprotection against either DPPH or *O2- free
radical injury. The protective effect depends on activation of B2 receptors and
PKC. Prostaglandin synthesis is also involved.
PMID- 10779125
TI - Ginkgo biloba extract attenuates the development of hypertension in
deoxycorticosterone acetate-salt hypertensive rats.
AB - 1. We examined the effects of Ginkgo biloba extract (GBE) on the development of
hypertension, platelet activation and renal dysfunction in deoxycorticosterone
acetate (DOCA)-salt hypertensive rats. Both DOCA-salt hypertensive rats and
normotensive rats were fed a 2% GBE diet for 20 days. Blood pressure (BP) was
measured by two methods, namely by the tail-cuff and telemetry methods. 2.
Development of hypertension was attenuated in rats fed a 2% GBE diet. In
addition, an increase in heart weight, an indicator of sustained high BP, was
inhibited significantly by feeding of the GBE diet. 3. Decreases in 5
hydroxytryptamine content in platelets, a marker of platelet activation in vivo
associated with hypertension, were also prevented by feeding of the GBE diet.
Ginkgo biloba extract itself did not inhibit ADP- and collagen-induced platelet
aggregation examined in vitro. Feeding of the GBE diet tended to inhibit
increases in plasma urea nitrogen due to hypertension. 4. The telemetry study
demonstrated that BP and heart rate (HR) showed a clear circadian rhythm and the
antihypertensive effect of GBE was prominent in the daytime, a resting period for
rats. This anti-hypertensive effect of GBE was not detected in normotensive rats.
In contrast, the inhibitory effect of GBE on HR was independent of time and was
observed in both normotensive and hypertensive rats. 5. These results indicate
that GBE has an anti-hypertensive and bradycardiac action, which are time
dependent and independent, respectively. Thus, it appears that the
chronopharmacological action of GBE may be ascribed not to pharmacokinetic
factors, but rather to a circadian susceptibility rhythm to GBE in DOCA-salt
hypertensive rats.
PMID- 10779126
TI - Tissue distribution of alpha-tocopherol in nephrotic rats.
AB - 1. Reactive oxygen species are involved in the pathogenesis of puromycin
aminonucleoside (PAN) nephrosis and alpha-tocopherol is one of the major anti
oxidants in the body. 2. In the present study, we measured the levels of alpha
tocopherol by high-performance liquid chromatography in the plasma and in nine
tissues of control and nephrotic rats obtained 10 days after either 0.9% saline
solution or PAN injection, respectively. 3. In nephrotic rats, alpha-tocopherol
levels increased four-fold in plasma; however, the molar ratio of alpha
tocopherol/ cholesterol remained unchanged, suggesting that the increase in alpha
tocopherol content was attributable to an increase in plasma lipid concentration.
4. In nephrotic rats, the alpha-tocopherol/cholesterol ratio increased 1.33-fold
in adrenal glands and 1.34-fold in the testis, but remained unchanged in heart,
spleen, liver, kidney lung, brain and muscle. 5. These data suggest that, in PAN
nephrotic rats, there are alterations in the distribution of alpha-tocopherol and
there is no deficiency of alpha-tocopherol in plasma or tissues.
PMID- 10779127
TI - KRN2391: dual action on rat pulmonary artery and no loss of potency in pulmonary
hypertension.
AB - 1. The pulmonary vasorelaxant properties of KRN2391 (N-cyano-N'-(2-nitroxyethyl)
3-pyridinecarboximidamide) were examined in isolated ring preparations of main
(MPA) and intralobar (IPA) pulmonary artery from control and pulmonary
hypertensive rats (exposure to hypoxia, 10% oxygen, for 1 week). 2. On both MPA
and IPA, pulmonary vasorelaxant responses were inhibited by methylene blue (10
micromol/L) or glibenclamide (1 or 10 micromol/L). Thus, KRN2391 has the
properties of both a nitric oxide (NO) donor and a K(ATP) channel opener on rat
pulmonary arteries. 3. KRN2391 was more potent and gave a greater maximum
relaxation on MPA (-log EC(50) 6.47; maximum 92% reversal of induced contraction)
than on IPA (-log EC(50) 6.09; maximum 58% reversal of induced contraction).
Comparable differences between MPA and IPA were seen for SIN-1 (NO donor) and
levcromakalim (K(ATP) channel opener). 4. KRN2391 was equipotent in MPA from
control and pulmonary hypertensive rats but, when glibenclamide (10 micromol/L)
was present, KRN2391 was six-fold less potent in preparations from pulmonary
hypertensive than control rats. An eight-fold reduction in potency was seen for
SIN-1 (no glibenclamide) in arteries from pulmonary hypertensive rats, confirming
previous findings with other NO donors. 5. It is concluded that the dual
mechanism of action of KRN2391 accounts for the finding that this drug is equally
potent in pulmonary arteries from pulmonary hypertensive and control rats. In the
context of pulmonary hypertension, this property of the drug could give it an
advantage over drugs that act solely as NO donors because these decline in
potency, at least in animal models of this disease.
PMID- 10779124
TI - KRH-594, a new angiotensin AT1 receptor antagonist, ameliorates nephropathy and
hyperlipidaemia in diabetic spontaneously hypertensive rats.
AB - 1. We examined whether KRH-594, a new angiotensin AT1 receptor antagonist,
ameliorates the progression of diabetic nephropathy and hyperlipidaemia in
streptozotocin (STZ)-induced diabetic unilateral nephrectomized spontaneously
hypertensive rats (DM-1K-SHR) or not. 2. The oral administration of KRH-594 (3
and 10 mg/kg per day) and candesartan cilexetil (1 mg/kg per day) for 16 weeks
significantly reduced systolic blood pressure, urinary albumin and urinary total
protein in DM-1K-SHR. 3. In a histological study, KRH-594 (3 and 10mg/kg per day)
and candesartan cilexetil (0.3 and 1 mg/kg per day) dose-dependently improved
glomerulosclerosis and the hyalin cast of tubules in DM-1K-SHR kidneys. Both KRH
594 (10 mg/kg per day) and candesartan cilexetil (0.3 and 1 mg/kg per day) dose
dependently inhibited cardiac hypertrophy. 4. KRH-594 (3 and 10 mg/kg per day),
but not candesartan cilexetil, dose-dependently reduced the levels of
triglyceride, total cholesterol and phospholipids in DM-1K-SHR. 5. These results
suggest that KRH-594 improves diabetic complications, such as nephropathy and
hyperlipidaemia, with hypertension.
PMID- 10779128
TI - Treatment of joint pain in Crohn's patients with budesonide controlled ileal
release.
AB - 1. Joint pain is a frequent manifestation of Crohn's disease. Budesonide
controlled ileal release (CIR) is a predominantly topically acting
glucocorticosteroid, which is effective in treating active ileal or ileocaecal
Crohn's disease. 2. Therefore, it was of interest to study the effect of this
predominantly topically acting therapy on the treatment of an extraintestinal
symptom of Crohn's disease by analysing data collected from budesonide CIR
(Entocort; Astra Draco AB, Lund, Sweden) trials. 3. Three large studies of
budesonide CIR treatment in active Crohn's disease provided a reliable source of
clinical data. Of the 611 patients treated in the prospective double-blind
controlled trials, 291 had joint pain (arthritis/arthralgia) at entry, which was
recorded as part of the Crohn's Disease Activity Index. Statistical analysis was
based on all patients treated, provided that the patient had joint pain at the
start of treatment. 4. Daily oral budesonide CIR (9mg) resulted in clinical
remission of joint pain in 74% (95% confidence intervals (CI) 67-82%) of
patients. This outcome was nearly twice as good as placebo (41%; 95% CI 34-57%)
and as good as the outcome effected by daily oral prednisolone (40mg; 72%; 95% CI
60-84%). The favourable response to budesonide CIR (9 mg) did not correlate with
glucocorticosteroid-associated side effects or with adrenal suppression, which
were half those in the prednisolone (40 mg/day) group. 5. The favourable outcome
may relate to restitution of normal intestinal immune function.
PMID- 10779129
TI - Effect of experimental diabetes on GABA-mediated inhibition of neurally induced
contractions in rat isolated trachea.
AB - 1. In the present study, we investigated the effect of GABA and selective GABA
agonists and antagonists on neurally induced tracheal contractions in
streptozotocin (STZ) diabetic rats. 2. Contractile responses to electrical field
stimulation (EFS) in rat tracheal rings were completely abolished by atropine and
tetrodotoxin, but were unaffected by the ganglion blocker hexamethonium,
indicating that they were mediated via neuronal release of acetylcholine (ACh).
3. Contractions induced by EFS, but not by exogenous ACh, were inhibited by GABA
and the selective GABA(B) receptor agonist baclofen, but not by the selective
GABA(A) receptor agonist 3-aminopropane sulphonic acid. The inhibitory effects of
GABA or baclofen were not affected by the GABA(A) antagonist bicuculline, but
were significantly reversed by the GABA(B) antagonist phaclofen. 4. The
inhibitory effects of both GABA and baclofen were found to be significantly
greater in trachea from control rats compared with tissues from diabetic rats. 5.
Non-adrenergic, non-cholinergic relaxation responses elicited by EFS in
precontracted tracheal rings from diabetic and control rats were similar in
magnitude and were unaffected by GABA or GABA analogues. 6. These results suggest
that GABA decreases the response to EFS by directly inhibiting the evoked release
of ACh through GABA(B) receptors in rat trachea and that STZ-induced diabetes
causes an impairment in the inhibitory effect of GABA on neurally induced
contractions in this tissue.
PMID- 10779131
TI - A short history of nitroglycerine and nitric oxide in pharmacology and
physiology.
AB - 1. Nitroglycerine (NG) was discovered in 1847 by Ascanio Sobrero in Turin,
following work with Theophile-Jules Pelouze. Sobrero first noted the 'violent
headache' produced by minute quantities of NG on the tongue. 2. Constantin
Hering, in 1849, tested NG in healthy volunteers, observing that headache was
caused with 'such precision'. Hering pursued NG ('glonoine') as a homeopathic
remedy for headache, believing that its use fell within the doctrine of 'like
cures like'. 3. Alfred Nobel joined Pelouze in 1851 and recognized the potential
of NG. He began manufacturing NG in Sweden, overcoming handling problems with his
patent detonator. Nobel suffered acutely from angina and was later to refuse NG
as a treatment. 4. During the mid-19th century, scientists in Britain took an
interest in the newly discovered amyl nitrite, recognized as a powerful
vasodilator. Lauder Brunton, the father of modern pharmacology, used the compound
to relieve angina in 1867, noting the pharmacological resistance to repeated
doses. 5. William Murrell first used NG for angina in 1876, although NG entered
the British Pharmacopoeia as a remedy for hypertension. William Martindale, the
pharmaceutical chemist, prepared '...a more stable and portable preparation':
1/100th of a grain in chocolate. 6. In the early 20th century, scientists worked
on in vitro actions of nitrate-containing compounds although little progress was
made towards understanding the cellular mode of action. 7. The NG industry
flourished from 1900, exposing workers to high levels of organic nitrites; the
phenomena of nitrate tolerance was recognized by the onset of 'Monday disease'
and of nitrate-withdrawal/overcompensation by 'Sunday Heart Attacks'. 8. Ferid
Murad discovered the release of nitric oxide (NO) from NG and its action on
vascular smooth muscle (in 1977). Robert Furchgott and John Zawadski recognized
the importance of the endothelium in acetylcholine-induced vasorelaxation (in
1980) and Louis Ignarro and Salvador Moncada identified endothelial-derived
relaxing factor (EDRF) as NO (in 1987). 9. Glycerol trinitrate remains the
treatment of choice for relieving angina; other organic esters and inorganic
nitrates are also used, but the rapid action of NG and its established efficacy
make it the mainstay of angina pectoris relief.
PMID- 10779130
TI - Importance of histamine, glutathione and oxyradicals in modulating gastric
haemorrhagic ulcer in septic rats.
AB - 1. The ulcerogenesis of gastric haemorrhagic damage during sepsis is unclear. The
present study first proposes that gastric haemorrhagic ulcer is modulated by
mucosal glutathione, histamine and oxyradicals in lipopolysaccharide (LPS)
induced sepsis in rats. The protective effects of several drugs on the
ulcerogenic parameters also were evaluated. 2. Male specific pyrogen-free Wistar
rats were deprived of food for 24 h. For the induction of sepsis, intravenous LPS
(0, 1, 3 or 10 mg/kg in 1 mL sterilized normal saline) was challenged to rats 12
h after withdrawal of food. Rat stomachs were vagotomized, followed by irrigation
for 3 h with normal saline or a physiological acid solution containing 100 mmol/L
HCI and 54 mmol/L NaCl. 3. The aggravation of gastric ulcerogenic parameters,
such as gastric acid back-diffusion, luminal haemoglobin content, mucosal lipid
peroxide production, histamine concentration, as well as lowered concentrations
of defensive substances, including mucosal glutathione, were dependent on the
doses of LPS used for challenge. A high correlation was observed between mucosal
histamine release and lipid peroxide production in LPS rats. 4. The ulcerogenic
parameters obtained in LPS (3 mg/kg, i.v.) rats were potently attenuated by
diamine oxidase, ketotifen and zinc sulphate. 5. Several oxyradical scavengers,
including glutathione, dimethylsulphoxide and allopurinol, also were effective in
inhibiting haemorrhagic ulcer. 6. In conclusion, gastric mucosal histamine
release and oxyradical generation play pivotal roles in the formation of
haemorrhagic ulcers in septic rats.
PMID- 10779133
TI - Teaching about thyroid in our schools.
PMID- 10779132
TI - Glycopyrrolate treatment of drooling in an adult male patient with cerebral
palsy.
AB - 1. The aim of the study was to assess the effect of glycopyrrolate on drooling in
an adult male patient with cerebral palsy. 2. After a thorough medical
examination and consent in writing by the responsible guardian, a baseline sum
score for frequency and seriousness of drooling was established over a 2 week
period in addition to data on shifts of handkerchiefs, urination, defecation and
observation of behaviour. Glycopyrrolate (1 mg) tablets were then administered,
starting with one tablet daily the third week and increasing the daily dose by
one tablet per week until a maximum of four tablets during week six and 4 days of
week seven when the daily dose was reduced to two tablets for 3 days. For the
four weeks 8-11 three tablets were given daily. In week 12 the dose was reduced
to two tablets and for the weeks 13-15 no tablets of glycopyrrolate were given.
3. For as long as the patient received three to four tablets of glycopyrrolate
daily, drooling was markedly reduced and handkerchiefs were not necessary on some
days. After the tablets were withdrawn drooling increased to approximately the
same level as it was before treatment. No adverse medical, psychological, or
social effects were observed. 4. For shorter periods, glycopyrrolate can be given
in controlled doses provided that an adequate medical assessment has been
undertaken.
PMID- 10779134
TI - The rat hepatic lectin-1 subunit of the asialoglycoprotein receptor is
upregulated by thyrotropin and downregulated by neoplastic transformation of
thyroid cells.
AB - We have recently shown that the rat hepatic lectin (RHL)-1 subunit of the
asialoglycoprotein receptor (ASGPr) is expressed in the PC C13 differentiated
thyroid cell line. To investigate in vivo the expression of RHL-1 and the ability
of thyrotropin (TSH) to modulate its expression, reverse-transcriptase polymerase
chain reaction (RT-PCR) and Western blot assays have been performed on thyroid
extracts from rats treated with thyroxine (T4) or propylthiouracil (PTU), each of
which modulates TSH levels. It is shown that RHL-1 expression is down-regulated
by T4 (which decreases serum TSH) and upregulated by PTU (which increases serum
TSH), at both mRNA and protein levels. The sensitivity of RHL-1 to neoplastic
transformation of thyroid cells has been investigated. The RHL-1 expression
pattern has been studied in PC C13 thyroid cells transformed by several oncogenes
that induce different degrees of malignancy and dedifferentiation. RT-PCR and
Western blot assays show that RHL-1 expression progressively decreases as PC C13
cells acquire a more transformed phenotype. Expression of glyceraldehyde-3
phosphate dehydrogenase (GAPDH) mRNA, a housekeeping gene used as internal
control to normalize RHL-1 mRNA content, exhibits no variations in the different
PC C13 cell lines used. In addition, we show that both native and asialo
thyroglobulin (Tg) bind RHL-1 in vitro, and native Tg binds RHL-1 on the surface
of PC C13 cells. After thyroid cells transformation, the surface expression of
RHL-1 is inhibited in a measure that correlates with the mRNA and protein levels.
Therefore, the RHL-1 inhibition at the mRNA, protein and plasma membrane
expression follows a gradient that parallels the progressive acquisition of the
fully transformed phenotype in the PC C13 system. The results reported in the
present article, together with our previous data, suggest that RHL-1 expression
could be regulated, at least in part, by the same transcription factors involved
in the expression of the other molecules characteristic of the thyroid
differentiated state.
PMID- 10779135
TI - Expressions of human sodium iodide symporter mRNA in primary and metastatic
papillary thyroid carcinomas.
AB - The sodium iodide symporter (NIS) is a plasma membrane protein that is
responsible for iodide transport into thyroid cells. To understand the regulation
and expression of human NIS (hNIS) in papillary thyroid carcinomas, we evaluated
the expression levels of hNIS mRNA in primary and lymph node metastatic papillary
carcinoma tissues. The correlation of mRNA levels between hNIS and thyroid
specific genes, thyrotropin (TSH) receptor, and thyroglobulin (Tg), were also
investigated. Twenty-three cases of papillary carcinoma and 7 pairs of primary
and lymph node metastastic tissues were included in this study. We measured the
expression levels of hNIS, TSH receptor, and Tg mRNAs by semiquantitative reverse
transcription-polymerase chain reaction (RT-PCR) and RNase protection assay
(RPA). The levels of hNIS mRNA in lymph node metastatic tissues were evaluated by
RT-PCR. By semiquantitative RT-PCR, 87% of papillary carcinoma (20/23) expressed
hNIS mRNA, but the degrees of expression were variable and were lower than those
of normal thyroid tissues. The decreased expression of hNIS mRNA in papillary
carcinoma compared to normal thyroid tissue was also noticed by RPA. All 23
papillary carcinomas in this study showed the expression of TSH receptor and Tg
mRNAs. The levels of TSH receptor mRNA were again lower in papillary thyroid
carcinomas than in normal controls. The level of hNIS mRNA was correlated with
the levels of TSH receptor (r = 0.449, p < 0.05), but not with Tg mRNA. In
addition, significant correlation of mRNA level was observed between TSH receptor
and Tg (r = 0.706, p < 0.01). Two of six lymph node metastatic tissues did not
show hNIS mRNA even with significant hNIS expressions in papillary carcinoma
tissues in thyroid. The levels of hNIS expression of the remaining four lymph
node metastatic tissues were lower than those of corresponding primary tissues.
Interestingly, one case showed no hNIS expression in primary tissue, but
significant hNIS expression in lymph node metastatic tissue. No correlation was
found in hNIS mRNA expression between primary and lymph node metastatic tissues.
Our results suggest that the measurements of hNIS mRNA level in primary tissues
may not predict the therapeutic response to radioactive iodine.
PMID- 10779136
TI - Thyrotropin regulation of cyclic adenosine monophosphate production in human
coronary artery smooth muscle cells.
AB - Thyroid disease has been associated with the occurrence of pathophysiologic
changes in the vasculature that may result in part from altered serum thyroid
hormone and serum lipid levels. Thyrotropin (TSH) levels are also altered in
thyroid disease, but a direct effect of TSH on vascular smooth muscle has not
previously been considered. In the present study, human coronary artery smooth
muscle cells (CASMC) were induced into two morphologically distinct forms by
culturing in either (1) growth factor supplemented, 0.5% serum medium (SmGM-3) or
(2) basal medium (SmBM) plus 10% fetal bovine serum (FBS). Intracellular cyclic
adenosine monophosphate (cAMP) accumulation was determined by radioimmunoassay
after exposure to increasing doses of bovine TSH. Cells grown in SmBM/10% FBS for
3 days exhibited a dose-dependent increase in intracellular cAMP that reached a
level 10 times higher than baseline at the highest dose examined (100 mIU/mL). In
contrast, cells grown in SmGM-3 medium exhibited no change in intracellular cAMP
on exposure to increasing TSII. Low serum (0.5% FBS) reduced the ability of TSH
to stimulate cAMP above the control value in CASMC. Pretreatment of CASMC with
either transforming growth factor-beta1 (TGF-beta1) or tumor necrosis factor
alpha (TNF-alpha) lowered basal levels of cAMP production, but did not inhibit
the ability of TSH to stimulate cAMP production. Human, but not rat aortic smooth
muscle cells in culture also responded to TSH with a significant increase in
cAMP. The results of this study suggest that TSH may exert direct effects on
vascular smooth muscle mediated by adenylate cyclase activation that could
conceivably affect the progression of vascular disease associated with thyroid
dysfunction.
PMID- 10779137
TI - Maturation of human hypothalamic-pituitary-thyroid function and control.
AB - Measurements of serum thyrotropin (TSH) and free thyroxine (T4) concentrations
were conducted in infants, children, and adults to assess maturation of the
hypothalamic-pituitary-thyroid (HPT) feedback control axis. Serum free T4 and TSH
concentration data were collated for cord blood of the midgestation fetus, for
premature and term infants, and for peripheral blood from newborn infants,
children, and adults. Mean values were plotted on a nomogram developed to
characterize the reference ranges of the normal axis quantitatively based on data
from 522 healthy subjects, 2 weeks to 54 years of age; 83 untreated hypothyroid
patients; and 116 untreated hyperthyroid patients. Samples for 75 patients with
thyroid hormone resistance were also plotted. The characterized pattern of HPT
maturation included a progressive decrease in the TSH/free T4 ratio with age,
from 15 in the midterm fetus, to 4.7 in term infants, and 0.97 in adults.
Maturation plotted on the nomogram was complex, suggesting increasing
hypothalamic-pituitary T4 resistance during fetal development, probably secondary
to increasing thyrotropin-releasing hormone (TRH) secretion, the marked, cold
stimulated TRH-TSH surge at birth with reequilibration by 2-20 weeks, and a final
maturation phase characterized by a decreasing serum TSH with minimal change in
free T4 concentration during childhood and adolescence. The postnatal maturative
phase during childhood and adolescence correlates with the progressive decrease
in thyroxine secretion rate (on a microg/kg per day basis) and metabolic rate and
probably reflects decreasing TRH secretion.
PMID- 10779138
TI - The use of fine-needle aspiration biopsy under ultrasound guidance to assess the
risk of malignancy in patients with a multinodular goiter.
AB - PURPOSE: Fine-needle aspiration biopsy (FNAB) is a commonly performed procedure
used in the evaluation of solitary thyroid nodules, in which the risk of
malignancy is approximately 5% in most patients. Recently, the use of ultrasound
(US) guidance in FNAB has been shown to enhance the diagnostic efficacy of this
procedure. However, the risk of malignancy in thyroid nodules occurring within a
multinodular goiter (MNG) has not been completely clarified, nor has the optimal
means of investigating such nodules using FNAB. SUBJECTS AND METHODS: We
performed a retrospective study of all patients seen over a 4-year period with a
MNG that had one or more nodules who underwent FNAB under US guidance. The
results from the history and physical examination, thyroid function and antibody
tests, radionuclide studies, thyroid sonogram, cytology of aspirated nodules, and
surgical pathology were recorded and analyzed. RESULTS: A total of 93 nodules
were aspirated in 61 patients with MNG. Adequate material was obtained in 96% of
aspirates on the first attempt. Sixty-seven aspirates in 44 patients yielded
benign cytology and 22 aspirates in 15 patients yielded suspicious cytology. All
patients with suspicious cytology underwent thyroid surgery. Thyroid cancer was
found in 5 of these nodules, including 4 cases of papillary cancer and 1 case of
Hurthle cell cancer, and 1 additional patient had occult papillary cancer
discovered. The overall malignancy rate in thyroid nodules among the patients
with MNG was approximately 5%. CONCLUSIONS: FNAB under US guidance is a useful
diagnostic modality in the evaluation of thyroid nodules in selected patients
with MNG. Because the risk of thyroid malignancy in these nodules is comparable
to that which exists in solitary thyroid nodules, the possibility of thyroid
malignancy should be considered in all patients with MNG.
PMID- 10779139
TI - Neuropsychological follow-up in early-treated congenital hypothyroidism: a
problem-oriented approach.
AB - Screening programs for congenital hypothyroidism (CH) dramatically improved the
neuropsychological prognosis in affected children. However, mild impairments in
cognitive performances, poorer motor skills, defective language abilities, and
learning problems have been reported in some studies of early-treated CH
children. The occurrence of these defects makes neuropsychological follow-up
mandatory. The aim of the present study was to identify those neuropsychological
functions that are more frequently affected in early-treated CH children and that
might require prompt rehabilitation treatment to prevent permanent defects. The
study group involved 24 CH children. Levothyroxine (LT4) treatment (initial dose
8-10 microg/kg per day) was started at mean age of 28 days (range 15-45) and was
then adjusted with the goal to keep thyrotropin (TSH) and free thyroid hormone
levels in the normal range. Cognitive evaluation was performed at 3, 5, and 7
years of age and did not significantly differ from that of controls. Mean
neurological scores were lower in children 5 years of age than in controls.
Children with severe neonatal hypothyroidism (serum thyroxine [T4] < 2 microg/dL)
had significantly lower neurological scores compared to less affected CH children
and normal controls. The most affected functions were balance, extremity
coordination, fine motricity, quality of movements, associated movements, and
head movements. Language disorders were observed in half of CH children at 3 and
5 years of age, but moderately severe defects were restricted to those with
severe neonatal hypothyroidism. In conclusion, a problem-oriented, simplified
neuropsychological follow-up of early-treated children with CH should not
systematically include the frequent repetition of time-consuming and expensive
psychometric tests because individual IQ scores are in the normal range of tests
in almost all CH children and can be differentiated from those of normal controls
only on a population-statistic basis. Selected tests of motor proficiency are
indicated at 3 and 5 years of age to detect those defects in motor skills that
appear to be more specifically affected in CH children. Language performances are
at particular risk in CH children, and should be always checked at 3 and 5 years
of age. Children with even mild language disorders or delayed language
achievements should be regularly reevaluated at 6-month intervals and, if no
spontaneous improvement is observed, they should receive specific rehabilitation
treatment. No further motor and language evaluation is warranted in CH children
with normal tests at age 5 years.
PMID- 10779140
TI - The value of ultrasonography in predicting autoimmune thyroid disease.
AB - Ultrasonography (US) may demonstrate a diffuse reduction in thyroid echogenicity
(low-amplitude echoes) in autoimmune thyroid disease (AITD), which includes
chronic lymphocytic thyroiditis and Graves' disease, as well as in subacute
thyroiditis. The reported occurrence of this finding in AITD varies from 19% to
95%. To assess the validity of diffuse reduction in thyroid echogenicity as a
predictor of AITD, 3,077 patients referred for US of the thyroid were examined
prospectively with regard to reduced versus normal thyroid echogenicity. The most
frequent reasons for referral were goiter, thyroid dysfunction, neck discomfort,
and/or difficulty in swallowing. Ultrasonography demonstrated diffuse reduction
in thyroid echogenicity in 485 patients. Of these, 452 patients had available
records of fine-needle aspiration biopsy (FNAB), and were included in the study.
From the remaining patients, with normal thyroid echogenicity, 100 consecutive
patients were selected as controls. In 411 of the 452 study patients (90.9%)
there was at least one laboratory finding consistent with possible AITD: cytology
indicating lymphocytic thyroiditis, 287 of 363 patients (79.1%) with diagnostic
specimens; elevated levels of peroxidase antibodies (TPOAb), 225 of 337 (66.8%);
elevated thyrotropin (TSH) levels, 290 of 450 (64.4%); or low TSH levels, 79 of
450 (17.6%). The final diagnosis was: chronic autoimmune (Hashimoto's)
thyroiditis in 352 patients; Graves' disease in 47 patients; subacute
(granulomatous) thyroiditis in 7 patients; toxic nodular goiter in 3 patients;
and toxic adenoma in 2 patients. In the remaining 41 patients, those without
laboratory results consistent with AITD, the final diagnosis was colloid goiter
in 37 and thyroid cancer in 4 patients. In the 100 controls, laboratory results
were consistent with possible AITD in 14 patients: elevated TPOAb levels in 5 of
49 patients with retrieved antibody results; lymphocytic thyroiditis in 2
patients; elevated TSH levels in 2 patients; and low TSH levels in 2 patients. In
these controls, the final diagnosis was: chronic autoimmune thyroiditis in 7;
toxic nodular goiter in 6 patients, and toxic adenoma in 1 patient. The
corresponding positive and negative predictive values of reduced thyroid
echogenicity as an indicator of AITD were 399 of 452 (88.3% [95% CI, 85% to
91%]), and 93 of 100 (93.0% [95% CI, 88% to 98%]), respectively. Thus, diffuse
reduction in thyroid echogenicity was a valid predictor of AITD.
PMID- 10779141
TI - Bone metastases from thyroid carcinoma: clinical characteristics and prognostic
variables in one hundred forty-six patients.
AB - To describe the clinical characteristics and define the indicators that best
predict survival in patients with bone metastases from thyroid carcinomas. We
collected data from medical records of 146 patients with documented bone
metastases from thyroid carcinoma seen at our medical center over a 38-year
period. Univariate and multivariate analyses of prognostic indicators for
survival were performed. Bone metastases were present at the initial diagnosis in
47% of patients. Vertebrae (29%), pelvis (22%), ribs (17%), and femur (11%) were
the most common sites of metastases. Multiple lesions were present in 53% of the
cases. The overall 10-year survival rate from the time of diagnosis of thyroid
cancer was 35%, and from diagnosis of initial bone metastasis was 13%. By
univariate analysis from the time of the initial bone metastasis, radioiodine
uptake by skeletal metastases, the absence of nonosseous metastases and treatment
with radioiodine were significant prognostic factors. By multivariate analysis,
radioiodine uptake by skeletal metastases and the absence of nonosseous
metastases were independent favorable prognostic variables for survival. In a
subgroup of patients in which histologic specimens were available and were
reviewed, Hurthle cell carcinoma was the most favorable histologic subtype for
survival with the undifferentiated subtype being the worst. The spread of thyroid
carcinoma to bone is more common in patients over 45 years of age, is usually
symptomatic, and is often multicentric. Overall survival is best in those whose
lesions concentrate radioactive iodine and those who have no nonosseous
metastases.
PMID- 10779142
TI - A clear cell variant of follicular carcinoma presenting as an autonomously
functioning thyroid nodule.
AB - We report a case of an autonomously functioning thyroid nodule (AFTN) that proved
to be almost exclusively a clear cell variant of follicular carcinoma. AFTNs are
generally felt to be benign lesions with exceptions forming the basis of case
reports. Likewise, clear cell tumors of the thyroid are rare. To our knowledge,
this combination of two unusual thyroid conditions has not been previously
reported. The initial scans of this patient were so characteristic for a
degenerating AFTN that attention was first directed toward a very large
contralateral lobe. While it is debatable whether all AFTNs should be biopsied,
on the basis of this and other cases, it is recommended that AFTNs that contain a
central photopenic area on scan be biopsied to be sure that cystic degeneration,
a commonly seen phenomenon in larger AFTNs, is indeed present rather than a
malignancy.
PMID- 10779143
TI - A case of sarcoidosis and sarcoid granuloma, papillary carcinoma, and Graves'
disease in the thyroid gland.
AB - Sarcoidosis is a systemic chronic granulomatous disease of unknown etiology most
commonly affecting young females. The disease was first described in the thyroid
gland in 1938. Our patient, a 27-year-old male with known sarcoidosis, was
referred to the National University Hospital for acute symptoms of thyrotoxicosis
(weight loss of 6 kg, tremor, thyroid enlargement, and tachycardia). Laboratory
findings showed suppressed serum thyrotropin (TSH, <0.03 mU/L [0.5-4.20]),
increased total thyroxine (T4) (223 nmol/L, [60-140]), and triiodothyronine (T3)
(8.5 nmol/L, [1.5-2.7]). Furthermore, Tc-99m pertechnetate scintigraphy disclosed
diffuse accumulation of the isotope confirming the diagnosis of Graves' disease.
During the next 18 months of antithyroid treatment (thiamazole, Thycapzol)
hyperthyroidism was difficult to control, the thyroid gland gradually enlarged,
and surgery was recommended. Initially, the patient declined surgery but after an
additional 18 months, he accepted surgery. During the 36-month period of
antithyroid drug treatment TSH was suppressed (<0.01 mU/L) and T3 often elevated
despite high doses of thiamazole. Total thyroidectomy was performed, and
histologic examination of the removed thyroid tissue confirmed the diagnosis of
Graves' disease and also the presence of sarcoid granuloma and metastatic
papillary adenocarcinoma with spread to neck lymph nodes. Four months later, a
modified radical neck dissection was performed with removal of neck lymph nodes
followed by external radiation therapy (2 Gy x 32 fractions to the neck). The
concomitant presence of sarcoidosis, papillary carcinoma, and Graves' disease in
a thyroid gland, to our knowledge, has not previously been described in the
literature.
PMID- 10779145
TI - Images in thyroidology. Medullary thyroid cancer.
PMID- 10779144
TI - Should you always trust FNA interpretations?
PMID- 10779146
TI - Inducible nitric oxide synthase (iNOS) expression in liver and splenic T
lymphocyte rise are associated with liver histological damage during experimental
hepatitis A virus (HAV) infection in Callithrix jacchus.
AB - Callithrix jacchus is considered a reliable animal model for hepatitis A virus
(HAV) infection. All three HAV orally inoculated marmosets developed hepatitis -
the infection was monitored by continuous virus shedding, high levels of serum
enzyme alanine aminotransferase, specific antibody and seroconversion 3-6 weeks
after HAV inoculation. HAV antigen was detected in liver by immunofluorescence 4
days post inoculation (PI) and onwards. To gain insight into the biological role
of inducible nitric oxide synthase (iNOS) during immune-related acute liver
injury the enzyme was searched in frozen biopsies: immunofluorescent labeling was
found in the cytoplasm of liver cells mainly Kupffer's cells and spleen
macrophages (CD68+) starting 11 days PI with maximum intensity on the fifth to
sixth week PI. Necroinflammatory liver lesions characteristic of viral hepatitis
were also observed at 10 days PI with maximum severity at 4 to 6 weeks PI.
Furthermore, T lymphocytes (CD2+) were raised at this time point. No difference
was evident in the frequency of B lymphocytes (CD20+). Therefore, iNOS expression
preceded necroinflammatory liver lesion and maximal immunofluorescence reaction
was coincident with tissue injury, supporting the hypothesis that NO contributes
to hepatic cytotoxic mechanism but also to virus clearance. The concomitant rise
in T-lymphocyte population may suggest a role for these cells in this and/or
other independent HAV-induced pathological changes.
PMID- 10779147
TI - Effects of dietary fat on benz-a-pyrene-induced forestomach tumorigenesis in mice
chronically exposed to arsenic.
AB - The modulating effect of As (As2O3) in drinking water plus dietary fatty acids on
benzo-a-pyrene (BP) induced forestomach tumorigenesis was assayed in mice fed
with corn oil (CO), Olein (O), palmstearin (PS) and cod liver oil (CLO) enriched
formulae, and a mixed-fat (S-stock) diet during 28 weeks. Neither pre-or
neoplastic lesions were recorded in esophagus or forestomach of mice treated with
As alone. CLO diet showed a protective effect. Indeed, multiple epidermal
hyperplasia were significantly reduced compared to S group and a reduction in
papillomas multiplicity with respect to S, CO and O groups was also observed.
Mice fed on PS formula showed minor papillomas per mouse with respect to CO and
O. These results indicate that As plus BP did not exhibit any synergistic effect
on the development of epidermoid tumor lesions, whereas CLO diet exerted
antipromoting activity . In spite of their common essential fatty acid deficiency
(EFAD) condition, PS and O lots showed contradictory results. Hence, the dietary
enrichment in 18:1 n-9 (O diet) per se, and not the EFAD state, may play a
deleterious role. Corn diet showed no promoting activity on the epidermoid tumor
development in this model.
PMID- 10779148
TI - Retinoblastoma protein in microphthalmic mice.
AB - A microphthalmic strain of mice was used to study immunoresponse of the
retinoblastoma protein. Comparing wild-type, heterozygote and homozygote
microphthalmic eyes, we found an increasing labelling of phosphorylated
retinoblastoma protein (pRb) in the retinal pigment epithelium. Additionally,
microphthalmic eyes expressed pRb in the neuroepithelium. Especially rosettes
were strongly labelled.
PMID- 10779149
TI - Neuronal and inducible nitric oxide synthase distribution in retinas of
microphthalmic mice.
AB - A study about the distribution of neuronal nitric oxide synthase (n-NOS) and
inducible NOS (i-NOS) was performed in microphthalmic retinas at postnatal day
(pd) 2 and pd 7. Neither n-NOS nor i-NOS immunoresponse could be detected at pd
2. At pd 7, i-NOS activity was revealed in the retinas of mi/mi littermates but
not in those of heterozygotes or wild-type littermates. The expression of n-NOS
corresponded to the postnatal retinal development. Retinal rosettes were strongly
labelled.
PMID- 10779150
TI - Lipoxygenase inhibitor FLM 5011, an effective protectant of myocardial
microvessels against ischemia-reperfusion injury? An ultrastructural-morphometric
study.
AB - The lipoxygenase inhibitor FLM 5011 was used for protection of the coronary
microcirculation against ischemia/ reperfusion injury after ligation of the left
coronary artery in dogs. Epimyocardial biopsies from ischemic and non-ischemic
areas of protected and unprotected areas taken before and after ischemia of 90
min duration and after 180 min reperfusion were analysed by means of electron
microscopic morphometry. The ischemic injury consisted in endothelial swelling,
luminal blebbing, and formation of irregular protrusions, partly occurrence of
pericapillary edema and cellular debris. Plasmalemmal vesicles seemed to decrease
in frequency, mitochondria showed focal or generalized degeneration of cristae
and matrix. Reperfusion partly deteriorated the damage, partly restoration of
ultrastructural parameters was to be observed. There were no significant
differences between the infarcted and not infarcted areas. FLM 5011 treatment
reduced the endothelial edema, blebbing and occurrence of pericapillary debris
and stabilized the number of vesicles. The protection of the mitochondrial
cristae and matrix was statistically significant. The results indicate that FLM
5011, under the condition of the experiment, effectively protects the
ultrastructure of essential endothelial structures of myocardial
microcirculation, explained by the blocking of the noxious leucotrienes and
peptidoleucotrienes liberated by the 5-lipoxygenase pathway of the free
arachidonic acid and by scavenging of oxygen free radicals. The results must be
confirmed by further experiments including biochemical and functional parameters.
PMID- 10779151
TI - Hypovolemia in rats increases mortality rates following endotoxin administration.
AB - The aim of the present study was to examine whether acute or chronic hypovolemia
increase the mortality rates of rats following endotoxin injection. Another aim
of this study was to examine whether this increase in sensitivity can be
explained by increased leakage of endotoxin from the digestive tract to the blood
stream. Chronic hypovolemia was caused by water deprivation for 8 days. Acute
hypovolemia was caused by injection of sucrose (300mg/100g) or by hemorrhage of a
volume of up to 2.1 ml/100g. The hypovolemia was examined by measuring the plasma
volume using Evans Blue (EB). Endotoxin at various doses was injected to the
hypovolemic rats and the lethality of the various treatments was examined. Acute
and chronic hypovolemia caused a significant increase inthe mortality rates of
rats injected IP with a dose of 1-1.5 mg/100g endotoxin. Endotoxin administration
(6mg/100g) by drinking to hypovolemic rats did not cause death at all. In
contradistinction, injection of galactoseamine to rats that underwent similar
treatments caused 100% mortality. Endotoxin tolerance reduced the mortality rates
following galactoseamine injection to the control level of administration of
endotoxin without hypovolemia (p < 0.001). Injection of the antibiotic polymixin
B following the galactoseamine injection also decreased mortality rates to 40% (p
< 0.05). Examination of plasma endotoxin concentration exhibited a significant
increase following administration of endotoxin by drinking to hypovolemic rats (p
< 0.001) compared to rats that received the same amount of endotoxin but without
hypovolemia. These results indicate that one possible explanation for the
increased mortality rate of the hypovolemic rats after endotoxin injection is due
to leakage of endotoxin from the digestive tract.
PMID- 10779152
TI - Influence of ochratoxin A and an extract of artichoke on the vaccinal immunity
and health in broiler chicks.
AB - The combined effect of ochratoxin A (at diet levels of 130, 305 and 790 ppb) and
penicillic acid was studied in 100 broiler chicks. Serological investigations
revealed significantly lower haemagglutination inhibiting antibody titers in the
experimental chicks immunized with vaccine against Newcastle disease. A
statistically significant decrease of the body weight and the relative weight of
lymphoid organs as well as a significant increase of the relative weight of
kidneys and liver were seen. The main degenerative changes were observed in the
proximal convoluted tubules in kidneys and slight degenerative changes were found
in the hepatocytes. Degenerative changes and depletion of lymphoid cells were
observed in the bursa Fabricii, thymus, spleen and Peyer's patches of intestinal
mucosa. Serum analyses revealed significant decreases of the total protein and
cholesterol, and significant increases of the uric acid and glucose.
Haematological analyses showed a slight anaemia, leucocytosis and slightly
decompensated metabolic acidosis. A statistically significant protective effect
of 5% total water extract of artichoke on humoral immune response (increase of
haemaglutination inhibiting antibody titer), relative organ weight as well as on
pathomorphological, haematological and biochemical changes induced by ochratoxin
A, was established.
PMID- 10779153
TI - Immunopathological study on the development of swine serum-induced bile duct
lesions in BALB/c and DBA/2 mice.
AB - To compare the difference in the development of swine serum (SS)-induced bile
duct lesion (BDL) between high responder BALB/c and low responder DBA/2 mice, the
mice of both strains injected with SS twice a week for up to 4 weeks were killed
and examined immunopathologically after the 2nd, 4th, 6th and 8th SS-injection,
respectively. In BALB/c mice, BDL developed rapidly following the SS-injections,
and a slight enlargement of common bile ducts accompanied with infiltration of T
helper cells and eosinophils was detected after the 2nd SS-injection. From the
4th injection on, BDL was characterized by proliferation of mucous glands,
hyperplasia and hypertrophy of biliary and glandular epithelial cells, periductal
fibrosis, infiltration of eosinophils, plasma cells and T helper cells, and
increase of mast cells, resulting in more apparent enlargement of common bile
ducts. Several hypertrophied biliary and glandular epithelial cells were positive
for mouse immunoglobulins and SS. BDL subsided after cessation of the SS
treatment. On the other hand, in DBA/2 mice, immune response and inflammatory
reaction were very weak, and only slight BDL were detected.
PMID- 10779154
TI - New animal model of diphtheritic myocarditis.
AB - A new rabbit experimental model was developed in order to study the role of the
lymph system in the pathogenesis of diphtheritic myocarditis. We injected the
diphtheritic toxin into the connective tissue (tela cellularis) of the anterior
mediastinum. (It inevitably drains from there to the lymph vessels of the heart.)
As a result, typical Diphtheritic Myocarditis along with the severe lesion of the
regional lymph nodes of the heart was induced.
PMID- 10779155
TI - Melatonin and colon carcinogenesis. III. Effect of melatonin on proliferative
activity and apoptosis in colon mucosa and colon tumors induced by 1,2
dimethylhydrazine in rats.
AB - Forty-eight two-month-old outbred female LIO rats were injected weekly with a
single dose of 1,2-dimethylhydrazine (DMH; 21 mg/kg of body weight) administered
s.c. for 15 consecutive weeks. From the day of the 1st injection of the
carcinogen the part of rats were given five days a week during the night time
(from 18.00 h to 08.00 h) melatonin dissolved in tap water, 20 mg/l. 10 rats were
treated similarly with solvents and served as control. The experiment was
terminated 6 months after the first injection of the carcinogen. Colon tumors
(mainly adenocarcinomas) developed in a hundred percent of rats exposed both to
DMH or to DMH plus melatonin. However, descending colon carcinomas were observed
in 65 % of rats exposed to DMH plus melatonin against 100% in those exposed to
DMH alone (p < 0.01). The multiplicity of colon tumors was also reduced in rats
under the influence of melatonin. This effect is correlated with the significant
inhibitory effect of the pineal hormone on mitotic index and with stimulating
effect of melatonin on the relative number of apoptotic cells (TUNEL-method) in
colon tumors. Long-term treatment with melatonin was followed also by the
decrease in the area of lymphoid infiltrates in the colon mucosa of tumor-bearing
rats.
PMID- 10779156
TI - Alterations in rat's brain capillaries in a model of focal cerebral necrosis.
AB - Focal brain compression causes cerebral tissue damage. In this study we followed
alterations in capillary ultrastructure in the rat cortex and neurohypophysis
caused by 40 mm Hg compression for 15 minutes. One day after experiment we
observed clogging of capillaries, accumulation of collagen fibrills under the
basement membrane and necrosis or apoptosis of endothelial cells. Four days after
it the basement membrane was multiplicated, blurred and thickened. In the
neurohypophysis the formation of vessels lined with the atypical continuous
endothelium was seen. There was also evidence for the migration of pericytes
through the blurred basement membrane and the differentiation of pericytes into
endothelial cells. Thus, vascular injury in the compressed brain is followed by a
highly ordered sequence of processes in the basement membrane and perivascular
cells leading to capillary repair.
PMID- 10779157
TI - Gene-modified dendritic cells for use in tumor vaccines.
AB - Dendritic cells (DCs) are potent antigen-presenting cells capable of priming
activation of naive T cells. Because of their immunostimulatory capacity,
immunization with DCs presenting tumor antigens has been proposed as a treatment
regimen for cancer. The results from translational research studies and early
clinical trials point to the need for improvement of DC-based tumor vaccines
before they become a more broadly applicable treatment modality. In this regard,
studies suggest that genetic modification of DCs to express tumor antigens and/or
immunomodulatory proteins may improve their capacity to promote an antitumor
response. Because the DC phenotype is relatively unstable, nonperturbing methods
of gene transfer must be employed that do not compromise viability or
immunostimulatory capacity. DCs expressing transgenes encoding tumor antigens
have been shown to be more potent primers of antitumor immunity both in vitro and
in animal models of disease; in some measures of immune priming, gene-modified
DCs exceeded their soluble antigen-pulsed counterparts. Cytokine gene
modification of DCs has improved their capacity to prime tumor antigen-specific T
cell responses and promote antitumor immunity in vivo. Here, we review the
current status of gene-modified DCs in both human and murine studies. Although
successful results have been obtained to date in experimental systems, we discuss
potential problems that have already arisen and may yet be encountered before
gene-modified DCs are more widely applicable for use in human clinical trials.
PMID- 10779158
TI - Combination gene therapy: synergistic inhibition of human immunodeficiency virus
Tat and Rev functions by a single RNA molecule.
AB - Current drug combinations can achieve long-term suppression of HIV replication in
infected individuals. Unfortunately, complicated dosing schedules and high
toxicity make long-term compliance with drug regimens difficult for most
patients. Gene therapy may provide a permanent solution for HIV disease by
generating cells genetically resistant to virus replication. As with the highly
active antiretroviral therapies, genetic drugs must have strong antiviral potency
and the ability to prevent the emergence of escape mutants. We have constructed
antiviral genes containing unique combinations of Tat- and Rev-binding decoys.
The new antiviral molecules are chimeric TAR-RRE RNAs that are expressed only in
HIV infected cells in a Tat-regulated manner. One RNA molecule competes for both
Tat and Rev binding, and thus blocks the activation and the expression of all
viral genes. The two functional Tat- and Rev-binding domains exhibit the highest
synergy at the lowest concentration. Conservative quantitative estimates of this
synergistic effect were I = 0.24 at 50% inhibition, in terms of the Berenbaum
"interaction index," indicating that the combined construct was approximately
fourfold more potent than would be predicted on the basis of additive effects.
The possibility of HIV escape from this inhibition is unlikely, because it
requires simultaneous mutation of TAR and RRE in a manner in which both Tat and
Rev preserve their respective functions. TAR-RRE combination decoys represent the
first example of mathematically proven synergistic antiviral activity between two
domains of the same molecule.
PMID- 10779159
TI - A hyperfusogenic gibbon ape leukemia envelope glycoprotein: targeting of a
cytotoxic gene by ligand display.
AB - An important goal in cancer gene therapy is the development of novel targeted
cytotoxic genes. The observation that transfection of a GaLV envelope
glycoprotein lacking an R peptide into human cells results in considerable cell
cell fusion and subsequent cell death prompted us to explore the potential for
using this fusogenic membrane glycoprotein (FMG) as a targeted cytotoxic gene. As
proof of principle, we therefore displayed epidermal growth factor (EGF) on the N
terminus of GaLV envelope glycoproteins both with and without an R peptide (GaLV
R+ and GaLV R-). Transfection of the GaLVR+ envelope expression plasmids did not
cause cell-cell fusion. The GaLV R+ envelopes were incorporated into retroviral
vectors whose infectivity was investigated on EGF receptor-positive and -negative
cells. The vector incorporating an N-terminally unmodified envelope was able to
infect all human cell lines tested. Infectivity of the vector incorporating an
envelope on which EGF was displayed was restricted on EGF receptor-positive cells
(but not on EGF receptor-negative cells) and could be restored by protease
cleavage of the displayed domain or competition with exogenous ligand. The cell
cell fusion capacity of the GaLV R- envelope glycoproteins (N-terminally
unmodified and with N-terminal display of both EGF and insulin-like growth factor
I [IGF-I]) was investigated by plasmid DNA transfection. While the N-terminally
unmodified GaLV R- fused all human cell types tested, fusogenicity of GaLV R- on
which EGF or IGF-I was displayed was considerably restricted on receptor-positive
cells. "Reciprocal" competition experiments showed that fusogenicity could be
restored by competition only with the relevant exogenous ligand. Thus the
specificity of cell-cell fusion by a hyperfusogenic GaLV envelope glycoprotein
can be regulated by N-terminal display of growth factor ligands. There is
therefore significant potential for further development of the targeting of the
cell-killing capability of this fusogenic viral glycoprotein by using strategies
similar to those we have developed for the targeting of retroviral vectors.
PMID- 10779160
TI - Immune responses against replication-deficient adenovirus inhibit ovalbumin
specific allergic reactions in mice.
AB - Replication-deficient adenovirus vector (Ad) is one of the most efficient gene
transfer vehicles for human gene therapy. However, Ad is antigenic, known to
evoke prominent inflammatory responses in vivo, and there are concerns that using
Ad in patients with immune-mediated disorders (allergy and autoimmune diseases)
may affect the status of the diseases. To evaluate this concept in a manner close
to clinical scenarios, a mouse model of airway eosinophilic inflammation was
developed by administering intraperitoneal injections and inhalations of chicken
ovalbumin (OA), with Ad administered intranasally 5 days after the OA
sensitization. The administration of Ad resulted in a significant suppression of
eosinophil counts in peripheral blood as well as in the bronchoalveolar lavage
fluid (BALF), and a decrease in OA-specific IgE. The decrease in the number of
eosinophils in BALF was associated with a marked upregulation of interferon gamma
(IFN-gamma) expression. In contrast, the Ad-specific, delayed-type
hypersensitivity response and efficacy of reporter gene expression mediated by Ad
were only marginally affected in animals sensitized with OA. Together, these data
support the idea that Ad administration in patients with Th2-mediated immune
disorders does not exacerbate the parameters of ongoing inflammations or gene
transfer efficiency, and with its ability to induce prominent type 1 immune
response to the antigen in vivo, Ad could potentially be used as an efficient
adjuvant to control immune disorders where Th2 cell-mediated mechanisms are
involved.
PMID- 10779161
TI - Immunogenetic therapy of human melanoma utilizing autologous tumor cells
transduced to secrete granulocyte-macrophage colony-stimulating factor.
AB - We performed a clinical study of five patients with melanoma to evaluate the
immunobiological effects of retrovirally transduced autologous tumor cells given
as a vaccine to prime draining lymph nodes. Patients were inoculated with both
wild-type (WT) and GM-CSF gene-transduced tumor cells in different extremities.
Approximately 7 days later, vaccine-primed lymph nodes (VPLNs) were removed.
There was an increased infiltration of dendritic cells (DCs) in the GM-CSF
secreting vaccine sites compared with the WT vaccine sites. This resulted in a
greater number of cells harvested from the GM-CSF-VPLNs compared with the WT
VPLNs at a time when serum levels of GM-CSF were not detectable. Four of five
patients proceeded to have the adoptive transfer of GM-CSF-VPLN cells secondarily
activated and expanded ex vivo with anti-CD3 MAb and IL-2. One patient had a
durable complete remission of metastatic tumor. Utilizing cytokine (IFN-gamma, GM
CSF, IL-10) release assays, GM-CSF-VPLN T cells manifested diverse responses when
exposed to tumor antigen in vitro. In two of two patients, GM-CSF-VPLN T cell
responses were different from those of matched WT-VPLN cells. This study
documents measurable immunobiologic differences of GM-CSF-transduced tumor cells
given as a vaccine compared with WT tumor cells. The complete tumor remission in
one patient provides a rationale to pursue this approach further.
PMID- 10779162
TI - Antigen-specific induction of peripheral T cell tolerance in vivo by codelivery
of DNA vectors encoding antigen and Fas ligand.
AB - Fas ligand (FasL, CD95L) induces apoptosis in activated T cells with upregulated
Fas (CD95) expression through the process termed activation-induced cell death
(AICD). We postulated that coexpression of antigen and FasL within individual
antigen-presenting cells would lead to antigen-specific activation of T cells and
to their consequent deletion by FasL-mediated AICD. A DNA-gelatin coacervate
containing transferrin cell ligand, calcium, and the lysosomatropic agent
chloroquine, a formulation previously shown to achieve high-level transfection of
immune and muscle cells in vivo, was used to codeliver plasmids encoding FasL and
antigen. Mice developed a strong cytolytic T cell response to beta-Gal when
injected with DNA encoding beta-galactosidase (LacZ) model antigen, either as
naked DNA or DNA nanoparticles, but failed to respond when there was concomitant
injection of nanoparticles containing both the LacZ and murine FasL DNA vectors.
This loss of T cell response was systemic, specific for beta-Gal, complete when
nanoparticles were administered before antigen challenge, and decreased the T
cell response from prior immunization with LacZ DNA. In effect, this
"tolerization" injection induced antigen-specific peripheral tolerance in study
mice, and represents a possible approach to the treatment of autoimmune diseases
and transplantation rejection.
PMID- 10779163
TI - Prolonged expression and effective readministration of erythropoietin delivered
with a fully deleted adenoviral vector.
AB - Helper-dependent (HD) adenoviral (Ad) vectors, in which all viral coding
sequences are deleted, have been generated. We show here that intravenous
delivery of a mouse EPO (mEPO) expression cassette cloned in an HD vector in
immunocompetent mice is effective and long lasting, but not permanent. A precise
dose-response relationship between the dose of injected virus and stable EPO
serum levels was observed, together with a 100-fold increase in gene expression
per infectious particle when compared with a first-generation Ad vector bearing
the same cassette. As a direct consequence, therapeutic increases in hematocrit
that lasted more than 6 months were achieved with minute amounts of virus, which
caused no detectable production of neutralizing antibodies. Intravenous
readministration of the HD-mEPO vector in the same mice was as effective as in
naive animals without any need for prior immunosuppression. Finally, HD-mEPO
injection in subtotally nephrectomized rats improved the anemic status induced by
surgery. HD Ad vectors are thus excellent tools for EPO gene therapy.
PMID- 10779164
TI - Photochemical transfection: a new technology for light-induced, site-directed
gene delivery.
AB - The development of methods for specific delivery of therapeutic genes into target
tissues is an important issue for the further progress of in vivo gene therapy.
In this article we report on a novel technology, named photochemical
transfection, to use light to direct a precise delivery of therapeutic genes to a
desired location. The technology makes use of photosensitizing compounds that
localize mainly in the membranes of endosomes and lysosomes. On illumination
these membrane structures will be destroyed, releasing endocytosed DNA into the
cell cytosol. Using a green fluorescent protein gene as a model we show that
illumination of photosensitizer-treated cells induces a substantial increase in
the efficiency of transfection by DNA-poly-L-lysine complexes. Thus, in a human
melanoma cell line the light treatment can increase the transfection efficiency
more than 20-fold, reaching transfection levels of about 50% of the surviving
cells. In this article various parameters of importance for the use of this
technology are examined, and the potential use of the technology in gene therapy
is discussed.
PMID- 10779165
TI - Partial correction of murine hemophilia A with neo-antigenic murine factor VIII.
AB - We have previously reported a factor VIII knockout (FVIII KO) mouse model for
hemophilia A. Here we demonstrate the presence of nonfunctional heavy chain
factor VIII protein in the mouse, making it an excellent model for cross-reacting
material (CRM)-positive hemophilia A patients, who express normal levels of a
dysfunctional FVIII protein. We attempted to correct these mice phenotypically by
transduction of wild-type mouse factor VIII cDNA delivered in an E1/E3-deleted
adenoviral vector by tail vein injection. All treated mice displayed initial high
level FVIII expression that diminished after 1 month. Ten of 12 mice administered
between 6 x 10(9) and 1 x 10(11) particles/mouse along with anti-CD4 antibody
showed long-term FVIII activity (0.03-0.05 IU/ml, equivalent to 3-5% of normal
FVIII) that corrected the phenotype. Wild-type murine FVIII was a neo-antigen to
the KO mice, generating both cytotoxic and humoral immune responses. Immune
suppression with anti-CD4 antibody abrogated these immune responses. These data
demonstrate that despite the presence of endogenous FVIII protein the immune
system still recognizes a species-specific transgene protein as a neo-antigen,
eliciting a cytotoxic T cell response. This phenomenon may exist in the treatment
of other genetic disorders by gene therapy.
PMID- 10779166
TI - Modified human immunodeficiency virus-based lentiviral vectors display decreased
sensitivity to trans-dominant Rev.
AB - As a first step toward the development of HIV-based conditionally replicating
defective interfering particles expressing trans-dominant Rev (TdRev), we studied
whether mutation of the splicing signals and replacement of the RRE by the SRV-1
CTE would render these vectors less sensitive to TdRev. Vectors with mutations in
the splicing signals (SD-/RRE+) yielded high titers (5 X 10(6) CFU/ml) and showed
higher levels of cytoplasmic unspliced mRNA than the corresponding SD+/RRE+
vectors either in the absence of Rev, in the presence of TdRev, or in the
presence of both TdRev and Rev. Proviral copies of SD-/RRE+ vectors were rescued
more efficiently than SD+/RRE+ vectors when TdRev was expressed. Vectors with the
SRV-1 CTE (SD+/CTE+ and SD-/CTE+) expressed high levels of cytoplasmic unspliced
mRNA in the absence of Rev expression. Titers obtained with the SD-/CTE+ vectors
(10(6) CFU/ml) were higher than the titers obtained with SD+/CTE+ vectors. We
also tested the effect of other structural modifications such as the orientation
of the expression cassette and the presence of the central polypurine tract
(cPPT/CTS). We show that an expression cassette cloned in the reverse orientation
with respect to the LTRs or elimination of the cPPT/CTS element severely affected
vector titers. We also demonstrated that these vectors can be efficiently
mobilized from their proviral state by HIV trans-complementing functions, and
transduced into secondary target cells without suffering any genomic
rearrangement.
PMID- 10779167
TI - Muscle transfection by electroporation with high-voltage and short-pulse currents
provides high-level and long-lasting gene expression.
AB - Gene transfer into muscle by electroporation with low-voltage and long-pulse
(LV/LP, 100 V/50 msec) currents was shown to be more efficient than simple
intramuscular DNA injection. Nevertheless, transgene expression declined from day
7 and only reached 10% of the maximum 3 weeks after electroporation. We have
optimized electroporation conditions including voltage, pulse number, and the
amount of injected luciferase-encoding plasmid DNA in the tibialis anterior
muscle. Using high-voltage and short-pulse (HV/SP, 900 V/100 microsec) currents,
we observed an average 500-fold increase in luciferase expression, in comparison
with nonelectroporated muscle. Moreover, sustained and long-lasting gene
expression was observed for at least 6 months. When we compared HV/SP currents
with LV/LP currents, luciferase expression was similar 24 hr after
electroporation. One month later, whereas luciferase expression was stable in
muscle electroporated with HV/SP currents, it decreased 600-fold in muscle
electroporated with LV/LP currents. In conclusion, electroporation with high
voltage and short-pulse currents provides high-level and long-lasting gene
expression in muscle.
PMID- 10779168
TI - Human gene marker/therapy clinical protocols.
PMID- 10779169
TI - Structural organization of nicotinic acetylcholine receptors.
AB - Nicotinic acetylcholine receptor of the electric ray Torpedo is the most
comprehensively characterized neurotransmitter receptor. It consists of five
subunits (alpha2beta gammadelta) amino acid sequences of which were determined by
cDNA cloning and sequencing. The shape and size of the receptor were determined
by electron cryomicroscopy. It has two agonist/competitive antagonist binding
sites which are located between subunits near the membrane surface. The receptor
ion channel is formed by five transmembrane helices (M2) of all five subunits.
The position of the binding site for noncompetitive ion channel blockers was
found by photoaffinity labelling and site-directed mutagenesis. The intrinsic
feature of the receptor structure is the position of the agonist/competitive
antagonist binding sites in close vicinity to the ion channel spanning the
bilayer membrane. This peculiarity may substantially enhance allosteric
transitions transforming the ligand binding into the channel opening and
physiological response. Muscle nicotinic acetylcholine receptors from birds and
mammals are also pentaoligomers consisting of four different subunits (alpha2beta
gammadelta or alpha2beta epsilondelta) with high homology to the Torpedo
receptor. Apparently, the pentaoligomeric structure is the main feature of all
nicotinic, both muscle and neuronal, receptors. However, the neuronal receptors
are formed only by two subunit types (alpha and beta) or are even pentahomomers
(alpha7 neuronal receptors). All nicotinic receptors are ligand-gated ion
channel, the properties of the channels being essentially determined by amino
acid residues forming M2 transmembrane fragments.
PMID- 10779170
TI - Structure and mechanisms of function of visual system proteins.
AB - Recent progress in understanding visual signal transduction in retinal cells is
summarized. The roles of particular proteins in activation, amplification and
termination of the photoresponse are described. Detailed information on the
structure and function of the photoreceptor protein rhodopsin is presented. The
latest data on visual pigment sequences, rhodopsin mutations in the autosomal
dominant retinitis pigmentosa, and the results of site-directed mutagenesis of
the rhodopsin molecule are summarized.
PMID- 10779171
TI - Phototransduction and calcium.
AB - In the early 1970s it became clear that an unknown intracellular messenger
participated in signal transduction in retinal rod cells. Ca2+ and cGMP had been
considered as candidates for such a messenger until 1985 when the cGMP-gated
conductance of the plasma membrane was discovered. However, for the last several
years, Ca2+ has taken revenge as a signal molecule which contributed to the
processes underlying the photoreceptor cell recovery. This review describes the
overall picture of phototransduction molecular mechanisms with special emphasis
on participation of Ca2+ in visual cell signalling.
PMID- 10779172
TI - Integrins: structure and functions.
AB - Integrins are cell surface transmembrane glycoproteins which perform receptor
functions in cell interactions with the extracellular matrix and cell-cell
contacts. Another function of integrins is transduction of signals which mediate
the effects of the matrix on the physiological activity of cells (motility,
proliferation, differentiation, etc.). Contemporary views on the molecular
structure of integrins and their involvement in the organization of the
cytoskeleton and control of gene activity are presented. Biochemical mechanisms,
by which the signal functions of integrins are realized, are discussed. The data
on the participation of integrins in oncogenic cell transformation, metastasis,
and apoptosis are analyzed.
PMID- 10779173
TI - A new level of hormonal signal transduction: primary nuclear action of protein
and peptide hormones.
AB - Contemporary data on the possibility of primary nuclear action of protein and
peptide hormones are analyzed and summarized. Experimental data on the nuclear
accumulation of protein and peptide hormones and their receptors, ligand
dependence of nuclear translocation of membrane receptors, intranuclear
distribution of membrane receptors, and dependence of nuclear accumulation of
membrane receptors on the cell type are discussed. Evidence and hypothesis on the
possible mechanisms of intracellular and transnuclear transport of protein and
peptide hormones and their receptors, and association of nuclear translocation
with cell proliferation are presented. Putative mechanisms of realization of the
signal functions of protein and peptide hormones in the nucleus, including
activation of autonomous nuclear signal cascades and phosphorylation of nuclear
proteins, and the possibility of direct interaction of the nuclear pool of
membrane receptors with transcription factors and DNA are analyzed. A possible
biological role of primary nuclear action of protein and peptide hormones is
discussed.
PMID- 10779174
TI - Membrane receptors and intracellular calcium.
AB - The mechanisms of Ca2+ level regulation in the cytoplasm by neurotransmitters,
hormones, and growth factors and described. The role of G-proteins, second
messengers and protein kinases in the regulation of activity of Ca2+ channels and
pumps is discussed. The contributions of the endoplasmic reticulum, plasma
membrane, nucleus, mitochondria and other intercellular compartments to the
increase in the cytoplasmic Ca2+ concentration are estimated. The data concerning
the relationships between the activities of systems of active and passive Ca2+
transport across the membrane are reviewed. The general mechanisms of
intracellular Ca2+ oscillation are summarized, and a possible role of this
process in the neuroendocrine signal transduction is discussed.
PMID- 10779175
TI - Molecular mechanisms of action of prostaglandin E2 in the regulation of water
osmotic permeability.
AB - The functional role and molecular mechanisms of action of prostaglandin E2 (PGE2)
in the regulation of water osmotic permeability in osmoregulatory epithelia
(mammalian collecting tubules and amphibian urinary bladder) are considered. The
paper describes the modern classification of PGE2 receptors, their distribution
along a nephron and receptor-coupled intracellular second messenger systems. The
mechanism of the inhibitory action of PGE2 on the antidiuretic hormone-induced
enhancement of water osmotic permeability is analyzed. Special attention is given
to the role of PGE2 as an auto- or paracrine regulator of water osmotic
permeability in the phenomenon of ADH-independent increase of water permeability
observed in an isolated amphibian urinary bladder in replacements of the
surrounding serous solution. It is concluded that the osmoregulatory epithelium
is not only a place of the maximum level of PGE2 synthesis in the kidney but is
also characterized by a great diversity of PGE2 receptor subtypes: EP1, EP2, EP3
and EP4 have been revealed in the mammalian collecting tubules. Such a diversity
of PGE2 receptors is in a good agreement with different functional effects of
PGE2 in the osmoregulatory epithelium. The data considered suggest that PGE2 is
not less important in the regulation of water and ion transport in the
osmoregulatory epithelium than antidiuretic hormone.
PMID- 10779176
TI - The role of sphingomyelin cycle metabolites in transduction of signals of cell
proliferation, differentiation and death.
AB - Sphingomyelin cycle metabolites ceramide, sphingosine and sphingosine 1-phosphate
play an important role in cell proliferation, differentiation, reception,
oncogenesis and apoptosis. Ceramide is an intracellular second messenger for
apoptosis activating proteases and specific phosphatases. Sphingosine is an
endogenous inhibitor of protein kinase C and has an inhibitory effect on many
cell functions depending on the activity of this enzyme. On the other hand,
sphingosine can activate other kinases depending on the concentration, cell type
and nature of a stimulus and release Ca2+ from intracellular stores thereby
regulating cell proliferation. Sphingosine induces apoptosis and its level is
increased in cells as a result of action of apoptotic inducers. A phosphorylated
product of sphingosine, sphingosine 1-phosphate, mediates the mitogenic signal,
induces Ca2+ mobilization and protects cells from apoptosis resulting from
elevation of ceramide. The quantitative levels of sphingomyelin metabolites in
the cell determine the dynamic balance between the apoptotic and mitogenic
signals.
PMID- 10779177
TI - Regulation of the conductance and resting potential by extracellular K+ in frog
taste receptor cells.
AB - The effect of extracellular K+ on membrane currents was investigated by the patch
clamp and fast perfusion techniques in frog (Rana temporaria) taste receptor
cells (TRCs). When added to the bath, K+ increased the TRC conductance. The
integral current and current fluctuations depended on the K+ concentration (2.5
90 mM) in the manner which suggested extracellular K+ to serve as a ligand
activating ionic channels (potassium-activated (PA) channels). The influence of
different ions on the PA current reversal potential indicated that the
responsible channels are mainly permeable to K+ and H+. Relative permeabilities
were estimated as P(H):P(K) = 3600:1. With 110 mM KCl in the patch pipette and
110 mM NaCl in the bath, isolated TRCs exhibited the resting potentials from -75
to -65 mV. When raised from 2.5 to 110 mM, extracellular K+ intensively
depolarized TRCs. Membrane potential vs. K+ concentration displayed a slope of
about 41 mV per logarithmic unit. This indicates that the K+ permeability of the
TRC membrane dominates the other in setting the potential. With 10 mM K+ in the
bath, the PA channels were the major contributor to setting the TRC resting
potential. External K+ markedly increased the sensitivity of isolated TRCs to
bath solution pH due to the activation of the PA channels suggesting their role
in sour transduction.
PMID- 10779178
TI - Genetic patterning of embryonic inner ear development.
AB - The commitment of the otocyst to form balance (pars superior) and hearing (pars
inferior) receptors is under the control of patterning genes. Intersecting
patterns of gene expression has been proposed to explain the regionalization of
inner ear sensory receptor development. Insights into the roles of patterning
genes is being acquired from the analysis of inner ear development of null
mutation mice. An example of the consequences of the loss of expression of a
single patterning gene is the effect of a null mutation of paired-box gene 2
(Pax2) on formation of the cochlea. Pax2 transcripts are expressed in the pars
inferior of the otocyst and null mutant inner ears show agenesis of the cochlea.
This is an example of the profound effect that loss of a single patterning gene
can have on inner ear development. However, more typically there is redundancy of
gene action during inner ear development as exemplified by the overlapping
pattern of expression of two closely related homeobox-containing genes (i.e. Hmx2
and Hmx3) in the pars superior of the otocyst. Hmx2 and Hmx3 genes are both
expressed early in otic development with Hmx3 transcripts present in the placode.
However, null mutation of the Hmx3 patterning gene produced only a limited
vestibular defect, and did not result in the agenesis of the vestibule. This
result suggests that there is redundancy in genes that have similar patterns of
regional expression in the otic anlagen.
PMID- 10779179
TI - Effect of carbon dioxide on cochlear blood flow in guinea pigs.
AB - The influence of carbon dioxide (CO2) on cochlear blood flow (CBF), blood
pressure (SBP) and skin blood flow (SBF) was studied in anaesthetized guinea
pigs. A transient acute respiratory acidosis was produced by inhalation of CO2
and oxygen (O2) gas mixtures. The blood flows were measured by laser Doppler
flowmetry (LDF). High CO2 increased CBF and SBP, and decreased SBF in a dose
dependent manner. The responses of CBF, SBP and SBF to high CO2 were reversible.
Our results indicate that high CO2 (and low pH) dilates the smooth muscle of the
blood vessels, resulting in an increase in CBF. CO2 also activates the
sympathetic nervous system in the whole body, producing an increase in SBP. The
distribution of alpha-adrenergic fibres receptors is abundant in skin and scarce
in the cochlea. The constrictive effect on blood vessels is much greater in the
skin than in the cochlea, thus our results showed a decrease in SBF during
stimulation with higher CO2.
PMID- 10779180
TI - Intense noise-induced apoptosis in hair cells of guinea pig cochleae.
AB - Cells can die by two distinct pathways: apoptosis and necrosis. To explore
whether intense noise can induce hair cell (HC) death via the apoptotic pathway,
we systematically examined morphological changes in guinea pig cochlear HC nuclei
stained with Hoechst 33342, a fluorescent dye specifically labelling the nuclear
DNA. A narrow band noise centred at 4 kHz with levels at 110 dB, 115 dB or 120 dB
(SPL) was applied for 4 h and the exposed cochleae were collected at various
intervals (3 h, 3 or 14 days) after the noise exposure. Auditory function was
monitored by measuring thresholds of auditory brain stem responses. In the noise
damaged cochleae, there were two major types of nuclear changes, nuclear
condensation appeared as karyorrhexis or karyopyknosis and nuclear swelling.
Karyorrhexis and karyopyknosis predominately appeared in the severely damaged
cochlear region in the animals exposed to 120 dB noise and examined 3 h after the
noise exposure. In contrast, swelling of nuclei occurred in all of the noise
exposed cochleae, and was the feature change in the animals exposed to 110 and
115 dB noise. This pathological change persisted at least for 14 days after the
noise exposure. The typical changes of karyorrhexis and karyopyknosis noted in
the animals exposed to 120 dB noise were morphologically similar to those nuclear
changes described in previous studies for apoptosis, suggesting that the
apoptotic process may be involved in intense noise-induced HC death.
PMID- 10779181
TI - Effects of betahistine metabolites on frog ampullar receptors.
AB - Previous studies have demonstrated that betahistine, an histamine-like substance
used widely as an anti-vertigo drug, can decrease ampullar receptor resting
discharge without affecting their mechanically evoked responses. Pharmacokinetic
studies have shown that this drug is transformed, mainly at the hepatic level,
into aminoethylpyridine (M1), hydroxyethylpyridine (M2), then excreted with the
urine as pyridylacetic acid (M3). The goal of the present study was to
investigate whether betahistine metabolites are also able to affect vestibular
receptor activity. Results demonstrated that, in the range tested (10(-7)-10(-2)
M), M2 and M3 exerted no effect, whereas M1, at concentrations higher than 10(-6)
M, was able to reduce the resting discharge of ampullar receptors without
affecting the evoked responses. M1 therefore exerts effects similar to those of
betahistine on ampullar receptors. This might be of some clinical interest. On
the basis of our data, the hypothesis may be put forward that the anti-vertigo
action of betahistine is at first achieved by betahistine itself and then
sustained by M1.
PMID- 10779182
TI - Localization of soluble guanylate cyclase activity in the guinea pig inner ear.
AB - The aim of this study was to characterize the nitric oxide (NO) receptor soluble
guanylate cyclase (sGC), to determine the cells targeted by NO and to elucidate
the function of the NO/cGMP pathway in the inner ear. sGC activity in the inner
ear was localized by immunohistochemical detection of NO-stimulated cGMP. Soluble
guanylate cyclase activity in the cochlea was detected in the nerve endings
underneath the outer and inner hair cells, supporting cells, stria vascularis and
vessels. In the vestibular organs, sGC activity was detected in the cytoplasm of
sensory cells, nerve fibres, dark cells and transitional cells and vessels. These
findings suggest that the NO/cGMP pathway may be involved in regulatory processes
in neurotransmission, blood flow and inner ear fluid homeostasis.
PMID- 10779183
TI - Direct evidence of nitric oxide production in guinea pig vestibular sensory
cells.
AB - Production of nitric oxide (NO) in the vestibular organ of the guinea pig was
investigated using the new fluorescence indicator, DAF-2DA, for direct detection
of NO. The utricular maculae and isolated vestibular sensory cells were examined
to locate NO production sites. The fluorescence intensity of the sensory cells
was augmented by stimulation with L-arginine, and significantly increased after
inoculation with LPS. This is the first direct evidence of NO production in the
vestibular end organs. NO may play an important role for the vestibular
physiology and also be involved in disease of the inner ear.
PMID- 10779184
TI - Paraspinal muscle response to electrical vestibular stimulation.
AB - Galvanic (electrical) vestibular stimulation (GVS) has been used to study the
role of the vestibular system in postural control by inducing postural sway in
standing subjects. The purpose of this study was to determine the timing and
pattern of activation in the paraspinal muscles in response to GVS and to compare
these responses with those in the muscles of the lower leg. Binaural-bipolar GVS
was applied to the skin overlying the mastoid processes of 10 subjects while they
stood on a force plate with their eyes closed. The stimulus consisted of a 0.6 mA
5-pulse sequence. Each pulse lasted for 2 s, followed by 4 s of rest. The centre
of pressure (COP) vs. time for each trial was calculated from the reaction forces
and moments. Surface electromyographic (EMG) signals from the paraspinal and
gastrocnemius muscles were recorded bilaterally. The EMG signals were rectified
and integrated (iEMG). The iEMG from the muscles on the cathodal side of the body
were then subtracted from the iEMG of the anodal side muscles, to yield a
differential EMG (dEMG). Both the paraspinal and gastrocnemius muscles became
activated in response to the stimulus. The pattern of activation was consistent
with the changes observed in the centre of pressure. The primary response in both
muscles acted to move the body toward the anode. This primary response began at
74 +/- 20 ms in the paraspinal muscles and at 118 +/- 18 ms in the gastrocnemius.
A second component of the response began at 232 +/- 27 ms in the paraspinal
muscles and 262 +/- 54 ms in the gastrocnemius muscles. This second phase of the
response was opposite in direction to the primary response and was responsible
for decelerating the body and maintaining the deviated position of the centre of
mass over the base of support. Following the termination of the stimulus, the
opposite pattern of muscle activation in both the paraspinal and the
gastrocnemius muscles was observed. The results of this study suggest that the
paraspinal muscles may play a significant role in the frontal plane response to
vestibular stimulation during stance in humans.
PMID- 10779185
TI - Auditory cortical responses in patients with Bell's palsy.
AB - We recorded auditory evoked magnetic responses with a whole-scalp 122-channel
SQUID neuromagnetometer in 14 patients with Bell's palsy (9 with left-sided and 5
with right-sided) and in 10 controls. The stimuli were 50-ms 1-kHz tone bursts,
delivered first to the left and then to the right ear at interstimulus intervals
(ISIs) of 1, 2 and 4 s. In patients, the N100m, the 100-ms response originating
in the auditory cortices peaked, on average, 8 ms earlier and the response
strengths were, on average, 7 nAm stronger over the contralateral than
ipsilateral hemisphere. The response latencies and strengths did not differ
significantly from those of controls and there were no significant differences in
response latencies and strengths between the stimulation of the affected and
healthy side. On average, the response latencies and strengths increased as a
function of ISI over both hemispheres both in patients and in controls. These
findings suggest that Bell's palsy is an isolated peripheral neuropathy that does
not affect the function of the auditory pathways.
PMID- 10779186
TI - Audiometric characterization of a family with digenic autosomal, dominant,
progressive sensorineural hearing loss.
AB - In this study, a non-syndromic progressive bilateral high frequency hearing loss
is described in a family with 141 identified members. Recent genetic analyses
indicated a digenic inheritance with linkage to the gene loci DFNA2 and DFNA12.
The affected family members who shared haplotypes at both loci (type I) showed an
early postlingual onset and a more rapid rate of progress compared with those
with one either of the two disease associated haplotypes (type II). The
audiometric pattern was cochlear without a vestibular involvement. Auditory
brainstem response audiometry and magnetic resonance imaging indicated normal
retrocochlear features. The otoacoustic emissions were affected for both type I
and type II, whereas the acoustic stapedius reflex thresholds were normal in most
cases. It is concluded that both types had an outer hair cell/micro-mechanical
abnormality, but that the DFNA 2 type might have an additional dysfunction at the
level of the inner hair cells. It is furthermore pointed out that the application
of refined audiometric techniques as well as a further development of new
techniques is needed in order to characterize the phenotypes of the rapidly
expanding number of genetically defined inner ear abnormalities.
PMID- 10779187
TI - Expression of human beta-defensin 1 mRNA in human nasal mucosa.
AB - Antimicrobial peptides are cationic proteins that are found in a wide range of
organisms. Recent reports suggested that human beta-defensin 1 (hBD-1), a
prominent group of antimicrobial peptides, is an important component of the
innate immune response, particularly at mucosal surfaces that are vulnerable to
colonization by potential pathogens. Therefore, hBD-1 may participate in
providing intrinsic nasal mucosal defence against microbial infections. The
present study aimed to look for hBD-1 mRNA in human nasal mucosa without obvious
signs of inflammation. Total RNA was isolated from human inferior turbinate
mucosa and hBD-1 mRNA was detected in these tissues by using reverse
transcription and polymerase chain reaction (RT-PCR). By in situ hybridization,
hBD-1 mRNA was predominantly localized in superficial epithelial cells and
submucosal glandular epithelium of human inferior turbinate mucosa. These data
suggest that nasal epithelia and submucosal glands may secrete hBD-1,
contributing to the mucosal defences of the nose.
PMID- 10779188
TI - Effect of intranasal treatment with capsaicin on the recurrence of polyps after
polypectomy and ethmoidectomy.
AB - The aim of this study was to evaluate the influence of five intranasal
applications of capsaicin, performed after endoscopic polypectomy associated with
partial middle turbinectomy and anterior ethmoidectomy, on the recurrence of
nasal polyps and the intensity of nasal obstruction and rhinorrhea. Fifty-one
patients (19 females, 32 males, mean age 43 years) suffering from nasal polyposis
for more than 1 year were included in this double blind, randomized, placebo
controlled study. During post-surgical controls, local anaesthesia and
vasoconstriction of the middle meatus area were performed in all patients with a
cotton pellet soaked with lidocain and adrenaline. In 29 patients, the same type
of cotton pellet soaked with capsaicin (3 x 10(-6) mol. dissolved in 70% ethanol)
was left into the middle meatus of both nostrils for 20 min. As a control group,
22 patients, matched for age and sex, were treated with the capsaicin vehicle
alone (70% ethanol). All patients studied received the intranasal treatment once
a week for 5 weeks. Subjective evaluations of nasal airway resistance (NAR) and
rhinorrhea were recorded by means of a visual analogue scale. Clinical staging of
the nasal polyposis (graded from stage 0 = absence of polyp to stage 3 = polyps
occupying the entire nasal cavity) was evaluated by the same ENT specialist (ZW)
using a 0 degrees endoscope. All parameters were recorded for each patient 1 week
before surgery, then once a month for 9 months. Patients treated by endoscopic
surgery followed by intranasal capsaicin application, reported a marked reduction
in their NAR compared with the pretreatment evaluation (p<0.001). In contrast,
patients treated with the vehicle alone did not have any significant improvement
of their subjective NAR. Subjective rhinorrhea was not modified by either
treatment. Patients treated with capsaicin showed a significant smaller staging
of their nasal polyposis compared with the control group (p<0.001). These
observations suggest that endoscopic surgery followed by intranasal capsaicin
application reduces polyps and nasal obstruction recurrence and could be an
alternative treatment to expensive corticosteroids in developing countries.
PMID- 10779189
TI - Nasal histamine reactivity; relationships to skin-test responses, allergen
provocation and symptom severity in patients with long-continuing allergic
rhinitis.
AB - It has been reported that skin-test reactivity and rhinitis symptom severity
weaken in the course of time. A corresponding weakening might also be seen in non
specific nasal hyper-reactivity, but the relationships of these responses are
poorly understood. Our aim was to measure nasal responsiveness to histamine in a
series of patients with long-continuing allergic rhinitis and to compare these
measurements with skin test responses, allergen provocation and changes in
severity of allergic rhinitis symptoms. A total of 73 patients in whom allergic
rhinitis had been verified over 20 years earlier were re-interviewed and re
investigated. Skin prick tests with common allergens were performed and the
presence of nasal allergy was confirmed by allergen provocation. Non-specific
nasal hyper-reactivity was determined with nasal histamine challenge using four
concentrations of histamine phosphate. The response was registered by counting
sneezes, recording changes in nasal discharge and mucosal swelling and measuring
nasal airway resistance. Sneezing and discharge scores showed that milder non
specific nasal hyper-reactivity was associated with lack of reactivity in skin
prick tests and nasal allergen challenge. No association was observed between
allergy test results and changes in nasal airway resistance during the histamine
provocation. In most patients the symptoms of rhinitis had become milder or
disappeared during the follow-up, but the results of the histamine challenge
showed no relationship with the changes in symptom severity. In patients with
allergic rhinitis, reactivity to histamine is associated with a concomitant
change in skin and nasal mucosal reactivity to allergens.
PMID- 10779190
TI - Evaluation of methods for endoscopic staging of nasal polyposis.
AB - Endoscopy is needed for reliable evaluation of the treatment of nasal polyposis.
In this study, we compared the reproducibility of various score systems for
staging nasal polyposis and the inter-individual variations between
investigators. The mass of the polyps was assessed by five methods, three new
techniques (numbers 1, 2 and 3) and two established ones (numbers 4 and 5). These
were: 1, lateral imaging projecting the extension of the polyps by drawing on a
schematic picture of the lateral wall of each nasal cavity; 2, assessment of
polyp obstruction estimating the proportion of the total nasal cavity volume
occupied by polyps; 3, nasal airway patency--determining the relationship between
the patient's patent airway lumen and an imaginary maximal nasal airway lumen; 4,
a score system with four steps ad modum Lildholdt et al.--determining their
relationship to fixed anatomical landmarks; and 5, a score system with three
steps ad modum Lund and Mackay--determining their relationship to the middle
meatus. High correlations were found between the first and the second assessments
by a given investigator with all five methods used to score nasal polyposis. High
correlations were also shown between the various methods. When three
investigators examined a given patient, there were no significant differences
between the investigators using score systems 1, 3 and 4. However, with score
systems 2 and 5, there was insufficient agreement between the investigators. The
patient's symptom of nasal blockage was not a good indicator of the size of the
polyps, especially as regards small polyps. Two of the best methods tested (1 and
4) were selected for further clinical studies regarding evaluation of the
sensitivity of score systems to detect changes in polyp size during treatment.
PMID- 10779191
TI - Postnatal presence of paraseptal cartilages in humans: a description of
morphology and size.
AB - Paraseptal cartilages (PCs) have been the subject of controversy, in that some
authors believe them to be absent or rarely present, while others have described
them to exist at predictable locations in adult human tissue specimens. This
study seeks to determine the presence or absence of PCs in humans and describe
their morphology and size. Nasal septal tissue from 19 adults and 1 child were
paraffin embedded, coronally sectioned, placed on slides, and stained for
microscopic observation. For all specimens, PCs were identified and lengths were
calculated. Selected PCs were also digitized in order to calculate volume.
Results demonstrated that PCs were present in all 20 tissue specimens and assumed
a common morphology. In each, PCs were found to begin as hyaline cartilage lobes
that extend projections in a superolateral direction as an anteroposterior course
is followed. The projections were found to rotate inferiorly until each PC was
found to assume a position that extended below the nasal septum. Length measures
in adults ranged from 8,725 to 19,000 microm (x = 14,188.9 microm) and volumes
ranged from 7.7 to 24.2 (x = 13.2) x 10(-3) ml. A quantitative comparison to
foetal data from a previous study suggests prenatal and/or postnatal growth of
PCs. Results from this study support the presence of PCs in adult humans as well
as prenatal/postnatal growth of PCs.
PMID- 10779192
TI - Effects of a pressure surround on the regional taste detection threshold for
sodium chloride.
AB - The question as to whether tactile stimulation alters proximal taste function in
humans has never been answered, despite the suggestion of anatomical and
physiological associations between somatosensory and gustatory function in a
number of species. In this study, we established NaCl detection thresholds for a
25 mm2 anterior tongue region on four test occasions in each of 12 men and 12
women. Testing was performed using the Regional Automated Taste Testing System
(RATTS), a device that allows for accurate temporal and spatial presentation of
tastants to the lingual surface. On each test occasion, a different negative
pressure (vacuum suction) was applied around the stimulus presentation field of
the glass stimulation device (i.e. 40, 50, 60 and 70 mmHg). The order of
presentation of the vacua was systematically counterbalanced among subjects
across sessions using 4 x 4 Latin square sequences. Neither the vacua nor their
order of presentation meaningfully altered the taste threshold values, even
though the higher vacua produced persistent discernible discomfort in most
subjects. On average, taste thresholds tended to be marginally lower in women
than in men. These data indicate that static vacuum-induced tactile stimulation
around a discrete anterior taste field has no meaningful influence on NaCl
detection threshold sensitivity.
PMID- 10779193
TI - Dissection plane of the human vocal fold lamina propria and elastin fibre
concentration.
AB - To determine whether a natural plane of dissection occurs in the normal human
vocal fold, semi-blunt instruments (Bouchayer laryngeal dissectors) were used to
dissect the lamina propria. The depth of the plane of dissection was correlated
with the elastin fibre concentration to determine whether the plane occurred at a
predictable point in the elastin concentration as it increased between the
superficial and middle layers. Eight human larynges were dissected using an
operative microscope. The dissection plane consistently occurred between 23-50%
depth into the lamina propria. No consistent correlation was found with the
elastin fibre concentration. The depth of the plane of dissection has an
interesting association with age: dissection planes occurred more superficially
in older specimens.
PMID- 10779194
TI - Biofilm formation on voice prostheses: influence of dairy products in vitro.
AB - Laryngectomized patients use silicone rubber voice prostheses to regain their
speech, however, the lifetime of these devices is limited due to biofilm
formation. Following anecdotal evidence, the influence of various dairy products
on biofilm formation on voice prostheses was studied, using the artificial throat
model. Biofilms were grown on Groningen and Provox2 voice prostheses by
inoculating two artificial throats with the total microflora isolated from an
explanted Groningen voice prosthesis. After 3 days, one throat was perfused three
times daily with 650 ml dairy product; the other was perfused with phosphate
buffered saline, used as a control. After 12 days the microflora on each voice
prosthesis was determined. Perfusion of the artificial throat with buttermilk
three times daily for 9 days reduced the amount of bacteria and yeasts in the
biofilm on Groningen voice prostheses to 3% and 15% of the control, respectively.
These effects were not observed with a pasteurized conservable buttermilk
product. Yakult fermented milk drink, Mona mild yoghurt, Mona vifit yoghurt, semi
skimmed milk and low-fat yoghurt reduced the amount of bacteria by various
degrees, ranging from 12% (Yakult) to 88% (Mona mild) of the control, but these
products did not inhibit, and sometimes even stimulated, yeast growth. A
combination of buttermilk and Yakult did not show a synergistic effect, as
expected. Effects for the Provox2 voice prosthesis were less pronounced. These in
vitro experiments in the artificial throat demonstrated that the formation of the
biofilm on voice prostheses can be lessened by the daily use of certain dairy
products, of which buttermilk had the strongest inhibitory effect, followed by
Yakult.
PMID- 10779195
TI - Proper use of serum antibody titres against Epstein-Barr virus in nasopharyngeal
carcinoma: IgA/virus capsid antigen for diagnosis and EBV-related nuclear antigen
2 for follow-up.
AB - Sera from patients with nasopharyngeal carcinoma (NPC) show high titres of IgA
antibodies to Epstein-Barr viral capsid antigen (IgA/VCA). We reported previously
that the serum titres for Epstein-Barr virus-related nuclear antigen-2 (EBNA2)
correlated with NPC patients' prognosis. To investigate which is better for
diagnosing NPC and predicting patient prognosis, the titration of serum IgA/VCA
or EBNA2, we examined the same serum titres. Sixteen cases of NPC in which serum
EBNA2 antibody titres had been tested, were investigated for the serum IgA/VCA
antibody titres before and after radiation treatment. All NPC cases showed
positive reactions with indirect immunofluorescence staining, and the median
titre was 252. Twelve normal controls, 5 mesopharyngeal carcinoma patients, 4
hypopharyngeal carcinoma patients, 4 laryngeal carcinoma patients and 6 malignant
lymphoma were also examined, but they showed negative or relatively low titres. A
follow-up study revealed that IgA/VCA titres remained mostly stable. These
results indicate a close relationship between IgA/VCA and NPC, however, prognosis
correlated better with EBNA2 titres than with IgA/VCA titres.
PMID- 10779196
TI - Vascular endothelial growth factor expression correlates with p53 mutation and
angiogenesis in squamous cell carcinoma of the head and neck.
AB - Vascular endothelial growth factor (VEGF) has potent angiogenic activity and has
been identified in a wide variety of malignancies, including head and neck
squamous cell carcinoma (HNSCC). The tumour-suppressor gene p53 has been thought
to regulate VEGF. Cryostat sections of 33 head and neck squamous cell carcinomas
(HNSCC) were immunostained for VEGF using a standard streptavidin-biotin complex
procedure. To evaluate angiogenesis, microvascular density was counted by
staining endothelial cells immunohistochemically using anti-vWF monoclonal
antibody. The p53 gene status was analysed using a PCR-SSCP analysis and direct
sequencing. VEGF positive staining was detected in 18 (55%) out of 33 tumours.
VEGF immunoreactivity did not correlate with the main clinicopathological
characteristics of the patients (localization, T-stage, N-status, histological
grading). Statistical analysis gave a clear correlation between the tumour
vascularity and the VEGF protein expression (p = 0.0036). VEGF negative tumours
showed a lower mean number of microvessels per microscopic field (60.3 +/- 15.5)
than VEGF positive tumours (79.6 +/- 22.9). P53 mutations were identified in 12
(36.4%) of 33 tumours. The association of p53 mutations and VEGF expression level
was significant (0.027). The higher microvessel density in VEGF positive tumours
supports the importance of VEGF for tumour angiogenesis in HNSCC. Our results
support the hypothesis of a p53 regulation on the angiogenic process through a
VEGF up-regulation.
PMID- 10779197
TI - Vestibular evoked myogenic potentials in humans.
PMID- 10779198
TI - Epidemiological surveillance of infectious diseases in France.
AB - Epidemiological surveillance, namely the continuous monitoring of diseases and
health determinants in a population, has developed over the past fifteen years,
in the sphere of human health as well as in animal health. All epidemiological
surveillance networks include the following four stages: data collection, data
transmission, data processing and dissemination of information. However, despite
this basic similarity, the very many networks existing in France are extremely
varied in nature. At the national level, the bodies involved in epidemiological
surveillance for infectious animal diseases are the Direction generale de
l'alimentation, the Agence francaise de securite sanitaire des aliments and, to a
lesser degree, the Institut francais de recherche pour l'exploitation de la mer.
In the field, the networks rely on the Direction des services veterinaires,
veterinary practitioners, laboratories in each departement, and livestock
producers' groups (especially animal health protection groups). Some twenty
French networks currently in operation are presented in this article according to
a classification based on published criteria. In the case of human infectious
diseases, epidemiological surveillance is carried out almost entirely by the
Direction generale de la sante and the Directions departementales d'action
sanitaire et sociale, the Institut de veille sanitaire and the various Centres
nationaux de reference (CNRs). Most human infectious diseases are monitored by
one or more of the following broad categories of networks: reporting of
notifiable diseases, the CNRs, the network of sentinel doctors, the network of
hospital laboratories and departments, and medical causes of death. An example
where surveillance is covered by several networks is also presented, namely
surveillance for salmonellosis and Salmonella. Lastly, methods for evaluating
networks are discussed.
PMID- 10779199
TI - Proinflammatory cytokines and viral respiratory disease in pigs.
AB - Swine influenza virus (SIV), porcine respiratory coronavirus (PRCV) and porcine
reproductive and respiratory syndrome virus (PRRSV) are enzootic viruses causing
pulmonary infections in pigs. The first part of this review concentrates on known
clinical and pathogenetic features of these infections. SIV is a primary
respiratory pathogen; PRCV and PRRSV, on the contrary, tend to cause subclinical
infections if uncomplicated but they appear to be important contributors to
multifactorial respiratory diseases. The exact mechanisms whereby these viruses
cause symptoms and pathology, however, remain unresolved. Classical studies of
pathogenesis have revealed different lung cell tropisms and replication kinetics
for each of these viruses and they suggest the involvement of different lung
inflammatory responses or mediators. The proinflammatory cytokines interferon
alpha (IFN-alpha), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL
1) have been shown to play key roles in several respiratory disease conditions.
The biological effects of these cytokines and their involvement in human viral
respiratory disease are discussed in the second part of this review. The third
part summarises studies that were recently undertaken in the authors' laboratory
to investigate the relationship between respiratory disease in pigs and bioactive
lung lavage levels of IFN-alpha, TNF-alpha and IL-1 during single and combined
infections with the above viruses. In single SIV infections, typical signs of
swine "flu" were tightly correlated with an excessive and coordinate production
of the 3 cytokines examined. PRCV or PRRSV infections, in contrast, were
subclinical and did not induce production of all 3 cytokines. Combined infections
with these 2 subclinical respiratory viruses failed to potentiate disease or
cytokine production. After combined inoculation with PRCV followed by bacterial
lipopolysaccharide, both clinical respiratory disease and TNF-alpha/IL-1
production were markedly more severe than those associated with the respective
single inoculations. Taken together, these data are the first to demonstrate that
proinflammatory cytokines can be important mediators of viral respiratory
diseases in pigs.
PMID- 10779200
TI - Clinical response and immunomodulation following experimental challenge of calves
with type 2 noncytopathogenic bovine viral diarrhea virus.
AB - Eight calves between 16 and 18 weeks of age that were seronegative to bovine
viral diarrhea virus (BVDV), bovine leucosis virus and bovine immunodeficiency
like virus were infected (day 0) intranasally with the type 2 noncytopathogenic
Canadian 24515 field isolate of BVDV in order to evaluate the effect of BVDV
infection on certain clinical, hematological and immunological parameters. All
virus-exposed animals developed fever and showed a significant (P < 0.05, 0.01 or
0.001) drop in the number of circulating leucocytes (neutrophils, lymphocytes and
monocytes) by day 3 or 5 post-exposure (PE), which continued to the end of the
experiment at day 12 PE. BVDV was consistently isolated from the peripheral blood
buffy coat cells from day 5 PE, and also from selected tissues (spleen, thymus,
mesenteric and submaxillary lymph nodes, small intestine, lungs and thyroid
gland) that were collected at the time of euthanasia of the animals at day 12 PE.
Diminished significant (P < 0.05) percentages of peripheral blood mononuclear
cells (PBMCs) expressing at their surface either B7 and MHC II molecules were
observed in virus-exposed calves at days 7, 10 and/or 12 PE, when compared to
virus-nonexposed control calves (n = 5). However, no changes in the percentages
of PBMCs expressing either B4 or MHC I molecules were observed throughout the
experiment. Finally, a significant (P < 0.05 or 0.01) enhanced phagocytic
capability of the PBMCs, as analyzed by flow cytometry, was observed in virus
exposed animals at days 3, 5, 7, 10 and 12 PE, when compared to control calves.
These results demonstrated the virulence of the 24515 isolate of BVDV in 4 to 4.5
month-old calves, and suggest that type 2 BVDV infection in calves is associated
with dysregulation of certain immunological functions.
PMID- 10779201
TI - Purification and characterisation of bovine WC1+ gammadelta T lymphocytes from
peripheral blood.
AB - In order to isolate and characterise resting WC1+ gammadelta T cells from cattle,
we developed a protocol for purifying these cells by negative selection from
peripheral blood. The purification method included five steps: separation of
mononuclear cells on lymphoprep, depletion of monocytes by adherence to plasma
coated gelatin, enriching T cells on a nylon wool column, depleting CD2+ T cells
by sheep red blood cells (SRBC), and finally depleting CD4+ and CD8+ T cells by
the magnetic cell sorting technique (MACS). This procedure proved efficient and
reproducible, and the purity of the isolated WC1+ gammadelta T cells was more
than 97% as analysed by flow cytometry (FACS). Cytokines and costimulatory
molecules mRNA expression was assessed by the reverse transcriptase polymerase
chain reaction (RT-PCR) technique in freshly isolated resting WC1+ T cells. We
found that purified uncultured WC1+ T cells express TNF-alpha, CD28, CTLA-4 and
IL-2R alpha mRNA transcripts but do not express those for IL-2, IL-4, IL-6, IL-10
and IFN-gamma. The expression of CD28 and CTLA-4 transcripts on bovine WC1+ T
cells indicates that these genes are evolutionarily conserved.
PMID- 10779202
TI - Bovine respiratory syncytial virus: first serological evidence in Uruguay.
AB - Bovine respiratory syncytial virus (BRSV) is a major cause of respiratory disease
in calves resulting in a substantial economic loss for the cattle industry
worldwide. In order to determine the presence of BRSV in Uruguay, an
immunoenzymatic test was set up, using a recombinant BRSV nucleocapsid (N)
protein as the antigen. The N protein was produced in Sf9 insect cells by a
recombinant baculovirus expressing the N protein. Serum samples collected from
one hundred cattle from four different geographic regions of Uruguay were
analyzed. Antibodies against the N protein of BRSV were detected in 95% of the
serum samples analyzed. These results show for the first time the presence of
BRSV antibodies and suggest a widespread BRSV infection in the cattle population
of Uruguay.
PMID- 10779203
TI - The effect of two levels of dietary protein on resistance and resilience of dairy
goats experimentally infected with Trichostrongylus colubriformis: comparison
between high and low producers.
AB - Numerous studies have examined the interactions between protein nutrition and the
response to nematode parasitism in sheep, but very few in goats. Compared with
other ruminants, goats are less resistant to nematode infection. In addition, in
dairy goats, high producing animals have been shown to be less resistant and less
resilient to infection compared to low producing ones. The objective of the
present study was to examine the consequences of protein supplementation on both
resistance and resilience of dairy goats to nematode trickle infection, taking
into account the initial level of milk production of the animals. During a 14
week period, 40 milking goats received a high protein (HP) diet supplying 130% of
the protein requirements, and 38 goats were fed a intermediate protein (IP) diet
(120% of the protein requirements). In addition, half of each group was given a
weekly trickle infection with Trichostrongylus colubriformis larvae, the other
part of the flock remained non-infected. Faecal egg counts (FEC), eosinophil
counts and pathophysiological data (urea, albumin and inorganic phosphate
concentrations in the serum) were measured twice a month. Milk production data
(milk yield, protein and fat contents) were also recorded every 15 days. The
results showed that FECs were lower (p < 0.05) and eosinophil counts higher (p <
0.05) in the animals receiving the HP diet suggesting that resistance was
enhanced by protein supplementation. Meanwhile, milk parameters (related to
resilience) were not affected by the level of protein in the diet when
considering the whole groups. In contrast, in the high producing goats, the milk
production and milk composition parameters were improved with the HP diet. To
conclude, we have seen that the expression of both resistance and resilience did
not appear when the coverage of the protein requirements was insufficient.
Because the milk production is dependent on the protein supply, we suggest that
there is a competition in the use of the protein between the development of
resistance and the milk production.
PMID- 10779204
TI - Effect of strategic gastrointestinal nematode control on faecal egg count in
traditional West African cattle.
AB - This paper reports on the effect of strategic anthelmintic treatments and other
determinants on faecal egg counts (FEC) of Trichostrongyles in N'Dama cattle of a
west African village. Initially, 527 animals from 13 private N'Dama cattle herds
were monitored in a longitudinal study from October 1989 to December 1994. Each
herd was stratified by age and animals were sequentially allocated to two groups
with similar age distributions. One group received a single anthelmintic
treatment of fenbendazole (7.5 mg/kg BW), in October 1989 (n = 250), whereas the
other group remained untreated (n = 277) throughout the study. In the next rainy
season (June to October), the treated animals were treated twice (in July and
September). The same treatment schedule was used in the subsequent rainy seasons
until December 1994. Biannual anthelmintic treatments decreased the level of FEC
between 31% (late dry season) and 57% (rainy season), when compared to untreated
controls. The highest levels of FEC were found during the rainy season from June
to October. FEC levels decreased until 4 years of age, after which they remained
on a constant low level. The variability of returns to anthelmintic treatments
between herds did not seem to be influenced by FEC at the herd level. The
financial evaluation of anthelmintic interventions cannot be predicted from FEC
and must necessarily rely on the direct monitoring of livestock productivity
parameters.
PMID- 10779205
TI - In vitro inhibitory effect of SR 27417, a potent platelet-activating factor (PAF)
receptor antagonist, on the PAF-induced bovine platelet aggregation.
AB - The in vitro inhibitory effect of SR 27417, an antagonist of the platelet
activating factor (PAF) receptor, on PAF-induced platelet aggregation was studied
in blood collected from seven healthy Friesien calves. Inhibitory effects of SR
27417 were determined at thirteen different concentrations (0.1-400 nM) by using
the dose-response curves of PAF on calf platelet aggregation. In the presence of
SR 27417, the maximal slopes of aggregation (%/min) induced by low and high
concentrations of PAF were significantly different from the control values
obtained without an antagonist at p < or = 0.05 and p < or = 0.01 respectively.
In vitro PAF-induced calf platelet aggregation was dose-dependently inhibited by
SR 27417. The drug inhibited PAF-induced platelet aggregation in a competitive
reversible manner (pA2 = 10.46 +/- 2.36 mol x L(-1)). In conclusion, the results
of our study showed that addition of SR 27417 to bovine platelet in vitro
inhibits PAF-induced platelet aggregation.
PMID- 10779206
TI - From food to nutritional support to specific nutraceuticals: a journey across
time in the treatment of disease.
AB - Hospitalized patients who are unable to eat or cannot eat enough to meet their
metabolic needs are given parenteral or enteral nutritional support. This form of
therapy is now also given to patients at home. Nutritional support is a recent
development, prior to which the value of food was recognized for its medicinal
benefits as nutraceuticals. The value of such "alternative" therapy is now being
rediscovered by many patients who enhance their dietary intake with these
traditional remedies. In Western culture, conventional medicine until recently
has largely rejected the use of such "alternative" therapeutic intervention.
Based on an increasing database, though, insight has been gained concerning the
scientific validity of many previously termed established nutraceuticals. We
focus here on the effects of honey, green tea, ginseng, and vitamin
supplementation on the immune system. Honey has proven antimicrobial activity.
Green tea enhances humoral and cell-mediated immunity while decreasing the risk
of certain cancers and the risk of cardiovascular disease. Ginseng enhances
production of macrophages, B and T cells, natural killer cells, and colony
forming activity of bone marrow. Vitamin supplementation is associated with
increased antibody titer response to both hepatitis B and tetanus vaccines as a
result of macrophage and T cell stimulation. Because of these findings,
nutraceuticals are becoming more widely accepted as an adjunct to conventional
therapies for enhancing general well-being.
PMID- 10779207
TI - Nutritional treatment with branched-chain amino acids in advanced liver
cirrhosis.
AB - During the last 20 years there has been much interest in nutritional treatment
for patients with advanced cirrhosis. Most studies have measured the potential
benefit of nutritional supplements of dietary proteins, generic protein
hydrolysates, or specific branched-chain amino acid (BCAA)-enriched formulas in
regard to nutritional parameters and hepatic encephalopathy. The issue is not
definitively settled; data are conflicting and meta-analyses have failed to
produce unequivocal results. A consensus review, recently produced under the
auspices of the European Society for Parenteral and Enteral Nutrition, concluded
that: (1) patients with cirrhosis tend to be hypermetabolic, and a higher-than
normal supply of dietary proteins is needed to achieve nitrogen balance; (2) most
patients tolerate a normal or even increased dietary protein intake, without risk
of hepatic encephalopathy; (3) a modified eating pattern, based on several meals
and a late evening snack, is useful; (4) in severely malnourished patients, amino
acid supplements may be considered to provide the necessary amount of proteins to
meet protein requirements; (5) in a few patients intolerant to the required
protein intake, BCAA supplements may be considered to provide the necessary
nitrogen intake without detrimental effects on the mental state, perhaps even
improving it. Future studies are needed to quantify the advantage of nutritional
support with amino acids or BCAA supplements on overall well-being,
complications, and ultimately survival with a long-lasting disease where self
perceived health-related quality of life is a major outcome.
PMID- 10779208
TI - Nutritional pharmacotherapy of chronic liver disease: from support of liver
failure to prevention of liver cancer.
AB - Many patients with liver cirrhosis are in a state of protein and energy
malnutrition and require careful nutritional support. Our research has revealed
that approximately 30% of the patients have protein-energy malnutrition, 40%
protein malnutrition, and 10% energy malnutrition; 20% are in a normal
nutritional state. Supplementation with branched-chain amino acids alleviates
chronic liver failure, improves the protein nutritional state, and subsequently
prolongs survival. In contrast, therapeutic modalities for energy malnutrition
have not yet been fully elucidated and await further studies. Improved survival
of the cirrhotic patients essentially brings a higher incidence of hepatocellular
carcinoma (HCC). A synthetic analogue of vitamin A (acyclic retinoid or 4,5
dehydrogeranyl geranoic acid) prevents at least the development of second primary
tumors after curative treatment of preceding HCC. The mechanism of this cancer
chemo-prevention is clonal deletion of premalignant and latent malignant cells by
the retinoid. We describe our clinical experiences with these two nutritional
pharmacotherapies of chronic liver diseases and review their basic mechanisms.
PMID- 10779209
TI - Nutrition and Crohn's disease.
PMID- 10779210
TI - Therapeutic efficacy of elemental enteral alimentation in Crohn's disease.
PMID- 10779211
TI - Role of arginine in immunonutrition.
AB - Arginine plays an important role in many physiologic and biologic processes
beyond its role as a protein-incorporated amino acid. Dietary supplementation of
arginine can enhance wound healing, regulate endocrine activity and potentiate
immune activity. Under normal unstressed conditions the arginine requirement of
adult humans is fulfilled by endogenous sources, however this is compromised
during times of stress, especially in critical illness. These finding have led to
use of arginine supplementation as part of an immune-enhancing dietary regimen to
help combat the immune suppression seen in such patients. Though the results from
studies examining the use of this type of immunonutrition in critically ill
patients are far from definitive, they are promising that this mode of therapy
may be of some advantage. A better understanding of the in vivo biology of
arginine and its metabolism is necessary to truly define a benefit from arginine
supplementation.
PMID- 10779212
TI - N-3 polyunsaturated fatty acids in pharmaconutrition and immunonutrition.
PMID- 10779213
TI - Effect of administration of nucleosides and nucleotides on protein turnover and
the hypoxic myocardium.
AB - Nucleotides and nucleosides have effects on improving energy metabolism and
enhancing immune function. Under a surgical stress, requirement of nucleotides
are increased as well as nitrogen. A well-balanced nucleoside solution (OG-VI)
was developed for parenteral administration and its effect was examined in
animals. The OG-VI solution contained 3.11% of nucleosides which was composed of
inosine, guanosine monophosphate, cytidine, uridine and thymidine of 4:4:4:3:1 in
molar ratio. The whole body protein turnover increased significantly in rats
received total parenteral nutrition (TPN) with OG-VI after 70% hepatectomy and
enhanced the fractional protein synthesis rates of the muscle and liver. Also
myocardial contractility (%segment shortening, %SS) in dogs after occlusion of
left anterior descending artery (LAD) was recovered to 70% after reperfusion in
the OG-VI group. The creatine phosphate (PCr) / inorganic phosphate (Pi) was
maintained the baseline level and did not decrease after hypoxia in the OG-VI
group while PCr/ Pi was decreased after hypoxia in normal rat. These data
suggested that the nucleoside-nucleotide (OG-VI) improved nitrogen metabolism and
might stimulate synthesis of high-energy phosphate in recovery after severe
surgical stress.
PMID- 10779214
TI - Helicobacter pylori-negative peptic ulcers: frequency and implications for
management.
AB - Most patients with peptic ulcers are infected with Helicobacter pylori, but the
infection may not be responsible for the ulcer. It is increasingly recognized
that different causes of ulcers coexist in a given patient, confounding
determination of the exact cause of the ulcer. For example, in infected patients
with ulcers who also are using nonsteroidal anti-inflammatory drugs (NSAIDs), it
is not possible to establish the ulcer's cause. Moreover, recent studies in the
United States in infected patients with duodenal ulcers who were treated with
various regimens to prove their efficacy in eradicating H. pylori and preventing
ulcer recurrence found that approximately 20% of patients suffered an ulcer
recurrence despite successful H. pylori eradication. The infection clearly did
not cause their ulcers but was originally thought to have done so. Thus, as many
as one-fifth of patients with ulcers may have the cause falsely attributed to H.
pylori infection. When this number is added to that of ulcer patients who are H.
pylori-negative upon original presentation--at least 20% in other recent U.S.
studies--it is evident that the proportion of non-H. pylori ulcer patients is
larger than originally believed. This proportion is likely to increase with the
declining incidence of H. pylori infection. Other causes of ulcers include the
use of aspirin and NSAIDs (which may be surreptitious), hypersecretory states,
Crohn's disease, and patients with "idiopathic" ulcers. Patients with
"idiopathic" ulcers are characterized by postprandial hypersecretion of acid and
hypergastrinemia with accelerated gastric emptying. H. pylori ulcers may be
difficult to manage because antisecretory drugs are less effective in inhibiting
gastric acidity in the absence of H. pylori infection.
PMID- 10779215
TI - Helicobacter pylori-negative peptic ulcer in Japan: which contributes most to
peptic ulcer development, Helicobacter pylori, NSAIDS or stress?
AB - Of 302 patients with peptic ulcer, 11 (3.6%) proved negative for Helicobacter
pylori: 9 with gastric ulcer (GU) and 2 with duodenal ulcer (DU). Among these 11
H. pylori-negative patients with ulcers, two with GU were using non-steroidal
anti-inflammatory drugs (NSAIDs) and one with GU was using a corticosteroid. The
Hanshin-Awaji earthquake induced life-event stress that not only triggered but
exacerbated GU, particularly in the elderly, resulting in a higher GU/DU ratio
than the corresponding period of the previous year (3.07 vs. 1.88) in the
devastated area. Furthermore, the seroprevalence of the infection and the odds
ratio from the case-control study were similar to or even higher than that
reported previously in patients with GUs unrelated to the earthquake. H. pylori
and the use of NSAIDs are the major independent risk factors for peptic ulcers,
although, H. pylori infection plays some role in the development of peptic ulcers
under stressful conditions.
PMID- 10779216
TI - Non-Helicobacter pylori ulcer disease in rheumatoid arthritis patients receiving
long-term NSAID therapy.
AB - Helicobacter pylori and nonsteroidal antiinflammatory drugs (NSAIDs) are
considered the major causes of peptic ulcer. If ulcers are not attributable to H.
pylori, most are thought to be attributable to NSAIDs. We have previously
reported that rheumatoid arthritis (RA) patients taking NSAIDs long term (NSAIDs
group) are more likely to develop gastric ulcers, which commonly occur in the
gastric antrum. In addition, the morphology of gastric ulcers in the NSAIDs group
differs from that in the non-NSAIDs group (control group), in whom NSAIDs are not
involved in the occurrence of gastric ulcers. In this study, we compared gastric
ulcers in the NSAIDs group with those in the control group in terms of H. pylori
infection. The positive rate of H. pylori in gastric ulcers was significantly
lower in the NSAIDs group than in control group (53.6% vs 91.5%). At the ulcer
site they were seen significantly less often in the antrum than in either the
angle or body of the stomach (35% vs 100%) in the NSAIDs group. On the other
hand, the H. pylori-positive rate for ulcers in the antrum did not differ
significantly from that in the angle and body of the stomach (81.8% vs 93.8%) in
the control group. These findings suggest that H. pylori plays little role in
antral ulcers in those taking NSAIDs.
PMID- 10779217
TI - Helicobacter pylori: criminal or innocent bystander?
AB - Most patients with peptic ulcer disease are infected with Helicobacter pylori.
However, the infection may not be always causative for the disease. The
prevalence of H. pylori infection is about 50% in general. Therefore, half of the
patients with peptic ulcer could be infected with this microorganism just by
chance. In such cases, H. pylori may do nothing for the ulcer, although it causes
chronic active gastritis. This could be the reason for the existence of both H.
pylori-positive nonrecurring ulcers and ulcers that recur even after cure of H.
pylori infection. H. pylori-positive non-recurring ulcers should be included in
non-H. pylori ulcer disease in addition to H. pylori-negative ulcers. NSAIDs are
the major cause of H. pylori-negative ulcers, especially H. pylori-negative
gastric ulcers. However, more than 10% of ulcers recurred even after cure of H.
pylori infection in nonusers of NSAIDs in a 7-year follow-up study. In the same
study, 46% of ulcers did not recur in patients in whom eradication of H. pylori
failed. There are few (<5%) H. pylori-negative ulcers; about 10% of ulcers recur
after cure of H. pylori infection, and about 40% of H. pylori-positive ulcers do
not recur. These are all non-H. pylori ulcers, and they represent 30% of all
ulcers, which is the general prevalence rate for nonulcer subjects. Therefore, H.
pylori may be an innocent bystander in approximately one third of all ulcer
patients.
PMID- 10779218
TI - Helicobacter pylori-negative ulcer disease.
AB - The proportion of ulcer patients without evidence of Helicobacter pylori
infection varies considerably in different parts of the world, which may be
explained by the different prevalence of H. pylori infection in the background
population. In any ulcer patient with an H. pylori-negative test, it is important
to consider that the test may be falsely negative due to treatment with
antibiotics, bismuth preparations, or potent acid inhibitory therapy. The
commonest cause of true H. pylori-negative ulcers is usage of nonsteroidal anti
inflammatory drugs, so patients should be carefully questioned about such
therapy. Rarer causes of H. pylori-negative duodenal ulcers include
gastroduodenal Crohn's disease and Zollinger-Ellison syndrome. About 50% of H.
pylori-negative duodenal ulcer patients have no apparent explanation for the
ulcer disease. A proportion of these patients have increased gastric acid
secretion and increased duodenal acid load, which is likely to be of pathogenic
significance. H. pylori-negative ulcers are more difficult to control with
antisecretory drugs.
PMID- 10779219
TI - Reg protein: a possible mediator of gastrin-induced mucosal cell growth.
PMID- 10779220
TI - Molecular mechanisms for the growth factor action of gastrin.
PMID- 10779221
TI - Epithelial-mesenchymal interaction in gastric mucosal restoration.
AB - In this review article we discuss the role of growth factors in gastric ulcer
healing using an in vitro wound repair model with gastric epithelial and
mesenchymal cells. Several growth factors accelerate gastric epithelial and
mesenchymal wound healing in vitro with acceleration of cell migration and
proliferation. Epidermal growth factor, transforming growth factor-alpha
(TGFalpha), hepatocyte growth factor, and insulin accelerate predominantly
gastric epithelial wound healing; and TGFbeta and basic fibroblast growth factor
predominantly accelerate gastric mesenchymal wound healing. Platelet-derived
growth factor-betabeta and insulin-like growth factor-1 (IGF-1) accelerate both
significantly. Among these growth factors, IGF-1 produced from fibroblasts plays
a key role in the gastric epithelial-mesenchymal interaction during the process
of gastric wound healing.
PMID- 10779222
TI - Mechanisms of regulatory peptide action in the gastrointestinal tract: trefoil
peptides.
AB - The trefoil peptide family is comprised of three small peptides (designated pS2,
SP, and ITF) exhibiting a unique motif of three intrachain loops formed by
disulfide bonds. These highly protease-resistant peptides are secreted onto the
mucosal surface by goblet cells or their equivalents. Most importantly, these
factors protect epithelium from injury and promote repair through restitution
after injury has occurred. Targeted deletion of the gene encoding ITF results in
exquisite sensitivity to colonic injury by standard agents (e.g., dextran sodium
sulfate) due to an inability to repair the epithelium. Studies have led to
insight into the intracellular responses to trefoil peptides, including ras
dependent MAP kinase activation and activation of epidermal growth factor
receptor. Among other effects, activation of these pathways is associated with
redistribution of E-cadherin from the cell surface to intracellular domains,
where it is complexed with catenins, and phosphorylation of akt, inactivating
this kinase associated with apoptosis. In addition, trefoil peptides appear to
block both p53 dependent and p53 independent apoptosis through pathways
associated with activation of EGFR and P13 kinase. These observations suggest
that trefoil peptides elicit a coordinated cellular response enabling cell
migration without triggering the programmed cell death response usually
precipitated by cell detachment from a stationary anchored state.
PMID- 10779223
TI - Effects of loss-of-function and gain-of-function mutations of c-kit on the
gastrointestinal tract.
AB - Protooncogene c-kit encodes a receptor tyrosine kinase, KIT. Interstitial cells
of Cajal (ICCs) that are important for the autonomous movement of the
gastrointestinal tract essentially require the normal function of the KIT for
their development. Therefore, germline loss-of-function mutations of the c-kit
gene cause deficiency of ICCs that results in disturbed gastrointestinal
movement. On the other hand, somatic gain-of-function mutations of the c-kit gene
induce gastrointestinal stromal tumors (GIST) that are considered to originate
from ICCs. Moreover, germline gain-of-function mutations of the c-kit gene are a
cause of familial development of multiple GISTs.
PMID- 10779224
TI - Regulation of collagen alpha1(I) expression in hepatic stellate cells.
AB - The regulation of collagen alpha1(I) expression in hepatic stellate cells (HSCs)
occurs in a complex fashion that is just beginning to be determined. The presence
of regulatory sequences in both the 5' and 3' regions of the mRNA appear to be
critical to its regulation in HSCs and are involved in the increased expression
of collagen in activated HSCs. The 3' UTR contains a C-rich site that binds
alphaCP, a known RNA-binding protein that is responsible for the increased
stability of the mRNA in activated HSCs. Given that alphaCP is present in both
activated and quiescent HSCs, there must be a mechanism for modifying alpha(CP to
bind to the RNA in activated but not quiescent HSCs. The 5' region contains an
evolutionary conserved stem-loop region that encompasses the translation
initiation codon. This stem-loop can bind protein(s) in activated HSCs in an RNA
cap-dependent manner. Such binding, together with the binding of alphaCP to the
3' UTR, can facilitate translation of collagen alpha1(I) mRNA, resulting in
increased mRNA steady-state levels and collagen synthesis. A role of alphaCP in
activating translation initiation has also been demonstrated. These two
mechanisms work together to upregulate collagen alpha1(I) production in activated
but not quiescent HSCs.
PMID- 10779225
TI - Epidemiology of gastric cancer: an evaluation of available evidence.
AB - Despite a dramatic reduction in incidence and mortality rates, gastric cancer
(GC) is still one of the most common malignant neoplasias worldwide. Surgical and
medical treatments have not substantially improved during the last decades, and
large-scale early diagnosis programs have proven feasible in only one high-risk
country, Japan. A large number of studies have indicated that salted, smoked,
pickled, and preserved foods (rich in salt, nitrite, and preformed N-nitroso
compounds) are associated with an increased risk of GC. In contrast, strong
evidence has been provided that high consumption of fresh fruit and raw
vegetables and a high intake of antioxidants are associated with a reduced risk
of GC. Domestic refrigeration and reduced salt consumption are considered to play
a role in explaining the decreasing temporal trend and the geographical patterns
of GC. Familial factors have been suspected to play a role in GC susceptibility,
and recently germ line mutations in the E-cadherin gene were identified in a few
families. Evidence of a positive association between Helicobacter pylori
infection and GC risk has been provided by most prospective studies that overall
suggest a two- to threefold increase in risk. Randomized intervention studies on
H. pylori eradication and its effects on GC predisposing conditions (atrophic
gastritis and intestinal metaplasia) are in progress and represent a priority for
epidemiological research in view of the potential preventive applications.
Overall, it is evident that several factors (including diet, individual
susceptibility and H. pylori infection) interact in a complex multifactorial
process, leading over a long period of time to GC.
PMID- 10779226
TI - Helicobacter pylori infection is the primary cause of gastric cancer.
AB - Helicobacter pylori causes gastric cancer in human and in experimental animals.
The link between gastritis and H. pylori is causal. Differences in the incidence
of gastric cancer in populations with similar high prevalence of H. pylori
infection can be related to the differences in the age of acquisition of chronic
atrophic gastritis, which in turn is related to an interaction between
environmental factors, especially diet, and H. pylori infection. The low odds
ratios reported in epidemiology studies evaluating the relation between gastric
cancer and H. pylori infection reflect the high overall prevalence of H. pylori
in the population and do not accurately reflect the strength of the association.
It is time to stop doing serologic studies to confirm the association of gastric
cancer with H. pylori and instead expend our efforts on eliminating the infection
and investigating the mechanism(s) and interactions.
PMID- 10779227
TI - Helicobacter pylori gastritis of the gastric carcinoma phenotype: is histology
capable of identifying high-risk gastritis?
AB - Several studies have shown that Helicobacter pylori infection implies an
increased risk for developing gastric carcinoma. However, it has to be considered
that only a few among those infected with H. pylori develop gastric cancer. It is
therefore desirable to identify risk indicators of H. pylori gastritis in the
presence of which gastric carcinoma is most likely to occur. In our view, the
risk indicators intestinal metaplasia and atrophy, frequently cited in the
literature, are not suitable, as they are focal changes whose detection at the
routine diagnostic workup may be confounded by sampling error and because early
carcinoma (in particular of the diffuse type) is often not associated with
intestinal metaplasia or atrophy. For this reason we investigated the diffuse
gastritis parameters "grade of gastritis" and "activity of gastritis" for their
suitability as risk indicators. We found that H. pylori gastritis, particularly
in the corpus, is significantly more pronounced in gastric carcinoma patients or
individuals with a family history of gastric cancer than in matched controls.
Hence, a simple comparison of the grade of gastritis and activity of gastritis in
the antrum and corpus might help identify patients with H. pylori gastritis with
an increased cancer risk. Currently. we are testing this hypothesis in an ongoing
gastric cancer prevention study in Germany, Austria, and Czechia.
PMID- 10779228
TI - International comparability of the pathological diagnosis for early cancer of the
digestive tract: Munich meeting.
AB - Large differences have been found between Western and Japanese pathologists'
diagnosis of adenoma/dysplasia versus early carcinoma for gastric, esophageal.
and colorectal epithelial neoplastic lesions. In this study we examined whether
differences in experience in gastrointestinal pathology can to some extent
explain these differences in diagnostic practice. Three Japanese, one British,
and two German pathologists with much experience and one North American
pathologist with less experience in routine diagnostic work reviewed 52
microscopic slides: 16 gastric, 24 esophageal, and 12 colorectal biopsy and
resection specimens obtained from patients with lesions ranging from early
carcinoma to adenoma, dysplasia, and regenerative epithelium. The extent of
agreement between the diagnoses of the four individual Western pathologists and
the most common Japanese diagnoses was assessed by kappa statistics. For the 16
gastric lesions, a diagnosis of suspected or definite carcinoma was made by the
Japanese pathologists in 69%-75% of the slides, by three experienced Western
pathologists in 56%-63% (high kappa values: 0.61, 0.64, 0.65), and by the less
experienced Western pathologist in only 31% of the slides (low kappa value:
0.10). For the 24 specimens of esophageal squamous lesions, carcinoma in situ and
suspected or definite carcinoma were diagnosed by the Japanese in 96%-100% and by
the Western pathologists in 63%-88% of the slides (low kappa values: 0.17, 0.25,
0.25, 0.27). For the 12 colorectal lesions, the Japanese diagnosed suspected or
definite carcinoma in 58%-83%, whereas all Western pathologists followed the
World Health Organization definition of colorectal carcinoma and diagnosed
suspected or definite carcinoma in only 0-42% of the slides (kappa values: 0.04,
0.10,0.12, 0.49). In conclusion, there were few differences in diagnoses between
experienced Western and Japanese pathologists for gastric lesions but
considerable differences for esophageal and colorectal lesions. The differences
in the diagnosis of adenoma/dysplasia versus early carcinoma between Western and
Japanese pathologists found in previous studies may in large part be attributable
to differences in experience with regard to gastric neoplasia and to differences
in interpretation and nomenclature with regard to esophageal and colorectal
neoplasia.
PMID- 10779229
TI - Genetic and epigenetic alterations in multistep carcinogenesis of the stomach.
AB - An accumulation of multiple genetic and epigenetic alterations of oncogenes,
tumor suppressor genes, DNA repair genes, cell cycle regulators, cell adhesion
molecules, and the growth factor/receptor system is involved in the course of
multistep conversion of normal epithelial cells to clinical gastric cancer. Some
of them differ depending on the histological type, well-differentiated
(intestinal) and poorly differentiated (diffuse) types, suggesting the presence
of two distinct genetic pathways. Genetic instability, chromosomal instability
(telomere reduction), and immortality (activation of telomerase and expression of
telomerase reverse transcriptase: TERT) participate in the initial step of
stomach carcinogenesis. Because TERT protein expression precedes the telomerase
activities in precancerous lesions, TERT expression may be a prerequisite for
telomerase activation. The cyclin E gene is amplified in 15%-20% of gastric
cancer. Reduced expression of a cyclin-dependent kinase (CDK) inhibitor, p27Kip1,
is frequently found in gastric cancer associated with high grade malignancy. E2F
1, an important downstream target of cyclins/CDKs, is overexpressed in about 40%
of gastric carcinomas, whereas gene amplification of E2F-1 rarely occurs. Loss of
heterozygosity (LOH) of p73, the p53-related new tumor suppressor gene,
preferentially occurs in well-differentiated adenocarcinomas of foveolar type
expressing pS2, a gastric-specific trefoil factor, indicating the importance of
p73 LOH in the genesis.
PMID- 10779230
TI - What is reasonable treatment for gastric adenocarcinoma?
AB - From its pattern of metastasis and recurrence, gastric carcinoma can be
recognized as a slow-growing malignancy whose local control is still the most
important part of treatment. With application of asymptomatic population
screening and awareness of the high risk of this disease among the general
population in Japan, many early lesions and even noninvasive cancers have been
detected. For such tumors as noninvasive ductal carcinoma of the breast, local
resection has become the popular treatment, and endoscopic mucosal resection is
used for many early lesions. For advanced cancers, extended lymph node dissection
has been applied in Japan and some other countries. The treatment results have
improved remarkably in these countries. There are several reasonable explanations
for the effectiveness of extended nodal dissection, but it is still controversial
because of reported excessive postoperative morbidity and mortality and lack of
proof in a randomized controlled trial. The Dutch Gastric Cancer Trial could not
prove the benefit of extended lymph node dissection, although some data suggest
its benefit over limited dissection. Further clinical trials seem necessary to
evaluate its value in Western countries, but such trials should be carried out in
limited specialist centers to exclude technical bias of two types of operation.
PMID- 10779231
TI - Detailed colonoscopy for detecting early superficial carcinoma: recent
developments.
AB - Early superficial colorectal carcinoma (CRC) has been commonly detected by
routine colonoscopic examination in Japan. A series of 769 early CRCs and 4821
adenomas were diagnosed by colonoscopy at Hiroshima University Medical Hospital
between 1991 and 1998. Of early CRCs, macroscopically superficial early CRCs
accounted for 209 lesions (28%). Among 5590 lesions of adenomas and carcinomas,
depressed-type lesions showed a significantly higher malignant potential for
cancerous and submucosal invasion than elevated lesions (polypoid, IIa-type
lesions, and G-LST). As one of the quantitative examinations for early CRC, pit
pattern observed by magnifying video-colonoscopy was useful. We performed
magnifying observations for 265 lesions of colorectal neoplasias using Kudo's pit
pattern classification for 2 years. Depressed-type lesions characterized the Ills
and V pit patterns, and elevated lesions characterized the III(L) pit pattern.
The incidence of cancer was significantly higher in lesions with IIIs and V pit
patterns. Furthermore, the V(N) pit pattern was considered a significant
indicator of submucosal invasion. These results indicated that superficial early
CRC could be considered to constitute about one-third of all early CRCs. Of them,
the depressed-type lesions showed a significantly higher malignant potential than
elevated lesions. Pit pattern observation by magnifying videocolonoscopy is
useful for predicting the histology/invasion depth of early CRC.
PMID- 10779232
TI - How does surgical technique affect outcomes in rectal cancer?
PMID- 10779233
TI - Significance and limit of lymph node dissection: efficacy of combined modalities.
PMID- 10779234
TI - Recent advances in colorectal chemotherapy: oral fluorinated pyrimidines,
oxaliplatin and irinotecan.
PMID- 10779235
TI - New drugs for colorectal cancer based on Japanese experience.
PMID- 10779237
TI - Contraceptive use in Canada: 1984-1995.
AB - CONTEXT: In every country, contraceptive behavior has important implications for
fertility and the prevalence of sexually transmitted diseases (STDs). There has
been relatively little attention to contraceptive practices in Canada, however,
particularly how patterns of method use may have changed. METHODS: Data on
contraceptive use were collected from 5,315 women in the 1984 Canadian Fertility
Survey, and from 3,220 women and 3,449 men in the 1995 General Social Survey.
RESULTS: Among Canadian women aged 15-49, current contraceptive use declined from
69% to 60% between 1984 and 1995. Pill use dropped from 19% to 17%, and IUD use
declined from 6% to 3%. However, during the same period, condom use increased
from 6% to 10%; tubal ligation declined from 24% to 17%, while vasectomy
increased. In addition, the proportion of women sterilized for reasons other than
contraception rose between 1984 and 1995. Men were less likely to rely on
sterilization than were women (31 % vs. 40%). Men reported higher levels of
condom use (22%), but lower levels of pill use among their partners (9%), than
did women (10% and 17%, respectively). CONCLUSIONS: Contraceptive behavior in
Canada is unique: The decline in contraceptive use over the last decade has left
Canada's overall contraceptive prevalence among the lowest in the industrialized
world, and the rate of sterilization among the highest These changes in
contraceptive behavior complicate efforts to plan for social and health needs,
particularly policy decisions focusing on reducing infections with STDs.
PMID- 10779236
TI - Psychosocial factors and the timing of prenatal care among women in New Jersey's
HealthStart program.
AB - CONTEXT: Helping high-risk pregnant women obtain prenatal care early is the main
policy goal of most U.S. publicly funded programs aimed at reducing the incidence
of low birth weight and infant mortality It is therefore crucial to understand
the factors that influence when women initiate prenatal care. METHODS: The
effects of psychosocial and demographic risk factors on the timing of entry into
prenatal care were estimated using data on roughly 90,000 Medicaid recipients who
participated in New Jersey's HealthStart prenatal care program. RESULTS: Overall,
37% of women began prenatal care in the first trimester. Multivariate logistic
regression indicated that women who lived in poor housing conditions and those
who smoked, drank or used hard drugs had a reduced likelihood of entering care
early (odds ratios, 0.8-0.9), while those who had clinical depression or who
experienced domestic violence or abuse had elevated odds of early entry (1.1
1.2). The risk factor with the greatest impact on the timing of prenatal care was
the wantedness of the pregnancy; women whose pregnancy was unwanted had
dramatically reduced odds of entering care early (0.4). Separate analyses of
women of varying racial and ethnic backgrounds demonstrated the differential
effects of risk factors, the importance of including ethnicity with race and the
universal impact of wantedness across racial and ethnic groups. CONCLUSIONS:
Entry into prenatal care for at-risk women is affected by factors from multiple
domains. It is important for prenatal programs to recognize the complexity of the
issue as well as the barriers that different subgroups of women face.
PMID- 10779238
TI - Are there unmet family planning needs in Europe?
AB - CONTEXT: The measurement of unmet need for family planning--the discrepancy
between individuals' sexual and contraceptive behavior and their stated fertility
preferences--has generally focused on developing countries. There has so far been
little effort to measure how low unmet family planning needs can go in more
developed countries, where contraceptive practice is supposedly (nearly) perfect.
METHODS: Data were taken from Fertility and Family Surveys (FFS) conducted in
recent years in selected member states of the United Nations Economic Commission
for Europe, and minimum and maximum estimates of unmet need were calculated for
10 countries with the requisite data. RESULTS: The proportion of individuals with
an unmet need for family planning (i.e., who have a current unwanted pregnancy or
who are fecund, are sexually active, want no more births but are not using
contraceptives) is as low as 3% in two European countries and below 10% in most.
However, levels of unmet need in countries with economies in transition (13% in
Latvia and Lithuania and 23% in Bulgaria) surpass some of the lowest levels
observed for developing countries. Considerable within-country variations are
seen. For instance, unmet need is more prominent among men than among women in
seven of the nine countries for which there are data. Moreover, unmet need
increases with family size and with age, suggesting an unmet need for limiting
rather than for spacing births. In all of the countries except Hungary, unmet
need is higher among those in marital unions than among those in less formal
relationships. Level of education is another important dimension of unmet need,
with less-educated respondents having the highest level of unmet need in nine of
the 10 countries. Multivariate analyses confirm most of these results. Moreover,
there is a clear association between unmet need and abortion ratios: Where levels
of unmet need are high, the number of abortions per 100 live births is also
relatively high. CONCLUSIONS: Data on unmet need, supplemented with information
on induced abortion and related issues, could provide countries in Europe with
useful inputs for formulating and implementing responsive reproductive health
policies and programs.
PMID- 10779240
TI - The pill at 40--a new look at a familiar method. Whose pill is it, anyway?
PMID- 10779241
TI - The pill at 40--a new look at a familiar method. The pill and men's involvement
in contraception.
PMID- 10779239
TI - Relationship dynamics, ethnicity and condom use among low-income women.
AB - CONTEXT: Women's protection against HIV and sexually transmitted diseases (STDs)
depends upon their ability to negotiate safer sex. It is important to know how
cultural norms and gender roles, which vary by ethnicity, may either constrain or
encourage negotiation of condom use. METHODS: Questionnaires were completed by
393 low-income non-Hispanic black, Hispanic and non-Hispanic white women who were
sexually active and attending family planning and STD clinics and other public
health and social service centers in Miami in 1994 and 1995. Multivariate logit
techniques were used to identify ethnic differences in relationship dynamics and
to determine couple- and individual-level factors associated with consistent use,
occasional use or nonuse of condoms. RESULTS: Black and Hispanic women reported
higher levels of consistent condom use (15-17%) than did white women (4%). Nearly
all black and white women (90-95%) said that they were extremely or somewhat
comfortable talking about condoms with their partner, whereas 76% of Hispanic
women did so. A larger proportion of Hispanic women (55%) reported joint
contraceptive decision-making than did black women (26%) or white women (31%).
Among women who reported that their partner made contraceptive decisions, 28%
used condoms consistently or occasionally, compared with 24% among women who made
the decision themselves. When the couple made the decision jointly, 41% of them
were condom users. Hispanic women scored the lowest on a scale of condom-related
self-efficacy, yet also reported the highest levels of confidence in their condom
negotiating skills. Multivariate analysis indicated that, compared with white
women, black and Hispanic women were more likely to be consistent condom users
than nonusers (odds ratios, 10.2 and 18.9, respectively). Women who shared
financial decision-making with their partner were almost 80% less likely to be a
consistent condom user, and women who did not participate in financial decisions
were more than 90% less likely to do so, than were women who made monetary
decisions independently. CONCLUSIONS: HIV prevention and intervention programs
should emphasize birth control discussion between partners and the development of
condom-related self-efficacy and negotiation skills, and these programs also
should customize prevention messages according to ethnicity and social context.
PMID- 10779242
TI - The pill at 40--a new look at a familiar method. Mothers, daughters and the pill.
PMID- 10779243
TI - The pill at 40--a new look at a familiar method. Black women and the pill.
PMID- 10779245
TI - Evidence-based preventive care: a timely matter.
PMID- 10779244
TI - The pill at 40--a new look at a familiar method. Will the pill become obsolete in
this century?
PMID- 10779246
TI - Tympanocentesis: to tap or not to tap.
PMID- 10779247
TI - Nightmares and disorders of dreaming.
AB - Dreams occur during all stages of sleep. Nightmares are common. They can be
associated with poor sleep and diminished daytime performance. Frequent
nightmares are not related to underlying psychopathology in most children and in
some "creative" adults. However, recurrent nightmares are the most defining
symptom of post-traumatic stress disorder and may be associated with other
psychiatric illnesses. Night terrors are arousal disorders that occur most often
in children and usually occur early in the sleep period. Patients with rapid-eye
movement behavior disorder often present with nocturnal injury resulting from the
acting out of dreams. Dream disorders may respond to medication, but behavioral
treatment approaches have shown excellent results, particularly in patients with
post-traumatic stress disorder and recurrent nightmares.
PMID- 10779248
TI - Acute otitis media: Part I. Improving diagnostic accuracy.
AB - Acute otitis media is overdiagnosed. Symptoms are neither sensitive nor specific
for the diagnosis of otitis media; fever and ear pain are present in only one
half of patients. Undue reliance on one feature--redness of the tympanic membrane
-and failure to assess tympanic membrane mobility with pneumatic otoscopy
contribute to inaccurate diagnoses. Adequate visualization of the tympanic
membrane is often impaired by low light output from old otoscope bulbs and
blockage of the ear canal by cerumen. Distinguishing acute otitis media from
otitis media with effusion is clinically important because antibiotics are seldom
indicated for the latter condition. A key differentiating feature is the position
of the tympanic membrane: it is usually bulging in acute otitis media and in a
neutral position or a retracted position in otitis media with effusion.
Tympanometry and acoustic reflectometry can be useful adjunctive tools to confirm
the presence of fluid in the middle ear. Selective use of tympanocentesis in
cases of refractory or recurrent middle ear disease can help guide appropriate
therapy and avoid unnecessary medical or surgical interventions.
PMID- 10779249
TI - Management of giant cell arteritis and polymyalgia rheumatica.
AB - Giant cell arteritis and polymyalgia rheumatica are closely related disorders
that affect persons more than 50 years of age and cause substantial morbidity.
Patients with giant cell arteritis typically have a localized headache,
nonspecific systemic symptoms, temporal artery tenderness and a high erythrocyte
sedimentation rate (ESR). The diagnosis is confirmed by characteristic pathologic
findings on temporal artery biopsy. Patients with polymyalgia rheumatica usually
have similar nonspecific systemic symptoms, proximal muscle pain and stiffness,
and an elevated ESR. The diagnosis is based on the clinical findings. Both
disorders are treated with corticosteroids: high dosages for giant cell arteritis
(prednisone in a dosage of 40 to 60 mg per day) and lower dosages for polymyalgia
rheumatica (prednisone in a dosage of 10 to 20 mg per day). Symptom relief in
response to treatment is rapid and reinforces the diagnosis. After normalization
of the ESR, the corticosteroid is tapered, with the patient monitored closely for
symptom recurrence. Most patients require corticosteroid therapy for two to three
years and experience one or more treatment complications.
PMID- 10779250
TI - Acute renal failure.
AB - Acute renal failure occurs in 5 percent of hospitalized patients. Etiologically,
this common condition can be categorized as prerenal, intrinsic or postrenal.
Most patients have prerenal acute renal failure or acute tubular necrosis (a type
of intrinsic acute renal failure that is usually caused by ischemia or toxins).
Using a systematic approach, physicians can determine the cause of acute renal
failure in most patients. This approach includes a thorough history and physical
examination, blood tests, urine studies and a renal ultrasound examination. In
certain situations, such as when a patient has glomerular disease, microvascular
disease or obstructive disease, rapid diagnosis and treatment are necessary to
prevent permanent renal damage. By maintaining euvolemia, recognizing patients
who are at increased risk and minimizing exposure to nephrotoxins, physicians can
decrease the incidence of acute renal failure. Once acute renal failure develops,
supportive therapy is critical to maintain fluid and electrolyte balances,
minimize nitrogenous waste production and sustain nutrition. Death is most often
caused by infection or cardiorespiratory complications.
PMID- 10779251
TI - Promoting and supporting breast-feeding.
AB - The family physician can significantly influence a mother's decision to breast
feed. Prenatal support, hospital management and subsequent pediatric and maternal
visits are all-important components of breast-feeding promotion. Prenatal
encouragement increases breast-feeding rates and identifies potential problem
areas. Hospital practices should focus on rooming-in, early and frequent breast
feeding, skilled support and avoidance of artificial nipples, pacifiers and
formula. Infant follow-up should be two to four days postdischarge, with liberal
use of referral and support groups, including lactation consultants and peer
counselors.
PMID- 10779252
TI - Hip pain in athletes.
AB - Hip pain in athletes involves a wide differential diagnosis. Adolescents and
young adults are at particular risk for various apophyseal and epiphyseal
injuries due to lack of ossification of these cartilaginous growth plates. Older
athletes are more likely to present with tendinitis in these areas because their
growth plates have closed. Several bursae in the hip area are prone to
inflammation. The trochanteric bursa is the most commonly injured, and the lesion
is easily identified by palpation of the area. Iliotibial band syndrome presents
with similar lateral hip pain and may be identified by provocative testing
(Ober's test). A methodical physical examination that specifically tests the
various muscle groups that move the hip joint can help determine a more specific
diagnosis for the often vague complaint of hip pain. A number of hip conditions
are more prevalent in athletes of certain ages. Transient synovitis is a common
diagnosis in the very young, Legg-Calve-Perthes disease causes bony disruption of
the femoral head in prepubescents, and slipped capital femoral epiphysis is seen
most commonly in obese adolescent males. Femoral neck stress fractures are seen
in adult athletes, especially those involved in endurance sports, and can
progress to necrosis of the femoral head if not found early. Older athletes may
be limited by degenerative joint disease but nonetheless should be encouraged to
stay active.
PMID- 10779253
TI - Addiction: Part I. Benzodiazepines--side effects, abuse risk and alternatives.
AB - Benzodiazepines are widely prescribed for a variety of conditions, particularly
anxiety and insomnia. They are relatively safe and, with overdose, rarely result
in death. However, used chronically, benzodiazepines can be addicting. These
agents are often taken in combination with other drugs of abuse by patients with
addiction disorders. In such patients, alternatives to benzodiazepines may be
preferable and may include antidepressants, anticonvulsants, buspirone,
antihypertensive agents and the newer neuroleptic medications. Caution must be
used when prescribing benzodiazepines to patients with a current or remote
history of substance abuse.
PMID- 10779254
TI - Drug therapy for obesity.
AB - Obesity is a common health problem in the United States, and effective treatment
is challenging. Obesity is associated with an increased mortality rate and risk
factors such as hypertension, hyperlipidemia and diabetes mellitus. Numerous
treatments are available for obesity. Behavioral therapy, surgery and
pharmacologic treatment have been used with varying degrees of success. Older
anorectic agents have significant side effects and limited benefit, and some have
even been withdrawn from the U.S. market because of a possible association with
cardiovascular complications. The safety of newer agents must be extensively
evaluated before widespread use is recommended. Therefore, behavioral therapy,
including regular exercise and the development of healthy eating habits,
continues to be the best treatment for long-term weight loss.
PMID- 10779255
TI - Recognition of common childhood malignancies.
AB - Although cancer has an annual incidence of only about 150 new cases per 1 million
U.S. children, it is the second leading cause of childhood deaths. Early
detection and prompt therapy have the potential to reduce mortality. Leukemias,
lymphomas and central nervous system tumors account for more than one half of new
cancer cases in children. Early in the disease, leukemia may cause nonspecific
symptoms similar to those of a viral infection. Leukemia should be suspected if
persistent vague symptoms are accompanied by evidence of abnormal bleeding, bone
pain, lymphadenopathy or hepatosplenomegaly. The presenting symptoms of a brain
tumor may include elevated intracranial pressure, nerve abnormalities and
seizures. A spinal tumor often presents with signs and symptoms of spinal cord
compression. In children, lymphoma may present as one or more painless masses,
often in the neck, accompanied by signs and symptoms resulting from local
compression, as well as signs and symptoms of systemic disturbances, such as
fever and weight loss. A neuroblastoma may arise from sympathetic nervous tissue
anywhere in the body, but this tumor most often develops in the abdomen. The
presentation depends on the local effects of the solid tumor and any metastases.
An abdominal mass in a child may also be due to Wilms' tumor. This neoplasm may
present with renal signs and symptoms, such as hypertension, hematuria and
abdominal pain. A tumor of the musculoskeletal system is often first detected
when trauma appears to cause pain and dysfunction out of proportion to the
injury. Primary care physicians should be alert for possible presenting signs and
symptoms of childhood malignancy, particularly in patients with Down syndrome or
other congenital and familial conditions associated with an increased risk of
cancer.
PMID- 10779256
TI - Falls in the elderly.
AB - Falls are the leading cause of injury-related visits to emergency departments in
the United States and the primary etiology of accidental deaths in persons over
the age of 65 years. The mortality rate for falls increases dramatically with age
in both sexes and in all racial and ethnic groups, with falls accounting for 70
percent of accidental deaths in persons 75 years of age and older. Falls can be
markers of poor health and declining function, and they are often associated with
significant morbidity. More than 90 percent of hip fractures occur as a result of
falls, with most of these fractures occurring in persons over 70 years of age.
One third of community-dwelling elderly persons and 60 percent of nursing home
residents fall each year. Risk factors for falls in the elderly include
increasing age, medication use, cognitive impairment and sensory deficits.
Outpatient evaluation of a patient who has fallen includes a focused history with
an emphasis on medications, a directed physical examination and simple tests of
postural control and overall physical function. Treatment is directed at the
underlying cause of the fall and can return the patient to baseline function.
PMID- 10779257
TI - Just a scar?
PMID- 10779258
TI - A potentially violent patient?
PMID- 10779259
TI - Adult immunization--pneumococcal vaccine.
PMID- 10779260
TI - ACIP recommendations for the prevention of hepatitis A through immunization.
Advisory Committee on Immunization Practices.
PMID- 10779261
TI - The Antiretroviral Pregnancy Registry Interim Report.
PMID- 10779262
TI - Management of essential infantile esotropia with botulinum toxin A: review and
recommendations.
PMID- 10779263
TI - The feasibility of introducing a visual screening test for children during
vaccination campaigns.
AB - PURPOSE: A visual screening test for children was prepared for the use of
paramedics during vaccination campaigns. This test was used in a vaccination
campaign in Taquaritinga, Sao Paulo, Brazil. METHODS: The campaign was carried
out by two paramedics trained by ophthalmologists. The first 130 children
vaccinated whose families showed interest in participating in the visual
screening program were chosen. The program consisted of demographic information
and eight questions, a visual screening test for children >4 years, and an
external eye examination. After studying the data collected, the paramedic
decided if the child needed a more thorough ophthalmologic examination. RESULTS:
Of the 4505 children vaccinated, 130 children participated in the screening test.
One (76.9%) hundred of the 130 children were reexamined by ophthalmologists. Of
these, 38 (29.2%) were initially considered to have visual disorders.
Ophthalmologic disorders were confirmed in 22 (57.9%) children; of these, 3 were
already under ophthalmologic care. The paramedics correctly screened a total of
77 (77%) children. CONCLUSION: Visual screening during vaccination campaigns is
simple and rapid, and provides the opportunity to identify children with visual
disorders during the critical stage of visual development without the need of
ophthalmologists.
PMID- 10779264
TI - Abnormal function of the parvocellular visual system in anisometropic amblyopia.
AB - PURPOSE: To study the function of the parvocellular (P) and the magnocellular (M)
visual systems with steady-state visual evoked potentials (VEPs) in anisometropic
amblyopes. METHODS: A matrix of isolated checks was superimposed on a steady
background with different check sizes and temporal frequencies to form specific
stimuli to preferentially activate the P or the M visual system. The amplitude of
the VEP fundamental frequency was analyzed at the electrode Oz of 5 anisometropic
amblyopes and 22 normal subjects. The normal subjects were tested at two visual
acuity (VA) levels, 20/20 and 20/40, modified by lenses, to match with the VA
levels of the fellow eyes and the amblyopic eyes of the amblyopes, respectively.
RESULTS: No significant amplitude difference was found between the dominant eyes
and nondominant eyes of the normal subjects for either P or M stimuli at both
20/20 and 20/40 VA levels (P>.05). No significant amplitude difference was found
between the fellow eyes of the amblyopes and the dominant eyes of normals for
either P or M stimuli at 20/20 VA level (P>.05). A significant amplitude
difference was found between the amblyopic eyes and the nondominant eyes of the
normals for P stimuli (P<.05) but not for M stimuli (P>.05) at 20/40 VA level.
CONCLUSIONS: The amplitude of the VEP fundamental frequency was selectively
reduced for P stimuli in anisometropic amblyopic eyes. This clinical
electrophysiologic finding confirms that only the function of the P visual system
is abnormal in anisometropic amblyopic eyes.
PMID- 10779265
TI - Relationship between serum inositol concentration and development of retinopathy
of prematurity: a prospective study.
AB - PURPOSE: To examine the relationship between the intake of sugar inositol, serum
inositol levels, and ROP in three groups of low birthweight infants receiving
feedings containing various concentrations of inositol. METHODS: Infants with a
birthweight <1500 g, with severe lung disease, were eligible for the study when
they began enteral feedings. Infant formulas contained three different inositol
concentrations: 2500, 710, and 242 micromol/L. Serum inositol concentrations were
averaged over specific time intervals. A logistic regression model was used to
investigate the confounding effect of duration of mechanical ventilation and
oxygen therapy, birthweight, Apgar score, and serum inositol concentration on
development of ROP. RESULTS: Infants receiving high inositol formula and with
higher serum inositol concentrations at birth and after 30 days had a
statistically significant lower incidence of severe ROP than those receiving the
lower inositol formula and with lower serum concentrations (P<.05). The effective
serum inositol concentration (EC90) associated with lesser disease was >215
micromol/L. By logistic regression, the odds of developing severe ROP were
greater among infants with low serum inositol concentration (odds ratio=4.7, 95%
confidence interval 0.90-24.8, P=.017). CONCLUSION: Inositol supplementation may
help prevent the most severe form of ROP.
PMID- 10779266
TI - Incidence and survival characteristics of retinoblastoma in Singapore from 1968
1995.
AB - PURPOSE: To describe the incidence and survival of 69 Singapore residents with
retinoblastoma in all Singapore hospitals from 1968-1995. METHODS: Data of all
Singapore residents diagnosed with retinoblastoma from 1968-1995 were collected
by the Singapore Cancer Registry based on notifications from physicians,
pathology records, hospital discharge records, and death certificates. The
medical records of 46 patients were traced, and information on laterality of
tumor, spread of tumor, mode of treatment, and family history of retinoblastoma
was obtained. Time trends and survival characteristics of the cohort were
described. RESULTS: The incidence rate of retinoblastoma was 2.4 per 1 million
for children <9 years and 11.1 per 1 million for children <5 years. The incidence
of retinoblastoma has been almost uniform over time from 1968-1995, except for an
apparent increase in 1988-1992. The 3-year survival rate for retinoblastoma was
83%. Survival rates were higher in children <2 years because children who present
at a younger age may have tumors diagnosed at earlier stages of the disease.
There was no difference in survival rates for sex, race, laterality, family
history of retinoblastoma, treatment, or year of diagnosis. CONCLUSION:
Retinoblastoma is the most common eye cancer in children that may cause blindness
or death. The incidence rates of retinoblastoma in Singapore have remained fairly
stable over 28 years, and the survival rate is higher in younger children. This
study will be helpful in monitoring future disease patterns in Asian populations.
PMID- 10779268
TI - Nasolacrimal duct obstruction.
PMID- 10779267
TI - Evaluation of hemodynamic changes in the ophthalmic artery with color Doppler
ultrasonography after strabismus surgery.
AB - PURPOSE: To investigate the blood flow changes in ophthalmic artery with color
Doppler ultrasonography after strabismus surgery. METHODS: Twenty eyes of 19
patients who underwent recession or resection surgery on two horizontal rectus
muscles in 1 eye were examined using color Doppler ultrasonography preoperatively
and 1 week and 1 month postoperatively. Measurements from both eyes of 16 age-
and sex-matched normal subjects served as control data. The systolic maximum
velocity, mean velocity, end-diastolic velocity, pulsatility index, and
resistance index of the ophthalmic artery were determined. The Mann-Whitney U
test was performed for comparison of the control and study group preoperatively
for any hemodynamic parameter. Statistical comparison of the preoperative and
postoperative measures in the study group was performed with Friedman's two-way
analysis of variance. RESULTS: No difference (P>.05) was observed preoperatively
between the study and control groups for any hemodynamic parameter in the
ophthalmic artery. Although the ophthalmic artery showed a slight increase in
systolic maximum velocity 1 month postoperatively, there were no statistically
significant differences (P>.05) in velocities or resistance in the ophthalmic
artery at any interval. CONCLUSION: Two horizontal rectus muscle operations in a
previously unoperated eye do not cause significant hemodynamic changes in the
ophthalmic artery. However, further studies are needed to obtain more information
about the effect of multiple vertical rectus muscle operations on the blood flow
parameters of the ophthalmic artery.
PMID- 10779269
TI - 10-year-old boy with Duane syndrome OS.
PMID- 10779270
TI - Cataract as an additional sign in CHARGE syndrome.
PMID- 10779271
TI - Retinoblastoma in a patient with Lowe's syndrome.
PMID- 10779272
TI - Traumatic vitreous hemorrhage from a persistent hyaloid artery.
PMID- 10779273
TI - Atypical chorioretinitis as an early presentation of subacute sclerosing
panencephalitis.
PMID- 10779274
TI - Kawasaki disease presenting as orbital cellulitis.
PMID- 10779275
TI - The effect of gender on the prevalence of atopy and asthma.
PMID- 10779276
TI - Bronchial hyperresponsiveness and its relationship to asthma in childhood.
PMID- 10779277
TI - Comparison of mechanisms of IL-3 induced histamine release and IL-3 priming
effect on human basophils.
AB - We have investigated the mechanisms by which interleukin-3 (IL-3) induces
histamine release and primes basophils for increased histamine release in
response to anti-IgE- and N-formyl-methionyl-leucyl-phenylalanine (fMLP). The
responsiveness of basophils from atopic donors was variable, only 5/11 subjects
showing release of > 10%, to IL-3 in the range 0.1-100 ng/ml. IL-3-induced
histamine release required both extracellular Ca2+ and cell membrane IgE, removal
of membrane IgE by lactate stripping or desensitization of basophils by
incubation with anti-IgE in a Ca2+-free medium blocking IL-3-induced histamine
release. IL-3 also primed basophils for histamine release by anti-IgE and fMLP in
the same concentration range as it evoked histamine release. When IL-3 and either
anti-IgE or fMLP were combined, the result was additive or supra-additive
depending on the basophil donor. Unlike IL-3-evoked histamine release, IL-3
priming of basophils for fMLP-induced histamine release was shown to be
independent of the presence of both cell surface IgE and of extracellular
calcium. The protein kinase C (PKC) inhibitor, staurosporine (10 nM), inhibited
anti-IgE induced histamine release, but neither IL-3 induced histamine release
nor IL-3 priming of IgE- and fMLP-induced histamine release. Pertussis toxin (1.0
microg/ml) inhibited fMLP-induced histamine release but not anti-IgE-induced
histamine release, IL-3-evoked histamine release or IL-3 priming. These results
indicate that IL-3 modulates mediator release from human basophils by two
mechanisms; a direct release of histamine which involves cell surface IgE and the
influx of extracellular calcium but which is unlikely to proceed by the same
mechanism as cross-linkage of IgE, and a priming effect which is independent of
IgE and extracellular Ca2+ and which enhances the secretory effects of a wide
range of unrelated secretagogues.
PMID- 10779278
TI - Annual variations in grass pollen seasons in London 1961-1990: trends and
forecast models.
AB - The record of daily average grass pollen concentrations monitored at St Mary's
Hospital, Paddington, London, U.K. since 1961 is the longest duration pollen data
set in Europe. Analysis of the results identifies the trends and characteristics
of grass pollen seasons over three decades. During this time seasonal allergic
rhinitis has increased significantly in Britain. The annual start dates, length
of season and severity are examined in relation to the main meteorological
variables of cumulated temperatures above 5.5 degrees C and precipitation
measured at one site within London and two in the surrounding rural areas. Land
use changes are also considered. Significant decreases have taken place in both
the duration and severity of the seasons, particularly between the 1960s and the
early 1970s but also through the last 20 yr. This is largely a result of a
decrease in pollen abundance in the region. The decline in pollen counts has
slowed in recent years due to the increase in flowering grasses caused by the set
aside policy and by uncut verges. Grass pollen seasons have tended to start later
over the last two decades, despite an increase in the cumulated temperature
profiles during late winter and spring. Empirical models have been developed
using multiple regressions to incorporate meteorological and pollen data for the
last 20 yr in order to forecast the start dates, duration and severity of the
grass pollen seasons. These models were applied successfully using the data for
1991 and 1992. Predictions of the main characteristics of the pollen seasons can
be obtained relatively early in the year through the use of these models by
employing the monthly weather forecasts in conjunction with long-term average
weather profiles.
PMID- 10779279
TI - Identification of basophils by immunohistochemistry in the airways of post-mortem
cases of fatal asthma.
AB - There is increasing evidence for the role of basophils in the pathogenesis of
bronchial asthma. To examine the presence of basophils in the airways of patients
with fatal asthma by immunohistochemistry, we stained lung tissues from four post
mortem cases who had died from severe asthmatic attacks and four controls with a
monoclonal antibody raised against tryptase (AA-1) and anti-IgE. Mast cells and
basophils were identified in the bronchioles as AA-1- and anti-IgE-positive
cells, and anti-IgE-positive cells, respectively. Airway mast cells were found
beneath the basement membrane, near blood vessels in the submucosa, and adjacent
to the submucosal glands, and scattered throughout the muscle bundles. There was
a significant increase of mast cells in the asthma group compared with the
control group (203.5+/-84.6/mm2, mean+/-s.d. vs 37.7+/-8.7/mm2, P<0.05, n=4). In
contrast, basophils were observed in the airway lumen, in the bronchial
epithelium and in the submucosa. The number of basophils in the bronchioles was
81.8+/-55.5/mm2 (n = 4); however, basophils were not found at all in the airways
of the control group. Although eosinophils, B lymphocytes and macrophages bear
low affinity IgE receptors and could react with anti-IgE, the location of these
cells in the close sections did not correspond closely with basophils. The
presence of basophils in lung tissues obtained from fatal asthma patients
supports the view that basophils play a role in the pathogenesis of bronchial
asthma.
PMID- 10779280
TI - Expression of CD35 (CR1) and CD11b (CR3) on circulating neutrophils and
eosinophils from allergic asthmatic children.
AB - Complement receptors on neutrophils and eosinophils play a role in activation and
adhesion. During asthmatic reactions these receptors have been found elevated on
circulating granulocytes. In the present study we compared the expression of CD35
(complement receptor type 1) and CD11b (complement receptor type 3) on
neutrophils and eosinophils from asthmatic and non-asthmatic children. This was
done in whole blood samples using depolarized light scattering for the
discrimination of neutrophils and eosinophils. The non-stimulated expression as
well as the upregulated expression of receptors by the chemotactic peptide N
formylmethionyl-leucyl-phenyl-alanine (fMLP) were studied. The results showed
that without prior stimulation only the expression of CD35 on neutrophils was
significantly elevated in children with asthma (P<0.05). After up-regulation with
fMLP, the CD11b expression on neutrophils (P<0.005, fMLP: 0.002 microM) and
eosinophils (P<0.05, fMLP: 0.02 microM) was significantly higher in asthmatic
children than in the controls. These results indicate that the inducible
expression of CD11b on neutrophils and eosinophils from allergic asthmatic
children is primed in vivo.
PMID- 10779281
TI - Molecular cloning of a house dust mite allergen with common antibody binding
specificities with multiple components in mite extracts.
AB - Plaque radio-immuno assay has been used to isolate an IgE-binding clone from a
lambda gt11 library of Dermatophagoides pteronyssinus cDNA. The clone HD6
contained DNA encoding a 215 residue protein which contained a predicted 17 amino
acid residue leader sequence, no cysteines and a single N-glycosylation site. The
198 residue mature protein would have a predicted MW of 22,177 D. No homologues
were found in searches of the data banks. Sera from 14/38 allergic children
reacted strongly with the polypeptide produced by the clone (37%). Skin tests
showed reactivity in 16/30 (53%) allergic patients and 0/10 of controls. Affinity
purification of rabbit antibodies with the clone showed that antibodies to the
polypeptide had specificities to multiple products in mite extracts corresponding
to components of Mr 29, 27 and 24 K by Western blotting. Absorption studies of
IgE in allergic serum indicated further entities at 13 and 11.5 kD. It is
proposed to name this allergen Der p VII.
PMID- 10779282
TI - Atopy in childhood. I. Gender and allergen related risks for development of hay
fever and asthma.
AB - Reasons for the gender differences in prevalence rates for asthma remain unclear.
We have examined the relationships between allergen skin-test reactions and
diagnoses of hay fever and asthma in New Zealand boys and girls examined at the
age of 13 years. Information on current and past wheezing, diagnosed asthma, and
hay fever was obtained for 662 subjects (341 boys) of a birth cohort followed
longitudinally to the age of 13 years, using a physician-administered
questionnaire. Atopic status was determined by skin-prick tests to 11 common
allergens. The proportion of 13-year-old boys with current asthma was 1.6 times
higher and of ever-diagnosed asthma 1.4 times higher than in girls, but the
prevalence of recurrent wheeze (> or = three episodes per year) not diagnosed as
asthma, or of hay fever, was not significantly different between the sexes. The
prevalence of diagnosed asthma increased with increasing numbers of positive skin
tests, but hay fever without asthma was little affected above one positive skin
test. Boys had a greater prevalence of any positive skin-test (50.1% vs 37.1%),
two or more positive tests (29.3% vs 21.8%), and responses to house dust mite
(34.0% vs 23.1%) and cat (14.7% vs 11.2%). Gender differences for asthma became
insignificant when adjusted for skin-test responsiveness to house dust mite
and/or cat. The proportion of children with diagnosed asthma increased with
increasing size of weals to house dust mite and cat dander. Gender differences in
allergen sensitivities partly explain the gender differences in diagnosed asthma
in children. In both sexes, risk of asthma was primarily associated with
sensitization to indoor allergens (house dust mite and cat), and was related to
the magnitude of the skin-test response, while the risk of hay fever was
primarily associated with grass pollen sensitivity.
PMID- 10779283
TI - Atopy in childhood. II. Relationship to airway responsiveness, hay fever and
asthma.
AB - While airway hyperresponsiveness is usually associated with a diagnosis of asthma
or symptoms of wheezing, some individuals with rhinitis show airway
hyperresponsiveness as do some with no symptoms whatsoever. We have studied the
correlations between symptoms, airway hyperresponsiveness and atopy as determined
by skin-prick tests in a cohort of New Zealand children. A total of 662 members
of a birth cohort were studied at age 13 years using a respiratory questionnaire,
skin-prick tests to 11 common allergens, and an abbreviated validated
methacholine challenge test to determine airway responsiveness. Airway
hyperresponsiveness (methacholine PC20 FEV1 < or = 8 mg/ml) was strongly
correlated with reported asthma and current wheezing (P<0.0001) and also with
atopy, especially to house dust mite and cat (P<0.0001). As weal size for both
house dust mite and cat increased, so did the proportion of children with airway
hyperresponsiveness. All children with diagnosed asthma and airway
hyperresponsiveness were atopic. Skin-test reactions to house dust mite and cat
were strongly correlated with any degree of measurable airway responsiveness
(PC20 FEV1 < or = 25 mg/ml) in children with rhinitis (P<0.00001), and remained
significantly correlated even in children without current asthma, without asthma
ever and without rhinitis (P<0.001). Atopy is a major determinant of airway
hyperresponsiveness in children, not only in those with reported histories of
asthma and wheezing, but also in the absence of any history suggesting asthma and
rhinitis.
PMID- 10779284
TI - Atopy in childhood. III. Relationship with pulmonary function and airway
responsiveness.
AB - The relationship between atopy and pulmonary function in children, and how these
relate directly or indirectly to airway hyperresponsiveness, is uncertain. We
have examined these relationships in a sample of 13-year-old children. A
questionnaire on respiratory symptoms, skin-prick tests to 11 common allergens,
spirometry and an abbreviated methacholine challenge test were completed by 662
members (341 boys) of a birth cohort of New Zealand children followed
longitudinally to age 13. There was a significant relationship between the
presence and degree of atopy, and baseline pulmonary function. Low FEV1/VC ratios
were associated with a greater likelihood of airway responsiveness, not only in
subjects with diagnosed asthma, but also in the full cohort and in the sub-group
of 426 children who denied asthma or current wheeze. The relationships between
baseline FEV1/VC and airway responsiveness were stronger in atopic than in non
atopic children, with the strongest relationships in children sensitive to house
dust mite and/or cat dander. In the presence of atopy, progressively lower levels
of lung function were strongly associated with a higher prevalence of airway
responsiveness (P<0.001). In non-atopic subjects, only those with the most
impaired lung function (FEV1/VC < 75%) showed any substantive prevalence of
airway responsiveness. The relationship between the degree of atopy and the
FEV1/VC ratio, although significant in univariate analysis, became completely non
significant after accounting for airway responsiveness. In 13-year-old children,
atopy, especially to house dust mite and cat dander, was correlated with
pulmonary function expressed as FEV1/VC ratio. Airway responsiveness likewise
correlated with impaired baseline lung function. The apparent relationship of
lung function to atopy occurred primarily as a result of the relationship between
atopy and airway responsiveness. Atopy and impaired lung function were additive
factors predicting airway responsiveness.
PMID- 10779285
TI - Allergic and inflammatory eye disease--report on the BSACI (Ophthalmic section)
satellite meeting held at the International Conference Centre, Birmingham, 1993.
PMID- 10779286
TI - Food intolerance and the scientific trap.
PMID- 10779287
TI - Asthma and altitude.
PMID- 10779288
TI - Testing for inhalant allergy in asthma.
PMID- 10779289
TI - Histamine-free diet: treatment of choice for histamine-induced food intolerance
and supporting treatment for chronic headaches.
AB - Histamine-induced food intolerance is not IgE-mediated. Skin-prick testing and
specific IgE to food allergens are typically negative. Food rich in histamine or
red wine may cause allergy-like symptoms such as sneezing, flush, skin itching,
diarrhoea and even shortness of breath. The suspected reason is a diminished
histamine degradation based on a deficiency of diamine oxidase. As diamine
oxidase cannot be supplemented, a histamine-free diet was implemented to reduce
histamine intake. Forty-five patients with a history of suffering from
intolerance to food or wine (n = 17) and chronic headache (n = 28) were put on
the diet over months to years. Fish, cheese, hard cured sausages, pickled cabbage
and alcoholic beverages had to be avoided. Complaint intensity and drug-use per
week prior to and 4 weeks after a histamine-free diet were compared. After 4
weeks on the diet 33/45 patients improved considerably (P < 0.01), eight of them
had total remission. In 12/45 patients, however, no changes in symptoms were
observed. Symptoms of food or wine intolerance significantly decreased (P < 0.02;
treatment of choice), headaches decreased in frequency (P < 0.001), duration and
intensity. After eating histamine-rich food symptoms were reproducible and could
be eliminated by anti-histamines in most patients. These data indicate the role
of histamine in food and wine intolerance and that histamine-rich food causes a
worsening of symptoms in patients suffering from chronic headaches. Results
obtained support the hypothesis of a deficiency of diamine oxidase in patients
with intolerance to food or wine.
PMID- 10779290
TI - Effect of beclomethasone dipropionate nasal aerosol on serum markers of bone
metabolism in children with seasonal allergic rhinitis.
AB - Thirty-nine children with grass pollen hay fever were randomly treated with nasal
inhaled beclomethasone dipropionate (BDP) 200 or 400 microg/day or sodium
cromoglycate (SCG) 30 mg/day for 2 months during the pollen season. Serum
osteocalcin (OC), parathyroid hormone (PTH), total alkaline phosphatase (AP),
bone alkaline phosphatase (BAP) and type I collagen telopeptide (ICTP) were
measured immediately before, 1 and 2 months after treatment and 1 week after
stopping the therapy. No significant changes in OC, PTH, AP, BAP and ICTP serum
level occurred within each group. Minor and probably clinically insignificant
between group differences were occasionally found. Our study shows that BDP nasal
spray has no significant effect on common markers of bone metabolism.
PMID- 10779291
TI - Spontaneous histamine release in whole blood in patients before and after 4
months of specific immunotherapy.
AB - Spontaneous histamine release (SHR) in whole blood was assessed before and after
4 months of specific immunotherapy (SIT) for allergic rhinoconjunctivitis in 32
patients. Spontaneous histamine release was significantly enhanced (P < 0.05) in
patients prior to immunotherapy compared with 20 controls. Spontaneous histamine
release decreased significantly in patients after 4 months of specific
immunotherapy (P < 0.04) and almost reached the same values as spontaneous
histamine release in controls. Clinical success of treatment after 4 months was
seen in 15 patients (improvement > or =50%), 10 of whom showed a significant
decrease in spontaneous histamine release. Decrease of spontaneous histamine
release after 4 months indicates the efficacy of specific immunotherapy already
at an early stage of treatment. Assessment of spontaneous histamine release
appears to be a useful and easily performable method for monitoring success of
treatment of patients during specific immunotherapy.
PMID- 10779292
TI - Pistachio nut hypersensitivity: identification of pistachio nut allergens.
AB - Type I hypersensitivity to pistachio nut antigens was demonstrated in three
patients by means of immediate skin-test reactivity, specific IgE determination
by a fluoroimmunoassay (CAP), CAP-inhibition and leucocyte histamine release.
Sensitization to other dried fruits and pollens was observed in the patients. The
CAP-inhibition studies revealed significant crossreactivity between pistachio and
cashew nut belonging to the Anacardiaceae family, and between pistachio nut and
other dried fruits belonging to taxonomically unrelated botanical families. No
relevant crossallergenicity was observed between pistachio nut and Lolium and
Olea pollens. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS
PAGE) of a pistachio nut extract followed by immunoblotting analysis identified
four IgE-binding bands with molecular weights of 34, 41, 52 and 60 kD.
PMID- 10779293
TI - Effects of the platelet activating factor antagonists BN 52021 and BN 50730 on
antigen-induced bronchial hyperresponsiveness and eosinophil infiltration in lung
from sensitized guinea-pigs.
AB - The involvement of platelet activating factor (PAF) in antigen-induced bronchial
hyperresponsiveness was investigated by the use of the PAF antagonists BN 52021
and BN 50730, in a guinea-pig model where sensitization and challenge were
performed by aerosol. Male Hartley guinea-pigs were sensitized by two aerosol
exposures at 48 hr intervals to a 0.9% NaCl solution (saline) containing 2 mg/ml
ovalbumin for 30 min. Fifteen to 20 days later, guinea-pigs were challenged by
exposure to five successive aerosols of increasing concentrations of ovalbumin
(OA) or respectively, 10 microg/ml, 100 microg/ml, 1 mg/ml, 5 mg/ml and 10 mg/ml
for 15 min each, or saline alone. Three to four hr and 18-24 hr after the aerosol
challenge the guinea-pigs were prepared for recording of bronchopulmonary
response and aerosol administrations were then generated with an ultrasonic
nebulizer. The bronchopulmonary responses induced by successive 1-min aerosol
bursts of acetylcholine (ACh) was assessed. As compared with saline-challenged
guinea-pigs, an enhanced bronchopulmonary response to aerosol administration of
cumulative doses of ACh was observed, 3-4 hr and 18-24 hr post-ovalbumin
challenge. When the sensitized guinea-pigs were pretreated 1 hr before ovalbumin
exposure with BN 52021 or BN 50730 (25 mg/kg, per os), a significant inhibition
of the increase in the bronchopulmonary response to ACh was observed, both at 3-4
hr and 18-24 hr. Furthermore, when guinea-pigs were treated 3-4 hr after the
ovalbumin exposure with BN 52021 or BN 50730, a significant inhibition of the
hyperresponsiveness to ACh was recorded at 18-24 hr. A marked accumulation of
eosinophils in the peribronchial regions was observed on histological
preparations of lung specimens collected 4 hr or 24 hr after ovalbumin exposure.
Pretreatment of the guinea-pigs by BN 50730 or BN 52021 did not modify the
eosinophil accumulation in the peribronchial area. No significant difference in
the number of eosinophils collected in the bronchoalveolar lavage fluid is
observed, 24 hr post-ovalbumin challenge, under the pretreatment with BN 52021 or
BN 50730. Pretreatment of guinea-pigs by BN 50730 or BN 52021 significantly
reduced the PAF-induced (100 microg/ml) increase in eosinophil number in the
peribronchial area. By contrast, they did not inhibit the eosinophilia induced by
aerosol administration of LTB4 (5 microg/ml). These results suggest that the
bronchial hyperresponsiveness observed in this study is associated with
eosinophil accumulation in the lung. The potent inhibition of the bronchial
hyperresponsiveness by the two unrelated antagonists of PAF suggests that the
lipid mediator is involved in its triggering and duration, but not in the
eosinophil infiltration.
PMID- 10779294
TI - Three cases of occupational asthma and rhinitis caused by garlic.
PMID- 10779295
TI - Abnormalities in histamine pharmacodynamics in chronic urticaria.
AB - Histamine plays a key role in the pathogenesis of chronic urticaria (CU). The
authors of this paper have studied the effects of ingested histamine in 25
patients with CU. A 120 mg dose of histamine, well-tolerated in the healthy
subject, was instillated into the duodenum. Concomitantly, plasma histamine (H)
levels and plasma and urinary methylhistamine (MH) levels were measured.
Intraduodenal administration of histamine was responsible for the development of
an attack of urticaria in 64% of patients, while control subjects were
asymptomatic. Plasma histamine levels were significantly higher after digestive
histamine challenge (DHC) in patients with CU compared with controls. An abnormal
increase in plasma histamine was observed in 72% of them. Plasma MH exhibited the
same kinetic behaviour with a usually delayed time-pattern. Urinary MH
concentration was higher in patients presenting with early-onset urticaria during
the first hour than in those with the late-onset type between 1 and 12 hr after
DHC. The coefficient of methylation (plasma MH/MH+H) was not significantly
different in patients presenting with an attack of urticaria following DHC and in
other subjects. Urinary excretion of MH and urinary flow increased significantly
in patients presenting with an attack of urticaria following DHC which
corresponds to increased absorption of histamine during the 5-hr period following
DHC and its role on excretion by the kidney via vasodilation which it induces.
This study demonstrates the abnormal frequency of disturbances in the metabolism
of exogenous histamine in patients with CU. Increased plasma H accounts for the
abnormal passage of H across the intestinal barrier which can result either from
intestinal hyperpermeability and/or a deficit in the enzymatic catabolism of
histamine. The systems of methylation and urinary clearance of MH appear to be
effective. It is thus postulated that there is a deficit in diamine oxidase (DAO)
in the enterocyte. The lack of correlation between the kinetic behaviour of
plasma H and the onset of urticaria draws attention to the extent of individual
variability in skin reactivity to histamine.
PMID- 10779296
TI - Influence of allergen avoidance at high altitude on serum markers of eosinophil
activation in children with allergic asthma.
AB - A cohort of 12 asthmatic children was followed over several months, during which
they moved back and forth from an allergen-free to an allergen-rich environment
at high and low altitude, respectively. The children were treated with non
steroidal anti-asthmatic drugs as clinically needed. Histamine PC20-FEV1 was
unaltered during the study period, whereas serum levels of eosinophil cationic
protein (ECP) and eosinophil protein X (EPX) showed significant changes when the
children were exposed to the offending allergens. The total IgE significantly
increased during exposure. The serum levels of myeloperoxidase (MPO) as well as
of chemotactic factors for both neutrophils and eosinophils were unaltered during
allergen exposure. We conclude that the serum markers of eosinophil activity ECP
and EPX are sensitive indices of allergen exposure in asthmatic atopic children.
PMID- 10779297
TI - Interleukin-8 is a chemo-attractant for eosinophils purified from subjects with a
blood eosinophilia but not from normal healthy subjects.
AB - Interleukin-8 (IL-8), a pro-inflammatory cytokine with potent neutrophil
chemotactic activity, was studied for its effect on eosinophil migration
responses, in vitro. Normal density eosinophils were isolated from healthy, non
atopic subjects (<0.35 x 10(9) eosinophils/l) and individuals with various
diseases associated with a blood eosinophilia (range 0.56 x 10(9)-12.2 x 10(9)
eosinophils/l). IL-8 produced a dose-dependent migrational response for
eosinophils from subjects with an eosinophilia, optimal at 10(-8) M (P < 0.01)
and the major component of the migrational response was chemokinesis. On a molar
basis, IL-8 (EC50 approximately 10(10) M) was 100-fold more potent than platelet
activating factor (PAF), although a comparison of the migrational responses
showed that at optimal concentrations IL-8 (10(-8) M) produced only 30% maximal
responses stimulated by PAF (10(-6) M). In contrast, IL-8 tested over a wide
concentration range had a negligible effect on eosinophils from normal subjects.
A direct correlation between the total blood eosinophil counts for all subjects
and the absolute magnitude of the migrational response to IL-8 (r = 0.727, P <
0.01 at 10(-8) M), PAF (r = 0.551, P < 0.03 at 10(-6) M) and N-formyl-methionyl
leucyl-phenylalanine (fMLP) (r = 0.689, P < 0.02 at 10(-8) M), suggested that
heightened eosinophil migrational responses to inflammatory mediators may arise
as a consequence of in vivo priming mechanism(s) associated with the development
of an eosinophilia. In this regard, eosinophils derived from human cord blood
mononuclear cells cultured in the presence of eosinophilopoietic cytokines IL-3
and IL-5, produced migrational responses to IL-8 and PAF, that were comparable
with that of eosinophils from eosinophilic subjects. Furthermore, incubation of
eosinophils from normal donors with IL-5 (optimal concentration 10(-9) M),
significantly enhanced the subsequent migrational responses to both IL-8 (10(-8)
M, P < 0.01) and PAF (10(-8) M, P < 0.05). Therefore, the increased
responsiveness of eosinophils from eosinophilic subjects may reflect in vivo
priming by IL-5 and this phenomenon may contribute partly to the mechanism(s) by
which eosinophils preferentially accumulate at sites of allergic inflammation.
PMID- 10779298
TI - The effectiveness of a peripatetic allergy nurse practitioner service in managing
atopic allergy in general practice--a pilot study.
AB - The effectiveness of an allergy nurse practitioner service operating within
community health care was evaluated in terms of symptom improvement and reduction
in allergy related general practitioner consultations and prescribed medication.
A postal questionnaire survey of 53 allergy patients, identified from three
general practices in the Norwich area during a pilot scheme, was carried out
concurrently with a survey of the patients' case records at the surgeries. The
questionnaire included questions concerning allergy status, general practitioner
visits and the number of prescribed medications supplied. The main outcome
measures were the number of general practitioner consultations and prescribed
medications before and after the allergy nurse practitioner consultation and the
patient's reported level of symptoms. The results showed that the intervention of
an allergy nurse practitioner consultation produced significant reductions in the
outcome measures. The number requiring a general practitioner consultation fell
by 40% (from 133 to 80, P < 0.001) and the number of prescribed medications fell
by 42% (from 153 to 89, P < 0.001). Twenty-seven (69%) of the 39 patients who
responded to the questionnaire reported an improvement in symptoms, whilst 26% (n
= 10) remained the same and 5% (n = 2) were worse. An additional study of 23 of
the +ve skin-tested patients, over an extended period, showed greater reductions
in general practitioner consultations and prescribed medication (71%, P < 0.001
and 59%, P < 0.004 respectively). In conclusion, it is apparent that the
application of developed skills and expertise in allergy assessment by a nurse
coupled with time can lead to improvement in symptom level in allergy patients.
Such a service also has the possibility of providing savings within the National
Health Service. Simply prescribing drugs without a system of self-management and
avoidance measures is unlikely to improve the care available to allergy patients.
PMID- 10779299
TI - Longitudinal changes in skin-prick test reactivity.
PMID- 10779300
TI - Signal transduction mechanisms in human eosinophils.
PMID- 10779301
TI - The circulating renin-angiotensin system and the response to hypotension.
PMID- 10779302
TI - Crustacea allergy.
PMID- 10779303
TI - The aerodynamic characteristics of cat allergen.
AB - To further characterize airborne cat allergen and a newly established cat
challenge facility, airborne Fel d I levels and particle size distributions were
studied in both the cat challenge room and home environments under different
conditions of ventilation and physical activity. In the cat room, there has been
a dramatic and continued rise in the concentration of airborne Fel d I since the
room was established. No differences in total airborne Fel d I levels or particle
size distribution were detected under widely differing rates of ventilation (40
air changes per hour vs 8 ac/hr vs < 1 ac/hr). Likewise, altering ventilation had
little effect on the clearance of airborne antigen after disturbance. Significant
increases in allergen levels were detected, however, after simply allowing the
cats to leave their holding cage and move about the room. Fel d I levels in homes
ranged from 2-468.5 ng/m3, similar to the levels seen in the cat room without
disturbance. Fel d I particle size distribution was very consistent in both homes
and the cat room with the majority of airborne Fel d I being detected on
particles > 17 microm. Although very little allergen (< 15%) was detected on
particles < 4 microm, this important fraction was present under all conditions.
We conclude that airborne cat allergen resides primarily on relatively large
particles, that a small but consistent fraction is found on very small particles,
and that neither allergen levels or particles size distribution are significantly
influenced by ventilation.
PMID- 10779304
TI - Exposure to house dust mite allergen of children admitted to hospital with
asthma.
AB - Eighty-two children admitted to hospital with exacerbations of asthma were
studied to determine how many were exposed to house dust mites at the time of
admission and displayed immediate hypersensitivity to house dust mites. The
concentration of house dust mite allergen (Der p I) was measured in dust obtained
from the child's mattress, bedroom floor and living room floor. Sixty-two (75%)
children admitted had been exposed to > 10 microg Der p I/g. Sixty-seven (82%)
children were sensitive to house dust mite (RAST > or = 1 +, or weal > or = 3
mm): 49 (60%) children were both exposed and sensitive. In contrast in a control
group of 44 children, 31 (70%) (n.s.) were exposed to > 10 microg Der p I/g, 10
(23%) (P<0.001) were sensitive to house dust mite, and 7 (16%) (P<0.001) were
both exposed and sensitive. Seventy-three homes were revisited 6 months after the
child's initial admission. During the preceding month 14 children had been
readmitted, 12 were fully investigated; of these 10 were both sensitive to house
dust mite and still exposed to > 10 microg Der p I/g. In contrast, of the
remaining 62 children who were not readmitted, only 19 were both sensitive and
still exposed to > 10 microg Der p I/g (P<0.001). In conclusion, the majority of
children admitted to hospital with exacerbations of asthma were exposed to house
dust mite allergen and were house dust mite sensitive. Further the results
suggest that continued exposure to higher concentrations of mite allergen may be
associated with the risk of readmission.
PMID- 10779305
TI - Monoclonal antibody immunoassay for quantitative analysis of group V allergens in
grass pollen extracts.
AB - A two-site monoclonal antibody (MoAb) ELISA has been developed for the
quantification of the Phleum pratense major allergen, Phl p V. The assay is based
on two MoAbs which recognize different non-overlapping epitopes on the Phl p V
molecule; one antibody (1D11) was immobilized on the solid phase and the other
(3B2) was biotinylated. An affinity-purified Phl p V preparation (purity of 95%)
was used as standard. The assay has a sensitivity of 10 ng/ml of allergen and is
suitable for the detection of group V allergen in aqueous grass extracts. The
specificity of the assay was investigated with 14 grass pollen and five non-grass
pollen extracts. Different levels of group V allergen were detected in extracts
of grasses, but not in non-grasses. The assay gives a good correspondence with
allergenic activity of extracts as determined by ELISA inhibition using serum
pool of allergic patients. The results indicate that the two-site MoAb ELISA
could be very useful in the standardization of allergenic extracts from grass
pollen.
PMID- 10779306
TI - Allergens from birch pollen and pollen of the European chestnut share common
epitopes.
AB - Type I allergy to pollen of the European chestnut (Castanea sativa) represents a
major cause of pollinosis in (sub) Mediterranean areas. Using sera from 14
patients with established allergy to pollen of the European chestnut, 13/14 sera
(92%) showed IgE-binding to a 22 kD protein, 2/14 (14%) displayed additional
binding to a 14 kD protein and 1/14 (7%) bound only to the 14 kD protein of
European chestnut pollen extract. Two monoclonal mouse antibodies, BIP 1 and BIP
4, directed against different epitopes of Bet v I (the major birch pollen
allergen), and a rabbit antibody to recombinant birch profilin (rBet v II) were
used to characterize the proteins of the European chestnut pollen. The
recombinant birch pollen allergens, rBet v I and rBet v II (profilin) were
employed to show common allergenic structures on proteins from both birch and
European chestnut pollen by IgE-inhibition experiments. Despite the fact that the
22 kD protein displayed a higher molecular weight in comparison to the 17 kD
major birch pollen allergen, Bet v I, we could demonstrate reactivity of both
monoclonal antibodies, BIP 1 and BIP 4, with this protein. A complete inhibiton
of IgE-binding to this 22 kD protein was shown by pre-incubating sera with
purified recombinant Bet v I. In addition, the 14 kD protein could be identified
by IgE-inhibition studies with recombinant Bet v II and by using a rabbit anti
profilin antibody as the profilin from pollen of the European chestnut.
PMID- 10779307
TI - The renin angiotensin system and hymenoptera venom anaphylaxis.
AB - Components of the renin angiotensin system, namely renin, angiotensinogen,
angiotensin I and II and aldosterone were measured in plasma of patients with
hymenoptera venom anaphylaxis (n = 50) and healthy non-allergic controls (n =
25). Patients with a history of anaphylactic reactions to hymenoptera venom who
did not undergo immunotherapy showed significantly reduced renin,
angiotensinogen, angiotensin I and angiotensin II in plasma as compared with
controls (P < 0.05). There was no difference in the aldosterone concentration
between patients and controls. Angiotensin I, angiotensin II, renin and
angiotensinogen levels were the same in male and female patients. There was also
no difference in the angiotensin I, II, renin or angiotensinogen levels between
young and older patients. A significant inverse correlation between the severity
of clinical symptoms and the plasma levels of renin (r = -0.382, P < 0.001),
angiotensinogen (r = -0.567, P < 0.0001), angiotensin I (r = -0.656, P < 0.0001)
and angiotensin II (r = 0.0762, P < 0.0001) was found: the lower the levels the
more severe the clinical symptoms. No correlation was found for aldosterone.
Hymenoptera venom allergic patients with repeated anaphylactic reactions during
hyposensitization did not tolerate the sting of a living insect (n = 6). In these
patients, renin, angiotensinogen, angiotensin I and II remained significantly
lower than in healthy non-allergic controls. Patients with successful
immunotherapy (n = 27) who tolerated the sting of a living insect had renin,
angiotensin I and II significantly higher than patients without immunotherapy.
These findings suggest a possible role of the renin angiotensin system in
hymenoptera venom anaphylaxis.
PMID- 10779308
TI - Formation of phosphatidylinositol-4-phosphate in human peripheral blood
eosinophils.
AB - To evaluate the presence of phosphatidylinositol-4-phosphate in peripheral blood
eosinophils, venous blood was drawn from normal healthy volunteers. The
eosinophils were isolated on a Percoll gradient and were incubated with
[gamma32P]ATP in the presence of Mg2+. After stopping the reaction, lipid
extraction was performed with acidic medium and phospholipids were separated by
thin-layer chromatography on 1% (w/v) oxalic acid- and potassium oxalate
impregnated silica gel plates. Considerable amounts of radioactivity were found
to be incorporated into phosphatidylinositol-4-phosphate on both plates. This
reaction requires ATP and Mg2+, and maximal response is seen at 10 microM ATP and
20 mM Mg2+. The reaction is dependent upon the time and temperature of the assay
system. No significant superoxide anion generation from the eosinophils incubated
with ATP at the concentrations used in the study was observed. These results
suggest the possible presence of phosphatidylinositol kinase which catalyses the
formation of phosphatidylinositol-4-phosphate from endogenous
phosphatidylinositol in human peripheral blood eosinophils.
PMID- 10779309
TI - Trypsin-like protease of mites: purification and characterization of trypsin-like
protease from mite faecal extract Dermatophagoides farinae. Relationship between
trypsin-like protease and Der f III.
AB - A serine protease from mite faecal extract, Dermatophagoides farinae, was
purified using DEAE-Sephacel anion exchange chromatography and Superdex 75 pg gel
chromatography. The molecular weight of this protease was 34 kD on SDS-PAGE under
reducing conditions. The optimal pH and temperature of the protease were 8.0 and
47 degrees C, respectively. In addition, this protease cleaved arginyl or lysyl
residue containing substrates selectively and was only inhibited by aprotinin,
FUT-175, and soy bean trypsin inhibitor and not by chymostatin, E-64 and
iodoacetic acid. These results show that our purified serine protease belongs to
the trypsin-type. Purified trypsin-like protease was shown to be allergenic by
enzyme-linked immunosorbent assay. Antigenicity of trypsin-like protease was
completely different from those of Der f I and Der f II. Both, 20 N-terminal
amino acid sequence and amino acid compositions of the purified protease were
very similar to those of Der f III. Good similarities were found between trypsin
like protease and Der f III concerning physicochemical properties such as
molecular weight on SDS-PAGE and ammonium sulphate solubility. Summarizing the
above data, it can be concluded that a trypsin-like protease from mite faecal
extract is actually the Der f III allergen and that it may be involved in the
digestive process of the mite as it was found not in mite body but in mite
faeces.
PMID- 10779310
TI - Treatment of steroid-dependent asthma with recombinant interferon-gamma.
AB - We have recently reported that treatment of patients with severe atopic
dermatitis with recombinant interferon-gamma (rIFN-gamma) resulted in clinical
improvement as well as a reduction of circulating eosinophils. Since IgE
dependent late phase allergic reactions and eosinophilic infiltration are thought
to play an important role in the pathogenesis of asthma, we conducted a two
centre randomized double-blind placebo-controlled trial of rIFN-gamma in the
treatment of steroid-dependent asthma. Patients were treated with daily
subcutaneous injections of either 0.05 mg/m2 rIFN-gamma (n = 9) or placebo (n =
11) for 90 days. All patients completed the study without significant drug
toxicity noted. Oral prednisone dose, forced expiratory volume in 1 second
(FEV1), peak expiratory flow rates (PEFR) and circulating eosinophil counts were
monitored throughout the trial. There was no significant difference between the
two treatment groups in per cent reduction from baseline of daily prednisone (P =
0.51). There was also no significant difference between the two treatment groups
in per cent change from baseline in FEV1 (P = 0.54) or in PEFR (P = 0.75). Total
circulating eosinophil counts decreased by 31% in the rIFN-gamma group and
increased by 8.5% in the placebo group (P = 0.09). We conclude that this
treatment regimen was not effective in patients with steroid-dependent asthma.
PMID- 10779311
TI - Rapid onset of action of levocabastine eye-drops in histamine-induced
conjunctivitis.
AB - Levocabastine is a recently developed, potent H1-receptor blocker intended for
topical application. Seventeen healthy non-atopic volunteers participated in this
randomized, double-blind, placebo-controlled study undertaken to investigate the
speed of onset of action, efficacy and tolerability of levocabastine eye-drops
after a histamine challenge. The degree of histamine-induced ocular inflammation
was found to be significantly less after administration of levocabastine compared
with placebo. Furthermore, levocabastine was shown to be rapidly effective with
an onset of action within 10 min. Levocabastine eye-drops were well-tolerated and
no adverse reactions to the study drug were reported. Levocabastine eye-drops
appear to be a valuable therapeutic approach for the treatment of histamine
mediated ocular allergies.
PMID- 10779312
TI - Extracellular HCO(3)(-) dependence of electrogenic Na/HCO(3) cotransporters
cloned from salamander and rat kidney.
AB - We studied the extracellular [HCOabstract (3) (-)] dependence of two renal clones
of the electrogenic Na/HCO(3) cotransporter (NBC) heterologously expressed in
Xenopus oocytes. We used microelectrodes to measure the change in membrane
potential (DeltaV(m)) elicited by the NBC cloned from the kidney of the
salamander Ambystoma tigrinum (akNBC) and by the NBC cloned from the kidney of
rat (rkNBC). We used a two-electrode voltage clamp to measure the change in
current (DeltaI) elicited by rkNBC. Briefly exposing an NBC-expressing oocyte to
HCOabstract (3 )(-)/CO(2) (0.33-99 mM HCOabstract (3)(-), pH(o) 7.5) elicited an
immediate, DIDS (4, 4-diisothiocyanatostilbene-2,2-disulfonic acid)-sensitive and
Na(+)-dependent hyperpolarization (or outward current). In DeltaV(m) experiments,
the apparent K(m ) for HCOabstract (3)(-) of akNBC (10. 6 mM) and rkNBC (10.8 mM)
were similar. However, under voltage-clamp conditions, the apparent K(m) for
HCOabstract (3)(-) of rkNBC was less (6.5 mM). Because it has been reported that
SOabstract (3)(=)/HSO abstract (3)(-) stimulates Na/HCO(3 ) cotransport in renal
membrane vesicles (a result that supports the existence of a COabstract (3)(=)
binding site with which SOabstract (3)(=) interacts), we examined the effect of
SOabstract (3)(=)/HSO abstract (3)(-) on rkNBC. In voltage-clamp studies, we
found that neither 33 mM SOabstract (4)(=) nor 33 mM SOabstract (3)
(=)/HSOabstract (3)(-) substantially affects the apparent K(m) for HCO abstract
(3)(-). We also used microelectrodes to monitor intracellular pH (pH(i)) while
exposing rkNBC-expressing oocytes to 3.3 mM HCOabstract (3 )(-)/0.5% CO(2). We
found that SO abstract (3)(=)/HSOabstract (3 )(-) did not significantly affect
the DIDS-sensitive component of the pH(i) recovery from the initial CO(2 )
induced acidification. We also monitored the rkNBC current while simultaneously
varying [CO(2)](o), pH(o), and [COabstract (3)(=)](o) at a fixed [HCOabstract
(3)(-)](o) of 33 mM. A Michaelis-Menten equation poorly fitted the data expressed
as current versus [COabstract (3)(=)](o ). However, a pH titration curve nicely
fitted the data expressed as current versus pH(o). Thus, rkNBC expressed in
Xenopus oocytes does not appear to interact with SOabstract (3 )(=), HSOabstract
(3)(-), or COabstract (3)(=).
PMID- 10779314
TI - Specific and nonspecific effects of protein kinase C on the epithelial Na (+)
channel.
AB - The Xenopus oocyte expression system was used to explore the mechanisms of
inhibition of the cloned rat epithelial Na(+) channel (rENaC) by PKC (Awayda,
M.S., I.I. Ismailov, B.K. Berdiev, C.M. Fuller, and D.J. Benos. 1996. J. Gen.
Physiol. 108:49-65) and to determine whether human ENaC exhibits similar
regulation. Effects of PKC activation on membrane and/or channel trafficking were
determined using impedance analysis as an indirect measure of membrane area.
hENaC-expressing oocytes exhibited an appreciable activation by hyperpolarizing
voltages. This activation could be fit with a single exponential, described by a
time constant (tau) and a magnitude (DeltaI (V)). A similar but smaller magnitude
of activation was also observed in oocytes expressing rENaC. This activation
likely corresponds to the previously described effect of hyperpolarizing voltage
on gating of the native Na(+) channel (Palmer, L.G., and G. Frindt. 1996. J. Gen.
Physiol. 107:35-45). Stimulation of PKC with 100 nM PMA decreased DeltaI(V) in
hENaC-expressing oocytes to a plateau at 57.1 +/- 4.9% (n = 6) of baseline values
at 20 min. Similar effects were observed in rENaC-expressing oocytes. PMA
decreased the amiloride-sensitive hENaC slope conductance (g(Na)) to 21.7 +/-
7.2% (n = 6) of baseline values at 30 min. This decrease was similar to that
previously reported for rENaC. This decrease of g (Na) was attributed to a
decrease of membrane capacitance (C (m)), as well as the specific conductance
(g(m)/C(m )). The effects on g(m)/C(m) reached a plateau within 15 min, at
approximately 60% of baseline values. This decrease is likely due to the specific
ability of PKC to inhibit ENaC. On the other hand, the decrease of C(m) was
unrelated to ENaC and is likely an effect of PKC on membrane trafficking, as it
was observed in ENaC-expressing as well as control oocytes. At lower PMA
concentrations (0.5 nM), smaller changes of C(m) were observed in rENaC- and
hENaC-expressing oocytes, and were preceded by larger changes of g(m ) and by
changes of g(m)/C(m), indicating specific effects on ENaC. These findings
indicate that PKC exhibits multiple and specific effects on ENaC, as well as
nonspecific effects on membrane trafficking. Moreover, these findings provide the
electrophysiological basis for assessing channel-specific effects of PKC in the
Xenopus oocyte expression system.
PMID- 10779313
TI - Heterologous facilitation of G protein-activated K(+) channels by beta-adrenergic
stimulation via cAMP-dependent protein kinase.
AB - To investigate possible effects of adrenergic stimulation on G protein-activated
inwardly rectifying K(+) channels (GIRK), acetylcholine (ACh)-evoked K(+)
current, I(KACh), was recorded from adult rat atrial cardiomyocytes using the
whole cell patch clamp method and a fast perfusion system. The rise time of
I(KACh ) was 0. 4 +/- 0.1 s. When isoproterenol (Iso) was applied simultaneously
with ACh, an additional slow component (11.4 +/- 3.0 s) appeared, and the
amplitude of the elicited I(KACh) was increased by 22.9 +/- 5.4%. Both the slow
component of activation and the current increase caused by Iso were abolished by
preincubation in 50 microM H89 (N-[2-((p -bromocinnamyl)amino)ethyl]-5
isoquinolinesulfonamide, a potent inhibitor of PKA). This heterologous
facilitation of GIRK current by beta-adrenergic stimulation was further studied
in Xenopus laevis oocytes coexpressing beta(2)-adrenergic receptors, m(2 )
receptors, and GIRK1/GIRK4 subunits. Both Iso and ACh elicited GIRK currents in
these oocytes. Furthermore, Iso facilitated ACh currents in a way, similar to
atrial cells. Cytosolic injection of 30-60 pmol cAMP, but not of Rp-cAMPS (a cAMP
analogue that is inhibitory to PKA) mimicked the beta(2)-adrenergic effect. The
possibility that the potentiation of GIRK currents was a result of the
phosphorylation of the beta-adrenergic receptor (beta(2)AR) by PKA was excluded
by using a mutant beta(2)AR in which the residues for PKA-mediated modulation
were mutated. Overexpression of the alpha subunit of G proteins (Galpha(s)) led
to an increase in basal as well as agonist-induced GIRK1/GIRK4 currents
(inhibited by H89). At higher levels of expressed Galpha(s), GIRK currents were
inhibited, presumably due to sequestration of the beta/gamma subunit dimer of G
protein. GIRK1/GIRK5, GIRK1/GIRK2, and homomeric GIRK2 channels were also
regulated by cAMP injections. Mutant GIRK1/GIRK4 channels in which the 40 COOH
terminal amino acids (which contain a strong PKA phosphorylation consensus site)
were deleted were also modulated by cAMP injections. Hence, the structural
determinant responsible is not located within this region. We conclude that, both
in atrial myocytes and in Xenopus oocytes, beta-adrenergic stimulation
potentiates the ACh-evoked GIRK channels via a pathway that involves PKA
catalyzed phosphorylation downstream from beta(2)AR.
PMID- 10779315
TI - Annexins V and XII alter the properties of planar lipid bilayers seen by
conductance probes.
AB - Annexins are proteins that bind lipids in the presence of calcium. Though
multiple functions have been proposed for annexins, there is no general agreement
on what annexins do or how they do it. We have used the well-studied conductance
probes nonactin, alamethicin, and tetraphenylborate to investigate how annexins
alter the functional properties of planar lipid bilayers. We found that annexin
XII reduces the nonactin-induced conductance to approximately 30% of its original
value. Both negative lipid and approximately 30 microM Ca(2+) are required for
the conductance reduction. The mutant annexin XIIs, E105K and E105K/K68A, do not
reduce the nonactin conductance even though both bind to the membrane just as
wild-type does. Thus, subtle changes in the interaction of annexins with the
membrane seem to be important. Annexin V also reduces nonactin conductance in
nearly the same manner as annexin XII. Pronase in the absence of annexin had no
effect on the nonactin conductance. But when added to the side of the bilayer
opposite that to which annexin was added, pronase increased the nonactin-induced
conductance toward its pre-annexin value. Annexins also dramatically alter the
conductance induced by a radically different probe, alamethicin. When added to
the same side of the bilayer as alamethicin, annexin has virtually no effect, but
when added trans to the alamethicin, annexin dramatically reduces the asymmetry
of the I-V curve and greatly slows the kinetics of one branch of the curve
without altering those of the other. Annexin also reduces the rate at which the
hydrophobic anion, tetraphenylborate, crosses the bilayer. These results suggest
that annexin greatly reduces the ability of small molecules to cross the membrane
without altering the surface potential and that at least some fraction of the
active annexin is accessible to pronase digestion from the opposite side of the
membrane.
PMID- 10779316
TI - Identification of a peptide toxin from Grammostola spatulata spider venom that
blocks cation-selective stretch-activated channels.
AB - We have identified a 35 amino acid peptide toxin of the inhibitor cysteine knot
family that blocks cationic stretch-activated ion channels. The toxin, denoted
GsMTx-4, was isolated from the venom of the spider Grammostola spatulata and has
<50% homology to other neuroactive peptides. It was isolated by fractionating
whole venom using reverse phase HPLC, and then assaying fractions on stretch
activated channels (SACs) in outside-out patches from adult rat astrocytes.
Although the channel gating kinetics were different between cell-attached and
outside-out patches, the properties associated with the channel pore, such as
selectivity for alkali cations, conductance ( approximately 45 pS at -100 mV) and
a mild rectification were unaffected by outside-out formation. GsMTx-4 produced a
complete block of SACs in outside-out patches and appeared specific since it had
no effect on whole-cell voltage-sensitive currents. The equilibrium dissociation
constant of approximately 630 nM was calculated from the ratio of association and
dissociation rate constants. In hypotonically swollen astrocytes, GsMTx-4
produces approximately 40% reduction in swelling-activated whole-cell current.
Similarly, in isolated ventricular cells from a rabbit dilated cardiomyopathy
model, GsMTx-4 produced a near complete block of the volume-sensitive cation
selective current, but did not affect the anion current. In the myopathic heart
cells, where the swell-induced current is tonically active, GsMTx-4 also reduced
the cell size. This is the first report of a peptide toxin that specifically
blocks stretch-activated currents. The toxin affect on swelling-activated whole
cell currents implicates SACs in volume regulation.
PMID- 10779317
TI - Polarization of Na(+)/H(+) and Cl(-)/HCO (3)(-) exchangers in migrating renal
epithelial cells.
AB - Cell migration is crucial for processes such as immune defense, wound healing, or
the formation of tumor metastases. Typically, migrating cells are polarized
within the plane of movement with lamellipodium and cell body representing the
front and rear of the cell, respectively. Here, we address the question of
whether this polarization also extends to the distribution of ion transporters
such as Na(+)/H(+) exchanger (NHE) and anion exchanger in the plasma membrane of
migrating cells. Both transporters are required for locomotion of renal
epithelial (Madin-Darby canine kidney, MDCK-F) cells and human melanoma cells
since their blockade reduces the rate of migration in a dose-dependent manner.
Inhibition of migration of MDCK-F cells by NHE blockers is accompanied by a
decrease of pH(i). However, when cells are acidified with weak organic acids,
migration of MDCK-F cells is normal despite an even more pronounced decrease of
pH(i). Under these conditions, NHE activity is increased so that cells are
swelling due to the accumulation of organic anions and Na(+). When exclusively
applied to the lamellipodium, blockers of NHE or anion exchange inhibit migration
of MDCK-F cells as effectively as when applied to the entire cell surface. When
they are directed to the cell body, migration is not affected. These data are
confirmed immunocytochemically in that the anion exchanger AE2 is concentrated at
the front of MDCK-F cells. Our findings show that NHE and anion exchanger are
distributed in a polarized way in migrating cells. They are consistent with
important contributions of both transporters to protrusion of the lamellipodium
via solute uptake and consequent volume increase at the front of migrating cells.
PMID- 10779318
TI - The role of the putative inactivation lid in sodium channel gating current
immobilization.
AB - We investigated the contribution of the putative inactivation lid in voltage
gated sodium channels to gating charge immobilization (i.e., the slow return of
gating charge during repolarization) by studying a lid-modified mutant of the
human heart sodium channel (hH1a) that had the phenylalanine at position 1485 in
the isoleucine, phenylalanine, and methionine (IFM) region of the domain III-IV
linker mutated to a cysteine (ICM-hH1a). Residual fast inactivation of ICM-hH1a
in fused tsA201 cells was abolished by intracellular perfusion with 2.5 mM 2
(trimethylammonium)ethyl methanethiosulfonate (MTSET). The time constants of
gating current relaxations in response to step depolarizations and gating charge
voltage relationships were not different between wild-type hH1a and ICM
hH1a(MTSET). The time constant of the development of charge immobilization
assayed at -180 mV after depolarization to 0 mV was similar to the time constant
of inactivation of I(Na) at 0 mV for hH1a. By 44 ms, 53% of the gating charge
during repolarization returned slowly; i.e., became immobilized. In ICM
hH1a(MTSET), immobilization occurred with a similar time course, although only
31% of gating charge upon repolarization (OFF charge) immobilized. After
modification of hH1a and ICM-hH1a(MTSET) with Anthopleurin-A toxin, a site-3
peptide toxin that inhibits movement of the domain IV-S4, charge immobilization
did not occur for conditioning durations up to 44 ms. OFF charge for both hH1a
and ICM-hH1a(MTSET) modified with Anthopleurin-A toxin were similar in time
course and in magnitude to the fast component of OFF charge in ICM-hH1a(MTSET) in
control. We conclude that movement of domain IV-S4 is the rate-limiting step
during repolarization, and it contributes to charge immobilization regardless of
whether the inactivation lid is bound. Taken together with previous reports,
these data also suggest that S4 in domain III contributes to charge
immobilization only after binding of the inactivation lid.
PMID- 10779319
TI - Kinetic, mechanistic, and structural aspects of unliganded gating of
acetylcholine receptor channels: a single-channel study of second transmembrane
segment 12' mutants.
AB - The spontaneous activity of adult mouse muscle acetylcholine receptor channels,
transiently expressed in HEK-293 cells, was studied with the patch-clamp
technique. To increase the frequency of unliganded openings, mutations at the 12'
position of the second transmembrane segment were engineered. Our results
indicate that: (a) in both wild type and mutants, a C <--> O kinetic scheme
provides a good description of spontaneous gating. In the case of some mutant
constructs, however, additional states were needed to improve the fit to the
data. Similar additional states were also needed in one of six patches containing
wild-type acetylcholine receptor channels; (b) the delta12' residue makes a more
pronounced contribution to unliganded gating than the homologous residues of the
alpha, beta, and straightepsilon subunits; (c) combinations of second
transmembrane segment 12' mutations in the four different subunits appear to have
cumulative effects; (d) the volume of the side chain at delta12' is relevant
because residues larger than the wild-type Ser increase spontaneous gating; (e)
the voltage dependence of the unliganded gating equilibrium constant is the same
as that of diliganded gating, but the voltage dependences of the opening and
closing rate constants are opposite (this indicates that the reaction pathway
connecting the closed and open states of the receptor changes upon ligation); (f)
engineering binding-site mutations that decrease diliganded gating (alphaY93F,
alphaY190W, and alphaD200N) reduces spontaneous activity as well (this suggests
that even in the absence of ligand the opening of the channel is accompanied by a
conformational change at the binding sites); and (g) the diliganded gating
equilibrium constant is also increased by the 12' mutations. Such increase is
independent of the particular ligand used as the agonist, which suggests that
these mutations affect mostly the isomerization step, having little, if any,
effect on the ligand-affinity ratio.
PMID- 10779321
TI - Calcium-induced calcium release in smooth muscle: loose coupling between the
action potential and calcium release.
AB - Calcium-induced calcium release (CICR) has been observed in cardiac myocytes as
elementary calcium release events (calcium sparks) associated with the opening of
L-type Ca(2+) channels. In heart cells, a tight coupling between the gating of
single L-type Ca(2+) channels and ryanodine receptors (RYRs) underlies calcium
release. Here we demonstrate that L-type Ca(2+) channels activate RYRs to produce
CICR in smooth muscle cells in the form of Ca(2+) sparks and propagated Ca(2+)
waves. However, unlike CICR in cardiac muscle, RYR channel opening is not tightly
linked to the gating of L-type Ca(2+) channels. L-type Ca(2+) channels can open
without triggering Ca(2+) sparks and triggered Ca(2+) sparks are often observed
after channel closure. CICR is a function of the net flux of Ca(2+) ions into the
cytosol, rather than the single channel amplitude of L-type Ca(2+) channels.
Moreover, unlike CICR in striated muscle, calcium release is completely
eliminated by cytosolic calcium buffering. Thus, L-type Ca(2+) channels are
loosely coupled to RYR through an increase in global [Ca(2+)] due to an increase
in the effective distance between L-type Ca(2+) channels and RYR, resulting in an
uncoupling of the obligate relationship that exists in striated muscle between
the action potential and calcium release.
PMID- 10779320
TI - Asymmetric and independent contribution of the second transmembrane segment 12'
residues to diliganded gating of acetylcholine receptor channels: a single
channel study with choline as the agonist.
AB - Mutagenesis studies have suggested that the second transmembrane segment (M2)
plays a critical role during acetylcholine receptor liganded gating. An adequate
description of the relationship between gating and structure of the M2 domain,
however, has been hampered by the fact that many M2 mutations increase the
opening rate constant to levels that, in the presence of acetylcholine, are
unresolvably fast. Here, we show that the use of saturating concentrations of
choline, a low-efficacy agonist, is a convenient tool to circumvent this problem.
In the presence of 20 mM choline: (a) single-channel currents occur in clusters;
(b) fast blockade by choline itself reduces the single-channel conductance by
approximately 50%, yet the excess open-channel noise is only moderate; (c) the
kinetics of gating are fitted best by a single-step, C <--> O model; and (d)
opening and closing rate constants are within a well resolvable range.
Application of this method to a series of recombinant adult mouse muscle M2 12'
mutants revealed that: (a) the five homologous M2 12' positions make independent
and asymmetric contributions to diliganded gating, the delta subunit being the
most sensitive to mutation; (b) mutations at delta12' increase the diliganded
gating equilibrium constant in a manner that is consistent with the sensitivity
of the transition state to mutation being approximately 30% like that of the open
state and approximately 70% like that of the closed state; (c) the relationship
between delta12' amino acid residue volume, hydrophobicity or alpha-helical
tendency, and the gating equilibrium constant of the corresponding mutants is not
straightforward; however, (d) rate and equilibrium constants for the mutant
series are linearly correlated (on log-log plots), which suggests that the
conformational rearrangements upon mutation are mostly local and that the
position of the transition state along the gating reaction coordinate is
unaffected by these mutations.
PMID- 10779322
TI - Nicotinic receptor fourth transmembrane domain: hydrogen bonding by conserved
threonine contributes to channel gating kinetics.
AB - The fourth transmembrane domain (M4) of the nicotinic acetylcholine receptor
(AChR) contributes to the kinetics of activation, yet its close association with
the lipid bilayer makes it the outermost of the transmembrane domains. To
investigate mechanistic and structural contributions of M4 to AChR activation, we
systematically mutated alphaT422, a conserved residue that has been labeled by
hydrophobic probes, and evaluated changes in rate constants underlying ACh
binding and channel gating steps. Aromatic and nonpolar mutations of alphaT422
selectively affect the channel gating step, slowing the rate of opening two- to
sevenfold, and speeding the rate of closing four- to ninefold. Additionally,
kinetic modeling shows a second doubly liganded open state for aromatic and
nonpolar mutations. In contrast, serine and asparagine mutations of alphaT422
largely preserve the kinetics of the wild-type AChR. Thus, rapid and efficient
gating of the AChR channel depends on a hydrogen bond involving the side chain at
position 422 of the M4 transmembrane domain.
PMID- 10779323
TI - Role of the cyclic AMP response element binding complex and activation of mitogen
activated protein kinases in synergistic activation of the glycoprotein hormone
alpha subunit gene by epidermal growth factor and forskolin.
AB - The aim of these studies was to elucidate a role for epidermal growth factor
(EGF) signaling in the transcriptional regulation of the glycoprotein hormone
alpha subunit gene, a subunit of chorionic gonadotropin. Studies examined the
effects of EGF and the adenylate cyclase activator forskolin on the expression of
a transfected alpha subunit reporter gene in a human choriocarcinoma cell line
(JEG3). At maximal doses, administration of EGF resulted in a 50% increase in a
subunit reporter activity; forskolin administration induced a fivefold
activation; the combined actions of EGF and forskolin resulted in synergistic
activation (greater than eightfold) of the alpha subunit reporter. Mutagenesis
studies revealed that the cyclic AMP response elements (CRE) were required and
sufficient to mediate EGF-forskolin-induced synergistic activation. The combined
actions of EGF and forskolin resulted in potentiated activation of extracellular
signal-regulated kinase (ERK) enzyme activity compared with EGF alone. Specific
blockade of ERK activation was sufficient to block EGF-forskolin-induced
synergistic activation of the alpha subunit reporter. Pretreatment of JEG3 cells
with a p38 mitogen-activated protein kinase inhibitor did not influence
activation of the alpha reporter. However, overexpression of c-Jun N-terminal
kinase (JNK)-interacting protein 1 as a dominant interfering molecule abolished
the synergistic effects of EGF and forskolin on the alpha subunit reporter. CRE
binding studies suggested that the CRE complex consisted of CRE binding protein
and EGF-ERK-dependent recruitment of c-Jun-c-Fos (AP-1) to the CRE. A dominant
negative form of c-Fos (A-Fos) that specifically disrupts c-Jun-c-Fos DNA binding
inhibited synergistic activation of the alpha subunit. Thus, synergistic
activation of the alpha subunit gene induced by EGF-forskolin requires the ERK
and JNK cascades and the recruitment of AP-1 to the CRE binding complex.
PMID- 10779324
TI - TLS-ERG leukemia fusion protein inhibits RNA splicing mediated by serine-arginine
proteins.
AB - The translocation liposarcoma (TLS) gene is fused to the ETS-related gene (ERG)
in human myeloid leukemia, resulting in the generation of a TLS-ERG protein. We
demonstrate that both TLS and the TLS-ERG leukemia fusion protein bind to RNA
polymerase II through the TLS N-terminal domain, which is retained in the fusion
protein; however, TLS recruits members of the serine-arginine (SR) family of
splicing factors through its C-terminal domain, whereas the TLS-ERG fusion
protein lacks the ability to recruit SR proteins due to replacement of the C
terminal domain by the fusion partner ERG. In transient-transfection assays, the
TLS-ERG fusion protein inhibits E1A pre-mRNA splicing mediated by these TLS
associated SR proteins (TASR), and stable expression of the TLS-ERG fusion
protein in K562 cells alters the splicing profile of CD44 mRNA. These results
suggest that TLS fusion proteins may lead to cellular abnormalities by
interfering with the splicing of important cellular regulators.
PMID- 10779325
TI - On the mechanism by which alkaline pH prevents expression of an acid-expressed
gene.
AB - Previous work has shown that zinc finger transcription factor PacC mediates the
regulation of gene expression by ambient pH in the fungus Aspergillus nidulans.
This regulation ensures that the syntheses of molecules functioning in the
external environment, such as permeases, secreted enzymes, and exported
metabolites, are tailored to the pH of the growth environment. A direct role for
PacC in activating the expression of an alkaline-expressed gene has previously
been demonstrated, but the mechanism by which alkaline ambient pH prevents the
expression of any eukaryotic acid-expressed gene has never been reported. Here we
show that a double PacC binding site in the promoter of the acid-expressed gabA
gene, encoding gamma-aminobutyrate (GABA) permease, overlaps the binding site for
the transcriptional activator IntA, which mediates omega-amino acid induction.
Using bacterially expressed fusion proteins, we have shown that PacC competes
with IntA for DNA binding in vitro at this site. Thus, PacC repression of GABA
permease synthesis is direct and occurs by blocking induction. A swap of IntA
sites between promoters for gabA and amdS, a gene not subject to pH regulation,
makes gabA expression pH independent and amdS acid expressed.
PMID- 10779326
TI - A functionally essential domain of RFX5 mediates activation of major
histocompatibility complex class II promoters by promoting cooperative binding
between RFX and NF-Y.
AB - Major histocompatibility complex class II (MHC-II) molecules occupy a pivotal
position in the adaptive immune system, and correct regulation of their
expression is therefore of critical importance for the control of the immune
response. Several regulatory factors essential for the transcription of MHC-II
genes have been identified by elucidation of the molecular defects responsible
for MHC-II deficiency, a hereditary immunodeficiency disease characterized by
regulatory defects abrogating MHC-II expression. Three of these factors, RFX5,
RFXAP, and RFXANK, combine to form the RFX complex, a regulatory protein that
binds to the X box DNA sequence present in all MHC-II promoters. In this study we
have undertaken a dissection of the structure and function of RFX5, the largest
subunit of the RFX complex. The results define two distinct domains serving two
different essential functions. A highly conserved N-terminal region of RFX5 is
required for its association with RFXANK and RFXAP, for assembly of the RFX
complex in vivo and in vitro, and for binding of this complex to its X box target
site in the MHC-II promoter. This N-terminal region is, however, not sufficient
for activation of MHC-II expression. This requires an additional domain within
the C-terminal region of RFX5. This C-terminal domain mediates cooperative
binding between the RFX complex and NF-Y, a transcription factor binding to the Y
box sequence of MHC-II promoters. This provides direct evidence that RFX5
mediated cooperative binding between RFX and NF-Y plays an essential role in the
transcriptional activation of MHC-II genes.
PMID- 10779327
TI - Inactivation of p53 by human T-cell lymphotropic virus type 1 Tax requires
activation of the NF-kappaB pathway and is dependent on p53 phosphorylation.
AB - p53 plays a key role in guarding cells against DNA damage and transformation. We
previously demonstrated that the human T-cell lymphotropic virus type 1 (HTLV-1)
Tax can inactivate p53 transactivation function in lymphocytes. The present study
demonstrates that in T cells, Tax-induced p53 inactivation is dependent upon NF
kappaB activation. Analysis of Tax mutants demonstrated that Tax inactivation of
p53 function correlates with the ability of Tax to induce NF-kappaB but not p300
binding or CREB transactivation. The Tax-induced p53 inactivation can be overcome
by overexpression of a dominant IkappaB mutant. Tax-NF-kappaB-induced p53
inactivation is not due to p300 squelching, since overexpression of p300 does not
recover p53 activity in the presence of Tax. Further, using wild-type and p65
knockout mouse embryo fibroblasts (MEFs), we demonstrate that the p65 subunit of
NF-kappaB is critical for Tax-induced p53 inactivation. While Tax can inactivate
endogenous p53 function in wild-type MEFs, it fails to inactivate p53 function in
p65 knockout MEFs. Importantly, Tax-induced p53 inactivation can be restored by
expression of p65 in the knockout MEFs. Finally, we present evidence that
phosphorylation of serines 15 and 392 correlates with inactivation of p53 by Tax
in T cells. This study provides evidence that the divergent NF-kappaB
proliferative and p53 cell cycle arrest pathways may be cross-regulated at
several levels, including posttranslational modification of p53.
PMID- 10779328
TI - Regulation of the Jak2 tyrosine kinase by its pseudokinase domain.
AB - Activation of Jak tyrosine kinases through hematopoietic cytokine receptors
occurs as a consequence of ligand-induced aggregation of receptor-associated Jaks
and their subsequent autophosphorylation. Jak kinases consist of a C-terminal
tyrosine kinase domain, a pseudokinase domain of unknown function, and Jak
homology (JH) domains 3 to 7, implicated in receptor-Jak interaction. We analyzed
the functional roles of the different protein domains in activation of Jak2.
Deletion analysis of Jak2 showed that the pseudokinase domain but not JH domains
3 to 7 negatively regulated the catalytic activity of Jak2 as well as Jak2
mediated activation of Stat5. Phosphorylation of Stat5 by wild-type Jak2 was
dependent on the SH2 domain of Stat5; however, this requirement was lost upon
deletion of the pseudokinase domain of Jak2. Investigation of the mechanisms of
the pseudokinase domain-mediated inhibition of Jak2 suggested that this
regulation did not involve protein tyrosine phosphatases. Instead, analysis of
interactions between the tyrosine kinase domain and Jak2 suggested that the
pseudokinase domain interacted with the kinase domain. Furthermore, coexpression
of the pseudokinase domain inhibited the activity of the single tyrosine kinase
domain. Finally, deletion of the pseudokinase domain of Jak2 deregulated signal
transduction through the gamma interferon receptor by significantly increasing
ligand-independent activation of Stat transcription factors. These results
indicate that the pseudokinase domain negatively regulates the activity of Jak2,
probably through an interaction with the kinase domain, and this regulation is
required to keep Jak2 inactive in the absence of ligand stimulation. Furthermore,
the pseudokinase domain may have a role in regulation of Jak2-substrate
interactions.
PMID- 10779329
TI - Slap negatively regulates Src mitogenic function but does not revert Src-induced
cell morphology changes.
AB - Src-like adapter protein (Slap) is a recently identified protein that negatively
regulates mitogenesis in murine fibroblasts (S. Roche, G. Alonso, A. Kazlausakas,
V. M. Dixit, S. A. Courtneidge, and A. Pandey, Curr. Biol. 8:975-978, 1998) and
comprises an SH3 and SH2 domain with striking identity to the corresponding Src
domains. In light of this, we sought to investigate whether Slap could be an
antagonist of all Src functions. Like Src, Slap was found to be myristylated in
vivo and largely colocalized with Src when coexpressed in Cos7 cells.
Microinjection of a Slap-expressing construct into quiescent NIH 3T3 cells
inhibited platelet-derived growth factor (PDGF)-induced DNA synthesis, and the
inhibition was rescued by the transcription factor c-Myc but not by c-Jun/c-Fos
expression. Fyn (or Src) overexpression overrides the G(1)/S block induced by
both SrcK- and a Slap mutant with a deletion of its C terminus (SlapDeltaC), but
not the block induced by Slap or SlapDeltaSH3, implying that the C terminus is a
noncompetitive inhibitor of Src mitogenic function. Furthermore, a chimeric
adapter comprising SrcDeltaK fused to the Slap C terminus (Src/SlapC) also
inhibited Src function during the PDGF response in a noncompetitive manner, as
Src coexpression could not rescue PDGF signaling. Slap, however, did not reverse
deregulated Src-induced cell transformation, as it was unable to inhibit
depolymerization of actin stress fibers while still being able to inhibit
SrcY527F-induced DNA synthesis. This was attributed to a distinct Slap SH3
binding specificity, since the chimeric Slap/SrcSH3 molecule, in which the Slap
SH3 was replaced by the Src SH3 sequence, substantially restored stress fiber
formation. Indeed, three amino acids important for ligand binding in Src SH3 were
replaced in the Slap SH3 sequence; Slap SH3 did not bind to the Src SH3 partners
p85alpha, Shc, and Sam68 in vitro, and the chimeric tyrosine kinase Slap/SrcK,
composed of SlapDeltaC fused to the SH2 linker kinase sequence of Src, was not
regulated in vivo. Furthermore, the Src SH3 domain is required for signaling
during mitogenesis and since Slap/SrcK behaved as a dominant negative in the PDGF
mitogenic response when microinjected into quiescent fibroblasts. We conclude
that Slap is a negative regulator of Src during mitogenesis involving both the
SH2 and the C terminus domains in a noncompetitive manner, but it does not
regulate all Src function due to specific SH3 binding substrates.
PMID- 10779330
TI - Bcl-3 expression promotes cell survival following interleukin-4 deprivation and
is controlled by AP1 and AP1-like transcription factors.
AB - We have analyzed the interleukin-4 (IL-4)-triggered mechanisms implicated in cell
survival and show here that IL-4 deprivation induces apoptotic cell death but
does not modulate Bcl-2 or Bcl-x expression. Since Bcl-x expression is
insufficient to ensure cell survival in the absence of IL-4, we speculate that
additional molecules replace the antiapoptotic role of Bcl-2 and Bcl-x in an
alternative IL-4-triggered pathway. Cell death is associated with Bcl-3
downregulation and Bcl-3 expression blocks IL-4 deprivation-induced apoptosis,
suggesting that Bcl-3 acts as a survival factor in the absence of growth factor.
To characterize the IL-4-induced regulation of murine Bcl-3 expression, we cloned
the promoter of this gene. Sequencing of the promoter showed no TATA box element
but did reveal binding sites for AP1, AP1-like, and SP1 transcription factors.
Retardation gels showed that IL-4 specifically induces AP1 and AP1-like binding
activity and that mutation of these binding sites abolishes the IL-4-induced Bcl
3 promoter activity, suggesting that these transcription factors are important in
Bcl-3 promoter transactivation. IL-4 deprivation induces downregulation of Jun
expression and upregulation of Fos expression, both of which are proteins
involved in the formation of AP1 and AP1-like transcription factors.
Overexpression of Jun family proteins transactivates the promoter and restores
Bcl-3 expression in the absence of IL-4 stimulation. Taken together, these data
describe a new biological role for Bcl-3 and define the regulatory pathway
implicated in Bcl-3 expression.
PMID- 10779331
TI - E2F4 and E2F1 have similar proliferative properties but different apoptotic and
oncogenic properties in vivo.
AB - Loss of retinoblastoma (Rb) tumor suppressor function, as occurs in many cancers,
leads to uncontrolled proliferation, an increased propensity to undergo
apoptosis, and tumorigenesis. Rb negatively regulates multiple E2F transcription
factors, but the role of the different E2F family members in manifesting the
cellular response to Rb inactivation is unclear. To study the effect of
deregulated E2F4 activity on cell growth control and tumorigenesis, transgenic
mouse lines expressing the E2F4 gene under the control of a keratin 5 (K5)
promoter were developed, and their phenotypes were compared to those of
previously generated K5 E2F1 transgenic mice. In contrast to what has been
observed in vitro, ectopically expressed E2F4 was found to localize to the
nucleus and induce proliferation to an extent similar to that induced by E2F1 in
transgenic tissue. Unlike E2F1, E2F4 does not induce apoptosis, and this
correlates with the differential abilities of these two E2F species to stimulate
p19(ARF) expression in vivo. To examine the role of E2F4 in tumor development,
the mouse skin two-stage carcinogenesis model was utilized. Unlike E2F1
transgenic mice, E2F4 transgenic mice developed skin tumors with a decreased
latency and increased incidence compared to those characteristics in wild-type
controls. These findings demonstrate that while the effects of E2F1 and E2F4 on
cell proliferation in vivo are similar, their apoptotic and oncogenic properties
are quite different.
PMID- 10779333
TI - SINE retroposons can be used in vivo as nucleation centers for de novo
methylation.
AB - SINEs (short interspersed elements) are an abundant class of transposable
elements found in a wide variety of eukaryotes. Using the genomic sequencing
technique, we observed that plant S1 SINE retroposons mainly integrate in
hypomethylated DNA regions and are targeted by methylases. Methylation can then
spread from the SINE into flanking genomic sequences, creating distal epigenetic
modifications. This methylation spreading is vectorially directed upstream or
downstream of the S1 element, suggesting that it could be facilitated when a
potentially good methylatable sequence is single stranded during DNA replication,
particularly when located on the lagging strand. Replication of a short
methylated DNA region could thus lead to the de novo methylation of upstream or
downstream adjacent sequences.
PMID- 10779332
TI - Repair of intermediate structures produced at DNA interstrand cross-links in
Saccharomyces cerevisiae.
AB - Bifunctional alkylating agents and other drugs which produce DNA interstrand
cross-links (ICLs) are among the most effective antitumor agents in clinical use.
In contrast to agents which produce bulky adducts on only one strand of the DNA,
the cellular mechanisms which act to eliminate DNA ICLs are still poorly
understood, although nucleotide excision repair is known to play a crucial role
in an early repair step. Using haploid Saccharomyces cerevisiae strains disrupted
for genes central to the recombination, nonhomologous end-joining (NHEJ), and
mutagenesis pathways, all these activities were found to be involved in the
repair of nitrogen mustard (mechlorethamine)- and cisplatin-induced DNA ICLs, but
the particular pathway employed is cell cycle dependent. Examination of whole
chromosomes from treated cells using contour-clamped homogenous electric field
electrophoresis revealed the intermediate in the repair of ICLs in dividing
cells, which are mostly in S phase, to be double-strand breaks (DSBs). The origin
of these breaks is not clear since they were still efficiently induced in
nucleotide excision and base excision repair-deficient, mismatch repair
defective, rad27 and mre11 disruptant strains. In replicating cells, RAD52
dependent recombination and NHEJ both act to repair the DSBs. In contrast, few
DSBs were observed in quiescent cells, and recombination therefore seems
dispensable for repair. The activity of the Rev3 protein (DNA polymerase zeta) is
apparently more important for the processing of intermediates in stationary-phase
cells, since rev3 disruptants were more sensitive in this phase than in the
exponential growth phase.
PMID- 10779334
TI - Deficient gene expression in protein kinase inhibitor alpha Null mutant mice.
AB - Protein kinase inhibitor (PKI) is a potent endogenous inhibitor of the cyclic AMP
(cAMP)-dependent protein kinase (PKA). It functions by binding the free catalytic
(C) subunit with a high affinity and is also known to export nuclear C subunit to
the cytoplasm. The significance of these actions with respect to PKI's
physiological role is not well understood. To address this, we have generated by
homologous recombination mutant mice that are deficient in PKIalpha, one of the
three isoforms of PKI. The mice completely lack PKI activity in skeletal muscle
and, surprisingly, show decreased basal and isoproterenol-induced gene expression
in muscle. Further examination revealed reduced levels of the phosphorylated
(active) form of the transcription factor CREB (cAMP response element binding
protein) in the knockouts. This phenomenon stems, at least in part, from lower
basal PKA activity levels in the mutants, arising from a compensatory increase in
the level of the RIalpha subunit of PKA. The deficit in gene induction, however,
is not easily explained by current models of PKI function and suggests that PKI
may play an as yet undescribed role in PKA signaling.
PMID- 10779335
TI - Long palindromic sequences induce double-strand breaks during meiosis in yeast.
AB - Inverted-repeated or palindromic sequences have been found to occur in both
prokaryotic and eukaryotic genomes. Such repeated sequences are usually short and
present at several functionally important regions in the genome. However, long
palindromic sequences are rare and are a major source of genomic instability. The
palindrome-mediated genomic instability is believed to be due to cruciform or
hairpin formation and subsequent cleavage of this structure by structure-specific
nucleases. Here we present both genetic and physical evidence that long
palindromic sequences (>50 bp) generate double-strand breaks (DSBs) at a high
frequency during meiosis in the yeast Saccharomyces cerevisiae. The palindrome
mediated DSB formation depends on the primary sequence of the inverted repeat and
the location and length of the repeated units. The DSB formation at the
palindrome requires all of the gene products that are known to be responsible for
DSB formation at the normal meiosis-specific sites. Since DSBs are initiators of
nearly all meiotic recombination events, most of the palindrome-induced breaks
appear to be repaired by homologous recombination. Our results suggest that short
palindromic sequences are highly stable in vivo. In contrast, long palindromic
sequences make the genome unstable by inducing DSBs and such sequences are
usually removed from the genome by homologous recombination events.
PMID- 10779336
TI - Fission yeast Eso1p is required for establishing sister chromatid cohesion during
S phase.
AB - Sister chromatid cohesion is essential for cell viability. We have isolated a
novel temperature-sensitive lethal mutant named eso1-H17 that displays spindle
assembly checkpoint-dependent mitotic delay and abnormal chromosome segregation.
At the permissive temperature, the eso1-H17 mutant shows mild sensitivity to UV
irradiation and DNA-damaging chemicals. At the nonpermissive temperature, the
mutant is arrested in M phase with a viability loss due to a failure to establish
sister chromatid cohesion during S phase. The lethal M-phase arrest phenotype,
however, is suppressed by inactivation of a spindle checkpoint. The eso1(+) gene
is not essential for the onset and progression of DNA replication but has
remarkable genetic interactions with those genes regulating the G(1)-S transition
and DNA replication. The N-terminal two-thirds of Eso1p is highly homologous to
DNA polymerase eta of budding yeast and humans, and the C-terminal one-third is
homologous to budding yeast Eco1p (also called Ctf7p), which is required for the
establishment of sister chromatid cohesion. Deletion analysis and determination
of the mutation site reveal that the function of the Eco1p/Ctf7p-homologous
domain is necessary and sufficient for sister chromatid cohesion. On the other
hand, deletion of the DNA polymerase eta domain in Eso1p increases sensitivity to
UV irradiation. These results indicate that Eso1p plays a dual role during DNA
replication. The C-terminal region acts to establish sister chromatid cohesion,
and the N-terminal region presumably catalyzes translesion DNA synthesis when
template DNA contains lesions that block regular DNA replication.
PMID- 10779338
TI - Enhanced transformation by a plasma membrane-associated met oncoprotein:
activation of a phosphoinositide 3'-kinase-dependent autocrine loop involving
hyaluronic acid and CD44.
AB - A Met-hepatocyte growth factor receptor oncoprotein, Tpr-Met, generated by
chromosomal rearrangement, fuses a protein dimerization motif with the
cytoplasmic domain of the Met receptor, producing a cytosolic, constitutively
activated tyrosine kinase. Although both the Met receptor and the Tpr-Met
oncoprotein associate with the same substrates, activating mutations of the Met
receptor in hereditary papillary renal carcinomas have different signaling
requirements for transformation than Tpr-Met. This suggests differential
activation of membrane-localized pathways by oncogenic forms of the membrane
bound Met receptor but not by the cytoplasmic Tpr-Met oncoprotein. To establish
which pathways might be differentially regulated, we have localized the
constitutively activated Tpr-Met oncoprotein to the membrane using the c-src
myristoylation signal. Membrane localization enhances cellular transformation,
focus formation, and anchorage-independent growth and induces tumors with a
distinct myxoid phenotype. This correlates with the induction of hyaluronic acid
(HA) and the presence of a distinct form of its receptor, CD44. A pharmacological
inhibitor of phosphoinositide 3' kinase (PI3'K), inhibits the production of HA,
and conversely, an activated, plasma membrane-targeted form of PI3'K is
sufficient to enhance HA production. Furthermore, the multisubstrate adapter
protein Gab-1, which couples the Met receptor with PI3'K, enhances Met receptor
dependent HA synthesis in a PI3'K-dependent manner. These results provide a
positive link to a role for HA and CD44 in Met receptor-mediated oncogenesis and
implicate PI3'K in these events.
PMID- 10779337
TI - Molecular interactions involved in the transactivation of the human T-cell
leukemia virus type 1 promoter mediated by Tax and CREB-2 (ATF-4).
AB - The human T-cell leukemia virus type 1 (HTLV-1) Tax protein activates viral
transcription through three 21-bp repeats located in the U3 region of the HTLV-1
long terminal repeat and called Tax-responsive elements (TxREs). Each TxRE
contains nucleotide sequences corresponding to imperfect cyclic AMP response
elements (CRE). In this study, we demonstrate that the bZIP transcriptional
factor CREB-2 is able to bind in vitro to the TxREs and that CREB-2 binding to
each of the 21-bp motifs is enhanced by Tax. We also demonstrate that Tax can
weakly interact with CREB-2 bound to a cellular palindromic CRE motif such as
that found in the somatostatin promoter. Mutagenesis of Tax and CREB-2
demonstrates that both N- and C-terminal domains of Tax and the C-terminal region
of CREB-2 are required for direct interaction between the two proteins. In
addition, the Tax mutant M47, defective for HTLV-1 activation, is unable to form
in vitro a ternary complex with CREB-2 and TxRE. In agreement with recent results
suggesting that Tax can recruit the coactivator CREB-binding protein (CBP) on the
HTLV-1 promoter, we provide evidence that Tax, CREB-2, and CBP are capable of
cooperating to stimulate viral transcription. Taken together, our data highlight
the major role played by CREB-2 in Tax-mediated transactivation.
PMID- 10779339
TI - Involvement of Myc activity in a G(1)/S-promoting mechanism parallel to the
pRb/E2F pathway.
AB - The retinoblastoma protein (pRb)/E2F pathway regulates commitment of mammalian
cells to replicate DNA. On the other hand, mitogen-stimulated cells deprived of
E2F activity can still maintain physiologically relevant levels of cyclin E
dependent kinase activity and gradually enter S phase, suggesting the existence
of a DNA synthesis-inducing mechanism parallel to the pRb/E2F axis. Here we show
that regulatable ectopic expression of cyclin E or transcriptionally active Myc
can rapidly induce DNA synthesis in U2OS-derived cell lines whose E2F activity is
blocked by a constitutively active pRb (pRbDeltacdk) mutant. The effect of Myc is
associated with Cdc25A phosphatase and cyclin E-CDK2 kinase activation and
abolished by antagonizing Myc activity with the dominant-negative (dn) MadMyc
chimera. Moreover, while abrogation of either endogenous E2F or Myc activity only
delays and lowers DNA synthesis in synchronized U2OS cells or rat diploid
fibroblasts, concomitant neutralization of both abolishes it. Whereas ectopic Myc
and E2F1 rescue the G(1)/S delay caused by pRbDeltacdk (or dnDP1) and MadMyc,
respectively, cyclin E or Cdc25A can restore DNA replication even in cells
concomitantly exposed to pRbDeltacdk and MadMyc. However, coexpression of dnCDK2
neutralizes all of these rescuing effects. Finally, proper transcription of
cyclin E and Cdc25A at the G(1)/S transition requires both Myc and E2F
activities, and subthreshold levels of ectopic cyclin E and Cdc25A
synergistically restore DNA synthesis in cells with silenced Myc and E2F
activities. These results suggest that Myc controls a G(1)/S-promoting mechanism
regulating cyclin E-CDK2 in parallel to the "classical" pRb/E2F pathway.
PMID- 10779340
TI - Facilitated nucleocytoplasmic shuttling of the Ran binding protein RanBP1.
AB - The Ran binding protein RanBP1 is localized to the cytosol of interphase cells. A
leucine-rich nuclear export signal (NES) near the C terminus of RanBP1 is
essential to maintain this distribution. We now show that RanBP1 accumulates in
nuclei of cells treated with the export inhibitor, leptomycin B, and collapse of
the nucleocytoplasmic Ran:GTP gradient leads to equilibration of RanBP1 across
the nuclear envelope. Low temperature prevents nuclear accumulation of RanBP1,
suggesting that import does not occur via simple diffusion. Glutathione S
transferase (GST)-RanBP1(1-161), which lacks the NES, accumulates in the nucleus
after cytoplasmic microinjection. In permeabilized cells, nuclear accumulation of
GST-RanBP1(1-161) requires nuclear Ran:GTP but is not inhibited by a dominant
interfering G19V mutant of Ran. Nuclear accumulation is enhanced by addition of
exogenous karyopherins/importins or RCC1, both of which also enhance nuclear Ran
accumulation. Import correlates with Ran concentration. Remarkably, an E37K
mutant of RanBP1 does not import into the nuclei under any conditions tested
despite the fact that it can form a ternary complex with Ran and importin beta.
These data indicate that RanBP1 translocates through the pores by an active,
nonclassical mechanism and requires Ran:GTP for nuclear accumulation. Shuttling
of RanBP1 may function to clear nuclear pores of Ran:GTP, to prevent premature
release of import cargo from transport receptors.
PMID- 10779341
TI - Evidence for the involvement of nucleotide excision repair in the removal of
abasic sites in yeast.
AB - In eukaryotes, DNA damage induced by ultraviolet light and other agents which
distort the helix is removed by nucleotide excision repair (NER) in a fragment
approximately 25 to 30 nucleotides long. In humans, a deficiency in NER causes
xeroderma pigmentosum (XP), characterized by extreme sensitivity to sunlight and
a high incidence of skin cancers. Abasic (AP) sites are formed in DNA as a result
of spontaneous base loss and from the action of DNA glycosylases involved in base
excision repair. In Saccharomyces cerevisiae, AP sites are removed via the action
of two class II AP endonucleases, Apn1 and Apn2. Here, we provide evidence for
the involvement of NER in the removal of AP sites and show that NER competes with
Apn1 and Apn2 in this repair process. Inactivation of NER in the apn1Delta or
apn1Delta apn2Delta strain enhances sensitivity to the monofunctional alkylating
agent methyl methanesulfonate and leads to further impairment in the cellular
ability to remove AP sites. A deficiency in the repair of AP sites may contribute
to the internal cancers and progressive neurodegeneration that occur in XP
patients.
PMID- 10779342
TI - Retinoblastoma protein enhances the fidelity of chromosome segregation mediated
by hsHec1p.
AB - Retinoblastoma protein (Rb) plays important roles in cell cycle progression and
cellular differentiation. It may also participate in M phase events, although
heretofore only circumstantial evidence has suggested such involvement. Here we
show that Rb interacts, through an IxCxE motif and specifically during G(2)/M
phase, with hsHec1p, a protein essential for proper chromosome segregation. The
interaction between Rb and hsHec1p was reconstituted in a yeast strain in which
human hsHEC1 rescues the null mutation of scHEC1. Expression of Rb reduced
chromosome segregation errors fivefold in yeast cells sustained by a temperature
sensitive (ts) hshec1-113 allele and enhanced the ability of wild-type hsHec1p to
suppress lethality caused by a ts smc1 mutation. The interaction between Hec1p
and Smc1p was important for the specific DNA-binding activity of Smc1p.
Expression of Rb restored part of the inactivated function of hshec1-113p and
thereby increased the DNA-binding activity of Smc1p. Rb thus increased the
fidelity of chromosome segregation mediated by hsHec1p in a heterologous yeast
system.
PMID- 10779343
TI - Deletion of the PAT1 gene affects translation initiation and suppresses a PAB1
gene deletion in yeast.
AB - The yeast poly(A) binding protein Pab1p mediates the interactions between the 5'
cap structure and the 3' poly(A) tail of mRNA, whose structures synergistically
activate translation in vivo and in vitro. We found that deletion of the PAT1
(YCR077c) gene suppresses a PAB1 gene deletion and that Pat1p is required for the
normal initiation of translation. A fraction of Pat1p cosediments with free 40S
ribosomal subunits on sucrose gradients. The PAT1 gene is not essential for
viability, although disruption of the gene severely impairs translation
initiation in vivo, resulting in the accumulation of 80S ribosomes and in a large
decrease in the amounts of heavier polysomes. Pat1p contributes to the efficiency
of translation in a yeast cell-free system. However, the synergy between the cap
structure and the poly(A) tail is maintained in vitro in the absence of Pat1p.
Analysis of translation initiation intermediates on gradients indicates that
Pat1p acts at a step before or during the recruitment of the 40S ribosomal
subunit by the mRNA, a step which may be independent of that involving Pab1p. We
conclude that Pat1p is a new factor involved in protein synthesis and that Pat1p
might be required for promoting the formation or the stabilization of the
preinitiation translation complexes.
PMID- 10779344
TI - Binding of equine infectious anemia virus rev to an exon splicing enhancer
mediates alternative splicing and nuclear export of viral mRNAs.
AB - In addition to facilitating the nuclear export of incompletely spliced viral
mRNAs, equine infectious anemia virus (EIAV) Rev regulates alternative splicing
of the third exon of the tat/rev mRNA. In the presence of Rev, this exon of the
bicistronic RNA is skipped in a fraction of the spliced mRNAs. In this report,
the cis-acting requirements for exon 3 usage were correlated with sequences
necessary for Rev binding and transport of incompletely spliced RNA. The presence
of a purine-rich exon splicing enhancer (ESE) was required for exon 3
recognition, and the addition of Rev inhibited exon 3 splicing. Glutathione-S
transferase (GST)-Rev bound to probes containing the ESE, and mutation of GAA
repeats to GCA within the ESE inhibited both exon 3 recognition in RNA splicing
experiments and GST-Rev binding in vitro. These results suggest that Rev
regulates alternative splicing by binding at or near the ESE to block SR protein
ESE interactions. A 57-nucleotide sequence containing the ESE was sufficient to
mediate Rev-dependent nuclear export of incompletely spliced RNAs. Rev export
activity was significantly inhibited by mutation of the ESE or by trans
complementation with SF2/ASF. These results indicate that the ESE functions as a
Rev-responsive element and demonstrate that EIAV Rev mediates exon 3 exclusion
through protein-RNA interactions required for efficient export of incompletely
spliced viral RNAs.
PMID- 10779345
TI - Multiple mechanisms control phosphorylation of PHAS-I in five (S/T)P sites that
govern translational repression.
AB - Control of the translational repressor, PHAS-I, was investigated by expressing
proteins with Ser/Thr --> Ala mutations in the five (S/T)P phosphorylation sites.
Results of experiments with HEK293 cells reveal at least three levels of control.
At one extreme is nonregulated phosphorylation, exemplified by constitutive
phosphorylation of Ser82. At an intermediate level, amino acids and insulin
stimulate the phosphorylation of Thr36, Thr45, and Thr69 via mTOR-dependent
processes that function independently of other sites in PHAS-I. At the third
level, the extent of phosphorylation of one site modulates the phosphorylation of
another. This control is represented by Ser64 phosphorylation, which depends on
the phosphorylation of all three TP sites. The five sites have different
influences on the electrophoretic properties of PHAS-I and on the affinity of
PHAS-I for eukaryotic initiation factor 4E (eIF4E). Phosphorylation of Thr45 or
Ser64 results in the most dramatic decreases in eIF4E binding in vitro. However,
each of the sites influences mRNA translation, either directly by modulating the
binding affinity of PHAS-I and eIF4E or indirectly by affecting the
phosphorylation of other sites.
PMID- 10779346
TI - A novel 50-kilodalton fragment of host cell factor 1 (C1) in G(0) cells.
AB - Host cell factor 1 (HCF-1; also called C1) is a 230-kDa protein which is cleaved
posttranslationally into separate but associated N- and C-terminal polypeptides.
These polypeptides are components of the C1 complex, along with Oct-1 and the
viral protein VP16. The C1 complex is formed when herpes simplex virus (HSV)
infects a cell and is responsible for transcription of the HSV immediate-early
genes. A temperature-sensitive mutation in the N-terminal kelch domain of HCF-1
reversibly arrests cells in a G(0)-like state when grown at the nonpermissive
temperature, and the same domain interacts with VP16 in the formation of the C1
complex. The form of HCF-1 in primary G(0) cells was investigated by using
peripheral blood mononucleocytes and serum-arrested human primary fibroblasts. A
novel 50-kDa N-terminal fragment of HCF-1 encompassing the kelch domain was
identified in the cytoplasm of these cells. This fragment arises by proteolysis
of the full-length HCF-1 protein and is able to associate with VP16.
PMID- 10779347
TI - Essential role for the C-terminal noncatalytic region of SHIP in FcgammaRIIB1
mediated inhibitory signaling.
AB - The inositol phosphatase SHIP binds to the FcgammaRIIB1 receptor and plays a
critical role in FcgammaRIIB1-mediated inhibition of B-cell proliferation and
immunoglobulin synthesis. The molecular details of SHIP function are not fully
understood. While point mutations of the signature motifs in the inositol
phosphatase domain abolish SHIP's ability to inhibit calcium flux in B cells,
little is known about the function of the evolutionarily conserved, putative
noncatalytic regions of SHIP in vivo. In this study, through a systematic
mutagenesis approach, we identified the inositol phosphatase domain of SHIP
between amino acids 400 and 866. Through reconstitution of a SHIP-deficient B
cell line with wild-type and mutant forms of SHIP, we demonstrate that the
catalytic domain alone is not sufficient to mediate FcgammaRIIB1/SHIP-dependent
inhibition of B-cell receptor signaling. Expression of a truncation mutant of
SHIP that has intact phosphatase activity but lacks the last 190 amino acids
showed that the noncatalytic region in the C terminus is essential for inhibitory
signaling. Mutation of two tyrosines within this C-terminal region, previously
identified as important in binding to Shc, showed a reduced inhibition of calcium
flux. However, studies with an Shc-deficient B-cell line indicated that Shc-SHIP
complex formation is not required and that other proteins that bind these
tyrosines may be important in FcgammaRIIB1/SHIP-mediated calcium inhibition.
Interestingly, membrane targeting of SHIP lacking the C terminus is able to
restore this inhibition, suggesting a role for the C terminus in localization or
stabilization of SHIP interaction at the membrane. Taken together, these data
suggest that the noncatalytic carboxyl-terminal 190 amino acids of SHIP play a
critical role in SHIP function in B cells and may play a similar role in several
other receptor systems where SHIP functions as a negative regulator.
PMID- 10779348
TI - Role of oxidative phosphorylation in Bax toxicity.
AB - The Bcl-2-related protein Bax is toxic when expressed either in yeast or in
mammalian cells. Although the mechanism of this toxicity is unknown, it appears
to be similar in both cell types and dependent on the localization of Bax to the
outer mitochondrial membrane. To investigate the role of mitochondrial
respiration in Bax-mediated toxicity, a series of yeast mutant strains was
created, each carrying a disruption in either a component of the mitochondrial
electron transport chain, a component of the mitochondrial ATP synthesis
machinery, or a protein involved in mitochondrial adenine nucleotide exchange.
Bax toxicity was reduced in strains lacking the ability to perform oxidative
phosphorylation. In contrast, a respiratory-competent strain that lacked the
outer mitochondrial membrane Por1 protein showed increased sensitivity to Bax
expression. Deficiencies in other mitochondrial proteins did not affect Bax
toxicity as long as the ability to perform oxidative phosphorylation was
maintained. Characterization of Bax-induced toxicity in wild-type yeast
demonstrated a growth inhibition that preceded cell death. This growth inhibition
was associated with a decreased ability to carry out oxidative phosphorylation
following Bax induction. Furthermore, cells recovered following Bax-induced
growth arrest were enriched for a petite phenotype and were no longer able to
grow on a nonfermentable carbon source. These results suggest that Bax expression
leads to an impairment of mitochondrial respiration, inducing toxicity in cells
dependent on oxidative phosphorylation for survival. Furthermore, Bax toxicity is
enhanced in yeast deficient in the ability to exchange metabolites across the
outer mitochondrial membrane.
PMID- 10779349
TI - Phospholipase C is involved in kinetochore function in Saccharomyces cerevisiae.
AB - The budding yeast PLC1 gene encodes a homolog of the delta isoform of mammalian
phosphoinositide-specific phospholipase C. Here, we present evidence that Plc1p
associates with the kinetochore complex CBF3. This association is mediated
through interactions with two established kinetochore proteins, Ndc10p and Cep3p.
We show by chromatin immunoprecipitation experiments that Plc1p resides at
centromeric loci in vivo. Deletion of PLC1, as well as plc1 mutations which
abrogate the interaction of Plc1p with the CBF3 complex, results in a higher
frequency of minichromosome loss, nocodazole sensitivity, and mitotic delay.
Overexpression of Ndc10p suppresses the nocodazole sensitivity of plc1 mutants,
implying that the association of Plc1p with CBF3 is important for optimal
kinetochore function. Chromatin extracts from plc1Delta cells exhibit reduced
microtubule binding to minichromosomes. These results suggest that Plc1p
associates with kinetochores and regulates some aspect of kinetochore function
and demonstrate an intranuclear function of phospholipase C in eukaryotic cells.
PMID- 10779350
TI - Roles for non-TATA core promoter sequences in transcription and factor binding.
AB - Sequence blocks within the core region were swapped among RNA polymerase II
promoters to explore effects on transcription in vitro. The pair of blocks
flanking TATA strongly influenced general transcription, with an additional
effect on promoter activation. These flanking elements induced a change in the
ratio of activated to basal transcription, whereas swapping TATA and initiator
sequences only altered general transcription levels. Swapping the flanking blocks
influenced binding by general transcription factors TBP and TFIIB. The results
suggest that the architecture of the extended core sequence is important in
determining promoter-specific effects on both general transcription levels and
the tightness of regulation.
PMID- 10779352
TI - Identification of a novel E2F3 product suggests a mechanism for determining
specificity of repression by Rb proteins.
AB - The tumor suppressor function of Rb is intimately related to its ability to
interact with E2F and repress the transcription of E2F target genes. Here we
describe a novel E2F product that specifically interacts with Rb in quiescent
cells. This novel E2F, which we term E2F3b, is encoded by a unique mRNA
transcribed from an intronic promoter within the E2F3 locus. The E2F3b RNA
differs from the previously characterized E2F3 RNA, which we now term E2F3a, by
the utilization of a unique coding exon. In contrast to the E2F3a product that is
tightly regulated by cell growth, the E2F3b product is expressed equivalently in
quiescent and proliferating cells. But, unlike the E2F4 and E2F5 proteins, which
are also expressed in quiescent cells and form complexes with the p130 protein,
the E2F3b protein associates with Rb and represents the predominant E2F-Rb
complex in quiescent cells. Thus, the previously described specificity of Rb
function as a transcriptional repressor in quiescent cells coincides with the
association of Rb with this novel E2F product.
PMID- 10779351
TI - UV-Induced stabilization of c-fos and other short-lived mRNAs.
AB - Irradiation of cells with short-wavelength ultraviolet light (UVC) changes the
program of gene expression, in part within less than 15 min. As one of the
immediate-early genes in response to UV, expression of the oncogene c-fos is
upregulated. This immediate induction is regulated at the transcriptional level
and is transient in character, due to the autocatalyzed shutoff of transcription
and the rapid turnover of c-fos mRNA. In an experiment analyzing the kinetics of
c-fos mRNA expression in murine fibroblasts irradiated with UVC, we found that,
in addition to the initial transient induction, c-fos mRNA accumulated in a
second wave starting at 4 to 5 h after irradiation, reaching a maximum at 8 h,
and persisting for several more hours. It was accompanied by an increase in Fos
protein synthesis. The second peak of c-fos RNA was caused by an UV dose
dependent increase in mRNA half-life from about 10 to 60 min. With similar
kinetics, the mRNAs of other UV target genes (i.e., the Kin17 gene, c-jun,
IkappaB, and c-myc) were stabilized (e.g., Kin17 RNA from 80 min to more than 8
h). The delayed response was not due to autocrine cytokine secretion with
subsequent autostimulation of the secreting cells or to UV-induced growth factor
receptor activation. Cells unable to repair UVC-induced DNA damage responded to
lower doses of UVC with an even greater accumulation of c-fos and Kin17 mRNAs
than repair-proficient wild-type cells, suggesting that a process in which a
repair protein is involved regulates mRNA stability. Although resembling the
induction of p53, a DNA damage-dependent increase in p53 was not a necessary
intermediate in the stabilization reaction, since cells derived from p53 knockout
mice showed the same pattern of c-fos and Kin17 mRNA accumulation as wild-type
cells. The data indicate that the signal flow induced by UV radiation addresses
not only protein stability (p53) and transcription but also RNA stability, a
hitherto-unrecognized level of UV-induced regulation.
PMID- 10779353
TI - Complex transcriptional regulatory mechanisms control expression of the E2F3
locus.
AB - E2F transcription activity has been shown to play a critical role in cell growth
control, regulating the expression of a variety of genes that encode proteins
important for the initiation of DNA replication and cell cycle regulation. We
have shown that the E2F3 locus encodes two protein products: the E2F3a product,
which is tightly regulated by cell growth, and the E2F3b product, which is
constitutively expressed throughout the cell cycle. To further explore the
mechanism controlling the expression of the two E2F3 gene products, we analyzed
the genomic sequences flanking the 5' region of E2F3a and E2F3b. We find that a
series of E2F binding sites confer negative control on the E2F3a promoter in
quiescent cells, similar to the control of the E2F1 and E2F2 promoters. In
addition, a group of E-box elements, which are Myc binding sites, confer
responsiveness to Myc and are necessary for full activation of the E2F3a promoter
in response to growth stimulation. Based on these results and past experiments,
it appears that the E2F1, E2F2, and E2F3a genes are similarly regulated by growth
stimulation, involving a combination of E2F-dependent negative control and Myc
mediated positive control. In contrast, the constitutive expression of the E2F3b
gene more closely reflects the control of expression of the E2F4 and E2F5 genes.
PMID- 10779355
TI - IkappaB kinase alpha (IKKalpha) regulation of IKKbeta kinase activity.
AB - Two related kinases, IkappaB kinase alpha (IKKalpha) and IKKbeta, phosphorylate
the IkappaB proteins, leading to their degradation and the subsequent activation
of gene expression by NF-kappaB. IKKbeta has a much higher level of kinase
activity for the IkappaB proteins than does IKKalpha and is more critical than
IKKalpha in modulating tumor necrosis factor alpha activation of the NF-kappaB
pathway. These results indicate an important role for IKKbeta in activating the
NF-kappaB pathway but leave open the question of the role of IKKalpha in
regulating this pathway. In the current study, we demonstrate that IKKalpha
directly phosphorylates IKKbeta. Moreover, IKKalpha either directly or indirectly
enhances IKKbeta kinase activity for IkappaBalpha. Finally, transfection studies
to analyze NF-kappaB-directed gene expression suggest that IKKalpha is upstream
of IKKbeta in activating the NF-kappaB pathway. These results indicate that
IKKalpha, in addition to its previously described ability to phosphorylate
IkappaBalpha, can increase the ability of IKKbeta to phosphorylate IkappaBalpha.
PMID- 10779354
TI - Overlapping expression of early B-cell factor and basic helix-loop-helix proteins
as a mechanism to dictate B-lineage-specific activity of the lambda5 promoter.
AB - The basic helix-loop-helix (bHLH) transcription factors are a large group of
proteins suggested to control key events in the development of B lymphocytes as
well as of other cellular lineages. To examine how bHLH proteins activate a B
lineage-specific promoter, I investigated the ability of E47, E12, Heb, E2-2, and
MyoD to activate the lambda5 surrogate light chain promoter. Comparison of the
functional capacity of the E2A-encoded E47 and E12 proteins indicated that even
though both were able to activate the lambda5 promoter and act in synergy with
early B-cell factor (EBF), E47 displayed a higher functional activity than E12.
An ability to act in synergy with EBF was also observed for Heb, E2-2, and MyoD,
suggesting that these factors were functionally redundant in this regard. Mapping
of functional domains in EBF and E47 revealed that the dimerization and DNA
binding domains mediated the synergistic activity. Electrophoretic mobility shift
assay analysis using the 5' part of the lambda5 promoter revealed formation of
template-dependent heteromeric complexes between EBF and E47, suggesting that the
synergistic mechanism involves cooperative binding to DNA. These findings propose
a unique molecular function for E47 and provide overlapping expression with EBF
as a molecular mechanism to direct B-cell-specific target gene activation by bHLH
proteins.
PMID- 10779356
TI - Distinct phosphoisoforms of the Xenopus Mcm4 protein regulate the function of the
Mcm complex.
AB - Initiation of DNA replication in eukaryotes requires the assembly of
prereplication complexes (pre-Rcs) at the origins of replication. The assembly
and function of the pre-Rcs appear to be controlled by phosphorylation events. In
this study we report the detailed characterization of the cell cycle
phosphorylation of one component of the Xenopus pre-Rcs, the Mcm protein complex.
We show that individual Mcm subunits are differentially phosphorylated during the
cell cycle. During mitosis, the Mcm4 subunit is hyperphosphorylated, while the
other subunits are not actively phosphorylated. The mitotic phosphorylation of
Mcm4 requires Cdc2-cyclin B and other unknown kinases. Following exit from
mitosis, the Mcm4 subunit of the cytosolic interphase complex undergoes
dephosphorylation, and the Mcm2, Mcm3, or Mcm6 subunits are then actively
phosphorylated by kinase(s) other than cyclin-dependent kinases (Cdks) or Cdc7.
The association of the Mcm complex with the pre-Rcs correlates with the formation
of a transient interphase complex. This complex contains an intermediately
phosphorylated Mcm4 subunit and is produced by partial dephosphorylation of the
mitotic hyperphosphorylated Mcm4 protein. Complete dephosphorylation of the Mcm4
subunit inactivates the Mcm complex and prevents its binding to the chromatin.
Once the Mcm complex is assembled on the chromatin the Mcm4 and the Mcm2 proteins
are the only subunits phosphorylated during the activation of the pre-Rcs. These
chromatin-associated phosphorylations require nuclear transport and are
independent of Cdk2-cyclin E. These results suggest that the changes in Mcm4
phosphorylation regulate pre-Rc assembly and the function of the pre-Rcs on the
chromatin.
PMID- 10779357
TI - Role of the mitochondrial Hsp70s, Ssc1 and Ssq1, in the maturation of Yfh1.
AB - The mitochondrial matrix of the yeast Saccharomyces cerevisiae contains two
molecular chaperones of the Hsp70 class, Ssc1 and Ssq1. We report that Ssc1 and
Ssq1 play sequential roles in the import and maturation of the yeast frataxin
homologue (Yfh1). In vitro, radiolabeled Yfh1 was not imported into ssc1-3 mutant
mitochondria, remaining in a protease-sensitive precursor form. As reported
earlier, the Yfh1 intermediate form was only slowly processed to the mature form
in Deltassq1 mitochondria (S. A. B. Knight, N. B. V. Sepuri, D. Pain, and A.
Dancis, J. Biol. Chem. 273:18389-18393, 1998). However, the intermediate form in
both wild-type and Deltassq1 mitochondria was entirely within the inner membrane,
as it was resistant to digestion with protease after disruption of the outer
membrane. Therefore, we conclude that Ssc1, which is present in mitochondria in
approximately a 1,000-fold excess over Ssq1, is required for Yfh1 import into the
matrix, while Ssq1 is necessary for the efficient processing of the intermediate
to the mature form in isolated mitochondria. However, the steady-state level of
mature Yfh1 in Deltassq1 mitochondria is approximately 75% of that found in wild
type mitochondria, indicating that this retardation in processing does not
dramatically affect cellular concentrations. Therefore, Ssq1 likely has roles in
addition to facilitating the processing of Yfh1. Twofold overexpression of Ssc1
partially suppresses the cold-sensitive growth phenotype of Deltassq1 cells, as
well as the accumulation of mitochondrial iron and the defects in Fe/S enzyme
activities normally found in Deltassq1 mitochondria. Deltassq1 mitochondria
containing twofold-more Ssc1 efficiently converted the intermediate form of Yfh1
to the mature form. This correlation between the observed processing defect and
suppression of in vivo phenotypes suggests that Ssc1 is able to carry out the
functions of Ssq1, but only when present in approximately a 2,000-fold excess
over normal levels of Ssq1.
PMID- 10779358
TI - ADP-ribosylation factor 6 regulates actin cytoskeleton remodeling in coordination
with Rac1 and RhoA.
AB - In this study, we have documented an essential role for ADP-ribosylation factor 6
(ARF6) in cell surface remodeling in response to physiological stimulus and in
the down regulation of stress fiber formation. We demonstrate that the G-protein
coupled receptor agonist bombesin triggers the redistribution of ARF6- and Rac1
containing endosomal vesicles to the cell surface. This membrane redistribution
was accompanied by cortical actin rearrangements and was inhibited by dominant
negative ARF6, implying that bombesin is a physiological trigger of ARF6
activation. Furthermore, these studies provide a new model for bombesin-induced
Rac1 activation that involves ARF6-regulated endosomal recycling. The bombesin
elicited translocation of vesicular ARF6 was mimicked by activated Galphaq and
was partially inhibited by expression of RGS2, which down regulates Gq function.
This suggests that Gq functions as an upstream regulator of ARF6 activation. The
ARF6-induced peripheral cytoskeletal rearrangements were accompanied by a
depletion of stress fibers. Moreover, cells expressing activated ARF6 resisted
the formation of stress fibers induced by lysophosphatidic acid. We show that the
ARF6-dependent inhibition of stress fiber formation was due to an inhibition of
RhoA activation and was overcome by expression of a constitutively active RhoA
mutant. The latter observations demonstrate that activation of ARF6 down
regulates Rho signaling. Our findings underscore the potential roles of ARF6,
Rac1, and RhoA in the coordinated regulation of cytoskeletal remodeling.
PMID- 10779359
TI - Role of Gab1 in heart, placenta, and skin development and growth factor- and
cytokine-induced extracellular signal-regulated kinase mitogen-activated protein
kinase activation.
AB - Gab1 is a member of the Gab/DOS (Daughter of Sevenless) family of adapter
molecules, which contain a pleckstrin homology (PH) domain and potential binding
sites for SH2 and SH3 domains. Gab1 is tyrosine phosphorylated upon stimulation
of various cytokines, growth factors, and antigen receptors in cell lines and
interacts with signaling molecules, such as SHP-2 and phosphatidylinositol 3
kinase, although its biological roles have not yet been established. To reveal
the functions of Gab1 in vivo, we generated mice lacking Gab1 by gene targeting.
Gab1-deficient embryos died in utero and displayed developmental defects in the
heart, placenta, and skin, which were similar to phenotypes observed in mice
lacking signals of the hepatocyte growth factor/scatter factor, platelet-derived
growth factor, and epidermal growth factor pathways. Consistent with these
observations, extracellular signal-regulated kinase mitogen-activated protein
(ERK MAP) kinases were activated at much lower levels in cells from Gab1
deficient embryos in response to these growth factors or to stimulation of the
cytokine receptor gp130. These results indicate that Gab1 is a common player in a
broad range of growth factor and cytokine signaling pathways linking ERK MAP
kinase activation.
PMID- 10779360
TI - p53-mediated DNA repair responses to UV radiation: studies of mouse cells lacking
p53, p21, and/or gadd45 genes.
AB - Human cells lacking functional p53 exhibit a partial deficiency in nucleotide
excision repair (NER), the pathway for repair of UV-induced DNA damage. The
global genomic repair (GGR) subpathway of NER, but not transcription-coupled
repair (TCR), is mainly affected by p53 loss or inactivation. We have utilized
mouse embryo fibroblasts (MEFs) lacking p53 genes or downstream effector genes of
the p53 pathway, gadd45 (Gadd45a) or p21 (Cdkn1a), as well as MEFs lacking both
gadd45 and p21 genes to address the potential contribution of these downstream
effectors to p53-associated DNA repair. Loss of p53 or gadd45 had a pronounced
effect on GGR, while p21 loss had only a marginal effect, determined by
measurements of repair synthesis (unscheduled DNA synthesis), by immunoassays to
detect removal of UV photoproducts from genomic DNA, and by assays determining
strand-specific removal of CPDs from the mouse dhfr gene. Taken together, the
evidence suggests a role for Gadd45, but relatively little role for p21, in DNA
repair responses to UV radiation. Recent evidence suggests that Gadd45 binds to
UV-damaged chromatin and may affect lesion accessibility. MEFs lacking p53 or
gadd45 genes exhibited decreased colony-forming ability after UV radiation and
cisplatin compared to wild-type MEFs, indicating their sensitivity to DNA damage.
We provide evidence that Gadd45 affects chromatin remodelling of templates
concurrent with DNA repair, thus indicating that Gadd45 may participate in the
coupling between chromatin assembly and DNA repair.
PMID- 10779361
TI - Mutagenesis of the pRB pocket reveals that cell cycle arrest functions are
separable from binding to viral oncoproteins.
AB - The pocket domain of pRB is required for pRB to arrest the cell cycle. This
domain was originally defined as the region of the protein that is necessary and
sufficient for pRB's interaction with adenovirus E1A and simian virus s40 large T
antigen. These oncoproteins, and other pRB-binding proteins that are encoded by a
variety of plant and animal viruses, use a conserved LXCXE motif to interact with
pRB. Similar sequences have been identified in multiple cellular pRB-binding
proteins, suggesting that the viruses have evolved to target a highly conserved
binding site of pRB that is critical for its function. Here we have constructed a
panel of pRB mutants in which conserved amino acids that are predicted to make
close contacts with an LXCXE peptide were altered. Despite the conservation of
the LXCXE binding site throughout evolution, pRB mutants that lack this site are
able to induce a cell cycle arrest in a pRB-deficient tumor cell line. This G(1)
arrest is overcome by cyclin D-cdk4 complexes but is resistant to inactivation by
E7. Consequently, mutants lacking the LXCXE binding site were able to induce a
G(1) arrest in HeLa cells despite the expression of HPV-18 E7. pRB mutants
lacking the LXCXE binding site are defective in binding to adenovirus E1A and
human papillomavirus type 16 E7 protein but exhibit wild-type binding to E2F or
DP, and they retain the ability to interact with CtIP and HDAC1, two
transcriptional corepressors that contain LXCXE-like sequences. Consistent with
these observations, the pRB mutants are able to actively repress transcription.
These observations suggest that viral oncoproteins depend on the LXCXE-binding
site of pRB for interaction to a far greater extent than cellular proteins that
are critical for cell cycle arrest or transcriptional repression. Mutation of
this binding site allows pRB to function as a cell cycle regulator while being
resistant to inactivation by viral oncoproteins.
PMID- 10779363
TI - Characterization of growth-differentiation factor 15, a transforming growth
factor beta superfamily member induced following liver injury.
AB - We have identified a new murine transforming growth factor beta superfamily
member, growth-differentiation factor 15 (Gdf15), that is expressed at highest
levels in adult liver. As determined by Northern analysis, the expression of
Gdf15 in liver was rapidly and dramatically up-regulated following various
surgical and chemical treatments that cause acute liver injury and regeneration.
In situ hybridization analysis revealed distinct patterns of Gdf15 mRNA
localization that appeared to reflect the known patterns of hepatocyte injury in
each experimental treatment. In addition, treatment of two hepatocyte-like cell
lines with either carbon tetrachloride or heat shock induced Gdf15 mRNA
expression, indicating that direct cellular injury can induce Gdf15 expression in
the absence of other cell types, such as inflammatory cells. In order to
investigate the potential functions of Gdf15, we created Gdf15 null mice by gene
targeting. Homozygous null mice were viable and fertile. Despite the dramatic
regulation of Gdf15 expression observed in the partial-hepatectomy and carbon
tetrachloride injury models, we found no differences in the injury responses
between homozygous null mutants and wild-type mice. Our findings suggest either
that Gdf15 does not have a regulatory role in liver injury and regeneration or
that Gdf15 function within the liver is redundant with that of other signaling
molecules.
PMID- 10779362
TI - Structure-function analysis of SUV39H1 reveals a dominant role in heterochromatin
organization, chromosome segregation, and mitotic progression.
AB - SUV39H1, a human homologue of the Drosophila position effect variegation modifier
Su(var)3-9 and of the Schizosaccharomyces pombe silencing factor clr4, encodes a
novel heterochromatic protein that transiently accumulates at centromeric
positions during mitosis. Using a detailed structure-function analysis of SUV39H1
mutant proteins in transfected cells, we now show that deregulated SUV39H1
interferes at multiple levels with mammalian higher-order chromatin organization.
First, forced expression of full-length SUV39H1 (412 amino acids) redistributes
endogenous M31 (HP1beta) and induces abundant associations with inter- and
metaphase chromatin. These properties depend on the C-terminal SET domain,
although the major portion of the SUV39H1 protein (amino acids 89 to 412) does
not display affinity for nuclear chromatin. By contrast, the M31 interaction
surface, which was mapped to the first 44 N-terminal amino acids, together with
the immediately adjacent chromo domain, directs specific accumulation at
heterochromatin. Second, cells overexpressing full-length SUV39H1 display severe
defects in mitotic progression and chromosome segregation. Surprisingly, whereas
localization of centromere proteins is unaltered, the focal, G(2)-specific
distribution of phosphorylated histone H3 at serine 10 (phosH3) is dispersed in
these cells. This phosH3 shift is not observed with C-terminally truncated mutant
SUV39H1 proteins or with deregulated M31. Together, our data reveal a dominant
role(s) for the SET domain of SUV39H1 in the distribution of prominent
heterochromatic proteins and suggest a possible link between a chromosomal
SU(VAR) protein and histone H3.
PMID- 10779364
TI - Inhibition of HIV infection by bicyclams, highly potent and specific CXCR4
antagonists.
AB - The bicyclams represent a new entity of low-molecular weight molecules that
inhibit human immunodeficiency virus (HIV) infection through a specific blockade
of CXCR4 (fusin), the receptor for the CXC chemokine SDF-1 (soluble-derived
factor), which is also used as coreceptor by T-lymphotropic HIV strains to enter
their target cells. The bicyclam AMD3100 or 1,1'-[1,4-phenylenebis(methylene)]
bis-1,4, 8,11-tetraazacyclotetradecane octahydrochloride dihydrate, is able to
block the CXCR4 receptor and to inhibit HIV replication at nanomolar
concentrations while not being toxic to the host cells at 100,000-fold higher
concentrations. It is the most specific and most potent CXCR4 antagonist that has
been described to date.
PMID- 10779365
TI - The guanine nucleotide exchange factor RasGRP is a high -affinity target for
diacylglycerol and phorbol esters.
AB - RasGRP is a recently described guanine nucleotide exchange factor (GEF) that
possesses a single C1 domain homologous to that of protein kinase C (PKC). The
phorbol ester [(3)H]phorbol 12, 13-dibutyrate ([(3)H]PDBu) bound to this C1
domain (C1-RasGRP) with a dissociation constant of 0.58 +/- 0.08 nM, similar to
that observed previously for PKC. Likewise, the potent PKC activator bryostatin
1, a compound currently in clinical trials, showed high affinity binding for C1
RasGRP. Structure activity analysis using several phorbol ester analogs showed
both similarities and differences in ligand selectivity compared with PKC; the
differences were comparable in magnitude to those between different PKC isoforms.
Similarly, the potency of the PKC inhibitor calphostin C to inhibit [(3)H]PDBu
binding to C1-RasGRP was similar to that observed for PKC. In contrast to the
relative similarities in ligand recognition, the lipid cofactor requirements
differed between RasGRP and PKC. The C1 domain plus the EF-hand motif of RasGRP
(C1EF-RasGRP) was markedly less dependent on acidic phospholipids than was
PKCalpha. The differences in lipid requirements were reflected in differential
ligand selectivity under conditions of limiting lipid. Despite the presence of
twin EF-hand like motifs, calcium did not affect the binding of [(3)H]PDBu to
C1EF-RasGRP. We conclude that RasGRP is a high affinity receptor for phorbol
esters and diacylglycerol. RasGRP thus provides a direct link between
diacylglycerol generation or phorbol ester/bryostatin treatment and Ras
activation.
PMID- 10779366
TI - Regulation of recombinant gamma-aminobutyric acid (GABA)(A) and GABA(C) receptors
by protein kinase C.
AB - Activation of protein kinase C (PKC) by phorbol 12-myristate 13-acetate induced a
continuous decrease in the gamma-aminobutyric acid (GABA)-activated current
amplitude from recombinant GABA receptors (formed by rho1 or alphabetagamma
subunits) expressed in Xenopus oocytes. This decline was due to internalization
of receptors from the plasma membrane as confirmed by a decrease in surface
fluorescence with green fluorescence protein-tagged receptors as well as a
concomitant decrease in surface [(3)H]GABA binding. PMA specifically caused
internalization of GABA receptors, but not neuronal acetylcholine receptors
(alpha(7) or alpha(4)beta(2)), indicating the internalization was not a general,
nonspecific phenomenon. Mutation of rho1 PKC phosphorylation sites, identified by
in vitro phosphorylation, did not prevent GABA receptor internalization, nor did
coexpression of the rho1 M3-M4 intracellular loop along with rho1 GABA receptors.
It is likely that PKC-mediated phosphorylation of other proteins, rather than
rho1 itself, was required for the internalization. Both rho1 and alphabetagamma
receptors did not degrade after phorbol 12-myristate 13-acetate-induced
internalization, but returned to the membrane surface within 24 h. These data
suggest internalized receptors can exist in an intracellular compartment that can
be delivered back to the plasma membrane. Thus, by regulating GABA receptor
surface expression, PKC may play a key role in the regulation of GABA-mediated
inhibition.
PMID- 10779367
TI - Up-regulation of airway smooth muscle histamine H(1) receptor mRNA, protein, and
function by beta(2)-adrenoceptor activation.
AB - Histamine, released from activated mast cells, causes bronchoconstriction
mediated by H(1) receptors, whereas beta(2)-agonists are widely used for the
relief of bronchoconstriction. In this study, we examined the effects of the
beta(2)-adrenoceptor agonist, fenoterol, on the expression of H(1) receptors at
the mRNA and protein levels, and functional responses. Incubation of bovine
tracheal smooth muscle with fenoterol (10(-7) M) for 2 h increased H(1) receptor
mRNA (maximum approximately 190%). The number of H(1) receptors was increased
after 12 and 18 h without any change in binding affinity. In the contraction
experiments, the concentration-response curves for histamine-induced contraction
were shifted significantly to the left after 18-h exposure to fenoterol,
consistent with the increase in receptor number. The fenoterol-induced increase
in H(1) receptor mRNA was concentration-dependent and was abolished by
propranolol and ICI 118551, but not by CGP 20712A, indicating that fenoterol acts
via beta(2)-adrenoceptors. These effects were mimicked by other cAMP-elevating
agents forskolin and prostaglandin E(2), and by the stable cAMP analog 8-bromo
cAMP. Cycloheximide alone produced superinduction of H(1) receptor mRNA and
augmented the fenoterol-induced increase in H(1) receptor mRNA. Fenoterol
increased both the stability and the transcription rate of H(1) receptor mRNA.
Pretreatment with dexamethasone did not prevent fenoterol-induced up-regulation
of H(1) receptor mRNA. Thus, fenoterol increases the expression of airway smooth
muscle H(1) receptors via activation of the cAMP system through increased gene
transcription and mRNA stability. This mechanism may be involved in the adverse
responses encountered with the clinical use of short-acting beta(2)-agonists.
PMID- 10779368
TI - Stimulatory effects of delta-hexachlorocyclohexane on Ca(2+)-activated K(+)
currents in GH(3) lactotrophs.
AB - delta-Hexachlorocyclohexane (delta-HCH), a lipophilic neurodepressant agent, has
been shown to inhibit neurotransmitter release and stimulate ryanodine-sensitive
Ca(2+) channels. However, the effect of delta-HCH on neuronal activity remains
unclear, although it may enhance the gamma-aminobutyric acid-induced current. Its
effects on ionic currents were investigated in rat pituitary GH(3) cells and
human neuroblastoma IMR-32 cells. In GH(3) cells, delta-HCH increased the
amplitude of Ca(2+)-activated K(+) current (I(K(Ca))). delta-HCH (100 microM)
slightly inhibited the amplitude of voltage-dependent K(+) current. delta-HCH (30
microM) suppressed voltage-dependent L-type Ca(2+) current (I(Ca, L)), whereas
gamma-HCH (30 microM) had no effect on I(Ca, L). In the inside-out configuration,
delta-HCH applied intracellularly did not change the single channel conductance
of large conductance Ca(2+)-activated K(+) (BK(Ca)) channels; however, it did
increase the channel activity. The delta-HCH-mediated increase in the channel
activity is mainly mediated by its increase in the number of long-lived openings.
delta-HCH reversibly increased the activity of BK(Ca) channels in a concentration
dependent manner with an EC(50) value of 20 microM. delta-HCH also caused a left
shift in the midpoint for the voltage-dependent opening. In contrast, gamma-HCH
(30 microM) suppressed the activity of BK(Ca) channels. Under the current-clamp
mode, delta-HCH (30 microM) reduced the firing rate of spontaneous action
potentials; however, gamma-HCH (30 microM) increased it. In neuroblastoma IMR-32
cells, delta-HCH also increased the amplitude of I(K(Ca)) and stimulated the
activity of intermediate-conductance K(Ca) channels. This study provides evidence
that delta-HCH is an opener of K(Ca) channels. The effects of delta-HCH on these
channels may partially, if not entirely, be responsible for the underlying
cellular mechanisms by which delta-HCH affects neuronal or neuroendocrine
function.
PMID- 10779369
TI - Mutating the highly conserved second membrane-spanning region 9' leucine residue
in the alpha(1) or beta(1) subunit produces subunit-specific changes in the
function of human alpha(1)beta(1) gamma-aminobutyric Acid(A) receptors.
AB - The properties of the human alpha(1)beta(1) gamma-aminobutyric acid (GABA)(A)
receptors were investigated after mutation of a highly conserved leucine residue
at the 9' position in the second membrane-spanning region (TM2). The role of this
residue in alpha(1) and beta(1) subunits was examined by mutating the 9' leucine
to phenylalanine, tyrosine, or alanine. The mutations were in either the alpha(1)
subunit (alpha*beta), the beta(1) subunit (alphabeta*), or in both subunits
(alpha*beta*), and the receptors were expressed in Sf9 cells. Our results show
that the rate of desensitization is increased as the size and hydrophobicity of
the 9' residue in the alpha(1) subunit is increased: Y, F > L > A, T. Mutation of
L9' in only the beta(1) subunit (alphabeta*) to either phenylalanine or tyrosine
increased the EC(50) value for GABA at least 100 times, but the EC(50) was
unchanged in alphabeta* alanine mutants. In the 9' alpha(1) mutants (alpha*beta,
alpha*beta*) the GABA EC(50) was minimally affected. In alpha*beta and
alpha*beta*, but not alphabeta*, the peak currents evoked by millimolar
concentrations of GABA were greatly reduced. The reduction in currents could only
be partially accounted for by decreased expression of the receptors These
findings suggest different roles for the two types of subunits in GABA activation
and later desensitization of alpha(1)beta(1) receptors. In addition, an increase
in the resting membrane conductance was recorded in alanine but not in
phenylalanine and tyrosine mutants, indicating that the side chain size at the 9'
position is a major determinant of current flow in the closed conformation.
PMID- 10779370
TI - Importance of valine at position 152 for the substrate transport and 2beta
carbomethoxy-3beta-(4-fluorophenyl)tropane binding of dopamine transporter.
AB - Human and bovine dopamine transporters (DAT) demonstrate discrete functional
differences in dopamine (DA), 1-methyl-4-phenylpyridium (MPP(+)) transport, and
cocaine analog binding. In a previous study, the functional analyses on the
chimeras of human and bovine DAT have revealed that the region from residues 133
through 186 (encompassing the third transmembrane domain) is responsible for the
substrate transport and cocaine analog binding. The present study has been
carried out to determine the specific amino acid(s) conferring DAT functions by
interchanging the amino acid residues in the corresponding region between human
and bovine DAT. As described previously, the DA, MPP(+) transport, and 2beta
carbomethoxy-3beta-(4-fluorophenyl)tropane (CFT) binding almost disappeared in
chimera hb3 in which the region from residues 133 through 186 of bovine DAT was
substituted into human DAT. Replacement of isoleucine, residue 152 of chimera hb3
(bovine DAT sequence), with valine, the human DAT residue at the identical
position, remarkably restored the substrate transport and CFT binding to 76% to
98% of the human DAT values. Similarly, substitution of isoleucine for valine at
position 152 in the human DAT reduced the substrate transport and CFT binding by
57% to 97%. Among other amino acids tested at position 152 of the chimera hb3,
only alanine resulted in small but significant increases in the DAT functions
ranging from 16 to 34%. Thus, valine at position 152 plays a crucial role for
molecular mechanisms underlying the interactions of DA, MPP(+), and CFT with
human DAT.
PMID- 10779371
TI - The effect of mutations in the DRY motif on the constitutive activity and
structural instability of the histamine H(2) receptor.
AB - In previous studies we showed that the wild-type histamine H(2) receptor stably
expressed in Chinese hamster ovary cells is constitutively active. Because
constitutive activity of the H(2) receptor is already found at low expression
levels (300 fmol/mg protein) this receptor is a relatively unique member of the G
protein-coupled receptor (GPCR) family and a useful tool for studying GPCR
activation. In this study the role of the highly conserved DRY motif in
activation of the H(2) receptor was investigated. Mutation of the aspartate 115
residue in this motif resulted in H(2) receptors with high constitutive activity,
increased agonist affinity, and increased signaling properties. In addition, the
mutant receptors were shown to be highly structurally instable. Mutation of the
arginine 116 residue in the DRY motif resulted also in a highly structurally
instable receptor; expression of the receptor could only be detected after
stabilization with either an agonist or inverse agonist. Moreover, the agonist
affinity at the Arg-116 mutant receptors was increased, whereas the signal
transduction properties of these receptors were decreased. We conclude that the
Arg-116 mutant receptors can adopt an active conformation but have a decreased
ability to couple to or activate the G(s)-protein. This study examines the
pivotal role of the aspartate and arginine residues of the DRY motif in GPCR
function. Disruption of receptor stabilizing constraints by mutation in the DRY
motif leads to the formation of active GPCR conformations, but concomitantly to
GPCR instability.
PMID- 10779372
TI - Mechanism-based inactivation of human dihydropyrimidine dehydrogenase by (E)-5-(2
bromovinyl)uracil in the presence of NADPH.
AB - Purified recombinant human dihydropyrimidine dehydrogenase (hDPD) was incubated
with (14)C-labeled (E)-5-(2-bromovinyl)uracil ([(14)C]BVU) in the presence of
NADPH to investigate a possible mechanism in the 18 patient deaths caused by
interactions of 5-fluorouracil prodrugs with the new oral antiviral drug,
sorivudine. BVU is formed from sorivudine by gut flora and absorbed through
intestinal membrane. hDPD, a rate-limiting enzyme for the catabolism of 5
fluorouracil and endogenous pyrimidines in the human, was NADPH dependently
radiolabeled and inactivated by [(14)C]BVU. Two radioactive tryptic fragments, I
and II, isolated from radiolabeled hDPD were found by complete amino acid
sequencing to originate from a common regional amino acid sequence located at
positions 656 (Lys) to 678 (Arg) for I and positions 657 (Ser) to 678 (Arg) for
II. However, only Cys(671), which should be present in the peptides, was not
identified by amino acid sequencing. Mass spectrometric analysis of the tryptic
fragments indicated that the sulfhydryl group of Cys(671) in the hDPD was
modified with 5, 6-dihydro-5-(2-bromoethylydenyl)uracil (BEDU), a putative allyl
bromide type of reactive molecule, to form a sulfide bond with loss of hydrogen
bromide. The Cys(671) sulfide bearing the debrominated BEDU had a 5,6
dihydrouracil ring highly strained by the exocyclic double bond at the 5
position, so that it underwent facile hydrolytic ring fission with alkali and
heated acid treatments. A new proposal is also made for the amino acid sequence
of the pyrimidine-binding domain, including Cys(671), of DPD in the human and
other species.
PMID- 10779373
TI - The neuroprotective agent riluzole activates the two P domain K(+) channels TREK
1 and TRAAK.
AB - Riluzole (RP 54274) is a potent neuroprotective agent with anticonvulsant,
sedative, and anti-ischemic properties. It is currently used in the treatment of
amyotrophic lateral sclerosis. This article reports that riluzole is an activator
of TREK-1 and TRAAK, two important members of a new structural family of
mammalian background K(+) channels with four transmembrane domains and two pore
regions. Whereas riluzole activation of TRAAK is sustained, activation of TREK-1
is transient and is followed by an inhibition. The inhibitory process is
attributable to an increase of the intracellular cAMP concentration by riluzole
that produces a protein kinase A-dependent inhibition of TREK-1. Mutants of TREK
1 lacking the Ser residue where the kinase A phosphorylation takes place are
activated in a sustained manner by riluzole. TRAAK is permanently activated by
riluzole because, unlike TREK-1, it lacks the negative regulation by cAMP.
PMID- 10779374
TI - 125I-alpha-conotoxin MII identifies a novel nicotinic acetylcholine receptor
population in mouse brain.
AB - alpha-Conotoxin MII (CtxMII), a peptide toxin from the venom of the predatory
cone snail Conus magus, displays an unusual nicotinic pharmacology. Specific
binding of a radioiodinated derivative ((125)I-alpha-CtxMII) was identified in
brain region homogenates and tissue sections. Quantitative autoradiography
indicated that (125)I-alpha-CtxMII binding sites have an unique pharmacological
profile and distribution in mouse brain, being largely confined to the
superficial layers of the superior colliculus, nigrostriatal pathway, optic
tract, olivary pretectal, and mediolateral and dorsolateral geniculate nuclei.
Expression of alpha-CtxMII binding sites in the nigrostriatal pathway, combined
with evidence for alpha-CtxMII-sensitivity of nicotine-induced [(3)H]dopamine
release in rodent striatal preparations indicates that (125)I-alpha-CtxMII
binding nicotinic acetylcholine receptors are likely to be physiologically
important. Unlabeled alpha-CtxMII potently (K(i) < 3 nM) competed for a subset of
[(3)H]epibatidine binding sites in mouse brain homogenates, but weakly (IC(50) >
10 microM) interacted with (125)I-alpha-bungarotoxin and (-)-[(3)H]nicotine
binding sites, confirming this compound's novel nicotinic pharmacology.
Quantitative autoradiography revealed that alpha-CtxMII binds with high affinity
at a subset of [(3)H]epibatidine binding sites with relatively low cytisine
affinity ("cytisine-resistant" sites), resolving [(3)H]epibatidine binding into
three different populations, each probably corresponding to a receptor subtype.
The majority population seems to correspond to that which binds nicotine and
cytisine with high affinity ("cytisine-sensitive" sites). Comparison of the
cytisine-resistant population's distribution with that of alpha3 subunit mRNA
expression suggests that the fractions both more and less sensitive to alpha
CtxMII probably contain the alpha3 subunit, perhaps in combination with different
beta subunits.
PMID- 10779375
TI - ATP, an agonist at the rat P2Y(4) receptor, is an antagonist at the human P2Y(4)
receptor.
AB - The nucleotide selectivities of the human P2Y(4) (hP2Y(4)) and rat P2Y(4)
(rP2Y(4)) receptor stably expressed in 1321N1 human astrocytoma cells were
determined by measuring increases in intracellular [Ca(2+)] under conditions that
minimized metabolism, bioconversion, and endogenous nucleotide release. In cells
expressing the hP2Y(4) receptor, UTP, GTP, and ITP all increased intracellular
[Ca(2+)] with a rank order of potency of UTP (0.55) > GTP (6.59) = ITP (7.38),
(EC(50), microM). ATP, CTP, xanthine 5'-triphosphate (XTP), and diadenosine
5',5"'-P(1), P(4)-tetraphosphate (Ap(4)A), all at 100 microM, were inactive at
the hP2Y(4) receptor. In cells expressing the rP2Y(4) receptor, all seven
nucleotides increased intracellular [Ca(2+)] with similar maximal effects and a
rank order of potency of UTP (0.20) > ATP (0. 51) > Ap(4)A (1.24) approximately
ITP (1.82) approximately GTP (2. 28) > CTP (7.24) > XTP (22.9). Because ATP is
inactive at the hP2Y(4) receptor, we assessed whether ATP displayed antagonist
activity. When coapplied, ATP shifted the concentration-response curve to UTP
rightward in a concentration-dependent manner, with no change in the maximal
response. A Schild plot derived from these data gave a pA(2) value of 6.15 (K(B)
= 708 nM) and a slope near unity. Additionally, CTP and Ap(4)A (each at 100
microM) inhibited the response to an EC(50) concentration of UTP by approximately
40 and approximately 50%, respectively, whereas XTP had no effect. The inhibitory
effects of ATP, CTP, and Ap(4)A were reversible on washout. Thus, ATP is a potent
agonist at the rP2Y(4) receptor but is a competitive antagonist with moderate
potency at the hP2Y(4) receptor.
PMID- 10779376
TI - Identification of benzodiazepine binding site residues in the gamma2 subunit of
the gamma-aminobutyric acid(A) receptor.
AB - gamma-Aminobutyric acid(A) receptor gamma-subunits are important for
benzodiazepine (BZD) binding and modulation of the gamma-aminobutyric acid
mediated Cl(-) current. Previously, by using gamma2/alpha1 chimeric subunits, we
identified two domains of the gamma2-subunit, Lys-41-Trp-82 and Arg-114-Asp-161,
that are, in conjunction, necessary and sufficient for high-affinity BZD binding.
In this study, we generated additional gamma2/alpha1 chimeric subunits and gamma2
point mutants to identify specific residues within the gamma2 Lys-41-Trp-82
region that contribute to BZD binding. Mutant gamma2 and gamma2/alpha1 chimeric
subunits were expressed with wild-type alpha1 and beta2 subunits in HEK 293
cells, and the binding of several BZDs was measured. We present evidence that the
gamma2 region Met-57-Ile-62 is important for flunitrazepam binding and that, in
particular, gamma2 Met-57 and gamma2 Tyr-58 are essential determinants for
conferring high-affinity binding. Furthermore, we identify an additional residue,
gamma2 Ala-79, that not only is important for high-affinity binding by
flunitrazepam (a strong positive modulator) but also plays a crucial role in the
binding of the imidazobenzodiazepines Ro15-1788 (a zero modulator) and Ro15-4513
(a weak negative modulator) in the BZD binding pocket. Results from site-directed
mutagenesis of gamma2 Ala-79 suggest that this residue may be part of a
microdomain within the BZD binding site that is important for binding
imidazobenzodiazepines. This separation of drug-specific microdomains for
competitive BZD ligands lends insight into the structural determinants governing
the divergent effects of these compounds.
PMID- 10779377
TI - Octamer transcription factor-1 enhances hepatic nuclear factor-1alpha-mediated
activation of the human UDP glucuronosyltransferase 2B7 promoter.
AB - The human UDP glucuronosyltransferase, UGT2B7, is expressed in the liver and
gastrointestinal tract, where it catalyzes the glucuronidation of steroids and
bile acids. In this study, the UGT2B7 gene was isolated and its proximal promoter
was analyzed. The UGT2B7 gene consists of 6 exons and extends over 16 kilobases
(kb). It does not contain a canonical TATA box but has a region (-2 to -40)
adjacent to the transcription start site that binds nuclear proteins. This region
contains a consensus hepatic nuclear factor-1alpha (HNF1alpha)-binding site and
an overlapping AT-rich segment. Varying lengths of the UGT2B7 gene promoter, with
and without these sites, were fused to the firefly luciferase reporter gene and
transfected into HepG2 cells. UGT2B7 promoter activity with the HNF1/AT-rich
element was stimulated by cotransfection with HNF1alpha. Additional activation
was observed when HNF1alpha and octamer transcription factor-1 (Oct-1) were
cotransfected simultaneously. However, Oct-1 alone did not stimulate promoter
activity and did not bind to the promoter in the absence of HNF1alpha. Deletion
of the HNF1/AT-rich region, or mutations in this region, abolished UGT2B7 gene
promoter activity and prevented HNF1alpha-mediated increases in promoter
activity. The presence of HNF1alpha and octamer transcription factor-1 (Oct-1) in
the protein complex that bound to the HNF1/AT-rich region was demonstrated by gel
shift analyses with antibodies specific to HNF1alpha and Oct-1 protein. These
results strongly suggest that the liver-enriched factor HNF1alpha binds to, and
activates, the UGT2B7 gene promoter and that the ubiquitous transcription factor,
Oct-1, enhances this activation by directly interacting with HNF1alpha. This
interaction between HNF1alpha and Oct-1 may fine-tune UGT2B7 expression.
PMID- 10779378
TI - The mechanism of phosphorylation of anti-HIV D4T by nucleoside diphosphate
kinase.
AB - The last step in the intracellular activation of antiviral nucleoside analogs is
the addition of the third phosphate by nucleoside diphosphate (NDP) kinase
resulting in the synthesis of the viral reverse transcriptase substrates. We have
previously shown that dideoxynucleotide analogs and 3'-deoxy-3'-azidothymidine
(AZT) as di- or triphosphate are poor substrates for NDP kinase. By use of
protein fluorescence, we monitor the phosphotransfer between the enzyme and the
nucleotide analog. Here, we have studied the reactivity of D4T (2',3'-dideoxy
2',3'-didehydrothymidine; stavudine) as di- (DP) or triphosphate (TP) at the pre
steady state. The catalytic efficiency of D4T-DP or -TP is increased by a factor
of 10 compared with AZT-DP or -TP, respectively. We use an inactive mutant of NDP
kinase to monitor the binding of a TP derivative, and show that the affinity for
D4T-TP is in the same range as for the natural substrate deoxythymidine
triphosphate, but is 30 times higher than for AZT-TP. Our results indicate that
D4T should be efficiently phosphorylated after intracellular maturation of a
prodrug into D4T-monophosphate.
PMID- 10779379
TI - Mutational analysis of trp-229 of human immunodeficiency virus type 1 reverse
transcriptase (RT) identifies this amino acid residue as a prime target for the
rational design of new non-nucleoside RT inhibitors.
AB - Trp-229 is part of the non-nucleoside reverse transcriptase inhibitor (NNRTI)
binding pocket of HIV type 1 (HIV-1) reverse transcriptase (RT), and is also part
of the "primer grip" of HIV-1 RT. Using site-directed mutagenesis, seven RT
mutants were constructed bearing the mutations 229Phe, 229Tyr, 229Ile, 229His,
229Lys, 229Cys, and 229Gln. We found that all of the mutants showed severely
compromised RNA- and DNA-dependent DNA polymerase activities (<2% of wild-type
activity). The recombinant 229Phe and 229Tyr RT enzymes were among the mutant
enzymes with the highest activity (0.7 and 1.1% of wild-type activity,
respectively) and we evaluated these for resistance against several NNRTIs. No
resistance was found for the 229Phe RT, but the 229Tyr RT showed a approximately
20-fold resistance against UC-781 and lower resistance against emivirine and
nevirapine. Attempts to make recombinant virus strains bearing the single 229Phe
or 229Tyr RT mutation failed. Experiments in which we varied the pentenyl ether
substituent of the thiocarboxanilide UC-781 revealed that Trp-229 can be
specifically targeted by NNRTIs and that an alkenyloxy group length of five atoms
assures an optimal interaction of the thiocarboxanilides with Trp-229. Our
findings indicate that Trp-229, when combined with other crucial immutable amino
acids (i.e., Tyr-318), is an appropriate candidate for the targeted design of new
NNRTIs.
PMID- 10779380
TI - Activation of signal transducers and activators of transcription by alpha(1A)
adrenergic receptor stimulation in PC12 cells.
AB - In PC12 cells stably expressing alpha(1A)-adrenergic receptors (ARs),
norepinephrine (NE) activates several mitogen-activated protein kinase pathways
and causes differentiation (). Using retroviral luciferase reporters, we found
that NE also activated both signal transducers and activators of transcription
(Stat) and gamma-interferon-activated sequence-mediated transcriptional
responses, with maximal effects similar to those caused by interleukin-6 (IL-6).
UTP and epidermal growth factor had no effect, whereas nerve growth factor caused
a small Stat activation. Responses to NE were blocked by prazosin and depended on
receptor density. Responses to NE were not blocked by inhibitors of mitogen
activated protein kinase kinase (PD98059), protein kinase C (GFX203290), Src
(PP2), Jak2 (AG490), or the calcium chelator 1, 2-bis(2-aminophenoxy)ethane
N,N,N',N'-tetraacetic acid. The p38 mitogen-activated protein kinase inhibitors
SB202190 and SB203580 blocked Stat activation by NE, the epidermal growth factor
receptor inhibitor AG1478 caused a small inhibition, but the phosphoinositide 3
kinase inhibitor LY294002 potentiated both responses. Gel shifts confirmed
formation of nuclear factors binding to both Stat and gamma-interferon-activated
sequence consensus sequences in response to NE and IL-6. Immunoprecipitation
experiments showed that IL-6 increased tyrosine phosphorylation of Stat1 and
Stat3 in PC12 cells, whereas NE caused a sustained increase in tyrosine
phosphorylation of Stat1. These results suggest that alpha(1A)-AR stimulation
causes Stat-mediated transcriptional responses in PC12 cells that are not
downstream of known second messenger or tyrosine kinase pathways.
PMID- 10779381
TI - [(3)H]MRE 3008F20: a novel antagonist radioligand for the pharmacological and
biochemical characterization of human A(3) adenosine receptors.
AB - The lack of a radiolabeled selective A(3) adenosine receptor antagonist is a
major drawback for an adequate characterization of this receptor subtype. This
paper describes the pharmacological and biochemical characterization of the
tritiated form of a new potent A(3) adenosine receptor antagonist, the pyrazolo
triazolo pyrimidine derivative [(3)H]5N-(4-methoxyphenylcarbamoyl)amino-8-propyl
2-(2-furyl )pyrazolo [4,3-e] -1,2,4- triazolo[1,5-c]pyrimidine ([(3)H]MRE
3008F20). [(3)H]MRE 3008F20 bound specifically to the human adenosine A(3)
receptor expressed in CHO cells (hA(3)CHO), and saturation analysis revealed a
single high affinity binding site, K(D) = 0.80 +/- 0.06 nM, with a B(max) = 300
+/- 33 fmol/mg protein. This new ligand displayed high selectivity (1294-, 165-,
and 2471-fold) in binding assay to human A(3) versus A(1), A(2A), and A(2B)
receptors, respectively, and binds to the rat A(3) receptors with a K(i) > 10
microM. The pharmacological profile of [(3)H]MRE 3008F20 binding to hA(3)CHO
cells was evaluated using known adenosine receptor agonists and antagonists with
a rank order of potency consistent with that typically found for interactions
with the A(3) adenosine receptors. In the adenylyl cyclase assay the same
compounds exhibited a rank order of potency identical with that observed in
binding experiments. Thermodynamic data indicated that [(3)H]MRE 3008F20 binding
to hA(3)CHO is entropy- and enthalpy-driven in agreement with the typical
behavior of other adenosine antagonists to A(1) and A(2A) receptors. These
results show that [(3)H]MRE 3008F20 is the first antagonist radioligand with high
affinity and selectivity for the human A(3) adenosine receptor and may be used to
investigate the physiopathological role of A(3) adenosine receptors.
PMID- 10779382
TI - Pharmacological properties of Y-27632, a specific inhibitor of rho-associated
kinases.
AB - Y-27632 [(+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide++ +
dihydrochloride] is widely used as a specific inhibitor of the Rho-associated
coiled-coil forming protein serine/threonine kinase (ROCK) family of protein
kinases. This study examined the inhibition mechanism and profile of actions of Y
27632 and a related compound, Y-30141 [(+)-(R)-trans- 4-(1-aminoethyl)-N-(1H
pyrrolo[2, 3-b]pyridin-4-yl)cyclohexan-ecarboxamide dihydrochloride]. Y-27632 and
Y-30141 inhibited the kinase activity of both ROCK-I and ROCK-II in vitro, and
this inhibition was reversed by ATP in a competitive manner. This suggests that
these compounds inhibit the kinases by binding to the catalytic site. Their
affinities for ROCK kinases as determined by K(i) values were at least 20 to 30
times higher than those for two other Rho effector kinases, citron kinase and
protein kinase PKN. [(3)H]Y-30141 was taken up by cells in a temperature- and
time-dependent and saturable manner, and this uptake was competed with unlabeled
Y-27632. No concentrated accumulation was found, suggesting that the uptake is a
carrier-mediated facilitated diffusion. Y-27632 abolished stress fibers in Swiss
3T3 cells at 10 microM, but the G(1)-S phase transition of the cell cycle and
cytokinesis were little affected at this concentration. Y-30141 was 10 times more
potent than Y-27632 in inhibiting the kinase activity and stress fiber formation,
and it caused significant delay in the G(1)-S transition and inhibition of
cytokinesis at 10 microM.
PMID- 10779383
TI - Role for early growth response-1 protein in alpha(1)-adrenergic stimulation of
fibroblast growth factor-2 promoter activity in cardiac myocytes.
AB - Fibroblast growth factor-2 (FGF-2), a mitogenic, angiogenic, and cardioprotective
agent, is released from the postnatal heart by a mechanism of transient
remodelling of the sarcolemma during contraction. Both release of FGF-2 and its
synthesis can be increased with adrenergic stimulation. We reported previously
that FGF-2 synthesis can be regulated at the transcriptional level by alpha
adrenergic stimulation of cultured neonatal rat cardiac myocytes as well as in
the adult mouse heart. Examination of the proximal promoter region of both human
and rat FGF-2 gene sequences revealed binding sites for the early growth response
1 (Egr-1) protein. Using gel mobility shift assays, we observed a transient
increase in a complex between nuclear extracts from neonatal rat cardiac myocytes
treated with inducers of Egr-1, including the alpha-adrenergic agonist
phenylephrine, angiotensin II, and phorbol ester, and a consensus Egr-1 DNA
element. A similar complex was seen with the FGF-2 promoter region -7/+42 as the
DNA probe, but not when the Egr-1 element at nucleotides +3/+31 was disrupted.
Participation of Egr-1 protein in the complex was confirmed by competition with
Egr-1 DNA elements and antibodies. With deletion analysis and transfection of
neonatal rat cardiac myocytes, the alpha-adrenergic response was localized to
nucleotides -110/+42 of the FGF-2 gene in the context of a hybrid FGF
2/luciferase reporter gene, -110FGFp.luc. Overexpression of Egr-1 increased
110FGFp.luc gene expression, whereas mutation of its Egr-1 element at nucleotides
+3/+31 abolished alpha-adrenergic responsiveness. These data indicate that Egr-1
is involved in the alpha-adrenergic stimulation of the FGF-2 promoter region in
neonatal cardiac myocytes.
PMID- 10779384
TI - Analysis of a mutation in phosphodiesterase type 4 that alters both inhibitor
activity and nucleotide selectivity.
AB - Cyclic nucleotide phosphodiesterase type 4 (PDE4) is a cAMP-specific
phosphodiesterase that is found as four distinct genes in the mammalian genome
(PDE4A, 4B, 4C, and 4D). Mutation analysis was done to identify the amino acids
involved in activity and inhibitor selectivity. Mutations at Asp333 were made in
HSPDE4D3 based on mutations that affect rolipram sensitivity in RNPDE4B1. The
PDE4D3 Asp-Asn mutant was resistant to inhibition by rolipram as well as several
other PDE4 inhibitors tested. These results suggest that this residue is near the
inhibitor binding pocket in PDE4D3. Sequence comparison of PDE4 with cGMP
specific PDE proteins shows a conserved aspartic acid at position 333 in PDE4D3
and a conserved asparagine at this position in PDE enzymes that hydrolyze cGMP.
Therefore, cGMP hydrolysis by PDE4D3 Asp-Asn was measured. PDE4D3 Asp-Asn
hydrolyzes cGMP with kinetic constants similar to those observed for this protein
with cAMP (K(m) approximately 20 microM, V(max) approximately 2 micromol
AMP/min/mg recombinant protein). Under identical conditions, the K(m) value for
cAMP hydrolysis by wild-type PDE4D3 is 3 microM and the V(max) value is 1
micromol AMP/min/mg recombinant protein. In addition, the PDE4D3 Asp-Ala mutant
protein could hydrolyze cGMP. Finally, the analogous mutation in HSPDE4B1
(Asp413Asn) also allows hydrolysis of cGMP. These results show that this aspartic
acid residue is important in inhibitor binding and nucleotide discrimination and
suggest this residue is in the active site of PDE4.
PMID- 10779385
TI - Activation of cannabinoid receptors in rat brain by WIN 55212-2 produces coupling
to multiple G protein alpha-subunits with different potencies.
AB - Previous studies had shown that the amplification factors for cannabinoid
receptors, defined as the number of total G proteins activated per occupied
receptor, differs between several rat brain regions. In this study, we sought to
determine which specific Gi/Go(alpha) subunits were activated by CB1 receptors in
several rat brain regions and if this coupling might explain the regional
differences in receptor/G protein amplification factors. Furthermore, we examined
whether cannabinoid agonists might activate different subtypes of G(alpha)
subunits with varying degrees of efficacy and/or potency. Activation of specific
G proteins by cannabinoid receptors was evaluated by the ability of the agonist
WIN 55212-2 to stimulate incorporation of [alpha-(32)P]azidoanilido-GTP into
G(alpha) subunits in membranes. Photolabeled G proteins were either directly
resolved using urea/SDS-polyacrylamide gel electrophoresis or first
immunoprecipitated with specific antisera for different G(alpha) subunits before
electrophoresis. Individual G(alpha) subunits were separated into distinct bands
on a single gel and the amount of agonist-induced increase in radioactivity was
quantified by densitometry. Stimulation of CB1 receptors by WIN 55212-2 resulted
in the activation of a distinct pattern of at least five different
G(ialpha)/G(oalpha) subunits in several brain regions. Furthermore, although the
pattern of G proteins activated by WIN 55212-2 appeared to be similar across
brain regions, slight differences were observed in both the percentage of
increase and the amount of the individual G(alpha) subunits activated. Most
importantly, the amount of WIN 55212-2 required to half-maximally activate
individual G proteins in the cerebellum varied over a 30-fold range for different
G(alpha) subunits. These results suggest that cannabinoid receptors activate
multiple G proteins simultaneously in several brain regions and both the efficacy
and potency of cannabinoid agonists to activate individual G(alpha) subunits may
vary considerably.
PMID- 10779386
TI - Increased CYP2J expression and epoxyeicosatrienoic acid formation in
spontaneously hypertensive rat kidney.
AB - Epoxyeicosatrienoic acids (EETs) are major products of cytochrome P450 (CYP)
catalyzed metabolism of arachidonic acid in the kidney. The potent effect of EETs
on renal vascular tone and tubular ion and water transport implicates their role
in the regulation of renal function and blood pressure. The present study was
designed to test the hypothesis that CYP-catalyzed EET formation was altered in
the spontaneously hypertensive rat (SHR) kidney. The formation of 14,15- and
11,12-EET was approximately 2-fold higher in incubations of arachidonic acid with
SHR renal cortical microsomes relative to microsomes from normotensive Wistar
Kyoto (WKY) rats. This was consistent with increased expression of a CYP2J2
immunoreactive protein in the SHR cortex and outer medulla. In contrast, there
was no significant difference in the levels of the CYP2E and CYP2C epoxygenases
in SHR and WKY kidneys. Protein and RNA analysis suggests that the CYP2J2
immunoreactive protein that is overexpressed in the SHR kidney is distinct from
the known rat CYP2J isoforms. EET formation also was documented in vivo from
measurements of urinary EET excretion. Importantly, the excretion rates of 14,15
, and 11,12-EETs were 2.5- and 1.8-fold higher, respectively, in SHR than WKY
kidney. These studies provide both in vitro and in vivo evidence for increased
EET formation in the SHR kidney and identify a novel CYP2J2 immunoreactive
protein that is differentially expressed in the hypertensive kidney. In light of
the known biological properties of the EETs, these findings may be important in
elucidating the mechanisms that control renal vascular tone and tubular ion
transport in the SHR.
PMID- 10779387
TI - Inhibition of aquaporin-1 water permeability by tetraethylammonium: involvement
of the loop E pore region.
AB - Previously, the only known blockers of water permeability through aquaporin-1
(AQP1) water channels were mercurial reagents such as HgCl(2). For AQP1,
inhibition by mercury has been attributed to the formation of a mercaptide bond
with cysteine residue 189 found in the putative pore-forming region loop E. Here
we show that the nonmercurial compound, tetraethylammonium (TEA) chloride,
reduces the water permeability of human AQP1 channels expressed in Xenopus
oocytes. After preincubation of the oocytes for 15 min with 100 microM TEA, AQP1
water permeability was reduced by 20 to 40%, a degree of partial block similar to
that obtained with 15 min of incubation in 100 microM HgCl(2). The reduction of
water permeability was dose-dependent for tested concentrations up to 10 mM TEA.
TEA blocks the Shaker potassium channel by interacting with a tyrosine residue in
the outer pore region. We tested whether an analogous tyrosine residue in loop E
of AQP1 could be involved in the binding of TEA. Using polymerase chain reaction,
tyrosine 186 in AQP1, selected for its proximity to the mercury-binding site, was
mutated to phenylalanine (Y186F), alanine (Y186A), or asparagine (Y186N). Oocyte
expression of the mutant AQP1 channels showed that the water permeability of
Y186F was equivalent to that of wild-type AQP1; the other mutant channels did not
conduct water. However, in contrast to wild-type AQP1, the water permeability of
Y186F was not reduced with 100 microM TEA. These results suggest that TEA reduces
AQP1 water permeability by interacting with loop E.
PMID- 10779388
TI - Lysophosphatidic acid modulates alpha(1b)-adrenoceptor phosphorylation and
function: roles of Gi and phosphoinositide 3-kinase.
AB - The effect of lysophosphatidic acid on the phosphorylation and function of
alpha(1b)-adrenoceptors transfected into rat-1 fibroblasts was studied. This
phospholipid mitogen increased in a concentration-dependent fashion (EC(50)
approximately 50 nM) the phosphorylation of these adrenoceptors. Lysophosphatidic
acid-induced alpha(1b)-adrenoceptor phosphorylation was relatively rapid (t(1/2)
approximately 1 min), intense (2.5-fold), and sustained for at least 60 min. The
effect of lysophosphatidic acid was blocked by pretreatment with pertussis toxin.
The alpha(1b)-adrenoceptor phosphorylation induced by lysophosphatidic acid was
not blocked by genistein, a tyrosine kinase inhibitor, but it was inhibited by
inhibitors of protein kinase C (bisindolylmaleimide I, staurosporine, and Ro 31
8220) and phosphoinositide 3-kinase (wortmannin and LY 294002). The ability of
norepinephrine to increase cytosol calcium concentration was markedly decreased
in cells previously challenged with lysophosphatidic acid. Norepinephrine-induced
[(35)S]GTPgammaS binding in membrane preparations was used as an index of the
functional coupling of the alpha(1b)-adrenoceptors and G proteins. Norepinephrine
stimulated [(35)S]GTPgammaS binding was markedly decreased in membranes from
cells pretreated with lysophosphatidic acid. This effect of lysophosphatidic acid
was blocked by pretreatment with wortmannin or staurosporine. Our data indicate
that: 1) activation of lysophosphatidic acid receptors induce phosphorylation of
alpha(1b)-adrenoceptors; 2) this effect is mediated through pertussis toxin
sensitive G proteins, phosphatidylinositol 3-kinase, and protein kinase C; and 3)
the phosphorylation of alpha(1b)-adrenoceptors induced by the lipid mitogen is
associated to adrenoceptor desensitization.
PMID- 10779389
TI - Human 5-hydroxytryptamine(5A) receptors activate coexpressed G(i) and G(o)
proteins in Spodoptera frugiperda 9 cells.
AB - The ability of the human 5-hydroxytryptamine serotonin type 5A (h5-ht(5A))
receptor to couple to G proteins from distinct families was investigated through
the simultaneous infection of Spodoptera frugiperda 9 insect cells with
recombinant baculoviruses encoding the various proteins. Expression of G proteins
was demonstrated in immunoblots. Receptor-G protein coupling was monitored by
high-affinity agonist binding and agonist-induced stimulation of [(35)S]guanosine
5'-O-(3-thio) triphosphate binding to membranes. Receptors expressed alone
displayed low-affinity agonist binding, and endogenous G proteins were only
poorly stimulated on the addition of 5-hydroxytryptamine. When receptors were
coexpressed with mammalian G(i)/G(o) proteins (Galpha(i) or Galpha(o) plus
Gbeta(1)gamma(2)), the coupled phenotype was achieved: agonists bound with high
affinity in a guanosine-5'-(beta, gamma-imido)triphosphate-sensitive manner and
stimulated [(35)S]guanosine-5'-O-(3-thio)triphosphate binding to high levels.
These effects were not observed on coexpression with G(z)/G(s)/G(q/11/16) or
G(12/13). Various ligands were evaluated for their agonistic, antagonistic, or
inverse agonistic behavior in both receptor binding and activation assays.
Although G(o) displayed different receptor coupling characteristics than G(i)
proteins, no clear coupling preference was evident. Coexpression of receptors and
Galpha(i) subunits without Gbeta(1)gamma(2) produced increases in both agonist
affinity and maximum G protein activation that were smaller than those in the
presence of Gbeta(1)gamma(2), suggesting that Gbeta(1)gamma(2) coexpression
improves receptor-G protein coupling. Similarly, coexpression of receptors with
Gbeta(1)gamma(2) alone resulted in an improved interaction with endogenous G
proteins. Our results demonstrate that h5-ht(5A) receptors expressed in
Spodoptera frugiperda 9 cells selectively and functionally couple to coexpressed
mammalian G(i) and G(o) proteins.
PMID- 10779390
TI - Endocannabinoid 2-arachidonyl glycerol is a full agonist through human type 2
cannabinoid receptor: antagonism by anandamide.
AB - The endocannabinoids anandamide and 2-arachidonyl glycerol (2-AG) bind to G
protein-coupled central and peripheral cannabinoid receptors CB1 and CB2,
respectively. Due to the relatively high expression of the CB2 isotype on
peripheral immune cells, it has been hypothesized that this receptor mediates the
immunosuppressive effects of cannabinoids. Unfortunately, there was a dearth of
pharmacological studies with the endocannabinoids and human CB2 (hCB2). These
studies compare and contrast the potency and efficacy of anandamide, 2-AG, and
the synthetic cannabinoid HU210 at hCB2. Using [(35)S]guanosine-5'-O-(3
thio)triphosphate (GTPgammaS) and radioligand bindings in insect Sf9-hCB2
membranes, we showed that both endocannabinoids bound hCB2 with similar affinity
and that the cannabinoids acted as full agonists in stimulating [(35)S]GTPgammaS
exchange, although 2-AG was 3-fold more potent than anandamide (EC(50) = 38.9 +/-
3.1 and 121 +/- 29 nM, respectively). In a mammalian expression system (Chinese
hamster ovary-hCB2 cells), HU210 and 2-AG maximally inhibited forskolin
stimulated cAMP synthesis (IC(50) = 1.61 +/- 0.42 nM and 1.30 +/- 0.37 microM,
respectively) although anandamide was ineffective. In Chinese hamster ovary-hCB2
membranes, HU210 and 2-AG were also full agonists in stimulating [(35)S]GTPgammaS
binding (EC(50) = 1.96 +/- 0.35 and 122 +/- 17 nM, respectively), but anandamide
was a weak partial agonist (EC(50) = 261 +/- 91 nM; 34 +/- 4% of maximum). Due to
its low intrinsic activity, coincubation with anandamide effectively attenuated
the functional activity of 2-AG at hCB2. Collectively, the data showed that both
endocannabinoids bound hCB2 with similar affinity, but only 2-AG functioned as a
full agonist. Moreover, the agonistic activity of 2-AG was attenuated by
anandamide.
PMID- 10779391
TI - Excision of beta-D- and beta-L-nucleotide analogs from DNA by the human cytosolic
3'-to-5' exonuclease.
AB - The cytosolic 3'-to-5' exonuclease from chronic lymphocytic leukemia cells was
highly purified, and its ability to remove beta-D- and beta-L-nucleotide analogs
from the 3'-end of DNA was determined. The relative rate of excision of beta-D
ddCMP, beta-L-ddCMP, beta-L-FddCMP, beta-L-SddCMP, beta-L-Fd4CMP, and beta-L
OddCMP from the 3'-end of a single-stranded oligonucleotide primer or a primer
annealed with complementary DNA and/or RNA templates was assessed. The rate of
excision of beta-D-nucleotides from the 3'-end of DNA was higher than that of
beta-L-nucleotides, which could be partly attributable to the affinity of the
enzyme to beta-D-nucleotide-terminated DNA being 5-fold higher compared with that
of beta-L-nucleotide-terminated DNA. The rate of removal of beta-L-Fd4CMP and
beta-L-OddCMP from the 3'-end of DNA was at least 8 to 10 times lower compared
with that of beta-L-SddCMP. HIV reverse transcriptase could elongate DNA primers
after the removal of chain terminators by the cytosolic exonuclease.
Concentrations of nucleoside 5'-monophosphate analogs that inhibit the cytosolic
exonuclease by 50% were estimated. Among the nucleoside 5'-monophosphate analogs
examined, beta-L-Fd4CMP appeared to be the most effective inhibitor of the
cytosolic exonuclease, with an ID(50) value of 38 microM.
PMID- 10779392
TI - Altered cell cycle control at the G(2)/M phases in aryl hydrocarbon receptor-null
embryo fibroblast.
AB - The aryl hydrocarbon receptor (AHR) is known to mediate the toxic and
carcinogenic effects of polycyclic aromatic hydrocarbons and dioxins. High
affinity AHR ligands, such as 2,3,7, 8-tetrachlorodibenzeno-p-dioxin, have been
shown to modify cell proliferation and differentiation. However, the mechanisms
by which AHR affects cell proliferation and differentiation are not fully
understood. To investigate the role of AHR in cell proliferation, mouse embryonic
fibroblasts (MEFs) derived from AHR-null mice were obtained and characterized.
Compared with wild-type MEFs, AHR-null cells exhibited a lower proliferation rate
with an accumulation of 4N DNA content and increased apoptosis. The expression
levels of Cdc2 and Plk, two kinases important for G(2)/M phase of cell cycle,
were down-regulated in AHR-null MEFs. In contrast, transforming growth factor
beta (TGF-beta), a proliferation inhibitor in several cell lines, was present at
high levels in conditioned medium from AHR-null MEFs. Concomitant with G(2)/M
cell accumulation, treatment of wild-type MEFs with TGF-beta3 also resulted in
down-regulation of both Cdc2 and Plk. Thus, overproduction of TGF-beta in AHR
deficient cells appears to be the primary factor that causes low proliferation
rates and increased apoptosis. Taken together, these results suggest that AHR
influences TGF-beta production, leading to an alteration in cell cycle control.
PMID- 10779393
TI - Involvement of regions in domain I in the opioid receptor sensitivity of alpha1B
Ca(2+) channels.
AB - The structural basis of Ca(2+) channel inhibition by G proteins has received
considerable attention recently, and multiple regions on Ca(2+) channels that
interact with G protein subunits have been identified. We have demonstrated
previously that a region extending from the N terminus to the I/II loop of the
Ca(2+) channel is involved in determining the differences between alpha1B and
alpha1E Ca(2+) channels with respect to inhibition by G proteins. Here we explore
this region of the channel in greater detail in an effort to further define the
regions involved in determining inhibition. Chimeric Ca(2+) channels constructed
from alpha1B and alpha1E Ca(2+) channels revealed that the N terminus, the I/II
loop, and domain I all play an important role in determining inhibition. We
identified a 70-amino acid fragment from domain I that mediates the effects of
domain I, and a 50-amino acid fragment from the I/II loop that mediates the
effects of the I/II loop. When these regions from alpha1B were exchanged into
alpha1E, inhibition identical with that of alpha1B was observed. The differences
between alpha1B and alpha1E in the identified region of domain I involve residues
that are predicted to be almost exclusively extracellular. Mutations to some of
the high-affinity G protein binding regions of alpha1B (alpha interaction domain,
CC14, and a C-terminal Galpha binding site) caused relatively little change in
inhibition, which suggests that these sites are not necessary individually for G
protein-mediated inhibition and may help to explain the small effects of
exchanging these regions in isolation.
PMID- 10779394
TI - Selective enhancement of beta-adrenergic receptor signaling by overexpression of
adenylyl cyclase type 6: colocalization of receptor and adenylyl cyclase in
caveolae of cardiac myocytes.
AB - We investigated the effect of adenovirally mediated overexpression of adenylyl
cyclase type 6 (AC6), a major form of AC expressed in mammalian heart, on G
protein-coupled receptor regulation of cAMP production in neonatal rat
ventricular myocytes. Following gene transfer of AC6, isoproterenol- and
forskolin-stimulated increases in cAMP were markedly enhanced, whereas basal
levels of cAMP and responses to several other agonists that stimulate cAMP
formation, e. g., prostaglandin E(2) (PGE(2)), H(2) agonist, glucagon, and A(2)
agonist were not increased. Studies to test whether the selective enhancement in
beta-adrenergic receptor (AR) response might result from inhibition of AC6 by
Galpha(i) and Gbetagamma indicated that pertussis toxin-sensitive inhibition by
the muscarinic cholinergic agonist carbachol was unaltered in myocytes
overexpressing AC6. Pertussis toxin treatment failed to reveal an enhancement by
AC6 overexpression of basal or PGE(2)-stimulated cAMP. Immunoblot analysis of
membrane fractions indicated that beta(1)-AR and AC6 are expressed in fractions
enriched in caveolin-3 and morphologic caveolae. The data suggest that loss of
G(i)-mediated inhibition is not the mechanism for enhancement of beta-AR
stimulated cAMP formation and that key components of beta-AR-mediated activation
of AC exist in caveolae of cardiac myocytes, providing a means by which beta-AR
response is selectively enhanced by increasing AC6 expression.
PMID- 10779395
TI - Understanding circadian rhythmicity in Neurospora crassa: from behavior to genes
and back again.
AB - Circadian clocks have been described in organisms ranging in complexity from
unicells to mammals, in which they function to control daily rhythms in cellular
activities and behavior. The significance of a detailed understanding of the
clock can be appreciated by its ubiquity and its established involvement in human
physiology, including endocrine function, sleep/wake cycles, psychiatric illness,
and drug tolerances and effectiveness. Because the clock in all organisms is
assembled within the cell and clock mechanisms are evolutionarily conserved,
simple eukaryotes provide appropriate experimental systems for dissecting the
clock. Significant progress has been made in deciphering the circadian system in
Neurospora crassa using both genetic and molecular approaches, and Neurospora has
contributed greatly to our understanding of (1) the feedback cycle that comprises
a circadian oscillator, (2) the mechanisms by which the clock is kept in
synchrony with the environment, and (3) the genes that reside in rhythmic output
pathways. Importantly, the lessons learned in Neurospora are relevant to our
understanding of clocks in higher eukaryotes.
PMID- 10779396
TI - The complete DNA sequence of the nuclear ribosomal RNA gene complex of
Verticillium dahliae: intraspecific heterogeneity within the intergenic spacer
region.
AB - The complete DNA sequence of the nuclear ribosomal RNA gene complex of
Verticillium dahliae: Intraspecific heterogeneity within the intergenic spacer
region. Fungal Genetics and Biology 29, 19-27. The complete sequence of the
nuclear ribosomal DNA gene complex of the phytopathogenic fungus Verticillium
dahliae has been determined. The tandemly repeated unit was 7216 bp long and
appears to be the shortest rDNA cluster described so far among filamentous fungi.
Primer pairs were designed for amplification of the region spanning half of the
28S subunit, the intergenic spacer (IGS), and the 5' end of 18S subunit of a
number of Verticillium strains, isolated from various hosts and geographic
origins. Great heterogeneity was detected in the amplified products of the IGS
region resulting in fragments varying from 1.6 to 2.0 kb. The majority of
Verticillium isolates were classified into two groups with 1.6- and 1.7-kb
amplified products, respectively. The former group included 31 V. dahliae, 7 V.
longisporum, and 1 V. albo-atrum isolates, whereas the latter included 10 V.
dahliae and 1 V. albo-atrum isolates. Sequence analysis of representative PCR
products of the above groups identified a "hot-spot" region harboring most of
larger insertions, whereas most of the small changes were due to transitions and
transversions. One V. longisporum isolate with a 2.0-kb PCR product contained 13
perfectly conserved tandem repeats of 39 bp long. The presence of similar
incomplete sequences in the corresponding regions of V. dahliae, V. longisporum,
and V. albo-atrum isolates revealed a particular standard motif of insertions in
the IGS region of the genus and is discussed.
PMID- 10779397
TI - Using DNA-tagged mutagenesis to improve heterologous protein production in
Aspergillus oryzae.
AB - Using DNA-tagged mutagenesis to improve heterologous protein production in
Aspergillus oryzae. Fungal Genetics and Biology 29, 28-37. Restriction enzyme
mediated integration (REMI) has been employed as a mutagen to generate two
insertion libraries in an Aspergillus oryzae strain expressing a Thermomyces
lanuginosus lipase. The REMI libraries were created using linearized plasmid
containing the A. oryzae pyrG and either BamHI or EcoRI enzyme. The libraries
were screened for lipase production, and mutants with increased production were
isolated. The genomic DNA flanking the integration event was cloned from one of
the mutants with increased lipase titers (DEBY10.3). Nucleotide sequence of the
flanking DNA revealed similarity to the Aspergillus nidulans palB gene.
Disruption of the palB gene in a strain producing lipase resulted in increased
lipase expression. Additionally, complementation of the palB phenotype of
DEBY10.3 led to a decrease in lipase production. These lines of evidence
demonstrate that the increase in lipase yield in DEBY10.3 is linked to the palB
phenotype generated by the integration of the pyrG gene into the palB gene. The
results also demonstrated that tagged mutagenesis with REMI can be used to
identify genes that influence expression of heterologous proteins.
PMID- 10779398
TI - Gene disruption by biolistic transformation in serotype D strains of Cryptococcus
neoformans.
AB - Gene disruption by biolistic transformation in serotype D strains of Cryptococcus
neoformans. Fungal Genetics and Biology 29, 38-48. Cryptococcus neoformans is an
opportunistic fungal pathogen with a defined sexual cycle and well-developed
genetic and molecular approaches. Two different transformation systems have been
developed, and a number of genes have been disrupted by homologous recombination.
However, the frequency of homologous recombination achieved by these approaches
has differed dramatically between strains of the A and D serotypes.
Transformation by electroporation in serotype D strains results in homologous
recombination at frequencies of 1/1000 to 1/100,000, whereas transformation by
the biolistic method has resulted in gene disruption at frequencies between 2 and
50% in serotype A strains. We find that gene disruption by homologous
recombination can be achieved in the congenic serotype D strain series by
biolistic transformation with frequencies of approximately 1 to 4%. By this
approach, we have readily disrupted the genes encoding a MAPK homolog (CPK1), the
calcineurin A catalytic subunit (CNA1), and a G protein alpha subunit (GPA1). By
physical and genetic methods, we show that these mutations result from targeted
recombination events without ectopic integrations. Because genetic approaches can
be applied in the congenic serotype D strains, our observations represent a
significant advance in molecular approaches to understand the physiology and
virulence of this important human pathogen.
PMID- 10779399
TI - A mutation in the eln2 gene encoding a cytochrome P450 of Coprinus cinereus
affects mushroom morphogenesis.
AB - A dominant mutation of the elongationless2 (eln2) gene of the mushroom Coprinus
cinereus (eln2-1) affects pattern formation in the development of fruit body
primordia, causing dumpy primordia which culminate in mature fruit bodies with
short stipes. Phenotypic analyses revealed disturbance of tissue organization and
cell morphogenesis in the primordial shaft and suggested that the defects in the
primordial shaft interfere with differentiation of the stipe tissue in the mutant
primordia. The eln2 locus was assigned to chromosome XII and the eln2-1 mutant
gene was cloned from a chromosome XII-specific cosmid library as a genomic
fragment that brings about the dominant mutant phenotype. The eln2 gene encodes a
novel type of microsomal cytochrome P450 enzyme (CYP502) and is constitutively
expressed. The eln2-1 mutation is a 4-bp deletion in the 3'-terminal region of
the gene, leading to truncation of C-terminal 18 amino acids. We suggest that the
truncation affects the activity of the CYP502 enzyme.
PMID- 10779400
TI - Insights into HIV-specific immune function: implications for therapy and
prevention in the new millennium.
PMID- 10779401
TI - Pulmonary alveolar proteinosis is a disease of decreased availability of GM-CSF
rather than an intrinsic cellular defect.
AB - Granulocyte-macrophage colony stimulating factor (GM-CSF) deficient mice develop
a pulmonary alveolar proteinosis (PAP) syndrome which is corrected by the
administration/expression of GM-CSF. These observations implicate GM-CSF in the
pathogenesis of human PAP. We hypothesized that human PAP may involve an
intrinsic cellular defect in monocytes/macrophages with an inability to produce
GM-CSF and/or respond to GM-CSF. Thus, we investigated the cytokine responses to
GM-CSF and LPS from peripheral blood monocytes and alveolar macrophages from
patients with idiopathic PAP and healthy controls. Macrophage inflammatory
protein-1-alpha (MIP) was measured from GM-CSF-stimulated cells and GM-CSF was
measured from LPS-stimulated cells by ELISA. The MIP and GM-CSF production by
monocytes and alveolar macrophages did not differ between PAP patients and
healthy controls. Growth of the GM-CSF-dependent human myeloid cell line TF-1 was
inhibited by serum from all patients studied (n = 10) and all patients had anti
GM-CSF antibody in their serum. The BAL from PAP patients had less detectable GM
CSF by ELISA than healthy controls (P = 0.05); in contrast, the inhibitory
cytokine, interleukin-10 (IL-10), was increased in PAP compared to controls (P =
0.04). IL-10 is a potent inhibitor of LPS-stimulated GM-CSF production from
healthy control alveolar macrophages. These studies are the first to demonstrate
that circulating monocytes and alveolar macrophages from PAP patients are able to
synthesize GM-CSF and respond to GM-CSF, suggesting no intrinsic abnormalities in
GM-CSF signaling. In addition, these observations suggest that PAP in a subset of
patients is the result of decreased availability of GM-CSF due to GM-CSF blocking
activity and reduced GM-CSF production by IL-10.
PMID- 10779402
TI - The microbial product lipopolysaccharide confers diabetogenic potential on the T
cell repertoire of BDC2.5/NOD mice: implications for the etiology of autoimmune
diabetes.
AB - Both genetic predisposition and environmental factors participate in the etiology
of Type-1 diabetes. To test the role of the microbial product lipopolysaccharide
(LPS) as an environmental trigger of autoimmune diabetes, we employed transgenic
(tg) BDC2.5/NOD mice that bear an islet-specific CD4(+) T cell repertoire (>95%),
but do not develop the spontaneous diabetes that typifies the NOD (nonobese
diabetic) strain. LPS administration provoked diabetes in BDC2.5/NOD mice by
their 16th week of age. However, LPS administration in NOD mice did not
accelerate their diabetes. This finding indicates that the frequency of islet
specific T cells influences LPS-mediated diabetes. Furthermore, in vitro LPS
cultured splenocytes from BDC2. 5/NOD and BDC2.5-microMT (B-cell-deficient) mice
effectively transferred diabetes into immunodeficient NOD-scid/scid mice but not
immunosufficient NOD mice. Therefore, B lymphocytes are not required for LPS
provoked autoimmune diabetes. Flow cytometric analysis then revealed that LPS
stimulation in vitro induced the expression of an IL-2 receptor (CD25) on CD4 T
cells; this indicates that the activation of islet-specific T cells is a
prerequisite to eliciting diabetes in this situation. Overall, these results
point to microbial LPS as an etiopathogenic agent of autoimmune diabetes.
PMID- 10779403
TI - Evaluation of assays for the detection of autoantibodies to the ribosomal P
proteins.
AB - Sera from systemic lupus erythematosus patients that had antibodies to the
ribosomal P proteins were compared in several different assays. The enzyme-linked
immunosorbent assay (ELISA) method was compared to the Western immunoblotting
method using either affinity purified human or bovine ribosomal P proteins. All
30 normal sera had no significant reactivity with these antigens. The most
sensitive test was the ELISA using the human P protein, where 31/32 patients were
positive (97%). The assay with bovine proteins in ELISA yielded 28/32 (88%)
positive results. Immunoblotting with either bovine or human P protein was
equally effective with 30/32 (94%) positive. An ELISA incorporating human P
proteins is a more sensitive assay for clinical diagnosis than an ELISA with the
bovine protein. Immunoblotting is a sensitive method, but is less convenient and
is not quantitative. The ELISA with the human protein appears to be the method of
choice.
PMID- 10779404
TI - Intratracheal administration to the lung enhances therapeutic benefit of an MBP
peptide in the treatment of murine experimental autoimmune encephalomyelitis.
AB - The treatment of autoimmune diseases by targeted down-regulation of autoantigen
specific cells has been accomplished by the administration of high doses of
autoantigen. We performed direct comparisons between injection of myelin basic
protein peptide and administration by several nonparenteral routes to determine
whether route impacted benefit in the treatment of murine allergic
encephalomyelitis, a model for multiple sclerosis. The range of effective peptide
doses spanned over 1000-fold, and route of delivery played a major role in
determining optimal dose. The oral route of administration was the least
effective, requiring at least 50- to 100-fold more antigen than subcutaneous
injection, which in turn required at least 10-fold more antigen than delivery of
peptide to the lung using an intratracheal instillation. Intratracheal delivery
was also considerably more effective than inhalation of peptide, and, unlike
inhalation, resulted in obvious penetration of delivered material deep into the
lung. The increase in therapeutic efficacy did not appear to result from slower
systemic delivery of antigen. Accumulation of peptide on antigen presenting cells
in the spleen and in the brain was less efficient using the intratracheal route
of administration compared to subcutaneous injection, implicating a special role
for the lung microenvironment in the induction of immune nonresponsiveness.
PMID- 10779406
TI - Molecular mechanisms involved in the estrogen-dependent regulation of calcineurin
in systemic lupus erythematosus T cells.
AB - Previous experiments in our laboratory indicated that calcineurin expression and
PP2B phosphatase activity increased when estrogen was cultured with SLE T cells
but not with T cells from normal women. In this report we extended our findings
to show that estrogen receptor (ER) antagonism by ICI 182,780 inhibited the
estrogen-dependent increase in calcineurin mRNA and phosphatase PP2B activity
indicating that estrogen action was mediated through the ER. Inhibition of de
novo protein synthesis with cycloheximide suggested that the estrogen-dependent
increase in T cell calcineurin mRNA was a direct effect of the ER and new protein
synthesis was not required. Estrogen increased calcineurin mRNA in systemic lupus
erythematosus (SLE) T cells at 6 h after the start of culture correlating with
increased phosphatase activity at this same time. Phosphatase activity increased
significantly (P < 0.02) in lupus T cells cultured for 8 h in estradiol
containing medium. Reverse transcription and polymerase chain amplification
revealed that ER-beta and ER-alpha were expressed in female and male T cells from
SLE patients and normal controls. However, calcineurin steady-state mRNA levels
were unaffected by estradiol in cultured T cells from male SLE patients and
normal male and female controls. These data indicate that estrogen, bound to the
ER, evokes a direct increase in calcineurin expression in T cells from female
lupus patients. This gender-specific response suggests that ER function is
altered in women with the female predominant autoimmune disease, SLE.
PMID- 10779405
TI - The induction of EAE is only partially dependent on TNF receptor signaling but
requires the IL-1 type I receptor.
AB - Experimental autoimmune encephalomyelitis develops in mice immunized with CNS
antigens. To elucidate the role that specific proinflammatory cytokines play in
the induction of this process we examined the development of EAE in mice with
targeted disruptions of the TNF p55 or p75 or the IL-1 p80 receptors. EAE
developed in mice with either one or both TNF receptors deleted although the
onset of disease in mice with the p55 receptor deleted was delayed. However, mice
with a deletion of the IL-1 p80 receptor failed to develop any inflammatory
lesions in the CNS or evidence of clinical EAE. Thus we conclude that TNF or its
receptors contribute to, but are not necessary for, the induction of EAE while
the IL-1 p80 receptor is absolutely required. The p55 TNF receptor plays a role
in determining the onset of disease and its severity.
PMID- 10779407
TI - Immunochemical characterization of purified human oxidized low-density
lipoprotein antibodies.
AB - The goal of this study was to characterize the isotypes and reactivity of human
autoantibodies to copper oxidized LDL (oxLDL). Forty-six purified oxLDL
antibodies contained immunoglobulins of the three major isotypes, with a
predominance of IgG, subclasses 1 and 3. These IgG isotypes are known to interact
with FcRgammaI and to activate the complement system and thus are potentially
able to activate macrophages and cause foam cell formation. The same purified
antibodies were tested for cross-reactivity with malondialdehyde (MDA)-, glycated
(Glyc)-, and native (n)LDL and cardiolipin. Absorption with oxLDL resulted in a
decrease of reactivity of 77.2 +/- 4.7%. Absorption with MDA-LDL resulted in a
wider range of reduction of reactivity values, ranging from 50 to 87%, possibly
reflecting differences in the degree of MDA modification. Absorption with Glyc-
and nLDL caused a minor decrease in the reactivity of antibodies to oxLDL (5.9 +/
7.1 and 6.8 +/- 6. 4%, respectively), comparable to the reduction of reactivity
(2.1 +/- 4.0%) measured after absorption with transferrin, an irrelevant protein
used as a negative control. These results suggest that oxLDL antibodies recognize
primarily MDA epitopes. To determine whether purified oxLDL antibodies also
recognize other epitopes known to be generated during copper oxidation of LDL,
such as 4-hydroxynonenal (HNE)- and N(epsilon)(carboxymethyl)-lysine (CML), two
additional sets of experiments were carried out. First, we monitored the
formation of CML-, MDA-lysine, and HNE-lysine at different times during copper
oxidation of two LDL pools. Both pools showed simultaneous increases in protein
modification, as indicated by increasing fluorescence emission at 430 nm, and in
immunoreactivity with oxLDL antibodies, coinciding closely with MDA modification
of lysine groups. Second, we assessed whether the reactivity of oxLDL antibodies
could be blocked by absorption with CML- or HNE-LDL. HNE-LDL did not react with
isolated oxLDL antibodies. Highly modified CML-LDL (>90% of lysine residues
modified) reduced the reactivity of oxLDL antibodies, but only by 25.5%. Finally,
we investigated the possible cross-reactivity of oxLDL antibodies with
cardiolipin. Seventeen purified oxLDL antibodies were used in this study, which
showed that absorption with oxLDL or nLDL did not affect their reactivity with
immobilized cardiolipin.
PMID- 10779408
TI - Glycyrrhizin improves the resistance of MAIDS mice to opportunistic infection of
Candida albicans through the modulation of MAIDS-associated type 2 T cell
responses.
AB - Compared with normal mice, MAIDS mice (mice infected with LP-BM5 murine leukemia
virus) exhibited an increase up to 100 times greater in susceptibility to
infection with Candida albicans. The impaired resistance of MAIDS mice to the
infection was recovered to levels observed in normal mice by the administration
of glycyrrhizin (GR), an active component of licorice roots. MAIDS mice
inoculated with CD4(+) T cells from GR-treated mice were also resistant to C.
albicans infection. Normal mice inoculated with CD4(+) T helper type 2 cells (Th2
cells) from MAIDS mice were susceptible to C. albicans infection at the same
levels shown in MAIDS mice. The susceptibility of normal mice inoculated with
type 2 T cells was reversible by (i) administration of GR and (ii) inoculation of
CD4(+) T cells from GR-treated mice and injection of a mixture of mAbs targeted
against type 2 cytokines (IL-4 and IL-10). Type 2 cytokines were not detected in
sera of MAIDS mice inoculated with CD4(+) T cells from GR-treated mice, while
they were present in sera of MAIDS mice treated with saline. These results
suggest that, by inducing CD4(+) T cells which suppress type 2 cytokine
production by MAIDS-associated Th2 cells, GR improves the resistance of MAIDS
mice to C. albicans infection.
PMID- 10779409
TI - Role for interferon-gamma in rat strains with different susceptibility to
experimental autoimmune myasthenia gravis.
AB - Experimental autoimmune myasthenia gravis (EAMG) is caused by autoantibodies
against the nicotinic acetylcholine receptor (AChR) at the neuromuscular
postsynaptic membrane and represents an animal model of myasthenia gravis in
human. Recent studies highlighted the roles of TH1 cytokines (IFN-gamma, IL-12),
rather than TH2 cytokines (IL-4), in the pathogenesis of EAMG by using homozygous
(-/-) knockout mice with an EAMG-susceptible genetic background. To further
evaluate a role for IFN-gamma, we injected recombinant rat IFN-gamma (rrIFN
gamma) at the time of immunization with AChR in complete Freund's adjuvant to
EAMG-susceptible Lewis rats and EAMG-resistant Wistar Furth (WF) rats. RrIFN
gamma enhanced Lewis rat EAMG. The exacerbated muscular weakness was associated
with higher levels of anti-AChR IgG and enhanced TNF-alpha responses. Anti-AChR
IgG antibody levels were augmented to a similar extent as in Lewis rats, however,
the identical immunization and IFN-gamma injection induced only mild and
transient EAMG in WF rats due to the default TH3 phenotype development and
inherent low TH1 responses. We conclude that IFN-gamma plays a major role in the
pathogenesis of EAMG in the Lewis rat, but fails to break disease resistance in
the WF rat.
PMID- 10779410
TI - Urine levels of CD46 (membrane cofactor protein) are increased in patients with
glomerular diseases.
AB - Soluble membrane cofactor protein (MCP, CD46) has not been detected by
conventional ELISA in human urine. Here, we established a highly sensitive assay
method for determination of urinary MCP (uMCP) using monoclonal antibody-coated
paramagnetic beads. This method enabled us to detect less than 0.05 ng/ml of
purified membrane and recombinant soluble MCP, a sensitivity 10-fold higher than
that of conventional ELISA. In normal subjects, the levels of uMCP were <0. 05
ng/ml. The levels of uMCP were elevated in patients with IgA nephropathy and more
prominently in patients with rapidly progressive glomerulonephritis. The levels
of uMCP were correlated significantly with those of serum MCP (sMCP) and N-acetyl
beta-glucosaminidase and nonsignificantly with those of beta(2)-microglobulin,
total urine protein, or serum creatinine. The properties of uMCP were
inconsistent with those of the reported sMCP, since uMCP showed three bands on
SDS-PAGE/immunoblotting with molecular mass profiles different from those of
sMCP. uMCP exhibited factor I cofactor activity for cleavage of C3b comparable to
that of sMCP. The origin of uMCP, however, remains to be determined. These
results, taken together with the parameter correlation profiles, suggested that
uMCP is secreted or produced secondary to tubular or glomerular damage. The
physiological role and clinical significance of uMCP are now within the scope of
our investigation by establishment of this assay.
PMID- 10779411
TI - Structural basis for selectivity of a small molecule, S1-binding, submicromolar
inhibitor of urokinase-type plasminogen activator.
AB - BACKGROUND: Urokinase-type plasminogen activator (uPA) is a protease associated
with tumor metastasis and invasion. Inhibitors of uPA may have potential as drugs
for prostate, breast and other cancers. Therapeutically useful inhibitors must be
selective for uPA and not appreciably inhibit the related, and structurally and
functionally similar enzyme, tissue-type plasminogen activator (tPA), involved in
the vital blood-clotting cascade. RESULTS: We produced mutagenically
deglycosylated low molecular weight uPA and determined the crystal structure of
its complex with 4-iodobenzo[b]thiophene 2-carboxamidine (K(i) = 0.21 +/- 0.02
microM). To probe the structural determinants of the affinity and selectivity of
this inhibitor for uPA we also determined the structures of its trypsin and
thrombin complexes, of apo-trypsin, apo-thrombin and apo-factor Xa, and of uPA,
trypsin and thrombin bound by compounds that are less effective uPA inhibitors,
benzo[b]thiophene-2-carboxamidine, thieno[2,3-b]-pyridine-2-carboxamidine and
benzamidine. The K(i) values of each inhibitor toward uPA, tPA, trypsin,
tryptase, thrombin and factor Xa were determined and compared. One selectivity
determinant of the benzo[b]thiophene-2-carboxamidines for uPA involves a hydrogen
bond at the S1 site to Ogamma(Ser190) that is absent in the Ala190 proteases,
tPA, thrombin and factor Xa. Other subtle differences in the architecture of the
S1 site also influence inhibitor affinity and enzyme-bound structure.
CONCLUSIONS: Subtle structural differences in the S1 site of uPA compared with
that of related proteases, which result in part from the presence of a serine
residue at position 190, account for the selectivity of small thiophene-2
carboxamidines for uPA, and afford a framework for structure-based design of
small, potent, selective uPA inhibitors.
PMID- 10779412
TI - Antagonists of protein-protein interactions.
AB - Protein-protein interactions are often attractive, but not straightforward,
targets for disease therapy. Two strategies for identifying inhibitors of these
interactions, peptide phage display and high-throughput screening, have recently
shown new promise.
PMID- 10779413
TI - The advantages of ambiguous orientation.
AB - Recent studies have revealed that although it is possible for certain
transcription factors to bind in an orientated fashion on DNA, they have not
evolved to do so. Rather, they rely on contacts with other proteins to precisely
define their mode of binding.
PMID- 10779414
TI - Potentiation of CD3-induced expression of the linker for activation of T cells
(LAT) by the calcineurin inhibitors cyclosporin A and FK506.
AB - The activation of blood cells, including T cells, triggers intracellular signals
that control the expression of critical molecules, including cytokines and
cytokine receptors. We show that T-cell receptor (TCR) ligation increases the
cellular level of the protein linker for activation of T cells (LAT), a molecule
critical for T-cell development and function. T-cell activation increased LAT
messenger RNA, as determined by reverse transcription-polymerase chain reaction
and by Northern blotting. The TCR-induced increase in LAT expression involved the
activation of the serine/threonine kinases PKC and MEK, because inhibitors of
these kinases blocked the increase in LAT. Accordingly, the PKC activator phorbol
myristate acetate up-regulated LAT expression. Strikingly, the calcineurin
inhibitors cyclosporin A (CsA) and FK506 strongly potentiated TCR-induced LAT
expression, suggesting that the activation of calcineurin following TCR ligation
negatively regulates LAT expression. Accordingly, Ca(++ )ionophores, which can
activate calcineurin by increasing intracellular Ca(++), blocked the TCR-induced
increase in cellular LAT. CsA and FK506 blocked the Ca(++ )ionophores' inhibitory
effect on LAT expression. Notably, CsA and FK506 preferentially up-regulated TCR
induced LAT expression; under the same conditions, these compounds did not
increase the expression of 14 other molecules that previously had been implicated
in T-cell activation. These data show that TCR-induced LAT expression involves
the activation of the PKC-Erk pathway and is negatively regulated by the
activation of calcineurin. Furthermore, the potentiation of TCR-induced LAT
expression by CsA and FK506 suggests that the action of these agents involves up
regulating the cellular level of critical signaling molecules. These findings may
have important therapeutic implications. (Blood. 2000;95:2733-2741)
PMID- 10779415
TI - Specific and rapid induction of the proapoptotic protein Hrk after growth factor
withdrawal in hematopoietic progenitor cells.
AB - Hrk is a newly described proapoptotic member of the Bcl-2 family that is mainly
expressed in hematopoietic tissues and cultured neurons. In this study we have
examined the expression and activity of Hrk in hematopoietic progenitors. To
address these issues, we used 3 growth factor-dependent murine hematopoietic cell
lines, HCD-57, FDCP-Mix, and FL5.12. The expression of Hrk was undetectable in
cells cultured with growth factors, but it was rapidly up-regulated on growth
factor withdrawal. In contrast, the expression of Bcl-x(L) decreased and that of
proapoptotic Bax, Bad, and Bak was unchanged or down-regulated after removal of
growth factors. This pattern of expression correlated with the induction of
apoptosis. Hrk was also up-regulated in human cell lines and in bone marrow
derived CD34(+) cells cultured in the absence of growth factors. In addition, the
levels of Hrk were up-regulated after treatment with the chemotherapeutic drug
etoposide. Expression of prosurvival Bcl-x(L) or Bcl-2 proteins blocked the
induction of Hrk. Hrk was induced in FDCP-Mix cells treated with ionomicin in the
presence of IL-3, suggesting that cytosolic calcium may regulate the expression
of this proapoptotic protein. Furthermore, ectopic expression of Hrk induced cell
death of hematopoietic progenitors in the presence of IL-3. Thus, Hrk is
specifically and rapidly induced in hematopoietic progenitors after growth factor
deprivation or treatment with chemotherapeutic drugs, and this may be sufficient
to induce apoptosis in these cells. (Blood. 2000;95:2742-2747)
PMID- 10779416
TI - Role of SUMO-1-modified PML in nuclear body formation.
AB - The tumor-suppressive promyelocytic leukemia (PML) protein of acute promyelocytic
leukemia (APL) has served as one of the defining components of a class of
distinctive nuclear bodies (NBs). PML is delocalized from NBs in APL cells and is
degraded in cells infected by several viruses. In these cells, NBs are disrupted,
leading to the aberrant localization of NB proteins. These results have suggested
a critical role for the NB in immune response and tumor suppression and raised
the question of whether PML is crucial for the formation or stability of NB. In
addition, PML is, among other proteins, covalently modified by SUMO-1. However,
the functional relevance of this modification is unclear. Here, we show in
primary PML(-/-) cells of various histologic origins, that in the absence of PML,
several NB proteins such as Sp100, CBP, ISG20, Daxx, and SUMO-1 fail to
accumulate in the NB and acquire aberrant localization patterns. Transfection of
PML in PML(-/-) cells causes the relocalization of NB proteins. By contrast, a
PML mutant that can no longer be modified by SUMO-1 fails to do so and displays
an aberrant nuclear localization pattern. Therefore, PML is required for the
proper formation of the NB. Conjugation to SUMO-1 is a prerequisite for PML to
exert this function. These data shed new light on both the mechanisms underlying
the formation of the NBs and the pathogenesis of APL. (Blood. 2000;95:2748-2752)
PMID- 10779417
TI - The primacy of the gastrointestinal tract as a target organ of acute graft-versus
host disease: rationale for the use of cytokine shields in allogeneic bone marrow
transplantation.
AB - Acute graft-versus-host disease (GVHD), the major complication of allogeneic bone
marrow transplantation (BMT), limits the application of this curative but toxic
therapy. Studies of inflammatory pathways involved in GVHD in animals have shown
that the gastrointestinal (GI) tract plays a major role in the amplification of
systemic disease. Damage to the GI tract increases the translocation of
inflammatory stimuli such as endotoxin, which promotes further inflammation and
additional GI tract damage. The GI tract is therefore critical to the propagation
of the "cytokine storm" characteristic of acute GVHD. Experimental approaches to
the prevention of GVHD include reducing the damage to the GI tract by
fortification of the GI mucosal barrier through novel "cytokine shields" such as
IL-11 or keratinocyte growth factor. Such strategies have reduced GVHD while
preserving a graft-versus-leukemia effect in animal models, and they now deserve
formal testing in carefully designed clinical trials. (Blood. 2000;95:2754-2759)
PMID- 10779418
TI - HTLV-II down-regulates HIV-1 replication in IL-2-stimulated primary PBMC of
coinfected individuals through expression of MIP-1alpha.
AB - The influence of human T-cell leukemia/lymphoma virus type II (HTLV-II) in
individuals also infected with HIV-1 is poorly understood. To evaluate the
reciprocal influence of HTLV-II and HIV-1 infection, primary peripheral blood
mononuclear cell (PBMC) cultures from coinfected individuals were established in
the presence of interleukin 2 (IL-2). In these cultures, the kinetics of HTLV-II
replication always preceded those of HIV-1. Noteworthy, the kinetics of HIV-1
production were inversely correlated to the HTLV-II proviral load in vivo and its
replication ex vivo. These observations suggested a potential interaction between
the 2 retroviruses. In this regard, the levels of IL-2, IL-6, and tumor necrosis
factor-alpha (TNF-alpha) were measured in the same coinfected PBMC cultures.
Endogenous IL-2 was not produced, whereas IL-6 and TNF-alpha were secreted at
levels compatible with their known ability to up-regulate HIV-1 expression. The
HIV-suppressive CC-chemokines RANTES, macrophage inflammatory protein-1alpha (MIP
1alpha), and MIP-1beta were also determined in IL-2-stimulated PBMC cultures. Of
interest, their kinetics and concentrations were inversely related to those of
HIV-1 replication. Experiments were performed in which CD8(+) T cells or PBMCs
from HTLV-II monoinfected individuals were cocultivated with CD4(+) T cells from
HIV-1 monoinfected individuals separated by a semipermeable membrane in the
presence or absence of antichemokine neutralizing antibodies. The results
indicate that HTLV-II can interfere with the replicative potential of HIV-1 by up
regulating viral suppressive CC-chemokines and, in particular, MIP-1alpha. This
study is the first report indicating that HTLV-II can influence HIV replication,
at least in vitro, via up-regulation of HIV-suppressive chemokines. (Blood.
2000;95:2760-2769)
PMID- 10779419
TI - Secondary neoplasms subsequent to Berlin-Frankfurt-Munster therapy of acute
lymphoblastic leukemia in childhood: significantly lower risk without cranial
radiotherapy.
AB - Secondary neoplasms (SNs) represent serious late complications after successful
treatment of malignant diseases. To evaluate the rate and type of SNs after
Berlin-Frankfurt-Munster (BFM) treatment in children with acute lymphoblastic
leukemia (ALL), we analyzed the data from the BFM database and the German
Childhood Cancer Registry (GCCR). Between April 1979 and April 1995, 5006
children with B-precursor or T-ALL were enrolled in 5 ALL-BFM multicenter trials.
The median follow-up time from diagnosis was 5.7 years (range 1.5-18 years). By
December 1997, 52 SNs were documented, including 16 acute myeloid leukemias
(AMLs), 13 neoplasms of the central nervous system (CNS), and 23 other neoplasms.
Compared with the expected numbers estimated from incidence rates derived from
the GCCR, this represented a 14-fold increase for all cancers and a 19-fold
increase for CNS tumors. SNs developed 0.9 to 15 years (median: 6 years) after
the diagnosis of ALL; 46 patients were in first complete remission (CR). The
overall cumulative risk of SNs at 15 years was 3.3% (95% confidence interval
[CI]: 1.6%-5.1%) and 2.9% (95% CI: 1.6%-4.2%) in first CR. The risk was 3.5% (95%
CI: 1.5%-5. 5%) after treatment, including cranial irradiation and significantly
lower in nonirradiated patients: 1.2% (95% CI: 0.2%-2.3%; P =.048). The
development of secondary AML was not associated with the use of any specific
cytotoxic agent. Considering the high-survival rate of this large unselected ALL
cohort, the risk of SN is relatively low, though higher, especially after cranial
irradiation, than in the general population. Long-term follow-up is mandatory,
and further SNs with longer latency periods are to be expected. (Blood.
2000;95:2770-2775)
PMID- 10779420
TI - Safety and efficacy of subcutaneous bolus injection of deferoxamine in adult
patients with iron overload.
AB - We compared 48-hour urinary iron excretion after a twice-daily subcutaneous bolus
injection of deferoxamine and after 12 hours of subcutaneous continuous infusion
of the drug in 27 patients with iron overload (mean age, 55.7 years). In most
patients, the iron overload was due to multiple transfusions administered during
chemotherapy or as part of supportive care for a hematologic or oncologic
disorder. One patient had sickle cell anemia and 1 had hereditary hemochromatosis
and spherocytosis. Similar urinary iron excretion was observed with the 2 methods
of administration; mean +/- SD values were 6935.3 +/- 3832.3 microg/48 hours with
subcutaneous bolus injection and 6630.4 +/- 3606.9 microg/48 hours with
subcutaneous continuous infusion (P =.3). Twenty-six patients (96.3%) chose to
continue therapy with bolus injection. The long-term efficacy of bolus injection
was evaluated by measuring the serum ferritin concentration at regular intervals
for a follow-up time of 20.1 +/- 4.5 months. Ferritin concentration decreased to
below 1000 microg/L in 73% of the patients and to below 500 microg/L in 42% and
became normal in 26%. Best results were obtained in patients who were no longer
receiving blood transfusions when chelation therapy was initiated. Three of 26
patients (11.5%) had mild, transient side effects after bolus injection. Larger
prospective, randomized studies must be conducted before deferoxamine bolus
injection can be routinely recommended for patients with iron overload. (Blood.
2000;95:2776-2779)
PMID- 10779421
TI - Linkage analysis demonstrates that the prothrombin G20210A mutation jointly
influences plasma prothrombin levels and risk of thrombosis.
AB - Association studies suggest that the G20210A mutation (G to A substitution at
nucleotide position 20210) in the prothrombin gene (PT) is associated with
increased plasma prothrombin activity and with increased risk for venous
thromboembolism. To test directly for linkage between this PT variant and plasma
prothrombin activity we performed a family-based study. The G20210A genotypes and
plasma prothrombin activity levels were determined in 435 individuals belonging
to 22 extended Spanish families. The sample was composed of 388 homozygous (G/G)
normal individuals and 43 heterozygote (G/A) and 4 homozygote (A/A) carriers for
the G20210A mutation. The results of variance-component linkage analysis yielded
a highly significant lod score of 3.6 (P = 2.4 x 10(-5)) between this mutation
and a quantitative trait locus (QTL) that influences prothrombin activity.
Importantly, a conditional linkage analysis that simultaneously accounted for
association with the G20210A variant completely eliminated the linkage signal,
which indicates that this mutation affects the function of the prothrombin gene.
Additionally, a bivariate linkage analysis of plasma prothrombin activity and
thrombosis significantly improved the linkage signal for prothrombin activity
(lod score = 4.7; P = 1.5 x 10(-6)) and provided strong evidence that this QTL
has a pleiotropic effect on the risk of thrombosis (lod score = 2.43; P =.0004).
These results represent the first direct genetic evidence that a QTL in the PT
gene influences prothrombin activity levels and susceptibility to thrombosis and
strongly support the conclusion that G20210A is a functional polymorphism.
(Blood. 2000;95:2780-2785)
PMID- 10779423
TI - Improvement of erythropoiesis in beta-thalassemic mice by continuous
erythropoietin delivery from muscle.
AB - beta-Thalassemias are highly prevalent genetic disorders that can cause severe
hemolytic anemia. The main pathophysiologic feature of beta-thalassemia is the
accumulation of unpaired alpha-globin chains in erythrocyte precursors and red
blood cells (RBCs). This accumulation alters cell membrane function and results
in early cell destruction and ineffective erythropoiesis. Correction of globin
chain imbalance through the induction of fetal hemoglobin (HbF) synthesis is a
tentative therapeutic approach for this class of diseases. In short-term in vitro
or in vivo assays, recombinant human erythropoietin increases the frequency of
erythroid precursors programmed to HbF in humans and to beta-minor globin in
mice. In contrast, long-term treatment of beta-thalassemic patients did not
induce HbF significantly. We took advantage of highly efficient adeno-associated
virus-mediated (AAV-mediated) gene transfer into mouse muscle to induce a robust
and sustained secretion of mouse erythropoietin in beta-thalassemic mice, which
represent a suitable model for human beta-thalassemia intermedia. A 1-year follow
up of 12 treated animals showed a stable correction of anemia associated with
improved RBC morphology, increased beta-minor globin synthesis, and decreased
amounts of alpha-globin chains bound to erythrocyte membranes. More effective
erythropoiesis probably accounted for a reduction of erythroid cell
proliferation, as shown by decreased proportions of circulating reticulocytes and
by reduced iron 59 ((59)Fe) incorporation into erythroid tissues. This study
indicates that the continuous delivery of high amounts of autologous
erythropoietin induced a sustained stimulation of beta-minor globin synthesis and
a stable improvement of erythropoiesis in the beta-thalassemic mouse model.
(Blood. 2000;95:2793-2798)
PMID- 10779422
TI - Autoimmune hemolytic anemia in chronic lymphocytic leukemia: clinical,
therapeutic, and prognostic features.
AB - Fifty-two cases of autoimmune hemolytic anemia (AHA) were observed within a
series of 1203 patients (4.3%) with chronic lymphocytic leukemia (CLL) followed
at a single institution. Nineteen were observed at the time of CLL diagnosis and
33 during the clinical follow-up. Ninety percent of the patients with CLL/AHA
showed active CLL and 25% had been treated previously. The antierythrocyte
autoantibody (AeAb) was an IgG in 87% of cases and an IgM in 13%. A lymphocyte
count more than 60 x 10(9)/L (P <.00001), age above 65 years (P <.01), and male
gender (P <.01) emerged as independent parameters that correlated significantly
with an increased rate of AHA at CLL diagnosis. Patients previously treated with
chlorambucil (CB) plus prednisone (PDN) and with fludarabine plus PDN showed a
similar rate of AHA (1.8% and 2.5%, respectively). After steroid therapy
associated with CB in case of active CLL, 70% of patients achieved the complete
disappearance of the AeAb. The actuarial AHA relapse-free survival probability
was 54% at 5 years and the median survival probability after AHA was 41 months.
Infections represented the main cause of morbidity and mortality. IgG AHA and the
occurrence of AHA at the same time of CLL diagnosis emerged as independent
factors significantly correlated with a better survival probability of AHA/CLL
patients. Taken together, this study indicates that in CLL, AHA is a rare event
with no independent effect on survival for which steroids, associated with CB if
required, and a careful management of infections may successfully control the 2
conditions. Cooperative studies are needed to better define the optimal steroid
schedule and the therapeutic role of other immunosuppressive agents and
splenectomy. (Blood. 2000;95:2786-2792)
PMID- 10779424
TI - Correction of the coagulation defect in hemophilia A mice through factor VIII
expression in skin.
AB - To test the hypothesis that factor VIII expressed in the epidermis can correct
hemophilia A, we generated transgenic mice in a factor VIII-deficient background
that express human factor VIII under control of the involucrin promoter. Mice
from 5 transgenic lines had both phenotypic correction and plasma factor VIII
activity. In addition to the skin, however, some factor VIII expression was
detected in other tissues that have stratified squamous epithelia. To determine
whether an exclusively cutaneous source of factor VIII could correct factor VIII
deficiency, we grafted skin explants from transgenic mice onto mice that are
double knockouts for the factor VIII and RAG-1 genes. Two graft recipients had
plasma factor VIII activity of 4% to 20% of normal and improved whole blood
clotting compared with factor VIII-deficient mice. Thus, expression of factor
VIII from the epidermis can correct hemophilia A mice, thereby supporting the
feasibility of cutaneous gene therapy for systemic disease. (Blood. 2000;95:2799
2805)
PMID- 10779426
TI - Isolation and characterization of human CD34(-)Lin(-) and CD34(+)Lin(-)
hematopoietic stem cells using cell surface markers AC133 and CD7.
AB - Recent evidence indicates that human hematopoietic stem cell properties can be
found among cells lacking CD34 and lineage commitment markers (CD34(-)Lin(-)). A
major barrier in the further characterization of human CD34(-) stem cells is the
inability to detect this population using in vitro assays because these cells
only demonstrate hematopoietic activity in vivo. Using cell surface markers AC133
and CD7, subfractions were isolated within CD34(-)CD38(-)Lin(-) and CD34(+)CD38(
)Lin(-) cells derived from human cord blood. Although the majority of CD34(
)CD38(-)Lin(-) cells lack AC133 and express CD7, an extremely rare population of
AC133(+)CD7(-) cells was identified at a frequency of 0.2%. Surprisingly, these
AC133(+)CD7(-) cells were highly enriched for progenitor activity at a frequency
equivalent to purified fractions of CD34(+) stem cells, and they were the only
subset among the CD34(-)CD38(-)Lin(-) population capable of giving rise to
CD34(+) cells in defined liquid cultures. Human cells were detected in the bone
marrow of non-obese/severe combined immunodeficiency (NOD/SCID) mice 8 weeks
after transplantation of ex vivo-cultured AC133(+)CD7(-) cells isolated from the
CD34(-)CD38(-)Lin(-) population, whereas 400-fold greater numbers of the AC133(
)CD7(-) subset had no engraftment ability. These studies provide novel insights
into the hierarchical relationship of the human stem cell compartment by
identifying a rare population of primitive human CD34(-) cells that are
detectable after transplantation in vivo, enriched for in vitro clonogenic
capacity, and capable of differentiation into CD34(+) cells. (Blood. 2000;95:2813
2820)
PMID- 10779425
TI - Generation of T cells from adult human hematopoietic stem cells and progenitors
in a fetal thymic organ culture system: stimulation by tumor necrosis factor
alpha.
AB - To investigate the T-lymphopoietic capacity of human adult bone marrow (ABM)
hematopoietic progenitor cells, CD34+Lin-, CD34+CD38+, and CD34++CD38- cells were
cultured in a severe combined immunodeficient (SCID) mouse fetal thymic organ
culture (FTOC). Direct seeding of these progenitors resulted in a moderate to
severe cell loss, particularly for the CD34++CD38- cell fraction, and T cells
could only be generated from the CD34+Lin- fraction. Preincubation for 36 hours
with interleukin-3 (IL-3) and stem cell factor (SCF) led to an improved cell
survival and proliferation, although T-cell development was seen only in the
CD34+Lin- fraction. Addition of tumor necrosis factor (TNF)-alpha to IL-3 + SCF
supplemented preincubation medium resulted in optimal cell survival, cell
proliferation. and T-cell generation of all 3 cell fractions. The TNF-alpha
effect resulted in an up-regulation of CD127 (ie, the IL-7 receptor alpha-chain)
in a small subset of the CD34+ cells. No evidence could be generated to support
the possibility that TNF-alpha inhibits a cell population that suppresses T-cell
differentiation. A quantitatively different T-cell generation potency was still
seen between the 3 subpopulations: CD34+Lin- (100% success rate) > CD34+CD38+
(66%) > CD34++CD38- (25%). These data contrast with our previous findings using
fetal liver and cord blood progenitors, which readily differentiate into T
lymphocytes in FTOC, even without prestimulation with cytokines. Our results
demonstrate that adult CD34++CD38- cells, known to contain hematopoietic stem
cells, can differentiate into T-lymphocytes and that a significant difference
exists in T-lymphopoietic activity of stem cells derived from ontogenetically
different sources. (Blood. 2000;95:2806-2812)
PMID- 10779427
TI - Retinoic acid is a negative regulator for the differentiation of cord blood
derived human mast cell progenitors.
AB - We examined the effects of retinoids on the human mast cell development using a
serum-deprived culture system. When 10-week cultured mast cells derived from
CD34(+) cord blood cells were used as target cells, both all-trans retinoic acid
(ATRA) and 9-cis RA inhibited the progeny generation under stimulation with stem
cell factor (SCF) in a dose-dependent manner (the number of progeny grown by SCF
plus RA at 10(-7) mol/L was one tenth of the value obtained by SCF alone). The
early steps in mast cell development appear to be less sensitive to RA according
to the single CD34(+)c-kit(+) cord blood cell culture study. The optimal
concentration of RAs also reduced the histamine concentration in the cultured
mast cells (3.00 +/- 0.47 pg per cell in SCF alone, 1.44 +/- 0.18 pg per cell in
SCF+ATRA, and 1.41 +/- 0.10 pg per cell in SCF+9-cis RA). RT-PCR analyses showed
the expression of RARalpha, RARbeta, RXRalpha, and RXRbeta messenger ribonucleic
acid (mRNA) in 10-week cultured mast cells. The addition of an RAR-selective
agonist at 10(-10) mol/L to 10(-7) mol/L decreased the number of mast cells grown
in SCF, whereas an RXR-selective agonist at up to 10(-8) mol/L was inactive.
Among RAR subtype selective retinoids used at 10(-9) mol/L to 10(-7) mol/L, only
the RARalpha agonist was equivalent to ATRA at 10(-7) mol/L in its ability to
inhibit mast cell growth. Conversely, the addition of excess concentrations of a
RARalpha antagonist profoundly counteracted the retinoid-mediated suppressive
effects. These results suggest that RA inhibits SCF-dependent differentiation of
human mast cell progenitors through a specific receptor. (Blood. 2000;95:2821
2828)
PMID- 10779428
TI - Effects of cell cycle activation on the short-term engraftment properties of ex
vivo expanded murine hematopoietic cells.
AB - Loss of long-term hematopoietic stem cell function in vitro is associated with
cell cycle progression. To determine whether cytokine-induced proliferation also
limits the rate of short-term engraftment and potential clinical utility of ex
vivo expanded hematopoietic cells, murine Sca-1(+)c-kit(+)Lin(-) cells were
cultured in interleukin-6 (IL-6), IL-11, granulocyte colony-stimulating factor (G
CSF), stem cell factor, flk-2 ligand, and thrombopoietin for 7 days. Cells
amplified 2000-fold were then stained with Hoechst 33342, separated into
G(0)/G(1) (72% +/- 3%) or S/G(2)/M (27% +/- 3%) fractions by flow sorting, and
injected into lethally irradiated mice. Although long-term (more than 6 months)
engraftment of lymphoid and myeloid lineages was greater in primary and secondary
recipients of expanded cells residing in G(0)/G(1) at the time of
transplantation, there were no noted differences in the short-term (less than 6
weeks) recovery kinetics of circulating blood cells. When hematopoietic cells
were expanded in cultures containing the tetrapeptide stem cell inhibitor N
Acetyl-Ser-Asp-Lys-Pro (AcSDKP) to reduce progenitor cycling prior to
transplantation, again there were no differences observed in short-term
reconstitution by inhibited or uninhibited cells. Interestingly, AcSDKP
significantly accelerated engraftment by expanded hematopoietic cells when
administered in vivo at the time of transplantation. Leukocytes recovered to 20%
of normal levels approximately 1 week faster, and thrombocytopenia was largely
abrogated in AcSDKP-treated versus untreated mice. Therefore, while AcSDKP can
accelerate the engraftment of ex vivo expanded hematopoietic progenitors, which
suggests a relatively simple approach to improve their clinical utility, its
effects appear unrelated to cell cycle arrest. (Blood. 2000;95:2829-2837)
PMID- 10779429
TI - REDK, a novel human regulatory erythroid kinase.
AB - We have identified a novel regulatory erythroid kinase (REDK) that is homologous
to a family of dual-specificity kinases. The yeast homolog of REDK negatively
regulates cell division, suggesting a similar function for REDK, which is
primarily localized in the nucleus. REDK is present in hematopoietic tissues,
such as bone marrow and fetal liver, but the RNA is expressed at significant
levels only in erythroid or erythropoietin (EPO)-responsive cells. Two novel
forms of cDNA (long and short) for REDK have been isolated that appear to be
alternative splice products and imply the presence of polypeptides with differing
amino termini. The ratio of short-to-long forms of REDK increases dramatically in
CD34(+) cells cultured with EPO, suggesting differing regulation and function for
each form. REDK is predominantly found in nuclear, rather than cytoplasmic,
protein extracts, and immunoprecipitated REDK is active in phosphorylating
histones H2b, H3, myelin basic protein, and other coimmunoprecipitated proteins.
Antisense REDK oligonucleotides promote erythroid colony formation by human bone
marrow cells, without affecting colony-forming unit (CFU)-GM, CFU-G, or CFU-GEMM
numbers. Maximal numbers of CFU-E and burst-forming unit-erythroid were
increased, and CFU-E displayed increased sensitivity to suboptimal EPO
concentrations. The data indicate that REDK acts as a brake to retard
erythropoiesis. (Blood. 2000;95:2838-2846)
PMID- 10779430
TI - Monocytes express high amounts of Notch and undergo cytokine specific apoptosis
following interaction with the Notch ligand, Delta-1.
AB - Notch signaling has been shown to play a key role in cell fate decisions in
numerous developmental systems. Using a reverse transcriptase-polymerase chain
reaction (RT-PCR) assay, we reported the expression of human Notch-1 in CD34+
progenitors. In this study, we evaluated the expression of human Notch-1 and
Notch-2 protein by hematopoietic cells. In immunofluoresence study, we detected
low amounts of Notch-1 and Notch-2 protein in both CD34+ and CD34+Lin- cells,
high amounts in CD14+ monocytes as well as B and T cells, but no expression in
CD15+ granulocytes. We further found that an immobilized truncated form of the
Notch ligand, Delta-1, induced apoptosis in monocytes in the presence of
macrophage colony-stimulating factor (M-CSF), but not granulocyte-macrophage
colony-stimulating factor (GM-CSF). The widespread expressions of Notch proteins
suggest multiple functions for this receptor during hematopoiesis. These studies
further indicate a novel role for Notch in regulating monocyte survival. (Blood.
2000;95:2847-2854)
PMID- 10779431
TI - Thrombin activatable fibrinolysis inhibitor and the risk for deep vein
thrombosis.
AB - Thrombin activatable fibrinolysis inhibitor (TAFI, or procarboxypeptidase B) is
the precursor of a recently described carboxypeptidase that potently attenuates
fibrinolysis. Therefore, we hypothesized that elevated plasma TAFI levels induce
a hypofibrinolytic state associated with an increased risk for venous thrombosis.
To evaluate this hypothesis, we developed an electroimmunoassay for TAFI antigen
and used this assay to measure TAFI levels in the Leiden Thrombophilia Study, a
case-control study of venous thrombosis in 474 patients with a first deep vein
thrombosis and 474 age- and sex-matched control subjects. In 474 healthy control
subjects, an increase of TAFI with age was observed in women but not in men. Oral
contraceptive use also increased the TAFI concentration. TAFI levels above the
90th percentile of the controls (> 122 U/dL) increased the risk for thrombosis
nearly 2-fold compared with TAFI levels below the 90th percentile (odds ratio,
1.7; 95% confidence interval, 1.1-2.5). Adjustment for various possible
confounders did not materially affect this estimate. These results indicate that
elevated TAFI levels form a mild risk factor for venous thrombosis. Such levels
were found in 9% of healthy controls and in 14% of patients with a first deep
vein thrombosis. Elevated TAFI levels did not enhance the thrombotic risk
associated with factor V Leiden but may interact with high factor VIII levels.
(Blood. 2000;95:2855-2859)
PMID- 10779432
TI - Shortage of circulating naive CD8(+) T cells provides new insights on
immunodeficiency in aging.
AB - Clinical observations indicate that elderly people are prone to severe, often
lethal infectious diseases induced by novel pathogens. Since the ability to mount
primary immune responses relies on the availability of naive T cells, the
circulating naive T-cell reservoir was evaluated throughout the human life span.
Naive T cells were identified as CD95(-) T lymphocytes for their phenotypic and
functional features. Indeed, the lack of CD95 marker is sufficient to identify a
population of naive T cells, as defined by coincidence with previously
characterized CD45RA(+) CD62L(+) T cells. Naive CD95(-) T cells, as expected,
require a costimulatory signal, such as CD28, to optimally proliferate after anti
CD3 stimulation. Cytofluorimetric analysis of circulating T lymphocytes from 120
healthy subjects ranging in age from 18 to 105 years revealed that naive T cells
decreased sharply with age. The younger subjects had a naive T-lymphocyte count
of 825 +/- 48 cells/microL, and the centenarians had a naive T-lymphocyte count
of 177 +/- 28 cells/microL. Surprisingly, the naive T-cell count was lower in
CD8(+) than in CD4(+) subsets at any age, and the oldest individuals were almost
completely depleted of circulating naive CD8(+) T cells (13 +/- 4 cells/microL).
Concomitantly, a progressive expansion of CD28(-) T cells occurs with age, which
can be interpreted as a compensatory mechanism. These data provide new insights
into age-related T-cell-mediated immunodeficiency and reveal some analogies of T
cell dynamics between advanced aging and human immunodeficiency virus (HIV)
infection. In conclusion, the exhaustion of the naive CD8(+) T-cell reservoir,
which has never been reported before, suggests that this T-cell pool is a major
target of the aging process and may define a parameter possibly related to the
life span of humans. (Blood. 2000;95:2860-2868)
PMID- 10779433
TI - Role of IL-16 in delayed-type hypersensitivity reaction.
AB - Interleukin (IL)-16 is a chemoattractant cytokine for CD4(+) leukocytes. Because
delayed-type hypersensitivity (DTH) reaction is mediated by T helper 1 (Th1)
cells and CD4(+) T cells can be chemoattracted by IL-16, we have investigated the
involvement of IL-16 in the DTH reaction. Immunohistochemical analysis revealed
the IL-16 expression in infiltrating cells and epithelial cells in the DTH
footpads. The IL-16 expression was also detected intracellularly in the
infiltrating cells. In addition, markedly increased production of IL-16 was
detected in the DTH footpad extracts, but not in the control footpad extracts, by
an enzyme-linked immunosorbent assay and also by Western blot analysis. The DTH
footpad extracts exhibited a strong chemoattractant activity toward splenic T
cells, which was significantly inhibited by the inclusion of neutralizing
monoclonal antibody (mAb) against IL-16 in the migration assay. Furthermore,
treatment of sensitized mice in vivo with the anti-IL-16 neutralizing mAb
significantly suppressed the footpad swelling induced by an antigen challenge,
together with decreased infiltration of leukocytes including not only CD4(+) T
cells but also CD8(+) T cells and macrophages into the DTH footpads. Decreased
production of macrophage inflammatory protein 1alpha was also observed in the DTH
footpad extracts by the mAb treatment. These results suggest that IL-16 plays an
important role in the recruitment of leukocytes-presumably including antigen
specific Th1 cells, which secrete cytokines and chemokines mediating the
following hypersensitivity reaction after activation by the interaction with
Langerhans cells carrying the antigen-for the elicitation of DTH response.
(Blood. 2000;95:2869-2874)
PMID- 10779434
TI - Nonsteroidal anti-estrogens inhibit the functional differentiation of human
monocyte-derived dendritic cells.
AB - Dendritic cells (DC) are professional antigen-presenting cells with a unique
capacity to initiate and regulate immune responses. Immature CD1a(+) DC can be
cultured from CD14(+) monocytes in the presence of interleukin (IL)-4 and
granulocyte macrophage colony-stimulating factor in vitro. Results of this study
show that the nonsteroidal anti-estrogens toremifene and tamoxifen inhibit this
differentiation. In the presence of anti-estrogens the cells lose CD14
expression, but remain CD1a(-) and clearly have less dendritic processes than
immature DC. Functionally, anti-estrogen-treated cells are inferior to immature
DC in inducing proliferation of allogeneic T cells and in producing IL-12 p70
protein after CD40 ligation. The expression of the costimulatory molecules CD80
and CD86 is differentially regulated by anti-estrogens during DC differentiation.
Furthermore, anti-estrogens are also able to inhibit the terminal maturation of
DC. By inhibiting the functional differentiation of DC, anti-estrogens may have a
role in the treatment and prevention of autoimmune diseases. (Blood. 2000;95:2875
2882)
PMID- 10779435
TI - Killer inhibitory receptor (CD158b) modulates the lytic activity of tumor
specific T lymphocytes infiltrating renal cell carcinomas.
AB - In this study, we showed that renal tumors contain substantial subsets of CD8(+)
p58(+) T cells. From 1 of these tumors, T cells were amplified in mixed
lymphocytes-tumor cell cultures and p58(+) T cells were selected immunologically.
After expansion, phenotypic and functional features of p58(+) and p58(-) T cells
were examined. The p58(+) T cells expressed p58.2 receptor and corresponded to
CD3(+), CD8(+), T-cell receptor (TCR) alpha/beta(+) T cells that were CD56(+) and
CD28(-). Functionally, p58(+) T cells showed a low level of lytic activity
against autologous tumor cells that was dramatically and specifically increased
by anti-p58.2 monoclonal antibody. On the other hand, p58(-) CD8(+) T cells did
not lyse autologous tumor cells and had non-major histocompatibility complex
restricted cytotoxicity against K562 and Daudi cells. A p58(+) cytotoxic T
lymphocyte (CTL) clone (4C7) with the same characteristics as the p58(+) T-cell
line was derived. This CTL clone did not lyse autologous normal B cells but lysed
several HLA-A1(+) renal tumor cell lines. Analysis of TCR repertoire diversity
showed that the p58(+) T-cell line contained 3 TCR rearrangements, whereas the
TCR repertoire of p58(-) T cells was polyclonal. Interestingly, TCR transcripts
of p58(+) T cells and of CTL clone 4C7 were detected as prominent ex vivo in
tumor cells but not in peripheral blood mononuclear cells, suggesting that these
cells are antigen specific and amplified at the tumor site. (Blood. 2000;95:2883
2889)
PMID- 10779436
TI - Defensins are dominant HLA-DR-associated self-peptides from CD34(-) peripheral
blood mononuclear cells of different tumor patients (plasmacytoma, chronic
myeloid leukemia).
AB - The HLA-DR-associated peptides from peripheral blood mononuclear cells of 2
patients with plasmacytoma and 1 with chronic myeloid leukemia were isolated,
identified, and compared. Several were identified as derivatives of the defensin
family. Defensins (or human neutrophil peptides [HNP]) are antimicrobial,
cationic peptides of 29 to 35 amino acids in length and are the major
constituents of the azurophilic granules of human neutrophils. Using peripheral
blood cells from leukapheresis, containing about 90% of polymorphonuclear cells,
we could identify HNP-1, -2, and -4 and propeptides of up to 49 amino acids in
length, eluted from HLA class II molecules. Binding of isolated and synthetic
defensin peptides to various HLA-DR alleles using an in vitro binding/competition
assay based on size exclusion chromatography revealed that defensin may bind into
the peptide-binding groove. In a T-cell competition assay, defensins were able to
reduce the proliferation of an HLA-DR-restricted T-cell line after preincubation
of stimulating cells (CHO-DRB1*0401 transfectants) with defensin. Therefore,
binding of defensins might prevent T-cell recognition of HLA class II molecules
expressed on different blood precursor cells (all of which are "nonprofessional"
antigen-presenting cells) by blocking the HLA peptide-binding groove or,
alternatively, might protect defensin-expressing cells from self-destruction.
(Blood. 2000;95:2890-2896)
PMID- 10779437
TI - P-glycoprotein plays a drug-efflux-independent role in augmenting cell survival
in acute myeloblastic leukemia and is associated with modulation of a
sphingomyelin-ceramide apoptotic pathway.
AB - P-glycoprotein (pgp), which is the product of the MDR1 (multidrug resistance-1)
gene, has an established role as a mediator of cytotoxic drug resistance in acute
myeloid leukemia (AML). To study the role of pgp in mediating apoptosis
resistance in AML cells deprived of serum and growth factors, apoptosis was
quantified by flow cytometry using uptake of the dye 7-amino-actinomycin D (7
AAD) alongside low forward scatter. In pgp+ve primary AML samples, there was a
significant increase in apoptosis in the presence of the pgp-specific antibody
UIC2 (mean increase: 58%; range: 11%-95%; P <. 05). Likewise, apoptosis in growth
factor-deprived TF1 cells cultured for 30 hours increased 2.5-fold in the
presence of 25 microg/mL UIC2. The pgp reversal agent PSC-833 (1 micromol/L)
augmented in vitro apoptosis by a median of 52% in pgp+ve patient samples and to
a comparable degree in 6 pgp-ve samples. To determine whether the sphingomyelin
ceramide (SM-ceramide) pathway of apoptosis occurs in AML blasts in response to
cytotoxic drugs, cells were incubated with daunorubicin at the patient-specific
IC(30) (the concentration of daunorubicin that caused apoptotic cell death in 30%
of cells) in the presence of the ceramide synthase inhibitor fumonisin B1, which
inhibited apoptosis by 18%-81% (median: 40%). Exogenous SM failed to augment
apoptosis induced by growth factor withdrawal in pgp+ve TF1 cells and was
significantly more effective at augmenting apoptosis in pgp-ve patient blasts
(median increase in cell death: 33%; range: 19%-88%) than in pgp+ve samples
(median: 7%; range: 0%-27%; P =.028). Cellular accumulation of exogenous SM was
associated with apoptosis and also occurred in nonapoptotic patient cells treated
with PSC-833. However, this effect was not seen following treatment with the UIC2
antibody. These results indicate that pgp is able to exert a protective effect on
AML cell viability and that this is associated with a reduced effect of exogenous
SM on apoptosis. The pgp reversal agent PSC-833 acts, at least in part, by a pgp
independent mechanism to alter SM distribution and to augment apoptosis induced
in AML cells by serum and growth factor withdrawal. (Blood. 2000;95:2897-2904)
PMID- 10779438
TI - Autocrine nerve growth factor is essential for cell survival and viral maturation
in HHV-8-infected primary effusion lymphoma cells.
AB - High levels of nerve growth factor (NGF) are found in sera from individuals
infected with human herpesvirus 8 (HHV-8). BC-1 and BCBL-1 cells are primary
effusion lymphoma-derived B-cell lines; BC-1 cells are infected by HHV-8 and the
Epstein-Barr virus (EBV), and BCBL-1 cells are infected only by HHV-8. Both cells
express NGF receptors and produce NGF, whereas RAMOS cells (a B-cell line that is
negative for HHV-8 and EBV) express NGF receptors but do not produce detectable
NGF. Neutralization of endogenous NGF results in cell growth inhibition and
apoptosis in BCBL-1 cells and, to a minor extent, in BC-1 cells. When the HHV-8
lytic cycle is induced in BCBL-1 cells by tetradecanoyl phorbol acetate (TPA), an
initial reduction of endogenous NGF production is observed, and many cells
undergo apoptosis. However, at 48 hours, TPA-treated cells produce significantly
more NGF than untreated controls, and a subsequent recovery of cell viability is
observed. Consistent with this finding, the addition of exogenous NGF or anti-NGF
antibodies to TPA-treated cells reduces or increases, respectively, the rate of
apoptosis in response to TPA. Finally, electron microscopy of TPA-treated BCBL-1
cells shows that the addition of exogenous NGF increases the number of cells
producing and releasing complete virions as compared with the controls (25%
versus 5%). On the contrary, NGF neutralization leads to the production of
defective viral progeny in about 2% of cells. These data indicate that NGF is
essential for both cell survival and virus maturation in HHV-8-infected cell
lines. (Blood. 2000;95:2905-2912)
PMID- 10779439
TI - Analysis of the biologic properties of p230 Bcr-Abl reveals unique and
overlapping properties with the oncogenic p185 and p210 Bcr-Abl tyrosine kinases.
AB - The reciprocal translocation between chromosomes 9 and 22 that fuses coding
sequences of the Bcr and Abl genes is responsible for a remarkably diverse group
of hematologic malignancies. A newly described 230-kd form of Bcr-Abl has been
associated with an indolent myeloproliferative syndrome referred to as chronic
neutrophilic leukemia. We have cloned the corresponding gene and examined the
biologic and biochemical properties of p230 Bcr-Abl after retroviral-mediated
gene transfer into hematopoietic cell lines and primary bone marrow cells. p230
Bcr-Abl-expressing 32D myeloid cells were fully growth factor-independent and
activated similar signal transduction pathways as the well-characterized p210 and
p185 forms of Bcr-Abl. In contrast, primary mouse bone marrow cells expressing
p230 required exogenous hematopoietic growth factors for optimal growth, whereas
p185- and p210-expressing cells were independent of growth factors. The 3 Bcr-Abl
proteins exerted different effects on differentiation of bone marrow cells. p185
induced outgrowth of lymphoid precursors capable of tumor formation in
immunodeficient mice. In contrast, p210- and p230-expressing bone marrow cells
caused limited outgrowth of lymphoid precursors that failed to form tumors in
immunodeficient mice. Removal of cytokines and autologous stroma from Bcr-Abl
expressing bone marrow cultures produced the expansion of distinct lineages by
the various Bcr-Abl proteins. p185 drove expansion of cytokine-independent
lymphoid progenitors, while p210 and p230 generated cytokine-independent
monocyte/myeloid cells. These findings suggest that the different Bcr-Abl fusion
proteins drive the expansion of different hematopoietic populations, which may
explain the association of the various Bcr-Abl oncoproteins with different
spectra of human leukemias. (Blood. 2000;95:2913-2921)
PMID- 10779440
TI - Variable heavy chain gene analysis of follicular lymphomas: correlation between
heavy chain isotype expression and somatic mutation load.
AB - The expansion of follicular lymphomas (FLs) resembles, both morphologically and
functionally, normal germinal center B-cell growth. The tumor cells proliferate
in networks of follicular dendritic cells and are believed to be capable of
somatic hypermutation and isotype switching. To investigate the relation between
somatic mutation and heavy chain isotype expression, we analyzed the variable
heavy (V(H)) chain genes of 30 FL samples of different isotypes. The V(H) genes
of the FLs were heavily mutated (29.3 mutations on average). In addition, isotype
switched lymphomas contained more somatic mutations than immunoglobulin M
positive lymphomas (33.8 mutations per V(H) gene versus 23.0, respectively). In
all but one of the FLs, the ratios of replacement versus silent mutations in the
framework regions were low, independent of the absolute number of somatic
mutations and the level of intraclonal variation. Analysis of relapse samples of
4 FLs showed no obvious increase in somatic mutation load in most FLs and a
decrease in intraclonal variation in time. In 3 of 4 cases, we obtained evidence
for selection of certain subclones, rather than clonal evolution. Our findings
question if intraclonal variation is always a reflection of ongoing somatic
hypermutation. This may have implications for the concept of antigen-driven
lymphomagenesis. (Blood. 2000;95:2922-2929)
PMID- 10779441
TI - MUC1 dysregulation as the consequence of a t(1;14)(q21;q32) translocation in an
extranodal lymphoma.
AB - Cytogenetic abnormalities at chromosome 1q21 are among the most common lesions in
diffuse large-cell lymphoma and have been associated with a poor prognosis. A
novel cell line, SKI-DLCL-1, was established from ascitic fluid that carries a
t(1;14)(q21;q32) chromosomal translocation. Using pulsed-field gel
electrophoresis, the breakpoint on the IgH locus mapped to a gamma locus between
Calpha(1) and Calpha(2). A cosmid library was prepared from SKI-DLCL-1, and
Cgamma-positive clones spanning the breakpoint were identified by screening with
fluorescence in situ hybridization. The breakpoint occurs 860 bp downstream of
the 3' UTR of the MUC1 gene. The break appears to be a staggered double-strand
break consistent with an error in immunoglobulin class switching. The MUC1 gene
is highly transcribed and translated, and the protein is highly glycosylated. It
is postulated that MUC1 expression is brought under the control of the 3'Ealpha
enhancer. MUC1 lies in a region of chromosome 1 characterized by an unusually
high density of genes, with 7 known genes in a region of approximately 85 kb. To
determine whether there was a pleiotropic effect of the expression of genes in
the region as a consequence of the translocation, the expression of 6 additional
genes was assessed. None of the other genes in this region (CLK2, propin, COTE1,
GBA, metaxin, and thrombospondin 3) are overexpressed in SKI-DLCL-1. Thus, the
translocation t(1;14)(q21;q32) seen in both the primary tumor and the derived
cell line results in the marked overexpression of MUC1 without affecting the
expression of other genes in the region. (Blood. 2000;95:2930-2936)
PMID- 10779442
TI - Loss of heterozygosity on 10q and microsatellite instability in advanced stages
of primary cutaneous T-cell lymphoma and possible association with homozygous
deletion of PTEN.
AB - Previous cytogenetic studies of primary cutaneous T-cell lymphoma (CTCL) were
based on limited numbers of patients and seldom showed consistent nonrandom
chromosomal abnormalities. In this study, 54 tumor DNA samples from patients with
CTCL were analyzed for loss of heterozygosity on 10q. Allelic loss was identified
in 10 samples, all of which were from the 44 patients with mycosis fungoides
(10/44 patients; 23%). Of the patients with allelic loss, 3 were among the 29
patients with early-stage myosis fungoides (T(1) or T(2)) (3/29 patients; 10%),
whereas the other 7 were among the 15 patients with advanced cutaneous disease
(T(3) or T(4)) (7/15 patients; 47%). The overlapping region of deletion was
between 10q23 and 10q24. In addition, microsatellite instability (MSI) was
present in 13 of the 54 samples (24%), 12 from patients with mycosis fungoides
and 1 from a patient with Sezary syndrome. There was also an association between
MSI and disease progression in patients with mycosis fungoides, with 6 of 15
(40%) patients with MSI having advanced cutaneous disease and only 6 of 29 (21%)
having early-stage disease. Samples with allelic loss on 10q were analyzed for
abnormalities of the tumor suppressor gene PTEN (10q23.3). No tumor-specific
mutations were detected, but homozygous deletion was found in 2 patients. Thus,
we found loss of heterozygosity on 10q and MSI in advanced cutaneous stages of
mycosis fungoides. These findings indicate that a tumor suppressor gene or genes
in this region may be associated with disease progression. Furthermore,
abnormalities of PTEN may be important in the pathogenesis of mycosis fungoides,
but our data imply that this gene is rarely inactivated by small deletions or
point mutations. (Blood. 2000;95:2937-2942)
PMID- 10779443
TI - Wiskott-Aldrich syndrome protein is necessary for efficient IgG-mediated
phagocytosis.
AB - Interactions between the Wiskott-Aldrich (WAS) protein (WASp), small GTPases, and
the cytoskeletal organizing complex Arp2/3 appear to be critical for the
transduction of signals from the cell membrane to the actin cytoskeleton in
hematopoietic cells. This study shows that Fcgamma-receptor (FcgammaR)-mediated
phagocytosis is impaired in WASp-deficient peripheral blood monocytes, and that
in macrophages, formation of the actin cup and local recruitment of tyrosine
phosphorylated proteins is markedly attenuated. Results also show that, in normal
macrophages, WASp itself is actively recruited to the cup, suggesting that
assembly of this specialized cytoskeletal structure is dependent on its
expression. (Blood. 2000;95:2943-2946)
PMID- 10779444
TI - Differential expression and regulation of GTPases (RhoA and Rac2) and GDIs (LyGDI
and RhoGDI) in neutrophils from patients with severe congenital neutropenia.
AB - Severe congenital neutropenia (SCN) or Kostmann syndrome is a disorder of
myelopoiesis characterized by a maturation arrest at the stage of promyelocytes
or myelocytes in bone marrow and absolute neutrophil counts less than 200/microL
in peripheral blood. Treatment of these patients with granulocyte colony
stimulating factor (G-CSF) leads to a significant increase in circulating
neutrophils and a reduction in infection-related events in more than 95% of the
patients. To date, little is known regarding the underlying pathomechanism of
SCN. G-CSF-induced neutrophils of patients with SCN are functionally defective
(eg, chemotaxis, superoxide anion generation, Ca(++ )mobilization). Two guanosine
triphosphatases (GTPases), Rac2 and RhoA, were described to be involved in many
neutrophil functions. The expression of these GTPases and their regulation in
patients' neutrophils were of interest. This study determined that the guanosine
diphosphate (GDP)-dissociation inhibitor RhoGDI is overexpressed at the protein
level in patients' neutrophils and that overexpression is a result of G-CSF
treatment. RhoA and LyGDI are expressed at similar levels, whereas Rac2 shows a
decreased expression. In addition, association of Rac2 and RhoGDI or LyGDI is
abrogated or not detectable based on the low Rac2 expression in patients'
neutrophils. (Blood. 2000;95:2947-2953)
PMID- 10779445
TI - Importance of L-selectin-dependent leukocyte-leukocyte interactions in human
whole blood.
AB - The objective of this study was to investigate whether leukocytes could be
recruited by rolling leukocytes in a human whole blood model system. In all
experiments, either neutrophils, whole blood, or diluted blood was perfused over
immobilized E-selectin. With isolated neutrophils (2 x 10(5)/mL), the free
flowing neutrophils were captured by attached neutrophils to form secondary
interactions that resulted in lines of rolling leukocytes. These secondary
tethers accounted for 50% to 60% of all interactions and were eliminated by an L
selectin antibody, which also eliminated the lines of rolling leukocytes.
Perfusion of whole blood or diluted blood revealed no lines of rolling
leukocytes. The addition of red blood cells to isolated neutrophils either in a
1000:1 or a 10:1 ratio also inhibited lines of rolling leukocytes. Leukocytes
were fluorescently labeled with rhodamine-6G so that leukocyte-leukocyte
interactions could be studied in whole blood. A small number of secondary tethers
(less than 20%) occurred and could be reduced by more than 80% with an L-selectin
antibody. However, the overall impact on leukocyte recruitment was negligible.
Similar experiments were performed using murine whole blood or isolated murine
leukocytes. In the absence of red blood cells, murine leukocytes also formed
lines of rolling leukocytes on E-selectin, and secondary tethers accounted for
50% of total interactions. However, when murine blood (diluted 1:5 with buffer)
was perfused over E-selectin, secondary tethers accounted for only 13% of total
interactions. These interactions were completely absent when blood was used from
L-selectin-deficient mice. These data demonstrate for the first time that the
importance of L-selectin-dependent leukocyte-leukocyte interactions is greatly
reduced in whole blood and does not enhance overall recruitment of leukocytes in
this physiologic milieu. (Blood. 2000;95:2954-2959)
PMID- 10779446
TI - Intracellular iron status as a hallmark of mammalian cell susceptibility to
oxidative stress: a study of L5178Y mouse lymphoma cell lines differentially
sensitive to H(2)O(2).
AB - The redox properties of iron make this metal a key participant in oxygen-mediated
toxicity. Accordingly, L5178Y (LY) mouse lymphoma cell lines, which display a
unique inverse cross-sensitivity to ionizing radiation (IR) and hydrogen peroxide
(H(2)O(2)), are a suitable model for the study of possible differences in the
constitutive control of intracellular iron availability. We report here that the
level of iron in the cytosolic labile iron pool (LIP), ie, potentially active in
the Fenton reaction, is more than 3-fold higher in IR-resistant, H(2)O(2)
sensitive (LY-R) cells than in IR-sensitive, H(2)O(2)-resistant (LY-S) cells.
This difference is associated with markedly greater content of ferritin H
subunits (H-Ft) in LY-S than in LY-R cells. Our results show that different
expression of H-Ft in LY cells is a consequence of an up-regulation of H-Ft mRNA
in the LY-S mutant cell line. In contrast, posttranscriptional control of iron
metabolism mediated by iron-responsive element-iron regulatory proteins (IRPs)
interaction is similar in the 2 cell lines, although IRP1 protein levels in iron
rich LY-R cells are twice those in iron-deficient LY-S cells. In showing that LY
cell lines exhibit 2 different patterns of intracellular iron regulation, our
results highlight both the role of high LIP in the establishment of pro-oxidant
status in mammalian cells and the antioxidant role of ferritin. (Blood.
2000;95:2960-2966)
PMID- 10779447
TI - Selectively increased growth of fetal hemoglobin-expressing adult erythroid
progenitors after brief treatment of early progenitors with transforming growth
factor beta.
AB - We have studied the effect of transforming growth factor beta (TGFbeta) on
erythropoiesis in cultures from adult peripheral blood, using flow cytometric
enumeration of fetal hemoglobin (HbF)-containing cells. TGFbeta caused a dramatic
increase in the proportions of cells that accumulated HbF together with adult
hemoglobin (HbA) (F+A+ cells). This highly significant (P <.0001) increase in F+
cell proportion was achieved by TGFbeta treatment during the first 4 days of
culture and was sustained during further culture expansion in the absence of
TGFbeta. The increase in F+ cell proportions did not depend on the cytokine
combination (EPO+SCF+IL3, EPO+SCF, EPO+IL3, SCF+IL3) used during the phase of
TGFbeta treatment. Increased F+ cell proportions were paralleled by an increased
molecular ratio of HbF/ HbF+ HbA, measured by cation exchange high-performance
liquid chromatography (HPLC). In addition to the effect on F+ cell proportions,
TGFbeta caused a dramatic increase in overall cell division potential. By the
time cultures reached terminal growth arrest (12-14 days in controls and 18-26
days after TGFbeta), the overall numbers of F+ cells produced per initially
seeded clonogenic cell was approximately 10 times higher in the TGFbeta-treated
cultures than in the controls. We propose to investigate whether the TGFbeta
induced increase in relative and absolute numbers of nucleated F+ cells, as
demonstrated in vitro, can be translated into increased F+ erythrocytes in vivo,
allowing therapeutic application for some beta-hemoglobinopathies. (Blood.
2000;95:2967-2974)
PMID- 10779448
TI - The assessment of serum nontransferrin-bound iron in chelation therapy and iron
supplementation.
AB - Nontransferrin-bound iron (NTBI) appears in the serum of individuals with iron
overload and in a variety of other pathologic conditions. Because NTBI
constitutes a labile form of iron, it might underlie some of the biologic damage
associated with iron overload. We have developed a simple method for NTBI
determination, which operates in a 96-well enzyme-linked immunosorbent assay
format with sensitivity comparable to that of previous assays. A weak ligand,
oxalic acid, mobilizes the NTBI and mediates its transfer to the iron chelator
deferoxamine (DFO) immobilized on the plate. The amount of DFO-bound iron,
originating from NTBI, is quantitatively revealed in a fluorescence plate reader
by the fluorescent metallosensor calcein. No NTBI is found in normal sera because
transferrin-bound iron is not detected in the assay. Thalassemic sera contained
NTBI in 80% of the cases (range, 0.9-12.8 micromol/L). In patients given
intravenous infusions of DFO, NTBI initially became undetectable due to the
presence of DFO in the sera, but reappeared in 55% of the cases within an hour of
cessation of the DFO infusion. This apparent rebound was attributable to the loss
of DFO from the circulation and the possibility that a major portion of NTBI was
not mobilized by DFO. NTBI was also found in patients with end-stage renal
disease who were treated for anemia with intravenous iron supplements and in
patients with hereditary hemochromatosis, at respective frequencies of 22% and
69%. The availability of a simple assay for monitoring NTBI could provide a
useful index of iron status during chelation and supplementation treatments.
(Blood. 2000;95:2975-2982)
PMID- 10779449
TI - Effects of erythropoietin on platelet reactivity and thrombopoiesis in humans.
AB - A recent study in dogs suggested that erythropoietin (EPO) not only promotes the
synthesis of increased numbers of reticulated platelets but that these newly
produced platelets are hyperreactive compared with controls. Because of the
increasing use of EPO in the perioperative setting, we characterized the effects
of EPO on platelet reactivity in healthy human volunteers. In a randomized,
controlled trial, we studied the effects of EPO on platelet reactivity,
thrombopoiesis, and endothelial activation in circumstances similar to those of
autologous blood donation. Thirty healthy male volunteers received placebo or EPO
(100 or 500 U/kg of body weight given intravenously) three times a week for 2
weeks and underwent phlebotomy on days 8 and 15. Thrombin receptor-activating
peptide induced expression of P-selectin, and CD63 increased 2- to 3-fold during
EPO treatment. The enhanced platelet reactivity was also reflected by a 50%
increase in soluble P-selectin in plasma. Plasma E-selectin levels increased in a
dose-dependent fashion by more than 100% during EPO treatment, indicating
substantial activation of endothelial cells. A 10% to 20% increase in platelet
counts was observed in both EPO groups on day 5. In the placebo group, platelets
increased only several days after the first phlebotomy. The increase in platelet
counts was not reflected by changes in the amounts of reticulated platelets or
circulating progenitor cells. In summary, we found that EPO markedly enhances
endothelial activation and platelet reactivity, which may adversely affect
patients at cardiovascular risk. However, the increased platelet reactivity could
be exploited in patients with platelet dysfunction. (Blood. 2000;95:2983-2989)
PMID- 10779451
TI - Circulation online only : april 25, 2000
PMID- 10779450
TI - Quantitative measure of c-abl and p15 methylation in chronic myelogenous
leukemia: biological implications.
AB - We used a sensitive, quantitative bisulfite PCR assay, methylation sensitive
single nucleotide primer extension (Ms-SNuPE), to measure methylation of the 5'
CpG islands of c-abl and p15 in chronic myelogenous leukemia (CML) patients
during progression. We found that the Pa promoter of c-abl was methylated in 81%
(17/21) of the white blood cells (WBCs) of CML patients, which correlates with
previous reports. In contrast, WBCs from healthy donors, acute myelogenous
leukemias, acute lymphocytic leukemias, and myelodysplastic syndromes were
unmethylated at the c-abl Pa promoter locus. We also observed p15
hypermethylation in 24% (8/34) of CML cases. Methylation of the p15 but not c-abl
Pa promoters was associated with CML progression (P = 0.047 vs 0.46), and the two
events were independently acquired. We conclude that de novo methylation of c-abl
and p15 both occur in CML, and analysis of DNA methylation changes using the
bisulfite-based MS-SNuPE assay allows both a sensitive and quantitative
assessment of these molecular events compared to other methods currently
utilized. (Blood. 2000;95:2990-2992)
PMID- 10779452
TI - Severe aortic stenosis with low systolic gradient:the good and bad news.
PMID- 10779453
TI - Intracoronary beta-radiation therapy inhibits recurrence of in-stent restenosis.
AB - BACKGROUND: Intracoronary gamma-radiation therapy reduces recurrent in-stent
restenosis (ISR). This study, BETA WRIST (Washington Radiation for In-Stent
restenosis Trial) was designed to examine the efficacy and safety of the beta
emitter 90-yttrium for the prevention of recurrent ISR. METHODS AND RESULTS: A
total of 50 consecutive patients with ISR in native coronaries underwent
percutaneous transluminal coronary angioplasty, laser angioplasty, rotational
atherectomy, and/or stent implantation. Afterward, a segmented balloon catheter
was positioned and automatically loaded with a 90-yttrium, 0.014-inch source wire
that was 29 mm in length to deliver a dose of 20.6 Gy at 1.0 mm from the balloon
surface. In 17 patients, manual stepping of the radiation catheter was necessary
for lesions >25 mm in length. The radiation was delivered successfully to all
patients, with a mean dwell time of 3.0+/-0.4 minutes. Fractionation of the dose
due to ischemia was required in 11 patients. At 6 months, the binary angiographic
restenosis rate was 22%, the target lesion revascularization rate was 26%, and
the target vessel revascularization rate was 34%; all rates were significantly
lower than those of the placebo group of gamma-WRIST. CONCLUSIONS: beta-Radiation
with a 90-yttrium source used as adjunct therapy for patients with ISR results in
a lower-than-expected rate of angiographic and clinical restenosis.
PMID- 10779454
TI - Prognostic impact of coronary vasodilator dysfunction on adverse long-term
outcome of coronary heart disease.
AB - BACKGROUND: Endothelial vasodilator dysfunction is a characteristic feature of
patients at risk for coronary atherosclerosis. Therefore, we prospectively
investigated whether coronary endothelial dysfunction predicts disease
progression and cardiovascular event rates. METHODS AND RESULTS: Coronary
vasoreactivity was assessed in 147 patients using the endothelium-dependent
dilator acetylcholine, sympathetic activation by cold pressor testing, dilator
responses to increased blood flow, and dilation in response to nitroglycerin.
Cardiovascular events (cardiovascular death, unstable angina, myocardial
infarction, percutaneous transluminal coronary angioplasty, coronary bypass
grafting, ischemic stroke, or peripheral artery revascularization) served as
outcome variables over a median follow-up period of 7.7 years. Patients suffering
from cardiovascular events during follow-up (n=16) had significantly increased
vasoconstrictor responses to acetylcholine infusion (P=0. 009) and cold pressor
testing (P=0.002), as well as significantly blunted vasodilator responses to
increased blood flow (P<0.001) and the intracoronary injection of nitroglycerin
(P=0.001). Impaired endothelial and endothelium-independent coronary
vasoreactivity were associated with a significantly higher incidence of
cardiovascular events by Kaplan-Meier analysis. By multivariate analysis, all
tests of coronary vasoreactivity were significant, independent predictors of a
poor prognosis, even after adjustment for traditional cardiovascular risk factors
or the presence of atherosclerosis itself. CONCLUSIONS: Coronary endothelial
vasodilator dysfunction predicts long-term atherosclerotic disease progression
and cardiovascular event rates. Thus, the assessment of coronary endothelial
vasoreactivity can provide pivotal information as both a diagnostic and
prognostic tool in patients at risk for coronary heart disease.
PMID- 10779455
TI - Elevated HDL cholesterol is a risk factor for ischemic heart disease in white
women when caused by a common mutation in the cholesteryl ester transfer protein
gene.
AB - BACKGROUND: The level of HDL cholesterol is inversely related to the risk of
ischemic heart disease. METHODS AND RESULTS: In 9168 women and men from a general
population and 946 women and men with ischemic heart disease (all white), we
tested the hypothesis that the Ile405Val mutation in the cholesteryl ester
transfer protein gene (CETP) affects HDL cholesterol levels and the risk of
ischemic heart disease. The relative frequencies of Ile/Ile, Ile/Val, and Val/Val
carriers were 0.46, 0.43, and 0.11 for both women and men. Women with these 3
genotypes had mean HDL cholesterol levels of 1.68, 1.75, and 1.82 mmol/L,
respectively (P<0.001, ANOVA), as well as a significant decrease in the ratio of
total to HDL cholesterol (P=0. 002, ANOVA). On multiple logistic regression
analysis, women not treated with hormone replacement therapy who were
heterozygous or homozygous for Val405 had a 1.4-fold (95% CI 1.0 to 1.9) to 2.1
fold (95% CI 1.3 to 3.4) increase in the risk of ischemic heart disease. No
significant associations were found in men. CONCLUSIONS: Increased HDL
cholesterol levels caused by mutations in CETP are associated with an increased
risk of ischemic heart disease in white women.
PMID- 10779456
TI - Relationship of socioeconomic status to the incidence and prehospital, 28-day,
and 1-year mortality rates of acute coronary events in the FINMONICA myocardial
infarction register study.
AB - BACKGROUND: Low socioeconomic status (SES) is associated with increased coronary
heart disease mortality rates. There are, however, very little data on the
relation of SES to the incidence, recurrence, and prognosis of myocardial
infarction (MI) events. METHODS AND RESULTS: The FINMONICA MI Register recorded
detailed information on all MI events among men and women aged 35 to 64 years in
3 areas of Finland during the period of 1983 to 1992. We carried out a record
linkage of the MI register data with files of Statistics Finland to obtain
information on indicators of SES, such as taxable income and education, for each
individual who is registered. In the analyses, income was grouped into 3
categories (low, middle, and high), and education was grouped into 2 categories
(basic and secondary or higher). Among men with their first MI event (n=6485),
the adjusted incidence rate ratios were 1.67 (95% CI 1.57 to 1.78) and 1.84 (95%
CI 1.73 to 1.95) in the low- and middle-income categories compared with the high
income category. For 28-day mortality rates, the corresponding rate ratios were
3.18 (95% CI 2.82 to 3.58) and 2.33 (95% CI 2.03 to 2.68). Significant
differentials were observed for prehospital mortality rates, and they remained
similar up to 1 year after the MI. Findings among the women were consistent with
those among the men. CONCLUSIONS: The excess coronary heart disease mortality and
morbidity rates among persons with low SES are considerable in Finland. To bring
the mortality rates of low- and middle-SES groups down to the level of that of
the high-SES group constitutes a major public health challenge.
PMID- 10779457
TI - Social support, depression, and mortality during the first year after myocardial
infarction.
AB - BACKGROUND: We previously reported that depression after myocardial infarction
(MI) increases the long-term risk of cardiac mortality. Other research suggests
that social support may also influence prognosis. This article examines the
interrelationships between baseline depression and social support in terms of
cardiac prognosis and changes in depression symptoms over the first post-MI year.
METHODS AND RESULTS: For this study, 887 patients completed the Beck Depression
Inventory (BDI) and the Perceived Social Support Scale (PSSS) at about 7 days
after MI. Some 32% had BDIs > or =10, indicating mild to moderate depression. One
year survival status was determined for all patients. Follow-up interviews,
including the BDI, were conducted with 89% of survivors. There were 39 deaths (35
cardiac). Elevated BDI scores were related to cardiac mortality (P=0.0006), but
PSSS scores and other measures of social support were not. There was a
significant interaction between depression and the PSSS (P=0. 016). The
relationship between depression and cardiac mortality decreased with increasing
support. Furthermore, residual change score analysis revealed that among 1-year
survivors who had been depressed at baseline, higher baseline social support was
related to more improvement in depression symptoms than expected. CONCLUSIONS:
Post-MI depression is a predictor of 1-year cardiac mortality, but social support
is not directly related to survival. However, very high levels of support appear
to buffer the impact of depression on mortality. Furthermore, high levels of
support predict improvements in depression symptoms over the first post-MI year
in depressed patients. High levels of support may protect patients from the
negative prognostic consequences of depression because of improvements in
depression symptoms.
PMID- 10779458
TI - Nitric oxide spares myocardial oxygen consumption through attenuation of
contractile response to beta-adrenergic stimulation in patients with idiopathic
dilated cardiomyopathy.
AB - BACKGROUND: The results of recent studies suggest that NO synthase may increase
in the failing myocardium and that NO modulates the myocardial contractile
response to beta-adrenergic stimulation. However, there are few data regarding
the physiological role of NO in patients with heart failure. The aim of the
present study was to address the role of NO in left ventricular (LV) contractile
response to beta-adrenergic stimulation and corresponding oxygen expenditure in
human heart failure. METHODS AND RESULTS: We studied 15 patients with heart
failure due to idiopathic dilated cardiomyopathy (mean ejection fraction 0.33).
We examined LV contractility (E(max), the slope of end-systolic pressure-volume
relation), LV external work (EW), myocardial oxygen consumption (MVO(2)), and
mechanical efficiency (measured as EW/MVO(2)) with the use of conductance and
coronary sinus thermodilution catheters before and during dobutamine (DOB)
infusion via a peripheral vein (4. 8+/-0.3 microg. kg(-1). min(-1) IV). Heart
rate was kept constant with atrial pacing. We carried out a similar protocol
during the intracoronary infusion of the NO synthase inhibitor N(G)-monomethyl-L
arginine (L-NMMA; 200 micromol). DOB increased E(max), EW, and MVO(2) (by 77+/
17%, 39+/-5%, and 21+/-5%, respectively), leading to an increase in mechanical
efficiency (25.4+/-3.1% to 29.6+/-4.1%). L-NMMA alone did not significantly
change these variables. Although the concurrent infusion of DOB with L-NMMA
increased E(max), EW, and MVO(2) (by 140+/-21%, 64+/-9%, and 35+/-5%,
respectively) more than DOB alone, mechanical efficiency did not increase further
(24.3+/-3.3% to 29.5+/-4.5%) because EW and MVO(2) increased in parallel.
Conclusions-These data suggest that in patients with idiopathic dilated
cardiomyopathy, endogenous NO spares MVO(2) through attenuation of LV contractile
response to beta-adrenergic stimulation while maintaining LV energy-converting
efficiency.
PMID- 10779459
TI - Frequency and clinical implications of fluid dynamically significant diffuse
coronary artery disease manifest as graded, longitudinal, base-to-apex myocardial
perfusion abnormalities by noninvasive positron emission tomography.
AB - BACKGROUND: Diffuse coronary atherosclerosis is the substrate for plaque rupture
and coronary events. Therefore, in patients with mild arteriographic coronary
artery disease without significant segmental dipyridamole-induced myocardial
perfusion defects, we tested the hypothesis that fluid dynamically significant
diffuse coronary artery narrowing is frequently manifest as a graded,
longitudinal, base-to-apex myocardial perfusion abnormality by noninvasive PET.
METHODS AND RESULTS: In this study, 1001 patients with documented coronary artery
disease by coronary arteriography showing any visible coronary artery narrowing
underwent rest-dipyridamole PET perfusion imaging. Quantitative severity of
dipyridamole-induced, circumscribed, segmental PET perfusion defects was
objectively measured by automated software as the minimum quadrant average
relative activity indicating localized flow limiting stenoses. Quantitative
severity of the graded, longitudinal, base-to-apex myocardial perfusion gradient
indicating fluid dynamic effects of diffuse coronary artery narrowing was
objectively measured by automated software as the spatial slope of relative
activity along the cardiac longitudinal axis. CONCLUSIONS: In patients with mild
arteriographic disease without statistically significant dipyridamole-induced
segmental myocardial perfusion defects caused by flow-limiting stenoses compared
with normal control subjects, there was a graded, longitudinal, base-to-apex
myocardial perfusion gradient significantly different from normal control
subjects (P=0. 001) that was also observed for moderate to severe dipyridamole
induced segmental perfusion defects (P=0.0001), indicating diffuse disease
underlying segmental perfusion defects; 43% of patients with or without segmental
perfusion defects demonstrated graded, longitudinal, base-to-apex perfusion
abnormalities beyond +/-2 SD of normal control subjects, indicating diffuse
coronary arterial narrowing by noninvasive PET perfusion imaging.
PMID- 10779460
TI - Severe aortic stenosis with low transvalvular gradient and severe left
ventricular dysfunction:result of aortic valve replacement in 52 patients.
AB - BACKGROUND: The outcome of aortic valve replacement in patients with severe
aortic stenosis, low transvalvular gradient, and severe left ventricular
dysfunction is not well known. METHODS AND RESULTS: Between 1985 and 1995, 52
patients with left ventricular ejection fraction (EF) < or =35% and aortic
stenosis with transvalvular mean gradient <30 mm Hg underwent aortic valve
replacement. The mean (+/-SD) preoperative characteristics included EF, 26+/-8%;
aortic valve mean gradient, 23+/-4 mm Hg; aortic valve area, 0.7+/-0.2 cm(2); and
cardiac output, 3.7+/-1.2 L/min. Simultaneous coronary artery bypass graft
surgery was performed in 32 patients (62%). Perioperative (30-day) mortality was
21% (11 of 52 patients). Ten additional patients died during follow-up. Advanced
age (P=0.048) and small aortic prosthesis size (P=0.03) were significant
predictors of hospital mortality by univariate analysis. By multivariate
analysis, the only predictor of surgical mortality was smaller prosthesis size.
The only predictor of postoperative survival was improvement in postoperative
functional class (P=0.04). Postoperative functional improvement occurred in most
patients. Postoperative EF was assessed in 93% of survivors; 74% demonstrated
improvement. Positive change in EF was related to smaller preoperative aortic
valve area and female sex. CONCLUSIONS: Despite severe left ventricular
dysfunction, low transvalvular mean gradient, and increased operative mortality,
aortic valve replacement was associated with improved functional status.
Postoperative survival was related to younger patient age and larger aortic
prosthesis size, and medium-term survival was related to improved postoperative
functional class.
PMID- 10779461
TI - Rate of change in aortic valve area during a cardiac cycle can predict the rate
of hemodynamic progression of aortic stenosis.
AB - BACKGROUND: The ability to predict the rate of hemodynamic progression in an
individual patient with valvular aortic stenosis has been elusive. The purpose of
the present study was to evaluate whether the rate of change in aortic valve area
(AVA) measured during the ejection phase of a cardiac cycle predicts the rate of
hemodynamic progression in patients with asymptomatic aortic stenosis. METHODS
AND RESULTS: In 84 adults with initially asymptomatic aortic stenosis and a
baseline AVA of > or =0.9 cm(2), annual echocardiographic data were obtained
prospectively (mean follow-up 2.8+/-1.3 years). With the initial echocardiogram,
the ratio of AVA measured at mid-acceleration and mid-deceleration to the AVA at
peak velocity was calculated. The primary outcome variable was the annual rate of
change in AVA (rate of progression), with rate of progression classified as rapid
(a reduction in AVA of > or =0.2 cm(2)/y) or slow (<0.2 cm(2)/y). Rapid
progression was significantly associated with an AVA ratio of > or =1.25
(P=0.004, risk ratio 3.1, 95% CI 1.2 to 7.9). The sensitivity, specificity, and
positive predictive value of AVA ratio of > or =1.25 for the prediction o rapid
progression of valvar aortic stenosis was 64%, 72%, and 80% respectively. The
decrease in ejection fraction measured from the initial to final echocardiogram
was small but greater for patients with an AVA ratio of > or =1.25 (-4+/-7%
versus +2+/-7%, P<0.001). CONCLUSIONS: A flow-dependent change in AVA can be
measured during a routine transthoracic echocardiographic study. The rate of
change in AVA is an additional measure of disease severity and may be used to
predict an individual's risk for subsequent rapid disease progression.
PMID- 10779462
TI - A method for determining the reference effective flow areas for mechanical heart
valve prostheses: in vitro validation studies.
AB - BACKGROUND: The anatomic opening area (AOA) is usually reported as the primary
index of mechanical heart valve function. Because flow contracts immediately
distal to an orifice as a result of the vena contracta effect, AOA may not be a
good measure of true effective flow area. METHODS AND RESULTS: Laser flow imaging
was used to visualize the contraction in the jet flow stream as it passed through
bileaflet mechanical valves under steady and pulsatile conditions. Such
visualization allowed clear measurement of the individual vena contracta areas
(VCAs) of the 3 valve orifices. VCAs for side orifices were larger (94+/-2% of
AOA) than those through the central orifice (34+/-8%). Formation of large radial
vortices around the leaflet tips constricted the central orifice flow stream and
appeared to be the main reason for smaller central VCA. Total VCA remained
constant until approximately 0.5 orifice diameters ( approximately 1.0 cm)
downstream, beyond which cross-sectional area increased as a result of
entrainment of receiving chamber flow. Total VCA was larger for steady flow
(89.6+/-2.7% of AOA) than for pulsatile flow (76.3+/-5.0% of AOA). CONCLUSIONS:
This study further clarifies flow dynamics through bileaflet mechanical valves
and provides previously unavailable reference information on VCAs for these
valves. Such information should aid clinicians in explaining Doppler-derived and
catheter-measured pressure discrepancies, validating clinical techniques for
quantifying effective flow areas, and optimizing valve size for implantation. The
method should also be useful for comparative studies of different valve designs.
PMID- 10779463
TI - Relationship between regional cardiac hyperinnervation and ventricular
arrhythmia.
AB - BACKGROUND: Sympathetic nerve activity is known to be important in ventricular
arrhythmogenesis, but there is little information on the relation between the
distribution of cardiac sympathetic nerves and the occurrence of spontaneous
ventricular arrhythmias in humans. METHODS AND RESULTS: We studied 53 native
hearts of transplant recipients, 5 hearts obtained at autopsy of patients who
died of noncardiac causes, and 7 ventricular tissues that had been surgically
resected from the origin of ventricular tachycardia. The history was reviewed to
determine the presence (group 1A) or absence (group 1B) of spontaneous
ventricular arrhythmias. Immunocytochemical staining for S100 protein,
neurofilament protein, tyrosine hydroxylase, and protein gene product 9.5 was
performed to study the distribution and the density of sympathetic nerves. The
average left ventricular ejection fraction was 0.22+/-0.07. A total of 30
patients had documented ventricular arrhythmias, including ventricular
tachycardia and sudden cardiac death. A regional increase in sympathetic nerves
was observed around the diseased myocardium and blood vessels in all 30 hearts.
The density of nerve fibers as determined morphometrically was significantly
higher in group 1A patients (total nerve number 19.6+/-11.2/mm(2), total nerve
length 3.3+/-3.0 mm/mm(2)) than in group 1B patients (total nerve number 13.5+/
6.1/mm(2), total nerve length 2.0+/-1.1 mm/mm(2), P<0. 05 and P<0.01,
respectively). CONCLUSIONS: There is an association between a history of
spontaneous ventricular arrhythmia and an increased density of sympathetic nerves
in patients with severe heart failure. These findings suggest that abnormally
increased postinjury sympathetic nerve density may be in part responsible for the
occurrence of ventricular arrhythmia and sudden cardiac death in these patients.
PMID- 10779464
TI - Endovascular irradiation from beta-particle-emitting gold stents results in
increased neointima formation in a porcine restenosis model.
AB - BACKGROUND: Recent studies have shown that ionizing radiation reduces neointima
formation after balloon angioplasty and stent implantation in experimental models
of restenosis and first clinical trials. The objective of this study was to
determine the dose distribution of a new beta-particle-emitting radioactive gold
stent and to evaluate the dose-dependent vascular response in the coronary
overstretch pig model. METHODS AND RESULTS: Sixteen Gottinger minipigs underwent
placement of 11 nonradioactive and 36 beta-particle-emitting stents with activity
levels of 10.4+/-0.6, 14.9+/-2.4, 22.8+/-1.3, 35.8+/-2. 8, and 55.4+/-5.3 microCi
of (198)Au. Three months after implantation, the percent area stenosis,
neointimal thickness, neointimal area, and vessel injury were analyzed by
quantitative histomorphometry. The lifetime radiation doses at a depth of 1 mm
were 3.3+/-0.2, 4.7+/-0.5, 7.2+/-0.4, 11.4+/-0.9, and 17.6+/-1.7 Gy for the
different activity groups. No dose-response relationship was observed in the
radioactive stents with respect to percent area stenosis (P=0.297), mean
neointimal thickness (P=0.82), or mean neointimal area (P=0.65). Significantly
lower neointima formation and less luminal narrowing was seen in the control
group than in the beta-particle-emitting stents (P<0.001). Multilinear regression
analysis revealed that only radioactivity made a significant independent
contribution to the degree of percent area stenosis (P<0. 001). CONCLUSIONS:
Neointima formation in pigs is markedly increased by beta-particle-emitting
stents with (198)Au as the radioisotope. This study provides evidence that
dosages of 3 to 18 Gy of low-dose-rate beta-particle irradiation via endovascular
stents cause pronounced luminal narrowing in the animal model at 3 months.
PMID- 10779465
TI - Modulation of functionally active endothelin-converting enzyme by chronic neutral
endopeptidase inhibition in experimental atherosclerosis.
AB - BACKGROUND: Endothelin-converting enzyme-1 (ECE-1) processes big endothelin-1 (ET
1) to ET-1, a peptide implicated in atheroma formation. ECE-1 exists in 2
isoforms (ECE-1alpha and ECE-1beta), the result of alternative splicing of a
common gene. Neutral endopeptidase (NEP) is a genetically distinct
metallopeptidase that degrades the natriuretic peptides. These peptides mediate
antiproliferative and vasodilating actions. We sought to demonstrate the
distribution of the 2 ECE-1 isoforms in experimental atherosclerosis, to
determine the effects of chronic NEP-I on plasma cGMP concentrations, vascular
wall ECE-1 activity, and ET-1 concentration, and to correlate these actions with
atheroma formation. Our hypothesis was that chronic NEP-I, in association with
augmented cGMP, would inhibit ECE-1 conversion of big ET-1 to active ET-1, thus
reducing tissue ET-1 concentrations and associated atheroma formation. METHODS
AND RESULTS: Cholesterol-fed New Zealand White rabbits (n=8, 1% cholesterol diet)
and NEP-I-treated cholesterol-fed New Zealand White rabbits (n=8; candoxatril, 30
mg/kg per day, Pfizer) were euthanized after 8 weeks of feeding. ECE-1alpha and
ECE-1beta immunoreactivity was present in the aortas of both groups. Compared
with control values, plasma cGMP concentrations were increased (2.8+/-0.6 versus
8.4+/-1.2 pmol/mL, P<0.05), ECE-1 activity was attenuated (68+/-3% versus 32+/
8%, P<0. 05), aortic tissue ET-1 concentrations were reduced (4.6+/-0.5 versus
3.2+/-0.3 pg/mg protein, P<0.05), and atheroma formation was attenuated (62+/-6%
versus 34+/-5%, P<0.01) by NEP-I. CONCLUSIONS: These studies suggest that ECE-1
is present and functionally active in the vascular wall in atherosclerosis.
Inhibition of ECE-1 by NEP-I represents a novel approach to interruption of the
endothelin system in this cardiovascular disease state.
PMID- 10779467
TI - Application of cDNA microarrays in determining molecular phenotype in cardiac
growth, development, and response to injury.
AB - BACKGROUND: Normal myocardial development and the tissue response to cardiac
stress are accompanied by marked changes in gene expression; however, the extent
of these changes and their significance remain to be fully explored. We used cDNA
microarrays for gene expression profiling in rat cardiac tissue samples to study
developmental transitions and the response to myocardial infarction (MI). METHODS
AND RESULTS: Microarrays with rat cDNAs for 86 known genes and 989 anonymous
cDNAs obtained by molecular subtraction (representational difference analysis) of
mRNA from sham-operated and 6-week post-MI samples were used in 2-color
hybridization experiments. Twelve known genes previously associated with
myocardial development were identified together with 10 uncharacterized expressed
sequence tags and 36 genes not previously associated with cardiac development.
After MI, genes associated with myocardial stress and wound healing exhibited
differences in magnitude and expression kinetics, and 14 genes not previously
associated with MI were identified. In situ hybridization revealed mRNA
localization characteristic of wound healing and vascular and cardiomyocyte
reactivity. CONCLUSIONS: Tissue analysis of gene expression with cDNA microarrays
provides a measure of transcriptional or posttranscriptional regulation and
cellular recruitment. Our results demonstrate the complexity of gene regulation
in the developing myocardium and show that cDNA microarrays can be used to
monitor the evolution of the cardiac stress-inducible phenotype.
PMID- 10779466
TI - Nitric oxide modulates expression of cell cycle regulatory proteins: a cytostatic
strategy for inhibition of human vascular smooth muscle cell proliferation.
AB - BACKGROUND: We examined the effect of NO on the proliferation and cell cycle
regulation of human aortic vascular smooth muscle cells (VSMCs). METHODS AND
RESULTS: The NO donor diethylenetriamineNONOate (10(-5) to 10(-3) mol/L)
inhibited proliferation in response to 10% fetal calf serum (FCS) and 100 ng/mL
platelet-derived growth factor-BB in a concentration-dependent manner. This
effect was not observed with disintegrated diethylenetriamineNONOate or with the
parent compound, diethylenetriamine. Adenoviral transfection of endothelial NO
synthase (NOS) inhibited proliferation in response to FCS, which was prevented
with N(G)-nitro-L-arginine methyl ester. NOS overexpression did not inhibit
proliferation in response to platelet-derived growth factor, although the
transfection efficiency and protein expression were similar to those of FCS
stimulated cells. Nitrate release was selectively enhanced from FCS-treated
cells, indicating that NOS was activated by FCS only. NO caused G(1) cell cycle
arrest. Cytotoxicity was determined with trypan blue exclusion, and apoptosis was
assessed with DNA fragmentation. Cyclin-dependent kinase 2 expression level,
threonine phosphorylation, and kinase activity were inhibited. Cyclin A
expression was blunted, whereas cyclin E remained unchanged. p21 expression was
induced, and p27 remained unaltered. The effect on cyclin A and p21 started
within 6 hours and preceded the changes in cell cycle distribution. Proliferation
in response to 10% FCS was barely inhibited with 8-bromo-cGMP (10(-3) mol/L) but
was blunted with both forskolin and 8-bromo-cAMP. Proliferation in response to 2%
FCS was inhibited with 8-bromo-cGMP, but it did not mimic the cell cycle effects
of NO. CONCLUSIONS: NO inhibits VSMC proliferation by specifically changing the
expression and activity of cell cycle regulatory proteins, which may occur
independent of cGMP. Adenoviral overexpression of endothelial NOS represents a
cytostatic strategy for gene therapy of vascular disease.
PMID- 10779468
TI - Basic fibroblast growth factor increases tissue factor expression in circulating
monocytes and in vascular wall.
AB - BACKGROUND: Basic fibroblast growth factor (bFGF) promotes vascular repair and
angiogenesis and can induce in vitro tissue factor (TF), a potent agent
initiating thrombogenesis, which probably plays a role in angiogenesis. We
investigated whether bFGF administration induced TF expression by monocytes and
vascular cells. METHODS AND RESULTS: We studied TF expression in normally fed
(n=16) and cholesterol-fed (2% for 6 weeks, n=16) rabbits. Animals were then
randomized to receive intravenous bFGF (2.5 microg twice weekly for 3 weeks) or
saline injections. TF expression was evaluated in mononuclear cells from arterial
blood and in aortic sections by an immunohistochemical assay using a monoclonal
anti-rabbit TF antibody (activator protein 1). Monocyte TF expression was
increased by bFGF administration in both normal and hypercholesterolemic rabbits
(129+/-45 versus 19+/-3 mU TF/1000 monocytes, P<0.05, and 31+/-12 versus 7+/-1 mU
TF/1000 monocytes, P<0.005, respectively) and was further increased by
stimulation of monocytes by endotoxin in vitro. TF expression was lower in
hypercholesterolemic rabbits than in normal rabbits. In the media of the vascular
wall, bFGF induced strong TF expression in normal rabbits and only weak TF
expression in hypercholesterolemic ones. CONCLUSIONS: This study demonstrates
that systemic administration of bFGF induces an impressive increase of TF
expression in circulating monocytes and in the vascular wall in normal and to a
lower extent in hypercholesterolemic rabbits. The significance of this
observation in terms of inducing thrombosis in vivo needs clarification.
PMID- 10779469
TI - Short-term effects of rapid pacing on mRNA level of voltage-dependent K(+)
channels in rat atrium: electrical remodeling in paroxysmal atrial tachycardia.
AB - BACKGROUND: Atrial fibrillation causes electrophysiological changes of the
atrium, thereby facilitating its maintenance. Although the expression of ion
channels is modulated in chronic atrial fibrillation, it is yet unknown whether
paroxysmal atrial fibrillation can also lead to electrical remodeling by
affecting gene expression. METHODS AND RESULTS: To examine the short-term effects
of rapid pacing on the mRNA level of voltage-dependent K(+) channels, high-rate
atrial pacing was performed in Sprague-Dawley rat hearts. Total RNA was prepared
from the atrial appendages from 0 to 8 hours after the onset of pacing, and mRNA
levels of Kv1.2, Kv1. 4, Kv1.5, Kv2.1, Kv4.2, Kv4.3, erg, KvLQT1, and minK were
determined by RNase protection assay. Among these 9 genes, the mRNA level of the
Kv1.5 channel immediately and transiently increased, with bimodal peaks at 0.5
and 2 hours after the onset of pacing. Conversely, the pacing gradually and
progressively decreased the mRNA levels of the Kv4.2 and Kv4.3 channels. The
increase of Kv1.5 and the decrease of Kv4.2 and Kv4.3 mRNA levels were both rate
dependent. In correspondence with the changes in the mRNA level, Kv1. 5 channel
protein transiently increased in the membrane fraction of the atrium during a 2-
to 8-hour pacing period. Electrophysiological findings that the shortening of the
action potential produced by 4-hour pacing was almost abolished by a low
concentration of 4-aminopyridine implied that the increased Kv1.5 protein was
functioning. CONCLUSIONS: Even short-term high-rate atrial excitation could
differentially alter the mRNA levels of Kv1.5, Kv4.2, and Kv4.3 in a rate
dependent manner. In particular, increased Kv1.5 gene expression, having a
transient nature, implied the possible biochemical electrical remodeling unique
to paroxysmal tachycardia.
PMID- 10779471
TI - Images in cardiovascular medicine. Differential color imaging technique of
helical CT angiography in the diagnosis of total anomalous pulmonary venous
drainage.
PMID- 10779470
TI - The US healthcare system 2010: problems, principles, and potential solutions.
PMID- 10779472
TI - Cardiac fibroma resulting in fatal ventricular arrhythmia.
PMID- 10779473
TI - Hyperhomocysteinemia, MTHFR, and risk of vascular disease.
PMID- 10779474
TI - Methylenetetrahydrofolate reductase gene and coronary artery disease.
PMID- 10779475
TI - Repeated administration of vasopressin but not epinephrine maintains coronary
perfusion pressure after early and late administration during prolonged
cardiopulmonary resuscitation in pigs.
PMID- 10779476
TI - Right bundle-branch block, ST-segment elevation, and sudden death.
PMID- 10779477
TI - Psychological factors and ischemic heart disease.
PMID- 10779478
TI - A biologist's view of the Drosophila genome annotation assessment project.
PMID- 10779479
TI - Gene-finding approaches for eukaryotes.
PMID- 10779480
TI - Powers and pitfalls in sequence analysis: the 70% hurdle.
PMID- 10779481
TI - Evolution and variation of the yeast (Saccharomyces) genome.
AB - In this review we describe the role of the yeast Saccharomyces in the development
of human societies including the use of this organism in the making of wine,
bread, beer, and distilled beverages. We also discuss the tremendous diversity of
yeast found in natural (i.e., noninoculated) wine fermentations and the
scientific uses of yeast over the past 60 years. In conclusion, we present ideas
on the model of "genome renewal" and the use of this model to explain the mode by
which yeast has evolved and how diversity can be generated.
PMID- 10779482
TI - Frequent human genomic DNA transduction driven by LINE-1 retrotransposition.
AB - Human L1 retrotransposons can produce DNA transduction events in which unique DNA
segments downstream of L1 elements are mobilized as part of aberrant
retrotransposition events. That L1s are capable of carrying out such a reaction
in tissue culture cells was elegantly demonstrated. Using bioinformatic
approaches to analyze the structures of L1 element target site duplications and
flanking sequence features, we provide evidence suggesting that approximately 15%
of full-length L1 elements bear evidence of flanking DNA segment transduction.
Extrapolating these findings to the 600,000 copies of L1 in the genome, we
predict that the amount of DNA transduced by L1 represents approximately 1% of
the genome, a fraction comparable with that occupied by exons.
PMID- 10779483
TI - Large-scale comparison of fungal sequence information: mechanisms of innovation
in Neurospora crassa and gene loss in Saccharomyces cerevisiae.
AB - We report a large-scale comparison of sequence data from the filamentous fungus
Neurospora crassa with the complete genome sequence of Saccharomyces cerevisiae.
N. crassa is considerably more morphologically and developmentally complex than
S. cerevisiae. We found that N. crassa has a much higher proportion of "orphan"
genes than S. cerevisiae, suggesting that its morphological complexity reflects
the acquisition or maintenance of novel genes, consistent with its larger genome.
Our results also indicate the loss of specific genes from S. cerevisiae.
Surprisingly, some of the genes lost from S. cerevisiae are involved in basic
cellular processes, including translation and ion (especially calcium)
homeostasis. Horizontal gene transfer from prokaryotes appears to have played a
relatively modest role in the evolution of the N. crassa genome. Differences in
the overall rate of molecular evolution between N. crassa and S. cerevisiae were
not detected. Our results indicate that the current public sequence databases
have fairly complete samples of gene families with ancient conserved regions,
suggesting that further sequencing will not substantially change the proportion
of genes with homologs among distantly related groups. Models of the evolution of
fungal genomes compatible with these results, and their functional implications,
are discussed.
PMID- 10779484
TI - Systematic management and analysis of yeast gene expression data.
AB - We report steps toward the systematic management, standardization, and analysis
of functional genomics data. We developed the ExpressDB database for yeast RNA
expression data and loaded it with approximately 17.5 million pieces of data
reported by 11 studies with three different kinds of high-throughput RNA assays.
A web-based tool supports queries across the data from these studies. We examined
comparability of data by converting data from 9 studies (217 conditions) into
mRNA relative abundance estimates (ERAs) and by clustering of conditions by ERAs.
We report on generation of ERAs and condition clustering for non-microarray data
(5 studies, 63 conditions) and describe initial attempts to generate microarray
based ERAs (4 studies, 154 conditions), which exhibit increased error, on our web
site http://arep.med.harvard. edu/ExpressDB. We recommend standards for data
reporting, suggest research into improving comparability of microarray data
through quantifying and standardizing control condition RNA populations, and also
suggest research into the calibration of different RNA assays. We introduce a
model for a database that integrates different kinds of functional genomics data,
Biomolecule Interaction, Growth and Expression Database (BIGED).
PMID- 10779485
TI - Congenic mapping of the type 1 diabetes locus, Idd3, to a 780-kb region of mouse
chromosome 3: identification of a candidate segment of ancestral DNA by haplotype
mapping.
AB - Type 1 diabetes in the nonobese diabetic (NOD) mouse arises as a consequence of T
cell-mediated destruction of the insulin-producing beta cells of the pancreas.
Although little is known of the events that initiate and subsequently drive beta
cell destruction it is clear that the entire process is under complex genetic
control. At present 19 loci have been mapped that influence the development of
diabetes either at the level of initiation of insulitis or at the level of
progression from insulitis to overt diabetes, or both. Previously, we have mapped
one of these loci, Idd3, to a 0.35-cM interval on proximal mouse chromosome 3. In
the present study we have narrowed the map position of this locus to an interval
of 0.15 cM by a combination of novel congenic strains and an ancestral haplotype
analysis approach. We have constructed a physical contig in bacterial artificial
chromosome (BAC) clones across the minimal interval. Restriction mapping of the
BAC contig placed the maximum size of the Idd3 interval at 780 kb between the
markers D3Nds36 and D3Nds76. To refine further the Idd3 interval we developed a
series of novel single nucleotide polymorphisms (SNPs) and carried out haplotype
analysis on DNA from mouse strains known to carry either Idd3 susceptibility or
protective alleles. This haplotype analysis identified a 145-kb segment of
ancestral DNA between the microsatellite marker D3Nds6 and the SNP 81.3. One
haplotype of this ancestral segment of DNA is found in mouse strains carrying an
Idd3 susceptibility allele and another is found in mouse strains carrying an Idd3
protective allelle. Within the 780-kb congenically defined interval this 145-kb
segment represents the most likely location for Idd3. The Il2 gene, which encodes
the cytokine interleukin 2 (IL2), maps to this interval and is a strong candidate
for Idd3. To investigate whether sequence variation exists in the promoter region
of the Il2 gene, which might alter its expression, we sequenced the promoter
region of the Il2 gene from mouse strains carrying either an Idd3 susceptibility
or resistance allele. Two sequence variants were identified, neither of which
fell in known regulatory elements within the Il2 promoter. In agreement with this
observation steady-state Il2 mRNA levels showed no variation between susceptible
and resistant mouse strains. These data suggest that the profound protection from
diabetes seen in congenic mice carrying an Idd3 protective allele is unlikely to
be due to differences in the level of expression of the Il2 gene. Instead, all of
the current data support our hypothesis that Idd3 corresponds to amino acid
variation at the amino terminus of Il2.
PMID- 10779486
TI - Construction of a high-resolution 2.5-Mb transcript map of the human 6p21.2
6p21.3 region immediately centromeric of the major histocompatibility complex.
AB - We have constructed a 2.5-Mb physical and transcription map that spans the human
6p21.2-6p21.3 region and includes the centromeric end of the MHC, using a
combination of techniques. In total 88 transcription units including exons,
cDNAs, and cDNA contigs were characterized and 60 were confidently positioned on
the physical map. These include a number of genes encoding nuclear and splicing
factors (Ndr kinase, HSU09564, HSRP20); cell cycle, DNA packaging, and apoptosis
related [p21, HMGI(Y), BAK]; immune response (CSBP, SAPK4); transcription
activators and zinc finger-containing genes (TEF-5, ZNF76); embryogenesis related
(Csa-19); cell signaling (DIPP); structural (HSET), and other genes (TULP1,
HSPRARD, DEF-6, EO6811, cyclophilin), as well as a number of RP genes and
pseudogenes (RPS10, RPS12-like, RPL12-like, RPL35-like). Furthermore, several
novel genes (a Br140-like, a G2S-like, a FBN2-like, a ZNF-like, and B1/KIAA0229)
have been identified, as well as cDNAs and cDNA contigs. The detailed map of the
gene content of this chromosomal segment provides a number of candidate genes,
which may be involved in several biological processes that have been associated
with this region, such as spermatogenesis, development, embryogenesis, and
neoplasia. The data provide useful tools for synteny studies between mice and
humans, for genome structure analysis, gene density comparisons, and studies of
nucleotide composition, of different isochores and Giemsa light and Giemsa dark
bands.
PMID- 10779487
TI - New target regions for human hypertension via comparative genomics.
AB - Models of human disease have long been used to understand the basic
pathophysiology of disease and to facilitate the discovery of new therapeutics.
However, as long as models have been used there have been debates about the
utility of these models and their ability to mimic clinical disease at the
phenotypic level. The application of genetic studies to both humans and model
systems allows for a new paradigm, whereby a novel comparative genomics strategy
combined with phenotypic correlates can be used to bridge between clinical
relevance and model utility. This study presents a comparative genomic map for
"candidate hypertension loci in humans" based on translating QTLs between rat and
human, predicting 26 chromosomal regions in the human genome that are very likely
to harbor hypertension genes. The predictive power appears robust, as several of
these regions have also been implicated in mouse, suggesting that these regions
represent primary targets for the development of SNPs for linkage disequilibrium
testing in humans and/or provide a means to select specific models for additional
functional studies and the development of new therapeutics.
PMID- 10779488
TI - Genome annotation assessment in Drosophila melanogaster.
AB - Computational methods for automated genome annotation are critical to our
community's ability to make full use of the large volume of genomic sequence
being generated and released. To explore the accuracy of these automated feature
prediction tools in the genomes of higher organisms, we evaluated their
performance on a large, well-characterized sequence contig from the Adh region of
Drosophila melanogaster. This experiment, known as the Genome Annotation
Assessment Project (GASP), was launched in May 1999. Twelve groups, applying
state-of-the-art tools, contributed predictions for features including gene
structure, protein homologies, promoter sites, and repeat elements. We evaluated
these predictions using two standards, one based on previously unreleased high
quality full-length cDNA sequences and a second based on the set of annotations
generated as part of an in-depth study of the region by a group of Drosophila
experts. Although these standard sets only approximate the unknown distribution
of features in this region, we believe that when taken in context the results of
an evaluation based on them are meaningful. The results were presented as a
tutorial at the conference on Intelligent Systems in Molecular Biology (ISMB-99)
in August 1999. Over 95% of the coding nucleotides in the region were correctly
identified by the majority of the gene finders, and the correct intron/exon
structures were predicted for >40% of the genes. Homology-based annotation
techniques recognized and associated functions with almost half of the genes in
the region; the remainder were only identified by the ab initio techniques. This
experiment also presents the first assessment of promoter prediction techniques
for a significant number of genes in a large contiguous region. We discovered
that the promoter predictors' high false-positive rates make their predictions
difficult to use. Integrating gene finding and cDNA/EST alignments with promoter
predictions decreases the number of false-positive classifications but discovers
less than one-third of the promoters in the region. We believe that by
establishing standards for evaluating genomic annotations and by assessing the
performance of existing automated genome annotation tools, this experiment
establishes a baseline that contributes to the value of ongoing large-scale
annotation projects and should guide further research in genome informatics.
PMID- 10779489
TI - MAGPIE/EGRET annotation of the 2.9-Mb Drosophila melanogaster Adh region.
AB - Our challenge in annotating the 2.91-Mb Adh region of the Drosophila melanogaster
genome was to identify genetic and genomic features automatically, completely,
and precisely within a 6-week period. To do so, we augmented the MAGPIE microbial
genome annotation system to handle eukaryotic genomic sequence data. The new
configuration required the integration of eukaryotic gene-finding tools and DNA
repeat tools into the automatic data collection module. It also required us to
define in MAGPIE new strategies to combine data about eukaryotic exon predictions
with functional data to refine the exon predictions. At the heart of the
resulting new eukaryotic genome annotation system is a reverse comparison of
public protein and complementary DNA sequences against the input genome to
identify missing exons and to refine exon boundaries. The software modules that
add eukaryotic genome annotation capability to MAGPIE are available as EGRET
(Eukaryotic Genome Rapid Evaluation Tool).
PMID- 10779490
TI - GeneID in Drosophila.
AB - GeneID is a program to predict genes in anonymous genomic sequences designed with
a hierarchical structure. In the first step, splice sites, and start and stop
codons are predicted and scored along the sequence using position weight matrices
(PWMs). In the second step, exons are built from the sites. Exons are scored as
the sum of the scores of the defining sites, plus the log-likelihood ratio of a
Markov model for coding DNA. In the last step, from the set of predicted exons,
the gene structure is assembled, maximizing the sum of the scores of the
assembled exons. In this paper we describe the obtention of PWMs for sites, and
the Markov model of coding DNA in Drosophila melanogaster. We also compare other
models of coding DNA with the Markov model. Finally, we present and discuss the
results obtained when GeneID is used to predict genes in the Adh region. These
results show that the accuracy of GeneID predictions compares currently with that
of other existing tools but that GeneID is likely to be more efficient in terms
of speed and memory usage.
PMID- 10779491
TI - Ab initio gene finding in Drosophila genomic DNA.
AB - Ab initio gene identification in the genomic sequence of Drosophila melanogaster
was obtained using (human gene predictor) and Fgenesh programs that have organism
specific parameters for human, Drosophila, plants, yeast, and nematode. We did
not use information about cDNA/EST in most predictions to model a real situation
for finding new genes because information about complete cDNA is often absent or
based on very small partial fragments. We investigated the accuracy of gene
prediction on different levels and designed several schemes to predict an
unambiguous set of genes (annotation CGG1), a set of reliable exons (annotation
CGG2), and the most complete set of exons (annotation CGG3). For 49 genes,
protein products of which have clear homologs in protein databases, predictions
were recomputed by Fgenesh+ program. The first annotation serves as the optimal
computational description of new sequence to be presented in a database. Reliable
exons from the second annotation serve as good candidates for selecting the PCR
primers for experimental work for gene structure verification. Our results shows
that we can identify approximately 90% of coding nucleotides with 20% false
positives. At the exon level we accurately predicted 65% of exons and 89%
including overlapping exons with 49% false positives. Optimizing accuracy of
prediction, we designed a gene identification scheme using Fgenesh, which
provided sensitivity (Sn) = 98% and specificity (Sp) = 86% at the base level, Sn
= 81% (97% including overlapping exons) and Sp = 58% at the exon level and Sn =
72% and Sp = 39% at the gene level (estimating sensitivity on std1 set and
specificity on std3 set). In general, these results showed that computational
gene prediction can be a reliable tool for annotating new genomic sequences,
giving accurate information on 90% of coding sequences with 14% false positives.
However, exact gene prediction (especially at the gene level) needs additional
improvement using gene prediction algorithms. The program was also tested for
predicting genes of human Chromosome 22 (the last variant of Fgenesh can analyze
the whole chromosome sequence). This analysis has demonstrated that the 88% of
manually annotated exons in Chromosome 22 were among the ab initio predicted
exons. The suite of gene identification programs is available through the WWW
server of Computational Genomics Group at http://genomic.sanger.ac.uk/gf. html.
PMID- 10779492
TI - Using database matches with for HMMGene for automated gene detection in
Drosophila.
AB - The application of the gene finder HMMGene to the Adh region of the Drosophila
melanogaster is described, and the prediction results are analyzed. HMMGene is
based on a probabilistic model called a hidden Markov model, and the
probabilistic framework facilitates the inclusion of database matches of varying
degrees of certainty. It is shown that database matches clearly improve the
performance of the gene finder. For instance, the sensitivity for coding exons
predicted with both ends correct grows from 62% to 70% on a high-quality test
set, when matches to proteins, cDNAs, repeats, and transposons are included. The
specificity drops more than the sensitivity increases when ESTs are used. This is
due to the high noise level in EST matches, and it is discussed in more detail
why this is and how it might be improved.
PMID- 10779493
TI - Genie--gene finding in Drosophila melanogaster.
AB - A hidden Markov model-based gene-finding system called Genie was applied to the
genomic Adh region in Drosophila melanogaster as a part of the Genome Annotation
Assessment Project (GASP). Predictions from three versions of the Genie gene
finding system were submitted, one based on statistical properties of coding
genes, a second included EST alignment information, and a third that integrated
protein sequence homology information. All three programs were trained on the
provided Drosophila training data. In addition, promoter assignments from an
integrated neural network were submitted. The gene assignments overlapped >90% of
the 222 annotated genes and 26 possibly novel genes were predicted, of which some
might be overpredictions. The system correctly identified the exon boundaries of
70% of the exons in cDNA-confirmed genes and 77% of the exons with the addition
of EST sequence alignments. The best of the three Genie submissions predicted 19
of the annotated 43 gene structures entirely correct (44%). In the promoter
category, only 30% of the transcription start sites could be detected, but by
integrating this program as a sensor into Genie the false-positive rate could be
dropped to 1/16,786 (0.006%). The results of the experiment on the long
contiguous genomic sequence revealed some problems concerning gene assembly in
Genie. The results were used to improve the system. We show that Genie is a
robust hidden Markov model system that allows for a generalized integration of
information from different sources such as signal sensors (splice sites, start
codon, etc.), content sensors (exons, introns, intergenic) and alignments of
mRNA, EST, and peptide sequences. The assessment showed that Genie could
effectively be used for the annotation of complete genomes from higher organisms.
PMID- 10779494
TI - Promoter prediction on a genomic scale--the Adh experience.
AB - We describe our statistical system for promoter recognition in genomic DNA with
which we took part in the Genome Annotation Assessment Project (GASP1). We
applied two versions of the system: the first uses a region-based approach toward
transcription start site identification, namely, interpolated Markov chains; the
second was a hybrid approach combining regions and signals within a stochastic
segment model. We compare the results of both versions with each other and
examine how well the application on a genomic scale compares with the results we
previously obtained on smaller data sets.
PMID- 10779495
TI - Drosophila genomic sequence annotation using the BLOCKS+ database.
AB - A simple and general homology-based method for gene finding was applied to the
2.9-Mb Drosophila melanogaster Adh region, the target sequence of the Genome
Annotation Assessment Project (GASP). Each strand of the entire sequence was used
as query of the BLOCKS+ database of conserved regions of proteins. This led to
functional assignments for more than one-third of the genes and two-thirds of the
transposons. Considering the enormous size of the query, the fact that only two
false-positive matches were reported emphasizes the high selectivity of protein
family-based methods for gene finding. We used the search results to improve
BLOCKS+ by identifying compositionally biased blocks. Our results confirm that
protein family databases can be used effectively in automated sequence annotation
efforts.
PMID- 10779496
TI - Using GeneWise in the Drosophila annotation experiment.
AB - The GeneWise method for combining gene prediction and homology searches was
applied to the 2.9-Mb region from Drosophila melanogaster. The results from the
Genome Annotation Assessment Project (GASP) showed that GeneWise provided
reasonably accurate gene predictions. Further investigation indicates that many
of the incorrect gene predictions from GeneWise were due to transposons with
valid protein-coding genes and the remaining cases are pseudogenes or possible
annotation oversights.
PMID- 10779497
TI - A microsphere-based assay for multiplexed single nucleotide polymorphism analysis
using single base chain extension.
AB - A rapid, high throughput readout for single-nucleotide polymorphism (SNP)
analysis was developed employing single base chain extension and cytometric
analysis of an array of fluorescent microspheres. An array of fluorescent
microspheres was coupled with uniquely identifying sequences, termed
complementary ZipCodes (cZipCodes), which allowed for multiplexing possibilities.
For a given assay, querying a polymorphic base involved extending an
oligonucleotide containing both a ZipCode and a SNP-specific sequence with a DNA
polymerase and a pair of fluoresceinated dideoxynucleotides. To capture the
reaction products for analysis, the ZipCode portion of the oligonucleotide was
hybridized with its cZipCodes on the microsphere. Flow cytometry was used for
microsphere decoding and SNP typing by detecting the fluorescein label captured
on the microspheres. In addition to multiplexing capability, the ZipCode system
allows multiple sets of SNPs to be analyzed by a limited set of cZipCode-attached
microspheres. A standard set of non-cross reactive ZipCodes was established
experimentally and the accuracy of the system was validated by comparison with
genotypes determined by other technologies. From a total of 58 SNPs, 55 SNPs were
successfully analyzed in the first pass using this assay format and all 181
genotypes across the 55 SNPs were correct. These data demonstrate that the
microsphere-based single base chain extension (SBCE) method is a sensitive and
reliable assay. It can be readily adapted to an automated, high-throughput
genotyping system. [Primer sequences used in this study are available as online
supplementary materials at www.genome.org.]
PMID- 10779498
TI - Genetic linkage mapping of zebrafish genes and ESTs.
AB - Genetic screens in zebrafish (Danio rerio) have isolated mutations in hundreds of
genes essential for vertebrate development, physiology, and behavior. We have
constructed a genetic linkage map that will facilitate the identification of
candidate genes for these mutations and allow comparisons among the genomes of
zebrafish and other vertebrates. On this map, we have localized 771 zebrafish
genes and expressed sequence tags (ESTs) by scoring single-stranded
conformational polymorphisms (SSCPs) in a meiotic mapping panel. Of these
sequences, 642 represent previously unmapped genes and ESTs. The mapping panel
was comprised of 42 homozygous diploid individuals produced by heat shock
treatment of haploid embryos at the one-cell stage (HS diploids). This "doubled
haploid" strategy combines the advantages of mapping in haploid and standard
diploid systems, because heat shock diploid individuals have only one allele at
each locus and can survive to adulthood, enabling a relatively large quantity of
genomic DNA to be prepared from each individual in the mapping panel. To
integrate this map with others, we also scored 593 previously mapped simple
sequence length polymorphisms (SSLPs) in the mapping panel. This map will
accelerate the molecular analysis of zebrafish mutations and facilitate
comparative analysis of vertebrate genomes.
PMID- 10779499
TI - Global properties of the metabolic map of Escherichia coli.
AB - The EcoCyc database characterizes the known network of Escherichia coli small
molecule metabolism. Here we present a computational analysis of the global
properties of that network, which consists of 744 reactions that are catalyzed by
607 enzymes. The reactions are organized into 131 pathways. Of the metabolic
enzymes, 100 are multifunctional, and 68 of the reactions are catalyzed by >1
enzyme. The network contains 791 chemical substrates. Other properties considered
by the analysis include the distribution of enzyme subunit organization, and the
distribution of modulators of enzyme activity and of enzyme cofactors. The
dimensions chosen for this analysis can be employed for comparative functional
analysis of complete genomes.
PMID- 10779500
TI - PipMaker--a web server for aligning two genomic DNA sequences.
AB - PipMaker (http://bio.cse.psu.edu) is a World-Wide Web site for comparing two long
DNA sequences to identify conserved segments and for producing informative, high
resolution displays of the resulting alignments. One display is a percent
identity plot (pip), which shows both the position in one sequence and the degree
of similarity for each aligning segment between the two sequences in a compact
and easily understandable form. Positions along the horizontal axis can be
labeled with features such as exons of genes and repetitive elements, and colors
can be used to clarify and enhance the display. The web site also provides a plot
of the locations of those segments in both species (similar to a dot plot).
PipMaker is appropriate for comparing genomic sequences from any two related
species, although the types of information that can be inferred (e.g., protein
coding regions and cis-regulatory elements) depend on the level of conservation
and the time and divergence rate since the separation of the species. Gene
regulatory elements are often detectable as similar, noncoding sequences in
species that diverged as much as 100-300 million years ago, such as humans and
mice, Caenorhabditis elegans and C. briggsae, or Escherichia coli and Salmonella
spp. PipMaker supports analysis of unfinished or "working draft" sequences by
permitting one of the two sequences to be in unoriented and unordered contigs.
PMID- 10779501
TI - Agkistin, a snake venom-derived glycoprotein Ib antagonist, disrupts von
Willebrand factor-endothelial cell interaction and inhibits angiogenesis.
AB - Glycoprotein (GP) Ib, an adhesion receptor expressed on both platelets and
endothelial cells, mediates the binding of von Willebrand factor (vWF). Platelet
GPIb plays an important role in platelet adhesion and activation, whereas the
interaction of vWF and endothelial GPIb is not fully understood. We report here
that agkistin, a snake venom protein, selectively blocks the interaction of vWF
with human endothelial GPIb and inhibits angiogenesis in vivo. Agkistin
specifically blocked human umbilical vein endothelial cell (HUVEC) adhesion to
immobilized vWF in a concentration-dependent manner. Fluorescein isothiocyanate
(FITC)-conjugated agkistin bound to HUVECs in a saturable manner. AP1, a
monoclonal antibody (mAb) raised against GPIb, specifically inhibited the binding
of FITC-conjugated agkistin to HUVECs in a dose-dependent manner, but other anti
integrin mAbs raised against alpha(v)beta(3), alpha(2)beta(1), and
alpha(5)beta(1) did not affect this binding reaction. However, neither agkistin
(2 microgram/ml) nor AP1 (40 microgram/ml) apparently reduced HUVEC viability.
Both agkistin and AP1 exhibited a profound anti-angiogenic effect in vivo when
assayed by using the 10-day-old embryo chick chorioallantoic membrane model.
These results suggest endothelial GPIb plays a role in spontaneous angiogenesis
in vivo, and the anti-angiogenic effect of agkistin may be because of disruption
of the interaction of endogenous vWF with endothelial GPIb.
PMID- 10779502
TI - Reaction of human myoglobin and H2O2. Involvement of a thiyl radical produced at
cysteine 110.
AB - The human myoglobin (Mb) sequence is similar to other mammalian Mb sequences,
except for a unique cysteine at position 110. Reaction of wild-type recombinant
human Mb, the C110A variant of human Mb, or horse heart Mb with H(2)O(2)
(protein/H(2)O(2) = 1:1.2 mol/mol) resulted in formation of tryptophan peroxyl
(Trp-OO( small middle dot)) and tyrosine phenoxyl radicals as detected by EPR
spectroscopy at 77 K. For wild-type human Mb, a second radical (g approximately
2. 036) was detected after decay of Trp-OO( small middle dot) that was not
observed for the C110A variant or horse heart Mb. When the spin trap 5,5-dimethyl
1-pyrroline N-oxide (DMPO) was included in the reaction mixture at protein/DMPO
ratios =1:10 mol/mol, a DMPO adduct exhibiting broad absorptions was detected.
Hyperfine couplings of this radical indicated a DMPO-thiyl radical. Incubation of
wild-type human Mb with thiol-blocking reagents prior to reaction with peroxide
inhibited DMPO adduct formation, whereas at protein/DMPO ratios >/=1:25 mol/mol,
DMPO-tyrosyl radical adducts were detected. Mass spectrometry of wild-type human
Mb following reaction with H(2)O(2) demonstrated the formation of a homodimer
(mass of 34,107 +/- 5 atomic mass units) sensitive to reducing conditions. The
human Mb C110A variant afforded no dimer under identical conditions. Together,
these data indicate that reaction of wild-type human Mb and H(2)O(2) differs from
the corresponding reaction of other myoglobin species by formation of thiyl
radicals that lead to a homodimer through intermolecular disulfide bond
formation.
PMID- 10779503
TI - Probing the active center gorge of acetylcholinesterase by fluorophores linked to
substituted cysteines.
AB - To examine the influence of individual side chains in governing rates of ligand
entry into the active center gorge of acetylcholinesterase and to characterize
the dynamics and immediate environment of these residues, we have conjugated
reactive groups with selected charge and fluorescence characteristics to
cysteines substituted by mutagenesis at specific positions on the enzyme.
Insertion of side chains larger than in the native tyrosine at position 124 near
the constriction point of the active site gorge confers steric hindrance to
affect maximum catalytic throughput (k(cat)/K(m)) and rates of diffusional entry
of trifluoroketones to the active center. Smaller groups appear not to present
steric constraints to entry; however, cationic side chains selectively and
markedly reduce cation ligand entry through electrostatic repulsion in the gorge.
The influence of side chain modification on ligand kinetics has been correlated
with spectroscopic characteristics of fluorescent side chains and their capacity
to influence the binding of a peptide, fasciculin, which inhibits catalysis
peripherally by sealing the mouth of the gorge. Acrylodan conjugated to cysteine
was substituted for tyrosine at position 124 within the gorge, for histidine 287
on the surface adjacent to the gorge and for alanine 262 on a mobile loop distal
to the gorge. The 124 position reveals the most hydrophobic environment and the
largest hypsochromic shift of the emission maximum with fasciculin binding. This
finding likely reflects a sandwiching of the acrylodan in the complex with the
tip of fasciculin loop II. An intermediate spectral shift is found for the 287
position, consistent with partial occlusion by loops II and III of fasciculin in
the complex. Spectroscopic properties of the acrylodan at the 262 position are
unaltered by fasciculin addition. Hence, combined spectroscopic and kinetic
analyses reveal distinguishing characteristics in various regions of
acetylcholinesterase that influence ligand association.
PMID- 10779504
TI - p300 and p300/cAMP-response element-binding protein-associated factor acetylate
the androgen receptor at sites governing hormone-dependent transactivation.
AB - The androgen receptor (AR) is a sequence-specific DNA-binding protein that plays
a key role in prostate cancer cellular proliferation by dihydrotestosterone and
the induction of secondary sexual characteristics. In this study we demonstrate
that the AR can be modified by acetylation in vitro and in vivo. p300 and
p300/cAMP-response element-binding protein acetylated the AR at a highly
conserved lysine-rich motif carboxyl-terminal to the zinc finger DNA-binding
domain. [(14)C]acetate-labeling experiments demonstrated that AR acetylation by
p300 in cultured cells requires the same residues identified in vitro. Point
mutation of the AR acetylation site (K632A/K633A) abrogated dihydrotestosterone
dependent transactivation of the AR in cultured cells. Mutation of the p300 CH3
region or the p300/cAMP-response element-binding protein histone acetylase domain
reduced ligand-dependent AR function. The identification of the AR as a direct
target of histone acetyltransferase co-activators has important implications for
targeting inhibitors of AR function.
PMID- 10779505
TI - Inhibition of papain by S-nitrosothiols. Formation of mixed disulfides.
AB - S-Nitrosylation of protein thiols is one of the cellular regulatory mechanisms
induced by NO. The cysteine protease papain has a critical thiol residue
(Cys(25)). It has been demonstrated that NO or NO donors such as sodium
nitroprusside and N-nitrosoaniline derivatives can reversibly inhibit this enzyme
by S-NO bond formation in its active site. In this study, a different regulated
mechanism of inactivation was reported using S-nitrosothiols as the NO donor.
Five S-nitroso compounds, S-nitroso-N-acetyl-dl-penicillamine, S
nitrosoglutathione, S-nitrosocaptopril, glucose-S-nitroso-N-acetyl-dl
penicillamine-2, and the S-nitroso tripeptide acetyl-Phe-Gly-S
nitrosopenicillamine, exhibited different inhibitory activities toward the enzyme
in a time- and concentration-dependent manner with second-order rate constants
(k(i)/K(I)) ranging from 8.9 to 17.2 m(-1) s(-1). The inhibition of papain by S
nitrosothiol was rapidly reversed by dithiothreitol, but not by ascorbate, which
could reverse the inhibition of papain by NOBF(4). Incubation of the enzyme with
a fluorescent S-nitroso probe (S-nitroso-5-dimethylaminonaphthalene-1-sulfonyl)
resulted in the appearance of fluorescence of the protein, indicating the
formation of a thiol adduct. Moreover, S-transnitrosylation in the incubation of
S-nitroso inactivators with papain was excluded. These results suggest that
inactivation of papain by S-nitrosothiols is due to a direct attack of the highly
reactive thiolate (Cys(25)) in the enzyme active site on the sulfur of S
nitrosothiols to form a mixed disulfide between the inactivator and papain.
PMID- 10779506
TI - The gene encoding the mitogen-responsive phosphoprotein Dab2 is differentially
regulated by GATA-6 and GATA-4 in the visceral endoderm.
AB - Gene targeting studies have demonstrated that the zinc finger transcription
factor GATA-6 lies upstream in a transcriptional cascade that controls
differentiation of the visceral endoderm. To understand the function of GATA-6 in
the visceral endoderm and to identify genes regulated by GATA-6 in this tissue,
subtractive hybridization was performed using template cDNAs derived from
differentiated wild-type embryonic stem (ES) cells and GATA-6(-/-) ES cells,
respectively. These analyses revealed that the gene encoding Dab2, a mitogen
responsive phosphoprotein, is differentially expressed in wild-type and GATA-6
deficient ES cells. Consistent with these findings, Dab2 is expressed in the
visceral endoderm of wild-type embryos but not in the visceral endoderm of GATA-6
deficient embryos. Cotransfection experiments demonstrate that the human Dab2
promoter can be transactivated by forced expression of GATA-6 in NIH-3T3 cells.
In contrast, forced expression of GATA-4 does not transactivate the human Dab2
promoter and Dab2 is expressed in the visceral endoderm of GATA-4 null embryos.
Surprisingly, the specificity of GATA-6-induced transactivation of the Dab2
promoter is not mediated through its zinc finger DNA-binding domain. Taken
together, these data demonstrate that the mitogen-responsive phosphoprotein Dab2
is a downstream target of GATA-6 in the visceral endoderm. Moreover, these data
demonstrate that molecular mechanisms have evolved that direct, and distinguish,
the functional specificity of GATA family members when they are developmentally
coexpressed.
PMID- 10779507
TI - Localization and genomic organization of a new hepatocellular organic anion
transporting polypeptide.
AB - Based on sequence homology to the human organic anion transporting polypeptide 2
(OATP2; SLC21A6), we cloned a new member of the SLC21A superfamily of solute
carriers, termed OATP8 (SLC21A8). The protein of 702 amino acids showed an amino
acid identity of 80% with human OATP2. Based on Northern blotting, the expression
of OATP8 was restricted to human liver. Cosmid clones containing the genes
encoding human OATP1 (SLC21A3), OATP2 (SLC21A6), and OATP8 (SLC21A8) served to
establish their genomic organization. All three genes contained 14 exons with 13
identical splice sites when transferred to the amino acid sequence. An antibody
raised against the carboxyl terminus localized OATP8 to the basolateral membrane
of human hepatocytes and the recombinant glycoprotein, expressed in MDCKII cells,
to the lateral membrane. Transport properties of OATP8 were studied in stably
transfected MDCKII and HEK293 cells. Organic anions transported by human OATP8
included sulfobromophthalein, with a K(m) of 3.3 microm, and 17beta-glucuronosyl
estradiol, with a K(m) of 5.4 microm. Several bile salts were not substrates.
Thus, human OATP8 is a new uptake transporter in the basolateral hepatocyte
membrane with an overlapping but distinct substrate specificity as compared with
OATP2, which is localized to the same membrane domain.
PMID- 10779508
TI - Estrogen receptor-related receptor alpha 1 interacts with coactivator and
constitutively activates the estrogen response elements of the human lactoferrin
gene.
AB - The human estrogen receptor-related receptor (ERRalpha1, NR3B1a) was shown to
bind a steroidogenic factor binding element (SFRE), TCAAGGTCATC, 26 base pairs
upstream from the estrogen response element (ERE) of the human lactoferrin gene
promoter. A mutation made at SFRE significantly reduced estrogen-dependent
transcription from the lactoferrin ERE in human endometrial cells. In this study,
we demonstrated that ERRalpha1 binds both SFRE and ERE elements and
constitutively transactivates the lactoferrin gene promoter. In DNase I
footprinting protection analysis, both SFRE and ERE regions were protected by
glutathione S-transferase-ERRalpha1 fusion protein. The receptor formed two
protein-DNA complexes with either SFRE or ERE in electrophoresis mobility shift
assay. Homodimerization of ERRalpha1 was confirmed with the mammalian two-hybrid
system. ERRalpha1 activates reporter constructs containing various types of
estrogen response elements in endometrial and non-endometrial cells in transient
transfection experiments. Overexpressing the coactivator, SRC1a or GRIP1, further
enhances ERRalpha1-induced transcriptional activity. We demonstrated that the AF2
domain of ERRalpha1 is essential for the transactivation function and that
deletion or mutation at this region abrogates the activation capability. Protein
protein interaction between the SRC1a and ERRalpha1 C terminus was confirmed with
a GST glutathione S-transferase "pull-down" assay. When comparing ERRalpha1 and
the estrogen receptor alpha (ERalpha) in many of the experiments, we found that
ERalpha can also bind SFRE of the lactoferrin gene and transactivate the promoter
activity in a ligand-dependent manner. The present study demonstrated that
ERRalpha1 binds similar DNA elements as ERalpha and confers its transactivation
function constitutively. Therefore, ERRalpha1 may actively modulate the estrogen
response of lactoferrin gene as well as other estrogen-responsive genes.
PMID- 10779509
TI - Coreceptor function of mutant human CD4 molecules without affinity to gp120 of
human immunodeficiency virus.
AB - Despite extensive mutational studies on the human CD4 molecule and its affinity
to human immunodeficiency virus (HIV) envelope glycoprotein gp120, coreceptor
functions of such mutant molecules have only been examined by indirect
measurement of their affinity to class II major histocompatibility complex (MHC)
molecules. In this report, coreceptor functions of mutant human CD4 molecules,
which have no or reduced affinity to an HIV envelope protein, gp120, were
assessed in a murine T cell receptor/class II MHC recognition system. The
substitution of human C" beta strand with the murine homologous segment resulted
in the loss of the coreceptor function as well as in the complete loss of gp120
binding capacity, corroborating the consensus that Phe-43 in C" beta strand plays
crucial roles in both situations. However, simultaneous replacement of the C'-C"
loop along with the C" beta strand by homologous murine segments rescued the
coreceptor function, whereas gp120 binding capacity remained negative. Further
analysis indicated that insertion of lysine between Gly-41 and Ser-42 can
partially compensate for the coreceptor function lost by the Phe-43 --> Val
mutation. Although the coreceptor function of these mutant CD4 molecules in a
human T cell recognition system is yet to be determined, these observations
necessitate a re-evaluation of the role played by Phe-43 in coreceptor function.
Examination of the sensitivities of the mutant CD4 molecules expressed on HeLa
cells to infection by a T cell-tropic HIV-1 strain indicated that only those
mutants that had completely lost gp120 binding capacity were resistant to the
infection. All mutants having whole C" substitution, irrespective of additional
substitutions or their coreceptor functions, were resistant to the infection.
PMID- 10779510
TI - Limits of protein folding inside GroE complexes.
AB - The GroE chaperones of Escherichia coli promote the folding of other proteins
under conditions where no spontaneous folding occurs. One requirement for this
reaction is the trapping of the nonnative protein inside the chaperone complex.
Encapsulation may be important to prevent unfavorable intermolecular interactions
during folding. We show here that, especially for oligomeric proteins, the timing
of encapsulation and release is of critical importance. If this cycle is
decelerated, misfolding is observed inside functional chaperone complexes.
PMID- 10779511
TI - Structural and functional studies with antibodies to the integrin beta 2 subunit.
A model for the I-like domain.
AB - To establish a structure and function map of the beta2 integrin subunit, we
mapped the epitopes of a panel of beta2 monoclonal antibodies including function
blocking, nonblocking, and activating antibodies using human/mouse beta2 subunit
chimeras. Activating antibodies recognize the C-terminal half of the cysteine
rich region, residues 522-612. Antibodies that do not affect ligand binding map
to residues 1-98 and residues 344-521. Monoclonal antibodies to epitopes within a
predicted I-like domain (residues 104-341) strongly inhibit LFA-1-dependent
adhesion. These function-blocking monoclonal antibodies were mapped to specific
residues with human --> mouse knock-out or mouse --> human knock-in mutations.
Combinatorial epitopes involving residues distant in the sequence provide support
for a specific alignment between the beta-subunit and I domains that was used to
construct a three-dimensional model. Antigenic residues 133, 332, and 339 are on
the first and last predicted alpha-helices of the I-like domain, which are
adjacent on its "front." Other antigenic residues in beta2 and in other integrin
beta subunits are present on the front. No antigenic residues are present on the
"back" of the domain, which is predicted to be in an interface with other
domains, such as the alpha subunit beta-propeller domain. Most mutations in the
beta2 subunit in leukocyte adhesion deficiency are predicted to be buried in the
beta2 subunit I-like domain. Two long insertions are present relative to alpha
subunit I-domains. One is tied down to the back of the I-like domain by a
disulfide bond. The other corresponds to the "specificity-determining loop"
defined in beta1 and beta3 integrins and contains the antigenic residue Glu(175)
in a disulfide-bonded loop located near the "top" of the domain.
PMID- 10779512
TI - Identification and purification of vitamin K-dependent proteins and peptides with
monoclonal antibodies specific for gamma -carboxyglutamyl (Gla) residues.
AB - Novel monoclonal antibodies that specifically recognize gamma-carboxyglutamyl
(Gla) residues in proteins and peptides have been produced. As demonstrated by
Western blot and time-resolved immunofluorescence assays the antibodies are pan
specific for most or all of the Gla-containing proteins tested (factors VII, IX,
and X, prothrombin, protein C, protein S, growth arrest-specific protein 6, bone
Gla protein, conantokin G from a cone snail, and factor Xa-like proteins from
snake venom). Only the Gla-containing light chain of the two-chain proteins was
bound. Decarboxylation destroyed the epitope(s) on prothrombin fragment 1, and
Ca(2+) strongly inhibited binding to prothrombin. In Western blot,
immunofluorescence, and surface plasmon resonance assays the antibodies bound
peptides conjugated to bovine serum albumin that contained either a single Gla or
a tandem pair of Gla residues. Binding was maintained when the sequence
surrounding the Gla residue(s) was altered. Replacement of Gla with glutamic acid
resulted in a complete loss of the epitope. The utility of the antibodies was
demonstrated in immunochemical methods for detecting Gla-containing proteins and
in the immunopurification of a factor Xa-like protein from tiger snake venom. The
amino acid sequences of the Gla domain and portions of the heavy chain of the
snake protein were determined.
PMID- 10779513
TI - A carboxylate triad is essential for the polymerase activity of Escherichia coli
DNA polymerase I (Klenow fragment). Presence of two functional triads at the
catalytic center.
AB - The catalytic roles of two essential active-site aspartates at positions 705 and
882 of Escherichia coli DNA polymerase I have been well established (Steitz, T.
A. (1998) Nature 391, 231-232). We now demonstrate that the participation of at
least one additional carboxylate, a glutamate at position 710 or 883, is
obligatory for catalysis. This conclusion has been drawn from our investigation
of the properties of single (E710D, E710A, E883D, and E883A) and double
(E710D/E883D and E710A/E883A) substitutions of residues Glu(710) and Glu(883).
While single substitutions of either of the glutamates resulted in some reduction
in polymerase activity, the mutant enzyme with simultaneous substitution of both
glutamates with alanine exhibited a nearly complete loss of activity.
Interestingly, substitution with two aspartates in place of the glutamates
resulted in an enzyme species that catalyzed DNA synthesis in a strictly
distributive mode. Pyrophosphorolytic activity of the mutant enzymes reflected
their polymerase activity profiles, with markedly reduced pyrophosphorolysis by
the double mutant enzymes. Moreover, an evaluation of Mg(2+) and salt optima for
all mutant enzymes of Glu(710) and Glu(883) revealed significant deviations from
that for the wild type, implying a possible role of these glutamates in metal
coordination as well as in maintaining the structural integrity of the active
site.
PMID- 10779514
TI - Suppressor mutations in the chloroplast-encoded large subunit improve the thermal
stability of wild-type ribulose-1,5-bisphosphate carboxylase/oxygenase.
AB - A temperature-conditional, photosynthesis-deficient mutant of the green alga
Chlamydomonas reinhardtii, previously recovered by genetic screening, results
from a leucine 290 to phenylalanine (L290F) substitution in the chloroplast
encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase
(Rubisco, EC ). Rubisco purified from mutant cells grown at 25 degrees C has a
reduction in CO(2)/O(2) specificity and is inactivated at lower temperatures than
those that inactivate the wild-type enzyme. Second-site alanine 222 to threonine
(A222T) or valine 262 to leucine (V262L) substitutions were previously isolated
via genetic selection for photosynthetic ability at the 35 degrees C restrictive
temperature. These intragenic suppressors improve the CO(2)/O(2) specificity and
thermal stability of L290F Rubisco in vivo and in vitro. In the present study,
directed mutagenesis and chloroplast transformation were used to create the A222T
and V262L substitutions in an otherwise wild-type enzyme. Although neither
substitution improves the CO(2)/O(2) specificity above the wild-type value, both
improve the thermal stability of wild-type Rubisco in vitro. Based on the x-ray
crystal structure of spinach Rubisco, large subunit residues 222, 262, and 290
are far from the active site. They surround a loop of residues in the nuclear
encoded small subunit. Interactions at this subunit interface may substantially
contribute to the thermal stability of the Rubisco holoenzyme.
PMID- 10779515
TI - Structure of a C-type carbohydrate recognition domain from the macrophage mannose
receptor.
AB - The mannose receptor of macrophages and liver endothelium mediates clearance of
pathogenic organisms and potentially harmful glycoconjugates. The extracellular
portion of the receptor includes eight C-type carbohydrate recognition domains
(CRDs), of which one, CRD-4, shows detectable binding to monosaccharide ligands.
We have determined the crystal structure of CRD-4. Although the basic C-type
lectin fold is preserved, a loop extends away from the core of the domain to form
a domain-swapped dimer in the crystal. Of the two Ca(2+) sites, only the
principal site known to mediate carbohydrate binding in other C-type lectins is
occupied. This site is altered in a way that makes sugar binding impossible in
the mode observed in other C-type lectins. The structure is likely to represent
an endosomal form of the domain formed when Ca(2+) is lost from the auxiliary
calcium site. The structure suggests a mechanism for endosomal ligand release in
which the auxiliary calcium site serves as a pH sensor. Acid pH-induced removal
of this Ca(2+) results in conformational rearrangements of the receptor,
rendering it unable to bind carbohydrate ligands.
PMID- 10779516
TI - Functional delineation of three groups of the ATP-dependent family of chromatin
remodeling enzymes.
AB - ATP-dependent chromatin remodeling enzymes antagonize the inhibitory effects of
chromatin. We compare six different remodeling complexes: ySWI/SNF, yRSC,
hSWI/SNF, xMi-2, dCHRAC, and dNURF. We find that each complex uses similar
amounts of ATP to remodel nucleosomal arrays at nearly identical rates. We also
perform assays with arrays reconstituted with hyperacetylated or trypsinized
histones and isolated histone (H3/H4)(2) tetramers. The results define three
groups of the ATP-dependent family of remodeling enzymes. In addition we
investigate the ability of an acidic activator to recruit remodeling complexes to
nucleosomal arrays. We propose that ATP-dependent chromatin remodeling enzymes
share a common reaction mechanism and that a key distinction between complexes is
in their mode of regulation or recruitment.
PMID- 10779517
TI - Ca2+-sensitive inactivation and facilitation of L-type Ca2+ channels both depend
on specific amino acid residues in a consensus calmodulin-binding motif in
the(alpha)1C subunit.
AB - L-type Ca(2+) channels are unusual in displaying two opposing forms of
autoregulatory feedback, Ca(2+)-dependent inactivation and facilitation. Previous
studies suggest that both involve direct interactions between calmodulin (CaM)
and a consensus CaM-binding sequence (IQ motif) in the C terminus of the
channel's alpha(1C) subunit. Here we report the functional effects of an
extensive series of modifications of the IQ motif aimed at dissecting the
structural determinants of the different forms of modulation. Although the
combined substitution by alanine at five key positions (Ile(1624), Gln(1625),
Phe(1628), Arg(1629), and Lys(1630)) abolished all Ca(2+) dependence,
corresponding single alanine replacements behaved similarly to the wild-type
channel (77wt) in four of five cases. The mutant I1624A stood out in displaying
little or no Ca(2+)-dependent inactivation, but clear Ca(2+)- and frequency
dependent facilitation. An even more pronounced tilt in favor of facilitation was
seen with the double mutant I1624A/Q1625A: overt facilitation was observed even
during a single depolarizing pulse, as confirmed by two-pulse experiments.
Replacement of Ile(1624) by 13 other amino acids produced graded and distinct
patterns of change in the two forms of modulation. The extent of Ca(2+)-dependent
facilitation was monotonically correlated with the affinity of CaM for the mutant
IQ motif, determined in peptide binding experiments in vitro. Ca(2+)-dependent
inactivation also depended on strong CaM binding to the IQ motif, but showed an
additional requirement for a bulky, hydrophobic side chain at position 1624.
Abolition of Ca(2+)-dependent modulation by IQ motif modifications mimicked and
occluded the effects of overexpressing a dominant-negative CaM mutant.
PMID- 10779518
TI - Developmental regulation of collagenase-3 mRNA in normal, differentiating
osteoblasts through the activator protein-1 and the runt domain binding sites.
AB - Collagenase-3 mRNA is initially detectable when osteoblasts cease proliferation,
increasing during differentiation and mineralization. We showed that this
developmental expression is due to an increase in collagenase-3 gene
transcription. Mutation of either the activator protein-1 or the runt domain
binding site decreased collagenase-3 promoter activity, demonstrating that these
sites are responsible for collagenase-3 gene transcription. The activator protein
1 and runt domain binding sites bind members of the activator protein-1 and core
binding factor family of transcription factors, respectively. We identified core
binding factor a1 binding to the runt domain binding site and JunD in addition to
a Fos-related antigen binding to the activator protein-1 site. Overexpression of
both c-Fos and c-Jun in osteoblasts or core-binding factor a1 increased
collagenase-3 promoter activity. Furthermore, overexpression of c-Fos, c-Jun, and
core-binding factor a1 synergistically increased collagenase-3 promoter activity.
Mutation of either the activator protein-1 or the runt domain binding site
resulted in the inability of c-Fos and c-Jun or core-binding factor a1 to
increase collagenase-3 promoter activity, suggesting that there is cooperative
interaction between the sites and the proteins. Overexpression of Fra-2 and JunD
repressed core-binding factor a1-induced collagenase-3 promoter activity. Our
results suggest that members of the activator protein-1 and core-binding factor
families, binding to the activator protein-1 and runt domain binding sites are
responsible for the developmental regulation of collagenase-3 gene expression in
osteoblasts.
PMID- 10779519
TI - Bicarbonate binding activity of the CmpA protein of the cyanobacterium
Synechococcus sp. strain PCC 7942 involved in active transport of bicarbonate.
AB - The cmpABCD operon of the cyanobacterium Synechococcus sp. strain PCC 7942
encodes an ATP-binding cassette transporter involved in HCO(3)(-) uptake. The
three genes, cmpBCD, encode membrane components of an ATP-binding cassette
transporter, whereas cmpA encodes a 42-kDa cytoplasmic membrane protein, which is
46.5% identical to the membrane-anchored substrate-binding protein of the
nitrate/nitrite transporter. Equilibrium dialysis analysis using H(14)CO(3)(-)
showed that a truncated CmpA protein lacking the N-terminal 31 amino acids,
expressed in Escherichia coli cells as a histidine-tagged soluble protein,
specifically binds inorganic carbon (CO(2) or HCO(3)(-)). The addition of the
recombinant CmpA protein to a buffer caused a decrease in the concentration of
dissolved CO(2) because of the binding of inorganic carbon to the protein. The
decrease in CO(2) concentration was accelerated by the addition of carbonic
anhydrase, indicating that HCO(3)(-), but not CO(2), binds to the protein. Mass
spectrometric measurements of the amounts of unbound and bound HCO(3)(-) in CmpA
solutions containing low concentrations of inorganic carbon revealed that CmpA
binds HCO(3)(-) with high affinity (K(d) = 5 microm). A similar dissociation
constant was obtained by analysis of the competitive inhibition of the CmpA
protein on the carboxylation of phosphoenolpyruvate by phosphoenolpyruvate
carboxylase at limiting concentrations of HCO(3)(-). These findings showed that
the cmpA gene encodes the substrate-binding protein of the HCO(3)(-) transporter.
PMID- 10779520
TI - Interferon-alpha induces nmi-IFP35 heterodimeric complex formation that is
affected by the phosphorylation of IFP35.
AB - Nmi and IFP35 are interferon (IFN)-induced proteins. In cells treated with IFN
gamma, Nmi enhances the association of transcription co-activator CBP/p300 with
signal transducer and activator of transcription proteins, and IFP35 forms a high
molecular weight cytosolic complex of unknown constituents. Here we show that Nmi
and IFP35 co-immunoprecipitate with an anti-keratin 19 antibody, which is due to
cross-reaction of the antibody with Nmi, and suggests an Nmi-IFP35 physical
association. In support of this, Nmi and IFP35 co-immunoprecipitate using anti
Nmi and anti-IFP35 antibodies, manifest enhanced colocalization as determined by
immunofluorescence staining of IFN-treated cells, and form heterodimers as
determined by chemical cross-linking. Nmi and IFP35 are primarily cytosolic
proteins, and their interaction is increased after IFN-alpha treatment of cells
as early as 1 h after exposure. Sucrose gradient sedimentation and size
fractionation showed a shift of Nmi-IFP35 heterodimers toward a heavier fraction
(100-200 kDa) in IFN-alpha-treated cells. This dynamic complex formation is
reversed by pretreatment with okadaic acid. Two-dimensional gel analysis
indicates that the IFN-induced complex formation correlates with IFP35
dephosphorylation. Our data demonstrate Nmi-IFP35 cytosolic localization and
heterodimerization, and an IFN-alpha-regulated molecular event in which Nmi and
IFP35 participate, reversibly and by a dephosphorylation dependent fashion, in a
100-200-kDa molecular complex formation.
PMID- 10779521
TI - Vascular endothelial junction-associated molecule, a novel member of the
immunoglobulin superfamily, is localized to intercellular boundaries of
endothelial cells.
AB - During the process of lymphocyte homing to secondary lymphoid organs, such as
lymph nodes and tonsils, lymphocytes interact with and cross a specialized
microvasculature, known as high endothelial venules. There is a great deal of
information available about the first steps in the homing cascade, but molecular
understanding of lymphocyte transmigration through the intercellular junctions of
high endothelial venules is lacking. In analyzing expressed sequence tags from a
cDNA library prepared from human tonsillar high endothelial cells, we have
identified a cDNA encoding a novel member of the immunoglobulin superfamily. The
protein, which we have termed VE-JAM ("vascular endothelial junction-associated
molecule"), contains two extracellular immunoglobulin-like domains, a
transmembrane domain, and a relatively short cytoplasmic tail. VE-JAM is
prominently expressed on high endothelial venules but is also present on the
endothelia of other vessels. Strikingly, it is highly localized to the
intercellular boundaries of high endothelial cells. VE-JAM is most homologous to
a recently identified molecule known as Junctional Adhesion Molecule, which is
concentrated at the intercellular boundaries of both epithelial and endothelial
cells. Because the Junctional Adhesion Molecule has been strongly implicated in
the processes of neutrophil and monocyte transendothelial migration, an analogous
function of VE-JAM during lymphocyte homing is plausible.
PMID- 10779522
TI - A distinct sequence (ATAAA)n separates methylated and unmethylated domains at the
5'-end of the GSTP1 CpG island.
AB - What defines the boundaries between methylated and unmethylated domains in the
genome is unclear. In this study we used bisulfite genomic sequencing to map the
boundaries of methylation that flank the 5'- and 3'-ends of the CpG island
spanning the promoter region of the glutathione S-transferase (GSTP1) gene. We
show that GSTP1 is expressed in a wide range of tissues including brain, lung,
skeletal muscle, spleen, pancreas, bone marrow, prostate, heart, and blood and
that this expression is associated with the CpG island being unmethylated. In
these normal tissues a marked boundary was found to separate the methylated and
unmethylated regions of the gene at the 5'-flank of the CpG island, and this
boundary correlated with an (ATAAA)(19-24) repeated sequence. In contrast, the 3'
end of the CpG island was not marked by a sharp transition in methylation but by
a gradual change in methylation density over about 500 base pairs. In normal
tissue the sequences on either side of the 5'-boundary appear to lie in separate
domains in which CpG methylation is independently controlled. These separate
methylation domains are lost in all prostate cancer where GSTP1 expression is
silenced and methylation extends throughout the island and spans across both the
5'- and 3'-boundary regions.
PMID- 10779523
TI - Macrophage-enriched myristoylated alanine-rich C kinase substrate and its
phosphorylation is required for the phorbol ester-stimulated diffusion of beta 2
integrin molecules.
AB - An early event of beta(2) integrin activation is the increased diffusion rate of
this molecule on the cell surface, thereby providing integrin molecules with a
better chance to meet the ligands. The activation of protein kinase C (PKC)
stimulates integrin diffusion by releasing the cytoskeletal constraint on
integrin molecules. We report here that macrophage-enriched myristoylated alanine
rich C kinase substrate (MacMARCKS), a membrane-associated PKC substrate involved
in integrin activation, is required for this PKC-stimulated diffusion of integrin
molecules. Using the single-particle tracking technique, we observed that the
activation of PKC stimulated an 11-fold increase in the diffusion rate of beta(2)
integrins in wild type J774 macrophage cells but not in those expressing mutant
MacMARCKS. Further evidence is provided from a MacMARCKS-deficient cell line in
which phorbol esters failed to stimulate the diffusion of integrin. Transfection
of wild type MacMARCKS into these cells restored the rapid diffusion rate of the
beta(2) integrins. The phosphorylation of MacMARCKS is important because
transfection of a nonphosphorylatable MacMARCKS mutant or the addition of
staurosporine eliminates the rapid diffusion rate of integrin. Furthermore,
adding cytochalasin D bypasses the MacMARCKS deficiency and stimulates beta(2)
integrin diffusion, suggesting that MacMARCKS's involvement in integrin
activation is prior or at the site of cytoskeleton. Therefore, we conclude that
MacMARCKS is required for releasing the cytoskeletal constraint on integrin
molecules during PKC-mediated integrin activation.
PMID- 10779524
TI - Identification of a novel, dendritic cell-associated molecule, dectin-1, by
subtractive cDNA cloning.
AB - Dendritic cells (DC) are special subsets of antigen presenting cells
characterized by their potent capacity to activate immunologically naive T cells.
By subtracting the mRNAs expressed by the mouse epidermus-derived DC line XS52
with the mRNAs expressed by the J774 macrophage line, we identified five novel
genes that were expressed selectively by this DC line. One of these genes encoded
a type II membrane-integrated polypeptide of 244 amino acids containing a
putative carbohydrate recognition domain motif at the COOH-terminal end. This
molecule, termed "dectin-1," was expressed abundantly at both mRNA and protein
levels by the XS52 DC line, but not by non-DC lines (including the J774
macrophage line). Dectin-1 mRNA was detected predominantly in spleen and thymus
(by Northern blotting) and in skin-resident DC, i.e. Langerhans cells (by reverse
transcription-polymerase chain reaction). Affinity-purified antibody against
dectin-1 identified a 43-kDa glycoprotein in membrane fractions isolated from the
XS52 DC line and from the dectin-1 cDNA-transfected COS-1 cells. His-tagged
recombinant proteins containing the extracellular domains of dectin-1 showed
marked and specific binding to the surface of T cells and promoted their
proliferation in the presence of anti-CD3 monoclonal antibody at suboptimal
concentrations. These in vitro results suggest that dectin-1 on DC may bind to as
yet undefined ligand(s) on T cells, thereby delivering T cell co-stimulatory
signals. Not only do these results document the efficacy of subtractive cDNA
cloning for the identification of unique genes expressed by DC, they also provide
a framework for studying the physiological function of dectin-1.
PMID- 10779525
TI - Stimulation of NFkappa B activity by multiple signaling pathways requires PAK1.
AB - The p21-activated kinase (PAK1) is a serine-threonine protein kinase that is
activated by binding to the Rho family small G proteins Rac and Cdc42hs. Both Rac
and Cdc42hs have been shown to regulate the activity of the transcription factor
NFkappaB. Here we show that expression of active Ras, Raf-1, or Rac1 in
fibroblasts stimulates NFkappaB in a PAK1-dependent manner and that expression of
active PAK1 can stimulate NFkappaB on its own. Similarly, in macrophages
activation of NFkappaB as well as transcription from the tumor necrosis factor
alpha promoter depends on PAK1. In these cells lipopolysaccharide is a potent
activator of PAK1 kinase activity. We also demonstrate that expression of active
PAK1 stimulates the nuclear translocation of the p65 subunit of NFkappaB but does
not activate the inhibitor of kappaB kinases alpha or beta. These data
demonstrate that PAK1 is a crucial signaling molecule involved in NFkappaB
activation by multiple stimuli.
PMID- 10779526
TI - Ion channel clustering by membrane-associated guanylate kinases. Differential
regulation by N-terminal lipid and metal binding motifs.
AB - The postsynaptic density protein PSD-95 and related membrane-associated guanylate
kinase (MAGUK) proteins assemble signal transduction complexes at sites of cell
cell contact including synapses. Whereas PSD-95 and PSD-93 occur only at
postsynaptic sites in hippocampal neurons, SAP-102 also occurs in axons. In
heterologous cells, PSD-95 and PSD-93 mediate cell surface ion channel
clustering, but SAP-102 and SAP-97 do not. This selective ion channel clustering
activity by MAGUKs is explained by differential palmitoylation, as PSD-93 and PSD
95 are palmitoylated though SAP-97, and SAP-102 are not. Rather than being
palmitoylated, we find that N-terminal cysteines from SAP-102 tightly bind to
zinc. And, appending the N terminus of SAP-102 to PSD-95 results in localization
of the chimera to both axons and dendrites. These data suggest that lipid
modifications and heavy metal associations with the N termini of MAGUKs mediate
differential functions and subcellular localizations of these synaptic scaffolds.
PMID- 10779527
TI - Structure-function analysis of protease-activated receptor 4 tethered ligand
peptides. Determinants of specificity and utility in assays of receptor function.
AB - Thrombin activates protease-activated receptors (PARs) by specific cleavage of
their amino-terminal exodomains to unmask a tethered ligand that binds
intramolecularly to the body of the receptor to effect transmembrane signaling.
Peptides that mimic such ligands are valuable as agonists for probing PAR
function, but the tethered ligand peptide for PAR4, GYPGKF, lacks potency and is
of limited utility. In a structure-activity analysis of PAR4 peptides, AYPGKF was
approximately 10-fold more potent than GYPGKF and, unlike GYPGKF, elicited PAR4
mediated responses comparable in magnitude to those elicited by thrombin. AYPGKF
was relatively specific for PAR4 in part due to the tyrosine at position 2;
substitution of phenylalanine or p-fluorophenylalanine at this position produced
peptides that activated both PAR1 and PAR4. Because human platelets express both
PAR1 and PAR4, it might be desirable to inhibit both receptors. Identifying a
single agonist for both receptors raises the possibility that a single antagonist
for both receptors might be developed. The AYPGKF peptide is a useful new tool
for probing PAR4 function. For example, AYPGKF activated and desensitized PAR4 in
platelets and, like thrombin, triggered phosphoinositide hydrolysis but not
inhibition of adenylyl cyclase in PAR4-expressing cells. The latter shows that,
unlike PAR1, PAR4 couples to G(q) and not G(i).
PMID- 10779528
TI - Paralogy and orthology of tyrosine kinases that can extend the life span of
Caenorhabditis elegans.
AB - Modification of any one of three transmembrane protein tyrosine kinase (PTK)
genes, old-1, old-2 (formerly tkr-1 and tkr-2, respectively), and daf-2 can
extend the mean and maximum life span of the nematode Caenorhabditis elegans. To
identify paralogs and orthologs, we delineated relationships between these three
PTKs and all known transmembrane PTKs and all known mammalian nontransmembrane
PTKs using molecular phylogenetics. The tree includes a number of invertebrate
receptor PTKs and a novel mammalian receptor PTK (inferred from the expressed
sequence tag database) that have not previously been analyzed. old-1 and old-2
were found to be members of a surprisingly large C. elegans PTK family having 16
members. Interestingly, only four members of this transmembrane family appeared
to have receptor domains (immunoglobulin-like in each case). The C-terminal
domain of this family was found to have a unique sequence motif that could be
important for downstream signaling. Among mammalian PTKs, the old-1/old-2 family
appeared to be most closely related to the Pdgfr, Fgfr, Ret, and Tie/Tek
families. However, these families appeared to have split too early from the old
1/old-2 family to be orthologs, suggesting that a mammalian ortholog could yet be
discovered. An extensive search of the expressed-sequence tag database suggested
no additional candidate orthologs. In contrast to old-1 and old-2, daf-2 had no
C. elegans paralogs. Although daf-2 was most closely related to the mammalian
insulin receptor family, a hydra insulin receptor-like sequence suggested that
daf-2 might not be an ortholog of the insulin receptor family. Among PTKs, the
old-1/old-2 family and daf-2 were not particularly closely related, raising the
possibility that other PTK families might extend life span. On a more general
note, our survey of the expressed-sequence tag database suggested that few, if
any, additional mammalian PTK families are likely to be discovered. The one novel
family that was discovered could represent a novel oncogene family, given the
prevalence of oncogenes among PTKs. Finally, the PTK tree was consistent with
nematodes and fruit flies being as divergent as nematodes and mammals, suggesting
that life extension mechanisms shared by nematodes and fruit flies would be
reasonable candidates for extending mammalian life spans.
PMID- 10779529
TI - Molecular evolution of the wingless gene and its implications for the
phylogenetic placement of the butterfly family Riodinidae (Lepidoptera:
papilionoidea).
AB - The sequence evolution of the nuclear gene wingless was investigated among 34
representatives of three lepidopteran families (Riodinidae, Lycaenidae, and
Nymphalidae) and four outgroups, and its utility for inferring phylogenetic
relationships among these taxa was assessed. Parsimony analysis yielded a well
resolved topology supporting the monophyly of the Riodinidae and Lycaenidae,
respectively, and indicating that these two groups are sister lineages, with
strong nodal support based on bootstrap and decay indices. Although wingless
provides robust support for relationships within and between the riodinids and
the lycaenids, it is less informative about nymphalid relationships. Wingless
does not consistently recover nymphalid monophyly or traditional subfamilial
relationships within the nymphalids, and nodal support for all but the most
recent branches in this family is low. Much of the phylogenetic information in
this data set is derived from first- and second-position substitutions. However,
third positions, despite showing uncorrected pairwise divergences up to 78%, also
contain consistent signal at deep nodes within the family Riodinidae and at the
node defining the sister relationship between the riodinids and lycaenids.
Several hypotheses about how third-position signal has been retained in deep
nodes are discussed. These include among-site rate variation, identified as a
significant factor by maximum likelihood analyses, and nucleotide bias, a
prominent feature of third positions in this data set. Understanding the
mechanisms which underlie third-position signal is a first step in applying
appropriate models to accommodate the specific evolutionary processes involved in
each lineage.
PMID- 10779530
TI - Molecular evolution of two paralogous tandemly repeated heterochromatic gene
clusters linked to the X and Y chromosomes of Drosophila melanogaster.
AB - Here we report the peculiarities of molecular evolution and divergence of
paralogous heterochromatic clusters of the testis- expressed X-linked Stellate
and Y-linked Su(Ste) tandem repeats. It was suggested that Stellate and Su(Ste)
clusters affecting male fertility are the amplified derivatives of the unique
euchromatic gene betaCK2tes encoding the putative testis-specific beta-subunit of
protein kinase CK2. The putative Su(Ste)-like evolutionary intermediate was
detected on the Y chromosome as an orphon outside of the Su(Ste) cluster. The
orphon shows extensive homology to the Su(Ste) repeat, but contains several
Stellate-like diagnostic nucleotide substitutions, as well as a 10-bp insertion
and a 3' splice site of the first intron typical of the Stellate unit. The orphon
looks like a pseudogene carrying a drastically damaged Su(Ste) open reading frame
(ORF). The putative Su(Ste) ORF, as compared with the Stellate one, carries
numerous synonymous substitutions leading to the major codon preference. We
conclude that Su(Ste) ORFs evolved on the Y chromosome under the pressure of
translational selection. Direct sequencing shows that the efficiency of concerted
evolution between adjacent repeats is 5-10 times as high in the Stellate
heterochromatic cluster on the X chromosome as that in the Y-linked Su(Ste)
cluster, judging by the frequencies of nucleotide substitutions and single
nucleotide deletions.
PMID- 10779531
TI - Contrasting patterns of molecular evolution of the genes on the new and old sex
chromosomes of Drosophila miranda.
AB - In organisms with chromosomal sex determination, sex is determined by a set of
dimorphic sex chromosomes that are thought to have evolved from a set of
originally homologous chromosomes. The chromosome inherited only through the
heterogametic sex (the Y chromosome in the case of male heterogamety) often
exhibits loss of genetic activity for most of the genes carried on its homolog
and is hence referred to as degenerate. The process by which the proto-Y
chromosome loses its genetic activity has long been the subject of much
speculation. We present a DNA sequence variation analysis of marker genes on the
evolving sex chromosomes (neo-sex chromosomes) of Drosophila miranda. Due to its
relatively recent origin, the neo-Y chromosome of this species is presumed to be
still experiencing the forces responsible for the loss of its genetic activity.
Indeed, several previous studies have confirmed the presence of some active loci
on this chromosome. The genes on the neo-Y chromosome surveyed in the current
study show generally lower levels of variation compared with their counterparts
on the neo-X chromosome or an X-linked gene. This is in accord with a reduced
effective population size of the neo-Y chromosome. Interestingly, the rate of
replacement nucleotide substitutions for the neo-Y linked genes is significantly
higher than that for the neo-X linked genes. This is not expected under a model
where the faster evolution of the X chromosome is postulated to be the main force
driving the degeneration of the Y chromosome.
PMID- 10779532
TI - Phylogenetic analyses indicate that the 19'Hexanoyloxy-fucoxanthin-containing
dinoflagellates have tertiary plastids of haptophyte origin.
AB - The three anomalously pigmented dinoflagellates Gymnodinium galatheanum,
Gyrodinium aureolum, and Gymnodinium breve have plastids possessing 19'
hexanoyloxy-fucoxanthin as the major carotenoid rather than peridinin, which is
characteristic of the majority of the dinoflagellates. Analyses of SSU rDNA from
the plastid and the nuclear genome of these dinoflagellate species indicate that
they have acquired their plastids via endosymbiosis of a haptophyte. The
dinoflagellate plastid sequences appear to have undergone rapid sequence
evolution, and there is considerable divergence between the three species.
However, distance, parsimony, and maximum-likelihood phylogenetic analyses of
plastid SSU rRNA gene sequences place the three species within the haptophyte
clade. Pavlova gyrans is the most basal branching haptophyte and is the outgroup
to a clade comprising the dinoflagellate sequences and those of other
haptophytes. The haptophytes themselves are thought to have plastids of a
secondary origin; hence, these dinoflagellates appear to have tertiary plastids.
Both molecular and morphological data divide the plastids into two groups, where
G. aureolum and G. breve have similar plastid morphology and G. galatheanum has
plastids with distinctive features.
PMID- 10779533
TI - Evidence that a family of miniature inverted-repeat transposable elements (MITEs)
from the Arabidopsis thaliana genome has arisen from a pogo-like DNA transposon.
AB - Sequence similarities exist between terminal inverted repeats (TIRs) of some
miniature inverted-repeat transposable element (MITE) families isolated from a
wide range of organisms, including plants, insects, and humans, and TIRs of DNA
transposons from the pogo family. We present here evidence that one of these MITE
families, previously described for Arabidopsis thaliana, is derived from a larger
element encoding a putative transposase. We have named this novel class II
transposon Lemi1. We show that its putative product is related to transposases of
the Tc1/mariner superfamily, being closer to the pogo family. A similar truncated
element was found in a tomato DNA sequence, indicating an ancient origin and/or
horizontal transfer for this family of elements. These results are reminiscent of
those recently reported for the human genome, where other members of the pogo
family, named Tiggers, are believed to be responsible for the generation of
abundant MITE-like elements in an early primate ancestor. These results further
suggest that some MITE families, which are highly reiterated in plant, insect,
and human genomes, could have arisen from a similar mechanism, implicating pogo
like elements.
PMID- 10779534
TI - Expansion and molecular evolution of the interferon-induced 2'-5' oligoadenylate
synthetase gene family.
AB - The mammalian 2'-5' oligoadenylate synthetases (2'-5'OASs) are enzymes that are
crucial in the interferon-induced antiviral response. They catalyze the
polymerization of ATP into 2'-5'-linked oligoadenylates which activate a
constitutively expressed latent endonuclease, RNaseL, to block viral replication
at the level of mRNA degradation. A molecular evolutionary analysis of available
OAS sequences suggests that the vertebrate genes are members of a multigene
family with its roots in the early history of tetrapods. The modern mammalian 2'
5'OAS genes underwent successive gene duplication events resulting in three size
classes of enzymes, containing one, two, or three homologous domains. Expansion
of the OAS gene family occurred by whole-gene duplications to increase gene
content and by domain couplings to produce the multidomain genes. Evolutionary
analyses show that the 2'-5'OAS genes in rodents underwent gene duplications as
recently as 11 MYA and predict the existence of additional undiscovered OAS genes
in mammals.
PMID- 10779535
TI - Terminal-sequence conservation identifies spliceosomal introns in ascomycete 18S
RNA genes.
AB - Twenty-four new insertions were obtained from seven different locations in the
nuclear 18S rDNA for seven species of the lichen-forming fungal genus PHYSCONIA:
They were analyzed allowing for terminal sequence conservation by adopting a
flexible approach to exact insertion site position, and they were compared with
12 previously reported small insertion sequences from the 18S ribosomal RNA gene.
Such insertions have previously been proposed to be degenerate self-splicing
group I introns; however, the methodology used here identified consensus terminal
sequences characteristic of spliceosomal introns. This finding is the first
suggestion that multiple spliceosomal introns occur in ribosomal genes.
PMID- 10779536
TI - Human population expansion and microsatellite variation.
AB - Polymorphisms at di-, tri-, and tetranucleotide microsatellite loci have been
analyzed in 14 worldwide populations. A statistical index of population
expansion, denoted S(k), is introduced to detect historical changes in population
size using the variation at the microsatellites. The index takes the value 0 at
equilibrium with constant population size and is positive or negative according
to whether the population is expanding or contracting, respectively. The use of
S(k) requires estimation of properties of the mutation distribution for which we
use both family data of Dib et al. for dinucleotide loci and our population data
on tri- and tetranucleotide loci. Statistical estimates of the expansion index,
as well as their confidence intervals from bootstrap resampling, are provided. In
addition, a dynamical analysis of S(k) is presented under various assumptions on
population growth or decline. The studied populations are classified as having
high, intermediate, or low values of S(k) and genetic variation, and we use these
to interpret the data in terms of possible population dynamics. Observed values
of S(k) for samples of di-, tri-, and tetranucleotide data are compatible with
population expansion earlier than 60,000 years ago in Africa, Asia, and Europe if
the initial population size before the expansion was on the order of 500. Larger
initial population sizes force the lower bound for the time since expansion to be
much earlier. We find it unlikely that bottlenecks occurred in Central African,
East Asian, or European populations, and the estimated expansion times are rather
similar for all of these populations. This analysis presented here suggests that
modern human populations departed from Africa long before they began to expand in
size. Subsequently, the major groups (the African, East Asian, and European
groups) started to grow at approximately same time. Populations of South America
and Oceania show almost no growth. The Mbuti population from Zaire appears to
have experienced a bottleneck during its expansion.
PMID- 10779537
TI - Evolutionary lineages of RT1.Ba in the Australian Rattus.
AB - In this study, the evolutionary history of the variable second exon of RT1.Ba and
its adjoining intron b are compared across a number of species and subspecies of
the Australian RATTUS: Three lineages are identified in the second intron across
a range of Rattus species. Two of these lineages, separated by the insertion of a
probable rodent short interspersed nucleotide element and by point mutations
outside the indel region, are both found in each of the major clades of the
endemic Australian RATTUS: This pattern of ancestral polymorphism is reflected in
the adjoining exon 2 sequences, although phylogenetic constraints confirm that
the clustering is not identical to that of the associated intron sequences. In
addition, the coding sequences show evidence of the retention of ancestral
polymorphism, with identical exon sequences found in two divergent species, and
some indication of gene conversion detected for the exon sequences.
PMID- 10779538
TI - Phylogeny and divergence times in Pinaceae: evidence from three genomes.
AB - In Pinaceae, the chloroplast, mitochondrial, and nuclear genomes are paternally,
maternally, and biparentally inherited, respectively. Examining congruence and
incongruence of gene phylogenies among the three genomes should provide insights
into phylogenetic relationships within the family. Here we studied intergeneric
relationships of Pinaceae using sequences of the chloroplast matK gene, the
mitochondrial nad5 gene, and the low-copy nuclear gene 4CL. The 4CL gene may
exist as a single copy in some species of Pinaceae, but it constitutes a small
gene family with two or three members in others. Duplication and deletion of the
4CL gene occurred at a tempo such that paralogous loci are maintained within but
not between genera. Exons of the 4CL gene have diverged approximately twice as
fast as the matK gene and five times more rapidly than the nad5 gene. The
partition-homogeneity test indicates that the three data sets are homogeneous. A
combined analysis of the three gene sequences generated a well-resolved and
strongly supported phylogeny. The combined phylogeny, which is topologically
congruent with the three individual gene trees based on the Templeton test, is
likely to represent the organismal phylogeny of Pinaceae. This phylogeny agrees
to a certain extent with previous phylogenetic hypotheses based on morphological,
anatomical, and immunological data. Disagreement between the previous hypotheses
and the three-genome phylogeny suggests that morphology of both vegetative and
reproductive organs has undergone convergent evolution within the pine family.
The strongly supported monophyly of Nothotsuga longibracteata, Tsuga mertensiana,
and Tsuga canadensis on all three gene phylogenies provides evidence against
previous hypotheses of intergeneric hybrid origins of N. longibracteata and T.
mertensiana. Divergence times of the genera were estimated based on sequence
divergence of the matK gene, and they correspond well with the fossil record.
PMID- 10779539
TI - Error, bias, and long-branch attraction in data for two chloroplast photosystem
genes in seed plants.
AB - Sequences of two chloroplast photosystem genes, psaA and psbB, together
comprising about 3,500 bp, were obtained for all five major groups of extant seed
plants and several outgroups among other vascular plants. Strongly supported, but
significantly conflicting, phylogenetic signals were obtained in parsimony
analyses from partitions of the data into first and second codon positions versus
third positions. In the former, both genes agreed on a monophyletic gymnosperms,
with Gnetales closely related to certain conifers. In the latter, Gnetales are
inferred to be the sister group of all other seed plants, with gymnosperms
paraphyletic. None of the data supported the modern "anthophyte hypothesis,"
which places Gnetales as the sister group of flowering plants. A series of
simulation studies were undertaken to examine the error rate for parsimony
inference. Three kinds of errors were examined: random error, systematic bias
(both properties of finite data sets), and statistical inconsistency owing to
long-branch attraction (an asymptotic property). Parsimony reconstructions were
extremely biased for third-position data for psbB. Regardless of the true
underlying tree, a tree in which Gnetales are sister to all other seed plants was
likely to be reconstructed for these data. None of the combinations of genes or
partitions permits the anthophyte tree to be reconstructed with high probability.
Simulations of progressively larger data sets indicate the existence of long
branch attraction (statistical inconsistency) for third-position psbB data if
either the anthophyte tree or the gymnosperm tree is correct. This is also true
for the anthophyte tree using either psaA third positions or psbB first and
second positions. A factor contributing to bias and inconsistency is extremely
short branches at the base of the seed plant radiation, coupled with extremely
high rates in Gnetales and nonseed plant outgroups.
PMID- 10779540
TI - Appropriate likelihood ratio tests and marginal distributions for evolutionary
tree models with constraints on parameters.
AB - We show how to make appropriate likelihood ratio tests for evolutionary tree
models when parameters such as edge (internodes or branches) lengths have
nonnegativity constraints. In such cases, under the null model of an edge length
being zero, the marginal distribution of this parameter is proven to be a "half
normal", that is, 50% zero values and 50% the positive half of a normal
distribution. Other constrained parameters, such as the proportion of invariant
sites, give similar results. To make likelihood ratio tests between nested
models, e.g., H(0): homogeneous site rates, and H(1): site rates follow a gamma
distribution with variance 1/k, then asymptotically as sequence length increases,
the distribution under H(0) becomes a mixture of chi distributions, in this case
50% chi(0), and 50% chi(1) (where the subscript denotes degrees of freedom, i.e.
, not the usually assumed 100% chi(1); which leads to a conservative test). Such
mixtures are sometimes called distributions. Simulations show that even with
sequences as short as 125 sites, some parameters, including the proportion of
invariant sites, fit asymptotic distributions closely.
PMID- 10779541
TI - Sex chromosomal transposable element accumulation and male-driven substitutional
evolution in humans.
AB - We sequenced the genomic region containing the human Y-linked zinc finger gene
(ZFY). Comparison of ZFY to the related region on the X chromosome (ZFX) and to
autosomal sequences reveals a significant accumulation of transposable elements
on the sex chromosomes. In addition, five times as many retroviruslike elements
(RLEs) are present in the ZFY region as in the ZFX region. Thus, transposable
elements accumulate more rapidly on the sex chromosomes, and the insertion of
RLEs may occur more frequently in the male than in the female germ line. When the
accumulation of substitutions in Alu elements was analyzed, it was found that the
Alu elements at the Y-chromosomal locus diverged significantly faster than those
at the X-chromosomal locus, whereas the divergence of autosomal Alu elements was
intermediate. The male-to-female mutation rate ratio was estimated to be 2.5.
PMID- 10779542
TI - The complete mitochondrial DNA sequence of the horseshoe crab Limulus polyphemus.
AB - We determined the complete 14,985-nt sequence of the mitochondrial DNA of the
horseshoe crab Limulus polyphemus (Arthropoda: Xiphosura). This mtDNA encodes the
13 protein, 2 rRNA, and 22 tRNA genes typical for metazoans. The arrangement of
these genes and about half of the sequence was reported previously; however, the
sequence contained a large number of errors, which are corrected here. The two
strands of Limulus mtDNA have significantly different nucleotide compositions.
The strand encoding most mitochondrial proteins has 1. 25 times as many A's as
T's and 2.33 times as many C's as G's. This nucleotide bias correlates with the
biases in amino acid content and synonymous codon usage in proteins encoded by
different strands and with the number of non-Watson-Crick base pairs in the stem
regions of encoded tRNAs. The sizes of most mitochondrial protein genes in
Limulus are either identical to or slightly smaller than those of their
Drosophila counterparts. The usage of the initiation and termination codons in
these genes seems to follow patterns that are conserved among most arthropod and
some other metazoan mitochondrial genomes. The noncoding region of Limulus mtDNA
contains a potential stem-loop structure, and we found a similar structure in the
noncoding region of the published mtDNA of the prostriate tick Ixodes hexagonus.
A simulation study was designed to evaluate the significance of these secondary
structures; it revealed that they are statistically significant. No significant,
comparable structure can be identified for the metastriate ticks Rhipicephalus
sanguineus and Boophilus microplus. The latter two animals also share a
mitochondrial gene rearrangement and an unusual structure of mt-tRNA(C) that is
exactly the same association of changes as previously reported for a group of
lizards. This suggests that the changes observed are not independent and that the
stem-loop structure found in the noncoding regions of Limulus and Ixodes mtDNA
may play the same role as that between trnN and trnC in vertebrates, i.e., the
role of lagging strand origin of replication.
PMID- 10779543
TI - Patterns of diversity among SINE elements isolated from three Y-chromosome genes
in carnivores.
PMID- 10779544
TI - How molecules evolve in eubacteria.
PMID- 10779545
TI - 5-lipoxygenase is phosphorylated by p38 kinase-dependent MAPKAP kinases.
AB - 5-lipoxygenase (5-LO) catalyzes the initial steps in the formation of
leukotrienes, a group of inflammatory mediators derived from arachidonic acid
(AA). Here we describe that activation of p38 mitogen-activated protein kinase in
human polymorphonuclear leukocytes and in Mono Mac 6 cells leads to activation of
downstream kinases, which can subsequently phosphorylate 5-LO in vitro. Different
agents activated the 5-LO kinase activities, including stimuli for cellular
leukotriene biosynthesis (A23187, thapsigargin, N-formyl-leucyl-phenylalanine),
compounds that up-regulate the capacity for leukotriene biosynthesis (phorbol 12
myristate 13-acetate, tumor necrosis factor alpha, granulocyte/macrophage colony
stimulating factor), and well known p38 stimuli as sodium arsenite and sorbitol.
For all stimuli, 5-LO kinase activation was counteracted by SB203580 (3 microM or
less), an inhibitor of p38 kinase. At least two p38-dependent 5-LO kinase
activities were found. Based on migration properties in in-gel kinase assays and
immunoreactivity, one of these was identified as mitogen-activated protein kinase
activated protein kinase 2 (MAPKAP kinase 2). The other appeared to be MAPKAP
kinase 3; however, it could not be excluded that also other p38-dependent kinases
contributed. When polymorphonuclear leukocytes were incubated with sodium
arsenite (strong activator of 5-LO kinases), platelet-activating factor and
exogenous AA, there was a 4-fold increase in 5-LO activity as compared with
incubations with only platelet-activating factor and AA. This indicates that 5-LO
phosphorylation can be one factor determining cellular 5-LO activity.
PMID- 10779546
TI - Endogenous tumor necrosis factor protects the adult cardiac myocyte against
ischemic-induced apoptosis in a murine model of acute myocardial infarction.
AB - Previous studies have shown that proinflammatory cytokines, such as tumor
necrosis factor (TNF), are expressed after acute hemodynamic overloading and
myocardial ischemia/infarction. To define the role of TNF in the setting of
ischemia/infarction, we performed a series of acute coronary artery occlusions in
mice lacking one or both TNF receptors. Left ventricular infarct size was
assessed at 24 h after acute coronary occlusion by triphenyltetrazolium chloride
(TTC) staining in wild-type (both TNF receptors present) and mice lacking either
the type 1 (TNFR1), type 2 (TNFR2), or both TNF receptors (TNFR1/TNFR2). Left
ventricular infarct size as assessed by TTC staining was significantly greater (P
< 0.005) in the TNFR1/TNFR2-deficient mice (77.2% +/- 15.3%) when compared with
either wild-type mice (46.8% +/- 19.4%) or TNFR1-deficient (47.9% +/- 10.6%) or
TNFR2-deficient (41.6% +/- 16.5%) mice. Examination of the extent of necrosis in
wild-type and TNFR1/TNFR2-deficient mice by anti-myosin Ab staining demonstrated
no significant difference between groups; however, the peak frequency and extent
of apoptosis were accelerated in the TNFR1/TNFR2-deficient mice when compared
with the wild-type mice. The increase in apoptosis in the TNFR1/TNFR2-deficient
mice did not appear to be secondary to a selective up-regulation of the Fas
ligand/receptor system in these mice. These data suggest that TNF signaling gives
rise to one or more cytoprotective signals that prevent and/or delay the
development of cardiac myocyte apoptosis after acute ischemic injury.
PMID- 10779547
TI - Inhibition of calcium/calmodulin kinase II alpha subunit expression results in
epileptiform activity in cultured hippocampal neurons.
AB - Several models that develop epileptiform discharges and epilepsy have been
associated with a decrease in the activity of calmodulin-dependent kinase II.
However, none of these studies has demonstrated a causal relationship between a
decrease in calcium/calmodulin kinase II activity and the development of seizure
activity. The present study was conducted to determine the effect of directly
reducing calcium/calmodulin-dependent kinase activity on the development of
epileptiform discharges in hippocampal neurons in culture. Complimentary
oligonucleotides specific for the alpha subunit of the calcium/calmodulin kinase
were used to decrease the expression of the enzyme. Reduction in kinase
expression was confirmed by Western analysis, immunocytochemistry, and exogenous
substrate phosphorylation. Increased neuronal excitability and frank epileptiform
discharges were observed after a significant reduction in calmodulin kinase II
expression. The epileptiform activity was a synchronous event and was not caused
by random neuronal firing. Furthermore, the magnitude of decreased kinase
expression correlated with the increased neuronal excitability. The data suggest
that decreased calmodulin kinase II activity may play a role in epileptogenesis
and the long-term plasticity changes associated with the development of
pathological seizure activity and epilepsy.
PMID- 10779548
TI - In vitro evolution of a T cell receptor with high affinity for peptide/MHC.
AB - T cell receptors (TCRs) exhibit genetic and structural diversity similar to
antibodies, but they have binding affinities that are several orders of magnitude
lower. It has been suggested that TCRs undergo selection in vivo to maintain
lower affinities. Here, we show that there is not an inherent genetic or
structural limitation on higher affinity. Higher-affinity TCR variants were
generated in the absence of in vivo selective pressures by using yeast display
and selection from a library of Valpha CDR3 mutants. Selected mutants had greater
than 100-fold higher affinity (K(D) approximately 9 nM) for the peptide/MHC
ligand while retaining a high degree of peptide specificity. Among the high
affinity TCR mutants, a strong preference was found for CDR3alpha that contained
Pro or Gly residues. Finally, unlike the wild-type TCR, a soluble monomeric form
of a high-affinity TCR was capable of directly detecting peptide/MHC complexes on
antigen-presenting cells. These findings prove that affinity maturation of TCRs
is possible and suggest a strategy for engineering TCRs that can be used in
targeting specific peptide/MHC complexes for diagnostic and therapeutic purposes.
PMID- 10779549
TI - Increased IGF-II protein affects p57kip2 expression in vivo and in vitro:
implications for Beckwith-Wiedemann syndrome.
AB - In both human and mouse, the Igf2 gene, localized on chromosomes 11 and 7,
respectively, is expressed from the paternally inherited chromosome in the
majority of tissues. Insulin-like growth factor-II (IGF-II) plays an important
role in embryonic growth, and aberrant IGF2 expression has been documented in
several human pathologies, such as Beckwith-Wiedemann syndrome (BWS), and a wide
variety of tumors. Human and mouse genetic data strongly implicate another gene,
CDKN1C (p57(kip2)), located in the same imprinted gene cluster on human
chromosome II, in BWS. p57(KIP2) is a cyclin-dependent kinase inhibitor and is
required for normal mouse embryonic development. Mutations in CDKN1C (p57(kip2))
have been identified in a small proportion of patients with BWS, and removal of
the gene from mice by targeted mutagenesis produces a phenotype with elements in
common with this overgrowth syndrome. Patients with BWS with biallelic expression
of IGF2 or with a CDKN1C (p57(kip2)) mutation, as well as overlapping phenotypes
observed in two types of mutant mice, the p57(kip2) knockout and IGF-II
overexpressing mice, strongly suggest that the genes may act in a common pathway
of growth control in situations where Igf2 expression is abnormal. Herein, we
show that p57(kip2) expression is reduced on IGF-II treatment of primary embryo
fibroblasts in a dose-dependent manner. In addition, p57(kip2) expression is down
regulated in mice with high serum levels of IGF-II. These data suggest that the
effects of increased IGF-II in BWS may, in part, be mediated through a decrease
in p57(kip2) gene expression.
PMID- 10779550
TI - The role of members of the pertussis toxin-sensitive family of G proteins in
coupling receptors to the activation of the G protein-gated inwardly rectifying
potassium channel.
AB - Inwardly rectifying potassium (K(+)) channels gated by G proteins (Kir3.x family)
are widely distributed in neuronal, atrial, and endocrine tissues and play key
roles in generating late inhibitory postsynaptic potentials, slowing the heart
rate and modulating hormone release. They are directly activated by G(betagamma)
subunits released from G protein heterotrimers of the G(i/o) family upon
appropriate receptor stimulation. Here we examine the role of isoforms of
pertussis toxin (PTx)-sensitive G protein alpha subunits (G(ialpha1-3) and
G(oalphaA)) in mediating coupling between various receptor systems (A(1),
alpha(2A), D(2S), M(4), GABA(B)1a+2, and GABA(B)1b+2) and the cloned counterpart
of the neuronal channel (Kir3.1+3.2A). The expression of mutant PTx-resistant
G(i/oalpha) subunits in PTx-treated HEK293 cells stably expressing Kir3.1+3.2A
allows us to selectively investigate that coupling. We find that, for those
receptors (A(1), alpha(2A)) known to interact with all isoforms, G(ialpha1-3) and
G(oalphaA) can all support a significant degree of coupling to Kir3.1+3.2A. The
M(4) receptor appears to preferentially couple to G(ialpha2) while another group
of receptors (D(2S), GABA(B)1a+2, GABA(B)1b+2) activates the channel
predominantly through G(betagamma) liberated from G(oA) heterotrimers.
Interestingly, we have also found a distinct difference in G protein coupling
between the two splice variants of GABA(B)1. Our data reveal selective pathways
of receptor activation through different G(i/oalpha) isoforms for stimulation of
the G protein-gated inwardly rectifying K(+) channel.
PMID- 10779551
TI - Xenopus kielin: A dorsalizing factor containing multiple chordin-type repeats
secreted from the embryonic midline.
AB - The midline tissues are important inductive centers of early vertebrate embryos.
By signal peptide selection screening, we isolated a secreted factor, Kielin,
which contains multiple cys-rich repeats similar to those in chordin (Chd).
Expression of Kielin starts at midgastrula stages in the notochord and is
detected in the floor plate of neurula embryos. Kielin is induced in mesoderm and
in ectoderm by nodal-related genes. Chd is sufficient to activate Kielin
expression in mesoderm whereas Shh or HNF-3beta in addition to Chd is required
for induction in ectoderm. Kielin has a distinct biological activity from that of
Chd. Injection of Kielin mRNA causes dorsalization of ventral marginal zone
explants and expansion of MyoD expression in neurula embryos. Unlike Chd, Kielin
does not efficiently induce neural differentiation of animal cap ectoderm,
suggesting that the activity of Kielin is not simply caused by BMP4 blockade.
Kielin is a signaling molecule that mediates inductive activities of the
embryonic midline.
PMID- 10779552
TI - Sodium channel Na(v)1.6 is localized at nodes of ranvier, dendrites, and
synapses.
AB - Voltage-gated sodium channels perform critical roles for electrical signaling in
the nervous system by generating action potentials in axons and in dendrites. At
least 10 genes encode sodium channels in mammals, but specific physiological
roles that distinguish each of these isoforms are not known. One possibility is
that each isoform is expressed in a restricted set of cell types or is targeted
to a specific domain of a neuron or muscle cell. Using affinity-purified isoform
specific antibodies, we find that Na(v)1.6 is highly concentrated at nodes of
Ranvier of both sensory and motor axons in the peripheral nervous system and at
nodes in the central nervous system. The specificity of this antibody was also
demonstrated with the Na(v)1.6-deficient mouse mutant strain med, whose nodes
were negative for Na(v)1.6 immunostaining. Both the intensity of labeling and the
failure of other isoform-specific antibodies to label nodes suggest that Na(v)1.6
is the predominant channel type in this structure. In the central nervous system,
Na(v)1.6 is localized in unmyelinated axons in the retina and cerebellum and is
strongly expressed in dendrites of cortical pyramidal cells and cerebellar
Purkinje cells. Ultrastructural studies indicate that labeling in dendrites is
both intracellular and on dendritic shaft membranes. Remarkably, Na(v)1.6
labeling was observed at both presynaptic and postsynaptic membranes in the
cortex and cerebellum. Thus, a single sodium channel isoform is targeted to
different neuronal domains and can influence both axonal conduction and synaptic
responses.
PMID- 10779553
TI - Gain of imprinting at chromosome 11p15: A pathogenetic mechanism identified in
human hepatocarcinomas.
AB - Genomic imprinting is a reversible condition that causes parental-specific
silencing of maternally or paternally inherited genes. Analysis of DNA and RNA
from 52 human hepatocarcinoma samples revealed abnormal imprinting of genes
located at chromosome 11p15 in 51% of 37 informative samples. The most frequently
detected abnormality was gain of imprinting, which led to loss of expression of
genes present on the maternal chromosome. As compared with matched normal liver
tissue, hepatocellular carcinomas showed extinction or significant reduction of
expression of one of the alleles of the CDKN1C, SLC22A1L, and IGF2 genes. Loss of
maternal-specific methylation at the KvDMR1 locus in hepatocarcinoma correlated
with abnormal expression of CDKN1C and IGF2, suggesting a function for KvDMR1 as
a long-range imprinting center active in adult tissues. These results point to
the role of epigenetic mechanisms leading to loss of expression of imprinted
genes at chromosome region 11p15 in human tumors.
PMID- 10779554
TI - Preservation of myocardial beta-adrenergic receptor signaling delays the
development of heart failure after myocardial infarction.
AB - When the heart fails, there is often a constellation of biochemical alterations
of the beta-adrenergic receptor (betaAR) signaling system, leading to the loss of
cardiac inotropic reserve. betaAR down-regulation and functional uncoupling are
mediated through enhanced activity of the betaAR kinase (betaARK1), the
expression of which is increased in ischemic and failing myocardium. These
changes are widely viewed as representing an adaptive mechanism, which protects
the heart against chronic activation. In this study, we demonstrate, using in
vivo intracoronary adenoviral-mediated gene delivery of a peptide inhibitor of
betaARK1 (betaARKct), that the desensitization and down-regulation of betaARs
seen in the failing heart may actually be maladaptive. In a rabbit model of heart
failure induced by myocardial infarction, which recapitulates the biochemical
betaAR abnormalities seen in human heart failure, delivery of the betaARKct
transgene at the time of myocardial infarction prevents the rise in betaARK1
activity and expression and thereby maintains betaAR density and signaling at
normal levels. Rather than leading to deleterious effects, cardiac function is
improved, and the development of heart failure is delayed. These results appear
to challenge the notion that dampening of betaAR signaling in the failing heart
is protective, and they may lead to novel therapeutic strategies to treat heart
disease via inhibition of betaARK1 and preservation of myocardial betaAR
function.
PMID- 10779555
TI - Uncompensated polyuria in a mouse model of Bartter's syndrome.
AB - We have used homologous recombination to disrupt the mouse gene coding for the
NaK2Cl cotransporter (NKCC2) expressed in kidney epithelial cells of the thick
ascending limb and macula densa. This gene is one of several that when mutated
causes Bartter's syndrome in humans, a syndrome characterized by severe polyuria
and electrolyte imbalance. Homozygous NKCC2-/- pups were born in expected numbers
and appeared normal. However, by day 1 they showed signs of extracellular volume
depletion (hematocrit 51%; wild type 37%). They subsequently failed to thrive. By
day 7, they were small and markedly dehydrated and exhibited renal insufficiency,
high plasma potassium, metabolic acidosis, hydronephrosis of varying severity,
and high plasma renin concentrations. None survived to weaning. Treatment of -/-
pups with indomethacin from day 1 prevented growth retardation and 10% treated
for 3 weeks survived, although as adults they exhibited severe polyuria (10
ml/day), extreme hydronephrosis, low plasma potassium, high blood pH,
hypercalciuria, and proteinuria. Wild-type mice treated with furosemide, an
inhibitor of NaK2Cl cotransporters, have a phenotype similar to the indomethacin
rescued -/- adults except that hydronephrosis was mild. The polyuria,
hypercalciuria, and proteinuria of the -/- adults and furosemide-treated wild
type mice were unresponsive to inhibitors of the renin angiotensin system,
vasopressin, and further indomethacin. Thus absence of NKCC2 in the mouse causes
polyuria that is not compensated elsewhere in the nephron. The NKCC2 mutant
animals should be valuable for uncovering new pathophysiologic and therapeutic
aspects of genetic disturbances in water and electrolyte recovery by the kidney.
PMID- 10779556
TI - An autologous oral DNA vaccine protects against murine melanoma.
AB - We demonstrated that peripheral T cell tolerance toward murine melanoma self
antigens gp100 and TRP-2 can be broken by an autologous oral DNA vaccine
containing the murine ubiquitin gene fused to minigenes encoding peptide epitopes
gp100(25-33) and TRP-2(181-188). These epitopes contain dominant anchor residues
for MHC class I antigen alleles H-2D(b) and H-2K(b), respectively. The DNA
vaccine was delivered by oral gavage by using an attenuated strain of Salmonella
typhimurium as carrier. Tumor-protective immunity was mediated by MHC class I
antigen-restricted CD8(+) T cells that secreted T(H)1 cytokine IFN-gamma and
induced tumor rejection and growth suppression after a lethal challenge with
B16G3. 26 murine melanoma cells. Importantly, the protective immunity induced by
this autologous DNA vaccine against murine melanoma cells was at least equal to
that achieved through xenoimmunization with the human gp100(25-33) peptide, which
differs in its three NH(2)-terminal amino acid residues from its murine
counterpart and was previously reported to be clearly superior to an autologous
vaccine in inducing protective immunity. The presence of ubiquitin upstream of
the minigene proved to be essential for achieving this tumor-protective immunity,
suggesting that effective antigen processing and presentation may make it
possible to break peripheral T cell tolerance to a self-antigen. This vaccine
design might prove useful for future rational designs of other recombinant DNA
vaccines targeting tissue differentiation antigens expressed by tumors.
PMID- 10779557
TI - Characterization of PDZ-binding kinase, a mitotic kinase.
AB - hDlg, the human homologue of the Drosophila Discs-large (Dlg) tumor suppressor
protein, is known to interact with the tumor suppressor protein APC and the human
papillomavirus E6 transforming protein. In a two-hybrid screen, we identified a
322-aa serine/threonine kinase that binds to the PDZ2 domain of hDlg. The mRNA
for this PDZ-binding kinase, or PBK, is most abundant in placenta and absent from
adult brain tissue. The protein sequence of PBK has all the characteristic
protein kinase subdomains and a C-terminal PDZ-binding T/SXV motif. In vitro, PBK
binds specifically to PDZ2 of hDlg through its C-terminal T/SXV motif. PBK and
hDlg are phosphorylated at mitosis in HeLa cells, and the mitotic phosphorylation
of PBK is required for its kinase activity. In vitro, cdc2/cyclin B
phosphorylates PBK. This evidence shows how PBK could link hDlg or other PDZ
containing proteins to signal transduction pathways regulating the cell cycle or
cellular proliferation.
PMID- 10779558
TI - The Gcd10p/Gcd14p complex is the essential two-subunit tRNA(1-methyladenosine)
methyltransferase of Saccharomyces cerevisiae.
AB - The modified nucleoside 1-methyladenosine (m(1)A) is found at position 58 in the
TPsiC loop of many eukaryotic tRNAs. The absence of m(1)A from all tRNAs in
Saccharomyces cerevisiae mutants lacking Gcd10p elicits severe defects in
processing and stability of initiator methionine tRNA (tRNA(i)(Met)). Gcd10p is
found in a complex with Gcd14p, which contains conserved motifs for binding S
adenosylmethionine (AdoMet). These facts, plus our demonstration that gcd14Delta
cells lacked m(1)A, strongly suggested that Gcd10p/Gcd14p complex is the yeast
tRNA(m(1)A)methyltransferase [(m(1)A)MTase]. Supporting this prediction, affinity
purified Gcd10p/Gcd14p complexes used AdoMet as a methyl donor to synthesize
m(1)A in either total tRNA or purified tRNA(i)(Met) lacking only this
modification. Kinetic analysis of the purified complex revealed K(M) values for
AdoMet or tRNA(i)(Met) of 5.0 microM and 2.5 nM, respectively. Mutations in the
predicted AdoMet-binding domain destroyed GCD14 function in vivo and (m(1)A)MTase
activity in vitro. Purified Flag-tagged Gcd14p alone had no enzymatic activity
and was severely impaired for tRNA-binding compared with the wild-type complex,
suggesting that Gcd10p is required for tight binding of the tRNA substrate. Our
results provide a demonstration of a two-component tRNA MTase and suggest that
binding of AdoMet and tRNA substrates depends on different subunits of the
complex.
PMID- 10779559
TI - Cortical cell death induced by IL-1 is mediated via actions in the hypothalamus
of the rat.
AB - The cytokine IL-1 mediates diverse forms of neurodegeneration, but its mechanism
of action is unknown. We have demonstrated previously that exogenous and
endogenous IL-1 acts specifically in the rat striatum to dramatically enhance
ischemic and excitotoxic brain damage and cause extensive cortical injury. Here
we tested the hypothesis that this distant effect of IL-1 is mediated through
polysynaptic striatal outputs to the cortex via the hypothalamus. We show that IL
1beta injected into the rat striatum with the excitotoxin alpha-amino-3-hydroxy-5
methyl-4-isoxazolepropionate (S-AMPA) caused increased expression of IL-1beta
(mRNA and protein) mainly in the cortex where maximum injury occurs. Marked
increases in IL-1beta mRNA and protein were also observed in the hypothalamus. S
AMPA, injected alone into the striatum, caused only localized damage, but
administration of IL-1beta into either the striatum or the lateral hypothalamus
immediately after striatal S-AMPA resulted in widespread cell loss throughout the
ipsilateral cortex. Finally we showed that the cortical cell death produced by
striatal coinjection of S-AMPA and IL-1beta was significantly reduced by
administration of the IL-1 receptor antagonist into the lateral hypothalamus.
These data suggest that IL-1beta can act in the hypothalamus to modify cell
viability in the cortex. We conclude that IL-1-dependent pathways project from
the striatum to the cortex via the hypothalamus and lead to cortical injury, and
that these may contribute to a number of human neurological conditions including
stroke and head trauma.
PMID- 10779560
TI - Nuclear structure in normal and Bloom syndrome cells.
AB - Bloom syndrome (BS) is a rare cancer-predisposing disorder in which the cells of
affected persons have a high frequency of somatic mutation and genomic
instability. BLM, the protein altered in BS, is a RecQ DNA helicase. This report
shows that BLM is found in the nucleus of normal human cells in the nuclear
domain 10 or promyelocytic leukemia nuclear bodies. These structures are punctate
depots of proteins disrupted upon viral infection and in certain human
malignancies. BLM is found primarily in nuclear domain 10 except during S phase
when it colocalizes with the Werner syndrome gene product, WRN, in the nucleolus.
BLM colocalizes with a select subset of telomeres in normal cells and with large
telomeric clusters seen in simian virus 40-transformed normal fibroblasts. During
S phase, BS cells expel micronuclei containing sites of DNA synthesis. BLM is
likely to be part of a DNA surveillance mechanism operating during S phase.
PMID- 10779561
TI - The fourth chromosome of Drosophila melanogaster: interspersed euchromatic and
heterochromatic domains.
AB - The small fourth chromosome of Drosophila melanogaster (3.5% of the genome)
presents a puzzle. Cytological analysis suggests that the bulk of the fourth,
including the portion that appears banded in the polytene chromosomes, is
heterochromatic; the banded region includes blocks of middle repetitious DNA
associated with heterochromatin protein 1 (HP1). However, genetic screens
indicate 50-75 genes in this region, a density similar to that in other
euchromatic portions of the genome. Using a P element containing an hsp70-white
gene and a copy of hsp26 (marked with a fragment of plant DNA designated pt), we
have identified domains that allow for full expression of the white marker (R
domains), and others that induce a variegating phenotype (V domains). In the
former case, the hsp26-pt gene shows an accessibility and heat-shock-inducible
activity similar to that seen in euchromatin, whereas in the latter case,
accessibility and inducible expression are reduced to levels typical of
heterochromatin. Mapping by in situ hybridization and by hybridization of
flanking DNA sequences to a collection of cosmid and bacterial artificial
chromosome clones shows that the R domains (euchromatin-like) and V domains
(heterochromatin-like) are interspersed. Examination of the effect of genetic
modifiers on the variegating transgenes shows some differences among these
domains. The results suggest that heterochromatic and euchromatic domains are
interspersed and closely associated within this 1.2-megabase region of the
genome.
PMID- 10779562
TI - The phylogeny of closely related species as revealed by the genealogy of a
speciation gene, Odysseus.
AB - Molecular differentiation between races or closely related species is often
incongruent with the reproductive divergence of the taxa of interest. Shared
ancient polymorphism and/or introgression during secondary contact may be
responsible for the incongruence. At loci contributing to speciation, these two
complications should be minimized (1, 2); hence, their variation may more
faithfully reflect the history of the species' reproductive differentiation. In
this study, we analyzed DNA polymorphism at the Odysseus (OdsH) locus of hybrid
sterility between Drosophila mauritiana and Drosophila simulans and were able to
verify such a prediction. Interestingly, DNA variation only a short distance away
(1.8 kb) appears not to be influenced by the forces that shape the recent
evolution of the OdsH coding region. This locus thus may represent a test case of
inferring phylogeny of very closely related species.
PMID- 10779563
TI - Early-life exposure to endotoxin alters hypothalamic-pituitary-adrenal function
and predisposition to inflammation.
AB - We have investigated whether exposure to Gram-negative bacterial endotoxin in
early neonatal life can alter neuroendocrine and immune regulation in adult
animals. Exposure of neonatal rats to a low dose of endotoxin resulted in long
term changes in hypothalamic-pituitary-adrenal (HPA) axis activity, with elevated
mean plasma corticosterone concentrations that resulted from increased
corticosterone pulse frequency and pulse amplitude. In addition to this marked
effect on the development of the HPA axis, neonatal endotoxin exposure had long
lasting effects on immune regulation, including increased sensitivity of
lymphocytes to stress-induced suppression of proliferation and a remarkable
protection from adjuvant-induced arthritis. These findings demonstrate a potent
and long-term effect of neonatal exposure to inflammatory stimuli that can
program major changes in the development of both neuroendocrine and immunological
regulatory mechanisms.
PMID- 10779564
TI - Growth of new brainstem connections in adult monkeys with massive sensory loss.
AB - Somatotopic maps in the cortex and the thalamus of adult monkeys and humans
reorganize in response to altered inputs. After loss of the sensory afferents
from the forelimb in monkeys because of transection of the dorsal columns of the
spinal cord, therapeutic amputation of an arm or transection of the dorsal roots
of the peripheral nerves, the deprived portions of the hand and arm
representations in primary somatosensory cortex (area 3b), become responsive to
inputs from the face and any remaining afferents from the arm. Cortical and
subcortical mechanisms that underlie this reorganization are uncertain and appear
to be manifold. Here we show that the face afferents from the trigeminal nucleus
of the brainstem sprout and grow into the cuneate nucleus in adult monkeys after
lesions of the dorsal columns of the spinal cord or therapeutic amputation of an
arm. This growth may underlie the large-scale expansion of the face
representation into the hand region of somatosensory cortex that follows such
deafferentations.
PMID- 10779566
TI - 5-methylcytosine-DNA glycosylase activity is present in a cloned G/T mismatch DNA
glycosylase associated with the chicken embryo DNA demethylation complex.
AB - We previously have shown that DNA demethylation by chicken embryo 5
methylcytosine DNA glycosylase (5-MCDG) needs both RNA and proteins. One of these
proteins is a RNA helicase. Further peptides were sequenced, and three of them
are identical to the mammalian G/T mismatch DNA glycosylase. A 3,233-bp cDNA
coding for the chicken homologue of human G/T mismatch DNA glycosylase was
isolated and sequenced. The derived amino acid sequence (408 aa) shows 80%
identity with the human G/T mismatch DNA glycosylase, and both the C and N
terminal parts have about 50% identity. As for the highly purified chicken embryo
DNA demethylation complex the recombinant protein expressed in Escherichia coli
has both G/T mismatch and 5-MCDG activities. The recombinant protein has the same
substrate specificity as the chicken embryo 5-MCDG where hemimethylated DNA is a
better substrate than symmetrically methylated CpGs. The activity ratio of G/T
mismatch and 5-MCDG is about 30:1 for the recombinant protein expressed in E.
coli and 3:1 for the purified enzyme from chicken embryos. The incubation of a
recombinant CpG-rich RNA isolated from the purified DNA demethylation complex
with the recombinant enzyme strongly inhibits G/T mismatch glycosylase while
slightly stimulating the activity of 5-MCDG. Deletion mutations indicate that G/T
mismatch and 5-MCDG activities share the same areas of the N- and C-terminal
parts of the protein. In reconstitution experiments RNA helicase in the presence
of recombinant RNA and ATP potentiates the activity of 5-MCDG.
PMID- 10779567
TI - National security and scientific communication.
PMID- 10779568
TI - Purification and characterisation of a novel cysteine conjugate beta-lyase from
the tapeworm Moniezia expansa.
AB - The paper presents the first report of the purification of an invertebrate
cysteine conjugate beta-lyase (CCBL). CCBL activity was shown to predominate
within the cytosolic fraction of tissue from the tapeworm Moniezia expansa. The
monomeric cytosolic enzyme was isolated with a M(r) of 72 kDa and co-purified
with transaminase activity towards L-aspartate. The substrate profile for M.
expansa CCBL is different from that of mammalian CCBLs. Exploiting the
differences in mammalian and parasite substrate profiles will facilitate the
development of helminth targeted conjugates which will not be activated by host
(mammalian) CCBLs.
PMID- 10779565
TI - A binding pocket for a small molecule inhibitor of HIV-1 entry within the
transmembrane helices of CCR5.
AB - HIV-1 entry into CD4(+) cells requires the sequential interactions of the viral
envelope glycoproteins with CD4 and a coreceptor such as the chemokine receptors
CCR5 and CXCR4. A plausible approach to blocking this process is to use small
molecule antagonists of coreceptor function. One such inhibitor has been
described for CCR5: the TAK-779 molecule. To facilitate the further development
of entry inhibitors as antiviral drugs, we have explored how TAK-779 acts to
prevent HIV-1 infection, and we have mapped its site of interaction with CCR5. We
find that TAK-779 inhibits HIV-1 replication at the membrane fusion stage by
blocking the interaction of the viral surface glycoprotein gp120 with CCR5. We
could identify no amino acid substitutions within the extracellular domain of
CCR5 that affected the antiviral action of TAK-779. However, alanine scanning
mutagenesis of the transmembrane domains revealed that the binding site for TAK
779 on CCR5 is located near the extracellular surface of the receptor, within a
cavity formed between transmembrane helices 1, 2, 3, and 7.
PMID- 10779569
TI - Allopatric combination of Fasciola hepatica and Lymnaea truncatula is more
efficient than sympatric ones.
AB - Parasites are capable of rapid evolutionary changes relative to their hosts, due
to short life cycle, short generation time, and high fecundity. The direction of
the evolution of parasite virulence can be studied in cross-transfer experiments,
combining hosts and parasites from different localities, and comparing the
outcome of established (sympatric and potentially locally adapted) and novel
(allopatric) combinations of hosts and parasites. We aimed to compare the
compatibility with snails hosts, the infectivity of metacercariae in rabbits and
rats, and the fitness among different combinations (French-FF and Spanish-SS
sympatries and allopatry-FS). The first isolate of Fasciola hepatica and its
corresponding intermediate host, Lymnaea truncatula originated from Lugo's
northwestern Spain. The second isolate of parasite and snail was collected in the
Limoges area in central France. The Spanish snails were more susceptible to their
sympatric trematode than the French snails. The Spanish flukes were more
infective to intermediate hosts (snails) than the French flukes, but subsequent
definitive hosts (rats or rabbits) infections remained similar. The estimated
fitness was low in sympatric infections and highly similar (from 4.7 to 5.3). The
fitness similarity corresponds, however, to different variations in life-history
traits that could represent different strategies among the host-parasite local
combinations. The infection rate in snails, metacercarial productivity,
metacercarial infectivity, and the estimated fitness were better for allopatric
combination (FS). The susceptibility data showed a higher efficiency of flukes in
the allopatric snail population than in their local snail population. However,
our results were obtained after one generation and from a single isolate and it
remains to be determined if all allopatric fluke-snail isolates may present a
better fitness. Nevertheless our results indicate that introduction of liver
fluke-infected cattle should be monitored carefully, as it could result in the
introduction of more efficient parasites.
PMID- 10779570
TI - Oceanic barriers as indicated by scombrid fishes and their parasites.
AB - Four genera of scombrid fishes (26 species) and their copepod (32 species) and
monogenean ectoparasites (25 species) were used to test the hypothesis that the
East Pacific Barrier is responsible for the most pronounced break in the circum
tropical warm water fauna of the continental shelves, and not the New World
Barrier. Analysis at the species level showed that there is a primary centre of
diversity in the West Pacific, and a secondary centre in the West Atlantic. The
former, almost entirely, shares its species of the largely coastal Scomberomorus
and Grammatorcynus and their parasites with seas located to the west. Only four
parasites (all copepods) are shared by the East and West Pacific, and they are
circum-tropical. In contrast, the West Pacific shares species of the more pelagic
Scomber and their parasites with seas both to the east and west, although at the
genus level, only two circum-tropical monogenean genera are shared by the E and W
Pacific. We conclude that the East Pacific Barrier has been a 100% or almost 100%
effective barrier to dispersal of species of Scomberomorus, Grammatorcynus and
their parasites, whereas for species of Scomber and their parasites, the East
Pacific has been a less effective barrier.
PMID- 10779571
TI - Purification and properties of an acid phosphatase from Entamoeba histolytica HM
1:IMSS.
AB - Entamoeba histolytica contains and secretes acid phosphatase, which has been
proposed as a virulence factor in some pathogenic microorganisms. In this work,
we purified and characterised a membrane-bound acid phosphatase (MAP) from E.
histolytica HM-1:IMSS and studied the effect of different chemical compounds on
the secreted acid phosphatase and MAP activities. MAP purification was
accomplished by detergent solubilisation, and affinity and ion exchange
chromatographies. The enzyme showed a pI of 5.5-6.2, an optimum pH of 5.5, and a
Km value of 1.14 mM with p-nitrophenyl phosphate.
PMID- 10779572
TI - Trypanosoma cruzi: parasitaemia produced in mice does not seem to be related to
in vitro parasite-cell interaction.
AB - The interaction of Trypanosoma cruzi strains producing subpatent or high
parasitaemia in mice with mouse macrophages, Vero and L929 cells was evaluated
using tissue culture trypomastigotes. Macrophages were the cells most readily
infected while Vero cells presented the highest parasite intracellular
multiplication rates. Subpatent strains were equal or more infective than the
high parasitaemia. Due to the small number of strains, no correlation could be
established between the zymodemes and parasitaemia or parasite-cell interaction
in vitro. However parasitaemia in mice does not seem to be related to in vitro
parasite-cell interaction.
PMID- 10779573
TI - Identification of a 30 kDa antigen from leishmania (L.) chagasi amastigotes
implicated in protective cellular reponses in a murine model.
AB - An antigen of apparent molecular mass of 30 kDa, termed p30, was purified from
Leishmania (L.) chagasi amastigotes after separation of parasite extracts by
sodium dodecyl sulfate-polyacrylamide gel eletroctrophoresis followed by
electroelution. The use of the purified antigen in lymphocyte cultures from
BALB/c mice previously immunised with L. (L.) chagasi amastigotes led to high
levels of proliferation. Animal immunisation with p30 plus complete Freund's
adjuvant either by subcutaneous or intraperitoneal route led to comparable
antigenic stimulation. Similar stimulation indices induced by p30 were also
obtained when animals were immunised with Corynebacterium parvum as adjuvant by
the intraperitoneal route. Detection of IL-2 and IFN-gamma in the supernatants
from lymphocytes stimulated by p30 and inhibition of the production of these
lymphokines in the presence of anti-CD4 strongly indicated the involvement of the
Th1 subset in the responses elicited by p30 antigen. Immunisation of BALB/c mice
with p30 provided partial protection against challenge with L. (L.) chagasi
amastigotes, indicating a protective role for p30 and that Th1 can be related to
accquired resistance to visceral leishmaniasis in a murine model. Further
characterisation studies were performed by the use of a monoclonal antibody
directed to a cysteine proteinase of 30 kDa from L. (L.) amazonensis amastigotes.
Despite the cross-reactivity presented by p30 from both Leishmania species, the
p30 from L. (L.) chagasi amastigotes lacks proteolytic activity.
PMID- 10779574
TI - Isolation of antigen from the circulating immune complex in mice infected with
Plasmodium berghei.
AB - Circulating immune complex (CIC) is known to play a role in pathological
glomerular alterations in malaria. However, the nature of the antigens comprising
the CIC is still not fully understood. We report here the isolation of the
antigen in CIC and its localisation in mice infected with Plasmodium berghei
NK65. The antigen was successfully isolated from CIC extracted from the blood of
mice infected with P. berghei, by using C1q-coated microplates. The molecular
mass of the antigen separated from CIC bound to C1q was found to be 78 kDa.
Furthermore, localisation of the antigen was examined by the fluorescent antibody
technique and immunoelectron microscopy. The antigen was detected in the
parasitised erythrocyte and the mesangial matrix by both methods. These results
suggest that the 78 kDa protein might be associated with the glomerular
alterations in malaria infection.
PMID- 10779575
TI - Biological characterisation of Sarcocystis neurona isolated from a Southern sea
otter (Enhydra lutris nereis).
AB - Sarcocystis neurona was isolated from the brain of a juvenile, male southern sea
otter (Enhydra lutris nereis) suffering from CNS disease. Schizonts and
merozoites in tissue sections of the otter's brain reacted with anti-S. neurona
antiserum immunohistochemically. Development in cell culture was by endopolyogeny
and mature schizonts were first observed at 3 days postinoculation. PCR of
merozoite DNA using primer pairs JNB33/JNB54 and restriction enzyme digestion of
the 1100 bp product with Dra I indicated the organism was S. neurona. Four of
four interferon-gamma gene knockout mice inoculated with merozoites developed S.
neurona-associated encephalitis. Antibodies to S. neurona but not Sarcocystis
falcatula, Toxoplasma gondii, or Neospora caninum were present in the serum of
inoculated mice. This is the first isolation of S. neurona from the brain of a
non-equine host.
PMID- 10779576
TI - Induction cues for tegument formation during the transformation of Schistosoma
mansoni cercariae.
AB - Adult schistosomes are parasitic blood flukes that have a continuous double lipid
bilayered membrane surrounding the entire worm. This tegumental membrane is
synthesised during invasion of the vertebrate host by free-swimming infectious
forms called cercariae. As cercariae invade their final hosts they lose their
tails and encounter a changing environment that includes altered temperature,
sugar concentration and osmolarity. We have identified a glucose transporter
protein designated SGTP4 that is found exclusively in the outer adult tegument
and on membranous vesicles within the tegumental cytoplasm. By using
immunofluorescence analysis to monitor the appearance and distribution of SGTP4
we can track the process of new tegumental membrane formation and examine the
cues that trigger this developmental pathway. Cercariae in water do not transform
their tegument while those incubated in rich medium do so rapidly. We have
examined which of the many constituents of rich medium are responsible for
triggering this transformation. Incubation in a solution of moderate osmolarity
(120 mOsM PBS) is sufficient by itself to trigger tegument transformation, albeit
at a slower rate relative to incubation in rich medium. Adding either glucose (to
100 mM) to the solution or increasing the temperature of incubation (from 22
degrees C to 37 degrees C) further increased the rate of tegument biogenesis. The
introduction of glucose together with an increase in the incubation temperature
further accelerated the process, suggesting that these factors act
synergistically to promote transformation rates. The critical nature of
osmolarity in inducing the process is highlighted by the fact that transformation
proceeds as efficiently in 360 mOsM alone as it does in rich medium. While the
fatty acids linolenic acid (cis-9, cis-12, cis-15-octadecatrienoic acid at 1 mM)
and capric acid (Decanoic acid, at 0.1 mM) have both been proposed to stimulate
tegumental transformation, we show that neither promotes the morphogenesis of a
normal schistosomulum tegument. The schistosomicide praziquantel (to 1 mM) has no
detectable effect on new tegument formation.
PMID- 10779577
TI - Detection of Babesia caballi infection by enzyme-linked immunosorbent assay using
recombinant 48-kDa merozoite rhoptry protein.
AB - The 48-kDa Babesia caballi merozoite rhoptry protein was expressed using a pGEX4T
expression vector in Escherichia coli as glutathione S-transferase fusion protein
(GST-BC48), and the expressed GST-BC48 was used in an ELISA to detect specific
antibodies in serum samples. No cross-reaction was observed with sera from horses
experimentally infected with Babesia equi. GST-BC48 ELISA was a highly sensitive
and specific test when compared with the CFT. A total of 209 horse sera obtained
from Central Mongolia were examined with the GST-BC48 ELISA and 46.4% (97/209)
were found to be seropositive for B. caballi, suggesting that the GST-BC48 ELISA
can be successfully used for both quarantine and epidemiological studies.
PMID- 10779578
TI - Molecular typing of Toxoplasma gondii strains by GRA6 gene sequence analysis.
AB - The utility of sequence polymorphisms in the dense granule antigen GRA6 gene as
typing markers for Toxoplasma gondii was investigated. The coding region of GRA6
was amplified, sequenced and compared for 30 Toxoplasma strains from eight
different zymodemes (Z1-Z8). Sequence alignment identified nucleotide
polymorphisms at 24 positions out of 690 bp, which correlated with murine
virulence. Types I, II, and III could be distinguished from each other on the
basis of three, 10, and six variable positions, respectively. Two deletions of 15
bp and 3 bp existed in the avirulent (type II) strains. With one exception, all
polymorphic positions resulted in amino acid substitutions, and the two gaps of
15 bp and 3 bp caused the deletion of six amino acids in type II strains. Intra
specific polymorphisms were also found in the virulent group. A high degree of
sequence polymorphism correlating with the phenotypes of T. gondii strains points
to the GRA6 gene being a good marker for strain characterisation and typing of
the isolates of this apicomplexan. The large variety of amino acid changes
supports the view that the GRA6 protein plays an important role in the
antigenicity and pathogenicity of T. gondii. The existence of polymorphic
restriction sites for endonuclease MseI was used to develop a PCR-RFLP method
which could simply differentiate the three different groups (types I, II, III) of
T. gondii.
PMID- 10779579
TI - Transcriptional and post-transcriptional in organello labelling of Trypanosoma
brucei mitochondrial RNA.
AB - In organello labelling of Trypanosoma brucei mitochondrial (mt) RNA was
characterised with respect to nucleotide requirements and drug sensitivity.
Mitochondrial transcriptional activity is maximal in the presence of all
ribonucleoside-triphosphate NTPs, and can be inhibited by UTP depletion.
Mitochondrial transcription can also be partially inhibited by actinomycin D
(actD) or ethidium bromide (EtBr). Post-transcriptional UTP incorporation is
insensitive to actinomycin D or ethidium bromide. Proteins were identified that
interact with transcriptional and post-transcriptionally labelled RNAs, and
confirm the in vitro RNA-binding properties discovered for a number of T. brucei
mt proteins. These experiments reveal new strategies for studying mt
transcription and processing in T. brucei mitochondria.
PMID- 10779580
TI - Optimisation of flow cytometric measurement of parasitaemia in plasmodium
infected mice.
AB - Mouse malaria is often used as a model for drug testing. The results of drug
trials are monitored by tedious (and consequently, sometimes inaccurate)
microscopic counting of blood smears, or by flow cytometry. We suggest an
improved, accurate and time-saving flow cytometric method for determination of
parasitaemias in mice infected with Plasmodium vinckei petteri or Plasmodium
berghei. The method involves collection of drops of blood from the tail vein,
fixation, storage, permeabilisation, staining and analysis with a visible range
flow cytometer. Three nucleic acid dyes, YOYO-1, propidium iodide and acridine
orange were compared. YOYO-1 was found to be the best stain for the
discrimination of parasitised erythrocytes from non-infected ones. A good direct
correlation was obtained between parasitaemia determined by conventional
microscopy and parasitaemia measured by flow cytometry. Drug effects could be
assessed by the cytometric method. For the detection of low level of parasitemia,
parasitised cells were treated with RNAse to completely cancel RNA-derived
signals originating from host reticulocytes. This procedure also revealed
discrete peaks arising from red cells infected with multiple parasites or from
parasites with different numbers of nuclei.
PMID- 10779581
TI - DNA evidence that Ostertagia gruehneri and Ostertagia arctica (Nematoda:
ostertagiinae) in reindeer from Norway and Svalbard are conspecific.
AB - DNA sequences of ITS-1 and ITS-2 of rDNA were determined for 16 individual adult
males each of Ostertagia gruehneri and Ostertagia arctica from Svalbard reindeer
(Rangifer tarandus platyrhynchus) and Eurasian tundra reindeer (R. t. tarandus).
Each ITS was virtually identical in O. gruehneri and O. arctica and the three
mixed bases detected were shared by both species. Our results strongly suggest
that O. gruehneri and O. arctica are dimorphic males of the same species.
PMID- 10779582
TI - Phylogenetic position of the monogeneans Sundanonchus, Thaparocleidus, and
Cichlidogyrus inferred from 28S rDNA sequences.
AB - A molecular phylogeny was inferred from newly obtained partial 28S rRNA gene
sequences of Sundanonchus micropeltis (Sundanonchidae), Thaparocleidus siamensis
and Cichlidogyrus sp. (Ancyrocephalidae), and other already available sequences.
Although sequences are lacking for several families, the following phylogenetic
relationships could be inferred. The Diplectanidae were the sister-group to a
clade including Sundanonchus and the Ancyrocephalidae; Sundanonchus was the
sister-group to the Ancyrocephalidae, therefore suggesting validity of the
Sundanonchidae, which include this single genus; within the Ancyrocephalidae,
Thaparocleidus (Ancylodiscoidinae) was the sister-group to the four other taxa,
though with relatively low support, suggesting that the Ancylodiscoidinae are the
sister-group to the Ancyrocephalinae.
PMID- 10779583
TI - Molecular investigation of African isolates of Trichinella reveals genetic
polymorphism in Trichinella nelsoni.
AB - Molecular genetic studies were carried out on three isolates of Trichinella
nelsoni (from Kenya, Tanzania and South Africa) and three isolates of Trichinella
T8 (from South Africa and Namibia) from sylvatic carnivores and from a sylvatic
swine. A probe (pT7.3) specific for T. nelsoni was obtained by screening a pUC18
genomic library. The pT7.3 sequence was 346 bp in length with an AT content of
70%. The sequence is present approximately 200 times per haploid genome. Southern
blot analysis of Hind III digested DNAs of the three isolates of T. nelsoni
revealed that the hybridisation patterns of the isolates from Kenya and Tanzania
were identical and that they differed from that of the isolate from South Africa,
indicating the presence of polymorphism in this species. A pUC18 genomic library
of Trichinella T8 was also screened, and one clone (pT8.3) was found to be
specific for homologous DNA by dot blot, but Southern blot analysis of DNA
samples from eight genotypes showed different hybridisation signals for both
Trichinella T8 and Trichinella britovi DNAs. No differences in the nucleotide
sequences of the expansion segment V were observed for the T. nelsoni isolates.
However, they differed from those of Trichinella T8. The presence of Trichinella
T8 in Africa south of the Sahara and its genetic relationship with T. britovi
remain unclear and warrant detailed investigations.
PMID- 10779584
TI - Parasites and host life-history traits: implications for community ecology and
species co-existence.
AB - Most of the evidence for a key role of parasites in structuring communities is
based on the idea of a differential susceptibility of host species to infection
and its consequences. Recent advances in community ecology suggest that life
history traits of free-living species can be an important determinant of their co
existence within communities. On the other hand, parasites have the potential to
indirectly alter the life-history traits of their hosts, such as developmental
time or dispersal. We discuss the idea that these indirect effects could
influence the structure of free-living and parasite communities. We explore this
idea in relation to related concepts including 'parasitic arbitration' and
engineering processes.
PMID- 10779586
TI - The short forms of HLA-G are unlikely to play a role in pregnancy because they
are not expressed at the cell surface.
AB - HLA-G is a nonclassical class I MHC molecule of unknown function expressed on
human invasive trophoblast. In trophoblast cells, HLA-G mRNA is alternatively
spliced into a variety of forms which are predicted to encode a full length
membrane-bound form, three short membrane-bound isoforms and two soluble
isoforms. The aim of this study was to determine which of these protein isoforms
are translated, which are expressed on the cell surface and which are secreted.
Artificial cDNAs encoding the isoforms were generated by PCR mutagenesis, ligated
to an epitope tag and transfected into a human cell line capable of expressing
MHC class I. Protein products of appropriate sizes were detected in cells
transfected with cDNAs encoding all membrane-bound forms, but surface
biotinylation studies indicated that only full length membrane-bound HLA-G was
present at the cell surface. Full length HLA-G was also detected by surface
antibody binding and flow cytometry. Soluble HLA-G1 was detected in cells
transfected with the appropriate cDNA only after treatment with monensin, which
inhibits transport of glycoproteins through the Golgi apparatus. These results
suggest that full length HLA-G, but not short HLA-G isoforms can be expressed on
the surface of human cells and that soluble HLA-G is rapidly secreted. Thus, it
is likely that the full length membrane-bound and soluble forms of HLA-G are the
only biologically active forms to which the mother is exposed.
PMID- 10779587
TI - Hypothalamo-pituitary control of the cell-mediated immunity in rat embryos: role
of LHRH in regulation of lymphocyte proliferation.
AB - The role of the neuroendocrine system in the development of cell-mediated
immunity has been studied in fetal rats. The spontaneous and mitogen-induced
proliferation of liver lymphocytes and thymocytes was evaluated in vitro in rats
at the 22nd prenatal day following surgical ablation of the forebrain
(encephalectomy) or of the entire brain and pituitary (decapitation) in rat
fetuses in utero at the 18th day. Non-operated and sham-operated fetuses served
as controls. The ablation of the entire brain and pituitary in rat fetuses
resulted in an increase (40-60%) of spontaneous proliferation of liver and thymic
cells in comparison with sham-operated fetuses. The ablation of the forebrain
including the hypothalamus caused a decrease in the mitogenic proliferative
response of thymocytes and liver lymphocytes for 40 and 20%, respectively. The
ablation of the entire brain including the hypothalamus and pituitary resulted in
a 80% decrease of the proliferative response of thymocytes and in the full
suppression of proliferation of liver lymphocytes. The immune proliferative
response was restored by the LHRH administration either systemically to operated
fetuses (0.2 microg/fetus) or to the cell culture (10(-9) and 10(-7) M). It was
concluded that the central nervous system was important for maturation of the
immune system in rats during the prenatal period. In particular, neuroendocrine
system are likely to play a major role as LHRH treatment in vitro and in vivo
appeared to contribute to this regulation.
PMID- 10779588
TI - Inhibitory effects of human seminal plasma on an ELISA used to detect anti-sperm
antibodies: implications for the determination of sperm quality.
AB - The in vitro inhibitory effect of human seminal plasma on an ELISA used to detect
anti-sperm antibodies have been observed. The mean inhibition rate of seminal
plasma samples from 75 men was 61.5+/-23.1%. The inhibition rate of 29 samples
from normal sperm group was 71. 14+/-18.25%, while that of 46 samples from the
abnormal sperm group was 55.43+/-23.98%. The results show that human seminal
plasma from semen with high quality sperms possesses a high inhibitory rate to
anti-sperm antibody reactions, suggesting its efficiency for immunosuppression of
humoral immune reactions. Its possible implications are discussed.
PMID- 10779589
TI - A null mutation in HLA-G is not associated with preeclampsia or intrauterine
growth retardation.
AB - Modulation of the expression of genes of the major histocompatibility complex
(MHC) in tissues at the maternal-fetal interface almost certainly plays a role in
successful development of the semi-allogeneic fetus. While expression of the
classical class I genes (HLA-A, B, C) is low to non-existent at this site, the
non-classical molecule, HLA-G, is expressed uniquely in fetal cells at the
maternal-fetal interface. The recent demonstration that homozygotes for a
deletion mutation in exon 3 (1597DeltaC) of HLA-G do not express the full-length
HLA-G1 isoforms indicates a potential reduction in expression of this isoform in
heterozygotes. If the full-length isoform of HLA-G (i.e. HLA-G1) contributes to
proper invasion of maternal spiral arteries by extravillous cytotrophoblast, then
1597DeltaC heterozygotes could be at increased risk for disorders of trophoblast
invasion. Two populations, infants with intrauterine growth retardation (IUGR)
and infants of preeclamptic (PE) mothers, were genotyped for the 1597DeltaC
polymorphism. The frequency of 1597DeltaC in these samples was not significantly
different from healthy controls, suggesting that heterozygotes for this deletion
mutation are not at significantly increased risk for PE or IUGR (P = 0.727 and
0.803, respectively).
PMID- 10779590
TI - Tumor necrosis factor-alpha soluble receptor p55 (sTNFp55) and risk of
preeclampsia in Peruvian women.
AB - We conducted a large case-control study to assess the risk of preeclampsia with
elevated sTNFp55 concentrations (markers of excessive TNF-alpha release) in
Peruvian women. A total of 125 women with preeclampsia and 179 normotensive women
were included in a study conducted during the period, June 1997 through January
1998. Antepartum (third-trimester) plasma sTNFp55 was measured by enzyme linked
immunosorbent assay. Mean plasma sTNFp55 concentrations were 32.4% higher among
preeclampsia cases (920.1+/-30.4 pg/ml) as compared with controls (694.8+/-15.0
pg/ml, Student's t-test P<0.001). There was a strong linear increase in risk of
preeclampsia with increasing concentrations of sTNFp55 (linear trend P-value <0.
001). After adjusting for confounding factors, women in the highest quartile
experienced a 10-fold increased risk of preeclampsia as compared with women in
the lowest quartile (adjusted odds ratio, 10.3; 95% confidence interval, 4.1
25.9). Compared with women in the highest quartile, women in the second and third
quartiles experienced a 3-fold or greater increased risk of preeclampsia
(adjusted odds ratios were 3.1 and 3.8, respectively). Excessive TNF-alpha
release (as measured by the detection of the soluble receptor sTNFp55 in maternal
plasma collected before delivery) is increased in pregnancies complicated by
preeclampsia as compared with normotensive pregnancies. These findings are
consistent with most previous studies.
PMID- 10779591
TI - IL-18 in pregnancy; the elevation of IL-18 in maternal peripheral blood during
labour and complicated pregnancies.
AB - Serum interleukin-18 (IL-18) levels were measured in women in different
trimesters of pregnancy, in labour, puerperium and in various complicated
pregnancies. There was a significant elevation of IL-18 levels in pregnant sera
from the first trimester until the onset of labour. Once labour began, IL-18
levels increased further and remained until at least the third day of puerperium.
The high levels of IL-18 in sera were also observed in various complicated
pregnancies, such as premature rupture of membranes (PROM), acute fatty liver of
pregnancy and fetal growth restriction. IL-18 is likely to play a role in
pregnancy.
PMID- 10779592
TI - Characterization of domains of the phosphoriboprotein P0 of Plasmodium
falciparum.
AB - Antibodies against the amino-terminal domain of the Plasmodium falciparum P0
phosphoriboprotein were detected extensively in immune people living in malaria
endemic areas of India. It has been shown earlier that specific antibodies raised
against the PfP0N domain (17-61 amino acid) of the PfP0 protein inhibit P.
falciparum growth in vitro. To study the properties of the rest of the protein,
the remaining 61-316 amino acids on the carboxy-side of the PfP0 protein were
expressed as a glutathione-S-transferase fusion protein (PfP0C). Antibodies
raised against PfP0C identified the 38 kDa P0 protein on a parasite Western blot
analysis. An ELISA assay using both the PfP0N and PfP0C fusion proteins showed no
reactivity with malaria patient sera samples, but showed extensive reactions with
the immune sera. Antibodies against both the PfP0C and PfP0N domains were raised
in rabbits and different inbred strains of mice. T-cells from immunized mice
showed lymphoproliferation when presented with PfP0 protein domains. IgG from
both anti-PfP0N and anti-PfP0C sera inhibited the growth of P. falciparum in
vitro in a concentration dependent manner. The IgG did not show any significant
effect on the growth of intraerythrocytic stages, but specifically inhibited re
invasion of red cells. Merozoites and sexual stages showed surface reactivity to
both anti-PfP0N and anti-PfP0C antibodies in immunofluorescence assays. These
properties strongly indicate PfP0 as a possible target for invasion-blocking
antibodies.
PMID- 10779594
TI - Deletion of the parasite-specific insertions and mutation of the catalytic triad
in glutathione reductase from chloroquine-sensitive Plasmodium falciparum 3D7.
AB - The flavoenzyme glutathione reductase (GR; NADPH+glutathione disulphide+H(+)-
>NADP(+)+2 glutathione-SH) of Plasmodium falciparum is a promising drug target
against tropical malaria. As P. falciparum genes are assumed to be highly
polymorphic we have cloned and expressed the GR cDNA of the chloroquine-sensitive
strain 3D7. In comparison to the known GR of the chloroquine-resistant K1 strain
there are three base exchanges all of them leading to amino acid substitutions
(residues 281, 285 and 335). The catalytic efficiency k(cat)/K(m) of the 3D7
enzyme is 5-fold lower than for the K1 enzyme. In contrast, vis-a-vis the drugs
carmustine, methylene blue and fluorophenyliso-alloxazine the two enzyme species
exhibited identical inhibition kinetics. Two structural motifs which are specific
for P. falciparum GR were studied by mutational deletion analysis of 3D7 GR. Loop
126-138 appears to be important for folding and stability of the enzyme, whereas
the subdomain 318-350 was found to be involved in FAD-binding. The subdomain has
no major influence on the known functions of the catalytic triad Cys-40, Cys-45
and His-485'. Flavin absorption spectroscopy of inactive point mutants showed
that Cys-45 forms a thiolate charge transfer complex and Cys-40 is the
interchange thiol, which reduces glutathione disulphide. The mutant His-485-->Gln
had a normal K(m) for glutathione disulphide reduction but only 0.8% residual
catalytic activity when compared with wild-type GR, which confirms its function
as an acid/base catalyst. The parasite-specific domains in combination with the
reactive catalytic residues appear to be a suitable target matrix for inhibiting
GR in vivo.
PMID- 10779593
TI - Characterization of the heat-shock protein 60 chaperonin from Onchocerca
volvulus.
AB - Chaperonin 60 (cpn60) belongs to the group of ubiquitous molecular chaperones
that comprise the heat shock proteins, nucleoplasmins and chaperonins. Antibodies
to recombinant CPN60 from humans was used to screen a cDNA library of Onchocerca
volvulus and antigen-positive clones were selected. Sequencing of the DNA inserts
confirmed their identity as cpn60 transcripts. These are distinct from a cpn60
sequence recorded previously from O. volvulus (GenBank accession number Y09416)
that appears to be of endobacterial origin, rather than derived from the parasite
itself. The full-length sequence of the cDNA (designated Ov-cpn60) codes for a
protein of 64.3kDa (598 amino acid residues) and shares significant identity with
homologous gene products from Caenorhabditis elegans (72%), humans (69%), yeast
(53%) and Escherichia coli (50%). The endobacterial and parasite sequences are
41% conserved. Ov-CPN60 migrates with an apparent molecular mass of 65kDa on SDS
PAGE and is present in all life-cycle stages, as determined by immunoblotting
with rabbit antibodies raised against the recombinant protein. Immunogold
electron microscopy identified the protein within mitochondria, as expected, but
also in extra-mitochondrial sites, including inclusion bodies of the glandular
oesophagus (in infective larvae), the uterine wall, cytosol of developing
spermatids, and the hypodermis and cuticle. Endobacteria were also labelled,
indicating cross-reactivity between CPN60 from the parasite and its intracellular
symbiont. In human infections, serum antibodies to Ov-CPN60 were present in only
11% of cases from Ecuador, but in 81-89% of subjects in three separate foci from
West Africa. There was no relationship between antibody levels and age, sex, or
infection intensity, and no consistent association between the serological
response and immune status. An evaluation of antibody specificities in individual
sera revealed a mixture of parasite-specific and host crossreactive anti-CPN60
antibodies, the ratio of which varied amongst geographic areas. It is concluded
that antibody responses to Ov-CPN60 are unlikely to contribute either to host
protection or pathology in onchocerciasis.
PMID- 10779595
TI - Identification of mariner-like elements from the root-knot nematode Meloidogyne
spp.
AB - The Meloidogyne species are agriculturally important pests widespread in the
world. These polyphagous endoparasitic nematodes possess an astonishing ability
to bypass the plant resistance genes in few generations. However, the genes and
mechanisms involved in this molecular determinism are not yet known. Except
cytogenetic and cytotaxonomic studies, few data are available concerning their
genome. There is therefore an important need of molecular tools for genetic
investigation of their virulence character and other aspects of host-pathogen
interactions. In that respect, the presence of mariner-like-elements (MLEs) was
assessed in these endoparasitic nematodes by a polymerase chain reaction (PCR)
assay using degenerate primers designed from two conserved regions of the mariner
transposase open reading frame (ORF). Four Meloidogyne species of the five tested
revealed the presence of MLEs in their genome. Southern blot analysis indicated
that sequences hybridizing to the mariner transposase-like PCR clones occur at a
moderate to low copy number in the different Meloidogyne spp. genomes. The
phylogenetic analysis show that the Meloidogyne MLEs may form new subfamilies of
mariner. Moreover, five PCR clones were shown to possess a continuous ORF
suggesting the presence of putative transposase-like coding regions.
PMID- 10779596
TI - Succinate dehydrogenase in Plasmodium falciparum mitochondria: molecular
characterization of the SDHA and SDHB genes for the catalytic subunits, the
flavoprotein (Fp) and iron-sulfur (Ip) subunits.
AB - Mitochondria of malaria parasites generate a membrane potential through an
electron transport system that is a possible target of primaquine and a new anti
malarial drug, atovaquone. However, little information is available for
conclusive understanding of the respiratory chain in Plasmodium mitochondria. In
the present study, we cloned and characterized from Plasmodium falciparum the
genes for the catalytic subunits, SDHA for the flavoprotein (Fp) and SDHB for
iron-sulfur protein (Ip), of succinate-ubiquinone oxidoreductase (complex II),
which is a marker enzyme for mitochondria and links the TCA cycle and respiratory
chain directly. Each of the two genes contains a single open reading frame (ORF),
which are located on different chromosomes, 1860 nucleotides on chromosome 10 for
SDHA and 963 nucleotides on chromosome 12 for SDHB. The expression of these genes
in asynchronous erythrocytic stage cells was confirmed by observation of 3.3 and
2.4 kb transcripts from the SDHA and SDHB genes, respectively. The SDHA and SDHB
genes encode proteins of 620 (Fp) and 321 (Ip) amino acids with molecular masses
of 69.2 and 37.8 kDa, respectively. A mitochondrial presequence essential for the
import of mitochondrial proteins encoded by nuclear DNA, as well as almost all
the conserved amino acids indispensable for substrate binding and the catalytic
reaction were found in these peptides, indicating the functional importance of
this enzyme in the parasite. Interestingly, a P. falciparum-specific insertion
and a unicellular organism-specific deletion were found in the amino acid
sequence of Fp. This is the first report of the primary structure of the
protozoan succinate dehydrogenase.
PMID- 10779597
TI - Larvae-induced plasma membrane wounds and glycoprotein deposition are
insufficient for Trichinella spiralis invasion of epithelial cells.
AB - Trichinella spiralis L1 larvae infect susceptible hosts by invading epithelial
cells that line the small intestine. Invasion also occurs in vitro when larvae
are inoculated into cultures of epithelial cells from several different animal
species. To further investigate the mechanism of invasion, we studied the
interaction of larvae with the rat epithelial cell line IEC-6. Larvae did not
invade IEC-6 cells, but did cause the cells to take up parasite glycoproteins.
Glycoprotein bearing cells remained viable and were detectable in monolayers for
as long as 24 h, suggesting that the glycoproteins were not toxic for cells.
Immunofluorescence revealed that parasite glycoproteins localized in the nuclei,
mitochondria and cytoplasm and we found evidence for selection of certain
molecules between nuclear and cytoplasmic compartments. Using fluorescent
dextrans as fluid phase markers we found 17-38% of the cells in inoculated
monolayers were engorged with dextran and that dextran was free in the cytoplasm.
Increased dextran uptake was not lethal, required the presence of activated
larvae, and was often associated with uptake of parasite glycoproteins. These
observations suggest that larvae caused plasma membrane wounds. Our results
showed that neither delivery of glycoproteins nor mechanical wounding is
sufficient to allow entry of the parasite into resistant epithelial cells.
Because both invasion-resistant and susceptible epithelial cells undergo non
lethal wounding, we propose that larvae-induced injury to epithelial cells may
result in release of cell-specific mediators that signal larva to invade a
particular cell line or, alternatively, to ignore it.
PMID- 10779598
TI - Cloning, characterization and functional expression of a cyclophilin of Entamoeba
histolytica.
AB - Full-length Entamoeba histolytica cyclophilin gene (EhCyp) was isolated,
characterized and recombinantly expressed in bacterial cells. The deduced amino
acid sequence of EhCyp shows 60-70% identity with cyclophilins from other
organisms and has conserved the cyclophilin signature motifs and residues
involved in cyclosporin A binding. Upstream of the 501 bp open reading frame of
EhCyp, sequences resembling the putative consensus E. histolytica CE1, CE2 and
CE3 regulatory elements were found. Northern blot assays revealed a single
transcript of 0.63 kb. The transcription start was determined by primer extension
at position -13 relative to the initial ATG codon. Cyclosporin A binding and
peptidyl-proplyl cis-trans isomerase activities characteristic of cyclophilin
were detected in soluble extracts of E. histolytica trophozoites and in the
recombinant protein. In both cases, the isomerase activity was inhibited by
nanomolar concentrations of cyclosporin A. Treatment of cultured trophozoites
with cyclosporin A decreased their proliferation with a 50% inhibition value of 1
microg/ml and was lethal in doses over 50 microg/ml.
PMID- 10779599
TI - Plasmodium falciparum phosphoenolpyruvate carboxykinase is developmentally
regulated in gametocytes.
AB - Plasmodium species have the capacity to fix carbon dioxide during intracellular
development. This process contributes to the pool of free amino acids and
metabolites, which are the end products of glucose metabolism in the malaria
parasite. A gene encoding phosphoenolpyruvate carboxykinase (PEPCK), an enzyme
known to catalyze CO(2) fixation was identified in the genome of the human
parasite Plasmodium falciparum by DNA microarray analysis experiments and was
cloned and characterized. PfPEPCK is a 66.2 kDa, ATP-dependent enzyme which is
closely related to PEPCK from plants and yeast but markedly different from the
host enzyme human PEPCK. PfPEPCK transcript and active enzyme levels are
upregulated in the transmissible and zygote stages of parasite development
relative to the asexual blood stages. Elevated expression of PfPEPCK during the
extracellular zygote phase of P. falciparum development within the
microenvironment of the mosquito midgut may reflect a glucose-rare medium and
suggests a possible switch in carbohydrate metabolism to a gluconeogenesis
pathway.
PMID- 10779600
TI - Molecular cloning, sequencing and expression of a serine proteinase inhibitor
gene from Toxoplasma gondii.
AB - A cDNA clone from a Toxoplasma gondii tachyzoite cDNA library encoding a serine
proteinase inhibitor (serpin) was isolated. The 1376 bp cDNA sequence encodes a
294 amino acid protein with a putative signal peptide of 23 amino acids resulting
in a mature protein with a predicted mass of 30,190 Da and a pI of 4.86. This
protein has internal sequence similarity of residues 30-66, 114-150, 181-217 and
247-283 indicating a four-domain structure. The four domains exhibit high
identity to serine proteinase inhibitors belonging to the non-classical Kazal
type family. The gene is single copy in the tachyzoite haploid genome of RH
strain and was amplified by polymerase chain reaction (PCR). Several introns were
identified. The sequence encoding the mature protein was amplified by PCR, cloned
into the pQE30 vector and expressed in Escherichia coli. Specific antiserum
generated against the recombinant protein was used in immunoblot assay and two
bands of 38 and 42 kDa were detected in a whole parasite homogenate. The
recombinant protein showed trypsin-inhibitory activity, one of the two potential
specificities. We discuss the possible roles that T. gondii serpin(s) may play in
the survival of the tachyzoites in the host.
PMID- 10779601
TI - Targeted integration into a rRNA locus results in uniform and high level
expression of transgenes in Leishmania amastigotes.
AB - This report describes the construction of a DNA cassette for integration into a
genomic small sub-unit rRNA locus of Leishmania mexicana by homologous
recombination. Reporter genes encoding beta-galactosidase or green fluorescent
protein and the gene conferring hygromycin resistance were integrated downstream
of a RNA polymerase I-driven rRNA promoter. To ensure high expression of the
marker proteins in the intracellular, amastigote stage, transgene coding
sequences were followed by the intergenic region of the L. mexicana cysteine
proteinase B 2.8 gene which provides processing signals required for high level
expression in this life-cycle stage. Integration of the DNA cassette was also
efficiently obtained in L. major. We show that either beta-galactosidase or the
green fluorescent protein were abundantly, stably and uniformly expressed in
promastigotes and amastigotes of both Leishmania sp. The transgenic lines allow
parasite detection at high sensitivity in the tissues of infected mice and will
be useful to follow infections in macrophages in culture and in animal hosts.
PMID- 10779602
TI - Molecular cloning and characterization of an IgE-reactive protein from Anisakis
simplex: Ani s 1.
AB - Ingestion of the parasitic nematode Anisakis simplex in undercooked fish can
cause severe allergic reactions in some individuals. Using pooled human sera from
sensitized patients we have probed an expression library for A. simplex antigens.
One positive clone was found to encode a full length 21 kDa protein with strong
homology to nematode troponins. The recombinant protein was expressed as a GST
fusion protein and found by immunoblot analysis to react with sera from 20% of
allergic patients. The presence of functional EF-hand Ca(2+) binding motifs was
demonstrated by gel-shift analysis.
PMID- 10779603
TI - Structure and sequence variation of the trypanosome spliced leader transcript.
AB - We have assessed the potential of using the spliced leader (SL) or mini-exon gene
as a marker for molecular phylogenetic analysis of genus Trypanosoma. A total of
27 trypanosome sequences were compared, 18 of these being newly reported. In
contrast to genus Leishmania, we found the non-transcribed spacer region of the
SL locus in trypanosomes to be far too variable for informative comparison of all
but the most closely related species. At the other extreme, the short (39 nt) SL
exon was usually completely conserved and hence uninformative. The SL RNA showed
variation in both length (97-152 nt) and sequence among different trypanosome
species, with most variation occurring in stem-loop II. Consequently, this region
could not be aligned with confidence in multiple sequence alignment, severely
reducing the number of phylogenetically informative nucleotide positions. In
computer simulation, most of the SL RNAs readily folded into the 3 stem-loop
secondary structure predicted previously, but again stem-loop II was highly
variable. No obvious correlation could be seen between the length of this stem
loop and trypanosome biology. We conclude that the SL repeat is not an
informative phylogenetic marker for long range evolutionary studies of genus
Trypanosoma.
PMID- 10779604
TI - Molecular cloning of a putative alpha3-fucosyltransferase from Schistosoma
mansoni.
AB - Alpha 3-fucosylation of protein or lipid substrates is an important component of
the host/parasite interactions during schistosomiasis. In this process, alpha3
fucosyltransferases (alpha3-FucTs) are considered as key enzymes ensuring both
parasite survival and adaptation in their (in)vertebrate hosts. In this paper, we
report the molecular cloning of a putative alpha3-FucT from Schistosoma mansoni
that we termed SmFucTA. The full-length SmFucTA encodes a typical transmembrane
type II protein with a short cytoplasmic domain, a transmembrane segment and a
long C-terminal catalytic domain. In this region, the GDP-fucose binding site is
well conserved whereas the putative acceptor site displays sequence divergence
compared to the corresponding region from vertebrate and invertebrate alpha3
FucTs. Southern blot analysis suggested that SmFucTA is present as several copies
or has highly related counterparts in the S. mansoni genome. Northern blot
revealed a single SmFucTA transcript at 2 kb in adult worms. Affinity purified
antibodies directed against recombinant SmFucTA identified a 50 kDa native
protein that localizes to the subtegumental and parenchymal regions of adult
worms.
PMID- 10779606
TI - Cloning and characterization of beta-tubulin genes from Echinococcus
multilocularis.
PMID- 10779605
TI - Identification and predicted structure of a leucine-rich repeat motif shared by
Leishmania major proteophosphoglycan and Parasite Surface Antigen 2.
PMID- 10779607
TI - Experimental DNA melting behavior of the three major Schistosoma species.
PMID- 10779608
TI - Molecular characterisation of a Theileria lestoquardi gene encoding a candidate
sporozoite vaccine antigen.
PMID- 10779609
TI - Analysis of antisense and double stranded RNA downregulation of A2 protein
expression in Leishmania donovani.
PMID- 10779610
TI - Trafficking of cysteine proteinase to Leishmania lysosomes: lack of involvement
of glycosylation.
PMID- 10779613
TI - Corrigendum to "Intra and inter-specific microsatellite variation in the
leishmania subgenus Viannia".
PMID- 10779614
TI - Microbial reductive dehalogenation of polychlorinated biphenyls.
AB - Under anaerobic conditions, microbial reductive dechlorination of polychlorinated
biphenyls (PCBs) occurs in soils and aquatic sediments. In contrast to
dechlorination of supplemented single congeners for which frequently ortho
dechlorination has been observed, reductive dechlorination mainly attacks meta
and/or para chlorines of PCB mixtures in contaminated sediments, although in a
few instances ortho dechlorination of PCBs has been observed. Different
microorganisms appear to be responsible for different dechlorination activities
and the occurrence of various dehalogenation routes. No axenic cultures of an
anaerobic microorganism have been obtained so far. Most probable number
determinations indicate that the addition of PCB congeners, as potential electron
acceptors, stimulates the growth of PCB-dechlorinating microorganisms. A few PCB
dechlorinating enrichment cultures have been obtained and partially
characterized. Temperature, pH, availability of naturally occurring or of
supplemented carbon sources, and the presence or absence of H(2) or other
electron donors and competing electron acceptors influence the dechlorination
rate, extent and route of PCB dechlorination. We conclude from the sum of the
experimental data that these factors influence apparently the composition of the
active microbial community and thus the routes, the rates and the extent of the
dehalogenation. The observed effects are due to the specificity of the
dehalogenating bacteria which become active as well as changing interactions
between the dehalogenating and non-dehalogenating bacteria. Important
interactions include the induced changes in the formation and utilization of H(2)
by non-dechlorinating and dechlorinating bacteria, competition for substrates and
other electron donors and acceptors, and changes in the formation of acidic
fermentation products by heterotrophic and autotrophic acidogenic bacteria
leading to changes in the pH of the sediments.
PMID- 10779615
TI - Hexadecane mineralization and denitrification in two diesel fuel-contaminated
soils.
AB - The effect of nitrate, ammonium and urea on the mineralization of
[(14)C]hexadecane (C(16)H(34)) and on denitrification was evaluated in two soils
contaminated with diesel fuel. In soil A, addition of N fertilizers did not
stimulate or inhibit background hexadecane mineralization (4.3 mg C(16)H(34) kg(
1) day(-1)). In soil B, only NaNO(3) stimulated hexadecane mineralization (0.91
mg C(16)H(34) kg(-1) day(-1)) compared to soil not supplemented with any nitrogen
nutrient (0.17 mg C(16)H(34) kg(-1) day(-1)). Hexadecane mineralization was not
stimulated in this soil by NH(4)NO(3) (0.13 mg C(16)H(34) kg(-1) day(-1)), but
the addition of NH(4)Cl or urea suppressed hexadecane mineralization (0.015 mg
C(16)H(34) kg(-1) day(-1)). Addition of 2 kPa C(2)H(2) did not inhibit the
mineralization process in either soil. Denitrification occurred in both soils
studied when supplemented with NaNO(3) and NH(4)NO(3), but was not detected with
other N sources. Denitrification started after a longer lag in soil A (10 days)
than in soil B (4 days). In soil A microcosms supplemented with NaNO(3) or
NH(4)NO(3), rates of denitrification were 20.6 and 13.6 mg NO(3)(-) kg(-1) day(
1), respectively, and in soil B, they were 18.5 and 12.5 mg NO(3)(-) kg(-1) day(
1), respectively. We conclude that denitrification may lead to a substantial loss
of nitrate, making it unavailable to the mineralizing bacterial population.
Nitrous oxide was an important end-product accounting for 30-100% of total
denitrification. These results indicate the need for preliminary treatability
studies before implementing full-scale treatment processes incorporating
commercial fertilizers.
PMID- 10779616
TI - Comparison of pure cultures and natural assemblages of planktonic photosynthetic
sulfur bacteria by low molecular mass RNA fingerprinting.
AB - Pure cultures of phototrophic sulfur bacteria were compared to natural
populations that bloom in karstic lakes by electrophoretic analysis of low
molecular mass RNA molecules (lmwRNA) and microscopy. Similarities between
dominant community members, field isolates and reference strains were established
by comparing the lmwRNA band patterns through dendrograms produced with Euclidean
distances and the average linkage clustering method, by a single, quick, one-step
method. The fingerprinting analysis had three objectives: (i) to compare
microbial assemblages from different geographical locations, (ii) to compare
those organisms which grow in pure culture to those forming planktonic blooms and
(iii) to give a preliminary view of the identity of the predominant community
members. The lmwRNA analysis yielded a number of clusters consistent with the
microscopic observations and allowed rapid comparison of the microbial
communities without the need to isolate their individual components. The
fingerprints of natural communities were different from most of the laboratory
strains tested. Purple sulfur bacteria responsible for the blooms analyzed in
karstic lakes were more closely related to the Thiocystis group than to the
classical strains extensively studied in the laboratory.
PMID- 10779617
TI - Effect of 2-bromo-ethane sulfonate, molybdate and chloroform on acetate
consumption by methanogenic and sulfate-reducing populations in freshwater
sediment.
AB - The relative importance of methanogenesis and sulfate reduction in freshwater
sediment supplemented with acetate was investigated. Addition of acetate
stimulated both methane formation and sulfate reduction, indicating that an
active aceticlastic population of methanogens and sulfate reducers was present in
the sediment. Sulfate reducers were most important in the consumption of acetate.
However, when sulfate reducers were inhibited, acetate was metabolised at a
similar rate by methanogens. Acetate, propionate and valerate accumulated only
when both processes were inhibited by the combined addition of 2-bromo-ethane
sulfonate and molybdate. The relative amounts of acetate, propionate and valerate
were 93, 6 and 1 mol%, respectively. These results demonstrate the role of
acetate as a key intermediate in the terminal step of organic matter
mineralisation in the sediment. Addition of chloroform inhibited both
methanogenesis and sulfate reduction. We studied the inhibitory effect of CHCl(3)
on homoacetogenic bacteria, sulfate-reducing bacteria and methanogens. The
results showed that inhibition by CHCl(3) correlates with microorganisms, which
operate the acetyl-CoA cleavage pathway. We propose that chloroform can be used
to elucidate the role of different metabolic types of sulfate reducers to sulfate
reduction in natural environments.
PMID- 10779618
TI - Effect of Cd-containing wood ash on the microflora of coniferous forest humus.
AB - The use of wood ash in forestry has been questioned because the cadmium (Cd)
concentration of ash, which varies between 1 and 20 mg kg(-1) ash, exceeds the
level allowed for fertilizers (3 mg kg(-1)) used in agriculture. To investigate
the combined and separated effects of Cd and ash on the forest humus microflora,
pumice or wood ash, spiked with a water-soluble (CdCl(2)) or -insoluble (CdO)
form of Cd at three levels (0, 400 and 1000 mg kg(-1)), were applied at a
fertilization level of 5000 kg ha(-1) in a laboratory microcosm study. The trial
consisted of 60 microcosms (five replications per treatment), which were
incubated in darkness at +20 degrees C and a constant relative air humidity of
60%. After two months the humus in the microcosms was sampled. Analyses of CO(2)
evolution to measure the overall microbial activity and of phospholipid fatty
acid (PLFA) pattern to measure microbial community structure were performed. The
substrate-use patterns of Biolog EcoPlates were analyzed as a measure of
bacterial functionality. Finally the bacterial (3)H-thymidine incorporation in
the presence of different concentrations of Cd and the number of colony forming
units (cfu) of bacteria on nutrient agar in the presence of 0, 5 and 20 mg Cd l(
1) agar were applied to measure Cd tolerance. The use of pumice (pH of humus
under the pumice 4.0) did not induce any changes in the above variables compared
to two untreated microcosms (humus pH 3.9). Pumice was therefore used to
distribute the Cd evenly over the humus surface in order to estimate the possible
effect of Cd without ash (pH of humus under the ash 7.0). The application of ash
increased the microbial activity, changed the PLFA and substrate-use patterns and
increased cfu compared to the humus under pumice. The form and level of Cd in the
ash had no further effect on this result. In the humus under pumice the level,
but not the form of Cd decreased the microbial activity and changed the PLFA
pattern compared to the unspiked pumice. None of the treatments induced bacterial
tolerance to Cd. Ash thus protected the humus microflora from the harmful effects
of Cd.
PMID- 10779619
TI - Characterization of 3-chlorobenzoate degrading aerobic bacteria isolated under
various environmental conditions.
AB - The rates of bacterial growth in nature are often restricted by low
concentrations of oxygen or carbon substrates. In the present study the metabolic
properties of 24 isolates that had been isolated using various concentrations of
3-chlorobenzoate, benzoate and oxygen as well as using continuous culture at high
and low growth rates were determined to investigate the effects of these
parameters on the metabolism of monoaromatic compounds. Bacteria were enriched
from different sampling sites and subsequently isolated. In batch culture this
was done both under low oxygen (2% O(2)) and air-saturated concentrations.
Chemostat enrichments were performed under either oxygen or 3-chlorobenzoate
limiting conditions. Bacteria metabolizing aromatics with gentisate or
protocatechuate as intermediates (gp bacteria) as well as bacteria metabolizing
aromatic compounds via catechols (cat bacteria) were isolated from batch cultures
when either benzoate or 3CBA were used as C sources, regardless of the enrichment
conditions applied. In contrast, enrichments performed in chemostats at low
dilution rates resulted in gp-type organisms only, whereas at high dilution rates
cat-type organisms were enriched, irrespective of the oxygen and 3-chlorobenzoate
concentration used during enrichment. It is noteworthy that the gp-type of
bacteria possessed relatively low u(max) values on 3CBA and benzoate along with
relatively high substrate and oxygen affinities for these compounds. This is in
contrast with cat-type of bacteria, which seemed to be characterized by high
maximum specific growth rates on the aromatic substrates and relatively high
apparent half saturation constants. In contrast, bacteria degrading
chlorobenzoate via gentisate or protocatechuate may possibly be better adapted to
conditions leading to growth at reduced rates such as low oxygen and low
substrate concentrations.
PMID- 10779620
TI - Reduction in denitrification activity in field soils exposed to long term
contamination by 2,4,6-trinitrotoluene (TNT).
AB - Terrestrial sites contaminated with 2,4,6-trinitrotoluene (TNT) are a widespread
and persistent problem and often contain non-vegetated areas with TNT
concentrations well in excess of 1000 mg kg(-1). In this study, we examined the
effect of TNT on denitrification activity in field soils, and compared the
sensitivity of denitrifying enzymes to TNT. DNA probes assessed the prevalence of
nirS, nirK and nosZ (encoding cd(1) or copper nitrite reductase and nitrous oxide
reductase, respectively), denitrifying genotypes in the culturable and total
microbial community. The nitrate (NaR), nitrite (NiR) and nitrous oxide (N(2)OR)
reductase activities in field soil and in isolates were assessed by gas
chromatography. The relative occurrence of the nirK, nirS or nosZ genotypes
increased in the cultured community and in total uncultured community DNA as
nitroaromatic concentrations increased. However, denitrifying activity decreased
in response to increasing TNT concentrations, with an IC(50) for NaR+NiR+nitric
oxide reductase (NOR) of 400 mg TNT kg(-1) soil and for N(2)OR of 26 mg TNT kg(
1) soil. The denitrifying activity of four soil isolates also decreased in
response to TNT, with N(2)OR activity being three times more sensitive to TNT
than NaR+NiR+NOR activity. Interestingly, there were 118 times more nirK isolates
than nirS isolates in uncontaminated soil but only 1.5 times more in soil
containing 17400 mg kg(-1) TNT. The results from this study indicated that TNT
reduced denitrification activity in field soils, and N(2)OR was much more
sensitive to TNT than NaR+NiR+NOR.
PMID- 10779621
TI - Characterization of bacterial strains able to grow on high molecular mass
residues from crude oil processing.
AB - Oil residues containing high molecular mass hydrocarbons, rich in polyaromatic
compounds, are frequent end-products of crude oil processing and are poorly
biodegradable. Their disposal poses an environmental problem. Through batch
enrichments from contaminated soils we have isolated and characterized seven
bacterial strains that can use a residue from crude oil processing as a source of
carbon and energy. The residue was a complex mixture of high molecular mass
compounds, including saturated, aromatic and polycyclic aromatic hydrocarbons
(PAHs). Analysis of the metabolic profiles of the strains isolated showed that
they could all metabolize long-chain-length alkanes efficiently, but not PAHs.
Strains degrading naphthalene, a simple PAH, did exist in the soil inocula used,
but could be isolated only when enrichments were performed using pure naphthalene
as the sole carbon source. All strains tested emulsified the oil residue and
their ability to produce surfactants was studied.
PMID- 10779622
TI - PCR typing of tetracycline resistance determinants (Tet A-E) in Salmonella
enterica serotype Hadar and in the microbial community of activated sludges from
hospital and urban wastewater treatment facilities in Belgium.
AB - The distribution of tetracycline resistance determinants Tet A-E was studied by
PCR in 40 tetracycline-resistant Salmonella enterica serotype Hadar (S. hadar)
isolates collected from human patients in 1996 and 1997, as well as in the
microbial community originating from activated sludges of hospital and urban
wastewater treatment facilities. A fast DNA extraction and purification method
from activated sludges was used to provide amplifiable DNA. The method is based
on the direct lysis of bacteria improved by bead-beating followed by DNA
purification on polyvinylpolypyrrolidone spin columns to remove PCR inhibitors.
The purified DNAs from salmonellae and activated sludges were characterized for
the presence of tetracycline determinants with specific primer pairs designed on
the basis of published sequences. The Tet A determinant was present in all
clinical isolates and DNAs extracted from the bacterial community of the selected
activated sludges. The Tet C determinant was identified in only one of the 40
clinical isolates and in six of the seven environmental samples. No signal was
detected for Tet B, D and E determinants. This study revealed a high and stable
prevalence of the Tet A determinant in both salmonellae clinical isolates and the
microbial community of activated sludges from hospital and urban wastewater
treatment facilities over a 2-year period.
PMID- 10779623
TI - Green tea polyphenols and tannic acid act as potent inhibitors of phorbol ester
induced nitric oxide generation in rat hepatocytes independent of their
antioxidant properties.
AB - The deleterious effects of excessive release of nitric oxide (NO) have been
implicated in the tissue damage and inflammation. In this study, the effect of
various flavonoids and other oxidant scavenging chemical agents have been studied
for their ability to inhibit 12-O-tetradecanoyl phorbol 13-acetate (TPA)-induced
NO generation in rat hepatocyte. Hepatocytes activated with TPA (25-200 nM)
released NO in a concentration- and time-dependent manner. Green tea polyphenols
(GTP) and tannic acid (TA) were most effective in inhibiting TPA-induced NO
generation (90%). These agents were also effective in inhibiting NO formation
when added 2 h following TPA addition. The other oxidant scavengers, such as L
histidine, sodium azide, vitamin E and sodium benzoate, were not found to be
effective even up to 1.0 mM concentration. These results suggest that TA and GTP
are potent inhibitors of NOS activity and the inhibition of TPA-induced NO
generation by these polyphenols is independent of their antioxidant activity. It
is tempting to speculate that these agents could be utilized in the
pharmacological manipulations of NO-dependent pathophysiological responses.
PMID- 10779624
TI - Plasma concentrations of VEGF and bFGF in patients with gastric carcinoma.
AB - We examined plasma levels of vascular endothelial growth factor (VEGF) and basic
fibroblast growth factor (bFGF) in 54 patients with gastric carcinoma.
Postoperative survival was significantly poorer in patients with plasma VEGF
levels more than 10.0 pg/ml at the time of surgery. By an univariate analysis of
the factors affecting survival, serosal invasion, lymph node metastasis,
peritoneal dissemination, lymphatic vessel invasion, curability, and VEGF
proteins were significant. By a multivariate analysis only VEGF levels and
curability remained significant. Patients with recurrent disease, including liver
metastasis, had significantly higher plasma VEGF concentrations than those with
resectable primary tumors. VEGF, not bFGF, may serve as an independent
prognosticator and a sensitive indicator for liver recurrence in patients with
gastric carcinoma.
PMID- 10779625
TI - Effects of neoplastic transformation and teniposide (VM26) on protein kinase C
isoform expression in rodent fibroblasts.
AB - This study examined changes in protein kinase C (PKC) isoforms in rodent
fibroblasts (rat F111 and mouse NIH3T3), transformed by the polyoma virus middle
T antigen (mT) and undergoing apoptosis in response to teniposide (VM26). The mT
transformed cells up-regulated PKC delta and down-regulated both PKC epsilon and
PKC lambda expression, and were more sensitive to the drug than their non
transformed counterparts. The drug treatment further lowered the expression of
PKC epsilon, triggered nuclear translocation of PKC delta and its site-specific
proteolysis, consistent with the notion that changes in specific PKC isoforms
play a role not only in the neoplastic transformation of fibroblasts, but also in
their apoptotic response.
PMID- 10779626
TI - Development of a novel (32)P-postlabeling method for the analysis of 3'-azido-3'
deoxythymidine.
AB - 3'-Azido-3'-deoxythymidine (AZT) was the first anti-retroviral nucleoside analog
to be used in the treatment and prevention of acquired immunodeficiency syndrome
(AIDS). A novel (32)P-postlabeling assay, based upon thymidine kinase (TK)
instead of the conventional T(4) polynucleotide kinase, has been developed for
the detection of the levels of AZT incorporated into DNA. After enzymatic
digestion of DNA to deoxynucleoside 3'-monophosphates, AZT was isolated by ethyl
acetate extraction. The ethyl acetate was evaporated and the AZT was postlabeled
by 5'-phosphorylation with [gamma-(32)P]ATP and TK. AZT was detected at a level
of 51.5+/-6.3 (mean+/-SD; n=4) AZT molecules/10(5) nucleotides following in vitro
incorporation of the drug into high-molecular-weight rat-liver DNA. The (32)P
postlabeling method was further validated by the detection of AZT in lung and
liver DNA from neonatal mice treated with AZT. The levels of AZT in lung and
liver DNA were proportional to the dose, with the levels in lung DNA being two
fold higher than those for liver DNA. The limit of detection for the assay was 8
AZT molecules/10(7) nucleotides using 10 microg of DNA.
PMID- 10779627
TI - Potentiation of benzo[a]pyrene-induced pulmonary and forestomach tumorigenesis in
mice by D,L-buthionine-S,R-sulfoximine-mediated tissue glutathione depletion.
AB - In vitro studies have suggested that the glutathione (GSH) S-transferase (GST)
catalyzed GSH conjugation is an important mechanism for the detoxification of (+)
anti-7,8-dihydroxy-9, 10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene [(+)-anti-BPDE],
which is the activated form of the widespread environmental pollutant
benzo[a]pyrene (BP). However, in vivo experimental evidence for the importance of
GSH/GST system in defense against carcinogenic effects of BP is lacking. We
hypothesized that if GSH/GST were to play an important role in the detoxification
of (+)-anti-BPDE, the tumorigenic activity of BP would be increased by depleting
the levels of GSH, which is the required nucleophilic substrate for GST-catalyzed
conjugation reactions. In the present study, we have tested the above hypothesis
by determining the effect of D, L-buthionine-S,R-sulfoximine (BSO)-mediated
tissue GSH depletion on BP-induced tumorigenesis of the lung and forestomach in
female A/J mice. Treatment of mice with three i.p. injections of 2.5 mmol BSO/kg
(12 h apart) plus 20 mM BSO in drinking water, resulted in a statistically
significant reduction in hepatic, pulmonary and forestomach GSH levels. At the
same time, BSO-administration caused a statistically significant increase in BP
induced pulmonary and forestomach tumor multiplicity. To the best of our
knowledge, the present study is the first report that provides in vivo
experimental evidence for the importance of GSH/GST system in cellular protection
against carcinogenic effects of BP.
PMID- 10779628
TI - Expression of cyclin E and p27(KIP1) in cervical carcinoma.
AB - Carcinogenesis is characterized by deregulation of the cell cycle. Although p53
is still the most important cell-cycle regulator in human malignancies, there is
an increased body of evidence indicating that the aberrant expression of cyclins
and cyclin-dependent kinase (CDK) inhibitors is considered as one of the most
important events in malignant transformation of various human cancers. Among
these cell-cycle regulators, the role of cyclin E and p27(KIP1) in the
tumorigenesis of the uterine cervix has been poorly defined. Using formalin
fixed, paraffin-embedded cervical tissues, we investigated the expression of
cyclin E and p27(KIP1) by immunohistochemistry, and human papillomavirus (HPV)
types 16 and 18 by nested polymerase chain reaction (PCR) in 22 control cases, 23
cases with cervical intraepithelial neoplasia (CIN), and 45 patients with
invasive cervical carcinoma (ICC). The p27 index (P27I) was significantly lower
in patients with ICC and CIN compared to those with a normal cervix. Patients
with either invasive cancer or CIN were found to have a significantly higher
cyclin E index (CEI) than the controls (P<0.05). Our results were consistent with
the concept that the deregulated expression of cyclin E and p27(KIP1) may play an
important role in the neoplastic transformation of cervical carcinoma.
PMID- 10779629
TI - Preferential cytotoxicity of caffeic acid phenethyl ester analogues on oral
cancer cells.
AB - As part of our previous search for new compounds with improved biological
activities including antibiotic, antiviral, anti-inflammatory, and tumor growth
inhibition activities, we synthesized some caffeic acid phenethyl ester (CAPE)
like compounds from commercially available caffeic acid. Nine chemicals were
tested by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay
on the growth of buccal mucosal fibroblast (BF), oral submucosus fibroblast
(OSF), neck metastasis of Gingiva carcinoma (GNM), and tongue squamous cell
carcinoma (TSCCa) cells. CAPE and its ethyl analogue show significant
cytotoxicity on OSF, GNM, and TSCCa cells, but not on BF cells. The results
suggest that CAPE-like compounds may be potential chemotherapy agents against
oral cancer.
PMID- 10779630
TI - Absence of hSNF5/INI1 mutation in human lung cancer.
AB - Frequent occurrence of chromosome 22q deletions in lung cancer indicates the
presence of a tumor suppressor gene on this chromosome arm. The hSNF5/INI1 gene
at chromosome 22q11.2 has recently been shown to act as a tumor suppressor in
rhabdoid tumors. To investigate whether the hSNF5/INI1 gene located on chromosome
22q is involved in lung carcinogenesis, mutation analysis of the hSNF5/INI1 gene
was performed using 50 lung cancer cell lines. No mutations causing amino acid
substitutions or frameshifts were found by PCR-SSCP analysis of the entire coding
region. The results indicated that the hSNF5/INI1 gene is not inactivated in lung
cancers and suggested the presence of another tumor suppressor gene on chromosome
22q. Thus, further studies are necessary to identify the target lung tumor
suppressor gene(s) on chromosome 22q.
PMID- 10779631
TI - Tumor formation suppressed in gammadeltaT knock-out mice.
AB - Tumor formation was examined in mice in which the beta-chain gene of alphabetaT
was knocked out (alphabetaT-KO mice) or the delta-chain gene of gammadeltaT was
knocked out (gammadeltaT-KO mice). Development of Hepa 1-6 cell hepatoma was
observed in six of six alphabetaT-KO mice, in four of six wild-type mice, and in
only one of six gammadeltaT-KO mice. These results imply that gammadeltaT cells
play a role in suppression of killer cell activity in tumor-bearing mice.
PMID- 10779632
TI - Loss of IGF-II imprinting in endometrial tumors: overexpression in
carcinosarcoma.
AB - The genomic imprinting of the maternal allele defines the monoallelic expression
of the IGF-II gene in most human tissues. The loss of imprinting (LOI) leading to
biallelic overexpression of IGF-II has been reported in several human
malignancies, including uterine leiomyosarcoma. To ascertain if LOI occurs in
endometrial malignancies, the allelic expression of the IGF-II gene was examined
in samples of normal human endometrium (n=22) and endometrial tumors (n=12) by
assessing the ApaI polymorphism in cDNA segments amplified by RT-PCR. The
biallelic overexpression of IGF-II mRNA, involving activation of all four (P1-P4)
promoters, was detected in one normal endometrium and in one endometrial
carcinosarcoma. Low level biallelic expression of IGF-II was also detected in two
samples of hormone-unresponsive/Type II endometrial carcinomas. The level of IGF
I mRNA in these four samples was low. The IGF-IR mRNA was overexpressed in all
endometrial cancers including the carcinosarcoma sample, but not in normal
endometrium. These data suggest that LOI associated with overexpression of IGF-II
and concomitant overexpression of IGF-IR may play a role in the rare
carcinosarcoma of the endometrium.
PMID- 10779633
TI - Effects of tetracyclines on angiogenesis in vitro.
AB - Most tumors kill their hosts by the process of metastasis rather than by local
growth of the primary mass. A significant factor contributing to the distant
invasion of cancer cells is the ability of tumors to produce large numbers of new
blood vessels in their midst, known as angiogenesis. This both provides access to
nourishment for the primary cancer and enables the cells to escape from the tumor
and enter the bloodstream. We have been examining agents that appear to inhibit
metastasis and, in particular, angiogenesis. We now report on the ability of the
synthetic tetracycline, doxycycline, and the chemically-modified tetracycline,
COL-3, to inhibit angiogenesis in a quantitative in vitro assay of angiogenesis,
using human umbilical vascular endothelial cells (HUVECs) attached to
microcarrier beads.
PMID- 10779634
TI - Induction of KAI-1 expression in metastatic cancer cells by phorbol esters.
AB - KAI-1 is a tumor suppressor gene whose down-regulation has been shown to be
associated with the development of metastases of cancer cells. Here, we
demonstrated that KAI-1 expression was induced by activating protein kinase C
even in metastatic prostate cancer cell lines in which its expression was
significantly down-regulated. KAI-1 expression was enhanced in a dose-dependent
manner by PMA, and its induction is at least in part due to transcriptional
activation. Pretreatment with calphostin C abrogated its induction by PMA. Our
findings may provide useful information for developing a novel drug capable of
inducing KAI-1 expression and thereby inhibiting metastasis.
PMID- 10779635
TI - Salvia miltiorrhiza inhibits cell growth and induces apoptosis in human hepatoma
HepG(2) cells.
AB - Salvia miltiorrhiza (SM) is a traditional Chinese herbal medicine, commonly used
to treat liver diseases in China for centuries. Several earlier studies have
indicated that SM exhibits anti-tumor properties, but its mechanism remains to be
elucidated. In this study, we evaluated the molecular mechanism of SM in a human
hepatoma cell line, HepG(2). Our results show that SM exerted clear cytotoxic
effects, and strongly inhibited the proliferation of HepG(2) cells. It was also
observed that SM treatment caused apoptotic cell death as evaluated by: (a),
morphological changes by using acridine orange/ethidium bromide staining; (b),
DNA fragmentation by TdT-mediated dUTP nick end labeling (TUNEL); and (c), sub
G(1) cell analysis. Furthermore, depletion of intracellular glutathione (GSH) and
reduction of mitochondrial membrane potential were found to be involved in the
initiation of apoptosis by SM.
PMID- 10779636
TI - Expression of mediated P-glycoprotein multidrug resistance related to Tc-99m MIBI
scintimammography results.
AB - We prospectively studied a total of 24 patients with breast cancer to evaluate
the relationship between the degree of accumulation of technetium-99m sestamibi
(Tc-99m MIBI) and p-glycoprotein (Pgp) expression in tumor tissues. All 24
patients underwent Tc-99m MIBI scintimammography before surgery or biopsy.
Immunohistochemical studies were performed on multiple non-consecutive sections
of the same tumor using a Pgp specific monoclonal antibody, JSB-1. Planar images
were started 10 min after injection of Tc-99m MIBI. Tumor to background (T/B)
ratios calculated from the planar images were correlated with Pgp expression as
determined by immunohistochemical studies. The T/B ratios were significantly
lower for tumors in eight patients with positive Pgp expression (Group 1) than in
16 patients with negative expression (Group 2) (1.40+/-0.11 and 2.76+/-0.60, P<0.
05). Our data confirmed that Tc-99m MIBI scintimammography is useful for
determination of the presence of multidrug resistance due to Pgp expression in
patients with breast cancer.
PMID- 10779637
TI - Morphological change, loss of deltapsi(m) and activation of caspases upon
apoptosis of colorectal adenocarcinoma induced by 5-FU.
AB - Apoptosis is clearly distinguished from necrosis, morphologically and chemically.
Morphologically, apoptosis is characterized by a condensed nucleus and the
disappearance of microvilli without disruption of the cytoplasm. In this report,
we demonstrate that 5-fluorouracil (5-FU)-induced early apoptotic cells are
characterized by (i) ultracondensed mitochondria, (ii) no change in the
microvilli or nucleus, (iii) a high mitochondrial transmembrane potential
(Deltapsi(m)), and (iv) being annexin V(negative). The early apoptotic cells also
show the active forms of caspase 8 and caspase 9. They rapidly lose Deltapsi(m)
after further incubation. Therefore, we conclude that the ultracondensation of
mitochondria precedes the loss of Deltapsi(m) and the exposure of
phosphatidylserine to the outer leaflet of the cell membrane.
PMID- 10779638
TI - Prevention of cross-contamination during sampling procedure in molecular
detection for cancer micrometastasis.
AB - Reverse transcriptase-polymerase chain reaction (RT-PCR) techniques have been
widely employed as an ultra-sensitive method for detection of micrometastases in
patients with various types of malignancies. Messenger RNA of a specific marker
gene is a target for RT-PCR amplification to examine the presence of
micrometastases in body fluids or tissues obtained from human. We developed the
RT-PCR assay specific for rat beta-actin mRNA, which cannot detect human
counterpart and assessed how much contamination of rat tissues can influence the
result of RT-PCR assay and how to avoid the influence of the contamination in RT
PCR assay.
PMID- 10779639
TI - Polymorphisms of glutathione S-transferase genes (GSTM1, GSTP1 and GSTT1) and
breast cancer susceptibility.
AB - The glutathione S-transferase (GST) family of enzymes function in the body to
detoxify carcinogenic compounds. Several genes that code for these enzymes are
polymorphic, with particular genotypes previously shown to confer an increased
cancer risk. In this study, we investigated the role of three GST genes (GSTM1,
GSTP1 and GSTT1) in the development of sporadic breast cancer. Genotypes were
determined in 129 breast cancer affected and 129 age and sex matched control
individuals. Results did not support an involvement of these specific GST gene
polymorphisms, either independently or in combination, in susceptibility to
sporadic breast cancer in the tested Australian Caucasian population.
PMID- 10779640
TI - Nitrotyrosine in esophageal squamous cell carcinoma and relevance to p53
expression.
AB - We have examined the expression of nitrotyrosine, a marker of peroxynitrite
formation, in 55 esophageal cancers by immunohistochemistry. Nitrotyrosine was
detected in 21 of 55 (38.2%) esophageal cancers. Comparison of nitrotyrosine
expression and the pathological findings showed that there was a significant
association between the expression of nitrotyrosine and each of the depth of
tumor invasion (P<0.01), occurrence of metastasis (P<0.05), pathological stage
(P<0.01), smoking status (P<0.05) and alcohol intake (P<0.05). The survival rate
of patients with nitrotyrosine-negative cancer was significantly higher than that
of patients with nitrotyrosine-positive cancer (log-rank test, P<0.01). p53 was
detected in 29 of 55 (52.7%) esophageal cancers, however, p53 expression did not
correlate with nitrotyrosine expression. In conclusion, nitrotyrosine, a product
of nitrogen species, is expressed in esophageal squamous cell carcinoma, which
suggests that exogenous risk factors, such as tobacco and alcohol, through NO,
are associated with carcinogenesis and progression of esophageal squamous cell
carcinoma.
PMID- 10779641
TI - Loss of p16 and p27 is associated with progression of human gastric cancer.
AB - We performed the immunohistochemical staining for six G1 check point cell cycle
proteins to study their expression patterns and roles in the gastric
carcinogenesis. We studied 76 cases of paraffin blocks that included the sections
of 18 tubular adenomas (TA), 38 early gastric carcinomas (EGC) (20 cases of
mucosal type, nine cases of submucosal type with no nodal metastasis, nine cases
of submucosal type with nodal metastasis), 20 advanced gastric carcinomas (AGC)
(ten cases with no nodal metastasis, ten cases with nodal metastasis). We found
that abnormal expression of p16 and p27 increased with the progression of tubular
adenomas to advanced gastric cancers. Inverse relationship between pRb and p16
proteins was found in a small portion of the gastric tumors. Expressions of pRb
and cdk4 were consistently high in benign and malignant gastric tumors.
Expression of cyclin D1 and cyclin E rather decreased with the tumor progression.
In conclusion, losses of p16 and p27 seem to play a significant role during the
gastric carcinogenesis, and the G1 checkpoint cell cycle proteins such as pRb,
cdk4, cyclin D1, and cyclin E variably participate in the gastric carcinogenesis
and metastasis by the mechanisms which are yet unknown; thus, further studies
need to be performed to elucidate the mechanisms.
PMID- 10779642
TI - Possible role of hepatocyte growth factor/scatter factor and activin A produced
by the target organ in liver metastasis.
AB - The molecular mechanism of organ-specific metastasis to the liver remains largely
unknown. However, it is conceivable that paracrine growth factors produced by a
target organ induce migration and proliferation of malignant cells to that organ,
and this is the cause of organ-specific metastasis. In this study, we
investigated the effect of hepatocyte growth factor/scatter factor (HGF/SF) and
activin A, which are known to be produced by the liver, on the motility and
growth of liver-metastatic cell line FBJ-LL. HGF/SF and activin A induced
motility synergistically, but they did not affect the proliferation of FBJ-LL
cells. Expression of the HGF/SF receptor, the c-met gene, and the activin
receptor type IA, type IB, and type IIA genes in FBJ-LL cells was detected by
reverse transcription polymerase chain reaction. These findings suggest that both
HGF/SF and activin A promote organ-specific metastasis to the liver by induction
of migration through their specific receptors on liver-metastatic cells.
PMID- 10779643
TI - Frequency and markov chain analysis of amino-acid sequences of human tumour
necrosis factor.
AB - The amino-acid sequence of human tumour necrosis factor was measured according to
two- and three-amino-acid sequences. The measured frequency and probability were
compared with predicted frequency and probability. Of 232 two-amino-acid
sequences in human tumour necrosis factor, 64 (27.586%) and 24 (10.345%)
sequences can be explained by the predicted frequency and the predicted
probability according to a purely random mechanism. Of 243 non-appeared two-amino
acid sequences in human tumour necrosis factor, 176 (72. 428%) and 42 (17.284%)
sequences can be explained by the predicted frequency and the predicted
probability according to a purely random mechanism. No measured Markov transition
probability matches the predicted conditional probability. No more-than-two-amino
acid sequences can be explained by a purely random mechanism.
PMID- 10779644
TI - Different kinases phosphorylate nucleophosmin/B23 at different sites during G(2)
and M phases of the cell cycle.
AB - The recombinant GST-nucleophosmin/B23 and the truncated mutants were tested for
phosphorylation in cell-free extracts of G(2) and M phases or by purified
kinases. Our results indicated that a threonine residue at amino acids (a.a.) 185
240 was phosphorylated by cdc2 kinase during the entry of mitosis while the
serine phosphorylation site at the middle acidic portion of the molecule (a. a.
83-152) was phosphorylated by casein kinase II during G(2) phase. Our results
also showed that there was possibly another serine phosphorylation at site other
than the middle portion of nucleophosmin/B23 (a.a. 83-152) during the entry of
cells into mitosis. The demonstration of the characteristic changes in
phosphorylation of nucleophosmin/B23 during the cell cycle implicates important
role of nucleophosmin/B23 in the control of the fate of nucleoli and cell growth.
PMID- 10779645
TI - Expression of the 37-kDa laminin binding protein in murine lung tumor cell
correlates with tumor angiogenesis.
AB - Expression of the 37-kDa laminin binding protein (37LBP), a precursor protein of
the 67-kDa laminin receptor, correlates well with the biological aggressiveness
of cancer cells. Previously, we have established murine lung cancer cell lines
T11 and T15, in which 37LBP expression was remarkably diminished, and reported
that the mean survival time of the T11 and the T15-recipients was significantly
prolonged compared with that of the control cell lines (P29 and T42). In the
present study, immunohistochemical findings of the tumors demonstrated that the
microvessel density in the T11 (28. 1+/-7.2/mm(2)) and in the T15 tumor (29.7+/
6.5/mm(2)) were significantly lower than that observed in P29 (46.3+/-8.7/mm(2))
or in T42 (50.5+/-4.4/mm(2)). Expression of vascular endothelial growth factor
(VEGF) was repressed in T11 and T15 compared with its expression in P29 and T42.
It was also shown that conditioned media of T11 and T15 cells exhibited
significantly reduced proliferation and migration of the capillary endothelial
cells. These results suggest that decreased expression of 37LBP in antisense-RNA
transfectant may relate to its low tumorigenicity, and that this effect may be
partly caused by the diminished tumor angiogenesis of murine lung cancer.
PMID- 10779646
TI - Mutational analysis of the p27(kip1) gene in hepatocellular carcinoma.
AB - p27(Kip1) is an inhibitor of cyclin-dependent kinase. It has been reported that
reduced p27(Kip1) expression is present in human hepatocellular carcinoma. To
determine the role of p27(Kip1) in hepatocarcinogenesis, 46 cases with
hepatocellular carcinomas were studied. p27(Kip1) mutation was first screened by
single strand conformation polymorphism, and direct DNA sequencing was then
performed on those cases with mobility shifts. Two polymorphism sites were found.
One is a previously described polymorphism at codon 109 (GTC-->GGC) which was
found in two cases. The second polymorphism was identified at codon 55 (GCG-
>GCA) in six of the 46 cases. However, the polymorphism at codon 55 was also
present in seven of 93 healthy controls (7.5%), indicating that it is not
associated with a predisposition for development of hepatocellular carcinoma
(Fisher's exact test, 0.05). These results show that p27(Kip1) mutation is not a
frequent event in human hepatocellular carcinoma, and suggest that it may be
inactivated predominantly by transcriptional and/or posttranscriptional
regulation rather than genomic aberrations.
PMID- 10779647
TI - Lack of mutation at p16INK4A gene but expression of aberrant p16INK4A RNA
transcripts in human ovarian carcinoma.
AB - Alterations of the p16INK4A gene are frequent in various human cancers. We
investigated p16INK4A gene status in 20 ovarian carcinomas by PCR (polymerase
chain reaction), PCR-SSCP (polymerase chain reaction-single strand conformation
polymorphism) and sequencing techniques. None of the primary tumors showed any
mutational or deletional events. However, 19 out of 20 tumors displayed both a
methylated and an unmethylated p16INK4A promoter. In some of these samples, we
detected aberrant p16INK4A transcripts, with partial deletions of both exons 1
and 2, which could not encode a functional p16INK4A protein. The sequences of the
aberrant mRNA revealed common 4-7 nucleotide sequences before and after the
deleted region, which might cause abnormal splicing of mRNA transcripts. These
results suggest that both promoter methylation and aberrant mRNA processing may
interfere with p16INK4A expression in ovarian tumors.
PMID- 10779648
TI - Low levels of NPM gene expression in UV-sensitive human cell lines.
AB - Nucleophosmin (NPM) is a major nuclear matrix protein associated with neoplastic
growth in various cell types. We recently suggested that expression of the NPM
gene is involved in an increased resistance to UV irradiation in human cells
against the cell-killing effects of UV (mainly 254nm wavelength far-ultraviolet
ray) [Y. Higuchi, K. Kita, H. Nakanishi, X-L. Wang, S. Sugaya, H. Tanzawa, H.
Yamamori, K. Sugita, A. Yamaura, N. Suzuki, Biochem. Biophys. Res. Commun. 248
(1998) 597-602]. In the present study, expression levels of the NPM gene were
examined in human cell lines with a high sensitivity to UV cell-killing. Cockayne
syndrome patient-derived cell lines, CSAI and CSBI, and the Xeroderma pigmentosum
patient-derived cell line, XP2OS(SV), XP13KY, XP3KA, XP6BE(SV), XP101OS and
XP3BR(SV), have been investigated for their NPM mRNA expression with Northern
blotting analysis. All of these UV-sensitive cells demonstrated lower expression
levels compared with those of normal fibroblast cells, FF, or an UV-resistant
cell line, UH(r)-10; quite a lower level of expression in XP205(SV) cells after
UV irradiation in contrast to a distinguishable increase in the expression in
UV(r)- cells. These results confirmed an intimate correlation between degree of
UV sensitivity and expression levels of the NPM gene in human cells.
PMID- 10779649
TI - Clinical significance of lymph node micrometastasis of pN0 esophageal squamous
cell carcinoma.
AB - The lymph nodes of 59 patients with pN0 esophageal squamous cell carcinomas were
examined immunohistochemically using cytokeratin (CK) antibody. Primary tumors
were immunostained with cyclin D1 (CD1) and E-cadherin (E-cad) antibody. Lymph
node micrometastasis (MM) was found in 39 (55.5%) patients. Tumor recurrence was
found in 17 patients and all but one of them had MM. The 5-year survival rate was
significantly poorer in patients with MM than in those without MM. Almost all
patients with positive CD1 and negative E-cad expression had MM. The examination
of CD1 and E-cad expression in primary tumors may be useful for predicting MM.
PMID- 10779650
TI - Carcinogen dose-dependent variation in the transgene mutation spectrum in
urethane-induced lung tumors in transgenic mice carrying the human prototype c-Ha
ras gene.
AB - Urethane-induced lung tumors and their genetic changes were investigated in
transgenic (Tg) mice carrying a human prototype c-Ha-ras gene (rasH2 mice). Male
and female rasH2 mice and non-transgenic (non-Tg) littermates were injected
intraperitoneally with 1000 mg/kg of urethane once or three times at 2-day
intervals. Hyperplasias and adenomas of the lung were observed in all animals of
each group from week 10, and carcinomas were observed in male and female rasH2
mice of the triple injection group from week 10 and female non-Tg mice of the
single injection group at 15/20 weeks. The multiplicities of lung proliferative
lesions including hyperplasias, adenomas and carcinomas, in treated rasH2 mice
were significantly higher than those in treated non-Tg mice. CAG to CTG
transversions were observed in the c-Ha-ras gene in these lung proliferative
lesions of rasH2 mice of the single injection group at high incidence (male:
58.3%, female: 62.5%), but no mutations of the mouse c-Ki-ras gene were evident
in either rasH2 or non-Tg mice. In the triple injection group, transgene
mutations were detected at a relatively low incidence, and mouse c-Ki-ras gene
mutations(CAA to CGA) were observed in both rasH2 and non-Tg mice. These results
suggest that the variation of the lesions induced by different doses of urethane
was not the cause of the variation of the mutation spectrum and mutations of both
transgene and mouse c-K-ras gene are not principal genetic events in urethane
induced lung proliferative lesions in rasH2 mice.
PMID- 10779651
TI - Organ-dependent modifying effects of oltipraz on N-nitrosobis(2-oxopropyl)amine
(BOP)-initiation of tumorigenesis in hamsters.
AB - 5-(2-Pyrazinyl)-4-methyl-1,2-dithiole-thione (oltipraz), a substituted 1,2
dithiole-3-thione, is known to inhibit tumorigenesis induced by variety of
carcinogens in several animal model systems. In the present experiment, the
modifying effects of dietary oltipraz, given during N-nitrosobis(2
oxopropyl)amine (BOP) initiation of carcinogenesis, were investigated in Syrian
hamsters. A total of 120 six-week-old females were divided into six groups.
Groups 1-3 (30 animals each) were thrice given subcutaneous injections of BOP (10
mg/kg, body weight) at 1 week intervals and fed diets supplemented with 400 or
200 ppm of oltipraz or basal diet alone, starting 1 week prior and finishing 1
week after the carcinogen exposure. Groups 4-6 (10 animals each) were similarly
treated without application of BOP. At the end of the 52nd experimental week, all
surviving animals were autopsied and examined histopathologically for
proliferative lesions of the major target organs for BOP tumorigenicity,
including pancreas, liver, kidney, and lung. The incidences and multiplicity of
adenocarcinomas of the pancreas were higher in groups 1 and 2 than in group 3
although without statistical significance. The incidence of pancreatic duct
dysplasias was significantly (P<0.05) increased in group 2 (62.0%) but not in
group 1 (50.0%) as compared with group 3 (46.6%). While the incidences of
alveolar adenomas and carcinomas were significantly (P<0.05) decreased by the
high dose, the multiplicities of hepatocellular adenomas, cholagiocellular
carcinomas and gall bladder adenomas were elevated in the BOP/oltipraz groups
(P<0.05). The results of the present study suggest that oltipraz exerts organ
dependent modifying effects on BOP-induced carcinogenesis in hamsters when given
in the initiation stage.
PMID- 10779652
TI - Prognostic significance of p53 mutations in non-small cell lung cancer: a meta
analysis of 829 cases from eight published studies.
AB - Mutation of the p53 tumor suppressor gene is considered a possible marker of poor
survival among patients with non-small cell lung cancer (NSCLC). This report
presents the results of a meta-analysis of the available data addressing this
issue. Using previously described methods, a protocol was developed for a meta
analysis examining the prognostic significance of p53 mutations in NSCLC. Two
year survival data derived from 829 patients in eight published studies were
analyzed using a general variance-based method employing confidence intervals
described by Greenland (Epidemiol. Rev. 9 (1986) 1-30). The outcome of interest
was a summary relative risk (RRs) reflecting the risk of death at 2 years
associated with p53 mutation positive versus p53 negative disease. Prior to
calculation of a RRs, an analysis for homogeneity (Q) showed Q to equal 22.3.
With 8 degrees of freedom, this yielded a P value corresponding to P<0.005. This
indicated substantial heterogeneity across studies in terms of their estimate of
effect. Although a RRs of 1.52 was found when all eight studies were combined
(favoring a negative prognostic role for p53 mutation), the validity of this
estimate is questionable since the existing heterogeneity indicates that factors
other than p53 mutation account for the variability in RRs across studies.
Sensitivity analyses suggested that selection bias might represent an important
source of variability in that p53 mutations may differ in their effects on
biological behavior of NSCL tumors. Other possible confounders include smoking
history, race, geographic location of study and socio-economic status. The
available data do not support a clear role for p53 mutation as a prognostic
marker in NSCLC. It appears that multiple sources of bias may contribute to
spurious association of p53 mutation status and survival. Future analyses must
control for possible confounders in order to determine whether certain p53
mutations are truly associated with poor clinical outcome.
PMID- 10779653
TI - Perils in the pursuit of mechanisms.
PMID- 10779654
TI - Vulvodynia: an introduction and critical review of a chronic pain condition.
AB - Vulvodynia, or chronic vulvar discomfort, has become an increasingly recognized
complaint in the medical literature. However, classification, assessment, and
treatment for vulvodynia have not been universally established. There is a
serious need for greater understanding of this disorder since evidence suggests,
although not life-threatening, vulvodynia appears to have a significant impact on
quality of life. This article reviews the medical and psychological literature on
vulvodynia published since 1983, the first year vulvodynia was recognized as a
diagnosis in the medical literature. The purpose of this article is to provide a
review of the literature on diagnostic issues, treatment options, and
psychosocial sequelae with the aim of highlighting areas in need of future
research. Finally, suggestions are made for considering vulvodynia from a
multidimensional, chronic pain perspective.
PMID- 10779655
TI - Serotonin receptor subtypes involved in the spinal antinociceptive effect of 5-HT
in rats.
AB - The present study was designed to investigate which subtypes of spinal 5-HT
receptors are involved in 5-HT-induced antinociception using the mechanical pain
test. Serotonin and various selective antagonists or agonists for 5-HT receptor
subtypes (5-HT(1A), 5-HT(1B), 5-HT(2A), 5-HT(2C), 5-HT(3) and 5-HT(4)) were
administered intrathecally (i.t.) in rats. The i.t. injection of 5-HT (1 microg)
produced significant antinociceptive effects using the paw pressure test.
Pretreatment with the 5-HT(2C) receptor antagonist mesulergine (1 and 10 microg)
and the 5-HT(3) receptor antagonist tropisetron (1 and 10 microg) reversed
totally the antinociception induced by 5-HT. Furthermore, at a dose of 10 microg,
both the 5-HT(2A) receptor antagonist ketanserin and the 5-HT(1B) receptor
antagonist penbutolol, but neither the 5-HT(1A) receptor antagonist WAY 100635
nor the 5-HT(4) receptor antagonist GR113808, attenuated the antinociceptive
effect induced by 5-HT. In addition, an i.t. injection of the 5-HT(3) agonist
mCPBG induced significant antinociceptive effects whereas the 5-HT(2) agonist DOI
did not produce analgesia. These results suggest that although the precise degree
of the involvement of spinal serotonergic 5-HT(3) receptors remains to be
elucidated due to some differences in the effect of agonists or antagonists,
these receptors seem to play a role in the antinociceptive effect of 5-HT against
a mechanical acute noxious stimulus. The involvement of 5-HT(2C) is more
questionable due to the observed discrepancies between the effects of the used
agonist and antagonist. 5-HT(1A) and 5-HT(4) receptors do not seem to be
involved. In addition, a possible functional interaction between spinal
serotonergic receptors may exist.
PMID- 10779656
TI - Effect of preoperative oral dextromethorphan on immediate and late postoperative
pain and hyperalgesia after total abdominal hysterectomy.
AB - Dextromethorphan is a noncompetitive N-methyl-D-aspartate (NMDA) receptor
antagonist known to inhibit wind-up and NMDA-mediated nociceptive responses of
dorsal horn neurons. Experimental and clinical studies indicate that NMDA
receptor antagonists may potentiate the effect of analgesics such as morphine,
local anesthetics and NSAIDs. Results from previous clinical studies of
dextromethorphan in postoperative pain are conflicting, possibly related to
administration of insufficient doses of the drug. Fifty patients scheduled for
non-malignant elective abdominal hysterectomy in general anesthesia were
randomized to receive oral dextromethorphan 150 mg, or placebo 1 h before
surgery. The patients received patient-controlled analgesia with morphine for 24
h postoperatively as the only analgesic. Patient-controlled analgesia (PCA)
morphine consumption was reduced with 30% from 0-4 h after operation in patients
receiving dextromethorphan compared with placebo (P=0.02); no differences were
observed from 5-24 h postoperatively. There were no significant differences
between groups for visual analogue scale scores at rest, during cough, or during
mobilization, pressure pain detection thresholds, von Frey hair pain detection
thresholds, or peak flow. At 24 h after operation, hyperalgesia to von Frey hair
stimulation proximal to the surgical wound was easily detected in 23 of 25
patients receiving dextromethorphan, and in 22 of 25 patients receiving placebo,
with no significant difference between groups. Pooled data from both groups
showed a weak but significant correlation between the extent of hyperalgesia at
24 h after operation, and total 24 h postoperative PCA morphine consumption
(Rs=0.28, P=0.05). Three months postoperatively, hyperalgesia was still
detectable in 18 of 22 examined patients in the dextromethorphan group, and in 16
of 23 patients in the placebo group, without statistical differences between
groups. There were no significant differences in side-effects (nausea, vomiting,
sedation). In conclusion, oral dextromethorphan 150 mg reduced PCA morphine
consumption immediately (0-4 h) after hysterectomy, without prolonged effects on
pain or wound hyperalgesia. A positive correlation between the magnitude of wound
hyperalgesia at 24 h after operation, and total 24 h postoperative PCA morphine
consumption was demonstrated.
PMID- 10779657
TI - Depletion of macrophages reduces axonal degeneration and hyperalgesia following
nerve injury.
AB - Inflammatory mechanisms are believed to play an important role in hyperalgesia
resulting from nerve injury. Hyperalgesia following nerve injury is temporally
linked with Wallerian degeneration and macrophage recruitment, and is reduced in
WLD mice, in which Wallerian degeneration is delayed. We sought more direct
evidence that macrophages contribute to hyperalgesia and Wallerian degeneration
by depleting macrophages with liposomes loaded with dichloromethylene
diphosphonate (clodronate, Cl(2)MDP). Rats were subjected to partial ligation of
the sciatic nerve. Intravenous injection of liposome-encapsulated clodronate
reduced the number of macrophages in the injured nerve, alleviated thermal
hyperalgesia and protected both myelinated and unmyelinated fibres against
degeneration. The results confirm the role of circulating monocytes/macrophages
in the development of neuropathic hyperalgesia and Wallerian degeneration due to
partial nerve injury. Macrophage depletion immediately after nerve injury could
have some clinical potential in prevention of neuropathic pain.
PMID- 10779658
TI - Spatial mapping of the zone of secondary hyperalgesia reveals a gradual decline
of pain with distance but sharp borders.
AB - The purpose of this study was to examine how pain to punctate mechanical stimuli
varies with position within the zone of secondary hyperalgesia. Secondary
hyperalgesia was produced by an intradermal injection of capsaicin (50 microg)
into the volar forearm of human volunteers (n=9). Before and at 20, 60 and 100
min after the capsaicin injection, a computer-controlled electromechanical
stimulator was used to deliver controlled-force stimuli to the skin via a 12-mm
wide, 100-microm thick blade probe. Three forces (16, 32 and 64 g; 1 s) were each
applied in a random order to 10 sites spaced in 1-cm increments along a line
starting 1 cm from the injection site and ending near the wrist. At 40 and 80 min
after capsaicin injection the 'zone of hyperalgesia' was determined with use of a
hand-held 20-g von Frey probe. Whereas, before capsaicin, the blade probe
produced little or no pain, after capsaicin the 32-g and 64-g stimuli evoked pain
consistently within but not outside the border of secondary hyperalgesia
determined with the von Frey probe. Within the zone of hyperalgesia the average
pain ratings to the 64-g stimulus decreased exponentially with distance from the
injection site. Surprisingly, the space constant for this exponential decay was
large (about 18 cm), and thus the decrease in pain ratings from the center to the
edge of the secondary zone was small (37%). However, pain ratings dropped
precipitously just outside the zone of secondary hyperalgesia. This finding
unlikely reflects a ceiling effect because pain ratings within the zone of
secondary hyperalgesia increased linearly with force. The relatively uniform pain
ratings to the blade stimuli within the zone of secondary hyperalgesia and the
sharp border that delimits the zone of hyperalgesia indicate that this sensory
disturbance approaches being an 'all-or-nothing' phenomenon. Thus, a two-state
model for central plasticity is needed to explain secondary hyperalgesia.
PMID- 10779659
TI - Painful neuropathy decreases membrane calcium current in mammalian primary
afferent neurons.
AB - Hyperexcitability of the primary afferent neuron leads to neuropathic pain
following injury to peripheral axons. Changes in calcium channel function of
sensory neurons following injury have not been directly examined at the channel
level, even though calcium is a primary second messenger-regulating neuronal
function. We compared calcium currents (I(Ca)) in 101 acutely isolated dorsal
root ganglion neurons from 31 rats with neuropathic pain following chronic
constriction injury (CCI) of the sciatic nerve, to cells from 25 rats with normal
sensory function following sham surgery. Cells projecting to the sciatic nerve
were identified with a fluorescent label applied at the CCI site. Membrane
function was determined using patch-clamp techniques in current clamp mode, and
in voltage-clamp mode using solutions and conditions designed to isolate I(Ca).
Somata of peripheral sensory neurons from hyperalgesic rats demonstrated
decreased I(Ca). Peak calcium channel current density was diminished by injury
from 3.06+/-0.30 pS/pF to 2. 22+/-0.26 pS/pF in medium neurons, and from 3.93+/
0.38 pS/pF to 2. 99+/-0.40 pS/pF in large neurons. Under these voltage and
pharmacologic conditions, medium-sized neuropathic cells lacked obvious T-type
calcium currents which were present in 25% of medium-sized cells from control
animals. Altered Ca(2+) signalling in injured sensory neurons may contribute to
hyperexcitability leading to neuropathic pain.
PMID- 10779660
TI - Intrathecally administered spermine produces the scratching, biting and licking
behaviour in mice.
AB - Intrathecal (i.t.) administration of spermine (0.1-10000 fmol), an endogenous
polyamine, produced the behavioural response mainly consisting of biting and/or
licking of the hindpaw along with a slight hindlimb scratching directed toward
the flank in mice, which peaked at 5-15 min and almost disappeared at 30 min
after an injection. The behaviour induced by spermine (10 pmol) was dose
dependently inhibited by intraperitoneal injection of morphine (0.125-0.5 mg/kg).
The characteristic behaviour was also inhibited dose-dependently by i.t. co
administration of ifenprodil (62.5-4000 pmol), a competitive antagonist of the
polyamine recognition site on N-methyl-D-aspartate (NMDA) receptor ion-channel
complex, and D(-)-2-amino-5-phosphonovaleric acid (D-APV) (0.5-2 nmol) and 3-((+/
)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) (7. 8-500 pmol), the
competitive NMDA receptor antagonists, and (5R, 10S)-(+)-5-methyl-10,11-dihydro
5H-dibenzo[a,b]cycloheptene-5, 10-imine hydrogen maleate (MK-801) (0.5-4 nmol),
an NMDA ion-channel blocker, but not by 6-cyano-7-nitroquinoxaline-2,3-dione
(CNQX), a non-NMDA receptor antagonist. Both (2S, 3S)-[cis-2-(diphenylmethyl)-N
[(2-methoxyphenyl)-methyl]-1-azabicy clo [2.2.2]octane-3-amine] (CP-96,345), a
non-peptidic neurokinin-1 (NK-1) receptor antagonist, and CP-96,344, its inactive
2R,3R enantiomer, inhibited spermine-induced behavioural response in a dose
dependent manner. However, [Tyr(6), D-Phe(7), D-His(9)]-substance P(6-11)
(sendide) and [D-Phe(7), D-His(9)]-substance P(6-11), the selective antagonists
for NK-1 receptors, were without affecting spermine-induced behaviour. These
results indicate that spermine-induced behaviour is mediated through the
polyamine recognition site on NMDA receptor ion-channel complex without the
involvement of substance P system in the mouse spinal cord.
PMID- 10779661
TI - Spinal interleukin-1beta reduces inflammatory pain.
AB - Inflammation or injury often lead to chronic pain states such as hyperalgesia
where the perception of a normally painful stimulus is significantly exaggerated.
Interleukin-1beta (IL-1beta) is a cytokine that is an important mediator of the
inflammatory response. In addition, IL-1beta has been implicated in the
modulation of pain transmission in both the peripheral and central nervous
systems. We evaluated the spinal effect of this cytokine in the presence and
absence of a peripheral carrageenan inflammation in rats since the spinal cord is
a major region of the central nervous system in which nociceptive input is
processed and modulated. Our results indicate that intrathecal IL-1beta has no
effect on the latency of paw withdrawal in response to a noxious thermal
stimuluation in normal rats. In contrast, we have observed that IL-1beta produces
significant antinociception when administered intrathecally in rats with
peripheral inflammation (carrageenan model). The IL-1beta effect appears to be
selective as it is reversed when IL-1beta is administered in the presence of an
IL-1beta neutralizing antibody. We evaluated some putative mechanisms of this IL
1beta-mediated antinociception and found it to be non-opioid-dependent.
Collectively, these data indicate that intrathecal IL-1beta has no effect on the
processing of thermal nociceptive information in the absence of a peripheral
inflammation. Therefore, the response to acute pain remains normal in these rats.
In contrast, IL-1beta is antinociceptive when applied spinally during
inflammation. These results indicate that IL-1beta reduces inflammatory
hyperalgesia while sparing the protective functions of acute pain. This study
offers new insights into the role of IL-1beta and nociceptive processing at the
level of the spinal cord and suggests that development of IL-1beta agonists may
be an alternative to opiate based therapies in the treatment of inflammatory
pain.
PMID- 10779663
TI - Heme oxygenase type 2 plays a role in formalin-induced nociception.
AB - Although much attention has been focused in recent years on nitric oxide synthase
(NOS) as an enzyme intimately involved in many types of nociceptive signaling,
the enzyme heme oxygenase (HO) has received little attention. Yet, HO produces
gaseous second messenger molecule CO which, like NO, has proven to be an
important neurotransmitter in the CNS. In these studies we provide detailed
evidence that HO activity is critical to formalin-induced licking behavior in
mice. The HO inhibitor tin protoporphyrin (Sn-P) dose-dependently reduced
formalin-stimulated licking behavior in both phases of the formalin assay. This
apparent analgesic effect was unlikely due to the non-specific effects of this
agent as Sn-P did not alter rotarod performance, and the blood-brain barrier
impermeant HO inhibitor zinc protoporphyrin (Zn-P) had little effect on licking
times. We also hypothesized that heme oxygenase type 2 (HO-2) was the specific
isoform of HO involved in nociception. Mice with a targeted disruption of the HO
2 gene were found to have greatly reduced licking times. Furthermore, Sn-P did
not further reduce licking times when administered to HO-2 knockout animals.
Taken together our evidence indicates that HO plays an important role in
nociceptive signaling related to inflammatory-type pain, and that HO-2 is the
isozyme mediating this nociception.
PMID- 10779662
TI - Amino acid release into the knee joint: key role in nociception and inflammation.
AB - This study examined the release of several amino acids after induction of knee
joint inflammation in rats using kaolin and carrageenan. During the initial 10
min collection after knee joint injection with the irritants, the concentration
of glutamate and the nitric oxide metabolites, arginine and citrulline, doubled.
This increase persisted for at least two hours. During the same time period
aspartate concentrations remained unchanged. Direct knee joint administration of
lidocaine prevented the increases in amino acid concentration measurable by
microdialysis probe inserted into the joint. These data suggest the possibility
that glutamate may be released by neuronal endings in the joint.
PMID- 10779664
TI - Low intensity vagal nerve stimulation lowers human thermal pain thresholds.
AB - The effect of vagal nerve stimulation (VNS) on thermal pain sensation was studied
in eight subjects who had vagal nerve stimulators surgically implanted for
purposes of seizure control. Prior to their involvement in the study, all
subjects had the intensity of their VNS (30 Hz, 0.5 ms, 1.0-2.75 mA) adjusted
upwards until achieving their desired clinical effect of reduced seizures.
Thermal pain thresholds were determined using a Medoc TSA-2001 with a thermode
applied to the skin of the forearm. During VNS at settings 100% of those used
clinically to control their seizures, subjects showed a statistically significant
decrease in their thermal pain threshold of 1.1+/-0.4 degrees C. Acute effects of
graded VNS on thermal pain thresholds were determined in seven of the subjects
after cessation of chronic VNS. Two thermal threshold measurements were obtained
while the subject received sham stimulation (0 mA intensity), during tactile
control stimulation and during 30 s of VNS at intensities approximately 33, 66
and 100% of the settings utilized to control their seizures. Tactile control
stimulation was provided by electrical stimulation of the skin of the ankle with
the intensity adjusted by the patient to match the intensity of any sensations
felt in the neck during VNS. Subjects were not aware of the settings employed.
Their stimulator was adjusted with each trial and an ascending/descending
ordering of intensity was utilized with an inter-trial interval of 2 min. Thermal
pain thresholds were significantly decreased in relation to tactile control
stimulation at all intensities of VNS tested with the greatest effect occurring
at the 66% level. Subjects were also monitored non-invasively and hemodynamic
responses to VNS were determined. No significant alterations in hemodynamic
variables were observed. The findings of this human study are consistent with
experiments in non-human animals which demonstrate a pro-nociceptive effect of
low intensity VNS.
PMID- 10779665
TI - Sex-dependent effects of reported familial pain history on recent pain complaints
and experimental pain responses.
AB - Previous research has demonstrated that both sex and familial pain history can
influence clinical pain, and sex is known to affect experimental pain responses.
However, the potential interactive effects of sex and family history on pain
related symptoms and experimental pain have not been investigated. This
experiment examined recent pain complaints and laboratory pain responses as a
function of sex and reported family history of pain in 212 (122 female, 90 male)
young adults. All subjects completed questionnaires regarding family history of
pain, recent pain experiences, and psychological measures of hypervigilance.
Then, warmth detection thresholds, heat pain thresholds and heat pain tolerances
were determined. Results revealed sex-dependent influences of familial pain
history on recent pain complaints and experimental pain responses. Specifically,
a positive family history of pain was associated with increased reports of pain
over the previous month and poorer general health as well as enhanced sensitivity
to thermal stimuli among females but not males. Higher levels of hypervigilance
accounted for some of the family history effects on recent pain complaints but
not experimental pain measures. Potential mechanisms underlying these effects of
family history among females are discussed.
PMID- 10779666
TI - Allodynia and hyperalgesia induced by herpes simplex virus type-1 infection in
mice.
AB - Human subjects infected with herpes or varicella-zoster viruses complain of pain,
such as allodynia, in or near the region with vesicles. However, the mechanisms
of the pain are unclear. We show for the first time that infection with herpes
simplex virus type-1 (HSV-1) induces allodynia and hyperalgesia in mice. When HSV
1 was inoculated on the hind paw of the mouse, eruption appeared on the back on
day 5 post-inoculation, and zosteriform skin lesions were developed on the
inoculated side. Allodynia and hyperalgesia became apparent in the hind paw on
the inoculated side on day 5 and persisted until at least day 8. HSV-1 DNA was
detected in the dorsal root ganglia from days 2 to 8 post-inoculation, with a
peak effect on day 5. The application of heat-inactivated HSV-1 induced no
allodynia, hyperalgesia and skin lesion. When started from days 0 or 2, repeated
treatment with acyclovir, anti-HSV-1 agent, inhibited the appearance of
allodynia, hyperalgesia, eruption and the viral proliferation in the dorsal root
ganglia. In contrast, when started from days 5 or 6, acyclovir treatment slightly
inhibited the development of skin lesions and the viral proliferation, but not
allodynia and hyperalgesia. These results suggest that the propagation of HSV-1
in the dorsal root ganglia produces allodynia and hyperalgesia as a result of
functional abnormality of the sensory neurons in mice. This may be a useful model
for studying the mechanisms of herpetic pain.
PMID- 10779667
TI - Transient changes in the synthesis of nitric oxide result in long-term as well as
short-term changes in acetic acid-induced writhing in mice.
AB - A single injection of nitric oxide (NO) synthase (NOS) inhibitors prevents the
development of persistent hyperalgesia induced by various manipulations,
suggesting that NO precipitates long-term changes in nociception. We examined the
possibility that inhibition of NOS may also be sufficient to produce long-term
decreases in nociceptive assays, such as writhing, that are known to be sensitive
to the short-term effects of NOS inhibitors. We characterized short- and long
term effects of NOS inhibitors, N(omega)-nitro-L-arginine (L-NAME) or 7-nitro
indazole (7-NI) injected intrathecally (i.t.) in mice on acetic acid-induced
writhing. Doses of L-NAME that had no effect on hot plate or tail flick latencies
inhibited writhing (0. 01-30 nmol) as well as spinal nNOS activity (5 and 100
nmol) when injected i.t. 60-90 min before testing. Anti-nociception was not
mimicked by D-NAME but was prevented by co-administration with the NO precursor,
L-arginine. Injection i.t. of 7-NI (30 min), a selective inhibitor of neuronal
NOS (nNOS), inhibited NOS activity in the spinal cord and produced anti
nociception, confirming that writhing is sensitive to inhibition of nNOS.
Although the acute action of both NOS inhibitors dissipated completely by 3-6 h,
a delayed and prolonged inhibition of writhing was again observed 24 h after L
NAME (5-100 nmol), a time when spinal NOS activity was no longer inhibited by L
NAME (5 and 100 nmol) or 7-NI (25 nmol). This novel effect appears to be
initiated by the transient inhibition of nNOS as delayed anti-nociception was
mimicked by 7-NI at doses (10-100 nmol) that no longer inhibited spinal nNOS (25
nmol) at 24 h. Co-administration with L-arginine prevented the delayed (24 h)
anti-nociceptive effects of L-NAME (30 nmol). L-Arginine (30 and 100 nmol) was
without effect on nociception when administered alone 60 min or 24 h prior to
testing. Together these data indicate that brief changes in the activity of nNOS
induce both long- as well as short-term changes in nociception.
PMID- 10779668
TI - Analgesic profile of the nicotinic acetylcholine receptor agonists, (+)
epibatidine and ABT-594 in models of persistent inflammatory and neuropathic
pain.
AB - The anti-nociceptive and locomotor effects of the nicotinic acetylcholine
receptor (nAChR) agonists (+)-epibatidine and ABT-594 were compared in the rat.
Acute thermal nociception was measured using the tail flick test. Mechanical
hyperalgesia was measured as paw withdrawal threshold (PWT) in response to a
mechanical stimulus in two animal models of persistent pain; (1) 24 h following
subplantar injections of Freund's complete adjuvant (FCA) into the left hind paw
or (2) 11-15 days following a partial ligation of the left sciatic nerve.
Disruption of locomotor function was assessed using an accelerating rotarod
device. In all tests, (+)-epibatidine was significantly more potent than ABT-594.
Both (+)-epibatidine and ABT-594 dose-dependently increased tail flick latencies
but only at doses that also disrupted performance in the rotarod test. On the
other hand, (+)-epibatidine and ABT-594 dose-dependently reversed inflammatory
and neuropathic hyperalgesia at significantly lower doses than that needed to
disrupt performance in the rotarod test. In summary, ABT-594 is less potent than
(+)-epibatidine in assays of acute and persistent pain and in the rotarod assay.
However, ABT-594 displayed a clearer separation between its motor and anti
hyperalgesic effects. This shows that nicotinic agonists with improved
selectivity between the nicotinic receptor subtypes could provide strong
analgesic effects with a much improved therapeutic window.
PMID- 10779669
TI - Teasing apart quality and validity in systematic reviews: an example from
acupuncture trials in chronic neck and back pain.
AB - The objectives of the study were (1) to carry out a systematic review to assess
the analgesic efficacy and the adverse effects of acupuncture compared with
placebo for back and neck pain and (2) to develop a new tool, the Oxford Pain
Validity Scale (OPVS), to measure validity of findings from randomized controlled
trials (RCTs), and to enable ranking of trial findings according to validity
within qualitative reviews. Published RCTs (of acupuncture at both traditional
and non-traditional points) were identified from systematic searching of
bibliographic databases (e.g. MEDLINE) and reference lists of retrieved reports.
Pain outcome data were extracted with preference given to standardized outcomes
such as pain intensity. Information on adverse effects was also extracted. All
included trials were scored using a five-item 0-16 point validity scale (OPVS).
The individual RCTs were ranked according to their OPVS score to enable more
weight to be placed on the trials of greater validity when drawing an overall
conclusion about the efficacy of acupuncture for relieving neck and back pain.
Statistical analyses were carried out on the OPVS scores to assess the
relationship between trial finding (positive or negative) and validity. Thirteen
RCTs met the inclusion criteria. Five trials concluded that acupuncture was
effective, and eight concluded that it was not effective for relieving back or
neck pain. There was no obvious difference between the findings of trials using
traditional and non-traditional points. Using the new OPVS scale, the validity
scores of the included trials ranged from 4 to 14. There was no significant
relationship between OPVS score and trial finding (positive versus negative).
Authors' conclusions did not always agree with their data. We drew our own
conclusions (positive/negative) based on the data presented in the reports. Re
analysis using our conclusions showed a significant relationship between OPVS
score and trial finding, with higher validity scores associated with negative
findings. OPVS is a useful tool for assessing the validity of trials in
qualitative reviews. With acupuncture for chronic back and neck pain, we found
that the most valid trials tended to be negative. There is no convincing evidence
for the analgesic efficacy of acupuncture for back or neck pain.
PMID- 10779670
TI - Evidence for increased plasma levels of calcitonin gene-related peptide in
migraine outside of attacks.
AB - Although calcitonin gene-related peptide (CGRP) has been shown to be elevated in
jugular venous blood of adult migraineurs during acute migraine attacks, it
remains unknown whether CGRP is increased outside of attacks in jugular or
cubital venous blood. The aim of the present study was to compare interictal
plasma levels of CGRP in adult migraine patients and in healthy controls. Twenty
patients with a diagnosis of migraine with or without aura and 20 healthy
controls were included. In blood from the cubital vein, CGRP levels were
significantly higher in patients (75+/-8 pmol/l (mean+/-SEM)) than in controls
(49+/-3 pmol/l) (P=0.005). The subgroup of patients suffering exclusively from
migraine without aura (n=14) also had significantly higher levels of CGRP (82+/
10 pmol/l) than controls (n=20; 49+/-3 pmol/l) (P=0.001). The findings could not
be explained by confounding factors such as age, sex or use of contraceptive
pills. We therefore conclude that CGRP is increased in cubital venous blood of
migraineurs outside of attack. It is hypothesized that this finding may reflect a
long-lasting or permanent abnormal neurogenic vascular control in patients with
migraine.
PMID- 10779671
TI - Towards an objective quantitative assessment of daily functioning in migraine: a
feasibility study.
AB - Migraine is a chronic disabling disorder, with migraine episodes significantly
reducing quality of life and leading to impaired functioning (physically,
socially, emotionally) both at home and at work. We explored whether ambulatory
accelerometry can be used as an objective method to quantify the behavioral
aspects of migraine-related disability. Four body mounted uni-axial piezo
resistive accelerometers were used to quantify the time spent in different body
postures (lying, sitting, standing), physical activities (walking, cycling) and a
general index of body motility during eight migraine attacks and subsequent
recovery periods of six patients in their habitual environment. The migraine
attacks and recovery periods could be monitored after about 1 h, which was the
time required for the investigator to travel to the patient and for the sensors
to be attached. In order to quantify the influence of a migraine episode on daily
activities, we also performed measurements during a headache-free baseline period
of the same patients. Overall, the procedures functioned well, indicating that
ambulatory accelerometry measurements before, during and after a migraine attack
are feasible to perform. Furthermore, our quantitative data revealed that
migraine always influenced behavior by reducing overall body motility and that,
dependent upon the severity of the attack, the effectiveness of acute treatment
and the time of day, the time spent in various body positions, dynamic
activities, and the number of postural transitions were affected. This
feasibility study showed that ambulatory accelerometry can provide the objective
behavioral effect parameters for the evaluation of migraine and its treatment on
daily functioning in the habitual environment of migraine patients.
PMID- 10779672
TI - Experimental muscle pain produces central modulation of proprioceptive signals
arising from jaw muscle spindles.
AB - The aim of the present study was to investigate the effects of intramuscular
injection with hypertonic saline, a well-established experimental model for
muscle pain, on central processing of proprioceptive input from jaw muscle
spindle afferents. Fifty-seven cells were recorded from the medial edge of the
subnucleus interpolaris (Vi) and the adjacent parvicellular reticular formation
from 11 adult cats. These cells were characterized as central units receiving jaw
muscle spindle input based on their responses to electrical stimulation of the
masseter nerve, muscle palpation and jaw stretch. Forty-five cells, which were
successfully tested with 5% hypertonic saline, were categorized as either dynamic
static (DS) (n=25) or static (S) (n=20) neurons based on their responses to
different speeds and amplitudes of jaw movement. Seventy-six percent of the cells
tested with an ipsilateral injection of hypertonic saline showed a significant
modulation of mean firing rates (MFRs) during opening and/or holding phases. The
most remarkable saline-induced change was a significant reduction of MFR during
the hold phase in S units (100%, 18/18 modulated). Sixty-nine percent of the DS
units (11/16 modulated) also showed significant changes in MFRs limited to the
hold phase. However, in the DS neurons, the MFRs increased in seven units and
decreased in four units. Finally, five DS neurons showed significant changes of
MFRs during both opening and holding phases. Injections of isotonic saline into
the ipsilateral masseter muscle had little effect, but hypertonic saline
injections made into the contralateral masseter muscle produced similar results
to ipsilateral injections with hypertonic saline. These results unequivocally
demonstrate that intramuscular injection with an algesic substance, sufficient to
produce muscle pain, produces significant changes in the proprioceptive
properties of the jaw movement-related neurons. Potential mechanisms involved in
saline-induced changes in the proprioceptive signals and functional implications
of the changes are discussed.
PMID- 10779673
TI - Alleviation of mechanical and thermal allodynia by CGRP(8-37) in a rodent model
of chronic central pain.
AB - CGRP(8-37) is a truncated version of calcitonin gene-related peptide (CGRP) that
binds to the CGRP receptor with similar affinity but does not activate the
receptor and is a highly selective CGRP receptor antagonist. CGRP and activation
of its receptor appear to play a role in peripheral inflammatory and neuropathic
models of pain although there is considerable controversy. The aim of this study
was to examine possible anti-nociceptive effects of CGRP(8-37) on a model of
chronic central neuropathic pain known to develop weeks after spinal hemisection.
Adult male Sprague-Dawley rats were given a spinal hemisection (N=34) or a sham
surgery (N=10) at the T13 spinal segment. An externally accessible PE-10
intrathecal catheter that terminated at T13 was used for drug delivery. Animals
were allowed to recover for 4 weeks at which time the hemisected animals
displayed mechanical and thermal allodynia bilaterally, in both forelimbs and
hindlimbs. CGRP(8-37) was delivered just prior to a testing session in 1, 5, 10,
or 50 nM doses in artificial cerebral spinal fluid in 10 microl volumes. CGRP(8
37) was effective in alleviating mechanical and thermal allodynia in a dose
dependent manner (P<0.05). The 50 nM dose was most efficacious for both forelimb
and hindlimb responses (P<0.05). The period of efficacy was 10 min to onset for a
duration of 20 min. Post-drug washout responses were not statistically
significant compared to pre-drug responses. The sham control groups demonstrated
no statistically significant difference at any dose of CGRP(8-37) when compared
to pre-surgical baseline values. In conclusion, CGRP(8-37) is effective in
abolishing mechanical and thermal allodynia produced by spinal hemisection.
Consequently, the CGRP receptor may play a role in chronic central neuropathic
pain and offers a novel therapeutic approach to managing chronic central pain.
PMID- 10779674
TI - Zinc in the extracellular area of the central nervous system is necessary for the
development of kainic acid-induced persistent hyperalgesia in mice.
AB - Kainic acid produces a persistent hyperalgesia when injected intraperitoneally
(i.p.) in the rat or mouse. At higher doses than those needed to influence
nociception, kainic acid induces seizures and translocation of histologically
reactive zinc in the hippocampus. We tested the hypothesis that zinc, localized
in a population of small diameter primary afferent neurons, plays a role in
kainic acid-induced hyperalgesia similar to that in the hippocampus where zinc
translocation accompanies kainic acid-induced seizures. The importance of zinc in
the extracellular area was assessed by the influence of compounds that chelate
divalent cations (disodium calcium ethylene diaminetetraacetate (CaEDTA)) or zinc
(dipicolinic acid (DPA)) on kainic acid-induced hyperalgesia. When measured using
the tail flick assay, thermal hyperalgesia was blocked by pretreatment
intrathecally (i.t.) with either 10 nmol of NaCaEDTA or 1 nmol of DPA, drugs
whose distribution is limited to the extracellular area. Injection of 10 ng zinc
chloride i.t. had no long-term effect on nociception or on kainic acid-induced
hyperalgesia. Whether zinc is translocated in response to a hyperalgesic dose of
kainic acid was determined using the zinc-selective dye, N-(6-methoxy-8-quinolyl)
para-toluenensulfonamide (TSQ), which produces a delicate stain in the neuropil
of the mouse spinal cord as well as a dense stain in the hippocampus. Injection
of a hyperalgesic dose of kainic acid failed to alter TSQ fluorescence in either
the spinal cord or hippocampus, in contrast to the distinct bleaching of TSQ in
the hippocampus 24 h after a convulsant dose of kainic acid. Together these data
suggest that, while not translocated, zinc in the extracellular area is necessary
but not sufficient for the development of kainic acid-induced hyperalgesia.
PMID- 10779675
TI - Extraterritorial neuropathic pain correlates with multisegmental elevation of
spinal dynorphin in nerve-injured rats.
AB - Neuropathic pain is often associated with the appearance of pain in regions not
related to the injured nerve. One mechanism that may underlie neuropathic pain is
abnormal, spontaneous afferent drive which may contribute to NMDA-mediated
central sensitization by the actions of glutamate and by the non-opioid actions
of spinal dynorphin. In the present study, injuries to lumbar or sacral spinal
nerves elicited elevation in spinal dynorphin content which correlated temporally
and spatially with signs of neuropathic pain. The increase in spinal dynorphin
content was coincident with the onset of tactile allodynia and thermal
hyperalgesia. Injury to the lumbar (L(5)/L(6)) spinal nerves produced elevated
spinal dynorphin content in the ipsilateral dorsal spinal quadrant at the L(5)
and L(6) spinal segments and in the segments immediately adjacent. Lumbar nerve
injury elicited ipsilateral tactile allodynia and thermal hyperalgesia of the
hindpaw. In contrast, S(2) spinal nerve ligation elicited elevated dynorphin
content in sacral spinal segments and bilaterally in the caudal lumbar spinal
cord. The behavioral consequences of S(2) spinal nerve ligation were also
bilateral, with tactile allodynia and thermal hyperalgesia seen in both hindpaws.
Application of lidocaine to the site of S(2) ligation blocked thermal
hyperalgesia and tactile allodynia of the hindpaws suggesting that afferent drive
was critical to maintenance of the pain state. Spinal injection of antiserum to
dynorphin A((1-17)) and of MK-801 both blocked thermal hyperalgesia, but not
tactile allodynia, of the hindpaw after S(2) ligation. These data suggest that
the elevated spinal dynorphin content consequent to peripheral nerve injury may
drive sensitization of the spinal cord, in part through dynorphin acting directly
or indirectly on the NMDA receptor complex. Furthermore, extrasegmental increases
in spinal dynorphin content may partly underlie the development of
extraterritorial neuropathic pain.
PMID- 10779677
TI - Dynamics of ethanol translocation in Saccharomyces cerevisiae as detected by
(13)C-NMR.
AB - (13)C-NMR has yielded to the dynamics study of ethanol as carbon and energy
source in the metabolic oscillation of Saccharomyces cerevisiae. Three ethanol
fractions such as media, cytoplasm and mitochondria were observed and
characterised by different longitudinal relaxation times and chemical shifts.
PMID- 10779676
TI - Lumbar transplant of neurons genetically modified to secrete brain-derived
neurotrophic factor attenuates allodynia and hyperalgesia after sciatic nerve
constriction.
AB - Chronic delivery of anti-nociceptive molecules by means of cell grafts near the
pain processing centers of the spinal cord is a newly developing technique for
the treatment of neuropathic pain. The rat neuronal cell line, RN33B, derived
from E13 rat brainstem raphe and immortalized with the SV40 temperature-sensitive
allele of large T antigen (tsTag), was transfected with rat brain-derived
neurotrophic factor cDNA (BDNF), and the BDNF-synthesizing cell line, 33BDNF.4,
was isolated. The 33BDNF.4 cells synthesized mature BDNF protein at permissive
temperature (33 degrees C), when the cells were proliferating, and during
differentiation at non-permissive temperature (39 degrees C) in vitro. The bio
active BDNF protein was also secreted by the cells during both growth conditions,
as measured by ELISA analysis of BDNF content and secretion. The bio-activity of
the BDNF in 33BDNF.4 cell conditioned media was assessed by neurite outgrowth
from E15 dorsal root ganglion (DRG) cultures. A control cell line, 33V1,
transfected with the vector alone, did not synthesize or secrete any significant
BDNF at either growth condition. Both cell lines were used as grafts in a model
of chronic neuropathic pain induced by unilateral chronic constriction injury
(CCI) of the sciatic nerve. Pain-related behaviors, including cold and tactile
allodynia and thermal and tactile hyperalgesia, were evaluated after CCI in the
affected hindpaw. When 33BDNF.4 and 33V1 cells were transplanted in the lumbar
subarachnoid space of the spinal cord 1 week after CCI, they survived greater
than 7 weeks on the pia mater around the spinal cord and the 33BDNF.4 cells
continued to synthesize BDNF in vivo. Furthermore, the tactile and cold allodynia
and tactile and thermal hyperalgesia induced by CCI was significantly reduced
during the 2-7 week period after grafts of 33BDNF.4 cells. The maximal effect on
chronic pain behaviors with the BDNF grafts occurred 2-3 weeks after transplant
and the anti-nociceptive effects of the BDNF cell grafts was permanent.
Transplants of the control 33V1 cells had no effect on the allodynia and
hyperalgesia induced by CCI and these cells did not synthesize BDNF in vivo.
These data suggest that a chronically applied, low local dose of BDNF supplied by
transplanted cells near the spinal dorsal horn was able to reverse the
development of chronic neuropathic pain following CCI. The use of neural cell
lines that are able to deliver anti-nociceptive molecules, such as BDNF, in a
model of chronic pain offers a novel approach to pain management and such
'biologic minipumps' can be developed for safe use in humans.
PMID- 10779678
TI - A new Chinese hamster ovary cell line expressing alpha2,6-sialyltransferase used
as universal host for the production of human-like sialylated recombinant
glycoproteins.
AB - Chinese hamster ovary (CHO) cells are widely employed to produce glycosylated
recombinant proteins. Our group as well as others have demonstrated that the
sialylation defect of CHO cells can be corrected by transfecting the alpha2,6
sialyltransferase (alpha2,6-ST) cDNA. Glycoproteins produced by such CHO cells
display both alpha2,6- and alpha2,3-linked terminal sialic acid residues, similar
to human glycoproteins. Here, we have established a CHO cell line stably
expressing alpha2,6-ST, providing a universal host for further transfections of
human genes. Several relevant parameters of the universal host cell line were
studied, demonstrating that the alpha2,6-ST transgene was stably integrated into
the CHO cell genome, that transgene expression was stable in the absence of
selective pressure, that the recombinant sialyltransferase was correctly
localized in the Golgi and, finally, that the bioreactor growth parameters of the
universal host were comparable to those of the parental cell line. A second step
consisted in the stable transfection into the universal host of cDNAs for human
glycoproteins of therapeutic interest, i.e. interferon-gamma and the tissue
inhibitor of metalloproteinases-1. Interferon-gamma purified from the universal
host carried 40.4% alpha2,6- and 59.6% alpha2,3-sialic acid residues and showed
improved pharmacokinetics in clearance studies when compared to interferon-gamma
produced by normal CHO cells.
PMID- 10779679
TI - The presence of an extractable substance in the CSF of humans with cerebral
vasospasm after subarachnoid haemorrhage that correlates with phosphatase
inhibition.
AB - The cellular events leading to cerebral vasospasm after subarachnoid haemorrhage
are poorly understood, although an increase in smooth muscle myosin light chain
phosphorylation has been observed. This study set out to determine if phosphatase
inhibition may be involved in the pathological maintenance of tension observed
during vasospasm. We found that 1 nM okadaic acid, a type 2A protein phosphatase
inhibitor, elicited an increase in rate of O(2) consumption in the porcine
carotid artery similar to that by cerebrospinal fluid (CSF) from vasospastic
patients (CSF(V), n=5) (control 0.23+/-0.03, CSF(V) 0.84+/-0.16 and okadaic acid
0.85+/-0.02 micromol min(-1) g dwt(-1)). It was also observed that phosphatase
inhibition with 1 nM okadaic acid significantly slowed relaxation after a stretch
in a similar fashion to CSF(V) haemorrhage. CSF from vasospastic subarachnoid
haemorrhage patients, but not from those without vasospasm, contains an
extractable substance which modulates myosin light chain phosphorylation in
vitro. A phosphatase preparation obtained from the porcine carotid artery
dephosphorylated 63+/-2% of the phosphorylated (MLC(20)) substrate in vitro, and
non-vasospastic CSF treated enzyme dephosphorylated 60+/-2.6%. Okadaic acid
inhibited phosphatase dephosphorylated only 7.5+/-1% of the substrate where
CSF(V) treated enzyme dephosphorylated 22+/-2.8% of the substrate. We conclude
that inhibition of smooth muscle phosphatase may be involved in the mechanisms
associated with cerebral vasospasm after subarachnoid haemorrhage.
PMID- 10779681
TI - A lectin from an edible mushroom Pleurotus ostreatus as a food intake-suppressing
substance.
AB - In an experiment in which rats were allowed free access to food and water, the
rats did not eat the diet containing a mushroom Pleurotus ostreatus even if they
were emaciated. A P. ostreatus lectin (POL) was isolated from the mushroom as the
food intake-suppression principle. In hemagglutination inhibition assays, Me
alphaGalNAc was the most potent inhibitor among the monosaccharides tested. Among
all the sugars tested, 2'-fucosyllactose (Fucalpha1-->2Galbeta1-->4Glc) was the
strongest inhibitor and its inhibitory potency was five times greater than that
of Me-alphaGalNAc. POL exhibited a binding ability to bovine submaxillary mucin
(BSM) and asialo-BSM and the other glycoproteins were inert to the binding. The
food intake-suppressing activity of POL was dependent on the dose. The diet
containing 0.1% POL caused a 50% decrease in the food intake of rats against the
control.
PMID- 10779680
TI - Transport of 1,5-anhydro-D-glucitol into insulinoma cells by a glucose-sensitive
transport system.
AB - The uptake of 1,5-anhydro-D-glucitol (1,5-AG) occurs by passive mechanisms in
cells or tissues that have passive glucose transporters. It is known that serum
1,5-AG concentrations are reduced in patients with diabetes mellitus. To
elucidate the metabolism of this substance and its physiological role in
pancreatic beta-cells, we assayed 1,5-AG transport in the insulinoma-derived cell
lines, RINr and MIN6. Both cell lines showed an insulin-insensitive,
concentration-dependent uptake of 1,5-AG with a saturation time of approximately
120 min, and most of the 1,5-AG in the cytoplasm was in the free form. A biphasic
saturation curve was obtained using a wide range of 1,5-AG concentrations,
suggesting that accumulation was mediated by a high affinity and a low affinity
transporter. The high affinity transporter had a K(m) of 10.4 in RINr cells and
13.0 mM in MIN6 cells, and the low affinity transporter had a K(m)100 times,
being much higher than the physiological concentrations of 1,5-AG. These results
indicate that the 1,5-AG carrier system in insulinoma cells is distinct from that
in either the somatic cells or renal tubular cells. These findings also suggest
that a unique 1,5-AG transport system is present in pancreatic beta-cells.
PMID- 10779682
TI - Isolation and characterization of DM40 and DM43, two snake venom
metalloproteinase inhibitors from Didelphis marsupialis serum.
AB - From Didelphis marsupialis serum, two antihemorrhagic proteins were isolated by
DEAE-Sephacel, Phenyl-Sepharose and Superdex 200 and characterized. Their masses
by mass spectrometry were 40318 AMU for DM40 and 42373 and 43010 AMU for DM43,
indicating the presence of isoforms for the last. Molecular masses of 44.8 and
47.3 were obtained by SDS-PAGE, respectively for DM40 and DM43. Both inhibitors
showed isoelectric points lower than 3.5 and glycosylation percentages varying
from 20.5 to 29.0%, as estimated by chemical deglycosylation and amino acid
analysis. N-terminal sequences of the first 17 residues of DM40 and DM43 were
identical except for the exchange of R9 for P9. Both were homologous to oprin, a
similar inhibitor from Didelphis virginiana serum. No evidence of complex
formation between DM40 and DM43 was observed either by native PAGE or gel
filtration chromatography. In addition to the antihemorrhagic activity, DM40 and
DM43 inhibited the hydrolysis of casein, fibrinogen and fibronectin by Bothrops
jararaca venom. DM43 also showed antilethal, antiedematogenic and
antihyperalgesic activities. None of the inhibitors showed enzymatic activity on
casein. Both proteins formed stable complexes with jararhagin and inhibited its
hemorrhagic effect as well as the enzymatic activity of this toxin on fluorogenic
substrate.
PMID- 10779683
TI - NADH-dependent decavanadate reductase, an alternative activity of NADP-specific
isocitrate dehydrogenase protein.
AB - The well known NADP-specific isocitrate dehydrogenase (IDH) obtained from pig
heart was found to oxidize NADH with accompanying consumption of oxygen
(NADH:O(2)=1:1) in presence of polyvanadate. This activity of the soluble IDH
protein has the following features common with the previously described membrane
enzymes: heat-sensitive, active only with NADH but not NADPH, increased rates in
acidic pH, dependence on concentrations of the enzyme, NADH, decavanadate and
metavanadate (the two constituents of polyvanadate), and sensitivity to SOD and
EDTA. Utilizing NADH as the electron source the IDH protein was able to reduce
decavanadate but not metavanadate. This reduced form of vanadyl (V(IV)) was
similar in its eight-band electron spin resonance spectrum to vanadyl sulfate but
had a 20-fold higher absorbance at its 700 nm peak. This decavanadate reductase
activity of the protein was sensitive to heat and was not inhibited by SOD and
EDTA. The IDH protein has the additional enzymic activity of NADH-dependent
decavanadate reductase and is an example of "one protein--many functions".
PMID- 10779684
TI - Enhancement of AA-amyloid formation in mice by transthyretin amyloid fragments
and polyethylene glycol.
AB - The mechanism behind amyloid formation is unknown in all types of amyloidosis.
Several substances can enhance amyloid formation in animal experiments. To induce
secondary systemic amyloid (AA-type amyloid) formation, we injected silver
nitrate into mice together with either amyloid fibrils obtained from patients
with familial polyneuropathy (FAP) type I or polyethylene glycol (PEG). Mice
injected with silver nitrate only served as controls. Amyloid deposits were
detectable at day 3 in animals injected with amyloid fibrils and in those
injected with PEG, whereas in control mice, deposits were not noted before day
12. Our results indicate that amyloid fibrils from FAP patients and even a non
sulfate containing polysaccharide (PEG) have the potential to act as amyloid
enhancing factors.
PMID- 10779685
TI - Spatiotemporal dynamics of fibrin formation and spreading of active thrombin
entering non-recalcified plasma by diffusion.
AB - The spatiotemporal dynamics of clot growth was studied in non-stirred non
recalcified plasma where thrombin entered by diffusion. Under these conditions,
the clot rapidly grew for 30-45 min and then stopped growing on reaching 0.4-0.5
mm in size. The dynamics of clot growth and its size almost did not depend on the
thrombin concentration in the range from 50 to 400 nM. FITC-thrombin was shown to
permeate the growing clot. The clot size in antithrombin-deficient plasma
increases with decreasing antithrombin concentration, being 1.5 mm in the plasma
depleted of antithrombin to 5% of its initial level. The data on the spatial
distribution of amidolytic activity in the growth zone of the clot suggested that
thrombin was not the sole source of this activity. Analysis showed that this
additional activity arising during thrombin diffusion into plasma was largely
accounted for by thrombin-alpha(2)-macroglobulin complex.
PMID- 10779686
TI - Modulation of glucan-binding protein activity in streptococci by fluoride.
AB - Glucan-binding lectin (GBL) activity of Streptococcus sobrinus was significantly
reduced by fluoride in the growth medium. Approximately 1.5 mM fluoride was
required for a 50% reduction in GBL activity. In addition to the GBL, several
other glucan-binding proteins were reduced when the bacteria were grown in
subinhibitory fluoride. Fluoride had no effect on glucosyltransferases (GTFs),
enzymes capable of converting sucrose into alpha-1,6-glucans. All the proteins
were detected by use of enhanced chemiluminescence (ECL of fluorescein-labeled
dextran) and Western blotting of renatured SDS-PAGE gels. The effects of fluoride
on the bacteria were abrogated when the manganous ion was included in the growth
medium. It thus appears that one mechanism of action of fluoridated water is its
effects on glucan-binding proteins. The fluoride may be reducing metabolism of
the mangano aquo ion, essential for expression of the glucan-binding proteins.
PMID- 10779687
TI - Importance of association between permeabilization and electrophoretic forces for
intramuscular DNA electrotransfer.
AB - Gene transfer using electrical pulses is a rapidly expanding field. Many studies
have been performed in vitro to elucidate the mechanism of DNA electrotransfer.
In vivo, the use of efficient procedures for DNA electrotransfer in tissues is
recent, and the question of the implied mechanisms is largely open. We have
evaluated the effects of various combinations of square wave electric pulses of
variable field strength and duration, on cell permeabilization and on DNA
transfection in the skeletal muscle in vivo. One high voltage pulse of 800 V/cm,
0.1 ms duration (short high pulse) or a series of four low voltage pulses of 80
V/cm, 83 ms duration (long low pulses) slightly amplified transfection efficacy,
while no significant permeabilization was detected using the (51)Cr-EDTA uptake
test. By contrast, the combination of one short high pulse followed by four long
low pulses led to optimal gene transfer efficiency, while inducing muscle fibers
permeabilization. These results are consistent with additive effects of
electropermeabilization and DNA electrophoresis on electrotransfer efficiency.
Finally, the described new combination, as compared to the previously reported
use of repeated identical pulses of intermediate voltage, leads to similar gene
transfer efficiency, while causing less permeabilization and thus being likely
less deleterious. Thus, combination of pulses of various strengths and durations
is a new procedure for skeletal muscle gene transfer that may represents a clear
improvement in view of further clinical development.
PMID- 10779688
TI - Inverting character of alpha-glucuronidase A from Aspergillus tubingensis.
AB - Alpha-glucuronidase A from Aspergillus tubingensis was found to be capable of
liberating 4-O-methyl-D-glucuronic acid (MeGlcA) only from those beechwood
glucuronoxylan fragments in which the acid is attached to the non-reducing
terminal xylopyranosyl residue. Reduced aldotetrauronic acid, 4-O-methyl-D
glucuronosyl-alpha-1,2-D-xylopyranosyl-beta-1,4-xylopyranosyl-beta-1,4-xylitol,
was found to be a suitable substrate to follow the stereochemical course of the
hydrolytic reaction catalyzed by the purified enzyme. The configuration of the
liberated MeGlcA was followed in a D(2)O reaction mixture by (1)H-NMR
spectroscopy. It was unambiguously established that MeGlcA was released from the
substrate as its beta-anomer from which the alpha-anomer was formed on
mutarotation. This result represents the first experimental evidence for the
inverting character of a microbial alpha-glucuronidase, a member of glycosyl
hydrolase family 67 (EC 3.1.1.139).
PMID- 10779689
TI - Redox properties of iron-dithiocarbamates and their nitrosyl derivatives:
implications for their use as traps of nitric oxide in biological systems.
AB - While the Fe(2+)-dithiocarbamate complexes have been commonly used as NO traps to
estimate NO production in biological systems, these complexes can undergo complex
redox chemistry. Characterization of this redox chemistry is of critical
importance for the use of this method as a quantitative assay of NO generation.
We observe that the commonly used Fe(2+) complexes of N-methyl-D-glucamine
dithiocarbamate (MGD) or diethyldithiocarbamate (DETC) are rapidly oxidized under
aerobic conditions to form Fe(3+) complexes. Following exposure to NO,
diamagnetic NO-Fe(3+) complexes are formed as demonstrated by the optical,
electron paramagnetic resonance and gamma-resonance spectroscopy,
chemiluminescence and electrochemical methods. Under anaerobic conditions the
aqueous NO-Fe(3+)-MGD and lipid soluble NO-Fe(2+)-DETC complexes gradually self
transform by reductive nitrosylation into paramagnetic NO-Fe(2+)-MGD complexes
with yield of up to 50% and the balance is converted to Fe(3+)-MGD and nitrite.
In dimethylsulfoxide this process is greatly accelerated. More efficient
transformation of NO-Fe(3+)-MGD into NO-Fe(2+)-MGD (60-90% levels) was observed
after addition of reducing equivalents such as ascorbate, hydroquinone or
cysteine or with addition of excess Fe(2+)-MGD. With isotope labeling of the NO
Fe(3+)-MGD with (57)Fe, it was shown that these complexes donate NO to Fe(2+)
MGD. NO-Fe(3+)-MGD complexes were also formed by reversible oxidation of NO
Fe(2+)-MGD in air. The stability of NO-Fe(3+)-MGD and NO-Fe(2+)-MGD complexes
increased with increasing the ratio of MGD to Fe. Thus, the iron-dithiocarbamate
complexes and their NO derivatives exhibit complex redox chemistry that should be
considered in their application for detection of NO in biological systems.
PMID- 10779690
TI - Copper-catalyzed autoxidations of GSH and L-ascorbic acid: mutual inhibition of
the respective oxidations by their coexistence.
AB - Glutathione (GSH) is known to inhibit copper-catalyzed autoxidation of L-ascorbic
acid (AA); in this study, AA was found to conversely inhibit copper-catalyzed
autoxidation of GSH. To elucidate the mechanism of the mutual inhibition of the
autoxidations of these two reducing substances in their coexistence, we have
kinetically investigated these phenomena. The study of the former phenomenon
revealed that GSH forms a 1:1 chelate with Cu(+) and thereby prevents the
autoxidation of AA. By the analysis of the latter phenomenon, it was postulated
that the inhibition of GSH oxidation by AA is due to rapid reduction of thiyl
radical of GSH by AA rather than competition of AA with GSH in the reduction of
Cu(2+). The effect of GSH on the formation of hydroxyl radical by the copper
catalyzed autoxidation of AA was also studied and it was found that the hydroxyl
radical formation was delayed dose-dependently by GSH with time lags comparable
to those of the oxidation of AA. Because there are several lines of evidence that
redox-active copper ions are released from tissues under pathological conditions,
it is possible that such copper ions coexist with AA and GSH in vivo, and in such
a situation, GSH may exert an inhibitory effect on the hydroxyl radical formation
caused by the autoxidation of AA.
PMID- 10779691
TI - Fast repair of dAMP radical anions by phenylpropanoid glycosides and their
analogs.
AB - Repair effect on 2'-deoxyadenosine-5'-monophosphate (dAMP) radical anions by
phenylpropanoid glycosides (PPGs) and their analogs, isolated from Chinese folk
medicinal herb, was studied using pulse radiolysis technique. The radical anion
of dAMP was formed by the reaction of hydrated electron with dAMP. On pulse
irradiation of nitrogen-saturated dAMP aqueous solution containing 0.2 M t-BuOH
and one of PPGs or their analogs, the transient absorption spectrum of the
radical anion of dAMP decayed with the formation of that of the radical anion of
PPGs or their analogs within several decades of microseconds after electron pulse
irradiation. The results indicated that dAMP radical anions can be repaired by
PPGs or their analogs. The rate constants of the repair reactions were deduced to
be 1.6-4.5 x 10(8) M(-1) s(-1).
PMID- 10779692
TI - Synthesis and secretion of selenoprotein P by cultured rat astrocytes.
AB - Selenoprotein P is an extracellular protein that has been postulated to have an
oxidant defense function. It has survival-promoting properties for cultured
neurons and its mRNA is present in the brain. This study sought to determine the
primary structure of rat brain selenoprotein P and to assess its production by
cultured brain cells. The cDNA of selenoprotein P was isolated from a rat brain
cDNA library and was found to encode the same peptide sequence as rat liver cDNA.
Thus the primary structure of brain selenoprotein P is the same as selenoprotein
P from liver. Astrocytes and a cerebellar granule cell preparation (CGC) were
obtained from rat brains and established in culture. The CGC was estimated to
contain up to 5% glial cells. Both preparations were shown to contain
selenoprotein P mRNA. During incubation with (75)Se-labeled selenite, both cell
preparations secreted a (75)Se-labeled protein into the medium that corresponded
in size to selenoprotein P. Also, the (75)Se-labeled protein could be
precipitated from both media with an antiserum to selenoprotein P. This shows
that astrocytes and the CGC secrete selenoprotein P. Selenoprotein P is made in
the brain and may have an oxidant defense function there.
PMID- 10779693
TI - Presence and inducibility of peroxisomes in a human glioblastoma cell line.
AB - We investigated the effect of the peroxisomal proliferator (PP) perfluorodecanoic
acid (PFDA), alone or in combination with 9-cis-retinoic acid (RX) on the human
glioblastoma cell line Lipari (LI). Cell proliferation, apoptotic rate,
peroxisome morphology and morphometry, peroxisomal enzyme activities and the
presence of peroxisome proliferator-activated receptors (PPARs) were examined. We
show that PFDA alone produces pleiotropic effects on LI cells and that RX
enhances some of these effects. Peroxisomal number and relative volume, as well
as palmitoyl-CoA oxidase activity and protein, are increased by PFDA treatment,
with a synergistic effect by RX. The latter, alone or in association with PFDA,
induces catalase activity and protein, increases apoptosis and decreases cell
proliferation. PPAR isotypes alpha and gamma were detected in LI cells. While the
former is apparently unaffected by either treatment, the latter increases in
response to PFDA, independent of the presence of RX. The results of this study
are discussed in terms of PPARalpha activation and PPARgamma induction by PFDA,
by either a direct or an indirect mechanism.
PMID- 10779694
TI - MUC-6 mucin is a major component of "blood group substance" from human ovarian
cyst fluid.
AB - Ovarian cyst fluid has been a valuable source of the mucins (traditionally termed
"blood group substances") that were used for the elucidation of the structures of
the ABO Lewis blood group determinants, but the identity of the mucin peptide
core(s) carrying these carbohydrate specificities is not known. An ovarian cyst
fluid mucin was purified, deglycosylated with HF and digested with trypsin or
chymotrypsin to yield a number of peptides. Amino acid sequencing of these
peptides yielded five different sequences which showed complete or partial
homology to the MUC-6 apomucin deduced from DNA sequencing. As no other sequences
were identified, it is concluded that MUC-6 is the major mucin core structure of
ovarian cyst fluid mucin.
PMID- 10779695
TI - The blood-nerve barrier: enzymes, transporters and receptors--a comparison with
the blood-brain barrier.
AB - The blood-brain barrier (BBB) has been much more extensively investigated than
the blood-nerve barrier (BNB). Nevertheless it is clear that there are both
similarities and differences in the molecular and morphophysiological
characteristics of the two barrier systems. A number of enzymes, transporters and
receptors have been investigated at both the BNB and BBB, as well as in the
perineurium of peripheral nerves, which is also a metabolically active diffusion
barrier. While there have been few systematic comparisons of the distribution of
these molecules in both the BNB and BBB, it is apparent from the data available,
reviewed in this article, that their distribution also supports the concept of
the BNB and BBB having some features in common but also showing distinct
identities. These similarities and differences cannot simply be accounted for by
the presence of the inductive influences of astrocytes at the BBB and absence at
the BNB. Whether the Schwann cell also has the capacity to induce some BNB
properties remains to be determined.
PMID- 10779696
TI - Long-term theophylline treatment changes the effects of angiotensin II and
adenosinergic agents on the seizure threshold.
AB - The effects of angiotensin II (ANG II), sarmesin, losartan, PD 123319, and
adenosine A (1) receptor agonist N(6)-cyclopentyladenosine (CPA) administered
i.c.v. in untreated and in theophylline-treated male mice (50 mg/kg i.p. twice
daily for 14 days) were studied on the pentylenetetrazol (PTZ) seizure threshold.
The threshold was increased after long-term theophylline treatment. ANG II,
sarmesin, and CPA increased the threshold in theophylline-untreated mice, whereas
it decreased the threshold in theophylline-treated animals. Losartan did not
change the threshold in theophylline-untreated mice but decreased it in
theophylline-treated animals. PD 123319 did not change the seizure threshold both
in theophylline-untreated and -treated mice. Taken together, the data
demonstrated that repeated exposure to theophylline selectively changes the
effects of ANG II and adenosinergic agents on the PTZ seizure threshold. The
results indicate that both angiotensin AT(1) and adenosine A(1) receptor subtypes
could possess interactive mechanisms of adaptation to chronic theophylline
treatment.
PMID- 10779698
TI - Clomethiazole protects against hemineglect in a primate model of stroke.
AB - Permanent occlusion of the M1 segment of the middle cerebral artery (pMCAO) in
the marmoset, a New World species of monkey, produces unilateral functional
deficits, including motor neglect with the contralesional arm and contralesional
spatial hemineglect. In this study we examined whether clomethiazole, a drug
which modulates the gamma-aminobutyric acid(A) receptor, reduced the severity of
the hemineglect and other deficits in this primate model of stroke. Nine monkeys
received pMCAO; 1 h later four of the nine were administered clomethiazole by
intraperitoneal injection and subcutaneous implantation of osmotic mini-pumps,
which released clomethiazole for 48 h. The monkeys had been trained and tested on
a number of behavioral tasks prior to surgery and were re-tested 3 and 10 weeks
later. Three weeks after pMCAO, monkeys treated with clomethiazole had a
significantly reduced degree of spatial neglect compared to untreated controls.
Clomethiazole was not effective against the severe contralesional motor
impairment in the current study, although it ameliorated a somewhat less severe
motor deficit in a previous study in which the more distal, M2 segment of the
middle cerebral artery had been occluded. Postmortem analysis of the brains
showed that clomethiazole treatment had significantly reduced the area of damage
in part of the parietal cortex. These data suggest that clomethiazole may reduce
the neglect that can be a debilitating consequence of right-sided stroke in man.
PMID- 10779697
TI - kappa-opioid agonist stimulated regional distribution of [(35)S]GTPgammas binding
in butorphanol continuously infused rat.
AB - Butorphanol is a mixed agonist/antagonist opioid analgesic agent, which exerts
its effects mainly by interaction with the kappa-opioid receptor. Opioid
receptors are coupled to G proteins of G(i)/G(o) family, and recently a decrease
in micro-opioid activation of G proteins has been reported in specific brainstem
nuclei after chronic morphine administration. The influence of centrally
administered butorphanol on agonist-stimulated G protein coupling was examined in
the rat brain, using in situ guanylyl-5'-O-(gamma-[(35)S]thio)-triphosphate
(GTPgammaS) binding autoradiography. Rats were treated with butorphanol (26
nmol/microl/h) by intracerebroventricular infusion via osmotic minipumps for 3
days. The distribution of [(35)S]GTPgammaS binding in the brain 7 h after the
termination of butorphanol infusion was measured in the presence or absence of
the selective kappa-opioid agonist, U-50,488. This agonist significantly
increased [(35)S]GTPgammaS binding in the parietal cortex, caudate putamen,
thalamus, and central gray of control rats, but not in those regions of the
butorphanol-infused animals. These results suggest that chronic administration of
butorphanol developed tolerance and abolished U-50,488 activation of G proteins
in these brain areas.
PMID- 10779699
TI - Peripheral NMDA and non-NMDA receptors contribute to nociception: an
electrophysiological study.
AB - The present study investigated the effects of peripheral administration of N
methy-D-aspartate (NMDA) and non-NMDA receptor antagonists on C-fiber evoked
responses of the spinal dorsal horn neurons in the spinalized rats. When DL-2
amino-5-phosphonovaleric acid (AP5) (10 mM, 1 mM, 0.1 mM, 20 microl) or 6, 7
dinitroquinoxaline-2, 3-dione (DNQX) (1 mM, 0.1 mM, 0.01 mM, 20 microl) was
subcutaneously injected into the receptive field on the hindplantar region, C
fiber evoked responses of the dorsal horn neurons were profoundly inhibited in a
dose-dependent manner. Three hours after subcutaneous injection of carrageenan
into the ipsilateral hindpaw, NMDA and non-NMDA antagonist-induced inhibition of
C-fiber evoked responses was more potent than that in the normal rat (Student's t
test, p < 0.05). In the carragenan-treated rats, DNQX-induced inhibition was
stronger than AP-5-induced one (Student's t-test, p < 0.05). The results suggest
that peripheral NMDA and non-NMDA receptors are involved in mediating excitation
of nociceptors.
PMID- 10779700
TI - Diminished central fatigue by inhibition of the L-system transporter for the
uptake of tryptophan.
AB - Nagase genetically analbuminemic rats (NAR) were run to fatigue. Administration
of branched chain amino acids (BCAA) before exhaustive exercise, resulted in a
post-fatigue decreased tryptophan uptake (-22%, p < 0.05) and 5-hydroxytryptophan
(5-HTP) uptake (-29%, p < 0.01) into the synaptosomes isolated from the striatum
when compared with saline administration. At the same time, NAR who received
either BCAA or 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH, a specific
inhibitor for the L-system transporter) had a considerably prolonged run time to
exhaustion (by twofold), compared to those who received either saline or albumin
treatments. When classified by run time, it was of interest that, when the data
for BCAA and BCH treatments for the longer run time NAR (Group B) was combined,
it gave rise to a significant decrease in synaptosomal tryptophan and 5-HTP of a
similar magnitude to that observed with BCAA alone. These levels were lower than
those observed in NAR in the shorter run time group (Group A) for all treatments.
These results support the view that an activated serotonergic function may be
involved in central fatigue, which can be diminished by inhibition of the L
system transporter.
PMID- 10779701
TI - Deramciclane inhibits N-methyl-D-aspartate receptor function.
AB - Effects of the novel anxiolytic drug deramciclane on excitatory amino acid
release and transmembrane Ca(2+) ion flux processes were compared in rat
cerebrocortical homogenates containing resealed plasmalemma fragments and nerve
endings. Deramciclane (10 microM) significantly inhibited [(3)H]D-aspartate
release and transmembrane Ca(2+) flux to N-methyl-D-aspartate in the absence of
Mg(2+). By contrast, inhibition of [(3)H]D-aspartate release and transmembrane
Ca(2+) flux evoked by 0.1 mM (S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazole
propionate in the presence of Mg(2+) and 10 microM cyclothiazide by 10 microM
deramciclane was not significant. In the presence of N-methyl-D-aspartate
receptor antagonists, deramciclane (10 microM) did not inhibit [(3)H]D-aspartate
release to N-methyl-D-aspartate. These results suggest an involvement of the
inhibition of a presynaptic N-methyl-D-aspartate receptor in the anxiolytic
properties of deramciclane.
PMID- 10779702
TI - Effects of the anion channel blocker DIDS on ouabain- and high K(+)-induced
release of amino acids from the rat cerebral cortex.
AB - Amino acid release from the rat cerebral cortex was analyzed using an in vivo
cortical cup perfusion model. Topical applications of ouabain or high
extracellular K(+) were used to mimic two dimensions of ischemic conditions which
promote cell swelling and amino acid release. Ouabain (30 microM) induced
significant releases of taurine, gamma-aminobutyric acid (GABA), aspartate,
glutamate and phosphoethanolamine. The anion channel blocker, 4, 4'
diisothiocyanatostilbene-2, 2'-disulfonic acid (DIDS; 1 mM), inhibited ouabain
induced release of all these amino acids except for glutamate. Exposure to high
extracellular K(+) (75 mM) induced a delayed rise in the levels of taurine in the
superfusates and an immediate increase in GABA levels. There were no significant
releases of other amino acids. The release of taurine and GABA was sensitive to
the blocking of anion channels with DIDS. Both ouabain- and high K(+)-induced
taurine release is likely to be mediated by DIDS sensitive anion channels. The
extracellular accumulation of the other amino acids, where insensitive to DIDS,
may be mediated by mechanisms other than swelling-induced anion channels.
PMID- 10779703
TI - Mice transgenic for the human Huntington's disease mutation have reduced
sensitivity to kainic acid toxicity.
AB - The mechanism underlying the pathology of Huntington's disease (HD) is unknown,
although there is substantial evidence supporting a role for excitotoxicity. The
discovery of abnormal aggregations of protein in the brains of patients with HD,
as well as in the brains of transgenic mice modeling this disease, has led to the
suggestion that these "inclusions" have a pathogenic role. However, the
relationship between inclusion formation and the progressive neurodegeneration in
HD remains unclear. Here, we used mice transgenic for the first exon of the HD
gene and an expanded CAG repeat (R6/2 line) to examine the role of neuronal
intranuclear inclusions in kainic acid (KA) excitotoxicity. Unexpectedly, we
found that the toxicity of KA was markedly attenuated in R6/2 mice compared with
wild-type mice. In particular, the number and severity of KA-induced seizures in
R6/2 mice was significantly reduced. When seizures occurred in 3-week-old R6/2
mice, we found lesions in the CA3 region of the hippocampus. However, neuronal
intranuclear inclusions were not induced by KA in 3-week-old mice. Further, in
older mice (9 weeks), the pre-existence of inclusions in CA3 neurons did not
increase the vulnerability of neurons to KA, since no lesions were seen in 9-week
R6/2 mouse brain. Our results suggest that an increased susceptibility to
excitotoxic stimuli does not underlie the early phase of the neurological
phenotype in R6/2 mice, although a role in later stages is not excluded by our
findings. The significance of these findings is discussed in the context of the
R6/2 mouse as a model for HD.
PMID- 10779704
TI - Interferon-gamma-responsive neuronal sites in the normal rat brain: receptor
protein distribution and cell activation revealed by Fos induction.
AB - Constitutive expression of the interferon-gamma receptor protein (IFN-gammaR),
and the distribution of cells in which Fos, a marker of cell activation, is
induced by intracerebroventricular administration of IFN-gamma, were studied in
the rat brain by immunohistochemistry. IFN-gammaR immunopositivity was found in
neuronal elements, which exhibited a selective distribution being concentrated in
the piriform and entorhinal cortex, midline thalamus and medial hypothalamic
structures, brainstem nociceptive relays (including the periaqueductal gray, the
parabrachial nuclei and the caudal part of the spinal trigeminal nuclei), and
circumventricular organs such as the median eminence and area postrema. IFN-gamma
induced Fos expression mostly corresponded to neuronal sites of receptor
distribution. Because of its topographical distribution, it is suggested that
activation of the IFN-gammaR in neurons may play a role to limit spread of
infections in the brain and, in concert with other proinflammatory cytokines, to
modulate adaptive responses to an antigen challenge mediated by the central
nervous system.
PMID- 10779705
TI - The biology of enhancer-dependent transcriptional regulation in bacteria:
insights from genome sequences.
AB - The bacterial transcription factor sigma(N) (sigma-N, sigma-54, RpoN) confers
upon RNA polymerase (RNAP) properties distinct from those of the major house
keeping form of RNAP, which contains sigma(70) (sigma-70, RpoD). Transcription by
RNAP containing sigma(N) is subject to enhancer-dependent regulation. Far from
being an 'oddity' or 'exception to the rule', the occurrence of sigma(N) in the
genome sequences of such diverse bacteria as Aquifex aeolicus, Bacillus subtilis,
Chlamydia spp. and Borrelia burgdorferi argues for its biological importance. The
availability of complete genome sequences of several (eu)bacteria offers an
opportunity to extend our understanding of this special form of transcriptional
regulation. By scanning their genome sequences, new functions have been predicted
for enhancer-dependent transcription in A. aeolicus, Chlamydia trachomatis,
Escherichia coli, Treponema pallidum and B. burgdorferi.
PMID- 10779706
TI - Osmoregulated periplasmic glucans in Proteobacteria.
AB - Large amounts of osmoregulated periplasmic glucans (OPGs) are found in the
periplasmic space of Proteobacteria. Four families of OPGs are described on the
basis of structural features of the polyglucose backbone. Depending on the
species considered, OPGs can be modified to various extent by a variety of
substituents. Genes governing the backbone synthesis are identified in a limited
number of species. They belong to three unrelated families. OPG synthesis is
subject to osmoregulation and feedback control. Osmoregulation can occur at the
level of gene expression and/or at the level of enzyme activity. Mutants
defective in OPG synthesis have a highly pleiotropic phenotype, indicative of an
overall alteration of their envelope properties. Mutants of this kind were
obtained as attenuated or avirulent derivatives of plant or animals pathogen.
Thus, OPGs appear to be important intrinsic components of the Gram-negative
bacterial envelope, which can be essential in extreme conditions found in nature,
and especially when bacteria must interact with an eukaryotic host.
PMID- 10779708
TI - Biodegradation of diethyl phthalate in soil by a novel pathway.
AB - Biodegradation of diethyl phthalate (DEP) has been shown to occur as a series of
sequential steps common to the degradation of all phthalates. Primary degradation
of DEP to phthalic acid (PA) has been reported to involve the hydrolysis of each
of the two diethyl chains of the phthalate to produce the monoester monoethyl
phthalate (MEP) and then PA. However, in soil co-contaminated with DEP and MeOH,
biodegradation of the phthalate to PA resulted in the formation of three
compounds, in addition to MEP. These were characterised by gas chromatography
electron ionisation mass spectrometry and nuclear magnetic resonance as ethyl
methyl phthalate, dimethyl phthalate and monomethyl phthalate, and indicated the
existence of an alternative pathway for the degradation of DEP in soil co
contaminated with MeOH. Transesterification or demethylation were proposed as the
mechanisms for the formation of the three compounds, although the 7:1 ratio of
H(2)O to MeOH means that transesterification is unlikely.
PMID- 10779707
TI - Isolation and characterization of alkane-utilizing Nocardioides sp. strain CF8.
AB - A butane-utilizing bacterial strain CF8 was isolated and identified as a member
of the genus Nocardioides from chemotaxonomic and 16S rDNA sequence analysis.
Strain CF8 grew on alkanes ranging from C(2) to C(16) in addition to butane and
various other substrates including primary alcohols, carboxylic acids, and
phenol. Butane degradation by strain CF8 was inactivated by light, a specific
inactivator of copper-containing monooxygenases. The unique thermal aggregation
phenomenon of acetylene-binding polypeptides was also observed for strain CF8.
These results suggest that butane monooxygenase in strain CF8 is a third example
of the copper-containing monooxygenases previously described in ammonia oxidizers
and methanotrophs.
PMID- 10779709
TI - Specific binding of recombinant Listeria monocytogenes p60 protein to Caco-2
cells.
AB - The Listeria monocytogenes p60 is a major extracellular protein, which is
believed to be involved in the invasion of these bacteria into their host cells.
So far the mechanism by which p60 participates in the internalization or
penetration of L. monocytogenes is still veiled. To determine the possibility of
a direct interaction of p60 with the host cell surface, the iap gene was
recombinantly expressed in Escherichia coli and used for binding studies with the
enterocyte-like Caco-2 cells. Fluorescence activated flow cytometry and confocal
laser scanning microscopy revealed a cell membrane specific staining with p60,
which implications in Listeria virulence are discussed.
PMID- 10779710
TI - Characterization of the desulforubidin operons from Desulfobacter vibrioformis
and Desulfobulbus rhabdoformis.
AB - The genes encoding the desulforubidin type of dissimilatory sulfite reductase
(Dsr) from the sulfate-reducing bacteria Desulfobacter vibrioformis and
Desulfobulbus rhabdoformis were cloned and sequenced. Similar to the genes for
dissimilatory sulfite reductase from the genera Archaeoglobus, Desulfovibrio and
Desulfotomaculum the dsr genes were found to form an operon, dsrABD, where dsrA
and dsrB encode the structural subunits, alpha and beta, of Dsr, respectively.
dsrD encodes a conserved unknown protein apparently restricted to sulfate
reducing species. In Desulfobacter vibrioformis a fourth gene, designated dsrN,
was found downstream of dsrD forming a contiguous operon, dsrABDN. DsrN showed
significant sequence homology to cobyrinic a,c-diamide synthase, which is
involved in the biosynthesis of vitamin B12. A function for DsrN in amidation of
siroheme is likely. Analysis of the dsrAB-encoded proteins confirmed that the
high conservation observed for other types of dissimilatory sulfite reductase is
also found in desulforubidin. The use of Dsr sequences in unravelling the
phylogeny of sulfate-reducing bacteria is discussed.
PMID- 10779711
TI - Identification of a putative LPS-associated cation exporter from Rhizobium
leguminosarum bv. viciae.
AB - A gene, cpaA, with similarity to calcium proton antiporters has been identified
adjacent to lpcAB in Rhizobium leguminosarum. LpcA is a galactosyl transferase
while LpcB is a 2-keto-3-deoxyoctonate transferase, both of which are required to
form the lipopolysaccharide (LPS) core in R. leguminosarum. Mutations in lpcAB
result in a rough LPS phenotype with a requirement for elevated calcium
concentrations to allow growth, suggesting that truncation of the LPS core
exposes a highly negatively charged molecule. This is consistent with the LPS
core being one of the main sites for binding calcium in the Gram-negative outer
membrane. Strain RU1109 (cpaA::Tn5-lacZ) has a normal LPS layer, as measured by
silver staining and Western blotting. This indicates that cpaA mutants are not
grossly affected in their LPS layer. LacZ fusion analysis indicates that cpaA is
constitutively expressed and is not directly regulated by the calcium
concentration. Over-expression of cpaA increased the concentration of calcium
required for growth, consistent with CpaA mediating calcium export from the
cytosol. The location of lpcA, lpcB and cpaA as well as the phenotype of lpcB
mutants suggests that CpaA might provide a specific export pathway for calcium to
the LPS core.
PMID- 10779712
TI - Transposon targeting determined by resolvase.
AB - The Mu-related transposon Tn5090, also called Tn402, was observed to be highly
selective for targets clustered in or close to recombination sites of serine-type
recombinases in plasmids R388 and RP1. Transposition to the par area of RP1
responded strongly to a deletion in the gene of resolvase ParA. A search in
sequence databanks revealed further insertions of Tn5090/Tn402 close to different
genes of resolvases. These results imply that the target selection of Tn5090
depends on a property that is shared among several serine recombinases.
PMID- 10779713
TI - Insertional inactivation of mtrX and mtrY genes from the mithramycin gene cluster
affects production and growth of the producer organism Streptomyces argillaceus.
AB - Mithramycin is an antitumor aromatic polyketide synthesized by Streptomyces
argillaceus. Two genes (mtrX and mtrY) of the mithramycin gene cluster were
inactivated by gene replacement. Inactivation of mtrX, that encodes an ABC
excision nuclease system for DNA repair, produced a mutant that was affected in
the normal rate of growth. Expression of mtrX in Streptomyces albus in a
multicopy plasmid vector conferred a low increase in resistance to mithramycin.
Inactivation of mtrY, that encodes a protein of unknown function, produced a 50%
decrease in mithramycin biosynthesis. When mtrY was expressed in the wild-type S.
argillaceus in a multicopy plasmid, this caused about 47% increase in the levels
of mithramycin production. It is proposed that mtrX and mtrY could code for a
secondary defense mechanism and a mithramycin regulatory element, respectively.
PMID- 10779714
TI - Cloning and expression of an alpha-amylase encoding gene from the
hyperthermophilic archaebacterium Thermococcus hydrothermalis and biochemical
characterisation of the recombinant enzyme.
AB - An alpha-amylase encoding gene from the extremely thermophilic Archaea
Thermococcus hydrothermalis was cloned and expressed in Escherichia coli. The
encoded alpha-amylase possesses molecular characteristics specific to the
Archaea, especially from Pyrococcus species, with biochemical characteristics of
the alpha-amylases from Thermococcus. The gene is 1374 bp long and encodes a
protein of 457 amino acids composed of a 22 amino acid putative signal peptide
and a 435 amino acid mature protein (calculated molecular mass 49236 Da). The T.
hydrothermalis recombinant alpha-amylase is optimally active at 75-85 degrees C
and at pH 5.0-5.5.
PMID- 10779715
TI - FnrP interactions with the Pasteurella haemolytica leukotoxin promoter.
AB - Pasteurella haemolytica FnrP is homologous to Fnr, the global transcriptional
regulator of anaerobic respiration in Escherichia coli. To investigate the role
of O(2) in the expression of P. haemolytica leukotoxin, we tested a lktC::lacZ
fusion constructed in E. coli for a FnrP-mediated regulatory effect under aerobic
and anaerobic growth conditions. Both E. coli Fnr and FnrP suppressed leukotoxin
transcription under aerobic conditions. Under anaerobic conditions, Fnr
suppressed transcription, while FnrP increased transcription. These results were
confirmed using FnrP*, a mutant form of FnrP that activates anaerobically
inducible genes under aerobic conditions. In mobility shift assays, partially
purified FnrP bound to a potential regulatory site in a P. haemolytica lktC
promoter fragment.
PMID- 10779716
TI - A sensitive microsphere coagulation ELISA for Escherichia coli O157:H7 using
Russell's viper venom.
AB - A microsphere coagulation enzyme-linked immunosorbent assay (MC-ELISA) using
Russell's viper venom factor X activator (RVV-XA) is described for the detection
of Escherichia coli O157:H7. This microtitre plate assay comprises a standard
sandwich immunoassay incorporating RVV-XA as the enzyme label. Coagulation
substrate together with polystyrene microspheres are added to the wells of the
microtitre plate. RVV-XA initiates the coagulation cascade causing formation of
an artificial clot of polystyrene microspheres bound together with fibrin. As few
as 10(2) E. coli O157 in a well (10(3) per ml) can be detected within 3 h. The
assay is two orders of magnitude more sensitive than a standard ELISA and is a
generic technique with the potential for widespread use in sandwich immunoassays.
PMID- 10779717
TI - Interactions between type III secretion apparatus components from Yersinia pestis
detected using the yeast two-hybrid system.
AB - Interactions among the Yersinia secretion (Ysc) proteins of Yersinia pestis were
explored using the yeast two-hybrid system. Various pairwise combinations of the
yscEFGHIKLN and Q genes fused to the DNA-binding or activation domain of the
yeast GAL4 gene were introduced into yeast, and expression of a reporter gene
encoding beta-galactosidase was detected. Combinations of yscN and yscL, yscL and
yscQ, and yscQ and yscK resulted in high levels of reporter gene activation.
These results suggest that YscL interacts with both YscN and YscQ, and that YscQ
interacts with both YscL and YscK. Three-hybrid analyses using plasmid pDELA to
target a third hybrid protein to the yeast nucleus was used to detect the
formation of ternary protein complexes. Using the three-hybrid system, YscQ
expressed from plasmid pDELA was able to bring together the YscK and YscL fusion
proteins. In a similar manner, YscL expressed from plasmid pDELA was able to
bring together the YscN and YscQ fusion proteins. Together, these results suggest
that a complex composed of YscN, YscQ, YscK and YscL is involved in the assembly
and/or function of the Y. pestis type III secretion apparatus.
PMID- 10779718
TI - Enhancement of in vitro growth and resistance to gray mould of Vitis vinifera co
cultured with plant growth-promoting rhizobacteria.
AB - The potential of a plant growth-promoting rhizobacterium, Pseudomonas sp. (strain
PsJN), to stimulate the growth and enhancement of the resistance of grapevine
(Vitis vinifera L.) transplants to gray mould caused by Botrytis cinerea has been
investigated. In vitro inoculation of grapevine plantlets induced a significant
plant growth promotion which made them more hardy and vigorous when compared to
non-inoculated plantlets. This ability increased upon transplanting. When grown
together with B. cinerea, the causal agent of gray mould, significant differences
of aggressiveness were observed between the inoculated and non-inoculated plants.
The presence of bacteria was accompanied by an induction of plant resistance to
the pathogen. The beneficial effect from this plant-microbe association is being
postulated.
PMID- 10779719
TI - Cloning, functional expression and partial characterization of the glucose kinase
from Renibacterium salmoninarum.
AB - The complete glcK gene from the fish pathogen Renibacterium salmoninarum,
encoding a glucose kinase, was analyzed and expressed. The partial
characterization of the recombinant enzyme confirmed that it belongs to a group
of glucose kinases involved in carbon catabolite repression. Multiple sequence
alignments were used to deduce a new consensus sequence for this family of
bacterial proteins, characterized by several conserved Cys residues. This
sequence was more specific and allowed the detection of the first eukaryotic
protein of this family. The recombinant enzyme was inhibited by N-ethylmaleimide
and the substrates protected the enzyme from this inhibition, suggesting the
presence of Cys residues in or close to the active site.
PMID- 10779720
TI - Characterisation of the activator effect of glycogen on amylosucrase from
Neisseria polysaccharea.
AB - Amylosucrase produces an insoluble alpha-1,4-linked glucan from sucrose,
releasing fructose. In addition to polymerisation, in the presence of sucrose as
sole substrate, amylosucrase catalyses sucrose hydrolysis and oligosaccharide
synthesis in significant proportions. The effects of both glycogen acceptor and
sucrose concentrations on the reactions catalysed by the highly purified
amylosucrase from Neisseria polysaccharea were investigated. Sucrose hydrolysis
decreased strongly with the increase of the concentration of glycogen, as did
oligosaccharide synthesis, by glucose transfer onto glucose and fructose. The
glucosyl units consumed were then preferentially used for elongation of glycogen
chains. The study of the kinetic behaviour of amylosucrase revealed a strong,
sucrose concentration dependent activator effect of glycogen. This activation was
decreased at high sucrose concentration. The optimal sucrose concentrations
increased with glycogen concentration, suggesting competition between sucrose and
glycogen, and the presence of a second non-catalytic acceptor binding site which
could bind various acceptors (glucose, maltose, glycogen) and also sucrose.
PMID- 10779721
TI - Identification of intermediates of in vivo trichloroethylene oxidation by the
membrane-associated methane monooxygenase.
AB - The rate and products of trichloroethylene (TCE) oxidation by Methylomicrobium
album BG8 expressing membrane-associated methane monooxygenase (pMMO) were
determined using 14C radiotracer techniques. [(14)C]TCE was degraded at a rate of
1.24 nmol (min mg protein)(-1) with the initial production of glyoxylate and then
formate. Radiolabeled CO(2) was also found after incubating M. album BG8 for 5 h
with [(14)C]TCE. Experiments with purified pMMO from Methylococcus capsulatus
Bath showed that TCE could be mineralized to CO(2) by pMMO. Oxygen uptake studies
verified that M. album BG8 could oxidize glyoxylate and that pMMO was responsible
for the oxidation based on acetylene inactivation studies. Here we propose a
pathway of TCE oxidation by pMMO-expressing cells in which TCE is first converted
to TCE-epoxide. The epoxide then spontaneously undergoes HCl elimination to form
glyoxylate which can be further oxidized by pMMO to formate and CO(2).
PMID- 10779722
TI - Resuscitation of viable but nonculturable cells of Vibrio parahaemolyticus
induced at low temperature under starvation.
AB - Vibrio parahaemolyticus is known to exist in a viable but nonculturable state
when incubated at low temperature under starvation. It has long been debated
whether the culturable cells which appear after temperature upshift are the
result of true resuscitation or regrowth of a few residual culturable cells.
Starved V. parahaemolyticus cells at 4 degrees C reached the nonculturable stage
in about 12 days. The true resuscitation of nonculturable cells of V.
parahaemolyticus occurred after spreading them onto an agar medium supplemented
with H(2)O(2)-degrading compounds such as catalase or sodium pyruvate. The
proposed method may be applicable to detecting the enteropathogen from
environmental samples.
PMID- 10779723
TI - Reduced host resistance and Th1 response to Cryptococcus neoformans in
interleukin-18 deficient mice.
AB - Using interleukin (IL)-18 deficient (IL-18(-/-)) mice, we examined the role of IL
18 in the host resistance and Th1 response against infection with Cryptococcus
neoformans. Fungal clearance in the lung was reduced in IL-18(-/-) mice, although
there was no significant change in the level of dissemination to the brain. The
DTH response, as determined by footpad swelling, was also diminished in IL-18(-/
) mice compared to control wild-type (WT) mice. The levels of IL-12 and
interferon (IFN)-gamma in the sera were significantly lower in IL-18(-/-) mice
than in WT mice. Spleen cells from infected WT mice produced a high level of IFN
gamma upon stimulation with the microbe, while only a low level of IFN-gamma
production was detected in spleen cells from infected IL-18(-/-) mice.
Administration of IL-18 almost completely restored the reduced response in IL-18(
/-) mice, while IL-12 showed a marginal effect. These results demonstrated the
important role of IL-18 in the resistance and Th1 response of mice to C.
neoformans by potentiating the production of IFN-gamma.
PMID- 10779724
TI - Physiology and continuous culture of the hyperthermophilic deep-sea vent archaeon
Pyrococcus abyssi ST549.
AB - The deep-sea vent archaeon Pyrococcus abyssi strain ST549 was grown in batch
cultures in closed bottles and by continuous culture in a gas-lift bioreactor,
both in the presence and in the absence of elemental sulfur. Growth on
carbohydrates, proteinaceous substrates and amino acids was investigated. The
disaccharides maltose and cellobiose were shown not to be able to enhance growth
suggesting that P. abyssi ST549 is unable to use them as carbon sources. By
contrast, proteinaceous substrates such as peptone and brain heart infusion were
shown to be very good substrates for the growth of P. abyssi ST549 and allowed
growth at high steady-state cell densities in continuous culture. Growth on brain
heart infusion was shown to require additional nutrients when sulfur was not
present in the culture medium. Growth on amino acids only took place in the
presence of sulfur. These results indicate that sulfur plays an important role in
the metabolism and energetics of P. abyssi ST549.
PMID- 10779726
TI - Who determines our trajectory beyond the year 2000 - you do
PMID- 10779725
TI - A consensus Porphyromonas gingivalis promoter sequence.
AB - We have determined the transcription start points (tsp) for recently identified
Porphyromonas gingivalis W50 genes, kgp, rgpA, rgpB (formerly designated prtK,
prtR, and prtRII respectively), fetB and the mcmAB operon. Alignment of the DNA
upstream of these tsp and those from the literature has enabled us to identify
consensus sequences that may represent a P. gingivalis promoter. There is a
potential -10 hexamer sequence, 5'-TATATT-3' centred on average at -10/11 nt
which is repeated at -19/20 nt and an upstream consensus, 5'-CAGAT(A/G)-3' which
is centred at -39/40 nt.
PMID- 10779728
TI - The physiological state of captive and migrating Great White Pelicans (Pelecanus
onocrotalus) revealed by their blood chemistry.
AB - The Great White Pelican Pelecanus onocrotalus is an endangered migratory bird,
threatened by diminishing natural feeding sites and by persecution by fishermen.
The majority of the migrating White Pelican (71000) stop-over in Israel during
their autumn migration to Africa. As part of a larger study, aimed to assess the
necessity of feeding during the stop-over in Israel, we examined the blood
chemistry of captive and migrating White Pelicans. Blood was sampled from captive
birds maintained on a fish diet, after food deprivation for 48 h and from wild
birds brought from the field during migration. Food deprivation resulted in
increased plasma levels of triglycerides and in lower levels of urea, potassium
and calcium. In migrating birds, increased plasma levels of urea and CPK and
lower levels of creatinine were revealed. In general, the coefficient of
variation in the blood chemistry of migrating pelicans was higher than in the
captive birds, that is to say, that these birds were in a variable physiological
condition. The blood profile of migrating and wintering pelicans did not indicate
a state of dehydration but did indicate energy deficiency. The less extreme
changes in blood chemistry of the 48 h food-deprived compared to migrating
pelicans suggest that the former did not reach a state of starvation. We conclude
that for White Pelicans the stop-over in Israel is a must in order to rest and
replenish their fuel reserves for completion of their autumn migration to Africa.
PMID- 10779727
TI - Dietary modulation of intestinal enzymes of the house sparrow (Passer
domesticus): testing an adaptive hypothesis.
AB - Insectivorous/frugivorous passerine species studied so far lack the ability to
modulate intestinal maltase activity, in contrast to galliformes. We tested for
dietary modulation of small intestine (SI) enzymes including maltase in house
sparrows to understand whether the difference between the galliformes on the one
hand, and the passerines on the other, reflects a phylogenetic pattern (maltase
modulated in galliformes but not passerines), a dietary pattern (maltase
modulated in granivores but not insectivore/frugivores), some other pattern, or
chance. We also tested the prediction that intestinal peptidase activity would be
increased on a high protein (HP) diet. Birds were fed three diets high in starch,
protein, or lipid for 10 days. For birds on the HP diet (60.3% protein) we
observed the predicted upward modulation of aminopeptidase-N activity, as
compared with the lower-protein, high starch (HS) (12.8% protein) diet. In
contrast, birds eating the HS diet had similar maltase and sucrase activities,
and only slightly higher isomaltase activity, compared with birds eating the high
protein (HP), starch-free diet. Birds eating high lipid (HL) diet had low
activities of both carbohydrases and peptidase. Considering that the statistical
power of our tests was adequate, we conclude that house sparrows show little or
no increase in carbohydrases in response to elevated dietary carbohydrate. We
cannot reject the hypothesis that maltase lability among avian species has a
phylogenetic component, or that high dietary fat has a depressing effect on both
carbohydrase and peptidase activities.
PMID- 10779729
TI - Gizzard myoglobin contents and feeding habits in avian species.
AB - In an attempt to consider physiological function of myoglobin (Mb), we determined
Mb contents of gizzard smooth muscles with special reference to feeding habits in
85 avian species of 19 orders. The Mb content in 44 species of herbivorous birds
was 7.52+/-3.81 mg/g wet muscle, which was significantly higher than the value of
2.34+/-1.74 mg/g in 41 species of carnivorous ones (P<0.001). Buffering capacity,
as determined by in vitro titration method, was 37.3+/-5.5 slykes/g in gizzard
smooth muscles of 75 species and 60.7+/-10.5 slykes in breast skeletal muscles of
77 species (P<0.001), which suggests a significantly higher dependence, almost
comparable to cardiac muscles, of the gizzard muscular function on aerobic
metabolism. Together with the fact that blood circulation in the gizzard is very
low at resting, and might be further limited during activity, we conclude that
the higher Mb content in gizzards of herbivorous birds is an adaptation, to allow
storage and/or facilitated diffusion of oxygen, during process of high mechanical
work required to grind down hard and fibrous vegetable food under the conditions
of limited circulatory supply.
PMID- 10779730
TI - Developmental changes in organic osmolytes in prenatal and postnatal rat tissues.
AB - At high osmotic pressures, mammalian kidney medulla, heart, lens, and brain
utilize organic osmolytes to regulate cell volume. However the types and
proportions of these solutes vary among tissues in patterns and for non-osmotic
roles not fully elucidated. To clarify these, we analyzed osmolyte-type solute
contents in rat tissues at 7 and 2 days prenatal and at 0, 7, 14, 21 (weaning),
35 (juvenile) and 77 (adult) days postnatal. Placentas were dominated by betaine,
taurine, and creatine, which decreased between the prenatal times. Fetuses were
dominated by glutamate and taurine, which increased between the times. In
cerebrum, hindbrain and diencephalon, taurine dominated at early stages, but
dropped after postnatal day 7, while myo-inositol, glutamine, creatine and
glutamate increased after birth, with the latter two dominating in adults. In
olfactory bulb, taurine content declined gradually with age and was equal to
glutamate in adults. In all brain regions, glycerophosphorylcholine (GPC) reached
a peak in juveniles. In postnatal renal medulla, urea, sodium, GPC, betaine, and
taurine increased sharply at day 21. Thereafter, most increased, but taurine
decreased. In heart, taurine dominated, and increased with age along with
creatine and glutamine, while glutamate decreased after postnatal day 7. In lens,
taurine dominated and declined in adults. These patterns are discussed in light
of hypotheses on non-osmotic and pathological roles of these solutes.
PMID- 10779731
TI - Regional hypoxia elicits regional changes in chorioallantoic membrane vascular
density in alligator but not chicken embryos.
AB - Hypoxic incubation increases vascularization in the chick chorioallantoic
membrane (CAM). The effect of regional hypoxia on the vascular density of
American alligator (Alligator mississippiensis) and chicken (Gallus gallus) CAMs
was studied to determine if hypoxic proliferation of blood vessels is localized
or global across the CAM. Eggs were incubated under normoxic conditions with a
portion of the eggshell covered with non-toxic beeswax to induce external
regional hypoxia. CAMs were examined under a microscope with a 'bulls eye'
coverslip and a vascular density index (VDI) was determined. The hypoxic portions
of the alligator CAMs were more vascular than the normoxic portions (VDI = 200.9
versus 157. 8, respectively). Presumably this response is maladaptive by causing
increased blood flow to the poorly oxygenated portions, i.e. increased 'shunt'.
Thus, we hypothesize increased vascularity due to hypoxic incubation is due to
local release and subsequent rapid local breakdown or uptake of angiogenic
factors. In contrast, the hypoxic and normoxic portions of the chick CAMs
exhibited virtually no difference in VDI (VDI= 211.5 versus 217.9, respectively).
We suggest the air cell and air space of the chicken eggs allows for circulation
of gas in ovo, eliminating the possibility of regional internal hypoxia.
PMID- 10779732
TI - The role of beta-adrenergic receptors in the cutaneous water evaporation
mechanism in the heat-acclimated pigeon (Columba livia).
AB - The effects of selective and non-selective beta-adrenergic agents on cutaneous
water evaporation (CWE) were studied in hand-reared rock pigeons (Columba livia).
CWE was measured by the vapor diffusive resistance method, using a transient
porometer. Intramuscular and subcutaneous injections of a non-selective beta
adrenergic antagonist (propranolol) or a selective beta(2)-adrenergic antagonist
(ICI-118551) to heat-acclimated (HAc) pigeons at ambient temperature (T(a)) of 24
degrees C resulted in intensive CWE. The CWE values that were triggered by
propranolol and ICI-118551 (18.59+/-0.73 and 16.48+/-0.70 mg cm(-2) h(-1),
respectively) were close to those induced by heat exposure (17.62+/-1.40 mg cm(
2) h(-1)). Subcutaneous administration of propranolol produced local response.
Intramuscular injection of salbutamol (selective beta(2)-adrenergic agonist) to
HAc pigeons drastically diminished CWE induced by either propranolol, metoprolol
or heat exposure. Such manipulations also enhanced panting at relatively low
T(a)s (42 degrees C). The inhibition of beta(1)-adrenergic receptors by
metoprolol increased CWE, while inhibition by atenolol produced no change from
basal values. This difference may be attributed to their distinctive nature in
penetrating the blood-brain barrier. Our findings indicate a regulatory pathway
for CWE consisting of both beta(1)- and beta(2)-adrenergic receptors. We suggest
that the beta(1)-adrenergic effect is restricted mainly to the CNS, while the
beta(2)-adrenergic effect takes place at the effector level. We postulate this
level to be either the cutaneous microvasculature or the epidermal layer.
PMID- 10779733
TI - Spectral imaging of red blood cells in experimental anemia of Cyprinus carpio.
AB - In the present work we have studied the effect of experimental anemia induced at
both low and optimal temperatures on erythropoiesis in Cyprinus carpio. The
results showed that hemoglobin concentration per cell was similar in both
temperature conditions, however, red blood cell (RBC) concentration was higher at
the optimal temperature. Induced anemia caused an abrupt decrease in RBC
concentration, while the hemoglobin concentration per cell remained unchanged.
Recovery, as shown by electron microscopy, was characterized by the release of
differentiating young and intermediate cells to the peripheral blood. It was
revealed that with the progression of differentiation the nucleus/cytoplasm ratio
decreases, the chromatin condenses and the shape of the nucleus changes from
round to elliptical. Spectral imaging revealed an increase in the optical density
of chromatin with the maturation of the cells. The chromatin that was dispersed
over the nuclear volume in the young cells becomes highly ordered in the mature
cells. Spectral similarity mapping revealed the formation of a novel structure of
high symmetry, representing chromatin rearrangement during the process of
cellular differentiation.
PMID- 10779734
TI - The effect of short term confinement stress on binding characteristics of sex
steroid binding protein (SBP) in female black bream (Acanthopagrus butcheri) and
rainbow trout (Oncorhynchus mykiss).
AB - The effect of short term confinement stress on sex steroid binding protein (SBP)
binding characteristics was examined in female black bream (Acanthopagrus
butcheri), and rainbow trout (Oncorhynchus mykiss). Black bream were sampled
immediately after capture from the wild and again after 1, 6 or 24 h confinement.
Rainbow trout were sampled before and after 5 h confinement. Confinement of black
bream for 6 h after capture significantly reduced the binding capacity of SBP.
Binding affinity also tended to be lower after confinement. There were no
differences in binding affinity or capacity of black bream SBP after 1 or 24 h
confinement, or rainbow trout SBP after 5 h confinement. Plasma from rainbow
trout at 3 and 6 h after treatment with cortisol was compared to plasma from
saline-injected controls. No significant differences in binding characteristics
were detected, but there was a trend of decreased binding capacity in cortisol
injected fish compared to controls at 6 h post-injection. Relative binding
studies indicated that plasma cortisol at concentrations 100x or more greater
than plasma estradiol (E(2)) may displace E(2) from SBP in black bream, and act
to reduce circulating levels of E(2) through increased clearance of free steroid.
Physiological levels of cortisol did not displace E(2) from SBP in trout. The
observed changes in SBP and the competition of physiological concentrations of
cortisol for SBP binding sites may generate a component of the stress-induced
falls in plasma levels of E(2) reported across a range of species.
PMID- 10779735
TI - Purification and characterization of epidermis-origin hemolymph protein in
Galleria mellonella.
AB - Epidermis-origin hemolymph protein (EOHP) was identified and purified from the
last instar larval hemolymph of Galleria mellonella by anion exchange
chromatography, chromatofocusing chromatography, and Sephadex G-100. The EOHP has
a native molecular mass of 47 kDa and is composed of one subunit. The isoelectric
point of the EOHP was determined to be 5.3. The amino acid composition of the
EOHP was rich in aspartic acid, glutamic acid and lysine, but poor in tyrosine,
methionine, and tryptophan. EOHP is present in hemolymph over the period from the
4th instar larvae to the adult stage examined. Concentration of EOHP is high
during the larval stage but gradually decreased during the developmental stage
from pupal to adult stage. EOHP is present in the cuticle, fat bodies and trachea
but not in hemocytes, fore gut, mid gut and hind gut.
PMID- 10779736
TI - Carotenoid and retinoid--two pigments in a gecko eye lens.
AB - The eye lenses of the Moroccan day gecko Quedenfeldtia trachyblepharus contain
two different pigments: a retinoid (minor pigment) and a carotenoid (major
pigment). The retinoid, all-trans 3, 4-didehydroretinol, is bound to iota
crystallin, which comprises only 2% of the total amount of crystallins. The
carotenoid is associated to gammas-crystallin - comprising about 10% of total
amount of crystallins--and causes the dark yellow colour of the lens. The
absorption spectrum of the isolated carotenoid shows a major, triple-peaked band
at 372, 392, and 416 nm and two minor peaks at 284 and 294 nm. This spectrum
reminds of that of galloxanthin, a carotenoid found in oil droplets of some avian
retinae. The absorption spectrum of the carotenoid-gammas-crystallin complex is
shifted 6-8 nm bathochromically. In the lens, this complex absorbs ultraviolet
and shortwave blue radiation, supposedly improving the optical quality of the
dioptric apparatus and protecting the retina against photodamage. Both the
retinoid and the carotenoid are present in eye cups. The lenticular carotenoid of
Quedenfeldtia is the first example of a carotenoid in the lens of a terrestrial
vertebrate with a sufficiently high concentration to be physiologically effective
as a UV-filter. Additionally, it is unique in being the first example of a
carotenoid associated with gammas-crystallin.
PMID- 10779737
TI - Coagulation and fibrinolysis in capybara (Hydrochaeris hydrochaeris), a close
relative of the guinea-pig (Cavia porcellus).
AB - Fibrinolytic and coagulation properties of capybara (Hydrochaeris hydrochaeris,
LINNAEUS, 1766) plasma were analysed and the results compared to the guinea-pig
(Cavia porcellus), a close relative. Capybara fibrinogen was isolated and
fibrinolysis of its plasma was carried out in a homologous system and with bovine
fibrin. Undiluted plasma did not have fibrinolytic activity on fibrin plates;
euglobulins gave a dose-related response. Zymography of capybara and guinea-pig
plasma gave the same patterns of activity as human or bovine plasma. Human
urokinase (UK) and tissue plasminogen activator (t-PA) produced lysis in capybara
fibrin plates. Streptokinase (SK) (500 IU/ml) did not activate capybara or guinea
pig plasma. In this system, human plasma was extensively activated. Coagulation
tests for both species of rodent were prolonged. The capybara showed values for
prothrombin time (PT) shorter than activated thromboplastin time (APTT). The
guinea-pig, as already shown, had longer PT values. Factors X and VII were very
low for capybara and guinea-pig when tested using reference curves and diagnostic
kits for human plasma. It is suggested that the capybara could be a valuable
laboratory animal considering its size and closeness to the guinea-pig, and this
could allow for the provision of materials from one single animal when convenient
or necessary.
PMID- 10779738
TI - Glucose metabolism in crossbred Holstein cattle feeding on two types of roughage
at different stages of lactation.
AB - An experiment was performed to study the glucose kinetics of crossbred Holstein
cattle feeding on either hay or 5% urea-treated rice straw during early lactation
(30 days post partum), mid-lactation (120 days post partum) and late lactation
(210 days post partum). Two breeds: Holstein FriesianxRed Sindhi (50:50 = 50% HF)
and Holstein FriesianxRed Sindhi (87.5:12.5 = 87.5% HF) were used. In early
lactating 87.5% HF animals feeding on either hay or urea-treated rice straw, the
high milk yields and lactose secretion were related to glucose uptake by the
udder and udder blood flow as compared with those of 50% HF animals. Marked
decreases in udder blood flow, glucose uptake, lactose secretion and milk yield
were apparent in mid- and late lactation of both groups of 87.5% HF animals. In
contrast, both groups of 50% HF animals showed no significant changes in udder
blood flow, udder glucose uptake, lactose secretion and milk yields throughout
the course of lactation. Total glucose entry rate using 3-[3H] glucose infusion,
recycling of glucose carbon and plasma glucose clearance significantly increased
during late lactation for 50 and 87.5% HF animals feeding on urea-treated rice
straw. The utilization rates of glucose using [U-(14)C] glucose infusion were not
significantly different among groups of animals and periods of lactation. It can
be concluded that 87.5% HF animals have the genetic potential for a higher milk
yield, but a shorter peak yield and poorer persistence in comparison with 50% HF
animals. Changes in the utilization of glucose by the mammary gland for milk
production in both groups of crossbred animals during feeding on either hay or
urea-treated rice straw would be dependent on intramammary changes.
PMID- 10779739
TI - Mitochondria-rich cells in anuran amphibia: chloride conductance and regional
distribution over the body surface.
AB - The distribution and density (D(mrc)) of mitochondria-rich cells (MR cells) in
skin epithelium, were determined over the whole body surface in nine species of
anuran Amphibia that live in a variety of habitats. It was found that the more
terrestrial species (beginning with Hyla arborea) have a higher density of MR
cells in their pelvic region. In the skin of aquatic (Xenopus laevis) or
fossorial (Pelobates syriacus) species, D(mrc) is evenly distributed over the
whole body surface. In dorsal skin pieces of H. arborea that lack detectable MR
cells, transepithelial voltage activation did not induce Cl(-) conductance as it
did in ventral pieces. Skins from Bufo viridis and X. laevis, both have MR cells
in their skin, differ markedly in their biophysical properties: a Cl(-) specific
current conductance is predominant in the skin epithelium of B. viridis, and is
absent in X. laevis. In the latter, anionic conductance is due to glandular
secretion. The biophysical properties cannot therefore be related solely to the
presence or density of MR cells. Mitochondria-rich cells are sites of Cl(-)
conductance across the skin of those amphibians that show this property, but must
have different function(s) in other species. It is suggested that the specific
zonal distribution of MR cells in the species that were examined in this study
could be due to ion exchange activity and water conservation in more terrestrial
environments.
PMID- 10779740
TI - Thermoregulation and the effect of body temperature on call temporal parameters
in the cicada Diceroprocta olympusa (Homoptera: Cicadidae).
AB - We investigated the thermoregulatory behavior, thermal responses (minimum flight,
maximum voluntary tolerance and heat torpor temperatures) and the effect of body
temperature (T(b)) on call parameters in the cicada Diceroprocta olympusa
(Walker). Regression of T(b) as a function of ambient (T(a)) or perch
temperatures (T(p)) suggests thermoregulation is occurring. Thermoregulation
occurs through behavioral changes that alter the uptake of solar radiation. T(p)
is a better predictor of T(b) than is T(a). Thermal responses (minimum flight
temperature 20.4 degrees C, maximum voluntary tolerance temperature 37 degrees C,
and heat torpor temperature 46.7 degrees C) may be related to the humid,
grassland habitat of the species. In contrast to other acoustic insects, no
significant relationship was found between the temporal parameters of the calling
song and T(b) within the population of D. olympusa.
PMID- 10779741
TI - Cutting edge: CD4 is not required for the functional activity of IL-16.
AB - IL-16 functions as a chemoattractant factor, inhibitor of HIV replication, and
inducer of proinflammatory cytokine production. Previous studies have suggested
that CD4 is the receptor for IL-16, because only CD4+ cells respond to IL-16 and
both the anti-CD4 Ab OKT4 and soluble CD4 can block IL-16 function. However,
these are only indirect evidence of a requirement for CD4, and to date a direct
interaction between IL-16 and CD4 has not been shown. In this paper, we report
that cells from CD4 knockout mice are as responsive to IL-16 as their CD4 wild
type equivalents in both assays testing for IL-16 function (chemotaxis and
production of proinflammatory cytokines). In addition, the inhibitory effect of
soluble CD4 on IL-16 function observed using CD4 wild type murine cells was not
observed using CD4 knockout cells. These data demonstrate that CD4 is not
required for IL-16 function and suggest that another molecule acts as the major
receptor.
PMID- 10779742
TI - Blockade of T cell activation using a surface-linked single-chain antibody to
CTLA-4 (CD152).
AB - CTLA-4 (CD152) engagement can down-regulate T cell activation and promote the
induction of immune tolerance. However, the strategy of attenuating T cell
activation by engaging CTLA-4 has been limited by sharing of its natural ligands
with the costimulatory protein CD28. In the present study, a CTLA-4-specific
single-chain Ab (scFv) was developed and expressed on the cell surface to promote
selective engagement of this regulatory molecule. Transfectants expressing anti
CTLA-4 scFv at their surface bound soluble CTLA-4 but not soluble CD28.
Coexpression of anti-CTLA-4 scFv with anti-CD3epsilon and anti-CD28 scFvs on
artificial APCs reduced the proliferation and IL-2 production by resting and
preactivated bulk T cells as well as CD4+ and CD8+ T cell subsets. Importantly,
expression of anti-CTLA-4 scFv on the same cell surface as the TCR ligand was
essential for the inhibitory effects of CTLA-4-specific ligation. CTLA-4-mediated
inhibition of tyrosine phosphorylation of components of the proximal TCR
signaling apparatus was similarly dependent on coexpression of TCR and CTLA-4
ligands on the same surface. These findings support a predominant role for CTLA-4
function in the modification of the proximal TCR signal. Using T cells from
DO11.10 and 2C TCR transgenic mice, negative regulatory effects of selective CTLA
4 ligation were also demonstrated during the stimulation of Ag-specific CD4+ and
CD8+ T cells by MHC/peptide complexes. Together these studies demonstrate that
selective ligation of CTLA-4 using a membrane-bound scFv results in attenuated T
cell responses only when coengaged with the TCR during T cell/APC interaction and
define an approach to harnessing the immunomodulatory potential of CTLA-4
specific ligation.
PMID- 10779743
TI - Vitamin D3 affects differentiation, maturation, and function of human monocyte
derived dendritic cells.
AB - We studied the effects of 1alpha,25-dihydroxyvitamin D3 (1alpha, 25-(OH)2D3) on
differentiation, maturation, and functions of dendritic cells (DC) differentiated
from human monocytes in vitro in the presence of GM-CSF and IL-4 for 7 days.
Recovery and morphology were not affected by 1alpha,25-(OH)2D3 up to 100 nM. DC
differentiated in the presence of 10 nM 1alpha,25-(OH)2D3 (D3-DC) showed a marked
decrease in the expression of CD1a, while CD14 remained elevated. Mannose
receptor and CD32 were significantly increased, and this correlated with an
enhancement of endocytic activity. Costimulatory molecules such as CD40 and CD86
were slightly decreased or nonsignificantly affected (CD80 and MHC II). However,
after induction of DC maturation with LPS or incubation with CD40 ligand
transfected cells, D3-DC showed marginal increases in MHC I, MHC II, CD80, CD86,
CD40, and CD83. The accessory cell function of D3-DC in classical MLR was also
inhibited. Moreover, allogeneic T cells stimulated with D3-DC were poor
responders in a second MLR to untreated DC from the same or an unrelated donor,
thus indicating the onset of a nonspecific hyporesponsivity. In conclusion, our
data suggest that 1alpha,25-(OH)2D3 may modulate the immune system, acting at the
very first step of the immune response through the inhibition of DC
differentiation and maturation into potent APC.
PMID- 10779744
TI - Donor MHC class II antigen is essential for induction of transplantation
tolerance by bone marrow cells.
AB - Posttransplant infusion of donor bone marrow cells (BMC) induces tolerance to
allografts in adult mice, dogs, nonhuman primates, and probably humans. Here we
used a mouse skin allograft model and an allogeneic radiation chimera model to
examine the role of MHC Ags in tolerance induction. Infusion of MHC class II Ag
deficient (CIID) BMC failed to prolong C57BL/6 (B6) skin grafts in ALS- and
rapamycin-treated B10.A mice, whereas wild-type B6 or MHC class I Ag-deficient
BMC induced prolongation. Removal of class II Ag-bearing cells from donor BMC
markedly reduced the tolerogenic effect compared with untreated BMC, although
graft survival was significantly longer in mice given depleted BMC than that in
control mice given no BMC. Infusion of CIID BMC into irradiated syngeneic B6 or
allogeneic B10.A mice produced normal lymphoid cell reconstitution including CD4+
T cells except for the absence of class II Ag-positive cells. However, irradiated
B10.A mice reconstituted with CIID BMC rejected all B6 and a majority of CIID
skin grafts despite continued maintenance of high degree chimerism. B10.A mice
reconstituted with B6 BMC maintained chimerism and accepted both B6 and CIID skin
grafts. Thus, expression of MHC class II Ag on BMC is essential for allograft
tolerance induction and peripheral chimerism with cells deficient in class II Ag
does not guarantee allograft acceptance.
PMID- 10779745
TI - Analysis of human V alpha 24+ CD4+ NKT cells activated by alpha-glycosylceramide
pulsed monocyte-derived dendritic cells.
AB - Human V alpha 24+ NKT cells with an invariant TCR (V alpha 24-J alpha Q) have
been shown to be specifically activated by synthetic glycolipids such as alpha
galactosylceramide and alpha-glucosylceramide in a CD1d-restricted and V alpha 24
TCR-mediated manner. We recently characterized V alpha 24+ CD4- CD8- double
negative (DN) NKT cells using alpha-galactosylceramide-pulsed monocyte-derived
dendritic cells. Here, we compare V alpha 24+ CD4+ NKT cells with human V alpha
24+ DN NKT cells from the same donor using alpha-galactosylceramide-pulsed
monocyte-derived dendritic cells. Human V alpha 24+ CD4+ NKT cells were
phenotypically and functionally similar to the human V alpha 24+ DN NKT cells
characterized previously. Both of them use V alpha 24-J alpha Q-V beta 11 TCR and
express CD161 (NKR-P1A), but not the other NK receptors tested so far. They also
produce cytokines such as IL-4 and IFN-gamma, and, in regard to IL-4 production,
V alpha 24+ CD4+ NKT cells produce more IL-4 than V alpha 24+ DN NKT cells. The
cells exhibit marked cytotoxic activity against the U937 tumor cell line, but not
against the NK target cell line, K562. Although at least some of the factors
responsible for the stimulation of V alpha 24+ NKT cells have been clarified,
little is known regarding the killing phase of these cells. Here we show that the
cytotoxic activity of V alpha 24+ NKT cells against U937 cells is mediated mainly
through the perforin pathway and that ICAM-1/LFA-1 as well as CD44/hyaluronic
acid interactions are important for the effector phase of V alpha 24+ NKT cell
mediated cytotoxicity against U937 cells.
PMID- 10779746
TI - The roles of CD28 and CD40 ligand in T cell activation and tolerance.
AB - Costimulation of T cell activation involves both the B7:CD28 as well as the CD40
ligand (CD40L):CD40 pathway. To determine the importance of these pathways to in
vitro and in vivo T cell activation, a direct comparison was made of the
responses of TCR transgenic T cells lacking either CD28 or CD40L. In vitro, CD28
/- T cells showed a greater reduction in proliferative responses to Ag than did
CD40L-/- T cells. The absence of CD28 resulted in defective Th2 responses,
whereas CD40L-/- T cells were defective in Th1 development. In vivo, CD28-/- T
cells failed to expand upon immunization, whereas CD40L-/- T cells could not
sustain a response. These results suggest that CD28 is critical for initiating T
cell responses, whereas CD40L is required for sustained Th1 responses. The
different functional roles of these costimulatory pathways may explain why
blocking B7:CD28 and CD40L:CD40 interactions has an additive effect in inhibiting
T cell responses.
PMID- 10779747
TI - The regulation of CD95 (Fas) ligand expression in primary T cells: induction of
promoter activation in CD95LP-Luc transgenic mice.
AB - The interaction between CD95 (Fas) and CD95L (Fas ligand) initiates apoptosis in
a variety of cell types. Although the regulation of CD95L expression on activated
T cells is an area of intense study, knowledge related to the induction of CD95L
promoter activity in primary T cells is lacking. In this report we describe the
generation of a novel transgenic mouse strain, CD95LP-Luc, in which murine CD95L
promoter sequence controls the expression of a luciferase reporter gene. We use
these mice to illustrate several important findings related to transcriptional
regulation of CD95L in primary T cells. We demonstrate that maximal CD95L
promoter activity occurs only after prolonged T cell stimulation and requires
costimulation through CD28. We provide evidence that thymocytes express
CD95L/luciferase after strong TCR ligation and that inducible CD95L promoter
activation is present, but unequal, in both Th1 and Th2 effector cells. We also
illustrate that while agonist peptide presentation by APCs generates robust
proliferation during a primary T cell response, the same stimulus induces only
modest CD95L promoter activity. These results suggest alternate explanations for
the well-characterized delay in CD95-mediated activation-induced cell death
following initial ligation of the TCR.
PMID- 10779748
TI - Astrocyte-targeted expression of IL-12 induces active cellular immune responses
in the central nervous system and modulates experimental allergic
encephalomyelitis.
AB - The role of IL-12 in the evolution of immunoinflammatory responses at a localized
tissue level was investigated. Transgenic mice were developed with expression of
either both the IL-12 subunits (p35 and p40) or only the IL-12 p40 subunit genes
targeted to astrocytes in the mouse CNS. Glial fibrillary acidic protein (GF)-IL
12 mice, bigenic for the p35 and p40 genes, developed neurologic disease which
correlated with the levels and sites of transgene-encoded IL-12 expression. In
these mice, the brain contained numerous perivascular and parenchymal
inflammatory lesions consisting of predominantly CD4+ and CD8+ T cells as well as
NK cells. The majority of the infiltrating T cells had an activated phenotype
(CD44high, CD45Rblow, CD62Llow, CD69high, VLA-4 high, and CD25+). Functional
activation of the cellular immune response was also evident with marked cerebral
expression of the IFN-gamma, TNF, and IL-1alphabeta genes. Concomitant with
leukocyte infiltration, the CNS expression of immune accessory molecules was
induced or up-regulated, including ICAM-1, VCAM-1, and MHC class II and B7-2.
Glial fibrillary acidic protein-p40 mice with expression of IL-12 p40 alone
remained asymptomatic, with no inflammation evident at any age studied. The
effect of local CNS production of IL-12 in the development of experimental
autoimmune encephalomyelitis was studied. After immunization with myelin
oligodendrocyte glycoprotein-peptides, GF-IL-12 mice had an earlier onset and
higher incidence but not more severe disease. We conclude that localized
expression of IL-12 by astrocytes can 1) promote the spontaneous development of
activated type 1 T cell and NK cellular immunity and cytokine responses in the
CNS, and 2) promote more effective Ag-specific T cell dynamics but not activity
in experimental autoimmune encephalomyelitis.
PMID- 10779749
TI - Delayed and separate costimulation in vitro supports the evidence of a transient
"excited" state of CD8+ T cells during activation.
AB - Although the two-signal model for T cell activation states that a signal-1
through the TCR and a costimulatory signal-2 are required for optimal
stimulation, it is now clear that the requirement for costimulation can be
bypassed under certain conditions. We previously reported that this is the case
for naive CD8+ T cells in vitro. In the present study we tested the effect of
signal-2 when delivered after signal-1 has been disrupted. Naive CD8+ T cells
from TCR transgenic mice were stimulated in vitro by using immobilized
recombinant single-chain MHC molecules alone as signal-1. This signal was then
stopped after different lengths of time, and anti-CD28 mAb as signal-2 was given
either immediately or after a time lag. We found that signal-2 can potentiate a
short signal-1 when added sequentially. Moreover, a time lag between the two
signals does not abolish this potentiation. If the strength of signal-1, but not
its duration, is increased, then the time lag between the delivery of signals 1
and 2 can be lengthen without loss of potentiation. Together, our results
indicate that the two signals do not need to be delivered concomitantly to get
optimal T cell activation. We suggest that the CD8+ T cells can reach a transient
"excited" state after being stimulated with signal-1 alone, characterized by the
cell's ability to respond to separate and delayed signal-2.
PMID- 10779750
TI - MHC class I antigen processing of an adenovirus CTL epitope is linked to the
levels of immunoproteasomes in infected cells.
AB - Proteasomes are the major source for the generation of peptides bound by MHC
class I molecules. To study the functional relevance of the IFN-gamma-inducible
proteasome subunits low molecular mass protein 2 (LMP2), LMP7, and mouse
embryonal cell (MEC) ligand 1 in Ag processing and concomitantly that of
immunoproteasomes, we established the tetracycline-regulated mouse cell line
MEC217, allowing the titrable formation of immunoproteasomes. Infection of MEC217
cells with Adenovirus type 5 (Ad5) and analysis of Ag presentation with Ad5
specific CTL showed that cells containing immunoproteasomes processed the viral
early 1B protein (E1B)-derived epitope E1B192-200 with increased efficiency, thus
allowing a faster detection of viral entry in induced cells. Importantly, optimal
CTL activation was already achieved at submaximal immunosubunit expression. In
contrast, digestion of E1B-polypeptide with purified proteasomes in vitro yielded
E1B192-200 at quantities that were proportional to the relative contents of
immunosubunits. Our data provide evidence that the IFN-gamma-inducible proteasome
subunits, when present at relatively low levels as at initial stages of
infection, already increase the efficiency of antigenic peptide generation and
thereby enhance MHC class I Ag processing in infected cells.
PMID- 10779751
TI - Development of Th1-inducing capacity in myeloid dendritic cells requires
environmental instruction.
AB - Dendritic cells (DC) are key initiators of primary immune responses. Myeloid DC
can secrete IL-12, a potent Th1-driving factor, and are often viewed as Th1
promoting APC. Here we show that neither a Th1- nor a Th2-inducing function is an
intrinsic attribute of human myeloid DC, but both depend on environmental
instruction. Uncommitted immature DC require exposure to IFN-gamma, at the moment
of induction of their maturation or shortly thereafter, to develop the capacity
to produce high levels of IL-12p70 upon subsequent contact with naive Th cells.
This effect is specific for IFN-gamma and is not shared by other IL-12-inducing
factors. Type 1-polarized effector DC, matured in the presence of IFN-gamma,
induce Th1 responses, in contrast to type 2-polarized DC matured in the presence
of PGE2 that induce Th2 responses. Type 1-polarized effector DC are resistant to
further modulation, which may facilitate their potential use in immunotherapy.
PMID- 10779752
TI - Evidence of selective processing of immunodominant epitopes in virally infected
cells.
AB - Recent advances in clarifying the molecular mechanisms involved in Ag processing
and presentation have relied heavily on the use of somatic cell mutants deficient
in proteasome subunits, TAP transporter, and cell surface expression of MHC class
I molecules. Of particular interest currently are those mutants that lack
specific protease activity involved in the generation of antigenic peptides. It
is theoretically possible that deficiencies of this nature could selectively
prevent the cleavage of certain peptide bonds and thus generate only a subset of
antigenic peptides. Gro29/Kb cell line is derived from the wild-type murine Ltk-
cell line. This cell line is one example of a mutant that lacks specific protease
activities. This deficiency manifests itself in an inability to generate a subset
of immunodominant peptide epitopes derived from vesicular stomatitis virus and
herpes simplex virus. This in turn leads to a general inability to present these
viral epitopes to cytotoxic T lymphocytes (CTL). These studies describe a unique
Ag processing deficiency and provide new insight into the role of proteasome
independent proteases in MHC class I-restricted peptide generation.
PMID- 10779753
TI - Humoral immune responses in Cr2-/- mice: enhanced affinity maturation but
impaired antibody persistence.
AB - Deficiency in CD21/CD35 by disruption of the Cr2 loci leads to impaired humoral
immune responses. In this study, we detail the role of CD21/CD35 on Ab responses
to the hapten (4-hydroxy-3-nitrophenyl)acetyl conjugated to chicken gamma
globulin. Surprisingly, Cr2-/- mice generate significant Ab responses and
germinal center (GC) reactions to low doses of this Ag in alum, although the
magnitude of their responses is much reduced in comparison with those of Cr2+/-
and C57BL/6 controls. Increasing Ag dose partially corrected this deficit. In
situ study of the somatic genetics of GC B cells demonstrated that VDJ
hypermutation does not require CD21/CD35, and Cr2-/- mice exhibited enhanced
affinity maturation of serum Ab in the post-GC phase of the primary response. On
the other hand, Cr2-/- mice displayed accelerated loss of serum Ab and long-lived
Ab-forming cells. These observations suggest that B cell activation/survival
signals mediated by CD21 and/or the retention of Ag by CD21/CD35 play important
roles in the generation, quality, and maintenance of serum Ab.
PMID- 10779754
TI - Crry/p65, a membrane complement regulatory protein, has costimulatory properties
on mouse T cells.
AB - It is known that certain type I membrane molecules (complement receptors type 1
and 2) belonging to the regulators of complement activation (RCA) family are
involved in the regulation of B lymphocyte activation. In contrast, only GPI
anchored RCA molecules (CD55) have been described to be involved in T lymphocyte
activation. In this study, we describe a novel function for the mouse RCA type I
membrane protein Crry/p65 as a costimulatory molecule in CD4+ T cell activation.
This is shown by increased anti-CD3-induced proliferation of CD4+ spleen T
lymphocytes in the presence of the Crry/p65-specific mAb P3D2. Furthermore, Ab
induced coligation of Crry/p65 and CD3 favors IL-4 rather than IFN-gamma
secretion in these cells. Crry/p65 signaling was also observed regardless of
additional Ca2+, protein kinase C, or CD28-mediated costimuli. Analysis of
intracellular intermediaries shows that Crry/p65-CD3 coligation enhances certain
TCR/CD3-mediated signals, producing increased early tyrosine phosphorylation of
many substrates and enhanced activation of the mitogen-activated protein kinase,
extracellular signal-related kinase. These data fit well with the association of
Crry/p65 with the tyrosine kinase Lck found in T cell lysates. The epitope
recognized by the mAb P3D2 interferes with the protective role of Crry/p65 on C3
deposition. The relationship between protective function and costimulation by
Crry/p65 is discussed. Our results support a multifunctional role for Crry/p65 in
T cells and suggest new links between the natural and adaptive immune responses.
PMID- 10779755
TI - In vivo behavior of peptide-specific T cells during mucosal tolerance induction:
antigen introduced through the mucosa of the conjunctiva elicits prolonged
antigen-specific T cell priming followed by anergy.
AB - The mucosa of the conjunctiva is an important site of entry for environmental Ags
as well as Ags emanating from the eye itself. However, very little is known about
T cell recognition of Ag introduced through this important mucosal site. We have
characterized the in vivo process of CD4 T cell recognition of Ag delivered via
the conjunctival mucosa. Application of soluble OVA to the conjunctiva of BALB/c
mice induced potent T cell tolerance. APC-presenting OVA peptide in vivo was only
found in the submandibular lymph node and not in other lymph nodes, spleen, or
nasal-associated lymphoid tissue. Similarly, in TCR transgenic DO11. 10 adoptive
transfer mice, OVA-specific CD4+ T cell clonal expansion was only observed in the
submandibular lymph node following conjunctival application of peptide. These
experiments thus define a highly specific lymphatic drainage pathway from the
conjunctiva. OVA-specific T cell clonal expansion peaked at day 3 following
initiation of daily OVA administration and gradually declined during the 10-day
treatment period, but remained elevated compared with nontreated adoptive
transfer mice. During this period, the T cells expressed activation markers, and
proliferated and secreted IL-2 in vitro in response to OVA stimulation. In
contrast, these cells were unable to clonally expand in vivo, or proliferate in
vitro following a subsequent OVA/CFA immunization. These results suggest that Ag
applied to a mucosal site can be efficiently presented in a local draining lymph
node, resulting in initial T cell priming and clonal expansion, followed by T
cell anergy.
PMID- 10779756
TI - Antigen-experienced CD4 T cells display a reduced capacity for clonal expansion
in vivo that is imposed by factors present in the immune host.
AB - It is thought that protective immunity is mediated in part by Ag-experienced T
cells that respond more quickly and vigorously than naive T cells. Using adoptive
transfer of OVA-specific CD4 T cells from TCR transgenic mice as a model system,
we show that Ag-experienced CD4 T cells accumulate in lymph nodes more rapidly
than naive T cells after in vivo challenge with Ag. However, the magnitude of
clonal expansion by Ag-experienced T cells was much less than that of naive T
cells, particularly at early times after primary immunization. Ag-experienced CD4
T cells quickly reverted to the slower but more robust clonal expansion behavior
of naive T cells after transfer into a naive environment. Conversely, the
capacity for rapid clonal expansion was acquired by naive CD4 T cells after
transfer into passively immunized recipients. These results indicate that rapid
in vivo response by Ag-experienced T cells is facilitated by Ag-specific Abs,
whereas the limited capacity for clonal expansion is imposed by some other factor
in the immune environment, perhaps residual Ag.
PMID- 10779758
TI - CD28-specific antibody prevents graft-versus-host disease in mice.
AB - The costimulatory molecules B7-1 and B7-2 regulate T cell activation by
delivering activation signals through CD28 and inhibitory signals through CTLA4.
Graft-vs-host disease (GVHD) is caused by activated donor T cells. Previously, we
showed that CD28-deficient donor T cells induced less-severe GVHD than wild-type
donor T cells, suggesting that CD28 signals exacerbate GVHD. In this paper we
demonstrate that CTLA4 signals attenuate the severity of GVHD. Targeting the CD28
receptor with a specific mAb modulates the receptor in vivo, inhibits donor T
cell expansion, and prevents GVHD. CTLA4 signaling was necessary for this effect
because treatment with a soluble ligand that blocks binding of B7 to both CD28
and CTLA4 did not prevent GVHD as effectively as anti-CD28 mAb. These results
support the current model of T cell costimulation in which CD28 signals amplify
GVHD while CTLA4 signals inhibit GVHD, providing evidence that selective
targeting of CD28 might be a better therapeutic strategy for inducing
immunological tolerance than blocking the ligands for both CD28 and CTLA4.
PMID- 10779757
TI - Secondary lymphoid tissue chemokine mediates T cell-dependent antitumor responses
in vivo.
AB - Secondary lymphoid tissue chemokine (SLC, also referred to as Exodus 2 or 6Ckine)
is a recently identified high endothelial-derived CC chemokine. The ability of
SLC to chemoattract both Th1 lymphocytes and dendritic cells formed the rationale
to evaluate this chemokine in cancer immunotherapy. Intratumoral injection of
recombinant SLC evidenced potent antitumor responses and led to complete tumor
eradication in 40% of treated mice. SLC-mediated antitumor responses were
lymphocyte dependent as evidenced by the fact that this therapy did not alter
tumor growth in SCID mice. Studies performed in CD4 and CD8 knockout mice also
revealed a requirement for both CD4 and CD8 lymphocyte subsets for SLC-mediated
tumor regression. In immunocompetent mice, intratumoral SLC injection led to a
significant increase in CD4 and CD8 T lymphocytes and dendritic cells,
infiltrating both the tumor and the draining lymph nodes. These cell infiltrates
were accompanied by the enhanced elaboration of Th1 cytokines and chemokines
monokine induced by IFN-gamma and IFN-gamma-inducible protein 10 but a
concomitant decrease in immunosuppressive cytokines at the tumor site. In
response to irradiated autologous tumor, splenic and lymph node-derived cells
from SLC-treated tumor-bearing mice secreted significantly more IFN-gamma, GM
CSF, and IL-12 and reduced levels of IL-10 than did diluent-treated tumor-bearing
mice. After stimulation with irradiated autologous tumor, lymph node-derived
lymphocytes from SLC-treated tumor-bearing mice demonstrated enhanced cytolytic
capacity, suggesting the generation of systemic immune responses. These findings
provide a strong rationale for further evaluation of SLC in tumor immunity and
its use in cancer immunotherapy.
PMID- 10779759
TI - Faithful expression of the human 5q31 cytokine cluster in transgenic mice.
AB - Interleukins -4, -5, and -13, cardinal cytokines produced by Th2 cells, are
coordinately expressed and clustered in 150-kb syntenic regions on mouse
chromosome 11 and human chromosome 5q31. We analyzed two sets of human yeast
artificial chromosome transgenic mice that contained the 5q31 cytokines to assess
whether conserved sequences required for their coordinate and cell-specific
regulation are contained within the cytokine cluster itself. Human IL-4, IL-13,
and IL-5 were expressed under Th2, but not Th1, conditions in vitro. Each of
these cytokines was produced during infection with Nippostrongylus brasiliensis,
a Th2-inducing stimulus, and human IL-4 was generated after activation of NK T
cells in vivo. Consistently fewer cells produced the endogenous mouse cytokines
in transgenic than in control mice, suggesting competition for stable expression
between the mouse and human genes. These data imply the existence of both
conserved trans-activating factors and cis-regulatory elements that underlie the
coordinate expression and lineage specificity of the type 2 cytokine genes in
lymphocytes.
PMID- 10779760
TI - IL-2 signaling in human monocytes involves the phosphorylation and activation of
p59hck.
AB - The activating properties of IL-2 and the structure of the IL-2R on human
monocytes are well characterized. However, relatively little is known about the
biochemical mechanisms involved in IL-2 signal transduction in these cells. We
investigated the role of protein tyrosine kinases (PTKs) in the activation of
monocytes by IL-2. Incubation of monocytes with the PTK inhibitor herbimycin A
(HA) resulted in the dose-dependent suppression of IL-2-induced monocyte
tumoricidal activity. This inhibition was rather potent, as a concentration of HA
as low as 0.5 microM caused a complete abrogation of cytolytic activity.
Furthermore, HA markedly suppressed the ability of IL-2 to induce IL-1 beta, TNF
alpha, IL-6, and IL-8 mRNA expression and protein secretion by monocytes. Anti
phosphotyrosine immunoblotting demonstrated that IL-2 induced a rapid and time
dependent increase in tyrosine phosphorylation of several cellular proteins of
molecular masses ranging from 35 to 180 kDa. Interestingly, IL-2 caused a
significant up-regulation of the constitutive levels of hck PTK mRNA and protein
relative to medium-treated cells as well as an increase in p59hck tyrosine
phosphorylation. Finally, we demonstrated by in vitro kinase assay that the
specific activity of p59hck PTK was also induced by IL-2 in monocytes. Thus,
these data show that the activation of PTKs is required for the triggering of
monocyte effector and secretory functions by IL-2 and strongly suggest that
p59hck is a key participant in IL-2 signaling in human monocytes.
PMID- 10779761
TI - A VH11V kappa 9 B cell antigen receptor drives generation of CD5+ B cells both in
vivo and in vitro.
AB - B lymphocytes can be divided into different subpopulations, some with distinctive
activation requirements and probably mediating specialized functions, based on
surface phenotype and/or anatomical location, but the origins of most of these
populations remain poorly understood. B cells constrained by transgenesis to
produce an Ag receptor derived from a conventional (B-2) type cell develop a B-2
phenotype, whereas cells from mice carrying a B-1-derived receptor acquire the B
1 phenotype. In this study transgenic enforced expression of a B cell receptor
(mu/kappa) originally isolated from a CD5+ (B-1a) B cell generates B-1 phenotype
cells in bone marrow cultures that show a distinctive B-1 function, survival in
culture. Despite their autoreactivity, we find no evidence for receptor editing
or that the paucity of B-2 cells is the result of tolerance-induced selection.
Finally, Ca2+ mobilization studies reveal a difference between transgenic B-1
cells in spleen and peritoneal cavity, with cells in spleen much more responsive
to anti-B cell receptor cross-linking. We discuss these results in terms of
specificity vs lineage models for generation of distinctive B cell
subpopulations.
PMID- 10779763
TI - A physiological ligand of positive selection is seen with high specificity.
AB - Positive selection is a process that ensures that peripheral T cells express TCR
that are restricted to self-MHC molecules. This process requires both self-MHC
and self-peptides. We have recently established a TCR transgenic mouse model
(C10.4 TCRtrans+) in which the transgenic TCR was selected on the nonclassical
MHC class Ib molecule H2-M3 in conjunction with a physiologically occurring
peptide derived from the mitochondrial NADH-dehydrogenase subunit 1 gene (9-mer
peptide). Here, the specificity of positive selection of C10.4 TCRtrans+ T cells
was examined using a fetal thymic organ culture system. We demonstrated that at
low peptide concentrations, shortening the NADH-dehydrogenase subunit 1 gene 9
mer peptide or mutating its surface-exposed side chains severely impaired its
ability to induce positive selection. We concluded that under physiological
conditions positive selection of C10.4 TCRtrans+ T cells was highly specific and
occurred at low epitope densities.
PMID- 10779762
TI - Breakdown of tolerance to a neo-self antigen in double transgenic mice in which B
cells present the antigen.
AB - Transgenic (Tg) mice expressing a foreign Ag, hen egg lysozyme (HEL), under
control of the alphaA-crystallin promoter ("HEL-Tg" mice) develop immunotolerance
to HEL attributed to the expression of HEL in their thymus. In this paper we
analyzed the immune response in double (Dbl)-Tg mice generated by mating the HEL
Tg mice with Tg mice that express HEL Abs on their B cells ("Ig-Tg" mice). The B
cell compartment of the Dbl-Tg mice was unaffected by the HEL presence and was
essentially identical to that of the Ig-Tg mice. A partial breakdown of tolerance
was seen in the T cell response to HEL of the Dbl-Tg mice, i.e., their lymphocyte
proliferative response against HEL was remarkably higher than that of the HEL-Tg
mice. T-lymphocytes of both Dbl-Tg and Ig-Tg mice responded to HEL at
concentrations drastically lower than those found stimulatory to lymphocytes of
the wild-type controls. Cell mixing experiments demonstrated that 1) the
lymphocyte response against low concentrations of HEL is due to the exceedingly
efficient Ag presenting capacity of the Ab expressing B cells and 2) breakdown of
tolerance in Dbl-Tg mice can also be attributed to the APC capacity of B cells,
that sensitize in vivo and stimulate in vitro populations of T cells with low
affinity toward HEL, assumed to be escapees of thymic deletion. These results
thus indicate that T cell tolerance can be partially overcome by the highly
potent Ag presenting capacity of Ab expressing B cells.
PMID- 10779764
TI - Stat3-dependent induction of p19INK4D by IL-10 contributes to inhibition of
macrophage proliferation.
AB - We have previously reported that IL-10 inhibits proliferation of normal bone
marrow-derived macrophages and of the monocyte/macrophage cell line J774.
Activation of Stat3 was shown to be necessary and sufficient to mediate
inhibition of proliferation. To investigate further the mechanism of growth
arrest, we examined the effect of IL-10 on expression of cell cycle inhibitors.
We found that IL-10 treatment increases expression of the cyclin-dependent kinase
inhibitors p19INK4D and p21CIP1 in macrophages. IL-10 cannot induce p19INK4D
expression or block proliferation when Stat3 signaling is blocked by a dominant
negative Stat3 or a mutant IL-10Ralpha which does not recruit Stat3 in J774
cells, whereas p21CIP1 induction is not affected. An inducibly active Stat3
(coumermycin-dimerizable Stat3-Gyrase B), which suppresses J774 cell
proliferation, also induced p19INK4D expression. Sequencing of the murine
p19INK4D promoter revealed two candidate Stat3 binding sites, and IL-10 treatment
activated a reporter gene controlled by this promoter. These data suggest that
Stat3-dependent induction of p19INK4D mediates inhibition of proliferation.
Enforced expression of murine p19INK4D cDNA J774 cells significantly reduced
their proliferation. Use of antisense p19INK4D and analysis of p19INK4D-deficient
macrophages confirmed that p19INK4D is required for optimal inhibition of
proliferation by IL-10, and indicated that additional IL-10 signaling events
contribute to this response. These data indicate that Stat3-dependent induction
of p19INK4D and Stat3-independent induction of p21CIP1 are important components
of the mechanism by which IL-10 blocks proliferation in macrophages.
PMID- 10779765
TI - The linker phosphorylation site Tyr292 mediates the negative regulatory effect of
Cbl on ZAP-70 in T cells.
AB - The protooncogene product Cbl has emerged as a negative regulator of tyrosine
kinases. We have shown previously that Cbl binds to ZAP-70 through its N-terminal
tyrosine kinase binding (TKB) domain. In this study, we demonstrate that
overexpression of Cbl in Jurkat T cells decreases the TCR-induced phosphorylation
of ZAP-70 and other cellular phosphoproteins. Coexpression of Cbl with ZAP-70 in
COS cells reproduced the Cbl-induced reduction in the level of phosphorylated ZAP
70. The effect of Cbl was eliminated by the TKB-inactivating G306E mutation in
Cbl as well as by a phenylalanine mutation of Tyr292 within the TKB domain
binding site on ZAP-70. Notably, the oncogenic Cbl-70Z/3 mutant associated with
ZAP-70, but did not reduce the levels of phosphorylated ZAP-70. Overexpression of
Cbl, but not Cbl-G306E, in Jurkat T cells led to a decrease in the TCR-induced NF
AT luciferase reporter activity. Overexpression of the TKB domain itself, but not
its G306E mutant, functioned in a dominant-negative manner and led to an increase
in NF-AT reporter activity. Cbl-70Z/3-overexpressing cells exhibited an increase
in both basal and TCR-induced NF-AT luciferase reporter activity, and this trend
was reversed by the G306E mutation. Finally, by reconstituting a ZAP-70-deficient
Jurkat T cell line, p116, we demonstrate that wild-type ZAP-70 is susceptible to
the negative regulatory effect of Cbl, whereas the ZAP-70-Y292F mutant is
resistant. Together, our results establish that the linker phosphorylation site
Tyr292 mediates the negative regulatory effect of Cbl on ZAP-70 in T cells.
PMID- 10779766
TI - Functional and phenotypic evidence for presentation of E alpha 52-68 structurally
related self-peptide(s) in I-E alpha-deficient mice.
AB - The Y-Ae mAb and the 1H3.1 TCR-alpha beta (V alpha 1/V beta 6) are two immune
receptors specific for I-Ab MHC class II molecules complexed to the 52-68
fragment of the alpha-chain of I-E class II molecules (the E alpha 52-68
peptide). A profound intrathymic negative selection occurs in 1H3.1 TCR
transgenic mice in the presence of an I-E alpha transgene. The administration of
mAbs to 1H3.1/I-E alpha double-transgenic newborn mice reveals that Y-Ae, but not
the isotype-matched anti-I-E Y17 mAb, rescues a significant number of mature (V
beta 6highCD4+CD8-) thymocytes and allows the detection of E alpha 52-68-reactive
T cells in the periphery. These observations indicate that deletion of
autoreactive T cells can be specifically inhibited in vivo by an mAb specific for
the deleting self-peptide:self-MHC class II complex. Similar inhibition
experiments indicate that C57BL/6 (I-Ab+/I-E alpha-) mice constitutively express
an E alpha-independent, Y-Ae-recognizable epitope(s). This finding is confirmed
by the phenotypic analysis of mature (MHC class II high) C57BL/6 bone marrow
derived dendritic cells. Collectively, these observations further illustrate the
peptide specificity of negative selection and demonstrate that MHC class II
positive cells from unmanipulated C57BL/6 mice that lack a functional I-E alpha
gene can assemble one or more self-peptide:I-Ab complexes recognizable by the E
alpha 52-68:I-Ab complex-specific Y-Ae mAb.
PMID- 10779767
TI - Increased DNA vaccine delivery and immunogenicity by electroporation in vivo.
AB - DNA vaccines have been demonstrated to be potent in small animals but are less
effective in primates. One limiting factor may be inefficient uptake of DNA by
cells in situ. In this study, we evaluated whether cellular uptake of DNA was a
significant barrier to efficient transfection in vivo and subsequent induction of
immune responses. For this purpose, we used the technique of electroporation to
facilitate DNA delivery in vivo. This technology was shown to substantially
increase delivery of DNA to cells, resulting in increased expression and elevated
immune responses. The potency of a weakly immunogenic hepatitis B surface Ag DNA
vaccine was increased in mice, as seen by a more rapid onset and higher magnitude
of anti-hepatitis B Abs. In addition, the immunogenicity of a potent HIV gag DNA
vaccine was increased in mice, as seen by higher Ab titers, a substantial
reduction in the dose of DNA required to induce an Ab response, and an increase
in CD8+ T cell responses. Finally, Ab responses were enhanced by electroporation
against both components of a combination HIV gag and env DNA vaccine in guinea
pigs and rabbits. Therefore, cellular uptake of DNA is a significant barrier to
transfection in vivo, and electroporation appears able to overcome this barrier.
PMID- 10779768
TI - Cell death-associated translocation of plasma membrane components induced by CTL.
AB - In the very early stages of target cell apoptosis induced by CTL, we found that
fluorescence of labeling probes of the target plasma membrane, such as N-(3
triethylammoniumpropyl)-4-(p-dibutylaminostyryl)pyridin ium dibromide (FM1-43),
was translocated into intracellular membrane structures including nuclear
envelope and mitochondria. This translocation was associated with the execution
of CTL-mediated killing, because neither the CTL-target conjugation alone nor the
binding of noncytotoxic Th2 clone with target cell was sufficient to provoke the
process. Although FM1-43 translocation was observed in perforin-mediated
cytotoxicity, examinations with several other dyes failed to detect the evidence
for membrane damages that may cause influx of the dye. Moreover, the
translocation was also observed in Fas-dependent apoptosis. These data indicate
that the translocation precedes the damage of plasma membrane and intracellular
organella in the course of apoptotic cell death and may represent the existence
of a membrane trafficking that mediates the translocation of plasma membrane
components in the early onset of apoptotic cell death.
PMID- 10779769
TI - Thymic dendritic cells express inducible nitric oxide synthase and generate
nitric oxide in response to self- and alloantigens.
AB - Thymocytes maturing in the thymus undergo clonal deletion/apoptosis when they
encounter self- or allo-Ags presented by dendritic cells (DCs). How this occurs
is a matter of debate, but NO may play a role given its ability of inducing
apoptosis of these cells. APC (a mixed population of macrophages (Mphi) and DCs)
from rat thymus expressed high levels of inducible NO synthase (iNOS) and
produced large amounts of NO in basal conditions whereas iNOS expression and NO
production were very low in thymocytes. Analysis by FACS and by double labeling
of cytocentrifuged preparations showed that DCs and MPhi both express iNOS within
APC. Analysis of a purified preparation of DCs confirmed that these cells express
high levels of iNOS and produce large amounts of NO in basal conditions. The
capacity of DCs to generate NO was enhanced by exposure to rat albumin, a self
protein, and required a fully expressed process of Ag internalization,
processing, and presentation. Peptides derived from portions of class II MHC
molecules up-regulate iNOS expression and NO production by DCs as well, both in
self and allogeneic combinations, suggesting a role of NO in both self and
acquired tolerance. We also found that NO induced apoptosis of rat double
positive thymocytes, the effect being more evident in anti-CD3-stimulated cells.
Altogether, the present findings might suggest that DC-derived NO is at least one
of the soluble factors regulating events, in the thymus, that follow recognition
of self- and allo-Ags.
PMID- 10779770
TI - Stat4 is expressed in activated peripheral blood monocytes, dendritic cells, and
macrophages at sites of Th1-mediated inflammation.
AB - Stat4 is a key transcription factor involved in promoting cell-mediated immunity,
whose expression in mature cells has been reported to be restricted to T and NK
cells. We demonstrate here, however, that Stat4 expression is not restricted to
lymphoid cells. In their basal state, monocytes do not express Stat4. Upon
activation, however, IFN-gamma- and LPS-treated monocytes and dendritic cells
express high levels of Stat4. Monocyte-expressed Stat4 in humans is
phosphorylated in response to IFN-alpha, but not IL-12. In contrast, the Th2
cytokines, IL-4 and IL-10, specifically down-regulate Stat4 expression in
activated monocytes, while having little effect on Stat6 expression. Moreover,
macrophages in synovial tissue obtained from patients with rheumatoid arthritis
express Stat4 in vivo, suggesting a potential role in a prototypical Th1-mediated
human disease. IFN-alpha-induced Stat4 activation in human monocytes represents a
previously unrecognized signaling pathway at sites of Th1 inflammation.
PMID- 10779771
TI - Cytoprotection of human umbilical vein endothelial cells against apoptosis and
CTL-mediated lysis provided by caspase-resistant Bcl-2 without alterations in
growth or activation responses.
AB - Graft endothelial cells are primary targets of host CTL-mediated injury in acute
allograft rejection. As an in vitro trial of gene therapy to reduce CTL-mediated
endothelial injury, we stably transduced early passage HUVEC with a caspase
resistant mutant form (D34A) of the anti-apoptotic gene Bcl-2. Bcl-2
transductants were compared with HUVEC transduced in parallel with an enhanced
green fluorescent protein (EGFP) gene. Both transduced HUVEC have equivalent
growth rates in complete medium and both show contact inhibition of growth.
However, compared with EGFP-transduced HUVEC, the Bcl-2-transduced cells are
resistant to the apoptotic effects of serum and growth factor withdrawal and are
also resistant to the induction of apoptosis by staurosporine or by ceramide,
with or without TNF. Transduced Bcl-2 did not reduce TNF-mediated NF-kappaB
activation or constitutive expression of class I MHC molecules. HUVEC expressing
D34A Bcl-2 were significantly more resistant to lysis by either class I
restricted alloreactive or PHA-redirected CTL than were HUVEC expressing EGFP. We
conclude that transduction of graft endothelial cells with D34A Bcl-2 is a
possible approach for reducing allograft rejection.
PMID- 10779772
TI - IL-6 receptor independent stimulation of human gp130 by viral IL-6.
AB - The genome of human herpes virus 8, which is associated with Kaposi's sarcoma,
encodes proteins with similarities to cytokines and chemokines including a
homologue of IL-6. Although the function of these viral proteins is unclear, they
might have the potential to modulate the immune system. For viral IL-6 (vIL-6),
it has been demonstrated that it stimulates IL-6-dependent cells, indicating that
the IL-6R system is used. IL-6 binds to IL-6R, and the IL-6/IL-6R complex
associates with gp130 which dimerizes and initiates intracellular signaling.
Cells that only express gp130 but no IL-6R cannot be stimulated by IL-6 unless a
soluble form of the IL-6R is present. This type of signaling has been shown for
hematopoietic progenitor cells, endothelial cells, and smooth muscle cells. In
this paper we show that purified recombinant vIL-6 binds to gp130 and stimulates
primary human smooth muscle cells. IL-6R fails to bind vIL-6 and is not involved
in its signaling. A Fc fusion protein of gp130 turned out to be a potent
inhibitor of vIL-6. Our data demonstrate that vIL-6 is the first cytokine which
directly binds and activates gp130. This property points to a possible role of
this viral cytokine in the pathophysiology of human herpes virus 8.
PMID- 10779773
TI - Cyclic nucleotide phosphodiesterase 3B is a downstream target of protein kinase B
and may be involved in regulation of effects of protein kinase B on thymidine
incorporation in FDCP2 cells.
AB - Wild-type (F/B), constitutively active (F/B*), and three kinase-inactive (F/Ba-,
F/Bb-, F/Bc-) forms of Akt/protein kinase B (PKB) were permanently overexpressed
in FDCP2 cells. In the absence of insulin-like growth factor-1 (IGF-1),
activities of PKB, cyclic nucleotide phosphodiesterase 3B (PDE3B), and PDE4 were
similar in nontransfected FDCP2 cells, mock-transfected (F/V) cells, and F/B and
F/B- cells. In F/V cells, IGF-1 increased PKB, PDE3B, and PDE4 activities
approximately 2-fold. In F/B cells, IGF-1, in a wortmannin-sensitive manner,
increased PKB activity approximately 10-fold and PDE3B phosphorylation and
activity ( approximately 4-fold), but increased PDE4 to the same extent as in F/V
cells. In F/B* cells, in the absence of IGF-1, PKB activity was markedly
increased ( approximately 10-fold) and PDE3B was phosphorylated and activated (3-
to 4-fold); wortmannin inhibited these effects. In F/B* cells, IGF-1 had little
further effect on PKB and activation/phosphorylation of PDE3B. In F/B- cells, IGF
1 activated PDE4, not PDE3B, suggesting that kinase-inactive PKB behaved as a
dominant negative with respect to PDE3B activation. Thymidine incorporation was
greater in F/B* cells than in F/V cells and was inhibited to a greater extent by
PDE3 inhibitors than by rolipram, a PDE4 inhibitor. In F/B cells, IGF-1-induced
phosphorylation of the apoptotic protein BAD was inhibited by the PDE3 inhibitor
cilostamide. Activated PKB phosphorylated and activated rPDE3B in vitro. These
results suggest that PDE3B, not PDE4, is a target of PKB and that activated PDE3B
may regulate cAMP pools that modulate effects of PKB on thymidine incorporation
and BAD phosphorylation in FDCP2 cells.
PMID- 10779774
TI - Characterization of human inducible costimulator ligand expression and function.
AB - The inducible costimulator (ICOS) is the newest member of the CD28/CD152 receptor
family involved in regulating T cell activation. We constructed a soluble-Ig
fusion protein of the extracellular domain of human ICOS and used it as a probe
to characterize expression patterns of the ICOS ligand (ICOSL). ICOSIg did not
bind to CD80- or CD86-transfected Chinese hamster ovary cell lines, demonstrating
that ICOSL is distinct from those ligands identified for CD28/CD152. ICOSIg
showed selective binding to monocytic and B cell lines, whereas binding was
undetectable on unstimulated monocytes and peripheral blood T and B cells.
Expression of ICOSL was induced on monocytes after integrin-dependent plastic
adhesion. Pretreatment of monocytes with mAb to the beta2-integrin subunit CD18
decreased adhesion and abolished ICOSL up-regulation but had no effect on CD80/86
(CD152 ligand (CD152L)) expression. Both ICOSL and CD152L were up-regulated on
monocytes by IFN-gamma but by distinct signaling pathways. Unlike CD152L
expression, ICOSL expression did not change when monocytes were differentiated
into dendritic cells (DCs) or after DCs were induced to mature by LPS, TNF-alpha,
or CD40 ligation. Addition of ICOSIg to allogeneic MLRs between DCs and T cells
reduced T cell proliferative responses but did so less efficiently than CTLA4Ig
(CD152Ig) did. Similarly, ICOSIg also blocked Ag-specific T cell proliferation to
tetanus toxoid. Thus, ICOSL, like CD80/86, is expressed on activated monocytes
and dendritic cells but is regulated differently and delivers distinct signals to
T cells that can be specifically inhibited by ICOSIg.
PMID- 10779776
TI - DO11.10 and OT-II T cells recognize a C-terminal ovalbumin 323-339 epitope.
AB - The OVA323-339 epitope recognized by DO11.10 (H-2d) and OT-II (H-2b) T cells was
investigated using amino- and carboxy-terminal truncations to locate the
approximate ends of the epitopes and single amino acid substitutions of OVA323
339 to identify critical TCR contact residues of the OVA323-339 peptide. DO11.10
and OT-II T cells are both specific for a C-terminal epitope whose core
encompasses amino acids 329-337. Amino acid 333 was identified as the primary TCR
contact residue for both cells, and amino acid 331 was found to be an important
secondary TCR contact residue; however, the importance of other secondary TCR
contact residues and peptide flanking residues differ between the cells.
Additional OVA323-339-specific clones were generated that recognized epitopes
found in the N-terminal end or in the center of the peptide. These findings
indicate that OVA323-339 can be presented by I-Ad in at least three binding
registers. This study highlights some of the complexities of peptide Ags such as
OVA323-339, which contain a nested set of overlapping T cell epitopes and MHC
binding registers.
PMID- 10779775
TI - MHC class II-bound self peptides from autoimmune MRL/lpr mice reveal potential T
cell epitopes for autoantibody production in murine systemic lupus erythematosus.
AB - The systemic lupus erythematosus-like syndrome in MRL/lpr mice involves high
titered IgG autoantibodies, particularly antinuclear Abs that target histones,
DNA, and RNA particles. Although T cell help is required for the generation of
antinuclear Abs, the epitopes recognized by such helper T cells are unknown. To
address this question, we isolated and sequenced self peptides bound by MHC class
II molecules from MRL/lpr mice. We identified a number of peptides that are not
seen in similar preparations from nonautoimmune C3H animals. The "abnormal"
peptide donors include histone, a protein component of a small nuclear
ribonucleoprotein, ribosomal proteins, and RNA processing enzymes. We postulate
that the peptides from these donors are T cell epitopes required for the
generation of the most frequent antinuclear Abs specificities seen in MRL/lpr
mice.
PMID- 10779777
TI - Accelerated proteasomal degradation of membrane Ig heavy chains.
AB - Membrane IgG H chains turn over considerably more rapidly than secretory Ig H
chains in the 18-81 A2 pre-B cell line. This rapid degradation occurs in
proteasomes. N-Glycosylated membrane Ig H chains accumulate in the endoplasmic
reticulum in the presence of proteasomal inhibitors, suggesting that
retrotranslocation and proteasomal degradation of membrane Ig H chains may be
closely coupled processes. Accelerated proteasomal degradation of membrane Ig H
chains was also observed in transfected nonlymphoid cells. At steady state, the
membrane form of the H chain associates more readily with Bip and calnexin than
its secretory counterpart. The preferential recognition of membrane, as opposed
to secretory, Ig H chains by some endoplasmic reticulum chaperones, may provide
an explanation for the accelerated proteasomal degradation of the former.
PMID- 10779778
TI - RGS molecule expression in murine B lymphocytes and ability to down-regulate
chemotaxis to lymphoid chemokines.
AB - Ag-mediated changes in B lymphocyte migration are important for normal immune
function, yet the mechanisms by which these changes occur are poorly defined.
Because chemokines direct many lymphocyte movements, molecules that regulate
signaling by G protein-coupled chemokine receptors are likely to participate in
Ag receptor-induced changes in cell migration. In this study, we have
investigated the expression pattern and activity in murine B cells of members of
the regulators of G protein signaling (RGS) family of molecules. We present the
sequence of mouse RGS1 and describe a novel short isoform of RGS3 that we term
RGS3s. Following in vivo activation by Ag, B cells rapidly up-regulate expression
of RGS1 and RGS2 while simultaneously decreasing expression of RGS3 and RGS14.
Anergic hen egg lysozyme autoantigen-binding B cells are also shown to have
slightly elevated RGS1 and RGS2 expression. CD40 signaling, by contrast, fails to
cause rapid up-regulation of RGS1 or RGS2. Using a transient transfection
approach in a mature B cell line, 2PK3, we demonstrate that RGS1 and RGS3s are
effective inhibitors of chemotaxis toward the lymphoid tissue chemokines stromal
cell-derived factor-1, B lymphocyte chemoattractant, and EBV-induced molecule 1
ligand chemokine, whereas RGS2 has a minimal effect on migration to these
chemokines. Together these findings support the conclusion that Ag-mediated
changes in RGS molecule expression are part of the mechanism by which Ag receptor
signaling regulates B cell migration within lymphoid tissues. The findings also
suggest important roles for additional G protein-mediated events in B cell
activation and tolerance.
PMID- 10779779
TI - Characterization of superantigen-induced clonal deletion with a novel clan III
restricted avian monoclonal antibody: exploiting evolutionary distance to create
antibodies specific for a conserved VH region surface.
AB - Evolution of the Ab system has yielded three clans of VH region genes that are
represented in almost every known higher species with an adaptive immune system.
These clans are defined by sequence homologies primarily in highly conserved
framework (FR) subdomains, which serve a scaffolding function maintaining the
conformation of loops responsible for Ag binding. Structural analyses indicate
that the VH FR1 and FR3 form a conserved composite exposed surface, which has
been implicated in interactions with B cell superantigens. To directly
investigate the expression of clan-defined supraclonal sets, we exploited the
evolutionary distance of the chicken immune system and the selection power of
phage display, to derive Abs diagnostic for clan III Ig. Using a specially
tailored immunization and selection strategy, we created recombinant avian single
chain Fv Abs specific for the clan III products, including those from the human
VH3 family, and the analogous murine 7183, S107, J606, X24, and DNA4 families,
and binding was competitive with natural B cell superantigens. The archetype, LJ
26, was demonstrated to recognize a clan-specific surface expressed in diverse
mammalian, and also the Xenopus and chicken, immune systems. In flow-cytometric
studies with LJ-26, we found that treatment of heterozygous T15i transgenic mice
with a model B cell superantigen induced a clan III-restricted clonal deletion.
These studies demonstrate the utility of a novel recombinant serologic reagent to
study the composition of the B cell compartment and also the consequences of B
cell superantigen exposure.
PMID- 10779780
TI - Molecular mechanisms of target recognition in an innate immune system:
interactions among factor H, C3b, and target in the alternative pathway of human
complement.
AB - In the alternative pathway of complement (APC) factor H is the primary control
factor involved in discrimination between potential pathogens. The APC deposits
C3b on possible Ags, and the interaction with factor H determines whether the
initial C3b activates the APC. Factor H is composed of a linear array of 20
homologous short consensus repeats (SCR) domains with many functional sites.
Three of these sites are involved in binding C3b and regulating complement
activation; others bind to sialic acid and/or heparin and are responsible for
host recognition. Using site-directed mutations we have examined the
contributions of each of these sites to target discrimination and to functional
activities of factor H. Decay acceleration by SCR1-4 of C3/C5 convertases bound
to nonactivators was strongly dependent on SCR domains 11-15 and 16-20. Loss of
these regions caused a 97% loss of activity, with SCR16-20 being the most
critical (>90% loss). On APC activators the pattern of site usage was different
and unique on each. On yeast, deletion of the 10 C-terminal domains (SCR11-20)
had no effect on specific activity. On rabbit erythrocytes, this deletion caused
loss of 75% of the specific activity. An examination of binding affinity to C3b
on the four cell types demonstrated that factor H exhibits a unique pattern of
SCR involvement on each cell. The results reveal a complex molecular mechanism of
discrimination between microbes and host in this ancient innate defense system
and help explain the different rates and intensities of APC activation on
different biological particles.
PMID- 10779781
TI - Biosynthesis and posttranslational regulation of human IL-12.
AB - IL-12 is a heterodimeric proinflammatory cytokine consisting of a light alpha
chain, formerly defined as p35, disulfide-linked to a heavier beta-chain,
formerly defined as p40. The beta-chain is also produced in large excess in a
free form, and disulfide-linked beta-chain homodimers with anti-inflammatory
effects are produced in the mouse. We analyzed the biosynthesis and glycosylation
of IL-12 in human monocytes, and in a cell line stably transfected with IL-12
alpha and beta genes (P5-0.1). The IL-12 heterodimer and free beta-chain were
immunoprecipitated from supernatants and cell lysates of metabolically labeled
cells and resolved in SDS-PAGE. Whereas the beta-chain showed similar pI pattern
whether in the free form or associated in the heterodimer, either in the secreted
or intracellular form, the alpha-chain in the secreted heterodimer was much more
acidic than that present in the intracellular heterodimer. Deglycosylation
experiments with neuraminidase and Endo-F combined with two-dimensional PAGE of
single bands of the intracellular vs extracellular IL-12 heterodimer revealed
that the alpha-chain was extensively modified with sialic acid adducts to N
linked oligosaccharides before secretion. N-glycosylation inhibition by
tunicamycin (TM) did not alter free beta-chain secretion, while preventing the IL
12 heterodimer assembling and secretion. Pulse-chase experiments indicated that
IL-12 persists intracellularly for a long period as an immature heterodimer, and
that glycosylation is the regulatory step that determines its secretion. beta
chain disulfide-linked homodimers were observed in TM-treated P5-0.1 cells, but
in neither TM-treated nor untreated monocytes.
PMID- 10779782
TI - A switch in distinct I kappa B alpha degradation mechanisms mediates constitutive
NF-kappa B activation in mature B cells.
AB - Inducible activation of cytoplasmic NF-kappa B/Rel transcription factors occurs
via proteasome-dependent degradation of an associated inhibitor, termed I kappa B
alpha. Mature B lymphocytes constitutively express nuclear NF-kappa B, which is
important for their long-term survival. The intrinsic mechanisms by which B cells
constitutively activate NF-kappa B are unknown. In this paper we demonstrate that
maintenance of NF-kappa B activity in primary B cells is mediated by a novel
calcium-dependent, but proteasome-independent, mechanism. Moreover, we show that
differentiation of conditionally transformed pre-B cells is accompanied by a
switch from proteasome-dependent to proteasome-independent degradation of I kappa
B alpha. Our findings indicate that I kappa B alpha degradation mechanisms are
dynamic during B cell development, and ultimately establish constitutive NF-kappa
B activity in mature B lymphocytes.
PMID- 10779783
TI - Neutralization of maternal IL-4 modulates congenital protozoal transmission:
comparison of innate versus acquired immune responses.
AB - IL-4 levels were modulated in mice to test the hypothesis that induction of a
maternal type 1 response would decrease the frequency of congenital Neospora
caninum transmission. This hypothesis tested the relationship between IL-4 and
both innate and adaptive immunity utilizing two basic experimental designs. In
the first, maternal IL-4 was neutralized with mAb during pregnancy in naive mice
concomitant with initial, virulent infection. In the second, maternal IL-4 was
neutralized before pregnancy concomitant with a priming inoculation consisting of
live, avirulent N. caninum tachyzoites followed by virulent challenge during
subsequent gestation. In mice that were naive before pregnancy, neutralization of
IL-4 during gestational challenge did not result in decreased congenital
transmission as measured by PCR performed on 1-day-old neonatal mice. In mice
that were primed and modulated before pregnancy, congenital transmission from
gestational challenge was significantly decreased compared with control mice.
Reduction in transmission constituted a decrease in the numbers of mice
transmitting N. caninum and a lower frequency of transmission by individual dams
(p < 0.05). Decreased congenital transmission was associated with significantly
lower levels of maternal splenocyte IL-4 secretion, lower IL-4 mRNA levels, and
higher levels of IFN-gamma secretion. Protected mice had significantly decreased
Neospora-specific IgG1 compared with nonmodulated mice. These studies define a
relationship between maternal Ag-specific immunity and the frequency of
congenital transmission and demonstrate that modulation of type 2 cytokine
responses can change the frequency of congenital protozoal transmission.
PMID- 10779784
TI - Human cytomegalovirus strain-dependent changes in NK cell recognition of infected
fibroblasts.
AB - NK cells play a key role in the control of CMV infection in mice, but the
mechanism by which NK cells can recognize and kill CMV-infected cells is unclear.
In this study, the modulation of NK cell susceptibility of human CMV (hCMV)
infected cells was examined. We used a human lung and a human foreskin fibroblast
cell line infected with clinical isolates (4636, 13B, or 109B) or with laboratory
strains (AD169, Towne). The results indicate that all three hCMV clinical
isolates confer a strong NK resistance, whereas only marginal or variable effects
in the NK recognition were found when the laboratory strains were used. The same
results were obtained regardless of the conditions of infection, effector cell
activation status, cell culture conditions, and/or donor-target cell
combinations. The NK cell inhibition did not correlate with HLA class I
expression levels on the surface of the target cell and was independent of the
leukocyte Ig-like receptor-1, as evaluated in Ab blocking experiments. No
relevant changes were detected in the adhesion molecules ICAM-I and LFA-3
expressed on the cell surface of cells infected with hCMV clinical and laboratory
strains. We conclude that hCMV possesses other mechanisms, related neither to
target cell expression of HLA-I or adhesion molecules nor to NK cell expression
of leukocyte Ig-like receptor-1, that confer resistance to NK cell recognition.
Such mechanisms may be lost during in vitro passage of the virus. These results
emphasize the differences between clinical hCMV isolates compared with laboratory
strains.
PMID- 10779785
TI - Requirement of endogenous stem cell factor and granulocyte-colony-stimulating
factor for IL-17-mediated granulopoiesis.
AB - IL-17 is a novel, CD4+ T cell-restricted cytokine. In vivo, it stimulates
hematopoiesis and causes neutrophilia consisting of mature granulocytes. In this
study, we show that IL-17-mediated granulopoiesis requires G-CSF release and the
presence or induction of the transmembrane form of stem cell factor (SCF) for
optimal granulopoiesis. However, IL-17 also protects mice from G-CSF
neutralization-induced neutropenia. G-CSF neutralization completely reversed IL
17-induced BM progenitor expansion, whereas splenic CFU-GM/CFU-granulocyte
erythrocyte-megakaryocyte-monocyte was only reduced by 50% in both Sl/Sld and
littermate control mice. Thus, there remained a significant SCF/G-CSF-independent
effect of IL-17 on splenic granulopoiesis, resulting in a preservation of mature
circulating granulocytes. IL-17 is a cytokine that potentially interconnects
lymphocytic and myeloid host defense and may have potential for therapeutic
development.
PMID- 10779786
TI - Evidence for human CD4+ T cells in the CD1-restricted repertoire: derivation of
mycobacteria-reactive T cells from leprosy lesions.
AB - Both the CD4-CD8- (double negative) and CD4-CD8+ T cell lineages have been shown
to contain T cells which recognize microbial lipid and glycolipid Ags in the
context of human CD1 molecules. To determine whether T cells expressing the CD4
coreceptor could recognize Ag in the context of CD1, we derived CD4+ T cell lines
from the lesions of leprosy patients. We identified three CD4+ Mycobacterium
leprae-reactive, CD1-restricted T cell lines: two CD1b restricted and one CD1c
restricted. These T cell lines recognize mycobacterial Ags, one of which has not
been previously described for CD1-restricted T cells. The response of CD4+ CD1
restricted T cells, unlike MHC class II-restricted T cells, was not inhibited by
anti-CD4 mAb, suggesting that the CD4 coreceptor does not impact positive or
negative selection of CD1-restricted T cells. The CD4+ CD1-restricted T cell
lines produced IFN-gamma and GM-CSF, the Th1 pattern of cytokines required for
cell-mediated immunity against intracellular pathogens, but no detectable IL-4.
The existence of CD4+ CD1-restricted T cells that produce a Th1 cytokine pattern
suggests a contributory role in immunity to mycobacterial infection.
PMID- 10779787
TI - Linkage of foreign carrier protein to a self-tumor antigen enhances the
immunogenicity of a pulsed dendritic cell vaccine.
AB - The unique Ag-presenting capabilities of dendritic cells (DCs) make them
attractive vehicles for the delivery of therapeutic cancer vaccines. While tumor
Ag-pulsed DC vaccination has shown promising results in a variety of murine tumor
models and early clinical trials, the optimal form of tumor Ag for use in DC
pulsing has not been determined. We have studied DC vaccination using alternative
forms of a soluble protein tumor Ag, the tumor-specific Ig idiotype (Id)
expressed by a murine B cell lymphoma. Vaccination of mice with Id-pulsed DCs was
able to induce anti-Id Abs only when the Id was modified to constitute a hapten
carrier system. DCs pulsed with Id proteins modified to include foreign constant
regions, foreign constant regions plus GM-CSF, or linkage to keyhole limpet
hemocyanin (KLH) carrier protein were increasingly potent in their ability to
elicit anti-Id Abs. Vaccination with Id-KLH-pulsed DCs induced tumor-protective
immunity superior to that obtained with Id-KLH plus a chemical adjuvant, and
protection was not dependent upon effector T cells. Rather, protection was
associated with the induction of high titers of anti-Id Abs of the IgG2a
subclass, characteristic of a Th1 response. These findings have implications for
the design of therapeutic Ag-pulsed DC vaccines for cancer immunotherapy in
humans.
PMID- 10779788
TI - Synthetic endotoxin-binding peptides block endotoxin-triggered TNF-alpha
production by macrophages in vitro and in vivo and prevent endotoxin-mediated
toxic shock.
AB - Lipid A, the conserved portion of endotoxin, is the major mediator of septic
shock; therefore, endotoxin-neutralizing molecules could have important clinical
applications. Here we show that peptides derived from Limulus anti-LPS factor
(LALF), bactericidal/permeability increasing protein (BPI) and endotoxin-binding
protein, bind to lipid A and block the recombinant LALF/lipid A interaction in
vitro. Because their neutralizing capacity in vitro as well as in vivo has been
limited, we created hybrid peptides comprising two endotoxin-binding domains. The
hybrid molecule LL-10-H-14, containing endotoxin-binding domains from LALF and
endotoxin-binding protein, turned out to be the most active peptide within the
series of peptides tested here to inhibit the CD14/lipid A interaction and is
able in vitro to block the endotoxin-induced TNF-alpha release of murine
macrophages up to 90%. Furthermore, LL-10-H-14 not only reduced peak serum levels
of TNF-alpha of mice when preinjected but also reduced TNF-alpha levels when
given 15 min after the endotoxin challenge. As compared with other peptides, only
LL-10-H-14 is able to strongly decrease endotoxin-stimulated TNF-alpha release by
human macrophage cell lines as well as by PBMC. Furthermore, the hybrid peptide
is protective against endotoxin-provoked lethal shock. As such, LL-10-H-14 could
have prophylactic and/or therapeutic properties in humans for the management of
septic shock.
PMID- 10779789
TI - Regulation and role of IFN-gamma in the innate resistance to infection with
Chlamydia pneumoniae.
AB - By using mice genomically lacking IFN-gammaR, IL-12, perforin, and recombination
activating gene-1 (RAG-1), we analyzed the regulation and importance of IFN-gamma
in the control of infection with Chlamydia pneumoniae. IL-12 participates in
resistance of mice to C. pneumoniae, probably by regulating the protective levels
of IFN-gamma mRNA. In turn, IFN-gamma is necessary for the increased IL-12p40
mRNA accumulation that occurs in lungs during infection with C. pneumoniae,
suggesting a positive feedback regulation between these two cytokines. In
experiments including RAG-1-/-/IFN-gammaR-/- mice we showed that IFN-gamma
produced by innate cells controls the bacterial load and is necessary for the
increased accumulation of transcripts for enzymes controlling high output NO
release (inducible NO synthase), superoxide production (gp-91 NADPH oxidase), and
catalysis of tryptophan (indoleamine 2, 3-dioxygenase (IDO)), mechanisms probably
related to bacterial killing. Adaptive immune responses diminish the levels of
IFN-gamma and IL-12 mRNA and thereby the levels of inducible NO synthase, IDO,
and gp91 NADPH oxidase transcripts. By using RAG-1-/-/perforin-/- mice, we
excluded the overt participation of NK cell cytotoxicity in the control of C.
pneumoniae. However, NK cells and probably other innate immune cells release IFN
gamma during the bacterial infection.
PMID- 10779790
TI - In BALB/c mice, IL-4 production during the initial phase of infection with
Leishmania major is necessary and sufficient to instruct Th2 cell development
resulting in progressive disease.
AB - In contrast to intact BALB/c mice, BALB/c mice rendered deficient in Vbeta4+ CD4+
T cells develop a Th1 response to infection with Leishmania major and are
resistant. Vbeta4-deficient BALB/c mice are unable to generate the early IL-4
transcription occurring in Vbeta4 Valpha8 CD4+ T cells of BALB/c mice within 1
day of infection. Here we demonstrate that treatment of Vbeta4-deficient BALB/c
mice with IL-4 during the first 64 h after infection instructs Th2 cell
development and susceptibility to infection. The demonstrated inability of IL-4
to reverse the resistant phenotype of BALB/c mice treated with anti-CD4 mAb the
day before infection suggest that these effects of IL-4 require its interaction
with CD4+ T cells. In contrast to draining lymph node cells from BALB/c mice,
cells from Vbeta4-deficient BALB/c mice remain responsive to IL-12 following
infection. Strikingly, administration of IL-4 to Vbeta4-deficient BALB/c mice
renders their lymph node cells unresponsive to IL-12 by down-regulating IL-12R
beta2-chain expression. This study directly demonstrates that in BALB/c mice IL-4
is necessary and sufficient to initiate the molecular events steering Th2 cell
maturation and susceptibility to L. major.
PMID- 10779791
TI - Phenotype and functions of brain dendritic cells emerging during chronic
infection of mice with Toxoplasma gondii.
AB - During chronic infection of mice with Toxoplasma gondii, gene message for IL
12p40, CD86, and the potassium channel Kv1.3 was detected in brain mononuclear
cells, suggesting the presence of dendritic cells (DC) in the CNS. Consistently,
cells bearing the DC markers CD11c and 33D1 were localized at inflammatory sites
in the infected brain. The number of isolated CD11c+ brain cells increased until
peak inflammation. The cells exhibited the surface phenotype of myeloid DC by
coexpressing 33D1 and F4/80, little DEC-205, and no CD8alpha. These brain DC were
mature, as indicated by high-level expression of MHC class II, CD40, CD54, CD80,
and CD86. They triggered Ag-specific and primary allogeneic T cell responses at
very low APC/T cell ratios. Among mononuclear cells from encephalitic brain, DC
were the main producers of IL-12. Evidence for a parasite-dependent development
of DC from CNS progenitors was obtained in vitro: after inoculation of primary
brain cell culture with T. gondii, IL-12-secreting dendriform cells emerged, and
DC marker genes were expressed. Different stimuli elicited the generation and
maturation of brain DC: neutralization of parasite-induced GM-CSF prevented
outgrowth of dendriform cells and concomitant release of IL-12. IL-12 production
was up-regulated by external IFN-gamma but was stopped by inhibiting parasite
replication. Consistently, DC isolated from GM-CSF-treated brain cell culture
were activated to secrete IL-12 by exposure to parasite lysate. In sum, these
results demonstrate T. gondii-induced expansion and functional maturation of DC
in the CNS and, thus, highlight a mechanism that may contribute to the chronicity
of the host response.
PMID- 10779792
TI - Biological correlates of capsular (quellung) reactions of Cryptococcus
neoformans.
AB - The capsular swelling or quellung reaction was reported almost 100 years ago and
described the effect of Abs on the appearance of microbial capsules. Despite
widespread use to assess Ab binding to capsules, relatively little is known as to
the mechanism of this effect or its biological consequences. The fungus
Cryptococcus neoformans is an attractive system to study capsule reactions
because it has a large polysaccharide capsule that is readily visible by light
microscopy. When viewed by differential interference contrast microscopy, binding
of mAb to C. neoformans cells produced two distinct capsular reactions that
depended on the Ab epitope specificity and the yeast serotype. In the first
pattern, termed "rim," the capsule appears transparent with a highly refractive
outer edge. In the second pattern, termed "puffy," the capsule appears opaque and
lacks a highly refractive outer rim. mAbs that bind with a rim pattern suppress
the overall rate of C3 deposition on the yeast via the classical and alternative
complement pathways. In contrast, mAbs that bind with a puffy pattern do not
affect C3 deposition. Protective and nonprotective IgM mAbs produce rim and puffy
patterns, respectively. These results indicate that: 1) capsule reactions are a
consequence of Ab-induced changes in capsular refractive index; 2) the type of
capsule reaction depends on the Ab specificity; and 3) Ab-induced changes in
refractive index correlate with biological activities important for host defense
against C. neoformans. Our results provide the first evidence associating
distinct capsule reaction patterns with Ab biological activity.
PMID- 10779793
TI - Intersection of group I CD1 molecules and mycobacteria in different intracellular
compartments of dendritic cells.
AB - Human CD1a, CD1b, and CD1c molecules can present mycobacterial glycolipids to T
cells. Because phagosomes containing viable mycobacteria represent early
endosomal compartments, we studied where mycobacterial glycolipids intersect with
CD1 molecules in infected APC. CD1b and CD1c, but not CD1a, localized to late
endosomes/lysosomes. CD1a and CD1c were predominantly expressed on the cell
surface and in mycobacterial phagosomes of the early endosomal stage. In
contrast, CD1b was present in a subset of mycobacterial phagosomes representing
mature phagolysosomes. Released mycobacterial glycolipids including
lipoarabinomannan and phosphatidylinositol mannosides were transported from the
phagosome into late endosomes/lysosomes and to uninfected bystander cells. The
macrophage mannose receptor, which has been implicated in glycolipid uptake by
APC for CD1b-mediated presentation, was absent from mycobacterial phagosomes and
may therefore not be involved in trafficking of glycolipids between phagosomes
and late endosomes/lysosomes. In conclusion, all three CD1 molecules have access
to mycobacteria and glycolipids thereof, but at different intracellular sites.
This allows sampling by CD1a, CD1b, and CD1c of mycobacterial glycolipids from
different intracellular sites of the infected cell, which has important
implications for processing and presentation of such Ags during mycobacterial
infections.
PMID- 10779794
TI - Up-regulation of VCAM-1 and differential expansion of beta integrin-expressing T
lymphocytes are associated with immunity to pulmonary Mycobacterium tuberculosis
infection.
AB - Immune responses rely on an intricate system of adhesion molecules to coordinate
the homing and retention of lymphocytes in both secondary lymphoid tissues and at
sites of infection. To define the events associated with pulmonary immune
responses, the expression of endothelial addressins and integrins on T cells was
analyzed during Mycobacterium tuberculosis infection. In infected lung,
expression of endothelial VCAM-1, but not mucosal addressin cell adhesion
molecule-1, was up-regulated from 4 wk postinfection and persisted to at least 12
wk. Subsequent analysis of the corresponding integrins expressed on lung CD4+ and
CD8+ T cells revealed an accumulation of beta1high/beta7-/low, and to a lesser
extent beta7high, integrin-expressing T cells during infection. Examination of
integrin heterodimers showed that while alpha4 integrin was predominantly
expressed on beta1high/beta7-/low cells, alphaE integrin was primarily associated
with beta7high. The majority of activated/memory T cells recruited during
infection expressed high levels of beta1 integrin and undetectable or low levels
of beta7 integrin. These T cells were capable of producing IFN-gamma, a cytokine
crucial for controlling M. tuberculosis infection. Rapid expansion of beta1high,
beta7-, and beta7high T cell populations in the lung upon secondary mycobacterial
infection indicates the participation of these populations in the acquired immune
response to the infection. Furthermore, treatment of infected mice with mAb to
alpha4 or alpha4beta7 integrin led to a reduction in lymphocytes and increase in
granulocytes in the pulmonary infiltrate. These results reveal a crucial role for
adhesion molecules in the generation of an effective pulmonary immune response to
M. tuberculosis infection.
PMID- 10779795
TI - Apoptotic thymocyte clearance in scavenger receptor class A-deficient mice is
apparently normal.
AB - Studies of apoptotic cell uptake by phagocytes in vitro have implicated a number
of different receptors capable of mediating ingestion. However, there is
currently little evidence for involvement of any of these candidate receptors in
vivo. Previously, we have shown by the use of a blocking mAb against the class A
scavenger receptor (SR-A) and thymic macrophages prepared from SR-A null mice,
that this receptor is responsible for approximately 50% of the uptake of
apoptotic thymocytes in vitro. In this study we have investigated the frequency
of dying cells in the thymus of mice lacking SR-A. Our inability to demonstrate
increased frequencies of nonphagocytosed Annexin V+, TUNEL+, or propidium iodide+
apoptotic thymocytes suggests there is no deficiency in apoptotic thymocyte
clearance in these mice. Even when the rate of thymocyte apoptosis was increased
by exposure of receptor-deficient mice to gamma irradiation, we did not detect a
difference in the numbers of dying cells compared with similarly treated wild
type animals. This provides the first direct evidence of redundancy in apoptotic
cell clearance mechanisms in vivo.
PMID- 10779796
TI - Ley/H: an endothelial-selective, cytokine-inducible, angiogenic mediator.
AB - Endothelial cells (ECs) are key participants in angiogenic processes that
characterize tumor growth, wound repair, and inflammatory diseases, such as human
rheumatoid arthritis (RA). We and others have shown that EC molecules, such as
soluble E-selectin, mediate angiogenesis. Here we describe an EC molecule, Lewisy
6/H-5-2 glycoconjugate (Ley/H), that shares some structural features with the
soluble E-selectin ligand, sialyl Lewisx (sialyl Lex). One of the main previously
recognized functions of Lewisy is as a blood group glycoconjugate. Here we show
that Ley/H is rapidly cytokine inducible, up-regulated in RA synovial tissue,
where it is cell-bound, and up-regulated in the soluble form in angiogenic RA
compared with nonangiogenic osteoarthritic joint fluid. Soluble Ley/H also has a
novel function, for it is a potent angiogenic mediator in both in vitro and in
vivo bioassays. These results suggest a novel paradigm of soluble blood group Ags
as mediators of angiogenic responses and suggest new targets for therapy of
diseases, such as RA, that are characterized by persistent neovascularization.
PMID- 10779797
TI - IL-6 is required for the development of Th1 cell-mediated murine colitis.
AB - Proinflammatory cytokines have been demonstrated to play a crucial role in the
pathogenesis of Crohn's disease. Among those cytokines, strong expression of IL-6
has been repeatedly demonstrated. To examine the role for IL-6 in the
pathogenesis of Crohn's disease, we introduced anti-IL-6R mAb to a murine model
of colitis. Colitis was induced in C.B-17-scid mice transferred with CD45RBhigh
CD4+ T cells from BALB/c mice. Anti-IL-6R mAb or rat IgG was administered weekly
after T cell transfer. ICAM-1 and VCAM-1 expression were analyzed by
immunohistochemistry. Colonic cytokine expression was determined by RT-PCR. Mice
treated with mAb showed normal growth, whereas controls lost weight. The average
colitis score was 0.64 for mAb-treated mice and 1.80 for controls. T cell
expansion in treated mice was less remarkable than in the controls. Colonic ICAM
1 and VCAM-1 expression were markedly suppressed by mAb. IFN-gamma, TNF-alpha,
and IL-1beta mRNA were reduced by the treatment. The results presented here show
a crucial role for IL-6 in the pathogenesis of murine colitis and suggest a
therapeutic potential of anti-IL-6R mAb for treatment of human Crohn's disease.
PMID- 10779798
TI - Long-term survival of hamster hearts in presensitized rats.
AB - We transplanted hamster hearts into rats that had been sensitized to hamster
cardiac grafts 5 days earlier as a model for discordant xenotransplantation.
Sensitized rats had high serum levels of elicited anti-donor IgM and IgG that
caused hyperacute rejection. Transient complement inhibition with cobra venom
factor (CVF) plus daily and continuing cyclosporin A (CyA) prevented hyperacute
rejection. However, grafts underwent delayed xenograft rejection (DXR). DXR
involved IgG and associated Ab-dependent cell-mediated rejection, because
depletion of IgG or Ab-dependent cell-mediated rejection-associated effector
cells prolonged graft survival and the serum-mediated Ab-dependent cell-mediated
cytotoxicity in vitro. Blood exchange in combination with CVF/CyA treatment
dramatically decreased the level of preexisting Abs, but DXR still occurred in
association with the return of Abs. Splenectomy and cyclophosphamide acted
synergistically to delay Ab return, and when combined with blood exchange/CVF/CyA
facilitated long-term survival of grafts. These grafts survived in the presence
of anti-donor IgM, IgG, and complement that precipitated rejection of naive
hearts, indicating that accommodation (survival in the presence of anti-graft Abs
and complement) had occurred. We attribute the long-term survival to the removal
of preexisting anti-donor Abs and therapy that attenuated the rate of Ab return.
Under such conditions, the surviving hearts showed expression in endothelial
cells and smooth muscle cells of protective genes and an intragraft Th2 immune
response. Th2 responses and protective genes are associated with resistance to
IgM- and IgG-mediated, complement-dependent and -independent forms of rejection.
PMID- 10779799
TI - Kinetics and mechanism of ATP-dependent IL-1 beta release from microglial cells.
AB - Endotoxin-dependent release of IL-1 beta from mouse microglial cells is a very
inefficient process, as it is slow and leads to accumulation of a modest amount
of extracellular cytokine. Furthermore, secreted IL-1 beta is mostly in the
procytokine unprocessed form. Addition of extracellular ATP to LPS-primed
microglia caused a burst of release of a large amount of processed IL-1 beta. ATP
had no effect on the accumulation of intracellular pro-IL-1 beta in the absence
of LPS. In LPS-treated cells, ATP slightly increased the synthesis of pro-IL-1
beta. Optimal ATP concentration for IL-1 beta secretion was between 3 and 5 mM,
but significant release could be observed at concentrations as low as 1 mM. At
all ATP concentrations IL-1 beta release could be inhibited by increasing the
extracellular K+ concentration. ATP-dependent IL-1 beta release was also
inhibited by 90 and 60% by the caspase inhibitors YVAD and DEVD, respectively.
Accordingly, in ATP-stimulated microglia, the p20 proteolytic fragment derived
from activation of the IL-1-beta-converting enzyme could be detected by
immunoblot analysis. These experiments show that in mouse microglial cells
extracellular ATP triggers fast maturation and release of intracellularly
accumulated IL-beta by activating the IL-1-beta-converting enzyme/caspase 1.
PMID- 10779800
TI - Genetic factors determine the contribution of leukotrienes to acute inflammatory
responses.
AB - Leukotrienes (LT) are potent lipid mediators synthesized by the 5-lipoxygenase
pathway of arachidonic acid (AA) metabolism. LT have been implicated in a broad
spectrum of inflammatory processes. To investigate the influence of genetic
factors on the contribution of LT to acute inflammation, we generated congenic 5
lipoxygenase-deficient 129, C57BL/6 (B6), and DBA/1Lac (DBA) mouse lines. Topical
application of AA evoked a vigorous inflammatory response in 129 and DBA mice,
whereas only a modest response was seen in B6 animals. The response to AA in 129
and DBA strains is LT dependent. In contrast, LT make little contribution to this
response in B6 mice. AA-induced inflammation in B6 mice is prostanoid dependent,
since this response was substantially reduced by treating B6 mice with a
cyclooxygenase inhibitor. These data suggest that prostanoids are essential for
AA-induced cutaneous inflammation in B6 mice, whereas LT are the major mediators
of this response in 129 and DBA strains. In contrast, the response to AA in the
peritoneal cavity is robust in the 129 and B6 strains, but was significantly
blunted in DBA mice, showing that strain differences in the response to AA are
tissue specific. Variations in these and other experimental models of
inflammation appear to correlate directly with the ability of a particular mouse
strain and a specific tissue to respond to LT, specifically LTC4. Taken together,
these findings indicate that the relative contribution of prostanoids and LT to
inflammatory responses is variable not only between strains but also between
different tissues within these inbred mouse lines.
PMID- 10779801
TI - Secretory phospholipases A2 induce beta-glucuronidase release and IL-6 production
from human lung macrophages.
AB - Secretory phospholipases A2 (sPLA2s) are a group of extracellular enzymes that
release fatty acids at the sn-2 position of phospholipids. Group IIA sPLA2 has
been detected in inflammatory fluids, and its plasma level is increased in
inflammatory diseases. To investigate a potential mechanism of sPLA2-induced
inflammation we studied the effect of group IA (from cobra venom) and group IIA
(human synovial) sPLA2s on human macrophages. Both sPLA2s induced a concentration
and Ca2+-dependent, noncytotoxic release of beta-glucuronidase (16.2 +/- 2.4%
and 13.1 +/- 1.5% of the total content with groups IA and IIA, respectively).
Both sPLA2s also increased the rate of secretion of IL-6 and enhanced the
expression of IL-6 mRNA. Preincubation of macrophages with inhibitors of the
hydrolytic activity of sPLA2 or cytosolic PLA2 did not influence the release of
beta-glucuronidase. Incubation of macrophages with p-aminophenyl-mannopyranoside
BSA (mp-BSA), a ligand of the mannose receptor, also resulted in beta
glucuronidase release. However, while preincubation of macrophages with mp-BSA
had no effect on beta-glucuronidase release induced by group IIA sPLA2, it
enhanced that induced by group IA sPLA2. A blocking Ab anti-mannose receptor
inhibited both mp-BSA- and group IIA-induced beta-glucuronidase release. Taken
together, these data indicate that group IA and IIA sPLA2s activate macrophages
with a mechanism independent from their enzymatic activities and probably related
to the activation of the mannose receptor or sPLA2-specific receptors. The
secretion of enzymes and cytokines induced by sPLA2s from human macrophages may
play an important role in inflammation and tissue damage associated with the
release of sPLA2s.
PMID- 10779802
TI - IFN-gamma and TNF regulate macrophage expression of the chemotactic S100 protein
S100A8.
AB - The murine calcium-binding protein S100A8 is a potent chemoattractant for
neutrophils and monocytes in vivo and in vitro but may also play a protective
role. We show that the kinetics of induction of S100A8 mRNA in elicited murine
macrophages (Mac) by LPS, IFN-gamma, and TNF were distinct from the C-C
chemokines monocyte chemoattractant protein-1 (MCP-1), macrophage-inflammatory
protein-1alpha (MIP-1alpha), and RANTES. Monomeric S100A8 was predominantly
secreted. IFN substantially increased S100A8 mRNA levels after 1 h with optimal
induction after 12 h; induction by TNF was slower and more sustained. TNF did not
up-regulate MCP-1 and MIP-1alpha mRNA in these cells. Luciferase reporter assays
confirmed that LPS and IFN induce S100A8 gene transcription and mRNA in LPS
treated Mac showed little decay over 16 h, whereas transcripts induced by IFN and
TNF were markedly less stable. Newly synthesized proteins may be required for
mRNA transcription and stabilization in response to LPS. S100A9 associates with
A8 in neutrophils, but was not coinduced with S100A8. S100A8 gene induction in
Mac stimulated with LPS and IFN may be modulated by mobilization of intracellular
Ca2+ concentration from distinct intracellular stores and/or the extracellular
compartment and by distinct pathways involving protein kinase C and leading to
activation of mitogen-activated protein kinase.
PMID- 10779803
TI - The T cell repertoire selected in vitro against EBV: diversity, specificity, and
improved purification through early IL-2 receptor alpha-chain (CD25)-positive
selection.
AB - Polyclonal T cell lines specific for EBV proteins have proved efficient in
preventing EBV-related immunoblastic lymphoma after allogeneic bone marrow
transplantation. To gain insight into the composition of the EBV-specific T cell
repertoire that ensured patient protection, we performed for the first time an
extensive characterization of eight cytotoxic T cell lines selected in vitro
against EBV-transformed autologous lymphoblastoid cell lines (BLCL). These T cell
lines consist of 50-100 distinct T cell clones, of which 32-96% are specific for
autologous BLCL. Moreover, we demonstrate that reactivities against only five EBV
proteins (BZLF1, BMLF1, EBNA-3A, EBNA-3C, and LMP2) cover 86% (32/37) of the
specificities detected. In addition, we describe an improved method of T cell
harvesting using a CD25 selection procedure which reduces the time required to
obtain specific T cells and improves the purity of EBV-specific T cells, thus
showing promise for use in adoptive transfer protocols.
PMID- 10779804
TI - Baseline airway hyperreactivity in A/J mice is not mediated by cells of the
adaptive immune system.
AB - Human asthma is characterized by increased airway hyperreactivity to a variety of
bronchoconstricting agents. Aberrant type 2 immune responses in the lung have
been associated with airway hyperreactivity in both human asthma and in murine
models of allergic airways disease. Despite their intrinsically elevated basal
airway reactivity to smooth muscle constricting agents, A/J mice demonstrated no
inherent inflammatory cell infiltration nor elevation of type 2 cytokines in the
lung. Crossed bone marrow reconstitution experiments between A/J and MHC congenic
B10.A mice revealed enhanced airway reactivity only in A/J recipients,
irrespective of whether they had been reconstituted with A/J or B10. A
hemopoietic cells. Further, A/J-derived bone marrow cells did not affect the
reactivity of B10.A recipients. Although mice on RAG-deficient and IL-4-deficient
backgrounds demonstrate substantial abrogation of allergen-induced airway
hyperreactivity, these gene deletions had no impact on the elevated baseline
reactivity when backcrossed onto A/J mice. Thus, in these mice, basal airway
hyperreactivity is maintained independently of type 2 immunity induced by
allergens.
PMID- 10779805
TI - Differential role of Fas/Fas ligand interactions in cytolysis of primary and
metastatic colon carcinoma cell lines by human antigen-specific CD8+ CTL.
AB - We have previously identified mutated ras peptides reflecting the glycine to
valine substitution at position 12 as HLA-A2-restricted, CD8+ CTL neo-epitopes.
CTL lines produced against these peptide epitopes lysed the HLA-A2+ Ag-bearing
SW480 primary colon adenocarcinoma cell line, although IFN-gamma treatment of the
targets was necessary to achieve efficient cytotoxicity. Here, we compared the
lytic phenotype of the SW480 cell line to its metastatic derivative, SW620, as an
in vitro paradigm to further characterize the nature of a HLA class I-restricted,
Ag-specific CTL response against neoplastic cell lines of primary and metastatic
origin. Although both colon carcinoma cell lines were lysed by these Ag-specific
CTL following IFN-gamma pretreatment, the mechanisms of lysis were distinct,
which reflected differential levels of sensitivity to the Fas pathway. Whereas
IFN-gamma pretreatment rendered SW480 cells sensitive to both Fas-dependent and
independent (perforin) pathways, SW620 cells displayed lytic susceptibility to
Fas-independent mechanisms only. Moreover, pretreatment of SW480 cells with the
anti-colon cancer agent, 5-fluorouracil (5-FU), led to enhanced Fas and ICAM-1
expression and triggered Ag-specific CTL-mediated lysis via Fas- and perforin
based pathways. In contrast, these phenotypic and functional responses were not
observed with SW620 cells. Overall, these data suggested that 1) IFN-gamma and 5
FU may enhance the lytic sensitivity of responsive colon carcinoma cells to
immune effector mechanisms, including Fas-induced lysis; 2) the malignant
phenotype may associate with resistance to Fas-mediated lysis in response to Ag
specific T cell attack; and 3) if Ag-specific CTL possess diverse lytic
capabilities, this may overcome, to some extent, the potential "escape" of Fas
resistant carcinoma cells.
PMID- 10779806
TI - Macrophage colony-stimulating factor antagonists inhibit replication of HIV-1 in
human macrophages.
AB - Macrophages infected with HIV-1 produce high levels of M-CSF and macrophage
inflammatory protein-1alpha (MIP-1alpha). M-CSF facilitates the growth and
differentiation of macrophages, while the chemotactic properties of MIP-1alpha
attract both T lymphocytes and macrophages to the site of HIV infection. Studies
described in this work indicate M-CSF may function in an autocrine/paracrine
manner to sustain HIV replication, and data suggest possible therapeutic
strategies for decreasing viral load following HIV infection. We show that
macrophage infection with measles virus or respiratory syncytial virus, in
contrast to HIV-1, results in production of MIP-1alpha, but not M-CSF. Thus, M
CSF appears to be specifically produced upon infection of macrophages with HIV-1.
Furthermore, addition of M-CSF antagonists to HIV-1-infected macrophages,
including anti-M-CSF monoclonal or polyclonal Abs or soluble M-CSF receptors,
dramatically inhibited HIV-1 replication and reduced production of MIP-1alpha.
Our results suggest that biologic antagonists for M-CSF may represent novel
strategies for inhibiting the spread of HIV-1 by 1) blocking virus replication in
macrophages, 2) reducing recruitment of HIV-susceptible T cells and macrophages
by MIP-1alpha, and 3) preventing the establishment and maintenance of infected
macrophages as a reservoir for HIV.
PMID- 10779807
TI - T cell activity after dendritic cell vaccination is dependent on both the type of
antigen and the mode of delivery.
AB - Previous work in both human and animal models has shown that CTL responses can be
generated against proteins derived from tumors using either peptide-pulsed
dendritic cells (DCs) or nucleic acids from the tumor transfected into autologous
DCs. Despite the efficacy of this approach for vaccine therapy, many questions
remain regarding whether the route of administration, the frequency of
administration, or the type of Ag is critical to generating T cell responses to
these Ags. We have investigated methods to enhance CTL responses to a peptide
derived from the human proto-oncogene HER-2/neu using mice containing a chimeric
HLA A2 and H2Kb allele. Changes in amino acids in the anchor positions of the
peptide enhanced the binding of the peptide to HLA-A2 in vitro, but did not
enhance the immunogenicity of the peptide in vivo. In contrast, when autologous
DCs presented peptides, significant CTL activity was induced with the altered,
but not the wild-type, peptide. We found that the route of administration
affected the anatomic site and the time to onset of CTL activity, but did not
impact on the magnitude of the response. To our surprise, we observed that weekly
administration of peptide-pulsed DCs led to diminishing CTL activity after 6 wk
of treatment. This was not found in animals injected with DCs every 3 wk for six
treatments or in animals initially given DCs weekly and then injected weekly with
peptide-pulsed C1R-A2 transfectants.
PMID- 10779809
TI - Fiche n 33 : BCR
PMID- 10779808
TI - Induction of AIDS virus-specific CTL activity in fresh, unstimulated peripheral
blood lymphocytes from rhesus macaques vaccinated with a DNA prime/modified
vaccinia virus Ankara boost regimen.
AB - The observed role of CTL in the containment of AIDS virus replication suggests
that an effective HIV vaccine will be required to generate strong CTL responses.
Because epitope-based vaccines offer several potential advantages for inducing
strong, multispecific CTL responses, we tested the ability of an epitope-based
DNA prime/modified vaccinia virus Ankara (MVA) boost vaccine to induce CTL
responses against a single SIVgag CTL epitope. As assessed using both 51Cr
release assays and tetramer staining of in vitro stimulated PBMC, DNA
vaccinations administered to the skin with the gene gun induced and progressively
increased p11C, C-->M (CTPYDINQM)-specific CD8+ T lymphocyte responses in six of
six Mamu-A*01+ rhesus macaques. Tetramer staining of fresh, unstimulated PBMC
from two of the DNA-vaccinated animals indicated that as much as 0.4% of all
CD3+/CD8alpha+ T lymphocytes were specific for the SIVgag CTL epitope.
Administration of MVA expressing the SIVgag CTL epitope further boosted these
responses, such that 0.8-20.0% of CD3+/CD8alpha+ T lymphocytes in fresh,
unstimulated PBMC were now Ag specific. Enzyme-linked immunospot assays confirmed
this high frequency of Ag-specific cells, and intracellular IFN-gamma staining
demonstrated that the majority of these cells produced IFN-gamma after peptide
stimulation. Moreover, direct ex vivo SIV-specific cytotoxic activity could be
detected in PBMC from five of the six DNA/MVA-vaccinated animals, indicating that
this epitope-based DNA prime/MVA boost regimen represents a potent method for
inducing high levels of functionally active, Ag-specific CD8+ T lymphocytes in
non-human primates.
PMID- 10779810
TI - [LGD1069: an antagonist to the X retinoid receptor].
PMID- 10779811
TI - [Screening for cancer: what's new?].
AB - Setting up of screening programmes for cancers has been the result of evaluation
studies but even more of the existence (or non existence) of national policies
for cancer control. We know for sure that mammographic screening can reduce
breast cancer mortality in women from age 50 onwards, smear screening has a
favourable impact on cervical cancer mortality and incidence, and faecal blood
testing in stools may reduce colon cancer mortality. Other questions, considered
for a long time as settled, are coming back, either because new data are
available, such as in screening for breast cancer before age 50, or because new
screening methods are being proposed, such as for lung cancer. Finally, the
recognition of populations at very high genetic risk makes necessary the search
for answers for example for familial breast and/or ovarian cancer. Last but not
least is the methodological challenge: how can we rapidly provide answers, which
implies the need for new approaches, in addition to randomized controlled trials?
PMID- 10779812
TI - [Abnormal cervical smear: what to do? National Agency for Accreditation and
Evaluation in Health].
PMID- 10779813
TI - [Phase II study of docetaxel in inoperable advanced non small cell lung cancer].
AB - The purpose is to determine the response to, and toxicity of docetaxel (Taxotere)
in patients with inoperable non small cell lung cancer (NSCLC), previously
untreated. Seventy patients with stage IIIB or IV NSCLC were treated by 100
mg/m2/ 3 weeks of docetaxel until tumor progression or severe toxicity.
Premedication with diosmine and prednisolone was given in all patients: 66/70
were eligible and 55/70 were assessable for antitumoral activity. Median age: 63
years, WHO performans status 0-1: 83%, stage IV: 96%. For eligible patients,
17/66 (26%) achieved an objective response: 1 complete response and 16 partial
response (IC 95% = 15-36). With a median follow-up of 23.4 months (range 14.9
28.7), for evaluable patients, the median response duration was 8 months, the
median time to progression 4 months, and the median survival time 10 months. The
median number of administered cycles is 5 (range 1-12). The estimate one year
survival rate was 47%. Seventy-six patients presented neutropenia (grade 3-4);
febrile neutropenia was observed in 7% of cycles. Non haematological toxicities
are: fluid retention related to docetaxel (2.9%), diarrhea (6%), nausea-vomiting
(4%), asthenia (3%), nail changes (6%). Docetaxel (Taxotere) administered at 100
mg/m2/3 weeks has relevant clinical activity in previously untreated NSCLC with a
acceptable toxicity.
PMID- 10779814
TI - [Oral granisetron solution as prophylaxis for chemotherapy-induced emesis in
children: double-blind study of 2 doses].
AB - This multicentric double-blind, dose-ranging study was to compare efficacy and
safety of two oral doses of granisetron solution in the prevention of
chemotherapy-induced emesis in children with malignant diseases : 294 children,
aged 1 to 16, treated with a moderately or highly emetogenic chemotherapy were
randomly assigned to receive oral granisetron either 20 microg/kg (n = 143) or 40
microg/kg (n = 151) before and 6 to 12 hours after the start of chemotherapy.
Fifty-one percent of patients treated with 20 microg/kg bd of oral granisetron
solution achieved a complete response (no vomiting, no worse than mild nausea, no
rescue therapy and no withdrawal during the specified period) and 59% achieved a
major response (no more than one episode of vomiting, no worse than mild nausea,
no rescue therapy and no withdrawal during the specified period). There was no
difference between the two oral doses of granisetron. Treatment was rated as good
or very good by investigators in 70% of cases. In conclusion, oral granisetron
suspension either at 20 microg/kg bd or at 40 microg/kg bd showed good efficacy
and safety in the prevention of chemotherapy-induced emesis in children with
malignant diseases. Oral granisetron solution can be used as prophylaxis of
emesis in children receiving moderately or highly emetogenic chemotherapy.
PMID- 10779815
TI - [Predictive value of preoperative abdominopelvic CT for optimal cytoreduction
surgery in ovarian carcinoma].
AB - Some patients underwent laparoscopy without optimal debulking surgery as initial
treatment for advanced ovarian carcinoma. The amount of residual tumor following
primary surgery was an important prognosis factor. Neoadjuvant chemotherapy is a
new therapeutic approach. Secondary, optimal surgery could be done in better
conditions. The purpose was to access the ability of preoperative abdominopelvic
CT to predict success of debulking surgery for ovarian carcinoma: less than 1 cm
of residual tumor size after initial surgery. We reviewed 39 patients (2 stages
Ic, 1 stage IIc, 22 stages III and 14 stages IV) operated on for ovarian
carcinoma between January 1992 and December 1997. Surgical criteria of inability
to perform optimal surgical cytoreduction were compared with abdominopelvic CT
done the month before. CT scans were prospectively assessed by radiologist A and
retrospectively (3 months to 6 years delay) rewiewed separately by radiologists A
and B without surgical data. Nineteen patients underwent optimal debulking
surgery: 13 no residual tumor and 6 with residual lesions under 1 cm. The
interreader (0.73) and intrareader (0.9) agreement, worked out by Kappa
coefficient, was juged good to very good. The sensitivity of CT was 91% with a
specificity of 95%. These results allowed us to determine wich CT criteria were
accurate and reproducible to be a helpfull for therapeutic choice and to avoid
laparotomy without optimal surgery.
PMID- 10779816
TI - Rectangular flaps technique for treatment of congenital hand syndactyly.
AB - The authors analysed a series of 22 patients undergoing surgical correction of
congenital hand syndactyly by the rectangular flap technique. Using our
evaluation method, we found that good functional and aesthetic results were
obtained in 77.3% of the patients, with a complication rate of 13.6%. We
concluded that the rectangular flap technique has a simple design, is easily
reproducible by in-training staff, has good results, and can be applied on the
majority of the syndactyly cases.
PMID- 10779817
TI - Influence of physical exercise and sodium intake on arterial pressure and cardiac
hypertrophy in rats.
AB - Evidence shows that cardiac hypertrophy (CH) is a risk factor for many
cardiovascular diseases. Several stimuli may cause CH-like manifestations and
promote volume or pressure overload. Exercise-induced cardiac hypertrophy is an
expected adaptation to regular exercise training. Salt intake has been shown to
be the most important determinant of blood pressure in different populations. The
purpose of the present work was to verify the influence of physical exercise and
sodium intake on the blood pressure and myocardium. The study was performed on 36
rats divided into six groups: Group I (diet without salt overload), Group II
(diet without salt overload and swimming), Group III (diet with 2.5% NaCl
solution and swimming), Group IV (diet with 5% NaCl solution and swimming), Group
V (diet with 2.5% NaCl solution without exercise), Group VI (diet with 5% NaCl
solution without exercise). The arterial pressure was significantly lower in
Group I when compared with Group IV. The ratio of cardiac mass/body mass was
increased in Groups III and IV. In conclusion, there was evidence that exercise
training and NaCl intake promotes arterial hypertension and cardiac hypertrophy.
PMID- 10779818
TI - Fatal pulmonary thromboembolism in gastrectomy intraoperative procedures by
gastric adenocarcinoma: case report.
AB - The case of a patient with gastric adenocarcinoma with indication for gastrectomy
is reported. The surgery took place without complications. A palliative, subtotal
gastrectomy was performed after para-aortic lymph nodes compromised by neoplasm
were found, which was confirmed by pathological exam of frozen sections carried
out during the intervention. At the end of the gastroenteroanastomosis procedure,
the patient began to show intense bradycardia: 38 beats per minute (bpm),
arterial hypotension, changes in the electrocardiogram's waveform (upper
unlevelling of segment ST), and cardiac arrest. Resuscitation maneuvers were
performed with temporary success. Subsequently, the patient had another
circulatory breakdown and again was recovered. Finally, the third cardiac arrest
proved to be irreversible, and the intra-operative death occurred. Necropsy
showed massive pulmonary embolism. The medical literature has recommended
heparinization of patients, in an attempt to avoid pulmonary thromboembolism
following major surgical interventions. However, in the present case,
heparinization would have been insufficient to prevent death. This case indicates
that it is necessary to develop preoperative propedeutics for diagnosing the
presence of venous thrombi with potential to migrate, causing pulmonary
thromboembolism (PTE). If such thrombi could be detected, preventative measures,
such as filter installation in the Cava vein could be undertaken.
PMID- 10779819
TI - Relationship between plasma creatinine concentration and glomerular filtration in
preterm newborn infants.
AB - Fluid management and dosage regimens of drugs in preterm infants should be based
on the glomerular filtration rate. The current methods to determine glomerular
filtration rate are invasive, time-consuming, and expensive. In contrast,
creatinine clearance can be easy obtained and quickly determined. The purpose of
this study was to compare plasma creatinine on the third and seventh day of life
in preterm newborn infants, to evaluate the influence of maternal creatinine, and
to demonstrate creatinine clearance can be used as a reliable indicator of
glomerular filtration rate. We developed a prospective study (1994) including 40
preterm newborns (gestational age < 37 weeks), average = 34 weeks; birth weight
(average) = 1840 g, in the first week of life. Inclusion criteria consisted of:
absence of renal and urinary tract anomalies; O2 saturation >/= 92%; adequate
urine output (>1ml/kg/hr); normal blood pressure; absence of infections and no
sympathomimetic amines in use. A blood sample was collected to determine plasma
creatinine (enzymatic method) on the third and seventh day of life and creatinine
clearance (CrCl) was obtained using the following equation: [formula: see text],
k = 0.33 in preterm infant All plasma creatinine determinations showed normal
values [third day: 0.78 mg/dl +/- 0.24 (mean +/- SD)and seventh day: 0.67 mg/dl
+/- 0.31 - (p>0.05)]. Also all creatinine clearance at third and seventh day of
life were normal [third day: 19.5 ml/min +/- 5.2 (mean +/- SD) and seventh day:
23.8 ml/min +/- 7.3 - (p>0,05)]. All preterm infants developed adequate renal
function for their respective gestational age. In summary, our results indicate
that, for clinical practice, the creatinine clearance, using newborn length, can
be used to estimate glomerular filtration rate in preterm newborn infants.
PMID- 10779820
TI - Radiographic aspects and angioarchitectural arrangements in corrosion casts of
the blood supply to the human sternocleidomastoid muscle by the
sternocleidomastoid branch of the occipital artery.
AB - The contribution of the sternocleidomastoid branch of the occipital artery
(superior arterial pedicle-SAP) to the irrigation of the sternocleidomastoid
muscle (SCM) was evaluated in fresh human cadavers by injecting radiological dye
and a resin for microvasculature corrosion casts. From its insertion in the
mastoid process of the temporal bone, the SCM was divided into superior, medium,
and inferior thirds. In most of the SCM, The SAP are formed by two longitudinal
parallel branches. In all specimens, the radiological dye injected into the SAP
reached or trespassed the middle part of the studied SCM. The SAP was poorly
distributed in the lowermost region of the inferior third of the SCM, suggesting
the contribution of other arteries or pedicles. The corrosion casts of the
microvasculature showed a profuse network of microscopic vessels in those levels
where the SAP was detected.
PMID- 10779821
TI - Double pylorus: case report and review of the literature.
AB - Double pylorus is an unusual condition in which a double communication between
the gastric antrum and the duodenal bulb occurs. It may be congenital, or it may
be acquired complication of peptic ulcer disease. We present a case of double
pylorus in a gentleman with epigastric pain and previous history of peptic ulcer
disease. The relationship between Helicobacter pylori and this disease was
assessed. A review of the literature, the role of associated diseases and the
role of H. pylori are discussed.
PMID- 10779822
TI - Low blood glucose levels and other complications during growth hormone
supplementation in sepsis.
AB - Blood glucose levels in the high normal range or even moderate hyperglycemia is
the expected profile in septic postoperative patients receiving high-calorie
enteral alimentation. The addition of growth hormone as an anabolic agent should
additionally reinforce this tendency. In a cancer patient undergoing partial
gastrectomy with lymphadenectomy and suffering from postoperative subphrenic
abscess and prolonged sepsis, tube feeding (38.3 kcal/kg/day) and growth hormone
(0.17 IU/kg/day) were simultaneously administered for 25 days. Blood glucose
levels were in the lower limits of the normal range before growth hormone
introduction, and continued with a similar tendency during most of the
therapeutic period. Two additional complications, namely heart arrest and
peripheral edema, were documented during the same period. It is concluded that
sepsis was the most likely mechanism for low glucose values, and that high
calorie enteral diet and growth hormone supplementation did not prevent that
result. It is uncertain whether heart arrest was due to the drug, but its
association with peripheral edema is well documented in clinical series.
PMID- 10779824
TI - Oxygen deficit is related to the exercise time to exhaustion at maximal aerobic
speed in middle distance runners.
AB - The purpose of this study was to show the relationship between oxygen deficit and
the time to exhaustion (tlim) at maximal aerobic speed (MAS). The minimum speed
that elicits VO(2max) was assumed to be the maximal aerobic speed (MAS). Fourteen
subelite male runners (mean (SD: age = 27 +/- 5 yrs: VO(2max) = 68.9 +/- 4.6 ml
kg (-1). min ( -1); MAS = 21.5 +/- 1 km h (-1) ) participated in the study. Each
subject performed an incremental test to determine and MAS. The subjects ran to
exhaustion at velocities corresponding to 100 and 120 % MAS. Oxygen deficit was
measured during the period exercise to exhaustion at 120% of MAS and was
calculated from the difference between O(2) demand and the accumulated O 2
uptake. The tlim values at 100% MAS were correlated with the values of tlim at
120% MAS (r = 0.52). The results reveal that the oxygen deficit was related to
the time to exhaustion at MAS and indicate that the greater the oxygen deficit,
the greater the time to exhaustion at MAS. It was also noted that the adjustment
of oxygen consumption is related to the oxygen deficit. In other words, the
subjects who have an important anaerobic capacity are the most efficient during
an exercise time to exhaustion at MAS. The time limit values can be expressed by
a linear regression making intervene MAS and anaerobic capacity. This conclusion
could be of great interest in the training of middle distance runners.
PMID- 10779823
TI - The influence of hypo- and hyperthyreosis on insulin receptors and metabolism.
AB - Changes in thyroid status affect metabolism not only directly, but influence it
also by alterations in insulin secretion and action. Despite several
investigations, these effects are, however, poorly characterised or even
controversial. The aim of the studies was to investigate the effect of
hyperthyreosis (HT) and hypothyreosis (HPT) on insulin binding by rat liver
membranes. Some metabolic parameters reflecting insulin and thyroid hormones
action were also determined. HT and HPT were developed by daily administration
for 3 weeks of thyroxine (T (4) ) and thiouracil (TU), respectively. Experimental
hyperthyreosis and hypothyreosis caused deep changes in metabolism. The greatest
alterations were observed in body and thyroid glands weight, blood
triiodothyronine (T (3) ), T (4), glucose, and insulin levels, liver glycogen
amount and number of insulin receptors. HT reflected in rats in slower rate of
growth and in smaller thyroid glands weight. In comparison to controls, T (4)
concentration in HT was almost doubled and it was reduced by about 30% in HPT.
Also, T(3), insulin and glucose levels in HT were heightened. Simultaneously,
binding of insulin to liver membranes was elevated in HT and reduced in HPT. In
HT the number of high affinity insulin receptors (HAIRs) and low affinity insulin
receptors (LAIRs) was increased, whereas in HPT the amount of HAIRs was
diminished. HT caused a drastic reduction of glycogen concentration in liver, but
no changes were observed for muscle glycogen. Considering lipid metabolism, only
free fatty acids (FFA) level in blood was changed (in HPT), but no differences
were observed in serum concentration of triglycerides and cholesterol. Several
metabolic changes observed in HT and HPT seem to be the dire ct consequence of
alterations of thyroid hormone concentrations. These disturbances, together with
the direct effect of HT or HPT on insulin secretion, binding and action lead, in
turn, to changes in the other metabolic parameters. As a result of these
disturbances the adaptive mechanisms appear. One of them is change in the number
of insulin membrane receptors taking place even against the well known "down
regulation" theory.
PMID- 10779825
TI - Luteinizing hormone releasing hormone increases proliferation of meningioma cells
in vitro.
AB - The fact that meningioma shows at least a 2:1 predilection for women over men is
considered to be due to endocrinological and paracrine regulation of the
development of this tumour. The presence of receptors for the luteinizing hormone
releasing hormone (LHRH) in gynaecological cancer permits the use of LHRH
agonistic or antagonistic analogues with a direct effect or by the gonado
pituitary axis suppression in the treatment of these tumours. Therefore, the
effect of LHRH on meningioma cells is tested in this study. Meningioma cells from
three female patients were cultured and LHRH (50 ng/ml) was added to the growth
medium daily, for fourteen days. At the end of this period the cells were counted
by means of a Coulter Counter. The stimulating effects of LHRH on the increase of
the amount of cells in the meningioma monolayer culture were 146% (p < 0.01),
134% (p < 0.05) and 141% (p < 0.05) of the control, respectively, for the three
patients.
PMID- 10779826
TI - Muscular force transmission: a unified, dual or multiple system? A review and
some explorative experimental results.
AB - Structures contributing to force transmission in muscle are reviewed combining
some historical and relatively recently published experimental data. Also,
effects of aponeurotomy and tenotomy are reviewed shortly as well as some new
experimental results regarding these interventions that reinforce the concept of
myofascial force transmission. The review is also illustrated by some new images
of single muscle fibres from Xenopus Laevis indicative of such transmission and
some data about locations of insertion of human gluteus maximus muscle. From this
review and the new material, emerges a line of thought indicating that mechanical
connections between muscle fibres and intramuscular connective tissue play an
important role in force transmission. New experimental observations are presented
for non-spanning muscle (i.c., rat biceps femoris muscle), regarding the great
variety of types of intramuscular connections that exist i n addition to myo
tendinous junctions at the perimuscular ends of muscle fibres. Such connections
are classified as (1) tapered end connections, (2) Myo-myonal junctions, (3) myo
epimysial junctions and (3) Myo-endomysial junctions. This line of thought is
followed up by consideration of a possible role of connections of intra- and
extramuscular connective tissue in force transmission out of the muscle.
Experimental results of an explorative nature, regarding the interactions of
extensor digitorum longus (EDL), tibialis anterior (TA) and hallucis longus (HAL)
muscles within a relatively intact dorsal flexor compartment of the rat hind leg,
indicate that: (1) length force properties of EDL are influenced by TA activity
in a length dependent fashion. Depending on TA length, force exerted by EDL, kept
at constant origin insertion distance, is variable and the effect is influenced
by EDL length itself as well; (2) Force is transmitted from muscle to
extramuscular connective tissue and vice versa. As a consequence force exerted at
proximal and distal tendons of a muscle are not always equal. The difference
being transmitted by extramuscular connective tissue and may appear at the
tendons of other muscles or may be transmitted via connective tissue directly to
bone. It is concluded that the system of force transmission from skeletal muscle
should be considered as a multiple system.
PMID- 10779828
TI - Intracerebroventricular infusion of hypertonic NaCl increases urinary CGMP in
healthy and cirrhotic rats.
AB - Implication of serum atrial natriuretic peptide (ANP) and endothelin-1 (ET1) in
the central nervous system (CNS)-induced natriuresis and hypertension
respectively, was investigated in healthy and cirrhotic rats. Both healthy and
nonascitic CCl(4)-induced cirrhotic rats under pentobarbital anesthesia received
either normotonic (140 mmol/L) or hypertonic (320 mmol/L) NaCl artificial
cerebrospinal fluid into the CNS lateral ventricle at a rate of 8.3 microl/min
for 120 min. A sham operated group, but not centrally infused, served as matched
control. Hypertonic NaCl solution significantly increased mean arterial pressure
(MAP) similarly in both healthy (n = 5) ((MAP: 16 mm Hg, 13%) and cirrhotic rats
(n = 6) ((MAP: 20 mm Hg, 15%) (ANOVA, p <.001) although the latter showed a
slower increment. Under hypertonic NaCl infusion, natriuresis was also
significantly increased in a similar manner in both healthy (U (Na) V: baseline:
0.38 +/- 0.22 micromol/min x 100 g; experiment: 2.36 +/- 0.90 micromol/min x 100
g; mean +/- SD) and cirrhotic rats (0.69 +/- 0.48 vs. 3.16 +/- 0.87; p <.001). By
contrast, central hypertonic NaCl solutions did not show a significant
modification of serum ANP in neither healthy (62 +/- 18 fmol/ml vs. 51 +/- 17
fmol/ml) nor cirrhotic rats (126 +/- 61 vs. 115 +/- 30). Likewise, ET-1 was not
significantly modified under central hypertonic NaCl infusion in neither healthy
(352 +/- 46 pg/ml vs. 344 +/- 39 pg/ml) nor cirrhotic rats (287 +/- 58 vs. 277 +/
61). Despite no modification in serum ANP, there was a significant increment in
urinary excretion of cGMP under central hypertonic NaCl infusions in bo th
healthy (6.8 +/- 4.1 pmol/min x 100 g vs. 13.0 +/- 6.5 pmol/min x 100 g; p <.05)
and cirrhotic rats (8.6 +/- 1.7 vs. 11.1 +/- 1.3; p <.05). Our data indicate the
preservation of the mechanisms of central natriuresis in a model of non-ascitic
CCl(4 )-induced cirrhosis in rats. An increment in urinary cGMP could potentially
be implicated in the natriuretic response obtained by intracerebroventricular
hypertonic NaCl stimulus in both healthy and cirrhotic rats. The lack of
modification of serum ANP and ET-1 does not appear to support a systemic
implication of these peptides in the natriuretic and hypertensive responses
respectively induced by this manoeuvre.
PMID- 10779827
TI - Routing, processing and export of rat pituitary prolactin: identification of a 36
kDa disulphide-bridged oligomeric preprolactin.
AB - To gain an insight in the routing, processing and export of rat prolactin, rat
pituitary cells were cultured in serum-free medium in the presence of
cycloheximide, carbonyl cyanide m-chlorophenylhydrazone, Brefeldin A and
monensin. The potential influence of these perturbants, whose well documented
effects are the altering of protein synthesis and transport, was studied on rat
prolactin molecular size isoforms appearing in cellular extracts and in culture
medium. The outcome of the culture experiments as recorded in vertical SDS-PAGE,
thiol gradient electrophoresis and sequential SDS-PAGE followed by prolactin
specific immunoblotting and densitometry, was as follows: (1) at the cellular
level we were able to characterize a novel 36 kDa protein as a disulphide-bridged
oligomeric precursor prolactin, which is presumably rapidly transformed in the
cis/medial Golgi; to designate monomeric rat prolactin as an early Golgi protein
and t o advance evidence that the main processing of the glycosylated rat
prolactin is a cis/medial Golgi event; (2) in release none of the perturbants
disturbed the relative distribution of monomeric and glycosylated rat prolactin,
the main molecular size isoforms currently secreted by untreated pituitary cells,
or induced the appearance of transformed molecular size isoforms; (3) the
secretion mode indicates that rat prolactin is released via the regulated pathway
in the presence of the perturbants used.
PMID- 10779829
TI - The effect of myo-inositol on ethanol-induced metabolic changes and insulin
concentration in the rat.
AB - Myo-inositol was found to possess several beneficial effects on the organism. The
effect of myo-inositol on ethanol-induced metabolic changes and insulin
concentration was investigated in growing rats. The increase in liver
triglycerides induced by ethanol drinking (10% ethanol solution as the only
drinking fluid for 10 days) was completely abolished by simultaneous treatment
with myo-inositol (0. 1 g/100 g b.w., every day given intragastrically). The
ethanol-evoked decrease in blood insulin and the increase in liver glycogen were
also partially prevented by myo-inositol. Myo-inositol did not cause any
undesirable metabolic changes in the rats. The results indicate that myo-inositol
may be useful in the treatment of some metabolic consequences of alcohol
drinking.
PMID- 10779830
TI - Mechanoreceptors in the glabrous skin of the human hand.
AB - Since the first systematic analysis concerning the functional properties of
mechanoreceptors in the glabrous skin of the human hand was made in 1970, the
amount of available data has grown tremendously. Whereas the first research in
the seventies was aimed at achieving a standard functional description of the
mechanoreceptors, research of the last two decades mostly has been directed
towards developing a more detailed and extended model of these receptors. For
example, recent investigations attempted to examine the role of populations of
mechanoreceptors with respect to the recognition of texture and shape of an
object touched by the human hand. Knowledge of the behaviour of the
mechanoreceptive units in the glabrous skin of the human hand is especially
relevant to people with a diminished or lost vision who depend on their tactile
system to perceive objects they cannot hear or smell. This essay tries to give a
brief overview of the development of this field from the first experiments on
human beings to the state of knowledge that has been gained today.
PMID- 10779831
TI - Humans with traumatic brain injuries show place-learning deficits in computer
generated virtual space.
AB - Spatial learning and memory has been linked to the hippocampus and temporal lobes
and though these areas are often damaged in traumatic brain injury (TBI), spatial
learning deficits after TBI have not received much attention. In the present
study, a virtual environment was used to challenge people with TBI to solve a
task comparable to the Morris water maze, which in turn has been shown to be
highly sensitive to hippocampal and frontal lobe dysfunction in laboratory
animals. A regular computer monitor was used to present 12 participants with TBI
and 12 age- and sex-matched comparison participants with a computer-generated,
three-dimensional "virtual arena maze," consisting of a large round arena within
a very large square room. Participants were required to learn the place of an
invisible target on the floor of the room based solely on distal cues on the
walls of the room. Eight of the 12 participants with moderate to severe TBI
showed substantial place-learning deficits in comparison to the uninjured
participants. Performance in the virtual environment correlated with self
reported frequency of wayfinding problems in everyday life and with scores on a
test of episodic memory, the Rivermead Behavioural Memory Task. These data
confirm that deficits in spatial learning and memory follow TBI, and suggest that
the virtual arena maze may provide a new method for objectively assessing them.
PMID- 10779832
TI - Differential demands on working memory for guiding a simple action sequence:
evidence from closed-head-injured subjects.
AB - In the present study, a working memory paradigm was used to assess coordinative
abilities required for the flexible control of a sequence of actions. Subjects
had to maintain and recall a list of digits that functioned as an ensemble of
activity cues used for guiding a sequence of forced-choice responses. In three
task conditions, the demand on the selection of the activity cues was varied
parametrically to manipulate the requirement of coordinating maintenance and
processing operations of working memory for guiding the response sequences. A
comparison between subjects suffering from severe closed head injury (CHI) and
matched controls in a blocked presentation of task conditions revealed that
patients, in contrast to controls, did not preplan the sequence by rearranging
the ensemble of activity cues prior to execution of the action sequence.
Patients' performance was more comparable to controls tested in a random
presentation in which preplanning was not possible. Our results further suggest
that patients are less efficient in selecting activity cues from working memory,
especially in more demanding situations when activity cues have to be completely
reordered for guiding a sequence of actions. These results point to an executive
dysfunction in CHI subjects that may contribute to the deficits known as
inflexible and rigid behavior.
PMID- 10779833
TI - Evaluation of a WMS-R malingering index in a non-litigating clinical sample.
AB - The purpose of this study was to examine the prevalence of a Wechsler Memory
Scale-Revised "malingering index" in a large sample of non-litigating individuals
from an inpatient substance abuse program. Past research has demonstrated that
experimental-malingerers often obtain substantially lower scores on the
Attention/Concentration Index than on the General Memory Index. In the present
study, only a small percentage of patients showed large General Memory -
Attention/Concentration difference scores. These results provide further support
for the validity of this difference score as a marker for non-optimal effort.
PMID- 10779834
TI - Role of perceptual and organizational factors in amnesics' recall of the Rey
Osterrieth complex figure: a comparison of three amnesic groups.
AB - To examine the contribution of visual-perceptual and visual-organizational
factors to visual memory in amnesia, Korsakoff, medial temporal, and anterior
communicating artery (ACoA) aneurysm amnesics' copy, organization, and recall
performance on the Rey-Osterrieth Complex Figure was assessed. Korsakoff patients
were matched to medial temporal patients in terms of severity of amnesia, while
the ACoA group, which was less severely amnesic, was matched to the Korsakoff
patients on performance on executive tasks. Results indicated that while both the
ACoA and Korsakoff groups had poorer copy accuracy and organization than
controls, only the Korsakoff patients' copy accuracy was worse than the other two
amnesic groups. While the Korsakoff patient's visuoperceptual deficits could
partially explain this group's poor performance at immediate recall, the
Korsakoff group's comparatively worse performance at delayed recall could not be
accounted for by poor copy accuracy, reduced visual organization, or even the
combined influence of these two factors.
PMID- 10779835
TI - Estimated premorbid intelligence mediates neurobehavioral change in individuals
infected with HIV across 12 months.
AB - This study tested whether estimated premorbid intelligence moderates worsening
neurobehavioral dysfunction in HIV infection. 155 homosexual men (54 controls, 49
HIV+ asymptomatic, 24 HIV+ symptomatic, 28 AIDS) with stable disease status were
tested on measures of executive function at baseline and 12-month follow-up.
Premorbid intelligence was estimated on the basis of a demographically-based
regression equation (Hamsher, 1984), and participants were classified as average
or above-average intelligence. Regardless of disease status, participants with
above-average IQ showed no declines on measures of executive function across
time. In contrast, among those with average IQ, symptomatic groups showed
declines, whereas the asymptomatic group did not. The findings support the
hypothesis that estimated premorbid intelligence mediates declines in
neuropsychological function in patients with stable HIV status. These findings
are consistent with theoretical models of cognitive reserve capacity.
PMID- 10779837
TI - Parkinsonian motor characteristics in unipolar major depression.
AB - Clinical observation points to similarities between psychomotor retardation in
major depression and bradykinesia in Parkinson's disease (PD). While common
elements of neuropathology have been proposed to account for this, experimental
investigations of this possible link have been few and inconclusive. The present
study attempts to determine whether patients with depression display the
characteristically Parkinsonian reliance on external cues; and if so, whether
this is common to both melancholic and non-melancholic patients. Twenty three
patients with unipolar major depression (11 melancholic and 12 non-melancholic)
and 24 age-matched healthy controls performed a serial choice reaction time task
known to be sensitive to Parkinsonian movement deficits. The melancholic patients
showed a Parkinsonian pattern of impairment on the task, exhibiting a particular
difficulty when initiating movements in the absence of external cues. This was
largely alleviated when a moderate amount of external cueing was provided. At a
high level of advance information, melancholic patients were again slow relative
to controls. A base-line measure of bradykinesia and a derived measure of
dependence upon external cues both correlated significantly with CORE (measure of
psychomotor disturbance) ratings. The non-melancholic patients did not show any
measurable motor impairment. This cue-dependent deficit may be due to an
underlying basal ganglia dysfunction similar to that involved in PD, i.e. a
failure of internal cueing. Difficulty with a high level of external cueing might
reflect bradyphrenia or a prefrontal motor deficit of ability to plan multiple
upcoming movements simultaneously. The results suggest that depression subtypes
involve differing patterns of fronto-striatal impairment.
PMID- 10779836
TI - Effects of preferred hand and sex on the perception of tactile simultaneity.
AB - The effects of handedness, sex and the influence of hand placement in
extrapersonal space on temporal information processing was investigated by
measuring thresholds for perceiving the simultaneity of pairs of tactile stimuli.
Simultaneity thresholds of preferred right handed and left handed university
students with left hemisphere speech representation were compared using unimanual
and bimanual stimulation at three hand placements (midline, lateral and crossed).
In unimanual conditions two fingers of one hand were stimulated (single
hemisphere), whereas in the bimanual conditions one finger of each hand was
stimulated (cross hemispheres). Bimanual minus unimanual thresholds provided an
estimate of interhemisphere transmission time (IHTT) regardless of hand
placement. The effects of hemispace varied with the type of stimulation. With
unimanual stimulation, overall thresholds were longer at the midline placement,
however, with bimanual stimulation, thresholds were longer when the hands were
spatially separated (crossed and/or uncrossed). Left handers' IHTTs were 8 ms
faster than those of right handers. IHTTs in males were faster than females with
hands placed in lateral (by 10.8 ms) or crossed (by 9.8 ms) but not midline
positions. It was concluded that the cerebral hemispheres are equally capable of
discriminating temporal intervals, but that the left hemisphere predominates when
there is uncertainty about location of stimulation.
PMID- 10779838
TI - Card sorting performance and ADHD symptomatology in children and adolescents with
tourette syndrome.
AB - Children and adolescents with Tourette Syndrome (TS) do not have a characteristic
neuropsychological profile. Performance on complex cognitive tasks, particularly
those associated with executive functioning (EF), has been variable and sometimes
contradictory. The high rate of comorbidity of TS with disorders, especially
Attention Deficit Hyperactivity Disorder (ADHD), may account for such
variability. A group of 57 individuals with TS, aged 8 - 16, was examined on a
component of executive functioning in relation to comorbid symptomatology of
ADHD. Each participant was evaluated using two EF measures, the Wisconsin Card
Sorting Test (WCST) and the California Card Sorting Test (CCST). Using factor
analytic procedures for purposes of data reduction, WCST and CCST measures loaded
on different factors. Individuals with TS who had a high rate of ADHD
symptomatology did not differ from those with a lower rate of ADHD symptomatology
on any measure of card sorting performance.
PMID- 10779839
TI - Preliminary study of working memory in children with stroke related to sickle
cell disease.
AB - The verbal working memory abilities of children with stroke related to sickle
cell disease (SCD) (n = 20) were compared to those of control children with SCD
who had no history of stroke (n = 11). Memory span for one-, two-, and three
syllable words was assessed. For children with anterior infarcts, overall span
was comparable to that of controls, but the typical effect of word length on span
was reduced. For children with diffuse infarcts, overall span was reduced in
comparison to that of controls, but the typical effect of word length on span was
observed. For children with posterior infarcts, overall span was comparable to
that of controls and the typical effect of word length on span was observed.
These results provide preliminary evidence that patterns of working memory
performance may vary across children with infarcts affecting different regions of
the brain.
PMID- 10779840
TI - Three words three shapes: A clinical test of memory.
AB - Three Words - Three Shapes was designed as an easy "bedside" test for elderly
patients that assesses verbal and nonverbal memory within the same modality. In
the present study, it was administered to patients with probable Alzheimer's
disease (PRAD), a control group of non-demented older subjects (NC) and a group
of patients with Korsakoff's amnesia (KA). Incidental recall and several other
measures of learning, retention and recognition differentiated control from PRAD
and KA subjects. PRAD and KA subjects' performance was similar, but there were
some material-specific interactions. This test is relatively easy and some of the
derived measures could prove useful in staging amnesia progression beyond the
earliest stages of PRAD when more difficult tests yield floor effects.
PMID- 10779841
TI - Development of two spanish versions of the verbal selective reminding test.
AB - The Selective Reminding procedure has become a widely used test for evaluating
verbal learning and memory. However, since this test was mainly devised for use
in English speaking individuals, disadvantages could appear when translations of
the test are applied to Spanish speaking patients. To overcome these
difficulties, two Spanish versions of the Verbal Selective Reminding Test were
devised and administered to 48 healthy individuals, 19-31 years in age, in two
separate sessions. We found that performances on the two forms were comparable,
except for one measure. All the variables on both forms yielded significant
positive correlations. We also examined test-retest reliability separately for
both possible orders, with Order 2 (Form 2 administered first) being more
reliable than Order 1 (Form 1 administered first).
PMID- 10779842
TI - Edouard Claparede and the auditory verbal learning test.
AB - This paper describes the role of the Swiss psychologist Edouard Claparede (1873
1940) in developing the Test de memoire des mots (Test of Memory for Words), a
test consisting of one free-recall trial of a 15-word list that is the antecedent
of the auditory verbal learning tests (AVLT) of Rey and others. The fact that
Claparede's test has survived in modified form for 80 years makes it one of the
oldest mental tests in continuous use. In addition to developing the AVLT,
Claparede's pioneering contributions to neuropsychology include forensic
assessment of cognitive deficits and research on implicit learning in amnesia.
PMID- 10779843
TI - Familial occurrence of artefactual ocular hypertension from thick corneas and of
primary open angle glaucoma in a French Canadian kindred.
AB - We describe the coexistence of artefactual ocular hypertension due to increased
central corneal thickness (CCT>585 microm), with primary open angle glaucoma
(POAG) in a French Canadian kindred. Seventeen members of the family were
examined and classified as to their glaucoma status. The mean CCT for our
glaucoma patients (580 microm; n=5) and that for normals (552 microm; n=6) were
within two standard deviations of the mean value provided in the literature (531
microm +/- SD=29 microm). The mean CCT of 611 microm for the suspect group (n=6)
was considerably higher than for the glaucoma and normal groups. All but one of
the suspects were classified as ocular hypertensives on the basis of high
intraocular pressures (IOPs). When the IOPs for these patients (mean 22.6 mmHg)
were corrected for their CCTs, all had pressures of <21 mmHg (mean 16.4 mmHg).
Ten of the seventeen family members had thick CCTs, and transmission of thick
corneas was seen in two generations. A number of individuals in this family had
optic nerve head drusen (9/17) and the mean CCT of these individuals (601 microm)
was higher than the mean CCT (560 microm) of the group without drusen (P=0.020 by
t test). Artefactual ocular hypertension and POAG can be present in different
members of the same family. The presence of a thick cornea appears to be an
inherited trait and may be associated with the presence of optic nerve drusen.
This association suggests a developmental relationship between thick corneas and
optic nerve head drusen which needs to be studied further.
PMID- 10779844
TI - Microfibril abnormalities of the lens capsule in patients with Marfan syndrome
and ectopia lentis.
AB - PURPOSE: To determine the distribution and structure of fibrillin microfibrils in
the three fibrillin-rich lens capsule zones of subjects with the Marfan syndrome.
METHODS: Capsules were dissected from nine lenses extracted intracapsularly from
Marfan syndrome patients. The capsules were divided and mounted flat on gelatin
coated glass slides. ABC immunoperoxidase staining with monoclonal anti-fibrillin
antibody was used to visualize and localize fibrillin in these specimens. The
staining patterns and microscopic structure of microfibrils were compared to
those of normal controls. RESULTS: There were no bundles of fibrillin fibers in
Zone I - a 0.75-mm wide peripheral ring of the anterior capsule that normally
contains radial bunches of fibrillin fibers; instead, fine disorganized fibrillin
positive fragments were dispersed in this region. The size and shape of the
fragments varied among patients. In contrast to normal lenses, there was only
light staining for fibrillin in Zone II - a 1-mm wide meshwork of normally
fibrillin-rich fibers that encircles the equator and serves as an insertion
platform for most zonular fibers. The radial periodic bands of Zone III - a 0.1
mm wide ring on the most peripheral part of the normal posterior capsule - were
identifiable in some samples, but stained only faintly for fibrillin. CONCLUSION:
Fibrillin microfibrils are disrupted and fragmented in the lens capsule of
patients with the Marfan syndrome. The qualitative, quantitative, and structural
abnormalities of fibrillin deposition in the lens capsule of these patients
support a causal relationship to lens abnormalities in this disease.
PMID- 10779845
TI - Corneal transplantation in a patient with mucopolysaccharidosis type VII (Sly
disease).
AB - PURPOSE: To illustrate a good visual outcome following penetrating keratoplasty
in a patient with Sly disease, a rare mucopolysaccharidosis (MPS) caused by a
deficiency of beta-glucuronidase. METHODS: A 15-year-old male with progressive
bilateral corneal opacification had a complete medical, genetic, and ophthalmic
evaluation followed by a penetrating keratoplasty. RESULTS: The cornea has
remained clear for two years following surgery. Histopathology of the corneal
button demonstrated vacuoles and granular inclusions consistent with this
lysosomal storage disease. CONCLUSION: While research is ongoing in the fields of
enzyme replacement and bone marrow transplantation, these treatments may not
alleviate or reverse the corneal clouding. This case illustrates that cornea
transplantation may be a valuable treatment option for visually rehabilitating
such patients.
PMID- 10779846
TI - Morning glory disk anomaly, choroidal coloboma, and congenital constrictive
malformations of the internal carotid arteries (moyamoya disease).
AB - PURPOSE: To report a patient with congenital constrictive malformations of the
internal carotid arteries and a morning glory disc anomaly (MGDA). METHODS:
Descriptive case report. RESULTS: A 14-year-old girl underwent serial
ophthalmologic examinations since the age of seven years because of blurred
vision and floaters. A right optic disk anomaly was present that was most
compatible with an MGDA accompanied by an inferior choroidal coloboma. Because of
the association of such disc malformations with moyamoya disease, the patient
underwent cerebral MRI and MRA that showed narrowing of both internal carotid
arteries, a finding consistent with early-stage moyamoya disease. CONCLUSION:
This case illustrates the importance of recognizing the association of MGDA with
moyamoya disease, a treatable condition that may have devastating neurological
consequences.
PMID- 10779847
TI - Identification of a novel mutation in the paired domain of PAX3 in an Iranian
family with waardenburg syndrome type I.
AB - Waardenburg syndrome Type I (WS1) is an autosomal dominant disorder that has
previously been associated with mutations in the PAX3 gene on the 2q35 region. In
this study, we used an Iranian WS1 family with seven affected individuals in
three generations. The phenotypic characteristics of the family include
sensorineural deafness, dystopia canthorum, hypopigmented skin patches of the
upper limbs, congenital white forelock, confluent white eyebrows, nonpigmented
iris, poliosis, and hypopigmentation of the retina. Herein, we report a
previously unidentified single-base substitution in exon II (C-->T at position
218) that results in a change of serine to leucine (S73L) in this family. This
change was not observed in 100 chromosomes of healthy unrelated individuals. This
mutation is within the PAX3 paired domain region, a structure that is highly
conserved and implicated in DNA binding. This is the first identification of a
PAX3 mutation for this phenotype in the Iranian population. This also provides
additional confirmation for the involvement of this gene in the etiology of WS1.
PMID- 10779848
TI - Summary of heritable ocular disorders and selected systemic conditions with eye
findings.
AB - A previously published table of ocular genetic disorders and inherited systemic
conditions with eye findings has been updated with a comprehensive review of
world literature. This tabulation of conditions is designed to provide a useful
desk reference for practitioners and medical scientists. The summary will serve
again as a benchmark of the significant advances that have occurred in the past
few years.
PMID- 10779849
TI - Kabuki syndrome - report of six cases and review of the literature with emphasis
on ocular features.
AB - Six cases of Kabuki syndrome (KS) with ocular anomalies are reported and the
variety of ocular features reported in the literature for this syndrome is
described. Routine ocular examinations are recommended for every patient with KS
because of the high proportion of ocular anomalies found in these patients, the
presence of which can hamper development if not adequately addressed.
PMID- 10779850
TI - Dietary sodium chloride (salt), other dietary components and blood pressure:
paradigm expansion, not paradigm shift.
PMID- 10779851
TI - A non-invasive cardiovascular index for the quantification of arterial load.
AB - OBJECTIVE: Our aim is to quantify steady and pulsatile components of arterial
load in a concise and sensitive way by means of a new non-invasive cardiovascular
index (NICI). METHODS AND RESULTS: NICI is based on non-invasively measured
pressure (sphygmomanometer), stroke volume index and cardiac index (Doppler
echocardiography and ECG) and yields a numerical value (in mm Hg). It expresses
the difference between the actual arterial load and reference loading conditions
as determined in a control group (29 M/35 F, age 34 +/- 13 yr.) of healthy
subjects, with blood pressure 116/61 mm Hg (systolic/diastolic), stroke volume
index (SVI) 34 +/- 18 ml.m-2 and cardiac index (CI) 2.1 +/- 0.5 l.min-1.m-2. NICI
was calculated in the control group and in 23 borderline hypertensive subjects
(10 M/13 F, age 65 +/- 12 yr.) with blood pressure 156/79 mm Hg, SVI 36 +/- 10
ml.m-2 and CI 2.4 +/- 0.6 l.min-1.m-2. NICI was higher in borderline
hypertensives (33 +/- 51 vs. 0 +/- 34 mm Hg; P < 0.001) and was strongly
correlated with total peripheral resistance index (r = 0.89; P < 0.001) and with
the ratio of SVI and pulse pressure (r = -0.89; P < 0.001), expressing the
combined effect of both known determinants of cardiac load. NICI was also
correlated with effective arterial elastance index (r = 0.89; P < 0.001).
CONCLUSIONS: NICI quantifies, within a logical biomechanical framework, the
arterial load as seen by the ejecting ventricle. It combines steady and pulsatile
components of arterial load and has a single control value of zero mm Hg.
PMID- 10779852
TI - Long-term time-related predictivity of coronary events as a function of a single
measurement of serum cholesterol and systolic blood pressure.
AB - OBJECTIVE: To study the time-related association of a single measurement of serum
cholesterol and systolic blood pressure with the occurrence of a first coronary
event in a population sample of middle-aged men. METHODS AND RESULTS: A single
measurement of serum total cholesterol and systolic blood pressure (along with
age, cigarette consumption, physical activity at work and body mass index as
possible confounders) was made in 1,605 coronary disease-free men aged 40-59
belonging to the Italian rural cohorts of the Seven Countries Study. During 25
years of follow-up 353 men developed a first event, that is a coronary death
(sudden or not), and definite or possible myocardial infarction. Twenty-five
partitioned proportional hazards models were solved, one for each independent
year of follow-up, to predict the risk of incident events. Single-year hazard
functions, separately for serum cholesterol and systolic blood pressure, were
cumulated and smoothed. The resulting curves showed a regularly increasing risk
for coronary events. They fit straight lines, with large correlation coefficients
for both serum total cholesterol (r = 0.99) and systolic blood pressure (r =
0.99). These slopes were similar to the coefficients estimated by a single
proportional hazards model solved for all events during 25 years. CONCLUSION: A
single measurement of serum total cholesterol and systolic blood pressure in
middle aged-men maintains a regular and monotonic relationship with occurrence of
a first coronary event during 25 years of follow-up.
PMID- 10779853
TI - Postpericardiotomy syndrome during intensive immunosuppression after cardiac
transplantation.
AB - A 15-year-old man with end-stage heart failure due to dilated cardiomyopathy,
underwent heart transplantation. In the second postoperative week, while being
treated with monoclonal antibodies (OKT3), cyclosporine and azathioprine, he
developed a postpericardiotomy syndrome and cardiac tamponade, which necessitated
emergency pericardiocentesis. Corticosteroids, administered according to the
immunosuppression protocol, resulted in the prompt subsidence of the syndrome.
This is the first report of a large pericardial effusion and cardiac tamponade
due to a postpericardiotomy syndrome in an adult cardiac recipient.
PMID- 10779854
TI - Early presentation of a giant true left ventricular aneurysm.
PMID- 10779855
TI - Left circumflex coronary artery arising as a terminal extension of the right
coronary artery.
PMID- 10779856
TI - COMT inhibition in Parkinson's disease: rationale and clinical relevance.
PMID- 10779857
TI - The potential and limitations of transcranial Doppler in clinical practice.
AB - The aim of this review is to bring the clinical relevance of transcranial Doppler
(TCD) to light with all of its possibilities and limitations. Indeed, TCD, a non
invasive ultrasound technique, allows instantaneous evaluation of the cerebral
blood flow, adding physiological information to the anatomical images. Although
TCD is frequently used in some places, in other regions TCD remains relatively
unknown. However, TCD can help the neurologist not only in the management of
cerebrovascular disease, but also in a wide variety of central nervous system
disorders. TCD monitoring with multichannel and multigate probes can assess
vascular reactivity by following various parameters, such as CO2 or arterial
blood pressure. Despite the need for more work, emboli detection seems to offer
great potential in the future diagnosis, treatment, and prevention of stroke.
PMID- 10779858
TI - Magnetic resonance imaging in psychiatry.
AB - Recent technical advances in MR imaging have led to several new applications in
psychiatric imaging. There is a renewed interest in the further elucidation of
the etiopathogenesis of some psychiatric disorders and clinical-radiological
correlations are increasingly reported. Volume measurements are frequently used
and in the near future, functional MR imaging carries high expectations. A brief
survey is given of the recent applications of these new techniques in
schizophrenia, affective disorders, dementia, anorexia nervosa, and other less
common disorders.
PMID- 10779859
TI - [Generation of isolated words in normal subjects].
AB - This study aims at analyzing the performance according to age, sex, and
educational level in 112 French normal subjects on word generation tests, i.e.,
time-limited production of a noun or a verb semantically linked to a target
"noun" or "verb". The nature of hits (exclusively production of nouns) has
moreover been analyzed according to different features of the targets: noun vs
verb, names of natural objects vs handmade objects, transitive vs intransitive
verbs. Results show 1) a significant effect of age and educational level on
performance, 2) a degree of difficulty, the verb/verb production test being
significantly more difficult than the three other tests, 3) a convergency effect
according to the natural vs handmade dichotomy, as subjects tend to produce,
without specific instruction, an item belonging to the same category as that of
the stimulus, and 4) object nouns tend to be produced in response to transitive
verbs whereas subject nouns are not predominantly produced in response to
intransitive verbs.
PMID- 10779860
TI - Adult-onset nemaline myopathy and monoclonal gammopathy: a case report.
AB - A 47-year-old female developed proximal limb weakness after hysterectomy for
uterine fibromatosis. Muscle strength slowly improved, but relapse occurred at
age 52. She presented with progressive gait difficulty, proximal limb weakness,
and painful calves. Family history was not contributory. Cranial nerves, deep
tendon reflexes, and sensation were normal. Serum creatine kinase was normal. An
IgG kappa monoclonal protein was found. Nerve conduction studies were normal, but
EMG showed brief small polyphasic motor unit action potentials with early
recruitment in proximal muscles. Muscle biopsy showed abundant rods, atrophic
muscle fibres, and type 1 fibre predominance. The sarcolemma was immunoreactive
for IgG kappa. Plasmapheresis was unsuccessful, but methylprednisolone and
azathioprine led to moderate improvement of muscle strength, associated with
reduced monoclonal protein levels. This is the third case report, describing the
association of monoclonal gammopathy and late-onset nemaline myopathy. Presence
of a monoclonal protein at the sarcolemma and responsiveness to immunosuppressive
treatment are suggestive of a dys-immune origin.
PMID- 10779861
TI - Serum levels of alpha-carotene, beta-carotene, and retinol in patients with
multiple sclerosis.
PMID- 10779862
TI - Hypnagogic hallucinations and REM-sleep: an alternative pathophysiology.
PMID- 10779863
TI - Tuberculous cerebellar abscess.
PMID- 10779864
TI - Stroke and pseudoxanthoma elasticum.
PMID- 10779865
TI - Characterization of a major envelope protein from the rumen anaerobe Selenomonas
ruminantium OB268.
AB - Cell envelopes from the Gram-negative staining but phylogenetically Gram-positive
rumen anaerobe Selenomonas ruminantium OB268 contained a major 42 kDa heat
modifiable protein. A similarly sized protein was present in the envelopes of
Selenomonas ruminantium D1 and Selenomonas infelix. Sodium dodecyl sulfate
polyacrylamide gel electrophoresis of Triton X-100 extracted cell envelopes from
S. ruminantium OB268 showed that they consisted primarily of the 42 kDa protein.
Polyclonal antisera produced against these envelopes cross-reacted only with the
42 kDa major envelope proteins in both S. ruminantium D1 and S. infelix,
indicating a conservation of antigenic structure among each of the major envelope
proteins. The N-terminus of the 42 kDa S. ruminantium OB268 envelope protein
shared significant homology with the S-layer (surface) protein from Thermus
thermophilus, as well as additional envelope proteins containing the cell surface
binding region known as a surface layer-like homologous (SLH) domain. Thin
section analysis of Triton X-100 extracted envelopes demonstrated the presence of
an outer bilayer over-laying the cell wall, and a regularly ordered array was
visible following freeze-fracture etching through this bilayer. These findings
suggest that the regularly ordered array may be composed of the 42 kDa major
envelope protein. The 42 kDa protein has similarities with regularly ordered
outer membrane proteins (rOMP) reported in certain Gram-negative and ancient
eubacteria.
PMID- 10779866
TI - Factors affecting the freeze-fracture morphology of in vivo polyhydroxyalkanoate
granules.
AB - Interesting morphologies were observed when Comamonas acidovorans containing
polyhydroxyalkanoates (PHA) of various compositions was freeze-fractured at
temperatures far below the glass transition temperatures of PHA. In vivo granules
of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) comparatively showed the most
ductility, and could be stretched extensively. Contrary to the uniform needle
type deformation shown by the poly(3-hydroxybutyrate) homopolymer when fractured
at -110 degrees C, copolymers containing 3-hydroxyvalerate units showed various
deformation structures. Similar observations were made when in vivo granules of
poly(3-hydroxybutyrate-co-4-hydroxybutyrate) were freeze-fractured, although the
ductility of the latter was much reduced. In addition, it was found that
fracturing at -160 degrees C resulted in decreased ductility of the PHA granules
with the concomitant increase in the number of mushroom-type deformation
structures. Our results suggest that PHA granules with higher resistance to
freeze-fracture deformation show less ductility, and therefore produce the
mushroom-type morphology. This is the first report on the freeze-fracture
morphology of PHA copolymers containing short-chain-length monomers.
PMID- 10779867
TI - Ca2+ fluxes in developing Trichoderma viride mycelium.
AB - The properties of both Ca2+ influx and efflux in the mycelium during the life
cycle of Trichoderma viride were studied by means of 45Ca2+ and by X-ray
fluorescence spectroscopy measurements. The properties of the 45Ca2+ influx and
effluxes indicate that they are mediated by different transport systems. The Ca2+
influx could be mediated by an electrogenic Ca2+/nH+ antiport, or by an Ca2+
uniport system. Both Ca2+ influx and efflux were stimulated by the uncouplers
(and the treatment leading to the suppression of energy metabolism) and by
azalomycin F, an antifungal agent. Salicylate stimulated the Ca2+ efflux, but
inhibited the Ca2+ influx. In the isolated preparation of crude
vacuolar/mitochondrial fraction, salicylate induced the Ca2+ release, as did
A23187. Azalomycin F moderately released Ca2+ from the microsomal fraction. On
the other hand, uncouplers did not release Ca2+ from the isolated organelles, but
inhibited to a different extent the ATP-dependent and -independent Ca2+ influx.
The results could be explained in terms of the capacitative Ca2+ influx
mechanism. The rate of 45Ca2+ influx, or of the 40Ca2+ content, was maximal after
about 30 h of submerged cultivation, and then decreased. The results show that
loading of internal Ca2+ stores occurs in the early stages of the development of
mycelium only, and the Ca2+ influx mechanism is developmentally down-regulated,
being almost nonexistent during its later stages. In older mycelium, growth seems
to be autonomous of the extracellular Ca2+ until the onset of conidiation.
PMID- 10779868
TI - Detection of the Na(+)-translocating NADH-quinone reductase in marine bacteria
using a PCR technique.
AB - To examine the distribution of the Na(+)-translocating NADH-quinone reductase
(Na(+)-NQR) among marine bacteria, we developed a simple screening method for the
detection of this enzyme. By reference to the homologous sequences of the Na(+)
NQR operons from Vibrio alginolyticus and Haemophilus influenzae, a pair of
primers was designed for amplification of a part of the sixth ORF (nqr6) of the
Na(+)-NQR operon. When PCR was performed using genomic DNA from 13 marine
bacteria, a 0.9-kbp fragment corresponding to nqr6 was amplified in 10 strains.
Although there were three PCR-negative strains phylogenetically, based on the
sequence of the 16S rRNA, these were placed far from the PCR-positive strains. No
product was observed in the case of nonmarine bacteria. The nucleotide and
predicted amino acid sequences of nqr6 were highly conserved among the PCR
positive marine bacteria. A phylogenetic analysis of marine bacteria, based on
nqr6 sequencing, was performed.
PMID- 10779870
TI - Characterization of high density monolayers of the biofilm bacterium Caulobacter
crescentus: evaluating prospects for developing immobilized cell bioreactors.
AB - Caulobacters are biofilm-forming members of the natural flora of soil and aquatic
environments, which exhibit several characteristics that make them attractive for
development of high surface area microbial bioreactors or biosensors. Although
caulobacters are well characterized genetically, little is known about their
biofilm-forming characteristics as a monoculture, or their tolerance of
bioreactor-like conditions. Here we investigated the ability of caulobacters to
spontaneously form high-density monolayers on artificial surfaces under a variety
of environmental conditions, using phase contrast image analysis to assess
biofilm density, and epifluorescence with the vital stain DiBAC to assess
viability. With adequate nutrition, extremely dense monolayers formed within 24
48 h, and maintained near 100% viability in experiments ranging up to 22 days.
When areas were abraded to remove cells, repopulation occurred rapidly with
characteristics similar to the population of a clean surface. When established
monolayers were starved for nutrients, a significant fraction of the cells
detached from the surface, and cells remaining on the surface no longer tested as
viable. Within 4-6 h of nutrient restoration, however, cells in the monolayer
again appeared normal and tested as 100% viable. This is the first demonstration
that Caulobacter crescentus is stable and amenable to high density monolayer
growth and resists starvation, though some cells may express a programmed
response to detach from the surface under severe nutrient limitation.
PMID- 10779869
TI - Shuttle vectors for genetic manipulations in Ustilago maydis.
AB - Shuttle vectors with new or improved features were constructed to enable facile
genetic manipulations in the plant pathogen Ustilago maydis. Sets of plasmids
selectable in media containing geneticin, carboxin, nourseothricin, or
hygromycin, able to replicate autonomously, to transform U. maydis by
integration, and to express foreign genes under control of the homologous
glyceraldehyde-3-phosphate dehydrogenase promoter, were built upon a common pUC19
vector backbone. This permits a large number of choices for a cloning site,
blue/white screening for recombinant plasmids, rapid transfer of a cloned DNA
fragment between plasmids, and choice of several dominant drug-resistance markers
for selection in U. maydis.
PMID- 10779871
TI - Development of a xylitol biosensor composed of xylitol dehydrogenase and
diaphorase.
AB - In preparation for the development of a xylitol biosensor, the xylitol
dehydrogenase of Candida tropicalis IFO 0618 was partially purified and
characterized. The optimal pH and temperature of the xylitol dehydrogenase were
pH 8.0 and 50 degrees C, respectively. Of the various alcohols tested, xylitol
was the most rapidly oxidized, with sorbitol and ribitol being reduced at 65% and
58% of the xylitol rate. The enzyme was completely inactive on arabitol, xylose,
glucose, glycerol, and ethanol. The enzyme's xylitol oxidation favored the use of
NAD+ (7.9 U/mg) over NADP+ (0.2 U/mg) as electron acceptor, while the reverse
reaction, D-xylulose reduction, favored NADPH (7.7 U/mg) over NADH (0.2 U/mg) as
electron donor. The K(m) values for xylitol and NAD+ were 49.8 mM and 38.2
microM, respectively. For the generation of the xylitol biosensor, the above
xylitol dehydrogenase and a diaphorase were immobilized on bromocyan-activated
sephallose. The gel was then attached on a dissolved oxygen electrode. In the
presence of vitamin K3, NAD+ and phosphate buffer, the biosensor recorded a
linear response to xylitol concentration up to 3 mM. The reaction was stable
after 15 min. When the biosensor was applied to a flow injection system, optimal
operation pH and temperature were 8.0 and 30 degrees C, respectively. The
strengths and limitations of the xylitol biosensor are its high affinity for
NAD+, slow reaction time, narrow linear range of detection, and moderate affinity
for xylitol.
PMID- 10779872
TI - Comparative evaluation of conjugate vaccines in the Haemophilus influenzae
infection model.
AB - We used a murine model of Haemophilus influenzae type b (Hib) infection to
analyze the immunologic response to two commercially available PRP conjugate
vaccines (HbOC, PRP-T). The mortality rate in mice infected with a large dose of
the bacteria after vaccination with HbOC or PRP-T at two and three doses was
significantly lower than in non-vaccinated mice and mice vaccinated by one dose.
Furthermore, for infections caused by a small bacterial dose, the mortality rate
in mice vaccinated with one, two, or three doses was significantly lower than in
non-vaccinated mice. The induction level of anti-PRP antibodies, especially IgG,
in serum of mice vaccinated by two or three doses was higher than in those
vaccinated with a single dose. Our results indicate that the dose of vaccine
influences its efficacy in protecting against Hib infection. Our results also
showed a lack of difference between two different PRP conjugate vaccines.
PMID- 10779874
TI - Characterization of chitinases excreted by Bacillus cereus CH.
AB - Bacillus cereus CH was shown to excrete chitinases into the culture supernatant
when cultivated in a medium containing 0.2% colloidal chitin, whereas the removal
of colloidal chitin resulted in a low activity. After concentration of the
culture supernatant by precipitation with ammonium sulfate, the induced
chitinases were purified by sequential chromatography. Four different chitinases,
A, B1, B2, and B3 with molecular masses of 35, 47, 58, and 64 kDa, respectively,
were separated. All chitinases showed similarities in their kinetic parameters
when observed with colloidal chitin, including an optimal pH of 5.0-7.5, and an
optimal temperature between 50-60 degrees C. Chitinase A hydrolyzed glycol chitin
and p-nitrophenyl-di-N-acetyl-beta-chitobioside at similar rates to that of
colloidal chitin, whereas group B chitinases hydrolyzed both substrates in much
lower rates. From analyses of the reaction products, it is most likely that
chitinase A and all group B chitinases hydrolyze the substrates tested in an endo
fashion. However, group B chitinases were distinct from chitinase A in possessing
high transglycosylation activity. From amino terminal sequencing, chitinases B1,
B2, and B3 were shown to have almost identical sequences, which differed from
that of chitinase A. The similarities in the reaction modes and amino terminal
sequences among chitinases B1, B2, and B3 suggest that these chitinases may be
derived from a presumptive precursor protein through C-terminal processing.
PMID- 10779873
TI - Introduction of the Serratia marcescens chiA gene into an endophytic Pseudomonas
fluorescens for the biocontrol of phytopathogenic fungi.
AB - An endophytic strain of Pseudomonas fluorescens was isolated from micropropagated
apple plantlets and introduced into beans (Phaseolus vulgaris) via their root
tips. It was shown to be present as an endophyte in the roots at a level of 1.2 x
10(5) CFU/g fresh weight. The gene coding for the major chitinase of Serratia
marcescens, chiA, was cloned under the control of the tac promoter into the broad
host-range plasmid pKT240 and the integration vector pJFF350. Pseudomonas
fluorescens carrying tacchiA either on the plasmid or integrated into the
chromosome is an effective biocontrol agent of the phytopathogenic fungus
Rhizoctonia solani on bean seedlings under plant growth chamber conditions.
PMID- 10779875
TI - Differential transport properties of D-leucine and L-leucine in the archaeon,
Halobacterium salinarum.
AB - The transport of D-leucine was compared with that of L-leucine in Halobacterium
salinarum. When a high-outside/low-inside Na+ gradient was imposed, D-leucine as
well as L-leucine accumulated in envelope vesicles, supporting the hypothesis
that D-leucine is transported via a symport system along with Na+. Kinetic
analyses, including inhibition experiments, indicated that both enantiomers are
transported via a common carrier. However, a Hill plot indicated a single binding
site for Na+ during L-leucine transport, but dual binding sites for Na+ during D
leucine transport. Furthermore, D-leucine transport was dependent on electrical
membrane potential, suggesting that a transporter bound with D-leucine is
positively charged. L-leucine transport was slightly, if at all, dependent on
membrane potential, suggesting that a transporter bound with L-leucine is
electrically neutral. These results indicate that the leucine carrier in
Halobacterium salinarum translocates two moles of Na+ per mole of D-leucine, and
one mole of Na+ per mole of L-leucine.
PMID- 10779876
TI - Inactivation of maltose permease and maltase in sporulating Saccharomyces
cerevisiae.
AB - Maltose transport and maltase activities were inactivated during sporulation of a
MAL constitutive yeast strain harboring different MAL loci. Both activities were
reduced to almost zero after 5 h of incubation in sporulation medium. The
inactivation of maltase and maltose permease seems to be related to optimal
sporulation conditions such as a suitable supply of oxygen and cell concentration
in the sporulating cultures, and occurs in the fully derepressed conditions of
incubation in the sporulation acetate medium. The inactivation of maltase and
maltose permease under sporulation conditions in MAL constitutive strains
suggests an alternative mechanism for the regulation of the MAL gene expression
during the sporulation process.
PMID- 10779877
TI - Effects of non-ionic surfactants on the uptake and hydrolysis of
fluoresceindiacetate by alkane-oxidizing bacteria.
AB - Biological effects of non-ionic surfactants on alkane-oxidizing bacteria were
studied by assessing their influence on the uptake of prefluorochrome
fluoresceindiacetate (FDA) and its intracellular hydrolysis to fluorescein. Both
decreasing and increasing rates of hydrolysis as a consequence of the presence of
surfactants were observed. The surfactants influenced the uptake of FDA, but not
its intracellular hydrolysis. The effects of the surfactants on the uptake rate
depended strongly on the structure and physico-chemical properties of the
surfactants. There was no qualitative or significant quantitative difference in
surfactant susceptibility between induced (alkane grown) and non-induced bacteria
(acetate grown), even though the induced cells possess greater cell surface
hydrophobicity.
PMID- 10779878
TI - Localization of phytase in Selenomonas ruminantium and Mitsuokella multiacidus by
transmission electron microscopy.
AB - The localization of phytase (myo-inositol-hexaphosphate phosphohydrolase) in the
ruminal bacteria, Selenomonas ruminantium JY35 and Mitsuokella multiacidus
46/5(2), was determined with transmission electron microscopy. Phosphate produced
from the enzymatic dephosphorylation of the calcium salt of phytic acid is
precipitated as calcium phosphate. The calcium is then replaced with lead to
produce electron-dense lead phosphate. This deposition of lead phosphate
localized phytase in S. ruminantium JY35 and M. multiacidus 46/5(2) to the outer
membrane, and confirmed intracellular expression of the enzyme in Escherichia
coli pSrP.2, the recombinant clone which possesses the gene (phyA) encoding
phytase (phyA) in S. ruminantium.
PMID- 10779879
TI - Schizophrenia: building and fixing scientific models.
PMID- 10779880
TI - Are animal studies of antipsychotics appropriately dosed? Lessons from the
bedside to the bench.
AB - Animal models are crucial for understanding the mechanism of action of
antipsychotics. However, the dose of an antipsychotic in animal studies is often
arbitrarily chosen, with haloperidol 1 mg/kg being a rather common standard.
Recent clinical positron emission tomography (PET) studies in patients show all
antipsychotics to block dopamine D2 receptors, and most are effective at doses
that lead to 60% to 80% D2 occupancy. When occupancy exceeds 80%, the incidence
of side effects rises sharply. To use this "bedside" information to inform the
"bench," we measured D2 occupancy in rats using a method similar in principle to
the [11C]-raclopride PET method in humans. We found that: 1) as in humans,
haloperidol is effective in animal models of antipsychotic action when D2
occupancy > 70% and leads to effects in models of extrapyramidal side effects
when D2 occupancy is > 80%; 2) very low doses, 0.06 mg/kg/sc, cause acute D2
occupancy of 75%; 3) and even doses that acutely saturate D2 receptors give
little D2 occupancy after 24 hours due to the very short half-life of haloperidol
in rats (2.5 hours versus 24 hours in humans). We conclude that most previous
animal studies of antipsychotics have used doses giving rise to inappropriately
high acute D2 occupancy and inappropriately low D2 occupancy between doses. We
exemplify how this dosing confounder could lead to inappropriate conclusions.
Data from the bedside translated to the bench--using D2 occupancy as a mediating
variable--will lead to more valid animal models.
PMID- 10779881
TI - Dual cytoarchitectonic trends: an evolutionary model of frontal lobe functioning
and its application to psychopathology.
AB - OBJECTIVE: To introduce and discuss an evolutionary model of frontal lobe
functioning (the dual cytoarchitectonic trends theory [DTT]) and its application
to understanding the neurobiology of schizophrenia and anxiety disorders. METHOD:
An introduction to the DTT with respect to neural architecture, connectivity, and
function is presented. In addition, neurobiologic, neuropathologic, clinical, and
cognitive research supporting the application of this model to schizophrenia and
anxiety disorders is reviewed. RESULTS: Traditional neuropsychologic models of
acquired brain damage have been limited in their ability to explain frontal lobe
dysfunction and its consequences in relation to psychopathology. The DTT offers
an appropriately general neural-systems framework that may be better able to
account for the diversity of symptoms, widespread neuropathology, and
developmental abnormalities that are associated with most forms of
psychopathology. CONCLUSIONS: Research investigating the neurobiology of
psychopathology would benefit from adopting models of brain dysfunction that are
consistent with neurodevelopmental pathology and evolution. Such efforts would
likely lead to a greater understanding of neurobiologic mechanisms and,
ultimately, better treatment strategies.
PMID- 10779882
TI - On the pharmacotherapy of obsessive-compulsive disorder: is a consensus possible?
AB - OBJECTIVE: To examine the efficacy and tolerability of clomipramine compared with
the selective serotonin reuptake inhibitors (SSRIs) in the treatment of obsessive
compulsive disorder (OCD), bearing in mind the recent Expert Consensus Guidelines
recommendation to use clomipramine after 2 to 3 failed SSRI trials. METHOD: The
literature on the pharmacotherapy of OCD was critically examined. RESULTS: The
available research evidence is not conclusive but suggests that clomipramine
possesses greater anti-obsessional efficacy than do the SSRIs. In addition, when
clomipramine is presented to patients in a positive way, and properly used in
small initial doses with gradual increases, it seems to be tolerated as well as
the SSRIs. CONCLUSION: Recently expressed opinions that clomipramine should be
used to treat OCD after 2 to 3 failed SSRI trials are not supported by research
evidence. Both clomipramine and the SSRIs may be used as first-line treatments
for OCD.
PMID- 10779883
TI - Perceptions of parental bonding and symptom severity in adults with depression:
mediation by personality dimensions.
AB - OBJECTIVE: An association between anomalous parental bonding experiences (lack of
parental care, overprotection, or both) and depression during adulthood has been
observed in several studies. The objective of the present study was to evaluate
several different personality dimensions as possible mediators of the
relationship between perceptions of parental bonding and depressive symptoms in
adulthood. METHODS: Outpatients with depression (n = 138) completed the Parental
Bonding Instrument (PBI), the Beck Depression Inventory (BDI), and several
measures of proposed personality vulnerabilities to depression. The conceptual
and methodological criteria of Baron and Kenny (1986) were used to assess
possible mediating effects of personality variables. RESULTS: In men,
overprotection by their fathers was significantly associated with depression;
neuroticism, socially prescribed perfectionism, and concern over mistakes acted
as mediators of this relationship. In women, lack of care by their mothers was
significantly associated with depression; self-criticism, socially prescribed
perfectionism, and concern over mistakes mediated this relationship. CONCLUSIONS:
The present study provides evidence that personality factors may mediate the
observed relationship between parental rearing style and depression. These
potential causal mechanisms warrant longitudinal evaluation.
PMID- 10779884
TI - Predictors of service use and social conditions in patients with psychotic
disorders.
AB - OBJECTIVE: To determine independent predictors of outcome on 3 separate
dimensions--namely, relapse and service use, employment, and living conditions-
in patients with psychotic disorders. METHOD: One hundred and thirty-four
patients, most with a diagnosis of schizophrenia or schizoaffective disorder
(94%), were treated and followed up in a comprehensive treatment program with
inpatient and community treatment components. Complete data on several predictor
and outcome variables were available on 93 patients. Relationships between
predictor variables and each dimension of outcome were analyzed using Spearman
correlation and multiple regression analysis. RESULTS: Results showed that the
use of inpatient resources (days in hospital) during the follow-up period was
predicted by days in hospital prior to entry into the program, as was employment
status. Although substance abuse was related to employment status, it did not
have any predictive value. Better living conditions were predicted by being
female and having a later age of onset. CONCLUSIONS: Use of inpatient resources
and social dimensions of outcome in schizophrenia may be predicted by different
patient- or illness-related variables. These relationships are likely to be
modified by the nature and content of treatment received.
PMID- 10779885
TI - Comorbidity in juvenile obsessive-compulsive disorder: a report from India.
AB - OBJECTIVE: Using minimal exclusion criteria, to assess systematically the
psychiatric comorbidity in children and adolescents with obsessive-compulsive
disorder (OCD) and compare the findings with those of previous studies. METHOD:
Fifty-four children and adolescents who satisfied DSM-III-R criteria for OCD were
assessed using a structured interview schedule, the Children's version of the
Yale-Brown Obsessive Compulsive Scale (CY-BOCS), and the questionnaire for tic
disorders. All 54 subjects were recruited from the Child and Adolescent
Psychiatry (CAP) services of the National Institute of Mental Health and Neuro
Sciences (NIMHANS), Bangalore, South India. Diagnoses were determined
consensually after a review of all the available data. RESULTS: Comorbidity was
found in 69% of the sample: 22% were diagnosed with disruptive disorders; 20% met
criteria for mood disorders; 19% had anxiety disorders; and 17% had tic
disorders. Only 1 subject had bipolar disorder, and none had psychosis. The rates
for individual diagnoses--in particular, the rates for disruptive disorders,
bipolar disorder, and psychosis--were considerably lower than those reported in
previous studies. CONCLUSIONS: Patterns of comorbidity in this study differed
from those previously reported. Novel patterns of comorbidity with disruptive
disorders, bipolar disorder, and psychosis reported in a few recent studies were
not replicated in this study. These differences are probably due to different
ascertainment methods. Comorbidity needs to be assessed in large epidemiological
samples before definite associations can be made between certain comorbid
disorders and juvenile OCD.
PMID- 10779886
TI - Measuring depression in Canada's elderly Chinese population: use of a community
screening instrument.
AB - OBJECTIVE: To assess the reliability and validity of a 15-item Chinese Geriatric
Depression Scale (GDS) to measure depression in Canada's elderly Chinese
population. METHOD: A random sample of 96 elderly Chinese in a Canadian city was
surveyed by telephone. The measure of depression used was the 15-item Chinese
version of the GDS. In addition, the physical and mental health of the
respondents was assessed by a Chinese version of the SF-12, questions on self
perceived general health, and questions on self-reported illnesses and health
concerns. RESULTS: The prevalence rate of depression in the elderly Chinese who
participated in this study is approximately 20%, which is much lower than that of
elderly Chinese in the United States (US). Cronbach's alpha and split-half
reliability coefficients were 0.88 and 0.89 respectively. GDS scores are
significantly correlated with the mental health component (r = -0.74) of the SF
12, indicating a strong convergent validity. GDS scores are also correlated with
the physical health component of the SF-12 (r = -0.41), self-perceived general
health (r = -0.26), and illnesses (r = 0.52), demonstrating concurrent validity.
CONCLUSIONS: The 15-item Chinese GDS has good internal consistency and both
convergent and concurrent validity. It can help to identify depression among the
elderly Chinese, allowing early identification and prevention of this problem.
Further research is required to support its use in clinical settings.
PMID- 10779887
TI - The use of selective serotonin reuptake inhibitors during pregnancy and
lactation: current knowledge.
AB - This article reviews the effects of the selective serotonin reuptake inhibitor
(SSRI) class of antidepressants in pregnant and lactating women for the treatment
of depression and anxiety disorders. An examination of the literature was
conducted using Medline (1966 to present). Despite methodological concerns and
the scarcity of data on this important subject, the majority of recent
investigations demonstrate safety of the fetus exposed to SSRIs during pregnancy.
All of the SSRIs reported in the studies are excreted into breast milk, and low
levels have been found in infant serum. The implications of this for practice
include identifying the effects of treatment versus nontreatment on the mother
infant dyad. Further research must examine long-term neurobehavioural
teratogenicity in exposed infants.
PMID- 10779889
TI - Antidepressants increase gene expression of a neuroprotective enzyme.
PMID- 10779888
TI - Estrogen receptor activation and tardive dyskinesia.
AB - OBJECTIVE: To undertake a selective review of the epidemiology, etiology, and
treatment of tardive dyskinesia (TD), with emphasis on the potential influence of
estrogen in its expression. METHOD: Both Medline and Psycinfo databases were used
to search for articles with the following key words: tardive dyskinesia, humans,
animals, dopamine, estrogen, estrogen replacement therapy, antioxidants and
oxidative stress. RESULTS: The studies reviewed here suggest that estrogen
modulates dopamine-mediated behaviours and that it protects against oxidative
stress-induced cell damage caused by long-term exposure to antipsychotic
medication. CONCLUSIONS: Estrogen's multimodal role in the central nervous system
may prove useful for the amelioration or prevention of TD. All the evidence
suggests that a placebo-controlled, randomized trial with safer forms of estrogen
should be conducted in postmenopausal women with TD.
PMID- 10779890
TI - Bilateral pulmonary embolism in a patient on clozapine therapy.
PMID- 10779891
TI - The Internet, suicide, and human mental functions.
PMID- 10779892
TI - Continuing medical education.
PMID- 10779893
TI - Re: The effects of hypnosis on dissociative identity disorder.
PMID- 10779894
TI - Quetiapine associated with acute mental status changes.
PMID- 10779895
TI - Capgras syndrome during the wake and dream state.
PMID- 10779896
TI - Trichotillomania: a challenge to research and practice.
AB - This review explores several aspects of trichotillomania relevant to clinical
theory and practice. It is concluded that research outlining the phenomenology
and patterns of comorbidity of trichotillomania have been advanced significantly
in recent years. However, no current diagnostic category appropriately classifies
trichotillomania. Research with nonclinical populations suggests that
trichotillomania is more common than previously believed and that additional
epidemiological research is warranted. Continued elaboration of existing
etiological models incorporating varying theoretical perspectives is also
encouraged. Assessment of trichotillomania could also be improved by the
continued development of reliable and valid standardized measures. This article
reviews both pharmacological and psychological treatments for trichotillomania,
with an emphasis on habit-reversal training. Though some interventions appear
effective in the short-term, reported relapse rates are high and future research
on treatment for trichotillomania should focus on improving long-term outcomes.
It is clear that despite a recent flux of research centering on trichotillomania,
significant challenges for understanding and treating this psychological disorder
still exist for researchers and clinicians. Based on this review of the
literature, and on our clinical experience with trichotillomania, we propose
directions for future research with this underserved psychiatric group.
PMID- 10779897
TI - Psychosocial adjustment of adult children of alcoholics: a review of the recent
empirical literature.
AB - This review examines controlled studies of the psychosocial adjustment of adult
children of alcoholics (ACOAs) published since 1988. ACOAs appear at increased
risk for a variety of negative outcomes, including substance abuse, antisocial or
under-controlled behaviors, depressive symptoms, anxiety disorders, low self
esteem, difficulties in family relationships, and generalized distress and
maladjustment. However, none of these outcomes are uniformly observed in ACOAs
and none are specific to ACOAs. Comorbid parental pathology, childhood abuse,
family dysfunction, and other childhood stressors may contribute to or produce
similar outcomes. There is little empirical support for "ACOA syndromes"
described in the clinical literature.
PMID- 10779898
TI - The impact of comorbid mood and personality disorders in the cognitive-behavioral
treatment of panic disorder.
AB - The present review examined the effect of comorbid major depressive disorder and
personality disorder on the outcome of cognitive-behavioral interventions for
panic disorder. Panic disorder patients often present with these comorbid
conditions, but for the most part, treatment studies have paid little attention
to them. Most studies on the effects of comorbidity on treatment outcome address
pharmacological treatment. However, there is a growing literature on the effect
of additional disorders on the outcome of cognitive-behavioral interventions for
panic disorder. Findings from the studies of comorbidity with depression are
equivocal, possibly reflecting inconsistencies in measurement methodology across
studies. However, personality psychopathology was found to exert a detrimental
effect on the outcome of cognitive-behavioral treatment for panic disorder.
Further research is necessary to elucidate the impact of these concurrent
conditions on cognitive-behavioral treatment for panic disorder. It is suggested
that studies utilizing cognitive-behavioral treatment routinely examine the
influence of comorbid conditions on treatment outcome.
PMID- 10779899
TI - Attention-deficit hyperactivity disorder and posttraumatic stress disorder:
differential diagnosis in childhood sexual abuse.
AB - Attention-deficit hyperactivity disorders (ADHD) and posttraumatic stress
disorder (PTSD) are the most commonly diagnosed disorders in sexually abused
children (SAC). There is a high degree of symptom overlap and comorbidity between
these disorders, and differential diagnosis can be confusing. Current diagnostic
criteria do not include PTSD as a differential diagnosis for ADHD, nor do
existing assessment guidelines address these diagnostic similarities. This may
have serious implications for SAC. This literature review describes the
psychological impact of child sexual abuse and possible consequences for
misdiagnosing ADHD in SAC. A comparison of criteria from the Diagnostic and
Statistical Manual of Mental Disorders, fourth edition (American Psychiatric
Association, 1994) criteria for ADHD and PTSD is presented, and commonalities are
discussed. On the basis of this comparison, recommendations are made for
improving clinical decision-making and for facilitating differential diagnosis.
Routine inquiry about traumatic experiences in children presenting with ADHD
symptoms is suggested to increase accuracy in differential diagnosis.
PMID- 10779900
TI - Social skills deficits associated with depression.
AB - This article reviews the empirical evidence of impaired social skills associated
with depression. Conceptualizations of social skills are examined followed by
evidence from self-report, observer-rating, and behavioral assessments of
depressed people's social skills. Evidence of social skills deficits in children
with depression and in people with bipolar disorder is also examined. The
effectiveness of social skills training as a treatment of depression is
evaluated. Three different theoretical relationships between disrupted social
skills and depression are described and evaluated, including poor social skills
as a cause of depression, depression as a cause of poor social skills, and poor
social skills as a vulnerability factor in the development of depression.
Currently, there is some evidence to support each of these conceptualizations, as
the relationship between poor social skills and depression can take a variety of
forms.
PMID- 10779901
TI - Treatment of maladaptive behavior in acquired brain injury: remedial approaches
in postacute settings.
AB - This article describes remedial behavior therapy approaches for the treatment of
maladaptive behavioral sequelae to an acquired brain injury (ABI). Remedial
approaches are sophisticated and nonintrusive treatment strategies that involve
teaching the individual skills or capacities to manage difficult life
circumstances. Functional equivalence is one major category of remedial
intervention and involves the determination of the behavioral function of the
problem behavior and the teaching of an adaptive alternative response or skill
cluster that provides the individual with efficient access to that function.
Errorless remediation is a second category and entails teaching the individual to
tolerate situations associated with problem behavior through hierarchical
exposure to increasingly difficult conditions and reinforcement for successful
management of those conditions.
PMID- 10779903
TI - [Transformation of Mycoplasma hominis by plasmid pAM120 using electroporation].
AB - Mycoplasma hominis was transformed by electroporation with plasmid pAM120
containing the transposon Tn916 that carried the tetM gene responsible for the
resistance to tetracycline. The frequency of transformation was 10(-7)-10(-8)
colony-forming units (CFU) per 10 micrograms of plasmid DNA. The PCR analysis of
transformed DNA confirmed the transposon integration into the mycoplasma genome.
PMID- 10779902
TI - Update on home visiting for pregnant women and parents of young children.
PMID- 10779904
TI - [Genomic organization of the murine neuro-d4 gene].
AB - As the first step toward obtaining the null mutation or knock out of the neuro-d4
gene, we isolated phages containing fragments of the gene from a mouse genomic
library. The nucleotide sequence of a region of the gene more than 10 kb in size
was determined.
PMID- 10779905
TI - [Effect of a null mutation in the priA gene on radioresistance of Escherichia
coli].
AB - According to Kogoma's model of DNA recombination by replication, the PriA protein
is involved in the RecBCD pathway of double-strand break (DSB) repair, which is
associated with extensive DNA degradation, at the stage of primosome assembly in
D-loops (intermediates of strand exchange at the ends of DSB) for the subsequent
switch to DSB-induced DNA resynthesis. Comparable data on possible involvement of
the PriA protein in the repair of gamma-ray-induced lethal lesions in cells of
the wild-type strain of Escherichia coli (strain AB1157) and in two radiation
resistant mutants Gamr445 and Gamr444 were obtained. In all the three strains
examined, the null priA2::kan mutation in the structural priA gene was shown to
markedly enhance the radiation sensitivity, causing a two- to threefold increase
in the slopes of linear dose-survival curves. In the AB1157 strain, the
inactivation of PriA is manifested most clearly in the range of low doses (up to
0.15 kGy) when the priA2::kan mutation had only a slight effect on the radiation
resistance of Gamr mutants. It can be assumed that, in these mutants with a
decreased level of postradiation DNA degradation, the PriA-dependent RecBCD
pathway of DSB repair associated with extensive DNA resynthesis is not essential
for the repair of lethal lesions at low doses. However, this pathway becomes
crucial at higher doses (> 0.5 kGy) even for radiation-resistant strains,
especially for the most resistant Gamr444 mutant.
PMID- 10779906
TI - [Cloning and expression of the lux-operon of Photorhabdus luminescens, strain
Zm1: nucleotide sequence of luxAB genes and basic properties of luciferase].
AB - A chromosomal fragment of bacteria Photorhabdus luminescence Zm1, which contains
the lux operon, was cloned into the vector pUC18. The hybrid clone containing
plasmid pXen7 with the EcoRI fragment approximately 7-kb was shown to manifest a
high level of bioluminescence. By subcloning and restriction analysis of the
EcoRI fragment, the location of luxCDABE genes relative to restriction sites was
determined. The nucleotide sequence of the DNA fragment containing the luxA and
luxB genes encoding alpha- and beta-subunits of luciferase was determined. A
comparison with the nucleotide sequences of luxAB genes in Hm and Hw strains of
Ph. luminescence revealed 94.5 and 89.7% homology, respectively. The
enterobacterial repetitive intergenic sequence (ERIC) of 126 bp typical for Hw
strains was identified in the spacer between the luxD and luxA genes. The lux
operon of Zm1 is assumed to emerge through recombination between Hm and Hw
strains. Luciferase of Ph. luminescence was shown to possess a high thermal
stability: its activity decreased by a factor of 10 at 44 degrees C for 30 min,
whereas luciferases of marine bacteria Vibrio fischeri and Vibrio harveyi were
inactivated by one order of magnitude at 44 degrees C for 1 and 6 min,
respectively. The lux genes of Ph. luminescence are suggested for use in gene
engineering and biotechnology.
PMID- 10779907
TI - [Age-related changes in crossing over in Drosophila resemble the picture of
interchromosomal effect of chromosome rearrangement on crossing over].
AB - Crossing over in the left arm of chromosome 2 (2L) was studied in successive
broods of Drosophila melanogaster females carrying intact chromosomes (+/+),
inversion Muller-5 in the X chromosome (M-5/+), and insertion of the Y-chromosome
material into region 34A (Is(2L)/+). The regions net-dp, dp-b, b-pr and pr-cn
were examined in 14 two-day-old broods of females +/+ and M-5/+ and in 10 broods
of females Is(2L)/+. In all lines, the highest level of crossing over was in the
first three broods (eggs laid during the first 6 days of oviposition) and the
lowest level in the broods 7-8 (eggs laid at days 14-16). A high rate of crossing
over in the first broods of females +/+ and M-5/+ was due to an increment of
exchanges in the proximal euchromatin regions (b-pr and pr-cn) and to an increase
in the number of tetrads with double exchanges. These changes are similar to a
pattern of the interchromosomal effect on crossing over (IEC) in structurally
normal chromosomes. In Is(2L)/+ females, a high level of crossing over was due to
extensive exchanges in the interstitial regions net-dp and dp and an increase in
the number of tetrads with single exchanges. These changes resembled the IEC in
rearranged chromosomes (in this case, in chromosomes bearing an insertion). Thus,
the age changes of crossing over are similar to the consequences of the presence
or absence of IEC. Age changes in crossing over in a chromosome depended both on
the local rearrangements in this chromosome (the local effect on crossing over,
LEC) and on rearrangements in nonhomologous chromosomes (IEC). In the first
broods, both LEC and IEC decreased with an increase in the level of crossing
over. In subsequent broods, the reduced level of crossing over was accompanied by
an increase in both LEC and IEC. This suggests that the mechanisms responsible
for the age changes in crossing over and IEC may have common steps. The contact
model of crossing over may explain the similarity between the age changes in
crossing-over and IEC. It is suggested that both phenomena result from delayed
determination of crossing over in a meiotic cell. This may occur due to the
retarded formation of the local contacts in one of the homologous chromosome
pairs or because a higher number of local contacts is required to trigger
crossing over in a meiotic cell (of early age).
PMID- 10779908
TI - [Divergence of karyofunds in sibling species of the plumosus group (Diptera:
Chironomidae)].
AB - Cytogenetic differentiation of eight sibling species of the plumosus group was
examined. The karyofunds of these sibling species were shown to diverge
incompletely. In each species karyofund, the banding sequences homologous to
those of the remaining species of this group were revealed. The number of banding
sequences that displayed interspecific homology varied from 3 to 13 per species
karyofund. In a species karyotype, the homologous sequences were localized to
chromosome arms 1-6. Both similar and contrasting frequencies of homologous
banding sequences were observed in karyofunds of different sibling species. The
average cytogenetic distance between sibling species of the plumosus group was
2.618 +/- 0.400. The presence of species-specific banding sequences, the absence
of homologous banding sequences in some chromosome arms of the karyotype, and
different frequencies of the homologous banding sequences determined the
cytogenetic divergence of the sibling species.
PMID- 10779909
TI - [Phases of the effect of the homeotic Walker mutation in the development of
Drosophila melanogaster].
AB - In this work, critical ontogenetic stages for wing traits affected by temperature
sensitive mutation Walker (Wk) were determined. The interaction between the Wk
gene and some genes responsible for the cell-cycle control was studied. At
various ontogenetic stages, the mutants were exposed to 17 degrees C for 12 h,
and, at the beginning of oviposition, the fly age was registered. Nine types of
wing abnormalities were classified. The temperature treatment during three
developmental stages (12-24, 48-60, and 96-108 h) resulted in a decrease in
normal wing number and a substantial increase in wing abnormalities. Different
morphological types of imaginal disks were revealed: nondifferentiated disks,
those lacking the notum region, and those with duplications of wing-forming
regions. The allele-specific interaction between Wk and allele v27 of the Klp61F
gene was also revealed. We suggest that gene Wk is a high-ranking gene in the
system of genetic control of ontogeny, because the Wk mutation is manifested in
numerous phenotypic variants both in the control and in the experiment and a
complete set of these variants was observed at each developmental stage upon
temperature treatment. The pleiotropic effect of the Wk gene on the formation of
some Drosophila organs, including eyes and halters which are beyond the scope of
this report, is in agreement with this suggestion.
PMID- 10779911
TI - [Karyotype and divergence of stream Dolly Varden from the Southern Sakhalin].
AB - The karyotype of stream Dolly Varden inhabiting a tributary of the Belaya River
(the basin of Naiba River, southern Sakhalin) was determined (2n = 82 and NF = 98
+ 2). According to the main characteristics (chromosome number and arm number,
the presence of a pair of marker submeta-subtelocentric chromosomes with
nucleolus organizer regions (NORs), one pair of large acrocentric chromosomes,
and one pair of subtelocentric chromosomes), this karyotype is identical to the
karyotype of anadromous southern Dolly Varden from Salvelinus malma
krasheninnikovi of Primorye and Japan. However, in most stream Dolly Varden
individuals, additional active nucleolus organizer regions (NORs) located in
telomeric and paracentric regions of two to three pairs of acrocentric
chromosomes were revealed. It is suggested that the stream and anadromous
southern forms of Dolly Varden are evolutionarily related NORs that are silent in
the anadromous souther form are active in the stream form. Possible causes of
these differences in NOR activity are discussed.
PMID- 10779910
TI - [RAPD-markers linked to the locus for resistance to the race 4 pathogen for black
rot, Xanthomonas campestris pv. campestris (Pamm.) Dow., in Brassica rapa L].
AB - Association between the RAPD markers and the resistance to race 4 of the black
rot causative agent was studied in Brassica rapa L. Experiments were carried out
using doubled haploid lines, obtained via crosses between the race 4-susceptible
fodder turnip and resistant pak-choi, and the F2 progeny of the crosses between
the doubled haploid lines with contrasting resistance. The WE(22)980 RAPD marker
inherited from the pak-choi and associated with the clubroot susceptibility was
also linked to the locus responsible for the resistance to race 4 of Xanthomonas
campestris pv. campestris. The two other RAPD markers were linked to
susceptibility to black rot. Simultaneous association of the same DNA markers
with the resistance/susceptibility to two different obligate pathogens favored
the hypothesis on cluster organization of the resistance genes in plants. The
markers described can be used in plant breeding and in further investigation of
the genetic bases of resistance in plants.
PMID- 10779913
TI - [Distribution of a deletion-insertion polymorphism in intergenic region V of
mitochondrial DNA among the aboriginal population of Tuva].
AB - Mitochondrial DNA region V deletion-insertion polymorphism was examined in three
Tuvinian populations inhabiting western, northeastern, and southeastern parts of
the republic. The 9-bp deletion was characterized by nonrandom distribution
across the Tuva territory: its frequency in the western population (13.37%) was
statistically significantly higher than that in the northeastern (4.62%), and
southeastern populations, as well as in Mongols, who are territorially and
ethnically close to Tuvinians. The insertion mutation in the region V was
detected with a frequency of about 3% in two out of the three populations tested.
PMID- 10779912
TI - [Polymorphism T174M of the angiotensinogen gene in Siberian populations].
AB - The level of T174M polymorphism of the angiotensinogen gene (AGT) was studied for
the first time in Siberian populations. The frequency of allele M was found to be
7% in Russians, 6% in Tuvinians, and 4% in Buryats. In the Mongoloid population
of Siberia (Tuvinians and Buryats), the genotypic frequencies deviated from Hardy
Weinberg equilibrium (P < 0.05). The studied polymorphism of the AGT gene
determined in Siberian populations was compared with that of other ethnic groups
in the world population, and genetic distinctions were estimated. Only the Buryat
population was found to differ significantly from the French, English, and
Chinese in the frequency of allele M. No association between the T174M
polymorphism of the AGT gene and pathological pregnancy (gestosis) was revealed
in Buryat women.
PMID- 10779914
TI - [Microsatellite haplotypes of the Y-chromosome demonstrate the absence of
subdivisions and presence of several components in the Tuvinian male gene pool].
AB - The haplotype analysis of seven Y-chromosome microsatellites in three regional
populations of Tuvinians revealed high intrapopulation variation in the male gene
pool of the modern population of the Tuva Republic. In total, 49 haplotypes were
found in 111 individuals; only four haplotypes occurred at a frequency higher
than 5%. High genetic diversity (H = 0.935) suggested a high power of
discrimination for the Y-chromosome haplotypes. The analysis of molecular
variance (AMOVA) and other data did not reveal subdivision of the Tuvinian
population with respect to Y-chromosome haplotypes. Most haplotypes found in
Tuvinians formed two lines. Line A included approximately 64% of the haplotypes
found, line B, approximately 24%. A putative ancestral haplotype of line B was
similar to a haplotype most common in modern Caucasoids (Md = 3), whereas a
putative ancestral haplotype of line A proved to be distant from the ancestral
haplotype of line A and haplotypes common for Caucasoids and Mongoloids.
Estimates of the age of the Y-chromosome lines showed that the male gene pool of
modern Tuvinians originated in the late Paleolithic or Neolithic period. With two
methods, the age of line A was estimated at 3500 or 18,000 years and the age of
line B was approximately at 5500 or 15,000 years. Considering the less
conservative estimates to be more reliable, line B was assumed to originate from
the ancient Caucasoid population of the Tuva region. The more widespread and
evolutionarily younger line A was associated with the peopling region by ancient
Mongoloid tribes of the Turkic language group in the Hun-Sarmatian period.
PMID- 10779915
TI - [Effect of inactivating the p33ING1 tumor suppressor on the function of cell
cycle "checkpoints" and genome stability].
AB - Novel candidate tumor suppressor p33ING1 is known to regulate activity of the p53
protein. The effect of p33ING1 inactivation on the functioning of the cell cycle
"checkpoints" and the frequency of chromosomal aberrations was examined.
Transduction of the p33-GSEas genetic suppressor element, known to reduce the p53
activity, into p53-positive rat and human cells resulted in: (1) partial
abolishment of ethylmetansulphonate- or colcemid-induced arrest of the G1-to-S
transition in the G0-synchronized cultures; (2) abolishment of the block in the S
phase by the DNA synthesis inhibitor, N-phosphonacetil-L-aspartate (PALA); (3) an
increase of the number of spontaneous chromosomal breaks and sister-chromatid
exchanges; (4) increased frequency of colchicine-induced polyploidy. Similar
effects were observed upon transduction of the p53-GSE22 genetic suppressor
element, known to reduce p53 transcriptional activity. Presumably, the effect of
p33ING1 inactivation on the cell cycle checkpoints and genetic stability is
associated with a decrease in p53 activity.
PMID- 10779916
TI - [A defense mechanism of human cells in the radioadaptive response and
antimutagenic activity of interferon has common paths].
AB - The radioadaptive response was assessed by the chromosome aberration test in
lymphocytes of humans with hereditary diseases of connective tissue, which were
earlier characterized as repair-deficient: Marfan syndrome (SM), Elers-Danlos
syndrome (E-D), and homocystinurea (HCU). The radioadaptive response was observed
in cells of patients with Marfan syndrome and Elers-Danlos syndrome but not in
cells of patients with homocystinurea. Parameters of cell protection against
gamma-irradiation at radioadaptive response were similar to those obtained in
cells pretreated with interferon. These data indicate, first, the possibility
that repair pathways and the radioadaptive response are independent and second,
that there are common pathways of protection upon radioadaptive response and the
antimutagenic action of interferon.
PMID- 10779917
TI - [Computer system for simulating population dynamic patterns of polygenes and
mobile genetic elements upon truncation selection for a quantitative trait].
AB - A computer system was developed for simulation of population dynamics of
interacting polygene patterns and mobile genetic elements (MGEs) under selection
for a quantitative trait. The system is stochastic (Monte Carlo) and takes into
account the main sources of random change in the patterns (recombinations,
transpositions, excisions), genetic drift, and determined trends of selection and
other genetic processes in a finite population. Using this model, it is possible
to analyze the dynamics of many population parameters that cannot be
experimentally estimated: frequencies of polygenic alleles, proportions of
adaptive and random fixations, average heterozygosities of polygenes and MGEs,
coefficient of inbreeding, heritability, etc. In addition, the model can be used
to test various hypotheses on polygene-MGE interaction.
PMID- 10779918
TI - [Truncation family selection and nonsystematic inbreeding leads to a rapid
fixation of a pattern of mobile genetic elements in a computer model].
AB - A computer simulation model of the population dynamics of a polygenic system and
a pattern of mobile genetic elements (MGEs) under directional truncation
selection for a quantitative trait was developed. Modifier MGEs were shown to be
rapidly and adaptively fixed (or lost) together with the modified polygenes.
Marker MGEs and independent MGE copies were fixed and lost just as rapidly but in
a random manner. Using specific marking of initial haploid genomes and direct
computing of the mean proportion of identical encounters at each locus in each
generation, it was shown that the mean nonselective inbreeding coefficient F(n)
dramatically increases in the course of selection, reaching values 0.7-0.9 in 15
20 generations. As a result, adaptive homozygotization of polygenes and modifier
MGEs and random homozygotization of marker MGEs, independent MGE copies, and all
other genes of the genome occurs. These results confirm the hypothesis on the
"champion" polygene pattern advanced earlier to explain the data of selection
experiments.
PMID- 10779919
TI - [Possibilities of selection with an increase in frequency of meiotic
recombination (simulation and experiment)].
AB - Polymorphism of rec genes, modifier genes of recombination frequency (rf), was
analyzed. Genetic population analysis was used to estimate the efficiency of some
schemes of direct and indirect selection for higher rf in a marked chromosomal
region. A new modification of the cyclic selection scheme, based on selection of
double recombinant marker genotypes in the offspring of self-fertilized plants,
was found to be most effective in many cases. This indirect selection scheme was
studied in more detail using deterministic and stochastic computer simulation.
Effects of various factors on the efficiency of the modified scheme were
analyzed. These factors were different degrees of cross-fertilization,
differential adaptation of recombinant and non-recombinant gametes and zygotes,
linkage between marker genes and rec genes, and environmental variation of rf.
Sample sizes and the number of crosses required for a stable rf increase in
experiment were estimated. Statistical properties of two new modified tests for
comparison of rf values were studied. An experiment with marker forms of tomato
were conducted taking into account the recommendations following from the results
of simulation.
PMID- 10779920
TI - [Analysis of polymorphism of the D11S2008 locus of the catalase gene in patients
with hypertension and ischemic heart disease in non-insulin-dependent diabetes
mellitus in the Muscovite population].
AB - The allele and genotype frequency distributions of the D11S2008 tetranucleotide
microsatellite linked with the catalase (CAT) gene were compared between patients
with insulin-dependent diabetes mellitus (IDDM) with (N = 72) and without (N =
82) coronary heart disease (CHD), and between IDDM patients with normal arterial
tension (N = 82) and with arterial hypertension (N = 42). In total, eight alleles
were found. The alleles varied in length from 120 to 148 bp and included from 15
to 22 tetranucleotide repeats. The groups did not differ in D11S2008 allele and
genotype frequencies; the only exception was that the frequency of genotype 18/19
in patients with CHD (31.9%) was significantly higher than in the controls
(18.3%). Thus, the D11S2008 polymorphic locus located in proximity to the
catalase gene proved to be weakly associated with CHD, but not associated with
arterial hypertension, in IDDM patients. Genotype 18/19 was associated with a
higher risk of CHD.
PMID- 10779921
TI - [Stability of expressing the nptII gene in transgenic tobacco plants (nicotiana
tabacum L.) with multiple T-DNA insertions].
AB - The stability of nptII gene expression was assessed in transgenic tobacco plants
with multiple T-DNA insertions. The plants were obtained by self-pollination in
the first (T1) and second (T2) generations and also in F1 from crossing T1
plants. The multiple copies showed stable Mendelian inheritance.
PMID- 10779922
TI - Life expectancy.
PMID- 10779923
TI - Health status of children.
PMID- 10779924
TI - Health in mid-life.
PMID- 10779925
TI - Health among older adults.
PMID- 10779926
TI - Psychological health--depression.
PMID- 10779927
TI - Income inequality and mortality among working-age people in Canada and the US.
PMID- 10779928
TI - Personal health practices: smoking, drinking, physical activity and weight.
PMID- 10779929
TI - Health care services--recent trends.
PMID- 10779930
TI - Collaborative, individualized assessment.
AB - Collaborative, individualized assessment is an approach to psychological
assessment in which the assessor and the client work together to develop
productive understandings. Collaboration is a means of individualizing the
assessment--its process, resulting suggestions, and written accounts. In this
approach, life events are regarded as primary data. Test scores, categories, and
related research are used as bridges into a particular life and as tools for then
exploring that life. This article, an invited Master Lecture presented at the
1999 Society for Personality Assessment (SPA) meeting, presents examples of
contextualizing, intervening, describing in life-world terms, and writing
individualized reports with suggestions. Historical struggles to promote
individualized assessment and current openness to its practices, especially
within SPA, are mentioned. A hermeneutic approach to impression formation is
described.
PMID- 10779931
TI - Interobserver agreement, intraobserver reliability, and the Rorschach
Comprehensive System.
AB - Interrater agreement and reliability for the Rorschach have recently come under
increasing scrutiny. This is the second report examining methods of Comprehensive
System reliability using principles derived from observational methodology and
applied behavioral analysis. This study examined a previous nonpatient sample of
20 protocols (N = 412 responses) and also examined a new clinical sample of 20
protocols (N = 374 responses) diagnosed with Research Diagnostic Criteria.
Reliability was analyzed at multiple levels of Comprehensive System data,
including response-level individual codes and coding decisions and ratios,
percentages, and derivations from the Structural Summary. With a number of
exceptions, most Comprehensive System codes, coding decisions, and summary scores
yield acceptable, and in many instances excellent, levels of reliability.
Limitations arising from the nature of Rorschach data and Comprehensive System
coding criteria are discussed.
PMID- 10779932
TI - Responses of Japanese and American university students to the STAI items that
assess the presence or absence of anxiety.
AB - Symptom endorsements and item response patterns on the anxiety-present and
anxiety-absent items of the State-Trait Anxiety Inventory Form Y (Spielberger,
1983) for 149 Japanese (99 living in Japan and 50 studying in the United States)
and 76 American university students were compared. Although mean scores for the
state and trait anxiety-absent items were comparable for Japanese students living
in Japan and Japanese international students studying in the United States, the
scores of both Japanese groups were significantly higher than those of American
students. These differences were attributable to much higher scores of Japanese
students on anxiety-absent items that corresponded to a lack of positive
feelings. Japanese students had a tendency to inhibit positive (anxiety-absent)
feelings, resulting in higher anxiety scores. Responses to anxiety-present and
anxiety-absent items should be considered independently in scoring anxiety
scales.
PMID- 10779934
TI - Origin and history of an early TAT card: picture C.
AB - The origin and history of Picture C is reviewed, and the role that David Ricks
played in preserving many original TAT materials is presented. I suggest that a
process similar to that employed with Picture C may have been used in the
development of the other "old standbys." The unusual directions for the use of
Picture C may possibly suggest awareness by C. D. Morgan and Murray of Schwartz's
earlier work with the picture-story technique.
PMID- 10779933
TI - Coping, mood, and aspects of personality in Spanish translation and evidence of
convergence with English versions.
AB - Research on stress and its influence on health and well-being has flourished for
several decades, examining as predictors such psychosocial variables as
personality and coping. This work now often targets multiethnic samples. Because
many potential participants lack facility in English, a need exists for
translations of measures into other languages. We translated 6 instruments into
Spanish and studied their characteristics. Of these, 3 were measures of
personality qualities: the Life Orientation Test--Revised (Scheier, Carver, &
Bridges, 1994), the Behavioral Inhibition/Behavioral Activation Scales (Carver &
White, 1994), and the Measure of Body Apperception (Carver et al., 1998). The
others were the Brief COPE (Carver, 1997), the Center for Epidemiological Studies
-Depression Scale (Radloff, 1977), and an abbreviated version of the Profile of
Mood States (McNair, Lorr, & Droppelman, 1971). Correlations between English and
Spanish versions in bilingual samples were all above. 72, except for the COPE's
Behavioral Disengagement scale. Alpha reliabilities of the Spanish versions were
comparable to those of the English versions. Correlations among measures in a
sample of cancer patients were similar across languages.
PMID- 10779935
TI - The MMPI-2 in Peru: a normative study.
AB - In this study, we compared a Peruvian normative group to the standard Minnesota
Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham,
Tellegen, & Kaemmer, 1989b) U.S. normative sample. The MMPI-2 Hispanic Version
was administered under standardized conditions to participants with a wide range
of age, educational, occupational, and socioeconomic levels. Between the 2
samples, there was a high degree of similarity across most basic and
supplementary scales. Elevations (Ts = 60-65) were found on Scale F for men and
women and Scales Mf and MDS for women only. For both men and women, small
elevations (Ts = 55-60) were found on several other scales. The differences were
consistent with those found in other Latin American populations. The results of
this study suggest that the adaptation of the MMPI-2 with the U.S. norms is
appropriate for use in Peru.
PMID- 10779936
TI - Exploring the factor structure of the Mood and Anxiety Symptom Questionnaire
(MASQ).
AB - L. A. Clark and Watson (1991) proposed a tripartite model of anxiety and
depression defined in terms of common symptoms relating to general distress,
anxiety-specific symptoms of hyperarousal, and depression-specific symptoms of
low positive affect and loss of interest. To aid the measurement of and
discrimination between anxiety and depression they developed the Mood and Anxiety
Symptom Questionnaire (MASQ). Although potentially useful, the MASQ is still in
an early stage of development, and there is an indication that a discrepancy
exists between items and scales. Therefore, the aim of this study was to explore
the items and factors of the MASQ and determine whether a pattern similar to that
suggested by L. A. Clark and Watson would emerge. Factor analysis of the MASQ
revealed 3 factors relating to general distress, positive affect, and anxious
arousal. Inspection of the individual items indicated that some refinements are
required.
PMID- 10779937
TI - Assessing achievement, affiliation, and power motives all at once: the Multi
Motive Grid (MMG).
AB - In this article, we introduce the Multi-Motive Grid (MMG), a new diagnostic tool
to measure motives with respect to their hope and fear components. The MMG
combines features of the Thematic Apperception Test (TAT) with features of self
report questionnaires. Similar to the TAT, a set of 14 pictures representing a
balanced set of achievement-arousing, affiliation-arousing, and power-arousing
situations is presented together with a set of statements representing important
motivational states. Six motive scores can be calculated: hope of success (HS)
and fear of failure (FF) for the achievement motive, hope of affiliation (HA) and
fear of rejection (FR) for the affiliation motive, and hope of power (HP) and
fear of power (FP) for the power motive. Results of factor analyses suggest a 3
factor solution, with a general fear factor (FF, FR, FP), a factor combining the
hope components of achievement and power (HS and HP), and a third factor
representing HA, but the 6 a priori factors also reflect a sound structural
model. Reliability data show that the internal consistency and retest reliability
of the MMG scales satisfy traditional standards. External validity of the MMG has
been established in all 3 motive domains. Three separate studies document that
(a) individuals high in resultant achievement motivation perform better and
report more flow experience, (b) individuals high in resultant power motivation
profit more from a leadership training program, and (c) individuals high in
resultant affiliation motivation recollect more highly memorable affiliative
themes.
PMID- 10779938
TI - Predicting parenting behaviors from Antisocial Practices content scale scores of
the MMPI-2 administered during pregnancy.
AB - This article examines the relation between scores on the Antisocial Practices
(ASP) content scale of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2;
Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) and parenting behaviors in
a sample of low-income women. During pregnancy, 141 women were administered the
MMPI-2 and then placed into 1 of 3 groups: an antisocial, nonclinical, or
clinical control group. When their children were 13 and 24 months old, antisocial
mothers were observed to be less understanding and more hostile and harsh in
their parenting styles than mothers in the other groups. The nonclinical and
clinical control groups did not differ on any measures. Other MMPI-2 measures of
antisocial behavior were not predictive of harsh parenting styles. These findings
support the predictive and construct validity of the ASP content scale of the
MMPI-2.
PMID- 10779940
TI - Implementing Orlando's nursing theory: a pilot study.
AB - 1. Implementing Orlando's Nursing Theory results in positive, patient-centered
outcomes. 2. Orlando's Nursing Theory provides a "road map" for nursing staff to
use when approaching patients. 3. Patients' levels of immediate distress decrease
significantly when Orlando's Nursing Theory is used.
PMID- 10779939
TI - Psychiatric hospitalization and process description: what will nursing add?
AB - 1. Inpatient treatment programs operating in the managed care environment must
clearly articulate their treatment outcomes and the processes of care that are
connected to these outcomes. 2. The work of inpatient psychiatric nurses can be
organized and articulated through the therapeutic processes of the Four S Model:
Safety, Structure, Support, and Symptom Management. 3. Nurses are vital
contributors to the inpatient treatment process, but will be marginalized if they
are unable to articulate how their interventions contribute to the positive
treatment outcomes.
PMID- 10779941
TI - Psychopathology and behavioral problems in mental retardation.
AB - 1. The lack of psychiatric services for the mentally retarded is of particular
concern for advanced practice nurses in psychiatry. 2. Prevalence of
psychopathology and behavioral problems in the mentally retarded appears to be
significant. 3. For purposes of diagnostic clarity, a thorough mental status and
neurological examination specifically devised for the mentally retarded
population must be utilized.
PMID- 10779942
TI - Continuous quality improvement to an electroconvulsive therapy delivery system.
AB - 1. ECT is known to be highly effective in relieving severe depression; however,
there are few published articles focusing on nursing care of patients receiving
ECT. 2. Education is an important component of nursing care. Lack of information
about ECT can cause a high level of anxiety and reluctance to consent to ECT. 3.
Using the Continuous Quality Improvement Model, nurses can improve the quality of
a whole system of care delivery.
PMID- 10779943
TI - [Internal ribosome entry sites in viral and cellular RNA].
PMID- 10779944
TI - [Bacterial toxins and their use].
PMID- 10779945
TI - ["Translesion synthesis", or molecular "steeplechase"].
PMID- 10779946
TI - [An edited segment of the kinetoplast gene MURF4 (ATPase 6) in leishmania has a
similar structure].
PMID- 10779947
TI - [Point mutations in region 663-666 of intron 6 or the tryptophan oxygenase gene,
connected with a series of mental disorders, disrupts the transcription factor
YY1 binding site].
PMID- 10779948
TI - [Analysis of foreign epitopes inserted in HBcAG. Possible routes for solving the
problem of chimeric core particle self assembly].
PMID- 10779949
TI - [Prediction of the exon-intron structure by comparing nucleotide sequences from
various genomes].
PMID- 10779950
TI - [Mutual effect of oligonucleotides and fluorescent probes on the effectiveness of
hybridization with oligonucleotides, immobilized on biological microchips].
PMID- 10779951
TI - [Statistical analysis of complete bacterial genomes: palindromes and systems of
restriction-modification].
PMID- 10779952
TI - [Software for analyzing bacterial genomes].
PMID- 10779953
TI - [Genomic organization of the suppressor gene for tumor growth ING1].
PMID- 10779954
TI - [Environment of the 5'-terminal nucleotide of the mRNA codon at P and E-sites of
the human ribosome: crosslinking with pUUUGUU derivatives, bearing a
photoactivated group on the uracil residue or on 5'-phosphate].
PMID- 10779955
TI - [Specific endonuclease activity of integrase encoded by MDG4 (gypsy)
retrotransposon].
PMID- 10779956
TI - [Proteins, tightly bound with a transcribed segment of rDNA in chromatin from
isolated nuclei, nucleoids and nucleoproteins of human lymphocytes. Isolation and
partial characteristics of candidate proteins].
PMID- 10779957
TI - [Analysis of genes, coding for DNA gyrase from the mycoplasma Acholeplasma
laidlawii PG-8B].
PMID- 10779958
TI - [Local duplication of genes with insertion of a complex microsatellite].
PMID- 10779959
TI - [Optical properties of fluorochromes, promising for use in biological
microchips].
PMID- 10779960
TI - [Ethidium bromide binding with native and denatured poly(dA)poly(dT)].
PMID- 10779961
TI - [Mutation of p53 is necessary for stable transformation of REF52 cells by myc+ras
oncogenes].
PMID- 10779962
TI - [Properties of envelope protein of the K1 Kazakh strain of tobacco mosaic virus].
PMID- 10779963
TI - [Detection and characteristics of defective interfering RNA associated with
cocksfoot mottle sobemovirus].
PMID- 10779964
TI - [Analysis of genomic variability of planted Panax ginseng by RAPD].
PMID- 10779965
TI - Working and buying at home.
PMID- 10779966
TI - How's that about incentives and comp?
PMID- 10779967
TI - Facility design, substance abuse also factors in forklift incidents.
PMID- 10779968
TI - Developing a customer-first attitude.
PMID- 10779969
TI - Applying OH&S standards and guidelines.
PMID- 10779970
TI - Online telecommuting resources.
PMID- 10779971
TI - Braced for the fall.
PMID- 10779972
TI - Sky-high security.
PMID- 10779973
TI - Tie-back triumph.
PMID- 10779974
TI - Say no to noise.
PMID- 10779975
TI - A new generation.
PMID- 10779976
TI - Basics of head and face protection.
PMID- 10779977
TI - Eyewear saves a welder's sight.
PMID- 10779978
TI - Safety beyond OSHA requirements.
PMID- 10779979
TI - Get moving--and fast.
PMID- 10779980
TI - Taking control.
PMID- 10779981
TI - Updating sharps safety.
PMID- 10779982
TI - Auditing OSHA's proposed self-auditing policy.
PMID- 10779983
TI - Expanding campus safety objectives.
PMID- 10779984
TI - Pain: above all, do no harm, or make sure the result is worthy of the suffering.
PMID- 10779985
TI - IGF1 and leukemia.
PMID- 10779986
TI - Cardiotoxicity in children after bone marrow transplantation.
PMID- 10779987
TI - Pain variations during cancer treatment in children: a descriptive survey.
AB - Structural interviews were conducted with 66 children and their families to
investigate how the experience of pain varied during cancer treatment. At
diagnosis, 49% experienced cancer-related pain. Intense pain was more common at
the beginning of treatment when it was often believed that pain treatment could
be better. Procedure- and treatment-related pain were the major problems
initially. Procedural pain gradually decreased, but treatment-related pain was
constant and dominating. For some procedures pain was rated highest initially,
lower during the second period, and higher again during the final part of
treatment. Pain intensity measurement was seldom performed, and parents
increasingly considered themselves better judges of their child's pain than
professionals. Increased knowledge about pain and pain treatment in children with
cancer, where most pain is iatrogenic, will help us to meet the needs and demands
of children and parents, and to reduce pain to a minimum.
PMID- 10779988
TI - Paternal employment in agriculture and childhood kidney cancer.
AB - This paper explores the hypothesis that there is an association between risk of
childhood kidney cancer and paternal employment in occupations that have
potential for exposure to herbicides and/or pesticides. In contrast to a previous
study using paternal occupations at the time of the child's death, no significant
association was found between such potential paternal exposures (using paternal
occupations at the time of the child's birth) and the risk of cancer of the
kidney in childhood (OR 0.88, 95% CI 0.20-3.84). In addition, this paper
quantifies the extent to which paternal occupational information on death
certificates can be used as a proxy for paternal occupation at birth and how such
misclassification could affect risk estimates. An example is given showing how a
recently reported association between kidney cancer and paternal agricultural
employment may have been overestimated as a result of the use of death
certificate information.
PMID- 10779989
TI - Obesity in leukemia survivors: the familial contribution.
AB - A high prevalence of obesity in survivors of acute lymphoblastic leukemia (ALL)
has been described, but genetic and social influence in obesity has not been
analyzed in this group of patients. The authors studied a population of 33 long
term (25 females, 8 males) in first remission who had reached their final height.
All patients received cranial irradiation as part of their central nervous system
(CNS)-directed therapy and no patient received growth hormone. The body mass
index (BMI: weight/height2) of patients and their biological parents was
calculated and submitted to statistical analysis. Obesity was defined as BMI
greater than the 85th centile. No excessive obesity was found among the males at
final height. Fifty-six percent of the females were obese. In this group of 14
obese female survivors 59% had obese mother, but only 14% had obese fathers. The
results indicate a significant maternal predisposition to obesity.
PMID- 10779990
TI - Male gonadal function in survivors of childhood Hodgkin and non-Hodgkin lymphoma.
AB - The aim of this study was to investigate the impact of therapy on long-term
gonadal function of young people cured of childhood lymphomas and to assess
whether a prepubertal state during the treatment protects the gonads from
chemotherapy and/or radiotherapy late effects. Clinical evaluation, semen
analysis, and endocrine status were studied in 20 survivors of childhood
lymphomas. Five patients received Inverted Y radiotherapy, 2320 cGy (1550-4000);
all 20 received chemotherapy as follows: MOPP/ABVD protocol, 9 patients; COMP
protocol, 5 patients; MOPP protocol, 3 patients; other protocols, 3 patients.
Semen analysis results were as follows: normal values, 4/20 patients;
oligospermia, 8/20 patients; azoospermia, 8/20 patients; FSH above normal level,
10/20 patients; 4/5 who received Inverted Y irradiation were azoospermic and 1
was severely oligospermic. Treatment damage to the testis involves tubular
germinal elements. Radiotherapy and chemotherapy combinations that included
nitrogen mustard or cyclophosphamide were associated with high rates of
oligospermia and azoospermia. MOPP/ABVD combination did not have a significant
better outcome of sperm counts compared to MOPP alone. Age at chemotherapy did
not correlate with the sperm count; hence a prepubertal state did not protect the
gonad from the late effects of treatment.
PMID- 10779991
TI - Clinical presentations of infection by the human herpesvirus-7 (HHV-7).
AB - Reports on the clinical picture of primary infection with the human herpesvirus-7
(HHV-7) are scarce. A heterogenous population of 478 patients (1 month-14 years)
was examined for the presence of an acute HHV-7 infection. A variety of clinical
pictures can be observed during primary infection with HHV-7, such as exanthema
subitum and mononucleosis-like syndrome. The authors describe in two children,
for the first time, the presentation of HHV-7-infection as an acute exacerbation
or relapse of a patient's chronic disease. The hematological changes for the
respective clinical presentations during HHV-7 infection are reported.
PMID- 10779992
TI - Decreased insulin-like growth factor-I receptor sites on circulating mononuclear
cells from children with acute leukemia.
AB - Insulin-like growth factor-I (IGF-I) is a known mitogen for various cell types,
including those of the hematopoietic cell system. To study the role of IGF-I in
the neoplastic process of leukemia in children, the authors have determined the
number of IGF-I binding sites on circulating mononuclear cells of children with
acute leukemia as compared to normal children, using binding assays. The IGF-I
binding sites per cell on peripheral mononuclear cells of children with leukemia
decreased compared to those of the control group (411 +/- 73 and 1334 +/- 227,
respectively, p < .001), while their affinity increased (Kd = 0.14 +/- 0.04 and
0.43 +/- 0.16, respectively, p = .05). Furthermore, in the patients, the number
of the IGF-I binding sites was significantly lower in the subgroup of the
peripheral mononuclear cells, which included lymphocytes and monocytes, as
compared to their number in the peripheral blast cells (254 +/- 43.6 and 536 +/-
98.6, respectively, p = .02). A significant reduction was found in serum GHBP
levels in the patients as compared to the controls (28.21 +/- 1.93 and 35.83 +/-
2.90, respectively, p = .02), while serum IGF-I and growth hormone levels were
similar in patient and control groups. These results suggest a possible
involvement of IGF-I in childhood acute leukemia, but further studies are needed
to establish whether IGF-I plays a role in this disease.
PMID- 10779993
TI - Lymphohistiocytic anaplastic large cell lymphoma stage I: long-term survival
after resection alone.
AB - A 17-year-old female presented with axillary lymphoadenopathy, which, on biopsy,
demonstrated an anaplastic large cell lymphoma of the lymphohistiocytic type
(ALCL-LH). The tumor cells expressed the CD30 antigen and reacted with the ALK1
antibody, suggesting the presence of the nucleophosmin-anaplastic large cell
lymphoma kinase (NPM/ALK) fusion protein. No other adenopathy was found.
Following a wide excision of the lymph node and without postoperative treatment,
the patient remains free of disease 5 years later. This case demonstrates the
potential curability of patients with early stages of ALCL by local treatment.
PMID- 10779994
TI - A case of malignant lymphoma in a patient with high levels of CA125 and CA19-9.
AB - The authors encountered a case of malignant lymphoma in a patient who had high
levels of CA125 and CA19-9. These tumor markers showed almost identical changes
during the clinical course of the disease. To date, there has been no
investigation of these markers as they relate to malignant lymphoma.
Unfortunately, the normal values of CA125 and CA19-9 in children were not known
and thus this case could not be compared with disease-free children. This study
shows CA125 and CA19-9 levels of the children that do not have the malignant
diseases, and reports on one case of malignant lymphoma in a patient who
presented with high levels of these markers.
PMID- 10779995
TI - Secondary leukemia in a child with neuroblastoma while on oral etoposide: what is
the cause?
AB - To date little has been reported about the risk of therapy-related leukaemia (t
AML) in children receiving oral etoposide therapy. The authors present a case of
t-AML that developed in a child with metastatic neuroblastoma 18 months after he
received oral etoposide, given for palliation purpose. The leukemic blasts were
examined by morphological, immunohistochemical, cytogenetic, and molecular
genetic analyses. Although the t-AML developed following oral etoposide therapy,
the child had previously received high-dose, multiagent chemotherapy, and
rearrangement of the MLL gene was not demonstrated. The use of modern multiagent
therapy often makes it difficult to appropriately apportion blame for causation
of specific side effects. Moreover, the etiology of t-AML and mechanism of
leukemogenesis are likely to be multifactorial and complex. Further studies on
the precise association with different therapies are thus needed. Oral etoposide
remains an effective palliative agent and its usage should not be excluded
without most careful consideration of the risks.
PMID- 10779996
TI - [ATP and polyphosphate-dependent bacterial NAD+-kinases].
AB - Measurable levels of activity of NAD+ kinases of actinomycetes Micrococcus luteus
and Corynebacterium ammoniagenes were observed after substituting inorganic
tripolyphosphate for ATP, whereas the enzyme from the eubacterium Escherichia
coli was not active with this substrate. Gradient PAGE found two molecular
isoforms of NAD+ kinase in C. ammoniagenes and E. coli; four forms were found in
M. luteus. All isoforms of this enzyme found in C. ammoniagenes and M. luteus
displayed a NADP-synthesizing activity in the presence of either ATP or
tripolyphosphate. Because of its capability of utilizing inorganic
tripolyphosphate, M. luteus is the most promising NADP producer organism.
PMID- 10779997
TI - [Enzymatic hydrolysis of willow treated with a steam burst without preliminary
water extraction with a high concentration of substrate].
AB - A laboratory reactor equipped with a screw press was used for hydrolysis of steam
SO2 exploded willow Salix caprea by a composition of Trichoderma reesei and
Aspergillus foetidus enzyme preparations at high substrate concentrations.
Optimal conditions providing the maximal volume of hydrolysis syrup with maximal
sugar concentrations were determined. Two different hydrolysis procedures were
developed in order to exclude initial washing of steam-pretreated plant raw
material by large volumes of water, which is necessary to eliminate the
inhibitory effect of explosion by-products on enzymatic hydrolysis. The first
procedure included a one-hour-long enzymatic prehydrolysis of the substrate, then
separation of sugar syrup containing 40-60 g/l of glucose, 20-25 g/l of xylose,
and up to 10% of disaccharides, as well as up to 35% of the initial enzymatic
activity, then addition of a diluted acetate buffer (pH 4.5), and subsequent
hydrolysis of the substrate by the adsorbed enzymes leading to the final
accumulation of up to 140 g/l glucose and up to 15 g/l xylose. In the second
scenario, the exploded willow was initially adjusted by alkali to pH 4.5 and then
hydrolyzed directly by added enzymes for 24 hours. This procedure resulted in a
nearly total polysaccharide hydrolysis and accumulation of up to 170 g/l glucose
and 20 g/l xylose. The reasons of inhibition of enzymatic hydrolysis are
discussed.
PMID- 10779998
TI - [Isolation and purification of acetolactate synthase and acetolactate
decarboxylase from a Lactococcus lactis culture].
AB - Enzymes catalyzing the synthesis and subsequent transformation of alpha
acetolactate (AcL)--acetolactate synthase (AcLS) and acetolactate decarboxylase
(AcLDC)--were isolated and partially purified from the cells of lactic acid
bacteria Lactococcus lactis ssp. lactis biovar. diacetylactis strain 4. The
preparation of AcLS, purified 560-fold, had a specific activity of 358,300 U/mg
protein (9% yield). The preparation of AcLDC, purified 4828-fold, had a specific
activity of 140 U/mg protein (4.8% yield). The enzymes exhibited optimum activity
at pH 6.5 and 6.0, respectively (medium, phosphate buffer). The values of
apparent Km, determined for AcLS and AcLDC with pyruvate and AcL, respectively,
were equal to 70 mM and 20 mM. AcLS appeared as an allosteric enzyme with low
affinity for the substrate and a sigmoid dependence of the activity on the
substrate concentration. In the case of AcLDC, this dependence was hyperbolic,
and the affinity of the enzyme for its substrate was high (Km = 20 mM). Leucine,
valine, and isoleucine were shown to be activators of AcDLC.
PMID- 10779999
TI - [Comparative study of soluble and immobilized phenol oxidase from the fungus
Mycelia sterilia IBR 35219/2].
AB - Phenol oxidase (EC 1.14.18.1) from the microscopic fungus Mycelia sterilia IBR
35219/2 was immobilized using glutaraldehyde on macroporous silica carriers. The
enzyme immobilized on amino-Silochrome SKh-2 or aminopropyl-Silochrome 350/80
exhibited maximum activity. Soluble and immobilized phenol oxidases were
compared. Compared to the soluble enzyme, the activity of which was optimum at pH
5.5, immobilized phenol oxidase exhibited optimum activity under slightly more
acidic conditions (pH 5.2). Immobilization considerably increased the enzyme
stability. Both soluble and immobilized forms of phenol oxidase from M. sterilia
IBR 35219/2 catalyze oxidative conversion of phenolic compounds of the green tea
extract.
PMID- 10780000
TI - [Determining role of media in peroxide oxidation of aromatic type antioxidants
with participation of methemalbumins].
AB - Participation of the complexes of hemin and albumins (or delipidated albumins) in
peroxidation of aromatic free radical scavengers and antioxidants was studied at
varying hemin/albumin ratios. The radical-scavenging amines included o
phenylenediamine (OPD) and tetramethylbenzidine (TMB); the antioxidants, gallic
acid (GA) and GA polydisulfide (GAPD). Peroxidation reactions were carried out in
buffered physiological saline (BPS) supplemented with 2% dimethylsulfoxide(DMSO),
pH 7.4 (medium A), or in 40% aqueous dimethylformamide (DMF), pH 7.4 (medium B).
In all systems involving methemalbumins, kinetic constants (kcat), Michaelis
constants (kM), and the ratios thereof (kcat/kM) were determined for OPD
oxidation in medium A and TMB oxidation in medium B. Oxidation of OPD, GA, and
GAPD in medium A was characterized by a decrease in the catalytic activity of
hemin after the formation of hemin-albumin complexes. Conversely, oxidation of
TMB and OPD in medium B was distinguished by pronounced activation of hemin
present within methemalbumins.
PMID- 10780001
TI - [Melanin pigments of the fungi Paecilomyces variotii and Aspergillus
carbonarius].
AB - Pigments synthesized by micromycetes Paecilomyces variotii and Aspergillus
carbonarius are true melanins. Copper ions and bicyclic phenolic compounds
stimulated melaninogenesis, whereas benzotriazole inhibited this process.
Precursors of melanin pigments were obtained and identified. p-Hydroxybenzoic
acid was shown to be the main product of melanin degradation. Melanins of these
fungi are concluded to belong to the dihydronaphthalene group.
PMID- 10780003
TI - [Furane compounds formed upon heating highly-sugared fermented media].
AB - 5-Methylfurfural diethyl acetal, 5-methylfuran acid ester, and 4-hydroxypentanoic
acid ethyl ester were first identified in high-sacchariferous corn media
subjected to alcoholic fermentation by Mucor X-I culture and in aged sweet wines
by means of GLC, GLC-MS, and TLC, as well as by UV and IR spectroscopic
examinations. These substances are products of enzymatic esterification of sugars
followed by their dehydration by heat treatment or long seasoning of grape wines.
PMID- 10780002
TI - [Inactivation of polygalacturonase in the process of growth of the yeast
Saccharomyces pastorianus].
AB - The effect of exogenous glucose addition on polygalacturonase (EC 3.2.1.15)
activity in the culture medium of Saccharomyces pastorianus was studied. An rapid
but transient decrease in the enzyme activity was observed after 9-12 h after
adding glucose to the culture medium. This effect was not associated with protein
degradation or modification in the spectrum of secreted proteins. Ethyl acetate
appeared in the culture medium during this period.
PMID- 10780004
TI - [Transformation of lignins from grape solids during alcoholic fermentation].
AB - Conversion of lignins contained in solid parts of Rkatsiteli grapes (crests,
seeds, and skin) during alcoholic fermentation by wine yeast in Reader's medium
was studied. Various species of wine yeast were used: Saccharomyces oviformis, S.
vini Kakhuri 42, S. chodati Teliani 79, and S. uvarum Tsinandali 77. We found
that lignins from solid parts of grapes are partially decomposed during alcoholic
fermentation, which releases low-molecular-weight aromatic compounds into the
medium. A peculiar feature of lignin decomposition during alcoholic fermentation
is the formation of reduction products.
PMID- 10780005
TI - [Extracellular proteinases and chitinases, produced by a Streptomyces kurssanovii
culture].
AB - Extracellular enzymes--a chitinase and a protease with molecular weights 22 and
32 kDa, respectively--were isolated from Streptomyces kurssanovii cells. After
purification on modified regenerated chitin, the enzymes were virtually
homogeneous according to denaturing PAGE. Both enzymes were found to degrade
chitosan.
PMID- 10780006
TI - [Microbial degradation of components of waste water from phenol-producing
industry].
AB - Processes of aerobic biodegradation of components of phenol production sewage
(phenol, acetophenone, dimethylphenylcarbinol, cumene hydroperoxide, alpha
methylstyrene, benzoate, and p-hydroxybenzoate) by bacterial strains obtained
from the collection of Saratov Institute of Biocatalysis were studied. The
metabolic reactions were shown to be oxidative and have a common catabolic
sequence (cumene hydroperoxide-dimethylphenyl-carbinol alpha-methylstyrene
acetophenone-phenyl acetate-phenol-pyrocatechol-aromatic ring breakage). Benzoate
and p-hydroxybenzoate were degraded through the formation of pyrocatechol and
protocatechuate, respectively. Metabolic pathways were similar in model mixtures
of components and sewage samples.
PMID- 10780007
TI - [Study of microbial degradation of nonionic surface-active agents in designing
technologies for purifying waste water].
AB - Studies of degradation of non-ionic surfactants (NISA) in a model purification
plant of an original design demonstrated an high rate and depth of degradation
processes compared with periodic cultivation of free or immobilized degrading
strains. A virtually complete primary degradation (99-99.5%), with destruction of
the oxyethyl moiety of the molecule, was observed. In addition, NISA molecules
were degraded to a greater extent, including considerable degradation of the
hydrocarbon radical, partial degradation of aromatic structures in Neonol, and
utilization of biologically "unyielding" fractions of commercial NISA
preparations: polyethylene glycol (PEG) and long-chain fractions of polymer
homologues.
PMID- 10780008
TI - [Effect of gas phase composition on formation of hydrocarbons by Desulfovibrio
desulfuricans].
AB - Changes in the synthesis of extracellular metabolic products generated by sulfate
reducing bacteria Desulfovibrio desulfuricans grown on a lactate-containing
mineral medium in the presence of H2 and CO2 at various volume ratios in the
gaseous phase were studied. An increase in the amount of extracellular products
synthesized by the bacteria was observed at an H2/CO2 ratio of 3:1. High
concentrations of molecular hydrogen (80-95%) in the presence of 5-20% CO2
facilitated the synthesis of hydrocarbons (alkanes) whose highest concentrations
were produced at an H2/CO2 ratio of 9:1. An increase in the initial CO2
concentration in the gaseous phase above 20% increased the amount of oxygenated
compounds in the culture.
PMID- 10780009
TI - [Effect of conditions of culturing Penicillium funiculosum G-15 on production of
extracellular glucose oxidase].
AB - Effects of conditions of Penicillium funiculosum G-15 cultivation on the
production of extracellular glucose oxidase were studied. The data showed that
surface and submerged methods of cultivation can be used for obtaining a glucose
oxidizing enzyme. The optimum conditions for submerged cultivation (25 degrees C,
initial pH 5.0, and aeration of 3 l/l per min) and surface cultivation
(temperature 25 degrees C and initial pH 4.0) providing the maximum levels of
glucose oxidase synthesis were determined.
PMID- 10780010
TI - [Effect of conditions of culturing Pseudomonas rathonis T on characteristics of a
biosensor for determining anionic surface-active agents].
AB - The dependence of the sensitivity of a microbial biosensor of anionic surfactants
(AS) on the growth phase of Pseudomonas rathonis T, a strain capable of degrading
surfactants, was studied. Correlations were found between the optimum values of
temperature and pH of microbial growth, substrate utilization, and functional
performance of the microbial biosensor. These results allow the process of AS
detection to be optimized.
PMID- 10780011
TI - [Ochratoxin A: study of grain contamination].
AB - Ochratoxin A was quantitatively monitored in grain extracts by indirect solid
phase enzyme immunoassay with the use of an immobilized conjugate of the toxin
with gelatin and polyclonal rabbit antibodies raised against the ochratoxin A-BSA
conjugate. This monitoring found that 1.7 to 18.5% of the samples were
contaminated with the toxin at a concentration of 25.9-291.7 micrograms/kg. An
analysis of forage grain found ochratoxin A at concentrations of 440-3250
micrograms/kg.
PMID- 10780013
TI - [Preparation and immunochemical properties of monoclonal antibodies to potato
ring rot pathogen Corynebacterium sepedonicum].
AB - Five stable hybridoma lines producing monoclonal antibodies to Corynebacterium
sepedonicum were obtained. The specificity of monoclonal antibodies obtained was
characterized. Interactions of the antibodies with native cells and antigenic
preparations from bacterial cell extracts were studied. The epitope specificity
of these antibodies to their recognized antigens and the use of the antibodies in
advanced immunodiagnostic assays are discussed.
PMID- 10780012
TI - [Effect of methyljasmononate on induction of late-blight resistance of potatoes
using arachidonic acid].
AB - Methyl ester of jasmonic acid (Me-JA) influences the induced resistance of potato
tubers to late blight caused by Phytophthora infestans. Treatment of potato tuber
disk surface with Me-JA solution or exposure to an atmosphere containing Me-JA
vapors (10(-6)-10(-5) M) increased the rate of rishitin biosynthesis induced by
arachidonic acid or P. infestans. Methyl jasmonate increased the sensitivity of
potato tissue to arachidonic acid. As a result, in the presence of Me-JA, the
protective properties of arachidonic acid were observed at lower concentrations
than in the absence of Me-JA. In addition, Me-JA reduced the adverse effects of
lipoxygenase inhibitors (salicylhydroxamic acid and esculetin) on the induced
resistance of potato tubers to late blight. Therefore, the synergistic
interaction of Me-JA and biogenic elicitors can be regarded as part of a
mechanism of potato defense against diseases.
PMID- 10780014
TI - [Activity of a proteinaceous polygalacturonase inhibitor in potato plants].
AB - The activity of a protein inhibitor of polygalacturonase (PIPG) was studied in
potato tubers during storage and in potato leaves and stems during vegetation.
The activity of PIPG in tubers varied from between seasons. The activity of PIPG
during dormancy changed depending on the storage stage and temperature. As a
rule, it was higher in etiolated sprouts than in the tubers. The activity of PIPG
was slightly higher in leaves of adult vegetating plants than in stems and
decreased by the end of vegetation. These changes in the activity of PIPG are
suggested to be associated with changes in the growth rate.
PMID- 10780016
TI - [Effect of exogenous quercetin on the level of carbohydrates and amino acids in
Lycopersicon esculentum fruit].
AB - Low doses of the exogenous flavonoid quercetin increased in contents of sugars in
tomato fruits of various cultivars. The content of glucose in tomato fruits of
cv. Ukrainskii teplichnyi increased from 3.62 to 11.24% per unit dry weight.
Increases in the content of glucose were found in all tomato cultivars examined.
An analysis of qualitative and quantitative compositions of amino acids showed
that their levels were markedly decreased in fruits of quercetin-treated plants.
Our studies and data found in the literature suggest that this effect is due to
the synthesis of sugars from amino acids by gluconeogenesis. The reverse process
of sugar hydrolysis does not occur because exogenous quercetin inhibits the
activity of pyruvate kinase.
PMID- 10780015
TI - [The effect of the substance exin on development of microbial infections and
isolation of ethylene in plants].
AB - Effects of Exin on infection of tomato, potato, and cabbage plants with
Pseudomonas solanacearum and Erwinia carotovora and a fungus Sclerotium rolfsii
were studied. The treatment of infected plants with Exin caused no significant
effect on the development of the disease. Treatment with streptomycin as a
standard for comparison completely inhibited the growth of these microorganisms.
Pretreatment with Exin one to eight days before infecting inhibited the
development of diseases. The numbers of tomato and potato plants damaged among
those infected with P. solanacearum were lower by 10 and 35% respectively. In
field experiments (350 plants per variant), treatment with Exin decreased the
development of wilt caused by S. rolfsii and P. solanacearum and rot caused by E.
carotovora. Treatment with Exin activated the release of ethylene for not less
than 30 days. Possible mechanisms of the effects of Exin are discussed.
PMID- 10780017
TI - [Preparation of agar and agarose from the red algae Ahnfeltia tobuchiensis].
AB - A simple and inexpensive procedure of agar and agarose production from the red
alga Ahnfeltia tobuchiensis was developed, which needs no additional
chromatographic purification.
PMID- 10780018
TI - Explicitly modeling the effects of aging on response time.
AB - Research into the effects of aging on response time has focused on Brinley plots.
Brinley plots are constructed by plotting mean response times for older subjects
against those for young subjects for a set of experimental conditions. The
typical result is a straight line with a slope greater than 1 and a negative
intercept. This linear function has been interpreted as showing that aging leads
to a general slowing of cognitive processes. In this article, we show that the
slope of the Brinley plot is actually a measure of the relative standard
deviations of older versus young subjects' response times; it is not a measure of
general slowing. We examine current models of the effects of aging on mean
response time and show how they might be reinterpreted. We also show how a more
comprehensive model, Ratcliff's diffusion model (1978), can account for Brinley
plot regularities and, at the same time, provide an account of accuracy rates,
the shapes of response time distributions, and the relative speeds of error and
correct response times, aspects of the data about which models designed to
account for Brinley plots are mute. We conclude by endorsing a research approach
that applies explicit models to response time data in aging in order to use the
parameters of the model to interpret the effects of aging.
PMID- 10780019
TI - Accounts of the confidence-accuracy relation in recognition memory.
AB - Confidence and accuracy, while often considered to tap the same memory
representation, are often found to be only weakly correlated (e.g., Bothwell,
Deffenbacher, & Brigham, 1987; Deffenbacher, 1980). There are at least two
possible (nonexclusive) reasons for this weak relation. First, it may be simply
due to noise of one sort or another; that is, it may come about because of both
within- and between-subjects statistical variations that are partially
uncorrelated for confidence measures on the one hand and accuracy measures on the
other. Second, confidence and accuracy may be uncorrelated because they are
based, at least in part, on different memory representations that are affected in
different ways by different independent variables. We propose a general theory
that is designed to encompass both of these possibilities and, within the context
of this theory, we evaluate effects of four variables--degree of rehearsal, study
duration, study luminance, and test luminance--in three face recognition
experiments. In conjunction with our theory, the results allow us to begin to
identify the circumstances under which confidence and accuracy are based on the
same versus different sources of information in memory. The results demonstrate
the conditions under which subjects are quite poor at monitoring their memory
performance, and are used to extend cue utilization theories to the domain of
face recognition.
PMID- 10780020
TI - Meaning resolution processes for words: a parallel independent model.
AB - Lexical ambiguity research over the last two decades is reviewed, with a focus on
how that literature applies to understanding the resolution of meaning for words.
Early models of ambiguity processing dealt almost exclusively with the time
course of the effects of context on lexical access, in order to address the issue
of modularity of lexical access. Newer models of ambiguity processing accommodate
recent findings of early context effects that are contingent on both strength of
context and meaning frequency. The most important contribution of these newer
models of ambiguity processing is not to the modularity debate, but to
investigation of the range of parameters affecting the entire meaning resolution
process, including meaning access as well as the integration of meanings into
context. As an example of this approach, we describe a simple quantitative model
of meaning resolution that subsumes many other models as parametric variations.
PMID- 10780022
TI - "Work ethic" in pigeons: reward value is directly related to the effort or time
required to obtain the reward.
AB - Stimuli associated with less effort or with shorter delays to reinforcement are
generally preferred over those associated with greater effort or longer delays to
reinforcement. However, the opposite appears to be true of stimuli that follow
greater effort or longer delays. In training, a simple simultaneous
discrimination followed a single peck to an initial stimulus (S+FR1 S-FR1) and a
different simple simultaneous discrimination followed 20 pecks to the initial
stimulus (S+FR20 S-FR20). On test trials, pigeons preferred S+FR20 over S+FR1 and
S-FR20 over S-FR1. These data support the view that the state of the animal
immediately prior to presentation of the discrimination affects the value of the
reinforcement that follows it. This contrast effect is analogous to effects that
when they occur in humans have been attributed to more complex cognitive and
social factors.
PMID- 10780021
TI - In defense of abstractionist theories of repetition priming and word
identification.
AB - There is a great deal of interest in characterizing the representations and
processes that support visual word priming and written word identification more
generally. On one view, these phenomena are supported by abstract orthographic
representations that map together visually dissimilar exemplars of letters and
words (e.g., the letters A/a map onto a common abstract letter code a*). On a
second view, orthographic codes consist in a collection of episodic
representations of words that interact in such a way that it sometimes looks as
if there are abstract codes. Tenpenny (1995) contrasted these general approaches
and concluded by endorsing the episodic account, arguing that no evidence demands
that we posit abstract orthographic representations. This review reconsiders the
evidence and argues that a variety of priming and nonpriming research strongly
supports the conclusion that abstract orthographic codes exist and support
priming and word identification. On this account, episodic representations are
represented separately from abstract orthographic knowledge and contribute
minimally to these functions.
PMID- 10780023
TI - Don't look! Don't touch! Inhibitory control of eye and hand movements.
AB - Inhibitory control of eye and hand movements was compared in the stop-signal
task. Subjects moved their eyes to the right or left or pressed keys on the right
or left in response to visual stimuli. The stimuli were either central (angle
brackets pointing left or right) or peripheral (plus signs turning into Xs left
or right of fixation), and the task was either pro (respond on the same side as
the stimulus) or anti (respond on the opposite side). Occasionally, a stop signal
was presented, which instructed subjects to inhibit their responses to the go
stimulus. Stop-signal reaction times (SSRTs) were faster overall for eye
movements than for hand movements, and they were affected differently by stimulus
conditions (central vs. peripheral) and task (pro vs. anti), suggesting that the
eyes and hands are inhibited by different processes operating under similar
principles (i.e., a race between stop and go processes).
PMID- 10780024
TI - Age and individual differences in visuospatial processing speed: testing the
magnification hypothesis.
AB - Forty young adults and 40 older adults performed seven visuospatial information
processing tasks. Factor analyses of the response times (RTs) yielded a single
principal component with a similar composition in both age samples. For both
samples, regressing the mean RTs of fast and slow subgroups for the seven tasks
(18 conditions) on the corresponding mean RTs for their age group accounted for
99% of the variance. Taken together, these findings suggest that individual
differences in processing time were largely task independent. The magnification
hypothesis, a simple mathematical model of the interaction between age and
ability, is presented. This model correctly predicts the finding that in both the
young and the older adult groups, individual differences increased systematically
with task difficulty. The magnification hypothesis also explains the regression
parameters describing individual differences among young adults and predicts
correctly that equivalent parameters describe individual differences among older
adults. According to the magnification hypothesis, the RTs of slower individuals
are more affected by aging than those of faster individuals, and slower
individuals may be more at risk with respect to other biological insults (e.g.,
changes in health status) as well.
PMID- 10780025
TI - The reverse Stroop effect.
AB - In classic Stroop interference, manual or oral identification of sensory colors
presented as incongruent color words is delayed relative to simple color naming.
In the experiment reported here, this effect was shown to all but disappear when
the response was simply to point to a matching patch of color. Conversely, strong
reverse Stroop interference occurred with the pointing task. That is, when the
sensory color of a color word was incongruent with that word, responses to color
words were delayed by an average of 69 msec relative to a word presented in gray.
Thus, incongruently colored words interfere strongly with pointing to a color
patch named by the words, but little interference from incongruent color words is
found when the goal is to match the color of the word. These results suggest that
Stroop effects arise from response compatibility of irrelevant information rather
than automatic processing or habit strength.
PMID- 10780026
TI - Conceptual activation of distractors during selection is not sufficient to
produce negative priming.
AB - Negative priming (NP) occurs when responses are slower because the targets were
distractors on the preceding trial. Word-naming NP occurs only with words that
have been presented repeatedly as targets; novel words do not show NP. The
activation-inhibition explanation is that representations of repeated-word
distractors are activated already and must be inhibited; the inhibition carries
over to the next trial. If this explanation is correct, novel-word NP should
occur if the word is semantically primed (thus activating its representation)
before it occurs as a distractor. In two experiments, there was NP for words from
a repeated set, and the magnitude of NP increased when the same word could occur
as a target on consecutive trials. There was positive, rather than negative,
priming for novel-word targets that had been semantically primed as distractors.
Either the activation from semantic priming was not sufficiently strong to
require inhibition, or the activation-inhibition hypothesis does not refer to
activation of conceptual representations.
PMID- 10780027
TI - The left-to-right nature of the masked onset priming effect in naming.
AB - Two experiments were performed to investigate the nature of the masked onset
priming effect in naming, that is, the facilitation in naming latency that is
observed when a target shares the initial grapheme/phoneme with a masked prime.
Experiment 1 showed that the effect is not due to position-independent letter
priming, since the naming of nonword targets preceded by masked primes was
facilitated only if the prime shared the initial letter with the target (e.g.,
suf-SIB) and not if the prime shared the final letter (e.g., mub-SIB). Experiment
2 showed that the effect reflects the sharing of onsets rather than the initial
letter, since facilitation due to an overlap of the initial letter was observed
only for the simple onset target (e.g., penny-PASTE) for which the letter
corresponded to the onset, and not for complex onset targets (e.g., bingo-BLISS).
It is argued that the serial nature of the masked onset priming effect is best
interpreted as the planning of articulation, rather than as the computation of
phonology from orthography.
PMID- 10780028
TI - Reading aloud polysyllabic words and nonwords: the syllabic length effect
reexamined.
AB - Two experiments were run in order to reinvestigate the role of the number of
syllables in naming. Experiment 1 (word naming) showed that effects of number of
syllables on naming latency were observed for very low-frequency words but not
for high-frequency words (thus replicating Jared & Seidenberg's, 1990, finding).
In Experiment 2 (nonword naming), syllabic length effects were also obtained for
nonwords. Control experiments found no effect on the latency of delayed naming of
the same words and nonwords. These results suggest that naming does require
syllabic decomposition, at least for very low-frequency words and nonwords in
French. In particular, these data are compatible with any model of reading that
postulates that reading aloud depends on the activity of two procedures: (1) a
procedure that operates in parallel across a letter string (and does not generate
a strong syllabic length effect) and that is the predominant process in
generating responses to high-frequency words, and (2) another procedure that
operates serially across a letter string (and generates a strong syllabic length
effect) and that is the predominant process in generating responses to very low
frequency words and nonwords. These results are discussed in the context of the
multiple-trace memory model for polysyllabic word naming (Ans, Carbonnel, &
Valdois, 1998).
PMID- 10780029
TI - Implicit word activation during prerecognition processing: false recognition and
remember/know judgments.
AB - Recognition memory for spoken words is influenced by phonetic resemblance between
test words and items presented during study. Presentation of derived nonwords
(e.g., /d/ransparent or transparen/d/) on a study list produces a higher than
normal false recognition rate to base words (e.g., transparent). Test words that
share beginning phonemes with studied nonwords have more false recognitions than
do those that share ending phonemes. The latter difference has been attributed to
familiarity resulting from prerecognition processing of spoken stimuli. As a
listener hears/traens/, "transparent" may be activated as a potential solution.
In the present experiments, we minimized contributions of postrecognition
processing to this phenomenon by presenting a semantically unrelated test word
(transportation) that was also expected to be activated during prerecognition
stages of processing. The results indicated that false recognition was increased
for words presumed to be activated only during prerecognition processing.
Remember (R) and know (K) judgments revealed that the majority of studied words
were R, and the majority of false recognitions were K. The lowest proportion of R
judgments occurred for test words that were not activated during postrecognition
processing (e.g., transportation and control words).
PMID- 10780030
TI - The effects of a levels-of-processing manipulation on false recall.
AB - The present study attempted to determine the effect of a levels-of-processing
manipulation on the incidence of false recall. In Experiment 1, participants
engaged in either a vowel counting task or a concrete/abstract rating task; in
Experiment 2, participants engaged in either a vowel counting task or a category
sorting task. Results of both experiments demonstrated that participants who
engaged in a deeper level of processing (i.e., concrete/abstract ratings or
category sorting) recalled significantly more list items and critical lures. The
present findings thus lend support to theories that attribute false memories to
activation-based factors.
PMID- 10780031
TI - Much ado about mirrors.
AB - Takano (1998) has suggested four different kinds of reversal to explain why
mirrors reverse left and right and not up and down or back and front. In fact,
mirrors perform only one kind of reversal: They simply reverse about their own
planes, and reflection about one plane is equivalent to reflection about any
other, plus a translocation and rotation. The reflection of an object is termed
its enantiomorph. Perception of the enantiomorphic relation normally requires an
act, either physical or mental, of alignment. In deciding whether two objects are
enantiomorphs, there is a tendency to align them so that the reversal is about
the axis of least asymmetry. But in deciding whether a single object is one of
two possible enantiomorphic forms, people generally rotate it to some canonical
orientation. In the case of objects with defined top-bottom, back-front, and left
right axes, the canonical orientation is determined by the top-bottom and back
front axes, leaving the left-right axis to carry the reversal. The main reason
for this, I suggest, is that the top-bottom and back-front axes have functional
priority, and the left-right axis cannot be defined until top-bottom and back
front are established. This means that the latter two axes have priority in
establishing the canonical orientation. The left-right axis is usually, but not
always, the axis of least asymmetry.
PMID- 10780033
TI - Conflict of interest and respiratory care.
PMID- 10780032
TI - Mirror reversal simply explained without recourse to psychological processes.
AB - This paper proposes a simple and definitive solution to the mirror reversal
problem, "Why does a mirror reverse left and right but not up and down?" The
solution is given by combining the inversion caused by the optical process of
mirroring and the definition of the left-right axis. Thus the left-right reversal
of mirror images essentially does not involve psychological processes, in
contrast to the multiprocess hypothesis recently proposed by Takano.
PMID- 10780034
TI - Effects of respiratory impedance on the performance of bi-level pressure
ventilators.
AB - BACKGROUND: Noninvasive positive pressure ventilation (NPPV) has been studied in
several settings and shown to reduce patient morbidity associated with
endotracheal intubation. Intolerance to NPPV has been estimated at 25-33%, a
substantial proportion of attempts to ventilate noninvasively. Bi-level pressure
ventilators (BPVs) have been designed for NPPV, yet their response to changes in
respiratory impedance has not been extensively evaluated. To determine responses
of BPVs to changing impedance conditions, we tested 4 BPVs to evaluate the
potential for intolerance. We also developed a mathematical model for BPV
performance that accounted for impedance conditions, leak, pressure settings, and
inspiratory flow cutoff level. METHODS: Four BPV models at the same settings were
challenged to ventilate a triggered test lung under a range of impedance
conditions while measuring tidal volume (VT) and intrinsic positive end
expiratory pressure (auto-PEEP). The model was used to predict VT and auto-PEEP
under normal, restrictive, and obstructive conditions. RESULTS: The BPV models
tested delivered VT in a similar manner. VT decreased with decreased compliance
and increased resistance. Auto-PEEP developed with increased resistance and
compliance. The model predicted a VT delivery dependent on inspiratory flow
cutoff level. For the obstructive condition, the model predicts an optimal VT
delivery within a specific inspiratory flow cutoff range that becomes narrower
with increasing resistance. CONCLUSIONS: VT delivery and auto-PEEP generated by
BPVs are highly dependent on the prevailing impedance condition. Though there are
differences between BPV models, generally, performance was similar between the
models tested. This report suggests that knowledge of both respiratory system
impedance and the performance of the BPV in use are required to attend to
inadequate VT delivery and auto-PEEP generation. Furthermore, the model predicts
a relatively narrow range for inspiratory flow cutoff that provides adequate
ventilatory support without causing hyperinflation in patients with obstructive
conditions.
PMID- 10780035
TI - Reevaluation of continuous oxygen therapy after initial prescription in patients
with chronic obstructive pulmonary disease.
AB - BACKGROUND: Long-term oxygen therapy improves survival and quality of life in
hypoxemic patients with chronic obstructive pulmonary disease (COPD). The need
for long-term oxygen therapy should be determined when patients are medically
stable. The Third Oxygen Consensus Conference recommended reevaluating patients 1
3 months after continuous oxygen therapy (COT) is initiated, if initiated when
the patient is medically unstable. METHODS: A cross-sectional study was performed
to examine how often orders for COT are reevaluated pursuant to the guidelines
promulgated by the Third Oxygen Therapy Consensus Conference, and to assess the
impact that following these guidelines would have on the cost of COT. RESULTS: Of
226 patients prescribed home oxygen therapy, 92 had COPD as a primary diagnosis
and 57 were prescribed COT. Only 19 (35%) of 55 patients who returned to the
clinics were appropriately reevaluated. The rate of appropriate reevaluation was
significantly higher among pulmonary physicians than among primary care
physicians (65% vs 17%; odds ratio: 9.0; 95% confidence interval: 2.5-32). Of 19
patients who were appropriately reevaluated, 11 (58%) were discontinued from COT.
The patients who were discontinued from COT had a significantly higher percent of
predicted forced expiratory volume in the first second than those who were not
(34 +/- 8.6% vs 25 +/- 8.8%; p = 0.04). CONCLUSIONS: In our study, most patients
were clinically unstable when COT was prescribed, and a significant number of
patients remained on COT without reevaluation. Up to 60% of those patients could
potentially be discontinued from COT if appropriately reevaluated. Referring a
patient initiated on COT to a pulmonary specialist for the proper use of oxygen
is strongly recommended. Reevaluating such patients in a timely fashion and
discontinuing unnecessary oxygen concentrators could possibly save $106-153
million per year in the United States.
PMID- 10780036
TI - Spirometry in normal subjects in sitting, prone, and supine positions.
AB - OBJECTIVE: Determine whether pulmonary function testing is affected by patient
positioning. METHODS: In a descriptive study with measurements made in a
sequential but randomized order at a university-based pulmonary function
laboratory, 20 healthy men, ages 18-50 years, were evaluated with spirometric
assessment of forced vital capacity (FVC), forced expiratory volume in the first
second (FEV1), and maximum voluntary ventilation (MVV) in the sitting, supine,
and prone positions. Subjects were excluded for body mass index (BMI) > 30 kg/m2
or abnormal baseline spirometry. RESULTS: Comparing sitting to supine and prone
positions, there was a statistically significant decline in the spirometry values
(reported as percent of predicted normal +/- standard error of the mean). FVC was
102% +/- 4% while sitting, 95% +/- 4% while supine, and 94% +/- 4% while prone.
FEV1 was 104% +/- 3% while sitting, 96% +/- 3% while supine, and 94% +/- 3% while
prone. MVV was 115% +/- 4% while sitting, 102% +/- 4% while supine, and 97% +/-
3% prone. CONCLUSION: In healthy men with BMI < 30 kg/m2, changing from the
sitting to supine or prone position results in statistically significant change
in respiratory pattern. However, all spirometry values in each position were
normal by American Thoracic Society definitions.
PMID- 10780037
TI - Persistent left superior vena cava: case report and literature review.
AB - A persistent left superior vena cava (PLSVC) is the most common thoracic venous
anomaly. It is a persistent remnant of a vessel that is present as a counterpart
of normal right-sided superior vena cava (SVC) in early embryological development
but normally disappears later. Although it can be easily diagnosed by the
characteristic chest radiographic appearance of a pulmonary artery catheter (PAC)
passed through it after being inserted into the left subclavian or jugular vein,
its diagnosis is usually missed by the presence of normal (right) SVC and the
passage of the catheter on the right side. Its diagnosis can be confirmed by many
noninvasive and invasive tests, or it is incidentally diagnosed at thoracic
surgery or autopsy. If it is not associated with other congenital cardiac
anomalies, it is usually asymptomatic and hemodynamically insignificant. However,
PLSVC has important clinical implications in certain situations. In this article,
we describe a patient with bilateral SVC (a normal right SVC and a PLSVC)
identified by a PAC in the PLSVC and the pacemaker wires in the right SVC. In
addition, we review the literature on prevalence, embryological development,
diagnosis, and clinical implications of PLSVC.
PMID- 10780039
TI - Are digital distance learners learning or just distant?
PMID- 10780038
TI - 1999 Donald F Egan Scientific Lecture. Weaning from mechanical ventilation: what
have we learned?
PMID- 10780040
TI - Guidelines for nasal provocations with aspects on nasal patency, airflow, and
airflow resistance. International Committee on Objective Assessment of the Nasal
Airways, International Rhinologic Society.
AB - Under the auspices of the International Rhinologic Society (IRS) there is an
'International Committee on Objective Assessment of the Nasal Airways'. In 1984
Rhinology published the Committee's recommendations regarding rhinomanometry
(Clement, 1984). During the last Congresses of the European Rhinologic Society
(ERS) a subcommittee within that committee has discussed nasal provocations and
the value of measuring nasal patency, airflow and airflow resistance to evaluate
such provocations. The following is an effort to a consensus of indications and
techniques for nasal provocation and to a critical analysis of methods to measure
the effects. Only the most known methods will be discussed, i.e. acoustic
rhinometry, rhinostereometry, nasal peak airflow and rhinomanometry with its
different techniques. For graded responses after provocations the use of such
methods is of clinical value only in combination with scores from symptoms such
as sneezes and secretion, as allergic rhinitis symptoms consist of obstruction,
sneezing, itching and concomitant symptoms of the neighbouring organs. For
research all methods can be recommended to be used and their respective value is
depending on the specific scientific purposes.
PMID- 10780041
TI - The nasal valves: changes in anatomy and physiology in normal subjects.
AB - There is confusion in the literature concerning the physiology and pathology of
the nasal valve, and some debate as to whether there is one valve or two. In an
attempt to clarify these uncertainties we have measured nasal function by
assessing nasal minimum cross-sectional area, inspiratory resistance and peak
inspiratory flow under baseline conditions and after the application of a topical
vasoconstrictor. These measurements were then repeated following the application
of external and internal nasal splints. Whatever test was employed the results
showed that vasoconstriction tended to be the most potent stimulus which changed
nasal function producing significant expansion of the minimum cross-sectional
area, a decrease in inspiratory resistance and an increase in peak inspiratory
flow. External splints also increased the minimal cross sectional area but they
had no effect on inspiratory resistance or on the tendency of the vestibular rim
to collapse at high inspiratory flow rates. The tendency for lower lateral
cartilage collapse was, however, prevented by internal splintage using alar
dilators. The results of this study suggest that there is an internal valve at
the nasal isthmus where the principal alterations in airway patency follow
changes in mucosal congestion, and a mobile external valve where airflow is
limited by the tendency of the alar cartilages to collapse. These should be
considered as separate entities with differing pathophysiology and these
differences should be taken into account when treating patients with airway
obstruction due to pathology at these sites.
PMID- 10780042
TI - A new method for endoscopic evaluation in rhinology: videocapture.
AB - The aim of the study is to analyze a new method for the elaboration of endoscopic
images of the nasal cavity called "videocapture" and to compare the data from
this technique with the ones obtained with anterior active rhinomanometry.
Videocapture is based on a software program able to process endoscopic images, to
file them and to measure perimeter and area of the structures inside the images
recorded. We enrolled 27 patients with inferior turbinate hypertrophy and we
performed, before and after nasal decongestion test, anterior active
rhinomanometry, acoustic rhinometry, videocapture to compare the results obtained
with these different techniques. The results we got confirm in a statistically
significant way, the reliability of videocapture and its easy way of application.
PMID- 10780043
TI - Value of radiologic imaging and computer assisted surgery in surgical decisions
of the anterior skull base lesions.
AB - The role of radiologic imaging in surgical decision making of anterior skull base
lesions has been found to be critical in the endoscopic surgical management of
these lesions. The non-invasive radiologic imaging may include the use of CT
scans, MRI scans, MRA scans and their subtraction technique. The imaging offers
an understanding of the vascularity of the lesion, the relationship to the nearby
neurovascular structures and the type of tissue density of these lesions. The
addition of image guided applications offers one a sagittal reconstruction and a
3-D imaging capacity which has immensely improved the accuracy and precision in
endoscopic surgical applications in these areas.
PMID- 10780044
TI - Eosinophil count in nasal secretions of subjects with and without nasal symptoms.
AB - The aim of this paper, based on a cross-sectional study of 129 patients with
nonallergic chronic nasal symptoms and 40 healthy controls, was to examine the
leucocyte differential count in nasal secretions as a diagnostic test. Nasal
secretions were collected using preweighed suction glass canulas under controlled
conditions (-100Pa, 30 sec). Leucocyte and differential counts were performed
using a Thoma hemocytometer and on cytospin slides after May-Grunwald-Giemsa
staining. The percentage of eosinophils (Eo) was significantly higher in patients
(mean +/- SEM: 15.1 +/- 2.3%) than in controls (5 +/- 2.6%) (p < 0.04).
Comparison of the frequency distribution of the percentage of Eo in patients and
controls clearly showed a subgroup of patients presenting with nasal secretion
hypereosinophilia, and allowed us to set the positivity criterion at Eo = 20%.
Diurnal variations in Eo count in 11 controls and 8 patients confirmed the value
of the cutoff point. In 28 patients with nasal polyposis who underwent surgery, a
correlation was found between secretion and tissue eosinophelia (r = 0.58, p =
0.001). Patients with nasal secretion hypereosinophilia had no more leucocytes in
their secretions than healthy controls, the increase in eosinophils being
balanced by a decrease in neutrophils. In patients without hypereosinophilia, the
number of leucocytes per milligram of secretion was four times higher (8672 +/-
2521) than in the controls (2020 +/- 823) (p = 0.06) (cut-off point = 2500
leu/mg). These data show that the nasal cytogram can be modified either in
qualitative or quantitative way, probably depending on the underlying
inflammatory process.
PMID- 10780045
TI - The prevalence and significance of incidental paranasal sinus abnormalities on
MRI.
AB - Morphological changes in the paranasal sinuses are regularly noted on MRI, but
little is known about the incidence and significance of these changes in the
general population. The purpose of this study was 1) to classify the
morphological changes in the paranasal sinuses seen on MRI 2) to investigate the
prevalence, site and type of paranasal abnormalities and 3) to evaluate the
significance of the findings by relating them to the presence of sinusitis
symptoms, allergy, smoking habits and seasonal variations. In a one-year period,
404 patients referred to MRI for suspected intracranial neurological pathology
were prospectively investigated. Before undergoing the scan the patients
completed a questionnaire. The observed morphological conditions were classified
so that mucous thickening < 5 mm was recorded as normal; > or = 5 mm, total sinus
opacification or fluid and polyps as pathological. According to this
classification 31.7% of the patients had pathological findings in the sinuses. A
significantly higher incidence was found in the winter period and in patients
with symptoms associated to sinusitis. "Blocked nose" was the only symptom
occurring significantly more often in patients with pathological changes. There
was no significant relationship between paranasal sinus abnormalities and sex,
age, allergy, smoking habits, previous events of sinusitis or frequent events of
colds. Criteria for pathological MRI findings in the paranasal sinuses are
desirable and might improve the basis for a decision on the correct medical or
surgical treatment.
PMID- 10780046
TI - Congenital nasal pyriform aperture stenosis in newborn: report on three cases.
AB - Congenital nasal pyriform aperture stenosis (CNPAS) is recognized as a cause of
nasal airway obstruction in the newborn. The nasal pyriform aperture is narrowed
by a bony overgrowth of the nasal process of the maxilla. The CNPAS may occur as
an isolated congenital defect or in combination with other abnormalities. Three
cases of CNPAS are reported with special attention to the clinical presentation
and to the management recommendation prior to surgery. Surgical repair was
performed for all these three highly symptomatic patients using a sublabial
approach for drilling the nasal process in order to obtain a wider nasal
vestibular patency. All of them were equipped with bilateral nasal stenting.
PMID- 10780047
TI - Unilateral blindness in a child with acute sinusitis.
AB - Orbital infection in association with sinusitis is an emergency. It may cause
visual disturbances, and in rare cases even permanent blindness by affecting the
optic nerve. We report an unusual case of acute sinusitis that was complicated by
irreversible visual loss in a young patient. As there is increasing evidence that
respiratory viruses play an important role in the pathogenesis of acute community
acquired sinusitis and spontaneous healing with only symptomatic treatment is
common, the use of antibiotics in the treatment of acute sinusitis may not be
needed in all cases. If the general policy to use antibiotics in acute sinusitis
will be changed to more restrained and expectant, we have to be even more aware
of these nowadays rare complications.
PMID- 10780048
TI - Chondrosarcoma of the nasal septum.
AB - Chondrosarcoma of the nasal septum is a rather uncommon tumour. Therefore, only
limited numbers of cases have been described in the literature. This paper
reveals one more case observed at the ORL department of Dicle University. In the
present case, by using a transnasal and transpalatal approach, total resection of
the tumour was performed in conjunction with postoperative radiotherapy.
PMID- 10780049
TI - Short- and long-term effects of a 12-week intensive functional restoration
programme in individuals work-disabled by chronic spinal pain.
AB - The short- and long-term effects of a 12-week intensive functional restoration
programme for 153 participants with chronic spinal pain are reported. The average
patient sick leave before the programme started was about one year. At the 2-year
follow-up, 69% of the participants reported in telephone interviews that they
were working either part time or full time. Aerobic fitness, trunk muscle
strength and lifting capacity increased during the programme. In the non-working
groups, pain was rated higher and quality of life lower than in the working
groups at the 1- and 2-year follow-ups. For the women's return to job, the best
predictors were the time since the original pain onset and the achieved capacity
to lift from waist to shoulder level. For the men's return to job, the best
predictors were the initial work situation, the time since the original pain
onset, the oxygen uptake and the lumbar lifting capacity at the end of the
programme. The results of this non-controlled rehabilitation programme, both
short- and long-term, support earlier findings that intensive rehabilitation can
increase physical capacity and general well-being.
PMID- 10780050
TI - Professional phagocytes: predators and prey of microorganisms.
AB - Phagocytosis is an ancient cellular function. However, professional phagocytes
have evolved only in higher organisms, where they play an important role in host
defence. Professional phagocytes are capable of engulfing relatively large
microorganisms and killing them with a combination of various microbicidal
systems. Crucial killing mechanisms of phagocytes include superoxide generation
by phagocyte NADPH oxidase and release of microbicidal proteins through
exocytosis of performed granules. Phagocytes are also able to interfere with
microbial growth through alteration of the phagosomal ionic environment
(acidification, iron depletion). While the microbicidal mechanisms of phagocytes
are extremely efficient and capable of killing most microorganisms, pathogenic
microorganisms have developed mechanisms to resist phagocytes. Microorganisms
capable of surviving within phagocytes are rare, but represent very successful
pathogens, such as Mycobacterium tuberculosis. Other pathogens, such as S.
aureus, have developed strategies to evade phagocytosis. How microorganisms are
phagocytosed and killed, and why certain pathogens resist these mechanisms, are
crucial questions for an understanding of the pathogenesis of infectious diseases
and the development of innovative treatment approaches.
PMID- 10780051
TI - Antiviral therapy: current options and challenges.
AB - This article reviews current options and concepts for drug treatment of viral
infections with the exception of human immunodeficiency virus infection. Advances
in antiviral drug development and in rapid diagnostic methods have resulted in
efficient management strategies, particularly for infections due to herpes
simplex virus, varicella-zoster virus, cytomegalovirus, influenza A and B
viruses, and chronic hepatitis B and C. Newer antiviral agents, such as
valaciclovir and famciclovir, have a high oral bioavailability which permits less
frequent intake and avoidance of intravenous therapy in many cases. As an
alternative to subcutaneous interferon-alpha (IFN-alpha) treatment, oral
lamivudine is now approved for therapy of chronic hepatitis B. The addition of
oral ribavirin to IFN-alpha treatment has been shown to be superior to IFN-alpha
alone for therapy of chronic hepatitis C. By contrast to amantadine,
neuraminidase inhibitors such as zanamivir or oseltamivir (GS4104) have activity
against both influenza A and B viruses and are well tolerated. First results of
controlled trials with these agents are discussed. The emergence of herpes virus
resistance to antiviral drugs is of concern, and validation of alternative
treatment for patients with documented resistance is required. Future
investigations may also help to clarify the therapeutic role of novel antiviral
drugs and formulations, such as the oral prodrug of cidofovir, valganciclovir,
compounds 1263W94 and Bay 38-4766, and pleconaril.
PMID- 10780052
TI - News in autoimmune disease.
AB - The diversity of strategies reflects as much the lack of ideal treatments as it
does the imagination of the investigators. Many aspects such as manipulation of
apoptosis and extracorporeal removal of autoantibodies have been omitted due to
space restrictions. Although most successful treatment strategies have been based
on proven basic research principles, most require well performed, prospective,
randomised clinical trials before optimistic anecdotes translate to clinical
practice. We must not forget the aim of improving quality of life for our
patients, and not just improvement of immunological laboratory parameters.
PMID- 10780053
TI - Does infection control control infections?
AB - Compelling data exist for the return on investment of infection control
activities. Such information is important in the era of managed care where cost
containment and accountability are mandated.
PMID- 10780054
TI - [The hospitalized patient with fever and mental status changes].
AB - The case is discussed of a 74-year-old patient hospitalised with acute colitis,
who newly developed headache, fever, and mental status changes on the 14th day
after admission. The course of the disease was characterised by rapid progression
with loss of consciousness and the development of extensive brain oedema, despite
broad-spectrum antibiotic therapy. The patient died on the 17th of
hospitalisation.
PMID- 10780055
TI - [Pruritus with unusual cutaneous lesions].
PMID- 10780056
TI - [Single and double high-dose chemotherapy with autologous stem cell
transplantation in children with advanced solid tumors: first experiences].
AB - The disease-free survival of children with malignant disorders has increased
impressively over the last three decades due to better understanding of tumour
biology and the resultant improvement in diagnosis and therapy. Children with
advanced and relapsed solid tumours, such as brain tumour, alveolar
rhabdomyosarcoma, Ewing's sarcoma, or neuroblastoma, have not benefited from this
progress. The concept of myeloablative high-dose chemotherapy (HDT) is based on
the observation that certain cytostatic drugs have a steep linear dose-response
curve, and thus escalating the dose may increase the tumour cell kill. The
interest in HDT intensified when autologous stem cells mobilised from the
peripheral blood became available, in view of the possibility of increasing the
cell dose, which correlates directly with the time period of haematopoietic
recovery and thus reduces therapy-associated toxicity. The aim of the study was
to evaluate the feasibility of single or double HDT by autologous peripheral
blood stem cell transplantation (PBSCT) after each cycle in children, and to
obtain pilot data for future prospective clinical trials. 11 children aged
between 2.8 and 17.2 years with brain tumours, soft tissue sarcomas, germ-cell
tumours and neuroblastomas were analysed over a 2-year-period. 7 of the 11
children are in complete remission 2+ and 24+ months after HDT, 3 died of
progressive disease and one child died of therapy-associated complications. The
median hospital stay was 29.5 (22-104) days. An absolute neutrophil granulocyte
count of 0.5 x 10(9)/l was achieved after a median stay of 11 days and a platelet
count of > 20 x 10(9)/l independent of platelet transfusions was achieved after
11 days. Painful stomatitis leading to total parenteral nutrition (9 children)
and intravenous morphine therapy (6 children) was the most serious toxicity.
Single or double HDT with autologous PBSCT after each cycle is feasible in
children and offers basic data for conducting phase III paediatric clinical
studies.
PMID- 10780057
TI - [Quality of dispensation of prescription medication from the patients' point of
view].
AB - A cross-sectional survey investigated quality relevant aspects of the most common
distribution channels (pharmacies, self-dispensing physicians) for prescription
drugs in Switzerland. A self-administered questionnaire focusing on consumers'
behaviour, perception and priorities regarding the process of dispensation of
prescriptive medication was mailed to a random sample of 3000 patients, aged 18
years or older, with regular intake of prescriptive medication. Chi-square
analysis was performed on 1058 responses. 60% of the respondents received their
medication mainly or exclusively from pharmacies and 40% from self-dispensing
physicians. In German-speaking Switzerland 53% of participants received their
prescription drugs exclusively or mainly from self-dispensing physicians,
compared to only 10% in the French-speaking area (p = 0.00). This distribution
confirms the existing differences in regulation of self-dispensation in these
regions. Most of the patients took 2-4 prescriptive drugs a day. The French Swiss
received slightly more prescriptive medication than the German Swiss (p = 0.05).
45% of the participants, especially women and people using a pharmacy, reported
additional, usually occasional over-the-counter medication. Provision of
technical information (41%), friendliness (19%), and the availability of drugs
(19%) were valued most important when receiving prescription drugs and 96% of the
participants were satisfied with the service. In consequence, the participants
were strongly bound to their source of drug supply. Some 80% received
instructions for use there. However, only half were informed about the purpose of
the medication, drugs' side effects, or possible drug interactions. Physicians
provided such information more often than pharmacy staff. This observation may be
attributable to the double role played by the self-dispensers, who provide
medical care and at the same time hand out the drug. In conclusion, patients'
satisfaction is achieved equally by both medication channels. However, there is a
need to improve counselling to ensure excellence in the supply of drugs.
PMID- 10780058
TI - [Mechanisms of neuroinvasion by prions: molecular principles and present state of
research].
AB - The prion was defined by Stanley Prusiner as the infectious agent that causes
transmissible spongiform encephalopathies and equated with the prion protein
PrPSc. Its cognate gene, Prnp, was identified by Charles Weissmann in Zurich, and
shown to encode the host protein PrPC. Since the latter discovery, transgenic
mice have contributed many important insights to the field of prion biology,
including an understanding of the molecular basis of the species barrier for
prions. By disrupting the Prnp gene, it was shown that an organism that lacks
PrPC is resistant to infection by prions. Introduction of mutant PrP genes into
PrP-deficient mice was used to investigate the structure-activity relationship of
the PrP gene with regard to scrapie susceptibility. Ectopic expression of PrP in
Prnp-knockout mice provided a useful strategy for the identification of host
cells competent for prion replication. Finally, the availability of Prnp-knockout
mice and transgenic mice overexpressing PrP allows selective reconstitution
experiments aimed at expressing PrP in neurografts or in specific populations of
hemato- and lymphopoietic cells. The latter studies have allowed us to clarify
some of the mechanisms of prion spread and disease pathogenesis.
PMID- 10780059
TI - [Allergy to house dust mites].
AB - The prevalence of atopic disease in Switzerland is 15-20%. About 30% of these
patients have perennial symptoms and a substantial proportion are allergic to
house-dust mite proteins. If absolute air humidity is lower than 7.0 g water per
kg air, house-dust mites will not proliferate. This is why the occurrence of
house-dust mites varies between different regions. About half of the patients
with allergy to house-dust mites complain of rhinitis, a quarter of asthma and a
quarter of asthma and rhinitis. The diagnosis is usually by history, skin prick
tests and if necessary provocation. Therapy includes allergen avoidance
(reduction of air humidity in dwellings by ventilation, encasing of mattresses
and bedding), medication (mainly topical corticosteroids) and specific
immunotherapy.
PMID- 10780060
TI - [Abdominal tumor].
PMID- 10780061
TI - [Value of positron emission tomography with 18-fluorodeoxyglucose (FDG-PET) in
early detection of residual tumor in oro-pharyngeal-laryngeal carcinoma].
AB - OBJECTIVE: To evaluate and compare the performances of FDG-PET imaging, MRI and
clinical examination in the detection of residual tumour 3 months after treatment
of patients with head and neck squamous cell carcinoma. PATIENTS: A consecutive
sample of 50 patients with squamous cell carcinoma of the oral cavity,
oropharynx, hypopharynx or larynx, or a cervical lymph node metastasis from an
unknown primary site excluding T1 lip and T1 vocal cord tumours. METHODS:
Treatment outcome was assessed after 3 months by clinical examination, MRI, and
FDG-PET scan. Sensitivity, specificity and accuracy were calculated relative to
proven biopsy of residual tumour or a clinical follow-up of 4 months. RESULTS:
Residual cancer was confirmed in 8 patients (16%), while the clinical follow-up
was unsuspicious in the remaining 42 patients. PET-FDG had a sensitivity of 100%
as compared to MRI (88%) and clinical examination (63%). Specificity was higher
for clinical examination (90%), intermediate for MRI (83%) and lowest for PET-FDG
(74%). CONCLUSIONS: This study finds very high sensitivity for PET-FDG in the
detection of residual tumour. However, its lower specificity, lack of anatomical
resolution, and high cost, require further studies to determine its role in
routine screening.
PMID- 10780062
TI - [Follow-up after histologically verified radical resection of early cancers of
the mouth cavity: results of a prospective multicenter study].
AB - INTRODUCTION: Early stage oral cavity carcinoma is curable in most cases. This
study follows the course of early stage squamous cell carcinoma of the oral
cavity after radical surgical resection, in order to assess the necessity of
further treatment modalities. MATERIAL AND METHODS: In a prospective multicentric
study, 110 patients with T1-T2 and N0-N1 (without capsular invasion) squamous
cell carcinoma of the oral cavity were enrolled. All patients were treated
exclusively by surgical resection with histopathologically proven negative
margins. RESULTS: Among 96 patients (14 excluded because of positive margins),
followed-up for 3 years, 18 presented a local or regional recurrence. In 12 of
these 18 loco-regional control was reestablished by second treatment. Overall,
the 4-year disease-specific survival probability was 94%. Patients treated
initially by selective neck dissection had significantly lower recurrence rates
than those without neck surgery. CONCLUSION: Early (T1-2, N0-1) squamous cell
carcinoma of the oral cavity is adequately treated by surgery alone. The surgical
procedure should include margin-free resection of the primary combined with
selective neck dissection. Systematic postoperative radiotherapy does not appear
necessary. Neck dissection is advocated in N0 patients as well.
PMID- 10780063
TI - [Value of panendoscopy in assessment of mouth cavity, pharyngeal and laryngeal
cancers].
AB - The concept of multiple squamous cell carcinoma in the region of the upper
aerodigestive tract was first described over 100 years ago by Billroth. The aim
of our study was to assess the incidence of synchronous and metachronous second
primary tumours and refine the role of panendoscopy in diagnosing them. The
charts of 358 patients presenting for initial treatment of primary squamous cell
carcinoma of the upper aerodigestive tract between January 1990 and December 1995
were reviewed. The incidence of second primary tumours was 16.2%, 6.4% being
synchronous and 9.8% metachronous. In only 3.1% of all patients was a synchronous
tumour clinically silent and only revealed by panendoscopy. Synchronous tumours
were most likely to be located in the oral cavity, pharynx or larynx (61%),
whereas metachronous second primary tumours were most likely to be located in the
lung (57%). Though the incidence of synchronous second primary tumours revealed
by routine panendoscopy is low (3%), we still recommend this investigation
because it is often necessary for exact assessment of the first primary tumour.
Further, it is ideal for training in the use of rigid endoscopy. In our opinion
panendoscopy involves minimal time, cost and morbidity.
PMID- 10780064
TI - [Treatment of laryngeal cancer: cordectomy or crico-hyoido-epiglottopexy versus
radiotherapy].
AB - INTRODUCTION: Both radiotherapy and endoscopic or open functional surgery are
recognised treatments for laryngeal cancer stage I and II. A comparison between
two groups of patients treated with either modality may clarify the indications
for both treatments. METHODS: Over a period of 13 years two separate series of
patients were treated for laryngeal cancer (stage I and II) by either surgery (n
= 72) or radiotherapy (n = 81). We have analysed and compared the two groups.
RESULTS: Statistical analyses show a better local control among patients treated
with surgery, when the anterior commissure was involved (p < 0.01) or with
extension of the tumour (T2). However, long-term survivals were not significantly
different in the two groups. As postradiation recurrence was diagnosed at an
early stage, salvage (requiring total laryngectomy in many cases) was efficient
but contributed to an appreciable difference in the long-term laryngeal
preservation rate between the two groups (91% after radiotherapy and 99% after
surgery). CONCLUSION: The treatment of laryngeal cancer must always compromise
between oncological efficiency and functional preservation. With anterior
commissure involvement (T1b) or more extensive disease (T2), surgery appears to
be better. Therefore, preservation of perfect laryngeal function should be
subordinate to oncological safety.
PMID- 10780065
TI - [When is laryngectomy indicated in hypopharyngeal carcinoma?].
AB - INTRODUCTION: We studied the histories of 121 patients with hypopharyngeal
carcinoma treated at our clinic from 1990-1998. From 1990-1993 all patients with
curable hypopharyngeal carcinoma were treated by surgery. Radiotherapy was used
for those in whom surgery was impossible or who refused laryngectomy. In 1994 we
changed our therapy and only patients in whom the voice could be preserved were
treated surgically. All others received radiotherapy as primary treatment. The
goal of this study was to ascertain whether and how this shift in therapy was
influenced by T and N stage. METHODS: From 1990-1993, 57 patients with
hypopharyngeal carcinoma were registered at our clinic. Surgery was performed in
32, 16 received radiotherapy and 9 only palliative treatment. During this time
there was no difference in diseased specific survival between the radiotherapy
and surgical groups. Therapy was therefore changed in 1994 to preserve voice
function. From 1994-1998, 64 patients were diagnosed. Only 10 were treated
surgically. 40 received radiotherapy and 14 no curative therapy. Age, N and T
stage were comparable in both groups. To show differences we performed Kaplan
Meier survival rates for both groups and for the N and T stage of patients
undergoing surgery or radiotherapy respectively. RESULTS: 3-year survival was 68%
in patients treated from 1990-1993 and 38% from 1994-1998. The difference was
statistically significant (p-value 0.02). Survival for nodal stages 0 and 1 was
much better in patients undergoing surgery than those receiving radiotherapy.
Multivariant analysis was highly significant. T-category showed no tendency for
either treatment modality. DISCUSSION: After a switch in the treatment of
hypopharyngeal carcinoma in 1994 there was a significant change in survival. For
patients with nodal stage 0 and 1 surgery brought much better survival. We
conclude that surgery should be the primary treatment for all patients in these
small nodal stages, even if total laryngectomy is necessary.
PMID- 10780066
TI - [Salvage surgery in laryngeal and hypopharyngeal carcinoma].
AB - INTRODUCTION: The aim of this study was to analyse survival and complications in
patients undergoing surgery for squamous cell carcinoma of the larynx and
hypopharynx as a salvage procedure for recurrent tumours after radiotherapy.
METHODS: Between January 1990 and December 1998, 166 patients with previously
untreated squamous cell carcinoma of the larynx and hypopharynx were primarily
treated by radiotherapy. Local failure occurred in 77 patients (46%). 57 (34%)
underwent salvage surgery. RESULTS: 5-year survival for the 42 patients with
carcinoma of the larynx was 60% and for the 15 patients with carcinoma of the
hypopharynx 20%. The overall rate of postsurgical complications was 33% in
patients with laryngeal and 47% in patients with hypopharyngeal cancer.
DISCUSSION: There are few data in the literature regarding the clinical outcome
in patients whose tumours are not controlled by initial radiotherapy. Our results
indicate that only in carefully selected cases is salvage surgery successful in
treating radiation failure in hypopharyngeal cancer. In patients with carcinoma
of the larynx salvage surgery is successful and the rate of postoperative
complications acceptable.
PMID- 10780067
TI - [Quality of life after treatment of laryngeal carcinoma: surgery versus
radiotherapy].
AB - Radiotherapy and surgery for laryngeal cancer achieve comparable results in
patient survival. Therefore, the expected quality of life is increasingly
influencing the choice of treatment. The aim of this study was to compare the
quality of life of patients after surgery or radiotherapy for laryngeal
carcinoma. To evaluate quality of life, we used the validated European
Organization for Research and Treatment of Cancer Quality of Life Questionnaire
Core 30 (EORTC QLQ-C30) and the EORTC Head and Neck module (EORTC QLQ-H&N35). 65
patients who were treated with either radiotherapy or surgery for laryngeal
cancer between January 1990 and December 1995, and who were alive and free of
tumour in January 1999, were included in this study. In the first group with
small tumours (T1/T2), 40 patients were treated by CO2-laser surgery and 16 by
primary radiotherapy. In the second group with more advanced tumours (T3/T4), 5
patients underwent total laryngectomy and 4 primary radiotherapy. In the first
group there was good global quality of life with no significant difference
between the two treatment modalities. Surgically treated patients scored
significantly better than the irradiated patients in questions about swallowing
of solid food, xerostomia and dental problems. No other significant differences
were found: hoarseness in particular was rated equally after both treatments. In
the second group there was also good global quality of life with no significant
difference between the two treatment modalities. The laryngectomized patients
scored equally on questions about voice function, talking on the phone and social
behaviour. As far as quality of life is concerned we can recommend both treatment
modalities for patients with laryngeal cancer of all stages.
PMID- 10780068
TI - [Skin and mucous membrane reactions during and after radiotherapy].
AB - The temporary acute reactions during radiotherapy are a burden for the patient.
These reactions are due to a depletion of stem cells and depend on the single
dose, the total dose and the irradiated volume. The WHO describes the acute
changes in a graded scale from 0 to IV. A knowledge of the course of these events
helps the otolaryngologist to inform patients competently, calm their fears and
give support during treatment. Efficacious measures to alleviate symptoms are
presented.
PMID- 10780069
TI - [Reconstruction of the anterior mouth floor by surgical flap microanastomosis:
oncologic and functional results].
AB - INTRODUCTION: The purpose of this retrospective study was to evaluate oncological
and functional results after reconstruction of the anterior floor of the mouth
using free flaps. METHODS: From 1992 to 1998, 30 patients with squamous cell
carcinoma of the anterior floor of the mouth underwent surgical excision and
primary reconstruction with either free forearm- or bone-composed flaps.
Functional assessment included evaluation by the Karnofsky scale, Performance
Status Scale for Head and Neck Cancer (PSS-HNC), articulation test and
videofluoroscopic examination. RESULTS: 16 patients underwent reconstruction with
a free forearm flap, 13 with an iliac crest flap and 1 with a fibula flap. The
most serious local complication was partial flap necrosis in two cases. Local
control was 90% at 24 months and the specific survival rate was 92% at five
years. Functional evaluation was performed on 19 patients: PSS-HNC median score
for diet was 70 (range 50-100), the score for speech was 70 (range 50-100) and
the score for "eating in public" was 65 (range 25-100). Patients with a major
mobile tongue resection had a lower score compared to patients with minor or no
mobile tongue resection. Videofluoroscopy showed swallowing alterations following
large resections of soft tissues. DISCUSSION: Our study confirms that wide
resection of mobile tongue is associated decreased rehabilitation quality.
Mandibulectomy does not influence rehabilitation.
PMID- 10780070
TI - [Impact of diagnosis and treatment of early stage secondary tumors on outcome for
the oncologic ORL patient].
AB - OBJECTIVE: To study the incidence, location and stage of second primary tumours
in patients with head and neck cancer and analyse the survival and outcome of
patients with early-stage second primary tumours. METHODS: Retrospective chart
review of patients treated for head and neck cancer from 1989 to 1993. Survival
analyses and statistical comparisons with the Kaplan-Meier method and log-rank
test. RESULTS: 99 of the 311 patients had second primary tumours. 45 patients had
synchronous second primary tumours and 54 metachronous second primary tumours,
diagnosed at an early stage (stage 0 or I) in 78 and 63% of cases respectively.
Patients with second primary tumours had a significantly (p = 0.03) lower
survival rate than patients with single tumour. However, for patients with early
stage second primary tumours survival was not significantly decreased (p = 0.3).
DISCUSSION: This study confirms the high incidence of second primary tumours and
their negative impact on the outcome of patients with head and neck cancer. Early
diagnosis and treatment of second primary tumours results in a survival rate very
similar to that of patients with a single head and neck cancer. This provides
indirect evidence that in patients with curable initial head and neck cancer
intensive screening for second primary tumours may result in an improved overall
outcome.
PMID- 10780071
TI - [Value of fine needle aspiration biopsy in diagnosis of cervical masses].
AB - Fine needle aspiration is a widely used diagnostic tool. Its use for the
evaluation of head and neck masses remains somewhat controversial. This
retrospective study analyses all patients presenting with neck masses
investigated by fine needle aspiration in our institution from January 1997 to
December 1998. 372 fine needle aspirations were performed. Cytological diagnosis
was possible in 91%. Sensitivity was found to be 100%, specificity 99% and
accuracy 99.7%. When including indeterminants in the false-negatives, overall
sensitivity is 73%, overall specificity 100% and overall accuracy 90%. There were
no complications, and in particular no suprainfection and no tumoural spread at
the puncture site. We conclude that fine needle aspiration is a sensitive and
specific modality which is very helpful in the diagnostic work-up of a neck mass.
PMID- 10780072
TI - [Hypothyroidism after combined surgical and radiotherapy treatment of cancer of
the ORL area].
AB - INTRODUCTION: Hypothyroidism is a well described complication of head and neck
cancer treatment, but routine testing of thyroid function is generally not done.
The combination of surgery and radiotherapy seems to increase the risk of thyroid
hypofunction. METHODS: Thyroid function was measured in 82 patients treated for
head and neck cancer (different types of surgical resection combined with pre- or
postoperative radiotherapy). The treatment was undertaken 1 to 220 months before
measurement of THS and T4. RESULTS: 43 out of the 82 patients (52%) had abnormal
thyroid tests. Hormonal replacement was necessary in 20/43 cases (24%). More than
85% of patients treated by total laryngectomy or pharyngo-laryngectomy,
associated with hemithyroidectomy or not, had hypothyroidism and replacement
therapy was necessary in more than half of these patients. For the other types of
surgery the incidence of hypothyroidism was 32% with 10% of patients needing
substitution. DISCUSSION: A high percentage of patients treated by surgery and
radiotherapy develop hypothyroidism. In our experience, routine thyroid function
testing is necessary in this group.
PMID- 10780073
TI - [Thyroid surgery: traps and preventing complications].
AB - A retrospective analysis was conducted of all thyroid operations performed at the
ENT department in St. Gallen, Switzerland, between 1995 and 1997. The
complications and technique of this surgery are outlined. In 79 patients 111
thyroid lobe resections were performed. No injury occurred to the superior
laryngeal nerve. One recurrent laryngeal nerve injury and one permanent
hypocalcaemia were observed. No revision operations were required for haematoma
or infection. The different steps in the operative procedure, such as skin
incision, handling of the strap muscles and identification of the parathyroid
gland and superior laryngeal nerve, as well as the monitoring of the recurrent
laryngeal nerve, are discussed.
PMID- 10780074
TI - [Cervicofacial necrotizing fasciitis].
AB - INTRODUCTION: Necrotising fasciitis is still a severe disease whose outcome is
occasionally fatal. METHODS: Between August 1994 and August 1998, 6 patients with
necrotising fasciitis, 5 in the neck area and one in the facial area, were
treated. The source of the infection was odontogenic in 3 cases, pharyngeal in 2
and an insect sting in the left upper eyelid in one case. RESULTS: Following
evaluation by CT scan, immediate surgical exploration with debridement and
drainage was performed. Revision proved necessary in most cases. One patient
suffered severe complications. Median stay in the intensive care unit was 7 days
and in hospital 20 days. DISCUSSION: Deep and extensive neck infections require
investigation by CT scan. All affected areas must be explored and drained
immediately, including thoracotomy if mediastinitis is present. Apart from
appropriate antibiotic therapy, the further course of the disease should be
carefully monitored to detect further spread of the infection as well as
complications.
PMID- 10780075
TI - [Surgical therapy concept in primary hyperparathyroidism].
AB - INTRODUCTION: Primary hyperparathyroidism is a relatively rare disease caused in
80-85% of cases by solitary adenoma of the parathyroid glands. The laboratory
findings are hypersecretion of PTH and hypercalcaemia. We distinguish between
asymptomatic and symptomatic primary hyperparathyroidism. 25 patients of our
clinic who underwent surgery in 1996 and 1997 are presented to illustrate our
surgical concept of therapy. METHODS: 7 patients were asymptomatic and 18
symptomatic with regard to primary hyperparathyroidism. Preoperative localisation
was facilitated by ultrasonography of the neck, which was used in all cases.
Bilateral exploration of the neck under general anaesthesia similarly to
thyroidectomy was the gold standard. Monitoring the inferior laryngeal nerve
helped to protect it. In 6 cases intraoperative parathyroid hormone monitoring
(rapid PTH assay) was applied. RESULTS: More than a third of the symptomatic
group of patients had neurological or psychiatric diseases, followed by symptoms
of the musculoskeletal and urological systems. Possible reasons for surgical
intervention were persistent hypercalcaemia, age over 50, radiological findings
of kidney stones or decreased kidney function. In 17 patients the preoperative
ultrasonographic localisation was consistent with the intraoperative clinical
findings. The sensitivity of this method was 68%. Intraoperative pathology showed
17 patients with a solitary adenoma, 4 ectopic, 2 cases had double adenoma, and 2
others hyperplasia with enlargement of all glands. After resection of the
pathological parathyroid glands there was a decrease of parathyroid hormone in
intraoperative hormone monitoring of approximately 60%. The preoperative
hypercalcaemia (mean 2.99 mmol/l) usually normalised 4 hours postoperatively.
There was no severe intraoperative bleeding and the inferior laryngeal nerve was
preserved in all cases. All patients were monitored at 3-month intervals for
parathyroid hormone and serum calcium during the first year after operation. One
patient had persistently elevated parathyroid hormone without clinical findings.
DISCUSSION: Parathyroidectomy is an efficient and safe operation with excellent
normalisation of serum calcium and parathyroid hormone and a high rate of patient
satisfaction. In this study assessment of ultrasonography was the preferred
method of locating enlarged parathyroid glands before operation. However, this
method is not based on unilateral exploration of the glands. Therefore, we prefer
to locate all four glands, an approach based on the literature [1, 2].
Intraoperative monitoring of parathyroid hormone facilitates assessment of the
operative result [3]. Normalisation of calcium in serum and the effectiveness and
safety of the surgical method are confirmed in other publications [4-8]. In 24 of
our patients normocalcaemia resulted within 12 hours after operation and in one
patient within 4 days. One year after operation and endocrinological checkup all
25 patients were asymptomatic and normocalcaemic, while one patient had
persistently high parathyroid hormone of unknown origin.
PMID- 10780076
TI - [Incidental ultrasound detection of thyroid nodule: what next?].
AB - INTRODUCTION: The routine use of ultrasonography in ENT to investigate the
lymphatic system of the neck leads to a number of incidentally found thyroid
nodules. METHODS: After reevaluating our patients from 7/95 to 12/98 we searched
the relevant literature for a reasonable diagnostic pathway for these findings.
RESULTS: 67 patients had one or more incidentally found thyroid nodules. 23 were
followed sonographically. 8 patients had fine needle biopsy as a first diagnostic
step. One nodule was cytologically suspect for papillary carcinoma, which was
confirmed later histologically after resection. DISCUSSION: Autopsy studies
showed a 5% malignancy rate in the occult thyroid nodules. Most of these occult
growths are papillary carcinomas with a relatively good prognosis, especially
when they measure less than one centimeter. We recommend performing a fine needle
biopsy in any patient with a thyroid nodule > 1 cm, with a history of prior
irradiation of the neck or with medullary carcinoma in the family. Clinical and
sonographic follow-up should be done after 6 to 12 months in the rest of the
cases.
PMID- 10780077
TI - [Liposarcoma in the area of the head-neck].
AB - Liposarcoma is the second most common soft tissue sarcoma occurring in adults,
though it rarely involves the head and neck region. Fewer than 100 such cases
have been described in the literature. We present two additional cases and a
review of the literature. Prognosis is mainly determined by histologic grade. A
high incidence of local recurrence is typical of all subtypes. Complete surgical
excision is the most effective treatment. In the head and neck region the extent
of the excision is limited by the proximity of neurovascular structures. The
benefits of adjuvant radiotherapy in head and neck liposarcoma remain uncertain.
Studies on liposarcoma at other sites indicate that addition of radiotherapy to
surgery may result in longer local recurrence-free survival, though without
improvement of overall survival.
PMID- 10780078
TI - [Endonasal dacryocystorhinostomy: technique and results].
AB - BACKGROUND: Endonasal dacryocystorhinostomy has recently become an important
alternative to the classical external Toti procedure. OBJECTIVE: To analyse the
outcome after endonasal dacryocystorhinostomy. METHODS: For this purpose 28 of 34
patients treated by endonasal dacryocystorhinostomy between May 1994 and November
1998 were investigated. RESULTS: After an average follow-up of 28 months, 23 of
the 28 patients (82%) are free of symptoms. Two additional patients became
symptom-free after revision surgery. The total success rate is 89%. The only
complications seen were 2 cases of asymptomatic synechiae and one case of mild
hyposmia. CONCLUSIONS: Endonasal dacryocystorhinostomy is a rapid, safe, and
elegant method for the treatment of post-saccal nasolacrimal duct obstructions.
PMID- 10780079
TI - [Results of voice rehabilitation with Provox prostheses].
AB - From 1992 to 1998, 105 patients of the Department of Otorhinolaryngology, Head
and Neck Surgery in Berne underwent laryngectomy with primary implantation of a
Provox prosthesis. These patients were followed up in an open prospective study
and evaluated by the HRS scale, based on speaking ability and quality as well as
on prosthesis care. 46 patients (44%) attained successful rehabilitation of the
voice, defined as 12-15 points according to the HRS scale. Age, tumour stage and
postoperative irradiation did not influence the results. Compared to the patient
group with less than 12 HRS points, frequent replacements or short in situ
lifetime of the prosthesis improve the results of rehabilitation. Patient
compliance is an important factor in achieving success with the Provox
prosthesis.
PMID- 10780080
TI - [Infectious mononucleosis: when is tonsillectomy indicated?].
AB - INTRODUCTION: Infectious mononucleosis is usually a benign, self-limited disorder
of the lymphopoietic system. Tonsillopharyngitis is a common presentation of the
disease. Occasionally upper airway obstruction or a prolonged swallowing disorder
require surgical intervention. METHODS: We conducted a retrospective analysis of
all infectious mononucleosis cases seen at the ENT clinic in St. Gallen,
Switzerland, between 1994 and 1998. RESULTS: 21 records were analysed, among
which 19 patients needed hospital care. 11 cases required tonsillectomy. The
average duration of fever of the patients undergoing surgery was markedly lower
(9 days) than the conservatively managed cases (14.2). DISCUSSION: Tonsillectomy
is well tolerated, eliminates airway obstruction and rapidly improves swallowing.
PMID- 10780081
TI - [A new self-retaining titanium-gold stapes prosthesis].
AB - Various aspects of stapes surgery have been improved since its introduction in
1958 by Shea. However, fixation of the prosthesis on the long process of the
incus remains difficult. Furthermore, the functional result of crimping cannot be
predicted. Necrosis of the lenticular process still occurs. A new stapes
prosthesis has been developed with the Kurz Co. The use of titanium allowed an
innovative design: titanium has a shape memory, and a clip was constructed which
uses this memory for fixation on the incus. Two new instruments were also
developed to facilitate application of the prosthesis: a prosthesis inserter and
a prosthesis crimper. The clip does not strangulate the incus; it is attached
only to the superior and inferior surface of the incus, which are the crucial
locations for mechanical transmission of the piston-like movements of the
ossicular chain. Avoidance of circumferential attachment should reduce the risk
of incus necrosis. Once the clip is pushed onto the incus no further crimping is
necessary. The piston is of pure gold, as in this company's gold piston which has
been in use for many years. In future the prosthesis may be all-titanium.
PMID- 10780082
TI - [EBV infection as etiology of otomastoiditis with peripheral facial paralysis in
the child].
AB - Case report on a 15-month-old girl with acute bilateral otomastoiditis with
facial nerve palsy in the course of an EBV infection. Although the initial
mononucleosis blood test was negative the diagnosis was established by the
presence of blastic transformed lymphocytes with immunoreaction for the latent
membrane protein of EBV, and the presence of EBV-mRNA in the majority of
lymphocytes in the biopsy specimen. The occurrence of facial nerve palsy in the
course of an EBV infection is relatively rare but well known. The present case
involved a viral otomastoiditis with a typical course, which was complicated by
facial nerve palsy after a few days of illness. A case of this kind has only once
been described in an adult patient and has never been reported in a child.
PMID- 10780083
TI - [Otitis and sinusitis: research on associated pathology of the middle ear in the
adult].
AB - The author looked for associated pathologies in adult otitis media. In 31 cases
collected during 11 months of private practice as en ENT specialist he observed
radiological anomalies of the sinus cavities in 19 cases (61%), concomitant ENT
ailments in 9 (29%) and serious deterioration of general condition in 3 (10%). He
concludes that adult otitis media is not an isolated phenomenon and that its
management must take other associated pathologies into account.
PMID- 10780084
TI - [Evolution of sudden deafness without treatment].
AB - Spontaneous recovery of hearing following sudden deafness is evaluated. Between
1983 and 1997, 59 patients presenting with sudden hearing loss deliberately
declined treatment. Recovery is similar for low and high frequency hearing
losses, 40% of cases recovering hearing with an interaural threshold difference
below 20 dB. These results are similar to those of several studies using
different treatments. Therefore, sudden deafness need not be treated at all
costs.
PMID- 10780085
TI - [Stapes surgery in anomalies of the course of the facial nerve].
AB - In 548 stapes operations performed in Berne during the period 1994-1998, an
anomaly of the course of the facial nerve was observed in 37 cases. 29 exhibited
partial prolapse of the nerve over the oval window, with or without dehiscence of
the bony canal, while 5 showed total prolapse of the nerve over the oval window.
In one case the nerve was duplicated round the oval window and in a further
instance the facial nerve was situated over the promontory and also over the oval
window. In one other case the nerve was spread widely over the oval window.
Concomitant anomalies of the stapes were frequently observed. The following
surgical techniques were employed: in the case of partial prolapse of the nerve,
a small piston was placed in the lower part of or in the oval window, which was
widened towards the promontory. In cases of total prolapse of the facial nerve
the prosthesis was drilled straight into the promontory. Where the nerve was
duplicated the prosthesis was placed in the footplate between the nerve branches,
and where the nerve ran over the promontory and over the oval window the
prosthesis was placed above the oval window. In the case where the nerve was
spread widely over the oval window, no prosthesis was inserted. 78% of patients
had a residual air-bone gap of 20 dB or less; in only three cases did hearing
fail to improve. One patient with Crouzon disease involving a complex anomaly had
a hearing impairment of 22 dB. There was no deafness, facial paralysis or vertigo
with nystagmus.
PMID- 10780086
TI - [Normal and pathological facial mimicry: objective analysis].
AB - INTRODUCTION: Objective evaluation methods for facial nerve function are yet to
be standardised. Unresolved issues include what should be measured for different
facial movements and how these measurements should be performed. METHODS: 5
facial mimics were analysed in normal subjects and in patients with facial
paralysis. For each mimic the best measurement was determined and two global
indexes derived. RESULTS: The best measurements were of surfaces close to the
moving facial zone. These measurements and the global indexes correlated well
with gradings by the House-Brackmann scale.
PMID- 10780087
TI - [Correlation between objective criteria and subjective evaluation of symptoms in
chronic rhinosinusitis].
AB - INTRODUCTION: We evaluated the possible correlations between the extent of
inflammatory infiltration of the nasal mucosa caused by mechanical irritation
(septal deviation and hypertrophy of the middle turbinate) and nasal airway
resistance measured by rhinomanometry and acoustic rhinometry. Subjective
evaluation of the nasal obstruction, rhinorrhoea and headache was done by visual
analogic scale and compared with the inflammation. PATIENTS AND METHODS: 40
patients with a more than 18 months' history of chronic rhinosinusitis associated
with septal deviation and/or hypertrophy of the middle turbinate were included in
the study. The density of inflammatory cells (graded from + to +3, where + means
few and +3 abundant inflammatory cells) in the mucosa of the middle turbinate was
evaluated histopathologically. RESULTS: We found a significant correlation
between subjective intensity of nasal obstruction and inflammation (mainly
lymphocytes) of the middle turbinate mucosa and the value of nasal airway
resistance measured by rhinomanometry. No correlation was found between the other
parameters studied. CONCLUSION: Mechanical stimulation at the level of
turbinoseptal contact causes inflammation in the mucosa which correlates with
both subjective nasal airway resistance and rhinomanometry values.
PMID- 10780088
TI - [Atypical pneumatization of the paranasal sinus system].
AB - 200 CT scans of adult patients with paranasal sinus problems seen in the ENT
Department either in the University Hospital in Berne, Switzerland, or in the
University Hospital in Munich, Germany, were analysed. Among these we found 9
striking abnormalities of paranasal sinus anatomy. We found abnormalities which
caused clinical symptoms, such as an infected concha bullosa, a fine-septated
infected maxillary sinus, a pneumosinus dilatans of the frontal sinus with
aesthetic problems, and a cellula orbito-ethmoidalis with sinusitis. Some of
these abnormalities were found by coincidence, such as a cellula orbito
sphenoidalis and an extreme pneumatisation of the sinus sphenoidalis with a
pneumatised processus pterygoideus. 2 cases show the importance of preoperative
evaluation of a possible abnormal sinus to avoid operative complications: a sinus
sphenoidalis with a pneumatisated clivus and an intraluminal a. carotis interna.
The other case involved an optic nerve running free through the sphenoidal sinus.
In conclusion we stress the importance of preoperative CT examination and the
choice of a coronary or axial CT scan, which reveals any abnormal anatomy of the
paranasal sinus pneumatisation and thus increases the safety and efficiency of
paranasal sinus surgery.
PMID- 10780089
TI - [Significance of human papillomaviruses (HPV) in sinonasal papillomas].
AB - The present study comprises 43 patients with sinonasal papillomas operated on
between 1990 and 1997 at the ENT Department, University Hospital of Zurich.
Histology showed 5 cases of exophytic papilloma (EP) (12%), 34 cases of inverted
papilloma (IP) (79%) including 4 cases of associated carcinoma (9%), and 4 cases
of columnar cell papilloma (CCP) (9%). Recurrence developed in 6 of 41 patients
(2 EP, 4 IP) (15%). HPV was detected in 4 of 37 specimens (11%) both by in situ
hybridization (ISH) and polymerase chain reaction (PCR). HPV-11 was found in 3
lesions (2 EP, 1 IP), whereas HPV-6b was detected only in one lesion (1 EP).
Altogether 3 of 5 EP (60%), one of 29 IP (3%) and one of 6 recurrent papillomas
(1 EP) (17%) tested positive for HPV. Our findings suggest a possible role for
HPV in the pathogenesis of exophytic papilloma. As no correlation was found with
associated malignancy and recurrence of disease, screening for HPV seems not to
be useful as a prognostic parameter.
PMID- 10780090
TI - [Partial inferior turbinectomy with security (T.I.P.S.) in chronic nasal
obstruction: personal surgical technique and outcome].
AB - Partial inferior turbinectomy with security (PITS) was performed in 224 patients.
In 206 cases (92%) surgery was bilateral and 76 patients (34%) had no other
associated intervention. The follow-up period ranged in the whole group from 12
to 64 months (mean 31 months). In the group of 76 patients the follow-up period
ranged from 12 to 55 months (mean 28 months). The nasal obstruction was
significantly reduced in 204 cases (91% of all patients operated on). The group
of 76 cases including 9 children underwent isolated bilateral turbinectomy with
90% successful results. The principal interest of this publication is a detailed
description of this new personal technique for a safe, rapid, non-haemorrhagic
and inexpensive method which can be easily performed even in children and also in
one-day surgery.
PMID- 10780091
TI - [Predictive value of nocturnal pulse oximetry in sleep apnea screening].
AB - The monitoring of overnight oxygen saturation is widely used for sleep apnoea
screening. The point of this screening has been questioned as a wide range of
sensitivity has been reported in the literature. In a prospective study 70
subjects presenting with a possible sleep apnoea-hypopnoea syndrome had overnight
oximetry followed by polysomnography 2 to 4 months later. Compared to
polysomnography, the sensitivity of oximetry for sleep apnoea-hypopnoea was
85.2%, the specificity 77.8% and the predictive value positive 96.3%. When short,
non-significant, repetitive desaturations have been declared pathologic,
sensitivity increased to 91.8%. In the hands of an expert user, oximetry
represents an excellent instrument for detecting patients with sleep apnoea
hypopnoea. Patients with pathological nocturnal oximetry are candidates for nCPAP
treatment and therefore should undergo a sleep laboratory investigation.
PMID- 10780092
TI - [Madelung disease and obstructive sleep apnea syndrome: apropos of a case].
AB - Madelung's disease, or benign symmetric lipomatosis, is an uncommon disease. It
is an unencapsulated fatty infiltration which in rare cases extends into the
perilaryngeal space and mediastinum. The authors present a case complicated by an
obstructive syndrome and sleep apnoea syndrome, which was successfully treated by
continuous positive airway pressure. The literature is reviewed.
PMID- 10780093
TI - The Mediterranean diet and endothelial function: why some dietary fats may be
healthy.
AB - Evidence from both diet and physiologic studies suggests that some dietary fats-
but not others--impair endothelial function in the short term, possibly by a
mechanism of oxidative stress. This insight may affect our advice to patients
about heart-healthy eating.
PMID- 10780094
TI - Who should receive the Lyme disease vaccine?
PMID- 10780096
TI - Avoiding tick bites
PMID- 10780095
TI - Tick trouble: overview of tick-borne diseases.
AB - Tick-borne diseases can be severe or even fatal, but when identified early, most
can be easily treated. Tick-borne diseases often present with nonspecific
symptoms. Therefore it is important for the primary care physician to be familiar
with the epidemiology of these diseases and their presentations. Although Lyme
disease is the most common and well-known of the many tick-borne diseases, Rocky
Mountain spotted fever, ehrlichiosis, and babesiosis are also threats throughout
the United States.
PMID- 10780097
TI - An elderly man with intermittent right arm numbness and polycythemia.
PMID- 10780098
TI - Angioplasty and stenting in acute coronary syndromes: who, when, how, and why.
AB - PTCA and stenting now form an integral part of therapy for acute coronary
syndromes and are important in achieving the optimal clinical outcome.
PMID- 10780099
TI - Raloxifene: a new choice for treating and preventing osteoporosis.
AB - Selective estrogen receptor modulators (SERMs) are a new class of drugs that
provide a new option for addressing the health challenges of postmenopausal
women. This review discusses the proposed mechanism of action of SERMs and
describes clinical findings on raloxifene, a SERM now available for treating and
preventing osteoporosis.
PMID- 10780100
TI - Pancreas transplantation in type 1 diabetes: hope vs reality.
AB - Pancreas transplantation can improve quality of life for patients with type 1
diabetes by eliminating hypoglycemic and hyperglycemic episodes, the need for
insulin injections, frequent self-monitoring of blood glucose levels, and dietary
restrictions. Increasing evidence suggests that it may slow the progression of
long-term diabetic complications. On the other hand, patients risk the adverse
effects of lifelong immunosuppression.
PMID- 10780101
TI - The HOPE study. Ramipril lowered cardiovascular risk, but vitamin E did not.
AB - The Heart Outcomes Prevention Evaluation (HOPE) study found that the ACE
inhibitor ramipril can lower the risk of atherosclerotic disease events and death
in patients without heart failure but with known atherosclerosis or with diabetes
plus at least one cardiovascular risk factor. This benefit was independent of
ramipril's effect on blood pressure. Additional benefits were a reduced risk of
diabetic nephropathy in diabetic patients, and a lower likelihood of newly
diagnosed diabetes. On the other hand, vitamin E in the doses and duration
studied (400 IU/day for 4.5 years) did not lower risk significantly.
PMID- 10780102
TI - The genetics, screening, and treatment of epithelial ovarian cancer: an update.
AB - Recent genetic findings are shedding light on who is at risk for epithelial
ovarian cancer, by far the most common of ovarian malignancies. Current screening
tests are inadequate, but a serum test of lysophosphatidic acid shows promise.
Clinical trials show that cisplatin or carboplatin plus paclitaxel increases
progression-free and overall survival times vs regimens that do not contain
paclitaxel, and that a carboplatin-paclitaxel regimen is less toxic than
cisplatin-paclitaxel and can be given on an outpatient basis. The development of
newer cytotoxic drugs and alternative routes of administering chemotherapy offers
hope of improved survival for women with advanced ovarian cancer.
PMID- 10780103
TI - It's time medicine stopped burying its mistakes.
PMID- 10780104
TI - [Evolutionary chromosomes and sex dimorphism].
AB - In order to understand the phenomenon of sex, it is not enough to know about its
reproductive role and role in recombination. In addition, knowledge of its
evolutionary role is required. Sexual differentiation allows us to test
evolutionary innovations in the male genome before they are transmitted to the
female genome. This is possible in the framework of dichronous evolution, when
the evolution of the male sex goes faster than the evolution of the female sex.
This implies that there clearly should be male genes, which are already present
in the male genome, but are not yet in the female genome; and vice versa, there
should exist female genes, which have already been lost by the male sex, but
still remain in females. Dichronicity results from different reaction norm of the
sexes. This interpretation implies (1) the nomadic behavior of genes in the
genome (2) the existence of evolutionary sexual dimorphism, which begins in the
form of modificational changes in the female sex followed by selection-derived
changes in the male sex; (3) the discovery of evolutionary roles of chromosomes
and the proposition of a new concept, according to which the Y-chromosome
represents a "gateway" for environment-related information coming to the genome,
i.e., place of "birth" and testing of new genes, which comprise the basis of
evolutionary sexual dimorphism--its initiator, accelerator, and regulator. The X
chromosome is the "transport" chromosome that transfers new genes from the Y
chromosomes into autosomes and therefore serves as a stabilizer, relaxer, and
liquidator of evolutionary sexual dimorphism; it also serves as repository of the
outgoing genes that await elimination. This concept provides for a new
interpretation of the appearance, localization, and movement of genes along
chromosomes and between them, and it sheds new light on the phenomena of
chromosomal inactivation, mobile genes, association of Y-chromosome with stress,
viruses, etc.
PMID- 10780106
TI - [Structure-physiological activity correlation for picolinic acid derivatives
based on quantum chemical data].
AB - Correlation between structure and properties for picolinic acid derivatives with
and without bimodal effect was evaluated by quantum chemical calculations.
Comparative data obtained by SCF MO method in the 3-21G/6-31G* basis indicate
lower ionization potential in picolinic acid derivatives with bimodal effect as
compared to those lacking this effect. This validates our previous assumption
that physiological bimodal effect is defined by the electron structure of the
molecules. Quantum chemical calculations allowed us to predict bimodal
physiological activity in amino-substituted derivatives of picolinic acid.
PMID- 10780105
TI - [Polyclonal antibodies, labeling radial nerve cells of the starfish Asterias
amurensis].
AB - The results of preliminary studies suggest that the cytoskeletal fraction of the
radial nerve of the starfish Asterias amurensis contained a 32 kDa protein, which
is tissue specific. This protein was isolated from the radial nerve by
preparative electrophoresis and used as an antigen for raising polyclonal
antibodies. When testing these antibodies on sections of the starfish tissues, it
was shown that they interact only with the proteins present in the radial nerve
cells. A conclusion was drawn that the raised antibodies may be used as a cell
marker when studying regeneration of the nervous system in starfish.
PMID- 10780107
TI - [Morpho-biochemical study of the liver and serum albumins during
tetrachloromethane intoxication and administration of antihypoxants,
antioxidants, and actoprotectors].
AB - Organism intoxication with tetrachloromethane induces a complex of
transformations in the liver and serum albumins system manifested in the liver as
necroses in the central lobe, dilatation of sinus capillaries and blood stasis in
them, increased content of total water, and changed magneto-relaxation properties
indicating decreased structurization of water. The system of serum albumins shows
decreased total concentration of albumins in the serum, decreased constant of 1
(phenylamino)-8-sulfonaphthalene probe binding, increased mean number of probe
binding per albumin molecule, and increased accessibility of probe in the protein
probe complex for the quencher indicating changed type of interaction between the
protein and fluorescent probe. Introduction of a antihypoxant, antioxidant, or
actoprotector has a positive effect on the condition of the liver and serum
albumins system: The studied indices are nearly completely normalized.
PMID- 10780108
TI - [Changes in the activity of superoxide dismutase, glutathione peroxidase,
microsomal lipid peroxidation, and content of trace elements in organs and
tissues following copper introduction].
AB - Chronic application of various copper concentrations on the skin decreases
endogenous levels of iron, zinc, and copper in the serum. Single introduction of
disperse copper positively correlates with the level of the oxidation products
and Fe/Zn ratio in the liver. Single introduction of ionic and electron-neutral
copper induces phased changes in superoxide dismutase and glutathione peroxidase
activities. Positive correlation between activities of these enzymes points to
efficient control of O2-radicals, dismutation products, and hydroperoxides level
by the antioxidant enzymes in animal tissues treated with copper.
PMID- 10780109
TI - [Indoleacetic acid levels in the potato organs during various stages of
ontogenesis and the role their dynamics in the tuber growth regulation].
AB - During ontogenesis of the potato (Solanum tuberosum L.), the content of
indoleacetic acid (IAA) in different organs was determined. The dynamics of IAA
in the leaves corresponded to changes in photosynthetic activity. The treatment
with IAA increased the intensity of photosynthesis. It was shown that the IAA
content increased in the leaves and that IAA ascended to the stem basal part in
the second half of vegetation. The accumulation of IAA in the stem basal part
gave rise to a positive gradient of sugar in the stem, differentiation of stolons
and transport of assimilate in the grown tubers. A correlation was found between
the content of IAA in tubers and the rate of its growth.
PMID- 10780110
TI - [Modeling of the plant community: individual oriented approach. II. A model of a
community].
AB - The individual-based approach to modeling of the plant cover dynamics is
discussed. This approach takes into account that the cover consists of individual
interacting plants, i.e., is a community. According to the principle of "minimal
angle of viewing", this approach can be considered as approaching the object
earlier considered from the energy standpoint (Monsi and Saeki, 1953; Khil'rni,
1957). An element of the model of community, balance model of plant dynamics, was
considered in part I of the article. The community model is 2-D, i.e., it
considers the growth and dying of plants in relation to their mutual geometrical
arrangement in the community. Mechanisms of division and re-division of the
territory among the plants of community are important elements of the community
model. These mechanisms use the Voronoi mosaic. Some results of the development
and analysis of the model of community are considered, such as the possibility of
non-monotonous competition in homogeneous communities and -3/2 rule considered as
"one of the most general principles of plant population biology" (White, 1980).
The 2-D individual-based approach to modeling can be an effective tool for
analysis of the influence of many "microscopic" features of the community
structure on its macroscopic behavior.
PMID- 10780111
TI - ['Conditioning factor' in plant cell cultures of various taxa].
AB - The activity of the "conditioning factor" from the cultures of plant cells of
various taxa was assayed in biotests with the tobacco and wheat cell cultures.
The conditioned media of crops did not activate the growth of a diluted (400
fold) culture of tobacco cells. Conditioned media from the cultures of cells of
other monocotyledonous plants, such as asparagus or spiderwort, stimulated the
tobacco culture growth like those from the cultures of cells of dicotyledonous
and gymnospermous plants. The growth of a diluted (2000-fold) culture of wheat
cells was activated by the conditioned media from all cell cultures used in these
experiments. We can propose that conditioning factors of monocotyledonous,
dicotyledonous and gymnospermous plants do not differ from each other in the
character of biological action and may have a similar chemical nature. The nil or
weak activity of conditioned media from the cultures of crop cells may be related
to the presence, in addition to the conditioning factors, of inhibitors of cell
culture growth.
PMID- 10780112
TI - [A boundary between palearctic and afrotropical faunistic kingdoms (based on the
lizard distribution (Reptilia, Sauria))].
AB - In order to define the limit between Palearctic and Afrotropical kingdoms, we
studied the apparent transition zone between them which we limited by the North
range boundary of Agama agama--the northernmost representative of a typical
Afrotropical genus--and by the South range boundary of the southernmost
representatives of Palearctic genera Acanthodactylus, Chalcides, Stenodactylus,
and Tarentola. We also considered fauna of Southwest Arabian lizards including a
representative of Afrotropical genus (Latastia longicaudata). Similarity of range
and origin allowed us to class all species living within these boundaries into
nine groups: Palearctic, Afrotropical, widespread, Afroarabian, zone endemics of
Palearctic genera, zone endemics of Afrotropical genera, zone endemics of
Afroarabian genera, zone endemics of tropical genera, and zone endemics at the
generic level. Range superposition allowed us to map species abundance of each
group. Predominance (over 50%) of Palearctic or Afrotropical species on the
studied territory allowed us to assign it to the corresponding faunistic kingdom.
The regions where neither of these groups exceeded 50% were assigned to the
transition zones.
PMID- 10780113
TI - [Breeding biology of the whiskered auklet (Aethia pygmaea): incubation, chick
growth, and feather ontogenesis].
AB - This is the second publication on the results of studies of the whiskered auklet
breeding biology on Buldir Island. In 1993, according to the time of chick
hatching the egg-laying period began in late April-early May. The single egg was
incubated by both parents, which relieved each other once a day, usually at early
night. Among the chicks under observation, the first hatched on June 11; the
median of hatching was on June 17. After hatching, the egg shell usually remained
in the nest. The chick was continuously brooded by one of parents for the first
several days but since the age of 7-9 days, it stayed in the nest by itself
during the daytime. Each parent fed the chick once a day, at early night,
although occasional feedings were recorded also during daytime and at dawn. A
newly hatched chick was covered by typical embryonal (natal) down. The remiges,
rectrices, their coverts, and large feathers on pteryla humeralis had a mesoptile
stage during their growth (the second down generation). The juvenile plumage
consisted of semiplumes of types I and II and contour feathers of type I and,
possibly, type II. In fledglings, the ornamental feathers were underdeveloped:
the crest was absent and facial plumes only began growing. By reaching 100 g, the
chicks left their nests at the age of about 37 days. A longer nesting period than
in other Aethia auklets appears to be related to a low feeding rate due to the
nocturnal activity in the colony.
PMID- 10780114
TI - [The morphological variability coordinated with the population cycle of the
widely distributed (the water vole Arvicola terrestris L.) and mountain (the big
eared vole Alticola macrotis Radde) vole species].
AB - This paper presents an analysis of variation of skull size and shape in the
course of population cycles of two ecologically different vole species: water
vole and high-mountain vole. We have found consistent changes of the direction,
rate, and balance of morphogenesis during population cycles. We discuss the role
of intra-populational factors and inter-populational variation during the
territorial expansion of the species.
PMID- 10780115
TI - [Reactivity of blood vessels: the role of mechanical stimulation and initial
tone].
AB - We have studied hemodynamic and some other correlates of the myogenic and
endothelium-dependent control of vessel tone and reactivity in experiments with
anesthetized cats and rats, as well as in vitro experiments with isolated
segments of the mesenteric and tail artery of the rats. We present evidence for
the important role of mechanical stimulation of endotheliocytes in the formation
of vasodilation in skeletal muscles in response to increased amplitude of the
pulse pressure, as well as in response to their active or passive contractions.
Interference between mechanical, neurohumoral, and metabolic effects on vascular
tone were studied. In spontaneously hypertensive rats, endothelium-dependent
vasodilation initiated by increased oscillations of pulse pressure is diminished.
We also describe relationships between systemic hemodynamic responses and the
initial arterial tone.
PMID- 10780116
TI - [Study of the photodynamic effect of new photosensitizers on the single neuron].
AB - We studied reactions of isolated crayfish mechanoreceptor neurons to photodynamic
effects of various photosensitizers: methylene blue, chlorins e6 and p6, sulfated
allumophthalocyanin Photosens, Janus green B, protoporphyrin IX, and two
derivatives of hematoporphyrin IX, Photoheme and Photosan-3. The neurons were
irradiated by a helium-neon laser (632.8 nm, 0.3 Wt/cm3) after 30-min
photosensitization. They proved to be very sensitive to the photodynamic effect:
When the cells stained by photosensitizers at nanomolar concentrations were
irradiated, their firing activity underwent irreversible changes and they died.
The dynamics of the firing activity of the neurons depended on the
photosensitizer type and concentration. Photosens, Photoheme and chlorin p6
proved to be the most efficient.
PMID- 10780117
TI - [Geoinformational model of the carbon reserve of the Russian tundra zone].
AB - We present a summary of our own gas measurement data on biogenic fluxes of CO2 in
various ecosystems of the Russian tundra zone, using seasonal and geographical
extrapolations based on mathematical simulation modeling. The model follows
construction principles of geoinformational systems and consists of (1) a
computer map of tundra landscape boundaries; (2) a meterological database; (3) a
model of changes of the phytomass; and (4) the actual model of carbon fluxes. The
model, which uses a 10-day step, allows estimates of regional and landscape
associated macroscopic carbon fluxes and predicts the response of the tundras to
climatic changes. The data obtained are in good agreement with independently
obtained estimates of the major characteristics of tundra carbon balance.
PMID- 10780118
TI - [Study of the new settler Beroe ovata in the Black sea].
AB - Primary data on population, size, and distribution of a new settler--comb jelly
Beroe ovata--in the Black Sea are presented. We studied certain aspects of its
nutrition, consumed organisms, and digestion time. Comb jellies Mnemiopsis leidyi
and Pleurobachia pileus were established as the nutritional targets of B. ovata.
Mnemiopsis proved to be more accessible and assimilable. Preliminary data on
metabolic level and threshold oxygen content in B. ovata were obtained;
proportions of dry and wet weight of B. ovata were determined. Population changes
of new settler Mnemiopsis and other jellylike animals in the Northeast part of
the sea induced by B. ovata were analyzed. We observed sharp decrease in
population of Mnemiopsis, a species that induced degradation of the Black Sea
ecosystem within the last decade.
PMID- 10780119
TI - Adolescent and family predictors of physical aggression, communication, and
satisfaction in young adult couples: a prospective analysis.
AB - This study tested a model wherein the family conflict, depression, and antisocial
behavior of 254 adolescents (mean age = 17 years; 63% female) are prospectively
related to functioning within a marital (51%) or dating relationship in young
adulthood (mean age = 23 years). Family aversive communication in adolescence and
adolescent antisocial behavior predicted couple physical aggression. Family
aversive communication predicted dyadic satisfaction and aversive couple
communication for married women and dating men. Among those with partners who
reported little antisocial behavior, adolescent antisocial behavior inversely
predicted couple satisfaction and facilitative behavior. Partner antisocial
behavior did not mediate the relation between adolescent characteristics and
couple functioning. Findings emphasize the importance of the early family
environment and psychopathology of the adolescent in the development of adaptive
couple relationships.
PMID- 10780120
TI - Family, peer, and individual correlates of depressive symptomatology among U.S.
and Chinese adolescents.
AB - This study examined the correlates of symptoms of depressed mood among
adolescents in 2 dramatically different cultures (n = 502 in Tianjin, People's
Republic of China; n = 201 in greater Los Angeles). Gender, stressful life
events, perceived parental warmth, and conflict with parents were associated in
the expected direction with depressive symptoms in each cultural setting. As
predicted, regression analyses showed that the quality of family relationships
and grades in school had significantly stronger associations with depressive
symptoms among Chinese youths than among U.S. youths, whereas gender differences
in depressive symptoms were greater among the U.S. youths. Peer warmth moderated
the effects of particular risk factors for depressive symptoms in each cultural
setting.
PMID- 10780121
TI - Predictors of work adjustment in bipolar I patients: a naturalistic longitudinal
follow-up.
AB - This study explored the clinical and psychosocial predictors of work adjustment
in 52 Bipolar I patients over a 2-year longitudinal period and examined
associations between work functioning and social relationships, personality
features, stressful life events, and clinical variables. Analyses indicated that
psychosocial variables (personality disorder symptoms and social functioning)
added significantly to prediction of work functioning after clinical variables
were entered. Stressful life events were not associated with work adjustment.
Overall, presence of a good quality supportive relationship was the strongest
unique predictor of work. The results highlight the need to study functional
outcomes in patients, especially because they appear only modestly associated
with clinical status.
PMID- 10780122
TI - Long-term posttreatment functioning among patients with unipolar depression: an
integrative model.
AB - This study tested an integrative structural equation model of posttreatment
functioning among 165 depressed patients followed for an average of 9 years after
the end of an episode of treatment. The model examined (a) the link between life
change and psychosocial resource change and (b) the role of resource change in
mediating the relationship between life change and change in depression. An
increase in the preponderance of negative over positive life events was
associated with a decline in resources and an increase in depressive symptoms. A
decline in resources was associated with an increase in depressive symptoms. The
association between changes in events and depressive symptoms was completely
mediated through resource change. These findings indicate that life stressors
contribute to posttreatment depression through an erosion of personal and social
resources.
PMID- 10780123
TI - Effects of transdermal nicotine patches on abstinence-induced and cue-elicited
craving in cigarette smokers.
AB - The impact of a transdermal nicotine patch on smokers' craving for cigarettes and
reactivity to smoking cues was investigated. Sixty-one smokers were assessed
during 2 sessions separated by 6 hr. Cue reactivity to imaginal and in vivo
smoking and nonsmoking stimuli was evaluated during both sessions. During the
interval between sessions, participants were abstinent from cigarettes and wore
either a nicotine transdermal (21 mg) or placebo patch. In both sessions,
exposure to in vivo and imaginal smoking stimuli elicited cue-specific increases
in craving, negative affect, vividness, heart rate, and skin conductance. The
nicotine patch attenuated craving and other effects induced by abstinence from
cigarettes but had no selective impact on craving or any other reaction elicited
by smoking cues. These results are discussed in terms of models of craving and
clinical implications of transdermal nicotine for craving reduction.
PMID- 10780124
TI - Treatment of spit tobacco users with transdermal nicotine system and mint snuff.
AB - The purpose of this study was to examine the effects of nicotine patch and mint
snuff (a nonnicotine product) on craving, withdrawal symptoms, and treatment
outcome. This study involved a 2 x 2 factorial design, with Active Nicotine
Versus Placebo Patch as one of the factors and Mint Snuff Versus No Mint Snuff as
the other factor. Spit tobacco users (N = 402, n = 100-101 in each condition)
were randomly assigned to 1 of the 4 treatment conditions for a period of 10
weeks. Treatment outcome was measured up to 62 weeks. The results showed that the
nicotine patch was effective in increasing short-term abstinence over the placebo
patch and in reducing craving and withdrawal signs and symptoms from spit
tobacco. Although mint snuff was not effective in enhancing treatment outcome, it
reduced craving and withdrawal symptoms. No interaction effects were observed. At
this time, the use of the nicotine patch and mint snuff should be primarily
considered for the reduction of craving and withdrawal symptoms.
PMID- 10780125
TI - Give them prizes, and they will come: contingency management for treatment of
alcohol dependence.
AB - This study evaluated the efficacy of a contingency management (CM) procedure that
provided opportunities to win prizes as reinforcers. At intake to outpatient
treatment, 42 alcohol-dependent veterans were randomly assigned to receive
standard treatment or standard treatment plus CM, in which they earned the chance
to win prizes for submitting negative Breathalyzer samples and completing steps
toward treatment goals. Eighty-four percent of the CM participants were retained
in treatment for an 8-week period compared with 22% of the standard treatment
participants (p < .001). By the end of the treatment period, 69% of those
receiving CM were still abstinent, but 61% of those receiving standard treatment
had used alcohol (p < .05). These results support the efficacy of this CM
procedure. Participants earned an average of $200 in prizes. This CM procedure
may be suitable for use in standard treatment settings because prizes can be
solicited from the community.
PMID- 10780126
TI - Predictors and outcomes of posttraumatic stress disorder in World War II veterans
exposed to mustard gas.
AB - Current posttraumatic stress disorder (PTSD) associated with participation in
secret military tests of mustard gas during World War II was assessed in 363 male
military veterans who were randomly sampled from a registry developed by the
Department of Veterans Affairs. Current prevalence was 32% for full PTSD and 10%
for partial PTSD. Prevalence of PTSD varied as a function of risk and protective
factors, including volunteering, physical symptoms during the tests, and
prohibited disclosure. Prediction of partial PTSD was weaker than prediction of
full PTSD. Veterans with full PTSD reported poorer physical health, a higher
likelihood of several chronic illnesses and health-related disability, greater
functional impairment, and higher likelihood of health care use than those with
no PTSD. Veterans with partial PTSD also had poorer outcomes than did veterans
with no PTSD in a subset of these domains. There is discussion of the traumatic
elements of experimental mustard gas exposure, vulnerability to PTSD, and the
relevance of these findings to understanding the broad range of outcomes
associated with PTSD.
PMID- 10780127
TI - Ambulatory cardiovascular activity in Vietnam combat veterans with and without
posttraumatic stress disorder.
AB - The present study investigated the relationship between daily diary affect
ratings and ambulatory cardiovascular activity in 117 male Vietnam combat
veterans (61 with posttraumatic stress disorder [PTSD] and 56 without PTSD).
Participants completed 12-14 hr of ambulatory monitoring and daily diary affect
ratings. Compared with veterans without PTSD, veterans with PTSD reported higher
negative affect and lower positive affect in daily diary ratings. No differences
were detected for mean laboratory initial recordings or mean ambulatory heart
rate (HR), systolic blood pressure (SBP), or diastolic blood pressure (DBP).
However, compared with veterans without PTSD, veterans with PTSD demonstrated
higher SBP and DBP variability and a higher proportion of HR activity (compared
with initial recording values) during daily activity. There was a significant
Time of Day x Group interaction for mean HR, with a trend for PTSD participants
to maintain HR levels during evening hours.
PMID- 10780128
TI - Treatment settings for persons with alcoholism: evidence for matching clients to
inpatient versus outpatient care.
AB - This study compared inpatient, intensive outpatient, and standard outpatient
treatment settings for persons with alcoholism and tested a priori hypotheses
about the interaction of setting with client alcohol involvement and social
network support for drinking. Participants (N = 192) were assigned randomly in
cohorts to 1 of the 3 settings. The settings did not differ in posttreatment
primary drinking outcomes, although inpatients had significantly fewer jail and
residential treatment days combined than outpatients. Clients high in alcohol
involvement benefited more from inpatient than outpatient care; the opposite was
true at low alcohol involvement levels. Network drinking support did not moderate
setting effects. Clients low in cognitive functioning also appeared to benefit
more from inpatient than outpatient care. Improved outcomes might be achieved by
matching degree of alcohol involvement and cognitive functioning to level of
care.
PMID- 10780129
TI - Similarity of prior trauma exposure as a determinant of chronic stress responding
to an airline disaster.
AB - The cumulative effects of trauma were examined in 108 workers at the site of a
major air disaster at 4 time points over a year following the crash. The
influence of trauma history on chronic distress and physiological arousal
associated with the crash were examined. Stress levels were expected to differ on
the basis of the similarity of prior trauma exposure to work at the crash site.
Prior traumatic exposure that was "dissimilar" to this type of work was
associated with greater vulnerability to crash-related stress, that is, more
distress and crash-related intrusions during the year following the crash.
Accumulation of a variety of different traumatic experiences appeared to
sensitize workers to the new stressor and to perpetuate chronic stress.
Understanding the role of trauma history is important for improving intervention
efforts aimed at alleviating stress following a trauma.
PMID- 10780130
TI - Detecting and describing preventive intervention effects in a universal school
based randomized trial targeting delinquent and violent behavior.
AB - This study examined theoretical, methodological, and statistical problems
involved in evaluating the outcome of aggression on the playground for a
universal preventive intervention for conduct disorder. Moderately aggressive
children were hypothesized most likely to benefit. Aggression was measured on the
playground using observers blind to the group status of the children. Behavior
was micro-coded in real time to minimize potential expectancy biases. The
effectiveness of the intervention was strongly related to initial levels of
aggressiveness. The most aggressive children improved the most. Models that
incorporated corrections for low reliability (the ratio of variance due to true
time-stable individual differences to total variance) and censoring (a floor
effect in the rate data due to short periods of observation) obtained effect
sizes 5 times larger than models without such corrections with respect to
children who were initially 2 SDs above the mean on aggressiveness.
PMID- 10780131
TI - The effect of systematic variation in retrospective conduct disorder reports on
antisocial personality disorder diagnoses.
AB - A diagnosis of antisocial personality disorder (ASPD) requires a conduct disorder
(CD) diagnosis. A CD diagnosis is often obtained retrospectively. This study
tested the influence of current behavior on CD recall and the association between
recent behavior change and inconsistencies in contemporaneous and retrospective
CD reports. Five hundred young adults reported ASPD; retrospective CD; current
problem behavior; and, at ages 12 to 15 years, contemporaneous CD. True-positive,
true-negative, false-positive, and false-negative CD and ASPD groups were
identified. The results supported the hypotheses. Participants whose current
behavior agreed with past behavior provided reliable retrospective CD reports.
Inaccurate diagnoses occurred among participants whose current behavior was
inconsistent with past behavior, either becoming more problematic (CD and ASPD
false positives) or less problematic (CD and ASPD false negatives) over time.
PMID- 10780132
TI - Self-regulation of affect in attention deficit-hyperactivity disorder (ADHD) and
non-ADHD boys: differences in empathic responding.
AB - This study examined differences in empathy and other emotions between boys with
and without attention deficit-hyperactivity disorder (ADHD). Empathy was measured
by an empathy response task (ERT) and through self- and parent reports of
emotion. On the ERT, children responded verbally to 8 fictitious stories. Results
from the ERT revealed that boys with ADHD were less empathic than boys without
ADHD. Boys with ADHD less frequently matched the emotion they identified in the
character with the one identified in themselves and gave fewer character-centered
interpretations in their descriptions of the character's emotion. Parent-report
data revealed that boys with ADHD exhibited more behavioral manifestations of
sadness, anger, and guilt than did boys without ADHD. No differences were found,
however, on measures of emotional intensity or emotional reactions to external
contingencies. The results are discussed with respect to current theories of
ADHD.
PMID- 10780133
TI - The presence of security blankets or mothers (or both) affects distress during
pediatric examinations.
AB - Because of parental interference, some pediatricians prefer examining children
without parents nearby. Can inanimate, noninterfering attachment agents placate
children during medical evaluations? Accompanied through random assignment by
their mother, blanket, mother plus blanket, or no supportive agent, 64 blanket
attached or blanket-nonattached 3-year-olds underwent 4 routine medical
procedures. Behavioral and physiological measures showed that mothers and
blankets (for children attached to them) equally mitigated distress compared with
no supportive agents. However, simultaneously presenting 2 attachment agents did
not produce additive soothing effects. For comforting blanket-attached children
during moderately upsetting medical procedures, blankets can function as
appropriate maternal substitutes. Distress evidenced by children with no
attachment agent demonstrates the undesirability of conducting medical
examinations without supportive agents.
PMID- 10780134
TI - A national survey of practicing psychologists' attitudes toward psychotherapy
treatment manuals.
AB - There has been considerable debate and little empirical data on the role of
psychotherapy treatment manuals in clinical practice. Attitudes toward treatment
manuals are a potentially important determinant of how likely practitioners are
to use manual-based treatments in clinical practice. A total of 891 practicing
psychologists nationwide were surveyed about their attitudes toward treatment
manuals and their ideas about the content of manuals. Practitioners held widely
varying attitudes toward treatment manuals, and ideas about what constitutes a
manual were associated with attitudes in a predictable way. Recommendations are
made for how to gather more useful information about practitioners' attitudes
toward the many changes affecting current models of clinical practice.
PMID- 10780135
TI - Therapeutic alliance: predicting continuance and success in group treatment for
spouse abuse.
AB - This study examined the role of the therapeutic alliance between client and
therapist on group treatment outcome in 70 husband-to-wife violent couples.
Strength of husbands' alliance assessed at Session 1 was positively associated
with treatment outcome, as measured by decreased husband-to-wife mild and severe
psychological and physical aggression. Strength of wives' alliance was unrelated
to treatment outcome. Finally, although alliance was related to treatment
outcome, it was unrelated to treatment completion.
PMID- 10780136
TI - Effectiveness of an Internet-based program for reducing risk factors for eating
disorders.
AB - This study evaluated an Internet-delivered computer-assisted health education
(CAHE) program designed to improve body satisfaction and reduce weight/shape
concerns--concerns that have been shown to be risk factors for the development of
eating disorders in young women. Participants were 60 women at a public
university randomly assigned to either an intervention or control condition.
Intervention participants completed the CAHE program Student Bodies. Measures of
body image and disordered eating attitudes were assessed at baseline,
postintervention, and 3-month follow-up. At follow-up, intervention participants,
compared with controls, reported a significant improvement in body image and a
decrease in drive for thinness. This program provides evidence for the
feasibility and effectiveness of providing health education by means of the
Internet.
PMID- 10780137
TI - Integrative behavioral couple therapy: an acceptance-based, promising new
treatment for couple discord.
AB - Although traditional behavioral couple therapy (TBCT) has garnered the most
empirical support of any marital treatment, concerns have been raised about both
its durability and clinical significance. Integrative behavioral couple therapy
(IBCT) was designed to address some of these limitations by combining strategies
for fostering emotional acceptance with the change-oriented strategies of TBCT.
Results of a preliminary clinical trial, in which 21 couples were randomly
assigned to TBCT or IBCT, indicated that therapists could keep the 2 treatments
distinct, that both husbands and wives receiving IBCT evidenced greater increases
in marital satisfaction than couples receiving TBCT, and that IBCT resulted in a
greater percentage of couples who either improved or recovered on the basis of
clinical significance data. Although preliminary, these findings suggest that
IBCT is a promising new treatment for couple discord.
PMID- 10780138
TI - Telephone-administered cognitive-behavioral therapy for the treatment of
depressive symptoms in multiple sclerosis.
AB - This study examined the efficacy of an 8-week telephone-administered cognitive
behavioral therapy (CBT) for the treatment of depressive symptomatology in
multiple sclerosis (MS) patients. The treatment, Coping with MS (CMS), included a
patient workbook designed to structure the treatment, provide visual aids, and
help with homework assignments. Thirty-two patients with MS, who scored at least
15 on the Profile of Mood States Depression-Dejection scale, were randomly
assigned to either the telephone CMS or to a usual-care control (UCC) condition.
Depressive symptomatology decreased significantly in the CMS condition compared
with the UCC condition. Furthermore, adherence to interferon beta-1a, a disease
modifying medication for the treatment of MS, was significantly better at the 4
month follow-up among patients who received CMS as compared with those in the UCC
condition.
PMID- 10780139
TI - Children's perceptions of peers with somatic symptoms: the impact of gender,
stress, and illness.
AB - OBJECTIVE: To investigate how illness characteristics influence children's
responses to ill peers. METHODS: A sample of 363 4th and 5th graders responded to
a vignette describing a peer with abdominal pain. In a 2 x 2 x 2 x 2 design,
conditions varied by (a) evidence for organic disease, (b) presence of stress,
(c) sex of vignette character, and (d) sex of respondent. Children rated symptom
severity, liking for the peer, and whether the peer should be excused from normal
responsibilities. RESULTS: Same sex preferences significantly influenced
children's liking for a peer. Children viewed symptoms with an organic etiology
as more severe than those without one. Under certain conditions, symptom severity
judgments mediated the relation between the presence of organic disease and (a)
liking and (b) granting relief from responsibility. The presence of stress had
little effect on ratings of symptom severity, liking, or relief from
responsibility. CONCLUSIONS: Gender and evidence of organic disease influence
children's perceptions of and responses to symptomatic peers.
PMID- 10780140
TI - Children's attitudes and behavioral intentions toward a peer presented as obese:
does a medical explanation for the obesity make a difference?
AB - OBJECTIVE: To examine the effect of information on children's attitudes and
behavioral intentions toward a peer presented as obese. METHODS: Children (N =
184) were randomly assigned to observe a video of a boy or girl in one of three
conditions: average-weight, obese, obese with medical information explaining the
obesity. They rated stereotypical attitudes on the Adjective Checklist and
behavioral intentions on the Shared Activities Questionnaire (SAQ-B). RESULTS:
Ratings were generally more favorable for the average-weight than for the obese
condition. However, provision of medical information had a positive effect on
attitudes toward the obese peer only for younger children and a negative effect
on willingness of older children to share academic activities with the peer. Boys
and girls showed more positive behavioral intentions toward the same-sex target
child regardless of obesity condition. CONCLUSIONS: Information explaining
obesity has a minimal positive effect on children's attitudes and behavioral
intentions toward a peer presented as obese.
PMID- 10780141
TI - Children with pediatric conditions: can peers' impressions be managed? And what
about their friends?
PMID- 10780142
TI - A reexamination of a childhood cancer stereotype.
AB - OBJECTIVE: To examine whether young adults have stereotypical beliefs toward
children who have been treated for cancer. METHODS: Undergraduate participants
read a vignette describing a child labeled either healthy (HL), in remission from
cancer and no longer undergoing treatment (RCL), or in remission and still
undergoing treatment (RCTL) and rated the child on the Ratings of the Child
Questionnaire (ROCQ). Univariate and multivariate analyses of variance were
conducted. RESULTS: Participants rated the HL child more positively than the RCL
or RCTL child; the RCL and RCTL child ratings did not differ. Females evaluated
the child more positively than did males. CONCLUSIONS: These results support
previous findings of a childhood cancer stereotype. However, effect sizes were
small, which may indicate a weak stereotype with these specific participants.
PMID- 10780143
TI - Beyond mothers and children: finding the family in pediatric psychology.
PMID- 10780144
TI - Response to hypo- and hyperglycemia in adolescents with type I diabetes.
AB - OBJECTIVE: To assess the appropriateness of adolescents' responses to hypo- and
hyperglycemia and to examine the relationship of patient age, gender, diabetes
duration, diabetes knowledge, parental supervision, and glycemic control to
response appropriateness. METHODS: We assessed 125 adolescents' responses to
daily episodes of hypo- and hyperglycemia by 24-hour recall interviews; responses
were coded for type and appropriateness. RESULTS: Adolescents responded
inappropriately to 38% of hypoglycemic and 29% of hyperglycemic episodes.
Parental supervision of blood glucose testing did not increase the likelihood of
an appropriate response; in the case of hyperglycemic episodes, it appeared to be
counterproductive. Adolescents who responded inappropriately to hyperglycemia
were also older but not different from those who responded appropriately by
gender, disease duration, diabetes knowledge, or glycemic control. CONCLUSIONS:
Health providers and family members may underestimate adolescents' difficulty
managing hypo- and hyperglycemia appropriately. The presence of parental
supervision does not ensure an appropriate response; parents may be particularly
misinformed about the management of hyperglycemia.
PMID- 10780145
TI - Brief report: cautions against using the Stanford-Binet-IV to classify high-risk
preschoolers.
AB - OBJECTIVE: To explore concurrent and predictive validity of the Stanford-Binet:
Fourth Edition (SB-IV) by comparing scores on the SB-IV with scores from the
Battelle Developmental Inventory (BDI) and later achievement scores in
preschoolers at risk due to very low birthweight, and/or intraventricular
hemorrhage (IVH) and other medical complications. METHODS: At ages 3,4, and 5, 92
preschoolers were tested with the SB-IV and BDI as part of an 8-year early
intervention follow-up. RESULTS: The SB-IV and BDI concurrent correlations at
ages 3, 4, and 5 were statistically significant (r = .73-.78, p < .0001), as were
predictive correlations (r = .58-.85, p < .0001). However, the BDI and SB-IV
failed to place the children in the same categories for intervention services.
With the BDI as the comparison measure, SB-IV failed to detect 87% of the
children who were "delayed" (by BDI) at age 3 and 50% of the "delayed" children
at age 5. CONCLUSIONS: Caution is recommended when using the SB-IV to assess high
risk for early intervention eligibility.
PMID- 10780146
TI - Cognitive and psychomotor development of infants with orofacial clefts.
AB - OBJECTIVE: To compare at ages 3, 12, and 24 months the cognitive and psychomotor
development of 29 infants with cleft lip and palate (CLP), 28 infants with cleft
palate only (CPO), and a demographically matched comparison (COMP) group of 69
infants; to examine predictors of cognitive status at age 24 months in the cleft
group. METHODS: Infants were administered the Bayley Scales of Infant Development
(BSID), mother-infant interactions were observed, and medical records were
reviewed. RESULTS: CLP and CPO groups scored lower than the COMP group on the
BSID, but did not differ from one another. Cleft group infants scored lower than
COMP group infants on BSID items assessing nonverbal and expressive language
skills. Quality of maternal interaction predicted the 2-year Mental Development
Index (MDI) scores of infants with clefts. CONCLUSIONS: Infants with clefts show
relative deficits in cognitive and psychomotor development. Cognitive deficits
are apparent in nonverbal as well as verbal areas of performance.
PMID- 10780147
TI - The autopsy in the 21st century: time for reconsideration.
AB - In recent years, the autopsy rate has dramatically declined. Using three cases,
we attempt to explore the current questions concerning the value of the autopsy.
The discussion centers around the importance of the autopsy to medicine and
family members of the deceased, the impact of technological advances on the
autopsy, and discordant pre- and post-mortem diagnoses. We conclude that the
decrease in autopsy rates is secondary to underutilization of the autopsy as a
diagnostic and educational tool.
PMID- 10780148
TI - Noninvasive estimation of pulmonary capillary wedge pressure from computed
radiography.
AB - PURPOSE: This study was undertaken to see if computed radiography (CR) could be
used to estimate pulmonary capillary wedge pressure (PCWP). METHODS: Radiographic
measurements of pulmonary artery-bronchus ratios (ABR), cardiomegaly,
interstitial edema, alveolar edema, and pleural effusion, obtained from portable
CR images of patients admitted to an intensive care unit, were compared to
hemodynamic measurements of PCWP. We prospectively predicted a normal PCWP when
ABR was < or = 1.0, and an elevated PCWP when ABR was > or = 1.1. RESULTS: There
was a significant difference between mean ABR in those with normal PCWP (1.014 +/
0.259) and those with elevated PCWP (1.422 +/- 0.234) (p < 0.0001). There was a
positive correlation between PCWP and ABR (r = 0.38, r2 = 0.147, p = 0.0001). ABR
was 95% sensitive, 86% specific, and 93% accurate in predicting PCWP (p =
0.0001). Cardiomegaly, interstitial edema, alveolar edema, and pleural effusion
were not as useful. CONCLUSIONS: Measurements of ABR from portable CR images can
be used to estimate PCWP.
PMID- 10780149
TI - The medico/legal year in review--1999.
PMID- 10780150
TI - Procuring for profit ... a fetal dilemma.
PMID- 10780151
TI - [Classical themes].
PMID- 10780152
TI - [Psychotherapy of posttraumatic stress disorders].
AB - Since the diagnosis of posttraumatic stress disorder (PTSD) was introduced in DSM
III in 1980, a variety of psychotherapeutic approaches have been developed to
address the specific problems and needs of traumatized patients. Successful
treatment of PTSD requires a well thought-out therapeutic attitude. The therapist
must find a well-balanced position between over-identification and turning away
out of helplessness. A sensation-seeking attitude should be avoided as should the
danger of vicarious traumatisation. In many instances, PTSD can not be treated
sufficiently by psychotherapy alone: a comprehensive, multi-modal treatment plan
may include pharmacotherapeutic, physical, social, legal, and other
interventions. Early psychotherapeutic interventions in the immediate aftermath
of a traumatic event follow the rules of crisis intervention (immediacy, focus on
the current problems, time limitation). Special attention should be paid to the
issues of developing a trusting therapeutic relationship, creating an atmosphere
of safety, helping the patient to regain control over and/or distance himself
from intrusive recollections. Eye Movement Desensitization and Reprocessing
(EMDR) and other "power therapies" can offer quick relief from symptoms. After
collective traumatization, psychological debriefings are widely used although the
evidence for their usefulness in preventing PTSD is questionable. In patients
with chronic PTSD, the psychotherapist should not work exclusively on the
traumatic event and its sequelae: treatment should be oriented towards the future
rather than the past. Instead of exploring, the therapist should try to activate
the patients' resources and help them to find new meaning in their future life.
PMID- 10780153
TI - [ "Weight phobia". A discussion of the problem of "atypical" and "not otherwise
specified" eating and weight disorders].
AB - A number of authors have stated that the problem of classifying patients whose
diagnosis does not meet all the criteria of anorexia and bulimia nervosa has not
been satisfactorily solved. The question has been asked if it is justified to
regard characteristics like "weight phobia" or body image disturbance as valid
diagnostic criteria. In the present study the differences observed in three
groups of patients with eating and weight disorders (anorexia: n = 42; bulimia: n
= 29; atypical group without "weight phobia": n = 14) were compared using the
Giessen-Test. The atypical group was shown to be significantly more "tractable"
on scale 2 than the main groups, which achieved a higher score on "dominance".
Significant differences between the atypical group and the "uncontrolled" group
of patients with bulimia were noted for scale 3, with the atypical group showing
comparable results to those recorded in the anorexic group on "compulsiveness".
The authors discuss the significance of the results under an epistemological
aspect. The description and classification of clinical phenomena which is based
on the clinical manifestation of the disorder independently of theoretical
concepts is therefore indispensible for realising a uniform basis for
communication by researchers worldwide. Equally indispensible is the
differentiation or "extension" of the classification to allow a more detailed
systematic categorisation guided along specific theoretical concepts. This
requires the operational definition of psychopathological and psychodynamic
criteria as, e.g. "the struggle for identy" or the "relentless pursuit of
thinness". The experiences with the OPD (Operationalized Psychodynamic Diagnosis;
1996) have shown this to be a difficult but viable approach.
PMID- 10780155
TI - [The effectiveness of the initial interview at a psychosomatic- psychotherapeutic
outpatient unit].
AB - In a cross sectional study of 1945 consecutive patients seen at a psychosomatic
psychotherapeutic outpatient unit between 1993 and 1995, we investigated how the
therapists assessed the effectiveness of their work and what correlations there
were with patient characteristics and with the way the therapists conducted the
initial session. The therapists' ratings indicated that about two thirds of the
patients benefited from the consultation. In the multivariate analysis of the
data the most important determinants of effectiveness were found to be the
patient's motivation, the ICD diagnosis, the patient's level of personality
organisation and the reason for the consultation. In addition, we did a one-year
follow-up of 260 patients to analyse the determinants that help patients to agree
to the proposed treatment plan. Of the 235 patients for whom treatment was
recommended, 174 (74%) actually began a treatment program. Our results show that
a patient is more likely to accept the treatment recommendation if the therapist
conducts the session in a certain way (e.g. provides detailed information) and
helps the patient to find an appropriate therapist.
PMID- 10780154
TI - [Long-term changes in borderline symptoms of patients after client-centered group
psychotherapy].
AB - In a follow-up study the long-term changes of borderline symptomatic of 14
patients with the diagnosis borderline personality disorder (criteria by Kernberg
and Rorschach test) are compared with 13 patients with diagnosis schizophrenia
and 16 patients with diagnosis depression (each case according to ICD-9
criteria). The Diagnostic Interview for Borderline Patients (DIB) is evaluated to
comprehend the structure and kinds of borderline symptoms before and 4 years
after treatment. Borderline patients are treated in a setting of client-centred
group psychotherapy (twice a week, approximately 100 sessions). The treatment of
the patients joining the control group is based on clinical standard. As a result
all patients reduced the borderline-like symptoms. However, the most significant
changes can be seen in the borderline group. 2 out of 14 borderline patients
still fulfill the DIB Criteria of borderline personality disorder. Nevertheless,
there are differences in the reduction of specific categories of borderline
symptoms. The greatest changes are in the categories "loss of impulse control"
and "psychotic episodes", whereas there are only slight improvements in the
category "interpersonal relationships".
PMID- 10780156
TI - [Do patients with rheumatoid arthritis suppress anger and aggression?].
AB - Given the contradictory findings on aggression in patients with rheumatoid
arthritis (RA), this topic was examined again in two studies. In both studies RA
patients and patients with arthrosis were compared (in-patients in study I, n =
28 in each sample; out-patients in study II, each sample comprising 22 subjects).
Two aggression/anger inventories (Fragebogen zur Erfassung von
Aggressivitatsfaktoren = FAF and State-Trait-Anger-Expression Inventory = STAXI)
with a total of 10 scales were used for comparison. Samples were matched for
gender and age; duration and severity of illness were used as covariates. No
replicable differences between groups were found in any variable. Our results do
not support aggression theories of rheumatoid arthritis.
PMID- 10780159
TI - [Self concept and parental images in patients with affective disorders--a
clinical study with the Giessen Test].
AB - The relationship between self, ideal self and normative self was studied in a
sample of 139 patients with affective disorders and 73 patients with orthopaedic
complaints. The depressive patients showed significant-asymmetric relationships
between self and ideal self even after recovery from the clinical depression.
Neurotic depressive patients could be distinguished from unipolar depressive
patients in this regard. The self-concept of the depressive patients was
characterised by means of the bipolar Giessen-test dimensions "insufficiency of
performance", "lack of social adjustment" and "lack of social contact" and by
means of the GT-dimensions "negative social resonance" and "depressive mood".
There were no specific relationships between self-image and parental images in
the depressive sample. The results underline the necessity of therapeutic
interventions in depressive patients during the so-called symptom-free interval.
PMID- 10780157
TI - [Comorbidity of diabetes mellitus and eating disorders. A comparison of
psychological features of eating disordered and non-eating disordered patients
with diabetes mellitus].
AB - As part of a multicentre study on the comorbidity of diabetes mellitus and eating
disorders, the following paper compares the psychological features of diabetic
patients with and without an eating disorder. In a sample of 663 diabetic
patients (type 1: n = 341 type 2: n = 322), eating disorder related variables,
self-esteem, body acceptance and emotional distress, especially depression in
diabetic patients with and without an eating disorder, were compared. A possible
relationship to diabetic control was investigated. Type 2 diabetics revealed more
pronounced psychopathology in comparison to type 1 diabetics. According to our
assumption, diabetic patients with an eating disorder and diabetic patients who
deliberately reduced insulin in order to loose weight (insulin purging) revealed
a much more severe psychopathology compared to diabetics without an eating
disorder. The type of diabetes was of no importance. With the exception of the
variable body and figure satisfaction in the sample of type 1 diabetes and the
variable self-acceptance in the sample of type 2 diabetes, no relationship to
diabetic control could be found.
PMID- 10780158
TI - [What are the physical complaints without pathological clinical signs in patients
with diabetes mellitus?].
AB - In previous research it was found that patients with diabetes mellitus suffer
from multiple physical symptoms even early in their disease course. Such
complaints may relate to blood glucose levels or can be understood as a sign of
distress in respect to the diagnosis of a chronic disease. PURPOSE: This study
was performed to evaluate in a cross-sectional analysis all the symptoms that
patients may complain of and to relate these symptoms to a possible dysfunction
of the autonomic nervous system. METHOD: We assessed the complaints of 66
patients with diabetes mellitus and compared these variables with those of
patients with psychological disturbances (n = 794) or somatic disease (n = 162).
The symptoms were recorded by means of several questionnaires such as the
"Giessener Beschwerdebogen" (GBB), "the Freiburger Personlichkeitsinventar"
(FPI), the German version of the State Trait Anxiety Inventory (STAI) and the
German version of the State Trait Anger Expression Inventory (STAXI). The
autonomic nervous system was assessed using resting and mental stress conditions
in a subset of patients with diabetes mellitus (n = 29) and psychological
disturbances (n = 44). RESULTS: Patients suffering from diabetes mellitus and
psychological disturbances showed a tendency to higher scores in GBB, STAI and
STAXI. As far as psychological disturbances are concerned, the complaints
experienced by patients with diabetes mellitus were found to be similar to those
with somatic diseases. Both groups, however, rate clearly below those with
psychological disturbances. The results of autonomic testing showed a significant
disturbance in patients with diabetes mellitus with reduced sensitivity of the
baroreceptor indicating autonomic neuropathy. CONCLUSION: Some of the physical
complaints of patients with diabetes mellitus can be understood in connection
with autonomic dysfunction. Moreover, an explicitly psychological view of these
complaints may not be correct.
PMID- 10780160
TI - [Religiosity and subjective well-being].
AB - More than 200 studies showed correlations between religiosity and mental health,
which are predominantly positive, but also negative and neutral. A model is
proposed, which refers not only to clinical perspectives, but also to the
sociological research concerning the relationships between religiosity and
subjective well-being (life satisfaction, happiness etc.). This model
conceptualizes subjective well-being as a protective counterpart to mental health
deficits. More specifically, this model describes important processes of
religiously motivated social interaction and intrapsychic regulation of emotions,
and interprets them as interactions between religiosity and subjective well
being.
PMID- 10780161
TI - [Emotional experience, expression and communication in musical improvization. A
qualitative-quantitative single case study].
AB - In this study the theory-conducted empirical procedure for analyzing active
improvisatory music therapy of a single case will be described. The
operationalization and tests for validation will be described. According to the
aim of the study, the results show that the used method is appropriate to
describe different and repetitive (emotional) patterns of improvisatory playing,
which reflect the personal (emotional) and interpersonal pathology and healthy
parts of the examined patient. With the aid of several tests the results of
validating the macro-process will be discussed.
PMID- 10780169
TI - Porcine reproductive and respiratory syndrome virus (PRRSV): kinetics of
infection in lymphatic organs and lung.
AB - Pigs were infected by the oronasal route with European isolates of the porcine
reproductive and respiratory syndrome virus (PRRSV; I10 and Cobbelsdorf). The
kinetics of infection in lymphatic organs and the lung were analysed by
immunofluorescence detection of virus antigen, re-isolation of the virus and
reverse transcription--polymerase chain reaction (RT-PCR) for PRRSV-specific RNA.
The kinetics of PRRSV infection proceeded in three phases, irrespective of the
varying infestation of lymphatic organs within the first days post-infection
(p.i.). First, an early acute infection of lymphatic organs developed within the
first week and was characterized by a high number of antigen-positive
macrophages. Second, a delayed acute infection of the lung was observed, which
was most pronounced during the second and third week p.i. when a high number of
infected alveolar macrophages was observed. The acute infection of lymphatic
organs had resolved at this time. Infected cells in the lung were predominantly
located in pneumonic lesions. Third, a persistent infection was demonstrated by
RT-PCR and immunohistology when the experiments were terminated at day 49 p.i.
The virus persisted in lymphatic organs, especially in the tonsils, and in the
lung. At this stage, indications for a re-occurrence of acute infection were
observed in restricted areas of the lung.
PMID- 10780168
TI - The in vitro secretion of acetylcholinesterase by adult stages of Heligmosomoides
polygyrus: the effects of broad-spectrum anthelmintics.
AB - The secretion of acetylcholinesterase (AChE) by female and male Heligmosomoides
polygyrus was studied in different in vitro culture media. AChE secretion was
increased in the presence of fetal calf serum or bovine serum albumin (BSA). In
the absence of crowding effects, specific AChE activity in excretion/secretion
products was higher for male (2.41 +/- 0.07 mumol min-1 l-1 mg-1) than for female
(0.56 +/- 0.04 mumol min-1 mg-1) worms but on a per nematode basis both sexes
showed comparable rates of secretion. Acetylthiocholine iodide was the favoured
substrate of the enzyme. When the nematodes were incubated in vitro with
albendazole (ABZ), ricobendazole (RBZ), mebendazole (MBZ), levamisole (LVM),
morantel (MRT) or ivermectin (IVM), at concentrations from 1 mM to 10 nM, in RPMI
medium for 2 or 6 h and then transferred to a drug-free medium (RPMI medium
supplemented with 0.5% BSA) for 24 h or continuously exposed to the drugs in
supplement-free medium (24 h), the concentration- and time-dependent inhibitory
effects on AChE secretion were observed. The continued exposure to the drugs for
all incubation periods (with a single exception for LVM 1 mM) produced the
highest levels of inhibition. Under these conditions, the concentrations
inhibiting the secretion of AChE by 50% (IC50) relative to drug-free controls
were estimated. The IC50 values ranged from 0.012 microM (IVM) to 2.96 microM
(MRT). The potential of this bioassay for the selective primary evaluation of new
compounds with broad-spectrum anti-nematodal activity is discussed.
PMID- 10780170
TI - Use of an alkaline phosphatase-labelled probe for the detection of Mycoplasma
synoviae in chickens.
AB - Short nucleotides directly labelled to alkaline phosphatase (SNAP probes) are an
interesting alternative to digoxigenin-labelled probes (DIG probes), because they
reduce the number of steps necessary in dot blots for the detection of DNA or
amplificate. This study examined the questions whether a SNAP probe might not
only save time, but also increase the sensitivity of another PCR-based DNA probe
test using a digoxigenin probe. Amplificates obtained by multispecies polymerase
chain reaction (PCR), with either purified genomic DNA or DNA extracted from
tracheal swabs taken in chicken flocks, were detected by both methods. The
results for the clinical specimens were compared to culture. Under stringent
conditions, the specificity and sensitivity obtained with the SNAP probe were
comparable to the results obtained with the DIG probe. The quantities 10 fg (SNAP
probe) and 100 fg (DIG probe) of purified Mycoplasma synoviae DNA were detected
after amplification, but more positive clinical specimens were detected with the
DIG probe. Under non-stringent conditions sensitivity with purified DNA did no
change, but the coloration of the dots improved markedly, and more positive
specimens could be detected with the SNAP probe than with the DIG probe, truly
positives as confirmed by culture. Because cross-reaction with Mycoplasma
gallisepticum and Mycoplasma imitans, two species with DNA that was also
recognized by the multispecies primers, occurred under non-stringent conditions,
it was concluded that, to take the full advantage of SNAP probes, their use in
combination with species-specific primer pairs is recommended. PCR as a method
for mycoplasma detection is however, always accompanied with serological and
cultural methods. When a M. synoviae mono-infection is likely by serological
results, non-stringent dot blot conditions and use of the SNAP probe will ease
and improve the detection of mycoplasma.
PMID- 10780171
TI - Airborne gram-negative bacterial flora in animal houses.
AB - The concentration and the species composition of airborne gram-negative bacteria
were studied in four cattle houses, one pig house and one poultry barn. On
average only between 0.02 and 5.2% of the total number of culturable aerobic
bacteria were identified as gram-negative bacteria. Obligate anaerobic gram
negative bacteria were not isolated at all. In the airborne gram-negative
bacterial flora the following bacterial families dominated: the
Enterobacteriaceae, the Pseudomonadaceae and the Neisseriaceae. Within the family
of the Enterobacteriaceae the species Escherichia coli and Enterobacter
agglomerans were predominant. In animal houses using straw as bedding material
Ent. agglomerans was most frequent, whereas in animal houses without litter E.
coli was mainly found. Airborne Neisseriaceae were isolated very frequently in
cow barns with Acinetobacter lowffii as the primary species. Airborne
Pseudomonadaceae were found in high concentrations during periods of high air
humidity. The results presented may also give some indications on the origin and
sources of airborne endotoxins in animal housing.
PMID- 10780172
TI - Neospora caninum infection in a clinically healthy calf: parasitological study
and serological follow-up.
AB - In this study a case of congenital infection in a clinically healthy calf is
reported. The mother showed high antibody levels (IFAT) at 230 days of gestation
(IgG titres > or = 1:1600, IgM titres > or = 1:320) and the parasite was isolated
from placental cotyledonary villi at calving. The IgM values are indicative of a
recent infection in the third trimester of gestation. The calf was monitored
serologically for IgM and IgG from birth until slaughtering, at 8 months of age.
IgM titre showed a peak at birth, while IgG peak was observed at 40-60 days of
age. Parasitic isolation was obtained by biological tests using Swiss mice or
VERO cell cultures inoculated with brain and spinal cord tissues. The parasitic
presence in the calf was also evidenced in the myocardium with
immunohistochemical method. The results are very important because they
demonstrate that the period of gestation in which the cow becomes infected is an
important factor in the pathogenesis of N. caninum induced abortion: in fact, the
acquisition of infection in the third trimester of gestation allowed the foetus
to develop a sufficient grade of immunocompetency to limit parasite
multiplication with the result of a calf born clinically healthy.
PMID- 10780173
TI - Abscess disease, caseous lymphadenitis, and pulmonary adenomatosis in imported
sheep.
AB - The occurrence of abscess disease, caseous lymphadenitis, and pulmonary
adenomatosis in sheep in Denmark is reported for the first time. Subcutaneous
abscesses were observed in imported 4- to 5-month-old lambs of the Lacaune breed
10 days after arrival in Denmark. Abscesses were mostly located in the head, neck
and shoulder regions close to the regional lymph nodes. Bacteriological
examinations revealed growth of Staphylococcus aureus ssp. anaerobius in all
animals with subcutaneously located abscesses containing a viscous white-yellow
odourless mass. In addition, Corynebacterium pseudotuberculosis was isolated from
abscesses in one animal and lesions consistent with pulmonary adenomatosis were
found in four animals.
PMID- 10780174
TI - Isolation of Mycoplasma meleagridis from free-ranging birds of prey in Germany.
AB - In this study tracheal swabs and air sac biopsies of 68 raptors of different
species that were found injured or debilitated in Germany were investigated for
the occurrence of mycoplasmas. Mycoplasma meleagridis, Mycoplasma falconis,
Mycoplasma buteonis, Mycoplasma gypis and five mycoplasma isolates not identified
so far could be isolated from 32 (47%) birds. Mycoplasma meleagridis could be
detected in five birds. These birds did not show clinical signs or
histopathological alterations in air sac biopsies related to the infection.
PMID- 10780175
TI - Inactivation of bovine herpesvirus 1 in semen using a hyperimmune egg yolk semen
extender.
AB - Hyperimmune egg yolk semen extender was used for the inactivation of bovine
herpesvirus (BHV-1) in experimentally infected bovine semen. As much as 5 x 10(4)
TCID50/ml of virus was inactivated in semen as assayed by tissue culture.
Moreover the hyperimmune egg yolk semen extender did not produce any adverse
effect on the quality of the semen after being frozen/thawed in comparison with
normal egg yolk semen extender (P > 0.05). The hyperimmune egg yolk semen
extender is considered an important tool for containing the spread of BHV-1 from
infected semen.
PMID- 10780176
TI - [Results of molecular screening of anti-cancer agents. 8. Results of screening of
possible anti-cancer agents in Japan].
PMID- 10780177
TI - [Results of the evaluation of anti-cancer agents by using human cancer cell
panels: details of interpretation].
PMID- 10780178
TI - Prescribing influenza vaccine: for whom?
PMID- 10780180
TI - A skin lesion found by serendipity.
AB - A 77-year-old retired postal worker presented with symptoms of recurrent
aspiration pneumonia, for which he had last been seen one month earlier.
Oropharyngeal dysfunction, presumably caused by previous strokes, was
demonstrated by video-esophagoscopy, and a percutaneous gastrostomy tube was
placed at that time.
PMID- 10780179
TI - Abnormal ECG after a head injury.
PMID- 10780181
TI - Inhaled corticosteroids: 1. Local toxicity.
PMID- 10780182
TI - Making meetings work.
PMID- 10780183
TI - Severe back pain and a history of tuberculosis.
PMID- 10780184
TI - Advances in the approach to acute coronary syndromes.
AB - Acute coronary syndromes is a new term that encompasses the many permutations of
acute ischemic heart disease. Management guidelines can help steer clinicians
through diagnosis and facilitate rational selection of therapy from the myriad of
available treatments.
PMID- 10780185
TI - Treatment of latent and tertiary syphilis.
AB - Although the efficacy of penicillin treatment for syphilis has been amply
demonstrated, the optimal, curative dosage is still undefined. Some patients
experience a third stage of the disease long after secondary-stage symptoms have
resolved. Treatment differs in early and late latency and with the specific
manifestations of tertiary-stage disease.
PMID- 10780186
TI - Controlling cancer pain.
AB - More than a third of patients undergoing therapy for cancer and 60% to 90% of
those with advanced malignancy report significant pain. Effective analgesic
therapy is available, yet large segments of this population--in particular,
elderly patients in nursing homes, minorities, and women--receive inadequate
palliative therapy.
PMID- 10780187
TI - Improving communication with patients.
AB - Aspects of patients' emotional or mental states--such as anger or unspoken
assumptions about health and illness--can complicate management of their physical
illness. Proper communication techniques can help the physician break through
those barriers to medical care and strengthen the therapeutic relationship.
PMID- 10780188
TI - Addressing the dramatic rise in multiple pregnancies.
AB - Practitioners of reproductive medicine have come under scrutiny and criticism
because of the sharp increase in multi-fetal gestations during the past two
decades. Several factors contribute to the problem. However, the negative
consequences of multiple pregnancy are now generally acknowledged, and active
efforts toward a solution are underway.
PMID- 10780190
TI - [Malignant lymphoma. Epidemiologic review of 150 cases].
AB - In the present paper the incidence of lymphomatous disease in Messina and its
province, with growing urbanization and rural limiting areas, is discussed: by
analysing 150 cases of malignant lymphoma observed at our Institute from 1990 to
1995. The method proposed, based on data obtained from the medical files of these
patients, took into consideration various parameters such as age, sex, residence,
profession, clinical and bioptic diagnosis, LDH and disease presentation. The
final results showed an increase of the risk for NHL in the rural province where
the main profession is agriculture or handicraft (ceramics, forged iron,
glasswork, refinery), in subjects above 60 years of age; for the HL instead, over
the years, a minor incidence of risk has been observed. The data obtained were
partially similar to those reported in the international literature. The most
present form in NHL was the lymphocytic and the centrocytic follicular form,
while for HL it was the mixed cells form. The relationship between the two sexes
was higher in males with HL and almost equal in NHL. The age range mostly
affected by HL was between 25 and 65 years of age.
PMID- 10780189
TI - [Elevated levels of lipoprotein(a) are present in subjects with early ischemic
cardiopathy and with a familial history of ischemic cardiopathy].
AB - BACKGROUND: Elevated levels of lipoprotein(a) are associated with a greater risk
of atherothrombotic cardiovascular diseases. Since the Lp(a) levels are
genetically determined and fairly stable in the course of life and a family
history appears to be an independent risk factor of cardiovascular diseases, we
evaluated the behavior of Lp(a) levels in patients with early events of coronary
heart disease (CHD) and also in subjects with positive family history of ischemic
heart diseases. METHODS: The levels of lipoprotein (a) [Lp(a)] were measured in
254 subjects, 138 males and 116 females with an average age of 48.6 +/- 13.8
years (range 20-76 years). Diabetic subjects, females submitted to oestrogen
treatment and those already in treatment with hypolipidaemic drugs were excluded
from the study. Forty of the 254 patients (15.7%), 27 males and 13 females, had
CHD (29 a previous myocardial infarction and 11 a stable angina). A positive
family history for CHD was considered present (102 of the 254 patients) if one or
more first degree relatives had angina or myocardial infarction before the age of
60 years in men and 65 in women. RESULTS: The levels of Lp(a) were higher (p <
0.01) in women (25.1 +/- 28.3 mg/dl) compared to men (17.6 +/- 18.4 mg/dl),
without differences in relation to age. The Lp(a) plasmatic levels were not
correlated with age, body mass index, total cholesterol, LDL and HDL,
triglycerides, apo B, apo AI, fibrinogen and there were no differences in Lp(a)
levels in presence or absence of other known cardiovascular risk factors such as
hypertension and smoking. The Lp(a) levels were not different between subjects
with CHD (28.15 +/- 31.7 mg/dl) and controls (20.3 +/- 22.8 mg/dl). The subjects
with CHD were older and had higher levels of fibrinogen and a significantly
greater prevalence of hypertension and family history of CHD. Fifteen of the 40
subjects with CHD had an early onset of CHD (before 50 years of age) and only in
such patients the Lp(a) levels were significantly greater compared to controls
(35.8 +/- 33.2 mg/dl vs 20.3 +/- 22.8 of the controls, p < 0.01), independently
of other variables (age, BMI, smoking, hypertension, cholesterol, triglycerides,
HDL-c, LDL-c, fibrinogen). Furthermore the Lp(a) plasmatic levels were higher in
subjects with a family history of CHD (28.3 +/- 27.6 mg/dl vs 16.3 +/- 18.6 mg/dl
of the subjects without a family history of CHD, p < 0.01) even if they had or
not had a previous coronary ischemic event. CONCLUSIONS: Such data confirm the
importance of high levels of Lp(a) above all for the early events of CHD and for
the subjects with a family history of CHD, which could be expression of a greater
predisposition for cardiovascular events.
PMID- 10780191
TI - [Indices of disease activity in systemic lupus erythematosus. Review of the
literature].
AB - Systemic lupus erythematosus is a multisystem autoimmune disease characterized by
the production of autoantibodies reacting with many different self antigens. The
analysis of clinical expression and evolution of this disease is a milestone in
the definition of therapeutic strategies. A parameter universally accepted as
gold standard is lacking so far. About 60 indices for defining and measuring the
activity of this disease have been proposed in the last 20 years. The most
important of these are discussed in this review, focusing both on their role in
the evaluation and outcome of patients and on the main studies assessing their
validity and reliability.
PMID- 10780192
TI - A man with worsening weakness.
AB - The contemporary presence of organomegaly, skin manifestations, polyneuropathy,
endocrinopathy and monoclonal component characterises the POEMS syndrome, often
associated with osteosclerotic myeloma and Castelman's disease and more frequent
in the Japanese. Clinical manifestations seem to be related to the production of
many interleukins, mainly IL-1, IL-6 and TNF. Several endocrinopathies have been
described, the most frequent being diabetes. Only one previous case of
hypoparathyroidism associated with the syndrome has been described in medical
reviews. Polyneuropathy is often sensitivo-motory and skin disease accounts for
Raynaud phenomenon, skin pigmentation, hypertricosis and others. We describe the
case of a 74-year-old man who underwent clinical examination for weakness mainly
in the legs. Clinical and instrumental data showed rhabdomyolysis due to
hypoparathyroidism. The contemporary presence of a monoclonal band of light
chains on proteic electrophoresis, organomegaly and distal leg neuropathy allowed
us to make a diagnosis of POEMS syndrome.
PMID- 10780193
TI - [Mirizzi syndrome].
AB - Mirizzi's syndrome is a rare, but well described cause of obstructive jaundice
which occurs in less than 1% of patients presenting for cholecystectomy. The
syndrome is due to a stone impacted in the cystic duct or in the neck of
gallbladder, causing compression or obstruction of the common emphatic duct. The
clinic, physiopathologic, diagnostic and therapeutic aspects of this disease are
described. The patient observed, arrived in emergency with obstructive jaundice
and hyperpyrexia. Echography showed a remarkable dilatation of the biliary ducts,
whereas endoscopic retrograde cholangiography (ERCP) showed an obstruction of the
hepatic common duct of undefinable nature (stone, neoplasia). The surgical
operation performed in emergency made clear the diagnostic doubt. Since
inflammation impacted biliary duct and gallbladder, an incision of the
gallbladder at its fundus was performed. In this way it was possible to extract
about 40 stones of dimensions less than 1 cm, and one of 3 x 1 cm, impacted in
the cystic duct, compressing the common hepatic duct. A partial cholecystectomy
was performed and no connection between gallbladder and common emphatic duct
(fistula) was found. The surgical operation led to complete resolution of the
symptomatology. Therefore, the conclusions is drawn that Mirizzi's syndrome a
rare but non infrequent pathology, finds its definition and complete resolution
with surgical operation. Mirizzi's syndrome or obstructive jaundice due to
extrinsic compression of principal biliary duct by a stone impacted in the cystic
duct, is an uncommon complication of cholecystic lithiasis. Although this
syndrome is rare (1%), it causes obstructive jaundice, sometimes dangerous, and
serious complications as recurrent cholangitis.
PMID- 10780194
TI - [Changes caused by mineral water on gastrointestinal motility in patients with
chronic idiopathic dyspepsia].
AB - BACKGROUND: The antidyspeptic property of mineral waters has been based for ages
on empirical data. In the present paper the effects of one of them (Tettuccio,
Montecatini) on gastrointestinal motility of patients with dyspepsia has been
evaluated. METHODS: The study was carried out on 24 patients with idiopathic
dyspepsia and delayed gastric emptying at scintigraphy and 18 healthy subjects
with normal gastric emptying. The gastric emptying of this mineral water was
studied with a scintigraphic method in comparison with tap water, while its
effects on gastroduodenal contractions were evaluated by of manometry. RESULTS:
The gastric emptying of this mineral water was significantly faster than that of
tap water, both in dyspeptic patients and in normals. Manometric examination
showed that the administration of mineral water induced a brief decrease of
phasic motor activity, followed by a progressive increase, which in some cases
ended in an activity front of the Migrating Motor Complex. CONCLUSIONS: This
mineral water has a stimulating effect on both gastric emptying and
interdigestive cyclic motor activity of the gastroduodenal tract. Both these
effects could be useful in the treatment of chronic idiopathic dyspepsia and
impaired gut clearing.
PMID- 10780195
TI - [Acquired angioneurotic edema. Clinical and biological characteristics in 9
patients].
AB - OBJECTIVE: Angioneurotic edema (AE) is a rare but severe disease. Hereditary AE
is the more well-known form. The acquired form is exceptional: the symptoms are
the same but there are some biologic and treatment differences. We investigated
the clinical and biochemical features in nine patients with acquired
angioneurotic edema (AAE). PATIENTS AND METHODS: Four of the patients with type I
AAE presented an accelerated metabolism of C1Inh, associated with a hematology
disease. Their C4, C1q and C1Inh plasma levels were low. Four patients had type
II AAE associated with an autoantibody to C1Inh. Their C1Inh plasma levels were
normal or low but the functional levels were low in all four. One patient had AAE
induced by oral contraceptives. The C1Inh plasma level was normal but the
functional level was very low; there were no autoantibodies. Symptoms resolved
when oral contraceptives were withdrawn and the C1Inh level returned to normal.
DISCUSSION: Treatment of AAE is a difficult matter. For type I AAE, it consists
in treating the associated disease. For type II AAE, the treatment goal is to
lower the autoantibody level. Management of these diseases requires close
collaboration between clinicians and biologists.
PMID- 10780197
TI - [Drug hypersensitivity syndrome to valproic acid].
AB - BACKGROUND: Drug-induced hypersensitivity syndrome is an uncommon but potentially
life-threatening idiosyncratic drug reaction. It is usually due to aromatic anti
convulsants. We report the second case induced by sodium valproate, a non
aromatic anticonvulsant. CASE REPORT: A 28-year-old woman was treated with sodium
valproate for 5 weeks. She suddenly developed a generalized maculo-papulous
eruption with fever, node enlargement, hypereosinophilia and altered liver
function. DISCUSSION: Drug-induced hypersensitivity is rarely induced by valproic
acid. The time-course and positive patch tests using the diluted drug establish
the diagnosis.
PMID- 10780196
TI - [Bepridil: importance of serum level in treatment surveillance].
AB - OBJECTIVE: Despite precise recommendations for prescription and monitoring,
tosades de pointes is still observed with bepridil. The purpose of this study was
to demonstrate the contribution of bepridil serum assay in therapeutic
supervision. PATIENTS AND METHODS: Seventy-five patients over 70 years of age
were included. Prolongation of the QT interval was observed in 23 patients.
RESULTS: The potential prognostic factors for increased QT interval as
demonstrated by univariate logistic regression were hypokaliemia, bradycardia,
renal failure and bepridil serum level. After multivariate logistic regression,
the persisting causal factors for increased QT interval were hypokaliemia,
bradycardia and bepridil serum level. CONCLUSION: Prolongation of the QT interval
remains dependent on several variables. Bepridil determination during treatment
is insufficient alone.
PMID- 10780198
TI - [Leiomyosarcoma of Meckel's diverticulum in cystic form].
AB - BACKGROUND: Leiomyosarcoma is an uncommon small bowel tumor. About 60 cases of a
Meckel's diverticulum localization have been reported. We present a very rare
form of leiomyosarcoma arising in a Meckel's diverticulum, mimicking a very large
abdominal cyst. CASE REPORT: Abdominal ultrasound evidenced a voluminous cystic
mass in the abdomen of a 37-year-old man consulting for abdominal discomfort.
Computed tomography visualized a tissular component with contrast uptake.
Laparotomy was performed with resection of a 4 liter cyst on the Meckel's
diverticulum. Histology reported leiomyosarcoma. DISCUSSION: Leiomyosarcoma of
the small bowel mainly develops in an extraluminal localization. Necrotic
remodeling explains the cyst formation. Computed tomography with contrast
injection can be most helpful for diagnosis. Surgery provides the only possible
cure in still localized forms. Other treatments have failed to demonstrate any
benefit. Prognosis is mainly related to the histological grading according to the
mitotic index.
PMID- 10780199
TI - [Hydatid cyst of the gluteal muscle. Apropos of a case].
PMID- 10780200
TI - [Auriculo-ventricular arrhythmia due to carboplatin].
PMID- 10780201
TI - [Recurrent facial nerve paralysis in hereditary neuropathy with liability to
pressure palsy].
PMID- 10780202
TI - [Peritoneal infections: preventive effect of perioperative supplemental oxygen
administration].
PMID- 10780203
TI - [Frequency and costs of hospital stays for hypoglycemia in France in 1995].
AB - OBJECTIVES: Diabetes is a highly prevalent chronic disease causing serious
complications. Hypoglycemia is the most frequent, the most serious, and the most
feared by patients and families. Hospitalization may be necessary and can be
costly. The main objective of this study was to determine the number of cases of
hypoglycemia cared for annually in France in an inpatient setting and to estimate
the annual financial impact of hospitalizations. PATIENTS AND METHODS: The number
of hypoglycemias seen annually by physician s in France and the frequencies of
hospitalizations for hypoglycemia were determined from a literature search.
Complementary data on costs were obtained from the national PMSI mission. Our
sample included 817 hospital stays between 1994 and 1995. RESULTS: In 1992,
physicians in France cared for 40,000 episodes of hypoglycemia. There were 10,800
hospitalizations. In 9 out of 10 cases, the hospital stay lasted several days
and, despite hospitalization, 1.9% of the patients died. Mean total medical cost
of a hospital stay for hypoglycemia was 14,000 FF ($2,100) (median 10,000 FF,
range 1,200-120,000 FF). Mean length of stay was 6.6 days. DISCUSSION: Mean unit
cost for hospital stays for hypoglycemia is high. Based on the 1993 SESI survey,
the probable annual cost for the society for hospital care of patients with
hypoglycemia was an estimated 108 to 151 million FF ($16-22 million) in 1995.
This figure only takes into account the visible cost of caring for hypoglycemia
patients. Ambulatory care was not taken into consideration. Education, for the
patient and family, is fundamental for the prevention and treatment of
hypoglycemia. CONCLUSION: It is important to have this estimation due to the
absence of a medicoeconomic study on ambulatory and hospital care for
hypoglycemia. Complementary studies should be conducted to estimate the total
annual cost of hypoglycemia in France.
PMID- 10780204
TI - [Hypocalcemia of hypomagnesemia: parathyroid deficiency rather tha parathyroid
resistance].
PMID- 10780205
TI - [Apropos of rubella in pregnancy].
PMID- 10780206
TI - [Fetal pain].
AB - IN UTERO CARE: The definition of pain proposed by the International Association
for the Study of Pain is not adapted to the newborn or to the fetus because it
assumes recognition and verbal expression of an unpleasant experience.
Neonatologists have however demonstrated that full term and highly premature
infants experience pain. In addition, the health of these infants improves with
proper management. Such an approach is indispensable, not only from an obvious
humane point of view, but also because treatment of pain in utero could have a
beneficial effect for the fetus. PRENATAL PAIN AND ITS CONSEQUENCES: As it is
impossible to resolve the question of conscious perception of pain by the fetus,
we use experimental or clinical arguments favoring sensitivity to pain to assess
pain during fetal life. We have also investigated the deleterious consequences of
antenatal pain and how to evaluate them clinically in order to propose
therapeutic care. It can be accepted that the fetus is able to perceive pain as
early as 26 weeks gestation, possibly from 20 weeks. In the short-term, fetal
pain causes changes in behavior, hemodynamics and hormonal functions but the long
term consequences remain unknown. ANTENATAL ANALGESIA: As no validated data on
assessment of pain in the fetus are available, prevention becomes primordial in
all at risk situations (pregnancy termination beyond 24 weeks gestation, in utero
interventions). Morphine derivatives (sufentanil) would be the analgesic of
choice for antenatal pain.
PMID- 10780207
TI - [Causal interactions of estrogens and alcohol in cancer of the breast].
AB - BACKGROUND: The majority of studies and meta-analyses tend to show a very slight
increase of risk of beast cancer in post-menopausal women receiving hormone
replacement therapy (HRT). Such results must however be interpreted in light of
biases including intensive follow-up in women taking HRT and unknown or new
parameters. DATA: Several publications have demonstrated an increased relative
risk of breast cancer in women consuming alcohol. This increase rises linearly
with the level of alcohol intake. To date, this parameter has been neglected in
post-menopausal women taking HRT. Two studies have demonstrated a rise in breast
cancer in women taking HRT who drink alcohol. No particular explanation is put
forward. INTERPRETATION: Based on an experimental human study, E. Ginsburg has
shown that there is a considerable and long-duration increase in estradiolemia in
women on HRT who also drink alcohol. This hyperestradiolemia could exceed the
promotion threshold of breast carcinogenesis. This new parameter must be taken
into consideration as effective preventive measures can be implemented:
convincing women taking HRT to limit their alcohol intake.
PMID- 10780208
TI - [The role of drugs in falls in the elderly. Epidemiologic aspects].
AB - FALLS AND POST-FALL SYNDROME: Falls are a major health problem among the elderly
because of the resulting psychological sequelae (sometimes termed "post-fall
syndrome") and in a few cases serious injury, particularly hip fractures. DRUGS
AND FALLS: The scientific literature on the link between medications and falls
and fractures suggests that psychotropic drugs used in about 50% of residents of
nursing homes and in 20% in the community cause around 30% of falls in nursing
homes and 20% of falls in the community. PSYCHOTROPS: The relative effect of
selective serotonin reuptake inhibitors and tricyclic antidepressors and the
relative effect of short/long acting or sedative/hypnotic benzodiazepines are not
well established. CARDIOVASCULAR DRUGS: Appropriate use of cardiovascular
medications and analgesics does not increase the risk of falls. PREVENTION: These
data reinforce the concept that reducing the use of psychotrops, especially
benzodiazepines, is probably one of the most effective means of reducing serious
falls in older people.
PMID- 10780209
TI - [What possible treatments for liver cirrhosis patients with a small
hepatocellular carcinoma?].
AB - UNDERLYING LIVER DISEASE: Most cases of hepatocellular carcinoma (HCC) develop in
subjects with an underlying chronic liver disease, primarily hepatitis C
infection. The underlying liver disease greatly limits treatment possibilities
due to the restrictions on surgery or the risk of recurrence even when surgical
resection, chemoembolization or alcoholization appears to be successful. IN CASE
OF NORMAL LIVER FUNCTION: Percutaneous destruction of the tumor with
alcoholization or radiofrequency techniques can be effective against HCC tumors
measuring less than 3 cm. Access is however sometimes limited, leading to partial
destruction and risk of local recurrence. When the patient's liver functions are
compatible with surgery, resection of the tumor and its adjacent portal segment
has been found to be effective against tumors measuring 3 to 5 cm.
TRANSPLANTATION: Liver transplantation is by far the most effective treatment for
HCC, treating both the carcinoma and the underlying liver disease. Indications
are however limited to patients with at most 3 tumors measuring less than 3 cm
with no portal involvement and who can be expected to tolerate the major surgery.
In addition, the absence of tumoral extension while waiting for transplantation
is an important factor.
PMID- 10780210
TI - [Fractal geometry: its possible applications to radiologic imaging].
PMID- 10780211
TI - [Dentascan computed tomography of the mandibular incisive canal. Its radiologic
anatomy and the therapeutic implications].
AB - PURPOSE: To stress the importance of CT depiction of the mandibular incisive
canal. This anatomical structure contains a major neurovascular bundle and is
thus very important in the planning of mandibular implants in the canine-incisive
area. MATERIALS AND METHODS: January through December 1998, sixty patients
unselected by age and gender were submitted to mandibular CT. Axial slices were
acquired with 1-1.5 mm thickness and 1 mm table feed, and the images were then
reformatted with a dedicated dental software. Both the conventional and the
Helical techniques were used. RESULTS: The incisive canal appears on Dentascan
transverse reconstructions as a round low-density area within mandibular
trabecular bone, which is surrounded by a higher-density rim representing the
canal walls. This anatomical structure originates from the mental foramen and
continues mesially to the mental symphysis. The mandibular canal was visualized
in 95% of cases bilaterally (57/60); the incisive canal was depicted on the left
side in 41.6% of cases (25/60) and on the right side in 51.6% (31/60).
CONCLUSIONS: The importance of careful assessment of the mandibular canal course
before implantology is now widely recognized. The same holds true for the canine
incisive region in the jaw, to detect the incisive canal if present and prevent
any complications from its accidental damage. CT with a dedicated software showed
the incisive canal in a large number of patients, which calls for precise
reporting of its presence, course, and relationships with teeth.
PMID- 10780212
TI - [Breast carcinoma diagnosed in mammographic screening incidentally. Research on
the radiologic signs in prior mammograms].
AB - PURPOSE: To determine how many cancers screen-detected at subsequent rounds were
already visible on previous screening mammograms, and to study their radiological
features. MATERIALS AND METHODS: The previous screening mammograms of 100 women
who had cancers screen-detected at subsequent rounds (group A), and the negative
screening mammograms of 200 women (group B) who had a further negative screening
test two years later, were mixed for a new reading. The two groups were similar
for age and year of examination. These films were blindly reviewed by 5
radiologists. Then, mammograms were reviewed retrospectively, with knowledge of
subsequent diagnostic results. Finally the A group findings were classified as:
1) true negative: no radiological signs; 2) minimal sign: a nonspecific
abnormality is retrospectively visible at the site of subsequent cancer; 3) false
negative: "she should have been recalled"; 4) misdiagnosis at assessment: the
woman had been recalled, but the cancer was missed after the assessment
procedures. RESULTS: 60% of cases were true negatives, 29% were minimal signs, 9%
were false negative and 2% were misdiagnosed at assessment. The most common
radiological sign found among false negative cases was an architectural
distortion: opacities and calcifications were more frequent among minimal signs.
Only 10 of 40 cancers retrospectively visible on previous mammograms had reached
stage II at diagnosis. At blinded review, the radiologists found false
abnormalities in a considerable number of healthy women (average: 29%).
DISCUSSION AND CONCLUSIONS: Our study shows that mammography sensitivity can be
improved. Cancer radiological signs may go undetected due to difficult
interpretation (opacities, calcifications) or perception (architectural
distortions). The use of a low threshold of suspicion (as in a reading test) in
real screening might permit to detect more cancers (most of them, however, would
not reach advanced stages at subsequent rounds), but might also lead to many
unnecessary assessments and, probably, to some benign biopsies in healthy women.
In conclusion, an attempt at improving mammography sensitivity by lowering the
threshold of suspicion can not be directly recommended due to the considerable
negative effects related to a loss in specificity. A reading test similar to the
one presented in our study would be a useful training procedure for radiologists
who are involved in a screening program.
PMID- 10780213
TI - [Breast calcifications. The usefulness of a standardized system for the
description and assessment of the mammographic findings to improve the positive
predictive value].
AB - PURPOSE: To investigate the usefulness of a standardized reporting and data
system in improving the positive predictive value of mammography in breast
calcifications. MATERIALS AND METHODS: Using the Breast Imaging Reporting and
Data System lexicon developed by the American College of Radiology, we defined 5
descriptive categories of breast calcifications and classified diagnostic
suspicion of malignancy on a 3-grade scale (low, intermediate and high). Two
radiologists reviewed 117 mammographic studies selected from those of the
patients submitted to surgical biopsy for mammographically detected
calcifications from January 1993 to December 1997, and classified them according
to the above criteria. The positive predictive value was calculated for all
examinations and for the stratified groups. RESULTS: Thirty-five of 36 cases
classified as low-grade suspicion at mammography were benign at histology, while
the extant one was a microinvasive lobular carcinoma in situ. Of 44 cases of
intermediate-grade suspicion, 21 were benign while 23 were malignant lesions. All
the 37 cases graded as highly suspicious were actually carcinomas. The positive
predictive value was 0.52 for the whole series, 0.02 in the low suspicion group,
0.52 in the intermediate suspicion group and finally 1.0 in the high suspicion
group. If the low suspicion cases had not undergone surgical biopsy, the positive
predictive value would have been 0.74, with a single false-negative. DISCUSSION
AND CONCLUSION: Defining a standardized system for assessing and describing
breast calcifications helps improve the diagnostic accuracy of mammography in
clinical practice.
PMID- 10780214
TI - [The prognostic significance of 99mTc-MDP breast scintigraphy. A comparison with
histological and molecular parameters].
AB - INTRODUCTION: Breast scintigraphy (BS) with the bone-seeking agent 99mTc
medronate (MDP) can be usefully combined with mammography to diagnose and
characterize questionable breast lumps. However this radiotracer does not seem to
provide any further prognostic information about breast cancer. Therefore we
investigated the prognostic yield of MDP-BS searching for correlations between
scintigraphic findings and the major biological and histologic parameters.
MATERIALS AND METHODS: We retrospectively analyzed a series of 44 primary breast
cancers. All patients had undergone 99mTc-MDP bone scan for preoperative staging,
as well as conventional breast imaging. We statistically compared the
cancer/background ratio (c/b index) with lesion histotype, diameter, grading, and
the tissue concentrations of steroid receptors, cathepsine D, type 1 timidine
kinase, pS2 and p53 proteins. RESULTS: MDP-BS failed to depict 11 of 44 lesions
(O 0.5-2 cm), detected 7 of 16 mammographically questionable lesions and
correctly visualized the two multifocal cases. Also, MDP-BS depicted no
metastatic axillary lymph nodes. We found no statistically significant
correlation between the c/b index and the prognostic markers. DISCUSSION AND
CONCLUSIONS: Differently from BS with 99mTc-MIBI, 201T1, 18F-FDG, 111In-OCT and
radiolabeled estrogens and despite its good overall accuracy, MDP-BS appears to
have no prognostic role. In fact, despite the well-known capability of soft
tissue lesions to take up the tracer, MDP tumor trapping seems to depend mainly
on the increased permeability of neovessels and on interstitial space
enlargement. Few reports are available in the literature on the correlation
between in vivo MDP uptake by the breast cancer and prognostic parameters. Thus,
we tested possible correlations between the amount of MDP taken up by the breast
cancer, histologic features and cell concentrations of some major biomarkers. The
lack of any statistical significance is in agreement with the theory, and
confirms the little prognostic value of MDP-BS. Nevertheless, further trials are
warranted on larger series of cases to validate our personal findings.
PMID- 10780215
TI - [The role of computed tomography in gunshot lesions of the chest. The authors'
personal experience].
AB - PURPOSE: CT is a valuable tool in assessing thoracic gunshot wounds. CT is also
the method of choice in emergency, because it permits rapid depiction of bullet
damage to the chest and to other body districts. This in turn permits correct
assessment of the main thoracic injuries, plus adequate and prompt planning of
surgical treatment or support intensive care. We report on the role of CT in
diagnosing the complex pleuropulmonary, cardiovascular and thoracic wall injuries
caused by gunshot wounds, with their specific and acute signs which differ
greatly from those of other types of chest trauma. MATERIAL AND METHODS: In the
last 4 years, we observed 76 cases of gunshot injury, twenty-six of them involved
the chest. The patients, 25 men and 1 woman (mean age: 32 years, range: 17-48),
were all submitted to emergency CT with i.v. contrast agent injection and the CT
angiography technique. The reanimator was always present to monitor the patients'
vital functions and shock state. CT of the chest was integrated with CT of the
abdomen and pelvis in 4 cases and with CT of the skull in 3 cases, to detect
associated bullet wounds if any. RESULTS: The most frequent CT finding was lung
parenchyma tear and bruise (25 cases), followed by hemothorax (18 cases) and
subcutaneous chest wall emphysema (9 cases). Pneumothorax was seen in 5 cases,
associated with hemothorax in 6; rib injuries were found in 7 cases;
pneumomediastinum was found in 4 cases and areas of pulmonary atelectasis in 3;
the diaphragm was ruptured in 4 cases. CT showed spinal involvement in 11
patients, with injury of D3 and D5 in 4 and 3 cases, respectively; signs of
interrupted spinal marrow were found in 7 cases. Damage from gunshot wounds was
detected in the liver, spleen, skull and limbs in 3, 2, 3 and 10 cases,
respectively. DISCUSSION AND CONCLUSIONS: Chest radiography shows major gunshot
wound damage to the chest and lungs, except for heart injuries and minimal
pneumothorax. When abdominal and skull injuries are associated, CT should be the
method of choice because it permits prompt and panoramic assessment of the
severity of pulmonary and extrathoracic damage. This results in prompt and
targeted treatment, avoiding unnecessary delays which may damage the patient
further.
PMID- 10780216
TI - [3-dimensional magnetic resonance angiography in apnea with the rapid infusion of
a paramagnetic contrast medium in studying the thoracic aorta].
AB - INTRODUCTION: We investigated the diagnostic accuracy of gadolinium-enhanced 3D
MRA in the assessment of thoracic aortic diseases. MATERIAL AND METHODS: Thirty
eight patients with diagnosed or suspected conditions of thoracic aorta were
examined with contrast-enhanced MRA. All the examinations were performed with a
1.5 T superconductive magnet acquiring breath-hold 3D fast Gradient-Echo (GE)
sequences (TR = 5.9 ms; TE = 1.2 ms; FA = 45 degrees; FOV = 48 cm; thickness = 2
2.5 mm; locs = 30-32; TA = 22-24 s; MA = 512) on the coronal plane. The contrast
agent was injected bolus after a bolus-test to evaluate circulation time.
RESULTS: Three-dimensional gadolinium-enhanced MRA permitted to correctly
diagnose aneurysm in 18 patients, dissection in 13 patients and coarctation in 3
patients. In the former the size and extent of the aneurysmal lumen and its
relationship to aortic side branches was demonstrated. As for dissections we
evaluated the following parameters: 1) type; 2) presence of intimal flap; 3)
thrombosis of the false lumen; 4) dilatation of the aorta; 5) assessment of great
vessel origins. MRA data were correlated with those of biplane transesophageal
esophageal echocardiography, conventional MRI and spiral CT. In the three
patients with aortic coarctation the site of coarctation was correctly
identified, the degree of aortic narrowing evaluated and the collateral vessels
demonstrated. CONCLUSIONS: In our opinion contrast-enhanced three-dimensional MR
angiography should be the screening technique of choice in the evaluation of
thoracic aorta thanks to its low invasiveness, short acquisition time, large
field of view and morphologic resolution. ECG gating is not needed. Limitations
are found in the study of wall and periaortic region which are better evaluated
with conventional MR imaging.
PMID- 10780217
TI - [Defecography by spiral computed tomography].
AB - PURPOSE: We investigated the possible role of helical CT defecography in pelvic
floor disorders by comparing our results with those of conventional defecography.
MATERIAL AND METHODS: Our series consisted of 90 patients, namely 62 women and 28
men, ranging in age 24-82 years. They were all submitted to conventional
defecography, and 18 questionable cases were also studied with helical CT
defecography. The conventional examination was performed during the 4 standard
phases of resting, squeezing, Valsalva and straining; we used a remote-control
unit. The parameters for helical CT defecography were: 5 mm beam collimation,
pitch 2, 120 KV, 250 mAs and 18-20 degrees gantry inclination to acquire coronal
images of the pelvic floor. The rectal ampulla was distended with a bolus of 300
mL nonionic iodinated contrast agent (dilution: 3 g/cc). The patient wore a
napkin and was seated on the table, except for those who could not hold the
position and were thus examined supine. Twenty-second helical scans were
performed at rest and during evacuation; multiplanar reconstructions were
obtained especially on the sagittal plane for comparison with conventional
defecographic images. RESULTS: An unquestionable diagnosis could be made in all
the 18 patients submitted to helical CT defecography. The diagnosis was in
agreement with proctology results and added new information in all cases. Sixteen
patients had constipation and 2 fecal incontinence--one from rectal prolapse and
the other from a rectovaginal fistula. In this latter case helical CT
defecography permitted to confirm the fistula and suggest its course. One patient
had a previously undetected ovarian cancer metastatic to the anterior rectal
wall. DISCUSSION AND CONCLUSIONS: Coronal helical CT defecography images
permitted to map the perineal floor muscles, while sagittal reconstructions
provided information on the ampulla and the levator ani. To conclude, helical CT
defecography performed well in the study of pelvic floor disorders and can follow
conventional defecography especially in questionable cases.
PMID- 10780218
TI - [The assessment of chronic pancreatitis by magnetic resonance and MR
cholangiopancreatography. II. The semeiotics and results].
PMID- 10780219
TI - [Endovascular treatment in diseases of the thoracic aorta].
AB - PURPOSE: To determine whether endovascular treatment of thoracic aorta conditions
can be an effective alternative approach to surgical repair. MATERIAL AND
METHODS: July 1997 to February 1999, eighteen patients (16 men and 2 women; 58.6
+/- 14.8 years) presenting with different kinds of descending aorta conditions
were selected for the endovascular treatment. All patients exhibited severe
comorbid pulmonary and/or cardiovascular medical conditions which increased
surgical risk. All implants were performed in the operating room under
fluoroscopic and TEE guidance. Clinical and imaging follow-up was performed 1, 3,
6 and 12 months later. RESULTS: The endovascular treatment was successful in 17
cases. No deaths or major complications occurred. No leakage was evident at post
procedure angiography. The patients were discharged after 6 +/- 4 days. MRI or CT
study performed before hospital discharge showed aneurysms exclusion in 16
patients. In the four cases of dissection, thrombosis of the false lumen was
evident since the first follow-up study. In the group of patients (11 cases) with
6 months follow-up, the diameters of stented aortic segments decreased. No late
leakage was observed and thrombosis was complete in all cases. DISCUSSION: The
natural history of aortic aneurysms and dissection is progressive toward dilation
and aortic rupture. Surgery of descending thoracic aorta is burdened with a
mortality of 8-12% in elective cases and over 50% in emergency cases or aortic
dissection. The endovascular treatment of aortic conditions was introduced in
clinical practice in 1991 and literature data show that it is effective, with
lower mortality and morbidity rates than surgical treatment. CONCLUSION: Our
results stress the feasibility and effectiveness of endovascular procedure in the
treatment of complex thoracic aorta conditions even in high risk patients. Thus,
endovascular treatment of thoracic aorta can be considered an effective
alternative approach to conventional surgery.
PMID- 10780220
TI - [Echo-guided percutaneous treatment of chronic calcific tendinitis of the
shoulder].
AB - PURPOSE: We report on our personal technique and the results of US-guided
percutaneous treatment of chronic calcific tendinitis. MATERIAL AND METHODS:
January 1997 to March 1999, seventy patients with known chronic calcific
supraspinatus tendinitis were submitted to the US-guided treatment. All patients
had undergone plain radiography, US, and physical and psychiatric examination.
Plain radiography and aspiration biopsy demonstrated hard and radiopaque
calcification in 59 patients and soft and faintly milky calcification in 11
cases; calcification diameter ranged 6-30 mm. US showed tendon thickening, with
bulging of the outer tendon surface; 10 patients also had moderate dilatation of
the subacromial bursa. Psychiatric examination revealed chronic pain exacerbated
at night, which was always associated with motion impairment. The selection
criteria for treatment were calcification diameter > 6 mm, integrity of the
tendon, and chronic pain. After superficial planes were anesthetized, a 16 G
needle was positioned inside the calcification under US guidance and the calcific
deposits were fragmented and aspirated. Then, 0.5-1 mL triamcinolone acetonide
(40 mg) was injected in the soft tissues or subacromial bursa. RESULTS: Pain
resolution and recovery of the full range of motion were seen in 42 patients
(60%), and mild functional impairment was seen in 7 cases (10%), while 2 patients
(2%) were unchanged. Post-treatment plain radiography showed calcification
disappearance in 41 patients (58.5%) and debulking in 29 (41.5%); the
calcifications were significantly debulked (> 60%) in 27 patients (38.5%).
However, calcification diameter was substantially unchanged in 2 patients (3%)
and there remained tendon bulging; in these patients clinical symptoms did not
improve. No rotator cuff tears or new tendon calcifications were found in any of
our patients even at 19-28 months' follow-up. DISCUSSION: The US-guided technique
always allowed easy location of calcific deposits and complete aspiration of all
soft calcifications. Splintering of hard calcifications helped migration of
residual deposits to vascularized soft tissues, which accelerated the--frequently
complete--resorption process. We privileged extensive and prolonged fragmentation
of the calcifications using a single needle, versus the technique using a second
needle, saline lavage and aspiration of residual deposits. CONCLUSION: US-guided
percutaneous treatment with aspiration and splintering of chronic calcific
supraspinatus tendinitis is a conservative, simple, well-tolerated procedure
which can be considered the method of choice after the failure of medical
treatment.
PMID- 10780221
TI - [The percutaneous drainage of prostatic abscesses in the dog].
AB - INTRODUCTION: Prostatic abscesses are an uncommon finding in the dog; they are
most frequently seen in dogs over six years old, often in association with benign
hyperplasia. Ultrasonography (US) is an essential technique to study prostatic
conditions in the dog, because the particular anatomical site of this gland in
the dog makes rectal palpation insufficient to assess even macroscopic changes.
Presently, US-guided drainage makes a particularly efficient tool for treatment
of this condition in these patients. We report on our personal technique of
percutaneous drainage of prostatic abscesses in the dog. MATERIAL AND METHODS:
Forty-five dogs of different breeds and age were examined. Some of them were
given short anesthesia or mild sedation for restraining purposes, although this
procedure is painless and could be performed under local anesthesia like in human
patients. In man, the approach is perineal, but in the dog it is best to use an
abdominal approach with right or left inguinal positions. US is necessary for
correct drainage of the abscess and for monitoring throughout the procedure.
DISCUSSION AND CONCLUSION: US-guided percutaneous drainage of prostatic abscesses
in the dog proved to be a safe and quick tool providing excellent results. No
patients exhibited any postoperative complication and we had as little as 10%
relapses at 30 days. The following drainage with alcoholization of the abscessual
cavity resolved the conditions definitively. This technique was particularly
interesting for both its success rate and the lack of postoperative
complications, which are usually quite common after conventional surgery.
PMID- 10780222
TI - [The relationships between the general practitioner and the oncological
radiotherapist. A preliminary study by telephone interviews].
AB - PURPOSE: We addressed the issue of the relationship between the general
practitioner (GP) and the radiotherapist to improve the quality of care of cancer
patients. MATERIAL AND METHODS: The study consisted in evaluating medical
requests and phone interviews, with a questionnaire with yes/no and multiple
choice answers to the following 5 questions: 1) Do you think a cancer diagnosis
is always a hopeless death sentence? 2) Is it professionally rewarding to cure a
cancer patient? 3) Are you satisfied with your relationship, as a general
practitioner, with oncologic reference centers? 4) Is it more wearing for a
general practitioner to manage a cancer than a noncancer patient? 5) Would you
answer a questionnaire about the relationship between the general practitioner,
the cancer patient and the oncologist? We evaluated 1590 medical requests and
made 401 phone interviews; 255 colleagues (70%) answered the questionnaire.
RESULTS: Medical requests were correctly and completely formulated by GPs in 45%
of cases. A cancer diagnosis was not considered a hopeless death sentence in
90.9% of cases and 76% of GPs considered it professionally rewarding to cure a
cancer patient. 75.6% of GPs considered it more wearing to manage a cancer than a
noncancer patient, and female GPs felt this more strongly than their male
counterparts. Irrespective of gender, GPs over 50 years of age tend to consider
cancer a hopeless and fatal disease. The relationship with oncologic centers was
considered satisfactory in 86.2% of cases. However, since cancer patients need
greater medical care, GPs would like a closer cooperation with oncologists.
DISCUSSION AND CONCLUSIONS: The great interest GPs took in this study encourages
further investigation through a more in depth questionnaire designed with the
help of GPs themselves and interested statisticians.
PMID- 10780223
TI - [A neonatal sacrococcygeal teratoma studied by spiral computed tomography. A case
report].
PMID- 10780224
TI - [The Poland syndrome. A case study with magnetic resonance, radiology, echography
and color Doppler].
PMID- 10780225
TI - [Mazabraud's syndrome. A case report].
PMID- 10780226
TI - [The Noonan syndrome and malformation of the inner ear. A case study by the
steady-state MR technic].
PMID- 10780227
TI - [Langerhans-cell histiocytosis of the otomastoid area. A case report].
PMID- 10780228
TI - [Cerebrotendinous xanthogranulomatosis. Apropos a case].
PMID- 10780229
TI - [Central pontine myelinolysis. Apropos a case].
PMID- 10780230
TI - [Schistosomiasis of the spinal cord. The MR aspects in a case].
PMID- 10780231
TI - [A ruptured aneurysm of the bronchial artery. A report of a case studied by
spiral computed tomography and a review of the literature].
PMID- 10780232
TI - [Idiopathic intestinal pseudo-obstruction of the colon. A case report].
PMID- 10780233
TI - [A case of a teratocarcinoma with retroperitoneal location].
PMID- 10780234
TI - [Hydrospermatocyst with ectopic insertion of the ureter associated with
homolateral renal agenesis. A magnetic resonance case study].
PMID- 10780235
TI - [Adrenal hydatidosis. The computed tomographic picture in a case].
PMID- 10780236
TI - [Crazy paving].
PMID- 10780237
TI - [Pulling ears].
PMID- 10780238
TI - [Cannibalism or pedantry?].
PMID- 10780240
TI - The effects of morphine on clocked fixed-interval performance: stimulus function
or strength of stimulus control?
AB - The present experiment was conducted to determine whether the modification of the
effects of morphine by food deprivation would occur under conditions of strong
stimulus control. Four pigeons pecked response keys under a multiple fixed
interval (FI) 5-min and clocked fixed-interval (CFI) 5-min schedule of food
presentation. During the FI component, the key was lit green and the house light
was on throughout. During the CFI component, the key light and house light
settings changed in a regular manner as the interval elapsed. In all conditions,
pigeons received a range of doses of morphine (1.0-10.0 mg/kg) and saline. In the
first condition, pigeons were maintained at 80% of their free-feeding weights.
When calculated over entire 5-min intervals, morphine produced dose-dependent
decreases in the index of curvature (a measure of temporal patterning) during the
FI component, but did not affect the index of curvature during the CFI component.
A more detailed analysis revealed that the index of curvature during the last
stimulus in the CFI sequence was reduced in a dose-dependent manner, similar to
the effects obtained for the entire FI component. When the pigeons were
maintained at 70% and 90% of their free-feeding weights, measures of the effects
of morphine on temporal patterning did not differ as a function of body weight.
The effects of morphine on rates of key-pecking, however, were related to body
weight. For three of four pigeons, rates of key-pecking were not suppressed until
higher doses, and increases in rates of key-pecking were more common at lower
doses, when the pigeons were maintained at 70% of their free-feeding weights,
than when they were maintained at 90% of their free-feeding weights. It is
suggested that the effects of morphine on CFI performance can be understood in
terms of the function of the stimuli that comprise the schedule, rather than the
strength of the stimulus control engendered.
PMID- 10780239
TI - Differential expression of response-disruptive and somatic indices of opiate
withdrawal during the initiation and development of opiate dependence.
AB - The current study examined the conditions that are necessary and sufficient for
the initiation and progression of acute morphine dependence using two indices of
opiate withdrawal: suppression of operant response rates and a somatic withdrawal
rating scale. Separate groups of rats were pretreated with morphine (5 mg/kg,
s.c.) a total of three times at intervals of 24 h, 1, 3, or 6 weeks. Rats
received a single dose of naloxone 4 h after each morphine pretreatment. Naloxone
induced suppression of operant responding (0.33 mg/kg, s.c.) was significantly
potentiated with repeated exposure to morphine even at the 6-week inter-treatment
interval (ITI). At 24-h, 1-week and 3-week ITIs, rats treated with naloxone only
after the third and final morphine pretreatment showed similar suppression of
operant responding following naloxone to rats treated with naloxone after all
three morphine pretreatments. However, at the 6-week ITI, the response-disruptive
effects of naloxone administered for the first time after the third morphine
pretreatment were no greater than the effects of naloxone administered after a
single morphine pretreatment. In contrast to results seen with suppression of
operant responding as the withdrawal index, potentiation of somatic signs of
withdrawal was observed only at the 24-h ITI. These results indicate that a
neuroadaptive state resembling opiate dependence can be initiated after just one
injection of morphine, and that the response-disruptive effects of naloxone
appear to be a particularly sensitive index of the initiation and progression of
acute opiate dependence.
PMID- 10780241
TI - Individual differences in behavioral tolerance to amphetamine and the economic
context of reinforcement loss.
AB - The economic context (i.e. an enriched vs impoverished environment) affects many
drug-induced phenomena. The present study examined whether the 'experienced'
economic context of operant responding was associated with the degree of
tolerance to the behavioral effects of amphetamine. Eight rats lever pressed for
food reinforcement under a multiple schedule consisting of several variable
interval schedules (8, 17, 55, 150, and 250 s). Amphetamine was first
administered acutely (0.2, 0.8, 1.6, and 3.2 mg/kg), then chronically (dose
tailored for each subject) over 30 consecutive sessions. Baseline saline
injections were also administered during the acute regimen. Herrnstein's single
alternative matching equation described the rats' response rate data well under
all conditions. A parameter in Herrnstein's equation (re), which has been shown
to vary with experimentally-arranged contextual reinforcement, was used as the
index of the experienced economic context for each subject under baseline
conditions. Differences in the value of re predicted individual differences in
the degree of tolerance. Under most variable-interval (VI) schedules, and when
all schedules were aggregated, less tolerance accrued if the baseline context was
experienced as enriched, and more tolerance accrued if the baseline context was
experienced as impoverished. In terms of the reinforcement loss hypothesis, the
results suggest that tolerance was not determined by reinforcement loss per se,
but by how much the animal lost relative to the economic context in which the
operant task was embedded.
PMID- 10780242
TI - Subjective and behavioral effects of repeated d-amphetamine in humans.
AB - Behavioral sensitization is thought to be an important determinant of drug-taking
and drug-seeking behaviors. Although there is abundant research characterizing
behavioral sensitization in animals, there is little evidence for this phenomenon
in humans. The aim of the present study was to determine if repeated oral d
amphetamine administration enhances self-reported mood and other behavioral
indices of d-amphetamine effects in humans. Sixteen healthy volunteers, with no
prior stimulant use, received two doses of d-amphetamine (20 mg) and two doses of
placebo, in alternating order, on 4 consecutive days, under double-blind
conditions. Mood and behavioral effects were measured using standard self-report
questionnaires. Heart rate, blood pressure, psychomotor performance, and tapping
speed were also monitored. d-Amphetamine elicited prototypical increases on
several measures including self-reported drug effects, mood, and physiological
responses. However, except for a slight reduction in 'feel drug' scores during
the first hour of the second d-amphetamine session, the majority of effects were
not altered on the second session. These results indicate that the subjective
effects of d-amphetamine display only an apparent mild tolerance after a single
exposure 48 h earlier.
PMID- 10780243
TI - Individual differences in subjective responses to ethanol and triazolam.
AB - This study evaluated the relationship between sedative-like subjective responses
to ethanol and triazolam in normal, healthy volunteers. It was hypothesized that
subjects' responses to the two drugs would be correlated, because of the common
mechanism of action of the drugs at the GABAA receptor complex. Twenty-seven
volunteers (14 male, 13 female), aged 21-35 years, received beverages or capsules
containing ethanol (0.2, 0.4 or 0.8 g/kg), triazolam (0.125, 0.25 or 0.5 mg) or
placebo (two sessions) on eight separate sessions in a random order. Various self
reported and objective drug effects were measured, including measures of sedative
like subjective effects, as indexed by the ARCI PCAG scale. PCAG scores of
individual subjects across the three active doses of each drug were fitted with a
straight line function (y = a + bx), and the correlation of the slopes from the
fitted curves for ethanol and triazolam was examined. Among the participants who
reported any sedative-like responses to ethanol, the sedative-like effects of
ethanol and triazolam were positively correlated. That is, subjects who exhibited
the steepest dose-related effects on measures of subjective sedation after
ethanol also exhibited the steepest slopes after triazolam. These findings
provide partial support for the idea that ethanol and triazolam produce their
sedative-like effects through the same mechanism.
PMID- 10780244
TI - An investigation of endogenous neuroactive steroid-induced modulation of
ethanol's discriminative stimulus effects.
AB - Neuroactive steroids exhibit rapid non-genomic central nervous system activity,
including modulation of GABAA and NMDA receptors, two receptors known to mediate
the effects of methanol. Neuroactive steroids that modulate GABAA receptors in a
manner similar to ethanol were expected to potentiate the discriminative stimulus
and/or rate-suppressing effects of ethanol. In contrast, neuroactive steroids
that modulate GABAA or NMDA receptors in a manner opposite to ethanol were
hypothesized to attenuate the effects of ethanol. Adult male rats were trained to
discriminate 1.0 or 2.0 g/kg ethanol (i.g.) from water (i.g.). Animals were
pretreated with subthreshold doses (i.p.) of ethanol and neuroactive steroids and
exposed to an acute stressor (n = 5), prior to conducting ethanol cumulative
dosing (i.p.) tests. Only ethanol and 3 beta, 5 beta-P pretreatments potentiated
the discriminative stimulus effects of ethanol. None of the six neuroactive
steroid manipulations attenuated the effects of ethanol. These results
demonstrate that a neuroactive steroid, endogenous in humans, can enhance the
interoceptive effects of ethanol.
PMID- 10780245
TI - Further characterization of the quinine taste discrimination stimulus in rhesus
monkeys: effects of inter-trial interval, number and distribution of test
stimuli.
AB - The purpose of the current investigation was to characterize further the taste
discriminative stimulus properties of quinine. Using a food-maintained two-choice
(quinine and water) discrimination paradigm, the effects of varying inter-trial
intervals, and the number and distribution of test stimuli were examined in
rhesus monkeys (Macaca mulatta). Monkeys were trained to respond under a chain
schedule of reinforcement (FR5B-fluid, FR30B-food) with a 60-s inter-trial
interval. Interestingly, the quinine discrimination remained invariant across all
the conditions tested: alterations in inter-trial interval (0, 15, 30, 45, 60 s),
alterations in the number of test stimuli (six at quarter-log unit increments
[0.1-1 mg/ml] versus 10 at quarter-log unit increments [0.01-1 mg/ml]), and
alterations in the distribution of the test stimuli (quarter-log unit increments
[0.1-0.1 mg/ml] versus half-log unit increments [0.01-1 mg/ml]) failed to alter
the quinine discriminative stimulus (ED50s ranged from 0.18-0.29 mg/ml).
Furthermore, incorrect lever selections were very rare (less than 12% of all test
sessions), independent of test stimuli order (i.e. quinine followed by water
trials, water followed by quinine trials), and independent of the progress
through the test session (i.e. incorrect lever selections were consistent-
approximately one error for every 10 trials--within early, middle and late
portions of the session). These results demonstrate the reliability and
robustness of the quinine taste discriminative stimulus in rhesus monkeys and
provide further validation for the experimental paradigm.
PMID- 10780246
TI - Effects of the group II metabotropic glutamate receptor agonist, LY354740 on
schedule-controlled behaviour in rats.
AB - The present study examined the effect of the novel, systemically active Group II
metabotropic glutamate (mGlu) receptor agonist, LY354740, on schedule-controlled
behaviour in rats. Responding for food reward was maintained by three different
operant procedures; the first, a three-component conflict schedule; the second, a
multiple fixed-interval 60 s/fixed-ratio 10 (FI60/FR10) schedule and the third, a
differential reinforcement of low rates of responding 10 s (DRL10) schedule. In
the first procedure, rats were trained to respond for food on a schedule
comprising of variable-interval 30 s (food, VI30) and fixed-ratio 10 (food +
shock, FR10) components separated by time-out (TO). LY354740 (1.25-5 mg/kg, i.p.)
produced a dose-related reduction in responding during the VI component and
increased responding during the TO component, while having no effect on
responding during the punished FR10 phase. In the FI60/FR10 schedule, LY354740
produced a dose-related reduction in the high rates of responding observed during
the FR10 component of the schedule. Although LY354740 (0.6-10 mg/kg, i.p.) had no
effect on the overall response rates produced by the FI60 component, there was a
shift in the temporal distribution of responding as measured by the quarter-life.
LY354740 (10 mg/kg, i.p.) increased the low rates towards the start of the
interval, while decreasing the rates of responding towards the end of the FI60
period. In the DRL10 s schedule, LY354740 (5-20 mg/kg, i.p.) had no effect on the
total number of responses but produced a significant reduction in the total
number of rewards, suggesting that the temporal control of responding had been
disrupted. The changes in operant responding occurred at doses that decreased
exploratory behaviour. In summary, LY354740 modified responding maintained by all
three operant schedules at doses which suppressed spontaneous activity. These
data demonstrate that stimulation of Group II mGlu receptors can produce changes
in responding which are dependent on the base-line rate of responding, suggesting
that mGlu 2/3 receptors may be involved in the stimulus and temporal control of
behaviour.
PMID- 10780247
TI - SR 141716A, a cannabinoid receptor antagonist, reverses the behavioural effects
of anandamide-treated rats.
AB - We employed the CB1 cannabinoid receptor antagonist SR 141716A (3 mg/kg, i.p.) to
investigate whether behavioural effects induced in rats by anandamide, an
endogenous cannabinoid (20 mg/kg, i.p.), were mediated by the cannabinoid CB1
receptor. Anandamide reduced ambulatory (67%) and non-ambulatory activities
(rearing and grooming, 84% and 90% respectively), with a strong cataleptic
effect, produced hypothermia (about -1 degree C) and hindlimb splaying, and
reduced defecation (79%). It did not significantly increase either the tail-flick
or hot-plate latencies. Except for the decreased defecation, these responses were
all blocked by SR 141716A. Although only single doses of the agonist and
antagonist were used, the findings indicate that these behavioural effects are
probably mediated by an interaction with cannabinoid CB1 receptors.
PMID- 10780248
TI - Effects of nicotine on spatial learning in C57BL mice.
AB - In the present study, the effects of nicotine on spatial memory in C57BL/6J mice
was evaluated. Mice were trained in a water maze during four daily sessions of
three trials each. In the first experiment, nicotine (0.7 and 0.35 mg/kg) or
saline was administered once daily for 4 days, 15 min before the start of daily
training: an impairment of performance of the water maze was observed in the
group treated with 0.7 mg/kg of nicotine. In the second experiment, nicotine (0.7
and 0.35 mg/kg) or saline was administered from the 5 days prior to the beginning
of the task and during the 4 days of acquisition. The results indicated an
improvement in the rate of learning in the 9-day nicotine treated groups. The
comparison between 4-day and 9-day treated groups revealed that the group
receiving 0.35 mg/kg of nicotine for 9 days displayed significantly shorter
latencies than all the other groups, while the group receiving 0.7 mg/kg of
nicotine for 4 days performed significantly worse than all the other groups. The
most noteworthy result is that nicotine was more effective after a more prolonged
administration than when administered only during the training days.
PMID- 10780249
TI - Anxiety in a transgenic mouse model of cortical-limbic neuro-potentiated
compulsive behavior.
AB - Anxiety and amygdalar stimulation may induce or exacerbate compulsions triggered
by cortical-limbic hyperactivity, as in human obsessive-compulsive disorder
(OCD). We previously created transgenic mice that exhibit OCD-like biting,
movement and behavioral perseverance abnormalities. These behaviors are caused by
expression of a neuro-potentiating cholera toxin (CT) transgene in dopamine D1
receptor-expressing (D1+) neurons within the amygdalar intercalated nucleus (ICN)
and within cortical areas that project to orbitofrontal cortex and striatum. Here
we tested whether anxiety and increased amygdalar stimulation may play a role in
eliciting or exacerbating such behaviors. D1CT mice exhibited increased
thigmotaxis (tendency of mice to remain along the perimeter of open areas) in the
open field assay, and increased latency to first transit and reduced transit
number in the light-dark assay. These studies indicate that the D1CT mice exhibit
a significant increase in behavioral indicators of anxiety. Furthermore,
yohimbine, a drug that induces both amygdalar stimulation and behavioral
indicators of anxiety, exacerbated abnormal leaping in D1CT mice but failed to
exacerbate their abnormal behavioral perseverance. These data suggest that
chronic potentiation of D1+ neurons in the amygdalar ICN increases anxiety and
facilitates particular compulsive behaviors.
PMID- 10780250
TI - Assessing memory in mice using habituation of nose-poke responding.
AB - The present experiments investigated the validity and utility of measuring the
habituation of a nose-poke response to assess memory in mice. Mice were placed in
an operant chamber equipped with two holes in one wall. Nose-poke responses were
recorded by the interruption of a photo-beam across the openings of the holes.
Responding produced no consequences. Nose-poke responding was recorded over 20
min for one-four daily sessions. Habituation, as defined by a decrease in the
number of nose-pokes over time, was observed during sessions as well as between
daily sessions. When the inter-session interval was increased from 1 to 8 days,
habituation decayed in a time-dependent manner indicating memory was involved in
the habituation phenomenon. CD-1, C57/BL and Swiss Webster X DBA mouse strains
all displayed robust time-dependent habituation. Scopolamine, in CD-1 mice, dose
dependently disrupted habituation in an anterograde (0.1-1 mg/kg) and retrograde
(1-10 mg/kg) procedure. The present procedure provides a rapid and novel method
to assess habituation in a variety of strains of mice and may be a useful
addition to existing procedures for measuring memory function in mice.
PMID- 10780251
TI - Strain-dependent effects of anandamide on memory consolidation in mice are
antagonized by naltrexone.
AB - Post-training administration of anandamide (1.5, 3, 6 mg/kg) dose-dependently
impaired retention of an inhibitory avoidance response in DBA/2 mice, while
improving it in C57BL/6 mice. The effects on retention performance induced by the
drug appear to be due to an effect on memory consolidation. They were observed
when drug was given at short, but not long, periods of time after training, i.e.
when the memory trace was susceptible to modulation. These effects of anandamide
parallel those of opioid agonists, as previously reported. Moreover, the opioid
antagonist naltrexone improved retention in DBA/2 mice, while impairing it in
C57BL/6 mice. Pre-treatment with the opioid antagonist at a non-effective dose
(0.1 mg/kg) antagonized the effects of anandamide on memory consolidation in both
strains. These results strongly suggest that endogenous cannabinoids affect
memory processes through opioid systems. The possible involvement of other
neurotransmitter systems, such as dopamine, in strain-dependent effects of
anandamide in memory consolidation is discussed.
PMID- 10780252
TI - Daily injections of cyanamide enhance both ethanol-induced locomotion and brain
catalase activity.
AB - A role for brain catalase in the mediation of some psychopharmacological effects
of ethanol has been proposed. In the present study, we investigated the effects
of repeated cyanamide injections on the activity of brain catalase, as well as on
the ethanol-induced locomotion of mice. Male Swiss mice were pre-treated with
cyanamide (10 mg/kg; three times per day, 5 days) or saline. At different times
(2, 3, 6 or 9 days) following this treatment, animals were injected with ethanol.
Immediately following this ethanol challenge, animals were placed in the open
field chambers and locomotor activity was assessed for 10 min. Results indicated
an increase in ethanol-induced locomotion of mice pre-treated with cyanamide 2, 3
or 6 days before the ethanol challenge. Brain catalase activity showed an
enhancement at the same time period and the two variables showed a significant
correlation. No differences between pre-treatment groups on ethanol blood levels
were observed at time of testing. In a second study, the effects of these
cyanamide treatment conditions on d-amphetamine-induced locomotor activity were
assessed. Results indicated no differences between pre-treatment groups in d
amphetamine-induced locomotion. Thus, these data suggest that repeated daily
injections of cyanamide can simultaneously induce both brain catalase and
locomotor activity, and that these effects may be strongly related. Furthermore,
the present study provides further support for the notion that brain catalase
activity may be a factor mediating some of the psychopharmacological effects of
ethanol.
PMID- 10780253
TI - Relationship of dopamine to serotonin in the neonatal 6-OHDA rat model of Lesch
Nyhan syndrome.
AB - Rats were treated as neonates with either 6-hydroxydopamine (6-OHDA) 100
micrograms or vehicle intracisternally. Upon maturation, animals receiving 6-OHDA
were assigned to four groups, with two of the four groups receiving
intraventricular 5,7-dihydroxytryptamine (5,7-DHT) 75 micrograms bilaterally. At
94 days of age, animals were injected with either SKF-38393 (3.0 mg/kg,
intraperitoneally (i.p.)), a dopamine D1 agonist, or m-chlorophenylpiperazine (m
CPP) (3.0 mg/kg, i.p.), a 5-HT2C agonist, in an attempt to evoke behaviors such
as stereotypical chewing, head-nodding, self-biting and self-mutilation. Both SKF
38393 and m-CPP induced the target behaviors in animals receiving 6-OHDA alone.
Animals receiving additional 5,7-DHT treatment did not show any of the target
behaviors in response to SKF-38393, but exhibited a much higher sensitivity to m
CPP. Pre-treatment with SCH-23390 in animals receiving 6-OHDA alone was effective
in preventing SKF-38393-induced target behaviors, but not those induced by m-CPP.
Pre-treatment with mianserin partially antagonized the effects of both SKF-38393
and m-CPP in these same animals. In groups receiving both neonatal 6-OHDA and
adult 5,7-DHT, mianserin was effective in reducing m-CPP-induced behaviors, while
SCH-23390 was largely ineffective. These data provide evidence of a serial
relationship between the D1 and 5-HT2C receptor systems in the neostriatum of
animals receiving neonatal 6-OHDA lesions.
PMID- 10780254
TI - Rapid recovery of self-stimulation responding from depression by clozapine is
prevented by the alpha 2-adrenoceptor agonist, clonidine.
AB - Typical and atypical antipsychotic agents were tested on rats responding for
variable-interval electrical stimulation of the ventral tegmental area (VTA). The
typical neuroleptics, chlorpromazine and haloperidol, led to prolonged depression
of responding lasting at least 4 h, whereas response rates after similarly
effective doses of the atypical agents, clozapine and risperidone, recovered to
control levels in the same period. The role of alpha 2-adrenoceptors in producing
these differences was investigated by administering clozapine together with an
alpha 2-adrenoceptor agonist, clonidine, and chlorpromazine together with an
alpha 2-adrenoceptor antagonist, idazoxan. The addition of clonidine extended the
response-depressant activity of clozapine, resulting in prolonged depression
comparable to that produced by chlorpromazine or haloperidol. Conversely, the
addition of idazoxan to chlorpromazine shortened the duration of chlorpromazine's
suppressant action to a level comparable to that of clozapine or risperidone.
These results suggest that the brevity of clozapine's effects on operant
behaviour (a feature which may be related to its reduced liability to
extrapyramidal side-effects) may be a consequence of its alpha 2-adrenoceptor
antagonist properties.
PMID- 10780255
TI - Comparison of the pharmacological properties of classical and novel BZ-omega
receptor ligands.
AB - The experiments in this study compared the pharmacological properties of several
BZ-omega receptor ligands, including the imidazobenzodiazepine imidazenil, the
beta-carboline abecarnil, the pyridazinone Y-23684, the pyrido [1,2
a]benzimidazole RWJ 46771 and the 1,6-naphthyridin-2(1H)-one derivative SX-3228,
with the prototypical BZs diazepam, clobazam and bretazenil. In in vitro
experiments diazepam, bretazenil, imidazenil and Y-23684 displaced [3H]flumazenil
binding non-selectively in membranes from rat cerebellum and spinal cord, two
brain areas enriched in the BZ-omega 1 and BZ-omega 2 receptor subtypes,
respectively. In contrast, abecarnil, RWJ 46771 and SX-3228 were more potent in
displacing [3H]flumazenil binding to membranes from rat cerebellum than from
spinal cord or hippocampus, indicating selectivity for the BZ-omega 1 receptor
subtype. The in vivo experiments showed that all compounds increased the latency
to clonic seizures produced by isoniazid. However, the maximal increase in
latency induced by diazepam, clobazam, abecarnil, RWJ 46771 and SX-3228 was
greater than that of bretazenil, imidazenil and Y-23684, thereby indicating that
these latter compounds have low intrinsic efficacy. In the punished drinking, the
punished lever pressing and the elevated plus-maze tests in rats, three models of
anxiety, diazepam, clobazam and imidazenil elicited clear anxiolytic-like effects
but at doses which were close to those producing hypolocomotion, ataxia and
myorelaxation as measured in activity cages, the rotarod and the loaded grid
tests, respectively. In contrast, bretazenil and Y-23684 induced anxiolytic-like
activity at much lower doses than those which impaired motor performances. The
magnitude of the positive effects of Y-23684 was similar to that of the reference
BZs, suggesting that it may become a valuable alternative to currently used
agents for the treatment of anxiety disorders. Abecarnil, RWJ 46771 and SX-3228
produced weaker or non-specific anxiolytic-like effects as they decreased anxiety
related behaviours at doses similar or close to those impairing motor
performance. However, unlike the other compounds they induced myorelaxation at
doses which were 3-10 times higher than those needed to produce decrease in
exploratory activity. It is suggested that the behavioural profiles of abecarnil,
RWJ 46771 and SX-3228 may be attributed to their selectivity for the BZ-omega 1
receptor subtype which may account for their sedative activity, thereby masking
other effects including anxiolytic-like activity. This suggests that BZ receptor
modulation of anxiety may involve BZ receptor subtypes other than BZ-omega 1.
PMID- 10780256
TI - Cannabinoid ligands and their effects on learning and performance in rhesus
monkeys.
AB - To characterize the role of CB1 receptors in mediating the acquisition of new
behavior or learning, delta 9-THC (delta 9-tetrahydrocannabinol), WIN 55,212-2 (R
(+)-(2,3-dihydro-5-methyl-3-[(4-morpho-linyl)methyl]pyrol - (1,2,3-de]-1,4
benzoxazin-6-yl)(1-naphthalenyl)methanone monomethanesulfonate), SR141716A (N
(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlor- phenyl)-4-methyl-1H-pyrazole
3-carboxamide hydrochloride) and cannabidiol were administered to monkeys
responding under a multiple schedule of repeated acquisition and performance of
conditional discriminations. SR141716A, a putative antagonist at CB1 receptors,
was also administered in combination with delta 9-THC. In one component of the
multiple schedule, subjects acquired a different complex discrimination each
session (acquisition component), whereas in the other component the
discrimination remained the same each session (performance component). Correct
responding in each component was maintained by food presentation under a variable
ratio (VR) schedule, whereas incorrect responding (errors) produced a time-out.
Administered prior to the start of the session, delta 9-THC and WIN 55,212-2 dose
dependently decreased overall response rate in both the acquisition and
performance components. Both drugs also selectively increased the percentage
errors in the acquisition component, but only at higher doses. SR141716A and
cannabidiol also dose-dependently decreased overall response rate in both
schedule components, but neither drug increased the percentage of errors.
Decreases in response rate were also observed 24 hours after administration of
SR141716A at doses greater than 1 mg/kg. When lower doses of SR141716A (0.1-1
mg/kg) were administered in combination with delta 9-THC, there was a dose
dependent antagonism of the rate-decreasing and error-increasing effects of delta
9-THC (i.e. the dose-effect curves for delta 9-THC-induced disruptions in
responding were shifted rightward). In summary, CB1-receptor agonists such as
delta 9-THC and WIN 55,212-2 were more disruptive to the rate and accuracy of
learning in old-world monkeys than the CB1-receptor antagonist SR141716A or
cannabidiol.
PMID- 10780257
TI - Predicting relapse to cocaine-seeking behavior: a multiple regression approach.
AB - Recovery of previously extinguished responding to stimuli paired with the
administration of drugs of abuse is becoming a widely utilized animal model of
relapse to drug-seeking behaviors. While this approach is useful for identifying
factors such as conditioned stimuli that are associated with drug-seeking, it has
not directly identified behaviors that might predict susceptibility to relapse.
In this study, rats were initially screened for locomotor activity in response to
a novel environment. Rats were then trained to self-administer cocaine. A
stimulus light and tone were paired with each infusion of cocaine. After 14 days
of self-administration (maintenance) rats underwent 7 days of extinction trials
(extinction phase 1), in which responding yielded neither cocaine nor the
presentation of the conditioned stimulus. After extinction phase 1, rats
responded for presentations of the compound stimulus in the absence of cocaine
(test day 1). Rats then underwent 3 more days of extinction (extinction phase 2).
After extinction phase 2, rats were once again allowed to self-administer cocaine
(test day 2) and received presentations of the compound stimulus. Hierarchical
regression equations, utilizing data from locomotor screening and the average
responding during maintenance and extinction phases 1 and 2, were then
constructed in order to predict the magnitude of responding on test days 1 and 2.
A model utilizing locomotor activity, maintenance responding and extinction phase
1 responding accounted for over 76% of the variance associated with responding on
test day 1, with extinction phase 1 as best predictor. A further model indicated
that locomotor activity was the best predictor of propensity to self-administer
cocaine on test day 2. These regression models provide a novel approach to
determining factors that may predict relapse to drug-seeking behaviors.
PMID- 10780258
TI - Blockade of cocaine-induced increases in adrenocorticotrophic hormone and
cortisol does not attenuate the subjective effects of smoked cocaine in humans.
AB - Surgical or pharmacological ablation of the hypothalamic-pituitary-adrenal (HPA)
axis reduces the discriminative stimulus and reinforcing effects of cocaine in
laboratory rodents. We have recently reported that attenuation of cocaine-induced
increases in cortisol does not modulate the subjective effects of smoked cocaine
in humans. To examine whether attenuation of HPA function at the pituitary level
reduces the effects of cocaine in humans, eight 'crack' cocaine abusers were pre
treated with the synthetic glucocorticoid, dexamethasone (0 and 2 mg), 10 h
before receiving cocaine. Three doses of smoked cocaine (0, 12 and 50 mg) were
administered in counterbalanced order under each pre-treatment condition.
Dexamethasone alone increased heart rate and blood pressure, and completely
abolished cocaine-induced adrenocorticotrophic hormone and cortisol release.
Maximal heart rate following cocaine administration was significantly increased
by dexamethasone. However, the subjective effects of cocaine were not affected by
dexamethasone pre-treatment. These results extend our earlier findings with
humans, indicating that the role of the HPA axis in mediating the effects of
cocaine is limited. These data are concordant with findings in non-human
primates, but contrast with findings in laboratory rodents, thus underscoring the
importance of validation of rodent models with laboratory studies in humans.
PMID- 10780259
TI - Low-dose oral cocaine in humans: acquisition of discrimination and time-course of
effects.
AB - Seven cocaine-abusing volunteers were trained to discriminate 50 mg oral cocaine
vs placebo across 50 2-h sessions. Discriminative, subjective and autonomic
effects were assessed with a procedure developed for precise characterization of
their acute time-course. Subjective effects of oral cocaine began 10-15 min post
drug, peaked at 40-50 min and took up to 100 min post-drug to return nearly to
baseline. Autonomic effects also began 10-15 min post-drug, peaked at 40-50 min
and typically returned to baseline by 120 min post-drug; for most participants,
peak heart rate and blood pressure remained within the range seen with placebo.
Six out of seven participants acquired the discrimination (although this
typically required 15-30 sessions, and there were some intriguing dissociations
between the ability to discriminate oral cocaine from placebo and the ability to
identify it as a stimulant). In most participants, oral cocaine produced
increases in ratings of 'liking', 'alertness' and 'good effects', and in motor
performance. Overall, the results support the sensitivity of the behavioral
testing procedure used, and show that 50 mg oral cocaine can serve as a
discriminative stimulus in adult humans.
PMID- 10780260
TI - Daily mirfentanil induces (cross-) tolerance to the rate-decreasing effects of
morphine and not mirfentanil.
AB - The fentanyl derivative mirfentanil has a novel set of behavioral effects in non
humans including low-efficacy opioid actions and non-opioid antinociceptive
actions. This study evaluated the rate-decreasing effects of mirfentanil,
morphine, naltrexone and ketamine in pigeons both prior to and during a period of
chronic treatment with mirfentanil (3.2-17.8 mg/kg/day). Daily treatment with
mirfentanil did not modify the rate-decreasing effects of mirfentanil or
ketamine; however, daily treatment decreased sensitivity to the rate-decreasing
effects of morphine and increased sensitivity to naltrexone. These results
demonstrate a lack of tolerance to an apparently non-opioid action (rate
decreasing effect) of mirfentanil, which might predict a lack of tolerance to the
non-opioid antinociceptive actions of this compound. These results further
indicate that cross-tolerance (to morphine) and dependence (increased sensitivity
to naltrexone) can occur in the absence of tolerance (to mirfentanil).
PMID- 10780261
TI - Memory restoring and neuroprotective effects of the proline-containing dipeptide,
GVS-111, in a photochemical stroke model.
AB - Local thrombosis of the frontal cortex (Fr1 and Fr3 fields), caused by
combination of the intravenous photosensitive dye Rose Bengal administration with
focused high-intensity illumination of the frontal bone, was shown to provoke a
pronounced deficit in step-through passive avoidance performance in rats without
concomitant motor disturbances. N-Phenylacetyl-L-prolylglycine ethyl ester (GVS
111) administered intravenously at a dose of 0.5 mg/kg/day, for the first time 1
h after ischaemic lesion and then for 9 post-operative days, with the last
administration 15 min before testing, attenuated the deficit. This treatment
significantly diminished the volume of the infarcted area. Thus, post-ischaemic
injection of GVS-111 demonstrated both cognition-restoring and neuroprotective
properties. The cognition-restoring effect is probably based on an increase in
neocortical and hippocampal neuronal plasticity. Neuroprotective effects of GVS
111 combine antioxidant activity with the ability to attenuate glutamate-provoked
neurotoxicity and block voltage-gated ionic channels, i.e. the compound mitigates
the main metabolic shifts involved in pathogenesis of brain ischaemia.
PMID- 10780262
TI - Eukaryotic aldehyde dehydrogenase (ALDH) genes: human polymorphisms, and
recommended nomenclature based on divergent evolution and chromosomal mapping.
AB - As currently being performed with an increasing number of superfamilies, a
standardized gene nomenclature system is proposed here, based on divergent
evolution, using multiple alignment analysis of all 86 eukaryotic aldehyde
dehydrogenase (ALDH) amino-acid sequences known at this time. The ALDHs represent
a superfamily of NAD(P)(+)-dependent enzymes having similar primary structures
that oxidize a wide spectrum of endogenous and exogenous aliphatic and aromatic
aldehydes. To date, a total of 54 animal, 15 plant, 14 yeast, and three fungal
ALDH genes or cDNAs have been sequenced. These ALDHs can be divided into a total
of 18 families (comprising 37 subfamilies), and all nonhuman ALDH genes are named
here after the established human ALDH genes, when possible. An ALDH protein from
one gene family is defined as having approximately < or = 40% amino-acid identity
to that from another family. Two members of the same subfamily exhibit
approximately > or = 60% amino-acid identity and are expected to be located at
the same subchromosomal site. For naming each gene, it is proposed that the root
symbol 'ALDH' denoting 'aldehyde dehydrogenase' be followed by an Arabic number
representing the family and, when needed, a letter designating the subfamily and
an Arabic number denoting the individual gene within the subfamily; all letters
are capitalized in all mammals except mouse and fruit fly, e.g. 'human ALDH3A1
(mouse, Drosophila Aldh3a1).' It is suggested that the Human Gene Nomenclature
Guidelines (http://++www.gene.ucl.ac.uk/nomenclature/guidelines.h tml) be used
for all species other than mouse and Drosophila. Following these guidelines, the
gene is italicized, whereas the corresponding cDNA, mRNA, protein or enzyme
activity is written with upper-case letters and without italics, e.g. 'human,
mouse or Drosophila ALDH3A1 cDNA, mRNA, or activity'. If an orthologous gene
between species cannot be identified with certainty, sequential naming of these
genes will be carried out in chronological order as they are reported to us. In
addition, 20 human ALDH variant alleles that have been reported to date are
listed herein and are recommended to be given numbers (or a number plus a capital
letter) following an asterisk (e.g. 'ALDH3A2*2, ALDH2*4C'). It is anticipated
that this eukaryotic ALDH gene nomenclature system will be extended to include
bacterial genes within the next 2 years and that this nomenclature system will
require updating on a regular basis; an ALDH Web site has been established for
this purpose (http://++www.uchsc.edu/sp./sp./alcdbase/a ldhcov.html) and will
serve as a medium for interaction amongst colleagues in this field.
PMID- 10780263
TI - Influence of CYP2D6 activity on the disposition and cardiovascular toxicity of
the antidepressant agent venlafaxine in humans.
AB - According to in-vitro studies with microsomes from human livers and from yeast
expression systems with high CYP2D6 activity, the major oxidation pathway of
venlafaxine is catalysed by CYP2D6. In this study, we investigated the role of
the CYP2D6 polymorphism and the effects of low-dose quinidine, a selective
inhibitor of, CYP2D6, on the disposition of venlafaxine. Fourteen healthy men,
eight with the extensive metabolizer and six with the poor metabolizer phenotype
were administered venlafaxine hydrochloride 18.75 mg orally every 12 h for 48 h
on two occasions (1 week apart); once alone and once during the concomitant
administration of quinidine sulfate 100 mg every 12 h. Blood and urine samples
were collected under steady-state conditions over one dosing interval (12 h).
When venlafaxine was administered alone, the oral clearance of venlafaxine was
more than fourfold less in poor metabolizers compared to extensive metabolizers
(P < 0.05). This was mainly due to a decreased capability of poor metabolizers to
form O-desmethylated metabolites at the position 4 of the aromatic moiety. In
extensive metabolizers, quinidine decreased venlafaxine oral clearance from 100
+/- 62 l/h to 17 +/- 5 l/h (mean +/- SD; P < 0.05) without any effects on renal
clearance (4 +/- 1 l/h during venlafaxine alone and 4 +/- 1 l/h during
venlafaxine plus quinidine). In these individuals, the sequential metabolism of
venlafaxine to O-desmethylvenlafaxine and to N,O-didesmethylvenlafaxine was
inhibited by quinidine coadministration so that metabolic clearances to O
desmethylated metabolites decreased from 43 +/- 32 l/h to 2 +/- 1 l/h (P < 0.05).
In poor metabolizers, coadministration of quinidine did not cause significant
changes in oral clearance and partial metabolic clearances of venlafaxine to its
various metabolites. Decreased CYP2D6 activity could also be associated with
cardiovascular toxicity as observed in four patients during treatment with the
drug. Thus, genetically determined or pharmacologically altered CYP2D6 activity
represents a major determinant of venlafaxine disposition in humans.
PMID- 10780264
TI - Genetic polymorphisms influence variability in benzene metabolism in humans.
AB - The role of genetic polymorphism in modulating urinary excretion of two benzene
metabolites, i.e. trans,trans-muconic acid (t,t-MA) and S-phenylmercapturic acid
(PMA), has been investigated in 59 non-smoking city bus drivers, professionally
exposed to benzene via vehicle exhausts. Exposure to benzene was determined by
personal passive samplers (mean +/- SD = 82.2 +/- 25.6 micrograms/m3), while
internal dose and metabolic rate were evaluated by measuring urinary excretion of
unmodified benzene (mean +/- SD = 361 +/- 246 ng/l), t,t-MA (mean +/- SD = 602 +/
625 micrograms/g creatinine), and PMA (mean +/- SD = 5.88 +/- 4.76 micrograms/g
creatinine). Genetic polymorphism at six loci encoding cytochrome-P450-dependent
monooxygenases (CYP2E1 and CYP2D6), glutathione-S-transferases (GSTT1, GSTP1 and
GSTM1) and NAD(P)H:quinone oxidoreductase (NQOR) was determined by polymerase
chain reaction-based methods. No evidence emerged for a possible role of CYP2E1,
GSTM1 and GSTP1 polymorphisms in determining the wide differences observed in the
rate of benzene biotransformation. Conversely, a significantly higher t,t-MA
urinary excretion was found to be correlated to, GSTT1 null genotype, and a
significantly lower PMA excretion was detected in the subjects lacking NQOR
activity and in the CYP2D6 extensive-metabolizers. Many biological (i.e. age and
body burden) or lifestyle factors (i.e. rural or urban residence, use of paints
and solvents, medication, alcohol and coffee intake), also taken into account as
potential confounders, did not influence the correlations found. These findings
suggest that CYP2D6, GSTT1 and NQOR polymorphisms contribute in explaining the
metabolic variability observed in our sample. Therefore, these polymorphisms
should be regarded as potential risk factors for benzene-induced adverse health
effects.
PMID- 10780265
TI - Limitations of dextromethorphan N-demethylation as a measure of CYP3A activity.
AB - We evaluated the utility of the 3-methoxymorphinan/dextromethorphan (3MM/DM)
urinary ratio to reflect baseline CYP3A activity, and its ability to discriminate
moderate CYP3A inhibition during fluvoxamine therapy. For 4 months, oral
dextromethorphan 30 mg and intravenous midazolam 0.025 mg/kg were administered to
nine men every 14 days, and to 10 premenopausal women during the follicular and
luteal phases of their menstrual cycles. Phenotyping during the first 3 months or
cycles established baseline CYP3A activity. During the fourth month, individuals
were given fluvoxamine 150 mg/day. CYP3A activity was expressed as both the
urinary 3MM/DM molar ratio and midazolam plasma clearance (MDZ CL). 3MM/DM ratios
were independent of dextromethorphan CYP2D6 phenotype (r = 0.13, P = 0.6).
Intraindividual variability in baseline CYP3A activity (median, 25-75th
percentile), as determined by coefficients of variation, was 48.3% (36.8-68.8%)
for 3MM/DM and 10.3% (8.3-11.8%) for MDZ CL. No significant correlation between
3MM/DM and MDZ CL either at baseline (r = -0.22, P = 0.4) or during fluvoxamine
therapy (r = -0.15, P = 0.6) was noted. With fluvoxamine 150 mg/day, median
percentage change in the 3MM/DM ratios was -50.0% (-105.6-6.0%; P = 0.7), and
median percentage change in MDZ CL was -33.7% (-27.0-39.3%; P < 0.0001). Only MDZ
CL consistently indicated moderate inhibition of hepatic CYP3A activity. In
addition, there was a lack of correlation between the magnitudes of fluvoxamine
induced change in 3MM/DM and MDZ CL (r = 0.41, P = 0.1). The large
intraindividual variability of the 3MM/DM urinary ratio, as well as the inability
to discriminate moderate CYP3A inhibition, makes this a suboptimal method for
accurately assessing CYP3A activity.
PMID- 10780266
TI - Involvement of acetaldehyde for full protection against alcoholism by
homozygosity of the variant allele of mitochondrial aldehyde dehydrogenase gene
in Asians.
AB - There is a functional polymorphism of the mitochondrial aldehyde dehydrogenase
(ALDH2) gene with the variant allele (ALDH2*2) encoding a protein subunit that
confers low activity to the tetrameric enzyme. Genetic epidemiologic studies have
strongly suggested that homozygosity for the allele ALDH2*2 is sufficient in
completely inhibiting the development of alcoholism in Asians. To study the
pathophysiology of this unique pharmacogenetic effect, we recruited a total of
eighteen adult Han Chinese men, matched by age, body-mass index, nutritional
state and homozygosity at the alcohol dehydrogenase gene loci from a population
base of 273 men. Six individuals were chosen for each of the three ALDH2
allelotypes: homozygous ALDH2*2/*2, heterozygous ALDH2*1/*2, and homozygous
ALDH2*1/*1. Following a low dose of ethanol (0.2 g/kg body weight), blood
ethanol/acetaldehyde concentrations, cardiac and extracranial/intracranial
arterial hemodynamic parameters, as well as self-rated subjective sensations,
were measured for 130 min. Homozygous ALDH2*2 individuals were found to be
strikingly responsive to the small amount of alcohol, as evidenced by the
pronounced cardiovascular hemodynamic effects as well as subjective perception of
general discomfort for as long as 2 h following ingestion. This low-dose alcohol
hypersensitivity, accompanied by a prolonged and large accumulation of
acetaldehyde in blood, provides an explanation for the strong protection against
heavy drinking and alcoholism in individuals homozygous for the ALDH2*2 gene
allele.
PMID- 10780267
TI - Three and four dimensional-quantitative structure activity relationship (3D/4D
QSAR) analyses of CYP2D6 inhibitors.
AB - Three- and four-dimensional quantitative structure activity relationship (3D/4D
QSAR) pharmacophore models of competitive inhibitors of CYP2D6 were constructed
using data from our laboratory or the literature. The 3D-QSAR pharmacophore
models of the common structural features of CYP2D6 inhibitors were built using
the program Catalyst (Molecular Simulations, San Diego, CA, USA). These 3D-QSAR
models were compared with 3D and 4D-QSAR partial least squares (PLS) models which
were constructed using molecular surface-weighted holistic invariant molecular
(MS-WHIM) descriptors of size and shape of inhibitors. The first Catalyst model
was generated from multiple conformers of competitive inhibitors (n = 20) of
CYP2D6 mediated bufurolol 1'-hydroxylation. This model demonstrated a correlation
of observed and predicted Ki (apparent) values of r = 0.75. A second Catalyst
model was constructed from literature derived Ki (apparent) values (n = 31) for
the inhibition of CYP2D6. This model provided a correlation of observed and
predicted inhibition for CYP2D6 of r = 0.91. Both Catalyst Ki pharmacophores were
then validated by predicting the Ki (apparent) of a test set of known CYP2D6
inhibitors (n = 15). Ten out of 15 of these Ki (apparent) values were predicted
to be within one log residual of the observed value using our CYP2D6 inhibitor
model, while the literature model predicted nine out of 15 values. Similarly, 3D-
and 4D-QSARs derived from PLS MS-WHIM for our dataset yielded predictable models
as assessed using cross-validation. The corresponding cross-validated PLS MS-WHIM
model for the literature dataset yielded a comparable 3D-QSAR and improved 4D
QSAR value. Such computational models will aid in future prediction of drug-drug
interactions.
PMID- 10780268
TI - Tentative association of the serotonin transporter with schizophrenia and
unipolar depression but not with bipolar disorder in Han Chinese.
AB - The serotonin transporter gene (SERT) plays an important role in the serotonin
uptake into neurons. Recently, several polymorphisms including a variable-number
tandem-repeat (VNTR) in the second intron and an insertion/deletion polymorphism
(5-HTT linked polymorphic region, 5-HTTLPR) were identified and reported to be
associated with a variety of mental illnesses, including major depression,
bipolar disorder, anxiety-related traits, and autism. In our study, we performed
an association study between the SERT VNTR polymorphism and schizophrenia (n =
260), bipolar disorder (n = 137), and unipolar depression (n = 33) in the Han
Chinese. A large group of ethnically matched control individuals (n = 362) were
also genotyped. Allele 12 of the VNTR polymorphism was associated with
schizophrenia (P = 0.007) and unipolar depression (P = 0.011). Bipolar disorder
was not associated with the VNTR (P = 0.93). Thus, we conclude that the SERT VNTR
polymorphism may be a risk factor for both schizophrenia and unipolar depression,
but not for bipolar disorder, in the Han Chinese.
PMID- 10780269
TI - Association between glutathione S-transferase pi genetic polymorphisms and oral
cancer risk.
AB - Polymorphisms in the gene encoding the glutathione S-transferase (GST) pi
metabolizing enzyme have previously been associated with susceptibility to
various cancers. In this study, the importance of GSTP1 genotypes as determinants
of risk for oral cancer was assessed by examining the prevalence of GSTP1 alleles
in 157 incident oral cancer cases and 260 non-cancer control individuals
frequency-matched by race, sex, and age at diagnosis (+/- 5 years). The GSTP1*A,
GSTP1*B, GSTP1*C, and GSTP1*D alleles were elucidated by polymerase chain
reaction-restriction fragment length polymorphism analysis of polymorphisms
present in codons 105 (isoleucine:valine) and 114 (alanine:valine) of the GSTP1
gene. Increased risk for oral cancer was observed in individuals who were
homozygous for any combination of GSTP1 polymorphic alleles (i.e. *B, *C, and/or
*D alleles; odds ratio = 2.4, 95% confidence interval = 1.2-4.8). Similar risk
was observed in both Caucasians (odds ratio = 2.6, 95% confidence interval = 1.1
6.2) and African-Americans (odds ratio = 2.3, 95% CI = 0.68-7.5). A greater risk
was observed in individuals with the GSTP1 (Var/Var) genotype who were exposed to
low levels of smoking (i.e. < or = 20 pack-years [py], odds ratio = 3.4, 95%
confidence interval = 1.1-11) than among heavier smokers (i.e. > 20 pack-years
[py], odds ratio = 1.4, 95% confidence interval = 0.48-4.0). These results
suggest that GSTP1 genotype may play a role in risk for oral cancer particularly
among lighter smokers.
PMID- 10780270
TI - The dopamine D2 receptor 5'-flanking variant, -141C Ins/Del, is not associated
with reduced dopamine D2 receptor density in vivo.
AB - The Del allele of the -141C (Ins/Del) polymorphism located in the immediate 5'
flanking region of the human dopamine D2 receptor gene has been reported to be
associated with reduced promoter activity in vitro. However, genetic association
studies of the -141C (Ins/Del) polymorphism with schizophrenia and alcoholism
have yielded conflicting results. In this report, we explored the effect of the
Del allele on the D2 receptor binding characteristics in vivo in healthy
volunteers using positron emission tomography and D2 receptor antagonist,
[11C]raclopride. No difference in D2 receptor density was observed between the
Del allele carriers compared to the individuals with the Ins/Ins genotype,
indicating that the genetic variation at the -141C (Ins/Del) site does not affect
D2 receptor expression level in vivo.
PMID- 10780271
TI - Frequency of functionally important beta-2 adrenoceptor polymorphisms varies
markedly among African-American, Caucasian and Chinese individuals.
AB - There are ethnic differences in the prevalence and severity of hypertension and
asthma and in beta-2 adrenergic receptor (BAR2)-mediated vascular responses. Two
common polymorphisms of the human BAR2, Arg16 to Gly and Gln27 to Glu, are
associated with alterations in BAR2 response, both in vitro and in vivo. Ethnic
differences in disease manifestations and responses to treatment may be explained
by the altered frequency of BAR2 polymorphisms. To determine the relative
frequencies of the Arg16 to Gly and Gln27 to Glu BAR2 polymorphisms in different
ethnic groups we studied 415 (123 African-American, 188 Caucasian-American and
104 Chinese) healthy individuals. There was a marked interethnic difference in
the frequency of the BAR2 polymorphisms among the ethnic groups. The Glu27 allele
was more frequent in Caucasian-American (34.8%) than in African-American
individuals (20.7%) (P = 0.0001) and much less frequent in Chinese individuals
(7.2%) (P = 0.0001 versus African-American or Caucasian-American). The homozygous
Glu27 genotype was more frequent in Caucasian-American (15.4%) than African
American individuals (4.9%) (P = 0.003) and was not observed in Chinese. The
Gly16 allele (54.3% versus 41.3%) and homozygous genotype (35.1% versus 18.3%)
were more common in Caucasian-American than Chinese individuals (P = 0.003 for
both). There is a marked ethnic difference in the frequency of these two common
BAR2 polymorphisms among African-American, Caucasian-American and Chinese
individuals, with a markedly reduced frequency of the Glu27 polymorphism, the
polymorphism associated with resistance to desensitization and increased BAR2
responses, in African-American and Chinese individuals. Such ethnic genotypic
differences may explain previously observed alterations in the response to the
BAR agonists in different ethnic groups.
PMID- 10780272
TI - Genomic structure and sequence analysis of a human inositol polyphosphate 1
phosphatase gene (INPP1).
AB - Lithium remains the most widely used long-term treatment for bipolar affective
disorder, but the molecular mechanisms underlying its therapeutic efficacy have
not been fully elucidated. Two enzymes involved in the phospholipase C signalling
system, namely the myo-inositol monophosphatase (IMPase) and the inositol
polyphosphate 1-phosphatase (IPPase), have been postulated as targets for the
therapeutic action of lithium in manic-depressive illness. Intriguingly,
Drosophila mutants lacking IPPase activity display a defect in synaptic
transmission, and this alteration could be phenocopied by lithium exposure. We
recently demonstrated the presence of several polymorphisms in the IPPase
encoding inositol polyphosphate 1-phosphatase gene (INPP1) cDNA and suggested
that polymorphic variants of the human IPPase might be associated with the
striking difference in lithium response among bipolar patients. We report the
genomic structure and organization of the INPP1 gene on chromosome 2q32. Based on
DNA sequencing of the entire genomic region containing INPP1, we found that the
gene consists of six exons and spans more than 25 kb. Expression analysis showed
that INPP1 is present as a 1.9 kb mRNA transcript in all organs and tissues
examined, including the central nervous system. The level of expression varies,
with at least a fourfold higher transcript level in testis compared with other
tissues with high expression. A highly polymorphic dinucleotide repeat, (CA)18
25, with an observed heterozygosity of 0.86 was detected immediately downstream
of the gene. The present sequence information will be used to further investigate
the possible role of the INPP1 gene in lithium-treated bipolar illness.
PMID- 10780273
TI - Rapid high-performance liquid chromatographic method for determination of
debrisoquine and 4-hydroxy-debrisoquine in urine for CYP2D6 phenotyping.
PMID- 10780275
TI - Capitation and risk adjustment in health care.
AB - Capitation and risk adjustment have become the chosen policy instruments to seek
cost containment and equity of access for many developed health care systems.
Increasingly, this entails the prospective setting of global budgets for the
health care expenditures incurred by health care plans on behalf of their
members. Methods of deriving such budgets are diverse and tailored to the
specific circumstances of the health care system they seek to serve. This special
issue presents a collection of papers devoted to issues surrounding the
rationale, derivation, and implementation of capitation and risk adjustment
methods of financing health care. These are discussed within the context of
health care systems in eight countries, illustrating the range of interest in the
topic. Undoubtedly, capitation and risk adjustment will become increasingly
significant elements of virtually all systems of health care and we hope the
collection of papers will help to stimulate further debate and research in this
important and interesting area of health care financing.
PMID- 10780274
TI - Role of arylamine N-acetyltransferase 1 and 2 (NAT1 and NAT2) genotypes in
susceptibility to oral/pharyngeal and laryngeal cancers.
PMID- 10780276
TI - Capitation funding in Australia: imperatives and impediments.
AB - Health service funding mechanisms are pivotal in the pursuit of health system
objectives, as they provide strong financial incentives for actors in the system
to achieve policy goals. Underpinning funding mechanisms is a set of key economic
principles, or objectives, that should guide their design and use: efficiency,
equity, and accountability. The Australian health system has historically
performed relatively poorly in relation to these objectives, with evidence of
inefficiencies, inequities, and poor accountability in many areas of health
services. The primary cause of these shortcomings may lie in the complex set of
funding and delivery arrangements at the State and Federal levels of government.
Potentially significant improvements in the performance of the health system
would be available from the integration of the funding and delivery of services
within a single tier of government, coupled with the development of a national
weighted capitation approach to funding. To develop a national capitation funding
model a number of unique factors require consideration, including the current
fragmentation of services, the role of the private sector, the needs of
indigenous populations, and the effects of rurality. The data available to
develop a capitation model is of a level of detail and quality not readily found
elsewhere. If policy statements promoting efficiency, accountability, and
particularly equity are to be actively pursued, a national capitation model based
on robust methods should become a cornerstone of Australian health system reform.
PMID- 10780278
TI - Risk adjusting capitation: applications in employed and disabled populations.
AB - Risk adjustment may be a sensible strategy to reduce selection bias because it
links managed care payment directly to the costs of providing services. In this
paper we compare risk adjustment models in two populations (public employees and
their dependents, and publicly-insured low income individuals with disabilities)
in Washington State using two statistical approaches and three health status
measures. We conclude that a two-part logistic/GLM statistical model performs
better in populations with large numbers of individuals who do not use health
services. This model was successfully implemented in the employed population, but
the managed care program for the publicly insured population was terminated
before risk adjustment could be applied. The choice of the most appropriate
health status measure depends on purchasers' principles and desired outcomes.
PMID- 10780279
TI - Growing importance of capitation in Switzerland.
AB - Since its liberalization the Swiss health insurance market has shown risk
selection activities of the insurance funds, which call for risk adjustment.
Because risk selection continues to be profitable under the current risk
adjustment formula, fast growing HMO and PPO plans are (mis)used to attract good
risks rather than to contain costs. For fear of being replaced by one centralised
fund, social health insurers are themselves proposing improvements of the risk
adjustment formula, to be applied to funds. The revised formula proposed in this
paper, applicable among funds for risk adjustment and to gate-keeping models to
calculate fair capitation, explains 12.4% of the variance of health care
expenditure, halves profits from risk selection, and uses only the (few) data
that are available in Switzerland.
PMID- 10780277
TI - Needs-based primary medical care capitation: development and evaluation of
alternative approaches.
AB - OBJECTIVE: To develop and evaluate alternative methods of adjusting primary
medical care capitation payments for variations in relative need for health care
among enrolled practice populations. METHODS: We developed alternative needs
based capitation formulae and applied them to a sample of capitation-funded
primary care practices to assess each formula's performance against a reference
standard of capitation payments based on age, sex and self-assessed health status
of the enrolled populations. The alternative formulae were based on: (1) age and
sex; (2) age, sex and individually-measured socioeconomic characteristics; (3)
age, sex and socioeconomic characteristics imputed from census data for
enrollees' neighbourhood of residence; (4) age, sex and standardized mortality
ratio for enrollees' neighbourhood of residence. RESULTS: Age/sex-adjusted
capitation payments for the six practices studied ranged from 10% higher to 18%
lower than the reference standard payments. Capitation formulae based on
socioeconomic and mortality data did not perform consistently better than the
current age/sex-based formula. CONCLUSIONS: Primary medical care capitation
payments adjusted only for age and sex do not reflect the relative health care
needs of enrolled practice populations. Our alternative formulae based on
socioeconomic and mortality data also failed to reflect relative needs. Methods
that use other approaches to adjusting for differences in relative need among
enrolled populations should be investigated.
PMID- 10780280
TI - Risk adjustment and the fear of markets: the case of Belgium.
AB - In Belgium the management and administration of the compulsory and universal
health insurance is left to a limited number of non-governmental non-profit
sickness funds. Since 1995 these sickness funds are partially financed in a
prospective way. The risk adjustment scheme is based on a regression model to
explain medical expenditures for different social groups. Medical supply is taken
out of the formula to construct risk-adjusted capitation payments. The risk
adjustment formula still leaves scope for risk selection. At the same time, the
sickness funds were not given the instruments to exert a real influence on
expenditures and the health insurance market has not been opened for new
entrants. As a consequence, Belgium runs the danger of ending up in a situation
with little incentives for efficiency and considerable profits from cream
skimming.
PMID- 10780281
TI - Ignoring small predictable profits and losses: a new approach for measuring
incentives for cream skimming.
AB - Under inadequate capitation formulae competing health insurers have an incentive
for cream skimming, i.e., the selection of enrollees whom the insurer expects to
be profitable. When evaluating different capitation formulae, previous studies
used various indicators of incentives for cream skimming. These conventional
indicators are based on all actual profits and losses or on all predictable
profits and losses. For the latter type of indicators, this paper proposes, as a
new approach, to ignore the small predictable profits and losses. We assume that
this new approach provides a better indication of the size of the cream skimming
problem than the conventional one, because an insurer has to take into account
its costs of cream skimming and the (statistical) uncertainties about the net
benefits of cream skimming. Both approaches are applied in theoretical and
empirical analyses. The results show that, if our assumption is right, the
problem of cream skimming is overestimated by the conventional ways of measuring
incentives for cream skimming, especially in the case of relatively good
capitation formulae.
PMID- 10780282
TI - Modelling of resource allocation to health care authorities in Stockholm county.
AB - Since the Stockholm County Council introduced a system of purchasers and
providers there has been a quest for population-based resource allocation models
to allocate monies to purchasers of health care. In contrast to models used in
Britain, Swedish models have been based on individual level data. This paper
presents recent developments in the model used in Stockholm for all care except
primary care, testing new statistical methods for compression and clustering of
the matrices used and the effect of introducing diagnostic information in
addition to the demographic and socio-economic information used before. We also
show the effect of using more current data sources by replacing existing census
variables with data from annually updated registers. Since the aim is to use the
resource allocation models for prospective budgeting we test and evaluate the
predictive power of the models one to two years ahead. Moreover, two calibration
methods are compared: Cross-sectional modelling, based on data for one year only,
versus prospective modelling, using population characteristics for one year and
registered health-care costs for a following year. While models including
diagnostic information are deemed valuable, the prospective models yield little
improvement. Further, although it takes a combination of new variables to replace
the census based model, the resulting model now implemented by Stockholm County
Council has fewer estimated parameters.
PMID- 10780283
TI - Contract design for primary care physicians: physician location and practice
behaviour in small communities.
AB - Most western countries employ a combination of fee-for-service, fixed salary and
per capita subsidies to finance the services of general practitioners. Based on
Norwegian data, the authors demonstrate that these financial schemes have been
used in different types of municipalities. The authors argue that the fee-for
service and per capita components should be allowed to vary between primary
physicians and municipalities: (a) If the patient population per primary
physician is low and patient supply is unstable, the per capita subsidy or work
free income should be differentiated to ensure recruitment of physicians. (b)
Physicians in municipalities with low physician coverage should be allotted a low
basic grant, whilst per capita subsidy and fee-for-service payments should be
used to stimulate service production. The opposite situation exists where there
is a potential of supplier inducement due to high physician coverage. (c) The
responsibility for designing contracts should be assigned to local rather than
national authorities. These suggestions go against important elements in the
reform of primary physician services in Norway.
PMID- 10780284
TI - Risk adjustment of capitation payments to behavioral health care carve-outs: how
well do existing methodologies account for psychiatric disability?
AB - This study used 1994-1995 administrative data from a large public employer to
examine the viability of commercial risk adjustment systems for setting
capitation payments to competing behavioral health care "carve-outs". The ability
of Hierarchical Condition Categories and Adjusted Diagnostic Groups to predict
psychiatric expenditures was improved by controlling separately for psychiatric
disability. However, even the best models underpredicted expenditures of patients
with psychiatric disability by 15%. Relative to full capitation, "mixed" payment
systems and soft capitation reduce the ability of carve-outs to earn
disproportionate profits by enrolling healthy patients and avoiding sick ones,
yet also diminish incentives for cost containment.
PMID- 10780285
TI - Differential involvement of dopamine in mediating the discriminative stimulus
effects of low and high doses of caffeine in rats.
AB - The hypothesis that low and high doses of caffeine produce effects that are
differentially mediated by dopamine (DA) receptor mechanisms was investigated in
rats trained to discriminate either 10 or 56 mg/kg of caffeine from saline. Rats
trained to discriminate 56 mg/kg of caffeine acquired the discrimination in an
average of 74 sessions, whereas rats trained to discriminate 10 mg/kg of caffeine
required an average of 108 sessions. The DA D1 receptor agonist SKF 81297 and the
DA D2 receptor agonist R(-)-propylnorapomorphine (NPA) generalized partially (50
75%) in rats trained to discriminate 10 mg/kg of caffeine, but produced
predominantly saline-appropriate responding (< 40%) in rats trained to
discriminate 56 mg/kg of caffeine. When SKF 81297 and NPA were combined, stimulus
generalization was no greater than it was when either agonist was tested alone.
The DA uptake inhibitors cocaine and GBR 12909 produced predominantly saline
appropriate responding in both groups of rats. Neither the DA D1 receptors
antagonists SCH 23390 and SCH 31966, nor the DA D2 receptor antagonists
eticlopride and sulpiride, generalized in rats trained to discriminate 10 or 56
mg/kg of caffeine. When administered in combination with caffeine, both the DA D1
and DA D2 antagonists antagonized completely the discriminative stimulus effects
of the low training dose of caffeine, but did not alter the discriminative
stimulus effects of the high training dose. These results suggest that the
discriminative stimulus effects of 10 mg/kg of caffeine, but not 56 mg/kg of
caffeine, are dependent on, but not limited to, DA D1 and D2 receptor mechanisms.
PMID- 10780286
TI - Assessment of D3 versus D2 receptor modulation of the discriminative stimulus
effects of (+)-7-OH-DPAT in rats.
AB - Although there are presently no highly selective agonists for the D3 dopamine
receptor, a number of compounds reported to bind with moderate selectivity to D3
receptors are currently employed to investigate the importance of D3 receptors in
the behavioral effects of psychostimulant drugs. For example, 7-hydroxy-N,N-di-n
propyl-2-aminotetralin (7-OH-DPAT) has been used extensively to investigate the
role of D3 receptors in the reinforcing and discriminative stimulus properties of
cocaine and d-amphetamine. However, recent investigations with a relatively
selective D3 antagonist, PNU-99194A, have led us to question the importance of D3
receptors in the discriminative stimulus effects of 7-OH-DPAT. In the present
study, 16 male Sprague-Dawley rats were trained to discriminate (+)-7-OH-DPAT
(0.03 mg/kg, subcutaneously (s.c.)) from saline in a two-choice operant procedure
using a fixed-ratio 20 schedule of water reinforcement. Consistent with previous
findings, PNU-99194A appeared to attenuate only partially (+)-7-OH-DPAT
discrimination at a dose that disrupted responding in most subjects. Moreover, a
highly selective D2 agonist, PNU-91356A, substituted completely and in a dose
dependent manner for (+)-7-OH-DPAT, while d-amphetamine produced only partial
substitution for the training drug. These data indicate that D2 receptor actions
appear to be more important than D3 receptor actions in exerting the
discriminative stimulus effects of (+)-7-OH-DPAT. Continued efforts to determine
the relative importance of D2 vs D3 receptor actions in the modulation of the
discriminative stimulus effects of (+)-7-OH-DPAT are discussed.
PMID- 10780287
TI - Effects of post-training infusions of a mitogen-activated protein kinase kinase
inhibitor into the hippocampus or entorhinal cortex on short- and long-term
retention of inhibitory avoidance.
AB - We recently demonstrated the time-dependent impairment of long-term retention of
a step-down inhibitory avoidance task in rats induced by post-training infusion
of the specific MAPKK (mitogen-activated protein kinase kinase) inhibitor PD
098059 into the hippocampus (HIP), amygdala (AMY), entorhinal cortex (EC) and
posterior parietal cortex (PPC). Here we investigate the role of the MAPK cascade
in the HIP and the EC on both short- and long-term retention of inhibitory
avoidance in rats, using three different doses of the MAPKK inhibitor PD 098059.
Adult male Wistar rats were trained and tested in inhibitory avoidance and given
an infusion of PD 098059 (0.5, 5.0 or 50.0 microM) at 0, 30, 90, 120, 180, 270 or
360 min after training. A retention test session was carried out at 90, 180 or
270 min after training (short-term memory, STM) and/ or 24 h after training (long
term memory, LTM). When infused into the HIP at 0 min, but not at 30, 90, 120 or
180 min after training, PD 098059 impaired STM. Intrahippocampal PD 098059
impaired LTM when infused at 180 min, but not at 0, 30, 90, 120 or 270 min after
training. When infused into the EC, PD 098059 enhanced STM when given at 0 min
after training and had no effect when given at 30, 90, 120 or 180 min after
training. In this structure, PD 098059 impaired LTM when given at 180 or 270 min,
but not at 30, 90, 120 or 360 min after training. All effects were dose
dependent. These findings indicate that the MAPK cascade in the HIP and EC is
differentially involved in short- and long-term retention of inhibitory avoidance
in rats.
PMID- 10780288
TI - Effects of sildenafil on long-term retention of an inhibitory avoidance response
in mice.
AB - Sildenafil (1, 3, 10, and 30mg/kg, intraperitoneally (i.p.)), a cyclic guanosine
monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5) inhibitor,
facilitated retention performance of a one-trial step-through inhibitor avoidance
task, when administered to male Swiss mice immediately after training, as
indicated by performance on a retention test 48 h later. The dose-response curve
was an inverted U in this dose range, although only the dose of 3 mg/kg of
sildenafil produced significant effects. Sildenafil did not affect response
latencies in mice not given the footshock on the training trial, indicating that
the actions of sildenafil on retention were not due to non-specific proactive
effects on retention performance. The effects of sildenafil (3 mg/kg, i.p.) were
time-dependent, and the administration of sildenafil (3 mg/kg, i.p.) 30 min prior
to the retention test did not affect retention in mice given post-training
injections of vehicle or sildenafil (3 mg/kg, i.p.). However, the administration
of sildenafil (3mg/kg, i.p.) 30 min before training also enhanced retention
performace. Further, when mice were trained and received immediate post-training
sildenafil (3 mg/kg) and were tested for retention either 1 week or 1 month
later, at each retention interval the performance was comparable to that found
with a 48-h retention interval. Finally, an enhancement of retention was also
observed in female Swiss mice that received sildenafil (3 mg/kg, i.p.)
immediately, but not 180min, after training. These findings could indicate that
the actions of sildenafil on retention are not sex-dependent. The results suggest
that sildenafil influences retention by modulating time-dependent mechanisms
involved in memory storage and that the effects are long lasting. A possible
participation of the nitric oxide (NO)-guanylyl cyclase-cGMP system also is
suggested.
PMID- 10780289
TI - Dose-dependent effects but not sensitization of DRL 45-s performance by oral d
amphetamine with cumulative- and repeated-dosing regimens.
AB - The effects of d-amphetamine (AMPH) on a food-reinforced DRL 45-s schedule were
evaluated using both cumulative- and repeated-dosing drug regimens. These two
dosing regimens were designed to evaluate sensitization as a shift in the dose
response relationship, inasmuch as a range of doses was imposed within each
dosing session. Daily 190-min sessions were composed of five 35-min subsessions
separated by 3-min time-out periods. For selected sessions, five cumulative or
repeated oral doses of AMPH were administered across the session, with a dose
given during each of the time-out periods prior to the start of each subsession.
Drug sessions were separated by intervals of 7-l0 days of non-drug sessions. Four
cumulative dose-effect functions for AMPH were determined: for each dose-effect
determination session, increasing doses (0.5, 1, 2, 4, 8 mg/kg gavage) were
successively administered prior to each subsession. Four dose-effect functions
were then determined in which a 0.5 mg/kg AMPH dose was repeated for each
subsession (repetitive-dose regimen) rather than escalating subsession dose size.
Then, four additional functions were determined using a larger repetitive dose of
1 mg/kg AMPH. Cumulative doses resulted in a leftward shift in the inter-response
times (IRT) distribution accompanied by dose-dependent increases in subcriterion
responses (< 45 s) and decreases in reinforced responses. The repeated doses of
0.5 or 1 mg/kg AMPH also resulted in progressive intrasession increases in
subcriterion responses and decreases in reinforced responses. Although
intrasession, accumulating dose effects were evident and statistically
significant, there was no statistical significance or trend supporting
sensitization of differential reinforcement of low-rate (DRL) responding with
either cumulative- or repeated-dosing regimens across drugging sessions, unlike a
previous, similar study in which oral cocaine resulted in robust sensitization.
PMID- 10780290
TI - Regulation of emotional behaviour by day length in mice: implication of
melatonin.
AB - Pineal melatonin secretion occurs at night in all vertebrates and the duration of
its secretion is negatively correlated with day length. As short-day exposure was
previously shown to decrease emotional behaviour of mice toward an unfamiliar
environment, the present study was designed to determine whether such behavioural
changes could be mediated by melatonin. In a first experiment, the effects of a 3
week exposure to various day lengths (18h-6h, 12h-12h and 6h-18h light-dark
conditions) on neophobic behaviour (free-exploratory paradigm) were examined in
both BALB/c mice, which exhibit a very transitory melatonin peak of low amplitude
in a 12h light-12h dark cycle, and C3H/He mice, which present a clear melatonin
rise during the night-time. A second experiment was designed to determine if the
decrease of emotional reactivity induced by a short-day exposure (6h-18h light
dark cycle during 3 weeks) in C3H/He mice could be counteracted by a daily
treatment with a melatonin antagonist, S 22153 (1, 5 and 25 mg/kg/day). The short
day exposure was found to decrease neophobic reactions in both C3H/He and BALB/c
mice. In contrast, the long-day exposure enhanced neophobia in C3H/He mice only.
S 22153 was found to counteract, in a dose-dependent manner, the anxiolytic-like
effects induced by the short-day exposure in C3H/He mice. The present results
provide evidence that the modulation of circulating melatonin could be involved
in the emotional changes related to day-length variations. Further studies are
needed to investigate whether pinealectomy could counteract the photoperiod
related changes in anxiety.
PMID- 10780291
TI - Behavioural consequences of repeated social defeat in the mouse: preliminary
evaluation of a potential animal model of depression.
AB - The behavioural consequences of repeated social defeat, coupled with the stress
of continuously living opposite a dominant animal, were assessed in male NMRI
mice. The method adopted here differed from the previously published techniques
in that the physical element of the social defeat procedure was reduced to a
minimum. The subordinate animals consistently weighed less than control animals,
and displayed a reduced number of visits to the partition compared to the
dominant animals, which has previously been used as a marker of social behaviour.
The subordinate animals did not show any differences in the amount of ethanol
solution consumed compared to controls, and did not display an increase in
immobility time measured in the forced swimming test. The subordinate animals
did, however, display anxiogenic-like behaviour as indicated by an increased
aversion of the light section of the black/white test box, which was partially
reversed by chronic treatment (3weeks; 20mg/kg/day) with the antidepressant,
citalopram. Decreased exploration by the subordinate animals in the black/white
test box was also observed, which was reversed by chronic citalopram treatment.
It is suggested that, whilst the model requires further validation, it may be a
useful approach for the study of antidepressant compounds.
PMID- 10780292
TI - Effects of drugs on responding under concurrent fixed-interval schedules and
concurrent fixed-ratio schedules.
AB - Pigeons were trained to respond under concurrent fixed-interval fixed-interval
(concurrent FI FI) schedules with Fl values (in seconds) of 30/300, 60/240,
60/60, 240/60 and 300/30. A second group was trained to respond under concurrent
fixed-ratio fixed-ratio (concurrent FR FR) with FR values of 10/40, 10/20, 20/20,
20/10 and 40/10. Under the concurrent Fl Fl schedules, pigeons responded much
less often on the key with the higher reinforcement density than would be
predicted basing on a perfect matching of the ratio of responses made to the
ratio of reinforcers delivered, and the pigeons also showed a bias towards
responding on the left key. Pentobarbital, methamphetamine, morphine and
phencyclidine had little effect on bias, but high doses of methamphetamine,
morphine and phencyclidine decreased undermatching. Under the concurrent FR FR
schedules, pigeons responded almost entirely on the key with the higher
reinforcement density. Only pentobarbital consistently disrupted this pattern of
responding.
PMID- 10780293
TI - Effects of phentermine on responding maintained by progressive-ratio schedules of
cocaine and food delivery in rhesus monkeys.
AB - Previous reports indicate that intravenous pretreatment with phentermine can
decrease cocaine-maintained responding without affecting food-reinforced
responding under fixed-ratio schedules. The present experiments were designed to
explore the generality of this effect using progressive-ratio schedules of
reinforcement and different routes of phentermine administration. Unit doses of
cocaine and food-pellet magnitudes were identified that maintained similar
breaking points, and the effects of acute exposure to phentermine were assessed.
In Experiment 1, a 'conventional' (one-trial) progressive-ratio schedule was
used, in which response requirements increased after each reinforcer delivery; in
Experiment 2, a 'modified' (five-trial) progressive-ratio schedule was used, in
which response requirements increased after every five reinforcer deliveries. In
one group of monkeys, responding was maintained by food; in another, cocaine
infusions maintained responding. Phentermine (0.1-5.6mg/kg, intramuscularly
(i.m.)) dose-dependently decreased breakpoints on both progressive-ratio
schedules. There were no differences in phentermine's effects on cocaine- and
food-maintained behavior. In Experiment 3, intravenous administration of
phentermine had largely similar effects. Taken together with results from
previous reports, these data suggest that the effects of phentermine pretreatment
are influenced by the behavioral procedure used to maintain responding and/or by
the efficacy of the food and cocaine reinforcers.
PMID- 10780295
TI - The calcium channel antagonist, nimodipine, decreases operant self-administration
of low concentrations of ethanol.
AB - This study examined effects of the dihydropyridine calcium channel antagonist,
nimodipine, on operant self-administration of ethanol, under a progressive-ratio
schedule of reinforcement, by hooded Lister rats. Calcium channel antagonists
have been reported to decrease the ethanol withdrawal syndrome, the development
of tolerance to ethanol and ethanol consumption; and dihydropyridine binding site
density in the central nervous system (CNS) is increased by chronic alcohol
treatment. In addition, these drugs decrease reinforcing effects of
psychostimulants. In the present studies, nimodipine was administered, once
weekly, at either 10 or 50 mg/kg intraperitoneally (i.p.). At 10 mg/kg,
nimodipine decreased the break point, and number of reinforcers obtained, for
ethanol concentrations of 5, 10 and 15%. At 50mg/kg, nimodipine only decreased
the break point, and number of reinforcers, for 5% ethanol. Responding for higher
concentrations of ethanol was unaffected by nimodipine, as was responding when
ethanol was replaced by water. The break point for 10% sucrose, but not for 1% or
0.1%, was decreased by 50 mg/kg nimodipine, but 10 mg/kg nimodipine had no effect
on sucrose-reinforced responding. The 50 mg/kg dose of nimodipine decreased motor
activity, but 10 mg/kg nimodipine only slightly decreased static activity counts.
The results suggest that nimodipine, at the lower dose tested, decreased the
reinforcing properties of low concentrations of ethanol.
PMID- 10780294
TI - Influence of light cycle on response to 5-HT1A ligands in punished responding in
rats.
AB - Since the introduction of buspirone, the 5-HT1A receptor has been a focal point
for serotonergic research into the treatment of anxiety. Two of the more commonly
used methodologies for evaluating potential anxiolytics are the Geller-Seifter
model and the elevated plus maze. In the Geller-Seifter model, administration of
5-HT1A agonists produce an anxiolytic-like profile consisting of an increase in
the number of responses made during the punished component. An anxiolytic-like
response in the elevated plus maze consists of an increase in the number of
entries and/or time spent in the open arms of the maze. Recently, there have been
reports of differential drug effects with 5-HT1A ligands in the elevated plus
maze depending on when in the diurnal cycle the 5-HT1A agents were administered.
The purpose of the current study was to characterize the response to 5-HT1A
compounds in normal and reverse light cycle animals in the Geller-Seifter model.
8-OH-DPAT [(+/-)-2-dipropylamino-8-hydroxy-1,2,3,4-tetrahydronapthalene] produced
a decrease in unpunished responding and an increase in punished responding during
both the light and dark phase. The administration of WAY 100,635 [N-?2-[4-(2
methoxyphenyl)-1-piperazinyl] ethyl?-N-(2-pyridinyl)cyclohexanecarboxamide
trihydrochloridel alone was without effect in both the light and dark phase.
Furthermore, pre-treatment with WAY 100,635 completely antagonized both the rate
decreasing effects in the unpunished component and the increase in punished
responding observed with 8-OH-DPAT during both the light and dark phase. The
results of the current study diverge from previous findings of sensitivity to the
diurnal cycle in other models reflective of modulation of the 5-HT1A receptor.
The robustness of the response, in this case punished lever pressing, may be less
sensitive than other more naturalistic or ethological methods (i.e. elevated plus
maze) in detecting the subtle changes in receptor function due to the diurnal
cycle.
PMID- 10780296
TI - Establishing preference for lidocaine solution to water: comparison between a
fading and an abrupt-removal procedure for withdrawing a compound vehicle.
AB - Rats were exposed to daily, 3-h, fixed-time 1-min food-pellet delivery sessions,
which is a procedure that produces overdrinking (schedule-induced polydipsia). In
previous polydipsia studies, rats came to prefer solutions of drug or non-drug
agents to concurrently presented water if the agents had first been offered in a
glucose-saccharin vehicle that was slowly eliminated (faded), leaving a choice
between a substance in water vehicle vs water. In the first experiment, a more
rapid vehicle-fading procedure was used to produce a preference for 0.19mg/ml
lidocaine to water. In the second experiment, the vehicle was abruptly changed to
water, which also resulted in a strong preference for lidocaine solution,
although the lidocaine solution volumes ingested for the final sessions were
significantly less than in the first experiment. The results are consistent with
a conditioned flavor/nutrient preference interpretation for the institution of
the lidocaine preference in both experiments. Although flavor/nutrient
conditioning can be a sufficient condition for generating a substance preference,
a previous experiment showed that it was not a necessary condition.
PMID- 10780297
TI - Lack of difference between HAD and LAD rats in the stimulus generalization of
ethanol to nicotine.
AB - High alcohol drinking (HAD) and low alcohol drinking (LAD) rats were trained to
discriminate 0.5 g/kg ethanol from saline. HAD and LAD rats learned the
discrimination at the same rate and to the same level of asymptotic performance.
In substitution tests, increasing doses of ethanol produced increased responding
on the ethanol lever with dose-effect curves that were very similar in HAD and
LAD rats. There was no generalization from ethanol to nicotine, or d-amphetamine,
in either HAD or LAD rats. These data may be contrasted with data obtained with
alcohol preferring rats (P rats) and alcohol non-preferring rats (NP rats), where
the ethanol discrimination was learned more rapidly, asymptotic performance was
better in P than in NP rats, and ethanol discriminative stimulus generalized to
nicotine and partially to d-amphetamine in P, but not in NP rats. These data
suggest that the differences in ethanol consumption reported previously by P and
HAD rats relative to NP and LAD rats is not necessarily related to strain
differences in ethanol discrimination as the differences in ethanol
discrimination previously observed between P and NP rats do not occur in HAD and
LAD rats.
PMID- 10780298
TI - Naltrexone and morphine alter the discrimination and plasma levels of ethanol.
AB - The opioid antagonist, naltrexone, reduces intake of, and operant responding for,
ethanol, but reports of how the opioid agonist morphine alters these effects are
conflicting. We examined the discrimination and plasma levels of ethanol with
naltrexone and morphine pretreatments. Rats were trained to discriminate ethanol
(1.5 g/kg; i.g.) from water, under a two-lever, food-reinforced procedure.
Ethanol and pentobarbital, but not amphetamine, substituted for ethanol in a dose
related manner. Naltrexone reduced ethanol-induced, ethanol-appropriate
responding to about 35%, but the peripherally-acting antagonist, naltrexone
methobromide, was without effect. Morphine neither substituted for nor enhanced
ethanol-appropriate responding. Rather, ethanol-induced, ethanol-appropriate
responding was attenuated in a dose-related manner by morphine administration.
Neither naltrexone nor morphine altered ethanol-appropriate responding to the
substitution with pentobarbital. In another group of rats, both naltrexone and
morphine decreased plasma ethanol levels, and delayed the time of peak
concentrations, suggesting that opiates alter the behavioral effects of ethanol
through both pharmacokinetic and pharmacodynamic mechanisms. The similarities
between an opioid agonist and an antagonist suggest that either naltrexone has
opioid agonist-like effects, or that these effects occur through non-opioidergic
mechanisms.
PMID- 10780299
TI - Sensitization of operant behavior to oral cocaine with increasing- and repetitive
dose regimens.
AB - This study evaluated whether operant behavior was subject to sensitization upon
repeated exposure to cocaine. The behavior of eight rats was reinforced by food
pellet delivery under a differential reinforcement of low-rate (DRL) 45-s
schedule, in daily sessions of 190 min. Each session was composed of five 35-min
subsessions, with each subsession preceded by a 3-min time out period (TO). For
selected sessions, a cumulative dose-effect relation for cocaine, using
increasing doses, was first determined by oral gavage administration of a dose
during each subsession. Three such cycles were given, separated by between seven
and ten sessions. Later, four further cycles were given, using a repetitive 10
mg/kg cocaine per os (p.o.) dose, rather than an increasing dose. Under both
dosing procedures, within a cocaine cycle (session), shorter (<45 s) inter
response times (IRT) progressively increased with doses, and reinforced responses
decreased. As cycles were repeated, the shorter IRT increases became
progressively more marked, indicating the development of sensitization to the
effect of cocaine. With the second procedure (repetitive 10 mg/kg doses),
reinforcement rate decreases became more marked as cycles were repeated, but this
change did not occur using the increasing-dose procedure. Upon later exposure to
repetitive 5 mg/kg dosing cycles, none of these rate changes occurred, and
performances were equivalent to those occurring under saline cycles. Exposure to
cumulative dose regimens of oral cocaine can result in the sensitization of
operant behavior to the effects of cocaine.
PMID- 10780300
TI - Establishing oral preference for quinine, phencyclidine and caffeine solutions in
rats.
AB - Rats were given fixed-time, 1-min food-pellet delivery sessions, for 3 h every
day, which resulted in over drinking (schedule-induced polydipsia). In previous
research, groups of animals came to prefer solutions of cocaine or lidocaine to
concurrently presented water, if the drugs were first offered in a
glucose/saccharin vehicle, which was then gradually eliminated, so that the
choice became a drug solution in water vehicle versus water. In the present
experiment, the same procedure produced a preference for 0.025 mg/ml quinine
solution to water, indicating that a bitter solution that was not a topical
anesthetic agent could come to be preferred. After establishing preference for
quinine solution, it was possible to gradually remove quinine while increasing
phencyclidine (PCP) concentration to produce preference for 0.075 mg/ml PCP
solution, and similarly to produce subsequent preference for 0.1 mg/ml caffeine
solution, although not for all animals. For additional groups, drinking either
0.15 mg/ml PCP or 0.1 mg/ml caffeine, while gradually reducing the
glucose/saccharin vehicle to water vehicle was a less successful procedure for
establishing the respective drug preferences. The latter result suggests that
first instituting a preference for quinine solution to water facilitated the
later establishment of preferences for PCP and caffeine solutions.
PMID- 10780301
TI - Discriminative-stimulus effects of triazolam and midazolam in rhesus monkeys.
AB - The present study characterized the discriminative-stimulus effects of triazolam
and midazolam in rhesus monkeys. Six monkeys discriminated 0.1 mg/kg of triazolam
from vehicle under a fixed-ratio 5 (FR 5) schedule of stimulus-shock termination
(SST). Four monkeys subsequently discriminated 0.56 mg/kg of midazolam from
vehicle under the same schedule of reinforcement. Benzodiazepine (BDZ) agonists
midazolam and diazepam, and the barbiturate pentobarbital, substituted for
triazolam, and the non-competitive N-methyl-D-aspartate (NMDA) antagonist
ketamine did not. Triazolam, diazepam, lorazepam, flunitrazepam, as well as the
barbiturates amobarbital and pentobarbital, substituted for midazolam, and
ketamine did not. The BDZ antagonist flumazenil antagonized both the triazolam
and midazolam discriminative stimuli. Bretazenil, a low-efficacy BDZ agonist, did
not substitute for the midazolam discriminative stimulus in three of the monkeys
and shifted the midazolam dose-effect curve to the right; in a fourth monkey,
bretazenil substituted for midazolam and shifted the midazolam dose-effect curve
to the left. Schild analyses with flumazenil or bretazenil, in combination with
midazolam, yielded slopes that deviated significantly from unity. While clearly
supporting the notion that BDZ agonists produce stimulus effects by acting at the
gamma-aminobutyric acidA (GABA(A)) receptor complex, these data also suggest that
the discriminative-stimulus effects of midazolam might be mediated by more than
one BDZ receptor subtype.
PMID- 10780302
TI - Prepulse inhibition of the startle reflex in rats: effects of compounds acting at
various sites on the NMDA receptor complex.
AB - Prepulse inhibition (PPI) of the startle reflex in rats is disrupted by N-methyl
D-aspartate (NMDA) receptor non-competitive antagonists (phencyclidine-like
compounds). In order to explore more thoroughly the control exerted by NMDA
receptors on PPI, we assessed the effects of i.p. administration, in Sprague
Dawley rats, of compounds acting as antagonists or agonists at the five binding
sites of the NMDA receptor complex. The non-competitive NMDA receptor antagonists
phencyclidine (1-6 mg/kg) and MK-801 (dizocilpine: 0.05-0.2 mg/kg) robustly and
dose-dependently disrupted PPI. A similar effect was obtained with the
competitive NMDA receptor antagonists CGS 19755 (1-20 mg/kg) and CPP (3-20
mg/kg), but not with the cation Mg2+ (100 and 200 mg/kg), the glycine/NMDA
binding site antagonist L-701,324 (1-10 mg/kg), or the polyamine/NMDA binding
site antagonist eliprodil (3-20 mg/kg). Potentiation of glutamatergic
neurotransmission by NMDA (10-50 mg/kg), and the glycine/NMDA site partial
agonist d-cycloserine (1-30 mg/kg) also failed to modify PPI, though d
cycloserine diminished PPI at higher doses (50-200 mg/kg). Co-administration of
sub-threshold doses of CPP (3 mg/kg) and phencyclidine (2 mg/kg) resulted in an
additive effect, disrupting PPI. In contrast, co-administration of L-701,324 (6
mg/kg) with phencyclidine (2 mg/kg), eliprodil (20 mg/kg), or CPP (3 mg/kg), did
not disrupt PPI. These results demonstrate that PPI-disrupting effects can only
be obtained with phencyclidine-like compounds and NMDA receptor competitive
antagonists. Treatment with compounds that potentially augment glutamatergic tone
were without effect. Finally, despite the permissive control of the glycine/NMDA
binding site on glutamatergic neurotransmission, the glycine/NMDA binding site
antagonist L-701,324 did not produce synergistic activity when combined with
antagonists at the glutamate, polyamine/NMDA or phencyclidine-like compound
binding sites.
PMID- 10780303
TI - The non-competitive NMDA receptor blocker dizocilpine potentiates serotonergic
function.
AB - Forepaw treading induced in rats by the 5HT1A agonist 8-OH-DPAT, and head shakes
caused by the administration of the 5HT2A receptor against DOI, and by the 5HT
precursor (-)5HTP, were significantly increased by pretreatment with the non
competitive N-methyl-D-aspartate (NMDA) antagonist dizocilpine. Dizocilpine
administration also significantly increased the locomotor activity induced by the
serotonin agonists. The competitive NMDA receptor antagonist CGP 43487 increased
only the head shakes induced by DOI, but did not alter the behavior elicited by 8
OH-DPAT, or (-)5HTP, and did not modify locomotor responses to any of the
agonists used. The dizocilpine-induced potentiation of head shakes elicited by
DOI and (-)5HTP was inhibited by the 5HT2 agonist ketanserin, but was not
modified by the selective dopamine D1 and D2 receptor blockers SCH 23390 and (
)sulpiride. The dopamine receptor antagonists did, however, counteract the
dizocilpine facilitation of both forepaw treading induced by 8-OH-DPAT, and the
locomotor response to all the serotonergic agonists. The results indicate that,
unlike competitive NMDA receptor antagonists, the non-competitive antagonists
enhanced the expression of serotonergic stimulation, and suggest that a glutamate
deficiency could contribute to the pathogenesis of schizophrenia, not only
through dopaminergic, but also through serotonergic, hyperactivity.
PMID- 10780304
TI - The effects of melatonin on the behavioural disturbances induced by chronic mild
stress in C3H/He mice.
AB - In rodents, exposure to chronic mild stress (CMS) is known to induce
unresponsiveness to environmental stimuli, as well as sleep disturbances,
suggesting some analogies between this syndrome and human depression.
Furthermore, numerous studies reported a decrease in nocturnal melatonin
concentration in depressed patients, compared with controls. The present study
was conducted to test a possible preventative action of daily treatment with
melatonin on behavioural alterations induced in C3H/He mice by CMS exposure. In
addition to daily spontaneous locomotor activity and preference for sucrose
solution, the emotional behaviour of mice was examined in a stressful situation
(light/dark choice test), as well as in a situation devoid of constraining
components (free-exploratory paradigm), after three weeks of CMS. The results
showed that the behaviour of C3H/He mice was disrupted after CMS. Stressed mice
exhibited blunted emotional reactivity in both the light/dark choice test and the
free-exploratory situation. While unstressed mice presented no variation in their
preference for a sucrose solution, stressed mice presented a decrease in such
preference towards the end of the CMS exposure. Furthermore, daily spontaneous
locomotor activity of the mice was reduced after CMS. Daily treatment of stressed
mice with melatonin was able to prevent several CMS-induced disturbances, except
in the light/dark choice test, where melatonin was ineffective. Compared to the
effects of 10 mg/kg of fluoxetine, which completely prevented CMS-induced
dysregulation of behaviour, melatonin was less effective. The present results
support the idea that melatonin may be implicated in an homeostatic system which
protects animals from disruptions induced by chronic stress.
PMID- 10780305
TI - Modifications of the behavioral profile of non-competitive NMDA receptor
antagonists, memantine, amantadine and (+)MK-801 after chronic administration.
AB - Non-competitive N-methyl-D-aspartate (NMDA) receptor antagonists show
antiparkinsonian-like activity in animal models, and possess neuroprotective
properties. However they also induce a number of behavioral side effects in
rodents at higher doses; these include learning impairment, hyperlocomotion, and
ataxia. The present study focused on the possible development of tolerance, or
sensitization, to any of these effects after sustained administration, either by
repeated injection or continuous infusion. When memantine or (+)MK-801 (20 and
0.31 mg/kg/day respectively) were either infused or repeatedly injected for 14
days, tolerance was observed to their learning impairing effect at high doses, in
a passive avoidance test. Tolerance to their ataxic effect developed after
repeated administration ((+)MK-801 and memantine), or after infusion (memantine).
Sensitization to the locomotor stimulation was seen following repetitive
injections of memantine for 14 days, but not seen with (+)MK-801. In animals with
an unilateral 6-OHDA lesion of the nigrostriatal system, acute administration of
memantine caused ipsilateral rotations, which were augmented following 14 days of
infusion. The potency of amantadine to antagonize neuroleptic-induced catalepsy
was unchanged following either infusion or repeated injections. The various acute
effects of non-competitive NMDA receptor antagonists were modified differently by
sustained treatment (i.e. tolerance to learning impairment and ataxia;
sensitization to memantine's locomotor stimulation). The anti-cataleptic activity
of amantadine remained unaltered. However, differences between drugs and the two
treatment regimens (i.e. repetitive versus continuous treatments) were apparent.
PMID- 10780306
TI - Intra-hippocampal KN-62 hinders the memory of habituation acquired alone, but not
simultaneously with a water-finding task.
AB - Rats were implanted bilaterally with cannulae in the CA1 region of the dorsal
hippocampus. After recovery from surgery, they were submitted to a water-finding
task, which required detecting a water tube in an open field, and then
remembering its location under conditions of thirst. This task was acquired
simultaneously with habituation to the open field. Training and test sessions
lasted 2 min, in addition to the time spent at the water tube. The training-test
interval was 24 h, during which the animals were deprived of water. Immediate
post-training intra-hippocampal administration of the calcium/calmodulin
dependent protein kinase II (CaMKII) inhibitor KN-62 (3.6 ng/side) attenuated
memory of the water-finding task, but not that of the habituation acquired
concomitantly. However, when the habituation was carried out alone in the absence
of the water-finding task, its retention was inhibited by KN-62. Thus, depending
on circumstances, habituation can be memorized with or without hippocampal CaMKII
activity. In the post-training period, CA1 neurones appear to 'choose' which task
will be processed by a metabolic pathway that includes CaMKII.
PMID- 10780307
TI - Haloperidol-induced within-session response decrement patterns and catalepsy in
rats: behavioural dissociation.
AB - The typical antipsychotic haloperidol is known to induce extra-pyramidal side
effects (EPS). Catalepsy in rats is generally regarded as a valid model for
detecting the EPS liability of compounds in humans. Together with its
antipsychotic and cataleptogenic actions, haloperidol causes an attenuation of
instrumental responding which becomes larger in the course of a session: a within
session response decrement. The present study compared the time-course of
haloperidol-induced catalepsy, measured by a bar test, to the haloperidol-induced
within-session response decrements, measured by operant behaviour under a fixed
ratio 10 schedule of reinforcement. Rats were trained to press a lever on a Fixed
Ratio 10 schedule of food reinforcement during sessions of 15 min. When
responding was stable, saline or haloperidol in 0.03 mg/kg, 0.1 mg/kg, or 0.3
mg/kg was administered intra-peritoneally either 30, 90 or 180 min prior to
behavioural testing. The number of lever presses, food tray visits and latency to
press the lever and to visit the food tray were analysed in five successive
blocks of 3 min. Catalepsy was tested 30, 60, 90, 120, and 180 min. after
injection, by placing a rat with its forepaws on a horizontal bar. The latency to
remove both forepaws from the bar was scored. Within-session response decrements
were present at 0.1 mg/kg and at 0.3 mg/kg, from 30 min after administration
onward. At these doses, latency to press the lever was increased after 30 and 90
min, but not significantly after 180 min. Latency to visit the tray was affected
only after 30 min, at 0.3 mg/kg. Haloperidol induced a dose-dependent increase in
catalepsy from 60 min onwards, with maximal effect after 120 min. A dissociation
between the time-course of occurrence of within-session response decrement and
the cataleptogenic action of haloperidol, as well as between the latter and both
latency measures, was found. Consequently, the present data suggest that within
session response decrements are not obviously caused by catalepsy-related
impairments.
PMID- 10780308
TI - Post-session intra-perifornical region quinpirole infusions retard the
consolidation of an appetitive differential conditioning task.
AB - We have shown previously that post-session infusions of the D2/D3 dopamine
receptor antagonist sulpiride within the perifornical region of the lateral
hypothalamus (PFH) greatly facilitated the acquisition of an appetitive
differential conditioning task. Here, we have examined the effects of the D2/D3
dopamine receptor agonist quinpirole on acquisition of this task. Conditioning
sessions consisted of an initially neutral stimulus (CS+) preceding availability
of a 10% sucrose reward (US), and a control stimulus (CS-), never associated with
the US, were presented, followed by bilateral intra-PFH infusions of quinpirole
(0, 0.1, 10 nmol). The acquisition of a conditioned approach response during the
CS+ period was impaired by quinpirole administration in a dose-dependent manner.
No other behavioural measure was affected. All groups subsequently acquired the
conditioned approach response, following cessation of the post-session infusion
procedure. The present data extends previous findings, suggesting that the level
of activation of dopamine receptors in the vicinity of the PFH significantly
influences the consolidation of appetitive Pavlovian associations.
PMID- 10780309
TI - A new paradigm for blood coagulation research.
PMID- 10780310
TI - A comparative double-blind, randomised trial of a new second generation LMWH
(bemiparin) and UFH in the prevention of post-operative venous thromboembolism.
The Bemiparin Assessment group.
AB - A randomised, prospective, double-blind trial was performed, to compare the
safety and efficacy of a new low-molecular-weight heparin (LMWH) Bemiparin and
standard unfractionated heparin (UFH), for the prophylaxis of postoperative
venous thromboembolism. 300 patients scheduled to undergo elective hip
arthroplasty were included. The principal outcome measures were the incidence of
thromboembolic events and bleeding complications. 149 patients received 3,500
anti-Xa IU of bemiparin plus a placebo injection daily and 149 patients received
5,000 IU of UFH twice a day. The two groups were similar with respect to factors
likely to affect the risk of developing post-operative venous thromboembolism
(VTE) and risk of bleeding events. During the post-operative period, 34 patients
developed VTE complications; 9 (7.2%) in the bemiparin group and 25 (18.7%) in
the UFH group. VTE in the two groups was statistically significant (OR of 2.96;
95% CI 1.32-6.62 and p = 0.01). There were no significant differences in the
frequency of bleeding complications: major bleeding requiring discontinuation of
prophylaxis, (OR 1.21; 95% CI 0.36-4.05; p = 1.00), the measured median operative
blood loss (p = 0.77) or the median postoperative drain loss (p = 0.97), and the
number of patients who developed wound haematoma (OR 0.87; 95% CI 0.31-2.46; p =
1.00). A comparison of coagulation parameters on the preoperative day with post
operative day 2 +/- 1, day 6 +/- 1 and day of discharge showed a significantly
higher AT concentration, anti-factor Xa activity and TFPI levels in the bemiparin
group when compared with UFH. This study demonstrates that bemiparin, in a single
daily subcutaneous dose of 3,500 anti-Xa IU in high risk patients undergoing hip
arthroplasty is more effective than UFH administered twice daily at a dose of
5,000 IU in the prevention of postoperative VTE. Both agents are equally safe.
PMID- 10780312
TI - Recurrent venous thrombosis and markers of inflammation.
AB - Inflammatory processes may play a key role in venous thrombosis, by inducing a
procoagulant state through the action of cytokines and chemokines on monocytes
and endothelial cells. Plasma concentrations of three inflammatory mediators,
interleukin 6 (IL-6), interleukin 8 (IL-8) and monocyte chemotactic protein 1
(MCP-1), that mediate the cross-talk between inflammation and coagulation, were
measured in 182 subjects with recurrent venous thrombosis and 350 healthy
subjects recruited through a general practice. Elevated levels of IL-6 (>90th
percentile of the control group) were detected in 25.8% of the patients with
venous thrombosis in comparison with 10% (by definition) of the controls [odds
ratio 2.4 (95%CI 1.5-3.8)]. In 21.5% of the patients elevated plasma levels of IL
8 (>90th percentile) were determined [odds ratio 2.0 (95%CI 1.2-3.5)]. Elevated
levels of MCP-1 (>90th percentile) were detected in 24.1% of the patients [odds
ratio 1.9 (95%CI 1.2-3.2)]. This is the first large clinical study showing that
an increase in inflammatory mediators is associated with venous thrombosis.
Future prospective studies are necessary to clarify the causal nature of the
inflammatory process with respect to venous thrombosis.
PMID- 10780311
TI - Thrombotic variables and risk of idiopathic venous thromboembolism in women aged
45-64 years. Relationships to hormone replacement therapy.
AB - Hormone replacement therapy (HRT) has been shown to increase the relative risk of
idiopathic venous thromboembolism (VTE) about threefold in several observational
studies and one randomised controlled trial. Whether or not this relative risk is
higher in women with underlying thrombophilia phenotypes, such as activated
protein C (APC) resistance, is unknown. We therefore restudied the participants
in a case-control study of the relationship between the use of HRT and the
occurrence of idiopathic VTE in women aged 45-64 years. After protocol
exclusions, 66 of the cases in the original study and 163 of the controls were
studied. Twenty haematological variables relevant to risk of VTE were analysed,
including thrombotic states defined from the literature. The relative risk of VTE
showed significant associations with APC resistance (OR 4.06; 95% CI 1.62,
10.21); low antithrombin (3.33; 1.15, 9.65) or protein C (2.93; 1.06, 8.14); and
high coagulation factor IX (2.34; 1.26, 4.35), or fibrin D-dimer (3.84; 1.99,
7.42). HRT use increased the risk of VTE in women without any of these thrombotic
states (OR 4.09; 95% CI 1.26, 13.30). A similar effect of HRT use on the relative
risk of VTE was also found in women with prothrombotic states. Thus for example,
the combination of HRT use and APC resistance increased the risk of VTE about 13
fold compared with women of similar age without either APC resistance or HRT use
(OR 13.27; 95% CI 4.30, 40.97). We conclude that the combination of HRT use and
thrombophilias (especially if multiple) increases the relative risk of VTE
substantially; hence women known to have thrombophilias (especially if multiple)
should be counselled about this increased risk prior to prescription of HRT.
However, HRT increases the risk of VTE about fourfold even in women without any
thrombotic abnormalities: possible causes are discussed.
PMID- 10780313
TI - Use of the PFA-100 apparatus to assess platelet function in patients undergoing
PTCA during and after infusion of c7E3 Fab in the presence of other antiplatelet
agents.
AB - The PFA-100 (Dade) is a new functional whole blood analyzer, the accuracy and
reliability of which have been evaluated in von Willebrand disease and during
acetyl salicylate acid therapy. This new test has the advantages of rapidity and
simplicity. It may be useful to monitor new antiplatelet agents, such as
GPIIb/IIIa receptor antagonists. The objective of this study was to assess the
PFA-100 in comparison with aggregometry and with the percentage of blockaded
receptors GPIIb/IIIa during and after c7E3 Fab infusion in fifteen patients
undergoing PTCA. Our results showed a change of closure time values from normal
to abnormal within a small margin of flow cytometric values (60-75% of blockaded
receptors), and moreover a variable platelet response to long-term low dose
aspirin treatment in agreement with aggregometry. No influence with heparin was
observed. In conclusion, this study shows that PFA-100 may be helpful in the
decision making for additional antiaggregant therapy before PTCA or in monitoring
long-term GPIIb/IIIa receptor antagonist treatment.
PMID- 10780314
TI - Regional variation in plasminogen activator inhibitor-1 expression in adipose
tissue from obese individuals.
AB - High plasma plasminogen activator inhibitor-1 (PAI-1) activity is a frequent
finding in obesity and adipose tissue has recently been suggested to be a source
of circulating PAI-1 in humans. In the present study, differences in adipose
tissue gene expression and protein secretion rate of PAI-1 between subcutaneous
and visceral adipose tissue was analysed in specimens obtained from 22 obese
individuals. The secretion rate of PAI-1 was two-fold higher in subcutaneous
adipose tissue than in visceral adipose tissue (292 +/- 50 vs 138 +/- 24 ng PAI
1/10(7) cells, P <0.05). In accordance with the secretion data, subcutaneous
adipose tissue contained about three-fold higher levels of PAI-1 mRNA than
visceral adipose tissue (2.43 +/- 0.37 vs 0.81 +/- 0.12 attomole PAI-1
mRNA/microg total RNA, P <0.00 ). PAI-1 secretion from subcutaneous but not from
visceral adipose tissue correlated significantly with cell size (r = 0.43,
P<0.05). In summary, subcutaneous adipose tissue secreted greater amounts of PAI
1 and had a higher PAI-1 gene expression than visceral adipose tissue from the
same obese individuals. Bearing in mind that subcutaneous adipose tissue is the
largest fat depot these finding may be important for the coagulation
abnormalities associated with obesity.
PMID- 10780315
TI - Effects of fluvastatin and bezafibrate combination on plasma fibrinogen, t
plasminogen activator inhibitor and C reactive protein levels in coronary artery
disease patients with mixed hyperlipidaemia (FACT study). Fluvastatin Alone and
in Combination Treatment.
AB - AIM OF THE STUDY: We studied the effects of fluvastatin and bezafibrate in
monotherapy and in combination on plasma fibrinogen, t-plasminogen activator
inhibitor (PAI-1) and C reactive protein (CRP) in patients with coronary artery
disease (CAD) and mixed hyperlipidaemia. DESIGN: In this randomised, double
blind, multicentre trial 333 patients with stable angina pectoris or previous
myocardial infarction or coronary revascularisation and mixed hyperlipidaemia
(LDL-cholesterol 135-250 mg/dl and triglycerides (TG) 180-400 mg/dl) were
randomised to fluvastatin 40 mg, bezafibrate 400 mg, fluvastatin 20 mg +
bezafibrate 400 mg or fluvastatin 40 mg + bezafibrate 400 mg treatments for 24
weeks. RESULTS: Plasma fibrinogen significantly decreased after treatment with
the combinations fluvastatin+bezafibrate (-14 and -16%) and with bezafibrate
monotherapy (-9%). No significant reduction was observed after fluvastatin
monotherapy (-4%). No significant changes were observed in PAI-1 and CRP plasma
levels. Combination therapy significantly decreased both LDL-C and TG, and
significantly increased HDL-C. CONCLUSIONS: The combined effects on fibrinogen
and plasma lipids achieved by fluvastatin and bezafibrate combination treatment
might be more useful than the simple reduction of cholesterol in preventing
ischaemic cardiovascular disease.
PMID- 10780316
TI - Intermediate and severe hyperhomocysteinemia with thrombosis: a study of genetic
determinants.
AB - Hyperhomocysteinemia is an independent risk factor for cardiovascular disease. In
search of genetic factors causing elevated levels of total homocysteine in plasma
(tHcy), we investigated a cohort of consecutively identified, unrelated
thrombosis patients (n = 28) having intermediate or severe hyperhomocysteinemia
(30 micromol/l 100 micromol/l,
respectively). The methylene-tetrahydrofolate reductase (MTHFR) 677C-->T
genotype, and the complete cystathionine beta-synthase (CBS) genotype was
determined in all patients. We found that the MTHFR T/T genotype was strongly
correlated with intermediate hyperhomocysteinemia, being present in 73.9% of
those cases (17 of 23). In three of five patients with severe
hyperhomocysteinemia, compound heterozygosity for CBS mutations was detected.
Among the mutations, two novel missense mutations: 1265C-->T (S422L) and 1397C-
>T (S466L) were detected. The phenotype in those patients was quite mild,
thromboembolism apart. This indicates that a search for CBS mutations in patients
with severe hyperhomocysteinemia is important to ensure the detection of a
possible CBS deficiency, thus enabling treatment. Co-existence of the MTHFR T/T
genotype and the common CBS 844ins68 variant was significantly higher among
patients (10.7%) as compared to controls (1.2%), indicating that this genotype
combination is a thrombotic risk factor (P <0.05). In a few patients,
hyperhomocysteinemia could not be explained by this genetic approach, suggesting
that other genetic risk factors were implicated.
PMID- 10780317
TI - HPA-1 and HPA-3 polymorphisms of the platelet fibrinogen receptor and coronary
artery disease and myocardial infarction.
AB - Platelet fibrinogen receptor (glycoprotein [GP] IIb/IIIa) plays a fundamental
role in atherothrombosis. The human platelet antigen (HPA) -1 and the HPA-3 are
the most extensively studied polymorphisms of GPIIIa and GPIIb, respectively.
This study was designed to test, in a large population, the hypothesis that these
polymorphisms represent a risk factor for the occurrence of coronary artery
disease (CAD) and myocardial infarction (MI). Consecutive, angiographically
examined patients with significant coronary stenoses but without symptoms or
signs of old or acute MI constituted the group with CAD (CAD, n = 998) and those
with old or acute MI constituted the group with MI (MI, n = 793). As controls
served subjects, matched with patients for age and sex, with neither angiographic
CAD nor symptoms or signs of MI (matched controls [MC], n = 340) as well as a
group of blood donors without cardiac symptoms or signs of CAD (BD, n = 104).
Genotype distribution was similar across the groups; HPA-1a/a: HPA-1a/b: HPA-1b/b
was 75.0%: 22.1%: 2.9% in BD, 72.6%: 24.7%: 2.6% in MC, 70.5%: 26.8%: 2.7% in
CAD, and 70.7%: 26.4%: 2.9% in MI; HPA-3a/a: HPA-3a/b: HPA-3b/b was 39.4%: 40.4%:
20.2% in BD, 33.5%: 50.0%: 16.5% in MC, 35.0%: 46.4%: 17.0% in CAD, and 37.1%:
48.0%: 16.5% in MI. There was no interaction between these polymorphisms, nor
between each of these polymorphisms and other risk factors. Thus, the HPA-1 and
HPA-3 polymorphisms are neither separately nor in concert associated with any
measurable increase of the risk for CAD or MI in angiographically evaluated
subjects.
PMID- 10780318
TI - The role of vitamin B12 in fasting hyperhomocysteinemia and its interaction with
the homozygous C677T mutation of the methylenetetrahydrofolate reductase (MTHFR)
gene. A case-control study of patients with early-onset thrombotic events.
AB - Total fasting plasma homocysteine (tHcy), homozygosity for the C677T mutation of
the methylenetetrahydrofolate reductase (MTHFR) gene and for the A2756G mutation
of the methionine synthase (MS) gene, vitamin B12 and folate plasma levels were
evaluated in 170 consecutive patients (89 M, 81 F; mean age 41 +/- 12 yrs) with
documented early-onset thrombosis (89 venous, 69 arterial, 12 both; mean age at
first episode 36 +/- 11 yrs), and in 182 age- and sex-matched healthy control
subjects. Moderate hyperhomocysteinemia (HHcy, tHcy >19.5 microM in men and >15
microM in women) was detected in 45 patients (26.5%) and in 18 controls (9.9%,
Mantel-Haenszel OR and 95% C.I. after stratification for arterial or venous
thrombosis: 3.25, 1.78-5.91). The 677TT MTHFR genotype was not significantly more
prevalent in patients (27.6%) than in controls (21.4%, RR = 1.42: 0.84-2.41), and
markedly contributed to HHcy (Mantel-Haenszel RR after stratification for
case/control status: 8.29, 4.61-14.9). The 2756GG MS genotype, observed in 4
patients (2.4%) and 8 controls (4.4%), was not associated to HHcy. tHcy was
negatively correlated to folate and vitamin B12 levels, with better correlation
found in subjects with the 677TT mutation (r = -0.42 and -0.25) than with the
677CC or CT MTHFR genotype (r = 0).37 and -0.11). However, folate was similar in
patients and controls and vitamin B12 was higher in patients (460 +/- 206 vs. 408
+/-185 pg/ml, p = 0.011). In a generalized linear model, 44% of the variation in
tHcy levels was explained by folate and vitamin B12 levels, the MTHFR genotype,
gender, and by the interaction of the MTHFR genotype with folate (p < or =0.028);
the interactions of vitamin B12 with the MTHFR genotype, gender and
patient/control status also significantly contributed to the variation in tHcy
levels (p < or =0.028). A 4-week administration of 5-methyltetrahydrofolate (15
mg/day) markedly lowered plasma tHcy in 24 patients with MTHFR 677TT genotype,
but the response to treatment correlated with vitamin B,2 levels (p = 0.023).
Subjects carrying the MTHFR 677TT genotype have higher folate and vitamin B12
requirements irrespective of the A2756G polymorphism of the MS gene. Yet
unidentified abnormalities of MS or of any of the enzymes participating in the
synthesis of methylated vitamin B12 may play an important role in the phenotypic
expression of moderate hyperhomocysteinemia.
PMID- 10780319
TI - Exclusion of known protease-activated receptors in factor VIIa-induced signal
transduction.
AB - The protease activity is mandatory for intracellular activities induced by
coagulation factor VIIa (FVIIa), and in this way it resembles signal transduction
induced by thrombin and trypsin caused by specific, proteolytic cleavage of
protease activated receptors (PARs). The mechanism for FVIIa-induced signal
transduction is, however, not known although a mechanism involving PAR cleavage
has been deduced from studies of cytosolic Ca2+ release and p44/p42 mitogen
activated protein kinase (MAPK) activation. In the present work we have examined
the possibilities that i) FVIIa-induced signal transduction involves the
activation of one of the four known PARs, or ii) exposure of cells to FVIIa
releases a soluble ligand that is responsible for MAPK activation. For this
purpose, we evaluated the effects of FVIIa, thrombin, FXa, trypsin and PAR
agonist peptides on the Ca2+ release and MAPK activation in tissue factor-(TF)
transfected baby hamster kidney (BHK[+TF]) cells and Madin-Darby canine kidney
(MDCK) cells. FVIIa induced a significant MAPK signal in BHK(+TF) cells and in
MDCK-I and -II cells whereas no MAPK activation was observed with thrombin, FXa
or PAR agonist peptides. Thrombin, trypsin, PAR-1 and PAR-2 agonist peptides
induced a prominent Ca2+ response in both cell types. In contrast the cells did
not respond with a detectable Ca2+ signal when treated with FVIIa. These results
suggest that the intracellular activity induced by FVIIa is distinctly different
from that induced by trypsin, thrombin and FXa not involving any of the known
PARs. Conditioned medium from BHK(+TF) cells treated with FVIIa failed to induce
a MAPK response in untreated BHK(+TF) cells when FVIIa was removed by
immunoadsorption from the medium prior to its transfer to the untreated BHK(+TF)
cells. Although it is not possible entirely to exclude a transient response close
to the cell surface, the data suggest that the intracellular response was not
induced by an autocrine release of a soluble mediator to the medium.
PMID- 10780320
TI - The HR2 haplotype of factor V: effects on factor V levels, normalized activated
protein C sensitivity ratios and the risk of venous thrombosis.
AB - We studied the HR2 haplotype of the factor V gene in a case-control study for
venous thrombosis including 474 patients with a first deep-vein thrombosis and
474 age- and sex-matched healthy controls (Leiden Thrombophilia Study, LETS). We
investigated both the original His1299Arg (A4070G) polymorphism and the Met385Thr
(T1328C) polymorphism. This latter polymorphism, located in exon 8 (heavy chain),
is always present in the HR2 haplotype, but also occurs on its own in a His1299
(wt) background. The HR2 haplotype was not associated with an increased risk of
venous thrombosis (OR = 1.2, 95% confidence interval: 0.8-2.0). We did not find
an association between the HR2 haplotype and a reduced sensitivity for activated
protein C (APC) in non-carriers of factor V Leiden (FVL). However, in compound
heterozygous FVL/HR2 carriers the sensitivity for APC was reduced. The HR2
haplotype was also associated with reduced factor V antigen levels in both
patients and controls. Sequence analysis of the promoter region of factor V in
HR2 homozygotes did not reveal any sequence variations that could explain the
reduced FV levels. Our results show that the HR2 haplotype is not associated with
an increased risk of venous thrombosis or with a reduced sensitivity for APC in
non-FVL carriers. However, the HR2 haplotype is associated with a reduced
sensitivity for APC in carriers of FVL and with reduced factor V antigen levels.
PMID- 10780322
TI - The thrombogram: monitoring thrombin generation in platelet-rich plasma.
AB - A method is described in which thrombin activity in clotting plasma can be
monitored through the continuous measurement of the fluorescent split-product of
the substrate Z-Gly-Gly-Arg-AMC. The signal is not impaired by turbidity;
therefore proper measurement is not disturbed by the occurrence of a clot or the
presence of platelets and direct measurement in platelet rich plasma is possible.
PMID- 10780321
TI - Analysis of prothrombotic effects of two human monoclonal IgG antiphospholipid
antibodies of apparently similar specificity.
AB - Two human monoclonal antiphospholipid antibodies (APA) of the IgG type, HL-5B and
RR-7F have been generated from a patient with primary antiphospholipid syndrome
and recurrent cerebral microemboli (H.L.) and from a patient with SLE without
evidence of recurrent thrombosis (R.R.). Both monoclonal APA have similar
characteristics in ELISA tests. To further analyse the prothrombotic potential,
their effect on human monocytes and platelets, and bovine aortic endothelial
cells (BAEC) was investigated. Monocytes were isolated from buffy coats by
standard techniques. They were incubated either with the respective monoclonal
APA in different concentrations, or a control monoclonal IgG of the same subtype,
or plasma of the patients, from whom the antibodies were isolated. Incubation
with LPS served as positive control. BAEC were grown to confluence, and then
incubated with the appropriate agonists. Procoagulant activity (PCA) was
determined by a single stage clotting assay. PCA expression after incubation is
given as the ratio of the coagulation times observed with media only divided by
that observed with the agonist. A PCA ratio >1 indicates the induction of PCA by
the agonist. At 1 microg/ml HL-5B yielded a PCA ratio of 1.63 +/- 0.16 while RR
7F induced no significant rise to 1.06 +/- 0.18. Dose response curves showed that
RR-7F can induce PCA at higher concentrations. However, its effect is approx.
1/50 of HL-5B based on equimolar antibody concentration. Further analysis
indicates that the majority of the PCA induced by monoclonal APA can be inhibited
by a specific tissue factor antibody. Neither monoclonal antibody induced PCA in
BAEC. Sera from both patients were able to induce PCA in monocytes. However, the
PCA ratio of serum from H.L. was higher (1.78) than that of R.R. (1.44). Neither
monoclonal APA had an effect on platelets as determined by flow cytometric
analysis of CD62P, CD41, CD42b expression and fibrinogen binding with and without
previous activation with 5 microM ADP or 15 microM TRAP-6. Similarly, there were
no differences in platelet aggregation to different stimuli including submaximal
activation. In summary, these data provide further evidence that induction of
tissue factor in monocytes is one of the procoagulant effects of APA.
Furthermore, the binding specificity of APA is perhaps not suited to predict the
biological effects of the antibodies.
PMID- 10780323
TI - A functional assay suggests that heterodimers exist in two C-terminal gamma-chain
dysfibrinogens: Matsumoto I and Vlissingen/Frankfurt IV.
AB - Because it contains three pairs of polypeptides, fibrinogen isolated from
heterozygous individuals is expected to be a mixture of homodimers and
heterodimers. Nevertheless, heterozygous individuals with only homodimers have
been identified. We synthesized two recombinant fibrinogens with the mutations
from fibrinogen Vlissingen/ Frankfurt IV (gamma(delta)319, 320) and Matsumoto I
(gammaD364H), both identified in heterozygous individuals. We found that
polymerization of these fibrinogens was undetectable in 30 min; polymerization of
a 1:1 mixture of variant and normal fibrinogen was the same as polymerization of
a 1:1 mixture of buffer and normal fibrinogen; polymerization of either plasma
fibrinogen was markedly impaired when compared to the 1:1 mixture of the
respective variant and normal fibrinogens. We conclude that each plasma
fibrinogen is a mix of homodimers and heterodimers, such that the incorporation
of heterodimers into the fibrin clot impairs polymerization. We suggest that
incorporation of heterodimers can induce clinical symptoms.
PMID- 10780324
TI - TNF 41-62 and TNF 78-96 have distinct effects on LPS-induced tissue factor
activity and the production of cytokines in human blood cells.
AB - Biological activities of peptides representing two different regions in the TNF
molecule were investigated. We have earlier reported that one of the peptides
studied, TNF 36-62, induced chemotaxis in granulocytes and monocytes. TNF 41-62,
a shorter analog of TNF 36-62, possessed similar chemotactic effects. Both
peptides caused a weak enhancement of LPS -induced IL-6 production and tissue
factor activity by monocytes in whole blood. The third peptide studied, TNF 78
96, was selected from a region located on the opposite side of the beta-sheet
sandwich structure of the TNF molecule, and includes the loop 84-88 that has been
shown to be involved in TNF receptor interaction. TNF 78-96 possessed properties
quite different from TNF 36-62 and TNF 41-62. It amplified several fold PMA
induced secretion of elastase, and enhanced significantly PMA-induced secretion
of cathepsin G from the neutrophils, activities which were effectively abolished
by an anti-human TNF antibody. The TNF 78-96 peptide also inhibited LPS-induced
TF activity in monocytes of whole blood, and it abolished the TNF enhancing
effect of LPS-induced TF activity in a dose dependent manner. This suggests that
the TNF 78-96 peptide may bind to the TNF receptor(s), without potentiating the
same signals as native TNF. It may thereby prevent binding of the native TNF and
the resultant activation effect of TNF. It also, at high concentrations,
inhibited LPS-induced IL-6 production whereas it caused a doubling of LPS-induced
IL-8 in monocytes and granulocytes in whole blood. These results clearly show
that distinct TNF activities can be induced by peptide sequences taken from
different regions of TNF. The TNF 78-96 peptide might be useful in downregulation
of LPS-induced monocyte activations in vivo.
PMID- 10780325
TI - Lack of tPA significantly affects antithrombotic therapy by a GPIIb/IIIa
antagonist, but not by a thrombin inhibitor in mice.
AB - The interaction of fibrinolytic components with platelets or coagulation factors
after endothelial injury, was investigated in mouse deficient in tissue type
plasminogen activator (tPA -/-), or urokinase (uPA -/-) and in their wild type
control (tPA +/+, uPA +/+). A thrombus was induced in the murine carotid artery
using the photochemical reaction. Blood flow was continuously monitored and the
time needed before the vessel became completely obstructed was within 11 min in
all types of mice. When GR144053, a platelet glycoprotein IIb/IIIa antagonist, or
argatroban, a thrombin inhibitor, was applied, the time required to occlusion was
prolonged in a dose-dependent manner in all types of mice. However, when GR144053
was injected in tPA -/- mice, the most significant changes were observed: that is
the estimated ED50 was 14.8 times higher than the one in tPA +/+ mice. On the
other hand, when argatroban was injected in tPA -/- mice, the estimated ED50 was
not changed. Platelet aggregation, haemostasis tests and bleeding times were not
significantly different among the different types of mice. In conclusion, the
antithrombotic effect of platelet inhibition by a GPIIb/IIIa antagonist, is
severely affected by the absence or presence of tPA-production. Thus, the lack of
tPA significantly reduces the antithrombotic efficacy.
PMID- 10780327
TI - Identification of a novel 33-kDa Ser/Thr kinase that phosphorylates the
cytoplasmic tail of protease-activated receptor 1 (thrombin receptor) in human
platelets.
AB - Stimulation of human platelets with thrombin or thrombin receptor agonist peptide
(TRAP/ Ser-Phe-Leu-Leu-Arg-Asn) resulted in phosphorylation of the protease
activated receptor 1 (PAR1). However, protein kinase(s), capable of
phosphorylating PAR1 upon activation of this receptor, has not been as yet
identified in human platelets. The present study was undertaken to assess the
presence of protein kinase(s) that may interact with PAR1 using a procedure based
on the ability of protein kinase to undergo renaturation and phosphorylate a
protein substrate fixed in a gel. We employed a fusion protein that was prepared
using a glutathione S-transferase (GST) and the cytoplasmic tail of PARI (Pro368
Thr425)(GST-PAR1) or a reverse sequenced peptide of this domain (GST-rPAR1). The
results showed that treatment of platelets with thrombin induced about 10-fold
increase in the activity of the 33-kDa Ser/Thr protein kinase, which was also
activated by TRAP, but not by hirudin-treated thrombin or
diisopropylfluorophosphate-inactivated thrombin, suggesting that it is activated
through PAR1. Furthermore, treatment of platelets with thromboxane A1 analog,
STA2, led to an activation of this protein kinase and phosphorylation of PAR1. In
conclusion, the present study provides evidence of homologous and heterologous
activation of a novel 33-kDa Ser/Thr kinase that phosphorylates the cytoplasmic
tail of PAR1.
PMID- 10780326
TI - Thrombopoietin increases platelet sensitivity to alpha-thrombin via activation of
the ERK2-cPLA2 pathway.
AB - Thrombopoietin (TPO) regulates stem cell proliferation and maturation of
megakaryocytes by activating the c-Mp1-receptor, a member of the hematopoietic
cytokine family. As human platelets possess c-Mp1-receptors and
supraphysiological concentrations of TPO trigger platelet aggregation and
secretion, we searched for the signalling pathways through which the c-Mp1
receptor might activate platelets. A physiological concentration of TPO (20
ng/mL) did not trigger platelet functions, but increased their sensitivity to
alpha-thrombin resulting in a 4-fold faster dense granule secretion. The effect
of TPO was abolished by indomethacin and caused by synergism with signal
generation by alpha-thrombin at the level of the cytosolic phospholipase A2
(cPLA2) pathway resulting in more arachidonate release, cPLA2 phosphorylation and
thromboxane A2 formation. A similar synergism was seen at the level of
extracellular signal-regulated kinase 2 (ERK2 or p42-MAPK). These data suggest,
that TPO increases the sensitivity of platelets to alpha-thrombin by enhancing
cPLA2 activation via the ERK2-cPLA2 pathway.
PMID- 10780328
TI - Intimal tissue factor activity is released from the arterial wall after injury.
AB - Tissue factor (TF), the initiator of coagulation, has been implicated as a
critical mediator of arterial thrombosis. Previous studies have demonstrated that
TF is rapidly induced in the normal rodent arterial wall by balloon injury, but
is not associated with fibrin deposition. A second injury, however, performed 10
14 days after the first, is followed by small platelet-fibrin microthrombi. This
study was undertaken to better localize active TF in balloon-injured rat arteries
and to explore possible mechanisms underlying the apparent discrepancy between
injury-induced TF expression and the lack of large platelet-fibrin thrombi. By
immunohistochemistry, TF antigen was first detected in the media 24 h after
injury to rat aortas, and subsequently accumulated in the neointima. Using an ex
vivo flow chamber, no TF activity (Factor Xa generation) was found on the luminal
surface of normal or injured aortas. Wiping the luminal surface with a cotton
swab exposed TF activity in all vessels; levels were increased approximately 3
fold in arteries containing a neointima. The exposed TF activity was rapidly
washed into the perfusate, rendering the luminal surface inactive. The loss of
luminal TF into the circulation may attenuate thrombosis at sites of arterial
injury.
PMID- 10780329
TI - No evidence for the CD31 C/G gene polymorphism as an independent risk factor of
coronary heart disease.
PMID- 10780330
TI - ABO blood group and risk of venous thrombosis in heterozygous carriers of factor
V Leiden.
PMID- 10780331
TI - Circulating endothelial cells in Behcet's disease with cerebral thrombophlebitis.
PMID- 10780332
TI - Does peroral administration of factor VIII induce oral tolerance in patients with
acquired haemophilia A?
PMID- 10780333
TI - Continuous infusion of recombinant factor VIIa (NovoSeven) in the treatment of a
patient with type III von Willebrand's disease and alloantibodies against von
Willebrand factor.
PMID- 10780334
TI - Recombinant factor VIIa for bleeding in refractory thrombocytopenia.
PMID- 10780335
TI - Factor VIII inhibitor associated with esophageal carcinoma.
PMID- 10780336
TI - Lipoprotein profiles, not anthropometric measures, correlate with serum
lipoprotein(a) values in children: the Taipei children heart study.
AB - OBJECTIVE: Plasma lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular
disease. The purpose of this study is to evaluate the correlation of
anthropometric measures, lipids and lipoprotein profiles and serum Lp(a) values
among children in Taiwan. We will attempt to find parameters that will be able to
predict Lp(a) levels in children. DESIGN AND METHODS: After a probability
proportional-to size, multi-stages sampling procedure, we randomly sampled 1500
schoolchildren from 10 schools in Taipei city. Anthropometric measures including
body weight, body height, waist and hip circumference and skinfolds were
measured. We used standard methods to measure serum total cholesterol (CHOL),
triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), apolipoprotein
A1 and B (ApoA1 and ApoB) and Lp(a) levels. We also calculated low density
lipoprotein-cholesterol (LDL-C) and CHOL HDL-C ratio (TCHR) by formula. RESULTS:
We sampled 1283 children (635 boys and 648 girls) with a mean age of 13.3 years
(from 12 to 16 years) in this study. The mean and medium serum Lp(a) levels were
16.8 and 8.8 mg/dl among boys and 20.8 and 11.9 mg/dl among girls. Children in
the highest quintile of Lp(a) (mean = 49.6 and 58.6 mg/dl for boys and girls,
respectively) had higher CHOL, LDL-C, ApoB levels and TCHR than children in the
lowest quintile (mean = 3.1 and 3.7 mg/dl for boys and girls, respectively).
Lipids and lipoprotein profiles, such as CHOL, LDL-C, Apo-B and TCHR were
positively correlated with Lp(a) levels in both genders. Furthermore, the
children with Lp(a) levels greater than or equal to 30 mg/dl had higher CHOL, LDL
C and Apo-B levels when compared to children with Lp(a) levels less than 30
mg/dl. After adjusting for age, cigarette smoking, alcohol drinking, puberty
development and heart rates, LDL-C and ApoB levels were significantly positively
associated with Lp(a) levels while ApoA1 was negatively associated among boys.
Among girls, only Apo-B was significantly positively associated with Lp(a) and TG
was negatively associated with Lp(a) levels. Most importantly, none of the
anthropometric measures were significantly correlated with Lp(a) levels.
CONCLUSIONS: From this study, we found that lipids and lipoproteins profiles,
rather than degree of adiposity as reflected by anthropometric measures, are
significantly associated with serum Lp(a) levels among school children.
PMID- 10780337
TI - Relationship between hyperuricemia and other cardiovascular disease risk factors
among adult males in Taiwan.
AB - Hyperuricemia is associated with cardiovascular disease risk factors such as
obesity, impaired glucose tolerance, hypertension, and hyperlipidemia. However,
this relationship between serum uric acid (SUA) concentrations and cardiovascular
disease (CVD) is a controversial one, especially among males. The purpose of this
study is to evaluate the association between SUA concentrations and other CVD
risk factors among adult males in Taiwan. After multi-stage sampling procedures,
we randomly selected 1743 Taiwanese males with a mean age of 35 years (from 22 to
54) in this study. Anthropometric, blood pressure and biochemical variables,
including serum uric acid, glucose, total cholesterol and triglyceride
concentrations, were measured. Among the study population, the mean SUA
concentration was 6.5 +/-1.5 mg/dl. There were 290 (16.6%) subjects with SUA
concentrations > or = 8.0 mg/dl (defined as hyperuricemia). Compared to
normouricemic subjects, hyperuricemic subjects had significantly greater age
adjusted body weight (75.3 vs. 69.2 kg, p < 0.001), body mass index (BMI, 25.5
vs. 23.6 kg/m2, p < 0.001), higher blood pressure (BP, 120.2 vs. 115.2 mmHg for
systolic BP and 78.5 vs. 75.3 mmHg for diastolic BP, both p < 0.001) and blood
lipid concentrations (193.8 vs. 182.1 mg/dl for total cholesterol and 123.7 vs.
94.4 mg/dl for triglycerides, both p < 0.001). SUA concentration was positively
correlated with body weight, BMI, BP and serum lipid concentrations (all p <
0.001). In multivariate regression analyses, after adjusting for potential
confounders, SUA concentration was significantly positively associated with
diastolic BP, serum total cholesterol and triglyceride concentrations. An
increase of 1 mg/dl of SUA was associated with a 2.1 mg/dl elevation in serum
total cholesterol (p < 0.001) and a 5.4 mg/dl increase in triglyceride (p <
0.001). From this study, we found that hyperuricemia in subjects is associated
with being overweight, and having high blood pressure and hyperlipidemia. There
is a significantly positive association between SUA concentration and other CVD
risk factors among adult males in Taiwan.
PMID- 10780338
TI - Sociodemographic factors related to self-medication in Spain.
AB - To identify the sociodemographic factors associated to self-medication (i.e. use
of non-prescription medicines) and undesirable self-medication, a cross-sectional
study was carried out using a sample (n = 20,311) representative of the
population of adults of 16 years of age and older in Spain. Multivariate Cox's
regression was used. The prevalence of self-medication in the sample was 12.7%
during the two weeks preceding the interview. Self-medication is more prevalent
among women, persons who live alone, and persons who live in large cities. For
persons who reported acute disorders, self-medication prevalence was higher among
those with higher educational levels. The prevalence of undesirable self
medication in the sample was 2.5% during the two weeks previous to the interview.
Undesirable self-medication is twice as common among persons older than 40 years,
as compared to persons younger than 27 years. Undesirable self-medication
prevalence is 53.0% higher among those who live alone as compared to those who
live with their partner (95% confidence interval (CI): 15.2-103.2) and 36.8%
higher among students as compared to full-time workers (95% CI: 1.9-83.5). People
over 40 years of age, people living alone, and students should be the priority
target populations for public health education programs aimed at improving the
quality of self-medication behavior.
PMID- 10780339
TI - Changes in the alcohol consumption pattern among schoolchildren in Barcelona.
AB - Alcohol consumption is a major health problem in most developed countries. In
Mediterranean countries, experimentation with alcoholic beverages typically
occurs during the early adolescent years within the family context. In this study
we analysed alcohol consumption and its determinants in a survey of a sample of
schoolchildren in 1994. The results were compared to those obtained in a previous
study in 1987. In 1994 a random, stratified sample of all 8th grade classrooms of
a city, public, private or subsidised school was, obtained. Some 759 13 and 14
year old pupils responded to a self-administered questionnaire on health-related
habits. Overall, there was a high awareness of alcohol in the environment, as
20.7% of the pupils reported their father was a regular or occasional drinker and
41.6% declared some of their friends were drinking. Compared with the results of
the 1987 survey, there was a marked decline in the proportion of schoolchildren
reporting alcohol consumption by their father or their siblings. Regarding the
pupils' consumption, 66.7% of them had tried drinking alcohol in 1994, 54.7%
declared they were allowed to drink in family celebrations, and 17.2% had
experienced being drunk. Most of these indicators showed a significant decrease
compared with the 1987 data, with the exception of drunken episodes where there
appears to be no changes. The results suggest that there are some changes in the
Spanish context, where regular drinking among adolescents may be declining.
PMID- 10780341
TI - Prevalence of hypothyroidism and diabetes mellitus in elderly kibbutz members.
AB - The aim of this study was to determine the prevalence of hypothyroidism and
diabetes mellitus (DM) in elderly (aged 65-92 years) kibbutz members in Northern
Israel. METHOD: The medical records of 1096 elderly (642 females and 454 males)
residing in 11 kibbutzim were reviewed for data regarding thyroid function tests
(TSH and FT4) and fasting blood glucose. Fasting blood glucose levels above 7.8
mmol/l was considered diagnostic for diabetes mellitus. RESULTS: The prevalence
of hypothyroidism was 14% (9.7% in males and 18.2% in females) and that of DM was
11.5% (12.1% in males and 11.1% in females). In 74% of the diabetics the
diagnosis was made after the age of 60 years. Distribution of treatment
modalities in diabetics was as follows: diet only 42%. oral hypoglycemic agents
52% and Insulin 6%. Subclinical hypothyroidism (serum TSH levels above 4.5 mU/L
with normal FT4 levels) was detected in 38% of all the hypothyroid subjects.
CONCLUSION: The data suggest that diabetes mellitus and primary hypothyroidism
are common disorders in elderly subjects. DM in the elderly can usually be
handled with diet and oral hypoglycemic drugs. Since the clinical features of
hypothyroidism in the elderly are often atypical, we suggest that elderly
subjects should be screened for hypothyroidism.
PMID- 10780340
TI - Associations of family environment and individual factors with tobacco, alcohol,
and illicit drug use in adolescents.
AB - Despite abundant literature the respective roles of psychosomatic status,
personality, health perception, family environment, and sport activity in
tobacco, alcohol and illicit drug use have not been well known. To assess their
roles, an epidemiological cross-sectional study was conducted in 3294 middle and
high school adolescents, 2396 (73%) of whom agreed to participate. The
standardized questionnaire was filled out by the teenagers under the supervision
of the teachers. Strong associations were found between tobacco, alcohol, and
illicit drug use. The prevalence of alcohol use and illicit drug use were
respectively 7 and 10 times higher in smokers than in non-smokers. On the whole,
the potential risk factors for tobacco, alcohol, and illicit drug use were age,
psychosomatic status and psychotropic drug consumption, boring family atmosphere,
not living with both father and mother, and health perception. Mother being a
housewife was a protective factor. No marked role was noted for the head of
family's socio-occupational category. Personality would be indicators of self
control ability. Indeed, some self-reported personalities (serious, attentive,
calm, organized) had protection roles whereas some others (easily irritable,
aggressive, worried, clumsy, careless, solitary, etc.) were risk factors (risk
taking or deviant behaviors). Some sports activities were found to be negatively
related, but some others related positively with drug use, possibly due to
repetitive meetings between the adolescents at risk. Preventive measures may be
targeted at these risk factors.
PMID- 10780342
TI - Hospitalizations due to falls in Jewish and Arab children in northern Israel.
AB - In Israel, there are no epidemiological data regarding nonfatal childhood falls.
A retrospective survey was conducted in order to find epidemiological
characteristics of childhood falls among the different populations of northern
Israel. During the years 1993 through 1995, 3082 children were hospitalized in
Rambam Medical Center (RMC) due to injury. The children were subdivided into the
four main populations: Jewish and Arab residents of Haifa region (the main
metropolitan area) and Jewish and Arab residents of the Galilee region (the rural
region). All of the children who suffered injury that required mechanical
ventilation and careful assessment were admitted to the PICU. The charts of the
children admitted to the PICU were then further studied. The demographic
characteristics of all the cases of falls were statistically analyzed and the
annual admission rates due to falls were calculated using the national
statistical registrations of children in Israel. Falls were responsible for 1049
admissions due to injury, one third of the total number of children who were
admitted due to an injury. Most of the children were five years of age or
younger. Two thirds of the total childhood falls were of Arabs. The majority of
the admissions were of two major sub-populations of northern Israel: Arab
residents of Galilee region (66%) and Jewish residents of Haifa region (34%).
Higher admission rate was found among Arab children of the Western Galilee
district in comparison with Jewish children of the Haifa district. Most of the
children who were admitted to the PICU were Arabs: nearly all of these children
were from the rural region. More Arab than Jewish children who fell were admitted
to the PICU and the majority of these cases were falls from buildings (private
houses). Arab children of the rural region were responsible for 95% of the cases.
These falls were mainly in staircases (46%) and from balconies (21%), roofs (11%)
and windows (11%). The findings of the present study suggest that young Arab
rural children in northern Israel are at high risk to a severe injury due to
fall. Possible causes are discussed and a preventative intervention is suggested.
PMID- 10780343
TI - Physical abuse--physicians knowledge and reporting attitude in Israel.
AB - The objective of this study was to assess knowledge and attitudes towards
physical child abuse among pediatricians and family physicians in northern
Israel. METHODS: An interview consisting of multiple choice questions and
vignettes were employed. A stratified sample of 107 physicians from hospitals and
community clinics and of different disciplines and educational cultural
backgrounds was surveyed. RESULTS: Child abuse diagnosis was considered
infrequently or not at all by 43% of the participants and a proportion of them
were hesitant in their reporting intentions. A low consistency in the approach to
diagnosis and management was found. Medical discipline, sex and age of the
physician as well as level of knowledge and the family's socioeconomic status
were not significantly related to reporting behaviors. A significant effect of
medical training/cultural background (p = 0.01) and medical discipline (p = 0.04)
on knowledge of child abuse were found. No relationship between knowledge and
reporting behaviour was found. CONCLUSION: The results of this study are a reason
for concern. A more active role of medical schools and health administrations in
abuse-oriented education and training effort is required, particularly in
societies in transition.
PMID- 10780344
TI - Comparison between research data and routinely collected register data for
studying childhood health.
AB - Cohort studies are usually based on detailed information gathered on a limited
number of individuals. Increasing collection of administrative registers offers
an alternative method to gather health data. In the first study health
information from birth until the age of seven years on 8708 children born in the
two most northern provinces of Finland in 1985-86 was gathered through
questionnaires, medical record reviews, medical examinations and some register
data. In the second study, similar information on 8222 children born in the same
provinces in 1987 was gathered using administrative registers. Both data
collection methods gave equal results for mortality, long-term medication. and
cumulative incidence of diabetes and intellectual disabilities. The register data
identified more children with delayed development, but less children with long
term illness (77% of the level identified by the research data), with asthma
(74%), and with epilepsy (40%). The register data was unsuitable for
investigating hearing and vision disorders. The administrative data gave a gender
ratio similar to that of the research data for two of the variables with poor
coverage (asthma and epilepsy), but identified more boys with long-term illness
in general than the research data. Administrative registers are useful for
studying many long-term health problems, e.g. those resulting in hospital care or
social benefits or those registered in vital statistics. Specific cohort studies
with separate data collection is still needed to study for example outpatient
care, self-assessed health, growth and development.
PMID- 10780345
TI - Confidential enquiry into avoidable vehicle accident deaths in the province of
Modena, Italy.
AB - The authors describe the methods and results of a kind of study confidential
enquiries into avoidable deaths very rarely performed in the Mediterranean area.
After assessing some quali/ quantitative evaluation criteria, an independent
expert panel investigated the quality of each step in emergency health care.
Information was collected by clinical and forensic reports (clinical method). Of
102 cases, 4 were avoidable deaths and 18 probably avoidable. These results,
which are comparable with other similar ones found in Italy (autoptic method) and
abroad, have been useful in highlighting some health care errors: in particular,
in on-site care and in emergency department diagnosis and treatment. Other
avoidable factors emerging were the inappropriateness of transporting severe
trauma cases to a small hospital lacking proper equipment and trained staff, and
the importance of staff training in first emergency care of severe trauma on
ambulance. This situation had been highlighted previously and led to
implementation of trauma centres. The methods implemented turned out to be quite
statistically reproducible and have been used in local health care planning,
especially in the rearrangement of ambulance deployment and emergency staff
training.
PMID- 10780346
TI - Gastrointestinal infection due to Anisakis simplex in southern Italy.
AB - The authors present four cases of infection due to Anisakis in an area where
people are prone to infectious diseases transmitted by raw fish, but in which the
presence of this parasite has never been reported. Three of four cases were
discovered accidently during surgical procedures for co-existing abdominal
pathologies. Raw fish was apparently not involved in all patients.
Characteristics of the patients are discussed.
PMID- 10780347
TI - Epidemiological trend of human leptospirosis in Italy between 1994 and 1996.
AB - In the three-year period 1994 1996, 222 reports on human cases of leptospirosis
were received by the Italian Ministry of Health. The average annual number of
reports was 29.2% lower than in the preceding eight years. In all cases but two
the infections were thought to have been acquired in Italy. As in previous years,
the majority of cases was observed in the northern regions of the country
(83.8%), mostly in males (88.9%). Cases occurred in all age groups, but were more
common in the working-age population (15-64 years). There was no common-source
outbreaks. The typical leptospiral seasonal course, with a peak in August, was
observed. During 1994, leptospirosis was the reported cause of death in 19
patients. Mortality was higher among males than females. The overall fatality
rate was 22.6%. During the study period, a total of 126 cases of leptospirosis
were confirmed by the National Centre for Leptospirosis or one of the 12 Regional
Leptospira Laboratories. Of the 103 patients for whom information on place of
residence, contact with animals, occupational and recreational activities was
available, 98 (95.1%) were people who live in rural areas or devote themselves to
occupational or recreational activities at risk. The likely source of infection
and the mode of exposure were known for 55 patients. Forty-five patients (81.8%)
were likely infected by contaminating water (43 cases) or soil (2 cases), ten
(18.2%) by direct contact with animals or animal urine. Both running (51.2%) and
stagnant water (27.9%) have been reported as a source of infection. Rodents were
implicated in 50.0% of the 10 cases involving animals. In comparison with the
preceding eight-year period, the risk of contracting leptospirosis was found to
have increased for recreational activities (from 34.7 to 38.2%) and decreased for
occupational activities (from 45.8 to 32.7%). A large number of infections,
however, was ascribed to accidental events (25.5%). As in the previous period,
besides fever, the involvement of the liver was the most frequent clinical
manifestation (70.8%). Influenza-like symptoms were the only signs of illness in
15.1% of cases. Infections by 9 different serogroups were detected. The most
frequent antibodies were those against serovars icterohaemorrhagiae, poi,
copenhageni and brattislava. The presence of co-agglutinins against serovars
belonging to different serogroups prevented the identification of the presumptive
infecting serogroup in 19.8% of subjects.
PMID- 10780348
TI - Hepatitis C virus, hepatitis B virus and human immunodeficiency virus infection
in pregnant women in North-East Italy: a seroepidemiological study.
AB - BACKGROUND: Pregnant women can be considered a sentinel population, because they
are a relatively unselected population whose prevalence data may be extended to
the general population. METHODS: A seroepidemiological study was carried out in
Padua (North-East Italy) to assess the epidemiological aspects of HCV. HBV and
HIV infection in 2059 pregnant women consecutively seen at the Department of
Obstetrics and Gynaecology during 1996. Out of them, 1804 (87.2%) were indigenous
and 255 (12.8%) immigrants. Sociodemographical and sanitary data were collected
for each woman. RESULTS: The overall prevalence of anti-HCV was 1.9% (42.5% with
detectable HCV-RNA); HBsAg was found in 1.0%: the prevalence of anti-HIV was
0.3%. Findings are substantially consistent with the epidemiological picture of
such infections in the general population of our geographic area. A parenteral
risk factor for HCV infection was found in 19 subjects (47.5%): 18 were
intravenous drug users and 1 a blood transfusion recipient. HBsAg seroprevalence
was higher in immigrants than in autochthonous (3.1% vs. 0.7% respectively, p <
0.01). One of the 6 anti-HIV positive women was intravenous drug user. Logistic
regression analysis was carried out for each viral agent to determine which
characteristics were independently associated with infection: anti-HCV prevalence
resulted independently associated to Italian origin (OR: 3.7), unmarried status
(OR: 2.7), unemployed condition (OR: 6.1) and history of previous abortion (OR:
2.8). HBsAg prevalence was independently associated to unemployed condition (OR:
10.8), whereas HIV positivity was significantly related to the unmarried status
(OR: 18.5). CONCLUSION: Our study pinpoints the need of screening all pregnant
women for HCV and HIV infection, in addition to the HBsAg screening which is
compulsory in Italy.
PMID- 10780350
TI - A new method for the synthesis of N3-alkylated analogs of 5-fluorouracil.
AB - 5-Fluorouracil (5-FU) is converted to the adducts 1a,b then subjected to
Mitsunobu reaction with the secondary alcohols to give the condensates 2a,b.
Hydrogenation of 2a,b with Pd/C affords N3-alkyl-5-fluorouracil 3a,b.
PMID- 10780349
TI - Synthesis of 3'alpha-carbo-substituted 2',3'-dideoxyribonucleosides from
naturally occurring nucleosides.
AB - Naturally occurring ribonucleosides, uridine and adenosine, were converted to
their 3'alpha-CH2CO2Me and 3'alpha-CH2PO(OPh)2 2',3'-dideoxy analogues. The
present reaction sequence starts with oxidative cleavage of the 2',3'-cis-diol
system, and involves radical-mediated reconstruction of furanose ring as the key
step.
PMID- 10780351
TI - Synthesis and biological activity of unusual nucleosides having 3,4
bis(hydroxymethyl) thietane ring as a sugar moiety.
AB - The enantiomerically pure synthesis of 9-[(2'S, 3'S)-bis(hydroxymethyl)thietan-1'
yl]adenine 2,3'-thio analog of oxetanocin A, was achieved via coupling of
silylated 6-chloropurine and sulfoxide 16 under Pummerer reaction conditions.
PMID- 10780352
TI - Reactivity of 2'-deoxyoxanosine, a novel DNA lesion.
AB - 2'-Deoxyoxanosine (dOxo) is a novel DNA lesion produced from 2'-deoxyguanosine by
the reaction with nitrous acid or nitric oxide. We found that dOxo reacted with
glycine under physiological conditions. The product was identified by
spectrometric data as an adduct between the six membered ring of dOxo and an
amino group of glycine. The adduct was more stable than dOxo under physiological
conditions. The incubation of an oligodeoxynucleotide containing dOxo with
glycine gave also rise to the adduct. These results suggest that dOxo formed in
DNA reacts with amino groups of various compounds around DNA in vivo resulting in
the adduct.
PMID- 10780353
TI - New procedure of the Mitsunobu reaction as the key step in peptide nucleic acid
(PNA) monomers synthesis.
AB - PNAs are relatively novel DNA analogues, intensively studied due to their
potential as gene-targeted drugs with antigene and antisense properties. In 1996
we elaborated a new method of synthesis of PNA monomer backbones based on the
Mitsunobu reaction with N-tosyl-protected (Tos) amino acid esters as acidic
components of the reaction. Since the method used for the Tos group removal
requires conditions incompatible with various functional groups, here we modified
the procedure by replacing the tosyl group with o-nitrobenzenesulfonyl (o-NBS)
group. Using the new procedure we obtained protected PNA monomer backbones with
various amino acid side chains. The pseudodipeptide secondary amine groups were
then deprotected by thiolysis, and after standard work-up acylated with thymin-1
ylacetic acid, to give the protected monomers. Since the deprotection of the
secondary amine group occurs under mild conditions, the procedure is of general
applicability and allows various modifications of PNA structure by using diverse
beta-amino alcohols and alpha-amino acid esters.
PMID- 10780354
TI - Synthetic study on carbocyclic analogs of cyclic ADP-ribose, a novel second
messenger: an efficient synthesis of cyclic IDP-carbocyclic-ribose.
AB - An efficient synthesis of cyclic IDP-carbocyclic-ribose, as a stable mimic for
cyclic ADP-ribose, was achieved. 8-Bromo-N1-carbocyclic-ribosylinosine derivative
10, prepared from N1-(2,4-dinitrophenyl)inosine derivative 5 and an optically
active carbocyclic amine 6, was converted to 8-bromo-N1-carbocyclic
ribosylinosine bisphosphate derivative 15. Treatment of 15 with I2 in the
presence of molecular sieves in pyridine gave the desired cyclic product 16
quantitatively, which was deprotected and reductively debrominated to give the
target cyclic IDP-carbocyclic-ribose (3).
PMID- 10780355
TI - Synthesis and structure-activity relationships of novel nikkomycin analogs:
inhibitors of the fungal cell wall biosynthesis enzyme chitin synthase.
AB - A series of novel nikkomycin analogs, which inhibited chitin synthase, the fungal
cell wall biosynthesis enzyme, has been synthesized and evaluated their
inhibitory activities.
PMID- 10780356
TI - Synthesis of nucleotide antibiotics having N-acyl phosphoramidate linkages.
AB - This paper reports the synthesis of nucleotide antibiotics having N-acyl
phosphoramidate linkages. The key reaction, the construction of the N-acyl
phosphoramidate linkage was achieved by the reaction of nucleoside 5'
phosphoramidite derivatives with carboxamide derivatives in the presence of 5
(3,5-dinitrophenyl)-1H-tetrazole as a very effective activator. By use of this
activator, Phosmidosine was synthesized by condensation of an appropriately
protected 8-oxoadenosine 5'-O-phosphoramidite derivative with an N-protected
prolinamide derivative. In the case of Agrocin 84, the two P-N bonds were
constructed progressively. The N-acyl phosphoramidate linkage at the 5'-position
of the ribose moiety was similarly synthesized. After phosphorylation of the
amino group of the adenine moiety, a fully protected Agrocin 84 derivative, which
would be converted to Agrocin 84, was successfully synthesized.
PMID- 10780357
TI - Nucleic acid synthesis for investigations of gene functions.
AB - The chemical syntheses of genes encoding human c-Ha-ras and T4 endonuclease V are
described. These genes have been used for studies of mutagenesis by damaged bases
and recognition of nucleic acids by proteins. The modes of interaction of photo
damaged DNA and cognate antibodies have also been investigated by biochemical and
physicochemical approaches.
PMID- 10780358
TI - Synthesis and anti-HIV activity of unusual nucleoside oxanosine derivatives.
AB - A series of the oxanosine and carbocyclic oxanosine derivatives were synthesized
to evaluate for their anti-HIV activity. Compound 1, 7 and 9 showed weak anti-HIV
activities.
PMID- 10780359
TI - The first synthesis of herbicidin B, a tricyclic-sugar adenine nucleoside
antibiotic, using samarium diiodide-promoted aldol-type C-glycosidation reaction
as a key-step.
AB - A first total synthesis of the nucleoside antibiotic herbicidin B (1) was
achieved in which a novel aldol-type C-glycosidation reaction promoted by
samarium diiodide (SmI2) was used as a key step. Construction of the desired
stereochemistry of the tricyclic-sugar moiety was successfully achieved by
conformational restriction strategy based on repulsion between adjacent bulky
protecting groups on the pyranose ring.
PMID- 10780360
TI - Synthesis of carbocyclic nucleosides bearing a cyclopropane ring.
AB - A carbocyclic cyclopropane fused nucleoside, 9-(c-4
hydroxymethylbicyclo[3.1.0]hex-r-2-yl)-9H-adenine, has been efficiently
synthesized from 2-azabicyclo-[2.2.1]hex-5-en-3-one (ABH) in 6 steps, namely
cyclopropanation, -reductive amide cleavage (RAC) reaction and adenine ring
construction.
PMID- 10780361
TI - Synthesis of S-adenosyl-L-homocysteine hydrolase inhibitors and their biological
activities.
AB - Several nucleosides have been prepared as a possible inhibitor of human S
adenosyl-L-homocysteine (SAH) hydrolase for the development of anti-viral agents.
Recently, SAH hydrolase has been considered as an attractive target for parasite
chemotherapy for malaria. We report synthesis of several nucleosides including
carbocyclic nucleosides and their inhibitory activities against recombinant
malaria and human SAH hydrolases.
PMID- 10780362
TI - Synthesis of novel nucleotide analogues possessing a difluoromethylenephosphonato
group. Evaluation of the inhibitory activity for purine nucleoside phosphorylase.
AB - Novel nucleotide analogues 1-6 were prepared as "multi-substrate" analogue
inhibitors for purine nucleoside phosphorylases (PNPs). The cyclopropane and the
tetrahydrofuran moieties of the alkyl spacer connecting a nucleobase and
difluoromethylene phosphonic acid were found to be effective for good inhibition
of PNPs.
PMID- 10780363
TI - Synthesis and characterization of new chiral peptide nucleic acid (PNA) monomers.
AB - PNAs are DNA analogues in which the nucleic acid's backbone is replaced by a
chiral or achiral pseudopeptide backbone and nucleobases are attached to the
backbone by methylene carbonyl linkers. The easy to modify PNA structure gives
the possibility to obtain monomers, and subsequently oligomers, with improved
properties. We have synthesised several new PNA monomers, starting from a series
of 2'-substituted methyl N-(2-Boc-aminoethyl)glycinates. The pseudodipeptides
were obtained using modified Kosynkina's method, based on the reductive amination
of N-Boc-protected alpha-amino aldehydes [glycinal, isoleucinal, valinal,
tryptophanal, serinal(Bzl), prolinal] with methyl glycinate. The compounds were
then acylated with nucleic acid base derivatives by simplified procedure, and the
purification was limited to the last step of the synthesis. The applied procedure
is useful in synthesis of various chiral PNA monomers.
PMID- 10780364
TI - Synthesis of oxy-peptide nucleic acids with mixed sequences.
AB - Syntheses of N-Fmoc delta-amino acids with an ether linkage in the main chain and
six different nucleobases on the side chain, Fmoc-NH-C*H(CH2-CH2-B)-CH2-O-CH2
COOH (B = N6-benzoyladenine, thymine, uracil, N-benzoylcytosine, guanine, and N2
isobutyrylguanine) are described. The delta-amino acids were prepared through 8
12 step synthesis starting from L-homoserine and could be linked together to form
novel peptide nucleic acids (oxy-PNAs = OPNAs) by solid-phase peptide synthesis.
PMID- 10780365
TI - Synthesis of oligonucleotides containing the oxidatively modified kappaB site:
unique binding affinity to the NFkappaB p50 homodimer.
AB - Synthesis of oligonucleotide 26-mers including single 5-formyl-2'-deoxyuridine
(1) or 5-formyl-2'-O-methyluridine (2) in place of thymidine at the kappaB site
has been accomplished. One of the 26-mers with 1 was critically discriminated by
the NFkappaB p50 homodimer in binding.
PMID- 10780366
TI - Further studies of KMnO4 oxidation of synthetic DNAs containing oxidatively
damaged bases.
AB - Recently we found that KMnO4 oxidation of DNA oligomers containing a 7,8-dihydro
8-oxoguanine (8-oxo-G) residue induces damage to the neighboring base residues;
other modified bases, 7,8-dihydro-8-oxoadenine (8-oxo-A) and 5-hydroxyuracil (5
oh-U), show similar behavior in DNA. The present study indicated that the ability
to induce damage, which could also occur by the oxidation of a 5-oh-C residue,
was low as in the case of 5-oh-U. On the other hand, in order to examine the
pathways and the intermediates for the oxidative degradation of 8-oxo-A, we have
carried out the KMnO4 oxidation using an 8-oxo-2'-deoxyadenosine derivative as a
model and have determined the structures of the three major products.
PMID- 10780367
TI - Chemical synthesis and properties of (6-4) photoproduct and its analogs.
AB - We report the preparation of a deoxyribooligonucleotide containing a new thymine
(6-4) photoproduct analog. The (6-4) photoproduct is one of the major forms of
DNA lesions, and leads to mutation in DNA. An antibody (64M5) that binds the (6
4) photoproduct has been described. To investigate the interaction of the
photoproduct with the 64M5 antibody, we prepared a (6-4) photoproduct analog in
which the two thymines were connected with a formacetal linkage. With UV
irradiation, the thymine dimer with the formacetal linkage reacted to the (6-4)
photoproduct faster than the phosphodiesterified dimer, and the yields of the
analog was higher than those of the natural thymine dimer. The 64M5 antibody
exhibited sufficient binding to a tetranucleotide containing the (6-4)
photoproduct analog with a formacetal linkage, although the association constant
was slightly lower than that for the natural lesion. This (6-4) photoproduct
analog may be useful for investigation of other proteins that recognize the (6-4)
photoproduct.
PMID- 10780368
TI - Reversible photoligation of DNA via 5-vinyldeoxyuridine.
AB - We report a novel non-enzymatic template-directed reversible photoligation of
oligodeoxyribonucleotides (ODNs). In this photoligation system, a modified ODN
containing 5-vinyldeoxyuridine at 5'-end reacts by photoirradiation at 366 nm
with cytosine and thymine at the 3'-end of another ODN in the presence of a
complementary template to yield a ligated ODN quantitatively. The ligated ODN can
be split site-selectively to regenerate the parent ODN by photoirradiation at 302
nm.
PMID- 10780369
TI - Cleavage of parallel-stranded DNA duplex by peplomycin metal complexes.
AB - Peplomycin-mediated degradation of parallel-stranded (ps) duplex was
investigated. It was found that Co- and Fe-peplomycins degraded ps DNA duplex by
4'-hydrogen abstraction at 5'-GPy (pyrimidine) site in a similar manner to that
of antiparallel B-DNA. While the orientation of two strands of ps and B-form DNA
duplexes are reversed, peplomycin metal complex can bind to ps DNA duplex to
cause oxidative DNA damage. These results indicate that peplomycin metal complex
mainly interacts with one strand which is damaged.
PMID- 10780370
TI - Efficient cross-linking to cytidine by functional nucleobases capable of in situ
activation.
AB - We have previously demonstrated that the ODNs with 2-amino-6-(2
phenylsulfoxyethyl)purine nucleoside derivative were capable of efficient
interstrand cross-linking with cytidine selectively. In this new strategy, less
reactive precursor was auto-activated within a duplex to generate 2-amino-6
vinylpurine derivative. However, it turned out that 2-amino-6-(2-phenylsulfinyl)
ethylpurine nucleoside was not applicable as the precursor for the synthesis of
DNA oligomers with G-rich sequences. In this report, 2-amino-6-(2
methylsulfinylethyl)purine nucleoside has been proven to be more suitable as a
precursor for DNA synthesis. In addition, the ODNs incorporating either 2-amino-6
(2-phenylsulfoxy ethyl)purine or 2-amino-6-vinylpurine showed high reactivity
toward the cytidine at the target site but quite less reactivity was observed for
it at non-target site, demonstrating high site-selectivity.
PMID- 10780371
TI - Synthesis and properties of oligonucleotides containing carbocyclic L-nucleoside
analogues with a restricted glycosyl conformation.
AB - To construct nuclease-resistant oligonucleotides, we designed novel carbocyclic L
nucleoside analogues (1-4) whose glycosyl conformation is fixed at chi = 180
degrees by an oxygen-bridge between the base and the cyclopentane ring. We have
already achieved the racemic synthesis of these analogues. In this study, we
succeeded in synthesizing an optically active form of these analogues. The
properties of oligonucleotides containing them will be shown.
PMID- 10780372
TI - Synthesis of oligodeoxyribonucleotides bearing a functional group at 2'-position
by post-synthetic modification.
AB - A novel 2'-thio-2'-deoxyuridine derivative bearing a reactive ester at 2'
position was synthesized and incorporated into oligodeoxyribonucleotides (ODNs)
for the post-synthetic modification of ODNs. This ODNs was reacted with several
amines to give ODNs having a functional group at 2'-position.
PMID- 10780373
TI - X-ray analysis of a DNA dodecamer containing 2'-deoxy-N4-methoxycytidine.
AB - The crystal structure of DNA dodecamer with the sequence of d(CGCAAATTXGCG),
where X is 2'-deoxy-N4-methoxycytidine, has been determined by X-ray analysis.
The dodecamers form a double helix with B-form conformation. The electron density
indicates that the two modified cytosine bases respectively make a pair with the
adenine bases on the opposite strand in a manner of Watson-Crick geometry and
that the methoxy groups are in anti conformation to the N3 atom.
PMID- 10780374
TI - Homogeneous detection of a target nucleic acid sequence by combination of the
intercalation activating fluorescence DNA probe and the isothermal sequence
amplification.
AB - We demonstrated the homogeneous real-time detection of RNA produced during
isothermal TRC amplification by INAF probe.
PMID- 10780375
TI - The interaction of benzimidazole compounds with DNA: intercalation and groove
binding modes.
AB - Benzimidazole compounds (Fig. 1) have been synthesized to study their DNA-binding
properties. Results obtained with spectroscopy and viscosity measurements
indicate that the binding mode varies from intercalation to groove-binding,
depending on the number of benzimidazole rings (conformation and size of
compounds).
PMID- 10780376
TI - Affinity separation of messenger RNA by thermo-responsive polymer carrying
oligo(dT).
AB - The conjugate between oligo(dT)16 and thermo-responsive polymer, poly(N
isopropylacrylamide), was prepared for isolation of poly(A)+ RNA from total RNA.
The hybridization reaction between the conjugate and poly(A) (average length: 320
base) was equilibrated in 10 min, and all the poly(A) (16 nmol base for 24 nmol
base of conjugate) was precipitated when raising the solution temperature to 35
degrees C. The precipitate was dissolved in water, and poly(A) was dissociated
from the conjugate by heating to 65 degrees C. This separation system was
successfully applied to the isolation of poly(A)+ RNA from total RNA.
PMID- 10780377
TI - DNA analysis by microfabricated capillary electrophoresis device.
AB - The LIGA (Lithographie Galvanoformung Abformung) process using synchrotron
radiation lithography is applied to the microfabrication of capillary array
electrophoresis (CAE) device. Laser-induced fluorescence detection system for the
CAE device has been constructed by the modification of laser confocal
fluorescence microscopy. DNA molecules were detected during migrating in the
microchannels filled with polymer separation matrices under electric field to
optimize the separation conditions for DNA analysis. Based on this observation,
we demonstrated that microfabricated CAE device is realized the fast separation
of DNA.
PMID- 10780378
TI - Rapid detection of the gene of Legionella pneumophila using the fluorescence
polarization with the asymmetric PCR.
AB - We attempted the rapid detection method of Legionella pneumophila by the
asymmetric PCR and the fluorescence polarization. Eleven extracted DNAs from L.
pneumophila serogroup 1 to approximately 6, L. bozemanii, L. dumoffii, L.
gormanii, L. micdadei, and Pseudomonas aeruginosa were amplified by asymmetric
PCR, and the polarization of those products were measured. Only the polarization
of L. pneumophila serogroup 1 to approximately 6 rose within a few minutes after
the beginning of measurement. The sensitivity to L. pneumophila using this method
was 10(3) cells.
PMID- 10780379
TI - Folding transition of long duplex DNA from mammalian cells.
AB - Conformational change in individual giant DNAs from pig liver is studied by use
of fluorescence microscopy. With the addition of spermidine (a trivalent amine),
each DNA chains undergo abrupt transition from an elongated coiled state into a
folded compact state. It is found that the all-or-none characteristics in the
folding transition for the mammalian DNA is similar to that in phage DNAs.
PMID- 10780380
TI - Quantification analysis of splice signal sequences: mutation of 3'-splice signal
sequence and mechanism of unsplicing in a beta-thalassemia pre-mRNA.
AB - Strength of splice signal sequence plays an important role in mammalian pre-mRNA
splicings. In the splicing of human beta-globin thalassemia pre-mRNA, a 25
nucleotide deletion covering the signal sequence at 3'-splice site of intron 1
causes unsplicing of intron 1, while splicing of intron 2 occurs normally. This
gives abnormal mRNA and beta-thalassemia disease. If 3'-splice site of intron 1
is inactivated, two 5'-splice signals of introns 1 and 2 compete with each other
for the 3'-splice site of intron 2. Our quantification analysis revealed that the
5'-splice signal of intron 2 is stronger than that of intron 1, explaining the
mechanism for unsplicing of intron 1.
PMID- 10780381
TI - Statistical analysis of DNA sequencing data (1): accuracy test of DNA data by
partial re-sequencing.
AB - To qualify DNA data, we have developed a statistical method of deciding whether
the DNA data has an acceptable accuracy in sequencing process. The method is to
test the probability of sequencing errors, based on partial re-sequencing. The
method was successfully applied to a yeast mitochondrial DNA which is previously
sequenced (1). The analysis indicates that the entire sequence is very accurate
although we found one base change error on the ND1 gene sequence data by a
partial re-sampling. This method is applicable to any DNA data.
PMID- 10780382
TI - Genome structure of Ri plasmid (2). Sequencing analysis of T-DNA and its flanking
regions of pRi1724 in Japanese Agrobacterium rhizogenes.
AB - We sequenced 42.6 kb including T-DNA and its flanking regions which corresponds
to about 1/5 of entire length of a mikimopine-type Ri plasmid, pRi1724 in A.
rhizogenes. We identified 37 ORFs (Open Reading Frames) including genes in total.
Among them, 20 ORFs are probably new genes. Those ORFs have similarity with those
in Agrobacterium and 9 ORFs of them was newly found on Ri plasmids.
PMID- 10780383
TI - Isolation of cDNAs that cover the entire coding region of a novel human protein
D40.
AB - Previously, we have reported a novel protein, D40, that specifically binds to a
nuclear factor GCF by two-hybrid system. Northern analysis on tumor cell lines
revealed that mRNA of D40 is about 5 kb. To get cDNA clones that cover the total
coding region of D40 protein, approximately 5 x 10(5) clones of a human cDNA
library were screened, and then several positive clones were obtained. RACE was
performed to get the 5' end of the cDNA. DNA sequencing revealed an open reading
frame that encodes a protein with 887 amino acids. in vitro transcription and
translation analysis of D40 revealed that the molecular weight of the protein is
110 to approximately 130 kda.
PMID- 10780384
TI - Chromosomal assignment of a novel human gene D40.
AB - We have previously reported an identification of a novel human cellular factor,
D40. Here, we report the chromosomal localization of the gene that encodes D40.
Fluorescent in situ hybridization (FISH) was performed to determine the
chromosomal region that D40 gene resides. The chromosomes that derived from
normal adult male lymphocytes were hybridized with a mixture of cDNA probes that
cover the entire coding region of D40. D40 gene mapped to the long arm of
chromosome 15q14-15.
PMID- 10780385
TI - Transcriptional regulation of cruxrhodopsin gene from extremely halophilic
archaeon Haloarcula japonica strain TR-1.
AB - Transcription of the cruxrhodopsin (cR) gene in extremely halophilic archaeon
Haloarcula japonica strain TR-1 was investigated using Northern analysis to
quantify message level. In the cell cultures growing in the dark, cR transcript
level remained very low. In contrast, exposure of the cell cultures to light
stimulated transcription of the cR gene. In addition, cR gene transcription was
also induced when Ha. japonica was grown under high oxygen tension and then
shifted to low oxygen tension in the dark. These results suggested that
transcription of the cR gene is regulated by high light intensity and low oxygen
tension.
PMID- 10780386
TI - Molecular cloning of A1-ATPase gene from extremely halophilic archaeon Haloarcula
japonica strain TR-1.
AB - The genes encoding A1-ATPase A- and B-subunits were cloned from Haloarcula
japonica strain TR-1. Nucleotide sequencing analysis of the A1-ATPase gene
revealed that the A- and B-subunits consisted of 586 and 473 amino acids,
respectively. The deduced amino acid sequences of the A- and B-subunits of Ha.
japonica showed high identities with those of Halobacterium salinarum and
Haloferax volcanii. The consensus ATP-binding motif was found in the A-subunit.
PMID- 10780387
TI - Nucleotide sequences of animal mitochondrial tRNAs(Met) possibly recognizing both
AUG and AUA codons.
AB - To elucidate the role of modified nucleosides of tRNA in mitochondrial
translation systems, especially with regard to their codon recognition, we
purified mitochondrial tRNAs(Met) isolated from liver of frog, chicken and rat,
and determined their nucleotide sequences. All of these tRNAs(Met) were found to
possess 5-formylcytidine in the first letter of the anticodon, which is known to
be prerequisite for bovine mt tRNA(Met) to decode AUA codon as well as AUG codon.
These tRNA possesses two pseudeuridines in similar positions, and only chicken
tRNA(Met) had ribothymidine at the first position of the T-loop, which is always
found in the usual tRNAs. Considering that AUA codon is used as five times
frequently as AUG codon in these animal mitochondrial genomes, it is deduced that
5-formylcytidine at the wobble position is essential for the recognition of both
AUA and AUG codons.
PMID- 10780388
TI - Incorporation of two nonnatural amino acids into proteins through extension of
the genetic code.
AB - A novel method of the in vitro incorporation of two nonnatural amino acids into
proteins through extension of the genetic code was developed. The streptavidin
mRNA containing AGGU and CGGG, and chemically aminoacylated tRNA(ACCU) and
tRNA(CCCG) were prepared, then they were added into E. coli in vitro protein
synthesizing system. As a result, two nonnatural amino acids were successfully
incorporated into desired sites of streptavidin.
PMID- 10780389
TI - Correlation between mRNA structure of the coding region and translational pauses.
AB - Discontinuous translational elongation of polypeptides is observed during spider
dragline silk fibroin synthesis (1,2). The repeating segment of one of the two
subunit proteins constituting spider major ampullate (dragline) silk of Nephila
clavipes, Spidroin 2, consists of alternate alanine-rich and proline-rich regions
(3). It was found that the calculated free energy of the secondary structure of
Spidroin 2 mRNA per nucleotide for the alanine-rich region is about the same as
that for the successive proline-rich region. The small stability changes of local
mRNA secondary structures along the mRNA chain suggest that the translational
pauses observed for dragline silk fibroin synthesis may not be correlated with
Spidroin 2 mRNA structure, in contrast to Spidroin 1 mRNA structure which may
explain the translational pauses (4).
PMID- 10780390
TI - Preparation of DNA containing 7-methylguanine as unique lesions.
AB - The predominant adduct produced by both endogenous and exogenous methylating
agents is 7-methylguanine(m7G). Most studies on the repair of m7G reported so far
used methylated DNA as substrates which contained other unintended lesions. In
the presented study, DNA substrates containing m7G as unique lesions were
prepared by DNA polymerase reactions. Using these substrates, damage recognition
of E. coli 3-methyladenine DNA glycosylase II (AlkA) was analyzed. The obtained
results suggested that the repair rate of m7G by AlkA was affected by the
flanking sequence context of the lesion.
PMID- 10780391
TI - MTHFR gene variant is not associated with diabetic nephropathy in Japanese.
AB - Genetic predisposition has been implicated in diabetic nephropathy. The C677T
variant of the MTHFR gene has been suggested to play a role in the development of
not only vascular diseases but also diabetic microangiopathies. By using
polymerase chain reaction-restriction length polymorphism (PCR-RFLP) method using
Hinf I, we investigated whether this variant is associated with diabetic
nephropathy in Japanese. By analysing 274 unrelated Japanese patients with type
II DM with or without nephropathy, there was no significant difference in the
genotype distribution of this variant. The distribution of the three genotypes
were not different among patients with micro- or macroalbuminuria and those
without nephropathy. Although previous reports suggest a role of this variant
with diabetic microangiopathies, our observations suggest that this variant is
does not play an important role in the pathogenesis of diabetic nephropathy in
Japanese.
PMID- 10780392
TI - A possible function of DNA curvature in a vector system that allows efficient
expression of heterologous proteins in CHO cells.
AB - A cis-acting element derived from the nontranscribed spacer region of murine rDNA
allows efficient expression of heterologous proteins in transformed Chinese
hamster ovary (CHO) cells. Analysis of the structural conformation of this cis
acting element revealed that it has a DNA curvature. Whether the DNA curvature
plays any roles in regulating expression of heterologous proteins or not has been
studied.
PMID- 10780393
TI - Antisense oligodeoxynucleotides: useful tool for search and assessment of new
targets for anti-malarial drugs.
AB - We investigated about targeting for new antimalarial drugs using antisense (AS)
oligodeoxynucleotides (ODNs). Synthetic nuclease-resistant ODNs (phosphorothioate
(PS) ODNs and ODNs containing 4'alpha-C-(2-aminoethyl)thymidines (4'-amino ODNs))
which target mitochondrial succinate dehydrogenase (SDH) iron-sulfur subunit
(IP), had antimalarial activity (EC50; about 1.0 microM). Furthermore we showed
that intra-parasitic SDH IP mRNA levels, which were detected using quantitative
RT-PCR assay, were decreased 13% of control after the 24 h expose to SDH IP AS.
From the results, we conclude that SDH has potential as the target for novel
antimalarials, and AS ODNs is effective for search and assessment of targets for
new antimalarial drugs.
PMID- 10780394
TI - Fluorescent probe and permeability to cells of isopoly (S-carboxymethyl-L
cysteine) derivative of nucleic acid bases.
AB - Isopoly(S-carboxymethyl-L-cysteine) derivatives of nucleic acid bases were found
to form stable complex with oligo-DNA in vitro. Fluorescent probed isopoly(S
carboxymethyl cysteine) derivatives of nucleic acid bases were prepared as
antisense oligomers. The transfection of the oligomer into cells was carried out
by HVJ-liposome method. Fluorescence was observed from the cells treated with HVJ
liposome including fluorescent probed oligomers.
PMID- 10780395
TI - Comparison of thermodynamic stabilities between PNA (peptide nucleic acid)/DNA
hybrid duplexes and DNA/DNA duplexes.
AB - We have examined quantitatively stabilities of PNA/DNA hybrid duplexes with
identical nearest-neighbor base pairs and compared stabilities between PNA/DNA
and DNA/DNA. The average difference of stabilization energy of the short PNA/DNA
was 0.9 kcal mol(-1), which suggests that the stability of the hybrids with
identical nearest-neighbor base pairs can be predicted with the nearest-neighbor
model as well as those of nucleic acid duplexes.
PMID- 10780396
TI - Positional effect of single bulge nucleotide on PNA(peptide nucleic acid)/DNA
hybrid stability.
AB - We report positional effect of bulge nucleotide on PNA/DNA hybrid stability. CD
spectra showed that PNA/DNA hybrids required at least seven base pairings at a
stem region to form a bulged structure. On the other hand, DNA/DNA could form
bulged structure when there are only four base pairings adjacent to the bulge
nucleotide. We discuss why PNA requests such a many base pairings to form bulged
structure from a nearest neighbor standpoint.
PMID- 10780398
TI - Direct laser trapping of single globular DNA molecules.
AB - We show herein that a single T4 phage DNA molecule which was transformed from
coiled to globular state, was trapped directly by Nd:YAG laser (1064 nm). We also
estimated trapping force of globular DNA molecules.
PMID- 10780397
TI - Preparation and evaluation of ODN conjugates with polycation comb-type copolymer.
AB - Oligodeoxynucleotide (ODN) conjugates with the polylysine comb-type copolymer
having an ability to promote and stabilize duplex and triplex DNA formation were
prepared. 5'-Aminated ODN was succinylated with succinic anhydride. The resulting
ODNs having carboxyl terminus were coupled with epsilon-amino groups of the comb
type copolymer using water soluble carbodiimide. The conjugate free from
unconjugated ODNs was obtained by gel permeation chromatography. The resulting
conjugate maintains ability to form duplex and triplex DNA as estimated by
melting curve analysis. Both specificity and stability of the triplex DNA
formation were increased by employing the ODN-copolymer conjugates compared to
those with their mixture.
PMID- 10780399
TI - Rapid and inexpensive recovery method of DNA fragments from agarose and
polyacrylamide gels by a cotton-wool column tube.
AB - We developed a rapid, convenient, simple, and inexpensive method for isolating
pure DNA from agarose and polyacrylamide gels using cotton wool tubes. DNA
fragments ranging in size from 193-23,130 bp can be easily recovered within 2
hours by centrifugation through cotton wool from gel slices. The recovery rate of
this method is 35% to 50%, when estimated for isolation of lambda DNA-HindIII
fragments. We have also recovered 700-bp polymerase chain reaction (PCR) products
using cotton wool tubes from electrophoresis on both a 0.8% agarose gel and a 6%
polyacrylamide gel, in which satisfactory yields of more than 50% were obtained.
The DNA thus recovered in this way is biologically active and can be used as a
substrate for further experimental procedures without additional purification
steps.
PMID- 10780400
TI - Immobilization of DNA by UV irradiation and its utilization as functional
materials.
AB - The water-insoluble DNA film was successfully prepared by UV irradiation. The DNA
film was stable in water. It could effectively accumulated the DNA-binding
intercalating materials, such as ethidium bromide, dibenzo-p-dioxin and
benzo[a]pyrene, in their aqueous solutions. On the other hand, DNA was
immobilized onto nonwoven cellulose fabrics, also by the UV irradiation. The DNA
immobilized cloth was found to bind silver ions. The DNA-cloth containing silver
ion showed antibacterial activity. The water-insoluble DNA prepared by UV
irradiation has a potential ability to serve as biomaterials for medical,
engineering and environmental objects.
PMID- 10780401
TI - A facile synthesis of DNA oligomers with modified backbones via the
phosphoramidite method without nucleoside base protection.
AB - A convenient synthesis of DNA oligomers with modified back bones including
phosphorothioates and phosphotriesters has been developed on the basis of the
phosphoramidite strategy without nucleoside base protection. In this synthesis, a
new, convenient method for the preparation of N-free-5'-O-dimethoxytrityl-2'
deoxyribonucleoside by the direct O-selective dimethoxytritylation of the parent
nucleosides has also been disclosed.
PMID- 10780402
TI - Trityl mass-tags for encoding in combinatorial oligonucleotide synthesis.
AB - Combinatorial libraries of oligonucleotides on beads were synthesised by a split
and-mix strategy using 5'-DMTr- or 5'-Fmoc- nucleoside phosphoramidites. Trityl
moieties with different masses were used to encode for the bases coupled at each
step in the synthesis of oligonucleotides selected by hybridisation from the
libraries. Tags orthogonal to the nucleotides added were produced by coupling
amines of different MW to an activated carboxyl group(s) on the trityl moiety.
Tags can be released from the support by laser irradiation and measured directly
by TOF without matrix. Alternatively, they may be released by an acidic treatment
and then analysed by (MA)LDI-TOF.
PMID- 10780403
TI - Toward artificial ribonucleases: design and synthesis of 2'-O
methyloligonucleotides with a terpyridine-copper(II) complex.
AB - In order to construct an antisense 2'-O-methyloligonucleotide with an internal
terpyridine-Cu(II) complex, a novel synthon was synthesized. This synthon was a
2'-deoxy-uridine-3'-phosphoramidite derivative with a terpyridine group at the 5'
O and a dimethoxytritylated hydroxypropyl group at the C-5. The antisense agent
cleaved the RNA site-specifically and in a moderate yield.
PMID- 10780404
TI - Artificial DNAs with metal-assisted base pairs.
AB - Two types of artificial beta-C-nucleosides, 2 and 3, were newly synthesized,
which possess a metal chelating site (2-aminophenol and catechol, respectively)
at the nucleobase moiety. These nucleosides are expected to form metal-assisted
base pairs in oligonucleotides and thereby to control high-order structures and
functions of DNAs.
PMID- 10780405
TI - Synthesis and properties of oligonucleotides containing 2'-pyrenylalkyluridine.
AB - The synthesis, binding and fluorescence properties of oligonucleotides containing
the uridine modified at the 2'-position by a pyrene group using different length
of linker arm have been described. It is demonstrated that the oligonucleotides
possessing a C3-amide group at the 2'-position display an enhanced signal of the
pyrene monomer fluorescence upon binding to DNA segments.
PMID- 10780407
TI - Does 29-mer RNA hairpin of the HIV-1 TAR RNA sequence bind magnesium? 19F-NMR and
modelling studies.
AB - 5-Fluorouridine residues have been introduced into functionally important bulge
and loop regions of 29-mer HIV-1 TAR RNA hairpins I and II to study Mg2+ and Ca2+
binding using 19F-NMR spectroscopy. There was no substantial binding detected up
to 20-molar excess in case of both cations, whereas association of argininamide,
used as a reference ligand, could be detected at less than 1-molar excess. The
deltadelta 19F value of 1.93 ppm observed for (F)U23 upon argininamide binding is
in agreement with former NMR studies of TAR RNA/argininamide complex. However,
obtained results do not confirm U38 x A27 x U23 base-triple formation. The
unmodified HIV-1 TAR RNA hairpin resulted from 600 ps in aqua molecular dynamics
simulation was subjected to a molecular mechanics modelling of Mg+ binding.
PMID- 10780406
TI - Study on RNA structure by pyrene-labeled 2'-O-methyloligoribonucleotides.
AB - Properties of 2'-O-methyloligoribonucleotides containing 2'-O-(1
pyrenylmethyl)uridine were investigated as the fluorescent probe to search the
single strand regions on RNA secondary and tertiary structure. The pyrene-labeled
2'-O-methyloligoribonucleotide (OMUpy) showed remarkable increase of fluorescence
intensity to 333-fold at 375 nm when hybridized with the complementary
oligoribonucleotide. When OMUpy, complementary to loop or stem regions, was
applied to E. coli 5S-rRNA, the fluorescence intensities were increased in a
sequence specific manner. The difference of the fluorescence intensities
corresponds to the higher-order structure of 5S-rRNA, suggesting that pyrene
labled 2'-O-methyloligoribonucleotide can be applicable to search single strand
regions of RNA.
PMID- 10780408
TI - DNA HOMO as a new landmark for nucleic acid properties. ab initio calculations
and experimental mapping.
AB - Of the non-covalent binding forces in DNA-drug or DNA-protein interaction,
electrostatic interaction, stacking interaction, hydrogen bonds and hydrophobic
effect have been well established. However, only a few HOMO-LUMO interaction in
DNA have been reported. We examined the ab initio calculations of B-DNA duplex 5
mers. Based on the calculated results, we investigated the mapping of HOMO
experimentally and found that DNA cleavage patterns with Co(II) and BPO (Benzoyl
peroxide) were in good agreement with the ab initio calculation results.
PMID- 10780409
TI - N6-methoxyadenine in damaged DNA has two faces in property of Watson-Crick base
pairing.
AB - In order to investigate mutation mechanism with oxyamine, two DNA dodecamers
containing 2'-deoxy-N6-methoxyadenosine have been synthesized and their crystal
structures have been determined. The dodecamers are associated in B form
duplexes. The methoxy groups attached to the adenine bases do not affect the DNA
conformation significantly. Electron densities clearly show that N6
methoxyadenine moiety forms Watson-Crick type pairing with both, thymine and
cytosine bases. Such two faces in pairing are the origin of pyrimidine transition
mutation.
PMID- 10780410
TI - Preparation of 2'-deoxyribonucleosides with an identically 2H/13C-labeled sugar
residue.
AB - Thymidine with the stereoselectively 2H/13C-Labeled sugar moiety, (2'R)(5'S)
[1',2',3',4',5'-(13)C5;2',5'-(2)H2]-thymidine, was synthesized from uniformly 13C
labeled glucose, via the selectively deuterated ribose derivative prepared by the
stereo-controlled deuteride transfer reactions. The labeled sugar moiety of the
thymidine was then transferred to 2'-deoxyadenosine, 2'-deoxyguanosine, and 2'
deoxyuridine, by the enzymatic transglycosylation reactions by purine and
pyrimidine nucleoside phosphorylases, in good yields. Labeled 2'-deoxyuridine was
chemically converted to 2'-deoxycytidine. Consequently, all of the 2'
deoxynucleosides prepared by this method has the identically labeled sugar
moiety. By using DNA oligomers containing the identically labeled sugar residue
for NMR studies, any possible complexity in NMR data analyses expected to be
observed for DNA oligomers containing variously labeled nucleosides can be
minimized.
PMID- 10780411
TI - Chemical synthesis of novel base pairs and their enzymatic incorporation into
DNA.
AB - A novel base pair, 2-amino-6-(N,N-dimethylamino)purine (denoted x) and the
counter part, pyridin-2-one (denoted y) were designed. The bulky 6-dimethylamino
group of x is expected to eliminate base pairing with all natural bases. The
phosphoramidite of x for DNA templates and the 2'-deoxyribonucleoside
triphosphate of y (dyTP) for a substrate were synthesized, and the selectivity of
the enzymatic incorporation of dyTP opposite x in the templates was examined.
dyTP was preferentially incorporated opposite x than canonical dNTPs by Klenow
fragment of Escherichia coli DNA polymerase I. While dyTP was also incorporated
opposite A and G, the misincorporation was suppressed in the presence of dTTP and
dCTP, respectively.
PMID- 10780412
TI - Synthesis of 4'-substituted nucleosides and their biological evaluation.
AB - 4'-C-Ethynyl-beta-D-arabino- and 4'-C-ethynyl-beta-D-2'-deoxy-ribo-pentofuranosyl
pyrimidines were synthesized. Most of these 4'-ethynyl nucleosides showed
interesting biological activities.
PMID- 10780413
TI - Interaction of a novel antitumor agent TAS-103 with DNA.
AB - Interaction of a novel antitumor agent TAS-103 with DNA has been studied by a
variety of methods including thermal melting study, UV-Visible spectroscopy, 1H-
and 31P-NMR spectroscopy. Thermal melting study indicated that TAS-103 stabilizes
the double stranded form of DNA and the relative binding strength of TAS-103 is
equal to that of ethidium bromide (EtBr). UV-Visible spectroscopy demonstrated
that titration curves are nearly identical with all DNA oligomers producing a
hypochromic and hypsochromic effect. A hypsochromic effect of TAS-103 is differ
from typical intercalators such as EtBr and Actinomycin D that exhibit a
bathochromic effect. 1H- and 31P-NMR spectroscopy revealed that TAS-103 has
mainly two binding modes. Major binding mode is outside binding and minor binding
mode is intercalation.
PMID- 10780414
TI - Disturbance of genetic information by a ribonucleotide analogue.
AB - The synthetic base analogue, 6H,8H-3,4-dihydropyrimido[4,5-c][1,2]oxazin-7-one
(P), can efficiently base pair with A and G. We have previously demonstrated that
the deoxyribonucleoside of P (dP) is highly mutagenic and that this is due to the
ambiguous base pairing ability of P. In this work, we have shown that the
ribonucleoside triphosphate of P (rPTP) induces C to U mutation on an in vitro
model of retroviral genomic RNA replication pathway. This mutation induction by
rPTP may be specific to retroviruses, since host genomic DNA should not be
affected by such a ribonucleotide analogue, although temporary transcription
translation errors may occur.
PMID- 10780415
TI - Cytotoxic mechanism of 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine (ECyd).
AB - The molecular mechanism of cell death induced by 1-(3-C-ethynyl-beta-D-ribo
pentofuranosyl)cytosine (ECyd: Figure 1), a potent inhibitor of RNA synthesis,
was performed using mouse mammary tumor FM3A cells and human fibrosarcoma HT1080
cells. ECyd induced the characteristics of apoptosis on these cells, such as
morphological changes, DNA fragmentations (Figure 2), and caspase-3-like protease
activation. General caspases inhibitor (Z-Asp-CH2-DCB) inhibited these changes
and cell death. We also found that ECyd induced DNA and 28S ribosomal RNA (rRNA)
fragmentations. Though the mechanisms of rRNA fragmentations haven't revealed, it
suggests that translational function of the treated cells should be disturbed.
These results indicate that antitumor mechanism of ECyd are characteristics of
apoptosis on the cells and rRNA fragmentations is one of the death events
resulted inhibition of RNA synthesis.
PMID- 10780416
TI - Photo-regulated duplex- and triplex-formation of the modified DNA carrying
azobenzene.
AB - The duplex- and triplex- forming activity of oligonucleotide was photo-regulated
by using the isomerization of azobenzene in the side chain. When the azobenzene
was isomerized from the trans-form to the cis-form by photo-irradiation, the
melting temperatures of the duplex and triplex between the oligonucleotide and
its complementary counterpart were significantly lowered.
PMID- 10780417
TI - Promotion mechanism of triplex DNA formation by comb-type polycations:
thermodynamic analyses of sequence specificity and ionic strength dependence.
AB - We have previously reported that in the presence of poly (L-lysine)-graft-Dextran
(PLL-g-Dex) copolymer, the binding constant of the pyrimidine-motif triplex
formation at neutral pH is about 100-times higher than that observed without any
triplex stabilizer. Here, to explore the mechanism of the promotion effect of the
PLL-g-Dex copolymer at neutral pH, the sequence specificity and the ionic
strength dependence of the pyrimidine-motif triplex formation was examined in the
absence or presence of the copolymer. The sequence specificity of the pyrimidine
motif triplex formation at neutral pH in the presence of copolymer was almost
similar to that at acidic pH without the copolymer. As the concentration of
magnesium cation increased, the binding constant of the pyrimidine-motif triplex
formation without the copolymer increased. On the other hand, the binding
constant of the pyrimidine-motif triplex formation in the presence of the
copolymer decreased upon the increase in the concentration of magnesium cation.
Considering these results in light of counterion condensation (CC) theory, we
conclude that the copolymer does not hinder the sequence specificity of the
triplex formation, and isolates the triplex formation from the CC effect, which
may lead to a net increase in entropy change upon the triplex formation,
providing a favorable component to binding constant of the triplex formation.
PMID- 10780418
TI - Acceleration of DNA strand exchange by polycation comb-type copolymer.
AB - Polycation comb-type copolymers which are composed of poly(L-lysine) backbone and
dextran graft chain (PLL-graft-Dex) accelerated DNA duplex and triplex formation
and stabilized under physiologically relevant condition remarkably. In this
study, we have examined the ability of polycation copolymer in promoting strand
exchange between duplex DNA and its complementary single-stranded DNA. It was
demonstrated that the strand exchange rate was considerably accelerated by the
polycation comb-type copolymer.
PMID- 10780419
TI - Strand invasion by DNA-peptide conjugates and peptide nucleic acids.
AB - Peptide nucleic acids (PNAs) and conjugates between oligonucleotides and cationic
peptides possess superior potential for strand invasion at complementary
sequences. We discovered that oligonucleotide-peptide conjugates and PNAs fall
into three classes based on their hybridization efficiency; i) those
complementary to inverted repeats within AT-rich region hybridize with highest
efficiency; ii) those complementary to areas adjacent to inverted repeats or near
AT-rich regions hybridize with moderate efficiency; and iii) those complementary
to other regions do not detectably hybridize. The correlations between oligomer
chemistry, DNA target sequence, and hybridization efficiency that we report here
have important implications for the recognition of duplex DNA.
PMID- 10780420
TI - Isopoly(S-carboxymethyl-L-cysteine) derivatives of nucleic acid bases: effects of
D-cysteine derivatives on the interaction with DNA.
AB - Isopoly(S-carboxymethyl-D-cysteine) derivatives of nucleic acid bases were
prepared to study the effect of chirality on the complex formation with oligo
DNA. The D-cysteine unit in the L-cysteine oligomer caused decrease of Tm for the
complex with DNA.
PMID- 10780422
TI - Quantitative detection of a DNA ligase reaction on a quartz-crystal microbalance.
AB - We report here kinetic analyses of DNA ligation by using a DNA-immobilized quartz
crystal microbalance (QCM), which enables in situ real-time monitoring of both
the binding of ligase and ligation reaction on DNA strands, as mass changes.
PMID- 10780421
TI - Recognition control of the nucleic acid model through conformational switching of
nucleobase induced by borate ester formation of cis-2',3'-diol.
AB - A novel nucleic acid model that possessed 5'-amino-5'-deoxyuridine at alpha- and
gamma-position of L-glutamic acid through amide linkage using 5'-amino group was
synthesized and the conformation and the hybridization properties were studied.
The complex of alpha-PRNA with complementary DNA/RNA was more stable than the
corresponding natural duplex in the absence of borate. Its recognition ability
was however lost when borax was added to the solution.
PMID- 10780423
TI - DNA coated with cationic fullerene derivative. A possible microwire in water.
AB - Fullerene derivative 2 carrying pyridinium cation bound to sonicated calf thymus
DNA in water. The binding ratio was 1 fullerene unit to 1 phosphate residue,
giving the complex where DNA strand is seemingly coated with electron-conducting
fullerenes. Cyclic voltammetry shows three-step redox couples in the complex, and
the current peaks were broadened and shifted to positive side as compared to
uncomplexed 2. Binding of 2 onto grooves of DNA double helix was suggested.
PMID- 10780424
TI - Ultra-high resolution DNA structures.
AB - This paper describes the progress in our efforts at producing ultra-high
resolution (< 0.8 A) DNA structures using advanced cryo-crystallography and
synchrotron. Our work is aimed at providing reliable geometric (bond length and
bond angle), electronic and motional information of DNA molecules in different
conformational contexts. These highly-reliable, new structures will be the basis
for constructing better DNA force-field parameters, which will benefit the
structural refinement of DNA, protein-DNA complexes, and ligand-DNA complexes.
PMID- 10780425
TI - Comparison of the efficiency of various coupling systems in the acylation of
model secondary amines with thymin-1-ylacetic acid.
AB - Peptide nucleic acids (PNAs) make a promising group of DNA analogues. The
backbone of typical PNA oligomers is composed of N-(2-aminoethyl)glycine units,
linked by the peptide bonds. The backbone secondary amine groups are acylated
with carboxyalkyl derivatives of nucleobases. One of the PNA synthesis step
causing some problems is the acylation of the monomer backbone with the
nucleobase derivatives. The aim of the study was to compare the efficiency of
various coupling systems in the acylation. Simple model compounds (piperidine and
proline) were used, as well as equimolar amounts of the coupling reagents.
Selected systems based on carbodiimides, aminium or phosphonium salts, mixed
anhydride, and active esters were tested.
PMID- 10780426
TI - Formation of 8-nitroguanine from 2'-deoxyguanosine by NO/O2 system.
AB - We investigated the reaction of 2'-deoxyguanosine (dGuo) with NO/O2 gas mixture
under physiological condition and detected 8-nitroguanine, which is known as a
novel DNA lesion caused by peroxynitrite (ONOO-). The yield increased with
increase in the ratio of O2 and pH. The reaction mechanism is discussed.
PMID- 10780427
TI - The relationship between metal-metal distance of two metal ions chelated complex
and RNA cleavage activity.
AB - We prepared a series of ligands possessing two binding sites for metal
coordination: in each ligand molecule, two binding sites with the same
functionality (2,2'-dipicolylamino group) were placed at the of various methyl
arenes. Thus, the distances between the metal binding sites were different from
ligand to ligand. We examined the rate of the hydrolysis of RNA dimer catalyzed
by La3+ ion binuclear complexes of the ligands. The catalytic activity of the
binuclear complexes increased as the distance between the metal binding sites was
decreased.
PMID- 10780428
TI - An efficient method for the synthesis of [2-(15)N]guanosine and 2'-deoxy[2
(15)N]guanosine derivatives.
AB - Nucleophilic substitution reaction of 6-chloro-2-fluoro-9-beta-D-ribofuranosyl-9H
purine derivative, prepared from guanosine, with potassium [15N]phthalimide at 40
degrees C for 9 h in DMF, followed by hydrolysis, afforded [2-(15)N]guanosine
derivative efficiently. The corresponding 2'-deoxy derivative was also
synthesized through a similar procedure.
PMID- 10780429
TI - Synthesis and properties of oligonucleotides containing 2'-O-methyl-2
thiouridine.
AB - New methods to synthesize 2'-O-methyl-2-thiouridine and its phosphoramidite
building block for incorporation into oligonucleotides were developed.
Oligonucleotides containing 2'-O-methyl-2-thiouridine were expected to be
favorable as antisense agents in several respects, i.e., nuclease resistance,
stable RNA duplex formation, and exact base recognition. Therefore, to make them
clear, we synthesized oligonucleotides having 2'-O-methyl-2-thiouridine and
analyzed their properties in detail.
PMID- 10780430
TI - Synthesis and properties of novel antisense oligonucleotides bearing an
anthraquinone moiety at an internucleotide linkage.
AB - Antisense oligonucleotides bearing an anthraquinone moiety at an internucleotide
linkage were synthesized utilizing the stereoisomers of anthraquinone
incorporated T-C dimer phosphoramidite derivatives. Some physicochemical
properties of the anthraquinon bearing oligomers were investigated.
PMID- 10780431
TI - Synthesis of telomere-mimic carbocyclic 5'-nor oligodeoxynucleotides.
AB - Telomere-mimic S-ODNs have been synthesized and examined their effects on the
proliferation of human tumor cell lines by XTT assay. Furthermore, the guanosine
derivatives of carbocyclic 5'-nor nucleoside were synthesized.
PMID- 10780432
TI - Interaction of cationic alpha-helical peptide with phosphorothioate DNA hybrid.
AB - Synthetic amphiphilic alpha-helix peptides were found to bind to stabilize double
or triple stranded DNA. The stabilization effect was significant for cationic
alpha-helix peptides which indicated the importance of electrostatic interaction
of positive charge of peptide and negative charge of DNA. It should be also
pointed out that hybrid double or triple helical complexes containing
phosphorothioate oligonucleotide were stabilized to a larger extent respect to
phosphodiester oligonucleotides. Since it was shown that cationic amphiphilic
alpha-helix peptide accelerate membrane permeability of DNA, the present study
can provide a solution for the problems of antisense or triplex oligonucleotide
in their practical application.
PMID- 10780433
TI - Interaction of amphiphilic cyclic peptide with double and triple stranded DNA.
AB - It was found that Gramicidin S (GS) with intramolecular antiparallel beta-sheet
structure could bind to and thermally stabilize double and triple stranded DNA.
UV melting study revealed that GS stabilized mixed sequence dsDNA in the presence
of Mg2+ (deltaTm = +6.0) but it stabilized dsDNA with homosequence only in the
absence of Mg2+. It should be pointed out that GS specifically stabilized the
third strand (Hoogsteen base pair) but not double strand (Watson-Crick base pair)
in triple helix DNA.
PMID- 10780434
TI - Photoreactivity of 5-iodouracil-containing DNA-Sso7d complex.
AB - X-ray structure of DNA-Sso7d complex indicated that binding of this protein
causes sharp DNA bending. In order to examine whether this protein also causes
DNA bending in solution, photoreactions of 1U-substituted DNA in the presence and
the absence of Sso7d protein were investigated. It was found that the unusual
intrastrand hydrogen abstraction at methyl of adjacent thymine occurred
efficiently at the observed bending site of crystal structure.
PMID- 10780435
TI - DNA binding affinity of pentapeptides selected from combinatorial library.
AB - The combinatorial method has been applied to determine peptide ligands to the
duplex DNA by using the solid-state pentapeptide library and the target-DNA
conjugated magnetic beads. Seventy-one sequences were determined as ligands for
AT duplex. Interestingly, hydrophobic amino acids such as Phe, Ile and Gly were
most frequently determined. Relative binding affinity of the selected
pentapeptides with the various DNA sequences was estimated by ethidium
displacement assay in 10 mM SHE buffer. FQGII constituted of amino acids that
were most frequently determined in the random screening showed highest binding
affinity to the duplex DNA.
PMID- 10780436
TI - Construction of nonnatural DNA library.
AB - Nonnatural DNA polymerase substrates which contain many kinds of modified
functional groups are synthesized. The C-5 position of dUTP was modified by amino
acid, saccharide. These compounds were incorporated on a DNA double strand using
E. Coli DNA polymerase. This nonnatural DNA library contains a larger diversity
than native DNA or RNA and has a higher chemical stability than RNA. This library
will be useful for in vitro selection study, combinatorial chemistry, and the
preparation of supramolecular structures.
PMID- 10780437
TI - Extended in vitro selection for synthesis of novel molecular recognition
oligonucleotide derivatives.
AB - In vitro selection of RNA aptamer containing biotin-carrying nucleotide was
carried out used for development of a new type of molecular sensor. Cytidine 5'
triphosphate (CTP) carrying biotinyl group at the N6-position was used in this
technique. A pool of biotin-containing RNAs, which binds specifically to
adenosine 5'-triphosphate (ATP), was obtained and used for competitive binding
assay of ATP. The selected nonnatural RNA possesses many biotinyl groups to
render it a high sensitivity toward ATP.
PMID- 10780438
TI - Combinatorial approach to development of peptides that recognize DNA tetraloops.
AB - We report recognition system for DNA tetraloops (dA1G2G3C4T5T6C7G8G9C10C11T12
(core) and dAGGCTTCGGCCT (AP2); X = abasic nucleotide) by peptides selected with
combinatorial chemistry. As a result, peptides with Thr/Glu/His and Gln/Asp were
obtained in binding of DNA core and AP2, respectively.
PMID- 10780439
TI - DNA hybridization sensor utilizing [Os(5,6-dmphen)3]2+ by square wave
voltammetry.
AB - DNA hybridization detection utilizing [Os(5,6-dmphen)3]2+ (tris(5,6-dimethyl
phenanthroline) osmium(II/III)) as hybridization indicator was studied, because
[Os(5,6-dmphen)3]2+ has the most largest association constant (K2+) and high
current density in osmium methyl substituted phenanthroline complexes. As the
result, target DNA could be detected selectively ranging from 6.9 x 10(-10) to
6.9 x 10(-5) g/mL using square wave voltammetry.
PMID- 10780440
TI - Metal ion-directed DNA recognition by chelating DNA ligands.
AB - Novel DNA ligand bearing oxine and pyridinium group has been synthesized. The DNA
binding of this ligand was regulated by coexisting Cu2+ over the range of more
than three orders in magnitude of binding constant. This should be due to the
metal-mediated dimerization of the ligand and concomitant emergence of cationic
charges. There were definite two DNA binding modes for the ligand dimer depending
on the P/L ratio.
PMID- 10780441
TI - Highly sensitive detection of target gene by electrochemical method.
AB - A highly sensitive DNA sensing method was developed using electrochemically
active ligand. This method is based on the detection of electric current
generated by electrochemically active ligand concentrated on the electrode.
Electrochemically active, intercalating ligand can bind to the double stranded
DNA of target gene sequence on the electrode, where the complementary single
strand is immobilized as a probe. We succeeded in the detection of 0.1 amol
target gene. The technique was applicable to the detection of 0.1-10 amol gene.
PMID- 10780442
TI - Structural analysis of the complex of a distamycin analogue with the Dickerson
dodecamer 13C labeled at 5'-carbons using NMR spectroscopy.
AB - Structural analysis of the complex of a distamycin analogue (Tallimustine) with
the Dickerson dodecamer d(C*G*C*G*A*A*T*T*C*G*C*G) [N*:[5'-(13)C]nucleotide] was
performed by NMR spectroscopy and the results will be described in detail.
PMID- 10780443
TI - Conformational classification of functional nucleic acids.
AB - The kink parameters would provide the tolerant aspect for irregular helical
structure of nucleic acid. Using these kink parameters, the classification of
conformation space was carried for the functional nucleic acid molecules. The
kink parameters could afford us the simple structural aspects about the
constructive parts of functional molecules. Local elastic kink phenomena can be
classified by rod like models with the combination of kink parameters. The
constructive parts, such as the stable tetra nucleotides loop, U-turn
conformation and adenosine platform, were selected and the statistical analyses
were carried on the parameters calculated by program BIOCON.
PMID- 10780444
TI - The guanosine binding mechanism of the Tetrahymena group I intron.
AB - The Tetrahymena group I intron catalyzes self-splicing through two consecutive
transesterification reactions, using a single guanosine-binding site (GBS). In
this study, we constructed a model RNA that contains the GBS and a conserved
guanosine nucleotide at the 3'-terminus of the intron (omegaG). We determined by
NMR the solution structure of this model RNA, and revealed the guanosine binding
mechanism of the group I intron. The G22 residue, corresponding to omegaG,
participates in a base triple, G22 xx G3 x C12, hydrogen-bonding to the major
groove edge of the Watson-Crick G3 x C12 pair. The G22 residue also interacts
with A2, which is semi-conserved in all sequenced group I introns.
PMID- 10780445
TI - In situ monitoring of peptide-bound dsDNA selection on a GCN4-bZIP-immobilized
quartz-crystal microbalance.
AB - A highly sensitive 27 MHz quartz-crystal microbalance (QCM) was applied as a
device of dsDNA in vitro selection. When GCN4-bZIP peptides were immobilized on
the small Au electrode of the QCM, dsDNAs having TGACTCA sequences could be
mainly selected from DNA library having a 15-bp random region, which was
consistent with the sequence observed by X-ray crystallography.
PMID- 10780447
TI - Recognition and cleavage of double-stranded DNA by yeast VMA1-derived
endonuclease.
AB - DNA endonuclease derived from the yeast VMA1-gene product recognizes and cleaves
31 base-pairs of double-stranded DNA (dsDNA). Mixtures of the endonuclease (VDE)
with a full DNA substrate consisting of 34 base-pairs, with nicked substrates
each having a nick in either DNA chain, and with cleaved substrates each having a
cleaved-off chain are prepared. Molecular weights (MWs) of eluted peaks from gel
filtration columns were estimated from elution profiles in the presence of Mg2+
ions. Each mixture exhibited an elute peak at about 63k MW, larger than the MW of
VDE unbound to dsDNA. This indicates that VDE and dsDNA substrates form stable
complexes. The mixture of VDE either with the full substrate or with the nicked
substrate having a nick in the anti-sense chain eluted an additional 25k-MW peak,
which presumably corresponds to a cleaved product. The complex of VDE with the
full substrate was eluted at 62k-MW location in the absence of Mg2+ ions and
yielded a single crystal. Stable complexes of VDE either with the dsDNA
substrates or with the cleaved products are obtainable.
PMID- 10780446
TI - Abasic site recognition mechanism by the Escherichia coli exonuclease III.
AB - In order to elucidate the mechanism of AP site recognition by Echerichia coli
exonuclease III (exoIII), site-directed mutagenesis of the Tyr109, the Trp212,
and the Phe213 residues, which were conserved in the type II AP endonuclease from
various organisms and located in the vicinity of the catalytic site, was
performed. The exoIII-W212S mutant lacked any detectable AP endonuclease activity
and binding ability to the duplex DNA containing an AP site, while the exoIII
Y109S and exoIII-F213W mutants retained a low level of activities (13% and 83%,
respectively, compared with wild-type exoIII). This study suggests that the
Trp212 is an important component for abasic site recognition by the E. coli
exonuclease III.
PMID- 10780448
TI - The functional analysis of 4.5S RNA in ribosomal translocation.
AB - 4.5S RNA is a stable 114-nucleotide RNA of the bacterium Escherichia coli (E.
coli). We found that 4.5S RNA have the ability of binding EF-G using gel mobility
shift assay. Increasing in the concentration of GDP increase the binding activity
of 4.5S RNA to EF-G. Based on these data, we propose that 4.5S RNA release EF-G
from ribosome.
PMID- 10780449
TI - A role of the C-terminal region adjacent to the zinc-fingers in the DNA binding
ability of Rme1p, a regulator of meiosis in S. cerevisiae.
AB - Rme1p is a zinc-finger protein and has a pivotal role in control of meiosis in
Saccharomyces cerevisiae. The DNA binding domain of Rme1p consists of three zinc
finger segments and the C-terminal 16 amino acid residues (called C-TR). To
examine the role of C-TR, a series of mutant Rme1p fused with maltose binding
protein (MBP) were constructed, purified, and characterized, in terms of the DNA
binding ability. The basic amino acid residues R287 and K290, and the hydrophobic
residues F288, L292, 1295, and L296 play an important role for DNA binding,
suggesting that the C-TR forms an amphipathic alpha-helix. Also, it was shown
that the mutations in the basic amino acid residues abolish the repression and
inhibition of spore formation by Rme1p in vivo. Hence, the C-TR is important for
in vivo function of Rme1p.
PMID- 10780450
TI - NMR signal assignment of the polyuridine tract of the single-stranded RNA
complexed with Sxl RBD1-RBD2 by using residue selective [5-(2)H]uridine
substitutions.
AB - Using [5-(2)H]uridine phosphoramidite, we synthesized a series of 2H-labeled
Drosophila Sex-lethal (Sxl) target RNAs, in which all the uridine residues except
one were specifically replaced by [5-(2)H]uridine. By observing the H5-H6 cross
peaks of RNA in the TOCSY spectra, we unambiguously assigned all the base proton
resonances of the target RNA in a Sxl x RNA complex. Furthermore, it was shown
that Sxl differently recognizes A and G in a position prior to the polyuridine
tract.
PMID- 10780451
TI - Inhibitory effects of of L-2'-deoxyguanosine 5'-triphosphate (L-dGTP) and L-2'
deoxythymidine 5'-triphosphate (L-dTTP) on human telomerase.
AB - Telomerase, which synthesizes telomeric DNA in eukaryotic cells, is classified as
a reverse transcriptase. To clarify the recognition of 2'-deoxyribonucleoside 5'
triphosphate (dNTP) chirality by telomerase, we studied the inhibitory effects of
L-dGTP on HeLa cell telomerase activity using a quantitative 'stretch PCR' assay.
L-dGTP had a weakly inhibitory effect (IC50 = 200 microM) in the presence of 10
microM dGTP. This effect was less obvious when the concentration of dGTP was
higher. L-dTTP had a similar inhibitory effect. These findings suggest that
telomerase may bind to L-dGTP and L-dTTP, and that the ability of telomerase to
bind to dGTP or dTTP is changed.
PMID- 10780452
TI - Ubiquitination of the transcriptional coactivator p300 during retinic acid
induced differentiation.
AB - Transcriptional coactivator p300 plays an important role in differentiation
processes of various cell lines. In this report, we examined levels of p300
protein and the related protein, CREB binding protein (CBP), during the retinoic
acid (RA)-induced differentiation of F9 cell. As a result, the level of p300
protein began to decrease at 36 h after treatment with RA dramatically, however,
the level of CBP protein did not alter. Moreover, ubiquitinated p300 protein was
only detected in differentiated F9 cells. These results suggest that p300 protein
is possibly degraded via the ubiquitin-dependent pathway during the RA-induced
differentiation of F9 cells.
PMID- 10780453
TI - Search for a selenocysteine tRNA in Bacillus subtilis.
AB - Activity to convert serine to selenocysteine in B. subtilis was studied but no
activity was detected. In addition, although we tried to find its selenocysteine
tRNA (tRNA(SeCys)) gene from a total genome sequence (1) by the computer search
with FASTA against E. coli selC (2), no convincing candidate was found. These
results suggest that in B. subtilis, selenium-related system is considerably
different from known one like E. coli.
PMID- 10780454
TI - Relationship of the CCA sequence of tRNA with the early evolutional aspect of
aminoacyl-tRNA synthetases.
AB - The CCA sequence is common to the 3'-ends of all tRNAs. We investigated the
requirement of the CCA sequence in aminoacylation with the cognate aminoacyl-tRNA
synthetases (aaRSs) and several interesting conclusions could be drawn. In tRNAs
belonging to the class I aaRSs, decreased aminoacylation activities resulted from
the substitution of A76 with a pyrimidine, whereas in tRNAs belonging to the
class II aaRSs, decreased aminoacylation activities resulted from the
substitution with guanine. The results suggest that aminoacylation of proto-tRNA
might have started through the direct hydrophobic (or stacking) interaction
between the large, hydrophobic amino acid residue (now utilizing a class I aaRS)
of aminoacyl-AMP and the 3'-terminal adenine. The shorter distance between the
adenine and the 2'-OH position than the 3'-OH position, and the bulkiness and
hydrophobicity of amino acids may be important reasons why class I aaRSs select
the 2'-OH position in aminoacylation. Molecular mechanics-based conformation
modeling also indicated that the resulting positioning of the adenine and the
amino acid residue of 2'-aminoacyl-adenosine for large amino acid is in the
vicinity. In contrast, in the case of small amino acids (with class II aaRSs)
which would not be able to use the hydrophobic interaction, a protein enzyme
might have participated in the aminoacylation reaction from an early stage. The
active-site folds of aaRSs belonging to each class reflect the history of
evolution: typical nucleotide-binding fold (Rossman fold) in the case of class I
aaRSs, and primitive fold which is found also among the family of nonribosomal
peptide synthetases in the case of class II aaRSs.
PMID- 10780455
TI - In vivo selection of RNA-binding peptides from combinatorial libraries.
AB - We have used a two step procedure to identify peptides that bind strongly to the
Rev-response element (RRE) of HIV. In the first step, RRE-binding peptides were
screened from a combinatorial peptide library generated by "randomization" using
a small subset of the 20 amino acids. In the second step, one such RRE-binding
peptide, RSG-1, was "evolved" into an even stronger RRE-binding peptide using a
codon-based mutagenesis procedure. After 2 rounds of evolution, RSG-1.2 bound the
RRE with 7-fold higher affinity than wild-type Rev peptide.
PMID- 10780456
TI - Specific RNA protease inhibitors from in vitro selection.
AB - RNA aptamers that bind to and inhibit the proteolytic activity of subtilisin BPN'
are selected in vitro from pools of random RNA. The RNAs in vitro transcribed
from the isolated clones show highly specific inhibition toward the microbial
serine proteases. From the sequences of the isolated clones, a C/A-rich sequence
was obtained. The kinetic features of the common C/A-rich sequence will be
discussed.
PMID- 10780458
TI - Probing of the secondary structure of maxizymes.
AB - The protein encoded by chimeric BCR-ABL mRNA causes chronic myelogenous leukemia
(CML). We showed previously that a novel allosterically controllable ribozyme, of
the type known as a maxizyme, can cleave this mRNA, with high specificity and
high-level activity in vivo. In order to probe the putative conformational
changes, we used a weakly alkaline solution to hydrolyze differentially
phosphodiester bonds that were located in different environments. As indicated by
earlier data obtained in vivo, our results demonstrated that the active
conformation was achieved only in the presence of the junction within the
chimeric BCR-ABL mRNA.
PMID- 10780457
TI - Comparative study of two ribozymes and DNA-enzyme against the same RNA target.
AB - Two ribozymes, hammerhead ribozyme and hairpin ribozyme, and a DNA-enzyme were
designed to cleave a same RNA target, the same site of the rat complement
regulatory factor 512 antigen mRNA. The kinetic properties of these RNA-cleaving
enzymes were measured and compared under the same conditions, using multiple
turnover kinetics and competition kinetics. The catalytic efficiencies of these
enzymes, and also the order of these enzymes will be discussed.
PMID- 10780459
TI - Design and NMR analysis of HDV ribozymes for structural investigation.
AB - Three variants of minimized hepatitis delta virus (HDV) RNA ribozyme systems (Rz
1 to approximately Rz-3) (Fig. 1) were designed on the basis of the "pseudoknot"
structure model and synthesized. Rz-1 is a cis-acting ribozyme system (a cleaved
form, 56-mer) in which stem IV is deleted from the active domain of genomic HDV
RNA. Rz-1 was uniformly labeled with stable isotopes, 13C and 15N. The 2D-NOESY
and 2D-HSQC data for Rz-1 suggest that Rz-1 forms the pseudoknot structure and
G38 which is opposite to the cleavage site makes a base-pair. Rz-2 is a trans
acting ribozyme system which consists of three RNA oligomer strands (substrate: 8
mer, the cytidine residue at the cleavage site is replaced by 2'-O
methylcytidine; enzyme: 16-mer plus 35-mer). Rz-3 is a ribozyme in which the
three RNA strands of Rz-2 are connected. It turns out that Rz-3 forms an inactive
structure with low cleavage activity (k(obs) = 0.009) and final cleavage yield
(6%). Rz-3 has the highest cleavage activity at pH 5.5. The optimal activity at
acidic pH is similar to that of the wild type ribozyme. We also synthesized and
examined the activity and structure of Rz-4 (designed by Perrotta and Been) which
consists of two RNA strands (1).
PMID- 10780460
TI - Photodynamic antisense regulation using psoralen-conjugated oligo(nucleoside
phosphorothioate)s (I). Growth regulation of cervical carcinoma cells.
AB - To increase the antisense regulatory effect of oligo(nucleoside
phosphorothioate)s (S-Oligo), a photo-crosslinking reagent, 4, 5', 8
trimethylpsoralen, was used in this study. Psoralen-conjugated oligo(nucleoside
phosphorothioate) (Ps-S-Oligo) complementary to the human papillomavirus type 18
(HPV18) mRNA drastically inhibited the cellular proliferation of cervical cancer
cells only upon UVA-irradiation. In contrast, Ps-S-Oligos with mismatched
sequences and scrambled one showed lesser inhibitory effects than that with
matched one. These results suggest that psoralen-conjugated antisense S-Oligo has
significant potential to regulate gene expression upon UVA-irradiation.
PMID- 10780461
TI - Properties of circular dumbbell RNA/DNA chimeric oligonucleotides containing
antisense phosphodiester oligonucleotides.
AB - We have designed a new class of oligonucleotides, "dumbbell RNA/DNA chimeric
phosphodiesters", containing two alkyl loop structures with RNA/DNA base pairs
(sense (RNA) and antisense (DNA) in the double helical stem. The reaction of
nicked (NDRDON) and circular (CDRDON) dumbbell RNA/DNA chimeric oligonucleotides
with RNaseH gave the corresponding antisense phosphodiester oligonucleotide
together with the sense RNA cleavage products. The liberated antisense
phosphodiester oligodeoxynucleotide was bound to the target 35mer RNA, which gave
35mer RNA cleavage products by treatment with RNaseH. The circular dumbbell
RNA/DNA chimeric oligonucleotide showed more nuclease resistance than the linear
antisense phosphodiester oligodeoxynucleotide(anti-ODN) and the nicked dumbbell
RNA/DNA chimeric oligonucleotide.
PMID- 10780462
TI - Phosphorothioate G3T4G3 motifs inhibits the early stage of HIV-1 infection.
AB - It is well known that G-rich phosphorothioate oligonucleotides (G-rich PS) bind
to the V3 loop of HIV-1 gp120 and inhibit HIV-1 infection. In this study, we
investigated the inhibitory mechanism of a new type of G-rich PS (PS-G3T4G3) on
the replication cycle of HIV-1. PS-G3T4G3 inhibits both cell to cell and cell
free infections. Binding and entry assays revealed that the inhibitory step of PS
G3T4G3 occurs at the early stage of HIV-1 infection. V3 loop-specific mAb test
showed that PS-G3T4G3 binds to the V3 loop and prevents its interaction with
chemokine receptors. These results suggest that PS-G3T4G3 may be a novel
candidate for an HIV-1 inhibitor.
PMID- 10780463
TI - Synthesis and properties of oligodeoxynucleotides containing a C-2 polyamine
bearing deoxyguanosine residue as artificial ribonuclease.
AB - Oligodeoxynucleotides containing a 2-fluoro-2'-deoxyinosine residue substituting
normal 2'-deoxyguanosine residue were synthesized. Upon treating with ethanol
solution of polyamine, the fluorine atom in the oligomers were readily
substituted with the polyamine. The thermal stabilities of the duplexes consisted
of the polyamine-bearing oligomers and their cDNAs as well as their RNA cleaving
activity were investigated.
PMID- 10780464
TI - Improvement of efficiency of the Ce(IV)-induced DNA scission--relationship
between the kinetic parameters (k(cat) and Km) and the DNA structure.
AB - The Michaelis constant (Km) for double-stranded DNA, single-stranded DNA, and
dinucleotide hydrolysis by Ce(IV) ion are 4.4, 15, and more than 40 mM,
respectively. The order of the k(cat), however, is dinucleotide >>
oligonucleotides. Not only the improvement of k(cat) but also that of Km is
important for the design of an efficient artificial nuclease.
PMID- 10780465
TI - Development of a system to classify 3D structural character of RNA.
AB - We are developing a computational system to extract structural character of RNA.
We made a program that classifies conformers by recognizing the hydrogen bonding
patterns. The program was applied to a set of 279 conformers and they were
classified into about 40 groups. The system is expected to be useful for
searching structural motifs of RNA and classifying large number of generated
conformers in structural modeling process.
PMID- 10780466
TI - Imaging the RecA-DNA complex by atomic force microscopy.
AB - Atomic force microscopy (AFM) was applied to study the RecA protein and its
complexes with DNA in air and in aqueous solution. RecA and DNA were reacted
under several conditions, and deposited onto a mica substrate pre-treated in
various ways. We found that the structure of the RecA and RecA-DNA complexes,
especially the height of the molecules, was affected by the sample preparation
method such as gel filtration, and environment during imaging.
PMID- 10780467
TI - In vitro selection of deoxyribozymes with DNA capping activity.
AB - In vitro selection was used to isolate a series of deoxyribozymes from a pool of
random-sequence DNAs that catalyze an ATP-dependent self-capping reaction. Each
deoxyribozyme catalyzes the transfer of the nucleoside and alpha-phosphate
moieties of ATP to the phosphate group located at its 5' terminus, thereby
creating a 5',5'-pyrophosphate cap. This same pyrophosphate cap structure is
formed by T4 DNA ligase during the classical process of DNA ligation. These DNA
capping enzymes representative of a collection of self-processing deoxyribozymes
that can be used for the directed modification of DNA.
PMID- 10780468
TI - Rapid and specific detection of RNA base sequence using fluorescence
polarization.
AB - Rapid and specific determination of the RNA gene of hepatitis C virus (HCV),
which had been multiplied by NASBA, was performed using a fluorescence
polarization assay. The polarization of the probe DNA in the presence of HCV
positive sample, amplified by NASBA, was obviously different from those in the
presence of negative control samples. The total time for the gene amplification
and detection was about 90 min, while the polarization detection was completed
within 10 min. The slight increase of polarization was also confirmed with the
hybridization between probe oligo-DNA 25-mers and the synthesized complementary
oligo-RNA 25-mers. The polarization of positive and negative samples showed
excellent agreement with the results obtained from electrophoresis and dot-blot
hybridization.
PMID- 10780469
TI - Efficiency enhancement of long-range energy transfer by sequential multistep FRET
using fluorescence labeled DNA.
AB - The efficiency of long-range (ca. 80 A) fluorescence energy transfer was enhanced
about 1.5 times by a third chromophore located midway between two chromophores. A
third chromophore should act like a relay station in sequential multistep energy
transfer.
PMID- 10780470
TI - Single large DNA molecule analysis using fluorescence microscopy.
AB - A large DNA analysis method which enable to obtain spatial information of
positions of specific sequences along DNA molecule has been developed. Making use
of the phenomenon that large DNA molecule is elongated stably under alternative
current field in a concentrated linear polymer solution, direct observation of
elongated individual lambda DNA molecules with fluorescence probes was carried
out using fluorescence microscopy. Then, the spatial positions of the
fluorescence spot of the probe on the DNA molecule were determined by image
analysis.
PMID- 10780472
TI - Synthesis and DNA-binding of acridine-netropsin hybrid molecules.
AB - We have designed and synthesized acridine-netropsin hybrid molecules.
Spectroscopic (absorption, CD, flow dichroism and fluorescence) measurements
reveal that hybrid molecules interact with DNA by both intercalation and minor
groove binding and shows enhanced preference for AT-rich sites.
PMID- 10780471
TI - Direct measurement of DNA by means of AFM.
AB - We have demonstrated that the electrostatic stretch-and-positioning method is
useful for the analysis of a long DNA molecule by means of atomic force
microscopy (AFM). DNA molecules were stretched parallel to the field line, and
immobilized onto the aluminum electrodes patterned on a glass plate. Through AFM
observation, we confirmed the immobilization of individual DNA molecules, not
aggregate.
PMID- 10780473
TI - Synthesis of pyrrole-imidazole-duocarmycin polyamide and its sequence selective
DNA alkylation.
AB - The new solid phase synthesis of sequence-specific DNA alkylating polyamides
containing segment A of Du86 (Duo), N-methylimidazole (Im) and N-methylpyrrole
(Py) amino acids is described. New monomer building block N-carboxylmethyl Py
(Pyc) was synthesized from 2-methylpyrrolecarboxylate by eight steps. After
normal coupling of FMOC-protected-Im and -Py monomer, the deprotection of silyl
group generates free carboxylic acid. Introduction of various types of functional
groups on solid support will be presented.
PMID- 10780474
TI - Novel DNA-binding ligands with sequence selectivity based on hydrophobic
structure.
AB - We have developed diamino-bistetrahydrofuran compounds (diamino-bisTHF) as new
DNA binding molecules. Diamino-bisTHF (3:RR8) stabilized GC-rich duplex DNA with
sequence specificity. DNA binding affinity increased as the alkyl chain was
lengthened, indicating that the hydrophobic interaction is essential for DNA
binding. It was also found that DNA binding affinity of the ligands depends on
the stereochemistry of the amino group. In thermodynamic evaluation, diamino
bisTHF (3:RR8) showed a high affinity to the 12 bp duplex at a molar ratio of
1:1.
PMID- 10780476
TI - Novel GG-specific DNA photocleavers: p-cyanobenzamide-terthiazole derivatives.
AB - We have synthesized novel GG-selective photocleavers containing the p
cyanobenzamide group which exerts DNA cleaving activity via a thiazole based
multistep electron transfer.
PMID- 10780475
TI - Amplification of bleomycin-induced DNA cleavage by pyrrole triamide.
AB - We investigated the amplification of bleomycin-induced DNA cleavage by synthetic
pyrrole triamide (PyPyPy) using 32P-labeled DNA fragments obtained from human
genes. Peplomycin, a kind of bleomycins, plus Fe(II) caused DNA cleavage at the
5'-GC-3' and 5'-GT-3' sequences (damaged bases are underlined). The addition of
PyPyPy enhanced the cleavage at cytosine and thymine residues 3' to consecutive
guanines, particularly at the 5'-GGGGC-3' and 5'-GGGGT-3' sequences. These
results suggest that PyPyPy binds to DNA to induce its conformational change,
resulting in alteration of the site specificity and amplification of DNA
cleavage. The present study on amplifiers of antitumor drugs would show a novel
approach to the establishment of more effective chemotherapy.
PMID- 10780477
TI - Mechanism of ribosome RNA apurinic site specific lyase.
AB - A new enzyme, which we named ribosome RNA apurinic site specific lyase (RALyase),
has been characterized. The enzyme specifically cleaves a phosphodiester bond at
the apurinic site in the sarcin/ricin domain of 28S rRNA in ribosomes. The cut
ends of wheat 28S rRNA were determined as 5'---GUACG-alpha-hydroxy-alpha, beta
unsaturated aldehyde and pGAGGA---3' for the 3' fragment, demonstrating that the
enzyme catalyzes the beta-elimination reaction.
PMID- 10780478
TI - Drosophila tRNAs hyperprocessed in vitro by ribonuclease P.
AB - In transposon copia-related retrovirus-like particles of Drosophila, a 5' half
fragment produced by the cleavage of mature initiator methionine tRNA is used as
the primer for minus-strand reverse transcription. This cleavage is called
hyperprocessing. We have previously reported that the catalytic RNA subunit of
RNase P catalyzes this hyperprocessing in vitro and that this cleavage is
dependent on the occurrence of an altered conformation of the tRNA substrate.
Here, we found that other mature tRNAs of Drosophila were also hyperprocessed by
M1 RNA in vitro and that some of such tRNAs were probably alanine and histidine
tRNAs. Here we report these two tRNAs can also adopt their alternative
conformations very similar to that of initiator methionine tRNA.
PMID- 10780479
TI - Molecular cloning and characterization of a nuclear gene encoding a putative
subunit of tRNA splicing endonuclease from Arabidopsis thaliana.
AB - tRNA splicing endonuclease is required to produce mature tRNAs from intron
containing tRNA precursors. To characterize the structural features of plant
endonuclease, we have isolated a cDNA and a corresponding genomic DNA clone from
libraries of Arabidopsis thaliana which encode a putative subunit of the
endonuclease. The gene product has an apparent mass of 27 kDa and contains a
homologous domain of approximately 130 amino acids at the C-terminal region
commonly found in other eucaryal and archaeal counterparts. Southern
hybridization analysis of Arabidopsis genomic DNA utilizing the cDNA clone as
probe indicates the presence of at least two related genes.
PMID- 10780480
TI - Functional analysis of the transcriptional coactivators p300 and CBP using
ribozyme.
AB - p300 and CERB binding protein (CBP) are transcriptional coactivator which
participate many signal transduction pathways via interaction with DNA binding
proteins. In this study, we investigated functions of p300 and CBP during the
retinoic acid (RA) induced F9 cell differentiation using hammerhead ribozymes. In
wild type F9 cells, induction of c-jun gene was observed at 18 h after treatment
with RA. Interestingly, RA-dependent expression of c-jun gene was not induced in
cells expressing the p300-directed ribozyme. By contrast, the CBP-directed
ribozyme did not affect expression of the c-jun gene. These results suggest that
p300 is critical for the induction of c-jun gene during RA-induced
differentiation.
PMID- 10780481
TI - DNA structures recognized by the human UV-DDB protein.
AB - DNA recognition by the human UV-damaged DNA-binding (UV-DDB) protein was
characterized. By circular permutation analyses, DNA duplexes containing the (6
4) photoproduct and the abasic site analog were found to be bent at angles of 54
degrees and 57 degrees, respectively, when they formed a complex with this
protein. Although kinked NMR structures have been reported, fluorescence
resonance energy transfer experiments revealed that these duplexes had no
intrinsic bend. These results suggest that the UV-DDB protein binds DNA that can
be bent easily at the above angle.
PMID- 10780482
TI - Crystal structures of the 64M-2 and 64M-3 antibody Fabs complexed with DNA (6-4)
photoproducts.
AB - Crystal structures of the 64M-2 antibody Fab fragment complexed with DNA
photoproducts of dT(6-4)T and dTT(6-4)TT, and of the 64M-3 Fab fragment complexed
with dT(6-4)T were determined. The 5'-thymine base of the bound dT(6-4)T ligand
is in a half-chair conformation, and its base plane is nearly perpendicular to
the planar 3'-pyrimidone base. The 64M-2 and 64M-3 Fabs have a common structure
suitable for accommodating the dT(6-4)T ligand. In each of the antigen binding
sites of the 64M-2 and 64M-3 Fabs, basic residues of His 35H and Arg 95H are
located at the bottom of the binding pocket, and are hydrogen-bonded to the base
moieties of dT(6-4)T. Two water molecules are involved in the interactions that
intervene between the base moieties and the binding site. Aromatic residues of
Trp 33H and Tyr 100iH form a side-wall of the pocket and are in van der Waals
interactions with the base moieties. The Trp 33H side-chain is placed in parallel
to the 3'-pyrimidone base, and the Tyr 100iH side-chain is nearly perpendicular
to the 5'-thymine base. His 27dL, Tyr 32L, Leu 93L, and Ser 58H forming another
side-wall are located in the vicinity of the sugar-phosphate backbone. In the 64M
2 Fab complex with dTT(6-4)TT, 5'- and 3'-side phosphate groups are also involved
in interaction with Fab residues.
PMID- 10780483
TI - Structural study of an RNA aptamer for a Tat protein complexed with ligands.
AB - An RNA aptamer for an HIV Tat protein has been isolated by the in vitro SELEX
method. The RNA aptamer binds to the Tat protein 50-100 times more strongly than
native TAR RNA does. Here, we have investigated the structure of the RNA aptamer
complexed with ligands, partial peptide fragments of the Tat protein or
argininamide, by multidimensional 1H/13C/15N NMR. It is strongly suggested that
two U:A:U base triples are formed in the RNA aptamer upon binding of ligands.
Specific hydrogen bonds between arginine side chains of ligands and guanine bases
located adjacent to the base triples are identified. On the basis of many
intramolecular and intermolecular NOEs, a structural model of the complex has
been constructed.
PMID- 10780484
TI - Design of artificial pepetides that recognize the HIV RRE IIB RNA.
AB - Peptide nucleic acid (PNA) conjugated peptides, derived from HIV-1 Rev, were
designed and synthesized in order to construct molecules that recognize HIV RRE
IIB RNA. The competitive binding analyses using fluorescent Rev peptide revealed
that the PNA unit on the peptide affected the RNA binding.
PMID- 10780485
TI - The harpin ribozyme: the roles of ions in RNA cleavage.
AB - The cleavage reaction of the hairpin ribozyme is facilitated by divalent metal
ions, such as Mg2+, or by non-metallic polycations, such as the polyamine
spermine. We show substantial enhancement of cleavage with combinations of
metallic and non-metallic ions. In addition we elucidate the locations of some
ion binding sites by Fenton chemistry.
PMID- 10780486
TI - Allosteric ribozymes sensitive to the second messengers cAMP and cGMP.
AB - We have engineered allosteric ribozymes by combining modular rational design with
combinatorial strategies. This new procedure was used to create allosteric
ribozymes that are activated by specific nucleoside 3',5'-cyclic monophosphates
(cNMPs). A random-sequence domain was attached to stem II of hammerhead ribozymes
via a communication module that serves as an interface between ribozyme and the
effector binding site. Subjecting this initial random pool to in vitro selection
methods produced populations that respond, or cleave, only in the presence of
specific effector molecules. From generation 18, 20 and 23, cGMP, cCMP and cAMP
specific responsive ribozymes, respectively, were isolated and characterized.
These methods show great promise for engineering allosteric ribozymes and for
creating new ligand-specific aptamers.
PMID- 10780487
TI - Extended in vitro selection for synthesis of novel catalytic oligonucleotide
derivatives.
AB - A new catalyst, which is composed of nonnatural ribonucleotides, was synthesized
by the in vitro selection method. Nonnatural RNAs that bound to N
methylmesoporphyrin were selected from a pool of random-sequence RNAs containing
2'-amino cytidine 5'-triphosphate (2'-amino CTP) instead of CTP. The selected
RNAs not only bound to the ligand, N-methylmesoporphyrin (NMM), but also
catalyzed metalation reaction of porphyrin.
PMID- 10780488
TI - Induction of ribozyme activity by anti-ribozyme oligonucleotides.
AB - A new type of hammerhead ribozyme, with cleavage activity enhanced by
oligonucleotides, was constructed. Stem II of the ribozyme was substituted with a
non complementary loop (loop II). The modified ribozyme exhibited negligible
cleavage of a target RNA; however, it was converted to an active molecule in the
presence of oligonucleotides which were complementary to loop II. The
oligonucleotide compensated for the disabled stem II by binding with the
ribozyme. The induction of the cleavage activity was sequence-specific and the
oligonucleotides containing a purine base as the 3'-dangling end were able to
induce the cleavage activity of the ribozyme most efficiently. A photo
crosslinking experiment proved that a pseudo-half-knot structure was formed in
the active molecule. The cleavage of two kinds of substrate RNAs with different
sequences was controlled by the corresponding ribozymes activated by specific
oligonucleotides.
PMID- 10780489
TI - Development of a short Ca2+-dependent deoxyribozyme with RNA cleavage activity.
AB - We developed a short Ca2+-dependent deoxyribozyme with 11 mer catalytic loop
domain (dGGCTACAACGA) that catalyzed site-specific RNA cleavage reaction between
rA and rU. The second-order rate constant of this short deoxyribozyme is 1.7 x
10(7) M(-1) min(-1) at 37 degrees C, and this value is very similar to that of
the deoxyribozyme (dGGCTAGCTACAACGA) in the presence of Ca2+.
PMID- 10780490
TI - Action of metal ions directly involved in the cleavage reaction of hammerhead
ribozymes.
AB - Recently, hammerhead ribozyme-mediated cleavage was analyzed as a function of the
concentration of La3+ ions in the presence of a fixed concentration of Mg2+ ions
so that the role could be monitored of metal ions that are directly involved in
the cleavage reaction. The resultant bell-shaped curve for activation of cleavage
was used to support the proposed double-metal-ion mechanism of catalysis.
However, other studies demonstrated that binding of a metal ion to the pro-Rp
oxygen (P9 oxygen) of the phosphate moiety of nucleotide A9 and N7 of nucleotide
G10.1 is critical for efficient catalysis. In order to clarify the effect of this
metal ion, we chemically synthesized hammerhead ribozyme (7-deaza-R34) that
included a minimal modification, namely, an N7-deazaguanine residue in place of
G10.1.
PMID- 10780491
TI - Selection of intracellularly active ribozymes in mammalian cells.
AB - Ribozymes are expected to be useful as antiviral agents and powerful tools of
functional analysis of unknown gene products in vivo. For use of ribozymes in
vivo, they must be fully functional in the intracellular environment. Not all
ribozymes selected in vitro would be expected to work in vivo, whereas ribozymes
selected in the intracellular environment should retain their function in vivo.
With the eventual aim of using ribozymes as antiviral agents or biological tools
in mammalian cells, we then devised a novel selection system in mammalian cells
of active ribozymes by targeting at a gene for the cyclin dependent kinase
inhibitor (CDKI), p16INK4a. In this system, we found that p16INK4a-knockdown
cells became malignant and they formed foci. In the mammalian system, we
confirmed that the selected cells harbored the active ribozyme, indicating that
our positive selection systems in vivo were operational.
PMID- 10780492
TI - Importance of short pseudoknot base pairs between two single-stranded regions of
HDV ribozyme.
AB - Human hepatitis delta virus (HDV) ribozyme can catalyze self-cleavage reaction in
the presence of Mg2+ ions, yielding products with 2',3'-cyclic phosphate and 5'
OH termini as do hammerhead and hairpin ribozymes. Recently, the tertiary
structure of 3'-cleaved product of genomic HDV ribozyme was solved by X-ray
crystallographic analysis. In this structure three single-stranded regions (SSrA,
-B and -C) interacts intricately with hydrogen bonds between bases, phosphate
oxygens and 2'-OHs to form nested double pseudoknot structure. Especially two
Watson-Crick base pairs, 726G-710C and 727G-709C, between SSrA and SSrC, seems to
be important for compact folding. To characterize the necessity of the two base
pairs, we performed in vitro selection of active ribozymes using random RNA pool
which mutated at 709, 710, 726 and 727. The result indicates that basically one G
C base pair is necessary for the activity.
PMID- 10780493
TI - Measurement of the rate of RNA hydrolysis in aqueous solution at elevated
temperatures using a new monitoring method for hydrothermal reactions.
AB - A new monitoring method for hydrothermal reactions, which is capable to monitor
reactions in aqueous solution at 100-300 degrees C in 0.003-140 s, has been
applied for the measurements of the rate of hydrolysis of oligonucleotides
containing ribonucleic phosphodiester linkage. The hydrolyses of several types of
oligonucleotides were monitored using the method at over 100 degrees C.
PMID- 10780494
TI - Cellular repair mechanism of 5-formyluracil.
AB - 5-Formyluracil (fU) is an oxidative DNA base damage. This damage has been
suggested to be mutagenic and but enzymatic repair of the damage is little known.
In this study, repair enzymes that recognize fU have been studied. Kinetic
analysis of the repair activity of E. coli 3-methyladenine DNA glycosylase II
(AlkA) showed that fU was removed by AlkA with the efficiency comparable to 7
methylguanine. We also examined the participation of the methyl-directed mismatch
repair system. The affinity of MutS to the fU:G mispair was essentially similar
to that of the T:G mispair that was most efficiently recognized by the MutSLH
system. These results suggest two distinct repair pathways of fU in E. coli.
PMID- 10780495
TI - Nuclear localization of transcription factor Sp1.
AB - Transcription factor Sp1 is importantly related to expression of many cellular
genes. In order to identify the nuclear localization signal of Sp1, various
truncated regions of Sp1 were fused to green fluorescent protein (GFP) and were
expressed in HeLa cell. The C-terminal region are required to localize Sp1 in the
nucleus of HeLa cell.
PMID- 10780496
TI - Development of an HIV-1-dependent expression vector with the Cre/loxP system.
AB - Previously, we used the human methionine tRNA promoter as an expression cassette
for hammerhead ribozymes. The tRNA promoter driven ribozyme was targeted against
the LTR portion of the HIV-1 NL4-3 strain. We constructed VSV-G-pseudotyped MuLV
based vectors expressing the ribozyme. The ribozyme expressing retrovirus vector
strongly suppressed gag p24 antigen production in freshly HIV-1 infected MT-4
cells. In this study, the potential of such a molecular genetic intervention was
examined by using the Cre-loxP recombination system. Site-specific excision of
HIV-1 was achieved by using this model system with an acute infection. These
studies represent one step toward the development of a novel antiviral strategy
for the treatment of AIDS.
PMID- 10780497
TI - Inter-species consistency in the behavioural pharmacology of nicotine dependence.
AB - Studies on the dependence-related behavioural effects of nicotine in animals and
humans have been compared to assess the extent of inter-species consistency in
relation to the face, construct and predictive validity of the animal models. The
major areas covered in this selective review are neuroadaptations occurring as a
consequence of repeated exposures to nicotine (i.e. tolerance, sensitization and
withdrawal) and the stimulus properties of nicotine (positively reinforcing,
discriminative stimulus and aversive stimulus effects). Most of these phenomena
were demonstrated first in animal subjects, often many years before comparable
data for humans became available, although this was not invariably the case. It
is argued that the overall pattern of results for the neuroadaptations is very
similar across species. More specifically, it is proposed that repeated exposure
to nicotine produces a change from a relatively aversive initial overall profile
to one in which tolerance has developed to the aversive effects and the positive
effects on mood have been enhanced or sensitized; at the same time a withdrawal
syndrome develops that can now be assessed by a variety of measures in animal and
human subjects. With regard to stimulus properties, the nicotine discriminative
stimulus in animal and human subjects shows a particularly close correspondence,
which may reflect the functional equivalence of the procedures in the different
species. The self-administration of pure nicotine, as contrasted with tobacco
smoke, has been firmly established in animal subjects for some time but there are
only a small number of strictly comparable studies in humans. Both differences
and similarities in findings across species may be seen; however, care must be
taken to identify the possible confounding influence of procedural variation
between species, rather than the species per se, as the determining factor.
Overall, the animal studies in this area have shown remarkably good predictive
validity, coupled with rather more variable levels of face and construct
validity.
PMID- 10780498
TI - Implications for tobacco regulation and public health. Commentary on Stolerman's
Inter-species consistency in the behavioural pharmacology of nicotine dependence.
PMID- 10780499
TI - An anthology of behavioural pharmacology. Commentary on Stolerman's Inter-species
consistency in the behavioural pharmacology of nicotine dependence.
PMID- 10780500
TI - Molecular mechanisms of the positive reinforcing effect of nicotine.
AB - Animal models of nicotine dependence are fundamental experimental tools for the
understanding of the neurobiological and molecular processes underlying smoking
behaviour. Substance use is controlled by four main processes: positive
reinforcing effects, aversive effects, discriminative effects and stimulus
conditioned effects of the drug. In this article, the molecular and neural bases
of the positive reinforcing effects of nicotine are summarized, focusing on data
obtained in experiments including unambiguous and objective measurements of the
reinforcing properties of nicotine. Operant behaviour paradigms, in particular
intravenous nicotine self-administration, offer such a possibility within a solid
theoretical framework. Nicotine self-administration produces changes in the
mesocorticolimbic DA system, a key component of the reward system, as do other
addictive drugs. The role of the mesocorticolimbic DA system as the main
substrate of the reinforcing properties of nicotine is supported by converging
experiments, including the evidence that nicotine self-administration is
attenuated in mutant mice lacking the beta2 subunit of neural acetylcholine
nicotinic receptor. The long-term adaptive molecular changes in the target
neurons of the terminal fields of the mesocorticolimbic DA system, including
transcriptional regulation mediated by c-fos family gene products on other genes,
suggest that the mesolimbic DA projection to the nucleus accumbens is mainly
involved in the stimulus-reward learning process. These data represent an initial
set of information only, which may help to develop a more complete and reliable
model of the molecular dynamics underlying the reinforcing effects of nicotine.
PMID- 10780501
TI - Baseline-dependency of nicotine effects: a review.
AB - 'Rate-dependency', a founding observation of behavioral pharmacology, generally
indicates that effects of drugs will be inversely related to the rate of operant
responding under control conditions (i.e. decrease in high-rate behaviors and
increase in low-rate behaviors). 'Baseline-dependency' encompasses rate
dependency and extends this notion to other drug effects, including those
assessed by means other than 'rate' (such as subjective mood self-reports).
Although little human research has specifically investigated the effects of
nicotine as a function of baseline level of responding, a number of studies
suggest baseline-dependent differences in the influence of nicotine on behavioral
and cognitive task performance and on subjective mood responses. Results of many
animal studies also are very consistent with these observations. Baseline
dependency, perhaps, is most clearly demonstrated in comparisons between groups
selected on the basis of specific characteristics (e.g. high vs low 'trait
hostility'), or within subjects as a result of acute environmental manipulations
(e.g. high vs low 'stress' task). Moreover, baseline-dependency of the effects of
nicotine may have broader applicability in explaining individual differences in
vulnerability to nicotine dependence, particularly among those with psychiatric
disorders (e.g. depression). While individual differences in responses to
nicotine may be due to differences in pharmacological sensitivity to nicotine, as
commonly assumed, they also may be due partly to individual and situationally
determined differences in baseline level of responding on the measure of
interest. Consideration of the conditions under which baseline-dependent effects
of nicotine are observed may clarify both individual difference and situational
influences on responses to nicotine.
PMID- 10780502
TI - Do the origins of behavior matter? Commentary on Perkins' Baseline-dependency of
nicotine effects: a review.
PMID- 10780503
TI - The Questionnaire of Smoking Urges is sensitive to abstinence and exposure to
smoking-related cues.
AB - The Questionnaire of Smoking Urges (QSU) was designed to measure cravings
elicited by abstinence from cigarette smoking. In the present study, the
sensitivity of the QSU both to brief periods of abstinence and to exposure to
smoking-related cues was investigated. A progressive ratio (PR) operant procedure
was also employed, in which behaviour was maintained either by primary
reinforcement (puffs on a cigarette) or by secondary reinforcement (tokens
exchanged later for puffs on a cigarette) in separate experiments. Dependent
smokers, who were not abstinent or who were abstinent for either 2 or 4 h, were
tested in both a cue-rich and a no-cue environment. The results indicated that
the QSU was sensitive both to brief periods of abstinence and to exposure to
smoking-related cues, but the effect of smoking-related cues on QSU scores was
maximal in non-abstinent smokers. In contrast, neither abstinence nor exposure to
smoking-related cues significantly influenced the number of reinforcers earned,
or the number of responses made, in either PR task. However, there was a
significant interaction between gender and degree of abstinence on PR performance
under primary reinforcement, and correlations between PR and QSU measures that
were dependent on a complex interaction between the presence/absence of smoking
related cues and the type of reinforcer used. These results suggest that the QSU
is sensitive to subtle influences on subjective urges to smoke in dependent
smokers and, although PR measures are relatively insensitive to these influences,
there is some evidence that PR performance is related to subjective measures of
the urge to smoke.
PMID- 10780504
TI - A comparison of measures of relative reinforcing efficacy and behavioral
economics: cigarettes and money in smokers.
AB - In this experiment, we compared behavioral economic measures and measures of the
relative reinforcing efficacy of cigarettes and money between-participants. The
experiment proceeded in two phases. In the first phase, money and cigarettes were
available on separate progressive ratio (PR) schedules when they were solely
available. The response requirement for the PR schedule increased across
sessions, rather than within a session. In the second phase, money and cigarettes
were made concurrently available at some of the response requirements employed
during the PR schedule. Measures of (1) PR breakpoint, (2) peak response rate,
(3) preference, (4) elasticity and (5) Pmax (the price at which the greatest
amount of responding occurs) were compared within participant. Across the PR- and
concurrent-schedule conditions, the three measures of reinforcing efficacy
(breakpoint, response rate and preference) yielded an inconsistent assessment of
the relative reinforcing efficacy of money and cigarettes. The reinforcer that
resulted in greater peak response rates varied across subjects, while PR
breakpoint was higher for cigarettes in all participants. Further, in concurrent
schedules, preferences for cigarettes or money reversed across the response
requirements. Behavioral economic analyses suggest that Pmax and elasticity are
related to PR breakpoint, and that preference can be predicted from a comparison
of the demand curves under single-schedule conditions. Implications for the
concept of reinforcing efficacy are discussed.
PMID- 10780505
TI - Daily uplifts, hassles, stresses and cognitive failures: in cigarette smokers,
abstaining smokers, and non-smokers.
AB - Cigarette smokers (n = 25), temporarily abstaining smokers (n = 25) and non
smokers (n = 25), self-rated their feelings of stress, arousal and pleasure,
every 3 h over a normal day. Then, later in the evening, they rated the hassles,
uplifts, stresses and cognitive failures they had experienced during the day. The
abstaining smokers reported significantly worse psychological states on every
assessment measure, in comparison with both non-smokers and non-deprived smokers.
Abstinence thus led to greater stress, lower arousal, less pleasure, more
cognitive failures, more hassles and less uplifts. The non-deprived smokers did
not differ from the non-smokers on any dependent variable. These findings support
the Deprivation Reversal Model, which states that the apparent benefits of
smoking only represent the reversal of unpleasant abstinence effects. These data
provide no evidence to support the Nicotine Resource Model, which suggests that
tobacco smoking can relieve stress and improve cognitive functions. The
repetitive use of nicotine by cigarette smokers does not seem to generate any
real psychobiological gains or advantages. Instead, dependent smokers need
regular hits of nicotine just to remain feeling normal.
PMID- 10780506
TI - Asymmetric generalization between the discriminative stimulus effects of nicotine
and cocaine.
AB - The discriminative stimulus effects of nicotine and cocaine were studied, alone
and in combination, in rats. Two sets of rats were trained to press one lever
when injected intraperitoneally (i.p.) with either nicotine (0.1 mg/kg = 0.6
micromol/kg, Set 1) or cocaine (8.9 mg/kg base = 29.4 micromol/kg, Set 2), and
another lever when injected with saline. Rats learned to discriminate drug from
saline, and maintained discriminative control throughout the study (at > 85% drug
appropriate responding). In accordance with most previous findings, cocaine only
partially substituted for nicotine (maximum = 41% nicotine-lever responding). The
nicotinic agonist, nornicotine, produced dose-related, near-full substitution for
nicotine (maximum = 76% nicotine-lever responding), whereas the peripherally
acting nicotinic agonist, methylcarbamylcholine, did not substitute for nicotine.
The muscarinic receptor agonist pilocarpine also failed to substitute for
nicotine. However, in the cocaine-trained rats, nicotine substituted fully for
cocaine in a dose-dependent manner, demonstrating that cross-generalization
between the two drugs is not symmetrical. Finally, administration of each drug as
a pre-treatment to the other yielded inconsistent increases in each drug's
discriminative stimulus effects. The results are congruent with the view that the
discriminative stimulus effects of nicotine and cocaine share common features,
but the asymmetric pattern of cross-generalization and the interactions revealed
in the combination tests also suggest that there are important differences
between them.
PMID- 10780507
TI - Influencing the specificity of drug mixture discriminations by varying the
training procedure.
AB - Studies of the discriminative stimulus effects of drug mixtures provide an
approach to polydrug abuse and to studies on single drugs with multiple effects.
The experiments described here investigated whether the use of the AND-OR
procedure increases the specificity of drug mixture discriminations. Rats were
trained to discriminate a mixture of nicotine (0.4 mg/ kg) plus midazolam (0.2
mg/kg) from saline (AND-discrimination, n = 10) or to discriminate the same
mixture from its component drugs alone (AND-OR discrimination, n = 10). The
studies used two-lever operant procedures with a tandem variable interval 1 min
fixed ratio 10 (FR 10) schedule of food reinforcement. Under AND-discrimination
conditions, there was partial generalization to amphetamine and pentobarbitone
when each drug was administered singly. With the AND-OR-discrimination, there was
no generalization to amphetamine and partial generalization to pentobarbitone. In
'single substitution' tests, pentobarbitone or amphetamine was co-administered
with the training doses of nicotine and midazolam, respectively; there was full
generalization in the AND-discrimination and no generalization under AND-OR
conditions. In 'dual substitution' tests, mixtures of amphetamine plus
pentobarbitone produced full generalization under AND-discrimination conditions,
and partial generalization in the AND-OR procedure. Wherever comparisons were
made, generalization was less under AND-OR- than under the AND-discrimination
procedure, confirming that the AND-OR procedure can increase the specificity of
discriminations based on drug mixtures. The similarity with findings reported
previously for training with mixtures of amphetamine plus pentobarbitone suggests
that this may reflect a general principle rather than a phenomenon restricted to
particular training drugs.
PMID- 10780508
TI - The effect of repeated nicotine administration on the performance of drug-naive
rats in a five-choice serial reaction time task.
AB - Nicotine improves cognitive performance both in animals and in humans,
particularly in tests involving attentional processes. The five-choice serial
reaction time task (5-CSRTT) is widely used as a model of attentional performance
in rats, and previous studies have demonstrated effects of nicotine in this task
on measures such as improved reaction time. Using a modified version of this task
(in which rats were required to respond to the disappearance of one of five
stimulus lights), we evaluated the effects of repeated nicotine administration
(0.3 mg/kg, intraperitoneally, on three occasions over 7 days) in drug-naive
rats. After the first administration, nicotine increased accuracy and reduced
inappropriate responding (anticipatory responses and responses during time-out)
compared to performance following vehicle administration on the preceding day.
However, with repeated administration the improvement in accuracy disappeared,
and other effects became apparent. Thus, after the third administration the main
effects of nicotine were to increase inappropriate responding and to reduce
reaction times. A fourth administration 1-2 weeks later produced similar results
to the third administration, suggesting that the effects of nicotine were now
constant. Despite the general increase in inappropriate responding, there was no
impairment in accuracy. In contrast to the response to repeated nicotine, the
performance of the rats on the 3 vehicle days remained constant. These data
demonstrate that the administration of nicotine to drug-naive subjects improves
performance in the 5-CSRTT but that with repeated administration this effect
disappears and is replaced by a profile in which inappropriate and impulsive
responding predominate.
PMID- 10780509
TI - AR-R17779, and alpha7 nicotinic agonist, improves learning and memory in rats.
AB - Nicotinic acetylcholine systems have been found to be important for learning and
memory function. The prototypic nicotinic agonist nicotine has been shown in a
variety of studies to improve aspects of cognitive function. The specific
involvement of nicotinic receptor subtypes is now being investigated. The
involvement of alpha7 nicotinic receptors was assessed in this project using a
novel alpha7 nicotinic agonist, AR-R 17779. Repeated doses (subcutaneous
injection 20 min before testing) of the racemic mixture AR-R 13489 and its active
isomer AR-R 17779 were assessed in adult female Sprague-Dawley rats using the
eight-arm radial maze. AR-R 13489 (2 mg/kg) caused a significant improvement of
long-term win-shift acquisition after 3 weeks of training (n = 10 per group). The
same dose of AR-R 17779 also caused a significant improvement in repeated
acquisition within each daily session in the radial-arm maze. In another study,
the active isomer AR-R 17779 significantly improved radial-arm maze working
memory function in rats with lesions to the septohippocampal projection. Fimbria
fornix lesions significantly impaired working memory performance and AR-R 17779
significantly reversed that impairment. These studies showed that alpha7
nicotinic agonist treatment improved learning in two radial-arm maze tasks and
reversed working memory impairment caused by fimbria-fornix sections, providing
evidence for alpha7 involvement in learning and memory, and the potential
therapeutic use of AR-R 17779.
PMID- 10780510
TI - Differential improvement in memory-related task performance with nicotine by aged
male and female rhesus monkeys.
AB - Central nicotinc acetylcholine receptors have been targeted for the development
of novel treatments for memory deficits in Alzheimer's disease (AD) and other
neurodegenerative disorders. Nicotine itself has been shown to improve memory
related task performance in aged animals and in AD patients. Administration of
nicotinic receptor agonists to laboratory animals, and the effects of cigarette
smoking in humans attributed to nicotine, have in many instances been shown to
exert sexually dimorphic actions. Low doses (2.5-20 microg/kg, intramuscularly)
of nicotine have been shown to improve the performance of an automated delayed
matching-to-sample (DMTS) task in aged rhesus monkeys. The purpose of this study
was to determine whether aged females receive the same level of benefit to the
positive mnemonic action of nicotine as do males. In this study six male (21.7+/
1.2 years) and seven female (22.5+/-0.9 years) rhesus monkeys each received an
ascending series of four doses of nicotine over 5 weeks. Most control parameters
were similar between the two sexes, although task latencies were longer and more
variable in the female subjects. The males maintained a significant improvement
in task performance over the entire nicotine dose range. This level of
improvement extended to 24 h after nicotine administration. Task accuracy by
females appeared to improve only after they received the two higher doses of
nicotine, and their responses exhibited considerable variability over the entire
dose range. However, in calculating an individualized 'Best Dose', males and
females exhibited a similar level of task improvement (15-30% above baseline).
Therefore, aged female subjects may require a greater level of individualized
treatment and perhaps higher doses of nicotinic agonists to achieve the maximal
mnemonic benefit.
PMID- 10780511
TI - Time-course of changes in the social interaction test of anxiety following acute
and chronic administration of nicotine.
AB - The purpose of these experiments was to explore the hypothesis that the effects
of nicotine on anxiety depend on the time since administration and the duration
of treatment. In the social interaction test of anxiety, acute nicotine
administration (0.1 mg/kg, subcutaneously) decreased social interaction when rats
were tested 5 min after injection, but increased it when they were tested 30 min
after injection. Social interaction was also decreased 1 h post-injection, but
levels returned to baseline between 3 and 30 h. As these changes were independent
of any changes in locomotor activity, nicotine seemed to be having both
anxiogenic and anxiolytic effects at different times after injection. An
anxiolytic effect was also observed 30 min after the second nicotine injection,
and the anxiogenic effect observed 5 min after injection remained after 4 days of
nicotine administration. However, after 7 days of nicotine treatment, tolerance
was observed to both these effects. When rats were tested 72 h after the last of
7 or 14 days of nicotine treatment, an anxiogenic withdrawal response was
observed. Thus, an oppositional mechanism may underlie tolerance to the
anxiolytic effects, whereas there is as yet no evidence for this type of
mechanism mediating tolerance to the anxiogenic effects.
PMID- 10780512
TI - Locomotor behavioral effects of prenatal and postnatal nicotine exposure in rat
offspring.
AB - The purpose of this study was to determine if prenatal/postnatal nicotine
exposure results in hyperactive offspring. Rat offspring were exposed to
nicotine, through implantation of osmotic minipumps in dams, at levels of 0.75,
1.5 and 3.0 mg/kg/day, for 19 days prenatally and 16 days postnatally. Offspring
were measured for gestation length, body weight, litter size, sex difference and
locomotor activity. No significant effects were shown for gestation length,
litter size or male to female pup ratio. However, higher percentage of pup deaths
resulted from nicotine-exposed dams than from control dams. Significantly less
litter body weight was shown in nicotine-exposed offspring on postnatal day 1
when compared to controls. However, these offspring surpassed the control groups
in litter body weight on postnatal day 14 and 21. Hyperactivity was shown in
offspring exposed to prenatal/postnatal nicotine at levels of 0.75 and 3.0
mg/kg/day on postnatal day 14, but not on postnatal day 21 or at the 1.5
mg/kg/day condition. Results are consistent with the hypothesis that rat
offspring are susceptible to the neurochemical and neurobehavioral effects of
prenatal/postnatal nicotine exposure.
PMID- 10780513
TI - Chemotherapy for high-grade gliomas.
PMID- 10780514
TI - Bisphosphonates in the adjuvant treatment of cancer: experimental evidence and
first clinical results. International Bone and Cancer Study Group (IBCG).
AB - Several animal models, as well as a number of cell culture experiments, indicate
a prophylactic effect of bisphosphonates in respect of subsequent bone
metastasis. Moreover, in preliminary clinical trials involving patients with
advanced breast cancer and local or remote metastases, biophosphonates produced a
reduction in new skeletal metastases. This overview summarizes and discusses the
results of the latest investigations. It opens with a section on the
pathophysiology of bone metastasis, which is followed by a report on animal
models and first studies of bisphosphonate treatment as a new approach in
systemic adjuvant therapy.
PMID- 10780515
TI - Treatment, long-term outcome and prognostic variables in 214 unselected AML
patients in Sweden.
AB - With the aim of describing an unselected series of acute myeloid leukaemias (AML)
in adults, patients diagnosed 1987-1992 in the Orebro region of central Sweden
were reviewed by investigating hospital records. By utilizing: (1) The Swedish
Cancer Registry, (2) The Cause of Death Registry, (3) listings of pathology bone
marrow reports and (4) listings of inpatient discharge diagnoses, we attempted to
find all patients. Among secondary AML, only blast-crises of CML were excluded. A
total of 214 cases of AML with a median age of 69.5 years were verified
corresponding to a mean yearly incidence in adults of 5.4/100 000. Of all
patients, 56% had received 'high-dose' induction treatment, 28% 'low-dose'
treatment and 16% no cytostatic treatment. Median survival for all patients was
5.8 months and the probability of survival at 5 years was 9.3%. The 120 'high
dose' treated patients had a total CR rate of 67%, median CR duration 10.1 months
and median survival 11.4 months. Age, LDH and kidney function were found to be
independent prognostic variables for survival. The inclusion of patients
unreferred from district hospitals makes this study unique as an example of
unselected AML.
PMID- 10780516
TI - Treatment of persistent trophoblastic disease later than 6 months after diagnosis
of molar pregnancy.
AB - Of 4257 patients with gestational trophoblastic disease (GTD) registered between
1986 and 1996 with the Trophoblastic Screening and Treatment Centre, Sheffield,
231 women required chemotherapy; 28 were treated 24 weeks or more after the
initial evacuation of products of conception. In 18 patients late treatment was a
result of a predetermined watch and wait policy on the part of the Centre; these
patients formed the study group. Patients were identified from the Centre's
computer database. The time interval from first evacuation (diagnosis) to start
of chemotherapy was calculated for each patient. Hospital records were reviewed
when the interval of observation was 24 weeks or greater to determine patient
characteristics, treatment and outcome. Eighteen women were treated 'late'
(according to Centre policy), with a median age of 30 years (range 21-57 years).
The interval from diagnosis to treatment ranged from 24 to, in one case, 56 weeks
(median 33 weeks). Fourteen of 18 women had complete moles, 3/18 had partial
moles and one had unclassified disease. All women had low-risk disease and were
treated with single-agent methotrexate; 17 were cured with this regimen, one also
required salvage chemotherapy. In conclusion, where a successful surveillance
programme is in operation for GTD, a wait and watch policy can be adopted without
compromising patients whose definitive treatment is commenced more than 6 months
after the initial diagnosis.
PMID- 10780518
TI - Germline mutations of the STK11 gene in Korean Peutz-Jeghers syndrome patients.
AB - Peutz-Jeghers syndrome (PJS) is an autosomal dominantly inherited disease
characterized by hamartomatous gastrointestinal polyps and mucocutaneous
pigmentation, with an increased risk for various neoplasms, including
gastrointestinal cancer. Recently, the PJS gene encoding the serine/threonine
kinase STK11 (also named LKB1) was mapped to chromosome 19p13.3, and germline
mutations were identified in PJS patients. We screened a total of ten Korean PJS
patients (nine sporadic cases and one familial case including two patients) to
investigate the germline mutations of the STK11 gene. By polymerase chain
reaction-single-strand conformation polymorphism and DNA sequencing analysis,
three kinds of mis-sense mutation and a frame-shift mutation were identified:
codon 232 (TCC to CCC) in exon 5, codon 256 (GAA to GCA) in exon 6, codon 324
(CCG to CTG) in exon 8, and a guanine insertion at codon 342 resulting in a
premature stop codon in exon 8. These mis-sense variants were not detected in 100
control DNA samples. Furthermore, we found an intronic mutation at the
dinucleotide sequence of a splice-acceptor site: a one base substitution from AG
to CG in intron 1, which may cause aberrant splicing. Most reported germline
mutations of the STK11 gene in PJS patients were frame-shift or non-sense
mutations resulting in truncated proteins. Together, these findings indicate that
germline mis-sense mutations of the STK11 gene are found in PJS patients in
addition to truncating mutations. The effects of these mutations on protein
function require further examination. In summary, we found germline mutations of
the STK11 gene in five out of ten Korean PJS patients.
PMID- 10780517
TI - Improved outcome in children with advanced stage B-cell non-Hodgkin's lymphoma (B
NHL): results of the United Kingdom Children Cancer Study Group (UKCCSG) 9002
protocol.
AB - From July 1990 to March 1996, 112 children with stage III or IV B-cell non
Hodgkin's lymphoma (B-NHL) with up to 70% FAB L3-type blasts (n = 42) in the bone
marrow without central nervous system (CNS) disease were treated on the United
Kingdom Children Cancer Study Group (UKCCSG) 9002 protocol (identical to the
French LMB 84). The median age was 8.3 years. There were 81 boys and 31 girls.
According to the extent of the primary disease, patients were sub-staged into
three groups: IIIA with unresectable abdominal tumour (n = 39); IIIB with
abdominal multiorgan involvement (n = 57) and IIIX with extra-abdominal primary
lymphoma often presenting as pleural effusion (n = 16). Univariate and
multivariate analyses were carried out to evaluate the prognostic significance of
lactate dehydrogenase (LDH) level at diagnosis, the sub-stage and the time to
achieve complete remission (CR). With a median follow up of 48 months (range 12
92), the overall and event free survival (EFS) is 87% (95% confidence interval
(CI) 79.2-92.1 %) and 83.7% (95% CI 76.3-89.2%) respectively. Six patients (5.4%)
never achieved CR, of whom one is alive following high-dose therapy. Eight
patients (7.1%) relapsed after achieving CR, three are alive after second-line
therapy. There were three early toxic deaths (2.7%), mainly from infection, and
one late death from a second cancer. There was no significant difference in EFS
according to LDH level at diagnosis, the sub-stage or the time to CR. This study
confirms the overall good prognosis and low rate of toxic deaths in patients with
advanced B-NHL treated with this intensive regimen. No significant difference in
EFS according to the sub-stage, the time to achieve CR or LDH level at diagnosis
making it difficult to identify a group that should not receive intensive
therapy.
PMID- 10780519
TI - Interphase cytogenetics of multicentric renal cell tumours confirm associations
of specific aberrations with defined cytomorphologies.
AB - To demonstrate associations of certain chromosomal aberrations with defined renal
cell tumour (RCT) subtypes, we analysed 239 tumour nephrectomy cases for
specimens with multicentric tumours. Chromosomal in situ hybridization was then
performed on 15 cases with 34 foci (16 conventional renal cell carcinomas (RCCs),
and 18 papillary RCTs (11 carcinomas and seven adenomas) for specific chromosomal
aberrations, using alpha-satellite probes for chromosomes 3, 7 or 17. Particular
preference was given to cases which had separate foci with different
cytomorphologies. Furthermore, we compared aberrations in relation to tumour
size, stage, grade and between different foci in a specimen. Thirty-four cases
had multiple tumours. Forty-seven per cent of the multicentric tumours were
conventional RCCs and 53% papillary RCTs (against 83% solitary conventional RCCs
and 5% solitary papillary RCTs). Three conventional RCCs sized 8 mm (G3), 13 cm
(pT2, G2) and 15 cm (pT3b, G3), respectively, revealed monosomy 3, and 13 were
disomic. Seventeen papillary RCTs (11 carcinomas and six adenomas) displayed
trisomy 17, irrespective of size or grade. Four papillary carcinomas and six
papillary adenomas had trisomy 7, and the rest (seven papillary carcinomas and
one papillary adenoma) revealed disomy 7. In conclusion, papillary RCTs were
tendentially multicentric. Although specific for conventional RCCs heedless of
size, monosomy 3 was only observed in high-grade and/or advanced tumours. Trisomy
17 was only detectable in papillary RCTs irrespective of tumour state, showing
increased copies with tumour growth. Papillary RCTs also appeared to lose some
copies of chromosome 7 with tumour progress, possibly reflecting malignancy.
PMID- 10780520
TI - Presence of activin signal transduction in normal ovarian cells and epithelial
ovarian carcinoma.
AB - In this study, we have investigated the expression of inhibin subunits and
activin receptors (ActRs) in normal and malignant ovarian cells. Each product of
the inhibin subunits (alpha, betaa, betab) and activin receptors (ActRs)
amplified by reverse transcription polymerase chain reaction were detected as a
single band in human granulosa cells, surface epithelial cells (OSE), and the
ovarian cancer cell lines OVCAR 3 and SKOV 3. Western blot analysis was performed
using polyclonal antibodies against ActR IIa or IIb peptides based on 13 COOH
terminal amino acids; cultured human granulosa cells were used as a positive
control. Using ActR IIa antibody, one major band corresponding to approximately
80 kDa and one minor band corresponding to 105 kDa were observed in the samples.
One single band at approximately 60 kDa was detected in OVCAR 3 and a 50 kDa band
was detected with ActR IIb antibody in cultured granulosa cell, OSE and SKOV 3.
Although no detectable change was induced in Smad 4 mRNA in OVCAR 3, Smad 2 mRNA
levels were increased during 48 h treatment with activin A (50 ng ml(-1)). These
data provide a better understanding as the first step in the mechanism of action
of the activin in the epithelial ovarian carcinoma.
PMID- 10780521
TI - A simplified and reliable HPV testing of archival Papanicolaou-stained cervical
smears: application to cervical smears from cancer patients starting with
cytologically normal smears.
AB - The efficacy of four methods to recover DNA from Papanicolaou (Pap)-stained
archival cervical smears for optimal detection of human papillomavirus (HPV) DNA
by GP5+/bioGP6+ polymerase chain reaction (PCR) was investigated. Two of the
methods were based on proteinase K treatment and two based on treatment with
guanidinium thiocyanate (GTC). The quality of the DNA as measured by PCR assays
amplifying different sizes of the beta-globin gene appeared to be superior for
the GTC-based assays. Using competitive beta-globin PCR assays, one of the GTC
based, assays, provisionally named High Pure PCR Template Preparation (HPPTP)
assay, yielded by far the highest quantity of amplifiable DNA. It allowed the
recovery of 2.2 x 10(5) to 3 x 10(5) genome equivalents in smears containing 5 x
10(5) to 20 x 10(5) nucleated cells, indicating a mean efficiency of 26% (range
of 15-44%). In contrast, the other methods revealed markedly lower efficiencies
varying from 1% to 10%. The use of the HPPTP assay as a reliable processing
procedure was validated by demonstrating a complete agreement in HPV detection
and 93% agreement in HPV typing between 39 archival Pap-stained and paired fresh
frozen cervical smears. This method was applied to 40 archival smears from ten
cervical cancer patients (selected from a group of 200 patients) which had a
history of 3-6 smears with the first smear being Pap 1 or 2 taken at least 5
years before cancer was diagnosed. The average time period between the first Pap
1/2 smear that contained the same HPV type as in the corresponding carcinoma and
diagnosis of cervical cancer was 12.0 +/- 2.9 years. All subsequent smears were
invariably positive for the same HPV type which was also found in the cervical
cancer biopsy. In conclusion, the HPPTP assay provides a reliable and efficient
means to extract DNA from Pap-stained archival cervical smears for the detection
of HPV DNA by PCR and would be the method of choice for future HPV analysis of
archival Pap-stained cervical smears.
PMID- 10780522
TI - Vascular endothelial growth factor, platelet-derived endothelial cell growth
factor and angiogenesis in non-small-cell lung cancer.
AB - High microvessel density, an indirect measure of angiogenesis, has been shown to
correlate with increased tumour size, lymph node involvement and poor prognosis
in non-small-cell lung cancer (NSCLC). Tumour cell vascular endothelial growth
factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF)
expression correlate with angiogenesis and a poor outcome in this disease. In a
retrospective study VEGF and PD-ECGF expression and microvessel density were
evaluated immunohistochemically in surgically resected specimens (T1-3, N0-2)
from 223 patients with operable NSCLC using the VG1, P-GF.44C and JC70 monoclonal
antibodies respectively. High VEGF immunoreactivity was seen in 104 (46.6%) and
PD-ECGF in 72 (32.3%) cases and both were associated with high vascular grade
tumours (P= 0.009 and P= 0.05 respectively). Linear regression analysis revealed
a weak positive correlation between VEGF and PD-ECGF expression in cancer cells
(r= 0.21; P = 0.002). Co-expression of VEGF and PD-ECGF was not associated with a
higher microvessel density than VEGF or PD-ECGF only expressing tumours.
Furthermore a proportion of high vascular grade tumours expressed neither growth
factor. Univariate analysis revealed tumour size, nodal status, microvessel
density and VEGF and PD-ECGF expression as significant prognostic factors. Tumour
size (P < 0.02) and microvessel density (P < 0.04) remained significant on
multivariate analysis. In conclusion, VEGF and PD-ECGF are important angiogenic
growth factors and have prognostic significance in NSCLC. Furthermore the study
underlines the prognostic significance of microvessel density in operable NSCLC.
PMID- 10780523
TI - Expression of alpha(v)beta6 integrin in oral leukoplakia.
AB - The distribution of alpha(v)beta6 integrin was examined in oral leukoplakia,
lichen planus and squamous cell carcinomas using immunohistochemistry. Controls
included oral mucosal wounds, chronically inflamed and normal oral mucosa.
Integrins beta1, beta3, beta4, beta5, fibronectin and tenascin were also studied.
The integrin alpha(v)beta6 was highly expressed throughout the whole lesion of
90% of the squamous cell carcinomas but was not present in any of the normal
specimens. alpha(v)beta6 integrin was also expressed in 41% of the leukoplakia
specimens, and 85% of the lichen planus samples, but in none of the tissues with
inflammatory hyperplasia or chronic inflammation. The expression of beta1
integrins was localized in the basal layer, and that of the beta4 at the cell
surface facing the basement membrane of all specimens. The integrins beta3 and
beta5 were absent from all normal and leukoplakia specimens. Fibronectin and
tenascin were present in the connective tissue underneath the epithelium of all
the sections, and their expression was similar in both alpha(v)beta6-positive and
alpha(v)beta6-negative tissues. A group of 28 leukoplakia patients were followed
1-4 years after first diagnosis. In this group, initially alpha(v)beta6 integrin
positive leukoplakia specimens had high tendency for disease progression while
alpha(v)beta6-negative specimens did not progress. These results suggest that the
expression of alpha(v)beta6 integrin could be associated in the malignant
transformation of oral leukoplakias.
PMID- 10780524
TI - Proliferation, bcl-2 expression and angiogenesis in pituitary adenomas:
relationship to tumour behaviour.
AB - The prediction of pituitary tumour behaviour, in terms of response to treatment
from which can be derived optimal management strategies, is a challenge that has
been approached using several different means. Angiogenesis in other tumour types
has been shown to be correlated with poor response to treatment and tumour
recurrence. The aim of this paper is to assess the role of measurements of cell
proliferation and angiogenesis in predicting pituitary tumour behaviour. The
proliferative capacity of the tumour was assessed using the Ki-67 labelling index
(LI) while bcl-2 expression was used to assess anti-apoptotic pathways. The
microvessel density (MVD) was assessed using antibodies to CD31 and factor VIII
related antigen, and with biotinylated ulex europaeus agglutinin I. There was no
difference between Ki-67 LI and MVD of functionless tumours that recurred and
those that did not, but bcl-2 expression was significantly lower in tumours that
subsequently regrew. Macroprolactinomas had significantly higher LI than
microprolactinomas and than all other tumours. Cell proliferation and
angiogenesis were not related, showing that both processes are under different
control mechanisms in pituitary tumours. In contrast there was a positive
relationship between markers of angiogenesis and bcl-2 expression in
prolactinomas, GH-secreting tumours and non-recurrent functionless tumours with
higher levels of bcl-2 expression being found in the more vascular tumours. These
findings may suggest that angiogenesis is related to the ability of tumour cells
to survive rather than their proliferative activity.
PMID- 10780525
TI - Expressions of Fas ligand and other apoptosis-related genes and their prognostic
significance in epithelial ovarian neoplasms.
AB - Expression of apoptosis-related proteins, bcl-2, Bax, Fas and Fas ligand (L), in
ovarian epithelial neoplasms together with its clinical relevance was examined by
immunohistochemistry. They included 36 cases with adenoma, 33 with low potential
malignancy (LPM) and 63 with carcinomas. bcl-2 expression was observed in 14 of
36 cases (39%) with adenoma, five of 33 (15%) with LPM (P< 0.05) and 12 of 63
(19%) with carcinoma (P < 0.05). Cases with bcl-2 expression showed more
favourable prognosis than those without, but the difference was not statistically
significant. There was no difference in frequency of Bax and Fas expression
between each histologic category. Fas L expression was observed in one of 36
cases (3%) with adenoma, but in 12 of 33 (36%) with LPM (P < 0.001) and 42 of 63
(67%) with carcinoma (P < 0.0001). In carcinomas, cases expressing Fas L showed a
less favourable prognosis than those without (P = 0.02). Density of CD8+
lymphocytes, possibly cytotoxic T-cells, was higher in serous carcinoma with
negative Fas L expression than those with positive Fas L expression. These
findings suggest that Fas L expressing carcinomas induce apoptosis in
infiltrating CTL with Fas expression, and escape from immune surveillance.
PMID- 10780526
TI - Expression of SCF splice variants in human melanocytes and melanoma cell lines:
potential prognostic implications.
AB - Stem cell factor (SCF), the ligand for c-Kit, is known to regulate developmental
and functional processes of haematopoietic stem cells, mast cells and
melanocytes. Two different splice variants form predominantly soluble (sSCF or
SCF-1) and in addition some membrane-bound SCF (mSCF or SCF-2). In order to
explore the prognostic significance of these molecules in melanoma, total SCF,
SCF splice variants and c-Kit expression were studied in normal skin melanocytes
and in 11 different melanoma cell lines, using reverse transcription polymerase
chain reaction, immunocytochemistry and enzyme-linked immunosorbent assay. Nine
of the 11 melanoma cell lines expressed SCF-1 mRNA, only two of them SCF-2, and
these two also SCF-1. Coexpression of both SCF-1 and c-Kit was noted in five cell
lines, and only one cell line as well as normal melanocytes expressed both SCF-1
and SCF-2 as well as c-Kit. Corresponding results were obtained on
immunocytochemical staining. Of three exemplary melanoma cell lines studied, two
expressing SCF mRNA also released SCF spontaneously and on stimulation, whereas
the line lacking SCF and c-kit mRNA (SK-Mel-23) failed to do so. These data
demonstrate thus that melanoma cell lines, particularly those known to
metastasize in vivo, lose the ability to express SCF-2 mRNA, suggesting that this
molecule may serve, next to c-Kit, as a prognostic marker for malignant melanoma.
PMID- 10780527
TI - Bisphosphonates induce apoptosis in human breast cancer cell lines.
AB - Breast cancer has a prodigious capacity to metastasize to bone. In women with
advanced breast cancer and bone metastases, bisphosphonates reduce the incidence
of hypercalcaemia and skeletal morbidity. Recent clinical findings suggest that
some bisphosphonates reduce the tumour burden in bone with a consequent increase
in survival, raising the possibility that bisphosphonates may have a direct
effect on breast cancer cells. We have investigated the in vitro effects of
bisphosphonates zoledronate, pamidronate, clodronate and EB 1053 on growth,
viability and induction of apoptosis in three human breast cancer cell lines (MDA
MB-231, Hs 578T and MCF-7). Cell growth was monitored by crystal violet dye
assay, and cell viability was quantitated by MTS dye reduction. Induction of
apoptosis was determined by identification of morphological features of apoptosis
using time-lapse videomicroscopy, identifying morphological changes in nucleis
using Hoechst staining, quantitation of DNA fragmentation, level of expression of
bcl-2 and bax proteins and identification of the proteolytic cleavage of Poly
(ADP)-ribose polymerase (PARP). All four bisphosphonates significantly reduced
cell viability in all three cell lines. Zoledronate was the most potent
bisphosphonate with IC50 values of 15, 20 and 3 microM respectively in MDA-MB
231, MCF-7 and Hs 578T cells. Corresponding values for pamidronate were 40, 35
and 25 microM, whereas clodronate and EB 1053 were more than two orders of
magnitude less potent. An increase in the proportion of cells having
morphological features characteristic of apoptosis, characteristic apoptotic
changes in the nucleus, time-dependent increase in the percentage of fragmented
chromosomal DNA, down-regulation in bcl-2 protein and proteolytic cleavage of
PARP, all indicate that bisphosphonates have direct anti-tumour effects on human
breast cancer cells.
PMID- 10780528
TI - Enhancement of the anti-tumour effect of cyclophosphamide by the bioreductive
drugs AQ4N and tirapazamine.
AB - The ability of the bioreductive drugs AQ4N and tirapazamine to enhance the anti
tumour effect of cyclophosphamide was assessed in three murine tumour models. In
male BDF mice implanted with the T50/80 mammary carcinoma, AQ4N (50-150 mg kg(
1)) in combination with cyclophosphamide (100 mg kg(-1)) produced an effect
equivalent to a single 200 mg kg 1 dose of cyclophosphamide. Tirapazamine (25 mg
kg(-1)) in combination with cyclophosphamide (100 mg kg(-1)) produced an effect
equivalent to a single 150 mg kg(-1) dose of cyclophosphamide. In C3H mice
implanted with the SCCVII or RIF-1 tumours, enhancement of tumour cell killing
was found with both drugs in combination with cyclophosphamide (50-200 mg kg(
1)); AQ4N (50-200 mg kg(-1)) produced a more effective combination than
tirapazamine (12.5-50 mg kg(-1)). Unlike tirapazamine, which showed a significant
increase in toxicity to bone marrow cells, the combination of AQ4N (100 mg kg(
1)) 6 h prior to cyclophosphamide (100 mg k(-1)) resulted in no additional
toxicity towards bone marrow cells compared to that caused by cyclophosphamide
alone. In conclusion, AQ4N gave a superior anti-tumour effect compared to
tirapazamine when administered with a single dose of cyclophosphamide (100 mg kg(
1)).
PMID- 10780529
TI - Characterization of antigen-presenting properties of tumour cells using virus
specific cytotoxic T lymphocytes.
AB - Immunotherapy of tumours by induction of tumour-specific cytotoxic T-lymphocytes
(CTLs) will only be effective for tumours with a functional antigen processing
and presentation machinery. However, many tumours are known to down-regulate
expression of major histocompatibility complex (MHC) class I molecules and/or to
impair antigen processing. It is therefore desirable to evaluate the ability of a
given tumour to present antigenic epitopes before developing an immunotherapy
protocol. In this study we have used influenza virus as a tool to determine the
antigen-presenting capacities of the murine neuroblastoma C1300 cell line NB41A3,
a frequently used model for human neuroblastoma. Immunofluorescence analyses
revealed low and moderate expression of MHC class I molecules Dd and Kk
respectively. Nevertheless, infected NB41 A3 cells were lysed efficiently by
influenza-specific CTLs. These results demonstrate that all steps of the antigen
processing pathway function properly in the NB tumour cells, and that the limited
MHC class I expression suffices for efficient recognition by CTLs. In addition,
lysis of the NB tumour cells shows that the cells are susceptible to CTL-induced
apoptosis, a pathway that is often impaired in tumour cells. These
characteristics make neuroblastoma a suitable target for immunotherapy. The
presented assay allows evaluation of various immunological properties of tumour
cells and, thus, represents a valuable tool to assess whether a given tumour will
be susceptible to immunotherapy or not.
PMID- 10780530
TI - Suppression of proline-directed protein kinase F(A) expression inhibits the
growth of human chronic myeloid leukaemia cells.
AB - Initial studies revealed that proline-directed protein kinase F(A) (PDPK F(A))
was overexpressed in various cancerous tissues relative to normal controls.
However, the functional role of overexpressed PDPK F(A) in cancer remains to be
established. In this report, we explore the potential role of PDPK F(A) in
leukaemia cell growth by investigating the effects of partial inhibition of this
kinase on the malignant phenotype of human chronic myeloid leukaemia cells
(K562). Cloning of PDPK F(A) cDNA and its recombinant antisense expression vector
and PDPK F(A)-specific antibody were successfully developed. Two stable antisense
clones of K562 cells were subcloned which expressed 70% and 45% of PDPK F(A)
respectively, compared with control-transfected clone in both immunoprecipitate
activity assay and immunoblot analysis. In sharp contrast, these two antisense
clones expressed no significant suppression of any other related PDPK family
members, indicating the specificity of these two antisense clones. Moreover,
these antisense clones proportionally and potentially exhibited cell growth
retardation, poor clonogenic growth in soft agar and loss of serum independence.
The results demonstrate that specific antisense suppression of PDPK F(A) is
sufficient to interfere with the growth of K562 cells, indicating that PDPK F(A)
is essential for human chronic myeloid leukaemia cell growth.
PMID- 10780532
TI - The "crowding effect" in tapeworm infections. 1950.
PMID- 10780531
TI - Potentiation of the anti-tumour effects of Photofrin-based photodynamic therapy
by localized treatment with G-CSF.
AB - Photofrin-based photodynamic therapy (PDT) has recently been approved for
palliative and curative purposes in cancer patients. It has been demonstrated
that neutrophils are indispensable for its anti-tumour effectiveness. We decided
to evaluate the extent of the anti-tumour effectiveness of PDT combined with
administration of granulocyte colony-stimulating factor (G-CSF) as well as the
influence of Photofrin and G-CSF on the myelopoiesis and functional activity of
neutrophils in mice. An intensive treatment with G-CSF significantly potentiated
anti-tumour effectiveness of Photofrin-based PDT resulting in a reduction of
tumour growth and prolongation of the survival time of mice bearing two different
tumours: colon-26 and Lewis lung carcinoma. Moreover, 33% of C-26-bearing mice
were completely cured of their tumours after combined therapy and developed a
specific and long-lasting immunity. The tumours treated with both agents
contained more infiltrating neutrophils and apoptotic cells then tumours treated
with either G-CSF or PDT only. Importantly, simultaneous administration of
Photofrin and G-CSF stimulated bone marrow and spleen myelopoiesis that resulted
in an increased number of neutrophils demonstrating functional characteristics of
activation. Potentiated anti-tumour effects of Photofrin-based PDT combined with
G-CSF observed in two murine tumour models suggest that clinical trials using
this tumour therapy protocol would be worth pursuing.
PMID- 10780533
TI - The crowding effect revisited. 1951.
PMID- 10780534
TI - The ecology of "crowding".
PMID- 10780535
TI - Attachment-inducing capacities of fish tissue extracts on oncomiracidia of
Neobenedenia girellae (Monogenea, Capsalidae).
AB - When oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae) were
incubated in wells with lyophilized extracts of fish skin epithelia on the
bottom, some attached to the well bottom with the haptor unfolded and shed the
ciliated epidermal cells. Based on these morphological changes in oncomiracidia,
we developed a new assay method to examine the attachment-inducing capacities of
various fish extracts for oncomiracidia. Attachment-inducing capacities were
found only in extracts of fish skin epithelium and not in other fish extracts. No
significant difference in capacities was observed among extracts of skin
epithelia of 4 fish species. Wheat germ lectin and concanavalin A suppressed
capacities in extracts of skin epithelia of Japanese flounder and yellowtail,
respectively. Suppressed capacities were recovered by adding sugars that bound
specifically to these lectins. These results indicate that some sugar-related
chemical substances that exist specifically in fish epithelium induce the
attachment of N. girellae oncomiracidia.
PMID- 10780536
TI - Proteinase activities in total extracts and in medium conditioned by Acanthamoeba
polyphaga trophozoites.
AB - Acanthamoeba species can cause granulomatous encephalitis and keratitis in man.
The mechanisms that underlie tissue damage and invasion by the amoebae are poorly
understood, but involvement of as yet uncharacterized proteinases has been
suggested. Here, we employed gelatin-containing gels and azocasein assays to
examine proteinase activities in cell lysates and in medium conditioned by
Acanthamoeba polyphaga trophozoites. Azocasein hydrolysis by cell lysates was
optimally detected at pH 4.0-5.0 and was predominantly associated with the
activity of cysteine proteinases. Compatible with enzyme activation during
secretion, culture supernatants additionally contained a prominent azocasein
hydrolyzing activity attributable to serine proteinases; these enzymes were
better detected at pH 6.0 and above, and resolved at 47, 60, 75, 100, and >110
kDa in overlay gelatin gels. Although a similar banding profile was observed in
gels of trophozoite lysates, intracellular serine proteinases were shown to be
activated during electrophoresis and to split the substrate during migration in
sodium dodecyl sulfate gels. Blockage of serine proteinases with
phenylmethylsulfonylfluoride prior to electrophoresis permitted the detection of
43-, 59-, 70-, and 100-130-kDa acidic cysteine proteinases in cell lysates, and
of 3 (43, 70, and 130 kDa) apparently equivalent enzymes in culture supernatants.
Under the conditions employed, no band associated with a metalloproteinase
activity could be depicted in substrate gels, although the discrete inhibition of
supernatants' azocaseinolytic activity by 1,10-phenanthroline suggested secretion
of some metalloproteinase.
PMID- 10780538
TI - Relationship between structure and stability of a Halipegus occidualis component
population in green frogs: a test of selective treatment.
AB - The aggregated nature of helminth parasite populations has led to the suggestion
that selectively treating heavily infected hosts can efficiently reduce parasite
abundance and morbidity within a host population. Moreover, it has been
postulated that a selective treatment protocol might have long-term effects on
parasite transmission by disrupting the stability attributed to aggregated
parasite population distributions by theoretical models. Long-term investigation
has demonstrated year-to-year consistency in the population dynamics of Halipegus
occidualis in green frogs from Charlie's Pond, North Carolina. In 1996, removal
of all but 1 worm from each frog with > or =15 worms reduced the estimated
component worm population by 45%, thereby decreasing mean intensity and
aggregation (variance-to-mean ratio) of H. occidualis in the frogs by 85% and
63%, respectively. The following year, mean intensity, aggregation, and host
colonization trends returned to pretreatment levels, indicating no effect of worm
removal and demonstrating the stability of this host-parasite system. Although
this result might be attributable to inefficient treatment or the presence of
infection reservoirs, it is suggested that parasite population stability in this
system might be governed by prevalence rather than intensity of adult worms.
Therefore, repeated selective treatment might effectively modify intensity
dependent morbidity in similar host-parasite systems but should not affect
further parasite transmission.
PMID- 10780537
TI - Quantifying parasites in samples of hosts.
AB - Whereas terminological recommendations require authors to use mean intensity or
mean abundance to quantify parasites in a sample of hosts, awkward statistical
limitations also force them to use either the median or the geometric mean of
these measures when making comparisons across different samples. Here, we propose
to reconsider this inconsistent practice by giving priority to biological realism
in the interpretation of different statistical descriptors and choosing the
statistical tools appropriate to our decisions. Prevalence, mean intensity, and
indices of parasite distribution (such as median intensity) are suitable
descriptors to quantify parasites in a sample of hosts. These measures have
different biological interpretations and need different statistical methods to be
compared between samples.
PMID- 10780539
TI - Margolisius abditus n. gen., n. sP. (Copepoda: Lernaeopodidae) from gill lamellae
of a remora (Remora remora) collected in the Gulf of California.
AB - Margolisius abditus n. gen., n. sp. (Copepoda: Lernaeopodidae) is described from
female specimens collected from gill lamellae of a remora, Remora remora (L.),
captured in the Gulf of California near Punta Arena, Baja California. Comparison
of this species with 13 lernaeopodid genera with which it shares (a) absence of
posterior trunk processes; (b) presence of a relatively long cylindrical
cephalothorax, usually reflected along the dorsal surface of the trunk; and (c) a
marine habitat showed that it cannot be placed in any of them, thus necessitating
establishment of a new genus. Margolisius abditus n. sp. is the smallest known
lernaeopodid species, its ovigerous females measuring about 0.5 mm in total
length.
PMID- 10780540
TI - Dionchus postoncomiracidia (Monogenea: Dionchidae) from the skin of blacktip
sharks, Carcharhinus limbatus (Carcharhinidae).
AB - Postoncomiracidia of Dionchus sp. are described from specimens collected from the
skin of 2 blacktip sharks Carcharhinus limbatus, captured in the northern Gulf of
Mexico. The parasites resemble nonciliated oncomiracidia hatched from eggs laid
by Dionchus sp. on gills of a cobia Rachycentron canadum and adults of Dionchus
remorae that were collected from gills of a common sharksucker Echeneis
naucrates, captured in association with a third blacktip shark. The hamuli of the
postoncomiracidia were morphologically similar to those of adult D. remorae. This
is the first report of dionchids from an elasmobranch and from a location other
than the gills. These findings support the idea that some dionchid oncomiracidia
colonize the skin of sharks or other aquatic vertebrates that sponsor remoras,
prior to transferring to other remoras and maturing.
PMID- 10780541
TI - Tick infestations of birds in coastal Georgia and Alabama.
AB - Mist-netted birds were examined for ticks on Jekyll Island, Glynn Co., Georgia
(32 bird species) in 1996-1998, and at Fort Morgan, Baldwin Co., Alabama (36
species) in 1998 during fall migration. Sixty-two (14.7%) of 423 birds from
Jekyll Island and 22 (13.3%) of 165 birds from Fort Morgan were infested with
ticks. The mean number of ticks per infested bird was 2.0 on Jekyll Island and
6.3 at Fort Morgan. Ten species of birds were infested with ticks on Jekyl1
Island where 87% of all ticks were recovered from 3 species: the common
yellowthroat (Geothlypis trichas), gray catbird (Dumetella carolinensis), and
northern waterthrush (Seiurus noveboracensis). Eight species of birds were
infested with ticks at Fort Morgan where 83% of all ticks were recovered from 3
species: the brown thrasher (Toxostoma rufum), swamp sparrow (Melospiza
georgiana), and common yellowthroat. Six species of ticks (Amblyomma americanum,
Amblyomma maculatum, Haemaphysalis leporispalustris, Ixodes brunneus, Ixodes
minor, and Ixodes scapularis) were recovered from the Georgia birds, whereas 3
species (A. maculatum, H. leporispalustris, and Ixodes dentatus) were recovered
from the Alabama birds. Attempts to isolate Borrelia burgdorferi sensu stricto,
the etiologic agent of Lyme borreliosis, from Ixodes spp. ticks recovered from
birds were unsuccessful.
PMID- 10780543
TI - Effect of the digenean parasite Proterometra macrostoma on host morphology in the
freshwater snail Elimia livescens.
AB - Parasitism can affect size in gastropods by altering the host's growth rate, but
other morphological effects of parasitism have rarely been examined. In this
study, the relationship between variation in host morphology and parasitism was
examined in a population of the freshwater snail Elimia livescens. Differences
were found in the morphology of snails infected with the digenean Proterometra
macrostoma and uninfected snails. In order to differentiate between 2 hypotheses
to explain these differences in morphology, snails were experimentally infected
in the laboratory and several morphological traits were measured after 180 days.
One hypothesis suggests that parasite-induced changes in shell development
explain differences in morphology between infected and uninfected snails. The
other hypothesis suggests that selective mortality of infected hosts explains the
difference. In the experiment, differences were found between infected snails and
uninfected snails in overall size but not in any measurements of shape. The short
duration of the experiment relative to the duration of most infections may
account for why field-infected snails differed in shape but experimentally
infected snails did not. Parasite-induced changes in growth rate are the most
likely explanation for the larger size of infected snails relative to uninfected
snails.
PMID- 10780542
TI - Argentophilic structures of miracidia and cercariae of Philophthalmus lucipetus
(Philophthalmidae: Trematoda) from Israel.
AB - Argentophilic structures of Philophthalmus lucipetus miracidia and cercariae from
Israel are described. Eighty-four of 87 miracidia examined displayed an epidermal
plate arrangement of 6:8:4:2 = 20, similar to other Philophthalmus species.
Twenty papilla-like structures are arranged on the terebratorium in 3 groups,
along 1 axis. Sixteen body papillae are located at the bases of epidermal plates
of row 1. Eyespots are mediodorsal, between rows 1 and 2. Excretory pores are
lateral, between rows 2 and 3. Features common to Israeli and Bulgarian isolates,
differentiating them from other species, include the presence of 16 body papillae
as opposed to 10 in other species, and a maximum of 20 papillae on the
terebratorium as opposed to 19 in the others. About 3% of the miracidia displayed
different plate arrangements. Among the argentophilic structures of P. lucipetus
cercariae, the Israeli and Bulgarian P. lucipetus show a common pattern of 2-4
excretory pores in the tail, but arrangement of cephalic CI3 and CI5 papillae in
the 2 isolates is insufficiently unequivocal for species determination. The data
presented show that miracidial characteristics, rather than those of cercariae,
aid in determining the species of philophthalmids. They also support former
evidence attesting to the identity of the Bulgarian and Israeli species.
PMID- 10780544
TI - Ultrastructural analyses of the Caenorhabditis elegans sqt-1(sc13) left roller
mutant.
AB - The sqt-1 gene is 1 of the several loci in Caenorhabditis elegans that primarily
affects organismal morphology. Certain mutations in the sqt-1 gene can produce
left roller animals, i.e., they rotate around their long axis and move in
circular paths. We describe the morphological alterations seen in the cuticle of
the left roller sqt-1(sc13). Deep-etched replica analyses showed that the fibrous
layer is composed of a unique strand of parallel fibers, instead of the 2 meeting
at an angle of 60 degrees as observed in the wild-type strain. In addition,
honeycomb elements, fibers organized in a pentagonal fashion above the fibrous
layer, completely fill the intermediate layer that is empty spaces in the wild
type. These morphological alterations are likely to be involved in generating the
helical twist of the sqt-1(sc13) left roller mutant.
PMID- 10780545
TI - Presence of double-stranded RNAs in human and calf isolates of Cryptosporidium
parvum.
AB - We examined the occurrence of 2 virus-like double-stranded (ds)RNAs in human and
calf isolates of Cryptosporidium parvum senso latu and other microorganisms,
including 7 other members of the genus. A total of 32 isolates of C. parium, 16
from humans (5 from acquired immune deficiency syndrome patients) and 16 from
calves, were analyzed. Ethidium bromide staining, or Northern blot analysis, or
reverse transcription/polymerase chain reaction, or all 3 methods, revealed that
both genotype 1 and genotype 2 isolates of C. parvum possessed these dsRNAs. No
other Cryptosporidium spp. or other organisms examined possessed these dsRNAs.
Comparison analysis of partial cDNA sequences of dsRNAs from human and calf
isolates revealed a high degree of similarity (>92% and >93% identical
nucleotides for large and small dsRNAs, respectively). Slight, consistent
differences in nucleotide sequences could be seen at select sites and were
associated with an isolate being either genotype 1 or 2. Because of the
widespread distribution of the dsRNAs, the similarity of these molecules between
isolates, and high host specificity, these nucleic acids may prove to represent
species-specific molecular markers for C. parvum. Evidence also suggests that the
dsRNA can be utilized for molecular genotyping of C. parvum.
PMID- 10780546
TI - Evolutionary relationships among the Schistosomatidae (Platyhelminthes:Digenea)
and an Asian origin for Schistosoma.
AB - Schistosome blood flukes parasitize birds, mammals, and crocodilians and are
responsible for causing one of the great neglected diseases of humanity,
schistosomiasis. A phylogenetic study of 10 schistosome genera using
approximately 1,100 bases of the large subunit of the nuclear ribosomal gene
complex revealed 2 major clades. One clade is entirely mammalian and includes the
genera Schistosoma and Orientobilharzia. A close examination of relationships in
this group suggests that the medically important Schistosoma arose in Asia and
not in Africa as generally presumed and is paraphyletic. The second clade is
primarily avian, consisting of 6 genera of exclusively avian parasites and 2
genera of North American mammal flukes. These results indicate a secondary host
capture of mammals on the North American continent. This study provides little
evidence concerning the ancestral molluscan or vertebrate schistosome host but
does demonstrate that host switching has been an important feature of schistosome
evolution. Evidence also indicates that the reduced sexual dimorphism
characteristic of some avian schistosomes is derived evolutionarily.
PMID- 10780547
TI - Antigenic analysis of gamonts of Hepatozoon canis purified from leukocytes.
AB - Hepatozoon canis is a tick-borne apicomplexan parasite of dogs that infects
neutrophils and parenchymal tissues. To study the antigenic characteristics of
this parasite, a technique was devised for the purification of gamonts from
peripheral blood neutrophils. White blood cells were separated on Ficoll-Hypaque
density gradients and the gamonts were released from the host neutrophils by
nitrogen cavitation. The blood used for purification originated from dogs with
natural or experimental infections of H. canis with a parasitemia of 1.4-33%. The
number of parasites collected ranged from 1.5 X 10(6) to 4.2 X 10(7). Portions of
purified gamonts were separated and examined under phase and scanning electron
microscopy, and the remaining purified parasites were then used as a source of
antigens to characterize the humoral immune response by western blot analysis.
Serum antibodies from infected dogs recognized more than 15 gamont antigens, and
the antigenic patterns observed with sera from naturally and experimentally
infected dogs were nearly similar. Four immunodominant protein bands of relative
molecular weights of 107, 88, 63, and 28 kDa were recognized by all of the sera
examined. The technique applied here for the isolation of host cell-free gamonts
will facilitate studies on antigenic composition and immune responses against H.
canis and on antigenic relationships between Hepatozoon from different host
species and geographic regions.
PMID- 10780548
TI - Interferon- or interleukin-10 production is induced by related Trypanosoma cruzi
antigens.
AB - The purpose of this study was to evaluate the effects of a crude Trypanosoma
cruzi antigen (TCA) and its partially purified subfractions TCF1, TCF2 on
peripheral blood mononuclear cells (PBMC) of normal donors and chagasic patients.
TCFI and TCF2 stimulated cells from normal donors and chagasic patients in
association with a significant production of interleukin (IL)-10. Only PBMC from
chagasic patients multiplied after incubation with TCA and released mainly
interferon-y but also IL-10. Neither the production of IL-2 and IL-4 nor CD4/CD8
ratios were changed after culture with antigens. These data suggest that some
antigens active during the acute phase of T. cruzi infection would stimulate the
production of cytokines that promote progression of infection, and the immune
system can produce a desired cytokine(s) once the appropriate antigenic stimulus
is used.
PMID- 10780549
TI - Cytokine expression and specific lymphocyte proliferation in two strains of
Cryptosporidium parvum-infected gamma-interferon knockout mice.
AB - Differences in the immune response between 2 strains of interferon-gamma knockout
mice (BALB/c-GKO and C57BL/6-GKO) infected with Cryptosporidium parvum were
examined because the course of infection among these 2 strains is markedly
different. Infection of the BALB/c-GKO with C. parvum (2 X 10(6) oocysts/mouse)
resulted in slight weight loss, oocyst shedding, and recovery from infection by 2
wk postinfection (PI). Infection with 100 oocysts in the C57BL/6-GKO mice
resulted in significant weight loss, oocyst shedding, and death by day 10 PI.
Splenocytes from infected mice were able to proliferate in a dose-dependent
manner to soluble C. parvum-sporozoite antigen (SAg). In vitro stimulation with
SAg resulted in an increase in interleukin (IL)-2, IL-4, IL-5, and tumor necrosis
factor-alpha mRNA cytokine expression from splenocytes of infected BALB/cGKO
mice. In contrast, only IL-5 mRNA expression was increased in the splenocytes
from C. parvum-infected C57BL/6-GKO mice. Phenotypic analysis indicated no
significant differences in the splenic cell populations. Previous studies
indicated that susceptibility to C. parvum is dependent on CD4+ T cells and
interferon-gamma production. The present study indicates that although both of
these strains of knockout mice become infected with C. parvum, resolution of
infection may be in part dependent on the expression of Th2 cytokines.
PMID- 10780550
TI - Rescue of sporocysts of Schistosoma mansoni in nonsusceptible Biomphalaria by
head-foot transplantation into susceptible snails.
AB - To measure the longevity of sporocysts of Schistosoma mansoni in nonsusceptible
snails (13-16-R1 and Salvador strains of Biomphalaria glabrata, and Biomphalaria
obstructa), the head-foot (HF) of miracidia-exposed snails was transplanted into
the hemocoel of a susceptible NIH albino recipient at 1-36 days postexposure
(DPE). Recipient snails which were not exposed to miracidia then were monitored
for infection transferred by the implant, and infection prevalences in recipients
of HF transplants from nonsusceptible donors were compared to those in snails
implanted with an HF from NIH albino donors. Transplants from NIH albino snails
between 1 to 15 DPE infected 98% of recipients. Similarly, at 1 DPE, 69-85% of
transplants from nonsusceptible snails contained viable sporocysts, as shown by
resulting patent infections in the recipients. Recipient infection prevalence,
and presumably numbers of transplants containing viable sporocysts, declined as a
function of DPE, and by 5-9 DPE this decrease was significant for all 3 types of
nonsusceptible donors. However, viable sporocysts still occurred in B. obstructa
and 13-16-R1 B. glabrata as late as 19 and 20 DPE, respectively, and in Salvador
B. glabrata as late as 33 DPE. Thus, sporocysts persist in nonsusceptible snails
considerably longer than suggested by results of previous histological studies.
PMID- 10780551
TI - Morphology and life history of Petasiger variospinosus (trematoda:
echinostomatidae) in the Free State, South Africa.
AB - Specimens of the freshwater snail Bulinus tropicus (Krauss, 1848) collected in
the Free State, South Africa shed cercariae with an oral collar bearing 27
spines. Tadpoles of the African clawed toad Xenopus laevis laevis Daudin, 1802
collected from the same waters harbored metacercariae with a similar collar of
spines. Adults were obtained after feeding infected tadpoles to laboratory-reared
reed cormorants, Phalacrocorax africanus (Gmelin, 1789). The parasite was
identified as Petasiger variospinosus (Odhner, 1910), the life cycle was
experimentally completed, and stages described by the use of light and scanning
electron microscopy.
PMID- 10780552
TI - Natural transfer of helminths of marine origin to freshwater fishes with
observations on the development of Diphyllobothrium alascense.
AB - Infective stages of helminths of 5 species that occur as adults in marine mammals
were found in burbot, Lota lota (L.) (Gadidae), from the lower Kuskokwim River
(southwestern Alaska): Diphyllobothrium alascense Rausch et Williamson, 1958;
Pyramicocephalus phocarum (Fabricius, 1780); Corynosoma strumosum (Rudolphi,
1801); Corynosoma semerme (Forsell, 1904); and Pseudoterranova decipiens (Krabbe,
1878). Some larval stages were obtained also from smelt, Osmerus mordax dentex
Steindachner, an anadromous fish important as prey of burbot. Burbot, which are
freshwater fish, could become paratenic hosts of those helminths by means of at
least 3 interactions: by consuming marine fishes in brackish waters at river
mouths, by feeding on marine fishes that enter lower reaches of rivers, or by
preying on anadromous fishes as they migrate up rivers. Consumption of burbot by
people may result in infection by helminths of marine origin; of those recorded,
only P. decipiens may be significantly pathogenic. Attempts to rear P. phocarum
in dogs were unsuccessful. Plerocercoids of D. alascense, of very small size and
found only in the gastric lumen of burbot, readily infected dogs. For study of
their development, strobilae were obtained at intervals of 48 hr to 32 days
postinfection. In heavy infections, some strobilae developed slowly, while others
underwent rapid development.
PMID- 10780553
TI - Tritrichomonas foetus extracellular cysteine proteinase cleavage of bovine IgG2
allotypes.
AB - Bovine trichomoniasis is a sexually transmitted disease associated with
reproductive failure. Systemic immunization results in protective IgG antibodies
in uterine and vaginal secretions. Because bovine IgG2 is a better opsonin than
IgG1, it is potentially important in defense. Yet, Tritrichomonas foetus
extracellular cysteine proteinase (TFECP) cleaves bovine IgG2, evading protective
IgG2 responses. Variations in resistance of the 2 IgG2 allotypes to digestion may
explain inherited differences in protection. To address this hypothesis, TFECP
was incubated with both IgG2 allotypes at different concentrations and times. The
digestion products were separated by sodium dodecyl sulfate polyacrylamide gel
electrophoresis, stained, and quantitated by image analysis. IgG2a was digested
faster by TFECP than IgG2b. Differences in the sizes and numbers of digestion
products were observed, but the presence of bands the size of Fc and Fd fragments
indicated that both allotypes were cleaved at the hinge. Cysteine in the
digestion mixture reduced the antibody molecules and increased the rate of
digestion, but IgG2a was still more susceptible to cleavage than IgG2b in the
absence of cysteine. Thus, not only reduced H chains can be cleaved by cysteine
proteinase secreted by T. foetus but also intact functional antibody molecules.
Because parasites may evade protective antibody responses by cleaving IgG2,
animals with the more resistant IgG2b allotype may be better protected by
immunization than animals with the more readily digested IgG2a allotype.
PMID- 10780554
TI - Cloning and expression of a cysteine proteinase gene from Paragonimus westermani
adult worms.
AB - A gene encoding a cysteine proteinase from Paragonimus westermani has been cloned
and expressed in Escherichia coli. The cysteine proteinase cDNA fragment was
amplified by reverse transcription-polymerase chain reaction (RT-PCR) using
degenerate oligonucleotide primers derived from the conserved active site of the
cysteine proteinase. The 5' and 3' regions of the gene were amplified using a PCR
technique for the rapid amplification of cDNA ends. The cloned gene has an open
reading frame of 687 bp and deduced amino acid sequence of 229. Sequence analysis
and alignment showed significant homologies with the eukaryotic cysteine
proteinases and conservation of the Cys, His, and Asp residues that form a
catalytic triad. Analysis of the expressed protein on sodium dodecyl sulfate
polyacrylamide gel electrophoresis showed that the molecular weight of the
protein was approximately 28.5 kDa. The expressed protein reacted with the sera
of patients with paragonimiasis but not with the sera of fascioliasis and
clonorchiasis. These results suggest that the expressed protein may be valuable
as a specific diagnostic material for the immunodiagnosis of paragonimiasis.
PMID- 10780555
TI - A new Eimeria sP. from the plumbeous Central American caecilian, Dermophis
mexicanus (amphibia: gymnophiona) from Volcan Tajumulco, Department of San
Marcos, Guatemala.
AB - Fresh fecal samples from 5 caecilians (Dermophis mexicanus) were collected and
examined for coccidia in the summer of 1998. The caecilians were collected in the
Department of San Marcos, Guatemala. Two of the 5 (40%) specimens of caecilians
contained an Eimeria species that is described here as new. This represents the
first coccidia described from a gymnophionian host. Sporulated oocysts are
spheroidal to subspheroidal, 19.5 X 17.7 (16-23 x 15-21) microm, micropyle and
oocyst residuum are absent, and 3 (or more) polar granules are always present.
Sporocysts are ovoidal, 11.0 X 7.2 (10-12 x 6-9); a Stieda body and sporocyst
residuum are present.
PMID- 10780556
TI - Falcaustra kutcheri n. sP. (nematoda: kathlaniidae) from Geoemyda yuwonoi
(testudines: emydidae) from Sulawesi, Indonesia.
AB - Falcaustra kutcheri n. sp. (Nematoda: Kathlaniidae) from feces of the turtle
Geoemyda yuwonoi is described and illustrated. Falcaustra kutcheri n. sp.
represents the 68th species to be assigned to this genus and is distinguished
from other oriental species by the distribution pattern of caudal papillae of the
male: 10 pairs of sessile caudal papillae, 4 pairs precloacal, 1 pair adcloacal,
5 pairs postcloacal.
PMID- 10780557
TI - Molecular systematics of Mesocestoides sPP (cestoda: mesocestoididae) from
domestic dogs (Canis familiaris) and coyotes (Canis latrans).
AB - The genus Mesocestoides Vaillant, 1863 includes tapeworms of uncertain
phylogenetic affinities and with poorly defined life histories. We previously
documented 11 cases of peritoneal cestodiasis in dogs (Canis familiaris L.) in
western North America caused by metacestodes of Mesocestoides spp. In the current
study, DNA sequences were obtained from metacestodes collected from these dogs (n
= 10), as well as proglottids from dogs (n = 3) and coyotes (Canis latrans Say,
1823 [n = 2]), and tetrathyridia representing laboratory isolates of M. corti (n
= 3), and these data were analyzed phylogenetically. Two nuclear genetic markers,
18S ribosomal DNA and the second internal-transcribed spacer (ITS 2), were
sequenced. Phylogenetic analysis of the 18S rDNA data recovered a monophyletic
group composed of all samples of Mesocestoides spp., distinct from closely
related outgroup taxa (Amurotaenia Akhmerov, 1941 and Tetrabothrius Rudolphi,
1819). Initial analysis of the ITS 2 data resolved 3 clades within Mesocestoides.
Two proglottids from dogs formed a basal clade, a second clade was represented by
tetrathyridial isolates, and a third clade included all other samples.
Interpretation of these data from an apomorphy-based perspective identified 6
evolutionary lineages. We also assessed whether metacestodes from dogs (n = 4)
are capable of asexual proliferation in laboratory mice. One tetrathyridial and 2
acephalic isolates from dogs proliferated asexually. Further investigation is
warranted to determine which of the lineages represent distinct species and to
determine the life history strategies of Mesocestoides spp.
PMID- 10780558
TI - Description of Gordionus porosus n. sP. and redescription of Gordionus ondulatus
(Nematomorpha, parachordodinae) with scanning electron microscopy.
AB - Two hairworms from Argentina, Gordionus porosus n. sp. and Gordionus ondulatus
(Nematomorpha, Gordioidea), are described and illustrated. The cuticle of both
species shows only 1 areolar type. Areoles of G. porosus are polygonal and
surrounded by minute bristles and the interareolar groove is wide and with large
pores. Gordionus ondulatus is characterized by rectangular or irregular areoles
from which margins cuticular elongations project as finger-like structures,
giving an undulated appearance. Comparing these species to the remaining American
species of Gordionus, G. porosus is close to Gordionus violaceus by virtue of the
large number of small bristles surrounding the areoles and can be distinguished
by the shape of these bristles and by the arrangement and shape of the areoles.
Gordionus ondulatus differs from the other species of the genus by its undulating
margins. Giordinus lineatus and Giordinus violaceus have been reported in North
America, Giordinus platycephalus in North and Central America, Giordinus
capitosulcatus in Central America, and Giordinus prismaticus, G. ondulatus, and
G. porosus only in South America.
PMID- 10780559
TI - Phylogenetic relationships of Hepatozoon (Apicomplexa: Adeleorina) based on
molecular, morphologic, and life-cycle characters.
AB - To evaluate higher-level affinities of Hepatozoon species within Apicomplexa, we
sequenced the 18S rRNA gene from 2 parasites (Hepatozoon americanum and
Hepatozoon canis) of dogs and 1 (Hepatozoon catesbianae) of bullfrogs. Sequences
from other apicomplexans among the Sarcocystiidae, Eimeriidae, Theileriidae,
Plasmodiidae, Cryptosporiidae, and Babesiidae, a Perkinsus species and 2
dinoflagellates were obtained from GenBank. Phylogenetic analysis indicated that
Plasmodium, Cryptosporidium, and Hepatozoon form a monophyletic group distinct
from representatives of other apicomplexan families. Although equivocal, our
analysis indicated that Plasmodium and Cryptosporidium are sister taxa and that
Hepatozoon is basal to them. To evaluate phylogenetic affinities among H.
americanum, H. canis, and other species of Hepatozoon, we examined 18 morphologic
and life-cycle features of 13 species currently assigned to Hepatozoon. This
analysis indicates paraphyly of Hepatozoon (as currently arranged) because
Hepatozoon lygosomarum was found most closely related to Hemolivia mauritanicum.
These results, combined with results of previous studies, support elevating
Hepatozoon to familial level (Hepatozoidae) as originally suggested by Wenyon in
1926. Both DNA sequence data and morphologic and life-cycle characters support a
sister-group relationship between H. americanum and H. canis.
PMID- 10780560
TI - Six new species of coccidia (Apicomplexa: Eimeriidae) from East African
chameleons (Sauria: Chamaeleonidae).
AB - Coprological examination of 83 East African chameleon specimens revealed 32.5%
prevalence of coccidian parasites. Six species are described as new: Eimeria
tilburyi n. sp. from Chamaeleo jacksonii has cylindrical oocysts, 28.9 (26-33) x
16.0 (14-18) microm and occasionally a small polar granule. Sporocysts are oval
to ellipsoidal, 10.6 (9-12) x 7.2 (6-8) microm, without Stieda and substieda
bodies; endogenous stages were found in the gall bladder. Oocysts of Eimeria
largeni n. sp. from Chamaeleo gracilis are broadly cylindrical, 31.2 (29.5-34) x
19.3 (18.5-20) microm, with 1-3 polar granules. Sporocysts are oval, 10.2 (10-11)
x 7.6 (7-8.5) microm, without Stieda and substieda bodies. Eimeria bohemii n. sp.
from Chamaeleo melleri has cylindrical oocysts, 25.0 (24-26) x 14.0 (13-15)
microm, without a polar granule. Sporocysts are broadly oval, 9.4 (9-10) x 6.5 (6
7) microm, without Stieda and substieda bodies. Isospora wildi n. sp. from
Chamaeleo dilepis has subspherical to broadly oval oocysts, 25 (22-28) x 21.4 (18
24) microm, with a smooth wall 1 microm thick. Sporocysts are broadly oval to
ellipsoidal, 12.3 (12-13) x 9.7 (9-10) microm, with Stieda and substieda bodies.
Oocysts of Isospora necasi n. sp. from C. melleri are subspherical to broadly
oval, 26.6 (21-30) x 24.3 (20-27) microm, with a velvetlike wall 2 microm thick.
Sporocysts are broadly ellipsoidal, 12.8 (12-14) x 9.8 (9-10) microm, with
slightly pointed end and with Stieda and substieda bodies. Oocysts of Isospora
munriyu n. sp. from C. jacksonii are spherical to subspherical, 23.6 (21.5-25) x
21.9 (21-23) microm, with a finely granulated wall 1.5 microm thick. Sporocysts
are broadly ellipsoidal, 12.4 (12-13) X 8.7 (8-10) microm, with Stieda and
substieda bodies.
PMID- 10780561
TI - Phylogeny of the Ascaridoidea (Nematoda: Ascaridida) based on three genes and
morphology: hypotheses of structural and sequence evolution.
AB - Ascaridoid nematodes parasitize the gastrointestinal tract of vertebrate
definitive hosts and are represented by more than 50 described genera. We used
582 nucleotides (83% of the coding sequence) of the mitochondrial gene cytochrome
oxidase subunit 2, in combination with published small- and large-subunit nuclear
rDNA sequences (2,557 characters) and morphological data (20 characters), to
produce a phylogenetic hypothesis for representatives of this superfamily. This
combined evidence phylogeny strongly supported clades that, with 1 exception,
were consistent with Fagerholm's 1991 classification. Parsimony mapping of
character states on the combined evidence tree was used to develop hypotheses for
the evolution of morphological, life history, and amino acid characters. This
analysis of character evolution revealed that certain key features that have been
used by previous workers for developing taxonomic and evolutionary hypotheses
represent plesiomorphic states. Cytochrome oxidase subunit 2 nucleotides show a
strong compositional bias to A+T and a substitution bias to thymine. These biases
are most apparent at third positions of codons and 4-fold degenerate sites, which
is consistent with the nonrandom substitution pattern of A+T pressure. Despite
nucleotide bias, cytochrome oxidase amino acid sequences show conservation and
retention of critical functional residues, as inferred from comparisons to other
organisms.
PMID- 10780562
TI - Two malaria parasites (Apicomplexa: Plasmodiidae) of the Australian skink Egernia
stokesii.
AB - The Australian skink Egernia stokesii is parasitized uncommonly by Plasmodium
circularis n. sp. and by Plasmodium mackerrasae. Plasmodium circularis is
distinguished from all other plasmodiids by immature schizonts that encircle host
cell nuclei, forming an unbroken ring from apparent fusion of the attenuated
ends. Mature schizonts contract into halteridial or dumbbell-shaped forms 15.6 x
4.3 microm, LW 66.2 microm2, with 19-52 nuclei. Rounded or oval gametocytes are
9.0 x 7.3 microm, LW 66.9 microm2, and L/W 1.24. Gametocyte LW is 2.63 x host
erythrocyte nucleus size and 1.79X uninfected erythrocyte nuclei. Plasmodium
mackerrasae occurs in high prevalence and often massive parasitemia in E.
stokesii. Schizonts, often oblong, elongate, or oval, are 5.1 x 3.7 microm, LW
19.8 microm2, with 7.2 merozoites. Immature gametocytes, elongate with terminal
nucleus, may produce multiple infections of 6 or more parasites. Mature
gametocytes, usually rounded, are 5.8 x 4.6 microm, LW 26.7 microm2, and L/W
1.29. Gametocyte size is 0.98 x host erythrocyte nucleus size and 1.03 x
uninfected erythrocyte nuclei. Phanerozoites, in endothelium or connective tissue
of most organs, may appear in large numbers in circulating blood as seemingly
intact bodies of regular form, similar to or larger than phanerozoites seen in
sections. Previously unreported phenomena for hemosporidian parasites include
extremely large, highly irregular exoerythrocytic schizonts, in circulating
blood, perhaps torn from endothelial lining of blood vessels and sinuses, and a
visible flooding of free merozoites into the blood stream.
PMID- 10780563
TI - The sesquiterpene lactone dehydroleucodine (DhL) affects the growth of cultured
epimastigotes of Trypanosoma cruzi.
AB - Here, we report an inhibitory effect of a sesquiterpene lactone dehydroleucodine
(DhL) on the growth of Trypanosoma cruzi in culture. At concentrations of the
drug between 5 and 10 microg/ml in the medium,the parasites remained alive for at
least 4 days. Higher concentrations of DhL were lethal for the parasites within a
few hours. The effect of DhL is irreversible. Morphological changes induced by
DhL were also observed in the parasites. The effect of DhL was blocked by the
presence of reducing substrates such as glutathione or dithiothreitol, but these
agents were not able to reverse the effect of DhL if added 2 days after the start
of drug exposure.
PMID- 10780564
TI - Cryptosporidium serpentis oocysts and microsporidian spores in feces of captive
snakes.
AB - Fecal smears of 90 snakes, 29 lizards, and 8 turtles and tortoises were tested
for Cryptosporidium spp. oocysts and microsporidian spores. Microsporidian spores
measured mean = 3.7 microm in length and mean = 2.3 microm in width and were
present in feces of 19 snakes and 1 lizard (16%); 13 of these snakes also shed
Cryptosporidium serpentis oocysts. The oocysts were numerous in all positive
samples, whereas microsporidian spores were always sparse, irrespective if
whether fecal samples contained the oocysts. Retrospective examination of reptile
clinical records revealed that all animals shedding microsporidian spores died
naturally due to diseases, pathologic conditions, and clinical problems or were
killed due to severe cryptosporidiosis. The present study indicates that
microsporidian infections in reptiles have the features of an opportunistic
infection.
PMID- 10780565
TI - Survival and distribution of Echinostoma caproni in the small intestine of ICR
mice up to 36 hours after the death of the host.
AB - This study examined survival and distribution of Echinostoma caproni in the small
intestine of ICR mice at various times up to 36 hr following the death of the
host. Adult worms were obtained at 2-wk postinfection of 21 ICR mice each
infected with 50 metacercarial cysts. Mice were killed with light ether
anesthetization and cervical dislocation and maintained at room temperature (22
+/- 1C) until examination at 0 (controls), 2, 4, 6, 12, 24, and 36 hr postmortem.
Survival was based on worm activity and distribution was assessed on the basis of
worm location in 1 of 5 equal intestinal segments numbered from the pylorus to
the ileocecal valve. Worms were alive up to 36 hr post-mortem and were
distributed mainly in segments 3 and 4 at all times postmortem. Histochemical Oil
Red O studies on whole control and experimental worms showed neutral lipids
localized in the protone-phridial tubules and the excretory bladder. Eggs from
experimental worms at all times produced miracidia that infected Biomphlaria
glabrata snails.
PMID- 10780566
TI - Host death: a necessary condition for the transmission of Aphalloides coelomicola
Dollfus, Chabaud, and Golvan, 1957 (Digenea, Cryptogonimidae)?
AB - Eggs of the trematode Aphalloides coelomicola were observed free in the abdominal
cavity of Pomatoschistus microps from March 1993 to October 1995 (Pisces,
Gobiidae) in the Vaccares lagoon (delta du Rhone, France). The eggs were
contained in a fine membrane of parasitic origin as no immunological reaction of
the fish was noted. The alternatively high prevalence of adults and low
prevalence of free eggs, and vice versa, suggest that P. microps is both the
second intermediate and final hosts of the trematode Aphalloides coelomicola and
that the mechanism of transfer to the first intermediate host is through death of
the definitive host.
PMID- 10780567
TI - The palearctic oystercatcher Haematopus ostralegus, a natural definitive host for
Gymnophalloides seoi.
AB - In order to verify the role of migrating birds as natural definitive hosts for
Gymnophalloides seoi (Gymnophallidae), Palearctic oystercatchers, Haematopus
ostralegus, were caught from several western coastal areas in the Republic of
Korea and examined for intestinal flukes. Five (71.4%) of 7 oystercatchers were
infected with 302-1,660 (mean 892) adult G. seoi. In intestinal sections of the
host, worms were found in the intervillous space of the mucosal layer. We
conclude that the oystercatcher is a natural definitive host for G. seoi.
PMID- 10780568
TI - Defining GERD.
AB - "It is not the death of GERD that I seek, but that it turns from its evil ways
and follows the path of righteousness." The reflux world is fully aware of what
GERD is and what GERD does. What the world does not know, however, is the answer
to the most important yet least asked question surrounding GERD's raison-d'etre:
Why is GERD here and why do we have it? What GERD is: abnormal gastric reflux
into the esophagus that causes any type of mischief. What GERD does: causes
discomfort and/or pain with or without destroying the mucosa; causes stricture or
stenosis, preventing food from being swallowed; sets the stage for the
development of esophageal adenocarcinoma; invades the surrounding lands to harass
the peaceful oropharyngeal, laryngeal and broncho-pulmonary territories; reminds
us that we are not only human, but that we are dust and ashes. Why GERD is here:
We propose three separate and distinct etiologies of GERD, and we offer the
following three hypotheses to explain why, after 1.5 million years of standing
erect, we have evolved into a species (specifically Homosapiens sapiens) that is
destined to live with the scourge of GERD. Hypothesis 1: congenital. The
antireflux barrier, comprising the smooth-muscled lower esophageal sphincter, the
skeletal-muscled right crural diaphragm and the phreno-esophageal ligament does
not completely develop due to a developmental anomaly or incomplete gestation.
Hypothesis 2: acute trauma: The antireflux barrier in adults suffering acute
traumatic injury to the abdomen or chest is permanently disrupted by unexpected
forces, such as motor vehicle accidents (with steering wheel crush impact), blows
to the abdomen (from activities such as boxing, etc.), heavy lifting or moving
(e.g., pianos, refrigerators) or stress positions (e.g., hand stands on parallel
gym bars). The trauma creates a hiatal hernia that renders the antireflux
mechanism useless and incapable of preventing GERD. Hypothesis 3: chronic trauma:
The antireflux barrier in children and adults is gradually weakened over time as
a result of chronic straining to defecate and straining in an unphysiologic
position, both of which stem from our modern day habits of eating a low-fiber
diet and living on the high-seated toilet. We suggest that the chronic traumatic
hiatal hernia is (a) the cause of more than 90 percent of the GERD that stalks
the Western world; (b) is a direct result of abandoning the popular and worldwide
practice of squatting to socialize, eat and defecate; and (c) is our just reward
for adopting the "civilized" high sitting position on chairs and modern toilets.
PMID- 10780569
TI - Clinical epidemiology and natural history of gastroesophageal reflux disease.
AB - In the MUSE classification of gastroesophageal reflux disease (GERD), esophagitis
is assessed by the presence of metaplasia, ulcer, stricture, or erosion, each
being graded as absent, mild or severe. Daily reflux symptoms affect about 4 to 7
percent of the population; erosive esophagitis occurs in about 2 percent; the
prevalence rate of Barrett's metaplasia is 0.4 percent; and esophageal
adenocarcinoma leads to two deaths per million living population. In persons with
GERD symptoms, about 20 percent are found to have erosive esophagitis, while
ulcers or strictures are found in less than 5 percent of all patients with
erosive esophagitis. No clear-cut temporal progression exists between successive
grades of disease severity, as the most severe grade of GERD is reached at the
onset of the disease. Mild forms of GERD tend to be more common in women than
men, while severe GERD characterized by erosive esophagitis, esophageal ulcer,
stricture or Barrett's metaplasia are far more common in men than women. All
forms of GERD affect Caucasians more often than African Americans or Native
Americans. The prevalence of GERD is high among developed countries in North
America and Europe and relatively low in developing countries in Africa and Asia.
During the past three decades, hospital discharges and mortality rates of gastric
cancer, gastric ulcer and duodenal ulcer have declined, while those of esophageal
adenocarcinoma and GERD have markedly risen. These opposing time trends suggest
that corpus gastritis secondary to Helicobacter pylori infection protects against
GERD. This hypothesis is consistent with the geographic and ethnic distributions
of GERD. Case-control studies also indicate that cases with erosive esophagitis
are less likely to harbor active or chronic corpus gastritis than controls
without esophagitis.
PMID- 10780570
TI - Endoscopic evaluation of gastro-esophageal reflux disease.
AB - Endoscopy is, currently, the initial investigation of choice for the
investigation of gastroesophageal reflux disease (GERD) in clinical practice and
clinical research. Erosion severity is predictive of a patient's response to
therapy and of the likelihood of relapse after therapy. It is, therefore,
important to grade the severity of erosive reflux esophagitis, particularly in
the context of clinical trials. The Savary-Miller endoscopic classification
system is used widely but usage and interpretation are very variable. The "MUSE"
(metaplasia [M], ulceration [U], stricturing [S] and erosions [E]) classification
provides clear definitions of the relevant endoscopic features, and it is based
on a standardized report form, which allows the endoscopist to make a clear
record of esophagitis severity. Recent studies confirm that endoscopists can
identify erosions or mucosal breaks, ulcers, strictures, and metaplasia
reproducibly. The "L.A." (Los Angeles) classification describes four grades of
esophagitis severity (A to D), based on the extent of esophageal lesions known as
"mucosal breaks," but it does not record the presence or severity of other GERD
lesions. Thus, for patients with "complicated" reflux disease, the "MUSE"
classification offers a more comprehensive description of esophagitis severity.
Endoscopy is not universally applicable: 40 to 60 percent of patients with
typical reflux symptoms do not have esophageal erosions and are now considered to
have "endoscopy negative reflux disease" (ENRD). Thus, endoscopy is not the final
arbiter as to a diagnosis of reflux disease, and it is not, therefore, a
necessary prerequisite to therapy. Endoscopy is indicated at first presentation
for patients with alarm symptoms referable to the upper gastrointestinal tract.
It has also been proposed that all patients with chronic GERD should have a "once
in-a-lifetime" endoscopy; in the absence of Barrett's esophagus or other
complications, no follow-up is required unless the patient's symptoms change
significantly. A surveillance program with multiple biopsies should be instituted
if there is evidence of Barrett's esophagus. Endoscopic evaluation should
document the presence and extent of esophageal erosions using the L.A. or MUSE
classification systems; complications should also be documented and may be
recorded using the MUSE classification. Non-erosive changes such as erythema may
be ignored on the basis of present evidence, and there are no clear data to
support the use of endoscopic biopsies for the diagnosis of GERD.
PMID- 10780571
TI - The role of hiatus hernia in GERD.
AB - Increased esophageal acid exposure in gastroesophageal reflux disease has several
potential causes, some related primarily to physiological dysfunction of the LES
and others related to anatomic distortion of the gastroesophageal junction as
occurs with hiatus hernia. One attractive feature of implicating hiatal hernias
in the pathogenesis of reflux disease is that, like reflux disease, axial hernias
become more common with age and obesity. However, the importance of hiatus hernia
is obscured by imprecise definition and an all-or-none conceptualization that has
led to wide variation in estimates of prevalence among normal or diseased
populations. There are at least three potentially significant radiographic
features of a hiatus hernia: axial length during distention, axial length at
rest, and competence of the diaphragmatic hiatus. Although any or all of these
features may be abnormal in a particular instance of hiatus hernia, each is of
different functional significance. Grouping all abnormalities of the
gastroesophageal junction as "hiatus hernia" without detailing the specifics of
each case defies logic. Mechanistically, the gastroesophageal junction must
protect against reflux both in static and dynamic conditions. During abrupt
increases in intra-abdominal pressure, the crural diaphragm normally serves as a
"second sphincter," and this mechanism is substantially impaired in individuals
with a gaping hiatus. Large, non-reducing hernias also impair the process of
esophageal emptying, thereby prolonging acid clearance time following a reflux
event (especially while in the supine posture). These anatomically-determined
functional impairments of the gastroesophageal junction lead to increased
esophageal acid exposure. Thus, although hiatus hernia may or may not be an
initiating factor at the inception of reflux disease, it clearly can act as a
sustaining factor accounting for the frequently observed chronicity of the
disease.
PMID- 10780573
TI - Epithelial lineage and transformation.
PMID- 10780572
TI - Rab11 in dysplasia of Barrett's epithelia.
AB - Barrett's esophagus predisposes affected patients to the development of
esophageal adenocarcinoma. The development of adenocarcinoma proceeds along a
progression through low- and high-grade dysplasia. Surveillance of Barrett's
patients requires serial endoscopic investigations and grading mucosal biopsies.
Unfortunately, grading of biopsies by conventional hematoxylin and eosin staining
is fraught with significant interobserver variations. We have found in both
biopsy and resection specimens that immunostaining for the small GTP binding
protein Rab11 is increased in low-grade dysplastic cells. This staining is lost
in high-grade dysplastic cells. These results suggest that low-grade dysplastic
cells undergo an apical trafficking blockade, which is released as cells progress
to the less differentiated phenotype of high-grade dysplasia and adenocarcinoma.
Examination of the SKGT-4 esophageal adenocarcinoma cell line demonstrated
prominent mRNA and protein expression for Rab11. Rab11 immunostaining was present
in SKGT-4 cells as a perinuclear nidus of punctate staining along with a more
diffuse punctate pattern. Thus, Rab11 expression was present in a esophageal
adenocarcinoma cells in culture. Markers of vesicle trafficking may be critical
factors for grading of mucosal dysplastic transitions leading to adenocarcinoma.
PMID- 10780574
TI - Acid and the esophagus.
PMID- 10780575
TI - Pepsin and the esophagus.
AB - Esophagitis results from excessive exposure of the esophagus to gastric juice
through an ineffective or dysfunctional lower esophageal sphincter mechanism. A
possible role of pepsin in damaging the esophageal mucosa with consequent
esophagitis may be examined directly by testing pepsin under various conditions
in experimental models of esophagitis. Since gastric juice contains both acid and
pepsin, all experiments examine separately effects of perfusion of the esophagus
by acid without and with pepsin in various combinations. Acid perfusion alone at
concentrations represented by pH 1.3 or above does not produce esophagitis. The
addition of pepsin to acid between pH 1 and 3.5 causes considerable acute
esophageal damage. Outside the proteolytic range, i.e., higher than pH 3.5,
pepsin does not damage the esophagus. The damage caused by acidified pepsin may
be made much worse by the further addition of aspirin or other NSAIDs, presumably
by further breaking down mucosal barriers.
PMID- 10780576
TI - Helicobacter pylori and dyspepsia.
AB - It is clear that non-ulcer (or functional) dyspepsia is a heterogeneous syndrome
that includes a subset of patients with unrecognized gastroesophageal reflux.
Patient heterogeneity combined with inadequate study methodology has led to
enormous confusion in interpreting the relationship between Helicobacter pylori
and non-ulcer dyspepsia. The possibility that H. pylori is associated with
gastroesophageal reflux disease may explain, in part, the difficulty in
establishing a link between non-ulcer dyspepsia and H. pylori infection. It is
unclear whether the prevalence of H. pylori is increased in non-ulcer dyspepsia
over and above the background population. H. pylori does not appear to be linked
to heartburn or other specific upper gastrointestinal tract symptoms. The results
of eradication trials in H. pylori-infected patients with non-ulcer dyspepsia
have been equivocal and generally flawed. There is no doubt that H. pylori is not
a sufficient cause of non-ulcer dyspepsia, because it is well documented in the
literature that dyspepsia can occur in the absence of infection and infection can
occur in the absence of symptoms. At this stage, there is insufficient evidence
to support the hypothesis that H. pylori is etiologically linked to non-ulcer
dyspepsia, but data from well designed large randomized controlled trials of
eradication therapy, are awaited with great interest.
PMID- 10780578
TI - Drugs, bugs, and esophageal pH profiles.
AB - Until relatively recently, gastroesophageal reflux disease (GERD) was thought to
be a relatively trivial problem, and pharmaceutical companies initially had
remarkably little interest in clinical trials for GERD. Over the last ten years,
GERD therapy has become the subject of intense interest, since reflux disease is
now recognized as a major market for antisecretory and prokinetic drugs. Even low
technology antacids are now known to effectively neutralize esophageal acid
prevent acid reflux for up to 90 minutes. Esophageal pH profiling is known to be
an excellent surrogate for clinical efficacy of GERD drugs, particularly in
erosive esophagitis. Years ago, famotidine normalized esophageal mucosal exposure
to pH < 4.0 only when administered in doses of 40 mg twice a day. Subsequent
studies confirmed that multiple daily dosing of histamine-2 receptor antagonists
(H2RAs) was mandatory for GERD treatment, with clear dose-response relationships
for each agent. Proton pump inhibitors (PPIs) have each been carefully assessed
in terms esophageal and gastric pH profiles. Omeprazole has a particularly flat
dose response curve, making it difficult to differentiate pH or clinical effects
of 20 vs. 40 mg doses. Improved rapidity of onset and/or enhanced potency is
demonstrable in pH data obtained with lansoprazole, rabeprazole and pantoprazole.
Such differences will translate to improved clinical efficacy, based on the meta
analyses of Richard Hunt and his group in Canada that correlate pH effects and
symptom relief/healing. PPI's have dependably surpassed H2RAs and prokinetic
drugs in management of the more severe grades of esophagitis. Helicobacter pylori
has a peculiar relationship to GERD. There has been some concern that PPIs given
to patients with H. pylori might accelerate development of severe atrophic
gastritis. It is also now known that eradication of H. pylori may increase
symptomatic GERD (possibly as a result of increased gastric acid secretion once
the bacteria have been eliminated). New data confirm nocturnal breakthrough of
acid secretion and esophageal acid exposure in three-fourths of patients on
omeprazole 20 mg twice daily. This nocturnal acidity can be controlled more
effectively with a nighttime dose of an H2RA than with a third dose of
omeprazole. Control of acid secretion and improved gastric and esophageal pH
profiles are goals of modern GERD therapy, and the product that most cost
effectively normalizes esophageal acid exposure will have a substantial advantage
in the ever-growing GERD marketplace.
PMID- 10780577
TI - Signal transduction in esophageal and LES circular muscle contraction.
AB - Contraction of normal esophageal circular muscle (ESO) in response to
acetylcholine (ACh) is linked to M2 muscarinic receptors activating at least
three intracellular phospholipases, i.e., phosphatidylcholine-specific
phospholipase C (PC-PLC), phospholipase D (PLD), and the high molecular weight
(85 kDa) cytosolic phospholipase A2 (cPLA2) to induce phosphatidylcholine (PC)
metabolism, production of diacylglycerol (DAG) and arachidonic acid (AA),
resulting in activation of a protein kinase C (PKC)-dependent pathway. In
contrast, lower esophageal sphincter (LES) contraction induced by maximally
effective doses of ACh is mediated by muscarinic M3 receptors, linked to
pertussis toxin-insensitive GTP-binding proteins of the G(q/11) type. They
activate phospholipase C, which hydrolyzes phosphatidylinositol bisphosphate
(PIP2), producing inositol 1,4,5-trisphosphate (IP3) and DAG. IP3 causes release
of intracellular Ca++ and formation of a Ca++-calmodulin complex, resulting in
activation of myosin light chain kinase and contraction through a calmodulin
dependent pathway. Signal transduction pathways responsible for maintenance of
LES tone are quite distinct from those activated during contraction in response
to maximally effective doses of agonists (e.g., ACh). Resting LES tone is
associated with activity of a low molecular weight (approximately 14 kDa)
pancreatic-like (group 1) secreted phospholipase A2 (sPLA2) and production of
arachidonic acid (AA), which is metabolized to prostaglandins and thromboxanes.
These AA metabolites act on receptors linked to G-proteins to induce activation
of PI- and PC-specific phospholipases, and production of second messengers.
Resting LES tone is associated with submaximal PI hydrolysis resulting in
submaximal levels of inositol trisphosphate (IP3-induced Ca++ release, and
interaction with DAG to activate PKC. In an animal model of acute esophagitis,
acid-induced inflammation alters the contractile pathway of ESO and LES. In LES
circular muscle, after induction of experimental esophagitis, basal levels of PI
hydrolysis are substantially reduced and intracellular Ca++ stores are
functionally damaged, resulting in a reduction of resting tone. The reduction in
intracellular Ca++ release causes a switch in the signal transduction pathway
mediating contraction in response to ACh. In the normal LES, ACh causes release
of Ca++ from intracellular stores and activation of a calmodulin-dependent
pathway. After esophagitis, ACh-induced contraction depends on influx of
extracellular Ca++, which is insufficient to activate calmodulin, and contraction
is mediated by a PKC-dependent pathway. These changes are reproduced in normal
LES cells by thapsigargin-induced depletion of Ca++ stores, suggesting that the
amount of Ca++ available for release from intracellular stores defines the signal
transduction pathway activated by a maximally effective dose of ACh.
PMID- 10780579
TI - Pharmacologic modulation of motility.
AB - Etiologically, gastroesophageal reflux disease (GERD) can be regarded as motility
disorder: Although blocking acid is effective in the treatment of GERD, it does
not overcome the underlying pathologic factors that allow acid, pepsin, and bile
to reflux into the esophagus. Prokinetic agents address the upper
gastrointestinal motility disturbances contributing to GERD and, thus, have an
important role in the short- and long-term medical management of reflux
esophagitis. This paper discusses the rationale for the effectiveness of
pharmacologic modulation by reviewing current concepts and postulated theories
about the mechanisms underlying the neuromuscular abnormalities. The
multifactorial aspects of GERD are addressed and the potential for tailoring
medical therapy also emphasized.
PMID- 10780581
TI - Helicobacter pylori modulation of gastric acid.
AB - Helicobacter pylori plays major causative roles in peptic ulcer disease and
gastric cancer. Elevated acid secretion in patients with duodenal ulcers (DUs)
contributes to duodenal injury, and diminished acid secretion in patients with
gastric cancer allows carcinogen-producing bacteria to colonize the stomach.
Eradication of H. pylori normalizes acid secretion both in hyper-secreting DU
patients and hypo-secreting relatives of gastric cancer patients. Therefore, we
and others have asked how H. pylori causes these disparate changes in acid
secretion. H. pylori gastritis more or less restricted to the gastric antrum in
DU patients is associated with increased acid secretion. This is probably because
gastritis increases release of the antral acid-stimulating hormone gastrin and
diminished mucosal expression of the inhibitory peptide somatostatin. Bacterial
products and inflammatory cytokines including TNFalpha may cause these changes in
endocrine function. Gastritis involving the gastric corpus tends to diminish acid
secretion, probably because bacterial products and cytokines including IL-1
inhibit parietal cells. Pharmacological inhibition of acid secretion increases
corpus gastritis in H. pylori-infected subjects, so it is envisaged that gastric
hypo-secretion of any cause might become self-perpetuating. H. pylori-associated
mucosal atrophy will also contribute to acid hypo-secretion and is more likely in
when the diet is high in salt or lacking in antioxidant vitamins. Data on gastric
acid secretion in patients with esophagitis are limited but suggest that acid
secretion is normal or slightly diminished. Nevertheless, H. pylori infection may
be relevant to the management of esophagitis because: (i) H. pylori infection
increases the pH-elevating effect of acid inhibiting drugs; (ii) proton pump
inhibitors may increase the tendency of H. pylori to cause atrophic gastritis;
and (iii) successful eradication of H. pylori is reported to increase the
likelihood of esophagitis developing in patients who had DU disease. Points (ii)
and (iii) remain controversial and more work is clearly required to elucidate the
relationship between H. pylori, acid secretion, gastric mucosa atrophy and
esophagitis.
PMID- 10780582
TI - Management of gastroesophageal reflux disease: the primary care strategy.
AB - Gastroesophageal reflux disease (GERD) is a common problem in the community and
in general practice. General practitioners and family physicians need to
understand patients' reasons for consultation and also be aware of alarm symptoms
suggestive of serious disease. A primary care management strategy for GERD is
proposed, in which the place of endoscopic and other investigations is defined,
the role of lifestyle modification discussed, and recommendations for longer-term
therapy and management are made.
PMID- 10780580
TI - pH, healing rate, and symptom relief in patients with GERD.
AB - Gastroesophageal reflux symptoms are common and occur in all of us from time to
time. In others, reflux may be associated with ulcerative esophagitis. The
symptoms may be aggravated by large meals, coffee, smoking and position.
Physiological and pathological reflux can be separated by the frequency and
duration of the exposure of the lower esophagus to acid. Pathological reflux
results in symptoms and also esophagitis and ulceration in some patients.
Although gastroesophageal reflux disease (GERD) is considered to result from a
disorder of motility in the esophagus, gastric acid and peptic activity are
deemed pivotal to the initiation and continuation of the esophageal damage and
the development of symptoms. Acid exposure in the esophagus is normally less than
4 percent of the 24 hours with a pH below 4. An increase over 4 percent of the
time with a pH less than 4 is considered pathological. Hence, antisecretory drugs
have become the principle approach to the treatment of reflux symptoms and
esophagitis since they reduce the acidity, of gastric juice and the activity of
pepsin. Importantly, they also reduce the volume of gastric juice available for
reflux into the esophagus. There is a clear relationship between the degree and
duration of acid suppression and the relief of heartburn and healing of
esophagitis. Pharmacodynamic studies with different dose regimens of the H2
receptor antagonists and the proton pump inhibitors show a difference in the
degree and duration of the antisecretory effect, and this correlates closely with
the results of clinical trials with respect to the healing of esophagitis and the
relief of symptoms. Proton pump inhibitors achieve healing rates by week four,
which are not achieved by H2-receptor antagonists even after 12 weeks of
treatment. The advantage of proton pump inhibitors over H2-receptor antagonists
is due to the greater degree, longer duration of effect and more complete
inhibition of acid secretion that maintains intragastric pH above 4 for a maximal
duration. Although there is no significant difference between proton pump
inhibitors with respect to healing of esophagitis, symptom relief occurs earlier
with lansoprazole than omeprazole, and this is probably due to the greater oral
bioavailability and faster onset of action of lansoprazole when compared to
omeprazole.
PMID- 10780583
TI - Helicobacter pylori, proton pump inhibitors and gastroesophageal reflux disease.
AB - Proton pump inhibitors have become of pivotal importance for the treatment of
GERD. The purpose of this paper is to review the interaction between Helicobacter
pylori and PPIs in the treatment of GERD. H. pylori exaggerates the acid
suppressive effects of PPIs. During treatment with these drugs, H. pylori
positive subjects thus have a higher intragastric pH than H. pylori-negative
subjects. The mechanism for this phenomenon remains to be elucidated. We
hypothesize that it is related to H. pylori-induced corpus gastritis, which
impairs parietal cell function. The available evidence suggests that this
phenomenon has no clinical relevance for the treatment of GERD. The 24-hr
esophageal pH during PPI treatment does not depend on the H. pylori status, nor
does the medication dose needed for maintenance therapy or the number of clinical
relapses during such therapy depend on the H. pylori status. PPIs, on the other
hand, also affect H. pylori. During treatment with these drugs, the pattern of
bacterial colonization and associated gastritis shifts proximally. The increased
gastritis of the body mucosa is associated with a more rapid development of
atrophic gastritis, a condition characterized by a loss of gastric glands and
associated with an increased cancer risk. For these reasons, one has to consider
H. pylori eradication in infected GERD patients in need of PPI maintenance
therapy.
PMID- 10780584
TI - Medical therapy of gastroesophageal reflux disease in secondary and tertiary care
settings.
AB - Gastroesophageal reflux disease (GERD) is common. Many patients with recurring or
troublesome symptoms are referred for endoscopic examination. Patients seen in
secondary care usually have failed OTC or primary care anti-reflux therapy. Acid
suppression is the mainstay of healing and maintenance therapy. Increasingly
proton pump inhibitors (PPIs) are preferred above H2 receptor antagonists
(H2RAs), not only for the more severe end of the GERD spectrum but also for
patients with mild degrees of esophagitis. Not all patients respond
symptomatically to acid suppression, not even with high dose PPI. Prokinetics are
mainly useful in the milder degrees of GERD. It is still not clear whether a
particular symptom cluster can be recognized for which prokinetics are especially
useful. The concept of "step-up versus step-down" approach remains in need for
proper validation. Switching from PPIs to cisapride for "step-down" maintenance
appears inadequate in practice. All current therapies have shortcomings; H2RAs
insufficiently block meal-stimulated acid secretion; long-term strong acid
suppression worsens Helicobacter pylori-associated inflammation in the corpus and
may accelerate development of atrophy; PPI-potency is substantially weaker in non
H. pylori infected individuals. Optimization of individualized therapy will
require more potent and more precisely targeted motility modulating drugs and
superior acid/peptic inhibiting pharmaceuticals.
PMID- 10780585
TI - Acid inhibition and gastroesophageal reflux disease.
PMID- 10780586
TI - The effect of surgery on pressure and motility.
PMID- 10780587
TI - Elderly injury: a profile of trauma experience in the Sunshine (Retirement)
State.
AB - OBJECTIVE: By using mandatory discharge data from a state agency, the records of
116,687 patients hospitalized for treatment of injury were evaluated to develop
an epidemiologic and demographic profile of this population and to compare
outcomes of patients treated in state-designated trauma centers (TC) with those
treated in nontrauma centers (NTC). METHODS: Injury severity was calculated by
using the International Classification Injury Severity Score methodology to
compute individual diagnosis survival risk ratios from 698,187 reported
diagnoses, and then by using these survival risk ratios to determine probability
of survival for every patient. The population was then categorized by age, injury
type, treatment facility designation, injury severity as indicated by probability
of survival, and discharge disposition. Incidence of potentially preventable
death was compared between TC and NTC, as was the effect on outcome of noninjury
comorbidity. RESULTS: The average age of this population was 58 +/- 26 years with
significant skew toward the elderly in NTC (mean age, 62 +/- 26 years). The most
commonly encountered injuries likewise reflected the elderly nature of this
population. Although 71.3% received care in NTC, the majority of severely injured
were treated in TC. Potentially preventable mortality (>0.5) was significantly
lower in TC. The effect of noninjury comorbidity on outcome was better managed by
TC, both in terms of decreased mortality and in proportion of patients discharged
home. CONCLUSION: These data demonstrate the unique characteristics of injury
victims treated in the state of Florida and indicate that the developing trauma
system is demonstrating productivity in terms of avoidance of preventable death,
efficient management of noninjury comorbid problems, and more complete recovery
as indicated by proportion of patients discharged to home.
PMID- 10780588
TI - Factors affecting prognosis with penetrating wounds of the heart.
AB - OBJECTIVE: To determine factors affecting prognosis for patients with penetrating
wounds of the heart. METHODS: A retrospective review of 302 patients with
penetrating heart wounds undergoing emergency thoracotomy (August of 1980 through
June of 1997) in a Level I trauma center. RESULTS: There were 148 patients with
gunshot wounds (GSW) and 154 patients with stab wounds with 23% and 58% survival
rates, respectively. Of 43 patients having no signs of life at the scene, 5
patients (12%) achieved some cardiac activity and were brought to the operating
room (OR), but none survived. Of 67 patients "arresting" in the ambulance, 23 got
to the OR, but only 3 patients (4%) survived. Of 27 patients "arresting" in the
emergency department (ED), 18 patients reached the OR, but only 5 patients (19%)
survived. Of 15 patients having an ED thoracotomy because of rapid deterioration
there, 4 patients (27%) survived. Thus, of the 152 patients with an ED
thoracotomy, 93 patients had gunshot wounds and none survived; of the 59 with
stab wounds, 12 (20%) survived (p < 0.001). Of 150 patients having an OR
thoracotomy, 111 (74%) survived. Single-chamber injuries had a survival rate of
51% (112 of 219 patients), but multiple chamber and/or intrapericardial great
vessel injuries had only a 13% survival rate (11 of 83 patients) (p < 0.001).
Intrapericardial aortic injuries were uniformly fatal in 15 patients. In patients
with stab wounds, pericardial tamponade was associated with a higher survival
rate (66%; 56 of 84 patients) than in those without tamponade (47%; 33 of 70
patients). CONCLUSION: The physiologic status of the patient at presentation,
mechanism of injury, and presence of a tamponade were significant prognostic
factors in this series of penetrating cardiac injuries. Multiple-chamber
injuries, especially with great vessel involvement, were associated with a high
mortality rate. ED thoracotomies for gunshot wounds of the heart were uniformly
fatal.
PMID- 10780589
TI - Major trauma enhances store-operated calcium influx in human neutrophils.
AB - PURPOSE: Chemotaxins from inflammatory sites prime or activate neutrophils (PMN)
by using cytosolic calcium ([Ca2+]i) fluxes as second messengers. [Ca2+]i can be
mobilized rapidly by receptor-mediated entry or store-release, or more slowly by
store-operated calcium influx (SOCI). We studied [Ca2+]i mobilization by
chemotaxins and how trauma impacts the calcium entry mechanisms used by
chemotaxins. METHODS: [Ca2+]i flux was studied by spectrofluorometry. The
contributions of early and late [Ca2+]i currents to net calcium flux were
compared after stimulation by more potent (fMLP, C5a, PAF) or less potent (IL-8,
GRO-alpha, and LTB4) agonists. Store operated [Ca2+]i mobilization was reflected
by the ratio of area under the [Ca2+]i efflux curve to peak [Ca2+]i (efflux
curve). PMN from trauma patients (ISS > 25) and pair-matched volunteer (n = 7
pairs) were then primed and stimulated with thapsigargin to compare cell calcium
stores and SOCI. RESULTS: Late [Ca2+]i mobilization made more important
contributions to fMLP, PAF, and C5a signals than to IL-8, GRO-alpha, or LTB4 (p <
0.01 all comparisons). Calcium stores and store release were only marginally
lower after injury (p = not significant), but trauma PMN showed far higher
[Ca2+]i influx after thapsigargin (p = 0.007), and greater net SOCI (p = 0.034).
CONCLUSIONS: SOCI may play an important role in PMN activation, and trauma
increases PMN SOCI. Prolonged elevations of [Ca2+]i due to enhanced SOCI may
alter stimulus-response coupling to chemotaxins and contribute to PMN dysfunction
after injury.
PMID- 10780590
TI - Inhibition of neutrophil apoptosis after severe trauma is NFkappabeta dependent.
AB - BACKGROUND: Systemic inflammation may inhibit neutrophil (PMN) apoptosis and
promote multiple organ dysfunction syndrome. We hypothesize that severe trauma
causes dysregulation of PMN apoptosis. METHODS: Neutrophils were isolated from
trauma patients (24-72 hours after injury; n = 16) and controls (healthy
volunteers) and incubated for 18 hours. In separate experiments, control cells
were treated +/- the nuclear factor kappa beta (NFkappabeta) inhibitor
pyrrolidinithiocarbamate then incubated with 25% patient or control plasma.
Apoptosis was quantified by enzyme-linked immunosorbent assay for histone
associated DNA and annexin V fluorescence-activated cell sorter. NFkappabeta
activation was determined by Western blot for phosphorylated I kappabeta.
RESULTS: Apoptosis was inhibited in trauma patient PMN. Neutrophil apoptosis
correlated with multiple organ dysfunction syndrome score, Acute Physiology and
Chronic Health Evaluation II, and platelet count. Patient plasma inhibited
apoptosis and induced phosphorylation of I kappabeta in control cells. Inhibition
of PMN apoptosis by patient plasma was blocked by pretreatment with
pyrrolidinithiocarbamate. CONCLUSION: NFkappabeta-dependent inhibition of
neutrophil apoptosis occurs after trauma. Early inhibition of PMN apoptosis is
dependent on the magnitude of injury.
PMID- 10780591
TI - Age should not be a consideration for nonoperative management of blunt splenic
injury.
AB - BACKGROUND: Operative management of blunt splenic injury is recommended for
adults > or = 55 years. Because this is not our practice, we did a retrospective
review to compare outcomes of patients > or = 55 years old versus patients < 55
years old. METHODS: During a 5-year period ending in July of 1998, 461 patients
(3%) admitted to our Level I trauma center had a blunt splenic injury. Eighty-six
patients (19%) died within 24 hours of massive injuries, leaving 375 patients for
evaluation. Data were obtained from our trauma registry and medical records.
RESULTS: A total of 29 patients (8%) were > or = 55 years old (mean age, 67 +/- 2
years; mean injury severity score [ISS] 25 +/- 2). Of these, 18 patients (62%)
underwent nonoperative management (NOM). A total of 346 patients (92%) were < 55
years old (mean age, 28 +/- 0.6; mean ISS, 20 +/- 1). Of these, 198 patients
(57%) underwent NOM. The failure rate was not different between the two age
groups (17% vs. 14%). However, the ISS and mortality rate were significantly
higher in the older age group that failed (ISS, 29.3 +/- 2.6 vs. 19.5 +/- 2.1;
mortality: 67% vs. 4%). None of the deaths could be attributed to splenic injury.
CONCLUSION: Adults > or = 55 years old with blunt splenic injury are successfully
treated by NOM. Although older adults had significantly greater injuries, they
had similar failure rates of NOM when compared with younger adults. Older adults
had significantly higher mortality, but this was not a result of their splenic
injury. Therefore, age should not be a criteria for NOM of blunt splenic injury.
PMID- 10780592
TI - External fixation as a bridge to intramedullary nailing for patients with
multiple injuries and with femur fractures: damage control orthopedics.
AB - BACKGROUND: The advantages of early fracture fixation in patients with multiple
injuries have been challenged recently, particularly in patients with head
injury. External fixation (EF) has been used to stabilize pelvic fractures after
multiple injury. It potentially offers similar benefits to intramedullary nail
(IMN) in long-bone fractures and may obviate some of the risks. We report on the
use of EF as a temporary fracture fixation in a group of patients with multiple
injuries and with femoral shaft fractures. METHODS: Retrospective review of
charts and registry data of patients admitted to our Level 1 trauma center July
of 1995 to June of 1998. Forty-three patients initially treated with EF of the
femur were compared to 284 patients treated with primary IMN of the femur.
RESULTS: Patients treated with EF had more severe injuries with significantly
higher Injury Severity Scores (26.8 vs. 16.8) and required significantly more
fluid (11.9 vs. 6.2 liters) and blood (1.5 vs. 1.0 liters) in the initial 24
hours. Glasgow Coma Scale score was lower (p < 0.01) in those treated with EF (11
vs. 14.2). Twelve patients (28%) had head injuries severe enough to require
intracranial pressure monitoring. All 12 required therapy for intracranial
pressure control with mannitol (100%), barbiturates (75%), and/or
hyperventilation (75%). Most patients had more than one contraindication to IMN,
including head injury in 46% of cases, hemodynamic instability in 65%,
thoracoabdominal injuries in 51%, and/or other serious injuries in 46%, most
often multiple orthopedic injuries. Median operating room time for EF was 35
minutes with estimated blood loss of 90 mL. IMN was performed in 35 of 43
patients at a mean of 4.8 days after EF. Median operating room time for IMN was
135 minutes with an estimated blood loss of 400 mL. One patient died before IMN.
One other patient with a mangled extremity was treated with amputation after EF.
There was one complication of EF, i.e., bleeding around a pin site, which was
self-limited. Four patients in the EF group died, three from head injuries and
one from acute organ failure. No death was secondary to the fracture treatment
selected. One patient who had EF followed by IMN had bone infection and another
had acute hardware failure. CONCLUSION: EF is a viable alternative to attain
temporary rigid stabilization in patients with multiple injuries. It is rapid,
causes negligible blood loss, and can be followed by IMN when the patient is
stabilized. There were minimal orthopedic complications.
PMID- 10780593
TI - NISS predicts postinjury multiple organ failure better than the ISS.
AB - BACKGROUND: The Injury Severity Score (ISS) has been observed consistently to be
a robust predictor of postinjury multiple organ failure (MOF). However, the ISS
fails to account for multiple injuries to the same body region. Recently, the
"new" ISS (NISS) has been proposed to address this shortcoming. Preliminary
studies suggest the NISS is superior to the ISS in predicting trauma mortality.
Our purpose was to determine whether the NISS is a better predictor of postinjury
MOF than the ISS. METHODS: A total of 558 patients admitted to our Level I trauma
center with ISS > 15, age > 15 years, and survival > 48 hours were prospectively
identified; 101 (18%) developed postinjury MOF. Data characterizing postinjury
MOF were collected, and the NISS was calculated retrospectively. The ISS and NISS
were compared as univariate predictors of MOF. Multivariate analysis was used to
determine whether substitution of NISS for ISS resulted in a superior predictive
model. RESULTS: In 295 patients (53%), the NISS was greater than the ISS. This
subgroup of patients experienced a greater frequency of MOF (26.7% vs. 8.3%, p <
0.0001), a higher mortality (12.8% vs. 4.9%, p < 0.001), and a higher early
transfusion requirement (6.7 U vs. 3.6 U, p < 0.0001) compared with the group in
which NISS equaled ISS. Moreover, the NISS yielded better separation between
patients with and without MOF reflected by the greater difference in median NISS
scores compared with ISS scores. The multivariate predictive model, including
NISS, showed a better goodness of fit compared with the same model that included
ISS. CONCLUSIONS: The NISS is superior to the ISS in the prediction of postinjury
MOF. This measure of tissue injury severity should replace the ISS in trauma
research.
PMID- 10780594
TI - Using Trauma and Injury Severity Score (TRISS)-based analysis in the development
of regional risk adjustment tools to trend quality in a voluntary trauma system:
the experience of the Trauma Foundation of Northeast Ohio.
AB - BACKGROUND: Presently, no trauma system exists in Ohio. Since 1993, all hospitals
in Cuyahoga County (CUY), northeast Ohio (n = 22) provide data to a trauma
registry. In return, each received hospital-specific data, comparison data by
trauma care level and a county-wide aggregate summary. This report describes the
results of this approach in our region. METHODS: All cases were entered by paper
abstract or electronic download. Interrater reliability audits and z score
analysis was performed by using the Major Trauma Outcome Study and the CUY 1994
baseline groups. Risk adjustment of mortality data was performed using
statistical modeling and logistic regression (Trauma and Injury Severity Score,
Major Trauma Outcome Study, CUY). Trauma severity measures were defined. RESULTS:
In 1995, 3,375 patients were entered. Two hundred ninety-one died (8.6%).
Severity measures differed by level of trauma care, indicating differences in
case mix. Probability of survival was lowest in the Level I centers, highest in
the acute care hospitals. Outcomes z scores demonstrated survival differences for
all levels. CONCLUSIONS: In a functioning trauma system, the most severely
injured patients should be cared for at the trauma centers. A low volume at acute
care hospitals is desirable. By using Trauma and Injury Severity Score with
community-specific constants, NE Ohio is accomplishing these goals. The Level I
performance data are an interesting finding compared with the data from the Level
II centers in the region
PMID- 10780595
TI - Tissue hemoglobin O2 saturation during resuscitation of traumatic shock monitored
using near infrared spectrometry.
AB - BACKGROUND: Near infrared (NIR) spectrometry offers a noninvasive monitor of
tissue hemoglobin O2 saturation and has been developed to report a quantitative
clinical variable, StO2 [= HbO2/(HbO2 + Hb)]. In this study, a prototype NIR
oximeter was used to investigate the hypothesis that changes in systemic O2
delivery index (D(O2)I) would be reflected by changes in StO2 in skeletal muscle,
subcutaneous tissue, or both, as reperfusion occurs during shock resuscitation.
StO2 was also compared with other indices of severity of shock or adequacy of
resuscitation, including arterial base deficit, lactate, gastric mucosal P(CO2)
(PgCO2), and mixed venous hemoglobin O2 saturation (S(VO2)). METHODS: Skeletal
muscle and subcutaneous tissue StO2 were monitored simultaneously in eight
severely injured trauma patients (88% blunt mechanism; age, 42 +/- 6 years;
Injury Severity Score, 27 +/- 3) during standardized shock resuscitation in the
intensive care unit with the primary goal of D(O2)I > or = 600 mL O2/min/m2 for
24 hours, and for an additional 12 hours during transition from resuscitation to
standard intensive care unit care. RESULTS: Skeletal muscle StO2 increased
significantly from 15 +/- 2% (mean +/- SEM) at the start of resuscitation to 49
+/- 14% at 24 hours, and to approximately 55% from 25 to 36 hours. Subcutaneous
tissue StO2 approximately 82% and was significantly greater than skeletal muscle
StO2 throughout. D(O2)I increased significantly from 372 +/- 54 to 718 +/- 47 mL
O2/min/m2 during resuscitation. Over 36 hours, mean D(O2)I and skeletal muscle
StO2 were highly correlated (r = 0.95). Neither D(O2)I-PgCO2 nor D(O2)I-S(VO2)
were significantly correlated; neither S(VO2) nor subcutaneous tissue StO2
changed significantly. CONCLUSION: Hemoglobin O2 saturation was monitored
noninvasively and simultaneously in skeletal muscle and subcutaneous tissues as
StO2 (%) by using a prototype NIR oximeter. Skeletal muscle StO2 tracked systemic
O2 delivery during and after resuscitation. As a rapidly deployable, noninvasive
monitor of peripheral tissue oxygenation and O2 delivery, skeletal muscle StO2
obtained using NIR spectrometry would be useful to guide resuscitation in the
intensive care unit, to monitor resuscitation status in the operating room, and,
potentially, in combination with indicators such as base deficit and lactate, to
detect shock during initial assessment of the severe trauma patient in the
emergency department.
PMID- 10780597
TI - Effects of trauma cases on the care of patients who have chest pain in an
emergency department.
AB - BACKGROUND: Trauma victims sometimes take priority over other patients because
their injuries require immediate treatment. We examined whether such demands
might compromise the care of patients with acute chest pain in an emergency
department. METHODS: Case patients were patients with chest pain who arrived
immediately after a major trauma victim. Control patients were patients with
chest pain who arrived on a preceding day when no trauma patient was in the
emergency department. RESULTS: Case and control patients were similar in mean age
(60 vs. 60 years, p = not significant), percentage male (47 vs. 53%, p = not
significant) and percentage ultimately diagnosed as cardiac (29 vs. 33%, p = not
significant). Case patients spent an average of 81 minutes longer in the
emergency department (297 vs. 216 minutes, p = 0.009). Similar delays were
observed in the subgroup of patients ultimately diagnosed as cardiac (309 vs. 217
minutes, p = 0.029). Case patients had generally worse scores on the American
College of Emergency Physicians Quality Assurance Index (75.6 vs. 84.4, p =
0.027), particularly those ultimately diagnosed as cardiac (60.3 vs. 85.1, p =
0.002). The common failures were failure to administer aspirin, undertreatment of
ongoing pain, and failure to provide instructions regarding treatment and need to
return. CONCLUSION: Trauma victims can decrease the timeliness and quality of
care for other patients who have potentially life-threatening conditions in an
emergency department.
PMID- 10780596
TI - Effect of prehospital advanced life support on outcomes of major trauma patients.
AB - OBJECTIVE: Determine whether prehospital advanced life support (ALS) improves the
survival of major trauma patients and whether it is associated with longer on
scene times. METHODS: A 36-month retrospective study of all major trauma patients
who received either prehospital bag-valve-mask (BVM) or endotracheal intubation
(ETI) and were transported by paramedics to our Level I trauma center. Logistic
regression analysis determined the association of prehospital ALS with patient
survival. RESULTS: Of 9,451 major trauma patients, 496 (5.3%) had either BVM or
ETI. Eighty-one percent received BVM, with a mean Injury Severity Score of 29 and
a mortality rate of 67%; 93 patients (19%) underwent successful ETI, with a mean
Injury Severity Score of 35 and a mortality rate of 93%. Adjusted survival for
patients who had BVM was 5.3 times more likely than for patients who had ETI (95%
confidence interval, 2.3-14.2, p = 0.00). Survival among patients who received
intravenous fluids was 3.9 times more likely than those who did not (p = not
significant). Average on-scene times for patients who had ETI or intravenous
fluids were not significantly longer than those who had BVM or no intravenous
fluids. CONCLUSION: ALS procedures can be performed by paramedics on major trauma
patients without prolonging on-scene time, but they do not seem to improve
survival.
PMID- 10780598
TI - Alterations of preliminary readings on radiographic examinations minimally affect
outcomes of trauma patients discharged from the emergency department.
AB - BACKGROUND: We hypothesized that trauma patients could be discharged safely from
the emergency department (ED) before the availability of official readings for
their radiologic examinations. We also sought to determine whether trauma
patients were more prone to alterations of preliminary interpretations than other
ED patients. METHODS: Alterations of preliminary readings (PR) for patients
discharged from the ED were reviewed. If the official readings conflicted with
the PR used for the patient's disposition, attempts were made to contact the
patient and provide the appropriate follow-up. Data recorded included the type of
radiographic examination, the presence of a missed injury, and the follow-up. By
using institutional data, the incidence of inaccurate PR were compared for trauma
patients and other ED patients (chi2 test, Fisher exact test, p < 0.05). RESULTS:
Between January of 1998 and December of 1998, 102 of 38,260 discharged ED
patients had official readings differing from PR. Forty-three of the changed
readings involved 42 of the 1,073 discharged trauma patients, who were more
likely to harbor inaccurate PR (<0.0001) than other discharged ED patients.
Twenty-eight altered readings involved plain films and 15 involved computed
tomographic scans. The most common altered readings involved computed tomographic
scans of the head and face (n = 13). Twelve missed injuries were detected, most
commonly related to a missed injury of the extremity (7 cases). Nine other cases
involved the detection of incidental pathologic conditions. Eight patients
required repeat ED visits for clinical and radiographic evaluation, and one
patient required subsequent hospital admission. CONCLUSION: Discharged trauma
patients are more likely to harbor alterations of preliminary interpretations
than other ED patients. Although the official readings for these trauma patients
will occasionally reveal previously undetected pathologic conditions, the
majority of such cases can be managed with outpatient follow-up.
PMID- 10780599
TI - Training residents using simulation technology: experience with ultrasound for
trauma.
AB - BACKGROUND: The need for surgeons to become proficient in performing and
interpreting ultrasound examinations has been well recognized in recent years,
but providing standardized training remains a significant challenge. The UltraSim
(MedSim, Ft. Lauderdale, Fla) ultrasound simulator is a modified ultrasound
machine that stores patient data in three-dimensional images. By scanning on the
UltraSim mannequin, the student can reconstruct these images in real-time,
eliminating the need for finding normal and abnormal models, while providing an
objective method of both teaching and testing. The objective of this study was to
compare the posttest results between residents trained on a real-time ultrasound
simulator versus those trained in a traditional hands-on patient format. We
hypothesized that both methods of teaching would yield similar results as judged
by performance on the interpretive portion of a standardized posttest. It is
designed as a prospective, cohort study from two university trauma centers
involving residents at the beginning of their first or second postgraduate year
of training. The main outcome measure was performance on a standardized posttest,
which included interpretation of ultrasound cases recorded on videotape. METHODS:
Students first took a written pretest to evaluate their baseline knowledge of
ultrasound physics as well as their ability to interpret basic ultrasound images.
The didactic portion of the course used the same teaching materials for all
residents and included lectures on ultrasound physics, ultrasound use in
trauma/critical care, and a series of instructional videos. This didactic session
was followed by 1 hour for each student of hands-on training on medical
models/medical patients (group I) or by training on the ultrasound simulator
(group II). The pretest was repeated at the completion of the course (posttest).
Data were stratified by postgraduate year, i.e., PG1 or PG2. RESULTS: A total of
74 residents were trained and tested in this study (PG1 = 48, PG2 = 26). All
residents showed significant improvement in their pretest and posttest scores (p
= 0.00) in both their knowledge of ultrasound physics and in their interpretation
of ultrasound images. Importantly, we could not demonstrate any significant
difference between groups trained on models/patients (group I) versus those
trained on the simulator (group II) when comparing their posttest interpretation
of ultrasound images presented on videotapes (PG1, group I mean score 6.9 +/- 1.4
vs. PG1, group II mean score 6.5 +/- 1.6, p = 0.32; PG2, group I mean score 7.7
+/- 1.4 vs. PG2, group II mean score 7.9 +/- 1.2, p = 0.70). CONCLUSION: The use
of a simulator is a convenient and objective method of introducing ultrasound to
surgery residents and compares favorably with the experience gained with
traditional hands-on patient models.
PMID- 10780600
TI - The April 8, 1998 tornado: assessment of the trauma system response and the
resulting injuries.
AB - BACKGROUND: On April 8, 1998, an F5 tornado touched down in two counties of
Alabama producing a wide path of destruction. The presence of a regional trauma
system in this area presents an opportunity to evaluate the effectiveness of the
system in responding to the victims of this natural disaster. METHODS: Emergency
room logs and the regional trauma system database were searched for all patients
treated for injuries sustained from the tornado, and medical records were
reviewed for demographic information, mode of transportation to hospital,
injuries, treatment, and outcome. Fatalities were identified by means of the
coroner's office. RESULTS: A total of 224 patients were evaluated at nine area
hospitals, of whom 63 (28%) required admission. There were 32 deaths: 30 persons
were dead at the scene, and 2 patients subsequently died at Level I trauma
centers. Among patients with nonfatal injuries, 39% were managed at Level I
facilities, 46% at Level III facilities, and 15% at nontrauma facilities. Forty
patients (55%) seen at Level I facilities required admission compared with 15
patients (17%) at Level III facilities and 8 patients (29%) at nontrauma
facilities; Level I facilities also had the highest Injury Severity Score. Of
patients requiring admission, 83% were transported by emergency medical services;
these patients also had the highest Injury Severity Score. CONCLUSION: The
regional trauma system facilitated appropriate and efficient triage to system
hospitals, routing the most severely injured patients to the Level I centers
without overwhelming them with the more numerous, less severely injured patients.
PMID- 10780601
TI - Thoracic aortic injury: how predictive is mechanism and is chest computed
tomography a reliable screening tool? A prospective study of 1,561 patients.
AB - BACKGROUND: Thoracic aortic injury (TAI) is a devastating condition in which
prompt recognition can obviate morbidity and mortality. It is a long-held belief
that TAI is more likely when there is a "major mechanism of injury." The purposes
of this prospective study were to determine mechanism characteristics that are
predictive of TAI and to evaluate chest computed tomography (CT) as a screening
tool for TAI. METHODS: Over a 5 1/2 year period, blunt chest trauma patients at
two Level I trauma centers were evaluated for potential TAI. Patients were
assigned mechanism and radiograph scores from 1 (low suspicion for TAI) to 5
(very high suspicion for TAI). Immediate aortography was obtained when suspicion
for TAI was very high. The remaining patients were evaluated with contrast
enhanced chest CT. Confirmatory aortography was obtained on all positive chest CT
scans and on all patients with mechanism scores of 4 or 5 even if the CT was
negative. Mechanism and radiographic data were correlated with the results of
aortic imaging. RESULTS: Of the 1,561 patients evaluated for TAI, 30 aortic
injuries were found. The assessment of mechanism was imperfect with a reliance on
often incomplete and subjective data. The subjective mechanism score proved to be
the most useful predictor of TAI. Radiographic scores were useful but insensitive
for intimal injuries. Computed tomography was found to have 100% and 100% NPV for
TAI. CONCLUSION: Considering the inherent difficulties in identifying patients at
risk for TAI and the effectiveness of chest CT as a screening tool for aortic
injury, we recommend liberal use of chest CT in blunt chest trauma. Guidelines
for determining the need for aortic imaging are outlined.
PMID- 10780602
TI - Is routine roentgenography needed after closed tube thoracostomy removal?
AB - BACKGROUND: Efficacy of chest radiograph protocol after tube thoracostomy tube
(CT) removal. METHODS: Retrospective review (July of 1995 to July of 1996) of 141
patients with CT followed throughout their hospitalization. Excluded patients
died (23 patients) or had thoracotomy (13 patients) before CT removal. RESULTS: A
total of 105 patients had 113 CT removed (mean age, 36.9 years; Injury Severity
Score = 23.4; CT duration, 5.0 days). Protocol chest radiographs were performed
on average at 7.9 and 22.1 hours. Recurrent pneumothorax (RHPTX = new
interpleural air) occurring in 12 patients (11%) and persistent pneumothorax
(PHPTX = same volume of interpleural air) occurring in 13 patients (12%) caused
no clinical problems and were treated without tube replacement. Three patients
had symptoms after removal; none had RHPTX. Two patients had clinical signs; one
reaccumulated a hemothorax requiring CT replacement, the other improved without
replacement. CONCLUSIONS: Clinically significant RHPTX/PHPTX after CT removal is
infrequent. Signs not symptoms detect CT removal complications. At our
institution, chest radiographs are obtained in a delayed manner from protocol and
offer no benefit over clinical assessment.
PMID- 10780604
TI - Treatment of humeral shaft delayed unions and nonunions with humeral locked
nails.
AB - OBJECTIVE: To report experience with use of humeral locked nails in treating
humeral delayed unions and nonunions. The following techniques yielded
encouragingly good results: static locking, short-to-long segment nailing, bone
grafting, fracture compression, and minimal surgical trauma. DESIGN AND METHODS:
A total of 41 consecutive patients with 13 delayed unions and 28 nonunions were
treated with humeral locked nails. Delay from trauma to surgery averaged 4.2
months for delayed union and 15.5 months for nonunion. The average age of
patients was 50.2 years; average follow-up time was 23.2 months. There were 7
proximal-third fractures, 21 middle-third fractures, and 13 distal-third
fractures. The antegrade approach was used for 13 fractures and retrograde for
28. Open nailing was performed in 39 fractures and closed nailing in 2. If the
fracture motion was still present after nail insertion, axial compression of the
fracture site was specially applied. Bone grafting was performed in the fractures
with open nailing. Thirty-four fractures were nailed with 8-mm nails, and 7
fractures were nailed with 7-mm nails. RESULTS: With a single operation, all but
two patients achieved osseous union in, on average, 5.6 months. One of these two
patients eventually gained union after another surgery with fracture compression
along the original nail and concurrent bone grafting. The second patient,
undergoing hemodialysis for chronic renal failure, had persistent nonunion. At
follow-up, for patients with antegrade nailing, all but four patients had less
than 20 degrees limitation of shoulder abduction. For patients with retrograde
nailing, all but two had less than 10 degrees limitation of elbow motion. Only
the patient with persistent nonunion had continual pain and significant
impairment of arm function. CONCLUSIONS: Humeral locked nailing seems to be
effective for humeral delayed unions or nonunions. It may be an acceptable
alternative for fractures unsuited for plate fixation, such as those with
comminution, osteoporosis, or a severely adhered radial nerve.
PMID- 10780603
TI - Effects of timing of diatrizoate (water-soluble contrast medium) administration
on pancreatic microcirculatory derangement in cerulein pancreatitis in rats.
AB - OBJECTIVE: We investigated whether the timing of administration of contrast
medium after onset of acute pancreatitis is critical in determining the magnitude
of microcirculatory derangement. METHODS: An acute pancreatitis model in male
Sprague-Dawley rats (225-275 g) was established by continuous infusion of
cerulein (15 mg/kg per hour). The mean arterial pressure was monitored
continuously by means of a femoral artery catheter. Diatrizoate (Hypaque-76), a
water-soluble contrast medium, was delivered through a femoral vein catheter at
doses corresponding to those given to humans, either 1, 2, or 3 hours after
pancreatitis induction. In vivo microscopy and laser-Doppler flowmetry were used
to investigate microcirculatory derangement. The water contents of the pancreas
and lung, the malondialdehyde levels of the pancreas, and the trypsinogen
activation peptide levels in the serum were measured at the end of the experiment
(8 hours after infusion of cerulein). RESULTS: Early administration of contrast
medium (1 hour after pancreatitis induction) resulted in significantly greater
changes in microcirculation and mean arterial pressure than did late
administration (2 or 3 hours after pancreatitis induction). Rats given contrast
medium 1 hour after induction also had highest pancreas and lung water contents,
the highest pancreas malondialdehyde levels, and the highest serum trypsinogen
activation peptide levels. CONCLUSION: These results show that a water soluble
contrast medium that is often used for computed tomographic imaging of the
pancreas can adversely affect the pancreatic microcirculatory parameters, such as
tissue perfusion and leukocyte sticking, and hemodynamics in a cerulein-induced
model of acute pancreatitis. Early administration seems to cause more severe
derangement of the pancreatic microcirculation.
PMID- 10780605
TI - Central hemodynamics during reamed intramedullary nailing of unilateral tibial
fractures.
AB - BACKGROUND: Intramedullary nailing of a long-bone fracture results in
intravasation of bone marrow contents into the right atrium and pulmonary
vascular bed and, therefore, may alter cardiac and pulmonary hemodynamics.
METHODS: Central hemodynamic changes were recorded in 12 healthy adults with a
unilateral simple tibial fracture undergoing intramedullary nailing. The patients
were cannulated with a pulmonary artery catheter. Reamed intramedullary nailing
was performed during general anesthesia. Preoperative and immediate postoperative
hemodynamic variables were compared and intraoperative changes studied. RESULTS:
During the operation, the right ventricular preload as represented by central
venous pressure and the right ventricular afterload as presented by mean
pulmonary arterial pressure increased significantly. Preoperative and
postoperative arterial oxygen tension values demonstrated hypoxia. Abnormal
pulmonary shunting and increased oxygen consumption were observed as well.
CONCLUSION: Changes in cardiac and pulmonary hemodynamics are already present
after the trauma and before the reamed intramedullary nailing procedure.
PMID- 10780606
TI - Analysis of pulmonary fat embolism in blunt force fatalities.
AB - OBJECTIVE: To investigate the incidence, severity, and origin of pulmonary fat
embolism (PFE) in persons dying from blunt force trauma within 24 hours of
injury. METHODS: The study population consisted of blunt force fatalities.
Controls were subjects dying from natural causes or nonblunt force injury. Tissue
was removed from lung lobes and prepared for histologic examination using osmium
tetroxide to stain for fat. Lung sections were graded for PFE on a scale of 0 (no
emboli) to 4 (five or more emboli in a majority of fields). RESULTS: The blunt
force group consisted of 56 decedents. Mortality was 93% within 4 hours.
Fractures were present in 54 (96%) of decedents, and soft tissue injury was
universal. Thirty eight (68%) of decedents were positive for PFE vs. 3 of 20
(15%) in controls. Mean score for PFE was 2.94 +/- 1.15 and 1.01 +/- 0.94,
respectively (p < 0.005). Bone marrow emboli were not observed in any of the
sections. Severity of PFE was positively associated with survival time. Analysis
of PFE against sex, age, height, weight, number of injuries, and number of
fractures showed no significant correlations. CONCLUSIONS: A significant degree
of PFE develops rapidly in a majority of persons dying of blunt force trauma.
Although the source of fat for embolization has been suggested to be bone marrow,
no evidence of myeloid tissue was found in any of the lung sections. Nor was
there a correlation of PFE and number of fractures. Soft tissue injury is
considered the primary cause of PFE.
PMID- 10780607
TI - Isolated acute knee injuries in the general population.
AB - OBJECTIVE: Knee injuries are common in the general population, yet most studies
have concentrated on special populations. The purpose of this study was to
describe the types of injuries, injury events, age, and sex distributions in a
community population. METHODS: The medical records of all residents of Olmsted
County, Minnesota, 17 years of age or older who had a first visit for an isolated
acute knee (acute was defined as occurring within 60 days of the physician visit)
injury between January 1, 1993, and January 1, 1996, were abstracted. RESULTS: A
total of 664 patients (4/1,000 community adults, 46% women and 54% men) presented
to a physician for evaluation and treatment of an isolated acute knee injury.
Injured men were on average younger than women and more likely to have an injury
during a sports activity, whereas women's injuries were more likely to be the
result of non-sports-related falls. Knee sprain or strain was the most common
final diagnosis (36%). Approximately half (49%) of the patients had a single
visit. The likelihood of orthopedic surgeon's care (37% overall) increased with
injury severity and age of the patient. Overall, 12% of subjects had surgical
treatment recommended. CONCLUSION: Knee injuries are common, often result in a
single visit, seldom receive surgical intervention, and the majority are cared
for entirely by generalist physicians.
PMID- 10780608
TI - Nonskeletal cervical spine injuries: epidemiology and diagnostic pitfalls.
AB - BACKGROUND: Cervical spine injuries are the most commonly missed severe injuries
with serious implications for the patient and physician. The diagnosis of
subluxations or spinal cord injuries in the absence of vertebral fractures,
especially in unevaluable patients, poses a major challenge. The objective of
this study was to study the incidence and type of cervical spine trauma according
to mechanism of injury; identify problems and pitfalls in the diagnosis of
nonskeletal cervical spine injuries. METHODS: Retrospective study of all C-spine
injuries caused by traffic accidents or falls admitted over a 5-year period at a
large Level I trauma center. Data were obtained from the trauma registry, review
of patient charts, and radiology reports. RESULTS: During the study period, there
were 14,755 admissions due to traffic injuries or falls who met trauma center
criteria. There were 292 patients with C-spine injuries, for an overall incidence
of 2.0% (3.4% in car occupants, 2.8% for pedestrians, 1.9% for motorcycle riders,
and 0.9% for falls). The incidence of C-spine injuries in patients with a Glasgow
Coma Scale score of 13 to 15 was 1.4%, 9 to 12 was 6.8%, and in < or =8 was 10.2%
(p < 0.05). Of C-spine injuries, 85.6% (250 patients) were a vertebral fracture,
10.6% of the injuries (31 patients) were subluxation without fractures, and 3.8%
(11 patients) were an isolated spinal cord injury without fracture or
subluxation. Of the 31 patients with isolated subluxations, one-third required an
early endotracheal intubation before clinical evaluation of the spine, because of
associated severe head injury or hypotension. Adequate lateral C-spine films
diagnosed or suspected 30 of the 31 subluxations (96.8%). The combination of
plain films and computed tomographic (CT) scan diagnosed or suspected all
injuries. Of the 11 patients with isolated cord injury, 27.3% required early
intubation before clinical evaluation of the spine. The diagnosis of cord injury
was made on admission in only five patients (45.5%). In three patients, the
neurologic examination on admission was normal and neurologic deficits appeared a
few hours later. In the remaining three patients (two intubated, one
intoxicated), the diagnosis was missed clinically and radiologically.
CONCLUSIONS: Isolated nonskeletal C-spine injuries are rare but potentially
catastrophic because of the high incidence of neurologic deficits and missed
diagnosis. In subluxations, the combination of an adequate lateral film and CT
scan was reliable in diagnosing or highly suspecting the injury. A large
prospective study is needed to confirm these findings, before a recommendation is
made to remove the cervical collar if the findings of these investigations are
normal. However, in isolated cord injuries, the diagnosis was often missed
because of associated severe head trauma and the low sensitivity of the plain
films and CT scans.
PMID- 10780609
TI - Intrathoracic blood volume as an end point in resuscitation of the severely
burned: an observational study of 24 patients.
AB - BACKGROUND: Treatment of burn shock according to empirical resuscitation formulas
is still considered the gold standard, and the burn community does not advocate
the use of invasive cardiorespiratory monitoring in general. As a consequence,
data dealing with early postburn hemodynamics are sparse, and only few studies
have paid attention to the topic of end-point burn shock resuscitation. However,
recent studies have suggested that burn survival may be improved when invasive
monitoring is used to guide fluid therapy during the shock phase. MATERIALS AND
METHODS: In an observational study of 24 patients with severe burns, the
transpulmonary double indicator dilution technique was used for semi-invasive
hemodynamic monitoring. The clinical utility of the intrathoracic blood volume
(ITBV) as an end-point variable for fluid resuscitation was evaluated, comparing
correlation of filling pressure obtained by a pulmonary artery catheter and
intrathoracic blood volume to cardiac index and oxygen delivery. In addition
fluid volume predicted by the Parkland burn formula was compared with the actual
fluid volume given when ITBV was used as end point for resuscitation. RESULTS:
ITBV-guided resuscitation was associated with restoration of preload and
peripheral delivery of oxygen within 24 hours in the majority of patients.
Augmentation of ITBV was significantly correlated with changes in cardiac index
and oxygen transport rate. No such correlation could be demonstrated for the
conventional preload parameters such as central venous pressure and pulmonary
capillary wedge pressure. Thus, ITBV seemed in burned, hypovolemic patients a
better indicator of the preload component of the cardiac output than the
conventional preload parameters obtained with the pulmonary artery catheter.
Significantly larger volumes of crystalloids than predicted by the Parkland
formula were administered when ITBV was used as end point for resuscitation. The
extravascular lung water remained normal during this extraordinary high volume
load. CONCLUSION: ITBV may be a reliable preload indicator to guide volume
therapy in life-threatening burns, and end-point-fixed resuscitation to this
parameter seems to be associated with significantly higher fluid administration
than calculated compared with traditional burn formulas. The effects of burn
resuscitation to fixed end points on survival and multiple organ failure should
be evaluated in future randomly assigned trials.
PMID- 10780610
TI - Civilian landmine injuries in Sri Lanka.
AB - OBJECTIVES: The purpose of this study was to describe the injuries sustained by
displaced people returning home after a military conflict when landmines were not
removed. METHOD: This study describes the landmine injuries to patients at the
Jaffna Teaching Hospital in northern Sri Lanka over a 20-month period, from May
1, 1996, to December 31, 1997. RESULTS: There were definite and identifiable
landmine injury patterns. Patients were most often wounded in the lower
extremities, had multiple wounds, and were injured together in groups. Victims
were most often male, but there were unusually high numbers of women, children,
and elderly injured. Mortality rates and amputation rates were high. Deaths
occurred early after injury. Higher incidences of mine injuries could be
associated with two important activities: returning home and agriculture.
CONCLUSIONS: Civilians returning home after armed conflicts are at risk of injury
when landmines are not removed. No one is spared. This problem is preventable.
PMID- 10780611
TI - Mechanisms and patterns of injuries related to large animals.
AB - BACKGROUND: Injuries from encounters with large animals represent a significant
health risk for rural communities. We evaluated our regional trauma centers'
experience with large-animal injuries to determine whether certain mechanisms and
patterns of injury predicted either major head/craniofacial or torso
(chest/abdomen/pelvis) trauma. METHODS: The hospital courses of 145 patients with
injuries related to large animals were reviewed retrospectively to determine
patterns of injury, specific injury mechanisms, species-specific injuries, and
predictors of multiple body region trauma. RESULTS: Seventy-nine patients (55%)
were injured by horses, 47 patients (32%) by bulls, 16 patients (11%) by cows,
and 3 patients (2%) by wild animal attacks. The predominant species-specific
mechanisms of injury were falls (horses), tramplings (bulls), and kicks (cows).
Brain/craniofacial injuries were most common from horse-related encounters (32%),
whereas bull and cow encounters usually resulted in torso injuries (45% and 56%,
respectively). Multiple body region injuries occurred in 32% of patients.
Fractures of the upper extremities were more often associated with torso and
head/craniofacial injuries (48%) than lower extremity injuries (17%) (p = 0.02).
CONCLUSION: Large animal injuries frequently involve multiple body regions with
species-specific mechanisms. Upper extremity injuries are associated with a
significantly higher percentage of torso and head/craniofacial injuries, which
may have implications for field triage.
PMID- 10780612
TI - Pancreatographic classification of pancreatic ductal injuries caused by blunt
injury to the pancreas.
AB - BACKGROUND: In the treatment of patients with pancreatic injury, the focus of
attention is usually on main ductal injuries. METHODS: To develop a
classification system for pancreatic ductal injuries, we retrospectively analyzed
blunt pancreatic injuries in 40 patients. We assessed the relationships between
findings on pancreatography (36 endoscopic retrograde procedures and 4
transduodenal procedures), the treatment modality, and the clinical course.
RESULTS: Patients with class 1 injuries (radiographically normal ducts, n = 13)
could be treated nonsurgically without major complications. Patients with class 2
injuries (branch injuries, n = 7), in whom contrast medium from ductal branches
did not leak from the pancreatic parenchyma (class 2a, n = 3), could be treated
nonsurgically. Patients with leaks into the retroperitoneal space (class 2b, n =
4) required at least a drainage laparotomy. Patients with class 3 injuries (main
duct injuries, n = 20), including two patients in whom conservative treatment
resulted in severe complications, required laparotomy. CONCLUSION: This
classification system for pancreatic ductal injuries may facilitate the selection
of appropriate therapeutic modalities for patients with blunt pancreatic injury.
PMID- 10780613
TI - Practice Management Guidelines for Prophylactic Antibiotic Use in Tube
Thoracostomy for Traumatic Hemopneumothorax: the EAST Practice Management
Guidelines Work Group. Eastern Association for Trauma.
AB - Multiple factors contribute to the development of posttraumatic empyema. These
factors include the conditions under which the tube is inserted (emergent or
urgent), the mechanism of injury, retained hemothorax, and ventilator care. The
incidence of empyema in placebo groups ranges between 0 and 18%. The
administration of antibiotics for longer than 24 hours did not seem to
significantly reduce this risk compared with a shorter duration, although the
numbers in each series were small. Most reports found a significant reduction in
pneumonitis when patients received prolonged prophylactic antibiotics. This use
of antibiotics might possibly be better described as presumptive therapy rather
than prophylactic.
PMID- 10780614
TI - The EAST Practice Management Guidelines for Prophylactic Antibiotic Use in Tube
Thoracostomy for Traumatic Hemopneumothorax: a commentary. Eastern Association
for Trauma.
PMID- 10780615
TI - Scandinavian guidelines for initial management of minimal, mild, and moderate
head injuries. The Scandinavian Neurotrauma Committee.
AB - BACKGROUND: The Scandinavian Neurotrauma Committee was initiated by the
Scandinavian Neurosurgical Society to develop evidence-based guidelines for
improved care of neurotrauma patients. METHODS: A MEDLINE search identified 475
papers dealing with the management of minimal, mild, and moderate head injuries.
Forty-two studies presenting class II evidence on the initial management of such
injuries were reviewed and management guidelines were developed. RESULTS:
Implementation of the Head Injury Severity Scale is advocated. Patients with
minimal injuries (no loss of consciousness, Glasgow Coma Scale score of 15) can
be safely discharged. Routine early computed tomographic scan is recommended in
cases with mild injuries (history of loss of consciousness, Glasgow Coma Scale
score = 14-15) and patients with normal scans may be discharged. Computed
tomographic scan and admission is mandatory in moderate injuries (Glasgow Coma
Scale score = 13). All patients harboring additional risk factors should be
scanned and admitted. A flow-chart for clinical decision making and a Head Injury
Instruction card is introduced. CONCLUSIONS: The Scandinavian Neurotrauma
Committee suggests guidelines that should be safe and cost-effective for the
initial management of minimal, mild, and moderate head injuries.
PMID- 10780616
TI - Osteocutaneous pedicle flap of the foot for salvage of below-knee amputation
level after lower extremity injury.
PMID- 10780617
TI - "Flow-through" type free flap for revascularization and simultaneous coverage of
a nearly complete amputation of the foot: case report and literature review.
PMID- 10780618
TI - Unilateral transverse acetabular fracture with medial displacement of the femoral
head after an epileptic seizure.
PMID- 10780619
TI - Massive extraperitoneal hemorrhage after soft tissue trauma to the pubic branch
of the inferior epigastric artery.
PMID- 10780620
TI - Postinjury torso ultrasound: FAST should be SLOH.
PMID- 10780621
TI - Vancomycin-dependent enterococcal strains: case report and review.
AB - We report, to our knowledge, the first isolation of VDE from a burn unit. Our
experience was similar to earlier reports, in that continuous administration of
vancomycin and previous VRE isolation preceded the recovery of VDE. Given the
increasing prevalence of VRE as a nosocomial pathogen, intensive care units must
now be attuned to the emergence of VDE as serious pathogen.
PMID- 10780622
TI - Eye injuries from airbags with seamless module covers.
AB - BACKGROUND: A recent trend in automotive interior design has the airbag placed
behind a seamless module cover. Airbag deployment through these seamless module
covers may release foam particles at high velocities that could result in eye
injuries. METHODS: Twenty-one tests (n = 21) were performed in which foam
particles, similar to those observed from airbag deployments, were impacted onto
porcine eyes. Injury analysis was performed by using fluorescein dye, ophthalmic
ultrasound, and necropsy. RESULTS: As seen in case reports of airbag-induced eye
injuries, corneal abrasions were the most recorded injuries in the porcine eye
impact tests. A logistic regression analysis demonstrated that kinetic energy was
the most significant contributor to injury (p = 0.0023), whereas foam type was a
poor contributor to the model (p = 0.45). An injury risk curve was generated
based on kinetic energy that gave a 50% risk of corneal abrasion at 0.183 J.
CONCLUSION: If the production of foam particles during airbag deployment is
unavoidable, the injury risk function presented for the kinetic energy of the
particles offers a design guide to minimize corneal abrasions.
PMID- 10780623
TI - Pediatric aortic pseudoaneurysm associated with a gunshot wound to the chest.
PMID- 10780624
TI - Descending aortic cannulation during emergent thoracotomy for a trauma victim.
PMID- 10780625
TI - Eye movement abnormalities during reading in patients with Alzheimer disease.
AB - OBJECTIVE: This goal of this study was to evaluate reading ability by assessing
eye movements during reading among patients with Alzheimer disease (AD) compared
with normal elderly controls. BACKGROUND: Reading is disturbed in patients with
AD. These patients may have changes in reading ability early in the course of
their disease before clinical alexia or abnormalities are apparent on standard
reading tasks. METHOD: Reading competence was evaluated by recording eye
movements during reading in 14 patients with mild to moderate clinically probable
AD and 14 age- and education-matched controls. RESULTS: All patients with AD
could recognize letters and words and could understand written material of
similar difficulty. Despite successful reading comprehension among the patients
with AD, their oculographs showed slowed reading and irregular eye movements.
Compared with controls, the patients with AD did not differ in saccadic duration;
however, they had significantly longer fixation times, more forward saccades per
line of text, and more saccadic regressions. In addition, increased reading
difficulty significantly correlated with a scale of dementia severity in the
patients with AD. CONCLUSIONS: This pattern of eye movements corresponds to
increased text difficulty and probably represents difficulty with lexical
semantic access in AD. These results suggest that disordered eye movements can
signal difficulties in reading ability in AD even before complaints of reading
difficulty or abnormalities on reading tests and may be a means of identifying
linguistic impairment early in this disorder.
PMID- 10780626
TI - Impaired insight in Alzheimer disease: association with cognitive deficits,
psychiatric symptoms, and behavioral disturbances.
AB - OBJECTIVE: The purpose of this study was to evaluate symptoms associated with
impaired insight in patients with Alzheimer disease (AD). BACKGROUND: Although
unawareness of deficits is common in AD, the relation of awareness to psychiatric
and behavioral disturbances has not been extensively studied. METHOD: We
conducted a cross-sectional investigation of 91 patients with probable AD
according to the criteria of the National Institute of Neurological and
Communicative Disorders and Stroke and the Alzheimer's Disease and Related
Disorders Association. Awareness of cognitive and functional deficits was
measured with the Inaccurate Insight item from the Neurobehavioral Rating Scale.
Psychiatric and behavioral symptoms were measured using factor scores and
individual items from the Neurobehavioral Rating Scale. Global cognitive deficits
were measured using the Mini-Mental State Examination (MMSE). RESULTS: Stepwise
regression analysis showed that insight was associated with MMSE score,
depression/anxiety factor score, and agitation/disinhibition factor score.
Variables not associated with awareness of deficits included patient age,
behavioral retardation factor score, verbal output disturbance factor score, and
psychosis factor score. Post hoc analyses showed a positive relation (i.e.,
greater insight, more symptomatology) between deficit awareness and symptoms of
depressed mood and anxiety. There was a negative relation (i.e., greater insight,
less symptomatology) between insight and symptoms of hostility, agitation,
inattention, and tension. In a follow-up stepwise regression analysis, increased
deficit awareness was associated with a higher MMSE score, greater depressed
mood, and decreased agitation. CONCLUSIONS: These findings suggest that patients
with AD may experience symptoms of depressed mood in relation to increased
awareness of decrements in functioning. The data also indicate that patients with
poor insight demonstrate greater agitated behavior. Consistent with previous
research, impaired insight was higher in the later stages of the illness.
PMID- 10780627
TI - Right body side performance decrement in congenitally dyslexic children and left
body side performance decrement in congenitally hyperactive children.
AB - OBJECTIVE: Simple and complex visuomotor performance of the right and left sides
of the body was investigated in 37 children with left hemisphere lesions, 35
children with right hemisphere lesions, 53 developmentally dyslexic children, 29
developmentally hyperactive children, and 35 "normal" children who had endured a
very mild head injury with no sequelae. BACKGROUND: Lateralized soft signs, EEG
topography, metabolic brain imaging, and neuropsychological test profiles suggest
a predominance of left hemisphere dysfunction in dyslexia and right hemisphere
dysfunction in hyperactivity. METHOD: Nine measures of lateralized performance
were drawn from the Purdue pegboard, Letter cancellation, Rey complex figure,
Wechsler Intelligence Scale for Children (WISC) Mazes, and WISC Picture
completion tests. RESULTS: The children with left hemisphere lesions manifested
significantly weaker performance on test components involving the right body
side, relative to the normal controls, on the Purdue pegboard, Rey complex figure
(delayed recall condition), and WISC Picture completion tests, and the dyslexic
children on the former two. The children with right hemisphere lesions manifested
significantly weaker performance on test components involving the left body side,
relative to the normal controls, on the WISC Mazes test, as did the hyperactive
children. CONCLUSIONS: We propose that (1) contralateral performance decrement
results from a unilateral cortical lesion in children, and (2) developmental
dyslexia may comprise a slight predominance of left hemisphere dysfunction and
developmental hyperactivity of right hemisphere dysfunction.
PMID- 10780628
TI - Radiotherapeutic effects on brain function: double dissociation of memory
systems.
AB - OBJECTIVE: The neurocognitive sequelae of therapeutic cranial irradiation are not
well characterized in adults with primary brain tumors. To address this problem,
we prospectively examined neuropsychological findings during two phases of
radiation effects. BACKGROUND: Investigations of radiation effects have revealed
variable outcomes that range from no radiation-associated morbidity to severe
cognitive impairment, but have relied on case reports or retrospective studies of
late-delayed changes in white matter or in cognition. No reliable radiographic or
neurocognitive tools exist to describe the multiple phases of radiation effects.
METHOD: Twenty adult patients (median age, 39 years) from a university hospital
were treated with radiotherapy (RT) for low-grade primary brain tumors.
Prospective longitudinal neuropsychological studies were compared at baseline
(after surgery and before irradiation) and at 3, 6, and 12 months after RT to
examine early-delayed effects, including verbal memory changes in 20 patients and
visual memory changes in 11 patients. We also examined cognitive changes during
the late-delayed phase for up to 3 years after RT and determined whether early
delayed memory deficit predicted late-delayed memory deficit in a small subset of
patients. A comprehensive neuropsychological battery was used, including verbal
and visual memory tests designed to compare learning, storage, and retrieval.
RESULTS: Patients demonstrated normal verbal memory at baseline, decrement, and
then rebound in verbal retrieval. Deficit at baseline and recovery up to 1 year
after RT defined visual memory. Together, these observations constitute a double
dissociation of memory functions. No changes over time were observed in other
neurocognitive tests or in fatigue or mood measures. Time-dependent patterns of
each long-term memory test were examined in relation to lesion site in individual
patients. CONCLUSIONS: The double dissociation of memory functions after RT may
provide markers for the damaging and facilitative early-delayed effects of RT.
Late-delayed effects were not predicted based on early-delayed changes in a small
sample.
PMID- 10780629
TI - A neuropsychological study of the postpolio syndrome: support for depression
without neuropsychological impairment.
AB - OBJECTIVE: This study aimed to examine cognitive functioning in postpolio
syndrome (PPS) after controlling for the effects of depression and illness
behavior. BACKGROUND: Few studies have investigated the possible cognitive
sequelae of PPS, despite widespread documented subjective complaints of "mental
fatigue." METHOD: A total of 23 PPS sufferers, 20 polio survivors without PPS,
and 22 matched controls were compared using the Beck Depression Inventory-II; the
Illness Behaviour Questionnaire; a chronic fatigue syndrome symptom checklist;
and several measures of memory, attention, and concentration, including the Brown
Petersen Task, Stroop Test, Austin Maze, California Verbal Learning Test, Trail
Making Test, Controlled Oral Word Association Test, and Symbol-Digit Modalities
Test. RESULTS: In those participants with a medically confirmed diagnosis of PPS,
there was a significantly higher level of depressive and hypochondriacal
symptomatology as compared with the other two groups. Nevertheless, no
significant differences existed between the three groups on neuropsychological
measures. CONCLUSIONS: These results indicate that the attention and memory
difficulties reported by PPS sufferers may be linked to the physical or
psychological manifestations of the illness rather than to objective decrements
in cognitive performance.
PMID- 10780630
TI - Cognitive effects of 1- and 20-hertz repetitive transcranial magnetic stimulation
in depression: preliminary report.
AB - OBJECTIVE: To determine the cognitive effects of daily repetitive transcranial
magnetic stimulation (rTMS) administered under the conditions of a treatment
trial for major depression. BACKGROUND: Although daily left dorsal prefrontal
rTMS has improved mood in some patients with treatment-refractory depression,
potential cognitive side effects of extended daily treatment have not been
systematically studied. METHOD: In a randomized double-blind treatment study, 10
subjects (mean age, 42 +/- 15 years) with an episode of major depression received
either 2 weeks of low-frequency (1 Hz) or high-frequency (20 Hz) rTMS (800
pulses, 20 trains over 20 minutes, 80% of motor threshold, 5 days per week) to
the left dorsolateral prefrontal cortex and then were crossed over to the other
treatment condition. Patients received cognitive testing at baseline and after
the first and second weeks of low- or high-frequency rTMS, which was examined by
repeated-measures ANOVA. RESULTS: Of 16 cognitive measures tested after 1 or 2
weeks of rTMS compared with baseline status, none showed deterioration, and the
only significant main treatment effect indicated improvement on a list-recall
test from pre- to post-rTMS after 1 week (p <0.05). CONCLUSIONS: These
preliminary data suggest no gross deleterious cognitive effects of 2 weeks of 1-
or 20-Hz rTMS at 80% of motor threshold over the left prefrontal cortex. Further
cognitive studies of the effects of rTMS at other parameters used in clinical
trials for mood disorders remain to be undertaken.
PMID- 10780631
TI - The motor vehicle collision injury syndrome.
AB - OBJECTIVE: The objective of this study was to examine the central nervous system
changes that may occur after acceleration/deceleration injuries in motor vehicle
accidents. BACKGROUND: Occupants of motor vehicles involved in a collision often
develop a disabling syndrome consisting of head, neck, and back pain; impaired
short-term memory and concentration; fatigue and a loss of stamina; poor balance;
and a change in personality. Injury victims experience a loss of motivation,
emotional lability, and a decrease in libido. The major features of this injury
syndrome are subjective, and there usually are few objective findings on physical
examination. The pathogenesis of this syndrome is poorly understood, but it is
hypothesized that the collision impact produces an inertial strain injury to the
anterior regions of the brain which depresses the functions of the frontotemporal
lobes, at the same time, sensitizing somatosensory neural afferent systems.
Damage to the orbital surfaces of the frontotemporal lobes, in particular,
impairs the gating mechanisms that normally limit sensory input to the brain and
further promotes central sensitization. The psychiatric disorders that emerge in
the wake of these injuries are likely grounded in these pathologic events.
METHOD: The current literature on the biomechanics of head injury and the
associated brain imaging findings in minor head injury are reviewed. A summary of
some of the biochemical sequelae of strain injury to the brain is also provided,
with an emphasis on the changes in energy metabolism and excitatory amino acid
release. CONCLUSIONS: Early intervention to arrest the injury-induced metabolic
cascade, and treatment with agents that activate cerebral metabolism may mitigate
the symptoms of this injury syndrome.
PMID- 10780632
TI - Significance of abnormal brain perfusion in catatonia: a case report.
AB - OBJECTIVE: In this case study, the significance of perfusion abnormalities in
catatonia is examined. BACKGROUND: Recurrent catatonic symptoms are frequently
observed in psychiatric disorders, but the predictors of relapse of the catatonic
symptoms remain unknown. Perfusion abnormalities have been reported during
catatonic states; however, little is known about brain functioning of catatonic
patients during remission. METHOD: A catatonic patient was evaluated by clinical
interview, behavioral examination, and functional neuroimaging (single photon
emission computed tomography) to determine diagnosis and brain perfusion.
RESULTS: The patient exhibited persistent hypoperfusion of the basal ganglia even
after achieving symptomatic remission. CONCLUSIONS: These findings predict a
secondary cause and may predict a chronic course.
PMID- 10780633
TI - Kleine-Levin syndrome and psychosis: observation from an unusual case.
AB - OBJECTIVE: This study evaluated the possible pathologic relation between Kleine
Levin syndrome (KLS) and mood disorders. BACKGROUND: A 28-year-old man with a
remote history of KLS had the sudden onset of a manic episode with psychotic
features after the end of hypersomnolence. METHOD: The patient received an
extensive laboratory examination, including single photon emission computed
tomography and magnetic resonance imaging. RESULTS: Single photon emission
computed tomography showed decreased tracer perfusion in the basal ganglion,
hypothalamus, and right frontotemporal region. Magnetic resonance imaging
revealed a cystic lesion in the pineal region. CONCLUSIONS: Hypothalamic
dysfunction has been described in KLS and mood disorders, but pineal gland
dysfunction has been mentioned only rarely. The clinical and neuroimaging
findings suggest the need for further study of KLS.
PMID- 10780634
TI - Neuropsychological and magnetic resonance imaging abnormalities associated with a
plasmacytoma of the frontal dura: a case report.
AB - OBJECTIVE: The goal of this investigation was to describe the neuropsychological
and magnetic resonance imaging (MRI) findings in a patient with an extramedullary
plasmacytoma that extensively infiltrated the cerebral dura, especially over the
frontal region. BACKGROUND: Extramedullary plasmacytomas are rare tumors that
have been reported to involve the dura matter in only a small number of cases. In
most of the reported occurrences, the dura plasmacytomas were successfully
treated with a combination of surgery and irradiation, without prominent
cognitive sequelae. METHOD: MRI of the brain and neuropsychological tests were
conducted approximately 13 months after the patient underwent radiotherapy. In
addition, measures of frontal lobe personality characteristics were obtained
before and after radiotherapy. RESULTS: MRI findings revealed extensive
enhancement around the anterior frontal lobes and prominent involvement of the
anterior longitudinal fissure. Results from neuropsychological testing indicated
mild to moderately impaired performance on tests of working memory, complex
attention, and cognitive flexibility. Further, the patient reported experiencing
personality changes consistent with frontal lobe dysfunction as part of the
initial symptoms of the disease, which remained unchanged after treatment.
CONCLUSIONS: Our findings are the first to describe cognitive sequelae of dural
plasmacytomas. In addition, results from this case study reveal that
plasmacytomas of the frontal dura produce personality changes similar to those
observed in patients with significant frontal lobe injury. Finally, plasmacytomas
that significantly infiltrate the frontal lobes may be insensitive to
radiotherapy and result in residual cognitive and personality abnormalities.
PMID- 10780635
TI - Hallucinatory experiences at high altitude.
PMID- 10780636
TI - Genetics of growth and reproduction in the turkey. 14. Changes in genetic
parameters over thirty generations of selection for increased body weight.
AB - A line (F) of turkeys was selected over 30 generations for increased 16-wk BW.
The base population for the F line was a randombred control population (RBC2)
that was maintained without conscious selection and used to remove yearly
environmental variation in the F line. Selection was effective in increasing 16
wk BW in the F line. Selection differentials based on the mean of selected
parents minus mean of entire population (intended) and intended selection
differentials weighted for number of offspring produced (actual) did not
consistently differ, indicating that natural selection was not significantly
opposing artificial selection. The realized heritability (h2) of 16-wk BW in the
F line, based on the linear regression of the selection response on accumulated
actual selection differentials, declined with selection; the decline appeared to
be slightly different for males than females. For both sexes combined, the
realized h2 was 0.309+/-0.022 (SE), 0.268+/-0.033, 0.242+/-0.026, and 0.254+/
0.007, respectively, for Generations 1 to 10, 11 to 20, 21 to 30, and 1 to 30.
Genetic increases in 16-wk BW in the F line were positively associated with BW at
other ages (8, 20, and 24 wk of age and at 50% production), days from stimulatory
lighting to production of the first egg, and egg weight. Genetic increases were
negatively associated with egg production, intensity of lay (maximum and average
clutch length and rate of lay), and hatch of fertile eggs. There was no
significant relationship between 16-wk BW and total days lost from broodiness or
fertility. The genetic changes in some correlated traits were not consistent in
all generation intervals studied, indicating that the genetic correlation between
the selected trait (16 wk BW) and the correlated trait changed with selection.
PMID- 10780637
TI - Relationships between bilateral asymmetry and tonic immobility reaction or
heterophil to lymphocyte ratio in five breeds of chickens.
AB - Bilateral asymmetry of several morphological traits, tonic immobility reaction,
and leucocyte ratio were studied in hens and cocks from four Spanish breeds of
chickens (Castellana, Buff Prat, Red Villafranquina, and Barred Red Vasca) and an
F2 cross between Castellana and Buff Prat (C x BP - F2). Any two or all three
types of bilateral asymmetry (fluctuating asymmetry, directional asymmetry, and
antisymmetry) occurred together for the same trait in the different breeds. There
was a significant difference in relative asymmetry among breeds (P < 0.05) for
feather and spur lengths in males, and considerable negative heterosis for
relative asymmetry of leg and wing lengths in C x BP - F2 males (-38 and -12%,
respectively). The degree of relative asymmetry varied among traits and was
between 3 and 12 times greater for spur length in males and for wing bay area in
Villafranquina males. There were significant differences among breeds (P < 0.05)
for tonic immobility duration. The duration of tonic immobility was positively
associated with the mean relative asymmetry of all traits in females from the
Villafranquina breed (r = 0.32; P < 0.05), but this finding was not consistent
across the different breeds. No significant difference was found among breeds in
terms of heterophil to lymphocyte ratio. Although there was no significant
association between mean relative asymmetry of all traits and heterophil to
lymphocyte ratio, males from the Villafranquina breed had a positive and
significant relationship between relative asymmetry for wing bay area and
leucocyte ratio (r = 0.34; P < 0.05). These results suggest that relative
asymmetry measures did not provide a general tool to assess fear or stress
susceptibility.
PMID- 10780638
TI - Comparative performance, blood chemistry, and carcass composition of two lines of
Pekin ducks reared mixed or separated by sex.
AB - Male and female Pekin ducks selected (F2 generation) for greater breast muscle
thickness (MT) and an unselected control (C) were used in this study under mixed-
or separated-sex rearing. Ducks in the separated-sex program had significantly
higher body weights than the birds in the mixed-sex program. The ducks selected
for greater breast muscle thickness exhibited superior (P < 0.05) body weight up
to 42 d of age. Males from the MT line reached market weight at 6 wk, but the
breast muscle thickness, measured by ultrasound scanning, improved significantly
from 6 to 7 wk of age. Males had greater (P < 0.05) breast muscle thickness than
females. At both ages and for both sexes, the MT line had greater (P < 0.05)
breast muscle thickness than the C line. The MT ducks consumed more (P < 0.05)
feed up to 6 wk, but no significant difference was found in cumulative feed
consumption at 7 wk, and the lines did not differ (P > 0.05) in feed:gain ratio.
Males had significantly higher cumulative feed consumption at 6 wk but had a more
desirable (P < 0.05) feed:gain ratio than females at 7 wk. Compared with females
from the C line, MT females had significantly higher carcass yield, higher body
protein, and lower fat. The MT females had higher plasma glucose and lower uric
acid than the C females, but no significant difference was found between the MT
and C lines for plasma triglycerides and total cholesterol. The results of this
study support the utility of ultrasound scanning in duck selection, the separated
rearing of ducklings, and the possibility of reducing the slaughter age of lean
males.
PMID- 10780640
TI - Laying hen behavior. 1. Effects of cage type and startle stimuli.
AB - The well-being of commercial laying hens plays an important role in egg
production. Behaviors such as pacing, displaced preening, increased aggression,
and redirected activities have been associated with stress in poultry. This study
was conducted to determine whether two strains of commercial layers, reported to
differ in level of excitability, behave differently in two types of commercial
cages. DeKalb Delta and Hy-Line W36 hens, 40 to 45 wk of age, were housed six to
eight per cage in open or solid-sided cages, at an equal density between cages.
For each strain, there were six cages per cage type for a total of 24 cages. In
the first five experiments, behavioral data were obtained at a distance of 1 m by
instantaneous or scan sampling. These experiments included hen behavior in both
types of cages with and without the presence of frustrating or startle
conditions. Some significant differences in behavior existed within experiments
but not consistently among all experiments. Sampling method did not affect
reliability of data collection. Two trials were then conducted to determine
whether the length of time to return to normal activity after a startle stimulus
is influenced by the cage type or strain. In the first startle experiment, DeKalb
hens returned to normal activity more quickly than did Hy-Line hens (P = 0.07);
this strain difference was not found when the experiment was repeated. Cage type
did not appear to affect the behavior of birds adversely, although neither cage
type appeared to confer an advantage. No clear differences were found in behavior
by strain or by strain within cage.
PMID- 10780639
TI - Vitamin E and immune responses of broiler pureline chickens.
AB - Immunological responses of cockerels fed diets containing either 10 or 300 mg/kg
of vitamin E were measured in three commercial broiler nuclear lines designated
as A, B, and C. All cockerels were fed the 10 mg/kg diet to 91 d of age, at which
time half were continued on that diet and the other half were fed a diet
supplemented to contain 300 mg/kg of vitamin E. Sixteen days after feeding the
diets, cutaneous basophil hypersensitivity (CBH), which is an in vivo, cell
mediated immune response, was determined as the increase in toe-web skin
thickness 24 h after an injection with phytohemagglutinin-P (PHA-P). Twenty-two
days after feeding the diets, heterophils and lymphocytes were enumerated. At
this time cockerels were also inoculated intravenously with 0.1 mL of 0.25% SRBC.
The injection with SRBC was repeated 27 d later. Six and 20 d after each
injection, antibody titers were determined. Mercaptoethanol-resistant (IgG) and
mercaptoethanol-sensitive (IgM) antibodies were also measured in the secondary
titers. The ratio of heterophils to lymphocytes increased, and CBH response was
depressed by feeding the higher vitamin E diet. For cockerels of Lines A and B,
the higher level of vitamin E maintained primary and secondary SRBC antibody
levels, whereas for Line C, levels were depressed. The effect of the higher
vitamin E diet on IgG and IgM was also stock-dependent. The enhanced
heterophil:lymphocyte ratio from feeding vitamin E suggests an improved
phagocytic ability of the immune system. Relative asymmetries for toe-web skin
thickness and shank length were similar for the three lines.
PMID- 10780641
TI - Laying hen behavior 2. Cage type preference and heterophil to lymphocyte ratios.
AB - Studies were conducted to determine hen preference for and stress response to
cage type. By using a plywood (1.25 cm) test apparatus with open- and solid-sided
compartments and a plexiglass divider at the entrance for controlling passage,
birds (n = 20) were evaluated as to their choice of compartment after training
and acclimation. For each test, after training, an individual bird was placed in
the start box and given 1 min to acclimate before making a choice. The experiment
was repeated after rotating the apparatus 180 degrees. In Experiment 1, the open
sided compartment was chosen by 45% of the hens, and the solid-sided compartment
by 25% (P = 0.02); 30% chose neither. In Experiment 2, the compartment with open
sides was chosen by 70% of the hens, and that with solid sides was chosen by 15%
(P = 0.004); 15% chose neither. The length of time required to choose one
compartment over the other did not differ in either experiment (P = 0.29; P =
0.76). In Experiment 3, tests were videotaped from 0830 h to 1330 h, and tapes
were scored for time spent in each compartment. Birds were observed to spend more
time in open- compared with solid-sided compartments (P = 0.02). To assess stress
level of birds exposed to each type of enclosure, blood was collected from 24
commercial Hy-Line W36 hens housed long-term in either open (n = 12) or solid (n
= 12) cages, and heterophil:lymphocyte (H:L) ratios were determined. Birds in
solid cages had higher H:L ratios than did birds in open cages (P = 0.02),
indicating a greater stress response. These data would suggest that hens may
prefer greater visual access to their surroundings afforded by open cages.
PMID- 10780642
TI - Physical, chemical, and microbiological changes in the ceca of broiler chickens
subjected to incremental feed withdrawal.
AB - Trials were conducted to determine the effect of feed withdrawal on the weight,
pH, native bacterial flora, and the persistence of Salmonella typhimurium in the
ceca of market-age broilers. Broilers were provided medicated or unmedicated feed
and then were subjected to feed withdrawal for 0 to 24 h in transportation crates
or on litter. After feed withdrawal, broilers were stunned, bled, scalded, and
picked. One cecum from each bird was aseptically removed and weighed. The cecum
was then blended in 20 mL of distilled water, and the pH of the blended
suspension was measured. The number of total aerobes, Enterobacteriaceae, S.
typhimurium, and lactic acid bacteria in the suspension were enumerated on the
appropriate bacteriological media. Results indicated that up to 24 h of feed
withdrawal produced no significant change in cecal weight and that cecal pH
varied by up to 0.3 units during feed withdrawal. There were significant
increases in the population of Enterobacteriaceae during feed withdrawal in
Trials 2 and 3, and there was a significant increase in the population of cecal
aerobes in Trial 3. Feed withdrawal produced significant decreases in the
population of lactic acid bacteria in all trials, but no significant change in
the population of S. typhimurium occurred during feed withdrawal. There were no
significant differences in cecal weight, pH, native bacteria populations, or S.
typhimurium populations between broilers that were subjected to feed withdrawal
on litter or in crates. Findings indicate that feed withdrawal does not always
effectively evacuate the contents of the ceca and that the ceca of broilers
subjected to feed withdrawal can remain a source of foodborne bacterial
pathogens.
PMID- 10780643
TI - Effects of nutritionally balanced and stabilized flaxmeal-based diets on Eimeria
tenella infections in chickens.
AB - Twenty Sex Sal cockerels were randomly assigned to each of eight groups; each of
four nutritionally balanced diets were fed to two groups from 1 d through 4 wk of
age. These diets contained 0, 2, 5, or 10% stabilized flaxseed meal that provided
a calculated 0, 0.45, 1.11, or 2.22% n-3 fatty acids, primarily linolenic acid.
At 3 wk of age, one group of chickens from each diet treatment was infected with
Eimeria tenella and was housed in separate but similar conditions to uninfected
control chickens. At 6 d postinfection, chickens were weighed, bled, killed, and
scored for lesions. No level of dietary flaxmeal tested provided protection
against weight gain depression, increased feed conversion ratios, or lesions. We
concluded that these diets did not protect against E. tenella infection because
levels of linolenic acid were not high enough, and the oxidative potentials were
well suppressed by vitamin E and other stabilizers present.
PMID- 10780644
TI - The use of instructional technology in poultry science curricula in the United
States and Canada: 1. Demographics of technology and software use.
AB - This paper describes a study conducted in recognition of the increasingly
widespread use of computers and the importance of exposure to instructional
technologies in all aspects of poultry science curriculum. The study consisted of
the distribution and analyses of two cross-sectional surveys to gather detailed
information on the use of instructional technology (IT) in poultry science
curricula in the US and Canada. One survey was sent to departments to obtain
profiles of poultry science degree programs and the availability of IT and
general support for its use. A second survey was designed to obtain individual
profiles of faculty use of IT and attitudes toward the use of such technologies.
Information presented in this paper includes basic demographics, estimates of
survey validity, and a cross-section of instructional technologies used in
poultry science education. The survey found that poultry science faculty reported
higher levels of use for some instructional technologies than was expected from
recent reports in the literature for higher education in general. Traditional
technologies were widely used for instruction, but computers and the Internet
were almost as popular. Reasons for the high levels of use may be due to an
increasing user-friendliness of equipment and software applications, as well as
the rapid acceptance over the past 2 yr of computers and Internet technologies
among the general public. Involvement with IT projects appears to be changing
from passive to active, consistent with faculty reports of high interest levels
and active experimentation with technology and software.
PMID- 10780645
TI - The use of instructional technology in poultry science curricula in the United
States and Canada: 2. Factors contributing to the use of instructional
technology.
AB - This paper describes a study conducted in recognition of the increasingly
widespread use of computers and the importance of exposure to instructional
technology (IT) in all aspects of the poultry science curriculum. The study
consisted of the distribution and analysis of two cross-sectional surveys. One
survey was sent to departments to obtain profiles of poultry science degree
programs and the availability of IT and general support for its use. The second
survey was sent to faculty to obtain individual profiles of IT use and of factors
which may influence IT use. Herein are reported the results and analysis of those
factors that are thought to contribute to or limit the diffusion of these media
among poultry science faculty. Analysis consisted of descriptive statistics and
contingency table comparisons using Likelihood Ratio chi-square. Factors that
appear to be most important to faculty use of IT are availability of desired IT
equipment, access to adequate expert assistance, availability of knowledgeable
peers willing to share their experience and expertise, and exposure to concrete
examples and ideas of how to use IT. All of these factors contribute to another
important factor in participation and adoption: making it as easy as possible for
faculty to learn and to use advanced IT methods.
PMID- 10780646
TI - The effects of long-term caging and molt of Single Comb White Leghorn hens on
heterophil to lymphocyte ratios, corticosterone and thyroid hormones.
AB - Two commercial strains of 18-wk-old Single Comb White Leghorn (SCWL) hens, HyLine
W-36 and DeKalb XL, were housed six hens per cage in layer cages at two densities
(361 and 482 cm2 per bird) with two replications each per strain and density
combination. The high density treatment contained 24 hens per replication, and
the low density treatment contained 18 hens per replication. Egg production was
measured during the first egg production cycle, a molt (fast) period, and the
first 4 wk of the second lay cycle (20 to 68 wk of age). Blood samples were
obtained from six hens from each replicate in each strain and density combination
(total of 48) at 20, 26, 34, 43, 51, 62, 64, and 68 wk of age. In addition, blood
samples were obtained in a random order from hens in each cage, and the sequence
of sampling was recorded (1 to 6). Blood smears were made, from which heterophil
to lymphocyte ratios (H:L) were determined. Radioimmunoassays were conducted to
determine levels of plasma corticosterone (CS), 3,5,3'-triiodothyronine (T3), and
thyroxine (T4). The results indicated that strain did not affect percentage hen
day egg production (%HDP). Strain and cage density did not affect H:L, T3, T4, or
CS. However, these parameters were affected by bird age, which was related to the
egg production cycle. Plasma CS significantly (P < or = 0.001) increased during
peak %HDP at 26 wk and 64 wk during the molt (fast), and H:L significantly (P <
or = 0.001) increased during the molt (fast) at 64 wk. The sequence in which
blood samples were obtained, from hens within a cage in sampling order, also
increased plasma CS. The CS was significantly (P < or = 0.001) elevated in the
third, fifth, and sixth hens from which blood samples were drawn. Plasma T3 and
T4 changed during the production cycle. The T3 was significantly (P < or =
0.0001) depressed during peak egg production at 26 wk and during the molt (fast)
at 64 wk when compared with the other time periods. Plasma T4 was depressed (P <
or = 0.0001) at 51 wk and was elevated (P < or = 0.0001) at 64 wk during the molt
(fast). The physiological and metabolic parameters of the different hen strains
and cage densities were similar during egg production. However, CS, T3, T4, and
H:L changed with age in relation to the egg production cycle. In addition, the
physiological demands of peak egg production and molt (fast) appeared to be
similar.
PMID- 10780647
TI - Influence of genetic selection for antibody production against sheep blood cells
on energy metabolism in laying hens.
AB - Genetic selection in chickens has been utilized to enhance immune responses that
may influence resistance to diseases. It is important, however, to investigate
the effects of this selection on other physiological processes. Therefore, this
study was conducted to determine whether selection for antibody (Ab) production
against SRBC has an effect on energy metabolism. Laying hens from three lines
were used in this study, two of which were selected for 15 generations for Ab
response against SRBC, and the third was nonselected and randombred. The hens
used were from four different groups. The first two groups were from the lines
that were selected for either high (SH) or low (SL) Ab production. The second two
groups were control birds (nonselected) that had either high (CH) or low (CL) Ab
titers that were similar to those in the SH and SL lines, respectively. The birds
were housed in climate-respiration chambers. Body weights and energy metabolism
were measured. Body weights of SL hens were significantly (P < 0.05) higher than
those of SH hens. However, the BW for the two nonselected groups were similar but
significantly less than the SL group. Energy partitioning was similar in all
groups; however, ME for maintenance for the selected groups (119 kcal x kg(-0.75
x d(-1)) was numerically, but not significantly (P < 0.09), higher than that of
the nonselected groups (112 kcal x kg(-0.75) x d(-1)). These results suggest that
divergent selection for Ab may result in an increase in the requirements of
energy for maintenance, which is not directly related to the amount of Ab
produced. Furthermore, these results support previous findings of the presence of
a negative correlation between BW and the levels of Ab in selected lines.
PMID- 10780648
TI - Protein and energy evaluation of soybean meals processed from genetically
modified high-protein soybeans.
AB - A conventional and two genetically modified soybean samples were processed to
dehulled soybean meal (SBM) at a pilot plant and were compared with SBM from a
commercial processing plant. Crude protein levels (%) of the experimental SBM
samples were M700, 52.5; M702, 53.4; and M703, 62.7. The commercial SBM sample
(UI) contained 47.5% protein. Amino acid, gross energy, lipid, and fiber analyses
were carried out, and true metabolizable energy and true amino acid digestibility
were determined with adult cecectomized cockerels. Digestible Lys, Met, Cys, Thr,
and Val, and also TMEn, were higher (P < 0.05) and NDF, fat, and phospholipids
were lower in M703 than in the other SBM samples. The results of this study
indicate that M703 has considerable advantages over conventional SBM as a feed
ingredient for broiler chickens.
PMID- 10780649
TI - Nutritional value of enzyme- or sodium hydroxide-treated feathers from dead hens.
AB - Two feather digestion processes to remove the feathers from the carcasses of dead
hens were evaluated for their impact on the nutritional quality of the resulting
feather meal. There were three treatments: control (untreated feathers), a
feather-digesting enzyme, and NaOH treatment. Both enzyme- and NaOH-treated
feathers were easily separated from the hen carcasses. The CP level of enzyme
treated feathers after autoclaving (49.90%) was significantly less than the
control and NaOH-treated feathers (94.48 and 87.31%, respectively) because of
elevated ether extract levels resulting from skin and abdominal fat release
during the 12-h enzyme incubation. Before autoclaving, pepsin digestibilities of
enzyme- and NaOH-treated feathers were significantly higher than the control.
However, after autoclaving, no significant difference was found in pepsin
digestibility between the control and enzyme treatments or control and NaOH
treatments. The typical limiting amino acids, methionine, lysine, and histidine,
in feathers were present at greater levels in the resulting enzyme-feather meal
(E-FM) compared with the NaOH-feather meal (N-FM) or control-feather meal (C-FM)
on a percentage of CP basis. Cystine levels, however, were significantly lower in
the E-FM and N-FM compared with that of the C-FM. In chick bioassays, no
significant differences were found in protein efficiency ratio (PER) and net
protein ratio (NPR) among C-FM, E-FM, and N-FM. The AMEn of E-FM (4.52 kcal/g)
was significantly higher than the C-FM (3.58) or N-FM (2.79). These findings
indicated that although enzyme treatment could improve the nutritional quality of
feathers from dead hens, NaOH treatment was a more rapid means of separating
feathers from the carcass.
PMID- 10780650
TI - The effects of various dietary levels of phytase and available phosphorus on
performance of laying hens.
AB - Data previously obtained from our laboratory indicated that addition of 300 U of
phytase/kg diet supported optimal long-term performance of laying hens (20 to 70
wk) fed a corn-soybean meal (SBM) diet containing 0.10% available phosphorus
(AP). Our primary objective was to determine if a phytase level lower than 300
units/kg is adequate for a commercial strain of Single Comb White Leghorn laying
hens (n = 504) fed a corn-SBM diet containing no supplemental P (0.10% AP).
Dietary treatments consisted of the corn-SBM basal diet (0.10% AP, 3.8% Ca, and
17% CP) supplemented with 0, 100, 200, 250, or 300 U of phytase/kg, 0.05%
inorganic P (0.15% AP), and a positive control diet containing 0.45% AP. Each of
the seven dietary treatments was fed to six replicate groups of 12 hens from 20
to 60 wk of age. No significant differences in performance were observed among
treatments during the first 8 wk of the experiment. By 28 wk of age, the 0.10% AP
diet, with no supplemental phytase or P, resulted in significantly lower (P <
0.05) egg production and body weight compared with all other dietary treatments.
Feed consumption, feed efficiency, and egg yield were subsequently depressed by
32 wk of age in hens fed the 0.10% AP diet. No other significant differences
among treatments were observed for performance averaged over the entire 40-wk
experimental period. The mean daily AP intake of hens fed the 0.15% AP, 0.45% AP,
and 0.10% AP + phytase diets was 155, 474, and 103 mg, respectively. The results
of this study indicate that phytase improves the utilization of P in corn-SBM
diets for laying hens and that corn-SBM diets containing 0.10% AP + 100 units of
phytase/kg diet or 0.15% AP supported egg production performance that was not
significantly different (P > 0.05) from that of hens fed a corn-SBM diet
containing 0.45% AP.
PMID- 10780651
TI - Effects of dietary vitamin E on the quality of table eggs enriched with n-3 long
chain fatty acids.
AB - Because of the proposed cardioprotective benefits of n-3 fatty acids and vitamin
E, a trial was carried out to investigate the possibility of enriching eggs with
n-3 fatty acid and vitamin E added to the hen's diet. One hundred ninety-two Hy
Line Brown hens, 39-wk-old, were divided into eight groups: four groups received
the basal diet supplemented with 3% lard and four doses of dl-alpha-tocopheryl
acetate (0, 50, 100, and 200 ppm), whereas the diets of the other groups were
supplemented with 3% of fish oil and the same doses of vitamin E. The
performances of the hens and egg weights were not affected either by the type of
lipid supplement or by the vitamin level. The treatment with fish oil caused a
dramatic increase (P < 0.01) of all n-3 fatty acids of the yolk, particularly EPA
(19.53 vs. 0.74 mg/egg) and DHA (143.70 vs. 43.66 mg/egg), and an appreciable
decrease of arachidonic acid (25.54 vs. 67.72 mg/egg). The different levels of
dietary vitamin E slightly affected the fatty acid composition of the yolk. Yolk
alpha-tocopherol increased linearly as dietary dl-alpha-tocopheryl acetate
increased (P < 0.01) from the control level of 90.93 microg/g of yolk to 313.84
microg/g of yolk when 200 ppm were added to the hen diets. Twenty-eight days of
storage at room temperature (20 to 25 C) did not alter the yolk fatty acid
profile, and, moreover, the levels of vitamin E remained still very close to
those observed in fresh egg.
PMID- 10780652
TI - Body composition and development measured repeatedly by computer tomography
during growth in two types of turkeys.
AB - Distribution and development of fat, muscles, and bone were studied repeatedly by
computer tomography from 4 to 17 wk of age in two commercial strains of turkeys
(BUT-9 and Nicholas) of both sexes. Generally, the proportion of total fat and
meat increased and bone decreased significantly throughout the experimental
period for both strains and sexes. When compared at the same age or body weight,
BUT-9 tended to have a higher percentage of meat than did Nicholas (0 to 3
percentage units). From 8 to 17 wk of age, Nicholas showed higher fat percentage
and lower bone percentage than BUT-9. Based on this study, regardless of weight
at slaughtering, BUT-9 should be preferred. Because males had a significantly
higher body weight gain and higher percentage of meat from 8 wk of age, males
should be used in production to fit the market for high slaughter weights with
large pieces of meat. Because females had a higher meat percentage at young ages
compared with males, but showed an earlier fattening and lower weight gain,
females should preferably be slaughtered at lower live weights. Computer
tomography can be considered an appropriate but expensive method to study body
composition and development in turkeys.
PMID- 10780653
TI - The characterization and incidence of pale, soft, exudative turkey meat in a
commercial plant.
AB - Pale, soft, exudative (PSE) turkey meat is a growing problem for industry and has
been associated with rapid postmortem pH decline and loss of protein
functionality, similar to PSE pork. This study was designed to estimate the
incidence of PSE meat in a commercial plant and use response surface methodology
to characterize the relationship between pH, lightness (L* value), and water
holding capacity (WHC). One hundred thirty-four turkey breast fillets were
selected from the processing line so that 67 had normal color (lightness), and
the other 67 were more pale than normal. Fillets were analyzed at time of
deboning (1.5 h postmortem) and at 24 h postmortem for color (L* value), pH, drip
loss, expressible moisture, and temperature. Additionally, L* values were
measured on 2,995 turkey breasts from the processing line to determine the
commercial incidence of PSE meat based on color. The pale fillets had
significantly lower pH, greater L* value, and less WHC but equal temperature when
compared with the fillets with normal color. The L* value and pH were correlated
with WHC as measured by expressible moisture, but L* value seems to have more
predictive value. By using the L* value range (>53) from the pale-selected
fillets as an indication of paleness, approximately 40% of the 2,995 fillets
would exhibit poor WHC. These results suggest that PSE meat can represent a
significant portion of commercially processed turkey breast meat and that the L*
value measurement could be used to sort turkey meat so that PSE type meat could
be used in specialized formulations.
PMID- 10780654
TI - Influence of the level and location of contamination on the multiplication of
Salmonella enteritidis at different storage temperatures in experimentally
inoculated eggs.
AB - Prompt refrigeration to temperatures capable of restricting microbial growth has
been recommended as an approach to reducing the likelihood that contaminated eggs
will transmit Salmonella enteritidis to humans. By using experimentally
contaminated egg components, the present study determined the extent to which
small numbers of S. enteritidis could grow to more dangerous levels at different
temperatures over a period up to 3 d. This model was intended to simulate the
potential opportunities for S. enteritidis multiplication following oviposition
and prior to the achievement of internal temperatures able to prevent further
microbial growth in eggs. At a relatively warmer incubation temperature (25 C)
and with higher inoculum doses (150 cells), rapid and substantial S. enteritidis
multiplication often occurred, especially when the bacteria had an opportunity
for access to yolk nutrients and when contaminated eggs were incubated for 2 or 3
d before sampling. Extensive multiplication of S. enteritidis was less frequently
observed at lower inoculum doses (15 cells), shorter storage times (1 d), and
lower temperatures (10 to 17.5 C) and when contaminants were introduced into the
albumen.
PMID- 10780655
TI - Plasma 17beta-estradiol levels and ovarian interstitial cell structure in
embryonic Japanese quail.
AB - Plasma concentrations of 17beta-estradiol (E2) and left ovarian histology were
investigated by light and electron microscopy in female Japanese quail from Day
10 of embryonic development through Day 7, posthatch. Plasma E2 levels remained
relatively constant (102 to 140 pg/mL) in the embryo followed by a sharp decrease
posthatch (47 to 70 pg/mL). Beginning on Day 10 of incubation, cells in the
medullary portion (medullary cell; MC) of the left ovaries exhibited
ultrastructural evidence of steroidogenic capability. The MC had numerous lipid
droplets in close proximity to the smooth endoplasmic reticulum (SER).
Mitochondria were also observed in the vicinity of the lipid droplets and SER. On
Days 10 and 12, the cristae of the inner mitochondrial membranes were of a
lamellar configuration; the cristae of some mitochondria in MC had a tubular
appearance by Day 14. These data document relative ontogenic changes in ovarian
morphology and plasma E2 levels during the early developmental period in female
Japanese quail. These data further support the role of this steroid in sexual
differentiation.
PMID- 10780656
TI - Identification of epididymal stones in diverse rooster populations.
AB - The epididymal region of the male reproductive tract is essential for sperm
maturation, and dysfunction of this region results in infertility. Adult roosters
have been observed to develop epididymal stones and consequently have reduced
fertility. Efferent ductule cysts were first observed in White Leghorn roosters
ages 18 to 26 wk. By 26 wk of age, the cysts had become solid, irregularly
shaped, yellow-green stones primarily containing calcium (48%). The number and
size of stones (9 to 160 microm, largest diameter) increased with age in affected
males. Incidence ranged from 0 to 94% within rooster flocks surveyed. Stones have
also been observed in broiler breeder roosters. Histological analysis of Leghorn
and broiler breeder reproductive tracts revealed chronic inflammation with
abundant interstitial mononuclear cell infiltrates. The normal, highly folded
structure of efferent ductules was replaced by a thin, eroded epithelial layer
with few luminal sperm. Abnormal areas were found interspersed with normal areas
of epithelium. Broiler breeder male fertility trials demonstrated that birds with
stones compared with normal males had reduced fertility following both natural
mating (24.8+/-10.5% vs. 66.1+/-7.2%) and artificial insemination (47.8+/-16% vs.
82.0+/-6%). At 62 wk of age, testis weight (14.2+/-1.4 g vs. 20.5+/-1.2 g), daily
sperm production (8.1+/-1.3 x 10(8) vs. 12.3+/-0.8 x 10(8) sperm per testis per
day), and circulating testosterone concentrations (0.9+/-0.3 vs. 2.6+/-0.4 ng/mL)
were all significantly reduced in males with stones. In conclusion, we are
reporting a new dysfunction of the rooster reproductive tract that affects
diverse bird populations and decreases fertility.
PMID- 10780657
TI - Parathyroid hormone receptor binding property in the shell gland of oviduct of
the guineafowl during an oviposition cycle.
AB - Parathyroid hormone (PTH) receptor binding property in the membrane fraction of
the endometrium of the shell gland (uterus) of the guineafowl was analyzed by the
use of [125I]PTH-related peptide (PTHrP) binding assays. Specificity,
reversibility, and saturation of binding were demonstrated. Scatchard plots
revealed a single class of binding sites. The equilibrium dissociation constant
(Kd) was 0.50 to 1.15 nM in laying birds and 1.07 to 1.16 nM in nonlaying birds.
The maximum binding capacity (Bmax) per milligram of membrane protein was 65.2 to
110.9 femtomoles (fmol) in laying birds and 105.8 to 120.6 fmol in nonlaying
birds. Both Kd and Bmax values changed within the above range during an
oviposition cycle in laying birds, showing a decrease during the period of
eggshell formation. No change was found in nonlaying birds. The results suggest
that PTH/PTHrP receptors are present in the shell gland of the guineafowl, and
their binding may be related to eggshell formation.
PMID- 10780658
TI - Extraction and quantification by ELISA of eggshell organic matrix proteins
(ovocleidin-17, ovalbumin, ovotransferrin) in shell from young and old hens.
AB - The eggshell matrix is mainly composed of proteins that are thought to influence
shell formation and calcification and, thus, modify the resulting properties of
the shell. We investigated the potential of some of these proteins as biomarkers
of eggshell quality by developing a competitive indirect ELISA for quantifying
ovotransferrin, ovalbumin, and ovocleidin-17 in eggshell extract. Eggshell
fragments were demineralized in acetic acid (20%) and freeze-dried. The micro
extraction yield was markedly increased (>50%) when Tween 20 was added to the
subsequent extraction and dialysis milieus. Microplates were coated with
ovotransferrin and ovalbumin in a 0.1M carbonate-bicarbonate buffer, but
ovocleidin-17 was fixed with acetone (-20 C, 20 min). Optimal dilutions of the
monoclonal (ovotransferrin) and polyclonal (ovalbumin and ovocleidin-17)
antibodies were 1/3,000, 1/25,000 and 1/4,000, respectively. The inhibition
curves were optimized by preincubating the antibodies and proteins overnight. The
intraassay coefficient (<5%), parallelism of the standards and samples curves,
and recovery (101%) were satisfactory for ovotransferrin. Measurements of
ovalbumin were less precise because of higher interassay variation and
differences between the slopes of standard and sample inhibition curves.
Ovocleidin-17 assays showed similar slopes for standard and eggshell extracts.
Although the total protein in soluble matrix extracts was not affected by age,
the concentrations of these proteins were higher in eggshell extracts from older
hens compared with those from young hens: 1.98x for ovotransferrin, 1.86x for
ovalbumin, and 1.58x for ovocleidin-17. The quantification of specific eggshell
matrix proteins in shell of differing quality is, therefore, a promising tool for
analyzing the origin of eggshell faults and may provide useful information for
breeding programs.
PMID- 10780659
TI - Identification of some components of basal lamina of avian ovarian follicle.
AB - Experiments were conducted to identify components of the basal lamina of the
ovarian follicle. Pure and intact basal lamina was isolated from preovulatory
follicles of the chicken ovary. Some components of the basal lamina could be
solubilized with guanidine-HCl (designated Fraction 1) and remaining components
with beta-mercaptomethanol containing guanidine-HCl (designated Fraction 2). With
Western blot analysis, monoclonal and polyclonal antibodies raised against avian,
mammalian, and human proteins recognized proteins in Fractions 1 and 2 of
solubilized basal lamina. Thus, antibodies raised against extracellular matrix
proteins, laminin, fibronectin, entactin or nidogen, tenascin, heparan sulfate
proteoglycan, osteonectin, and Type IV collagen reacted positively with basal
lamina proteins. Antibodies raised against the growth factors; epidermal growth
factor; acidic and basic fibroblast growth factors; platelet-derived growth
factor-AA; transforming growth factor-alpha; transforming growth factor-beta1,
beta2, -beta3, and -beta5; and insulin-like growth factor-I and -II cross-reacted
with basal lamina proteins. Similarly, antibodies raised against insulin-like
growth factor-binding proteins-2, -3, -4, -5, -6, and -7 cross-reacted with basal
lamina proteins. In addition, antibodies generated against matrix
metalloproteinases-1, -2, -3, -4, -8, -9, and -13 reacted positively with basal
lamina proteins. Furthermore, antibodies produced against tissue inhibitors of
matrix metalloproteinases-1, -2, -3, and -4 also reacted positively with basal
lamina proteins. Moreover, interleukin-3, granulocyte macrophage-colony
stimulating factor, interferon-gamma antibodies recognized proteins in basal
lamina. These observations are consistent with the view that the basal lamina of
avian ovarian follicle is a store or source of biologically active molecules,
namely growth factors, growth factor-binding proteins, cytokines, matrix
metalloproteinases, and their tissue inhibitors. The growth factors could exert
major effects on ovarian cell behavior and function, and the enzymes could
participate in tissue remodeling during follicular development.
PMID- 10780660
TI - Morphometric and mechanical properties of femora in young adult male turkeys with
and without femoral fractures.
AB - Morphologic and torsional mechanical properties of femora were evaluated in three
groups of turkeys to determine whether turkeys that incurred femoral fracture
have different radiographic, morphologic, and torsional mechanical properties
than do turkeys without femoral fracture, and if body weight was a factor
differentiating affected and nonaffected turkeys. Nine turkeys with unilateral
femoral fractures and nine turkeys without fractures from Farm A were compared
with a group of nine age and genetically matched turkeys from Farm B. Turkeys
from Farm A were 10 to 25% heavier (26.2+/-0.9 kg) and turkeys from Farm B were
10% lighter (18.2+/-0.9 kg) than expected breed standards. Femoral length,
cortical thickness, medullary diameter, and diaphyseal curvature were measured
from craniocaudal and lateromedial radiographs. One intact femur from each of
five turkeys with a contralateral femoral fracture (Farm A), nine unaffected
turkeys from Farm A, and nine turkeys from Farm B were subjected to failure in a
torsion test. Geometric and mechanical results were compared. Turkeys from Farm A
had a thicker cortex and a smaller medullary diameter than turkeys from Farm B.
Turkeys from Farm A had significantly lower torsional stiffness and failure
torque values compared with turkeys from Farm B, when differences in body weight
were accounted for (analysis of covariance, P < 0.05). Mechanical failure torque
calculated from geometric values suggests that organic or inorganic material
arrangement and composition may be responsible, in part, for differences between
groups. Femoral fractures may be associated with insufficient skeletal adaptation
to heavy body weight.
PMID- 10780661
TI - Release and complex formation of soluble VEGFR-1 from endothelial cells and
biological fluids.
AB - One of the key molecules promoting angiogenesis is the endothelial cell-specific
mitogen, vascular endothelial growth factor (VEGF or VEGF-A), which acts through
two high-affinity receptor tyrosine kinases (VEGFR), VEGFR-1 (or Flt-1) and VEGFR
2 (or KDR/Flk-1). It was shown before that a soluble variant of VEGFR-1 (sVEGFR
1) can be generated by differential splicing of the flt-1 mRNA. This soluble
receptor is an antagonist to VEGF action, reducing the level of free, active VEGF
A, and therefore, plays a pivotal role in the generation of vascular diseases
like pre-eclampsia or intra-uterine growth retardation. Here we show that sVEGFR
1 is produced by cultured human microvascular and macrovascular endothelial cells
and a human melanoma cell line. The soluble receptor is mainly complexed with
ligands; only 5-10% remains detectable as free, uncomplexed receptor protein.
Furthermore, we show the time course of total and free sVEGFR-1 release together
with its putative ligands, VEGF-A and placenta growth factor (PIGF), from
macrovascular endothelial cells. The release of sVEGFR-1 was quantitatively
measured in two different ELISA types. The release of sVEGFR-1 was strongly
enhanced by phorbol-ester (PMA); the cells produced up to 22 ng/ml of sVEGFR-1
after 48 hours. The expression of VEGF-A and PIGF was moderately influenced by
PMA. We also show a hypoxia-induced increase of sVEGFR-1 expression in cells
cultured from placenta, a tissue that has a high flt-1 gene expression. Moreover,
we demonstrate that sVEGFR-1 in amniotic fluids acts as a sink for exogenous
VEGF165 and PIGF-2. Here, for the first time, to what extent recombinant ligands
have to be added to compensate for the sink function of amniotic fluids was
analyzed. In conclusion, human endothelial cells produce high levels of sVEGFR-1,
which influences the availability of VEGF-A or related ligands. Therefore, sVEGFR
1 may reduce the ligand binding to transmembrane receptors and interfere with
their signal transduction.
PMID- 10780662
TI - Association of plectin with Z-discs is a prerequisite for the formation of the
intermyofibrillar desmin cytoskeleton.
AB - Plectin is a high-molecular mass protein (approximately 500 kd) that binds actin,
intermediate filaments, and microtubules. Mutations of the plectin gene cause a
generalized blistering skin disorder and muscular dystrophy. In adult muscle,
plectin is colocalized with desmin at structures forming the intermyofibrillar
scaffold and beneath the plasma membrane. To study the involvement of plectin in
myofibrillogenesis, we analyzed the spatial and temporal expression patterns of
plectin in cultured differentiating human skeletal muscle cells and its
relationship to desmin intermediate filaments during this process. Northern and
Western blot analyses demonstrated that at least two different plectin isoforms
are expressed at all developmental stages from proliferating myoblasts to mature
myotubes. Using immunocytochemistry, we show that the localization of plectin
dramatically changes from a network-like distribution into a cross-striated
distribution during maturation of myocytes. Double immunofluorescence experiments
revealed that desmin and plectin are colocalized in premyofibrillar stages and in
mature myotubes. Interestingly, plectin was often found to localize to the
periphery of Z-discs during the actual alignment of neighboring myofibrils, and
an obvious cross-striated plectin staining pattern was observed before desmin was
localized in the Z-disc region. We conclude that the association of plectin with
Z-discs is an early event in the lateral alignment of myofibrils that precedes
the formation of the intermyofibrillar desmin cytoskeleton.
PMID- 10780663
TI - In vivo detection of ultraviolet photoproducts and their repair in purkinje
cells.
AB - We previously developed a highly sensitive method to assess in situ repair
kinetics of ultraviolet (UV)-induced DNA photoproducts in epidermal cells using
monoclonal antibodies specific for cyclobutane pyrimidine dimers (CPDs) and
pyrimidine-pyrimidone (6-4) photoproducts (64PPs) by immunohistochemistry. In
order to determine whether nucleotide excision repair capacity is operative in
postmitotic mature neurons, brain surfaces of adult mice were exposed to UVB, and
induction and removal of CPDs and 64PPs in Purkinje cell DNA were assessed
immunohistochemically. UVB penetrated brain tissue to a depth sufficient to allow
quantitative study. CPDs but not 64PPs were clearly detectable in the nuclei of
Purkinje cells at doses >500 J/m2, in a dose-dependent manner. A time course
experiment showed a statistically significant decrease of CPDs with time after
irradiation. Although there was no apparent removal on Day 1, about half of CPDs
were removed within 5 days, and the repair was essentially completed by Day 10.
We conclude that non-dividing cerebellar neuronal cells can indeed repair UV
induced DNA damage, but with relatively low efficiency as compared with dividing
epidermal cells.
PMID- 10780664
TI - CD4+ T cell-mediated cytotoxicity toward thyrocytes: the importance of Fas/Fas
ligand interaction inducing apoptosis of thyrocytes and the inhibitory effect of
thyroid-stimulating hormone.
AB - The accumulation of activated CD4+ T cells and antigen (Ag)-dependent cellular
interactions between thyrocytes and CD4+ T cells have been determined in thyroid
gland from patients with Graves' disease. The Fas/Fas ligand (FasL) interaction
between antigen-presenting cells and T cells regulates the apoptosis of the
former cells triggered by the latter cells. The inhibition of Fas-mediated
apoptosis in thyrocytes could be a underlying mechanism of hyperplasia of
thyrocytes in patients with Graves' disease. We investigated the potential role
of Fas/FasL interaction between thyrocytes and CD4+ T cells in the induction of
Fas-mediated apoptosis of the former cells induced by the latter cells. The
presence of only a few specific T cells responsive to a putative autoantigen has
hampered the investigation of specific T cell activation toward antigen
presenting cells (APCs). Therefore, we used a superantigen, staphylococcal
enterotoxin B (SEB), to examine specific T cell activation toward thyrocytes in
vitro since it stimulates a large proportion of T cells with particular Vbeta
elements. Spontaneous apoptosis of thyrocytes in culture was not found even in
the presence of various kinds of cytokines. In contrast, a clear induction of Fas
mediated apoptosis by anti-Fas IgM was determined in interferon-gamma (IFN-gamma)
stimulated thyrocytes. In addition, a significant cytotoxicity of purified CD4+ T
cells toward IFN-gamma-stimulated thyrocytes in the presence of SEB was induced,
and the addition of anti-HLA-DR and -DQ monoclonal antibodies (mAbs) or blockade
of the Fas/FasL interaction reduced this cytotoxicity. FasL expression of CD4+ T
cells cocultured with IFN-gamma-stimulated thyrocytes in the presence of SEB was
clearly induced. Furthermore, the addition of mAbs against CD54 and CD58
inhibited both cytotoxicity and FasL expression of CD4+ T cells. The cytotoxicity
of CD4+ T cells toward IFN-gamma-stimulated, SEB-pulsed thyrocytes was markedly
inhibited when we used thyrocytes cultured with IFN-gamma in the presence of
thyroid-stimulating hormone (TSH) as target cells. Our results suggest that 1)
CD4+ T cells were activated by thyrocytes expressing MHC class II molecules in an
SEB-dependent manner and then expressed FasL. 2) These activated FasL+ CD4+ T
cells killed thyrocytes by interacting with Fas on thyrocytes and FasL on
activated CD4+ T cells. The presence of costimulating molecules such as CD54 and
CD58 on thyrocytes was also necessary to generate activated FasL+ CD4+ T cells.
3) Since the actions of thyroid stimulating antibody (TSAb) toward thyrocytes are
similar to those of TSH, one goitrogenic activity of TSAb may, in part, be due to
the inhibitory effect on Fas-mediated apoptosis of thyrocytes triggered by
activated CD4+ T cells.
PMID- 10780665
TI - DMBA-induced mammary pathologies are angiogenic in vivo and in vitro.
AB - We have previously shown that human pre-invasive diseases of the breast are
angiogenic. In addition, normal epithelium from women with coincident or
subsequent invasive breast cancer is more vascular than normal epithelium from
women with no breast cancer. To develop a model in which to study the regulation
of angiogenesis in pre-invasive mammary pathologies, we examined 7,12
dimethylbenz[a]anthracene (DMBA)-induced rat mammary tissues for the presence of
neovascularization in pre-invasive histopathologies. These studies included
morphometric analysis of tissue vascularity in pre-invasive lesions. In addition,
we isolated fresh tumors and histologically normal epithelium (organoids) from
DMBA or vehicle-treated control rats to test their ability to induce endothelial
cell tubule formation in vitro. Finally, we examined tumors for their ability to
produce vascular endothelial cell growth factor. The morphometric studies
documented that with epithelial progression, the ability of individual cells to
elicit angiogenesis increases. The in vitro studies showed that isolated tumors
from these animals stimulate angiogenesis. Furthermore, normal epithelium from
DMBA-treated rats is more angiogenic than epithelium from control animals.
Finally, DMBA-induced tumors produce vascular endothelial growth factor (VEGF)
mRNA, therefore, DMBA-induced mammary tumorigenesis is one model in which to test
the dependency of progression on angiogenesis.
PMID- 10780666
TI - Mutations of the p53 gene in nasal NK/T-cell lymphoma.
AB - Mutations of the p53 tumor suppressor gene are reported in various kinds of
malignancies including lymphomas. However, p53 gene mutations in nasal NK/T-cell
lymphoma have not been reported because most parts of tumors are necrotic and a
small amount of living tumor tissues is available for the molecular study.
Expression and mutations of the p53 gene were examined in the paraffin-embedded
specimens of the nasal lesions from 42 Chinese (Beijing and Chengdu) and Japanese
(Okinawa and Osaka) patients with nasal NK/T-cell lymphoma by the
immunohistochemistry and single strand conformation polymorphism (SSCP) analysis
of polymerase chain reaction (PCR) amplified products followed by direct
sequencing. Thirty single-nucleotide substitution mutations were observed in 20
of 42 cases (47.6%). Among the 30 mutations, 18 were missense (mainly G:C to A:T
transitions), 9 were silent, and 1 was a nonsense mutation. The remaining 2
mutations involved intron 5 and exon 5 terminal points. Abnormal expression of
the p53 protein was also observed in 19 of 42 (45.2%) cases. The incidence was
significantly (4-fold) higher in the cases of Osaka than those in other areas,
although the incidence of p53 mutations in the cases of Osaka was one-half to one
third of those in the other three areas. The results may suggest some racial,
environmental, or lifestyle differences in the cause of nasal tumorigenesis.
PMID- 10780667
TI - An in vitro model for the study of human bone marrow angiogenesis: role of
hematopoietic cytokines.
AB - This study describes a human bone marrow endothelial cell culture in which
endothelial cells are organized into capillary tubes. These endothelial cells
were positive for von Willebrand Factor, expressed CD34, CD31, and L-fucose
residues, took up acetylated low-density lipoproteins, contained Weibel-Palade
bodies, and were ensheathed in a basal lamina (which included laminin beta1, EDa+
and EDb+ fibronectin, and collagen type iv). Pericytes expressing alpha-smooth
muscle (alpha-SM) actin were spatially associated with the capillary tubes and
there was a highly significant correlation between the number of capillary tubes
and pericytes. In this model, basal angiogenesis was found to be vascular
endothelial growth factor (VEGF)-dependent, because neutralization of endogenous
VEGF induced a dramatic regression in the number of tubes. However, the presence
of alpha-SM actin-expressing pericytes in the linings of endothelial tubes
partially prevented the VEGF-neutralized tube regression. We also observed that
nitric oxide production contributed to basal angiogenesis and that upregulation
of nitric oxide increased the number of tubes. Tube numbers also decreased when
antibodies neutralizing the integrin alphavbeta5 were applied to the cultures.
Moreover, addition of any of the hematopoietic cytokines, erythropoietin, stem
cell factor, granulocytic colony stimulating factor, or granulomonocytic colony
stimulating factor induced a highly significant increase in tube formation. When
erythropoietin and granulocytic colony stimulating factor were added, this
increase was larger than the maximum increase observed with VEGF. Thus, we have
described an in vitro model for human bone marrow angiogenesis in which pericytes
and basal lamina matrix were associated with endothelial cells and formed fully
organized capillary tubes. In this model, cytokines known to regulate
hematopoiesis also seemed to be mediators of angiogenesis. This culture system
may therefore prove to be a valuable tool for the study of hematopoietic
cytokines on angiogenesis.
PMID- 10780669
TI - Ras signaling is involved in the expression of Fas-L in glioma.
AB - Fas-L expresses on a variety of tumors and is suspected to modify the dialog
between tumor and the immune system. However, the cellular abnormality in tumor
cells leading to an aberrant expression of Fas-L is unclear. In this study, we
demonstrate the involvement of Ras signaling in the Fas-L expression in several
ways. First, the activated Ha-rasval12 gene enhanced the Fas-L expression of
primary human glial cells. Second, blocking the Ras signal pathway in glioma
cells by lovastatin or the Ha-rasAsn17 dominant-negative mutant gene resulted in
reduced Fas-L expression. Transfection of the Ha-rasAsn17 into glioma cells also
inhibited the activation of NFKB, which is a downstream component of Ras
signaling. Accordingly, the membrane-permeable NFKB competitor suppressed the Fas
L expression. Furthermore, the Fas-L expression coincided with the Ras activity
in the murine 212 cells, in which the Ras activity could be induced by isopropyl
3-D-thiogalactoside. In summary, these results suggest that the enhanced Ras
signaling with consequential NFKB activation, which is a frequent defect found in
tumors, could mediate the Fas-L expression of tumors.
PMID- 10780668
TI - Myocyte death in streptozotocin-induced diabetes in rats in angiotensin II-
dependent.
AB - To determine whether myocyte death and angiotensin II (AT II) formation are
implicated in the development of diabetic cardiomyopathy, rats were injected with
streptozotocin, and apoptosis and necrosis were measured at 3, 10, and 28 days.
Expression of the components of the renin-angiotensin system (RAS) and AT II
levels were assessed at 3 days. The percentage of AT II-labeled myocytes and the
number and distribution of AT II sites in myocytes were measured at 3 and 10
days. The effects of AT1 blockade on local RAS and cell death were examined at 3
days. Diabetes was characterized by myocyte apoptosis that peaked at 3 days and
decreased at 10 and 28 days, in spite of high concentrations of blood glucose.
Cell necrosis was absent throughout. Angiotensinogen, renin, and AT1 receptor
increased in myocytes from diabetic rat hearts, while angiotensin-converting
enzyme and AT2 remained constant. AT II quantity increased severalfold, as did
the fraction of AT II positive cells and the number of AT II sites per myocyte.
However, AT II labeling decreased at 10 days, which paralleled the reduction in
myocyte death. AT1 antagonist inhibited upregulation of this receptor and
angiotensinogen, which prevented AT II synthesis and myocyte death at their peaks
with diabetes. An aggregate 30% myocyte loss and a 14% increase in the volume of
viable cells were found in diabetic rats at 28 days. Thus diabetic cardiomyopathy
may be viewed as an AT II-dependent process in which that peptide plays a
critical role in myocyte death and hypertrophy.
PMID- 10780670
TI - Evidence for keratinocyte immortalization in high-grade squamous intraepithelial
lesions of the cervix infected with high-risk human papillomaviruses.
AB - In this study, we demonstrate that expression of cyclin B protein is up-regulated
and persists into the upper epithelial layers in parallel with cyclin A
expression in high-grade squamous intraepithelial lesions (SIL) infected with
human papillomaviruses 16, 31, 33, 51, 58, 66, and 67 (n = 33). In contrast, low
grade SIL infected with human papillomaviruses 16, 18, 31, 33, 39, 51, 52, 56,
58, and 66 (n = 27) show weaker cyclin B expression confined to basal and
parabasal cells despite extension of cyclin A and Ki67 expression into
superficial cells. Moreover, aneusomy is present in 20% of the high-grade lesions
but in none of the low-grade lesions. The persistent expression of cyclin B in
high-grade SIL, and the restriction of aneusomy to high-grade SIL suggest that
there is cell cycle progression. In combination with in vitro studies, this
provides evidence that high-grade SIL lesions have undergone immortalization.
PMID- 10780671
TI - Regulation of vascular growth and regression by matrix metalloproteinases in the
rat aorta model of angiogenesis.
AB - Matrix metalloproteinases (MMPs) have been implicated in the formation of
microvessels during angiogenesis, but their role in vascular regression is poorly
understood. The rat aorta model of angiogenesis was used to study the function of
MMPs at different stages of the angiogenic process. Gelatin zymography and
Western analysis demonstrated production of MMP-2 and MMP-9 by aortic outgrowths
in serum-free collagen gel culture. MMP-2 was found in both culture medium and
collagen gel, whereas MMP-9 was predominantly associated with the gel. MMP
expression increased gradually during the angiogenic growth phase and stayed high
when vessels regressed and collagen lysed around the aortic rings. The MMP
inhibitors, batimastat and marimastat, blocked formation of microvessels when
added to the culture medium at the beginning of the experiment. They, however,
stabilized the microvessels and prevented vascular regression after the
angiogenic growth phase. This effect was observed also under conditions of
angiogenic stimulation by basic fibroblast growth factor. MMP inhibitor-mediated
stabilization of microvessels was associated with inhibition of collagen lysis
and accumulation of collagen fibrils in the subendothelial space. This study
demonstrates that MMPs promote microvessel formation during the early stages of
angiogenesis, but also contribute to the reabsorption of the neovasculature in
the later stages of this process. The time-dependent divergent effects of MMPs on
microvessel growth and survival may influence the in vivo activity of MMP
inhibitors used to treat angiogenesis-dependent disorders.
PMID- 10780672
TI - Development of intermediate-grade (mantle cell) and low-grade (small lymphocytic
and marginal zone) human non-Hodgkin's lymphomas xenotransplanted in severe
combined immunodeficiency mouse models.
AB - We have used severe combined immunodeficiency (SCID) (c.b.-17, ICR/SCID) mice to
develop xenotransplantation (XT) models for human intermediate-and-low-grade non
Hodgkin's lymphomas (NHL). In the past, SCID mice have provided a variety of
useful XT models for human hematopoietic neoplasms that primarily involve the
acute leukemias and some nonhematopoietic tumors, but only rare reports exist on
use of the SCID mouse model in the study of primary tumor cells from NHL.
Intermediate-grade and low-grade NHL are the most common lymphomas seen in
adults. There is no effective therapy for those types of NHL, and they have not
been established in an animal model to date. The lack of an animal model has
hampered studies that can evaluate the disease process in vivo as well as the
definition of therapeutic parameters involved in treatment. We report in this
study that primary patient samples of NHL ( intermediate grade and low grade)
have been successfully established in SCID mice after XT. NHL include
intermediate-grade (mantle cell lymphoma) and low-grade (eg, small lymphocytic
lymphoma/chronic lymphocytic lymphoma and marginal zone lymphoma) forms. Studies
have been directed toward creating appropriate conditions for the optimal
grafting of these NHL in SCID mice so that the disease process in humans could be
accurately simulated. These studies indicate that development of XT-human
lymphoma cells in SCID mice appear to be linked to their biologic and/or clinical
behavior, transplanted lymphoma cell number, and age, as well as to the natural
killer cell status of the SCID mouse recipients. Evidence has also shown that NHL
cells can exhibit homing or trafficking patterns in SCID recipients that resemble
those observed in patients with gastrointestinal lymphomatous involvement
(particularly that of mantle cell lymphoma). Our studies also indicate that
artefactual influences, such as the outgrowth of Epstein-Barr virus-associated
lymphoblastoid lesions, are rare occurrences in the human NHL/SCID models that we
have established.
PMID- 10780673
TI - Two different types of sialoadenitis in the NOD- and MRL/lpr mouse models for
Sjogren's syndrome: a differential role for dendritic cells in the initiation of
sialoadenitis?
AB - Sjogren's syndrome is an autoimmune disease that primarily affects the salivary
and lacrimal glands. In these glands, focal lymphocytic infiltrates develop.
Little is known about the initiation of this autoimmune disease. Antigen
presenting cells (APC) such as dendritic cells (DC) can play a role in the
initiation of autoimmunity. To date, no data on the presence of DC in Sjogren's
syndrome are available. Several mouse strains, the nonobese diabetic (NOD) and
the MRL/Ipr mouse, can be used as models for Sjogren's syndrome. We compared the
development of sialoadenitis in the submandibular glands (SMG) of NOD and MRL/Ipr
mice with particular focus on the presence of APC. DC, macrophages, T cells, and
B cells in the SMG were studied by means of immunohistochemistry, after which
positively stained cells were quantified. NOD-severe combined immunodeficiency
(SCID) mice were used to study the presence of APC in the SMG in the absence of
lymphocytes. Before lymphocytic infiltration, increased numbers of DC were
detected in the SMG of NOD mice compared with those numbers in control mice and
MRL/Ipr mice, which suggests that DC play a role in the initiation of
sialoadenitis in NOD mice. In the SMG of NOD mice, lymphocytic infiltrates
organized in time. In MRL/Ipr mice, however, lymphocytic infiltrates were already
organized at the time of appearance. This organization was lost over time. In
conclusion, two types of sialoadenitis are described in two mouse models for
Sjogren's syndrome. Differences exist with regard to early events that may lead
to the development of sialoadenitis and to the composition and organization of
inflammatory infiltrates. It is possible that different types of sialoadenitis
also exist in humans and that the pathogenetic process in both the early and late
phases of the autoimmune reaction differs among patients.
PMID- 10780674
TI - AAC-11 overexpression induces invasion and protects cervical cancer cells from
apoptosis.
AB - To identify the genes involved in cervical carcinogenesis, we applied the mRNA
differential display (DD) method to analyze normal cervical tissue, cervical
cancer, metastatic lymph node, and cervical cancer cell line. We cloned a 491-bp
cDNA fragment, CC231, which was present in metastatic tissue and cervical cancer
cell line, but absent in normal cervical and cervical cancer tissues. The 491 bp
cDNA fragment has 98% homology to the previously published sequence, AAC-11
(antiapoptosis clone 11). The levels of AAC-11 mRNA expressions in nine normal
cervical and nine primary cervical cancer tissues were low. Its expression was
higher in three metastatic tissues and five cervical cancer cell lines (HeLa,
CaSki, SiHa, CUMC-3, and CUMC-6). Invasion of matrigel and adhesion to laminin by
AAC-11 transfected CUMC-6 cells were increased by approximately 2-fold and 4
fold, respectively. Northern blot analysis showed that matrix metalloproteinase
(MMP)-2 and membrane type 1 MMP (MT1-MMP) genes were found to be expressed in
high levels in AAC-11-transfected cancer cells. But MMP-2 and MT1-MMP were not
expressed in cells transfected with vector alone or wild-type cells. AAC-11
transfected cells expressed an elevated level of MMP-2 protein as assessed by
immunoblotting. On the contrary, tissue inhibitor of MMP (TIMP-2) expression was
detectable in cells transfected with vector alone or wild-type cells,
respectively. Its expression was undetectable in AAC-11 transfected cells. In
cervical cancer cells transfected with AAC-11, the expression of beta-catenin was
up-regulated. These suggest that overexpressions of MMP-2 and MT1-MMP, loss of
TIMP-2 expression, and up-regulation of beta-catenin by AAC-11 transfection may
contribute to the development of cervical cancer invasion. AAC-11 gene
transfection increased cervical cancer cell colonization. The effect of AAC-11 on
cultured cervical cancer cells was associated with antiapoptotic process.
Approximately 50% of the AAC-11 transfected cells in serum-free medium died after
2 weeks, compared to 1 week for vector alone or wild-type cells. These results
suggest that AAC-11 may serve as a candidate metastasis-related and apoptosis
inhibiting gene in human cervical cancer.
PMID- 10780675
TI - Interleukin-8 overexpression is present in pyoderma gangrenosum ulcers and leads
to ulcer formation in human skin xenografts.
AB - Interleukin-8 (IL-8) is a potent chemotactic polypeptide for neutrophils.
However, the role of this cytokine during inflammation remains unclear. Skin
specimens from patients with pyoderma gangrenosum demonstrated IL-8
overexpression in skin ulcers, which suggests a role for IL-8 in the development
of the disease. We therefore constructed a recombinant adenovirus expressing the
complementary deoxyribonucleic acid encoding human IL-8 (IL-8/Ad5) that induces a
2000-fold increase in IL-8 expression of infected human fibroblasts in vitro.
Human skin engrafted to severe combined immunodeficiency mice and then injected
with the recombinant virus demonstrated erythema, an intense perivascular
infiltration of neutrophils, and extravasation of erythrocytes after 8 hours. By
12 hours after injection, neutrophils had accumulated beneath the epidermis,
which then necrotized, and one or more ulcers that remained for approximately 2
weeks were observed. Clinically and histologically, the ulcers resembled pyoderma
gangrenosum. These clinical and experimental findings suggest an etiologic role
of IL-8 in the pathogenesis of pyoderma gangrenosum.
PMID- 10780676
TI - Human dendritic cells in the severe combined immunodeficiency mouse model: their
potentiating role in the allergic reaction.
AB - Dendritic cells (DCs) are present in the lungs and airways of healthy and
allergic subjects where they are exposed to inhaled antigens. After the uptake of
antigens, DCs migrate to lymphoid organs where T cells initiate and control the
immune response. The migratory properties of DCs are an essential component of
their function but remain unclear in the situation of allergic diseases. To
better understand the role of DCs in response to allergens, we first investigated
their presence in an original experimental model of allergic asthma: the
humanized severe combined immunodeficiency (SCID) mouse reconstituted with
peripheral blood mononuclear cells from patients sensitive to Dermatophagoides
pteronyssinus (Dpt). Human DCs were detected in lungs of mice developing an
inflammatory pulmonary infiltrate and appeared to be mainly located in the
alveolar spaces. In a second step, human DCs were generated in vitro from
monocytes and injected into naive SCID mice exposed or not exposed to Dpt
aerosols. Their migratory behavior was explored, as well as their potential role
in modulating the IgE production after exposure to Dpt. After exposure to Dpt,
the number of DCs present in airways decreased, while it increased into the
spleen and thymus of the mice. The IgE production increased in the presence of
DCs as compared with mice not injected with DCs. These results suggest that DCs
may play a role in the pulmonary allergic reaction developed in response to Dpt
in SCID mice.
PMID- 10780677
TI - Three-dimensional organisation of mitochondrial clusters in regenerating dorsal
root ganglion (DRG) neurons from neonatal rats: evidence for mobile mitochondrial
pools.
AB - We report for the first time the rearrangement of mitochondrial arrays in
developing dorsal root ganglion (DRG) neurons isolated from neonatal rats in
culture. Neurons were loaded with the mitochondria-specific fluorescent dye JC-1,
and three-dimensional (3D) reconstruction of mitochondrial fluorescence was
performed by confocal laser sectioning in fresh neurons and neurons kept in
culture up to a week. We found that after 24 hours the mitochondria become
reorganised to form clusters in the axonal hillocks. Axonal extension and
neuronal network formation coincided with a redistribution of the mitochondrial
clusters. In the extended axons the mitochondria become spaced along the axonal
length; however, they formed clusters in the branch points and growth cones. We
conclude that the initial clusters of mitochondria may be storage pools of mobile
mitochondria able to be mobilised to provide energy for axonal transport during
neuronal regeneration and neuronal outgrowth. These findings may have relevance
to the rate of axonal regeneration and axonal transport in adult DRG neurons, and
neuronal polarisation and axonal outgrowth regulation in developing DRG neurons.
PMID- 10780679
TI - Variation in rat sciatic nerve anatomy: implications for a rat model of
neuropathic pain.
AB - We discovered a variation of rat sciatic nerve anatomy as an incidental finding
during the anatomical exploration of the nerve lesion site in a rat neuropathic
pain model. To confirm the composition and distribution of rat sciatic nerve,
macroscopic anatomical investigation was performed in both left and right sides
in 24 adult Sprague-Dawley rats. In all rats, the L4 and L5 spinal nerves were
fused tightly to form the sciatic nerve. However, the L6 spinal nerve did not
fuse with this nerve completely as a part of the sciatic nerve, but rather sent a
thin branch to it in 13 rats (54%), whereas in the remaining 11 rats (46%), L6
ran separately along with the sciatic nerve. Also, the L3 spinal nerve sent a
thin branch to the L4 spinal nerve or sciatic nerve in 6 rats (25%). We conclude
that the components of sciatic nerve in Sprague-Dawley rats vary from L3 to L6;
however, the major components are L4 and L5 macroscopically. This finding is in
contrast to the standard textbooks of rat anatomy which describe the sciatic
nerve as having major contributions from L4, L5, and L6.
PMID- 10780678
TI - Gene expression of antioxidant enzymes in experimental diabetic neuropathy.
AB - Chronic hyperglycemia results in a large deficit in nerve blood flow. Both
autoxidative- and ischemia-induced lipid peroxidation occurs, with resultant
peripheral sensory neuropathy in streptozotocin-induced diabetes in the rat. Free
radical defenses, especially involving antioxidant enzymes, have been suggested
to be reduced, but scant information is available on chronic hyperglycemia. We
evaluated the gene expression of glutathione peroxidase, catalase, and superoxide
dismutase (cuprozinc and manganese separately) in L4,5 dorsal root ganglion (DRG)
and superior cervical ganglion, as well as enzyme activity of glutathione
peroxidase in DRG and sciatic nerve in experimental diabetic neuropathy of 3
months and 12 months durations. We also evaluated nerve electrophysiology of
caudal, sciatic-tibial, and digital nerves. A nerve conduction deficit was seen
in all nerves in experimental diabetic neuropathy at both 3 and 12 months. Gene
expression of glutathione peroxidase, catalase, cuprozinc superoxide dismutase,
and manganese superoxide dismutase were not reduced in experimental diabetic
neuropathy at either 3 or 12 months. Catalase mRNA was significantly increased in
experimental diabetic neuropathy at 12 months. Glutathione peroxidase enzyme
activity was normal in sciatic nerve. We conclude that gene expression is not
reduced in peripheral nerve tissues in very chronic experimental diabetic
neuropathy. Changes in enzyme activity may be related to duration of diabetes or
due to post-translational modifications.
PMID- 10780680
TI - Effect of ischemia and cooling on the response to high frequency stimulation in
rat tail nerves.
AB - In normal rat tail nerves the effect of temperature and ischemia on the response
to long-term high frequency stimulation (HFS) (143 Hz) was studied. The effect of
temperature was studied in two consecutive tests at 14 degrees C and 35 degrees
C. Prior to the HFS the peak-to-peak amplitude (PP-amp) of the compound nerve
action potential was 139 +/- 20 microV (mean +/- SD) and 127 +/- 37 microV at 35
degrees C and 14 degrees C, respectively (NS). After 15 min of HFS the PP-amp was
reduced to 45.3 +/- 20.5% of baseline level at 14 degrees C as compared with 80.8
+/- 10.2% at 35 degrees C (p < 0.001). Applying ischemia to the rat tail, an
additional fall of the PP-amp was seen after 15-20 min of HFS at both low (20 Hz)
and high (143 Hz) stimulation frequencies. In conclusion, ischemia and cooling
result in an impaired ability to transmit high frequency impulses.
PMID- 10780681
TI - Guillain-Barre syndrome occurring in two women after ketoacidosic comatose state
disclosing an insulin-dependent diabetes mellitus.
AB - We report two women who presented with a Guillain-Barre syndrome just after a
ketoacidosic comatose state disclosing an insulin-dependent diabetes mellitus.
One had characteristic clinical signs and the other had major motor involvement.
At neurophysiologic investigations, one had typical demyelinating neuropathy
whereas the second had mainly axonal degeneration. At ultrastructural examination
of a peripheral nerve biopsy, features of macrophage-associated demyelination
were present in both nerve specimens, thus confirming the diagnosis of acute
inflammatory demyelinating polyneuropathy, i.e., Guillain-Barre syndrome.
Prominent axonal involvement was also present in the motor nerves of the second
patient. Insulin therapy had to be permanently continued and these two cases are
quite different from the transient diabetes sometimes observed in certain cases
of Guillain-Barre syndrome. Both the latter and insulin-dependent diabetes
mellitus probably have auto-immune mechanisms. It is likely that in our two
patients both auto-immune diseases were triggered by a common event. Such cases
of Guillain-Barre syndrome have to be distinguished from other acute diabetic
neuropathies.
PMID- 10780682
TI - Pre-, intra-, and postoperative three-dimensional evaluation of adolescent
idiopathic scoliosis.
AB - The authors measured and compared the pre-, intra-, and postoperative three
dimensional shape of the spine during corrective surgery to quantify the specific
contribution of positioning, anesthesia, surgical exposure, surgical
instrumentation, and postural adaptation of the thoracic and lumbar spine. In 58
adolescent girls with idiopathic scoliosis undergoing corrective surgery by a
posterior approach, the three-dimensional geometry of the thoracic and lumbar
spine was documented in the standing position before and after surgery using a
three-dimensional reconstruction technique based on multiplanar radiography, and
the intraoperative three-dimensional geometry was measured using a three
dimensional magnetic digitizer before and after installation of the first rod.
Prone positioning, anesthesia, and surgical exposure are responsible for a
considerable decrease in all curves in the frontal and sagittal plane.
Instrumentation with the first rod produces additional substantial and favorable
three-dimensional changes with partial restoration of the normal sagittal curves
and sagittal shift of the plane of maximum deformity. Although no loss of
correction was observed in the frontal plane when patients resumed their standing
position, a "spring-back" effect on the spine was noted in the sagittal plane and
a loss of three-dimensional correction was seen in the orientation of the plane
of maximum deformity. Surgeons can use the knowledge of these various changes to
achieve better results by more careful attention to the preoperative positioning
of patients and to curve correction in the sagittal plane when instrumentation is
applied to the spine.
PMID- 10780683
TI - A preliminary report on the effect of measured strength training in adolescent
idiopathic scoliosis.
AB - The authors studied 12 adolescent patients with scoliosis (10 girls and 2 boys)
who were 11 to 16 years old and had curvatures ranging from 20 degrees to 60
degrees. Seven were right thoracic curves and five were thoracolumbar with double
curves. When tested on the MedX Torso Rotation Machine, both sides were unequal
in their torso rotation strength all patients. Myoelectric activity was
asymmetric in both sides and in abdominal and paraspinal muscles of all patients.
These asymmetries were corrected completely with torso rotation, which was
associated with significant strength gains. Strength gains ranged from 12% to
40%. A 16-year-old girl with a 60 degree lumbar curve progressed and had surgery.
None of the remaining patients progressed, and 4 of the 12 had decreases in their
curvatures from 20 degrees to 28 degrees. None of the patients used braces during
this study.
PMID- 10780684
TI - Three-dimensional rotations of the thoracic spine after distraction with and
without rib resection: a kinematic evaluation of the apical vertebra in rabbits
with induced scoliosis.
AB - An experimental model of induced scoliosis in New Zealand rabbits was studied to
evaluate the effects of rib resection on the apical vertebra during distraction
for scoliosis surgery. After concave distraction, three-dimensional rotations of
the apical vertebra were measured using a motion analysis system, which included
three cameras and six reflective markers. Distraction with rib resection on the
convexity produced minimal rotations in the coronal plane (0.77 degrees),
sagittal plane (0.96 degrees), and transverse plane (0.61 degrees) compared with
no rib resection. The distraction maneuver with rib resection has no significant
effect on derotation of the apical vertebra in the coronal and transverse plane,
but slightly greater forward rotation was apparent in the sagittal plane (p <
0.05). Resection of three convex ribs directly corrects the rib prominence and
does not seem to improve derotation.
PMID- 10780685
TI - Correlative analysis of the sagittal profile of the spine in patients with beta
thalassemia and in healthy persons.
AB - This prospective study compares several roentgenographic parameters of the
thoracic and lumbar spine in patients with beta-thalassemia and in healthy
persons who served as controls. Eighty-four patients with beta-thalassemia and 84
age- and gender-matched healthy persons were examined clinically and
radiologically (thoracic kyphosis, lumbar lordosis, and vertebral and sacral
inclination). Although there was a significant difference in the vertebral
inclination from T6 to L1, L4, and L5 between patients and controls, thoracic
kyphosis and lumbar lordosis did not differ in the two groups. The apical
vertebra of the thoracic kyphosis in patients and controls was T7 and T6,
respectively, whereas L4 was the apical vertebra of the lumbar lordosis in both
groups. There were no age- or gender-related differences in the magnitude of
sacral inclination, thoracic kyphosis, or lumbar lordosis in the patients with
beta-thalassemia compared with controls. Lumbar lordosis was significantly
correlated with sacral inclination in both patients with beta-thalassemia and
controls. Beta-thalassemia does not affect sagittal profile of the thoracic and
lumbar spine but it is associated by structural changes on the frontal plane of
the spine that are expressed as a high prevalence of scoliosis.
PMID- 10780686
TI - A method for dynamic measurement of lumbar lordosis.
AB - Trunk flexion-extension is accomplished with pelvic and thoracic rotation in the
sagittal plane and a smooth coordination of lumbar vertebral translation and
rotation. Several systems exist that measure gross trunk movements, but they
typically do not track changes in lumbar arc length or curvature. A method for
dynamic measurement of changes in lumbar arc length that uses a lordosimeter is
presented. A static validation study of postures showed that the measurements are
repeatable and compare favorably with a standard measure of lumbar curvature. In
a dynamic validation study of a lifting task with a 23-kg load, the measurement
method was highly correlated with thoracic and pelvic angular displacement. A
discussion of the utility of this measure in biomechanical modeling is presented.
A clinical or field version of the lordosimeter is also described.
PMID- 10780687
TI - Clinical outcome scales for use in a rabbit model of cervical myelopathy.
AB - This study determined the ability of an upper extremity Tarlov scale, a lower
extremity Tarlov scale, and the Durham scale to predict the development of
myelopathy and the likelihood of survival in a rabbit model of surgical
treatments for cervical spondylotic myelopathy. Forty-eight rabbits were
evaluated using the scales after cervical spinal surgery. Logistic regression
analysis revealed that all three scales could predict the occurrence of
myelopathy. However, only the Durham and lower extremity Tarlov scales also
predicted the likelihood of survival. The Durham scale is offered as a useful
predictor of myelopathy and survival in an animal model of surgical treatments
for cervical spondylotic myelopathy. The lower extremity Tarlov scale is also a
useful predictor of outcome; however, the upper extremity Tarlov scale is not
recommended.
PMID- 10780689
TI - Retroperitoneal laparoscopic lateral approach to the lumbar spine: a new
approach, technique, and clinical trial.
AB - A retroperitoneal laparoscopic (retroperitoneoscopic) lateral approach to achieve
decompression for a far lateral disk lesion in the lumbar spine or to remove a
paravertebral neurinoma without disrupting the facet is described. The operating
space is maintained using a powered mechanical lift and a flat inflatable
retractor mainly to make a longitudinal separation between the psoas major and
the quadratus lumborum. This technique has been performed successfully in 22
cases using retroperitoneoscopy. The best indications of this new procedure are
lateral disk herniation at the L5-S1 level or around the conus medullaris at the
L1-L2 level. The described procedure provides adequate exposure necessary for
extraforaminal exploration, discectomy, and nerve root decompression, and it is
sufficient for treating extreme lateral lumbar herniation localized to the L1-S1
level and spinal nerve root tumors.
PMID- 10780688
TI - Factors influencing the outcome of degenerative lumbar spinal stenosis.
AB - The objective of this study was to evaluate the influence of decreased dural sac
cross-sectional area and baseline clinical parameters on the outcome of patients
treated surgically or conservatively for lumbar spinal stenosis. Computed
tomography or magnetic resonance imaging scans of 37 patients were digitized and
the dural sac cross-sectional area was calculated. This parameter and baseline
clinical, socioeconomic, and anthropometric data of the patients were correlated
with 1-year and 2-year follow-up data. The decrease in dural sac cross-sectional
area negatively affected walking capacity on follow-up controls in patients
treated conservatively, whereas such a relation was not observed among surgically
treated patients. Female sex was the main parameter that worsened the global
outcome of degenerative lumbar spinal stenosis, particularly after surgical
treatment.
PMID- 10780690
TI - Use of the anterior interbody fresh-frozen femoral head allograft in
circumferential lumbar fusions.
AB - Many studies in the literature have documented the outcome of circumferential
lumbar fusions. However, no study has specifically evaluated the performance of
the anterior fresh-frozen femoral head allograft as a structural interbody graft
material. All office and hospital records, including charts and radiographs, were
reviewed to obtain pertinent clinical and radiographic information. The cases
included 23 single-level fusions, 22 two-level fusions, and 5 fusions of three or
more levels. In all, 88 fusion levels were analyzed radiographically. The mean
follow-up time was 28 months (range, 24 to 36 months). All procedures were
performed in a single stage. At the latest follow-up, clinical outcome was graded
good to excellent in 39 (78%) cases, fair in 8 (16%) cases, and poor in 3 (6%)
cases. The average time to anterior radiographic fusion was 6 months (range, 4 to
8 months). The overall fusion rate was 98%. The average preoperative anterior
disk space height was 10 mm, 14 mm immediately after operation, and 13 mm at
follow-up. The posterior disk space height averaged 5 mm before operation, 7 mm
immediately after operation, and 6 mm at follow-up. The average segmental
lordosis was 7 degrees before operation, 10 degrees immediately after operation,
and 10 degrees at follow-up. Late postoperative disk space collapse of 3 mm or
more was noted in 17% of the fused disk spaces examined. Seventy-eight percent of
the disk spaces maintained a disk space height greater than that of their
preoperative value at the latest follow-up. Segmental lordosis did not change
significantly at follow-up. The occurrence of collapse did not correlate with the
clinical result, smoking history, or surgical indication (p < 0.05).
Perioperative complications included one pleural effusion, two urinary tract
infections, and one deep wound infection. Late complications included five
painful graft sites and two patients with pseudarthrosis. Fresh-frozen femoral
head allograft fulfills its desired function as an anterior structural graft in
combination with rigid posterior transpedicular fixation, maintaining the disk
space height achieved at surgery while reliably allowing remodeling and
incorporation into a solid anterior fusion.
PMID- 10780691
TI - Biomechanical effect of anterior grafting devices on the rotational stability of
spinal constructs.
AB - In the thoracolumbar spine, frequently strut grafting is used to restore the
anterior and middle column defects. Biomechanical stability of the surgical
construct may be altered significantly depending on the type of anterior grafting
devices. In this study, a biomechanical flexibility test was conducted to compare
the stabilizing role of various types of anterior grafting devices, such as a
polymethylmethacrylate block, tricortical iliac crest bone graft, one large Harms
cage, and two small Harms cages using a calf lumbar corpectomy model. The Harms
cage, especially one large cage, improved the axial rotational stability
significantly in both anterior and posterior fixation groups as compared with the
iliac bone or polymethylmethacrylate. No significant difference in the
stabilizing role was found among different grafting devices in lateral bending,
flexion, and extension. These results suggest that a more rigid spinal construct
can be obtained by using a metal cage with improved friction at the cage-bone
interface.
PMID- 10780692
TI - An experimental approach to spinal fusion using sintered bovine bone in a pig
model.
AB - Sintered bovine bone is a biomaterial based on calcium phosphate, an organized
crystal of bone mineral that possesses a natural trabecular structure. The
authors considered whether sintered bovine bone can integrate with recipient bone
and adjust to the strength of recipient bone for anterior spinal fusion in an
animal model. Either autologous iliac bone or sintered bovine bone was implanted
for a spinal body fusion. Some pigs underwent exposure of the spinal bodies
without implantation. Based on radiographic evaluation, manual palpation,
biomechanical testing, and histologic examination, spinal fusion with sintered
bovine bone resulted in a composition and structure similar to that of the
autograft (or of no implantation). The sintered bovine bone with its moderate
strength tended to adjust to the bone stiffness of the host bone in the specimens
as new bone grew.
PMID- 10780693
TI - The durability of small-diameter rods in lumbar spinal fusion.
AB - The use of a small-diameter rod in lumbar fusion offers a lower hardware profile
and reduced implant bulk. Concern has been raised, however, about the ability of
smaller rods to withstand the cyclic loads placed on them until fusion is
achieved. This study is a retrospective radiographic review designed to evaluate
the durability of a 4.75-mm diameter rod in the early postoperative period before
fusion healing. Examination of postoperative radiographs revealed two instances
of rod failure that occurred more than 24 months after operation among 85 cases
of pedicle screw instrumentation followed for an average of 32 months. Based on
these preliminary data, the benefits of a small-diameter rod can be obtained
without an increased incidence of rod failure during the initial healing period.
PMID- 10780694
TI - Reoperation for spinal restenosis in achondroplasia.
AB - The characteristics of spinal restenosis in achondroplasia and its treatment are
evaluated in this study. Radiologic and surgical findings were correlated to
establish the causes of achondroplastic spinal restenosis and the benefits of its
therapy. Eight patients (five men, three women) with spinal restenotic
complications of achondroplasia were studied. The most common neurological sign
of recurrent stenosis was impaired motor function. The mean interval between the
most recent surgeries was 8.2 years (9.5 years for surgeries at the same levels).
The most common causes of recurrent stenosis were facet hypertrophy and disk
disease. The complications were a dural tear and cerebellar hemorrhage in one
patient and transient neurological deterioration in another. One patient died
after operation. Restenosis can occur many years after original decompression in
the achondroplastic spine, and repeated operation can successfully lessen pain
and neurological symptoms in most patients.
PMID- 10780695
TI - Eccentric compression of the spinal canal causing dominantly contralateral-side
symptoms.
AB - In this retrospective study, five patients are described in whom the dural sac at
the thoracic and lumbar spine was compressed by a herniated disk or stenosis,
located eccentrically in the spinal canal. In all of them, the symptoms or
neurologic findings were dominantly in the limb contralateral to the side of
compression. All five patients were operated on and the compressing disk or
lamina was removed, resulting in immediate improvement of symptoms. In only one
of the patients was the compression at the common level of L4-L5. In the
remaining four patients, compression was at the low thoracic or upper lumbar
spine. With the exception of one patient, the area of canal compression was
greater than 50%.
PMID- 10780696
TI - Prevention of positional brachial plexopathy during surgical correction of
scoliosis.
AB - Continuous intraoperative monitoring of spinal cord function using somatosensory
evoked potentials (SSEP) has gained nearly universal acceptance as a reliable and
sensitive method for detecting and possibly preventing neurologic injury during
surgical correction of spinal deformities. In several reports, spinal cord injury
was identified successfully based on changes in SSEP response characteristics,
specifically amplitude and latency. Less well documented and used, however, is
monitoring of peripheral nerve function with SSEPs to identify and prevent the
neurologic sequelae of prolonged prone positioning on a spinal frame. The authors
describe a patient who underwent surgical removal of spinal instrumentation but
was not monitored. A brachial plexopathy developed in this patient from pressure
on the axilla exerted by a Relton-Hall positioning frame during spinal surgery.
In addition, data are presented from 15 of 500 consecutive pediatric patients who
underwent surgical correction of scoliosis between 1993 and 1997 with whom
intermittent monitoring of ulnar nerve SSEPs was used successfully to identify
impending brachial plexopathy, a complication of prone positioning. A
statistically significant reduction in ulnar nerve SSEP amplitude was observed in
18 limbs of the 500 patients (3.6%) reviewed. Repositioning the arm(s) or
shoulders resulted in nearly immediate improvement of SSEP amplitude, and all
awoke without signs of brachial plexopathy. This complication can be avoided by
monitoring SSEPs to ulnar nerve stimulation for patients placed in the prone
position during spinal surgery.
PMID- 10780697
TI - Chromosome identification and assignment of DNA clones in the dog using a red fox
and dog comparative map.
AB - We have developed a novel method for identifying dog chromosomes and
unambiguously mapping specific clones onto canine chromosomes. This method uses a
previously established red fox/dog comparative chromosome map to guide the FISH
mapping of cloned canine DNA. Mixing metaphase preparations of the red fox and
dog enabled a single hybridization to be performed on both species. We used this
approach to map the chromosomal locations of twenty-six canine cosmids. Each
cosmid contains highly polymorphic microsatellite markers currently used by the
DogMap project to compile the canine linkage map. All but two cosmids were
successfully assigned to subchromosomal regions on red fox and dog chromosomes.
For eight cosmids previously mapped on dog chromosomes, we confirmed and refined
the canine chromosomal assignments of seven cosmids and corrected an erroneous
assignment regarding cosmid CanBern1. These results demonstrate that the red fox
and dog comparative chromosome map can greatly improve the accuracy and
efficiency of chromosomal assignments of canine genetic markers by FISH.
PMID- 10780698
TI - Maternally inherited X chromosome is not inactivated in mouse blastocysts due to
parental imprinting.
AB - Mouse embryos having an additional maternally inherited X chromosome (X(M))
invariably die before midgestation with the deficient extraembryonic ectoderm of
the polar trophectoderm lineage, whereas postnatal mice having an additional
paternally inherited X chromosome (X(P)) survive beyond parturition. A
cytogenetic study led us to hypothesize that abnormal development of such embryos
disomic for X(M) (DsX(M)) is attributable to two doses of active X(M) chromosome
in extraembryonic tissues. To test the validity of this hypothesis, we examined
the initial X chromosome inactivation pattern in embryos at the blastocyst stage
by means of replication banding method as well as RNA FISH detecting Xist
transcripts. X(P) was the only asynchronously replicating X chromosome, if any,
in X(M)X(M)X(P) blastocysts, and no such allocyclic X chromosome was ever
detected in X(M)X(M)Y blastocysts. In agreement with these findings, only one
Xist paint signal was detected in 79% of X(M)X(M)X(P) cells, whereas no such
signal was found in X(M)X(M)Y embryos. Thus, the present study supports the
hypothesis that two X chromosomes remaining active in the extraembryonic cell
lineages due to the maternal imprinting explain the underdevelopment of
extraembryonic structures and hence early postimplantation death of DsX(M)
embryos.
PMID- 10780699
TI - An XX/XY sex chromosome system in a fish species, Hoplias malabaricus, with a
polymorphic NOR-bearing X chromosome.
AB - Cytogenetic studies were carried out in the fish, Hoplias malabaricus, from the
Parque Florestal do Rio Doce (Brazil). This population is characterized by 2n =
42 chromosomes for both males and females and an XX/XY sex chromosome system,
confirmed through several banding methods. Females show 24 metacentric, 16
submetacentric and 2 subtelocentric chromosomes. Males show 24 metacentric, 17
submetacentric and 1 subtelocentric chromosomes. While the X chromosome is easily
recognized (the only subtelocentric element), the Y chromosome is somewhat
difficult to identify but appears to correspond to the smallest submetacentric in
the male karyotype. In-situ hybridization with an 18S rDNA probe showed 10 well
labeled chromosomes, including the X chromosome. The 5S rDNA is interstitially
located in a single metacentric pair independent of the 18S rDNA sites. The NOR
on the X chromosome is always active and occurs adjacent to a heterochromatic
distal segment on the long arm. Variations in size of the NORs and/or
heterochromatic segment correspond to a polymorphic size condition observed in
the X chromosome. The present results confirm the XX/XY sex chromosome system in
the population analyzed as well as a new cytotype in the Hoplias malabaricus
group.
PMID- 10780700
TI - Introgression of Lilium rubellum Baker chromosomes into L. longiflorum Thunb.: a
genome painting study of the F1 hybrid, BC1 and BC2 progenies.
AB - Interspecific hybrids between Lilium longiflorum (L, 2n = 2x = 24) and Lilium
rubellum (R, 2n = 2x = 24) were produced with the aim of transferring desirable
horticultural traits from L. rubellum to L. longiflorum. All F1 hybrids (LR, 2n =
2x = 24) and BC1 individuals (LLR, 2n = 3x = 36) were phenotypically uniform for
plant height, flowering time, leaf shape and flower colour. The BC1 plants were,
in spite of their triploid nature, fertile and could be used as a female parent
in backcrossings with autotetraploid L. longiflorum (LLLL, 2n = 4x = 48). Twelve
BC2 individuals were obtained and three of them were selected for further
chromosome analysis. As L. longiflorum and L. rubellum chromosomes were
indistinguishable in the hybrids, genomic in-situ hybridization (GISH) was
applied to establish the parentage of the chromosomes of the F1 hybrids and the
BC1 and BC2 progenies. GISH confirmed the LLRR constitution of the doubled
amphimonoploid (allodiploid), and the LLR constitution of all BC1 plants. The
three selected BC2 plants were, as expected, aneuploid, containing three complete
sets of L. longiflorum chromosomes and six, seven or eight L. rubellum
chromosomes, respectively. However, L/R translocation or recombinant chromosomes
could not be demonstrated in the mitotic metaphase complements of the F1, BC1 and
BC2 plants. In spite of the high frequencies of homoeologous recombination in the
F1 hybrids (LR) pollen was found to be sterile in all cases. At metaphase I of
the pollen mother cells of the BC1 plants, genome painting did not reveal any
cases of homoeologous pairing and recombination between L and R chromosomes. This
lack of exchange between homoeologous chromosome segments indicates complete
preferential pairing of the L and R chromosomes in the F1 (amphidiploid) and BC1
plants. It seems that the preferential pairing in the F1 and BC1 hybrids hinder
the introgression of the chromosome segments or species-specific genes into the
recipient for breeding purposes.
PMID- 10780701
TI - Evaluation of 24-color multifluor-fluorescence in-situ hybridization (M-FISH)
karyotyping by comparison with reverse chromosome painting of the human breast
cancer cell line T-47D.
AB - Multifluor-fluorescence in-situ hybridization (M-FISH) chromosome paints for all
the chromosomes in the human complement labeled with different combinations of
fluorochromes is a recent technological development enabling assignment of
chromosomal material to rearranged chromosomes. Little data is available on the
accuracy and limitations of the approach to the analysis of complex karyotypes,
which are characteristic of many malignant diseases. Here we compare M-FISH
analysis of the breast-cancer-derived cell line T-47D with a previous analysis by
reverse chromosome painting analysis of flow-sorted chromosomes from the same
material. This demonstrated a high degree of concordance. It also illustrated the
limitations of M-FISH analysis, including difficulties identifying small regions
of chromosomal material and intrachromosomal rearrangements. Confirmation of
selected aberrations using less-complex mixtures of painting probes and further
definition of abnormalities using single copy markers may be required. The
detailed karyotype description possible by M-FISH analysis contrasts with the
definition in the original G-banding analysis. This and the level of concordance
with reverse FISH painting supports the utility of the approach in the definition
of complex karyotypes.
PMID- 10780702
TI - Fate of multicentric and ring chromosomes induced by a new gametocidal factor
located on chromosome 4Mg of Aegilops geniculata.
AB - A new gametocidal (Gc) factor was identified on chromosome 4Mg of Aegilops
geniculata Roth. When transferred to Chinese Spring wheat, monosomic and disomic
Triticum aestivum-Ae. geniculata chromosome 4Mg addition plants undergo regular
first and second meiotic divisions. Male gametogenesis in disomic 4Mg addition
plants also is normal. However, chromosome breakage and anaphase bridges were
observed at ana/telophase of the first (29%) and second (11%) pollen mitosis in
monosomic 4Mg addition plants. Gc-induced multicentric and ring chromosomes can
be transmitted to the offspring and initiate breakage fusion bridge (BFB) cycles
in dividing root tip meristem cells of the derived sporophytes. The fate of
multicentric and ring chromosomes was analyzed in root meristems at different
time intervals after seed germination. The majority of the BFB cycles ceased
about 32 days after germination. Broken chromosome ends were healed either by the
fusion of a centric and an acentric fragment forming terminal translocation
chromosomes or as deficiencies or telocentric chromosomes. Lack of cytologically
detectable telomeric repeats at the stabilized newly broken termini suggests that
chromosome healing by addition of telomeric repeats may be a gradual process.
PMID- 10780703
TI - Replication asynchrony increases in women at risk for aneuploid offspring.
AB - We attempted to demonstrate a relation between a loss of replication control,
centromere dysfunction, and predisposition to non-disjunction. Couples with a
Down syndrome offspring were the high-risk probands. One-color FISH (fluorescent
in-situ hybridization) was applied to interphase nuclei (lymphocytes).
Replication pattern of two pairs of alleles, RB-1 and 21q22, were studied, and
the rate of aneuploidy was estimated using two alpha-satellite probes of
chromosomes 8 and 18. Our results suggest the existence of an association between
replication timing and the rate of non-disjunction. A higher rate of allele
asynchrony and aneuploidy was found in older women and in mothers of a Down
syndrome offspring. These findings may reflect a predisposition for meiotic non
disjunction in these women.
PMID- 10780704
TI - Evidence that kinetochore fibre microtubules shorten predominantly at the pole in
anaphase flea-beetle spermatocytes.
AB - Kinetochore spindle fibres in flea-beetle metaphase primary spermatocytes have
two regions with distinct morphologies. As seen after staining with antibodies
against tubulin, the kinetochore microtubules are tightly bundled in the 5 microm
closest to the kinetochore but they splay out in the region closest to the pole.
This morphology persists throughout anaphase. This distinct morphology allows one
to deduce the site where kinetochore microtubules depolymerise during anaphase.
During poleward movement of the autosomes in anaphase, the bundled region
shortens by about 0.25 microm for each 1 microm the chromosome moves poleward;
this suggests that, during anaphase, 75% of the kinetochore microtubule
shortening occurs at the pole end. Sex chromosomes in metaphase cells are
separated from the autosomes and do not move poleward at the same time as the
autosomes: they are reported to move poleward when the autosomes are in
metaphase, to stop part way to the poles, and to move poleward again as the
autosomes do (Virkki 1970). Kinetochore microtubules of the sex chromosomes also
have bundled and splayed regions; measurements of those regions suggest that
these chromosomes may move poleward before the autosomes enter anaphase, but not
afterwards.
PMID- 10780705
TI - The consequences of a non-uniform tension across kinetochores: lessons from
segregation of chromosomes in the permanent translocation heterozygote Oenothera.
AB - The alternate (zigzag) configuration of the chromosome ring in oenotheras
fulfills the requirement of high tension across kinetochores for stability of the
configuration and the progression to anaphase. However, also semialternate
configurations (two pairs of adjacent kinetochores interspaced among the zigzag)
fulfill the requirement of high tension across kinetochores. If only the
magnitude of tensile force acting on a kinetochore pair governs the stability of
microtubule attachments, the probability of occurrence of the semialternate
configurations would be higher than that of fully alternate configurations. Yet
the percentage of irregularity in the zigzag configuration is surprisingly low,
which means that the semialternate configurations are corrected. The only
difference which distinguishes the fully alternate and the semialternate
configurations with respect to the tension across kinetochores is that the
tension across a kinetochore alternating with its neighbors is rather uniformly
distributed over the kinetochore, while there is a gradient of the tension in the
kinetochore having a non-alternating neighbor, with low tension on the side of
this neighbor. Apparently, a low tension across a part of a kinetochore brings
about correction of its attachment to microtubules. This hypothesis fits with the
repeat subunit model of the kinetochore; apparently, each subunit can function
autonomously in the tension-governed mechanisms, stabilizing its attachment and
controlling the metaphase-to-anaphase transition.
PMID- 10780706
TI - Chromosomal mapping of adenosine receptor genes in chicken suggests clustering of
two members of the gene family.
PMID- 10780707
TI - Mariner-like transposable elements are interspersed within the rDNA-associated
heterochromatin of the pufferfish Tetraodon fluviatilis (Osteichthyes).
PMID- 10780708
TI - Association of antiretroviral therapy with detection of HIV-1 RNA and DNA in the
anorectal mucosa of homosexual men.
AB - OBJECTIVE: To determine whether combination antiretroviral therapy is associated
with reduced detection of HIV-1 RNA and DNA in the anorectal mucosa of men who
have sex with men (MSM). DESIGN: Cross-sectional study of 233 MSM recruited from
community and clinic sites in Seattle, Washington between July 1996 and December
1997. METHODS: HIV-1 RNA and HIV-1 DNA were detected in anorectal swab specimens
by polymerase chain reaction amplification assays. RESULTS: HIV-1 RNA was
detected significantly less often in anorectal specimens from users of
combination antiretroviral therapies, whether a protease inhibitor was received
(15/89; 17%) or not (16/53; 30%), than in men not receiving therapy (43/88; 49%)
(P < 0.001, P = 0.03, respectively). In contrast, HIV-1 DNA was detected only
slightly less frequently in anorectal specimens obtained from men receiving
protease inhibitors (35/81; 43%) or reverse transcriptase inhibitors alone
(22/48; 46%) than in specimens from men not receiving therapy (45/78; 58%) (P =
0.07, P = 0.20, respectively). Among men with < 50 copies HIV-1 RNA/ml plasma,
detection of HIV-1 RNA in anorectal specimens was rare (1/54; 2%) but detection
of HIV-1 DNA was common (14/50; 28%). CONCLUSIONS: Combination antiretroviral
therapy is associated with reductions in HIV-1 RNA, but HIV-1 DNA remains
detectable in the anorectal canal of almost half of MSM receiving such therapy.
Condom use during anal intercourse should be encouraged, regardless of plasma
viral load response to potent antiretroviral therapy.
PMID- 10780709
TI - HIV-1 Tat increases endothelial solute permeability through tyrosine kinase and
mitogen-activated protein kinase-dependent pathways.
AB - OBJECTIVE: HIV-1 infection is associated with alterations of several vascular
endothelial functions including adhesion molecule expression, growth, and
vascular permeability. The bases of these errors are not known, but might involve
secretion of the HIV-1 derived transcription factor 'Tat-1'. This study
investigated Tat-1 mediated endothelial barrier changes and second message
regulation of this phenomenon. METHODS: We exposed human umbilical vein
endothelial cell monolayers to Tat-1 (0-150 ng/ml) for up to 48 h and measured
resulting changes in monolayer permeability. We also investigated the role of
tyrosine and mitogen activated protein (MAP) kinases, and protein kinase G using
the pharmacological blockers genistein, PD98059 and KT5823 respectively. RESULTS:
Tat-1 significantly reduced monolayer barrier and increased albumin permeability
within 24 h. Tat-1 also stimulated tyrosine phosphorylation of multiple
endothelial proteins, disorganized junctional phosphotyrosine staining and
increased the number of these immunostaining structures. The increased
permeability produced by Tat-1 was blocked by genistein and PD98059, but not by
KT5823. Genistein and PD98059 pretreatment also prevented the changes in
phosphotyrosine immunostaining produced by Tat-1 and blocked phosphorylation of
several proteins including MAP kinase. CONCLUSION: These results suggest that HIV
may dysregulate endothelial barrier through the effects of Tat-1. These blocker
experiments suggest that the effects of Tat are transcription/translation
dependent. These data demonstrate that Tat increases endothelial albumin
permeability in vitro through tyrosine kinase and MAP kinase, but not protein
kinase G pathways.
PMID- 10780710
TI - Global distribution of the CCR2-64I/CCR5-59653T HIV-1 disease-protective
haplotype.
AB - OBJECTIVES: Several natural polymorphisms in the genes for the human CC-chemokine
receptors CCR5 and CCR2 are associated with HIV-1 disease. The CCR2-64I genetic
variant [a G to A substitution resulting in a valine (V) to isoleucine (I) change
at position 64] is in strong linkage disequilibrium with a mutation within the
CCR5 regulatory region (CCR5-59653T). Individuals with two CCR2-64I alleles are
not resistant to sexual transmission of HIV-1, but progress significantly more
slowly to HIV-1 disease. It is therefore important to determine the global
distributions of CCR2-64I and CCR5-59653T genetic variants and define the degree
of linkage between them. DESIGN AND METHODS: We have developed molecular beacon
based, real-time PCR allele discrimination assays for all three chemokine
receptor mutations, and used these spectral genotyping assays to genotype 3923
individuals from a globally distributed set of 53 populations. RESULTS: CCR2-64I
and CCR5-59653T genetic variants are found in almost all populations studied:
their allele frequencies are greatest (approximately 35%) in Africa and Asia but
decrease in Northern Europe. We confirm that CCR2-64I is in strong linkage
disequilibrium with CCR5-59653T (96.92% of individuals had the same genotype for
both CCR2-64I and CCR5-59653T polymorphisms). CONCLUSIONS: The greater
geographical distribution of the CCR2-64I/CCR5-59653T haplotype compared with
that of CCR5-delta32 suggests that it is a much older mutation whose origin
predates the dispersal of modern humans.
PMID- 10780711
TI - Factors associated with the successful modification of antiretroviral therapy.
HIV Outpatient Study Investigators.
AB - OBJECTIVES: To assess the characteristics of medication regimen modification and
the influence of a commercial genotypic resistance assay on the short-term (3-12
weeks) viral load response (> or = 0.5 log reduction) in HIV-1-infected patients
extensively treated with antiretroviral therapy (ART). METHODS: A nested cohort
study was performed in two clinics from the HIV Outpatient Study of 96 persons
with a HIV-1 viral load of 10(4) log copies/ml or greater taking at least two
antiretroviral medications. RESULTS: Successful modification was associated with
adding at least two new medications [relative risk (RR), 1.5; 95% confidence
interval (CI), 1.1-2.2], adding a drug from a previously unused class of agents
(RR, 2.0; CI, 1.4-2.9), the initiation of a non-nucleoside reverse transcriptase
inhibitor (NNRTI) (RR, 1.7; CI, 1.2-2.4), but not substituting a protease
inhibitor or the use of a commercial genotypic resistance assay. CONCLUSION:
Incorporating a drug from a previously unused class or changing at least two new
medications, but, within the confines of this study, not using a commercial
genotypic resistance assay, was associated with the successful modification of
ART as measured by a reduction in viral load.
PMID- 10780713
TI - Oral zidovudine during labor to prevent perinatal HIV transmission, Bangkok:
tolerance and zidovudine concentration in cord blood. Bangkok Collaborative
Perinatal HIV Transmission Study Group.
AB - OBJECTIVES: To evaluate tolerance for the oral administration of zidovudine (ZDV)
during labor and measure the resulting ZDV concentrations in umbilical cord
blood. DESIGN: A cross-sectional study of women in a placebo-controlled trial of
short-course ZDV (twice a day from 36 weeks' gestation until labor and every 3 h
during labor) to prevent perinatal HIV transmission in Bangkok. METHODS:
Umbilical cord blood was collected. Sixty control specimens and specimens from
372 women (182 in the ZDV group, 190 in the placebo group) were tested for ZDV by
radioimmunoassay (lower detection limit < 1 ng/ml). RESULTS: All women in the ZDV
group took one or more labor dose, 170 (93%) took their last dose within 3 h of
delivery, and only five (3%) experienced nausea or vomiting, a proportion similar
to the placebo group. The median concentration of ZDV in the cord blood in the
ZDV group was 252 ng/ml (range, < 1-1133 ng/ml); 31 (17%) specimens were less
than 130 ng/ml (0.5 microM), the concentration thought to be active against HIV
in vitro. Median concentrations were 189 ng/ml in specimens from women taking one
or two labor doses, 290 ng/ml in those taking three or four doses, and 293 ng/ml
in those taking more than four doses (P < 0.01). The ZDV concentration was not
associated with time since the last dose, body weight, or perinatal transmission.
CONCLUSION: Oral intrapartum ZDV was feasible and well tolerated. Most ZDV
concentrations in the cord blood after oral dosing during labor were at
therapeutic concentrations but were lower than those reported after continuous
intravenous administration. Although concentrations were not associated with
perinatal transmission, these data do not exclude the possibility that
intrapartum and neonatal chemoprophylaxis is effective.
PMID- 10780712
TI - Insights into the reasons for discontinuation of the first highly active
antiretroviral therapy (HAART) regimen in a cohort of antiretroviral naive
patients. I.CO.N.A. Study Group. Italian Cohort of Antiretroviral-Naive Patients.
AB - OBJECTIVE: To evaluate the frequency of discontinuation of the first highly
active antiretroviral regimen (HAART) and the factors predictive of discontinuing
for toxicity and failure in a population-based cohort of HIV-positive individuals
in Italy, naive from antiretrovirals at enrolment. METHODS: The study population
consisted of individuals who initiated HAART and had at least one follow-up
visit. The primary end-points were discontinuation of any component of HAART for
drug toxicity and discontinuation for failure. Survival analyses were performed
to identify predictive factors for reaching the two end-points. RESULTS: Eight
hundred and sixty-two individuals initiated HAART; in 727 of them (84.3%) this
consisted of two nucleoside reverse transcriptase inhibitors (NRTI) and one
protease inhibitor (PI). Over a median follow-up of 45 weeks, 312 patients
(36.2%) discontinued therapy: 182 (21.1%) discontinued due to toxicity, 44 (5.1%)
due to failure. The probability of discontinuing HAART at 1 year was 25.5% [95%
confidence interval (CI), 21.9-28.9] due to toxicity and 7.6% (95% CI, 4.9-1 0.3)
due to failure. Independent factors associated with discontinuation for toxicity
were: gender [relative hazard (RH) = 0.51; 95% CI, 0.32-0.80 for men versus
women], type of treatment (indinavir-containing regimens, RH = 1.94; 95% CI, 1.10
3.41 and ritonavir-containing regimens, RH = 3.83; 95% CI, 2.09-7.03 versus hard
gell saquinavir) and time spent on treatment (RH = 0.89; 95% CI, 0.80-0.98 for
each additional month). Discontinuation due to failure was independently
associated with the most recent HIV-RNA (RH = 3.20; 95% CI, 1.74-5.88 for log10
copies/ml higher), and with type of treatment (indinavir-containing regimens, RH
= 0.21; 95% CI, 0.06-0.78 and ritonavir-containing regimens, RH = 0.23; 95% CI,
0.04-1.26 versus hard-gell saquinavir). CONCLUSIONS: If the current HAART regimen
caused no toxicity, less than 10% of naive patients discontinue their first HAART
regimen because of failure after 1 year from starting therapy.
PMID- 10780714
TI - Induction and maintenance therapy of cytomegalovirus central nervous system
infection in HIV-infected patients.
AB - OBJECTIVE: To evaluate the efficacy and safety of the foscarnet-ganciclovir
combination in induction therapy (IT) and maintenance therapy (MT) for
cytomegalovirus (CMV) central neurological disorders in HIV-infected patients.
DESIGN: An open pilot non-comparative multicentre study. METHODS: Thirty-one
patients with acute CMV encephalitis (CMVe) (n = 17) or CMV myelitis (CMVm) (n =
14) during the era before highly active antiretroviral therapy (HAART) received
intravenous IT with foscarnet 90 mg/kg plus ganciclovir 5 mg/kg twice a day
followed by MT. The primary endpoint was clinical efficacy, assessed at the end
of the induction phase. RESULTS: The foscarnet-ganciclovir combination in IT
resulted in a 74% (23 out of 31 patients) clinical improvement or stabilization.
Eight patients did not respond clinically. Side-effects leading to drug
discontinuation occurred in 10 patients during IT. Among the 23 patients who
qualified for the maintenance phase, CMV disease progressed in 10, with a median
time to the first relapse of 126 days (range 64-264 days). Overall, the median
survival time was 3 months [95% confidence interval (CI), 2-4 months].
CONCLUSION: The combination of foscarnet and ganciclovir can safely be used for
CMV central nervous system (CNS) infection, with an improvement or stabilization
in 74% of patients. Life-long MT with this combination is recommended as long as
the immune system is profoundly impaired.
PMID- 10780715
TI - Predictors of tuberculosis transmission in prisons: an analysis using
conventional and molecular methods.
AB - OBJECTIVE: To determine the tuberculosis (TB) transmission patterns within the
prison system in Catalonia, conventional epidemiological techniques were combined
with DNA fingerprinting of Mycobacterium tuberculosis. METHODS: IS6110- and
polymorphic GC-rich repeat sequence (PGRS)-based restriction fragment length
polymorphism (RFLP) were combined with epidemiological studies to assess the
relatedness of isolates from all patients with confirmed TB at five prisons in
the province of Barcelona (Catalonia, Spain), between 1 July 1994 and 31 December
1996. Risk factors for transmission were analysed to a logistic regression. The
extent of drug-resistant TB was also assessed. RESULTS: The incidence of TB
during the study period was 2775 cases per 100,000 inmate years. Of the 247
culture-positive cases, 126 (51%) appeared to have active TB as a result of
recent transmission. Using conventional epidemiological methods, 14 active chains
of transmission were identified in prison involving 65 isolates (52% of clustered
patients). A lengthy history of imprisonment [odds ratio (OR) 2.8, 95% confidence
interval (CI) 1.52-5.11] and pulmonary TB (OR 2.36, 95% CI 1.17-4.75) were
independently associated with clustering. Low rates of both initial (2.9%) and
acquired drug resistance (5.8%) were identified and there was no evidence of the
transmission of drug-resistant TB. CONCLUSION: In the prison system studied, the
recent transmission of TB contributes substantially to the overall incidence of
the disease. Both lengthy incarcerations and delays in identifying inmates with
pulmonary symptoms play a key role in this recent transmission. Directly observed
therapy (DOT) is a critical control strategy for reducing the emergence of drug
resistance and for avoiding the transmission of resistant organisms.
PMID- 10780716
TI - Partner type and condom use.
AB - OBJECTIVES: To examine the association between type of sexual partnership and
condom use consistency. DESIGN: A prospective follow-up study of women attending
two urban clinics for sexually transmitted diseases (STD). METHODS: Sexual
diaries recording barrier method, partner initials and partner type for each act
of intercourse were kept by 869 women. Condom use by partner type was evaluated
in three ways in the entire group: among women who encountered multiple partners,
during months in which women encountered multiple partners, and within sexual
partnerships that changed status during the study. RESULTS: Consistency of condom
use was higher with new and casual partners than with regular partners in the
entire group and among women who encountered multiple partners. In months in
which partners of different types were encountered, condom-use consistency was
higher with new and casual partners than with regular partners. Consistent condom
use decreased in partnerships that changed status from new to regular. The female
condom was used more often with regular partners than with new or casual partners
in the entire study group, among women who encountered multiple partners, and
during months in which a woman achieved consistent use with her regular partner.
CONCLUSIONS: This study provides strong evidence that condom use behavior is
modified by partner type. Observations about condom use and partner type made in
cross-sectional or retrospective surveys also hold in the present longitudinal
analyses of individual women and of partnerships that change status. The female
condom may be an important option for achieving consistent protection within
stable partnerships.
PMID- 10780717
TI - Repeat HIV testing: high-risk behaviour or risk reduction strategy?
AB - OBJECTIVE: To examine the characteristics of repeat and first-time HIV testers
and consider their implications for HIV test counselling. METHODS: An anonymous
questionnaire was completed by nearly 1500 people seeking an HIV test between
September 1997 and July 1998 at a same-day HIV testing clinic in London, United
Kingdom. Repeat testers were those people who had previously tested HIV negative
and were returning for another test. Information was collected on self-reported
unprotected penetrative sex (UPS) in the previous 3 months and reasons for
seeking the present test. RESULTS: Overall, 50.6% (721/1446) of all clinic
attenders were repeat testers: gay men 71.7% (337/470), heterosexual men 42.1%
(208/494) and heterosexual women 38.6% (186/482). No significant differences were
found between repeat and first time testers in the frequency of UPS (P > or =
0.06). However, gay men (but not heterosexual men and women) reporting three or
more previous HIV tests were significantly more likely to report higher-risk UPS
(i.e. with a partner whose HIV status was either positive or unknown) (42.2%)
than those who had had one-two or no previous tests (25.3 and 25.4%,
respectively; P = 0.002). Over half the heterosexual men and women, and one third
of gay men said they were seeking the current HIV test in preparation for a new
relationship; these proportions did not differ significantly between repeat and
first-time testers (P > 0.1). CONCLUSION: In this London HIV testing clinic, no
significant differences were found in the frequency of UPS between repeat and
first-time testers with the exception of gay men with a history of three or more
previous HIV tests, who reported elevated levels of high-risk sexual behaviour.
For many people, repeat HIV testing has become part of a risk reduction strategy
to establish seroconcordance with a regular partner. HIV test counselling
provides the opportunity both to address high-risk behaviour and to reinforce
personal risk-reduction strategies.
PMID- 10780718
TI - Cancer risk among men with, or at risk of, HIV infection in southern Europe.
AB - OBJECTIVE: To evaluate the cancer risk in southern European men with, or at risk
of, HIV infection. DESIGN: An analysis of longitudinal data to assess time
dependent rare events. METHODS: Data from a cohort of HIV seroconverters, and
from two hospital-based HIV seroprevalent cohorts were combined and analysed. The
number of cancer cases observed was compared with the expected number, obtained
from cancer incidence rates among men in the general population. Age-standardized
incidence ratios (SIR) and their 95% confidence intervals (CI) were computed.
RESULTS: A total of 19,609 person-years of observation were accumulated among HIV
positive men, and 7957 person-years among HIV-negative men. Among HIV-positive
men, statistically significant increased SIR were seen for Hodgkin's disease (HD)
(SIR = 8.7), liver cancer (SIR = 11.0), and cancer of the salivary glands (SIR =
33.6). An excess of lung cancer was seen among intravenous drug users (IDU), but
not among homosexual men. When the risk of all non-AIDS-defining cancers was
considered, HIV-positive men had a nearly twofold excess (95% CI: 1.2-2.8). A
risk of similar magnitude emerged among HIV-negative IDU (95% CI: 1.0-4.5),
largely attributable to lung cancer and HD. CONCLUSION: These findings confirm
that HIV infection increases the risk of HD, whereas they suggest that the risk
of hepatocellular carcinoma may also be enhanced by HIV infection. The
observation of an elevated risk of lung cancer in both HIV-positive and HIV
negative IDU points to personal behaviours unrelated to HIV infection.
PMID- 10780719
TI - Ten-year trends in CD4 cell counts at HIV and AIDS diagnosis in a London HIV
clinic.
AB - OBJECTIVE: To examine temporal trends (1986-1996) in the CD4 cell count at first
HIV-1 positive test and initial AIDS diagnosis, and the influence of selected
patient characteristics and treatment factors on these trends. DESIGN: A
retrospective clinic-based study. SETTING: Three hospital-based clinics in West
London. PATIENTS: A group of 5921 adult HIV-1-seropositive persons and 2835
reported patients with AIDS over a 10-year period from 1 January 1986 to 1
October 1996. METHODS: The CD4 cell count at HIV diagnosis (CD4HIV) was defined
as the nearest CD4 cell count to within 2 months of HIV diagnosis; and the CD4
cell count at AIDS diagnosis (CD4AIDS) as the last CD4 cell count in the two
months prior to the development of AIDS. Simple and multiple linear regression
analysis were used to examine the influence of selected covariates on CD4HIV and
CD4AIDS. RESULTS: The percentage of patients with an available CD4HIV and CD4AIDS
increased from less than 5% in 1987 to 53% and 40%, respectively, in 1990, and
79% and 48%, respectively, in 1996. Patients with a missing CD4HIV or CD4AIDS
were younger and less likely to have received antiretroviral therapy or
prophylaxis for Pneumocystis carinii pneumonia (PCP). There was no significant
change in CD4HIV over a 10-year period (median 334 x 10(6) cells/l), but a lower
CD4HIV was associated with older age at presentation and injecting drug use.
There was a delay in the onset of clinical AIDS, with a fall in the median
CD4AIDS value from 99 x 10(6) cells/l prior to 1987, to 58 x 10(6) cells/l in
1990, 68 x 10(6) cells/l in 1994 and 60 x 10(6) cells/l in 1996; this decline in
onset was seen for PCP as well as for cytomegalovirus and atypical mycobacterial
infections. At all time periods, a lower CD4AIDS was associated with combined use
of antiretroviral therapy and PCP prophylaxis. After adjustment for use of
antiretroviral therapy and PCP prophylaxis prior to AIDS diagnosis, year of
diagnosis was no longer associated with CD4AIDS. There was a significant trend
towards an improved survival following AIDS diagnosis from 20.1 months prior to
1988, to 20.3 months (1989-1990), 21.0 months (1991-1992) and 22.1 (1993-1994) (P
< 0.0005). CONCLUSIONS: The observed decline in CD4AIDS value was related to the
introduction of antiretroviral therapy in 1988, and PCP prophylaxis in 1989.
Temporal changes in the CD4 cell count at HIV and AIDS diagnosis among different
demographic groups can provide insights into the changing natural history of the
HIV epidemic and access to medical care. We recommend monitoring of the CD4 cell
count at new HIV and AIDS diagnosis and at initiation of antiretroviral therapy
as additional measures in national HIV/AIDS surveillance.
PMID- 10780720
TI - Model-based evaluation of single-round mass treatment of sexually transmitted
diseases for HIV control in a rural African population.
AB - OBJECTIVES: To compare the impact of single-round mass treatment of sexually
transmitted diseases (STD), sustained syndromic treatment and their combination
on the incidence of HIV in rural Africa. METHODS: We studied the effects of STD
interventions by stochastic simulation using the model STDSIM. Parameters were
fitted using data from a trial of improved STD treatment services in Mwanza,
Tanzania. Effectiveness was assessed by comparing the prevalences of gonorrhoea,
chlamydia, syphilis and chancroid, and the incidence of HIV, in the general adult
population in simulations with and without intervention. RESULTS: Single-round
mass treatment was projected to achieve an immediate, substantial reduction in
STD prevalences, which would return to baseline levels over 5-10 years. The
effect on syphilis was somewhat larger if participants cured of latent syphilis
were not immediately susceptible to re-infection. At 80% coverage, the model
projected a reduction in cumulative HIV incidence over 2 years of 36%. A similar
impact was achieved if treatment of syphilis was excluded from the intervention
or confined to those in the infectious stages. In comparison with sustained
syndromic treatment, single-round mass treatment had a greater short-term impact
on HIV (36 versus 30% over 2 years), but a smaller long-term impact (24 versus
62% over 10 years). Mass treatment combined with improved treatment services led
to a rapid and sustained fall in HIV incidence (57% over 2 years; 70% over 10
years). CONCLUSIONS: In populations in which STD control can reduce HIV
incidence, mass treatment may, in the short run, have an impact comparable to
sustained syndromic treatment. Mass treatment combined with sustained syndromic
treatment may be particularly effective.
PMID- 10780721
TI - Sexually transmitted infections in European HIV-infected women: incidence in
relation to time from infection. European Study on the Natural History of HIV
Infection in Women.
AB - OBJECTIVES: To investigate the prevalence and incidence of sexually transmitted
infections (STI) in HIV-infected women in relation to time from infection and
sexual behaviour. DESIGN: The European study on the natural history of HIV
infection in women is a prospective cohort study of 487 HIV-infected women with a
known interval of seroconversion from 12 European countries. METHODS: Incidence
was measured with person-time methods. Generalized estimating equations analysis
was used to determine risk factors for STI. RESULTS: At entry, 15% of the women
were diagnosed with at least one acute STI (chlamydial infection, trichomoniasis
or gonorrhoea), 10% with at least one other STI (genital warts or genital
ulcerations) and 13% with vaginal candidiasis. Although frequently diagnosed
during follow-up, the occurrence of acute STI and vaginal candidiasis decreased,
whereas the occurrence of other STI increased with ongoing time from HIV
infection. Furthermore, women with a history of prostitution [relative risk (RR),
2.00; 95% confidence interval (95% CI), 1.20-3.33] and women with irregular
condom use (RR, 7.74; 95% CI, 3.52-17.0) were at higher risk for an acute STI.
CONCLUSIONS: Although STI diagnoses were frequent, the occurrence of acute STI
declined with time from infection which might be explained by changed sexual
behaviour over time. The occurrence of other STI increased with time from HIV
infection, presumably due to reactivation as a result of immunosuppression.
PMID- 10780722
TI - The effect of syringe exchange use on high-risk injection drug users: a cohort
study.
AB - OBJECTIVE: To determine whether syringe exchange program use is associated with
cessation of syringe sharing among high-risk injection drug users. DESIGN AND
METHODS: Between 1992 and 1996, street-recruited injection drug users were
interviewed and received HIV testing and counseling semi-annually, as part of a
dynamic cohort study. We examined a cohort of 340 high-risk injection drug users
for whom two observations, 6-months apart, were available and who reported
syringe sharing at the first interview. Multivariate logistic regression analysis
was performed to determine the relationship between syringe exchange program use
and cessation of syringe sharing, while controlling for confounding factors.
RESULTS: At follow-up interview, 60% (204 of 340) reported quitting syringe
sharing. High-risk injection drug users who began using the syringe exchange
program were more likely to quit sharing syringes [adjusted odds ratio (AOR),
2.68; 95% confidence interval (CI), 1.35-5.33], as were those who continued using
the syringe exchange program (AOR,1.98; 95% CI, 1.05-3.75) in comparison with non
syringe exchange program users, while controlling for confounding factors.
CONCLUSIONS: The initiation and continuation of syringe exchange program use
among high-risk injection drug users is independently associated with cessation
of syringe sharing. Syringe exchange program use can be an important component in
reducing the spread of blood-borne infectious diseases among high-risk injection
drug users.
PMID- 10780723
TI - Opposite effects of IFN-gamma on CCR5 and CXCR4 expression and on entry of M- and
T-tropic HIV in epithelial cells.
PMID- 10780724
TI - Increased incidence of peripheral neuropathy with co-administration of stavudine
and isoniazid in HIV-infected individuals.
PMID- 10780725
TI - The costs of antiretroviral drug wastage.
PMID- 10780726
TI - Immune recovery inflammatory folliculitis.
PMID- 10780727
TI - Pharmacokinetics of efavirenz in a patient on maintenance haemodialysis.
PMID- 10780728
TI - Effects of hydroxyurea on T cell count changes during primary HIV infection.
PMID- 10780729
TI - Cidofovir ocular toxicity is related to previous ocular history.
PMID- 10780730
TI - Detection of maternal DNA in cord blood at birth after elective caesarean section
or vaginal delivery.
PMID- 10780731
TI - HIV/sexually transmitted disease education and prevention in US bathhouse and sex
club environments.
PMID- 10780732
TI - Phenotypic resistance to protease inhibitors in patients who fail on highly
active antiretroviral therapy predicts the outcome at 48 weeks of a five-drug
combination including ritonavir, saquinavir and efavirenz.
PMID- 10780734
TI - Life-cycle of Isospora mehlhornii sp. nov. (Apicomplexa : Eimeriidae), parasite
of the Egyptian swallow Hirundo rubicola savignii.
AB - Fifty-seven Hirundo rubicola savignii swallows were collected from Damietta,
Tanta, Dakahlyia and Sharkia Provinces, Egypt. They were examined for coccidian
parasites. The percentage of infection with Isospora stages was 12.3%. After
diagnosis it was noted that the parasites belong to a new species. The
unsporulated oocysts were spherical, measuring 25.7-31.9 microm in diameter with
a mean of 28.3 microm. A micropyle, polar granule and oocyst residuum were
absent. Sporocysts appeared lemon-shaped and measured 19.6-24.5 microm x 12.5
17.5 microm with a mean of 22.9 x 14.4 microm. Stieda body and the sporocyst's
residual body were clearly visible. Sporozoites measured 11-14.2 x 4.4-5.1 microm
with a mean of 11.4 x 4.7 microm. Sporulation time was 72 h at room temperature
(25 degrees C). Endogenous stages including schizogony and gamogony were detected
in epithelial cells of the duodenum, jejunum and ileum of the host. Schizogony
consisted of two generations. Mature first generation schizonts reached up to 11
microm in diameter and produced merozoites measuring 3.5 x 1.7 microm. Mature
second generation schizonts measured 17.2 x 12.3 microm and produced merozoites
measuring 11.8 x 2.2 microm. Gamogonic stages were differentiated into
microgamonts and macrogamonts. Mature microgamonts were spherical and measured
23.2 microm in diameter, producing curved microgametes measuring 4.5 x 0.7
microm. The ovoid macrogametes measured 19.6 x 14.7 microm and were characterized
by a large nucleus and nucleolus. Early, more or less spherical, oocysts were
detected inside the intestinal epithelial cells and in the intestinal lumen. They
measured 19.6 microm in diameter. The sporont measured 17.2 microm in diameter.
Cytochemical studies on schizogony, gamogony and oocysts were accomplished and
showed distribution of polysaccharides and composition of the oocyst wall.
PMID- 10780733
TI - Expression of SAG-1 of Toxoplasma gondii in transgenic mice.
AB - We describe the expression of SAG-1 cDNA in B6C3F1 mice by microinjecting a 3.3
kbp DNA fragment, consisting of the cytomegalovirus enhancer-chicken beta-actin
hybrid promoter and SAG-1 into the pronucleus of a fertilized egg at the one-cell
stage. Offspring derived from this microinjection were analyzed for the
integration and functional expression of the SAG-1 transgene. Steady-state
expressions of both the mRNA for SAG-1 and SAG-1 protein product were detected in
the brain, thymus, spleen and liver. Approximately 50% of F1 and F2 progeny
inherited the SAG-1 transgene from SAG-1 transgenic mice in Mendelian fashion.
These results indicated that SAG-1 transgenic lines were established. Transgenic
mice harboring the SAG-1 gene will contribute a critical tool of defining the
molecular mechanisms of SAG-1 in pathogenesis and host immune response.
PMID- 10780735
TI - A cDNA encoding the highly immunodominant antigen of Strongyloides stercoralis:
gamma-subunit of isocitrate dehydrogenase (NAD+).
AB - A full length cDNA encoding the highly immunodominant 41 kDa antigen of
Strongyloides stercoralis (P5), recognized by 83% of human patients [Siddiqui et
al. (1997) Parasitol Res 83:655-658], is obtained. A clone containing a 1371 bp
insert was selected following screening of the S. stercoralis cDNA library with
antibodies specific to antigen P5. The nucleotide sequence of this insert
identified a cDNA coding for the gamma-subunit of isocitrate dehydrogenase
(NAD+), GenBank Accession Number AF176568. The conceptually translated amino acid
sequence of the open reading frame for the gamma-subunit of S. stercoralis
isocitrate dehydrogenase (NAD+) encodes a 388 amino acid residue protein with an
apparent molecular weight of 43 kDa and a predicted pI of 7.15. The sequence is
71% A/T, reflecting the characteristic A/T codon bias of S. stercoralis. The
amino acid sequence of the S. stercoralis gamma-subunit of isocitrate
dehydrogenase (NAD+) is compared with those of Caenorhabditis elegans, rat and
human NAD(+)-ICDH. The diagnostic potential of the S. stercoralis gamma-subunit
of isocitrate dehydrogenase (NAD+) is also discussed.
PMID- 10780736
TI - Survival of destrobilated adults of Taenia crassiceps in T-cell-depleted
Mongolian gerbils.
AB - In Mongolian gerbils (Meriones unguiculatus), prednisolone treatment induces the
survival of strobilated Taenia crassiceps to sexual maturity followed by fecal
release of gravid proglottides. The mechanism underlying the effects of
prednisolone has not been elucidated in this taeniid/rodent model. Using a novel
murine monoclonal antibody specific to a cell-surface determinant of gerbil T
cells (HUSM-M.g.15 of IgG2b isotype) for in vivo depletion of the cells, we
examined the T-cell dependence of the following two phenomena: (1) elimination of
strobilated T. crassiceps from the intestine of naive gerbils, and (2) depressed
egg formation by the cestode in prednisolone-treated gerbils. In T-cell-depleted
gerbils, only destrobilated adults were recovered from the intestine, although
the recovery rate was comparable with that observed in prednisolone-treated
animals. Egg formation by the cestode in T-cell-depleted, prednisone-treated
gerbils did not differ from that seen in gerbils treated with prednisolone alone.
We conclude that one of main effects of prednisolone can be ascribed to the
suppression of T-cell functions that work to eliminate strobilated T. crassiceps
from gerbils.
PMID- 10780737
TI - Pseudocapillaria (Ichthyocapillaria) ophisterni sp. n. (Nematoda : Capillariidae)
from the swamp-eel Ophisternon aenigmaticum (Pisces) in Mexico.
AB - A new nematode species, Pseudocapillaria ophisterni sp. n., is described from the
intestine and rarely from the stomach of the swamp-eel, Ophisternon aenigmaticum
Rosen et Greenwood, from Catemaco Lake, Veracruz, Mexico. In having both caudal
lobes in the male interconnected by a distinct dorsal membrane, it belongs to the
subgenus Ichthyocapillaria. It differs from the three species in this subgenus
mainly in possessing either a distinctly longer spicule or a smaller length of
oesophagus relative to body length. It also differs in host type and geographical
distribution. P. ophisterni is the first capillariid species reported from
synbranchiform fishes.
PMID- 10780738
TI - Intracellular calcium and pH conditions of cultured cells infected with Eimeria
bovis or E. separata.
AB - Loading of Eimeria bovis-infected Vero cells with membrane-permeant acetoxymethyl
esters (AM-esters) of ion-sensitive dyes provided us with a noninvasive method
for investigation of the permeability of the parasitophorous vacuole membrane
(PVM) and simultaneous measurement of Ca2+ and H+ concentrations in different
compartments of the infected cells. The distribution patterns of the cleaved
membrane-impermeant dyes argue against the existence of nonselective pores in the
PVM. There is also no indication of a parasitophorous duct connecting the
vacuolar space with extracellular media. The pH inside the parasitophorous
vacuole (PV) was lower than that in the cytoplasm of the host cell or the
parasite, whereas the [Ca2+] in these compartments did not differ significantly.
In HT29 cells infected with E. separata for 24 h the Ca2+ response to
extracellular adenosine triphosphate (ATP) was significantly reduced, indicating
influences on the host cell's intracellular signaling.
PMID- 10780739
TI - Ultrastructure of spermiogenesis and the spermatozoon of Opecoeloides furcatus
(Trematoda, Digenea, Opecoelidae), a parasite of Mullus barbatus (Pisces,
Teleostei).
AB - Spermiogenesis and mature spermatozoa of Opecoeloides furcatus (Digenea,
Opecoelidae) are described by means of transmission electron microscopy.
Spermiogenesis in this fluke matches the general pattern of digenetic trematodes.
Striated rootlets associated with the two centrioles and an intercentriolar body
are present in the differentiation zone. Flagellar rotation of two flagella and
their proximodistal fusion with a median cytoplasmic process also characterize
the spermiogenesis of O. furcatus. Nevertheless, asynchronicity is reported for
the proximodistal fusion of the two flagella. Mature spermatozoa of O. furcatus
are filiform, tapering at both ends and they present all the characteristic
features found in the Digenea gamete: two flagella, mitochondrion, nucleus and
two bundles of parallel cortical microtubules. Nevertheless several peculiarities
distinguish the mature spermatozoon of O. furcatus from the gamete of other
digenetic trematodes.
PMID- 10780740
TI - In vitro leucocyte proliferative responses and lymphocyte sub-types in guinea
pigs with genetically determined high- and low-level responsiveness to
Trichostrongylus colubriformis.
AB - In vitro leucocyte proliferative responses to parasite antigens and to mitogens
as well as lymphocyte sub-types were compared in guinea pigs with genetically
determined differences in their ability to express protective immunity against
Trichostronylus colubriformis infection. Proliferative responses to parasite
antigens were greatest in high-responder (HR) animals, but cells from low
responder (LR) animals were generally more responsive to mitogens. However, HR
circulating leucocytes were more responsive to the T-cell-dependent B-cell
mitogen pokeweed mitogen (PWM), and the response of HR, but not LR, cells
increased during primary infection with T. colubriformis. Flow cytometry revealed
significantly greater numbers of circulating B-cells in HR animals and, as
observed for responsiveness to PWM, the number of circulating B-cells increased
in HR, but not LR, animals during primary infection with this parasite. These
findings suggest a larger and more labile population of B-cells in HR guinea
pigs.
PMID- 10780741
TI - Further report on Cryptosporidium in Barcelona zoo mammals.
AB - The prevalence of fecal shedding of Cryptosporidium in 36 primates (21 species
and subspecies) and 62 herbivores (36 species and subspecies) housed at the
Barcelona zoo was studied. Cryptosporidial oocysts were found in stool samples of
14 Primate, 18 Artiodactyla, 2 Perissodactyla, and 1 Proboscidea species. None of
them showed symptoms related to the parasite. Neither the sex nor the group
condition (alone or in a group) of the animals studied appeared to be correlated
with parasitic prevalence. The results extend the host species range of the
protozoan to 18 new animals (6 Primate, 10 Artiodactyla, 1 Perissodactyla, and 1
Proboscidea species) and confirm the endemic status of Cryptosporidium at the
Barcelona zoo. We conclude that maintenance of the parasitic endemic status is
probably due to the presence of animal carriers as well as to the physical
features of some facilities where oocysts could remain viable and infectious.
PMID- 10780743
TI - Scanning electron microscopy of Chilomastix mesnili (Wenyon 1910) Alexieieff,
1912.
AB - Scanning electron microscopy of Chilomastix mesnili shows that the cysts are
lemon-shaped with one end broadly rounded and the other conical. The trophozoite
has five flagella coming out of the anterior end. Four of these are free and the
fifth is attached to the body by an undulating membrane. The undulating membrane
extends along the whole length of the body of the parasite with the exception of
the tail. The tail is an elongated structure almost equal in length to the main
body of the parasite.
PMID- 10780742
TI - Development of Fasciolopsis buski (Trematoda : Fasciolidae) in Hippeutis
umbilicalis and Segmentina trochoideus (Gastropoda : Pulmonata).
AB - Sequential development and histopathologic effects of Fasciolopsis buski larvae
were examined in two species of pulmonate snail, Hippeutis umbilicalis and
Segmentina trochoideus. Miracidial attachment and penetration began 5 min post
exposure (PE). On day 2 PE, the sporocysts rapidly increased in size and over
days 3-7 PE, they transformed into mother rediae which migrated to the ovotestis
on day 10 PE. In both species of snail, daughter rediae were initially observed
on day 17 PE, the first cercariae emerged on day 21 PE, and from that day onward
daughter rediae were the dominant larval form occupying the ovotestis.
Histopathologic changes were confined exclusively to the ovotestis and included
lytic lesions due to mechanical damage, and disappearance of all cellular
elements. No inflammatory responses were observed in the ovotestis, and no
degenerated larvae of any kind were observed in the snails. Infected snails did
not produce egg masses and lived no longer than 35 days. The lack of differences
in miracidial recognition and penetration, and in the temporal, sequential, and
spatial development of F. buski larvae in H. umbilicalis and S. trochoideus
indicate that both these snail species are equally susceptible to F. buski.
PMID- 10780744
TI - Cloning and characterization of Entamoeba histolytica antigens recognized by
human secretory IgA antibodies.
AB - To identify the Entamoeba histolytica antigens capable of inducing secretory IgA
(sIgA) responses in humans, a cDNA library from the strain HM1:IMSS was immuno
screened with saliva from patients with intestinal amebiasis or amebic liver
abscess. Clones isolated with sIgA antibodies from patients with intestinal
amebiasis corresponded to the known serine-rich protein isoform, a 29 kDa
cysteine-rich protein and 1-alpha elongation factor. Clones corresponding to
enolase, cyclophilin, ribosomal protein L23a, and an Hsp70 family protein were
isolated with sIgA from a patient with amebic liver abscess. A glutamic acid-rich
peptide (EhGARP) positive with sIgA from a patient with amebic liver abscess was
also isolated; for EhGARP, no homologs were found in the protein databases. The
antigens isolated are potentially useful in the development of an oral vaccine or
new diagnostic tools for amebiasis.
PMID- 10780745
TI - Presence of Phlebotomus (Transphlebotomus) mascittii Grassi, 1908 (Diptera :
Psychodidae) in Germany.
AB - During an entomology survey in July 1999, one male and three female Phlebotomus
(Transphlebotomus) mascittii were caught in southwestern Baden Wurttemberg. This
is the first record of phlebotomine sandflies in Germany.
PMID- 10780746
TI - Prevalence of Haplometra cylindracea infection in three species of Lymnaea snails
in central France.
AB - Field investigations were performed over a 2- or 3-year period at five sites in
central France to determine the prevalence of Haplometra cylindracea infection in
three species of adult Lymnaea, and to compare it with that of Fasciola hepatica
infection recorded in the same snails. L. glabra, L. palustris, and L. truncatula
harboured Haplometra larval forms but the prevalence of this infection varied
according to the site and snail species studied. The prevalences in May ranged
over 0-66.9% in L. glabra, 3-7.7% in L. palustris, and 0-31.5% in L. truncatula.
The mean intensity of H. cylindracea infection in May did not show any
significant variation, whatever the site and species studied. The prevalence of
F. hepatica infection was significantly lower in snails collected in sites known
for H. cylindracea infection than in those originating from nearby meadows (0-1%
instead of 1-5%). H. cylindracea could develop in some Lymnaea species and its
occurrence had an impact in snails by decreasing the prevalence of F. hepatica
infection.
PMID- 10780747
TI - Helminth fauna of snakes (Reptilia, Serpentes) in Belorussian Polesye.
PMID- 10780748
TI - Findings of Fasciola hepatica Linnaeus 1758, in wild animals in Belorussian
Polesye.
PMID- 10780749
TI - Helminth fauna of lizards (Reptilia, Sauria) in the southern part of Belarus.
PMID- 10780750
TI - Postpneumonectomy pulmonary oedema revisited.
PMID- 10780751
TI - Do long-acting beta2-adrenergic agonists deserve a different place in guidelines
for the treatment of asthma and COPD?
PMID- 10780752
TI - Development of severe hypoxaemia in chronic obstructive pulmonary disease
patients at 2,438 m (8,000 ft) altitude.
AB - The arterial oxygen tensions (Pa,02) in chronic obstructive pulmonary disease
(COPD) patients travelling by air, should, according to two different guidelines,
not be lower than 7.3 kPa (55 mmHg) and 6.7 kPa (50 mmHg), respectively, at a
cabin pressure altitude of 2,438 m (8,000 ft). These minimum in-flight Pa,O2
values are claimed to correspond to a minimum Pa,O2 of 9.3 kPa (70 mmHg) at sea
level. The authors have tested whether this limit is a safe criterion for
predicting severe in-flight hypoxaemia. The authors measured arterial blood gases
at sea-level, at 2,438 m and at 3,048 m (10,000 ft) in an altitude chamber at
rest and during light exercise in 15 COPD patients with forced expiratory volume
in one second (FEV1) <50% of predicted, and with sea-level Pa,O2 >9.3 kPa.
Resting Pa,O2 decreased below 7.3 kPa and 6.7 kPa in 53% and 33% of the patients,
respectively, at 2,438 m, and in 86% and 66% of the patients at 3,048 m. During
light exercise, Pa,O2 dropped below 6.7 kPa in 86% of the patients at 2,438 m,
and in 100% of the patients at 3,048 m. There was no correlation between Pa,O2 at
2,438 m and pre-flight values of Pa,O2, FEV1 or transfer factor of the lung for
carbon monoxide. In contrast to current medical guidelines, it has been found
that resting arterial oxygen tension >9.3 kPa at sea-level does not exclude
development of severe hypoxaemia in chronic obstructive pulmonary disease
patients travelling by air. Light exercise, equivalent to slow walking along the
aisle, may provoke a pronounced aggravation of the hypoxaemia.
PMID- 10780753
TI - Endothelin mediates pulmonary vascular remodelling in a canine model of chronic
embolic pulmonary hypertension.
AB - It is well known that endothelin (ET)-1 mediates vascular remodelling in various
kinds of clinical and experimental pulmonary hypertension. The aim of this study
was to investigate whether ET-1 is associated with the development of pulmonary
vascular remodelling in a canine model of chronic embolic pulmonary hypertension.
Pulmonary hypertension was induced in 10 mongrel dogs by repeated embolization
with ceramic beads. In five of the dogs, bosentan, a nonselective ET receptor
antagonist, was administered throughout the study. Haemodynamic measurements and
plasma ET-1 assays were performed every 2 months. Eight months after initial
embolization, computer-assisted morphometry and immunohistochemistry were
performed on the lung tissue including that from three control dogs. Pulmonary
arterial pressure and pulmonary vascular resistance were increased in all
embolized dogs, compared to baseline. In nontreated embolized dogs, plasma ET-1
concentration and pulmonary arterial wall thickness were increased compared to
control animals, and ET-1 immunoreactivity was detected in thickened pulmonary
arteries. In bosentan treated dogs, pulmonary arterial walls were not
significantly thickened. Pulmonary vascular remodelling, associated with elevated
plasma endothelin-1 levels and positive endothelin-1 immunoreactivity in lung
tissue is attenuated by the endothelin receptor antagonist, bosentan. These
findings suggest that endothelin mediates pulmonary vascular remodelling in a
canine model of chronic embolic pulmonary hypertension.
PMID- 10780754
TI - Respiratory muscle activity in patients with COPD walking to exhaustion with and
without pressure support.
AB - The function of the diaphragm and other respiratory muscles during exercise in
chronic obstructive pulmonary disease (COPD) remains controversial and few data
exist regarding respiratory muscle pressure generation in this situation. The
inspiratory pressure/time products of the oesophageal and transdiaphragmatic
pressure, and the expiratory gastric pressure/time product during exhaustive
treadmill walking in 12 patients with severe COPD are reported. The effect of
noninvasive positive pressure ventilation during treadmill exercise was also
examined in a subgroup of patients (n=6). During free walking, the inspiratory
pressure/time products rose early in the walk and then remained level until the
patients were forced to stop because of intolerable dyspnoea. In contrast, the
expiratory gastric pressure/time product increased progressively throughout the
walk. When patients walked the same distance assisted by noninvasive positive
pressure ventilation, a substantial reduction was observed in the inspiratory and
expiratory pressure/time products throughout the walk. When patients walked with
positive pressure ventilation for as long as they could, the pressure/time
products observed at exercise cessation were lower than those observed during
exercise cessation after free walking. It is concluded that, in severe chronic
obstructive pulmonary disease, inspiratory muscle pressure generation does not
increase to meet the demands imposed by exhaustive exercise, whereas expiratory
muscle pressure generation rises progressively. Inspiratory pressure support was
shown to substantially unload all components of the respiratory muscle pump.
PMID- 10780755
TI - Predictors of weaning outcome in chronic obstructive pulmonary disease patients.
AB - Several threshold values for predicting weaning outcome from mechanical
ventilation have been proposed. These values, however, have been obtained in
nonhomogeneous patient populations. The aim of the present study was to determine
the threshold values in chronic obstructive pulmonary disease (COPD) patients and
compare them to those reported for nonhomogeneous patient populations. The
initial weaning trial included 81 COPD patients. Fifty-three of them underwent a
successful weaning trial, whereas 28 failed it. The latter were enrolled into the
present investigation, and were restudied during a subsequent successful trial.
The weaning indices used were those reported in the literature. The threshold
values obtained were within 10% of those reported for a nonhomogeneous patients
population only for tidal volume and effective compliance. The classification
error was <20% for maximal inspiratory pressure (MIP), occluded inspiratory
pressure swing (deltaPI)/MIP, rapid and shallow breathing (respiratory
frequency/tidal volume), and compliance, rate, oxygenation, pressure index
(CROP), whereas the area under the receiver operating characteristic curves was
>0.9 only for deltaPI/MIP and CROP. In conclusion, the threshold values obtained
in chronic obstructive pulmonary disease patients who failed the first weaning
attempt differed from those previously reported. Although a gold standard weaning
index is not available for chronic obstructive pulmonary disease patients, the
occluded inspiratory pressure swing/ maximal inspiratory pressure and compliance,
rate, oxygenation, pressure index may be candidates for such a role.
PMID- 10780756
TI - Comparison of the safety of drug delivery via HFA- and CFC-metered dose inhalers
in CAO.
AB - The objective of this study was to compare the long-term safety of a fixed
combination of fenoterol hydrobromide (50 microg) and ipratropium bromide (20
microg) delivered using a metered dose inhaler (MDI) formulated with a non
chlorinated propellant, hydrofluoroalkanel34a (HFA-MDI), with delivery using the
conventional chlorofluorocarbon propellant (CFC-MDI, Berodual/Bronchodual). The
study was designed according to Safety Assessment of Marketed Medicines (SAMM)
guidelines, to reflect as far as possible the use of MDls under normal
prescribing conditions. Two thousand and twenty-seven patients with chronic
airways obstruction (CAO) were enrolled from 99 centres in France, 95 centres in
Germany and 24 centres in Italy. Following a 2-week run-in period, patients were
randomized on a 2:1 basis (1,348 patients to HFA-MDI, 679 patients to CFC-MDI) to
receive a flexible dose regimen of the combination (2 puffs, 2-4 times a day, as
prescribed by the investigator) during a 12-week open label phase. The overall
incidence of adverse events was comparable between both groups. In addition, the
incidence of respiratory side effects was also similar, with CAO exacerbations or
bronchitis the most frequently recorded events. The safety profile of the HFA
formulation was comparable to those of the marketed CFC-MDIs used in Germany and
France/Italy. No clinically significant differences were detected between HFA134a
or CFC driven inhalers on the switch from CFC- to HFA-MDI (2 weeks before
randomisation versus 2 weeks after randomization). There was a trend for taste
complaints to be reported more frequently by patients in the HFA-MDI group (0.7%
before randomization versus 3.4% after randomization). This, however, was an
expected finding as the HFA134a formulation does have a different taste to the
CFC formulation. No difference between formulations was observed in the
incidences of coughing or paradoxical bronchospasm. The incidence of falls in
FEV1 >15% within 15 min following inhalation at each of the clinic visits was
1.2% for both CFC- and HFA-MDIs. In conclusion, administration of a
fenoterol/ipratropium bromide combination via hydrofluoroalkane-metered dose
inhaler is as safe as delivery by the currently available chlorofluorocarbon
metered dose inhaler, in an extended population of patients with CAO under normal
prescribing conditions.
PMID- 10780757
TI - Split-night versus full-night studies for sleep apnoea/hypopnoea syndrome.
AB - Investigation and treatment of sleep apnoea/hypopnoea syndrome (SAHS) is placing
increasing demands on healthcare resources. This workload may be reduced by using
split-night studies instead of the standard full-nights of diagnostic
polysomnography and continuous positive airway pressure (CPAP) titration. Split
night studies involve polysomnography in the first half of the night followed, if
there is an abnormal frequency of apnoeas and hypopneas, by CPAP titration for
the remainder of the night. The authors' database of all patients prescribed a
CPAP trial 1991-1997 was used to compare long-term outcomes in all 49 (46
accepting CPAP) patients prescribed split-night studies with those in full-night
patients, matched 1:2 using an apnoea/ hypopnoea index (AHI) of +/-15% and
Epworth score of +/-3 units. Classical symptoms of SAHS were the main reason for
the split-night studies (n=27). There were no differences between the groups in
long-term CPAP use, median nightly CPAP use (split-night 6.0 h x night-1,
interquartile range (IQR) 3.8-7.4, full-night; 6.2 h x night-1, IQR 3.7-7.0,
p=0.9), post-treatment Epworth scores and frequency of nursing
interventions/clinic visits required. The median time from referral to treatment
was less for the split-night patients (13 months, IQR 11-20 months) than for full
night patients (22 months, IQR 12-34 months; p=0.003). Split-night studies, in
selected patients, result in equivalent long-term continuous positive airway
pressure use to full-night studies with shorter treatment times and less
healthcare utilization.
PMID- 10780758
TI - Long-term effects of CPAP on daytime functioning in patients with sleep apnoea
syndrome.
AB - Daytime sleepiness, impaired cognitive performance and dysphoric mood are often
present in patients with obstructive sleep apnoea syndrome (SAS). This
prospective controlled study evaluates the effects of treatment with continuous
positive airway pressure (CPAP) during 1 yr on daytime functioning in a large
group of patients with SAS. The authors studied 80 patients (mean+/-sem 49+/-1
yrs) with SAS with a mean apnoea-hypopnoea index of 60+/-2 h-1, and 80 healthy
control subjects matched for sex and age (46+/-1 yrs.). Measurements were
obtained at the beginning of the study and 12+/-1 months later, and included:
daytime sleepiness (Epworth scale), depression and anxiety (Beck tests),
vigilance (Steer-Clear) and reaction time (Psychometer Vigilance Test 192). Drug,
coffee and alcohol intake, as well as the sleep schedule, were also recorded.
Results showed that, before treatment, patients were more somnolent (p<0.001),
anxious (p<0.01) and depressed (p<0.001) than control subjects. Also, they had a
longer reaction time (p<0.05) and poorer vigilance (p<0.01). The use of CPAP
improved significantly the levels of somnolence (p<0.0001) and vigilance
(p<0.01), but failed to modify anxiety and depression. Reaction time changes were
minor. Variables with a potential confounding effect did not change during the
study. These results provide firm evidence to substantiate the use of continuous
positive airway pressure in patients with sleep apnoea syndrome.
PMID- 10780759
TI - Airway inflammation, airway responsiveness and cough before and after inhaled
budesonide in patients with eosinophilic bronchitis.
AB - Eosinophilic bronchitis is a common cause of chronic cough, characterized by
sputum eosinophilia similar to that seen in asthma, but unlike asthma the
patients have no objective evidence of variable airflow obstruction or airway
hyperresponsiveness. The reason for the different functional associations is
unclear. The authors have tested the hypothesis that in eosinophilic bronchitis
the inflammation is mainly localized in the upper airway. In an open study the
authors measured the lower (provocative concentration causing a 20% fall in
forced expiratory volume in one second (PC20)) and upper (PC25 MIF50) airway
responsiveness to histamine, lower and upper airway inflammation using induced
sputum and nasal lavage, in II patients with eosinophilic bronchitis. The authors
assessed changes in these measures and in cough reflex sensitivity to capsaicin
and cough severity after 400 microg of inhaled budesonide for 4 weeks. A nasal
eosinophilia was present in only three patients with one having upper airway
hyperresponsiveness. Following treatment with inhaled corticosteroids the
geometric mean sputum eosinophil count decreased from 12.8% to 2.9% (mean
difference 4.4-fold, 95% confidence interval (CI) 2.14-10.02), the mean +/- sem
cough visual analogue score on a 100 mm scale decreased from 27.2 +/- 6.6 mm to
12.6 +/- 5.7 mm (mean difference 14.6, 95% CI 9.1-20.1) and the cough sensitivity
assessed as the capsaicin concentration required to cause two coughs (C2) and
five coughs (C5) improved (C2 mean difference 0.75 doubling concentrations, 95%
CI 0.36-1.1; C5 mean difference 1.3 doubling concentration, 95% CI 0.6-2.1).
There was a significant positive correlation between the fold change in sputum
eosinophil count and doubling dose change in C5 after inhaled budesonide
(r=0.61). It is concluded that upper airway inflammation is not prominent in
eosinophilic bronchitis and that inhaled budesonide improves the sputum
eosinophilia, cough severity and sensitivity suggesting a causal link between the
inflammation and cough.
PMID- 10780760
TI - Effects of inhaled steroids on methacholine-induced bronchoconstriction and gas
trapping in mild asthma.
AB - According to a recent hypothesis, airway smooth muscle regulates airway calibre
mostly at high lung volume, whereas the mucosa and adventitia dimensions dominate
at low lung volumes. It was thought that if inhaled steroids decrease the
thickness of airway wall in asthma, then forced vital capacity (FVC), which
reflects the functional changes at low lung volume, should decrease less during
induced bronchoconstriction than flow at high volume. The study was conducted in
31 mild asthmatics under control conditions and during a methacholine challenge
before and after 4-weeks treatment with inhaled fluticasone dipropionate (1.5 mg
daily, 16 patients) or placebo (15 patients). After fluticasone dipropionate
treatment, control forced expiratory volume in one second (FEV1), and maximal
flow at 50% of control FVC during forced expiration after a maximal (V'max,50)
and a partial inspiration (V'p,50) significantly increased. During methacholine
challenge, FVC decreased less than did FEV1 or V'max,50, and so did inspiratory
vital capacity compared to V'p,50. Both the provocative dose of methacholine
causing a 20% fall in FEV1 and the bronchodilator effect of deep inhalation
significantly increased. The latter was assessed by means of the regression
coefficient of all V'max,50 plotted against V'p,50. No significant changes in
these parameters occurred after placebo. These data show that inhaled steroids
remarkably blunt the occurrence of gas trapping during induced
bronchoconstriction in mild bronchial asthma, possibly due to their effect on
airway wall remodelling.
PMID- 10780761
TI - Efficacy and duration of action of the antileukotriene zafirlukast on cold air
induced bronchoconstriction.
AB - The objectives of the study were to assess the magnitude of the effect of the
leukotriene receptor antagonist, zafirlukast, against cold air-induced
bronchoconstriction following the first dose and to assess magnitude and duration
after 5 days of dosing. Nineteen patients with asthma were included. In a
randomized cross-over design, either zafirlukast 20 mg or 80 mg b.d. or placebo
were given over 5 days. Challenges were performed 3 h post first dose and 3, 8,
12 and 24 h post last dose. The authors assessed the provocative ventilation rate
necessary to achieve a 10% (PV10) and 20% (PV20) fall in forced expiratory volume
in one second. The median PV20 3 h post first dose was 69.1 L x min-1 for
zafirlukast 80 mg compared to 40 L x min-1 for placebo (p=0.004). The
corresponding median value for zafirlukast 20 mg was 59.9 L x min-1 (p=0.06). At
steady state the differences in PV20, between zafirlukast 80 mg and placebo were
significant at 8 h and 12 h post last dose. The corresponding difference for
zafirlukast 20 mg was statistically significant at 8 h post last dose. The
analysis of PV10 yielded compatible results. There was no significant protection
24 h after last dose. This study has demonstrated that zafirlukast offers
significant protection against cold air-induced bronchoconstriction in asthma.
The degree and duration of protection were dose-dependent. However, there was a
large interindividual variability for the protective effect of this leukotriene
receptor antagonist.
PMID- 10780762
TI - Acute effects of air pollution on respiratory health of 50-70 yr old adults.
AB - The aim of this study was to investigate the association between daily changes in
respiratory health and air pollution in 489 adults, aged 50-70 yrs, with and
without chronic respiratory symptoms, living in urban and nonurban areas in the
Netherlands. Subjects were selected from the general population with a screening
questionnaire. During three consecutive winters starting in 1992/1993, peak
expiratory flow (PEF) and respiratory symptoms were registered in a daily diary.
Daily measurements of particles with a 50% cut-off aerodynamic diameter of 10
microm (PM10), black smoke (BS), sulphate, sulphur dioxide (SO2) and nitrogen
dioxide (NO2) were conducted. The difference in PM10, BS and sulphate
concentrations between urban and nonurban areas was small, but there was more
contrast in the concentrations of SO2 and NO2. In symptomatic subjects from urban
areas, PM10, BS, sulphate and SO2 concentrations were associated with the
prevalence of large decrements in morning PEF (>20% below the median). BS in
particular was also associated with upper respiratory symptoms (URS). The
magnitude of the effect estimates was in the order of an 80% increase in PEF
decrements and a 20% increase in URS for a 40 microg x m-3 increase of the same
day BS concentration. In symptomatic subjects from nonurban areas, no consistent
associations between air pollution and health indicators were observed. However,
the differences in effect estimates between urban and nonurban symptomatic panels
were small and nonsignificant. In nonsymptomatic adults from both areas, no
consistent pattern of associations with air pollution was found. In conclusion,
air pollution effects were only found in symptomatic adults in the urban areas.
PMID- 10780763
TI - Risk factors for bronchial hyperresponsiveness in workers exposed to acid
anhydrides.
AB - Risk factors for bronchial hyperresponsiveness have previously been established
in the general community. In settings where occupational asthma is a risk, it has
not been established whether occupational sensitization or measures of exposure
are important. Bronchial responsiveness to histamine was measured in a cohort of
506 workers exposed to acid anhydrides. Skin-prick tests were performed with
conjugates of phthalic, maleic and trimellitic anhydride with human serum albumin
and with common inhalant allergens. Employment and smoking histories were
recorded. Occupational exposure was measured using personal air samplers and
estimates of past exposure made by retrospective exposure assessment. Three
hundred and seventy workers (73%) had bronchial responsiveness measured (median
age 39 yrs, range 18-77) and 46 (12%) of these were hyperresponsive (provocative
dose causing a 20% fall in forced expiratory volume in one second (FEV1; PD20) <
or = 8 micromol). Twelve (3%) of these responsive workers had a skin-prick test
reaction to an acid anhydride conjugate, 124 (34%) to a common inhalant allergen,
and 148 (40%) were current smokers. Multivariate analysis showed that
occupational sensitization, sensitization to a common inhalant allergen, age, and
pack-years of smoking were independent risk factors for bronchial
hyperresponsiveness. Of these only occupational sensitization was completely
independent of baseline FEV1. It is concluded that sensitization to acid
anhydrides is a significant risk factor for bronchial hyperresponsiveness.
However, measures of personal acid anhydride exposure were not associated with
bronchial hyperresponsiveness.
PMID- 10780765
TI - Prevalence of asthma in 13-14 yr-old schoolchildren across Israel.
AB - There is evidence that the incidence and severity of asthma are increasing
worldwide, but there are limited data on asthma in Israel. The aim of this study
was to investigate the prevalence and severity of asthma and asthma symptoms in
13-14 yr-old schoolchildren in Israel. The self-completed questionnaire used was
a modified version of that developed by the International Study of Asthma and
Allergies in Childhood (ISAAC), and was administered to a national sample of
12,918 children. The prevalence of asthma ever, wheezing ever and wheezing in the
last 12 months were 13.7, 23.8 and 17.9% respectively. Significantly higher rates
of a history of asthma and asthma symptoms were observed in Jews compared with
Arabs. Although asthma ever was more prevalent in males than in females, asthma
symptoms were significantly more common in females. The type of area of residence
had no effect on the prevalence of wheezing. The ethnic differences in the
prevalence of asthma persisted after controlling for sex, district of residence
and level of urbanization. The prevalence of both asthma and asthma symptoms in
Israel are slightly above the mean reported from 10 other countries in Europe and
the Far-East.
PMID- 10780764
TI - Short-term exposure to air pollution in a road tunnel enhances the asthmatic
response to allergen.
AB - The aim of this study was to assess whether air pollution in road tunnels would
promote asthmatic reactions in persons with mild allergic asthma. Twenty
volunteers with mild allergic asthma were exposed, inside a car, for 30 min in a
Stockholm city road tunnel. As a control, the subjects were exposed to much lower
pollution levels in a suburban area. Four hours after the exposure, the subjects
inhaled a low dose of allergen. Asthmatic reaction during the early phase was
measured as the increase in specific airway resistance 15 min after allergen
inhalation and during the late phase as the decrease in lung function forced
expiratory volume in one second 3-10 h after allergen inhalation. Asthma symptoms
and drug use were monitored up to 18 h after allergen inhalation. The median
nitrogen dioxide level during exposure was 313 microg x m-3 (range 203-462). The
median levels of particles with 50% cut-off aerodynamic diameters of 10 (PM10)
and 2.5 microm (PM2.5) were 170 (range 103-613) and 95 (range 61-218) micro x m
3, respectively. Subjective symptoms during tunnel exposure were not pronounced.
However, subjects exposed to tunnel N02 levels of > or = 300 microg x m-3 had a
significantly greater early reaction, following allergen exposure, as well as
lower lung function and more asthma symptoms during the late phase, compared to
control. Also, subjects with PM2.5 exposure > or = 100 microg x m-3 had a
slightly increased early reaction compared to control. In conclusion, exposure to
air pollution in road tunnels may significantly enhance asthmatic reactions to
subsequently inhaled allergens.
PMID- 10780766
TI - Exhaled nitric oxide in asthmatic children exposed to relevant allergens: effect
of flunisolide.
AB - Inhaled corticosteroids are capable of reducing the level of exhaled nitric oxide
(expiratory nitric oxide fraction (FE,NO)) in asthmatic patients in a dose
dependent fashion. The aim of this study was to evaluate whether or not treatment
with an inhaled steroid can prevent changes in FE,NO after the exposure to
relevant allergens, following avoidance, in asthmatic children allergic to house
dust mite. Thirty-two house dust mite-allergy asthmatic children were randomly
allocated to treatment with inhaled flunisolide (500 microg b.i.d) or placebo and
evaluated before and 2 weeks after a period of natural exposure to mite antigens.
Lung function and FE,NO were evaluated. FE,NO was increased in the placebo
treated group after antigen exposure. Treatment with inhaled flunisolide
prevented such increase in FE,NO (p<0.001). No change was observed in lung
function parameters. Inhaled flunisolide is effective in preventing the increase
in airway inflammation observed in allergic asthmatic children re-exposed to
allergens.
PMID- 10780767
TI - Cartilaginous airway wall dimensions and airway resistance in cystic fibrosis
lungs.
AB - It is not clear how airway pathology relates to the severity of airflow
obstruction and increased bronchial responsiveness in cystic fibrosis (CF)
patients. The aim of this study was to measure the airway dimensions of CF
patients and to estimate the importance of these dimensions to airway resistance
using a computational model. Airway dimensions were measured in lungs obtained
from CF patients who had undergone lung transplantation (n=12), lobectomy (n=1),
or autopsy (n=4). These dimensions were compared to those of airways from
lobectomy specimens from 72 patients with various degrees of chronic obstructive
pulmonary disease (COPD). The airway dimensions of the CF and COPD patients were
introduced into a computational model to study their effect on airway resistance.
The inner wall and smooth muscle areas of peripheral CF airways were increased
3.3- and 4.3-fold respectively compared to those of COPD airways. The epithelium
was 53% greater in height in peripheral CF airways. The sensitivity and maximal
plateau resistance of the computed dose/response curves were substantially
increased in the CF patients compared to COPD patients. The changes in airway
dimensions of cystic fibrosis patients probably contribute to the severe airflow
obstruction, and to increased bronchial responsiveness, in these patients.
PMID- 10780768
TI - Endothelin-1 production is associated with eosinophilic rather than neutrophilic
airway inflammation.
AB - Endothelin-1 (ET-1) is a strong bronchoconstrictor which possesses pro
inflammatory properties and is claimed to be an important mediator in bronchial
asthma. The present study was undertaken to investigate whether ET-1 synthesis,
in an inflammation dominated by neutrophilic granulocytes, is as pronounced as
previously demonstrated in an airway inflammation dominated by eosinophils.
Moreover, the authors compared the production of ET-1 and tumour necrosis factor
(TNF)-alpha in rat lungs following intratracheal instillation of either
lipopolysaccharide (LPS) (neutrophilic inflammation) or Sephadex (SDX)
(eosinophilic). The lung tissue ET-1 messenger ribonucleic acid (mRNA) expression
was not increased in LPS treated animals whereas a six-fold increase was measured
after 30 min in the SDX group (p<0.05). TNF-alpha mRNA signals increased early
following LPS instillation, peaking at 2 h, whereas elevated TNF-alpha mRNA in
the SDX model was observed at 24 h. The ET-1 concentrations in bronchoalveolar
lavage fluid (BALF) rose slightly, but significantly, 3 h after both LPS and SDX
exposure. At 24 h no further rise in ET-1 levels was observed in the LPS model,
while a substantial increase in the ET-1 concentration was measured in the SDX
group (p<0.05). The TNF-alpha concentrations in BALF rose considerably at 3 h in
the LPS group, but was nearly abolished at 24 h. In SDX challenged animals
however, an increase in BALF-TNF-alpha did not occur until 24 h postchallenge. In
conclusion, intratracheal instillation of lipopolysaccharide, leading to a purely
neutrophilic lung inflammation, does not induce synthesis of endothelin-1. This
is in contrast to observations during an eosinophilic airway inflammation,
indicating a specific role of endothelin-1 in lung inflammations dominated by
eosinophils. In contrast to in vitro experiments, no evidence for induction of
endothelin-1 synthesis was observed by high levels of tumour necrosis factor
alpha in vivo.
PMID- 10780770
TI - Epidemiology of community-acquired pneumonia in adults: a population-based study.
AB - In this prospective study, the authors assessed the incidence, aetiology, and
outcome of patients with community-acquired pneumonia in the general population.
From December 1993 to November 1995, a study was performed in a mixed residential
industrial urban population of the "Maresme" region in Barcelona, Spain. All
subjects > or =14 yrs of age (annual average population size 74,368 inhabitants)
with clinically suspected community-acquired pneumonia were registered. All cases
were re-evaluated by chest radiographs on the 5th day of illness and at monthly
intervals until complete recovery. Urine and blood samples were obtained for
culture and antigen detection. When lower respiratory tract secretions were
obtained, these were also cultured. There were 241 patients with community
acquired pneumonia, with an annual incidence rate of 1.62 cases (95% confidence
interval, 1.42-1.82) per 1,000 inhabitants. Incidence rates increased by age
groups and were higher in males than in females. Of 232 patients with
aetiological data, 104 had an identifiable aetiology. A total of 114 pathogens
were found (single pathogen 94, two pathogens 10). There were 81 episodes of
bacterial infection and 33 of viral infection. The most common pathogens were
Streptococcus pneumoniae, Chlamydia pneumoniae, and influenza A and B viruses. No
case of Hantavirus infection was found. The rate of hospital admission was 61.4%
with a mean+/-SD length of 11.7+/-10.1 days, a mean period of 23.0+/-14.3 days
inactivity, and an overall mortality rate of 5%. The high rate of hospital
admission, prolonged stay in hospital, and long period of inactivity all continue
to constitute a social and health care burden of community-acquired pneumonia.
PMID- 10780769
TI - Selectivity of cyclo-oxygenase inhibitors in human pulmonary epithelial and
smooth muscle cells.
AB - Cyclo-oxygenase (COX) inhibitors may have a role in reducing inflammation in
asthma and other pulmonary diseases. COX inhibitors have different selectivities
for the two COX isoenzymes (COX 1 and COX 2) which vary between purified enzyme
and intact cell preparations. The relative selectivity of COX inhibitors has not
been studied in human airway cells. A number of COX inhibitors in cultured human
airway cells were compared which exclusively express either COX 1 (primary degree
cultured human airway smooth muscle (HASM) cells) or COX 2 (A549 pulmonary
epithelial cell-line) as measured by Western blotting. COX activity was assayed
by prostaglandin (PG)E2 production following 30 min incubation with 5 mM
arachidonic acid. COX activity in both cell types was similar; HASM cells 92.2+/
12.1 ng PGE2 x mg-1 protein, A549 cells 87.7+/-24.4 ng PGE2 mg-1 protein. In HASM
cells the median inhibitory concentration (IC50) was >10-5 M for nimesulide, 3.2
x 10-6 M for N-(2-cyclohexyloxy-4-nitrophenyl)-methanesulphonamide (NS398), 1.8 x
10-8 M for flurbiprofen, 6.7 x 10-9 M for indomethacin and >10-5 M for aspirin.
In A549 cells the IC50 was 1.8 x 10-9M for nimesulide, 4.1 x 10-9 M for NS398,6.2
x 10-10 M for flurbiprofen, 1.3 x 10-8 M for indomethacin and >10-5 M for
aspirin. Sodium valerate had no effect in either HASM or A549 cells. The COX
2:COX 1 selectivity ratio (COX 2 IC50/COX I IC50) was <0.0001 for nimesulide,
0.001 for NS398, 0.03 for flurbiprofen and 1.9 for indomethacin. In conclusion
the present study has shown that cyclo-oxygenase inhibitors have a range of
selectivities for cyclo-oxygenase 1 and cyclo-oxygenase 2 in intact human airway
cells. The relative cyclo-oxygenase 2 selectivity of N-(2-cyclohexyloxy-4
nitrophenyl)-methanesulphonamide and nimesulide may have implications for the
treatment of asthma and other inflammatory pulmonary diseases.
PMID- 10780771
TI - Tumour necrosis factor-alpha production in human alveolar macrophages: modulation
by inhaled corticosteroid.
AB - Using an ex vivo alveolar macrophage model, the hypothesis that inhaled
preparations of corticosteroids might have important anti-inflammatory effects on
cells of the peripheral airway was tested. The tumour necrosis factor (TNF)-alpha
inducing potential of three glycolipid preparations from nonpathogenic
(arabinofuranasyl lipoarabinomannan (LAM (Ara-LAM)) and virulent (mannase LAM
(ManLAM)) mycobacteria and Gram-negative bacteria (lipopolysaccharide (LPS)), in
primary alveolar macrophage preparations was investigated. A novel inhaled
chlorofluorocarbon (CFC)-free preparation of beclomethasone dipropionate
(hydrofluoroalkane 134a (HFA)-BDP) with increased peripheral lung deposition was
investigated for its ability to modulate glycolipidinduced TNF-alpha production
by human alveolar macrophages, in comparison with a CFC-containing preparation
and placebo. Compared to the basal TNF-alpha bioactivity of 0.72 ng x mL-1
(geometric mean), the TNF-alpha bioactivity in the macrophage preparation
increased following incubation with LPS (138 ng x mL-1, p<0.001), AraLAM (12.6 ng
mL-1, p<0.001) and ManLAM (1.42 ng x mL-1, p=0.02). HFA-BDP, administered in
vivo, significantly reduced LPS- and ManLAM-induced TNF-alpha production by
alveolar macrophages cultured ex vivo. No change in glycolipid-induced TNF-alpha
production was observed following in vivo administration of CFC-BDP or HFA
placebo. This is the first demonstration of an immunomodulatory effect on
alveolar cells of corticosteroid delivered via metered dose inhaler. The present
findings suggest that alveolar deposition of beclomethasone dipropionate is
capable of modulating the inflammatory potential of the alveolar macrophage
population.
PMID- 10780772
TI - Restoration by vacuum inflation of original alveolar dimensions in small human
lung specimens.
AB - Resection of lung specimens results in deflated and distorted lung structures. If
no major airway is present (as in the case of small lung specimens from
biopsies), lung dimensions cannot be restored by inflation under 25 cmH20. This
impedes morphological analysis of the tissue. This report describes a simple and
easy procedure to restore alveolar dimensions in deflated small lung specimens.
Small human lung samples were inflated using moderate vacuum conditions which are
provided by a common water stream-driven vacuum device. Restoration of alveolar
dimensions and morphology was evaluated for paraffin-embedded as well as frozen
tissue, using morphometric and immunohistological analysis. Vacuum inflation
results in restoration of original lung dimensions as judged by light and
scanning electron microscopy, and by analysis of the mean linear intercept, and
the average length, width, perimeter and surface area. It also results in
markedly improved cutting characteristics, allowing reliable sectioning of 2
microm cryosections and achieving high resolution images in immunofluorescence.
Vacuum inflation is a simple and easy procedure to restore lung architecture of
small human lung specimens/biopsies with a concomitant improvement of cutting
characteristics. It allows for correct histological analysis of small specimens
which cannot be inflated otherwise.
PMID- 10780773
TI - Validation of assays for inflammatory mediators in sputum.
AB - Commercially available immune assays are being used with increasing frequency in
the study of lung inflammation. However, their performance in complex biological
fluids is rarely assessed. The authors wished to assess their reliability to
determine whether the results obtained in sputum samples can be easily
interpreted. The reproducibility of several such assays was therefore determined
together with their ability to recover known amounts of pure reagent. Sputum sol
phase was obtained from several patients with chronic lung disease and used
together with the reagents in a series of "spiking" and dilutional experiments.
Results confirmed that the enzyme assay for myeloperoxidase and the immune assays
for interleukin-8, leukotriene B4 and secretory leukoproteinase inhibitor were
all reproducible (intra-assay coefficient of variation 3.8-7.7%). Furthermore,
each of these assays gave >85% recovery of a "spike" with pure reagent. However,
the immune assay for myeloperoxidase (although reproducible) gave poor recovery
and was dependent on the degree of sample dilution and elastase content. These
studies confirm that the reliabilities of fluid phase measurements should be
assessed before being widely applied to complex biological samples.
PMID- 10780774
TI - Airway smooth muscle in health and disease; methods of measurement and relation
to function.
AB - Smooth muscle is present and probably functional in the airways in utero and
increases in absolute area during growth with little further change during
adulthood. It encircles the entire airway below the level of the main bronchus,
in a roughly circular orientation, except at high lung volumes. It occupies
relatively more of the airway wall in the peripheral airways, reaching a maximum
in the membranous bronchioles. Measurement of smooth muscle area in the airway
wall is confounded by clinical classification of cases, methods of tissue
retrieval and preparation, staining and orientation of sections, magnification,
image analysis and statistical methods of comparison between groups. Airway
smooth muscle area is pathologically increased in inflammatory conditions of the
airways such as chronic obstructive pulmonary disease, in relation to airways
obstruction, and asthma, in relation to severity and airway size (between 25 and
250% compared with control cases). It is increased in sudden infant death
syndrome, but there are few studies in other conditions such as bronchiectasis.
In asthma, smooth muscle must shorten (not necessarily to an abnormal degree) for
the structural abnormalities of the airway to manifest as excessive airway
narrowing. Not surprisingly there is renewed interest in the relationships
between the mechanical and contractile properties of smooth muscle, parenchymal
properties and lung volume and how these interact to determine smooth muscle
length. The relative importance of smooth muscle area and mechanical properties,
altered airway structure and airway inflammation in disease are yet to be
determined.
PMID- 10780776
TI - Endobronchial tuberculosis with expectoration of tracheal cartilages.
AB - A case of endotracheal tuberculosis with expectorations of the lateral one-third
of the multiple tracheal cartilages is reported. Fibreoptic bronchoscopy revealed
caseous materials and loosening of the tracheal cartilages. The patient
expectorated cartilaginous material several times before and after fibreoptic
bronchoscopy. In spite of the loss of tracheal cartilages, tracheal lumen was
maintained with a mild airflow limitation. The remaining two-thirds of the
tracheal cartilage rings seemed to be strong enough to support the tracheal lumen
opening during the respiratory cycle. Although rare, expectoration of bronchial
cartilage can be one of the clinical features of endobronchial tuberculosis.
PMID- 10780775
TI - The pathogenesis of lung injury following pulmonary resection.
AB - Postpneumonectomy pulmonary oedema (PPO) develops in approximately 5% of patients
undergoing pneumonectomy or lobectomy, and has a high associated mortality
(>50%). In its extreme form, PPO follows a clinical and histopathological course
indistinguishable from acute respiratory distress syndrome. Perioperative fluid
overload, impaired lymphatic drainage following node dissection and trauma caused
by surgical manipulation have been implicated in the pathogenesis of PPO.
However, PPO more probably represents the pulmonary manifestation of a
panendothelial injury consequent upon inflammatory processes induced by the
surgical procedure, which involves collapse and re-expansion of the operative
lung to permit hilar dissection and pulmonary resection. High inspired oxygen
concentrations are required to overcome the effects of shunt. Animal studies have
shown that pulmonary ischaemia/reperfusion can result in oedema formation,
possibly due to the generation of pro-oxidant forces. Moreover, plasma taken from
patients undergoing lobectomy or pneumonectomy (but not lesser resections) shows
evidence of oxidative damage. Such evidence suggests either that the high
inspired oxygen concentrations associated with one-lung ventilation, or
ischaemia/reperfusion injury, may modulate post-pneumonectomy pulmonary oedema.
Mechanisms by which redox imbalance may result in tissue damage and
postpneumonectomy pulmonary oedema are discussed.
PMID- 10780777
TI - Chronic interstitial lung disease due to Epstein-Barr virus infection in two
infants.
AB - This case study reports on two infants, 5 and 6 months of age, respectively, with
chronic interstitial lung disease who presented with failure to thrive,
tachypnoea, rales and mild hypoxaemia. Epstein-Barr virus (EBV) was detected by
in situ hybridization in lung biopsy specimens and by EBV-deoxyribonucleic acid
polymerase chain reaction (PCR) in bronchoalveolar lavage (BAL) fluid in one
patient and by in situ hybridization and PCR analysis in BAL fluid in the second
patient. There was serological evidence of immunoglobulin G antibodies to EBV
capsid antigen by indirect immunofluorescence in both patients. After 7 months of
respiratory symptoms one patient was successfully treated with a 10 day course of
intravenous ganciclovir followed by oral acyclovir for 20 days. The other patient
became symptom free after 3.5 months of respiratory symptoms, without any
specific antiviral medication. During a follow-up of 2 and 1.5 yrs, respectively,
both infants remained symptom free and showed normal physical development.
PMID- 10780778
TI - "The skeletal muscle in chronic respiratory diseases", summary of the ERS
research seminar in Rome, Italy, February 11-12 1999.
PMID- 10780779
TI - FRAXE mutation in a mentally retarded subject and in his phenotypically normal
twin brother.
AB - The FRAXE fragile site, 600 kb distal to the more common FRAXA, has been reported
to be expressed in subjects with mild non-syndromal mental retardation (MR).
Amplification of more than 200 GCC repeats, associated with methylation of the
adjacent CpG island at Xq28, leads to the expression of the fragile site. In 1996
a large gene, FMR2, transcribed distally from the CpG island and downregulated by
repeat expansion and methylation, was identified. Among 232 mentally retarded
patients, tested FRAXA negative, we identified an Italian family segregating a
hypermethylated expansion at the FRAXE locus in two dizygotic twin brothers,
their sister and their mother. The index case was referred at 23 years of age
with severe MR, epilepsy, a dysmorphic face with a high arched palate, marfanoid
habitus and hyperreflexia of the lower limbs. His brother was referred to as
normal and psychometric tests confirmed he is not mentally retarded. All members
of the family underwent FRAXE molecular analysis, after cytogenetic expression of
the fraX site and negative FRAXA test. Interestingly, an expansion and a
hypermethylation at the FRAXE locus were found in all of them. Fibroblasts from
the clinically normal brother were assayed for FMR2 expression and the
transcription of the gene was found to be silenced. The presence of a
phenotypically normal male with absent FMR2 expression in fibroblasts suggests
that the relationship between the FRAXE mutation, FMR2 expression and MR needs to
be further investigated.
PMID- 10780780
TI - Genomic structure of the gene for the human P1 protein (MCM3) and its exclusion
as a candidate for autosomal recessive polycystic kidney disease.
AB - The locus PKHD1 (polycystic kidney and hepatic disease 1) has been linked to all
typical forms of the autosomal recessive polycystic kidney disease (ARPKD) and
maps to chromosome 6p21.1-p12. We previously defined its genetic interval by the
flanking markers D6S1714 and D6S1024. In our current work, we have fine-mapped
the gene for the human P1 protein (MCM3), thought to be involved in the DNA
replication process, to this critical region. We have also established its
genomic structure. Mutation analyses using SSCP were performed in ARPKD patients'
cDNA samples, leading to the exclusion of this gene as a candidate for this
disorder. We also identified two intragenic polymorphisms that allowed families
with critical recombination events to be evaluated. Although neither marker was
informative in these individuals, they are the closest yet described for PKHD1
and may help to refine the candidate region.
PMID- 10780781
TI - FISH mapping of the sex-reversal region on human chromosome 9p in two XY females
and in primates.
AB - Accumulating evidence suggests that haploinsufficiency of a dosage-sensitive
gene(s) in human chromosome 9p24.3 is responsible for the failure of testicular
development and feminisation in XY patients with monosomy for 9p. We have used
molecular cytogenetic methods to characterise the sex-reversing 9p deletions in
two XY females. Fluorescence in situ hybridisation (FISH) with YACs from the
critical 9p region containing an evolutionarily conserved sex-determining gene,
DMRT1, is a very fast and reliable assay for patient screening. Comparative YAC
mapping on great ape and Old and New World monkey chromosomes demonstrated that
the critical region was moved from an interstitial position on the ancestral
primate chromosome to a very subtelomeric position in chimpanzee and humans by a
pericentric inversion(s). Pathological 9p rearrangements may be the consequence
of an evolutionary chromosome breakpoint in close proximity to the sex-reversal
region.
PMID- 10780782
TI - The human EZH2 gene: genomic organisation and revised mapping in 7q35 within the
critical region for malignant myeloid disorders.
AB - The EZH2 gene is a homolog of the Drosophila Polycomb group (PcG) gene enhancer
of zest, a crucial regulator of homeotic gene expression. Several lines of
evidence suggest a critical role for the EZH2 protein during normal and perturbed
development of the haematopoietic and central nervous systems. Indeed, the EZH2
protein has been shown to associate with the Vav proto-oncoprotein and with the
XNP protein, the product of a mental retardation gene. The EZH2 gene was
previously reported to be located on chromosome 21q22 and was proposed as a
candidate gene for some characteristics of the Down syndrome phenotype. We report
here the genomic structure and fine mapping of the EZH2 gene. We demonstrate that
the functional gene actually maps to chromosome 7q35 and that the sequence
previously isolated from a chromosome 21 cosmid corresponds to a pseudogene.
Finally, the nature of the EZH2 protein and its mapping to the critical region
for malignant myeloid disorders lead us to propose the EZH2 gene is involved in
the pathogenesis of 7q35-q36 aberrations in myeloid leukaemia.
PMID- 10780783
TI - Accuracy of family history of cancer: clinical genetic implications.
AB - Family medical history is the cornerstone of clinical genetic diagnosis and
management in cases of familial cancer. The soundness of medical decisions can be
compromised if reports by the family on affected relatives are inaccurate.
Although very time consuming, family medical histories are therefore routinely
verified. To investigate whether such verification is clinically justified, we
retrospectively analysed the accuracy of a consecutive series of 383 tumour
reports from counsellees on 120 families in our clinic. We evaluated these
families for the impact of verification on clinical genetic diagnosis and
management. Accuracy according to cancer type showed marked variation, ranging
from 93% and 89% for breast cancer and colorectal cancer, respectively, to 42%
and 37% for extra-colorectal alimentary tract cancer and uterine cancer. Accuracy
was related to the degree of kinship of the affected relative, but not to age and
gender of the counsellee, nor to the reason for referral or personal history of
cancer. Age at diagnosis and multiple primary tumours were reported accurately in
97% and 94% of cases, respectively. In six out of 120 families verification data
changed clinical genetic management, in five of these the genetic risk was
reduced. Although verification of all reported cancer cases in a family remains
the 'gold standard' for clinical as well as research purposes, verification of
reports on breast cancer can be limited without seriously compromising medical
decision making. In cases where verification is impossible because medical
records are unavailable, findings from studies such as ours may help in
interpreting family histories.
PMID- 10780784
TI - Potential relationship between genotype and clinical outcome in propionic
acidaemia patients.
AB - Propionic acidaemia (PA) is an autosomal recessive disorder caused by mutations
in either of the PCCA or PCCB genes which encode the alpha and beta subunits,
respectively, of the mitochondrial enzyme propionyl-CoA carboxylase (PCC). In
this work we have examined the biochemical findings and clinical outcome of 37
Spanish PA patients in relation to the mutations found in both PCCA and PCCB
genes. We have detected 27 early-onset and 101 late-onset cases, showing
remarkably similar biochemical features without relation to either the age of
onset of the disease or the defective gene they have. Twenty-one of the patients
have so far survived and three of them, now adolescents, present normal
development. Different biochemical procedures allowed us to identify the
defective gene in 9 PCCA deficient and 28 PCCB deficient patients. Nine putative
disease-causing mutations accounting for 77.7% of mutant alleles were identified
among PCCA deficient patients, each one carrying a unique genotypic combination.
Of PCCB mutant alleles 98% were characterised. Four common mutations (ins/del,
E168K, 1170insT and A497V) were found in 38/52 mutant chromosomes investigated,
whereas the remainder of the alleles harbour 12 other different mutations. By
examining the mutations identified both in PCCA and PCCB genes and the clinical
evolution of patients, we have found a good correlation between certain mutations
which can be considered as null with a severe phenotype, while certain missense
mutations tend to be related to the late and mild forms of the disease.
Expression studies, particularly of the missense mutations identified are
necessary but other genetic and environmental factors probably contribute to the
phenotypic variability observed in PA.
PMID- 10780785
TI - Characterization of a novel mitochondrial DNA deletion in a patient with a
variant of the Pearson marrow-pancreas syndrome.
AB - We have recently diagnosed a patient with anaemia, severe tubulopathy, and
diabetes mellitus. As the clinical characteristics resembled Pearson marrow
pancreas syndrome, despite the absence of malfunctioning of the exocrine pancreas
in this patient, we have performed DNA analysis to seek for deletions in mtDNA.
DNA analysis showed a novel heteroplasmic deletion in mtDNA of 8034bp in length,
with high proportions of deleted mtDNA in leukocytes, liver, kidney, and muscle.
No deletion could be detected in mtDNA of leukocytes from her mother and young
brother, indicating the sporadic occurrence of this deletion. During culture,
skin fibroblasts exhibited a rapid decrease of heteroplasmy indicating a
selection against the deletion in proliferating cells. We estimate that per cell
division heteroplasmy levels decrease by 0.8%. By techniques of fluorescent in
situ hybridisation (FISH) and mitochondria-mediated transformation of rho(o)
cells we could show inter- as well as intracellular variation in the distribution
of deleted mtDNA in a cell population of cultured skin fibroblasts. Furthermore,
we studied the mitochondrial translation capacity in cybrid cells containing
various proportions of deleted mtDNA. This result revealed a sharp threshold,
around 80%, in the proportion of deleted mtDNA, above which there was strong
depression of overall mitochondrial translation, and below which there was
complementation of the deleted mtDNA by the wild-type DNA. Moreover, catastrophic
loss of mtDNA occurred in cybrid cells containing 80% deleted mtDNA.
PMID- 10780786
TI - Physicians' attitudes towards mammography and prophylactic surgery for hereditary
breast/ovarian cancer risk and subsequently published guidelines.
AB - After a BRCA mutation has been identified in the context of hereditary
breast/ovarian cancer (HBOC), mammographic screening and prophylactic surgery are
two of the main options available to those responsible for the clinical
management of healthy women. The aim of this study was to describe the attitudes
of specialists towards the clinical management of women with an HBOC risk: this
information was collected prior to the publication of the recent French
guidelines. A random national sample of 1169 French surgeons, gynaecologists and
obstetricians was surveyed using a mailed questionnaire, to which 700 of these
physicians (60%) responded. When dealing with a BRCA mutated woman, 88.6% of the
respondents said they would recommend mammographic screening, but only 27.1%
would recommend that it should be carried out annually from the age of 30 years
onwards, as recommended in the French guidelines; 10.9% would find it acceptable
to propose prophylactic mastectomy from the age of 30 years, and 22.9% would find
it acceptable to propose prophylactic oophorectomy from the age of 35 years. The
specialists who agreed with recommending breast/ovarian cancer genetic testing
also had more positive attitudes towards prophylactic mastectomy (adj OR = 3.4,
95% CI = 1.4-8.2), as did those who had previously recommended prophylactic
mastectomy when gene testing was not yet available (adj OR = 2.06, 95% CI = 1.23
3.44). The respondents' attitudes towards prophylactic oophorectomy and
mastectomy were significantly associated (adj OR = 3.9; 95% CI = 2.3-6.5).
Previous recommendation of prophylactic mastectomy was associated (P < 0.01) with
a higher level of knowledge of breast/ovarian cancer genetics and with medical
practice in this field. French physicians' attitudes towards mammographic
screening and prophylactic surgery were not in complete agreement with the
subsequently published French guidelines, the impact of which has now to be
considered. Constantly evolving knowledge about the efficacy of preventive
intervention will give practitioners new elements to integrate into their
counselling.
PMID- 10780787
TI - Mechanism of spreading of the highly related neurofibromatosis type 1 (NF1)
pseudogenes on chromosomes 2, 14 and 22.
AB - Neurofibromatosis type 1 (NF1) is a frequent hereditary disorder that involves
tissues derived from the embryonic neural crest. Besides the functional gene on
chromosome arm 17q, NF1-related sequences (pseudogenes) are present on a number
of chromosomes including 2, 12, 14, 15, 18, 21, and 22. We elucidated the
complete nucleotide sequence of the NF1 pseudogene on chromosome 22. Only the
middle part of the functional gene but not exons 21-27a, encoding the
functionally important GAP-related domain of the NF1 protein, is presented in
this pseudogene. In addition to the two known NF1 pseudogenes on chromosome 14 we
identified two novel variants. A phylogenetic tree was constructed, from which we
concluded that the NF1 pseudogenes on chromosomes 2, 14, and 22 are closely
related to each other. Clones containing one of these pseudogenes cross
hybridised with the other pseudogenes in this subset, but did not reveal any in
situ hybridisation with the functional NF1 gene or with NF1 pseudogenes on other
chromosomes. This suggests that their hybridisation specificity is mainly
determined by homologous sequences flanking the pseudogenes. Strong support for
this concept was obtained by sequence analysis of the flanking regions, which
revealed more than 95% homology. We hypothesise that during evolution this subset
of NF1 pseudogenes initially arose by duplication and transposition of the middle
part of the functional NF1 gene to chromosome 2. Subsequently, a much larger
fragment, including flanking sequences, was duplicated and gave rise to the
current NF1 pseudogene copies on chromosomes 14 and 22.
PMID- 10780788
TI - WBSCR14, a putative transcription factor gene deleted in Williams-Beuren
syndrome: complete characterisation of the human gene and the mouse ortholog.
AB - Williams-Beuren syndrome (WBS) is a neurodevelopmental disorder affecting several
systems caused by a heterozygous deletion in the chromosomal region 7q11.23. A
common interval that includes up to 17 genes reported so far is deleted in the
great majority of patients. Elastin haploinsufficiency is responsible for the
cardiovascular features, but the specific contribution of other deleted genes to
the WBS phenotype remains unknown. We have fully characterised a gene commonly
deleted in WBS, WBSCR14, previously reported in a truncated form as WS-bHLH. The
WBSCR14 cDNA encodes an 852amino acid protein with a basic helix-loop-helix
leucine-zipper motif (bHLHZip) and a bipartite nuclear localisation signal
(BNLS), suggesting a function as a transcription factor. WBSCR14 is expressed as
a 4.2kb transcript predominantly in adult liver and at late stages of foetal
development. The WBSCR14 locus encompasses 33 kb of genomic DNA with 17 exons.
Two intragenic polymorphic dinucleotide repeats have been identified and used to
verify hemizygosity in WBS patients. We have also cloned the mouse ortholog and
mapped its locus to mouse chromosome 5, in a region of conserved synteny with
human 7q11.23. Given that other bHLHZip proteins are dosage sensitive and based
on the putative function of WBSCR14 as a transcription factor, hemizygosity at
this locus could be involved in some features of WBS.
PMID- 10780789
TI - Examination of trisomy 13, 18 and 21 foetal tissues at different gestational ages
using FISH.
AB - In man high levels of aneuploidy are seen in spontaneous abortions. Very few
autosomal trisomies survive to birth, the three most common being those for
chromosome 13, 18 and 21 giving rise to the syndromes named Patau, Edwards and
Down respectively. Since the majority of these spontaneously abort, what makes
the survivors different from the aborters? Could it be that they have tissue
specific mosaicism with the additional normal cell line supporting survival? In
this study fluorescence in situ hybridisation was used as a convenient way to
detect trisomy in interphase cells. To study the level of mosaicism across
gestation, different tissues from 21 trisomic foetuses were analysed using probes
for chromosome 13, 18, 21, X and Y. Two trisomy 18 foetuses exhibited mosaicism.
Two others, one trisomy 13 and one trisomy 18 had mosaic placentas. There was no
clear association between the limited mosaicism seen and severity of the
phenotype. We conclude that at least for this sample set, tissue-specific
mosaicism was not likely to be responsible for potential survival to birth.
PMID- 10780790
TI - Prenatal detection of a 17p11.2 duplication resulting from a rare recombination
event and novel PCR-based strategy for molecular identification of Charcot-Marie
Tooth disease type 1A.
AB - Charcot-Marie-Tooth disease, type 1A (CMT1A) is caused in most cases by a 1.5 Mb
duplication on chromosome 17p11.2 arising after unequal crossing-over between
repeated sequences called CMT1A-REPs, flanking the 1.5 Mb unit. A 3.2 kb
recombination hot spot has been defined, resulting in a junction fragment between
EcoRI (distal CMT1A-REP) and SacI (proximal CMT1A-REP). This was further reduced
to a 1.7kb EcoRI-NsiI fragment, and recently to a 731 bp hot spot region within
this fragment. We describe the CMT1A-REPs-based PCR method used to identify CMT1A
duplications and report on a family case in which a 29-year-old pregnant woman
requested prenatal diagnosis for two successive pregnancies because her husband
was affected with CMT1A. Our method enabled us to characterise the duplication in
both foetuses and demonstrate that it arose from a rare recombination event
taking place outside the 1.7 kb region. Since our approach is simple and enables
the entire set of duplications occurring after recombination in the enlarged
3.2kb region including the hot spot to be detected, we suggest it might be
considered for use in primary screening for pre- and postnatal diagnosis of
CMT1A.
PMID- 10780791
TI - DNA arrays: methods and applications: report on HUGO Meeting, Tartu, Estonia, 23
26 May, 1999.
PMID- 10780792
TI - Air pollution and allergy.
AB - Epidemiological studies have found a recent increase in the prevalence of
allergic diseases, especially in industrialized countries. A change in
environmental factors may be considered as one of the causes of this increase. It
has been reported that the prevalence of allergic diseases is higher in polluted
areas than in unpolluted ones. Therefore, we focused on the effect of one air
pollutant, suspended particulate matter (SPM), on allergic responses. We showed
that SPM had an enhancing effect on the IgE antibody production in mice. In
Japan, the number of cars with diesel engines has increased rapidly, and it has
been calculated that 35-80% of SPM in large cities consists of diesel exhaust
particulates (DEP). We demonstrated that DEP had an adjuvant effect on the IgE
antibody production in mice when administered intraperitoneally or intranasally.
In humans, it has been shown that nasal challenge with DEP enhanced total IgE and
specific IgE production in nasal lavages. Furthermore, it has been demonstrated
that DEP had an enhancing effect on Th2-type cytokine synthesis in both mice and
humans. It cannot be excluded that DEP may be related to the increase in
prevalence of allergic diseases through the effect on the IgE antibody production
and Th2-cytokine synthesis.
PMID- 10780793
TI - Eosinophils are neither migrated nor activated in the skin lesions of atopic
dermatitis in infants.
AB - Eosinophils and eosinophil cationic protein (ECP) were examined in the skin
lesions of 10 infants with atopic dermatitis (aged 4 months to 7 years). In all
10 patients, neutrophils and eosinophils were rarely seen in these lesions.
Moreover, in the immunohistochemical study, ECP was scarcely detected in any of
them. Our results suggest that eosinophils are neither migrated nor activated in
the skin in atopic dermatitis in infants.
PMID- 10780794
TI - Effects of allergen immunotherapy on the nasal mucosa in patients with allergic
rhinitis.
AB - Despite the varied immunological changes occurring after allergen immunotherapy,
the precise mechanism, or the mechanisms responsible for clinical effectiveness
of allergen immunotherapy have not been clearly determined. Postulated
immunomodulatory mechanisms include a decrease in cellular responsiveness, a
production of blocking antibodies, a reduction in the number of mast cells, and
activation of T-cell suppressor mechanisms. Nineteen allergic rhinitis patients
(study group) with house dust mite sensitivity and 10 nonallergic control
subjects were studied. In the study group, the nasal mucosal biopsies were
obtained prior to immunotherapy and were repeated after 1 year, and specimens
were evaluated by light and electron microscopy. After the third month of
immunotherapy, nasal symptom scores were reduced significantly and disappeared in
the sixth month (p <0.01). No significant changes were observed in the levels of
immunoglobulins, IgG subclasses and complement levels (p <0.05), except IgG4/IgG1
ratio (p <0.05). A comparison of histopathological findings of nasal mucosa in
each case revealed an improvement in epithelial loss, inflammation, thickening of
basal membrane and fibrosis (p <0.05). A significant correlation was observed
between epithelial loss and mast cell accumulation with symptom score (p <0.001).
These results suggest that the improvement of nasal epithelial cells and
reduction of mast cell accumulation in nasal mucosa may be one of the mechanisms
that could explain the improvement of nasal allergy symptoms following
immunotherapy.
PMID- 10780795
TI - Double-blind study of cetirizine and loratadine versus placebo in patients with
allergic rhinitis.
AB - The aim of this double-blind study was to evaluate the effectiveness of
cetirizine and loratadine versus placebo in patients with allergic rhinitis. The
study included a total of 90 patients suffering from moderate to severe allergic
rhinitis as determined by a symptom score, with hypersensitivity to house mites
and with high IgE. The study lasted 7 weeks, including 1 for pretreatment, 4 for
treatment and 2 posttreatment (washout). During the study, each patient received
either one tablet of placebo, 10 mg of cetirizine or 10 mg of loratadine daily.
The evaluation was carried out by rhinomanometry to analyze the symptoms on days
1, 15, 29 and 43. The nasal cytology was analyzed on days 1 and 29. For
statistical analysis we used the Mantel-Haenszel method and chi-square test. We
found that antihistamines showed good effectiveness in improving the
symptomatology in patients with allergic rhinitis. The improvement by
rhinomanometry and by symptom score versus placebo was good. It was concluded
that both antihistamines were significantly superior to placebo and that
cetirizine performed better in comparison to loratadine versus placebo, although
not as statistically significant.
PMID- 10780796
TI - Immune complexes IgE/IgG in airborne allergy: increase during pollen season.
AB - In the present study we addressed the question of IgE/IgG immune complex serum
level in 92 patients with respiratory allergy in relation to their clinical
status. Twenty patients with allergy to insect stings and 22 healthy volunteers
were also investigated. IgE/IgG immune complexes and IgG anti-IgE antibodies were
estimated using double antibody solid-phase immunoassays in IgG serum fractions
isolated by protein A affinity chromatography or in fractions obtained by
Sephacryl S-300 gel filtration. Three people (14%) from the control group, two
patients (10%) with insect allergy and 41 patients (45%) from the group with
airborne allergy exhibited an increased serum level of IgE/IgG immune complexes
(chi2, p <0.05). IgG anti-IgE serum level was also significantly higher in the
examined group of patients with airborne allergy than in the control group. None
of the factors analyzed, including the kind of allergic disease, the type of
inhalant allergen (pollen or house dust antigens), the severity of allergy judged
from the frequency and intensity of symptoms for 1 year preceding blood sampling
and the symptoms exhibited during blood sampling, showed a statistically
significant relation to the level of IgE/IgG immune complexes or IgG anti-IgE,
when the whole group of patients with respiratory allergy was analyzed. A
distinct difference between patients investigated during and outside of the
pollen season was found in patients with isolated pollen allergy. The latter
exhibited an increase of IgE/IgG immune complexes (57% vs. 29%) significantly
more often, which indicates the possible involvement of IgE/IgG immune complexes
in the pathogenesis of pollen allergy.
PMID- 10780798
TI - Immunoblot analysis for laboratory diagnosis of ataxia-telangiectasia: use of
Epstein-Barr virus-transformed or phytohemagglutinin-stimulated lymphoblasts for
detection of ATM protein.
AB - Ataxia-telangiectasia (A-T) is a genetic disorder characterized by a progressive
ataxia, immunodeficiency, neurological abnormalities, hypersensitivity to
ionizing radiation, and predisposition to cancer. The gene responsible for A-T
(ATM) has been cloned and shown to code for a 350 kDa polypeptide containing
3,056 amino acid residues. Detection of ATM mutations for laboratory diagnosis of
A-T is laborious and not practical, unless there are common mutations in a
population. We describe here immunoblot analysis for the detection of ATM in
seven Japanese A-T patients from five families and in controls using ATM3BA
antibody. ATM protein was routinely and clearly detected in Epstein-Barr virus
(EBV)-transformed or phytohemagglutinin (PHA)-stimulated lymphoblasts from
controls. However, it could not be detected consistently in unstimulated
peripheral blood mononuclear cells (PBMCs) from controls. We also detected ATM
protein in control fibroblasts, but the background was relatively higher than in
control lymphoblasts. ATM protein was not detected or dramatically decreased in
EBV-transformed lymphoblasts from all seven patients tested and in fibroblasts
from one patient. Immunoblot analysis using EBV-transformed or PHA-stimulated
lymphoblasts represents a useful approach for laboratory diagnosis for A-T. The
latter is especially preferable since it takes only 3 days to obtain sufficient
cells for analysis.
PMID- 10780799
TI - Schnitzler syndrome: a case study.
AB - Schnitzler syndrome is a clinical entity of unknown etiopathogenesis and is an
unusual cause of chronic urticaria. It is characterized by the presentation of a
monoclonal band, especially IgM, as well as fever, asthenia and arthralgia. We
present the case of a 48-year-old man with 5 years of recurrent urticarial
lesions, slight itching, as well as lip, face and occasional pharyngeal edema.
The patient had also suffered from fever and right hip and left knee arthralgia.
The protein electrophoresis and the immunoelectrophoresis presented an IgG band
and a slight lambda band, which is suggestive of a monoclonal gammopathy. The
bone marrow examination showed a slight increase in the lymphoplasmatic cells.
The marrow biopsy was negative. In order to rule out tumorous, infectious and
rheumatic processes as well as collagen diseases, other complementary
examinations were performed with negative results. The diagnosis of Schnitzler
syndrome as a cause of chronic urticaria requires a thorough study in order to
rule out other systemic processes provoking the same symptoms.
PMID- 10780797
TI - Latex allergy among operating room personnel in Turkey.
AB - This study was performed to evaluate the prevalence of latex allergy among health
care workers in Turkey, as well as to compare the medical histories with the skin
test results and investigate the risk factors. Using a 1/100 weight/volume
commercial skin prick test (SPT), we investigated latex sensitization in 206
health care workers who regularly use latex products. One hundred atopic and 100
nonatopic patients without occupational latex exposure were also examined as
control groups. Latex SPTs were positive in 10 health care workers (9.22%),
whereas none of the control patients was found to have positive SPT to latex.
Health care workers were divided into two groups based on the latex SPT results.
There was no significant difference between the latex SPT-positive and -negative
health care worker groups according to age, sex and total exposure time to latex.
In the latex SPT positive group, daily exposure time and daily glove use were
significantly higher (p <0.05). The symptoms related to latex products were
limited to hands and itching was present in all, however, erythema was found in
68.4%, and contact urticaria in 52.6% in the latex SPT positive group. These
symptoms in the latex SPT negative health care group were 21.4%, 14.4%, and 1.6%,
respectively (p <0.0001). History of allergic rhinitis, bronchial asthma and
conjunctivitis were also higher in the SPT-positive group (p <0.05).
Additionally, we found sensitivity to house dust mites and/or grass pollens in
seven cases of latex allergy. Patch tests with rubber additives were positive in
five out of 42 medical care workers. Two surgeons were found to have both type-I
hypersensitivity to latex and type-IV hypersensitivity to rubber additives. Our
results suggest that the frequency of latex allergy is higher in the atopic
health care workers with a high exposure to latex, and that SPT is a sensitive,
safe, cheap and easy method of testing the diagnosis of latex hypersensitivity.
PMID- 10780800
TI - Anaphylaxis to pine nuts and immunological cross-reactivity with pine pollen
proteins.
AB - Despite the wide use of pine nuts, the fruit of Pinus pinea, only a few reports
of allergic reactions to them have been published. We present herein a case of
food allergy to pine nuts in a patient who showed no clinical symptoms to pine
pollen despite the presence in her serum of specific IgE antibodies. In order to
verify whether the reaction against pine nuts was IgE mediated, specific IgE
against pine nuts and pollen were evaluated by skin-prick test, prick by prick
and RAST. Immunoblotting and immunoblotting-inhibition were used to evaluate the
allergenic components of both extracts and their cross-reactivity. Prick by prick
with fresh pine nuts and RAST with pine nut and pine pollen extracts showed that
the patient had high levels of specific IgE against both extracts. Immunoblotting
experiments showed the presence in serum of IgE antibodies against several
components in pine nuts and pollen. Immunoblotting-inhibition experiments
demonstrated the presence of some cross-reacting components. These data confirm
the existence of food allergy induced by pine nuts. This sensitization to pine
nuts developed with no symptoms of pine pollinosis. Development of pollinosis may
require a longer time of exposure to allergens. Based on the cross-reactivity
between pine nut and pine pollen extracts, cosensitization to these two allergens
could be possible.
PMID- 10780801
TI - Erythropoietic protoporphyria with antinuclear antibody positivity: avoiding
misdiagnosis of systemic lupus erythematosus.
AB - A young eunuchoid man was referred to our hospital with suspected erythropoietic
protoporphyria. Serum antinuclear antibody (ANA) was found to be positive
immediately after the porphyria attack and disappeared 30 days later. Many
authors have mentioned the coexistence of systemic lupus erythematosus (SLE) and
porphyria. As these two disorders have similar clinical features, the clinician
must be alert and use strict diagnostic criteria in determining the presence of
SLE with porphyria. In the past, elevation of ANA was reported in the cases of
acute intermittent porphyria. However, there have been no reports in the cases of
erythropoietic protoporphyria. In addition, the patient was found to have
hypogonadotropic hypogonadism consistent with Kallmann's syndrome. To our
knowledge, this report is the first case showing the coexistence of Kallmann's
syndrome and erythropoietic protoporphyria. As yet, the clinical importance of
this association remains unknown.
PMID- 10780802
TI - The effects of morphine on responding under variable-interval schedules: rate
related effects, behavioral mechanisms and Herrnstein's hyperbola.
AB - The study was designed to integrate rate-related principles and Herrnstein's
hyperbolic matching equation (1970) as they apply to drug effects. It was also
designed to assess the validity of an interpretation of Herrnstein's equation
used to account for the behavioral mechanisms of drug action. Eight rats were
trained to press a lever under a range of variable-interval (VI) schedules of
reinforcement using sucrose solution (0.1 M) as a reinforcer. After 90 baseline
sessions the effect of morphine sulfate, 3, 6, 12 and 17 mg/kg, on responding was
tested. Response rates were suppressed in a dose-dependent manner after morphine
administration. Herrnstein's equation, which states that responding is a function
of relative reinforcement rate, provided a good description of the relationship
between responding and reinforcement under most conditions. Therefore, the
traditional variable used to predict the drug effect in rate-dependency
functions, baseline response rate, was compared to a new variable, baseline
relative reinforcement rate. Relative reinforcement rate performed as well as
response rate in predicting the drug effect. In order to test if Herrnstein's
hyperbola can identify the behavioral mechanisms of the action of morphine, the
concentration of the sucrose solution was increased (0.32 M). The y-asymptote of
Herrnstein's equation, k, increased as sucrose concentration increased. This
calls into question one common interpretation of Herrnstein's equation used to
identify the behavioral mechanisms of drug action.
PMID- 10780803
TI - Effects of lithium dose (UCS) on the acquisition and extinction of a
discriminated morphine aversion: tests with morphine and delta9-THC.
AB - The effects of varying the lithium dose (unconditioned stimulus [UCS]; LiCl range
30-180 mg/kg) on the acquisition and extinction of stimulus control by 5.6 mg/kg
of morphine in a discriminated taste aversion (DTA) procedure were examined in
rats. In addition, pharmacological specificity was examined by substituting (-)
delta-9-tetrahydrocannabinol (delta9-THC) for morphine during a test phase
intervening between acquisition and extinction. DTA acquisition was more rapid at
higher LiCl doses. The lowest dose of LiCl, 30 mg/kg, did not robustly maintain a
DTA. Two groups treated with 60 mg/kg LiCl, differing only in the type of
drinking nozzle used (ball-bearing vs standard non-ball-bearing), behaved
similarly. Suppression of drinking was related to the morphine dose, in an
orderly manner (dose range 0.3-10 mg/kg), in rats for which morphine was followed
by LiCl. No significant decline in drinking occurred for rats for which morphine
was followed by saline, except perhaps at the 10 mg/kg test dose of morphine. The
control of drinking was pharmacologically specific; both experimental and control
animals were equally affected in tests with delta9-THC (0.3-10 mg/kg). Low doses
of delta9-THC increased water consumption; this did not occur with morphine.
During extinction the reinstitution of drinking was similar across groups that
had been effectively conditioned, i.e. there was no apparent effect of lithium
dose on extinction. After extinction, a much attenuated reaction occurred to
morphine in tests with 3 and 10 mg/kg. These doses of morphine had significantly
suppressed drinking before the extinction phase. Collectively, these data add to
the formal similarities between sensory and drug discriminative stimuli.
PMID- 10780804
TI - Behavioural effects of glutamate receptor agonists in morphine-dependent rats.
AB - Glutamate receptors are implicated in the development and expression of drug
dependence. Substantial experimental evidence suggests that antagonists acting at
the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors attenuate the
severity of opioid withdrawal. However, it is less clear whether opioid
withdrawal can be potentiated by agonists of glutamate receptors. The present
study evaluated the behavioural effects of various agonists of glutamate
receptors, as well as a nitric oxide (NO) donor, in morphine-dependent rats
trained to discriminate 0.1 mg/kg of naloxone from saline. None of the following
drugs produced appreciable levels of naloxone-like responding (substitution
tests) or potentiated the discriminative stimulus effects of naloxone: NMDA (3-56
mg/kg), glycine (100-1000 mg/kg), glutamate (1000-3000 mg/kg), kainate (0.3-3
mg/kg), isosorbide dinitrate (30-300 mg/kg). Nevertheless, expression of some
morphine withdrawal-like somatic and behavioural signs ('wet-dog'-like shaking,
scream on touch, ptosis, tremor, chewing, weight loss) was facilitated by NMDA,
glycine, and isosorbide dinitrate. These results suggest that, compared to
somatic symptoms, subjective effects of opioid withdrawal (as reflected by
discriminative stimulus effects) are not mimicked by direct activation of
glutamate receptors.
PMID- 10780805
TI - Sensitization to apomorphine in pigeons is due to conditioning, subject to
generalization but resistant to extinction.
AB - Apomorphine (Apo) administration induces a persistent bout of pecking in pigeons
and other birds. Repeated injections of Apo in pigeons lead to sensitization,
i.e. the pecking response to a particular dose increases up to a dose-dependent
asymptotic level. It is also known that Apo-induced pecking can be classically
conditioned to the cage environment where the animals experience the effect of
the drug. Here we address the question of whether, and to what extent, the
sensitization effect arises as a consequence of a conditioning or of a
pharmacological process. An extinction experiment demonstrated that an extinction
procedure supposed to be effective in inhibiting the conditioned pecking response
was not effective in suppressing the sensitization to Apo, thus casting
provisional doubt on the conditioning hypothesis. However, a conditioning
experiment demonstrated that the sensitization effect undoubtedly involved an
important component of conditioning to an experimental cage environment, but also
suggested that there was an additional component possibly not due to learning. A
generalization experiment, however, showed that this second component was very
probably due to a stimulus generalization effect deriving from conditioning to
the home cage, suggesting that learning can account for most, if not all, of the
increase in Apo-induced pecking and that an exclusively pharmacological
sensitization process plays, at best, a minor role. The apparent contrast between
the results of the first experiment, indicating that the sensitization is not
affected by inhibitory conditioning, and the results of the last two experiments,
suggesting that the sensitization is due to excitatory conditioning, can be
resolved by assuming that Apo induces a drug-state-dependent conditioning. These
results are related to findings and arguments concerning the sensitization to
psychostimulant drugs in mammals.
PMID- 10780806
TI - Prenatal protein restriction increases sensitization to cocaine-induced
stereotypy.
AB - The present study characterized the total amount of stereotyped behavior
following acute and repeated administration of cocaine in male and female
prenatally protein malnourished rats. Adult offspring of female Sprague-Dawley
rats fed either a low (6% casein) or adequate (25% casein) protein diet 5 weeks
prior to mating and throughout their pregnancy were studied. Once every 3 days
(for a total of six injections), half the rats from each nutritional treatment
group (repeated exposure) were injected with cocaine (30 mg/kg, i.p.) and their
total amount of stereotypy (rearing, forepaw treading, compulsive sniffing and
head bobbing) monitored. The remaining rats received five saline injections
followed by a cocaine injection on the last injection day (acute exposure group)
and their behavioral response was also measured. Despite being slightly less
sensitive to cocaine following their first injection, by the sixth injection,
prenatally protein malnourished animals in the repeated-exposure group exhibited
significantly greater sensitization to the psychomotor stimulant effects of
cocaine than well-nourished controls. In the acute exposure groups, however,
prenatally malnourished males, but not females, exhibited significantly more
stereotypy than well-nourished subjects following a single cocaine injection.
These findings have implications for characterizing addiction potential in the
previously malnourished rats, as well as providing additional information
regarding factors which can influence sensitization.
PMID- 10780807
TI - Effects of training history on drug discrimination under concurrent fixed
interval schedules.
AB - Pigeons with previous pentobarbital-discrimination training under concurrent VI
60 VI 240 and concurrent FI 60 FI 240 schedules were trained to respond under a
concurrent FI 15 FI 285 schedule of food presentation. A second group of pigeons
was trained only under the concurrent FI 15 FI 285 schedule. When responding
stabilized during training sessions, both groups made 75-85% of their responses
on the key where responses produced the reinforcer under the FI 15 component of
the concurrent schedule. When the schedule was changed to concurrent FI 150 FI
150, the presence or absence of pentobarbital continued to control responding for
the group with the extensive training history, but responding by the other group
was rapidly controlled by the new reinforcement schedule. These data suggest that
the behavioral history of the subject can be an important determinant of stimulus
control by drugs. Despite these effects of training history on drug
discrimination responding, during the first minute of the session, the dose
response curves for pentobarbital, chlordiazepoxide, ethanol, phencyclidine and
methamphetamine were similar in both groups of pigeons.
PMID- 10780808
TI - Naltrexone does not attenuate the acute behavioral effects of ethanol or
pentobarbital in humans.
AB - The aim of the present study was to determine whether naltrexone, an opioid
antagonist, attenuates the acute subject-rated, performance-impairing and
physiological effects of ethanol or pentobarbital. To accomplish this aim, two
separate experiments were conducted. In Experiment 1, eight volunteers (one
female, seven males) received ethanol (0, 0.5 and 1.0 g/kg) alone and in
combination with naltrexone (0, 50 and 100 mg). In Experiment 2, eight different
volunteers (five females, three males) received pentobarbital (0, 150 and 300
mg), alone and in combination with naltrexone (0, 50 and 100 mg). Subjects
received one of the nine possible drug-naltrexone combinations under double-blind
conditions during each of nine experimental sessions. Order of drug
administration was mixed, and at least 48 h separated all sessions. In Experiment
1, subjects orally ingested ethanol 1 h after naltrexone. In Experiment 2,
subjects ingested naltrexone 1 h after pentobarbital. The timing of drug
administration was arranged so that the peak behavioral effects of ethanol or
pentobarbital occurred so that across peak plasma levels of naltrexone. Drug
effects were assessed before drug administration and periodically afterwards for
5 h using a battery of subject-rated drug-effect questionnaires and performance
measures previously shown to be sensitive to the acute effects of ethanol.
Ethanol and pentobarbital produced prototypical subject-rated drug effects (e.g.
increased subject ratings of Drunk, Drug Liking, Elated and Good Effects) and
impaired performance. Naltrexone did not produce significant effects on these
measures. In other words, naltrexone did not attenuate the acute subject-rated
and performance-impairing effects of ethanol or pentobarbital. The mechanism by
which naltrexone exerts its clinical effect in the treatment of alcohol
abuse/dependence remains unclear.
PMID- 10780809
TI - Evaluation of limited and unlimited food intake during withdrawal in triazolam
dependent baboons.
AB - Chronic administration of benzodiazepine (BZ) agonists in baboons typically
increases food intake, in a dose-dependent manner, during drug administration and
suppresses food intake after termination of drug dosing. To determine if
suppressed food intake after termination of chronic BZ administration (i.e.
withdrawal) was related to increased food consumption during drug administration,
the effects of chronic triazolam (1.0 mg/kg/day, intragastrically, for 30-34
days) and subsequent triazolam withdrawal on food intake was studied under two
conditions in each of four baboons: (1) when the number of pellets was unlimited;
and (2) when the number of pellets was limited so that pellet intake could not
increase above the mean number of pellets per day obtained during a preceding
vehicle condition. Pellets were available during daily 20-h sessions under a
fixed-ratio 10 schedule of reinforcement. All baboons completed both pellet
conditions, and the order of exposure was counterbalanced across subjects. During
the unlimited pellet condition, pellets per day were increased during triazolam
administration and then were suppressed in a time-limited manner when triazolam
was discontinued in all four baboons. When pellet intake was limited during
triazolam administration, pellet intake after triazolam discontinuation was
suppressed in three of four baboons, and the magnitude and duration of
suppression was generally less than during the unlimited pellet condition. Other
behavioral signs of withdrawal (e.g., tremor/jerk, vomit/retch) were observed in
all four baboons under both pellet conditions. These data suggest that the
hyperphagic effects of triazolam appear to contribute to the subsequent
suppression of food intake during triazolam withdrawal. However, these
hyperphagic effects do not account for the entire phenomenon of suppressed food
intake during BZ withdrawal.
PMID- 10780810
TI - Spatial learning deficit after NMDA receptor blockade and state-dependency.
AB - The non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine
(MK-801) (0.08 and 0.12 mg/kg, i.p.) was used to examine whether spatial memory
is learned state-dependently. Rats pre-treated with drug or saline were trained
for 9 days in an eight-arm radial maze, in which four arms were baited. On the
tenth day MK-801-treated rats were injected with saline and one group of saline
treated rats were injected with MK-801 (0.12 mg/kg) while another received
saline. Performance of spatial memory was analysed for state-dependency. Neither
rats treated with 0.08 mg/kg nor 0.12 mg/kg of MK-801 for 9 days were impaired in
recall of spatial memory under saline. However, MK-801 impaired acquisition of
spatial memory, with deficits in working memory and less marked deficits in
reference memory. Motor activity (speed) was enhanced at both doses. Thus,
learning under NMDA receptor blockade does not necessarily produce a condition
that impedes the expression of the learning task under a different condition.
PMID- 10780812
TI - The effects of feeding and housing on the behaviour of the laboratory rabbit.
AB - The effects of housing, feeding time and diet composition on the behaviour of the
laboratory rabbit were examined. The animals were caged individually in single or
double metal cages with perforated metal floors, metal walls, and bars in the
front, or kept as a group in floor pens. The light/dark cycle was 12/12 h with
light from 04:00 to 16:00 h and 30 min twilight. One experiment compared feeding
equal energy levels of a high energy diet (10.1 MJ/kg) and with a low energy diet
(7.0 MJ/kg) at 08:00 h. The second experiment compared feeding the high energy
diet at 08:00 h and at 14:00 h. In both studies the behaviour of the rabbits was
recorded between 08:00 and 14:00 h and between 16:00 and 22:00 h. Feeding the
animals at 14:00 h reduced abnormal behaviour during the dark period compared to
feeding at 08:00 h, whereas no difference in behaviour could be detected between
feeding a high-energy and a low-energy diet at 08:00 h. Animals in floor pens
generally showed less abnormal behaviour than caged animals. The results indicate
that the welfare for caged rabbits can be improved by feeding the animals in the
afternoon rather than in the morning.
PMID- 10780811
TI - SR 141716A, a CB1 cannabinoid receptor antagonist, potentiates the locomotor
stimulant effects of amphetamine and apomorphine.
AB - The intraperitoneal (i.p.) injection of apomorphine or d-amphetamine
significantly increased locomotor activity in Sprague-Dawley rats. Prior
administration of the cannabinoid receptor antagonist, SR 141716A, significantly
enhanced the stimulant effect of both d-amphetamine and apomorphine in a dose
dependent manner. Administration of SR 141716A alone had no effect on locomotor
activity. These data indicate that endogenous cannabinoids exert an inhibitory
action on the increase in locomotor activity produced by amphetamine and
apomorphine.
PMID- 10780813
TI - Aspen wood-wool is preferred as a resting place, but does not affect intracage
fighting of male BALB/c and C57BL/6J mice.
AB - Aspen wood-wool, provided as nesting material, was evaluated as a possible
improvement of cage environment for 10-14-week-old inbred male mice maintained in
groups of six (BALB/c n = 72 and C57BL/6J n = 36). The daily behaviour of mice
was video recorded and their body weight, food consumption, weights of some
organs and serum corticosterone concentrations were measured. Aggressive
interactions between cage mates and against a strange intruder as well as the
number of wounds on the back of the animals was monitored in order to evaluate
the effect of nesting material on intermale aggression. Nesting material did not
affect the daily active/passive behaviour patterns of mice, although animals
clearly preferred it as a resting place. BALB/c mice given nesting material
showed less weight gain and smaller brown adipose tissue weights than animals
without nesting material. The other characteristics measured were not affected by
the presence of nesting material in either strain. The presence of nesting
material had no effect on fighting in cages. C57BL/6J mice were more aggressive
than BALB/c mice according to the number of wounded animals in a cage. Wounded
BALB/c mice had enlarged spleens and decreased epididymal adipose tissue weights.
In conclusion, the nesting material used in this study did not adversely affect
the animals. On the other hand, the material was clearly preferred to
conventional bedding as a resting place. These findings suggest that nesting
material may improve the cage environment of laboratory mice. Furthermore, there
was an indication of strain differences in aggressive behaviour. It could be
suggested that C57BL/6J mice are less tolerant towards intruders and housing six
mice per cage is not suitable for this strain.
PMID- 10780814
TI - Nesting material and number of females per cage: effects on mouse productivity in
BALB/c, C57BL/6J, DBA/2 and NIH/S mice.
AB - Two different materials-aspen wood-wool and paper towel-were compared as nesting
material for three inbred mouse strains (BALB/c, C57BL/6J and DBA/2) housed in
barrier conditions. In addition, the effect of varying the number of females per
cage (one to three per cage) of these three strains and with NIH/S outbred mouse
stock was studied. The number of litters, litter size and neonatal mortality were
determined, as well as age, sex and weight of weanlings. The type of nesting
material did not affect the characteristics monitored. In all strains, the number
of weanlings per female was greatest in singly-housed females. In terms of the
number of weanlings per cage, two females per cage gave the best result. In DBA/2
mice, neonatal mortality increased when several females were caged together.
PMID- 10780815
TI - Non-surgical catheterization of the jugular vein in young pigs.
AB - Current methods utilized for serial blood collection in the young pig are limited
due to the stress and/or discomfort to which the pig is exposed. Thus, we have
developed a non-surgical, minimally invasive cannulation technique which allows
jugular vein catheter placement in the young pig without causing extended
discomfort or stress. The procedure described is rapid (approximately 8 min/pig)
and relatively simple, requiring only minimal anaesthesia for immobilization of
the pig during the procedure. Routinely, 2-week-old piglets are standing in their
pens within 15-20 min from initiation of the procedure. Piglets recover rapidly
from the procedure and display no clinical indications of pain or discomfort.
Serum concentrations of cortisol, a standard indicator of stress and/or
discomfort, are asymptomatic within 2 h of completing the procedure (k = 26.14+/
3.03 ng/ml). Stress is limited to the initial immobilization of the piglets. With
this technique of cannulation, we routinely maintain catheter patency for 2 days,
and often for as long as 5 days.
PMID- 10780816
TI - A new porcine model of reperfusion injury after lung transplantation.
AB - Rodent models have been described to investigate lung preservation and
reperfusion injury but have significant disadvantages. In large animals single
lung transplant studies are probably optimal but problems remain over the ability
to rigorously separate the lungs for assessment while promoting medium to long
term animal survival for meaningful investigation. Our aim was to develop a novel
and refined large animal model to assess reperfusion injury in the transplanted
lung, overcoming the difficulties associated with existing models. Specifically,
small animal models of lung transplantation usually have short perfusion times
(often one hour) and include extracorporeal circuits while larger animal models
often require the contralateral lung to be excluded after transplantation-an
unphysiological situation under which to evaluate the graft. A porcine model of
left lung allotransplantation was developed in which native and donor lungs are
individually ventilated. Sampling catheters placed within the graft lung allowed
specimen withdrawal without mixing of blood from the contralateral lung after
reimplantation. The model permits a variety of clinical scenarios to be simulated
with the native lung supporting the animal irrespective of function in the graft.
This model has been used in over 60 transplant procedures with a postoperative
survival time of 12 h being readily achieved. The mean operating time was 2.6 h.
The mortality rate is 4% in our series. We have found the model to be reliable,
reproducible and flexible. We propose this model as an adaptable investigation
for evaluating lung reperfusion injury and preservation.
PMID- 10780817
TI - Bacterial counts in canine duodenal fluid after exposure to saline, sodium
bicarbonate and hypertonic dextrose solutions used to maintain patency of
chronically implanted catheters.
AB - Flushing of intestinal vascular access ports (VAPs) is commonly performed to
prevent the problems of blockage and infection, and in this study four different
flushing solutions were compared. The growth of bacteria from canine duodenal
contents was compared in: 0.9% saline, 50% dextrose, 8.4% sodium bicarbonate
(NaHCO3) and 0.01 M phosphate buffered saline (PBS). Duodenal contents from three
laboratory beagles were serially diluted in these four solutions, spread plated
onto agar at 24 h periods for 7 days and bacterial counts were performed.
Immediately after the duodenal juices were added, no significant differences
could be seen in bacterial counts with any of the solutions. Over the 7 day
period, bacterial numbers greatly increased in saline and phosphate buffered
saline, but greatly decreased in dextrose and sodium bicarbonate solutions.
Dextrose and sodium bicarbonate appeared to be the most promising flushing
solutions tested to minimize infections of associated intestinal VAPs.
PMID- 10780818
TI - The telomerase activities in several organs and strains of rats with ageing.
AB - Telomerase activity is known to be implicated both in cell immortalization and
carcinogenesis. Telomerase activity has not been detected in most human somatic
tissues. However, we previously confirmed that the activity is present both in
methylazoxymethanol acetate-induced rat colonic adenocarcinoma and non-treated
colonic mucosa, presumably indicating the tissue-specific activity of the enzyme
in rats. To determine the standard activity of rat telomerase in various organs
in relation to differences in sex, age and strain, we examined the activity by
using the telomeric repeat amplification protocol (TRAP) assay. The testis,
liver, and colon mucosa showed the activity. The brain had very low or negative
activity in 5-week-old male rats of the F344, SD, Wistar, Donryu or ACI strains.
Age (5-week-old and 9-month-old) or sex difference for the activity was not
apparent in rats of these strains. In general, telomerase activity in the fetal
brain, liver and kidney was stronger than in the adult organ. The telomerase
activity of each organ was different from that of human. This difference may
indicate that the rat has a specific mechanism for maintaining the telomeric
repeats of the chromosome even in somatic tissues. The basic information
resulting from this study may be useful for the study of the role of telomerase
in tumorigenesis in animal experiment models.
PMID- 10780819
TI - Is carbon dioxide (CO2) a useful short acting anaesthetic for small laboratory
animals?
AB - The anaesthetic effect of carbon dioxide (CO2) was investigated under
predetermined exposure times in rats, mice and guinea pigs with admixture of 20%
of oxygen (O2), and with 20% of ambient air in rats. In rats first symptoms
(median) were detectable between 7 and 9.5 s, the induction time (median) varied
between 16 and 20.5 s and the surgical tolerance (median) was 40 s (after 60 s of
exposure) and 53.5 s (after 120 s of exposure) to 80% CO2/20% O2. When O2 was
replaced by ambient air, a surgical tolerance of 53.5 s (after 60 s of exposure)
and 77 s (after 120 s of exposure) was measured. In mice the induction time to
80% CO2/20% O2 was 10 s and the surgical tolerance 19.5 s (after 120 s of
exposure). Guinea pigs showed an induction period of 20 s and a surgical
tolerance of 50 s (after 30 s of exposure) to 80% CO2/O2. Recovery was short and
smooth in all species. This method of general anaesthesia seems to be suitable
for short and painful interventions, mainly in rats, but also in guinea pigs.
PMID- 10780820
TI - Short duration anaesthesia with medetomidine and ketamine in cynomolgus monkeys.
AB - Cynomolgus monkeys were anaesthetized with either intramuscular ketamine (10
mg/kg or intramuscular ketamine 2 mg/kg and medetomidine 50 microg/kg. Various
physiological measurements were made once the animals were safe to handle and
again 10 min later. Cardiovascular and respiratory function were well maintained
with both regimens but the heart rate was lower and arterial-alveolar carbon
dioxide gradient was higher in the animals that received medetomidine. In those
animals that received medetomidine, atipamezole was given to reverse the
medetomidine but there was no difference in recovery times between the two
regimens. Anaesthesia was not entirely reliable with medetomidine/ketamine and we
recommend caution when using this mixture.
PMID- 10780821
TI - Use of oral buprenorphine ('buprenorphine jello') for postoperative analgesia in
rats--a clinical trial.
AB - Buprenorphine (0.1, 0.2, 0.3 or 0.4 mg/kg) in a flavoured gelatin base was
administered preoperatively to rats undergoing a flank laparotomy. A control
group of animals underwent surgery and received only flavoured gelatin. Body
weight loss was significantly greater in the group which received no analgesia
than in any of the analgesic-treated groups (P < 0.01). Food consumption was
reduced significantly in all groups except in those animals which received 0.3
mg/kg buprenorphine. Water consumption was significantly reduced in the control
(no analgesia) group (P < 0.001), but was not significantly depressed in the
analgesic-treated groups (P > 0.05). Between-group comparisons did not show any
significant difference between the different dose rates of analgesia used on
either the change in body weight or the reduction in food or water consumption.
The results of this study support the use of buprenorphine jelly for post
surgical analgesia in rats. This route of delivery is easy to use, and causes a
minimum of stress to the rats.
PMID- 10780822
TI - The VX2 carcinoma in the rabbit auricle as an experimental model for intra
arterial embolization of head and neck squamous cell carcinoma with dextran
microspheres.
AB - A head and neck cancer model is developed using the VX2 carcinoma cell line
injected s.c. in both ears of New Zealand White (NZW) rabbits. The study is
focused on the effects of intraarterial embolization of the carcinomas with a new
type of dextran hydrogel microspheres. During the phase of exponential growth the
tumour-surface doubling-time was 7.1+/-2.0 days. Standard deviation in growth of
the tumours was significantly larger between separate animals than between
tumours growing in the left and right auricle of each individual animal (2.0
versus 0.65 days). A fresh cell suspension containing at least 10 x 10(6) vital
tumour cells was necessary to yield a tumour-take of 85%. The caudal auricular
artery perfuses the caudal half of the external ear and is very suitable for
macroscopic cannulation. Histological evaluation shows, that the use of dextran
hydrogel microspheres of at least 25 microm in combination with ligation of non
tumour perfusing branches of the central auricular artery yields diffuse
embolization of the VX2 carcinoma. This tumour model can be of use in further
studies to optimize particle size and dosage for embolization as well as to
evaluate the effect of different anti-neoplastic drugs, slowly released by
controlled degradation of dextran microspheres.
PMID- 10780823
TI - Adaptation of corticosterone-but not beta-endorphin-secretion to repeated blood
sampling in rats.
AB - Effects of short-term repeated blood sampling on the secretion of corticosterone
(CORT) and beta-endorphin (beta-END) were evaluated in male Wistar rats. Blood
was drawn from the tail vein of conscious rats four times within 2 h both at the
peak and trough period of the diurnal corticosterone secretion cycle. All rats
were well accustomed to the procedure. The main findings were: (1) At both
sampling intervals, CORT increased significantly in response to the first
sampling and declined to baseline values in successive samples. (2) beta-END also
increased significantly in response to the first sampling but remained elevated
in successive samples. (3) Intensities of initial CORT and beta-END responses
correlated positively with each other and with the baseline beta-END values.
Feedback inhibition of CORT secretion with sustained elevation of beta-END titres
suggests a moderate stress intensity of the repeated blood sampling procedures.
In general, due to lack of short-term feedback inhibition, beta-END seems to
reflect the effects of repeated administration of moderate intense stressors more
closely than CORT.
PMID- 10780824
TI - Tribromoethanol (Avertin) as an anaesthetic in mice.
PMID- 10780825
TI - Chronobiotic effects of gepirone, a potential antidepressant with 5HT1A receptor
partial agonist properties.
AB - Abnormal timing in the circadian system is reported in endogenous depression.
Gepirone, a 5HT1A receptor partial agonist, has anxiolytic and antidepressant
properties. We determined whether gepirone was able to modify the functioning of
the circadian system. Single i.p. injections of gepirone in hamsters induced
phase-advances in the circadian activity rhythm when administered during the
subjective day, but had no effect when given during the subjective night. Single
i.p. gepirone injections also blocked the phase-shifting effects of a light
pulse, at a time when gepirone by itself had no effect on the activity rhythm.
Chronic gepirone treatment in hamsters kept under a 14/10 light-dark cycle
induced a phase-advance in the activity rhythm, modifying the phase-relationship
between this rhythm and the light-dark cycle. After transfer to constant
darkness, gepirone-treated hamsters showed a shortened free-running period of
activity, compared to controls. Both acute and chronic gepirone treatment thus
have major effects on the circadian rhythm of locomotor activity in rodents. In
view of the hypothesized role for disturbed circadian rhythms in the
pathophysiology of depression, and the use of 5HT-related drugs for its
treatment, the results provide further support for the possibility that some of
the therapeutic effects of these compounds may be due to their effects on
temporal organization.
PMID- 10780826
TI - Effects of GABA-transporter (GAT) inhibitors on rat behaviour in open-field and
elevated plus-maze.
AB - The behavioural consequences of inhibition of gamma-aminobutyric acid (GABA)
uptake were studied. Two GABA uptake inhibitors, tiagabine and SKF 89976-A, were
administered to rats, and behaviour was analysed 30 min later in a standard open
field, an enriched open field, and an elevated plus-maze. Eight groups of animals
received either saline (0.9%), tiagabine, or SKF 89976-A. At a dose of 18.5
mg/kg, tiagabine, an established antiseizure drug, impaired motor coordination,
enhanced exploratory activity and reduced anxiety related behaviour. SKF 89976-A
exhibited minimal effects over the dose range tested. These results indicate that
inhibition of GABA uptake might be a pharmacological strategy to treat not only
epilepsy, but also anxiety disorders.
PMID- 10780827
TI - Isolation rearing-induced disruption of prepulse inhibition: further evidence for
fragility of the response.
AB - The present study investigated isolation-induced disruptions of prepulse
inhibition (PPI), and effects on locomotor activity as a function of home caging
condition (sawdust vs grid-floor) in the Wistar rat. Isolates reared in grid
floor cages did not show a disruption of PPI. However, when isolates were reared
in sawdust cages, a PPI deficit was evident. In an open field environment,
isolates demonstrated significantly increased spontaneous locomotor activity
compared to their group-housed counterparts, irrespective of the caging condition
employed. Grouped animals reared in grid-floor cages, however, showed reduced
activity compared to grouped animals reared in sawdust cages. Although d
amphetamine treatment appeared to enhance locomotor activity selectively in
isolates, particularly in those reared in grid-floor cages, this result could be
explained by the existing pre-drug activity levels. With respect to PPI, not only
were isolation-induced deficits in the Wistar rat difficult to detect in a
variable prepulse intensity PPI procedure, but when apparent, the deficits were
of a fragile nature. The findings suggest that caging condition may be a critical
methodological factor in experiments investigating isolation-induced PPI
deficits. Indeed, our results may indicate that rearing animals in grid-floor
cages represents a form of chronic mild stress, which can interfere with normal
sensorimotor gating mechanisms, in addition to other behaviours.
PMID- 10780828
TI - Alcohol and the appetizer effect.
AB - In order to evaluate the effects of alcohol on appetite, 12 unrestrained and 10
restrained men ate lunch 20 min after consuming preloads consisting of water, an
alcoholic fruit juice (alcohol) and a non-alcoholic fruit juice (juice). The
unrestrained men ate significantly less after the juice preload, and ate most
after alcohol. Intake was not altered significantly in the restrained men.
However, both the alcohol and juice preloads reduced rated hunger and increased
fullness, relative to the water control, in both restrained and unrestrained men.
When the relationship between rated appetite and intake within the test meal was
modelled mathematically, it was found that hunger increased more during the
initial stages of the test meal in the unrestrained men who had consumed alcohol
than in any other condition. No such effects were seen in the restrained
subjects. Overall, these results suggest that alcohol has a complex action on
appetite, which includes some form of appetite stimulation, and this may explain
the excess energy intake reported previously in moderate alcohol consumers.
PMID- 10780829
TI - The validity of the pretreated, unilaterally MPTP-treated monkeys as a model of
Parkinson's disease: a detailed behavioural analysis of the therapeutic and
undesired effects of the D2 agonist quinpirole and the D1 agonist SKF 81297.
AB - The goal of this study was to evaluate the validity of the pretreated,
unilaterally MPTP-treated monkey as an animal model of Parkinson's disease (PD).
For that purpose, a detailed ethogram was developed and assessed in four male
rhesus monkeys that had received MPTP (2.5 mg) in the carotid artery
contralateral to the dominant limb. Subsequently, the behavioural effects of the
dopamine D2 agonist quinpirole and the dopamine D1 agonist SKF 81297 were
studied. The ethogram was found to allow a clear-cut and objective separation of
drug-induced behaviours into therapeutic and undesired effects in the MPTP
treated monkeys. Saline-treated monkeys predominantly displayed ipsilateral goal
directed fore-limb movements, and distinct types of ipsilaterally directed
rotations. Although quinpirole and SKF 81297 increased motor behaviours, such as
body displacement, contralateral fore-limb movements and contralateral rotational
behaviours, assessment of the new detailed ethogram revealed that this increase
was completely due to the activation of abnormal, non-goal-directed behaviours,
such as dyskinetic fore-limb movements, pivoting and shuffling. Moreover, the new
ethogram made clear that the drug treatments induced not only dyskinesia and
dystonia, but also epileptoid behaviour, which was confirmed by EEG analysis. In
summary, the detailed behavioural analysis showed that this model does not
adequately predict the clinical effects of the D2 agonist. It is concluded that
the pretreated, unilaterally MPTP-treated monkey is not a valid model to predict
the therapeutic and undesired effects of dopaminergic drugs in humans.
PMID- 10780830
TI - The predictive validity of the drug-naive bilaterally MPTP-treated monkey as a
model of Parkinson's disease: effects of L-DOPA and the D1 agonist SKF 82958.
AB - The aim of this study was twofold: (1) to study the predictive validity of the
drug-naive, bilaterally MPTP-treated monkey as an animal model of Parkinson's
disease (PD), and (2) to investigate the therapeutic and undesired effects of the
D1 agonist SKF 82958 as compared to L-DOPA treatment, in drug-naive and L-DOPA
pretreated monkeys. A detailed ethogram was used, allowing the separation of
therapeutic and undesired effects. Eight weeks after bilateral intracarotid MPTP
administration, SKF 82958 (1 mg/kg, n = 4, SKF 82958, naive group) or methyl-L
DOPA + carbi-dopa (10 + 2.5 mg/kg, n = 4, L-DOPA group) was administered
intramuscularly for 22 days. After a drug-free period of eight weeks, the L-DOPA
group was treated with SKF 82958 for 22 days (SKF 82959, 1 mg/kg, n=4,
pretreated). All drug treatments increased the parameters used classically to
evaluate dopaminergic drugs, namely body displacement, dyskinesia and dystonia.
However, the new detailed analysis revealed that L-DOPA, but not SKF 82958, had
therapeutic effects, reflected by an increase in goal-directed fore-limb use. SKF
82958, but not L-DOPA, induced additional undesired effects; including epileptoid
behaviours in both drug-naive and drug-pretreated monkeys. In one L-DOPA
unresponsive monkey, SKF 82958 did induce minor therapeutic effects, as well as
undesired effects. Although the effects of SKF 82958 on fore-limb movements,
rotational behaviours and body displacement were comparable in the naive and
pretreated group, SKF 82958 re-initiated undesired effects in the L-DOPA
pretreated group from day one. It is concluded that the bilaterally MPTP-treated
monkey is an animal model with predictive validity for PD: it adequately predicts
the therapeutic effects and undesired effects of L-DOPA. Furthermore, it is
concluded that SKF 82958 is less effective than L-DOPA in the treatment of PD,
because it did not induce therapeutic effects, but instead elicited several
undesired effects.
PMID- 10780831
TI - RU-24969 disrupts d-amphetamine self-administration and responding for
conditioned reward via stimulation of 5-HT1B receptors.
AB - Behavioural and neurochemical evidence indicates a facilitatory effect of 5
hydroxytryptamine (5-HT), acting via 5-HT1B receptors, on dopamine (DA) systems.
To explore this interaction further, these experiments examined the effects of
the 5-HT1A/1B agonist RU-24969 on behaviours known to involve the mesolimbic DA
system. These behaviours were locomotor activity, intravenous self-administration
of d-amphetamine, responding for a conditioned reward (CR), and the response
potentiating effects of amphetamine on CR responding. Locomotor activity was
enhanced by 1 and 3 mg/kg RU 24969, and both doses also reduced responding for d
amphetamine (60 microg/kg/infusion). Changing the unit dose produced a
characteristic U-shaped dose-response curve. This dose-response relationship was
not apparent following injection of RU-24969. Across all unit infusion doses of
amphetamine, the level of responding was fairly constant. In the CR experiments,
rats responded for a conditioned stimulus that was previously paired with water.
RU-24969 completely disrupted responding for CR, and also abolished CR responding
in rats injected with 3 microg d-amphetamine in the nucleus accumbens. RU-24969
also markedly suppressed responding for water. The suppressant actions of RU
24969 on amphetamine self-administration and CR responding involve stimulation of
5-HT1B receptors, since they were reversed by the 5-HT1B/1D antagonist GR 127935
(3 mg/kg), but not by the 5-HT1A antagonist WAY-100635 (1 mg/kg). None of the
behavioural effects of RU-24969 are consistent with a selective action to enhance
mesolimbic DA function. Rather, global activation of 5-HT1B receptors appear to
exert a general disruptive effect on operant responding.
PMID- 10780832
TI - Disruption of the discriminative stimulus effects of S(+)-3,4
methylenedioxymethamphetamine (MDMA) by (+/-)-MDMA neurotoxicity: protection by
fluoxetine.
AB - This study utilized drug discrimination procedures to assess the functional
consequences of (+/-)-3,4-methylenedioxymethamphetamine (MDMA)-induced serotonin
depletion, and to determine whether concomitant injections of fluoxetine averted
these effects. Twelve male Sprague-Dawley rats were trained to discriminate S(+)
MDMA (1.5 mg/kg, s.c.) from saline in a two-lever, water-reinforced operant
procedure. After dose generalization tests were completed, training was
suspended, and subjects were administered saline injections twice daily for four
days. Ten days later, tests were conducted with S(+)-MDMA (1.5 mg/kg) and saline,
to ascertain that discriminative stimulus control was maintained in the absence
of training over a two-week period. All subjects received two additional weeks of
training. Subsequently, (+/-)-MDMA (20 mg/kg, s.c.) was administered twice daily
for four days, concomitantly with either 5.0 mg/kg fluoxetine (FLX) or saline
(SAL) injections, and stimulus generalization tests with S(+)-MDMA and SAL were
conducted after ten days. In the rats administered (+/-)-MDMA + SAL injections,
S(+)-MDMA-appropriate responding dropped from 99.24% to 44.99% during S(+)-MDMA
generalization tests, and rose from 2.78% to 22.14% during SAL generalization
tests. This disruption did not occur, however, in rats administered the
combination of (+/-)-MDMA and FLX injections. Subsequent training reestablished
discriminative stimulus control by S(+)-MDMA in the (+/-)-MDMA + SAL-treated
rats. Postmortem neurochemical assays indicated that 5-HT levels were
significantly reduced in the prefrontal cortices of rats given (+/-)-MDMA + SAL,
compared to both drug-naive control rats and (+/-)-MDMA + FLX-treated rats. 5
HIAA levels were significantly lower in the prefrontal cortices of both (+/-)
MDMA + SAL-treated rats and (+/-)-MDMA + FLX-treated rats, relative to control.
These results support previous findings that fluoxetine protects against (+/-)
MDMA-induced 5-HT depletion. Moreover, this study demonstrated that drug
discrimination is a sensitive assay in which to examine behavioral correlates of
(+/-)-MDMA-induced serotonergic deficits, and the protection against these
deficits by fluoxetine.
PMID- 10780833
TI - A comparison of two behavioral measures of psychomotor activation following
intravenous amphetamine or cocaine: dose- and sensitization-dependent changes.
AB - This paper presents data concerning the dose-effect relationships of
intravenously administered amphetamine and cocaine on two widely used measures of
psychomotor activation: locomotor crossover activity in neurologically intact
rats, and rotational behavior in rats with a unilateral 6-hydroxydopamine lesion.
There were marked differences in dose-effect relationships, both as a function of
drug and of behavioral measure. Amphetamine produced a linear increase in
rotational behavior over a wide range of doses (the highest effective dose was
76.8 times the lowest), but a linear increase in locomotor crossover activity
over only a narrow dose range (the highest effective dose was only four times the
lowest). In contrast, for cocaine, the dose-effect relationships for the two
behaviors were very similar, but for both behaviors the effective dose range was
quite narrow, the highest effective dose being only between two and four times
the lowest. The data highlight the advantages and disadvantages of these measures
as indices of the psychomotor activating effects of psychostimulant drugs.
PMID- 10780834
TI - Effect of nitric oxide synthesis inhibition on c-Fos expression in hippocampus
and cerebral cortex following two forms of learning in rats: an
immunohistochemistry study.
AB - This study investigated the effect of NO on c-Fos expression using
immunocytochemical techniques, following training in the one-trial passive
avoidance response and Morris water maze tasks. Fos-like immunoreactive (FLI)
neurons were examined in the hippocampus and cerebral cortex of rats in which
intracerebroventricular (i.c.v.) injection of Nomega-nitro-L-arginine (NAME) was
given 30 min before training in the experimental groups. The results showed that:
(1) when compared with untreated rats or rats receiving i.c.v. saline injection,
fos-like immunoreactive neurons were significantly increased in both brain
regions following training in either task, and (2) preceding i.c.v. injections of
NAME blocked both the formation of memory and the increased expression of c-Fos
in both brain regions subjected to training on the two models. These results
suggest that NO production may be a critical factor for the formation of memory
and the enhanced c-Fos expression, and so might contribute to the long-term
plasticity of synaptic organization in the two brain regions.
PMID- 10780835
TI - Intrahippocampal infusion of an inhibitor of protein kinase A separates short-
from long-term memory.
AB - Rats implanted bilaterally with cannulae in the CA1 region of the dorsal
hippocampus were trained in one-trial step-down inhibitory (passive) avoidance,
and tested for short- and long-term memory of this task at 1.5-3.0 and at 24 h
from training, respectively. At various times after training (0, 22, 45, 90, 135
or 175 min) they received a 0.5 microl infusion of the protein kinase A (PKA)
inhibitor, KT5720 (0.1 or 0.5 microg), or of its vehicle (20% dimethylsulfoxide
in saline). At the higher dose, KT5720 inhibited PKA activity by 90%. KT5720
blocked long-term memory (LTM) when given either 0 or 175 min posttraining, and
short-term memory (STM) when given 0, 22, 45 or 90 min post-training. Therefore,
PKA plays a different role in the process of formation of the two types of
memory. Its role in LTM may be related to the peak of PKA activity, and to the
levels of its substrate, nuclear P-CREB, that have been described in a previous
paper to occur at 0 and again at 3 h after training. The role of PKA in STM may
well involve other substrates of the enzyme. This finding points to a cleavage
between the mechanisms of STM and LTM formation.
PMID- 10780836
TI - Ethanol state dependence involving a lever press response requirement in rats.
AB - Previous studies have found that the timely completion of an FR10 schedule of
food-rewarded lever pressing in rats demonstrates state dependence in drug-to
saline state changes with benzodiazepines and NMDA antagonists, but not with
ethanol. We report here that, using sweetened condensed milk rather than food
pellets as a reward, ethanol nonetheless produces a symmetrical state dependence
with the lever press response requirement at doses that also impair acquisition.
Extensive parametric studies are needed to unravel the apparently subtle
conditions that govern the occurrence and features of the state dependence
produced by various CNS compounds.
PMID- 10780837
TI - Techniques of embryo transfer and facility decontamination used to improve the
health and welfare of transgenic mice.
AB - 'Reduction' and 'Refinement' can be achieved in transgenic mouse studies by re
deriving transgenic mouse lines and subsequently maintaining them under high
standards of husbandry in a unit with restricted access. This report describes
the initial steps of a project to improve the health and welfare of transgenic
mice at the European Molecular Biology Laboratory (EMBL), by re-deriving
transgenic lines as microbiologically defined animals to be maintained in a
barrier unit in a newly constructed animal facility. A pilot study showed that it
was possible to transfer embryos obtained from contaminated donor mice in the old
facility to specific pathogen free recipients housed in a ventilated cabinet in
the new unit, without concomitant carry over of disease. The offspring born
following embryo transfer were of high health status and did not show any
evidence of contamination with any of the pathogens present in the mice in the
old animal unit. Antibodies to various murine viruses (mouse hepatitis virus
(MHV), rota virus, reo-3 virus, Theilers encephalomyelitis virus, adenovirus) and
parasites were present in sentinel animals from the old animal house whereas the
re-derived animals were found to be free of virus antibodies and parasites.
Therefore the methods used were considered to be successful in terms of disease
prevention and enhancement of welfare. The barrier unit was sterilized without
the use of formaldehyde or related substances, to minimize the risks to personnel
and to the environment from using potentially dangerous substances. From the
results of in vitro and in vivo screening, the protocol for sterilization
described here was found to be effective in achieving microbiological sterility
of the barrier unit and was cost effective.
PMID- 10780838
TI - Home cage presentation of complex discrimination tasks to marmosets and rhesus
monkeys.
AB - The study reported here demonstrates the feasibility of presenting cognitive
tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) to
either marmosets or rhesus monkeys in their home cages. This location of testing
offers opportunities for the measurement of additional indices, for example
spontaneous behaviour (Prowse et al. 1995) and electrophysiology (Pearce et al.
1998) as well as facilitating repeated test presentation. Results from 12
marmosets and 4 rhesus monkeys which have completed several sequences of an eight
stage discrimination task involving simple discriminations, compound
discriminations and reversals are reported. The paradigm developed has
application in long-term studies. Tests from CANTAB have been used extensively in
normal humans (Robbins et al. 1994) as well as a range of patient groups (Owen et
al. 1992, Elliott et al. 1995) and to assess drug effects (Coull et al. 1996).
Additionally some of these tests have been presented to marmosets (Roberts et al.
1988) to examine neuropsychological functioning. This comparative approach
facilitates meaningful cross species comparison, particularly in the study of the
effects of pharmacological intervention.
PMID- 10780839
TI - Monitoring of piglets' open field activity and choice behaviour during the replay
of maternal vocalization: a comparison between Observer and PID technique.
AB - The paper presents a new system for the automatic monitoring of open field
activity and choice behaviour of medium-sized animals. Passive infrared motion
detectors (PID) were linked on-line via a digital I/O interface to a personal
computer provided with self-developed analysis software based on LabVIEW (PID
technique). The set up was used for testing 18 one-week-old piglets (Sus scrofa)
for their approach to their mother's nursing vocalization replayed through
loudspeakers. The results were validated by comparison with a conventional
Observer technique, a computer-aided direct observation. In most of the cases, no
differences were seen between the Observer and PID technique regarding the
percentage of stay in previously defined open field segments, the locomotor open
field activity, and the choice behaviour. The results revealed that piglets are
clearly attracted by their mother's nursing vocalization. The monitoring system
presented in this study is thus suitable for detailed behavioural investigations
of individual acoustic recognition. In general, the PID technique is a useful
tool for research into the behaviour of individual animals in a restricted open
field which does not rely on subjective analysis by a human observer.
PMID- 10780840
TI - The effect of cage size and enrichment on core temperature and febrile response
of the golden hamster.
AB - The aim of this study is to determine the effect of cage size and cage
enrichment. Golden hamsters were individually housed in standard cages of four
different sizes and in enriched cages of three different sizes since 3 weeks of
age. Each of the seven housing groups consisted of 12 hamsters. After 14 weeks of
housing in their respective environments the measurements started. The mean
baseline rectal temperature was significantly higher in hamsters housed in small
cages than in hamsters housed in large cages. After the injection of fever
inducing lipopolysaccharide rectal temperature increased by 1 to 2 degrees C. The
increase of rectal temperature and the fever index were the highest in animals
housed in large cages and the smallest in animals housed in small cages. Through
cage enrichment and increasing cage size the mean febrile response increased
while the mean baseline rectal temperature decreased. Cage size and cage
enrichment had no effect on the dispersion of the measured values. The
differences in microclimate between large and small cages were too small to have
an effect on thermoregulation. The results indicate that housing in small cages
induce chronic stress which obviously affects thermoregulation. The findings
demonstrate that the results of some physiological experiments are significantly
influenced by the pre-experimental housing conditions.
PMID- 10780841
TI - Housing conditions affect susceptibility to mercury in the golden hamster.
AB - Individually-housed and group-housed golden hamsters (Mesocricetus auratus), aged
8 weeks, were studied with regard to their susceptibility to a single gavage of
mercuric chloride (10 mg/kg body weight). Body weight and food consumption were
measured for 10 days (day -9 to day 0) in a pre-application period and for 13
days (day 1 to day 13) in a post-application period. Mercuric chloride
administration significantly reduced body weight gain in both isolated and
grouped hamsters at day 1 compared to vehicle controls. While the individually
housed treated hamsters recovered during the post-application period, the group
housed treated hamsters showed a reduced body weight gain over the whole post
application period. Results are discussed in relation to elevated susceptibility
to intoxication in group-housed hamsters triggered by high social stress. This
study highlights the need to carefully consider the housing conditions which can
influence the results of teratological experiments.
PMID- 10780842
TI - The influence of pre-anaesthetic administration of buprenorphine on the
anaesthetic effects of ketamine/medetomidine and pentobarbitone in rats and the
consequences of repeated anaesthesia.
AB - Rats received pentobarbitone (60, 48 and 36 mg/kg i.p.) or ketamine/medetomidine
(75/100, 60/80 and 45/60 mg/microg/kg i.p.) alone, or one hour following
buprenorphine (0.5 mg/kg s.c.). Animals were anaesthetized once per week for 6
weeks with one of three anaesthetic doses according to a randomized block design.
In the pentobarbitone group, animals which received buprenorphine had longer
sleep times (236 +/- 22 cf. 204 +/- 21 min) and longer durations of surgical
anaesthesia (83 +/- 14 cf. 27 +/- 8 min) (P<0.01), these effects being
potentiated with increasing anaesthetic doses (P<0.01). A greater degree of
respiratory depression was found in animals that received buprenorphine (P<0.01)
although this was judged clinically acceptable in all cases. Unexpectedly high
mortality and a high incidence of anaesthetic complications (nine of 16 animals)
in the ketamine/medetomidine group made statistical analysis of these data
impossible. We conclude that for pentobarbitone, pre-anaesthetic administration
of buprenorphine reduces the dose of anaesthetic required to produce surgical
anaesthesia, in addition to the presumed benefits of pre-emptive analgesia. In
view of the high mortality encountered, we advise caution when considering pre
anaesthetic use of opioids in combination with ketamine/medetomidine in rats.
PMID- 10780843
TI - Comparison of the effects of four anaesthetic agents on somatosensory evoked
potentials in the rat.
AB - Electrophysiological techniques provide an objective and non-invasive measure of
neurological function. In order to undertake detailed evoked potential studies in
rats on repeated occasions, it is necessary to find an appropriate anaesthetic
agent which has minimal and reproducible effects on the parameters to be studied
and also has a minimal effect on the general welfare of the animals. In this
study we compared the effects of four common anaesthetic agents (ketamine
xylazine, medetomidine, isoflurane and fentanyl/fluanisone-midazolam) on
somatosensory evoked potentials (SEPs) in rats following electrical stimulation
of the fore- and hind-paw. Fentanyl/fluanisone-midazolam was found to be well
tolerated by the animals and to have, in general, the least deleterious effect on
SEPs. For example, the response recorded at the level of the somatosensory cortex
(P1), following forelimb stimulation, appeared on average 1.80 ms earlier with
fentanyl/fluanisone-midazolam than with the other agents and the peak-to-peak
amplitude (CI to CII) of the response recorded at the cervical (C3) level was on
average 5.86 microV greater with fentanyl/fluanisone-midazolam.
Fentanyl/fluanisone-midazolam is, therefore, recommended as the anaesthetic of
choice for longitudinal studies of SEPs in the rat.
PMID- 10780845
TI - A rapid and non-surgical procedure for jugular catheterization of pigs.
AB - A rapid and non-surgical method for jugular catheterization in pigs was set up in
30 piglets of 6.2 kg, 23 pigs of 46 kg and 84 kg and two lactating multiparous
sows. The animal was restrained on a V-shaped table (piglets) or with a rope
around the mandible (slaughter pigs and sows). The vein was located with the
Vacutainer system and a wire guide was inserted into the Vacutainer needle up to
the vein lumen. When the needle was removed, the catheter was inserted over the
wire guide and advanced until it penetrated the skin and thereafter, the vein
wall. The catheter was fixed outside by a large tape and coiled inside a patch
just behind the ears. The technique utilizes readily available material and is no
more risky for the animal than a single blood sampling. Moreover, it can be
performed within 15 to 20 min (including animal restraint) within pens. This new
approach might have important implications not only for research purposes by
facilitating repeated blood samplings but also for projects which require a rapid
and easy method for testing of any kind of pharmaceutical or other type of
products under husbandry conditions.
PMID- 10780844
TI - The effect of buprenorphine on the course of disease in laboratory rabbits
infected with myxoma virus.
AB - The only method of assessing the virulence of myxoma virus is to record survival
times of rabbits inoculated with the virus. This raises ethical concerns about
using animals in experiments where death is the end point. We investigated
whether or not the opioid analgesic buprenorphine could be used in rabbits
without compromising the myxoma virus virulence assay and on the presumption that
animals may suffer pain during the course of the disease. Thirty, 5-month-old New
Zealand White rabbits were divided into two groups stratified for weight and
gender, and inoculated intradermally with 100 pfu of the Standard Laboratory
Strain (SLS) of myxoma virus. At day 6 post infection (p.i.), when eyelid
swelling was first seen, each animal in one group was treated with 0.03 mg/kg
buprenorphine, subcutaneously, morning and evening until death. Animals in the
other group were untreated. Animals were weighed daily and rectal temperatures
taken morning and evening. Intake of food and water was assessed as was general
demeanor including respiratory effort. There was no significant difference in
mean survival time, weight change, or demeanor between the two groups. Increased
respiratory effort was seen from day 10 p.i. in animals surviving up to and
beyond that time but again there was no difference between groups. Animals
treated with buprenorphine refused food and water a day earlier than untreated
animals, and had lower temperatures immediately prior to death. It was concluded
that the opiate analgesic buprenorphine can be used without compromising the
current virulence assay for the SLS of myxoma virus in New Zealand White rabbits
but that the clinical signs of myxomatosis that could be attributed to pain were
not abrogated.
PMID- 10780846
TI - Effects of coprophagy on serum urea and the weight of the gastrointestinal tract
of fed or fasted rats.
AB - Coprophagy can be minimized by fitting rat cages with metal grids which allow
faecal pellets to pass through to the floor of the cage. When bedding was omitted
overnight, the extent of coprophagy could be estimated from the weight of the
droppings on the cage floor or the weight of the gastrointestinal (GI) tract
removed from rats housed with or without grids. The effect of coprophagy was also
demonstrated by the elevation of serum urea nitrogen in rats that consumed
faeces. Therefore, precautions against coprophagy, or their absence, should be
specified in all experimental protocols and reports.
PMID- 10780847
TI - Evaluation of hypothalamo-pituitary-adrenal activity in the tree shrew (Tupaia
belangeri) via salivary cortisol measurement.
AB - Saliva sampling is frequently used in humans for adrenal glucocorticoid hormone
analysis because of advantages such as non-invasiveness, the ease of collection,
and storing of the samples. To transfer this advantageous method to laboratory
mammals, potentially confounding factors such as stressful handling procedures
have to be excluded. In the present study we established a method for collecting
saliva for cortisol measurement in freely moving adult male tree shrews (Tupaia
belangeri). The practicability of the procedure was demonstrated (i) by stress
induced changes in cortisol levels revealing a significant increase during the
stress phase (control = 0.91 nmol/l vs stress = 1.71 nmol/l), and (ii) by
reporting no significant differences in salivary cortisol levels before and after
performance of a learning task. The present study emphasizes the use of salivary
cortisol analysis especially for monitoring acute changes in the hypothalamo
pituitary-adrenal axis activity in male tree shrews.
PMID- 10780848
TI - Haematology and serum chemistry parameters of the pregnant rat.
AB - This study describes the baseline haematology and serum chemistry values found in
non-pregnant, pregnant (gestational days [GD] 2-21) and lactating (postnatal days
1-9) Sprague Dawley rats (n = 3-10/day) from the NCTR breeding colony of Crl:COBS
CD(SD)BR strain. Maternal body weights on GD0 ranged from 250 to 300 g. Multiple
analytes were measured in both whole blood and serum of dams. Amniotic fluid,
fetal serum, and postnatal pup serum analyte values were also acquired. Maternal
blood was collected from the heart under subterminal carbon dioxide (CO2)
anaesthesia. Most pregnant dam blood values were not appreciably different from
values for non-pregnant dams until near term; near-term values for some analytes
(red blood cells, haemoglobin, haematocrit, mean corpuscular haemoglobin
concentration, alkaline phosphatase, albumin, total protein, glucose, total
bilirubin, sodium, and chloride) decreased but returned to near-normal values
soon after delivery. The most dramatic change was a three-fold elevation of serum
triglyceride levels near term with a subsequent decrease at birth. Most serum
chemistry analytes measured in progeny increased after birth except for alkaline
phosphatase, calcium and potassium levels which decreased.
PMID- 10780849
TI - Immunohistological characterization of leukocytes in the lungs of healthy mice
and after bacterial intratracheal infection.
AB - Leukocytes in the peripheral lung parenchyma of mice have not been characterized
histologically during bacterial infection. The aim of this study was to
investigate (a) the immunohistological characteristics of healthy murine lungs
and (b) the cell kinetics during acute inflammation. BALB/c and MF1 mice were
examined; as well as transgenic mice with the gene defect of cystic fibrosis (CF)
in the airways as an animal model for this disease. MF1 mice served as controls
for the transgenic animals. Lavaged and perfused lungs were snap frozen. B and T
lymphocytes, CD4+ and CD8+ cells, dendritic cells, neutrophils and a subset of
macrophages were enumerated on cryostat lung sections. The lung tissue and
bronchoalveolar lavage (BAL) of BALB/c mice, infected intratracheally with
Haemophilus influenzae type b (Hib), were studied at different time points after
infection. In the lungs of healthy mice, including CF mice, the largest
population was that of T cells, CD4+ cells being always more frequent than CD8+
cells. During acute inflammation the number of neutrophils in the lung parenchyma
and BAL increased strongly within the first hours after bacterial instillation
and reached baseline levels within one week. This study provides a semi
quantitative analysis of immunocompetent cells in normal and infected murine lung
tissue. Differences in cell numbers are found between different strains.
Moreover, the cellular reaction during Hib infection in mouse lungs is dominated
by neutrophils, as expected in a primary immune response. In uninfected CF mice
the numbers and distribution of immune cells in the lung tissue are normal,
indicating that the cellular defense is adequate.
PMID- 10780850
TI - The ethical acceptability of animal experiments: a proposal for a system to
support decision-making.
AB - We describe a system to support decision-making on the ethical acceptability of
animal experiments for scientific researchers and others responsible for ethical
decision-making in animal experiments. The system consists of eight steps. Each
step contains a number of substantive questions or a computational rule, leading
to a well-articulated moral judgment on specific animal experiments. The system
comprises a number of moral assumptions and pre-emptive norms, but leaves enough
room for moral discretion and personal responsibility. The general ethical ideas
behind the moral choices and assumptions are sketched and potential objections to
the overall approach are discussed.
PMID- 10780851
TI - Mousepox: a threat to mouse colonies.
PMID- 10780852
TI - Suppressed bone turnover by bisphosphonates increases microdamage accumulation
and reduces some biomechanical properties in dog rib.
AB - It has been hypothesized that suppression of bone remodeling allows microdamage
to accumulate, leading to increased bone fragility. This study evaluated the
effects of reduced bone turnover produced by bisphosphonates on microdamage
accumulation and biomechanical properties of cortical bone in the dog rib. Thirty
six female beagles, 1-2 years old, were divided into three groups. The control
group (CNT) was treated daily for 12 months with saline vehicle. The remaining
two groups were treated daily with risedronate (RIS) at a dose of 0.5 mg/kg per
day or alendronate (ALN) at 1.0 mg/kg per day orally. After sacrifice, the right
ninth rib was assigned to cortical histomorphometry or microdamage analysis. The
left ninth rib was tested to failure in three-point bending. Total cross
sectional bone area was significantly increased in both RIS and ALN compared with
CNT, whereas cortical area did not differ significantly among groups. One-year
treatment with RIS or ALN significantly suppressed intracortical remodeling (RIS,
53%; ALN, 68%) without impairment of mineralization and significantly increased
microdamage accumulation in both RIS (155%) and ALN (322%) compared with CNT.
Although bone strength and stiffness were not significantly affected by the
treatments, bone toughness declined significantly in ALN (20%). Regression
analysis showed a significant nonlinear relationship between suppressed
intracortical bone remodeling and microdamage accumulation as well as a
significant linear relationship between microdamage accumulation and reduced
toughness. This study showed that suppression of bone turnover by high doses of
bisphosphonates is associated with microdamage accumulation and reduced some
mechanical properties of bone.
PMID- 10780853
TI - True strength.
PMID- 10780854
TI - Chromosomal mapping of osteopenia-associated quantitative trait loci using
closely related mouse strains.
AB - Peak bone mineral density (BMD) is a highly heritable trait in humans and is
currently the best predictor of skeletal fragility underlying osteoporosis. The
SAMP6 mouse strain displays unusually low BMD at maturity, and age-dependent
osteopenia associated with defective osteoblastogenesis. To identify quantitative
trait loci (QTLs) influencing bone density, we constructed crosses between SAMP6
and either AKR/J or SAMP6, two related mouse strains of higher peak BMD. Due to
common ancestry of these strains, intercross parents differed at only 39-40% of
227 highly-polymorphic genotyping markers, thus restricting our search to this
informative portion of the genome and reducing the number of mice required for
QTL significance. Using dual energy X-ray absorptiometry (DEXA), we measured
spinal BMD in F2 cross progeny at 4 months of age, and selectively genotyped
those in the highest and lowest quartiles for BMD. Based on linear regression of
bone density on genotype, including Composite Interval Mapping to enhance mapping
precision while adjusting for effects of distal markers, we identified multiple
QTLs significantly affecting spinal BMD; these were mapped to regions of
chromosomes 2 (two sites, one confirmed in both crosses), 7, 11, 13 and 16. One
of these loci had been previously identified as a significant bone-density QTL,
while 3 substantiate QTLs suggested by a low-power study of 24 recombinant-inbred
mouse lines. Such recurrent appearance of QTLs, especially in crosses involving
distantly-related strains, implies that polymorphism at these loci may be favored
by evolution and might underlie variation in peak bone density among humans.
PMID- 10780855
TI - Transforming growth factor-beta1 gene polymorphism, bone turnover, and bone mass
in Italian postmenopausal women.
AB - Transforming growth factor beta1 (TGF-beta1) is abundant in bone and is an
important regulator of the osteoclastic-osteoblastic interaction (coupling). The
sequence variation, 713-8delC in the TGF-beta1 gene has previously been found to
be associated with very low bone mass in osteoporotic women and with increased
bone turnover in both osteoporotic and normal women. The possible association of
this polymorphism with bone mass and bone turnover has now been investigated in
256 postmenopausal Italian women. A significant association of TGF-beta1 with
bone mass was detected in the populations. Subjects carrying the sequence
variation 713-8delC (Tt) genotype showed a significantly lower bone mineral
density (BMD) at the hip than those without sequence variation in the genotype
(TT). Individuals carrying the tt genotype have a more severe osteoporosis
(P=0.0001 vs. TT and Tt genotypes). The frequency of the fragility fractures was
significantly lower in individuals with TT genotype than in those with the Tt and
tt genotypes (X2=21.9; P=0.006). Furthermore a significant association was found
between 713-8delC and bone turnover. The results suggest a strong evidence for an
association among the 713-8delC allele of the TGF-beta1 gene and the femoral BMD,
the prevalence of osteoporotic fractures, and finally a high bone turnover in a
sample of Italian postmenopausal women.
PMID- 10780856
TI - Expression of osteoclast differentiation signals by stromal elements of giant
cell tumors.
AB - The mechanisms by which primary tumors of the bone cause bone destruction have
not been elucidated. Unlike most other lytic bone tumors, osteoclastomas,
otherwise known as giant cell tumors (GCT), contain osteoclast-like cells within
the tumor stroma. A new member of the TNF-ligand superfamily member, osteoclast
differentiation factor (ODF/OPGL/RANKL/TRANCE), was recently identified. ODF was
shown to directly stimulate osteoclastogenesis, in the presence of M-CSF. In this
study, the expression of ODF was examined in a number of tumor samples associated
with bone lysis in vivo. In addition, we investigated expression of the ODF
receptor on osteoclast precursors, RANK, as well as the ODF inhibitor
osteoprotegerin (OPG), and another TNF-ligand superfamily member, TRAIL,
previously shown to abrogate the inhibitory effects of OPG. We report here the
novel finding that GCT stromal cells contain abundant ODF mRNA, whereas the giant
cell population exclusively expresses RANK mRNA. These results are consistent
with the osteoclast-mediated bone destruction by these tumors. We also report the
expression of OPG and TRAIL mRNA in GCT samples. A comparison with other lytic
and nonlytic tumors of bone showed that GCT express more ODF and TRAIL mRNA
relative to OPG mRNA. In addition, GCT were found to express a number of
cytokines previously reported to play central roles in osteoclastogenesis,
namely, IL-1, -6, -11, -17, as well as TNF-alpha. Importantly, GCT were also
found to express high levels of M-CSF mRNA, a cytokine shown to be an essential
cofactor of ODF, and a survival factor for mature and developing osteoclasts.
Furthermore, expression of these molecules by stromal cells isolated from GCT
continued in vitro. Thus GCT constitutively express all of the signals that are
currently understood to be necessary for the differentiation of osteoclasts from
precursor cells.
PMID- 10780857
TI - Compactin suppresses bone resorption by inhibiting the fusion of prefusion
osteoclasts and disrupting the actin ring in osteoclasts.
AB - Compactin (mevastatin), which inhibits 3-hydroxy-3-methylglutaryl-coenzyme A (HMG
CoA) reductase, and thus biosynthesis of cholesterol and the prenylation of
proteins, inhibits osteoclastic bone resorption. Although it has been suggested
that compactin inhibits bone resorption by inducing apoptosis of osteoclasts, the
pathway by which compactin inhibits resorption has not been established. We
investigated the effect of compactin on the differentiation of osteoclasts and
the relationship between the morphological changes elicited by compactin and its
inhibitory effect on bone resorption. Compactin inhibited the differentiation of
osteoclasts, interfering with the fusion process by which prefusion osteoclasts
(pOCs) develop into multinucleated osteoclast-like cells (OCLs), and also
disrupted the actin ring of OCLs. The potency of compactin to inhibit fusion of
pOCs and to disrupt the actin ring of OCLs corresponded to that of compactin to
inhibit bone resorption. The effects of compactin were prevented by the addition
of MVA lactone or its downstream products farnesylpyrophosphate (FPP) and
geranylgeranyl-pyrophosphate (GGPP) but not by squalene. Apoptosis of OCLs was
not induced by the concentration of compactin that inhibited fusion of pOCs and
disrupted the actin ring. The normal process of pOC fusion and the integrity of
the actin ring were restored by the withdrawal of compactin from the cultures
after they had been treated with compactin for 24 h, but they were not restored
by the addition of zVAD-fmk, a caspase inhibitor. Compactin also reversibly
inhibited interleukin-1beta (IL-1beta)-, 1alpha,25-dihydroxyvitamin D3 (1
alpha,25(OH)2D3)-, and parathyroid hormone (PTH)-stimulated 45Ca release in bone
organ cultures. Our results indicate that the inhibitory effects of compactin on
bone resorption result from the inhibition of fusion of pOCs into OCLs and
disruption of actin ring in OCLs and that apoptosis of OCLs is not necessary for
these inhibitory effects of compactin. These effects of compactin are likely to
be a consequence of the inhibition of prenylation of proteins that play an
important role in the fusion of pOCs and in maintaining actin ring integrity in
OCLs.
PMID- 10780858
TI - Essential requirement of BMPs-2/4 for both osteoblast and osteoclast formation in
murine bone marrow cultures from adult mice: antagonism by noggin.
AB - Bone morphogenetic proteins (BMPs) have been heretofore implicated in the
induction of osteoblast differentiation from uncommitted progenitors during
embryonic skeletogenesis and fracture healing. We have tested the hypothesis that
BMPs are also involved in the osteoblastogenesis that takes place in the bone
marrow in postnatal life. To do this, we took advantage of the properties of
noggin, a recently discovered protein that binds BMP-2 and -4 and blocks their
action. Addition of human recombinant noggin to bone marrow cell cultures from
normal adult mice inhibited both osteoblast and osteoclast formation; these
effects were reversed by exogenous BMP-2. Consistent with these findings, BMP-2
and -4 and BMP-2/4 receptor transcripts and proteins were detected in these
primary cultures, in a bone marrow-derived stromal/osteoblastic cell line, as
well as in murine adult whole bone; noggin expression was also documented in all
these preparations. Moreover, addition of antinoggin antibody caused an increase
in osteoblast progenitor formation. These findings suggest that BMP-2 and -4 are
expressed in the bone marrow in postnatal life and serve to maintain the
continuous supply of osteoblasts and osteoclasts; and that, in fact, BMP-2/4
induced commitment to the osteoblastic lineage is a prerequisite for osteoclast
development. Hence, BMPs, perhaps in balance with noggin and possibly other
antagonists, may provide the tonic baseline control of the rate of bone
remodeling on which other inputs (e.g., hormonal, biomechanical, etc.) operate.
PMID- 10780860
TI - Protein undernutrition-induced bone loss is associated with decreased IGF-I
levels and estrogen deficiency.
AB - Protein undernutrition is a known factor in the pathogenesis of osteoporotic
fracture in the elderly, but the mechanisms of bone loss resulting from this
deficiency are still poorly understood. We investigated the effects of four
isocaloric diets with varying levels of protein content (15, 7.5, 5, and 2.5%
casein) on areal bone mineral density (BMD), bone ultimate strength,
histomorphometry, biochemical markers of bone remodeling, plasma IGF-I, and sex
hormone status in adult female rats. After 16 weeks on a 2.5% casein diet, BMD
was significantly decreased at skeletal sites containing trabecular or cortical
bone. Plasma IGF-I was decreased by 29-34% and no estrus sign in vaginal smear
was observed. To investigate the roles of estrogen deficiency and protein
undernutrition, the same protocol was used in ovariectomized (OVX) or sham
operated (SHAM) rats, pair-fed isocaloric diets containing either 15 or 2.5%
casein. Trabecular BMD was decreased by either manipulation, with effects
appearing to be additive. Cortical BMD was decreased only in rats on a low
protein diet. This was accompanied by an increased urinary deoxypyridinoline
excretion without any change in osteocalcin levels, suggesting an uncoupling
between resorption and formation. Isocaloric protein undernutrition decreased
bone mineral mass and strength. This effect might be related to decreased plasma
IGF-I and/or estrogen deficiency with a consequent imbalance in bone remodeling.
PMID- 10780859
TI - A novel synthetic triazolotriazepine derivative JTT-606 inhibits bone resorption
by down-regulation of action and production of bone resorptive factors.
AB - In the search for a new class of bone-sparing agents, we have conducted random
screening of the domestic chemical library using 45Ca release assay from
prelabeled cultured neonatal mouse calvariae and identified a novel synthetic
triazolotriazepine JTT-606 as a candidate for a potent inhibitor of bone
resorption. JTT-606 inhibited 45Ca release dose dependently not only in the
control calvarial culture but also in the stimulated cultures by interleukin
1alpha (IL-1alpha), fibroblast growth factor 2 (FGF-2), and parathyroid hormone
(PTH). JTT-606 also inhibited both basal and stimulated osteoclast-like (OCL)
cell formation in the coculture of mouse osteoblastic cells and bone marrow cells
dose dependently, indicating its inhibitory effect on osteoclast differentiation.
Ex vivo OCL cell formation by cultured bone marrow cells collected from
ovariectomized (OVX) mice also was decreased dose dependently by in vivo
application of JTT-606 to a level similar to that from sham-operated mice.
Furthermore, JTT-606 inhibited resorbed pit formation by isolated mature
osteoclasts as well as by unfractionated bone cells derived from rabbit long
bones in the control and FGF-2-stimulated cultures dose dependently, indicating
both the direct and the indirect actions of JTT-606 on mature osteoclast
function. In addition, JTT-606 reduced production of IL-1alpha, tumor necrosis
factor alpha (TNF-alpha), IL-6, and granulocyte-macrophage colony-stimulating
factor (GM-CSF) in the human peripheral blood mononuclear cell culture. In vivo
analyses of mature OVX rats revealed that the application of JTT-606 for 12 weeks
increased the BMD of the lumbar spine and decreased the levels of serum
osteocalcin and urine deoxypyridinoline to levels similar to those of 17beta
estradiol-treated OVX rats. We propose that JTT-606 may inhibit both osteoclast
differentiation and function by down-regulating both the action and the
production of bone resorptive factors. It is speculated that JTT-606 could be a
potent agent for the treatment of osteopenic disorders with elevated osteoclastic
bone resorption.
PMID- 10780861
TI - Fractal dimension of trabecular bone projection texture is related to three
dimensional microarchitecture.
AB - The purpose of this work was to understand how fractal dimension of two
dimensional (2D) trabecular bone projection images could be related to three
dimensional (3D) trabecular bone properties such as porosity or connectivity. Two
alteration processes were applied to trabecular bone images obtained by magnetic
resonance imaging: a trabeculae dilation process and a trabeculae removal
process. The trabeculae dilation process was applied from the 3D skeleton graph
to the 3D initial structure with constant connectivity. The trabeculae removal
process was applied from the initial structure to an altered structure having 99%
of porosity, in which both porosity and connectivity were modified during this
second process. Gray-level projection images of each of the altered structures
were simply obtained by summation of voxels, and fractal dimension (Df) was
calculated. Porosity (phi) and connectivity per unit volume (Cv) were calculated
from the 3D structure. Significant relationships were found between Df, phi, and
Cv. Df values increased when porosity increased (dilation and removal processes)
and when connectivity decreased (only removal process). These variations were in
accordance with all previous clinical studies, suggesting that fractal evaluation
of trabecular bone projection has real meaning in terms of porosity and
connectivity of the 3D architecture. Furthermore, there was a statistically
significant linear dependence between Df and Cv when phi remained constant.
Porosity is directly related to bone mineral density and fractal dimension can be
easily evaluated in clinical routine. These two parameters could be associated to
evaluate the connectivity of the structure.
PMID- 10780862
TI - Changes in cortical bone mineralization in the developing mandible: a three
dimensional quantitative computed tomography study.
AB - Quantitative computed tomography (QCT) was completed in 34 subjects between the
ages of 9 and 33 years with symmetrical mandibles in order to investigate the
three-dimensional cortical bone mineral density (BMD) distribution in the
mandible. The number and distribution of the pixels were determined at three
levels: (1) representing the entire mandibular bone; (2) the cortical bone at 60%
above the baseline defined as the segmentation level (around 1050 mg/cm3) and
representative of only cortical bone; and (3) the highest mineralized cortical
bone (>1250 mg/cm3). The geometrical distribution of the highest mineralized
areas was evaluated by three-dimensional reconstruction of the images. The total
number of pixels for the entire mandible increased significantly at each time
point represented at four increasing ages groups (9-11 years of age, 12-14 years
of age, 15-17 years of age, and >18 years of age). The male and female subjects
had a similar total number of pixels for the entire mandible before the age of
11, but the male subjects showed a significantly larger total number of
mandibular pixels after that age. Comparison of the number of pixels for pure
cortical bone (60% segmentation level) and the highest mineralized cortical bone
indicated a significant increase with maturation with the greatest change
occurring between the 13-year and 16-year age groups. However, the ratio of
cortical bone/total bone increased at a more rapid rate in the male subjects and
reached a plateau by the 16-year age group, showing distinct differences in
mineralization of the mandible between the sexes.
PMID- 10780863
TI - Risk factors for longitudinal bone loss in elderly men and women: the Framingham
Osteoporosis Study.
AB - Few studies have evaluated risk factors for bone loss in elderly women and men.
Thus, we examined risk factors for 4-year longitudinal change in bone mineral
density (BMD) at the hip, radius, and spine in elders. Eight hundred elderly
women and men from the population-based Framingham Osteoporosis Study had BMD
assessed in 1988-1989 and again in 1992-1993. BMD was measured at femoral neck,
trochanter, Ward's area, radial shaft, ultradistal radius, and lumbar spine using
Lunar densitometers. We examined the relation of the following factors at
baseline to percent BMD loss: age, weight, change in weight, height, smoking,
caffeine, alcohol use, physical activity, serum 25-OH vitamin D, calcium intake,
and current estrogen replacement in women. Multivariate regression analyses were
conducted with simultaneous adjustment for all variables. Mean age at baseline
was 74 years +/-4.5 years (range, 67-90 years). Average 4-year BMD loss for women
(range, 3.4-4.8%) was greater than the loss for men (range, 0.2-3.6%) at all
sites; however, BMD fell with age in both elderly women and elderly men. For
women, lower baseline weight, weight loss in interim, and greater alcohol use
were associated with BMD loss. Women who gained weight during the interim gained
BMD or had little change in BMD. For women, current estrogen users had less bone
loss than nonusers; at the femoral neck, nonusers lost up to 2.7% more BMD. For
men, lower baseline weight and weight loss also were associated with BMD loss.
Men who smoked cigarettes at baseline lost more BMD at the trochanter site.
Surprisingly, bone loss was not affected by caffeine, physical activity, serum 25
OH vitamin D, or calcium intake. Risk factors consistently associated with bone
loss in elders include female sex, thinness, and weight loss, while weight gain
appears to protect against bone loss for both men and women. This population
based study suggests that current estrogen use may help to maintain bone in
women, whereas current smoking was associated with bone loss in men. Even in the
elderly years, potentially modifiable risk factors, such as weight, estrogen use,
and cigarette smoking are important components of bone health.
PMID- 10780864
TI - Patients with prior fractures have an increased risk of future fractures: a
summary of the literature and statistical synthesis.
AB - Numerous studies have reported increased risks of hip, spine, and other fractures
among people who had previous clinically diagnosed fractures, or who have
radiographic evidence of vertebral fractures. However, there is some variability
in the magnitudes of associations among studies. We summarized the literature and
performed a statistical synthesis of the risk of future fracture, given a history
of prior fracture. The strongest associations were observed between prior and
subsequent vertebral fractures; women with preexisting vertebral fractures
(identified at baseline by vertebral morphometry) had approximately 4 times
greater risk of subsequent vertebral fractures than those without prior
fractures. This risk increases with the number of prior vertebral fractures. Most
studies reported relative risks of approximately 2 for other combinations of
prior and future fracture sites (hip, spine, wrist, or any site). The confidence
profile method was used to derive a single pooled estimate from the studies that
provided sufficient data for other combinations of prior and subsequent fracture
sites. Studies of peri- and postmenopausal women with prior fractures had 2.0 (95
% CI = 1.8, 2.1) times the risk of subsequent fracture compared with women
without prior fractures. For other studies (including men and women of all ages),
the risk was increased by 2.2 (1.9, 2.6) times. We conclude that history of prior
fracture at any site is an important risk factor for future fractures. Patients
with a history of prior fracture, therefore, should receive further evaluation
for osteoporosis and fracture risk.
PMID- 10780865
TI - Skeletal effects of parathyroid hormone infusion in ovariectomized rats with or
without estrogen repletion.
AB - We employed skeletally matured rats to study changes in biochemical markers of
bone turnover, bone mineral density (BMD), and bone biomechanics produced by
continuous elevation of parathyroid hormone (PTH) in estrogen-deplete and
replete rodents. Ninety-six 7-month-old virgin female rats were divided randomly
into 12 groups (n = 8) and treated as follows. One group was killed on the day of
surgery. The remaining groups were either bilaterally ovariectomized (Ovx) or
sham-operated and left untreated for 8 weeks, at which point, two groups, one
sham and one Ovx, were killed. The remaining nine groups were treated for 2 weeks
or 4 weeks. One sham and two Ovx groups received subcutaneous implants of Alzet
miniosmotic pumps with vehicle for PTH. Two Ovx groups were given pumps with
vehicle as well as a subcutaneous implant of 17beta-estradiol, which delivered 10
microg/kg per day. Two Ovx groups were implanted with rat PTH(1-34) in Alzet
miniosmotic pumps, which delivered 30 microg PTH/kg per day. Two Ovx groups were
implanted with both estradiol pellets and PTH-loaded pumps. One group of Ovx
animals from each treatment was killed after 2 weeks and the other after 4 weeks.
Biochemical markers of bone turnover, serum osteocalcin and urinary free
pyridinoline, BMD, and mechanical strength of excised bones were measured. As
expected, there was a significant increase in N-terminal PTH and serum calcium
levels in all PTH infusion groups. Both serum osteocalcin and urinary
pyridinoline showed a rapid increase within the first 2 weeks of the PTH infusion
and remained elevated at week 4. In estrogen-replete groups, osteocalcin
increased by week 2 of PTH infusion but pyridinoline did not increase until week
4. BMD of the distal and proximal femur showed the expected decrease 8 weeks
after ovariectomy but did not exhibit any further changes during the 4 weeks of
treatment with vehicle. Four weeks of PTH infusion in Ovx animals resulted in BMD
loss at the midshaft, distal, and proximal regions of the femur. Estrogen
repletion by itself, beginning 8 weeks after ovariectomy, produced no change in
BMD at any site when compared with from Ovx vehicle-treated rats. Estrogen
repletion in PTH-infused Ovx animals resulted in significant improvements of BMD
comparable with sham-operated animals at all three femoral regions. The
indentation test at the cancellous bone of the distal femur, three-point bending
test at the midshaft femur, and cantilever bending test at the femoral neck
showed that the changes in mechanical strength in these sites were consistent to
the changes found in BMD. Our results showed that (1) continuously elevated
levels of PTH induced additional loss of BMD in estrogen-deficient animals beyond
the rapid bone loss phase associated with ovariectomy, (2) estrogen repletion,
given by implant, to PTH-infused Ovx animals, reversed these BMD changes
increasing BMD to levels comparable with estrogen-sufficient rats, and (3) these
changes were reflected in the mechanical strength determined at these sites.
These results lend experimental support that hormone replacement therapy may
benefit bone health in postmenopausal women with primary hyperparathyroidism
(PHPT). In addition, it raises the possibility that a continuous elevation of PTH
could exert anabolic effects on skeletal tissue if its catabolic component can be
minimized.
PMID- 10780866
TI - Long-term corticosteroid therapy induces mild changes in trabecular bone texture.
AB - The relative roles of bone mineral density (BMD) decrease and of
microarchitectural changes in corticosteroid-induced osteoporosis (CIOP) are
debated. Our objective has been to evaluate both bone microarchitecture (by a
fractal analysis of texture on radiographs) and BMD in corticosteroid (CS)
treated patients. In this study, 60 patients from a rheumatology unit with a mean
age of 60.6+/-14.8 years taking CS therapy for more than 6 months and a
cumulative dose of prednisone over 1 g and 57 controls among age-matched patients
and hospital staff were recruited. Bone diseases and bone-modifying drugs (except
calcium, vitamin D, and hormonal replacement therapy [HRT]) were considered as
exclusion criteria. A fractal analysis of trabecular bone texture was performed
on calcaneus radiographs after an oriented analysis in 18 directions. The fractal
analysis was based on the fractional Brownian motion model. Results were
expressed by H parameter (H = 2 - fractal dimension) in each direction, Hmean
being the average of 18 directions, Hmini the minimum, and Hmaxi the maximum. BMD
was measured by double-energy X-ray absorptiometry (DEXA) at the femoral neck
(FN) and lumbar spine (LS). The odds ratios (OR) were calculated for a variation
of 1 SD. The mean duration and dose of CS therapy was 5.6+/-6.6 years and 16.9+/
19.7 g. CS therapy was significantly correlated to a decrease in FN or LSBMD: OR
= 1.95, 95% confidence interval (CI, 1.29-2.97) and OR = 3.19 (CI, 1.80-5.66),
respectively. The Hmean and Hmaxi were significantly lower in the cases than in
the controls: P = 0.03 and P = 0.02; OR = 1.67 (CI, 1.10-2.54) and OR = 1.75 (CI,
1.05-2.37). A similar trend was observed with Hmini but the difference did not
reach the level of statistical significance: P = 0.06, OR = 1.57 (CI, 1.05-2.37).
This study was repeated among cases and controls who had never taken HRT
(respectively, n = 40 and n = 39). The results were similar. Among patients
taking CS therapy, the presence of nontraumatic fractures was inversely related
to BMD values but not to texture parameters. These data have shown that long-term
CS therapy induces both BMD decrease and trabecular bone texture changes. The
effect of CS therapy was much stronger on BMD than on the fractal H parameter.
These results are in accordance with previous studies showing a lower effect of
CS therapy on bone microarchitecture than on bone mass. These results can be
contrasted with those observed in women with postmenopausal osteoporosis and
vertebral crush fractures in which the variations in the fractal parameters are
more significant than the BMD variations.
PMID- 10780867
TI - Effects of alendronate on bone quality and remodeling in glucocorticoid-induced
osteoporosis: a histomorphometric analysis of transiliac biopsies.
AB - Effects of alendronate (ALN) on bone quality and turnover were assessed in 88
patients (52 women and 36 men aged 22-75 years) who received long-term oral
glucocorticoid exposure. Patients were randomized to receive oral placebo or
alendronate 2.5, 5, or 10 mg/day for 1 year and stratified according to the
duration of their prior glucocorticoid treatment. Transiliac bone biopsies were
obtained for qualitative and quantitative analysis after tetracycline double
labeling at the end of 1 year of treatment. As previously reported in
glucocorticoid-induced osteoporosis, low cancellous bone volume and wall
thickness were noted in the placebo group as compared with normal values.
Alendronate treatment was not associated with any qualitative abnormalities.
Quantitative comparisons among the four treatment groups were performed after
adjustment for age, gender, and steroid exposure. Alendronate did not impair
mineralization at any dose as assessed by mineralization rate. Osteoid thickness
(O.Th) and volume (OV/BV) were significantly lower in alendronate-treated
patients, irrespective of the dose (P = 0.0003 and 0.01, respectively, for O.Th
and OV/BV); however, mineral apposition rate was not altered. As anticipated,
significant decreases of mineralizing surfaces (76% pooled alendronate group; P =
0.006), activation frequency (-72%; P = 0.004), and bone formation rate (-71%; P
= 0.005) were also noted with alendronate treatment. No significant difference
was noted between the changes observed with each dose. Absence of tetracycline
label in trabecular bone was noted in approximately 4% of biopsies in placebo and
alendronate-treated groups. Trabecular bone volume, parameters of
microarchitecture, and resorption did not differ significantly between groups. In
conclusion, alendronate treatment in patients on glucocorticoids decreased the
rate of bone turnover, but did not completely suppress bone remodeling and
maintained normal mineralization at all alendronate doses studied. Alendronate
treatment did not influence the osteoblastic activity, which is already low in
glucocorticoid-induced osteoporosis.
PMID- 10780868
TI - Differences in skeletal kinetics between vertebral and humeral bone measured by
18F-fluoride positron emission tomography in postmenopausal women.
AB - We have sought to investigate regional differences in skeletal kinetics between
lumbar vertebrae and the humerus of postmenopausal women with 18F-fluoride
positron emission tomography (PET). Twenty-six women, mean age 62 years, had
dynamic PET scans of the lumbar spine and lower humerus after the injection of
180 MBq 18F-fluoride ion. Plasma arterial input functions (IFs) were calculated
from a mean IF measured arterially from 10 women and scaled according to late
individual venous activity. Vertebral and humeral time activity curves were
measured by placing regions of interest (ROI) over lumbar vertebrae and the
humeral shaft. Using a three-compartmental model and nonlinear regression
analysis the macroconstant Ki, representing plasma clearance of fluoride to bone
mineral, and the individual rate constants K1 (related to regional skeletal blood
flow) and k2 to k4 describing transport between plasma, an extracellular fluid
compartment and a bone mineral compartment, were measured. Mean vertebral Ki
(3.47x10(-2) ml x min(-1) x ml(-1)) and K1 (1.08x10(-1) ml x min(-1) x ml(-1))
were found to be significantly greater than humeral Ki (1.64x10(-2) ml min(-1)
ml(-1); P<0.0001) and K1 (3.90x10(-2) ml x min(-1) x ml(-1); P<0.0001) but no
significant differences were found in k2, k3, and k4. These findings confirm
differences in regional skeletal kinetics between lumbar vertebrae and the lower
humerus. These observations may help increase our understanding of the regional
differences in pathophysiology and response to treatment that have been observed
in sites consisting predominantly of either trabecular or cortical bone. 18F
fluoride PET may prove to be a valuable technique in the noninvasive measurement
of regional skeletal metabolism.
PMID- 10780869
TI - Alfacalcidol inhibits bone resorption and stimulates formation in an
ovariectomized rat model of osteoporosis: distinct actions from estrogen.
AB - Although alfacalcidol has been widely used for the treatment of osteoporosis in
certain countries, its mechanism of action in bone, especially in the vitamin D
replete state, remains unclear. Here we provide histomorphometric as well as
biochemical evidence that alfacalcidol suppresses osteoclastic bone resorption in
an ovariectomized rat model of osteoporosis. Furthermore, when compared with
17beta-estradiol, a representative antiresorptive drug, it is evident that
alfacalcidol causes a dose-dependent suppression of bone resorption, and yet
maintains or even stimulates bone formation, as reflected in increases in serum
osteocalcin levels and bone formation rate at both trabecular and cortical sites.
17beta-Estradiol, which suppresses bone resorption to the same extent as
alfacalcidol, causes a parallel reduction in the biochemical and
histomorphometric markers of bone formation. As a final outcome, treatment with
alfacalcidol increases bone mineral density and improves mechanical strength more
effectively than 17beta-estradiol, with a more pronounced difference in cortical
bone. We conclude that estrogens depress bone turnover primarily by suppressing
bone resorption and, as a consequence, bone formation as well, whereas
alfacalcidol "supercouples" these processes, in that it suppresses bone
resorption while maintaining or stimulating bone formation.
PMID- 10780870
TI - Premenopausal smoking and bone density in 2015 perimenopausal women.
AB - The importance of cigarette smoking in relation to bone mass remains uncertain,
especially in younger women. In a recent meta-analysis including 10 studies in
premenopausal women no effect was seen in this age group. We used baseline data
from a large national cohort study (Danish Osteoporosis Prevention Study [DOPS])
to study the cumulated effect of pre- and perimenopausal smoking on bone mineral
density (BMD) measured shortly after the cessation of cyclic bleedings. Baseline
observations on 2015 recently menopausal women were available. Eight hundred
thirty-two women were current smokers and 285 were exsmokers. Significant
negative associations of cigarette smoking coded as current, ex-, or never
smoking were seen on bone mass in the lumbar spine (P = 0.012), femoral neck
(P<0.001), and total body (P<0.001). Quantitatively, the differences between
current smokers and never smokers were limited to 1.6, 2.9, and 1.9%,
respectively. A statistical interaction was found between smoking and fat mass,
indicating that women in the highest tertile of fat mass were unaffected by
cigarette smoking. Serum vitamin D levels and osteocalcin were inversely related
to the number of cigarettes smoked per day (r = 0.11 and P<0.001; r = 0.17 and P
= 0.04), respectively. Bone alkaline phosphatase (BALP) and urinary
hydroxyproline (U-OHP) were unaffected by current smoking. The average cumulated
effect of premenopausal smoking on bone is small but biologically significant.
Reduced body mass in smokers explains part of the negative effect on the skeleton
and a complex interaction between smoking and fat mass on the skeleton is
indicated. Serum levels of 25-hydroxyvitamin D (25-OHD) and osteocalcin are lower
in smokers, which may effect rate of bone loss.
PMID- 10780871
TI - Garlic and onions: their effect on eicosanoid metabolism and its clinical
relevance.
AB - Garlic (Allium sativum) and onion (Allium cepa) are among the oldest of all
cultivated plants. Additionally, both plants have been used as medicinal agents
for thousands of years. Both garlic and onion have been shown to have
applications as antimicrobial, antithrombotic, antitumor, hypolipidaemic,
antiarthritic and hypoglycemic agents. In recent years, extensive research has
focussed on the beneficial and medicinal properties of garlic and onions. In
particular, the use of these agents in the treatment and prevention of
cardiovascular disease and cancer is an area of considerable investigation and
interest.
PMID- 10780872
TI - Fumonisin B1 influenced the effects of arachidonic acid, prostaglandins E2 and A2
on cell cycle progression, apoptosis induction, tyrosine- and CDC2-kinase
activity in oesophageal cancer cells.
AB - In a previous study, we showed that, of a group of lipids including arachidonic
acid (AA), prostaglandins E2 (PGE2) and A2 (PGA2), PGA2 had the most marked
effect on the inhibition of cell growth, activation of tyrosine kinase activity,
lowering of the number of G1-phase cells, and induction of p53 levels in
oesophageal carcinoma (WHCO3) cells. No significant effects by the three lipids
were seen in normal monkey kidney cells. In the present study, the effects of the
inhibitor of ceramide synthesis, fumonisin B1 (FB1), a metabolite of Fusarium
verticillioides (= F. moniliforme) which is implicated in the high incidence of
oesophageal cancer, were determined on AA, PGE2 and PGA2 WHCO3 treated cells. In
the presence of FB1, the lipid-enhanced tyrosine kinase activity was lowered.
Flow cytometric and morphological studies showed that FB1 lowered the marked
apoptosis induced by especially PGA2. FB1, however, in combination with AA, PGE2
or PGA2 increased the number of G2/M cells. AA>PGE2>PGA2 alone decreased CDC2
kinase activity, but, in the presence of FB1, CDC2-kinase activity was
significantly increased. The PGA2- and AA-induced p53 levels were lowered in the
presence of FB1. We concluded that FB1 diminished the cytotoxic effects of the
lipids on oesophageal tumour cells.
PMID- 10780874
TI - A simple and efficient method for hemoglobin removal from mammalian tissue
cytosol by zinc sulfate and its application to the study of lipoxygenase.
AB - A simple and efficient method is described to remove hemoglobin (Hb) from human
term placental cytosol to study dioxygenase and co-oxidase activities of
lipoxygenase. In the untreated samples, 70%-80% of the linoleic acid-dependent
dioxygenase and co-oxidase activities were found to be associated with the pseudo
lipoxygenase activity of Hb. Zinc sulfate (0.5 mM) precipitated >97% of the Hb
present in the cytosol. The dioxygenase activity of the ZnSO4 treated cytosol
exhibited a Vmax value of 313 nmoles linoleic acid hydroperoxide formed/min/mg
protein and a K(M) of 1.4 mM for linoleic acid. The ZnSO4 treated cytosol
displayed co-oxidase activity toward benzidine, dimethoxybenzidine, guaiacol,
pyrogallol, tetramethylbenzidine and tetramethyl-p-phenylenediamine.
Nordihydroguaiaretic acid, 5,8,11-eicosatriynoic acid, butylated hydroxyanisole,
butylated hydroxytoluene and gossypol caused concentration dependent inhibition
of dioxygenase and co-oxidase activities. These results suggest ZnSO4
precipitation of Hb from cytosol does not alter the functional characteristics of
the human term placental lipoxygenase.
PMID- 10780873
TI - Effect of polyunsaturated fatty acids on dexamethasone-induced gastric mucosal
damage.
AB - BACKGROUND: Increased dietary intake of polyunsaturated fatty acids (PUFAs) is
known to be associated with a decrease in the incidence of peptic ulcer disease
possibly due to increase in the synthesis of prostaglandins. But, it is also
likely that conversion of PUFAs to PGs may not always be required for gastric
mucosal protection. Present study was designed to study the role of PUFAs in
pathobiology of steroid induce gastric damage in rats. METHODS: Wistar rats were
treated with 5 mg/kg bodyweight of dexamethasone to induce gastric mucosal
ulcers. Effects of PUFAs was studied by supplementation of Fish oil (rich in n-3
EPA and DHA) and AA rich oil. Famotidine was used as a positive control.
Generation of lipid peroxides, nitric oxide and the activity of anti-oxidant
enzymes were also studied. RESULTS: Dexamethasone induced ulceration was
associated with changes in the phospholipid fatty acid profile, levels of lipid
peroxidation products, nitric oxide and activity of anti-oxidant enzymes. The
fatty acid profile showed an increase in LA and a decrease in other PUFAs like
GLA, AA, EPA and DHA. When PUFAs were supplemented in the form of Fish oil and AA
rich oil or when the animals were treated with H2-blocker, famotidine, there was
a decrease in the incidence of ulceration in the animals associated with near
normalization of changes in the phospholipid fatty acid profile. The levels of
lipid peroxides, nitric oxide, and anti-oxidant activity also reverted to control
values. CONCLUSIONS: Dexamethasone induced gastric ulceration was prevented by
PUFAs. This is supported by the results of our earlier study where in it was
noted that in patients with DU plasma lipid peroxides, nitric oxide and
phospholipid fatty acid pattern and red cell antioxidant activity were altered
similar to those seen in dexamethasone treated group of the present study. These
abnormalities, similar to the PUFA treated groups of the present study, reverted
to normalcy following treatment of the patients with lansoprazole, a proton pump
inhibitor. Further, PUFAs are known to inhibit the growth of Helicobacter pylori
in vitro. Hence, it is concluded that PUFAs, free radicals, nitric oxide and anti
oxidants play a significant role in the pathobiology of peptic ulcer.
PMID- 10780875
TI - Antioxidant activity of selected Indian spices.
AB - Spices and vegetables possess antioxidant activity that can be applied for
preservation of lipids and reduce lipid peroxidation in biological systems. The
potential antioxidant activities of selected spices extracts (water and alcohol
1:1) were investigated on enzymatic lipid peroxidation. Water and alcoholic
extract (1:1) of commonly used spices (garlic, ginger, onion, mint, cloves,
cinnamon and pepper) dose-dependently inhibited oxidation of fatty acid, linoleic
acid in presence of soybean lipoxygenase. Among the spices tested, cloves
exhibited highest while onion showed least antioxidant activity. The relative
antioxidant activities decreased in the order of cloves, cinnamon, pepper,
ginger, garlic, mint and onion. Spice mix namely ginger, onion and garlic; onion
and ginger; ginger and garlic showed cumulative inhibition of lipid peroxidation
thus exhibiting their synergistic antioxidant activity. The antioxidant activity
of spice extracts were retained even after boiling for 30 min at 100 degrees C,
indicating that the spice constituents were resistant to thermal denaturation.
The antioxidant activity of these dietary spices suggest that in addition to
imparting flavor to the food, they possess potential health benefits by
inhibiting the lipid peroxidation.
PMID- 10780876
TI - Renal synthesis of prostacyclin and thromboxane in healthy women: differential
effects of a short-term saline loading.
AB - It is accepted that the urinary excretions of the stable metabolites of
prostaglandin (PG)I2 and thromboxane(Tx) A2, 6-keto-PGF1alpha (6KPGF) and TxB2
respectively, provide an accurate estimate of both basal and stimulated renal
synthesis of their precursors. The excretory profile of these metabolites has
been evaluated in healthy women submitted to a short-term expansion in
extracellular fluid volume. Salt retention (SR group, n=6) was induced by
physiological saline (0.9% NaCl) i.v. infusions (2 L per day) over a period of 2
days. On the third day the increase in body weight was 0.92 +/- 0.27 kg (P<0.05).
The results of the study have been compared to those previously obtained in
normal balance of sodium and potassium (N group, n=20) and in induced salt
depletion (SD group, n=14). A common study protocol was used. Basal values of
plasma renin activity (PRA) and urinary aldosterone excretion were determined.
Renal functional exploration [clearance (cl.) method] was performed during
hypotonic polyuria (induced by oral water load) and subsequent moderate
antidiuresis (induced by low-dose infusion of an antidiuretic hormone analogue).
Urinary 6KPGF and TxB2 concentrations were estimated by RIA method and their
urinary excretions were determined at both high and low urinary flow rates. The
linear regressions of the urinary metabolite excretions vs. urinary flow rate
were estimated by using the data obtained in both hypotonic polyuria and
antidiuresis. Salt retention (SR vs. N group) was effective in decreasing the
basal values of plasma renin activity and urinary aldosterone excretion.
Moreover, during hypotonic polyuria it was effective in increasing the absolute
and fractional excretions of sodium and chloride, in the absence of significant
variations in mean arterial pressure and creatinine cl. Regarding urinary
prostanoid excretions the following results were obtained. 1. Comparative data
for hypotonic polyuria. In the SR vs. N group, the urinary excretion of 6KPGF was
significantly higher, whereas that of TxB2 was not significantly different. In
the SR vs. SD group, the urinary excretion of 6KPGF was not significantly
different, whereas that of TxB2 was significantly lower. 2. Comparative data for
the regression lines of the urinary prostanoid excretions vs. diuresis. In the SR
vs. N group, the regression line slope for 6KPGF excretion was significantly
higher, whereas that for TxB2 excretion was not significantly different. In the
SR vs. SD group, the regression line slope for 6KPGF excretion was not
significantly different, whereas that for TxB2 excretion was significantly lower.
3. Correlative data in the SR group during hypotonic polyuria. The plasma
chloride concentration was positively correlated with urinary flow rate, absolute
and fractional chloride excretions, and 6KPGF excretion but not with TxB2
excretion. In conclusion, functionally effective salt retention in healthy women
induces a selective stimulation of renal synthesis of prostacyclin, unlike salt
depletion, in which the synthesis of both PGI2 and TxA2 is upregulated.
PMID- 10780877
TI - Peroxisome proliferator activated receptor-gamma (PPAR-gamma) mediates the action
of gamma linolenic acid in breast cancer cells.
AB - Gamma linolenic acid (GLA) is a polyunsaturated fatty acid, which induces
cytotoxicity and regulates cell adhesion in cancer cells. The molecular mechanism
of these actions is not clear. We have shown that GLA acts via peroxisome
proliferator activated receptors (PPARs), by stimulating their phosphorylation
and translocation to the nucleus. Removing PPAR gamma with antisense oligos
abolished the effect of GLA on the expression of adhesion molecules and tumour
suppressor genes, whereas removal of PPAR alpha had no effect. Tissues from
patients with breast cancer showed a reduction of expression of both PPARs in
cancer tissues, as compared with normal. Thus, PPAR gamma serves as the receptor
for GLA in the regulation of gene expression in breast cancer cells.
PMID- 10780878
TI - Gamma-linolenic acid provides additional protection against ventricular
fibrillation in aged rats fed linoleic acid rich diets.
AB - Ligation of the coronary artery in rats produces severe ventricular fibrillation
(VF) and malignant cardiac arrhythmia. Mortality increases with the age of the
animal. Diets rich in saturated fatty acids (SF) but low in linoleic acid (LA)
increase, but diets high in LA and low in SF decrease the severity of VF and
mortality in older animals. The effects of an LA enriched diet can be blocked by
inhibition of cyclooxygenase suggesting that conversion of LA to eicosanoids is
central to the development of VF. Conversion of LA to gamma-linolenic acid (GLA)
via delta-6 desaturase is the first step in the process. The activity of delta-6
desaturase declines with age. Thus inclusion of GLA in the diet of older animals
may provide an additional benefit over LA alone. Dietary supplements of evening
primrose oil (EPO) to one year old rats reduced ischaemic VF more than a
supplement of sunflower seed oil (SSO) without GLA. Substitution of borage oil
(more GLA than EPO but less LA than either EPO or SSO) was without additional
benefit.
PMID- 10780879
TI - Soft tissue sarcomas and p53 mutations.
PMID- 10780880
TI - Curcumin is an in vivo inhibitor of angiogenesis.
AB - BACKGROUND: Curcumin is a small-molecular-weight compound that is isolated from
the commonly used spice turmeric. In animal models, curcumin and its derivatives
have been shown to inhibit the progression of chemically induced colon and skin
cancers. The genetic changes in carcinogenesis in these organs involve different
genes, but curcumin is effective in preventing carcinogenesis in both organs. A
possible explanation for this finding is that curcumin may inhibit angiogenesis.
MATERIALS AND METHODS: Curcumin was tested for its ability to inhibit the
proliferation of primary endothelial cells in the presence and absence of basic
fibroblast growth factor (bFGF), as well as its ability to inhibit proliferation
of an immortalized endothelial cell line. Curcumin and its derivatives were
subsequently tested for their ability to inhibit bFGF-induced corneal
neovascularization in the mouse cornea. Finally, curcumin was tested for its
ability to inhibit phorbol ester-stimulated vascular endothelial growth factor
(VEGF) mRNA production. RESULTS: Curcumin effectively inhibited endothelial cell
proliferation in a dose-dependent manner. Curcumin and its derivatives
demonstrated significant inhibition of bFGF-mediated corneal neovascularization
in the mouse. Curcumin had no effect on phorbol ester-stimulated VEGF production.
CONCLUSIONS: These results indicate that curcumin has direct antiangiogenic
activity in vitro and in vivo. The activity of curcumin in inhibiting
carcinogenesis in diverse organs such as the skin and colon may be mediated in
part through angiogenesis inhibition.
PMID- 10780881
TI - Specific killing of HIV-infected lymphocytes by a recombinant immunotoxin
directed against the HIV-1 envelope glycoprotein.
AB - BACKGROUND: 3B3 is a high-affinity anti-gp120 antibody that neutralizes a wide
range of primary and laboratory isolates of HIV-1. The parental antibody was
isolated from a combinatorial phage display library constructed from bone marrow
RNA of an HIV-infected individual. We have generated a highly active immunotoxin
using the 3B3 single-chain Fv (scFv) which can specifically kill lymphocytes
infected by HIV-1. MATERIALS AND METHODS: We used recombinant DNA technology to
clone the Fv fragment of 3B3 and produce a single-chain Fv (scFv). 3B3 scFv was
then fused to a truncated version of Pseudomonas exotoxin A (PE38), giving rise
to a recombinant immunotoxin 3B3(Fv)-PE38 that was expressed in E. coli and
purified to near homogeneity. RESULTS: 3B3(Fv)-PE38 binds with the same affinity
as the parental Fab antibody to the MN strain of gp120. The immunotoxin
specifically kills a gp120-expressing transfected cell line and a chronically HIV
infected lymphocytic cell line. The immunotoxin is very stable at 37 degrees C,
retaining 80% of its original activity after 24 hr. CONCLUSIONS: Potent
immunotoxins such as 3B3(Fv)-PE38 could be utilized in combination with multidrug
cocktails that limit viral replication to help reduce viral reservoirs in
patients with AIDS.
PMID- 10780882
TI - Expression pattern of the Ets-related transcription factor Elf-1.
AB - Members of the Ets family of winged helix-loop-helix transcription factors play
important roles in the development and function of multiple mammalian cell
lineages. Elf-1 is an Ets-related transcription factor that is expressed at high
levels in T cells and is known to regulate the expression of several T cell
genes, including the granulocyte-macrophage colony stimulating factor (GM-CSF)
gene, the interleukin-2 receptor alpha subunit (IL-2Ralpha) gene, and the CD4
gene. In the studies described in this report, we have characterized the pattern
of expression of Elf-1 in the developing mouse embryo and in adult mouse tissues
as well as in multiple immortalized human and murine cell lines. Elf-1 is
expressed at high levels throughout thymocyte development, with equivalent levels
of Elf-1 expression seen in all subsets of maturing thymocytes and T cells.
Somewhat surprisingly, however, Elf-1 is also expressed at high levels in
epithelial cells lining the oral cavity, the lung, the CNS, and the
gastrointestinal and urinary tracts as well as in the skin of the developing
mouse embryo and at lower levels in the adult mouse testis and liver. Western
blot analyses of a large number of immortalized cell lines demonstrated high
level Elf-1 expression in T and B lymphocyte and macrophage cell lines as well as
in two prostate carcinoma cell lines. Low-level expression was observed in
fibroblasts, embryonic stem cells, and myoblasts. Taken together, our data
suggest that in addition to its role in regulating T cell development and
function, Elf-1 may regulate gene expression in the B cell and myelomonocytic
lineages, as well as in multiple epithelial cell types during murine embryonic
development.
PMID- 10780883
TI - Kaposi's sarcoma-associated herpesvirus viral interferon regulatory factor
confers resistance to the antiproliferative effect of interferon-alpha.
AB - BACKGROUND: Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a 442 amino
acid polypeptide-designated viral interferon regulatory factor (vIRF) that
displays homology to members of the interferon regulatory factor (IRF) family
that bind to consensus interferon sequences and transactivate cellular genes that
can modulate growth inhibition. Studies were conducted to determine whether vIRF
affects the growth suppression mediated by interferon-alpha (IFN-alpha) in a
human B lymphocyte cell line. MATERIALS AND METHODS: The human B lymphocyte cell
line Daudi, which is sensitive to the antiproliferative effects of IFN-alpha, was
stably transfected to express vIRF, and the proliferative response of vIRF
expressing cells to IFN-alpha was compared with controls. The effect of vIRF on
IRF- 1 transactivation was analyzed by co-transfection of an IFN-alpha-responsive
chloramphenicol acetyltransferase reporter and expression plasmids encoding IRF-1
and vIRF. Electrophoretic mobility shift assays were conducted to determine
whether vIRF interferes with the DNA binding activity of IRF-1. RESULTS: Daudi
human B lymphocyte cells expressing vIRF were resistant to the antiproliferative
effects of IFN-alpha, whereas wild-type Daudi or Daudi cells transformed with
vector DNA were growth inhibited by IFN-alpha. The activation of an interferon
responsive reporter by IFN-alpha or IRF-1 was repressed by expression of vIRF.
IRF-1 DNA binding activity was unaffected by vIRF, and vIRF alone did not bind to
the interferon consensus sequence. CONCLUSIONS: These studies revealed that vIRF
functions to inhibit interferon-mediated growth control of a human B lymphocyte
cell line by targeting IRF-1 transactivation of interferon-inducible genes. Since
KSHV is a B lymphotropic herpesvirus associated with two forms of B lymphocyte
neoplasms, these effects of vIRF likely contribute to B cell oncogenesis
associated with KSHV infection.
PMID- 10780884
TI - Reversal of established rat crescentic glomerulonephritis by blockade of
macrophage migration inhibitory factor (MIF): potential role of MIF in regulating
glucocorticoid production.
AB - Macrophage migration inhibitory factor (MIF) is a potent pro-inflammatory
cytokine that also counter-regulates glucocorticoid action. We investigated
whether immunoneutralization of MIF could reverse established experimental
crescentic glomerulonephritis and if this treatment could modulate endogenous
glucocorticoid levels. Accelerated anti-GBM glomerulonephritis was induced in six
littermate pairs of rats. Once crescentic disease was established on day 7, one
animal in each pair was given a daily injection of neutralizing anti-MIF antibody
(Ab) or irrelevant isotype control Ab for 14 days and then killed on day 21. In
addition, a group of 6 animals was killed on day 7 of disease without any
treatment. Animals receiving the control Ab exhibited a rapidly progressive
glomerulonephritis with severe renal injury (proteinuria), loss of renal function
(creatinine clearance), anemia, and marked histologic damage (including
glomerular crescent formation), compared with animals killed on day 7 without
treatment. In contrast, anti-MIF Ab treatment partially reversed the disease by
restoring normal renal function and reducing histological damage compared with
untreated animals killed on day 7 (p < 0.05). Interestingly, anti-MIF Ab
treatment also prevented severe anemia (p < 0.05). Reversal of disease was
associated with a significant reduction in leukocyte infiltration and activation
and renal interleukin-1 (IL-1) production. Importantly, anti-MIF Ab treatment
caused a significant increase in endogenous serum corticosterone levels, which
correlated with the reversal of disease parameters. In conclusion, this study has
demonstrated that blocking MIF activity can partially reverse established
crescentic glomerulonephritis and suggests that MIF operates by both enhancing
the cellular immune response and suppressing the endogenous anti-inflammatory
glucocorticoid response.
PMID- 10780885
TI - Moulds, mites and childhood asthma.
PMID- 10780886
TI - Beta-adrenoceptor agonists in bronchial asthma: role of k+-channel opening in
mediating their bronchodilator effects.
PMID- 10780887
TI - Importance of house dust mite and Alternaria allergens in childhood asthma: an
epidemiological study in two climatic regions of Australia.
AB - The relation of house dust mite allergen levels to asthma and allergy was
examined in two population samples of children aged 8-11 years in northern New
South Wales. We studied 805 children in Lismore (a hot, humid, coastal region)
and 770 in Moree/Narrabri (a hot, dry inland region). Respiratory symptoms were
measured by questionnaire, bronchial hyperresponsiveness (BHR) by histamine
inhalation test, and allergy by skin-prick tests. Current asthma was defined as
the presence of both wheeze in last 12 months and BHR. Der p I levels were
measured in dust from the bed and floors in the homes of 57 randomly selected
children in the coastal region and of 74 inland children. Der p I levels were
significantly higher by the coast (83.0 vs 11.2 microg/g, P < 0.001). House dust
mite sensitivity was of similar prevalence in both regions (28.6 vs 26.4%, n.s.)
but Alternaria sensitivity was higher inland (4.0 vs 15.2% P<0.001). Bronchial
responsiveness was more severe in coastal children sensitized to house dust mites
and in inland children who were sensitized to Alternaria. The adjusted odds
ratios for current asthma in children sensitized to house dust mites were 21.3
(95% CI 10.5, 43.2) by the coast and 2.7 (95% CI 1.3, 5.4) inland, and in
children sensitized to Alternaria were 3.4 (95% CI 1.3, 9.1) in the coastal
region and 5.6 (95% CI 3.1, 10.1 inland. These studies suggest that high house
dust mite allergen levels in a humid, subtropical region act to significantly
increase bronchial responsiveness in sensitized children, and that Alternaria
allergens have a similar but less potent action in a dry, rural region.
PMID- 10780889
TI - Familial occurrence of atopic disease: genetic versus environmental factors.
AB - Cumulative life prevalence of atopic disease (any of reported symptoms of
asthma/wheezy bronchitis, allergic rhinitis, eczema and urticaria) was studied by
means of a questionnaire in 19814 (7-, 10- and 14-year-old) Swedish school
children and their parents. Maternal history was found to be twice as common as
paternal history. The children of affected mothers contracted atopic disease in
the same proportion as the children of affected fathers yielding twice as many
affected children with affected mothers than with affected fathers. The strongest
parental influence on childhood disease was seen for multiple symptoms and for
congruent symptoms with both parents. The number of children with both parents
affected was 1.6 times larger than expected. A possible dose-response effect in
polygenic inheritance is discussed as well as assumed impact of environmental
factors with a tendency to familial clustering.
PMID- 10780888
TI - Early neutrophil but not eosinophil or platelet recruitment to the lungs of
allergic horses following antigen exposure.
AB - Previous studies have shown that bronchoalveolar lavage fluid from horses with
allergic respiratory disease and showing clinical symptoms contains increased
numbers of neutrophils. In some cases, the eosinophil count is also increased. In
this study the time course of changes in lung function and the accumulation of
radiolabelled leucocytes and platelets in the lungs of allergic and normal horses
has been examined during a 7 hr allergen exposure. Antigen challenge had no
effect on pleural pressure or the distribution of radiolabelled neutrophils,
eosinophils or platelets in normal horses. In contrast, in 6/8 allergic horses,
there was an increase in pleural pressure and neutrophil accumulation in the
lungs, both of which were evident after 4-5 hr. However, during the 7 hr
challenge period radiolabelled eosinophils were detected in the lungs of only 1/6
horses exhibiting an increase in pleural pressure and in 1/7 horses that failed
to show a change in airway function despite a clinical history of allergic
respiratory disease. Antigen challenge did not alter the distribution of
radiolabelled platelets in the five allergic horses tested. These results
demonstrate that increased pleural pressure is not accompanied by eosinophil or
platelet accumulation in the lungs of horses with allergic respiratory disease
following exposure to antigen. However, changes in airway function can be
associated with neutrophil accumulation but can also take place in the absence of
this cell recruitment. This raises the possibility that the presence of
neutrophils in the lung is not a prerequisite for changes in lung function.
PMID- 10780890
TI - Optimized preparation of Aspergillus fumigatus extracts for allergy diagnosis.
AB - Extracts of Aspergillus fumigatus are required for the measurement of specific
antibodies that are important indices in the diagnosis of allergic
bronchopulmonary aspergillosis (ABPA). This study investigated the effect of
different culture conditions on the production and release of antigenic and
allergenic proteins of A. fumigatus. Increasing the incubation temperature from
25 degrees C to 37 degrees C altered the production of proteins by the mycelium
which resulted in the release of a greater number of proteins that reacted with
precipitating antibodies. Static sporulating cultures produced a much wider
antigenic spectrum than shake cultures although the number of precipitating
proteins (5 and 3 respectively) and major IgE binding proteins (5 and 3
respectively) was not greatly altered. The widest range of proteins bound by
precipitating antibody or IgE from ABPA serum were released into the culture
filtrate during 28 day static incubation at 37 degrees C. The resultant extract
proved useful for screening patients for specific IgE and will provide a starting
material for the identification of individual antigens or allergens.
PMID- 10780891
TI - Inhibition of bronchial hyperresponsiveness to histamine induced by intravenous
administration of leukotriene C4 by novel thromboxane A2 receptor antagonists ONO
NT-126 and ONO-8809 in guinea-pigs.
AB - We studied the effect of intravenous administration of leukotriene (LT) C4 on
bronchial responsiveness to histamine and airway wall thickening in guinea-pigs.
Guinea-pigs were killed and the lungs were fixed in formalin. Slides from
paraffin-embedded sections of the lungs were stained and the airways that were
cut in transverse sections were measured by tracing enlarged images using a
digitizer. Moreover, airway resistance (Raw) was determined by a pulmonary
mechanics analyser and we calculated two indices, an index of airway wall
thickening and the one of airway hyperresponsiveness to histamine, from changes
of baseline-Raw and peak-Raw following intravenous administration of histamine
before and after the intravenous administration of LTC4. Intravenous
administration of 3 microg/kg LTC4 for 1 hr induced an increase of the relative
thickness of the airway wall in peripheral bronchi by the histological
examination. In analysis of airway function, intravenous administration of 3
microg/kg LTC4 for 1 hr induced airway hyperresponsiveness to histamine with
airway wall thickening. Thromboxane A2 receptor antagonists ONO-NT-126 and ONO
8809 inhibited the LTC4-induced airway hyperresponsiveness to histamine in a dose
dependent manner, but not the airway wall thickening induced by LTC4, suggesting
that the effect of LTC4 on bronchial hyperresponsiveness is likely to be mediated
through TXA2.
PMID- 10780892
TI - IgG and IgA subclass antibodies against Aspergillus umbrosus in farmer's lung
disease.
AB - Fifty patients with farmer's lung disease (FL), 20 asymptomatic exposed farmers,
and 18 healthy controls were investigated for total IgG and total IgA, as well as
subclass antibody levels against Aspergillus umbrosus, the most common fungus to
which FL patients in Finland have been exposed. Enzyme-linked immunosorbent assay
(ELISA) revealed significantly elevated levels of specific total IgG and IgA
antibodies in the sera of patients during the acute phase of the disease. Both
IgG1 and IgG2 subclass antibodies and both IgA1 and IgA2 subclass antibodies were
significantly associated with the disease. The antibody levels decreased during
the first 3 months, when mould exposure was avoided and when an oral 6-week
steroid treatment was administered. During the next 12 month follow-up, the mean
antibody levels continued to decrease, even though re-exposure might have
occurred. The results (with sensitivity 94% and specificity 95%) imply that in
addition to the measurement of A. umbrosus-specific IgG, determination of both A.
umbrosus-specific IgG1 and IgA might also be useful in the serodiagnosis of acute
stage of FL.
PMID- 10780893
TI - A retrospective study on the safety of immunotherapy in pregnancy.
AB - Eighty-one Indian patients received immunotherapy for allergic diseases during
109 pregnancies. Their allergy clinic records were analysed retrospectively and
this revealed an incidence similar to or less than the general population with
regard to abortion, perinatal mortality, prematurity, toxaemia and congenital
malformation. A control group of 60 contemporary Indian patients (82 pregnancies)
who refused immunotherapy were also analysed retrospectively and this revealed a
higher incidence of abortion, prematurity and toxaemia as compared with those
treated with immunotherapy. It is concluded that immunotherapy for allergic
diseases is safe in pregnancy. Immunotherapy is safe even when it is initiated
for the first time in a pregnant patient, an aspect not reported in any study
until now.
PMID- 10780894
TI - Lack of role for mononuclear cell-derived histamine releasing factors in
occupational asthma due to western red cedar.
AB - Occupational asthma due to Western Red Cedar (WRCA) is attributed to
sensitization to plicatic acid (PA), but does not appear to be dependent on PA
specific IgE antibodies. Exposure to PA induces histamine release in vivo and in
vitro, so if IgE is not important, other mechanisms of histamine release must
presumably operate in WRCA. To explore the possible role of histamine-releasing
factors in WRCA, peripheral blood mononuclear cells were obtained and cultured
with PA, PA-albumin conjugate plicatic acid-human serum albumin (PA-HSA), grass
pollen or Concanavalin A using a standard histamine releasing factor (HRF)
generation protocol. Supernatants were dialysed to remove endogenous histamine
and then assayed for histamine releasing activity using human basophils as
targets and a Con A-induced bulk supernatant as an internal HRF standard. In
contrast to some previous reports, spontaneous HRF release from the peripheral
blood mononuclear cells (PBMC) of WRCA patients (n=9) and atopic asthmatic
subjects (n=5) was not elevated compared with the non-asthmatic controls (n=11;
five atopic and six non-atopic). Both PA and PA-HSA induced the production of
small amounts of HRF by PBMC of WRCA patients, but a similar degree of HRF
generation was also observed in PBMC from the atopic asthmatic, atopic
nonasthmatic, and non-atopic subjects. In contrast, grass pollen induced the
production of HRF by PBMC from the subjects with positive skin tests to grass
pollen but not by PBMC of non-atopic subjects, confirming that our methods and
assay were capable of detecting antigen-specific HRF production. Since neither PA
nor PA-HSA induced significantly elevated HRF production from PBMC of WRCA
patients, it seems unlikely that PA-induced HRFs play a substantial role in the
pathogenesis of WRCA.
PMID- 10780895
TI - Study of eosinophil-endothelial adhesion, production of oxygen radicals and
release of eosinophil cationic protein by peripheral blood eosinophils of
patients with rheumatoid arthritis.
AB - Beside lymphocytes and neutrophils, eosinophils are also involved in the
inflammatory reaction in rheumatoid arthritis (RA). In this study, adhesion
characteristics of peripheral blood eosinophils were studied in 43 RA patients
and 19 controls, together with the expression of the beta2-integrin Mac-1
(CD11b/CD18). In addition, the production of oxygen radicals of isolated
peripheral blood eosinophils and serum levels of eosinophil cationic protein
(ECP) were measured in order to evaluate eosinophil activation. Adhesion of
eosinophils to unstimulated human vascular endothelium was significantly higher
in RA patients with active disease (n = 4) compared with controls (n = 14) (P <
0.005) and compared with patients with less active RA (n = 16) (P < 0.05).
Nevertheless, the expression of the adhesion molecule Mac-1 (CD11b/CD18) was not
increased in RA patients. ECP levels were higher in RA patients with active
disease (P < 0.01). Release of oxygen radicals in response to phorbol stimulation
was significantly elevated in active RA compared with controls (P < 0.05) and to
less active RA (P < 0.05). We conclude that eosinophils of RA patients,
especially those with active disease, are activated or at least primed and are
involved in the inflammatory process in RA, analogous to the inflammation in
asthma. The higher adhesion to inflamed endothelium is indicative of a higher
infiltration in the joints, where tissue damage can be caused by toxic oxygen
radicals and by granular proteins, such as ECP.
PMID- 10780896
TI - Genetic polymorphism of the beta-2 adrenergic receptor in atopic and non-atopic
subjects.
AB - To investigate a possible genetic basis for reported differences in beta-2
receptor expression in atopic subjects, DNA from 42 atopic children (22
asthmatics and 22 with allergic rhinitis) and 30 non-atopic subjects was Southern
blotted and Ban-1 restriction fragment polymorphisms (RFLPS) were studied using a
2.6 kb probe of the human beta-2 receptor gene. Two alleles 3.1 kb and 2.9 kb
were identified. Homozygotes and heterozygotes for the two alleles were found
with equal frequency in the atopic patients who had asthma and in those who had
allergic rhinitis only. The gene frequencies for the upper and lower alleles were
0.45 and 0.55 respectively. Our studies do not provide evidence for an
association between a particular polymorphic form of the human beta-2 receptor
gene and atopy.
PMID- 10780897
TI - Occupational allergy to bumble bee venom.
PMID- 10780898
TI - Cutaneous late-phase response in food-allergic children and adolescents with
atopic dermatitis.
PMID- 10780899
TI - GABA-Activated ligand gated ion channels: medicinal chemistry and molecular
biology.
PMID- 10780900
TI - A study of the relationship between biological activity and prolyl amide isomer
geometry in oxytocin using 5-tert-butylproline to augment the Cys(6)-Pro(7) amide
cis-isomer population.
AB - Three [5-t-BuPro(7)]oxytocin analogues were synthesized by substituting (2S,5R)-5
tert-butylproline for proline in oxytocin, [Mpa(1)]oxytocin, and
[dPen(1)]oxytocin. Relative to oxytocin, [5-t-BuPro(7)]oxytocin and [Mpa(1),5-t
BuPro(7)]oxytocin exhibited strongly reduced binding affinity to the receptor;
however, both peptides maintained the pharmacophore characteristics responsible
for signal transfer evoking the same maximal response as oxytocin in the single
dose procedure and exhibiting partial agonistic activity in the cumulative dose
response procedure. Although [dPen(1)]oxytocin exhibited inhibitory as well as
partial agonistic activity, [dPen(1),5-t-BuPro(7)]oxytocin exhibited only
inhibitory potency with a similar in vitro pA(2) value of 7.50 in the absence of
magnesium. In the presence of magnesium, [dPen(1), 5-t-BuPro(7)]oxytocin
exhibited stronger inhibitory potency than [dPen(1)]oxytocin and no partial
agonism. Assignment of the proton signals for the 5-tert-butylprolyl amide cis-
and trans-isomers by two-dimensional NMR experiments in water indicated that the
Cys(6)-Pro(7) peptide bond cis-isomer population was augmented relative to the
prolyl peptides and measured respectively at 35%, 33%, and 20% in the 5-tert
butylproline(7) analogues of oxytocin, [Mpa(1)]oxytocin and [dPen(1)]oxytocin.
Although caution must be taken when relating the increase in cis-isomer
population with an influence on biological activity in [5-t-BuPro(7)]oxytocin
analogues, the synthesis and evaluation of analogues 1-3 have provided additional
evidence that can be used to support the hypothesis that the prolyl amide cis
isomer may favor antagonism and the trans-isomer is necessary for agonist
activity.
PMID- 10780901
TI - 3-Alkylamino-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1,1-dioxides structurally related
to diazoxide and pinacidil as potassium channel openers acting on vascular smooth
muscle cells: design, synthesis, and pharmacological evaluation.
AB - A series of 3-alkylamino-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxides
structurally related to diazoxide and pinacidil were synthesized and tested as
possible K(ATP) channel openers on isolated pancreatic endocrine tissue as well
as on isolated vascular, intestinal, and uterine smooth muscle. In contrast to
previously described 3-alkylamino-4H-pyrido[4,3-e]-1,2,4-thiadiazine 1, 1
dioxides, most of the new compounds were found to be poorly active on B-cells but
exhibited clear vasorelaxant properties. 3-(3, 3-Dimethyl-2-butylamino)-4H
pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxide (4d) and 7-chloro-3-(3, 3-dimethyl-2
butylamino)-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxide (5d), two compounds
bearing the alkyl side chain of pinacidil, were found to be the most active
representatives of their respective series on rat aorta rings. 3
Cycloalkylalkylamino- and 3-aralkylamino-7-chloro-4H-pyrido[2,3-e]-1,2,4
thiadiazine 1, 1-dioxides also expressed myorelaxant activity on electrically
stimulated guinea pig ileum and on oxytocin-induced contractions of the rat
uterus. Further biological investigations ((86)Rb efflux measurements,
vasodilator potency on 30 and 80 mM KCl-induced contractions in the absence and
presence of glibenclamide) revealed that compounds 4d and 5d, but not compound
5f, expressed the pharmacological profile of classical K(ATP) channel openers. In
conclusion, by changing the position of the nitrogen atom in the pyridine ring,
we now have obtained a family of drugs expressing an opposite tissue selectivity.
Taken as a whole, the present findings also suggest that 3-alkylamino-4H
pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxides such as 4c, 4d, 5c, and 5d may be
considered as new examples of K(ATP) channel openers expressing a pharmacological
profile similar to that of pinacidil and diazoxide.
PMID- 10780902
TI - Improving the oral bioavailability of the iron chelator HBED by breaking the
symmetry of the intramolecular H-bond network.
AB - Physicochemical analysis and Monte Carlo simulations were used to identify
structural features which prevent oral absorption of HBED, a potent iron
chelator. In water the dominant conformations of HBED involve the hydrophobic
collapse of the two aromatic rings. These conformations are favored in polar
media because they expose the polar phenolic hydroxy groups to the solvent and
partially shield the nonpolar aromatic rings. In a less polar solvent such as
chloroform, a symmetrical H-bond network between the carboxylates and the amines
dominates the conformational space. This leads to the exposure of the phenolic
hydroxy groups to the solvent, which is unfavorable for solvation. The low
solubility of HBED in nonpolar solvents was confirmed experimentally by
determination of the partition coefficients in octanol, chloroform, and
cyclohexane and may explain the poor membrane permeability of this compound. The
high conformational stability which disfavors partitioning into phospholipids is
mainly due to the symmetrical H-bond network. Potentiometric titrations of a
monoester of HBED in MeOH/water indicate that the protonation sequence was
changed compared to that of the parent compound, suggesting that the symmetrical
H-bond network was disrupted. Conformational analysis in chloroform confirmed
that, in contrast to HBED, no symmetric interaction between the carboxylate and
the nitrogen amines is possible in the half-ester and a variety of conformations
which allow partial shielding of the polar phenolic OH groups are energetically
possible. This theoretical model predicting a better solubility of the half
esters in nonpolar solvents was supported by the large increase in the partition
coefficients in octanol, chloroform, and cyclohexane measured experimentally. The
high absorbability predicted by physicochemical and computer simulation methods
was corroborated by in vivo experiments in marmoset monkeys where the monoethyl
ester derivative of HBED was well-absorbed orally while the parent compound was
nearly ineffective in the same model.
PMID- 10780903
TI - Study on selectin blocker. 8. Lead discovery of a non-sugar antagonist using a 3D
pharmacophore model.
AB - We have developed a pharmacophore model of a ligand/E-selectin complex to screen
drug candidates for selectin blockers. In a series of sugar mimetic studies of
the E-selectin ligand, sialyl Lewis X (sLe(x)), we have already found a potent
compound, a sulfated Le(x) analogue (1), and also have proposed how compound 1
binds to E-selectin (Tsujishita, H.; Hiramatsu, Y.; Kondo, N.; Ohmoto, H.; Kondo,
H.; Kiso, M.; Hasegawa, A. J. Med. Chem. 1997, 40, 362-369). To find drug
candidates that fit into the binding pocket of E-selectin, we constructed an
original 3D-pharmacophore model from structural information of a compound 1/E
selectin complex model and screened lead compounds for selectin blockers using a
commercially available database ACD-3D. As a result, we discovered a lead
compound (2) containing good selectin inhibitory activity, and in addition, we
succeeded to preliminarily optimize it to a more active lead compound (3) with
micromolar IC(50) values, based on the 3D-pharmacophore model investigation. This
methodology using the 3D-pharmacophore model could be applicable as a pre-screen
system for selectin blockers.
PMID- 10780904
TI - Synthesis and evaluation of several new (2-chloroethyl)nitrosocarbamates as
potential anticancer agents.
AB - Seven new (2-chloroethyl)nitrosocarbamates have been synthesized as potential
anticancer alkylating agents. These compounds were designed with carrier moieties
that would either act as prodrugs or confer water solubility. All compounds were
screened in an in vitro panel of five human tumor cell lines: CAKI-1 (renal), DLD
1 (colon), NCI-H23 (lung), SK-MEL-28 (melanoma), and SNB-7 (CNS). Several agents
showed good activity with IC(50) values in the range of 1-10 microg/mL against at
least two of the cell lines. One compound, carbamic acid, (2-chloroethyl)nitroso
4-acetoxybenzyl ester (3), was selected for further study in vivo against
intraperitoneally implanted P388 murine leukemia. In addition to the
aforementioned compound, both carbamic acid, (2-chloroethyl)nitroso-4-nitrobenzyl
ester (9) and carbamic acid, (2-chloroethyl)nitroso-2,3,4, 6-tetra-O-acetyl-1
alpha,beta-D-glucopyranose ester (24) were evaluated against subcutaneously
implanted M5076 murine sarcoma in mice. None of these compounds were active in
vivo.
PMID- 10780905
TI - Synthesis and in vitro evaluation of novel morpholinyl- and
methylpiperazinylacyloxyalkyl prodrugs of 2-(6-methoxy-2-naphthyl)propionic acid
(Naproxen) for topical drug delivery.
AB - Various novel morpholinyl- (3a,b) and methylpiperazinylacyloxyalkyl (3c-f) esters
of 2-(6-methoxy-2-naphthyl)propionic acid were synthesized and evaluated in vitro
for topical drug delivery as potential prodrugs of naproxen (1). Compounds 3a-f
were prepared by coupling the corresponding naproxen hydroxyalkyl ester with the
morpholinyl- or (4-methyl-1-piperazinyl)acyl acid in the presence of
dicyclohexylcarbodiimide (DCC) and 4-(dimethylamino)pyridine (DMAP) and
quantitatively hydrolyzed (t(1/2) = 1-26 min) to naproxen in human serum.
Compounds 3c-f showed higher aqueous solubility and similar lipophilicity,
determined by their octanol-buffer partition coefficients (log P(app)), at pH 5.0
when compared to naproxen. At pH 7.4 they were significantly more lipophilic than
naproxen. The best prodrug 3c led to a 4- and 1.5-fold enhancement of skin
permeation when compared to naproxen at pH 7.4 and 5.0, respectively. The present
study indicates using a methylpiperazinyl group yields prodrugs that are
partially un-ionized under neutral and slightly acidic conditions, and thus, a
desirable combination is achieved in terms of aqueous solubility and
lipophilicity. Moreover, the resulting combination of biphasic solubility and
fast enzymatic hydrolysis of the methylpiperazinylacyloxyalkyl derivatives gave
improved topical delivery of naproxen.
PMID- 10780906
TI - AMP deaminase inhibitors. 2. Initial discovery of a non-nucleotide transition
state inhibitor series.
AB - A series of N3-substituted coformycin aglycon analogues are described that
inhibit adenosine 5'-monophosphate deaminase (AMPDA) or adenosine deaminase
(ADA). The key steps involved in the preparation of these compounds are (1)
treating the sodium salt of 6, 7-dihydroimidazo[4,5-d][1,3]diazepin-8(3H)-one (4)
with an alkyl bromide or an alkyl mesylate to generate the N3-alkylated compound
5 and (2) reducing 5 with NaBH(4). Selective inhibition of AMPDA was realized
when the N3-substituent contained a carboxylic acid moiety. For example, compound
7b which has a hexanoic acid side chain inhibited AMPDA with a K(i) = 4.2 microM
and ADA with a K(i) = 280 microM. Substitution of large lipophilic groups alpha
to the carboxylate provided a moderate potency increase with maintained
selectivity as exemplified by the alpha-benzyl analogue 7j (AMPDA K(i) = 0.41
microM and ADA K(i) > 1000 microM). These compounds, as well as others described
in this series of papers, are the first compounds suitable for testing whether
selective inhibition of AMPDA can protect tissue from ischemic damage by
increasing local adenosine concentrations at the site of injury and/or by
minimizing adenylate loss.
PMID- 10780907
TI - AMP deaminase inhibitors. 3. SAR of 3-(carboxyarylalkyl)coformycin aglycon
analogues.
AB - N3-Substituted coformycin aglycon analogues with improved AMP deaminase (AMPDA)
inhibitory potency are described. Replacement of the 5-carboxypentyl substituent
in the lead AMPDA inhibitor 3-(5-carboxypentyl)-3,6,7,8-tetrahydroimidazo[4,5
d][1, 3]diazepin-8-ol (2) described in the previous article with various
carboxyarylalkyl groups resulted in compounds with 10-100-fold improved AMPDA
inhibitory potencies. The optimal N3 substituent had m-carboxyphenyl with a two
carbon alkyl tether. For example, 3-[2-(3-carboxy-5-ethylphenyl)ethyl]-3,6,7,8
tetrahydroimidazo[4, 5-d][1,3]diazepin-8-ol (43g) inhibited human AMPDA with a
K(i) = 0. 06 microM. The compounds within the series also exhibited >1000-fold
specificity for AMPDA relative to adenosine deaminase.
PMID- 10780908
TI - AMP deaminase inhibitors. 4. Further N3-substituted coformycin aglycon analogues:
N3-alkylmalonates as ribose 5'-monophosphate mimetics.
AB - AMP deaminase (AMPDA) inhibitors increase the levels of extracellular adenosine
and preserve intracellular adenylate pools in cellular models of ATP depletion
and therefore represent a potential new class of antiischemic drugs. Recently we
reported that replacement of the ribose 5'-monophosphate component of the very
potent transition-state analogue AMPDA inhibitor coformycin monophosphate (1)
with a simple alkylcarboxy group resulted in potent, selective, and cell
penetrating AMPDA inhibitors. Here we report that replacement of this
alkylcarboxy group with an alpha-substituted alkylmalonic acid resulted in
enhanced inhibitor potency. The lead compound, 3-(5, 5-dicarboxy-6-(3
(trifluoromethyl)phenyl)-n-hexyl)coformycin aglycon (21), exhibited an AMPDA K(i)
of 0.029 microM which is (3 x 10(5))-fold lower than the K(M) for the natural
substrate AMP. A comparison of inhibitory potencies shows that the diacid
analogues with alpha-benzyl substituents are 2-10-fold more inhibitory than
similar monoacid-monoester, monoester-monoamide, or diester derivatives. Finally,
these diacid analogues are 2-40-fold more potent inhibitors than the
corresponding monocarboxylates.
PMID- 10780909
TI - Soft drugs. 12. Design, synthesis, and evaluation of soft bufuralol analogues.
AB - In the search for more potent but still short-acting beta-blockers (BB), the
methyl, ethyl, isopropyl, tert-butyl, cyclohexyl, 2-(1-adamantyl)ethyl, and
methylthiomethyl esters of the acidic inactive metabolite of bufuralol were
synthesized based on the "inactive metabolite" approach. The cleavage of the
ester bond by blood and tissue esterases rapidly deactivates these compounds,
resulting in an ultrashort duration of action. The beta-antagonist potencies and
time courses of actions of the new "soft" BBs were characterized by recording ECG
and intra-arterial blood pressure (BP) in rats. In the isoproterenol-induced
tachycardia model, while bufuralol at an iv dose of 1 mg/kg (3.8 micromol/kg)
diminished heart rate (HR) for at least 2 h, the effects of the soft drugs lasted
for only 10-30 min at equimolar dose. The inactive metabolite did not decrease HR
significantly. The first four members of this series of compounds showed the
highest beta-blocking potencies, ranging between 25% and 50% of that of
bufuralol. Next, the effects of these most active compounds on resting HR and BP
were evaluated in comparison to esmolol. Infused for 10 min at a rate of 20
micromol/kg/min, esmolol decreased HR and mean arterial pressure (MAP) by 40% and
60%, respectively. The soft drugs at doses ranging only between 2 and 4
micromol/kg/min resulted in a 20-40% decrease in HR and a 30-50% reduction in
MAP. However, the time courses of both the bradycardic and hypotensive effects of
the soft drugs were superimposable to that of esmolol, diminishing within 60 min
after the discontinuation of the infusions.
PMID- 10780910
TI - Structure-activity relationships and binding mode of styrylquinolines as potent
inhibitors of HIV-1 integrase and replication of HIV-1 in cell culture.
AB - Our prior studies showed that polyhydroxylated styrylquinolines are potent HIV-1
integrase (IN) inhibitors that block the replication of HIV-1 in cell culture at
nontoxic concentrations. To explore the mechanism of action of these inhibitors,
various novel styrylquinoline derivatives were synthesized and tested against HIV
1 IN and in cell-based assays. Regarding the in vitro experiments, the structural
requirements for biological activity are a carboxyl group at C-7, a hydroxyl
group at C-8 in the quinoline subunit, and an ancillary phenyl ring. However the
in vitro inhibitory profile tolerates deep alterations of this ring, e.g. by the
introduction of various substituents or its replacement by heteroatomic nuclei.
Regarding the ex vivo assays, the structural requirements for activity are more
stringent than for in vitro inhibition. Thus, in addition to an o-hydroxy acid
group in the quinoline, the presence of one ortho pair of substituents at C-3'
and C-4', particularly two hydroxyl groups, in the ancillary phenyl ring is
imperatively required for inhibitory potency. Starting from literature data and
the SARs developed in this work, a putative binding mode of styrylquinoline
inhibitors to HIV-1 IN was derived.
PMID- 10780911
TI - Synthesis and preliminary biological evaluations of CC-1065 analogues: effects of
different linkers and terminal amides on biological activity.
AB - CC-1065 analogues possessing a biologically active CBI functional group and amide
substituted indole and benzofuran were synthesized. The IC(50) values of
compounds 26, bearing two indoles, and 25, bearing only one indole, are 0.4 and 3
nM, respectively, against U937 leukemia cells in vitro. The IC(50) values of
compounds 28, bearing a butyramino group, and 27, bearing an acetamino group, are
0.008 and 0.4 nM, respectively, against U937 leukemia cells in vitro. Compound
29, bearing a double-bond linker, is about 4-fold more potent than 25, bearing no
double-bond linker. Compound 26 is highly potent against all cell lines tested in
the NCI in vitro screening with IC(50) values in the 0.1-5 nM range for most cell
lines. Compounds 26 and 30 are highly active against L1210 leukemia in mice.
Compound 26 is also active against B16BL6 melanoma in mice. Most importantly, 26
and 30 are not myelosuppressive at therapeutically effective doses. The mechanism
of tumor cell death is through induction of apoptosis, and is accompanied by DNA
fragmentation.
PMID- 10780912
TI - Structural studies on bioactive compounds. 32. Oxidation of tyrphostin protein
tyrosine kinase inhibitors with hypervalent iodine reagents.
AB - Hydroxylated styrenes (tyrphostins) undergo oxidation by hypervalent iodine
oxidants such as [(diacetoxy)iodo]benzene (DAIB) to give a range of products
depending on the structure of the phenolic substrate, the solvent, the oxidant
stoichiometry, and the purification strategy. Conditions have been developed to
modify the phenolic component of the tyrphostin without affecting the appended
substituted-vinyl moiety. Novel products include: unstable 2-acyloxy-2-methoxy-4
(substituted-vinyl)cyclohexadienones and their rearrangement products 2-acyloxy-4
hydroxy-3-methoxy-1-(substituted-vinyl)benzenes; phenyliodoniophenolates and
their rearrangement products iodophenoxytyrphostins; and 3,3'-dialkoxy-2,2'
dihydroxy-5, 5'-di(substituted-vinyl)biphenyls. None of these oxidation products
displayed enhanced activity in vitro in the NCI 60-cell line panel or in a panel
of human breast cancer cell lines, compared to their tyrphostin precursors. The
inhibitory activity of three representative tyrphostins (3e,n, 28) was not
modulated by aerobic/anaerobic conditions in MCF-7 and MDA 468 cells and was
independent of EGFR status in clones of ZR75B cells transfected with this
receptor. Basal growth of MCF-7 cells was unaffected by co-administration of the
growth factors EGF, TGF-alpha, IGF-I, and IGF-II, and the new agents did not
inhibit EGFR and c-erbB2 autophosphorylation in cell lysates from MDA 468 or
SkBr3 cells, respectively, suggesting that receptor tyrosine kinases are not
targets for these compounds. Growth stimulation by the tyrphostin 3n in the ER(+)
breast cell lines MCF-7, T47D, and ZR75-1 was abolished by 1 microM tamoxifen,
suggesting that this compound has estrogen agonist activity.
PMID- 10780913
TI - Antitumor polycyclic acridines. 7. Synthesis and biological properties of DNA
affinic tetra- and pentacyclic acridines.
AB - New synthetic routes to a series of tetra- and pentacyclic acridines related in
structure to marine natural products are reported. The novel water-soluble agent
dihydroindolizino[7,6,5-kl]acridinium chloride 14 has inhibitory activity in a
panel of non-small-cell lung and breast tumor cell lines exceeding that of m
AMSA. The salt inhibited the release of minicircle products of kDNA confirming
that disorganization of topoisomerase II partly underlies the activity of the
compound. COMPARE analysis of the NCI mean graph profile of compound 14 at the
GI(50) level corroborates this conclusion with Pearson correlation coefficients
(>0.6) to clinical agents of the topoisomerase II class: however, this
correlation was not seen at the LC(50) level. The inhibitory action of 14 on
Saccharomyces cerevisiae transfected with human topoisomerase II isoforms showed
a 3-fold selectivity against the IIalpha isoform over the IIbeta isoform. Unlike
m-AMSA, 14 is not susceptible to P-glycoprotein-mediated drug efflux and retains
activity in lung cells with derived resistance to the topoisomerase II inhibitor
etoposide.
PMID- 10780914
TI - Binding of norbinaltorphimine (norBNI) congeners to wild-type and mutant mu and
kappa opioid receptors: molecular recognition loci for the pharmacophore and
address components of kappa antagonists.
AB - Molecular modifications of both the kappa opioid antagonist norbinaltorphimine
(norBNI, 1) and the kappa receptor have provided evidence that the selectivity of
this ligand is conferred through ionic interaction if its N17' protonated amine
group (an "address") with a nonconserved acidic residue (Glu297) on the kappa
receptor. In the present study, we have examined the effect of structural
modifications on the affinity of norBNI analogues for wild-type and mutant kappa
and mu opioid receptors expressed in COS-7 cells. Compounds 2, 3, and 7, which
have an antagonist pharmacophore and basic N17' group in common with norBNI,
retained high affinity for the wild-type kappa but exhibited greatly reduced
affinity for mutant kappa receptors (E297K and E297A). Modification of the
phenolic or N-substituent groups of the antagonist pharmacophore (4 and 5) or
removal of basicity at the address N17' center (6) led to greatly reduced
affinity for the wild-type and mutant receptors. The reduced affinity upon
modification of the kappa receptor is consistent with the ionic interaction of
the protonated N17' group of kappa antagonists (1-3, 7) with the carboxylate
group of E297 at the top of TM6. This was supported by the greatly enhanced
affinity of compounds 1-3 for the mutant mu receptor (K303E), as compared to the
wild-type mu receptor, given that residue K303 occupies a position equivalent to
that of E297 in the kappa receptor. In view of the high degree of homology of the
seven TM domains of the kappa and mu opioid receptors, it is suggested that the
antagonist pharmacophore is bound within this highly conserved region of the
kappa or mutant mu receptor and that an anionic residue at the top of TM6 (E297
or K303E, respectively) provides additional binding affinity.
PMID- 10780915
TI - Synthesis and evaluation of tryprostatin B and demethoxyfumitremorgin C
analogues.
AB - Tryprostatin B and demethoxyfumitremorgin C are fungal inhibitors of mammalian
cell cycle progression at the G(2)/M transition. N-Alkyl derivatives of the L-Trp
L-Pro diketopiperazine were prepared as analogues of tryprostatin B, and two of
these were more active than the natural product. A second series of cis- and
trans-tetrahydro-beta-carbolines annulated to a diketopiperazine were prepared as
analogues of demethoxyfumitremorgin C. The nature of the alkyl substituent, as
well as its cis or trans relationship in the tetrahydro-beta-carboline ring, was
found to have a significant effect on cytotoxic activity. Small cis-alkyl
substituents fall into the demethoxyfumitremorgin C family, whereas bulky benzyl
trans compounds appear to act via a different mechanism of action.
PMID- 10780916
TI - Structure-activity studies for a novel series of tricyclic substituted
hexahydrobenz[e]isoindole alpha(1A) adrenoceptor antagonists as potential agents
for the symptomatic treatment of benign prostatic hyperplasia (BPH).
AB - In search of a uroselective agent that exhibits a high level of selectivity for
the alpha(1A) receptor, a novel series of tricyclic hexahydrobenz[e]isoindoles
was synthesized. A generic pharmacophoric model was developed requiring the
presence of a basic amine core and a fused heterocyclic side chain separated by
an alkyl chain. It was shown that the 6-OMe substitution with R, R
stereochemistry of the ring junction of the benz[e]isoindole and a two-carbon
spacer chain were optimal. In contrast to the highly specific requirements for
the benz[e]isoindole portion and linker chain, a wide variety of tricyclic fused
heterocyclic attachments were tolerated with retention of potency and
selectivity. In vitro functional assays for the alpha(1) adrenoceptor subtypes
were used to further characterize these compounds, and in vivo models of vascular
vs prostatic tone were used to assess uroselectivity.
PMID- 10780917
TI - Synthesis, spectroscopy, and cytotoxicity of glycosylated acetogenin derivatives
as promising molecules for cancer therapy.
AB - Several glycosyl derivatives of squamocin (1) have been synthesized by
glycosylation under Lewis acid catalysis with two different 1-O-acetyl sugars.
Separation of these compounds has been achieved by HPLC and centrifugal partition
chromatography (CPC). A detailed NMR, ESIMS, and LSIMS study allowed complete
structural elucidations. The cytotoxic activity of the glycosyl derivatives was
investigated and compared with that of squamocin and dihydrosquamocin against
human epidermoid carcinoma cells (KB), African green monkey (Cercopithecus
aethiops) kidney epithelial cells (VERO), and mouse lymphocytic leukemia cells
(L1210). The antiproliferative effects of some derivatives were studied on cell
cycles in mouse lymphocytic leukemia cells (L1210).
PMID- 10780918
TI - Syntheses of (R)- and (S)-2- and 6-fluoronorepinephrine and (R)- and (S)-2- and 6
fluoroepinephrine: effect of stereochemistry on fluorine-induced adrenergic
selectivities.
AB - Several routes to the enantiomers of fluoronorepinephrines (1) and
fluoroepinephrines (2) were explored. A catalytic enantioselective
oxazaborolidine reduction and a chiral (salen)Ti(IV) catalyzed asymmetric
synthesis of silyl cyanohydrins proved efficacious in the key stereo-defining
steps of two respective routes. Binding studies of the catecholamines with
alpha(1)-, alpha(2)-, beta(1)-, and beta(2)-adrenergic receptors were examined.
The assays confirmed that fluorine substitution had marked effects on the
affinity of (R)-norepinephrine and (R)-epinephrine for adrenergic receptors,
depending on the position of substitution. Thus, a fluoro substituent at the 2
position of (R)-norepinephrine and (R)-epinephrine reduced activity at both
alpha(1)- and alpha(2)-receptors and enhanced activity at beta(1)- and beta(2)
receptors, while fluorination at the 6-position reduced activity at the beta(1)-
and beta(2)-receptors. The effects of fluorine substitution on the S-isomers were
less predictable.
PMID- 10780919
TI - Analogues of the potent nonpolyglutamatable antifolate N(alpha)-(4-amino-4
deoxypteroyl)-N(delta)-hemiphthaloyl-L-ornithine (PT523) with modifications in
the side chain, p-aminobenzoyl moiety, or 9,10-bridge: synthesis and in vitro
antitumor activity.
AB - Seven N(alpha)-(4-amino-4-deoxypteroyl)-N(delta)-hemiphthaloyl-L-o rnithine (2,
PT523) analogues were synthesized by modifications of the literature synthesis of
the corresponding AMT (1) analogues and were tested as inhibitors of tumor cell
growth. In growth assays against cultured CCRF-CEM human leukemic cells exposed
to drug for 72 h, the IC(50) values of analogues in which N(10) was replaced by
CH(2) and CHMe were found to be 0.55 +/- 0.07 and 0.63 +/- 0.08 nM, and thus
these analogues are more potent than 1 (IC(50) = 4.4 +/- 1.0 nM) or 2 (IC(50) =
1.5 +/- 0.39 nM). The 10-ethyl-10-deaza analogue of 2 (IC(50) = 1.2 +/- 0.25 nM)
was not statistically different from 2 but was more potent than edatrexate, the
10-ethyl-10-deaza analogue of 1, which had an IC(50) of 3.3 +/- 0.36 nM. In
contrast, the analogue of 2 with both an ethyl and a CO(2)Me group at the 10
position had an IC(50) of 54 +/- 4.9 nM, showing this modification to be
unfavorable. The 4-amino-1-naphthoic acid analogue of 2 had an IC(50) of 1.2 +/-
0.22 nM, indicating that replacement of the p-aminobenzoic acid (pABA) moiety
does not diminish cytotoxicity. The analogues in which the (CH(2))(3) side chain
was replaced by slightly longer CH(2)SCH(2) and (CH(2))(2)SCH(2) groups gave
IC(50) values of 4.4 +/- 1.1 and 5.0 +/- 0.56 nM and thus were somewhat less
potent than the parent molecule. However the analogues in which the aromatic COOH
group was at the meta and para positions of the phthaloyl ring had IC(50) values
of 7.5 +/- 0.47 and 55 +/- 0.07 nM, confirming the low potency we had previously
observed with these compounds against other cell lines. Overall, the results in
this study support the conclusion that, while the position of the phthaloyl COOH
group and the length of the amino acid side chain in 2 are important determinants
of cytotoxic potency, changes in the pABA region and 9, 10-bridge are well
tolerated and can even increase potency.
PMID- 10780920
TI - Synthesis and antimalarial activity of artemisinin derivatives containing an
amino group.
AB - In search of water-soluble artemisinin derivatives that are more stable than
sodium artesunate, over 30 derivatives containing an amino group (compounds 3-5)
were synthesized and tested in mice. All products tested (except 5a and 5b) are
the beta isomers. These basic compounds combined with organic acids (oxalic acid,
maleic acid, etc. ) to yield the corresponding salts. Generally, the maleates
have better solubility in water than the corresponding oxalates. The aqueous
solutions of these salts can be kept at room temperature for several weeks
without any discernible decomposition. Compounds 3f, 3h, and 3r are much more
active against P. berghei than artesunic acid by oral administration and
therefore were further tested in monkeys. However, their oral efficacies are
poorer than that of artesunic acid against P. knowlesi in rhesus monkeys. It is
interesting to note that 3f, 3h, and 3r showed much lower efficacies against P.
berghei when they were administered subcutaneously than orally.
PMID- 10780921
TI - A minimalist approach to gene mapping: locating the gene for acheiropodia, by
homozygosity analysis.
AB - Acheiropodia is an autosomal recessive disease that results in hemimelia (lack of
formation of the distal extremities). We performed a complete genome screen of
seven members of an extended pedigree that included three siblings with
acheiropodia. Homozygosity mapping was used to identify regions most likely to
harbor the gene for acheiropodia in this pedigree. In these two key regions (14p
and 7q), further genotyping of one additional affected member of this pedigree
plus seven additional unaffected siblings provided evidence, through linkage
analysis, that the 7q36 region contains the acheiropodia gene. In this region, a
maximum two-point LOD score of 3.81 (4.2 with multipoint analysis) was achieved,
and a homozygous haplotype spanning a region of 11.7 cM was seen in all affected
in this pedigree. Finally, genotypic analysis of two additional cases of
acheiropodia with no known relation to the other samples revealed homozygous
sharing of a portion of the same haplotype on 7q36, which reduces the chromosomal
location of the acheiropodia gene to an 8.6-cM region. Localization of this gene,
at the screening level, by use of data from only three affected subjects,
provides an example of how certain genes may be mapped by use of a minimal number
of affected cases.
PMID- 10780923
TI - A cytochrome c variant resistant to heme degradation by hydrogen peroxide.
AB - BACKGROUND: Cytochrome c has peroxidase-like activity and can catalyze the
oxidation of a variety of organic substrates, including aromatic, organosulfur
and lipid compounds. Like peroxidases, cytochrome c is inactivated by hydrogen
peroxide. During this inactivation the heme prosthetic group is destroyed.
RESULTS: Variants of the iso-1-cytochrome c were constructed by site-directed
mutagenesis and were found to be more stable in the presence of hydrogen peroxide
than the wild type. No heme destruction was detected in a triple variant (Tyr67-
>Phe/Asn52-->Ile/Cys102-->Thr) with the catalytic hydrogen peroxide concentration
of 1 mM, even following the loss of catalytic activity, whereas both double
variants Tyr67-->Phe/Cys102-->Thr and Asn52-->Ile/Cys102-->Thr showed a greater
rate of peroxide-induced heme destruction than observed with the wild-type
protein. CONCLUSIONS: Heme destruction and catalytic inactivation are two
independent processes. An internal water molecule (Wat166) is shown to be
important in the heme destruction process. The absence of a protein radical in
the resistant variant suggests that the protein radical is necessary in the heme
destruction process, but presumably is not involved in the reactions leading up
to the protein inactivation.
PMID- 10780922
TI - Familial juvenile hyperuricemic nephropathy: localization of the gene on
chromosome 16p11.2-and evidence for genetic heterogeneity.
AB - Familial juvenile hyperuricemic nephropathy (FJHN), is an autosomal dominant
renal disease characterized by juvenile onset of hyperuricemia, gouty arthritis,
and progressive renal failure at an early age. Using a genomewide linkage
analysis in three Czech affected families, we have identified, on chromosome
16p11.2, a locus for FJHN and have found evidence for genetic heterogeneity and
reduced penetrance of the disease. The maximum two-point LOD score calculated
with allowance for heterogeneity (HLOD) was 4.70, obtained at recombination
fraction 0, with marker D16S3036; multipoint linkage analysis yielded a maximum
HLOD score of 4.76 at the same location. Haplotype analysis defined a 10-cM
candidate region between flanking markers D16S501 and D16S3113, exhibiting
crossover events with the disease locus. The candidate interval contains several
genes expressed in the kidney, two of which-uromodulin and NADP-regulated thyroid
hormone-binding protein-represent promising candidates for further analysis.
PMID- 10780924
TI - Construction and in vitro analysis of a new bi-modular polypeptide synthetase for
synthesis of N-methylated acyl peptides.
AB - BACKGROUND: Many active peptides are synthesized by nonribosomal peptide
synthetases (NRPSs), large multimodular enzymes. Each module incorporates one
amino acid, and is composed of two domains: an activation domain that activates
the substrate amino acid and a condensation domain for peptide-bond formation.
Activation domains sometimes contain additional activities (e.g. N-methylation or
epimerization). Novel peptides can be generated by swapping domains. Exchange of
domains containing N-methylation activity has not been reported, however.
RESULTS: The actinomycin NRPS was used to investigate domain swapping. The first
two amino acids of actinomycin are threonine and valine. We replaced the valine
activation domain of module 2 with an N-methyl valine (MeVal) activation domain.
The recombinant NRPS (AcmTmVe) catalyzes the formation of threonyl-valine. In the
presence of S-adenosyl-methionine, valine was converted to MeVal but subsequent
dipeptide formation was blocked. When acyl-threonine (the natural intermediate)
was present at module 1, formation of acyl-threonine-MeVal occurred. The
epimerization domain of AcmTmVe was impaired. CONCLUSIONS: A simple activation
domain can be replaced by one with N-methylation activity. The same condensation
domain can catalyze peptide-bond formation between N-methyl and nonmethylated
amino acids. Modification of the upstream amino acid (i.e. acylation of
threonine), however, was required for condensation with MeVal. Steric hindrance
reduces chemical reactivity of N-methyl amino acids - perfect substrate
positioning may only be achieved with acylated threonine. Loss of the epimerase
activity of AcmTmVe suggests N-methyltransferase and epimerase domains, not found
together naturally, are incompatible.
PMID- 10780925
TI - Generation of a dual-labeled fluorescence biosensor for Crk-II phosphorylation
using solid-phase expressed protein ligation.
AB - BACKGROUND: The site-specific chemical modification of proteins has proved to be
extremely powerful for generating tools for the investigation of biological
processes. Although a few elegant methods exist for engineering a recombinant
protein at a unique position, these techniques cannot be easily extended to allow
several different chemical probes to be specifically introduced into a target
sequence. As such multiply labeled proteins could be used to study many
biological processes, and in particular biomolecular interactions, we decided to
investigate whether such protein reagents could be generated using an extension
of the semisynthesis technique known as expressed protein ligation. RESULTS: A
solid-phase expressed protein ligation (SPPL) technology is described that
enables large semisynthetic proteins to be assembled on a solid support by the
controlled sequential ligation of a series of recombinant and synthetic
polypeptide building blocks. This modular approach allows multiple, different
chemical modifications to be introduced site-specifically into a target protein.
This process, which is analogous to solid-phase peptide synthesis, was used to
dual-label the amino and carboxyl termini of the Crk-II adapter protein with the
fluorescence resonance energy transfer pair tetramethylrhodamine and fluorescein,
respectively. The resulting construct reports (through a fluorescence change) the
phosphorylation of Crk-II by the nonreceptor protein tyrosine kinase, c-Abl, and
was used to probe the protein-protein interactions that regulate this important
post-translational process. CONCLUSIONS: SPPL provides a powerful method for
specifically modifying proteins at multiple sites, as was demonstrated by
generating a protein-based biosensor for Crk-II phosphorylation. Such protein
derivatives are extremely useful for investigating protein function in vitro and
potentially in vivo. This modular approach should be applicable to many different
protein systems.
PMID- 10780926
TI - Biosynthetic phage display: a novel protein engineering tool combining chemical
and genetic diversity.
AB - BACKGROUND: Molecular diversity in nature is developed through a combination of
genetic and chemical elements. We have developed a method that permits selective
manipulation of both these elements in one protein engineering tool. It combines
the ability to introduce non-natural amino acids into a protein using native
chemical ligation with exhaustive targeted mutagenesis of the protein via phage
display mutagenesis. RESULTS: A fully functional biosynthetic version of the
protease inhibitor eglin c was constructed. The amino-terminal fragment (residues
8-40) was chemically synthesized with a non-natural amino acid at position 25.
The remaining carboxy-terminal fragment was expressed as a 30-residue peptide
extension of gIIIp or gVIIIp on filamentous phage in a phage-display mutagenesis
format. Native chemical ligation was used to couple the two fragments and
produced a protein that refolded to its active form. To facilitate the packing of
the introduced non-natural amino acid, residues 52 and 54 in the carboxy-terminal
fragment were fully randomized by phage-display mutagenesis. Although the
majority of the observed solutions for residues 52 and 54 were hydrophobic -
complementing the stereochemistry of the introduced non-natural amino acid - a
significant number of residues (unexpected because of stereochemical and charge
criteria) were observed in these positions. CONCLUSIONS: Peptide synthesis and
phage-display mutagenesis can be combined to produce a very powerful protein
engineering tool. The physical properties of the environment surrounding the
introduced non-natural residue can be selected for by evaluating all possible
combinations of amino acid types at a targeted set of sites using phage-display
mutagenesis.
PMID- 10780928
TI - Rapid identification of key amino-acid-DNA contacts through combinatorial peptide
synthesis.
AB - BACKGROUND: Basic helix-loop-helix (bHLH) transcription factors are characterized
by a conserved four-helix bundle that recognizes a specific hexanucleotide DNA
sequence in the major groove. Previous studies have shown that amino acids in the
basic region make base-specific contacts, whereas the HLH region is responsible
for dimerization. Structural data suggest that portions of the loop region may be
proximal to the DNA; however, the role of the loop in DNA-binding affinity and
specificity has not been investigated. RESULTS: Protein-DNA recognition by the
Drosophila bHLH transcription factor Deadpan was probed using combinatorial solid
phase peptide synthesis methods. A series of bHLH peptide libraries that modulate
amino acid content and length in the loop region was screened with DNA and
peptide affinity columns, and analyzed using matrix-assisted laser desorption
ionization mass spectrometry (MALDI-MS). A functional bHLH peptide with reduced
loop length was found, and Lys80 was unambiguously identified as the sole loop
residue critical for DNA binding. Unnatural amino acids were substituted at this
position to assess contributions of the terminal amino group and the alkyl chain
length to DNA-binding affinity and specificity. CONCLUSIONS: Using combinatorial
solid-phase peptide synthesis methods and MALDI-MS, we were able to rapidly
identify a key amino acid involved in DNA binding by a bHLH protein. Our approach
provides a powerful alternative to current recombinant DNA methods to identify
and probe the energetics of protein-DNA interactions.
PMID- 10780929
TI - Publishing in the journals of the APS: why are authors charged fees?
PMID- 10780927
TI - Dissecting cellular processes using small molecules: identification of colchicine
like, taxol-like and other small molecules that perturb mitosis.
AB - BACKGROUND: Understanding the molecular mechanisms of complex cellular processes
requires unbiased means to identify and to alter conditionally gene products that
function in a pathway of interest. Although random mutagenesis and screening
(forward genetics) provide a useful means to this end, the complexity of the
genome, long generation time and redundancy of gene function have limited their
use with mammalian systems. We sought to develop an analogous process using small
molecules to modulate conditionally the function of proteins. We hoped to
identify simultaneously small molecules that may serve as leads for the
development of therapeutically useful agents. RESULTS: We report the results of a
high-throughput, phenotype-based screen for identifying cell-permeable small
molecules that affect mitosis of mammalian cells. The predominant class of
compounds that emerged directly alters the stability of microtubules in the
mitotic spindle. Although many of these compounds show the colchicine-like
property of destabilizing microtubules, one member shows the taxol-like property
of stabilizing microtubules. Another class of compounds alters chromosome
segregation by novel mechanisms that do not involve direct interactions with
microtubules. CONCLUSIONS: The identification of structurally diverse small
molecules that affect the mammalian mitotic machinery from a large library of
synthetic compounds illustrates the use of chemical genetics in dissecting an
essential cellular pathway. This screen identified five compounds that affect
mitosis without directly targeting microtubules. Understanding the mechanism of
action of these compounds, along with future screening efforts, promises to help
elucidate the molecular mechanisms involved in chromosome segregation during
mitosis.
PMID- 10780930
TI - Role of C-peptide in human physiology.
AB - The C-peptide of proinsulin is important for the biosynthesis of insulin but has
for a long time been considered to be biologically inert. Data now indicate that
C-peptide in the nanomolar concentration range binds specifically to cell
surfaces, probably to a G protein-coupled surface receptor, with subsequent
activation of Ca(2+)-dependent intracellular signaling pathways. The association
rate constant, K(ass), for C-peptide binding to endothelial cells, renal tubular
cells, and fibroblasts is approximately 3. 10(9) M(-1). The binding is
stereospecific, and no cross-reaction is seen with insulin, proinsulin, insulin
growth factors I and II, or neuropeptide Y. C-peptide stimulates Na(+)-K(+)
ATPase and endothelial nitric oxide synthase activities. Data also indicate that
C-peptide administration is accompanied by augmented blood flow in skeletal
muscle and skin, diminished glomerular hyperfiltration, reduced urinary albumin
excretion, and improved nerve function, all in patients with type 1 diabetes who
lack C-peptide, but not in healthy subjects. The possibility exists that C
peptide replacement, together with insulin administration, may prevent the
development or retard the progression of long-term complications in type 1
diabetes.
PMID- 10780931
TI - Triiodothyronine amplifies the adrenergic stimulation of uncoupling protein
expression in rat brown adipocytes.
AB - Uncoupling protein (UCP), the mitochondrial protein specific to brown adipose
tissue, is activated transcriptionally in response to cold and adrenergic agents.
We studied the role of triiodothyronine (T(3)) on the adrenergic stimulation of
UCP mRNA expression by use of primary cultures of rat brown adipocytes. Basal UCP
mRNA levels are undetectable. Norepinephrine (NE) increases UCP mRNA during
differentiation, not during proliferation. In hypothyroid conditions, UCP mRNA
response to NE is almost absent. The presence of T(3) (0.2-20 nM) greatly
increases the adrenergic response (30-fold). The sensitivity of UCP mRNA
responses to NE is potentiated approximately 100-fold by the presence of T(3).
The effect is proportional to the dose and time of preexposure to T(3). The
increases obtained with NE and T(3) are prevented by actinomycin and
cycloheximide. T(3) greatly stabilizes UCP mRNA transcripts. The effects of
thyroxine and retinoic acid are weaker than those of T(3). In conclusion, in
cultured rat brown adipocytes, T(3) is required and both synergizes with NE to
increase UCP mRNA and stabilizes its mRNA transcripts.
PMID- 10780932
TI - Endurance training increases FFA oxidation and reduces triacylglycerol
utilization in contracting rat soleus.
AB - We examined the effects of 8 wk of intense endurance training on free fatty acid
(FFA) transporters and metabolism in resting and contracting soleus muscle using
pulse-chase procedures. Endurance training increased maximal citrate synthase
activity in red muscles (+54 to +91%; P = 0.05) but failed to increase
cytosolic fatty acid binding protein content, mRNA for fatty acyl-CoA synthase,
and the putative FFA transporters or transport of palmitic acid into giant
sarcolemmal vesicles. At rest, only triacylglycerol (TG) synthesis was
significantly increased by training (+100.9 +/- 8.7 vs. +66.6 +/- 6.7 nmol/g wet
wt; P = 0.05). Muscle contraction increased TG synthesis (+46%; P = 0.05) and
palmitate oxidation (+115%; P = 0.05) in untrained rats. Endurance training
further enhanced synthesis of monoacylglycerol (MG), diacylglycerol (DG) and TG
during contraction (+36, +69 and +71%, respectively; P = 0.05), as well as
exogenous palmitate oxidation (+41%; P = 0.05) relative to untrained rats.
Compared with those in untrained rats, TG breakdown and oxidation during
contraction were reduced after training by 49 and 30%, respectively (P = 0.05).
In conclusion, endurance training 1) increases FFA oxidation and incorporation
into endogenous lipid pools during contraction and 2) reduces the rate of
intramuscular TG utilization during contraction when exogenous FFA availability
is adequate. The enhanced FFA uptake subsequent to training appears to be
independent of altered maximal transport rates of FFA into the muscle cell.
PMID- 10780933
TI - Glucoregulatory responses to intense exercise performed in the postprandial
state.
AB - A seven- to eightfold increment in hepatic glucose production (endogenous R(a))
occurs in postabsorptive (PA) intense exercise (IE). A similar response is likely
present in the postprandial (PP) state, when most such exercise is performed,
because 1) little evidence for increased intestinal absorption of glucose during
exercise exists, and 2) intravenous glucose does not prevent it. We investigated
IE in 10 PA and 8 PP fit, lean, young males who had exercised for 15 min at >84%
maximum O(2) uptake, starting 3 h after a 412-kcal mixed meal. The meal induced a
small rise in glycemia with sustained insulin and glucagon increases. Preexercise
glucose total R(a) and utilization (R(d)) were equal and approximately 130% of
the PA level. Exercise hyperglycemia in PP was delayed and diminished and, in
early recovery, was of shorter duration and lesser magnitude (P = 0.042). Peak
catecholamine (12- to 16-fold increase) and R(a) (PP: 11.5 +/- 1.4, PA: 13.8 +/-
1.4 mg. kg(-1). min(-1)) responses did not differ, and their responses during
exercise were significantly correlated. Exercise glucagon, insulin, and glucagon
to-insulin responses were small or not significant. R(d) reached the same peak
(PP: 8.0 +/- 0.6, PA: 9.3 +/- 0.8 mg. kg(-1). min(-1)) but was greater at 20-120
min of recovery in PP (P = 0.001). Therefore, the total R(a) response to IE is
preserved despite the possibility of prior PP suppression of endogenous R(a) and
is consistent with catecholamine mediation. Post-IE hyperglycemia is reduced in
the postprandial state.
PMID- 10780934
TI - Dose-response characteristics of insulin action on glucose metabolism: a non
steady-state approach.
AB - The traditional methods for the assessment of insulin sensitivity yield only a
single index, not the whole dose-response curve information. This curve is
typically characterized by a maximally insulin-stimulated glucose clearance
(Cl(max)) and an insulin concentration at half-maximal response (EC(50)). We
developed an approach for estimating the whole dose-response curve with a single
in vivo test, based on the use of tracer glucose and exogenous insulin
administration (two steps of 20 and 200 mU x min(-1) x m(-2), 100 min each). The
effect of insulin on plasma glucose clearance was calculated from non-steady
state data by use of a circulatory model of glucose kinetics and a model of
insulin action in which glucose clearance is represented as a Michaelis-Menten
function of insulin concentration with a delay (t(1/2)). In seven nondiabetic
subjects, the model predicted adequately the tracer concentration: the model
residuals were unbiased, and their coefficient of variation was similar to the
expected measurement error (approximately 3%), indicating that the model did not
introduce significant systematic errors. Lean (n = 4) and obese (n = 3) subjects
had similar half-times for insulin action (t(1/2) = 25 +/- 9 vs. 25 +/- 8 min)
and maximal responses (Cl(max) = 705 +/- 46 vs. 668 +/- 259 ml x min(-1) x m(-2),
respectively), whereas EC(50) was 240 +/- 84 microU/ml in the lean vs. 364 +/-
229 microU/ml in the obese (P < 0.04). EC(50) and the insulin sensitivity index
(ISI, initial slope of the dose-response curve), but not Cl(max), were related to
body adiposity and fat distribution with r of 0.6-0.8 (P < 0.05). Thus, despite
the small number of study subjects, we were able to reproduce information
consistent with the literature. In addition, among the lean individuals, t(1/2)
was positively related to the ISI (r = 0.72, P < 0.02). We conclude that the test
here presented, based on a more elaborate representation of glucose kinetics and
insulin action, allows a reliable quantitation of the insulin dose-response curve
for whole body glucose utilization in a single session of relatively short
duration.
PMID- 10780935
TI - Utilization of very low density lipoprotein by rat heart: the effect of
endotoxin.
AB - The effect of endotoxin on myocardial utilization of very low density lipoprotein
(VLDL) triacylglycerol (TAG) was studied. VLDL was prepared by rat liver
perfusion and tested as substrate in the isolated working rat heart. Both liver
and heart donor rats were pretreated in vivo with endotoxin or vehicle (control).
VLDL-TAG synthesized by endotoxin-pretreated livers was assimilated and oxidized
at an increased rate by hearts compared with control VLDL-TAG, regardless of the
cardiac endotoxic status, with increased cardiac mechanical performance (cardiac
output, hydraulic work). There was no change in incorporation of labeled VLDL
lipids into myocardial tissue lipids. Lipoprotein lipase (LPL) activity was
increased in endotoxin-pretreated hearts, and after perfusion with "endotoxic"
VLDL, there was a tendency for translocation of LPL from tissue-residual to
heparin-releasable compartments, but these changes were modest. Analysis of the
VLDL composition showed that endotoxin-pretreated livers produced apolipoprotein
(apo)-B48 VLDL with decreased particle size (and hence TAG content), but apo-B100
VLDL was unchanged. Oleate content of VLDL was increased, but there was no
difference in apo-C or apo-E content. These results suggest that VLDL-TAG
produced during sepsis/endotoxinemia may be destined for utilization by the heart
as energy substrate. However, the mechanism for its increased efficacy is
uncertain.
PMID- 10780936
TI - Hyperbaric oxygen treatment attenuates cytokine induction after massive
hemorrhage.
AB - We investigated the effect of hyperbaric oxygen treatment (HBO) on cytokine
induction after hemorrhage, because hypoxia induces cytokines in vitro.
Chronically cannulated conscious rats were subjected to 40 ml/kg of hemorrhage
and resuscitated with the shed blood and twice the volume of saline either under
room air (room air group) or under 100% oxygen at 3 atmospheres absolute
(hyperbaric group). Rats exposed to HBO with no hemorrhage served as controls.
Time course changes in plasma endotoxin level, arterial ketone body ratio (AKBR),
serum tumor necrosis factor (TNF), interleukin-6 (IL-6), and their hepatic mRNA
were detected in the three groups. Plasma endotoxin levels increased
significantly after hemorrhage, and there were no significant differences between
the room air group and the hyperbaric group. In the room air group, AKBR dropped
rapidly after hemorrhage and became minimal at hour 1, which was associated with
significant increases in TNF-alpha and IL-6 at both mRNA and circulating levels.
HBO significantly attenuated decreases in AKBR after hemorrhage with a
significant reduction of mortality and cytokine induction. These results indicate
that HBO attenuated the cytokine induction after hemorrhage by improving liver
ischemia, and they suggest that tissue hypoxia may be responsible, at least in
part, for cytokine induction after massive hemorrhage.
PMID- 10780937
TI - Effect of enteral glutamine on leucine, phenylalanine and glutamine metabolism in
hypercortisolemic subjects.
AB - The effect of enteral Gln on protein and Gln metabolism was investigated during
experimental hypercortisolemia. Four groups of subjects that had received
corticosteroids and either enteral Gln (0.5 g x kg(-1) x day(-1) for 2 days) or
isonitrogenous Ala-Gly were studied in a fasted or in a fed state. In either
state, enteral Gln, compared with Ala-Gly, induced no statistically significant
change in the endogenous rate of Leu appearance, an index of proteolysis, Leu
oxidation, and nonoxidative Leu disposal, an index of protein synthesis, as
studied by kinetics of [1-(13)C]Leu. Similar data were obtained from kinetics of
[(2)H(5)]Phe, resulting in an unchanged protein balance in both cases. In
contrast, enteral Gln significantly decreased the endogenous rate of Gln
appearance and Gln de novo synthesis in the fed state (P < 0.05) as estimated by
the kinetics of [(15)N]Gln. This decrease in Gln de novo synthesis induced by Gln
could contribute to spare amino acids in hypercatabolic patients.
PMID- 10780938
TI - Functional comparison of the role of dynamin 2 splice variants on GLUT-4
endocytosis in 3T3L1 adipocytes.
AB - Previously, we reported that expression of a dominant-interfering neuronal
specific dynamin 1 (K44A/dynamin 1) inhibited the plasma membrane internalization
of GLUT-4 in 3T3L1 adipocytes (15). To investigate the role of the ubiquitously
expressed isoform of dynamin, dynamin 2, on adipocyte GLUT-4 internalization, and
to determine whether dynamin splice variants have functional specificity, we
expressed each of the four dynamin 2 isoforms (aa, ab, ba, and bb) as either wild
type proteins or GTPase-defective mutants. When expressed as enhanced green
fluorescent protein (EGFP) fusions, these isoforms were found to have overlapping
subcellular distributions being localized throughout the cell cytoplasm, on
punctate vesicles and in a perinuclear compartment. This distribution was
qualitatively similar to that of endogenous dynamin 2 and overlapped with GLUT-4
in the basal state. Expression of wild-type dynamin 2 isoforms had no effect on
the basal or insulin-stimulated distribution of GLUT-4; however, expression of
the dominant-interfering dynamin 2 mutants inhibited GLUT-4 endocytosis. These
data demonstrate that dynamin 2 is required for GLUT-4 endocytosis in 3T3L1
adipocytes and suggest that, relative to GLUT-4 trafficking, the dynamin 2 splice
variants have overlapping functions and are probably not responsible for
mediating distinct GLUT-4 budding events.
PMID- 10780939
TI - Osteoblast-like cells of the hypophysectomized rat: a model of aberrant
osteoblast development.
AB - In a previous work, we demonstrated that the osteoprogenitors derived from the
marrow stroma of the hypophysectomized (HX) rat demonstrate enhanced
proliferative and differentiation capacities when placed in an optimal
microenvironment. In this study, we sought to investigate the potential of the
trabecular osteoblast-like cells of the HX rat. These cells represent a more
mature pool of osteoblasts than the progenitors derived from the marrow stroma.
We examined all three stages of osteoblast development using trabecular
osteoblast-like cells derived from age-matched intact rats as a control. Using
thymidine incorporation and cell number as indicators of proliferation, we found
that these cells, like the osteoprogenitors derived from the HX rat, demonstrate
augmented proliferation when placed in culture. Additionally, type I collagen
expression remained at significant levels past the end stages of proliferation,
at which point it is expected to be downregulated. Matrix maturation markers,
such as alkaline phosphatase activity and bone sialoprotein expression, however,
were significantly lower than in the controls. Mineralization potential, as
measured by mineralized nodule formation, Ca(2+) content, and OPN and OCN
expression, was also significantly reduced. Our results have uncovered an
aberrant model of osteoblast development in which proliferation is deregulated,
resulting in a minimal capacity of these cells to develop into fully
differentiated mineralizing osteoblasts.
PMID- 10780940
TI - Effect of dexamethasone on fetal hepatic glutamine-glutamate exchange.
AB - Intravenous infusion of dexamethasone (Dex) in the fetal lamb causes a two- to
threefold increase in plasma glutamine and other glucogenic amino acids and a
decrease of plasma glutamate to approximately one-third of normal. To explore the
underlying mechanisms, hepatic amino acid uptake and conversion of L-[1
(13)C]glutamine to L-[1-(13)C]glutamate and (13)CO(2) were measured in six sheep
fetuses before and in the last 2 h of a 26-h Dex infusion. Dex decreased hepatic
glutamine and alanine uptakes (P < 0.01) and hepatic glutamate output (P <
0.001). Hepatic outputs of the glutamate (R(Glu,Gln)) and CO(2) formed from
plasma glutamine decreased to 21 (P < 0.001) and 53% (P = 0.009) of control,
respectively. R(Glu,Gln), expressed as a fraction of both outputs, decreased (P <
0.001) from 0.36 +/- 0.02 to 0.18 +/- 0.04. Hepatic glucose output remained
virtually zero throughout the experiment. We conclude that Dex decreases fetal
hepatic glutamate output by increasing the routing of glutamate carbon into the
citric acid cycle and by decreasing the hepatic uptake of glucogenic amino acids.
PMID- 10780941
TI - Citrate release by perfused rat hearts: a window on mitochondrial cataplerosis.
AB - Cytosolic citrate is proposed to play a crucial role in substrate fuel selection
in the heart. However, little is known about factors regulating the transfer of
citrate from the mitochondria, where it is synthesized, to the cytosol. Further
to our observation that rat hearts perfused under normoxia release citrate whose
(13)C labeling pattern reflects that of mitochondrial citrate (B. Comte, G.
Vincent, B. Bouchard, and C. Des Rosiers. J. Biol. Chem. 272: 26117-26124, 1997),
we report here data indicating that this citrate release is a specific process
reflecting the mitochondrial efflux of citrate, a process referred to as
cataplerosis. Indeed, measured rates of citrate release, which vary between 2 and
21 nmol/min, are modulated by the nature and concentration of exogenous
substrates feeding acetyl-CoA (fatty acid) and oxaloacetate (lactate plus
pyruvate) for the mitochondrial citrate synthase reaction. Such release rates
that represent at most 2% of the citric acid cycle flux are in agreement with the
activity of the mitochondrial tricarboxylate transporter whose participation is
also substantiated by 1) parallel variations in citrate release rates and tissue
levels of citrate plus malate, the antiporter, and 2) a lowering of the citrate
release rate by 1,2, 3-benzenetricarboxylic acid, a specific inhibitor of the
transporter. Taken together, the results from the present study indicate that
citrate cataplerosis is modulated by substrate supply, in agreement with the role
of cytosolic citrate in fuel partitioning, and occurs, at least in part, through
the mitochondrial tricarboxylate transporter.
PMID- 10780942
TI - Inverse relationship between protein intake and plasma free amino acids in
healthy men at physical exercise.
AB - The effect of a "normal" (n = 8) and "high" (n = 6) protein intake (1 and 2.5 g x
kg(-1) x day(-1), respectively) and of exercise on plasma amino acid (AA)
concentrations, insulin, and glucagon concentrations was followed throughout a
continuous 24-h period in adult male subjects at energy balance after six days on
a standardized diet and exercise program. Subjects were fasting from 2100 on day
6 to 1200 on day 7 and then fed 10 identical meals hourly until 2100. Physical
exercise was performed (46% maximal oxygen uptake) between 0830 and 1000
(fasting) and in a fed state (1600-1730) on each day. The normal-protein group
showed fasting plasma AA concentrations that were higher (P < 0.05) than those
for the high-protein group, except for leucine, methionine, and tyrosine.
Glutamine, glycine, alanine, taurine, and threonine concentrations were
distinctly higher ( approximately 30% or greater) throughout the 24-h period in
subjects consuming the normal- vs. the high-protein diets. Exercise appeared to
increase, although not profoundly, the plasma concentrations of amino acids
except for glutamate, histidine, ornithine, and tryptophan. The profound diet
related differences in plasma AA concentrations are only partially explained by
differences in the renal clearance of the amino acids. We speculate on the
possible metabolic basis for these findings.
PMID- 10780943
TI - Oxoproline kinetics and oxoproline urinary excretion during glycine- or sulfur
amino acid-free diets in humans.
AB - L-5-oxoproline (L-5-OP) is an intermediate in glutathione synthesis, possibly
limited by cysteine availability. Urinary 5-OP excretion has been proposed as a
measure of glycine availability. We investigated whether 5 days of dietary sulfur
amino acid (SAA-free) or glycine (Gly-free) restriction affects plasma kinetics
of 5-OP and urinary excretion of L- and D-5-OP in 6 healthy men. On day 6, L-5-[1
(13)C]oxoproline and [3,3-(2)H(2)]cysteine were infused intravenously for 8 h (3
h fast/5 h fed). In a control study (adequate amino acid mixture), plasma
oxoproline fluxes were 37.8 +/- 13.8 (SD) and 38.4 +/- 14.8 micromol x kg(-1) x
h(-1); oxidation accounted for 85% of flux. Cysteine flux was 47.9 +/- 8.5 and
43.2 +/- 8.5 micromol x kg(-1) x h(-1) for fast and fed phases, respectively.
Urinary excretion of L- and D-5-OP was 70 +/- 34 and 31.1 +/- 13.3 micromol/mmol
creatinine, respectively, during days 3-5, and 46.4 +/- 13.9 and 22.4 +/- 8.3
micromol/mmol over the 8-h tracer study. The 5-OP flux for the Gly-free diet was
higher (P = 0. 018) and tended to be higher for the SAA-free diet (P = 0.057)
when compared with the control diet. Oxidation rates were higher on the Gly-free
(P = 0.005) and SAA-free (P = 0.03) diets. Cysteine fluxes were lower on the the
Gly-free (P = 0.01) and the SAA-free diets (P = 0.001) compared with the control
diet. Rates of L-5-OP excretion were unchanged by withdrawal of SAA or Gly for 5
days but increased on day 6 (P = 0.005 and P = 0.019, respectively). Thus acute
changes in the dietary availability of SAA and Gly alter oxoproline kinetics and
urinary 5-OP excretion.
PMID- 10780944
TI - Threonine dehydrogenase is a minor degradative pathway of threonine catabolism in
adult humans.
AB - The threonine dehydrogenase (TDG) pathway is a significant route of threonine
degradation, yielding glycine in experimental animals, but has not been
accurately quantitated in humans. Therefore, the effect of a large excess of
dietary threonine, given either as free amino acid (+Thr) or as a constituent of
protein (+P-Thr), on threonine catabolism to CO(2) and to glycine was studied in
six healthy adult males using a 4-h constant infusion of L-[1-(13)C]threonine and
[(15)N]glycine. Gas chromatography-combustion isotope ratio mass spectrometry was
used to determine [(13)C]glycine produced from labeled threonine. Threonine
intakes were higher on +Thr and +P-Thr diets compared with control (126, 126, and
50 micromol x kg(-1) x h(-1), SD 8, P < 0.0001). Threonine oxidation to CO(2)
increased threefold in subjects on +Thr and +P-Thr vs. control (49, 45, and 15
micromol x kg(-1) x h(-1), SD 6, P < 0.0001). Threonine conversion to glycine
tended to be higher on +Thr and +P-Thr vs. control (3.5, 3.4, and 1.6 micromol x
kg(-1) x h(-1), SD 1.3, P = 0.06). The TDG pathway accounted for only 7-11% of
total threonine catabolism and therefore is a minor pathway in the human adult.
PMID- 10780945
TI - Induction of growth hormone (GH) mRNA by pulsatile GH-releasing hormone in rats
is pattern specific.
AB - Growth hormone-releasing hormone (GHRH) is a main inducer of growth hormone (GH)
pulses in most species studied to date. There is no information regarding the
pattern of GHRH secretion as a regulator of GH gene expression. We investigated
the roles of the parameters of exogenous GHRH administration (frequency,
amplitude, and total amount) upon induction of pituitary GH mRNA, GH content, and
somatic growth in the female rat. Continuous GHRH infusions were ineffective in
altering GH mRNA levels, GH stores, or weight gain. Changing GHRH pulse amplitude
between 4, 8, and 16 microg/kg at a constant frequency (Q3.0 h) was only
moderately effective in augmenting GH mRNA levels, whereas the 8 microg/kg and 16
microg/kg dosages stimulated weight gain by as much as 60%. When given at a 1.5-h
frequency, GHRH doubled the amount of GH mRNA, elevated pituitary GH stores, and
stimulated body weight gain. In the rat model, pulsatile but not continuous GHRH
administration is effective in inducing pituitary GH mRNA and GH content as well
as somatic growth. These studies suggest that the greater growth rate, pituitary
mRNA levels, and GH stores seen in male compared with female rats are likely
mediated, in part, by the endogenous episodic GHRH secretory pattern present in
males.
PMID- 10780946
TI - Dual regulation of leptin secretion: intracellular energy and calcium dependence
of regulated pathway.
AB - Rodent leptin is secreted by adipocytes and acutely regulates appetite and
chronically regulates body weight. Mechanisms for leptin secretion in cultured
adipocytes were investigated. Acutely, energy-producing substrates stimulated
leptin secretion about twofold. Biologically inert carbohydrates failed to
stimulate leptin secretion, and depletion of intracellular energy inhibited
leptin release. There appears to be a correlation between intracellular ATP
concentration and the rate of leptin secretion. Insulin increased leptin
secretion by an additional 25%. Acute leptin secretion is calcium dependent. When
incubated in the absence of calcium or in the presence of intracellular calcium
chelators, glucose plus insulin failed to stimulate leptin secretion. In
contrast, basal leptin secretion is secreted spontaneously and is calcium
independent. Adipocytes from fatter animals secrete more leptin, even in the
absence of calcium, compared with cells from thinner animals. Acute stimulus
secretion coupling mechanisms were then investigated. The potassium channel
activator diazoxide and the nonspecific calcium channel blockers nickel and
cadmium inhibited acute leptin secretion. These studies demonstrate that
intracellular energy production is important for acute leptin secretion and that
potassium and calcium flux may play roles in coupling intracellular energy
production to leptin secretion.
PMID- 10780947
TI - Protein turnover modifications induced by the protein feeding pattern still
persist after the end of the diets.
AB - This study was undertaken to determine whether the protein feeding pattern could
induce chronic adaptation of protein turnover. After a 15-day adaptive period,
elderly (68 yr) and young (26 yr) women received, for 14 days, a diet providing
200 KJ x kg fat-free mass (FFM)(-1) x day(-1), where the daily protein intake
(1.7 g protein x kg FFM(-1) x day(-1)) was either spread over 4 meals in the
spread pattern or mainly (80%) consumed at noon in the pulse pattern. One day
after the end of the dietary treatment, whole body leucine kinetics were measured
by use of a continuous [(13)C]leucine infusion, both in the postabsorptive state
and in the same fed state. The pulse pattern was able to induce, in young as in
elderly women, a lower postabsorptive leucine oxidation and endogenous leucine
flux than the spread pattern and improved the responsiveness of nonoxidative
leucine disposal during 4-h oral feeding. Thus the pulse pattern was able to
induce chronic regulation of protein metabolism in young as in elderly women.
PMID- 10780948
TI - Direct evidence of fiber type-dependent GLUT-4 expression in human skeletal
muscle.
AB - GLUT-4 expression in individual fibers of human skeletal muscles in younger and
older adults was studied. Furthermore, the dependency of insulin-stimulated
glucose uptake on fiber type distribution was investigated. Fiber type
distribution was determined in cryosections of muscle biopsies from 8 younger (29
yr) and 8 older (64 yr) healthy subjects, and estimates of GLUT-4 expression in
individual fibers were obtained by combining immunohistochemistry and stereology.
GLUT-4 was more abundantly expressed in slow compared with fast muscle fibers in
both younger (P < 0.007) and older (P < 0. 001) subjects. A 25% reduction of GLUT
4 density in fast fibers (P < 0.001) and an unchanged GLUT-4 density in slow
fibers were demonstrated in older compared with younger subjects. Insulin
stimulated glucose uptake rates measured by hyperinsulinemic, euglycemic clamp
were not correlated with the fraction of slow fibers in the young (r = -0.45, P >
0.25) or in the elderly (r = 0. 11, P > 0.75) subjects. In conclusion, in human
skeletal muscle, GLUT-4 expression is fiber type dependent and decreases with
age, particularly in fast muscle fibers.
PMID- 10780949
TI - Decreased cardiac output at the onset of diabetes: renal mechanisms and
peripheral vasoconstriction.
AB - Recently we reported that hindquarter blood flow, measured 24 h/day, decreased
progressively over the first 6 days of type 1 diabetes in rats. That response,
coupled with the tendency of mean arterial pressure to increase, suggested a
vasoconstrictor response. The purpose of this study was to measure the changes in
cardiac output together with the renal hemodynamic and excretory responses to
allow integrative determination of whether vasoconstriction likely accompanies
the onset of type 1 diabetes. Rats were instrumented with a Transonic flow probe
on the ascending aorta and with artery and vein catheters, and cardiac output and
mean arterial pressure were measured continuously, 24 h/day, throughout the
study. The induction of diabetes, by withdrawing intravenous insulin-replacement
therapy in streptozotocin-treated rats, caused a progressive decrease in cardiac
output that was 85 +/- 5% of control levels by day 7. This was associated with
significant increases in glomerular filtration rate, renal blood flow, and
microalbuminuria as well as urinary fluid and sodium losses, with a negative
cumulative sodium balance averaging 15.7 +/- 1.6 meq by day 7. Restoring insulin
replacement therapy reversed the renal excretory responses but did not correct
the negative sodium balance, yet cardiac output returned rapidly to control
values. Increasing sodium intake during the diabetic and recovery periods also
did not significantly affect the cardiac output response during any period. These
results indicate that cardiac output decreases significantly at the onset of type
1 diabetes without glycemic control, and although volume loss may contribute to
this response, there also is a component that is not volume or sodium dependent.
We suggest this may be due to vasoconstriction, but to what extent local blood
flow autoregulation or active vasoconstriction may have mediated that response is
not known.
PMID- 10780950
TI - Functional alteration of dihydropyridine-sensitive Ca(2+) channels in the adrenal
glomerulosa of pregnant rats.
AB - Our previous work on aldosterone secretion suggested that dihydropyridine
sensitive calcium channels, one type of voltage-dependent calcium channels
(VDCC), are functionally impaired in adrenal capsule preparations from the
pregnant rat. The aim of this study was to determine whether, during pregnancy,
the density and/or activity of these channels is altered in the adrenal zona
glomerulosa. These VDCC measured with [(3)H]nitrendipine binding were not
different between membrane preparations of nonpregnant and pregnant rats. Western
blots were performed using two different antibodies, a polyclonal (PcAb) directed
against the alpha(1)-subunit of VDCC and a monoclonal (McAb) that recognizes an
intracellular domain of that protein. McAb immunoreactivity showed a significant
decrease in preparations from pregnant rats, whereas no difference was observed
with PcAb. VDCC activity was estimated by (45)Ca(2+) uptake in isolated adrenal
cortex and by intracellular calcium concentration ([Ca(2+)](i)) in adrenal
glomerulosa cells with the Ca(2+) probe fura PE3. These measurements revealed
that KCl stimulation produced greater Ca(2+) influx in nonpregnant than in
pregnant rats. Nifedipine (a blocker of VDCC) inhibited this stimulation only in
nonpregnant rats, whereas BAY K 8644 (an activator of VDCC) increased Ca(2+)
influx in pregnant rats only. These data suggest that, during pregnancy, the
altered regulation of calcium homeostasis in adrenal glomerulosa is linked to a
conformational alteration of VDCC.
PMID- 10780951
TI - Single exposure to testosterone in adulthood rapidly induces regularity in the
growth hormone release process.
AB - The neonatal gonadal steroid milieu is known to be important in imprinting the
striking sexual dimorphism of growth hormone (GH) secretion; however, the
influence of the sex steroids on GH control in adult life and their
mechanism/site of action are largely unknown. In the present study, we tested the
hypothesis that testosterone (T) subserves the gender-specific regularity of the
GH release process in adulthood. The approximate entropy statistic (ApEn) was
used to quantify the degree of regularity of GH release patterns over time.
Eighteen hours after a single subcutaneous injection of 1 mg T, both sham
operated and ovariectomized (OVX) female adult rats displayed plasma GH profiles
that were strikingly similar to the regular male-like ultradian rhythm of GH
secretion. The highest ApEn values, denoting greater disorderliness of GH
secretion, were observed in the ovary-intact group, and T injection significantly
(P < 0.001) reduced this irregularity whether or not the ovaries were present.
Serial intravenous injections of GH-releasing hormone (GHRH) caused a similar
increase in plasma GH levels in sham-operated females independently of time of
administration. In contrast, female rats administered T exhibited a male-like
intermittent pattern of GH responsiveness to GHRH, the latter known to be due to
the cyclic release of endogenous somatostatin. These results demonstrate that
acute exposure to T during adult life can rapidly and profoundly "masculinize" GH
pulse-generating circuits in the female rat. Our findings suggest that the
enhanced orderliness characteristic of the GH release process in males, compared
with females, is regulated by T. We postulate that this T-induced regularity is
mediated at the level of the hypothalamus by inducing regularity in somatostatin
secretion, which in turn governs overall GH periodicity.
PMID- 10780952
TI - Subdivisions of subcutaneous abdominal adipose tissue and insulin resistance.
AB - Whereas truncal (central) adiposity is strongly associated with the insulin
resistant metabolic syndrome, it is uncertain whether this is accounted for
principally by visceral adiposity (VAT). Several recent studies find as strong or
stronger association between subcutaneous abdominal adiposity (SAT) and insulin
resistance. To reexamine the issue of truncal adipose tissue depots, we performed
cross-sectional abdominal computed tomography, and we undertook the novel
approach of partitioning SAT into the plane superficial to the fascia within
subcutaneous adipose tissue (superficial SAT) and that below this fascia (deep
SAT), as well as measurement of VAT. Among 47 lean and obese glucose-tolerant men
and women, insulin-stimulated glucose utilization, measured by euglycemic clamp,
was strongly correlated with both VAT and deep SAT (r = -0.61 and -0.64,
respectively; both P < 0.001), but not with superficial SAT (r = -0.29, not
significant). Also, VAT and deep SAT followed a highly congruent pattern of
associations with glucose and insulin area under the curve (75-g oral glucose
tolerance test), mean arterial blood pressure, apoprotein-B, high-density
lipoprotein cholesterol, and triglyceride. Superficial SAT had markedly weaker
association with all these parameters and instead followed the pattern observed
for thigh subcutaneous adiposity. We conclude that there are two functionally
distinct compartments of adipose tissue within abdominal subcutaneous fat and
that the deep SAT has a strong relation to insulin resistance.
PMID- 10780953
TI - Epinephrine infusion during moderate intensity exercise increases glucose
production and uptake.
AB - The glucoregulatory response to intense exercise [IE, >80% maximum O(2) uptake
(VO(2 max))] comprises a marked increment in glucose production (R(a)) and a
lesser increment in glucose uptake (R(d)), resulting in hyperglycemia. The R(a)
correlates with plasma catecholamines but not with the glucagon-to-insulin
(IRG/IRI) ratio. If epinephrine (Epi) infusion during moderate exercise were able
to markedly stimulate R(a), this would support an important role for the
catecholamines' response in IE. Seven fit male subjects (26 +/- 2 yr, body mass
index 23 +/- 0.5 kg/m(2), VO(2 max) 65 +/- 5 ml x kg(-1) x min(-1)) underwent 40
min of postabsorptive cycle ergometer exercise (145 +/- 14 W) once without
[control (CON)] and once with Epi infusion [EPI (0.1 microg x kg(-1) x min(-1))]
from 30 to 40 min. Epi levels reached 9.4 +/- 0.8 nM (20x rest, 10x CON). R(a)
increased approximately 70% to 3.75 +/- 0.53 in CON but to 8.57 +/- 0.58 mg x kg(
1) x min(-1) in EPI (P < 0.001). Increments in R(a) and Epi correlated (r(2) =
0.923, P = 0.01). In EPI, peak R(d) (5.55 +/- 0.54 vs. 3.38 +/- 0.46 mg x kg(
1) x min(-1), P = 0.006) and glucose metabolic clearance rate (MCR, P = 0.018)
were higher. The R(a)-to-R(d) imbalance in EPI caused hyperglycemia (7.12 +/-
0.22 vs. 5.59 +/- 0.22 mM, P = 0.001) until minute 60 of recovery. A small and
late IRG/IRI increase (P = 0.015 vs. CON) could not account for the R(a)
increase. Norepinephrine (approximately 4x increase at peak) did not differ
between EPI and CON. Thus Epi infusion during moderate exercise led to increments
in R(a) and R(d) and caused rises of plasma glucose, lactate, and respiratory
exchange ratio in fit individuals, supporting a regulatory role for Epi in IE.
Epi's effects on R(d) and MCR during exercise may differ from its effects at
rest.
PMID- 10780954
TI - GLUT-1 reduces hypoxia-induced apoptosis and JNK pathway activation.
AB - Many studies have suggested that enhanced glucose uptake protects cells from
hypoxic injury. More recently, it has become clear that hypoxia induces apoptosis
as well as necrotic cell death. We have previously shown that hypoxia-induced
apoptosis can be prevented by glucose uptake and glycolytic metabolism in cardiac
myocytes. To test whether increasing the number of glucose transporters on the
plasma membrane of cells could elicit a similar protective response, independent
of the levels of extracellular glucose, we overexpressed the facilitative glucose
transporter GLUT-1 in a vascular smooth muscle cell line. After 4 h of hypoxia,
the percentage of cells that showed morphological changes of apoptosis was 30.5
+/- 2.6% in control cells and only 6.0 +/- 1.1 and 3.9 +/- 0.3% in GLUT-1
overexpressing cells. Similar protection against cell death and apoptosis was
seen in GLUT-1-overexpressing cells treated for 6 h with the electron transport
inhibitor rotenone. In addition, hypoxia and rotenone stimulated c-Jun-NH(2)
terminal kinase (JNK) activity >10-fold in control cell lines, and this
activation was markedly reduced in GLUT-1-overexpressing cell lines. A
catalytically inactive mutant of MEKK1, an upstream kinase in the JNK pathway,
reduced hypoxia-induced apoptosis by 39%. These findings show that GLUT-1
overexpression prevents hypoxia-induced apoptosis possibly via inhibition of
stress-activated protein kinase pathway activation.
PMID- 10780955
TI - Upregulation of bradykinin B1-receptor expression after myocardial infarction.
AB - To determine the influence of the myocardial infarction (MI) on bradykinin B1
receptor (B1R) regulation, we studied its expression in the left ventricle (LV)
after MI. Rats were submitted to a permanent occlusion of the left coronary
artery. Six hours, 24 h and 6 days after MI or after sham operation, left
ventricular pressure (LVP) and dP/dt(max) were measured. LV-total RNA was
extracted and B1R expression was analysed by a RNase-protection assay (each group
n = 6). LVP and dP/dt(max) were impaired at all time points after MI. Basal B1R
expression was not detectable in controls. Six hours after MI, the B1R expression
was upregulated and reached a maximum 24 h after MI (4 fold vs. 6 h). Six days
post-MI, B1R expression returned to levels found 6 h after MI. These data are the
first demonstration for an induced myocardial B1R expression in an in vivo model
of MI.
PMID- 10780956
TI - Peroxynitrite-mediated release of arachidonic acid from PC12 cells.
AB - A short term exposure of PC12 cells to a concentration of tert-butylhydroperoxide
(tB-OOH) causing peroxynitrite-dependent DNA damage and cytotoxiticity promoted a
release of arachidonic acid (AA) that was sensitive to phospholipase A(2)
(PLA(2)) inhibitors and insensitive to phospholipase C or diacylglycerol lipase
inhibitors. The extent of AA release was also mitigated by nitric oxide synthase
(NOS) inhibitors and peroxynitrite scavengers. Low levels (10 microM) of
authentic peroxynitrite restored the release of AA mediated by tB-OOH in NOS
inhibited cells whereas concentrations of peroxynitrite of 20 microM, or higher,
effectively stimulated a PLA(2) inhibitor-sensitive release of AA also in the
absence of additional treatments. These results are consistent with the
possibility that endogenous as well as exogenous peroxynitrite promotes
activation of PLA(2).
PMID- 10780957
TI - Upregulation by glucocorticoids of responses to eosinopoietic cytokines in bone
marrow from normal and allergic mice.
AB - Since the production of eosinopoietic cytokines (GM-CSF, IL-3, IL-5) is inhibited
by glucocorticoids, while responsiveness to these cytokines is enhanced in bone
marrow of allergic mice, we studied the ability of glucocorticoids to modulate
murine bone-marrow eosinopoiesis. Progenitor (semi-solid) and/or precursor
(liquid) cultures were established from bone-marrow of: (a) normal mice; (b)
ovalbumin-sensitized and challenged mice or (c) dexamethasone (1-5 mg kg(-1))
injected mice. Cultures were established with GM-CSF (2 ng ml(-1)) or IL-5 (1 ng
ml(-1)), respectively, alone or associated with dexamethasone, hydrocortisone or
corticosterone. Total myeloid colony numbers, frequency and size of eosinophil
colonies, and numbers of eosinophil-peroxidase-positive cells were determined at
day 7. In BALB/c mice, dexamethasone (10(-7) M) increased GM-CSF-stimulated
myeloid colony formation (P = 0.01), as well as the frequency (P=0.01) and size
(P<0.01) of eosinophil colonies. Dexamethasone (10(-7) M) alone had no effect.
Dexamethasone (10(-7)-10(-10) M) increased (P<0.002) eosinophil precursor
responses to IL-5. Potentiation by dexamethasone was still detectable: (a) on low
density, immature, nonadherent BALB/c bone-marrow cells, (b) on bone-marrow from
other strains, and (c) on cells from allergic mice. Hydrocortisone and
corticosterone had similar effects. Dexamethasone administered in vivo, 24 h
before bone-marrow harvest, increased subsequent progenitor responses to GM-CSF
(P = 0.001) and precursor responses to IL-5 (P<0.001). These effects were blocked
by RU 486 (20 mg kg(-1), orally, 2 h before dexamethasone, or added in vitro at
10 microM, P<0.001). Glucocorticoids, acting in vivo or in vitro, through
glucocorticoid receptors, enhance bone-marrow eosinopoiesis in naive and allergic
mice.
PMID- 10780958
TI - Mechanisms of suppression of inducible nitric oxide synthase (iNOS) expression in
RAW 264.7 cells by andrographolide.
AB - Andrographolide, an active component found in leaves of Andrographis paniculata,
has been reported to exhibit nitric oxide (NO) inhibitory property in endotoxin
stimulated macrophages, however, the detailed mechanisms remain unclear. In the
present study we investigated the effect of andrographolide on the expression of
inducible NO synthase (iNOS) mRNA, protein, and enzyme activity in RAW 264.7
macrophages stimulated with lipopolysaccharide (LPS) plus interferon-gamma (IFN
gamma). RAW 264.7 cells stimulated with LPS/IFN-gamma activated NO production; in
this condition andrographolide (1-100 microM) inhibited NO production in a dose
dependent manner with an IC(50) value of 17.4+/-1.1 microM. Andrographolide also
reduces the expression of iNOS protein level but without a significant effect on
iNOS mRNA. The reduction of iNOS activity is thought to be caused by decreased
expression of iNOS protein. In a protein stability assay, andrographolide
moderately but significantly reduced the amount of iNOS protein as suggested by
accelerating degradation. Furthermore, andrographolide also inhibited total
protein de novo synthesis as demonstrated by [(35)S]-methionine incorporation. As
a whole, these data suggest that andrographolide inhibits NO synthesis in RAW
264.7 cells by reducing the expression of iNOS protein and the reduction could
occur through two additional mechanisms: prevention of the de novo protein
synthesis and decreasing the protein stability via a post-transcriptional
mechanism. It is also possible that inhibition of iNOS protein expression and NO
production under immune stimulation and/or bacteria infection may explain, in
part, the beneficial effects of andrographolide as an anti-inflammatory agent.
PMID- 10780959
TI - Pharmacological comparison of the effect of ibogaine and 18-methoxycoronaridine
on isolated smooth muscle from the rat and guinea-pig.
AB - Ibogaine and 18-methoxycoronaridine are naturally occurring alkaloids reported to
possess antiaddictive properties in several models of drug dependence. We have
examined their effect at mu-opioid receptors regulating neurogenic contractions
of several smooth muscle preparations and also against spontaneous contractions
of the rat isolated portal vein. Ibogaine (pIC(50) 5.28) and 18
methoxycoronaridine (pIC(50) 5.05) caused a concentration-dependent inhibition of
cholinergic contractions of the guinea-pig ileum which was not affected by the
opioid receptor antagonist naloxone (1 microM). In the rat isolated vas deferens
ibogaine and 18-methoxycoronaridine caused a concentration-dependent enhancement
of purinergic contractions. Both agents (30 microM) caused a 3 - 5 fold rightward
displacement of DAMGO-induced inhibition of purinergic contractions, but similar
effects were observed for ibogaine against alpha(2)-adrenoceptor-mediated
inhibition of neurogenic responses. In the guinea-pig isolated bladder both
ibogaine (10 microM) and 18-methoxycoronaridine (10 microM) caused a 2 fold
increase in the purinergic component of neurogenic contractions without
significantly altering cholinergic contractions or responses to exogenous ATP. In
contrast, ibogaine (1 - 30 microM), but not 18-methoxycoronaridine, caused a
concentration-dependent enhancement of spontaneous contractions of the rat
isolated portal vein. In summary, while ibogaine and 18-methoxycoronaridine
modulated electrically-evoked contractions in the three preparations examined, we
have no evidence for a selective interaction with pre-junctional mu-opioid
receptors. The pronounced enhancement of purinergic contractions produced by both
agents is a novel finding and worthy of further investigation.
PMID- 10780960
TI - Splice isoforms of alpha(1a)-adrenoceptor in rabbit.
AB - Two splice isoforms of rabbit alpha(1a)-adrenergic receptor (AR), (named
alpha(1a)-OCU.2-AR and alpha(1a)-OCU.3-AR) have been isolated from the liver cDNA
library in addition to the previously reported isoform (alpha(1a)-OCU.1-AR).
Although they have the identical splice position with human alpha(1a)-AR
isoforms, the C-terminal sequences are distinct from those of human isoforms.
Among these rabbit alpha(1a)-AR isoforms, there are no significant differences in
pharmacological properties: high affinity for prazosin, WB4101, KMD-3213 and
YM617 and low affinity for BMY7378, using COS-7 cells expressing each isoform by
radioligand binding assay. Competitive reverse transcription-polymerase chain
reaction (RT - PCR) analysis revealed that mRNA of alpha(1a)-ARs was expressed in
liver, thoracic aorta, brain stem and thalamus of rabbit. The splice isoforms
exhibited a distinct distribution pattern in rabbit; alpha(1a)-OCU. 1-AR was
expressed most abundantly in those tissues. CHO clones, stably expressing each
isoforms with receptor density 740 fmol mg(-1) protein in alpha(1a)-OCU.1-AR,
1200 fmol mg(-1) in alpha(1a)-OCU.2-AR and 570 fmol mg(-1) in alpha(1a)-OCU.3-AR,
respectively, showed a noradrenaline-induced increase in inositol trisphosphate
which was suppressed by prazosin. Noradrenaline elicited a concentration
dependent increase in extracellular acidification rate (EAR) in the CHO clones
with pEC(50) values of 6. 19 for alpha(1a)-OCU.1-AR, 6.49 for alpha(1a)-OCU.2-AR
and 6.58 for alpha(1a)-OCU.3-AR, respectively. Noradrenaline caused a
concentration-dependent increase in intracellular Ca(2+) concentration
([Ca(2+)]i) in the CHO clones with pEC(50) values of 6. 14 for alpha(1a)-OCU.1
AR, 7.25 for alpha(1a)-OCU.2-AR and 7.70 for alpha(1a)-OCU.3-AR, respectively. In
conclusion, the present study shows the occurrence of three splice isoforms of
rabbit alpha(1a)-AR, which are unique in C-terminal sequence and in tissue
distribution. They show similar pharmacological profiles in binding studies but
alpha(1a)-OCU.3-AR had the highest potency of noradrenaline in functional studies
in spite of the lowest receptor density. These findings suggest that the
structure of C-terminus of alpha(1a)-ARs may give the characteristic functional
profile.
PMID- 10780961
TI - O-1057, a potent water-soluble cannabinoid receptor agonist with antinociceptive
properties.
AB - Cannabinoids have low water solubility, necessitating the use of a solubilizing
agent. In this paper we investigated whether a novel water-soluble cannabinoid, 3
(5'-cyano-1', 1'-dimethylpentyl)-1-(4-N-morpholinobutyryloxy)-Delta(8)-
tetrahydroca nnabinol hydrochloride (O-1057), would interact with cannabinoid
receptors when water or saline were used as the only vehicle. O-1057 displaced
[(3)H]-CP55940 from specific binding sites on Chinese hamster ovary (CHO) cell
membranes expressing CB(1) or CB(2) cannabinoid receptors, with pK(i) values of
8.36 and 7.95 respectively. It also displaced [(3)H]-CP55940 from specific
binding sites on rat brain membranes (pK(i) = 7.86). O-1057 inhibited forskolin
stimulated cyclic AMP production by both CB(1)- and CB(2)-transfected CHO cells
(pEC(50) = 9.16 and 9.72 respectively), its potency matching that of CP55940 and
exceeding that of Delta(9)-tetrahydrocannabinol. In the mouse isolated vas
deferens, O-1057 inhibited electrically-evoked contractions with pEC(50) and
E(max) values of 9.73 and 76.84% respectively. It was antagonized by 100 nM
SR141716A, the pK(B) of SR141716A against O-1057 (8.90) approximating to that
against CP55940 (8.97). O-1057 also behaved as a CB(1) receptor agonist in vivo,
reducing mouse spontaneous activity and rectal temperature when injected
intravenously and inducing antinociception in the mouse tail flick test when
given intravenously (ED(50) = 0.02 mg kg(-1)), intrathecally,
intracerebroventricularly or by gavage. In all these assays, O-1057 was more
potent than Delta(9)-tetrahydrocannabinol and, at 0.1 mg kg(-1) i.v., was
antagonized by SR141716A (3 mg kg(-1) i.v.). These data demonstrate the ability
of the water-soluble cannabinoid, O-1057, to act as a potent agonist at CB(1) and
CB(2) receptors and warrant investigation of the clinical potential of O-1057 as
an analgesic.
PMID- 10780962
TI - Effect of heparin on antigen-induced airway responses and pulmonary leukocyte
accumulation in neonatally immunized rabbits.
AB - The effect of single administrations of aerosolized heparin, low molecular weight
heparin (LMWH) and the linear polyanionic molecule, polyglutamic acid (PGA) were
examined on antigen-induced airway hyperresponsiveness and leukocyte accumulation
in neonatally immunized rabbits. Adult litter-matched NZW rabbits immunized
within 24 h of birth with Alternaria tenuis antigen were treated with heparin,
LMWH or PGA prior to or following antigen challenge (Alternaria tenuis). For each
drug-treated group, a parallel group of rabbits were treated with the appropriate
vehicle. In all groups, airway responsiveness to inhaled histamine and
bronchoalveolar lavage (BAL) was performed 24 h prior to and following antigen
challenge. Basal lung function in terms of resistance (R(L)) and dynamic
compliance (C(dyn)) and acute bronchoconstriction was unaltered by pre-treatment
with heparin, LMWH or PGA compared to their respective vehicles 24 h prior to or
following antigen challenge. In vehicle-treated animals, airway
hyperresponsiveness to inhaled histamine was indicated by an increase in the
maximal responses of the cumulative concentration-effect curves to histamine and
reductions in R(L)PC(50) and C(dyn)PC(35) values 24 h following antigen
challenge. Heparin and LMWH given prior to antigen challenge significantly
inhibited the development of airway hyperresponsiveness, whereas PGA did not.
When given following antigen challenge, all three drugs failed to inhibit the
development of airway hyperresponsiveness. Eosinophil and neutrophil cell numbers
in BAL fluid increased significantly 24 h following antigen challenge. Heparin,
LMWH and PGA failed to inhibit the increase in cell numbers following antigen
challenge whether given prior to or following antigen challenge.
PMID- 10780963
TI - Histamine H(3)-receptor antagonists inhibit gastroprotection by (R)-alpha
methylhistamine in the rat.
AB - (R)-alpha-methylhistamine, a selective agonist of histamine H(3) receptors, is
capable of protecting the gastric mucosa against differently acting damaging
agents. The objective of the present study was to determine whether H(3)
receptors mediate its protective action in the rat. Gastric mucosal lesions were
induced intragastrically (i.g.) by 0.6 N HCl, 1 ml rat(-1). (R)-alpha
methylhistamine, 100 mg kg(-1) i.g., substantially reduced the severity of
macroscopically and histologically assessed damage caused by concentrated acid.
Prior treatment with highly selective H(3)-receptor antagonists, ciproxifan (0.3,
1 and 3 mg kg(-1) i.g.) and clobenpropit (3, 10 and 30 mg kg(-1) i.g.), dose
dependently inhibited the protection exerted by (R)-alpha-methylhistamine up to a
complete reversal. When given alone at high doses, both antagonists tended to
worsen the HCl-induced histologic damage. During basal conditions, (R)-alpha
methylhistamine, 100 mg kg(-1) i. g., caused a significant increase in titratable
acidity of the gastric juice. Prior treatment with ciproxifan (3 mg kg(-1) i.g.)
and clobenpropit (30 mg kg(-1) i.g.) did not alter the secretory response to (R)
alpha-methylhistamine. Clobenpropit alone, but not ciproxifan, increased the
volume of gastric juice, and both compounds alone had no effect on titratable
acid. Present findings support evidence that H(3) receptors are actively involved
in the maintenance of gastric mucosal integrity, with no apparent role in the
regulation of basal gastric acid secretion.
PMID- 10780964
TI - An improved in vitro bioassay for the study of 5-HT(4) receptors in the human
isolated large intestinal circular muscle.
AB - Recently, it was demonstrated that 5-HT induces relaxation of human colon
circular muscle through activation of 5-HT(4) receptors and 5-HT(7) receptors.
The aim of the current study was to develop a new in vitro bioassay of human
colon that would facilitate the pharmacological analysis of 5-HT responses
mediated solely by 5-HT(4) receptors. Contracting circular muscle strips with KCl
(80 mM) yielded a stable contractile tension and, in contrast to muscarinic
cholinoceptor agonists and histamine, a profound reduction of spontaneous
contractility. This allowed the establishment of reproducible, fully-defined,
agonist concentration-response curves by cumulative dosing. Under these
conditions, 5-HT induced a concentration-dependent relaxation (pEC(50) 7.31, Hill
slope 0.91). Neither methysergide (10 microM) nor granisetron (1 microM) affected
the 5-HT-induced relaxation, suggesting that 5-HT(1), 5-HT(2), 5-HT(3), 5-ht(5),
5-HT(6) or 5-HT(7) receptors are not involved. The lack of effect of tetrodotoxin
(0.3 microM) indicated a direct effect of 5-HT on the smooth muscle. The
selective 5-HT(4) receptor antagonists GR 113808, GR 125487 and RS 39604
competitively antagonized the 5-HT-induced relaxation (pK(B) 9.43, 10.12 and
8.53, respectively). SB 204070 (1 nM) produced a rightward shift (pA(2) 10.34)
and depression of the 5-HT curve. These affinity estimates are similar to those
previously reported for 5-HT(4) receptors. The selective 5-HT(4) receptor
agonists, prucalopride and R076186, induced relaxations (pEC(50) 7.50 and 7.57,
respectively), that were blocked by GR 113808 (3 nM), yielding pA(2) estimates of
9.31 and 9.21, respectively. To summarise, in KCl (80 mM)-contracted muscle
strips, 5-HT induces relaxation through activation of a homogeneous smooth muscle
5-HT(4) receptor population. This new bioassay allows the focused,
pharmacological characterization of human colonic 5-HT(4) receptors in vitro.
PMID- 10780965
TI - Pharmacokinetic-pharmacodynamic modelling of the convulsant interaction between
norfloxacin and biphenyl acetic acid in rats.
AB - Fluoroquinolones (FQs) are associated with a low incidence of central nervous
system (CNS) side effects, possibly leading to convulsions, especially when co
administered with nonsteroidal anti-inflammatory drugs (NSAIDS). Although the in
vivo pro-convulsant activity of NSAIDS is essentially unknown, the convulsant
potential of FQs is traditionally evaluated by in vitro gamma-aminobutyric acid
(GABA) binding experiments in the presence of 4-biphenyl acetic acid (BPAA), the
active metabolite of fenbufen. The aim of this study was therefore to investigate
the BPAA-norfloxacin convulsant interaction in vivo. Male Sprague-Dawley rats (n
= 27) were given BPAA orally, at various doses 1 h before norfloxacin infusion,
which was maintained until the onset of maximal seizures, when cerebrospinal
fluid (CSF) and plasma samples were collected for analysis. An inhibitory E(max)
effect model with a baseline effect parameter was fitted to the norfloxacin
versus BPAA concentrations in the CSF, previously shown to be part of the
biophase. This model includes three parameters: the concentrations of norfloxacin
in the absence of BPAA (C(CSF0, Nor)), and when BPAA concentration tends toward
infinity (C(CSFbase, Nor)), and the BPAA concentration for which half of the
maximal effect is observed (C(CSF50, BPAA)). The maximal proconvulsant effect of
BPAA is given by the C(CSF0, Nor) / C(CSFbase, Nor) ratio, estimated to
approximately 6 in this study. Derived models were developed in plasma to account
for the non-linear CSF diffusion of norfloxacin and protein binding of BPAA. In
conclusion this study has shown that the convulsant interaction between
norfloxacin and BPAA in rats, can be adequately characterized by modelling of the
CSF concentrations of the two drugs at the onset of activity, following their
administration in various proportions.
PMID- 10780966
TI - Selective block of late Na(+) current by local anaesthetics in rat large sensory
neurones.
AB - The actions of lignocaine and benzocaine on transient and late Na(+) current
generated by large diameter (> or =50 microm) adult rat dorsal root ganglion
neurones, were studied using patch-clamp techniques. Both drugs blocked whole
cell late Na(+) current in a concentration-dependent manner. At 200 ms following
the onset of a clamp step from -110 to -40 mV, the apparent K for block of late
Na(+) current by lignocaine was 57.8+/-15 microM (mean+/-s.e.mean, n = 4). The
value for benzocaine was 24.9+/-3.3 microM, (mean+/-s.e. mean, n = 3). The effect
of lignocaine on transient current, in randomly selected neurones, appeared
variable (n = 8, half-block from approximately 50 to 400 microM). Half-block by
benzocaine was not attained, but both whole-cell (n = 11) and patch data
suggested a high apparent K,>250 microM. Transient current always remained after
late current was blocked. The voltage-dependence of residual late current steady
state inactivation was not shifted by 20 microM benzocaine (n = 3), whereas 200
microM benzocaine shifted the voltage-dependence of transient current steady
state inactivation by -18.7+/-5.9 mV (mean+/-s.e.mean, n = 4). In current-clamp,
benzocaine (250 microM) could block subthreshold, voltage-dependent inward
current, increasing the threshold for eliciting action potentials, without
preventing their generation (n = 2). Block of late Na(+) current by systemic
local anaesthetic may play a part in preventing ectopic impulse generation in
sensory neurones.
PMID- 10780967
TI - Central and peripheral cannabinoid modulation of gastrointestinal transit in
physiological states or during the diarrhoea induced by croton oil.
AB - We have evaluated the effect of cannabinoid drugs, administered intraperitoneally
(i.p.) or intracerebroventricularly (i.c.v.) on upper gastrointestinal transit in
control and in croton oil-treated mice. The cannabinoid agonists, WIN 55,212-2 (2
239 nmol mouse(-1)) and cannabinol (24-4027 nmol mouse(-1)), decreased while the
CB(1) antagonist SR141716A (2-539 nmol mouse(-1)) increased transit in control
mice. WIN 55,212-2, cannabinol and SR141716A had lower ED(50) values when
administered i.c.v., than when administered i.p. The CB(2) antagonist SR144528
(52 nmol mouse(-1), i.p.) was without effect. During croton oil (0.01 ml mouse(
1), p.o.)-induced diarrhoea, the ED(50) values of i.p. -injected WIN 55,212-2 and
cannabinol (but not SR141716A) were significantly decreased (compared to control
mice). However, the ED(50) values of WIN 55,212-2 were similar after i.p. or
i.c.v. administration. The inhibitory effects of WIN 55,212-2 and cannabinol were
counteracted by SR141716A (16 nmol mouse(-1), i.p.) but not by SR144528 (52 nmol
mouse(-1), i.p.) both in control and croton-oil treated mice. Ganglionic blockade
with hexamethonium (69 nmol mouse(-1), i.p.) did not modify the inhibitory effect
of i.p. -injected cannabinoid agonists either in control or in croton-oil treated
mice. The lower ED(50) values of cannabinoid drugs after i.c.v. administration
suggest a central (CB(1)) site of action. However, a peripheral site of action is
suggested by the lack of effect of hexamethonium. In addition, croton oil-induced
diarrhoea enhances the effect of cannabinoid agonists by a peripheral mechanism.
PMID- 10780968
TI - Loss of muscarinic antinociception by antisense inhibition of M(1) receptors.
AB - The effect on cholinergic analgesia of inactivation of the M(1) gene by an
antisense oligodeoxyribonucleotide (aODN) was investigated in the mouse hot plate
test. Mice received a single intracerebroventricular (i.c.v.) injection of anti
M(1) aODN (0.3, 1. 0 or 2.0 nmol per injection), degenerate ODN (dODN) or vehicle
on days 1, 4 and 7. A dose-dependent inhibition of the antinociception induced by
the muscarinic agonists oxotremorine (0.1 mg kg(-1) s.c.) and McN-A-343 (30
microg per mouse i.c.v.) and the cholinesterase inhibitor physostigmine (0.2 mg
kg(-1) s.c.) was observed 24 h after the last i.c.v. injection of aODN. Time
course experiments revealed that, after the end of the aODN treatment,
sensitivity to analgesic drugs progressively appeared reaching the normal range
at 96 h. The anti-M(1) aODN was selective against muscarinic antinociception
since the enhancement of pain threshold produced by morphine and baclofen were
not affected by the above-mentioned treatment. dODN, used as control, did not
affect muscarinic antinociception. Binding studies evidenced a selective
reduction of M(1) receptor levels in the hippocampus of aODN-treated mice.
Neither aODN, dODN nor vehicle produced any behavioural impairment of mice as
revealed by the rota-rod and Animex experiments. These results indicate that
activation of M(1) muscarinic receptor subtype is fundamental to induce central
cholinergic analgesia in mice.
PMID- 10780969
TI - In vitro and in vivo effects of kinin B(1) and B(2) receptor agonists and
antagonists in inbred control and cardiomyopathic hamsters.
AB - The aims of this study were to examine the possible alterations occurring in the
effects of kinins on isolated aortae of inbred control (CHF 148) and
cardiomyopathic (CHF 146) hamsters of 150 - 175 and 350 - 375 days of age.
Bradykinin (BK) and desArg(9)BK contracted isolated aortae (with or without
endothelium) of hamsters of both strains and ages. After tissue equilibration (90
min), responses elicited by both kinin agonists were stable over the time of
experiments. The patterns of isometric contractions of BK and desArg(9)BK were
however found to be different; desArg(9)BK had a slower onset and a longer
duration of action than BK. Potencies (pEC(50) values) of BK in all groups of
hamsters were significantly increased by preincubating the tissues with captopril
(10(-5) M). No differences in the pEC(50) values and the E(max) values for BK or
desArg(9)BK were seen between isolated vessels from inbred control and
cardiomyopathic hamsters. The myotropic effect of BK was inhibited by the
selective non peptide antagonist, FR 173657 (pIC(50) 7.25+/-0.12 at the
bradykinin B(2) receptor subtype (B(2) receptor)). Those of desArg(9)BK, at the
bradykinin B(1) receptor subtype (B(1) receptor) were abolished by either R 715
(pIC(50) of 7. 55+/-0.05; alpha(E) = 0), Lys[Leu(8)]desArg(9)BK (pIC(50) of
7.21+/-0. 01; alpha(E) = 0.22) or [Leu(8)]desArg(9)BK (pIC(50) of 7.25+/-0.02;
alpha(E) = 0.18). FR 173657 had no agonistic activity, exerted a non competitive
type of antagonism and was poorly reversible (lasting more than 5 h) from B(2)
receptor. In vivo, FR 173657 (given per os at 1 and 5 mg kg(-1), 1 h before the
experiment) antagonized the acute hypotensive effect of BK in anaesthetized
hamsters. It is concluded that aging and/or the presence of a congenital
cardiovascular disorder in hamsters are not associated with changes in the in
vitro aortic responses to either BK or desArg(9)BK.
PMID- 10780970
TI - Exogenous cholecystokinin-8 reduces vagal efferent nerve activity in rats through
CCK(A) receptors.
AB - It has been proposed that the vagus nerve plays a role in mediating
cholecystokinin-8 (CCK-8) effect on such gastric functions as motility, emptying
and gastric acid secretion. To examine the contribution of the efferent pathways
in realizing these effects, efferent mass activity in the ventral gastric vagal
nerve in Sprague-Dawley rats was recorded. Intravenous infusion of CCK-8 (0.1-1
nmol) suppressed the efferent activity. The effect of CCK-8 was significantly
reduced in animals with total subdiaphragmatic vagotomy in comparison to those
with partial vagotomy. Intravenous infusion of CCK(A) receptor antagonist L
364,718 (1-100x10(-6) g) blocked the response of vagal efferent activity to 0.1
nmol CCK-8, but the CCK(B) receptor antagonist L-365,260 (1-100x10(-6) g) did not
in the conditions of either partial or total vagotomy. Intracisternal infusion of
L-364,718 (1x10(-6) g) blocked the response of vagal efferent activity to 0.1
nmol CCK-8 i.v. Infusion of exogenous CCK-8 did not affect the activity of
supradiaphragmatic vagal afferents. The results suggest that the effect of
systemically administered CCK-8 on vagal efferent activity is mediated by both
peripherally (subdiaphragmatically) and centrally localized CCK(A) receptors.
PMID- 10780971
TI - Identification of the cytochrome P450 enzymes involved in the metabolism of
cisapride: in vitro studies of potential co-medication interactions.
AB - Cisapride is a prokinetic drug that is widely used to facilitate gastrointestinal
tract motility. Structurally, cisapride is a substituted piperidinyl benzamide
that interacts with 5-hydroxytryptamine-4 receptors and which is largely without
central depressant or antidopaminergic side-effects. The aims of this study were
to investigate the metabolism of cisapride in human liver microsomes and to
determine which cytochrome P-450 (CYP) isoenzyme(s) are involved in cisapride
biotransformation. Additionally, the effects of various drugs on the metabolism
of cisapride were investigated. The major in vitro metabolite of cisapride was
formed by oxidative N-dealkylation at the piperidine nitrogen, leading to the
production of norcisapride. By using competitive inhibition data, correlation
studies and heterologous expression systems, it was demonstrated that CYP3A4 was
the major CYP involved. CYP2A6 also contributed to the metabolism of cisapride,
albeit to a much lesser extent. The mean apparent K(m) against cisapride was
8.6+/-3.5 microM (n = 3). The peak plasma levels of cisapride under normal
clinical practice are approximately 0.17 microM; therefore it is unlikely that
cisapride would inhibit the metabolism of co-administered drugs. In this in vitro
study the inhibitory effects of 44 drugs were tested for any effect on cisapride
biotransformation. In conclusion, 34 of the drugs are unlikely to have a
clinically relevant interaction; however, the antidepressant nefazodone, the
macrolide antibiotic troleandomycin, the HIV-1 protease inhibitors ritonavir and
indinavir and the calcium channel blocker mibefradil inhibited the metabolism of
cisapride and these interactions are likely to be of clinical relevance.
Furthermore, the antimycotics ketoconazole, miconazole, hydroxy-itraconazole,
itraconazole and fluconazole, when administered orally or intravenously, would
inhibit cisapride metabolism.
PMID- 10780972
TI - Antihyperalgesic effects of delta opioid agonists in a rat model of chronic
inflammation.
AB - Opioid receptors in the brain activate descending pain pathways to inhibit the
nociceptive response to acute noxious stimuli. The aim of the present study was
to clarify the role of supraspinal opioid receptors in modulating the nociceptive
response to persistent inflammation in rats. Subcutaneous administration of 50
microl of complete Freund's Adjuvant (CFA) into the plantar surface of the
hindpaw induced a significant decrease in paw withdrawal latency to thermal
stimuli (P<0.01) at 24 h post-injection. Intracerebroventricular (i.c.v.)
administration of the mu opioid receptor agonists, DAMGO and morphine, and the
delta opioid receptor agonists, deltorphin II and SNC80, significantly reversed
the hyperalgesic response associated with peripheral inflammation in a dose
dependent manner (P<0.0001). The mu and delta agonists also significantly
attenuated the antinociceptive response to acute thermal stimulation in rats
(P<0.001). However, deltorphin II and SNC80 were less potent, and in the case of
SNC80 less efficacious, in modulating the response to acute thermal nociception
in comparison to hyperalgesia associated with persistent inflammation. These
results indicate that mu and delta opioid receptors in the brain modulate
descending pain pathways to attenuate the nociceptive response to acute thermal
stimuli in both normal and inflamed tissues. The heightened response to delta
agonists in the hyperalgesia model suggests that delta opioid receptors in the
brain are promising targets for the treatment of pain arising from chronic
inflammation.
PMID- 10780974
TI - Characterization of the ATPase released during sympathetic nerve stimulation of
the guinea-pig isolated vas deferens.
AB - The release of ATPase activity evoked by electrical field stimulation (EFS) (8
Hz, 25 s) was investigated in several tissues in which adenosine 5'-triphosphate
(ATP) acts as a neurotransmitter. Superfusate collected during EFS of sympathetic
nerves of the guinea-pig, rat and mouse isolated vas deferens and parasympathetic
nerves of the guinea-pig isolated urinary bladder contained ATPase activity. ATP
breakdown was fastest in superfusate collected from the guinea-pig isolated vas
deferens. However, EFS of the enteric nerves of the guinea-pig isolated taenia
coli did not release any detectable ATPase. The ATPase released from the guinea
pig isolated vas deferens metabolized ATP at similar rates at incubation
temperatures of 37 degrees C and 20 degrees C. Lineweaver-Burke analysis of the
initial rates of ATP hydrolysis gave a K(M) of 39 microM and a V(max) of 1039
pmol ATP metabolized min(-1) ml(-1) superfusate. 6-N,N-diethyl-D-beta,gamma
dibromomethyleneATP (ARL 67156), pyridoxalphosphate-6-azophenyl-2',4'-disulphonic
acid (PPADS) and pyridoxal-5'-phosphate (P-5-P) all inhibited the ATPase activity
in a concentration-dependent manner with a potency order of ARL 67156 = PPADS>P-5
P. In conclusion, EFS of several tissues in which ATP is a neurotransmitter
causes the release of an ATPase and activity is greatest in the guinea-pig vas
deferens. The enzyme has pharmacological and kinetic characteristics that are
similar to ectonucleoside triphosphate diphosphohydrolases.
PMID- 10780973
TI - Suppression of apoptosis by glucocorticoids in glomerular endothelial cells:
effects on proapoptotic pathways.
AB - Tumour necrosis factor-alpha (TNF-alpha)- and lipopolysaccharide (LPS)-induced
apoptosis of bovine glomerular endothelial cells is now recognized as an
important part in the pathogenesis of glomerulonephritis characterized by early
mitochondrial cytochrome c release, mitochondrial permeability transition, Bak
protein upregulation, Bcl-X(L) protein downregulation and caspase-3 activation.
Co-treatment of cells with 10 nM dexamethasone and TNF-alpha or LPS blocked
roughly 90% of apoptotic cell death in glomerular endothelial cells. The action
of glucocorticoids could be documented in that they prevented all apoptotic
markers such as DNA laddering, DNA fragmentation measured by the diphenylamine
assay as well as morphological alterations. To mechanistically elucidate the
action of glucocorticoids we evaluated whether glucocorticoids elicit a time
dependent effect. For dexamethasone, to maximally inhibit DNA fragmentation a
preincubation period was not required. Even if dexamethasone was supplemented 6 h
following TNF-alpha or LPS we observed a maximal inhibitory effect. Concerning
its influence on TNF-alpha and LPS signal transduction, we found that
dexamethasone only partially prevented cytochrome-c-release as a first sign of
apoptotic cell death but efficiently blocked mitochondrial permeability
transition. Moreover, TNF-alpha- and LPS-induced Bak upregulation, Bcl-X(L)
downregulation, and the activation of caspase-3-like proteases, measured
fluorometrically using DEVD-AMC and PARP cleavage, were efficiently blocked by
dexamethasone. We postulate that glucocorticoids exert their inhibitory action
upstream of the terminal death pathways but downstream of primary receptor
mediated signals by blocking pro-apoptotic signals pre- and/or post cytochrome c
release and mitochondrial signalling.
PMID- 10780975
TI - Neuropeptide Y regulates intracellular calcium through different signalling
pathways linked to a Y(1)-receptor in rat mesenteric small arteries.
AB - Simultaneous measurements of intracellular calcium concentration ([Ca(2+)](i))
and tension were performed to clarify whether the mechanisms which cause the
neuropeptide Y (NPY)-elicited contraction and potentiation of noradrenaline
contractions, and the NPY inhibition of forskolin responses are linked to a
single or different NPY receptor(s) in rat mesenteric small arteries. In resting
arteries, NPY moderately elevated [Ca(2+)](i) and tension. These effects were
antagonized by the selective Y(1) receptor antagonist, (R)-N(2)-(diphenacetyl)-N
[(4-hydroxyphenyl)methyl]-D-argininea mide (BIBP 3226) (apparent pK(B) values of
8.54+/-0.25 and 8.27+/-0.17, respectively). NPY (0.1 microM) caused a near 3 fold
increase in sensitivity to noradrenaline but did not significantly modify the
tension-[Ca(2+)](i) relationship for this agonist. BIBP 3226 competitively
antagonized the contractile response to NPY in arteries submaximally
preconstricted with noradrenaline (pA(2) 7.87+/-0.20). In arteries activated by
vasopressin, the adenylyl cyclase activator forskolin (3 microM) induced a
maximum relaxation and a return of [Ca(2+)](i) to resting levels. NPY completely
inhibited these effects. The contractile responses to NPY in arteries maximally
relaxed with either sodium nitroprusside (SNP) or nifedipine were not
significantly higher than those evoked by the peptide at resting tension, in
contrast to the contractions to NPY in forskolin-relaxed arteries. BIBP 3226
competitively antagonized the contraction to NPY in forskolin-relaxed arteries
with a pA(2) of 7.92+/-0.29. Electrical field stimulation (EFS) at 8-32 Hz caused
large contractions in arteries relaxed with either forskolin or noradrenaline in
the presence of phentolamine. These responses to EFS were inhibited by BIBP 3226.
Similar EFS in resting, non-activated arteries did not produce any response. The
present results suggest that different intracellular pathways are linked to a
single NPY Y(1) receptor in intact rat mesenteric small arteries, and provide
little support for involvement of other postjunctional NPY receptors in the
contractile responses to NPY. Neurally released NPY also seems to act through
Y(1) receptors, and may serve primarily as an inhibitor of vasodilatation.
PMID- 10780976
TI - Characterization of a novel nonpeptide vasopressin V(2)-agonist, OPC-51803, in
cells transfected human vasopressin receptor subtypes.
AB - We discovered the first nonpeptide arginine-vasopressin (AVP) V(2)-receptor
agonist, OPC-51803. Pharmacological properties of OPC-51803 were elucidated using
HeLa cells expressing human AVP receptor subtypes (V(2), V(1a) and V(1b)) and
compared with those of 1-desamino-8-D-arginine vasopressin (dDAVP), a peptide
V(2)-receptor agonist. OPC-51803 and dDAVP displaced [(3)H]-AVP binding to human
V(2)- and V(1a)-receptors with K(i) values of 91.9+/-10.8 nM (n = 6) and 3.12+/
0.38 nM (n = 6) for V(2)-receptors, and 819+/-39 nM (n = 6) and 41.5+/-9.9 nM (n
= 6) for V(1a)-receptors, indicating that OPC-51803 was about nine times more
selective for V(2)-receptors, similar to the selectivity of dDAVP. OPC-51803
scarcely displaced [(3)H]-AVP binding to human V(1b)-receptors even at 10(-4) M,
while dDAVP showed potent affinity to human V(1b)-receptors with the K(i) value
of 13.7+/-3.2 nM (n = 4). OPC-51803 concentration-dependently increased cyclic
adenosine 3', 5'-monophosphate (cyclic AMP) production in HeLa cells expressing
human V(2)-receptors with an EC(50) value of 189+/-14 nM (n = 6). The
concentration-response curve for cyclic AMP production induced by OPC-51803 was
shifted to the right in the presence of a V(2)-antagonist, OPC-31260. At 10(-5)
M, OPC-51803 did not increase the intracellular Ca(2+) concentration
([Ca(2+)](i)) in HeLa cells expressing human V(1a)-receptors. On the other hand,
dDAVP increased [Ca(2+)](i) in HeLa cells expressing human V(1a)- and V(1b)
receptors in a concentration-dependent fashion. From these results, OPC-51803 has
been confirmed to be the first nonpeptide agonist for human AVP V(2)-receptors
without agonistic activities for V(1a)- and V(1b)-receptors. OPC-51803 may be
useful for the treatment of AVP-deficient pathophysiological states and as a tool
for AVP researches.
PMID- 10780978
TI - Inhibition by various antipsychotic drugs of the G-protein-activated inwardly
rectifying K(+) (GIRK) channels expressed in xenopus oocytes.
AB - To investigate the effects of various chemical classes of antipsychotic drugs:
haloperidol, thioridazine, pimozide and clozapine, on the G-protein-activated
inwardly rectifying K(+) (GIRK) channels, we carried out Xenopus oocyte
functional assays with GIRK1 and GIRK2 mRNAs or GIRK1 and GIRK4 mRNAs. In oocytes
co-injected with GIRK1 and GIRK2 mRNAs, application of each of the various
antipsychotic drugs immediately caused a reduction of inward currents through the
basally active GIRK channels. These responses were not observed in the presence
of 3 mM Ba(2+), which blocks the GIRK channels. In addition, in uninjected
oocytes, none of the drugs tested produced any significant current response.
These results indicate that all the antipsychotic drugs tested inhibited the
brain-type GIRK1/2 heteromultimeric channels. Furthermore, similar results were
obtained in oocytes co-injected with GIRK1 and GIRK4 mRNAs, indicating that the
antipsychotic drugs also inhibited the cardiac-type GIRK1/4 heteromultimeric
channels. All the drugs tested inhibited, in a concentration-dependent manner,
both types of GIRK channels with varying degrees of potency and effectiveness at
micromolar concentrations. Only pimozide caused slight inhibition of these
channels at nanomolar concentrations. We conclude that the various antipsychotic
drugs acted as inhibitors at the brain-type and cardiac-type GIRK channels. Our
results suggest that inhibition of both types of GIRK channels by these drugs
underlies some of the side effects, in particular seizures and sinus tachycardia,
observed in clinical practice.
PMID- 10780977
TI - Effects of cannabinoid receptor agonists on neuronally-evoked contractions of
urinary bladder tissues isolated from rat, mouse, pig, dog, monkey and human.
AB - This study investigated the cannabinoid receptor, known to inhibit neuronally
evoked contractions of the mouse isolated urinary bladder, in bladder sections
isolated from mouse, rat, dog, pig non-human primate or human. The CB(1)-like
pharmacology of the cannabinoid receptor in mouse isolated bladder observed
previously was confirmed in this study by the rank order of agonist potencies: CP
55940>/=WIN 55212-2>HU 210>JWH 015>anandamide, the high affinity of the CB(1)
selective antagonist, SR 141716A (apparent pK(B) 8.7), and the low affinity of
the CB(2) antagonist, SR 144528 (apparent pK(B)<6.5). In these studies, SR
141716A (10-100 nM) significantly potentiated electrically-evoked contractions in
this tissue by an undetermined mechanism. A similar rank order of agonist
potencies was determined in rat isolated bladder sections (CP 55, 940> or =WIN
55212-2>JWH 015). In this tissue, the maximal inhibitory effect of all agonists
was lower than in the mouse bladder. Indeed, the effects of both HU 210 and
anandamide were too modest to quantify potency accurately. In the rat isolated
bladder, SR 141716A (30 nM) or SR 144528 (100 nM), reversed the inhibitory effect
of WIN 55212-2 (apparent pK(B) = 8.4 and 8.0, respectively) or JWH 015 (apparent
pK(B) = 8.2 and 7.4, respectively). These findings may demonstrate
pharmacological differences between the rat and mouse orthologues of the CB(1)
receptor. Alternatively, they may be attributed to a mixed population of CB(1)
and CB(2) receptors that jointly influence neurogenic contraction of the rat
bladder, but cannot be differentiated without more selective ligands. WIN 55212-2
had no effect on electrically-evoked contractions of bladder sections isolated
from dog, pig, cynomolgus monkey and human. These findings suggest that the
effect of cannabinoid agonists to inhibit neurogenic contraction of the mouse and
rat bladder is not conserved across all mammalian species.
PMID- 10780979
TI - FP-receptor mediated trophic effects of prostanoids in rat ventricular
cardiomyocytes.
AB - The aim of this study was to characterize the receptor subtype involved in
cardiac effects of prostanoids. For this purpose we determined in neonatal and
adult rat cardiomyocytes effects of prostanoids on inositol phosphate (InsP)
formation (assessed as accumulation of total [(3)H]-InsP's in myo-[(3)H]-inositol
pre-labelled cells) and on rate of protein synthesis (assessed as [(3)H]
phenylalanine incorporation), and on contractile force in left ventricular strips
of the rat heart. For comparison, effects of prostanoids on InsP-formation and
contractile force were determined in rat thoracic aorta, a classical TP-receptor
containing tissue. Prostanoid increased InsP-formation and rate of protein
synthesis in neonatal as well as adult rat cardiomyocytes; the order of potency
was in neonatal (PGF(2alpha)>PGD(2)> or =PGE(2)> or =U 46619>PGE(1)) and adult
(PGF(2alpha)>PGD(2)> or =PGE(2)>U 46619) rat cardiomyocytes well comparable.
Moreover, in electrically driven left ventricular strips PGF(2alpha) caused
positive inotropic effects (pD(2) 7.5) whereas U 46619 (up to 1 microM) was
uneffective. In contrast, in rat thoracic aorta U 46619 was about 100 times more
potent than PGF(2alpha) in increasing InsP-formation and contractile force. The
TP-receptor antagonist SQ 29548 only weakly antagonized prostanoid-induced
increases in rate of protein synthesis (pK(B) about 6) in rat cardiomyocytes but
was very potent (pK(B) about 8-9) in antagonizing prostanoid-induced increases in
InsP-formation and contractile force in rat aorta. We conclude that, in
cardiomyocytes of neonatal and adult rats, the prostanoid-receptor mediating
increases in InsP-formation and rate of protein synthesis is a FP-receptor.
Moreover, stimulation of these cardiac FP-receptors can mediate increases in
contractile force.
PMID- 10780980
TI - Contribution of B(2) receptors for bradykinin in arthus reaction-induced plasma
extravasation in wild-type or B(2) transgenic knockout mice.
AB - The aim of the present study was to investigate the contribution of bradykinin
(BK) B(1) and B(2) receptors in a model of type III hypersensitivity, the reverse
passive Arthus reaction (RPA), in wild-type mice and transgenic B(2) knockout
littermates. BK (10 microg mouse(-1)) or bovine serum albumin (0.5 mg mouse(-1))
induced a sustained Evans blue extravasation for more than 80 min in naive or
rabbit anti-bovine serum albumin-treated mice (RPA model), respectively. The
response to the two stimuli was prevented by the B(2) receptor antagonist, HOE
140, but not by [Leu(8)]desArg(9)-BK (B(1) receptor antagonist). In contrast to
the wild-type littermates, RPA and bradykinin were unable to trigger an increase
in plasma extravasation in B(2) knockout mice. Furthermore, endothelin-1 (5
microg mouse(-1)) and a selective NK-1 receptor agonist [Sar(9),Met (O(2))(11)]
SP (20 microg mouse(-1)), triggered a significant increase in peritoneal plasma
extravasation in both wild-type and B(2) knockout animals. A pretreatment with
indomethacin (200 microg mouse(-1)) significantly reduced the RPA-induced but not
the BK-induced increase in Evans blue extravasation. Furthermore, RPA, but not
BK, triggered a significant indomethacin-sensitive increase in peritoneal
prostaglandin E(2) content. Our results suggest a pivotal role for B(2) receptors
in the mechanism of plasma extravasation which occurs during the reverse passive
Arthus reaction in the mouse. Moreover, our results suggest an important
contribution of prostanoids in the plasma leakage mechanisms triggered by RPA but
not by bradykinin.
PMID- 10780981
TI - Enhanced relaxation of porcine coronary arteries after acute exposure to a
physiological level of 17beta-estradiol involves non-genomic mechanisms and the
cyclic AMP cascade.
AB - The present study extends our previous finding that the endothelium-independent
relaxation in porcine coronary artery rings is enhanced after short-term (20 min)
exposure to a physiological concentration (1 nM) of 17beta-estradiol and
demonstrates that this effect may be attributable to activation of the cyclic AMP
pathway. Isometric tension was recorded in isolated rings of porcine coronary
arteries. Relaxation by levcromakalim and sodium nitroprusside, but not
bradykinin and calcium ionophore A23187, were significantly potentiated following
20 min treatment with 1 nM 17beta-estradiol. This enhancing effect was
insensitive to the transcriptional and translational inhibitors, actinomycin D
and cycloheximide respectively and absent following repeated washing of the rings
prior to construction of relaxation-response curves. The potentiating actions of
1 nM 17beta-estradiol on endothelium-independent relaxation were mimicked by the
cyclic AMP analogue 8-Bromo-cyclic AMP and the protein kinase A activator Sp
cyclic AMPS but not by the cyclic GMP analogue 8-Bromo-cyclic GMP. The modulatory
effect of 17beta-estradiol was increased in the presence of the phosphodiesterase
inhibitor 3-isobutyl-1-methylxanthine. The cyclic AMP-dependent protein kinase A
inhibitor Rp-cyclic AMPS, but not the cyclic GMP antagonist Rp-8-Bromo-cyclic
GMPS, effectively inhibited the enhancing effects 1 M 17beta-estradiol had on the
relaxation responses of levcromakalim and sodium nitroprusside. These data
support our earlier findings that physiologically relevant concentrations of
17beta-estradiol can acutely modify vasorelaxation in vitro. Furthermore, we
report that this short-term effect of 17beta-estradiol on vasorelaxation appears
to be mediated via non-genomic pathways and involves the cyclic AMP cascade.
PMID- 10780982
TI - Comparison of the activity and disposition of the novel cholesterol absorption
inhibitor, SCH58235, and its glucuronide, SCH60663.
AB - Previous studies described the metabolism-based discovery of a potent, selective
inhibitor of intestinal absorption of cholesterol, SCH58235 (Ezetimibe). Here we
demonstrate that the phenolic glucuronide (SCH60663) of SCH58235, was more potent
at inhibiting cholesterol absorption in rats than SCH58235, when administered by
the intraduodenal route. To understand the increased potency of the glucuronide,
the metabolism and distribution of SCH58235 and SCH60663 were studied in bile
duct-cannulated rats. One minute after intraduodenal delivery of SCH58235,
significant levels of compound were detected in portal plasma; >95% was
glucuronidated, indicating that the intestine was metabolizing SCH58235 to its
glucuronide. When intraduodenally delivered as SCH58235, the compound was
glucuronidated, moved through the intestinal wall, into portal plasma, through
the liver, and into bile. However, when delivered as SCH60663, >95% of the
compound remained in the intestinal lumen and wall, which may explain its
increased potency. Significant inhibition of cholesterol absorption and
glucuronidation of SCH58235 occurred when SCH58235 was intravenously injected
into bile duct-cannulated rats. Autoradiographic analysis demonstrated that drug
related material was located throughout the intestinal villi, but concentrated in
the villus tip. These data indicate that (a) SCH58235 is rapidly metabolized in
the intestine to its glucuronide; (b) once glucuronidated, the dose is excreted
in the bile, thereby delivering drug related material back to the site of action
and (c) the glucuronide is more potent than the parent possibly because it
localizes to the intestine. Taken together, these data may explain the potency of
SCH58235 in the rat (ID(50) = 0.0015 mg kg(-1)) and rhesus monkey (ID(50) =
0.0005 mg kg(-1)).
PMID- 10780983
TI - Investigations into pharmacological antagonism of general anaesthesia.
AB - The effects of convulsant drugs, and of thyrotropin releasing hormone (TRH), were
examined on the general anaesthetic actions of ketamine, ethanol, pentobarbitone
and propofol in mice. The aim was to investigate the possibility of selective
antagonism, which, if seen, would provide information about the mechanism of the
anaesthesia. The general anaesthetic effects of ketamine were unaffected by
bicuculline; antagonism was seen with 4-aminopyridine and significant
potentiation with 300 mg kg(-1) NMDLA (N-methyl-DL-aspartate). The calcium
agonist, Bay K 8644, potentiated the anaesthesia produced by ketamine and
antagonism of such anaesthesia was seen with TRH. A small, but significant,
antagonism of the general anaesthesia produced by ethanol was seen with
bicuculline, and a small, significant, potentiation with 4-aminopyridine. There
was an antagonist effect of TRH, but no effect of NMDLA. Potentiation of the
anaesthetic effects of pentobarbitone was seen with NMDLA and with 4
aminopyridine and the lower dose of bicuculline (2.7 mg kg(-1)) also caused
potentiation. There was no significant change in the ED(50) value for
pentobarbitone anaesthesia with TRH. Bicuculline did not alter the anaesthetic
actions of propofol, while potentiation was seen with NMDLA and 4-aminopyridine.
TRH had no significant effect on propofol anaesthetic, but Bay K 8644 at 1 mg kg(
1) significantly potentiated the anaesthesia. These results suggest that
potentiation of GABA(A) transmission or inhibition of NMDA receptor-mediated
transmission do not appear to play a major role in the production of general
anaesthesia by the agents used.
PMID- 10780984
TI - Role of kynurenines in the neurotoxic actions of kainic acid.
AB - The neurotoxic actions of kainic acid can be partly suppressed by antagonists
acting at N-methyl-D-aspartate (NMDA) receptors. The present study examined the
possible role of endogenous components of the kynurenine pathway to this
phenomenon. Administration of kainate (2 nmols) into the hippocampus of
anaesthetized rats produced damage in the CA1 and CA3 regions. The involvement of
NMDA receptors was confirmed by the ability of dizocilpine (1 mg kg(-1)) to
reduce cell loss in the CA1 region from 92 to 42%. The co-administration of m
nitrobenzoylalanine (20 nmols into the hippocampus), an inhibitor of kynurenine
hydroxylase and kynureninase, together with a systemic injection of the compound
(100 mg kg(-1), i.p.), afforded some protection against kainate, reducing cell
loss from 91 to 48%. Protection was not exerted against damage by quinolinic acid
or NMDA, excluding a direct interaction between m-nitrobenzoylalanine and NMDA
receptors. The protective effect of m-nitrobenzoylalanine was not prevented by
glycine, which would be expected to reverse protection caused by an elevation in
the levels of endogenous kynurenic acid, arguing against a major role for
increased levels of kynurenic acid. The results indicate that inhibition of the
kynurenine pathway offers protection against kainate-induced damage. One possible
mechanism for the protection is that an increased production of quinolinic acid
in the brain, possibly from glial cells and macrophages activated by the initial
kainate insult, normally contributes to the local activation of NMDA receptors
and thus to kainate-induced cerebral insults. This generation of endogenous
quinolinic acid would be suppressed by m-nitrobenzoylalanine.
PMID- 10780985
TI - Antagonism of nicotinic receptors of rat chromaffin cells by N,N, N-trimethyl-1
(4-trans-stilbenoxy)-2-propylammonium iodide: a patch clamp and ligand binding
study.
AB - The effect of the oxystilbene derivative F3 was tested on nAChRs of whole-cell
patch-clamped rat chromaffin cells in vitro and of rat adrenal gland membranes
using (125)I-epibatidine. F3 (30 nM) rapidly and reversibly blocked inward
currents generated by pulse applications of nicotine, shifting the dose-response
curve to the right in a parallel fashion without changing the maximum response.
The action of F3 was voltage insensitive and not due to altered current reversal
potential. The R isomer of F3 was more potent (IC(50) = 350+/-30 nM) than its S
enantiomer (IC(50) = 1.5+/-0.3 microM). Nicotine-evoked currents were insensitive
to 10 microM alpha-bungarotoxin. Equi-amplitude currents evoked by nicotine or
epibatidine were similarly antagonized by R-F3 in a reversible fashion.
Epibatidine-evoked currents readily produced receptor desensitization. Adrenal
membranes specifically bound (125)I-epibatidine with a single population of
binding sites endowed with high affinity (K(D) = 159 pM) and B(max) of 6.5+/-1.3
fmol mg(-1) of protein. (125)I-epibatidine binding was specifically displaced by
cytisine (K(i) = 68 nM) or ACh (K(i) = 348 nM). F3 specifically displaced (125)I
epibatidine binding although with lower affinity (K(i) = 29.6 microM) than in
electrophysiological experiments. (125)I-epibatidine binding to rat adrenal
tissue was insensitive to alpha-bungarotoxin which readily antagonized (125)I
epibatidine binding to bovine adrenal tissue. The present results suggest that F3
is a relatively potent and apparently competitive antagonist of nAChRs on rat
chromaffin cells. Since previous studies have indicated that F3 targets different
subtypes on chick neuronal tissue, it appears that nAChRs display interspecies
differences to be considered for drug development studies.
PMID- 10780986
TI - Release of dopamine from human neocortex nerve terminals evoked by different
stimuli involving extra- and intraterminal calcium.
AB - The release of [(3)H]-dopamine ([(3)H]-DA) from human neocortex nerve terminals
was studied in synaptosomes prepared from brain specimens removed in neurosurgery
and exposed during superfusion to different releasing stimuli. Treatment with 15
mM KCl, 100 microM 4-aminopyridine, 1 microM ionomycin or 30 mM caffeine elicited
almost identical overflows of tritium. Removal of external Ca(2+) ions abolished
the overflow evoked by K(+) or ionomycin and largely prevented that caused by 4
aminopyridine; the overflow evoked by caffeine was completely independent of
external Ca(2+). Exposure of synaptosomes to 25 microM of the broad spectrum
calcium channel blocker CdCl(2) strongly inhibited the 4-aminopyridine-induced
tritium overflow while that evoked by ionomycin remained unaffected. The Ca(2+)
chelator, 1,2-bis-(2-aminophenoxy)ethane-N,N,N',N' tetraacetic acid (BAPTA),
reduced significantly the K(+)- and the caffeine-induced tritium overflow. The
effect of caffeine was attenuated by exposure to the ryanodine receptor blocker
dantrolene or when the membrane-impermeant inositol trisphosphate receptor
antagonist, heparin, was entrapped into synaptosomes; the combined treatment with
dantrolene and heparin abolished the release elicited by caffeine. Tetanus toxin,
entrapped into human neocortex synaptosomes to avoid prolonged incubation,
inhibited in a concentration-dependent manner the K(+)- or the 4-aminopyridine
evoked tritium overflow; in contrast, the release stimulated by ionomycin and by
caffeine were both totally insensitive to the same concentrations of tetanus
toxin. Western blot analysis showed about 50% reduction of the content of the
vesicular protein, synaptobrevin, in synaptosomes poisoned with tetanus toxin. In
conclusion, the release of dopamine from human neocortex nerve terminals can be
triggered by Ca(2+) ions originating from various sources. It seems that stimuli
not leading to activation of voltage-sensitive Ca(2+) channels elicit Ca(2+)
dependent, probably exocytotic, release that is insensitive to tetanus toxin.
PMID- 10780987
TI - Characterization and distribution of prolactin releasing peptide (PrRP) binding
sites in the rat--evidence for a novel binding site subtype in cardiac and
skeletal muscle.
AB - Prolactin releasing peptide (PrRP) was recently purified from bovine hypothalamus
and binds to the orphan receptor, UHR-1. We examined the distribution and
kinetics of (125)I-PrRP binding in rat tissues together with molecular
characterization by chemical cross-linking and Northern blotting. In this study
(125)I-PrRP binding showed specificity and rapid association and dissociation.
Specific binding was found in membranes from rat tissues including brain
(hypothalamus, medulla oblongata and cerebellum), pituitary, heart, soleus
muscle, adipose tissue, kidney, adrenal gland, testis and small intestine. In
hypothalamus, pituitary, heart and soleus competition analysis indicated only one
class of binding site in each tissue. Binding affinity for PrRP (IC(50)) and
binding site density (B(max)) respectively were 5.2+/-0.9 nM and 674+/-97 fmol mg
protein(-1) in hypothalamus (n = 5), 1.4+/-0.6 nM and 541+/-126 fmol mg protein(
1) in pituitary (n = 3), 6.6+/-0.7 nM and 628+/-74 fmol mg protein(-1) in heart
(n = 4) and 9.8+/-0.9 nM and 677+/-121 fmol mg protein(-1) in soleus muscle (n =
4). Analysis of (125)I-PrRP-binding site complexes by chemical cross-linking
showed a binding site M(r) of 69,000 in hypothalamus and 41,000 in heart and
soleus. Northern analysis of polyA(+) RNA from hypothalamus showed a 4.2 kb band
as expected for UHR-1, but heart and soleus showed a 4.8 kb band. Taken together
these results indicate that there may be different subtypes of PrRP binding sites
in rat tissues which may differ from UHR-1.
PMID- 10780988
TI - Allosteric modulators affect the efficacy of partial agonists for recombinant
GABA(A) receptors.
AB - Different alpha subunits of human gamma-aminobutyric acid type A (GABA(A))
receptors were transiently expressed together with beta(3) and gamma(2) subunits
in Xenopus oocytes to examine the interactions of various GABA(A) agonists and
representative allosteric modulators. Chloride currents elicited by agonists were
measured using two electrode voltage clamp electrophysiology. Where compounds
behaved as full agonists, i.e. GABA on all subtypes and 4,5,6, 7
tetrahydroisoxazolo [5,4-c]pyridin-3-ol (THIP) on alpha2beta(3)gamma(2) GABA(A)
receptors, agonist concentration-response curves were shifted to the left by the
benzodiazepine full agonist chlordiazepoxide and the anticonvulsant loreclezole,
or to the right by the inverse agonist 6, 7-dimethoxy-4-ethyl-beta-carboline-3
carboxylic acid methyl ester (DMCM), with no effect on the maximal currents
(I(max)). In contrast, maximal responses for different partial GABA(A) agonists
on all benzodiazepine-sensitive alpha(x)beta(3)gamma(2) GABA(A) receptors were
enhanced by chlordiazepoxide. I(max) values for piperidine-4-sulphonic acid (P4S)
on alpha(1)beta(3)gamma(2), THIP on alpha(3)beta(3)gamma(2), and 5-(4
piperidyl)isothiazol-3-ol (thio-4-PIOL) on alpha(2)beta(3)gamma(2) and
alpha(5)beta(3)gamma(2) GABA(A) receptors were increased by chlordiazepoxide,
while that for P4S on alpha(1)beta(3)gamma(2) receptors was decreased by DMCM.
The I(max) values for partial agonists were also enhanced by pentobarbitone, the
neurosteroid allopregnanolone and loreclezole irrespective of receptor subtype or
the nature of the partial agonist. In the light of models of ligand-gated ion
channel receptor activation we suggest two possible mechanisms of action for the
effects of allosteric modulators on partial agonist receptor activation: either
selective modulation of agonist affinity for the open/closed state, or direct
modulation of the gating process itself.
PMID- 10780989
TI - Mepyramine but not cimetidine or clobenpropit blocks pertussis toxin-induced
histamine sensitization in rats.
AB - The effects of pertussis toxin (PT) and the role of histaminergic H(1), H(2) and
H(3) receptor blockade on the actions of histamine on blood pressure, heart rate,
blood gas values, and mortality were studied in anaesthetized rats. Four days
after treatment with PT, histamine dose-dependently decreased mean arterial blood
pressure (MAP) and PT enhanced the histamine-induced decrease in MAP. In the PT
but not in the inactivated PT (IPT) or saline treated group three out of six
animals died after the highest dose of histamine (300 mg kg(-1), i.v.) In order
to determine the type of histamine receptor that mediates HS, 4 days after PT the
selective antagonists mepyramine (H(1)), cimetidine (H(2)) and clobenpropit
(H(3)) were administered 20 min before the challenge with histamine. Mepyramine
completely inhibited both the enhanced histamine-induced decrease in MAP and
mortality brought about by PT. Cimetidine and clobenpropit had no protective
effects, but rather enhanced the histamine-induced mortality elicited by PT. The
present study shows that PT caused HS in rats which is primarily mediated via
H(1) and secondarily via H(2) and H(3) receptors. These results are considered to
be a first step in the elucidation of the mechanism(s) of the HS test used in the
quality control of acellular pertussis vaccine.
PMID- 10780990
TI - Proteinase-activated receptor-2 (PAR-2): regulation of salivary and pancreatic
exocrine secretion in vivo in rats and mice.
AB - Proteinase-activated receptor-2 (PAR-2) is expressed throughout the
gastrointestinal tract including the pancreas, and may be involved in digestive
functions. The aim of our study was to evaluate a potential role for PAR-2 in
regulating salivary and pancreatic exocrine secretion in vivo. PAR-2-activating
peptides (PAR-2-APs), but not selective PAR-1-APs, administered intravenously,
increased salivary secretion in the mouse or rat; this effect of the PAR-2-APs
was unaffected by atropine, phentolamine, propranolol or indomethacin. Secretion
(amylase) by rat parotid gland slices in vitro was also stimulated by PAR-2-APs
and trypsin, but not by activation of other PARs. PAR-2-APs, administered to rats
in vivo, caused a prompt effect on pancreatic exocrine secretion. PAR-2 mRNA,
known to be present in pancreatic tissue, was also detected in parotid tissue.
Our results indicate that in addition to a potential role in regulating
cardiovascular and respiratory functions, PAR-2 may also play a general role in
vivo for the direct regulation of glandular exocrine secretion.
PMID- 10780991
TI - Inverse agonism at G protein-coupled receptors: (patho)physiological relevance
and implications for drug discovery.
PMID- 10780993
TI - In vivo effects of the 5-HT(6) antagonist SB-271046 on striatal and frontal
cortex extracellular concentrations of noradrenaline, dopamine, 5-HT, glutamate
and aspartate.
AB - Although the 5-HT(6) receptor subtype was identified some 5 years ago, very
little is known about its function within the brain. Here we demonstrate, for the
first time, the neurochemical effects of a selective 5-HT(6) receptor ligand.
Using in vivo microdialysis in the freely moving rat, we evaluated the effects of
the selective 5-HT(6) receptor antagonist SB-271046 by simultaneous measurement
of 5-hydroxytryptamine (5-HT), dopamine (DA), noradrenaline (NA), glutamate and
aspartate from the striatum and frontal cortex. SB-271046 did not alter basal
levels of 5-HT, DA and NA in either brain region. Similarly, there was no change
basal levels of either of the excitatory amino acids within the striatum. In
contrast, administration of SB-271046 (10 mg kg(-1) s.c.) produced a significant
(P<0.05), tetrodotoxin-dependent, increase in extracellular levels of both
glutamate and aspartate within the frontal cortex, reaching maximum values of
375.4+/-82.3 and 215. 3+/-62.1% of preinjection values, respectively.
PMID- 10780992
TI - The muscarinic M(5) receptor: a silent or emerging subtype?
PMID- 10780994
TI - Involvement of sensory nerves in vasodilator responses to acetylcholine and
potassium ions in rat hepatic artery.
AB - In the presence of ouabain (1 mM), acetylcholine and KCl (5 mM) evoked
endothelium-independent relaxations in rat hepatic arteries. Treatment with
capsaicin (10 microM), scopolamine (1 microM) or CGRP(8 - 37) (3 microM)
prevented these relaxations. Acetylcholine-induced relaxations in intact arterial
segments in the presence of indomethacin (10 microM) and N(G)-nitro-L-arginine
(0.3 mM) were only partially inhibited by ouabain plus BaCl(2) (30 microM).
However, ouabain plus BaCl(2) almost abolished such relaxations in capsaicin-pre
treated preparations. In arteries without endothelium, the neurosecretagogue
alpha-latrotoxin (1 nM) induced complete relaxations, which were abolished by
CGRP(8 - 37) or pre-treatment with capsaicin. alpha-Latrotoxin also induced a
smooth muscle hyperpolarization (12+/-2 mV), which was abolished by CGRP(8 - 37).
The ability of ouabain to disclose a CGRP-mediated neurogenic relaxation must be
considered when this agent is used as a pharmacological tool. The results further
suggest that CGRP is a nerve-derived hyperpolarizing factor in the rat hepatic
artery.
PMID- 10780995
TI - Neuroleptics ameliorate phencyclidine-induced impairments of short-term memory.
AB - 1. Phencyclidine (PCP), a non-competitive NMDA-receptor antagonist, is able to
induce schizophrenia-like symptoms in animals and in humans. It is known that
schizophrenic patients have deficits in memory processes. 2. Therefore, it was
investigated whether subchronic pulsatile or continuous application of 5.0 mg kg(
1) PCP over 5 days induce short-term memory deficits in holeboard learning and
the action of two different neuroleptics on this behavioural test. 3. First, an
impairment in the holeboard task was described when the animals were tested 24 h
after the last application but not after 15 min or 1 h after the last injection.
Secondly, the influence of haloperidol and risperidone on the PCP-induced short
term memory changes was tested. 4. The combined application of PCP and
risperidone led to a complete antagonism of the short-term deficits, but the
combined treatment with haloperidol was accompanied by a partial abolishment of
the PCP-induced deficits. 5. PCP led to an upregulation of the glutamate binding
sites in striatum and nucleus accumbens whereas the D(2) binding sites were
reduced in striatum. The D(1) binding sites seem to be unchanged. The receptor
protein expression of glutamate receptors mGluR1, GluR2, GluR5/7 and NMDAR1 were
not modified in response to PCP treatment. 6. The determination of a
subpopulation of GABAergic interneurons shows a decrease of the cells within the
CA3 of the hippocampal formation. 7. These findings indicate that PCP induced
impairments in short term memory can be detected by holeboard learning and may
provide an interesting tool for the search of new neuroleptics.
PMID- 10780996
TI - Central injection of nitric oxide synthase inhibitors increases peripheral
interleukin-6 and serum amyloid A: involvement of adrenaline from adrenal
medulla.
AB - 1. Accumulating evidence suggests that plasma levels of interleukin-6 (IL-6), a
major cytokine stimulating the synthesis of acute phase proteins, are intimately
regulated by the central nervous system (CNS). 2. In the present study, effects
of intracerebroventricular (i.c. v) injection of N(G)-nitro-L-arginine methyl
ester (L-NAME) or 7-nitroindazole, nitric oxide synthase (NOS) inhibitors, on
plasma IL-6 levels and peripheral IL-6 mRNA expression were examined in mice. 3.
L-NAME (0.1 - 2 microg per mouse i.c.v.) and 7-nitroindazole (0.2 - 2 microg per
mouse i.c.v.) induced a dose-dependent increase in plasma IL-6 levels and a
subsequent increase in circulating serum amyloid A, a liver acute-phase protein.
In contrast, an intraperitoneal (i.p.) injection of L-NAME up to the dose of 25
microg per mouse had no effect. 4. Pretreatment with yohimbine (alpha(2)
adrenergic antagonist; 1 mg kg(-1) i.p.), or ICI-118,551 (beta(2)-adrenergic
antagonist; 2 mg kg(-1) i.p.), but not with prazosin (alpha(1)-adrenergic
antagonist; 1 mg kg(-1) i.p.), nor betaxolol (beta(1)-adrenergic antagonist; 2 mg
kg(-1) i.p.), significantly inhibited the central L-NAME-induced plasma IL-6
levels. 5. I.c.v. (50 microg per mouse) or i.p. (100 mg kg(-1)) pretreatment with
6-hydroxydopamine had no effect on central L-NAME-induced plasma IL-6 levels.
However, intrathecal (i.t.) pretreatment with 6-hydroxydopamine (20 microg per
mouse) markedly inhibited central L-NAME-induced plasma IL-6 levels. Both
yohimbine (1.5 microg per mouse i.t.) and ICI-118,551 (1.5 microg per mouse i.
t.) were effective in inhibition of central L-NAME-induced plasma IL-6 levels. 6.
There was an elevation of base-line plasma IL-6 levels in adrenalectomized
animals. The adrenalectomy-enhanced levels were not further increased by central
L-NAME. 7. L-NAME (2 microg per mouse i.c.v.) induced an increase in IL-6 mRNA
expression in liver, spleen, and lymph node. 8. These results suggest that NOS
activity in the brain tonically down-regulates peripheral IL-6 by inhibiting
adrenaline release from the adrenal medulla.
PMID- 10780997
TI - Neurokinin B- and specific tachykinin NK(3) receptor agonists-induced airway
hyperresponsiveness in the guinea-pig.
AB - 1. The aim of this study was to determine whether neurokinin B (NKB) or specific
agonists of tachykinin NK(3) receptors, [MePhe(7)]NKB and senktide, were able to
induce airway hyperresponsiveness in guinea-pigs. The effects of these compounds
were compared to those of substance P (SP), neurokinin A (NKA) and the
preferential tachykinin NK(1) ([Sar(9), Met(0(2))(11)]SP) or NK(2)
([betaAla(8)]NKA (4-10)) receptor agonists. 2. In guinea-pigs pretreated with
phosphoramidon (10(-4) M aerosol for 10 min) and salbutamol (8.7x10(-3) M for 10
min), all tachykinins administrated by aerosol (3x10(-7) to 10(-4) M) induced
airway hyperresponsiveness 24 h later, displayed by an exaggerated response to
the bronchoconstrictor effect of acetylcholine (i.v.). The rank order of potency
was: [betaAla(8)]NKA (4
10)>NKA=NKB=senktide=[MePhe(7)]NKB=[Sar(9),Met(0(2))(11)]SP>SP. 3. Airway
hyperresponsiveness induced by [MePhe(7)]NKB was prevented by the tachykinin
NK(3) (SR 142801) and NK(2) (SR 48968) receptor antagonists. 4.
Bronchoconstriction induced by tachykinins administered by aerosol was also
determined. SP, NKA, NKB and the tachykinin NK(1) and NK(2) receptor agonist
induced bronchoconstriction. The rank order of potency was: NKA=[betaAla(8)]NKA
(4-10)>NKB=SP=[Sar(9), Met(0(2))(11)]SP. Under similar conditions, and for
concentrations which induce airway hyperresponsiveness, senktide and
[MePhe(7)]NKB failed to induce bronchoconstriction. 5. It is concluded that
tachykinin NK(3)-receptor stimulation can induce airway hyperresponsiveness and
that this effect is not related to the ability of tachykinins to induce
bronchoconstriction.
PMID- 10780998
TI - Enhanced expression of haem oxygenase-1 by nitric oxide and antiinflammatory
drugs in NIH 3T3 fibroblasts.
AB - 1. Haem oxygenase-1 (HO-1) can exert protective effects against oxidative stress
and inflammation. Fibroblasts participate in inflammatory responses where they
produce high levels of prostaglandins (PGs) and nitric oxide (NO). However,
little is known of the presence of HO-1 in these cells and the possible
interactions among these pathways. Incubation of cells with NO donors, spermine
nonoate (SPNO) and S-nitroso-N-acetylpenicillamine (SNAP), induced a dose- and
time-dependent expression of HO-1 protein. 2. NO donors increased basal PGE(2)
release although they reduced PGE(2) accumulated in the medium and cyclo
oxygenase (COX) activity when cells were stimulated with lipopolysaccharide
(LPS). COX-2 protein was weakly induced by SPNO in basal conditions and in the
presence of LPS a synergy for HO-1 and COX-2 protein expression was observed. 3.
Our results indicate that reactive oxygen species participate in the inductive
effect of NO donors or LPS on HO-1 expression, whereas endogenous NO production
may play a role in the mechanism of the synergy exhibited by SPNO and LPS on HO-1
and COX-2 expression. In this system, zinc protoporphyrin IX did not affect
nitrite levels but reduced COX activity. 4. The selective COX-2 inhibitors
SC58125 and NS398 as well as the non-selective COX inhibitor, indomethacin,
strongly reduced PGE(2) synthesis and showed a synergy with NO donors in HO-1 and
COX-2 induction. Addition of PGE(2) had no effect, suggesting a mechanism
independent of PGs formation. 5. In inflammatory conditions a number of factors
could cooperate to induce HO-1 and COX-2, with a positive regulation by COX
inhibitors.
PMID- 10780999
TI - Characterization of the binding of two novel glycine site antagonists to cloned
NMDA receptors: evidence for two pharmacological classes of antagonists.
AB - The potency of two novel glycine site antagonists, GV150,526A and GV196,771A, was
assessed by their ability to inhibit the binding of [(3)H]-MDL105,519 to cell
homogenates prepared from mammalian cells transfected with either NR1-1a, NR1-2a,
NR1-1a/NR2A, NR1-1a/NR2B, NR1-1a/NR2C or NR1-1a/NR2D NMDA receptor clones. The
inhibition constants (K(i)s) for GV150,526A displacement of [(3)H]-MDL105,519
binding to either NR1-1a or NR1-2a expressed alone were not significantly
different and were best fit by a one-site binding model. GV150,526A inhibition to
NR1-1a/NR2 combinations was best fit by a two-site model with the NR1-1a/NR2C
having an approximate 2 - 4 fold lower affinity compared to other NR1-1a/NR2
receptors. The K(i)s for GV196,771A displacement of [(3)H]-MDL105,519 binding to
NR1-1a, NR1-2a and all NR1-1a/NR2 combinations was best fit by a two-site binding
model. There was no significant difference between the K(i)s for the binding to
NR1-1a and NR1-2a; NR1-1a/NR2A receptors had an approximate 4 fold lower affinity
for GV196,771A compared to other NR1-1a/NR2 combinations. The K(i)s for both
GV150, 526A and GV196,771A for the inhibition of [(3)H]-MDL105,519 binding to
membranes prepared from adult rat forebrain were determined and compared to the
values obtained for binding to cloned NMDA receptors. The K(i)s for a series of
glycine site ligands with diverse chemical structures were also determined for
the inhibition of [(3)H]-MDL105,519 binding to NR1-1a/NR2A receptors. L689,560
displayed similar binding characteristics to GV150,526A. It is suggested that
glycine site antagonists may be divided into two classes based on their ability
to distinguish between NR1 and NR1/NR2 receptors with respect to binding curve
characteristics.
PMID- 10781000
TI - Evidence for a M(1) muscarinic receptor on the endothelium of human pulmonary
veins.
AB - 1. To characterize the muscarinic receptors on human pulmonary veins associated
with the acetylcholine (ACh)-induced relaxation, isolated venous and arterial
preparations were pre-contracted with noradrenaline (10 microM) and were
subsequently challenged with ACh in the absence or presence of selective
muscarinic antagonists. 2. ACh relaxed venous preparations derived from human
lung with a pD(2) value of 5.82+/-0.09 (n=16). In venous preparations where the
endothelium had been removed, the ACh relaxations were abolished (n=4). ACh
relaxed arterial preparations with a pD(2) value of 7. 06+/-0.14 (n=5). 3.
Atropine (1 microM), the non selective antagonist for muscarinic receptors,
inhibited ACh-induced relaxations in human pulmonary veins. The affinity value
(pK(B) value) for atropine was: 8.64+/-0.10 (n=5). The selective muscarinic
antagonists (darifenacin (M(3)), himbacine (M(2),M(4)), methoctramine (M(2)) and
pFHHSiD (M(1),M(3))) also inhibited ACh-induced relaxations in venous
preparations. The pK(B) values obtained for these antagonists were not those
predicted for the involvement of M(2 - 5) receptors in the ACh-induced relaxation
in human pulmonary veins. 4. The pK(B) value for darifenacin (1 microM) was
significantly greater in human pulmonary arterial (8.63+/-0.14) than in venous
(7.41+/-0.20) preparations derived from three lung samples. 5. In human pulmonary
veins, the pK(B) values for pirenzepine (0.5 and 1 microM), a selective
antagonist for M(1) receptors, were: 7.89+/-0.24 (n=7) and 8.18+/-0.22 (n=5),
respectively. In the venous preparations, the pK(B) values derived from the
functional studies with all the different muscarinic antagonists used were
correlated (r=0.89; P=0.04; slope=0.78) with the affinity values (pK(i) values)
previously published for human cloned m1 receptors in CHO cells. 6. These results
suggest that the relaxations induced by ACh are due to the activation of M(1)
receptors on endothelial cells in isolated human pulmonary veins.
PMID- 10781001
TI - Smooth muscle layer-dependent distribution of 5-hydroxytryptamine(7) receptor in
the porcine myometrium.
AB - 1. To analyse the mechanisms of muscle layer-dependent inhibition of porcine
myometrial contractility by 5-hydroxytryptamine (5-HT), the effects of 5-HT, 5
carboxamidotryptamine(5-CT), 5-methoxytryptamine (5-MeOT), forskolin and cyclic
adenosine 3', 5'-monophosphate (cyclic AMP) analogues on spontaneous and
stimulant-induced contractions were examined in longitudinal (LM) and circular
muscles (CM). In addition, accumulation of cyclic AMP by 5-HT and distribution of
5-HT(7) receptors in LM and CM layers were compared using biochemical and
molecular approaches. 2. 5-HT receptor agonists inhibited the spontaneous
contractions of LM and CM (5-CT>5-HT>5-MeOT), but CM was more sensitive than was
LM. The inhibition by the agonists was antagonized by methiothepin (100 nM). 3.
Carbachol-, high-K(+)-, histamine- and Ca(2+)-induced contractions were inhibited
by 5-HT with different responses (CM>LM). Even in the presence of 3-isobutyl-1
methylxanthine (IBMX), the inhibition by 5-HT in the CM was still more
conspicuous than that in the LM. 4. Compared with the CM, the inhibition of
spontaneous contraction by forskolin, dibutyryl-cyclic AMP and 8-bromo-cyclic AMP
was marked in the LM. 5. 5-HT (1 nM - 1 microM) increased the cyclic AMP in both
muscle layers, but the increment in the CM was higher than that in the LM whether
IBMX was present or not. 6. LM and CM layers contained a single class of [(3)H]-5
CT binding sites with a similar K(d) value (0.21 - 0.24 nM). However, B(max) (5
HT(7) receptor concentration) in the CM (120.6 fmol mg(-1) protein) was higher
than that in the LM (30.4 fmol mg(-1) protein). 7. The molecular study (reverse
transcription polymerase chain reaction) demonstrated the expression of 5-HT(7)
receptor mRNA in the CM was higher than that in the LM. 8. These results suggest
that the muscle layer-dependent difference in inhibition by 5-HT is not
restricted to spontaneous contraction but applies to various contractions in the
porcine myometrium. Different inhibition of the contractility by 5-HT is caused
by muscle layer-related accumulation of cyclic AMP (CM>LM), due to smooth muscle
layer dependent distribution (CM>LM) of 5-HT(7) receptors.
PMID- 10781002
TI - Evaluation of iNOS-dependent and independent mechanisms of the microvascular
permeability change induced by lipopolysaccharide.
AB - 1. Subcutaneous injection of lipopolysaccharide (LPS) increases plasma leakage in
mouse skin. Pretreatment with LPS conditions mice tolerant to the LPS-induced
plasma leakage. Nitric oxide (NO) has been suggested to be involved in these LPS
effects. A specific role of inducible NO synthase (iNOS) was investigated in the
LPS-induced plasma leakage using iNOS deficient mice. 2. Plasma leakage in mouse
skin was measured by the local accumulation of Pontamine sky blue at the site of
subcutaneous injection of LPS (Sal. typhimurium). LPS (100 - 400 microg site(-1))
produced a dose-related increase in dye leakage in both iNOS deficient and wild
type mice with about 40% less dye leakage in iNOS deficient mice. 3. Indomethacin
(5 mg kg(-1)), N-[-2-cyclohexyloxy]-4-nitrophenyl methanesulphonamide (NS-398) (1
mg kg(-1)), diphenhydramine (10 mg kg(-1)) and anti-TNF-alpha antibody (dilution
1 : 400, 10 ml kg(-1)) inhibited the LPS-induced dye leakage in both iNOS
deficient and wild-type mice, whereas N(G)-nitro-L-arginine methyl ester (L-NAME)
(10 mg kg(-1)) or aminoguanidine (10 mg kg(-1)) inhibited that in wild-type but
not in iNOS deficient mice. 4. Pretreatment with LPS (0.15 mg kg(-1) i.p.) 4 h
before decreased the LPS-induced dye leakage in wild-type but not in iNOS
deficient mice. LPS pretreatment increased serum corticosterone levels in both
mice, while it increased the serum nitrate/nitrite levels in wild-type but not in
iNOS deficient mice. 5. These studies indicate that an increase in vascular
permeability induced by LPS is mediated by NO produced by iNOS, eicosanoids,
histamine and TNF-alpha. The tolerance against LPS-induced vascular permeability
change may be mediated by iNOS induction but not by an increased release of
endogenous corticosteroids.
PMID- 10781003
TI - Correlation of leukocyte adhesiveness, adhesion molecule expression and leukocyte
induced contraction following balloon angioplasty.
AB - 1. The aim of this study was to examine the changes in leukocyte adhesion and
leukocyte-induced contraction in balloon-injured rabbit subclavian artery and to
correlate these changes with vessel morphology and expression of adhesion
molecules on the injured arteries. 2. Rabbits were anaesthetized and their left
subclavian arteries were injured by balloon inflation and withdrawal followed by
sacrifice at 2, 24, 48 h or 8 days after injury. The left and right subclavian
arteries were removed and leukocytes were isolated from autologous rabbit blood.
Leukocyte-induced contraction was measured in 5-HT precontracted artery rings and
leukocyte adhesion was measured using (51)Cr-labelled leukocytes.
Immunocytochemistry using paraffin-embedded tissue was employed to detect changes
in the expression of adhesion molecules on injured arteries. 3. Autologous
leukocytes caused a contraction of rabbit subclavian artery rings, which was
prevented by L-NAME (10(-3) M). Balloon-induced injury abolished the contractile
response to leukocytes, which correlated with loss of carbachol-induced
relaxation 4. Balloon injury markedly enhanced the adhesiveness of the subclavian
artery for leukocytes, most notably at 24 and 48 h after injury (1.7 and 1.8 fold
respectively). Increased leukocyte adhesion at these two time points correlated
with an upregulation of E-selectin, P-selectin and VCAM-1 expression on the
remaining endothelium of the injured artery. 5. Vessel morphology revealed that
balloon inflation had induced an infiltration of inflammatory cells into the
vessel wall, the greatest increase being seen at 24 h after injury. 6. It is
concluded that an increase in the expression of E-selectin, P-selectin and VCAM-1
following balloon-induced injury leads to enhanced leukocyte adhesion and
migration into the injured vessel.
PMID- 10781004
TI - Identification of the adenylyl cyclase-activating 5-hydroxytryptamine receptor
subtypes expressed in the rat submandibular gland.
AB - 1. Serotonin (5-hydroxytryptamine, 5-HT) has been shown to increase cyclic AMP
production in dispersed cell aggregates from the major salivary glands of the
rat. The goal of the present study was to identify the 5-HT receptor subtypes
that mediate these effects in rat submandibular glands (SMG). 2. Among the 5-HT
receptor subtypes identified in the rat, 5-HT(4(a,b)), 5-HT(6) and 5-HT(7(a,b,c))
activate adenylyl cyclase (AC). We used subtype specific primers to screen rat
SMG by reverse transcription-PCR. Results indicate the presence of mRNA for 5
HT(4(b)) and 5-HT(7(a)) but not for 5-HT(4(a)), 5-HT(6) and 5-HT(7(b,c)). 3. In
dispersed SMG cells, 5-carboxyamidotryptamine (5-CT), a 5-HT(7) receptor agonist,
stimulated cyclic AMP synthesis with higher potency (EC(50)=27+/-5 nM) but lower
efficacy than 5-HT, suggesting a 5-HT(7) component and an additional component in
the response to 5-HT. The 5-HT(7) contribution was further supported by
antagonism of the 5-CT effect by metergoline, a 5-HT(7) antagonist, which
exhibited an affinity (K(i)=50 nM) similar to that obtained at the cloned 5-HT(7)
receptor. 4. In the presence of a maximally effective concentration of 5-CT, 5-HT
produced an additional increase in cyclic AMP production that was inhibited by
the 5-HT(4) receptor antagonist, GR113808, suggesting that the second component
of cyclic AMP production is mediated by 5-HT(4) receptors. 5. These findings
indicate the presence in rat SMG of both 5-HT(4(b)) and 5-HT(7(a)) receptors
positively coupled to AC.
PMID- 10781005
TI - The role of nitric oxide in the responses of the ovine digital artery to
vasoactive agents and modification of these responses by endotoxin and cytokines.
AB - 1. Laminitis, an important cause of lameness in domestic ungulates, occurs as a
result of altered digital perfusion. Endotoxin and cytokines may mediate the
vascular derangements observed through alterations in nitric oxide production. In
this study, the vascular responses of the isolated ovine digital artery were
examined and the influence of endotoxin and cytokines investigated. 2. Neither
removal of the endothelium nor incubation with N(G)-nitro-L-arginine methyl ester
(L-NAME, 300 microM) altered the response to phenylephrine (PE, 1 nM to 300
microM). Indomethacin (10 microM) decreased PE log EC(50) from -6.22+/-0.08 to
6.55+/-0.07. Acetylcholine (1 nM to 1 mM) and bradykinin (BK, 100 pM to 3 microM)
induced endothelium-dependent relaxation. Bradykinin-induced relaxation was
reduced by L-NAME, E(max) falling from -61.7+/-7.4 to -34.0+/-2.1%. Addition of
indomethacin further reduced BK E(max) to -9.6+/-2.8%. Sodium nitroprusside (1 nM
to 300 microM) produced endothelium-independent relaxation that was unaffected by
L-NAME or indomethacin. 3. Following a 6 h incubation with endotoxin (3 microml(
1)), arterial responses to PE and BK did not differ from polymyxin B-treated
controls (10 microg ml(-1)). Arteries incubated for 6 h with interferon-gamma
(IFN-gamma, 10 ng ml(-1)) and tumour necrosis factor-alpha (TNF-alpha, 5 ng ml(
1)) exhibited greater relaxation to BK (E(max)-50.0+/-5.1%) than polymyxin B
treated controls (E(max)-33.1+/-4.0%), but did not differ in their response to
PE. 4. Prolonged incubation (16 h) with endotoxin (3 microg ml(-1)) did not alter
the response to PE, however incubation with IFN-gamma (10 ng ml(-1)), TNF-alpha
(5 ng ml(-1)) and interleukin-1beta (20 ng ml(-1)) for 16 h increased PE log
EC(50) from -6.44+/-0.09 to -6. 10+/-0.11. 5. Nitric oxide is an important
mediator of endothelium-dependent relaxation in ovine digital arteries but does
not modulate PE-induced vasoconstriction. Incubation with cytokines decreased the
sensitivity of digital arteries to PE.
PMID- 10781006
TI - Impaired vascular sensitivity to nitric oxide in the coronary microvasculature
after endotoxaemia.
AB - 1. The effects of endotoxaemia on coronary vasodilator responses to bradykinin
(BK), sodium nitroprusside (SNP) and nicardipine were investigated in the rat
isolated heart perfused at constant flow ex vivo. 2. Dose-dependent reductions in
coronary perfusion pressure reaching a maximum of 56+/-3 and 57+/-5 mmHg were
observed for BK and SNP respectively. The BK response was biphasic, consisting of
a rapid dilator response that was insensitive to N(G)nitro-L-arginine methyl
ester (L-NAME, 0.1 mM) and a second slower component whose duration was
attenuated by L-NAME. 3. Hearts obtained from rats treated with endotoxin (2.5 mg
kg(-1), i.p.) for 2 or 6 h had increased basal coronary perfusion pressure and
reduced vasodilator responses to BK or SNP. Dilator responses to nicardipine were
not affected by endotoxin treatment. In vitro perfusion of hearts from endotoxin
treated rats with L-NAME (0.1 mM) restored SNP responses to control values. 4.
Treatment with dexamethasone (1 mg kg(-1)), 1 h before endotoxin did not alter
the endotoxin-induced impairment of dilator responses to BK or SNP. 5. These
results show that coronary microvascular responses are altered following
endotoxin exposure. Endotoxin results in increased coronary microvascular tone
despite induction of NO synthase and inhibits the dilator response to BK and SNP,
vasodilators that act via the release of NO. Responses to SNP in endotoxin
treated hearts were restored to control values in the presence of L-NAME
suggesting that enhanced endogenous NO synthesis might saturate guanylate cyclase
resulting in reduced response to NO donors. The reduced response to vasodilators
and increased coronary resistance might be important in determining the response
of the coronary circulation to systemic inflammation and infection.
PMID- 10781007
TI - Evidence for the involvement of peroxynitrite in ischaemic preconditioning in rat
isolated hearts.
AB - 1. The aim of this study was to investigate the involvement of peroxynitrite,
reactive metabolite originating from nitric oxide and superoxide, in
preconditioning of the ischaemic myocardium in rat isolated hearts. 2. Isolated
hearts perfused with Krebs-Henseleit solution were preconditioned either by 3 min
of coronary artery occlusion (CAO) or by peroxynitrite administration at three
different concentrations (0.1, 1, 10 microM) for 3 min, followed by 10 min
reperfusion and 30 min of CAO. Peroxynitrite, at 1 microM concentration,
decreased the incidence of VT from 100% (n=14) to 62% (n=13) and abolished the
occurrence of VF (50% in the control group). 3. N-2-mercaptopropionylglycine
(MPG, 1 microM - 10 mM) produced a concentration-dependent inhibition of
peroxynitrite signals in luminol chemiluminescence and 67+/-1% inhibition was
observed at 100 microM (n=7). MPG (at 300 microM, n=7) added to the perfusate 10
min prior to ischaemic preconditioning or peroxynitrite infusion and maintained
until CAO, significantly reversed the beneficial effects of the ischaemic and
peroxynitrite-treated groups. MPG administration in the peroxynitrite-treated
group increased the incidence of VT from 62% (n=13) to 100% (n=10) and total VF
from 0% (n=0) to 67% (n=10). Similarly, MPG elevated the incidence of VT from 50%
(n=10) to 100% (n=8) in the ischaemic preconditioned group. On its own, MPG did
not affect the severity of cardiac arrhythmias. 4. These results suggest that
endogenously produced peroxynitrite plays a significant role in the
antiarrhythmic effect of ischaemic preconditioning in the rat isolated hearts.
PMID- 10781008
TI - Cisplatin-induced early and delayed emesis in the pigeon.
AB - 1. Intravenously injected cisplatin at a dose of 4 mg kg(-1) induced early and
delayed emesis in all pigeons without occurrence of lethality during a 72 h
observation period. The early emetic response occurred with a latency of 81.3+/
8.0 min (n=15) and reached a peak at 2 - 3 h, and decreased gradually within 8 h
after injection. Then the delayed emetic response, whose peak was found between
10 to 23 h, lasted up to 48 h. The emetic response markedly declined after 48 h.
2. Reserpine markedly reduced monoamine levels in both brain and intestine and
completely abolished the early and delayed emesis. Dexamethasone markedly reduced
not only the early but also the delayed emetic responses. p-Chlorophenylalanine
decreased the level of serotonin in brain and intestine without affecting
noradrenaline and dopamine and partly reduced the early emetic response, but did
not affect delayed emesis. 3. Bilateral vagotomy prolonged the latency time to
the onset of early emesis, and reduced the emetic responses in both the early and
delayed phases. 4. The above results suggest that the cisplatin-induced early
emesis in the pigeon is partially mediated via the vagal nerve and reserpine
sensitive monoaminergic systems including the serotonergic system; the delayed
emesis is associated with monoaminergic but not the serotonergic systems.
PMID- 10781009
TI - Ecto-nucleotide pyrophosphatase modulates the purinoceptor-mediated signal
transduction and is inhibited by purinoceptor antagonists.
AB - 1. The effect of ecto-nucleotide pyrophosphatase (ecto-NPPase; EC 3.6.1. 9) on
the ATP- and ADP-mediated receptor activation was studied in rat C6 glioma cells.
The P2-purinoceptor antagonists pyridoxalphosphate-6-azophenyl-2',4'-disulphonic
acid (PPADS) and reactive blue (RB2) are potent inhibitors (IC(50)=12+/-3 microM)
of the latter enzyme. 4,4'-diisothiocyanatostilbene-2,2' disulfonic acid (DIDS),
5'-phosphoadenosine 3'-phosphate (PAP) and suramin were less potent inhibitors
with an IC(50) of 22+/-4, 36+/-7 and 72+/-11 microM respectively. 2. P1
purinoceptor antagonists CGS 15943, cyclo-pentyl theophylline (CTP) and
theophylline did not affect the activity of the ecto-NPPase. 3. ATP- and ADP
mediated P2Y(1)-like receptor activation inhibited the (-)-isoproterenol-induced
increase of intracellular cyclic AMP concentration. PPADS, an ineffective P2Y
antagonist in C6, potentiated the ATP and ADP effect approximately 3 fold due to
inhibition of nucleotide hydrolysis by the ecto-NPPase. 4. We conclude that ecto
NPPase has a modulator effect on purinoceptor-mediated signalling in C6 glioma
cell cultures.
PMID- 10781011
TI - Behavioural and physiological effects induced by an infusion of antisense to
alpha(2D)-adrenoceptors in the rat.
AB - 1. The aim of this study was to investigate the behavioural and physiological
effects of an i.c.v. infusion of antisense oligonucleotide to the alpha(2D)
adrenoceptor subtype. Behavioural and physiological parameters were monitored for
2 days before the infusion, throughout the 3-day infusion period and for 3 days
following the end of the infusion. 2. The antisense infusion resulted in a
significant increase in behavioural activity characterized by increased
locomotion and grooming scores. Behavioural activity scores of rats treated with
antisense to alpha(2D)-adrenoceptors were significantly higher than those of rats
treated with vehicle (H(2)O) or the mismatch toxicity control on day 4 and day 5
and, significantly higher than vehicle controls on day 6. 3. Body weight gain was
significantly reduced in the antisense-treated rats at the end of the study
compared to the vehicle (34%) and mismatch groups (30%), although daily food and
water intakes were not significantly different at any time point. 4. Pupil
diameters of rats infused with antisense to alpha(2D)-adrenoceptors were
significantly greater than those of animals treated either with vehicle or
mismatch oligonucleotide on day 5 of the study. On day 6, the pupil diameters of
these animals were still significantly greater than the mismatch group. 5. In
conclusion, an i.c.v. infusion of antisense to the alpha(2D)-adrenoceptor induced
behavioural activation in rats, increased pupil diameter and reduced total weight
gain. These effects were specific to the antisense-treated group and were fully
reversed post-infusion.
PMID- 10781010
TI - Activation of I(2)-imidazoline receptors enhances supraspinal morphine analgesia
in mice: a model to detect agonist and antagonist activities at these receptors.
AB - This work investigates the receptor acted upon by imidazoline compounds in the
modulation of morphine analgesia. The effects of highly selective imidazoline
ligands on the supraspinal antinociception induced by morphine in mice were
determined. 2. Intracerebroventricular (i.c.v.) or subcutaneous (s.c.)
administration of ligands selective for the I(2)-imidazoline receptor, 2-BFI, LSL
60101, LSL 61122 and aganodine, and the non selective ligand agmatine, increased
morphine antinociception in a dose-dependent manner. Neither moxonidine, a mixed
I(1)-imidazoline and alpha(2)-adrenoceptor agonist, RX821002, a potent alpha(2)
adrenoceptor antagonist that displays low affinity at I(2)-imidazoline receptors,
nor the selective non-imidazoline alpha(2)-adrenoceptor antagonist RS-15385-197,
modified the analgesic responses to morphine. 3. Administration of pertussis
toxin (0.25 microg per mouse, i.c.v.) 6 days before the analgesic test blocked
the ability of the I(2)-imidazoline ligands to potentiate morphine
antinociception. 4. The increased effect of morphine induced by I(2)-imidazoline
ligands (agonists) was completely reversed by idazoxan and BU 224. Identical
results were obtained with IBI, which alkylates I(2)-imidazoline binding sites.
Thus, both agonist and antagonist properties of imidazoline ligands at the I(2)
imidazoline receptors were observed. 5. Pre-treatment (30 min) with deprenyl, an
irreversible inhibitor of monoamine oxidase B (IMAO-B), produced an increase of
morphine antinociception. Clorgyline, an irreversible IMAO-A, given 30 min before
morphine did not alter the effect of the opioid. At longer intervals (24 h) a
single dose of either clorgyline or deprenyl reduced the density of I(2)
imidazoline receptors and prevented the I(2)-mediated potentiation of morphine
analgesia. 6. These results demonstrate functional interaction between I(2)
imidazoline and opioid receptors. The involvement of G(i)-G(o) transducer
proteins in this modulatory effect is also suggested.
PMID- 10781012
TI - Role of uptake inhibition and autoreceptor activation in the control of 5-HT
release in the frontal cortex and dorsal hippocampus of the rat.
AB - 1. Using brain microdialysis, we compared the relative role of 5
hydroxytryptamine (5-HT; serotonin) blockade and somatodendritic 5-HT(1A) and/or
terminal 5-HT(1B) autoreceptor activation in the control of 5-HT output. 2.
Fluoxetine (10 mg kg(-1) i.p.) doubled the 5-HT output in frontal cortex and
dorsal hippocampus. The 5-HT(1A) receptor antagonist WAY 100635, (0.3 mg kg(-1)
s.c.) potentiated the effect of fluoxetine only in frontal cortex (to
approximately 500 % of baseline). 3. Methiothepin (10 mg kg(-1) s.c.) further
enhanced the 5-HT rise induced by fluoxetine+WAY 100635, to 835+/-179% in frontal
cortex and 456+/-24% in dorsal hippocampus. Locally applied, methiothepin
potentiated the fluoxetine-induced 5-HT rise more in the former area. 4. The
selective 5-HT(1B) receptor antagonist SB-224289 (4 mg kg(-1) i.p.) enhanced the
effect of fluoxetine (10 mg kg(-1) i.p.) in both areas. As with methiothepin, SB
224289 (4 mg kg(-1) i.p.) further enhanced the 5-HT increase produced by
fluoxetine+WAY 100635 more in frontal cortex (613+/-134%) than in dorsal
hippocampus (353+/-59%). 5. Locally applied, fluoxetine (10 - 300 microM;
EC(50)=28 - 29 microM) and citalopram (1 - 30 microM; EC(50)=1.0 - 1.4 microM)
increased the 5-HT output two to three times more in frontal cortex than in
dorsal hippocampus. These data suggest that the comparable 5-HT increase produced
by systemic fluoxetine in frontal cortex and dorsal hippocampus results from a
greater effect of reuptake blockade in frontal cortex that is offset by a greater
autoreceptor-mediated inhibition of 5-HT release. As a result, 5-HT autoreceptor
antagonists preferentially potentiate the effect of fluoxetine in frontal cortex.
PMID- 10781013
TI - Apparent species differences in the kinetic properties of P2X(7) receptors.
AB - 1. Apparent species differences in the responses of recombinant P2X(7) receptors
to repeated application of 2'- and 3'-O-(4-benzoylbenzoyl)-ATP (BzATP) have been
investigated. 2. Repeated application of 100 microM BzATP resulted in a
progressive increase in current magnitude (current growth) at mouse and human,
but not rat P2X(7) receptors. 3. Current growth was thought to reflect
progressive dilation of the P2X(7) ion-channel to a pore permeable to large
molecules (MW<900), suggesting that channel dilation was not occurring at the rat
P2X(7) receptor. However, 100 microM BzATP produced a rapid influx of YO-PRO-1
(MW375) in cells expressing rat or human P2X(7) receptors. 4. There were,
however, species differences in agonist potency such that 100 microM BzATP was a
supra-maximal concentration at rat, but not human or mouse, P2X(7) receptors.
Importantly, when sub-maximal concentrations of BzATP or ATP were examined,
current growth occurred at rat P2X(7) receptors. 5. The rate of current growth
and YO-PRO-1 accumulation increased with agonist concentration and appeared more
rapid at rat and human, than at mouse P2X(7) receptors. 6. The potency of BzATP
and ATP was 1.5 - 10 fold lower in naive cells than in cells repeatedly exposed
to ATP. 7. This study demonstrates that current growth occurs at mouse, rat and
human P2X(7) receptors but only when using sub-maximal concentrations of agonist.
Previously, current growth was thought to reflect the progressive increase in
pore diameter of the P2X(7) receptor ion channel, however, the results of this
study suggest a progressive increase in agonist potency may also contribute.
PMID- 10781014
TI - Involvement of the cyclic AMP system in the switch from tolerance into
supersensitivity to the antinociceptive effect of the opioid sufentanil.
AB - 1. We have previously demonstrated that chronic and simultaneous treatment of
rats with the mu-opioid receptor agonist sufentanil and the Ca(2+) channel
blocker nimodipine, not only prevented tolerance development, but the animals
became supersensitive to the antinociceptive effect of the opioid. The focus of
the present work was to determine the possible involvement of cross interactions
between the adenylyl cyclase pathway and L-type voltage-sensitive Ca(2+)
channels, in modulating the switch from opioid tolerance into supersensitivity.
2. The modulatory effect of sufentanil on adenylyl cyclase activity was
determined by measuring cyclic AMP production in slices from the cortex of rats
rendered tolerant or supersensitive to the antinociceptive effect of the opioid.
Tolerance was induced by chronic infusion of sufentanil, at a rate of 2 microg h(
1), for 7 days. Supersensitivity was induced by concurrent infusion of sufentanil
(2 microg h(-1)) and nimodipine (1 microg h(-1)) for 7 days. Antinociception was
evaluated by the tail-flick test. 3. Tolerance to the analgesic effect of
sufentanil was associated with a significant reduction in the response of
adenylyl cyclase to forskolin. Furthermore, the effect of the opioid on forskolin
induced cyclic AMP accumulation was abolished. On the other hand,
supersensitivity to the analgesic effect of the opioid was associated with an
increase in both, the adenylyl cyclase response to forskolin, and the opioid
inhibition of cyclic AMP production. 4. We suggest that sustained L-type Ca(2+)
channel blockade may result in changes in the adenylyl cyclase effector system
triggered by mu-opioid receptor activation, leading to the switch from opioid
tolerance into supersensitivity.
PMID- 10781015
TI - Heterogeneous mechanisms of endothelium-dependent relaxation for thrombin and
peptide activators of protease-activated receptor-1 in porcine isolated coronary
artery.
AB - 1. Mechanisms of protease-activated receptor-1 (PAR1)- and PAR2-induced
relaxation were investigated in pre-contracted porcine coronary artery ring
preparations. 2. Thrombin (0.01 - 0.3 u ml(-1)) and the PAR1-activating peptide
SFLLRN (0.1 - 10 microM) caused concentration- and endothelium-dependent
relaxation. pEC(50)s (-log u ml(-1) for enzymes, -log M for peptides) and maximum
relaxations (R(max), %) for thrombin were 1.8+/-0.1 and 93.5+/-2.8% respectively,
and for SFLLRN 6.8+/-0.1 and 90.8+/-1.3%. Similar concentration- and endothelium
dependent relaxations occurred with trypsin (pEC(50) 2.3+/-0.2; R(max) 94.1+/
1.9%) and the PAR2-activating peptide SLIGRL (pEC(50) 6.5+/-0.2; R(max) 92.4+/
1.6%). 3. Relaxations to thrombin, SFLLRN, trypsin and SLIGRL were significantly
inhibited (P<0.05) to similar extents by the nitric oxide (NO) synthase inhibitor
N(G)-nitro-L-arginine (L-NOARG; 100 microM) and the NO scavenger oxyhaemoglobin
(20 microM), both separately and in combination. 4. In the presence of the L-type
voltage-operated calcium channel (L-VOCC) inhibitor nifedipine (0.3 microM), K(+)
(67 mM) abolished the L-NOARG-resistant relaxations to thrombin, SFLLRN, trypsin
and SLIGRL. However, nifedipine alone significantly (P<0.05) reduced the pEC(50)
(1.5+/-0.1) and R(max) (77.5+/-7.0%) for thrombin but had no effect on
relaxations to SFLLRN, trypsin or SLIGRL. Furthermore, L-NOARG-resistant
relaxations to thrombin were abolished by nifedipine, whereas relaxations to
SFLLRN, trypsin or SLIGRL were not further inhibited by combined treatment with
nifedipine and L-NOARG, than they were with L-NOARG treatment alone. 5. Similar
selective inhibition of the L-NOARG-resistant relaxation to thrombin, but not
SFLLRN, occurred with verapamil (1 microM) and diltiazem (3 microM). 6. Our
results suggest heterogeneous mechanisms in the NO-independent relaxation to
thrombin and peptide activators of PAR1 in the porcine coronary artery.
PMID- 10781017
TI - Geoffrey H. Gold (1949-2000)
PMID- 10781016
TI - CGRP and adrenomedullin binding correlates with transcript levels for calcitonin
receptor-like receptor (CRLR) and receptor activity modifying proteins (RAMPs) in
rat tissues.
AB - 1. Putative receptors for CGRP and adrenomedullin have been investigated in the
rat. Calcitonin Receptor-Like Receptor (CRLR), in combination with Receptor
Activity Modifying Proteins (RAMPs) is hypothesized to bind either CGRP or
adrenomedullin. The receptors known as RDC1 and L1 have also been shown to bind
CGRP and adrenomedullin respectively. 2. In this study it is shown that rat CRLR
cDNA specifies a CGRP receptor when co-transfected with RAMP-1 cDNA and an
adrenomedullin receptor when co-transfected with either RAMP-2 or RAMP-3 cDNA in
human embryonic kidney 293 cells. 3. CRLR, RAMP, RCD1 and L1 mRNA levels and CGRP
and adrenomedullin receptor densities have been measured and correlated with each
other in eight rat tissues selected for their distinctive patterns of CGRP and
adrenomedullin binding. 4. The data are consistent with the predictions of the
CRLR/RAMP model. CGRP binding correlates well with RAMP-1 mRNA levels (R=1.0,
P=0.007), adrenomedullin binding shows a tendency to vary with RAMP-2 mRNA levels
(R=0.85, P=0.14) and total binding is correlated with CRLR mRNA levels (R=0.94,
P=0.03). The data do not support the hypothesis that RDC1 and L1 account for the
majority of CGRP and adrenomedullin binding respectively.
PMID- 10781018
TI - Sexually dimorphic and isomorphic glomeruli in the antennal lobes of the sphinx
moth Manduca sexta.
AB - Antennal lobes of adult male and female Manduca sexta were compared in order to
investigate the nature and extent of sexual dimorphism of the primary olfactory
center of this lepidopteran species. Complete identification of the glomeruli led
to the conclusion that all female glomeruli have homologous male counterparts.
Thus, there is no sex-specific glomerulus present in one sex and absent in the
other. Sexual dimorphism (i.e. glomeruli present but morphologically different in
males and females), however, does occur in the three glomeruli composing the male
macroglomerular complex. The female homologs of this complex consist of two
previously identified 'large female glomeruli' and one newly identified normal
sized glomerulus. The lateral and medial large female glomeruli are interpreted
to be homologous to the first two macroglomerular-complex glomeruli-the cumulus
and toroid 1. The third male component, the toroid 2, was tentatively identified
with a normal-sized spheroidal glomerulus of the female, called here the 'small
female glomerulus'. The 60 'ordinary' glomeruli that make up the rest of the
glomerular neuropil were found to be homologous in males and females, with the
exception of two anomalous (or uncertain) glomeruli. Some variations in relative
position and size observed among those glomeruli suggest a diffuse, quantitative
kind of sexual dimorphism.
PMID- 10781019
TI - Synergism among ternary mixtures of fourteen sweeteners.
AB - The purpose of the present study was to determine the degree of synergism of
sweet taste among ternary mixtures of 14 sweeteners. A trained panel evaluated
ternary mixtures of 14 sweeteners varying in chemical structure and type. The
ternary mixtures that were tested were limited to those in which the compounds
comprising the mixture were synergistic in binary combinations, according to an
earlier study. All sweeteners in the ternary mixtures were isointense with 2%
sucrose, according to a previously developed formulae. Each self-mixture was also
tested (e.g. 2% sucrose + 2% sucrose + 2% sucrose). The triad with the highest
mean sweetness intensity rating was alitame-neohesperidin dihydrochalcone
rebaudioside-A (10.8). This represents an increase of 99.4% when compared with
the average of the self-mixtures. While this is greater than the maximum of 74%
increase found for binary mixtures, more dyadic combinations of sweeteners tested
previously exhibited synergism than ternary combinations tested here. However,
most ternary mixtures were synergistic (significantly greater than the average of
the three self-mixtures) to some degree.
PMID- 10781020
TI - The plant sesquiterpene germacrene D specifically activates a major type of
antennal receptor neuron of the tobacco budworm moth Heliothis virescens.
AB - Plants release hundreds of volatiles that are important in interactions with
insects or other organisms. However, knowledge is scarce as to which of the
compounds are detected by the organism's olfactory receptor neurons. In the
present study, single receptor neurons on the antennae of the tobacco budworm
moth, Heliothis virescens, were screened for their sensitivities to naturally
produced plant volatiles by the use of gas chromatography linked to
electrophysiological recordings from single cells (GC-SCR). Plant volatiles,
collected by aeration of host and non-host plants, were tested on each receptor
neuron via parallel GC-columns. Thus, simultaneous recordings of the gas
chromatogram and the neuron responses to each component were obtained. One type
of receptor neuron, appearing in 80% of all experiments, responded with high
sensitivity and selectivity to one particular component, present in host as well
as non-host mixtures. The component, identified as a sesquiterpene hydrocarbon by
linked gas chromatography-mass spectrometry, was isolated from a sesquiterpene
fraction of cubebe oil and identified by NMR as germacrene D. The purified
compound was then re-tested via gas chromatography on the same receptor neuron
type, verifying the identification. A weaker response to another sesquiterpene
hydrocarbon was also recorded.
PMID- 10781021
TI - Effects of various taste stimuli on heart rate in humans.
AB - Relationships between taste stimuli and heart rate were evaluated in 29 healthy
university students. The test solutions were sucrose, NaCl, citric acid, quinine
HCl and monosodium glutamate (MSG). Heart rate increased by 7.1-13.6% for all the
taste stimuli after use as compared with pre-stimuli values. The maximum
increases in heart rate came approximately 25 s after the taste stimuli. After
the increases, heart rate returned to pre-stimuli levels after between 80 and 100
s. Heart rate reached its maximum with citric acid. Recovery from the heart-rate
increase was more delayed for quinine-HCl and MSG than for the other stimuli.
Except for sucrose, increases in heart rate and the hedonic scale values of the
taste solutions showed significant negative correlation. These findings show that
the taste stimuli solutions increased the heart rate and that the increase
differed with the concentration and taste solution used.
PMID- 10781022
TI - Analysis of the molecular basis for octanal interactions in the expressed rat 17
olfactory receptor.
AB - Expression studies have shown that the rat I7 olfactory receptor (OR-I7) responds
preferentially to the aldehyde n-octanal. We wished to predict which residues in
OR-I7 bind octanal and how the biophysical properties of these residues determine
the receptor's odor selectivity. Building on our previous work on aldehyde
interactions in olfactory receptors, we constructed a molecular model of OR-I7
based on the 7.5 A resolution three-dimensional map of rhodopsin. Octanal was
automatically docked in the model. The results predicted an odor-binding pocket
approximately 10 A from the extracellular surface, in a location similar to the
epinephrine-binding pocket of the beta-adrenergic receptor and the odor-binding
pocket of a previous olfactory receptor model. A lysine on TM4 and an aspartate
on TM5 interacted with the aldehyde moiety of octanal. Hydrophobic residues
formed Van der Waals contacts with the hydrocarbon portion of octanal. We docked
related odor compounds and found that the predicted affinities compared favorably
with experimental results. We also tested a number of amino acid substitutions in
order to predict their effects on octanal affinity and provide leads for future
experimental work.
PMID- 10781023
TI - Effects of anion substitution on hydration behavior and water uptake of the red
spotted toad, Bufo punctatus: is there an anion paradox in amphibian skin?
AB - Amphibians absorb water osmotically across their skins and rely on chemosensory
information from the skin to assess the suitability of hydration sources. The
time spent with skin in contact with a moist surface provides a quantitative
measure of their ability to perceive the ionic and osmotic properties of aqueous
solutions. Dehydrated toads given hyperosmotic (250 mM) solutions of NaCl or Na
gluconate showed significantly longer periods of hydration behavior on the
gluconate solution, but they lost water osmotically when immersed in either
solution. Similarly, dehydrated toads given 250 mM solutions of NaCl, Na-acetate,
Na-phosphate or Na-gluconate showed a progressively greater length of hydration
time on solutions with the larger mol. wt anions. These results are consistent
with the chemosensory phenomenon previously described in mammalian tongue as
'anion paradox'. On dilute (50 mM) solutions of NaCl or Na-gluconate, the
hydration time was not different between anions, despite toads gaining water more
rapidly when immersed in dilute NaCl than in Na-gluconate solutions. The
differing behavioral results with hyperosmotic and hypoosmotic salt solutions
suggest that chemosensory transduction through toad skin involves both
transcellular and paracellular pathways.
PMID- 10781024
TI - Suppression of S-methylglutathione-induced tentacle ball formation by peptides
and nullification of the suppression by TGF-beta in Hydra.
AB - Tentacle ball formation (TBF) in Hydra elicited by S-methylglutathione (GSM) was
modulated by a number of biologically active peptides. Hydra fed on Artemia,
which had been hatched in a common salt solution supplemented with LiCl and
ZnCl(2), easily induced TBF in response to GSM after pretreatment with trypsin.
After Hydra were treated with 100 pg/ml trypsin for 10 min, the response to GSM
(TBF) was sensitively suppressed by acidic fibroblast growth factor and other
biologically active peptides for >10 h. Various peptides, but not transforming
growth factor beta (TGF-beta), suppressed GSM-induced TBF in a specific pattern
for each peptide. However, TGF-beta was unique in that it did not suppress the
response to GSM, but nullified the suppressive effect of other peptides. Only
active TGF-beta nullified the suppressive effect of the peptides, and the latent
form of TGF-beta neither suppressed GSM-induced TBF nor nullified the suppressive
effect of other peptides. Members of the TGF-beta family suppressed GSM-induced
TBF. These results indicate that all peptides examined, except for TGF-beta
suppressed the response to GSM in a manner specific to each peptide. This assay
system would be useful in identification of biologically active peptides.
PMID- 10781025
TI - Selective removal of a target stimulus localized by taste in humans.
AB - Recent studies have shown that people can localize a punctate gustatory stimulus
on the lingual epithelium in the absence of discriminative tactile cues. The
present studies examined the human ability to localize taste sensations on the
tongue and to use this information to remove selectively a target stimulus (a
flavored, 1 cm(3) gelatin cube) from the mouth when presented with non-target
distractors that vary in number and taste. Findings indicate that humans are
capable of localizing and removing either an aversive or an appetitive gustatory
target from a field of tactile distractors via taste sensations alone, although
this ability diminishes as the number of distractors increases (implicating
serial searches, rather than parallel). In addition, humans can localize and
selectively remove a target taste in the presence of distractors of another
distinct taste quality. Under these conditions performance is either unaffected
or reduced, which indicates that contrast with the distinct taste of the
distractors does not enhance performance. Humans also are capable of removing a
nearly tasteless cube from a field of flavored distractors, but this is clearly a
more difficult task, suggesting that 'tactile capture' of taste occurs for the
tasteless target cube and interferes with the localization of taste. Finally,
perceived suprathreshold stimulus intensity did not seem to be related to the
ability to localize and remove a target stimulus via taste sensations and failed
to account for variations in performance across individuals.
PMID- 10781026
TI - Olfactory discrimination ability for aliphatic odorants as a function of oxygen
moiety.
AB - We tested the ability of human subjects to distinguish between aliphatic odorants
sharing the same number of carbon atoms but differing in their functional groups.
1-Alcohols, n-aldehydes, 2-ketones and n-carboxylic acids of four, six and eight
carbon atoms, respectively, were employed. In a forced-choice triangular test
procedure 20 subjects were repeatedly presented with 18 odor pairs and asked to
identify the bottle containing the odd stimulus. We found (i) that as a group,
the subjects performed significantly above chance level in all tasks and thus
were clearly able to discriminate between all odor pairs presented; (ii) marked
interindividual differences in discrimination performance, ranging from subjects
who were able to significantly distinguish between all 18 odor pairs to subjects
who failed to do so with 1/3 of the tasks; (iii) a lack of significant
differences in performance between male and female, and between Japanese and
German subjects; (iv) that odor pairs that involved 2-ketones and/or n-carboxylic
acids were significantly easier to discriminate compared to odor pairs that
involved 1-alcohols and/or n-aldehydes, and thus a clear dependence of
discriminability on type of functional group; and (v) that aliphatic odorants
with eight carbon atoms (irrespective of their oxygen moiety) were significantly
more difficult to discriminate from each other compared to substances with four
or six carbon atoms. The results suggest that functional groups may be an
important determinant of the interaction between stimulus molecule and olfactory
receptor in aliphatic substances, and thus may be a molecular property affecting
odor quality in a substance class-specific manner.
PMID- 10781028
TI - The 33rd annual meeting of the japanese association for the study of taste and
smell (JASTS XXXIII)
PMID- 10781027
TI - Rewiring the olfactory bulb: changes in odor maps following recovery from nerve
transection.
AB - Recent studies have shown that axons from olfactory receptor subtypes converge
onto glomeruli in fixed positions within the olfactory bulb. Different receptor
subtypes project to different glomeruli, forming a spatial distribution of odor
information or 'odor maps'. Olfactory receptor neurons are continuously replaced
throughout the life span of an animal, yet they preserve this highly localized
mapping of receptor subtypes. In this study we used a transgenic mouse (P2-IRES
tau-lacZ) to map axons from a single receptor subtype (P2 receptors) in order to
determine if regenerating axons were able to re-establish the P2 receptor map
following nerve transection. Results confirm that P2 receptor axons retain their
capacity to grow back to the olfactory bulb and converge onto glomeruli following
nerve transection. However, the location and number of convergence sites was
significantly altered compared to the control map. This change in the spatial
distribution of axons alters the topography of odor mapping and has important
implications for the processing of olfactory information. Findings from this
study may explain why animals recovering from nerve injury require odor training
before odor discrimination is restored. Future studies of olfactory receptor
mapping could prove helpful in planning strategies to rewire connections in the
brain and to restore function following injury or neurological disease.
PMID- 10781029
TI - Serine/Threonine kinases 3pK and MAPK-activated protein kinase 2 interact with
the basic helix-loop-helix transcription factor E47 and repress its
transcriptional activity.
AB - In the search for physiological substrates of MAPK-activated protein (MAPKAP)
kinases, we identified the basic helix-loop-helix (bHLH) transcription factor E47
as an interaction partner of chromosome 3p kinase (3pK) and MAPKAP-K2 (MK2). The
E2A protein E47 is known to be involved in the regulation of tissue-specific gene
expression and cell differentiation. E47 is a phosphoprotein, and we identified
3pK and MK2 as E47 kinases in vitro. Furthermore, the expression of either kinase
results in a repression of the transcriptional activity of E47 on an E-box
containing promoter. In summary, the MAPK-activated protein kinases 3pK and MK2
were identified to form an assembly with the bHLH protein E47 suggesting that
these kinases are regulators of E47 activity and E47-dependent gene expression.
PMID- 10781030
TI - Dietary flavonoids and the MLL gene: A pathway to infant leukemia?
PMID- 10781031
TI - Brain growth and the cognitive map.
PMID- 10781032
TI - Absinthe and gamma-aminobutyric acid receptors.
PMID- 10781033
TI - Allosteric activation of the CaR by L-amino acids.
PMID- 10781034
TI - Polyamines in spermiogenesis: not now, darling.
PMID- 10781035
TI - Introduction. The evolution of evo-devo biology.
PMID- 10781036
TI - The Cambrian "explosion": slow-fuse or megatonnage?
AB - Clearly, the fossil record from the Cambrian period is an invaluable tool for
deciphering animal evolution. Less clear, however, is how to integrate the
paleontological information with molecular phylogeny and developmental biology
data. Equally challenging is answering why the Cambrian period provided such a
rich interval for the redeployment of genes that led to more complex body plans.
PMID- 10781038
TI - Evolution of the bilaterian body plan: what have we learned from annelids?
AB - Annelids, unlike their vertebrate or fruit fly cousins, are a bilaterian taxon
often overlooked when addressing the question of body plan evolution. However,
recent data suggest that annelids offer unique insights on the early evolution of
spiral cleavage, anteroposterior axis formation, body axis segmentation, and head
versus trunk distinction.
PMID- 10781037
TI - Regulatory evolution and the origin of the bilaterians.
AB - The adult body plan of bilaterians is achieved by imposing regional
specifications on pluripotential cells. The establishment of spatial domains is
governed in part by regulating expression of transcription factors. The key to
understanding bilaterian evolution is contingent on our understanding of how the
regulation of these transcription factors influenced bilaterian stem-group
evolution.
PMID- 10781040
TI - It's a bug's life.
AB - Although the mechanisms of anterior-posterior axis formation are well understood
in Drosophila, both embryological and molecular studies suggest significant
variation in the mechanisms generating this axis within the Insecta class as a
whole.
PMID- 10781039
TI - Arthropods: developmental diversity within a (super) phylum.
AB - The expression patterns of developmental genes provide new markers that address
the homology of body parts and provide clues as to how body plans have evolved.
Such markers support the idea that insect wings evolved from limbs but refute the
idea that insect and crustacean jaws are fundamentally different in structure.
They also confirm that arthropod tagmosis reflects underlying patterns of Hox
gene regulation but they do not yet resolve to what extent Hox expression domains
may serve to define segment homologies.
PMID- 10781041
TI - Inversion of the chordate body axis: are there alternatives?
AB - One major morphological difference between chordates and annelids or arthropods
is the opposite orientation of the nerve cord and heart. A long-standing proposal
is that the chordate axis evolved by inverting the body of an ancestor with the
annelid/arthropod orientation. However, the data can also be explained by a
common ancestor with diffuse dorsoventral organization, followed by oppositely
directed condensation of the nerve cord and relocation of the heart in the two
lines.
PMID- 10781042
TI - Vertebrate innovations.
AB - Vertebrate innovations include neural crest cells and their derivatives,
neurogenic placodes, an elaborate segmented brain, endoskeleton, and an increase
in the number of genes in the genome. Comparative molecular and developmental
data give new insights into the evolutionary origins of these characteristics and
the complexity of the vertebrate body.
PMID- 10781043
TI - The new animal phylogeny: reliability and implications.
AB - DNA sequence analysis dictates new interpretation of phylogenic trees. Taxa that
were once thought to represent successive grades of complexity at the base of the
metazoan tree are being displaced to much higher positions inside the tree. This
leaves no evolutionary "intermediates" and forces us to rethink the genesis of
bilaterian complexity.
PMID- 10781045
TI - Evolution of biological complexity.
AB - To make a case for or against a trend in the evolution of complexity in
biological evolution, complexity needs to be both rigorously defined and
measurable. A recent information-theoretic (but intuitively evident) definition
identifies genomic complexity with the amount of information a sequence stores
about its environment. We investigate the evolution of genomic complexity in
populations of digital organisms and monitor in detail the evolutionary
transitions that increase complexity. We show that, because natural selection
forces genomes to behave as a natural "Maxwell Demon," within a fixed
environment, genomic complexity is forced to increase.
PMID- 10781044
TI - Precambrian animal diversity: putative phosphatized embryos from the Doushantuo
Formation of China.
AB - Putative fossil embryos and larvae from the Precambrian phosphorite rocks of the
Doushantuo Formation in Southwest China have been examined in thin section by
bright field and polarized light microscopy. Although we cannot completely
exclude a nonbiological or nonmetazoan origin, we identified what appear to be
modern cnidarian developmental stages, including both anthozoan planula larvae
and hydrozoan embryos. Most importantly, the sections contain a variety of small
(=200 microm) structures that greatly resemble gastrula stage embryos of modern
bilaterian forms.
PMID- 10781046
TI - Evolution of the chordate body plan: new insights from phylogenetic analyses of
deuterostome phyla.
AB - The deuterostome phyla include Echinodermata, Hemichordata, and Chordata.
Chordata is composed of three subphyla, Vertebrata, Cephalochordata
(Branchiostoma), and Urochordata (Tunicata). Careful analysis of a new 18S rDNA
data set indicates that deuterostomes are composed of two major clades: chordates
and echinoderms + hemichordates. This analysis strongly supports the monophyly of
each of the four major deuterostome taxa: Vertebrata + Cephalochordata,
Urochordata, Hemichordata, and Echinodermata. Hemichordates include two distinct
classes, the enteropneust worms and the colonial pterobranchs. Most previous
hypotheses of deuterostome origins have assumed that the morphology of extant
colonial pterobranchs resembles the ancestral deuterostome. We present a
molecular phylogenetic analysis of hemichordates that challenges this long-held
view. We used 18S rRNA to infer evolutionary relationships of the hemichordate
classes Pterobranchia and Enteropneusta. Our data show that pterobranchs may be
derived within enteropneust worms rather than being a sister clade to the
enteropneusts. The nesting of the pterobranchs within the enteropneusts
dramatically alters our view of the evolution of the chordate body plan and
suggests that the ancestral deuterostome more closely resembled a mobile worm
like enteropneust than a sessile colonial pterobranch.
PMID- 10781047
TI - Pax gene diversity in the basal cnidarian Acropora millepora (Cnidaria,
Anthozoa): implications for the evolution of the Pax gene family.
AB - Pax genes encode a family of transcription factors, many of which play key roles
in animal embryonic development but whose evolutionary relationships and
ancestral functions are unclear. To address these issues, we are characterizing
the Pax gene complement of the coral Acropora millepora, an anthozoan cnidarian.
As the simplest animals at the tissue level of organization, cnidarians occupy a
key position in animal evolution, and the Anthozoa are the basal class within
this diverse phylum. We have identified four Pax genes in Acropora: two (Pax-Aam
and Pax-Bam) are orthologs of genes identified in other cnidarians; the others
(Pax-Cam and Pax-Dam) are unique to Acropora. Pax-Aam may be orthologous with
Drosophila Pox neuro, and Pax-Bam clearly belongs to the Pax-2/5/8 class. The Pax
Bam Paired domain binds specifically and preferentially to Pax-2/5/8 binding
sites. The recently identified Acropora gene Pax-Dam belongs to the Pax-3/7
class. Clearly, substantial diversification of the Pax family occurred before the
Cnidaria/higher Metazoa split. The fourth Acropora Pax gene, Pax-Cam, may
correspond to the ancestral vertebrate Pax gene and most closely resembles Pax-6.
The expression pattern of Pax-Cam, in putative neurons, is consistent with an
ancestral role of the Pax family in neural differentiation and patterning. We
have determined the genomic structure of each Acropora Pax gene and show that
some splice sites are shared both between the coral genes and between these and
Pax genes in triploblastic metazoans. Together, these data support the monophyly
of the Pax family and indicate ancient origins of several introns.
PMID- 10781048
TI - Analysis of a complete homeobox gene repertoire: implications for the evolution
of diversity.
AB - The completion of sequencing projects for various organisms has already advanced
our insight into the evolution of entire genomes and the role of gene
duplications. One multigene family that has served as a paradigm for the study of
gene duplications and molecular evolution is the family of homeodomain-encoding
genes. I present here an analysis of the homeodomain repertoire of an entire
genome, that of the nematode Caenorhabditis elegans, in relation to our current
knowledge of these genes in plants, arthropods, and mammals. A methodological
framework is developed that proposes approaches for the analysis of homeodomain
repertoires and multigene families in general.
PMID- 10781049
TI - Quantitative assessment of Hox complex expression in the indirect development of
the polychaete annelid Chaetopterus sp.
AB - A prediction from the set-aside theory of bilaterian origins is that pattern
formation processes such as those controlled by the Hox cluster genes are
required specifically for adult body plan formation. This prediction can be
tested in animals that use maximal indirect development, in which the embryonic
formation of the larva and the postembryonic formation of the adult body plan are
temporally and spatially distinct. To this end, we quantitatively measured the
amount of transcripts for five Hox genes in embryos of a lophotrochozoan, the
polychaete annelid Chaetopterus sp. The polychaete Hox complex is shown not to be
expressed during embryogenesis, but transcripts of all measured Hox complex genes
are detected at significant levels during the initial stages of adult body plan
formation. Temporal colinearity in the sequence of their activation is observed,
so that activation follows the 3'-5' arrangement of the genes. Moreover, Hox gene
expression is spatially localized to the region of teloblastic set-aside cells of
the later-stage embryos. This study shows that an indirectly developing
lophotrochozoan shares with an indirectly developing deuterostome, the sea
urchin, a common mode of Hox complex utilization: construction of the larva,
whether a trochophore or dipleurula, does not involve Hox cluster expression, but
in both forms the complex is expressed in the set-aside cells from which the
adult body plan derives.
PMID- 10781050
TI - Evolution of Antp-class genes and differential expression of Hydra Hox/paraHox
genes in anterior patterning.
AB - The conservation of developmental functions exerted by Antp-class homeoproteins
in protostomes and deuterostomes suggested that homologs with related functions
are present in diploblastic animals. Our phylogenetic analyses showed that Antp
class homeodomains belong either to non-Hox or to Hox/paraHox families. Among the
13 non-Hox families, 9 have diploblastic homologs, Msx, Emx, Barx, Evx, Tlx, NK
2, and Prh/Hex, Not, and Dlx, reported here. Among the Hox/paraHox, poriferan
sequences were not found, and the cnidarian sequences formed at least five
distinct cnox families. Two are significantly related to the paraHox Gsx (cnox-2)
and the mox (cnox-5) sequences, whereas three display some relatedness to the Hox
paralog groups 1 (cnox-1), 9/10 (cnox-3) and the paraHox cdx (cnox-4).
Intermediate Hox/paraHox genes (PG 3 to 8 and lox) did not have clear cnidarian
counterparts. In Hydra, cnox-1, cnox-2, and cnox-3 were not found chromosomally
linked within a 150-kb range and displayed specific expression patterns in the
adult head. During regeneration, cnox-1 was expressed as an early gene whatever
the polarity, whereas cnox-2 was up-regulated later during head but not foot
regeneration. Finally, cnox-3 expression was reestablished in the adult head once
it was fully formed. These results suggest that the Hydra genes related to
anterior Hox/paraHox genes are involved at different stages of apical
differentiation. However, the positional information defining the oral/aboral
axis in Hydra cannot be correlated strictly to that characterizing the anterior
posterior axis in vertebrates or arthropods.
PMID- 10781051
TI - Caenorhabditis elegans embryonic axial patterning requires two recently
discovered posterior-group Hox genes.
AB - Hox genes encode highly conserved transcription factors that control regional
identities of cells and tissues along the developing anterior-posterior axis,
probably in all bilaterian metazoans. However, in invertebrate embryos other than
Drosophila, Hox gene functions remain largely unknown except by inference from
sequence similarities and expression patterns. Recent genomic sequencing has
shown that Caenorhabditis elegans has three Hox genes of the posterior paralog
group [Ruvkun, G. & Hobert, O. (1998) Science 282, 2033-2041]. However, only one
has been previously identified genetically, and it is not required for embryonic
development [Chisholm, A. (1991) Development (Cambridge, U.K.) 111, 921-932].
Herein, we report identification of the remaining two posterior paralogs as the
nob-1 gene and the neighboring php-3 gene. Elimination of nob-1 and php-3
functions causes gross embryonic defects in both posterior patterning and
morphogenetic movements of the posterior hypodermis, as well as posterior-to
anterior cell fate transformations and lethality. The only other Hox gene
essential for embryogenesis is the labial/Hox1 homolog ceh-13, required for more
anterior patterning [Brunschwig, K., Wittmann, C., Schnabel, R., Burglin, T. R.,
Tobler, H. & Muller, F. (1999) Development (Cambridge, U.K.) 126, 1537-1546].
Therefore, essential embryonic patterning in C. elegans requires only Hox genes
of the anterior and posterior paralog groups, raising interesting questions about
evolution of the medial-group genes.
PMID- 10781052
TI - Distinct roles of the homeotic genes Ubx and abd-A in beetle embryonic abdominal
appendage development.
AB - Insects are easily distinguishable by the absence of legs on the adult abdomen.
Studies performed on the Dipteran, Drosophila melanogaster, indicate that this is
because of the repressive effects of the homeotic genes Ultrabithorax (Ubx) and
abdominal-A (abd-A) on the limb promoting gene Distal-less (Dll) during embryonic
development. However, in many species appendage-like structures are present on
abdominal segments in embryonic and juvenile stages. Here, by using classical
genetics and double-stranded RNA-mediated gene silencing in the red flour beetle,
Tribolium castaneum, a species that develops an appendage on the first abdominal
segment, we investigate the roles of Ubx and Abd-A in abdominal limb development.
We find that in Tribolium, Abd-A, but not Ubx, represses early expression of Dll
in the embryonic abdomen. Ubx appears to modify the A1 appendage. This difference
in the activities of Abd-A and Ubx is critical for proper development of this
appendage. We suggest that an ancestral role of Abd-A in insect abdominal
appendage development was in the repression of Dll initiation and that of Ubx was
in modulation of abdominal appendage morphology.
PMID- 10781053
TI - Implications of the Tribolium Deformed mutant phenotype for the evolution of Hox
gene function.
AB - Among insects, the genetic regulation of regional identities in the postoral head
or gnathal segments (mandibular, maxillary, and labial) is best understood in the
fly Drosophila melanogaster. In part, normal gnathal development depends on
Deformed (Dfd) and Sex combs reduced (Scr), genes in the split Drosophila
homeotic complex. The gnathal segments of Dfd and Scr mutant larvae are abnormal
but not homeotically transformed. In the red flour beetle, Tribolium castaneum,
we have isolated loss-of-function mutations of the Deformed ortholog. Mutant
larvae display a strong transformation of mandibular appendages to antennae. The
maxillary appendages, normally composed of an endite and a telopodite, develop
only the telopodite in mutant larvae. We previously reported that mutations in
the beetle Scr and Antennapedia orthologs cause the labial and thoracic
appendages, respectively, to be transformed to antennae. Moreover, a deficiency
of most of the beetle homeotic complex causes all gnathal (as well as thoracic
and abdominal) segments to develop antennae. These and other observations are
consistent with the hypothesis that ancestral insect homeotic gene functions have
been modified considerably during the evolution of the highly specialized maggot
head. One of the ancestral homeobox genes that arose close to the root of the
Eumetazoa appears to have given rise to Dfd, Scr, and the Antennapedia homeobox
class homeotic genes. Evidence from both Tribolium and Drosophila suggests that
this ancestral gene served to repress anterior development as well as confer a
trunk-specific identity.
PMID- 10781054
TI - Expression patterns of hairy, even-skipped, and runt in the spider Cupiennius
salei imply that these genes were segmentation genes in a basal arthropod.
AB - There is an ongoing discussion on whether segmentation in different phyla has a
common origin sharing a common genetic program. However, before comparing
segmentation between phyla, it is necessary to identify the ancestral condition
within each phylum. Even within the arthropods it is not clear which parts of the
genetic network leading to segmentation are conserved in all groups. In this
paper, we analyze the expression of three segmentation genes of the pair-rule
class in the spider Cupiennius salei. Spiders are representatives of the
Chelicerata, a monophyletic basic arthropod group. We find that in spider
embryos, the orthologues for the Drosophila primary pair-rule genes hairy, even
skipped, and runt are expressed in stripes in the growth zone, where the segments
are forming, suggesting a role for these genes in chelicerate segmentation. These
data imply that the involvement of hairy, even-skipped, and runt in arthropod
segmentation is an ancestral character for arthropods and is not restricted to a
particular group of insects.
PMID- 10781055
TI - Wnt/Shh interactions regulate ectodermal boundary formation during mammalian
tooth development.
AB - Interactions between the Wnt (wingless) and hedgehog signaling pathways were
first described as playing a role in establishing boundaries between ectodermal
cells in Drosophila segmentation. During the initiation of mammalian tooth
development, boundaries that distinguish oral from dental ectoderm must be formed
to correctly position the sites of tooth formation. We describe a reciprocal
relationship between the expression of Wnt-7b in presumptive oral ectoderm and
Shh in presumptive dental ectoderm in mouse embryos that mark boundaries between
these cells with different developmental fates. By using a murine retrovirus to
ectopically express Wnt-7b in presumptive dental ectoderm in mandibular arch
explants, we show that Shh expression in the ectoderm and Ptc expression in the
underlying ectomesenchyme are down-regulated, and tooth development is
subsequently arrested. This suggests that Wnt-7b acts to repress Shh expression
in oral ectoderm, thus maintaining the boundaries between oral and dental
ectodermal cells. Implantation of beads soaked in Shh protein into Wnt-7b
infected explants resulted in complete rescue of tooth development, confirming
that the repressive action of Wnt-7b specifically affects Shh signaling.
PMID- 10781056
TI - Searching for the prototypic eye genetic network: Sine oculis is essential for
eye regeneration in planarians.
AB - We have identified a sine oculis gene in the planarian Girardia tigrina
(Platyhelminthes; Turbellaria; Tricladida). The planarian sine oculis gene (Gtso)
encodes a protein with a sine oculis (Six) domain and a homeodomain that shares
significant sequence similarity with so proteins assigned to the Six-2 gene
family. Gtso is expressed as a single transcript in both regenerating and fully
developed eyes. Whole-mount in situ hybridization studies show exclusive
expression in photoreceptor cells. Loss of function of Gtso by RNA interference
during planarian regeneration inhibits eye regeneration completely. Gtso is also
essential for maintenance of the differentiated state of photoreceptor cells.
These results, combined with the previously demonstrated expression of Pax-6 in
planarian eyes, suggest that the same basic gene regulatory circuit required for
eye development in Drosophila and mouse is used in the prototypic eye spots of
platyhelminthes and, therefore, is truly conserved during evolution.
PMID- 10781057
TI - Divergence of larval morphology between Drosophila sechellia and its sibling
species caused by cis-regulatory evolution of ovo/shaven-baby.
AB - We report an extreme morphological difference between Drosophila sechellia and
related species of the pattern of hairs on first-instar larvae. On the dorsum of
most species, the posterior region of the anterior compartment of most segments
is covered by a carpet of fine hairs. In D. sechellia, these hairs have been lost
and replaced with naked cuticle. Genetic mapping experiments and interspecific
complementation tests indicate that this difference is caused, in its entirety,
by evolution at the ovo/shaven-baby locus. The pattern of expression of the
ovo/shaven-baby transcript is correlated with this morphological change. The
altered dorsal cuticle pattern is probably caused by evolution of the cis
regulatory region of ovo/shaven-baby in the D. sechellia lineage.
PMID- 10781058
TI - The origin of plants: body plan changes contributing to a major evolutionary
radiation.
PMID- 10781059
TI - PMD fundamentals: polarization mode dispersion in optical fibers.
AB - This paper reviews the fundamental concepts and basic theory of polarization mode
dispersion (PMD) in optical fibers. It introduces a unified notation and
methodology to link the various views and concepts in Jones space and Stokes
space. The discussion includes the relation between Jones vectors and Stokes
vectors, rotation matrices, the definition and representation of PMD vectors, the
laws of infinitesimal rotation, and the rules for PMD vector concatenation.
PMID- 10781060
TI - Geoelectric potential changes: possible precursors to earthquakes in Japan.
AB - Whether electromagnetic precursors to earthquakes (EQs) exist is an important
question not only for EQ prediction but also for understanding the physical
processes of EQ generation. Slow transient geoelectric potential changes have
been observed before several recent EQs in Japan. In most cases, they appeared 1
19 days before the EQs, and their duration and intensity were several minutes to
1 h and 1-2 mV/100 m. The changes appeared before five of all six EQs with
magnitude >/= 5 that occurred within 20 km of our stations during the observation
period. Changes were also detected at greater epicentral distances (up to 75 km)
before two other EQs, including one EQ of magnitude 4.7, which was preceded by a
signal simultaneously recorded at three widely separated stations. These
geoelectric potential changes have been distinguished through the following
criteria from a multitude of other changes, which were noise of various origins.
(i) The selected changes were proportional in amplitude to the length of the
recording station's short ( approximately 100 m) dipoles and were simultaneously
detected also on long (1-10 km) dipoles when the latter were in operation. (ii)
No such changes occurred during the observation period that were not followed by
EQs. Although the EQ precursory nature of these geoelectric potential changes is
admittedly unproven, it seems that the present results warrant continued serious
research into the occurrence, generation, and transmission of these signals and
their possible causal relationship to EQs.
PMID- 10781061
TI - Uncovering the [2Fe2S] domain movement in cytochrome bc1 and its implications for
energy conversion.
AB - In crystals of the key respiratory and photosynthetic electron transfer protein
called ubihydroquinone:cytochrome (cyt) c oxidoreductase or cyt bc(1), the
extrinsic [2Fe2S] cluster domain of its Fe-S subunit assumes several
conformations, suggesting that it may move during catalysis. Herein, using
Rhodobacter capsulatus mutants that have modifications in the hinge region of
this subunit, we were able to reveal this motion kinetically. Thus, the bc(1)
complex (and possibly the homologous b(6)f complex in chloroplasts) employs the
[2Fe2S] cluster domain as a device to shuttle electrons from ubihydroquinone to
cyt c(1) (or cyt f). We demonstrate that this domain movement is essential for
cyt bc(1) function, because a mutant enzyme with a nonmoving Fe-S subunit has no
catalytic activity, and one with a slower movement has lower activity. This
motion is apparently designed with a natural frequency slow enough to assure
productive Q(o) site charge separation but fast enough not to be rate limiting.
These findings add the unprecedented function of intracomplex electron shuttling
to large-scale domain motions in proteins and may well provide a target for cyt
bc(1) antibiotics.
PMID- 10781062
TI - The crystal structure of palmitoyl protein thioesterase 1 and the molecular basis
of infantile neuronal ceroid lipofuscinosis.
AB - Mutations in palmitoyl-protein thioesterase 1 (PPT1), a lysosomal enzyme that
removes fatty acyl groups from cysteine residues in modified proteins, cause the
fatal inherited neurodegenerative disorder infantile neuronal ceroid
lipofuscinosis. The accumulation of undigested substrates leads to the formation
of neuronal storage bodies that are associated with the clinical symptoms. Less
severe forms of PPT1 deficiency have been found recently that are caused by a
distinct set of PPT1 mutations, some of which retain a small amount of
thioesterase activity. We have determined the crystal structure of PPT1 with and
without bound palmitate by using multiwavelength anomalous diffraction phasing.
The structure reveals an alpha/beta-hydrolase fold with a catalytic triad
composed of Ser115-His289-Asp233 and provides insights into the structural basis
for the phenotypes associated with PPT1 mutations.
PMID- 10781063
TI - A Nedd8 conjugation pathway is essential for proteolytic targeting of p27Kip1 by
ubiquitination.
AB - Temporal control of p27(Kip1) (p27) degradation imposes periodicity in its
activity during cell cycle progression and its accumulation during cell cycle
exit. Degradation of p27 is initiated by phosphorylation of p27 at Thr-187, which
marks the protein for ubiquitination by SCF(Skp2) and subsequent proteolysis by
the 26S proteasome. Here we show that the p27 ubiquitination activity in cell
extracts depends on the presence of the ubiquitin-like protein Nedd8 and enzymes
that catalyze Nedd8 conjugation to proteins. Moreover, we show that
reconstitution of the p27 ubiquitination activity of recombinant SCF(Skp2) also
requires Nedd8 conjugation pathway components. Inactivation of the Nedd8
conjugation pathway by a dominant negative mutant of the Nedd8-conjugating enzyme
Nce1/Ubc12 blocks the ubiquitination and degradation of p27 in cell extracts.
Consistent with a role in cell-cycle progression, Nedd8 is expressed in
proliferating cells and is itself down-regulated upon cellular differentiation.
These results suggest that the Nedd8 conjugation pathway may regulate the
turnover of p27(Kip1), independently of p27 phosphorylation, and further
establishes the identity of protein components involved in p27 ubiquitination.
Finally, these findings provide a direct demonstration of a function for Nedd8 in
a biological process.
PMID- 10781064
TI - The in vitro and in vivo phosphotyrosine map of activated MuSK.
AB - The muscle-specific receptor tyrosine kinase MuSK plays a crucial role in
neuromuscular synapse formation. Activation of MuSK is induced by agrin leading
to clustering of several proteins, including acetylcholine receptors, at synaptic
sites. In a first step to elucidate the signal transduction cascade following
MuSK activation and leading to clustering of synaptic proteins, we sought to
identify the tyrosine residues that are phosphorylated in activated MuSK. We
mapped the tyrosine residues that are phosphorylated in vitro and in vivo using
methods that provide high sensitivity and do not require radioactive tracers. We
expressed MuSK in insect cells by using a baculovirus expression vector and
mapped the tyrosines that are phosphorylated in MuSK in an in vitro kinase assay
using matrix-assisted laser desorption ionization MS to sequence tryptic peptides
fractionated by HPLC. In addition, we isolated MuSK from Torpedo electric organ
and used nanoelectrospray tandem mass spectrometry and parent ion scanning to
identify the tyrosine residues that are phosphorylated in activated, endogenous
MuSK in vivo. We found that six of the nineteen intracellular tyrosine residues
in MuSK are phosphorylated in activated MuSK: the juxtamembrane tyrosine (Y553),
the tyrosines within the activation loop (Y750, Y754, and Y755), a tyrosine near
the beginning of the kinase domain (Y576), and a tyrosine (Y812) within the C
terminal lobe of the kinase domain. Our biochemical data are consistent with
results from functional experiments and establish a good correlation between
tyrosine residues that are phosphorylated in activated MuSK and tyrosines that
are required for MuSK signaling.
PMID- 10781065
TI - Selecting rRNA binding sites for the ribosomal proteins L4 and L6 from randomly
fragmented rRNA: application of a method called SERF.
AB - Two-thirds of the 54 proteins of the Escherichia coli ribosome interact directly
with the rRNAs, but the rRNA binding sites of only a very few proteins are known.
We present a method (selection of random RNA fragments; SERF) that can identify
the minimal binding region for proteins within ribonucleo-protein complexes such
as the ribosome. The power of the method is exemplified with the ribosomal
proteins L4 and L6. Binding sequences are identified for both proteins and
characterized by phosphorothioate footprinting. Surprisingly, the binding region
of L4, a 53-nt rRNA fragment of domain I of 23S rRNA, can simultaneously and
independently bind L24, one of the two assembly initiator proteins of the large
subunit.
PMID- 10781067
TI - Association of Escherichia coli ribosomes with the inner membrane requires the
signal recognition particle receptor but is independent of the signal recognition
particle.
AB - In mammalian cells, as well as Escherichia coli, ribosomes translating membrane
proteins interact cotranslationally with translocons in the membrane, and this
interaction is essential for proper insertion of nascent polypeptides into the
membrane. Both the signal recognition particle (SRP) and its receptor (SR) are
required for functional association of ribosomes translating integral membrane
proteins with the translocon. Herein, we confirm that membrane targeting of E.
coli ribosomes requires the prokaryotic SRalpha homolog FtsY in vivo.
Surprisingly, however, depletion of the E. coli SRP54 homolog (Ffh) has no
significant effect on binding of ribosomes to the membrane, although Ffh
depletion is detrimental to growth. These and other observations suggest that, in
E. coli, SRP may operate downstream of SR-mediated targeting of ribosomes to the
plasma membrane.
PMID- 10781066
TI - Functional interaction between the Werner Syndrome protein and DNA polymerase
delta.
AB - Werner Syndrome (WS) is an inherited disease characterized by premature onset of
aging, increased cancer incidence, and genomic instability. The WS gene encodes a
1,432-amino acid polypeptide (WRN) with a central domain homologous to the RecQ
family of DNA helicases. Purified WRN unwinds DNA with 3'-->5' polarity, and also
possesses 3'-->5' exonuclease activity. Elucidation of the physiologic
function(s) of WRN may be aided by the identification of WRN-interacting
proteins. We show here that WRN functionally interacts with DNA polymerase delta
(pol delta), a eukaryotic polymerase required for DNA replication and DNA repair.
WRN increases the rate of nucleotide incorporation by pol delta in the absence of
proliferating cell nuclear antigen (PCNA) but does not stimulate the activity of
eukaryotic DNA polymerases alpha or epsilon, or a variety of other DNA
polymerases. Moreover, we show that functional interaction with WRN is mediated
through the third subunit of pol delta: i.e., Pol32p of Saccharomyces cerevisae,
corresponding to the recently identified p66 subunit of human pol delta. Absence
of the third subunit abrogates stimulation by WRN, and stimulation is restored by
reconstituting the three-subunit enzyme. Our findings suggest that WRN may
facilitate pol delta-mediated DNA replication and/or DNA repair and that
disruption of WRN-pol delta interaction in WS cells may contribute to the
previously observed S-phase defects and/or the unusual sensitivity to a limited
number of DNA damaging agents.
PMID- 10781068
TI - A biological function for cadmium in marine diatoms.
AB - The oceanic distribution of cadmium follows closely that of major algal nutrients
such as phosphate. The reasons for this "nutrient-like" distribution are unclear,
however, because cadmium is not generally believed to have a biological function.
Herein, we provide evidence of a biological role for Cd in the marine diatom
Thalassiosira weissflogii under conditions of low zinc, typical of the marine
environment. Addition of Cd to Zn-limited cultures enhances the growth rate of T.
weissflogii, particularly at low pCO(2). This increase in growth rate is
reflected in increased levels of cellular carbonic anhydrase (CA) activity,
although the levels of TWCA1, the major intracellular Zn-requiring isoform of CA
in T. weissflogii, remain low. (109)Cd label comigrates with a protein band that
shows CA activity and is distinct from TWCA1 on native PAGE of radiolabeled T.
weissflogii cell lysates. The levels of the Cd protein are modulated by CO(2) in
a manner that is consistent with a role for this enzyme in carbon acquisition.
Purification of the CA-active fraction leads to the isolation of a Cd-containing
protein of 43 kDa. It is now clear that T. weissflogii expresses a Cd-specific
CA, which, particularly under conditions of Zn limitation, can replace the Zn
enzyme TWCA1 in its carbon-concentrating mechanism.
PMID- 10781069
TI - Single-electron reduction of the oxidized state is coupled to proton uptake via
the K pathway in Paracoccus denitrificans cytochrome c oxidase.
AB - The reductive part of the catalytic cycle of cytochrome c oxidase from Paracoccus
denitrificans was examined by using time-resolved potential measurements on black
lipid membranes. Proteoliposomes were adsorbed to the black lipid membranes and
Ru(II)(2, 2'-bipyridyl)(3)(2+) was used as photoreductant to measure flash
induced membrane potential generation. Single-electron reduction of the oxidized
wild-type cytochrome c oxidase reveals two phases of membrane potential
generation (tau(1) approximately 20 micros and tau(2) approximately 175 micros)
at pH 7.4. The fast phase is not sensitive to cyanide and is assigned to electron
transfer from Cu(A) to heme a. The slower phase is inhibited completely by
cyanide and shows a kinetic deuterium isotope effect by a factor of 2-3. Although
two enzyme variants mutated in the so-called D pathway of proton transfer (D124N
and E278Q) show the same time constants and relative amplitudes as the wild-type
enzyme, in the K pathway variant K354M, tau(2) is increased to 900 micros. This
result suggests uptake of a proton through the K pathway during the transition
from the oxidized to the one-electron reduced state. After the second laser flash
under anaerobic conditions, a third electrogenic phase with a time constant of
approximately 1 ms appears. The amplitude of this phase grows with increasing
flash number. We explain this growth by injection of a second electron into the
single-electron reduced enzyme. On multiple flashes, both D pathway mutants
behave differently compared with the wild type and two additional slow phases of
tau(3) approximately 2 ms and tau(4) approximately 15 ms are observed. These
results suggest that the D pathway is involved in proton transfer coupled to the
uptake of the second electron.
PMID- 10781070
TI - Robust perfect adaptation in bacterial chemotaxis through integral feedback
control.
AB - Integral feedback control is a basic engineering strategy for ensuring that the
output of a system robustly tracks its desired value independent of noise or
variations in system parameters. In biological systems, it is common for the
response to an extracellular stimulus to return to its prestimulus value even in
the continued presence of the signal-a process termed adaptation or
desensitization. Barkai, Alon, Surette, and Leibler have provided both
theoretical and experimental evidence that the precision of adaptation in
bacterial chemotaxis is robust to dramatic changes in the levels and kinetic rate
constants of the constituent proteins in this signaling network [Alon, U.,
Surette, M. G., Barkai, N. & Leibler, S. (1998) Nature (London) 397, 168-171].
Here we propose that the robustness of perfect adaptation is the result of this
system possessing the property of integral feedback control. Using techniques
from control and dynamical systems theory, we demonstrate that integral control
is structurally inherent in the Barkai-Leibler model and identify and
characterize the key assumptions of the model. Most importantly, we argue that
integral control in some form is necessary for a robust implementation of perfect
adaptation. More generally, integral control may underlie the robustness of many
homeostatic mechanisms.
PMID- 10781071
TI - mRNA splicing-mediated C-terminal replacement of transcription factor Hac1p is
required for efficient activation of the unfolded protein response.
AB - Eukaryotic cells control the levels of molecular chaperones and folding enzymes
in the endoplasmic reticulum (ER) by a transcriptional induction process termed
the unfolded protein response (UPR) according to the needs within the ER. In
Saccharomyces cerevisiae, expression of the UPR-specific transcription factor
Hac1p is tightly regulated at the level of mRNA splicing that depends on an
unconventional system. Thus, HAC1 precursor mRNA is constitutively expressed but
not translated. A sensor molecule Ire1p/Ern1p-mediated signaling from the ER
specifically removes an intron of 252 nucleotides from the precursor mRNA, and
the resulting mature mRNA is translated to produce Hac1p. Because the 5' splice
site is located near the C-terminal end of the Hac1p-coding region, this splicing
replaces the last 10 codons of the ORF with an exon encoding 18 aa without
affecting the N-terminal 220-aa region which contains the DNA-binding domain.
Here, we found that this C-terminal 18-aa segment functions as a potent
activation domain. Therefore, the splicing event joins the HAC1 DNA-binding
domain to its activation domain, allowing rapid posttranscriptional generation of
a potent transcriptional activator (238-aa Hac1p) that activates the UPR
efficiently. This suggests that the UPR is hardly activated by Hac1p produced
without splicing (230-aa Hac1p) which may occur in the absence of Ire1p/Ern1p
mediated signaling from the ER. Based on these and other results, we propose that
the control of expression and activity of Hac1p meets the requirements of the ER.
PMID- 10781072
TI - Outer mitochondrial membrane permeability can regulate coupled respiration and
cell survival.
AB - Coupled cellular respiration requires that ATP and ADP be efficiently exchanged
between the cytosol and the mitochondrial matrix. When growth factors are
withdrawn from dependent cells, metabolism is disrupted by a defect in ATP/ADP
exchange across the mitochondrial membranes. Unexpectedly, we find that this
defect results from loss of outer mitochondrial membrane permeability to
metabolic anions. This decrease in anion permeability correlates with the changes
in conductance properties that accompany closure of the voltage-dependent anion
channel (also known as mitochondrial porin). Loss of outer membrane permeability
(i) results in the accumulation of stored metabolic energy within the
intermembrane space in the form of creatine phosphate, (ii) is prevented by the
outer mitochondrial membrane proteins Bcl-x(L) and Bcl-2, and (iii) can be
reversed by growth factor readdition. If outer membrane impermeability persists,
the disruption of mitochondrial homeostasis culminates in loss of outer
mitochondrial membrane integrity, cytochrome c redistribution, and apoptosis. The
recognition that outer membrane permeability is regulated under physiological
conditions has important implications for the understanding of bioenergetics and
cell survival.
PMID- 10781073
TI - The human papillomavirus type 16 negative regulatory RNA element interacts with
three proteins that act at different posttranscriptional levels.
AB - In human papillomaviruses, expression of the late genes L1 and L2, encoding the
capsid proteins, is restricted to the upper layers of the infected epithelium. A
79-nt GU-rich negative regulatory element (NRE) located at the 3' untranslated
region of the human papillomavirus 16 L1 gene was identified previously as key to
the posttranscriptional control of late gene expression. Here, we demonstrate
that in epithelial cells, the NRE can directly bind the U2 auxiliary splicing
factor 65-kDa subunit, the cleavage stimulation factor 64-kDa subunit, and the
Elav-like HuR protein. On induction of epithelial cell differentiation, levels of
the U2 auxiliary splicing factor 65-kDa subunit decrease, levels of the cleavage
stimulation factor 64-kDa subunit increase, and the levels of HuR remain
unchanged, although redistribution of the HuR from the nucleus to the cytoplasm
is observed. Late gene transcripts, which appear to be fully processed, are
detected in undifferentiated W12 cells, but are confined in the nucleus. We
propose that repression of late gene expression in basal epithelial cells may be
caused by nuclear retention or cytoplasmic instability of NRE-containing late
gene transcripts.
PMID- 10781074
TI - Abnormal spermatogenesis and reduced fertility in transition nuclear protein 1
deficient mice.
AB - Transition nuclear proteins (TPs), the major proteins found in chromatin of
condensing spermatids, are believed to be important for histone displacement and
chromatin condensation during mammalian spermatogenesis. We generated mice
lacking the major TP, TP1, by targeted deletion of the Tnp1 gene in mouse
embryonic stem cells. Surprisingly, testis weights and sperm production were
normal in the mutant mice, and only subtle abnormalities were observed in sperm
morphology. Electron microscopy revealed large rod-like structures in the
chromatin of mutant step 13 spermatids, in contrast to the fine chromatin fibrils
observed in wild type. Steps 12-13 spermatid nuclei from the testis of Tnp1-null
mice contained, in place of TP1, elevated levels of TP2 and some protamine 2 (P2)
precursor. Most of the precursor was processed to mature P2, but high levels of
incompletely processed forms remained in epididymal spermatozoa. Sperm motility
was reduced severely, and approximately 60% of Tnp1-null males were infertile. We
concluded that TP1 is not essential for histone displacement or chromatin
condensation. The absence of TP1 may partially be compensated for by TP2 and P2
precursor, but this dysregulation of nucleoprotein replacement results in an
abnormal pattern of chromatin condensation and in reduced fertility.
PMID- 10781076
TI - Primitive synteny of vertebrate major histocompatibility complex class I and
class II genes.
AB - Major histocompatibility complex (MHC) class I and class II molecules bind to and
display peptidic antigens acquired from pathogens that are recognized by
lymphocytes coordinating and executing adaptive immune responses. The two classes
of MHC proteins have nearly identical tertiary structures and were derived from a
common ancestor that probably existed not long before the emergence of the
cartilaginous fish. Class I and class II genes are genetically linked in
tetrapods but are not syntenic in teleost fish, a phylogenetic taxon derived from
the oldest vertebrate ancestor examined to date. Cartilaginous fish (sharks,
skates, and rays) are in the oldest taxon of extant jawed vertebrates; we have
carried out segregation analyses in two families of nurse sharks and one family
of the banded houndshark that revealed a close linkage of class IIalpha and beta
genes both with each other and with the classical class I (class Ia) gene. These
results strongly suggest that the primordial duplication giving rise to classical
class I and class II occurred in cis, and the close linkage between these two
classes of genes has been maintained for at least 460 million years in
representatives of most vertebrate taxa.
PMID- 10781077
TI - A recombination hotspot delimits a wild-species quantitative trait locus for
tomato sugar content to 484 bp within an invertase gene.
AB - In nature, genetic variation usually takes the form of a continuous phenotypic
range rather than discrete classes. The genetic variation underlying quantitative
traits results from the segregation of numerous interacting quantitative trait
loci (QTLs), whose expression is modified by the environment. To uncover the
molecular basis of this variation, we characterized a QTL (Brix9-2-5) derived
from the green-fruited tomato species Lycopersicon pennellii. The wild-species
allele increased glucose and fructose contents in cultivated tomato fruits in
various genetic backgrounds and environments. Using nearly isogenic lines for the
QTL, high-resolution mapping analysis delimited Brix9-2-5 to a single nucleotide
polymorphism-defined recombination hotspot of 484 bp spanning an exon and intron
of a fruit-specific apoplastic invertase. We suggest that the differences between
the Brix9-2-5 alleles of the two species are associated with a polymorphic
intronic element that modulates sink strength of tomato fruits. Our results
demonstrate a link between naturally occurring DNA variation and a Mendelian
determinant of a complex phenotype for a yield-associated trait.
PMID- 10781075
TI - Progesterone-regulated genes in the ovulation process: ADAMTS-1 and cathepsin L
proteases.
AB - Ovulation is a precisely timed process by which a mature oocyte is released from
an ovarian follicle. This process is initiated by the pituitary surge of
luteinizing hormone (LH), is temporally associated with transcriptional
regulation of numerous genes, and is presumed to involve the synthesis and/or
activation of specific proteases that degrade the follicle wall. The progesterone
receptor (PR), a nuclear receptor transcription factor, is induced in granulosa
cells of preovulatory follicles in response to the LH surge and has been shown to
be essential for ovulation, because mice lacking PR fail to ovulate and are
infertile. Using these mice as a model in which to elucidate PR-regulated genes
in the ovulation process, we show that the matrix metalloproteinases MMP-2 and
MMP-9 are not targets of PR during ovulation. In contrast, two other proteases,
ADAMTS-1 (A disintegrin and metalloproteinase with thrombospondin-like motifs)
and cathepsin L (a lysosomal cysteine protease), are transcriptional targets of
PR action. ADAMTS-1 is induced after LH stimulation in granulosa cells of
preovulatory follicles and depends on PR. Cathepsin L is induced in granulosa
cells of growing follicles by follicle-stimulating hormone, but the highest
levels of cathepsin L mRNA occur in preovulatory follicles in response to LH in a
PR-dependent manner. The identification of two regulated proteases in the ovary,
together with their abnormal expression in anovulatory PR knockout mice, suggests
that each plays a critical role in follicular rupture and represents a major
advance in our understanding of the proteolytic events that control ovulation.
PMID- 10781078
TI - A mutant hunt for defects in membrane protein assembly yields mutations affecting
the bacterial signal recognition particle and Sec machinery.
AB - We describe an Escherichia coli genetic screen that yields mutations affecting
two different cellular processes: disulfide bond formation and membrane protein
assembly. The mutants defective in disulfide bond formation include additional
classes of dsbA and dsbB mutations. The membrane protein assembly defective
mutants contain a mutation in the secA operon and three mutations in the ffs
gene, which encodes 4.5S RNA. These latter mutations are the only ones to be
isolated in a gene encoding a component of the bacterial signal recognition
particle by screening in vivo for defects in membrane protein insertion. A
sensitive method for examining membrane protein localization shows that the ffs
and secA locus mutations affect membrane assembly of the polytopic membrane
protein, MalF. The ffs mutations also affect the membrane insertion of the FtsQ
and the AcrB proteins. Although both the ffs and the secA locus mutations
interfere with membrane protein assembly, only the latter also reduces export of
a protein containing a cleavable signal sequence.
PMID- 10781079
TI - Prolyl 4-hydroxylase is required for viability and morphogenesis in
Caenorhabditis elegans.
AB - The genome of Caenorhabditis elegans possesses two genes, dpy-18 and phy-2, that
encode alpha subunits of the enzyme prolyl 4-hydroxylase. We have generated
deletions within each gene to eliminate prolyl 4-hydroxylase activity from the
animal. The dpy-18 mutant has an aberrant body morphology, consistent with a role
of prolyl 4-hydroxylase in formation of the body cuticle. The phy-2 mutant is
phenotypically wild type. However, the dpy-18; phy-2 double mutant is not viable,
suggesting an essential role for prolyl 4-hydroxylase that is normally
accomplished by either dpy-18 or phy-2. The effects of the double mutation were
mimicked by small-molecule inhibitors of prolyl 4-hydroxylase, validating the
genetic results and suggesting that C. elegans can serve as a model system for
the discovery of new inhibitors.
PMID- 10781080
TI - Attention deficit/hyperactivity disorder children with a 7-repeat allele of the
dopamine receptor D4 gene have extreme behavior but normal performance on
critical neuropsychological tests of attention.
AB - An association of the dopamine receptor D4 (DRD4) gene located on chromosome
11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated
and replicated by multiple investigators. A specific allele [the 7-repeat of a 48
bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an
etiological factor in attentional deficits manifested in some children diagnosed
with this disorder. In the current study, we evaluated ADHD subgroups defined by
the presence or absence of the 7-repeat allele of the DRD4 gene, using
neuropsychological tests with reaction time measures designed to probe
attentional networks with neuroanatomical foci in D4-rich brain regions. Despite
the same severity of symptoms on parent and teacher ratings for the ADHD
subgroups, the average reaction times of the 7-present subgroup showed normal
speed and variability of response whereas the average reaction times of the 7
absent subgroup showed the expected abnormalities (slow and variable responses).
This was opposite the primary prediction of the study. The 7-present subgroup
seemed to be free of some of the neuropsychological abnormalities thought to
characterize ADHD.
PMID- 10781081
TI - Monitoring CD8 T cell responses to NY-ESO-1: correlation of humoral and cellular
immune responses.
AB - NY-ESO-1, a member of the cancer-testis family of antigens, is expressed in a
subset of a broad range of different human tumor types. Patients with advanced NY
ESO-1-expressing tumors frequently develop humoral immunity to NY-ESO-1, and
three HLA A2-restricted peptides were defined previously as targets for cytotoxic
CD8(+) T cells in a melanoma patient with NY-ESO-1 antibody. The objectives of
the present study were (i) to develop enzyme-linked immunospot (ELISPOT) and
tetramer assays to measure CD8(+) T cell responses to NY-ESO-1, (ii) to determine
the frequency of CD8(+) T cell responses to NY-ESO-1 in a series of HLA-A2
patients with NY-ESO-1 expressing tumors, (iii) to determine the relation between
CD8(+) T cell and humoral immune responses to NY-ESO-1, and (iv) to compare
results of NY-ESO-1 ELISPOT assays performed independently in two laboratories
with T cells from the same patients. NY-ESO-1 ELISPOT and tetramer assays with
excellent sensitivity, specificity, and reproducibility have been developed and
found to correlate with cytotoxicity assays. CD8(+) T cell responses to HLA-A2
restricted NY-ESO-1 peptides were detected in 10 of 11 patients with NY-ESO-1
antibody, but not in patients lacking antibody or in patients with NY-ESO-1
negative tumors. The results of ELISPOT assays were concordant in the two
laboratories, providing the basis for standardized monitoring of T cell responses
in patients receiving NY-ESO-1 vaccines.
PMID- 10781082
TI - CD4+ T cells derived from B cell-deficient mice inhibit the establishment of
peripheral B cell pools.
AB - We demonstrate that adoptive transfer of peritoneal cavity B cells fails to
replenish the peripheral B-1 cells in adult B cell-deficient (mu(-/-)) mice but
does replenish adult RAG-1(-/-) mice. We show that this lack of self
replenishment in mu(-/-) mice is mediated by strongly inhibitory, radiation
sensitive CD4(+) T cells that also function in cotransfer studies to block the
reconstitution of B-1 cells and inhibit accumulation of bone marrow-derived B-2
cells in the periphery in irradiated recipients. CD8(+) T cells from mu(-/-) do
not mediate this inhibition. The inhibitory CD4(+) T cells develop early in life,
because B-1 cell replenishment occurs normally when B-1 cells are transferred
into mu(-/-) neonates. Thus, we conclude that the presence of B cells in the
neonate conditions the CD4(+) T-cell population to permit the establishment and
maintenance of normal B cell pools throughout life.
PMID- 10781083
TI - Lsh, an SNF2/helicase family member, is required for proliferation of mature T
lymphocytes.
AB - Lsh (Hells) is closely related to SNF2/helicase family members that remodel
chromatin and thus regulate gene transcription. In the adult mouse Lsh is
expressed primarily in lymphoid tissue, showing the highest level in thymocytes.
Lsh gene expression can be induced in thymic pro-T cells by pre-T cell receptor
crosslinking and in mature T cells by T cell receptor crosslinking together with
costimulation via CD28. The time course of Lsh gene and protein expression
correlated closely with the onset of S phase of the cell cycle. To explore the
function of Lsh during lymphoid development or activation, we deleted the Lsh
gene by homologous recombination in ES cells. Fetal liver cells from Lsh-/- were
used as a source of hematopoietic precursors to reconstitute lymphoid development
in Rag2-/- mice. Lsh-/- (compared to Lsh+/+ or +/-) chimeras showed a modest
reduction in thymocyte numbers due to a partial arrest at the transition from the
CD4(-)CD8(-) stage to the CD4(+)CD8(+) stage of T cell development. Mature
peripheral lymphocytes were reduced in number to approximately 60% for T cells
and 40% for B cells; however, V(D)J recombination of the immune receptor genes
was normal. Although polyclonal activation of Lsh-/- T cells induced normal
levels of cytokines, cell proliferation was severely suppressed and cells
underwent apoptosis. Several genes involved in the regulation of apoptosis were
expressed normally with the exception of Bcl-2 that was actually elevated. These
findings demonstrate that Lsh is not obligatory for normal lymphoid development
but is essential for normal proliferation of peripheral T lymphocytes.
PMID- 10781084
TI - Plasticity in the organization and sequences of human KIR/ILT gene families.
AB - The approximately 1-Mb leukocyte receptor complex at 19q13.4 is a key polymorphic
immunoregion containing all of the natural killer-receptor KIR and related ILT
genes. When the organization of the leukocyte receptor complex was compared from
two haplotypes, the gene content in the KIR region varied dramatically, with
framework loci flanking regions of widely variable gene content. The ILT genes
were more stable in number except for ILT6, which was present only in one
haplotype. Analysis of Alu repeats and comparison of KIR gene sequences, which
are over 90% identical, are consistent with a recent origin. KIR genesis was
followed by extensive duplication/deletion as well as intergenic sequence
exchange, reminiscent of MHC class I genes, which provide KIR ligands.
PMID- 10781085
TI - Discovery of a spermatogenesis stage-specific ornithine decarboxylase antizyme:
antizyme 3.
AB - Previous studies with mice overproducing ornithine decarboxylase have
demonstrated the importance of polyamine homeostasis for normal mammalian
spermatogenesis. The present study introduces a likely key player in the
maintenance of proper polyamine homeostasis during spermatogenesis. Antizyme 3 is
a paralog of mammalian ornithine decarboxylase antizymes. Like its previously
described counterparts, antizymes 1 and 2, it inhibits ornithine decarboxylase,
which catalyzes the synthesis of putrescine. Earlier work has shown that the
coding sequences for antizymes 1 and 2 are in two different, partially
overlapping reading frames. Ribosomes translate the first reading frame, and just
before the stop codon for that frame, they shift to the second reading frame to
synthesize a trans-frame product. The efficiency of this frameshifting depends on
polyamine concentration, creating an autoregulatory circuit. Antizyme 3 cDNA has
the same arrangement of reading frames and a potential shift site with definite,
although limited, homology to its evolutionarily distant antizyme 1 and 2
counterparts. In contrast to antizymes 1 and 2, which are widely expressed
throughout the body, antizyme 3 transcription is restricted to testis germ cells.
Expression starts early in spermiogenesis and finishes in the late spermatid
phase. The potential significance of antizyme 3 expression during spermatogenesis
is discussed in this paper.
PMID- 10781086
TI - L-amino acid sensing by the extracellular Ca2+-sensing receptor.
AB - The extracellular calcium (Ca(2+)(o))-sensing receptor (CaR) recognizes and
responds to (i.e., "senses") Ca(2+)(o) as its principal physiological ligand. In
the present studies, we document that the CaR is activated not only by
extracellular calcium ions but also by amino acids, establishing its capacity to
sense nutrients of two totally different classes. l-Amino acids, especially
aromatic amino acids, including l-phenylalanine and l-tryptophan,
stereoselectively mobilized Ca(2+) ions in the presence of the CaR agonists,
Ca(2+)(o), gadolinium (Gd(3+)(o)), and spermine in fura-2-loaded human embryonic
kidney (HEK-293) cells stably transfected with the human CaR. l-amino acid
dependent effects were observed above, but not below, a threshold level of
Ca(2+)(o) of approximately 1.0 mM. l-Amino acids, particularly aromatic amino
acids, also stereoselectively enhanced the sensitivity of the CaR to its
agonists, Ca(2+)(o) and spermine. Branched-chain amino acids were almost
inactive, and charged amino acids, including arginine and lysine, were much less
effective than aromatic and other amino acids. l-amino acid mixtures emulating
the amino acid composition of fasting human plasma reproduced the effects of high
concentrations of individual l-amino acids on Ca(2+) mobilization and enhanced
the sensitivity of the CaR to Ca(2+)(o). The data presented herein identify the
CaR as a molecular target for aromatic and other l-amino acids. Thus, the CaR can
integrate signals arising from distinct classes of nutrients: mineral ions and
amino acids. The actions of l-amino acids on the CaR may provide explanations for
several long recognized but poorly understood actions of dietary protein on
calcium metabolism.
PMID- 10781087
TI - Mutations in the tumor suppressors Smad2 and Smad4 inactivate transforming growth
factor beta signaling by targeting Smads to the ubiquitin-proteasome pathway.
AB - Biological signals for transforming growth factor beta (TGF-beta) are transduced
through transmembrane serine/threonine kinase receptors that signal to a family
of intracellular mediators known as Smads. Smad2 and Smad4 are important for
transcriptional and antiproliferative responses to TGF-beta, and their
inactivation in human cancers indicates that they are tumor suppressors. A
missense mutation at a conserved arginine residue in the amino-terminal MH1
domain of both Smad2 and Smad4 has been identified in tumors from patients with
colorectal and pancreatic cancers, respectively. However, the mechanism whereby
this mutation interferes with Smad activity is uncertain. Here we show that these
mutations do not disrupt activation of Smads, including receptor-mediated
phosphorylation of Smad2, Smad2/Smad4 heteromeric complex formation, and Smad
nuclear translocation. In contrast, we demonstrate that the mutant Smads are
degraded rapidly in comparison with their wild-type counterparts. We show that
this decrease in Smad protein stability occurs through induction of Smad
ubiquitination by pathways involving the UbcH5 family of ubiquitin ligases. These
studies thus reveal a mechanism for tumorigenesis whereby genetic defects in
Smads induce their degradation through the ubiquitin-mediated pathway.
PMID- 10781088
TI - Conditional expression of a Gi-coupled receptor causes ventricular conduction
delay and a lethal cardiomyopathy.
AB - Cardiomyopathy is a major cause of morbidity and mortality. Ventricular
conduction delay, as shown by prolonged deflections in the electrocardiogram
caused by delayed ventricular contraction (wide QRS complex), is a common feature
of cardiomyopathy and is associated with a poor prognosis. Although the G(i)
signaling pathway is up-regulated in certain cardiomyopathies, previous studies
suggested this up-regulation was compensatory rather than a potential cause of
the disease. Using the tetracycline transactivator system and a modified G(i)
coupled receptor (Ro1), we provide evidence that increased G(i) signaling in mice
can result in a lethal cardiomyopathy associated with a wide QRS complex
arrhythmia. Induced expression of Ro1 in adult mice resulted in a >90% mortality
rate at 16 wk, whereas suppression of Ro1 expression after 8 wk protected mice
from further mortality and allowed partial improvement in systolic function.
Results of DNA-array analysis of over 6,000 genes from hearts expressing Ro1 are
consistent with hyperactive G(i) signaling. DNA-array analysis also identified
known markers of cardiomyopathy and hundreds of previously unknown potential
diagnostic markers and therapeutic targets for this syndrome. Our system allows
cardiomyopathy to be induced and reversed in adult mice, providing an
unprecedented opportunity to dissect the role of G(i) signaling in causing
cardiac pathology.
PMID- 10781089
TI - Human herpesvirus 8 infections in the Amsterdam Cohort Studies (1984-1997):
analysis of seroconversions to ORF65 and ORF73.
AB - We have shown previously that human herpesvirus 8 (HHV8) seroconversion for
antibodies to the latency-associated nuclear antigen encoded by ORF73 and/or the
lytic capsid antigen (vp19) encoded by ORF65 is associated with orogenital
contact and is strongly linked to the development of Kaposi's sarcoma among HIV
infected individuals in the Amsterdam Cohort Studies. Here, we investigate the
relationship between seroconversion to these antigens and primary HHV8 infection.
Between 1984 and 1997, 215 HHV8 seroconversions to ORF73 (106 cases or 49%)
and/or to ORF65 (159 cases or 74%) were recorded in the cohort of homosexual men.
The HHV8 seroconversion rate among HIV-infected homosexual men (6.2 per 100
person years) was consistently higher than among HIV-uninfected men (2.6 per 100
person years). In HIV-infected but not in uninfected individuals, seroconversion
to ORF73/latency-associated nuclear antigen precedes that to ORF65/vp19. Antibody
levels to both ORF65- and ORF73-encoded antigens were higher in HIV-infected than
in HIV-uninfected men, and among HIV-seropositives, antibody levels to ORF65/vp19
rise even higher with declining CD4 cell counts and peak with Kaposi's sarcoma
development, suggesting continuing and increasing viral replication. In 10.3% of
HHV8 seroconversions, transient serum viremia could be demonstrated before or at
seroconversion. Together with the previously reported link between unprotected
orogenital sex and HHV8 seroconversion, our observations suggest that HHV8
seroconversions result from primary infections.
PMID- 10781090
TI - 15-deoxy-delta 12,14-prostaglandin J2 inhibits multiple steps in the NF-kappa B
signaling pathway.
AB - Prostaglandin J(2) (PGJ(2)) and its metabolites Delta(12)-PGJ(2) and 15-deoxy
Delta(12,14)-PGJ(2) (15d-PGJ(2)) are naturally occurring derivatives of
prostaglandin D(2) that have been suggested to exert antiinflammatory effects in
vivo. 15d-PGJ(2) is a high-affinity ligand for the peroxisome proliferator
activated receptor gamma (PPARgamma) and has been demonstrated to inhibit the
induction of inflammatory response genes, including inducible NO synthase and
tumor necrosis factor alpha, in a PPARgamma-dependent manner. We report here that
15d-PGJ(2) potently inhibits NF-kappaB-dependent transcription by two additional
PPARgamma-independent mechanisms. Several lines of evidence suggest that 15d
PGJ(2) directly inhibits NF-kappaB-dependent gene expression through covalent
modifications of critical cysteine residues in IkappaB kinase and the DNA-binding
domains of NF-kappaB subunits. These mechanisms act in combination to inhibit
transactivation of the NF-kappaB target gene cyclooxygenase 2. Direct inhibition
of NF-kappaB signaling by 15d-PGJ(2) may contribute to negative regulation of
prostaglandin biosynthesis and inflammation, suggesting additional approaches to
the development of antiinflammatory drugs.
PMID- 10781091
TI - Development of an extrachromosomal cloning vector system for use in Borrelia
burgdorferi.
AB - Molecular genetic analysis of Borrelia burgdorferi, the cause of Lyme disease,
has been hampered by the absence of any means of efficient generation,
identification, and complementation of chromosomal and plasmid null gene mutants.
The similarity of borrelial G + C content to that of Gram-positive organisms
suggested that a wide-host-range plasmid active in Gram-positive bacteria might
also be recognized by borrelial DNA replication machinery. One such plasmid,
pGK12, is able to propagate in both Gram-positive and Gram-negative bacteria and
carries erythromycin and chloramphenicol resistance markers. pGK12 propagated
extrachromosomally in B. burgdorferi B31 after electroporation but conferred only
erythromycin resistance. pGK12 was used to express enhanced green fluorescent
protein in B31 under the control of the flaB promoter. Escherichia coli
transformed with pGK12 DNA extracted from B31 expressing only erythromycin
resistance developed both erythromycin and chloramphenicol resistance, and
plasmid DNA isolated from these transformed E. coli had a restriction pattern
similar to the original pGK12. Our data indicate that the replicons of pGK12 can
provide the basis to continue developing efficient genetic systems for B.
burgdorferi together with the erythromycin resistance and reporter egfp genes.
PMID- 10781092
TI - The Pseudomonas syringae Hrp pathogenicity island has a tripartite mosaic
structure composed of a cluster of type III secretion genes bounded by
exchangeable effector and conserved effector loci that contribute to parasitic
fitness and pathogenicity in plants.
AB - The plant pathogenic bacterium Pseudomonas syringae is divided into pathovars
differing in host specificity, with P. syringae pv. syringae (Psy) and P.
syringae pv. tomato (Pto) representing particularly divergent pathovars. P.
syringae hrp/hrc genes encode a type III protein secretion system that appears to
translocate Avr and Hop effector proteins into plant cells. DNA sequence analysis
of the hrp/hrc regions in Psy 61, Psy B728a, and Pto DC3000 has revealed a Hrp
pathogenicity island (Pai) with a tripartite mosaic structure. The hrp/hrc gene
cluster is conserved in all three strains and is flanked by a unique exchangeable
effector locus (EEL) and a conserved effector locus (CEL). The EELs begin 3 nt
downstream of the stop codon of hrpK and end, after 2.5-7.3 kb of dissimilar
intervening DNA with tRNA(Leu)-queA-tgt sequences that are also found in
Pseudomonas aeruginosa but without linkage to any Hrp Pai sequences. The EELs
encode diverse putative effectors, including HopPsyA (HrmA) in Psy 61 and
proteins similar to AvrPphE and the AvrB/AvrC/AvrPphC and AvrBsT/AvrRxv/YopJ
protein families in Psy B728a. The EELs also contain mobile genetic element
sequences and have a G + C content significantly lower than the rest of the Hrp
Pai or the P. syringae genome. The CEL carries at least seven ORFs that are
conserved between Psy B728a and Pto DC3000. Deletion of the Pto DC3000 EEL
slightly reduces bacterial growth in tomato, whereas deletion of a large portion
of the CEL strongly reduces growth and abolishes pathogenicity in tomato.
PMID- 10781093
TI - The murine homolog of human Nectin1delta serves as a species nonspecific mediator
for entry of human and animal alpha herpesviruses in a pathway independent of a
detectable binding to gD.
AB - The full-length cDNA of the murine homolog of human nectin1delta (mNectin1delta),
also known as human poliovirus receptor related 1 (PRR1) or herpesvirus entry
mediator C, was cloned and showed a >90% identity with its human counterpart.
mNectin1delta is expressed in some murine cell lines, exemplified by NIH 3T3 and
L cells, and in murine tissues. It mediates entry of an extended range of herpes
simplex virus (HSV) strains, porcine pseudorabies virus (PrV), and bovine
herpesvirus 1. A soluble form of the mediator blocked infectivity in
mNectin1delta and human nectin1delta (hNectin1delta)-expressing cells, suggesting
a physical interaction of the mediator with virions. The higher concentrations of
soluble mNectin1 required to block infectivity relative to soluble hNectin1
suggest that the target of the two molecules is not identical. Entry of HSV, but
not PrV, was blocked by soluble mNectin1delta in NIH 3T3 and L cells. Two
features were unexpected. First, soluble mNectin1delta failed to physically
interact with HSV glycoprotein D (gD) at a detectable level, although it
interacted physically with virions. Second, coexpression of mNectin1delta and HSV
gD did not restrict HSV or PrV infection, whereas coexpression of hNectin and gD
did restrict infection, suggesting that mNectin1delta fails to be sequestered by
HSV gD. We conclude that mNectin1delta serves as a species-nonspecific mediator
for entry of the human and animal alphaherpesviruses. This activity, at least for
HSV, is independent of a detectable binding to gD.
PMID- 10781094
TI - A self-recombining bacterial artificial chromosome and its application for
analysis of herpesvirus pathogenesis.
AB - A self-recombining bacterial artificial chromosome (BAC) containing the 142-kb
pseudorabies virus genome was constructed such that the viral genome is rapidly
excised from the BAC vector backbone on delivery into mammalian cells. The
recombination is mediated by loxP sites in the plasmid and Cre recombinase
encoded within the BAC vector. A synthetic intron inserted in the middle of the
cre ORF completely inhibits recombination in Escherichia coli, but is spliced out
after delivery of the plasmid into mammalian cells. Recombination is efficient,
and pure virus lacking the BAC vector backbone is immediately isolated from
transfected mammalian cells without the need of serial passage or plaque
purification.
PMID- 10781095
TI - Genome-wide analysis of vaccinia virus protein-protein interactions.
AB - To detect interactions between proteins of vaccinia virus, we carried out a
comprehensive two-hybrid analysis to assay every pairwise combination. We
constructed an array of yeast transformants that contained each of the 266
predicted viral ORFs as Gal4 activation domain hybrid proteins. The array was
individually mated to transformants containing each ORF as a Gal4-DNA-binding
domain hybrid, and diploids expressing the two-hybrid reporter gene were
identified. Of the approximately 70,000 combinations, we found 37 protein-protein
interactions, including 28 that were previously unknown. In some cases, e.g.,
late transcription factors, both proteins were known to have related roles
although there was no prior evidence of physical associations. For some other
interactions, neither protein had a known role. In the majority of cases,
however, one of the interacting proteins was known to be involved in DNA
replication, transcription, virion structure, or host evasion, thereby providing
a clue to the role of the other uncharacterized protein in a specific process.
PMID- 10781096
TI - Fiber diffraction of synthetic alpha-synuclein filaments shows amyloid-like cross
beta conformation.
AB - Filamentous inclusions made of alpha-synuclein constitute the defining
neuropathological characteristic of Parkinson's disease, dementia with Lewy
bodies, and multiple system atrophy. Rare familial cases of Parkinson's disease
are associated with mutations A53T and A30P in alpha-synuclein. We report here
the assembly properties and secondary structure characteristics of recombinant
alpha-synuclein. Carboxy-terminally truncated human alpha-synuclein (1-87) and (1
120) showed the fastest rates of assembly, followed by human A53T alpha
synuclein, and rat and zebra finch alpha-synuclein. Wild-type human alpha
synuclein and the A30P mutant showed slower rates of assembly. Upon shaking,
filaments formed within 48 h at 37 degrees C. The related proteins beta- and
gamma-synuclein only assembled after several weeks of incubation. Synthetic human
alpha-synuclein filaments were decorated by an antibody directed against the
carboxy-terminal 10 amino acids of alpha-synuclein, as were filaments extracted
from dementia with Lewy bodies and multiple system atrophy brains. Circular
dichroism spectroscopy indicated that alpha-synuclein undergoes a conformational
change from random coil to beta-sheet structure during assembly. X-ray
diffraction and electron diffraction of the alpha-synuclein assemblies showed a
cross-beta conformation characteristic of amyloid.
PMID- 10781097
TI - Prostaglandin D synthase gene is involved in the regulation of non-rapid eye
movement sleep.
AB - To examine the function of prostaglandin (PG) D synthase (PGDS) gene, as well as
endogenously produced PGD(2) in sleep regulation in vivo, we generated transgenic
(TG) mice that overexpress human PGDS gene to study their sleep behavior.
Although no difference was observed in the sleep/wake patterns between wild-type
and TG mice, a striking time-dependent increase in non-rapid eye movement (NREM),
but not in rapid eye movement (REM), sleep was observed in two independent lines
of TG mice after stimulation by tail clipping. Concomitantly, the spontaneous
locomotor activity of TG animals was drastically decreased in response to the
tail clip. Induction of NREM sleep in TG mice was positively correlated with the
PGD(2) production in the brain. Sleep, locomotion, and PGD(2) content were
essentially unchanged in wild-type mice after tail clipping. The results with TG
mice demonstrate the involvement of the PGDS gene in the regulation of NREM
sleep.
PMID- 10781098
TI - Colocalization and coassembly of two human brain M-type potassium channel
subunits that are mutated in epilepsy.
AB - Acetylcholine excites many central and autonomic neurons through inhibition of M
channels, slowly activating, noninactivating voltage-gated potassium channels. We
here provide information regarding the in vivo distribution and biochemical
characteristics of human brain KCNQ2 and KCNQ3, two channel subunits that form M
channels when expressed in vitro, and, when mutated, cause the dominantly
inherited epileptic syndrome, benign neonatal familial convulsions. KCNQ2 and
KCNQ3 proteins are colocalized in a somatodendritic pattern on pyramidal and
polymorphic neurons in the human cortex and hippocampus. Immunoreactivity for
KCNQ2, but not KCNQ3, is also prominent in some terminal fields, suggesting a
presynaptic role for a distinct subgroup of M-channels in the regulation of
action potential propagation and neurotransmitter release. KCNQ2 and KCNQ3 can be
coimmunoprecipitated from brain lysates. Further, KCNQ2 and KCNQ3 are
coassociated with tubulin and protein kinase A within a Triton X-100-insoluble
protein complex. This complex is not associated with low-density membrane rafts
or with N-methyl-d-aspartate receptors, PSD-95 scaffolding proteins, or other
potassium channels tested. Our studies thus provide a view of a signaling complex
that may be important for cognitive function as well as epilepsy. Analysis of
this complex may shed light on the unknown transduction pathway linking
muscarinic acetylcholine receptor activation to M-channel inhibition.
PMID- 10781099
TI - A decamer duplication in the 3' region of the BRI gene originates an amyloid
peptide that is associated with dementia in a Danish kindred.
AB - Familial Danish dementia (FDD), also known as heredopathia ophthalmo-oto
encephalica, is an autosomal dominant disorder characterized by cataracts,
deafness, progressive ataxia, and dementia. Neuropathological findings include
severe widespread cerebral amyloid angiopathy, hippocampal plaques, and
neurofibrillary tangles, similar to Alzheimer's disease. N-terminal sequence
analysis of isolated leptomeningeal amyloid fibrils revealed homology to ABri,
the peptide originated by a point mutation at the stop codon of gene BRI in
familial British dementia. Molecular genetic analysis of the BRI gene in the
Danish kindred showed a different defect, namely the presence of a 10-nt
duplication (795-796insTTTAATTTGT) between codons 265 and 266, one codon before
the normal stop codon 267. The decamer duplication mutation produces a frame
shift in the BRI sequence generating a larger-than-normal precursor protein, of
which the amyloid subunit (designated ADan) comprises the last 34 C-terminal
amino acids. This de novo-created amyloidogenic peptide, associated with a
genetic defect in the Danish kindred, stresses the importance of amyloid
formation as a causative factor in neurodegeneration and dementia.
PMID- 10781100
TI - D-serine is an endogenous ligand for the glycine site of the N-methyl-D-aspartate
receptor.
AB - Functional activity of N-methyl-D-aspartate (NMDA) receptors requires both
glutamate binding and the binding of an endogenous coagonist that has been
presumed to be glycine, although D-serine is a more potent agonist. Localizations
of D-serine and it biosynthetic enzyme serine racemase approximate the
distribution of NMDA receptors more closely than glycine. We now show that
selective degradation of d-serine with D-amino acid oxidase greatly attenuates
NMDA receptor-mediated neurotransmission as assessed by using whole-cell patch
clamp recordings or indirectly by using biochemical assays of the sequelae of
NMDA receptor-mediated calcium flux. The inhibitory effects of the enzyme are
fully reversed by exogenously applied D-serine, which by itself did not
potentiate NMDA receptor-mediated synaptic responses. Thus, D-serine is an
endogenous modulator of the glycine site of NMDA receptors and fully occupies
this site at some functional synapses.
PMID- 10781101
TI - Brain size does not predict general cognitive ability within families.
AB - Hominid brain size increased dramatically in the face of apparently severe
associated evolutionary costs. This suggests that increasing brain size must have
provided some sort of counterbalancing adaptive benefit. Several recent studies
using magnetic resonance imaging (MRI) have indicated that a substantial
correlation (mean r = approximately 0.4) exists between brain size and general
cognitive performance, consistent with the hypothesis that the payoff for
increasing brain size was greater general cognitive ability. However, these
studies confound between-family environmental influences with direct
genetic/biological influences. To address this problem, within-family (WF)
sibling differences for several neuroanatomical measures were correlated to WF
scores on a diverse battery of cognitive tests in a sample of 36 sibling pairs.
WF correlations between neuroanatomy and general cognitive ability were
essentially zero, although moderate correlations were found between prefrontal
volumes and the Stroop test (known to involve prefrontal cortex). These findings
suggest that nongenetic influences play a role in brain volume/cognitive ability
associations. Actual direct genetic/biological associations may be quite small,
and yet still may be strong enough to account for hominid brain evolution.
PMID- 10781102
TI - Potent blockade of sodium channels and protection of brain tissue from ischemia
by BIII 890 CL.
AB - We have synthesized a new benzomorphan derivative, 2R-[2alpha,3(S*), 6alpha]
1,2,3,4,5,6-hexahydro-6,11, 11-trimethyl-3-[2-(phenylmethoxy)propyl]-2, 6-methano
3-benzazocin-10-ol hydrochloride (BIII 890 CL), which displaced
[(3)H]batrachotoxinin A-20alpha-benzoate from neurotoxin receptor site 2 of the
Na(+) channel in rat brain synaptosomes (IC(50) = 49 nM), but exhibited only low
affinity for 65 other receptors and ion channels. BIII 890 CL inhibited Na(+)
channels in cells transfected with type IIA Na(+) channel alpha subunits and
shifted steady-state inactivation curves to more negative potentials. The IC(50)
value for the inactivated Na(+) channel was much lower (77 nM) than for Na(+)
channels in the resting state (18 microM). Point mutations F1764A and Y1771A in
transmembrane segment S6 in domain IV of the alpha subunit reduced the voltage-
and frequency-dependent block, findings which suggest that BIII 890 CL binds to
the local anesthetic receptor site in the pore. BIII 890 CL inhibited veratridine
induced glutamate release in brain slices, as well as glutamate release and
neurotoxicity in cultured cortical neurons. BIII 890 CL (3-30 mg/kg s.c.) reduced
lesion size in mice and rats when administered 5 min after permanent focal
cerebral ischemia at doses that did not impair motor coordination. In contrast to
many other agents, BIII 890 CL was neuroprotective in both cortical and
subcortical regions of the rat brain. Our results demonstrate that BIII 890 CL is
a potent, selective, and highly use-dependent Na(+) channel blocker that protects
brain tissue from the deleterious effects of focal cerebral ischemia in rodents.
PMID- 10781103
TI - Elevated subsarcolemmal Ca2+ in mdx mouse skeletal muscle fibers detected with
Ca2+-activated K+ channels.
AB - Duchenne muscular dystrophy results from the lack of dystrophin, a cytoskeletal
protein associated with the inner surface membrane, in skeletal muscle. The
cellular mechanisms responsible for the progressive skeletal muscle degeneration
that characterizes the disease are still debated. One hypothesis suggests that
the resting sarcolemmal permeability for Ca(2+) is increased in dystrophic
muscle, leading to Ca(2+) accumulation in the cytosol and eventually to protein
degradation. However, more recently, this hypothesis was challenged seriously by
several groups that did not find any significant increase in the global
intracellular Ca(2+) in muscle from mdx mice, an animal model of the human
disease. In the present study, using plasma membrane Ca(2+)-activated K(+)
channels as subsarcolemmal Ca(2+) probe, we tested the possibility of a Ca(2+)
accumulation at the restricted subsarcolemmal level in mdx skeletal muscle
fibers. Using the cell-attached configuration of the patch-clamp technique, we
demonstrated that the voltage threshold for activation of high conductance Ca(2+)
activated K(+) channels is significantly lower in mdx than in control muscle,
suggesting a higher subsarcolemmal [Ca(2+)]. In inside-out patches, we showed
that this shift in the voltage threshold for high conductance Ca(2+)-activated
K(+) channel activation could correspond to a approximately 3-fold increase in
the subsarcolemmal Ca(2+) concentration in mdx muscle. These data favor the
hypothesis according to which an increased calcium entry is associated with the
absence of dystrophin in mdx skeletal muscle, leading to Ca(2+) overload at the
subsarcolemmal level.
PMID- 10781104
TI - The molecular physiology of heavy metal transport in the Zn/Cd hyperaccumulator
Thlaspi caerulescens.
AB - An integrated molecular and physiological investigation of the fundamental
mechanisms of heavy metal accumulation was conducted in Thlaspi caerulescens, a
Zn/Cd-hyperaccumulating plant species. A heavy metal transporter cDNA, ZNT1, was
cloned from T. caerulescens through functional complementation in yeast and was
shown to mediate high-affinity Zn(2+) uptake as well as low-affinity Cd(2+)
uptake. It was found that this transporter is expressed at very high levels in
roots and shoots of the hyperaccumulator. A study of ZNT1 expression and high
affinity Zn(2+) uptake in roots of T. caerulescens and in a related
nonaccumulator, Thlaspi arvense, showed that alteration in the regulation of ZNT1
gene expression by plant Zn status results in the overexpression of this
transporter and in increased Zn influx in roots of the hyperaccumulating Thlaspi
species. These findings yield insights into the molecular regulation and control
of plant heavy metal and micronutrient accumulation and homeostasis, as well as
provide information that will contribute to the advancement of phytoremediation
by the future engineering of plants with improved heavy metal uptake and
tolerance.
PMID- 10781105
TI - A longevity assurance gene homolog of tomato mediates resistance to Alternaria
alternata f. sp. lycopersici toxins and fumonisin B1.
AB - The phytopathogenic fungus Alternaria alternata f. sp. lycopersici (AAL) produces
toxins that are essential for pathogenicity of the fungus on tomato (Lycopersicon
esculentum). AAL toxins and fumonisins of the unrelated fungus Fusarium
moniliforme are sphinganine-analog mycotoxins (SAMs), which cause inhibition of
sphingolipid biosynthesis in vitro and are toxic for some plant species and
mammalian cell lines. Sphingolipids can be determinants in the proliferation or
death of cells. We investigated the tomato Alternaria stem canker (Asc) locus,
which mediates resistance to SAM-induced apoptosis. Until now, mycotoxin
resistance of plants has been associated with detoxification and altered affinity
or absence of the toxin targets. Here we show that SAM resistance of tomato is
determined by Asc-1, a gene homologous to the yeast longevity assurance gene LAG1
and that susceptibility is associated with a mutant Asc-1. Because both
sphingolipid synthesis and LAG1 facilitate endocytosis of
glycosylphosphatidylinositol-anchored proteins in yeast, we propose a role for
Asc-1 in a salvage mechanism of sphingolipid-depleted plant cells.
PMID- 10781106
TI - Ca2+ channels at the plasma membrane of stomatal guard cells are activated by
hyperpolarization and abscisic acid.
AB - In stomatal guard cells of higher-plant leaves, abscisic acid (ABA) evokes
increases in cytosolic free Ca(2+) concentration ([Ca(2+)](i)) by means of Ca(2+)
entry from outside and release from intracellular stores. The mechanism(s) for
Ca(2+) flux across the plasma membrane is poorly understood. Because [Ca(2+)](i)
increases are voltage-sensitive, we suspected a Ca(2+) channel at the guard cell
plasma membrane that activates on hyperpolarization and is regulated by ABA. We
recorded single-channel currents across the Vicia guard cell plasma membrane
using Ba(2+) as a charge-carrying ion. Both cell-attached and excised-patch
measurements uncovered single-channel events with a maximum conductance of 12.8
+/- 0.4 pS and a high selectivity for Ba(2+) (and Ca(2+)) over K(+) and Cl(-).
Unlike other Ca(2+) channels characterized to date, these channels rectified
strongly toward negative voltages with an open probability (P(o)) that increased
with [Ba(2+)] outside and decreased roughly 10-fold when [Ca(2+)](i) was raised
from 200 nM to 2 microM. Adding 20 microM ABA increased P(o), initially by 63- to
260-fold; in both cell-attached and excised patches, it shifted the voltage
sensitivity for channel activation, and evoked damped oscillations in P(o) with
periods near 50 s. A similar, but delayed response was observed in 0.1 microM
ABA. These results identify a Ca(2+)-selective channel that can account for
Ca(2+) influx and increases in [Ca(2+)](i) triggered by voltage and ABA, and they
imply a close physical coupling at the plasma membrane between ABA perception and
Ca(2+) channel control.
PMID- 10781107
TI - Toc34 is a preprotein receptor regulated by GTP and phosphorylation.
AB - Most proteins present in chloroplasts are synthesized in the cytosol and are
posttranslationally translocated into the organelle. A multicomponent
translocation machinery located in both the outer and the inner envelope of
chloroplasts was identified, but the mode of action of many subunits remains
unclear. Here, we describe the regulation of an early step of translocation
occurring at the outer envelope. The outer envelope translocon subunit Toc34 can
be phosphorylated, and GTP binding is regulated by phosphorylation. In vitro,
Toc34 acts as a receptor for proteins containing a chloroplast-targeting signal.
Interaction of Toc34 with the transit peptide is highly regulated and depends on
GTP binding to Toc34 and on phosphorylation of the transit peptide of the
preprotein.
PMID- 10781108
TI - Conserved plant genes with similarity to mammalian de novo DNA
methyltransferases.
AB - DNA methylation plays a critical role in controlling states of gene activity in
most eukaryotic organisms, and it is essential for proper growth and development.
Patterns of methylation are established by de novo methyltransferases and
maintained by maintenance methyltransferase activities. The Dnmt3 family of de
novo DNA methyltransferases has recently been characterized in animals. Here we
describe DNA methyltransferase genes from both Arabidopsis and maize that show a
high level of sequence similarity to Dnmt3, suggesting that they encode plant de
novo methyltransferases. Relative to all known eukaryotic methyltransferases,
these plant proteins contain a novel arrangement of the motifs required for DNA
methyltransferase catalytic activity. The N termini of these methyltransferases
contain a series of ubiquitin-associated (UBA) domains. UBA domains are found in
several ubiquitin pathway proteins and in DNA repair enzymes such as Rad23, and
they may be involved in ubiquitin binding. The presence of UBA domains provides a
possible link between DNA methylation and ubiquitin/proteasome pathways.
PMID- 10781110
TI - Cadmium and iron transport by members of a plant metal transporter family in
Arabidopsis with homology to Nramp genes.
AB - Metal cation homeostasis is essential for plant nutrition and resistance to toxic
heavy metals. Many plant metal transporters remain to be identified at the
molecular level. In the present study, we have isolated AtNramp cDNAs from
Arabidopsis and show that these genes complement the phenotype of a metal uptake
deficient yeast strain, smf1. AtNramps show homology to the Nramp gene family in
bacteria, yeast, plants, and animals. Expression of AtNramp cDNAs increases
Cd(2+) sensitivity and Cd(2+) accumulation in yeast. Furthermore, AtNramp3 and
AtNramp4 complement an iron uptake mutant in yeast. This suggests possible roles
in iron transport in plants and reveals heterogeneity in the functional
properties of Nramp transporters. In Arabidopsis, AtNramps are expressed in both
roots and aerial parts under metal replete conditions. Interestingly, AtNramp3
and AtNramp4 are induced by iron starvation. Disruption of the AtNramp3 gene
leads to slightly enhanced cadmium resistance of root growth. Furthermore,
overexpression of AtNramp3 results in cadmium hypersensitivity of Arabidopsis
root growth and increased accumulation of Fe, on Cd(2+) treatment. Our results
show that Nramp genes in plants encode metal transporters and that AtNramps
transport both the metal nutrient Fe and the toxic metal cadmium.
PMID- 10781109
TI - Specific and heritable genetic interference by double-stranded RNA in Arabidopsis
thaliana.
AB - We investigated the potential of double-stranded RNA interference (RNAi) with
gene activity in Arabidopsis thaliana. To construct transformation vectors that
produce RNAs capable of duplex formation, gene-specific sequences in the sense
and antisense orientations were linked and placed under the control of a strong
viral promoter. When introduced into the genome of A. thaliana by Agrobacterium
mediated transformation, double-stranded RNA-expressing constructs corresponding
to four genes, AGAMOUS (AG), CLAVATA3, APETALA1, and PERIANTHIA, caused specific
and heritable genetic interference. The severity of phenotypes varied between
transgenic lines. In situ hybridization revealed a correlation between a
declining AG mRNA accumulation and increasingly severe phenotypes in AG (RNAi)
mutants, suggesting that endogenous mRNA is the target of double-stranded RNA
mediated genetic interference. The ability to generate stably heritable RNAi and
the resultant specific phenotypes allows us to selectively reduce gene function
in A. thaliana.
PMID- 10781111
TI - Some transformations of color information from lateral geniculate nucleus to
striate cortex.
AB - We have recorded the responses of single cells in the lateral geniculate nucleus
(LGN) and striate cortex of the macaque monkey. The response characteristics of
neurons at these successive visual processing levels were examined with
isoluminant gratings, cone-isolating gratings, and luminance-varying gratings.
The main findings were: (i) Whereas almost all parvo- and konio-cellular LGN
cells are of just two opponent-cell types, either differencing the L and M cones
(L(o) and M(o) cells), or the S vs. L + M cones (S(o) cells), relatively few
striate cortex simple cells show chromatic responses along these two cardinal LGN
axes. Rather, most are shifted away from these LGN chromatic axes as a result of
combining the outputs (or the transformed outputs) of S(o) with those of L(o)
and/or M(o) cells. (ii) LGN cells on average process color information linearly,
exhibiting sinusoidal changes in firing rate to isoluminant stimuli that vary
sinusoidally in cone contrast as a function of color angle. Some striate cortex
simple cells also give linear responses, but most show an expansive response
nonlinearity, resulting in narrower chromatic tuning on average at this level.
(iii) There are many more +S(o) than -S(o) LGN cells, but at the striate cortex
level -S(o) input to simple cells is as common as +S(o) input. (iv) Overall, the
contribution of the S-opponent path is doubled at the level of the striate
cortex, relative to that at the LGN.
PMID- 10781112
TI - How reliable are human phylogenetic hypotheses?
AB - Cladistic analysis of cranial and dental evidence has been widely used to
generate phylogenetic hypotheses about humans and their fossil relatives.
However, the reliability of these hypotheses has never been subjected to external
validation. To rectify this, we applied identical methods to equivalent evidence
from two groups of extant higher primates for whom reliable molecular phylogenies
are available, the hominoids and papionins. We found that the phylogenetic
hypotheses based on the craniodental data were incompatible with the molecular
phylogenies for the groups. Given the robustness of the molecular phylogenies,
these results indicate that little confidence can be placed in phylogenies
generated solely from higher primate craniodental evidence. The corollary of this
is that existing phylogenetic hypotheses about human evolution are unlikely to be
reliable. Accordingly, new approaches are required to address the problem of
hominin phylogeny.
PMID- 10781113
TI - Shared cognitive representations of perceptual and semantic structures of basic
colors in Chinese and English.
AB - Two perceptual structures (based on colors) and one semantic structure (based on
names) of eight basic chromatic colors were obtained from three judged similarity
tasks for 41 Mandarin Chinese-speaking females in Taiwan and 35 English-speaking
females in the United States. Major findings include the following: (i) there are
robust and reliable individual differences among individuals, (ii) the structures
for Chinese and English speakers are similar, and (iii) the semantic structure of
color names is similar to the perceptual structures of colors. The results place
strong constraints on theories relating to individual differences, linguistic
relativity, and the relation of perceptual and semantic structures for colors.
PMID- 10781114
TI - Recent advances in understanding the actions and toxicity of nitrous oxide.
PMID- 10781116
TI - Randomised double-blind comparison of fentanyl, mivacurium or placebo to
facilitate laryngeal mask airway insertion.
AB - In a double-blind randomised study, we compared conditions during insertion of
the laryngeal mask airway in 150 patients who received either fentanyl 1
microg.kg-1, mivacurium 0.04 mg.kg-1 or normal saline, before induction of
anaesthesia with propofol 2 mg.kg-1. Insertion conditions, including mouth
opening, swallowing, gagging or coughing, head or limb movement and ease of
insertion, were each graded using a three-point scale. The median (interquartile
range) summed insertion scores were more favourable with the use of fentanyl [8.0
(7.0-9.0)] and mivacurium [7.5 (6.8-8.3)] than with normal saline [9.0 (7.8
10.3); p < 0.01]. Fentanyl and mivacurium decreased swallowing and head or limb
movement, and mivacurium improved mouth opening. Insertion conditions were
similar between fentanyl and mivacurium, while both prolonged apnoea. Fentanyl
and mivacurium are equally effective in facilitating insertion of the laryngeal
mask airway following anaesthetic induction with propofol.
PMID- 10781115
TI - Postoperative pain control following remifentanil-based anaesthesia for major
abdominal surgery.
AB - Eighty patients undergoing major abdominal surgery using remifentanil-based
anaesthesia were randomly allocated in a double-blind manner to receive an
intravenous bolus of fentanyl, buprenorphine, morphine or piritramide 20 min
before the end of surgery. A reduced dose was administered postoperatively when
patients reported moderate pain. Subsequent analgesia was provided by patient
controlled analgesia (PCA). The mean time from the end of anaesthesia to
spontaneous respiration was 9 +/- 5 min. At first pain assessment, 63% of
patients reported no or mild pain; 80% of patients required the second opioid
bolus, those receiving piritramide needed the bolus significantly later than
patients receiving buprenorphine or fentanyl. First PCA requirement also occurred
significantly later in the piritramide group. This technique provided effective
postoperative pain relief and transition to routine PCA and did not compromise
recovery.
PMID- 10781117
TI - A prospective randomised controlled study of patient-controlled propofol sedation
in phobic dental patients.
AB - The safety and effectiveness of patient-controlled propofol sedation was
prospectively assessed in 18 healthy, phobic dental patients. Using a randomised,
crossover design each patient received two sessions of equivalent dental
treatment under patient-controlled or clinician-controlled propofol sedation. The
patient-controlled technique used 29.8% less drug (time-weighted dose) than the
clinician-controlled method (p = 0.011). There was a high correlation between
number of demands and number of doses actually infused during the patient
controlled technique (r = 0.99, p < 0. 001). Clinically, the level of sedation
was lighter and the degree of operator satisfaction was higher with patient
controlled sedation. Blood pressure and arterial oxygen saturation showed minimal
changes and remained within normal ranges during both techniques. Patient
controlled sedation produced a greater reduction in dental and general anxiety
compared with clinician-controlled sedation, but the difference did not reach
statistical significance. Three times the number of patients expressed a
preference for the patient-controlled, compared with the clinician-controlled,
technique. Patient-controlled sedation provides safe and acceptable intra
operative anxiolysis for phobic dental patients, but with reduced propofol
dosage.
PMID- 10781118
TI - Use of diclofenac in children with asthma.
AB - This study investigated the effect of diclofenac on the lung function of 70
children aged 6-15 years with a diagnosis of asthma, recruited from a hospital
respiratory clinic. Peak flow and a forced expiratory flow-volume loop were
measured and the patients were then given 1-1.5 mg.kg-1 effervescent diclofenac
orally. Spirometry was repeated at 10, 20 and 30 min, a 15% decrease in results
being considered a significant reduction in lung function. No patient
demonstrated a consistent reduction in lung function of > 15% during the study
and there were no reports of wheezing or increased bronchodilator use after
completion of the spirometry. In conclusion, we studied a group of genuine
asthmatics and found no clinically significant incidence of bronchospasm with the
use of a single therapeutic dose of diclofenac.
PMID- 10781119
TI - Emergence characteristics and postoperative laryngopharyngeal morbidity with the
laryngeal mask airway: a comparison of high versus low initial cuff volume.
AB - In this study we tested the hypothesis that the initial cuff volume of the
laryngeal mask airway influences emergence characteristics and postoperative
laryngopharyngeal morbidity. One hundred and sixty adult patients undergoing
minor surgery were randomly assigned for airway management with the laryngeal
mask airway with either a fully inflated cuff (LMA-High) or a semi-inflated cuff
(LMA-Low). Anaesthesia was with propofol, nitrous oxide, oxygen and isoflurane.
Following insertion, the cuff was inflated with either 15 or 30 ml for the size 4
(females) and 20 or 40 ml for the size 5 (males). At the end of surgery, a
blinded observer documented the presence or absence of adverse airway events
(hypoxia, hypercapnea, coughing, retching, regurgitation/vomiting, airway
obstruction, hypoventilation, hiccupping, biting, body movement or shivering)
during every 1 min epoch and cardiorespiratory variables (heart rate, mean blood
pressure, arterial oxygen saturation, end-tidal carbon dioxide and respiratory
rate) every 5 min until the patient was awake and the laryngeal mask airway
removed. Patients were interviewed about pharyngolaryngeal morbidity (sore
throat, dysphonia and dysphagia) immediately before leaving the postanaesthesia
care unit and 18-24 h following surgery. Analysis by epoch showed more partial
airway obstruction in the LMA-High group, but analysis by patient numbers
revealed no difference. Heart rate was slightly higher in the LMA-High group upon
arrival in the postanaesthesia care unit, but otherwise there were no differences
in cardiorespiratory responses. Sore throat and dysphagia were more common in the
LMA-High group. We conclude that, in general, emergence characteristics with the
laryngeal mask airway are not influenced by the volume of air used to inflate the
cuff, but that postoperative sore throat and dysphagia are more likely at high
initial cuff volumes.
PMID- 10781120
TI - The implications of HIV for the anaesthetist and the intensivist.
AB - The acquired immune deficiency syndrome has reached pandemic proportions.
Anaesthetists should be aware of the implications of dealing with increasing
numbers of both diagnosed and undiagnosed, symptomatic and asymptomatic, human
immunodeficiency virus-infected patients in the fields of intensive therapy,
operating theatre anaesthesia, obstetrics and pain management. With recent
advances, important insights have been gained into the pathogenesis of human
immunodeficiency virus. Molecular techniques allow quantification of viral
burden, and together with CD4 T-lymphocyte count, prognosis and response to
therapy can be evaluated. New drugs and therapeutic regimens have improved
prognosis for those who are infected with the virus and vertical transmission of
infection from mother to infant can be minimised. Should accidental occupational
exposure to the virus occur, a prophylactic regimen of antiretroviral drugs can
be administered in an attempt to prevent subsequent human immunodeficiency virus
infection.
PMID- 10781121
TI - Alteration in flow delivery with antisyphon devices.
AB - The aim of this study was to determine whether infusion sets containing
antisyphon devices increased the time to initial flow from syringe drivers. The
antisyphon devices assessed were those manufactured by B Braun, Wescott and
Vygon. Each device was placed between a 50-ml syringe and a spiral extension set
and primed with saline. A fourth syringe and spiral extension set acted as a
control. The infusion sets were placed in four identical syringe drivers and
started simultaneously. The time from pressing the start button until the initial
flow for each infusion set (start-up time) was recorded. The test was conducted
15 times each at 2 ml.h-1, 10 ml. h-1 and 50 ml.h-1. At 2 ml.h-1 the start-up
time was significantly longer with all the antisyphon sets compared with the
control (p < 0. 0001). At higher infusion rates the differences between the
antisyphon sets and the control were less pronounced. Clinicians who use syringe
driver infusions should be aware of this delay between the activation of the
infusion pump and the onset of flow and take steps to prevent it.
PMID- 10781122
TI - A comparison of the intubating laryngeal mask tracheal tube with a standard
tracheal tube for fibreoptic intubation.
AB - We conducted a prospective randomised study to compare the intubating laryngeal
mask tracheal tube with a standard tube, for ease of tracheal intubation over a
fibrescope. Thirty-six patients were investigated, using a sequential analysis
technique. Ease of intubation was improved when the intubating laryngeal mask
tracheal tube was used compared with the standard tube (p = 0.0009). Median
(interquartile range [range]) intubation times (time from the tube's tip being
level with the patient's teeth to successful placement) were 1.5 (1-2.3 [1-3]) s
when the intubating laryngeal mask tracheal tube was used and 5 (3-7.3 [3-13]) s
when the standard tube was used (p < 0.0001).
PMID- 10781123
TI - Laser surgery in a patient with Romano-Ward (long QT) syndrome and an automatic
implantable cardioverter defibrillator.
AB - A 48-year-old woman with Romano-Ward syndrome (a hereditary long QT syndrome),
asthma and an automatic implantable cardioverter defibrillator presented for
laser surgery for debulking of a massive nasopharyngeal tumour prior to
radiotherapy. Automatic implantable cardioverter defibrillators have only
relatively recently been used to treat patients with the long QT syndrome and are
indicated for the high-risk individual when conventional treatment has failed or
when beta-blockers are contraindicated. If surgery requires the use of surgical
diathermy, a cardiac technician must be present to deactivate the defibrillator
and external pacing electrodes are sited on the chest until the defibrillator can
be reactivated. Radiotherapy requires both deactivation and shielding of the
device.
PMID- 10781124
TI - Upper airway reflex sensitivity following general anaesthesia for day-case
surgery.
AB - We have studied changes in upper airway reflex sensitivity following general
anaesthesia using dilute ammonia vapour as a chemical stimulant in 16 patients
undergoing elective laparoscopic gynaecological surgery. We measured the
threshold concentration of ammonia vapour required to elicit a transient
reduction of inspiratory flow caused by glottic closure, defined as a glottic
stop. Measurements of upper airway reflex sensitivity and auditory reaction time
were obtained before surgery, and at 60 and 120 min after recovery. Auditory
reaction time was depressed significantly at 60 min but was similar to baseline
values 120 min after recovery. Upper airway reflex sensitivity remained
significantly reduced at 60 and 120 min despite the return of auditory reaction
time to normal. The lack of correlation between upper airway reflex sensitivity
and auditory reaction time suggests that central nervous system depression alone
does not explain the delayed recovery in airway reactivity.
PMID- 10781125
TI - The efficacy of surgically placed epidural catheters for analgesia after
posterior spinal surgery.
AB - Posterior spinal fusion for correction of scoliosis is a major procedure for
which the provision of satisfactory, safe postoperative analgesia is often a
problem. One possible solution involves the placement of epidural catheters under
direct vision by the surgeon at the end of the procedure, followed by an epidural
infusion of local anaesthetic with or without an opioid. Despite its simplicity,
this technique has not been reported as being consistently successful. We report
an observational study of the analgesia achieved with surgically placed epidural
catheters and of the reasons for the failure of the technique. Fourteen
consecutive patients undergoing posterior spinal fusion had epidural catheters
placed by the surgeon and had radio-opaque dye injected down the catheter 15 min
before their routine postoperative chest X-ray. Analgesia was assessed at 0, 6,
12 and 24 h after surgery using visual analogue scores. Five patients had
inadequate pain control; none of these patients had dye visible in the epidural
space. Seven patients had dye visible in the epidural space; all of these cases
had satisfactory analgesia. In two cases, dye was observed in the paravertebral
gutters; both of these patients had satisfactory postoperative analgesia. This
small pilot study suggests that correctly placed 'surgical' epidural catheters
are capable of providing good analgesia after posterior spinal fusion and that
misplaced catheters, seen in a large proportion of patients, are associated with
inadequate analgesia.
PMID- 10781126
TI - An independent assessment of a supraregional pain management programme and
comparison of patients' and general practitioners' perceptions of the effects.
AB - This study was designed to evaluate the therapeutic response, as perceived by
patients and their general practitioners, to a supraregional residential pain
management programme (INPUT). Twenty patients who completed the INPUT programme
and their general practitioners, were sent locally designed questionnaires.
Eighteen patients and 16 general practitioners responded. Patients were assessed
for the effects of the programme on a wide variety of treatment targets
reflecting quality of life. General practitioners were questioned about changes
in dependence upon healthcare services. The mean time from attending INPUT to
assessment was 11.4 (5.7) months. Thirteen patients indicated a moderate or
maximal improvement in quality of life. General practitioners reported a reduced
use of healthcare services and improvement in quality of life. The majority of
our patients attending INPUT gained benefits that improved their quality of life.
Healthcare services appeared to benefit from the patients' greater independence
in managing their symptoms.
PMID- 10781127
TI - Intra-ocular pressure and haemodynamic changes after tracheal intubation and
extubation: a comparative study in glaucomatous and nonglaucomatous children.
AB - This prospective, controlled study was conducted to compare the effects of
tracheal intubation and extubation on intra-ocular pressure changes and
haemodynamic parameters in paediatric patients with and without glaucoma. The
children were scheduled for intra-ocular surgery. Twenty children with normal
intra-ocular pressure and 15 with glaucoma were studied. A standardised general
anaesthetic was administered to both groups. After 5 min of anaesthesia, intra
ocular pressure, heart rate and noninvasive blood pressure were measured. These
measurements were repeated 30 s and 2 min after tracheal intubation. Further
measurements were taken before, and 30 s and 2 min after extubation. The increase
in intra-ocular pressure after intubation was greater in the glaucomatous group
than in the normal group. The increase in intra-ocular pressure was greater after
extubation than intubation in both groups, but was similar in the two groups.
However, because of the already increased intra-ocular pressure in glaucomatous
children, they may be at an increased risk of visual damage after intubation and
extubation.
PMID- 10781128
TI - The relationship between change in blood pressure, blood pressure and time.
AB - Physiological homeostatic mechanisms and interventions by anaesthetists attempt
to moderate excessive change in many biological variables during anaesthesia.
These mechanisms may have fast or slow response times. This study describes how
mean arterial blood pressure changes with time and how the change is dependent
upon the pre-existing blood pressure. The results demonstrate the 'regression
towards the mean' concept; low arterial blood pressures increase and high
pressures decrease. The data are the result of all interactions and have been
used to produce an 'envelope' into which 80% of all changes fall. Alarm systems
using this envelope could warn of excessive changes that occur within short time
intervals.
PMID- 10781129
TI - Visible and occult blood contamination of laryngeal mask airways and tracheal
tubes used in adult anaesthesia.
AB - The purpose of this study was to compare visible and occult blood contamination
of 50 laryngeal mask airways and 50 tracheal tubes following routine anaesthesia
for procedures not involving the oropharyngeal or nasal cavities. All airway
devices were examined visually for the presence of blood before washing in 100 ml
of water. A semiquantitative dipstick was used to test for the presence of blood
in the washings. Laryngeal mask airways were examined visually by both authors to
test agreement. The results show that occult blood contamination occurred in 78%
of tracheal tubes and 76% of laryngeal mask airways, while visible blood
contamination was 16% and 12%, respectively. Other studies reporting visible
blood contamination of airway devices probably underestimate the true incidence
of blood contamination. Oral secretions following the use of these devices should
be considered as high risk for transmission of blood-born viruses. Anaesthetic
and recovery staff should be protected against the risks of occupational exposure
to oral secretions following the use of airway devices.
PMID- 10781130
TI - The role of anaesthetists as peri-operative physicians.
PMID- 10781131
TI - Early detection of patients at risk (PART)
PMID- 10781132
TI - Temporary occlusion of a persistent tracheocutaneous fistula during anaesthesia.
PMID- 10781133
TI - Upper airway obstruction secondary to a lingual tonsil.
PMID- 10781134
TI - Percutaneous dilational trachestomy in the morbidly obese.
PMID- 10781135
TI - A novel approach to inspiratory vocal cord dysfunction.
PMID- 10781136
TI - The role of the Combitube in airway management.
PMID- 10781137
TI - The tracheal tube 'pull-back' test.
PMID- 10781138
TI - Right- or left-handed laryngoscopy?
PMID- 10781139
TI - Delayed extubation facilitated with the use of a laryngeal mask airway (LMA) on
the intensive care unit (ICU)
PMID- 10781140
TI - Posture and ventilator associated pneumonia.
PMID- 10781142
TI - Haemodynamic instability with iodinated contrast agents.
PMID- 10781143
TI - Hyperkalaemia and rapid blood transfusion.
PMID- 10781144
TI - Use of a pleurogram to identify the position of a misplaced subclavian catheter.
PMID- 10781145
TI - Accidental intraperitoneal insertion of femoral haemodialysis catheter in tense
ascites and anasarca.
PMID- 10781146
TI - Control of tracheal cuff pressure.
PMID- 10781149
TI - Anaesthetic machines vs. draw-over apparatus.
PMID- 10781150
TI - Emergency drugs.
PMID- 10781151
TI - FW-537-1 fluid warmer.
PMID- 10781153
TI - Presentation of 0.167% bupivacaine in 500-ml bags.
PMID- 10781155
TI - Poor interlock safety with datum sevoflurane vaporisers.
PMID- 10781157
TI - Simple apparatus for continuous nebulisation of prostacyclin.
PMID- 10781158
TI - Anaesthetic preassessment clinics.
PMID- 10781159
TI - Inadequate training? Perhaps not!
PMID- 10781160
TI - Caesarean section in a patient with Engelmann's disease.
PMID- 10781162
TI - Clinical efficacy of anti-emetics following surgery.
PMID- 10781164
TI - Cerebrospinal fluid filtration for treating Guillain-Barre syndrome: is there any
pathological background?
PMID- 10781165
TI - Remifentanil infusions for cardiac and vascular anaesthesia.
PMID- 10781166
TI - Faking unconsciousness.
PMID- 10781167
TI - Pain relief post craniotomy: a balanced approach?
PMID- 10781168
TI - Pain relief in children after neurosurgery.
PMID- 10781169
TI - The 'Sevophone' for induction of children.
PMID- 10781170
TI - New method for assessing sensory blockade.
PMID- 10781171
TI - Avoiding air emboli during pressure infusion.
PMID- 10781172
TI - More painful spikes.
PMID- 10781173
TI - Syringe labels using an empty drug ampoule.
PMID- 10781174
TI - Dystrophia myotonica.
PMID- 10781175
TI - Hypoxia caused by body piercing.
PMID- 10781176
TI - Nip - ple.
PMID- 10781177
TI - Wonderful wonderful Copenhagen?
PMID- 10781178
TI - Facts and future lines of research in lower urinary tract symptoms in men and
women: an overview of the role of alpha1-adrenoreceptor antagonists.
PMID- 10781179
TI - alpha1-adrenergic receptors in the lower urinary tract and vascular bed:
potential role for the alpha1d subtype in filling symptoms and effects of ageing
on vascular expression.
PMID- 10781180
TI - Mode of action of alpha1-adrenoreceptor antagonists in the treatment of lower
urinary tract symptoms.
PMID- 10781181
TI - A detailed description, by age, of lower urinary tract symptoms in a group of
community-dwelling women.
PMID- 10781183
TI - New developments in the pharmacological management of prostate cancer.
PMID- 10781182
TI - Current view and status of the treatment of lower urinary tract symptoms and
neurogenic lower urinary tract dysfunction.
PMID- 10781184
TI - Target sites for manipulating apoptosis in prostate cancer.
PMID- 10781185
TI - The role of endothelin-1 and endothelin receptor antagonists in prostate cancer.
PMID- 10781187
TI - The world federation of hemophilia
PMID- 10781186
TI - Facts and future lines of research in prostate cancer: concluding remarks.
PMID- 10781188
TI - Hemophilia 2000 in Montreal; bringing the global haemophilia community together
PMID- 10781189
TI - Controlling acute bleeding episodes with recombinant factor VIIa in haemophiliacs
with inhibitor: continuous infusion and bolus injection.
AB - The efficacy of recombinant activated factor VII (rFVIIa, NovoSeven) in five
Haemophiliacs (four Haemophilia A, one Haemophilia B), with high inhibitors
ranging from 70 to 1900 Bethesda units, was evaluated. The treatment regimen was
divided into two groups: group I, continuous infusion of 16.5 microg h-1 kg-1
body weight (bw) after the initial bolus of 90 microg kg-1 bw in three episodes
of severe bleeding and group II, bolus injection 80-150 microg kg-1 bw every 3
hours for a maximum of four doses in six haemarthroses. The bleeding was
effectively controlled within 1 to 48 h in five of nine bleeding episodes. One
patient in group I, who had active arterial bleeding requiring sutures, had an
ineffective response and three patients in group II had partially effective
responses because the rFVIIa was given after the onset of bleeding at 36, 44 and
72 h, respectively. The prothrombin time was shortened and the FVII:C levels were
successfully achieved at approximately 10 U mL-1. The continuous infusion reduced
the total dose of rFVIIa by 50%. Recurrent bleeding episodes were found in three
patients; two occurred at the same site after ceasing rFVIIa for 51 h and while
receiving rFVIIa at 144 h and one occurred at a new site after ceasing rFVIIa for
12 h. Our experience would suggest that rFVIIa is effective in controlling acute
bleeding episodes in Haemophiliacs with high inhibitors either by continuous
infusion or bolus injection.
PMID- 10781190
TI - The use of central venous catheters (portacaths) in children with haemophilia.
AB - The experience with central venous implantable devices (portacaths) has been
reviewed in children attending the Auckland Hospital Haemophilia Centre. Fourteen
children had 23 portacaths inserted. Thirteen had severe Haemophilia A, of whom
five had high responding inhibitors to factor VIII. All the children were HIV
negative. Ages ranged from 4 months to 13 years at the time of initial placement
and 12 were under 5 years. Indications for portacath placement included primary
and secondary prophylaxis, induction of immune tolerance, prophylactic therapy
post intracranial haemorrhage and poor venous access. Catheter-related infections
occurred in 48% of cases. Staphylococcal species were the most common organisms
isolated followed by gram-negative bacilli. 63% of the infections were
successfully cleared with antibiotics. Haematoma formation occurred in 17% of
catheters, primarily in patients who had high factor VIII inhibitor levels.
Mechanical problems including blockage, leakage and extrusion of the portacath
occurred less frequently (13%). The significant rate of infection in this
immunocompetent population is consistent with other reports. Despite the obvious
benefits of portacaths this complication is potentially serious and causes
appreciable morbidity. In contrast, bleeding complication rates were relatively
low.
PMID- 10781191
TI - Optimising local therapy during oral surgery in patients with von Willebrand
disease: effective results from a retrospective analysis of 63 cases.
AB - Bleeding after dental extractions is very frequent in patients with von
Willebrand disease (vWD) and in the past often necessitated transfusions with
factor VIII/von Willebrand factor concentrates (vWFc). To evaluate the benefits
of a standard local therapy on bleeding complications during oral surgery, 63
consecutive patients with vWD were analysed retrospectively. All types of vWD
were included: type 1 (n=31), type 2 (n=22) and type 3 (n=10). All the patients
had dental extractions or periodontal surgery at the same hospital by the same
oral surgeons. All cases had been given tranexamic acid (TA) before and for 7
days after surgery. As additional local therapy fibrin glue (FG) was used during
surgery in several patients. Additional systemic therapies were: desmopressin
(DDAVP, 0.3 microg kg-1) and fVIII/vWF concentrates (vWFc, 40 U kg-1) given as a
single dose before surgery. The 29 subjects (46%) treated locally did not bleed.
Among the remaining cases, 24 (38%) were given DDAVP as additional systemic
therapy and 6 (9.5%) received vWFc. There was bleeding after surgery in only two
cases who had been given local FG (type 2 B) or systemic vWFc (type 3), but
bleeding was stopped with an additional local application of FG. Our data suggest
that a standard local therapy with TA and FG with DDAVP can prevent bleeding
complications during oral surgery in the majority of patients (84%) with vWD and
reduce the need for concentrates, with all their possible complications and high
costs.
PMID- 10781193
TI - Cardiac surgery and catheterization in patients with haemophilia.
AB - The present study summarizes the results of 12 cardiac surgical procedures
performed in a carrier of Haemophilia B and in six patients with Haemophilia A at
a single centre from 1979 to 1998. The median age of the patients at the time of
intervention was 56 years ranging from 18 years to 73 years. The six patients
with Haemophilia A ranged in severity from moderately to mildly affected. Three
patients were hepatitis C antibody positive. No patients were HIV antibody or
hepatitis B surface antigen positive. The cardiac procedures included cardiac
catheterization (n=4), coronary artery bypass surgery (n=2), percutaneous
transluminal coronary angioplasty (n=1), cardiac valve replacement (AVR n=1 and
AVR/MVR n=2), and closure of an atrial septal defect and subsequent drainage of a
pericardial effusion (n=1). No patients had demonstrable inhibitors at the time
of surgery. Haemostasis was achieved with AHF in 10/11 procedures and high purity
factor IX (Immunine) in one procedure. The initial procedures involved
intermittent bolus factor therapy while more recently, AHF was administered by
continuous intravenous infusion. All patients demonstrated excellent intra- and
post-operative haemostasis. These results, although from a small and varied group
of patients, demonstrate that cardiac surgical procedures can be performed safely
in patients with Haemophilia.
PMID- 10781192
TI - Acquired haemophilia - a study of ten cases.
AB - Clinico-haematological features in 10 patients with acquired Haemophilia are
presented. Three patients had FVIII inhibitors following pregnancy while in six
the cause for development of inhibitors could not be determined. One patient had
acquired von Willebrand's disease. Lupus anticoagulant coexisted with Factor VIII
inhibitors in three patients. All patients presented with sudden onset of
bleeding without any past or family history of a bleeding disorder. Factor VIII
inhibitor levels ranged from 8 to 512 Bethesda units in the nine patients.
Immunosuppressive therapy was given to 8 patients, consisting of CVP regimen or
corticosteroids with endoxan or cyclosporin. Seven patients had clinical and
laboratory responses and one patient did not respond. One patient had severe
postpartum bleeding with acute shock which was controlled with FEIBA. Diagnosis
and management of idiopathic acquired Haemophilia, thus, continues to be a major
challenge, and among acquired Haemophilia, postpartum Haemophilia has good
prognosis.
PMID- 10781194
TI - Loss of factor VIII activity during storage in PVC containers due to adsorption.
AB - Recombinant factor VIII concentrates are stable when administered in a
reconstituted form according to the manufacturer's specifications, and undiluted
via infusion with syringe mini-pumps. However many Haemophilia centres administer
recombinant factor VIII further diluted in intravenous fluids for greater ease of
administration. To investigate the stability of recombinant factor VIII during
administration as a diluted infusion, reconstituted factor VIII was stored in
polyvinylchloride (PVC) mini-bags undiluted (146 IU mL-1) and at factor VIII
concentrations of 10 IU mL-1 and 2 IU mL-1. After 48 h of storage at room
temperature in PVC mini-bags, the recoveries of factor VIII activity were 41.9%
of the initial activity for the undiluted (146 IU mL-1) product and 43.7% of the
initial activity for factor VIII diluted to 10 IU mL-1. For factor VIII diluted
to 2 IU mL-1, the amount of factor VIII activity remaining at 48 h was only 1.8%
of the initial activity. In contrast, 100% of factor VIII activity was recovered
after 48 h when undiluted reconstituted product (146 IU mL-1) was stored in a
syringe. To investigate the mechanism of factor VIII activity loss during
storage, factor VIII samples collected after 0, 3 and 48 h of storage were
analysed by immunoblotting with factor VIII antibodies. No evidence of factor
VIII proteolytic degradation during storage was found, however, large amounts of
factor VIII antigen were recovered from the empty PVC mini-bags following elution
with denaturing detergent. We conclude that clinically significant losses of
factor VIII activity occur during storage in PVC mini-bags and that the loss of
activity is most likely due to protein adsorption onto the plastic surface. This
loss of factor VIII activity during storage in PVC containers may substantially
affect the safety and potential cost savings of administering recombinant factor
VIII by continuous infusion.
PMID- 10781195
TI - Prevalence of human parvovirus B19 and TT virus in a group of young haemophiliacs
in South Africa.
AB - A well recognized hazard of transfusion with blood or blood products is the
acquisition of a viral infection. Parvovirus B19 and transfusion transmitted
virus (TTV) are two of several non-enveloped viruses that may on rare occasions
be present in coagulation factor concentrates. The prevalence of these viruses in
the South African Haemophilia population has not previously been studied. Thirty
nine Haemophiliac children were investigated for evidence of parvovirus and TTV
infection. 26 boys with Haemophilia A had been treated with cryoprecipitate or
intermediate purity factor VIII, and 13 boys with Haemophilia B had received
prothrombin complex concentrates. All the plasma products were prepared from
South African donors and were virally inactivated by heat or solvent/detergent
since 1992. A control group of 32 children who had not been transfused were also
studied. IgG antibodies to B19 were present in 29 of the 39 patients (74%), 18/26
(69%) with Haemophilia A and 12 of the 13 (85%) with Haemophilia B. None of the
patients was IgM antibody positive but two children were PCR positive for B19
DNA. Of the control children, 47% had IgG antibodies to B19, but none were IgM
antibody or B19 DNA positive. TTV viral DNA was found in 10.2% of patients and in
9% of the control group. The results indicate that our locally produced plasma
products are not a significant source of TTV transmitted infection but may
contribute to infection by B19 parvovirus.
PMID- 10781196
TI - Safety and immunogenicity of subcutaneous hepatitis A vaccine in children with
haemophilia.
AB - Individuals with Haemophilia are at risk from hepatitis A virus (HAV) infection
through exposure to blood products. Havrix(R), an intramuscular hepatitis A
vaccine, is currently recommended for the prevention of disease caused by
hepatitis A virus. Because bleeding may complicate intramuscular injections in
those with bleeding disorders, we conducted a randomized, Phase IV clinical trial
to compare the safety and immunogenicity of Havrix(R) given by the subcutaneous
(s.c) vs. intramuscular (i.m.) route. A total of 45 children with Haemophilia
were vaccinated subcutaneously, while their 41 nonhaemophlic siblings were
vaccinated intramuscularly, at a dose of 720 Elisa units (EL.U.) at time 0 and 6
months. All children were anti-HAV and anti-HIV negative at baseline, and the
haemophilic group did not differ from their siblings in alanine aminotransferase
(ALT; 25 IU L-1 vs. 22 IU L-1), or in age; 8.5 years vs. 8.7 years. The vaccine
was well tolerated, with minor adverse events being similar between groups; 21
(47%) vs. 24 (58%), P > 0.05. Local symptoms included soreness in 39 (45%),
erythema in 25 (29%), swelling in 21 (24%), and bruising in six (7%), with no
differences between groups. The proportion seroconverting to anti-HAV IgG
positive did not differ between groups; 98% vs. 97% at month 1; 82% vs. 93% at
month 6; and 100% vs. 100% at month 8, respectively. The HAV geometric mean titre
was lower in those with Haemophilia, 185 vs. 233 mIU mL-1 at month 1; 68 vs. 94
mIU mL-1 at month 6; and 584 vs. 1082 mIU mL-1 at month 8, respectively. We
conclude that Havrix(R) is safe and immunogenic when administered s. c. in
children with Haemophilia.
PMID- 10781197
TI - Orthopaedic outcome of total knee replacement in haemophilia A.
AB - A consecutive series of 16 patients with classical Haemophilia underwent 21 total
knee replacements between 1989 and 1997 for haemophilic arthropathy. The patients
received Factor VIII replacement therapy via continuous infusion, and fibrin glue
was used to facilitate haemostasis. Three different types of prostheses were
used. A follow-up evaluation was undertaken between 2 and 10 years after the
operation (mean 5.6 years) and two patients with infection were excluded. Knee
scores averaged 77.5 (pre-operative 24. 1) and functional scores averaged 84.4
(preoperative 23.2). There were no cases with aseptic loosening of the
prosthesis. Complications included one early deep infection controlled by
conversion of the TKR into an arthrodesis, one case of late septic loosening that
had to be re-operated upon, one case of patellar dislocation, two cases of stiff
knee (fibro-arthrosis) that required manipulation under anaesthesia, one
postoperative hepatitis, one superficial infection treated by incision and
drainage and four febrile patients with no clear source of infection, who
responded to antibiotics alone. In conclusion, TKR offers haemophilic patients a
long-lasting improvement of their quality of life and we therefore advocate its
use with the appropriate indications.
PMID- 10781198
TI - Bell's palsy during interferon therapy for chronic hepatitis C infection in
patients with haemorrhagic disorders.
AB - Two adult patients with life-long severe haemorrhagic disorders commenced on
interferon-alpha2b therapy for chronic hepatitis C infection. Both developed
Bell's palsy several weeks after commencing therapy, They were started on
steroids and, in addition, the first patient discontinued interferon-alpha2b
therapy while the second patient elected to continue with therapy. In both cases
facial paralysis improved over the ensuing weeks. Bell's palsy is often
idiopathic but has been reported. in association with herpesviruses. It is not a
recognised complication of chronic hepatitis B or C infection, or interferon
alpha2b therapy. However, the interferons are associated with numerous adverse
reactions including various neuropsychiatric manifestations and neurological
syndromes. There are several reports of nerve palsies, including optic tract
neuropathy, occurring during interferon therapy, and immune-based mechanisms are
thought to play a role in the aetiopathogenesis. No reports of Bell's palsy in
association with interferon therapy were identified in our literature search,
although one possible case has been reported to the Committee of Safety in
Medicine. Although Bell's palsy in our patients may have occurred by chance, a
neuropathic effect of interferon-alpha2b on the facial nerve cannot be excluded
and we urge physicians using interferons to be aware of this potential side
effect.
PMID- 10781199
TI - High responding factor VIII inhibitors in mild haemophilia - is there a link with
recent changes in clinical practice?
AB - The development of high responding inhibitors is an increasingly recognized
complication of mild Haemophilia. Inhibitors tend to develop in adolescence and
adulthood and this is frequently preceded by high-intensity factor replacement
therapy. We report two patients with mild Haemophilia who developed high
responding inhibitors after continuous infusion with recombinant factor VIII
(Kogenate) as prophylaxis for surgery. We discuss whether recent changes in
clinical practice could be responsible for the apparent increase in high
responding inhibitors in mild Haemophilia.
PMID- 10781201
TI - Pitfalls in the management of a child with mild haemophilia A and a traumatic
hyphaema.
AB - A 12-year-old boy presented with a traumatic hyphaema that failed to settle with
the standard treatment. Subsequent investigation showed that despite a normal
APTT, he had a low factor VIII:C. Treatment with DDAVP precipitated further
bleeding despite correction of the fVIII:C to normal, possibly caused by the
vasodilation induced by the therapy. Bleeding was effectively treated with
recombinant fVIII concentrate. DDAVP may be contraindicated in mild Haemophilia
and von Willebrand patients for treatment of traumatic hyphaema.
PMID- 10781200
TI - HAART and Mycobacterium avium complex in an HIV infected patient with severe
factor VII deficiency.
AB - A clinical syndrome represented by the association of Mycobacterium avium complex
(MAC) infection with initiation of highly active antiretroviral therapy (HAART)
has been recently described in patients with advanced HIV disease. HAART
associated improvement of the immune status might convert a clinically silent MAC
infection into an active mycobacterial disease. A 40-year-old man with severe
factor VII deficiency, advanced HIV-1 disease, a CD4 + lymphocyte count of 15
cells microL-1 (CDC stage A3) and 470,000 HIV-RNA copies mL-1 (measurement by
NASBA system) underwent standard HAART (lamivudine, stavudine and ritonavir). Two
weeks after HAART onset, the patient developed enlargement of the lymph nodes
throughout the mesentery and after seven weeks a rapidly enlarging mass on the
left side of the neck. Culture from a needle aspirate specimen revealed MAC. His
CD4 + count had increased to 97 cells microL-1 and viraemia dropped to
undetectable HIV-RNA copies. While continuing antiviral therapy, multidrug
therapy for MAC infection (clarithromycin, ciprofloxacin, ethambutol, amikacin)
was started with progressive improvement and cure of the neck mycobacterial
infection and disappearance of the abdominal lymph nodes. HAART has been shown to
offer significant clinical and laboratory benefits in terms of HIV disease with
limited side-effects in Haemophiliacs. However, the clinical manifestation of an
opportunistic infection should be mentioned as a possible complication of HAART
in these patients, as well as in other categories of HIV infected patients, and
in patients with congenital coagulopathies.
PMID- 10781202
TI - High titre inhibitor after continuous factor VIII administration for surgery in a
young infant.
PMID- 10781203
TI - Images of absolute retardance L.Deltan, using the rotating polariser method
AB - Modulation techniques for measuring changes in optical birefringence, such as the
rotating-polariser method (Wood & Glazer, 1980, J. Appl. Crystallogr. 13, 217),
allow one to determine |sin delta|, delta = 2piLDeltan/lambda, Deltan = double
refraction, L = light path and lambda = wavelength. However, they generally
suffer from not providing absolute values of the optical retardance or are
limited to relatively low retardance values. In addition, knowledge of the
absolute phase is required when establishing the correct values of optical
orientation information. In this paper, it is shown how the phase delta, and thus
optical retardance, can be extracted from combining measurements of |sin delta|
at different wavelengths. The new approach works on each single point of a 2-D
picture without the need to correlate with neighbouring points. There is
virtually no limit to the retardance, and the computational efforts are small
compared with other methods (e.g. Ajovalasit et al. 1998, J. Strain Analysis 33,
75). When used with imaging techniques, such as the rotating polariser method of
Glazer, Lewis & Kaminsky 1996 (Proc. R. Soc. London Series A452, 2751) this
process has the potential to identify automatically optically anisotropic
substances under the microscope. The algorithm derived in this paper is valid not
only for birefringence studies, but can be applied to all studies of interfering
light waves.
PMID- 10781204
TI - Bituminous emulsions and their characterization by atomic force microscopy
AB - We present a new method for observing oil-in-water emulsions with a continuous
water phase and a dispersed bitumen phase. The fine polydispersed bitumen
micelles were adsorbed to an atomically smooth mica substrate and imaged in
solution by atomic force microscopy in a liquid cell. The height of the adsorbed
bitumen sheet in wet and dry states can be measured and the homogeneity of film
formation by coalescence can be determined. Localization of surfactant onto and
between bitumen micelles is also visualized.
PMID- 10781205
TI - The spatial distribution and resolution of coaxial backscattered electrons in
SEM, calculated by monte carlo simulations
AB - We simulate, within a sample, the trajectories of the backscattered electrons
detected in a scanning electron microscopy with a particular detection geometry.
Thus we obtain the depth and lateral distributions, according to the adjustable
parameter values, of the detected electrons. Finally, the scanline profile across
a chemical edge is drawn. The conditions corresponding to the best lateral
resolution are established; we obtain an ultimate resolution of the same order as
the beam diameter.
PMID- 10781206
TI - The reliability of cryoSEM for the observation and quantification of xylem
embolisms and quantitative analysis of xylem sap in situ.
AB - The reliability of cryoSEM for visualizing gas embolisms in xylem vessels of
intact, functioning roots is examined and discussed. The possibility that these
embolisms form as a result of freezing water columns under tension is discounted
by a double-freeze experiment. Two regions of the same root, one frozen under
tension, the other isolated from the tension by the first freeze, had the same
percentage of embolisms, as did also long pieces of root frozen simultaneously
along their length. The reliability of energy-dispersive X-ray analysis to
measure xylem sap concentration in situ in frozen tissue was established by
measurement of KCl standard solution frozen on stubs, and within xylem vessels.
Solute heterogeneity within the vessels varied with freezing procedure; deep
freeze > LN2 > cryopliers > liquid ethane, but only the deep-freeze method gave
unsatisfactory estimates of concentration for the standard solution. It is
concluded that cryoanalytical SEM is useful for direct observation of gas and
liquid-filled compartments, and for solute analyses at depth within intact plant
organs.
PMID- 10781207
TI - Tracking differential interference contrast diffraction line images with
nanometre sensitivity.
AB - This paper presents a computer vision framework for detecting and tracking
diffraction images of linear structures in differential interference contrast
(DIC) microscopy. The tracker can resolve image displacements of 1/10 of a pixel
despite the weak and orientation-dependent contrast in DIC, as well as the
variable blur in such image data caused by vertical specimen movement. In our
high numerical aperture, high magnification microscope set-up, this resolution
corresponds to 5 nm in object space. In video DIC similar resolution has been
reported hitherto only for rotationally symmetric targets such as bead images.
The tracker was developed for measuring deflections of clamped microtubules with
a freely moving second end. By analysing the thermal fluctuations of such
microtubules it was possible to derive their elasticity. The paper describes a
filtering scheme for the detection and localization of DIC diffraction line
images which represent loci of microtubules. For tracking the movements of the
extracted lines we adopted the sum of squared (brightness) differences algorithm
from computer vision. The analysis of the fluctuation measurements demonstrates
the high sensitivity of this tracking technique in quantifying positional and
orientational changes. We derived that the theoretical limit in tracking
displacements of such diffraction line images is 1.25 nm, four times below the
experimentally verified sensitivity. This indicates that the proposed tracker is
still suboptimal. Nevertheless, the tracking precision was sufficient to reveal
subtle deviations in the distribution of microtubule deflection from free
diffusion. They were induced by pivotal points and multiple positions of
relaxation. Also, the results suggest that there were defects in the polymer
structure which caused very small but significant bends in the microtubule axis.
PMID- 10781208
TI - An integral-geometric approach for the euler-Poincare characteristic of spatial
images
AB - The determination of the Euler-Poincare characteristic of a set can be based on
observations of a digitized image of that set. In the present paper the
correctness of the method is proved due to a strict integral-geometric approach.
Our result also provides a link to the methods which are used in image analysis
and are based on graph theory.
PMID- 10781209
TI - The influence of the regularization parameter and the first estimate on the
performance of tikhonov regularized non-linear image restoration algorithms
AB - This paper reports studies on the influence of the regularization parameter and
the first estimate on the performance of iterative image restoration algorithms.
We discuss regularization parameter estimation methods that have been developed
for the linear Tikhonov-Miller filter to restore images distorted by additive
Gaussian noise. We have performed experiments on synthetic data to show that
these methods can be used to determine the regularization parameter of non-linear
iterative image restoration algorithms, which we use to restore images
contaminated by Poisson noise. We conclude that the generalized cross-validation
method is an efficient method to determine a value of the regularization
parameter close to the optimal value. We have also derived a method to estimate
the regularization parameter of a Tikhonov regularized version of the Richardson
Lucy algorithm. These iterative image restoration algorithms need a first
estimate to start their iteration. An obvious and frequently used choice for the
first estimate is the acquired image. However, the restoration algorithm could be
sensitive to the noise present in this image, which may hamper the convergence of
the algorithm. We have therefore compared various choices of first estimates and
tested the convergence of various iterative restoration algorithms. We found that
most algorithms converged for most choices, but that smoothed first estimates
resulted in a faster convergence.
PMID- 10781210
TI - Third joint meeting of the European Tissue Repair Society and Wound Healing
Society: an opportunity to develop worldwide wound healing strategies.
PMID- 10781211
TI - A bilayered living skin construct (APLIGRAF) accelerates complete closure of hard
to-heal venous ulcers.
AB - The efficacy of a bilayered, living skin construct (APLIGRAF(R) [Graftskin]) was
evaluated in patients (n = 120) with hard- to-heal venous leg ulcers of greater
than 1 year's duration. The study was prospective, randomized, and controlled.
Patients received Graftskin plus compression therapy, or standard compression
therapy (active control). Patients were evaluated for frequency and time to
complete (100%) wound closure. Treatment with Graftskin was significantly more
effective than active control in the percentage of patients healed by 6 months
(47% vs. 19%; p < 0.005) and the median time to complete wound closure (p <
0.005). Analysis with multivariate regression methods, adjusting for factors
generally thought to influence wound healing (duration, baseline area, depth,
location, fibrinous wound bed, and infection), showed that patients treated with
Graftskin were twice as likely to achieve complete wound closure by 6 months (p <
0.005), and over 60% more effective in achieving wound closure than active
control (p < 0.01). These data indicate that Graftskin is an effective treatment
for venous ulcers of greater than 1 year's duration.
PMID- 10781212
TI - Systemic treatment of venous leg ulcers with high doses of pentoxifylline:
efficacy in a randomized, placebo-controlled trial.
AB - Several small studies have indicated that the systemic administration of
pentoxifylline may accelerate healing of venous leg ulcers. The goal of this
study was to further evaluate these findings in a larger scale placebo controlled
trial and to explore the effect of the dose of pentoxifylline on healing. The
study used a prospective, randomized, double-blind, parallel group placebo
controlled design in a multicenter outpatient setting. Patients with one or more
venous ulcer were enrolled, with all patients receiving standardized compression
bandaging for treatment for their ulcers. Patients were also randomized to
receive either pentoxifylline 400 mg, pentoxifylline 800 mg (two 400 mg tablets),
or placebo tablets three times a day for up to 24 weeks. The main outcome measure
was time to complete healing of all leg ulcers, using life table analysis. The
study was completed as planned in 131 patients. Patients receiving 800 mg three
times a day of pentoxifylline healed faster than placebo (p = 0.043, Wilcoxon
test). The median time to complete healing was 100, 83, and 71 days for placebo,
pentoxifylline 400 mg, and pentoxifylline 800 mg three times a day, respectively.
Over half of all patients were ulcer free at week 16 (placebo) and at week 12 in
both pentoxifylline groups. Whereas the placebo group had only achieved complete
healing in half of the cases by week 16, all of the subjects remaining in the
group receiving the high dose of pentoxifylline had healed completely. Treatment
with pentoxifylline was well tolerated with similar drop-out rates in all three
treatment groups. Complete wound closure occurred at least 4 weeks earlier in the
majority of patients treated with pentoxifylline by comparison to placebo. A
higher dose of pentoxifylline (800 mg three times a day) was more effective than
the lower dose. We conclude that pentoxifylline is effective in accelerating
healing of leg ulcers.
PMID- 10781213
TI - A modified culture system for epidermal cells for grafting purposes: an in vitro
and in vivo study.
AB - A fully differentiated epithelium mimicking the features of native epidermis was
obtained in vitro by culturing human or porcine epidermal keratinocytes on
polyester filter substrate at the air-liquid interface. In addition, after 2
weeks of culture, hemidesmosome-like structures were formed along the basal area
of the plasma membrane of the basal cells at the cell-filter interface. When
grafted onto full-thickness skin wounds in pigs, the take of cell sheets detached
from the filter with dispase was significantly higher (about 70%) in comparison
to mechanically detached keratinocytes (about 15%). With dispase-treated
keratinocytes alone, basement membrane formation took place within 7 days
postgrafting as judged from the presence of a lamina lucida and positive staining
for type IV collagen. Also, numerous hemidesmosomes and anchoring fibrils were
observed at the basal cell-"neodermis" interface. The fully differentiated
epidermis, generated by culturing keratinocytes at the air-liquid interface and
detached from the substrate by dispase-treatment, is less fragile and easier to
handle than epidermal autografts obtained by conventional culturing methods.
Detachment by a short dispase-treatment appeared in our hands the only method for
successful and complete epithelial regeneration in full-thickness wounds.
PMID- 10781214
TI - Incubation of cultured skin substitutes in reduced humidity promotes
cornification in vitro and stable engraftment in athymic mice.
AB - Cultured skin substitutes have been used successfully for adjunctive treatment of
excised burns and chronic skin wounds. However, limitations inherent to all
models of cultured skin include deficient barrier function in vitro, and delayed
keratinization after grafting in comparison to native skin autografts.
Experimental conditions for incubation of skin substitutes were tested to
stimulate barrier development before grafting, and measure responses in function
and stability after grafting. Cultured skin substitutes consisted of human
keratinocytes and fibroblasts attached to collagen-glycosaminoglycan biopolymer
substrates. Parallel cultured skin substitutes were incubated at the air-liquid
interface in ambient (48-61%) or saturated (79-91%) relative humidity, and
grafted to athymic mice on culture day 14. Additional cultured skin substitutes
were incubated in the experimental conditions for a total of 28 days. Cadaveric
human skin and acellular biopolymer substrates served as controls. Epidermal
barrier was evaluated as the change in surface hydration by surface electrical
capacitance with the NOVA Dermal Phase Meter. Cultured skin substitutes and
cadaveric skin incubated in ambient humidity had lower baseline surface
electrical capacitance and less change in surface electrical capacitance than
parallel samples incubated in saturated humidity at all time points in vitro.
Data from healing cultured skin substitutes at 2, 4, 8 and 12 weeks after
grafting showed an earlier return to hydration levels comparable to native human
skin, and more stable engraftment for skin substitutes from ambient humidity. The
data indicate that cultured skin substitutes in ambient humidity have lower
surface electrical capacitance and greater stability in vitro, and that they
reform epidermal barrier more rapidly after grafting than cultured skin
substitutes in saturated humidity. These results suggest that restoration of
functional epidermis by cultured skin substitutes is stimulated by incubation in
reduced humidity in vitro.
PMID- 10781215
TI - Assessment of the potential for microbial resistance to topical use of multiple
antimicrobial agents.
AB - The goal of this study was to reduce the likelihood of the generation and/or
persistence of bacterial resistance to some antimicrobial components contained in
a topical antimicrobial mixture (neomycin, polymyxin B, mupirocin and
ciprofloxacin) for use with cultured skin grafts, by substitution of alternative
antimicrobials, specifically fusidic acid for mupirocin and ofloxacin for
ciprofloxacin. The alternative agents failed to serve that purpose. However, with
the exception of specific genera of bacteria, Proteus sp. and Providencia
stuartii, 90% or more of all other bacteria tested were susceptible to the action
of one or more of the individual antimicrobial agents contained in the original
mixture. This was true when bacteria were highly susceptible to the
antimicrobials, generally, or when bacteria resistant to specific antimicrobials
such as penicillin-class antibiotics and ciprofloxacin, were tested. These
results suggest that the redundancy of antimicrobials contained in this mixture
reduces the chance that resistant bacteria generated by the use of this mixture
or already present on wounds would persist when the mixture is used clinically.
PMID- 10781216
TI - Reader response to Carroll's "To be a nurse"
PMID- 10781217
TI - Reader response to Carroll's "To be a nurse"
PMID- 10781218
TI - Deadly secrets.
PMID- 10781219
TI - Intensive challenges down the road: pioneering a pathway to the future.
PMID- 10781220
TI - Screening for domestic violence during pregnancy.
AB - Domestic violence is an international social issue and significant cause of
trauma. Pregnant women are at risk for intentional trauma and pose unique
challenges for care. Patients are often not truthful about the mechanism of
injury and are reluctant to seek care. Prenatal and postpartum care can be
adversely affected if the woman continues in the abusive relationship. A careful
approach to screening all pregnant trauma patients is presented to help
clinicians with assessment for intentional trauma.
PMID- 10781221
TI - The implications of domestic violence for home care providers.
AB - The effects of domestic violence are revealed in shelters for battered women, but
with more emphasis on prevention, cues to violence may first be detected in home
settings. The most common injury sites involve the upper body. Based on a 2-year
record (N = 153) review at a shelter for battered women, prevalence of injuries,
health conditions and substance use were examined. Most women (82%) reported
injuries, and most had past injuries severe enough to require surgery or
hospitalization. This article educates home care providers about the types of
abuse they are likely to find in women from violent homes and their health
implications.
PMID- 10781222
TI - Child passenger safety.
PMID- 10781223
TI - Screening a simple fracture.
PMID- 10781224
TI - Crash testing: using computers to save lives.
PMID- 10781225
TI - Complications related to the use of vascular hemostasis devices.
PMID- 10781226
TI - Intimate partner violence fact sheet.
PMID- 10781228
TI - Another Woman.
PMID- 10781227
TI - Abstracts of the Literature.
PMID- 10781229
TI - Current controversies in diagnosis and management of neonatal seizures.
PMID- 10781230
TI - Polymerase chain reaction in the diagnosis of tuberculosis.
AB - OBJECTIVES: To evaluate efficacy of polymerase chain reaction (PCR), using the
insertion sequence IS6110 as target for DNA, to detect Mycobacterium tuberculosis
in body fluids of children with suspected tuberculosis (TB). SETTING:
Hospitalized patients. METHODS: A comparison of PCR on body fluids, Acid Fast
Bacilli staining (AFB), mycobacterial culture and clinical features, with special
emphasis on central nervous system (CNS) TB was done over 18 month period. A
total of 80 children were evaluated, 41 with probable TB disease and 39 controls.
Cases were defined by specific clinical criteria. Controls included patients free
of clinical TB. PCR was done on the clinical specimens and compared with clinical
findings, radiological features, Mantoux (Mx) testing, AFB staining and culture
on Lowenstein-Jensen (LJ) medium. RESULTS: Sensitivity of PCR in CSF samples was
100%, in gastric aspirate samples was 20% and in pleural fluid samples was 100%.
CONCLUSION: PCR technique may become a valuable diagnostic tool for the diagnosis
of tuberculosis in children especially in CNS TB.
PMID- 10781232
TI - Epidemiology of sickle cell disease in a rural hospital of central India.
AB - OBJECTIVE: To study the epidemiology of sickle cell disease in pediatric age
group in a rural hospital of Central India. DESIGN: Prospective descriptive
hospital based study. SUBJECTS: 99 admitted patients of sickle cell disease were
studied for a period of 1 year. RESULTS: Prevalence of sickle cell disease was
5.7% (99/1753) hospitalizations of which 61.6% (n=61) had homozygous sickle cell
disease (HbSS) whereas 38.4% (n=38) had heterozygous state (HbAS). Of these, 62
(63%) were below five years of age. Male : Female ratio was 1.65:1 in HbSS cases
and 1.71:1 in HbAS cases. History of consanguinity was present in 7 (7%) of which
5 (8.2%) had HbSS and 2 (5.2%) had HbAS. Incidence was maximum in the Mahar
community (70%) followed by Kunbi (8 %) and Teli (6%). Vascular occlusive crisis
(23. 3%) was the commonest crisis encountered followed by hyperhemolytic crisis
(16.3%). There was no correlation between hemoglobin levels and the occurrence of
vascular occlusive crisis. Maximum cases required their first blood transfusion
between second and third year of age. Requirement of blod transfusion was more in
HbSS cases. Four patients died of which three had HbSS and were below five years
of age. Splenic sequestration crisis was the commonest cause of death.
CONCLUSION: Sickle cell disease is prevalent in this area and most cases present
before 5 year of age. VOC is the commonest crisis seen, but death often occurs
due to sequestration crisis and usually below 5 years of age.
PMID- 10781231
TI - Evaluation of the WHO/UNICEF algorithm for integrated management of childhood
illness between the ages of one week to two months.
AB - OBJECTIVE: To evaluate the utility of the WHO/UNICEF algoritham for integrated
management of childhood illness (IMCI) between the ages of 1 week to 2 months.
DESIGN: Prospective observational. SETTING: The Outpatient Department and
Emergency Room of a medical college hospital. METHODS: 129 infants presenting to
Outpatient Department (n=70) or Emergency Room (n=59) were assessed and
classified as per 'IMCI' algorithm and treatment required was identified. A
detailed evaluation with all relevant investigations was also done for these
subjects. The final diagnoses made and therapies instituted on this basis served
as 'gold standard'. The diagnostic and therapeutic agreement between 'gold
standard and the 'IMCI' was computed. RESULTS: More than one illness was present
in 97(75.2%) of subjects as per 'gold standard' (mean 2.1). Subjects having any
referral criteria as per 'IMCI' algorithm had a greater (p=0.002) co-existence of
illnesses (mean 2.3 vs. 1.8 illnesses per child, respectively. IMCI algorithm
covered majority (81-84%) of the recorded diagnoses either partly (40-41%) or
fully (40-44%). The referral criteria proved quite sensitive (86-87%) in
predicting hospitalization but had a lower specificity (53-58%). a total
agreement with IMCI was found in 60-66% cases. The mismatch (34-40%) was more
commonly of overdiagnosis (21-23%) rather than underdiagnosis (15-21%). The
sensitivity of the algorithm to identify serious bacterial infection was high
(96.1-96.5%) while the specificity was relatively low (51. 8-59.7%). Upper
respiratory infection (URI)emerged as an important cause resulting in unnecessary
referrals (13 out of 21 cases). Of the 43 cases identified as diarrhea by the
algorithm, 6 had breast fed stools, which do not require any therapy. The 'IMCI'
algorithm had a provision for preventive services of immunization and
breastfeeding counseling (18% possibility of availing missed opportunities in
both). CONCLUSION: There is a sound scientific basis for adopting IMCI approach
even in young infants as there is a need to improve the specificity of referral
criteria. Two important conditions identified for possible refinement are URI and
breast fed stools
PMID- 10781233
TI - Acute lymphoblastic leukemia: current treatment concepts.
PMID- 10781234
TI - Ashy dermatosis.
PMID- 10781235
TI - Immunogenicity of hepatitis B vaccine incorporated into the expanded program of
immunization schedule.
PMID- 10781236
TI - Natural immunity to Haemophilus influenzae type b among healthy children in
Istanbul, Turkey.
PMID- 10781237
TI - Necrotising enterocolitis following ophthalmological examination in preterm
neonates.
PMID- 10781238
TI - Splenectomy and lieno-renal shunt for extra hepatic portal venous obstruction.
PMID- 10781239
TI - An appraisal of pediatric dermatological emergencies.
PMID- 10781240
TI - Hereditary angioedema 'Type I': report of a family with a fatal case.
PMID- 10781241
TI - Perianal streptococcal dermatitis.
PMID- 10781242
TI - Jansen's metaphyseal chondrodysplasia.
PMID- 10781243
TI - Colonic obstruction in classical malrotation.
PMID- 10781244
TI - Epitheloid sarcoma in a neonate.
PMID- 10781246
TI - Reply
PMID- 10781247
TI - Safeguard against tuberculosis for children in schools.
PMID- 10781245
TI - Influence of age and antitubercular therapy on BCG response.
PMID- 10781248
TI - Reply
PMID- 10781249
TI - Type of syringe for giving paraldehyde injection.
PMID- 10781250
TI - Reply
PMID- 10781251
TI - Magnesium sulphate for persistent pulmonary hypertension in newborns.
PMID- 10781252
TI - Unusual foreign body in the male urethra.
PMID- 10781254
TI - Reply
PMID- 10781255
TI - Fulminant hepatic failure.
PMID- 10781253
TI - Glucose and small for gestational age infants.
PMID- 10781256
TI - Reply
PMID- 10781257
TI - Nitrate kit for the diagnosis of urinary tract infection.
PMID- 10781258
TI - Reply
PMID- 10781259
TI - Cornelia de Lange syndrome: discordance in twins.
PMID- 10781260
TI - Cornelia de lange syndrome: discordance in twins
PMID- 10781261
TI - Influenza vaccination and asthma.
PMID- 10781262
TI - Difficult mask ventilation: an underestimated aspect of the problem of the
difficult airway?
PMID- 10781263
TI - Anesthetic concerns of spaceflight.
PMID- 10781264
TI - Isoflurane neuroprotection: a passing fantasy, again?
PMID- 10781265
TI - Thromboelastography: past, present, and future.
PMID- 10781266
TI - Prediction of difficult mask ventilation.
AB - BACKGROUND: Maintenance of airway patency and oxygenation are the main objectives
of face-mask ventilation. Because the incidence of difficult mask ventilation
(DMV) and the factors associated with it are not well known, we undertook this
prospective study. METHODS: Difficult mask ventilation was defined as the
inability of an unassisted anesthesiologist to maintain the measured oxygen
saturation as measured by pulse oximetry > 92% or to prevent or reverse signs of
inadequate ventilation during positive-pressure mask ventilation under general
anesthesia. A univariate analysis was performed to identify potential factors
predicting DMV, followed by a multivariate analysis, and odds ratio and 95%
confidence interval were calculated. RESULTS: A total of 1,502 patients were
prospectively included. DMV was reported in 75 patients (5%; 95% confidence
interval, 3.9-6.1%), with one case of impossible ventilation. DMV was anticipated
by the anesthesiologist in only 13 patients (17% of the DMV cases). Body mass
index, age, macroglossia, beard, lack of teeth, history of snoring, increased
Mallampati grade, and lower thyromental distance were identified in the
univariate analysis as potential DMV risk factors. Using a multivariate analysis,
five criteria were recognized as independent factors for a DMV (age older than 55
yr, body mass index > 26 kg/m2, beard, lack of teeth, history of snoring), the
presence of two indicating high likelihood of DMV (sensitivity, 0.72;
specificity, 0.73). CONCLUSION: In a general adult population, DMV was reported
in 5% of the patients. A simple DMV risk score was established. Being able to
more accurately predict DMV may improve the safety of airway management.
PMID- 10781267
TI - Airway management during spaceflight: A comparison of four airway devices in
simulated microgravity.
AB - BACKGROUND: The authors compared airway management in normogravity and simulated
microgravity with and without restraints for laryngoscope-guided tracheal
intubation, the cuffed oropharyngeal airway, the standard laryngeal mask airway,
and the intubating laryngeal mask airway. METHODS: Four trained anesthesiologist
divers participated in the study. Simulated microgravity during spaceflight was
obtained using a submerged, full-scale model of the International Space Station
Life Support Module and neutrally buoyant equipment and personnel. Customized,
full-torso manikins were used for performing airway management. Each
anesthesiologist-diver attempted airway management on 10 occasions with each
device in three experimental conditions: (1) with the manikin at the poolside
(poolside); (2) with the submerged manikin floating free (free-floating); and (3)
with the submerged manikin fixed to the floor using a restraint (restrained).
Airway management failure was defined as failed insertion after three attempts or
inadequate device placement after insertion. RESULTS: For the laryngoscope-guided
tracheal intubation, airway management failure occurred more frequently in the
free-floating (85%) condition than the restrained (8%) and poolside (0%)
conditions (both, P < 0.001). Airway management failure was similar among
conditions for the cuffed oropharyngeal airway (poolside, 10%; free-floating,
15%; restrained, 15%), laryngeal mask airway (poolside, 0%; free-floating, 3%;
restrained, 0%), and intubating laryngeal mask airway (poolside, 5%; free
floating, 5%; restrained, 10%). Airway management failure for the laryngoscope
guided tracheal intubation was usually caused by failed insertion (> 90%), and
for the cuffed oropharyngeal airway, laryngeal mask airway, and intubating
laryngeal mask airway, it was always a result of inadequate placement.
CONCLUSION: The emphasis placed on the use of restraints for conventional
tracheal intubation in microgravity is appropriate. Extratracheal airway devices
may be useful when restraints cannot be applied or intubation is difficult.
PMID- 10781268
TI - Citrate storage affects Thrombelastograph analysis.
AB - BACKGROUND: Thrombelastograph analysis (TEG) is used to evaluate blood
coagulation. Ideally, whole blood is immediately processed. If impossible, blood
may be citrated and assessed after recalcification. No data describe the effect
of such treatment and storage on TEG parameters. METHODS: Three studies were
performed in 90 surgical patients. In 30 patients, blood was citrated (1:10, 0.
129 M) and recalcified (20 microl 2 M CaCl2 to 340 microl citrated blood), and
TEG was performed with native blood and after recalcification after 0, 15, and 30
min of citrate storage. In another 30 patients, TEG was performed with citrated
blood recalcified immediately and after 1-72 h storage. In a third study,
thrombin-antithrombin complex, prothrombin fragment 1+2, and beta-thromboglobulin
were measured (using enzyme-linked immunoabsorbant assay tests) at corresponding
time points. Data were compared using repeated-measures analysis of variance and
post hocpaired t tests. RESULTS: TEG parameters were different in recalcified
citrated blood compared with native blood (P < 0.05) and changed significantly
during 30-min (P < 0.025) and 72-h (P < 0.001) citrate storage. TEG parameters
measured between 1 and 8 h of citrate storage were stable. Thrombin-antithrombin
complex and prothrombin fragment 1+2 values were not elevated in native blood.
After 30 min of citrate storage a gradual thrombin activation was observed, as
evidenced by increasing thrombin-antithrombin complex and prothrombin fragment
1+2 values (P < 0.05). beta-Thromboglobulin level was increased after 2 and 8 h
of citrate storage (P < 0.01). CONCLUSIONS: Analysis of native blood yields the
most reliable TEG results. Should immediate TEG processing not be possible,
citrated blood may be used if recalcified after 1-8 h.
PMID- 10781269
TI - Transesophageal echocardiographic hemodynamic monitoring during preoperative
acute normovolemic hemodilution.
AB - BACKGROUND: Preoperative acute normovolemic hemodilution may compromise oxygen
transport. The aims of our study were to describe the hemodynamic effects of
normovolemic hemodilution and to determine its effect on systolic and diastolic
cardiac function by multiplane transesophageal echocardiography. METHODS: In
eight anesthetized patients (aged 13-51 yr) without heart disease, hemoglobin was
reduced in steps from 123 +/- 8 (mean +/- SD) to 98 +/- 3 and to 79 +/- 5 g/l.
Hemodynamic measurements (intravascular pressures, thermodilution cardiac output,
and echocardiographic recordings) were obtained during a stabilization period and
at each level of hemodilution. Left ventricular wall motion was monitored
continuously, and Doppler variables, annular motion, and changes in ejection
fractional area were analyzed off-line. RESULTS: During hemodilution, cardiac
output by thermodilution increased by 16 +/- 7% and 26 +/- 10%, corresponding
well to the increase in cardiac output as measured by Doppler (difference, 0.32
+/- 1.2 l/min). Systemic vascular resistance fell 16 +/- 14% and 23 +/- 9% and
pulmonary capillary wedge pressure increased slightly (2 +/- 2 mmHg), whereas
other pressures, heart rate, wall motion, and diastolic Doppler variables
remained unchanged. Ejection fractional area change increased from 44 +/- 7% to
54 +/- 10% and 60 +/- 9% as a result of reduced end-systolic and increased end
diastolic left ventricular areas. CONCLUSIONS: A reduction in hemoglobin to 80
g/l during acute normovolemic hemodilution does not normally compromise systolic
or diastolic myocardial function as determined by transesophageal
echocardiography. Preload, left ventricular ejection fraction, and cardiac output
increase with a concomitant fall in systemic vascular resistance.
PMID- 10781270
TI - Neural mechanisms of antinociceptive effects of hypnosis.
AB - BACKGROUND: The neural mechanisms underlying the modulation of pain perception by
hypnosis remain obscure. In this study, we used positron emission tomography in
11 healthy volunteers to identify the brain areas in which hypnosis modulates
cerebral responses to a noxious stimulus. METHODS: The protocol used a factorial
design with two factors: state (hypnotic state, resting state, mental imagery)
and stimulation (warm non-noxious vs. hot noxious stimuli applied to right thenar
eminence). Two cerebral blood flow scans were obtained with the 15O-water
technique during each condition. After each scan, the subject was asked to rate
pain sensation and unpleasantness. Statistical parametric mapping was used to
determine the main effects of noxious stimulation and hypnotic state as well as
state-by-stimulation interactions (i.e., brain areas that would be more or less
activated in hypnosis than in control conditions, under noxious stimulation).
RESULTS: Hypnosis decreased both pain sensation and the unpleasantness of noxious
stimuli. Noxious stimulation caused an increase in regional cerebral blood flow
in the thalamic nuclei and anterior cingulate and insular cortices. The hypnotic
state induced a significant activation of a right-sided extrastriate area and the
anterior cingulate cortex. The interaction analysis showed that the activity in
the anterior (mid-)cingulate cortex was related to pain perception and
unpleasantness differently in the hypnotic state than in control situations.
CONCLUSIONS: Both intensity and unpleasantness of the noxious stimuli are reduced
during the hypnotic state. In addition, hypnotic modulation of pain is mediated
by the anterior cingulate cortex.
PMID- 10781271
TI - Smoking decreases alveolar macrophage function during anesthesia and surgery.
AB - BACKGROUND: Smoking changes numerous alveolar macrophage functions and is one of
the most important risk factors for postoperative pulmonary complications. The
current study tested the hypothesis that smoking impairs antimicrobial and
proinflammatory responses in alveolar macrophages during anesthesia and surgery.
METHOD: The authors studied 30 smoking and 30 nonsmoking patients during propofol
fentanyl general anesthesia. Alveolar immune cells were harvested by
bronchoalveolar lavage immediately and 2, 4, and 6 h after induction of
anesthesia and at the end of surgery. The types of alveolar immune cell and
macrophage aggregation were determined. The authors measured opsonized and
unopsonized phagocytosis. Microbicidal activity was determined as the ability of
the macrophages to kill Listeriamonocytogenes directly. Finally, RNA was
extracted from harvested cells and cDNA was synthesized by reverse transcription.
The expression of interleukin 1beta, 6, and 8, interferon gamma, and tumor
necrosis factor alpha were measured by semiquantitative polymerase chain reaction
using beta-actin as an internal standard. RESULTS: The fraction of aggregated
macrophages increased significantly over time in both groups, whereas
phagocytosis of opsonized and nonopsonized particles and microbicidal activity of
alveolar macrophages decreased significantly. The changes, though, were nearly
twice as great as in patients who smoked. Gene expression of all proinflammatory
cytokines in alveolar immune cells except interleukin 6 increased 2- to 20-fold
over time in both groups. The expression of interleukin 1beta, interferon gamma,
and tumor necrosis factor alpha, however, increased only half as much in smokers
as in nonsmokers. CONCLUSION: Smoking was associated with macrophage aggregation
but markedly reduced phagocytic and microbicidal activity-possibly because
expression of proinflammatory cytokines was reduced in these patients. Our data
thus suggest that smokers may have a limited ability to mount an effective
pulmonary immune defense after anesthesia and surgery.
PMID- 10781273
TI - Sinus nodal function and risk for atrial fibrillation after coronary artery
bypass graft surgery.
AB - BACKGROUND: Nonsurgical patients with sinus node dysfunction are at high risk for
atrial tachyarrhythmias, but whether a similar relation exists for atrial
fibrillation after coronary artery bypass graft surgery is not clear. The purpose
of this study was to evaluate sinus nodal function before and after coronary
artery bypass graft surgery and to evaluate its relation with the risk for
postoperative atrial arrhythmias. METHODS: Sixty patients without complications
having elective coronary artery bypass graft surgery underwent sinus nodal
function testing by measurement of sinoatrial conduction time (SACT) and
corrected sinus nodal recovery time (CSNRT). Patients were categorized based on
whether postoperative atrial fibrillation developed. RESULTS: Twenty patients
developed atrial fibrillation between postoperative days 1 through 3. For
patients remaining in sinus rhythm (n = 40), sinoatrial conduction times were no
different and corrected sinus nodal recovery times were shorter after surgery
when compared with measurements obtained after anesthesia induction. Sinus node
function test results before surgery were similar between the sinus rhythm and
the atrial fibrillation groups. After surgery, patients who later developed
atrial fibrillation had longer sinoatrial conduction times compared with the
sinus rhythm group (P = 0.006), but corrected sinus nodal recover time was not
different between these groups. A sinoatrial conduction time > 96 ms measured at
this time point was associated with a 7.3-fold increased risk of postoperative
atrial fibrillation (sensitivity, 62%; specificity, 81%; positive and negative
predictive values, 56% and 85%, respectively; area under the receiver operator
characteristic curve, 0.72). CONCLUSIONS: These data show that sinus nodal
function is not adversely affected by uncomplicated coronary artery bypass
surgery. Patients who later developed atrial fibrillation, however, had prolonged
sinoatrial conduction immediately after surgery compared with patients remaining
in sinus rhythm. These results suggest that injury to atrial conduction tissue at
the time of surgery predisposes to postoperative atrial fibrillation and that
assessment of sinoatrial conduction times could provide a means of identifying
patients at high risk for postoperative atrial fibrillation.
PMID- 10781272
TI - Ophthalmic regional anesthesia: medial canthus episcleral (sub-tenon) anesthesia
is more efficient than peribulbar anesthesia: A double-blind randomized study.
AB - BACKGROUND: Regional anesthesia and especially peribulbar anesthesia commonly is
used for cataract surgery. Failure rates and need for reinjection remains high,
however, with peribulbar anesthesia. Single-injection high-volume medial canthus
episcleral (sub-Tenon's) anesthesia has proven to be an efficient and safe
alternative to peribulbar anesthesia. METHODS: The authors, in a blind study,
compared the effectiveness of both techniques in 66 patients randomly assigned to
episcleral anesthesia or single-injection peribulbar anesthesia. Motor blockade
(akinesia) was used as the main index of anesthesia effectiveness. It was
assessed using an 18-point scale (0-3 for each of the four directions of the
gaze, lid opening, and lid closing, the total being from 0 = normal mobility to
18 = no movement at all). This score was compared between the groups 1, 5, 10,
and 15 min after injection and at the end of the surgical procedures. Time to
onset of the blockade also was compared between the two groups, as was the
incidence of incomplete blockade with a need for supplemental injection and the
satisfaction of the surgeon, patient, and anesthesiologist. RESULTS: Episcleral
anesthesia provided a quicker onset of anesthesia, a better akinesia score, and a
lower rate of incomplete blockade necessitating reinjection (0 vs. 39%; P <
0.0001) than peribulbar anesthesia. Even after supplemental injection, peribulbar
anesthesia had a lower akinesia score than did episcleral anesthesia. Peribulbar
anesthesia began to wear off during surgery, whereas episcleral anesthesia did
not. CONCLUSION: Medial canthus single-injection episcleral anesthesia is a
suitable alternative to peribulbar anesthesia. It provides better akinesia, with
a quicker onset and more constancy in effectiveness.
PMID- 10781274
TI - Acoustic reflectometry profiles of endotracheal and esophageal intubation.
AB - BACKGROUND: Acoustic reflectometry can be used to create a "one-dimensional
image" of a cavity, such as the airway and lung, with the image displayed as an
area-length curve. This pilot study was undertaken to determine whether acoustic
reflectometry could be used to distinguish between an endotracheal and an
esophageal intubation. METHODS: Ten adult patients underwent general endotracheal
anesthesia and neuromuscular blockade. The reflectometer wavetube was attached to
an endotracheal tube, and a reflectometric profile was obtained of the
endotracheal tube and the airway and lung cavity. After confirmation of tracheal
intubation, a second endotracheal tube was placed in the esophagus. After four
breaths were administered, a reflectometric profile of the endotracheal tube
esophagus cavity was obtained. RESULTS: The acoustic reflectometric profiles for
tracheal and esophageal intubation profiles were distinctive and characteristic.
For an endotracheal tube-airway cavity, the profile shows a constant cross
sectional area throughout the length of the endotracheal tube, followed by a
rapid rise in the area past the carina. For an esophageal intubation, the profile
shows constant cross-sectional area throughout the length of the endotracheal
tube, followed by a sudden decrease in the cross-sectional area to zero.
CONCLUSIONS: In this pilot study, acoustic reflectometry within seconds, and
without resort to capnography, was able to generate characteristic and
distinctive area-length profiles for both endotracheal and esophageal intubation.
Acoustic reflectometry may have a role in the emergency imaging of the airway,
and in the immediate detection of esophageal intubations, particularly in cases
of cardiopulmonary arrest in which the usual techniques for confirmation of
breathing tube placement fail.
PMID- 10781275
TI - Changes in the auditory evoked potentials and the bispectral index following
propofol or propofol and alfentanil.
AB - BACKGROUND: Midlatency auditory evoked potentials (MLAEP) show graded changes
with increasing doses of hypnotics but little change with opioids. The effect of
their combination on the MLAEP was evaluated. Also, the bispectral index (BIS)
was compared with the ability of MLAEP to correlate with sedation and predict
loss of consciousness. METHODS: Twenty healthy volunteers were randomly assigned
to receive stepped increases in propofol concentration (10 subjects) or propofol
plus alfentanil 100 ng/ml (10 subjects). At baseline and at each targeted effect
site concentration the mean MLAEP, BIS, measures of sedation, and drug
concentration were obtained. The relation among MLAEP, BIS, and sedation score
was determined. The prediction probability (Pk) was calculated and compared for
BIS and MLAEP. RESULTS: The BIS and MLAEP patterns showed significant changes (Pa
and Nb decreased in amplitude and increased in latency) with increasing level of
sedation (P < 0.0001). The BIS correlated better with sedation scores (0.884)
than did the MLAEP (P < 0.05). Pa and Nb latencies showed the best correlation
with sedation levels (0.685 and 0.658, respectively). The addition of alfentanil
did not affect the relation between MLAEP and loss of consciousness (P > 0.15).
The BIS (Pk = 0.952) was a better predictor of loss of consciousness than were Pa
and Nb amplitude (P < 0.05) but were comparable to Pa and Nb latency (Pk = 0.869
and 0. 873, respectively). CONCLUSION: MLAEP changes, like the BIS, correlate
well with increasing sedation produced by propofol, and these changes in the
MLAEP are independent of the presence of an opioid. Among all the MLAEP
parameters, Pa and Nb latencies are the best predictors of increasing sedation
and loss of consciousness.
PMID- 10781276
TI - Patients with diabetic neuropathy are at risk of a greater intraoperative
reduction in core temperature.
AB - BACKGROUND: Core hypothermia develops after the induction of general anesthesia,
but intraoperative vasoconstriction usually prevents its progression. However,
diabetes mellitus is often associated with autonomic neuropathy, which leads to
abnormal peripheral neurovascular function. Accordingly, we tested the hypothesis
that diabetic patients experience a greater reduction in core temperature during
general anesthesia than nondiabetic patients. METHODS: We studied 36 nondiabetic
patients (control group) and 27 diabetic patients (diabetic group) undergoing
elective abdominal surgery. Both groups were divided into young (< 60 yr) and
older age (>/= 60 yr) groups. Standard noninvasive autonomic tests (heart rate
variation at deep periodical breathing, Valsalva maneuver, and head-up tilt) were
carried out for each patient. The relation between the results of these tests of
autonomic function and the tympanic membrane temperature during general
anesthesia was assessed in relation to peripheral vasoconstriction. RESULTS:
Thirteen patients in the diabetic group showed abnormal responses to two or more
of the basal autonomic function tests (patients with autonomic dysfunction).
Changes in core temperature among the groups were similar at 90 min after the
induction of anesthesia. However, the core temperature of the diabetic patients
with autonomic dysfunction was lower from 120 min (35.1 degrees C) onward
compared with the young or older nondiabetic patients and the diabetic patients
with normal autonomic function. Peripheral vasoconstriction, evaluated using the
forearm-fingertip skin surface temperature gradient, was delayed in patients with
autonomic dysfunction compared with the others. CONCLUSIONS: The current results
indicate that diabetic autonomic neuropathy is associated with more severe
intraoperative hypothermia. We postulate that diabetic patients become more
hypothermic because their peripheral neuropathy delays the onset of
thermoregulatory vasoconstriction and reduces its efficacy once triggered. These
patients may therefore fail to develop a normal core temperature plateau.
PMID- 10781277
TI - Jugular venous bulb oxygen saturation in patients with preexisting diabetes
mellitus or stroke during normothermic cardiopulmonary bypass.
AB - BACKGROUND: The authors hypothesized that patients with cerebrovascular
abnormalities or metabolic disorders may experience abnormality in cerebral
circulation more frequently than patients without these risks. The current study
attempted to assess jugular venous bulb oxygen saturation (SjvO2) in patients
with preexisting diabetes mellitus or stroke undergoing normothermic
cardiopulmonary bypass. METHODS: Thirty-nine patients undergoing elective
coronary artery bypass graft surgery were studied, including 19 age-matched
control patients, 10 diabetic patients, and 9 patients with preexisting stroke A
4.0-French fiberoptic oximetry oxygen saturation catheter was inserted into the
right jugular bulb to continuously monitor internal SjvO2. Hemodynamic parameters
and arterial and jugular venous blood gases were measured at seven time points:
(1) after the induction of anesthesia and before the start of surgery, (2) just
after the beginning of cardiopulmonary bypass, (3) 20 min after the beginning of
bypass, (4) 40 min after the beginning of bypass, (5) 60 min after the beginning
of bypass, (6) just after the cessation of bypass, and (7) at the end of the
operation. RESULTS: No significant differences were seen in mean arterial
pressure, arterial carbon dioxide tension (PaCO2), or hemoglobin concentration
among the three groups during the study. The SjvO2 value did not differ among the
three groups after anesthesia induction and before surgery, just after the
beginning of cardiopulmonary bypass, 60 min after the beginning of bypass, just
after the end of bypass, or at the end of the operation. Significant differences
between the control group and the diabetic and stroke groups were observed,
however, at 20 min and 40 min after the beginning of bypass (at 20 min: control
group 62.2 +/- 6.8%, diabetes group 48.4 +/- 5.1%, stroke group 45.9 +/- 6.3%; at
40 min: control group 62.6 +/- 5.2%, diabetes group 47.1 +/- 5.2%, stroke group
48.8 +/- 4.1% [values expressed as the mean +/- SD]; P < 0.05). Also, values in
the diabetes and stroke groups were decreased at 20 min and 40 min after the
beginning of bypass compared with before the start of surgery. CONCLUSIONS: A
reduced SjvO2 value was observed more frequently in patients with preexisting
diabetes mellitus or stroke during normothermic cardiopulmonary bypass. It is
possible that cerebral circulation during normothermic bypass is altered in
patients with risk factors for cerebrovascular disorder.
PMID- 10781278
TI - Predictors of hypothermia during spinal anesthesia.
AB - BACKGROUND: Body temperature often is ignored during regional anesthesia, despite
evidence that hypothermia occurs commonly. Because hypothermia is associated with
adverse clinical outcomes, it is important to recognize predictors of hypothermia
and to monitor and control body temperature in patients at risk. The current
study was designed to determine the predictors of core hypothermia in patients
receiving spinal anesthesia for radical retropubic prostatectomy. METHODS: Forty
four patients undergoing radical retropubic prostatectomy were studied. A lumbar
intrathecal injection of 18-22 mg bupivacaine, 0.75%, with 20 microg fentanyl was
given. No active warming measures were used other than intravenous fluid warming.
The following clinical variables were assessed as potential predictors of core
(tympanic) temperature at admission to the postanesthesia care unit: duration of
surgery, average ambient operating room temperature, body habitus, age, and
spinal blockade level. RESULTS: The mean core temperature at admission to the
postanesthesia care unit was 35.1 +/- 0.6 degrees C (range, 33.6-36.3 degrees C).
Duration of surgery, ambient operating room temperature, and body habitus were
not predictors of hypothermia. A high level of spinal blockade and increasing age
were predictors of hypothermia. For each incremental increase in block level,
core temperature decreased by 0.15 degrees C, and for each increase in age, core
temperature decreased by 0.3 degrees C. CONCLUSIONS: Although high-level spinal
blockade has been associated with decreased thermoregulatory thresholds, no
previous study has shown that a higher level of blockade is associated with a
greater magnitude of core hypothermia in the clinical setting. As with general
anesthesia, advanced age is associated with hypothermia during spinal anesthesia.
PMID- 10781279
TI - Isoflurane delays but does not prevent cerebral infarction in rats subjected to
focal ischemia.
AB - BACKGROUND: Several investigations have shown that volatile anesthetics can
reduce ischemic cerebral injury. In these studies, however, neurologic injury was
evaluated only after a short recovery period. Recent data suggest that injury
caused by ischemia is a dynamic process characterized by continual neuronal loss
for a prolonged period. Whether isoflurane-mediated neuroprotection is sustained
after a longer recovery period is not known. The current study was conducted to
compare the effect of isoflurane on brain injury after short (2-day) and long (14
day) recovery periods in rats subjected to focal ischemia. METHODS: Fasted Wistar
Kyoto rats were anesthetized with isoflurane and randomly allocated to an awake
(n = 36) or an isoflurane (n = 34) group. Animals in both groups were subjected
to focal ischemia by filament occlusion of the middle cerebral artery.
Pericranial temperature was servocontrolled at 37 degrees C throughout the
experiment. In the awake group, isoflurane was discontinued and the animals were
allowed to awaken. In the isoflurane group, isoflurane anesthesia was maintained
at 1.5 times the minimum alveolar concentration. After 70 min of focal ischemia,
the filament was removed. Animals were killed 2 days (awake, n = 18; isoflurane,
n = 17) and 14 days (awake, n = 18; isoflurane, n = 17) after ischemia. The
volumes of cerebral infarction and selective neuronal necrosis in the animals
were determined by image analysis of hematoxylin and eosin-stained coronal brain
sections. RESULTS: Cortical and subcortical volumes of infarction were
significantly less in the isoflurane 2-day group (26 +/- 23 mm3 and 17 +/- 6 mm3,
respectively) than in the awake 2-day group (58 +/- 35 mm3, P < 0. 01; and 28 +/-
12 mm3, P < 0.01, respectively). By contrast, cortical and subcortical volumes of
infarction in the awake (41 +/- 31 mm3 and 28 +/- 16 mm3, respectively) and
isoflurane (41 +/- 35 mm3 and 19 +/- 8 mm3, respectively) 14-day groups were not
different (cortex, P = 0.99; subcortex, P = 0.08). The volume of cortical tissue
in which selective neuronal necrosis was observed, however, was significantly
less in the isoflurane 14-day group (5 +/- 4 mm3) than in the awake 14-day group
(17 +/- 9 mm3, P < 0.01). The total number of necrotic neurons in the region of
selective neuronal necrosis was significantly smaller in the isoflurane 14-day
group than in the awake 14-day group (P < 0.01). CONCLUSION: Compared with the
awake state, isoflurane reduced the extent of infarction assessed 2 days after
focal ischemia in rats. At 14 days, however, only selective neuronal necrosis,
but not infarction, was reduced by isoflurane. These results suggest that
isoflurane delays but does not prevent cerebral infarction caused by focal
ischemia. Isoflurane may attenuate the delayed development of selective neuronal
necrosis in periinfarct areas in this animal model.
PMID- 10781280
TI - Anesthetics and mild hypothermia similarly prevent hippocampal neuron death in an
in vitro model of cerebral ischemia.
AB - BACKGROUND: General anesthetics reduce neuron loss following focal cerebral
ischemia in rodents. The relative efficacy of this action among different
anesthetics clinically used for neuroprotection is uncertain. In addition, it
remains unclear how anesthetics compare to neuroprotection afforded by mild
hypothermia. This study was performed to evaluate the comparative effects of
isoflurane, sodium pentothal, and mild hypothermia in a hippocampal slice model
of cerebral ischemia and to determine if the mechanism of neuroprotection of
isoflurane involves inhibition of glutamate excitotoxicity. METHODS: Survival and
morphology of CA1, CA3, and dentate gyrus neurons in rat hippocampal slices were
examined after 10 or 20 min of combined oxygen-glucose deprivation (in vitro
ischemia) followed by a 5-h recovery period. RESULTS: 10 or 20 min in vitro
ischemia at 37 degrees C killed 35-40% of neurons in CA1 (P < 0.001), 6% in CA3
(not significant) and 18% in dentate (P < 0.05). Isoflurane (0.7 and 2.0%,
approximately 0.45 and 1.5 minimum alveolar concentration), pentothal (50 microm,
approximately 1 minimum alveolar concentration equivalent) and mild hypothermia
(34 degrees C) all reduced CA1 cell loss and morphologic damage to similar
degrees in 10- and 20-min periods of ischemia (P < 0.001). The noncompetitive N
methyl-D-aspartate antagonist MK-801 prevented cell damage, showing that N-methyl
D-aspartate receptor activation is an important mechanism of injury in this
model. Glutamate (1 mm) produced cell loss similar to in vitro ischemia.
Isoflurane (2%) prevented cell damage from glutamate exposure. CONCLUSIONS: In
hippocampal slices, neuron death from simulated ischemia was predominately due to
activation of glutamate receptors. Isoflurane, sodium pentothal, an N-methyl-D
aspartate receptor antagonist, and mild hypothermia prevented cell death to
similar degrees. For isoflurane, the mechanism appears to involve attenuation of
glutamate excitotoxicity.
PMID- 10781281
TI - Spinal tonicaine: potency and differential blockade of sensory and motor
functions.
AB - BACKGROUND: Long-acting local anesthetics are beneficial for the management of
postoperative pain and chronic pain. The authors recently reported that a single
injection of N-beta-phenylethyl-lidocaine (tonicaine), a quaternary lidocaine
derivative, effectively blocks rat sciatic nerve function four to nine times
longer than lidocaine, with a predominance of sensory versusmotor blockade. The
purposes of this study were to measure directly the potency of this charged drug
by internal perfusion of cultured neuronal cells, and to evaluate the
differential blockade of sensory versus motor function via spinal route in rats.
METHODS: The tonic and additional use-dependent blockade of Na+ currents by
internal tonicaine was assayed in cultured GH3 cells during whole cell voltage
clamp conditions. In addition, tonicaine was injected into the intrathecal space
of rats at intervertebral space L4-L5, and the proprioceptive, motor, and sensory
functions, and tissue integrity, subsequently were evaluated. RESULTS: Internal
application of tonicaine in GH3 cells revealed that it was approximately 80 times
more potent in blocking Na+ currents than was externally applied lidocaine. In
vivotesting in a rat neuraxial anesthesia model showed that tonicaine at 0.5 mm
produced blockade that lasted much longer than that produced by bupivacaine even
at approximately a 55 times higher concentration (28.8 mm). Tonicaine spinal
block also produced a longer duration of sensory than motor blockade (112.5 +/-
16.3 min vs. 45.8 +/- 7.1 min). Evidence of neurotoxicity was seen at a
concentration of 1.0 mm. CONCLUSION: In vitro testing shows that tonicaine
displays a higher affinity for the local anesthetic binding site than does
lidocaine; in vivotesting indicates that tonicaine elicits sensory blockade of a
duration significantly longer than that elicited by bupivacaine. Tonicaine,
however, has a narrow therapeutic index, with substantial neurotoxicity at 1 mm
in rats, and may have limited clinical value.
PMID- 10781282
TI - FK506 (tacrolimus) increases halothane-induced Ca2+ release from skeletal muscle
sarcoplasmic reticulum.
AB - BACKGROUND: FK506 binding protein is closely associated with the sarcoplasmic
reticulum ryanodine receptor-channel and can modulate its function. The ryanodine
receptor is stabilized by its association with FK506 binding protein. The
immunosuppressant drugs FK506 (tacrolimus) and rapamycin can promote dissociation
of FK506 binding protein from the ryanodine receptor 1 and by this mechanism
increase sensitivity of ryanodine receptor 1 to agonists such as caffeine.
Furthermore, it was shown recently that treatment of normal human skeletal muscle
with FK506 and rapamycin increased halothane-induced contracture. The authors
investigated the effect of the immunosuppressants FK506 and rapamycin on
halothane-induced Ca2+ release in skeletal muscle sarcoplasmic reticulum
vesicles. METHODS: Skeletal muscle terminal cisterns were isolated from New
Zealand White rabbits. Ca2+ uptake and release was monitored in skeletal muscle
sarcoplasmic reticulum vesicles using the fluo-3 fluorescent technique. Western
Blot analysis of FK506 binding protein was performed using standard protocol.
RESULTS: The authors observed that treatment of skeletal muscle sarcoplasmic
reticulum vesicles with FK506 and rapamycin enhances halothane-induced Ca2+
release by about five times. Furthermore, the Ca2+ release induced by halothane
in the presence of FK506 was inhibited by several antagonists of the ryanodine
receptor, such as ruthenium red, spermine, and Mg2+. CONCLUSION: Dissociation of
FK506 binding protein from its binding site in skeletal muscle sarcoplasmic
reticulum vesicles can modulate halothane-induced Ca2+ release through the
ryanodine receptor. Data are discussed in relation to the role of the FK506
binding protein in modulating the effect of halothane on the ryanodine receptor
and the development of malignant hyperthermia phenotype.
PMID- 10781283
TI - Rapid and direct modulation of GABAA receptors by halothane.
AB - BACKGROUND: Hypotheses regarding the nature of channel modulation by volatile
anesthetics have focused primarily on "membrane actions" of anesthetics and more
recently on direct actions of volatile agents on receptor proteins themselves.
With the recognition that many channels are subject to modulation by
intracellular enzymes, such as protein kinases and phosphatases, and recent
demonstrations that the activity of these modulators themselves may be altered by
anesthetic agents, a third possibility has been suggested:-anesthetic actions on
channels may be indirect, produced, for example, via direct effects on
intracellular enzyme systems. METHODS: To determine the contribution of indirect
versus direct modulation, the authors compared effects of the volatile anesthetic
halothane on gamma-aminobutyric acid A receptors under two conditions: in the
whole cell configuration with intact intracellular regulatory systems, and in the
excised patch configuration, in which intracellular signaling systems have been
disrupted. They also evaluated the effects of rapid application and withdrawal of
anesthetic to determine the time course of onset and offset of the anesthetic
actions on these channels. RESULTS: Characteristic changes in gamma-aminobutyric
acid A receptor function occurred in excised patches as in whole cells, did not
require alteration of receptor phosphorylation, and were rapid (onset and offset
of anesthetic action occurred within milliseconds). CONCLUSIONS: These results
are not consistent with indirect modulation but rather indicate that volatile
agents modulate gamma-aminobutyric acid A receptors by direct action on the
channel complex or surrounding lipid membrane.
PMID- 10781284
TI - Intrathecal dexmedetomidine attenuates hypercapnic but not hypoxic cerebral
vasodilation in anesthetized rabbits.
AB - BACKGROUND: Systemic dexmedetomidine (DXM) attenuates the cerebral vasodilation
induced by hypercapnia and decreases the cerebral blood flow response to hypoxia.
We determined whether lumbar intrathecal DXM affected the cerebrovascular
reactivity to hypercapnia and hypoxia. METHODS: Rabbits (n = 55) anesthetized
with pentobarbital were prepared for measurement of pial vessel diameters using a
closed cranial window preparation. The first study evaluated the response to
hypercapnia after intrathecal administration of DXM (2 microg/kg; n = 7) or
normal saline (n = 8). The second evaluated the response to hypercapnia after
intrathecal DXM in the presence of yohimbine (20 microg/kg followed by DXM 2
microg/kg; n = 7). The third evaluated the response to mild or moderate hypoxia
after intrathecal DXM (2 microg/kg; n = 7) or normal saline (n = 7). The
hypercapnic responses were also examined in the presence of systemic DXM (2, 10
microg/kg; n = 6), topical DXM (10-8 m, 10-6 m; n = 6) and of intrathecal
clonidine (2 microg/kg; n = 7). RESULTS: The pial arteriolar dilator response to
hypercapnia was significantly attenuated after intrathecal administration of DXM.
Pretreatment with yohimbine completely blocked the decreased reactivity to
hypercapnia. Intrathecal clonidine, although less than DXM, also attenuate the
hypercapnic response. Intrathecal DXM did not affect the vasodilation of pial
arterioles induced by mild or moderate hypoxia. The systemic DXM 10 microg/kg and
topical DXM 10-6 m, but not systemic 2 microg/kg and topical 10-8 m, attenuated
hypercapnic vasodilation of pial arterioles. CONCLUSIONS: The presence of alpha2
adrenoceptor agonist administered intrathecally into the lumbar spinal region
attenuates hypercapnic but not hypoxic cerebral vasodilation, probably via a
stimulation of central alpha2-adrenergic receptors of the central nervous system.
PMID- 10781285
TI - Succinylcholine metabolite succinic acid alters steady state activation in muscle
sodium channels.
AB - BACKGROUND: Animal experiments revealed that succinylcholine produced masseter
muscle rigidity and activated myotonic discharges despite neuromuscular blockade
with a nondepolarizing blocker. These results suggest that either succinylcholine
or its metabolites might interfere directly with voltage-operated ion channels of
the sarcolemma. The aim of this study was to examine effects of one product of
succinylcholine hydrolysis, succinic acid, on voltage-gated muscle sodium (Na+)
channels. METHODS: Alpha subunits of human muscle sodium channels were
heterologously expressed in HEK293 cells. Activation of Na+ currents was examined
applying standard whole-cell voltage-clamp protocols in the absence (control and
washout) and presence of succinic acid in different concentrations (0.05-10 mm).
RESULTS: Succinic acid shifted the midpoints of steady state activation plots in
the direction of more negative test potentials, indicating that channels open
during smaller depolarizations in the presence of the drug. The maximum amount of
the negative shift in 10 mm succinic acid was -6.3 +/- 1.7 mV; the EC50 for this
effect was 0.39 mm. In addition, succinic acid (10 mm) significantly enhanced
maximum currents after depolarizations with respect to a series of control
experiments. CONCLUSION: Succinic acid facilitates voltage-dependent activation
in muscle sodium channels in vitro. This might lead to muscle hyperexcitability
in vivo.
PMID- 10781286
TI - Opiate-induced analgesia is increased and prolonged in mice lacking P
glycoprotein.
AB - BACKGROUND: P-glycoprotein is a transmembrane protein expressed by multiple
mammalian cell types, including the endothelial cells that comprise the blood
brain-barrier. P-glycoprotein functions to actively pump a diverse array of
xenobiotics out of the cells in which it is expressed. The purpose of this study
was to determine if P-glycoprotein alters the analgesic efficacy of clinically
useful opioids. METHODS: Using a standard hot-plate method, the magnitude and
duration of analgesia from morphine, morphine-6-glucuronide, methadone,
meperidine, and fentanyl were assessed in wild-type Friends virus B (FVB) mice
and in FVB mice lacking P-glycoprotein [mdr1a/b(-/-)]. Analgesia was expressed as
the percent maximal possible effect (%MPE) over time, and these data were used to
calculate the area under the analgesia versus time curves (AUC) for all opioids
studied. In addition, the effect of a P-glycoprotein inhibitor (cyclosporine, 100
mg/kg) on morphine analgesia in both wild-type and mdr knockout mice was also
determined. RESULTS: Morphine induced greater analgesia in knockout mice compared
with wild-type mice (AUC 6,450 %MPE min vs. 1,610 %MPE min at 3 mg/kg), and
morphine brain concentrations were greater in knockout mice. Analgesia was also
greater in knockout mice treated with methadone and fentanyl but not meperidine
or morphine-6-glucuronide. Cyclosporine pretreatment markedly increased morphine
analgesia in wild-type mice but had no effect in knockout mice. CONCLUSIONS:
These results suggest that P-glycoprotein acts to limit the entry of some opiates
into the brain and that acute administration of P-glycoprotein inhibitors can
increase the sensitivity to these opiates.
PMID- 10781287
TI - Isoflurane preconditions myocardium against infarction via activation of
inhibitory guanine nucleotide binding proteins.
AB - BACKGROUND: Isoflurane-induced myocardial protection during ischemia is mediated
by adenosine triphosphate-regulated potassium (KATP) channels; however, the
intracellular signal transduction cascade responsible for this process has been
incompletely evaluated. The authors tested the hypothesis that isoflurane reduces
myocardial infarct size through a Gi protein-mediated process. METHODS: Forty
eight hours after pretreatment with vehicle (0.9% saline) or the Gi protein
inhibitor pertussis toxin (10 microg/kg intravenously), barbiturate-anesthetized
dogs (n = 43) were instrumented for measurement of aortic and left ventricular
pressures and maximum rate of increase of left ventricular pressure. All dogs
were subjected to a 60-min left anterior descending coronary artery occlusion
followed by 3-h reperfusion. In four separate groups, vehicle- or pertussis toxin
pretreated dogs were studied with or without administration of 1 minimum alveolar
concentration isoflurane. In two additional groups, dogs received the direct KATP
channel agonist nicorandil (100 microg/kg bolus and 10 microg x kg-1 x min-1
intravenous infusion) in the presence or absence of pertussis toxin pretreatment.
Myocardial perfusion and infarct size were measured with radioactive microspheres
and triphenyltetrazolium staining, respectively. RESULTS: Isoflurane
significantly (P < 0.05) decreased infarct size to 7 +/- 2% of the area at risk
compared with control experiments (26 +/- 2%). Pertussis toxin pretreatment alone
had no effects on myocardial infarct size (31 +/- 4%) but blocked the beneficial
effects of isoflurane (21 +/- 3%). Nicorandil decreased infarct size (11 +/- 2%),
but, in contrast to isoflurane, this effect was independent of pertussis toxin
pretreatment (11 +/- 1%). CONCLUSION: Isoflurane reduces myocardial infarct size
by a Gi protein-mediated mechanism in vivo.
PMID- 10781288
TI - Differential neurotoxic effects of propofol on dissociated cortical cells and
organotypic hippocampal cultures.
AB - BACKGROUND: Propofol is a widely used anesthetic agent for adults and children.
Although extensive clinical use has demonstrated its safety, neurologic
dysfunctions have been described after the use of this agent. A recent study on a
model of aggregating cell cultures reported that propofol might cause
irreversible lesions of gamma-aminobutyric acid-mediated (GABAergic) neurons when
administered at a critical phase of brain development. We investigated this issue
by comparing the effects of long-term propofol treatment on two models of brain
cultures: dissociated neonatal cortical cell cultures and organotypic slice
cultures. METHODS: Survival of GABAergic neurons in dissociated cultures of
newborn rat cortex (postnatal age, 1 day) treated for 3 days with different
concentrations of propofol was assessed using histologic and cytochemical
methods. For hippocampal organotypic slice cultures (postnatal age, 1 and 7
days), cell survival was assessed by measuring functional and morphologic
parameters: extracellular and intracellular electrophysiology, propidium staining
of dying cells, and light and electron microscopy. RESULTS: In dissociated
neonatal cell cultures, propofol induced dose-dependent lesions of GABAergic
neurons and of glial cells. In contrast, no evidence for neurotoxic effects of
propofol were found after long-term treatment of organotypic slice cultures.
Excitatory transmission was not affected by propofol, and inhibitory transmission
was still functional. Histologic preparations showed no evidence for cell
degeneration or death. CONCLUSION: Although long-term applications of propofol to
dissociated cortical cell cultures produced degeneration and death of GABAergic
neurons and glial cells, no such lesions were found when using a model of
postnatal organotypic slice cultures. This conclusion is based on both functional
and morphologic tests.
PMID- 10781289
TI - Intravenous anesthetics differentially modulate ligand-gated ion channels.
AB - BACKGROUND: Heteromeric neuronal nicotinic acetylcholine receptors (nAChRs) are
potently inhibited by volatile anesthetics, but it is not known whether they are
affected by intravenous anesthetics. Ketamine potentiates gamma-aminobutyric acid
type A (GABAA) receptors at high concentrations, but it is unknown whether there
is potentiation at clinically relevant concentrations. Information about the
effects of intravenous anesthetics with different behavioral profiles on specific
ligand-gated ion channels may lead to hypotheses as to which ion channel effect
produces a specific anesthetic behavior. METHODS: A heteromeric nAChR composed of
alpha4 and beta4 subunits was expressed heterologously in Xenopus laevis oocytes.
Using the two-electrode voltage clamp technique, peak ACh-gated current was
measured before and during application of ketamine, etomidate, or thiopental. The
response to GABA of alpha1beta2gamma2s GABAA receptors expressed in human
embryonic kidney cells and Xenopus oocytes was compared with and without
coapplication of ketamine from 1 microm to 10 mm. RESULTS: Ketamine caused
potent, concentration-dependent inhibition of the alpha4beta4 nAChR current with
an IC50 of 0.24 microm. The inhibition by ketamine was use-dependent; the
antagonist was more effective when the channel had been opened by agonist.
Ketamine did not modulate the alpha1beta2gamma2s GABAA receptor response in the
clinically relevant concentration range. Thiopental caused 27% inhibition of ACh
response at its clinical EC50. Etomidate did not modulate the alpha4beta4 nAChR
response in the clinically relevant concentration range, although there was
inhibition at very high concentrations. CONCLUSIONS: The alpha4beta4 nAChR, which
is predominantly found in the central nervous system (CNS), is differentially
affected by clinically relevant concentrations of intravenous anesthetics.
Ketamine, commonly known to be an inhibitor at the N-methyl-D-aspartate receptor,
is also a potent inhibitor at a central nAChR. It has little effect on a common
CNS GABAA receptor in a clinically relevant concentration range. Interaction
between ketamine and specific subtypes of nAChRs in the CNS may result in
anesthetic behaviors such as inattention to surgical stimulus and in analgesia.
Thiopental causes minor inhibition at the alpha4beta4 nAChR. Modulation of the
alpha4beta4 nAChR by etomidate is unlikely to be important in anesthesia practice
based on the insensitivity of this receptor to clinically used concentrations.
PMID- 10781290
TI - The action of sevoflurane on vascular smooth muscle of isolated mesenteric
resistance arteries (part 1): role of endothelium.
AB - BACKGROUND: The direct action of sevoflurane on systemic resistance arteries is
not fully understood. METHODS: Isometric force was recorded in isolated rat small
mesenteric arteries. RESULTS: Sevoflurane (2-5%) enhanced contractile response to
norepinephrine only in the presence of endothelium, but inhibited it in its
absence. Sevoflurane still enhanced the norepinephrine response after inhibitions
of the nitric oxide, endothelium-derived hyperpolarizing factor, cyclooxygenase
and lipoxygenase pathways, or after blockade of either endothelin-1 ET-1),
angiotensin-II, or sevotonin receptors. Sevoflurane (3-5%) inhibited contractile
response to potassium chloride only in the absence of endothelium but did not
influence it in its presence. In the endothelium-intact strips, inhibition of the
norepinephrine response, which was enhanced during application of sevoflurane,
was observed after washout of sevoflurane and persisted for approximately 15 min.
In the endothelium-denuded strips, the inhibition of norepinephrine response was
similarly prolonged after washout of sevoflurane. However, no significant
inhibitions of potassium chloride response were observed after washout of
sevoflurane in both the endothelium-intact and the endothelium-denuded strips.
CONCLUSIONS: The action of sevoflurane on norepinephrine contractile response
consists of endothelium-dependent vasoconstricting and endothelium-independent
vasodilating components. In the presence of endothelium, the former predominates
over the latter, enhancing the norepinephrine response. The endothelium
independent component persisted after washout of sevoflurane, leading to
prolonged inhibition of the norepinephrine response. The mechanisms behind the
sevoflurane-induced inhibition of norepinephrine response are at least in part
different from those behind its inhibition of potassium chloride response. Nitric
oxide, endothelium-derived hyperpolarizing factor, cyclooxygenase products,
lipoxygenase products, endothelin-1, angiotensin-II, and serotonin are not
involved in the vasoconstricting action. (Key words: Halogenated volatile
anesthetics; sympathetic nervous system; systemic hypotension; vascular
endothelium.)
PMID- 10781291
TI - The action of sevoflurane on vascular smooth muscle of isolated mesenteric
resistance arteries (part 2): mechanisms of endothelium-independent
vasorelaxation.
AB - BACKGROUND: The precise mechanisms behind the direct inhibitory action of
sevoflurane on vascular smooth muscle have not been fully elucidated. METHODS:
Endothelium-denuded smooth muscle strips were prepared from rat small mesenteric
arteries. Isometric force and intracellular Ca2+ concentration ([Ca2+]i) were
measured simultaneously in the fura-2-loaded strips. In another series of
experiments, only isometric force was measured in the beta-escin-membrane
permeabilized strips. RESULTS: Sevoflurane (3-5%) inhibited the increases in both
the [Ca2+]i and the force induced by either norepinephrine (0.5-10 microm) or 40
mm K+. Sevoflurane still inhibited the increase in [Ca2+]i induced by
norepinephrine after depletion of intracellular Ca2+ stores with ionomycin,
although it little influenced the increase in [Ca2+]i induced by norepinephrine
after treatment with verapamil. In the fura-2-loaded membrane-intact muscle,
sevoflurane caused a rightward shift of Ca2+-force relation during force
development to stepwise increment of extracellular Ca2+ concentration during 40
mm K+ depolarization in either the presence or the absence of norepinephrine. In
contrast, sevoflurane did not influence Ca2+-activated contraction in the beta
escin-permeabilized muscle, in which alpha-adrenergic receptor coupling was not
retained. CONCLUSIONS: The inhibitory effects of sevoflurane on both
norepinephrine- and potassium chloride (KCl)-induced contractions are caused by
reduction of [Ca2+]i in vascular smooth muscle and inhibition of the myofilament
Ca2+ sensitivity. The [Ca2+]i-reducing effect of sevoflurane observed in both the
norepinephrine- and the K+-stimulated muscle is mainly caused by inhibition of
voltage-gated Ca2+ influx. The inhibitory effect of sevoflurane on Ca2+
activation of contractile proteins seems to be mediated by the cell membrane or
by some diffusible substances that are lost in the beta-escin-permeabilized
cells.
PMID- 10781293
TI - Preventing postoperative pulmonary complications: the role of the
anesthesiologist.
PMID- 10781292
TI - Surgeon and type of anesthesia predict variability in surgical procedure times.
AB - BACKGROUND: Variability in surgical procedure times increases the cost of
healthcare delivery by increasing both the underutilization and overutilization
of expensive surgical resources. To reduce variability in surgical procedure
times, we must identify and study its sources. METHODS: Our data set consisted of
all surgeries performed over a 7-yr period at a large teaching hospital,
resulting in 46,322 surgical cases. To study factors associated with variability
in surgical procedure times, data mining techniques were used to segment and
focus the data so that the analyses would be both technically and intellectually
feasible. The data were subdivided into 40 representative segments of manageable
size and variability based on headers adopted from the common procedural
terminology classification. Each data segment was then analyzed using a main
effects linear model to identify and quantify specific sources of variability in
surgical procedure times. RESULTS: The single most important source of
variability in surgical procedure times was surgeon effect. Type of anesthesia,
age, gender, and American Society of Anesthesiologists risk class were additional
sources of variability. Intrinsic case-specific variability, unexplained by any
of the preceding factors, was found to be highest for shorter surgeries relative
to longer procedures. Variability in procedure times among surgeons was a
multiplicative function (proportionate to time) of surgical time and total
procedure time, such that as procedure times increased, variability in surgeons'
surgical time increased proportionately. CONCLUSIONS: Surgeon-specific
variability should be considered when building scheduling heuristics for longer
surgeries. Results concerning variability in surgical procedure times due to
factors such as type of anesthesia, age, gender, and American Society of
Anesthesiologists risk class may be extrapolated to scheduling in other
institutions, although specifics on individual surgeons may not. This research
identifies factors associated with variability in surgical procedure times,
knowledge of which may ultimately be used to improve surgical scheduling and
operating room utilization.
PMID- 10781294
TI - Insidious intoxication after morphine treatment in renal failure: delayed onset
of morphine-6-glucuronide action.
PMID- 10781295
TI - Dilated nonreactive pupils secondary to neuromuscular blockade.
PMID- 10781296
TI - Massive hemoptysis after the initiation of positive pressure ventilation in a
patient with pulmonary tuberculosis.
PMID- 10781297
TI - Thoracic epidural anesthesia for thoracoscopy, rib resection, and thoracotomy in
a patient with a bronchopleural fistula postpneumonectomy.
PMID- 10781298
TI - Electromyographic activity falsely elevates the bispectral index.
PMID- 10781299
TI - Vasoconstrictive versus vasodilatory effects of alpha-2 adrenergic agonists on
the spinal microcirculation.
PMID- 10781300
TI - Bias in a further model for predicting PONV may not advance current knowledge.
PMID- 10781301
TI - Perturbation of lipid and protein structure by general anesthetics: how little is
too little?
PMID- 10781302
TI - Is the system at fault, or its players?
PMID- 10781303
TI - The purpose of peer review.
PMID- 10781304
TI - Postoperative metastasis risk: more than immunosuppression.
PMID- 10781305
TI - Does perioperative antithrombotic therapy increase the likelihood of a
postoperative coagulopathy after cardiac surgery?
PMID- 10781306
TI - Inadvertent misconnection of the scavenger hose: A cause for increased pressure
in the breathing circuit.
PMID- 10781307
TI - Use of esophageal stethoscope as an introducer during nasotracheal intubation.
PMID- 10781308
TI - Preparation for nasotracheal intubation.
PMID- 10781309
TI - Middle turbinectomy: A complication of IMPROPER nasal intubation?
PMID- 10781310
TI - A linguistic crisis? Maybe. A linguistic crises? Definitely not!
PMID- 10781311
TI - Arytenoid subluxation caused by laryngoscopy and intubation.
PMID- 10781312
TI - Potency of cisatracurium: a correction.
PMID- 10781313
TI - A simple towel headrest for infants and children.
PMID- 10781315
TI - Author correction
PMID- 10781314
TI - Radial to femoral arterial pressure gradient from massive ascites.
PMID- 10781316
TI - Pyrazoline reception: a possible role of opioid receptors of sensory neurons.
PMID- 10781317
TI - Generation of the semantic content of an utterance in patients with focal lesions
in the frontal and occipital areas of the right and left hemispheres.
PMID- 10781318
TI - Hearing characteristics of the harbor porpoise Phocoena phocoena.
PMID- 10781319
TI - Decreased concentration of high-energy phosphates prevents a decrease in redox
potential of skeletal muscles under gravitational unloading.
PMID- 10781320
TI - Caffeine effect on the cholinergic postsynaptic membrane of a mouse neuromuscular
synapse.
PMID- 10781321
TI - Effects of intranasal administration of pineal-gland peptides on aggressive
defensive behavior of unilaterally adrenalectomized rats.
PMID- 10781322
TI - The role of calcium binding to the external membrane in the regulation of electro
mechanical connection in early myogenesis.
PMID- 10781323
TI - Changes in optical spectra of gamma-globulin and possible mechanisms of its
physiological effects in organisms exposed to gamma-radiation.
PMID- 10781324
TI - Transitive inference in hooded crows: preliminary data.
PMID- 10781326
TI - Effects of dermorphin and its analogues on spontaneous behavior in white rats.
PMID- 10781325
TI - Ultrastructural study of the endoplasmic reticulum in Mauthner cells of fish
after fatigue and restoration of the function.
PMID- 10781327
TI - Effect of ambient pressure on the membrane state and liver cytochrome P450
activity in a series of vertebrates.
PMID- 10781328
TI - Heterosis as the cause of the secular trend in humans.
PMID- 10781329
TI - The vole species Microtus arvalis and Microtus rossiaemeridionalis in the Urals:
hybridization in the wild.
PMID- 10781330
TI - Vertical and geographical distribution patterns of vestimentiferans (Pogonophora,
Vestimentifera).
PMID- 10781331
TI - Theriological survey along the Northern Sea Route in 1999.
PMID- 10781332
TI - Specific features of roach (Rutilus rutilus L.) behavior in the turbulence
intensity gradient over the flow depth.
PMID- 10781333
TI - Mechanism of formation of chimeric mobile elements responsible for the extremely
unstable mutations in Drosophila melanogaster.
PMID- 10781334
TI - Spine architectonics in some rodents (Rodentia: Myomorpha, Hystricomorpha).
PMID- 10781335
TI - Ecological and geographical aspects of the plague agent Yersinia pestis
speciation.
PMID- 10781336
TI - Ecological mechanisms of soil biota tolerance to metal contamination.
PMID- 10781337
TI - Comparative characteristics of the muscular tissue in bony fishes with different
nutrition types.
PMID- 10781338
TI - Genomic organization of the mouse ubi-d4/requiem gene.
PMID- 10781339
TI - An experience of compilation of a database on plankton studies in the arctic
basin.
PMID- 10781340
TI - Characteristics of microevolution in the polymorphic species Archips podana Scop.
(Lepidoptera: Tortricidae).
PMID- 10781341
TI - The abundance-size relationship in crustaceans from the order Euphausiacea.
PMID- 10781342
TI - Characteristics of lipids from green alga Botryococcus braunii synthesizing
liquid hydrocarbons.
PMID- 10781343
TI - Nonmonotonic changes of lipid metabolism in thymocyte nuclei of rats exposed to
chronic gamma-radiation.
PMID- 10781344
TI - The right atrial/transoesophagael approach for conversion of atrial fibrillation:
a hybrid method for compromise?
PMID- 10781345
TI - The unresolved mystery of stress-induced ST segment elevation after myocardial
infarction.
PMID- 10781346
TI - Diabetes, coronary heart disease and sulphonylureas-not the final word.
PMID- 10781347
TI - Should we transfer patients with acute myocardial infarction to a tertiary care
hospital for primary angioplasty?
PMID- 10781348
TI - Obesity, Cinderella of CHD risk factors.
PMID- 10781349
TI - The optimal management of cardioversion of atrial fibrillation or flutter: still
a 'stunning' problem.
PMID- 10781350
TI - Troponins in pericarditis: implications for diagnosis and management of chest
pains patients.
PMID- 10781351
TI - Clinical developments in cardiac activation mapping.
PMID- 10781352
TI - Overweight and obesity: a major challenge for coronary heart disease secondary
prevention in clinical practice in Europe.
AB - AIMS: To evaluate the management of overweight and obesity in coronary artery
disease patients in Europe. METHODS AND RESULTS: The EUROASPIRE Study is a
multicentre epidemiological study involving nine European countries. The major
cardiovascular risk factors and their management were collected from hospital
records and measured at least 6 months after hospitalization during a specific
interview. A total of 4863 consecutive records from men and women with coronary
artery disease, under 71 years of age, were reviewed. Interviews were obtained
for 3569 (73%). Body mass index was computed from height and weight noted in the
medical records and measured at interview. Management of overweight and obesity
was recorded at interview. At least 6 months after hospitalization, 75% of women
and 80% of men were overweight and 33% of women and 23% of men were obese. Height
noted in medical records was over-estimated, inducing an under-estimation of
obesity in 16% of men and 33% of women. Advice from a nutritionist was offered in
less than 20% of obese patients. The same trends were observed in all
participating countries. CONCLUSIONS: Prevalences of overweight and obesity are
high in coronary artery disease patients in Europe. A systematic measurement of
height and weight is a prerequisite to a better management of this common
modifiable risk factor.
PMID- 10781353
TI - Dobutamine- vs exercise-induced ST segment elevation early after Q wave
myocardial infarction. Prediction of functional recovery after revascularization.
AB - AIMS: The association between stress-induced ST elevation and functional recovery
following revascularization after myocardial infarction remains unclear. We
assessed the relative accuracy of dobutamine- and exercise-induced ST elevation
in Q wave leads in predicting functional recovery following revascularization,
and we investigated the relationship of ST elevation to different wall motion
responses to dobutamine. METHODS AND RESULTS: Thirty-nine patients underwent
dobutamine stress echo and exercise test 8+/-2 days after Q wave myocardial
infarction. All patients underwent angiography and subsequent revascularization.
Follow-up echocardiograms were obtained 7+/-4 weeks after revascularization.
Functional recovery was assessed by the difference between the baseline and the
follow-up asynergy index. Nineteen patients (48%) developed dobutamine- and
exercise-induced ST elevation. There was significant agreement between the tests
(k=0.58, P<0.001). We found a significant correlation between dobutamine and
exercise-induced ST elevation with functional recovery following
revascularization (r=0. 45, P<0.005 and r=0.7, P<0.001, respectively). The
parameters with the highest predictive value for functional recovery were: (a)
the biphasic response during dobutamine infusion, (b) the development of ST
elevation in both tests, and (c) the development of exercise-induced ST elevation
in more than three leads. CONCLUSION: There is a strong association between
dobutamine- and exercise-induced ST elevation with functional recovery following
revascularization. Exercise-induced ST elevation in more than three leads and a
biphasic response during dobutamine infusion accurately predict functional
recovery.
PMID- 10781354
TI - Multicentre randomized trial comparing transport to primary angioplasty vs
immediate thrombolysis vs combined strategy for patients with acute myocardial
infarction presenting to a community hospital without a catheterization
laboratory. The PRAGUE study.
AB - BACKGROUND: Primary coronary angioplasty is an effective reperfusion strategy in
acute myocardial infarction. However, its availability is limited, and
transporting patients to an angioplasty centre in the acute phase of myocardial
infarction has not yet been proved safe. METHODS: The PRAGUE study (PRimary
Angioplasty in patients transferred from General community hospitals to
specialized PTCA Units with or without Emergency thrombolysis) compared three
reperfusion strategies in patients with acute myocardial infarction, presenting
within 6 h of symptom onset at community hospitals without a catheterization
laboratory: group A - thrombolytic therapy in community hospitals (n=99), group B
- thrombolytic therapy during transportation to angioplasty (n=100), group C -
immediate transportation for primary angioplasty without pre-treatment with
thrombolysis (n=101). RESULTS: No complications occurred during transportation in
group C. Two ventricular fibrillations occurred during transportation in group B.
Median admission-reperfusion time in transported patients (group B 106 min, group
C 96 min) compared favourably with the anticipated >90 min in group A. The
combined primary end-point (death/reinfarction/stroke at 30 days) was less
frequent in group C (8%) compared to groups B (15%) and A (23%, P<0. 02). The
incidence of reinfarction was markedly reduced by transport to primary
angioplasty (1% in group C vs 7% in group B vs 10% in group A, P<0.03).
CONCLUSIONS: Transferring patients from community hospitals to a tertiary
angioplasty centre in the acute phase of myocardial infarction is feasible and
safe. This strategy is associated with a significant reduction in the incidence
of reinfarction and the combined clinical end-point of death/reinfarction/stroke
at 30 days when compared to standard thrombolytic therapy at the community
hospital.
PMID- 10781355
TI - Serum cardiac troponin I and ST-segment elevation in patients with acute
pericarditis.
AB - OBJECTIVE: ST-segment elevation in acute pericarditis is believed to be caused by
superficial myocardial inflammation or epicardial injury. We used cardiac
troponin I, a sensitive and specific marker of myocardial injury, to assess
myocardial lesions in idiopathic acute pericarditis and its relationship to ST
segment elevation. PATIENTS AND METHODS: Sixty-nine consecutive patients (53 men,
48+/-17 years) with idiopathic acute pericarditis were included. We used an
enzymoimmunoflurometric method to measure serum cardiac troponin I on admission
(myocardial infarction threshold was 1.5 ng. ml(-1)). RESULTS: Cardiac troponin I
was detectable in 34 patients (49%) and was beyond the 1.5 ng. ml(-1)threshold in
15 (22%). Coronary angiography performed in seven of these 15 patients was normal
in all of them. ST-segment elevation was observed in 93% of the patients with
cardiac troponin I >1.5 ng. ml(-1)vs 57% of those without (P<0.01). Sensitivity
of ST-segment elevation to detect myocardial injury was 93% and specificity 43%.
Patients with a cardiac troponin I increase higher than 1.5 ng. ml(-1)were more
likely to have had a recent infection (66% vs 31%;P=0.01) and were younger (37+/
14 vs 52+/-16 years;P=0.002). There was no significant relationship with other
parameters such as pericardial friction rub, fever, PR segment abnormalities,
echocardiographic findings or C-reactive protein. CONCLUSION: In patients with
idiopathic acute pericarditis, an increase in cardiac troponin I is frequently
observed, especially in younger patients and those with a recent infection.
Although ST-segment elevation does not reliably indicate myocardial injury, a
significant cardiac troponin I increase is only seen in these patients.
PMID- 10781356
TI - Transoesophageal echocardiography-guided cardioversion of atrial fibrillation or
flutter. Selection of a low-risk group for immediate cardioversion.
AB - AIMS: Despite exclusion of left atrial thrombi by transoesophageal
echocardiography, cardioversion-related thromboembolism has been reported in
atrial fibrillation or flutter. To define a low-risk group for cardioversion
without previous anticoagulation, patients were selected for immediate
cardioversion if there were no thrombi, no echo spontaneous contrast and the
outflow velocity of the left atrial appendage was greater than 0.25 m. s(-1)on
transoesophageal echocardiography. METHODS AND RESULTS: Two hundred and forty-two
consecutive patients referred for cardioversion of atrial fibrillation or flutter
with a duration of more than 2 days and no anticoagulation therapy were examined
with transoesophageal echocardiography. After the transoesophageal
echocardiography examination, patients who were eligible for immediate
cardioversion were anticoagulated with low molecular weight heparin (dalteparin)
subcutaneously, together with warfarin prior to cardioversion. Dalteparin
treatment was continued until the patient had reached therapeutic prothrombin
values. Based on the transoesophageal echocardiographic findings the patients
were divided into two groups: immediate cardioversion, group A, with a mean age
of 62+/-13 years (n=162); or conventional warfarin treatment before
cardioversion, group B, with a mean age of 67+/-10 years (P<0.05) (n=80). In
group A, lone atrial fibrillation or flutter was more common (53%; 95% CI: 45-61)
compared to group B (34%; 95% CI: 23-44, P<0.05), while heart disease was more
common in group B (45%; 95% CI: 34-56) compared to group A (31%; 95% CI: 24-39,
P<0.05). Echocardiography revealed thrombi in 5% (95% CI: 2.6-8) of the patients,
left atrial size was larger, fractional shortening lower, and a higher proportion
had impaired left ventricular function in group B. No thromboembolic event
occurred at or after cardioversion in any of the patients; however, before
planned cardioversion one transitory ischaemic attack, one lethal stroke and one
cardiac death occurred in three of the patients with thrombi despite warfarin
therapy. One-month follow-up maintenance of sinus rhythm was 75% in group A
compared to 45% in group B (P<0.01). CONCLUSION: After using our transoesophageal
echocardiographic exclusion criteria (no thrombi, no spontaneous echo contrast
and left atrial appendage outflow velocity > or = 25 m. s(-1)) cardioversion can
safely be performed in 2/3 of patients with atrial fibrillation or flutter
without previous anticoagulation therapy. These patients maintained sinus rhythm
significantly better after 1 month compared to patients with prolonged warfarin
therapy before cardioversion.
PMID- 10781357
TI - Transoesophageal low-energy cardioversion of atrial fibrillation. Results with
the oesophageal-right atrial lead configuration.
AB - BACKGROUND: Low energy internal cardioversion is a safe and effective procedure
to restore sinus rhythm in patients with atrial fibrillation refractory to
external cardioversion. However the procedure is invasive and fluoroscopy is
mandatory. Aim of the study To assess the efficacy, safety and tolerability of a
new simplified procedure of low energy internal cardioversion. METHODS: Twenty
five consecutive patients (19 males and 6 females) with persistent atrial
fibrillation were submitted to low energy internal cardioversion using a step-up
protocol (in steps of 50 V, starting from 300 V). A large surface area lead
(cathode) was positioned in the oesophagus, 45 cm from the nasal orifice. A
second large surface area lead (anode) was positioned in the right atrium. A
quadripolar lead was positioned at the right ventricular apex to achieve
ventricular synchronization and back-up pacing. Oesophageal endoscopy was
performed within 24 h of the end of the procedure and repeated after 48 h, if
injury to the oesophageal mucosa had occurred. RESULTS: Sinus rhythm was restored
in 23 patients (92%) with a mean delivered energy of 15.74 J (range 5-27) and a
mean impedance of 48 Omega. In two patients, endoscopy revealed that small burns
had occurred in the oesophageal mucosa. Such lesions spontaneously healed after
48 h. CONCLUSIONS: This new technique of performing low energy internal
cardioversion is effective and safe and avoids the positioning of a lead in the
coronary sinus or in the left pulmonary artery, thereby simplifying the
procedure.
PMID- 10781358
TI - Nitric oxide synthase in CHF.
PMID- 10781359
TI - Classification of acute MI.
PMID- 10781360
TI - A reply
PMID- 10781361
TI - Digoxin and mortality in idiopathic dilated cardiomyopathy.
PMID- 10781362
TI - A reply
PMID- 10781363
TI - Stress echo training - need for a better gold standard: the invasive viewpoint.
PMID- 10781365
TI - ESC news and appointments
PMID- 10781364
TI - Cardiac rehabilitation.
PMID- 10781366
TI - Association of Academic Surgery presidential address: an attitude of gratitude.
PMID- 10781367
TI - AcademicSurgery@Leadership.you.
PMID- 10781368
TI - The outcome of research training during surgical residency.
AB - BACKGROUND/PURPOSE: Graduates of a university surgical residency program were
surveyed to identify the timing of specialty selection and the impact that
studying in a research laboratory had on subsequent acceptance into a fellowship
program. METHODS: Between 1975 and 1990, 86 residents completed general surgery
training at UCLA Medical Center. A survey was sent to all graduates to determine
the focus of their previous laboratory research and when they selected their
eventual surgical specialty. Responses were received from 67 of the 86 graduates
(78%). RESULTS: Forty-eight of the sixty-seven respondents (72%) took one or more
years of surgical research during residency. Postresidency fellowship training
was selected by 55 of 67 (82%); 50 applied to fewer than five programs; 49 of 55
(89%) received one of their top three choices. Twenty-seven of the sixty-seven
residents pursued an academic career (40%). Residents who performed at least 2
years of research were more likely to become academicians (53%) than residents
who did 1 year or less of research (22%). Only 39 of 67 residents (58%) had
selected a specialty after 2 years of clinical training; 28 more made the
selection after the third clinical year. All residents interested in cardiac
surgery (n = 18) or plastic surgery (n = 4) prior to research were accepted into
fellowships in those specialities, whereas only 37% of those who had an interest
in other fields pursued the same specialty (P < 0.0001). Residents performing
research in general surgery (n = 9), surgical oncology (n = 18), cardiac surgery
(n = 14), and plastic surgery (n = 3) were more likely to practice in that
specialty than those doing research in other specialty laboratories. CONCLUSIONS:
General surgery residents performing research in a specialty laboratory are
likely to pursue fellowship training relating to that field. Those who select a
career in cardiac or plastic surgery prior to research are most likely to enter
into these fields as their eventual specialty. Residents who perform 2 or more
years of laboratory research publish more papers and often pursue an academic
career.
PMID- 10781369
TI - Signaling mechanisms of glucagon-like peptide 2-induced intestinal epithelial
cell proliferation.
AB - BACKGROUND: Glucagon-like peptide 2 (GLP-2) stimulates intestinal epithelial
growth with high potency and specificity. However, the intracellular signaling
pathways responsible for the growth-stimulatory action of GLP-2 are not clearly
understood. Here we report possible signaling pathways mediating GLP-2's
proliferative actions in the human intestinal epithelial cell line Caco-2.
MATERIALS AND METHODS: Caco-2 cells were subcultured under serum-deprived
conditions in the presence or absence of GLP-2 (10 microM) and varying
concentrations of inhibitors of three candidate kinases: genistein, a global
tyrosine kinase inhibitor; LY294002, a phosphatidylinositide (PI) 3-kinase
inhibitor; and PD 098059, a mitogen-activated/extracellular signal-regulated
kinase (MEK) inhibitor. Proliferation was assessed using [(3)H]thymidine
incorporation. Relative abundance of the phosphorylated forms of two specific
mitogen-activated protein kinases (MAPKs), ERK1 and ERK2, was assessed by Western
blotting. RESULTS: GLP-2-treated cells demonstrated a greater than 10-fold
increase in proliferation. This response was inhibited by genistein, LY294002,
and PD 098059 in a dose-dependent fashion. A significantly greater abundance of
the phosphorylated forms of both ERK-1 and ERK-2 was present in cells within 5
min of treatment with GLP-2. CONCLUSIONS: GLP-2 stimulates the proliferation of
Caco-2 cells in vitro. This increase in Caco-2 proliferation in response to GLP-2
may be due, at least in part, to the involvement of both the PI 3-kinase and the
MAPK pathways.
PMID- 10781370
TI - Isolated hepatic cholinergic denervation impairs glucose and glycogen metabolism.
AB - BACKGROUND: Hepatic innervation plays an essential role in insulin extraction and
glucose production, but the specific role of hepatic cholinergic innervation
remains unclear. We sought to establish a model of isolated hepatic cholinergic
denervation (IHCD), and to assess whether glycogen storage or the control of net
hepatic glucose production (HGP) was altered by IHCD. MATERIALS AND METHODS:
Sprague-Dawley rats underwent either hepatic vagotomy or sham operation. Liver
tissue was stained for vesicular acetylcholine transporter (VAChT) and
(nonspecific neural) protein gene product 9. 5 (PGP) for verification of IHCD.
Liver glycogen content was quantified in fed and fasted IHCD or sham-operated
animals. HGP was determined after single-pass isolated liver perfusion, during
which a 30-min 12 ng/ml glucagon infusion was begun after equilibration, and
after 10 min, a 200 microU/ml insulin infusion was added. RESULTS: Uniform
staining of PGP and absence of VAChT staining in hepatic vagotomized rats
demonstrated the validity of our model. Glycogen content of sham-operated livers
(n = 8) increased from 6.0 +/- 1.7 in the fasting state to 10.6 +/- 1.8 mg/g
liver, after feeding (P < 0.05). IHCD livers (n = 8) showed no comparable
increase (3.5 +/- 0.6 to 4.0 +/- 0.7 mg/g liver). Perfusion with glucagon alone
resulted in less HGP in IHCD livers (n = 12) compared with sham-operated livers
(n = 10) (integrated HGP 3.3 +/- 0.3 mg/g liver min(-1) vs 5.1 +/- 0.5 mg/g liver
min(-1), P < 0.05). Insulin infusion revealed impaired responsiveness to insulin
after IHCD; the ratio of HGP in the final 10 min of perfusion (glucagon and
insulin) to HGP in the initial 10 min (glucagon alone) was 90.3 +/- 2.4% for IHCD
livers versus 68.1 +/- 4.4% for sham-operated controls, respectively (P =
0.0002). CONCLUSIONS: Our study shows that IHCD results in significant impairment
in liver glycogen storage and impaired hepatic sensitivity to glucagon and,
possibly, to insulin. We conclude that hepatic cholinergic integrity is essential
to normal hepatic glucose metabolism.
PMID- 10781371
TI - Iron deficiency diminishes gallbladder neuronal nitric oxide synthase.
AB - BACKGROUND: Iron deficiency has been demonstrated in the prairie dog to result in
cholesterol crystal formation and altered biliary motility. Gallbladder filling
and emptying are influenced by both inhibitory and excitatory stimuli, with
nitric oxide (NO) playing a key role in normal relaxation. Iron is a cofactor for
nitric oxide synthase. Therefore, we tested the hypothesis that iron deficiency
would result in diminished levels of gallbladder neuronal nitric oxide synthase
(nNOS) but would not influence the gallbladder's response to excitatory stimuli.
MATERIALS AND METHODS: Twenty adult female prairie dogs were fed either an iron
supplemented (Fe(+)) (200 ppm) control diet (n = 10) or an iron-deficient (Fe-)
(8 ppm) diet (n = 10) for 8 weeks. Fasting gallbladder volume was measured.
Gallbladder muscle strips were harvested for response to excitatory stimuli and
measurement of nNOS protein levels by Western blotting. Muscle strip response to
a spectrum of doses of cholecystokinin, acetylcholine, and electrical field
stimuli was determined, and the areas under the response curves were calculated.
RESULTS: Gallbladder volume increased in the iron-deficient prairie dogs compared
with the iron-supplemented group (1.45 +/- 0.27 mL vs 0.80 +/- 0.13 mL, P <
0.05). Iron deficiency diminished the ratio of gallbladder nNOS to beta-actin
protein levels (0.05 +/- 0.01 vs 3.48 +/- 1.02, P < 0.05) but resulted in a
normal response to excitatory stimuli. CONCLUSIONS: We conclude that diminished
gallbladder neuronal nitric oxide synthase contributes to the gallbladder stasis
that occurs with iron deficiency. This phenomenon may contribute to the increased
incidence of gallstones in premenopausal women.
PMID- 10781373
TI - Pancreatic cancer cell proliferation is phosphatidylinositol 3-kinase dependent.
AB - BACKGROUND: Genetic mutations found in pancreatic cancer (K-ras, p16, p53) lead
to inappropriate cellular proliferation. Mitogens stimulate proliferation via the
phosphatidylinositol 3-kinase (PI3K)- and/or the p44/42-mitogen-activated protein
kinase [p44/42-MAPK or extracellular signal-regulated kinase (ERK)] signaling
pathways. We examined whether inhibition of either PI3K or ERK could limit
proliferation in human pancreatic cancer. METHODS: Proliferation was stimulated
in quiescent human pancreatic cancer cell lines (BxPC3 and Panc-1) by 10% fetal
calf serum (FCS). In certain samples, PD98059 (an ERK inhibitor) or LY294002 (a
PI3K inhibitor) was also added. AKT phosphorylation (indicating PI3K activity)
and ERK phosphorylation (ERK activation) were determined by Western blot. Cell
viability was determined by MTT assay. Cell cycle progression and apoptosis were
determined by flow cytometry. A two-tailed t test was used for statistical
analysis of the data (significance P < 0.05). RESULTS: LY294002 inhibited the
PI3K pathway without affecting ERK activation in response to serum. PD98059
inhibited the ERK pathway specifically. In both BxPC-3 and Panc-1 cell lines,
LY294002 inhibited serum-induced proliferation. This was associated with G(1)
cell cycle arrest and with an increase in the rate of apoptosis. PD98059
inhibited proliferation only in BxPC3 cells, and to a lesser degree than did
LY294002. CONCLUSIONS: PI3K signaling appears to be necessary for G(1)-to-S phase
progression and proliferation in pancreatic cancer cells. ERK plays a lesser role
in mitogen-induced proliferation. Pharmacological inhibition of PI3K may decrease
proliferation, increase apoptosis, and potentially confer therapeutic benefit in
pancreatic cancer.
PMID- 10781372
TI - Neutrophils regulate their own apoptosis via preservation of CXC receptors.
AB - BACKGROUND: Dysregulated neutrophil (PMN) apoptosis is thought to contribute to
an exaggerated inflammatory response in diseases such as acute respiratory
distress syndrome (ARDS) and multiple organ dysfunction syndrome (MODS). The CXC
chemokines, interleukin-8 (IL-8) and growth-related oncogene alpha (Gro-alpha),
contribute to the inflammatory response and suppress PMN apoptosis. We
hypothesized that PMN generation of CXC chemokines is an autocrine/paracrine
mechanism for amplification of the PMN inflammatory response via suppression of
apoptosis. METHODS: Freshly isolated human PMNs from healthy donors were
incubated with IL-8 or Gro-alpha (100 ng/ml) for 0-12 h, and apoptosis was
analyzed at 24 h. De novo synthesis of IL-8 or Gro-alpha was measured using an
ELISA. To determine if receptors were available to bind these newly synthesized
ligands (125)I radiolabeled monoclonal antibodies specific for each receptor
(CXCRI, CXCRII) were used to determine PMN receptor density. Comparison was by
one-way ANOVA. RESULTS: Significant suppression of apoptosis was seen at 24 h
with only 4 h exposure to IL-8 or Gro-alpha (n = 5, P < 0.05). PMNs cultured with
IL-8 for 4 h produced 31 +/- 4.3 ng/ml IL-8 by 24 h; PMNs cultured with Gro-alpha
produced 19.7 +/- 4.0 ng/ml Gro-alpha (n = 6, P < 0. 05). Neither chemokine
induced significant production of the other chemokine. The addition of either
ligand promoted upregulation of CXCR1 (n = 4, P < 0.05) at 24 h. However, CXCR2
was downregulated by Gro-alpha and IL-8 to 71 +/- 7.5 and 79 +/- 6.3% of control,
respectively (P < 0.05). CONCLUSION: IL-8 and Gro-alpha, which suppress
apoptosis, stimulate their own production after short-term incubation with PMNs.
PMNs maintain the ability to respond to these chemokines through expression of
the CXC receptors which suggests that PMNs are active participants in the
suppression of apoptosis at inflammatory sites. CXCRI remains upregulated after
prolonged stimulation and may be an important target for mediating neutrophil
responses to IL-8.
PMID- 10781374
TI - p21 (WAF1/CIP1) is required for the mitogenic response to intestinal resection.
AB - BACKGROUND: Increased enterocyte proliferation and apoptosis characterize the
intestinal adaptive response to massive small bowel resection (SBR). Since p21
(WAF1/CIP1) has been implicated to play a role in cellular differentiation and
apoptosis, this study tested the hypothesis that p21 is obligatory for adaptation
to occur. MATERIALS AND METHODS: p21-null (n = 36) and wild-type (C57B1/6, n =
19) mice underwent a 50% SBR or sham operation. After 3 days, parameters of
adaptation (ileal wet weight, villus/crypt morphology, and ileal protein
content), an enterocyte proliferation index (PI), and an apoptotic index (AI)
were determined in the residual ileum. In a separate set of experiments, p21-null
(n = 11) and control (n = 20) mice underwent the aforementioned operative
procedures and the remnant intestine was subjected to a reverse transcription
polymerase chain reaction for p27 (KIP1). RESULTS: Both AI and PI increased after
SBR in the wild-type mice. In the p21-null mice, SBR increased AI, but did not
affect the PI. After SBR, adaptive parameters increased in the wild-type mice,
but failed to increase in the p21-null mice. The absence of p21 caused a baseline
increase in p27 mRNA, which did not change after SBR. CONCLUSION: p21 appears to
be required to increase enterocyte proliferation and to augment the other
parameters of intestinal adaptation. In the absence of p21, the proliferative and
apoptotic responses to SBR are uncoupled. These results suggest a differential
mechanism for the regulation of enterocyte proliferation and apoptosis in the
adapting intestine.
PMID- 10781375
TI - Inhibition of alveolar neutrophil immigration in endotoxemia is macrophage
inflammatory protein 2 independent.
AB - BACKGROUND: Altered transendothelial migration and delayed apoptosis of
neutrophils (PMN) have been implicated as contributing to infection in patients
with gram-negative sepsis. Macrophage inflammatory protein 2 (MIP-2) signals PMN
immigration and may alter other PMN functions. We tested the hypothesis that
sequential endotoxin challenge in vivo alters PMN apoptosis and chemotactic
responses. MATERIALS AND METHODS: Endotoxemia was induced in male Wistar rats
(250 g) via intraperitoneal (IP) administration of LPS (4 mg/kg). After 18 h,
intratracheal (IT) injection of LPS (400 microg/kg) was performed. Control
animals received saline injections. Four hours after IT-LPS, circulating and
bronchoalveolar lavage (BAL) PMN were isolated. PMN yields were calculated, and
apoptosis was quantified after 18 h in culture by annexin V-fluorescein
isothiocyanate FACS analysis. BAL MIP-2 concentrations were determined by ELISA.
PMN chemotaxis to MIP-2 and IL-8 was determined using a fluorescent in vitro
migration assay. RESULTS: Endotoxemia (IP-LPS) significantly decreases BAL PMN
yield in response to an in vivo IT-LPS challenge. IT-LPS inhibits BAL PMN
apoptosis to the same extent as sequential IP/IT-LPS. Alveolar MIP-2
concentrations are similar in the two groups. In vitro migration to IL-8 and MIP
2 was inhibited in PMN from endotoxemic versus control animals. CONCLUSIONS:
These data demonstrate that endotoxemia inhibits PMN migration despite similar
MIP-2 concentrations in the alveolus. Sequential insults do not affect the
inhibition of apoptosis. In vitro, PMN from endotoxemic animals display impaired
chemotaxis to MIP-2 and interleukin-8. This may result in an inadequate host
defense that contributes to increased ICU-acquired pneumonia in septic patients.
PMID- 10781376
TI - Hypoosmotic stress activates p38, ERK 1 and 2, and SAPK/JNK in rat hepatocytes.
AB - BACKGROUND: Following hepatocyte injury, changes in the perihepatocyte milieu
modulate cell volume and influence growth. Hypoosmotic stress activates nuclear
factor-kappa B (NF-kappaB), a transcription factor believed to prime cell cycle
progression in hepatocytes. In this study, we investigate the role of mitogen
activated protein kinases (MAPKs) in the activation of NF-kappaB. MATERIALS AND
METHODS: Quiescent primary hepatocytes were exposed to hypoosmotic serum-free
William's E (WE) medium (200 mOsm/liter), with or without a 1-h pretreatment with
either PD 98059 (15 microM) or SB 202190 (3 microM). Parallel experiments were
conducted using hepatocyte growth factor (HGF) at 0.1 mg/ml and normoosmotic WE
medium as positive and negative controls, respectively (n = 3). Relative
densitometries of Western blots measured phosphorylated cytoplasmic p38, ERK 1
and 2, and SAPK/JNK. Electromobility shift assays examined nuclear NF-kappaB
activation. RESULTS: (i) Hypoosmolar WE medium phosphorylated p38, ERK 1 and 2,
and SAPK/JNK by 5 min. (ii) Hypoosmolar WE medium activated NF-kappaB at 60 min.
(iii) HGF phosphorylated all three MAPKs and activated NF-kappaB with profiles
similar to those of hypoosmotic stress. (iv) Both PD 98059 and SB 202190
abrogated the activation of NF-kappaB in HGF-stimulated cells but not in
hypoosmotically stressed cells. CONCLUSION: (i) Both hypoosmotic cell swelling
and HGF phosphorylate p38, ERK 1 and 2, and SAPK/JNK, and (ii) HGF, but not
hypoosmotic stress, activates NF-kappaB via p38 and ERK 1 and 2 phosphorylation.
These data suggest that cell swelling activates NF-kappaB through a pathway
separate from that of growth factors.
PMID- 10781377
TI - Role of stasis and oxidative stress in ileal pouch inflammation.
AB - BACKGROUND: Although ileal pouch-anal anastomosis has become the operation of
choice for patients with chronic ulcerative colitis and familial adenomatous
polyposis coli, ileal pouch inflammation or pouchitis remains a significant
postoperative complication. Numerous factors such as fecal stasis have been
implicated in the etiology of pouchitis; however, pouchitis remains poorly
understood due to the lack of a small animal model. One of the primary goals of
this study was to surgically create a reservoir or U-pouch in the ileum of a rat
in which stasis would occur in a manner that was unimpeded by other complicating
factors such as a colectomy. This model would allow investigation of the
hypothesis that intestinal stasis leads to biochemical changes that predispose
the ileal pouch to inflammation and oxidative stress. MATERIALS AND METHODS: A U
pouch was surgically created in the terminal ileum of Lewis rats just proximal to
the ileocecal valve without a colectomy. Stasis was assessed by serial barium
radiographs over 48 h. Thirty days after surgery, mucosa was obtained from the
ileal U-pouches and nonoperated ileum to assess inflammation and neutrophil
infiltration histologically and by measuring myeloperoxidase activity. Oxidative
stress was assessed by measuring 8-isoprostane levels in urine. Once the model
was validated and it was established that stasis and inflammation occurred in the
pouch, either vitamin E or allopurinol was administered for 30 days after which
myeloperoxidase and 8-isoprostane levels were again measured. RESULTS: In our
experimental model, ileal stasis resulted in increases in both mucosal
myeloperoxidase activity and urinary 8-isoprostane levels, suggesting that
oxidative stress was associated with stasis. Thirty-day treatment with vitamin E
or allopurinol reduced ileal myeloperoxidase activity and urinary 8-isoprostane
levels. CONCLUSION: These studies demonstrated that stasis in the ileum occurred
and was associated with neutrophil infiltration and oxidative stress. Antioxidant
treatment reduced the inflammatory response suggesting a role for antioxidant
therapy in the treatment of pouchitis.
PMID- 10781379
TI - Difficulty with negative feedback: face-to-face evaluation of junior medical
student clinical performance results in grade inflation.
AB - HYPOTHESIS: Direct, face-to-face feedback regarding a medical students' clinical
performance will not increase critical, objective analysis of their performance.
METHODS: A new ward evaluation system (NS) was used concurrently with our
standard written ward evaluation system (OS). The two methods were directly
compared using a standard t test. The OS is a subjective written evaluation of
clinical performance, with a summary grade of 1-6 given as a final grade, with 1
= fail and 6 = honors. The NS retains the 1-6 grading scale; however, students
met with individual faculty and residents and received a face-to-face evaluation
of their performance, as well as a written summary. Twenty-four third-year
medical students rotating on general surgery at the University of Michigan
Medical Center participated in the study. RESULTS: There was a significant degree
of grade inflation with the NS, particularly for students with poorer
performance. The average grade using the OS was 5.11 +/- 0. 11; with the NS, the
average grade was 5.62 +/- 0.07 (P < 0.001). If students with grades of 5.0 or
less in the OS are studied, then the average grade using the OS is 4.24 +/- 0.32,
in contrast to 5.47 +/- 0.14 with the NS (P < 0.005). An additional interesting
finding was noted: among the students who failed to participate in the face-to
face interviews (n = 4), the average grade using the OS was 4.36 +/- 0.29 (P <
0.05 vs OS total). CONCLUSIONS: While students desire more timely, direct
feedback on their clinical performance, faculty are poor at giving direct,
objective, face-to-face feedback, particularly when it involves negative
feedback, with resultant grade inflation.
PMID- 10781378
TI - Chlamydia pneumoniae activates nuclear factor kappaB and activator protein 1 in
human vascular smooth muscle and induces cellular proliferation.
AB - BACKGROUND: Observational data strongly suggest an association between Chlamydia
pneumoniae and atherosclerotic cardiovascular disease. However, few studies have
mechanistically linked C. pneumoniae to vascular remodeling. The purpose of the
present study was to examine the mechanistic relationship between C. pneumoniae
and human vascular smooth muscle cell (VSMC) physiology. We sought to determine
the influence of human VSMC infection by C. pneumoniae on (1) VSMC proliferation
and (2) activation of the proinflammatory and proliferative transcription factors
nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1). MATERIALS AND
METHODS: C. pneumoniae was grown and isolated from Hep 2 cells. Human aortic
VSMCs were inoculated with C. pneumoniae in the presence and absence of the
azalide antibiotic azithromycin. Cell proliferation was assayed by direct cell
counting 48 h following infection. Two hours following infection, nuclear
extracts were isolated, and activation of both NF-kappaB and AP-1 was assessed by
electrophoretic mobility shift assay. RESULTS: Compared with control, C.
pneumoniae infection stimulated VSMC proliferation (P < 0.05) and induced both NF
kappaB and AP-1 DNA binding activity. These effects were eliminated by concurrent
treatment with azithromycin. CONCLUSIONS: VSMC infection with C. pneumoniae
activates proliferative intracellular signals and stimulates cell growth. These
data implicate C. pneumoniae as a pathogenic mediator and a potential therapeutic
target in the prevention of atherosclerotic disease.
PMID- 10781380
TI - Effects of intestinal ischemia/reperfusion injury on gastric acid secretion.
AB - BACKGROUND: The mechanism responsible for gastric colonization in critically
injured ICU patients remains to be fully elucidated. Moreover, the effects of gut
ischemia/reperfusion (I/R) injury on gastric function are unclear. It was our
hypothesis that gut I/R injury would cause gastric dysfunction. MATERIALS AND
METHODS: Rats were anesthetized and, via laparotomy, the superior mesenteric
artery (SMA) was clamped at its aortic origin for 45 min followed by clamp
removal. Rats were allowed to awaken and then killed after 6 h of reperfusion.
Control rats underwent laparotomy with SMA isolation. Stomachs were removed,
gastric fluid was aspirated, and the volume, pH, and protein, bicarbonate, and
glucose contents were determined. Serum and antral mucosa were prepared for
gastrin radioimmunoassay and the glandular mucosa was assessed for morphologic
injury. RESULTS: SMA I/R injury caused significant accumulation of gastric
luminal fluid that was alkaline and rich in protein, glucose, and bicarbonate
content when compared with sham controls. SMA I/R injury also caused gastric
surface epithelial cell injury and significantly increased serum and antral
gastrin levels. In additional rats, gut I/R injury inhibited basal acid secretion
and blunted the acid secretory response to pentagastrin. CONCLUSIONS: This study
demonstrated for the first time that small intestinal I/R injury causes
significant gastric dysfunction. The findings suggest that this type of injury, a
frequent occurrence in critically injured ICU patients, may predispose patients
to gastric colonization due to stasis and loss of the natural bactericidal
effects of gastric acid.
PMID- 10781381
TI - S-Nitrosothiols: a class of nitric oxide-donor drugs.
AB - Nitric oxide (NO) was originally described as the principal endothelium-derived
relaxing factor, but it is now known to subserve a variety of functions
throughout the body, both physiological and pathophysiological. NO-donor drugs
decompose in the body, by a variety of mechanisms, to generate NO. Such drugs
have been used for many years in cardiovascular therapeutics, in particular the
organic nitrates for the prevention and treatment of angina pectoris and sodium
nitroprusside for the treatment of hypertensive emergencies. However, patients
taking long-term nitrates often develop tolerance, and prolonged nitroprusside
administration can give rise to cyanide accumulation in the body. Newer NO-donor
drugs, in particular the S-nitrosothiols, offer advantages over the existing
drugs, since they do not share these drawbacks, and initial small clinical
studies suggest that they may be of benefit in a variety of cardiovascular
disorders. Here we briefly review the chemistry and physiology of NO, and discuss
the chemistry and clinical possibilities of the S-nitrosothiols.
PMID- 10781382
TI - Plasma soluble adhesion molecules and endothelium-dependent vasodilation in early
human atherosclerosis.
AB - Levels of soluble cellular adhesion molecules are increased in patients with
atherosclerosis, and have been found to predict coronary heart disease. Therefore
these molecules have been suggested to represent laboratory markers for
inflammation and activation of endothelial cells. Impaired endothelium-dependent
vasodilation has been demonstrated to be an early marker of atherosclerosis. We
hypothesized that soluble adhesion molecules are related to impaired endothelium
dependent vasodilation and may serve as an early marker of atherosclerosis.
Patients (n=52) with moderate and uncomplicated hypercholesterolaemia [low
density lipoprotein (LDL)-cholesterol 4.89+/-1.26 mmol/l] were compared with
healthy controls (n=43; LDL-cholesterol 2.44+/-0.79 mmol/l). Endothelium
dependent vasodilation of the forearm vasculature was assessed by intra-arterial
infusion of acetylcholine (12 and 48 microg/min). Forearm blood flow was measured
by venous occlusion plethysmography. Plasma concentrations of the soluble forms
of ICAM-1 (intercellular cell adhesion molecule-1), VCAM-1 (vascular cell
adhesion molecule-1) and E-selectin were measured by ELISA. Hypercholesterolaemic
patients had impaired endothelium-dependent vasodilation in comparison with
healthy controls (forearm blood flow after 48 microg/min acetylcholine: 21.3+/
10.6 and 30.4+/-16.3 ml. min(-1).100 ml(-1) respectively; P=0.002). Plasma
concentrations of soluble adhesion molecules were not different between
hypercholesterolaemic patients and controls (ICAM-1, 196+/-56 and 180+/-38 ng/ml
respectively; VCAM-1, 431+/-137 and 405+/-65 ng/ml respectively; E-selectin, 39+/
17 and 37+/-12 ng/ml respectively). Moreover, levels of soluble adhesion
molecules were not correlated with endothelium-dependent vasodilation. Thus, in
hypercholesterolaemic patients without clinical atherosclerosis, levels of
soluble adhesion molecules were not elevated in comparison with healthy controls.
In addition, these markers of endothelial inflammation were not related to
impaired endothelium-dependent vasodilation. Our data indicate that measurement
of levels of soluble adhesion molecules cannot replace assessment of endothelium
dependent vasodilation in detection of early hypercholesterolaemic
atherosclerosis.
PMID- 10781383
TI - Endothelial dysfunction as a possible link between C-reactive protein levels and
cardiovascular disease.
AB - Low-grade chronic inflammation, characterized by elevated plasma concentrations
of C-reactive protein (CRP), is associated with an increased risk of
atherosclerotic cardiovascular disease. Endothelial cell activation is an early
event in atherogenesis, and previous studies have reported correlations between
indirect markers of endothelial cell activation and CRP concentration. Therefore,
in the present study, we measured CRP concentration (and leptin concentration as
an index of fat mass) in nine healthy subjects (mean age 53+/-8.1 years; body
mass index 27+/-3.2 kg/m(2); mean arterial blood pressure 101+/-9.0 mmHg)
undergoing measurement of basal endothelial nitric oxide (NO) synthesis using
intra-brachial infusions of N(G)-monomethyl-L-arginine (L-NMMA; a substrate
inhibitor of endothelial NO synthase) and noradrenaline (a non-specific control
vasoconstrictor). In univariate analysis, CRP concentration was correlated with
(i) the percentage decrease in forearm blood flow (FBF) during L-NMMA infusion
(r=0.85, P=0.004); and (ii) the serum leptin concentration (r=0.65, P=0.05). In
multivariate analysis, the relationship between CRP concentration and the FBF
response to L-NMMA remained significant when age and leptin (t=2.65, P=0.045),
age and BMI (t=3.69, P=0.014), or age and low-density-lipoprotein-cholesterol
plus high-density-lipoprotein-cholesterol (t=3.37, P=0.044), were included in
regression models. In contrast, the response of FBF to noradrenaline was not
significantly related to CRP concentration. These data demonstrate for the first
time a relationship between low-grade chronic inflammation and basal endothelial
NO synthesis (measured using an invasive method), and support the notion that
endothelial dysfunction is a critical intermediate phenotype in the relationship
between inflammation and cardiovascular disease.
PMID- 10781384
TI - Resveratrol induces vasorelaxation of mesenteric and uterine arteries from female
guinea-pigs.
AB - Naturally occurring hydroxystilbenes have been shown to induce vasorelaxation.
Here, we studied the mechanism of resveratrol-induced vasorelaxation in different
types of blood vessels, namely mesenteric (resistance) and main uterine
(conductance) arteries, from female guinea-pigs on day 7 and day 15 of the
oestrous cycle. Resveratrol (5-70 micromol/l) induced concentration-dependent
relaxation of both mesenteric and uterine arteries preconstricted with either
noradrenaline (NA; 10 micromol/l) or KCl (125 mmol/l). Resveratrol was 2-fold
more potent in inducing relaxation of mesenteric arteries than of uterine
arteries. Its effects on uterine arteries from both day-7 and day-15 guinea-pigs
were similar, irrespective of the constrictor used, but it was significantly
(P<0.01) more potent in inducing relaxation of mesenteric arteries contracted
with NA compared with those constricted with KCl. In day-7 arteries precontracted
with NA, N(G)-nitro-L-arginine methyl ester (L-NAME; 10 micromol/l) had no
effects on the time course of resveratrol-induced vasorelaxation in either
mesenteric or uterine arteries. However, indomethacin (50 micromol/l)
significantly (P<0.05) potentiated resveratrol's effect on mesenteric, but not
uterine, arteries. Indomethacin had no effect on resveratrol-induced
vasorelaxation of arteries contracted with KCl, whereas L-NAME significantly
(P<0.05) reduced the effects of resveratrol on uterine, but not on mesenteric,
arteries. In day-15 arteries, L-NAME significantly (P<0.01) attenuated the
effects of resveratrol on mesenteric arteries contracted with NA. Indomethacin
had no effect on resveratrol activity. This study indicates that: (a) the effect
of resveratrol on resistance arteries is greater than that on conductance
arteries; (b) the effects of resveratrol are not mediated via prostanoids, but NO
may play a role; and (c) the stage of the oestrous cycle has no influence on
resveratrol-induced vasorelaxation.
PMID- 10781385
TI - Non-invasive measurement of stroke volume during exercise in heart failure
patients.
AB - The objective of the present study was to determine the variability of the
arterio-venous O(2) concentration difference [C(a-v)O(2)] at anaerobic threshold
and at peak oxygen uptake (VO(2)) during a progressively increasing cycle
ergometer exercise test, with the purpose of assessing the possible error in
estimating stroke volume from measurements of VO(2) alone. We sampled mixed
venous and systemic arterial blood every 1 min during a progressively increasing
cycle ergometer exercise test and measured, in each blood sample, haemoglobin
concentration and blood gas data. Ventilation, VO(2) and CO(2) uptake were also
measured continuously. We studied 40 patients with normal haemoglobin
concentrations and with stable heart failure due to ischaemic or idiopathic
cardiomyopathy. Mean values (+/-S.D.) for C(a-v)O(2) were 7.8+/-2.6, 13.0+/-2.4
and 15. 0+/-2.7 ml/100 ml at rest, anaerobic threshold and peak VO(2)
respectively. The patients with heart failure were divided into classes according
to their peak VO(2). Classes A, B and C contained patients with peak VO(2) values
of>20, 15-20 and 10-15 ml.min(-1). kg(-1) respectively. At anaerobic threshold,
C(a-v)O(2) was 12.3+/-1. 3, 13.1+/-2.7 and 13.5+/-2.6 ml/100 ml for classes A, B
and C respectively (class A significantly different from classes B and C;
P<0.05). At peak exercise C(a-v)O(2) was 13.6+/-1.4, 15.6+/-2.5 and 15.4+/-3.2
ml/100 ml for classes A, B and C respectively (class A significantly different
from classes B and C; P<0.05). Stroke volume was estimated for each subject using
the mean values of the measured C(a-v)O(2) in each functional class and
individual values of VO(2) and heart rate using the Fick formulation. The average
difference between the stroke volume estimated from mean C(a-v)O(2) and that
obtained using the patient's actual C(a-v)O(2) value was 9.2+/-9.7, 1.0+/-8.8 and
-0.2+/-6.1 ml at anaerobic threshold, and -1.9+/-11.3, 0.9+/-10.0 and -2.3+/-8.5
ml at peak exercise, in classes A, B and C respectively. Among the various
classes, the most precise estimation of stroke volume was observed for class C
patients. We conclude that stroke volume during exercise can be estimated with
the accuracy needed for most purposes from measurement of VO(2) at the anaerobic
threshold and at peak exercise, and from population-estimated mean values for C(a
v)O(2) in heart failure patients.
PMID- 10781386
TI - Differential timing for programming of glucose homoeostasis, sensitivity to
insulin and blood pressure by in utero exposure to dexamethasone in sheep.
AB - Numerous epidemiological studies have related an increased risk of adult-onset
cardiovascular and metabolic disease to an adverse intra-uterine environment at
critical periods. We have shown that fetal sheep exposed to dexamethasone for
only 2 days at 27 days of gestation (term approximately 150 days) became
hypertensive adults, whereas those exposed at 64 days of gestation remained
normotensive, as did controls. In the same sheep, now nearly 5 years old, we
performed glucose tolerance tests and hyperinsulinaemic euglycaemic clamps to
study the insulin sensitivity of glucose, amino acid and non-esterified fatty
acid metabolism. Glucose tolerance, calculated as the area under the curve, after
intravenous administration of bolus glucose and insulin secretion in response to
a glucose challenge were not altered in any group. There were no significant
differences in the insulin sensitivity of net whole-body glucose or amino acid
uptake. However, suppression of lipolysis by insulin, measured as the
proportional decrease in the circulating concentration of non-esterified fatty
acids during the hyperinsulinaemic clamp, was 69+/-1.2% at steady-state plasma
insulin levels ( approximately 1000 m-units/l) in the group exposed to
dexamethasone at 27 days of gestation, but only 50.8+/-6.5% in the controls
(P<0.05). In the group exposed to dexamethasone at 64 days of gestation, the
decrease was 66.4+/-5.1%, which did not reach significance compared with the
controls (P=0.10). Thus brief dexamethasone exposure during early gestation
programmed hypertension independently of insulin resistance of glucose or amino
acid metabolism; however, it did lead to increased insulin sensitivity of the
inhibition of lipolysis, which may increase susceptibility to the development of
obesity postnatally.
PMID- 10781387
TI - A new treatment for unresectable liver tumours: long-term studies of electrolytic
lesions in the pig liver.
AB - The majority of liver tumours are inoperable and an alternative treatment to
surgical resection is urgently needed. Electrolysis has been investigated in a
rat model and the procedure is safe, with accurate and predictable effects. The
necrosis produced has also been shown to cause destruction of tumour deposits in
the rat liver. A similar evaluation in a large animal model was necessary before
clinical trials could commence. Using platinum electrodes connected to a d.c.
generator, areas of hepatic necrosis were created in the pig liver. Animals were
killed at various time points after treatment to assess the extent of healing.
Treatment was uneventful and all animals made a full recovery. No animal died
from the treatment or had to be killed prematurely. After 2 days of treatment,
healing was minimal but at successive time points there was progressive evidence
of healing, such that after 4 months, the original electrolytic lesion was
greatly reduced in size and the large area of necrosis seen at the early time
points was largely replaced by a fibrous scar with only small islands of necrotic
tissue. In a large animal model, electrolysis is a safe method for creating areas
of hepatic necrosis. The lesions heal with time and are associated with minimal
morbidity. The results support a trial of electrolysis in patients with
unresectable liver tumours.
PMID- 10781388
TI - Comparison of four sequential methods allowing for early stopping of comparative
clinical trials.
AB - Phase III trials aim to assess whether a new treatment has superior efficacy than
a standard treatment. Sequential methods, such as the sequential probability
ratio test (SPRT), the triangular test (TT) and so-called one-parameter
boundaries (OPB), now allow early stopping of such trials, both in the case of
efficacy (alternative hypothesis; H(1)) and in the case of lack of efficacy (null
hypothesis; H(0)). We compared the statistical properties of the SPRT and the TT,
and of OPB with Pocock (OPB(Delta=0.5)) and O'Brien and Fleming (OPB(Delta=0))
type boundaries, in the setting of one-sided comparative trials with normal
response. We studied the type I error (alpha), power (1-beta), average sample
number (ASN) and 90th percentile (P90) of the number of patients required to
reach a conclusion using simulations. The four tests were also compared with the
corresponding single-stage design (SSD). All sequential tests display alpha and 1
beta close to nominal values and, as compared with SSD, allow important decreases
in ASN: for example, -48%, -42%, -40% and -31% under H(0) and H(1) for SPRT, TT,
OPB(Delta=0.5) and OPB(Delta=0) respectively. For situations between H(0) and
H(1), ASNs of all sequential tests were still smaller than the sample size
required by SSD, with the TT displaying the largest decrease (-25%). The P90s of
the TT and OPB(Delta=0) under H(0) and H(1) were smaller than the P90s of the
SPRT and OPB(Delta=0.5), which were similar to the sample size required by SSD.
If all sequential tests display approximately similar features, the TT is the
most appealing regarding decreases in sample size, especially for situations
between H(0) and H(1).
PMID- 10781389
TI - Muscle function during fatigue in myoadenylate deaminase-deficient Dutch
subjects.
AB - Myoadenylate deaminase (MAD) is an enzyme active in skeletal muscle, probably
during exercise of moderate intensity but certainly during vigorous exercise,
when the deamination of AMP leads to increased levels of IMP and ammonia. There
is controversy about the clinical significance of MAD deficiency. The main
objective of the present study was to investigate the extent to which genetically
confirmed MAD deficiency affects muscle function under conditions of maximal
short-term electrically induced activation. The left hand was immobilized and
adductor pollicis muscle function was investigated. To exclude the influence of
central factors, such as the patient's motivation, the ulnar nerve was maximally
electrically activated and force output was measured at the thumb. Sixty rapid
shortening contractions resulted in a decrease of maximal power to 34.2+/-5.4%
and 33.3+/-6.3% (means+/-S.D.) of the values for unfatigued muscle in the control
and MAD-deficient subjects respectively (P>0.05; n=7). Maximal isometric forces
and shortening velocities did not differ between groups in unfatigued, fatigued
or recovered muscle. None of the subjects experienced exercise-related muscle
aches or cramps. In conclusion, MAD deficiency does not appear to affect adductor
pollicis muscle force, shortening velocity and relaxation, either during or after
maximal short-term activation.
PMID- 10781390
TI - Determinants of the acetate recovery factor: implications for estimation of
[13C]substrate oxidation.
AB - When using (13)C or (14)C tracers to study substrate metabolism, an acetate
correction factor should be applied to correct for loss of label in the exchange
pathways of the tricarboxylic acid cycle. We have shown recently that the
[(13)C]acetate recovery factor has a high inter-individual variability and should
therefore be determined in every subject. In the present study we examined the
factors that might explain some of the variability between subjects in acetate
recovery factor. Data were pooled from four different studies with identical
protocols, in which the acetate recovery factor was measured, prior to an
intervention, to correct plasma fatty acid oxidation rates. Acetate recovery was
measured after 2 h of [1, 2-(13)C]acetate infusion at rest followed by 1 h of
cycling exercise at 40-50% of maximal oxygen uptake. Inter-individual variance in
acetate recovery was 12.0% at rest and 16.1% during exercise. Stepwise regression
revealed that, at rest, 37.1% of the acetate recovery could be accounted for by
basal metabolic rate adjusted for fat-free mass, percentage body fat and
respiratory quotient (RQ). During exercise, 69.1% of the variance in acetate
recovery could be accounted for by energy expenditure adjusted for fat-free mass,
% body fat and RQ. In conclusion, we show that the acetate recovery factor has a
high inter-individual variability, both at rest and during exercise, which can
partly be accounted for by metabolic rate, RQ and % body fat. These data indicate
that the acetate recovery factor needs to be determined in every subject, under
similar conditions as used for the tracer-derived determination of substrate
oxidation. Failure to do this might result in large under- or over-estimation of
plasma substrate oxidation, and hence to artificial differences between groups.
PMID- 10781391
TI - Effects of organic and inorganic selenium supplementation on selenoenzyme
activity in blood lymphocytes, granulocytes, platelets and erythrocytes.
AB - The blood selenium (Se) concentration in the U.K. population has declined by
approx. 50% between 1974 and 1991, reflecting a large decrease in dietary Se
supply, with intakes only half the reference nutrient intake of 1 microg/kg body
weight. Tissue levels of Se are readily influenced by dietary intake. Therefore
selenoprotein activity may be sub-optimal due to low Se status, and thus
compromise normal cell function. To examine the effects of changing Se intake on
selenoproteins, we have determined the relative effectiveness of organic
selenomethionine and inorganic sodium selenite (50 microg of Se daily for 28
days) in modulating glutathione peroxidase activities in blood cells from 45
healthy men and women, from a U.K. population. Transient and acute changes in
lymphocyte, granulocyte and platelet phospholipid-hydroperoxide glutathione
peroxidase (GPx4) activity occurred by day 7 or 14 of sodium selenite treatment
and by day 7 in lymphocytes from selenomethionine-treated subjects compared with
controls taking a placebo. In contrast, GPx4 activity in granulocytes and
platelets in the selenomethionine group increased gradually over the 28 days.
Cytosolic glutathione peroxidase (GPx1) activity in these blood cells from both
treatment groups increased gradually over the 28 days. For each cellular
selenoenzyme activity a significant inter-individual difference (P<0.001) in the
extent of the response to Se supplementation was observed, but this was not
related to blood Se concentrations either before or after treatments. Significant
inverse correlations were evident between baseline enzyme activities and
percentage change in activity after 28 days of supplementation [e.g. lymphocyte
GPx4, r=-0.695 (P<0.001)], indicating that pre-treatment activity may be sub
optimal as a result of poor Se status. The different and contrasting effects that
Se supplementation had on blood selenoenzyme activities may be indicative of a
difference in metabolic need for Se regulated at the level of Se-dependent cell
function.
PMID- 10781392
TI - Widespread elevated expression of the human papilloma virus (HPV)-activating
cellular transcription factor Brn-3a in the cervix of women with CIN3 (cervical
intraepithelial neoplasia stage 3).
PMID- 10781393
TI - Prolongation of the QT interval in heart failure occurs at low but not at high
heart rates.
AB - Abnormal left ventricular structure and function as in, for example, left
ventricular hypertrophy or chronic heart failure, is associated with sudden
cardiac death and, when the ejection fraction is depressed, with prolongation of
the QT interval. The dependence on heart rate of QT interval prolongation in
these conditions, and the relationship of any abnormalities either to deranged
autonomic nervous system function or to an adverse prognosis, has not been well
studied. We therefore investigated (1) the dependence on heart rate of the QT
interval, and (2) the relationship between both QT interval and the QT/heart rate
slope and markers of adverse prognosis in these two conditions. The QT interval
was measured at rest and during exercise in 34 subjects with heart failure, 16
subjects with left ventricular hypertrophy and 16 age-matched controls with
normal left ventricular structure and function. QTc (corrected QT) intervals at
rest were significantly longer in heart failure patients (471+/-10 ms) than in
controls (421+/-6 ms) or in subjects with hypertrophy (420+/-6 ms) (P<0.05). At
peak exercise, despite the attainment of similar heart rates, the QT intervals no
longer differed from each other, being 281+/-7 ms for controls, 296+/-11 ms in
hypertrophy and 303+/-10 ms in heart failure (no significant difference). The
QT/heart rate slope was significantly increased in heart failure [2.3+/-0.1
ms.(beats/min)(-1)] compared with controls [1.55+/-0.06 ms.(beats/min)(-1)] and
hypertrophy [1. 66+/-0.1 ms.(beats/min)(-1)] (P<0.001). In left ventricular
hypertrophy, despite animal data suggesting that QT interval prolongation should
occur, no abnormalities were found in QT intervals at rest or during exercise.
The QT/heart rate slope did not relate to any markers for an adverse prognosis,
except that of prolongation of QT interval. Long QT intervals were associated
principally with impairment of left ventricular systolic function. Our data
emphasize the dynamic nature of the QT interval abnormalities found in heart
failure.
PMID- 10781395
TI - Persistent, progressive hypophosphataemia after voluntary hyperventilation.
AB - Hyperventilation (HV) and respiratory alkalosis are associated with
hypophosphataemia, although the extent and duration of HV required to produce
changes in serum phosphate levels are not known. We sought to characterize the
effects of HV, with or without dextrose loading, on serum phosphate levels and
other biochemical parameters. HV was monitored by controlling the end-tidal
partial pressure of carbon dioxide (PETCO(2)). The effect of dextrose was studied
because infusion of a glucose load is known to promote a fall in serum phosphate
via stimulation of glycolysis. Eight healthy volunteers were enrolled in four
study protocols: (1) HV for 20 min to a PETCO(2) of 25-30 mmHg (mild); (2) HV for
20 min to a PETCO(2) of 15-20 mmHg (severe); (3) mild HV with intravenous
dextrose loading, and (4) dextrose loading alone. Periodic measurements of serum
phosphate, venous pH, serum 2,3-diphosphoglycerate (2,3-DPG) and other parameters
were made. Serum phosphate fell during HV and continued to decline after
cessation of HV. Dextrose loading alone caused a fall in serum phosphate that
continued for at least 30 min after cessation of the infusion (P<0.0002). HV
combined with dextrose resulted in a greater decline in serum phosphate than
either variable alone (P=0.003). The maximal decline in serum phosphate occurred
in severe HV, with a mean decrease of 0.38 mmol/l at 20 min after cessation of HV
(P<0.0001). Serum phosphate was still significantly lowered compared with
baseline at 90 min after cessation of HV (P=0.001). Other significant changes
seen with HV included a decrease in serum glucose (P<0.01), a decrease in serum
potassium (P<0.05) and an increase in venous pH (P<0.007). Serum 2, 3-DPG levels
did not change significantly in any study protocol. Thus relatively mild acute HV
produces significant changes in serum phosphate. In both mild and severe HV this
effect is progressive after cessation of HV. This phenomenon has not been shown
before, and may have significant clinical implications.
PMID- 10781394
TI - Haemodynamic and renal evolution of the bile duct-ligated rat.
AB - In the present study we have characterized the evolution of changes in systemic
haemodynamics (thermodilution in conscious animals) and sodium balance (metabolic
cages) in a model of liver cirrhosis induced by chronic bile duct ligation (BDL).
Mean arterial pressure (BDL, 111.5+/-4.7 mmHg; sham-operated, 122.9+/-3.0 mmHg)
and peripheral vascular resistance (BDL, 2.63+/-0.08 units; sham-operated, 2.93+/
0.09 units) were lower in BDL rats from day 12 after surgery and decreased
progressively throughout the following days. Portal hypertension was evident
earlier in BDL rats and was maintained throughout the study period. Cardiac index
(BDL, 58.8+/-3. 9 ml.min(-1).100 g(-1); sham-operated, 43.9+/-1.5 ml.min(-1).100
g(-1)) and stroke volume (BDL, 147.2+/-12.7 ml.beat(-1).100 g(-1); sham-operated,
109.0+/-4.2 ml.beat(-1).100 g(-1)) were significantly elevated in the BDL rats
only from day 18 after surgery. There were no significant differences in sodium
balance between the groups until day 16 after surgery, at which time BDL animals
started to retain significantly more sodium than the controls. Sodium retention
increased progressively, and at day 20 BDL rats had retained 0.7 mmol/100 g more
than the control animals (accumulated retention: BDL, 2.2+/-0.2 mmol/100 g; sham
operated, 1.5+/-0.2 mmol/100 g). Plasma renin activity and aldosterone
concentration were not elevated in the BDL animals at days 12, 16 or 20 after
surgery. These data indicate that the BDL rat model shows early portal
hypertension, peripheral vasodilation and arterial hypotension, several days
before sodium retention is detectable, and in the absence of changes in plasma
levels of renin and aldosterone. Overall, these data suggest that, in the BDL rat
model, sodium retention is secondary to portal hypertension and peripheral
vasodilation.
PMID- 10781396
TI - The increase in sympathetic nerve activity after glucose ingestion is reduced in
type I diabetes.
AB - Food intake is followed by an increase in baroreflex-governed sympathetic outflow
to muscle vessels. It is established that insulin contributes to this
stimulation; however, the increase occurs (to a lesser degree) even in the
absence of enhanced insulin secretion. To further elucidate the role of insulin,
muscle nerve sympathetic activity was recorded by microneurography, and the
increase after an oral 100-g glucose load in eight C-peptide-negative patients
with type I diabetes without any signs of neuropathy was compared with that in 16
healthy control subjects. The level of sympathetic activity at rest was similar
in the two groups (type I diabetes patients, 19.5+/-2.4 bursts/min; controls,
20.4+/-4.8 bursts/min; means+/-S.D.). Following glucose intake there was a
significant increase in activity in both groups, with maximum values at 30 min of
24.3+/-3.7 bursts/min for type I diabetes patients and 34.4+/-9.1 bursts/min for
controls. The summarized response (during 90 min) of the diabetic patients was
less than half that of the control subjects (P=0.0003). It is concluded that the
response of muscle nerve sympathetic activity to glucose ingestion is reduced to
about half of its normal strength in the absence of insulin, and that there is no
difference in sympathetic outflow at rest between healthy subjects and diabetic
patients without polyneuropathy.
PMID- 10781397
TI - Tec family kinases in lymphocyte signaling and function.
AB - The Tec kinases are required for full Ca(2+) mobilization in lymphocytes. Recent
data suggest that this process occurs via a multiprotein complex that includes
LAT and SLP-76 in T cells and BLNK/SLP-65 in B cells. Mutational analyses have
revealed critical roles for Tec kinases in lymphocyte development and function.
PMID- 10781399
TI - Signal transduction by the TCR for antigen.
AB - The past several years have seen the beginning of a shift in the way that TCR
signal transduction is studied. Although many investigators continue to identify
new molecules, particularly adaptor proteins, others have attempted to look at
signaling events in a larger cellular context. Thus the identification of
distinct formations of signaling molecules at junctions between T cells and
antigen-presenting cells, the role of the cytoskeleton and the partitioning of
molecules into specialized lipid subdomains have been the subjects of many
publications. Such concepts are helping to assemble a blueprint of how the myriad
adaptors and kinases fit together to effect T cell activation.
PMID- 10781398
TI - The role of fas ligand in vivo as a cause and regulator of pathogenesis.
AB - Recent studies have significantly advanced our understanding of the physiological
and pathogenic functions of Fas and Fas ligand (FasL) in vivo. In particular,
roles for Fas-FasL interactions both in the induction and regulation of organ
specific autoimmune diseases have been defined and in some cases the specific
targets and effectors of these interactions have been identified. Understanding
the dynamic role of the Fas-FasL pathway in autoimmunity will provide insight
into how best to modulate this interaction to achieve therapeutic benefits.
PMID- 10781400
TI - Inflammation, a prototype for organogenesis of the lymphopoietic/hematopoietic
system.
PMID- 10781401
TI - Membrane rafts and signaling by the multichain immune recognition receptors.
AB - The recent recognition of the presence of rafts in the plasma membrane and of
their involvement in cell signaling has strongly stimulated the search for their
function in receptor-mediated signal transduction in lymphocytes. Recent progress
suggests that a general feature of membrane rafts is to serve as platforms
wherein the signaling cascades triggered through different multichain immune
recognition receptors (e.g. the TCR, BCR and FcepsilonRI) are initiated and
organized.
PMID- 10781402
TI - Regulation of T cell function by NK cell receptors for classical MHC class I
molecules.
AB - Inhibitory receptors for MHC class I molecules were initially characterised on NK
cells. Human and mouse NK cell receptors (NKRs) are also expressed on T cells,
predominantly on a subset of memory-phenotype CD8(+) T cells. This review focuses
on the precise determination of interactions between NKRs and MHC class I, as
well as on the unexpected in vivo function of NKRs on T cells.
PMID- 10781403
TI - Proapoptotic functions of cytotoxic lymphocyte granule constituents in vitro and
in vivo.
AB - Recent advances in our understanding of cytolytic effector mechanisms include the
partial characterization of caspase-independent apoptotic pathways triggered by
granzymes, a realization of the vital importance of perforin and granzymes in the
defence against certain virus infections in vivo and the first description of
hereditary immunodeficiency due to disordered perforin expression in humans.
PMID- 10781404
TI - Adapter proteins in lymphocyte antigen-receptor signaling.
AB - Adapter molecules contain discrete modular domains that direct specific
intermolecular interactions to orchestrate assembly of signaling complexes. A
number of adapter proteins play critical roles in both positive and negative
regulation of antigen-receptor signaling, influencing lymphocyte development and
function.
PMID- 10781405
TI - Transcriptional control of T cell development.
AB - Transcriptional control of T cell development is a complex and rapidly moving
area of investigation. Recent advances reveal critical roles for several
transcription factors in T cell commitment, differentiation and selection. In
particular, new roles for E proteins as well as members of the Notch signaling
pathway have been described. Additionally, a unique function of Ikaros in
chromatin remodeling reveals a novel mechanism by which transcriptional control
may be exerted.
PMID- 10781406
TI - T cell life and death signalling via TNF-receptor family members.
AB - An effective immune response requires the rapid and accurate mobilisation of
millions of effector cells in an antigen driven fashion. These effector cells
must be kept alive long enough to fulfil their function but the majority must
then be eliminated, a process known as activation-induced cell death. Recent
advances in the field of lymphocyte biology have shed light onto how this balance
is maintained and onto the consequences for disease if the homeostatic mechanisms
become disturbed.
PMID- 10781407
TI - Chemokines in tissue-specific and microenvironment-specific lymphocyte homing.
AB - This review describes recent breakthroughs in our understanding of the roles
played by chemokines in lymphocyte trafficking. These include the first
demonstration that chemokines control lymphocyte/vascular recognition by shear
resistant rapid adhesion; the first example of specialized tissue-specific homing
mediated by chemokines; and the implication that chemokines may control
microenvironmental segregation within lymphoid organs.
PMID- 10781408
TI - Functional dissection of BCR signaling pathways.
AB - Signal transduction by the BCR is critical for progression through developmental
checkpoints as well as for immune responses. Recent results obtained in mice
deficient either in an adaptor molecule, BLNK (alternatively named SLP-65 or
BASH), or in phosphatidylinositol 3-kinase have revealed similar - though not
identical - phenotypes to those of Btk(-/-) mice, suggesting a functional link
between BLNK, Btk and phosphatidylinositol 3-kinase.
PMID- 10781409
TI - Regulation of B cell function by linker proteins.
AB - Studies over the past few years have demonstrated the importance of linker or
adaptor proteins in the signaling pathways activated by the B cell antigen
receptor. These proteins direct the appropriate subcellular localization of
enzymatic complexes, amplify signaling pathways and integrate the functions of
distinct signaling complexes. Many of the recently identified linker proteins
function through these distinct mechanisms to upregulate the BCR signaling
pathway. In addition, linker proteins facilitate the influences of co-receptors
that augment or dampen the BCR signaling pathway.
PMID- 10781412
TI - Acute pyelonephritis
PMID- 10781410
TI - Cytoplasmic protein tyrosine phosphatases SHP-1 and SHP-2: regulators of B cell
signal transduction.
AB - One of the areas of greatest recent progress in immunology has been the
elucidation of inhibitory receptors and their mode of signal transduction. A
common feature of members of this growing family is expression of a conserved
cytoplasmic sequence motif, the immunoreceptor tyrosine-based inhibitory motif,
which functions to recruit and activate phosphatases that mediate the receptors'
function. Family members include the protein tyrosine phosphatases SHP-1 (Src
homology-2-domain-containing protein tyrosine phosphatase 1) and SHP-2, which
function to dephosphorylate key intermediaries in antigen receptor signaling
pathways. Surprisingly, whereas most data to date support a role for SHP-1 in
inhibitory signaling, SHP-2 exhibits distinct functions that appear to positively
regulate receptor function.
PMID- 10781411
TI - Ras regulation and function in lymphocytes.
AB - The GTPase, Ras, is rapidly activated in antigen receptor stimulated T. cells, B
cells and mast cells. Ras can bind to diverse effector molecules when activated
and thereby switch on multiple downstream effector pathways. In lymphocytes Ras
plays an important role in the signalling pathways that activate transcription
factors involved in cytokine gene induction. Ras is also a key component of the
complex regulatory networks that control T and B cell development.
PMID- 10781413
TI - Continuing medical education exercise, february 2000
PMID- 10781414
TI - Type I membranoproliferative glomerulonephritis in a renal allograft: A
recurrence induced by a cytomegalovirus infection?
AB - A 40-year-old white woman with end-stage renal disease from idiopathic type I
membranoproliferative glomerulonephritis (MPGN) developed proteinuria and renal
dysfunction 7 weeks after cadaveric donor renal transplantation. At the same
time, a primary cytomegalovirus (CMV) infection was diagnosed. Complement levels
were low. A renal biopsy disclosed an acute exudative proliferative
glomerulonephritis with influx of polymorphonuclear granulocytes (PMNs), with
granular deposits of C3, C1q, IgG, and IgM. The immunofluorescence (IF) and
electron microscopy (EM) findings were compatible with an early stage of a type I
MPGN. CMV could not be detected in the glomeruli nor elsewhere in the kidney by
IF or EM. The patient was treated with ganciclovir. In a renal biopsy 3 weeks
later, the exudative lesions had disappeared, and some glomeruli now showed the
characteristic lesions of a type I MPGN with an increase of mesangial cells and
matrix, and reduplication of the glomerular basement membrane. Over the following
period, repeated biopsies were performed. The activity of the glomerular
inflammation and immune complex deposits paralleled the waxing and waning of the
CMV viral load. After 10.5 months, the graft was removed because of a life
threatening systemic fungal infection. At that time, the CMV infection had
cleared, and in the transplantectomy material, the membranoproliferative pattern
of injury had disappeared, and in the glomeruli hardly any deposits were found.
These data strongly suggest that a primary CMV virus infection can induce an
apparent recurrence of type I MPGN.
PMID- 10781415
TI - Publishing in the journals of the APS: why are authors charged fees?
PMID- 10781416
TI - Aquaporin water channels and lung physiology.
AB - Fluid transport across epithelial and endothelial barriers occurs in the neonatal
and adult lungs. Biophysical measurements in the intact lung and cell isolates
have indicated that osmotic water permeability is exceptionally high across
alveolar epithelia and endothelia and moderately high across airway epithelia.
This review is focused on the role of membrane water-transporting proteins, the
aquaporins (AQPs), in high lung water permeability and lung physiology. The lung
expresses several AQPs: AQP1 in microvascular endothelia, AQP3 in large airways,
AQP4 in large- and small-airway epithelia, and AQP5 in type I alveolar epithelial
cells. Lung phenotype analysis of transgenic mice lacking each of these AQPs has
been informative. Osmotically driven water permeability between the air space and
capillary compartments is reduced approximately 10-fold by deletion of AQP1 or
AQP5 and reduced even more by deletion of AQP1 and AQP4 or AQP1 and AQP5
together. AQP1 deletion greatly reduces osmotically driven water transport across
alveolar capillaries but has only a minor effect on hydrostatic lung filtration,
which primarily involves paracellular water movement. However, despite the major
role of AQPs in lung osmotic water permeabilities, AQP deletion has little or no
effect on physiologically important lung functions, such as alveolar fluid
clearance in adult and neonatal lung, and edema accumulation after lung injury.
Although AQPs play a major role in renal and central nervous system physiology,
the data to date on AQP knockout mice do not support an important role of high
lung water permeabilities or AQPs in lung physiology. However, there remain
unresolved questions about possible non-water-transporting roles of AQPs and
about the role of AQPs in airway physiology, pleural fluid dynamics, and edema
after lung infection.
PMID- 10781417
TI - Lipopolysaccharide induces relaxation in lung pericytes by an iNOS-independent
mechanism.
AB - Lipopolysaccharide (LPS)-regulated contractility in pericytes may play an
important role in mediating pulmonary microvascular fluid hemodynamics during
inflammation and sepsis. LPS has been shown to regulate inducible nitric oxide
(NO) synthase (iNOS) in various cell types, leading to NO generation, which is
associated with vasodilatation. The purpose of this study was to test the
hypothesis that LPS can regulate relaxation in lung pericytes and to determine
whether this relaxation is mediated through the iNOS pathway. As predicted, LPS
stimulated NO synthesis and reduced basal tension by 49% (P < 0.001). However,
the NO synthase inhibitors N (omega)-nitro-L-arginine methyl ester,
aminoguanidine, and N (omega)-monomethyl-L-arginine did not block the relaxation
produced by LPS. In fact, aminoguanidine and N (omega)-monomethyl-L-arginine
potentiated the LPS response. The possibility that NO might mediate either
contraction or relaxation of the pericyte was further investigated through the
use of NO donor compounds; however, neither sodium nitroprusside nor S-nitroso-N
acetylpenicillamine had any significant effect on pericyte contraction. The
inhibitory effect of aminoguanidine on LPS-stimulated NO production was
confirmed. This ability of LPS to inhibit contractility independent of iNOS was
also demonstrated in lung pericytes derived from iNOS-deficient mice. This
suggests the presence of an iNOS-independent but as yet undetermined pathway by
which lung pericyte contractility is regulated.
PMID- 10781418
TI - Histamine alters endothelial barrier function at cell-cell and cell-matrix sites.
AB - To determine how histamine regulates endothelial barrier function through an
integrative cytoskeletal network, we mathematically modeled the resistance across
an endothelial cell-covered electrode as a function of cell-cell, cell-matrix,
and transcellular resistances. Based on this approach, histamine initiated a
rapid decrease in transendothelial resistance predominantly through decreases in
cell-cell resistance in confluent cultured human umbilical vein endothelial cells
(HUVECs). Restoration of resistance was characterized by initially increasing
cell-matrix resistance, with later increases in cell-cell resistance. Thus
histamine disrupts barrier function by specifically disrupting cell-cell adhesion
and restores barrier function in part through direct effects on cell-matrix
adhesion. To validate the precision of our technique, histamine increased the
resistance in subconfluent HUVECs in which there was no cell-cell contact.
Exposure of confluent monolayers to an antibody against cadherin-5 caused a
predominant decrease in cell-cell resistance, whereas the resistance was
unaffected by the antibody to cadherin-5 in subconfluent cells. Furthermore, we
observed an increase predominantly in cell-cell resistance in ECV304 cells that
were transfected with a plasmid containing a glucocorticoid-inducible promoter
controlling expression of E-cadherin. Transmission electron microscopy confirmed
tens of nanometer displacements between adjacent cells at a time point in which
histamine maximally decreased cell-cell resistance.
PMID- 10781419
TI - NO(+) but not NO radical relaxes airway smooth muscle via cGMP-independent
release of internal Ca(2+).
AB - We compared the effects of two redox forms of nitric oxide, NO(+) [liberated by S
nitroso-N-acetyl-penicillamine (SNAP)] and NO. [liberated by 3
morpholinosydnonimine (SIN-1) in the presence of superoxide dismutase], on
cytosolic concentration of Ca(2+) ([Ca(2+)](i); single cells) and tone (intact
strips) obtained from human main stem bronchi and canine trachealis. SNAP evoked
a rise in [Ca(2+)](i) that was unaffected by removing external Ca(2+) but was
markedly reduced by depleting the internal Ca(2+) pool using cyclopiazonic acid
(10(-5) M). Dithiothreitol (1 mM) also antagonized the Ca(2+) transient as well
as the accompanying relaxation. SNAP attenuated responses to 15 and 30 mM KCl but
not those to 60 mM KCl, suggesting the involvement of an electromechanical
coupling mechanism rather than a direct effect on the contractile apparatus or on
Ca(2+) channels. SNAP relaxations were sensitive to charybdotoxin (10(-7) M) or
tetraethylammonium (30 mM) but not to 4-aminopyridine (1 mM). Neither SIN-1 nor 8
bromoguanosine 3',5'-cyclic monophosphate had any significant effect on resting
[Ca(2+)](i), although both of these agents were able to completely reverse tone
evoked by carbachol (10(-7) M). We conclude that NO(+) causes release of internal
Ca(2+) in a cGMP-independent fashion, leading to activation of Ca(2+)-dependent
K(+) channels and relaxation, whereas NO. relaxes the airways through a cGMP
dependent, Ca(2+)-independent pathway.
PMID- 10781420
TI - Increased expression of inflammatory mediators in small-airway epithelium from
tobacco smokers.
AB - To study the inflammatory responses of small-airway epithelium in smokers, we
harvested enough living epithelial cells (1.97 x 10(6) +/- 0.74 x 10(6)) with a
new ultrathin fiberscope from the very peripheral airways of 22 current smokers
and 17 subjects who never smoked after informed consent was obtained. The cells
were keratin positive and composed mainly of nonciliated cells. The expression
levels of inflammatory markers [interleukin (IL)-8 and intercellular adhesion
molecule (ICAM)-1] were evaluated with RT-PCR. The magnitude of the mRNA levels
corrected by beta-actin transcripts of IL-8 and ICAM-1 was significantly higher
in the smokers than in the nonsmokers (P < 0.001). Furthermore, among current
smokers, IL-8 mRNA levels correlated positively with the extent of smoking
history [in pack. years (packs/day x no. of years of smoking); r = 0.754, P <
0.001]. Spontaneously released IL-8 and soluble ICAM-1 levels (n = 12) from
cultured epithelial cells were elevated in subjects with a smoking history than
in those without it (IL-8, 1,580 +/- 29.6 vs. 354 +/- 39.4 pg. 10(6) cells(-1).
24 h(-1); P < 0.001; soluble ICAM-1, 356.0 +/- 45.9 vs. 112.9 +/- 12.9 pg. 10(6)
cells(-1). 24 h(-1); P < 0.01 by Student's t-test ). In contrast, the epithelial
cells from the main bronchi did not show such differences between smokers and
nonsmokers. Our study highlighted a close link between smoking and the expression
of inflammatory mediators such as IL-8 and ICAM-1 in small airways. Our results
also suggested that this new ultrathin bronchofiberscope promised a good approach
for the evaluation of cellular changes in the small airways.
PMID- 10781421
TI - Introduction of the interleukin-10 gene into mice inhibited bleomycin-induced
lung injury in vivo.
AB - Interleukin (IL)-10 has been shown to reduce many inflammatory reactions. We
investigated the in vivo effects of IL-10 on a bleomycin-induced lung injury
model. Hemagglutinating virus of Japan (HVJ)-liposomes containing a human IL-10
expression vector (hIL10-HVJ) or a balanced salt solution as a control (Cont-HVJ)
was intraperitoneally injected into mice on day -3. This was followed by
intratracheal instillation of bleomycin (0.8 mg/kg) on day 0. Myeloperoxidase
activity of bronchoalveolar lavage fluid and tumor necrosis factor-alpha mRNA
expression in bronchoalveolar lavage fluid cells on day 7 and hydroxyproline
content of the whole lung on day 21 were inhibited significantly by hIL10-HVJ
treatment. However, Cont-HVJ treatment could not suppress any of these
parameters. We also examined the in vitro effects of IL-10 on the human lung
fibroblast cell line WI-38. IL-10 significantly reduced constitutive and
transforming growth factor-beta-stimulated type I collagen mRNA expression.
However, IL-10 did not affect the proliferation of WI-38 cells induced by
platelet-derived growth factor. These data suggested that exogenous IL-10 may be
useful in the treatment of pulmonary fibrosis.
PMID- 10781422
TI - ET(A)-receptor blockade and ET(B)-receptor stimulation in experimental congenital
diaphragmatic hernia.
AB - The aim of this study was to assess the role of nitric oxide (NO) and endothelin
(ET)-1 in the pathophysiology of persistent pulmonary hypertension of the newborn
in fetal lambs with a surgically created congenital diaphragmatic hernia (CDH).
The pulmonary vascular response to various agonists and antagonists was assessed
in vivo between 128 and 132 days gestation. Age-matched fetal lambs served as
control animals. Control and CDH lambs had similar pulmonary vasodilator
responses to acetylcholine, sodium nitroprusside, zaprinast, and dipyridamole.
The ET(A)-receptor antagonist BQ-123 caused a significantly greater pulmonary
vasodilatation in CDH than in control animals. The ET(B)-receptor agonist
sarafotoxin 6c induced a biphasic response, with a sustained pulmonary
vasoconstriction after a transient pulmonary vasodilatation that was not seen in
CDH animals. We conclude that the NO signaling pathway in vivo is intact in
experimental CDH. In contrast, ET(A)-receptor blockade and ET(B)-receptor
stimulation significantly differed in CDH animals compared with control animals.
Imbalance of ET-1-receptor activation favoring pulmonary vasoconstriction rather
than altered NO-mediated pulmonary vasodilatation is likely to account for
persistent pulmonary hypertension of the newborn in fetal lambs with a surgically
created CDH.
PMID- 10781423
TI - Human SP-C gene sequences that confer lung epithelium-specific expression in
transgenic mice.
AB - We used transgenic mice to identify cis-active regions of the human pulmonary
surfactant protein C (SP-C) gene that impart tissue- and cell-specific expression
in vivo in the lung. Approximately 3.7 kb of genomic SP-C DNA upstream of the
transcription start site was sufficient to direct chloramphenicol
acetyltransferase (CAT) reporter gene expression specifically in bronchiolar and
alveolar epithelial cells of the lung. To further define cis-active regulatory
elements that mediate cell-specific expression, we tested deletions of the
parental 3.7-kb human SP-C sequence in transgenic mice. Tissue CAT assays of mice
generated with truncations or overlapping internal deletions of the 3.7-kb
construct functionally map alveolar cell-specific regulatory elements to within
215 bp of the SP-C promoter. Analysis of SP-C promoter deletions demonstrate that
sequences between -3.7 kb and -1.9 kb contain enhancer sequences that stimulate
SP-C transgene expression. In situ hybridization studies demonstrate that
deletion of the -1,910- to -215-bp region abolishes the ectopic bronchiolar
expression seen with the original 3.7-kb SP-C promoter construct. Comparison of
sequences from -215 to +1 bp identified consensus binding sites for the
homeodomain transcription factor thyroid transcription factor-1 (TTF-1).
Cotransfection assays of the human 3.7-kb SP-C or -1,910- to -215-bp SP-C
deletion construct with a TTF-1 expression plasmid demonstrates that TTF-1
transactivates the human SP-C gene. These results suggest that the TTF-1 cis
active sites are important in directing cell-specific expression of the SP-C gene
in vivo.
PMID- 10781425
TI - Retinoic acid treatment partially rescues failed septation in rats and in mice.
AB - Pulmonary alveoli are formed in part by subdivision (septation) of the gas
exchange saccules of the immature lung. Septation results in smaller, more
numerous structures (alveoli) and is developmentally regulated in mammals
including humans, rats, and mice; if it fails to occur at the appropriate time,
there is no spontaneous post hoc septation nor has there been a means of inducing
septation after it has failed to occur. We measured lung volume, the volume of
individual alveoli, and alveolar surface area and calculated alveolar number in
neonatal rats in which septation had been blocked by treatment with a
glucocorticosteroid hormone and in adult tight-skin mice that have a genetic
failure of septation. We tested the hypothesis that treatment with all-trans
retinoic acid induces post hoc septation. In both models of failed septation,
hence in two species, and in immature and adult animals, treatment with all-trans
retinoic acid induced post hoc septation, offering the possibility of a similar
effect in premature infants.
PMID- 10781424
TI - Human SP-A protein variants derived from one or both genes stimulate TNF-alpha
production in the THP-1 cell line.
AB - In humans, two functional genes of surfactant protein (SP) A, SP-A1 and SP-A2,
and several alleles of each functional gene have been characterized. SP-A is a
multimeric molecule consisting of six trimers. Each trimer contains two SP-A1
molecules and one SP-A2 molecule. Until now, it has been unclear whether a single
SP-A gene product is functional or whether there are functional differences
either among alleles or between single-gene SP-A products and SP-A products
derived from both genes. We tested the ability of in vitro expressed SP-A
variants to stimulate tumor necrosis factor (TNF)-alpha production by THP-1
cells. We observed that 1) single-gene products and products derived from both
genes stimulate TNF-alpha production, 2) there are differences among SP-A1 and SP
A2 alleles in their ability to stimulate TNF-alpha production, and 3) the
increases in TNF-alpha production are lower after treatment with the SP-A1
alleles than after treatment with the SP-A2 alleles. Furthermore, coexpressed SP
As from SP-A1 and SP-A2 genes have a higher activity compared with SP-As from
individual alleles or mixed SP-As from SP-A1 and SP-A2 genes. These data suggest
that the SP-A-induced increases in TNF-alpha levels differ among SP-A variants
and appear to be affected by SP-A genotype and whether SP-A is derived from one
or both genes.
PMID- 10781427
TI - Mediators of alkalosis-induced relaxation of piglet pulmonary veins.
AB - Pulmonary venous constriction leads to significant pulmonary hypertension and
increased edema formation in several models using newborns. Although alkalosis is
widely used in treating neonatal and pediatric pulmonary hypertension, its
effects on pulmonary venous tone have not previously been directly measured. This
study sought to determine whether alkalosis caused pulmonary venous relaxation
and, if so, to identify the mediator(s) involved. Pulmonary venous rings (500
microm external diameter) were isolated from 1-wk-old piglets and precontracted
with the thromboxane mimetic U-46619. Responses to hypocapnic alkalosis were then
measured under control conditions after inhibition of endothelium-derived
modulator activity or K(+) channels. In control rings, alkalosis caused a 34.4 +/
4.8% decrease in the U-46619-induced contraction. This relaxation was
significantly blunted in rings without functional endothelium and in rings
treated with nitric oxide synthase or guanylate cyclase inhibitors. However,
neither cyclooxygenase inhibition nor voltage-dependent, calcium-dependent, or
ATP-dependent K(+)-channel inhibitors altered alkalosis-induced relaxation. These
data suggest that alkalosis caused significant dilation of piglet pulmonary veins
that was mediated by the nitric oxide-cGMP pathway.
PMID- 10781426
TI - Plasma proteins modified by tyrosine nitration in acute respiratory distress
syndrome.
AB - The present study identifies proteins modified by nitration in the plasma of
patients with ongoing acute respiratory distress syndrome (ARDS). The proteins
modified by nitration in ARDS were revealed by microsequencing and specific
antibody detection to be ceruloplasmin, transferrin, alpha(1)-protease inhibitor,
alpha(1)-antichymotrypsin, and beta-chain fibrinogen. Exposure to nitrating
agents did not deter the chymotrypsin-inhibiting activity of alpha(1)
antichymotrypsin. However, the ferroxidase activity of ceruloplasmin and the
elastase-inhibiting activity of alpha(1)-protease inhibitor were reduced to 50.3
+/- 1.6 and 60.3 +/- 5.3% of control after exposure to the nitrating agent. In
contrast, the rate of interaction of fibrinogen with thrombin was increased to
193.4 +/- 8.5% of the control value after exposure of fibrinogen to nitration.
Ferroxidase activity of ceruloplasmin and elastase-inhibiting activity of the
alpha(1)-protease inhibitor in the ARDS patients were significantly reduced (by
81 and 44%, respectively), whereas alpha(1)-antichymotrypsin activity was not
significantly altered. Posttranslational modifications of plasma proteins
mediated by nitrating agents may offer a biochemical explanation for the reported
diminished ferroxidase activity, elevated levels of elastase, and fibrin deposits
detected in patients with ongoing ARDS.
PMID- 10781428
TI - Mechanical strain and dexamethasone selectively increase surfactant protein C and
tropoelastin gene expression.
AB - Physical forces derived from fetal breathing movements and hormones such as
glucocorticoids are implicated in regulating fetal lung development. To elucidate
whether the different signaling pathways activated by physical and hormonal
factors are integrated and coordinated at the cellular and transcriptional
levels, organotypic cultures of mixed fetal rat lung cells were subjected to
static culture or mechanical strain in the presence and absence of dexamethasone.
Tropoelastin and collagen type I were used as marker genes for fibroblasts,
whereas surfactant protein (SP) A and SP-C were used as marker genes for distal
epithelial cells. Mechanical strain, but not dexamethasone, significantly
increased SP-C mRNA expression. Tropoelastin mRNA expression was upregulated by
both mechanical strain and dexamethasone. No additive or synergistic effect was
observed when cells were subjected to mechanical stretch in the presence of
dexamethasone. Neither mechanical strain nor dexamethasone alone or in
combination had any significant effect on the expression of SP-A mRNA.
Dexamethasone decreased collagen type I mRNA expression, whereas mechanical
strain had no effect. The increases in tropoelastin and SP-C mRNA levels induced
by mechanical strain and/or dexamethasone were accompanied by increases in their
heterogeneous nuclear RNA. In addition, the stretch- and glucocorticoid-induced
alterations in tropoelastin and SP-C mRNA expression were abrogated with 10
microg/ml actinomycin D. These findings suggest that tropoelastin and SP-C genes
are selectively stimulated by physical and/or hormonal factors at the
transcriptional level in fetal lung fibroblasts and distal epithelial cells,
respectively.
PMID- 10781429
TI - Vascular remodeling and ET-1 expression in rat strains with different responses
to chronic hypoxia.
AB - Chronic hypoxia leads to a greater degree of pulmonary hypertension in the Wistar
Kyoto (WKY) rat than in the Fischer 344 (F-344) rat. We questioned whether this
difference is associated with baseline differences in pulmonary artery anatomy, a
greater degree of hypoxia-induced pulmonary vascular remodeling in the WKY rat,
and/or differences in expression of endothelin (ET)-1. Male F-344 and WKY rats
were maintained in normoxia or normobaric hypoxia for 21 days. Morphometry
revealed that baseline pulmonary artery anatomy was similar in the two strains.
However, during chronic hypoxia, the WKY rats developed a greater degree of
muscularization of small pulmonary arteries. Baseline plasma and lung
immunoreactive ET-1 levels were similar in the WKY and F-344 rats and increased
significantly during hypoxia in the WKY rats. Northern analysis demonstrated
increased lung preproET-1 mRNA during hypoxia in both strains, with a greater
increase in WKY rats. Immunostaining demonstrated increased ET-1 in bronchial
epithelium and peripheral pulmonary arteries during hypoxia, although to a
greater degree in the WKY rats. We conclude that the WKY strain demonstrates
increased susceptibility to hypoxia-induced pulmonary vascular remodeling
compared with the F-344 strain and that increased lung and circulating ET-1
levels during hypoxia may partly explain this difference.
PMID- 10781430
TI - KGF pretreatment decreases B7 and granzyme B expression and hastens repair in
lungs of mice after allogeneic BMT.
AB - We investigated keratinocyte growth factor (KGF) as a pretreatment therapy for
idiopathic pneumonia syndrome (IPS) generated as a result of lung damage and
allogeneic T cell-dependent inflammatory events occurring in the early peri-bone
marrow (BM) transplant (BMT) period. B10.BR (H2(k)) recipient mice were
transplanted with C57BL/6 (H2(b)) BM with spleen cells after lethal irradiation
with and without cyclophosphamide conditioning with and without subcutaneous KGF
pretreatment. KGF-pretreated mice had fewer injured alveolar type II (ATII) cells
at the time of BMT and exhibited ATII cell hyperplasia at day 3 post-BMT. The
composition of infiltrating cells on day 7 post-BMT was not altered by KGF
pretreatment, but the frequencies of cells expressing the T-cell costimulatory
molecules B7.1 and B7.2 and mRNA for the cytolysin granzyme B (usually increased
in IPS) were decreased by KGF. Sera from KGF-treated mice had increases in the
Th2 cytokines interleukin (IL)-4, IL-6, and IL-13 4 days after cessation of KGF
administration (i.e., at the time of BMT). These data suggest that KGF hinders
IPS by two modes: 1) stimulation of alveolar epithelialization and 2) attenuation
of immune-mediated injury as a consequence of failure to upregulate cytolytic
molecules and B7 ligand expression and the induction of anti-inflammatory Th2
cytokines in situ.
PMID- 10781432
TI - Perflubron attenuates neutrophil adhesion to activated endothelial cells in
vitro.
AB - Infiltration of activated neutrophils into the lung appears to be a key element
in the severe lung injury that develops in animal models of acute lung injury.
Partial liquid ventilation with perflubron has been shown to ameliorate tissue
damage compared with conventional mechanical ventilation in acute lung injury
models. Pilot experiments indicated that indirect exposure to perflubron could
modulate the degree to which subsequent neutrophil binding to endothelial cell
monolayers was upregulated after lipopolysaccharide activation. Endothelial cell
monolayers preexposed to perflubron showed >40% reductions in the surface steady
state levels of E-selectin and intercellular adhesion molecule-1 achieved after
proinflammatory activation (P < 0.05), which correlated with a reduction in the
real-time association constants measured by biosensor techniques. These results
indicate that direct contact with the perflubron liquid phase is not necessary to
attenuate inflammatory responses. Rather, diffusion of perflubron from the
alveolar space into the adjacent pulmonary vascular endothelial layer may
modulate neutrophil adhesion and thereby reduce the rate of infiltration of
activated neutrophils into the injured lung.
PMID- 10781431
TI - Angiogenesis and morphogenesis of murine fetal distal lung in an allograft model.
AB - Neovascularization is crucial to lung morphogenesis; however, factors determining
vessel growth and formation are poorly understood. The goal of our study was to
develop an allograft model that would include maturation of the distal lung,
thereby ultimately allowing us to study alveolar development, including
microvascular formation. We transplanted 14-day gestational age embryonic mouse
lung primordia subcutaneously into the back of nude mice for 3.5-14 days. Lung
morphogenesis and neovascularization were evaluated by light microscopy, in situ
hybridization, and immunohistochemical techniques. Embryonic 14-day gestational
age control lungs had immature structural features consistent with
pseudoglandular stage of lung development. In contrast, 14 days after
subcutaneous transplantation of a 14-day gestational age lung, the allograft
underwent significant structural morphogenesis and neovascularization. This was
demonstrated by continued neovascularization and cellular differentiation,
resulting in mature alveoli similar to those noted in the 2-day postnatal
neonatal lung. Confirmation of maturation of the allograft was provided by
progressive type II epithelial cell differentiation as evidenced by enhanced
local expression of mRNA for surfactant protein C and a threefold (P < 0.008)
increase in vessel formation as determined by immunocytochemical detection of
platelet endothelial cell adhesion molecule-1 expression. Using the tyrosine
kinase Flk-1 receptor (flk-1) LacZ transgene embryos, we determined that the
neovascularization within the allograft was from the committed embryonic lung
endothelium. Therefore, we have developed a defined murine allograft model that
can be used to study distal lung development, including neovascularization. The
model may be useful when used in conjunction with an altered genetic background
(knockout or knock in) of the allograft and has the further decided advantage of
bypassing placental barriers for introduction of pharmacological agents or DNA
directly into the lung itself.
PMID- 10781433
TI - In vitro cellular effects of perfluorochemicals correlate with their lipid
solubility.
AB - Preclinical studies comparing perflubron partial liquid ventilation with
conventional mechanical ventilation have indicated that perflubron partial liquid
ventilation may exert some anti-inflammatory effects. To assess whether these
effects were related to the lipid solubility properties of perflubron rather than
to nonspecific biophysical properties of the perfluorocarbon (PFC) liquid phase,
we studied the effects of PFCs with varying lipid solubilities on the platelet
aggregation response to various procoagulants and the erythrocyte hemolytic
response to osmotic stress. In both cases, the degree of the response was
directly related to the lipid solubility of the PFC. All the perflubron content
of erythrocytes was found to be associated with the membrane compartment. The
time to reach a maximum effect on hemolysis with perflubron was relatively slow
(2-4 h), which paralleled the time for perflubron to accumulate in erythrocyte
membranes. The rate and extent of perflubron partitioning into lecithin liposomes
were similar to those of erythrocyte membranes, supporting the hypothesis that
perflubron was partitioning into the lipid component of the membranes. Thus some
of the potential modulatory effects of perflubron on excessive inflammatory
responses that occur during acute lung injury and acute respiratory distress
syndrome may be influenced in part by the extent of PFC partitioning into the
lipid bilayers of cellular membranes.
PMID- 10781435
TI - Sodium nitroprusside augments human lung fibroblast collagen gel contraction
independently of NO-cGMP pathway.
AB - Nitric oxide (NO) relaxes vascular smooth muscle in part through an accumulation
of cGMP in the target cells. We hypothesized that a similar effect may also exist
on collagen gel contraction mediated by human fetal lung (HFL1) fibroblasts, a
model of wound contraction. To evaluate this, HFL1 cells were cultured in three
dimensional type I collagen gels and floated in serum-free DMEM with and without
various NO donors. Gel size was measured with an image analyzer. Sodium
nitroprusside (SNP, 100 microM) significantly augmented collagen gel contraction
by HFL1 cells (78.5 +/- 0.8 vs. 58.3 +/- 2. 1, P < 0.01), whereas S-nitroso-N
acetylpenicillamine, 5-amino-3-(4-morpholinyl)-1,2,3-oxadiazolium chloride,
NONOate, and N(G)-monomethyl-L-arginine did not affect the contraction. Sodium
ferricyanide, sodium nitrate, or sodium nitrite was not active. The augmentory
effect of SNP could not be blocked by 1H-[1,2, 4]-oxadiazolo-[4,3-a]-quinoxalin-1
one, whereas it was partially reversed by 8-(4-chlorophenylthio) (CPT)-cGMP. To
further explore the mechanisms by which SNP acted, fibronectin and PGE(2)
production were measured by immunoassay after 2 days of gel contraction. SNP
inhibited PGE(2) production and increased fibronectin production by HFL1 cells in
a concentration-dependent manner. CPT-cGMP had opposite effects on fibronectin
and PGE(2) production. Addition of exogenous PGE(2) blocked SNP-augmented
contraction and fibronectin production by HFL1 cells. Therefore, SNP was able to
augment human lung fibroblast-mediated collagen gel contraction, an effect that
appears to be independent of NO production and not mediated through cGMP.
Decreased PGE(2) production and augmented fibronectin production may have a role
in this effect. These data suggest that human lung fibroblasts in three
dimensional type I collagen gels respond distinctly to SNP by mechanisms
unrelated to the NO-cGMP pathway.
PMID- 10781434
TI - Carbon dioxide enhances nitration of surfactant protein A by activated alveolar
macrophages.
AB - We assessed whether reactive oxygen-nitrogen intermediates generated by alveolar
macrophages (AMs) oxidized and nitrated human surfactant protein (SP) A. SP-A was
exposed to lipopolysaccharide (100 ng/ml)-activated AMs in 15 mM HEPES (pH 7.4)
for 30 min in the presence and absence of 1.2 mM CO(2). In the presence of CO(2),
lipopolysaccharide-stimulated AMs had significantly higher nitric oxide synthase
(NOS) activity (as quantified by the conversion of L-[U-(14)C]arginine to L-[U
(14)C]citrulline) and secreted threefold higher levels of nitrate plus nitrite in
the medium [28 +/- 3 vs. 6 +/- 1 (SE) nmol. 6.5 h(-1). 10(6) AMs(-1)]. Western
blotting studies of immunoprecipitated SP-A indicated that CO(2) enhanced SP-A
nitration by AMs and decreased carbonyl formation. CO(2) (0-1.2 mM) also
augmented peroxynitrite (0.5 mM)-induced SP-A nitration in a dose-dependent
fashion. Peroxynitrite decreased the ability of SP-A to aggregate lipids, and
this inhibition was augmented by 1.2 mM CO(2). Mass spectrometry analysis of
chymotryptic fragments of peroxynitrite-exposed SP-A showed nitration of two
tyrosines (Tyr(164) and Tyr(166)) in the absence of CO(2) and three tyrosines
(Tyr(164), Tyr(166), and Tyr(161)) in the presence of 1.2 mM CO(2). These
findings indicate that physiological levels of peroxynitrite, produced by
activated AMs, nitrate SP-A and that CO(2) increased nitration, at least
partially, by enhancing enzymatic nitric oxide production.
PMID- 10781436
TI - Amiodarone induces apoptosis of human and rat alveolar epithelial cells in vitro.
AB - The antiarrhythmic amiodarone (AM) and its metabolite desethylamiodarone (Des)
are known to cause AM-induced pulmonary toxicity, but the mechanisms underlying
this disorder remain unclear. We hypothesized that AM might cause AM-induced
pulmonary toxicity in part through the induction of apoptosis or necrosis in
alveolar epithelial cells (AECs). Two models of type II pneumocytes, the human
AEC-derived A549 cell line and primary AECs isolated from adult Wistar rats, were
incubated with AM or Des for 20 h. Apoptotic cells were determined by
morphological assessment of nuclear fragmentation with propidium iodide on
ethanol-fixed cells. Necrotic cells were quantitated by loss of dye exclusion.
Both AM and Des caused dose-dependent necrosis starting at 2.5 and 0.1 microg/ml,
respectively, in primary rat AECs and at 10 and 5 microg/ml in subconfluent A549
cells (P < 0.05 and P < 0.01, respectively). AM and Des also induced dose
dependent apoptosis beginning at 2.5 microg/ml in the primary AECs (P < 0.05 for
both compounds) and at 10 and 5 microg/ml, respectively, in the A549 cell line (P
< 0.01). The two compounds also caused significant net cell loss (up to 80% over
20 h of incubation) by either cell type at drug concentrations near or below the
therapeutic serum concentration for AM. The cell loss was not due to detachment
but was blocked by the broad-spectrum caspase inhibitor Z-Val-Ala-Asp
fluoromethylketone. Furthermore, the angiotensin-converting enzyme inhibitor
captopril (500 ng/ml) and the angiotensin-receptor antagonist saralasin (50
microg/ml) significantly inhibited both the induction of apoptosis and net cell
loss in response to AM. These results are consistent with recent work from this
laboratory demonstrating potent inhibition of apoptosis in human AECs by
captopril (Uhal BD, Gidea C, Bargout R, Bifero A, Ibarra-Sunga O, Papp M, Flynn
K, and Filippatos G. Am J Physiol Lung Cell Mol Physiol 275: L1013-L1017, 1998).
They also suggested that the accumulation of AM and/or its primary metabolite Des
in lung tissue may induce cytotoxicity of AECs that might be inhibitable by
angiotensin-converting enzyme inhibitors or other antagonists of the renin
angiotensin system.
PMID- 10781437
TI - TRAIL expression in vascular smooth muscle.
AB - TRAIL is a cell-associated tumor necrosis factor-related apoptosis-inducing
ligand originally identified in immune cells. The ligand has the capacity to
induce apoptosis after binding to cell surface receptors. To examine TRAIL
expression in murine vascular tissue, we employed in situ hybridization and
immunohistochemistry. In these studies, we found that TRAIL mRNA and protein were
specifically localized throughout the medial smooth muscle cell layer of the
pulmonary artery. Notably, a similar pattern of expression was observed in the
mouse aorta. Consistent with these findings, we found that cultures of primary
human aorta and pulmonary artery smooth muscle cells express abundant TRAIL mRNA
and protein. We also found that these cells and endothelial cells undergo cell
lysis in response to exogenous addition of TRAIL. Last, we confirmed that TRAIL
specifically activated a death program by confirming poly(ADP ribose) polymerase
cleavage. Overall, we believe that these findings are relevant to understanding
the factors that regulate cell turnover in the vessel wall.
PMID- 10781438
TI - Diminished injury in hypotransferrinemic mice after exposure to a metal-rich
particle.
AB - Using the hypotransferrinemic (Hp) mouse model, we studied the effect of altered
iron homeostasis on the defense of the lung against a catalytically active metal.
The homozygotic (hpx/hpx) Hp mice had greatly diminished concentrations of both
serum and lavage fluid transferrin relative to wild-type mice and heterozygotes.
Fifty micrograms of a particle containing abundant concentrations of metals (a
residual oil fly ash) was instilled into wild-type mice and heterozygotic and
homozygotic Hp animals. There was an oxidative stress associated with particle
exposure as manifested by decreased lavage fluid concentrations of ascorbate.
However, rather than an increase in lung injury, diminished transferrin
concentrations in homozygotic Hp mice were associated with decreased indexes of
damage, including concentrations of relevant cytokines, inflammatory cell influx,
lavage fluid protein, and lavage fluid lactate dehydrogenase. Comparable to other
organs in the homozygotic Hp mouse, siderosis of the lung was evident, with
elevated concentrations of lavage fluid and tissue iron. Consequent to these
increased concentrations of iron, proteins to store and transport iron, ferritin,
and lactoferrin, respectively, were increased when assayed by immunoprecipitation
and immunohistochemistry. We conclude that the lack of transferrin in Hp mice did
not predispose the animals to lung injury after exposure to a particle abundant
in metals. Rather, these mice demonstrated a diminished injury that was
associated with an increase in the metal storage and transport proteins.
PMID- 10781439
TI - Protein phosphatase inhibitors arrest cell cycle and reduce branching
morphogenesis in fetal rat lung cultures.
AB - Protein phosphatase 2A (PP2A) is a key signal transduction intermediate in the
regulation of cellular proliferation and differentiation in vitro. However, the
role of PP2A in the context of a developing organ is unknown. To explore the role
of PP2A in the regulation of lung development, we studied the effect of PP2A
inhibition on new airway branching, induction of apoptosis, DNA synthesis, and
expression of epithelial marker genes in whole organ explant cultures of
embryonic (E14) rat lung. Microdissected lung primordia were cultured in medium
containing one of either two PP2A inhibitors, okadaic acid (OA, 0-9 nM) or
cantharidin (Can, 0-3,600 nM), or with the PP2B inhibitor deltamethrin (Del, 0-10
microM) as a control for a PP2A-specific effect for 48 h. PP2A inhibition with OA
and Can significantly inhibited airway branching and overall lung growth. PP2B
inhibition with Del did not affect lung growth or new airway development.
Histologically, both PP2A- and PP2B-inhibited explants were similar to controls.
Increased apoptosis was not the mechanism of decreased lung growth and new airway
branching inasmuch as OA-treated explant sections subjected to the terminal
deoxynucleotidyltransferase dUTP nick end labeling reaction demonstrated a
decrease in apoptosis. However, PP2A inhibition with OA increased DNA content and
5-bromo-2'-deoxyuridine uptake that correlated with a G(2)/M cell cycle arrest.
PP2A inhibition also resulted in altered differentiation of the respiratory
epithelium as evidenced by decreased mRNA levels of the early epithelial marker
surfactant protein C. These findings suggest that inhibition of protein
phosphatases with OA and Can halted mesenchymal cell cycle progression and
reduced branching morphogenesis in fetal rat lung explant culture.
PMID- 10781440
TI - Alterations of nitric oxide synthase expression and activity during rat lung
transplantation.
AB - Decreased nitric oxide (NO) production has been reported during lung
transplantation in patients. To study the effects of ischemia and reperfusion on
endogenous NO synthase (NOS) expression, both an ex vivo and an in vivo lung
injury model for transplantation were used. Donor rat lungs were flushed with
cold low-potassium dextran solution and subjected to either cold (4 degrees C for
12 h) or warm (21 degrees C for 4 h) ischemic preservation followed by
reperfusion with an ex vivo model. A significant increase in inducible NOS and a
decrease in endothelial NOS mRNA was found after reperfusion. These results were
confirmed in a rat single-lung transplant model after warm preservation.
Interestingly, protein contents of both inducible NOS and endothelial NOS
increased in the transplanted lung after 2 h of reperfusion. However, the total
activity of NOS in the transplanted lungs remained at very low levels. We
conclude that ischemic lung preservation and reperfusion result in altered NOS
gene and protein expression with inhibited NOS activity, which may contribute to
the injury of lung transplants.
PMID- 10781441
TI - Ablation of tumor necrosis factor receptor type I (p55) alters oxygen-induced
lung injury.
AB - Hyperoxic lung injury, believed to be mediated by reactive oxygen species,
inflammatory cell activation, and release of cytotoxic cytokines, complicates the
care of many critically ill patients. The cytokine tumor necrosis factor (TNF)
alpha is induced in lungs exposed to high concentrations of oxygen; however, its
contribution to hyperoxia-induced lung injury remains unclear. Both TNF-alpha
treatment and blockade with anti-TNF antibodies increased survival in mice
exposed to hyperoxia. In the current study, to determine if pulmonary oxygen
toxicity is dependent on either of the TNF receptors, type I (TNFR-I) or type II
(TNFR-II), TNFR-I or TNFR-II gene-ablated [(-/-)] mice and wild-type control mice
(WT; C57BL/6) were studied in >95% oxygen. There was no difference in average
length of survival, although early survival was better for TNFR-I(-/-) mice than
for either TNFR-II(-/-) or WT mice. At 48 h of hyperoxia, slightly more alveolar
septal thickening and peribronchiolar and periarteriolar edema were detected in
WT than in TNFR-I(-/-) lungs. By 84 h of oxygen exposure, TNFR-I(-/-) mice
demonstrated greater alveolar debris, inflammation, and edema than WT mice. TNFR
I was necessary for induction of cytokine interleukin (IL)-1beta, IL-1 receptor
antagonist, chemokine macrophage inflammatory protein (MIP)-1beta, MIP-2,
interferon-gamma-induced protein-10 (IP-10), and monocyte chemoattractant protein
(MCP)-1 mRNA in response to intratracheal administration of recombinant murine
TNF-alpha. However, IL-1beta, IL-6, macrophage migration inhibitory factor, MIP
1alpha, MIP-2, and MCP-1 mRNAs were comparably induced by hyperoxia in TNFR-I(-/
) and WT lungs. In contrast, mRNA for manganese superoxide dismutase and
intercellular adhesion molecule-1 were induced by hyperoxia only in WT mice.
Differences in early survival and toxicity suggest that pulmonary oxygen toxicity
is in part mediated by TNFR-I. However, induction of specific cytokine and
chemokine mRNA and lethality in response to severe hyperoxia was independent of
TNFR-I expression. The current study supports the prediction that therapeutic
efforts to block TNF-alpha receptor function will not protect against pulmonary
oxygen toxicity.
PMID- 10781442
TI - Selective restoration of calcium coupling to muscarinic M(3) receptors in
contractile cultured airway myocytes.
AB - We previously demonstrated that after several days of serum deprivation about one
sixth of confluent cultured canine tracheal myocytes acquire an elongated,
structurally and functionally contractile phenotype. These myocytes demonstrated
significant shortening on ACh exposure. To evaluate the mechanism by which these
myocytes acquire responsiveness to ACh, we assessed receptor-Ca(2+) coupling
using fura 2-AM fluorescence imaging and muscarinic receptor expression using
Western analysis. Cells were grown to confluence in 10% fetal bovine serum and
then maintained for 7-13 days in serum-free medium. A fraction of serum-deprived
cells exhibited reproducible intracellular Ca(2+) mobilization in response to ACh
that was uniformly absent from airway myocytes before serum deprivation. The
Ca(2+) response to 10(-4) M ACh was ablated by inositol 1,4,5-trisphosphate
(IP(3)) receptor blockade using 10(-6) M xestospongin C but not by removal of
extracellular Ca(2+). Also, 10(-7) M atropine or 10(-7) M 4-diphenylacetoxy-N
methylpiperidine completely blocked the response to ACh, but intracellular Ca(2+)
mobilization was not ablated by 10(-6) M pirenzepine or 10(-6) M methoctramine.
In contrast, 10(-5) M bradykinin (BK) was without effect in these ACh-responsive
myocytes. Interestingly, myocytes that did not respond to ACh demonstrated robust
increases in intracellular Ca(2+) on exposure to 10(-5) M BK that were blocked by
removal of extracellular Ca(2+) and were only modestly affected by IP(3) receptor
blockade. Serum deprivation increased the abundance of M(3) receptor protein and
of BK(2) receptor protein by two- to threefold in whole cell lysates within 2
days of serum deprivation, whereas M(2) receptor protein fell by >75%. An
increase in M(3) receptor abundance and restoration of M(3) receptor-mediated
Ca(2+) mobilization occur concomitant with reacquisition of a contractile
phenotype during prolonged serum deprivation. These data demonstrate plasticity
in muscarinic surface receptor expression and function in a subpopulation of
airway myocytes that show mutually exclusive physiological and pharmacological
diversity with other cells in the same culture.
PMID- 10781444
TI - Neuraxial blockade for pediatric cardiac surgery: lessons yet to be learned.
PMID- 10781443
TI - Dexamethasone potentiates high-affinity beta-agonist binding and g(s)alpha
protein expression in airway smooth muscle.
AB - Corticosteroids enhance beta-adrenergic responses by actions at both beta
adrenoceptor (beta-AR) and post-beta-AR sites. The present study investigated the
effects of dexamethasone on beta-AR density, high-affinity beta-agonist binding,
G(s)alpha and G(i)alpha protein expression, and cAMP responses in bovine tracheal
smooth muscle (bTSM). Dexamethasone treatment of cultured bTSM cells increased
total beta-AR density 1.6- to 1.9-fold as assessed by the saturation binding of
[(3)H]CGP-12177 and by displacement of radioligand binding with isoproterenol.
Isoproterenol bound to the beta-AR at two sites, a high-affinity site with a
density of 5.9 +/- 1.2 fmol/mg protein and a low-affinity site with a density of
16.9 +/- 1. 0 fmol/mg protein. Dexamethasone increased both high- and low
affinity isoproterenol binding sites to 11.1 +/- 2.2 and 25.9 +/- 2.1 fmol/mg
protein, respectively, without influencing agonist binding affinities.
Dexamethasone also selectively increased G(s)alpha protein levels from 0.99 +/-
0.14 to 1.46 +/- 0.17 microg/mg protein without affecting G(i)alpha levels. The
net effect of these changes was a 1.8-fold increase in maximal isoproterenol
induced cAMP generation in dexamethasone-treated bTSM cells. These findings
provide new insights into the corticosteroid regulation of beta-adrenergic
signaling pathways in airway smooth muscle.
PMID- 10781445
TI - A report of two hundred twenty cases of regional anesthesia in pediatric cardiac
surgery.
AB - The use of regional anesthesia (ie, epidural, spinal, or caudal) has been
reported in a few small series of children undergoing cardiac surgery, but not in
larger studies. In this retrospective, descriptive study, we report the results
of the use of regional anesthesia in 220 pediatric cardiac operations. We
reviewed the records of children receiving a regional anesthetic for
cardiothoracic surgery at Stanford Medical Center between January 1993 and
February 1997. All patients were targeted for early tracheal extubation. A
variety of regional techniques were used. Time to extubation, control of pain,
incidence of respiratory depression and other complications, and length of
hospital stay were determined. There were no deaths. Eighty-nine percent of the
patients were tracheally extubated in the operating room; 4.1% of whom required
reintubation within 24 h. Ninety-five percent +/-2.5% of the patients had pain
scores < or =4.0 at all intervals postoperatively. Adverse effects of regional
anesthesia included emesis (39%), pruritus (10%), urinary retention (7%),
postoperative transient paresthesia (3%), and respiratory depression (1.8%). The
incidence of peridural hematoma was zero. The rate of adverse effects was lower
in the thoracic catheter epidural approach as compared with various caudal,
lumbar epidural, and spinal approaches. Hospital duration of stay was not
effected by the presence of regional anesthetic complications. In this study,
regional anesthesia was safe and effective in the management of pediatric
patients undergoing cardiac surgery.
PMID- 10781446
TI - A retrospective examination of regional plus general anesthesia in children
undergoing open heart surgery.
AB - The use of regional anesthesia in combination with general anesthesia for
children undergoing cardiac surgery is receiving increasing attention from
clinicians. The addition of regional anesthesia may improve clinical outcomes and
decrease costs as a result of the reduced need for postoperative mechanical
ventilation. The goal of this retrospective chart review was to evaluate whether
spinal anesthesia (SAB) or epidural anesthesia (EPID) in combination with general
anesthesia was associated with circulatory stability, satisfactory postoperative
sedation/analgesia, and a low incidence of adverse effects. The medical records
of 50 consecutive children having open heart surgery with SAB or EPID and general
anesthesia between September 1996 and December 1997 were reviewed. We found no
significant differences in the incidence of clinically significant changes in
vital signs, oxygen desaturation, hypercarbia, or vomiting. Patients in the SAB
group received significantly more sedative/analgesic interventions than those in
the EPID group.
PMID- 10781447
TI - Analgesia for pediatric thoracostomy tube removal.
AB - Eutectic mixture of local anesthetics (EMLA; Astra Pharmaceuticals, Wayne, PA)
has been shown to reduce the pain of blood draws in children. We investigated the
use of EMLA versus IV morphine for providing analgesia during chest tube removal
(CTR) in children. One hundred twenty pediatric cardiothoracic surgery patients
were enrolled. Patients were randomly assigned to receive either morphine (0.1
mg/kg up to 10 mg IV 30 min before CTR) or EMLA cream (5 g per chest tube
cutaneously 3 h before CTR). A single, trained observer rated the patient's pain
before, during, and after CTR using a 10-cm visual analog scale. The sites were
evaluated for adverse effect. Methylhemoglobin levels were monitored in infants.
Before CTR, the pain scores of the children who received morphine were rated
lower than those who received EMLA (P < 0.01). During CTR, there was no
difference in the pain score between the morphine or EMLA group. The change from
baseline pain score in the morphine group was significantly larger than in the
EMLA group (P < 0.01). We conclude that EMLA is safe and useful for blunting the
pain of CTR.
PMID- 10781448
TI - Does the addition of fentanyl to bupivacaine in caudal epidural block have an
effect on the plasma level of catecholamines in children?
AB - We evaluated the effect of adding fentanyl to bupivacaine, compared with
bupivacaine alone, on the stress response. The effect was evaluated by
determining blood levels of epinephrine (E) and norepinephrine (NE) in pediatric
patients receiving caudal epidural blocks. Sixty children, 1-8 yr of age,
scheduled for elective herniorrhaphy, were randomly allocated to two groups of 30
patients each. Group A received inhaled anesthesia and caudal epidural block with
bupivacaine 0.25% alone, 1.0 mL/kg. Group B received identical anesthesia;
however, fentanyl 1 microg/kg was added to the bupivacaine in the caudal block.
Blood samples for E and NE plasma levels were drawn at induction time (H(0)), at
the end of surgery (H(1)), and in the postanesthesia care unit (H(2)). In both
groups, there was a significant decrease in the E and NE plasma levels, when
comparing H(1) and H(2) with H(0) within the same group (P < 0.001). There were
no significant differences in the E and NE plasma levels between the two groups
at H(0), H(1), and H(2) (P = 0.5, P = 0.12, P = 0.5, respectively). Pain scores
(modified Children's Hospital of Eastern Ontario Pain Score) were also similar in
both groups (P = 0. 19). This study suggests that adding fentanyl 1 microg/kg to
bupivacaine in the caudal epidural block in children does not influence plasma
levels of E and NE, nor does it improve the analgesic intensity of the caudal
block.
PMID- 10781449
TI - The effects of ropivacaine on sodium currents in dorsal horn neurons of neonatal
rats.
AB - We used a whole cell patch clamp technique to study the effects of ropivacaine on
rat dorsal horn neurons. Under voltage clamp, ropivacaine (10-400 microM)
produced a dose-dependent inhibition of sodium current. From a holding potential
(V(h)) of -80 mV, sodium currents evoked by test pulses to 0 mV were inhibited by
ropivacaine with a mean drug concentration required to produce 50% current
inhibition (IC(50)) value of 117.3 microM, which was more than the value of the
bupivacaine (IC(50) 53.7 microM). The inhibition effect of ropivacaine was also
voltage-dependent. Current evoked from a V(h) of -60 mV was inhibited by
ropivacaine with a mean IC(50) value of 74.3 microM, which was less than that
obtained at the V(h) of -80 mV. The inhibition effect of ropivacaine on sodium
current was use dependent. Repeated activation by a train of depolarizing pulses
(5 Hz, 20 ms) increased the inhibitory effects of ropivacaine. The ratio
amplitudes of the 20th to the first pulse were 91.2% and 71.1%, respectively, in
the absence and presence of ropivacaine (50 microM). Ropivacaine also produced a
significant hyperpolarizing shift of 11 mV in the steady-state inactivation curve
of sodium current. The inhibition of ropivacaine on the sodium channel may
contribute to the mechanism of action of local anesthetics during epidural and
spinal anesthesia.
PMID- 10781450
TI - Cardiopulmonary bypass produces greater pulmonary than systemic proinflammatory
cytokines.
AB - Cardiopulmonary bypass (CPB) impairs pulmonary endothelial injury in part by
increasing expression of adhesion molecules that results in neutrophil influx.
Although numerous proinflammatory cytokines up-regulate these responses, the
extent to which systemic and pulmonary proinflammatory cytokines increase remains
unknown. We therefore examined systemic and pulmonary gene expression and
production of proinflammatory cytokines during CPB. Bronchoalveolar lavage and
peripheral blood sampling were performed just after the induction of anesthesia
and at the end of surgery in 80 patients undergoing CPB. RNA was extracted from
harvested cells and cDNA was synthesized by reverse transcription. The expression
of interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) was
measured by semiquantitative polymerase chain reaction using beta-actin as an
internal standard. We also measured these cytokines in cultured alveolar
macrophages and plasma monocytes in standard medium alone, or in the presence of
lipopolysaccharide. We found 2- to 20-fold increases in gene expression for these
cytokines in both plasma and alveolar leukocytes at the end of surgery. However,
the increases were 4-8 times greater in alveolar than plasma leukocytes. Alveolar
macrophages obtained at the end of surgery produced 1.5-3 times more IL-6, IL-8,
and TNF-alpha than those obtained at the beginning (P < 0.0001). Although plasma
monocytes produced more IL-8 at the end of surgery (P < 0.001), TNF-alpha and IL
6 did not increase. The production of all cytokines was 1.5-3 times greater in
alveolar macrophages obtained at the end of surgery than in plasma monocytes
obtained simultaneously (P < 0.005). Our data thus suggest that CPB provokes a
greater pulmonary than systemic inflammatory response.
PMID- 10781451
TI - Neutrophil number and interleukin-8 and elastase concentrations in
bronchoalveolar lavage fluid correlate with decreased arterial oxygenation after
cardiopulmonary bypass.
AB - Atelectasis is a major cause of decreased arterial oxygenation after
cardiopulmonary bypass (CPB). There is a close relationship between atelectasis
and inflammatory responses. We therefore tested the hypothesis that neutrophil
number and the concentrations of proinflammatory cytokines and elastase in plasma
and bronchoalveolar lavage fluid correlate with changes in arterial oxygenation.
Bronchoalveolar lavage was performed just after the induction of anesthesia and
at the end of surgery in 80 patients undergoing CPB. Peripheral blood was sampled
simultaneously. Arterial oxygenation was quantified by PaO(2)/fraction of
inspired oxygen (FIO(2)) and intrapulmonary shunt (Q(s)/Q(t)). PaO(2)/FIO(2) and
Q(s)/Q(t) decreased significantly at the end of surgery, whereas neutrophil
number, interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, and elastase
concentrations in the lavage fluid increased significantly. The increase in
neutrophil count from the lavage fluid correlated significantly with the
increases in IL-8 and elastase concentrations. The increase in neutrophil number
and IL-8 and elastase concentrations in the lavage fluid correlated significantly
with PaO(2)/FIO(2) and Q(s)/Q(t) at the end of surgery. In contrast, none of the
plasma values correlated with these variables. Significant correlation between
immune mediators and decreased arterial oxygenation suggests that inflammatory
responses in the distal airway are strongly related to a decrease in arterial
oxygenation after CPB.
PMID- 10781452
TI - A prospective, randomized study of goal-oriented hemodynamic therapy in cardiac
surgical patients.
AB - Organ dysfunction and multiple organ failure are the main causes of prolonged
hospital stay after cardiac surgery, which increases resource use and health care
costs. Increased levels of oxygen delivery and consumption are associated with
improved outcome in different groups of postoperative patients. Cardiac surgical
patients are at risk of inadequate perioperative oxygen delivery caused by
extracorporeal circulation and limited cardiovascular reserves. The purpose of
our study was to test whether increasing oxygen delivery immediately after
cardiac surgery would shorten hospital and intensive care unit (ICU) stay. Four
hundred three elective cardiac surgical patients were enrolled in the study and
randomly assigned to either the control or the protocol group. Goals of the
protocol group were to maintain SvO(2) >70% and lactate concentration < or =2.0
mmol/L from admission to the ICU and up to 8 h thereafter. Hemodynamics, oxygen
transport data, and organ dysfunctions were recorded. The median hospital stay
was shorter in the protocol group (6 vs 7 days, P < 0.05), and patients were
discharged faster from the hospital than those in the control group (P < 0.05).
Discharge from the ICU was similar between groups (P = 0. 8). Morbidity was less
frequent at the time of hospital discharge in the protocol group (1.1% vs 6.1%, P
< 0.01). Increasing oxygen delivery to achieve normal SvO(2) values and lactate
concentration during the immediate postoperative period after cardiac surgery can
shorten the length of hospital stay. IMPLICATIONS: Health care economics has
challenged clinicians to reduce costs and improve resource use in cardiac surgery
and anesthesia in a patient population increasing in age and in severity of
disease. Optimizing cardiovascular function to maintain adequate oxygen delivery
during the immediate postoperative period after cardiac surgery can decrease
morbidity and reduce length of hospital stay.
PMID- 10781453
TI - The effect of alpha(2) agonist-induced sedation and its reversal with an alpha(2)
antagonist on organ blood flow in sheep.
AB - We investigated changes in cardiac output and organ blood flow induced by
medetomidine in sheep and determined changes in cardiac output and organ blood
flow after reversal of medetomidine-induced sedation by atipamezole. Eight sheep
were chronically instrumented. Medetomidine was infused IV to target plasma
levels of 0, 0.8, 1.6, 3.2, 6.4, and 12.8 ng/mL for 25 min each, followed by a 5
min infusion of atipamezole. Hemodynamic values and organ blood flow (using
colored microspheres) were measured just before medetomidine infusion (baseline),
at the end of each medetomidine infusion step, and 30 min after the
administration of atipamezole. Medetomidine (12. 8 ng/mL) decreased cardiac
output from 6.3 +/- 1.0 to 3.2 +/- 0.7 L/min (P < 0.0001) and increased systemic
vascular resistance from 1310 +/- 207 to 3467 +/- 1299 dynes. s(-1). cm(-5) (P <
0.0001). Blood flow decreased in the cerebral cortex from 1.29 +/- 0.40 to 0. 66
+/- 0.12 mL. g(-1). min(-1) (P < 0.0001), left ventricle from 2. 11 +/- 0.61 to
1.40 +/- 0.40 mL. g(-1). min(-1) (P < 0.0001), kidney from 8.28 +/- 3.17 to 6.07
+/- 2.65 mL. g(-1). min(-1) (P < 0.0001), skin from 0.09 +/- 0.04 to 0.05 +/-
0.02 mL. g(-1). min(-1) (P < 0. 0001), intestine from 0.56 +/- 0.13 to 0.27 +/-
0.07 mL. g(-1). min(-1) (P < 0.0001), and skeletal muscle from 0.28 +/- 0.15 to
0.04 +/- 0.01 mL. g(-1). min(-1) (P < 0.0001). Blood flow in the liver (hepatic
artery) increased from 0.05 +/- 0.03 to 0.24 +/- 0.16 mL. g(-1). min(-1) (P <
0.0001). After atipamezole infusion, cardiac output and systemic vascular
resistance returned to baseline, but the cerebral cortex, left ventricle, and
renal blood flows remained below baseline at 0.89 +/- 0.22, 1.37 +/- 0.50, and
6.25 +/- 2.76 mL. g(-1). min(-1), respectively; skeletal muscle blood flow
increased above baseline to 0.44 +/- 0.27 mL. g(-1). min(-1), spleen blood flow
decreased below baseline to 1.65 +/- 0.61 mL. g(-1). min(-1) (P < 0.0001), and
liver, intestine, and lung blood flows returned to baseline values. In
conclusion, medetomidine decreased and redistributed organ blood flow in sheep.
Atipamezole reversed the medetomidine-induced hemodynamic changes, but
redistributed blood flow from the brain, heart, and kidney to the skeletal
muscle.
PMID- 10781454
TI - The effects of repeated doses of vasopressin or epinephrine on ventricular
fibrillation in a porcine model of prolonged cardiopulmonary resuscitation.
AB - This study evaluated ventricular fibrillation mean frequency and amplitude to
predict defibrillation success in a porcine cardiopulmonary resuscitation (CPR)
model using repeated administration of vasopressin or epinephrine. After 4 min of
cardiac arrest and 3 min of CPR, 10 pigs were randomly assigned to receive either
vasopressin (early vasopressin: 0.4, 0.4, and 0.8 units/kg, respectively, n = 5)
or epinephrine (early epinephrine: 45, 45, and 200 microg/kg, respectively, n =
5). Another 11 animals were randomly allocated after 4 min of cardiac arrest and
8 min of CPR to receive every 5 min either vasopressin (late vasopressin: 0.4 and
0. 8 units/kg, respectively, n = 5) or epinephrine (late epinephrine: 45 and 200
microg/kg, n = 6). Ventricular fibrillation mean frequency and amplitude on
defibrillation were significantly higher in the vasopressin groups than in the
epinephrine groups, respectively. In vasopressin versus epinephrine animals, mean
frequency immediately before defibrillation was 9.6 +/- 1.5 Hz vs 7. 0 +/- 0.7 Hz
(P < 0.001), mean amplitude was 0.65 +/- 0.26 mV vs 0. 21 +/- 0.14 mV (P < 0.001,
and coronary perfusion pressure was 27 +/- 9 mm Hg vs 8 +/- 4 mm Hg (P <
0.00001), respectively. In contrast to no epinephrine animals, all vasopressin
animals were successfully defibrillated and survived 1 h (P < 0.05). Mean
fibrillation frequency and amplitude predicted successful defibrillation and may
serve as noninvasive markers to monitor continuing CPR efforts. Furthermore,
vasopressin was superior to epinephrine in maintaining these variables above a
threshold necessary for successful defibrillation.
PMID- 10781455
TI - The in vitro effects of antithrombin III on the activated coagulation time in
patients on heparin therapy.
AB - Heparin requires antithrombin III (AT) to achieve anticoagulation, and patients
on continuous small-dose heparin preoperatively experience decreased levels of AT
causing heparin resistance. When this occurs, 2-4 units of fresh frozen plasma (
approximately 1000 units of AT) are often administered to increase AT levels and
restore heparin responsiveness. We evaluated purified human AT concentrate
(Thrombate III; Bayer, Inc., Elkhart, IN) to restore in vitro anticoagulation
responses in patients receiving heparin. Blood samples were obtained from cardiac
surgery patients including 22 patients receiving heparin and 21 patients not
receiving heparin preoperatively. Heparin was added to blood in final
concentrations of 4.1, 5.4, and 6.8 U/mL (equivalent to 300, 400, and 500 U/kg),
and kaolin-activated clotting times (ACTs) were determined with and without AT at
a final concentration of 0.2 units/mL to mimic fresh frozen plasma
administration. The mean duration of preoperative heparin therapy was 4.0 days
(range 2-10 days). AT activity was 69% +/- 9% in patients receiving heparin and
92% +/- 8% in patients not receiving heparin (P < 0.01). Heparin >4.1 U/mL failed
to further increase ACT values in all patients. Attempts to increase ACT in
patients receiving heparin may require supplemental AT administration. Purified
AT even in small doses significantly prolongs the ACT response to heparin.
IMPLICATIONS: In vitro addition of antithrombin III (0.2 U/mL) to heparinized
blood samples (4.1-6.8 units of heparin/mL) from patients on previous heparin
therapy increases sensitivity to supplemental heparin as reflected by
significantly prolonged activated clotting time.
PMID- 10781456
TI - Myocyte endothelin exposure during cardioplegic arrest exacerbates contractile
dysfunction after reperfusion.
AB - Transient left ventricular (LV) dysfunction can occur after cardioplegic arrest.
The contributory mechanisms for this phenomenon are not completely understood. We
tested the hypothesis that exposure of LV myocytes to endothelin (ET) during
simulated cardioplegic arrest would have direct effects on contractile processes
with subsequent reperfusion. LV porcine myocytes were randomly assigned to three
groups: 1) CONTROL: normothermic (37 degrees C) cell media (n = 204); 2)
Cardioplegia: simulated cardioplegic arrest (K(+) 24 mEq/L, 4 degrees C x 2 h)
followed by reperfusion and rewarming with cell media (n = 164); and 3)
Cardioplegia/ ET: simulated cardioplegic arrest in the presence of ET (200 pM)
followed by reperfusion with cell media containing ET (n = 171). Myocyte
contractility was measured by computer-assisted video microscopy. In a subset of
experiments, myocyte intracellular calcium was determined after Fluo-3 (Molecular
Probes, Eugene, OR) loading by digital fluorescence image analysis. Myocyte
shortening velocity was reduced after cardioplegic arrest compared with controls
(52 +/- 2 vs 84 +/- 3 microm/s, respectively; P < 0.05) and was further reduced
with cardioplegic arrest and ET exposure (43 +/- 2 microm/s, P < 0.05).
Intracellular calcium was significantly increased in myocytes exposed to
cardioplegia compared with normothermic control myocytes and was further
augmented by cardioplegia with ET supplementation (P < 0.05). Exposure of the LV
myocyte to ET during cardioplegic arrest directly contributed to contractile
dysfunction after reperfusion. Moreover, alterations in intracellular calcium may
play a role in potentiating the myocyte contractile dysfunction associated with
ET exposure during cardioplegic arrest.
PMID- 10781457
TI - The use of citrated whole blood in thromboelastography.
PMID- 10781458
TI - Reduction of postischemic contractile dysfunction of the isolated rat heart by
sevoflurane: comparison with halothane.
AB - Our aims were to evaluate the effect of sevoflurane on postcardioplegic
functional recovery of the isolated rat heart including the role of the adenosine
triphosphate regulated potassium (K(ATP)) channels and to compare the
cardioprotective effects of equipotent concentrations of halothane and
sevoflurane. Isolated perfused rat hearts were subjected to 45 or 60 min
normothermic cardioplegic arrest and 30 min reperfusion. Sevoflurane (0.9% and 1.
7%), halothane (0.4% and 0.8%), or sevoflurane (0.9%) plus glibenclamide (10
microM) (a K(ATP) channel blocker) were administered at different time intervals.
Measurements of mechanical activity were made before and after arrest. Function
during reperfusion after cardioplegic arrest was significantly depressed in both
untreated and treated hearts. However, sevoflurane administered both before and
after arrest, or before only, significantly improved functional recovery after 45
min of cardioplegia. This protective effect was abolished by simultaneous
administration of glibenclamide, suggesting a role of the K(ATP) channel.
Sevoflurane was as effective as halothane in improving postcardioplegic
functional performance. After 45 min of arrest, hearts exposed to either
anesthetic at both concentrations had a significantly higher work performance on
discontinuation of their administration than untreated controls. After 60 min of
arrest, neither anesthetic elicited protection.
PMID- 10781459
TI - Antiphospholipid syndrome and cardiac surgery: management of anticoagulation in
two patients.
PMID- 10781460
TI - Postoperative analgesia for outpatient arthroscopic knee surgery with
intraarticular clonidine and/or morphine.
AB - Both clonidine, an alpha(2) agonist, and morphine, an opioid agonist, provide
enhanced patient analgesia after arthroscopic knee surgery when administered via
the intraarticular (IA) route. Clonidine potentiates morphine analgesia in the
animal model. We designed this study to determine whether clonidine or morphine
results in better analgesia and whether their combination would provide superior
analgesia to either drug alone. We evaluated 60 patients undergoing arthroscopic
knee meniscus repair under local anesthesia with sedation. After surgery,
patients were randomized into four IA groups: Group B received 30 mL 0.25%
bupivacaine; Group BC received 30 mL 0.25% bupivacaine and clonidine 1 microg/kg;
Group BM received 30 mL 0.25% bupivacaine and morphine 3 mg; and Group BCM
received 30 mL 0.25% bupivacaine, clonidine 1 microg/kg, and morphine 3 mg. This
study revealed a significant benefit from the individual IA administration of
both clonidine and morphine. The combination of these drugs resulted in decreased
postoperative pain and analgesic use, as well as an increased analgesic duration
compared with either drug alone. We conclude that IA clonidine and morphine
improved comfort compared with either drug alone in patients undergoing knee
arthroscopy.
PMID- 10781461
TI - The effect of ketorolac on recovery after anorectal surgery: intravenous versus
local administration.
PMID- 10781462
TI - Remifentanil infusion facilitates early recovery for obese outpatients undergoing
laparoscopic cholecystectomy.
PMID- 10781463
TI - Depth of anesthesia and bispectral index monitoring.
PMID- 10781465
TI - Novel analgesic adjuncts for brachial plexus block: a systematic review.
AB - This article reviews current evidence for the efficacy of adding novel analgesic
adjuncts to brachial plexus block, the goal of which is to prolong analgesic
effect without the disadvantage of systemic side effects or prolonged motor
block. It may also allow for a reduction in the total dose of local anesthetic
used. Novel adjuncts studied to date include opioids, clonidine, neostigmine, and
tramadol. Twenty-four studies were reviewed and assessed by using specific
inclusion criteria, and only those studies satisfying these criteria were
included in the final assessment. Satisfactory studies were then assessed for
inclusion of a systemic control group to determine peripheral effect, as opposed
to possible systemic effect, of an adjunct administered peripherally. Evidence
regarding the analgesic benefit of opioid adjuncts remains equivocal and more
evidence is required before their routine use can be recommended. Clonidine
appears to have significant analgesic benefit and to cause minimal adverse
effects when used in doses up to 150 microg. Data regarding other drugs, such as
tramadol and neostigmine, are not sufficient to allow for any recommendations,
and further studies are required.
PMID- 10781464
TI - Sedation with sufentanil and midazolam decreases pain in patients undergoing
upper limb surgery under multiple nerve block.
AB - Multiple nerve blocks may be painful and a source of discomfort. We assessed the
efficacy of sufentanil 5 microg combined with midazolam 1 mg in decreasing pain
in outpatients after a midhumeral multiple nerve stimulation technique. Visual
analog scores for pain were significantly lower in those patients who received
sedation before the block, both at the time of block performance (14 +/- 1 vs 27
+/- 2 mm, P < 0.0001) and at discharge (11 +/- 1 vs 24 +/- 2 mm, P < 0. 0001). We
conclude that the association of sufentanil and midazolam produced minimal
sedation while significantly reducing pain experienced by patients undergoing
multiple nerve stimulation.
PMID- 10781466
TI - A decrease in seizure susceptibility to lidocaine in kindled epileptic rats.
AB - Lidocaine induces electroencephalographic seizures and generalized convulsions at
large doses. It is possible that epileptic patients are more susceptible to the
proconvulsant effect of lidocaine. Using a kindling model of epilepsy, we
examined whether the seizure susceptibility to lidocaine increases in epileptic
rats. Kindled epileptic rats were prepared by repeated, initially subconvulsive,
electrical stimulations applied to the amygdala for 9-14 days through a
chronically implanted electrode, resulting in the establishment of a long-lasting
epileptic focus. Unexpectedly, kindled rats had significantly less susceptibility
to the proconvulsant action of IV lidocaine. Lidocaine-induced convulsions were
observed in 11%, 75%, and 77% of control rats at 7.5, 10.0, and 12.5 mg/kg,
respectively, compared with 0%, 25%, and 37% of amygdala-kindled rats,
respectively. We also demonstrated that small doses of lidocaine suppressed
kindled seizures in a dose-dependent manner. We conclude that the critical
mechanisms underlying lidocaine-induced seizures differ from the mechanisms
underlying kindled epileptogenesis. Furthermore, the establishment of a kindled
epileptic focus decreases susceptibility to the proconvulsant action of
lidocaine.
PMID- 10781467
TI - Determining minimum effective anesthetic concentration of hyperbaric bupivacaine
for spinal anesthesia.
AB - We determined the minimum effective anesthetic concentration (MEAC) of
bupivacaine for spinal anesthesia, defined as the median effective concentration
at which a spinal anesthetic produces surgically equivalent anesthesia within 20
min of administration in 50% of human subjects. Two doses of spinal bupivacaine
(7.5 mg and 10 mg) were administered to 45 volunteers (19-39 yr) in a randomized,
double-blinded fashion. Hyperbaric bupivacaine solutions of 0.1% to 0.75%
containing 8.25% dextrose were administered intrathecally and MEAC established by
using the Dixon's up-and-down method. Complete anesthesia was defined as: 1)
pinprick anesthesia at or higher than T12; 2) anesthesia to transcutaneous
tetanic electric stimulation (50 Hz at 60 mA for 5 s) in the knees; and 3)
complete leg paralysis, all occurring in both lower extremities within 20 min of
intrathecal injection. We found that the MEAC of spinal bupivacaine was 0.43%
(95% confidence interval 0.24-0.62) when 10 mg was administered. At this dose, a
concentration as low as 0.1% could provide complete anesthesia, but consistent
blockade was obtained only with the 0.7% solution. The 7.5-mg dose failed to
provide complete anesthesia consistently, even in the presence of 0.75%
(maximum). The current commercially available 0.75% concentration of hyperbaric
bupivacaine seems to be clinically optimal when 10 mg is used if complete
bilateral lower extremity blockade is desired.
PMID- 10781468
TI - The effect of diclofenac on the expression of spinal cord c-fos-like
immunoreactivity after ischemia-reperfusion-induced acute hyperalgesia in the rat
tail.
AB - Ischemia-reperfusion of the rat tail for 20 min induces local acute hyperalgesia
of approximately 1-h duration. We studied how this stimulus affected the
expression of c-fos-like immunoreactivity (c-fos-LI) labeling of neurons of the
sacral spinal cord, and how diclofenac pretreatment influenced the outcome. After
ischemia, the number of c-fos-LI-labeled neurons was significantly increased when
assessed at 60, 90, and 120 min after reperfusion (to 183%, 283%, and 164% of
control, respectively; all P < 0.01). At 90 min, the number of regional c-fos-LI
labeled neurons was increased to 585% in laminae I-II, 183% in laminae III-IV,
270% in laminae V-X, and 286% in total, compared with respective control values
(all P < 0.01). After diclofenac pretreatment (subcutaneous 40 mg/Kg, 30 min
before insult) the number of c-fos-LI-labeled neurons at 90 min was increased to
424% in laminae I-II, 150% in laminae III-IV, 142% in laminae V-X, and 183% in
total (all P < 0.01). Thus diclofenac pretreatment partially prevented the insult
induced increase in total and regional neuronal c-fos-LI. This acute nociceptive
model involves only natural algogens. However, the results were similar to acute
chemically induced or chronic adjuvant induced arthritic inflammatory pain models
in which increases in c-Fos were partially inhibited by nonsteroidal
antiinflammatory drugs.
PMID- 10781470
TI - Antagonism of antinociception produced by intrathecal clonidine by ketorolac in
the rat: the role of the opioid system.
AB - The management of severe pain may require "balanced analgesia," involving the use
of analgesics with different modes of action. Clonidine, an alpha(2)
adrenoreceptor agonist produces analgesia by itself as well as when given with
morphine and local anesthetics. Ketorolac is indicated for the management of
moderately severe acute pain and causes analgesia equivalent to morphine. This
study was designed to investigate whether the addition of ketorolac promotes
antinociception produced by intrathecal administration of clonidine in male
Sprague-Dawley rats. Intrathecal injection of clonidine (1-30 microg) induced a
dose-dependent increase in antinociception as measured by the tail flick (TF) and
hot plate tests. Ketorolac alone (150-600 microg) increased the antinociception
by 50%-60% only in the TF test. Ketorolac (10 microg) decreased clonidine (10
microg)-induced antinociception from 69.1% +/- 7.8% to 23.5% +/- 1. 6% (P < 0.05)
in the TF test and 35.7% +/- 4.7% to 4.5% +/- 0.1% (P < 0.05) maximum possible
effect in the hot plate test. Ketorolac also antagonized the effect of 30 microg
of clonidine. The opioid receptor antagonist naloxone antagonized the
antinociceptive effect of clonidine and ketorolac, indicating the involvement of
the opioid system in the antinociception produced by clonidine or ketorolac.
However, neither clonidine nor ketorolac (10(-8) to 10(-3) M) inhibited the
binding of specific ligands to mu-, delta-, and kappa-opioid receptors,
indicating a lack of direct interaction of clonidine and ketorolac with opioid
receptors. These results suggest that intrathecal injection of ketorolac
antagonizes the antinociception produced by clonidine.
PMID- 10781469
TI - Antinociceptive action of epidural K+(ATP) channel openers via interaction with
morphine and an alpha(2)- adrenergic agonist in rats.
AB - Potassium (K(+)) channels may play some role in the analgesic actions of mu
opioid agonists and alpha(2)-adrenergic agonists (alpha(2) agonists). We examined
whether the adenosine triphosphate-sensitive K(+)(K(+)(ATP)) channel openers,
levcromakalim and nicorandil, (given epidurally), might have antinociceptive
effects in a tail flick test in adult male Sprague-Dawley rats implanted with a
lumbar epidural catheter. The interactions with morphine and an alpha(2) agonist
were also examined. The epidural administration of levcromakalim (10 microg, 100
microg) or nicorandil (10 microg, 100 microg) alone did not produce
antinociception, but 100 microg levcromakalim or nicorandil did potentiate the
antinociceptive effect induced by epidural morphine. Epidural glibenclamide (10
microg), a K(+)(ATP) channel blocker, or naloxone (10 microg) antagonized this
potentiation. Systemic administration of levcromakalim or nicorandil (at the same
dose as that given into the epidural space) did not potentiate the epidural
morphine-induced analgesia. A combination of epidural dexmedetomidine (1 microg)
and morphine (1 microg) (each at a subantinociceptive dose) had a significant
antinociceptive effect, and epidural glibenclamide (10 microg) partly antagonized
this antinociception. These data suggest that levcromakalim and nicorandil
potentiate the analgesic action of both morphine and dexmedetomidine, probably
via an activation of K(+)(ATP) channels at the spinal cord level.
PMID- 10781471
TI - The combined effect of age and premedication on the propofol requirements for
induction by target-controlled infusion.
AB - In this prospective study, we evaluated the combined influence of age and
premedication on propofol requirements for the induction of anesthesia and their
hemodynamic effects using a target-controlled infusion. We studied 180 patients
separated into three age groups: 20-39 yr, 40-59 yr, and more than 59 yr. In each
age group, patients were randomly allocated to receive either no premedication (n
= 20), fentanyl (2 microg/kg) (n = 20), or midazolam (0.03 mg/kg) plus fentanyl
(2 microg/kg) (n = 20). The concentration of propofol targeted for the induction
was 5 microg/mL, to be reached in 2 min. The dose, time, and predicted plasma
concentration of propofol at hypnosis were measured. Baseline and postinduction
heart rate and arterial blood pressure were registered. Computer simulation was
used to calculate the effect site propofol concentration at hypnosis. The
concentration of propofol, effect site propofol concentration, time, and
induction dose and their hemodynamic effect were significantly different among
groups with respect to age and premedication. The combined effect of the two
factors was additive, but without significant interaction. The propofol
requirements were significantly less in the midazolam-fentanyl groups, regardless
of age, and among the premedicated patients older than 60 yr compared with the
other age groups. We conclude that the combined effect of age and premedication
on the requirements of propofol for the induction of anesthesia should be
considered when the concentration is targeted with a target-controlled infusion
system.
PMID- 10781472
TI - Intrathecal fentanyl is superior to intravenous ondansetron for the prevention of
perioperative nausea during cesarean delivery with spinal anesthesia.
AB - This study compares intrathecal (IT) fentanyl with IV ondansetron for preventing
intraoperative nausea and vomiting during cesarean deliveries performed with
spinal anesthesia. Thirty healthy parturients presenting for elective cesarean
delivery with standardized bupivacaine spinal anesthesia were randomized to
receive 20 microg IT fentanyl (Group F) or 4 mg IV ondansetron (Group O) by using
double-blinded methodology. At eight specific intervals during the surgery, a
blinded observer questioned the patient about nausea (1 = nausea, 0 = no nausea),
observed for the presence of retching or vomiting (1 = vomiting or retching, 0 =
no vomiting or retching), and recorded a verbal pain score (0-10, 0 = no pain, 10
= worst pain imaginable). Cumulative nausea, vomiting, and pain scores were
calculated as the sum of the eight measurements. Intraoperative nausea was
decreased in the IT fentanyl group compared with the IV ondansetron group: the
median (interquartile range) difference in nausea scores was 1 (1, 2), P = 0.03.
The incidence of vomiting and treatment for vomiting was not different (P = 0.7).
The IT fentanyl group had a lower cumulative perioperative pain score than the IV
ondansetron group; the median difference in the cumulative pain score was 12 (8,
16) (P = 0.0007). The IT fentanyl group required less supplementary
intraoperative analgesia. The median difference in the cumulative fentanyl dose
was 100 (75, 100) microg fentanyl, (P = 0.0002).
PMID- 10781473
TI - Alfentanil given immediately before the induction of anesthesia for elective
cesarean delivery.
AB - Opioids are routinely omitted at the induction of general anesthesia for cesarean
delivery because of concerns about neonatal respiratory depression. The
subsequent unmodified maternal stress response to tracheal intubation reduces
placental perfusion. The short-acting opioid alfentanil may afford advantages at
the induction, without subsequent neonatal depression. In this double-blinded
study of elective cesarean deliveries, 40 patients were allocated randomly to
receive either alfentanil 10 microg/kg (n = 18) or placebo (n = 22), 1 min before
the induction of anesthesia with thiopental 4 mg/kg and succinylcholine 1.5
mg/kg. Anesthesia was maintained with 50% nitrous oxide, 0.5% isoflurane in
oxygen, and atracurium. Neonates were assessed by using Apgar scores, Neurologic
and Adaptive Capacity Scores, and umbilical cord blood gas and catecholamine
analysis. After intubation, mothers receiving alfentanil had a smaller increase
in mean arterial blood pressure, (11 +/- 15 vs 31 +/- 13 mm Hg, P < 0.001) and
lower plasma norepinephrine concentrations, (336 +/- 152 vs 486 +/- 241 pg/mL, P
< 0.05). Neonates in the alfentanil group had greater umbilical arterial oxygen
tensions (27.8 +/- 7.0 vs 22.6 +/- 7.4 mm Hg), slightly reduced Apgar scores
(both P < 0.05), but similar Neurologic and Adaptive Capacity Scores. One neonate
in the alfentanil group required naloxone. The maternal stress response was
attenuated in the alfentanil group but at the cost of early neonatal depression.
However, all neonates should be monitored for possible immediate, but transient,
respiratory depression.
PMID- 10781474
TI - Tension pneumothorax in a parturient undergoing cesarean delivery.
PMID- 10781475
TI - Mental status change and aphasia after labor analgesia with intrathecal
sufentanil/bupivacaine.
PMID- 10781476
TI - The effects of pentobarbital, isoflurane, and propofol on immediate-early gene
expression in the vital organs of the rat.
AB - General anesthetics are known to transiently increase the expression of messenger
ribonucleic acids (mRNAs) of immediate-early genes in the brain. We investigated
whether the expression of two immediate-early genes in vital organs were
modulated by various anesthetics. Inhaled isoflurane (n = 20), intraperitoneal
pentobarbital (n = 20), and IV propofol (n = 20) were administered to male
Sprague-Dawley rats, and five from each group were decapitated at 5, 30, 60, or
120 min after the induction of anesthesia. Control, nonanesthetized rats (n = 5)
were handled gently and then decapitated. Reverse transcriptase-polymerase chain
reactions were performed on total RNA from samples of the brain, heart, liver,
and kidney to detect the expressions of c-fos and c-jun mRNAs. As internal
control, cyclophilin mRNA was amplified simultaneously. The products were
separated by electrophoresis, and the optical density of the bands was
quantified. The expression of c-fos mRNA was transiently increased in the brain,
and more strikingly and for longer times, in the kidney with all three
anesthetics; the expression of c-fos mRNA was decreased in the heart with
isoflurane and pentobarbital and increased in the liver with isoflurane and
propofol. The expression of c-jun mRNA was increased in the heart, liver, and
kidney with isoflurane, increased in the heart and kidney with pentobarbital,
increased in the heart, liver, and kidney with propofol, and decreased in the
brain with pentobarbital. Our results suggest that the appropriate anesthetics to
be used to anesthetize animals differ in accord with the target organs in which
the expressions of immediate-early genes in response to stimuli were studied.
PMID- 10781477
TI - Dual action of isoflurane on the gamma-aminobutyric acid (GABA)-mediated currents
through recombinant alpha(1)beta(2)gamma(2L)-GABA(A)-receptor channels.
AB - Isoflurane (ISO) increased the agonist-induced chloride flux through the gamma
aminobutyric acid A receptor (GABA(A)R). This may reflect an anesthetic-induced
increase in the apparent agonist affinity. A dual effect of anesthetics was
postulated for both the nicotinic acetylcholine receptor (nAChR) and the
GABA(A)R. We tested the hypothesis that, in addition to a blocking effect, ISO
increases gamma-aminobutyric acid (GABA)-gated currents through recombinant
GABA(A)R channels. HEK293 cells were transfected with rat cDNA for
alpha(1),beta(2),gamma(2L) subunits. Currents elicited by 1 mM or 0. 01 mM GABA,
respectively, alone, or with increasing concentrations of ISO, were recorded by
using standard patch clamp techniques. ISO reduced the peak current elicited by 1
mM GABA. Currents induced by 0.01 mM GABA were potentiated by small ISO (twofold
at 0.5 mM ISO) and inhibited by larger concentrations. Withdrawal of ISO and GABA
induced rebound currents, suggesting an open-channel block by ISO. These currents
increased with increasing concentrations of ISO. At large concentrations of ISO,
the inhibitory effect predominated and was caused by, at least partly, an open
channel block. At small concentrations of ISO, potentiation of the GABA-gated
currents was more prominent. This dual action of ISO indicates different binding
sites at the GABA(A)R. The balance between potentiation and block depends on the
concentrations of both ISO and GABA.
PMID- 10781478
TI - An alternate method for estimating the dose-response relationships of
neuromuscular blocking drugs.
AB - Slopes of the dose-response relationships for all available neuromuscular
blocking drugs appear to be essentially parallel and to approximate a log
dose/logit value of 4.75. We tested the possibility of estimating both 50%
effective dose (ED(50)) and 95% effective dose (ED(95)) values from a single dose
response data point when that slope is postulated. We compared the ED(50) and
ED(95) values of rocuronium and succinylcholine calculated by using traditional
log-dose/logit regression analysis with the same values obtained by averaging
individual estimates of potency as determined by using the Hill equation. After
the induction of anesthesia (propofol/alfentanil), tracheal intubation was
accomplished without the administration of neuromuscular blocking drugs.
Anesthesia was maintained with nitrous oxide and propofol. The evoked
electromyographic response to 0.10-Hz single stimuli was continuously recorded.
After baseline stabilization, a single IV bolus of succinylcholine (0.08-0.26
mg/kg, n = 50) or rocuronium (0. 13-0.30 mg/kg, n = 40) was administered and the
peak effect noted. By using log-dose/logit regression analysis, we calculated
ED(50) and ED(95) values for rocuronium of 0.17 and 0.33 mg/kg and 0.14 and 0.27
mg/kg for succinylcholine. When potency was calculated from the Hill equation,
the resultant ED(50) and ED(95) values did not differ by more than +/-4% from
those obtained by using regression analysis. Averaging of single-dose estimates
of neuromuscular potency provides a useful adjunct and reasonable alternative to
conventional regression analysis.
PMID- 10781479
TI - Hepatic blood flow and function in elderly patients undergoing laparoscopic
cholecystectomy.
AB - Laparoscopic cholecystectomy (LC) has been widely accepted as an alternative to
laparotomy and has many advantages, including short hospital stay and very
limited surgical invasion. However, this procedure may impair hepatic function in
elderly patients because high pressure is maintained in the peritoneal cavity for
an extended period. We observed the effect of pneumoperitoneum on the middle
hepatic venous blood flow (MHVBF) in elderly patients undergoing LC. LC patients
were anesthesized with inhaled and epidural anesthesia, after which MHVBF was
continuously measured by transesophageal echocardiography. MHVBF decreased
significantly during a period of high intraperitoneal pressure, and recovery of
MHVBF after deflation was significantly lower in elderly patients (65-75 yr), but
not in younger patients (24-62 yr). In contrast, MHVBF remained almost constant
in elderly patients during open cholecystectomy, and thus was significantly
different from that in patients who underwent LC with pneumoperitoneum.
Laparoscopic cholecystectomy may impair hepatic function in elderly patients
because high pressure is maintained in the peritoneal cavity for an extended
period.
PMID- 10781480
TI - A comparison of hemodynamic changes after endotracheal intubation by using the
lightwand device and the laryngoscope in normotensive and hypertensive patients.
AB - We compared the effects of the lightwand technique on hemodynamic responses, time
to-intubation, number of attempts, and complications during tracheal intubation
with those of direct-vision laryngoscopy in normotensive (LN and TN group; n =
20, respectively) and hypertensive (LH and TH group; n = 20, respectively)
patients. Lightwand or laryngoscopic oral endotracheal intubation was performed
after the induction of anesthesia with fentanyl and propofol and muscle
relaxation with vecuronium. Systolic blood pressure, diastolic blood pressure,
and heart rate were recorded, and the change from "before intubation" to
"immediately after intubation" (DeltaP) in each variable was calculated. In
normotensive patients, significantly larger DeltaP in systolic blood pressure was
observed in the LN group than in the TN group (P < 0. 05). In hypertensive
patients, there were no significant differences between the LH group and the TH
group in DeltaP after intubation. The time-to-intubation and number of attempts
in the lightwand groups were significantly longer and more frequent than those in
the laryngoscope groups (P < 0.05). The number of patients who complained of
hoarseness was larger in the lightwand groups than in the laryngoscope groups (P
< 0.05). We conclude that the lightwand technique significantly attenuates
hemodynamic changes after intubation in comparison with the laryngoscopic
technique in normotensive patients. However, in hypertensive patients, there is
no difference in hemodynamic changes between the two techniques.
PMID- 10781481
TI - Intravenous chloroprocaine attenuates hemodynamic changes associated with direct
laryngoscopy and tracheal intubation.
AB - We compared the effects of an IV administration of chloroprocaine and lidocaine
on circulatory responses associated with endotracheal intubation. Thirty patients
were randomly allocated to receive normal saline (placebo), lidocaine (1.5
mg/kg), or preservative-free chloroprocaine (4.5 mg/kg) 45 s before endotracheal
intubation. Blood pressures and heart rate and rhythm were recorded before
laryngoscopy and at 0.5, 1, 1.5, 2, 3, and 5 min after intubation. Blood samples
were analyzed for catecholamine and chloroprocaine concentrations. Chloroprocaine
reduced increases in blood pressure in response to intubation when compared with
patients receiving normal saline and lidocaine. Systolic blood pressures at 0.5
and 1 min after intubation were significantly lower in the chloroprocaine group
when compared with both the control and lidocaine groups (P < 0.05). Diastolic
and mean blood pressures were significantly lower in the chloroprocaine group at
all time points until 5 min after intubation (P < 0.05). Chloroprocaine and, to a
lesser degree, lidocaine, produced marked attenuation of intubation-induced
increases in plasma concentration of epinephrine and norepinephrine. Plasma
concentrations of norepinephrine were significantly smaller in the chloroprocaine
group at 0.5, 1, and 1.5 min, and plasma concentrations of epinephrine were
significantly smaller at 0.5 after intubation when compared with control and
lidocaine groups (P < 0.05). Measurable concentrations of chloroprocaine were
recorded in plasma samples for 2 min after its administration. No adverse
chloroprocaine effects (i.e., circulatory disturbances, venous irritation) were
detected. The IV administration of chloroprocaine effectively blunted
cardiovascular response produced by laryngoscopy and endotracheal intubation, and
this effect was more pronounced when compared with IV lidocaine.
PMID- 10781482
TI - Inhaling nitrous oxide reduces the induction dose requirements of propofol.
AB - Inhaling nitrous oxide (N(2)O) before propofol induction appears to decrease
propofol usage. To investigate the efficacy of N(2)O as a component of the drugs
used to induce anesthesia, the effect of inhaling a N(2)O:oxygen (O(2)) mixture
on the dose of propofol required to induce anesthesia was determined in a double
blinded manner. We randomized 117 unpremedicated patients scheduled for elective
surgery into three groups. Group FN received 1 microg/kg fentanyl and breathed 4
L/min N(2)O + 2 L/min O(2). Group PN received placebo and breathed 4 L/min N(2)O
+ 2 L/min O(2). Group FO received 1 microg/kg fentanyl and breathed 6 L/min O(2).
Propofol was infused at 20 mg/min after 1 min of gas mixture inhalation, and the
infusion stopped when there was loss of response to verbal command. The mean (SD)
propofol dose was 0.75 (0.30), 0.84 (0.26), and 1.33 (0.51) mg/kg, and the
induction time 133 (57), 142 (47), and 226 (78) s for Groups FN, PN, and FO,
respectively. We conclude that inhalation of 66% N(2)O in O(2) 1 min before the
IV induction of anesthesia with propofol at 20 mg/min, reduces the induction dose
of propofol by 44% and decreases the time required for the induction of
anesthesia (P < 0.001).
PMID- 10781483
TI - The onset time of rocuronium is slowed by esmolol and accelerated by ephedrine.
AB - Administration of ephedrine prior to rocuronium decreases the onset time of
neuromuscular blockade from rocuronium by 26%. This effect was attributed to a
increased cardiac output. If so, beta adrenergic-blocking drugs, which decrease
cardiac output, should prolong the onset time of rocuronium. In a double-blind
study, 60 patients were randomly assigned to three groups (n = 20) to receive
either 70 microg. kg(-1) of ephedrine, 0.5 mg. kg(-1) esmolol or placebo, 30 s
before induction of anesthesia. Onset time of rocuronium was defined as the time
from the end of its injection to disappearance of all four twitches of the train
of-four. The onset time of rocuronium was significantly shorter after ephedrine
(22%) and longer after esmolol (26%), as compared to placebo. No differences were
observed among the three groups with regard to heart rate, systolic, diastolic or
mean blood pressure. We concluded that a dose of 0.5 mg. kg(-1) of esmolol
significantly prolongs the onset time of rocuronium with minimal hemodynamic
changes.
PMID- 10781484
TI - The laryngeal tube: a new simple airway device.
PMID- 10781485
TI - An AIDS-associated cause of the difficult airway: supraglottic Kaposi's sarcoma.
PMID- 10781486
TI - An unusual cause of respiratory distress: live leech in the larynx.
PMID- 10781487
TI - Cardiovascular anesthesiology in the 1990s and beyond.
PMID- 10781488
TI - Pediatric anesthesia: where do we go from here?
PMID- 10781489
TI - Ambulatory anesthesia advances into the new millennium.
PMID- 10781490
TI - Intensive care medicine 2000: first signs of maturity?
PMID- 10781491
TI - Neuroanesthesia 2000.
PMID- 10781492
TI - Obstetric anesthesiology in the new millennium.
PMID- 10781493
TI - Regional anesthesia and pain management: reviewing the past decade and predicting
the future.
PMID- 10781494
TI - Femoral nerve palsy after femoral vein cannulation.
PMID- 10781495
TI - Quality of medical information on the Internet.
PMID- 10781496
TI - Curling the tip anteriorly does not facilitate laryngeal mask insertion.
PMID- 10781497
TI - Intraoperative variables and morbidity and mortality after coronary artery bypass
surgery.
PMID- 10781498
TI - Five-grade scoring system is still confusing: does ASE/SCA set up a double
standard?
PMID- 10781499
TI - Postdural puncture headache (PDPH) and combined spinal-epidural (CSE)
PMID- 10781500
TI - An economical substitute for Ayre's T piece.
PMID- 10781501
TI - Hidden damage to a reinforced LMA-Fastrach endotracheal tube.
PMID- 10781502
TI - Epidural hematoma after catheter removal.
PMID- 10781504
TI - Immunology and thyroid ophthalmopathy: where will the footprints lead us?
PMID- 10781503
TI - Ups and downs of optokinetic nystagmus.
PMID- 10781505
TI - Sympathetic ophthalmia risk following vitrectomy: should we counsel patients?
PMID- 10781506
TI - Abnormal vertical optokinetic nystagmus in infants and children.
AB - AIMS: To determine if testing vertical optokinetic nystagmus (VOKN) has a role in
the clinical assessment of infants and children. METHODS: A large field
projection system was developed with which optokinetic nystagmus (OKN) could be
stimulated in any direction. Gross abnormalities in the response were detected
simply by observation. RESULTS: VOKN was tested in 144 children using this OKN
projection system. 26 of these children had abnormal VOKN; 13 had a vertical
saccade initiation failure "ocular motor apraxia" (in either direction, up/down,
or in both) and 13 had absent VOKN (in either direction, up/down, or in both).
Nine of the children with an up and/or down vertical saccade initiation failure
(VSIF) had a neurometabolic disease (two had Niemann-Pick disease type C, five
had Gaucher disease type III, one had Gaucher disease type II, and one had
Gaucher disease type I). Five children with a VSIF had an abnormality identified
by a magnetic resonance imaging (MRI) scan of the brain. In two of these children
there was a focal lesion of the rostral midbrain. In 11 of the children with
absent up and/or down VOKN an MRI scan revealed an abnormality. This involved the
brainstem and/or the cerebellum in 10. Absent up and/or down VOKN was found in
association with Joubert syndrome, Leigh disease, and cerebral palsy. CONCLUSION:
VOKN testing has a useful role in detecting neurological abnormalities in infants
and children. Detection of abnormal VOKN should indicate further investigations
for a neurometabolic disease or an abnormality involving the cortex, brainstem,
and/or cerebellum. Abnormal VOKN but normal horizontal OKN is highly suggestive
of a rostral midbrain lesion.
PMID- 10781507
TI - The Bristol shared care glaucoma study: outcome at follow up at 2 years.
AB - AIM: To examine the outcome of care for patients with glaucoma followed up by the
hospital eye service compared with those followed up by community optometrists.
METHODS: A randomised study with patients allocated to follow up by the hospital
eye service or community optometrists was carried out in the former county of
Avon in south west England. 403 patients with established or suspected primary
open angle glaucoma attending Bristol Eye Hospital and meeting defined inclusion
and exclusion criteria were studied. The mean number of missed points on visual
field testing in the better eye (using a "better/worse" eye analysis) in each
group were measured. The visual field was measured using the Henson semiautomated
central field analyser (CFA 3000). Measurements were made by the research team on
all patients at baseline before randomisation and again 2 years after
randomisation. The mean number of missed points on visual field testing in the
worse eye, mean intraocular pressure (mm Hg), and cup disc ratio using a
"better/worse" eye analysis in each group at 2 years were also measured.
Measurements were made by the research team on all patients at baseline before
randomisation and again 2 years after randomisation. An analysis of covariance
comparing method of follow up taking into account baseline measurements of
outcome variables was carried out. Additional control was considered for age,
sex, diagnostic group (glaucoma suspect/established primary open angle glaucoma),
and treatment (any/none). RESULTS: From examination of patient notes, 2780
patients with established or suspected glaucoma were identified. Of these, 752
(27.1%) fulfilled the entry criteria. For hospital and community follow up group
respectively, mean number of missed points on visual field testing at 2 year
follow up for better eye was 7.9 points and 6.8 points; for the worse eye 20.2
points and 18.4 points. Similarly, intraocular pressure was 19.3 mm Hg and 19.3
mm Hg (better eye), and 19.1 mm Hg and 19.0 mm Hg (worse eye); cup disc ratio at
2 year follow up was 0.72 and 0.72 (better eye), and 0.74 and 0.74 for hospital
and community follow up group respectively. No significant differences in any of
the key visual variables were found between the two groups before or after
adjusting for baseline values and age, sex, treatment, and type of glaucoma.
CONCLUSIONS: It is feasible to set and run shared care schemes for a proportion
of patients with suspected and established glaucoma using community optometrists.
After 2 years (a relatively short time in the life of a patient with glaucoma),
there were no marked or statistically significant differences in outcome between
patients followed up in the hospital eye service or by community optometrists.
Decisions to implement such schemes need to be based on careful consideration of
the costs of such schemes and local circumstances, including geographical access
and the current organisation of glaucoma care within the hospital eye service.
PMID- 10781508
TI - Discriminant analysis models for early detection of glaucomatous optic disc
changes.
AB - AIM: To evaluate and compare four different mathematical formulas for the early
detection of morphometric optic nerve head changes in chronic open angle
glaucoma. METHODS: The optic nerve heads of 161 patients with perimetrically
defined glaucomatous optic nerve damage and of 194 normal subjects were examined
by confocal laser scanning tomography. Using four formulas of linear discriminant
analysis and the optic cup shape measure as the single optic disc variable, the
predictive power of each of these methods was examined to differentiate between
the normal eyes and the glaucoma eyes. RESULTS: The highest predictive power had
an optic disc sector based formula, in particular in eyes with medium and large
optic discs. This optic disc sector based formula was the one with the best
agreement with the other formulas examined. It achieved a better predictability
than any single optic disc variable evaluated. CONCLUSIONS: Combining
quantitative optic disc variables by discriminant analysis functions, the
predictive power of semiautomatic quantitative optic nerve head evaluation can be
improved by providing the ophthalmologist with a diagnostic score for the
detection of glaucomatous optic nerve damage. Because of the pattern of
glaucomatous neuroretinal rim loss, an optic disc sector based discriminant
formula may have a higher diagnostic precision than other formulas in detecting
early glaucomatous damage.
PMID- 10781509
TI - Asymmetries of the retinal nerve fibre layer thickness in normal eyes.
AB - AIMS: To investigate the variation in the retinal nerve fibre layer thickness in
detail in normal eyes with a scanning laser polarimeter. METHODS: The retinal
nerve fibre layer thickness (RNFLT) was measured in 94 normal volunteers with a
scanning laser polarimeter. The mean RNFLT around a 10 pixel-wide ellipse located
concentrically with the disc of 1.5 disc diameters was calculated for 16 sectors
each of 22.5 degrees. The symmetry of the RNFLT distribution with respect to the
horizontal midline for individual eyes and to the vertical meridian for the two
eyes was examined. RESULTS: The RNFLT was thicker on the inferior side than on
the superior side for the temporal four pairs of 22.5 degrees sectors, and the
differences were significant in two of the four temporal pairs (p<0.007). The
RNFLT was thicker in the superior than in the inferior side for the nasal four
pairs of the sectors, and the differences were significant in three of the four
nasal pairs (p<0.04). The mean RNFLT was significantly thicker in the right eyes
than in the left eyes in the four temporal sectors (p<0.02), and significantly
thicker in the left eyes than in the right eyes in the inferior two nasal sectors
(p<0.01). CONCLUSIONS: Asymmetries of the RNFLT in normal eyes with respect to
the horizontal midline and to the vertical meridian for the two eyes were found.
These asymmetries should be considered when retinal nerve fibre layer loss is
evaluated during the course of a disease process.
PMID- 10781510
TI - Relation of optic disc topography and age to thickness of retinal nerve fibre
layer as measured using scanning laser polarimetry, in normal subjects.
AB - AIMS: To evaluate the relation of the optic nerve head topographic measurements
and age with the thickness of the retinal nerve fibre layer (RNFL) in normal
Caucasoid subjects by means of scanning laser polarimetry and tomography.
METHODS: Topographic optic disc measurements and RNFL thickness values of 38
normal Caucasoid subjects of both sexes aged 20 to 78 were measured using a
confocal scanning laser ophthalmoscope and a confocal scanning laser polarimeter.
One eye was randomly selected for statistical analysis. The effects of optic disc
size, age, and optic disc head topographic measurements of total and regional
RNFL thickness were evaluated. RESULTS: Age showed a significant correlation with
the integral of the total RNFL thickness (R=-0.341, p<0.05). The optic disc size
showed a significant correlation with the integral of the total, superior, and
inferior quadrant RNFL thickness (R=0.425, p<0.01), (R=0.361, p<0.05), (R=0.468,
p<0.05). Neuroretinal rim area (NRA) had a correlation with the superior and
inferior quadrant RNFL thickness values (R=0.339, p<0.05) (R=0.393, p<0.05).
There was no significant correlation between the other optic disc topographic
measurements and RNFL thickness values (p>0.05). CONCLUSION: The thickness of
total as well as superior and inferior quadrant peripapillary RNFL as measured by
scanning laser polarimetry increased significantly with an increase in optic disc
size. The cross sectional area occupied by superior and inferior polar RNFL
increased significantly with an increase in NRA. The total cross sectional area
occupied by RNFL decreased significantly with an increase in age. The effects of
optic disc size, age, and NRA should be considered when the peripapillary RNFL
thickness is evaluated.
PMID- 10781511
TI - Polypoidal choroidal vasculopathy in exudative and haemorrhagic pigment
epithelial detachments.
AB - AIMS: To determine the prevalence of polypoidal choroidopathy in consecutive
patients presenting with large haemorrhagic and exudative neurosensory retinal
and retinal pigment epithelial detachments (PEDs) of over 2 mm in diameter in the
absence of drusen. METHODS: 40 patients were identified over a 5 month period of
which 29 had haemorrhagic detachments, and 11 had purely exudative detachments.
All had indocyanine green (ICG) angiography, and the presence was sought of large
blood vessels in the choroid associated with localised dilated terminals that
filled slowly and leaked ICG. RESULTS: In 34 cases (85%) there was an appearance
consistent with previous descriptions of idiopathic polypoidal choroidal
vasculopathy. Of the six without polypoidal lesions the disorder was attributed
to choroidal neovascularisation in four, chorioretinitis in one, and a
fibrovascular PED in one. Of those with polypoidal lesions 20 (65%) were female,
the mean age was 65.4 years (range 44-88), and 25 (74%) were white, seven (20%)
black, and two (6%) east Asian. Eight had a history of hypertension. Visual
acuity varied from 6/6 to counting fingers in the involved eye (mean 6/24).
Bilateral polypoidal choroidal lesions were demonstrated in 16 patients (47%).
The predominant location for these lesions was the macular region in 23 patients
(68%). Polypoidal vasculopathy was found in 16 patients (47%) who had a previous
diagnosis of age related macular disease (AMD). No patients had evidence of
intraocular inflammation. CONCLUSIONS: In a largely white patient population a
high proportion of patients with haemorrhagic and exudative PEDs has evidence of
polypoidal lesions on ICG angiography.
PMID- 10781512
TI - Bullous variant of idiopathic central serous chorioretinopathy.
AB - BACKGROUND: Spontaneous bullous serous retinal detachment (RD) with subretinal
exudation complicating idiopathic central serous chorioretinopathy (ICSC) is a
rare and infrequently described clinical entity. Clinical observations are
described on this variant form in 11 patients, the largest series reported to
date. METHODS: 13 eyes of 11 Indian patients having this entity were followed up
clinically and angiographically for 12-24 months (retrospective, longitudinal).
None of the patients had any previous history of other diseases nor were they on
any medications. Four eyes received laser treatment (group A); nine eyes were not
treated (group B). RESULTS: All 11 patients were male, aged 23-49 years (median
37 years). The clinical and photographic records revealed subretinal exudation
and inferior bullous serous RD complicating ICSC with evidence of large, single
or multiple, leaking retinal pigment epithelial detachments (PEDs) in all the
cases. In group A, resolution of serous RD occurred in 12 weeks (median) with a
visual recovery of >/=20/30 in three out of four eyes while in group B resolution
of serous retinal detachment was observed in 14 weeks (median) with eight out of
nine eyes achieving a visual acuity of >/=20/30. Subretinal fibrosis developed in
two eyes in group A and none of the eyes in group B. CONCLUSION: The disease is
an exaggerated form of ICSC and can occur spontaneously without any history of
corticosteroid therapy. Recognition of this atypical presentation is important to
avoid inappropriate treatment. These observations suggest that with respect to
the duration of the disease and the final visual outcome laser therapy offers no
additional benefit over the natural course of this variant form of ICSC.
PMID- 10781514
TI - A controlled study of vigabatrin and visual abnormalities.
AB - AIMS: To assess the visual function in epileptic patients who have received
vigabatrin; to compare this with the visual function in similar epileptic
patients who have never received vigabatrin; to investigate whether the severity
of visual field defect (VFD) is related to the dose of vigabatrin; to consider
other factors that may correlate with the severity of VFD. METHODS: 21
consecutive patients who had taken vigabatrin at some time in their lives were
enrolled from the epilepsy clinic of the Royal Shrewsbury Hospital and were
compared with a group of 11 otherwise similar patients with epilepsy who had
never received vigabatrin. One patient taking vigabatrin was excluded from the
study because her visual field results were unreliable because of multi-infarct
dementia. 15 patients were taking vigabatrin at the time of the study (VC), the
other five had taken vigabatrin some time in the past (VP). Each patient
underwent static perimetry using either the two point or the three point full
field 120 screening program on the Humphrey visual field analyser, followed by an
ophthalmic examination to rule out ocular causes for VFDs. The visual fields from
each patient were then analysed using a method devised to convert the VFD into
percentage defect in both eyes. In patients with known cerebral pathology that
may affect the visual pathway, only the unaffected homonymous hemifield was used.
RESULTS: Nine of 20 (45%) patients in the vigabatrin group (VC and VP) complained
of blurring of vision compared with two of 11 (18%) controls. Four patients (20%)
in the vigabatrin group described flickering lights compared with one control
(9%). None had a posterior vitreous detachment. Three of 30 (7.5%) eyes in the VC
group had distant visual acuity of 6/12 or worse compared with three of 22 (9%)
controls and five of 30 (16.7%) had near visual acuity worse than N6 compared
with one of 22 (4.5%) in the control group. A mean of 1.73 Ishihara plates were
misread in VC patients compared with 0.2 in the VP group and 0.18 in the
controls. 11 of 15 (73.3%) patients in the VC group had greater than 10% VFDs as
opposed to one of 11 (9.1%) controls (chi(2) test, p=0. 002). In 12 of 15 (80%)
VC patients the percentage VFD was greater in the nasal hemifields than the
temporal hemifields compared with six of 11 (54.5%) controls. Significant
correlation was found between the severity of VFD and the total dose of
vigabatrin ingested for the 20 patients exposed to vigabatrin (VC and VP:
Spearman correlation coefficient=0.525; p=0.002), for the 15 patients taking
vigabatrin at the time of examination (VC: Spearman correlation
coefficient=0.568; p=0.002). CONCLUSION: This pilot study suggested that
epileptic patients taking vigabatrin are at much higher risk of developing VFDs
compared with epileptic patients on other antiepileptic drugs. The total ingested
dose of vigabatrin correlated significantly with the severity of VFDs especially
in those patients who had not stopped taking vigabatrin. In our group we found
that those who had taken a total dose of 1500 g or more of vigabatrin were at
risk of developing significant visual field defects.
PMID- 10781513
TI - Ocular haemodynamics and colour contrast sensitivity in patients with type 1
diabetes.
AB - BACKGROUND: There is evidence that altered ocular blood flow is involved in the
development and progression of diabetic retinopathy. However, the nature of these
perfusion abnormalities is still a matter of controversy. Ocular haemodynamics
were characterised with two recently introduced methods. METHODS: The cross
sectional study was performed in 59 patients with type 1 diabetes with a diabetes
duration between 12 and 17 years and an age less than 32 years and a group of 25
age matched healthy controls. Scanning laser Doppler flowmetry and laser
interferometric measurement of fundus pulsation amplitude were used to assess
retinal and pulsatile choroidal blood flow, respectively. In addition, colour
contrast sensitivity along the tritan axis was determined. RESULTS: Fundus
pulsation amplitude, but not retinal blood flow, increased with the progression
of diabetic retinopathy. Retinal blood flow was influenced by plasma glucose
levels (r = 0.32), whereas fundus pulsation amplitude was associated with HbA(1c)
(r = 0.30). In addition, a negative correlation between the colour contrast
sensitivity along the tritan axis and retinal blood flow was observed.
CONCLUSIONS: The present study indicates that pulsatile choroidal blood flow
increases with the progression of diabetic retinopathy. Increased retinal blood
flow appears to be related to loss of colour sensitivity in patents with type 1
diabetes.
PMID- 10781515
TI - Risk factors for proliferative vitreoretinopathy after primary vitrectomy: a
prospective study.
AB - AIM: To assess clinical variables and vitreous protein as risk factors for the
development of postoperative proliferative vitreoretinopathy (PVR). METHODS: A
prospective study was conducted on 140 patients with a rhegmatogenous retinal
detachment in whom a primary vitrectomy was performed. 12 clinical variables were
recorded and vitreous samples obtained for measurement of protein concentration.
Univariate and multivariate logistic regression analysis was used to determine
the risk factors for PVR. RESULTS: Complete data were available for 136 of 140
patients. 40 of the 136 patients (29.4%) developed postoperative PVR. Univariate
regression revealed that significant (p<0.05) risk factors included aphakia,
presence of preoperative PVR, size of detachment, the use of silicone oil, and
high vitreous protein level. Multivariate regression analysis revealed only
aphakia (odds ratio 2.72), the presence of preoperative PVR (odds ratio 3.01),
and high vitreous protein concentration (odds ratio 1.11) to be significant
(p<0.05) independent, predictive risk factors for the development of PVR.
CONCLUSIONS: This study has shown that the significant risk factors for PVR are
preoperative PVR, aphakia, and high vitreous protein levels. Two models (clinical
factors only and clinical factors and vitreous protein) were constructed to
predict the probability of developing postoperative PVR and may be used to
identify those at risk for possible intravitreal pharmacological treatment.
PMID- 10781516
TI - 3 year simvastatin treatment and lens nuclear back scattering.
AB - AIM: To determine if 3 year treatment of hypercholesterolaemia with simvastatin
causes an increase of lens nuclear back scattering. METHODS: 160 patients with
hypercholesterolaemia in the Scandinavian Simvastatin Survival Study (4S) were
followed for 3 years. Half (80) of the patients took simvastatin and half (80)
received placebo. The lens was photographed with a Topcon SL-45 slit lamp camera
at the beginning and at 1 year intervals. A common lens nuclear area was used for
measuring lens nuclear back scattering. RESULTS: Nuclear back scattering
increased with age and there was more pronounced scattering in women than in men.
Lens nuclear back scattering did not differ significantly between the simvastatin
and placebo groups, but the power was low (0.2). Lens nuclear back scattering
increased during the study period independently of baseline back scattering, age,
and sex for both groups. CONCLUSION: Although no significant difference was found
between the simvastatin and placebo groups, the currently available data are
insufficient for exclusion of the possibility that taking simvastatin during a 3
year period increases nuclear back scattering. However, a possible minor increase
of nuclear back scattering is clinically irrelevant considering known beneficial
effects of simvastatin on coronary heart disease.
PMID- 10781517
TI - T cells and fibroblasts in affected extraocular muscles in early and late thyroid
associated ophthalmopathy.
AB - AIM: To determine whether there are differences in the lymphocytic cell
infiltrate present in affected extraocular muscles (EOM) during early and late
stages of thyroid associated ophthalmopathy (TAO). METHODS: 17 biopsies of
affected EOMs were collected from two groups of TAO patients (n=14): the first of
five patients with early, active TAO, and the second of nine patients with late,
inactive TAO. The control group was of EOM biopsies taken from 14 non-TAO
patients undergoing squint surgery. Immunohistochemical analysis was undertaken
using the relevant monoclonal antibodies and an avidin-biotin system and the
three groups compared. RESULTS: Both CD4+ and CD8+ T cells were found in the
cellular infiltrate in early, active TAO specimens which were much less evident
either in late, inactive stage disease or in control tissue. There was also a
significant increase in both CD45RO+ and CD45RB+ cells and macrophages in early
TAO compared with the others. Increased expression of HLA-DR antigen by
interstitial cells including fibroblasts was detected in both early and late
disease but the EOM fibres remained morphologically intact and did not express
MHC class II antigens at any time. CONCLUSION: These results demonstrate that T
cells are only significantly present in early disease but increased HLA-DR
antigen expression on fibroblasts is observed at all stages. This suggests that T
cells are much more involved in the early than the later stages of the disease
process and that early activation of fibroblasts occurs. Early intervention with
immunosuppressive therapy to downregulate cytokine production by T cells may
significantly influence the sequelae caused by EOM fibrosis.
PMID- 10781518
TI - Investigation of beta defensin gene expression in the ocular anterior segment by
semiquantitative RT-PCR.
AB - AIM: To determine if beta defensins are expressed in the anterior segment of the
eye and to determine the temporal pattern of expression using a real time
semiquantitative reverse transcription polymerase chain reaction (RT-PCR).
METHODS: Ocular tissue (corneal epithelium, conjunctiva, iris, and lens capsule)
was collected from 23 patients undergoing surgery. Serial corneal or conjunctival
impression cytology was performed on a separate group of 10 patients undergoing
corneal tunnel phacoemulsification or trabeculectomy. The samples were analysed
for beta defensin mRNA by semiquantitative RT-PCR and the mRNA standardised for
cell numbers. RESULTS: RT-PCR amplified beta defensin 1 mRNA from all lens
capsule (six) and corneal (five) samples and all but one of the conjunctival
(six) and iris samples (six). beta Defensin 2 mRNA was amplified from three of
five corneal, two of six conjunctival, and none of the iris or capsule samples.
The impression cytology samples demonstrated a decline in defensin expression
over the three time points studied. There were no false positive results from
either the no-RT or negative control samples. CONCLUSIONS: This preliminary study
confirms that natural antibacterial peptides are expressed in the anterior
segment of the eye. There appears to be a pattern to the expression with
inducible beta defensin 2 not expressed intraocularly and higher levels of beta
defensin 1 than beta defensin 2 expressed in extraocular tissue. The implication
is that beta defensin 1 is constitutively produced in ocular tissues and
represents a key component of the innate immune system.
PMID- 10781519
TI - A novel keratin 12 mutation in a German kindred with Meesmann's corneal
dystrophy.
AB - AIM: To study a kindred with Meesmann's corneal dystrophy (MCD) to determine if a
mutation within the cornea specific K3 or K12 genes is responsible for the
disease phenotype. METHODS: Slit lamp examination of the cornea in four members
of the kindred was carried out to confirm the diagnosis of MCD. The region
encoding the helix initiation motif (HIM) of the K12 polypeptide was polymerase
chain reaction (PCR) amplified from genomic DNA derived from affected individuals
in the kindred. PCR products generated were subjected to direct automated
sequencing. Restriction enzyme analysis employing Ban I was used to confirm the
presence of the mutation in affected individuals of the family. RESULTS:
Sequencing of the K12 gene in an affected individual from the family revealed a
novel heterozygous missense mutation (413A-->C), predicting the substitution of a
proline for a glutamine at codon 130 (Q130P) in the HIM of the K12 protein. The
mutation was excluded from 50 normal, unaffected individuals by restriction
enyzme analysis and was therefore unlikely to be a common polymorphism.
CONCLUSION: A novel missense mutation in the K12 gene leads to MCD in a German
kindred. Missense mutations have now been identified within the region encoding
the helix initiation motif of the K12 protein in eight of 11 MCD kindreds
analysed at the molecular level.
PMID- 10781520
TI - Lupus anticoagulant positivity in insulin dependent diabetic patients: an
additional risk factor in the pathogenesis of diabetic retinopathy?
AB - AIMS: To investigate whether lupus anticoagulant (LA) positivity, a marker of
endothelial dysfunction, might be relevant to the pathogenesis of diabetic
retinopathy (DR). METHODS: 32 IDDM patients were examined for LA, fibrinogen,
prothrombin (PT), PTT, prothrombin degradation products (F1+2), and activated
protein C (APC). RESULTS: APC decreased and F1+2 increased significantly in LA
positive but not in LA negative patients; 60% of LA positive and 18% of LA
negative subjects had DR. PT, PTT, and fibrinogen levels were insignificant.
CONCLUSION: These preliminary findings suggest that LA positivity could represent
an additional risk factor for DR, acting as a link between the immunological and
haemostatic systems.
PMID- 10781521
TI - Variable pattern of visual recovery of Leber's hereditary optic neuropathy.
AB - AIMS: To investigate pattern of visual recovery of nine patients with Leber's
hereditary optic neuropathy (LHON) and a mitochondrial DNA mutation at 11778.
METHODS: Recovery was judged significant when a gain of two lines or more in the
Landolt ring chart, 10 dB or more improvement of the mean deviation of static
perimetry, or improvement of critical flicker frequency (CFF) over 35 Hz was
shown. RESULTS: All three visual functions tested dramatically recovered in one
patient. Two other patients exhibited isolated improvement of CFF or visual
field, respectively. CONCLUSION: Partial improvement of visual function may be
more widespread than previously recognised in LHON patients with the 11778
mutation.
PMID- 10781522
TI - Early surgery for infantile esotropia.
AB - AIM: To investigate the postoperative eye alignment and binocular visual function
after early surgery for infantile esotropia. METHODS: Both the postoperative eye
position and stereopsis were reviewed using the Titmus stereo test in nine
patients who received uniocular medial rectus recession and lateral rectus
resection under general anaesthesia before 8 months of age and were followed up
for a minimum of 4 years. RESULTS: Orthophoria was attained in three cases,
whereas esotropia was found in four patients. Dissociated vertical deviation was
noted in two other cases at the final examination. Static stereoacuity was
achieved in five cases. These results also showed that most infants in whom
stereopsis was attained had satisfactory eye alignment during the follow up
period and at the final examination. Infants who did not achieve stereopsis still
had deviation throughout the follow up period. CONCLUSIONS: It was concluded that
early surgery in infantile esotropia is beneficial to achieve binocular visual
function, but it is necessary to confirm a stable angle of deviation with
accurate preoperative evaluation, and to maintain good postoperative eye
alignment throughout the follow up period.
PMID- 10781523
TI - Efficacy of a contact lens cleaning device and its enhancement of the performance
of contact lens care products.
AB - BACKGROUND: Corneal infections due to contact lens contamination are risks
associated with contact lens wear. Care systems which reduce these risks are
desirable. METHODS: This study evaluated a contact lens cleaning device using
normal saline initially and then four contact lens solutions. RESULTS: Using
saline, six out of 10 tests resulted in complete removal of challenge organisms
or showed reductions to 10 cfu/ml or <10 cfu/ml. Tests upon organism using
multipurpose solutions showed >6 log reductions in 2-3 minutes. With laboratory
made biofilms, similar results were obtained. CONCLUSIONS: This device improves
lens cleaning and enhances lens care solutions. When used correctly it should
lead to significant reductions in microbial keratitis associated with inadequate
contact lens hygiene.
PMID- 10781525
TI - Intraocular lens implants and risk of endophthalmitis.
PMID- 10781526
TI - Pupillary abnormality.
PMID- 10781527
TI - "Cyclodiode".
PMID- 10781524
TI - Macular oedema: the role of soluble mediators.
PMID- 10781528
TI - Is non-arteritic anterior ischaemic optic neuropathy related to homocysteine?
PMID- 10781530
TI - Clinical ophthalmology
PMID- 10781529
TI - Laser pointers: not to be taken lightly.
PMID- 10781531
TI - The rise and fall of modern medicine
PMID- 10781532
TI - Biofilm, city of microbes.
PMID- 10781533
TI - Assessment of flhDC mRNA levels in Serratia liquefaciens swarm cells.
AB - We reported previously that artificial overexpression of the flhDC operon in
liquid-grown Serratia liquefaciens resulted in the formation of filamentous,
multinucleated, and hyperflagellated cells that were indistinguishable from
surface-induced swarm cells (L. Eberl, G. Christiansen, S. Molin, and M. Givskov,
J. Bacteriol. 178:554-559, 1996). In the present report we show by means of
reporter gene measurements, Northern analysis, and in situ reverse transcription
PCR that the amount of flhDC mRNA in surface-grown swarm cells does not exceed
the maximum level found in nondifferentiated, vegetative cells. This suggests
that surface-induced S. liquefaciens swarm cell differentiation, although
dependent on flhDC gene expression, does not occur through elevated flhDC mRNA
levels.
PMID- 10781534
TI - Deletion analysis of the Escherichia coli taurine and alkanesulfonate transport
systems.
AB - The Escherichia coli tauABCD and ssuEADCB gene clusters are required for the
utilization of taurine and alkanesulfonates as sulfur sources and are expressed
only under conditions of sulfate or cysteine starvation. tauD and ssuD encode an
alpha-ketoglutarate-dependent taurine dioxygenase and a reduced flavin
mononucleotide-dependent alkanesulfonate monooxygenase, respectively. These
enzymes are responsible for the desulfonation of taurine and alkanesulfonates.
The amino acid sequences of SsuABC and TauABC exhibit similarity to those of
components of the ATP-binding cassette transporter superfamily, suggesting that
two uptake systems for alkanesulfonates are present in E. coli. Chromosomally
located in-frame deletions of the tauABC and ssuABC genes were constructed in E.
coli strain EC1250, and the growth properties of the mutants were studied to
investigate the requirement for the TauABC and SsuABC proteins for growth on
alkanesulfonates as sulfur sources. Complementation analysis of in-frame deletion
mutants confirmed that the growth phenotypes obtained were the result of the in
frame deletions constructed. The range of substrates transported by these two
uptake systems was largely reflected in the substrate specificities of the TauD
and SsuD desulfonation systems. However, certain known substrates of TauD were
transported exclusively by the SsuABC system. Mutants in which only formation of
hybrid transporters was possible were unable to grow with sulfonates, indicating
that the individual components of the two transport systems were not functionally
exchangeable. The TauABCD and SsuEADCB systems involved in alkanesulfonate uptake
and desulfonation thus are complementary to each other at the levels of both
transport and desulfonation.
PMID- 10781535
TI - A mutation in the Corynebacterium glutamicum ltsA gene causes susceptibility to
lysozyme, temperature-sensitive growth, and L-glutamate production.
AB - The Corynebacterium glutamicum mutant KY9714, originally isolated as a lysozyme
sensitive mutant, does not grow at 37 degrees C. Complementation tests and DNA
sequencing analysis revealed that a mutation in a single gene of 1,920 bp, ltsA
(lysozyme and temperature sensitive), was responsible for its lysozyme
sensitivity and temperature sensitivity. The ltsA gene encodes a protein
homologous to the glutamine-dependent asparagine synthetases of various
organisms, but it could not rescue the asparagine auxotrophy of an Escherichia
coli asnA asnB double mutant. Replacement of the N-terminal Cys residue (which is
conserved in glutamine-dependent amidotransferases and is essential for enzyme
activity) by an Ala residue resulted in the loss of complementation in C.
glutamicum. The mutant ltsA gene has an amber mutation, and the disruption of the
ltsA gene caused lysozyme and temperature sensitivity similar to that in the
KY9714 mutant. L-Glutamate production was induced by elevating growth temperature
in the disruptant. These results indicate that the ltsA gene encodes a novel
glutamine-dependent amidotransferase that is involved in the mechanisms of
formation of rigid cell wall structure and in the L-glutamate production of C.
glutamicum.
PMID- 10781537
TI - Conjugative junctions in RP4-mediated mating of Escherichia coli.
AB - The physical association of bacteria during conjugation mediated by the IncPalpha
plasmid RP4 was investigated. Escherichia coli mating aggregates prepared on
semisolid medium were ultrarapidly frozen using copper block freezing, followed
by freeze substitution, thin sectioning, and transmission electron microscopy. In
matings where the donor bacteria contained conjugative plasmids, distinctive
junctions were observed between the outer membranes of the aggregates of mating
cells. An electron-dense layer linked the stiffly parallel outer membranes in the
junction zone, but there were no cytoplasmic bridges nor apparent breaks in the
cell walls or membranes. In control experiments where the donors lacked
conjugative plasmids, junctions were not observed. Previous studies have shown
that plasmid RP4 carries operons for both plasmid DNA processing (Tra1) and
mating pair formation (Tra2). In matings where donor strains carried Tra2 only or
Tra2 plus the pilin-processing protease TraF, junctions were found but they were
shorter and more interrupted than the wild type. If the donor strain had the
pilin gene knocked out (trbC), junctions were still found. Thus, it appears that
the electron-dense layer between the outer membranes of the conjugating cells is
not composed of pilin.
PMID- 10781536
TI - The Pseudomonas quinolone signal regulates rhl quorum sensing in Pseudomonas
aeruginosa.
AB - The opportunistic pathogen Pseudomonas aeruginosa uses intercellular signals to
control the density-dependent expression of many virulence factors. The las and
rhl quorum-sensing systems function, respectively, through the autoinducers N-(3
oxododecanoyl)-L-homoserine lactone and N-butyryl-L-homoserine lactone (C(4)
HSL), which are known to positively regulate the transcription of the elastase
encoding gene, lasB. Recently, we reported that a second type of intercellular
signal is involved in lasB induction. This signal was identified as 2-heptyl-3
hydroxy-4-quinolone and designated the Pseudomonas quinolone signal (PQS). PQS
was determined to be part of the quorum-sensing hierarchy since its production
and bioactivity depended on the las and rhl quorum-sensing systems, respectively.
In order to define the role of PQS in the P. aeruginosa quorum-sensing cascade,
lacZ gene fusions were used to determine the effect of PQS on the transcription
of the quorum-sensing system genes lasR, lasI, rhlR, and rhlI. We found that in
P. aeruginosa, PQS caused a major induction of rhlI'-lacZ and had lesser effects
on the transcription of lasR'-lacZ and rhlR'-lacZ. We also observed that the
transcription of both rhlI'-lacZ and lasB'-lacZ was cooperatively effected by
C(4)-HSL and PQS. Additionally, we present data indicating that PQS was not
produced maximally until cultures reached the late stationary phase of growth.
Taken together, our results imply that PQS acts as a link between the las and rhl
quorum-sensing systems and that this signal is not involved in sensing cell
density.
PMID- 10781539
TI - Haloalkane-utilizing Rhodococcus strains isolated from geographically distinct
locations possess a highly conserved gene cluster encoding haloalkane catabolism.
AB - The sequences of the 16S rRNA and haloalkane dehalogenase (dhaA) genes of five
gram-positive haloalkane-utilizing bacteria isolated from contaminated sites in
Europe, Japan, and the United States and of the archetypal haloalkane-degrading
bacterium Rhodococcus sp. strain NCIMB13064 were compared. The 16S rRNA gene
sequences showed less than 1% sequence divergence, and all haloalkane degraders
clearly belonged to the genus Rhodococcus. All strains shared a completely
conserved dhaA gene, suggesting that the dhaA genes were recently derived from a
common ancestor. The genetic organization of the dhaA gene region in each of the
haloalkane degraders was examined by hybridization analysis and DNA sequencing.
Three different groups could be defined on the basis of the extent of the
conserved dhaA segment. The minimal structure present in all strains consisted of
a conserved region of 12.5 kb, which included the haloalkane-degradative gene
cluster that was previously found in strain NCIMB13064. Plasmids of different
sizes were found in all strains. Southern hybridization analysis with a dhaA gene
probe suggested that all haloalkane degraders carry the dhaA gene region both on
the chromosome and on a plasmid (70 to 100 kb). This suggests that an ancestral
plasmid was transferred between these Rhodococcus strains and subsequently has
undergone insertions or deletions. In addition, transposition events and/or
plasmid integration may be responsible for positioning the dhaA gene region on
the chromosome. The data suggest that the haloalkane dehalogenase gene regions of
these gram-positive haloalkane-utilizing bacteria are composed of a single
catabolic gene cluster that was recently distributed worldwide.
PMID- 10781538
TI - The H(2) sensor of Ralstonia eutropha is a member of the subclass of regulatory
[NiFe] hydrogenases.
AB - Two energy-generating hydrogenases enable the aerobic hydrogen bacterium
Ralstonia eutropha (formerly Alcaligenes eutrophus) to use molecular hydrogen as
the sole energy source. The complex synthesis of the nickel-iron-containing
enzymes has to be efficiently regulated in response to H(2), which is available
in low amounts in aerobic environments. H(2) sensing in R. eutropha is achieved
by a hydrogenase-like protein which controls the hydrogenase gene expression in
concert with a two-component regulatory system. In this study we show that the
H(2) sensor of R. eutropha is a cytoplasmic protein. Although capable of H(2)
oxidation with redox dyes as electron acceptors, the protein did not support
lithoautotrophic growth in the absence of the energy-generating hydrogenases. A
specifically designed overexpression system for R. eutropha provided the basis
for identifying the H(2) sensor as a nickel-containing regulatory protein. The
data support previous results which showed that the sensor has an active site
similar to that of prototypic [NiFe] hydrogenases (A. J. Pierik, M. Schmelz, O.
Lenz, B. Friedrich, and S. P. J. Albracht, FEBS Lett. 438:231-235, 1998). It is
demonstrated that in addition to the enzymatic activity the regulatory function
of the H(2) sensor is nickel dependent. The results suggest that H(2) sensing
requires an active [NiFe] hydrogenase, leaving the question open whether only
H(2) binding or subsequent H(2) oxidation and electron transfer processes are
necessary for signaling. The regulatory role of the H(2)-sensing hydrogenase of
R. eutropha, which has also been investigated in other hydrogen-oxidizing
bacteria, is intimately correlated with a set of typical structural features.
Thus, the family of H(2) sensors represents a novel subclass of [NiFe]
hydrogenases denoted as the "regulatory hydrogenases."
PMID- 10781540
TI - Identification of genes encoding exported Mycobacterium tuberculosis proteins
using a Tn552'phoA in vitro transposition system.
AB - Secreted and cell envelope-associated proteins are important to both
Mycobacterium tuberculosis pathogenesis and the generation of protective immunity
to M. tuberculosis. We used an in vitro Tn552'phoA transposition system to
identify exported proteins of M. tuberculosis. The system is simple and
efficient, and the transposon inserts randomly into target DNA. M. tuberculosis
genomic libraries were targeted with Tn552'phoA transposons, and these libraries
were screened in M. smegmatis for active PhoA translational fusions. Thirty-two
different M. tuberculosis open reading frames were identified; eight contain
standard signal peptides, six contain lipoprotein signal peptides, and seventeen
contain one or more transmembrane domains. Four of these proteins had not yet
been assigned as exported proteins in the M. tuberculosis databases. This
collection of exported proteins includes factors that are known to participate in
the immune response of M. tuberculosis and proteins with homologies, suggesting a
role in pathogenesis. Nine of the proteins appear to be unique to mycobacteria
and represent promising candidates for factors that participate in protective
immunity and virulence. This technology of creating comprehensive fusion
libraries should be applicable to other organisms.
PMID- 10781542
TI - The promoter of the yeast INO4 regulatory gene: a model of the simplest yeast
promoter.
AB - In Saccharomyces cerevisiae, the phospholipid biosynthetic genes are
transcriptionally regulated in response to inositol and choline. This regulation
requires the transcriptional activator proteins Ino4p and Ino2p, which form a
heterodimer that binds to the UAS(INO) element. We have previously shown that the
promoters of the INO4 and INO2 genes are among the weakest promoters
characterized in yeast. Because little is known about the promoters of weakly
expressed yeast genes, we report here the analysis of the constitutive INO4
promoter. Promoter deletion constructs scanning 1,000 bp upstream of the INO4
gene identified a small region (-58 to -46) that is absolutely required for
expression. S1 nuclease mapping shows that this region contains the transcription
start sites for the INO4 gene. An additional element (-114 to -86) modestly
enhances INO4 promoter activity (fivefold). Thus, the region required for INO4
transcription is limited to 68 bp. These studies also found that INO4 gene
expression is not autoregulated by Ino2p and Ino4p, despite the presence of a
putative UAS(INO) element in the INO4 promoter. We further report that the INO4
steady-state transcript levels and Ino4p levels are regulated twofold in response
to inositol and choline, suggesting a posttranscriptional mechanism of
regulation.
PMID- 10781541
TI - Regulation of the Escherichia coli K5 capsule gene cluster: evidence for the
roles of H-NS, BipA, and integration host factor in regulation of group 2 capsule
gene clusters in pathogenic E. coli.
AB - The expression of Escherichia coli group 2 capsules (K antigens) is temperature
dependent, with capsules only being expressed at temperatures above 20 degrees C.
Thermoregulation is at the level of transcription, with no detectable
transcription at 20 degrees C. Using the E. coli K5 capsule gene cluster as a
model system, we have shown that the nucleoid-associated protein H-NS plays a
dual role in regulating transcription of group 2 capsule gene clusters at 37 and
20 degrees C. At 37 degrees C H-NS is required for maximal transcription of group
2 capsule gene clusters, whereas at 20 degrees C H-NS functions to repress
transcription. The BipA protein, previously identified as a tyrosine
phosphorylated GTPase and essential for virulence in enteropathogenic E. coli,
was shown to play a similar role to H-NS in regulating transcription at 37 and 20
degrees C. The binding of integration host factor (IHF) to the region 1 promoter
was necessary to potentiate transcription at 37 degrees C and IHF binding
demonstrated by bandshift assays. The IHF binding site was 3' to the site of
transcription initiation, suggesting that sequences in the 5' end of the first
gene (kpsF) in region 1 may play a role in regulating transcription from this
promoter at 37 degrees C. Two additional cis-acting sequences, conserved in both
the region 1 and 3 promoters, were identified, suggesting a role for these
sequences in the coordinate regulation of transcription from these promoters.
These results indicate that a complex regulatory network involving a number of
global regulators exists for the control of expression of group 2 capsules in E.
coli.
PMID- 10781543
TI - 2-Hydroxycyclohexanecarboxyl coenzyme A dehydrogenase, an enzyme characteristic
of the anaerobic benzoate degradation pathway used by Rhodopseudomonas palustris.
AB - A gene, badH, whose predicted product is a member of the short-chain
dehydrogenase/reductase family of enzymes, was recently discovered during studies
of anaerobic benzoate degradation by the photoheterotrophic bacterium
Rhodopseudomonas palustris. Purified histidine-tagged BadH protein catalyzed the
oxidation of 2-hydroxycyclohexanecarboxyl coenzyme A (2-hydroxychc-CoA) to 2
ketocyclohexanecarboxyl-CoA. These compounds are proposed intermediates of a
series of three reactions that are shared by the pathways of
cyclohexanecarboxylate and benzoate degradation used by R. palustris. The 2
hydroxychc-CoA dehydrogenase activity encoded by badH was dependent on the
presence of NAD(+); no activity was detected with NADP(+) as a cofactor. The
dehydrogenase activity was not sensitive to oxygen. The enzyme has apparent K(m)
values of 10 and 200 microM for 2-hydroxychc-CoA and NAD(+), respectively.
Western blot analysis with antisera raised against purified His-BadH identified a
27-kDa protein that was present in benzoate- and cyclohexanecarboxylate-grown but
not in succinate-grown R. palustris cell extracts. The active form of the enzyme
is a homotetramer. badH was determined to be the first gene in an operon, termed
the cyclohexanecarboxylate degradation operon, containing genes required for both
benzoate and cyclohexanecarboxylate degradation. A nonpolar R. palustris badH
mutant was unable to grow on benzoate or cyclohexanecarboxylate but had wild-type
growth rates on succinate. Cells blocked in expression of the entire
cyclohexanecarboxylate degradation operon excreted cyclohex-1-ene-1-carboxylate
into the growth medium when given benzoate. This confirms that cyclohex-1-ene-1
carboxyl-CoA is an intermediate of anaerobic benzoate degradation by R.
palustris. This compound had previously been shown not to be formed by Thauera
aromatica, a denitrifying bacterium that degrades benzoate by a pathway that is
slightly different from the R. palustris pathway. 2-Hydroxychc-CoA dehydrogenase
does not participate in anaerobic benzoate degradation by T. aromatica and thus
may serve as a useful indicator of an R. palustris-type benzoate degradation
pathway.
PMID- 10781544
TI - Enzymology of type IV macromolecule secretion systems: the conjugative transfer
regions of plasmids RP4 and R388 and the cag pathogenicity island of Helicobacter
pylori encode structurally and functionally related nucleoside triphosphate
hydrolases.
AB - Type IV secretion systems direct transport of protein or nucleoprotein complexes
across the cell envelopes of prokaryotic donor and eukaryotic or prokaryotic
recipient cells. The process is mediated by a membrane-spanning multiprotein
assembly. Potential NTPases belonging to the VirB11 family are an essential part
of the membrane-spanning complex. Three representatives of these NTPases
originating from the conjugative transfer regions of plasmids RP4 (TrbB) and R388
(TrwD) and from the cag pathogenicity island of Helicobacter pylori (HP0525) were
overproduced and purified in native form. The proteins display NTPase activity
with distinct substrate specificities in vitro. TrbB shows its highest specific
hydrolase activity with dATP, and the preferred substrate for HP0525 is ATP.
Analysis of defined TrbB mutations altered in motifs conserved within the VirB11
protein family shows that there is a correlation between the loss or reduction of
NTPase activity and transfer frequency. Tryptophan fluorescence spectroscopy of
TrbB and HP0525 suggests that both interact with phospholipid membranes, changing
their conformation. NTPase activity of both proteins was stimulated by the
addition of certain phospholipids. According to our results, Virb11-like proteins
seem to most likely be involved in the assembly of the membrane-spanning
multiprotein complex.
PMID- 10781545
TI - The Bacillus subtilis GTP binding protein obg and regulators of the sigma(B)
stress response transcription factor cofractionate with ribosomes.
AB - Obg, an essential GTP binding protein of Bacillus subtilis, is necessary for
stress activation of the sigma(B) transcription factor. We investigated Obg's
cellular associations by differential centrifugation of crude B. subtilis
extracts, using an anti-Obg antibody as a probe to monitor Obg during the
fractionation, and by fluorescent microscopy of a B. subtilis strain in which Obg
was fused to green fluorescent protein. The results indicated that Obg is part of
a large cytoplasmic complex. In subsequent analyses, Obg coeluted with ribosomal
subunits during gel filtration of B. subtilis lysates on Sephacryl S-400 and
specifically bound to ribosomal protein L13 in an affinity blot assay. Probing
the gel filtration fractions with antibodies specific for sigma(B) and its
coexpressed regulators (Rsb proteins) revealed coincident elution of the upstream
components of the sigma(B) stress activation pathway (RsbR, -S, and -T) with Obg
and the ribosomal subunits. The data implicate ribosome function as a possible
mediator of the activity of Obg and the stress induction of sigma(B).
PMID- 10781546
TI - Transcriptional control of expression of genes for photosynthetic reaction center
and light-harvesting proteins in the purple bacterium Rhodovulum sulfidophilum.
AB - The purple photosynthetic bacterium Rhodovulum sulfidophilum synthesizes
photosynthetic apparatus even under highly aerated conditions in the dark. To
understand the oxygen-independent expression of photosynthetic genes, the
expression of the puf operon coding for the light-harvesting 1 and reaction
center proteins was analyzed. Northern blot hybridization analysis showed that
puf mRNA synthesis was not significantly repressed by oxygen in this bacterium.
High-resolution 5' mapping of the puf mRNA transcriptional initiation sites and
DNA sequence analysis of the puf upstream regulatory region indicated that there
are three possible promoters for the puf operon expression, two of which have a
high degree of sequence similarity with those of Rhodobacter capsulatus, which
shows a high level of oxygen repression of photosystem synthesis. Deletion
analysis showed that the third promoter is oxygen independent, but the activity
of this promoter was not enough to explain the aerobic level of mRNA. The
posttranscriptional puf mRNA degradation is not significantly influenced by
oxygen in R. sulfidophilum. From these results, we conclude that puf operon
expression in R. sulfidophilum is weakly repressed by oxygen, perhaps as a result
of the following: (i) there are three promoters for puf operon transcription, at
least one of which is oxygen independent; (ii) readthrough transcripts which may
not be affected by oxygen may be significant in maintaining the puf mRNA levels;
and (iii) the puf mRNA is fairly stable even under aerobic conditions.
PMID- 10781547
TI - Purification and characterization of the R64 shufflon-specific recombinase.
AB - The shufflon, a multiple DNA inversion system in plasmid R64, consists of four
invertible DNA segments which are separated and flanked by seven 19-bp repeat
sequences. The product of a site-specific recombinase gene, rci, promotes site
specific recombination between any two of the inverted 19-bp repeat sequences of
the shufflon. To analyze the molecular mechanism of this recombination reaction,
Rci protein was overproduced and purified. The purified Rci protein promoted the
in vitro recombination reaction between the inverted 19-bp repeats of supercoiled
DNA of a plasmid carrying segment A of the R64 shufflon. The recombination
reaction was enhanced by the bacterial host factor HU. Gel electrophoretic
analysis indicated that the Rci protein specifically binds to the DNA segments
carrying the 19-bp sequences. The binding affinity of the Rci protein to the four
shufflon segments as well as four synthetic 19-bp sequences differed greatly:
among the four 19-bp repeat sequences, the repeat-a and -d sequences displayed
higher affinity to Rci protein. These results suggest that the differences in the
affinity of Rci protein for the 19-bp repeat sequences determine the inversion
frequencies of the four segments.
PMID- 10781548
TI - Real-time imaging of fluorescent flagellar filaments.
AB - Bacteria swim by rotating flagellar filaments that are several micrometers long,
but only about 20 nm in diameter. The filaments can exist in different
polymorphic forms, having distinct values of curvature and twist. Rotation rates
are on the order of 100 Hz. In the past, the motion of individual filaments has
been visualized by dark-field or differential-interference-contrast microscopy,
methods hampered by intense scattering from the cell body or shallow depth of
field, respectively. We have found a simple procedure for fluorescently labeling
cells and filaments that allows recording their motion in real time with an
inexpensive video camera and an ordinary fluorescence microscope with mercury-arc
or strobed laser illumination. We report our initial findings with cells of
Escherichia coli. Tumbles (events that enable swimming cells to alter course) are
remarkably varied. Not every filament on a cell needs to change its direction of
rotation: different filaments can change directions at different times, and a
tumble can result from the change in direction of only one. Polymorphic
transformations tend to occur in the sequence normal, semicoiled, curly 1, with
changes in the direction of movement of the cell body correlated with
transformations to the semicoiled form.
PMID- 10781549
TI - Characterization of an extracellular lipase encoded by LIP2 in Yarrowia
lipolytica.
AB - We isolated the LIP2 gene from the lipolytic yeast Yarrowia lipolytica. It was
found to encode a 334-amino-acid precursor protein. The secreted lipase is a 301
amino-acid glycosylated polypeptide which is a member of the triacylglycerol
hydrolase family (EC 3.1.1.3). The Lip2p precursor protein is processed by the
KEX2-like endoprotease encoded by XPR6. Deletion of the XPR6 gene resulted in the
secretion of an active but less stable proenzyme. Thus, the pro region does not
inhibit lipase secretion and activity. However, it does play an essential role in
the production of a stable enzyme. Processing was found to be correct in LIP2(A)
(multiple LIP2 copy integrant)-overexpressing strains, which secreted 100 times
more activity than the wild type, demonstrating that XPR6 maturation was not
limiting. No extracellular lipase activity was detected with the lip2 knockout
(KO) strain, strongly suggesting that extracellular lipase activity results from
expression of the LIP2 gene. Nevertheless, the lip2 KO strain is still able to
grow on triglycerides, suggesting an alternative pathway for triglyceride
utilization in Y. lipolytica.
PMID- 10781551
TI - In vivo analysis of the mechanisms for oxidation of cytosolic NADH by
Saccharomyces cerevisiae mitochondria.
AB - During respiratory glucose dissimilation, eukaryotes produce cytosolic NADH via
glycolysis. This NADH has to be reoxidized outside the mitochondria, because the
mitochondrial inner membrane is impermeable to NADH. In Saccharomyces cerevisiae,
this may involve external NADH dehydrogenases (Nde1p or Nde2p) and/or a glycerol
3-phosphate shuttle consisting of soluble (Gpd1p or Gpd2p) and membrane-bound
(Gut2p) glycerol-3-phosphate dehydrogenases. This study addresses the
physiological relevance of these mechanisms and the possible involvement of
alternative routes for mitochondrial oxidation of cytosolic NADH. Aerobic,
glucose-limited chemostat cultures of a gut2Delta mutant exhibited fully
respiratory growth at low specific growth rates. Alcoholic fermentation set in at
the same specific growth rate as in wild-type cultures (0.3 h(-1)). Apparently,
the glycerol-3-phosphate shuttle is not essential for respiratory glucose
dissimilation. An nde1Delta nde2Delta mutant already produced glycerol at
specific growth rates of 0.10 h(-1) and above, indicating a requirement for
external NADH dehydrogenase to sustain fully respiratory growth. An nde1Delta
nde2Delta gut2Delta mutant produced even larger amounts of glycerol at specific
growth rates ranging from 0.05 to 0.15 h(-1). Apparently, even at a low
glycolytic flux, alternative mechanisms could not fully replace the external NADH
dehydrogenases and glycerol-3-phosphate shuttle. However, at low dilution rates,
the nde1Delta nde2Delta gut2Delta mutant did not produce ethanol. Since glycerol
production could not account for all glycolytic NADH, another NADH-oxidizing
system has to be present. Two alternative mechanisms for reoxidizing cytosolic
NADH are discussed: (i) cytosolic production of ethanol followed by its
intramitochondrial oxidation and (ii) a redox shuttle linking cytosolic NADH
oxidation to the internal NADH dehydrogenase.
PMID- 10781550
TI - LuxR- and acyl-homoserine-lactone-controlled non-lux genes define a quorum
sensing regulon in Vibrio fischeri.
AB - The luminescence (lux) operon (luxICDABEG) of the symbiotic bacterium Vibrio
fischeri is regulated by the transcriptional activator LuxR and two acyl
homoserine lactone (acyl-HSL) autoinducers (the luxI-dependent 3-oxo-hexanoyl-HSL
[3-oxo-C6-HSL] and the ainS-dependent octanoyl-HSL [C8-HSL]) in a population
density-responsive manner called quorum sensing. To identify quorum-sensing
regulated (QSR) proteins different from those encoded by lux genes, we examined
the protein patterns of V. fischeri quorum-sensing mutants defective in luxI,
ainS, and luxR by two-dimensional polyacrylamide gel electrophoresis. Five non
Lux QSR proteins, QsrP, RibB, AcfA, QsrV, and QSR 7, were identified; their
production occurred preferentially at high population density, required both LuxR
and 3-oxo-C6-HSL, and was inhibited by C8-HSL at low population density. The
genes encoding two of the QSR proteins were characterized: qsrP directs cells to
synthesize an apparently novel periplasmic protein, and ribB is a homolog of the
Escherichia coli gene for 3,4-dihydroxy-2-butanone 4-phosphate synthase, a key
enzyme for riboflavin synthesis. The qsrP and ribB promoter regions each
contained a sequence similar to the lux operon lux box, a 20-bp region of dyad
symmetry necessary for LuxR/3-oxo-C6-HSL-dependent activation of lux operon
transcription. V. fischeri qsrP and ribB mutants exhibited no distinct phenotype
in culture. However, a qsrP mutant, in competition with its parent strain, was
less successful in colonizing Euprymna scolopes, the symbiotic host of V.
fischeri. The newly identified QSR genes, together with the lux operon, define a
LuxR/acyl-HSL-responsive quorum-sensing regulon in V. fischeri.
PMID- 10781553
TI - Catabolism of alpha-ketoglutarate by a sucA mutant of Bradyrhizobium japonicum:
evidence for an alternative tricarboxylic acid cycle.
AB - A complete tricarboxylic acid (TCA) cycle is generally considered necessary for
energy production from the dicarboxylic acid substrates malate, succinate, and
fumarate. However, a Bradyrhizobium japonicum sucA mutant that is missing alpha
ketoglutarate dehydrogenase is able to grow on malate as its sole source of
carbon. This mutant also fixes nitrogen in symbiosis with soybean, where
dicarboxylic acids are its principal carbon substrate. Using a flow chamber
system to make direct measurements of oxygen consumption and ammonium excretion,
we confirmed that bacteroids formed by the sucA mutant displayed wild-type rates
of respiration and nitrogen fixation. Despite the absence of alpha-ketoglutarate
dehydrogenase activity, whole cells of the mutant were able to decarboxylate
alpha-[U-(14)C]ketoglutarate and [U-(14)C]glutamate at rates similar to those of
wild-type B. japonicum, indicating that there was an alternative route for alpha
ketoglutarate catabolism. Because cell extracts from B. japonicum decarboxylated
[U-(14)C]glutamate very slowly, the gamma-aminobutyrate shunt is unlikely to be
the pathway responsible for alpha-ketoglutarate catabolism in the mutant. In
contrast, cell extracts from both the wild type and mutant showed a coenzyme A
(CoA)-independent alpha-ketoglutarate decarboxylation activity. This activity was
independent of pyridine nucleotides and was stimulated by thiamine PP(i). Thin
layer chromatography showed that the product of alpha-ketoglutarate
decarboxylation was succinic semialdehyde. The CoA-independent alpha
ketoglutarate decarboxylase, along with succinate semialdehyde dehydrogenase, may
form an alternative pathway for alpha-ketoglutarate catabolism, and this pathway
may enhance TCA cycle function during symbiotic nitrogen fixation.
PMID- 10781552
TI - Expression of uptake hydrogenase and molybdenum nitrogenase in Rhodobacter
capsulatus is coregulated by the RegB-RegA two-component regulatory system.
AB - Purple photosynthetic bacteria are capable of generating cellular energy from
several sources, including photosynthesis, respiration, and H(2) oxidation. Under
nutrient-limiting conditions, cellular energy can be used to assimilate carbon
and nitrogen. This study provides the first evidence of a molecular link for the
coregulation of nitrogenase and hydrogenase biosynthesis in an anoxygenic
photosynthetic bacterium. We demonstrated that molybdenum nitrogenase
biosynthesis is under the control of the RegB-RegA two-component regulatory
system in Rhodobacter capsulatus. Footprint analyses and in vivo transcription
studies showed that RegA indirectly activates nitrogenase synthesis by binding to
and activating the expression of nifA2, which encodes one of the two functional
copies of the nif-specific transcriptional activator, NifA. Expression of nifA2
but not nifA1 is reduced in the reg mutants up to eightfold under derepressing
conditions and is also reduced under repressing conditions. Thus, although NtrC
is absolutely required for nifA2 expression, RegA acts as a coactivator of nifA2.
We also demonstrated that in reg mutants, [NiFe]hydrogenase synthesis and
activity are increased up to sixfold. RegA binds to the promoter of the
hydrogenase gene operon and therefore directly represses its expression. Thus,
the RegB-RegA system controls such diverse processes as energy-generating
photosynthesis and H(2) oxidation, as well as the energy-demanding processes of
N(2) fixation and CO(2) assimilation.
PMID- 10781554
TI - Efficient spore synthesis in Bacillus subtilis depends on the CcdA protein.
AB - CcdA is known to be required for the synthesis of c-type cytochromes in Bacillus
subtilis, but the exact function of this membrane protein is not known. We show
that CcdA also plays a role in spore synthesis. The expression of ccdA and the
two downstream genes yneI and yneJ was analyzed. There is a promoter for each
gene, but there is only one transcription terminator, located after the yneJ
gene. The promoter for ccdA was found to be weak and was active mainly during the
transition from exponential growth to stationary phase. The promoters for yneI
and yneJ were both active in the exponential growth phase. The levels of the CcdA
and YneJ proteins in the membrane were consistent with the observed promoter
activities. The ccdA promoter activity was independent of whether the ccdA-yneI
yneJ gene products were absent or overproduced in the cell. It is shown that the
four known cytochromes c in B. subtilis and the YneI and YneJ proteins are not
required for sporulation. The combined data from analysis of sporulation-specific
sigma factor activity, resistance properties of spores, and spore morphology
indicate that CcdA deficiency affects stage V in sporulation. We conclude that
CcdA, YneI, and YneJ are functionally unrelated proteins and that the role of
CcdA in cytochrome c and spore synthesis probably relates to sulfhydryl redox
chemistry on the outer surface of the cytoplasmic membrane.
PMID- 10781556
TI - Cloning and characterization of the CSF1 gene of Saccharomyces cerevisiae, which
is required for nutrient uptake at low temperature.
AB - We have isolated cold-sensitive fermentation mutants (Csf mutants) of a
commercial baker's yeast that have practically no fermentation capacity at 5
degrees C and return to their normal capacity at 25 to 40 degrees C. CSF1 was
cloned by functional complementation of the Csf phenotype. CSF1 contain an open
reading frame of 8,874 nucleotides, encoding a protein of 2,958 amino acids. The
nucleotide sequence was identical to that of the YLR087C gene in the
Saccharomyces genome database, but there was no information about the function of
the predicted CSF1 (YLR087C) protein. Gene disruption shows that CSF1 is required
for growth and fermentation only at low temperatures. Permeabilized cells of the
disruptant showed nearly the same ethanol production rate as those of the parent
strain, even at 10 degrees C. The disruptant cells had the same glucose uptake
rates as the parental cells at 30 degrees C, but three- to fivefold-lower rates
than the parental cells at 10 degrees C. These findings suggest that CSF1
associates with a new nutrient transport system which exists on the plasma
membrane and is required only at low temperature.
PMID- 10781555
TI - Biosynthesis of lipoteichoic acid in Lactobacillus rhamnosus: role of DltD in D
alanylation.
AB - The dlt operon (dltA to dltD) of Lactobacillus rhamnosus 7469 encodes four
proteins responsible for the esterification of lipoteichoic acid (LTA) by D
alanine. These esters play an important role in controlling the net anionic
charge of the poly (GroP) moiety of LTA. dltA and dltC encode the D-alanine-D
alanyl carrier protein ligase (Dcl) and D-alanyl carrier protein (Dcp),
respectively. Whereas the functions of DltA and DltC are defined, the functions
of DltB and DltD are unknown. To define the role of DltD, the gene was cloned and
sequenced and a mutant was constructed by insertional mutagenesis of dltD from
Lactobacillus casei 102S. Permeabilized cells of a dltD::erm mutant lacked the
ability to incorporate D-alanine into LTA. This defect was complemented by the
expression of DltD from pNZ123/dlt. In in vitro assays, DltD bound Dcp for
ligation with D-alanine by Dcl in the presence of ATP. In contrast, the homologue
of Dcp, the Escherichia coli acyl carrier protein (ACP), involved in fatty acid
biosynthesis, was not bound to DltD and thus was not ligated with D-alanine. DltD
also catalyzed the hydrolysis of the mischarged D-alanyl-ACP. The hydrophobic N
terminal sequence of DltD was required for anchoring the protein in the membrane.
It is hypothesized that this membrane-associated DltD facilitates the binding of
Dcp and Dcl for ligation of Dcp with D-alanine and that the resulting D-alanyl
Dcp is translocated to the primary site of D-alanylation.
PMID- 10781557
TI - The ssu locus plays a key role in organosulfur metabolism in Pseudomonas putida S
313.
AB - Pseudomonas putida S-313 can utilize a broad range of aromatic sulfonates as
sulfur sources for growth in sulfate-free minimal medium. The sulfonates are
cleaved monooxygenolytically to yield the corresponding phenols. miniTn5 mutants
of strain S-313 which were no longer able to desulfurize arylsulfonates were
isolated and were found to carry transposon insertions in the ssuEADCBF operon,
which contained genes for an ATP-binding cassette-type transporter (ssuABC), a
two-component reduced flavin mononucleotide-dependent monooxygenase (ssuED)
closely related to the Escherichia coli alkanesulfonatase, and a protein related
to clostridial molybdopterin-binding proteins (ssuF). These mutants were also
deficient in growth with a variety of other organosulfur sources, including
aromatic and aliphatic sulfate esters, methionine, and aliphatic sulfonates other
than the natural sulfonates taurine and cysteate. This pleiotropic phenotype was
complemented by the ssu operon, confirming its key role in organosulfur
metabolism in this species. Further complementation analysis revealed that the
ssuF gene product was required for growth with all of the tested substrates
except methionine and that the oxygenase encoded by ssuD was required for growth
with sulfonates or methionine. The flavin reductase SsuE was not required for
growth with aliphatic sulfonates or methionine but was needed for growth with
arylsulfonates, suggesting that an alternative isozyme exists for the former
compounds that is not active in transformation of the latter substrates. Aryl
sulfate ester utilization was catalyzed by an arylsulfotransferase, and not by an
arylsulfatase as in the related species Pseudomonas aeruginosa.
PMID- 10781558
TI - Contribution of cysteine desulfurase (NifS protein) to the biotin synthase
reaction of Escherichia coli.
AB - The contribution of cysteine desulfurase, the NifS protein of Klebsiella
pneumoniae and the IscS protein of Escherichia coli, to the biotin synthase
reaction was investigated in in vitro and in vivo reaction systems with E. coli.
When the nifS and nifU genes of K. pneumoniae were coexpressed in E. coli, NifS
and NifU proteins in complex (NifU/S complex) and NifU monomer forms were
observed. Both the NifU/S complex and the NifU monomer stimulated the biotin
synthase reaction in the presence of L-cysteine in an in vitro reaction system.
The NifU/S complex enhanced the production of biotin from dethiobiotin by the
cells growing in an in vivo reaction system. Moreover, the IscS protein of E.
coli stimulated the biotin synthase reaction in the presence of L-cysteine in the
cell-free system. These results strongly suggest that cysteine desulfurase
participates in the biotin synthase reaction, probably by supplying sulfur to the
iron-sulfur cluster of biotin synthase.
PMID- 10781560
TI - Growth phase-coupled changes of the ribosome profile in natural isolates and
laboratory strains of Escherichia coli.
AB - The growth phase-dependent change in sucrose density gradient centrifugation
patterns of ribosomes was analyzed for both laboratory strains of Escherichia
coli and natural isolates from the ECOR collection. All of the natural isolates
examined formed 100S ribosome dimers in the stationary phase, and ribosome
modulation factor (RMF) was associated with the ribosome dimers in the ECOR
strains as in the laboratory strain W3110. The ribosome profile (70S monomers
versus 100S dimers) follows a defined pattern over time during lengthy culture in
both the laboratory strains and natural isolates. There are four discrete stages:
(i) formation of 100S dimers in the early stationary phase; (ii) transient
decrease in the dimer level; (iii) return of dimers to the maximum level; and
(iv) dissociation of 100S dimers into 70S ribosomes, which are quickly degraded
into subassemblies. The total time for this cycle of ribosome profile change,
however, varied from strain to strain, resulting in apparent differences in the
ribosome profiles when observed at a fixed time point. A correlation was noted in
all strains between the decay of 100S ribosomes and the subsequent loss of cell
viability. Two types of E. coli mutants defective in ribosome dimerization were
identified, both of which were unable to survive for a prolonged period in
stationary phase. The W3110 mutant, with a disrupted rmf gene, has a defect in
ribosome dimerization because of lack of RMF, while strain Q13 is unable to form
ribosome dimers due to a ribosomal defect in binding RMF.
PMID- 10781559
TI - Initiation of protein synthesis in Saccharomyces cerevisiae mitochondria without
formylation of the initiator tRNA.
AB - Protein synthesis in eukaryotic organelles such as mitochondria and chloroplasts
is widely believed to require a formylated initiator methionyl tRNA (fMet
tRNA(fMet)) for initiation. Here we show that initiation of protein synthesis in
yeast mitochondria can occur without formylation of the initiator methionyl-tRNA
(Met-tRNA(fMet)). The formylation reaction is catalyzed by methionyl-tRNA
formyltransferase (MTF) located in mitochondria and uses N(10)
formyltetrahydrofolate (10-formyl-THF) as the formyl donor. We have studied yeast
mutants carrying chromosomal disruptions of the genes encoding the mitochondrial
C(1)-tetrahydrofolate (C(1)-THF) synthase (MIS1), necessary for synthesis of 10
formyl-THF, and the methionyl-tRNA formyltransferase (open reading frame YBL013W;
designated FMT1). A direct analysis of mitochondrial tRNAs using gel
electrophoresis systems that can separate fMet-tRNA(fMet), Met-tRNA(fMet), and
tRNA(fMet) shows that there is no formylation in vivo of the mitochondrial
initiator Met-tRNA in these strains. In contrast, the initiator Met-tRNA is
formylated in the respective "wild-type" parental strains. In spite of the
absence of fMet-tRNA(fMet), the mutant strains exhibited normal mitochondrial
protein synthesis and function, as evidenced by normal growth on nonfermentable
carbon sources in rich media and normal frequencies of generation of petite
colonies. The only growth phenotype observed was a longer lag time during growth
on nonfermentable carbon sources in minimal media for the mis1 deletion strain
but not for the fmt1 deletion strain.
PMID- 10781561
TI - Gene rearrangements in the vsa locus of Mycoplasma pulmonis.
AB - The vsa genes of Mycoplasma pulmonis encode the V-1 lipoproteins. Most V-1
proteins contain repetitive domains and are thought to be involved in mycoplasma
host cell interactions. Previously, we have reported the isolation and
characterization of six vsa genes comprising a 10-kb region of the genome of M.
pulmonis strain KD735-15. In the current study, vsa-specific probes were used to
clone several fragments from a genomic library of KD735-15 DNA and assemble a
single 20-kb contig containing 11 vsa genes. The middle region of the vsa locus
contains a large open reading frame (ORF) that is not a vsa gene and has
undergone an internal deletion in some strains. The ORF is predicted to encode a
membrane protein that may have a role in disease pathogenesis. To examine vsa
genes in a strain of M. pulmonis that is unrelated to KD735-15, strain CT was
studied. Through Southern hybridization and genomic cloning analyses, CT was
found to possess homologs of the KD735-15 vsaA, -C, -E, and -F genes and two
unique genes (vsaG and vsaH) that were not found in KD735-15. High-frequency,
site-specific DNA inversions serve to regulate the phase-variable production of
individual V-1 proteins. As a result of the sequence analysis of vsa
recombination products, a model in which DNA inversion arises from strand
exchange involving at least six nucleotides of the vrs box is proposed.
PMID- 10781562
TI - Altered stationary-phase response in a Borrelia burgdorferi rpoS mutant.
AB - The homolog of the chromosomally encoded stationary-phase sigma factor RpoS in
Borrelia burgdorferi was inactivated using gyrB(r) as a selectable marker. Two
dimensional nonequilibrium pH gradient electrophoresis of stationary-phase cell
lysates identified at least 11 differences between the protein profiles of the
rpoS mutant and wild-type organisms. Wild-type B. burgdorferi had a growth phase
dependent resistance to 1 N NaCl, similar to the stationary-phase response
reported for other bacteria. The B. burgdorferi rpoS mutant strain was less
resistant to osmotic stress in stationary phase than the isogenic rpoS wild-type
organism. The results indicate that the B. burgdorferi rpoS homolog influences
protein composition and participates in stationary-phase-dependent osmotic
resistance. This rpoS mutant will be useful for studying regulation of gene
expression in response to changing environmental conditions.
PMID- 10781563
TI - A dispensable role for forespore-specific gene expression in engulfment of the
forespore during sporulation of Bacillus subtilis.
AB - During the stage of engulfment in the Bacillus subtilis spore formation pathway,
the larger mother cell engulfs the smaller forespore. We have tested the role of
forespore-specific gene expression in engulfment using two separate approaches.
First, using an assay that unambiguously detects sporangia that have completed
engulfment, we found that a mutant lacking the only forespore-expressed
engulfment protein identified thus far, SpoIIQ, is able to efficiently complete
engulfment under certain sporulation conditions. However, we have found that the
mutant is defective, under all conditions, in the expression of the late
forespore-specific transcription factor sigma(G); thus, SpoIIQ is essential for
spore production. Second, to determine if engulfment could proceed in the absence
of forespore-specific gene expression, we made use of a strain in which
activation of the mother cell-specific sigma factor sigma(E) was uncoupled from
forespore-specific gene expression. Remarkably, engulfment occurred in the
complete absence of sigma(F)-directed gene expression under the same conditions
permissive for engulfment in the absence of SpoIIQ. Our results demonstrate that
forespore-specific gene expression is not essential for engulfment, suggesting
that the machinery used to move the membranes around the forespore is within the
mother cell.
PMID- 10781564
TI - Multiple-locus variable-number tandem repeat analysis reveals genetic
relationships within Bacillus anthracis.
AB - Bacillus anthracis is one of the most genetically homogeneous pathogens
described, making strain discrimination particularly difficult. In this paper, we
present a novel molecular typing system based on rapidly evolving variable-number
tandem repeat (VNTR) loci. Multiple-locus VNTR analysis (MLVA) uses the combined
power of multiple alleles at several marker loci. In our system, fluorescently
labeled PCR primers are used to produce PCR amplification products from eight
VNTR regions in the B. anthracis genome. These are detected and their sizes are
determined using an ABI377 automated DNA sequencer. Five of these eight loci were
discovered by sequence characterization of molecular markers (vrrC(1), vrrC(2),
vrrB(1), vrrB(2), and CG3), two were discovered by searching complete plasmid
nucleotide sequences (pXO1-aat and pXO2-at), and one was known previously (vrrA).
MLVA characterization of 426 B. anthracis isolates identified 89 distinct
genotypes. VNTR markers frequently identified multiple alleles (from two to
nine), with Nei's diversity values between 0.3 and 0.8. Unweighted pair-group
method arithmetic average cluster analysis identified six genetically distinct
groups that appear to be derived from clones. Some of these clones show worldwide
distribution, while others are restricted to particular geographic regions. Human
commerce doubtlessly has contributed to the dispersal of particular clones in
ancient and modern times.
PMID- 10781566
TI - Pressure regulation of soluble cytochromes c in a deep-Sea piezophilic bacterium,
Shewanella violacea.
AB - Two c-type cytochromes from the soluble fraction of a deep-sea moderately
piezophilic bacterium, Shewanella violacea, were purified and characterized, and
the genes coding for these cytochromes were cloned and sequenced. One of the
cytochromes, designated cytochrome c(A), was found to have a molecular mass of
approximately 8.3 kDa, and it contained one heme c per molecule. The other,
designated cytochrome c(B), was found to have a molecular mass of approximately
23 kDa, and it contained two heme c molecules per protein molecule. The amount of
cytochrome c(B) expressed in cells grown at high hydrostatic pressure (50 MPa)
was less than that in cells grown at atmospheric pressure, whereas cytochrome
c(A) was constitutively expressed under all pressure conditions examined. The
results of Northern blotting analysis were consistent with the above-mentioned
observations and suggested that the pressure regulation of cytochrome c(B) gene
expression occurred at the transcriptional level. These results suggest that the
components of the respiratory chain of moderately piezophilic S. violacea could
be exchanged according to the growth pressure conditions.
PMID- 10781565
TI - NhaA, an Na(+)/H(+) antiporter involved in environmental survival of Vibrio
cholerae.
AB - Vibrio cholerae, the agent of cholera, is a normal inhabitant of aquatic
environments, in which it survives under a wide range of conditions of pH and
salinity. In this work, we identified the nhaA gene in a wild-type epidemic
strain of V. cholerae O1. nhaA encodes a protein of 382 amino acids that is very
similar to the proteins NhaA of Vibrio parahaemolyticus, Vibrio alginolyticus (
approximately 87% identity), and Escherichia coli (56% identity). V. cholerae
NhaA complements an E. coli nhaA mutant, enabling it to grow in 700 mM NaCl, pH
7.5, indicating functional homology to E. coli NhaA. However, unlike E. coli, the
growth of a nhaA-inactivated mutant of V. cholerae was not restricted at various
pH and NaCl concentrations, although it was inhibited in the presence of 120 mM
LiCl at pH 8.5. Nevertheless, using a nhaA'-lacZ transcriptional fusion, we
observed induction of nhaA transcription by Na(+), Li(+), and K(+). These results
strongly suggest that NhaA is an Na(+)/H(+) antiporter contributing to the
Na(+)/H(+) homeostasis of V. cholerae. nhaA-related sequences were detected in
all strains of V. cholerae from the various serogroups. This gene is presumably
involved in the survival and persistence of free-living bacteria in their natural
habitat.
PMID- 10781567
TI - Interaction of the FimB integrase with the fimS invertible DNA element in
Escherichia coli in vivo and in vitro.
AB - The FimB protein is a site-specific recombinase that inverts the fimS genetic
switch in Escherichia coli. Based on amino acid sequence analysis alone, FimB has
been assigned to the integrase family of tyrosine recombinases. We show that
amino acid substitutions at positions R47, H141, R144, and Y176, corresponding to
highly conserved members of the catalytic motif of integrase proteins, render
FimB incapable of inverting the fimS element in vivo. The arginine substitutions
reduced the ability of FimB to bind to fimS in vivo or in vitro, while the
substitution R144Q resulted in a protein unable to bind independently to the half
sites located at the left end of fimS in phase-on bacteria. These data confirm
that FimB is an integrase and suggest that residue R144 has a role in binding to
a specific component of the fim switch.
PMID- 10781569
TI - Prephenate dehydratase from the aphid endosymbiont (Buchnera) displays changes in
the regulatory domain that suggest its desensitization to inhibition by
phenylalanine.
AB - Buchnera aphidicola, the prokaryotic endosymbiont of aphids, complements dietary
deficiencies with the synthesis and provision of several essential amino acids.
We have cloned and sequenced a region of the genome of B. aphidicola isolated
from Acyrthosiphon pisum which includes the two-domain aroQ/pheA gene. This gene
encodes the bifunctional chorismate mutase-prephenate dehydratase protein, which
plays a central role in L-phenylalanine biosynthesis. Two changes involved in the
overproduction of this amino acid have been detected. First, the absence of an
attenuator region suggests a constitutive expression of this gene. Second, the
regulatory domain of the Buchnera prephenate dehydratase shows changes in the
ESRP sequence, which is involved in the allosteric binding of phenylalanine and
is strongly conserved in prephenate dehydratase proteins from practically all
known organisms. These changes suggest the desensitization of the enzyme to
inhibition by phenylalanine and would permit the bacterial endosymbiont to
overproduce phenylalanine.
PMID- 10781568
TI - The ArcB sensor kinase of Escherichia coli: genetic exploration of the
transmembrane region.
AB - The Arc two-component signal transduction system of Escherichia coli regulates
the expression of numerous operons in response to respiratory growth conditions.
Cellular redox state or proton motive force (Delta(H(+))) has been proposed to be
the signal for the membrane-associated ArcB sensor kinase. This study provided
evidence for a short ArcB periplasmic bridge that contains a His47. The
dispensability of this amino acid, the only amino acid with a pK in the
physiological range, renders the Delta(H(+)) model unlikely. Furthermore, results
from substituting membrane segments of ArcB with counterparts of MalF indicate
that the region does not play a stereospecific role in signal reception.
PMID- 10781570
TI - Complete nucleotide sequence of Tn10.
AB - The complete nucleotide sequence of Tn10 has been determined. The dinucleotide
signature and percent G+C of the sequence had no discontinuities, indicating that
Tn10 constitutes a homogeneous unit. The new sequence contained three new open
reading frames corresponding to a glutamate permease, repressors of heavy metal
resistance operons, and a hypothetical protein in Bacillus subtilis. The
glutamate permease was fully functional when expressed, but Tn10 did not protect
Escherichia coli from the toxic effects of various metals.
PMID- 10781571
TI - A study of the CopF repressor of plasmid pAMbeta1 by phage display.
AB - We studied DNA binding of a transcriptional repressor, CopF, displayed on a
filamentous phage. Mutagenesis of a putative helix-turn-helix motif of CopF and
of certain bases of the operator abolished the protein-DNA interaction,
establishing the elements involved in CopF function and showing that phage
display can be used to study repressor proteins.
PMID- 10781572
TI - FabG, an NADPH-dependent 3-ketoacyl reductase of Pseudomonas aeruginosa, provides
precursors for medium-chain-length poly-3-hydroxyalkanoate biosynthesis in
Escherichia coli.
AB - Escherichia coli hosts expressing fabG of Pseudomonas aeruginosa showed 3
ketoacyl coenzyme A (CoA) reductase activity toward R-3-hydroxyoctanoyl-CoA.
Furthermore, E. coli recombinants carrying the poly-3-hydroxyalkanoate (PHA)
polymerase-encoding gene phaC in addition to fabG accumulated medium-chain-length
PHAs (mcl-PHAs) from alkanoates. When E. coli fadB or fadA mutants, which are
deficient in steps downstream or upstream of the 3-ketoacyl-CoA formation step
during beta-oxidation, respectively, were transformed with fabG, higher levels of
PHA were synthesized in E. coli fadA, whereas similar levels of PHA were found in
E. coli fadB, compared with those of the corresponding mutants carrying phaC
alone. These results strongly suggest that FabG of P. aeruginosa is able to
reduce mcl-3-ketoacyl-CoAs generated by the beta-oxidation to 3-hydroxyacyl-CoAs
to provide precursors for the PHA polymerase.
PMID- 10781573
TI - Positioning of region 4 of the Escherichia coli RNA polymerase sigma(70) subunit
by a transcription activator.
AB - A DNA cleavage reagent, specifically tethered to residue 581 of the Escherichia
coli RNA polymerase sigma(70) subunit, has been used to investigate the location
of sigma(70) region 4 in different complexes at the galp(1) promoter and the
effect of the cyclic AMP receptor protein. The positions of DNA cleavage by the
reagent are not affected by the cyclic AMP receptor protein. We conclude that
transcription activation at the galp(1) promoter by the cyclic AMP receptor
protein does not involve major conformation changes in or repositioning of
sigma(70) region 4.
PMID- 10781574
TI - Sulfolobicins, specific proteinaceous toxins produced by strains of the extremely
thermophilic archaeal genus Sulfolobus.
AB - Several novel strains of "Sulfolobus islandicus" produced proteinaceous toxins,
termed sulfolobicins, which killed cells of other strains of the same species, as
well as of Sulfolobus solfataricus P1 and Sulfolobus shibatae B12, but not of the
producer strains and of Sulfolobus acidocaldarius DSM639. The sulfolobicin
purified from the strain HEN2/2 had a molecular mass of about 20 kDa. It was
found to be associated with the producer cells as well as with cell-derived S
layer-coated spherical membrane vesicles 90 to 180 nm in diameter and was not
released from the cells in soluble form.
PMID- 10781575
TI - Control of initiation of sporulation by replication initiation genes in Bacillus
subtilis.
AB - Initiation of spore formation in Bacillus subtilis appears to depend on
initiation of DNA replication. This regulation was first identified using a
temperature-sensitive mutation in dnaB. We found that mutations in the
replication initiation genes dnaA and dnaD also inhibit sporulation, indicating
that inhibition of sporulation is triggered by general defects in the function of
replication initiation proteins.
PMID- 10781576
TI - Comparison of folding rates of homologous prokaryotic and eukaryotic proteins.
AB - The rate of polypeptide chain elongation is up to one order of magnitude faster
in prokaryotic cells than in eukaryotes. Here we report that the rates of in
vitro refolding of orthologous prokaryotic and eukaryotic proteins correlate with
their differential rates of biosynthesis. The mitochondrial and cytosolic
aspartate aminotransferases of chicken and aspartate aminotransferase of
Escherichia coli show pairwise sequence identities of 41-48% and nearly identical
three-dimensional structures. Nevertheless, the prokaryotic enzyme refolded 6
times faster (at 25 degrees C) than the eukaryotic isoenzymes after denaturation
in 6 m guanidine hydrochloride. Prokaryotic malate dehydrogenase and lactate
dehydrogenase also renatured faster than their orthologous eukaryotic
counterparts, suggesting that evolutionary pressure has adapted the rate of
folding to the rate of elongation of polypeptide chains.
PMID- 10781577
TI - Kinetic analyses of a truncated mammalian myosin I suggest a novel isomerization
event preceding nucleotide binding.
AB - MI(1IQ) is a complex of calmodulin and an epitope-tagged 85-kDa fragment
representing the amino-terminal catalytic motor domain and the first of 6
calmodulin-binding IQ domains of the mammalian myosin I gene, rat myr-1 (130-kDa
myosin I or MI(130)). We have determined the transient kinetic parameters that
dictate the ATP hydrolysis cycle of mammalian myosin I by examining the
properties of MI(1IQ). Transient kinetics reveal that the affinity of MI(1IQ) for
actin is 12 nm. The ATP-induced dissociation of actin-MI(1IQ) is biphasic. The
fast phase is dependent upon [ATP], whereas the slow phase is not; both phases
show a Ca(2+) sensitivity. The fast phase is eliminated by the addition of ADP,
10 micrometer being required for half-saturation of the effect in the presence of
Ca(2+) and 3 micrometer ADP in the absence of Ca(2+). The slow phase shares the
same rate constant as ADP release (8 and 3 s(-)(1) in the presence and absence of
Ca(2+), respectively), but cannot be eliminated by decreasing [ADP]. We interpret
these results to suggest that actin-myosin I exists in two forms in equilibrium,
one of which is unable to bind nucleotide. These results also indicate that the
absence of the COOH-terminal 5 calmodulin binding domains of myr-1 do not
influence the kinetic properties of MI(130) and that the Ca(2+) sensitivity of
the kinetics are in all likelihood due to Ca(2+) binding to the first IQ domain.
PMID- 10781578
TI - Paxillin binding to a conserved sequence motif in the alpha 4 integrin
cytoplasmic domain.
AB - alpha(4)beta(1) integrin-mediated cell adhesion results in increased cell
migration, reduced cell spreading, and focal adhesion formation relative to other
beta(1) integrins. Paxillin, a signaling adapter protein, binds tightly to the
alpha(4) cytoplasmic domain and is implicated in alpha(4) integrin signaling. We
now report the mapping of a paxillin-binding site in the alpha(4) cytoplasmic
domain and an assessment of its role in the alpha(4) tail-specific integrin
functions. By using truncation mutants and a peptide competition assay, we found
that a region of 9 amino acid residues (Glu(983)-Tyr(991)) within the alpha(4)
cytoplasmic domain contains a minimal sequence sufficient for paxillin binding.
Alanine scanning of this region implicated Tyr(991) and Glu(983) as critical
residues. The role of these residues was confirmed by introducing these Ala
substitutions into the full-length alpha(4) tail sequence. Y991A or E983A
substitution disrupted the interaction of alpha(4) integrins with paxillin. These
same two point mutations reversed the effects of the alpha(4) tail on cell
spreading. The key features of the identified paxillin-binding sequence are
present in all alpha(4) integrins sequenced to date, including that from Xenopus
laevis. The maintenance of this sequence motif suggests that paxillin binding is
an evolutionarily conserved function of alpha(4) integrins.
PMID- 10781579
TI - Thrombin-mediated feedback activation of factor XI on the activated platelet
surface is preferred over contact activation by factor XIIa or factor XIa.
AB - To study the pathways for initiation of intrinsic blood coagulation, activated
human platelets were compared with dextran sulfate as surfaces for factor XI
activation by factor XIIa, factor XIa, or thrombin. Activated gel-filtered
platelets promoted the activation of factor XI (60 nm) by thrombin (0.02-10 nm,
EC(50) approximately 100 pm, threshold concentration approximately 10 pm) at
initial rates 2- to 3-fold greater than those obtained with dextran sulfate in
the presence of either high molecular weight kininogen (45 nm) and ZnCl(2) (25
micrometer) or prothrombin (1.2 micrometer) and CaCl(2) (2 mm). The maximum rates
of factor XI activation achieved in the presence of activated gel-filtered
platelets were 30 nm.min(-1) with thrombin, 6 nm.min(-1) with factor XIIa and 2
nm.min(-1) with factor XIa. Values of turnover number calculated at various
enzyme concentrations (0.05-1 nm) were 24-167 (mean = 86) min(-1) for thrombin,
4.6-50 (mean = 21) min(-1) for factor XIIa, and 1.3-14 (mean = 8) min(-1) for
factor XIa. A physiological concentration of fibrinogen (9.0 micrometer)
inhibited factor XI activation by thrombin (but not by factor XIIa) in the
presence of dextran sulfate but not in the presence of gel-filtered platelets.
Compared with factors XIIa and XIa, thrombin is the preferred factor XI
activator, and activated platelets are a relevant physiological surface for
thrombin-mediated initiation of intrinsic coagulation in vivo.
PMID- 10781580
TI - GRB2 links signaling to actin assembly by enhancing interaction of neural Wiskott
Aldrich syndrome protein (N-WASp) with actin-related protein (ARP2/3) complex.
AB - Proteins of the Wiskott-Aldrich Syndrome protein (WASp) family connect signaling
pathways to the actin polymerization-driven cell motility. The ubiquitous homolog
of WASp, N-WASp, is a multidomain protein that interacts with the Arp2/3 complex
and G-actin via its C-terminal WA domain to stimulate actin polymerization. The
activity of N-WASp is enhanced by the binding of effectors like Cdc42-guanosine
5'-3-O-(thio)triphosphate, phosphatidylinositol bisphosphate, or the Shigella
IcsA protein. Here we show that the SH3-SH2-SH3 adaptor Grb2 is another activator
of N-WASp that stimulates actin polymerization by increasing the amount of N
WASp. Arp2/3 complex. The concentration dependence of N-WASp activity,
sedimentation velocity and cross-linking experiments together suggest that N-WASp
is subject to self-association, and Grb2 enhances N-WASp activity by binding
preferentially to its active monomeric form. Use of peptide inhibitors, mutated
Grb2, and isolated SH3 domains demonstrate that the effect of Grb2 is mediated by
the interaction of its C-terminal SH3 domain with the proline-rich region of N
WASp. Cdc42 and Grb2 bind simultaneously to N-WASp and enhance actin
polymerization synergistically. Grb2 shortens the delay preceding the onset of
Escherichia coli (IcsA) actin-based reconstituted movement. These results suggest
that Grb2 may activate Arp2/3 complex-mediated actin polymerization downstream
from the receptor tyrosine kinase signaling pathway.
PMID- 10781581
TI - Identification of a sequence of apolipoprotein A-I associated with the activation
of Lecithin:Cholesterol acyltransferase.
AB - We aimed to distinguish between the effects of mutations in apoA-I on the
requirements for the secondary structure and a specific amino acid sequence for
lecithin:cholesterol acyltransferase (LCAT) activation. Several mutants were
constructed targeting region 140-150: (i) two mutations affecting alpha-helical
structure, deletion of amino acids 140-150 and substitution of Ala(143) for
proline; (ii) two mutations not affecting alpha-helical structure, substitution
of Val(149) for arginine and substitution of amino acids 63-73 for sequence 140
150; and (iii) a mutation in a similar region away from the target area, deletion
of amino acids 63-73. All mutations affecting region 140-150 resulted in a 4-42
fold reduction in LCAT activation. Three mutations, apoA-I(Delta140-150), apoA
I(P143A), and apoA-I(140-150 --> 63-73), affected both the apparent V(max) and
K(m), whereas the mutation apoA-I(R149V) affected only the V(max). The mutation
apoA-I(Delta63-73) caused only a 5-fold increase in the K(m). All mutants, except
apoA-I(P143A) and apoA-I(Delta63-73), were active in phospholipid binding assay.
All mutants, except apoA-I(P143A), formed normal discoidal complexes with
phospholipid. The mutation apoA-I(Delta63-73) caused a significant reduction in
the stability of apoA-I.phospholipid complexes in denaturation experiments.
Combined, our results strongly suggest that although the correct conformation and
orientation of apoA-I in the complex with lipids are crucial for activation of
LCAT, when these conditions are fulfilled, activation also strongly depends on
the sequence that includes amino acids 140-150.
PMID- 10781582
TI - ERKs and p38 kinase phosphorylate p53 protein at serine 15 in response to UV
radiation.
AB - Phosphorylation of the p53 tumor suppressor protein is likely to play an
important role in regulating its activity. Serine 15 phosphorylation of p53 leads
to a stabilization of p53 by reducing its interaction with murine double minute
2, a negative regulatory partner. Recently, p53 was reported to be activated and
phosphorylated at serine 15 following UV radiation. However, the signaling
pathway that mediates UV-induced phosphorylation is less well characterized.
Here, we provide evidence that UVB-induced phosphorylation of p53 at serine 15 is
mediated directly by ERKs and p38 kinase. We find that in a mouse JB6 epidermal
cell line, ERKs and p38 kinase form a complex with p53 following UVB radiation.
Inhibition of ERKs or p38 kinase activity by the use of a dominant negative
mutant of ERK2 or p38 kinase or their respective specific inhibitor, PD98059 or
SB202190, results in abrogation of UVB-induced phosphorylation of p53 at serine
15. Strikingly, incubation of UVB-activated ERKs or p38 kinase immunoprecipitated
complex with exogenous p53 shows serine 15 phosphorylation of both exogenous and
co-precipitated endogenous p53 protein. Additionally, active recombinant ERK1/2
and p38 kinase but not JNKs are also able to phosphorylate p53 at serine 15 in
vitro. Furthermore, pretreatment of cells with PD98059 or SB202190 blocks p53
dependent transcription activity but increases the level of p53 co-precipitated
murine double minute. These results strongly suggest that both ERKs and p38
kinase have a direct role in UVB-induced phosphorylation of p53 at serine 15 in
vivo.
PMID- 10781583
TI - Allosteric interactions between the two non-equivalent nucleotide binding domains
of multidrug resistance protein MRP1.
AB - Membrane transporters of the adenine nucleotide binding cassette (ABC)
superfamily utilize two either identical or homologous nucleotide binding domains
(NBDs). Although the hydrolysis of ATP by these domains is believed to drive
transport of solute, it is unknown why two rather than a single NBD is required.
In the well studied P-glycoprotein multidrug transporter, the two appear to be
functionally equivalent, and a strongly supported model proposes that ATP
hydrolysis occurs alternately at each NBD (Senior, A. E., al-Shawi, M. K., and
Urbatsch, I. L. (1995) FEBS Lett 377, 285-289). To assess how applicable this
model may be to other ABC transporters, we have examined adenine nucleotide
interactions with the multidrug resistance protein, MRP1, a member of a different
ABC family that transports conjugated organic anions and in which sequences of
the two NBDs are much less similar than in P-glycoprotein. Photoaffinity labeling
experiments with 8-azido-ATP, which strongly supports transport revealed ATP
binding exclusively at NBD1 and ADP trapping predominantly at NBD2. Despite this
apparent asymmetry in the two domains, they are entirely interdependent as
substitution of key lysine residues in the Walker A motif of either impaired both
ATP binding and ADP trapping. Furthermore, the interaction of ADP at NBD2 appears
to allosterically enhance the binding of ATP at NBD1. Glutathione, which supports
drug transport by the protein, does not enhance ATP binding but stimulates the
trapping of ADP. Thus MRP1 may employ a more complex mechanism of coupling ATP
utilization to the export of agents from cells than P-glycoprotein.
PMID- 10781584
TI - Formation of the catecholamine release-inhibitory peptide catestatin from
chromogranin A. Determination of proteolytic cleavage sites in hormone storage
granules.
AB - The catestatin fragment of chromogranin A is an inhibitor of catecholamine
release, but its occurrence in vivo has not yet been verified, nor have its
precise cleavage sites been established. Here we found extensive processing of
catestatin in chromogranin A, as judged by catestatin radioimmunoassay of size
fractionated chromaffin granules. On mass spectrometry, a major catestatin form
was bovine chromogranin A(332-364); identity of the peptide was confirmed by
diagnostic Met(346) oxidation. Further analysis revealed two additional forms:
bovine chromogranin A(333-364) and A(343-362). Synthetic longer (chromogranin
A(332-364)) and shorter (chromogranin A(344-364)) versions of catestatin each
inhibited catecholamine release from chromaffin cells, with superior potency for
the shorter version (IC(50) approximately 2.01 versus approximately 0.35 microm).
Radioimmunoassay demonstrated catestatin release from the regulated secretory
pathway in chromaffin cells. Human catestatin was cleaved in pheochromocytoma
chromaffin granules, with the major form, human chromogranin A(340-372), bounded
by dibasic sites. We conclude that catestatin is cleaved extensively in vivo, and
the peptide is released by exocytosis. In chromaffin granules, the major form of
catestatin is cleaved at dibasic sites, while smaller carboxyl-terminal forms
also occur. Knowledge of cleavage sites of catestatin from chromogranin A may
provide a useful starting point in analysis of the relationship between structure
and function for this peptide.
PMID- 10781585
TI - Differential expression of B1-containing transcripts in Leishmania-exposed
macrophages.
AB - When the parasitic protozoan Leishmania infect host macrophage cells,
establishment of the infection requires alteration in the expression of genes in
both the parasite and the host cells. In the early phase of infection of
macrophages in vitro, Leishmania exposure affects the expression of a group of
mouse macrophage genes containing the repetitive transposable element designated
B1 sequence. In Leishmania-exposed macrophages compared with unexposed
macrophages, small (approximately 0.5 kilobase) B1-containing RNAs (small B1
RNAs) are down-regulated, and large (1-4 kilobases) B1-containing RNAs (large B1
RNA) are up-regulated. The down-regulation of small B1-RNAs precedes the up
regulation of large B1-RNAs in Leishmania-exposed macrophages. These differential
B1-containing gene expressions in Leishmania-exposed macrophages were verified
using individual small-B1-RNA and large B1-RNA. The differential expressions of
the B1-containing RNAs at the early phase of Leishmania-macrophage interaction
may associate the establishment of the leishmanial infection.
PMID- 10781586
TI - Association of L-glutamic acid decarboxylase to the 70-kDa heat shock protein as
a potential anchoring mechanism to synaptic vesicles.
AB - Recently we have reported that the membrane-associated form of the gamma
aminobutyric acid-synthesizing enzyme, l-glutamate decarboxylase (MGAD), is
regulated by the vesicular proton gradient (Hsu, C. C., Thomas, C., Chen, W.,
Davis, K. M., Foos, T., Chen, J. L., Wu, E., Floor, E., Schloss, J. V., and Wu,
J. Y. (1999) J. Biol. Chem. 274, 24366-24371). In this report, several lines of
evidence are presented to indicate that l-glutamate decarboxylase (GAD) can
become membrane-associated to synaptic vesicles first through complex formation
with the heat shock protein 70 family, specifically heat shock cognate 70
(HSC70), followed by interaction with cysteine string protein (CSP), an integral
protein of the synaptic vesicle. The first line of evidence comes from
purification of MGAD in which HSC70, as identified from amino acid sequencing, co
purified with GAD. Second, in reconstitution studies, HSC70 was found to form
complex with GAD(65) as shown by gel mobility shift in non-denaturing gradient
gel electrophoresis. Third, in immunoprecipitation studies, again, HSC70 was co
immunoprecipitated with GAD by a GAD(65)-specific monoclonal antibody. Fourth,
HSC70 and CSP were co-purified with GAD by specific anti-GAD immunoaffinity
columns. Furthermore, studies here suggest that both GAD(65) and GAD(67) are
associated with synaptic vesicles along with HSC70 and CSP. Based on these
findings, a model is proposed to link anchorage of MGAD to synaptic vesicles in
relation to its role in gamma-aminobutyric acid neurotransmission.
PMID- 10781587
TI - Identification of a novel chemokine (CCL28), which binds CCR10 (GPR2).
AB - We report the identification and characterization of a novel CC chemokine
designated CCL28 and its receptor CCR10, known previously as orphan G-protein
coupled receptor GPR2. Human and mouse CCL28 share 83% identity at the amino acid
and 76% at the nucleic acid levels. We also identified the mouse homologues of
CCL28 and of CCR10, which map to mouse chromosomes 13 and 11, respectively. CCL28
is expressed in a variety of human and mouse tissues, and it appears to be
predominantly produced by epithelial cells. Both human and mouse CCL28 induce
calcium mobilization in human and mouse CCR10-expressing transfectants. CCL28
desensitized the calcium mobilization induced in CCR10 transfectants by CCL27,
indicating that these chemokines share this new chemokine receptor. In vitro,
recombinant human CCL28 displays chemotactic activity for resting CD4 or CD8 T
cells.
PMID- 10781588
TI - Pivotal role of reactive oxygen species as intracellular mediators of
hyperthermia-induced apoptosis.
AB - The effects of cellular antioxidant capacity on hyperthermia (HT)-induced
apoptosis and production of antiapoptotic heat shock proteins (HSPs) were
investigated in HL-60 cells and in HL-60AR cells that are characterized by an
elevated endogenous catalase activity. Exposure of both cell lines to 43 degrees
C for 1 h initiated apoptosis. Apoptosis peaked at 3-6 h after heat exposure in
the HL-60 cells. Whereas HL-60AR cells were partially protected against HT
induced apoptosis at these early time points, maximal levels of apoptosis were
detected later, i.e. 12-18 h after heat exposure. This differential induction of
apoptosis was directly correlated to the induction of the antiapoptotic HSP27 and
HSP70. In particular, in the HL-60 cells HSP27 was significantly induced at 12-18
h after exposure to 43 degrees C when apoptosis dropped. In contrast, coinciding
with the late onset of apoptosis in HL-60AR cells at that time HL-60AR cells
lacked a similar HSP response. In line with the higher antioxidant capacity HL
60AR cells accumulated reactive oxygen species to a lesser degree than HL-60
cells after heat treatment. Protection from HT-induced apoptosis as well as
diminished heat-induced HSP27 expression was also observed after cotreatment of
HL-60 cells with 43 degrees C and catalase but not with superoxide dismutase.
These data emphasize the pivotal role of reactive oxygen species for HT induced
pro- and antiapoptotic pathways.
PMID- 10781589
TI - Reconstitution of an endothelial nitric-oxide synthase (eNOS), hsp90, and
caveolin-1 complex in vitro. Evidence that hsp90 facilitates calmodulin
stimulated displacement of eNOS from caveolin-1.
AB - The activity of endothelial nitric-oxide synthase (eNOS) is regulated by its
subcellular localization, phosphorylation and through its interaction with
different proteins. The association of eNOS with caveolin-1 (Cav) is believed to
maintain eNOS in an inactive state; however, increased association of eNOS to
heat shock protein 90 (hsp90) is observed following activation. In this study, we
investigate the relationship between caveolin and hsp90 as opposing regulatory
proteins on eNOS function. Immunoprecipitation of Cav-1 from bovine lung
microvascular endothelial cells shows that eNOS and hsp90 are present in the Cav
1 complex. eNOS and hsp90 from the lysate also interact with exogenous
glutathione S-transferase-linked caveolin-1 (GST-Cav), and the addition of
calcium-activated calmodulin (CaM) to the GST-Cav complex partially inhibited the
association of eNOS and hsp90. Purified eNOS associates with GST-Cav specifically
through the caveolin-scaffolding domain (residues 82-101); however, the addition
of CaM slightly, but nonstatistically, reduces eNOS binding to GST-Cav. When
hsp90 is present in the binding reaction, the addition of increasing
concentrations of CaM significantly displaces eNOS and hsp90 from GST-Cav. eNOS
enzymatic activity is also less sensitive to inhibition by the caveolin
scaffolding peptide (residues 82-101) when eNOS is prebound to hsp90.
Collectively, our results show that the actions of CaM on eNOS dissociation from
caveolin are facilitated in the presence of hsp90.
PMID- 10781590
TI - Identification of CIP-1-associated regulator of cyclin B (CARB), a novel p21
binding protein acting in the G2 phase of the cell cycle.
AB - The cyclin-dependent kinase inhibitor p21(cip1) regulates cell cycle progression,
DNA replication, and DNA repair by binding to specific cellular proteins through
distinct amino- and carboxyl-terminal protein binding motifs. We have identified
a novel human gene, CARB (CIP-1-associated regulator of cyclin B), whose product
interacts with the p21 carboxyl terminus. Immunocytochemical analysis
demonstrates that the CARB protein is perinuclear and predominantly associated
with the centrosome and mitotic spindle poles. In addition, CARB is also able to
associate with cyclin B1, a key regulator of mitosis. However, cyclin B1-CARB
complex formation occurs preferentially in the absence of p21. Unexpectedly,
overexpression of CARB is associated with a growth-inhibitory and ultimately
lethal phenotype in p21(-/-) cells but not in p21(+/+) cells. These data identify
a novel mechanism that may underlie the effects of p21 in the G(2)/M phases of
the cell cycle.
PMID- 10781591
TI - Purification and molecular cloning of a novel essential component of the
apolipoprotein B mRNA editing enzyme-complex.
AB - Editing of apolipoprotein B (apoB) mRNA requires the catalytic component APOBEC-1
together with "auxiliary" proteins that have not been conclusively characterized
so far. Here we report the purification of these additional components of the
apoB mRNA editing enzyme-complex from rat liver and the cDNA cloning of the novel
APOBEC-1-stimulating protein (ASP). Two proteins copurified into the final active
fraction and were characterized by peptide sequencing and mass spectrometry:
KSRP, a 75-kDa protein originally described as a splicing regulating factor, and
ASP, a hitherto unknown 65-kDa protein. Separation of these two proteins resulted
in a reduction of APOBEC-1-stimulating activity. ASP represents a novel type of
RNA-binding protein and contains three single-stranded RNA-binding domains in the
amino-terminal half and a putative double-stranded RNA-binding domain at the
carboxyl terminus. Purified recombinant glutathione S-transferase (GST)-ASP, but
not recombinant GST-KSRP, stimulated recombinant GST-APOBEC-1 to edit apoB RNA in
vitro. These data demonstrate that ASP is the second essential component of the
apoB mRNA editing enzyme-complex. In rat liver, ASP is apparently associated with
KSRP, which may confer stability to the editing enzyme-complex with its substrate
apoB RNA serving as an additional auxiliary component.
PMID- 10781593
TI - Requirement of PIG-F and PIG-O for transferring phosphoethanolamine to the third
mannose in glycosylphosphatidylinositol.
AB - Many eukaryotic proteins are anchored by glycosylphosphatidylinositol (GPI) to
the cell surface membrane. The GPI anchor is linked to proteins by an amide bond
formed between the carboxyl terminus and phosphoethanolamine attached to the
third mannose. Here, we report the roles of two mammalian genes involved in
transfer of phosphoethanolamine to the third mannose in GPI. We cloned a mouse
gene termed Pig-o that encodes a 1101-amino acid PIG-O protein bearing regions
conserved in various phosphodiesterases. Pig-o knockout F9 embryonal carcinoma
cells expressed very little GPI-anchored proteins and accumulated the same major
GPI intermediate as the mouse class F mutant cell, which is defective in
transferring phosphoethanolamine to the third mannose due to mutant Pig-f gene.
PIG-O and PIG-F proteins associate with each other, and the stability of PIG-O
was dependent upon PIG-F. However, the class F cell is completely deficient in
the surface expression of GPI-anchored proteins. A minor GPI intermediate seen in
Pig-o knockout but not class F cells had more than three mannoses with
phosphoethanolamines on the first and third mannoses, suggesting that this GPI
may account for the low expression of GPI-anchored proteins. Therefore, mammalian
cells have redundant activities in transferring phosphoethanolamine to the third
mannose, both of which require PIG-F.
PMID- 10781592
TI - Regulated association of microtubule-associated protein 2 (MAP2) with Src and
Grb2: evidence for MAP2 as a scaffolding protein.
AB - Microtubule-associated protein 2 (MAP2) and tau, which is involved in Alzheimer's
disease, are major cytoskeletal proteins in neurons. These proteins are involved
in microtubule assembly and stability. To further characterize MAP2, we took a
strategy of identifying potential MAP2 binding partners. The low molecular weight
MAP2c protein has 11 PXXP motifs that are conserved across species, and these
PXXP motifs could be potential ligands for Src homology 3 (SH3) domains. We
tested for MAP2 interaction with SH3 domain-containing proteins. All neuronal
MAP2 isoforms bound specifically to the SH3 domains of c-Src and Grb2 in an in
vitro glutathione S-transferase-SH3 pull-down assay. Interactions between
endogenous proteins were confirmed by co-immunoprecipitation using brain lysate.
All three proteins were also found co-expressed in neuronal cell bodies and
dendrites. Surprisingly, the SH3 domain-binding site was mapped to the
microtubule-binding domain that contains no PXXP motif. Src bound primarily the
soluble, non-microtubule-associated MAP2c in vitro. This specific MAP2/SH3 domain
interaction was inhibited by phosphorylation of MAP2c by the mitogen-activated
protein kinase extracellular signal-regulated kinase 2 but not by protein kinase
A. This phosphorylation-regulated association of MAP2 with proteins of
intracellular signal transduction pathways suggests a possible link between
cellular signaling and neuronal cytoskeleton, with MAP2 perhaps acting as a
molecular scaffold upon which cytoskeleton-modifying proteins assemble and
dissociate in response to neuronal activity.
PMID- 10781594
TI - Characterization of a phosphoinositide-mediated odor transduction pathway reveals
plasma membrane localization of an inositol 1,4, 5-trisphosphate receptor in
lobster olfactory receptor neurons.
AB - The role of phosphoinositide signaling in olfactory transduction is still being
resolved. Compelling functional evidence for the transduction of odor signals via
phosphoinositide pathways in olfactory transduction comes from invertebrate
olfactory systems, in particular lobster olfactory receptor neurons. We now
provide molecular evidence for two components of the phosphoinositide signaling
pathway in lobster olfactory receptor neurons, a G protein alpha subunit of the
G(q) family and an inositol 1,4, 5-trisphosphate-gated channel or an inositol
1,4,5-trisphosphate (IP(3)) receptor. Both proteins localize to the site of
olfactory transduction, the outer dendrite of the olfactory receptor neurons.
Furthermore, the IP(3) receptor localizes to membranes in the ciliary
transduction compartment of these cells at both the light microscopic and
electron microscopic levels. Given the absence of intracellular organelles in the
sub-micron diameter olfactory cilia, this finding indicates that the IP(3)
receptor is associated with the plasma membrane and provides the first definitive
evidence for plasma membrane localization of an IP(3)R in neurons. The
association of the IP(3) receptor with the plasma membrane may be a novel
mechanism for regulating intracellular cations in restricted cellular
compartments of neurons.
PMID- 10781595
TI - The molecular chaperones Hsp90 and Hsc70 are both necessary and sufficient to
activate hormone binding by glucocorticoid receptor.
AB - Glucocorticoid receptors must be complexed with Hsp90 in order to bind steroids,
and it has been reported that at least three other proteins, Hop, Hsc70, and a J
domain protein (either Hsp40 or Ydj1), are required for formation of active Hsp90
steroid receptor complex. In the present study, we reinvestigated activation of
stripped steroid receptors isolated from either L cells or WCL2 cells.
Surprisingly, we found, using highly purified proteins, that only Hsp90 and Hsc70
are required for the activation of glucocorticoid receptors in the presence of
steroids; in the absence of steroids, either p23 or molybdate are also required
as reported previously. Addition of Hop or Ydj1 had no affect on the rate or
magnitude of the activation of the stripped receptors, and quantitative Western
blots confirmed that neither Hop or Hsp40 were present in our protein
preparations or in the stripped receptors. Furthermore, a truncated recombinant
Hsp70 that does not bind Hop or Hsp40 was as effective as wild-type Hsp70 in
activating stripped receptor. Since Hsc70 does not bind directly to Hsp90 but
both proteins bind to Hop, it has been suggested that Hop acts as a bridge
between Hsp90 and Hsp70. However, we found that after Hsc70 or Hsp90 bind
directly to the stripped receptors, they are fully reactivated by Hsp90 or Hsc70,
respectively. We, therefore, conclude that Hsp90 and Hsc70 bind independently to
stripped glucocorticoid receptors and alone are sufficient to activate them to
bind steroids.
PMID- 10781596
TI - Molecular cloning and expression of a novel chondroitin 6-O-sulfotransferase.
AB - A novel human chondroitin 6-O-sulfotransferase, designated C6ST-2, was identified
by BLAST analysis of expressed sequence tag using the sequence of a previously
described human chondroitin 6-O-sulfotransferase (C6ST-1) as a probe. The new
cDNA sequence revealed an open reading frame coding for a protein of 486 amino
acids with a type II transmembrane protein topology. The amino acid sequence
displayed 24% identity to the human C6ST-1, and the highest sequence identity was
found in the COOH-terminal catalytic domain. The expression of a soluble
recombinant form of the protein in COS-1 cells produced an active
sulfotransferase with marked specificity for polymer chondroitin. In contrast,
keratan sulfate and oligosaccharides containing the Galbeta1-4GlcNAc sequence,
which are good acceptor substrates for the C6ST-1, hardly served as acceptors.
The identification of the reaction product indicated that the enzyme is a novel
chondroitin 6-O-sulfotransferase (C6ST-2) that mainly transfers sulfate to N
acetylgalactosamine. The coding region of C6ST-2 was contained in a single exon
and localized to chromosome Xp11. Northern blot analysis of human brain
poly(A)(+) RNA revealed a single transcript of 2.4 kilobase pairs. Reverse
transcription-polymerase chain reaction analysis showed that C6ST-2 is
developmentally regulated in various tissues with expression persisting through
adulthood in the spleen. Thus, we demonstrated the redundancy in chondroitin 6-O
sulfotransferases capable of forming chondroitin 6-sulfate, which is important
for understanding the mechanisms leading to specific changes in the sulfation
profile of chondroitin sulfate chains in various tissues during development and
malignant transformation.
PMID- 10781597
TI - Oncogenic Ras-mediated cell growth arrest and apoptosis are associated with
increased ubiquitin-dependent cyclin D1 degradation.
AB - The cellular responses to activated Ras vary depending on cell type. Normal cells
are often induced into pathways that lead to cell growth arrest, senescence,
and/or apoptosis in response to activated Ras expression. These are important
protective anti-tumorigenic responses that restrict the propagation of cells
bearing activated oncogenes. Here we show that induction of Ha-Ras(Val-12) in Rat
1 fibroblasts resulted in G(1) growth arrest and apoptosis with loss of viable
cells that is accompanied by a marked decrease in cyclin D1 levels via increased
ubiquitin-proteasome-dependent cyclin D1 turnover. This is in contrast with a rat
intestinal epithelial cell line in which induction of Ha-Ras(Val-12) results in
transformation associated with sustained proliferation and increased levels of
cyclin D1, that is not accompanied by anoikis or apoptosis. Expression of the
cyclin D1 mutant (T286A) that contains an alanine for threonine 286 substitution
and is resistant to ubiquitin-proteasome degradation in the Ha-Ras(Val-12)
expressing Rat-1 cells resulted in a sustained transformed phenotype with no
accumulation of cells in G(1). Inhibition of mitogen-activated protein kinase
(MEK1/2) pathway partially reversed the Ras-mediated decrease in cyclin D1.
Induction of Ha-Ras(Val-12) resulted in activation of Akt kinase and inactivation
of glycogen-synthase-3beta kinase that are associated with reduction of cyclin D1
protein. These results suggest that Ras-mediated cyclin D1 degradation in Rat-1
cells appears to be partially dependent on activation of mitogen-activated
protein kinase pathway and independent of glycogen-synthase-3beta kinase pathway.
PMID- 10781598
TI - The H subunit (Vma13p) of the yeast V-ATPase inhibits the ATPase activity of
cytosolic V1 complexes.
AB - V-ATPases are composed of a peripheral complex containing the ATP-binding sites,
the V(1) sector, attached to a membrane complex containing the proton pore, the
V(o) sector. In vivo, free, inactive V(1) and V(o) sectors exist in dynamic
equilibrium with fully assembled, active V(1) V(o) complexes, and this
equilibrium can be perturbed by changes in carbon source. Free V(1) complexes
were isolated from the cytosol of wild-type yeast cells and mutant strains
lacking V(o) subunit c (Vma3p) or V(1) subunit H (Vma13p). V(1) complexes from
wild-type or vma3Delta mutant cells were very similar, and contained all
previously identified yeast V(1) subunits except subunit C (Vma5p). These V(1)
complexes hydrolyzed CaATP but not MgATP, and CaATP hydrolysis rapidly
decelerated with time. V(1) complexes from vma13Delta cells contained all V(1)
subunits except C and H, and had markedly different catalytic properties. The
initial rate of CaATP hydrolysis was maintained for much longer. The complexes
also hydrolyzed MgATP, but showed a rapid deceleration in hydrolysis. These
results indicate that the H subunit plays an important role in silencing
unproductive ATP hydrolysis by cytosolic V(1) complexes, but suggest that other
mechanisms, such as product inhibition, may also play a role in silencing in
vivo.
PMID- 10781599
TI - Endoplasmic reticulum retention determinants in the transmembrane and linker
domains of cytochrome P450 2C1.
AB - The cytochrome P450 2C1 N-terminal signal anchor sequence mediates direct
retention of the protein in the endoplasmic reticulum and consists of a
hydrophobic transmembrane domain, residues 3-20, followed by a hydrophilic
linker, residues 21-28. Fusions of the N-terminal 21 or 28 amino acids of P450
2C1 to green fluorescent protein resulted in endoplasmic reticulum localization
of the chimera in transfected cells. Disruption of microtubules by nocodazole
treatment resulted in redistribution into a punctate pattern for the 1-21, but
not for the 1-28, chimera indicating that the linker was preventing transport
from the endoplasmic reticulum but was not required for retrieval to the
endoplasmic reticulum from the pre-Golgi compartment. In the 1-28 chimera,
mutations of residues 21-23 (KQS) in the linker resulted in redistribution of the
chimera after nocodazole treatment. Mutations in the transmembrane domain
affected both direct retention in the endoplasmic reticulum and retrieval from
the pre-Golgi compartment, and although structural requirements for each process
are distinct, in both cases the arrangement of amino acids and distribution of
hydrophobicity are critical. In contrast, the linker region exhibits a sequence
specific requirement for direct retention in the endoplasmic reticulum.
PMID- 10781600
TI - Signaling from G protein-coupled receptors to ERK5/Big MAPK 1 involves Galpha q
and Galpha 12/13 families of heterotrimeric G proteins. Evidence for the
existence of a novel Ras AND Rho-independent pathway.
AB - The regulation of gene expression by cell surface receptors often involves the
stimulation of signaling pathways including one or more members of the MAPK
superfamily of serine-threonine kinases. Upon their activation in the cytosol,
MAPKs can translocate to the nucleus and affect the activity of a variety of
transcription factors. Recently, it has been observed that a novel member of the
MAPK superfamily, ERK5, can be potently activated by transforming G protein
coupled receptors (GPCRs) and that ERK5 participates in the regulation of c-jun
expression through the activation of MEF2 transcription factors. How cell surface
receptors, including GPCRs, stimulate ERK5 is still poorly understood. In this
study, we have used transiently transfected COS-7 cells to begin delineating the
biochemical route linking GPCRs to ERK5. We show that receptors that can couple
to the G(q) and G(12/13) families of heterotrimeric G proteins, m1 and thrombin
receptors, respectively, but not those coupled to G(i), such as m2 receptors, are
able to regulate the activity of ERK5. To investigate which heterotrimeric G
proteins signal to ERK5, we used a chimeric system by which Galpha(q)- and
Galpha(13)-mediated signaling pathways can be conditionally activated upon ligand
stimulation. Using this system, as well as the expression of activated forms of G
protein subunits, we show that the Galpha(q) and Galpha(12/13) families of
heterotrimeric G proteins, but not the Galpha(i), Galpha(s), and betagamma
subunits, are able to regulate ERK5. Furthermore, we provide evidence that the
stimulation of ERK5 by GPCRs involves a novel signaling pathway, which is
distinct from those regulated by Ras and Rho GTPases.
PMID- 10781601
TI - Molecular cloning and expression of two distinct human chondroitin 4-O
sulfotransferases that belong to the HNK-1 sulfotransferase gene family.
AB - Using an expression cloning strategy, the cDNA encoding the human HNK-1
sulfotransferase (HNK-1ST) has been cloned. During this cloning we found that HNK
1ST and other Golgi-associated sulfotransferases cloned before share homologous
sequences including the RDP motif (Ong, E., Yeh, J.-C., Ding, Y., Hindsgaul, O.,
and Fukuda, M. (1998) J. Biol. Chem. 223, 5190-5195). Using this conserved
sequence in HNK-1ST as a probe, we identified two expressed sequence tags in EST
data base which have 31.6 and 30.7% identity with HNK-1ST at the amino acid
levels. Expression of these two full-length cDNAs failed to form HNK-1 glycan nor
to add sulfate to CD34 or NCAM. Surprisingly, proteins expressed by these cDNAs
transferred sulfate to the C-4 position of N-acetylgalactosamine in chondroitin
and desulfated dermatan sulfate, thus we named these two enzymes, chondroitin 4-O
sulfotransferase 1 and -2 (C4ST-1 and C4ST-2). Both C4ST-1 and C4ST-2, however,
did not form 4, 6-di-O-sulfated N-acetylgalactosamine when chondroitin sulfate C
was used as an acceptor. Moreover, analysis of (35)S-labeled dermatan sulfate
formed by C4ST-1 indicate that sulfation preferentially took place in GlcA-
>GalNAc unit than in IdoA-->GalNAc unit, suggesting that 4-O-sulfation at N
acetylgalactosamine may precede epimerization of glucuronic acid to iduronic acid
during dermatan sulfate biosynthesis. Northern analysis demonstrated that the
transcript for C4ST-1 is predominantly expressed in peripheral leukocytes and
hematopoietic tissues while the C4ST-2 transcript is more widely expressed in
various tissues. These results indicate C4ST-1 and C4ST-2 play complementary
roles in chondroitin and dermatan sulfate synthesis in different tissues.
PMID- 10781602
TI - The C terminus of mouse macrophage inducible nitric-oxide synthase attenuates
electron flow through the flavin domain.
AB - The sequences of nitric-oxide synthase (NOS) flavin domains closely resemble that
of NADPH-cytochrome P450 reductase (CPR), with the exception of a few regions.
One such region is the C terminus; all NOS isoforms are 20-40 amino acids longer
than CPR, forming a "tail" that is absent in CPR. To investigate its function, we
removed the 21-amino acid C-terminal tail from murine macrophage inducible NOS
(iNOS) holoenzyme and from a flavin domain construct. Both the truncated
holoenzyme and reductase domain exhibited cytochrome c reductase activities that
were 7-10-fold higher than the nontruncated forms. The truncated holoenzyme
catalyzed NO formation approximately 20% faster than the intact form. Using
stopped-flow spectrophotometry, we demonstrated that electron transfer into and
between the two flavins and from the flavin to the heme domain is 2-5-fold faster
in the absence of the C-terminal tail. The heme-nitrosyl complex, formed in all
NOS isoforms during NO catalysis, is 5-fold less stable in truncated iNOS.
Although both CPR and intact NOS can exist in a stable, one electron-reduced
semiquinone form, neither the truncated holoenzyme nor the truncated flavin
domain demonstrate such a form. We propose that this C-terminal tail curls back
to interact with the flavin domain in such a way as to modulate the interaction
between the two flavin moieties.
PMID- 10781603
TI - Type II cAMP-dependent protein kinase-deficient Drosophila are viable but show
developmental, circadian, and drug response phenotypes.
AB - We identified a unique type II cAMP-dependent protein kinase regulatory subunit
(PKA-RII) gene in Drosophila melanogaster and a severely hypomorphic if not null
mutation, pka-RII(EP(2)2162). Extracts from pka- RII(EP(2)2162) flies selectively
lack RII-specific autophosphorylation activity and show significantly reduced
cAMP binding activity, attributable to the loss of functional PKA-RII. pka
RII(EP(2)2162) shows 2-fold increased basal PKA activity and approximately 40% of
normal cAMP-inducible PKA activity. pka-RII(EP(2)2162) is fully viable but
displays abnormalities of ovarian development and multiple behavioral phenotypes
including arrhythmic circadian locomotor activity, decreased sensitivity to
ethanol and cocaine, and a lack of sensitization to repeated cocaine exposures.
These findings implicate type II PKA activity in these processes in Drosophila
and imply a common role for PKA signaling in regulating responsiveness to cocaine
and alcohol.
PMID- 10781604
TI - Rsp5 WW domains interact directly with the carboxyl-terminal domain of RNA
polymerase II.
AB - RSP5 is an essential gene in Saccharomyces cerevisiae and was recently shown to
form a physical and functional complex with RNA polymerase II (RNA pol II). The
amino-terminal half of Rsp5 consists of four domains: a C2 domain, which binds
membrane phospholipids; and three WW domains, which are protein interaction
modules that bind proline-rich ligands. The carboxyl-terminal half of Rsp5
contains a HECT (homologous to E6-AP carboxyl terminus) domain that catalytically
ligates ubiquitin to proteins and functionally classifies Rsp5 as an E3 ubiquitin
protein ligase. The C2 and WW domains are presumed to act as membrane
localization and substrate recognition modules, respectively. We report that the
second (and possibly third) Rsp5 WW domain mediates binding to the carboxyl
terminal domain (CTD) of the RNA pol II large subunit. The CTD comprises a
heptamer (YSPTSPS) repeated 26 times and a PXY core that is critical for
interaction with a specific group of WW domains. An analysis of synthetic
peptides revealed a minimal CTD sequence that is sufficient to bind to the second
Rsp5 WW domain (Rsp5 WW2) in vitro and in yeast two-hybrid assays. Furthermore,
we found that specific "imperfect" CTD repeats can form a complex with Rsp5 WW2.
In addition, we have shown that phosphorylation of this minimal CTD sequence on
serine, threonine and tyrosine residues acts as a negative regulator of the Rsp5
WW2-CTD interaction. In view of the recent data pertaining to phosphorylation
driven interactions between the RNA pol II CTD and the WW domain of Ess1/Pin1, we
suggest that CTD dephosphorylation may be a prerequisite for targeted RNA pol II
degradation.
PMID- 10781605
TI - Kinetics of the interaction of translation factor SelB from Escherichia coli with
guanosine nucleotides and selenocysteine insertion sequence RNA.
AB - The kinetics of the interaction of GTP and GDP with SelB, the specific
translation factor for the incorporation of selenocysteine into proteins, have
been investigated using the stopped-flow method. Useful signals were obtained
using intrinsic (i.e. tryptophan) fluorescence, the fluorescence of
methylanthraniloyl derivatives of nucleotides, or fluorescence resonance energy
transfer from tryptophan to the methylanthraniloyl group. The affinities of SelB
for GTP (K(d) = 0.74 micrometer) and GDP (K(d) = 13.4 micrometer) were
considerably lower than those of other translation factors. Of functional
significance is the fact that the rate constant for GDP release from its complex
with SelB (15 s(-)(1)) is many orders of magnitude larger than for elongation
factor Tu, explaining why a GDP/GTP exchange factor is not required for the
action of SelB. In contrast, the rate of release of GTP is 2 orders of magnitude
slower and not significantly faster than for elongation factor Tu. Using a
fluorescently labeled 17-nucleotide RNA minihelix that represents a binding site
for the protein and that is part of the fdhF selenocysteine insertion sequence
element positioned immediately downstream of the UGA triplet coding for
selenocysteine incorporation, the kinetics of the interaction were studied. The
high affinity of the interaction (K(d) approximately 1 nm) appeared to be
increased even further when selenocysteyl-tRNA(Sec) was bound to SelB, but to be
independent of the presence or nature of the guanosine nucleotide at the active
site. These results suggest that the affinity of SelB for its RNA binding site is
maximized when charged tRNA is bound and decreases to allow dissociation and
reading of codons downstream of the selenocysteine codon after selenocysteine
peptide bond formation.
PMID- 10781607
TI - The iscS gene in Escherichia coli is required for the biosynthesis of 4
thiouridine, thiamin, and NAD.
AB - IscS, a cysteine desulfurase implicated in the repair of Fe-S clusters, was
recently shown to act as a sulfurtransferase in the biosynthesis of 4-thiouridine
(s(4)U) in tRNA (Kambampati, R., and Lauhon, C. T. (1999) Biochemistry 38, 16561
16568). In frame deletion of the iscS gene in Escherichia coli results in a
mutant strain that lacks s(4)U in its tRNA. Assays of cell-free extracts isolated
from the iscS(-) strain confirm the complete loss of tRNA sulfurtransferase
activity. In addition to lacking s(4)U, the iscS(-) strain requires thiamin and
nicotinic acid for growth in minimal media. The thiamin requirement can be
relieved by the addition of the thiamin precursor 5-hydroxyethyl-4
methylthiazole, indicating that iscS is required specifically for thiazole
biosynthesis. The growth rate of the iscS(-) strain is half that of the parent
strain in rich medium. When the iscS(-) strain is switched from rich to minimal
medium containing thiamin and nicotinate, growth is preceded by a considerable
lag period relative to the parent strain. Addition of isoleucine results in a
significant reduction in the duration of this lag phase. To examine the thiazole
requirement, we have reconstituted the in vitro biosynthesis of ThiS
thiocarboxylate, the ultimate sulfur donor in thiazole biosynthesis, and we show
that IscS mobilizes sulfur for transfer to the C-terminal carboxylate of ThiS.
ThiI, a known factor involved in both thiazole and s(4)U synthesis, stimulates
this sulfur transfer step by 7-fold. Extracts from the iscS(-) strain show
significantly reduced activity in the in vitro synthesis of ThiS thiocarboxylate.
Transformation of the iscS(-) strain with an iscS expression plasmid complemented
all of the observed phenotypic effects of the deletion mutant. Of the remaining
two nifS-like genes in E. coli, neither can complement loss of iscS when each is
overexpressed in the iscS(-) strain. Thus, IscS plays a significant and specific
role at the top of a potentially broad sulfur transfer cascade that is required
for the biosynthesis of thiamin, NAD, Fe-S clusters, and thionucleosides.
PMID- 10781606
TI - Molecular cloning and characterization of a human mitochondrial ceramidase.
AB - We have recently purified a rat brain membrane-bound nonlysosomal ceramidase (El
Bawab, S., Bielawska, A., and Y. A. Hannun (1999) J. Biol. Chem. 274, 27948
27955). Using peptide sequences obtained from the purified rat brain enzyme, we
report here the cloning of the human isoform. The deduced amino acid sequence of
the protein did not show any similarity with proteins of known function but was
homologous to three putative proteins from Arabidospis thaliana, Mycobacterium
tuberculosis, and Dictyostelium discoideum. Several blocks of amino acids were
highly conserved in all of these proteins. Analysis of the protein sequence
revealed the presence at the N terminus of a signal peptide followed by a
putative myristoylation site and a putative mitochondrial targeting sequence. The
predicted molecular mass was 84 kDa, and the isoelectric point was 6.69, in
agreement with rat brain purified enzyme. Northern blot analysis of multiple
human tissues showed the presence of a major band corresponding to a size of 3.5
kilobase. Analysis of this major band on the blot indicated that the enzyme is
ubiquitously expressed with higher levels in kidney, skeletal muscle, and heart.
The enzyme was then overexpressed in HEK 293 and MCF7 cells using the pcDNA3.
1/His-ceramidase construct, and ceramidase activity (at pH 9.5) increased by 50-
and 12-fold, respectively. Next, the enzyme was characterized using lysate of
overexpressing cells. The results confirmed that the enzyme catalyzes the
hydrolysis of ceramide in the neutral alkaline range and is independent of
cations. Finally, a green fluorescent protein-ceramidase fusion protein was
constructed to investigate the localization of this enzyme. The results showed
that the green fluorescent protein-ceramidase fusion protein presented a
mitochondrial localization pattern and colocalized with mitochondrial specific
probes. These results demonstrate that this novel ceramidase is a mitochondrial
enzyme, and they suggest the existence of a topologically restricted pathways of
sphingolipid metabolism.
PMID- 10781608
TI - The top of the inserted-like domain of the integrin lymphocyte function
associated antigen-1 beta subunit contacts the alpha subunit beta -propeller
domain near beta-sheet 3.
AB - We find that monoclonal antibody YTA-1 recognizes an epitope formed by a
combination of the integrin alpha(L) and beta(2) subunits of LFA-1. Using
human/mouse chimeras of the alpha(L) and beta(2) subunits, we determined that YTA
1 binds to the predicted inserted (I)-like domain of the beta(2) subunit and the
predicted beta-propeller domain of the alpha(L) subunit. Substitution into mouse
LFA-1 of human residues Ser(302) and Arg(303) of the beta(2) subunit and Pro(78),
Thr(79), Asp(80), Ile(365), and Asn(367) of the alpha(L) subunit is sufficient to
completely reconstitute YTA-1 reactivity. Antibodies that bind to epitopes that
are nearby in models of the I-like and beta-propeller domains compete with YTA-1
monoclonal antibody for binding. The predicted beta-propeller domain of integrin
alpha subunits contains seven beta-sheets arranged like blades of a propeller
around a pseudosymmetry axis. The antigenic residues cluster on the bottom of
this domain in the 1-2 loop of blade 2, and on the side of the domain in beta
strand 4 of blade 3. The I domain is inserted between these blades on the top of
the beta-propeller domain. The antigenic residues in the beta subunit localize to
the top of the I-like domain near the putative Mg(2+) ion binding site. Thus, the
I-like domain contacts the bottom or side of the beta-propeller domain near beta
sheets 2 and 3. YTA-1 preferentially reacts with activated LFA-1 and is a
function-blocking antibody, suggesting that conformational movements occur near
the interface it defines between the LFA-1 alpha and beta subunits.
PMID- 10781609
TI - Up-regulation of caveolin attenuates epidermal growth factor signaling in
senescent cells.
AB - Senescent human diploid fibroblasts do not respond to growth factors like
epidermal growth factor (EGF), although they have a normal level of receptors and
downstream signaling molecules. To examine the mechanism of signaling
attenuation, we investigated Erk activation after EGF stimulation in senescent
cells. Senescent cells did not phosphorylate Erk-1/2 after EGF stimulation,
whereas young cells did. In those senescent cells, we found an increased level of
caveolin proteins and strong interactions between caveolin-1 and EGF receptor.
Electron microscopic analysis demonstrated an increased number of caveolae
structures in senescent cells. More interestingly, brain, spleen, and lung from
26-month-old rats showed substantial increases of caveolin proteins. However, in
the case of p53-induced senescence, caveolin-1 was not induced, and EGF
stimulation phosphorylated Erk-1/2 as much as young control cells. Finally, we
overexpressed caveolin-1 in young human diploid fibroblasts in which the
activation of Erk-1/2 upon EGF stimulation was significantly suppressed. These
results suggest that the unresponsiveness of senescent fibroblasts to EGF
stimulation may be due to the overexpression of caveolins, which seems to be
independent of growth arrest and other aging phenotypes.
PMID- 10781610
TI - Identification of the enzymatic active site of CD38 by site-directed mutagenesis.
AB - CD38 is a ubiquitous protein originally identified as a lymphocyte antigen and
recently also found to be a multifunctional enzyme participating in the synthesis
and metabolism of two Ca(2+) messengers, cyclic ADP-ribose (cADPR) and nicotinic
acid adenine dinucleotide phosphate. It is homologous to Aplysia ADP-ribosyl
cyclase, where the crystal structure has been determined. Residues of CD38
corresponding to those at the active site of the Aplysia cyclase were
mutagenized. Changing Glu-226, which corresponded to the catalytic residue of the
cyclase, to Asp, Asn, Gln, Leu, or Gly eliminated essentially all enzymatic
activities of CD38, indicating it is most likely the catalytic residue.
Photoaffinity labeling showed that E226G, nevertheless, retained substantial NAD
binding activity. The secondary structures of these inactive mutants as measured
by circular dichroism were essentially unperturbed as compared with the wild
type. Other nearby residues were also investigated. The mutants D147V and E146L
showed 7- and 19-fold reduction in NADase activity, respectively. The cADPR
hydrolase activity of the two mutants was similarly reduced. Asp-155, on the
other hand, was crucial for the GDP-ribosyl cyclase activity since its
substitution with either Glu, Asn, or Gln stimulated the activity 3-15-fold,
whereas other activities remained essentially unchanged. In addition to these
acidic residues, two tryptophans were also important, since all enzyme activities
of W125F, W125Y, W189G and W189Y were substantially reduced. This is consistent
with the two tryptophans serving a substrate positioning function. A good
correlation was observed when the NADase activity of all the mutants was plotted
against the cADPR hydrolase activity. Homology modeling revealed all these
critical residues are clustered in a pocket near the center of the CD38 molecule.
The results indicate a strong structural homology between the active sites of
CD38 and the Aplysia cyclase.
PMID- 10781611
TI - The adapter protein LAT enhances fcgamma receptor-mediated signal transduction in
myeloid cells.
AB - FcgammaR clustering in monocytes initiates a cascade of signaling events that
culminate in biological responses such as phagocytosis, production of
inflammatory cytokines, and generation of reactive oxygen species. We have
identified and determined the function of the adapter protein linker of
activation of T cell (LAT) in FcgammaR-mediated signaling and function.
Clustering of FcgammaRs on the human monocytic cell line, THP-1, induces
phosphorylation of a major 36-kDa protein which immunoreacts with anti-LAT
antisera. Our data indicate that although both the 36-kDa and 38-kDa isoforms of
LAT are expressed in THP-1 and U937 human monocytic cells, FcgammaR clustering
induces phosphorylation of the 36-kDa isoform only. Co-immunoprecipitation
experiments revealed a constitutive association of p36 LAT with both FcgammaRI
and FcgammaRIIa immunoprecipitates, and an activation-induced association of LAT
with PLCgamma1, Grb2, and the p85 subunit of phosphatidylinositol 3-kinase.
Transient transfection experiments in COS-7 cells indicated that overexpression
of a wild type but not a dominant-negative LAT, that is incapable of binding to
p85, enhances phagocytosis by FcgammaRI. Furthermore, bone marrow-derived
macrophages from LAT-deficient mice displayed reduced phagocytic efficiency in
comparison to the macrophages from wild-type mice. Thus, we conclude that p36 LAT
serves to enhance FcgammaR-induced signal transduction in myeloid cells.
PMID- 10781612
TI - Identification and developmental expression of inhibitor of caspase-activated
DNase (ICAD) in Drosophila melanogaster.
AB - DNA fragmentation, a hallmark of apoptosis, is regulated by a specific nuclease
called caspase-activated DNase (CAD) and its inhibitor (ICAD). When cell lysates
from Drosophila S2 cells were chemically denatured and the denatured proteins
were removed after dialysis, the supernatant inhibited Drosophila CAD (dCAD). To
identify the inhibitor, we tested recombinant DREP-1, which was previously
identified using the Drosophila EST data base and found it also inhibited dCAD
DNase. An antibody against DREP-1 inhibited the ICAD activity in the S2 cell
extracts, confirming the identification of DREP-1 as a Drosophila homolog of ICAD
(dICAD). The recombinant DREP-1/dICAD was cleaved at a specific site by human
caspase 3 as well as by extracts prepared from S2 cells undergoing apoptosis.
Biochemical fractionation and immunoprecipitation of dICAD from S2 cell extracts
indicated that dICAD is complexed with dCAD in proliferating cells. The
expression of the caspase-resistant form of dICAD/DREP-1 in a Drosophila neuronal
cell line prevented the apoptotic DNA fragmentation. Northern hybridization and
the immunohistochemical analyses revealed that the expression of the dICAD gene
is developmentally regulated.
PMID- 10781613
TI - Cloning and expression of a novel MAPKK-like protein kinase, lymphokine-activated
killer T-cell-originated protein kinase, specifically expressed in the testis and
activated lymphoid cells.
AB - A novel protein kinase, TOPK (T-LAK cell-originated protein kinase), was isolated
from a lymphokine-activated killer T (T-LAK) cell subtraction cDNA fragment
library. The open reading frame of the TOPK gene encodes a protein of 322 amino
acids, possessing a protein kinase domain profile. The cap site analysis of the
5'-end of TOPK mRNA revealed two forms, a major full-length form and a minor
spliced form at the 5'-site, both encoding the same protein. A BLAST homology
search and phylogenetic analysis indicated that TOPK is related to dual specific
mitogen-activated protein kinase kinase (MAPKK). The transfection of the TOPK
gene to COS-7 cells up-regulated a phosphorylation of p38 MAPK but not ERK1/2 or
SAPK/JNK. Gel precipitation study indicated that TOPK protein can be associated
with p38 in vitro. Tissue distribution of TOPK mRNA expression was specific for
the testis, T-LAK cells, activated lymphoid cells, and lymphoid tumors. On the
other hand, deactivated T-LAK cells did not show TOPK mRNA expression. These data
suggest that TOPK is a newly identified member of a novel MEK3/6-related MAPKK
that may be enrolled in the activation of lymphoid cells and support testicular
functions.
PMID- 10781615
TI - The homeodomain protein Barx2 contains activator and repressor domains and
interacts with members of the CREB family.
AB - Barx1 and Barx2 are homeodomain proteins originally identified using regulatory
elements of genes encoding certain cell adhesion molecules (CAMs). In the present
study, we characterize regions of Barx2 that bind to regulatory elements of genes
encoding three CAMs, L1, neuron-glia CAM (Ng-CAM), and neural CAM (N-CAM), and
identify domains of Barx2 that regulate N-CAM transcription. The homeodomain of
Barx2 was sufficient for binding to homeodomain binding sites (HBS) from all
three CAM genes. The presence of a 17-amino acid Barx basic region resulted in a
2-fold decrease in binding to HBS sequences from the Ng-CAM and L1 genes, whereas
it led to a 6.5-fold increase in binding to the HBS from the N-CAM promoter.
Thus, the Barx basic region influences the strength and specificity of Barx2
binding to DNA. In co-transfection experiments, Barx2 repressed N-CAM promoter
activity. A 24-residue N-terminal region of Barx2 was essential for repression.
When this region was absent, Barx2 activated the N-CAM promoter. A 63-residue C
terminal domain was required for this activation. In GST pull-down experiments,
Barx2 bound to proteins of the CREB family, CREB1 and ATF2. Overall, these
findings provide a framework for understanding developmental and physiological
contexts that influence repressor or activator functions of Barx2.
PMID- 10781614
TI - p38 MAPK and NF-kappa B collaborate to induce interleukin-6 gene expression and
release. Evidence for a cytoprotective autocrine signaling pathway in a cardiac
myocyte model system.
AB - In cardiac myocytes, the stimulation of p38 MAPK by the MAPKK, MKK6, activates
the transcription factor, NF-kappaB, and protects cells from apoptosis. In the
present study in primary neonatal rat cardiac myocytes, constitutively active
MKK6, MKK6(Glu), bound to IkappaB kinase (IKK)-beta and stimulated its abilities
to phosphorylate IkappaB and to activate NF-kappaB. MKK6(Glu) induced NF-kappaB
dependent interleukin (IL)-6 transcription and IL-6 release in a p38-dependent
manner. IL-6 protected myocardial cells against apoptosis. Like IL-6, TNF-alpha,
which activates both NF-kappaB and p38, also induced p38-dependent IL-6
expression and release and protected myocytes from apoptotis. While TNF-alpha was
relatively ineffective, IL-6 activated myocardial cell STAT3 by about 8-fold,
indicating a probable role for this transcription factor in IL-6-mediated
protection from apoptosis. TNF-alpha-mediated IL-6 induction was inhibited by a
kinase-inactive form of the MAPKKK, TGF-beta activated protein kinase (Tak1),
which is known to activate p38 and NF-kappaB in other cell types. Thus, by
stimulating both p38 and NF-kappaB, Tak1-activating cytokines, like TNF-alpha,
can induce IL-6 expression and release. Moreover, the myocyte-derived IL-6 may
then function in an autocrine and/or paracrine fashion to augment myocardial cell
survival during stresses that activate p38.
PMID- 10781616
TI - A novel binding factor facilitates nuclear translocation and transcriptional
activation function of the pituitary tumor-transforming gene product.
AB - Pituitary tumor-transforming gene (PTTG) is a recently characterized oncogene
whose expression product contains a transcriptional activation domain at the C
terminus. To understand the mechanisms involved in PTTG biological functions, we
used yeast two-hybrid screening to identify proteins that interact with PTTG.
This study reports the isolation and characterization of a novel PTTG-binding
factor (PBF). PBF contains an open reading frame of 179 amino acids with a
predicted molecular mass of 22 kDa. In Northern blot analyses, PBF mRNA was
ubiquitously expressed in human tissues. Glutathione S-transferase pull-down and
co-immunoprecipitation assays demonstrate that PBF interacts specifically with
PTTG under both in vitro and in vivo conditions. The PTTG binding domain in PBF
was located within the C-terminal 30-amino acid region that contain a nuclear
localization signal. Immunofluorescence and subcellular fractionation studies
showed that PTTG is predominantly expressed in the cytoplasm with partial nuclear
localization, whereas PBF is localized both in the cytoplasm and the nucleus. The
interaction between PBF and PTTG facilitated PTTG translocation from the
cytoplasm to the nucleus. Furthermore, PBF is required for transcriptional
activation of basic fibroblast growth factor by PTTG. In summary, we have
characterized a novel PTTG-binding protein that facilitates PTTG nuclear
translocation and potentiates its transcriptional activation function.
PMID- 10781617
TI - The pgdA gene encodes for a peptidoglycan N-acetylglucosamine deacetylase in
Streptococcus pneumoniae.
AB - Analytical work on the fractionation of the glycan strands of Streptococcus
pneumoniae cell wall has led to the observation that an unusually high proportion
of hexosamine units (over 80% of the glucosamine and 10% of the muramic acid
residues) was not N-acetylated, explaining the resistance of the peptidoglycan to
the hydrolytic action of lysozyme, a muramidase that cleaves in the glycan
backbone. A gene, pgdA, was identified as encoding for the peptidoglycan N
acetylglucosamine deacetylase A with amino acid sequence similarity to fungal
chitin deacetylases and rhizobial NodB chitooligosaccharide deacetylases.
Pneumococci in which pgdA was inactivated by insertion duplication mutagenesis
produced fully N-acetylated glycan and became hypersensitive to exogenous
lysozyme in the stationary phase of growth. The pgdA gene may contribute to
pneumococcal virulence by providing protection against host lysozyme, which is
known to accumulate in high concentrations at infection sites.
PMID- 10781618
TI - Clinical features of Nipah virus encephalitis among pig farmers in Malaysia.
AB - BACKGROUND: Between September 1998 and June 1999, there was an outbreak of severe
viral encephalitis due to Nipah virus, a newly discovered paramyxovirus, in
Malaysia. METHODS: We studied the clinical features of the patients with Nipah
virus encephalitis who were admitted to a medical center in Kuala Lumpur. The
case definition was based on epidemiologic, clinical, cerebrospinal fluid, and
neuroimaging findings. RESULTS: Ninety-four patients with Nipah virus infection
were seen from February to June 1999 (mean age, 37 years; ratio of male patients
to female patients, 4.5 to 1). Ninety-three percent had had direct contact with
pigs, usually in the two weeks before the onset of illness, suggesting that there
was direct viral transmission from pigs to humans and a short incubation period.
The main presenting features were fever, headache, dizziness, and vomiting. Fifty
two patients (55 percent) had a reduced level of consciousness and prominent
brain-stem dysfunction. Distinctive clinical signs included segmental myoclonus,
areflexia and hypotonia, hypertension, and tachycardia and thus suggest the
involvement of the brain stem and the upper cervical spinal cord. The initial
cerebrospinal fluid findings were abnormal in 75 percent of patients. Antibodies
against Hendra virus were detected in serum or cerebrospinal fluid in 76 percent
of 83 patients tested. Thirty patients (32 percent) died after rapid
deterioration in their condition. An abnormal doll's-eye reflex and tachycardia
were factors associated with a poor prognosis. Death was probably due to severe
brain-stem involvement. Neurologic relapse occurred after initially mild disease
in three patients. Fifty patients (53 percent) recovered fully, and 14 (15
percent) had persistent neurologic deficits. CONCLUSIONS: Nipah virus causes a
severe, rapidly progressive encephalitis with a high mortality rate and features
that suggest involvement of the brain stem. The infection is associated with
recent contact with pigs.
PMID- 10781619
TI - An outbreak of febrile gastroenteritis associated with corn contaminated by
Listeria monocytogenes.
AB - BACKGROUND: On May 21, 1997, numerous cases of febrile gastrointestinal illness
were reported among the students and staff of two primary schools in northern
Italy, all of whom had eaten at cafeterias served by the same caterer. METHODS:
We interviewed people who ate at the cafeterias about symptoms and foods consumed
on May 20. There were no samples of foods left at the cafeterias, but we tested
routine samples taken on May 20 by the caterer and environmental specimens at the
catering plant. The hospitalized patients were tested for common enteropathogens
and toxins. RESULTS: Of the 2189 persons interviewed (82 percent of those
exposed), 1566 (72 percent) reported symptoms; of these, 292 (19 percent) were
hospitalized. Among samples obtained from hospitalized patients, all but two of
the stool specimens and all blood specimens were negative for common
enteropathogens. Listeria monocytogenes was isolated from one blood specimen and
from 123 of the 141 stool specimens. Consumption of a cold salad of corn and tuna
was associated with the development of symptoms (relative risk, 6.19; 95 percent
confidence interval, 4.81 to 7.98; P<0.001). L. monocytogenes was isolated from
the caterer's sample of the salad and from environmental specimens collected from
the catering plant. All listeria isolates were serotype 4b and were found to be
identical on DNA analysis. Experimental contamination of sterile samples of the
implicated foods showed that L. monocytogenes grew on corn when kept for at least
10 hours at 25 degrees C. CONCLUSIONS: Food-borne infection with L. monocytogenes
can cause febrile illness with gastroenteritis in immunocompetent persons.
PMID- 10781620
TI - Ceftriaxone-resistant salmonella infection acquired by a child from cattle.
AB - BACKGROUND: The emergence of resistance to antimicrobial agents within the
salmonellae is a worldwide problem that has been associated with the use of
antibiotics in livestock. Resistance to ceftriaxone and the fluoroquinolones,
which are used to treat invasive salmonella infections, is rare in the United
States. We analyzed the molecular characteristics of a ceftriaxone-resistant
strain of Salmonella enterica serotype typhimurium isolated from a 12-year-old
boy with fever, abdominal pain, and diarrhea. METHODS: We used pulsed-field gel
electrophoresis and analysis of plasmids and beta-lactamases to compare the
ceftriaxone-resistant S. enterica serotype typhimurium from the child with four
isolates of this strain obtained from cattle during a local outbreak of
salmonellosis. RESULTS: The ceftriaxone-resistant isolate from the child was
indistinguishable from one of the isolates from cattle, which was also resistant
to ceftriaxone. Both ceftriaxone-resistant isolates were resistant to 13
antimicrobial agents; all but one of the resistance determinants were on a
conjugative plasmid of 160 kb that encoded the functional group 1 beta-lactamase
CMY-2. Both ceftriaxone-resistant isolates were closely related to the three
other salmonella isolates obtained from cattle, all of which were susceptible to
ceftriaxone. CONCLUSIONS: This study provides additional evidence that antibiotic
resistant strains of salmonella in the United States evolve primarily in
livestock. Resistance to ceftriaxone, the drug of choice for invasive salmonella
disease, is a public health concern, especially with respect to children, since
fluoroquinolones, which can also be used to treat this disease, are not approved
for use in children.
PMID- 10781621
TI - Enteritis necroticans (pigbel) in a diabetic child.
AB - BACKGROUND AND METHODS: Enteritis necroticans (pigbel), an often fatal illness
characterized by hemorrhagic, inflammatory, or ischemic necrosis of the jejunum,
occurs in developing countries but is rare in developed countries, where its
occurrence is confined to adults with chronic illnesses. The causative organism
of enteritis necroticans is Clostridium perfringens type C, an anaerobic gram
positive bacillus. In December 1998, enteritis necroticans developed in a 12-year
old boy with poorly controlled diabetes mellitus after he consumed pig intestines
(chitterlings). He presented with hematemesis, abdominal distention, and severe
diabetic ketoacidosis with hypotension. At laparotomy, extensive jejunal necrosis
required bowel resection, jejunostomy, and ileostomy. Samples were obtained for
histopathological examination. Polymerase-chain-reaction (PCR) assay was
performed on paraffin-embedded bowel tissue with primers specific for the cpa and
cpb genes, which code for the alpha and beta toxins produced by C. perfringens.
RESULTS: Histologic examination of resected bowel tissue showed extensive mucosal
necrosis, the formation of pseudomembrane, pneumatosis, and areas of epithelial
regeneration that alternated with necrotic segments--findings consistent with a
diagnosis of enteritis necroticans. Gram's staining showed large gram-positive
bacilli whose features were consistent with those of clostridium species. Through
PCR amplification, we detected products of the cpa and cpb genes, which indicated
the presence of C. perfringens type C. Assay of ileal tissue obtained during
surgery to restore the continuity of the patient's bowel was negative for C.
perfringens. CONCLUSIONS: The preparation or consumption of chitterlings by
diabetic patients and other chronically ill persons can result in potentially
life-threatening infectious complications.
PMID- 10781622
TI - Images in clinical medicine. African trypanosomiasis in Australia.
PMID- 10781623
TI - Myelofibrosis with myeloid metaplasia.
PMID- 10781624
TI - Evaluation of abnormal liver-enzyme results in asymptomatic patients.
PMID- 10781625
TI - Case records of the Massachusetts General Hospital. Weekly clinicopathological
exercises. Case 13-2000. A 26-year-old woman with bouts of abdominal pain,
vomiting, and diarrhea.
PMID- 10781626
TI - Emerging infections--another warning.
PMID- 10781627
TI - Telomeres, telomerase, and cancer.
PMID- 10781629
TI - Correction: A Randomized Study of the Prevention of Sudden Death in Patients with
Coronary Artery Disease.
PMID- 10781630
TI - Pioneer research in Britain into atherosclerosis and coronary heart disease--an
historical review.
PMID- 10781631
TI - Relative roles of mitochondrial and peroxisomal fatty acid oxidation in the
metabolism of chylomicron remnants in rats and mice as assessed by a stable
isotope breath test.
AB - We have developed a stable isotope breath test to trace physiological remnant
metabolism. Validity of the test depends on the injected lipid emulsion mimicking
chylomicron remnant (CR) clearance and on subsequent metabolism of the emulsion
cholesteryl ester (CE). Oxidation of CE fatty acids could involve both
mitochondrial and peroxisomal pathways. In the present studies various agents
were used to inhibit the binding of remnants, CE hydrolysis or mitochondrial
fatty acid oxidation. Treatment of mice with suramin or lactoferrin markedly
delayed the clearance and metabolism of remnants as shown by the significantly
lower enrichment of 13CO(2) in the breath when compared with untreated mice. In
hepatectomized rats injected with remnant-like emulsions, enrichment with 13CO(2)
was virtually abolished. Treatment of mice with chloroquine or rats with methyl
palmoxirate (an inhibitor of mitochondrial fatty acid oxidation) markedly
impaired the recovery of label in the breath. Compared with mice fasted
overnight, Intralipid by gavage decreased the breath enrichment with 13CO(2)
consistent with competition between endogenous CR and the injected emulsion
particles. These findings show that the breath test reliably measures the
metabolism of CR and that CE fatty acid is metabolised by mitochondrial pathways.
PMID- 10781632
TI - CD143 in the development of atherosclerosis.
AB - The expression of CD143 (angiotensin-I-converting enzyme, ACE) in cardiovascular
diseases may be an important determinant of local angiotensin and kinin
concentrations. Much of the experimental and clinical evidence suggests a crucial
role for Ang II in fibrogenesis and the development of atherosclerosis.
Therefore, we have studied the distribution of CD143 in atherosclerotic and non
atherosclerotic segments isolated from different parts of the human vascular
tree, including aorta and coronary, carotid, brachial, renal, iliac and femoral
arteries, and staged according to the AHA. Two hundred and thirty native and
formalin-fixed specimens of 80 patients were analysed by sensitive APAAP
technique using ten different monoclonal and polyclonal antibodies to human CD143
and several controls. In non-atherosclerotic segments or intimal thickening,
CD143 was found almost restricted to the endothelial cells of adventitial
arterioles and small muscular arteries. In contrast, a striking accumulation of
CD143 was detected in all early and advanced atherosclerotic lesions. This de
novo occurrence of CD143 within the intimal vascular wall was caused by spindle
shaped subendothelial cells with macrophagic/histocytic features, activated
macrophages and foam cells. In addition, advanced lesions of atherosclerosis
showed a marked neo-expression of CD143 in newly formed intimal microvessels.
Hypocellular fibrotic plaques depleted in microvessels and macrophages showed
only little CD143. The de-novo occurrence of CD143 was dependent on the stage of
atherosclerosis but not on its particular localisation within the vascular
system. This early and obligatory CD143 expression at an unusual vascular site
may contribute to unusual tissue levels of angiotensins as indicated by co
localisation of immunoreactive Ang II. Thus, it may be an important pathogenetic
step in the development of atherosclerosis and an established target for
pharmacological prevention.
PMID- 10781633
TI - Expression of intercellular adhesion molecules in human saphenous veins: effects
of inflammatory cytokines and neointima formation in culture.
AB - Atherosclerosis causes occlusions in as many as 50% of human saphenous vein
coronary artery bypass grafts. Monocyte infiltration is an early step in
saphenous vein-graft atherosclerosis, however, comparatively little is known of
its underlying mechanisms. As a first approach, we sought to define the
occurrence, location and regulation of leukocyte adhesion molecules in human
saphenous vein before and after surgical preparation for grafting, during
neointima formation in culture and on stimulation with inflammatory cytokines. We
compared the distribution of intercellular adhesion molecule (ICAM-1), vascular
cell adhesion molecule (VCAM-1) and platelet endothelial cell adhesion molecule
(PECAM-1 or CD-31) in endothelial cells and smooth muscle cells (SMCs), using
immunocytochemistry. ICAM-1 was expressed on endothelial cells before culture and
on both endothelial cells and medial or neointimal SMCs after culturing vein for
14 days in 30% foetal bovine serum or after culturing for 24 h with TNF-alpha.
Relative tissue levels of ICAM-1 measured by Western blotting were significantly
elevated by culturing freshly-isolated (0.02+/-0.01 to 0.18+/-0.03) and
surgically-prepared (0.02+/-0.01 to 0.14+/-0.03; n=6) veins or following TNF
alpha treatment of surgically-prepared veins (0.04+/-0.01 to 0.32+/-0.11, n=7).
VCAM-1 was undetectable before or after culturing but was strongly upregulated on
endothelial cells by incubation with the cytokines TNF-alpha, IL-1alpha or
interferon-gamma. PECAM-1 was expressed constitutively on endothelial cells. We
conclude that human saphenous vein expresses several adhesion molecules capable
of mediating monocyte migration. The increased expression of ICAM-1 in SMC after
culturing or cytokine treatment and of VCAM-1 in endothelial cells suggests that
interactions with beta1 and beta2 integrins are important pathways for stimulated
monocyte ingress into human saphenous vein grafts.
PMID- 10781634
TI - Neural reorganisation in porcine vein grafts: a potential role for endothelin-1.
AB - Vein grafts are associated with adventitial remodelling which may influence
innervation of the graft. Since there is also evidence that endothelin-1 (ET-1)
plays a role in the adventitial remodelling process, we investigated neural
distribution in porcine vein grafts 1 and 6 months after implantation, as well as
the localisation of immunoreactive ET-1 and its receptors in the same tissues.
Saphenous vein-carotid artery interposition grafting was performed in Landrace
pigs. One and 6 months after surgery, vein grafts and ungrafted saphenous veins
were excised; neural tissue and ET-1 were identified by immunocytochemistry and
ET receptors were identified using in vitro autoradiography. In ungrafted
saphenous veins, abundant perivascular nerves were located in the outer region of
the media with only a few paravascular nerves in the adventitia. In vein grafts
at 1 month after implantation, there was almost complete depletion of
perivascular nerves in the media. In contrast, in the neoadventitia, there was an
emphatic appearance of large paravascular nerve bundles and a marked increase in
small paravascular nerves. These changes were more pronounced at 6 months after
surgery, although the principal changes had occurred within 1 month.
Immunoreactive ET-1 (index of ET-1 content) was associated with paravascular
nerve bundles, appearing as a dark, dense ring at the perineurium. Furthermore,
within the nerve bundles, positive ET-1 immunoreactivity was associated with
positive alpha-actin staining, indicating that ET-1 is associated with (neural)
microvessels. Also, dense 125I-labelled BQ3020 (ET(B)-selective) binding to nerve
bundles was observed, indicating the presence of ET(B) receptor subtypes. ET(A)
receptor subtypes were not detected in neural tissue. These data demonstrate
neural reorganisation in vein grafts and indicate that ET-1 content and binding
may play a role in this process. The functional consequences of these changes on
neointima formation, a major cause of vein graft failure, remain to be
determined.
PMID- 10781635
TI - New model of atherosclerosis in insulin resistant sand rats: hypercholesterolemia
combined with D2 vitamin.
AB - To overcome the sand rats' resistance to cholesterol induced atherosclerosis,
animals were given D2 vitamin at 2000 IU/rat per day associated with cholesterol
enriched diet for 45 days, following 45 days of high cholesterol diet alone. At
days 0, 45 and 90, plasma parameters, aortic and heart morphology were examined.
Other animals receiving a high cholesterol diet alone were used as a control
group. Results showed at day 45 severe hypercholesterolemia, elevated plasma LDL
and VLDL-cholesterol, oxidized LDL and calcium levels, a rise of lecithin
cholesterol acyl transferase activity and moderate hyperinsulinemia. Lesions were
characterized by widening of the first interlamellar spaces in the aorta,
fibrosis of coronary arterial wall and recent foci of myocardial fibrosis. At day
90, plasma calcium level decreased and oxidized LDL were more enhanced. Insulin
resistance development was associated with glucose intolerance and
hyperinsulinemia. The D2 vitamin administration induced advanced atherosclerotic
lesions in arterial wall, represented by the rupture of elastic lamellae, smooth
muscle cell proliferation and lipid-calcic core. The complicated plaque
frequently evolved into ulcerations. The ischaemic effects were represented by
acute myocardial infarction. D2 vitamin is an atherogenic agent which, when
associated with hypercholesterolemia, allows the development of advanced
atherosclerotic lesions in sand rat which resembles human plaque.
PMID- 10781636
TI - Interaction between human monocytes and vascular smooth muscle cells induces
vascular endothelial growth factor expression.
AB - The objective of this study was to investigate whether synthesis of vascular
endothelial growth factor (VEGF), a major mitogen for vascular endothelial cells,
was induced by a cell-to-cell interaction between monocytes and vascular smooth
muscle cells (VSMCs). Human VSMCs and THP-1 cells (human monocytoid cell) were
cocultured. VEGF levels in the coculture medium were determined by enzyme-linked
immunosorbent assay. Northern blot analysis of VEGF mRNA was performed using a
specific cDNA probe. Immunohistochemistry was performed to determine which types
of cell produce VEGF. Adding THP-1 cells to VSMCs for 24 h increased VEGF levels
of the culture media, 8- and 10-fold relative to those of THP-1 cells and VSMCs
alone, respectively. Northern blot analysis showed that VEGF mRNA expression was
induced in the cocultured cells and peaked after 12 h. Immunohistochemistry
disclosed that both types of cell in the coculture produced VEGF. Separate
coculture experiments revealed that both direct contact and a soluble factor(s)
contributed to VEGF production. Neutralizing anti-interleukin (IL)-6 antibody
inhibited VEGF production by the coculture of THP-1 cells and VSMCs. A cell-to
cell interaction between monocytes and VSMCs induced VEGF synthesis in both types
of cell. An IL-6 mediated mechanism is at least partially involved in VEGF
production by the cocultures. Local VEGF production induced by a monocyte-VSMC
interaction may play an important role in atherosclerosis and vascular
remodeling.
PMID- 10781637
TI - Accelerated atherosclerosis in C57Bl/6 mice transplanted with ApoE-deficient bone
marrow.
AB - Apolipoprotein E (apoE), a high affinity ligand for lipoprotein receptors, is
synthesized by the liver and extrahepatic tissues, including cells of the
monocyte/macrophage cell lineage. The role of monocyte/macrophage-derived apoE in
atherogenesis was assessed by transplantation of apoE-deficient (apoE-/-) bone
marrow into normolipidemic C57Bl/6 mice. No significant effect could be
demonstrated on serum apoE levels in C57Bl/6 mice, transplanted with apoE
deficient bone marrow compared with control transplanted mice. Furthermore, no
consistent effect on serum cholesteryl esters and triglyceride concentrations
could be demonstrated on either a standard chow diet or a high cholesterol diet.
Quantitative analysis of atherosclerosis in mice transplanted with apoE-deficient
bone marrow, after two months on a high cholesterol diet, revealed a 4-fold
increase in the atherosclerotic lesion area as compared to animals transplanted
with apoE+/+ bone marrow. Analysis of the ability of apoE-deficient macrophages
to release cholesterol after loading with acetylated LDL revealed that the
release of cholesterol from apoE-deficient macrophages was impaired as compared
to wild-type macrophages in the absence and the presence of specific cholesterol
acceptors. In conclusion, apoE production by macrophages retards the formation of
atherosclerotic plaques, possibly by mediating cholesterol efflux. We anticipate
that pharmacological approaches to increase apoE synthesis and/or secretion by
macrophages might be beneficial for the treatment of atherosclerosis.
PMID- 10781638
TI - Preconditioning limits myocardial infarct size in hypercholesterolemic rabbits.
AB - BACKGROUND: Hypercholesterolemia predisposes to coronary artery disease and
causes endothelial dysfunction; some reports suggest that endothelial derived
substances are involved in ischemic preconditioning. OBJECTIVE: Our aim was to
examine the possibility that preconditioning maybe attenuated in a clinically
relevant animal model of hypercholesterolemia with atherosclerosis. METHODS: Male
rabbits were fed with cholesterol enriched diet and then divided into two groups
(A and B) without and with preconditioning, respectively. A second series of
rabbits fed a normal diet were similarly divided into two groups (C and D)
without and with preconditioning, respectively. All the animals were subjected to
30 min ischemia and 180 min reperfusion. Blood samples were collected for
cholesterol assessment; arterial and heart samples were harvested at the end for
histopathological examination. Infarct (I) and risk areas (R) were delineated
with Zn-Cd particles and TTC staining. RESULTS: Cholesterol in groups A and B was
58.3+/-8.7 mg% at baseline and 1402+/-125 mg% at 8 weeks (P<0.0001) and in groups
C and D 57.5+/-5.8 mg% before the surgical procedure. I/R% was 39. 3+/-6.3% in
group A, 16.7+/-3.9% in B (P<0.01), 41.4+/-7.5% in C and 10.8+/-3.3% in D
(P<0.01). CONCLUSION: We conclude that preconditioning is unlikely to be
attenuated by hypercholesterolemia.
PMID- 10781639
TI - Macrophage-released proteoglycans enhance LDL aggregation: studies in aorta from
apolipoprotein E-deficient mice.
AB - Aggregated low-density lipoprotein (LDL) was shown to be present in the
atherosclerotic lesion, but the mechanism responsible for its formation in vivo
is not known yet. To find out whether LDL aggregation occurs in the arterial wall
during atherogenesis, LDLs were extracted from the aortas of apolipoprotein E
deficient (E(0)) mice during their aging (and the development of
atherosclerosis), and were analyzed for their aggregation states, in comparison
to LDLs isolated from aortas of control mice. LDL isolated from aortas of E(0)
mice was already aggregated at 1 month of age and its aggregation state
substantially increased with age, with 3-fold elevation at 6 months of age
compared to younger, 1-month-old, mice. Only minimal aggregation could be
detected in LDL derived from control mice. Electron microscopy examination
revealed that LDL particles from aortas of the E(0) mice were heterogeneous in
their size, ranging between 20 and 300 nm. The mouse aortic LDL contained
proteoglycans (PGs) and their content increased with the age of the mice, with
about 2-fold higher levels than those found in LDLs derived from aortas of
control mice. Macrophage-released PGs were previously demonstrated to enhance LDL
aggregation in vitro. However, their involvement in LDL aggregation in vivo has
not been studied yet. Thus, we next studied the effect of arterial macrophage
released PGs on the susceptibility of plasma LDL to aggregation by Bacillus
cereus sphingomyelinase (SMase). Foam cell macrophages were isolated from aortas
of the atherosclerotic E(0) mice at 6 months of age and were found to be loaded
with cholesterol and to contain oxidized lipids. To analyze the effect of
macrophage-released PGs on LDL aggregation, PGs were prelabeled by cell
incubation with [35S]sulfate, followed by incubation of macrophage-released PGs
with E(0) mouse plasma LDL (200 microg protein/ml) for 1 h at 37 degrees C.
[35S]Sulfated PGs were found to be LDL-associated and the susceptibility of PG
associated LDL to aggregation by SMase was increased by up to 45% in comparison
to control LDL. Similar results demonstrating the involvement of PGs in LDL
aggregation were obtained upon incubation of LDL with increasing concentrations
of PGs that were isolated from the entire aorta of E(o) mice (rather than the
isolated macrophages). The stimulatory effect of macrophage-released PGs on LDL
aggregation was markedly reduced when the PGs were pretreated with the
glycosaminoglycan-hydrolyzing enzymes, chondroitinase ABC or chondroitinase AC,
and to a much lesser extent with heparinase. We thus conclude that macrophage
released chondroitin sulfate PG can contribute to the formation of atherogenic
aggregated LDL in the arterial wall.
PMID- 10781640
TI - Effects of combination therapy with estrogen plus simvastatin on lipoprotein
metabolism in postmenopausal women with type IIa hypercholesterolemia.
AB - We investigated the effects of estrogen and simvastatin, administered both alone
and in combination, on the plasma lipid levels and lipoprotein-related enzymes in
45 postmenopausal women with type IIa hypercholesterolemia. They received 0.625
mg conjugated equine estrogen (n=15), 5 mg simvastatin (n=15), or the combination
(n=15) daily for 3 months. We measured the concentrations of cholesterol and
triglyceride in the plasma, and in the very low-density lipoprotein (VLDL),
intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL)1
(1.019T (m allele)
mutation in the plasma PAF-AH gene, which results in a Val(279)-->Phe
substitution in the mature protein, leads to a loss of catalytic activity. To
elucidate the relationships among PAF-AH enzyme activity, genotype, age, and
atherosclerosis, we assayed these parameters in a large Japanese population
(n=3932) that consisted of three groups; a control group (healthy individuals;
n=1684), a risk-factor group (individuals having at least one conventional risk
factor for atherosclerosis; n=1398), and a diseased group (patients who had
suffered a myocardial infarction or stroke; n=850). We observed a significantly
increased frequency of the m allele in the diseased group as compared with the
control or risk-factor groups. Plasma PAF-AH activity increased significantly
with age in women in the control group with the MM and Mm genotypes, and in men
in the control group with the MM genotype, but not in men with the Mm genotype.
In both the risk-factor and diseased groups, however, no correlation was observed
between plasma PAF-AH activity and age in subjects with either genotype. These
results suggest that in individuals with the MM genotype, plasma PAF-AH activity
may be increased in response to stresses induced by PAF and/or oxidized
phospholipids that might accumulate with age, but that this response is not
evident or reduced in healthy individuals with the m allele, or in subjects with
atherosclerotic disease, or having risk factors. Together with our previous
findings, the G(994)-->T mutation in the PAF-AH gene may be one of the genetic
determinants for atherosclerotic disease in the Japanese population.
PMID- 10781654
TI - Alpha-tocopherol supplementation decreases the oxidative susceptibility of LDL in
renal failure patients on dialysis therapy.
AB - Atherosclerotic cardiovascular disease is the leading cause of death in patients
with end stage renal disease (ESRD) who have undergone dialysis treatment. The
oxidation of low density lipoprotein (LDL) appears to be a crucial step in the
pathogenesis of atherosclerosis. The increased oxidative stress and attendant
increased oxidizability of lipoproteins, such as LDL could contribute to the
accelerated atherosclerosis in dialysis patients. Since alpha-tocopherol (AT) is
the major antioxidant in LDL, the aim of the present study was to test the
effectiveness of RRR-AT supplementation (800 I.U. per day) for 12 weeks on the
susceptibility of LDL to oxidation. The study subjects comprised patients with
chronic renal failure on hemodialysis (HD), peritoneal dialysis (PD), and age and
sex matched controls (C). Plasma fatty acids, lipoproteins and AT levels were
measured in these subjects before and after supplementation. Also, LDL AT and
oxidizability was studied. LDL was isolated by ultracentrifugation at baseline
and after 12 weeks of supplementation, and subjected to a 5-h time course of
copper catalyzed oxidation. Oxidation was measured by the formation of conjugated
dienes (CD) and lipid peroxides (LP). Supplementation with AT did not alter the
plasma lipid or lipoprotein profile of these subjects. Plasma lipid-standardized
AT and LDL AT concentrations were not different among the groups at baseline. AT
supplementation significantly increased plasma lipid-standardized AT (C=150%,
HD=149%, PD=217%, P<0.001) and LDL AT concentrations (C=94%, HD=94%, PD=135%,
P<0.003). AT enrichment of LDL resulted in a significant prolongation in
conjugated diene lag phase in all groups (C=34%, HD=21%, PD=54%, P<0.02). Lipid
peroxide lag phase was also increased significantly in C (27%,) and PD (40%)
groups after AT supplementation (P<0.01). There was a significant positive
correlation between plasma lipid standardized AT and lag phase (r=0. 54,
P=0.0003). Overall, AT decreased the susceptibility of LDL to oxidation in
patients with chronic renal failure but the benefit appears to be greater in
patients on PD. Therefore, AT supplementation may also provide a measure of
protection against CAD in patients with chronic renal failure on dialysis
therapy.
PMID- 10781655
TI - What pathological components indicate carotid atheroma activity and can these be
identified reliably using ultrasound?
AB - OBJECTIVE: The aim of this project was to determine whether histological features
of 'active' plaque as described in the coronary circulation following acute
myocardial infarction were similar in the carotid circulation, and whether these
factors could be detected ultrasonically. METHOD: Endarterectomy specimens were
prospectively collected, and examined histologically and assessed by two
observers for ulceration, inflammation, size of necrotic core, thickness of
fibrous cap, haemorrhage and luminal thrombosis. Ultrasound of the plaque
obtained preoperatively was similarly coded (blind to pathology) and compared
with the pathology. RESULTS: In 42 endarterectomy specimens, there was a highly
significant relationship between a thin fibrous cap and a large necrotic core
(P<0.002), irregular plaque contour (P<0.05) and ulceration (P<0.01) and between
a large necrotic core (P<0.002) and ulceration and inflammation (P<0.05).
Increasing amounts of necrosis were associated with more surface thrombosis
(P<0.02). Ultrasound detected the thickness of the fibrous cap and 'any necrosis
or haemorrhage' with some reliability (kappas are 0.53 and 0.5, respectively),
but not ulceration, necrosis or haemorrhage on their own. CONCLUSION: Features
corresponding to active atheromatous plaque are similar in the carotid and
coronary arteries, and some of these, namely lucent areas in the plaque
(corresponding to necrosis or haemorrhage) and the thickness of the fibrous cap,
can be determined reliably with ultrasound.
PMID- 10781656
TI - Doppler monitoring of the vascular resistance in the lower limbs during
dipyridamole test in preparation for myocardial tomoscintigraphy.
AB - OBJECTIVE: the aim of this work was to quantify the intensity of the vasodilation
induced by dipyridamole used to simulate a stress test during a myocardial
tomoscintigraphy. METHODS: Doppler measurements of the femoral artery and the
thoracic aorta were made on 26 patients (11 men, 15 women), using transducers
attached to the skin, measurements being performed every 2 min during the 10 min
of the stress test. The following parameters were measured: (a) the vascular
resistance index of the lower limbs defined as R(fa)=D/S with S and D,
respectively, the maximum amplitude of the systolic wave and the maximum
amplitude of the diastolic reflux measured on the Doppler femoral spectrogram;
(b) the aortic and femoral blood flows obtained from the mean velocity on the
Doppler spectrogram. RESULTS: 14 of the 26 patients (54%) showed a significant
vasodilation (i.e. a decrease of R(fa) of more than 10%). Eighty-seven percent of
the patients with a positive myocardial scintigraphy showed a vasodilation. Sixty
six percent of patients who had prior vasodilator treatment showed no
vasodilation. A slight decrease in blood pressure was observed for vasodilated
patients but also for non-vasodilated patients. The aortic flow increased
slightly for all patients. CONCLUSIONS: Doppler monitoring of femoral vascular
resistance is a useful method for quantifying the dipyridamole-induced
vasodilation, and hence the stress level upon which the diagnostic efficiency of
myocardial scintigraphy is depending. Our study demonstrates that testing with
dipyridamole was inconclusive in 66% of patients who had already vasodilator
treatment.
PMID- 10781657
TI - Improved characterisation of focal liver tumours: dynamic power Doppler imaging
using NC100100 echo-enhancer.
AB - OBJECTIVE: To assess the vascularisation of focal hepatic tumours using NC100100,
enhanced power Doppler imaging. METHODS: Twenty-two patients with focal liver
tumours (12 metastases and ten hemangiomas) were studied. Using standardised
settings, power Doppler imaging with ATL HDI3000 was performed before and after
intravenous administration of NC100100 contrast agent. The video-recorded
examinations were digitised for off-line analysis on a personal computer. Regions
of interest were defined over the entire tumour and a neighbouring area of the
normal liver parenchyma. The temporal changes of the mean power Doppler signal
intensity (PDSI) was quantified to provide contrast agent wash-in (PDSI-time)
curves for the initial 40 s. RESULTS: Liver metastases were characterised by a
rapid increase in PDSI, while the PDSI-time curves within hemangiomas were flat.
The PDSI within the tumour increased significantly in ten subjects with liver
metastases and only one subject with hemangioma. An enhanced rim around
hemangiomas was seen in four subjects. There was no clear relationship between
the contrast agent dose and the peak PDSI within metastases. CONCLUSIONS: Power
Doppler imaging with NC100100 contrast agent enhances tumour visualisation and
may aid differential diagnosis of focal liver lesions.
PMID- 10781658
TI - Evaluation of left ventricular systolic function by 3D echocardiography: a
comparative study with X-ray angiography and radionuclide angiography.
AB - OBJECTIVE: the aim of this study was to evaluate left ventricular systolic
function by 3D ultrasound as compared to with radionuclide and X-ray
angiographies. METHODS: one hundred and four patients were examinated by 3D
ultrasound (3D-US) but only 72 examinations were successful. Thirty patients were
investigated by 3D-US, M-mode US or bidimensional (2D) US, and X-ray angiography
(group I) and 42 patients were investigated by 3D-US, M-mode, or 2D, and
radionuclide angiography (group II). RESULTS: the correlation between ejection
fraction (EF) evaluated by 3D-US and reference methods was found to be good and
similar for the two groups (r=0.75; P<10(-4) for group I and r=0.76; P<10(-4) for
group II). The correlation between EF calculated by conventional 2D-US and by
reference methods was lower (r=0.60; P=0.04 for group I and r=0.54; P=0.001 for
group II). The correlation between EF evaluated by 3D- and 2D-US was modest (r=0.
55; P=0.001 for the whole group). The correlation between 3D-US left ventricle
end-diastolic volume (EDV) and end-systolic volume (ESV) and those evaluated by X
ray angiography was also modest (r=0.33; NS for EDV and r=0.60; P<10(-4) for
ESV). The correlations between EDV and ESV in 3D-US, and those evaluated from
radionuclide angiography were fairly good and in the same range (r=0.76; P<10(-4)
and r=0.87; P<10(-4)). CONCLUSION: the 3D-US system using a rotating probe in an
apical view is valuable for evaluation of left ventricular systolic function.
PMID- 10781659
TI - Power Doppler sonography in the diagnosis of Graves' disease.
AB - In addition to color and pulsed Doppler sonography findings, we aimed to describe
power Doppler sonography findings in Graves' disease in this study. Twenty-three
patients with Graves' disease were imaged with gray-scale, color and power
Doppler sonography. Twenty normal volunteers were examined by the same equipment
and the same technique as a control group. A subjective grading system was used
to categorize the vascularization in pulsed Doppler sonography images from normal
to markedly increased vascularization. Power Doppler sonography exhibited diffuse
hypervascularity in the thyroid gland in all patients. The flow was covering
about all the parenchyma. Four patients showed mild, 12 patients moderate and
seven patients marked vascularity. The intensity of power Doppler flow pattern
was not correlated with the severity of the disease. This study demonstrated that
power Doppler sonography is a convenient, time saving, inexpensive and
noninvasive method as compared with isotope scan and some other laboratory tests
for confirmation of Graves' disease.
PMID- 10781660
TI - Ultrasonography of Zenker's diverticulum: special reference to differential
diagnosis from thyroid nodules.
AB - There have been only two case reports so far in literature on ultrasonographic
features of Zenker's diverticulum. We report a case of Zenker's diverticulum and
discuss the ultrasonographic images in comparison with those of thyroid nodules.
Awareness of changeable internal echoes and not mistaking strong echogenic foci
caused by air for calcification were most important for making the differential
diagnosis of Zenker's diverticulum from thyroid nodules.
PMID- 10781661
TI - Comparison of the efficacy of two air-based contrast agents in dogs.
AB - OBJECTIVE: The aim of this study was to evaluate the differences of the in vivo
efficacies of Levovist(SH U 508 A) and Albunex, air-based contrast agents (CAs)
with different shell materials, by direct comparison. METHODS: SH U 508 A, 300
mg/ml, and Albunex were injected intravenously at doses of 0.1 and 0.15 ml/kg,
respectively, into the same dogs (n=6). Contrast enhancement in the left
ventricle was evaluated visually and by off-line measurement of brightness.
RESULTS: Both CAs yielded good peak contrast, while the duration of contrast
enhancement with SH U 508 A was seven times that with Albunex. With Albunex,
reduction of contrast enhancement at end-systole and in the late phase of
diastole during one heartbeat was observed, and a positive correlation was
observed between contrast enhancement and heart rate. Contrast enhancement was
nearly constant during one heartbeat with SH U 508 A. CONCLUSION: SH U 508 A
yielded consistent and longer contrast enhancement in the left ventricle than
Albunex under the same conditions.
PMID- 10781662
TI - The three-dimensional ultrasound evaluation of the rotator cuff--an experimental
study.
AB - OBJECTIVE: An accurate sonographic diagnosis of rotator cuff lesions
significantly depends on image quality and on the experience of the operator. The
present study was performed to determine whether the use of three dimensional
(3D) sonography further increases the diagnostic yield of ultrasound. METHODS: In
an experimental study 22 artificial rotator cuff lesions (seven full thickness
and 15 partial thickness tears) of cadaveric shoulder joints were evaluated by
ultrasound with two and three dimensional imaging in a water basin. RESULTS: With
3D ultrasound, rotator cuff lesions were more often correctly diagnosed
(sensitivity of 77%) than with conventional 2D sonography (sensitivity of 64%).
Specificity was 85 and 69%, respectively. In partial thickness tears in
particular, 3D imaging was the superior method reaching a sensitivity and
specificity of 73 and 77%, respectively, compared to 53 and 61%, respectively,
with 2D ultrasound. With 2D and 3D ultrasound eight and 11 out of 13 tendons,
respectively, were correctly diagnosed as intact confirmed by histopathological
examination. CONCLUSION: Although the results of an experimental study may not
reflect the clinical situation, 3D ultrasound appears to facilitate diagnosis of
partial thickness rotator cuff tears.
PMID- 10781663
TI - Ultrasonic parameters and relationship between compressive strength,
microstructure of gall bladder stones.
AB - Patients with symptomatic stones are at a great risk for complications and these
complications are a major cause of morbidity. The gall bladder stones may have a
complex structure and variable composition. In the present investigation stones
have been grouped into three categories namely cholesterol, bilirubinate and
mixed, and a correlation between the surface structure, ultrasonic parameters and
compressive strength is estimated. A double-probe through-transmission technique
was used for the ultrasonic parameters study, a universal testing instrument for
hardness and a scanning electron microscope (SEM) for microstructure study. Gall
bladder stones of mixed type with higher ultrasonic velocity, less attenuation
and higher crushing strength were found to be more difficult to break in
comparison to other types of stones. SEM of mixed type stones showed rough
surface as compared to bilirubinate and cholesterol stones. The results obtained
as well as the relationship might be useful in the design of a focussed
ultrasonic 0lithotripter.
PMID- 10781665
TI - EFSUMB reviews of recent safety literature. European committee for medical
ultrasound safety (ECMUS)
PMID- 10781664
TI - Hand gripping effect on cerebral blood flow in normal subjects.
AB - The changes of regional cerebral blood flow (rCBF) related to metabolic demand
depend on both integrity of neuronal function and vascular blood flow. Therefore,
we assessed the motor stimulus to blood flow velocity (BFv) changes of bilateral
middle cerebral arteries (MCA) by transcranial Doppler (TCD) sonography in normal
subjects. Eighteen subjects (nine female, aged 48.0+/-3.8 years; nine male, aged
54.4+/-4.8 years) were investigated. Bilateral TCD sonography from both MCA were
monitored during ten cycles of 20 s when subjects were performing bilateral hand
gripping with a frequency of one per second, and subsequently 20 s when they were
rest. Bilateral hand gripping showed a significant BFv increase on both MCA
(P<0.001). These values were (19+/-2)% on both sides. There was no significant
side to side difference between the absolute BFv values both at rest and during
bilateral hand gripping. Additionally, the absolute BFvs and BFv increases were
not significantly different between male and female subjects. This study was
based on a small sample size, and the method requires the subject cooperation.
Our results suggest that bilateral hand gripping may affect blood flow in both
MCA without side to side differences. Finally, our suggestion is that test might
be useful to assess the neurovascular integrity.
PMID- 10781666
TI - Changes in rat brain energetic metabolism after exposure to anandamide or
Delta(9)-tetrahydrocannabinol.
AB - The objective of this study was to investigate whether single and repeated
administration of the cannabinoids anandamide or Delta(9)-tetrahydrocannabinol
affected brain energetic metabolism. Single administration of either anandamide
(20 mg/kg) or Delta(9)-tetrahydrocannabinol (10 mg/kg) in rats induced a
behaviour typical with cannabinoids. An increase in both brain mitochondria
oxidative phosphorylation and cerebral lipoperoxidation was shown ex vivo. The
cannabinoid CB(1) receptor-specific antagonist, N-piperidino-5-(4-chlorophenyl)-1
(2, 4-dichlorophenyl)-4-methylpyrazole-3-carboxamide (SR141716A; 3 mg/kg),
reversed the anandamide-induced metabolic effects. Prolonged exposure to
anandamide (20 mg/kg, 16 days) induced behavioural tolerance and the
disappearance of the increased mitochondria oxygen uptake and lipoperoxidation.
Repeated Delta(9)-tetrahydrocannabinol injection (10 mg/kg, twice daily, 4.5
days) reduced brain metabolism and uncoupled respiration from oxidative
phosphorylation. The present findings showed that both anandamide and Delta(9)
tetrahydrocannabinol enhanced the energetic brain metabolism, probably via the
cannabinoid CB(1) receptor; the anandamide-tolerant brain of rats showed
tolerance to the drug for metabolic effects, while the brain of Delta(9)
tetrahydrocannabinol-tolerant rats showed metabolic signs of neuronal damage,
i.e. low energy production.
PMID- 10781667
TI - Evidence for the participation of the nitric oxide-cyclic GMP pathway in the
antinociceptive action of meloxicam in the formalin test.
AB - The involvement of the nitric oxide-cyclic GMP pathway in the antinociceptive
action of the cyclooxygenase-2 preferential inhibitor meloxicam was assessed in
the rat formalin test. Rats received local pretreatment with saline or meloxicam
and then 50 microl of dilute formalin (1%). Local administration of meloxicam
produced a dose-dependent antinociception in the second phase of the formalin
test. The antinociception produced by meloxicam was due to a local action as its
administration in the contralateral paw was ineffective. Local pretreatment of
the paws with saline or N(G)-D-nitro-arginine methyl ester (D-NAME) did not
affect the antinociception produced by meloxicam. However, N(G)-L-nitro-arginine
methyl ester (L-NAME, a NO synthesis inhibitor) or 1H-(1,2,4)-oxadiazolo(4,2
a)quinoxalin-1-one (ODQ, a soluble guanylyl cyclase inhibitor) blocked in a dose
dependent way the effect of meloxicam. It is concluded that the peripheral
antinociceptive effect of meloxicam involves a local NO-cyclic GMP pathway.
PMID- 10781668
TI - Melatonin reversal of lipopolysacharides-induced thermal and behavioral
hyperalgesia in mice.
AB - The perception of pain sensation (threshold), whether local or central, is
altered by inflammatory processes. Anti-inflammatory drugs block this by raising
the pain threshold and by reducing the inflammatory process. Melatonin is claimed
to have anti-inflammatory activity in animal models of acute and chronic
inflammation. However, it is not known whether melatonin can reverse the
hyperalgesia that is secondary to the inflammation. The present study aimed to
assess the modulatory effect of melatonin on lipopolysaccharides-induced
alteration of pain perception in mice. Central perception of pain was assessed
with the tail-flick and hot-plate methods and local hyperalgesia was assessed by
noting the animal's reactions such as paw licking and rearing after the
intraplantar injection of lipopolysaccharides (5 microg/paw). Local
administration (intraplantar) of lipopolysacharides induced hyperalgesia when
measured by both central effects and behavioral reactions. Melatonin (5 and 10
mg/kg), like dexamethasone (0.5 mg/kg), given 30 min prior to, and 4 and 8 h
after lipopolysaccharides (5 microg/paw) challenge attenuated central and
behavioural hyperalgesia. The attenuation of lipopolysaccharides-induced
hyperalgesia by melatonin was not reversed by naltrexone (4 mg/kg). In vitro
studies showed that melatonin, in concentrations ranging from 100 to 1000 nM,
suppressed tumor necrosis factor-alpha (TNF-alpha) without affecting the nitric
oxide (NO) release in lipopolysaccharides-activated murine peritoneal
macrophages. Taken together, the present results demonstrated that melatonin
reverses lipopolysaccharides-induced hyperalgesia.
PMID- 10781669
TI - Effect of acute treatment with YM992 on extracellular serotonin levels in the rat
frontal cortex.
AB - (S)-2-[[(7-fluoroindan-4-yl)oxy]methyl]morpholine monohydrochloride (YM992) is a
novel putative antidepressant exhibiting both selective serotonin (5
hydroxytryptamine, 5-HT) reuptake inhibition and 5-HT(2A) receptor antagonism. In
vivo microdialysis revealed that a single treatment with YM992 (3, 10, 30 mg/kg
i.p.) dose-dependently increased extracellular 5-HT levels in the rat frontal
cortex. Fluoxetine, citalopram and venlafaxine also produced significant
increases in 5-HT levels at doses of 10-30 mg/kg. However, the increase in 5-HT
levels induced by YM992 was significantly larger than increases elicited by these
three compounds at 30 mg/kg. The combined administration of R-(+)-alpha-(2, 3
dimethoxyphenyl)-1-[2-(4-fluorophenyl)ethyl]-4-piperidine-methanol (MDL100,907)
(a selective 5-HT(2A) receptor antagonist) and citalopram produced no additional
increase in 5-HT levels compared with citalopram treatment alone. YM992
moderately enhanced [3H]5-HT release from rat cerebral cortex synaptosomes using
different mechanisms than p-chloroamphetamine. In comparison, 10-microM
fluoxetine markedly induced 5-HT release in vitro, while citalopram and
venlafaxine had no noticeable effect on release. YM992 produces a more robust
increase of 5-HT levels acutely than other antidepressants in vivo and the effect
may be due to 5-HT releasing properties of the drug.
PMID- 10781670
TI - Effect of acute treatment with YM992 on extracellular norepinephrine levels in
the rat frontal cortex.
AB - The effects of acute treatment with (S)-2-[[(7-fluoroindan-4
yl)oxy]methyl]morpholine monohydrochloride (YM992), venlafaxine, fluoxetine and
citalopram on extracellular norepinephrine levels were examined in the rat
frontal cortex by in vivo microdialysis. YM992 (3, 10, 30 mg/kg, i.p.) dose
dependently increased extracellular norepinephrine levels (3-fold at 10 mg/kg, 5.
5-fold at 30 mg/kg). While venlafaxine and 30 mg/kg fluoxetine also produced
significant increases in norepinephrine levels, 30 mg/kg citalopram had no
effect. The combined administration of MDL100,907 (a selective 5-HT(2A) receptor
antagonist) and citalopram did significantly increase norepinephrine levels
compared with either saline or citalopram treatment. Therefore, a synergistic
effect due to 5-HT reuptake inhibition and 5-HT(2A) receptor antagonism of YM992
may partly contribute to the increase of extracellular norepinephrine levels.
YM992 enhances the neurotransmission of not only 5-HT system but also
norepinephrine, and as such may have a preclinical profile different from that of
a selective serotonin reuptake inhibitor.
PMID- 10781671
TI - Effects of MK-801 on clozapine-induced potentiation of excitatory synaptic
responses in the perforant path-dentate gyrus pathway in chronically prepared
rabbits.
AB - We previously found that the atypical antipsychotic drug, clozapine, when
intraperitoneally (i.p.) injected, long-lastingly potentiated excitatory synaptic
responses elicited in the dentate gyrus by single electrical stimulations to the
perforant path in chronically prepared rabbits, and called this phenomenon
'clozapine-induced potentiation'. In the present study, we likewise examined
whether clozapine-induced potentiation is caused by NMDA receptor-mediated
neurotransmission in the perforant path-dentate gyrus pathway of chronically
prepared rabbits. The non-competitive NMDA receptor antagonist - 5-methyl-10,11
dihydro-5H-dibenzo[a,d]cyclo-hepten-5,10-imino hydrogen maleate (MK-801; 1.0
mg/kg, i.p.) - completely prevented the potentiation of synaptic responses
induced by subsequent administration of 20 mg/kg clozapine, whereas the 0.5 mg/kg
dose had virtually no effect on the potentiation. These results suggest that the
effect of clozapine requires NMDA receptor activation.
PMID- 10781672
TI - Ventral subiculum administration of the somatostatin receptor agonist MK-678
increases dopamine levels in the nucleus accumbens.
AB - Somatostatin (or somatotropin-release inhibitory factor, SRIF) binding and in
situ hybridisation studies have indicated a high expression of receptor subtypes
throughout the rat brain and, in particular, in subregions of the hippocampus and
subiculum. In vitro, somatostatin and related peptides, including seglitide (MK
678), hyperpolarize subicular neurones of the burst firing type-a response, which
may have functional consequences for their output. One major projection from the
subiculum is to the nucleus accumbens. The functional consequence of somatostatin
receptor stimulation in the ventral subiculum has been assessed by measuring
extracellular levels of dopamine in the ipsilateral nucleus accumbens. In
anaesthetised rats, administration of seglitide (MK-678), a somatostatin analogue
with selectivity for the SRIF-1 receptor (comprising somatostatin sst2, sst3 and
sst5 subtypes) significantly increased extracellular levels of dopamine in the
ipsilateral nucleus accumbens shell. The result suggests that hyperpolarization
of subicular neurones by MK-678 may lead to activation of the subiculo-accumbens
projection system, and an associated increase in dopaminergic function.
PMID- 10781673
TI - Involvement of mast cells, sensory afferents and sympathetic mechanisms in paw
oedema induced by adenosine A(1) and A(2B/3) receptor agonists.
AB - Both the adenosine A(1) receptor agonist N(6)-cyclopentyladenosine and the
adenosine A(2B/3) receptor agonist N(6)-benzyl-5'-N-ethylcarboxamido adenosine
(N(6)-B-NECA) produce an acute paw oedema response following local s.c. injection
into the rat hindpaw. This study characterized aspects of the mechanisms by which
these responses occur by determining the effect of compound 48/80 (mast cell
depleting agent), capsaicin (sensory neurotoxin) and 6-hydroxydopamine
(sympathetic nervous system neurotoxin) on the paw oedema response produced by
these agents. Compound 48/80 markedly reduced the increase in paw volume produced
by both N(6)-cyclopentyladenosine and N(6)-B-NECA. Capsaicin significantly
reduced paw oedema induced by N(6)-cyclopentyladenosine but not N(6)-B-NECA. In
contrast, 6-hydroxydopamine reduced paw oedema induced by N(6)-B-NECA but not
N(6)-cyclopentyladenosine. These results indicate an involvement of mast cells in
paw oedema produced by both adenosine A(1) and A(2B/3) receptor agonists. For
N(6)-cyclopentyladenosine, this involvement may be a secondary involvement due to
activation of a neurogenic mechanism, but for N(6)-B-NECA, it may be a direct
effect on mast cells. The nature of the involvement of the sympathetic nervous
system in the action of N(6)-B-NECA is not entirely clear.
PMID- 10781674
TI - Antithrombotic and hemostatic capacity of factor Xa versus thrombin inhibitors in
models of venous and arteriovenous thrombosis.
AB - Thrombin plays a central role in venous and arterial thrombosis. We utilized two
different rabbit models of in vivo thrombosis to investigate the effect of
inhibitors of thrombin generation and thrombin activity. The agents tested were
specific inhibitors of factor Xa (fXa) [N2-[(phenylmethyl)sulfonyl]-D-arginyl-N
[(1S)-4-[(aminoiminomethyl++ +)a mino]-1-(2-thiazolylcarbonyl)butyl]-glycinamide
(C921-78)] and thrombin [D-phenylalanyl-N-[4-[(aminoiminomethyl)amino]-1
(chloroacetyl)but yl]-L-prolinamide (PPACK)], as well as drugs that affect both
thrombin and fXa, unfractionated and low molecular weight (enoxaparin) heparin.
The agents administered as constant intravenous infusion were evaluated for
antithrombotic efficacy in anesthetized rabbits. All four agents were capable of
dose dependent inhibition of thrombosis in venous and arteriovenous thrombosis
models. However, due to the more aggressive nature of thrombotic stimulation in
the arteriovenous shunt model, complete cessation of thrombus growth was not
achieved for any of the agents at the doses tested. Comparison between the agents
focused on the differences in extension of coagulation parameters (activated
partial thromboplastin time, prothrombin time, thrombin clotting time), changes
in hematological parameters, and extension of rabbit cuticle bleeding time at
doses required to produce maximum inhibition in the thrombosis models. In the
venous thrombosis model at the maximally effective dose, C921-78 had minimal
extension of ex vivo clotting parameters, while enoxaparin and unfractionated
heparin demonstrated a two to sevenfold increase in activated partial
thromboplastin times, and PPACK had a threefold extension of thrombin clotting
times. In addition, unlike the other three agents, which exhibited no significant
changes in hematological parameters, PPACK demonstrated dose dependent
thrombocytopenia. A standardized cuticle bleeding time was used as a measure of
perturbation of hemostasis. The agents were evaluated for significant increases
in bleeding time at doses up to eight times that needed to completely inhibit
venous thrombus formation. Unfractionated heparin displayed a significant
bleeding time effect at the dose required to inhibit venous thrombosis (100
u/kg+2 u/kg/min). Enoxaparin and PPACK caused significant bleeding time
extensions at four times the fully efficacious venous dose (800 u/kg+8 u/kg/min
and 30 microg/kg/min). By contrast, C921-78 did not significantly increase
bleeding time even at eight times the maximally effective dose (240 microg/kg+7.2
microg/kg/min). Our results demonstrate that specific inhibition of fXa can be
utilized to derive potent antithrombotic activity without disrupting
extravascular hemostasis.
PMID- 10781675
TI - Neurogenic vasodilation in rabbit basilar isolated artery: involvement of
calcitonin-gene related peptide.
AB - Neurogenic vasodilation in cranial arteries may be an important mechanism in the
pathogenesis of migraine headache. We describe a novel, in vitro assay to
characterise neurogenic vasodilator responses in endothelium-denuded segments of
rabbit isolated basilar artery, with particular focus on calcitonin-gene related
peptide (CGRP). In arterial segments precontracted with prostaglandin F(2alpha),
relaxations evoked by exogenously applied alphaCGRP (EC(50)=2.9 nM) were
inhibited by alphaCGRP-(8-37) (pA(2)=6.49) or by desensitisation resulting from
prior exposure to alphaCGRP. Relaxations evoked by exogenously applied vasoactive
intestinal polypeptide (VIP) (EC(50)=2.5 nM) were inhibited by VIP-(7-28) 1
microM. The 5-HT(1) receptor agonists L-771,331 ((3S)-3[N-(S)-alpha
methylbenzyl]aminomethyl-(S)-1-[2-(5-(2-oxo-1, 3-oxazolidin-4-ylmethyl)-1H-indol
3-yl)ethyl]pyrrolidine) and sumatriptan exerted contractile effects (EC(50)=293
and 95 nM, respectively). In neurogenic experiments, vasodilation evoked by
electrical field stimulation was markedly attenuated by pre-treatment with
capsaicin (10 microM) or by prior CGRP receptor desensitisation and to a lesser
extent by pre-treatment with VIP-(7-28) 1 microM. L-771,331 (100 nM) exerted a
weak inhibitory effect, marked only by a short reduction in the recovery time
(post-electrical stimulation) and sumatriptan (30 nM) had no effect. The
neurogenic response was potentiated by alphaCGRP-(8-37) 1 microM (reversible on
wash-out). Short application (5-10 min) of capsaicin (10 microM) produced
vasodilation that was inhibited by alphaCGRP-(8-37) 1 microM. These data suggest
that electrically evoked neurogenic vasodilation in rabbit basilar artery has a
large component resulting from the release of sensory neuropeptides in particular
CGRP and a smaller component involving the release of VIP.
PMID- 10781676
TI - Alpha(1)-adrenoceptor subtypes mediating contractions of the rat mesenteric
artery.
AB - The alpha(1)-adrenoceptor subtype(s) mediating contractions of the rat mesenteric
artery were investigated using the agonists methoxamine, cirazoline, P7480 (N-(4
pyridinyl)-1H-indol-1-amine) and subtype-selective antagonists including BMY 7378
(8-(-2(-4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-8-azaspiro(4, 5)decane-7,9,dione
dihydrochloride). pA(2) or apparent pK(B) values of antagonists against
methoxamine contractions correlated best with its pK(i) values at the cloned
alpha(1b)-(0.88), with cirazoline, antagonists affinities correlated equally well
with those at alpha(1a)-(0.79) or the alpha(1b)-(0.81) while with P7480
antagonist affinities correlated best with the alpha(1d)-adrenoceptor subtype
(0.94). The low affinity estimate for 5-methylurapidil (7.5) against the
alpha(1a)-selective cirazoline suggests an alpha(1A)-subtype mediating
contraction is unlikely. Shallow Schild plot slopes of subtype selective
antagonists against all three agonists are consistent with heterogeneity of
alpha(1)-adrenoceptors. P7480 (putative alpha(1D)-adrenoceptor-selective) acts
primarily at this subtype and at another which is more likely to be an alpha(1B)-
than an alpha(1A)-adrenoceptor. The results with both agonists and antagonists
are consistent with contractions of the rat mesenteric artery being mediated via
the alpha(1D)- and possibly alpha(1B)-adrenoceptor.
PMID- 10781677
TI - Pituitary adenylate cyclase activating peptide mediates inhibitory nonadrenergic
noncholinergic relaxation.
AB - We investigated the contribution of pituitary adenylate cyclase activating
peptide (PACAP) to inhibitory nonadrenergic noncholinergic (inhibitory-NANC)
relaxation of tracheal smooth muscle in cats. We also investigated the roles of
vasoactive intestinal peptide (VIP) and nitric oxide (NO) on this function.
Smooth muscle strips prepared from feline trachea were precontracted with 1
microM serotonin, and inhibitory-NANC relaxation was induced by electrical-field
stimulation in the presence of atropine and propranolol. PACAP-(6-38) (a
selective antagonist of PACAP; 1, 3 and 10 microM), VIP-(10-28) (a selective
antagonist of VIP; 1, 3 and 10 microM) and N(omega)-nitro-L-arginine methyl ester
(L-NAME, a selective NO synthase inhibitor; 3, 10 and 30 microM) each partially
but significantly attenuated the amplitude of inhibitory-NANC relaxation. The
effects of PACAP-(6-38) and VIP-(10-28) were additive. Addition of PACAP-(6-38)
and/or VIP-(10-28) further attenuated relaxation in the presence of L-NAME. These
results suggest that PACAP, VIP and NO contribute to the relaxation induced by
inhibitory-NANC in tracheal smooth muscle in cats, and that they mediate this
relaxation via different pathways.
PMID- 10781679
TI - Variations in the low levels of cyclin D1/BCL1 have prognostic value in chronic
lymphocytic leukemia.
AB - Cyclin D1 (CyD1)/BCL1 (PRAD1) is expressed at high levels in almost all cases of
mantle cell leukemia/lymphoma (MCL) and in rare cases of chronic lymphocytic
leukemia (CLL). The CyD1/BCL1 protein plays an important role in the progression
of cells through the G1 phase of cell cycle. Most of the CyD1/BCL1 protein
expression studies are performed using immunohistochemistry. We used a sensitive
solid-phase radioimmunoassay (RIA) to quantify CyD1 protein expression in 199
patients with CLL. Of these 137 patients were previously untreated with the rest
having had standard chemotherapeutic regimens including alkylating agents and
fludarabine before being referred to our center. Median white cell count in these
patients was 49x10(3) /microl (range 3.0-438.5x10(3)/microl), hemoglobin level
13.1 g/dl (range 5.2-17.3 g/dl), platelet count 157x10(3) /microl (range 10
377x10(3) /microl), age 58 (range 26-89), and beta2-microglobulin 2.75 mg/dl
(range 1.1-14.3). The median radioactivity (CPM) of mononuclear cells obtained
from 56 normal individuals was assigned a value of 1. There was no significant
variation in CyD1 levels among normal individuals (SD=0. 12). While most CyD1
levels in MCL varied from 6.5 to 15.6, the median CyD1/BCL1 in CLL was 1.4 with
75th percentile under 2.12. Rare CLL cases (3.5%) showed levels between 4 and
8.83. When divided into two groups at the median level, patients with higher
CyD1/BCL1 expression had shorter survival (P = 0.03). This remained true when
applied only to the previously untreated patients (P=0.05). Despite the
relatively low expression, the CyD1/BCL1 levels in univariate analysis were as
good or better predictors of survival than Binet (P = 0.03) or Rai (P = 0.05)
staging. Furthermore, CyD1/BCL1 levels correlated with serum beta2-microglobulin
(P = 0.001), white blood cell count (P = 0.004) and hemoglobin levels at the time
of collection (P = 0.0003) but not with lymphocyte count, platelet count or age.
The data demonstrate that CyD1/BCL1 is likely to play a significant role in the
biology of CLL and can be used as a prognostic indicator. Further studies to
clarify the role of CyD1 in the biology of CLL and its value as a prognostic
indicator at the time of diagnosis are encouraged.
PMID- 10781678
TI - Correlation of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of
oxidative DNA damage, and clinical features of hematological disorders: a pilot
study.
AB - The 8-hydroxy-2'-deoxyguanosine (8-OHdG), presently the most popular marker for
oxidative DNA damage, level has been reported to be elevated in patients with
various malignancies. In the present study, urinary 8-OHdG was examined in 44
patients with hematological disorders (13 malignant lymphoma, 11 adult T cell
leukemia/lymphoma (ATL), 10 acute leukemia, and 10 myelodysplastic syndrome
(MDS)) by an enzyme-linked immunosorbent assay. The pre-therapy level of urinary
8-OHdG in ATL patients was significantly elevated compared with normal controls
(25.3+/-12.9 vs. 11.9+/-7.3 ng/mg, P<0.05). Although patients with lymphoma,
acute leukemia and MDS also showed higher urinary 8-OHdG levels than normal
controls, the differences were not significant. However, two patients with
refractory anemia with excess blasts in transformation (RAEB-t) having extreme
monocytosis and neutrophilia showed exceptionally high urinary 8-OHdG levels
(161.0 and 218.9 ng/mg). Urinary 8-OHdG excretion increased transiently with
chemotherapy, and this fluctuation was significant irrespective of the disorder
(P<0.05). Interestingly, lymphoma patients with high LDH, advanced stage, poor
performance status or International Prognostic Index (IPI) of high/high
intermediate risk had significantly elevated urinary 8-OHdG levels (P<0.05
<0.001). These latter results suggest that urinary 8-OHdG may be a reliable
prognostic marker in lymphoma patients and should encourage large scale and long
term follow up studies.
PMID- 10781680
TI - Detection of t(14;18) in turkish follicular lymphomas using the polymerase chain
reaction.
AB - A t(14;18) translocation is closely associated with the follicular lymphoma but
is also seen in diffuse B cell lymphomas with a previous history of a follicular
lymphoma as well as de novo diffuse lymphomas. Estimation of the frequency of
t(14;18) in follicular lymphoma vary widely from 33 to 89%. Furthermore, no
extensive data have been published on the frequency of t(14;18) in Turkish cases
of follicular lymphoma. Representative tissue blocks from 67 patients with
follicular lymphoma, 12 cases of diffuse large B cell lymphomas and 11 cases of
reactive hyperplasias were examined for the presence of this translocation using
PCR. DNA probes capable of detecting rearrangement at both the major and minor
break point regions were employed. We could detect t(14;18) in 46 out of 67 cases
(68.7%) of follicular and 25% of diffuse large B cell lymphomas. In follicular
lymphomas 64.2% of these break points were at mbr and 4.5% were at the mcr
region. Review of the literature showed that comparable results have been
obtained previously using molecular techniques. Our data showed that despite the
relative infrequency of follicular lymphomas in the Turkish population these
lymphomas share a common molecular pathogenesis with involvement of bcl-2 gene
and background incidence of such rearrangement is similar in all populations,
regardless the incidence of folicular lymphoma.
PMID- 10781681
TI - Allogeneic stem cell transplantation for relapsed and refractory acute myeloid
leukemia patients with 11q23 abnormalities.
AB - Abnormalities involving chromosome band 11q23 are seen in de novo and therapy
related acute myeloid leukemia (AML). The role of hematopoietic stem cell
transplantation (SCT) in AML with 11q23 abnormalities is not well defined. We
present here the outcome of 14 AML patients with 11q23 abnormalities transplanted
beyond first complete remission (CR) or with primarily refractory disease. Eleven
cases were de novo and three therapy-related AML. At transplant, five patients
were in first untreated relapse, one second CR, one second relapse and seven had
refractory disease. All 14 patients underwent allogeneic SCT. Total body
irradiation was used in 93% of patients and cyclosporine-methotrexate for graft
versus-host disease prophylaxis in 71%. The relapse rate of engrafted patients
was 58%. Five year survival and disease-free survival were 14 and 7%,
respectively. Allogeneic SCT for AML with 11q23 abnormalities was of limited
benefit in this cohort of patients transplanted beyond first CR or with primarily
refractory disease.
PMID- 10781682
TI - 154 chromosome anomalies in hematologic malignancies.
PMID- 10781683
TI - Safety and efficacy of splenic irradiation in the treatment of patients with
idiopathic myelofibrosis: a report on 15 patients.
AB - Splenic irradiation in idiopathic myelofibrosis (IMF) has often been use d in
selected situations when other therapies were unefficient or contraindicated.
This could improve quality of life of patients, but literature remains rare in
this field. We have assessed the impact of splenic irradiation in 15 patients
with IMF. All of them were no longer responsive to usual treatments, and they
presented at least one of the following features: constitutional symptoms,
splenic pain, large splenic size, and anemia requiring >2 units of red blood cell
transfusion per month. The planned schedule of radiotherapy consisted in daily
fractions of 0.4-1 Gy. The median dose of radiotherapy per treatment was 9.8 Gy
(range, 0.6-30.5). The overall response rate was 59% with a median duration of 10
months (range, 1-19). Splenic irradiation was more effective on constitutional
symptoms, splenic pain, and spleen size. The best responses were noted when full
doses of radiotherapy could be delivered, and when patients were previously fewly
transfused. Splenic irradiation effectively palliates IMF-related symptoms, and
constitute an alternative therapy for patients refractory to usual treatments.
PMID- 10781685
TI - Enhanced ex vivo apoptosis of peripheral granulocytes is a sufficient factor of
neutropenia following myeloablative chemotherapy.
AB - Fourteen patients with hemopoietic and solid malignancies underwent dose
intensive chemotherapy, followed by haemopoietic stem cell grafting. Granulocyte
apoptosis was assessed as nuclear chromatin condensation, after ex vivo
incubation of blood samples for 3 h, followed by Acridine Orange staining.
Myeloablative therapy caused time-dependent increase in ex vivo granulocyte
apoptosis, being maximal at D+7 to D+9, thus preceding the development of
neutropenia (nadir values on D+13 to D+15). In vivo administration of G-CSF
(Neupogen) resulted into short-term decrease in apoptotic granulocyte numbers.
Hence, granulocyte apoptosis is an important factor of therapy-induced leukopenia
and could be modified by the G-CSF treatment.
PMID- 10781684
TI - Identification of acute myeloid leukemia patients with diminished expression of
CD13 myeloid transcripts by competitive reverse transcription polymerase chain
reaction (RT-PCR).
AB - Normal myeloid cells of monocytic and granulocytic origin express the
metallopeptidase cluster of differentiation 13 (CD13) on the surface just as
leukemic blasts in most acute myeloid leukemias (AML). A minor percentage of AML
patients, however, lack the surface expression of CD13 antigen. To study this
difference in CD13 surface expression, specific CD13 mRNA from 44 individuals
were quantified by competitive reverse transcription polymerase chain reaction
(RT-PCR). Absolute values for CD13 transcripts were normalised against
glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcript levels to control for
variations in sample preparation and mRNA degradation. By correlating normalised
CD13 transcript levels and CD13 surface expression, a subgroup of AML patients
was identified, having simultaneous diminished levels of myeloid CD13 transcripts
and surface expression of the corresponding antigen. For this subgroup we suggest
CD13/aminopeptidase N (APN) gene expression to be restricted primarily by limited
amounts of transcripts. For the majority of AML patients determinants in addition
to transcript levels must be involved in regulating CD13/APN gene expression.
PMID- 10781686
TI - p53 gene deletions in paraffin-preserved lymphoid tumors from irradiated mice.
AB - Experiments were performed to measure deletions in the p53 gene in paraffin
embedded tissues (tumors and control) derived from mice exposed to gamma-rays or
neutrons up to 28 years ago. Deletions in exons 1, 3, 4, 5, 6, 7 and 9 were
monitored by PCR and Southern blotting techniques. The results of these
experiments demonstrated p53 deletions in only 1/6 spontaneous tumors but in 5/6
gamma-ray-induced and 5/6 neutron-induced tumors. Exons deleted in tumors from
gamma-ray exposed mice were similar to those deleted in tumors from neutron
exposed mice. They document differences in spectra of p53 deletions in comparing
spontaneous radiation-induced tumors.
PMID- 10781687
TI - Amifostine cytotoxicity and induction of apoptosis in a human myelodysplastic
cell line.
AB - Amifostine (AMF), a phosphorylated aminothiol, has been used to treat
myelodysplastic syndrome (MDS), where it produces a stimulatory effect on
hematopoiesis in bone marrow. To determine if AMF also produced a direct effect
on human MDS cells, we planned a study to evaluate the effect of a continuous
exposure to AMF on a human MDS cell line. AMF was shown to have a growth
inhibitory effect on MDS cells, with an IC(50) of 14 microM after a 5 day
exposure. Cell cycle analysis revealed that a 5 day exposure to 20 microM AMF
increased the percentage of cells in G0/G1 and this was accompanied by a decrease
in the percentage of cells in S phase. Cytoflorometric and agarose-gel
electrophoretic analysis revealed that this effect correlated with cell membrane
alterations and DNA fragmentation consistent with an induction of apoptosis
without affecting the expression of p53 protein or inducing any lymphoid or
myeloid differentiation in the MDS cell line. We conclude that the continuous
exposure of a human MDS cell line to AMF is cytotoxic and associated with an
induction of apoptosis independent of alterations in p53 expression.
PMID- 10781688
TI - The inhibition of ERK/MAPK not the activation of JNK/SAPK is primarily required
to induce apoptosis in chronic myelogenous leukemic K562 cells.
AB - In this study, the downstream signaling of Bcr-Abl tyrosine kinase responsible
for apoptosis resistance was investigated. DNA fragmentation, a hallmark of
apoptosis, was observed after 2 days of herbimycin A treatment with a peak on 3
day. During the apoptosis induced by the treatment of herbimycin A, stress
activated protein kinase (SAPK) and p38 kinase were activated time- and dose
dependently, while extracellular signal-regulated kinase (ERK) was inhibited.
However, apoptosis was induced by the treatment of PD98059, a specific inhibitor
of MEK (MAPK or ERK kinase), not by the treatment of sorbitol, a strong activator
of SAPK and p38 kinase. Although K562 cells were very resistant to sorbitol
induced apoptosis, DNA fragmentation was induced rapidly in Jurkat, HL-60 and
U937 cells after exposure to sorbitol, despite that these apoptosis-sensitive
cells have similar or lower activities of JNK/SAPK and p38 kinase compared with
K562 cells after treatment of sorbitol. K562 cells had a much higher basal
activity of ERK/MAPK than other apoptosis-sensitive cell lines, which were very
susceptible to apoptosis induced by low dose of PD98059 compared with K562 cells.
In HL-60 cells, sorbitol-induced apoptosis was prevented by the treatment of
phorbol myristate 13-acetate (PMA), which activates the ERK/MAPK pathway, and
this was blocked by PD98059. From these results, it could be suggested that the
inhibition of ERK/MAPK not the activation of JNK/SAPK is primarily required to
induce apoptosis in K562 cells.
PMID- 10781689
TI - In vitro leukemia cell models of Ara-C resistance.
AB - Cells of the human leukemia line K562 were continuously exposed to cytosine
arabinoside (Ara-C) at increasing concentrations for 3 months. The resulting cell
line, termed K562/AC, showed 48-fold resistance to Ara-C, compared with the
parental K562 cells. The sensitivities of K562/AC to adriamycin (ADR),
vincristine (VCR) and etoposide (VP16) were similar to those of parental K562.
Gene analysis revealed that this cell line lacked expression of the deoxycytidine
kinase (dCK) gene, which was evident in Ara-C-sensitive cells. As in K562 cells,
multidrug resistance (MDR-1) and multidrug resistance protein (MRP) genes were
not expressed in K562/AC. We also established an in vitro model of Ara-C
resistance using phosphorothioate antisense oligonucleotides to dCK (dCK-AS).
Treatment of K562 with dCK-AS caused decreased dCK expression and 6- to 10-fold
increases in resistance to Ara-C, compared with that in cells treated with sense
oligonucleotides to dCK (dCK-S) or in non-transfected cells. The cells described
here may contribute to the study of a novel mechanism associated with Ara-C
resistance, in which reduced dCK activity may play an important role.
PMID- 10781690
TI - Partial restoration of all trans retinoic acid (ATRA) sensitivity by compactin in
ATRA-resistant leukemic cells (ATRA-R HL-60).
AB - The resistance to all trans retinoic acid (ATRA) differentiating treatment is a
consequence, in most of the cases, of either increased catabolism or down
regulation of ATRA uptake. Recently, we have shown that ATRA efficiency to
differentiate HL-60 cells was enhanced about 30 times after its incorporation
into Low Density Lipoprotein (ATRA-LDL). Here, we attempted to differentiate the
ATRA-resistant HL-60 cells by ATRA-LDL at high concentrations up to 10 microM. No
significant differentiating effect was observed, although the LDL receptor sites
were evidenced in these cells. To increase the number of LDL receptors, the cells
were pre-incubated in lipoprotein-deprived serum medium and compactin (2 microM),
both ATRA and ATRA-LDL induced gradual increase of cell differentiation (35%+/-1
and 51.5%+/-5 at 10 microM of ATRA and ATRA-LDL respectively). At 2 and 8 microM,
the intracellular concentrations of ATRA were respectively three and four times
higher when incorporated into LDL. In addition, ATRA-LDL, in the medium, was
better protected against degradation than ATRA. The surprising restoration of
free ATRA sensitivity after treatment with compactin suggested the implication of
new mechanisms unrelated to the LDL-receptor endocytosis but involving the non
sterol pathway.
PMID- 10781691
TI - Animal models of acute drug-induced akathisia - a review.
AB - Akathisia is a complex neurobehavioural side effect of neuroleptics and some
other drugs which is characterised by subjective report and objective
manifestations of restlessness. Its pathophysiology is poorly understood and
there are many limitations to its investigation in humans. This paper reviews the
various attempts that have been made in modelling acute akathisia in animals.
Homologous as well as isomorphic models have been attempted, but most models are
partial as they reproduce either the subjective or the objective features of the
syndrome. None of the available models has been fully validated. Neuroleptic
induced defecation in the rat, even though constrained by a lack of symptom
similarity and thereby face validity, has been most studied as a model of
subjective akathisia. Rat models of restlessness, in particular those involving
the use of serotonergic drugs or lesions of the ventral tegmentum or medial
prefrontal cortex, are interesting partial models that should be further
investigated. Neuroleptic-induced akathisia is observed in primates and has been
modelled in dogs, and these should be studied further for their validation. It is
also necessary to consider the subtypes of akathisia in the attempts to develop
these models.
PMID- 10781692
TI - Contingent tolerance to amphetamine hypophagia: new insights into the role of
environmental context in the expression of stereotypy.
AB - A growing literature attests to the fact that the environment in which a drug is
given can have a profound effect on the development and expression of tolerance
and sensitization. The dominant paradigm for studying such context-dependency is
based on Pavlovian conditioning, in which a distinctive environment serves as a
conditioned stimulus. Context dependency is demonstrated when tolerance or
sensitization is expressed only in the environment in which the drug was given
chronically. An alternative paradigm for studying context-dependency is to
manipulate the contingencies of reinforcement operating in the environment in
which the drug is administered. For example, tolerance to amphetamine-induced
hypophagia is contingent on having access to food while intoxicated [Carlton PL,
Wolgin DL. Contingent tolerance to the anorexigenic effects of amphetamine.
Physiol Behav 1971;7:221-223]. Such context-dependency can be explained in terms
of an instrumental (or operant) conditioning model, in which food serves as a
reinforcer for the learned suppression of stereotyped movements that interfere
with ingestion. Research based on this model suggests that the expression of
sensitized stereotyped responses is subject to an operant level of control.
PMID- 10781693
TI - Neuronal-glial interactions and behaviour.
AB - Both neurons and glia interact dynamically to enable information processing and
behaviour. They have had increasingly intimate, numerous and differentiated
associations during brain evolution. Radial glia form a scaffold for neuronal
developmental migration and astrocytes enable later synapse elimination.
Functionally syncytial glial cells are depolarised by elevated potassium to
generate slow potential shifts that are quantitatively related to arousal, levels
of motivation and accompany learning. Potassium stimulates astrocytic
glycogenolysis and neuronal oxidative metabolism, the former of which is
necessary for passive avoidance learning in chicks. Neurons oxidatively
metabolise lactate/pyruvate derived from astrocytic glycolysis as their major
energy source, stimulated by elevated glutamate. In astrocytes, noradrenaline
activates both glycogenolysis and oxidative metabolism. Neuronal glutamate
depends crucially on the supply of astrocytically derived glutamine. Released
glutamate depolarises astrocytes and their handling of potassium and induces
waves of elevated intracellular calcium. Serotonin causes astrocytic
hyperpolarisation. Astrocytes alter their physical relationships with neurons to
regulate neuronal communication in the hypothalamus during lactation, parturition
and dehydration and in response to steroid hormones. There is also structural
plasticity of astrocytes during learning in cortex and cerebellum.
PMID- 10781694
TI - Effects of selected serotonin 5-HT(1) and 5-HT(2) receptor agonists on feeding
behavior: possible mechanisms of action.
AB - Serotonin (5-HT) receptor agonists with high affinity for the different subtypes
(i.e. 5-HT(1A-1F), 5-HT(2A-2C)) of the 5-HT(1)- and 5-HT(2) receptor families
have been shown to affect ingestive behavior. It has been assumed that: (1)
stimulation of hypothalamic 5-HT(2C) or 5-HT(1B) receptors leads to a
behaviorally specific hypophagic effect by accelerating satiety processes; (2)
stimulation of 5-HT(2A) receptors leads to a disruption of the feeding cascade;
and (3) stimulation of 5-HT(1A) and 5-HT(2B) receptors leads to a hyperphagic
effect. The present paper reviews studies performed with the relatively selective
receptor agonists ipsapirone (5-HT(1A)), CP-94,253 (5-HT(1B)), BW 723C86 (5
HT(2B)) and ORG 37684 (5-HT(2C)), as well as the nonselective receptor agonists
TFMPP (5-HT(1B/2C)), m-CPP (5-HT(2C/1B)) and DOI (5-HT(2A/2C)) in a variety of
feeding paradigms in rats, both after systemic and local injection. These studies
support a role for other neuroanatomical regions (i.e. brain stem) and behavioral
mechanisms (i.e. appetitive processes) in the hypophagic effects of these
compounds, possibly as a function of the administered dose. Studies with 5-HT
receptor antagonists indicate that the proposed role of particular 5-HT(1/2)
receptor subtypes in the hypophagic effects of these 5-HT receptor agonists may
be more complicated than originally thought. Further characterization of the role
of 5-HT(1/2) receptor subtypes in the control of ingestive behavior will require
extensive pharmacological and behavioral studies, using more selective receptor
agonists and antagonists and different behavioral procedures, as well as
verification in transgenic animals.
PMID- 10781695
TI - The amygdala theory of autism.
AB - Brothers (Brothers L. Concepts in Neuroscience 1990;1:27-51) proposed a network
of neural regions that comprise the "social brain", which includes the amygdala.
Since the childhood psychiatric condition of autism involves deficits in "social
intelligence", it is plausible that autism may be caused by an amygdala
abnormality. In this paper we review the evidence for a social function of the
amygdala. This includes reference to the Kluver-Bucy syndrome (which Hetzler and
Griffin suggested may serve as an animal model of autism). We then review
evidence for an amygdala deficit in people with autism, who are well known to
have deficits in social behaviour. This includes a detailed summary of our recent
functional magnetic resonance imaging (fMRI) study involving judging from the
expressions of another person's eyes what that other person might be thinking or
feeling. In this study, patients with autism or AS did not activate the amygdala
when making mentalistic inferences from the eyes, whilst people without autism
did show amygdala activity. The amygdala is therefore proposed to be one of
several neural regions that are abnormal in autism. We conclude that the amygdala
theory of autism contains promise and suggest some new lines of research.
PMID- 10781696
TI - The neuropsychology of preclinical Alzheimer's disease and mild cognitive
impairment.
AB - Subjects in the preclinical stages of Alzheimer's disease (AD) typically record
neuropsychological performance between that of healthy older individuals and
demented patients. More specifically, deficits on measures of verbal episodic
memory are commonly reported in these patients, while other cognitive functions
(e.g. language, praxis and executive function) seem to be spared. A similar
neuropsychological profile is observed in elderly subjects with mild cognitive
impairment (MCI), a disorder that is attracting increasing research interest.
Evidence from lesion and functional imaging studies, as well as volumetric
imaging in probable AD and MCI patients, suggests that the cognitive deficits
observed in these disorders may be related to medial temporal lobe dysfunction.
An issue currently under investigation is whether MCI represents the preclinical
stages of AD or a distinct and static cognitive aetiology. In an attempt to
address this issue, present investigations are adopting a convergent approach to
the detection of preclinical AD, where multiple risk factors are considered when
making a diagnosis.
PMID- 10781697
TI - Sex differences in thermal nociception and morphine antinociception in rodents
depend on genotype.
AB - It has been appreciated for some time that the sexes can differ in their
sensitivity to pain and its inhibition. Both the human and rodent literatures
remain quite contentious, with many investigators failing to observe sex
differences that others document clearly. Recent data from our laboratory have
pointed to an interaction between sex and genotype in rodents, such that sex
differences are observed in some strains but not others. However, these studies
employed inbred mouse strains and are thus not directly relevant to existing
data. We presently examined whether the observation of statistically significant
sex differences in nociception and morphine antinociception might depend on the
particular outbred rodent population chosen for study. Rats of both sexes and
three common outbred strains were obtained from three suppliers (Long Evans,
Simonsen; Sprague Dawley, Harlan; Wistar Kyoto, Taconic) and tested for
nociceptive sensitivity on the 49 degrees C tail-withdrawal assay, and
antinociception following morphine (1-10mg/kg, i.p.). In further studies, three
outbred populations of mice (CD-1, Harlan; Swiss Webster, Harlan; Swiss Webster,
Simonsen) were bred in our vivarium for several generations and tested for tail
withdrawal sensitivity and morphine antinociception (1-20male, and no significant
difference. In a separate study in which the estrous cycle was tracked in female
mice, we found evidence for an interaction between genotype and estrous phase
relevant to morphine antinociception. However, estrous cyclicity did not explain
the observed sex differences. These data are discussed with respect to the
existing sex difference and pain literature, and also as they pertain to future
investigations of these phenomena.
PMID- 10781698
TI - Depression and health-related quality of life in ethnic minorities seeking care
in general medical settings.
AB - BACKGROUND: To examine ethnic groups differences in (a) prevalence of depressive
disorders and (b) health related quality of life in fee-for-service and managed
care patients (n=21504) seeking care in general medical settings. METHODS: Data
are from the Medical Outcomes Study, a multi-site observational study of
outpatient practices. The study screened patients of clinicians (family practice,
internal medicine, cardiology, diabetology and endocrinology) for four chronic
medical conditions; depression, coronary heart disease, hypertension and
diabetes. A brief eight-item depression screener followed by the Diagnostic
Interview Schedule-Depression Section (DIS) for screener positives identified
depressed patients (n=2195). The Short Form Health Survey (SF-36) assessed health
related quality of life. Patient self-report determined ethnicity. RESULTS:
Before adjusting for demographic factors, African-Americans and Hispanics had
highest rates of depressive symptoms. Asian-Americans had the lowest. After
adjusting for demographics (particularly gender and income), we found few
statistically significant differences in prevalence or severity of depression.
However, among the depressed, Whites were the most, and African-Americans the
least likely to report suicidal ideation (p<0. 01), and Hispanics and Whites were
more likely to have melancholia (p<0.01). African-Americans reported the poorest
quality of life. LIMITATIONS: DSM III criteria (though few changes in DSM IV),
and relatively small sample size of Asian-Americans compared to other groups.
CONCLUSIONS: Gender and socioeconomic status are more significant factors than
ethnicity in determining risk for depressive disorder. However, ethnic
differences in symptom presentation, and health-related quality of life could
have clinical and social consequences, and merit further study.
PMID- 10781699
TI - History of childhood attention deficit hyperactivity disorder (ADHD) features
among adults with panic disorder.
AB - BACKGROUND: The prevalence of ADHD features during childhood and its relationship
to the course and presentation of panic in adults with panic disorder was
examined. METHODS: The presence of DSM-III-R ADHD was retrospectively ascertained
in a cohort of 85 adults with panic disorder by structured interview. RESULTS:
Childhood ADHD features occurred in 23.5% of panic subjects; 9.4% satisfied full
DSM-III-R criteria for ADHD, 14.1% had 'subthreshold' diagnoses. Two-thirds of
panic patients with ADHD indicated persistence of symptoms into adulthood. Fewer
had married or completed college than those with panic alone. There was no
significant difference in clinical pattern and severity of panic, or comorbidity
of adult Axis I and childhood anxiety disorders in both groups. CONCLUSION: Given
its frequency and persistence, ADHD comorbidity is an important clinical
consideration in all panic patients. Its co-occurrence does not influence the
clinical pattern of panic, but may contribute to adverse social outcome.
PMID- 10781701
TI - The development of major depressive episodes during the course of dysthymic and
episodic major depressive disorders: a retrospective examination of life events.
AB - BACKGROUND: The present study examined whether stressful life events are
associated with the development of major depressive episodes (MDEs) in a
longitudinal, retrospective study of dysthymic and episodic major depressive
disorders. METHODS: Sixty-seven outpatients with DSM-III-R dysthymia and 38
outpatients with non-chronic major depression were followed up 30-60 months after
entry into the study. Follow-up assessments included a modified version of
Paykel's (1997) Interview for Recent Life Events (IRLE) and Keller et al.'s
(1987) Longitudinal Interval Follow-up Evaluation. Life events were assessed
retrospectively in the 6 months before the most recent MDE or in the 6 months
before follow-up for patients without a MDE. RESULTS: In dysthymic patients, MDEs
were significantly associated with a new life event in the context of an ongoing
chronic stressor. In episodic major depressive patients, relapses were associated
with new life events regardless of an ongoing chronic stressor. LIMITATIONS: This
was a retrospective study. It was also a conservative test of the association
between life events and MDEs as the follow-up period over which life events were
assessed was long, increasing the possibility of forgetting; events occurring
less than 1 month before relapse were excluded to avoid confounding the event
with the MDE; life events were assessed for a more distant time period for
patients who experienced MDEs than those who did not; and an abbreviated version
of the IRLE was used which may have failed to identify less severe events.
CONCLUSIONS: This study suggests that life events may play a role in the onset of
MDEs in persons with dysthymic disorder and those with major depressive disorder.
Thus, clinicians should monitor dysthymic patients after a stressful life event,
particularly if it occurs in the context of a chronic, ongoing stressor.
PMID- 10781700
TI - Study of the concurrent validity of the Calgary Depression Scale for
Schizophrenics (CDSS).
AB - The aim of this study was to investigate the concurrent validity of the French
language version of the Calgary Depression Scale for Schizophrenics (CDSS).
Ninety-five schizophrenic patients meeting the DSM-III-R criteria were enrolled
in the study. The depressive symptoms were evaluated using the Calgary Depression
Scale for Schizophrenics (CDSS), Hamilton Depression Rating Scale (HDRS),
Montgomery and Asberg Rating Scale (MADRS), and Widlocher Psychomotor Retardation
Scale (ERD). The psychotic symptoms were evaluated with the Positive and Negative
Syndrome Scale (PANSS) and the extrapyramidal symptoms with the Extrapyramidal
Syndrome Rating Scale (ESRS). The CDDS was significantly correlated with all the
conventional depression-rating scales. We only found significant positive
correlations between the CDSS and the PANSS-positive sub-scale. The CDSS total
score was significantly correlated with some PANSS-positive items (delusions and
hallucinatory behaviour). No significant correlation between the depression
rating scales and the PANSS-negative sub-scale was observed. For all the
depression-rating scales, no correlation with the extrapyramidal symptom was
evidenced. The results confirmed the validity of the CDSS in the evaluation of
depression in schizophrenia. The relationship between depression and the positive
symptoms of schizophrenia is discussed.
PMID- 10781702
TI - Who becomes depressed? The Islington community study of older people.
AB - BACKGROUND: Depression in older people is common and debilitating and associated
with physical ill health. This is the first study of risk factors for depression
in a representative sample of older people selected for high vulnerability
because of physical ill health. METHOD: Subjects identified in an epidemiological
community survey of morbidity in people > or =65 years old, who had activity
limitation (ADL) but no psychiatric morbidity were reinterviewed after 3 years.
RESULTS: 79 (90%) of subjects were interviewed. Ten percent developed pervasive
depression and 24% screened positive for depression. This latter group were more
likely to consult doctors than others with similar levels of disability (P<0.005)
mainly because of an acute physical illness. Frequent pain was associated with
the development of depression (P<0.02). CONCLUSION: Older people who are ADL
limited are known to be at high risk for depression. For the majority who do not
become depressed, chronicity of illness does not lead to depression. Those who
become depressed are most likely to be those with an acute illness and those who
are in pain. They will usually increase their consultation rate with doctors but
will not complain of depression. They may be undertreated for both pain and
depression. Further studies are needed to confirm other risk factors.
PMID- 10781703
TI - Comparison of neurochemical effects of the monoamine oxidase inhibitors
phenelzine, moclobemide and brofaromine in the rat after short- and long-term
administration.
AB - BACKGROUND: Chronic administration of several irreversible monoamine oxidase
(MAO) inhibitors induces a down-regulation of tryptamine and 5
hydroxytryptamine(2) receptors in rat brain, but there is a paucity of
information available on the effects of reversible MAO-A inhibitors on these
receptors. METHODS: Acute and chronic experiments were conducted in rats and the
effects of the irreversible monoamine oxidase inhibitor, phenelzine and the
reversible MAO type-A inhibitors, moclobemide and brofaromine, on tryptamine and
5-hydroxytryptamine(2) receptors were analysed using radioligand binding
techniques. In addition, activities of MAO-A and -B were determined
radiochemically and brain and/or urine levels of tryptamine, 5-hydroxytryptamine,
3-methoxy-4-hydroxyphenylglycol (MHPG), beta-phenylethylamine, brofaromine and
moclobemide were determined by chromatographic procedures. RESULTS: After 30 days
of administration, moclobemide and brofaromine selectively inhibited brain MAO-A
activity and phenelzine inhibited MAO-A and -B to equal extents. All three drugs
caused a significant down-regulation of tryptamine receptors, whereas only
phenelzine significantly down-regulated 5-hydroxytryptamine(2) receptors. In a
comparison of phenelzine and brofaromine, both caused marked elevations of
urinary tryptamine and decreases of urinary MHPG levels, while only phenelzine
increased beta-phenylethylamine levels. After 14 days of administration,
phenelzine, but not moclobemide or brofaromine, significantly increased levels of
tryptamine in brain; all three drugs significantly increased 5-HT levels.
LIMITATIONS: 24-h urine samples were not collected for moclobemide-treated
animals and brain levels of tryptamine were not measured after 30-day
administration. CONCLUSIONS: These studies revealed marked neurochemical
differences among phenelzine, moclobemide and brofaromine which could contribute
to their actions in the clinical setting.
PMID- 10781704
TI - Postnatal depression in Japanese women. Detecting the early onset of postnatal
depression by closely monitoring the postpartum mood.
AB - OBJECTIVES: The terminology and definition of mood disturbance during the early
postpartum period has yet to be clearly elucidated among clinical practitioners.
Criteria for maternity blues have not been well established, and it may overlap
with the beginning of a postnatal depression. The aims of the present study, are
firstly to survey the symptomatic features of mood disturbance in the very early
postpartum period and secondary, to develop a guideline for detecting and
predicting postnatal depression during the same period using a simple screening
technique. SUBJECTS AND METHODS: Eighty-eight mothers recruited from a maternity
ward for the prospective study completed the whole protocol. Two methods were
used to survey the symptomatic features of mood disturbance; (1) interview and
(2) self-report questionnaires. The interviews were carried out twice. At three
weeks postpartum, the Schedule for Affective Disorder and Schizophrenia
(SADS)/Research Diagnostic Criteria was administered, together with an interview
of the symptoms of "maternity blues". The SADS interview was re-administered at
three months postnatally. Two self-report questionnaires addressing mood
disturbance were administered: (1) Maternity Blues Scale; (Stein, 1980). (2)
Edinburgh Postnatal Depression Scale (EPDS; Cox et al., 1987). The Maternity
Blues Scale was administered on the first five consecutive postnatal days. The
EPDS was administered on the fifth day, one month and three months postnatally.
In addition, the Life Event Scale (Burgha et al., 1985) was also administered at
one month postnatally. Obstetric notes were also examined. RESULTS: At the first
interview, 12 mothers were diagnosed with postnatal depression and 10 of these
had their onset within one week. At the second interview three additional mothers
were newly diagnosed with depression. In all mothers, depression was detected at
one month using the EPDS, with a cut-off of 8/9. The EPDS scores on the fifth
postnatal day were also higher in the depressed mothers and could detect early
onset of postnatal depression. CONCLUSION: The use of the EPDS during the early
postnatal days, can be a simple and useful screening instrument for the onset of
early postnatal depression.
PMID- 10781705
TI - A note on suicidal deterioration with recovered memory treatment.
AB - BACKGROUND: Many patients who have been told they have Multiple
Personality/Dissociative Identity Disorder (MPD/DID) seem to have deteriorated
clinically after being so diagnosed. We report here the results of a survey of
suicide attempts in patients diagnosed as having MPD and a comparison group
hospitalized with a mood disorder. METHODS: Twenty individuals who had been
diagnosed as having MPD, had developed false memories, and had relinquished them,
were surveyed with respect to suicide attempts before and after the diagnosis.
Twelve of those approached agreed to provide data and were compared with 12
patients from an in-patient mood disorders unit, matched for age and sex.
RESULTS: In the MPD group more patients attempted suicide after being diagnosed
than before and they made more separate attempts at suicide than before. The
reverse was true in the comparison group with patients and suicide attempts
before and after hospitalization. Comparing the numbers of attempts in the groups
before diagnosis/hospitalization and afterward Chi(2)=20.177, DF=1, P<0.001.
LIMITATIONS AND CONCLUSIONS: Both samples were highly selected, and the
comparison group does not provide an exact control. Nevertheless, the results
support a trend in the literature that finds the diagnosis of multiple
personality disorder and the use of recovered memory treatment are harmful.
PMID- 10781706
TI - Depressive episodes of bipolar disorder in early teenage years: changes with
increasing age and the significance of IQ.
AB - BACKGROUND: Depressive (or depression-like) episodes are the most common
manifestations of bipolar affective disorder in early teenage years. The present
paper analyses the clinical features and their changes over time in these
episodes. METHODS: By a prospective study on children who had their first
affective or psychotic episodes between the ages of ten and fifteen, those who
eventually met the ICD 10 diagnostic criteria for bipolar disorder were selected
and followed up. RESULTS: There were three boys and nine girls. Their early
depressive episodes were characterised by psychotic features and clinging to the
mother in most cases, and in some by brief episodes and/or a good response to
sulpiride. However, these characteristics tended to disappear with increasing
age. Five children (42%) had an IQ of 61-75. LIMITATIONS: Generalisability of the
results is limited because of the small number of patients and the lack of
control groups. CONCLUSIONS: Bipolar disorder in early teenage years may show
clinical features and a drug response that are different from those in adulthood.
Low IQ may expedite the onset of bipolar disorder.
PMID- 10781708
TI - Thrombosis prophylaxis in hospitalised medical patients: does prophylaxis in all
patients make sense?
AB - BACKGROUND: Most studies on thrombosis prophylaxis focus on postoperative venous
thrombosis. In medical wards thrombosis prophylaxis is generally restricted to
patients who are immobilised. Our primary aim was to investigate the incidence of
venous thrombosis in a general internal ward, to assess whether more rigorous
prophylaxis would be feasible. METHODS: We investigated the incidence of venous
thrombosis in patients hospitalised from 1992 to 1996 and related our findings to
literature reports. RESULTS: The incidence of symptomatic venous thrombosis in
internal patients during hospitalisation was 39/6332 (0.6%). Among these 39
patients, 24 had a malignancy, whereas 876 out of all 6332 patients had a known
malignancy. So, the incidence in this group with cancer was 2.7% compared with
0.3% (15/5456) in the non-cancer group (relative risk for venous thrombosis due
to malignancy was 10.0 (95%C.I. 5.3-18.9). CONCLUSION: The incidence of venous
thrombosis during hospitalisation in a department of general internal medicine is
low and does not justify prophylaxis in all internal patients. Cancer is a strong
risk factor for hospital-acquired thrombosis in the medical ward. Further studies
may answer the question as to whether thrombosis prophylaxis in this subgroup is
feasible.
PMID- 10781707
TI - Serum cholesterol levels and panic symptoms in patients with panic disorder: a
preliminary study.
AB - BACKGROUND: Although some previous research has focused on the relationship
between panic disorder (PD) and a high total cholesterol (TC) level, it is still
controversial. Recently, researchers have reported the heterogeneity of clinical
symptoms in PD and the complexity of the correlations found among them.
Therefore, the controversy on the TC level in PD may be due to the existence of
clinical subgroups in PD. It is important to ascertain whether or not an elevated
TC level in patients with PD is associated with specific panic symptoms. METHODS:
In 104 drug-free patients with PD, we examined the relationship between TC level
and each of several panic symptoms occurring at the time of panic attacks (PAs),
which included anticipatory anxiety, agoraphobia, and 13 panic symptoms based on
the DSM-III-R. RESULTS: Stepwise regression analysis revealed a significant
effect of the presence of the symptom 'fear of dying' on TC levels. Patients with
a fear of dying had a significantly higher TC level than those without it.
LIMITATIONS: The relatively small sample size may limit the generalizability of
our findings. DISCUSSION: These data suggest that TC level may be associated with
panic symptoms in patients with PD.
PMID- 10781709
TI - High-frequency oscillatory ventilation in pediatric patients.
AB - BACKGROUND: High-frequency oscillatory ventilation (HFOV) is a ventilatory mode
using small tidal volumes with low phasic pressures at supraphysiological
frequencies. Beyond the neonatal period there are distinct lung diseases for
which HFOV is used. Data of 35 children who deteriorated on conventional
ventilation were retrospectively analysed in two tertiary pediatric intensive
care units. METHODS: Depending on the underlying pulmonary pathophysiology, three
strategies were employed. First, the 'open-lung' strategy designed to rapidly
recruit and maintain optimal lung volume in DAD (n=27) and pulmonary hemorrhage
(n=5). Second, the 'low-volume' strategy in persistent air leak (n=1) where,
after an initial identical approach, mean airway pressure (MAP) is reduced until
the air leak ceases. Third, the 'open-airway' strategy in obstructive airway
disease (n=5) where MAP is used to recruit and stent the airways. RESULTS: Seven
patients died, two due to respiratory failure. Three patients developed an air
leak. Nine patients developed chronic lung disease. There was a significant
decrease of the oxygenation index (OI) in the survivors. In the two patients who
died of respiratory failure, the OI increased. CONCLUSION: If certain conditions
are met, HFOV appears a safe and effective mode of ventilation in pediatric
respiratory failure.
PMID- 10781710
TI - Need to increase awareness among family doctors and medical specialists of
rickettsioses as an import disease in non-endemic areas.
AB - Europeans travelling to (sub)-tropical countries have an increased risk for
infections with Rickettsia. As serious consequences are associated with delay in
specific antibiotic therapy, unequivocal diagnosis of this condition is needed.
We focus here on the benefits of early, and consequences of late laboratory
diagnosis, and emphasise the need of an increased awareness of rickettsioses
among family doctors, as well as medical specialists, in non-endemic areas when
evaluating patients with travel associated fever.
PMID- 10781711
TI - Acute epiglottitis as a cause of airway obstruction in an adult patient.
AB - Epiglottitis in adults is a dangerous infectious disease with a rising incidence
and potential fatal complications as illustrated in this case report. Like in
children, skilled and aggressive airway protection with appropriate antibiotic
therapy have been effective in reducing mortality.
PMID- 10781712
TI - Pulmonary alveolar proteinosis: a complication in patients with hematologic
malignancy.
AB - We present the case of a patient with acute myeloid leukemia and secondary
Pulmonary Alveolar Proteinosis (PAP), which is an underestimated cause of a
persistent pulmonary infiltrate in patients with hematologic malignancies often
accompanied by neutropenia due to therapy. Diagnosis is established by performing
Periodic Acid-Schiff reaction (PAS) stains and transmission electron microscopy
(EM) on bronchoalveolar lavage (BAL) fluid. We wish to stress the importance of
the early recognition of PAP, which is potentially reversible, and routinely
performing PAS staining on BAL fluid in patients with a hematologic disease
especially myeloid disorders and a persistent lung infiltrate.
PMID- 10781713
TI - Diagnosis and treatment of brucellosis.
PMID- 10781714
TI - Speciation of elements in NIST particulate matter SRMs 1648 and 1650
AB - X-ray absorption fine structure (XAFS) spectra for S, Cl, V, Cr, Mn, Cu, Zn, As,
Br, Cd and Pb and Mossbauer spectra for Fe have been obtained for two National
Institute of Standards and Technology (NIST) particulate matter (PM) standard
reference materials (SRMs): urban PM (SRM 1648) and diesel PM (SRM 1650). The
spectral data, complemented by information on elemental concentrations from
proton-induced X-ray-emission (PIXE) spectroscopy, were used to interpret the
speciation of these elements in these complex materials. It appears that all the
metallic elements investigated occur in oxidized forms, principally as sulfates
in the diesel PM SRM and as sulfates, oxides, and possibly other forms (e.g.
clays?) in the urban PM. A minor fraction of the sulfur and major fractions of
the halogens, Cl and Br, occur as organosulfide (thiophene) and organohalide
occurrences, respectively, that must be associated with the abundant carbonaceous
matter that constitutes the major component of the two PM SRMs. Most of the
sulfur, however, occurs as sulfate in the urban PM and as bisulfate in the diesel
PM. In addition, elemental oxidation states have been determined directly by the
spectroscopic techniques. Such information is often the key parameter in
determining the toxicity and solubility of specific elements in PM, both of which
are important in understanding the threat that such elements may pose to human
health. For the two HAP elements, Cr and As, for which the toxicity depends
greatly on oxidation state, the XAFS data showed that both elements are present
in both SRMs predominantly in the less toxic oxidation states, Cr(III) and As(V).
The potential of the XAFS spectra for use as source apportionment signatures is
illustrated by reference to chromium, which exists in these two PM SRMs in very
different forms.
PMID- 10781715
TI - Chemical speciation of nickel in fly ash by phase separation and carbon paste
electrode voltammetry
AB - In a risk-based approach to cost-effective management of power plant emissions,
chemical speciation of fly ash is required. A quantitative but indirect
separation of nickel phases by sequential extraction was undertaken in
conjunction with direct analysis of the sulfidic nickel phase by carbon paste
electrode voltammetry (CPEV). Four ash samples produced in a laboratory
combustion system from burning high- and low-sulfur residual oil at excess O(2)
of 1 and 2-3 mol% were studied. The extractions yielded five phases of nickel.
The CPEV analysis of sulfidic nickel in the ash and extraction residues was
performed in pH 5 acetate. The anodic peak (-0.1 V) unique to Ni(3)S(2),
distinguishing it from NiS and NiS(2), was found to be absent from these ash
samples. The CPEV method was consistent with phase extraction, which showed
NiSO(4) being predominant with very low proportions of sulfidic nickel.
PMID- 10781717
TI - Partitioning behavior of trace elements during pilot-scale combustion of
pulverized coal and coal-water slurry fuel
AB - Release pathways for inorganic hazardous air pollutants (IHAPs) from a pilot
scale, down-fired combustor (DFC) when firing pulverized coal (PC) and coal-water
slurry fuel (CWSF) were identified and quantified to demonstrate the effect of
fuel form on IHAP partitioning, enrichment and emissions. The baghouse capturing
efficiency for each element was calculated to determine the effectiveness of IHAP
emission control. Most of the IHAPs were enriched in the fly ash and depleted in
the bottom ash. Mercury was found to be enriched in the flue gas, and
preferentially emitted in the vapor phase. When firing CWSF, more IHAPs were
partitioned in the bottom ash than when firing PC. Significant reduction of Hg
emissions during CWSF combustion was also observed.
PMID- 10781716
TI - Interlaboratory comparison of HPLC-fluorescence detection and GC/MS: analysis of
PAH compounds present in diesel exhaust.
AB - For laboratories involved in polycyclic aromatic hydrocarbon (PAH) analyses in
environmental samples, it is very useful to participate in interlaboratory
comparison studies which provide a mechanism for comparing analytical methods.
This is particularly important when PAH analyses are routinely done using a
single technique. The results are reported for such an interlaboratory comparison
study, in which the four selected participating laboratories quantitatively
analyzed several PAH compounds in diesel exhaust samples. The samples included
particle and vapor phase extracts collected and prepared at Michigan
Technological University (MTU PE and MTU VE, respectively), a diesel particle
extract prepared by the National Institute for Standards and Technology (NIST,
SRM 1975), and a fully characterized diesel particle sample (NIST SRM 1650). One
of the laboratories used only HPLC-FLD, one used only GC/MS and two laboratories
used both methods for the routine analysis of PAH in environmental samples. Data
were obtained for five PAH compounds: fluoranthene, pyrene, benz[a]anthracene,
benzo[a]pyrene, and benzo[g, h,i]perylene. The mean PAH levels found for SRM 1650
were outside the range reported by NIST. The range in the reported means was from
24% lower than certified for benz[a]anthracene to 41% higher for
benzo[g,h,i]perylene. For the previously uncharacterized samples in this study
(SRM 1975, MTU PE and MTU VE), two-thirds of the reported results were higher for
the HPLC-FLD method than for the GC/MS. The range in differences between methods
was from-54 to+31% calculated as the difference in GC/MS value relative to the
HPLC value for each of the compared compounds. Coefficients of variation for the
uncharacterized samples appeared to be higher, in most (but not all) cases, for
the HPLC-FLD than for the GC/MS. The resolution of certain PAH isomers (e.g.
benz[a]anthracene and chrysene, or the benzofluoranthenes), was better, as
expected, for HPLC than for GC. Generally lower detection limits (by an order of
magnitude or more) were reported for GC/MS than for HPLC-FLD. On the basis of
this limited study, it seems as though significant differences may exist between
laboratories, if not between methods, in the analysis of certain PAH compounds in
real diesel samples by HPLC-FLD compared to GC/MS. If possible, measurements
should be made using both methods. This is particularly important where potential
interferences are undefined or subject to change, as is frequently the case with
real environmental samples.
PMID- 10781718
TI - Catalytic effects of carbon sorbents for mercury capture
AB - Activated carbon sorbents have the potential to be an effective means of mercury
control in combustion systems. Reactions of activated carbons in flow systems
with mercury and gas stream components were investigated to determine the types
of chemical interactions that occur on the sorbent surface. The effects of carbon
type, particle size, temperature, and reactive gases were studied. Sorption
kinetics and capacities for lignite- and bituminous-based carbons were compared
with those for catalytic carbons at temperatures of 107 degrees C, 150 degrees C,
and 163 degrees C. In the air and baseline gas studies, the catalytic carbons
exhibited far better sorption than the lignite- and bituminous-derived carbons.
With the catalytic carbons, the greater sorption kinetics and capacity in an air
stream or baseline gas composition compared with nitrogen provides a clear
demonstration that O(2) is required in the gas stream for higher reactivities and
capacities. Thus, a catalytic chemisorption mechanism predominates for the
sorption of mercury at these conditions. The reaction kinetics are inversely
proportional to the temperature, indicating that a preliminary physisorption step
with mercury associating with a surface site is rate-determining. In synthetic
flue gas streams containing HCl (50 ppm), the sorption kinetics of the catalytic
carbon are slightly inferior to those of lignite-based carbon. Thus, the reaction
is dominated by a different interaction, where HCl reacts with mercury on the
carbon surface and the oxidation sites on the catalytic carbon apparently have no
advantage. Granular and fine-particle carbons gave similar results in flue gas
streams.
PMID- 10781719
TI - Control of nitric oxide, nitrous oxide, and ammonia emissions using microwave
plasmas
AB - The subject of this paper is mitigation of the undesirable side-effects of
selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR):
ammonia slip, residual NO(x), and N(2)O emissions. The use of microwave-plasma
discharge within the flue gas was explored as a potential pollution-control
method. The key issues addressed were: (1) N(2)O, NH(3), and NO removal
efficiencies; and (2) sustaining a stable plasma at atmospheric, or close to
atmospheric, pressure. In non-oxidizing atmospheres, removal efficiencies were
always close to 100% for all species. In the presence of oxygen, however,
appreciable amounts of nitric oxide and ammonia were formed. Methods leading to
preventing these undesirable effects were examined. In a number of runs, stable
plasma operation was attained at pressures close to atmospheric.
PMID- 10781720
TI - An investigation on polycyclic aromatic hydrocarbon emissions from pulverized
coal combustion systems
AB - Results from a series of tests conducted to study the emission of polynuclear or
polycyclic aromatic hydrocarbons (PAHs) from bench-scale and small industrial,
water-tube boiler are discussed. A Middle Kittanning, and Upper Freeport seam
coals were used in the study. Samples were extracted from the reactor outlet and
from the inlet and outlet sides of the research boiler's (RB) baghouse using EPA
promulgated methods.Only acenaphthene and fluoranthene were detected in down
fired combustor (DFC) samples. In addition to these two, naphthalene was detected
in the RB samples. Emission factors ranged from 80 to 320 &mgr;g/kg of fuel
fired. Although there were minor trends in the emissions' data, given the
reproducibility limits for PAH compounds, no significant differences were found
in the emissions with respect to the fuel type or form (pulverized coal (PC) vs.
coal-water slurry fuel (CWSF), and raw vs. cleaned coal) and firing conditions
(high and low excess air). The PAH emissions showed a decrease with increase in
the firing rate.A bench-scale drop-tube reactor (DTR) was used to study the
effects of temperature and residence time on PAH formation. The results revealed
near constant PAH concentrations in the solid-phase samples, while the PAH
concentrations in the vapor-phase samples increased as a function of temperature.
At a temperature of around 1300 degrees C, the rate of PAH formation was exceeded
by the rate of PAH oxidation, and PAH concentrations in the vapor phase began to
decrease.
PMID- 10781721
TI - Effect of geological processes on coal quality and utilization potential: review
with examples from western Canada.
AB - This review article compares the elemental and radionuclide concentrations in
coals from western Canada, the vast majority of which are used for power
generation in Alberta. The coals range in age from lower Cretaceous to middle
Eocene, and in rank from subbituminous to high volatile bituminous. Some of the
coals were deposited in deltaic lagoonal to marine settings while others formed
under lacustrine conditions in intermontane graben settings or in alluvial
plains. The role of source rock (provenance), depositional environment, tectonic
regime and hydrologic conditions on elemental concentration and distribution will
be discussed, with specific examples from western Canada. In addition, the effect
of natural weathering, igneous intrusion and self-burning (spontaneous
combustion) on the enrichment and/or depletion of elements will be presented. The
emphasis throughout this review article will be on the fate of elements of
environmental concern and interest (e.g. As, Ba, B, Cl, Co, Cr, Cu, Mn, Mo, Se,
Th, U, V and Zn) and of radionuclides of the U and Th series upon coal
utilization. This article is also intended for those not familiar with the
geological or environmental sciences, particularly as related to fossil fuel
utilization.
PMID- 10781723
TI - Introduction
PMID- 10781722
TI - Comparing and assessing acid rain-sensitive ponds.
AB - Changes in pH and temperature were monitored in two freshwater ponds in
Southeastern Massachusetts from 1990 to 1993 using a remote-sensing system that
collected data on a continuous basis. The sensing system included a combination
electrode, pH meter and portable computer powered by a marine battery.
Temperature and pH information from the pH meter were acquired every 10 min and
stored in the computer. The two ponds, located within 2 km of one another, have a
different average pH and sensitivity to acid precipitation. Maquan Pond has an
average pH of 6.0 and an alkalinity of 7.4 mg/l, while Furnace Pond has an
average pH of 6.9 and alkalinity of 14.9 mg/l. The pH of both ponds varied
seasonally and showed diel changes due to the photosynthetic and respiratory
activity of aquatic organisms. Precipitation events did not change the pH of
Furnace Pond. Maquan Pond on the other hand, did exhibit changes in surface water
pH due to specific acidic precipitation events. During certain rainstorms, the pH
of Maquan surface waters dropped to values as low as pH 4. In addition to the
transient changes in pH, the acid-sensitive pond also exhibited differences in
planktonic distribution patterns.
PMID- 10781724
TI - Molecular characterization of Brazilian isolates of orf virus.
AB - Outbreaks of an epidermic disease suggesting parapox virus infections have been
observed in all major herds of sheep and goats from different geographical areas
of Brazil. Clinical samples (dried scabs) were collected and orf virus was
isolated and characterized by electron microscopy in previous work. In order to
characterize these viruses at the molecular level, a modified methodology for
genomic DNA extraction directly from scabs was used and such DNA was used to
derive the restriction enzyme digestion patterns for clinical samples from three
distinct geographic origins. Pulsed field gel electrophoresis was used to
separate restriction enzyme DNA fragments and heterogeneity among isolates from
different geographic areas could be observed on stained gels. The HindIII-G DNA
fragment from orf-A virus genome was cloned and hybridized to DNA of other orf
virus isolates. Further heterogeneity was confirmed by these hybridizations.
PMID- 10781725
TI - Detection and differentiation of Leptospira spp. serovars in bovine semen by
polymerase chain reaction and restriction fragment length polymorphism.
AB - In view of the importance of venereal transmission of bovine leptospirosis, the
objective of the present study was to apply the polymerase chain reaction (PCR)
to 26 serovars of Leptospira interrogans, L. borgpetersenii, L. santarosai, L.
noguchii and L. biflexa, to determine the detection threshold in semen samples
and to evaluate the possibility of differentiation among serovars using 19
restriction endonucleases. The results showed that all serovars were amplified
and the detection threshold in semen samples of a bull was 100 bacteria/ml. Using
endonucleases we could classify the 26 serovars into eight groups. The present
results show that PCR is a method of great potential for the detection of
Leptospira spp. at bovine artificial insemination centers.
PMID- 10781726
TI - Preferential infection of neuronal and astroglia cells by Akabane virus in
primary cultures of fetal bovine brain.
AB - Akabane virus is a member of the genus Bunyavirus; it is pathogenic for ruminants
and transmitted by arthropod vectors. Infection of adult cattle and sheep causes
a transient viremia without obvious clinical signs, while infection of pregnant
animals often causes fetal abnormalities including hydranencephaly, poliomyelitis
and arthrogryposis. Infectious virus or viral antigens is present in the brain,
spinal cord and skeletal muscle of infected fetuses. To understand the
interaction between Akabane virus and bovine brain cells, we investigated the
viral tropism using primary cultures of fetal bovine brain. The cultured neuronal
cells, astroglia cells and microglia cells were distinguished by cell type
specific antisera. Akabane virus was found to infect neuronal cells and astroglia
cells, which led to degenerative death. No microglia cells were found infected.
In some brain cultures, we observed different sensitivities of the cells to two
Akabane virus strains: an attenuated strain infected and spread more readily than
wild type virus. This difference was not observed in a hamster fibroblast cell
line. Both viral and host determinants might be involved in the different
susceptibility of brain cells to Akabane virus infection.
PMID- 10781727
TI - An isolated epizootic of hemorrhagic-like fever in cats caused by a novel and
highly virulent strain of feline calicivirus.
AB - An isolated epizootic of a highly fatal feline calicivirus (FCV) infection,
manifested in its severest form by a systemic hemorrhagic-like fever, occurred
over a 1-month period among six cats owned by two different employees and a
client of a private veterinary practice. The infection may have started with an
unowned shelter kitten that was hospitalized during this same period for a severe
atypical upper respiratory infection. The causative agent was isolated from blood
and nasal swabs from two cats; the electron microscopic appearance was typical
for FCV and capsid gene sequencing showed it to be genetically similar to other
less pathogenic field strains. An identical disease syndrome was recreated in
laboratory cats through oral inoculation with tissue culture grown virus. During
the course of transmission studies in experimental cats, the agent was
inadvertently spread by caretakers to an adjoining room containing a group of
four normal adult cats. One of the four older cats was found dead and a second
was moribund within 48-72h in spite of symptomatic treatment; lesions in these
animals were similar to those of the field cats but with the added feature of
severe pancreatitis. The mortality in field cats, deliberately infected
laboratory cats, and inadvertently infected laboratory cats ranged from 33-50%.
This new isolate of calicivirus, named FCV-Ari, was neutralized at negligible to
low titer by antiserum against the universal FCV-F9 vaccine strain. Cats orally
immunized with FCV-F9, and then challenge-exposed shortly thereafter with FCV
Ari, developed a milder self-limiting form of disease, indicating partial
protection. However, all of the field cats, including the three that died, had
been previously immunized with parenteral FCV-F9 vaccine. FCV-Ari caused a
disease that was reminiscent of Rabbit Hemorrhagic Disease, a highly fatal
calicivirus infection of older rabbits.
PMID- 10781728
TI - Identification of the copper-zinc superoxide dismutase activity in Mycoplasma
hyopneumoniae.
AB - Copper-zinc superoxide dismutase (Cu/ZnSOD), a key enzyme in defense against
toxic oxygen-free radicals, is widespread in eukaryotes and several species of
gram-negative bacteria. The presence of this enzyme in Mycoplasma hyopneumoniae
(M. hyopneumoniae), the primary pathogen of mycoplasmal pneumonia in pigs, was
examined since the polyclonal antibody against bovine Cu/ZnSOD was dominantly
cross-reactive with the M. hyopneumoniae Cu/ZnSOD from whole cellular proteins.
In situ activity staining on SDS-PAGE showed that the molecular mass of M.
hyopneumoniae Cu/ZnSOD in reducing form was approximately 17kDa. The presence of
Cu and Zn ions at the active site of the enzyme was confirmed on the basis of
inhibition by KCN and by H(2)O(2). The activity of M. hyopneumoniae Cu/ZnSOD on
both SDS- and native-polyacrylamide gels was completely inhibited by 2mM KCN and
the gels showed no iron-containing SOD (FeSOD) or manganese-containing SOD
(MnSOD) in the crude extracts. The activity of M. hyopneumoniae Cu/ZnSOD in crude
extract was 70units/mg protein and was 55% inhibited by 5mM KCN and 56%
inactivated by 40mM H(2)O(2). This enzyme was growth-stage dependent and
evidenced markedly higher production during the early log phase. Different
expression levels of Cu/ZnSOD activity in field isolates were also detected.
Taken together, the presence of Cu/ZnSOD in M. hyopneumoniae was identified for
the first time.
PMID- 10781730
TI - Identification of virulence associated markers in the cell wall of pigeon
Streptococcus gallolyticus strains.
AB - The cell wall protein profiles of 56 isolates of Streptococcus gallolyticus of
differing virulence for pigeons were compared by SDS-PAGE. Additionally, Western
blot analysis was performed on the cell wall proteins of 14 strains using sera of
pigeons, experimentally infected with A(+)T1 or A(-)T2 strains of S.
gallolyticus. The profile of silver stained gels exhibited a complex array of 20
50 bands ranging from less than 6.5-210kDa. A band with molecular mass of 114kDa
was only observed in isolates that belonged to the highly virulent A(+)T1,
A(+)T2, A(+)T3 and A(-)T1 culture supernatant groups. A band with a slightly
higher molecular mass (115kDa) as well as a 207kDa band were only detected in
isolates that belonged to the moderately A(-)T3 or low A(-)T2 virulent culture
supernatant groups. The 114 and 115kDa band were recognised by all homologous and
heterologous pigeon sera used whereas the 207kDa band was only recognised by sera
of pigeons infected with a A(-)T2 strain. These findings may indicate that the
114, 115 and 207kDa bands are useful as additional virulence associated markers
for pigeon S. gallolyticus strains.
PMID- 10781729
TI - Detection of Mycoplasma synoviae in poultry environment samples by culture and
polymerase chain reaction.
AB - Successful detection of Mycoplasma synoviae (MS) by culture and PCR from samples
collected in the environment of experimentally infected chickens and turkeys, or
under field conditions, is described. Results showed that in the experimental
infection, 10/96 and 46/96 samples of food, drinking water, feathers, droppings
or dust were positive by culture and Mycoplasma-PCR. In field conditions, the
number of positive results for environmental samples were respectively 7/28 and
17/28. These observations highlight the high disseminating capacities of this
mycoplasma and show the usefulness of the PCR method for epidemiological studies.
PMID- 10781731
TI - Identification of the F17 fimbrial subunit- and adhesin-encoding (f17A and f17G)
gene variants in necrotoxigenic Escherichia coli from cattle, pigs and humans.
AB - Putative colonization factors of the F17 family of fimbrial adhesins have been
identified in necrotoxigenic Escherichia coli Type 1 and Type 2 (NTEC1 and NTEC2)
from calves, pigs, and humans. The f17A and f17G gene variants, coding
respectively for the major subunit and for the adhesin of the F17 fimbriae, were
typed in 70 E. coli carrying f17-related sequences (15 NTEC1, 51 NTEC2, and four
non-NTEC) by colony hybridisation with gene probes derived from the different
f17A gene variants (a, b, c, and d) and by PCRs specific for each f17A and f17G
(I and II) gene variants. Typing of f17A genes was not possible by colony
hybridisation, as most 70 E. coli were positive with more than one gene probe. On
the other hand, the PCRs allowed the typing of the f17A gene in 37 E. coli and of
the f17G gene in all 70 E. coli. The f17Ab gene variant was detected in 13 NTEC2;
the f17Ac, in all 15 NTEC1, six NTEC2 and two non-NTEC; and the f17Ad, in one non
NTEC. Seven additional NTEC2 were positive with the PCRs for two variants: f17Ab
and f17Ac in three of them; f17Ac and f17Ad in four of them. Either these seven
NTEC2 harbour two variants or the variant present can be detected by two PCRs.
The remaining 25 NTEC2 and one non-NTEC tested negative with the PCRs for the
four f17A gene variants, suggesting the existence of other variant(s). In
contrast, all 70 E. coli were positive with the PCR for the f17GII gene variant
and none with the PCR for the f17GI gene variant. The f17-related sequences were
present on the CNF2/Vir plasmids in 27 out of the 46 NTEC2 from which plasmid DNA
could be extracted: all but one of those positive for the f17Ab gene variant and
various proportions of those positive for other variants. In contrast, no plasmid
carried f17-related sequences in NTEC1 and non-NTEC.
PMID- 10781732
TI - A PCR assay used to study aerosol transmission of Actinobacillus pleuropneumoniae
from samples of live pigs under experimental conditions.
AB - The study describes a polymerase chain reaction (PCR) assay for the detection of
Actinobacillus pleuropneumoniae. The test is based on the amplification of the
omlA gene coding for an outer membrane protein of A. pleuropneumoniae. To test
the specificity of the reaction, 19 other bacterial species related to A.
pleuropneumoniae or isolated from pigs were assayed. They were all found negative
in the PCR assay. The detection threshold of the test was 10(2) A.
pleuropneumoniae CFU/assay. The test was then applied to the detection of A.
pleuropneumoniae from tonsillar biopsies and tracheobronchial lavage fluids of
pigs without a culture step. The detection of A. pleuropneumoniae in these
samples was performed by PCR, by conventional culture and by bacteriology with
immunomagnetic beads. The number of samples that were found positive by PCR was
almost three times higher than the number of samples from which A.
pleuropneumoniae was isolated by both bacteriological techniques. The detection
of A. pleuropneumoniae in these samples allowed us to demonstrate its aerosol
transmission to pigs under experimental conditions. The trial involved 18
specific pathogen free pigs. Six pigs, infected with A. pleuropneumoniae, were
located in a unit A, together with four non-infected animals (contact pigs).
Eight non-infected pigs (reporter pigs) were located in a unit B, adjacent to A.
We detected A. pleuropneumoniae in samples from infected animals but also from
'contact' (unit A) and 'reporter' (unit B) pigs. The results of this study show
that the simple preparation of the samples followed by the PCR assay may be a
useful tool for epidemiological studies.
PMID- 10781733
TI - Nitric oxide synthase distribution in the cat superior colliculus and co
localization with choline acetyltransferase.
AB - Nitric oxide and acetylcholine are important neuromodulators implicated in brain
plasticity and disease. We have examined the cellular and fiber localization of
nitric oxide in the cat superior colliculus (SC) and its degree of co
localization with ACh using nicotinamide adenine dinucleotide phosphate
diaphorase (NADPHd) histochemistry and an antibody to neuronal nitric oxide
synthase. ACh was localized using an antibody against choline acetyltransferase.
We also made injections of biocytin into the region of the parabrachial brainstem
to confirm that this region is a source of nitric oxide containing fibers in SC.
NADPHd labeled neurons within the superficial layers of the superior colliculus
included pyriform, vertical fusiform, and horizontal morphologies. Labeled
neurons in the intermediate gray layer were small to medium in size, and mostly
of stellate morphology. Neurons in the deepest layers had mostly vertical or
stellate morphologies. NADPHd labeled fibers formed dense patches of terminal
boutons within the intermediate gray layer and streams of fibers within the
deepest layers of SC. Choline acetyltransferase antibody labeling in adjacent
sections indicated that many fibers must contain both labels. Over 94% of neurons
in the pedunculopontine tegmental and lateral dorsal tegmental nuclei were also
labeled by both NADPHd and choline acetyltransferase. In addition, biocytin
labeled fibers from this region were localized in the NADPHd labeled patches. We
conclude that nitric oxide is contained in a variety of cell types in SC and that
both nitric oxide and ACh likely serve as co-modulators in this midbrain
structure.
PMID- 10781734
TI - Substance P-immunoreactive neurons in the rostromedian area of the midbrain send
axons to the lower spinal cord in the chicken.
AB - Substance P-immunoreactivity in neurons projecting to the spinal cord was
examined using retrograde tract-tracing method combined with immunohistochemical
techniques in chickens. Many small substance P-immunoreactive neurons were
densely clustered in the midline area in the rostral midbrain, the rostromedian
area (80% of the neurons in the rostromedian area). Some of these substance P
immunoreactive neurons in the rostromedian area (about 20% of substance P
immunoreactive neurons) were retrogradely labeled by small injections of wheat
germ agglutinin conjugated horseradish peroxidase into the central part of the
lumber segments including the intermediomedial nucleus, suggesting the
projections from the rostromedian area to the lower spinal preganglionic regions.
From the present data and mammalian previous studies, it was suggested that the
midline area in the midbrain has fiber connections with the regions related
autonomic functions, and all of which exhibit substance P-immunoreactivity.
PMID- 10781735
TI - Temporal, regional, and cell-specific changes of iNOS expression after
intrastriatal microinjection of interferon gamma and bacterial
lipopolysaccharide.
AB - Here we study expression of the inducible isoform of nitric oxide synthases after
intrastriatal microinjection of interferon-gamma and bacterial lipopolysaccharide
in the rat at different time points to detect time- and localisation-dependent
changes of iNOS expression. Three different areas in the striatum and the corpus
callosum were evaluated. Antibodies against the glial fibrillary acidic protein
and the microglia/brain macrophage epitope ED1 were used to detect colocalization
of inducible nitric oxide synthase with astrocytes or activated microglia/brain
macrophages, respectively. Inducible nitric oxide synthase-positive cells
occurred first in intravascular and perivascular cells at 4 h. Perivascular and
parenchymal inducible nitric oxide synthase expression increased up to 24 h in
the striatum, whereas in the corpus callosum inducible nitric oxide synthase
expression was maximal after 16 h. Inducible nitric oxide synthase was still
present in perivascular cells 7 days after immunostimulation. At all time points,
inducible nitric oxide synthase was predominantly detected in ED1-positive
microglia/brain. Nitrotyrosine immunohistochemistry was performed to detect NO
mediated nitration of proteins at all time points. Nitrotyrosine-positive neurons
and microglial cells were detected from 24 h until 7 days after immunostimulation
and were absent in controls. Detailed knowledge of the changes in the time course
and cellular source of inducible nitric oxide synthase expression following brain
immunostimulation provide a basis for establishing treatment strategies and
windows of therapeutic intervention during neuroinflammation.
PMID- 10781736
TI - Immunocytochemical mapping of endomorphin-2-immunoreactivity in rat brain.
AB - Endomorphin-2 (Tyr-Pro-Phe-Phe-NH(2)) is a novel endogenous opioid with high
affinity and selectivity for the mu-opioid receptor. Immunocytochemical studies
have located this peptide in spinal cord, brainstem and selected brain regions.
However, there are disagreements regarding its distribution between published
reports. Furthermore, the distributions reported for the endomorphins resemble
that of neuropeptide FF, suggesting that some of the previous findings might be
due to cross-reactivity with the latter substance. In the present study, the
distribution of endomorphin-2-immunoreactivity (ir) was examined throughout the
entire rat brain using an affinity-purified antiserum that appeared not to cross
react with neuropeptide FF. Endomorphin-2-ir cell somata were most prominent in
the hypothalamus and the nucleus of the solitary tract (NTS). Endomorphin-2-ir
varicose fibers were observed in such areas as the bed nucleus of the stria
terminalis, the septal nuclei, the periaqueductal gray, the locus coeruleus, the
lateral parabrachial nucleus, the NTS, and the substantia gelatinosa of the
medulla. More modest immunoreactivity was seen in substantia nigra, nucleus raphe
magnus, the ventral tegmental area, the pontine nuclei and the amygdala. Fibers
were also observed in the ventral cerebellum. Of note was the negligible
immunoreactivity in the striatum, a region known to express high levels of mu
opioid receptors. Thus, endomorphin-2-ir was widely, but not uniformly,
distributed throughout the central nervous system and was associated largely, but
not exclusively, with regions expressing mu-opioid receptors. Based on its
distribution, it may have a role in the control of neuroendocrine, cardiovascular
and respiratory functions, and mood, feeding, sexual behavior and pain.
PMID- 10781737
TI - Ontogenic profile of the expression of the mu opioid receptor gene in the rat
telencephalon and diencephalon: an in situ hybridization study.
AB - The developmental profile of mu (mu) opioid receptor gene expression has been
characterized in the embryonic, postnatal and adult rat brain by in situ
hybridization histochemistry. By ED12, mu opioid receptor mRNA was detectable in
the deep neuroepithelium of the cortical plate. In the developing rat central
nervous system (ED13-PD40), transcripts were seen over numerous telencephalic and
diencephalic structures, such as the olfactory bulb, caudate-putamen, nucleus
accumbens, amygdaloid complex, hippocampal formation, hypothalamus and thalamus.
In the vast majority of brain regions examined, the developmental profile of the
mu opioid receptor gene expression is similar to that of its translated protein
as established using receptor autoradiography. Once a hybridization signal is
detected in the prenatal period, it gradually increased to reach maximal levels
during the second and third postnatal weeks. By the end of the third postnatal
week, mu opioid receptor mRNA levels decreased to reach amounts seen in
adulthood. Our study demonstrates that mu opioid receptor gene expression is seen
very early on in the embryonic rat brain with transient increases observed during
the critical period of neurogenesis, neuronal migration and synaptogenesis,
suggesting a role of this opioid receptor subtype in brain developmental
processes.
PMID- 10781738
TI - Frequency of the prolificacy gene in flocks of Indonesian thin tail sheep: a
review.
AB - Indonesian thin tail (ITT) sheep have a major prolificacy gene (FecJ(F)), the
frequency of which is higher in the new born lambs, than in the remainder of the
flock when mating is random, because carrier ewes produce more progeny than do
non carriers. The frequency of the gene may vary between flocks, but remains
relatively stable in flocks with established husbandry procedures. The
countermanding selection pressures maintaining the equilibrium value for the
frequency of FecJ(F) are mainly those deriving from higher mortality rates of
lambs in larger litters. Embryo survival is not significantly different across
the range of ovulation rates in ITT ewes, in contrast to observations in other
prolific breeds. Generation intervals and the incidences of metabolic and
infectious diseases in ewes carrying larger litters can also affect the frequency
of FecJ(F) in flocks. In turn, each of the factors affecting the frequency of
FecJ(F) is modulated by the level of nutrition and management in each flock. The
distribution of prolificacy genotypes in the ewes of a standard flock is
calculated as FecJ(F)FecJ(F)/12; FecJ(F)FecJ(+)/44; FecJ(+)FecJ(+)/44 giving a
frequency of 0.34 for FecJ(F). The frequency of FecJ(F) is then 0.43 in the lambs
at birth, when their numbers have been amplified in the carrier ewes. There are
heavier metabolic demands on ewes carrying larger litters and the foetuses
constitute a higher proportion of weight gain during pregnancy. Consequently,
more of the lambs of carrier ewes are smaller and weaker at birth, and the
reserves of the ewes for colostrum and milk production are depleted. When low
lamb survival rates in larger litters are considered, the frequency of FecJ(F)
falls to 0.35 in the lambs at weaning in lean years and 0.38 in middling years.
At a high level of husbandry, ewe weight gains during pregnancy and lamb survival
rates improve substantially, and after 3 years, the frequency of FecJ(F) in the
lambs at birth is estimated to have risen to 0.49; and 0.47 at weaning.
PMID- 10781739
TI - Reproductive characteristics of Ethiopian highland sheep. I. Genetic parameters
of testicular measurements in ram lambs and relationship with age at puberty in
ewe lambs.
AB - A study was conducted to estimate heritabilities of, and genetic correlations
among, body weight (WT) and testicular measurements - scrotal circumference (SC),
testicular diameter (TD), testicular length (TL) and epididymal diameter (ED) -
in ram lambs between 6, 9 and 12 months old, and relationship of the testicular
traits with age at puberty in ewe lambs (AP). Two fat-tailed sheep breeds, the
Horro and Menz, indigenous to the Ethiopian highlands were studied. Experimental
lambs were produced by mating 250 oestrus-synchronized ewes of each breed to 10
sires in a single-sire mating system over three mating periods which produced,
for this study, a total of 361 ram lambs and 148 ewe lambs, with substantial
pedigree information, in two dry seasons (October/November 1992 and 1993) and one
wet season (June/July 1993). Mean AP was 322.7 days. Breed was not significant
(P0.05) for all testicular measurements, except ED at 9 months for which the
Horro had a higher (P<0.01) value (20.6, s.e. 0.38 versus 19.3 s.e. 0.30). Horro
ewe lambs had their first oestrus 28 days earlier (P<0.05) than the Menz.
Heritability estimates were obtained from a sire model (M1) and from an
individual animal model with additive direct and maternal effects (M2). The
maternal effect was not fitted in M2 for AP. Repeatability and heritability
estimates were also obtained by analysing records at the three ages in a repeated
measures model (M3). M1 and M2 heritability estimates were generally low to
moderate but were associated with large standard errors. Heritability estimates
for testicular measurements were generally similar to those for WT. Among the
testicular measurements, SC had the highest heritability estimates at 6 (0.45,
s.e. 0.24 for M1) and at 12 months (0.41, s.e. 0.21 and 0.41, s.e. 0.20 for M1
and M2, respectively). Model 3 heritability estimates were 0.29 (s.e. 0.14), 0.24
(s.e. 0.12), 0.09 (s.e. 0.07), 0.11 (s.e. 0.08) and 0.12 (s.e. 0.08) for WT, SC,
TD, TL and ED, respectively. Only repeatability estimates for WT (0.34, s.e.
0.02) and SC (0.25, s.e. 0.03) were significant. Heritability of AP was estimated
at 0.16 (s.e. 0.21) by M1 and 0.14 (s.e. 0.19) by M2. Genetic correlations of AP
with testicular measurements, especially with SC (-0.57, s.e. 0.38 and -0.78,
s.e. 0.33, at 9 and 12 months, respectively) and TD (-0.72, s.e. 0.33 and -0.83,
s.e. 0.48), were desirable and generally high. Adjustment of testicular
measurements for liveweight consistently resulted in a reduction in estimates of
heritability and genetic correlations. SC was suggested as the most appropriate
selection candidate for the genetic improvement of both male and female
reproductive performance in these breeds.
PMID- 10781740
TI - Clinical, cardiopulmonary, hematological and serum biochemical effects of
sevoflurane and isoflurane anesthesia in oxygen under spontaneous breathing in
sheep.
AB - Effects of sevoflurane and isoflurane anesthesia in oxygen on clinical,
cardiopulmonary, hematological, and serum biochemical findings were compared in
sheep breathing spontaneously undergoing minor surgical operations during short
term (60-80min) or long-term (3-4h) anesthesia. All sheep were premedicated with
atropine sulfate (0.1mg/kg) intramuscularly, and 10min later, induced to
anesthesia by intravenous infusion of sodium thiopental (mean 14.1+/-3.4 S.D.
mg/kg). After intubation, they were anesthetized with either isoflurane or
sevoflurane in oxygen at a total gas flow rate of 1.5l/min. The results revealed
that recovery time with sevoflurane was more rapid than with isoflurane.
Respiration rates, tidal volume, minute ventilation and heart rates during
sevoflurane anesthesia were similar to those during isoflurane anesthesia. The
degree of respiratory acidosis during sevoflurane anesthesia was also similar to
that during isoflurane anesthesia. There were no significant differences between
sevoflurane and isoflurane anesthesia in hematological and serum biochemical
values.
PMID- 10781741
TI - Metabolizable energy of roughage in Taiwan.
AB - The fixed metabolizable energy (ME) values from the NRC do not represent the true
ME values of the various feedstuff used in livestock rations. Therefore, a rapid
and effective method for evaluating the ME value of forage crops is required for
proper ration formulation to improve production efficiency. Dairy goat digestion
trials were conducted as the in vivo reference using the method of Menke and
Steingass (1988) [Menke, K.H., Steingass, H., 1988. Feed Sci. Technol. 28, 91-97]
which derived the amount of gas produced from in vitro fermentation. This method
was adapted in this study to evaluate the ME value. In the goat digestion trial,
six dairy goats were used for each roughage sample in a total fecal collection
trial to determine the digestible nutrients, including energy (DE) and total
digestible nutrient (TDN). The in vivo ME value was calculated using the method
of Shiemann et al. (1971) [Shiemann, R., Nehring, K., Hoffmann, L., Jentsch, W.,
Chudy, A., 1971. Energetische Futterbewertung und Energienormen. VEB Deutscher
Land-wirtschaftsverlag, Berlin, p. 75. (in German)] (ME(1)
(MJ/kg)=5.2DCP+34.2DEE+12.8DCF+15.9DNFE, g/g). The in vitro ME value was then
estimated from the chemical composition of the feed and amount of gas produced
(G(b)) from in vitro fermentation. The value calculated from both with (ME(3))
and without (ME(2)) the inclusion of nitrogen free extracts (NFE) in the
prediction equation. (ME(2) (MJ/kg)=0.145G(b)+4.12CP+6.5CP(2)+20.6EE+1.54, g/g;
ME(3) (MJ/kg)=0.118G(b)+8.75CP+19.21EE+3.38NFE+0.691, g/g). The 12 roughage
samples consisted different growth stages of Napier grass Taishi No. 2: (day of
harvest; 40, 50, 60 and 65), dwarf Napier grass Taishi No. 1: (Day 40 and 65) and
Pangola grass (Day 45) hay (Day 70), corn silage, imported alfalfa hay, timothy
hay and Bermuda hay. The correlation between the ME values calculated from in
vivo and in vitro without NFE was lower than with NFE inclusion in the equation.
A higher correlation between the ME values calculated from in vivo and in vitro
without NFE inclusion than with NFE inclusion in the prediction equation was
obtained when alfalfa and corn silage were not included. This indicated that the
ME value of forage could be estimated rapidly using this in vitro gas method
adapted from Menke and Steingass (1988) [Menke, K.H., Steingass, H., 1988. Feed
Sci. Technol. 28, 91-97] for practical applications in ration formulation.
PMID- 10781742
TI - Dry matter intake, apparent digestibility and excretion of purine derivatives in
sheep fed tropical legume hay.
AB - Four ruminally cannulated wethers (31+/-1.3kg) were used in an experiment with a
4x4 Latin square design to estimate the DM intake, apparent digestibility,
nitrogen balance, rumen ammonia and microbial protein production. The sheep had
ad libitum access to either Cassia rotundifolia (Cassia), Lablab purpureus
(Lablab), Macroptilium atropurpureum (Siratro) or Stylosanthes guianensis
(Stylo). Dry matter intake of cassia was lower (P<0.001) than that of lablab,
siratro and stylo hays. Organic matter intake was greater (P<0.001) for lablab,
siratro and stylo hays than that of cassia. Dry matter digestibility was higher
(P<0.05) for lablab hay, than that of cassia, siratro and stylo hays. The organic
matter digestibility ranged from 0.579 for cassia hay to 0.617 for stylo hay and
there were no differences (P0.05) among the legume hays. Nitrogen intake was
highest (P<0.05) in sheep given stylo hay and least in sheep fed cassia hay.
Animals given lablab, siratro and stylo hays had higher (P<0.05) faecal and
urinary N compared to those on cassia hay. Rumen ammonia N concentration was
highest (P<0.05) in sheep given lablab while sheep offered siratro and stylo had
intermediate values, and least in animals fed cassia hay. The ammonia levels were
above the recommended optimal level of 50mg N/l. The total purine derivative
excretion in the urine and microbial N supply was not different (P0.05) among
treatments. From the presented findings it is concluded that the intake and
digestibility in sheep of the four legume hays are variable and provide adequate
rumen ammonia N for maximum rumen microbial growth making then ideal protein
supplements to ruminants fed low quality roughages.
PMID- 10781743
TI - Effect of buck stimulus on mature and pre-pubertal norgestomet-treated goats.
AB - Two experiments were conducted to assess the effect of buck exposure to
synchronize estrus in mature and pre-pubertal norgestomet-treated crossbred
(criolloxdairy breeds) goats. In experiment 1, 100 mature goats (25 per group)
under range conditions were either teased at 48 or 24h before Sincromate-B (SMB;
9 days treatment of 2mg norgestomet) implant withdrawal. A third group was
exposed to bucks 1 day after SMB treatment and another group was only exposed to
bucks (control). Does exposed to bucks 1 day after SMB treatment tended to have a
lower percentage of estrus (70% compared to 80% and 92% in other groups) and
lower pregnancy rate (57.9 compared to 78.3 and 82.6 in other groups). At 156
days post-joining a significant (P<0.05) difference in cumulative kidding
percentage was found between does teased 48h before implant removal (88.9%) and
does teased 24h before implant removal (56.3%). Teasing without norgestomet was
completely effective at stimulating estrus activity. In experiment 2, pre
pubertal does (n=36; mean 16.6kg BW) treated with SMB+PMSG+teasing tended to have
a higher estrus response than SMB+PMSG treated female goat kids (91.6% vs. 66.6%;
P=0.13). The results of this study indicate that, during the transitional period,
the male effect was as effective as the synchronizing treatments involving SMB in
inducing estrus in goats with reduced seasonal inhibition of reproduction. Also,
buck exposure potentiates the effect of PMSG to induce estrus in norgestomet
primed pre-pubertal does.
PMID- 10781744
TI - The effect of breed slaughter weight and nutritional management on cholesterol
content of lamb carcasses.
AB - This study was carried out to assess the effect of breed, sex, post-weaning
nutrition, live weight at slaughter and their interactions on the cholesterol
content in carcass fat of lambs. The carcasses were obtained from lambs of three
indigenous Greek dairy breeds of sheep, the Boutsko (B), Serres (S) and
Karagouniko (K) breed. After weaning (at approximately 42 days), the lambs of the
three breeds had been reared under different conditions of housing and
nutritional management in three consecutive experiments between 1992 and 1994. In
experiment 1, lambs (males and females) were individually penned and fed ad
libitum on a concentrate ration (11.3MJ Metabolizable Energy (ME)/kg DM and 192g
crude protein (CP)/kg DM) together with 100g per day of Lucerne hay (8.3MJ ME/kg
DM and 182g CP/kg DM). In experiment 2, lambs (males only) were also individually
penned but were fed on three different levels of concentrate and ad libitum on
Lucerne hay. In experiment 3, lambs (males only) were initially group fed indoors
for 63 days on three different levels of concentrate together with ad libitum
Lucerne hay, and thereafter the lambs finished on irrigated, sown pasture (Lolium
perrene+Trifolium repens). Lambs were assigned to be slaughtered at one of five
standard proportions of estimated mature weight for each breed in experiment 1;
at three fixed live weights, common for all breeds in experiment 2 and at two
fixed proportions of breed mature weight in experiment 3. The right-hand side of
the lamb carcasses was minced and 150 lamb carcasses were selected out of a total
of 300 minced carcasses. The concentration of total cholesterol content in
carcass fat was determined by HPLC in samples of these 150 lamb carcasses. Mean
cholesterol content of carcass fat in the three breeds, B, S and K, extracted
from the whole ground carcasses samples, was 3.33, 4.41, 3.34mg/g of carcass fat
(s.e.d. 0.18), respectively in experiment 1, whereas this content was 3.42, 4.50,
3.59mg/g of carcass fat (s.e.d. 0.19) in experiment 2 and 4.38, 3.47, 3.78mg/g of
carcass fat (s.e.d. 0.22) in experiment 3. Cholesterol content differed
significantly (P<0.001 in experiments 1 and 2, P<0.05 in experiment 3) between
breeds. It was also significantly affected (P<0.05) by the sex of lambs
(experiment 1). Live weight of lambs at slaughter had a significant effect on
cholesterol content (P<0.001 in experiment 1 and P<0.05 in experiment 2). There
was a general trend for cholesterol content to be lower in fat samples extracted
from carcasses as target slaughter weight increased. The different levels of
concentrate feed affected significantly (P<0.00l) the cholesterol content in
carcass fat in experiment 2. The results suggest that there are possibilities of
modifying body composition by manipulation of post-weaning nutrition, especially
reducing the cholesterol content, in carcass fat of lambs slaughtered at a wide
range of live weights. In such a situation, however, as nutritional management
and degree of maturity change, breed remains the main factor that determines the
cholesterol content in carcass fat.
PMID- 10781745
TI - Variation of mohair quality over the body in Angora goats.
AB - Forty female Angora goats were selected at random from the experimental nucleus
of the National Institute of Agricultural Technology (Pilcaniyeu, Argentina),
with the aim of analyzing the variability of main fleece characteristics of the
Angora goats and establishing an optimum sampling site. Samples were taken at the
first and second shearings (12 and 18 months of age) from the following parts of
the fleece: neck, midrib, back, britch, belly and shoulder. For each sample the
following determinations were made: oven-dry yield (YLD); average (AFD); standard
deviation (SDAFD) and coefficient of variation (CVAFD) of fiber diameter;
percentage of medullated fibers (MFT); characterization of three types of
medullated fibers: continuous (MFC), interrupted (MFD) and kemp (KEMP) by
estimating their proportion, average fiber diameter, standard deviation and
coefficient of variation of fiber diameter; wax (WAX); suint (SUINT); humidity
(HMD); staple length (STAPLE); degree of brightness (Y) and degree of yellowness
(Y-Z). All variables studied showed statistically significant variability among
to the sampling position (P<0.05), except of Y-Z, proportion of FMC, average
fiber diameter of MFD and KEMP, and standard deviation of fiber diameter of KEMP
at 12 months of age, at 18 months old for STAPLE and standard deviation of fiber
diameter of MFD, and for CVAFD at the two ages of shearing (P0.05). The results
showed that sampling from the midrib of Angora goats gave adequate representation
for most of the fleece variables analyzed.
PMID- 10781746
TI - Immunology and immunotherapy of human cancer: present concepts and clinical
developments.
AB - Immunotherapy of cancer is entering into a new phase of active investigation both
at the pre-clinical and clinical level. This is due to the exciting developments
in basic immunology and tumour biology that have allowed a tremendous increase in
our understanding of mechanisms of interactions between the immune system and
tumour cells. This review briefly summarizes the state of the art in basic tumour
immunology before discussing the clinical applications of the new concepts in the
clinical setting. Clinical approaches are diverse but can now be based on strong
scientific rationales. The analysis of the available clinical results suggests
that, despite some disappointments, there is room for optimism that both active
immunotherapy (vaccination) and adoptive immunotherapy may soon become part of
the therapeutic arsenal to combat cancer in a more efficient way.
PMID- 10781747
TI - Epstein-barr virus-associated malignancies: epidemiologic patterns and etiologic
implications.
AB - Epstein-Barr virus (EBV), a ubiquitous B-lymphotrophic herpesvirus, has been
found in the tumor cells of a heterogeneous group of malignancies (Burkitt's
lymphoma, lymphomas associated with immunosuppression, other non-Hodgkin's
lymphomas, Hodgkin's disease, nasopharyngeal carcinoma, gastric adenocarcinoma,
lymphoepithelioma-like carcinomas, and immunodeficiency-related leiomyosarcoma).
As the epidemiologic characteristics of these cancers have not been considered
together, this review seeks to relate their incidence patterns and risk factors
to EBV biology and virus-host interaction in an attempt to help elucidate factors
involved in EBV-related carcinogenesis. We include a brief review of EBV virology
and primary infection to provide a biologic context for considering the
epidemiology, summarize the most salient epidemiologic features of each
malignancy, synthesize epidemiologic data by risk factor to uncover commonalities
and informative contrasts across the diseases, and propose hypotheses regarding
etiologic mechanisms, based on the possible effect of the risk factors at various
stages in the viral life cycle.
PMID- 10781748
TI - Aspergillosis in bone marrow transplant recipients.
AB - Invasive aspergillosis in bone marrow transplant recipient is associated with a
high mortality. Diagnosis is often delayed because the inflammatory response is
blunted by immunosuppression. The gold standard of tissue biopsy is often
considered too in invasive as the procedure is often complicated by bleeding and
secondary infection. Recent finding on non-invasive tests such as serial
measurement of peripheral blood galactomannan antigen or DNA appears to be
promising. However, the limited availability of such tests and requirement for
expertise are still hampering their use in routine clinical management. More
often than not, initiation of antifungal therapy is empirical and based on
suggestive radiological changes. Amphotericin B remains the gold standard of
therapy but liposconal preparation may prove to be less nephrotoxic and equally
effective. Treatment outcome depends more on the acceleration of the recovery of
the immune system and the reduction of anti-GVHD therapy than the antifungal
agent followed by surgical resection. The efficacy of many reported anti
aspergillosis prophylactic regimen has not been proved in randomized control
trials. Despite the absence of data, such policy should still be considered in
transplant units with high incidence of aspergillus or undergoing renovation.
PMID- 10781749
TI - Mental neuropathy: report of five cases and review of the literature.
AB - Mental nerve neuropathy, also referred to as numb chin syndrome, is a rare,
seemingly harmless symptom. It is more often associated with cancer, either as
first symptom or during the outcome, than with benign diseases. In this review,
we will focus on the numb chin syndrome presenting as an isolated neurological
symptom. We report five patients with mental nerve neuropathy associated with
metastatic disease (small cell lung cancer, prostatic cancer and breast cancer).
In one patient, numb chin syndrome preceded the discovery of the disease, while,
in the four others, it occurred as a sign of relapse or progression. Isolated
mental nerve neuropathy, frequently associated with breast cancer and
lymphoproliferative diseases, is generally thought to be the consequence of bone
metastases or leptomeningeal seeding, but may also present without an obvious
cause, most often secondary to the involvement of the mental nerve itself.
Although various therapies may lead to the resolution of this symptom, median
survival after diagnosis is generally less than 1 year. The appearance of a
mental nerve neuropathy should never be considered as a 'banal' symptom and
investigations to detect a possible cancer should be mandatory.
PMID- 10781750
TI - Patterns of atherosclerosis: effect of risk factors on recurrence and survival
analysis of 11,890 cases with more than 25-year follow-up.
AB - A series of 11,890 patients from the senior investigator's surgical service
between 1949 and 1998 is analyzed for the significance of distinct risk factors
for recurrence of, and survival from, atherosclerotic occlusive disease. Eight
risk factors have been assessed for their importance in 4 defined arterial
categories (the coronary arterial bed, the branches of the aorta, the abdominal
visceral [celiac, superior mesenteric, and renal] arteries, and the terminal
abdominal aorta and its major branches) in determining survival rate of the
entire group and their impact on rate of recurrence of atherosclerosis in a
subgroup of 5,568 patients who had > or =1 postoperative arteriogram, permitting
precise identification of changes in the atherosclerotic process. Patients in
these 2 groups were followed for > or =25 years; univariate and multivariate
analyses were used. On admission all patients had symptomatic atherosclerotic
occlusive disease in a single vascular category. Each patient was treated
surgically for alleviation of the disease. Two primary outcomes are included: (1)
survival, by atherosclerosis category, in all 11,890 patients; and (2)
recurrence, also by category, in the subset of 5,568 patients. Multivariate
results for recurrence showed little consistency across categories. Only 1 risk
factor, diabetes, appeared in 2 of the 3 categories fully analyzed. Other
variables that are significant in only a single category are male sex,
cholesterol, hypertension, and smoking. Survival showed much greater consistency,
with age, diabetes, and hypertension significant in all 3 categories, male sex
and smoking in 2, and cholesterol in only Category I. Univariate results followed
much the same trend. For recurrence and survival, the response of the arterial
bed to the risk factors in each of the 4 categories is distinctly different, an
observation that we have not found to be previously reported.
PMID- 10781751
TI - Increased platelet aggregability in response to shear stress in acute myocardial
infarction and its inhibition by combined therapy with aspirin and cilostazol
after coronary intervention.
AB - Although antiplatelet therapy with a specific inhibitor of phosphodiesterase-3
cilostazol improves stent patency compared with use of aspirin (ASA) alone, the
specific role of cilostazol on platelet aggregation in patients with acute
myocardial infarction (AMI) is less well understood. Thirty-six patients with AMI
who were successfully treated with primary angioplasty were randomized to 3
antiplatelet regimens: ASA alone (n = 12), ASA + ticlopidine (n = 12), and ASA +
cilostazol (n = 12). We measured shear stress-induced platelet aggregation (SIPA)
using a modified cone-plate viscometer on admission and on day 7, and evaluated
the inhibitory effects of combination therapy with ASA + cilostazol on SIPA.
Compared with cases of stable coronary artery disease, significant increases in
SIPA and plasma von Willebrand factor activity were observed in patients with AMI
before they received antiplatelet therapy. On day 7 after primary angioplasty,
ASA did not inhibit SIPA (65 +/- 15% vs 57 +/- 11%, p = 0.086), whereas both
combination therapies of ASA + ticlopidine and ASA + cilostazol significantly
inhibited SIPA in patients with AMI (ASA + ticlopidine: 61 +/- 15% vs 45 +/- 13%,
p <0. 0001; ASA + cilostazol: 64 +/- 14% vs 43 +/- 9%, p <0.005). There was a
significant correlation of SIPA with adenosine diphosphate (ADP)-induced platelet
aggregation (r = 0.412, p = 0.003) and with plasma von Willebrand factor activity
(r = 0.461, p = 0.0008). These data suggest that patients with AMI have increased
platelet aggregability in response to high shear stress. Combined antiplatelet
therapy with ASA + cilostazol appears to be as effective as therapy with ASA +
ticlopidine for reducing SIPA in patients with AMI who are undergoing primary
angioplasty.
PMID- 10781752
TI - The benefit of abciximab in percutaneous coronary revascularization is not device
specific.
AB - Abciximab has been shown to decrease adverse outcomes after percutaneous coronary
interventions, but it is unclear whether this beneficial effect is more or less
pronounced with specific devices. This study sought to determine the relative
magnitude of the benefit of abciximab among different interventional devices.
Data from the 5 placebo-controlled trials of abciximab during coronary
intervention were pooled. Patients were divided into groups based on whether they
received balloon angioplasty alone, elective stenting, bailout stenting, or
directional coronary atherectomy. In the patients undergoing balloon angioplasty,
the 30-day hazard ratio for death or myocardial infarction (MI) in the group
randomized to abciximab versus the placebo-treated group was 0.52 (p <0.001), for
elective stenting the hazard ratio was 0.51 (p <0.001), for bailout stenting the
hazard ratio was 0.38 (p <0.001), and for directional coronary atherectomy the
hazard ratio was 0.38 (p = 0.007). A Cox proportional-hazards model revealed that
overall, the use of abciximab decreased the composite end point of 30-day death
or MI rates (hazard ratio 0.55, 95% confidence interval 0.43 to 0.69, p <0. 001).
However, bailout stenting and directional coronary atherectomy were associated
with increased rates of death or MI compared with balloon angioplasty, as was
elective stenting in women compared with men. There was no significant increase
in major bleeding episodes associated with abciximab in any of the device
categories. These findings from all the controlled coronary revascularization
trials using abciximab demonstrate that a decrease in death and MI is achieved
with abciximab regardless of the type of device used, without an increase in
significant bleeding complications.
PMID- 10781753
TI - Long-term outcome in patients treated by intracoronary stenting with ticlopidine
and aspirin, and deleterious prognostic role of unstable angina pectoris.
AB - Compared with stable clinical conditions, unstable angina carries an increased
risk of immediate and delayed cardiac adverse events after balloon coronary
angioplasty. The influence of stent use in reducing these differences remains
unknown. We analyzed the early (30 days) and late outcome of a cohort of 459
consecutive patients who underwent stent placement with ticlopidine and aspirin
as antithrombotic regimen according to the presence (group 1, n = 151) or absence
(group 2, n = 308) of unstable angina at rest (Braunwald classes II and III).
Group 1 patients were older and more likely to be current or former smokers. In
group 2, prior myocardial infarction was more frequent. Procedural, in-hospital
results, and early outcome were similar in the 2 groups. However, over the long
term, the incidence of myocardial infarction (11% vs 6%, p <0.04), target lesion
revascularization (19% vs 13%, p <0.04), or any revascularization (30% vs 20%, p
<0.01) was significantly higher in group 1. Kaplan-Meier probabilities of
survival without myocardial infarction (85% vs 91%, p <0.05), survival without
revascularization of the target lesion (73% vs 83%, p <0.01), survival without
any revascularization (65% vs 77%, p <0.006), and survival without any events
(61% vs 73%, p <0.009) were significantly worse in group 1. In addition, Cox
multivariate analysis showed that unstable angina at rest was an independent
predictor of target lesion revascularization, of survival without any
revascularization, and without any events. Thus, unstable angina at rest remains
an adverse prognostic indicator in patients treated with intracoronary stents,
particularly with regard to subsequent requirement of revascularization
procedures and event-free survival.
PMID- 10781754
TI - Impaired forearm reactive hyperemia is related to late restenosis after coronary
stenting.
AB - To investigate whether systemic endothelial function on forearm resistance
vessels is related to angiographic restenosis after coronary stenting, 47 men who
underwent elective coronary stenting were divided into 2 groups according to the
presence (n = 20) or absence (n = 27) of in-stent restenosis 6 months after the
procedure. Another 19 risk factor-matched men with normal coronary angiograms
served as the control group. Forearm blood flow was assessed by venous occlusive
plethysmography. Basal forearm blood flow was similar between restenosis,
nonrestenosis, and control groups (2.63 +/- 0.19, 2.58 +/- 0.14, and 3.23 +/-
0.13 ml/100 ml forearm tissue per minute, respectively). In all 3 groups, forearm
blood flow increased significantly during reactive hyperemia (5.75 +/- 0.7, 11.
32 +/- 1.23, and 14.52 +/- 1.36 ml/100 ml forearm tissue per minute, p <0.05,
respectively) and remained unchanged after sublingual administration of
nitroglycerin. The percentage change of forearm blood flow during reactive
hyperemia was significantly lower in the restenosis group (117.3 +/- 18.3%) than
in the nonrestenosis group (354.2 +/- 46.5%, p <0.01). This difference was still
present after sublingual nitroglycerin (37.6 +/- 21.2% vs 226.4 +/- 40.5%, p <0.
01). In contrast, percentage change of hyperemic forearm blood flow was
significantly lower in patients with angina (117.5 +/- 49.5%) than in those
without angina (290.1 +/- 37.4%, p <0.05) at follow-up. In all patients, the
angiographic loss index was correlated negatively to the percentage change of
hyperemic forearm blood flow (r = -0.33, p <0.01) and positively to the
percentage change of forearm vascular resistance during reactive hyperemia (r =
0.33, p <0.01). In patients with angiographic restenosis after coronary stenting,
forearm reactive hyperemia was more impaired compared with those without
angiographic restenosis. Systemic endothelial dysfunction might be either a
marker or one of the confounding factors in the development of late restenosis
after coronary stenting.
PMID- 10781755
TI - Prognostic value of cardiac troponin-I levels following catheter-based coronary
interventions.
AB - This study has examined the prognostic significance of troponin-I (Tn-I) levels
after catheter-based coronary interventions in coronary arteries and saphenous
vein grafts lesions. Tn-I and creatine kinase-MB (CK-MB) fraction levels were
measured at 6 and 18 to 24 hours after catheter-based coronary intervention in
1,129 consecutive patients with normal preintervention plasma levels of Tn-I, and
CK-MB levels below the cutoff for myocardial infarction. Patients were stratified
according to maximal postangioplasty Tn-I levels. Group I (n = 784) had no
elevated Tn-I (<0.15 ng/ml), group II (n = 170) had Tn-I at 0.15 to 0.45 ng/ml,
and group III (n = 175) had Tn-I elevation >0.45 ng/ml. Major in-hospital
complications (death, 0-wave infarction, and emergent coronary bypass grafting)
and out-of-hospital intermediate-term (8 months) outcomes were compared between
the 3 groups. Tn-I elevation >0.45 ng/ml was associated with increased risk of
mortality (group III, 1.6%; group II, 0.6%; and group I, 0.1%; p = 0.019) and
major in-hospital complications (3.2%, 1.7%, and 0.5%; p = 0.004). There was no
difference in death (1.8%, 3.2%, and 2.4%; p = 0.74), Q-wave infarction (0.6%,
0%, and 0.3%; p = 0.66), or target lesion revascularization (10.1%, 9.0%, and
9.3%; p = 0.86) between the 3 groups at follow-up. Cardiac event-free survival
was similar between groups (p = 0.3). By multivariate analysis, Tn-I >0.45 ng/ml
was an independent predictor for major in-hospital complications (odds ratio 2.1,
95% confidence interval 1.2 to 3.9, p = 0.01). The degree of risk was also
associated with the conjoint elevation of Tn-I and CK-MB levels (odds ratio 1.1,
95% confidence interval 1.02 to 1.2, p = 0.01). We conclude that Tn-I levels >3
times the normal limit and conjoint elevation of Tn-I and CK-MB levels after
coronary angioplasty are associated with increased risk of major in-hospital
complications, but have no incremental risk of adverse intermediate-term (8
months) clinical outcomes.
PMID- 10781757
TI - Angiotensin-converting enzyme and apolipoprotein B polymorphisms in coronary
artery disease.
AB - The association between angiotensin-converting enzyme (ACE) as well as
apolipoprotein B polymorphisms and dyslipidemia and coronary artery disease (CAD)
is controversial. We assessed the distribution of ACE insertion and/or deletion,
apolipoprotein B signal peptide insertion and/or deletion, and apolipoprotein B
XbaI restriction fragment length polymorphisms in 388 nondiabetic patients. We
studied 112 patients with angiographically defined asymptomatic CAD or with
stable functional classes I and II angina and 139 patients with acute myocardial
infarction who were age matched to 137 control subjects. Univariate analysis
showed higher prevalence of Xba50% reduction of lumen diameter. Overall,
multivariable regression disclosed traditional risk factors and elevated levels
of apolipoprotein B for men and reduced levels of apolipoprotein AI for women as
independent variables for CAD. After adjustment for the most important subset of
risk factors (age, hypertension, hypercholesterolemia, and smoking),
apolipoprotein B XbaI polymorphism was disclosed as an independent variable for
CAD. Apolipoprotein B XbaI was also selected as an independent variable for acute
myocardial infarction after adjusting for age, hypertension,
hypercholesterolemia, and smoking. Thus, in addition to traditional coronary risk
factors, apolipoproteins B and AI, and apolipoprotein B XbaI polymorphism could
be considered predictors of CAD.
PMID- 10781756
TI - Effect of coronary angiography on use of lipid-lowering agents in women: a report
from the Women's Ischemia Syndrome Evaluation (WISE) study. For the WISE
Investigators.
AB - We sought to assess the impact of coronary angiography results on use of lipid
lowering agents among women enrolled in the Women's Ischemia Syndrome Evaluation
[WISE] study. WISE is a multicenter study designed to evaluate new diagnostic
modalities among women undergoing angiography for suspected coronary artery
disease (CAD). History of atherosclerosis, risk factors for CAD, and low-density
lipoprotein (LDL) cholesterol are determined at baseline. The percentage of women
at LDL cholesterol goal, use of lipid-lowering agents, and eligibility for lipid
lowering therapy were determined based on National Cholesterol Education Program
II guidelines at baseline and 6-week follow-up. Among the 212 women for whom
angiographic data were available, 84 had known atherosclerosis, 80 had no history
of atherosclerosis but > or =2 risk factors (high risk), and 48 had no history of
atherosclerosis and <2 risk factors (low risk). At baseline, LDL cholesterol
goals were met in 24% women with atherosclerosis, in 56% high-risk women, and in
88% low-risk women. Angiography revealed previously undiagnosed CAD in 70% of the
high-risk and in 42% of the low-risk women. After angiography results were
available, 6 women started lipid-lowering therapy and 2 stopped. Based on
National Cholesterol Education Program II guidelines, 63 additional women would
have been eligible for pharmacologic lipid-lowering therapy. Intensification of
lipid-lowering therapy was not apparent 6 weeks after coronary angiography in
women with newly diagnosed CAD or among women whose diagnosis was confirmed.
PMID- 10781758
TI - Value of QT dispersion in the interpretation of treadmill exercise
electrocardiograms of patients without exercise-induced chest pain or ST-segment
depression.
AB - It has recently been reported that increased QT dispersion seen on standard 12
lead electrocardiograms (ECGs) reflects transient myocardial ischemia. The
present study investigates whether increased QT dispersion induced by exercise is
a useful indicator for detecting significant coronary stenosis in patients who do
not have chest pain or significant ST-segment depression in response to exercise.
We studied 135 consecutive patients (mean age +/- SD, 55 +/- 9 years; 97 men and
38 women) who complained of anginal chest pain and who did not have exercise
induced chest pain or significant ST-segment depression during treadmill exercise
electrocardiography. Coronary angiography was performed in all of patients. Of
the 135 patients, 97 had no significant coronary stenosis, 25 had 1-vessel
coronary artery disease (CAD), and 13 had multivessel CAD. QT dispersion
immediately after exercise was significantly greater in the group with
significant coronary stenosis than without significant coronary stenosis (62 +/-
13 vs 40 +/- 14 ms, p <0.0001). When QT dispersion >/=60 ms immediately after
exercise was considered a positive result, this indicator had a sensitivity of
74%, a specificity of 85%, and an accuracy of 81% for the diagnosis of
significant coronary stenosis. In conclusion, we have shown that QT dispersion
immediately after exercise is useful for detecting significant CAD in patients
who do not have exercise-induced chest pain or significant ST-segment depression.
PMID- 10781759
TI - Multiple-dose efficacy and safety of an extended-release form of niacin in the
management of hyperlipidemia.
AB - This multicenter trial evaluated the safety and efficacy of escalating doses of
Niaspan (niacin extended-release tablets) and placebo (administered once-a-day at
bedtime) in patients with primary hyperlipidemia on the percent change from
baseline in levels of low-density lipoprotein (LDL) cholesterol and
apolipoprotein B. Extended-release niacin was initiated at a dose of 375 mg/day,
raised to 500 mg/day, and further increased in 500-mg increments at 4-week
intervals to a maximum of 3,000 mg/day. A total of 131 patients (n = 87, extended
release niacin; n = 44, placebo) were treated for 25 weeks with study medication
after a 6-week diet lead-in/drug washout phase and 2-week baseline LDL
cholesterol stability phase. Significant decreases from baseline in levels of LDL
cholesterol and apolipoprotein B became apparent with the 500-mg/day dose and
were consistent at all subsequent doses (p < or =0. 05), reaching 21% and 20%,
respectively, at the 3,000-mg/day dose. Significant increases from baseline in
levels of high-density lipoprotein cholesterol became apparent with the 500
mg/day dose and were consistent at all subsequent doses (p < or = 0.05), reaching
30% at the 3,000-mg dose. Significant decreases from baseline in triglycerides
and lipoprotein(a) occurred at the 1,000-mg dose and were apparent at all
subsequent doses (p < or =0.05), reaching 44% and 26%, respectively, at the 3,000
mg dose. The most common adverse events were flushing and gastrointestinal
disturbance. Transaminase increases were relatively small, and the proportion of
patients who developed liver function abnormalities on extended-release niacin
was not significantly different from placebo. Thus, extended-release niacin was
generally well tolerated and demonstrated a dose-related ability to alter
favorably most elements of the lipid profile.
PMID- 10781760
TI - Acute hemodynamic effects of right ventricular pacing site and pacing mode in
patients with congestive heart failure secondary to either ischemic or idiopathic
dilated cardiomyopathy.
AB - The hemodynamic effects of pacing in patients with congestive heart failure (CHF)
remain controversial. Early studies reported that pacing from the right
ventricular (RV) apex improved acute hemodynamic parameters in patients with left
ventricular systolic dysfunction, but these findings were not confirmed in
subsequent controlled studies. More recently, it has been proposed that pacing
from the RV side of the ventricular septum improves hemodynamic function compared
with intrinsic conduction or apical pacing. Either dual-chamber or ventricular
pacing have been evaluated, again with inconsistent findings. To assess the
effects of pacing site and mode on acute hemodynamic function, we evaluated 21
subjects with CHF and intrinsic conduction disease. Hemodynamics were compared in
AAI, VVI, and DDD modes with pacing from the RV apex or high septum. The pacing
rate was constant in each patient and the order of testing was randomized. In the
absence of ventricular pacing (AAI mode), the mean systemic arterial pressure was
85 +/- 11 mm Hg, the right atrial pressure was 11 +/- 4 mm Hg, the pulmonary
capillary wedge pressure was 18 +/- 8 mm Hg and the cardiac index was 2.4 +/- 0.7
L/min/m(2). Compared with AAI pacing, there were no improvements in any
hemodynamic parameter with DDD pacing from either RV site. Hemodynamic function
worsened with VVI pacing from both RV sites. Subgroup analyses of patients with
dilated cardiomyopathy, with prolonged PR interval, or with significant mitral
regurgitation also failed to demonstrate an improvement with pacing. We conclude
that pacing mode but not RV pacing site affects acute hemodynamic function.
Pacing in the DDD mode prevents the deleterious effects of VVI pacing in this
patient population.
PMID- 10781762
TI - Alcohol abuse and dilated cardiomyopathy in men.
AB - Excessive ethanol intake is reported in 3% to 40% of patients with idiopathic
dilated cardiomyopathy (IDC). In the prevasodilator era, the prognosis was
reportedly better in alcoholic than in IDC patients, an advantage limited to
abstinent patients. No large series of patients systematically treated with
angiotensin-converting enzyme inhibitors has since been described. We analyzed
long-term outcome according to alcohol abuse in male patients with IDC. Among 338
men who had been prospectively enrolled in a multicenter registry, 79 (23%) were
defined as alcohol abusers and further classified at follow-up as having stopped
(AAS) or continued (AAC) abuse. AAC subjects at enrollment reported a higher
daily alcohol intake than AAS subjects (178 +/- 113 vs 127 +/- 54 g/day, p =
0.012). During a mean of 59 +/- 35 months, 102 patients died and 45 underwent
transplantation. Seven-year transplant-free survival was significantly lower in
alcohol abusers (41%) than in patients with IDC (53%, p = 0.026), and
significantly lower in AAC subjects (27%) than in either patients with IDC or AAS
(45%) (p = 0. 018). Although IDC patients had beneficial changes in left
ventricular function at follow-up, only AAS patients had significant improvement
in ejection fraction. In this large series of patients treated with angiotensin
converting enzyme inhibitors and prospectively followed up, excessive alcohol
intake was found in about one fourth of cases and persistent alcohol abuse
correlated with a worse prognosis and function at follow-up.
PMID- 10781761
TI - Correlates and impact on outcomes of worsening renal function in patients > or
=65 years of age with heart failure.
AB - 1.5 mg/dl. Based on the number of these factors, a patient's risk for developing
worsening renal function ranged between 16% (< or =1 factor) and 53% (> or =5
factors). After adjusting for confounding effects, worsening renal function was
associated with a significantly longer length of stay by 2.3 days, higher in
hospital cost by $1,758, and an increased risk of in-hospital mortality (odds
ratio 2.72; 95% confidence interval 1.62 to 4.58). In conclusion, worsening renal
function, an event that frequently occurs in elderly patients hospitalized with
heart failure, confers a substantial burden to patients and the healthcare system
and can be predicted by 6 admission characteristics.
PMID- 10781763
TI - Serial echocardiographic measurements of the pulmonary autograft in the aortic
valve position after the Ross operation in a pediatric population using normal
pulmonary artery dimensions as the reference standard.
AB - Serial echocardiographic measurements of the annulus and sinus were obtained in
children before the Ross operation, and early and late postoperatively. Values
were compared with normal standards for the aorta and pulmonary artery (PA).
There was no significant difference between PA annulus measurements before
surgery and the corresponding autograft immediately afterward (1.73 +/- 0.60 cm
preoperatively; 1. 63 +/- 0.58 cm postoperatively, p = NS). Late after surgery
the mean annulus diameter was enlarged compared with the normal aorta (DeltaZ 1.9
+/- 2.4), but remained relatively unchanged compared with the normal PA (DeltaZ
0.7 +/- 1.1, p <0.01). In contrast, the autograft sinus was dilated early after
surgery (1.83 +/- 0.58 cm preoperatively; 2.18 +/- 0.73 cm postoperatively, p
<0.01). Mean sinus Z score further increased compared with both the aorta (DeltaZ
1.3 +/- 1.7) and PA (DeltaZ 1.3 +/- 1.6). Use of standard PA measurements may be
important in the assessment of autograft enlargement. Minimal change in autograft
Z scores over time suggests that annulus enlargement is mainly due to somatic
growth. In contrast, the autograft sinus showed an immediate and continued
disproportionate increase in size over time, suggesting that sinus enlargement is
largely due to passive dilation.
PMID- 10781764
TI - Surgical validation and implications for transcatheter closure of quantitative
echocardiographic evaluation of atrial septal defect.
AB - Accurate evaluation of secundum atrial septal defect (ASD) is important for the
success of transcatheter closure. The purpose of this study was (1) to describe a
quantitative evaluation by transthoracic (TTE) and transesophageal (TEE)
echocardiography of the various morphologic features of ASD that might be
important for patient selection for transcatheter closure, and (2) to assess the
reliability of these 2 methods by surgical findings. Preoperative TTE and TEE
were used to evaluate the ASD of 27 children undergoing surgical closure.
Measurements included the diameters of ASD and the atrial septal lengths in the
transverse and longitudinal axis, and the width of the superior, inferior,
anteroinferior, and posterior septal margins. The shape and location of the ASD
and the adequacy of the septal margins for anchoring occluding devices were
determined. Echocardiographic data were compared with corresponding surgical
measurements. No significant difference occurred in the means of all the
parameters measured with the 3 methods, except for the transverse ASD diameter (p
<0.05). Good agreement occurred between TTE and TEE and surgical data, except for
the transverse ASD diameter, transverse atrial septal length, and the posterior
septal margin on TTE. Intraclass correlations between TTE and TEE and surgical
measurements of all parameters were good, except for the transverse ASD diameter.
The accuracy in determining shape and location of the ASD by TTE and TEE were
100%, whereas that for determining the adequacy of septal margins was 98% and
97%, respectively. In conclusion, TTE and TEE are reliable methods for
quantitative evaluation of ASD.
PMID- 10781765
TI - Pulsed Doppler tissue imaging in endurance athletes: relation between left
ventricular preload and myocardial regional diastolic function.
AB - The aim of this study was to assess the effects of endurance training on
myocardial regional systolic and diastolic function by pulsed Doppler tissue
imaging (DTI). Twenty male water polo players and 20 male control subjects
underwent standard Doppler echocardiography and pulsed DTI, performed in apical
views by placing a sample volume on left ventricular (LV) basal septal and
inferior walls. Age, body surface area, and blood pressure were comparable
between the 2 groups, with lower heart rate in athletes (p <0.001). They had
significantly increased LV mass index (due to both higher wall thickness and end
diastolic diameter), greater endocardial fractional shortening, higher
transmitral early/atrial (E/A) peak velocities ratio. In athletes, DTI analysis
showed significantly prolonged myocardial deceleration time and greater
myocardial E/A peak velocity ratio of septal and inferior walls, whereas
myocardial early peak velocity was increased (p <0.01) only at the inferior wall.
In the overall group, we found univariate relations of septal and inferior E/A
peak velocity ratio and myocardial deceleration time with LV mass levels, and, in
particular, with the sum of wall thickness. By separate multivariate analyses,
however, these relations disappeared, being dependent on heart rate degree.
Another association found between LV end-diastolic diameter and myocardial early
diastolic wave peak velocity of the inferior wall (r = 0.68, p <0.0001) remained
significant (standardized beta coefficient 0.60, p <0.00001), even after
adjusting for heart rate, body surface area, age, and stroke volume (R(2) = 0.71,
p <0.00001). In conclusion, DTI is a useful tool for detecting regional changes
in myocardial function induced by training, because athletes present with an
improvement in diastolic passive properties of myocardium. The higher early
diastolic velocity of the inferior wall and its relation to increased preload may
represent an indicator of aerobic training, allowing quantification of the degree
of LV adaptation to endurance exercise.
PMID- 10781766
TI - In the long run not everybody is dead.
PMID- 10781767
TI - Compensatory enlargement of the coronary artery in acute myocardial infarction.
AB - Compensatory enlargement occurred in 71% of lesions in patients with acute
myocardial infarction and was more common in these patients than in patients with
stable effort angina pectoris. These results suggest that compensatory
enlargement may be associated with plaque rupture and subsequent acute myocardial
infarction.
PMID- 10781768
TI - Immediate and long-term results of "T" stenting for bifurcation coronary lesions.
AB - The technique of "T" stenting, which incorporates wiring both the branches of a
bifurcation lesion, dilating a balloon in the main branch during stent deployment
in the side branch followed by deployment of stent in the main branch, provides
excellent immediate results in terms of technical and procedural success.
However, further innovations are mandated to optimize the long-term outcome,
which with a restenosis rate of 63%, can be described as not encouraging.
PMID- 10781769
TI - A randomized study comparing two guidewire strategies for angioplasty of chronic
total coronary occlusion.
AB - Chronic total coronary occlusions were more frequently crossed using the
Crosswire as a primary guidewire strategy than with the conventional strategy.
This strategy resulted in a lower number of guidewires being used, a trend toward
shorter procedural and fluoroscopy times, and decreased use of contrast media.
PMID- 10781770
TI - Changes in plasma norepinephrine and endothelin levels and metabolic profile
after AT1-receptor blockade in human hypertension.
AB - In essential hypertensive subjects, acute and chronic administration of losartan
was followed by favorable neurohormonal (norepinephrine, endothelin-1) and
metabolic changes (microalbuminuria).
PMID- 10781771
TI - Generic antiarrhythmics are not therapeutically equivalent for the treatment of
tachyarrhythmias.
AB - The consequences of antiarrhythmic drug formulation substitution were assessed by
survey of 130 experts on arrhythmias. Fifty-four arrhythmia recurrences, 7
proarrhythmic events, and 3 deaths resulting from generic substitution are
reported, thus raising serious concerns about both antiarrhythmic drug
substitution and the adequacy of the generic drug approval process.
PMID- 10781772
TI - Comparative effects of permanent biventricular pacing for refractory heart
failure in patients with stable sinus rhythm or chronic atrial fibrillation.
AB - This study aimed to compare the long-term benefit of biventricular pacing in drug
refractory heart failure in patients with dilated cardiomyopathy who were in
stable sinus rhythm or had persistent atrial fibrillation. The results showed
that permanent biventricular pacing in such patients significantly improves
exercise tolerance in both groups of patients; however, the benefit tended to be
greater in patients with atrial fibrillation.
PMID- 10781773
TI - Comparison of risk of orthostatic hypotension in elderly depressed hypertensive
women treated with nortriptyline and thiazides versus elderly depressed
normotensive women treated with nortriptyline.
AB - This is a nonblind, case-controlled study comparing the risk of orthostatic
hypotension (OH) in 2 groups of elderly depressed women: 22 normotensive and 21
hypertensive patients receiving thiazides. Blood pressure measurements and tilt
table tests produced similar results: increased drop in systolic blood pressure
(SBP) after standing (p <0.001), with no significant differences between the
groups (p = 0.523). There were no changes on diastolic blood pressure (DBP) after
standing, or in SBP or DBP at rest. Dizziness was reported by 23 subjects (53.5%)
before treatment, and by 16 subjects (38.1%) at week 8. Complaints of dizziness
were not associated with OH (Kappa = 0.07).
PMID- 10781774
TI - Premature closure of the foramen ovale associated with aortic stenosis, left
ventricular dilation with thrombus, and early mortality.
AB - Premature foramen ovale (FO) closure has been postulated as a cause of
hypoplastic left heart syndrome. We suggest that premature FO closure is also
associated with left ventricular (LV) dilation and LV thrombus formation, and
that FO closure in patients with aortic stenosis and LV dilation is a secondary
event that occurs later in gestation than that seen with the hypoplastic left
heart.
PMID- 10781775
TI - Routine use of anaerobic blood cultures: are they still indicated?
AB - PURPOSE: To determine the number of patients with bacteremia and fungemia and to
evaluate the utility of routine anaerobic blood cultures as part of the work-up
for suspected bacteremia. SUBJECTS AND METHODS: Retrospective review of
microbiology data followed by selective chart review at a university-affiliated
Veterans Affairs Medical Center. We determined the number of bacterial blood
cultures drawn from January 1, 1994, to December 31, 1996, and the number of
anaerobic, aerobic, and fungal isolates. Chart reviews were then performed on all
patients with a positive anaerobic result. RESULTS: There were 6,891 sets of
blood cultures processed through the laboratory, yielding 1,626 patients with
positive results. Anaerobic isolates were recovered from 36 patients (2.2%) in 48
bottles. Aerobic isolates were recovered from 1550 patients (95.3%), and fungal
isolates were recovered from 40 patients (2.5%). Seven patients (0.4%) had true
anaerobic bacteremia. All seven patients had an obvious source of anaerobic
infection that was known or suspected before the cultures were drawn. Antibiotic
changes were made in four of these patients after the positive anaerobic results
were known. Antibiotic changes led to clinical improvement in one patient.
CONCLUSIONS: Routine use of anaerobic blood cultures rarely results in clinically
important diagnostic or therapeutic benefits, based on the low incidence of
anaerobic bacteremia in patients who are not at increased risk. Anaerobic blood
cultures should be selectively ordered in patients at risk for anaerobic
infections.
PMID- 10781776
TI - A randomized trial of distant healing for skin warts.
AB - PURPOSE: Distant healing, a treatment that is transmitted by a healer to a
patient at another location, is widely used, although good scientific evidence of
its efficacy is sparse. This trial was aimed at assessing the efficacy of one
form of distant healing on common skin warts. SUBJECTS AND METHODS: A total of 84
patients with warts were randomly assigned either to a group that received 6
weeks of distant healing by one of 10 experienced healers or to a control group
that received a similar preliminary assessment but no distant healing. The
primary outcomes were the number of warts and their mean size at the end of the
treatment period. Secondary outcomes were the change in Hospital Anxiety and
Depression Scale and patients' subjective experiences. Both the patients and the
evaluator were blinded to group assignment. RESULTS: The baseline characteristics
of the patients were similar in the distant healing (n = 41) and control groups
(n = 43). The mean number and size of warts per person did not change
significantly during the study. The number of warts increased by 0.2 in the
healing group and decreased by 1.1 in the control group (difference [healing to
control] = -1.3; 95% confidence interval = -1.0 to 3.6, P = 0.25). Six patients
in the distant healing group and 8 in the control group reported a subjective
improvement (P = 0.63). There were no significant between-group differences in
the depression and anxiety scores. CONCLUSION: Distant healing from experienced
healers had no effect on the number or size of patients' warts.
PMID- 10781777
TI - Effect of clarithromycin on experimental rhinovirus-16 colds: a randomized,
double-blind, controlled trial.
AB - PURPOSE: Macrolide antibiotics are frequently prescribed to patients with
symptoms of a common cold. Despite their lack of proven antiviral activity,
macrolide antibiotics may have anti-inflammatory actions, such as inhibition of
mucus secretion and production of interleukins 6 and 8 by epithelial cells.
Because the symptoms of rhinovirus colds are attributed to the inflammatory
response to infection, we studied the effects of treatment with clarithromycin on
the symptomatic and inflammatory response to nasal inoculation with rhinovirus.
SUBJECTS AND METHODS: We performed a prospective, double-blind, controlled trial
in 24 healthy subjects who were seronegative for antibodies to rhinovirus-16.
Subjects were randomly assigned to receive either clarithromycin (500 mg) or
trimethoprim-sulfamethoxazole (800/160 mg, as a control antibiotic) twice a day
for 8 days, beginning 24 hours before inoculation with rhinovirus-16. RESULTS:
All 12 subjects in each group were infected and developed symptomatic colds. The
groups did not differ in the intensity of cold symptoms (median [25th to 75th
percentile] score in the clarithromycin group of 25 [5 to 33] versus 21 [11 to
26] in the trimethoprim-sulfamethoxazole group, P = 0.86), weight of nasal
secretions (25 g [8 to 56 g] versus 12 g [5 to 28 g], P = 0.27), or decline in
nasal peak flow during the 8 days following viral inoculation. In both groups,
similar and significant increases from baseline were observed in the numbers of
total cells and neutrophils, and in the concentrations of interleukins 6 and 8,
in nasal lavage fluid during the cold. The changes that we observed did not
differ from those in an untreated historical control group. CONCLUSIONS: We
conclude that clarithromycin treatment has little or no effect on the severity of
cold symptoms or the intensity of neutrophilic nasal inflammation in experimental
rhinovirus-16 colds.
PMID- 10781778
TI - Care and outcomes of elderly patients with acute myocardial infarction by
physician specialty: the effects of comorbidity and functional limitations.
AB - PURPOSE: Whether patients with acute myocardial infarction who are treated by
cardiologists have better outcomes than patients treated by generalist physicians
is controversial. Because some of the survival benefit associated with cardiology
care may be due to baseline differences in patient characteristics, we evaluated
how differences in case-mix of comorbid illness and functional limitations may
explain the association between specialty care and survival. MATERIALS AND
METHODS: We examined the records of 109,243 Medicare beneficiaries hospitalized
for myocardial infarction from 1994 to 1995 from the national Cooperative
Cardiovascular Project to evaluate the association of physician specialty with 30
day and 1-year mortality. We assessed the extent to which this relation was
mediated by differences in the use of guideline-supported therapies (aspirin,
beta-blockers, reperfusion, angiotensin-converting enzyme inhibitors) or
differences in the clinical characteristics of the patients. RESULTS: Patients
who had board-certified cardiologists as attending physicians had the least
number of comorbid conditions, whereas patients who had general practitioners or
internal medicine subspecialists as attending physicians usually had the most
comorbidities. Cardiologists had the greatest use of most guideline-supported
therapies, and general practitioners had the lowest use. After adjustment for
severity of myocardial infarction, clinical presentation, and hospital
characteristics, patients treated by cardiologists were less likely to die within
1 year (relative risk [RR] = 0.92, 95%, confidence interval [CI]: 0.89 to 0. 95),
and patients cared for by other general practitioners were more likely to die
within 1 year (RR = 1.09, 95% CI: 1.03 to 1.14), than patients cared for by
general internists. After adjusting for additional measures of comorbid illness
and functional limitations, the 1-year survival benefit associated with
cardiology care was attenuated relative to internists (RR = 0.97, 95% CI: 0.94 to
1.0), and the excess mortality associated with general practitioners decreased
(RR = 1.05, 95% CI: 1.00 to 1.11). After further adjustment for the use of
guideline-supported therapies, both differences in 1-year survival between
patients treated by cardiologists or general practitioners were not significantly
different from those of patients treated by internists. CONCLUSION: Studies
comparing outcomes by physician specialties that do not adjust adequately for
differences in patient characteristics may attribute more benefit than is
appropriate to specialists who treat patients who have fewer comorbid conditions.
Some of the remaining benefit-at least among patients with myocardial infarction
may be attributable to greater use of recommended therapies.
PMID- 10781779
TI - Patient centeredness in medical encounters requiring an interpreter.
AB - PURPOSE: Patient-centered interviewing is associated with greater patient
satisfaction and better medical outcomes than traditional encounters, but
actively seeking patients' views of their illnesses and encouraging patients to
express expectations, thoughts, and feelings is difficult in encounters that
require an interpreter. We sought to examine physicians' use of the patient
centered approach with patients who required the assistance of an interpreter.
SUBJECTS AND METHODS: A cross-sectional sample of patients was videorecorded
during visits with physicians at a multi-ethnic, university-affiliated, primary
care clinic. Nineteen medical encounters of Spanish-speaking patients who
required an interpreter and 19 matched English-speaking encounters were coded for
frequency that patients mentioned symptoms, feelings, expectations, and thoughts
(collectively called "offers"). Physicians' responses were coded as ignoring,
closed, open, or facilitative of further discussion. RESULTS: English-speaking
patients made a mean (+/- SD) of 20 +/- 11 offers, compared with 7 +/- 4 for
Spanish-speaking patients (P = 0.001). Spanish-speaking patients also were less
likely to receive facilitation from their physicians and were more likely to have
their comments ignored (P <0.005). English-speaking patients usually received an
answer or acknowledgment to their questions even if the physicians did not
encourage further discussion on the topic. CONCLUSION: Spanish-speaking patients
are at a double disadvantage in encounters with English-speaking physicians:
these patients make fewer comments, and the ones they do make are more likely to
be ignored. The communication difficulties may result in lower adherence rates
and poorer medical outcomes among Spanish-speaking patients.
PMID- 10781780
TI - The sound that failed.
PMID- 10781781
TI - Ursodeoxycholic acid therapy in hepatobiliary disease.
AB - Ursodeoxycholic acid is a hydrophilic bile acid that under normal circumstances
represents a small fraction of the bile acid pool in humans. It is effective in
dissolving cholesterol gallstones in appropriately selected patients.
Ursodeoxycholic acid improves serum alkaline phosphatase and aminotransferase
levels in primary biliary cirrhosis, but its effects on rates of liver
transplantation and death are less certain. Ursodeoxycholic acid has had
promising [corrected] effects in several other cholestatic liver diseases, such
as cystic fibrosis and intrahepatic cholestasis of pregnancy, but data are too
preliminary to make recommendations about its routine use in these conditions.
Its effects are mediated by amelioration of damage to cell membranes caused by
retained toxic bile acids. Ursodeoxycholic acid improves biliary secretion of
bile acids, may improve bile flow, and it has immunomodulatory properties that
may reduce immune-mediated liver damage. However, its use in the treatment of
cholestatic liver disease remains uncertain pending additional randomized trials.
PMID- 10781782
TI - Thalidomide: current and potential clinical applications.
AB - More than three decades after its withdrawal from the world marketplace,
thalidomide is attracting growing interest because of its reported
immunomodulatory and anti-inflammatory properties. Current evidence indicates
that thalidomide reduces the activity of the inflammatory cytokine tumor necrosis
factor (TNF)-alpha by accelerating the degradation of its messenger RNA.
Thalidomide also inhibits angiogenesis. Recently, the drug was approved for sale
in the United States for the treatment of erythema nodosum leprosum, an
inflammatory complication of Hansen's disease. However, it has long been used
successfully in several other dermatologic disorders, including aphthous
stomatitis, Behcet's syndrome, chronic cutaneous systemic lupus erythematosus,
and graft-versus-host disease, the apparent shared characteristic of which is
immune dysregulation. Many recent studies have evaluated thalidomide in patients
with human immunodeficiency virus (HIV) infection; the drug is efficacious
against oral aphthous ulcers, HIV-associated wasting syndrome, HIV-related
diarrhea, and Kaposi's sarcoma. To prevent teratogenicity, a comprehensive
program has been established to control access to the drug, including
registration of prescribing physicians, dispensing pharmacies, and patients;
mandatory informed consent and education procedures; and limitation of the
quantity of drug dispensed. Clinical and, in some patients, electrophysiologic
monitoring for peripheral neuropathy is indicated with thalidomide therapy. Other
adverse effects include sedation and constipation. With appropriate safeguards,
thalidomide may benefit patients with a broad variety of disorders for which
existing treatments are inadequate.
PMID- 10781783
TI - Use of cholesterol-lowering medications in the United States from 1991 to 1997.
PMID- 10781784
TI - Effective teaching for preceptors of ambulatory care: a survey of medical
students.
PMID- 10781786
TI - Diagnostic dilemma
AB - In those issues in which our regular Case of the Month does not appear, The Green
Journal will present a Diagnostic Dilemma-an electrocardiogram and/or radiograph
with a brief case history-as a challenge for our readers to solve. The correct
answer appears on p. 512.If you would like to contribute a Diagnostic Dilemma,
please submit a high-quality copy of the EKG or radiograph with a brief synopsis
(<250 words) of the case to The American Journal of Medicine's editorial office.
PMID- 10781785
TI - Diagnostic dilemma
AB - In those issues in which our regular Case of the Month does not appear, The Green
Journal will present a Diagnostic Dilemma-an electrocardiogram and/or radiograph
with a brief case history-for our readers to solve. The correct answer appears on
p. 511 of this issue.If you would like to contribute a Diagnostic Dilemma, please
submit a high-quality copy of the EKG or radiograph with a brief synopsis (<250
words) of the case to The American Journal of Medicine's editorial office.
PMID- 10781787
TI - The controversy regarding routine anaerobic blood cultures.
PMID- 10781788
TI - Distant healing: an unlikely hypothesis.
PMID- 10781790
TI - Answer to diagnostic dilemma: radiograph
PMID- 10781789
TI - Interpreters and communication in the clinical encounter.
PMID- 10781791
TI - Answer to diagnostic dilemma: EKG
PMID- 10781792
TI - Academic internal medicine: challenges and opportunities- part I
PMID- 10781793
TI - A central role for the endothelial NADPH oxidase in atherosclerosis.
AB - An increasing body of evidence has demonstrated that NADPH oxidase plays a
critical role in several early steps leading toward the development of
atherosclerosis. These effects appear to be carried out by both the ability of O2
to act as a small second messenger molecule, and potentially the oxidation of
low density lipoprotein by O2-. We describe a model for the initiation and
development of atherosclerosis that suggests targeted inhibition of NADPH oxidase
as a powerful site for prevention and treatment of this disease.
PMID- 10781794
TI - Mg(2+) induces intermembrane electron transport by cytochrome c desorption in
mitochondria with the ruptured outer membrane.
AB - The mechanism of external NADH oxidation in rat liver mitochondria is not clear
yet, but it evidently includes the intermembrane electron transport (IMET). We
showed that Mg(2+) significantly stimulated IMET insensitive to rotenone
antimycin A-myxothiazol in mitochondria with the hypotonically damaged outer
membrane, even in the absence of exogenous cytochrome c. This effect was more
specific than simply ionic strength increase. Direct evidence for cytochrome c
desorption from mitochondrial membranes under 4 mM Mg(2+) influence was obtained
to explain the stimulatory effect of Mg(2+) on external NADH oxidation that was
coupled to the inner membrane potential generation. Obtained data suggest that
cytochrome b(5) is normally oriented towards the cytosol in the outer membrane,
and can be accessible for endogenous cytochrome c reduction only through the
outer membrane rupture or permeabilization, to activate external NADH oxidation.
PMID- 10781795
TI - Efp as a primary estrogen-responsive gene in human breast cancer.
AB - We have previously isolated the efp (estrogen-responsive finger protein) that is
required for the normal estrogen-induced cell proliferation. Here, we show the
genomic organization of the human efp gene which consists of nine exons. The efp
mRNA was expressed in human breast tumors and the estrogen-induced expression of
the efp was found in MCF-7 human breast cancer cells. Moreover, efp promoter
activity was enhanced through the estrogen-responsive element dependent on
estrogen and estrogen receptor. These results suggest that the efp can mediate
estrogen actions such as cell growth in human breast cancer as a primary
responsive gene.
PMID- 10781796
TI - Large accumulation of mRNA and DNA point modifications in a plant senescent
tissue.
AB - Although nucleic acids are the paradigm of genetic information conservation, they
are inherently unstable molecules that suffer intrinsic and environmental damage.
Oxidative stress has been related to senescence and aging and, recently, it has
been shown that mutations accumulate at high frequency in mitochondrial DNA with
age. We investigated RNA and DNA modifications in cork, a senescent plant tissue
under high endogenous oxidative stress conditions. When compared to normally
growing young tissue, cork revealed an unexpected high frequency of point
modifications in both cDNA (Pn = 1/1784) and nuclear DNA (Pn = 1/1520). Cork
should be viewed as a mosaic of genetically heterogeneous cells. This has
biological implications: it supports somatic mutation models for aging and
challenges 'single cDNA clone' as descriptor for the molecular genetics of
senescent tissues.
PMID- 10781798
TI - The sequences of enterohemorrhagic Escherichia coli and Yersinia pestis that are
homologous to the enteroaggregative E. coli heat-stable enterotoxin gene: cross
species transfer in evolution.
AB - The enteroaggregative Escherichia coli heat-stable enterotoxin 1 (EAST1) gene is
widely distributed among diarrheagenic E. coli. In this study, we examined the
sequences of enterohemorrhagic E. coli (EHEC) strains by PCR and sequencing. All
the EHEC strains possessed the EAST1 gene homologues but with two types of
mutations. One of the mutation types was strongly associated with the large
outbreak episodes in 1996 in Japan. Sequence comparison showed that the EHEC
sequences are a branch of the EAST1 gene sequence family that showed the cross
species transfer in evolution among E. coli and Yersinia pestis.
PMID- 10781797
TI - Further studies on the reconstitution of glucosylceramidase activity by Sap C and
anionic phospholipids.
AB - The reconstitution of the activity of the lysosomal enzyme glucosylceramidase
requires anionic phospholipids and, at least, a protein factor, saposin C (Sap
C). We have previously proposed a mechanism for the glucosylceramidase activation
[Vaccaro et al. (1993) FEBS Lett. 336, 159-162] which implies that Sap C promotes
the association of the enzyme with anionic phospholipid-containing membranes,
thus favoring the contact between the enzyme and its lipid substrate,
glucosylceramide. We have further investigated the properties of Sap C using a
fluorescent hydrophobic probe such as 4, 4'-dianilino-1,1'-binaphthyl-5,5'
disulfonic acid (bis-ANS). The binding between bis-ANS and Sap C was pH
dependent, indicating that protonation leads to increased exposure of hydrophobic
surfaces of Sap C. The interaction of Sap C with membranes, triggered by the
development of hydrophobic properties at low pH values, was affected by the
content of anionic phospholipids, such as phosphatidylserine or
phosphatidylinositol, suggesting that anionic phospholipids have the potential to
modulate the insertion of Sap C in the hydrophobic environment of lysosomal
membranes. We previously showed that Sap C and anionic phospholipids are both
required for the binding of glucosylceramidase to large vesicles. We have
presently observed that Sap C is able to promote the association of
glucosylceramidase with the lipid surface only when anionic phospholipids exceed
a concentration of 5-10%. This level can be reached by summing lower amounts of
individual anionic phospholipids, since they have additive effects. The present
data extend and refine our model of the mechanism of glucosylceramidase
activation and stress the key role of pH, Sap C and anionic phospholipids in
promoting the interaction of the enzyme with membranes.
PMID- 10781800
TI - F-ATPase: specific observation of the rotating c subunit oligomer of EF(o)EF(1).
AB - The rotary motion in response to ATP hydrolysis of the ring of c subunits of the
membrane portion, F(o), of ATP synthase, F(o)F(1), is still under contention. It
was studied with EF(o)EF(1) (Escherichia coli) using microvideography with a
fluorescent actin filament. To overcome the limited specificity of actin
attachment through a Cys-maleimide couple which might have hampered the
interpretation of previous work, we engineered a 'strep-tag' sequence into the C
terminal end of subunit c. It served (a) to purify the holoenzyme and (b) to
monospecifically attach a fluorescent actin filament to subunit c. EF(o)EF(1) was
immobilized on a Ni-NTA-coated glass slide by the engineered His-tag at the N
terminus of subunit beta. In the presence of MgATP we observed up to five
counterclockwise rotating actin filaments per picture frame of 2000 microm(2)
size, in some cases yielding a proportion of 5% rotating over total filaments.
The rotation was unequivocally attributable to the ring of subunit c. The new,
doubly engineered construct serves as a firmer basis for ongoing studies on
torque and angular elastic distortions between F(1) and F(o).
PMID- 10781799
TI - Hydrogen exchange monitored by MALDI-TOF mass spectrometry for rapid
characterization of the stability and conformation of proteins.
AB - Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
(MALDI-TOF MS) has been used to monitor hydrogen exchange on entire proteins. Two
alternative methods have been used to carry out the hydrogen exchange studies,
exchanging deuteron (H to D experiments) or proton (D to H experiments). In the
former case, the use of a deuterated matrix has made possible to overcome back
exchange problems and attain reproducible results. The methods presented have
been used to determine the slow exchange core of the potato carboxypeptidase
inhibitor in different folding states, and to differentially compare the
activation domain of human procarboxypeptidase A2 versus three site-directed
mutants of different conformational stability. In this work, we show that by
using MALDI-TOF MS to monitor hydrogen exchange in entire proteins, it is
possible to rapidly check the folding state of a protein and characterize
mutational effects on protein conformation and stability, while requiring minimal
amounts of sample.
PMID- 10781801
TI - Anandamide induces apoptosis of PC-12 cells: involvement of superoxide and
caspase-3.
AB - Anandamide (arachidonoylethanolamide), an endogenous cannabinoid receptor ligand
has been suggested to have physiological role in mammalian nervous system.
However, little is known about the role of anandamide on neuronal cells. Here, we
demonstrate that anandamide causes death of PC-12 cells, showing marked DNA
condensation and fragmentation, appearance of cells at sub-G(0)/G(1) and
redistribution of phosphatidyl serine, the hallmark features of apoptosis.
Anandamide raised intracellular superoxide level and CPP32-like protease activity
in PC-12 cells markedly. Furthermore, antioxidant N-acetyl cysteine prevented
anandamide-induced superoxide anion formation and cell death, implying that
intracellular superoxide is a novel mediator of anandamide-induced apoptosis of
PC-12 cells.
PMID- 10781802
TI - Involvement of SH2-SH2-SH3 domain of phospholipase cgamma1 in NF-kappaB
signaling.
AB - To directly define the role of phospholipase Cgamma1 (PLCgamma1) in NF-kappaB
activation, NF-kappaB promoted luciferase reporter gene plasmid (pNF-kappaB-Luc)
was transfected into rat-3Y1 fibroblasts that overexpress whole PLCgamma1
(PLCgamma1-3Y1), src homology domains SH2-SH2-SH3 of PLCgamma1 (SH223-3Y1) and v
src (Src-3Y1). Transient transfection with pNF-kappaB-Luc remarkably increased
the luciferase activity in all three transformants compared with normal rat-3Y1
cells. Pretreatment with inhibitors of protein tyrosine kinase reduced this
increase in luciferase activity, but U73122 (a PLC inhibitor) did not. While
PD98059, an inhibitor of mitogen activated protein kinase (MAPK), significantly
reduced the luciferase activity, there was no effect by wortmannin and Ro-31
8220, inhibitors of phosphatidylinositol 3-kinase (PI3K) and protein kinase C
(PKC), respectively. This study shows a direct evidence that the SH2-SH2-SH3
region of PLCgamma1 contributes to the NF-kappaB signaling and that MAPK, but not
PI3K and PKC, is involved in SH2-SH2-SH3 mediated NF-kappaB activation in these
cells.
PMID- 10781804
TI - Myocyte enhancer factor 2C upregulates MASH-1 expression and induces neurogenesis
in P19 cells.
AB - MEF2C is a transcription factor expressed in neural lineages. After transient
transfection, the MEF2 family of factors can act synergistically with the neural
specific transcription factor, MASH-1, and activate exogenous neural-specific
promoters. To determine whether MEF2C is capable of modulating endogenous gene
expression, P19 cell lines were analyzed that overexpressed MEF2C, termed
P19[MEF2C] cells. Here we show that P19[MEF2C] cells differentiate into neurons
when aggregated with ME(2)SO. MEF2C-induced neurons expressed neurofilament
protein, the nuclear antigen NeuN, as well as MASH-1. Our results indicate that
MEF2C can directly or indirectly activate the expression of MASH-1, leading to
neurogenesis.
PMID- 10781803
TI - MAPK-dependent expression of p21(WAF) and p27(kip1) in PMA-induced
differentiation of HL60 cells.
AB - Treatment of HL60 cells with phorbol 12-myristate 13-acetate (PMA) results in
growth arrest and differentiation towards the macrophage lineage. PMA-induced
changes are easily monitored by morphological changes while cells in suspension
start adhering onto substrate. PMA induces rapid activation of the extracellular
signal-regulated kinases (ERKs). Activation of the ERK pathway is essential to
PMA-induced differentiation of HL60 cells. PMA also induces the expression of the
cyclin-dependent kinase inhibitors p21(WAF) and p27(kip1), which is modulated by
the use of an inhibitor of the ERK cascade. This implies that a link exists
between ERK activation and p21(WAF) and p27(kip1) induction in the process of
terminal differentiation.
PMID- 10781805
TI - Enhanced sensitivity of Streptomyces seoulensis to menadione by superfluous
lipoamide dehydrogenase.
AB - Lipoamide dehydrogenase from Streptomyces seoulensis could facilitate menadione
mediated cytochrome c reduction, which was mostly inhibited by superoxide
dismutase, indicating the obvious involvement of superoxide radical anion. In
this reaction, the production of superoxide radical anion occurred via a
menadione semiquinone radical anion. When exposed to menadione, lipoamide
dehydrogenase-overexpressing cells showed a much lower survival rate with a
concomitant decrease of intracellular protein thiol than the wild-type strain.
These results suggest that lipoamide dehydrogenase is a facilitating agent in the
redox cycling of quinone compounds in vivo as well as in vitro and could
inevitably increase the potential toxicity of the compounds.
PMID- 10781806
TI - Identification of the goldfish 20S proteasome beta6 subunit bound to nuclear
matrix.
AB - Proteasomes are large, multisubunit particles that act as the proteolytic
machinery for most of the regulated intracellular protein breakdown in eukaryotic
cells. Proteasomes are present in both the nucleus and cytoplasm. When we
analyzed the molecular composition of protein constituents of the nuclear matrix
preparation of goldfish oocytes by two-dimensional polyacrylamide gel
electrophoresis followed by sequence analysis, we found a 26 kDa spot identical
in amino acid sequence to the beta6 subunits of the 20S proteasome. No spot of
other subunits of 20S proteasome was detected. Here we describe the cloning,
sequencing and expression analysis of Carassius auratus, beta6_ca, which encodes
one of the proteasome beta subunits from goldfish ovary. From the screening of an
ovarian cDNA library, two types of cDNA were obtained, one 941 bp and the other
884 bp long. The deduced amino acid sequences comprise 239 and 238 residues,
respectively. These deduced amino acid sequences are highly homologous to those
of beta6 subunits of other vertebrates. Immunoblot analysis of nuclear matrix
using anti-proteasome antibodies showed only a spot of beta6_ca. These results
suggest that the beta6 subunit of the goldfish 20S proteasome, beta6_ca, is
responsible for anchoring proteasomes in the nucleus.
PMID- 10781807
TI - Acceleration of oxidative folding of bovine pancreatic ribonuclease A by anion
induced stabilization and formation of structured native-like intermediates.
AB - Phosphate anions accelerate the oxidative folding of reduced bovine pancreatic
ribonuclease A with dithiothreitol at several temperatures and ionic strengths.
The addition of 400 mM phosphate at pH 8.1 increased the regeneration rate of
native protein 2.5-fold at 15 degrees C, 3.5-fold at 25 degrees C, and 20-fold at
37 degrees C, compared to the rate in the absence of phosphate. In addition, the
effects of other ions on the oxidative folding of RNase A were examined. Fluoride
was found to accelerate the formation of native protein under the same oxidizing
conditions. In contrast, cations of high charge density or ions with low charge
density appear to have an opposite effect on the folding of RNase A. The
catalysis of oxidative folding results largely from an anion-dependent
stabilization and formation of tertiary structure in productive disulfide
intermediates (des-species). Phosphate and fluoride also accelerate the initial
equilibration of unstructured disulfide ensembles, presumably due to non-specific
electrostatic and hydrogen bonding effects on the protein and solvent.
PMID- 10781808
TI - Surface plasmon resonance studies prove the interaction of skeletal muscle
sarcoplasmic reticular Ca(2+) release channel/ryanodine receptor with
calsequestrin.
AB - A high affinity molecular interaction is demonstrated between calsequestrin and
the sarcoplasmic reticular Ca(2+) release channel/ryanodine receptor (RyR) by
surface plasmon resonance. K(D) values of 92 nM and 102 nM for the phosphorylated
and dephosphorylated calsequestrin have been determined, respectively.
Phosphorylation of calsequestrin seems not to influence this high affinity
interaction, i.e. calsequestrin might always be bound to RyR. However, the
phosphorylation state of calsequestrin determines the amount of Ca(2+) released
from the lumen. Dephosphorylation of approximately 1% of the phosphorylated
calsequestrin could be enough to activate the RyR channel half-maximally, as we
have shown previously [Szegedi et al., Biochem. J. 337 (1999) 19].
PMID- 10781809
TI - MerF is a mercury transport protein: different structures but a common mechanism
for mercuric ion transporters?
AB - Mercury resistance determinants are widespread in Gram-negative bacteria, but
vary in the number and identity of genes present. We have shown that the merF
gene from plasmid pMER327/419 encodes a 8.7 kDa mercury transport protein, by
determining in vivo mercury volatilisation when MerF is expressed in the presence
of mercuric reductase. We have confirmed that MerC of Tn21 is also a mercuric ion
transporter. We have been able to detect interaction of the periplasmic protein
MerP only with the MerT transporter, and not with MerF or MerC. Hydropathy
analysis led to the prediction of models for MerT, MerC and MerF having three,
four and two transmembrane regions respectively. In all three cases one pair of
cysteine residues is predicted to be within the inner membrane with a second pair
of cysteine residues on the cytoplasmic face, and the second helix contains a
proline and at least one charged residue. The mechanisms of mercuric ion
transport may be similar in these transporters even though their structures in
the membrane differ.
PMID- 10781810
TI - Pore mutations affecting tetrameric assembly and functioning of the potassium
channel KcsA from Streptomyces lividans.
AB - Designed mutations within the Streptomyces lividans kcsA gene resulted in a set
of mutant proteins, which were characterized in respect to their assembly and
channel activities. (i) The amino acid residue leucine 81 located at the external
side of KcsA was found to be exchangeable by a cysteine residue without affecting
the channel characteristics. (ii) Substitution of the first glycine (G77) residue
within the GYG motif by an alanine or substitution of the tyrosine (Y) residue 78
by a phenylalanine (F) led to mutant proteins which form tetramers of reduced
stability. In contrast to the AYG mutant protein, GFG functions as an active K(+)
channel whose characteristics correspond to those of the wild-type KcsA channel.
(iii) The investigated mutant proteins, which carry different mutations (T72A,
T72C, V76A, V76E, G77E, Y78A, G79A, G79D, G79E) within the signature sequence of
the pore region, do not at all or only to a very small degree assemble as
tetramers and lack channel activity.
PMID- 10781811
TI - Subunit interactions in the twin-arginine translocase complex of Escherichia
coli.
AB - A subset of Escherichia coli proteins, in particular cofactor-binding proteins
with so-called twin-arginine signal peptides, is transported to the periplasm via
the twin-arginine translocation (Tat) pathway. The tatA and tatB genes encode
important components of the export system and we have analysed whether the
proteins encoded by these genes physically interact. Using co-immunoprecipitation
experiments, we show that TatA and TatB do indeed associate with each other. Gel
filtration chromatography demonstrates that both proteins are present in a large
complex with an apparent molecular mass of approximately 600 kDa, indicating the
presence of other components and/or several TatA and TatB subunits. Finally, we
show that TatA is stable in the absence of TatB and may participate in a separate
complex lacking TatB in wild-type cells.
PMID- 10781812
TI - Mdm2 binding to a conformationally sensitive domain on p53 can be modulated by
RNA.
AB - Biochemical characterisation of the interaction of mdm2 protein with p53 protein
has demonstrated that full-length mdm2 does not bind stably to p53-DNA complexes,
contrasting with C-terminal truncations of mdm2 which do bind stably to p53-DNA
complexes. In addition, tetrameric forms of the p53His175 mutant protein in the
PAb1620+ conformation are reduced in binding to mdm2 protein. These data suggest
that the mdm2 binding site in the BOX-I domain of p53 becomes concealed when
either p53 binds to DNA or when the core domain of p53 is unfolded by missense
mutation. This further suggests that the C-terminus of mdm2 protein contains a
negative regulatory domain that affects mdm2 protein binding to a second,
conformationally sensitive interaction site in the core domain of p53. We
investigated whether there was a second docking site on p53 for mdm2 protein by
examining the interaction of full-length mdm2 with p53 lacking the BOX-I domain.
Although mdm2 protein did bind very weakly to p53 protein lacking the BOX-I
domain, addition of RNA activated mdm2 protein binding to this truncated form of
p53. These data provide evidence for three previously undefined regulatory stages
in the p53-mdm2 binding reaction: (1) conformational changes in p53 protein due
to DNA binding or point mutation conceals a secondary docking site of mdm2
protein; (2) the C-terminus of mdm2 is the primary determinant which confers this
property upon mdm2 protein; and (3) mdm2 protein binding to this secondary
interaction site within p53 can be stabilised by RNA.
PMID- 10781813
TI - Identification of the Drosophila melanogaster homologue of the mammalian signal
transducer protein, Vav.
AB - Mammalian Vav signal transducer protein couples tyrosine kinase signals with the
activation of the Rho/Rac GTPases, thus leading to cell differentiation and/or
proliferation. We have isolated and characterized the DroVav gene, the homologue
of hVav in Drosophila melanogaster. DroVav encodes a protein (793 residues) whose
similarity with hVav is 47% and with hVav2 and hVav3 is 45%. DroVav preserves the
unique, complex structure of hVav proteins, including the 'calponin homology',
dbl homology, pleckstrin homology; SH2 and SH3 domains in addition to regions
that are acidic rich, proline rich and cysteine rich. DroVav is located on the X
chromosome in polytene interval 18A5;18B and is expressed in all stages of
development and in all tissues. In mammalian cells, DroVav is tyrosine
phosphorylated in response to epidermal growth factor receptor (EGFR) induction;
in vitro, the DroVav SH2 region is associated with tyrosine-phosphorylated EGFR.
Thus, DroVav probably plays a pivotal role as a signal transducer protein during
fruit fly development.
PMID- 10781814
TI - Molecular cloning and functional expression of beta1, 2-xylosyltransferase cDNA
from Arabidopsis thaliana.
AB - The transfer of xylose from UDP-xylose to the core beta-linked mannose of N
linked oligosaccharides by beta1,2-xylosyltransferase (XylT) is a widespread
feature of plant glycoproteins which renders them immunogenic and allergenic in
man. Here, we report the isolation of the Arabidopsis thaliana XylT gene, which
contains two introns and encodes a 60.2 kDa protein with a predicted type II
transmembrane protein topology typical for Golgi glycosyltransferases. Upon
expression of A. thaliana XylT cDNA in the baculovirus/insect cell system, a
recombinant protein was produced that exhibited XylT activity in vitro.
Furthermore, the recombinant enzyme displayed XylT activity in vivo in the insect
cells, as judged by the acquired cross-reaction of cellular glycoproteins with
antibodies against the beta1,2-xylose epitope. The cloned XylT cDNA as well as
the recombinant enzyme are essential tools to study the role of beta1,2-xylose in
the immunogenicity and allergenicity of plant glycoproteins at the molecular
level.
PMID- 10781815
TI - Upregulation of thioredoxin (TRX) expression in giant cell myocarditis in rats.
AB - To examine the possible involvement of a redox regulating mechanism in the
pathogenesis of immune-mediated myocarditis, myocarditis was induced by
immunization of porcine cardiac myosin in rats and immunohistochemistry and
Western blot for thioredoxin (TRX) were performed. Immunohistochemistry for 8
hydroxy-2'-deoxyguanosine (8-OHdG) and nuclear factor kappa-B (NF-kappaB) was
also performed. TRX was upregulated in the acute stage, but not in the chronic
stage, and the expression was correlated with the severity of the disease.
Damaged myocytes were strongly immunostained for 8-OHdG and NF-kappaB. Thus, TRX
may be specifically induced by acute inflammatory stimuli, and the development of
acute immune-mediated myocarditis may be regulated by the cellular redox state
via TRX.
PMID- 10781816
TI - Structure of the photosynthetic reaction centre from Rhodobacter sphaeroides
reconstituted with anthraquinone as primary quinone Q(A).
AB - In the photosynthetic reaction centre (RC) from the purple bacterium Rhodobacter
sphaeroides, the primary quinone, a ubiquinone-10 (Q(A)), has been substituted by
anthraquinone. Three-dimensional crystals have been grown from the modified RC
and its structure has been determined by X-ray crystallography to 2.4 A
resolution. The bindings of the head-group from ubiquinone-10 and of the
anthraquinone ring are very similar. In particular, both rings are parallel to
each other and the hydrogen bonds connecting the native ubiquinone-10 molecule to
AlaM260 and HisM219 are conserved in the anthraquinone containing RC. The space
of the phytyl tail missing in the anthraquinone exchanged RC is occupied by the
alkyl chain of a detergent molecule. Other structural changes of the Q(A)-binding
site are within the limit of resolution. Our structural data bring strong credit
to the very large amount of spectroscopic data previously achieved in
anthraquinone-replaced RCs and which have participated in the determination of
the energetics of the quinone system in bacterial RCs.
PMID- 10781817
TI - Phosphorylation of the p190 RhoGAP N-terminal domain by c-Src results in a loss
of GTP binding activity.
AB - p190 RhoGAP is a multi-domain protein that is thought to regulate actin
cytoskeleton dynamics. It can be phosphorylated both in vitro and in vivo at
multiple sites by the Src tyrosine kinase and one or more of these sites is
postulated to modulate p190 function. One of the regions which is multiply
phosphorylated by Src in vitro is the N-terminal GTP binding domain. Using a
partially purified, bacterially expressed recombinant protein that includes the
GTP binding domain (residues 1-389), we show that GTP binds to this fragment in a
specific and saturable manner that is both time- and dose-dependent and that
tyrosine phosphorylation of this fragment by c-Src results in a loss of GTP
binding activity. These findings suggest that tyrosine phosphorylation of the
p190 N-terminal domain can alter its ability to bind GTP.
PMID- 10781818
TI - Molecular characterization of an additional shrimp hyperglycemic hormone: cDNA
cloning, gene organization, expression and biological assay of recombinant
proteins.
AB - The crustacean eyestalk CHH/MIH/GIH neurohormone gene family represents a unique
group of neuropeptides identified mainly in crustaceans. In this study, we report
the cloning and characterization of the cDNA and the gene encoding the
hyperglycemic hormone (MeCHH-B) of the shrimp Metapenaeus ensis. The amino acid
sequence of MeCHH-B shows 85% identity to that of MeCHH-A (formerly MeCHH-like
neuropeptide). Two separate but identical MeCHH-B genes were identified in the
genome of shrimp by library screening and they are located on different CHH gene
clusters. The organization of the MeCHH-B gene is identical to other members of
the CHH/MIH/GIH neurohormone family. MeCHH-B is expressed at a constant level in
the eyestalks of juveniles and mature females. Unlike the MeCHH-A gene, a low
level of MeCHH-B transcripts can also be detected in the central nervous system.
Interestingly, the expression pattern of MeCHH-B in the eyestalk of vitellogenic
females is reversed to that of the MeCHH-A gene. At the middle stage of gonad
maturation, a minimum level of MeCHH-B transcript was recorded and a maximum
level of MeCHH-A transcript was detected. Recombinant proteins for MeCHH-A and
MeCHH-B were produced by a bacterial expression system. The hemolymph glucose
level of bilaterally eyestalk-ablated shrimp increased two-fold 1 h after the
rCHH injection and then returned to normal after 2 h. The hyperglycemic effect of
these fusion proteins is comparable to that of de-stalked shrimp injected with
crude extract from a single sinus gland.
PMID- 10781819
TI - Involvement of the platelet-derived growth factor receptor in angiotensin II
induced activation of extracellular regulated kinases 1 and 2 in human mesangial
cells.
AB - In mesangial cells angiotensin II (Ang II) has been shown to activate
extracellular regulated kinases 1 and 2 (ERK1/2). Here, we studied the role of
the epidermal growth factor receptor (EGFR) and platelet-derived growth factor
receptor (PDGFR) in Ang II-induced ERK1/2 activation in human mesangial cells.
Ang II induced activation of ERK1/2 via the AT(1) receptor, and this response was
blocked by the PDGFR-selective tyrosine kinase inhibitor AG1295, but not by
AG1478, an EGFR-selective tyrosine kinase inhibitor, indicating participation of
the PDGFR, but not of the EGFR in Ang II-induced ERK1/2 activation. In agreement
with this assumption, Ang II caused tyrosine phosphorylation of the PDGFR and the
adapter protein Shc in an AG1295-sensitive fashion. In conclusion, our data show
that Ang II-induced activation of mitogenic signalling cascade in human mesangial
cells involves ligand-independent activation of the PDGFR, but not of the
coexpressed EGFR.
PMID- 10781820
TI - Protective roles for ATM in cellular response to oxidative stress.
AB - ATM (ataxia telangiectasia mutated), the gene mutated in ataxia telangiectasia,
is related to a family of large phosphatidylinositol 3-kinase domain-containing
proteins involved in cell cycle control and DNA repair. We found that ATM(-/-)
DT40 cells were more susceptible than wild-type cells to apoptosis induced not
only by ionizing radiation and bleomycin but also by non-DNA-damaging apoptotic
stimuli such as C(2)-ceramide. Furthermore, the apoptosis induced by C(2)
ceramide and H(2)O(2) was blocked by anti-oxidants, indicating that the ATM(-/-)
DT40 cells had a heightened susceptibility to apoptosis induced by reactive
oxygen intermediates (ROI), presumably due to defective ROI-detoxification
activities. In support of this hypothesis, we found that more ROI were generated
in ATM(-/-) DT40 cells than in wild-type cells, following treatment with the
above apoptotic stimuli. These results indicate that ATM plays important roles in
the maintenance of the cell homeostasis in response to oxidative damage.
PMID- 10781821
TI - Requirement of the Fas ligand-expressing luteal immune cells for regression of
corpus luteum.
AB - Apoptosis in corpus luteum (CL) is induced by prolactin (PRL) in female rats. PRL
induced apoptosis in CL is mediated by the Fas/Fas ligand (FasL) system. The CL
consists of steroidogenic and non-steroidogenic cells, including immunocytes. Fas
mRNA was detected only in the luteal steroidogenic cells, and FasL mRNA was
expressed only by the non-steroidogenic CD3-positive luteal immunocytes. Removing
the luteal immune cells from the luteal cells inhibited PRL-induced luteal cell
apoptosis effectively. Thus, FasL-expressing non-steroidogenic luteal immunocytes
are required for PRL-induced luteal cell apoptosis and heterogeneous induction of
apoptosis by Fas/FasL in CL.
PMID- 10781822
TI - Nerve growth factor induces sphingomyelin accumulation in pheochromocytoma cells.
AB - The pheochromocytoma cells are a well-known model for studying the nerve growth
factor (NGF)-induced molecular changes during the differentiation process. The
involvement of sphingomyelin (SM) was studied using the fluorescent analogue of
ceramide, i.e. N-lissamine rhodaminyl-(12-aminododecanoyl) D-erythro-sphingosine
(C12-LRh-Cer). This fluorescent analogue is metabolically active and can be used
to follow the biosynthesis of SM in intact cells. NGF induces a 4-fold increase
of fluorescent SM content in PC12 cells, when loaded with C12-LRh-Cer. Treatment
of PC12 cells with actinomycin D or cycloheximide completely abolishes the NGF
induced elevation of SM. Inhibition of p140(trkA) receptor by AG-879 prevents
extracellular signal-regulated kinase 1/2 phosphorylation and suppresses the
increase of SM. Inhibition of protein kinase C (PKC), protein kinase A (PKA) and
phosphatidylinositol 3-kinase does not have any effect on NGF-induced C12-LRh-SM
accumulation. On the other hand, activation of PKA or PKC with simultaneous
treatment with NGF has a synergistic effect on increase of SM content. The NGF
induced SM increase in PC12 cells is an effect promoted by other differentiating
agents like dibutyryl cyclic AMP or fibroblast growth factor-2 but not by a
mitogenic agent like epidermal growth factor.
PMID- 10781823
TI - Conformational requirements for Ca(2+)/calmodulin binding and activation of
myosin light chain kinase.
AB - Myosin light chain kinase contains a regulatory segment consisting of an
autoinhibitory region and a calmodulin-binding sequence that folds back on its
catalytic core to inhibit kinase activity. It has been proposed that alpha-helix
formation may be involved in displacement of the regulatory segment and
activation of the kinase by Ca(2+)/calmodulin. Proline mutations were introduced
at putative non-interacting residues in the regulatory segment to disrupt helix
formation. Substitution of proline residues immediately N-terminal of the Trp in
the calmodulin-binding sequence had most significant effects on Ca(2+)/calmodulin
binding and activation. Formation of an alpha-helix in this region upon
Ca(2+)/calmodulin binding may be necessary for displacement of the regulatory
segment allowing phosphorylation of myosin regulatory light chain.
PMID- 10781824
TI - Okadaic acid inhibits insulin-induced glucose transport in fetal brown adipocytes
in an Akt-independent and protein kinase C zeta-dependent manner.
AB - In the present study we have investigated the effect of increased
serine/threonine phosphorylation of insulin receptor substrates-1 and -2 (IRS-1
and IRS-2) by okadaic acid pretreatment on brown adipocyte insulin signalling
leading to glucose transport, an important metabolic effect of insulin in brown
adipose tissue. Okadaic acid pretreatment before insulin stimulation decreased
IRS-1 and IRS-2 tyrosine phosphorylation in parallel to a decrease in their
sodium dodecyl sulfate-polyacrylamide gel electrophoresis mobility. IRS-1/IRS-2
associated p85alpha and phosphatidylinositol (PI) 3-kinase enzymatic activity
were partly reduced in brown adipocytes pretreated with okadaic acid upon
stimulation with insulin. Furthermore, insulin-induced glucose uptake was totally
abolished by the inhibitor in parallel with a total inhibition of insulin-induced
protein kinase C (PKC) zeta activity. However, activation of Akt/PKB or p70 S6
kinase (p70(s6k)) by insulin remained unaltered. Our results suggest that
downstream of PI 3-kinase, insulin signalling diverges into at least two
independent pathways through Akt/PKB and PKC zeta, the PKC zeta pathway
contributing to glucose transport induced by insulin in fetal brown adipocytes.
PMID- 10781826
TI - Structure of polyglutamine.
PMID- 10781825
TI - Stimulation of the yeast high osmolarity glycerol (HOG) pathway: evidence for a
signal generated by a change in turgor rather than by water stress.
AB - The Saccharomyces cerevisiae HOG pathway controls responses to osmotic shock such
as production of the osmolyte glycerol. Here we show that the HOG pathway can be
stimulated by addition of glycerol. This stimulation was strongly diminished in
cells expressing an unregulated Fps1p glycerol channel, presumably because
glycerol rapidly equilibrated across the plasma membrane. Ethanol, which passes
the plasma membrane readily and causes water stress by disturbing the hydration
of biomolecules, did not activate the HOG pathway. These observations suggest
that stimulation of the HOG pathway is mediated by a turgor change and not by
water stress per se.
PMID- 10781827
TI - Probing the polyglutamine puzzle in neurological disorders.
PMID- 10781828
TI - Solution structure and dynamics of biomolecules from Raman optical activity.
AB - Raman optical activity (ROA) measures vibrational optical activity by means of a
small difference in the intensity of Raman scattering from chiral molecules in
right and left circularly polarized incident laser light. The ROA spectra of a
wide range of biomolecules in aqueous solution can now be measured routinely.
Because of its sensitivity to the chiral elements of biomolecular structure, ROA
provides new information about solution structure and dynamics complementary to
that supplied by conventional spectroscopic techniques. This article provides a
brief introduction to the theory and practice of ROA spectroscopy followed by a
review of recent ROA results on polypeptides, proteins, carbohydrates, nucleic
acids and viruses which illustrate how new insight into current problems of
structure, folding and function may be obtained from ROA studies.
PMID- 10781829
TI - Targeted intracellular delivery of photosensitizers.
PMID- 10781830
TI - The Jak-STAT pathway.
AB - A variety of important cellular functions are regulated by cytokines. The Jak
STAT pathway is one of the important signaling pathways downstream of cytokine
receptors. Following binding of a ligand to its cognate receptor, receptor
associated Jaks are activated. STAT proteins are then in turn activated by
tyrosine phosphorylation by Jak kinases, allowing their dimerization and
subsequent translocation into the nucleus, where they modulate expression of
target genes. Indispensable functions of Jaks and STATs in cytokine signaling in
vivo have been revealed through knockout mouse studies. Moreover, the recent
discovery of the CIS/SOCS/JAB/SSI family of inhibitors has contributed to
understanding how this pathway is negatively regulated.
PMID- 10781831
TI - PA28alphabeta double and PA28beta single transfectant mouse B8 cell lines reveal
enhanced presentation of a mouse cytomegalovirus (MCMV) pp89 MHC class I epitope.
AB - PA28 is an interferon-gamma inducible modulator of proteasome function composed
of two subunits, i.e. PA28alpha and PA28beta. Previously we showed that stabile
overexpression of the PA28alpha subunit alone supported MHC class I antigen
presentation of two viral epitopes. However, no information was obtained on the
consequences when PA28alpha and PA28beta function in concert or when PA28beta is
overexpressed on its own. Here we demonstrate that overexpression of PA28alpha
and beta together is similarly efficient in supporting MHC class I antigen
presentation of the MCMV pp89 9mer epitope as PA28alpha alone, excluding a
potentially potentiating role of PA28beta. Surprisingly, and despite the fact
that PA28beta alone was thought to be inactive and to only stabilize PA28
activity, overexpression of PA28beta also resulted in improved antigen
presentation. However, by northernblot and immunoprecipitation experiments we
show that while PA28alpha is able to act alone the observed effect in the
PA28beta and PA28alphabeta transfectant cell lines is due to increased levels of
PA28alphabeta complexes.
PMID- 10781832
TI - Proteomic analysis of T cell activation in the presence of cyclosporin A:
immunosuppressor and activator removal induces de novo protein synthesis.
AB - Cyclosporin A (CsA), a fungal metabolite used in organ transplantation, blocks
the immune responses by interfering with early activation signals preventing the
induction of the IL2 gene. We have previously reported that the removal of the
immunosuppressor provokes the transcription of the IL2 encoding gene. We have now
investigated whether the transcription and translation of other genes accompanies
this process. Withdrawal of CsA and Concanavalin A (ConA) from cultures of murine
T cells activated by ConA in the presence of CsA leads to substantial changes in
the pattern of radio-labelled proteins. A large number of polypeptides were
synthesised de novo. In addition, a set of polypeptides detected prior to
immunosuppressor elimination was not anymore synthesised. Finally, besides these
qualitative changes, quantitative differences in terms of increased or decreased
polypeptide abundance were also observed. The results demonstrate that activation
in the presence of CsA has programmed the T cells to transcribe and translate a
large number of genes, without further reactivation, once the immunosuppressor
and the activator were removed.
PMID- 10781834
TI - Complement factor H: sequence analysis of 221 kb of human genomic DNA containing
the entire fH, fHR-1 and fHR-3 genes.
AB - Complement factor H (fH) is a member of a family of proteins involved in the
regulation of complement activation (RCA). These proteins share a common
structural motif, the Short Consensus Repeat (SCR), which is structurally
conserved among related genes and between phylogenetically divergent species. fH
is composed of 20 such SCRs and a variety of biological functions have been
localised to specific SCR domains. The majority of individual SCRs identified are
encoded by single exons, and processes such as gene conversion, duplication and
exon shuffling have been implicated in the evolution and genomic radiation of SCR
encoding genes. We have analysed two GenBank sequence entries relating to two
overlapping PAC clones sequenced at the Sanger Centre which contain the entire
human fH gene and two adjacent fH-related (fHR) genes, fHR-1 and fHR-3. Here, we
report the detailed analysis of the assembled 221 kb of contiguous, ungapped
genomic sequence from human chromosome 1q32, in part employing the RUMMAGE-DP
automated annotation tool. Genomic duplications involving fH and fHR exons were
identified and Alu/L1 repeat dating established that the duplications occurred
after the separation of rodent and primate lineages. The analysis indicates that
retrotransposition as well as single and multiple exon duplication events are
likely to have been involved in SCR radiation and RCA gene evolution, facilitated
by conservation of splice-phasing and the single-exon, single-SCR nature of the
encoded domains.
PMID- 10781833
TI - Individual V(H) promoters vary in strength, but the frequency of rearrangement of
those V(H) genes does not correlate with promoter strength nor enhancer
independence.
AB - The process of V(D)J recombination is highly regulated. Germline transcription of
unrearranged gene segments precedes V(D)J rearrangement, and the correlation
between germline transcription and accessibility for recombination is strong;
thus it has been suggested that germline transcription may be required for
rearrangement. If germline transcription is essential for rearrangement, then the
level of transcription of individual gene segments might affect the relative
frequency of recombination of those genes. Also, since the intronic enhancer,
E(mu), is very distant from V(H) genes before they rearrange, then any promoters
which were enhancer dependent might have a transcriptional advantage. Here we
study in luciferase vectors the promoters of three functional genes of the
V(H)S107 family, and compare them to that of the most frequently rearranging gene
in the mouse I(g)H locus, V(H)81X, and to a V(H)J558 gene. Within the V(H)S107
family, the three V(H) genes rearrange with very different relative frequencies,
with V1 rearranging the most, and V13 seldom rearranging. We show that only the
strong V(H)J558 promoter has significant luciferase reporter gene activity in the
absence of E(mu). V1 has only 20% as much activity as J558 in the absence of
E(mu), and the other promoters have less than 8% of the activity of J558.
Notably, the 81X promoter has essentially no enhancer-independent activity. In
the presence of E(mu), V1 has equivalent activity to J558, while the other
promoters show much less activity. Again, 81X is the weakest promoter of all,
despite being the most frequently rearranging gene. Finally, we show that the
steady state level of V(H)S107 and V(H)7183 germline transcripts in vivo is very
low. Thus, these data show little correlation between the strength or enhancer
independence of these V(H) promoters and the relative frequency of recombination
of the corresponding V(H) genes. In addition, the data show that individual V(H)
promoters have different strengths even in the presence of E(mu), demonstrating
that even promoters within a single V(H) family can be quite heterogeneous.
PMID- 10781836
TI - Phosphorylation of class I MHC molecules in the absence of phorbol esters is an
intracellular event and may be characteristic of trafficking molecules.
AB - Class I Major Histocompatibility Complex (MHC) molecules are displayed at the
cell surface where they present antigenic peptides to T lymphocytes. Class I MHC
molecules undergo cytoplasmic domain phosphorylation on a serine residue late in
their biosynthesis. Here we show that phosphorylation occurs on mature, beta(2)
microglobulin-associated class I MHC molecules in a mouse lymphoid cell line.
Both recently synthesized class I MHC molecules and molecules which are at least
3 h old become phosphorylated. Approximately 14% of phosphorylated class I MHC
molecules occur at the cell surface. Density gradient analysis indicates that
phosphorylated class I MHC molecules also occur in lamp(+) intracellular
compartments and in fractions containing rab4, a GTP-binding protein associated
with recycling endosomes. Class I MHC molecules are endocytosed and recycled to
the cell surface in these cells. Furthermore, the lysosomotropic drug,
primaquine, inhibits both class I MHC phosphorylation and its recycling back to
the cell surface, suggesting that phosphorylation is related to class I MHC
recycling. These observations are intriguing since several studies have shown
that class I MHC molecules can acquire antigenic peptides in NH(4)Cl-sensitive
compartments. Hence, class I MHC phosphorylation may play a role in regulating
intracellular sorting through these compartments.
PMID- 10781835
TI - Expansion of epitope cross-reactivity by anti-idiotype modulation of the primary
humoral response.
AB - The primary humoral response produces antigen-specific antibodies so to clear the
initial infection, and generates a population of corresponding memory cells to
prevent infection by future encounters with the same pathogen. The continuous
genetic modification of a pathogen's exterior, however, is one mechanism used to
evade the immune defenses of its host. Here we describe a novel means, involving
anti-idiotypic antibodies, by which the host can counteract such pathogen genetic
alterations by modulation of its primary humoral response. An autoimmune response
against primary antibodies, Ab1's, creates anti-idiotypic antibodies (Ab2's),
some of which (designated Ab2alpha) are able to bind the Ab1/antigen complex. We
have discovered that binding of Ab2alpha to its corresponding Ab1 can expand
Ab1's ability to bind variations of its antigen. This expanded epitope cross
reactivity is shown not only to increase the binding activity of Ab1 but also its
ability to neutralize a variant infectious virus. MAb M77 is an Ab1, which is
highly strain-specific for the HIV-1 envelope protein gp120(IIIB). This Ab1 can
be rendered cross-reactive and neutralizing for an otherwise resistant HIV strain
by its interaction with a unique anti-idiotypic Ab2alpha (GV12). Furthermore,
molecular characterization of this expanded cross-reactivity was accomplished
using combinatorial phage display peptide libraries.
PMID- 10781837
TI - TRAF-3 interacts with p62 nucleoporin, a component of the nuclear pore central
plug that binds classical NLS-containing import complexes.
AB - The TRAF-3 gene encodes a number of splice-variant isoforms that function as
adapter molecules in NF-kappaB signaling, in part by associating with the
cytoplasmic tails of CD40 or other TNF-receptor (TNF-R) family members. To
identify downstream molecules in TRAF-3 signaling, a yeast two-hybrid library was
screened with a full-length TRAF-3 construct. Nine independent TRAF-3 interacting
clones encoded fragments of p62 Nucleoporin (p62), a 522 amino acid (aa)
component of the nuclear pore central plug, that is known to bind karyopherin
beta/classical-NLS import factor complexes. The interaction of p62 with TRAF-3
was specific, since p62 failed to interact with TRAF-2, -4, -5, or -6. Deletional
analysis in yeast revealed that the p62:TRAF-3 interaction is mediated by a p62
carboxy (C)-terminal coiled-coil domain and TRAF-3's fifth zinc (Zn) finger and
coiled-coil domain. In human 293 T cells, recombinant TRAF-3 or p62 specifically
co-immunoprecipitates the other species. In addition, endogenous p62 co
precipitates over-expressed TRAF-3. The functional effects of over-expressing a
TRAF-3 binding fragment, p62(aa 336-522) were studied on NF-kappaB-dependent, or
control STAT1-dependent reporter activity in 293 T cells, either resting or after
stimulation by CD40 or IFN-gamma, respectively. Over-expression of p62(aa 336
522) induces NF-kappaB activation in resting cells and augments CD40-induced NF
kappaB activation, but has no effect on control STAT1 reporter activity, either
at baseline or after IFN-gamma induction. The finding that TRAF-3 binds p62,
suggests that TRAF-3 may serve as an adapter molecule at the nuclear membrane, in
addition to its known adapter function at the plasma membrane.
PMID- 10781839
TI - Complement-endothelial cell interactions: pathophysiological implications.
PMID- 10781838
TI - Restoration of thymic development in an Lck(-/-) thymoma overexpressing ZAP-70.
AB - Thymic development is strictly controlled by Src and Syk family protein tyrosine
kinases. The major players in this process are Lck and ZAP-70, which regulate
critical differentiation steps of thymopoiesis. Notwithstanding the critical role
of Lck and ZAP-70 in thymocyte development as compared to the related kinases Fyn
and Syk, a partial functional redundancy between members of the same family of
protein tyrosine kinases has emerged from studies on genetically manipulated
mouse models. Furthermore, a close functional interplay between Lck and ZAP-70 in
intracellular signaling has been shown to occur in thymocytes. Here we present
the characterization of a thymoma from an Lck(-/-) mouse, where the block in
thymocyte development is overcome and the transition between the CD4(-)CD8(-) and
CD4(+)CD8(+) stages is fully restored. Determination of the expression levels of
Fyn, ZAP-70 and Syk in thymocytes form the Lck(-/-) thymoma revealed high levels
of ZAP-70 overexpression and recovery of a specific subset of phosphoproteins as
compared to Lck(-/-) thymocytes. Hence ZAP-70 overexpression in thymocytes is
associated with recovery from the developmental arrest caused by the absence of
Lck, suggesting a role for ZAP-70 downstream of Lck in the maturation of
CD4(+)CD8(+) thymocytes.
PMID- 10781840
TI - Adeno-associated virus mediated gene transfer into primary rat brain neuronal and
glial cultures: enhancement with the pH-sensitive surfactant dodecyl 2-(1'
imidazolyl) propionate.
AB - This study evaluated the effects of a novel, pH-sensitive surfactant, dodecyl 2
(1'-imidazolyl) propionate (DIP), on cationic lipid mediated transfection in
primary rat brain neuronal and glial cultures. The cationic lipid complex
DOTAP/DOPE (1, 2-dioleoyl-3-trimethylammonium propionate and dioleoyl
phosphatidylethanolamine, respectively) was added over a range of concentrations
(0-120 microg/ml) with DNA concentration kept constant (1.6 microg/ml). The
neuron-specific enolase (NSE) and cytomegalovirus (CMV) promoters were found to
drive green fluorescent protein (GFP) expression in neuron-enriched and glial
cultures, respectively, using adeno-associated virus (AAV) derived constructs.
NSE-driven GFP expression was not observed in glial cultures. Addition of
DOTAP/DOPE increased transfection efficiency over a wide range of lipid
concentrations (5-50 microg/ml) keeping DNA concentration constant (1.6
microg/ml). Addition of DIP to the lipid/DNA complex increased maximum
transfection efficiencies in glial and neuronal cultures 2-3-fold. Transfection
efficiencies were at their maximum with a similar total lipid concentration (50
microg/ml) in both cell-types in the presence of DIP. Neuronal cultures were more
sensitive than glia to the toxic actions of DOTAP/DOPE, with or without DIP.
These results indicate that AAV-mediated gene-transfer to neurons and glia can be
facilitated by addition of a pH-sensitive surfactant to cationic liposome/DNA
complexes and that endosomal escape could be a limiting factor in transgene
expression.
PMID- 10781841
TI - GluR2 protein synthesis and metabolism in rat hippocampus following transient
ischemia and ischemic tolerance induction.
AB - In this study we have determined the metabolic half-life, protein synthesis and
expression of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)
receptor subunit GluR2 in the hippocampus of the living rat. Synthesized proteins
were pulse labeled in vivo using intracarotid infusion or intrahippocampal
injection of L-[(35)S] labeled amino acids, and the GluR2 protein
immunoprecipitated in order to measure the tracer incorporation at different
survival time-points. A limited time course study suggested a metabolic half-life
of 144 and 108 h in the CA1 region in control animals following carotid artery
infusion and intrahippocampal injection, respectively. Twenty-four hours
following a moderate ischemic insult, GluR2 protein synthesis was decreased
significantly in both the CA1 and DG/CA3 region, whereas the total protein
synthesis was decreased significantly only in the CA1 region. Twenty-four hours
following ischemic tolerance induction, a significant increase in GluR2
expression was found in the CA1 region using quantitative Western blotting, while
no change was found in the dentate gyrus (DG)/CA3 or in expression of GluR1
protein. Data from labeling experiments did not reveal the reason for the
increased amount of GluR2 in the CA1 region of the tolerant animals. This study
shows that following global ischemia the GluR2 synthesis is decreased both in the
CA1 and DG/CA3, which, together with the found GluR2 metabolic half-life,
contradict a selective loss of GluR2 protein as a triggering mechanism for the
delayed CA1 pyramidal cell death. Twenty-four hours following tolerance
induction, we found an increased GluR2 expression in the CA1 region, suggesting
that GluR2 plays a role in the acquisition of ischemic tolerance. Our study
suggests the ability of neurons to regulate the AMPA receptor subunit expression
through changes in protein synthesis and stability.
PMID- 10781842
TI - A frontal variant of Alzheimer's disease exhibits decreased calcium-independent
phospholipase A2 activity in the prefrontal cortex.
AB - A frontal variant of Alzheimer's disease (AD) has recently been identified on
neuropathological and neuropsychological grounds (Johnson, J.K., Head, E., Kim,
R., Starr, A., Cotman, C.W., 1999. Clinical and pathological evidence for a
frontal variant of Alzheimer Disease. Arch. Neurol. 56, 1233-1239). Frontal AD
differs strikingly from typical AD by the occurrence of neurofibrillary tangle
densities in the frontal cortex as high or higher than in the entorhinal cortex.
Since cerebrocortical membranes are commonly abnormal in Alzheimer's disease
(AD), we assayed frontal AD cases for enzymes regulating membrane phospholipid
composition. We specifically measured activity of phospholipase A2s (PLA2s) in
dorsolateral prefrontal and lateral temporal cortices of frontal AD cases (n=12),
which have respectively high and low densities of neurofibrillary tangles. In
neither cortical area was Ca(2+)-dependent PLA2 activity abnormal compared to
controls (n=12). In contrast, a significant 42% decrease in Ca(2+)-independent
PLA2 activity was found in the dorsolateral prefrontal, but not the lateral
temporal, cortex of the frontal AD cases. Similarly, the dorsolateral prefrontal
cortex, but not the lateral temporal cortex of the frontal AD cases suffered a
42% decrease in total free fatty acid content, though neither that decrease nor
those in any one species of free fatty acid was significant. The observed
biochemical changes probably occurred in neurons given (a) our finding that PLA2
activity of cultured human NT2 neurons is virtually all Ca(2+)-independent and
(b) the finding of others that nearly all Ca(2+)-independent PLA2 in brain gray
matter is neuronal. The decrease in Ca(2+)-independent PLA2 activity is not
readily attributable to Group VI or VIII iPLA2s since neither NT2N neurons nor
our brain homogenates were greatly inhibited by drugs potently suppressing those
iPLA2s. Decreased Ca(2+)-independent PLA2 activity in frontal AD may reflect a
compensatory response to pathologically accelerated phospholipid metabolism early
in the disorder. That could cause an early elevation of prefrontal free fatty
acids, which can stimulate polymerization of tau and thus promote the prefrontal
neurofibrillary tangle formation characteristic of frontal AD.
PMID- 10781843
TI - Negative allosteric modulators of AMPA-preferring receptors inhibit [(3)H]GABA
release in rat striatum.
AB - The effect of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), a
selective glutamate receptor agonist, on the release of previously incorporated
[(3)H]GABA was examined in superfused striatal slices of the rat. The slices were
loaded with [(3)H]GABA in the presence of beta-alanine (1 mM) and superfused with
Krebs-bicarbonate buffer containing nipecotic acid (0.1 mM) and aminooxyacetic
acid (0.1 mM) to inhibit GABA uptake and metabolism. AMPA (0.01 to 3 mM)
increased basal [(3)H]GABA outflow and nipecotic acid potentiated this effect.
The [(3)H]GABA releasing effect of AMPA was an external Ca(2+)-dependent process
in the absence but not in the presence of nipecotic acid. Cyclothiazide (0.03
mM), a positive modulator of AMPA receptors, failed to evoke [(3)H]GABA release
by itself, but it dose-dependently potentiated the [(3)H]GABA releasing effect of
AMPA. The AMPA (0.3 mM)-induced [(3)H]GABA release was antagonized by NBQX (0.01
mM) in a competitive fashion (pA(2) 5.08). The negative modulator of AMPA
receptors, GYKI-53784 (0.01 mM) reversed the AMPA-induced [(3)H]GABA release by a
non-competitive manner (pD'(2) 5.44). GYKI-53784 (0. 01-0.1 mM) also decreased
striatal [(3)H]GABA outflow on its own right, this effect was stereoselective and
was not influenced by concomitant administration of 0.03 mM cyclothiazide. GYKI
52466 (0. 03-0.3 mM), another negative modulator at AMPA receptors, also
inhibited basal [(3)H]GABA efflux whereas NBQX (0.1 mM) by itself was ineffective
in alteration of [(3)H]GABA outflow. The present data indicate that AMPA evokes
GABA release from the vesicular pool in neostriatal GABAergic neurons. They also
confirm that multiple interactions may exist between the agonist binding sites
and the positive and negative modulatory sites but no such interaction was
detected between the positive and negative allosteric modulators. Since GYKI
53784, but not NBQX, inhibited [(3)H]GABA release by itself, AMPA receptors
located on striatal GABAergic neurons may be in sensitized state and phasically
controlled by endogenous glutamate. It is also postulated that these AMPA
receptors are located extrasynaptically on GABAergic striatal neurons.
PMID- 10781844
TI - Differential stereoselectivity of D- and L-myo-inositol 1,2,4, 5
tetrakisphosphate binding to the inositol 1,4,5-trisphosphate receptor and 3
kinase.
AB - D- and L-myo-inositol 1,2,4,5-tetrakisphosphate (Ins(1,2,4,5)P(4)) were
investigated for their ability to bind to the D-myo-inositol 1, 4,5-trisphosphate
(Ins(1,4,5)P(3)) receptor in a bovine adrenal cortical membrane fraction, to
mobilize intracellular Ca(2+) stores in Xenopus oocytes, and to bind to the rat
brain Ins(1,4,5)P(3) 3-kinase overexpressed and purified in E. coli. In
competitive binding experiments with the Ins(1,4,5)P(3) receptor, D-Ins(1,2,4,
5)P(4) effectively displaced [(3)H]Ins(1,4,5)P(3) in a concentration-dependent
manner with a potency comparable to that of D-Ins(1,4,5)P(3), while L
Ins(1,2,4,5)P(4) was approximately 50-fold less effective than D-Ins(1,4,5)P(3)
and D-Ins(1,2,4,5)P(4). The DL-Ins(1,2,4,5)P(4) racemate bound to the
Ins(1,4,5)P(3) receptor with an apparent intermediate efficiency. Injection of D
Ins(1,2,4, 5)P(4) into oocytes evoked a chloride current dependent on
intracellular Ca(2+) mobilization in which the agonists ranked in a similar order
of potency as in the Ins(1,4,5)P(3) receptor binding. On the other hand, D
Ins(1,2,4,5)P(4) only inhibited the binding of [(3)H]Ins(1,4,5)P(3) to 3-kinase
very weakly with a markedly reduced potency compared to D-Ins(1,4,5)P(3),
indicating that D-Ins(1,2,4, 5)P(4) is not an effective competitor in the
phosphorylation of [(3)H]-Ins(1,4,5)P(3) by 3-kinase. The results, therefore,
clearly indicate that D-Ins(1,2,4,5)P(4) is as effective as D-Ins(1,4,5)P(3) in
the binding to the receptor but not 3-kinase, and access of Ins(1, 2,4,5)P(4)
over the Ins(1,4,5)P(3) receptor calls for stringent stereospecificity with D
Ins(1,2,4,5)P(4) being the active form in DL-Ins(1,2,4,5)P(4)-mediated Ca(2+)
mobilization.
PMID- 10781845
TI - Quinolinic acid lesion induces changes in rat striatal glutathione metabolism.
AB - Although the involvement of oxidative mechanisms in the cytotoxicity of
excitatory amino acids has been well documented, it is not known whether the
intrastriatal injection of quinolinic acid (QA) induces changes in glutathione
(GSH) metabolism. In this work, the activities of the enzymes GSH reductase
(GRD), GSH peroxidase (GPX), and GSH S-transferase (GST), as well as the GSH
content, were studied in the striatum, hippocampus, and frontal cortex of rats 1
and 6 weeks following the intrastriatal injection of QA (225 nmol). One group of
animals remained untreated. This lesion resulted in a 20% decrease in striatal
GRD activity at both the 1- and 6-week postlesion times, whereas GST exhibited a
30% activity increase in the lesioned striatum observable only 6 weeks after the
lesion. GPX activity remained unchanged. In addition, the QA injection elicited a
30% fall in GSH level at the 1-week postlesion time. GSH related enzyme
activities and GSH content from other areas outside the lesioned striatum were
not affected. GST activation could represent a beneficial compensatory response
to neutralize some of the oxidant agents generated by the lesion. However, this
effect together with the reduction in GRD activity could be the cause or a
contributing factor to the observed QA-induced deficit in GSH availability and,
consequently, further disrupt the oxidant homeostasis of the injured striatal
tissue. Therefore, these results provide evidence that the in vivo excitotoxic
injury to the brain might affect oxidant/antioxidant equilibrium by eliciting
changes in glutathione metabolism.
PMID- 10781846
TI - Footshock-induced changes in brain catecholamines and indoleamines are not
mediated by CRF or ACTH.
AB - Stressful treatments have long been associated with increased activity of brain
catecholaminergic and serotonergic neurons. An intracerebroventricular (icv)
injection of the corticotropin-releasing factor (CRF) also activates brain
catecholaminergic neurons. Because brain CRF-containing neurons appear to be
activated during stress, it is possible that CRF mediates the catecholaminergic
activation. This hypothesis has been tested by assessing the responses in brain
catecholamines and indoleamines to footshock in mice pretreated icv with a CRF
receptor antagonist, and in mice lacking the gene for CRF (CRFko mice).
Consistent with earlier results, icv administration of CRF increased catabolites
of dopamine and norepinephrine, but failed to alter tryptophan concentrations or
serotonin catabolism. A brief period of footshock increased plasma corticosterone
and the concentrations of tryptophan and the catabolites of dopamine,
norepinephrine and serotonin in several brain regions. Mice injected icv with 25
microg alpha-helical CRF(9-41) prior to footshock had neurochemical responses
that were indistinguishable from controls injected with vehicle, while the
increase in plasma corticosterone was slightly attenuated in some experiments.
CRFko mice exhibited neurochemical responses to footshock that were
indistinguishable from wild-type mice. However, whereas wild-type mice showed the
expected increase in plasma corticosterone, there was no such increase in CRFko
mice. Similarly, hypophysectomized mice also showed normal neurochemical
responses to footshock, but no increase in plasma corticosterone. Hypophysectomy
itself elevated brain tryptophan and catecholamine and serotonin metabolism.
Treatment with ACTH icv or peripherally failed to induce any changes in cerebral
catecholamines and indoleamines. These results suggest that CRF and its
receptors, and ACTH and other pituitary hormones, are not involved in the
catecholamine and serotonin responses to a brief period of footshock.
PMID- 10781847
TI - Sustained depolarisation induces changes in the extracellular concentrations of
purine and pyrimidine nucleosides in the rat thalamus.
AB - ATP and adenosine are well-known neuroactive compounds. Other nucleotides and
nucleosides may also be involved in different brain functions. This paper reports
on extracellular concentrations of nucleobases and nucleosides (uracil,
hypoxanthine, xanthine, uridine, 2'-deoxycytidine, 2'-deoxyuridine, inosine,
guanosine, thymidine, adenosine) in response to sustained depolarisation, using
in vivo brain microdialysis technique in the rat thalamus. High-potassium
solution, the glutamate agonist kainate, and the Na(+)/K(+) ATPase blocker
ouabain were applied in the perfusate of microdialysis probes and induced release
of various purine and pyrimidine nucleosides. All three types of depolarisation
increased the level of hypoxanthine, uridine, inosine, guanosine and adenosine.
The levels of measured deoxynucleosides (2'-deoxycytidine, 2'-deoxyuridine and
thymidine) decreased or did not change, depending on the type of depolarisation.
Kainate-induced changes were TTX insensitive, and ouabain-induced changes for
inosine, guanosine, 2'-deoxycytidine and 2'-deoxyuridine were TTX sensitive. In
contrast, TTX application without depolarisation decreased the extracellular
concentrations of hypoxanthine, uridine, inosine, guanosine and adenosine. Our
data suggest that various nucleosides may be released from cells exposed to
excessive activity and, thus, support several different lines of research
concerning the regulatory roles of nucleosides.
PMID- 10781848
TI - The introduction of new vaccines into developing countries II. Vaccine financing.
AB - The development of new vaccines for important childhood diseases presents an
unparalleled opportunity for disease control but also a significant problem for
developing countries: how to pay for them. To help address this problem, the
William H. Gates Foundation has established a Global Fund for Children's Vaccine.
In this paper, we discuss the allocation of this and other similar funds, which
we call Global Funds. We propose that allocation of the Global Funds to
individual countries be guided in part by a Vaccine Procurement Baseline (VPB).
The VPB would set a minimum of 0.01% of gross national product (GNP) as an amount
each developing country would devote to its own vaccine procurement. When this
amount is not sufficient to procure the vaccines needed by a developing country,
the Global Funds would meet the shortfall. The amount required of donors to
maintain the Global Funds would be about $403 million per year for both existing
EPI vaccines as well as for a hypothetical group of five new vaccines costing
$0.50 per dose and requiring three doses per child. Including program costs, poor
developing countries currently spend about 0.13% of GNP on EPI immunizations. In
contrast, the United States, as one example donor country, spends about 0.035% of
GNP for childhood immunization including several new vaccines. This paper
analyzes the Global Funds requirements for hepatitis B and Haemophilus influenzae
type b (Hib) vaccines. After a ramp-up period, needier countries would eventually
require about $62 million for hepatitis B and $282 million for Hib at current
prices. Various additional criteria could be used to qualify countries for
participation in the Global Funds.
PMID- 10781849
TI - Immune responses induced by recombinant BCG strains according to level of
production of a foreign antigen: malE.
AB - A variety of viral, bacterial and parasitic antigens have been expressed in BCG
and the capacity of these recombinant bacteria to induce immune responses has
been well documented. However, little is known about the parameters influencing
the induction of immune responses by recombinant BCG (rBCG), such as level of
production and localization of the recombinant antigen. In the present study, we
have constructed several rBCG strains expressing the malE gene from Escherichia
coli which is either secreted or targeted to the cytoplasm or plasma membrane.
Expression of malE was quantified by ELISA and localization was analyzed by flow
cytometry. Even when using the same promoter, levels of cytoplasmic or membrane
MalE production were far less than those from secreting strains using either
mycobacterial or E. coli secretion signals. Stronger and more rapid immune
responses were induced by rBCG strains with the highest levels of secreted MalE
compared to cytoplasmic or membrane constructs, including both good humoral and
proliferative responses in BALB/c, C57BL6 and even C3H mice, previously shown to
be poor MalE responders. These results suggest that the levels of foreign antigen
production play an important role in the induction of immune responses by rBCG
strains.
PMID- 10781851
TI - Seroconversion and duration of immunity after vaccination against group C
meningococcal infection in young children.
AB - An increase in the incidence of group C meningococcal disease was observed in the
Murcia Region (Spain) during 1996-1997. In September 1997, a massive vaccination
campaign was implemented among the population aged 18 months to 19 years. The aim
of this study was to assess the seroconversion rate of children aged 18-59 months
and the persistence of immune response 1 year after vaccination. A total of 296
children were included. Blood samples were obtained before vaccination and 1
month and 1 year after vaccination. Three point seven percent of the children had
bactericidal antibody titres of >/=1:8 before vaccination. One month after
vaccination seroconversion was 63.7%, with a growing trend related to age at
vaccination (p<0.0001). The increase in antibody titres was shown to be
quantitatively greater above the age of 36 months (p<0.0001). One year after
vaccination only 4.3% of the children who initially seroconverted still had
bactericidal activity. Seroconversion in children under 5 increases with age but
antibodies decline rapidly in the year following vaccination.
PMID- 10781850
TI - Influence of live respiratory syncytial virus priming on the immune response
generated by a recombinant vaccine candidate, BBG2Na.
AB - Respiratory syncytial virus is one of the major respiratory pathogens for infants
and immunocompromized children. With the exception of young children, all the
population has encountered RSV and is seropositive. Recent reports have
demonstrated however that the virus also affects the elderly and represents a
major cause of illness associated with an excess of morbidity and mortality. We
have generated a recombinant RSV vaccine, BBG2Na, which is highly protective in
rodents against RSV infection. The aim of this study was to evaluate the ability
of the vaccine to increase anti-RSV protection in RSV-primed mice and to
characterize the induced immune responses. Immunization with BBG2Na increased the
anti-RSV-A serum antibody titers of RSV-primed mice with induction of both IgG1
and IgG2a antibodies attesting for a mixed Th response. Moreover, the level of
the induced anti-G2Na antibodies was greater in seropositive mice. Finally, sera
from RSV-primed mice displayed a higher protective efficacy after transfer into
naive mice following subsequent immunization with BBG2Na than sera of mice
immunized with RSV-A only. Our results demonstrate that BBG2Na is immunogenic and
increases the protective efficacy of serum antibodies in RSV-primed mice; they
support the possibility of performing clinical trials in the seropositive human
population.
PMID- 10781852
TI - Predictive factors for the neutralizing antibody response following pre-exposure
rabies immunization: validation of a new booster dose strategy.
AB - A prospective cohort of 312 subjects who received pre-exposure rabies
immunization and who were monitored serologically with a 10-year follow-up was
assessed using multivariate analysis. The aim was to propose a new booster dose
strategy by identifying predictive factors for the durability of the neutralizing
antibody response. Evaluation bore on several factors relating to: (1)
demographic characteristics: age, gender; (2) vaccines: type of vaccine (HDCV or
PVRV), injection regimen (D0-D28-D365 or D0-D7-D28-D365) and vaccine lots'
antigenic potency; and (3) resulting antibody titers. Logistic regression
analysis enabled the authors to establish a predictive model for immunized
subjects' serological status at ten years' follow-up expressed as a P probability
for seroreversion (antibody titer <0.5 IU/ml). Highly significant factors were
the immunization regimen, the type of vaccine used and the antibody titer at
D379. A P value <0.4 identified subjects as "good" responders who were sure to be
have satisfactory antibody titers at 10 years and who required a single booster
dose every 10 years. A P value >/=0.4 identified subjects as "poor" responders in
whom a specific follow-up and booster dose strategy is proposed. This new
immunization strategy could at least be applied to subjects with a frequent risk
of exposure, as defined by institutional recommendations. This new immunization
strategy should nevertheless undergo an external validation and a cost
effectiveness evaluation.
PMID- 10781853
TI - Antibody responses to Yersinia pestis F1-antigen expressed in Salmonella
typhimurium aroA from in vivo-inducible promoters.
AB - Attenuated mutants of Salmonella typhimurium are being evaluated as delivery
systems for a variety of heterologous vaccine antigens. Gene promoters which are
induced in vivo can direct the stable expression of genes encoding these
antigens. We have investigated the utility of the phoP, ompC, pagC and lacZ gene
promoters for expression of the Y. pestis F1-antigen in S. typhimurium SL3261
(aroA). After i.g. (intragastric) dosing the highest level of spleen colonisation
was found with recombinant Salmonella expressing F1-antigen from the phoP gene
promoter, and this recombinant was most effective in inducing serum and mucosal
antibody responses. The use of the pagC gene promoter to direct expression of F1
antigen resulted in the induction of serum and mucosal antibody responses even
though the recombinant Salmonella were unable to colonise spleen tissues
suggesting that colonisation of these tissues is not essential for the induction
of antibody responses.
PMID- 10781854
TI - Further development of the Helicobacter pylori mouse vaccination model.
AB - Immunisation against Helicobacter infection in mouse models has thus far produced
neither complete protection against the bacteria, nor a complete prevention of
the associated gastritis. This study aimed firstly to compare the sensitivities
of the various methods used to assess H. pylori infection in the mouse model, and
secondly to develop the experimental design to induce a more effective immunity,
aimed at further reducing bacterial burden in the gastric tissue. Various mouse
strains were prophylactically immunised with whole bacterial sonicate and cholera
toxin before challenge with H. pylori-SS1. The relative sensitivities of the
urease assay, histological assessment and the colony forming assay to detect
levels of H. pylori colonisation were compared. Comparisons of different antigen
doses and different timecourses of immunisation were performed. The colony
forming assay was found to be far more sensitive than either the urease assay or
histological assessment for determining the protective efficacies of
immunisation. Mice which had 10(5) H. pylori per gram of stomach by colony assay
were negative by histology and urease. Lower doses of whole cell sonicate were
more protective than high doses and more effective immunisation was achieved by
leaving at least 3 weeks between immunisation instead of weekly immunisations. In
conclusion, for assessment of H. pylori colonisation in the mouse model, the
colony forming assay should be used. The experimental protocol for immunisation
has been altered to produce a significant improvement in protection. However,
full protection has still not yet been achieved and more work is still required.
PMID- 10781855
TI - Immunogenicity and reactogenicity of a group C meningococcal conjugate vaccine
compared with a group A+C meningococcal polysaccharide vaccine in adolescents in
a randomised observer-blind controlled trial.
AB - This study evaluated the immunogenicity and reactogenicity of a group C
meningococcal conjugate vaccine (MenC) compared with a group A+C meningococcal
polysaccharide vaccine (MenPS) in healthy adolescents. Subjects were randomised
to receive one dose of either MenC (n=92) or MenPS (n=90). Group C meningococcal
IgG antibody concentrations and bactericidal titres were higher in the MenC group
than the MenPS group at 1 month (22.8 U/ml vs 4.0 U/ml, p<0.001, and 87 vs 20,
p<0.001, respectively) and 12 months (6.1 U/ml vs 3.0 U/ml, p<0.001, and 81.3 vs
20.2, p<0.001, respectively). No differences in post immunisation reaction rates
were noted between the two vaccinated groups. This study demonstrated the safety
and enhanced immunogenicity of the candidate meningococcal conjugate vaccine as
compared with the licensed polysaccharide vaccine in adolescents.
PMID- 10781856
TI - Increasing the potency of MHC class II-presented epitopes by linkage to Ii-Key
peptide.
AB - We previously found that peptide Ii77-92 from the immunoregulatory Ii protein
significantly enhances the binding of antigenic peptides to MHC class II
molecules. Now a series of hybrids have been constructed linking LRMK, the active
core region of the Ii77-92 peptide, to an antigenic epitope of cytochrome C. In
vitro T cell hybridoma stimulation by some of these hybrids is up to 250 times
more potent than by the antigenic peptide. The biological activities of the
hybrids were tested in terms of length and composition of the linker. Simple
spacers containing a polymethylene bridge (-HN-CH(2)-CH(2)-CH(2)-CH(2)-CO(2)-)
were fully active in these hybrids which can enhance vaccination with MHC class
II-presented epitopes.
PMID- 10781857
TI - A possible explanation for the discrepancy between ELISA and neutralising
antibodies to tetanus toxin.
AB - The structure and protective activity of tetanus antibodies elicited in rabbits
after whole-cell pertussis diphtheria-tetanus vaccine (DTPw) vaccination was
studied. ELISA antibody levels and toxin neutralisation activity (TNT) were
measured in individual serum samples. The ratio of symmetric and asymmetric
(functionally monovalent) IgG molecules was determined by concanavalin A (Con A)
chromatography. This test is based on the fact that the carbohydrate group
responsible for the molecular asymmetry has high affinity for the lectin Con A.
Asymmetric molecule ratio was observed to increase with immunisation time, as
well as differences between TNT and ELISA levels. All serum samples were
overestimated by ELISA as compared to TNT assay, in line with the markedly higher
proportion of asymmetric molecules which have lower toxin neutralising activity.
Protective levels could not be predicted reasonably from ELISA results below 0.
222 IU/ml, because this methodology fails to discriminate between both types of
antibodies and only an in vivo serum neutralisation procedure (TNT) reflects the
true neutralising serum activity.
PMID- 10781858
TI - Safety and immunogenicity of an oral, inactivated enterotoxigenic Escherichia
coli plus cholera toxin B subunit vaccine in Bangladeshi adults and children.
AB - We have compared the B cell responses evoked in Bangladeshi, adults (n=11, median
age 25 years) and children (n=21, median age 4.5 years), 7 days after intake of
each of two doses of an oral, inactivated enterotoxigenic Escherichia coli (ETEC)
vaccine composed of formalin-killed ETEC strains expressing the colonization
factors, CFA/I, CFA/II and CFA/IV together with 1 mg of recombinant cholera toxin
B-subunit (rCTB). The vaccine was well tolerated and only gave rise to negligible
side effects. Peak antibody-secreting cell (ASC) response of the IgA isotype were
seen 7 days after the first dose of the vaccine. The ASC responses to the
different colonization factors (CFs) increased from a 29- to 46-fold (responder
frequency 90-100%) in the adults and 13- to 24-fold (responder frequency 67-90%)
in the children. The IgA-ASC response to rCTB also peaked after the first dose in
the adults (426-fold, responder frequency 100%) and the children (46-fold,
responder frequency 95%). Increased IgA antibody levels against CFA/I as well as
IgA and IgG antibody levels to rCTB were seen in plasma after immunisation. About
86% of the children and 80% of the adults responded with faecal antibodies to
rCTB, whereas about 67% of both groups responded to CFA/I. These results show
that a single dose of the ETEC vaccine may elicit significant mucosal immune
responses in both children and adults residing in an ETEC-endemic country such as
Bangladesh.
PMID- 10781859
TI - Induction of innate immunity by nasal influenza vaccine administered in
combination with an adjuvant (cholera toxin).
AB - Inactivated influenza vaccine was administered intranasally to BALB/c mice
together with an adjuvant (cholera toxin B subunit [CTB] supplemented with a
trace amount of the whole toxin, CTB*) and its ability to induce innate immunity
and confer protection against influenza was examined. Nasal wash virus titres 3
days after inoculation of homologous viruses were measured as an index of the
ability of the vaccine to confer protection in mice immunized with either CTB*
combined vaccine or CTB* alone 1-21 days previously. The results were as follows.
(1) Partial but significant reduction of the nasal-wash virus titres (prevention)
was detected beginning 3 days after the vaccination, that is, 2 days earlier than
the appearance of both virus-specific antibody-forming cells (AFCs) in the nasal
associated lymphoid tissue (NALT) and virus-specific IgA antibody responses in
the nasal washes of mice immunized with the CTB*-combined vaccine. (2) The
protection, detected on day 3 and peaking on day 5 but lost by day 21, was also
conferred in mice immunized with CTB* alone. (3) The non-specific prevention was
detected at doses of more than 0.3 microg of CTB*/mouse. (4) The nonspecific
protection beginning 3 days after the immunization involved the enhanced
expression of cytokine mRNAs (IL-15 and IL-18), considered responsible for
natural killer (NK) cell activation, by the non-T cell populations in the NALT.
(5) Normal NALT cells, when cultured in vitro with CTB*, secreted IL-1beta within
a few hours in culture. These results demonstrate that the CTB*-combined vaccine,
when given intranasally into mice, can confer nonspecific protection against
influenza beginning 3 days after the vaccination and that CTB* also possessed
this ability to confer protection non-specifically and temporarily by inducing
the secretion of IL-1beta, one of the most important cytokines that initiates
both innate and adaptive immunity, and also NK cell activity.
PMID- 10781860
TI - Effective mucosal immunization against respiratory syncytial virus using purified
F protein and a genetically detoxified cholera holotoxin, CT-E29H.
AB - We exploited the powerful adjuvant properties of cholera holotoxin (CT) to create
a mucosally administered subunit vaccine against respiratory syncytial virus
(RSV). A genetically detoxified mutant CT with an E to H substitution at amino
acid 29 of the CT-A1 subunit (CT-E29H) was compared to wild type CT for toxicity
and potential use as an intranasal (IN) adjuvant for the natural fusion (F)
protein of RSV. When compared to CT the results demonstrated that: (1) CT-E29H
binding to GM1 ganglioside was equivalent, (2) ADP-ribosylation of agmatine was
11.7%, and (3) toxicity was attenuated in both Y-1 adrenal (1.2%) and patent
mouse gut weight assays. IN vaccination with F protein formulated with CT-E29H
induced serum anti-CT and anti-F protein antibodies that were comparable to those
obtained after vaccination with equivalent doses of CT. Vaccinations containing
CT-E29H at doses of 0.1 microg were statistically equivalent to 1.0 microg in
enhancing responses to F protein. Antigen-specific mucosal IgA and anti-RSV
neutralizing antibodies were detected in nasal washes and sera, respectively, of
mice that had received F protein and 0.1 or 1.0 microg of CT-E29H. Anti-F protein
IgA was not detected in the nasal washes from mice IN vaccinated with 0.01 microg
CT-E29H or IM with F protein adsorbed to AlOH adjuvant. In addition, the
formulation of purified F protein and CT-E29H (0.1 and 1.0 microg) facilitated
protection of both mouse lung and nose from live RSV challenge. Collectively, the
data have important implications for vaccine strategies that use genetically
detoxified mutant cholera holotoxins for the mucosal delivery of highly purified
RSV antigens.
PMID- 10781861
TI - Influence of administration dose and route on the immunogenicity and protective
efficacy of BBG2Na, a recombinant respiratory syncytial virus subunit vaccine
candidate.
AB - The immunogenicity and protective efficacy of BBG2Na, a novel recombinant
respiratory syncytial virus subunit vaccine candidate, was assessed in BALB/c
mice under various conditions of dose, administration route and number of
immunisations. A single intra-peritoneal (i.p.) dose of 2 microg, or two doses of
0.2 microg, were sufficient to induce elevated RSV-A serum antibodies and
sterilising lung protective immunity. Serum antibody titres were significantly
boosted following second immunisations, but not a third. Of three routes of
immunisation, i.p. induced the highest RSV-A antibody titres, followed in
efficacy by the intra-muscular (i. m.) and subcutaneous (s.c.) routes.
Nonetheless, all three routes induced comparable and sterilising lung protection.
In contrast, upper respiratory tract protection was observed only after i.p.
vaccination, although significant viral titre reductions were evident following
i.m. or s.c. immunisations. Interestingly, Pepscan analyses indicated that
antibody epitope usage was highest in i.p. and lowest in i.m. immunised mice,
respectively. Nonetheless, all routes resulted in antibody responses to known
lung protective epitopes (protectopes). Thus, the prevention of serious lower
respiratory tract disease, the principle goal of a RSV vaccine, but not URT
infection, is dose dependent but unlikely to be influenced by the route of BBG2Na
administration.
PMID- 10781862
TI - Partial protection to respiratory syncytial virus (RSV) elicited in mice by
intranasal immunization using live staphylococci with surface-displayed RSV
peptides.
AB - A live bacterial vaccine-delivery system based on the food-grade bacterium
Staphylococcus carnosus was used for delivery of peptides from the G glycoprotein
of human respiratory syncytial virus, subtype A (RSV-A). Three peptides,
corresponding to the G protein amino acids, 144-159 (denoted G5), 190-203 (G9)
and 171-188 (G4 S), the latter with four cysteine residues substituted for
serines, were expressed by recombinant means as surface-exposed on three
different bacteria, and their surface accessibility on the bacteria was verified
by fluorescence-activated cell sorting (FACS). Intranasal immunization of mice
with the live recombinant staphylococci elicited significant anti-peptide as well
as anti-virus serum IgG responses of balanced IgG1/IgG2a isotype profiles, and
upon viral challenge with 10(5) tissue culture infectious doses(50) (TCID(50)),
lung protection was demonstrated for approximately half of the mice in the G9 and
G4 S immunization groups. To our knowledge, this is the first study in which
protective immunity to a viral pathogen has been evoked using food-grade bacteria
as vaccine-delivery vehicles.
PMID- 10781863
TI - The induction of systemic and mucosal immune responses to antigen-adjuvant
compositions administered into the skin: alterations in the migratory properties
of dendritic cells appears to be important for stimulating mucosal immunity.
AB - The properties of various vaccine-adjuvant formulations that are capable of
inducing both systemic and common mucosal immunity subsequent to their
intradermal administration are described. Effective mucosal adjuvants, including
bacterial toxins, chemical enhancers of cyclic AMP, and the active form of
vitamin D3, all shared the ability to promote dendritic cell migration from the
skin to Peyer's patches subsequent to antigen induced maturation. Our data
suggests that skin dendritic cells may function as effective antigen presenting
cells for the induction of mucosal immune responses, if microenvironmental
conditions are appropriately manipulated subsequent to their stimulation by
antigen.
PMID- 10781865
TI - In honour of the past European editor: K.J. Netter.
PMID- 10781866
TI - Studies on pyrazinoylguanidine: a novel antihypertensive, hypoglycemic and
lipolytic drug intended for adjunctive use in hypertensive patients with type 2
diabetes mellitus.
AB - Herein are described the development and certain properties of a new drug,
pyrazinoylguanidine (PZG), intended for use as an adjunct in the treatment of
hypertensive patients with type 2 diabetes, formerly called noninsulin dependent
diabetes mellitus. PZG is an analog of the potassium sparing diuretic, amiloride.
However, in diabetic patients, amiloride exacerbates hyperglycemia and
hyperlipidemia, whereas PZG reduces them. In several studies, PZG not only
reduced elevated blood pressure in subjects with essential hypertension, but also
downregulated the glucose fatty acid cycle in hypertensive patients with type 2
diabetes. PZG was well tolerated in all patients, as well as in normal subjects
whose blood pressures and glucose metabolism were unaffected by PZG. However, in
normal subjects made hyperglycemic by giving them hydrochlorothiazide,
coadministration of PZG returned blood glucose concentrations to normal.
Mechanisms for these effects of PZG in human subjects were investigated in both
normal Sprague-Dawley rats and rats made diabetic with streptozotocin (STZ). In
isolated rat adipocytes stimulated with theophylline, PZG downregulated both
lipolysis and cyclic AMP concentrations. PZG, as well as insulin, increased
adipose cyclic nucleotide phosphodiesterase activity, whereas theophylline
reduced it. In perfused rat liver, PZG decreased gluconeogenesis and cyclic AMP
concentrations. Collectively, these studies illustrate how the side effects
(toxicity) of certain drugs, such as the tendency of thiazide diuretics to cause
hyperglycemia and hyperlipidemia, can be modulated and even reversed by slight
changes in the chemical structure of the molecule, specifically by removal of the
3,5-diamino and 6-chloro substituents on the benzene ring of amiloride to produce
PZG.
PMID- 10781864
TI - Development of a multi-specificity opsonophagocytic killing assay.
AB - The opsonophagocytic-killing assay (OPKA) is one of the primary surrogate assays
for evaluating the pneumococcal capsular polysaccharide-protein conjugates under
development as vaccines. Because each vaccine contains seven or more different
conjugates, multiple OPKA must be performed on each serum. Moreover, the large
number of assays can deplete serum samples from infants. To reduce the amount of
serum and effort required to conduct OPKA we developed a multi-specificity OPKA
using antibiotic resistant pneumococci. Equal numbers of optochin-resistant
serotype 6B and streptomycin-resistant 19F pneumococci were used as the target
bacteria. Surviving bacteria of each serotype were enumerated by plating on agar
containing the appropriate antibiotic. In an examination of 25 immune sera the
results obtained with this new assay correlated well with those obtained when
bacterial targets were examined individually. By using additional antibiotic
resistance markers, more than two specificities can be examined in a single
assay.
PMID- 10781867
TI - Use of suppression-PCR subtractive hybridisation to identify genes that
demonstrate altered expression in male rat and guinea pig livers following
exposure to Wy-14,643, a peroxisome proliferator and non-genotoxic
hepatocarcinogen.
AB - Understanding the genetic profile of a cell at all stages of normal and
carcinogenic development should provide an essential aid to developing new
strategies for the prevention, early detection, diagnosis and treatment of
cancers. We have attempted to identify some of the genes that may be involved in
peroxisome-proliferator (PP)-induced non-genotoxic hepatocarcinogenesis using
suppression PCR subtractive hybridisation (SSH). Wistar rats (male) were chosen
as a representative susceptible species and Duncan-Hartley guinea pigs (male) as
a resistant species to the hepatocarcinogenic effects of the PP, [4-chloro-6-(2,3
xylidino)-2-pyrimidinylthio] acetic acid (Wy-14,643). In each case, groups of
four test animals were administered a single dose of Wy-14,643 (250 mg/kg per day
in corn oil) by gastric intubation for 3 consecutive days. The control animals
received corn oil only. On the fourth day the animals were killed and liver mRNA
extracted. SSH was carried out using mRNA extracted from the rat and guinea pig
livers, and used to isolate genes that were up and downregulated following Wy
14,643 treatment. These genes included some predictable (and hence positive
control) species such as CYP4A1 and CYP2C11 (upregulated and downregulated in rat
liver, respectively). Several genes that may be implicated in
hepatocarcinogenesis have also been identified, as have some unidentified
species. This work thus provides a starting point for developing a molecular
profile of the early effects of a non-genotoxic carcinogen in sensitive and
resistant species that could ultimately lead to a short-term assay for this type
of toxicity.
PMID- 10781868
TI - Bioflavonoids: selective substrates and inhibitors for cytochrome P450 CYP1A and
CYP1B1.
AB - Interactions of six naturally occurring flavonoids (acacetin, diosmetin,
eriodictyol, hesperetin, homoeriodictyol, and naringenin) with human cytochrome
P450 (CYP1) enzymes were studied. The flavones acacetin and diosmetin were potent
inhibitors of ethoxyresorufin O-dealkylase (EROD) activity of CYP1A and CYP1B1.
Hydroxy and/or methoxy substitutions at the 3' and 4' positions in the flavonoid
structures were the major factors involved in conveying selectivity for the
different cytochrome P450 enzymes. Eriodictyol, homoeriodictyol and naringenin
were very poor inhibitors of human CYP1A EROD activity (IC(50)4 microM).
Hesperetin and homoeriodictyol selectively inhibited human CYP1A1 and CYP1B1.
Only homoeriodictyol selectively inhibited human CYP1B1 (IC(50) 0.24 microM).
Hesperetin was O-demethylated by both human CYP1A1 and 1B1 to eriodictyol, which
was then further metabolized by the same enzymes. Hesperetin was not metabolized
by human CYP1A2 or CYP3A4.
PMID- 10781869
TI - Estimation of human exposure to styrene and ethylbenzene.
AB - In the present studies, human exposure to styrene and to ethylbenzene (EB) is
assessed on the basis of literature data. Total styrene and total EB exposure
result from inhalation and from food intake. Styrene and EB inhaled represent the
greatest proportion of the total intake. Styrene and EB content in food is mainly
caused by migration from polymer packaging material. The daily styrene exposure
is estimated to range from 18.2 to 55.2 microg/person, corresponding to an annual
exposure of 6.7 to 20.2 mg/person. The daily EB exposure is estimated to be about
130 microg/person, corresponding to an annual exposure of 46 mg/person. Cigarette
smoking is another important factor for styrene and EB intake by smokers.
PMID- 10781870
TI - Density-dependent growth of normal and nodular hepatocytes.
AB - To elucidate factors responsible for altered proliferation of preneoplastic
hepatocytes in rat hepatocarcinogenesis in vivo, EGF-stimulated DNA synthesis of
normal and nodular hepatocytes in primary culture was studied. In addition, the
influence of 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) was investigated to
clarify whether this potent tumor promoter differentially affects normal and
nodular hepatocyte cultures. Unexpectedly it was found that in nodular
hepatocytes spontaneous and EGF-stimulated DNA synthesis was enhanced with
increasing cell density while DNA synthesis was inhibited in dense cultures of
normal hepatocytes. Mitogenic responses were detected both by [3H]thymidine
incorporation into DNA and by 5-bromo-2'-deoxyuridine labeling indices. TCDD (1
nM) acted as a mitoinhibitor both in normal and in nodular hepatocytes. The
results suggest marked differences in growth behavior of nodular versus normal
hepatocyte cultures probably due to paracrine stimulation by growth factors and
altered cell-cell interaction.
PMID- 10781871
TI - Effect of selenium supplementation on the activities of glutathione metabolizing
enzymes in human hepatoma Hep G2 cell line.
AB - Cell culture is an important tool for studying injury to cells exposed to
oxidative stress. The human hepatoblastoma derived Hep G2 cells retain their
morphology and most of their function in culture and are therefore widely used as
an in vitro model of human hepatocytes. Conventional cell culture media are
deficient in selenium, which is essential for activation of glutathione
peroxidase (GPx), a key enzyme in the defense against oxidative stress.
Supplementation of the culture media with 1 microM sodium selenite increased the
activities of total GPx by threefold and the selenium-dependent GPx by fourfold
as compared to cells cultured in control media. The non-selenium-dependent GPx
activity was unchanged. The activities of the other glutathione (GSH)-related
enzymes were practically unchanged despite a tendency toward elevation. The
activities of oxidized glutathione (GSSG) reductase and catalase increased by
22.4 and 27.4%, respectively. These relatively small increases did not carry
statistical significance. Supplementation of tissue culture media with selenium
may prove important, particularly for cell protection against oxidative stress.
PMID- 10781873
TI - Molecular and structural aspects of xenobiotic carbonyl metabolizing enzymes.
Role of reductases and dehydrogenases in xenobiotic phase I reactions.
AB - The major metabolic pathways involved in synthesis and disposition of carbonyl
and hydroxyl group containing compounds are presented, and structural and
functional characteristics of the enzyme families involved are discussed. Alcohol
and aldehyde dehydrogenases (ADH, ALDH) participate in oxidative pathways,
whereas reductive routes are accomplished by members of the aldo-keto reductase
(AKR), short-chain dehydrogenases/reductases (SDR) and quinone reductase (QR)
superfamilies. A wealth of biochemical, genetic and structural data now
establishes these families to constitute important phase I enzymes.
PMID- 10781872
TI - Heterogeneity of 11beta-hydroxysteroid dehydrogenase type 1/microsomal carbonyl
reductase (11beta-HSD/CR) in guinea pig tissues. Purification of the liver form
suggests modification in the cosubstrate binding site.
AB - 11beta-hydroxysteroid dehydrogenase (11beta-HSD) and xenobiotic carbonyl
reductase activities were determined in guinea pig tissue microsomes. The data
indicate the presence of a NADP(H) dependent form, distinct from the known type I
isozyme. Purification of 11beta-HSD-1 from liver microsomes resulted in two
distinct peaks, resolved by dye-ligand chromatography, indicating differences in
the cosubstrate binding site. Immunoblot analysis using anti 11beta-HSD-1
antibodies reveals the presence of similar structural determinants between the
enzyme forms. Both have an apparent molecular mass of 32 kDa, suggesting protein
modifications occurring in the type 1 isozyme which account for the differences
in chromatographic behaviour.
PMID- 10781874
TI - Use of precision-cut tissue slices in organ culture to study metabolism of 4
(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(methylnitrosamino)-1-(3
pyridyl)-1-butanol (NNAL) by hamster lung, liver and kidney.
AB - The pharmacokinetics of in vitro metabolism of the tobacco-specific nitrosamine,
4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK; concentration range 0.03-250
microM) and its proximal metabolite, 4-(methylnitrosamino)-1-(3-pyridyl)-1
butanol (NNAL; 0.04-250 microM), were determined in Syrian golden hamster liver,
lung, and kidney tissue slices in organ culture under identical experimental
conditions. In the lung, a target organ for NNK animal carcinogenesis, total NNK
metabolism was relatively low (maximum 23%) and oxidative metabolism by alpha
hydroxylation to DNA-reactive intermediates accounted for 13-31% of metabolism.
The liver, a non-target organ for NNK carcinogenesis, showed the highest capacity
to metabolise NNK (total metabolism 80%), and alpha-hydroxylation accounted for
12-25% of metabolism. The kidney, another non-target organ, also showed a low
capacity for NNK metabolism (maximum 32%) and alpha-hydroxylation accounted for
<3% of metabolism. Detoxification of NNK by pyridyl N-oxidation was similar in
lung (5-22%) and liver (5-23%), and negligible in kidney (<2%), while carbonyl
reduction of NNK to NNAL was greatest in the kidney (95-100%), followed by liver
(59-79%) and lung (47-81%). NNAL is devoid of biological activity in the hamster
and total metabolism was about tenfold lower than that of NNK in all tissues
(<13% liver; <4% lung and kidney). In the liver, alpha-hydroxylation was the
predominant pathway of NNAL metabolism at almost all concentrations (31-68% of
total metabolism), whereas N-oxidation prevailed in the kidney (47-68%). In the
lung, a concentration dependent decrease in the relative amount of alpha
hydroxylation (23-72%) with increasing NNAL concentrations occurred at the
expense of N-oxidation (25-72%). Little or no metabolism of NNAL back to NNK was
evident in any tissue.
PMID- 10781875
TI - Induction of cytochrome P450 2B1-mRNA and pentoxyresorufin O-depentylation after
exposure of precision-cut rat liver slices to phenobarbital.
AB - Precision-cut rat liver slices were prepared from male Wistar rats with a
Krumdieck slicer and cultured in William's medium E for up to 24 h. In untreated
control slices, CYP2B1-mRNA concentration, which was quantified by competitive RT
PCR, did not decrease during this time. After exposure of the slices to 100
microM phenobarbital, CYP2B1-mRNA increased by about 10- or 60-fold after 6 or 24
h, respectively. The extent of this in vitro induction was similar to that after
in vivo administration of 60 mg/kg phenobarbital. Pentoxyresorufin O
depentylation (PROD) was also inducible in vitro after 24 h, but to a lesser
extent than the corresponding CYP-mRNA. Precision-cut liver slices proved to be a
simple and reliable in vitro system for the sensitive detection of an induction
by phenobarbital.
PMID- 10781876
TI - Effects of cotinine at cholinergic nicotinic receptors of the sympathetic
superior cervical ganglion of the mouse.
AB - Nicotine, the principal alkaloid in tobacco, is generally accepted to be
responsible for most neuropharmacological effects due to tobacco use. Little is
known about the action of cotinine, the major metabolite from nicotine, at
neuronal structures. To evaluate the mode of action of cotinine at neuronal
receptors, its effect on the surface compound potential of the sympathetic
superior cervical ganglion (SCG) of the mouse was studied. The modulation of
nicotine induced surface potentials by cotinine was tested. It was found that 2
min applications of cotinine (0.1-30 mmol/l) induced concentration dependent
depolarizations at the SCG (EC(50)=1.7 mmol/l) which were followed by
hyperpolarizations and weak afterdepolarizations. The intrinsic activity of
cotinine compares to that induced by much lower concentrations of nicotine
(EC(50)=21 micromol/l). These cotinine effects may be mediated at least in part
by nicotine impurities which were found by capillary electrophoresis to be 0.1
and 0.8% in different batches of cotinine. Continuous application of 300
micromol/l cotinine shifted the concentration-response curve of nicotine to the
right and reduced (IC(50)=302 micromol/l) the effects of submaximal nicotine
concentrations (30 micromol/l). This effect could not be mimicked by continuous
application of a nicotine concentration (0.3 micromol/l) equivalent to the lower
impurity in cotinine. Therefore, the antagonistic action of cotinine at
peripheral neuronal nicotinic receptors is at least in part independent of
nicotine impurity. The observed antagonistic effect of cotinine at nicotinic
receptors likely contributes to the neuropharmacological effects of smoking.
PMID- 10781877
TI - Environmental inhibition of 11beta-hydroxysteroid dehydrogenase.
AB - Gossypol, a polyphenolic compound from cotton seed, caused hypokalemia in some
men receiving it in a trial of its contraceptive activity. Searching for the
mechanism for its hypokalemic action led to the observation that it inhibited
11beta-hydroxysteroid dehydrogenase. This would enhance mineralocorticoid effect
in the kidney. Many other polyphenols also inhibit this enzyme including those in
grapefruit juice. Ingesting 1-2 l of grapefruit juice inhibited this enzyme in
two men in a clinical experiment. Tea polyphenols inhibit this enzyme and add to
the inhibition caused by gossypol. Men in China have lower serum potassium values
than men elsewhere and this is due to the environment, presumably the diet, in
China. The importance of dietary and other exogenous inhibitors of this enzyme in
electrolyte metabolism remains to be determined.
PMID- 10781878
TI - Human 11beta-hydroxysteroid dehydrogenase 1/carbonyl reductase: recombinant
expression in the yeast Pichia pastoris and Escherichia coli.
AB - Detoxification of aldehydes and ketones generally proceeds via reduction to their
corresponding alcohols, which are then conjugated and eliminated. We focused our
interest on 11beta-hydroxysteroid-dehydrogenase type 1 (11beta-HSD 1), a
pluripotent enzyme which physiologically performs the interconversion of active
and inactive glucocorticoid hormones, and which also participates in xenobiotic
carbonyl compound detoxification. 11beta-HSD 1 belongs to the protein superfamily
of the short-chain dehydrogenases/reductases (SDR), and has been structurally and
functionally characterized. 11beta-HSD 1 is a glycosylated membrane protein which
is very difficult to purify in an active state. In addition, expression levels in
humans differ in a wide range. In order to facilitate biochemical and molecular
studies on the significance of human 11beta-HSD 1 in detoxification processes, we
have successfully performed the overexpression of recombinant human 11beta-HSD 1
in the yeast Pichia pastoris and in Escherichia coli. Recombinant 11beta-HSD 1
from E. coli was purified to homogeneity and used to generate a polyclonal
antibody. The enzyme had no enzymatic activity, possibly due to the lack of
glycosylation and/or incorrect folding in E. coli. In contrast, 11beta-HSD 1
overexpressed in P. pastoris was enzymatically active towards its physiological
glucocorticoid substrates as well as towards xenobiotic carbonyl compounds. In
western blot experiments the antibody crossreacted with both recombinant 11beta
HSD 1 forms and with the native enzyme from mouse and human liver. In conclusion,
recombinant 11beta-HSD 1 from P. pastoris serves as a valuable tool for future
studies on carbonyl compound detoxification.
PMID- 10781879
TI - Toxicologic evidence of developmental neurotoxicity of environmental chemicals.
AB - Developmental neurotoxicity constitutes effects occurring in the offspring
primarily as a result of exposure of the mother during pregnancy and lactation.
To exert their effect, these chemicals or their metabolites must pass the
placenta and/or the blood-brain barrier. In experimental animals, exposure to
neurotoxic chemicals during critical periods of brain development has induced
permanent functional disturbances in the CNS. Although available data suggest
that proper animal models exist, only few chemicals have been tested.
Neurotoxicity testing is not required by national authorities for classification
of chemicals. Epidemiological evidence is very limited, but severe irreversible
effects have been observed in humans following in utero exposures to a few known
developmental neurotoxicants. The large number of chemicals with a potential for
developmental neurotoxicity in humans stresses the importance of generating basic
kinetic data on these chemicals based on relevant experimental models. First of
all, data are needed on their ability to pass the placenta and the developing
blood-brain barrier, to accumulate, and to be metabolized in the placenta and/or
the fetus. These kinetic data will be essential in establishing a scientifically
based hazard evaluation and risk assessment.
PMID- 10781880
TI - Genetic polymorphism of CYP2A6 in the German population.
AB - Genetic polymorphism of drug metabolizing enzymes (DME) can lead to severe
toxicity or therapeutic failure of pharmacotherapy. Additionally, genetically
determined differences in the activity of the metabolic enzymes can increase an
individual's susceptibility to certain types of chemically induced cancers and
possibly other diseases. Cytochrome P450 is one of the most important metabolic
systems of the organism involved in the oxidation of different xenobiotics. This
contribution summarizes and updates the information concerning the genetic
polymorphism of the CYP2A6 isoform of the cytochrome P450. A special emphasis is
put upon the genotyping techniques of CYP2A6 with a comparative analysis of their
predictable sensitivity and specificity given on the example of the German
population.
PMID- 10781881
TI - CYP2A6: a human coumarin 7-hydroxylase.
AB - Coumarin 7-hydroxylation is catalysed by a high-affinity CYP2A6 enzyme in human
liver microsomes. CYP2A6 is the only enzyme catalysing this reaction and
consequently the formation of 7-hydroxycoumarin can be used as 'an in vitro and
in vivo probe' for CYP2A6. CYP2A6 is a major contributor to the oxidative
metabolism of nicotine and cotinine, and it also contributes, to a larger or
smaller extent, to the metabolism of a few pharmaceuticals (e.g. fadrozole),
nitrosamines, other carcinogens (e.g. aflatoxin B1) and a number of coumarin-type
alkaloids. CYP2A6 may be inducible by antiepileptic drugs and it is decreased in
alcohol-induced severe liver cirrhosis. Several mutated or deleted CYP2A6 alleles
have been characterized. Although CYP2A6 represent up to 15% of human microsomes
P450 proteins, it is still one of the less well characterised cytochrome P450
enzymes.
PMID- 10781883
TI - Confounding variables in the environmental toxicology of arsenic.
AB - Arsenic is one of the most important global environmental toxicants. For example,
in regions of West Bengal and Inner Mongolia, more than 100000 persons are
chronically exposed to well water often strongly contaminated with As.
Unfortunately, a toxicologically safe risk assessment and standard setting,
especially for long-term and low-dose exposures to arsenic, is not possible. One
reason is that the key mechanism of arsenic's tumorigenicity still is not
elucidated. Experimental data indicate that either DNA repair inhibition or DNA
methylation status alteration may be causal explanations. Moreover, when
comparing epidemiological data, it cannot be ruled out that the susceptibility to
arsenic's carcinogenicity may be different between Mexican and Taiwanese people.
Some other studies indicate that some Andean populations do not develop skin
cancer after long-term exposure to As. It is not known yet how this resistance
could be mediated. Finally, the situation is even more complicated when taking
into consideration that there are several compounds suspected to modulate the
chronic environmental toxicity of arsenic, variables that may either enhance or
suppress the in vivo genotoxicity and carcinogenicity of the metalloid. Among
them are nutritional factors like selenium and zinc as well as drinking water co
contaminants like antimony. Further, yet unidentified factors influencing the
body burden and/or the excretion of arsenic are possibly prevailing: preliminary
data from own human biomonitoring studies showed a peaking of As in urine samples
of non-exposed people which was not caused by elevated exposure to As through
seafood consumption. The relevance of these putative confounding variables cannot
be finally evaluated yet. Further experimental as well as epidemiological studies
are needed to answer these questions. This would help to conduct a
toxicologically improved risk assessment, especially for low-dose and long-term
exposures to arsenic.
PMID- 10781882
TI - Laryngeal mucosa of head and neck cancer patients shows increased DNA damage as
detected by single cell microgel electrophoresis.
AB - Major risk factors for cancer of the oral cavity, pharynx and larynx are smoking
and excess alcohol consumption. Since long-term survival rates of head and neck
cancer patients have not substantially been improved, new preventive strategies
including the use of cancer chemopreventive agents have to be developed. With the
aim of developing biomarkers which can verify the efficacy of chemopreventive
interventions, a standardised alkaline microgel electrophoresis (MGE) assay was
applied as a sensitive and rapid tool to detect DNA damage on a single cell
level. Macroscopically normal laryngeal mucosa biopsies obtained by surgery from
head and neck cancer patients (n=29) and from hospital controls (n=22) were
analysed by MGE in a pilot study. As compared to controls, cells from head and
neck cancer patients showed a significantly elevated DNA damage without any
further genotoxic treatment (P<0.01). We conclude that this increased background
DNA damage in laryngeal epithelia could result from genetic alterations caused by
smoking and alcohol leading, in accord with the field cancerisation hypothesis,
to a gradual decrease of genomic stability and malignancy. MGE should now be
explored as a rapid screening method in larger clinical studies: (i) to identify
high-risk subjects carrying cells with decreased genomic stability and (ii) to
verify the efficacy of chemopreventive regimens to prevent or slow down the
development of head and neck cancer in high-risk persons.
PMID- 10781884
TI - Lack of quinone reductase activity suggests that amyloid-beta peptide/ERAB
induced lipid peroxidation is not directly related to production of reactive
oxygen species by redoxcycling.
AB - Mitochondrial type II hydroxyacyl-CoA dehydrogenase (ERAB) has recently been
shown to mediate amyloid-beta peptide (Abeta) induced apoptosis and
neurodegeneration. The precise mechanism of cell death induction is unknown,
however, Abeta inhibits ERAB activities and as a result of ERAB-Abeta
interactions, enhanced formation of lipid peroxidation products occur. The
possibility that ERAB mediates quinone reduction is therefore investigated, thus
giving the potential of redoxcycling and production of reactive oxygen species,
leading to lipid peroxidation. Recombinant human ERAB was produced in a bacterial
expression system and enzymological properties were evaluated. Using several
orthoquinones as substrates, no ERAB mediated quinone reductase activity was
found either in the presence or absence of Abeta, suggesting that the observed in
vivo lipid peroxidation is a result of other mechanisms than redoxcycling by
quinones.
PMID- 10781885
TI - Dose and time as variables of toxicity.
AB - Recognizing that if there is no exposure, there is no toxicity leads us to the
conclusion that if there is exposure, toxicity can ensue when exposure exceeds a
certain dose and/or time and that it will be dependent on toxicokinetics and
toxicodynamics. Analysis of the fundamental description of toxicity
(dT/dE=dT/dDxdD/dKxdK/dE, where T stands for toxicity, D for toxicodynamics, K
for toxicokinetics and E for exposure) yields the recognition of three
independent time scales, the first being an intrinsic property of a given
compound (what does the chemical do to the organism), which is the dynamic time
scale. The second time scale is an intrinsic property of a the organism (what
does the organism do to the chemical), which represents the kinetic time scale.
The frequency of exposure denotes the third time scale, which is independent of
the dynamic and kinetic time scales. Frequency of exposure depends on the
experimental design or on nature, but not on the organism or substance. A liminal
condition occurs when the frequency becomes so high that it is indistinguishable
from continuous exposure. Continuous exposure forces the two other time scales to
become synchronized thereby reducing complexity to three variables: dose, effect
and one time scale. Keeping one of those variables constant allows for the study
of the other two variables reproducibly under isoeffective or isodosic or
isotemporal conditions. However, any departure from continuous exposure will
introduce the full complexity of four independent variables (dose and kinetic,
dynamic and frequency time scales) impacting on the effect (dependent variable)
at the same time. The examples discussed in this paper demonstrate how nature in
the form of long half-lives provides liminal conditions when either kinetic or
dynamic half lives force synchronization of all three time scales. However, for
compounds having very short dynamic or kinetic half-lives, only continuous
exposure will provide a synchronized time scale. A decision tree-type approach is
being used to illustrate how to reduce the enormous complexity generated by five
variables (dose, effect and up to three time scales) in toxicology to manageable
proportions by identifying and modeling the rate-determining (-limiting) step(s)
in the manifestation of toxicity.
PMID- 10781887
TI - Modulation of daunorubicin toxicity by liposomal encapsulation and use of
specific inhibitors in vitro.
AB - Anthracyclines serve as a valuable tool in chemotherapy, but their usefulness is
often limited by the occurrence of resistance mechanisms in tumor cells.
Resistance of tumor cells is a multifactorial event, where several mechanisms act
concurrently, including drug efflux and enzymatic drug inactivation. Liposomal
encapsulation of anthracyclines has been discussed as a successful regimen to
overcome drug resistance. Our investigations were carried out on a daunorubicin
(DRC) sensitive breast cancer cell line and two DRC resistant sublines generated
thereof. In all three cell lines, the extent of DRC detoxification via carbonyl
reduction to daunorubicinol (DRCOL) was determined. In addition, rutin, the most
effective inhibitor of carbonyl reducing enzymes, was tested to affect DRCOL
formation. DRC IC(50) values were determined in relation to several combinations
of DRC administration, (a) liposomal encapsulated DRC, (b) addition of verapamil
(inhibitor of drug efflux), (c) addition of rutin (inhibitor of DRC carbonyl
reduction). We could show that DRC sensitive and resistant breast cancer cell
lines are able to catalyze DRC detoxification via carbonyl reduction to DRCOL.
Rutin was shown to inhibit this reaction, but could not serve as an enhancer of
DRC toxicity in MTT tests. Verapamil was effective only in resistant cells due to
the overexpression of P-glycoprotein 170. Liposomal encapsulation of DRC did not
show the expected increase in DRC toxicity in the present tumor cell model.
PMID- 10781886
TI - Tissue distribution of 2-(2-nitro-4-trifluoromethylbenzoyl)-cyclohexane-1,3-dione
(NTBC) and its effect on enzymes involved in tyrosine catabolism in the mouse.
AB - Administration of a single oral dose of 2-(2-nitro-4-trifluoromethyl-benzoyl)
cyclohexane-1,3-dione (NTBC) to mice increases the concentration of tyrosine in
the plasma and aqueous humour. The tyrosinaemia is both time and dose-dependent
with a single dose of 30 micromol NTBC/kg (10 mg/kg) producing maximal
concentrations of tyrosine in plasma of about 1200 nmol/ml and in aqueous humour
of about 2200 nmol/ml at 16 h after dosing. Analysis of the key hepatic enzymes
involved in tyrosine catabolism, following a single dose of 30 micromol NTBC/kg,
showed that 4-hydroxyphenylpyruvate dioxygenase (HPPD) was markedly inhibited
soon after dosing and that the activity recovered very slowly. In response to the
tyrosinaemia, the activity of hepatic tyrosine aminotransferase (TAT) was induced
about two-fold, while the activity of hepatic homogentisic acid oxidase (HGO) was
reduced at 4 and 5 days after dosing. Daily oral administration of NTBC at doses
up to 480 micromol NTBC/kg (160mg/kg/day) to mice produced a maximal tyrosinaemia
of about 600-700nmol/ml plasma, showing some adaptation relative to a single
dose. Unlike the rat, no treatment-related corneal lesions of the eye were seen
at any dose levels up to 6 weeks. Administration of a single oral dose of [14C]
NTBC at 30 micromol/kg led to selective retention of radiolabel in the liver and
to a lesser extent the kidneys. Our studies show that NTBC is a potent inhibitor
of mouse liver HPPD, which following repeat exposure produces a marked and
persistent tyrosinaemia, which does not result in ocular toxicity.
PMID- 10781888
TI - Structural characteristics of human P450s involved in drug metabolism: QSARs and
lipophilicity profiles.
AB - The factors with human P450 substrate selectivity are reviewed, together with
extensive tabulation of quantitative relationships between structure and activity
for many species of P450 substrates, inducers and inhibitors. In addition, the
physicochemical characteristics (logP and pK(a) values) of heptic microsomal P450
substrates are collated, such that comparisons can be made on the grounds of
compound lipophilicities.
PMID- 10781889
TI - Reduction of gastrointestinal toxicity of NSAIDs via molecular modifications
leading to antioxidant anti-inflammatory drugs.
AB - Reactive oxygen species and free radical reactions are related to several
pathologic conditions including inflammation and gastric ulceration. The latter
is the major undesired side-effect of almost all NSAIDs. Since this effect of
NSAIDs is greatly influenced not only by the type of cyclooxygenase which is
inhibited but also by the acidic nature of the molecule, we considered it
interesting to modify their structure in such a way that it would lead to an
antioxidant, neutral molecule or a molecule with greatly reduced acidic
character. Thus, we synthesized amide derivatives of four well-known NSAIDs, i.e.
diclofenac acid, tolfenamic acid, ibuprofen and indomethacin, with cysteamine, a
well-known antioxidant. The synthesized derivatives, with demonstrated good anti
inflammatory and antioxidant activities, showed very significant reduction of
ulcerogenicity in the investigation of gastrointestinal (GI) toxicity. As indices
of ulcerogenic toxicity in rats, we used the mortality (%), the incidence of GI
ulcers (%), body weight reduction (g/100 g BW) and the incidence of melena. All
amide derivatives of the NSAIDs with cysteamine were almost non-toxic in the GI
tract, under our experimental conditions, in contrast to their parent NSAIDs.
These results are attributed to the acquired antioxidant activity as well as to
the reduction of acidic character compared with the parent compounds. Therefore,
it can be concluded that the combination of these two properties, anti
inflammatory and antioxidant activity, with a simultaneous drastic reduction of
acidic character, may lead to the development of novel, useful anti-inflammatory
and cytoprotective pharmacomolecules, with potentially important therapeutic
applications.
PMID- 10781890
TI - Enhanced expression of CYP1B1 in Escherichia coli.
AB - Conditions for the optimal expression of the human CYP1B1 hemoprotein in
Escherichia coli have been investigated. CYP1B1 cDNA was prepared from a retinal
cDNA template and used to generate cDNA fragments with modified 5'-sequences
reported to allow enhanced expression in E. coli DH5alpha. Plasmids were
constructed, using the pCWori+ expression vector and were used to examine
necessity for thiamine, delta-aminolevulinic acid (ALA), and IPTG. The optimal
shaking speed in an orbital incubator was 150 rpm at 30 degrees C. Higher speeds
resulted in increased cell death and lower speeds resulted in lower expression of
cytochrome P450. IPTG was necessary for this expression system, which makes use
of the lac repressor, but levels above 0.5 mM were without additional benefit. We
were able to show thiamine to be unnecessary in this expression system, although
included by others expressing CYP1B1. ALA has been reported to enhance expression
of several different forms of cytochrome P450. We examined the dependence of
CYP1B1 expression on ALA. The expression proved to be highly dependent upon this
heme precursor, with levels of CYP1B1 increasing approximately 20-fold, to 920
nmol/l in the presence of up to 2.5 mM ALA. The question of whether heme
synthesis and apoprotein synthesis were coupled was then investigated. It could
be shown that although heme synthesis was not limiting (CYP101 holoenzyme
expression in the absence of ALA was four times higher than the ALA-supported
CYP1B1 holoenzyme expression), it was necessary for optimal expression of CYP1B1.
CYP1B1 protein synthesis appears to be coupled to heme precursor availability, as
seen by SDS-PAGE, because in the absence of heme precursor apocytochrome P450 1B1
does not accumulate.
PMID- 10781891
TI - Reversal of HER-2 over-expression renders human ovarian cancer cells highly
resistant to taxol.
AB - Currently, the treatment options for advanced ovarian cancer are limited. Thus,
the majority of the patients are treated with drugs with considerable side
effects but in many cases without clinical benefit. The relationship between
activation of an oncogene like the HER-2 receptor and drug sensitivity, is of
considerable interest as this molecular marker may allow to better predict
response to chemotherapy. The aim of this study was to evaluate whether over
expression of the HER-2 receptor would modulate drug responsiveness to
doxorubicin, cisplatin and taxol in ovarian cancer cells. An anti-HER-2-targeted
ribozyme approach was used to abrogate HER-2 expression in human SK-OV-3 ovarian
cancer cells. SK-OV-3 cells expressing very low residual levels of HER-2 protein,
were then assessed for their sensitivity to doxorubicin, cisplatin and taxol and
compared to control cells. HER-2 expression had no effect on the cytotoxicity of
doxorubicin (IC50=10 nM) or cisplatin (IC50=5 microM) in proliferation assays. In
contrast, the sensitivity to taxol was increased approximately 70-fold in SK-OV-3
ovarian cancer cells expressing high levels of HER-2 (IC50=10(-5) nM) compared to
HER-2 depleted cells (IC50=7x10(-4) nM). If these findings can be confirmed in
patients, it could be possible that HER-2 expression may serve as a marker for
response to taxol treatment in ovarian cancer patients.
PMID- 10781892
TI - Monitoring of cytochrome P-450 1A activity by determination of the urinary
pattern of caffeine metabolites in Wistar and hyperbilirubinemic Gunn rats.
AB - Various studies suggest that induction of cytochrome P-450 1A (CYP1A) might be a
valuable therapeutic modality for reducing the hyperbilirubinemia of infants with
Crigler-Najjar syndrome type I (CNS-I), a severe form of congenital jaundice. To
evaluate inducers of CYP1A as possible tools in the treatment of
hyperbilirubinemia, a novel assay was established, based on the analysis of the
urinary pattern of caffeine metabolites in rats. Wistar rats received [1-Me
(14)C]-caffeine (10 mg/kg i.p.), before and 48h after administration of the
potent CYP1A inducer 5,6-benzoflavone (BNF) (80 mg/kg, i.p.). A substantial
increase in the fractions of the terminal caffeine metabolites 1-methyluric acid
(1-U), 1-methylxanthine (1-X), and a concomitant decrease in the caffeine
demethylation product 1,7-dimethylxanthine (1,7-X) was observed after application
of BNF. The ratio of the caffeine metabolites (1-U+1-X)/1,7-X may serve as an
index of CYP1A activity in rats in vivo. Hyperbilirubinemic, homozygous (jj) Gunn
rats are an accepted model for human CNS-I. In male jj Gunn rats treated with BNF
or with indole-3-carbinol (I3C, 80 mg/kg, oral gavage), the inducing effect of
BNF and 13C on CYP1A activity was confirmed by the urinary pattern of caffeine
metabolites, and was parallelled by a decrease in plasma bilirubin levels. These
data demonstrate the usefulness of the established caffeine assay for the
evaluation of inducers of CYP1A as tools for reducing hyperbilirubinemia and
further confirm the potential value of I3C in the treatment of CNS-I.
PMID- 10781893
TI - Meeting report on an NHLBI workshop on ex vivo expansion of stem cells, July 29,
1999, Washington, D.C. National Heart Lung and Blood Institute.
PMID- 10781894
TI - The gp130-stimulating designer cytokine hyper-IL-6 promotes the expansion of
human hematopoietic progenitor cells capable to differentiate into functional
dendritic cells.
AB - OBJECTIVE: Hyper-IL-6, a fusion protein of interleukin-6 and its specific
receptor, together with stem cell factor leads to the proliferation of primitive
hematopoietic progenitor cells. Based on these findings, the current study
examined whether hyper-IL-6 promotes the growth of precursor cells that can be
further differentiated into dendritic cells in the presence of additional
cytokines. METHODS: Dendritic cell cultures were generated from CD34(+)
hematopoietic progenitor cells derived either from bone marrow or from peripheral
blood. CD34(+) cells were cultured in the presence of cytokines for 2 weeks and
then used for phenotyping and T-cell stimulation assays. RESULTS: Hyper-IL-6 in
the presence of stem cell factor induced a 60- to 80-fold expansion of CD34(+)
progenitor cells following 2 weeks of culture in serum-free medium. The addition
of granulocyte-macrophage colony-stimulating factor to hyper-IL-6 and stem cell
factor was essential for the differentiation of expanded progenitor cells into
antigen presenting cells capable of inducing a primary T-cell response to soluble
protein, which is a typical feature of dendritic cells. Phenotypic analyses
confirmed the expansion of immature dendritic cells, which could be further
differentiated into mature CD83(+) dendritic cells under the influence of
interleukin-4, interleukin-1beta, tumor necrosis factor-alpha, and prostaglandin
E(2). The capacity of expanded dendritic cells to stimulate protein-specific
CD4(+) T cells was used to stimulate a primary T-helper cell response to the
recombinant protein of the hepatitis-B core antigen in healthy donors.
CONCLUSION: The expansion and differentiation of functional dendritic cells from
CD34(+) progenitor cells under serum-free culture conditions allow for the
possibility to develop more effective ways to immunize against viral infections
and tumor diseases.
PMID- 10781896
TI - Adenoviral-mediated gene transfer into ex vivo expanded human bone marrow
mesenchymal progenitor cells.
AB - OBJECTIVE: Based on their differentiation properties and facilely of ex vivo
expansion, human bone marrow mesenchymal progenitor cells (MPC), are considered
as attractive targets to deliver foreign genes to the bone marrow or other
mesenchymal tissues. In this study we investigated the feasibility of transduce
MPC with adenoviral vectors (Adv). METHODS: MPC were expanded ex vivo and
transduced with replication-defective Adv-containing reporter genes (lacZ or GFP)
under the control of CMV promoter. Transfection efficiency was assessed by
microscopical scoring or by flow cytometry. Expression and involvement of Adv
attachment (CAR) and Adv-internalization (integrins alphav) receptors were
evaluated by flow cytometric studies. RESULTS: Transgene expression analysis
showed that only 19%+/-3% of cells expressed the transgenes at high levels. MPC
express the attachment and internalization receptors required for Adv infection.
While integrins alphavbeta3 and alphavbeta5 are expressed by all MPC, CAR is
solely expressed by a fraction of low size cells. Antibodies against CAR and
alphavbeta5, but not against alphavbeta3, blocked Adv-mediated gene transfer into
MPC, showing that CAR and alphavbeta5 are required for infection. Because
alphavbeta5, as compared with CAR, is overexpressed in MPC, the results suggest
that the efficiency of Adv-mediated gene transfer into MPC depends on the level
of CAR expression. CONCLUSION: These findings demonstrate that Adv may be useful
to engineer a subpopulation of ex vivo expanded human mesenchymal progenitors,
with a high level of transgene expression.
PMID- 10781895
TI - Low level of gene transfer to and engraftment of murine bone marrow cells from
long-term bone marrow cultures.
AB - OBJECTIVE: We wanted to determine whether the long-term bone marrow culture
(LTBMC) transduction system would lead to efficient gene transfer and engraftment
of murine repopulating hematopoietic stem cells (HSC), particularly in nonablated
recipients. MATERIALS AND METHODS: Congenic mouse strains expressing Ly 5.1 or Ly
5.2 and the GP+E86 cell line producing the MGirL22Y vector carrying the gene for
enhanced GFP were used. Murine LTBMCs were established and demi-depopulated on
days 7 and 14 with addition of vector supernatant on days 8 and 15. RESULTS: Cell
recovery on day 21 was 21.3%+/-3.8% of input cells and CFU-C recovery was 9.7+/
3.4% as compared with CFU-C of input cells. In vitro transduction efficiency
determined by CFU-C expressing GFP was 22.2%+/-1.6%. In irradiated (950 cGy) mice
transplanted with 2x10(6) LTBMC cells, 94% of nucleated cells in the blood at
week 16 were of donor origin. However, GFP was only detected at low level in a
few animals at week 4 and not later. Analysis of bone marrow from these mice at
week 20 did not show any GFP expression and semiquantitative PCR revealed a
transgene level of <1%. When 3.5-20.8x10(6) LTBMC cells (corresponding to 20
100x10(6) fresh cells) were transplanted to nonablated recipients, no engraftment
or GFP expression were detected. Competitive repopulation experiments showed that
the long-term repopulation ability (LTRA) of the LTMC cells was only 7% of fresh
cells. CONCLUSION: These results indicate that LTBMC transduction of murine cells
leads to low-level transduction of progenitors, no gene transfer to repopulating
stem cells, and reduction in LTRA in ablated and nonablated recipients.
PMID- 10781897
TI - Augmentation of human leukemic cell invasion by activation of a small GTP-binding
protein Rho.
AB - OBJECTIVE: The functions of a small GTP-binding protein, Rho, in human leukemic
cell invasion was investigated in vivo and in vitro. MATERIALS AND METHODS: Human
leukemic KM3 and Reh cells (derived from B-cell-type common acute lymphoid
leukemias) were inoculated into severe combined immundeficiency (SCID) mice.
Alteration of invasion in SCID mice inoculated with KM3 cells that were
introduced with the expression vector for Rho Val14 (Rho V14), an activated
mutant form of Rho, was observed. RESULTS: SCID mice inoculated with KM3 and Reh
cells developed paraplegia 21 days after inoculation. All died by day 26-27. The
leukemic cells were localized to bone marrow and around the spinal cord, with no
infiltration into peripheral blood, spleen, liver, thymus, or lymph nodes. SCID
mice inoculated with Rho V14-transfected KM3 cells showed a 5-day reduction in
the time to paraplegia and death compared with SCID mice inoculated with
hygromycin-resistance gene-transfected KM3 (hyg(r)) cells. In addition, the mice
inoculated with Rho V14 cells showed leukemic cell infiltration, not only into
bone marrow and around the spinal cord but also into peripheral blood, liver, and
spleen. There were no in vitro or in vivo differences in growth rates of Rho V14
and hyg(r) cells. However, the Rho V14 cells showed markedly increased cell
adhesion compared to the hyg(r) cells. CONCLUSION: Results suggest that Rho
activation accelerates human leukemic cell invasion via augmentation of cell
adhesion.
PMID- 10781898
TI - Regulation of megakaryocytopoiesis in an in vitro stroma model: preferential
adhesion of megakaryocytic progenitors and subsequent inhibition of maturation.
AB - OBJECTIVE: Studies of megakaryocytic progenitor cell interactions have focused on
single receptor-ligand interactions using isolated components of the
extracellular matrix. To approach a physiologic condition, we studied
megakaryocytic development of human progenitor cells cultured on two stromal cell
lines and on human bone marrow stroma. MATERIALS AND METHODS: Human CD34(+) cells
were cocultured with stromal layers in the presence of thrombopoietin.
Megakaryocytes were quantified by monoclonal antibodies against glycoprotein (GP)
IIb/IIIa (CD41) and GPIX (CD42a). Megakaryocytic clonogenic capacity (burst
forming unit-megakaryocyte and colony-forming unit-megakaryocyte) was determined
using fibrin clot assays. RESULTS: After 6 days, a higher percentage of
megakaryocytes and more megakaryocytic colonies were recovered from the adherent
cell fraction compared to the nonadherent cell fraction. In contrast,
significantly more granulocytic and erythroid colonies were recovered from the
nonadherent cell fraction. Repeated replating of nonadherent cells onto fresh
stroma showed a decline in megakaryocytic recovery of the remaining adherent
cells, pointing toward selective adhesion of megakaryocytic progenitors. This was
supported further by the finding that burst-forming unit and colony-forming unit
megakaryocytes were preferentially recovered from the adherent cell fraction at
24 hours. No effect of blocking the beta(1) integrins VLA-4 and VLA-5 on human
progenitor cells was observed. A higher expression of CD42a antigen and a higher
percentage of morphologically recognizable polyploid megakaryocytes were found
when cells were grown in noncontact cultures compared to when grown adhered to
stroma. CONCLUSION: In contrast to granulocytic and erythroid progenitors, both
very early and more mature megakaryocytic progenitors are preferentially located
in the adherent fraction in an in vitro stromal model, leading to inhibition of
maturation of megakaryocytes. This suggests that the presence of stroma
components in ex vivo expansion cultures, aimed at preservation and expansion of
megakaryocytic progenitors, might be a prerequisite.
PMID- 10781899
TI - Characterization of prostaglandin endoperoxide H synthase-1 enzyme expression
during differentiation of the megakaryocytic cell line MEG-01.
AB - OBJECTIVE: Because the prostaglandin endoperoxide H synthase-1 (PGHS-1)-dependent
formation of thromboxane A(2) is an important modulator of platelet function,
this pathway represents a pharmacologic target for the inhibition of platelet
function by aspirin. The objective of our research was to study how PGHS-1
expression is regulated in platelets. MATERIALS AND METHODS: Because platelets
are anucleated, their protein content is a consequence of gene expression in
precursor cells known as megakaryocytes. We used the immortalized human
megakaryoblastic cell line MEG-01 as a model to study the expression of PGHS-1,
because MEG-01 cells can be induced to differentiate into platelet-like
structures by adding nanomolar concentrations of 12-0-tetradecanoylphorbol-13
acetate (TPA). We determined the expression profiles of PGHS-1 protein and mRNA
in the cells comprising the three different populations of MEG-01 cultures:
nucleated floating, nucleated attached, and platelet-like structures. RESULTS: We
determined that PGHS-1 protein levels were higher in the nucleated adherent
population than in the nucleated floating population. PGHS-1 protein levels were
greatest in the anucleated platelet-like population. In contrast, we found that
PGHS-1 mRNA levels were highest in the cells that comprised the nucleated
adherent population. Addition of TPA induced the expression of PGHS-1 protein and
mRNA in all three populations but did not change the relationship of the amount
of PGHS-1 protein or mRNA expressed in a given population relative to the other
two fractions. We measured the expression of PGHS-1 protein on a cell-by-cell
basis in the nucleated MEG-01 populations. We found that the percentage of MEG-01
cells expressing PGHS-1 protein in the adherent population was greater than in
the floating population. We measured a time-dependent increase in the percentage
of cells that expressed PGHS-1 over a period of 8 days after singular addition of
TPA (1.6x10(-8)M). Importantly, we observed that TPA treatment stimulated
floating MEG-01 to adhere to the surface of the tissue culture vessel and that,
after such treatment, only floating MEG-01 cells suffered a compromised
viability. We found that a high percentage of control cells expressed
glycoprotein IIb/IIIa and that TPA treatment did not significantly alter this
percentage. We did not detect glycoprotein Ib in control cells but did measure a
slight increase in the percentage of MEG-01 cells that expressed this antigen in
the TPA-treated population. CONCLUSION: We established a correlation between the
level of PGHS-1 expression and the overall level of differentiation of MEG-01
cells. PGHS-1 protein expression, which increases consistently over the full
course of differentiation, now may be used as an additional and perhaps better
index by which to survey megakaryocytes.
PMID- 10781900
TI - Molecular analysis of the hematopoiesis supporting osteoblastic cell line U2-OS.
AB - OBJECTIVE: Osteoblasts play an important role in regulating hematopoiesis in the
bone marrow. Here we show that U2-OS, a widely used osteoblastic cell line
derived from an osteosarcoma, has the capacity to support proliferation of human
hematopoietic progenitor cells in vitro. In this study, U2-OS cells are
characterized at the molecular level to unravel the molecular mechanisms
underlying the support of hematopoiesis. MATERIALS AND METHODS: U2-OS was
analyzed in great detail using RT-PCR and flow cytometry. In addition, a cDNA
library was constructed and randomly sequenced to obtain insight in the
repertoire of expressed molecules. RESULTS: A broad panel of growth factors and
cytokines is expressed by U2-OS. TGF-beta, GM-CSF, c-kit ligand, and IL-7 are
produced constitutively and IL-1beta, IL-6, IL-8, TNF-alpha, IFN-gamma, and MIP1
alpha are upregulated upon stimulation. In addition to those, mRNAs of the CC
chemokine LARC and leukemia inhibitory factor were identified. U2-OS cells
express high levels of beta1-integrins at the cell surface: VLA-2, VLA-3, VLA-4,
VLA-5, VLA-6, and the integrin alphavbeta3. Besides integrins, ALCAM and NCAM are
detected on the cell surface of U2-OS. Interestingly, we show that CD34(+)
progenitor cells expressing ALCAM are highly proliferative when compared with
CD34(+) ALCAM(low) cells, hinting at a role for ALCAM in anchoring progenitor
cells to the bone marrow stroma. Interestingly, random sequencing of an U2-OS
cDNA library yielded almost 10% of novel cDNAs with a potential role in
hematopoiesis. The involvement of these novel molecules in hematopoiesis is an
interesting target for future investigations. CONCLUSIONS: We conclude that U2-OS
supports outgrowth of hematopoietic progenitor cells and accordingly expresses
adhesion molecules and growth factors and a number of novel, as yet
uncharacterized potentially interesting genes.
PMID- 10781901
TI - Overexpression of the homeobox gene DLX-7 inhibits apoptosis by induced
expression of intercellular adhesion molecule-1.
AB - OBJECTIVE: DLX genes constitute a subfamily of divergent homeobox genes. We have
previously reported that inhibition of DLX-7 expression by an antisense
oligonucleotide caused apoptosis in the K562 erythroleukemia cell line, which
highly expresses DLX-7. In this study, we have constructed an expression vector
encoding human DLX-7, and examined the effects of overexpression of DLX-7 in the
IL-3-dependent lymphoid precursor cell line Ba/F3. METHODS: DLX-7 expression
vector was electroporated into Ba/F3 cells, and generate a DLX-7 expressing Ba/F3
cells. Northern blot analysis was performed to determine DLX-7 gene expression.
WST-1 assay was used to cell proliferation assay. To detect apoptosis, we
performed TUNEL assay. Expression of cell surface adhesion molecules was examined
by FACS analysis. RESULTS: Growth properties of DLX-7-transfected Ba/F3 cells in
the presence of IL-3, did not differ from those of control Ba/F3 cells. However,
in the absence of IL-3, DLX-7-transfected cells abrogated growth dependence on
cytokines due to inhibition of apoptosis. Because adhesion properties of DLX-7
transfected cells increase, we examined expression of adhesion molecules in these
cells. Expression of intercellular adhesion molecule (ICAM)-1 and ICAM-2 were
markedly upregulated in DLX-7-transfected cells. Both anti-ICAM-1 antibody and
anti-LFA-1 antibody blocked the aggregation of DLX-7-transfected cells. Moreover,
in the absence of IL-3, cytokine-independent cell growth was blocked by anti-ICAM
1 antibody. CONCLUSION: These results indicate that DLX-7 overexpression blocks
apoptosis and that ICAM-1 expression induced by DLX-7 contributes to this
antiapoptotic effect.
PMID- 10781902
TI - Genetic regulation of primitive hematopoietic stem cell senescence.
AB - OBJECTIVE: To define effects of strain on PHSC (primitive hematopoietic stem
cells) senescence (decline in function with age) in vivo, and to map a locus that
regulates PHSC senescence. MATERIALS AND METHODS: Long-term function and self
renewal were compared in bone marrow cells (BMC) from old and young mice of three
strains: BALB/cBy (BALB), DBA/2 (D2) and C57BL/6 (B6), using competitive
repopulation and serial transplantation in vivo. BMC from each old or young donor
were mixed with standard doses of congenic, genetically marked BMC and
transplanted into lethally recipients. Percentages of donor-type erythrocytes and
lymphocytes in the recipients determined the functional ability of donor PHSC
relative to the standard, where one repopulating unit (RU) of donor BMC equals
the repopulating ability of 100,000 standard competitor BMC. Using similar
techniques, repopulating abilities of old and young recombinant inbred (RI)
donors of 12 strains derived from BALB and B6 were compared in NK-depleted
BALBxB6 Fl recipients to map a locus that appears to have a major role in PHSC
senescence. RESULTS: PHSC function declined about 2 fold with age in BALB and D2
BMC, and increased more than 2-fold with age in B6 BMC, with all old/young strain
differences significant, p<.01. Ten months after serial transplantation, young
B6, BALB, and D2 PHSC had self-renewed 1.6-, 4.2-, and 3.2-fold better than old,
with BALB and D2 old/young differences p<.01. Young B6 PHSC self-renewed 1.9- and
2.9-fold better than young BALB and D2 PHSC. The PHSC senescence phenotypes
(old/young RU ratios) for 12 CXB RI strains suggested a genetic linkage to
D12Nyul7 on Chromosome 12. CONCLUSION: PHSC senescence is genetically regulated,
and is much delayed in the B6 strain compared to the BALB and D2 strains. A locus
on Chromosome 12 may regulate PHSC senescence.
PMID- 10781903
TI - Docetaxel-induced mobilization of hematopoietic stem cells in a murine model:
kinetics, dose titration, and toxicity.
AB - OBJECTIVE: Docetaxel (DXT) is an anticancer agent that has demonstrated
therapeutic efficacy against solid tumors, particularly breast cancer. Based on
the use of hematopoietic stem cell (HSC) transplantation to restore hematopoietic
reconstitution after myeloablative therapy, this study was performed to determine
if DXT could mobilize HSCs in vivo. MATERIALS AND METHODS: C57Bl/6 mice were
injected intraperitoneally with varying doses of DXT (equivalent to human doses
of 40 to 120 mg/m(2)). Spleens were harvested on days 2, 4, 6, 8, 10, and 12
after DXT administration for recovery of mononuclear cells (MNCs). The number of
HSCs present within the MNCs was determined by clonogenic assay for colony
forming units in culture (CFU-C) and by FACS analysis for CD34(+) cells.
Peripheral blood samples were obtained at the time of spleen harvest to determine
the hematologic profile. Liver and renal function tests were performed to monitor
toxicity. RESULTS: DXT mobilize d HSCs in a dose- and time-dependent manner. When
measured by the CFU-C assay, maximal mobilization of HSC (>10-fold increase in
control; p<0.01) was observed at a dose of 30 mg/kg (equivalent to human dose of
75 mg/m(2)) on day 7. The number of mobilized HSCs peaked on days 6 to 8 at all
doses of DXT tested. There was no evidence of weight loss, liver, or renal
toxicity at any of the DXT doses tested. CONCLUSION: These results indicate that
DXT efficiently mobilizes HSCs in a murine model and provide the rationale for
similar studies in a clinical trial.
PMID- 10781904
TI - Effective ex vivo generation of granulopoietic postprogenitor cells from
mobilized peripheral blood CD34(+) cells.
AB - OBJECTIVE: Neutropenia following high-dose chemotherapy and peripheral blood
progenitor cell (PBPC) transplantation might be abrogated by an additional
transplantation of ex vivo generated granulopoietic postprogenitor cells (GPPC).
Therefore, the ex vivo expansion of CD34(+) PBPC was systematically studied
aiming for optimum GPPC production. MATERIALS AND METHODS: CD34(+) PBPC were
cultured in serum-free medium comparing different (n = 32) combinations of stem
cell factor (S), interleukin 1 (1), interleukin 3 (IL-3) (3), interleukin-6 (6),
erythropoietin (E), granulocyte colony-stimulating factor (G), granulate
macrophage colony-stimulating factor (GM), daniplestim (D, a novel IL-3 receptor
agonist), and Flt3 ligand (FL) under various culture conditions. Ex vivo
generated cells were assessed by flow cytometry, morphology, and progenitor cell
assays. RESULTS: Addition of G +/- GM but not GM alone to cultures stimulated
with S163E effectively induced the generation of GPPC. GPPC production was
maximum after 12 to 14 days. Best expansion rates were observed when cells were
cultured at 1.5x10(4)/mL in 21% O(2). Modifications of culture conditions were
either less or equally effective (i.e., modification of starting cell
concentrations, low oxygen, addition of serum albumin or autologous plasma,
repetitive feeding). Comparison of different cytokine combinations revealed that
the optimum GPPC expansion cocktail consisted of S6GD+FL (day 12: 130-fold
cellular expansion, 32% myeloblasts/promyelocytes, 49.4%
myelocytes/metamyelocytes, 12.4% bands/segmented), which furthermore expanded
CD34(+) cells (3.4-fold) and clonogenic progenitors (13.4-fold). CONCLUSION:
Using the S6DG+FL expansion cocktail, GPPC could be effectively produced ex vivo
starting from positively selected CD34 PBPC, possibly enabling amelioration or
even abrogation of posttransplant neutropenia.
PMID- 10781905
TI - The use of non-pharmacological therapies by pain specialists.
PMID- 10781906
TI - Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of
the art.
AB - In an attempt to explain how and why some individuals with musculoskeletal pain
develop a chronic pain syndrome, Lethem et al. (Lethem J, Slade PD, Troup JDG,
Bentley G. Outline of fear-avoidance model of exaggerated pain perceptions. Behav
Res Ther 1983; 21: 401-408).ntroduced a so-called 'fear-avoidance' model. The
central concept of their model is fear of pain. 'Confrontation' and 'avoidance'
are postulated as the two extreme responses to this fear, of which the former
leads to the reduction of fear over time. The latter, however, leads to the
maintenance or exacerbation of fear, possibly generating a phobic state. In the
last decade, an increasing number of investigations have corroborated and refined
the fear-avoidance model. The aim of this paper is to review the existing
evidence for the mediating role of pain-related fear, and its immediate and long
term consequences in the initiation and maintenance of chronic pain disability.
We first highlight possible precursors of pain-related fear including the role
negative appraisal of internal and external stimuli, negative affectivity and
anxiety sensitivity may play. Subsequently, a number of fear-related processes
will be discussed including escape and avoidance behaviors resulting in poor
behavioral performance, hypervigilance to internal and external illness
information, muscular reactivity, and physical disuse in terms of deconditioning
and guarded movement. We also review the available assessment methods for the
quantification of pain-related fear and avoidance. Finally, we discuss the
implications of the recent findings for the prevention and treatment of chronic
musculoskeletal pain. Although there are still a number of unresolved issues
which merit future research attention, pain-related fear and avoidance appear to
be an essential feature of the development of a chronic problem for a substantial
number of patients with musculoskeletal pain.
PMID- 10781907
TI - A new animal model for assessing mechanisms and management of muscle
hyperalgesia.
AB - Musculoskeletal pain is one of the most frequent symptoms for which medical
assistance is sought. Yet, the majority of our knowledge regarding pain
physiology is based on studies of cutaneous tissue. Comparatively little is known
about activation of visceral, joint and perhaps least of all, musculoskeletal
nociceptors although clinically-treated pain originates principally in these
structures. Studies elucidating the mechanisms of muscle hyperalgesia have been
hampered by the lack of an animal model that permits the evaluation of hypotheses
using behavioral, biochemical, pharmacological, anatomical and molecular
experimental approaches. Here we describe an animal model of muscle hyperalgesia
we recently developed that permits such multidisciplinary investigation. This
model employs the intramuscular injection of carrageenan, a chemical stimulus
which evokes a well recognized model of cutaneous inflammation and is reported to
activate muscle nociceptors. Intramuscular carrageenan evokes a time- and dose
dependent reduction in forelimb grip force that is anatomically specific. The
carrageenan-evoked reduction in grip force is blocked by the mu-opioid agonist
levorphanol in a dose-dependent, stereoselective and naltrexone-reversible
manner. This behavioral dependent measure is also significantly reversed by
agents used clinically to treat muscle pain, indomethacin and dexamethasone, as
well as the non-competitive N-methyl-D-aspartate receptor antagonist MK801.
Finally, evidence that reduction in grip force is in part mediated by small,
unmyelinated afferents is provided by the demonstration that neonatal capsaicin
treatment significantly reduced carrageenan-evoked behavioral hyperalgesia (
approximately 45% reduction) and reduced muscle content of immunoreactive CGRP (
approximately 60% reduction) relative to control levels. Collectively, these
findings provide converging lines of evidence for the validity of this animal
model to investigate mechanisms involved in the development of muscle
hyperalgesia.
PMID- 10781908
TI - The alpha(2A) adrenoceptor and the sympathetic postganglionic neuron contribute
to the development of neuropathic heat hyperalgesia in mice.
AB - We have addressed the role of the sympathetic nervous system in the development
and maintenance of neuropathic pain. Using a new neuropathic mouse model, we
examined the development of hyperalgesia in transgenic mice lacking functional
alpha(2A) adrenoceptors and in sympathectomized wild-type mice, to determine if
sympathetic-sensory coupling generates hyperalgesia. The development of
neuropathic heat hyperalgesia required the presence of both the alpha(2A)
adrenoceptor and the sympathetic postganglionic neuron (SPGN), but the
development of mechanical hyperalgesia did not require either the alpha(2A)
adrenoceptor or the SPGN, indicating different mechanisms of sensitization. These
results suggest that the development of neuropathic heat hyperalgesia, but not
mechanical hyperalgesia, requires sympathetic-sensory coupling in the peripheral
nervous system. Nerve injury enhanced the analgesic efficacy of the alpha(2)
adrenoceptor agonist dexmedetomidine, and paradoxically also induced an analgesic
response to alpha(2) adrenoceptor antagonists. The alpha(2) agonist-evoked
analgesia to mechanical stimuli was mediated by activating central alpha(2A)
adrenoceptors, possibly at the spinal level. The peripherally restricted alpha(2)
antagonist L659,066 evoked analgesia for heat, but not for mechanical stimuli,
findings which support the hypothesis that the peripheral alpha(2) adrenoceptor
plays a role in both the development and the maintenance of neuropathic heat
hyperalgesia. The alpha(2) antagonist-evoked analgesia for heat stimuli was
mediated by blocking peripheral and probably central alpha(2) adrenoceptors,
while the analgesia for mechanical stimuli was mediated by blocking central
alpha(2A) adrenoceptors. Intradermal injections with an alpha(2) agonist or
antagonist had no effect on nociceptive thresholds, indicating that sympathetic
sensory coupling at the level of the cutaneous nociceptor did not contribute to
the maintenance of neuropathic hyperalgesia.
PMID- 10781909
TI - An fMRI study of the anterior cingulate cortex and surrounding medial wall
activations evoked by noxious cutaneous heat and cold stimuli.
AB - The anterior cingulate cortex (ACC) and adjacent regions in the medial wall have
been implicated in sensory, motor and cognitive processes, including pain. Our
previous functional magnetic resonance imaging (fMRI) studies have demonstrated
pain-related activation of the posterior portion of the ACC during transcutaneous
electrical nerve stimulation (TENS) and variable patterns of cortical activation
with innocuous and noxious thermal stimuli in individual subjects. The present
study represents the companion paper to our recent study of pain- and thermal
related cortical activations with the aim to use fMRI to delineate the
activations in the ACC and surrounding regions of the medial wall during
application of innocuous and noxious thermal stimuli as well as during
performance of a motor task in individual subjects. Ten normal subjects were
imaged on a conventional 1.5 T GE 'echospeed' system. Functional images were
obtained from sagittal sections through each hemisphere centered at approximately
3-5 and 7-9 mm from midline. Each subject was imaged during innocuous (cool,
warm) and noxious thermal (cold, hot) stimulation of the thenar eminence, and
execution of a motor (sequential finger-thumb opposition) task. Task-related
activations were mostly confined to contralateral and medial ipsilateral images.
Although the present results demonstrate intersubject variability in the task
related activations, some general modality-specific patterns were apparent: (i)
innocuous thermal-related activations were located mainly in the anterior ACC;
(ii) noxious thermal-related activations were primarily located in the anterior
ACC, the ventral portion of the posterior ACC, and the supplementary motor area
(SMA); (iii) motor-related activations were primarily located in the SMA and
dorsal portion of the posterior ACC. These results indicate that specific spatial
patterns of activation exist within the ACC and surrounding regions of the medial
wall for innocuous and noxious thermal stimuli, and that noxious thermal- and
motor-related activations appear to be segregated within the ACC. Therefore, we
propose a segregation of the ACC into an anterior non-specific attention/arousal
system and a posterior pain system.
PMID- 10781910
TI - Cognitive factors and the experience of pain and suffering in older persons.
AB - Cognitive factors are thought to play an important mediational role between pain
and consequent levels of suffering, yet there has been little investigation of
these issues in older chronic pain patients. The present study sought to examine
the reliability and validity of the Pain Locus of Control (PLOC) scale when used
with older patients, to explore age differences in PLOC orientation, and examine
the relationship between cognitive beliefs and levels of pain and suffering. 169
older patients attending a pain management clinic completed a comprehensive
psychometric battery prior to admission. Principal components analysis replicated
the original factor structure of the PLOC previously identified in young adult
samples, suggesting that older patients adopt the same underlying constructs of
control. The internal item consistency of the 36 item scale was shown to be very
good to excellent. Older adults endorsed a higher chance locus of control, but
this orientation was amenable to change following a cognitive-behavioural
treatment program. PLOC orientation was related to use of coping strategies,
levels of pain and depression, functional and psychosocial impact as well as
compliance with treatment protocols. Stepwise regression analysis revealed that
self perceived interference from pain and internal PLOC were the best predictors
of depressive symptoms in older adults. In combination, these findings suggest
that cognitive factors are of importance in older chronic pain patients and
extend the relevance of cognitive-behavioural models of pain across the entire
adult age spectrum.
PMID- 10781911
TI - Presynaptic inhibition by baclofen of miniature EPSCs and IPSCs in substantia
gelatinosa neurons of the adult rat spinal dorsal horn.
AB - Intrathecal administration of baclofen, a GABA(B)-receptor agonist, affects pain
behavior induced by formalin in a biphasic manner; baclofen at low doses enhances
pain while producing antinociception at high doses. This may be due to the fact
that baclofen modulates each of excitatory and inhibitory transmission in the
dorsal horn of the spinal cord with a distinct sensitivity, resulting in a
biphasic action on pain transmission. To address this issue, we examined the
actions of baclofen on miniature excitatory (glutamatergic) and inhibitory
(GABAergic) postsynaptic currents (mEPSCs and mIPSCs, respectively) in substantia
gelatinosa (SG) neurons of adult rat spinal cord slices by using the whole-cell
voltage-clamp technique. Baclofen reduced the frequency of both mEPSC and mIPSC
without a change in their amplitudes. These actions were dose-dependent in a
concentration range of 0.1-100 microM; the effective concentrations for the half
inhibition of mEPSC and mIPSC frequency were 4.44+/-0. 60 microM (n=7) and 4.31+/
0.77 microM (n=6), respectively. These results indicate that each of
glutamatergic and GABAergic nerve terminals in the SG is endowed with the GABA(B)
receptor, the activation of which depresses the release of neurotransmitter from
the terminal; this provides a cellular basis for the modulation of pain by
baclofen. It is suggested from a similar affinity for baclofen of the GABA(B)
receptors on both terminals that the baclofen-induced biphasic action on pain
behaviors cannot be accounted for by only its presynaptic actions in the SG and
that other actions such as an inhibitory action of baclofen on postsynaptic
neurons also have to be taken into consideration.
PMID- 10781912
TI - Spinal PKC activity and expression: role in tolerance produced by continuous
spinal morphine infusion.
AB - It has been hypothesized that spinal morphine tolerance results from protein
kinase C (PKC) mediated phosphorylation. Chronic lumbar intrathecal (i.t.)
infusion of morphine (20 nmol/microl/h) was shown to produce antinociception on
day 1 (d1) that disappeared by d5 (tolerance). On d6, a bolus i.t. probe dose of
morphine (60 nmol) produced a more profound antinociception in saline-infused
rats than in morphine-infused rats. Coinfusion of morphine with a PKC inhibitor,
chelerythrine, prevented tolerance to the probe morphine dose. Bolus i.t.
chelerythrine or GF109203X (GF), another PKC inhibitor, on d5, but not the
inactive homologue of GF Bisindolymaleimide V, also blocked development of
tolerance after 24 h. I.t. morphine infusion, but not saline, produced a 2-fold
increase in dorsal horn PKC phosphorylating activity and in the expression of
PKCalpha/gamma. Bolus chelerythrine on d5 after spinal morphine infusion blocked
upon an increase in PKC activity, confirming that at the behaviorally active dose
the drug had the intended biochemical effect upon spinal PKC activity. PKC
activity and protein expression did not change when assessed 1 h after bolus i.t.
morphine in naive rats. Thus, tolerance produced by morphine infusion is
dependent upon an increase in local phosphorylating activity by PKC. Blocking the
PKC activity prevents expression of the morphine tolerance.
PMID- 10781913
TI - Gabapentin affects glutamatergic excitatory neurotransmission in the rat dorsal
horn.
AB - We investigated the effects of gabapentin (GBP) on glutamatergic synaptic
transmission in the dorsal horn of the rat spinal cord. Patch clamp whole cell
recordings were made from superficial and deep dorsal horn neurons of rat spinal
cord slices. In the majority of neurons in the superficial lamina, GBP decreased
the amplitudes of evoked excitatory postsynaptic currents (evoked EPSCs) mediated
by either non-NMDA or NMDA receptors. In contrast, neurons in the deep lamina
showed variable effects, with a lower incidence of decrease in amplitude of
evoked EPSCs and a subset of neurons showing an increase in amplitude of evoked
NMDA receptor-mediated EPSCs. No enhancement of evoked non-NMDA receptor-mediated
EPSCs was observed in either lamina. To determine whether the observed effects of
GBP are presynaptic and/or postsynaptic, spontaneous miniature excitatory
postsynaptic currents (mEPSCs) were studied. In neurons that showed a decrease in
its frequency of mEPSCs by GBP, no change in the amplitude or shape accompanied
the effect. On the other hand, in neurons that showed an increase in the
frequency of NMDA receptor-mediated mEPSCs, the effect accompanied an increase in
amplitude. These results suggest that GBP presynaptically inhibits glutamatergic
synaptic transmission predominantly in the superficial lamina, while
postsynaptically enhancing NMDA receptor-mediated transmission in some neurons of
the deep lamina. The antinociceptive effects of GBP may involve the inhibition of
the release of excitatory amino acids from presynaptic terminals.
PMID- 10781914
TI - An evaluation of homogeneity tests in meta-analyses in pain using simulations of
individual patient data.
AB - In this paper we consider the validity and power of some commonly used statistics
for assessing the degree of homogeneity between trials in a meta-analysis. We
show, using simulated individual patient data typical of that occurring in
randomized controlled trials in pain, that the most commonly used statistics do
not give the expected levels of statistical significance (i.e. the proportion of
trials giving a significant result is not equal to the proportion expected due to
random chance) when used with truly homogeneous data. In addition, all such
statistics are shown to have extremely low power to detect true heterogeneity
even when that heterogeneity is very large. Since, in most practical situations,
failure to detect heterogeneity does not allow us to say with any helpful degree
of certainty that the data is truly homogeneous, we advocate the quantitative
combination of results only where the trials contained in a meta-analysis can be
shown to be clinically homogeneous. We propose as a definition of clinical
homogeneity that all trials have (i) fixed and clearly defined inclusion criteria
and (ii) fixed and clearly defined outcomes or outcome measures. In pain relief,
for example, the first of these would be satisfied by all patients having
moderate or severe pain, whilst the second would be satisfied by using at least
50% pain relief as the successful outcome measure.
PMID- 10781915
TI - Effects of midazolam in the spinal nerve ligation model of neuropathic pain in
rats.
AB - Potential changes in the spinal GABAergic activity after nerve injury were
studied by comparing the effects of systemic administration of the benzodiazepine
midazolam on the noxious evoked responses of dorsal horn in rats with spinal
nerve ligation of neuropathy and control animals. The tight ligation of the L(5)
and L6 spinal nerves was performed in adult male Sprague-Dawley rats and
resulting mechanical and cold allodynia were assessed with von Frey hairs and the
acetone drop test. Single unit extracellular recordings of dorsal horn neurones
were performed 15-18 days after the surgery under halothane anaesthesia using
transcutaneous electrical stimulation of the receptive field at three times the C
fibre threshold. The rats in the spinal nerve ligation group, but not in the sham
operated control group developed mechanical and cold allodynia. Subcutaneous
administration of midazolam 0.1-3.0 mg/kg reduced the Adelta-fibre evoked
activity in a dose-related manner in all study groups, but the C-fibre evoked
activity was significantly reduced only in the spinal nerve ligation group. The
inhibitory effects of s.c. midazolam were significantly reversed by i.t.
administration of flumazenil, suggesting a spinal site of action. Midazolam
reduced C-fibre evoked firing significantly more in the spinal nerve ligation
model than in the non-operated or sham controls. These results indicate changes
in the spinal GABAergic system in the neuropathic animals and could be of
importance in the development of new treatments for neuropathic pain.
PMID- 10781916
TI - Unaltered peripheral excitatory actions of nociceptin contrast with enhanced
spinal inhibitory effects after carrageenan inflammation: an electrophysiological
study in the rat.
AB - Nociceptin (orphanin FQ) is the endogenous agonist of the opioid receptor-like
(ORL-1) receptor. The actions of this peptide have been studied extensively at a
number of sites with diverse actions being reported. Here, in a rat model of
peripheral inflammation, we examine the effects of nociceptin on the responses of
dorsal horn neurones when applied directly to the spinal cord and, in separate
studies, into the peripheral receptive fields in the hindpaw of the halothane
anaesthetized rat. As changes in the receptor density and expression of the
message for nociceptin have been reported after inflammation we have compared
these actions to previously reported effects in normal animals. The dose
dependent inhibitory actions of nociceptin on C-fibre evoked responses and input
(measures of presumed pre-synaptic excitability) are increased 3-4 h after
inflammation whereas its inhibitory effects on post-synaptic mechanisms (wind-up)
remain unchanged. These inhibitory effects were partly reversible by high doses
of naloxone. This increased potency of nociceptin after inflammation is
consistent with an increased receptor density in the superficial spinal cord. In
contrast, the peripheral administration of nociceptin produced dose-dependent
excitations of dorsal horn neurones and a degree of sensitization to mechanical
stimuli. This peripheral action was unchanged after inflammation. These diverse
site-dependent actions of nociceptin further emphasize the complexities of this
novel opioid system.
PMID- 10781917
TI - Analgesic and toxic effects of ABT-594 resemble epibatidine and nicotine in rats.
AB - The present study directly compared the antinociceptive and toxic effects of the
neuronal nicotinic receptor agonist ABT-594 ((R)-5-(2-azetidinylmethoxy)-2
chloropyridine) with (-)-nicotine and (+)-epibatidine. Like (-)-nicotine (0.8 and
1.6 mg/kg s.c.) and (+)-epibatidine (0.005 and 0.01 mg/kg s.c.), ABT-594 (0.05
and 0.1 mg/kg s.c.) increased response latencies in the hot-plate test in rats,
indicating that it has antinociceptive activity. In contrast to (-)-nicotine and
(+)-epibatidine, ABT-594 did not cause rotarod impairment at antinociceptive
doses but did cause hypothermia and life-threatening adverse effects including
seizures. ABT-594 (0.01 and 0.1 mg/kg i.v.) also produced a dose-dependent
increase in blood pressure resembling that observed with (-)-nicotine (0.03, 0.1
and 0. 03 mg/kg i.v.) and (+)-epibatidine (0.001 and 0.003 mg/kg i.v.). Both the
antinociceptive and toxic effects (convulsions and hypertension) were abolished
by pretreatment with the brain penetrant neuronal nAChR antagonist mecamylamine
(1 mg/kg s.c.; i.v. for cardiovascular studies), demonstrating that these actions
of ABT-594 were mediated via activation of neuronal nicotinic receptors.
Continuous infusion of ABT-594 (0.2 mg/kg per day s.c.) to rats for 7 days
followed by challenge with mecamylamine (1 mg/kg i.p.) induced a nicotine-like
abstinence syndrome suggesting that ABT-594 has nicotine-like dependence
liability. These findings indicate that the acute safety profile of ABT-594 is
not significantly improved over other nicotinic analgesics.
PMID- 10781918
TI - Some empirical evidence regarding the validity of the Spanish version of the
McGill Pain Questionnaire (MPQ-SV).
AB - Despite the fact that the McGill Pain Questionnaire (MPQ) is a useful pain
assessment tool with widespread acceptance, empirical analyses have questioned
its validity because they have not consistently supported the three a priori
factors that guided its construction. The Spanish version that has followed the
most systematic and rigorous reconstruction process (Lazaro C, Bosch F, Torrubia
R, Banos JE. The development of a Spanish Questionnaire for assessing pain:
preliminary data concerning reliability and validity. Eur J Psychol Assess,
1994;10:145-151) lacks evidence to support its construct validity. In the present
study, the internal structure of the Spanish version of the McGill Pain
Questionnaire (Lazaro C, Bosch F, Torrubia R, Banos JE. The development of a
Spanish Questionnaire for assessing pain: preliminary data concerning reliability
and validity. Eur J Psychol Assess, 1994;10:145-151) was examined in a sample of
202 acute pain patients and 207 chronic pain patients. Confirmatory factor
analyses were carried out to compare alternative models postulating different
internal structures (one-factor model, the classic three-factor model, and the
semantic model inspired by the alternative structure found by Donaldson in 1995
(Donaldson GW. The factorial structure and stability of the McGill Pain
Questionnaire in patients experiencing oral mucositis following bone marrow
transplantation. Pain 1995;62:101-109)). Results from the LISREL CFA analysis
indicated that the semantic model fitted better than the other models. On the
other hand, intercorrelations between scales were smaller than the reliability
indexes. In relation to concurrent evidence, significant correlations (0.001)
were found between each subscale and the criteria measurements of every pain
dimension. Only the affective subscale presented discriminant validity. Evidence
supports the validity of the affective and sensory subscales but not the
evaluative scale.
PMID- 10781919
TI - Simple pain rating scales hide complex idiosyncratic meanings.
AB - Assumptions of reliability and consistency of self-report of pain by patients
using visual analogue scales (VAS) and numerical rating scales (NRS) are based on
narrow considerations of possible sources of error. This study examined patients'
use of VASs and NRSs, by their own description, with particular attention to
rating of multiple pains, of different dimensions of pain, and of interpretation
and use of lower and upper endpoints and increments on the scales. These have
implications for the approximation of the scales to psychometric requirements. An
interview developed from a small pilot project was given to 78 volunteer chronic
pain patients embarking on a pain management course, and consisted of both forced
choice questions and free response. Data are described with reference to lack of
concordance between patients and of consistency within patients; responses
suggested that ratings incorporate multiple partially differentiated dimensions
of pain, with particular importance placed on function or mobility. Labels
assigned to scale endpoints by researchers, whether lexical or numerical,
appeared to affect their use; however, covert relabelling of scale points was
revealed in free response. The action of arriving at a rating is better
conceptualised as an attempt to construct meaning, influenced by and with
reference to a range of internal and external factors and private meanings,
rather than as a task of matching a distance or number to a discrete internal
stimulus.
PMID- 10781920
TI - Synergistic effect of cholecystokinin octapeptide and angiotensin II in reversal
of morphine induced analgesia in rats.
AB - The aim of this paper is to study the synergistic anti-analgesic effect of
angiotensin II (Ang II) plus cholecystokinin octapeptide (CCK-8). Our previous
studies have shown that both CCK-8 and Ang II are potent anti-opioid substances.
Intracerebroventricular (i.c.v.) injection of CCK-8 or Ang II dose-dependently
antagonizes morphine-induced analgesia (MIA). In the present study, we observed
the combined effect of CCK-8 and Ang II in antagonizing MIA. CCK-8 and Ang II
were injected intracerebroventricularly to rats in various proportions and doses.
The results were analyzed with isobolographic analysis. Combined injection of CCK
8 and Ang II in a ratio of 1 ng: 2.5 microg or 1 ng: 5 microg produced
significantly greater effect in antagonizing MIA. The ED(50) of the two ratios
are only 18.5% and 27.5%, respectively, of the theoretical dose of simple
addition. We conclude that CCK-8 and Ang II used in such dose ratios may
antagonize MIA synergistically.
PMID- 10781921
TI - Alexithymia is associated with low tolerance to experimental painful stimulation.
AB - Alexithymics are known to report more somatic complaints than individuals scoring
low on alexithymia. It was examined whether alexithymia would also be associated
with enhanced sensitivity to an externally administered unpleasant physical
stimulus. Forty-one healthy male and female subjects with a mean age of 33.9
years completed the 20-item version of the Toronto Alexithymia Scale and
participated in a laboratory protocol consisting of exposure to painful electric
stimulation. Multiple stepwise regression analyses revealed that after
controlling for sensory threshold, duration of stimulation, and self-reported
caffeine consumption, alexithymia predicted significantly pain tolerance level
(beta=-0.33, P=0.01). Externally oriented thinking and difficulty identifying
feelings, but not difficulty communicating feelings, were responsible for this
association. Previous findings and the present results together indicate that
alexithymia may be associated with an enhanced sensitivity to both internal
(somatic) unpleasant sensations and externally induced pain, suggesting a
potential general hypersensitivity to unpleasant stimuli in individuals scoring
high on this trait.
PMID- 10781922
TI - Hyperalgesia and upregulation of cytokines and nerve growth factor by cutaneous
leishmaniasis in mice.
AB - Classical description of syndromes produced by cutaneous leishmaniasis (CL) does
not include sensory manifestations such as pain and/or itching, despite the
evident upregulation of proinflammatory cytokines. Using a murine model of CL we
report on evident hyperalgesia, as assessed by acute pain tests, and sustained
upregulation of interleukin (IL-1beta) and nerve growth factor (NGF). This
upregulation, especially that of NGF, may explain the observed hyperalgesia, in
the light of recent evidence on the role of cytokines in the sensitization of
nerve afferents and the subsequent hyperalgesia.
PMID- 10781923
TI - Ketamine reduces muscle pain, temporal summation, and referred pain in
fibromyalgia patients.
AB - Central mechanisms related to referred muscle pain and temporal summation of
muscular nociceptive activity are facilitated in fibromyalgia syndrome (FMS)
patients. The present study assessed the effects of an NMDA-antagonist (ketamine)
on these central mechanisms. FMS patients received either i.v. placebo or
ketamine (0.3 mg/kg, Ketalar((R))50% decrease in pain intensity at rest by active
drug on two consecutive VAS assessments). Fifteen out of 17 ketamine-responders
were included in the second part of the study. Before and after ketamine or
placebo, experimental local and referred pain was induced by intramuscular (i.m.)
infusion of hypertonic saline (0.7 ml, 5%) into the tibialis anterior (TA)
muscle. The saline-induced pain intensity was assessed on an electronic VAS, and
the distribution of pain drawn by the subject. In addition, the pain threshold
(PT) to i.m. electrical stimulation was determined for single stimulus and five
repeated (2 Hz, temporal summation) stimuli. The pressure PT of the TA muscle was
determined, and the pressure PT and pressure pain tolerance threshold were
determined at three bilaterally located tenderpoints (knee, epicondyle, and mid
upper trapezius). VAS scores of pain at rest were progressively reduced during
ketamine infusion compared with placebo infusion. Pain intensity (area under the
VAS curve) to the post-drug infusion of hypertonic saline was reduced by ketamine
(-18. 4+/-0.3% of pre-drug VAS area) compared with placebo (29.9+/-18.8%,
P<0.02). Local and referred pain areas were reduced by ketamine (-12. 0+/-14.6%
of pre-drug pain areas) compared with placebo (126.3+/-83. 2%, P<0.03). Ketamine
had no significant effect on the PT to single i.m. electrical stimulation.
However, the span between the PT to single and repeated i.m. stimuli was
significantly decreased by the ketamine (-42.3+/-15.0% of pre-drug PT) compared
with placebo (50. 5+/-49.2%, P<0.03) indicating a predominant effect on temporal
summation. Mean pressure pain tolerance from the three paired tenderpoints was
increased by ketamine (16.6+/-6.2% of pre-drug thresholds) compared with placebo
(-2.3+/-4.9%, P<0.009). The pressure PT at the TA muscle was increased after
ketamine (42.4+/-9. 2% of pre-drug PT) compared with placebo (7.0+/-6.6%,
P<0.011). The present study showed that mechanisms involved in referred pain,
temporal summation, muscular hyperalgesia, and muscle pain at rest were
attenuated by the NMDA-antagonist in FMS patients. It suggested a link between
central hyperexcitability and the mechanisms for facilitated referred pain and
temporal summation in a sub-group of the fibromyalgia syndrome patients. Whether
this is specific for FMS patients or a general phenomena in painful
musculoskeletal disorders is not known.
PMID- 10781924
TI - Mechanical hyperalgesia after an L5 spinal nerve lesion in the rat is not
dependent on input from injured nerve fibers.
AB - An injury to a peripheral nerve in animals often leads to signs of neuropathic
pain including hyperalgesia to heat, cold and mechanical stimuli. The role of
injured and intact nerve fibers in mechanical hyperalgesia was evaluated in rats
subjected to an L5 spinal nerve ligation-and-cut ('modified SNL lesion'). To
assess the contribution of injured afferents, an L5 dorsal rhizotomy was
performed immediately before, or 7 days after the modified SNL lesion. To study
the role of adjacent intact spinal nerves, an L4 dorsal rhizotomy was performed 7
days after the modified SNL lesion. The up-down method of Dixon (Dixon WJ, Annu
Rev Pharmacol Toxicol 1980;20:441-462) was used to measure the paw withdrawal
threshold to mechanical stimuli at three sites on the rat hindpaw corresponding
to the L3, L4, and L5 dermatomes. We found that the modified SNL lesion produced
a significant, lasting (20 days) decrease of the mechanical withdrawal threshold.
The severity and duration of mechanical hyperalgesia varied across testing sites.
The L5 and L4 dermatome test sites developed the most severe and lasting
mechanical hyperalgesia. In contrast, the L3 testing site developed significantly
less severe and shorter lasting mechanical hyperalgesia. L5 dorsal rhizotomy, by
itself, produced a transient decrease in mechanical withdrawal thresholds. L5
dorsal rhizotomy performed before, or 7 days after, the modified SNL lesion did
not prevent or resolve the observed decrease in mechanical withdrawal thresholds.
L4 dorsal rhizotomy performed 7 days after the modified SNL lesion resulted in an
immediate reversal of mechanical withdrawal thresholds back to baseline values.
These results suggest that, after L5 spinal nerve ligation-and-cut, mechanical
hyperalgesia develops and persists independent of input from injured afferents.
We propose that the Wallerian degeneration that develops after a nerve injury
leads to interactions between the degenerating fibers of the injured spinal nerve
and the intact fibers of adjacent spinal nerves. This leads to changes in the
intact fibers that play a critical role for both initiation and maintenance of
mechanical hyperalgesia.
PMID- 10781925
TI - Tactile allodynia in the absence of C-fiber activation: altered firing properties
of DRG neurons following spinal nerve injury.
AB - We examined the relation between ectopic afferent firing and tactile allodynia in
the Chung model of neuropathic pain. Transection of the L5 spinal nerve in rats
triggered a sharp, four- to six-fold increase in the spontaneous ectopic
discharge recorded in vivo in sensory axons in the ipsilateral L5 dorsal root
(DR). The increase, which was not yet apparent 16 h postoperatively, was complete
by 24 h. This indicates rapid modification of the electrical properties of the
neurons. Only A-neurons, primarily rapidly conducting A-neurons, contributed to
the discharge. No spontaneously active C-neurons were encountered. Tactile
allodynia in hindlimb skin emerged during precisely the same time window after
spinal nerve section as the ectopia, suggesting that ectopic activity in injured
myelinated afferents can trigger central sensitization, the mechanism believed to
be responsible for tactile allodynia in the Chung model. Most of the spike
activity originated in the somata of axotomized DRG neurons; the spinal nerve end
neuroma accounted for only a quarter of the overall ectopic barrage.
Intracellular recordings from afferent neuron somata in excised DRGs in vitro
revealed changes in excitability that closely paralleled those seen in the DR
axon recordings in vivo. Corresponding changes in biophysical characteristics of
the axotomized neurons were catalogued. Axotomy carried out at a distance from
the DRG, in the mid-portion of the sciatic nerve, also triggered increased
afferent excitability. However, this increase occurred at a later time following
axotomy, and the relative contribution of DRG neuronal somata, as opposed to
neuroma endings, was smaller. Axotomy triggers a wide variety of changes in the
neurochemistry and physiology of primary afferent neurons. Investigators studying
DRG neurons in culture need to be alert to the rapidity with which axotomy, an
inevitable consequence of DRG excision and dissociation, alters key properties of
these neurons. Our identification of a specific population of neurons whose
firing properties change suddenly and synchronously following axotomy, and whose
activity is associated with tactile allodynia, provides a powerful vehicle for
defining the specific cascade of cellular and molecular events that underlie
neuropathic pain.
PMID- 10781926
TI - Regulation of adenylyl cyclase in the central nervous system.
AB - Adenylyl cyclases (ACs) are a family of enzymes that synthesize one of the major
second messengers, cAMP, upon stimulation. Since the report of the first adenylyl
cyclase (AC) gene in 1989, tremendous efforts have been devoted to identifying
and characterizing more AC isozymes. In the past decade, significant knowledge
regarding the basic structure, tissue distribution, and regulation of AC isozymes
has been accumulated. Because members of the AC superfamily are tightly
controlled by various signals, one of the most important impacts of these AC
isozymes is their contribution to the complexity and fine-tuning of cellular
signalling, especially in the central nervous system (CNS) where multiple signals
constantly occur. This review focuses on recent progress toward understanding the
physiological roles of ACs in the CNS.
PMID- 10781927
TI - Activation of mitogen-activated protein kinase by oxidized low-density
lipoprotein in canine cultured vascular smooth muscle cells.
AB - Oxidized low-density lipoprotein (OX-LDL) contributes significantly to the
development of atherosclerosis. However, the mechanisms of OX-LDL-induced
vascular smooth muscle cell (VSMC) proliferation are not completely understood.
Therefore, we investigated the effect of OX-LDL on cell proliferation associated
with a specific pattern of mitogen-activated protein kinase (MAPK) by
[3H]thymidine incorporation and p42/p44 MAPK phosphorylation in canine cultured
VSMCs. OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK
phosphorylation in a time- and concentration-dependent manner in VSMCs.
Pretreatment of these cells with pertussis toxin (PTX) for 24 hours attenuated
the OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK phosphorylation,
indicating that these responses were mediated through a receptor coupled to a PTX
sensitive G protein. In cells pretreated with PMA for 24 h and with either the
PKC inhibitor staurosporine or the tyrosine kinase inhibitor genistein for 1h,
substantially reduced the [3H]thymidine incorporation and p42/p44 MAPK
phosphorylation in response to OX-LDL. Removal of Ca(2+) by addition of BAPTA/AM
plus EGTA significantly inhibited OX-LDL-induced [3H]thymidine incorporation and
p42/p44 MAPK phosphorylation, indicating the requirement of Ca(2+) for these
responses. OX-LDL-induced [3H]thymidine incorporation and p42/p44 MAPK
phosphorylation was completely inhibited by PD98059 (an inhibitor of MEK1/2) and
SB203580 (an inhibitor of p38 MAPK). Furthermore, we also showed that
overexpression of dominant negative mutants of Ras (RasN17) and Raf (Raf-301)
completely suppressed MEK1/2 and p42/p44 MAPK activation induced by OX-LDL and
PDGF-BB, indicating that Ras and Raf may be required for activation of these
kinases. Taken together, these results suggest that the mitogenic effect of OX
LDL is mediated through a PTX-sensitive G-protein-coupled receptor that involves
the activation o Ras/Raf/MEK/MAPK pathway similar to those of PDGF-BB in canine
cultured VSMCs.
PMID- 10781929
TI - Effect of pertussis toxin on insulin-induced signal transduction in rat
adipocytes and soleus muscles.
AB - It has been reported that pertussis toxin (PTX) suppresses the function of
trimeric guanine nucleotide binding protein (G-protein). We examined the effect
of PTX on insulin-induced glucose uptake, diacylglycerol (DG)-protein kinase C
(PKC) signalling, phosphatidylinositol (PI) 3-kinase and PKC zeta activation and
insulin-induced tyrosine phosphorylation of Gialpha to clarify the role of G
protein for insulin-mediated signal transduction mechanism in rat adipocytes and
soleus muscles. Isolated adipocytes and soleus muscles were preincubated with
0.01 approximately 1 ng/ml PTX for 2 hours, followed by stimulation with 10-100
nM insulin or 1 microM tetradecanoyl phorbol-13-acetate (TPA). Pretreatment with
PTX resulted in dose-responsive decreases in insulin-stimulated [3H]2
deoxyglucose (DOG) uptake, and unchanged TPA-stimulated [3H]2-DOG uptake, without
affecting basal [3H]2-DOG uptake. In adipocytes, insulin-induced DG-PKC
signalling, PI 3-kinase activation and PKC zeta translocation from cytosol to the
membrane were suppressed when treated with PTX, despite no changes in
[125I]insulin-specific binding and insulin receptor tyrosine kinase activity.
Moreover, to elucidate insulin-stimulated tyrosine phosphorylation of 40 kDa
alpha-subunit of G-protein (Gialpha-2), adipocytes were stimulated with 10 nM
insulin for 10 minutes, homogenized, immunoprecipitated with anti-phosphotyrosine
antibody, and immunoblotted with anti-Gialpha-2 antibody. Insulin-induced
tyrosine phosphorylation of Gialpha-2 was found by immunoblot analysis with anti
Gialpha-2 antibody. These results suggest that G-protein regulates DG-PKC
signalling by binding of Gialpha-2 with GTP and PI 3-kinase-PKC zeta signalling
by releasing of Gbetagamma via dissociation of trimeric G-protein after insulin
receptor tyrosine phosphorylation in insulin-sensitive tissues.
PMID- 10781928
TI - Increase of [Ca(2+)]i and release of arachidonic acid via activation of M2
receptor coupled to Gi and rho proteins in oesophageal muscle.
AB - We have previously shown that acetylcholine-induced contraction of oesophageal
circular muscle depends on activation of phosphatidylcholine selective
phospholipase C and D, which result in formation of diacylglycerol, and of
phospholipase 2 which produces arachidonic acid. Diacylglycerol and arachidonic
acid interact synergistically to activate protein kinase C. We have therefore
investigated the relationship between cytosolic Ca(2+) and activation of
phospholipase A(2) in response to acetylcholine-induced stimulation, by measuring
the intracellular free Ca(2+) ([Ca(2+)]i), muscle tension, and [3H] arachidonic
acid release. Acetylcholine-induced contraction was associated with increased
[Ca(2+)]i and arachidonic acid release in a dose-dependent manner. In Ca(2+)-free
medium, acetylcholine did not produce contraction, [Ca(2+)]i increase, and
arachidonic acid release. In contrast, after depletion of Ca(2+) stores by
thapsigargin (3 microM), acetylcholine caused a normal contraction, [Ca(2+)]i
increase and arachidonic acid release. The increase in [Ca(2+)]i and arachidonic
acid release were attenuated by the M2 receptor antagonist methoctramine, but not
by the M3 receptor antagonist p-fluoro-hexahydro siladifenidol. Increase in
[Ca(2+)]i and arachidonic acid release by acetylcholine were inhibited by
pertussis toxin and C3 toxin. These findings indicate that contraction and
arachidonic acid release are mediated through muscarinic M2 coupled to Gi or rho
protein activation and Ca(2+) influx. Acetylcholine-induced contraction and the
associated increase in [Ca(2+)]i and release of arachidonic acid were completely
reduced by the combination treatment with a phospholipase A(2) inhibitor
dimethyleicosadienoic acid and a phospholipase D inhibitor pCMB. They increased
by the action of the inhibitor of diacylglycerol kinase R59949, whereas they
decreased by a protein kinase C inhibitor chelerythrine. These data suggest that
in oesophageal circular muscle acetylcholine-induced [Ca(2+)]i increase and
arachidonic acid release are mediated through activation of M2 receptor coupled
to Gi or rho protein, resulting in the activation of phospholipase A(2) and
phospholipase D to activate protein kinase C.
PMID- 10781930
TI - Nitric oxide selectively inhibits adenylyl cyclase isoforms 5 and 6.
AB - We have previously shown that N18TG2 neuroblastoma cells express the type 6
adenylyl cyclase and that preincubation with nitric oxide (NO) attenuates Gs- and
forskolin-stimulated activity. Here we show that this inhibition reflects a
direct action of NO on the adenylyl cyclase. Preincubation of N18TG2 cell
membranes and insect cell membranes expressing recombinant type 5 and type 6
isoforms with NO donors leads to an inhibition of forskolin-stimulated adenylyl
cyclase activity. NO donors do not alter the type 1 (representative of the type
1,3,8 family) or type 2 (representative of the type 2,4, 7 family) isoforms
expressed in insect cells, even under conditions of compromised assay conditions
or a range of temperatures. Thus, the ability of NO to inhibit adenylyl cyclase
stimulation is dependent upon the nature of the isoform present, and appears to
represent a unique regulation of the type 5,6 isoform family.
PMID- 10781931
TI - Mastoparan transiently permeabilizes Swiss 3T3 cells and induces c-fos proto
oncogene expression. Role of calcium and G protein activation.
AB - Mastoparan, a widely used tetradecapeptide activator of Gi/Go G proteins, has
been reported to be a potent co-mitogen for Swiss 3T3 fibroblasts. However, we
have previously shown that the peptide promotes the release of lactate
dehydrogenase from Swiss 3T3 cells and evokes only a modest and delayed increase
in DNA. We suggested that the ability of the peptide to permeabilise these cells
may account for its mitogenic action. Here we show that mastoparan caused a rapid
release of fluorescein from cells which had been pre-incubated with fluorescein
diacetate, indicating that the peptide increases membrane permeability to small
molecules. Furthermore, the release of lactate dehydrogenase evoked by mastoparan
was lost after prolonged (24 h) incubation of cells with the peptide. Together,
these data indicate that mastoparan-induced cell permeabilisation is both rapid
and transient. We have also shown that mastoparan increased c-fos mRNA
accumulation and that this response was not influenced by pertussis toxin or
indomethacin. Although mastoparan increased the intracellular calcium
concentration, the removal of extracellular calcium had no effect on mastoparan
stimulated c-fos mRNA accumulation. These data show that mastoparan-induced c-fos
mRNA accumulation is not mediated by activation of a G protein and subsequent
activation of phospholipase D nor by a non-selective increase in calcium influx.
The data have significance for the interpretation of studies in which mastoparan
is, or has been, used as an activator of Gi/Go.
PMID- 10781932
TI - Role and regulation of Rel/NF-kappaB activity in anti-immunoglobulin-induced
apoptosis in WEHI-231 B lymphoma cells.
AB - In WEHI-231 cells, anti-immunoglobulin (anti-Ig) treatment leads to both a
decrease in the DNA-binding activity of p50/c-Rel/p53 protein complexes and a
transient enhancement in the DNA-binding activity of p50 homodimeric complexes.
These cells subsequently undergo apoptosis. Because IkappaB-alpha plays a pivotal
role in the regulation of Rel/NF-kappaB activity, we have characterized both the
nature and kinetics of the expression of IkappaB-alpha following anti-Ig-induced
apoptosis in WEHI-231 cells. Anti-Ig treatment of WEHI-231 cells decreased the
steady-state level of IkappaB-alpha mRNA, but enhanced the stability of IkappaB
alpha, leading to an accumulation of IkappaB-alpha in both the cytosol and
nucleus. Concomitant with the increase in IkappaB-alpha expression there was a
gradual decline in the nuclear expression of c-Rel. Because c-Rel plays an
important role in the survival of WEHI-231 cells, these results suggest that post
transcriptional regulation of IkappaB-alpha expression might play a role in the
anti-Ig-induced apoptosis in WEHI-231 cells.
PMID- 10781934
TI - Novel effects of propranolol. Release of internal Ca(2+) followed by activation
of capacitative Ca(2+) entry in Madin Darby canine kidney cells.
AB - The effect of propranolol on Ca(2+) signalling in Madin Darby canine kidney
(MDCK) cells was investigated by using fura-2 as a Ca(2+) probe. Propranolol
increased cytosolic free Ca(2+) levels ([Ca(2+)](i)) in a concentration-dependent
manner between 0.1 and 1 mM. The response was partly inhibited by external Ca(2+)
removal. In Ca(2+)-free medium pretreatment with 0.2 mM propranolol partly
inhibited the [Ca(2+)](i) rise induced by 1 microM thapsigargin, an inhibitor of
the endoplasmic reticulum Ca(2+) pump; but pretreatment with thapsigargin
abolished propranolol-induced Ca(2+) release. Addition of 3 mM Ca(2+) induced a
[Ca(2+)](i) rise after pretreatment with 0.2 mM propranolol in Ca(2+)-free
medium. Propranolol (0.2 mM) inhibited 25% of thapsigargin-induced capacitative
Ca(2+) entry. Suppression of 1,4,5-trisphosphate (IP(3)) formation by 2 microM
U73122, a phospholipase C inhibitor, did not alter 0.2 mM propranolol-induced
internal Ca(2+) release. Propranolol (1 mM) also increased [Ca(2+)](i) in human
neutrophils. Collectively, we have found that 0.2 mM propranolol increased
[Ca(2+)](i) in MDCK cells by releasing Ca(2+) from thapsigargin-sensitive Ca(2+)
stores in an IP(3)-independent manner, followed by Ca(2+) influx from external
space. Independently, propranolol was able to inhibit thapsigargin-induced
capacitative Ca(2+) entry.
PMID- 10781933
TI - Novel action of pituitary adenylate cyclase-activating polypeptide. Stimulation
of extracellular acidification in rat pituitary GH4C1 cells.
AB - Pituitary adenylate cyclase-activating polypeptide (PACAP) is a member of the
vasoactive intestinal peptide/secretin family. Using microphysiometry, we have
found that PACAP acutely (1 min) increased the extracellular acidification rate
(ECAR) in GH4C1 cells approximately 40% above basal in a concentration-dependent
manner. ECAR, maximally induced by PACAP, can be increased further by thyrotropin
releasing hormone (TRH), indicating that the signalling pathways for these two
neuropeptides are not identical. In studies on the mechanism of PACAP-enhanced
ECAR, we found that maximum stimulation of the cAMP/PKA pathway by treatment with
FSK, or the PKC pathway with PMA, did not inhibit the ECAR response to PACAP. The
PKC inhibitor calphostin C and the MAP kinase inhibitor PD98059 had no effect on
the ECAR response to PACAP. Furthermore, PACAP induced little or no change in
cytosolic Ca(2+) ([Ca(2+)](i)), while TRH induced a large increase in
[Ca(2+)](i). However, the tyrosine kinase inhibitor genistein completely blocked
PACAP-induced ECAR, suggesting involvement of tyrosine kinase(s). We conclude
that PACAP causes an increase in ECAR in GH4C1 rat pituitary cells, which is not
dependent on the PKA, PKC, MAP kinase or Ca(2+) signalling pathways, but does
require tyrosine kinase activity.
PMID- 10781935
TI - Dorsal induction from dorsal vegetal cells in Xenopus occurs after mid-blastula
transition.
AB - We performed some experiments to investigate the temporal and spatial details of
the dorsal induction exerted by dorsal vegetal cells in Xenopus embryo. Two
dorsal vegetal cells (D1 cells) were transplanted into the ventral vegetal region
of a recipient at the 32-cell stage. At various times after transplantation, the
ventral animal-equatorial part was explanted and cultured. The explants isolated
5.5 h after transplantation (time 5.5) elongated and formed somites. In RT-PCR
analysis, the expression of dorsal gene, chordin was activated in the explants
isolated after time 4.0 (about the 4000-cell stage which corresponds to the mid
blastula transition (MBT)) at control stage 10. In another series of experiments,
ventral animal-equatorial and dorsal vegetal parts were isolated from the 4000
cell stage embryos and they were combined for 2.0-2.5 h. These ventral animal
equatorial explants elongated and formed somites. The chordin expression was also
observed in the explants. But the 32- and 256-cell stage dorsal vegetal cells
failed to exert the dorsalizing activity within the 2.0-2.5 h of the conjugation.
These results suggest that 2 h contact after MBT is necessary and sufficient for
the dorsal induction from the dorsal vegetal cells and it occurs as a result of
the zygotic gene expression. Consistent with this idea, the zygotic dorsal genes,
siamois and chordin were expressed on the upper regions of the transplanted D1
descendants at stage 10. Furthermore, this region began to gastrulate when the D1
cell was transplanted with upside-down orientation. Our data indicate that the
upper region of the D1 descendants by itself act as the Spemann organizer rather
than the Nieuwkoop center.
PMID- 10781936
TI - Drosophila null slimb clones transiently deregulate Hedgehog-independent
transcription of wingless in all limb discs, and induce decapentaplegic
transcription linked to imaginal disc regeneration.
AB - Drosophila Slimb (Slmb) is a F-box/WD40 protein which potentially participates in
the ubiquitin proteolysis machinery. During development, Slmb is required in limb
discs to repress Hedgehog (Hh) target genes, i.e. wingless (wg) and
decapentaplegic (dpp), as well as the Wg signal transduction pathway. These
repression functions have been proposed from studies using weak slmb alleles.
Interestingly, experiments with strong slmb alleles have revealed additional
mechanisms in which slmb is required, such as leg dorsal-ventral restriction. We
have isolated new alleles of the slmb gene in a screen for new negative
regulators of dpp: several amorphs (characterized by genetic and molecular
criteria) and a cold-sensitive hypomorph. By performing somatic clone experiments
with these new amorphic slmb alleles, we have determined that regulation of Dpp
and Wg morphogens by Slmb could be different from what has already been
published. We show here that in leg discs, lack of slmb function derepresses the
transcription of wg independently of Hh signaling. We present evidence that
ectopic legs resulting from slmb(-) clone induction only come from wg
misexpression in the normal dpp domain, as ectopic proximo-distal axis are
induced dorsally, and adult ectopic legs are often perfect with respect to antero
posterior polarity. In wing discs, transcription of wg, which is normally
independent of Hh signaling, is also derepressed in the absence of slmb function.
We also describe, in discs bearing amorphic slmb clones and in discs of two other
slmb(-) contexts, a novel pattern of dpp expression consisting of an enlargement
of the normal dpp domain. Strong evidence indicates that this dpp modification
can be linked to imaginal disc regeneration following slmb(-) cell elimination.
We have investigated the fate of slmb(-) clones, which disappear before
adulthood, and found that two mechanisms of cell elimination can account for
imaginal cell regeneration: an early apoptosis and a mechanism of sorting-out
which excludes all slmb(-) clones from all imaginal discs. This result suggests
that Slmb is likely to be involved, in addition to its repression role on Dpp and
Wg, in some other essential cellular mechanism, as in the absence of Slmb, cell
affinities are dramatically modified regardless of the deregulated morphogen and
of the type of imaginal disc.
PMID- 10781937
TI - A screen for targets of the Xenopus T-box gene Xbra.
AB - Brachyury (T), a member of the T-box gene family, is essential for the formation
of posterior mesoderm and notochord in vertebrate development. Expression of the
Xenopus homologue of Brachyury, Xbra, causes ectopic ventral and lateral mesoderm
formation in animal cap explants and co-expression of Xbra with Pintallavis, a
forkhead/HNF3beta-related transcription factor, induces notochord. Although eFGF
and the Bix genes are thought to be direct targets of Xbra, no other target genes
have been identified. Here, we describe the use of hormone-inducible versions of
Xbra and Pintallavis to construct cDNA libraries enriched for targets of these
transcription factors. Five putative targets were isolated: Xwnt11, the homeobox
gene Bix1, the zinc-finger transcription factor Xegr-1, a putative homologue of
the antiproliferative gene BTG1 called Xbtg1, and BIG3/1A11, a gene of unknown
function. Expression of Xegr-1 and Xbtg1 is controlled by Pintallavis alone as
well as by a combination of Xbra and Pintallavis. Overexpression of Xbtg1
perturbed gastrulation and caused defects in posterior tissues and in notochord
and muscle formation, a phenotype reminiscent of that observed with a dominant
negative version of Pintallavis called Pintallavis-En(R). The Brachyury-inducible
genes we have isolated shed light on the mechanism of Brachyury function during
mesoderm formation. Specification of mesodermal cells is regulated by targets
including Bix1-4 and eFGF, while gastrulation movements and perhaps cell division
are regulated by Xwnt11 and Xbtg1.
PMID- 10781938
TI - FGF and genes encoding transcription factors in early limb specification.
AB - SnR, twist and Fgf10 are expressed in presumptive limb territories of early chick
embryos. When FGF-2/FGF-8 beads are implanted in chick flank, an ectopic limb
develops and SnR is irreversibly activated as early as 1 h. Ectopic Fgf10 and
twist expression are activated much later at 17 and 20 h, respectively. FGF-10
can also induce SnR, but much later, and in this case activation occurs
simultaneously with that of twist and Fgf10 via the Fgf8- expressing ridge. Tbx-4
and Tbx-5 are expressed in leg and wing forming regions, respectively, in a
similar pattern to SnR and twist. FGF-2 leads to ectopic expression of Tbx-4 and
Tbx-5 as rapidly as ectopic expression of SnR, but the patterns of ectopic
transcripts suggest that induction of SnR and Tbx gene expression occur via
different pathways.
PMID- 10781939
TI - Neuroectodermal specification and regionalization of the Spemann organizer in
Xenopus.
AB - During gastrulation in Xenopus convergence and extension movements, mediated by
mediolateral intercalations, are the driving force for early neural plate
morphogenesis. Here we show that the winged helix transcriptional regulator, Xfd
12' is dynamically expressed in medial neural plate precursors that undergo
convergence and extension movements. These medial neuraxial progenitors are
specified in and beyond the Spemann organizer prior to specification of the basal
anlage of the neural plate. The initiation of Xfd-12' expression coincides with
the induction of mesendoderm by Nodal-related growth factors at the late blastula
stage. Comparative expression analysis suggests that cellular rearrangements at
the pre-gastrulation stage account for regionalization of the Spemann organizer
into head and trunk organizer compartments, the latter in which medial neural
plate progenitors reside. While the maintenance of Xfd-12' expression in the
dorsal non-involuting marginal zone requires FGF signalling, its subsequent
positioning along the medial aspect of the neuraxis depends on signalling by Wnt
and Nodal-related family members. Based on these findings we propose that XFD-12'
is a trunk organizer component that might control convergence and extension
movements of medial neural plate precursors during gastrulation.
PMID- 10781940
TI - Expanded retina territory by midbrain transformation upon overexpression of Six6
(Optx2) in Xenopus embryos.
AB - During vertebrate eye development, the expression of the homeobox gene Six6 is
restricted to the neural retina and is initiated later than Rx and Pax6 in the
presumptive retina field. We show here that overexpression of mouse Six6 in
Xenopus embryos can induce transformation of competent tissue of the anterior
neural plate into retinal tissue. In Six6 injected embryos, the molecular
identity of the presumptive midbrain and rostral hindbrain regions was lost, as
shown by the absence of XEn-2 and Xpax2 expression, being replaced by the ectopic
expression of the retinal markers Xpax6 and Xrx. When allowed to grow further,
Six6 injected embryos developed ectopic eye-like structures in the rostral brain
and showed a transformation of the midbrain into retina. Similar results were
obtained upon overexpression of Six3 or Xsix3, revealing a possible redundance of
Six3 and Six6 activities. Taken together, results obtained suggest that during
normal retina development, the relatively late expressed Six6 gene becomes part
of a network of retinal homeobox genes that are linked together by positive
feedback loops. Furthermore, our results demonstrate that the primitive neural
ectoderm of the future midbrain and rostral hindbrain is competent to form
retinal tissue.
PMID- 10781941
TI - Smad7 is a TGF-beta-inducible attenuator of Smad2/3-mediated inhibition of
embryonic lung morphogenesis.
AB - Smad7 was recently shown to antagonize TGF-beta-induced activation of signal
transducing Smad2 and Smad3 proteins. However, the biological function of Smad7
in the process of lung organogenesis is not known. Since Smad2/3-mediated TGF
beta signaling is known to inhibit embryonic lung branching morphogenesis, we
tested the hypothesis that Smad7 regulates early lung development by modulating
TGF-beta signal transduction. An antisense oligodeoxynucleotide (ODN) was
designed to specifically block endogenous Smad7 gene expression at both
transcriptional and translational levels in embryonic mouse lungs in culture. TGF
beta-mediated inhibition of lung branching morphogenesis was significantly
potentiated in cultured embryonic lungs in the absence of Smad7 gene expression:
abrogation of Smad7 potentiated TGF-beta-mediated inhibition of lung branching
morphogenesis from 76 to 52% of the basal level in lungs cultured in the presence
of 5 ng/ml TGF-beta1 ligand. Likewise, TGF-beta1 EC(50) (concentration of TGF
beta1 that induced half maximal branching inhibition) was reduced from 5 to 1
ng/ml when Smad7 gene expression was abrogated in lung culture, indicating an
enhanced level of TGF-beta signaling in lung tissue with abolished Smad7 gene
expression. By immunocytochemistry, Smad7 protein was co-localized with both
Smad2 and Smad3 in distal bronchial epithelial cells, supporting the concept that
Smad7 inhibits TGF-beta signaling by competing locally with Smad2 and Smad3 for
TGF-beta receptor complex binding during lung morphogenesis. Furthermore,
antisense Smad7 ODN increased the negative effect of TGF-beta1 on epithelial cell
growth in developing lungs in culture. We also demonstrated that Smad7 mRNA
levels were rapidly and potently induced upon TGF-beta1 stimulation of lungs in
culture, suggesting that Smad7 regulates TGF-beta responses in a negative
feedback loop. These studies define a novel function for Smad7 as an
intracellular antagonist of TGF-beta-induced, Smad2/3-mediated inhibition of
murine embryonic lung growth and branching morphogenesis in culture. The
optimization of TGF-beta signaling during early lung development therefore
requires a finely-regulated competitive balance between both permissive and
inhibitory members of the Smad family.
PMID- 10781942
TI - Distinct role of protein phosphatase 2A subunit Calpha in the regulation of E
cadherin and beta-catenin during development.
AB - Protein phosphatase 2A (PP2A) plays central roles in development, cell growth and
transformation. Inactivation of the gene encoding the PP2A catalytic subunit
Calpha by gene targeting generates a lethal embryonic phenotype. No mesoderm is
formed in Calpha(-/-) embryos. Here, we found that during normal early embryonic
development Calpha was predominantly present at the plasma membrane whereas the
highly homologous isoform Cbeta was localized to the cytoplasm and nuclei,
suggesting the inability of Cbeta to compensate for vital functions of Calpha in
Calpha(-/-) embryos. In addition, PP2A was found in a complex containing the PP2A
substrates E-cadherin and beta-catenin. In Calpha(-/-) embryos, E-cadherin and
beta-catenin were redistributed from the plasma membrane to the cytosol.
Cytosolic concentrations of beta-catenin were low. Our results suggest that
Calpha is required for stabilization of E-cadherin/beta-catenin complexes at the
plasma membrane.
PMID- 10781943
TI - Plexin/neuropilin complexes mediate repulsion by the axonal guidance signal
semaphorin 3A.
AB - In the developing nervous system axons navigate with great precision over large
distances to reach their target areas. Chemorepulsive signals such as the
semaphorins play an essential role in this process. The effects of one of these
repulsive cues, semaphorin 3A (Sema3A), are mediated by the membrane protein
neuropilin-1 (Npn-1). Recent work has shown that neuropilin-1 is essential but
not sufficient to form functional Sema3A receptors and indicates that additional
components are required to transduce signals from the cell surface to the
cytoskeleton. Here we show that members of the plexin family interact with the
neuropilins and act as co-receptors for Sema3A. Neuropilin/plexin interaction
restricts the binding specificity of neuropilin-1 and allows the receptor complex
to discriminate between two different semaphorins. Deletion of the highly
conserved cytoplasmic domain of Plexin-A1 or -A2 creates a dominant negative
Sema3A receptor that renders sensory axons resistant to the repulsive effects of
Sema3A when expressed in sensory ganglia. These data suggest that functional
semaphorin receptors contain plexins as signal-transducing and neuropilins as
ligand-binding subunits.
PMID- 10781944
TI - Disrupted development of the cerebral hemispheres in transgenic mice expressing
the mammalian Groucho homologue transducin-like-enhancer of split 1 in
postmitotic neurons.
AB - Transducin-like Enhancer of split (TLE) 1 is a mammalian transcriptional
corepressor homologous to Drosophila Groucho. In Drosophila, Groucho acts
together with bHLH proteins of the Hairy/Enhancer of split (HES) family to
negatively regulate neuronal differentiation. Loss of the functions of Groucho or
HES proteins results in supernumerary central and peripheral neurons. This
suggests that mammalian TLE/Groucho family members may also be involved in the
regulation of neuronal differentiation. Consistent with this possibility, TLE1 is
expressed in proliferating neural progenitor cells of the central nervous system,
but its expression is transiently down-regulated in newly generated postmitotic
neurons. Based on these observations, we investigated whether persistent TLE1
expression in postmitotic neurons would perturb the normal course of neuronal
development. Transgenic mice were derived in which the human TLE1 gene is
regulated by the promoter of the Talpha1 alpha-tubulin gene, which is exclusively
expressed in postmitotic neurons. In these mice, constitutive expression of TLE1
inhibits neuronal development in the embryonic forebrain leading to increased
apoptosis and neuronal loss in the ventral and dorsal telencephalon. These
results provide the first direct evidence that TLE1 is an important negative
regulator of postmitotic neuronal differentiation in the mammalian central
nervous system.
PMID- 10781945
TI - Identification of a C-rich element as a novel cytoplasmic polyadenylation element
in Xenopus embryos.
AB - During Xenopus early development, the length of the poly(A) tail of maternal
mRNAs is a key element of translational control. Several sequence elements
(cytoplasmic polyadenylation elements) localized in 3' untranslated regions have
been shown to be responsible for the cytoplasmic polyadenylation of certain
maternal mRNAs. Here, we demonstrate that the mRNA encoding the catalytic subunit
of phosphatase 2A is polyadenylated after fertilization of Xenopus eggs. This
polyadenylation is mediated by the additive effects of two cis elements, one
being similar to already described cytoplasmic polyadenylation elements and the
other consisting of a polycytosine motif. Finally, a candidate specificity factor
for polycytosine-mediated cytoplasmic polyadenylation has been purified and
identified as the Xenopus homologue of human alpha-CP2.
PMID- 10781946
TI - Involvement of pannier and u-shaped in regulation of decapentaplegic-dependent
wingless expression in developing Drosophila notum.
AB - In developing Drosophila notum, wingless expression is regulated by
Decapentaplegic signaling positively and negatively so that only notal cells
receiving optimal levels of Decapentaplegic signals express wingless (Sato et
al., 1999b. Development 126, 1457-1466). Here, we show evidence that this
Decapentaplegic-dependent regulation of notal wingless expression includes plural
mechanisms, involving pannier and u-shaped. In the medial notum, Pannier and U
shaped form a complex (Haenlin et al., 1997. Genes Dev. 11, 3096-3108). The
expression of pannier and u-shaped is positively regulated by Decapentaplegic
signals emanating from the dorsal-most region. The Pannier/U-shaped complex
serves as a repressor and a transcriptional activator, respectively, for wingless
and u-shaped expression. In the more lateral region, wingless expression is up
regulated by U-shaped-unbound Pannier. wingless expression is also weakly
regulated by its own signaling.
PMID- 10781947
TI - Expression and intracellular localization of mouse Vasa-homologue protein during
germ cell development.
AB - To demonstrate the cellular and subcellular localization of mouse vasa homologue
protein during germ cell development, specific antibody was raised against the
full-length MVH protein. The immunohistochemical analyses demonstrated that MVH
protein was exclusively expressed in primordial germ cells just after their
colonization of embryonic gonads and in germ cells undergoing gametogenic
processes until the post-meiotic stage in both males and females. The co-culture
of EG cells with gonadal somatic cells indicated inductive MVH expression caused
by an intercellular interaction with gonadal somatic cells. In adult testis, MVH
protein was localized in the cytoplasm of spermatogenic cells, including
chromatoid bodies in spermatids, known to be a perinuclear nuage structure which
includes polar granules that contain VASA protein in Drosophila.
PMID- 10781948
TI - A green fluorescent protein enhancer trap screen in Drosophila photoreceptor
cells.
AB - The Drosophila ommatidia contain two classes of photoreceptor cells (PR's), the
outer and the inner PR's. We performed an enhancer trap screen in order to target
genes specifically expressed in PR's. Using the UAS/GAL4 method with enhanced
green fluorescent protein (eGFP) as a vital marker, we screened 180000 flies. Out
of 2730 lines exhibiting new eGFP patterns, we focused on 16 lines expressing
eGFP in particular subsets of PR's. In particular, we describe three lines
inserted near the spalt major, m-spondin and furrowed genes, whose respective
expression patterns resemble those genes. These genes had not been reported to be
expressed in the adult eye. These examples clearly show the ability of our screen
to target genes expressed in the adult Drosophila eye.
PMID- 10781949
TI - Expression of zebrafish fkd6 in neural crest-derived glia.
AB - The zebrafish fkd6 gene is a marker for premigratory neural crest. In this study,
we analyze later expression in putative glia of the peripheral nervous system.
Prior to neural crest migration, fkd6 expression is downregulated in crest cells.
Subsequently, expression appears initially in loose clusters of cells in
positions corresponding to cranial ganglia. Double labelling with a neuronal
marker shows that fkd6-expressing cells are not differentiated neurones and
generally lie peripheral to neurones in ganglia. Later, expression appears
associated with the posterior lateral line and other cranial nerves. For the
posterior lateral line nerve, we show that fkd6-labeling extends caudally along
this nerve in tight correlation with lateral line primordium migration and axon
elongation. Expression in colourless mutant embryos is consistent with these
cells being satellite glia and Schwann cells.
PMID- 10781950
TI - Expression domains of murine ephrin-A5 in the pituitary and hypothalamus.
AB - Using in situ hybridization on whole-mounts and sections of mouse embryos we have
visualized the pattern of expression for the Eph receptor ligand ephrin-A5. Non
neuronal expression domains include the ectoderm of the branchial arches, the
ectoderm and mesenchyme surrounding the dorsal root ganglia, the intervertebral
discs, maxillary and mandibulary mesenchymal elements as well as the nasal
mesenchyme and ectoderm. Within the developing nervous system, ephrin-A5
expression is very dynamic. Besides the midbrain it is also expressed in the
hypothalamus, and the neurohypophysis that we studied here in more detail.
Hypothalamus expression of ephrin-A5 demarks distinct nuclei, persists throughout
embryonic development, and can be seen also in the adult.
PMID- 10781952
TI - A novel member of the testis specific serine kinase family, tssk-3, expressed in
the Leydig cells of sexually mature mice.
AB - We have recently characterized two members of a novel family of murine testis
specific serine kinases, tssk-1 and tssk-2, expressed exclusively in spermatids
undergoing spermiogenesis. Using a differential screening approach we have
isolated a third family member, tssk-3. The open reading frame of tssk-3 encodes
a protein of 275 amino acids, consisting essentially of a serine/threonine
protein kinase domain only. In contrast, tssk-1 and -2 have distinct,
approximately 100 amino acid domains located C-terminally to the kinase domain.
Immunoprecipitation experiments revealed that while tssk-1 and tssk-2 form
detergent resistant complexes, tssk-3 is not associated with either protein.
Expression of tssk-3 was induced at puberty, persisted during adulthood and was
restricted to the interstitial Leydig cells of post-pubertal males.
PMID- 10781951
TI - Glycosylation of phytepsin and expression of dad1, dad2 and ost1 during onset of
cell death in germinating barley scutella.
AB - Dysfunction and downregulation of dad (defending against death) has been linked
to programmed cell death (PCD) in animals and plants. As DAD is an essential
subunit of the oligosaccharyltransferase that is located in the ER membrane, the
results have raised the possibility that downregulation of N-linked glycosylation
could be involved in the regulation of PCD. Here we show that the 16 kDa subunit
of phytepsin, a vacuolar proteinase, is normally processed and glycosylated at
the onset of DNA fragmentation in germinating barley scutella. Two cDNA clones
encoding dad (dad1, dad2), and one cDNA encoding another subunit of the same
oligosaccharyltransferase complex (ost1) were isolated from barley. Northern
analysis of germinating scutella show that the expression of only dad1 is
declining before onset of DNA fragmentation. In contrast to this, the expression
of both dad2 and ost1 increase before onset of DNA fragmentation.
PMID- 10781953
TI - Distinct and common developmental expression patterns of the murine Pkd2 and Pkd1
genes.
AB - Autosomal dominant polycystic kidney disease (ADPKD) is one of the most commonly
inherited renal diseases. At least two genes, PKD2 and PKD1 are implicated in the
development of this disease. Our pathogenetic studies showed that the human and
murine polycystic kidney disease (PKD) involves failure to switch out of a renal
developmental program. We have thus undertaken a detailed comparative expression
analysis of Pkd2 and Pkd1 from the morula stage to adulthood. Pkd2 expression was
detected as early as the morula and blastocyst stages as observed for Pkd1.
Strong Pkd2 expression, similar to Pkd1, was displayed in all mesenchymal and
cartilaginous tissues during mouse development. However major differences in Pkd2
expression in comparison to Pkd1 were identified. First, in contrast to Pkd1, the
neural crest cell-derived tissues displayed a low to undetectable Pkd2 expression
at all ages. Second, no increase in Pkd2 expression was detected during
mesenchymal condensation. Third, high Pkd2 expression in the kidneys was
localized mainly to the tubular epithelium of the cortical region from murine
development to adulthood.
PMID- 10781954
TI - A Drosophila group E Sox gene is dynamically expressed in the embryonic
alimentary canal.
AB - We have identified a novel Drosophila Sox-domain gene, Sox100B, related to the
vertebrate group E genes Sox9 and Sox10. In vertebrates, group E Sox genes are
expressed in the developing gonad, adult kidney and gut as well as other tissues.
During embryogenesis in Drosophila, Sox100B is expressed in two rows of large
intestinal cells, in midgut basophilic cells, in the Malpighian tubules and at
the posterior cap of gonadal mesoderm. Our observations indicate that aspects of
tissue-specific expression, as well as sequence, are conserved between vertebrate
and invertebrate group E Sox proteins.
PMID- 10781955
TI - Regional and cellular specificity of the expression of TPRD, the
tetratricopeptide Down syndrome gene, during human embryonic development.
AB - The TPRD gene (tetratricopeptide (TPR) containing Down syndrome gene) is one of
the candidate genes in the Down syndrome chromosomal region-1. Duplication of
this gene may be the cause of major phenotypic features of Down syndrome. Here we
show that the TPRD expression is developmentally regulated during human
embryogenesis. At the earliest stages of development (Carnegie 8-12) TPRD
expression is ubiquitous. At later developmental stages (Carnegie stages 14, 16
and 18), it becomes restricted to the nervous system, as is the case for the
mtprd gene during mouse development. We extended our analysis of TPRD expression
during fetal development of the human nervous system (13, 22 and 24 weeks). A new
oblique illumination technique was used to compare signal intensity and cell
density. Some regions of the nervous system such as the external cortical layers
of the brain, and the inner neuroblastic layer of the eye, strongly express the
TPRD gene.
PMID- 10781956
TI - Characterization of avian frizzled genes in cranial placode development.
AB - To determine the possible role of Wnt signaling in cranial placode development,
we have cloned several chick frizzled genes, a family of putative Wnt receptor
molecules, and analyzed their expression during chick embryogenesis. Chick
frizzled-2 (cFz-2) and frizzled-7 (cFz-7) are expressed broadly in cranial
ectoderm, tissue that is competent to express markers of the trigeminal placode
(Stark et al., 1997. Development 124, 4287-4295; Baker et al., 1999. Development
126, 147-156). In addition, cFz-2 and cFz-7 are uniquely expressed in other
cranial placodes, including the olfactory, lens, and otic placodes. Chick
frizzled-1 (cFz-1) is expressed in the lens, otic placode and, along with cFz-7,
in epibranchial placodes. Each frizzled gene expressed in the otic placode
displays a unique domain of expression: cFz-1 transcripts are detected in the
medial wall of the vesicle, cFz-2 in the rostral rim of the vesicle, and cFz-7 in
the lateral half of the vesicle. Other chick frizzled family members cloned that
do not show striking expression in cranial placodes include frizzled-4 (cFz-4),
frizzled-8 (cFz-8), frizzled-9 (cFz-9), and frizzled-10 (cFz-10). A brief summary
of their expression is given, along with a brief summary of non-placodal
expression of cFz-1, cFz-2, and cFz-7. In all, frizzled genes show dynamic
expression at key times during embryonic development, particularly in the cranial
placodes.
PMID- 10781957
TI - Cloning and expression of a novel zinc finger gene, Fez, transcribed in the
forebrain of Xenopus and mouse embryos.
AB - We have identified and cloned a novel zinc finger gene, Fez (forebrain embryonic
zinc-finger), as a potential downstream determinant of anterior neural plate
formation in Xenopus. Fez was isolated as one of several neural-specific genes
that was induced by the neuralizing factor, noggin (Smith and Harland, 1992. Cell
70, 829-840), in uncommitted ectoderm. Fez has an open reading frame comprising
466 amino acids, and contains six C(2)H(2) type zinc finger domains, which are
highly conserved among Drosophila, zebrafish, mouse, and human. In Xenopus, the
expression of Fez begins at stage 12 in the rostral end of the neural plate, and
by stage 45, it is localized to several telencephalic regions, including the
olfactory bulbs, nervus terminalis, and ventricular zone. The mouse homologue of
Fez is similarly expressed in the mouse forebrain by embryonic day 11.
PMID- 10781958
TI - Vegetal localization of the maternal mRNA encoding an EDEN-BP/Bruno-like protein
in zebrafish.
AB - Asymmetric distribution of maternal mRNAs has not been well documented in
zebrafish. Recently, we have shown that dazl mRNA is localized at the vegetal
pole. Here we report a novel zebrafish gene, bruno-like (brul), which provides
another example of vegetal mRNA localization. brul encodes an Elav-type RNA
binding protein that belongs to the Bruno-like family that includes mammalian CUG
BP, Xenopus EDEN-BP, and Drosophila Bruno. At 24 hpf, brul mRNA was abundant in
lens fiber cells. At the onset of embryogenesis, maternal brul mRNA was detected
at the vegetal pole, and it then migrated rapidly toward the blastoderm through
yolk cytoplasmic streams. During oogenesis, brul mRNA became localized at the
vegetal cortex at stage II, later than dazl mRNA. We found that anchoring of brul
mRNA was dependent on microfilaments.
PMID- 10781960
TI - Sox neuro, a new Drosophila Sox gene expressed in the developing central nervous
system.
AB - We describe the identification and detailed expression pattern of a second
Drosophila Sox gene, SoxNeuro (SoxN), highly related to mammalian group B Sox1,
2, 3 genes. SoxN is expressed in a highly dynamic pattern during embyogenesis,
being associated with the development of the central nervous system (CNS), from
the early steps onwards. We present strong evidence that the early SoxN
neuroectoderm expression is controlled by the zygotic dorso-ventral patterning
genes (dpp, sog, brk, twi).
PMID- 10781959
TI - The HMG-box transcription factor XTcf-4 demarcates the forebrain-midbrain
boundary.
AB - A small subfamily of HMG-box transcription factors, the LEF/TCF group, serves as
nuclear transducer of the Wnt-1/Wg signaling cascade. Upon Wnt-1/Wg signaling
their members interact with beta-catenin and regulate the expression of Xenopus
target genes siamois, twin, nodal related-3 or fibronectin. We have isolated a
new HMG-box transcription factor in Xenopus that will be addressed XTcf-4 based
on its homology to human and murine Tcf-4. Unlike XTcf-3, which is a maternal
gene, and XLef-1 that is expressed after mid blastula transition (Molenaar et
al., 1998. Mech. Dev. 75, 151-154), XTcf-4 expression starts at late neurula
stage and is restricted to the anterior most midbrain demarcating the forebrain
midbrain boundary. The expression partially overlaps with a broad set of Xenopus
Wnt family members in distinct patterns. XTcf-4 transcripts were also found
partially co-localized with those of Xaxin, an intracellular antagonist of Wnt
1/Wg signaling.
PMID- 10781961
TI - Formin-2, a novel formin homology protein of the cappuccino subfamily, is highly
expressed in the developing and adult central nervous system.
AB - Formin-1 is the founding member of a family of genes of emerging biological and
medical importance that share specific domains of homology, allowing them to be
classified together as the formin homology proteins. Although deficiency
mutations in formin-1 lead to profound developmental defects in limb and kidney
formation, similar deficiency mutations in more distantly related members of this
family (diaphanous and cappuccino in Drosophila and BNI1 in yeast) have
ostensibly unrelated phenotypes. Here we describe murine and human formin-2
(Fmn2), a gene which bears a high degree of similarity to formin-1 and
cappuccino. The mouse gene, which encodes a putative 1567-amino-acid open reading
frame and maps to mouse Chromosome 1, is expressed almost exclusively in the
developing and mature central nervous system. Expression begins at embryonic day
9. 5 in the developing spinal cord and brain structures and continues in neonatal
and adult brain structures including the olfactory bulb, cortex, thalamus,
hypothalamus, hippocampus and cerebellum. Human formin-2 has a similar expression
pattern.
PMID- 10781962
TI - Xerl: a novel secretory protein expressed in eye and brain of Xenopus embryo.
AB - A novel gene, Xerl (Xenopus EGF-like repeat with laminin-G domain protein) was
isolated from a Xenopus head cDNA library prepared from tailbud. This gene
encoded 779 amino acids including a potential signal sequence, twelve EGF-like
repeats, a laminin-G domain, a RGD sequence and a VWF motif. In the EGF-like
repeat and the laminin-G domain, Xerl showed similarity to those of Drosophila
Crumbs, respectively. Zygotic expression of Xerl began at late gastrula, and
increased through neurula up to the tailbud stage. In adult organs, Xerl was
detected in brain and eye. Whole-mount in situ hybridization showed that Xerl
expression occurred first in the anterior bilateral region of neurula and
gradually localized to retina and forebrain and boundaries of midbrain and
hindbrain.
PMID- 10781963
TI - A century of change - a future of challenge.
PMID- 10781964
TI - Contraception - consumer perspectives; past, present and future.
PMID- 10781965
TI - Estimating the balance of general practice versus family planning clinic coverage
of contraception services in London.
AB - OBJECTIVE: To compare levels of provision of contraception from general practice
and family planning clinics for the populations of the 32 London Boroughs.
METHOD: Retrospective analysis of routine activity data, including the estimated
numbers of first attendance, for 295 family planning clinics (managed by 28 NHS
Trusts) and more than 1800 GP partnerships in Greater London, supplemented by
data from a survey of family planning clinics. The results were expressed as the
estimated percentage of women aged 16-49 obtaining advice on contraception from
GPs and family planning clinics. These results were compared to those expected
based on results in the General Household Survey. RESULTS: Across London in
1995/96, 12% of women aged 16-49 obtained contraception services from family
planning clinics, and 24% obtained contraception services from a GP. At a borough
level there was variation from 11% to 25% in coverage by family planning clinics,
and from 11% to 41% in coverage by GPs. Estimates of the proportion of women in
this age group not using NHS-provided medical or surgical contraception ranged
from 0 to 30%. Across all boroughs, there was no consistent relationship between
levels of GP activity and family planning clinic activity. CONCLUSION: The
results indicate substantial variations between boroughs in the proportion of
women using NHS-provided medical or surgical methods of contraception. The
absence of any clear inverse relationship between activity in family planning
clinics and activity in general practice suggests that changes to one will not be
compensated by changes in the other. More specifically, health authorities that
opt to purchase lower levels of family planning clinic activity cannot assume
that women may opt to use GPs as an alternative. Such a strategy may increase the
likelihood that women who would have used family planning clinic services will
either not use contraception at all, or will use less effective 'over the
counter' methods.
PMID- 10781966
TI - Quality of information on emergency contraception on the Internet.
AB - OBJECTIVE: To evaluate the quality of patient information about emergency
contraception on the Internet. DESIGN: We performed an on-line search of the
Internet and found relevant World Wide Web sites by combining the key phrases
'emergency contraception' and 'patient information' in two Web subject guides and
two search engines. We defined quality as the extent to which the characteristics
of a Web site satisfied its stated and implied objectives. Our assessment focused
on credibility and content of each Web site. Credibility was assessed by source,
currency and editorial review process and content of Web site was assessed by
hierarchy and accuracy of evidence. RESULTS: Our search revealed 32 relevant Web
sites, none of which complied with all of the criteria for quality of credibility
and content. Twenty-eight Web sites displayed the source clearly, 17 Web sites
showed currency, and none of the Web sites had an editorial review process. Only
six of the 32 sites mentioned hierarchy of evidence. None of the Web sites
depicted all the criteria for accuracy of contents. CONCLUSION: None of the Web
sites provided complete information to patients about emergency contraception
according to the quality criteria used in this study. As previous studies have
shown, people need to be wary about the quality of information on the Internet.
PMID- 10781967
TI - Sexual and reproductive rights: statements, rhetoric and responsibilities.
AB - The current international movement for the promotion of reproductive health has
great potential for improving sexual and reproductive rights. Health
professionals should play a major role in applying international human rights
instruments at the country level. Being at the front line of service delivery,
health professionals have a duty to ensure that those rights are articulated in
routine care by empowering individuals, lobbying for legislation, promoting
policies and reporting violations of human rights treaties.
PMID- 10781968
TI - Depo provera discussion paper on clinical care, effectiveness and side effects
AB - Recent changes to the health services have led to an increased provision of
clinical care in family planning clinics. While some women may only require
contraceptive services, others may demand advice on a breadth of lifestyle
issues, including diet and nutrition. Obesity affects 17% of women of
childbearing age in Scotland and being overweight during pregnancy has
significant health risks. A postal survey of 227 nurses identified as working in
family planning clinics in Scotland was conducted in 1998. After a mail shot and
one reminder, a net response rate of 64% (n = 145) was achieved. Overall, it was
found that obesity was perceived as the most extensive problem in women of
childbearing age. Seventy nurses (48%) reported that, in addition to offering
family planning services, they gave dietary advice 'frequently' or 'always' to
their clients without being asked. There were differences in nutrition-related
activities in consultations between nurses offering family planning services only
and those who routinely offered nutritional advice. Over half (61%) of the nurses
reported that they would give advice regarding weight management even if the
patients were not seeking help, although there was no significant difference
between the two comparison groups. In some cases, the nutritional advice offered
to clients highlighted a deficit in training. Most nutrition education came from
diploma and/or training courses and scientific literature, followed by
'experience'. Those nurses already embracing a nutritional advice and guidance
role were more interested in further nutrition training (p = 0.018) than the
other nurses. However, overall, 67% of the nurses wished to train further in
nutrition and weight management. The findings suggest that family planning nurses
should be supported to develop nutritional advice and guidance skills, and that
there is a pressing need for training in public health nutrition and weight
management for nurses working in family planning services.
PMID- 10781969
TI - 'CE-Marking' on contraceptive devices: what does it mean?
PMID- 10781970
TI - Contraceptive devices and the medical devices directive.
AB - The Medical Devices Agency (MDA), an executive agency of the Department of
Health, has responsibility for the safety of medical devices within the UK. The
MDA is responsible for enforcing the European Medical Devices Directive (MDD)
within the UK. Contraceptive devices such as copper-containing IUDs and condoms
are regulated by the MDD, and this brief report is an introduction to it.
PMID- 10781971
TI - Endoscopy--40 years since fiber optics. Any light at the end of the tunnel?
PMID- 10781972
TI - Abdominal stoma fashioned by a used circular stapler.
AB - A method of application of a used circular stapler in abdominal stoma formation
is described. The procedure is rapid, simple, carries less tissue trauma than the
conventional methods and does not involve any additional cost. It allows for a
precise circular aperture in the abdominal wall which may be optimally adjusted
to the bowel diameter. This method seems to minimize the occurrence of stomal
complications and particularly the incidence of troublesome parastomal hernias.
PMID- 10781973
TI - Differences between experts and trainees in the motion pattern of the dominant
upper limb during intracorporeal endoscopic knotting.
AB - BACKGROUND: Very little research has been carried out on the ergonomics of
surgeon-instrument interface. The aim of this study is to investigate the effect
of experience on the motion pattern of the dominant upper limb during endoscopic
intracorporeal knot tying. METHODS: Two groups of 5 surgeons (expert consultants
and higher surgical trainees) tied 360 surgeon's knots inside an endoscopic
trainer in a random sequence. Motion analysis at the elbow and shoulder joints of
the dominant upper limb was carried out using 3-dimensional kinemetrix system.
Each knot was distracted using a tensiometer. The endpoints were the execution
time, knot quality score, angular velocity and range of movement. Kruskal-Wallis
one-way analysis of variance and Mann-Whitney U test were used for analysis.
RESULTS: The expert group had a better knot quality score (p < 0.005) and shorter
execution time (p < 0.0001) than beginners. Motion analysis at the shoulder joint
showed that experts had a higher angular velocity (p < 0.05) and a wider range of
movement with more adduction (p < 0.01) compared to beginners. No significant
differences were found at the elbow. CONCLUSION: The better task performance by
expert surgeons is associated with controlled rapid manipulations and a wider
range of movement at the shoulder joint of the dominant upper limb.
PMID- 10781974
TI - Seromuscular enteric pedicles and prosthetic aortic graft complications in a
porcine abdominal trauma model. An experimental study.
AB - BACKGROUND/AIMS: Abdominal vascular trauma may require prosthetic grafting
despite peritoneal contamination by concurrent visceral injury. This study tested
the use of vascularized, seromuscular enteric pedicles (VSEP) against the
development of vascular prosthetic complications, in a porcine abdominal trauma
model. METHODS: Eight pigs underwent aortic transection and reconstruction with a
Dacron interposition graft (DIG). A standard bacterial inoculum soaked the DIG in
situ. An enteric segment was isolated on its mesenteric pedicle, and the mucosa
stripped. This VSEP was wrapped around the DIG and oversewn. Animals received
antibiotics for 5 days. Endpoints were 2-week survival, or evidence of sepsis.
The animals underwent explantation of the DIG, VSEP, and native aorta for the
purposes of histological, and microbiological analyses, and scanning electron
microscopy (SEM). Outcome measures were graft infection, graft thrombosis, tissue
incorporation, and anastomotic integrity. RESULTS: Two pigs were excluded for
perioperative death. All study group animals (n = 6), survived 2 weeks. Infection
and thrombosis were found in 0/6 (0%). Incorporation and anastomotic integrity
were evident in 6/6 (100%). VSEP had intact blood supplies. SEM demonstrated
viable muscle, microcirculation, and fibroplasia in VSEP. CONCLUSION: We conclude
that VSEP may help prevent prosthetic graft complications in the contaminated
setting.
PMID- 10781975
TI - Perforated gastric ulcer.
AB - BACKGROUND/AIMS: Reports about perforated gastric ulcer are scarce and thus it is
difficult to settle for a uniform model of operative management. The purpose of
the study was to review our experience with perforated gastric ulcer and evaluate
the results of gastric resection vs. oversewing of the perforation. METHODS:
Within 36 years 77 patients with peritonitis caused by histologically confirmed
perforated gastric ulcer were operated. Furthermore, in another 7 microscopic
examination revealed that perforation occurred within the gastric cancer. There
were twice as many male as female patients. RESULTS: Recently, the overall
postoperative mortality (20. 8%) tended to decrease markedly. 32 patients (mean
age 49.9 years) were submitted to gastric resection and this procedure was
associated with 2.9% mortality. All 3 subjects in whom vagotomy, pyloroplasty and
wedge resection of the ulcer had been performed survived. In 40 patients (mean
age 61.5 years) only a suture of the ulcer was performed. This procedure was
associated with high mortality (1/3 of patients died). Selection criteria
included poor general medical status, age, comorbidities, and substantial
progression of the inflammatory process. CONCLUSION: Authors believe that
emergency gastrectomy is a safe procedure; however, it might be performed without
excessive operative risk in only half of the patients.
PMID- 10781976
TI - Hepatectomy using an ultrasonically activated scalpel for hepatocellular
carcinoma.
AB - BACKGROUND: The first retrospective studies were performed to compare the
efficacy of the ultrasonic cavitational aspirator (aspirator group) and the
ultrasonically activated scalpel (scalpel group) for hepatic resection in
patients with hepatocellular carcinoma. PATIENTS AND METHODS: The aspirator group
consisted of 8 patients (6 with liver cirrhosis and 2 with chronic hepatitis in
the nontumorous liver), and the scalpel group of 7 patients (6 with liver
cirrhosis and 1 with chronic hepatitis). All patients underwent limited hepatic
resection, and the intermittent Pringle maneuver was applied during hepatic
transection. RESULTS: There were no significant differences in preoperative
hepatic function, type of hepatectomy, tumor size and maximum cross-sectional
area of the resected specimen between the 2 groups. The amount of intraoperative
blood loss was significantly less in the scalpel group than in the aspirator
group (684 versus 1,859 ml, p < 0.05). The operation time was significanly
shorter in the scalpel group than in the aspirator group (176 versus 262 min, p <
0.05). There were no significant differences in postoperative liver function and
morbidity between the 2 groups. CONCLUSIONS: The ultrasonically activated scalpel
is effective in reducing blood loss and in shortening the time of operation, and
can be employed during limited resection of the liver with cirrhosis or chronic
hepatitis.
PMID- 10781977
TI - A continuing role for surgical bypass in the palliative treatment of pancreatic
carcinoma.
AB - BACKGROUND: The use of palliative surgery for irresectable pancreatic cancer has
been challenged by the advent of non-operative stenting, but it may still be
appropriate for selected patients. METHODS: Single-loop biliary and gastric
bypass was carried out in 56 patients (mean age 60 years) with carcinomas of the
pancreatic head that were irresectable because of vascular invasion or distant
spread. In 42 patients without a preoperative tissue diagnosis, ductal carcinoma
was confirmed by biopsy of the primary (n = 20) or secondary (n = 22) tumour.
Preoperative biliary decompression in 31 patients led to positive bile cultures
in 22 of 24 patients sampled. RESULTS: There were no deaths in hospital or within
30 days. Complications in 20 patients (35%) included three biliary leaks, two of
which required temporary percutaneous stents. The median postoperative hospital
stay was 14 days. No re-operations were required before death, though 2 patients
required percutaneous stenting of the biliary anastomosis for recurrent jaundice,
1 of whom had a radiation-induced stricture. The median survival was 6 (range 2
21) months. CONCLUSION: Combined biliary and gastric bypass can be carried out
with reasonable safety and remains a useful option for patients with potentially
resectable tumours and an anticipated life expectancy of at least 6 months.
PMID- 10781978
TI - Poor outcome of a defunctioning stoma after pouch construction for ulcerative
colitis.
AB - BACKGROUND: Restorative proctocolectomy for ulcerative colitis can have
complications necessitating a later defunctioning ileostomy with uncertain
outcome. This analysis was undertaken to assess the outcome in patients needing a
later defunctioning ileostomy after pouch construction in patients with
ulcerative colitis. METHOD: The notes of our series of 154 patients who underwent
restorative proctocolectomy and ileal pouch-anal anastomosis for ulcerative
colitis were reviewed and 28 patients identified who needed a later defunctioning
ileostomy to deal with complications. RESULTS: A later defunctioning ileostomy
was necessary in 28 patients to deal with the following complications: sepsis in
11 patients (5 pouches failed), fistulas in 7 (5 pouches failed), poor function
including ileoanal stenosis in 5 (all 5 failed), postoperative intraabdominal
bleeding in 2 (both saved), pouchitis in 2 (1 excised) and small bowel
obstruction in 1 (saved). 16 pouches were eventually excised or permanently
defunctioned (59%). CONCLUSION: Complications necessitating a later defunctioning
stoma after pouch construction carry a poor prognosis, especially when used for
ileoanal stenosis and fistulae.
PMID- 10781979
TI - Three-year evaluation of a rapid-access coloproctology clinic.
AB - BACKGROUND/AIMS: Evolving surgical practice has placed increasing pressures on
surgical outpatient clinics. This article provides a prospective evaluation of a
rapid-access coloproctology clinic over a 3-year period. METHODS: Primary care
physicians (PCP) were circulated details of the clinic, and invited to refer any
patient presenting with colorectal or anorectal symptoms, or with a family
history of bowel cancer wishing advice about screening. Data were collected
prospectively and patients and the referring PCPs were invited to complete a self
administered structured questionnaire. RESULTS: In all, 3,119 patients were
referred, the main indications being rectal bleeding (67%), abdominal pain (16%)
and change in bowel habit (15%). The average time interval between PCP visit and
specialist consultation was 2 days and neoplastic disease was detected in 7.1% of
patients. 70% of patients with haemorrhoids and 39% of those with other minor
diseases were discharged back to their PCPs after definitive treatment at the
time of their visit to the clinic. The majority of PCPs and patients expressed
satisfaction with the service as evidenced by the returned questionnaires.
CONCLUSION: These data show that a more universal implementation of such clinics
may result in improved care of colorectal disease and considerable savings of
outpatient time and resources.
PMID- 10781980
TI - Effects of perioperative treatment with TNP-470 on the resistance of colonic
anastomoses in rats.
AB - AIMS: The present study was designed to evaluate the effects of perioperative
treatment with TNP-470 on the resistance of colonic anastomoses. TNP-470 is a
drug that was developed as an inhibitor of angiogenesis. METHODS: A colonic
anastomosis was constructed in Sprague-Dawley rats. From 4 days before surgery to
4 days afterwards, each animal received daily intraperitoneal treatment that
differed according to the group to which it belonged: the control group, which
received gum arabic, or the TNP group, which received 30 mg/kg TNP-470 in gum
arabic. The size of the cecum and the diameters of the pre-anastomotic and post
anastomotic colon were measured at operation and 4 days after surgery, when all
animals were sacrificed. At this time the presence of adhesions was also
investigated. Each segment containing an anastomosis was removed and the bursting
pressure (BP) and bursting wall tension (BWT) were determined. RESULTS: Loss of
cecum caliber and decreases in pre-anastomotic diameter were significantly
greater in the TNP group than in the control group (p = 0.017 and p = 0.004,
respectively). Dilatation and obstruction of the colon were more frequent in the
control group, but the difference between the groups was significant only with
respect to dilatation (p = 0.005). Moreover, loss of body weight was greater in
the TNP group than in the control group (p < 0.001). BP and BWT were
significantly lower in animals that had received TNP-470 (p = 0.04 and p = 0.005,
respectively). With respect to post-anastomotic diameter, general adhesions and
adhesions to the anastomotic line, there were no statistically significant
differences between the groups. CONCLUSIONS: Perioperative treatment with TNP
470, an inhibitor of angiogenesis, affects the healing and reduces the resistance
of colonic anastomoses.
PMID- 10781981
TI - Acute abdomen and Clostridium difficile colitis: still a lethal combination.
AB - BACKGROUND: With the steadily prevalent appropriate and inappropriate use of
antimicrobial agents, Clostridium difficile colitis has continued to be noticed
as a common problem in hospitalized patients. The aim of this communication is to
highlight a subset of C. difficile colitis patients who presented with an acute
abdomen. METHODS: This is a retrospective study of 10 patients who underwent
laparotomy for an 'acute abdomen' with an intraoperative or postoperative
diagnosis of C. difficile colitis. RESULTS: All patients received antibiotics
(mean 9.5 days) for other illnesses. The mean APACHE II score was 18.8 (range 8
25) and the mortality rate was 80%. Two patients had colostomies created. One
patient underwent a subtotal colectomy, and another underwent a Hartmann
procedure; the rest had a nontherapeutic procedure. CONCLUSION: We conclude that
C. difficile colitis presenting as an 'acute abdomen' still represents a lethal
entity. Patients who present with an 'acute abdomen', with a history of recent or
current antibiotic intake, and without findings which mandate an exploration
should have C. difficile colitis urgently excluded. Timely diagnosis of C.
difficile colitis through bedside sigmoidoscopy or a CT scan could spare the
critically ill patient an unneccessary and risky operation. Furthermore, if
laparotomy is subsequently needed then having a preoperative diagnosis of C.
difficile colitis will allow appropriate surgical therapy to be implemented.
PMID- 10781983
TI - A case of trans-omental hernia: an incarcerated bowel condition detected by
computed tomography.
PMID- 10781982
TI - Cost-effectiveness study of imipenem/cilastatin versus meropenem in intra
abdominal infections.
AB - BACKGROUND: The efficacy of two carbapenems, imipenem/cilastatin (I/C, 1.5 g
daily) versus meropenem (3 g daily) in intra-abdominal infections was assessed in
a recent multicenter randomized clinical trial. The aim of this article is to
perform a cost-effectiveness analysis as in real-world practice according to the
findings of this clinical trial. METHODS: A decision tree was used to estimate
the clinical outcomes and direct costs of treating intra-abdominal infections
using the two carbapenems from the perspective of the Italian National Health
Service (INHS) or a private insurance company (PIC). RESULTS: In a population of
30,000 patients with intra-abdominal infections in Italy, it was estimated that
97 potential deaths/year could be avoided if these patients were treated with I/C
versus meropenem. In addition, from the perspective of INHS, the total costs of
treatment were estimated as ITL 106,874 million and 134,042 million for I/C and
meropenem, respectively. In favor of the PIC point of view, the total costs were
estimated as ITL 110,500 million and 135,899 million for I/C and meropenem,
respectively. CONCLUSION: The treatment of intra-abdominal infections with I/C is
shown to be more effective (97 deaths avoided/year) and less costly than with
meropenem (with a saving of ITL 27,168 and 25,399 million/year for INHS and PIC,
respectively).
PMID- 10781985
TI - Safe laparoscopic cholecystectomy in the presence of a cholecysto-enteric
fistula.
PMID- 10781984
TI - Gallstone disease masking malignant bile duct tumors: a rare but important
coincidence.
PMID- 10781986
TI - Spontaneous spleen rupture after bacterial endocarditis.
PMID- 10781987
TI - Splenic autotransplantation in Gaucher's disease.
PMID- 10781988
TI - Tuberculosis of the pancreas presenting as metastatic pancreatic carcinoma. A
case report and review of the literature.
PMID- 10781989
TI - Hydatid cyst of the pancreas.
AB - A rare case of hydatid cyst of the pancreas is reported. Although ultrasonography
and computerised tomography scan confirmed the presence of a cystic mass in the
body and tail of the pancreas, diagnosis was made only on laparotomy. A distal
pancreatectomy was done and the diagnosis of hydatid cyst of the pancreas was
confirmed by histopathology. Though very rare, pancreatic hydatidosis should be
considered in the differential diagnosis of cystic lesions of the pancreas in the
appropriate epidemiological setting.
PMID- 10781990
TI - Hyperintense basal ganglia on T1-weighted magnetic resonance images following
postoperative parenteral nutrition in a pancreatoduodenectomized patient.
AB - The authors reported the magnetic resonance imaging (MRI) detection of manganese
(Mn) deposition in the basal ganglia of a pancreatoduodenectomized patient
following 30-day parenteral nutrition. A multi-trace element supplement solution
including 20 micromol Mn/day was parenterally administered for 30 days
postoperatively. The serum level of total bilirubin normalized on the 3rd
postoperative day, while the level of alkaline phosphatase continued to exceed
the higher limit of normal controls even 2 months after operation. T1-weighted
MRI on the 49th postoperative day demonstrated bilateral and symmetrical
hyperintense lesions in the globus pallidus. The whole-blood Mn level on the 67th
postoperative day was 3.1 (normal range 0.8-2.5) microg/l. T1-weighted MRI on the
103rd postoperative day revealed improvement in the hyperintense lesions, and MRI
on the 225th postoperative day revealed no abnormality. The blood Mn level
normalized on the 194th postoperative day. Even short-term postoperative
parenteral nutrition may result in Mn deposition in the brain, especially in
patients with cholestasis following pancreatoduodenectomy.
PMID- 10781991
TI - Anorectal avulsion: an unusual rectal injury.
AB - Traumatic injuries to the rectum although uncommon can result in virulent
complications and even death. Diverting colostomy, presacral drainage, distal
wash out and rectal repair, when feasible, have become the standard treatment for
rectal injuries. We report an unusual case of rectal injury resulting in
anorectal avulsion from skin and surrounding tissues.
PMID- 10781992
TI - Malignant melanoma of the anorectal area. Report of two cases.
AB - BACKGROUND/AIMS: Primary anorectal melanoma is a very rare malignant tumor with
no more than 300 cases reported in the literature. METHODS: Two cases of
anorectal melanoma are reported herein. RESULTS: Both patients, aged 44 and 74
years, presented at the outpatient department with anal bleeding, one after being
treated for 3 months with antihemorrhoidal drugs. The diagnosis was established
with proctoscopy and biopsy, and a palliative abdominoperineal resection in the
presence of lymph node metastases was performed followed by chemotherapy with
vindesine. Although the procedures were not curative, both patients had an
uneventful postoperative recovery, and lived 4 years and 21 months, respectively,
without bleeding problems albeit with the inconvenience of a colostomy.
CONCLUSIONS: For the time being there is no convincing proof of the value of
either types of proposed surgical management. We agree with those who believe
that abdominal perineal resection has an advantage regarding the prognosis and
quality of life.
PMID- 10781993
TI - Fecal impaction causing megarectum-producing colorectal catastrophes. A report of
two cases.
AB - PURPOSE: Massive fecal impaction leading to surgical catastrophes has rarely been
reported. We present 2 such patients to remind physicians that neglected
accumulation of fecal matter in the rectum may lead to ischemia and perforation
of the colon and rectum. METHODS: Report of 2 patients and a MEDLINE search of
the literature. RESULTS: In the 1st case massive fecal impaction produced an
abdominal compartment syndrome and rectal necrosis. In the 2nd patient fecal
impaction resulted in colonic obstruction and ischemia. In both, an operation was
life-saving. CONCLUSION: Neglected fecal impaction may lead to a megarectum
causing an abdominal compartment syndrome and colorectal obstruction, perforation
or necrosis. Measures to prevent fecal impaction are of paramount importance and
prompt manual disimpaction before the above complications develop is mandatory.
Appropriate operative treatment may be life-saving.
PMID- 10781994
TI - Continuous monitoring of fetal pH, pO(2) and pCO(2) using a fiberoptic
multiparameter sensor in animal models reproducing in utero conditions.
AB - OBJECTIVES: To evaluate the feasibility and accuracy of continuous fetal
monitoring with a multiparameter intravascular sensor (MPIS) in animal models
mimicking the fetal metabolic status. METHODS: First, the accuracy of the MPIS in
hypoxic conditions was tested in adult rabbits (n = 6). The carotid artery (n =
4) or vein (n = 2) was catheterized with a 20-gauge cannula, housing a 500-microm
Neotrend((R)) fiberoptic sensor for pCO(2), pO(2), pH and temperature. Fiberoptic
readings were compared with arterial blood-gas (ABG) analyses. Secondly, the
feasibility of continuous fetal fiberoptic sensing was tested during experimental
fetoscopic surgery in lambs (n = 4). An identical sensor was introduced in a
chorionic artery and readings were compared to ABG analyses of fetal blood
samples. RESULTS: The overall bias and precision in the first experiment (147
measurement pairs) were -4.2 and 10.9 mm Hg for pO(2), +1.6 and 8.2 mm Hg for
pCO(2) and -0.015 and 0.031 for pH, respectively. In the sheep experiments,
continuous readings for all parameters were only available during 50% of the
operation time, mainly due to disturbances induced by movement, contact with
vessel wall and interference by endoscopic light. 20 sample pairs were obtained
resulting in an overall bias and precision of -3.9 and 4.3 mm Hg for pO(2), -0.74
and 3.68 mm Hg for pCO(2) and -0.0032 and 0. 02 for pH. CONCLUSIONS: Fiberoptic
microsensors are potentially useful for monitoring acid-base status in the low
pO(2) range present in fetal life.
PMID- 10781995
TI - B19 parvovirus-induced fetal hydrops:good outcome after intrauterine blood
transfusion at 18 weeks of gestation.
AB - We report a successful treatment of a B19 parvovirus-induced fetal hydrops
diagnosed at 16 weeks of gestation. This disease could be corrected by means of a
unique intraperitoneal blood transfusion performed at 18 weeks, once diagnosis
was established. The delivery occurred at 36 weeks, leading to the birth of a
healthy baby. This case suggests that transfusion should be attempted, as the
spontaneous fetal recovery remains uncertain and shows that intraperitoneal blood
transfusion is an effective therapeutic option of the B19 parvovirus-induced
anemia, in the absence of a viral myocarditis.
PMID- 10781997
TI - Contrast-enhanced ultrasonography of uteroplacental circulation does not evoke
harmful CTG changes or perinatal events.
AB - OBJECTIVE: To determine whether an intravascular ultrasound contrast agent used
in the examination of uteroplacental circulation in late pregnancy has any effect
on fetal cardiotocographic (CTG) parameters or fetal well-being. METHODS: The
uteroplacental circulation of 69 women with singleton third trimester pregnancies
was examined by power Doppler with contrast agent (Levovist((R)); Schering AG,
Berlin, Germany) enhancement. Computed CTG examination using Dawes/Redman
criteria was recorded just before and after ultrasonographic examination in 25
subjects examined with contrast agent and in 15 control patients who were given
only physiological saline injection during ultrasonography. Umbilical artery
blood flow velocity waveform was examined in 15 subjects before and 5 min after
maternal contrast agent injection. Obstetric outcome of all the 69 subjects was
evaluated by birthweight, placental weight, fetal and neonatal distress, prenatal
hemorrhages, cord arterial and venous blood pH and macroscopic placental
examination. RESULTS: No apparent fetal or maternal harmful effects caused by the
contrast-enhanced ultrasonography were observed. In CTG examination there was a
statistically significant increase in the number of accelerations and fetal
movements and in short-term variation after administration of the contrast agent
in both subjects and controls. There were no significant changes in the umbilical
artery blood flow velocity waveform after administration of the contrast agent.
CONCLUSIONS: Contrast agent enhancement in the examination of uteroplacental
circulation does not produce any harmful fetal or placental effects in late
pregnancy. Ultrasonographic examination itself, obviously due to maternal stress
reaction, is associated with a slight activation of fetal behavioral status.
PMID- 10781996
TI - Hepatic mesenchymal hamartoma associated with mesenchymal stem villous
hyperplasia of the placenta.
AB - A rare case of prenatally diagnosed hepatic mesenchymal hamartoma associated with
mesenchymal stem villous hyperplasia of the placenta is presented and the
literature reviewed. The placenta was noticed to have multiple cysts at 16 weeks'
gestation and elevated maternal serum alpha-fetoprotein was present. Cystic liver
masses were first detected in the fetus at 34 weeks' gestation. The liver mass
showed a progressive enlargement during the third trimester and after birth,
necessitating extended left hepatic trisegmentectomy at 3 months of age.
Histological examination established the diagnosis of mesenchymal hamartoma of
the liver and mesenchymal stem villous hyperplasia of the placenta. This is the
first report of this association in which both lesions were diagnosed in utero
and confirmed by histology after delivery. The likely pathogenesis of these
strikingly similar lesions is discussed.
PMID- 10781998
TI - Prenatal diagnosis and elective termination of neural tube defects in Hawaii,
1986-1997.
AB - OBJECTIVE: To determine the influence of various factors on the prenatal
diagnosis and elective termination of neural tube defects (NTDs) in Hawaii in
1986-1997. METHODS: Data from a birth defects registry were analyzed and included
245 cases. RESULTS: 74% of the cases were prenatally diagnosed and 48% were
terminated. Anencephaly was more likely to be prenatally diagnosed and electively
terminated than spina bifida or encephalocele. Other factors such as maternal
age, race/ethnicity, place of residence, and elevated maternal serum alpha
fetoprotein influenced the prenatal diagnosis and/or elective termination of NTD
affected pregnancies. However, a given factor may influence prenatal diagnosis
and elective termination in different ways. CONCLUSIONS: Various diagnostic and
demographic factors can influence the prenatal diagnosis and the subsequent
termination of NTD-affected pregnancies.
PMID- 10781999
TI - In utero diagnosis of trichothiodystrophy by endoscopically-guided fetal eyebrow
biopsy.
AB - OBJECTIVE: To describe the prenatal diagnosis of trichothiodystrophy (TTD)
through endoscopically-guided fetal eyebrow biopsy. MATERIALS AND METHODS: A 32
year-old patient, gravida 4, para 3, with a history of 2 previous infants
affected with TTD was referred at 17(5)/(7) weeks for fetal hair biopsy. DNA
repair studies had been normal in the previous children. Four 1-mm biopsies were
obtained from the external aspect of the fetal eyebrows under direct endoscopic
guidance. Fetal hair samples were assessed with polarized microscopy, electron
microscopy, hematoxylin and eosin staining, and were also sent for analysis of
sulfur content (cystine levels). RESULTS: The fetal eyebrows were the only
adequate source of hair in the early second trimester. The biopsy samples yielded
adequate material for all tests. Polarized microscopy showed characteristic
banding patterns, but trichoschisis was not apparent. Cystine levels (19
micromol/l) in the biopsy sample were significantly lower than an age-matched
(fresh spontaneous abortion) control (368 micromol/l). CONCLUSION: Prenatal
diagnosis of TTD is possible in the second trimester through endoscopically
guided eyebrow biopsy. An adequate amount of hair is present in the eyebrows by
then, and the disease is already manifest. Analysis of sulfur content of the hair
samples is preferred over polarized or electron microscopy, as many classic
microscopic findings of TTD may not be present in the early second trimester.
PMID- 10782001
TI - Correlation of Doppler velocimetry findings in twin pregnancies including course
of pregnancy and fetal outcome.
AB - OBJECTIVE: Subject of the study was the significance of umbilical artery Doppler
velocimetry findings for the further course of pregnancy and fetal outcome in
cases of twin pregnancies. METHODS: In 206 cases of twin pregnancy, the umbilical
artery was examined using Doppler velocimetry in the median 9 days prior to
delivery, and the result was correlated with the further course of pregnancy and
fetal outcome. 174 pregnancies showed normal Doppler findings of the umbilical
artery (group A), 32 twin pregnancies showed pathological Doppler findings of at
least one twin (group B). The median of the maternal age and the parity between
the groups were not different. RESULTS: In group B (pathological Doppler
findings), intrauterine growth retardation and pre-eclampsia occurred 5 times
more often than in group A (normal Doppler findings). The total rate of cesarean
sections was not different between the study populations; the rate of deliveries
by cesarean section in group B was significantly increased by a factor of 2.4 due
to a pathological CTG. The median birth weight and the gestational age at birth
were significantly lower in group B (1,660 g; 35 weeks) as compared to group A
(2,460 g; 37 weeks; p<0.001). In group B, the rate of premature deliveries up to
reaching the 34th week of gestation was 3. 4 times higher; the rate of SGA
newborns was 6.3 times higher. Perinatal mortality was increased by a factor of
1.5 in group B compared to group A. CONCLUSION: The Doppler velocimetry findings
have considerable effects on the further course of a multiple pregnancy. In case
of pathological Doppler findings, early hospitalization and close monitoring of
the pregnancy should be performed. In cases of additional pathological findings
(maternal illness, pathological Doppler findings of fetal blood vessels),
termination of the pregnancy has to be considered.
PMID- 10782000
TI - Detection of skin over cysts with Spina bifida may be useful not only for
preventing neurological damage during labor but also for predicting fetal
prognosis.
AB - Spina bifida is one of the most common open neural tube defects. There are two
common types of spina bifida cystica, myelomeningocele and meningocele. Special
attention to the thickness of the cystic sac (presence of intact skin and
subcutaneous tissue) on magnetic resonance imaging is advantageous for
determination of whether the child will profit from cesarean section in order to
prevent neurological change (infection and drying of nerve tissue) and for
management of spina bifida (most meningocele) during the perinatal period.
Furthermore, skin detection may help to predict the prognosis of spina bifida
after birth. Meningocele, with intact skin over the cyst, has a better clinical
course than myelomeningocele. Some myelomeningoceles with neural tube defects in
a lower position, also frequently having an intact skin over the cyst, have
almost the same clinical course as a meningocele. From this, we hypothesize that
a baby with spina bifida who has intact skin over the cyst might have a good
prognosis neurologically. In this report, we concentrate attention on the skin
over cysts in 3 cases (1 meningocele and 2 myelomeningoceles).
PMID- 10782002
TI - Nucleated red blood cells in growth-restricted fetuses: associations with short
term neonatal outcome.
AB - OBJECTIVE: To determine the utility of the neonatal nucleated red blood cell
(NRBC) count as an independent predictor of short-term perinatal outcome in
growth-restricted fetuses. METHODS: Hospital charts of neonates with a discharge
diagnosis indicating a birth weight <10th percentile were reviewed for perinatal
outcome. We studied all eligible neonates who had a complete blood count on the
first day of life. After multiple gestations, anomalous fetuses and diabetic
pregnancies were excluded; 73 neonates comprised the study group. Statistical
analysis included ANOVA, simple and stepwise regression. RESULTS: Elevated NRBC
counts were significantly associated with cesarean section for non-reassuring
fetal status, neonatal intensive care unit admission and duration of neonatal
intensive care unit stay, respiratory distress and intubation, thrombocytopenia,
hyperbilirubinemia, intraventricular hemorrhage and neonatal death. Stepwise
regression analysis including gestational age at birth, birth weight and NRBC
count demonstrated that in growth-restricted fetuses, NRBC count was the
strongest predictor of neonatal intraventricular hemorrhage, neonatal respiratory
distress and neonatal death. CONCLUSION: An elevated NRBC count independently
predicts adverse perinatal outcome in growth-restricted fetuses.
PMID- 10782003
TI - Assessment of risk for chromosomal abnormalities at 10-14 weeks of gestation by
nuchal translucency and maternal age in 5,210 fetuses at a single centre.
AB - OBJECTIVE: To evaluate the screening of chromosomal abnormalities by nuchal
translucency (NT) measurement. METHODS: Assessment of risk for chromosomal
abnormalities by NT and maternal age in 5,210 single fetuses with karyotype and
outcome already known. RESULTS: Risk was > or =1 in 300 in 640 (12.2%) of all
fetuses, in 575 (11.1%) of the normal fetuses, in 38 (80.8%) of the fetuses
affected by trisomy 21, and in 65 (89%) of the fetuses affected by chromosomal
abnormalities. Risk was > or =1 in 200 in 477 (9.1%) of all fetuses, in 418
(8.1%) of the normal fetuses, in 35 (74.4%) of the fetuses affected by trisomy
21, and in 59 (80.8%) of the fetuses affected by chromosomal abnormalities. Risk
was > or =1 in 100 in 270 (5.1%) of all fetuses, in 216 (4.2%) of the normal
fetuses, in 33 (70.2%) of the fetuses affected by trisomy 21, and in 54 (73.9%)
of the fetuses affected by chromosomal abnormalities. CONCLUSIONS: Risk generated
by NT and maternal age is effective in screening for chromosomal abnormalities.
PMID- 10782004
TI - Multiple cardiac rhabdomyomas detected in utero.
AB - Prenatal fetal echocardiography studies detected large multiple cardiac
rhabdomyomas and led to the diagnosis of tuberous sclerosis. Despite episodes of
bradyarrhythmias and severe lung compression in utero, the neonate did well and
was discharged home on day 20 of life. On day 30 of life, the infant expired at
home from cardiac arrest secondary to arrhythmia.
PMID- 10782005
TI - Cord ultrasonic transection procedure for selective termination of a
monochorionic twin.
AB - Placental vascular communications can present a life-threatening problem in
monochorionic twins when one fetus has a lethal anomaly. Although selective
feticide is the best option for salvaging the normal twin, techniques normally
employed (i.e. intracardiac potassium, air embolism) are not prudent given the
common circulatory system. Furthermore, in monoamniotic, monochorionic twin
gestations it is important to transect the umbilical cord completely to prevent
entanglement of the dead fetus around the cord of the normal twin. We present two
cases of monochorionic twins in which the cords were transected with a harmonic
scalpel under ultrasonic guidance via one trocar. The harmonic scalpel is an
instrument which can simultaneously coagulate and cut blood vessels or tissues.
The cord ultrasonic transection procedure is a novel, minimally invasive
technique which offers several advantages over the methods currently used for
selective feticide in discordant monochorionic twin gestations.
PMID- 10782006
TI - Predictive factors of fetal urethral obstruction: a multivariate analysis.
AB - OBJECTIVE: The purpose of this study was to identify predictive factors of fetal
urethral obstruction. METHODS: One hundred and forty-eight children with fetal
hydronephrosis were admitted, submitted to a systematic protocol and
prospectively followed. Possible predictive factors of urethral obstruction
associated with fetal echography and clinical findings on admission were studied.
The analysis was conducted in two steps. In a univariate analysis, variables
associated with urethral obstruction were identified by the chi(2) test or by
Fisher's exact test. Then, the variables that were significantly associated with
urethral obstruction were included in a multiple logistic regression analysis.
RESULTS: After final adjustment by multiple logistic regression analysis, only
two variables were identified as independent predictors of fetal urethral
obstruction: oligohydramnios (odds ratio, OR = 5, 95% confidence interval, CI, =
1.3-15, p = 0.01) and megacystis (OR = 9, 95% CI = 2.0-40, p = 0.004). The
sensitivity and specificity of the combination of both variables were 60 and
98.5%, respectively. CONCLUSIONS: The presence of oligohydramnios and megacystis
on prenatal ultrasound is highly predictive of fetal urethral obstruction.
PMID- 10782007
TI - In utero repair of rectal atresia after complete resection of a sacrococcygeal
teratoma.
AB - PURPOSE: A case of a fetus with a prenatally diagnosed sacrococcygeal teratoma
that produced high-output cardiac failure, hydrops, rectal atresia, and urinary
tract obstruction is presented. The unique prenatal surgical management along
with the embryogenesis of tumor-related rectal atresia is discussed. CASE REPORT:
A large fetal sacrococcygeal teratoma with a significant intrapelvic component
was detected at routine ultrasound in a 35-year-old gravida 3 para 2. Fetal
hydrops developed rapidly due to high-output cardiac failure from the vascular
'steal' by the growing tumor. The urinary tract was obstructed due to the
intrapelvic tumors mass. At 27 weeks' gestation, the female fetus underwent
hysterotomy, resection of the entire mass and urinary diversion via bilateral
flank ureterostomies. The rectum was found to be completely atretic due to
apparent encasement by the tumor. Pull-through anorectoplasty was carried out
concurrently. At 30 weeks' gestation, the mother developed preterm labor and a
1.8-kg was delivered by cesarean section. The baby did very well for 3 days but
had a cardiac arrest and died due to an atrial perforation by a transfemoral
venous catheter. CONCLUSIONS: To our knowledge this is the first report of a
complete prenatal resection of a sacrococcygeal teratoma with concomitant pull
through anorectoplasty for rectal atresia.
PMID- 10782008
TI - [Reduction of stuttering frequency using frequency-shifted and delayed auditory
feedback].
AB - In 12 stuttering subjects the fluency enhancing effect of delayed auditory
feedback (DAF) and frequency-shifted auditory feedback (FAF) was compared. The
subjects had to read three passages consisting of 300 syllables under
simultaneous auditory feedback, DAF (delay time: 53 ms) and FAF (frequency shift:
-(1/2) octave). Stuttering frequency and percentage of discontinuous speech time
were determined. Only under DAF a fluency enhancing effect in the mean values was
observed, but not under FAF. However, in 4 subjects a reduction in stuttering
frequency of 50% occurred. The conclusion is drawn that the use of FAF as a
prosthetic device is limited. The relationship between prolonged speech and
fluency enhancing is discussed.
PMID- 10782009
TI - Prevalence and characteristics of dysarthria in a multiple-sclerosis incidence
cohort: relation to neurological data.
AB - Few attempts have been made to use degree and type of multiple sclerosis (MS)
dysarthria in neurological evaluation. In the present study, 77 individuals drawn
from an MS population were examined both by a speech pathologist and a
neurologist, and data from three sources of information were subsequently
combined: (1) a clinical dysarthria test procedure, (2) a perceptual analysis of
speech characteristics in continuous speech, and (3) neurological deficit
scoring. The speech of 15 age- and gender-matched healthy control subjects was
also investigated. It was concluded that: (1) the prevalence of mild to severe
dysarthria in this cohort was 51% and occurred in all components of speech
production: respiration, phonation, prosody, articulation and nasality. (2) The
clinical dysarthria test was sensitive in detecting subclinical speech signs. The
prevalence of pathologic speech signs found on the basis of the test was found to
be 62%. The prevalence of dysarthria based on the neurological evaluation alone
was 20%. (3) The dysarthria of MS was a predominantly mixed dysarthria, with both
ataxic and spastic speech signs frequently present in the speech of a given
individual. (4) Furthermore, when a predominant type of dysarthria existed, it
was not generally associated with a characteristic profile of neurological
deficits. Rather, severity of speech deviation was positively correlated to
overall severity of neurological involvement, type of disease course, and number
of years in progression.
PMID- 10782010
TI - Evoked potentials and electroencephalography in stuttering.
AB - The study was aimed at finding what factors in evoked potentials and EEG related
to stuttering in subjects 6-25 years of age. Thirty-seven subjects who stuttered
and 25 nonstuttering subjects, matched for age, sex and education, were evaluated
employing visual evoked potentials, auditory evoked potentials, event-related
potentials (P(300)), WISC-(IQ), and electroencephalography. A significant
reduction of amplitude of P(100) of visual evoked potentials was found in
stutterers with a significant prolongation of wave latencies I, III, V and
interpeak latencies I-III and I-V in brainstem auditory evoked potentials. No
significant abnormalities were recorded in P(200), N(200) and P(300) of event
related potentials in stutterers compared with the control group. The dominant
EEG rhythm was slower in stutterers with a significant interhemispheric asymmetry
compared with the control group. Fifty-four percent of the stutterers had
pathological EEG. Epileptiform activities were recorded in 16.2% of stuttering
subjects. Focal left temporal spike activity was recorded in 5.4% of stuttering
subjects. The findings of this study point to a possible role of an organic
etiopathogenesis of stuttering.
PMID- 10782011
TI - Speech disorders following severe traumatic brain injury: kinematic analysis of
syllable repetitions using electromagnetic articulography.
AB - Using electromagnetic articulography, the lips, the tip of the tongue, and the
tongue dorsum were tracked during repetitions of the syllables [pa], [ta] and
[ka] in 10 speakers with dysarthria following severe traumatic brain injury and
in 10 age-matched control subjects. When asked to produce the syllable trains as
fast as possible, the patient group showed a rather homogeneous pattern of
movement abnormalities including prolonged syllable durations and reduced peak
velocity/amplitude ratios. Most presumably, limited speed generation gives rise
to the impaired ability to increase speech rate. During the habitual speaking
condition, reduced velocity/amplitude ratios were restricted to the tongue tip
and tongue dorsum. Obviously, the tongue and the lips are differentially affected
in dysarthria following severe traumatic brain injury.
PMID- 10782012
TI - A unified approach to adjusting association tests for population admixture with
arbitrary pedigree structure and arbitrary missing marker information.
AB - A general approach to family-based examinations of association between marker
alleles and traits is proposed. The approach is based on computing p values by
comparing test statistics for association to their conditional distributions
given the minimal sufficient statistic under the null hypothesis for the genetic
model, sampling plan and population admixture. The approach can be applied with
any test statistic, so any kind of phenotype and multi-allelic markers may be
examined, and covariates may be included in analyses. By virtue of the
conditioning, the approach results in correct type I error probabilities
regardless of population admixture, the true genetic model and the sampling
strategy. An algorithm for computing the conditional distributions is described,
and the results of the algorithm for configurations of nuclear families are
presented. The algorithm is applicable with all pedigree structures and all
patterns of missing marker allele information.
PMID- 10782013
TI - Apolipoprotein B 3'-VNTR polymorphism in the Udmurt population.
AB - An analysis of a highly polymorphic region of the apolipoprotein B gene 3'-end
DNA (Apo B 3'-VNTR), represented by 10 alleles, was carried out using the
polymerase chain reaction. Data inferred from the principal component analysis
indicate that the Udmurts occupy an isolated position among the populations
constituting the northern branch of Caucasoid peoples.
PMID- 10782014
TI - Adjusting for confounding due to population admixture when estimating the effect
of candidate genes on quantitative traits.
AB - When analyzing the relationship between allelic variability and traits, a
potential source of confounding is population admixture. An approach to adjusting
for potential confounding due to population admixture when estimating the
influence of allelic variability at a candidate gene is presented. The approach
involves augmenting linear regression models with additional regressors. Family
genotype data are used to define the regressors, and inclusion of the regressors
ensures that, even in the presence of population admixture, the estimates of the
regression coefficients that parameterize the influence of allelic variability on
the trait are unbiased. The approach is illustrated through an analysis of the
influence of apolipoprotein E genotype on plasma low density lipoprotein
cholesterol concentrations.
PMID- 10782015
TI - K5 D328E: a novel missense mutation in the linker 12 domain of keratin 5
associated with epidermolysis bullosa simplex (Weber-Cockayne).
AB - A novel missense mutation was detected in the L12 region of keratin 5 (K5) in a
Slovene family diagnosed with a Weber-Cockayne variant of epidermolysis bullosa
simplex (EBS). Direct sequencing identified a heterozygous GAC to GAA
substitution altering codon 328 of K5 from Asp to Glu in all affected family
members, while no mutation was observed either in the healthy individual or the
50 unrelated control samples. Asp(328) of K5 (position 12 in the L12 domain) is
remarkably conserved among all type II keratins. K5 L12:D12E is the third
mutation found to affect this residue in K5-related EBS, indicating the
importance of Asp(328) for K5 structure and the dramatic effect that fine changes
can have on keratin intermediate filament integrity.
PMID- 10782016
TI - Molecular heterogeneity of the glucose-6-phosphate dehydrogenase deficiency in
the Hellenic population.
AB - We report results from a systematic study to identify the molecular basis of
glucose-6-phosphate dehydrogenase (G6PD) deficiency on a sample of 299 male
subjects from the Hellenic population. Our stepwise approach involved partial
biochemical characterization and quantitation of the enzyme's activity, MboII
restriction endonuclease digestion to identify the G6PD Mediterranean variant,
which represents the most frequent G6PD variant in our population and a
nonradioactive polymerase chain reaction-single-strand conformation polymorphism
methodology for the detection of the underlying molecular defect(s) in the rest
of the non-Mediterranean G6PD-deficient individuals. Through this approach, six
different G6PD variants were identified (G6PD Mediterranean, G6PD Hermoupolis,
G6PD Cassano, G6PD Seattle, G6PD Ierapetra and G6PD Acrokorinthos), two of which
were new (G6PD Hermoupolis, G6PD Acrokorinthos). In essence, this study
underlines the remarkable genetic heterogeneity of the G6PD deficiency in the
Hellenic population, while the finding of the double mutant, G6PD Hermoupolis,
may help to outline the relationship and evolution of mutations in the human G6PD
locus.
PMID- 10782017
TI - High frequency of HLA-DQB1 non-Asp(57) alleles in Kuwaiti children with insulin
dependent diabetes mellitus.
AB - The prevalence of polymorphic amino acids at position 57 of the HLA DQB1 in
Kuwaiti children with insulin-dependent diabetes mellitus (IDDM) and nondiabetic
controls has been determined using a polymerase chain reaction-sequence-specific
primers (PCR-SSP) method. Using this approach, 34/55 (62%) IDDM children were
found to be homozygous Ala/Ala and 19/55 (35%) were heterozygous with various
combinations. Amongst the IDDM children with heterozygous genotype at codon 57 of
HLA DQB1, 6/55 (11%) had Asp/Ala, 8/55 (15%) had Ala/Val, 4/55 (7%) had Ala/Ser
and 1/55 had Asp/Val allelic combinations. When considered collectively, the
nonaspartate (NA) alleles were represented in 87% of the IDDM cases and only 13%
cases had Asp(57) allele in different heterozygous combinations, while none of
the IDDM subjects had a homozygous Asp genotype. In nondiabetic controls,
homozygous non-Asp (NA) alleles were represented in 44% subjects, 37% of the
controls were heterozygous (NA/A) and 19% had a homozygous (A/A) genotype. These
differences between the IDDM group and the control group were found to be
statistically significant. Our data report one of the highest frequency of NA/NA
residues at this locus compared with that from different world populations
(Sardinians, Norwegians, US Caucasians, US Blacks and Chinese).
PMID- 10782018
TI - Identification of a prevalent nonsense mutation (W283X) and two novel mutations
in the porphobilinogen deaminase gene of Swiss patients with acute intermittent
porphyria.
AB - Acute intermittent porphyria (AIP) is an autosomal dominant disorder caused by
decreased activity of porphobilinogen deaminase (PBGD), the third enzyme in the
heme biosynthetic pathway. We report the first molecular analysis of PBGD gene
mutations in AIP patients of Swiss origin. The PBGD gene of 18 Swiss AIP patients
was analyzed by denaturing gradient gel electrophoresis screening of the genomic
DNA and direct sequencing. Thirteen of the 18 patients (72%) carried a nonsense
mutation G(849)-->A, W283X. In addition, 4 different mutations including 2 novel
mutations (Q217L and Q292X), were identified in the 5 remaining AIP patients
originating from both German- and Italian-speaking regions of Switzerland.
PMID- 10782019
TI - Linkage analysis of quantitative trait loci: sib pairs or sibships?
AB - Sib pair linkage studies are now widely used to investigate the genetic factors
implicated in complex quantitative traits. To increase the power of these
approaches, it has been proposed to select extremely discordant (ED) sib pairs
which are expected to contain the highest linkage information. However, it is
known that sibships of larger size contain more linkage information than
independent sib pairs. In this paper we compare, in terms of power and cost
considerations, the ED strategy, which uses information on sib pairs only, to the
recently developed 'Maximum Likelihood Binomial' sibship-oriented method
performed on the whole sibships from which the ED sib pairs have been extracted.
We show that the use of these whole sibships is an efficient alternative to
approaches focusing on ED sib pairs only.
PMID- 10782020
TI - A study on the degree of relationship between two individuals.
AB - The paper studies the likely degree of relationship between two individuals who
could possibly be half sibs. The possible common ancestor was dead, which further
complicated the problem. The model used was devised by Thompson [in Rao and
Chakraborty (eds): Handbook of Statistics, North-Holland, Amsterdam, 1991] and
establishes a correspondence between the possible degree of relationship and
certain feasible probability distributions on the number of identical by descent
genes. Two statistical approaches are considered: the classical one, in which the
maximum likelihood estimation for the parameters of Thompson's model are
obtained, and the Bayesian one, in which the test of the hypothesis of half sibs
is accompanied by a robustness study.
PMID- 10782021
TI - Haptoglobin 1F allele frequency is high among indigenous populations in the state
of Durango, Mexico.
AB - We studied haptoglobin polymorphism in Mexican populations with high Indian
ancestry living in isolated and urban areas in the state of Durango. Analysis
with respect to the HP*1F and HP*1S allelic subtypes by isoelectric focusing
showed unusually high HP*1F allele frequencies among urban (0.370) and isolated
Mexican Indians (0.383). Comparison with other population studies demonstrated a
geographical cline of the HP*1F allele increasing in the same direction of the
HP*1 allele, while HP*1S frequency does not show racial differences.
PMID- 10782022
TI - A novel mutation (2409delT) in exon 14 of the factor VIII gene causes severe
haemophilia A.
PMID- 10782023
TI - The 677 C-->T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene in
five Chinese ethnic groups.
PMID- 10782024
TI - Five-year survival results of subcutaneous low-dose immunotherapy with
interleukin-2 alone in metastatic renal cell cancer patients.
AB - After the discovery of its essential role in anticancer immunity, IL-2 cancer
immunotherapy has shown that comparable results may be obtained with different
schedules, including intravenous high-dose IL-2 as a bolus or as a 24-hour
intravenous infusion or prolonged subcutaneous injection of low-dose IL-2 with or
without IFN-alpha. This study shows the long-term results obtained in 92
metastatic renal cell cancer (RCC) patients with low-dose subcutaneous IL-2,
which was given at 3 million IU twice/day for 5 days/week for 6 consecutive
weeks. In nonprogressing patients, a second cycle was planned after a 21-day rest
period, followed by maintenance therapy consisting of 5 days of treatment every
month until disease progression. Complete response (CR) was achieved in only 2/92
(2%) patients, and partial response (PR) was observed in 19 patients (21%).
Therefore, the response rate (CR + PR) was 21/92 (23%), with a median duration of
response of 25 months. Stable disease (SD) occurred in 37 patients (40%), whereas
the other 34 (37%) had a progressive disease (PD). The response rate was
significantly higher in patients with a disease-free interval of >1 year than in
those with a lower interval, in patients with a high performance status (PS) than
in those with a low PS, and in patients with sites of disease other than the
liver. A 5-year survival was obtained in 9/92 (9%) patients, and the percent of
survival was significantly higher in patients with a response or SD than in those
with PD. The treatment was well tolerated in all patients. This study confirms
that low-dose subcutaneous IL-2 alone in an effective and well tolerated therapy
of metastatic RCC, with results comparable to those described with more
aggressive and toxic IL-2 schedules.
PMID- 10782025
TI - Renal cell carcinoma in cases of adult polycystic kidney disease: changing
diagnostic and therapeutic implications.
AB - Renal cell carcinoma in adult polycystic kidney disease is of rare occurrence and
poses a diagnostic and therapeutic challenge. We have treated three such patients
in our department. One was male and two were females ranging in age from 20 to 60
years. All were diagnosed preoperatively with ultrasonography or contrast
enhanced CT. Radical nephrectomy was performed in all patients. During the follow
up no patient had recurrence in the contralateral kidney. One patient had local
recurrence in the renal fossa and was treated with local radiotherapy and
immunotherapy. In the past due to difficulty in diagnosis, invasive
investigations like angiography were recommended and prophylactic contralateral
nephrectomy was often undertaken. With the availability of reliable noninvasive
investigations these patients can be diagnosed accurately and the contralateral
kidney saved in most cases.
PMID- 10782026
TI - The correlation of p53 protein overexpression and p53 antibodies in serum of
patients with transitional cell carcinoma of the urinary bladder.
AB - BACKGROUND: Mutations of p53 gene were demonstrated in many solid tumors with
varying frequency. We analyzed the relationship between p53 protein expression in
bladder cancer tissue, p53 autoantibodies in serum and the clinical course of 32
patients with and 10 patients without transitional cell carcinoma of the urinary
bladder. MATERIALS AND METHODS: In the 32 patients studied, bladder cancer was
diagnosed as pTaG1-2 in 8 cases, pT1G2 in 6, pT1G3 in 7, pT2G2-3 in 7, pT3G2-3 in
3 and pT4 in 1 patient. Anti-p53 antibodies were detected by an enzyme-linked
immunosorbent assay. Immunohistochemical staining was performed using a
standardized alkaline phosphatase monoclonal anti-alkaline phosphatase method. To
prove the statistical significance of tumor grading and staging, the Kruskal
Wallis test was applied (p < 0.01). The mean follow-up was 26 months. RESULTS: We
found 12.5% p53 autoantibody-positive sera without a statistically significant
correlation with tumor grade (p = 0.0569) and category (p = 0.612). Three of 4
patients who had p53 autoantibody-positive sera died within 9 months. All of
these sera-positive patients had p53 protein-positive tumor tissue. Control sera
were all negative for p53 autoantibodies. CONCLUSION: This study shows a strong
relationship between p53 protein overexpression and the occurrence of p53
autoantibody in bladder cancer. The expression of p53 autoantibodies seems to be
an event in cases of bladder cancer with an unfavorable tumor-specific outcome.
Because of the small number of cases and the short follow-up time, further
quantitative studies will hopefully demonstrate whether this might be of
prognostic importance.
PMID- 10782027
TI - Value of free prostate-specific antigen (Hybritech Tandem-R) in symptomatic
patients consulting the urologist.
AB - INTRODUCTION: Prostate-specific antigen (PSA) is a widely used tumor marker in
the detection and follow-up of adenocarcinoma of the prostate. Selection of
candidates for prostate biopsies is hampered by the lack of specificity resulting
in a large number of unnecessary biopsies. The intention of our study was to
compare the percent free PSA (f-PSA; Hybritech Tandem-R) with total PSA and age
specific PSA reference values to evaluate the clinical benefit in detecting
patients with prostate cancer (PC) in a selected group of patients consulting the
urologist. The question was whether cutoff points are influenced by this
selection of patients. METHODS: A total of 188 patients, 114 with benign prostate
hyperplasia (BPH) and 74 with PC were selected. It is a selected group of
patients consulting the urologist. Diagnosis was confirmed in the BPH and PC
groups by either ultrasound-guided biopsy or transurethral resection of the
prostate or suprapubic adenomectomy or cystoprostatectomy. Total PSA (t-PSA) and
f-PSA of all patients were measured before any manipulation by Tandem-R assay for
f-PSA and Tandem-E assay for t-PSA (Hybritech). Mean values of age, prostate
volume, t-PSA, f-PSA, percent f-PSA were compared in patients with BPH and PC by
Mann-Whitney U test. The sensitivity and specificity of t-PSA and age-specific
PSA were compared to the sensitivities and specificities of different cutoff
points of percent f-PSA. RESULTS: The mean value of t-PSA, f-PSA and percent f
PSA in patients with BPH (n = 114) and PC (n = 74) were statistically
significantly different. At PSA levels between 4 and 10 ng/ml 19% of negative
biopsies could be avoided by the use of percent f-PSA (cutoff point 25%). There
was no additional benefit of age-specific PSA. At a PSA of <4 ng/ml 6 of 7 PCs
could be diagnosed by percent f-PSA (cutoff point 25%), whereas only 1 patient
would be diagnosed by age-specific PSA. CONCLUSION: Percent f-PSA seems to
decrease the biopsy rate at PSA levels from 4 to 10 ng/ml without missing a
relevant number of cancers and to increase the detection rate at PSA <4 ng/ml.
Our data indicate that it might be necessary to choose high cutoff points (25%;
Tandem-E and R assay, Hybritech) in a selected study population consulting the
urologist with large glands and a high prevalence of disease. However, this
situation is not comparable to testing of screening populations. No benefit of
age-specific PSA could be observed in this study.
PMID- 10782028
TI - Effect of transrectal ultrasonography of the prostate on serum prostate-specific
antigen levels and free/total prostate-specific antigen ratio.
AB - To study the effect of transrectal ultrasonography (TRUS) on serum total prostate
specific antigen (PSA), free PSA and free/total (f/t) PSA ratio and to determine
the reliability of serum total and free PSA levels and f/t PSA ratio after such
interventions, serum free and total PSA levels and f/t PSA ratios were determined
before, immediately after and 24 h after TRUS in 44 patients who were referred to
our department by their general practitioner for prostate screening. The duration
of TRUS procedure and prostate volume and age were evaluated to determine whether
the serum PSA levels following TRUS had changed. The total PSA and free PSA
levels and f/t PSA ratio did not show any significant rise immediately after DRE
and TRUS. The duration of the TRUS procedure did not appear to affect the PSA
values. Age and prostate volume were not correlated with the PSA levels. Our
findings revealed no significant changes in f/t PSA ratio and serum free and
total PSA level, suggesting that serum free and total PSA levels and f/t PSA
ratio may be more reliable parameters in the early period after TRUS.
PMID- 10782029
TI - Urologic complications of extravesical ureteroneocystostomy in renal
transplantation from living related donors.
AB - INTRODUCTION: Reconstruction of the urinary system during renal transplantation
is usually performed with antirefluxive ureteroneocystostomy techniques and
extravesical methods are usually preferred. MATERIAL AND METHODS: Between 1983
and 1997, 241 renal transplantations from living donors were performed at our
institution. A variation of the Lich-Gregoir technique was used as the
ureteroneocystostomy method in all cases. RESULTS: A total of 12 (4.9%) urologic
complications were observed. Urinary fistula developed in 5 (2%) cases and were
explored surgically during the early postoperative period. Postoperative
vesicoureteral reflux (VUR) to the transplanted kidney was identified in 7 (2.9%)
cases. Either endoscopic or surgical interventions resolved VUR in 4 cases while
the other 3 did not need further treatment. No ureteral stenosis was observed.
There was no loss of graft due to urologic complications. CONCLUSIONS: Urologic
complications after renal transplantation are reported to be about 7% and
ischemia is blamed as the major contributing factor. Preparation of the native
ureter during donor nephrectomy and preservation of distal periureteral fatty
tissue, anastomosis technique variations in vascular anatomy, rejections and
medications are the major factors determining the ischemia.
PMID- 10782031
TI - Extracorporeal shock wave lithotripsy monotherapy of 'stoned' internal ureteral
stent in children. Case report.
AB - A case of ESWL treatment, as monotherapy, of a 'stoned' ureteral stent in a 12
year-old boy was described. Two years previously, the patient had pyelolithotomy
with staghorn stone removal, and double-J stent was left indwelling
intraoperatively. The patient was lost for follow-up for 2 years, when he had
multiple stone formation adherent to the whole length of the stent. Four ESWL
sessions were required before the stent was freed for removal.
PMID- 10782030
TI - Carcinoma following augmentation ileocystoplasty.
AB - Carcinoma of the bladder following augmentation cystoplasty is rare. Only 15
cases have been reported worldwide. We report a further 2 cases, 1 of which, a
squamous cell carcinoma, has not previously been described in this context.
PMID- 10782032
TI - Focal xanthogranulomatous pyelonephritis with associated bone metaplasia.
AB - Focal xanthogranulomatous pyelonephritis of the left lower pole was accidentally
discovered in a 34-year-old woman at sonography. The patient had no history of
stones and urinary tract infection and both conventional radiology and CT scan
revealed radiated calcifications within a well-circumscribed mass. Surgical
treatment consisted of enucleoresection of the lesion, and histopathology
revealed a nucleus of bone metaplasia. To the best of our knowledge, metaplastic
bone formation has never been documented before with xanthogranulomatous
pyelonephritis.
PMID- 10782033
TI - Leiomyoma of the ureter.
AB - We report a case of leiomyoma of the ureter, and the patient underwent partial
ureteral resection. This is the 8th case reported after 1955, and the clinical
features of ureteral leiomyomas of these 8 cases are discussed.
PMID- 10782034
TI - Open thumb forceps. An unusual foreign body in the urethra: technique of its
removal.
AB - A great variety of foreign bodies in the urethra have been reported in the
literature. Mostly, these cases were reported to emphasize the unusual nature of
the objects requiring technical modifications for their removal. We report an
interesting case of self introduced open thumb forceps into the urethra and
technique of its retrieval.
PMID- 10782035
TI - Treatment of a delayed zipper injury.
AB - Penile zipper injuries have been reported occurring usually in the pediatric
population, and occasionally in adults. Usually, the zipper can be dislodged with
mineral oil or by breaking the median bar. When these attempts fail, a small
elliptical incision may be used to remove the zipper and any devitalized tissue.
PMID- 10782036
TI - Primary adenosquamous and squamous cell carcinoma of the upper urinary tract.
Report on three cases.
AB - Three cases of adenosquamous cell carcinoma and squamous cell carcinoma of the
upper urinary tract are presented. The fact that the urothelium normally has no
glandular or squamous structures renders the pathogenesis of these tumours
interesting. The process is assumed to begin with an urothelial metaplasia
resulting from a reaction to chronic irritation, leading to dedifferentiation,
dysplasias and, in the end, to a squamous cell carcinoma or adenocarcinoma. The
relevant medical histories include chronic episodes of pyelonephritis or
nephrolithiasis. Diagnosis, therapeutic approaches and prognosis of these rare
tumours are discussed.
PMID- 10782037
TI - Incidental prostate cancer: the importance of complete prostatic removal at
cystoprostatectomy for bladder cancer.
AB - Patients with invasive bladder cancer could be at a higher risk for a second
malignancy such as an unsuspec- ted prostate cancer. We report a case of muscle
invasive transitional cell carcinoma of the urinary bladder with incidental
adenocarcinoma of prostate, and review the literature to highlight the importance
of complete prostatic removal to prevent residual disease.
PMID- 10782038
TI - Metastatic malignant melanoma presenting as bilateral incidentalomas.
AB - Incidentally discovered adrenal masses often pose a diagnostic challenge in the
asymptomatic patient. The majority represent functional adrenal adenomas but
primary or secondary malignancy must be considered. Bilateral incidentalomas are
rare, and a case of asymptomatic bilateral adrenal melanoma metastases is
presented. The diagnostic and treatment strategies relevant to this clinical
problem are presented and discussed.
PMID- 10782039
TI - An unusual retroperitoneal cystic tumor.
AB - This report describes a case of textiloma (term given to an inflammatory swelling
caused by a retained textile foreign body) in a 60-year-old patient who had
undergone surgery for a perforated gastroduodenal ulcer 17 years earlier. On
examination the presence of a large mass was detected on the left hypochondria. A
CT scan confirmed a cystic tumor with images suggesting detritus or necrosis in
its lower part, as well as calcifications. Transperitoneal midline laparotomy was
performed with extension by thoracophrenolaparotomy. Splenectomy was necessary.
Macroscopic examination showed a spherical mass. After opening the tumor,
retained surgical gauze was found. The histopathological diagnosis was
granulomatosis reaction to a foreign body.
PMID- 10782040
TI - Cardiac opioids.
AB - Opioid peptides have long been considered as neuropeptides or neurotransmitters.
The more recent discovery of these same peptides in non-neuronal tissue suggests
that the peptides may have autocrine, paracrine, or endocrine functions as well.
The opioid peptides, enkephalins, dynorphins, and endorphins, have been found in
isolated cardiac myocytes and heart tissue. This review will cover the recent
literature on opioid peptides in respect to cardiac distribution, biochemistry,
and function.
PMID- 10782041
TI - Feedback and hormonal regulation of hepatic 3-hydroxy-3-methylglutaryl coenzyme A
reductase: the concept of cholesterol buffering capacity.
AB - Regulation of the expression of hepatic 3-hydroxy-3-methylglutaryl coenzyme A
(HMG-CoA) reductase by the major end product of the biosynthetic pathway,
cholesterol, and by various hormones is critical to maintaining constant serum
and tissue cholesterol levels in the face of an ever-changing external
environment. The ability to downregulate this enzyme provides a means to buffer
the body against the serum cholesterol-raising action of dietary cholesterol. The
higher the basal expression of hepatic HMG-CoA reductase, the greater the
"cholesterol buffering capacity" and the greater the resistance to dietary
cholesterol. This review focuses on the mechanisms of feedback and hormonal
regulation of HMG-CoA reductase in intact animals rather than in cultured cells
and presents the evidence that leads to the proposal that regulation of hepatic
HMG-CoA reductase acts as a cholesterol buffer. Recent studies with animals have
shown that feedback regulation of hepatic HMG-CoA reductase occurs at the level
of translation in addition to transcription. The translational efficiency of HMG
CoA reductase mRNA is diminished through the action of dietary cholesterol.
Oxylanosterols appear to be involved in this translational regulation. Feedback
regulation by dietary cholesterol does not appear to involve changes in the state
of phosphorylation of hepatic HMG-CoA reductase or in the rate of degradation of
this enzyme. Several hormones act to alter the expression of hepatic HMG-CoA
reductase in animals. These include insulin, glucagon, glucocorticoids, thyroid
hormone and estrogen. Insulin stimulates HMG-CoA reductase activity likely by
increasing the rate of transcription, whereas glucagon acts by opposing this
effect. Hepatic HMG-CoA reductase activity undergoes a significant diurnal
variation due to changes in the level of immunoreactive protein primarily
mediated by changes in insulin and glucagon levels. Thyroid hormone increases
hepatic HMG-CoA reductase levels by acting to increase both transcription and
stability of the mRNA. Glucocorticoids act to decrease hepatic HMG-CoA reductase
expression by destabilizing reductase mRNA. Estrogen acts to increase hepatic HMG
CoA reductase activity primarily by stabilizing the mRNA. Deficiencies in those
hormones that act to increase hepatic HMG-CoA reductase gene expression lead to
elevations in serum cholesterol levels. High basal expression of hepatic HMG-CoA
reductase, whether due to genetic or hormonal factors, appears to result in
greater cholesterol buffering capacity and thus increased resistance to dietary
cholesterol.
PMID- 10782042
TI - Does the insulin-like growth factor system interact with prostaglandins and
proinflammatory cytokines during neurodegeneration?
AB - Prostaglandins and proinflammatory cytokines are implicated in the etiology of
neurodegenerative diseases, such as Alzheimer's disease. Signaling cascades
initiated by these factors may result in reactive oxygen species generation and
cell death. The insulin-like growth factors (IGF) are ubiquitous polypeptides
involved in all aspects of growth and development. Additionally, the IGF are
regarded as survival factors that display potent antiapoptotic activity.
Interfering with IGF production, distribution, or signaling may result in greater
susceptibility to apoptotic stimuli. In neurodegenerative conditions, the IGF
appear to be antagonized by prostaglandins and proinflammatory cytokines. In this
review, the relationship among specific prostaglandins, the proinflammatory
factors, tumor necrosis factor, interleukin-1, and interleukin-6, and the IGF
system will be investigated.
PMID- 10782043
TI - Topical insulin and accumulation of excitotoxic and other amino acids in ischemic
rat cerebral cortex.
AB - Insulin plays a neuroprotectant role in the brain and spinal cord during
ischemia. However, studies have shown insulin to increase the sensitivity of
cultured cortical cells to glutamate toxicity. The present study looked at the
relationship between topically administered insulin (1 mIU insulin/ml and 100 mIU
insulin/ml) during a four-vessel model of global ischemia and the accumulation of
amino acids, especially glutamate, from the ischemic rat cerebral cortex. The
lower dose of insulin was found to attenuate the release of excitotoxic and other
amino acids from the cortex in ischemia/reperfusion. This may occur because
insulin increases glucose availability to glial cells resulting in maintenance of
glycolysis and ionic pumps that can reduce glutamate release and maintain uptake
during ischemia/reperfusion. The higher dose of insulin, which significantly
increased the amount of aspartate, glutamate, taurine, and GABA during
reperfusion, may act to stimulate the amount of glycogen stored in astrocytes,
reducing the availability of glucose for metabolic purposes.
PMID- 10782044
TI - The familial mediterranean fever protein interacts and colocalizes with a
putative Golgi transporter.
AB - The biological function of pyrin, the protein mutated in Familial Mediterranean
Fever (FMF), has not been elucidated. Based on sequence homology, a transcription
factor activity was proposed for this neutrophil-specific protein. In a yeast two
hybrid assay, neither transcription activation activity nor any self interaction
was detected for pyrin. Screening of an expression cDNA library of peripheral
blood leukocytes using as bait the carboxyl portion of pyrin (amino acids 557
781), which contains most of the FMF mutations, led to the identification of P/M
IP1 (pyrin/marenostrin interacting protein 1). A splice variant of P/M-IP1, GTC
90, had previously been described as a component of the 13S hetero-oligomeric
protein complex that stimulates in vitro Golgi transport. We have now shown that
P/M-IP1 colocalizes with pyrin in the perinuclear cytoplasm of Cos-7 cells and
that the interaction between these two proteins is impaired by FMF causing
mutations in pyrin. These data suggest that, at some stage of its functional
pathway, pyrin resides in the cytoplasm and might be involved in, or impacted by,
cellular protein sorting by the Golgi apparatus. The data also imply that P/M-IP1
may be involved in the abnormal inflammatory response that occurs in patients
with FMF.
PMID- 10782045
TI - Prolactin stimulation of iodide uptake and incorporation into protein is
polyamine-dependent in mouse mammary gland explants.
AB - Previous studies have demonstrated that the prolactin stimulation of most
lactational processes (casein, lactose, and triglyceride synthesis) requires an
earlier stimulating effect of prolactin on the synthesis of the polyamines.
Spermidine appears to be the specific polyamine required for prolactin to enhance
milk product synthesis. Inorganic iodide is present in milk at more than an order
of magnitude higher concentration than that of the maternal plasma. Since
prolactin stimulates iodide accumulation in milk, the goal of these studies was
to determine the role of the polyamines in this hormone response. Two drugs were
employed in these studies: DFMO (difluoromethylornithine), which inhibits
ornithine decarboxylase, and MGBG [methylglyoxal bis(guanyl-hydrazone)], which
inhibits S-adenosyl methionine decarboxylase. In mammary gland explants from
midpregnant (10-14 days of pregnancy) mice, MGBG at 100 microM abolished the
prolactin stimulation of iodide uptake and incorporation into milk proteins,
whereas DFMO caused a concentration-dependent inhibition of the PRL response.
Selected sensitivity of the MGBG and DFMO inhibitions was validated by a reversal
of the drug inhibitions with the addition of 1 mM spermidine to the culture
medium. These data suggest that the polyamine signaling pathway is involved in
the prolactin stimulation of iodide uptake into milk.
PMID- 10782046
TI - Anticancer agents suppressive for adult parasites of filariasis in Mongolian
jirds.
AB - Eight chemical structures not previously reported to possess antifilarial
activity have been identified. A total of 79 compounds with anticancer properties
were evaluated for possible macrofilaricidal activity against Brugia pahangi and
Acanthocheilonema viteae transplanted into male Mongolian jirds (Meriones
unguiculatus). All eight active compounds were suppressive for the onchocerciasis
type (Acanthocheilonema viteae) of the disease. None was macrofilaricidal for the
lymphatic form (Brugia pahangi). These new structures may represent a nucleus
around which effective drugs can be synthesized.
PMID- 10782047
TI - Intraluteal administration of a nitric oxide synthase blocker stimulates
progesterone and oxytocin secretion and prolongs the life span of the bovine
corpus luteum.
AB - To test the role of nitric oxide (NO) in secretory functions of bovine corpora
lutea (CL), two groups of four Holstein heifers each were treated as follows:
Group 1, Nomega-Nitro-L-Arginine Methyl Ester (L-NAME), an inhibitor of nitric
oxide synthase (NOS), on Day 11 or 12 of the cycle and Group 2, L-NAME on Days 17
and 18 of the cycle. All treatments were administered by an intraluteal
microdialysis system (MDS). Drugs were infused for 4-hr periods on the designated
days, and the treatment periods were preceded and followed by 4-hr control
periods. Perfusate and jugular blood samples were collected at half-hour
intervals. Perfusate samples were analyzed for progesterone (P4), oxytocin (OT),
prostaglandin F2alpha (PGF2alpha), and leukotriene C4 (LTC4); jugular plasma
samples were analyzed for P4, OT, and LH. Perfusion of L-NAME on Day 11 or 12
consistently increased P4 concentration in the perfusate, but had no effect on
the life span of the CL. Perfusion of L-NAME on Days 17-18 also elevated P4
levels in the perfusate, and in addition, maintained P4 levels in the plasma of
three of the four treated animals through Day 25 of the cycle. L-NAME perfusion
also increased OT release concomitant with P4 into the perfusate at both the mid-
and late-luteal phase treatments. For the most part, concentrations of LH, OT,
and P4 in the jugular plasma samples collected during the perfusions were
unaffected by treatments. L-NAME perfusion caused small, but significant (P <
0.05) increases in perfusate PGF2alpha and LTC4 at Days 17 and 18 and in LTC4 on
Day 11 or 12. These data indicate that NO plays a direct luteolytic role in
regression of the bovine CL.
PMID- 10782048
TI - CD27: a memory B-cell marker.
PMID- 10782049
TI - The IL-1 receptor/toll-like receptor superfamily: crucial receptors for
inflammation and host defense.
PMID- 10782050
TI - Clinical immunology: a unified vision for Europe.
PMID- 10782052
TI - Putting priming into perspective - from cellular heterogeneity to cellular
plasticity.
AB - The concept of priming is widely used in cell biology and has come to mean the
functional enhancement of a given cell by cytokines. 'Primed' cells have a number
of other cellular alterations, although the relationship between functional and
phenotypical diversity has not been established. Here, Claus Kroegel and
colleagues discuss the dynamic nature of inflammatory-cell priming, which might
be part of a broader means of comprehending cell function in disease.
PMID- 10782051
TI - How can dendritic cells cause autoimmune disease?
AB - Immune responses against foreign antigens are initiated and controlled by
dendritic cells (DCs). Accumulating evidence suggests that autoimmunity,
involving T cells directed against self, can also be primed by DCs. We propose
that DCs could induce autoimmunity following their differentiation by certain
cytokines, or because of intrinsic defects in genes controlling DC function. Both
processes result in DCs that behave deviantly.
PMID- 10782053
TI - Searching for significance in TCR-cytoskeleton interactions.
AB - Two T-cell receptor (TCR) populations are expressed on T cells; one is linked to
the cytoskeleton via its zeta chain. These cytoskeleton-linked receptors (30-40%
of the total number of TCRs) might be important in TCR-mediated signaling and/or
concurrent events. Here, differences between the two populations are summarized,
and new data are examined to speculate on the functional significance of
cytoskeleton-linked TCRs.
PMID- 10782055
TI - CCL chemokines and asthma.
AB - Airway eosinophilia is a characteristic of bronchial asthma. Eosinophils are
considered to cause tissue damage through the release of toxic proteases, lipid
mediators, cytokines and oxygen free radicals. The discovery of chemokines and
the demonstration that some members of this cytokine superfamily are implicated
in the recruitment of eosinophils offers an opportunity for a novel therapeutic
approach in asthma.
PMID- 10782054
TI - Natural cytotoxicity receptors that trigger human NK-cell-mediated cytolysis.
AB - Natural killer (NK) cells can detect whether cells have undergone tumour
transformation or viral infection. The discovery of specific inhibitory receptors
for major histocompatibility complex class I molecules clarified the basis of
this discrimination. However, the receptors responsible for NK-cell triggering in
the process of natural cytotoxicity remained elusive until recently. Here,
Alessandro Moretta and colleagues describe the identification and
characterization of several such receptors.
PMID- 10782056
TI - Poxviral mimicry of complement and chemokine system components: what's the end
game?
AB - Numerous viral proteins mimic host immunoregulatory proteins, both structurally
and functionally. This phenomenon appears to underlie viral evasion of host
defense. These viral immunomodulatory proteins block viral neutralization and
destruction of infected cells, and are also able to influence their habitat,
preserving habitats that favor their growth and that of their progeny. The end
game seems to vary widely among viruses.
PMID- 10782057
TI - Clean living increases more than just atopic disease.
PMID- 10782058
TI - Reply to rook
PMID- 10782059
TI - Tryptophan degradation to control T-cell responsiveness.
PMID- 10782060
TI - Popping a pill to regulate therapeutic protein delivery.
PMID- 10782061
TI - Pneumococci self-destruct.
PMID- 10782062
TI - Engineered macrophages: a new weapon in the war on cancer?
PMID- 10782063
TI - Mitochondrial gene linked to rare hereditary tumour.
PMID- 10782064
TI - Mucosal protection against HIV - a new role for IgG?
PMID- 10782065
TI - Virtual molecular medicine in developing countries: the Mexican initiative.
AB - The limited resources of developing countries are forcing them to search for
different options to keep up with the accelerating pace of research into genetic
medicine. In Mexico, one such option is the Mexican Network of Molecular
Biomedicine (MNMB). With the Internet as a means of communication and a source of
information, the MNMB aims to provide a program based on cooperation, high
quality service and patient care.
PMID- 10782066
TI - Fragile X syndrome at the turn of the century.
AB - Fragile X syndrome is not only the most common form of inherited cognitive
impairment, it is also one of the most frequent single gene disorders. It is
caused by a stretch of CGG-repeats within the fragile X gene, which increases in
length as it is transmitted from generation to generation. Once the repeat
exceeds a threshold length, no fragile X protein is produced and disease results.
Since the mutation was discovered, nearly a decade of research has revealed a
wealth of information regarding the fragile X gene and its possible function
within the cell. The fragile X story also provides a sobering example of how much
time and effort might be necessary to develop beneficial treatment through
understanding gene function.
PMID- 10782067
TI - Xenotransplantation: is the risk of viral infection as great as we thought?
AB - Two major hurdles remain before xenotransplantation can enter the clinic. The
first is the more technical issue of being able to overcome the human immune
response that leads to rejection of transplanted organs/cells from other species.
The second, reviewed here, concerns the potential risk of inadvertent transfer of
animal viruses present in the xenotransplant that are able to infect the human
recipient. The threat from viruses is a particularly contentious topic because it
poses a risk not only to those individuals who receive xenotransplants, but also
to healthy individuals who come into contact, either directly or indirectly, with
the xenotransplant recipient. In this review, we describe some of the virus
types, in addition to the much discussed porcine endogenous retroviruses that
might cross the species barrier, and assess the risk of such viruses causing
disease in human hosts.
PMID- 10782068
TI - The NC/Nga mouse: a model for atopic dermatitis.
PMID- 10782069
TI - Molecular approaches to malaria.
PMID- 10782070
TI - Wolbachia bacteria of filarial nematodes: a target for control?
PMID- 10782072
TI - Parasite genomes: A special issue of international journal of parasitology
PMID- 10782071
TI - What should schools do about malaria?
PMID- 10782073
TI - Situation analysis of malaria in school-aged children in Kenya - what can be
done?
PMID- 10782074
TI - The link between helminthic infection and atopy.
PMID- 10782075
TI - The strange case of Leishmania chagasi.
PMID- 10782076
TI - Albumax and global warming on the Web
PMID- 10782077
TI - Vaccination against cysticercosis and hydatid disease.
AB - Infections with the larval stages of taeniid cestode parasites cause substantial
human morbidity as well as economic losses in domestic livestock species. Despite
ongoing efforts around the world, few countries have been able substantially to
reduce or eradicate these infections through the use of anthelmintics and
lifestyle changes. Vaccines offer an additional potential tool to assist with the
control of parasite transmission. Here, Marshall Lightowlers and colleagues
review the substantial progress that has been made towards developing practical
vaccines against hydatid disease in sheep and cysticercosis in sheep and cattle.
Recombinant antigens have been used to induce more than 90% protection against
challenge infections. Such success in animals encourages investigation of the
potential use of vaccines in humans to prevent hydatid disease arising from
infection with Echinococcus granulosus and cysticercosis from infection with
Taenia solium.
PMID- 10782078
TI - The journey of the malaria parasite in the mosquito: hopes for the new century.
AB - In this review, Anil Ghosh, Marten Edwards and Marcelo Jacobs-Lorena follow the
journey of the Plasmodium parasite in the mosquito vector. At each developmental
step, they highlight some of the major unanswered questions currently challenging
cell and molecular biologists. A more thorough understanding of Plasmodium
mosquito interactions might lead to the development of mosquitoes unable to
support parasite development.
PMID- 10782080
TI - The role of eosinophils in parasitic helminth infections: insights from
genetically modified mice.
AB - Eosinophilia - an increase in the number of eosinophils in the blood or tissues -
has historically been recognized as a distinctive feature of helminth infections
in mammals. Yet the precise functions of these cells are still poorly understood.
Many scientists consider that their primary function is protection against
parasites, although there is little unequivocal in vivo evidence to prove this.
Eosinophils are also responsible for considerable pathology in mammals because
they are inevitably present in large numbers in inflammatory lesions associated
with helminth infections or allergic conditions. In this review, Carolyn Behm and
Karen Ovington outline some of the cellular and biological properties of
eosinophils and evaluate the evidence for their role(s) in parasitic infections.
PMID- 10782081
TI - Nomenclature and genetic groupings of Giardia infecting mammals.
AB - Giardia is a ubiquitous and well-known enteric parasite affecting humans and a
range of domestic and wild mammals. It is one of the most common parasites of
domestic dogs and dairy cattle and a frequently recognized waterborne pathogen.
Giardiasis is considered to be a re-emerging infection because of its association
with outbreaks of diarrhoea in child-care centres. Although only a single species
has been recognized as causing disease in humans and most other mammals,
molecular characterization of morphologically identical isolates from humans and
numerous other species of mammals has confirmed the heterogeneity of this
parasite and provided a basis for a clearer understanding of the taxonomy and
zoonotic potential of Giardia.
PMID- 10782082
TI - Giardia vaccination.
AB - Recently, a Giardia vaccine has become commercially available in the USA for
prevention of clinical signs of giardiasis and reduction of cyst shedding in dogs
and cats. The vaccine is based upon the current state of knowledge of Giardia
antigenicity and immunology. Here, Merle Olson, Howard Ceri and Douglas Morck
describe studies that led to the development of this vaccine and subsequent
efficacy studies. Immunoprophylaxis and immunotherapeutic application of the
vaccine are discussed.
PMID- 10782084
TI - Reply
PMID- 10782083
TI - The concept of virulence.
PMID- 10782086
TI - Chaperone substrates inside the cell.
PMID- 10782085
TI - Footprints of aminoacyl-tRNA synthetases are everywhere.
PMID- 10782087
TI - The changing face of mitochondrial research.
PMID- 10782088
TI - Regulation of mitochondrial metabolism by ER Ca2+ release: an intimate
connection.
AB - New live-cell imaging techniques indicate that mitochondria exist in the living
cell as a continuous interconnected mitochondrial reticulum, or 'MR', closely
associated with the endoplasmic reticulum (ER). Ca2+ ions released from the ER in
response to hormonal stimulation might thus be preferentially transferred into
the mitochondrial matrix causing the local activation of ATP synthesis. Ca2+
uptake into the MR might also subtly modify the activity of ER Ca2+ release
channels and thus the dynamics of cytosolic Ca2+ oscillations and waves.
PMID- 10782089
TI - Paul Sigler (1934-2000).
PMID- 10782090
TI - The NACHT family - a new group of predicted NTPases implicated in apoptosis and
MHC transcription activation.
PMID- 10782091
TI - FAT: a novel domain in PIK-related kinases.
PMID- 10782092
TI - Nuclear receptors arose from pre-existing protein modules during evolution.
PMID- 10782093
TI - Phosphoinositide signaling and the regulation of membrane trafficking in yeast.
AB - Phosphoinositides are key regulators of diverse cellular processes in eukaryotic
cells. Genetic studies in yeast have advanced our understanding of how
phosphoinositide-signaling pathways regulate membrane trafficking. Enzymes
required for the synthesis (kinases) and turnover (phosphatases) of distinct
phosphoinositides have been identified and several downstream effector molecules
linked to phosphoinositide signaling have recently been characterized.
PMID- 10782094
TI - 'Florigen' enters the molecular age: long-distance signals that cause plants to
flower.
AB - The transition from vegetative to reproductive growth is a critical event in the
life cycle of plants. Previous physiological studies have deduced that hormone
like substances mediate this important transition but the biochemical nature of
the putative signaling molecules has remained elusive. Recent molecular and
genetic studies of key flowering-time genes offer new approaches to understanding
the mechanisms underlying the initiation of flowering.
PMID- 10782096
TI - Proteins binding to duplexed RNA: one motif, multiple functions.
AB - Highly structured and double-stranded (ds) RNAs are adaptable and potent
biochemical entities. They interact with dsRNA-binding proteins (RBPs), the great
majority of which contain a sequence called the dsRNA-binding motif (dsRBM). This
approximately 70-amino-acid sequence motif forms a tertiary structure that
interacts with dsRNA, with partially duplexed RNA and, in some cases, with RNA
DNA hybrids, generally without obvious RNA sequence specificity. At least nine
families of functionally diverse proteins contain one or more dsRBMs. The motif
also participates in complex formation through protein-protein interactions.
PMID- 10782098
TI - Protein Annotators' assistant.
PMID- 10782097
TI - AAA proteases: cellular machines for degrading membrane proteins.
AB - AAA proteases are a conserved class of ATP-dependent proteases that mediate the
degradation of membrane proteins in bacteria, mitochondria and chloroplasts. They
combine proteolytic and chaperone-like activities and thus form a membrane
integrated quality-control system. Inactivation of AAA proteases causes severe
defects in various organisms, including neurodegeneration in humans. Proteolysis
by AAA proteases is modulated by another membrane-protein complex that is
composed of prohibitins in eukaryotic cells and related proteins in bacteria.
PMID- 10782099
TI - A contribution to chemical defence in World War II.
PMID- 10782100
TI - On the immunity principle: a view from a robot.
PMID- 10782101
TI - Reply to Cole, Sacks and Waterman.
PMID- 10782102
TI - Contextual cueing of visual attention.
AB - Visual context information constrains what to expect and where to look,
facilitating search for and recognition of objects embedded in complex displays.
This article reviews a new paradigm called contextual cueing, which presents well
defined, novel visual contexts and aims to understand how contextual information
is learned and how it guides the deployment of visual attention. In addition, the
contextual cueing task is well suited to the study of the neural substrate of
contextual learning. For example, amnesic patients with hippocampal damage are
impaired in their learning of novel contextual information, even though learning
in the contextual cueing task does not appear to rely on conscious retrieval of
contextual memory traces. We argue that contextual information is important
because it embodies invariant properties of the visual environment such as stable
spatial layout information as well as object covariation information. Sensitivity
to these statistical regularities allows us to interact more effectively with the
visual world.
PMID- 10782103
TI - Infant artificial language learning and language acquisition.
AB - The rapidity with which children acquire language is one of the mysteries of
human cognition. A view held widely for the past 30 years is that children master
language by means of a language-specific learning device. An earlier proposal,
which has generated renewed interest, is that children make use of domain
general, associative learning mechanisms. However, our current lack of knowledge
of the actual learning mechanisms involved during infancy makes it difficult to
determine the relative contributions of innate and acquired knowledge. A recent
approach to studying this problem exposes infants to artificial languages and
assesses the resulting learning. In this article, we review studies using this
paradigm that have led to a number of exciting discoveries regarding the learning
mechanisms available during infancy. These studies raise important issues with
respect to whether such mechanisms are general or specific to language, the
extent to which they reflect statistical learning versus symbol manipulation, and
the extent to which such mechanisms change with development. The fine-grained
characterizations of infant learning mechanisms that this approach permits should
result in a better understanding of the relative contributions of, and the
dynamic between, innate and learned factors in language acquisition.
PMID- 10782105
TI - On the relation of speech to language.
AB - There are two widely divergent theories about the relation of speech to language.
The more conventional view holds that the elements of speech are sounds that rely
for their production and perception on two wholly separate processes, neither of
which is distinctly linguistic. Accordingly, the primary motor and perceptual
representations are inappropriate for linguistic purposes until a cognitive
process of some sort has connected them to language and to each other. The less
conventional theory takes the speech elements to be articulatory gestures that
are the primary objects of both production and perception. Those gestures form a
natural class that serves a linguistic function and no other. Therefore, their
representations are immediately linguistic, requiring no cognitive intervention
to make them appropriate for use by the other components of the language system.
The unconventional view provides the more plausible answers to three important
questions: (1) How was the necessary parity between speaker and listener
established in evolution, and how maintained? (2) How does speech meet the
special requirements that underlie its ability, unique among natural
communication systems, to encode an indefinitely large number of meanings? (3)
What biological properties of speech make it easier than the reading and writing
of its alphabetic transcription?
PMID- 10782106
TI - Situating vision in the world.
AB - Recently, there has been a great deal of interest in what has been called
'situated cognition', which has included claims that certain forms of
representation are inadequate for modeling active organisms or agents such as
humans and robots. In this article, I suggest that a weakness in classical
theories of visual representation is the way in which representations connect
with the real world, which may account for many of the concerns expressed by the
situated cognition community. Specifically, I claim that what current theories
lack is any provision for a certain form of direct, preconceptual connection
between objects in the visual world (visual objects or proto-objects) and their
representations in the visual system. This type of connection is akin to what
philosophers and semanticists have referred to as an 'indexical' or
'demonstrative' reference and what some cognitive scientists have referred to as
'deictic pointers'. I explain why such a mechanism is needed and suggest that
many workers have, in fact, been studying precisely this under the term 'visual
index'. The visual index hypothesis is illustrated with the results of some
relevant experiments, including multiple object tracking, visual routines and
subset-selected visual searches. Indexing theory provides a synthesis that has
profound implications for explaining a wide range of psychophysical findings,
certain results in infant cognitive development and also some ancient problems in
the philosophy of mind.
PMID- 10782107
TI - Just the right size: cell counting in Dictyostelium.
AB - The regulation of tissue and organism size plays an essential, but poorly
understood, role in multicellular development. Genes have been identified that
affect body and organ size in a number of animals. Two recently identified genes,
smlA and countin, are required for the proper function of a cell-counting
mechanism that regulates organism size in the eukaryotic microorganism
Dictyostelium discoideum. The discovery of this process now allows the study of
size regulation in a simple multicellular system.
PMID- 10782108
TI - Dyskeratosis congenita, telomeres and human ageing.
AB - As normal humans age, telomeres shorten in tissues that contain dividing cells,
and this has been proposed both as a cause of ageing and as a tumor-suppressor
mechanism. The surprising finding that cells from individuals with the rare
inherited disorder dyskeratosis congenita (DKC) have reduced levels of telomerase
and shortened telomeres might provide the first direct genetic test of the
function of telomeres in intact humans.
PMID- 10782109
TI - Horizontal transfer of catalase-peroxidase genes between archaea and pathogenic
bacteria.
PMID- 10782110
TI - Towards a structural basis of human non-synonymous single nucleotide
polymorphisms.
PMID- 10782111
TI - Unified nomenclature for the COP9 signalosome and its subunits: an essential
regulator of development.
PMID- 10782112
TI - Author's correction
PMID- 10782114
TI - Proteoglycans and pattern formation: sugar biochemistry meets developmental
genetics.
AB - While it has been long appreciated that sugar-modified proteins coat the cell
surface, their functions are poorly understood. Here, I describe recent genetic
studies that demonstrate that one class of sugar-modified proteins, cell-surface
proteoglycans, play crucial roles in morphogenesis, growth regulation and tumor
suppression. Mutations that affect individual proteoglycans or the enzymes
required for glycosaminoglycan synthesis regulate Wingless and Decapentaplegic
signaling in Drosophila, and body size in mice and humans. Compromising
proteoglycan function is also associated with the development of Wilm's tumors
and hereditary multiple exostoses. In this review, these biological findings are
placed in the context of proteoglycan biochemistry and molecular function.
PMID- 10782115
TI - The Werner syndrome gene: the molecular basis of RecQ helicase-deficiency
diseases.
AB - Werner syndrome (WS) is an autosomal recessive genetic disorder that is
manifested by genetic instability and premature onset of age-related diseases,
including atherosclerosis and cancer. The gene that is mutated in WS cells (WRN)
has been identified recently. Characterizations of the WRN gene product indicate
that WRN encodes both a 3'-->5' DNA helicase, belonging to the Escherichiacoli
RecQ helicase family, and a 3'-->5' DNA exonuclease. Studies to define the
molecular mechanism of WRN-DNA transactions are currently underway in many
laboratories. Preliminary results indicate that WRN functions as a key factor in
resolving aberrant DNA structures that arise from DNA metabolic processes such as
replication, recombination and/or repair, to preserve the genetic integrity in
cells.
PMID- 10782116
TI - A genetic programme for neuronal connectivity.
AB - What is the nature of the genetic programme that allows neurons to extend their
axons and connect to other neurons with a high degree of specificity? Work on the
sensory neurons of the fly has shown how the control of neuronal identity is
embedded in the general developmental programme of the organism. The ongoing
analysis of pathfinding mutants suggests plausible mechanisms for the translation
of neuronal identity into axonal behaviour.
PMID- 10782117
TI - Homology a personal view on some of the problems.
AB - There are many problems relating to defining the terminology used to describe
various biological relationships and getting agreement on which definitions are
best. Here, I examine 15 terminological problems, all of which are current, and
all of which relate to the usage of homology and its associated terms. I suggest
a set of definitions that are intended to be totally consistent among themselves
and also as consistent as possible with most current usage.
PMID- 10782118
TI - Virtual biology in the CAVE.
PMID- 10782119
TI - Gene transfer into neurones for the molecular analysis of behaviour: focus on
herpes simplex vectors.
AB - The use of viral vectors to transfect genes into specific brain-cell populations
is a novel approach that can be used to investigate the molecular and cellular
basis of brain function. Ideal vectors should be targetable and capable of
regulated transgene expression. From the viral vectors developed so far, this
article focuses on herpes simplex virus 1 (HSV-1)-based vectors. HSV-1 vectors
can be engineered for gene transfer to the brain, which makes them suitable for
neuroscience research applications. In particular, genetic manipulations of the
virus can almost eliminate toxicity and allow expression of multiple transgenes
simultaneously. In some instances, transfection of selected neuronal populations
is also possible. Specific alterations in behaviour and in disease models have
been described after the viral-vector-mediated expression of specific genes
within highly localized brain regions.
PMID- 10782120
TI - Long-term plasticity of postsynaptic GABAA-receptor function in the adult brain:
insights from the oxytocin neurone.
AB - The subunit switching of ligand-gated receptors is a potentially important
mechanism through which synaptic plasticity can be achieved in the nervous
system. Although established in an activity-dependent manner for
neurotransmission that is mediated by excitatory amino acids, there is much less
direct evidence for a role of subunit switching in long-term plasticity of GABAA
receptors in the adult. We argue that the hypothalamic oxytocin neurones, which
exhibit marked plasticity through each reproductive cycle, provide an excellent
model of both presynaptic and postsynaptic long-term plasticity of GABA-mediated
transmission in the mature nervous system. The postsynaptic plasticity involves
GABAA-receptor-subunit switching in an activity-independent manner. It also has
profound effects on the electrical behaviour of the oxytocin neurones and, thus,
the neural control of pregnancy and lactation.
PMID- 10782122
TI - Reply
PMID- 10782121
TI - Human retrosplenial cortex: where is it and is it involved in emotion?
PMID- 10782124
TI - Reply
PMID- 10782123
TI - Dendritic spine density in Purkinje cells.
PMID- 10782125
TI - Central control components of a 'simple' stretch reflex.
AB - The monosynaptic stretch reflex is a fundamental feature of sensory-motor
organization in most animal groups. In isolation, it serves largely as a negative
feedback devoted to postural controls; however, when it is involved in diverse
movements, it can be modified by central command circuits. In order to understand
the implications of such modifications, a model system has been chosen that has
been studied at many different levels: the crayfish walking system. Recent
studies have revealed several levels of control and modulation (for example, at
the levels of the sensory afferent and the output synapse from the sensory
afferent, and via changes in the membrane properties of the postsynaptic neuron)
that operate complex and highly adaptive sensory-motor processing. During a given
motor task, such mechanisms reshape the sensory message completely, such that the
stretch reflex becomes a part of the central motor command.
PMID- 10782126
TI - Ascorbate regulation and its neuroprotective role in the brain.
AB - Ascorbic acid (vitamin C) occurs physiologically as the ascorbate anion: a water
soluble antioxidant that is found throughout the body. However, despite the high,
homeostatically regulated levels of brain ascorbate, its specific functions in
the CNS are only beginning to be elucidated. Certainly, it acts as part of the
intracellular antioxidant network, and as such is normally neuroprotective. There
is also evidence that it acts as a neuromodulator. A possibly unique role it
might have is as an antioxidant in the brain extracellular microenvironment,
where its concentration is modulated by glutamate-ascorbate heteroexchange at
glutamate uptake sites. Ongoing studies of ascorbate and glutamate transporters
should lead to rapid progress in understanding ascorbate regulation and function.
PMID- 10782127
TI - Resonance, oscillation and the intrinsic frequency preferences of neurons.
AB - The realization that different behavioural and perceptual states of the brain are
associated with different brain rhythms has sparked growing interest in the
oscillatory behaviours of neurons. Recent research has uncovered a close
association between electrical oscillations and resonance in neurons. Resonance
is an easily measurable property that describes the ability of neurons to respond
selectively to inputs at preferred frequencies. A variety of ionic mechanisms
support resonance and oscillation in neurons. Understanding the basic principles
involved in the production of resonance allows for a simplified classification of
these mechanisms. The characterization of resonance and frequency preference
captures those essential properties of neurons that can serve as a substrate for
coordinating network activity around a particular frequency in the brain.
PMID- 10782129
TI - How learning mechanisms might affect evolutionary processes.
PMID- 10782128
TI - Calcium signaling in the ER: its role in neuronal plasticity and
neurodegenerative disorders.
AB - Endoplasmic reticulum (ER) is a multifaceted organelle that regulates protein
synthesis and trafficking, cellular responses to stress, and intracellular Ca2+
levels. In neurons, it is distributed between the cellular compartments that
regulate plasticity and survival, which include axons, dendrites, growth cones
and synaptic terminals. Intriguing communication networks between ER,
mitochondria and plasma membrane are being revealed that provide mechanisms for
the precise regulation of temporal and spatial aspects of Ca2+ signaling.
Alterations in Ca2+ homeostasis in ER contribute to neuronal apoptosis and
excitotoxicity, and are being linked to the pathogenesis of several different
neurodegenerative disorders, including Alzheimer's disease and stroke.
PMID- 10782130
TI - Human mitochondrial DNA recombination: can it be true?
PMID- 10782131
TI - Niche versus chance and tree diversity in forest gaps.
AB - Studies that are unprecedented in scale, detail or approach show that niche
partitioning contributes less, and chance events more, than expected to
maintaining tree species richness via gap dynamics in tropical and temperate
forests. Some tree species are differentially adapted for regeneration in
different gap microenvironments. However, the stochastic availability of gaps,
and limited recruitment of juveniles, mean that gaps are filled mostly by chance
occupants rather than by best adapted species. This chance survival can slow
competitive exclusion and maintain tree diversity. Gap dynamics do not explain
the latitudinal gradient in tree richness.
PMID- 10782133
TI - Palaeoclimatic records from peat bogs.
AB - The palaeoclimatic record for the past 6000 years, implemented from peat-bog
stratigraphy, has been limited by imprecision in dating and climatic
interpretation. Recently, dating problems have been addressed by 'wiggle-matched'
radiocarbon dates and by volcanic ash layers, promising much tighter correlation
between records from different regions. Recent research shows key dates of
significant climatic change and tentative evidence for periodicity. Application
of time-series analysis, generalized linear modelling and transfer function
models to the proxy climate data show how improved climatic reconstructions can
be obtained. Peat-derived palaeoclimatic data might explain, as well as describe,
climatic changes over timescales of 102-103 years.
PMID- 10782139
TI - An evolutionary no man's land.
PMID- 10782134
TI - Efficient genetic markers for population biology.
AB - Population genetics has come of age. Three important components have come
together: efficient techniques to examine informative segments of DNA, statistics
to analyse DNA data and the availability of easy-to-use computer packages. Single
locus genetic markers and those that produce gene genealogies yield information
that is truly comparable among studies. These markers answer biological questions
most efficiently and also contribute to much broader investigations of
evolutionary, population and conservation biology. For these reasons, single
locus and genealogical markers should be the focus of the intensive genetic data
collection that has begun owing to the power of genetics in population biology.
PMID- 10782132
TI - Evolution of the avian sex chromosomes and their role in sex determination.
AB - Is it the female-specific W chromosome of birds that causes the avian embryo to
develop a female phenotype, analogous to the dominance mode of genic sex
differentiation seen in mammals? Or is it the number of Z chromosomes that
triggers male development, similar to the balance mode of differentiation seen in
Drosophila and Caenorhabditis elegans? Although definite answers to these
questions cannot be given yet, some recent data have provided support for the
latter hypothesis. Moreover, despite the potentially common features of sex
determination in mammals and birds, comparative mapping shows that the avian sex
chromosomes have a different autosomal origin than the mammalian X and Y
chromosomes.
PMID- 10782135
TI - No inconsistencies in sensitivity analysis.
PMID- 10782138
TI - Reply from R. Carroll.
PMID- 10782136
TI - Reply from M. Mesterton-Gibbons.
PMID- 10782137
TI - A new evolutionary synthesis: do we need one?
PMID- 10782140
TI - Reply from L.G. Harshman and A.A. Hoffmann.
PMID- 10782141
TI - Transgenic organisms in evolutionary ecology.
AB - Evolutionary ecology aims to understand how phenotypes are designed for
reproductive success and survival. Perhaps the most powerful approach towards
this goal is to alter a character genetically and observe the resulting change in
reproduction, survival, growth, defense or competitive ability. Until recently,
this strategy was not practical. Transgenic manipulation now offers a solution -
novel genes are introduced into the germ line and are then expressed in the
developing organism. This technique is already available in model and
agricultural organisms. The challenge for molecular evolutionary ecologists is to
find ways to adopt these powerful systems to understand the mechanisms underlying
adaptive traits and their evolution.
PMID- 10782142
TI - Fatal pulmonary tumor embolism caused by chondroblastic osteosarcoma.
PMID- 10782143
TI - The extraordinary career of Dr Purkinje.
PMID- 10782145
TI - Follow-up of abnormal gynecologic cytology: a college of American pathologists Q
probes study of 16132 cases from 306 laboratories.
AB - OBJECTIVES: To measure the percentage of women with abnormal gynecologic cytology
who have follow-up within 1 year and to identify patient and laboratory
characteristics associated with higher percentages of follow-up. DESIGN AND
SETTING: Retrospective identification of patients with abnormal cervicovaginal
cytology and identification of the initial clinical follow-up activity during the
12 months following the cytologic diagnosis. MAIN OUTCOME MEASURE: Percentage of
women receiving follow-up. RESULTS: Three hundred six laboratories reported
follow-up information on 16 132 patients with gynecologic cytology diagnoses of
carcinoma, high-grade squamous intraepithelial lesion, low-grade squamous
intraepithelial lesion, or glandular intraepithelial lesion. The following
percentages of women received follow-up within 1 year: 85.6% of patients with
cytologic diagnoses of carcinoma, 87.2% with diagnoses of high-grade squamous
intraepithelial lesion, 82.7% with diagnoses of low-grade squamous
intraepithelial lesion, and 84.9% with diagnoses of glandular intraepithelial
lesion. Within 6 months, 82.2% of patients with cytologic diagnoses of carcinoma,
82.4% with diagnoses of high-grade squamous intraepithelial lesion, 71.9% with
diagnoses of low-grade squamous intraepithelial lesion, and 74.7% with diagnoses
of glandular intra-epithelial lesion received follow-up. Overall, 90. 8% of
patients who received follow-up within the 1-year time frame of this study had
their follow-up completed within 6 months. Specific follow-up activities and
their frequencies are listed for each diagnostic category. Patients 30 years old
or younger and pregnant patients had lower follow-up percentages. CONCLUSIONS:
With less than 83% of patients with high-grade squamous intraepithelial lesion or
carcinoma cytology findings having available documentation of follow-up within 6
months, and less than 88% within 1 year, there is room for improvement in this
area of health care. Monitoring and critical analysis of the follow-up process is
a starting point for improvement.
PMID- 10782146
TI - Quality management in gynecologic cytology using interlaboratory comparison.
AB - OBJECTIVE: To describe a comprehensive integrated laboratory quality management
plan for gynecologic cytology. DESIGN AND SETTING: Cytopathology laboratory
performance monitors with interlaboratory comparison. RESULTS: Utilizing College
of American Pathologists Q-Probes studies, the College of American Pathologists
Interlaboratory Comparison Program in Cervicovaginal Cytology, and other
published data, a quality management program for gynecologic cytology involving
diagnostic statistics, screening limits and competency assessment, retrospective
rescreening, real-time rescreening, cytology-biopsy correlation, follow-up of
patients with abnormal cytology results, turnaround time, examination of unknown
slides (survey programs), and new technology is described. CONCLUSION: Regular
coordinated monitoring of performance, with longitudinal and interlaboratory
comparison utilizing the methods described, provides an opportunity to optimize
gynecologic cytology service.
PMID- 10782147
TI - Synchronous occurrence of epithelial and stromal tumors in the stomach: a report
of 6 cases.
AB - OBJECTIVE: The synchronous development of epithelial and stromal tumors in the
stomach has been reported rarely in the literature. A series of 6 such cases is
described in this article. METHODS: Clinical and pathologic data were recorded
and the literature was reviewed. RESULTS: Five cases featured the simultaneous
occurrence of stromal tumors (1 benign, 3 borderline, 1 malignant) and
adenocarcinomas, whereas the stromal tumor in the sixth case was found in
association with a carcinoid. No collision tumors were observed. In 2 cases,
tumors arose from the same site and were closely juxtaposed, but in 4 patients
they developed from different areas of the stomach. A preoperative histologic
diagnosis of both tumors was not achieved in any case. Two patients harbored
occult infiltrative epithelial lesions (1 diffuse-type adenocarcinoma, 1
carcinoid), which were detected only at pathologic examination of the gastric
mucosa adjacent to the stromal tumor. CONCLUSIONS: The simultaneous occurrence of
epithelial and stromal tumors in the stomach can be less rare than usually
expected. Coincidence alone could account for such an association, particularly
in areas with high incidence rates of gastric cancer. The hypothesis that a
single carcinogenic agent might interact with two neighboring tissues in the
stomach inducing the development of tumors of different histotype cannot be
theoretically discarded.
PMID- 10782148
TI - Fas (APO-1/CD95) ligand and Fas expression in renal cell carcinomas: correlation
with the prognostic factors.
AB - BACKGROUND AND OBJECTIVE: Fas ligand (FasL, CD95L) is a type II transmembrane
protein of the tumor necrosis factor family that induces cells to send an
apoptotic signal to cells expressing Fas (CD95, APO-1). It has been shown that
cancers have a dysregulated expression of Fas and FasL system, conferring a
survival advantage. It is important to understand FasL and Fas expression in
tumors, because the growth of cancer might be controlled by Fas-mediated
apoptosis. METHODS: The expressions of FasL and Fas were studied by
immunohistochemical analyses in 51 cases of renal cell carcinomas and the
adjacent normal renal tissues, respectively. In addition, their expressions were
compared with prognostic factors, such as tumor size, nuclear grade, TNM stage,
and histologic types. RESULTS: In nonneoplastic renal tissues, FasL was expressed
in all nephron segments, whereas Fas also expressed in all tubules, except for
glomeruli. In renal cell carcinomas, FasL protein was detected in 50 (98.0%) of
51 cases, whereas Fas expressed in 38 (74.5%) of 51 cases. In fact, the
immunostaining of Fas was less intense than that in the adjacent normal segments
of all cases. The staining pattern showing both high expression of FasL and low
expression of Fas was found in 36 (70.6%) (P = .04) of 51 cases, most of which
were Fuhrman grade 2 or 3 tumors. However, the expression pattern did not
correlate statistically with the tumor size, histologic type, or clinical stage.
On the other hand, most grade 4 tumors displayed high expression of both FasL and
Fas (P<.001). CONCLUSION: These data indicate that high expression of FasL and
low expression of Fas protein in renal cell carcinomas may play a role in evading
surveillance of the immune system. In addition, the FasL and Fas expressions
appear to have a therapeutic implication for high-grade tumors rather than a
prognostic one.
PMID- 10782149
TI - Testicular regression syndrome: a clinical and pathologic study of 11 cases.
AB - CONTEXT: The vanishing or regressed testis is an entity well known to urologists
and pediatric surgeons, affecting approximately 5% of patients with
cryptorchidism. However, there is little review and discussion of this entity
among pathologists with only 2 of 40 published reviews of testicular regression
syndrome (TRS) found in the pathologic literature. OBJECTIVES: To assess
recognition of TRS among a subset of pathologists and to determine the
applicability of histologic criteria for TRS as published. DESIGN: An 8-year
retrospective review of cases submitted as atrophic or regressed testis was
performed. Original diagnosis and diagnosis after review were compared to assess
pathologic recognition of TRS. Pathologic assessment included identification of
vas deferens, epididymis, dystrophic calcification, hemosiderin, dominant vein,
pampiniform plexus-like vessels, and vascularized fibrous nodule formation. At
minimum, the presence of a vascularized fibrous nodule (VFN) with calcification
or hemosiderin or VFN with cord element(s) was required for diagnosis. SETTING
AND PARTICIPANTS: Medical records and pathologic specimens of patients undergoing
surgery for cryptorchidism or with specimens reviewed at a medium-sized
university hospital were analyzed. RESULTS: The original diagnosis in 3 (23%) of
13 cases was that of TRS. On secondary review, 11 (85%) of 13 cases showed
features consistent with TRS. The diagnoses both before and after review showed a
concurrence of 23% (3/13 cases). Two (15%) of 13 cases were correctly recognized
and diagnosed as TRS at primary review; 1 case originally thought to represent
TRS was not confirmed. Pathologic features correlated well with those reported in
the literature. Among all 13 cases, the 11 confirmed TRS cases showed VFN in 11
(85%), intranodular calcification in 8 (62%), intranodular hemosiderin in 9
(69%), vas deferens in 9 (69%), epididymal structures in 5 (38%), and a dominant
venous structure in 11 (85%). The average size of the VFN was 1.1 cm. CONCLUSION:
A urologic and pediatric surgical problem, TRS may be unrecognized by many
practicing pathologists. In the typical situation in which a blind ending
spermatic cord is submitted for tissue analysis, characterization of such cases
as consistent with regressed testis is desirable and achievable in a high
percentage of cases. Pathologists may play a pivotal role in management of these
patients since histologic confirmation of the testis as regressed reassures the
surgeon and the family of the correctness of diagnosis and can eliminate the
necessity for further intervention.
PMID- 10782150
TI - Liposarcoma of the pleural cavity: clinical and pathologic features of 4 cases
with a review of the literature.
AB - BACKGROUND: Primary liposarcomas of the pleura are extremely rare malignancies,
and relatively few reports appear in the world literature. DESIGN: We compiled a
small series of 4 cases of primary pleural liposarcoma from the files of the
Armed Forces Institute of Pathology (Washington, DC) and compared the
histopathologic and clinical features of these 4 cases with those of 9 previously
published cases. RESULTS: Our investigation included the case studies of 9 men
and 4 women, aged 19 to 80 years (average, 49 years). Histologic subtypes in the
9 cases with available information included 5 myxoid liposarcomas, 1 well
differentiated liposarcoma, and 3 liposarcomas with mixtures of histologic types.
Surgical resection with or without chemotherapy appeared to be the most common
form of treatment, although radiation therapy was used in some cases and seemed
beneficial. Survival information was available for 11 cases; 4 patients died of
disease at 7, 9, 12, and 19 months; 1 died of heart failure 2 days after
presentation; 1 died of unknown causes 16 months after presentation; and 3
patients were alive without tumor at 5, 16, and 66 months after diagnosis. One
patient had local recurrence at 2 years. A second surgical resection in this
patient failed, and he died of disease 9 years after initial presentation. A
second patient experienced recurrence at 4 years and was free of disease 4 years
after the second surgical resection. CONCLUSIONS: Primary pleural liposarcomas
occur predominantly in older men, and the myxoid histologic subtype is the most
common. Radiographic or surgical evaluation is important to distinguish primary
pleural liposarcoma from chest wall or mediastinal sarcomas, as well as
metastases from other sites. Although further investigation is needed, evidence
from the cases reviewed here indicates that surgical resection with adjuvant
radiation therapy may benefit patients with primary pleural liposarcoma.
PMID- 10782151
TI - Immunoperoxidase detection of CD10 in Precursor T-lymphoblastic
lymphoma/leukemia: a clinicopathologic study of 24 cases.
AB - CONTEXT: CD10 was originally reported in non-T-cell lymphoblastic
lymphomas/leukemias. It has since been identified, however, in a minority of
cases of T-lympho-blastic lymphoma/leukemia and other hematopoietic and
nonhematopoietic entities. The usual method for the detection of CD10 previously
required fresh tissue. A new antibody for CD10 (56C6) in paraffin embedded tissue
sections, however, has recently become available. OBJECTIVE: To study the
expression of CD10 in paraffin sections of T-lymphoblastic lymphoma/leukemia
using monoclonal antibody 56C6. DESIGN: Twenty-four cases of T-lymphoblastic
lymphoma/leukemia in various anatomic sites were studied. Immunohistochemical
analysis with CD10 and a panel of other hematolymphoid antibodies was performed
in all 24 cases. Gene rearrangement studies for the T-cell receptor by the
polymerase chain reaction were performed in 18 of 24 cases. RESULTS: All cases
were positive with at least 2 T-cell markers. In 15 (63%) of 24 cases CD10 was
positive. T-cell receptor gene rearrangement was detected in 10 of 18 cases.
CONCLUSIONS: Immunodetection of CD10 in T-lympho-blastic lymphoma/leukemia using
monoclonal antibody 56C6 is common. This finding is useful in the evaluation of T
cell neoplasms.
PMID- 10782152
TI - Granular cell traumatic neuroma: a lesion occurring in mastectomy scars.
AB - BACKGROUND: Granular cell changes can be observed in a variety of benign and
malignant tumors, and are seen more commonly in granular cell tumors, which in
about 5% of cases develop in the breast. Granular cells also have been observed
in sites of previous trauma, such as surgery, and are found to be inflammatory
reactions of histiocytic origin. METHODS AND RESULTS: We investigated,
morphologically and immunohistochemically, 2 granular cell lesions occurring in
mastectomy scars after surgery for carcinoma. Both lesions were composed of
strands and nests of large granular cells, haphazardly set in a background of
fibrous tissue, with sparse inflammatory infiltrates. Several tortuous
hypertrophic nerve bundles were also embedded in the fibrous tissue. A few of
these nerve bundles showed degenerative changes and contained granular cells.
Immunohistochemically, granular cells were positive for S100 protein, neuron
specific enolase, vimentin, and CD68 antigen. CONCLUSIONS: We consider these
proliferative lesions of peripheral nerves to have the features of both granular
cell tumor and traumatic neuroma. These cases indicate that traumatic neuroma can
undergo extensive granular cell changes and constitute a previously unrecognized
entity, which we provisionally label granular cell traumatic neuroma. Granular
cell traumatic neuroma has to be taken into consideration when evaluating lesions
occurring at mastectomy scars and should be differentiated from malignant tumors
with granular cells, such as apocrine carcinoma and alveolar soft part sarcoma.
PMID- 10782153
TI - Pyogenic spondylodiskitis: a radiologic/pathologic and culture correlation study.
AB - BACKGROUND: Intervertebral disk tissue is resistant to hematogenous infection
because of its avascularity. However, spondylodiskitis is being diagnosed with
increasing frequency because of advancement in magnetic resonance imaging
technology. There is a dearth of information regarding the bacteriology,
histomorphologic features, and radiopathologic correlation of spondylodiskitis.
DESIGN: The study population consisted of 20 patients diagnosed as having
spondylodiskitis by magnetic resonance imaging with and without gadolinium 67
enhancement and bone scans with technetium Tc 99m or gallium citrate Ga 67.
Twenty-seven biopsy and debridement specimens were obtained from these patients.
The specimens were cultured for microorganisms and also processed for
histopathologic testing. Tissue sections were examined with hematoxylin-eosin and
stains for infectious agents (Gomori's methenamine-silver, Gram, and Ziehl
Neelsen stains). RESULTS: Where intervertebral disk tissue was present (23 of 27
cases), the morphologic changes included vascularization (with or without
granulation tissue), myxoid degeneration, and necrosis. Chronic osteomyelitis was
present in all 27 specimens and was associated with acute osteomyelitis in 7
cases (25%). Twenty-one of 27 cases had positive culture results (mostly pyogenic
bacteria), but special stains revealed microorganisms in sections of the disk in
only 4 cases (3 cases with gram-positive cocci and 1 with yeast consistent with
Blastomyces). Florid acute inflammation was present in all the 4 cases.
CONCLUSION: Histopathologic features of acute spondylodiskitis include vascular
proliferation, myxoid degeneration, and necrosis of the disk tissue with adjacent
chronic osteomyelitis. Acute inflammation is variable and when florid is usually
associated with identifiable organisms on histologic examination. At biopsy,
tissue should be submitted for culture, since culture has a high sensitivity and
specificity for detecting the etiologic organism.
PMID- 10782154
TI - Pulmonary vasculopathy in idiopathic spontaneous pneumothorax in young subjects.
AB - BACKGROUND: We have encountered instances where young subjects with idiopathic
spontaneous pneumothorax have been needlessly referred for investigation of
pulmonary hypertension because surgical pathologists have misinterpreted the
significance of medial hypertrophy and intimal fibrosis of muscular pulmonary
arteries in lung resection specimens. METHODS: We reviewed 20 cases of idiopathic
spontaneous pneumothorax and determined the prevalence and severity of medial and
intimal lesions in the pulmonary arteries and pulmonary veins. We correlated the
vascular changes with inflammation and fibrosis in the lung. RESULTS: Pulmonary
artery medial hypertrophy was seen in 15% of cases, pulmonary artery intimal
fibrosis in 90% of cases, and pulmonary vein intimal fibrosis in 80% of cases. In
95% of cases, the lung showed some fibrosis and chronic inflammation. There was a
significant positive correlation between pulmonary artery medial thickness and
lung fibrosis and inflammation scores. CONCLUSIONS: Pulmonary artery medial
hypertrophy and intimal fibrosis of pulmonary arteries and pulmonary veins are
commonly seen in resected lung tissue from patients with idiopathic spontaneous
pneumothorax. The vascular lesions are probably secondary to chronic inflammation
and fibrosis in the adjacent lung. They are not clinically significant and do not
represent hypertensive pulmonary vascular disease.
PMID- 10782155
TI - Human papillomavirus type, proliferative activity, and p53: potential markers of
aggressive papillomatosis.
AB - CONTEXT: The predictive value of nuclear proliferation antigen (Ki-67), tumor
suppressor gene product p53, and human papillomavirus type has not been evaluated
for outcome of laryngeal papilloma. OBJECTIVE: This study was designed to
determine whether immunohistochemical analysis of Ki-67 and p53 and human
papillomavirus typing by polymerase chain reaction are able to identify patients
with a more aggressive course of laryngeal papillomatosis. DESIGN:
Immunohistochemistry and polymerase chain reaction were performed on archival,
paraffin-embedded, laryngeal papillomatosis biopsy specimens at the time of
diagnosis, at an intermediate time during treatment, and at the last procedure
available. Staining indexes for Ki-67 and p53 were determined, and human
papillomavirus type was analyzed for all biopsies. PATIENTS: Twelve patients with
recurrent laryngeal papillomatosis for at least 5 years were selected from
patients treated at our institution during the last 20 years. MAIN OUTCOME
MEASURES: Separate analyses were conducted comparing average Ki-67 and p53
indexes against disease outcome, viral type, or average number of procedures per
year. Associations were analyzed between virus type, average number of procedures
per year, outcome, and histology. RESULTS: No statistically significant
associations were noted in Ki-67 or p53 indexes and outcome. Weak associations
were noted for p53 indexes and procedures per year and virus type. Weak
associations also were noted between virus type and development of neoplasia.
CONCLUSIONS: Our observations suggest that human papillomavirus typing may be
helpful in identifying patients with aggressive recurrent laryngeal
papillomatosis. The weak association between p53 indexes and procedures per year
and virus type may have some predictive value in identifying aggressive lesions.
PMID- 10782156
TI - Retrorectal cystic hamartoma: report of 5 cases with malignancy arising in 2.
AB - BACKGROUND: Retrorectal cystic hamartomas, or tailgut cysts, are rare congenital
lesions that typically present as presacral masses. These lesions are frequently
clinically unrecognized and misdiagnosed. Malignant change is extremely rare.
Only 10 additional cases with associated malignancy were recovered from the
literature. We describe the clinicopathologic features of 5 cases, including 2
cases with malignant transformation. RESULTS: All patients were women (age range,
36-69 years). The most common symptoms were pain with defecation and rectal
bleeding. One patient was asymptomatic. All lesions presented as multicystic
presacral masses and all were surgically resected. The lesions varied in size
from approximately 2 to 12 cm (average, 9.5 cm) and overall had similar histology
composed of a variety of epithelial linings (stratified squamous, transitional,
and simple or ciliated pseudostratified columnar). Skin adnexa, neural elements,
and heterologous mesenchymal tissue, discriminators between retrorectal cystic
hamartoma and teratoma, were not identified. Arising in association with the
cysts was a focus of adenocarcinoma in one case and a neuroendocrine carcinoma in
another. CONCLUSIONS: The clinical diagnoses in our cases were often delayed,
which in part may be due to unfamiliarity with this entity. The main diagnostic
difficulty is distinction from presacral mature cystic teratomas and rectal
duplication cysts. Tailgut cysts require complete surgical excisions to prevent
future recurrences and to preclude possible malignant transformation. Meticulous
gross examination and adequate sampling are important to document the exact
nature of these cysts and to rule out possible coexisting malignancies, which may
be focal.
PMID- 10782157
TI - Acquired hemophilia in patients with hematologic malignancies.
AB - OBJECTIVES: To evaluate the occurrence of acquired hemophilia in patients with
hematologic malignancies and to assess their response to treatment. DESIGN: Data
on 8 patients with hematologic neoplastic disorders and inhibitor against factor
VIII were analyzed retrospectively. SETTING: Three large tertiary-care centers.
RESULTS: All 8 patients presented with spontaneous or posttraumatic hemorrhages.
The mean inhibitor titer at the time of diagnosis was 79 Bethesda units (BU), and
residual factor VIII activity was detectable in 3 patients. The inhibitor
disappeared in 5 patients after a mean of 92 days, but persisted in the 3 other
patients. The patients who achieved complete resolution of their circulating
anticoagulant had lower mean inhibitor titers at the time of diagnosis than those
who had persistent inhibitor (27 BU vs. 167 BU, respectively). Two patients died
as a result of major hemorrhages that did not respond to treatment. CONCLUSIONS:
Antibodies against factor VIII may be responsible for some bleeding episodes in
patients with lymphoid or myeloid malignancies. Acquired hemophilia in this
setting should be differentiated from other causes of bleeding because the
approach to treatment is different. No conclusion can be drawn regarding the
association between the activity of the underlying illness and the inhibitor
titer, although it appears that at least in some patients such a relationship may
exist. The underlying pathogenetic mechanisms responsible for the production of
autoantibodies against factor VIII remain unclear, but we provide a few
explanations in this article.
PMID- 10782158
TI - Non-hodgkin malignant lymphoma with tissue neutrophilia: a report of 3 cases.
AB - CONTEXT: Neutrophils, in the absence of necrosis, are uncommon in non-Hodgkin
malignant lymphoma. Recently, a neutrophil-rich type of Ki-1 (CD30)-positive,
anaplastic large cell lymphoma was described. OBJECTIVES: We report 3 cases of
nonanaplastic large cell lymphoma with an abundance of tissue neutrophils; 2
cases were associated with breast carcinoma and possible infection. RESULTS:
Peripheral blood neutrophilia was noted in only 1 of these 3 patients.
Neutrophilia in the lymph nodes occurred in either a sinusoidal or interstitial
pattern. Multiple biopsies were available for review in 2 patients; however,
tissue neutrophilia was present in only 1 biopsy each. CONCLUSION: These findings
suggest that nonanaplastic large cell lymphoma-related tissue neutrophilia is a
transient phenomenon.
PMID- 10782159
TI - Declining autopsy rate in a French hospital: physician's attitudes to the autopsy
and use of autopsy material in research publications.
AB - CONTEXT: Autopsy rates have been declining throughout the world, although
preservation of the autopsy is considered a fundamental principle of medical
care. In France, the 1994 bioethics law requires physicians to inform relatives
before performing an autopsy. OBJECTIVE: To analyze the following factors that
potentially influence hospital autopsy rates: legal constraints, autopsy
reporting times, opinions of physicians requesting autopsies and pathologists
regarding the usefulness of autopsy in patient care, and use of autopsy material
in research publications. DESIGN: Record of the annual numbers of deaths and
autopsies during a 10-year period (1988-1997). Record of the delays for
transmission of final autopsy report to the requesting physician. Questionnaire
analyzing the possible factors influencing autopsy rate. Categorization of
articles published by pathologists according to the use of autopsy material.
SETTING: A 1000-bed, university teaching hospital in the Paris, France, area.
PARTICIPANTS: Questionnaire addressed to physicians, head nurses, and mortuary
staff. RESULTS: A total of 1454 autopsies were reviewed. The autopsy rate
declined from 15.4% in 1988 to 3.7% in 1997. This decline was marked after 1994
and tended to be slower for neurologic indications than for other indications.
The final report had not been communicated within 180 days in 620 (42.6%) of 1454
autopsies. Fifty-five of 105 respondents considered that the bioethics law was
one cause of the recent decrease of autopsy rate. Considering the contribution of
autopsy to medical research, 94 (81%) of 116 articles dealing with central
nervous system but only 28 (6%) of 464 articles dealing with other organs used
autopsy-derived material. CONCLUSIONS: The 1994 bioethics law seems to contribute
to the decline of autopsy. Inadequate delays for communicating autopsy results
are frequent. Except for neuropathologists, autopsy is a minor source of research
material.
PMID- 10782160
TI - Lymphoepithelioma-like carcinoma of the uterine cervix: a case report studied by
in situ hybridization and polymerase chain reaction for Epstein-Barr virus.
AB - Lymphoepithelioma-like carcinomas have been reported outside the nasopharynx in
many sites, including the uterine cervix. The association with the Epstein-Barr
virus in the latter site is still controversial. To date, Epstein-Barr virus
genome has only been demonstrated in Asian patients. We report a case of
lymphoepithelioma-like carcinoma of the uterine cervix in a white woman in whom
the Epstein-Barr virus infection was tested for by in situ hybridization and
polymerase chain reaction. The results of both techniques were negative. Our case
and a review of the literature support the contention that cervical
lymphoepithelioma-like carcinoma is not associated with Epstein-Barr virus
infection in non-Asian patients.
PMID- 10782161
TI - Blastic transformation of splenic marginal zone B-cell lymphoma.
AB - To our knowledge, blastic transformation of splenic marginal zone lymphoma, a
recently characterized low-grade lymphoproliferative disorder, has not been
reported previously. In this regard, we report the unique case of a 70-year-old
woman whose untreated splenic marginal zone lymphoma underwent blastic
transformation 3 years after diagnosis. Her hematologic medical history started
in 1988 as thrombocytopenia refractory to steroids associated with atypical
lymphoid infiltrate in the bone marrow. She underwent splenectomy in 1989, which
revealed splenic marginal zone lymphoma. One year later, the patient developed
lymphadenopathy noted in the chest, axillary, abdominal, and retroperitoneal
lymph nodes. Because she was asymptomatic, treatment was limited to a
conservative supportive regimen. The nodal lymphoma cells had features associated
with marginal zone lymphoma and expressed B-cell monotypic kappa light chain. She
was readmitted for the last time 2 years later with findings of 16% blasts in the
peripheral blood and massive infiltration of the bone marrow by large blastoid
cells. The blasts showed dispersed chromatin and prominent nucleoli, and
possessed a moderate amount of clear cytoplasm. The blasts, like the previous
nodal and splenic lymphomas, had a CD20-, CD19-, IgM-positive phenotype, but
lacked reactivity for CD5, CD10, and CD23. The patient displayed clinical
remission after treatment with vincristine and prednisone, but died of aspiration
pneumonia 1 month later. These observations suggest that, similar to the other
low-grade lymphoproliferative disorders, an untreated splenic marginal zone
lymphoma may undergo high-grade blastic transformation.
PMID- 10782162
TI - Early peripheral lymph node involvement of human herpesvirus 8-associated, body
cavity-based lymphoma in a human immunodeficiency virus-negative patient.
AB - Human herpesvirus 8 (HHV-8), or Kaposi sarcoma-associated herpesvirus, is a gamma
herpesvirus first detected in a specimen of Kaposi sarcoma from a human
immunodeficiency virus (HIV)-positive patient. Human herpesvirus 8 is also found
in an unusual clinicopathologic form of body cavity-based B-cell lymphoma, which
has been named primary effusion lymphoma (PEL) and occurs primarily in HIV
positive patients. PEL is characterized by the formation of lymphomatous
effusions, without obvious lymphadenopathy, tumor masses, or bone marrow
involvement. Only a few cases of PEL in HIV-seronegative patients have been
reported. We describe a case of an HHV-8-associated lymphoma, with ascites,
pleural effusion, and axillary lymphadenopathy in an HIV-negative patient. The
patient was a 68-year-old Jewish man of North African extraction, with a previous
history of coronary bypass surgery and multiple blood transfusions. The pleural
fluid contained large atypical lymphoid cells and was suggestive of lymphoma but
could not provide a conclusive diagnosis of PEL. The lymph node contained groups
of large anaplastic lymphoid cells. Polymerase chain reaction for HHV-8 performed
on the lymph node specimen was positive, establishing the diagnosis of PEL.
Polymerase chain reaction for Epstein-Barr virus was negative. Results of a
gallium scan were normal. The patient did not respond to combination chemotherapy
with cyclophosphamide, doxorubicin, vincristine sulfate, and prednisone and
progressively developed, massive intra-abdominal solid tumor formation. To our
knowledge, this is the first report of a case of PEL that demonstrates peripheral
lymph node involvement at diagnosis and the first report of PEL in an Israeli
patient.
PMID- 10782163
TI - Solitary fibrous tumor of the orbit with a t(9;22)(q31;p13).
AB - Solitary fibrous tumors are well-described neoplasms found predominantly in the
subpleural region but also in many other body sites. They generally behave in a
benign fashion, although a few cases that exhibit a malignant course have been
reported. Genetic information on solitary fibrous tumors is sparse. This case
illustrates a previously unreported finding of a tumor-specific t(9;22)(q31;p13)
in a solitary fibrous tumor of the orbit of a 58-year-old man.
PMID- 10782164
TI - Diagnostic value of immunocytochemistry in leptomeningeal tumor dissemination.
AB - Differentiating chronic aseptic meningitis from leptomeningeal carcinomatosis or
gliomatosis can be difficult, particularly when the differentiation is based
solely on routine cytologic examination. The diagnosis of cerebrospinal fluid
tumor dissemination in at-risk patients requires cytologic examination of
cerebrospinal fluid and radiography of the leptomeninges. Routine cytologic
examination alone has proven less than desirable, in most instances providing
confirmation in as little as 50% of cases in the first lumbar puncture. This
percentage increases to 85% to 90% after multiple lumbar punctures. We
retrospectively reviewed 2 cases of leptomeningeal dissemination (one
gliomatosis, the other carcinomatosis) with initial false-negative test results.
However, after further examination of the cerebrospinal fluid by selected battery
of immunocytochemical stains, both cases were identified as positive for
malignancy (ie, false negatives). Immunocytochemistry can be useful in
distinguishing chronic aseptic meningitis from leptomeningeal carcinomatosis or
gliomatosis in patients at risk or when abnormal cells are seen on routine
cerebrospinal fluid cytologic examination.
PMID- 10782165
TI - Primary meningeal rhabdomyosarcoma in a child with hypomelanosis of Ito.
AB - Intracranial rhabdomyosarcomas are rare neoplasms, and those thought to be
primary meningeal tumors are even more rare. Hypomelanosis of Ito is a
neurocutaneous disorder believed to involve a defect in cells of neural crest
origin. We report the case of a 15-month-old boy with hypomelanosis of Ito who
developed a primary meningeal rhabdomyosarcoma. The patient initially presented
with hydrocephalus and 2 months later developed neurologic signs localizing to
the spinal cord. Radiologic studies revealed widespread leptomeningeal
enhancement with compression of the spinal cord at C5-C7. A brain biopsy revealed
a tumor diffusely involving the meninges. Microscopically, the tumor was composed
of rhabdomyoblasts, many of which showed prominent cross-striations on routine
hematoxylin-eosin staining. To the best of our knowledge, this is the first
reported case of meningeal rhabdomyosarcoma in a patient with hypomelanosis of
Ito and the fourth reported case of a primary meningeal rhabdomyosarcoma reported
in the world literature.
PMID- 10782166
TI - Unilocular retroperitoneal cyst of mesothelial origin presenting as a renal mass.
AB - We report the first 2 cases, to our knowledge, of retroperitoneal cysts with
features of mesothelial differentiation that clinically mimic renal masses. The
first lesion occurred in a 71-year-old man who presented with flank pain.
Ultrasound and magnetic resonance imaging studies showed a unilocular cystic
structure arising from the upper pole of the left kidney. The second lesion was
in a 44-year-old woman who presented with left flank pain. Imaging studies
revealed an 8-cm hemorrhagic cyst at the lower pole of the left kidney.
Histologic examination of the nephrectomy specimens in each case revealed a
unilocular cyst with intracystic and pericystic hemorrhage. In each case, the
cyst was lined by a single layer of cells with ample eosinophilic cytoplasm and
benign nuclear features without mucinous or mullerian differentiation.
Histochemical staining showed Alcian blue positivity on the cell surface, which
was sensitive to hyaluronidase digestion. Intracytoplasmic mucin, however, was
not detected. Immunostaining showed that the cyst lining cells were positive for
keratin, vimentin, HBME-1, WT1, and thrombomodulin but negative for
carcinoembryonic antigen, B72.3, Leu-M1, and BerEP4. The first case was positive
for calretinin, whereas the second was negative. These findings support the
mesothelial nature of the cysts.
PMID- 10782167
TI - Coexisting thymic and gastric lymphomas of mucosa-associated lymphoid tissues in
a patient with Sjogren syndrome.
AB - Lymphomas of mucosa-associated lymphoid tissues (MALTomas) arising from the
thymus are extremely rare. In this case report, we describe a 36-year-old woman
with an 11-year history of Sjogren syndrome who was found to have a thymic
MALToma coexisting with a gastric MALToma. Both tumors shared similar histologic
features, showing clusters of centrocytic-like B cells, lymphoepithelial lesions,
and prominent plasmacytic differentiation. They also showed the following
identical immunohistochemical features: CD20(+), IgA/lambda(+), CD5(-), and CD43(
). Molecular studies using polymerase chain reaction methods revealed monoclonal
gene rearrangement of the immunoglobulin heavy chain in the gastric MALToma, but
not in the thymic MALToma. The possible pathogenesis of this unusual case is
discussed.
PMID- 10782168
TI - Staining method to demonstrate urate crystals in formalin-fixed, paraffin
embedded tissue sections.
PMID- 10782169
TI - Evaluation of a combined acid-fast-trichrome stain for detection of microsporidia
and Cryptosporidium parvum.
PMID- 10782172
TI - Tumors of the lymph nodes and spleen (CD-ROM)
PMID- 10782173
TI - Tumors of the lower respiratory tract (CD-ROM)
PMID- 10782174
TI - Pathologic quiz case: a large cystic thigh mass in a 10-year-old boy.
PMID- 10782175
TI - Pathologic quiz case: a testicular mass in a 19-year-old man.
PMID- 10782176
TI - Pathologic quiz case: a 46-year-old woman with a brain tumor.
PMID- 10782177
TI - Efficacy and safety of patient-controlled analgesia for morbidly obese patients
following gastric bypass surgery.
AB - BACKGROUND: Adequate postoperative pain control is important to reduce potential
cardiopulmonary complications. It is often difficult to determine dosages of
narcotics for morbidly obese patients following Roux-en-Y gastric bypass (RYGBP)
due to respiratory depression. Individualization of analgesic therapy, patient
controlled analgesia (PCA), can provide optimal dosage for pain control and
minimize the side-effects. METHOD: 25 morbidly obese patients who received PCA
with morphine sulfate following RYGBP. PCA settings we re as follows: morphine,
20 microg/kg of ideal body weight, 10-minute lock out interval and 80 % of a
calculated amount for a 4-hour limit. W e measured arterial blood gas, heart
rate, mean arterial pressure, arterial oxygen saturation, respiratory rate,
opioid amount, patient satisfaction, visual analog pain scale (VAS), and the
incidence of nausea, vomiting, pruritus and sedation. RESULTS: Average morphine
usage was 44.2+/-28.7 mg during the day of surgery (DOS); 49.1+/-27.4 mg during
POD (postoperative day) #1; and 36.6+/-22.8 mg during POD#2 (p < 0.01). 24
patients were satisfied with their pain control on POD#1. VAS was 5.4+/-2.1 on
the day of surgery, but remained below 4 thereafter. Arterial oxygen saturation
and vital signs were maintained without significant changes. 5 patients
experienced mild sedation on the day of surgery and 3 patients experienced mild
sedation on POD#1. 1 patient experienced nausea and vomiting and 4 patients had
pruritus; however, none required treatment. CONCLUSION: PCA is safe and effective
for morbidly obese patients following RYGBP.
PMID- 10782178
TI - Variables affecting BMI evolution at 2 and 5 years after vertical banded
gastroplasty.
AB - BACKGROUND: Vertical banded gastroplasty (VBG) has been found to result in
significant reduction in body mass index (BMI) during the first postoperative
year. We investigated the impact of some intrinsic and extrinsic factors on long
term BMI evolution in morbidly obese patients who underwent VBG, with the aim of
establishing a long-term weight-loss prognosis. METHODS: 67 consecutive morbidly
obese patients who underwent VBG were followed for 2 years; of these, 34 were
followed 3 more years, for a total follow-up of 5 years. BMI was monitored and
correlated with demographic (preoperative BMI, obese relatives, age and gender)
and lifestyle variables (physical activity, habitual dietary transgression and
occupational status). RESULTS: Global BMI fell from 47.5 at the time of the
intervention to 32.1 when patients were examined 12 months after surgery. From
the second year, an upward trend was observed, and at 5 years, mean BMI was above
35, considered in the high-risk range. Modifiable variables affecting lifestyle
have shown significantly favorable effects on BMI evolution. Among intrinsic
variables, BMI before surgery and obese parents also affect long-term evolution.
CONCLUSION: Different variables should be considered in order to establish a long
term weight-loss prognosis for each patient, thus making it possible to act more
specifically on modifiable variables.
PMID- 10782179
TI - Gastroscopic band removal after intragastric migration of adjustable gastric
band: a new minimal invasive technique.
AB - BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) is the most used
procedure for bariatric surgery in Europe. Although a low complication rate is
reported, band migration within the first 2 years after LAGB is still observed in
nearly 5% of cases, requiring operative band removal. To avoid increased risk of
complications due to laparotomy, we propose a minimally invasive technique for
this purpose. METHODS: We performed this operation in five patients who suffered
from band migration after LAGB (1.9% in our series of 211 patients, one patient
was operated elsewhere). The described method consists of gastroscopic band and
tube removal, combined with removal of the port under local anesthesia. RESULTS:
The described procedure was developed in the endoscopy unit without additional
equipment. The mean operating-time ranged from 65 to 180 minutes (mean 135
minutes). No perioperative complication were observed. In-patient treatment was
necessary for 4 days. CONCLUSIONS: A novel technique for minimally invasive band
removal after adjustable gastric band migration is described, offering the
patient a low-risk procedure and a better chance for further laparoscopic
approaches.
PMID- 10782180
TI - Adjustable gastric banding: 5-year experience.
AB - BACKGROUND: From 1993 to 1999, 172 patients underwent adjustable silicone gastric
banding (ASGB) or laparoscopic adjustable silicone gastric banding (LASGB). In
109 patients the adjustable band was placed via laparoscopy; in the other
patients it was placed via laparotomy (prelaparoscopic era, conversions from
other bariatric operations, conversions for laparoscopic failure). The conversion
rate from laparoscopy to laparotomy was 9.3%, occurring in the early part of our
experience. METHODS: Mean age was 37.9 years, weight 135 +/- 14.8 kg (82-218) and
BMI 46.3 +/- 5.4 (35.1-69.5). All patients had multiple band adjustments,
temporary antisecretive, electrolyte and vitamin therapy, and follow-up per
routine. RESULTS: Weight loss at 3 years was 30.2%; mean percent loss of excess
weight was 62.5%. There was no mortality. The most important technical
complications were: gastric pouch dilatation that required band replacement or
removal (5.8 %); mild gastric pouch dilatation reversible with adequate dietary
and pharmacological treatment (4.6%); intraoperative gastric perforation (2.3%);
band migration (0.6%). The band was removed in 2.3%, with conversion to another
bariatric procedure in 1.1%. CONCLUSIONS: Results have been satisfactory thus
far.
PMID- 10782181
TI - Facilitated vertical gastric pouch construction for gastric bypass.
AB - BACKGROUND: Efforts to simplify and reduce surgical risk of gastric pouch
construction in super obese patients have led to technical changes which are
described. METHODS: Operative technique of vertical gastric pouch construction
and hand-sewn Roux gastrojejunostomy are described. RESULTS: 171 patients with
average BMI = 55 have undergone gastric bypass with the modified technique, a
majority with double stapling of the gastric pouch. Staple-line dehiscence is
reduced and operative morbidity is limited. CONCLUSIONS: Technical changes
described have shortened operative time, reduced intraoperative frustrations, and
produced limited postoperative morbidity.
PMID- 10782182
TI - Failure of biliopancreatic diversion in Prader-Willi syndrome.
AB - BACKGROUND: Prader-Willi syndrome (PWS) is the most common genetic obesity.
Excessive weight gain follows failure-to-thrive in early infancy; in adolescents
and young adults, excess body weight can exceed 100%. The hyperphagia associated
with PWS is responsible for the early mortality. Dietary restriction, alone or
combined with anorexic drugs, are ineffective to induce a permanent weight loss.
Thus, surgical treatment of morbid obesity in PWS has been attempted, but gastric
restrictive operations are unable to produce stable weight loss. In a small
number of patients, favorable results have been reported with biliopancreatic
diversion (BPD). CASE REPORT: A 24-year-old woman with PWS, Pickwickian, at age
21 weighed 80 kg (BMI= 50) and underwent BPD. RESULTS: 3 years after the BPD she
regained 21 of the 26 kg lost; somnolence and respiratory difficulties were the
same as before surgery. The patient now presents severe reduction of bone mass
density, hypochromic anemia, hypoproteinemia, and diarrhea associated with
eating. CONCLUSION: The regain of weight following BPD suggests that this
procedure alone is not adequate for long-term control of obesity in PWS.
PMID- 10782183
TI - BPD and prader willi syndrome
PMID- 10782184
TI - Experience with the Roux-en-Y gastric bypass, and commentary on current trends.
PMID- 10782185
TI - Transactions in a support group meeting: a case study.
AB - Following bariatric surgery, the inclusion of a support group as part of the
treatment plan makes after-care easier and more efficient for the patients, as
well as for the physicians. The following is presented for the education of the
medical community. It represents one exemplary session which incorporates the
elements necessary for effective after-care: 1. Encouragement for compliance and
praise for success. 2. Education about life-after-surgery, including nutrition,
exercise and dieting techniques. 3. Identification of problems. 4. Identification
and development of new kinds of self-nurturing. 5. Participation in a forum where
others really "understand" the challenges and difficulties associated with
"change," even when the change is for the better. 6. Creation of a "safe harbor"
where patients can bring spouses, parents and significant others so that they may
also understand, encourage continuing success, and recognize their own personal
issues related to the major changes that they are also experiencing with their
loved one. 7. Opportunity for curious potential patients in the community to come
and learn from the "experts" in an atmosphere of true caring and concern.
PMID- 10782187
TI - Time trends analysis of hearing loss: an alternative approach to evaluating
hearing loss prevention programs.
AB - Two general approaches for evaluating the performance of hearing loss prevention
programs (HLPPs) are described in the literature: (1) a comparison of the rate of
hearing loss in an HLPP with a reference population and (2) a comparison of
audiometric variability or annual incidence of hearing loss with an established
set of criteria that rank HLPP performance on a graded scale. This article
discusses a third method, time trends analysis, which assesses patterns in
hearing loss over time. Patterns may reflect program improvement (decreased
hearing loss incidence over time), deterioration (a pattern of increased
incidence), or stasis (unchanged incidence). To demonstrate this method, a time
trends analysis was conducted on a population of 44,547 industrial workers.
Subjects were divided into 11 subgroups based on year of enrollment in the HLPP
(1980-1990) and followed retrospectively for 3 years to determine the incidence
of hearing loss. Hazard ratios (HRs) were estimated for each subgroup by gender
using the Cox Proportional Hazards model and adjusting for age, race, and hearing
threshold at enrollment in the HLPP. For women, plots of adjusted HRs against
enrollment years produced a statistically significant (p < 0.05) quadratic trend
of an initial increase in hearing loss, followed by decreasing incidence over
time. For men, there was a statistically significant linear trend of decreasing
hearing loss over time. The downward trend, particularly during the late 1980s,
indicates improved HLPP performance during the latter portion of the decade. Time
trends analysis can be a valuable tool for assessing HLPP performance for those
with access to follow-up data and ability to work with statistical models.
PMID- 10782186
TI - Lung fibrosis reported in a dental technician.
PMID- 10782188
TI - Construction and evaluation of an aerosol generating apparatus for combustion
products from polyurethane foam.
AB - A system has been constructed and evaluated for generating aerosols from
combustion or pyrolysis of various cross-linked polymers. The system consists of
an aerosol generator and an aerosol chamber with a sampling compartment designed
for various samplers and sampling probes. A geared electric motor assembly is
used to lower a polymer strip into the controlled atmosphere of a quartz-lined
furnace. The polymer used in this investigation was a polyurethane foam (PUF)
based on toluene diisocyanate (TDI). Combustion of the PUF was conducted in
filtered air at a temperature of 300 degrees C. The particle number concentration
of the generated aerosol was measured by light scattering in the particle size
range from 0.1 micron to greater than 5 microns. Air samples were collected
periodically in impinger flasks using dibutylamine (DBA) in toluene as
derivatization reagent. The TDI-DBA derivatives from the impinger samples were
analyzed with high performance liquid chromatography. The aerosol generating
system was found to generate a stable, reproducible, and predictable
concentration of particles and TDI monomer. Three partial least squares models
were created to evaluate the generator. The investigated responses were the TDI
concentration, the particle number concentration, and the stability of the
particle number concentration during the generating process. The factor with most
impact on the concentrations of the generated aerosol was found to be the
interaction between linear feeding rate of the polymer strip and the flow rate of
combustion gas. For stability the linear feeding rate was the most important.
PMID- 10782189
TI - The impact of work environment, utility, and sampling design on occupational
magnetic field exposure summaries.
AB - Most recent epidemiologic studies investigating the potential health effects of
occupational magnetic field (MF) exposure have relied on MF measurement data
linked to job titles. These measurements are summarized by occupational
categories, which represent similar groups of job titles. However, job titles
alone explain only a small proportion of exposure variability. A comprehensive MF
occupational exposure database was used to (1) develop summary job-specific
estimates of magnetic field exposure, (2) evaluate the impact of incorporating
work environment data to improve electric and magnetic field exposure assessment,
and (3) evaluate the use of random versus nonrandom sampling when estimating mean
MF exposure levels by occupational categories. Uniform classification systems
were developed for occupational and work environment data. A factorial design was
used to summarize and calculate arithmetic means and 95% confidence intervals for
occupational MF data, assuming that the total variation in MF exposure resulted
from variation in occupation, work environment, utility, worker, and day.
Occupation-specific means varied across different work environments, particularly
for craft workers. Although within-worker and between-worker variability account
for a large proportion (over 50%) of exposure variation, work environment (24%)
accounted for more exposure variability than occupation (4.9%) or utility (15%).
Some differences were observed when results were compared from surveys that used
random and nonrandom sampling; however, these differences were not consistent or
systematic. It was concluded that MF exposure assessment should consider work
environment in addition to job title to reduce exposure misclassification.
PMID- 10782190
TI - Experimental validation of potential and turbulent flow models for a two
dimensional jet enhanced exhaust hood.
AB - A two-dimensional jet-reinforced slot exhaust hood was modeled using a
mathematical model based on potential flow theory and with a computational fluid
dynamics (CFD) model using the standard k-epsilon model for turbulence closure.
The accuracy of the calculations was verified by air velocity and capture
efficiency measurements. The comparisons show that, for normal operating
conditions, both the models predicted the mean airflows in front of the hood
well. However, the CFD model gave more realistic results in the jet flow region
and also of the short-circuiting flow. Both models became increasingly inaccurate
when the ratio of the supply jet momentum to the exhaust flow rate increased. The
jet enhancement proved to be a very efficient way to increase the effective
control range of exhaust hoods. Controlled air movements can be created at
distances that are two to three times larger than with conventional suction alone
without increasing the exhaust flow rate.
PMID- 10782191
TI - Personal monitoring instrument for the selective measurement of multiple organic
vapors.
AB - Development and laboratory testing of a small instrument capable of recognizing
and quantifying multiple organic vapors at low- and sub-ppm concentrations is
described. The instrument is slightly larger than a standard personal sampling
pump and employs an array of three polymer-coated surface-acoustic-wave
microsensors for vapor detection. Vapors are first trapped on a miniature
adsorbent preconcentrator housed within the instrument and then thermally
desorbed for analysis by the microsensor array. Each measurement cycle requires
5.5 min. The collective responses from the array are stored and then analyzed
using pattern recognition methods to yield the identities and concentrations of
collected vapors and vapor mixture components. Following initial optimization of
instrument operating parameters, calibrations were performed with 16 organic
solvent vapors and selected mixtures to establish a response library for each of
two identical instruments. Limits of detection < or = 0.1 x threshold limit value
were obtained for most vapors. In a series of 90 subsequent exposure tests,
vapors were recognized with an error of < 6% (individual vapor challenges) and <
16% (binary mixture challenges) and quantified with an average error of < 10%.
Monte Carlo simulations were coupled with pattern recognition analyses to predict
the performance for many possible vapor mixtures and sensor combinations.
Predicted recognition errors ranged from < 1 to 24%. Performance is shown to
depend significantly on the interfacial polymer layers deposited on the sensors
in the array and the nature and complexity of the vapor mixtures being analyzed.
Results establish the capability of this technology to provide selective
multivapor monitoring of personal exposures in workplace environments.
PMID- 10782192
TI - Mycobacterial contamination of metalworking fluids: involvement of a possible new
taxon of rapidly growing mycobacteria.
AB - Contamination of air and metalworking fluid (MWF) systems with a rapidly growing
mycobacterium (RGM) was detected in 1995 in a single manufacturing plant with
recent cases of hypersensitivity pneumonitis (HP). Extensive environmental
sampling was performed to determine the extent of the contamination and its
variability over time. RGM were present in multiple indoor air samples, 100% of
the central MWF storage tanks, and 75% of the freestanding cutting, drilling, and
grinding machines. With one exception, contamination was limited to a recently
introduced formulation (brand) of semisynthetic MWF used in 95% of the facility's
machining operations. In general, the mycobacterial counts were stable over time,
with the degree of contamination ranging from 10(2)-10(7) colony forming units
(CFU)/mL. A few systems were culture positive for the mycobacterium (> 10(1)
CFU/mL), changed to culture negative (< 10(1) CFU/mL), then changed back to
culture positive without explanation. Samples obtained from diluted (5%) but
unused MWF, a replenishment line with 2% unused MWF, an MWF pasteurizer, city
water, and deionized water were culture negative for this species of
mycobacterium. Inoculation and growth studies demonstrated that this
mycobacterium does not grow in liquid samples of 5% unused MWF. By molecular
techniques, the mycobacterial isolates consisted of a single strain and
represented a previously undescribed taxon closely related to Mycobacterium
chelonae/abscessus. The relationship of this mycobacterium to the cases of HP is
unknown.
PMID- 10782193
TI - Carbonless copy paper: a review of its chemical components and health hazards.
AB - The components of carbonless copy paper (CCP) and the chemistry involved in its
manufacture are reviewed. Claims that the routine use of CCP can cause health
problems ranging from skin, eye, and lung irritation to severe headaches and
neurological damage are described; yet no definitive studies have been conducted
that show correlation between CCP use and these symptoms. The toxicological
properties of CCP components, many of them precursors to the dye-containing
microcapsules or dye solvents that may be causing these problems, are discussed.
Recommendations for the minimization of possible physiological reactions to CCP
include reduction of usage time; use of the CCP in a well-ventilated area;
storing large quantities of CCP, both new or archived, away from work area; and
the practice good hand hygiene.
PMID- 10782195
TI - Workplace risk factors and occupational musculoskeletal disorders, Part 2: A
review of biomechanical and psychophysical research on risk factors associated
with upper extremity disorders.
AB - Injuries and disorders caused by overexertion and repetitive motion are the
leading causes of compensable lost-time cases in the United States.
Epidemiological and laboratory-based research methods have been used to evaluate
the significance of various risk factors associated with overuse injuries and
disorders. The National Institute for Occupational Safety and Health performed a
comprehensive review of over 600 epidemiological studies in 1997 and concluded
that there was evidence of a causal relationship between workplace exposures to
forceful exertions, repetition, awkward posture, and vibration and disorders of
the neck, shoulder, and upper extremities. Although epidemiological studies
provide important insights to understanding the causes of work-related overuse
disorders, they are sometimes criticized for their inability to measure precisely
how people respond to specific risk factors found in the workplace. This article
presents a review of recent laboratory studies and biomechanical models of work
factors believed to be associated with increased risk of upper extremity injuries
and disorders. Biomechanical models and laboratory studies do not replace
epidemiological studies. However, these approaches provide important
complementary information that is needed to understand the complex process of how
exposures to physical risk factors result in strain that may ultimately lead to
injury or disease. These studies also provide important insights as to how people
react and respond to specific physical risk factors found in the workplace.
Combined with epidemiological research, laboratory studies are an essential
element in understanding the causes and prevention of work-related overexertion
injuries.
PMID- 10782194
TI - Computer users' postures and associations with workstation characteristics.
AB - This investigation tested the hypotheses that (1) physical workstation dimensions
are important determinants of operator posture, (2) specific workstation
characteristics systematically affect worker posture, and (3) computer operators
assume "neutral" upper limb postures while keying. Operator head, neck, and upper
extremity posture and selected workstation dimensions and characteristics were
measured among 379 computer users. Operator postures were measured with manual
goniometers, workstation characteristics were evaluated by observation, and
workstation dimensions by direct measurement. Considerably greater variability in
all postures was observed than was expected from application of basic geometric
principles to measured workstation dimensions. Few strong correlations were
observed between worker posture and workstation physical dimensions; findings
suggest that preference is given to keyboard placement with respect to the eyes
(r = 0.60 for association between keyboard height and seated elbow height)
compared with monitor placement with respect to the eyes (r = 0.18 for
association between monitor height and seated eye height). Wrist extension was
weakly correlated with keyboard height (r = -0.24) and virtually not at all with
keyboard thickness (r = 0.07). Use of a wrist rest was associated with decreased
wrist flexion (21.9 versus 25.1 degrees, p < 0.01). Participants who had easily
adjustable chairs had essentially the same neck and upper limb postures as did
those with nonadjustable chairs. Sixty-one percent of computer operators were
observed in nonneutral shoulder postures and 41% in nonneutral wrist postures.
Findings suggest that (1) workstation dimensions are not strong determinants of
at least several neck and upper extremity postures among computer operators, (2)
only some workstation characteristics affect posture, and (3) contrary to common
recommendations, a large proportion of computer users do not work in so-called
neutral postures.
PMID- 10782196
TI - Chronic beryllium disease and beryllium sensitization at Rocky Flats: a case
control study.
AB - A case-control study was conducted to evaluate the risk of chronic beryllium
disease (CBD) and beryllium sensitization (SENS) associated with various levels
of historical beryllium exposure at the Rocky Flats nuclear weapons facility.
Fifty CBD and 74 SENS cases were matched to controls of the same age group, race,
gender, and smoking status. A job exposure matrix was developed from job history
data and fixed airhead (FAH) exposure data available from 1960 to 1988. Job
titles and building areas were assigned factors based on exposure relative to a
machinist in the Building 444 Beryllium Shop. Concurrence on these factors was
obtained from past and present Rocky Flats industrial hygienists. Using the
matrix, long-term mean and cumulative exposures were estimated for each subject.
Both exposure estimates (p < 0.0001) and years of employment (p = 0.010) were
found to be significantly higher for CBD cases as compared with their controls,
but not so for the SENS cases as compared with their controls. Logistic
regression analyses showed statistically significant relationships between both
cumulative and mean exposure and CBD, but not for SENS. These findings suggest
that reduced worker exposures might lower the future incidence of CBD, but may
not necessarily lower the incidence of SENS.
PMID- 10782197
TI - Benzene and total hydrocarbon exposures in the upstream petroleum oil and gas
industry.
AB - Occupational exposures to benzene and total hydrocarbons (THC) in the Canadian
upstream petroleum industry are described in this article. A total of 1547 air
samples taken by 5 oil companies in various sectors (i.e., conventional oil/gas,
conventional gas, heavy oil processing, drilling and pipelines) were evaluated
and summarized. The data includes personal long- and short-term samples and area
long-term samples. The percentage of samples over the occupational exposure limit
(OEL) of 3.2 mg/m3 or one part per million for benzene, for personal long-term
samples ranges from 0 to 0.7% in the different sectors, and area long-term
samples range from 0 to 13%. For short-term personal samples, the exceedance for
benzene is at 5% with respect to the OEL of 16 mg/m3 or five parts per million in
the conventional gas sector and none in the remaining sectors. THC levels were
not available for all sectors and had limited data points in others. The
percentage exceedance of the OEL of 280 mg/m3 or 100 parts per million for THC as
gasoline ranged from 0 to 2.6% for personal long-term samples. It is recommended
that certain operations such as glycol dehydrators be carefully monitored and
that a task-based monitoring program be included along with the traditional long-
and short-term personal exposure sampling.
PMID- 10782198
TI - Communication using a telephone while wearing a respirator.
AB - Respirators have been found to degrade communication effectiveness when wearers
speak face-to-face. However, little is known about communication effectiveness
when using the telephone and wearing a respirator. Eleven pairs of subjects were
asked to pronounce and identify words chosen from Modified Rhyme Test lists. Each
word appeared on a computer screen in one room and the speaker said the word into
the telephone. The listener in another room identified the word and typed it into
a computer linked with the first. Subjects wore U.S. Army M40 full-facepiece air
purifying respirators with hoods. Three different speech diaphragm arrangements
and two hood materials were tested. Results show that accuracy suffered by about
10% when respirators and hoods were worn compared with the control condition.
Word identification speed was one-third to one-half of the control (no respirator
or hood) condition depending on specific equipment worn.
PMID- 10782200
TI - Mist control at a machining center, Part 1: Mist characterization.
AB - At a machining center used to produce transmission parts, aerosol instrumentation
was used to quantitatively study mist generation and to evaluate the performance
of an air cleaner for controlling the mist. This machining center drilled and
tapped holes at rotational speeds of 1000 to 3000 rpm. During most machining
operations, the metal-working fluid (MWF) was flooded over the part. To
facilitate metal chip removal during some operations, MWF was pumped through the
orifices in some tools at a pressure of 800 psi. These machining operations were
performed in a nearly complete enclosure that was exhausted to an air cleaner at
a flow rate of 1.1 m3/sec (2400 ft3/m). Although the use of high-pressure MWF
increased the mist concentration by about 200%, it did not affect the mist size
distribution. The observed penetration through the air cleaner appeared to be
mostly consistent with the manufacturer's specifications on the air cleaner's
filters. During the testing, MWF was observed to accumulate in the bottom of the
filter housing and may have been reentrained due to air motion or mechanical
vibration.
PMID- 10782199
TI - Field evaluation of a portable photoionization detector for assessing exposure to
solvent mixtures.
AB - To evaluate a portable photoionization detector for assessing personal exposure
to solvent mixtures, a set of 26 side-by-side, time-weighted average (TWA)
personal breathing zone samples were collected during various construction
painting tasks by two different sampling methods: (1) standard charcoal sorbent
tubes analyzed by gas chromatography (CST/GC), and (2) a direct-reading
photoionization detector coupled with an extended data-logger (PID). The TWA
concentrations of the hydrocarbons detected by CST/GC analysis were summed for
comparison with the TWA concentration obtained from the direct-reading PID. Based
on linear regression between the log TWA concentrations of the two sampling
methods, the data were highly correlated (r2 = 0.95). Since the solvents had
effects that may be considered additive, threshold limit values (TLVs) for
mixtures were developed using American Conference of Governmental Industrial
Hygienists formulas to evaluate solvent exposure. The logs of the TLV mixture
data from the sampling methods were highly correlated (r2 = 0.94). Based on the
linear regression analyses, the response of the portable PID was highly
correlated to the CST/GC results for hydrocarbon mixtures encountered during
various painting tasks. Due to the short duration of tasks, highly fluctuating
exposures, and complexity of the mixtures, the PID may provide the most cost
effective, detailed exposure assessment for solvent mixtures.
PMID- 10782201
TI - Mist control at a machining center, Part 2: Mist control following installation
of air cleaners.
AB - At a machining center used to produce transaxle and transmission parts, aerosol
instrumentation was used to quantitatively evaluate size-dependent mist
generation of a synthetic metalworking fluid (MWF) consisting primarily of water
and triethanolamine (TEA). This information was used to select an air cleaner for
controlling the mist. During most machining operations, the MWF was flooded over
the part. These machining operations were performed in a nearly complete
enclosure that was exhausted to an air cleaner consisting of three sections: a
fall-out chamber, a trifilter section to capture metal chips and mist, and a 1.13
m3/sec (2400 ft3/min) blower. The partnering company requested that National
Institute for Occupational Safety and Health (NIOSH) researchers perform an
evaluation of the effectiveness of a commercially available air cleaner. After
NIOSH researchers characterized mist generation at the machining centers and
found that performance of a test air cleaner appeared to be suitable, the company
installed more than 25 air cleaners on different machining centers in this plant
and enclosed the corresponding fluid filtration unit. The facility also has
implemented a maintenance program for the air cleaners that involves regularly
scheduled filter changes; performance is ensured by monitoring static pressure. A
NIOSH-conducted air sampling evaluation showed that area TEA concentrations were
reduced from a geometric mean of 0.25 to 0.03 mg/m3. Personal total particulate
concentrations were reduced from a geometric mean of 0.22 to 0.06 mg/m3. These
results show the effectiveness of this combination of enclosure, ventilation, and
filtration to greatly reduce the exposure to MWF mist generated in modern
machining centers.
PMID- 10782203
TI - Proficiency Analytical Testing (PAT) Program November 1999.
PMID- 10782202
TI - Short-term efficacy of back injury intervention project for patient care
providers at one hospital.
AB - A one-year Back Injury Prevention Program was initiated at a 440-bed acute care
hospital in 1996 in response to concerns over high incidence and severity of back
injuries among nursing staff and others. The program included an ergonomic
evaluation of patient handling, pilot testing and purchase of new equipment, a
train-the-trainer program, and training of 374 nurses and other patient handling
staff (approximately one-half of the nursing staff). An impact evaluation,
measured by comparing self-reported knowledge, work practices, and back pain
among a subset of trainees and controls revealed an increase in knowledge of risk
factors, a marginal increase in the use of mechanical devices to transfer
patients, and a significant decrease in repositioning of patients in bed among
trained versus control subjects (p = .017). Over the course of the program, the
number of back injuries was 30% below the average of the prior 3 years, with the
number of reported injuries in the final quarter (immediately following the
training program) approximately one-seventh of the three prior quarters. It is
concluded that back injury training may increase knowledge of risk factors and
controls and may impact behaviors over which individuals have control (e.g., how
often they move patients). However, training effectiveness is limited when
engineering controls such as patient transfer devices are unavailable.
PMID- 10782204
TI - Environmental Lead Proficiency Analytical Testing (ELPAT) Program September 1999.
PMID- 10782205
TI - Localization of the locus responsible for Chediak-Higashi syndrome in cattle to
bovine chromosome 28.
AB - Chediak-Higashi syndrome in Japanese black cattle is a hereditary disease with
prolonged bleeding time and partial albinism. In the present study, we mapped the
locus responsible for the disease (CHS) by linkage analysis using microsatellite
genotypes of paternal half-sib pedigrees obtained from commercial herds. Analysis
revealed significant linkage between the CHS locus and marker loci on the
proximal end of bovine chromosome 28. The CHS locus was mapped on the region
incorporating the microsatellite markers BMC6020, BM2892, and RM016 with
recombination fraction 0 and lod score 4.9-11.2. We also assigned the bovine
CHS1/LYST, the homologue of the gene responsible for human Chediak-Higashi
syndrome, to bovine chromosome 28 using a bovine/murine somatic cell hybrid
panel. These findings suggest that a mutation in the CHS1/LYST gene is likely to
be responsible for Chediak-Higashi syndrome in Japanese black cattle.
PMID- 10782206
TI - Genetic mapping of a locus associated with bovine chronic interstitial nephritis
to chromosome 1.
AB - Chronic interstitial nephritis with diffuse zonal fibrosis (CINF) occurs in
Japanese Black cattle (Wagyu) as an autosomal recessive disorder leading to death
prior to puberty, first six months or a year of life. We performed a genome-wide
scan using microsatellite markers in a Wagyu pedigree segregating for CINF and
mapped the CINF locus to bovine chromosome 1. CINF was closest to microsatellites
BM9019 and INRA49 (Z score = 12.0; P < 3.4 x 10(-10)).
PMID- 10782207
TI - Differences in gene density on chicken macrochromosomes and microchromosomes.
AB - The chicken karyotype comprises six pairs of large macrochromosomes and 33 pairs
of smaller microchromosomes. Cytogenetic evidence suggests that microchromosomes
may be more gene-dense than macrochromosomes. In this paper, we compare the gene
densities on macrochromosomes and microchromosomes based on sequence sampling of
cloned genomic DNA, and from the distribution of genes mapped by genetic linkage
and physical mapping. From these different approaches we estimate that
microchromosomes are twice as gene-dense as macrochromosomes and show that
sequence sampling is an effective means of gene discovery in the chicken. Using
this method we have also detected a conserved linkage between the genes for
serotonin 1D receptor (HTR1D) and the platelet-activating factor receptor protein
gene (PTAFR) on chicken chromosome 5 and human chromosome 1p34.3. Taken together
with its advantages as an experimental animal, and public access to genetic and
physical mapping resources, the chicken is a useful model genome for studies on
the structure, function and evolution of the vertebrate genome.
PMID- 10782208
TI - Localization of Xho1 repetitive sequences on autosomes in addition to the W
chromosome in chickens and its relevance for sex diagnosis.
AB - Repetitive sequences of the Xho1 family comprise about 70% of the W chromosome in
chickens, are considered to be restricted to this sex chromosome and are used in
sex diagnosis. This study investigated the reliability of sex diagnosis on small
cell numbers. Fluorescent in situ hybridizations (FISH) with the Xho1 repeat
sequence were performed on metaphases and signals were detected on the W
chromosome and on some autosomes. Differences in signal intensity suggested that
the number of repeats ranged from several thousand on the W chromosome to only a
few on the autosomes. These results confirm the report from Clinton (1994) of
minor male products in sex specific PCR of the Xho1 repeat. We adopted his PCR
protocol to analyze small numbers of cells. FISH on blastomeres and on blood
cells from E3 to E11 embryos were compared to PCR results. The FISH procedure as
well as the PCR protocol are suitable for sexing. For single cells FISH was
slightly more consistent.
PMID- 10782209
TI - Patterns of ribosomal gene variation in elite commercial chicken pure line
populations.
AB - The nucleolus organizer region (NOR) encodes the tandemly repeated 18S, 5.8S and
28S ribosomal (r) RNA genes. The NORs of broiler and layer commercial chicken
pure lines were studied to establish the type and extent of genetic variation at
this important locus. The parameters studied were gene copy number, repeat size,
and diversity of NOR-types. The populations were organized into three groups for
analysis including brown-egg broiler (13 lines), brown-egg layer (six lines), and
white-egg layer (eight lines). The ribosomal gene copy number average of the
white-egg layer populations was significantly lower (329 genes) than that of the
brown-egg layers (372 genes); the brown-egg broiler ribosomal gene average was
intermediate (350 genes). The white-egg layer populations exhibited a ribosomal
repeat unit average size of 36 kb, significantly different from the brown-egg
layer and brown-egg broiler average repeat unit size of 32.5 and 33.9 kb,
respectively. NOR array size was similar among the three groups (6 mb). The brown
egg broiler populations exhibited polymorphic NOR patterns, intra- and interline,
whereas the white-egg layer populations were essentially monomorphic for NOR
type; brown-egg layers exhibited an intermediate level of NOR diversity. Some NOR
array characteristics may be a function of breed origin as brown-egg commercial
populations, both broilers and layers, have similar breed origins and exhibited
similarities for predominant repeat unit size as compared with white-egg layer
populations. However, the finding that brown-egg broiler lines typically exhibit
a greater number of segregating NOR-types than brown-egg layer lines suggests
that the selection schemes of broiler vs. layer pure line populations may also
have influenced the degree of variation at this gene complex.
PMID- 10782210
TI - Characterization of Iberian pig genotypes using AFLP markers.
AB - The use of the AFLP (amplified fragment length polymorphism) technique for the
characterization of highly inbred Iberian pig breed genotypes and the detection
of strain-specific polymorphisms is demonstrated. Twelve different primer
combinations were used on individual DNA samples from animals belonging to two
black hairless Iberian pig strains, Guadyerbas and Coronado. These amplification
reactions allowed the detection of more than 1700 amplification products of which
26 were identified as strain-specific markers, present in all individuals of one
strain and absent in the other. Comparison of male and female amplification
products within one strain also allowed the identification of 8 male-specific
amplified bands. AFLP showed a great power of marker detection due to a high
multiplex ratio and high reproducibility. Comparison of similarity and co
ancestry coefficient matrices also showed the usefulness of AFLP markers to
estimate genetic relationships between individuals pigs.
PMID- 10782211
TI - Chromosomal assignment of canine TSC2, PKD1 and CLN3 genes by radiation hybrid-
and linkage analyses.
AB - The canine tuberous sclerosis 2 (TSC2) gene has been mapped to canine chromosome
6 using a canine whole genome radiation hybrid panel. There is close linkage
between canine TSC2 and the polycystic kidney disease 1 gene (PKD1), as has been
observed in humans and other mammalian species. The gene responsible for the
human juvenile form of neuronal ceroid lipofuscinosis (CLN3), maps close to TSC2
and PKD1 in humans, and is also syntenic in the dog. We further demonstrate
linkage to a group of polymorphic markers assigned to canine chromosome 6 (CFA6).
PMID- 10782212
TI - Y-specific microsatellite polymorphisms in a range of bovid species.
AB - At least five dinucleotide (CA)n microsatellite repeat arrays have been assigned
to the bovine Y-chromosome, with one marker (INRA124) shown to be polymorphic. We
describe here the assessment of a panel of four Y-specific microsatellite markers
for polymorphism in a range of cattle and related species. It was possible to
amplify all the markers in the animals sampled and all showed variation. Three of
the microsatellite loci (INRA124, INRA189 and BM861) displayed putative taurine-
and zebu-specific alleles which can be useful indicators of male-mediated gene
flow in hybrid populations. In the future these microsatellites, in combination
with other Y-specific markers should provide a high-resolution Y haplotype system
for evolutionary studies in both domesticated cattle and other related species.
PMID- 10782213
TI - Resolution of conflicting assignments for the bovine casein kinase II alpha
(CSNK2A2) gene.
AB - The casein kinase II alpha' gene (CSNK2A2), which physically maps to human
chromosome 16 (HSA16), has previously been mapped to bovine chromosome 5 (BTA5).
Based on these results, a new segment of homology between the human and bovine
genomes was suggested. In this paper we demonstrate linkage between CSNK2A2 and
several markers on BTA18. Our result is supported by the extensive conservation
of synteny between HSA16q and BTA18. Bovine chromosome 18 markers used in this
study included several microsatellites, as well as the MC1R gene previously
mapped to HSA16q24.3. Sequencing of the PCR-fragment mapped to BTA5 reveals that
a CSNK-like retroposon was responsible for the conflicting assignments. The
present results further extend the observed conservation of synteny between
HSA16q and BTA18.
PMID- 10782215
TI - Eight new dinucleotide microsatellite loci in turkey (Meleagris gallopavo).
PMID- 10782214
TI - Exclusion of the PDE6A gene for generalised progressive retinal atrophy in 11
breeds of dog.
AB - The cyclic guanosine monophosphate specific phosphodiesterase (cGMP-specific PDE)
is a key enzyme in the phototransduction cascade of the vertebrate retina. This
enzyme consists of two catalytic alpha and beta subunits, two identical
inhibitory gamma subunits as well as a delta subunit. Mutations in PDE6A and the
PDE6B genes lead to autosomal recessive (ar) forms of retinitis pigmentosa (RP)
in human and to the homologous disease in dogs, designated generalised
progressive retinal atrophy (gPRA). We investigated the PDE6A gene in 13 gPRA
affected dog breeds including healthy animals, obligate gPRA carriers and gPRA
affected dogs. In the coding region of PDE6A only a rare sequence variation
(G103A; Asp35Asn) was found in exon 1 of two healthy Tibet Terriers and one
affected Cocker Spaniel. Using single-stranded conformation polymorphism (SSCP)
analyses we detected several sequence variations in eight of the PDE6A introns in
different investigated breeds. Most informative for excluding the PDE6A gene as a
cause for gPRA was a polymorphic microsatellite ((GT)10CG(GT)2CG(GT)12) in intron
14 and four sequence variations in intron 18 for almost all breeds investigated.
The sequence variations of PDE6A did not segregate together with gPRA in 11
breeds. Since diseased animals were heterozygous for the polymorphisms, the PDE6A
gene is unlikely to harbour the critical mutation causing gPRA in the following
breeds: Chesapeake Bay Retriever. Entlebucher Sennenhund, Labrador Retriever.
Tibet Mastiff, Dachshund (long- and wire-haired), Tibetan Terrier, Miniature
Poodle. Australian Cattle Dog, Cocker Spaniel, Saarloos/Wolfshound, Sloughi.
PMID- 10782216
TI - Genetic variations in the ovine calpain regulatory subunit.
PMID- 10782217
TI - Twenty-one new equine dinucleotide repeat microsatellites.
PMID- 10782218
TI - Polymorphic microsatellites associated with the equine CKM and CMA1 genes.
PMID- 10782219
TI - The gene encoding a chicken chemokine with homology to human SCYC1 maps to
chromosome 1.
PMID- 10782220
TI - Two polymorphic microsatellite markers from novel Penaeus monodon ESTs.
PMID- 10782221
TI - Chromosomal assignments and polymorphism information content in sheep for 12
cattle microsatellites.
PMID- 10782222
TI - Linkage mapping of goat ChirUCO, LSCV and SR-CRSP microsatellites in sheep.
PMID- 10782223
TI - Ten equine dinucleotide microsatellite repeats HTG18-19, HTG22-24, HTG26-27,
HGT29-30 and HTG32.
PMID- 10782224
TI - A TaqI PCR-RFLP at the bovine myogenic factor (MYF5) gene.
PMID- 10782225
TI - The porcine adenosine monophosphate deaminase 1 (AMPD1) gene maps to chromosome
4.
PMID- 10782226
TI - Dinucleotide repeat polymorphism at the ovine McMA1, McMA2, McMA5, McMA8, McMA9,
McMA11, McMA14, McMA20, McMA24, McMA26 loci.
PMID- 10782227
TI - The isolation and characterization of 18 equine microsatellite loci, TKY272
TKY289.
PMID- 10782228
TI - A NciI PCR-RFLP within intron 2 of the porcine insulin-like growth factor 2
(IGF2) gene.
PMID- 10782229
TI - Broad taxonomic applicability of microsatellites developed for the highly
polymorphic neotropical cichlid, Amphilophus citrinellum.
PMID- 10782231
TI - A PCR test for mitochondrial heteroplasmy in sturgeon.
PMID- 10782230
TI - Two polymorphic markers for the horse SLC11A1 (NRAMP1) gene.
PMID- 10782232
TI - Mapping of the oncogene c-myc (MYC) and the breast cancer susceptibility gene
(BRCA2) in the pig by FISH.
PMID- 10782233
TI - HpaII PCR-RFLP within a Bov-A2 element in the promoter of the bovine CYP21
(steroid 21-hydroxylase) gene.
PMID- 10782234
TI - Four PCR-RFLPs and a sequence polymorphism in the porcine c-myc proto-oncogene
and confirmation of the chromosomal localisation on SSC4 by linkage mapping.
PMID- 10782236
TI - [Cardiopulmonary resuscitation: anecdote or public health problem?].
PMID- 10782235
TI - Linkage mapping of an AvaI PCR-RFLP within the porcine uncoupling protein 3
(UCP3) gene.
PMID- 10782237
TI - [Colonization by methicillin-resistant Staphylococcus aureus is a predictive
factor for the resistance phenotype of an infectious strain of S. aureus].
AB - OBJECTIVE: To assess the predictive value of a previous colonization with
methicillin-resistant Staphylococcus aureus for the resistance pattern of a
bacteriological specimen significantly positive to S. aureus. STUDY DESIGN:
Retrospective study of patients' files. PATIENTS: Patients admitted for at least
48 hours in a surgical intensive care unit from April 1, 1996 to December 31,
1997. METHODS: Collection of patients' characteristics and chronology of positive
microbiological specimens with methicillin-susceptible (MSSA) or -resistant
(MRSA) S. aureus from medical and laboratory records. During the study period,
screening for nasal or perineal colonization with MRSA was systematically
performed on admission and weekly thereafter. RESULTS: The files of 540 patients
were reviewed. MSSA and MRSA infections occurred in 7% (39/540) and 4% (20/540)
of the patients respectively. By opposition with MSSA infections, MRSA infections
occurred more frequently in patients previously colonized with MRSA (13
infections in 63 colonized patients [21%] versus 7 infections in 477 non
colonized patients [2%], odds ratio = 18, confidence interval: 6-51, P < 0.0001).
The median delay between colonization and infection was 5 days. The positive and
negative predictive values for previous colonization with MRSA to predict
infection with MRSA in presence of a bacteriological specimen significantly
positive with S. aureus were 81 and 84%, respectively. CONCLUSION: The
probabilistic use of a glycopeptide in presence of a bacteriological specimen
significantly positive with S. aureus should be limited to patients already
colonized with MRSA, in order to decrease the abusive administration of these
antibiotics.
PMID- 10782238
TI - [Effect of bronchial drainage on the improvement in gas exchange observed in
ventral decubitus in ARDS].
AB - OBJECTIVES: A bronchial secretion draining effect is frequently suggested as a
mechanism for oxygenation improvement during prone positioning (PP) in patients
with acute respiratory distress syndrome (ARDS). Nevertheless, it has never
really been evaluated. The aim of this study was to search for an
interrelationship between the volume of the bronchial secretion and the
improvement of the PaO2/FIO2 ratio during prone positioning, with NO inhalation
or not. STUDY DESIGN: Open prospective clinical study. PATIENTS: The study
included 15 consecutive patients with severe ARDS (PaO2/FIO2 < 200 after alveolar
recruitment, Murray score > 2.5). METHODS: They were returned to the prone
position for 4 hours (h0-h4) combined with an inhalation of 5 ppm NO during 1
hour (h2-h3). Tracheal suction were performed hourly between h-2 and h6 and
weighed on a precision scale from h-1 to h6. Haemodynamic, blood gas and
respiratory compliance were recorded at h0, h2, h3, h4 and h6. RESULTS: No
significant haemodynamic changes were observed in the various phases. Compared
with the baseline condition at h0, PP and PP + NO respectively improved PaO2/FIO2
by 102 +/- 62% at h2 (P < 0.005) and 156 +/- 79% at h3 (P < 0.005/h0 and <
0.01/h2). 14/15 patients responded to PP and 15/15 to PP + NO (gain in PaO2/FIO2
> 10%). Concerning secretions, we collected 3.0 +/- 7.5 g, 4.4 +/- 6.1 g, 1.7 +/-
1.4 g and 1.7 +/- 1.6 between h-2 and h0, h0 and h2, h2 and h4, h4 and h6.
Individual assessments showed no relationship between the PaO2/FIO2 evolution at
any time and the quantity of secretions obtained during the first 2 hours in the
prone position. Six patients presented secretions of less than 1 g between h0 and
h2, and for whom the improvement in oxygenation was higher than average (115 +/-
53% at h2). CONCLUSION: In patients with little or moderate secretions, the
improvement observed in oxygenation, with or without NO, does not depend on their
volume.
PMID- 10782239
TI - [Effect of a lung contusion on the prognosis of severe head injury in the child].
AB - OBJECTIVES: To assess the effects of a pulmonary contusion (PC) on the outcome of
a severe head trauma (SHT) in children less than 15-year-old. STUDY DESIGN:
Retrospective study. PATIENTS: The study included 30 severely head injured
children with a Glasgow Coma Scale score (GCS) < or = 8, associated with a PC
(PC+) diagnosed on a thoracic CT-scan and 30 severely head injured children
without PC (PC-). METHODS: Outcome was assessed using the Glasgow Outcome Scale
(GOS), on discharge and six months later. Age, body weight, gender, GCS, PTS,
ISS, hypoxaemia, arterial hypotension, the results of the cerebral CT-scan, the
main treatment administered, complications, the duration of tracheal intubation
as well as the duration of stay in the intensive care unit (ICU) and in the
hospital were compared between groups. RESULTS: GCS median was lower (6 vs 8, P =
0.001) and ISS median higher (25 vs 23, P = 0.0004) in the PC+ group. Hypoxaemia
was more frequent in the PC+ group (n = 12 vs n = 0, P = 0.0001). There was no
difference between groups regarding the results of cerebral CT scan. Blood
transfusion was more frequently used in the PC+ group (n = 14 vs n = 5, P =
0.03). Median duration of tracheal intubation, and of stay in the ICU and in the
hospital were shorter in the PC- group (respectively 8 vs 6 days, P = 0.03; 10 vs
7.5 days, P = 0.008; 13.5 vs 10.5 days, P = 0.01). No difference was observed
regarding complications between groups. GOS on discharge was higher in the PC+
group (3 vs 2, P = 0.01). There was an increase in GOS at six months in the two
groups, however GOS remained significantly higher in the PC+ group (median values
2 vs 1, P = 0.002). A favourable outcome occurred less frequently in the PC+
group on discharge and at six months (respectively n = 14 vs 25, P = 0.006; n =
20 vs 28, P = 0.02). CONCLUSION: The association of a PC to a severe head trauma
is responsible for a poorer outcome in children, probably because, at least in
part, a higher incidence of hypoxaemia.
PMID- 10782240
TI - [Equipment surveillance of implantable catheter ports (1996-1998). Members of Sub
Commissions 4a and 4b for Equipment Surveillance].
AB - We analyse all incident reports to the French Health Ministry over the 1996-1998
period, concerning implantable catheter ports. They represent 7% of all reports
in the field of anaesthesia and intensive care. Two hundred eleven reports have
been analysed. There were 93 catheter ruptures with 77 intravascular migrations.
In more than 50% of cases, a pinch-off syndrome mechanism was responsible of
these ruptures and a displacement of the O'ring was involved in 25%. Additional
minor complications were reported and discussed in regard to literature. We
conclude that implantable catheter ports may lead to serious incidents which are
preventable in most cases.
PMID- 10782242
TI - [Puffer fish poisoning].
AB - We report three cases of a collective tetrodotoxin poisoning, after ingestion of
puffer fish eggs. This neurotoxin is the most potent membrane stabilizer,
blocking the nervous conduction and resulting in death from respiratory paralysis
in case of massive ingestion. The father died at admission, the mother and her
daughter presented an acute respiratory failure and a flaccid tetraplegia, with
favourable outcome after 24 hours.
PMID- 10782243
TI - [Diagnosis of a persistent left superior vena cava in the operating room during a
central venous catheterization].
AB - A 2-year-old boy was admitted for surgical excision of a hepatoblastome. A
central venous catheter was inserted by a subclavian approach, without
difficulty. The chest radiograph showed the catheter positioned along the left
heart border. The diagnosis of persistent left superior vena cava was suspected
after analysis of the central venous pressure curve. An postoperative chest X-ray
confirmed the diagnosis. The catheter was maintained for five days without any
complication.
PMID- 10782241
TI - [Glycopeptides].
AB - OBJECTIVES: To review pharmacology, pharmacokinetic and therapeutic use of
glycopeptides in intensive care units. DATA SOURCES: Extraction from Medline
database of French and English articles on glycopeptides and search along with
major review articles. DATA SELECTION: The collected articles were reviewed and
selected according to their quality and originality. The more recent data were
selected. DATA SYNTHESIS: Glycopeptides are bactericidal antibiotics which are
only active against Gram positive species acting by inhibiting peptidoglycan
synthesis. They had been in clinical use for almost 30 years without high-level
resistance underlining. For ten years, there have been disturbing reports of
first, resistance to vancomycin in enterococcal species and more recently in
strains of Staphylococcus aureus by complex and large mechanisms of action. This
new resistances may lead to a therapeutic impasse and a fatal issue for infected
patients. The only response to this situation is the respect of prescription
rules and the careful use of antibiotics. CONCLUSION: Considering their spectrum,
glycopeptides are an antibiotic family which importance is fundamental to treat
infected patients of intensive care units. Staff members of intensive care units
are responsible for their good use.
PMID- 10782244
TI - [Multi-recurrent cardiac arrest: when to discontinue cardiopulmonary
resuscitation?].
AB - A 52-year-old man developed an out-of-hospital cardiac arrest complicating a
myocardial infarction. After prolonged cardiopulmonary resuscitation, he was
admitted to an intensive care unit, where 25 episodes of cardiac arrests occurred
within a few hours. Finally the outcome was favourable. This case raises the
question of the duration a cardiopulmonary resuscitation in case of out-of
hospital and in-hospital cardiac arrest. The question is to determine how long
resuscitation efforts must be prolonged after recurrent cardiac arrests.
PMID- 10782245
TI - [Chance discovery of methanol poisoning during a state of inebriation].
AB - We report a case of wood alcohol (methylated spirits) poisoning in a 40-year-old
chronic alcoholic. The initial diagnosis of state of drunkenness was supported by
the increased plasma level of ethanol (4.66 g.L-1) obtained with enzymatic
method. The confirmation, using gas chromatography (GC), showed an unexpected
peak with a retention time at 1.19 min, characteristic of methanol (0.41 g.L-1).
The GC analysis of the absorbed beverage revealed a 5% methanol content. The
osmolal gap was 115 mOsm.kg-1, with 13 mOsm.kg-1 due to methanol and 90 mOsm.kg-1
to ethanol. Seven hours after the ingestion, the anion gap was at 13 mmol-1. This
result reflected the inhibition of methanol oxidation by alcohol-dehydrogenase,
when the plasma ethanol concentration was above 1 g.L-1. This concentration was
maintained by continuous intravenous administration of (Curethyl-A) a 95% ethanol
containing solution, until methanol concentration decreased below 0.2 g.L-1. The
outcome was favourable without neurological and ophthalmological sequelae.
PMID- 10782246
TI - [Is an authorization for care necessary for the incapacitated adult?].
AB - We report the case of a 30-year-old mentally disabled patient who presented for
diagnostic colonoscopy. This patient raised the problem of authorization for such
a procedure and the related anaesthetic. The French law of 1968 on the protection
of severely incapacitated persons does not clearly solve the problem of the
consent for procedures with a therapeutic finality. The distinction relies
usually on the extent of the planned act, for asking for an agreement of the
guardian, judge of guardianship or the family board. In such cases the problem of
the practice of an anaesthetic remains unsolved. For scheduled procedures it is
recommended to obtain the written consent of the guardian before any medical act.
PMID- 10782247
TI - [Possibility of an incorrect connection between certain respiratory filters and
the expiratory segment of the Ambu-A non-rebreathing valve].
AB - Several models among the contemporary disposable bacterial filters, heat and
moisture exchangers can be inadvertently inserted into the expiratory port of the
Ambu A nonrebreathing valve. Such a misconnection, which does not allow
expiration, is made possible because of the respective sizes of the connection
ports of the devices. International standards and French regulations specify
neither the internal diameter of the expiratory port of the nonrebreathing
valves, nor the external diameter of the circuit connecting port of the
respiratory filters.
PMID- 10782248
TI - [How to read a scientific paper. Committee for Clinical References of the French
Anesthesia and Resuscitation Society].
AB - Every scientific article has to undergo a critical reading before its conclusions
can be accepted. This article discusses the tools for assessing the scientific
value of a study. A sequence of methodological criteria allows quality evaluation
of an article and its classification in a scale of level of proof.
PMID- 10782249
TI - [Interactions between the opioid and cannabinoid systems].
PMID- 10782250
TI - [Compartment syndrome and rhabdomyolysis in pediatric neurosurgery].
PMID- 10782251
TI - [Severe hypernatremia secondary to gastric lavage].
PMID- 10782252
TI - [An experience of training in locoregional anesthesia in an African country].
PMID- 10782254
TI - Which retinal and extra-retinal information is crucial for circular vection?
AB - In contradistinction to conventional wisdom, we propose that retinal image slip
of a visual scene (optokinetic pattern, OP) does not constitute the only crucial
input for visually induced percepts of self-motion (vection). Instead, the
hypothesis is investigated that there are three input factors: 1) OP retinal
image slip, 2) motion of the ocular orbital shadows across the retinae, and 3)
smooth pursuit eye movements (efference copy). To test this hypothesis, we
visually induced percepts of sinusoidal rotatory self-motion (circular vection,
CV) in the absence of vestibular stimulation. Subjects were presented with three
concurrent stimuli: a large visual OP, a fixation point to be pursued with the
eyes (both projected in superposition on a semi-circular screen), and a dark
window frame placed close to the eyes to create artificial visual field
boundaries that simulate ocular orbital rim boundary shadows, but which could be
moved across the retinae independent from eye movements. In different
combinations these stimuli were independently moved or kept stationary. When
moved together (horizontally and sinusoidally around the subject's head), they
did so in precise temporal synchrony at 0.05 Hz. The results show that the
occurrence of CV requires retinal slip of the OP and/or relative motion between
the orbital boundary shadows and the OP. On the other hand, CV does not develop
when the two retinal slip signals equal each other (no relative motion) and
concur with pursuit eye movements (as it is the case, e.g., when we follow with
the eyes the motion of a target on a stationary visual scene). The findings were
formalized in terms of a simulation model. In the model two signals coding
relative motion between OP and head are fused and fed into the mechanism for CV,
a visuo-oculomotor one, derived from OP retinal slip and eye movement efference
copy, and a purely visual signal of relative motion between the orbital rims
(head) and the OP. The latter signal is also used, together with a version of the
oculomotor efference copy, for a mechanism that suppresses CV at a later stage of
processing in conditions in which the retinal slip signals are self-generated by
smooth pursuit eye movements.
PMID- 10782253
TI - Morphology of lumbar-projecting lateral vestibulospinal neurons in the brainstem
and cervical spinal cord in the squirrel monkey.
AB - The lateral vestibulospinal tract (LVST) is one of the major descending pathways
controlling the extensor musculature of the body. To determine whether individual
LVST neurons terminating in the lumbosacral spinal segments issue collaterals
more rostrally to exert an influence of the cervical ventral horn intracellular
recording and biocytin labeling techniques were used in the squirrel monkey. Only
neurons monosynaptically related to the 8th nerve and antidromically identified
to project below T12 were selected for study. The axon course through the
brainstem and cervical spinal cord was examined in 37 LVST neurons. The average
distance of recovered axon was 17.3 mm (4.5-31.7 mm). None could be
antidromically activated from shocks applied to the rostral medial longitudinal
fasciculus near the 3rd nuclei; and no collaterals were observed in the
brainstem. Of the 37 neurons, only 1 axon issued a collateral to innervate the
ventral horn, primarily in the region of the spinal accessory motoneurons; this
single collateral provided a relatively minor input compared to that of LVST
neurons terminating in the cervical cord. Thus, secondary, caudal-projecting LVST
neurons represent a private, and mostly rapid, communication pathway between
dorsal Deiters' nucleus and the motor circuits controlling the lower limbs and
tail.
PMID- 10782255
TI - Visual contributions to human self-motion perception during horizontal body
rotation.
AB - It is still an enigma how human subjects combine visual and vestibular inputs for
their self-motion perception. Visual cues have the benefit of high spatial
resolution but entail the danger of self motion illusions. We performed
psychophysical experiments (verbal estimates as well as pointer indications of
perceived self-motion in space) in normal subjects (Ns) and patients with loss of
vestibular function (Ps). Subjects were presented with horizontal sinusoidal
rotations of an optokinetic pattern (OKP) alone (visual stimulus; 0.025-3.2 Hz;
displacement amplitude, 8 degrees) or in combinations with rotations of a Barany
chair (vestibular stimulus; 0.025-0.4 Hz; +/- 8 degrees). We found that specific
instructions to the subjects created different perceptual states in which their
self-motion perception essentially reflected three processing steps during pure
visual stimulation: i) When Ns were primed by a procedure based on induced motion
and then they estimated perceived self-rotation upon pure optokinetic stimulation
(circular vection, CV), the CV has a gain close to unity up to frequencies of
almost 0.8 Hz, followed by a sharp decrease at higher frequencies (i.e.,
characteristics resembling those of the optokinetic reflex, OKR, and of smooth
pursuit, SP). ii) When Ns were instructed to "stare through" the optokinetic
pattern, CV was absent at high frequency, but increasingly developed as frequency
was decreased below 0.1 Hz. iii) When Ns "looked at" the optokinetic pattern
(accurately tracked it with their eyes) CV was usually absent, even at low
frequency. CV in Ps showed similar dynamics as in Ns in condition i),
independently of the instruction. During vestibular stimulation, self-motion
perception in Ns fell from a maximum at 0.4 Hz to zero at 0.025 Hz. When
vestibular stimulation was combined with visual stimulation while Ns "stared
through" OKP, perception at low frequencies became modulated in magnitude. When
Ns "looked" at OKP, this modulation was reduced, apart from the synergistic
stimulus combination (OKP stationary) where magnitude was similar as during
"staring". The obtained gain and phase curves of the perception were incompatible
with linear systems prediction. We therefore describe the present findings by a
non-linear dynamic model in which the visual input is processed in three steps:
i) It shows dynamics similar to those of OKR and SP; ii) it is shaped to
complement the vestibular dynamics and is fused with a vestibular signal by
linear summation; and iii) it can be suppressed by a visual-vestibular conflict
mechanism when the visual scene is moving in space. Finally, an important element
of the model is a velocity threshold of about 1.2 degrees/s which is instrumental
in maintaining perceptual stability and in explaining the observed dynamics of
perception. We conclude from the experimental and theoretical evidence that self
motion perception normally is related to the visual scene as a reference, while
the vestibular input is used to check the kinematic state of the scene; if the
scene appears to move, the visual signal becomes suppressed and perception is
based on the vestibular cue.
PMID- 10782256
TI - Behavioural motor effects of MK-801 and DNQX parenteral administration in adult
cats: dose-response analysis. Modulatory role of dopaminergic D1 and D2
antagonists on MK-801 induced motor behaviours.
AB - 1. Administration of MK-801 a selective antagonist of the NMDA receptors (50, 100
and 150 micrograms/kg, s.c.) elicited in adult cats ataxia and loss of
equilibrium. A dose-response effect was observed. 2. Administration of DNQX, a
selective antagonist of the non-NMDA receptors, even with doses 20 times higher
than those employed with MK-801, did not produce any behavioural disturbances. 3.
Previous injection of SCH 23390, a selective parenteral antagonist of dopamine D1
receptor, reduced significantly the intense ataxic effects of MK-801, while
sulpiride only increased the latency of the symptoms. 4. The results are
discussed considering the reported interactions between the dopaminergic and
glutamatergic systems.
PMID- 10782257
TI - Copper sensitivity in dorsal hippocampus slices.
AB - The action of copper on the pyramidal neurons in CA1 of the hippocampus is little
understood. Our main aim was to study the possible interaction of copper on the
synaptic network in CA1 pyramidal neurons. We used Wistar rats hippocampus slices
in a recording chamber. The population response ("population of spikes")
collected by an extracellular micropipette under baseline conditions served as
control. Copper, GABA, bicuculline and picrotoxin were delivered in different
experimental conditions to the slice. One, 10 and 100 microM of copper
concentration decreased significantly the amplitude and duration of the
population spikes in relation to the control response. This effect did not show
concentration dependency. Copper in bicuculline medium decreased significantly
the duration response in relation to the control response and in relation to
copper effect in a free bicuculline medium. This phenomenon emphasizes the copper
action on the GABA (B) and (C) receptors. Copper in a picrotoxin medium increased
significantly the excitability of the response. This new effect suggests that
copper acts on non-GABA receptors, an effect that could be detected when the GABA
receptors were inactivated. As a result of these findings it appears that, under
our experimental conditions, copper generated transient sensitivity changes in
pyramidal neurons of CA1 dorsal hippocampus.
PMID- 10782258
TI - Mapping of alpha-melanocyte-stimulating hormone-like immunoreactivity in the cat
brainstem.
AB - The distribution of alpha-melanocyte-stimulating hormone-like immunoreactive
structures was studied in the brainstem of the cat using an indirect
immunoperoxidase technique. Immunoreactivity was observed in several brainstem
nuclei of the cat in which no immunoreactivity had been previously reported.
Immunoreactive fibres were observed in the following; the inferior central
nucleus; the pontine gray nuclei; the Kolliker-Fuse nucleus; the motor trigeminal
nucleus, the anteroventral cochlear nucleus; the abducens nucleus; the
retrofacial nucleus; the superior, lateral, inferior, and medial vestibular
nuclei; the lateral nucleus of the superior olive; the external cuneate nucleus;
the nucleus of the trapezoid body; the postpyramidal nucleus of the raphe; the
medial accessory inferior olive; the dorsal accessory nucleus of the inferior
olive; the nucleus ambiguus; the principal nucleus of the inferior olive; the
preolivary nucleus; the nucleus ruber; the substantia nigra; and in the area
postrema. Our results point to a more widespread distribution of alpha-melanocyte
stimulating hormone-like immunoreactive structures in the cat brainstem than that
reported in previous studies carried out in the same region of the cat, rat and
humans.
PMID- 10782260
TI - ["Smoking I await..."].
PMID- 10782259
TI - An intracellular study of pudendal afferent inputs onto tail motoneurons in the
spinalized cat.
AB - Postsynaptic potentials, elicited by stimulation of the sensory pudendal (SPud)
and superficial perineal nerves (SPeri) on both sides, were recorded from
motoneurons innervating tail muscles in the non-anaesthetized and spinalized cat.
The stimulation of SPud and SPeri on both sides predominantly produced excitatory
postsynaptic potentials (EPSPs) in all kinds of tail motoneurons (70-95%). The
inhibitory postsynaptic potentials (IPSPs) were often observed in motoneurons
innervating ventral tail muscles (30-33%). The means of averaged central
latencies of EPSPs and IPSPs ranged from 4.3 to 7.3 ms, and from 4.6 to 8.4 ms,
respectively. The findings suggests that polysynaptic neuronal pathways from
pudendal nerve to tail motoneurons produce tonic activities of all tail muscles
to raise the tail in micturation, defecation and sexual movements which are
induced by stimulation of pudendal nerves.
PMID- 10782261
TI - [School-age smoking in the province of Seville. Epidemiology and influence of
personal and social environment (smoking prevention campaign, 1998-1999)].
AB - OBJECTIVE: To study the prevalence os smoking in school children in Sevilla and
the influence of personal and social environment on smoking patterns. METHODS:
This study was part of a preventative anti-smoking campaign in schools. Students
filled in anonymous questionnaires based on the World Health Organization survey
instrument for population attitudes and habits. RESULTS: We surveyed 3385
students between 10 and 19 years of age at 47 schools in Seville and 28 villages
in the surrounding province. Current smoking was reported by 19.1% of the
students; slightly more girls (19.8%) than boys (18.3%) smoked. Smoking was
related to having an older brother or sister who smoked and particularly to
having friends who smoked (OR 20.5). The adolescents reported that parents were
less permissive than the rest of their environment. Smokers associated tobacco
with values such as independence and freedom; they believed that smoking might
have an impact on health, although their conviction was less strong than that of
non-smokers, regular smokers had high expectations of continuing. CONCLUSIONS: We
found a high proportion of smokers among students of both sexes. Starting and
continuing to smoke during adolescence is considerably influenced by the social
environment of peers and is possibly affected by messages of independence and
freedom transmitted through tobacco industry advertising.
PMID- 10782262
TI - [Minimal intervention in smoking in Spain].
AB - OBJECTIVE: To determine the percentage of smokers who have been counseled by a
physician to quit, among patients who visit a variety od specialist clinica; to
identify the characteristics associated with a history of minimal intervention.
PATIENTS AND METHODS: An anonymous survey of 501 patients over 14 years of age
(230 men, 271 women; mean age of 51.4 yr) who were out patients in cardiology
(61), neurology (68), digestive medicine (124), endocrinology (22), internal
medicine (14), otorhinolaryngology (53) and dermatology (159) over a period of
one week. The questionnaire asked if the patient smoked currently and if so, if a
physician had ever recommended quitting. The association between a history or
minimal intervention and other variables was evaluated using Spearman a
correlation coefficient. RESULTS: 1) One hundred fifteen (22.9%) were smokers. 2)
Only 49 (42.6%) of the smokers reported that a physician had advised quitting and
66 (57.4%) reported that none had done so. 3) We found an association between a
history of minimal intervention and older age (rs = -0.246; p = 0.008) and male
sex (rs = 0.244; p = 0.009). CONCLUSIONS: The infrequency with which physicians
counsel patients to quit in our setting suggests an urgent need for the Spanish
health authorities to develop programs aimed at minimal intervention.
PMID- 10782263
TI - [Individual treatment of smoking addiction. Results using 2 and 4 mg nicotine
gum].
AB - We present the results of an open follow-up study aimed at analyzing the efficacy
of combining psychological counseling with prescription of 2 and 4 mg nicotine
gum to treat smokers. Two groups of smokers wer studied. Group A contained 124
subjects (74 men, 50 women) with a mean age of 37.4 (15.3) yr who were smokers of
15.3 (8.7) cigarettes/day. In this group physical addiction to nicotine was low,
assessed as 1.7 (1.3) on the Fagerstrom test. Group B consisted of 107 subjects
(61 men, 46 women) with a mean age of 38.9 (14.6) who were smokers of 26.9 (9.3)
cigarettes/day and whose level of physical addiction to nicotine was moderate-to
high, assessed as 6.1 (2.4) on the Fagerstrom test. Standard deviations are shown
between parentheses. Both groups were given minimal psychological counseling;
additionally, patients were prescribed one piece of nicotine gum very 90 to 120
minutes during waking hours (2 mg in group A and 4 mg in group B). The dose was
gradually reduced after the sixth to the eight week. The subjects were seen eight
times over the first year (first day of consultation and during the first,
second, fourth, eight and twelfth weeks after quitting, and again after six and
twelve months). After twelve weeks of follow-up, sixty-one subjects (49%) in
group A and 50 (47%) in group B were still abstinent. These proportions fell to
56 (45%) and 46 (43%), respectively, after one year of follow-up. Eighty-one
percent of group A patients who were successful after three months of follow-up,
and 87% of the successful group B patients, had used the nicotine gum as
prescribed. Oropharyngeal, dental, and temporo-mandibular joint symptoms,
hiccoughins, flatulence and heartburn were the most frequent side effects
(ranging from 3% to 18%). Side effects were always slight and were not detected
after the eighth week of treatment. In conclusion, combined therapy (minimal
psychological counseling plus use of 2 or 4 mg nicotine gum depending on the
level of physical addiction) yields a success rate between 43% and 45% still
abstaining after one year of follow-up. Side effects are few and mild.
PMID- 10782264
TI - [Attitudes to smoking and characteristics of the habit among a group of young
asthmatics compared to a group of non-asthmatics].
AB - OBJECTIVE: To compare the attitudes toward smoking and smoking patterns of young
male asthmatics with the attitudes and habits of a group previously studied non
asthmatic men. POPULATION AND METHODS: Volunteers responded individually to as
anonymous questionnaire. RESULTS: Responses were received from 488 asthmatics men
(55.83%) of the sample, with 11 not responding) and 386 non-asthmatics (44.16%,
with 27 not responding). The mean age of subjects was 19.91 +/- 2.76 yr. Smoking
asthmatics numbered 154 (31.56%) non-asthmatic smokers numbered 207 (53.6%) (p <
0.001). Eighteen asthmatics (3.68%) and 6 (1.55%) non-asthmatics were ex-smokers.
The mean age of initiation was 15.20 +/- 2.42 for asthmatics and 15.08 +/- 2.41
for non-asthmatics. Smoking was established at a mean age of 16.56 +/- 2.04 yr
for asthmatics and 16.47 +/- 2.18 yr for non-asthmatics. Sixty-two percent of
asthmatics smoked fewer than 10 cigarettes/day whereas 55% of non-asthmatics
smoked between 11 and 20 cigarettes/day. The mean Fagerstrom score were 2.59 +/-
2.2 for asthmatics and 4.66 +/- 2.2 for non-asthmatics (p < 0.001). Fifty-four
percent of asthmatics and 47% non-asthmatics were considering quitting. Sixty
five percent of asthmatics and 44% of non-asthmatics had previously tried to quit
(p < 0.01) and mean duration of abstinence was 4.6 +/- 3.8 months and 3.8 +/-
4.6, respectively (p < 0.05). No differences were found in the reason for
starting to smoke. We found that the companions and friends of asthmatics smoked
less than did the friend and acquaintances of non-asthmatics (p < 0.001),
although that differences was not found for relatives, the friends, relatives and
companions of smoking asthmatics smoked more than did those of non-smoking
asthmatics. CONCLUSIONS: The prevalence of smoking is lower among asthmatics than
among non-asthmatics and asthmatics smoke fewer cigarettes/day and have a lower
level of addiction. There are no differences in age of or reasons for starting to
smoke. Asthmatics have fewer smoking friends than do non-asthmatics and non
smoking asthmatics have fever still. the desire to quit smoking is high in both
groups.
PMID- 10782265
TI - [High prevalence of long-term domiciliary oxygen therapy with a low percentage of
inappropriate prescription in the Madrid health care area. Evaluation of the
correct use].
AB - The efficacy of long-term domiciliary oxygen therapy (DOT) has been confirmed in
patients who comply with guidelines; however, the prevalence in different
populations varies greatly although no satisfactory explanation has been found
for this. OBJECTIVES: To assess the prevalence of inappropriate use of DOT in the
health care area of the Community of Madrid, where demographic and health care
features are well-defined. MATERIAL AND METHODS: Descriptive, transversal
population study enrolling all patients with DOT in our health care area over a
period of one year (May 1995 to Mayo 1995). Inappropriate use was defined as
characterized by at least one of the following conditions: inappropriate
prescription, poor compliance or continued smoking. RESULTS: The total number of
patients was 860, the prevalence of DOT use being 178.3 per 100,000 inhabitants
for the period. Ninety-three refused to participate. Nearly half the patients ha
been using oxygen therapy for over two years. Seventy percent were followed by
pneumologists. Seventy-four percent were men, with a mean age of 70 +/- 9 yr.
Criteria for prescription were not followed in 9.7% of the cases. Chronic
obstructive pulmonary disease was the reason for prescribing DOT in 59.7%. Use
was appropriate in 719 cases. Use was inappropriate in 337 (46.9%), related to
poor compliance in 60.5%, current smoking in 11%, and inappropriate prescription
in 5.6% and for more than one criterion in 22.8%. CONCLUSIONS: The prevalence of
DOT use in our health care area is very high. The percentage of inappropriate use
is high, although similar to that of other populations, and highly related to
poor compliance. The percentage of inappropriate prescription is low. Possible
reasons for the high prevalence are discussed.
PMID- 10782266
TI - [Functional assessment of respiratory muscles].
PMID- 10782267
TI - [Is tuberculosis contagious or not?].
PMID- 10782268
TI - [Bilateral lung reduction by video-assisted thoracoscopy in a patient with non
bullous pulmonary emphysema and laryngeal neoplasia].
AB - Lung reduction has been show to be a promising treatment for the final phases of
non-bullous pulmonary emphysema. The role of video-assisted thoracoscopy (VAT) in
this disease has not yet been established. We report a case of bilateral non
bullous pulmonary emphysema in which transplantation was ruled out because of
laryngeal neoplasm treated three months earlier. Using VAT, we performed
bilateral lung reduction in the apical zones with good therapeutic results. We
find that in patients reduction by VAT, although not a curative treatment, leads
to immediate postoperative improvement in lung function and dyspnea, and does not
exclude the possibility of later performing lung transplantation.
PMID- 10782269
TI - [Mediastinal cystic lymphangioma].
PMID- 10782270
TI - [Migratory pulmonary infiltrates due to bronchiolitis obliterans organizing
pneumonia after radiotherapy].
PMID- 10782271
TI - [Tobacco and advertising].
PMID- 10782273
TI - [Sarcoidosis with the 25-year course].
PMID- 10782272
TI - [Treatment of COPD in primary care].
PMID- 10782274
TI - [Physician workforce and population aging in Switzerland].
AB - The number of physicians in private practice per 100,000 populations will raise
to 210 in the year 2005 and to 235-265 in the year 2020, from 187 in 1998. The
feeling of manpower surplus is spreading in Switzerland and some commentators are
voicy as concerns aggravated oversupply in the future. During the period 1990
2020, the Swiss population will increase +12% but the population aged 65 and over
will increase +57%. Even if the elderly in the forthcoming decades will be in
better health than their today's counterparts, most probably the demand for
health services will increase. Social change, medical technology progress and
growth in the population-doctor ratio itself will fuel the process.
PMID- 10782275
TI - [Health expenditures in Spain at the dawn of the 3d millennium].
AB - In 1997, per capita health expenditures reached in Spain 805 Euros as compared to
1146 Euros in the entire European Union. In terms of percent GDP, Spanish health
expenditures amounted to 7.4 percent, as compared to 7.9 in the European Union.
About 80% of Spanish health expenditures are public-funded. Since 1993 onwards,
there is a political consensus for keeping at the same pace health expenditures
increase and GDP growth. However it is not certain that such a consensus can be
maintained, as trade unions are increasingly voicy for a strong growth of
salaries in the public sector. There will be also pressure on the demand side,
both in the short term (the Spanish people are increasingly expecting to raise
their consumption of health services to the level of other European countries)
and in the long run (impact of population aging).
PMID- 10782276
TI - [The risks of good health in France in the year 2020].
AB - Since 1995 onwards, health cost containment is the order of the day in France.
Successively, the Right and the Left were implementing strong policies aimed at
curbing hospital costs, controlling drug prescriptions, promoting early
retirement of practicing doctors.... As expected, all these actions have
encountered hard resistances from health professionals (As a matter of fact, the
demand side was not affected by cost containment policies). The inertia of all
the system and the resistance from health personnel made it clear that cost
containment measures will obtain a significant impact only after 2003 or 2005.
Precisely, at that date, or some years later, the medical profession will start a
sharp decrease of its numbers as the graduate-boom cohorts of the period 1975
1990 will arrive at retirement age. On the demand side, the French population
will accelerate its aging process as the baby-boomers born during the period 1945
1965 will reach successively their 60th anniversary. In other words, the decade
2010-2020 will see a sharp growth of the demand for health services and a
decrease in the supply. As cost containment is a painful and long-harvesting
process, the health authorities of the decade 2010-2020 will probably not let
"the horse run freely again". Most probably, supply of health care will be kept
under strict control. Will France then adopt the British model (health
expenditures kept at low level and queuing for care)? Or will the nation be
innovative enough to invent a new model for its health system?
PMID- 10782277
TI - [Physician workforce and population aging in Greece].
AB - In 1996, there were 41,511 medical doctors in Greece i.e. 340 doctors per 100,000
population. Recent forecasts showed that in 2001, there would be 46,558 doctors
in the country i.e. 422 doctors per 100,000 population. There is currently no
numerous clauses at the start of medical training. Medical workforce growth is
fueling increase in health expenditures and the underground activities of
doctors. In the upcoming decades, population aging will accelerate the growth of
health expenditures. All these moves will no doubt impose upon a restructuring of
all the health care system.
PMID- 10782278
TI - [Trends in supply and demand for physicians in Belgium].
AB - Belgium is experiencing a strong medical workforce oversupply. At the end of
1998, there were 345 active physicians per 100,000 population and the ratio is
even higher in the francophone area of the country (433 active physicians per
100,000 population). Health expenditures are steadily raising. A numerous clauses
system was established in the medical schools in 1996 but its will not affect the
annual number of graduates before 2004. During the next two decades, for various
reasons, population aging will have only a slight effect on the growth of health
care expenditures. However, most probably, more doctors will be needed. Given the
current manpower oversupply, such forecasts are not easily accepted.
PMID- 10782279
TI - Novel practical synthesis of Kdn2en and its C-4 nitrogen-modified derivatives.
AB - A practical synthesis of Kdn2en and 4-amino-4-deoxy-Kdn2en has been achieved via
a key intermediate, methyl 4,5,7,8,9-penta-O-acetyl-2,6-anhydro-3-deoxy-D-glycero
D-galacto-non-2- enonate, which has been prepared from Kdn in three steps in 91%
overall yield.
PMID- 10782281
TI - Synthesis of ethyl 2-acetamido-6-S-(5-amino-5-deoxy-beta-D- arabinopyranosyl)-2
deoxy-1,6-dithio-beta-D-glucopyranoside: a sulfur-linked 5-amino-5
deoxyglycopyranosyl disaccharide.
AB - A novel pseudo-disaccharide having an imino sugar residue at the non-reducing
end, namely, a sulfur-linked 5-amino-5-deoxyglycopyranosyl disaccharide, which is
a potential specific inhibitor for glycosidases that recognize not only the
glycosidic linkage but also the aglycone moiety, was synthesized. Glycosidation
of N-Boc-5-amino-5-deoxy-D-arabinose with ethyl 2-acetamido-3,4-di-O-acetyl-2
deoxy-1,6-dithio-beta-D- glucopyranoside in the presence of TsOH gave exclusively
the corresponding 1,2-cis-linked thioglycoside. The interglycosidic linkage
proved stable enough under conditions for the deprotection of the N-Boc group
with TFA. This pseudodisaccharide was unstable at pH > 5, but stable at lower pH.
The sulfur-linked 5-amino-5-deoxyglycopyranosyl disaccharide was shown to be
formed from 5-amino-5-deoxy-D-arabinose and ethyl 2-acetamido-2-deoxy-1,6-dithio
beta-D-glucopyranoside in an acidic buffer solution.
PMID- 10782280
TI - Synthesis of 4-nitrophenyl beta-D-fucofuranoside and beta-D-fucofuranosyl-(1-->3)
D-mannopyranose: modified substrates for studies on catalytic requirements of
beta-D-galactofuranosidase.
AB - Syntheses of 4-nitrophenyl beta-D-fucofuranoside (6) and beta-D-fucofuranosyl-(1-
>3)-D-mannopyranose (10) are reported. These compounds, as analogues of
galactofuranosides, were used for studying the influence of the hydroxyl group at
C-6 in the interaction of the substrate with beta-D-galactofuranosidase. For the
synthesis of the fucofuranosides, 2,3,5-tri-O-benzoyl-6-bromo-6-deoxy-D-galactono
1,4-lactone (1) was the key intermediate, which upon reduction of the lactone
group with diisoamylborane, acetylation of the anomeric hydroxyl group, and
catalytic hydrogenolysis of the bromine at C-6, led to 1-O-acetyl-2,3,5-tri-O
benzoyl-alpha,beta-D-fucofuranose (4), a convenient derivative for the
preparation of fucofuranosides. Compound 4 was glycosylated in the presence of
SnCl4, either with 4-nitrophenol for the preparation of 6, or with 2,5,6-tri-O
benzoyl-D-mannono-1,4-lactone (7), for the synthesis of disaccharide 10, via the
glycosyl-aldonolactone approach. The synthetic route developed for the beta-D
fucofuranosides is simple and efficient. Compound 6 was not hydrolyzed by
incubation with the exo beta-D-galactofuranosidase from Penicillium fellutanum,
showing that HO-6 is essential for interaction of the substrate with the enzyme.
PMID- 10782282
TI - Synthesis of a tetrasaccharide representing a minimal epitope of an
arabinogalactan.
AB - The hydrophobic alkyl chain-containing tetrasaccharide, dodecyl beta-D
galactopyranosyl-(1-->6)-beta-D-galactopyranosyl-(1-->6)-[alpha-L -
arabinofuranosyl-(1-->2)]-beta-D-galactopyranoside, was synthesized efficiently
using a convergent strategy. In coupling reactions, protected
trichloroacetimidates proved to be better donors than their corresponding
bromides in the preparation of the dodecyl disaccharide and trisaccharide.
Zemplen deacylation provided the target tetramer in good overall yield.
PMID- 10782283
TI - 3,4-anhydro-1,2-O-isopropylidene-beta-D-tagatopyranose and 4,5-Anhydro-1,2-O
isopropylidene-beta-D-fructopyranose.
AB - 3,4-Anhydro-1,2-O-isopropylidene-beta-D-tagatopyranose (8) and 4,5-anhydro-1,2-O
isopropylidene-beta-D-fructopyranose (10) have been prepared by treatment of 3,5
di-O-acetyl-1,2-O- isopropylidene-4-O-toluene-p-sulfonyl-beta-D-fructopyranose
with methanolic sodium methoxide. The structures of 8 and 10 were assigned by 1H
and 13C NMR spectroscopy and that of 10 by X-ray crystallography; both exist in
half-chair conformations. Compounds 8 and 10 interconvert in aqueous sodium
hydroxide, giving a ratio of 1:2 at equilibrium. The monoacetates of 8 and 10 (5
O-acetyl-3,4-anhydro-1,2-O-isopropylidene-beta-D-tagatopyranose and 3-O-acetyl
4,5-anhydro-1,2-O-isopropylidene-beta-D-fructopyranose) undergo stereospecific
epoxide ring opening in 80% acetic acid to give mainly the axial monoacetates 5-O
acetyl-1,2-O-isopropylidene-beta-D-fructopyranose and 4-O-acetyl-1,2-O
isopropylidene-beta-D-tagatopyranose, respectively.
PMID- 10782284
TI - Galactosyl transfer ability of beta-(1-->4)-galactosyltransferase toward 5a-carba
sugars.
AB - Bovine beta-(1-->4)-galactosyltransferase was assayed with a series of 5a-carba
sugars, i.e., sugar analogues in which the ring oxygen of pyranose is replaced by
a methylene group. The analogues are 5a-carba-sugar of 2-acetamido-2-deoxy-alpha
DL-galactopyranose, both alpha and beta anomers of 2-acetamido-2-deoxy-DL
glucopyranose (5a-carba-DL-GlcNAc), and 2-acetamido-2-deoxy-DL-mannopyranose. Of
these analogues, both alpha and beta anomers of 5a-carba-DL-GlcNAc act as an
acceptor. Enzymatic synthesis using the alpha and beta anomers of 5a-carba-DL
GlcNAc afforded the corresponding D-Gal-beta-(1-->4)-5a-carba-alpha-D-GlcNAc and
D-Gal-beta-(1-->4)-5a-carba-beta-D-GlcNAc on a practical scale, and these
structures were confirmed by NMR spectroscopy. These results indicate that the
ring oxygen atom in the 5a-carba-D-GlcNAc is not used for specific recognition by
bovine beta-(1-->4)-galactosyltransferase.
PMID- 10782285
TI - Effects of various saccharides on cycloinulo-oligosaccharide fructanotransferase
reaction: production of beta-inulotriosyl-alpha-D-mannopyranoside and 1-O-beta
inulotriosyl-alpha-L-sorbopyranose.
AB - The effects of various saccharides on the reaction of cycloinulo-oligosaccharide
fructanotransferase with cycloinu-lohexaose were examined. In addition to beta-D
fructofuranosides and methyl alpha-D-glucopyranoside, D-mannose and L-sorbose
were found to be effective acceptors in the reactions, and they enhanced the
hydrolytic activity as effectively as methyl alpha-D-glucopyranoside. Hetero
tetrasaccharides were isolated as the major transfer products from both reaction
mixtures. The isolates were identified by NMR spectroscopy as beta-inulotriosyl
alpha-D-mannopyranoside and 1-O-beta-inulotriosyl-alpha-L-sorbopyranose. Methyl
beta-D-glucopyranoside was slightly effective and methyl alpha-D-mannopyranoside
was not effective at all as the acceptor, but these saccharides strongly enhanced
the hydrolytic activity. D-Glucosamine inhibited the enzyme activity.
PMID- 10782286
TI - A new bioactive steroidal saponin, furcreastatin, from the plant Furcraea
foetida.
AB - Microbial and plant secondary metabolites were screened for compounds that are
selectively cytotoxic to mutant p53-expressing mouse fibroblasts. As a result,
furcreastatin, a novel steroidal saponin, was isolated from an EtOH extract of
the leaves of Furcraea foetida. Furcreastatin consisted of hecogenin as the
aglycone and a hexasaccharide containing D-galactose, L-rhamnose and four D
glucose residues. The structure was determined to be (3 beta,5 alpha,25R)- 3
hydroxyspirostan-12-one 3-O-[alpha-L-Rhap-(1-->4)-beta-D-Glcp-(1-->3)-?beta-D
Glcp-(1-->3) -beta-D- Glcp-(1-->2)?-beta-D-Glcp-(1-->4)-beta-D-Galp] by extensive
NMR spectroscopic studies. Furcreastatin decreased the viability of mutant p53
over-expressing cells with an ED50 of 4.0 micrograms/mL, and decreased that of
the parental cell-line with an ED50 of 9.6 micrograms/mL.
PMID- 10782287
TI - Evidence for covalent binding between copper ions and cyclodextrin cavity: a
vibrational circular dichroism study.
AB - Vibrational absorption and circular dichroism (VCD) spectra were obtained for
parent cyclodextrins, hydroxyl deuterated alpha-cyclodextrin, cyclodextrin-copper
complexes, and for the cyclodextrin inclusion complexes with Methyl Orange,
methyloxirane, 1-propanol, and substituted cyclohexanones, in the solution phase.
Changes in the VCD spectra, reflecting perturbations of cyclodextrin cavity, were
found in the case of an inclusion complex with Methyl Orange, but for the
remaining inclusion complexes measurable changes in VCD were not found.
Significant changes observed in the VCD spectra of cyclodextrin-copper complexes
suggest that the covalent binding of copper ions to the hydroxyl groups of
cyclodextrin is involved.
PMID- 10782288
TI - Homonojirimycin analogues and their glucosides from Lobelia sessilifolia and
Adenophora spp. (Campanulaceae).
AB - 2,6-Dideoxy-7-O-(beta-D-glucopyranosyl) 2,6-imino-D-glycero-L-gulo- heptitol (7-O
beta-D-glucopyranosyl-alpha-homonojirimycin, 1) was isolated from the 50%
methanol extract of the whole plant of Lobelia sessilifolia (Campanulaceae),
which was found to potently inhibit rice alpha-glucosidase. Adenophorae radix,
roots of Adenophora spp. (Campanulaceae), yielded new homonojirimycin
derivatives, adenophorine (2), 1-deoxyadenophorine (3), 5-deoxyadenophorine (4),
1-C-(5-amino-5-deoxy-beta-D-galactopyranosyl)butane (beta-1-C-butyl
deoxygalactonojirimycin, 5), and the 1-O-beta-D-glucosides of 2 (6) and 4 (7), in
addition to the recently discovered alpha-1-C-ethylfagomine (8) and the known 1
deoxymannojirimycin (9) and 2R,5R-bis(hydroxymethyl)-3R,4R- dihydroxypyrrolidine
(DMDP, 10). Compound 4 is a potent inhibitor of coffee bean alpha-galactosidase
(IC50 = 6.4 microM) and a reasonably good inhibitor of bovine liver beta
galactosidase (IC50 = 34 microM). Compound 5 is a very specific and potent
inhibitor of coffee bean alpha-galactosidase (IC50 = 0.71 microM). The glucosides
1 and 7 were potent inhibitors of various alpha-glucosidases, with IC50 values
ranging from 1 to 0.1 microM. Furthermore, 1 potently inhibited porcine kidney
trehalase (IC50 = 0.013 microM) but failed to inhibit alpha-galactosidase,
whereas 7 was a potent inhibitor of alpha-galactosidase (IC50 = 1.7 microM)
without trehalase inhibitory activity.
PMID- 10782289
TI - Structure of the O-specific polysaccharide of Proteus mirabilis O11, another
Proteus O-antigen containing an amide of D-galacturonic acid with L-threonine.
AB - The O-specific polysaccharide of Proteus mirabilis O11 was studied by sugar
analysis, Smith degradation, 1H and 13C NMR spectroscopy, including two
dimensional COSY, TOCSY, NOESY, and 1H-detected 1H, 13C HMQC experiments. The
following structure of a pentasaccharide repeating unit of the polysaccharide was
established: [formual: see text] where D-GalA6LThr is N-(D-galacturonoyl)-L
threonine. ELISA with anti-P. mirabilis O11 serum showed that D-GalA6LThr is of
minor importance for manifesting the O11 immunospecificity.
PMID- 10782290
TI - Separation and structural analysis of some saponins from Quillaja saponaria
Molina.
AB - A fraction of saponins from Quillaja saponaria Molina, QH-B, was fractionated by
consecutive separations on three different reverse-phase HPLC systems. Eight
compounds were isolated and the structures of these were elucidated mainly by
sugar analysis and NMR spectroscopy. The structures consisted of a quillaic acid
substituted with two different trisaccharides at C-3, beta-D-Galp-(1-->2)-[alpha
L-Rhap-(1-->3)]-beta-D-GlcpA and beta-D-Galp-(1-->2)-[beta-D-Xylp-(1-->3)]-beta-D
GlcpA, and a tetra- or pentasaccharide at C-28, beta-D-Xylp-(1-->4)-[beta-D-Glcp
(1-->3)]-alpha-L-Rhap-(1--> 2)-beta-D-Fucp and beta-D-Apif-(1-->3)-beta-D-Xylp-(1
->4)-[beta-D-Glcp-(1-->3) ]-alpha-L- Rhap-(1-->2)-beta-D-Fucp. These compounds
were further substituted with an acyl group either at O-3 or O-4 of the fucose
residue, which is the sugar linked to C-28 of the quillaic acid.
PMID- 10782291
TI - Structures of the O21 and O25 antigens of Stenotrophomonas maltophilia.
AB - The O-specific side-chain polymers from Stenotrophomonas maltophilia serogroups
O21 and O25 were isolated from the lipopolysaccharides of the reference strains.
The O21 polymer contained D-arabinose, 2-amino-2-deoxy-D-glucose and 2-amino-2
deoxy-D-galactose in equal proportions. Methylation analysis and NMR spectroscopy
showed that the polysaccharide is based on a branched trisaccharide repeating
unit of the structure shown below. The O25 polymer is linear with a disaccharide
repeating unit identical to that forming the backbone of the O21 polymer.
PMID- 10782292
TI - The structure of the O-specific polysaccharide of Escherichia coli O117:K98:H4.
AB - The primary structure of the O-antigen of Escherichia coli O117 was shown by
monosaccharide analysis, methylation analysis, and by 1D and 2D 1H and 13C NMR
spectroscopy to be composed of linear pentasaccharide repeating units with the
structure: -->3)-alpha-D-GalpNAc-(1-->4)-beta-D-GalpNAc-(1-->3)-alpha-L-Rhap- (1-
>4)- alpha-D-Glcp-(1-->4)-beta-D-Galp-(1-->
PMID- 10782293
TI - N-linked oligosaccharide structures in the diamine oxidase from porcine kidney.
AB - Structures of the N-linked glycans released from porcine kidney diamine oxidase
(DAO) were characterized utilizing various analytical techniques, including
matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
(MALDI/TOF-MS), high-performance capillary electrophoresis (HPCE), and high-pH
anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The
oligosaccharide sequences present in DAO were conclusively determined using
specific exoglycosidases in conjunction with MALDI/TOF-MS. The structures found
in the glycoprotein are primarily linear, di-, or tribranched fucosylated complex
type. MS analysis of the esterified N-glycan pool derived from DAO indicated the
presence of several di- and trisialylated structures.
PMID- 10782294
TI - Characterization of pectin, flash-extracted from orange albedo by microwave
heating, under pressure.
AB - Pectin was acid extracted from orange albedo by microwave heating under pressure.
Extraction times ranged from 2.5 to 8 min. Solubilized pectin was characterized
for molar mass (M), rms radius of gyration (Rg) and intrinsic viscosity [eta] by
HPSEC with online light scattering and viscosity detection. M, Rg and [eta] all
decreased with increasing extraction time. Nevertheless, at heating times of 2.5
and 3.0 min, M, Rg and [eta] were significantly higher than a commercial citrus
pectin when the albedo:solvent ratio was 1:25 (w/v). At the heating time of 2.5
min Mw was 3.6 x 10(5), Rgz was 38 nm and [eta]w was 10.8 dL/g. Chromatography
revealed that solubilized pectin distributions were bimodal in nature and that
the low-molar-mass fraction increased at the expense of the high-molar-mass
fraction with increasing extraction time. Scaling law exponents revealed that the
high-molar-mass fraction was extremely compact in shape, whereas the low-molar
mass fraction was more asymmetric in shape. Possibly these results indicated that
at short extraction times, pectin was solubilized as compact aggregated network
structures that were broken down to their more asymmetric components with
increased heating times.
PMID- 10782295
TI - Studies on the primary structure of short polysaccharides using SEC MALDI mass
spectroscopy.
AB - The introduction of size-exclusion chromatography (SEC) analysis of
polysaccharides prior to MALDI mass spectroscopy accounts for the determination
of the molecular mass of the repeating unit when neutral homopolymers are
investigated. In the case of natural polysaccharides characterised by more
complicated structural features (presence of non-carbohydrate substituents,
charged groups, etc.), this mass value usually is in agreement with more than one
sugar composition. Therefore, it is not sufficient to give the correct
monosaccharidic composition of the polysaccharide investigated. To solve this
problem, MALDI spectra were recorded on the permethylated sample and post-source
decay experiments were performed on precursor ions. In this way, the composition
(in terms of Hex, HexNAc, etc.), size and sequence of the repeating unit were
determined.
PMID- 10782296
TI - The use of NMR residual dipolar couplings in aqueous dilute liquid crystalline
medium for conformational studies of complex oligosaccharides.
AB - C-H dipolar coupling values were measured for a natural-abundance sample of the
pentasaccharide beta-D-Galp-(1-->3)-[alpha-L-Fucp-(1-->4)]-beta-D-GlcNAcp-(1 -
>3)-beta-D- Galp-(1-->4)-beta-D-Glcp ('lacto-N-fucopentaose 2') (LNF-2), in a
7.5% solution of dimyristoyl phosphatidylcholine-dihexanoyl phosphatidylcholine
bicelle liquid crystals oriented in the NMR magnetic field. Interpretation of the
dipolar coupling data and NOE confirms the conformational model for the Lewis(a)
trisaccharide epitope based on NOE, molecular dynamics simulations, and scalar
coupling data and provided new structural information for the remaining residues
of the pentasaccharide. Since residual dipolar coupling provides information on
long-range order, it is a valuable complement to other types of NMR data such as
NOE and scalar coupling for exploring conformations of complex oligosaccharides.
PMID- 10782297
TI - Degree of acetylation of heteropolysaccharides.
AB - The acetyl groups in polysaccharides and glycoproteins have been determined using
4 N HCl at 120 degrees C for acid hydrolysis. Acetic acid and hexosamine were
determined by high-performance cation-exchange chromatography with UV detection
and high-performance anion-exchange chromatography with pulsed amperomeric
detection, respectively. The method compares well with other procedures and shows
an additional advantage of being able to analyze for hexosamine in the same
hydrolyzate, thus permitting the degree of acetylation of hexosamine-containing
biopolymers to be determined directly without correction for additional
components in the material of interest.
PMID- 10782298
TI - Structure-properties relationship in cross-linked high-amylose starch for use in
controlled drug release.
AB - Cross-linked high-amylose starch (CLHAS), obtained by high-amylose starch cross
linking, was recently introduced as an excipient (Contramid) for monolithic
dosage forms that are able to control drug release over 18-24 h. These control
properties are related to tablet swelling and are strongly dependent on the
degree of the cross-linking of CLHAS. The permeability of solutes through CLHAS
hydrogels depends on the chemical structure of the polymer. The aim of this study
was to obtain a better understanding of how modifications in CLHAS molecular
structures at the level of long-range and short-range order during the cross
linking and processing conditions relate to the release properties of the CLHAS
matrices. Structural parameters such as crystallinity contribute significantly to
the physical and mechanical aspects of starch products. X-ray diffractometry,
FTIR spectroscopy, dissolution tests in vitro, and mechanical hardness (of dry
tablets) were found to be sensitive to the cross-linking degree (cld) variation.
Best release properties and highest mechanical hardness were obtained from CLHAS
matrices with low-to-moderate crystallinity, where the V- and the B-type
structures coexist with amorphous regions. X-ray and FTIR profiles of dry CLHAS
powders were found to be predictive for release properties of CLHAS tablets.
PMID- 10782300
TI - Effect of stereochemistry on the anti-freeze characteristics of carbohydrates. A
thermal study of aqueous monosaccharides at subzero temperatures.
AB - Thermal behavior at subzero temperatures has been investigated for aqueous
solutions of various monosaccharides. The heat of fusion of ice measured with
differential scanning calorimetry has given linear plots against sugar
concentration (wt.%), from which the amount of unfrozen water, Uw, has been
determined for each monosaccharide. The results for Uw are analyzed by employing,
as a measure of hydration characteristics, known physico-chemical properties of
aqueous monosaccharides, such as partial molar compressibilities, etc. It was
revealed that the anti-freeze characteristics of carbohydrates depend on their
stereochemistry. More water remains unfrozen in the aqueous solutions of
carbohydrates having poorer compatibility with the three-dimensional hydrogen
bond network of water. Monosaccharides studied can be subdivided into three
groups according to the extent of the anti-freeze effect. These results are
rationalized in terms of a modified stereospecific hydration model.
PMID- 10782299
TI - Synthesis of homogeneous glycopeptides and their utility as DNA condensing
agents.
AB - Two glycopeptides were synthesized by attaching purified glycosylamines (N
glycans) to a 20 amino acid peptide. Triantennary and Man9 Boc-tyrosinamide N
glycans were treated with trifluoroacetic acid to remove the Boc group and expose
a tyrosinamide amine. The amine group was coupled with iodoacetic acid to produce
N-iodoacetyl-oligosaccharides. These were reacted with the sulfhydryl group of a
cysteine-containing peptide (CWK18), resulting in the formation of glycopeptides
in good yield that were characterized by 1H NMR and ESIMS. Both glycopeptides
were able to bind to plasmid DNA and form DNA condensates of approximately 110 nm
mean diameter with zeta potential of +31 mV. The resulting homogeneous
glycopeptide DNA condensates will be valuable as receptor-mediated gene-delivery
agents.
PMID- 10782301
TI - Crystal structures and thermotropic properties of alkyl alpha-D-glucopyranosides
and their hydrates.
AB - Thermotropic properties and crystal structures of alkyl alpha-D-glucopyranosides
and their hydrates were estimated by X-ray, DSC and thermogravimetric
measurements (TGA). Monohydrates rapidly lose their crystal water several degrees
below the melting point of the anhydrous glucopyranosides. The melting points of
the monohydrates measured in DSC pressure cells (chain length longer than seven)
are lower, and the clearing points higher than those of the anhydrous glucosides.
Layer distances of smectic and crystalline phases of anhydrous compounds were
established. Melting points, densities and layer distances of the crystalline
anhydrous glucopyranosides display strong even-odd effects. The strong decrease
of these effects in the case of the monohydrates can be elucidated by the results
of X-ray crystal structure analysis.
PMID- 10782302
TI - Stereoselective synthesis of C-[2-S-(p-tolyl)-2-thio-beta-D-galactopyranosyl]
compounds using the reaction of TolSCl adducts of D-galactal with C-nucleophiles.
AB - Pyranosyl chlorides prepared in situ from tri-O-benzyl-D-galactal and TolSCl
react with silyl enol ethers, allyltrimethylsilane, and vinyl ethers to give a
mixture of beta-C-galacto and alpha-C-talopyranosides in a ratio of 19:1.
PMID- 10782303
TI - Synthesis of methyl alpha-L-vancosaminide.
AB - The synthesis of methyl alpha-L-vancosaminide from di-O-acetyl-L-rhamnal is
described. The allylic alcohol methyl 2,3,6-trideoxy-3-C-methyl-alpha-L-threo-hex
2-enopyranoside was prepared from the glycal, 1,5-anhydro-1,2,6-trideoxy-3-C
methyl-L-ribo-hex-1-enitol, and converted to its N,N-dimethylisourea derivative.
The cis amino alcohol functionality in vancosamine was introduced by the
electrophilic cyclization of the isourea, followed by hydrolysis of the resulting
oxazoline.
PMID- 10782304
TI - Efficient syntheses of 1-bromodeoxy-, 1-azidodeoxy- and 1-aminodeoxypentitols
from unprotected D-pentono-1,4-lactones.
AB - The reduction of unprotected 5-bromo-5-deoxy-D-ribono, D-arabinono and D-xylono
1,4-lactones was achieved with NaBH4 in water-EtOH. The corresponding 1-bromo-1
deoxypentitols were isolated after acetylation in good overall yields (60-90%). 1
Azido-1-deoxypentitols were obtained quantitatively either by nucleophilic
substitution by azide ion and deacetylation of the corresponding
monobromopentitols or by reduction of the corresponding 5-azido-5-deoxy-D-pentono
1,4-lactones. The reduction of the monoazidopentitols by catalytic hydrogen
transfer gave the monoaminopentitol analogues in quantitative yield.
PMID- 10782306
TI - 1,2-di-O-acetyl-5-O-benzoyl-3-deoxy-L-erythro-pentofuran ose, a convenient
precursor for the stereospecific synthesis of nucleoside analogues with the
unnatural beta-L-configuration.
AB - The title compound 1,2-di-O-acetyl-5-O-benzoyl-3-deoxy-L-erythro-pentofuranose
(5), a useful precursor for the stereospecific synthesis of beta-L-nucleoside
analogues as potential antiviral agents, has been synthesised by a multi-step
reaction sequence from L-xylose with a 38% overall yield. The preparation
involved conversion of L-xylose to 1,2-O-isopropylidene-alpha-L-xylofuranose
which, upon selective 5-O-benzoylation and subsequent radical deoxygenation,
provided the protected 3-deoxy sugar derivative. Finally, cleavage of the
acetonide group gave the resulting 5-O-benzoyl-3-deoxy-L-erythro-pentose which
was acetylated to afford crystalline alpha,beta-5.
PMID- 10782305
TI - Synthesis of 6,7-dideoxy-7-isothiocyanatoheptoses: stable fully unprotected
monosaccharide isothiocyanates.
AB - Methyl 6,7-dideoxy-7-isothiocyanato-alpha-D-gluco (manno)(galacto)
heptopyranosides have been synthesized in four steps by homologation of the
respective methyl hexopyranosides via the corresponding
heptopyranosydurononitriles. Neither intra- nor intermolecular thiocarbamate
formation was observed, even under rather strenuous acidic or basic conditions.
The reducing derivative 6,7-dideoxy-7-isothiocyanato-alpha-D-gluco-heptopyranose
was also a stable compound in aqueous solution in the absence of base. Formation
of a six-membered intramolecular cyclic thiocarbamate was achieved in DMF
solution in the presence of triethylamine. The title compounds are the first
examples of stable fully unprotected monosaccharide isothiocyanates.
PMID- 10782307
TI - Synthesis, X-ray structure and high-resolution NMR spectroscopy of methyl 3-azido
2,3-dideoxy-alpha-D-arabino-hexopyranoside.
AB - The synthesis, crystal structure data and 1H and 13C NMR spectroscopy of methyl 3
azido-2,3-dideoxy-alpha-D-arabino-hexopyranoside (5b) is reported. This compound
adopts the 4C1 conformation. Hydrogen-bonded molecules of 5b form helices around
the crystallographic 4(1) axis.
PMID- 10782308
TI - Structure of the O-chain polysaccharide of the lipopolysaccharide of Xanthomonas
campestris pv. manihotis GSPB 2755 and GSPB 2364.
AB - The O-chain polysaccharide of the lipopolysaccharide of Xanthomonas campestris
pv. manihotis strains GSPB 2755 and GSPB 2364 was studied by sugar and
methylation analyses and 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY,
NOESY, and H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC)
experiments. The polysaccharide was found to contain L-rhamnose and L-xylose in
the ratio 3:1, and the following structure of the tetrasaccharide repeating unit
was established: [formula: see text]
PMID- 10782309
TI - Crystal structure of hexakis(2,6-di-O-methyl)-alpha-cyclodextrin-acetonitrile
dihydrate: a channel formed by methyl groups harbors a chain of five partially
occupied water sites.
AB - Hexakis(2,6-di-O-methyl)-alpha-cyclodextrin (DIMEA) crystallizes from 1:1 water
acetonitrile as DIMEA-acetonetril-dihydrate in the orthorhombic space group
P2(1)2(1)2(1), unit cell dimensions a = 14.2775(5), b = 15.7312(5), c =
31.1494(11) A. Refinement of the structure against 5540 X-ray diffraction data
converged at an R factor of 0.083. The macrocycle exhibits a 'round' conformation
and is stabilized by intramolecular, interglucose O-3-H(n)...O-2(n + 1) and C-6
H(n)...O-5(n + 1) hydrogen bonds. Acetonitrile is included in the central cavity
of DIMEA and held in position by C-5-H...N interactions. The two water molecules
in the asymmetric units are distributed over six sites. One is fully occupied due
to hydrogen bonding to O-3 groups of two symmetry-related DIMEA molecules,
whereas the five remaining sites show occupancies between 0.15 and 0.25. These
sites are in hydrogen bonding contact with O...O distances between 2.59 and 3.50
A and are located in infinite, hydrophobic channels parallel to the alpha-axis,
which are coated with methyl groups of symmetry-related DIMEA.
PMID- 10782310
TI - Foundation science for medicine in the 21st century. Proceedings of a workshop.
Hamilton, Ontario, Canada. May 21-23, 1999.
PMID- 10782311
TI - Opening remarks: establishing a scientific foundation for clinical medicine in
the medical curriculum.
PMID- 10782312
TI - A Toronto perspective.
PMID- 10782313
TI - Basic science in medical education.
PMID- 10782314
TI - A new curriculum for the MD degree at the University of Alberta.
PMID- 10782315
TI - Basic science and medical education: dinosaurs, departments and definitions--a
McMaster view.
PMID- 10782316
TI - "Give us good measure": the basic medical sciences and the overloaded curriculum.
PMID- 10782317
TI - The essential role of basic science in medical education: the perspective from
psychology.
PMID- 10782319
TI - The evolution of medicine--a geneticist's point of view.
PMID- 10782318
TI - Physiology: the basic science of health.
PMID- 10782320
TI - Evaluation: the engine that drives us forward--or back.
PMID- 10782321
TI - The challenges of teaching an old subject in a new world--a personal perspective.
PMID- 10782322
TI - Co-tutors in the basis of medicine.
AB - In 1994 the McGill University preclinical medical curriculum was changed from
predominantly didactic, discipline-based instruction to a problem-based approach,
in which the emphasis lies in student discussion of clinical cases with physician
mentors. Although the new curriculum has rapidly gained favour with students, it
has also generated some problems. Foremost among the problems is the diminishing
pool of physician-scientist tutors to facilitate the ever-increasing number of
small-group discussions. From the concepts embodied in educational theories of
situated learning and learning communities, this paper has proposed that
physicians in clinical practice and PhD scientists engaged in biomedical
research, be trained to co-facilitate small-group discussions. Their
complementary knowledge and similar training, should provide a forum through
which medical students will develop clinical reasoning skills, based on sound
scientific knowledge, early in their training.
PMID- 10782323
TI - Presentation and discussion of pharmacology.
PMID- 10782324
TI - Foundation science for medicine: a family medicine perspective.
PMID- 10782325
TI - Integration at the faculty level.
PMID- 10782326
TI - The student's perspective.
PMID- 10782327
TI - Identical germ-line mutations in the triosephosphate isomerase alleles of two
brothers are associated with distinct clinical phenotypes.
AB - We describe here a new stop mutation at triosephosphate isomerase (TPI) position
145 in a Hungarian family for which the first mutation (240 Phe-->Leu) was
published earlier. The entire genomic TPI locus (exons, introns and promoter) was
sequenced and found to be identical in the two compound-heterozygote brothers.
Both brothers have the same well-compensated level of non-spherocytic hemolytic
anemia and very high levels of the TPI substrate dihydroxyacetonephosphate
(DHAP), but only one brother manifests neurologic disorders. Differences in
nonsense-mediated mRNA decay may be at the basis of the differences in phenotype
expression although it cannot be excluded the interaction with a modifier gene.
Based on our earlier results, the development of neurodegeneration may be
decisively modulated by the cellular environment of the mutant proteins
initiating the process of focal apoptosis of neurons in glycolytic, peroxisomal
and prion-induced neurological diseases.
PMID- 10782328
TI - [In vitro androgenesis response of durum wheat disomic substitution].
AB - The variety 'Langdon' and its substitution series were used to evaluate the
effect of each substituted chromosome of the A and B genomes on the in vitro
androgenetic potential. This study showed the implication of chromosomes 1B and
5B in repressing embryogenesis. Genes located on these chromosomes seem to have
an inhibitor effect. The substitution of these chromosomes by their homeologous
ones from the D genome increased the number of embryos while with the presence of
the original genes the number of embryos was less than in the control. Chromosome
5B is also especially involved in the regeneration of green plants. The genetic
control is inhibitory; this explains the difficulty of obtaining good levels of
in vitro androgenesis in durum wheat. In this study no effect of the D genome on
the androgenetic response of the substitution lines was observed.
PMID- 10782329
TI - Time-co-ordinated control of glycogen synthase, protein phosphatase 2A and
protein kinase CK2 during culture growth in Yarrowia lipolytica in relation to
glycogen metabolism.
AB - In the growth course of the lipolytic yeast Yarrowia lipolytica, the activities
of protein phosphatase 2A (PP2A) and glycogen synthase (GS) rise during the
exponential phase and concomitantly glycogen storage occurs in the cells. There
is also an increase in the independence ratio (RI) indicating a shift from an
inactive phosphorylated GS form to an active dephosphorylated GS form. During the
early stationary phase, an increase in protein kinase CK2 (CK2) activity, a
reversion of RI variation and a glycogen content decrease are observed. GS
activity proved to be a good indicator of early culture growth phase. Experiments
carried out with enzymes purified from Y. lipolytica show strong RI variations
upon the action of CK2 and PP2Ac, and 32P incorporation into GS protein through
phosphorylation by CK2. GS activity would be controlled by the sequential action
of PP2A and CK2.
PMID- 10782331
TI - Morphometrics of a neotropical sandfly subspecies, Lutzomyia carrerai thula.
AB - In spite of obvious and frequently observed morphological variation in geographic
populations of sand flies, taxonomists are reluctant to create subspecies. In
doing so they avoid confusion caused by the accumulation of new taxa, but they
also obscure natural processes, some of them related to probable species
emergence. We investigated here how far the partitioning of size, shape and form
could be a relevant technique for exploring early evolutionary processes. We used
a typical case of species, subspecies and cryptic species among three related
taxa: Lutzomyia carrerai, its subspecies L. carrerai thula and L. yucumensis, a
cryptic species of L. carrerai. Univariate and multivariate metric analyses
showed global size differences, even between sympatric taxa (L. carrerai and L.
yucumensis). When allometric effects were discounted, the subspecies L. c. thula
still disclosed important differences from its putative type species, more
pronounced than those existing between the two cryptic species, L. yucumensis and
L. carrerai. A similar result was obtained after removing isometric size. These
analyses question the validity of L. carrerai thula as a subspecies, and show
that morphometrics may be a useful tool for separating simple geographic
variation from evolutionary divergence.
PMID- 10782330
TI - Effects of intracerebroventricular injections of des-His1 (Glu9) glucagon amide
on the regulatory thermogenesis in muscovy ducklings.
AB - Recent investigations have demonstrated a modulatory action of glucagon on
shivering via the central nervous system in ducklings. Such an action could be
mediated by glucagon receptors that have been recently detected in several brain
areas involved in the central control of the involuntary motricity in this avian
species. The present study using des-His1 (Glu9) glucagon amide, was performed to
investigate the central mechanisms of glucagon on shivering. This glucagon analog
was found to be an antagonist of glucagon devoid of adenylate cyclase activity
(GR2) by triggering the breakdown of inositol phosphate (GR1) in mammals
hepatocytes. The intracerebroventricular administration of des-His1 (Glu9)
glucagon amide or glucagon induced a marked inhibition of shivering in ducklings
exposed to cold. It seems likely that GR1 receptors contribute to decreased
shivering in ducklings exposed to cold. Central glucagon or des-His1 (Glu9)
glucagon amide were devoid of thermogenic effect at thermoneutrality.
PMID- 10782332
TI - [Phenotypic convergence among pentacrines Endoxocrinus and Diplocrinus related to
environmental constraints].
AB - Morphological converging and diverging trends are demonstrated using detailed
biometric analyses of the skeleton in pentacrinid populations of the
Diplocrininae subfamily living in tropical western Atlantic and in the Pacific
Ocean. According to environmental data obtained by in situ submersible
observations, water flow characteristics (laminar or with eddies) appear to be
the main factor controlling phenotypes through ontogeny. Evidence of convergence
between different taxa may be explained by ecological niches with eddies.
PMID- 10782334
TI - Extraordinary feeding behaviour in Diptera Sciomyzidae, snail-killing flies.
AB - In the laboratory, the larva of Sepedonella nana, Diptera Sciomyzidae, were only
able to develop at the expense of small aquatic oligochets collected in adult
habitats. Up till now, larval cycles have been elucidated for 38% of the
Sciomyzidae; all these larvae proved to be strict consumers of aquatic or
terrestrial molluscs (including slugs). This specific predation was considered as
a major distinguishing characteristic of Sciomyzidae among Diptera. The unusual
nutritional behaviour of S. nana reported in the present note is in contradiction
with well-established prior knowledge. The species presented all the
characteristics of the family, particularly the ventral arch sclerite present on
the larva cephalopharyngeal skeleton. It was considered as a derived species;
this behaviour, probably of secondary type, revealed new nutritional types for
Afrotropical Sciomyzidae for which the biology of only five species was
elucidated out of about 60 species described.
PMID- 10782333
TI - Phylogenetic relationships in the Ranidae. Independent origin of direct
development in the genera Philautus and Taylorana.
AB - Phylogenetic relationships within a group of Ranidae were studied, particularly
between the genera Philautus and Taylorana, to determine whether their original
reproductive mode (direct development) appeared independently. To study these
relationships, we used the DNA sequences of the 5' end of the gene coding for
mitochondrial ribosome small subunit in 28 species. Parsimony analysis resulted
in two equiparsimonious trees, 867 steps long (CI = 0.382; RI = 0.429). Data
saturation was studied and we applied weighting (weight of 5 for transversions
and 1 for transitions) to enhance the phylogenetic information. The tree we
obtained (2,212 steps long, CI = 0.408; RI = 0.482) is best supported and allows
us to determine clearly that direct development has appeared independently in
Philautus and Taylorana. In addition, it is confirmed that the genus Rana sensu
lato is heterogeneous. The genera Occidozyga and Phrynoglossus form a clade basal
to all the group but this position is not supported. The inclusion of the
Rhacophorinae in the Ranidae is confirmed. Finally, this study confirms that the
relationships within the group Tomopterna sensu Boulenger, 1918 should be re
evaluated.
PMID- 10782335
TI - [Zonation of macrobenthic communities along two bays in an insular coral reef
ecosystem (Moorea, French Polynesia)].
AB - Zonation of macrobenthic communities (corals, algae, molluscs, sponges and
echinoderms) on fringing reefs was investigated in two bays in a coral reef
ecosystem (Moorea, French Polynesia). Species richness, abundance and coral
cover, and species richness of macroalgae increased from the bayhead to the bay
entrance. For molluscs and sponges, no general trend was observed. Species
richness and abundance of echinoderms increased from the head to the entrance of
Opunohu Bay, but this trend was less pronounced in Cook Bay. The gradients
observed for corals, macroalgae and echinoderms were correlated with one or
several of the following abiotic factors: salinity, turbidity, concentration of
silicates in surface waters, and concentrations of organic carbon, carbohydrates
and amino acids in the sediments. These factors are associated with terrestrial
run-off via river discharge that occurs at the bayheads, where the major river is
located. The high degree of confinement in the bayheads allowed the establishment
of only a few tolerant macrobenthic species. Although the low diversity and
abundance of corals and echinoderms seem to be a characteristic of Polynesian
bays, a high diversity of corals can be found in the vicinity of the bayheads in
coral reefs of the western Pacific.
PMID- 10782336
TI - Extensive gene flow within sibling species in the deep-sea fish Beryx splendens.
AB - Molecular markers allow insights into the population biology and ecology of deep
sea organisms, which are usually hardly accessible to direct observation and
poorly known. Such a study was undertaken here for the deep-sea fish Beryx
splendens, a species of growing interest to fisheries. B. splendens populations
were sampled on seamounts and continental margins in the southwestern Pacific
(New Caledonia, New Zealand, southeastern Australia) and in the northeastern
Atlantic. Two hundred and fifty individuals were characterised by their single
strand DNA conformation (SSCP) of a approximately 360-base-pair (bp) fragment of
the mitochondrial cytochrome b gene, amplified by the polymerase chain reaction
(PCR). Two major SSCP haplotypes were observed in New Caledonia, a and w, whose
frequencies were negatively correlated along a north-to-south cline. All SSCP
haplotypes in the total sample were sequenced on 273 bp. The phylogenetic tree of
B. splendens haplotype sequences, rooted by two B. decadactylus sequences, showed
that a and w belong to distinct mitochondrial clades, A and W, which are
separated by approximately 4-6% nucleotide divergence. Thirty individuals from
New Caledonia were characterised by their DNA fingerprint from arbitrary-primed
PCR. The distribution of individual-pairwise similarity indices was strongly
bimodal. The larger similarity values all corresponded to comparisons within a
clade (A or W) while the lower values were all between clades. Therefore, there
was a strict association between the mitochondrial type and the DNA (presumably,
nuclear DNA) fingerprint of an individual. Altogether, these results point to the
existence of two biological species (sp. A and sp. W) within the current taxon B.
splendens. No within-species differentiation was detected at the regional scale
(New Caledonia). A remarkable result is that the three cytochrome b haplotypes of
northeastern Atlantic B. cf. splendens sp. A were also the three commonest in the
southwestern Pacific populations of this species. Such a level of homogeneity in
the distribution of haplotypes suggests there is, or recently has been, gene flow
at the inter-oceanic scale.
PMID- 10782337
TI - [Hybridization and introgression between "full-fledged species". The case of
Parnassius apollo and P. phoebus].
AB - Two butterfly species living in the Alps, Parnassius apollo and P. phoebus,
frequently hybridize in certain localities of this region. The features of this
phenomenon have been previously studied by biometry and starch gel
electrophoresis, but some points remained obscure. We present them in a study
combining results from cellulose acetate electrophoresis and wing pattern
biometry with a determination of the mitochondrial haplotype by a PCR-RFLP
analysis in a sample of butterflies from the southern French Alps. It was already
known that the male hybrids are fecund and thus that interspecific gene exchange
could take place via backcrosses with the parent species. In the present case,
combining the identification of mtDNA with the analysis of nuclear genotypes
allows us to demonstrate that hybridization can involve both sexes of both
species. Moreover, it suggests that at least some female hybrids are not sterile.
The impact of Haldane's rule is therefore not very strong in the present case.
However, although the prerequisites for introgression between the concerned
species are fulfilled, at the level of both nuclear and mitochondrial genomes, no
indication of such a phenomenon could be gathered in the studied sample.
PMID- 10782338
TI - The exoskeleton of bacterial cells (the sacculus): still a highly attractive
target for antibacterial agents that will last for a long time.
AB - Most bacteria are entirely surrounded by a strong cell wall held together by
covalent bonds of strength similar to those holding the atoms in a diamond
together. This exoskeleton is a coat of armor or corset and is usually called a
sacculus. It protects the bacterium from the stresses resulting from the higher
osmotic pressure of the cytoplasm when compared with its environment. This
strategy of constructing an external mechanical support has the weakness that the
wall barrier has to be cleaved and new wall material inserted outside of the cell
proper in order for the bacterium to grow and divide. Because of the unique
chemistry and the necessity of selectively cleaving old stress-bearing wall for
growth, the wall of the bacterial cell has been a key target for chemotherapeutic
treatment of bacterial diseases. Currently, many infectious organisms are
becoming resistant to overused antibiotics. Still the wall is a good target, and
there could possibly be several entirely new classes of antibiotics targeted
toward other parts of wall metabolism and function. The essential autolysins may
be a particularly relevant target. To find chemotherapeutic agents we must use
and extend our present understanding of the structural mechanics of bacterial
wall and their biophysics, biochemistry, and physiology. Moreover, if we use our
knowledge of biophysics/genetics and of the evolution of antibiotic resistance
mutations that occurred millions of years ago, as well as our knowledge of ones
that have arisen recently, quite novel antibiotics may be designed.
PMID- 10782339
TI - Molecular techniques for determining microbial diversity and community structure
in natural environments.
AB - The ability to quantify the number and kinds of microorganisms within a community
is fundamental to the understanding of the structure and function of an
ecosystem. The simple morphology of most microbes provides few clues for their
identification and physiological traits are often ambiguous. In addition, many
organisms resist cultivation, which is essential to their characterization.
Recombinant DNA techniques have provided a means whereby many of the obstacles
associated with cultivation and description can be overcome and subsequently has
allowed many new insights into the complexity of natural microbial communities.
Molecular approaches based on 16S ribosomal RNA (rRNA) sequence analysis allow
direct investigation of the community structure, diversity, and phylogeny of
microorganisms in almost any environment, while quantification of the individual
types of microorganisms or entire microbial communities may be addressed by
nucleic acid hybridization techniques. Furthermore, the use of fluorescently
labeled population-specific rRNA probes allows microscopic examination of
individual cells in complex microbial assemblages as well as their interactions
in situ. In this review, we discuss strategies for characterizing microbial
communities without the need for cultivation.
PMID- 10782340
TI - The role of Candida dubliniensis in oral candidiasis in human immunodeficiency
virus-infected individuals.
AB - There is an increasing interest in non-albicans Candida species because of the
increasing number of fungal infections they cause. Most of these infections can
be found in immunocompromised individuals, especially in those infected with
human immunodeficiency virus (HIV). Candida dubliniensis is a recently identified
yeast, mostly isolated in HIV-positive individuals with oral candidiasis. Candida
dubliniensis is a germ tube- and chlamydospore-form yeast. Thus, it shares
diagnostic characteristics with Candida albicans. Probably, Candida dubliniensis
has been present in the community for a long time and has been misidentified as
Candida albicans. Significant phenotypic characteristics of Candida dubliniensis
(difference in the carbohydrate assimilation profile, difference in colony color
on CHROMagar Candida, and positive tetrazolium test, etc.) have been found, but
none of them seem to be sufficient alone for the definitive identification of the
species. Recently, PCR tests were developed to discriminate Candida albicans from
Candida dubliniensis. However, these prove difficult in the context of routine
mycological diagnostics. Moreover, an increased resistance to antifungal drugs
has been described. This shows the importance of identification of Candida
dubliniensis. To elucidate the current insight into Candida dubliniensis, the
phenotypic and genotypic characteristics as well as the prevalence and the
antifungal drug susceptibilities of this species are discussed from a clinical
standpoint.
PMID- 10782341
TI - The haemocytic origin of lymphoid organ spheroid cells in the penaeid prawn
Penaeus monodon.
AB - Studies on lymphoid organ spheroid (LOS) cells of Penaeus monodon were
undertaken. Phenoloxidase and peroxidase assays showed that LOS cells have
characteristics similar to semi-granular and, in particular, large granular
haemocytes. The mean percentage of LOS cells positive for phenoloxidase and
peroxidase was 85 +/- 23 and 82 +/- 23%, respectively. There was no significant
difference between the sites of phenoloxidase and peroxidase activity in LOS
cells (t = 1.617, df = 29, p > 0.05). The relative sectional area occupied by LOS
cells relative to that of the stromal matrix cells from both laboratory-held and
farmed prawns was not correlated to increasing weight or total length of the
prawns (p > 0.05). An apoptosis detection assay showed that LOS cells were often
apoptotic whilst stromal matrix cells were not. There was a significant
difference (t = -5.533, df = 58, p < 0.05) in the mean percentage of apoptotic
spheroid cells between laboratory-held prawns (52 +/- 24%) and farmed prawns with
midcrop mortality syndrome (MCMS) (80 +/- 12%). In conclusion, LOS cells have the
characteristics of exocytosed, granular haemocytes that have phagocytosed foreign
material, particularly viruses, and probably constitute a major mechanism for
penaeid antiviral defense.
PMID- 10782342
TI - Diagnosis of Penaeus monodon-type baculovirus by PCR and by ELISA of occlusion
bodies.
AB - The black tiger prawn Penaeus monodon is a valuable aquaculture product in
Taiwan. Two specific diagnostic methods were established for P. monodon-type
baculovirus, one using polymerase chain reaction (PCR) technology and the other
enzyme-linked immunosorbent assay (ELISA) technology. Monodon-type baculovirus
(MBV) was purified by sucrose gradient centrifugation from occlusion bodies of
MBV-infected postlarvae of P. monodon. MBV DNA was subsequently purified from the
occlusion bodies and its presence was confirmed by PCR using primers of the
polyhedrin gene. Based on conserved sequences of the DNA polymerase genes of
Autographa californica nuclear polyhedrosis virus (AcMNPV) and Lymantria dispar
nuclear polyhedrosis virus (LdMNPV), primers were designed and synthesized to
yield a 714 bp PCR fragment from MBV. However, the sequence of this fragment
revealed low homology with that of LdMNPV and AcMNPV. From the DNA sequence of
this fragment, a second set of primers was designed, and using these primers, a
511 bp DNA fragment was amplified only when MBV DNA was the template. DNA
templates from AcMNPV, white spot syndrome diseased shrimp, or PMO cells (a cell
line derived from the Oka organ of Penaeus monodon) did not give any amplified
DNA fragment. Therefore, this primer pair was specific for the diagnosis of MBV.
By using intraspleenic immunization of rabbits with purified MBV occlusion
bodies, a polyclonal rabbit antiserum against MBV was obtained. This antiserum
could detect nanogram levels of MBV, but did not cross react with white spot
syndrome virus (WSSV), homogenates of PMO cells, postlarvae, hepatopancreatic
tissue or intestinal tissue of black tiger prawns by competitive ELISA. This
sensitive method could detect MBV even in tissue homogenates.
PMID- 10782343
TI - Toxic factors of Vibrio strains pathogenic to shrimp.
AB - Vibriosis is a major disease problem in shrimp aquaculture. 'Syndrome 93' is a
seasonal juvenile vibriosis caused by Vibrio penaeicida which affects Litopenaeus
stylirostris in grow-out ponds in New Caledonia. This study assessed the toxic
activities of extracellular products (ECPs) from V. penaeicida, V. alginolyticus
and V. nigripulchritudo using in vivo injections in healthy juvenile L.
stylirostris (= Penaeus stylirostris) and in vitro assays on shrimp primary cell
cultures and the fish cell line epithelioma papulosum cyprini (EPC). Toxic
effects of ECPs were demonstrated for all pathogenic Vibrio strains tested both
in vivo and in vitro, but for shrimp only; no effect was observed on the fish
cell line. ECP toxicity for New Caledonian V. penaeicida was found only after
cultivation at low temperature (20 degrees C) and not at higher temperature (30
degrees C). This points to the fact that 'Syndrome 93' episodes are triggered by
temperature drops. The assays used here demonstrate the usefulness of primary
shrimp cell cultures to study virulence mechanisms of shrimp pathogenic bacteria.
PMID- 10782344
TI - Rapid and sensitive PCR detection of Vibrio penaeicida, the putative etiological
agent of syndrome 93 in New Caledonia.
AB - Experimental infections of Penaeus (Litopenaeus) stylirostris were performed with
a Vibrio penaeicida strain (AM101) isolated in New Caledonia from Syndrome 93
diseased shrimp. Cumulative mortalities resulting from intramuscular injection or
immersion of shrimp in bacterial suspensions demonstrated high virulence for this
bacterial strain and suggested that V. penaeicida could be the etiological agent
of Syndrome 93. The median lethal dose (LD50) for AM101 was 1.3 x 10(4) CFU
(colony forming units) ml-1 by immersion and less than 5 CFU shrimp-1 by
intramuscular challenge, with mortality outbreaks at 48 and 22 h after challenge,
respectively. A polymerase chain reaction (PCR) detection assay using a primer
set designed from the 16S ribosomal RNA gene of V. penaeicida was developed. It
gave an expected amplicon of approximately 310 bp in ethidium bromide-stained
agarose gels. The specificity of these primers was assessed with different Vibrio
species. Furthermore, DNA extracted by the Chelex method could be used to detect
fewer than 20 cultured Vibrio cells in sea-water or shrimp hemolymph by this
assay. It appears to be a reliable screening method for detecting V. penaeicida
in shrimp and from the aquatic environment.
PMID- 10782345
TI - Antigenic characterization of Sphaerospora dicentrarchi (Myxosporea:
Bivalvulida), a parasite from European sea bass Dicentrarchus labrax (Teleostei:
Serranidae).
AB - The biochemical composition of Sphaerospora dicentrarchi was studied. Periodate
and Proteinase K treatments as well as lectin blots were used to analyse
carbohydrate terminals. Zymography was applied to detect proteases. Four
polyclonal antisera, raised against S. dicentrarchi (RaSdic), S. testicularis
(RaStest), Ceratomyxa labracis (RaClab) and C. sparusaurati (RaCspr), were used
in SDS polyacrylamide gel electrophoresis and immunoblot. Bands with molecular
weight (MW) between 32 and 130 kDa were detected by electrophoresis. After
Proteinase K treatment, apparent digestion of bands heavier than 43 kDa took
place. RaSdic and RaStest detected similar bands with MW between 20 and 50 kDa,
whereas RaClab and RaCspr recognized bands between 50 and 140 kDa. The 50 kDa
band was recognized by all the polyclonal antisera, suggesting that it could
correspond to an antigen shared by several myxosporean parasites. Four proteases
were observed by zymography. From the 5 lectins assayed, binding was only
observed using Con-A, which detected 2 bands of 96 and 78 kDa. Periodate
treatment did not produce any effect on the binding of RaSdic and RaStest, but a
high decrease of intensity in the antibody binding occurred at a concentration of
10 and 20 mM periodate when RaClab and RaCspr were tested. These results give
information on the antigenic composition of S. dicentrarchi which could be useful
for further diagnostic or immunoprevention studies.
PMID- 10782346
TI - Ribosomal DNA sequences of Glugea anomala, G. stephani, G. americanus and
Spraguea lophii (Microsporidia): phylogenetic reconstruction.
AB - The microsporidian species Glugea anomala, G. stephani, G. americanus and
Spraguea lophii were compared by using sequence data derived from their small
subunit rDNA genes which were amplified by polymerase chain reaction and directly
sequenced. These sequence data and published data of G. atherinae were analyzed
and were used to infer a phylogenetic tree. The 5 microsporidian fish parasites
appeared to be closely related. The higher sequence similarities demonstrated
among G. anomala, G. stephani and G. atherinae suggest that these 3 parasites are
in fact only 1 species of Glugea. Moreover, the higher sequence similarities
between S. lophii and G. americanus support the transfer of the latter Glugea
species into the genus Spraguea.
PMID- 10782347
TI - Experimental and natural host specificity of Loma salmonae (Microsporidia).
AB - The microsporidian Loma salmonae (Putz, Hoffman & Dunbar, 1965) Morrison &
Sprague, 1981 has caused significant gill disease in Pacific salmon Oncorhynchus
spp. Host specificity of the parasite was examined experimentally by per os
challenge of selected salmonids and non-salmonids with infective chinook salmon
O. tshawytscha gill material. Pink Oncorhynchus gorbuscha and chum salmon O.
keta, brown Salmo trutta and brook trout Salvelinus fontinalis, and chinook
salmon (controls) were positive, whereas Atlantic salmon Salmo salar and Arctic
char Salvelinus alpinus were negative. In addition, no non-salmonids were
susceptible to experimental exposure. Wild Pacific salmon species in British
Columbia, Canada, were examined for L. salmonae during their freshwater life
history stages (smolts, prespawning, spawning). All stages were infected,
although infections in smolts were only detectable using a L. salmonae-specific
PCR test. Many previous Loma spp. described from Oncorhychus spp. are likely L.
salmonae based on host, parasite morphology, and site of infection.
PMID- 10782348
TI - Molecular detection of Marteilia sydneyi, pathogen of Sydney rock oysters.
AB - The life cycle of Marteilia sydneyi, the aetiological agent of QX disease in the
Sydney rock oyster Saccostrea commercialis, is not known. We have developed and
optimised 2 diagnostic assays, the polymerase chain reaction (PCR) and in situ
hybridisation, for use in investigating the role of possible alternative hosts in
the life cycle of this pathogen. PCR primers, designed within the ITS1 rDNA of M.
sydneyi, amplified a 195 bp fragment. Sensitivity of the PCR assay was assessed
using DNA extracted from known numbers of sporonts purified from infected oyster
digestive gland. DNA equivalent to 0.01 sporonts was detectable following agarose
gel electrophoresis. The potential inhibitory effect of the presence of host DNA
on the PCR assay was tested by the addition of oyster genomic DNA during
amplification. Concentrations of host DNA in excess of 50 ng per 20 microliters
reaction reduced the sensitivity of the test. Environmental validation of the PCR
assay was demonstrated by the amplification of M. sydneyi DNA from 50 ng of
genomic DNA extracted from QX-infected oysters. A DNA probe was constructed using
the M. sydneyi unique primers and was able to detect 10 pg of M. sydneyi PCR
amplified DNA in dot-blot hybridisations. The probe hybridised with
presporulating and sporulating M. sydneyi stages in paraffin sections of oyster
digestive gland. No non-specific binding was observed. Hybridisation consistency
and signal intensity decreased as sporonts matured. While the high sensitivity
and specificity of the PCR test will allow rapid screening of large numbers of
potential alternative hosts for the presence of parasite DNA, it does not
actually identify infective stages. In situ hybridisation conducted on paraffin
sections will determine the location of the parasite within the host for
morphological characterisation.
PMID- 10782349
TI - Lympholeukemia in madai Pagrus major in Japan.
AB - Lympholeukemia has been occurring to an epizootic extent with mass mortality in 1
and 2 yr old madai (= Japanese red sea bream) Pagrus major in the winter season
(October-May) in the western regions of Japan since 1975. Diseased fish displayed
severe anemia and markedly increased numbers of neoplastic lymphocytoid and
lymphoblastoid cells in the blood. Neoplastic cells originated in the splenic
lymphatic cells and systemically caused severe metastatic lesions in the heart,
liver, kidney, digestive tracts, gills and the lateral musculature. Electron
microscopy revealed adeno-like viral particles (78 to 83 nm in diameter) in the
nucleus of lymphoblastoid cells which appeared in the early prevalent stage but
no viral particles in the lymphocytoid cells or plasmacytoid cells, which
subsequently increased in number. In this paper, we describe light and electron
microscopic features of neoplasms and neoplastic cells.
PMID- 10782350
TI - Natural and experimental infection of white spot syndrome virus (WSSV) in benthic
larvae of mud crab Scylla serrata.
AB - White spot syndrome virus (WSSV), the causative agent of white spot syndrome in
shrimp, has a wide host range which extends to crabs, copepods and other
arthropods. In this study, benthic larvae of the mud crab Scylla serrata were
captured from Taiwan's coastal waters and screened for the presence of WSSV by
polymerase chain reaction (PCR) and in situ hybridization. WSSV was detected in
around 60% of the larvae, and this prevalence rate remained fairly constant when
the captured larvae were subsequently maintained in an aerated system in the
laboratory. WSSV-free larvae obtained from a hatchery were challenged by
immersion in a WSSV inoculum. Fifteen days after challenge, cumulative mortality
in the experimental group reached 43% compared to 20% in the control group. PCR
detection of WSSV in both moribund and surviving specimens clearly implicated the
virus as the cause of death in most cases. Histological and in situ hybridization
data confirmed that WSSV tissue tropism in Scylla serrata crab larvae is similar
to that found in shrimp.
PMID- 10782351
TI - The use of fractional parameter in analyzing motor unit discharge pattern in
stroke patients: a correlation with the functional independence measurement.
AB - BACKGROUND: We have previously demonstrated that the fractional parameter has
significant correlation with the muscle strength of patients with stroke. In this
study, we have investigated whether fractional parameter can be used to
objectively document stroke patients' functional level (using FIM scores).
METHODS: Sixty motor units were recorded in abductor pollicis brevis, first
dorsal interosseous, and abductor digiti minimi muscles in 18 stroke patients.
Patients' FIM scores, obtained fractional parameters, and serial correlation
coefficients were analyzed and statistical determination was made. RESULTS:
Statistical significance was found between fractional parameters and motor items
of FIMs (except selfcare category); no statistical significant correlation was
found between SSC and FIM scores. CONCLUSION: Fractional parameter could be a
useful tool for measuring motor function at a single motor unit level.
PMID- 10782352
TI - Hyperexcitability of cervical motor neurons during neck flexion in patients with
Hirayama disease.
AB - We recorded the motor evoked potentials (MEPs) from the affected thenar muscles
during neck flexion in 4 patients in the early progressive phase of Hirayama
disease. The MEP size significantly increased during neck flexion in patients
compared with normal controls. In 2 patients who were treated with a neck collar,
the intrinsic muscle atrophy gradually recovered together with increased grip
power, and the time course of changes in MEP during neck flexion became normal
after treatment with a neck collar for 7-16 months. The technique described here
would be useful for evaluating the vulnerability of cervical motor neurons and
the therapeutic effect of the neck collar in Hirayama disease.
PMID- 10782353
TI - The diagnostic value of stapedius reflex and stapedius reflex exhaustion in
myasthenia gravis.
AB - Authors studies impedance, stapedius reflex thresholds and stapedius muscle
exhaustion on 31 ears of 16 MG patients. Investigations were carried out using
GSI 33 computer-assisted middle ear analyzator. Stapedius reflex threshold values
were increased in 93% of patients. Stapedius exhaustion was observed in 71% of
patients. After the administration of the reversible cholinesterase inhibitor
Mestinon (60 mg pyridostigmin bromide), reflex threshold decreased and exhaustion
occurred in only 50% of cases. Authors review the literature in context with the
audiometric diagnostics of MG and also recommend the use of these methods in more
complicated ocular and bulbar cases of MG.
PMID- 10782354
TI - Proximal receptors and the mechanical stimulation of the fingers: a somatosensory
evoked potential study.
AB - OBJECTIVE: To characterize scalp responses to mechanical stimulation of the
fingers and evaluate the contribution of different receptors. DESIGN AND METHODS:
Somatosensory evoked responses to mechanical stimulation of the right third
finger were recorded from a P3-P4 montage (n = 15) and from a F3-P4 montage (n =
9) as well as after electrical stimulation (n = 9). Responses after mechanical
stimulation of the distal region of the finger, with the hand at different
positions, were also recorded (n = 8). Complementary experiments in a small
number of individuals included EMG and accelerometer recordings as well as
anaesthesia of the finger. RESULTS: Scalp responses characterized by an initial
sequence of waves, here called NI-PI-NII, were recorded from the P3-P4 montage.
Mean peak latencies were 20, 23 and 26 ms, respectively; electrical stimulation
of the same region evoked an initial negativity (mean peak latency 23 ms). EMG
recordings suggested the involvement of different receptors in response to
electrical and mechanical stimulation. Accelerometer recordings showed the spread
of a sizable mechanical wave at the forearm. Anaesthesia did not change the
responses to mechanical stimulation. CONCLUSIONS: Relatively small mechanical
stimuli applied at distal phalanxes may activate proximal receptors which
generate scalp recorded responses that may completely occlude the contribution of
the distal receptors.
PMID- 10782355
TI - Silent period in carpal tunnel syndrome.
AB - The silent period is a misunderstood electrophysiological phenomenon leading to
several different hypotheses explaining its electrogenesis. It has been studied
by different authors and different methodologies giving a wide variability of
results, therefore an exact pattern of its normal values does not exist. This
work was undertaken to define the normal morphology and duration of the silent
period obtained by supramaximal stimulus of the median nerve, during maximum
isometric effort of the abductor pollicis brevis muscle against resistance, using
20 adult volunteers without neurological alterations. The normal median duration
was 104.6 milliseconds. The same methodology was applied to 20 hands from 20
patients with carpal tunnel syndrome. The silent period showed many types of
morphological alterations, but the major alteration observed was a tendency to
temporal elongation. No correlation between the severity of the carpal tunnel
syndrome and the silent period alterations were observed.
PMID- 10782356
TI - The sensitivity of sympathetic skin responses and standard electrophysiological
methods in diagnosis of diabetic neuropathy.
AB - This study was planned to compare the sensitivity of standard electrophysiologic
methods and sympathetic skin responses (SSRs) in the diagnosis of diabetic
neuropathy. Randomly selected 49 patients, who were followed by Haydarpasa Numune
Hospital Diabetes Outpatient Department and age matched 26 healthy persons were
included in the study. All of the patients and control subjects were assessed by
standard electrophysiologic methods (nerve conduction velocities, H-reflex, F
waves) and SSRs parameters. The abnormality ratios were 85.8% for standard
electrophysiological methods, and 76.2% for SSRs. The higher abnormality ratio
for SSRs was found important. As a result, it was concluded that standard
electrophysiologic methods (including F-wave latency) and SSRs investigations for
the early diagnosis of diabetic neuropathy, could be very useful in the
prevention of morbidity.
PMID- 10782357
TI - The F response parameters in Behcet's disease.
AB - The F response parameters may provide a sensitive method for detection of mild
neuropathy in patients with otherwise normal nerve conduction studies. We
investigated conventional nerve conduction studies and F response parameters in
patients with Behcet's disease (BD), but without neurologic involvement. The
results indicate that ulnar motor and sensory, tibial motor and sural sensory
nerve conduction studies failed to differentiate the patients with BD and
controls. In the ulnar nerve, the F response parameters were not significantly
different for the populations. In the tibial nerve, the F response latency and
chronodispersion were increased while F amplitude, duration, and persistence were
all decreased in patients with BD. The results suggests that, (1) peripheral
nerve dysfunction occurred especially in lower extremities in patients with
Behcet's disease. (2) The F response parameters were considered the most
sensitive method for the detection of neuropathy in Behcet's disease.
PMID- 10782358
TI - The effects of leg angular velocity on mean power frequency and amplitude of the
mechanomyographic signal.
AB - The purpose of the present investigation was to examine the effects of leg
angular velocity on the mean power frequency (MPF) and amplitude of the
mechanomyographic (MMG) signal during maximal concentric (CON) isokinetic muscle
actions. Sixteen adult subjects performed maximal CON leg extensions on a
calibrated Cybex 6000 dynamometer at leg angular velocities of 60 and 300
degrees.s-1. MMG was detected by a piezoelectric crystal contact sensor placed
over the mid-portion of the vastus lateralis muscle. The results indicated a
significant (p < 0.05) velocity-related decrease in peak torque (PT) and increase
in MMG amplitude from 60 to 300 degrees.s-1. There was, however, no velocity
related change (p > 0.05) in MMG MPF. These findings did not support our
hypothesis that increases across velocity in MMG amplitude were due to decreases
in muscle stiffness as a result of a shift in the contribution of slow and fast
twitch muscle fibers to PT production. Future research should examine the
potential influence of actin-myosin cycling rate as well as limb movement on the
MPF and amplitude of the MMG signal.
PMID- 10782359
TI - Tethered median nerve stress test in the diagnosis of carpal tunnel syndrome.
AB - The sensitivity of the Median Nerve Stress Test (Stress Test) described by La Ban
et al. and performed hyperextending for one minute the supinated wrist and the
distal interphalangeal joint of the index finger and looking for pain in the
proximal forearm was evaluated in 140 arms with Carpal Tunnel Syndrome confirmed
electrophysiologically. The Stress Test was positive in 60 hands (42.8%), the
Phalen's sign in 79 (56.4%) and the Tinel's sign in 59 (42.1%). Hypoaesthesia to
pinprick in the distribution of the median nerve was found in 45 hands (32.1%)
and weakness or hypotrophia of thenar eminence in 17 (12.1%). In spite of his low
sensitivity, in some cases the Stress Test was the only clinical positive sign
and, in addition to electrophysiological examination, may be helpful in clinical
practice.
PMID- 10782360
TI - Sensory potential can be preserved in severe common peroneal neuropathy.
AB - Neuropathy of Common Peroneal Nerve (CPN) is a frequent clinical condition,
generally caused by compression at the fibula head. Three neurophysiological
patterns were described: 1) segmental demyelination with conduction block; 2)
axonal damage with loss of motor units and sensory potential; 3) a mixed pattern.
We report 5 patients with foot drop in whom CPN neuropathy was identified. In 3
in spite of impressive abnormalities in various motor branches and fascicles of
the nerve, the peroneus nerve sensory potential remained well preserved. Focal
neuropathies can be remarkably selective in terms of motor and sensory deficits,
the reason can rely on a different location of the fibres or be related to a
distinct histological-biochemical constitution. A preserved SPSP should not
exclude a CPN neuropathy.
PMID- 10782361
TI - Birth and death of bone cells: basic regulatory mechanisms and implications for
the pathogenesis and treatment of osteoporosis.
AB - The adult skeleton regenerates by temporary cellular structures that comprise
teams of juxtaposed osteoclasts and osteoblasts and replace periodically old bone
with new. A considerable body of evidence accumulated during the last decade has
shown that the rate of genesis of these two highly specialized cell types, as
well as the prevalence of their apoptosis, is essential for the maintenance of
bone homeostasis; and that common metabolic bone disorders such as osteoporosis
result largely from a derangement in the birth or death of these cells. The
purpose of this article is 3-fold: 1) to review the role and the molecular
mechanism of action of regulatory molecules, such as cytokines and hormones, in
osteoclast and osteoblast birth and apoptosis; 2) to review the evidence for the
contribution of changes in bone cell birth or death to the pathogenesis of the
most common forms of osteoporosis; and 3) to highlight the implications of bone
cell birth and death for a better understanding of the mechanism of action and
efficacy of present and future pharmacotherapeutic agents for osteoporosis.
PMID- 10782362
TI - Adrenomedullin, a multifunctional regulatory peptide.
AB - Since the discovery of adrenomedullin in 1993 several hundred papers have been
published regarding the regulation of its secretion and the multiplicity of its
actions. It has been shown to be an almost ubiquitous peptide, with the number of
tissues and cell types synthesizing adrenomedullin far exceeding those that do
not. In Section II of this paper we give a comprehensive review both of tissues
and cell lines secreting adrenomedullin and of the mechanisms regulating gene
expression. The data on circulating adrenomedullin, obtained with the various
assays available, are also reviewed, and the disease states in which plasma
adrenomedullin is elevated are listed. In Section III the pharmacology and
biochemistry of adrenomedullin binding sites, both specific sites and calcitonin
gene-related peptide (CGRP) receptors, are discussed. In particular, the putative
adrenomedullin receptor clones and signal transduction pathways are described. In
Section IV the various actions of adrenomedullin are discussed: its actions on
cellular growth, the cardiovascular system, the central nervous system, and the
endocrine system are all considered. Finally, in Section V, we consider some
unresolved issues and propose future areas for research.
PMID- 10782363
TI - Management of Graves' ophthalmopathy: reality and perspectives.
AB - Graves' ophthalmopathy is an debilitating disease impairing the quality of life
of affected individuals. Despite recent progress in the understanding of its
pathogenesis, treatment is often not satisfactory. In mild cases, local
therapeutic measures (artificial tears and ointments, sunglasses, nocturnal
taping of the eyes, prisms) can control symptoms and signs. In severe forms of
the disease (3-5%), aggressive measures are required. If the disease is active,
high-dose glucocorticoids and/or orbital radiotherapy, or orbital decompression
represent the mainstay of treatment. If the disease is severe but inactive,
orbital decompression is preferred. Novel treatments such as somatostatin analogs
or intravenous immunoglobulins are under evaluation. Rehabilitative (extraocular
muscle or eyelid) surgery is often needed after treatment and inactivation of eye
disease. Correction of both hyper- and hypothyroidism is crucial for the
ophthalmopathy. Antithyroid drugs and thyroidectomy do not influence the course
of the ophthalmopathy, whereas radioiodine treatment may cause the progression of
preexisting ophthalmopathy, especially in smokers. The exacerbation, however, is
prevented by glucocorticoids. In addition, thyroid ablation may prove beneficial
for the ophthalmopathy in view of the pathogenetic model relating eye disease to
autoimmune reactions directed against antigens shared by the thyroid and the
orbit.
PMID- 10782364
TI - Initial and cyclic recruitment of ovarian follicles.
AB - Mammalian ovaries consist of follicles as basic functional units. The total
number of ovarian follicles is determined early in life, and the depletion of
this pool leads to reproductive senescence. Each follicle develops to either
ovulate or, more likely, to undergo degeneration. The dynamics of ovarian
follicle development have interested endocrinologists and developmental
biologists for many years. With the advent of assisted reproductive techniques in
humans, the possibility of regulating follicle development in vivo and in vitro
has gained clinical relevance. In this review, we focus upon key branching points
during the development of ovarian follicles as well as factors involved in
determining the eventual destiny of individual follicles. We discuss
inconsistencies in the literature regarding the definitions of follicle
recruitment and selection and propose to name the two major steps of follicle
development as initial and cyclic recruitment, respectively. Because some of
these disparities have arisen due to differences in the animal systems studied,
we also compare the development of the ovarian follicles of both humans and rats.
We also review the status of knowledge of several puzzling clinical issues that
may provide important clues toward unlocking the mechanisms of follicle
development.
PMID- 10782365
TI - End-of-life care seen from broader perspective.
PMID- 10782366
TI - Sharing the mystery of death with new acquaintances.
PMID- 10782367
TI - Preventing the difficult learning situation.
PMID- 10782368
TI - Teacher comfort in teaching sexuality: reflections from an STFM seminar.
PMID- 10782369
TI - Challenges to academic family medicine in the current health care environment.
AB - BACKGROUND: Changes in health care delivery and funding have placed strains on
academic medical centers' ability to meet their multiple missions. To gain
insight into how this new academic landscape is affecting academic primary care,
this study examined the current status and perceived challenges at nine
departments of family medicine at allopathic and osteopathic medical schools.
METHODS: Site visits were made to nine academic departments of family medicine
where key informant interviews were conducted with several individuals in key
leadership positions. Sites were chosen to maximize diversity among departments
along a variety of factors, such as location, size, mission, and type of school
(private versus public). Interviews were transcribed and analyzed by a three
person multidisciplinary team for key themes. RESULTS: Analysis of interviews
revealed five major challenges for academic departments of family medicine: 1)
adjusting to new clinical demands in the academic health center, 2) organizing
and administering new initiatives in community-based education, 3) recruiting and
retaining faculty, 4) developing and maintaining research capacity, and 5)
serving multiple missions (education, clinical care, and academic pursuits) in
times of financial restraint. CONCLUSIONS: Significant challenges face academic
departments of family medicine. The success or failure of departments of family
medicine to meet these challenges could serve as a bellwether for how primary
care fits into the future overall scheme of academic health centers.
PMID- 10782370
TI - Long-term effects of a primary health care intervention program for women: lower
blood pressure and stable weight.
AB - BACKGROUND: In Stromstad, with 10,000 inhabitants, a cardiovascular prevention
program was launched during 1985-1987 because of high rates of cardiovascular
disease. To study long-term effects in women, an 8-year follow-up was conducted.
METHODS: Participants (n = 114) and nonparticipants (n = 269) in the lifestyle
intervention program in 1985-1987 (both groups with cardiovascular risk factors)
were compared regarding risk factor levels after 8 years. Effects were also
compared to another community not exposed to intervention. RESULTS: After 8
years, intervention participants showed significant reduction of mean systolic
blood pressure compared to the control group and had higher intake of dietary
fibers and more-positive attitudes to and better knowledge of healthy diets.
There was no increase of mean body weight or serum triglyceride levels whatsoever
in the intervention group. Compared with another female population not exposed to
intervention, body weight and systolic blood pressure changed in a significantly
more favorable way. CONCLUSIONS: Results from the prevention program could be
discerned after 8 years. Advantages in risk factor changes could also be found
when comparing with another female population. Given the high level of stroke in
women within the community, the blood pressure advantage in the intervention
group is particularly encouraging.
PMID- 10782372
TI - Recruitment behavior and program directors: how ethical are their perspectives
about the match process?
AB - OBJECTIVE: This study examined family practice residency directors' perspectives
on the 1999 National Resident Matching Program (NRMP) process and identified
directors' expectations for students' recruitment behavior. METHODS: Subjects
were the family practice residency program directors. A 22-item written
questionnaire was mailed to each director. The questions related to the
directors' perceptions of the following issues: applicants interviewing in more
than one specialty, communication initiated by programs or applicants,
commitments made to applicants and by applicants, ethical dilemmas faced by the
program director, and the NRMP process itself. Descriptive statistics were
reported. RESULTS: Only a few of the residency program directors (9.1%) felt that
it was ethically wrong for an applicant to interview in more than one specialty.
However, most program directors (83%) indicated that the knowledge of an
applicant interviewing in more than one specialty had a "significant" negative or
"some" negative effect on the applicant's rank order. Ninety-five percent of
program directors indicated that they engage in follow-up communication with
applicants following the formal interview. Almost all program directors (98%)
reported that at least some applicants contact them following the formal
interview to inform them that the program was a "high" or No. 1 rank-order
choice. The majority of program directors (94%) felt that the NRMP process placed
their program in the position of having to be dishonest with applicants to match
their top choices. CONCLUSIONS: The results of the study indicate that the
actions of many program directors and applicants may not be consistent with the
written policies of the NRMP.
PMID- 10782371
TI - Prevalence of the use of herbal products in a low-income population.
AB - OBJECTIVES: This study determined the prevalence of herb/supplement use in a low
income population and determined the providers' level of knowledge about
herbs/supplements. METHODS: Adult English-speaking patients seen at a rural
family practice residency clinic were offered an anonymous survey. Another survey
was developed for the clinic providers. Data were analyzed using the chi-square
test. RESULTS: Fifty-six percent of a low-income population use
herbs/supplements; 41% of all users cited friends or relatives as their main
source of information, and 53% of users had not informed their provider. In the
provider survey, 69% of the providers indicated that they had received no
education about herbs/supplements, yet 71% were asked about them by patients at
least twice a month. CONCLUSIONS: Because herb/supplement use occurs across all
demographic groups, all patients should be questioned about their use of such
substances. Currently, few providers are prepared to guide their patients about
herbs/supplements. Efforts should be made to educate health care providers about
common herbs/supplements.
PMID- 10782373
TI - A comparison of resident and faculty attitudes toward physician-assisted suicide
and active voluntary euthanasia.
AB - PURPOSE: Assisted death practices such as physician-assisted suicide (PAS) and
active voluntary euthanasia (AVE) are becoming more acceptable to the public and
the medical profession. This study compared the attitudes and practices of
resident house staff physicians with the medical staff physicians responsible for
teaching them regarding PAS and AVE. METHODS: A convenience sample of 372 medical
staff and 105 resident house staff from a multi-residency community teaching
hospital were anonymously surveyed. The overall response rate was 47%. The
questionnaire consisted of 10 questions that examined the subjects' professional
and legal values, willingness to participate in assisted death practices, and
personal preferences for assisted death practices. RESULTS: The resident house
staff differed significantly from the medical staff in attitudes toward assisted
death practices. The resident house staff was less likely to support the
traditional prohibitions against PAS and AVE. The resident house staff was also
more likely to offer assisted death practices if they were legal. There was no
significant difference, however, in the participation of assisted death practices
between the groups respectively for PAS and AVE. The residents were more likely
to request PAS or AVE for themselves or family members. CONCLUSIONS: There are
significant differences in attitudes and practices between resident physicians
and medical staff physicians concerning PAS and AVE. These differences could lead
to professional conflicts when setting clinical goals for end-of-life care and
could compromise patient care.
PMID- 10782374
TI - Applied medical informatics and computing skills of students, residents, and
faculty.
AB - BACKGROUND AND OBJECTIVES: Little is known regarding the applied medical
informatics and computing skills of family practice residents and faculty, yet
such information is critical when planning a medical informatics curriculum. We
conducted a survey at our institution to collect this information. METHODS: An
applied medical informatics and computing skills survey was administered to 93
first-year medical students, 42 family practice residents, and 14 family medicine
faculty. Responses were compared between groups before and after stratification
by age and gender. RESULTS: A total of 92% of students, 100% of residents, and
79% of faculty responded. Faculty had the highest rate of computer ownership
(91%), followed by students (86%) and family practice residents (79%). Students
and interns had the highest overall confidence using computers, followed by
faculty and then senior residents. Faculty, students, and junior residents were
significantly more confident than senior residents in their ability to perform
several specific tasks, such as conducting a MEDLINE search. Residents perceived
lack of money and time as barriers to improving their skills. CONCLUSIONS:
Current senior residents may require remedial training to graduate with the
computer skills specified in curricular guidelines. While upcoming medical
students and interns will demand more advanced training, faculty may not have the
skills to provide it.
PMID- 10782375
TI - Core curriculum guidelines: minimum standards, practical goals, or lofty ideals?
PMID- 10782376
TI - Quinoxaline chemistry. Part 13: 3-Carboxy-2-benzylamino-substituted quinoxalines
and N-[4-[(3-carboxyquinoxalin-2-yl) aminomethyl]benzoyl]-L-glutamates: synthesis
and evaluation of in vitro anticancer activity.
AB - Among a new series of 28 3-carboxy or carbethoxy quinoxalines bearing a
substituted benzylamino or N-[4-(aminomethyl)benzoyl]glutamate group on position
2 of the ring and various substituents at C-6, 7 positions, 21 were selected at
the National Cancer Institute for evaluation of their in vitro anticancer
activity. The results obtained seem to confirm that the carboxy or carbethoxy
group on position 3 is not helpful, with a few exceptions, for the anticancer
activity.
PMID- 10782377
TI - Quantitation of pharmaceutically important phenothiazines by oxidimetry.
AB - A new spectrophotometric method for the assay of phenothiazines in pure form as
well as in pharmaceutical formulations with the chromium(VI)-metol-sulfanilic
acid system has been developed. The method is based on the oxidation of the drugs
by a known excess of chromium(VI) and subsequent determination of the unreacted
oxidant by interacting with metol and sulfanilic acid. The reacted oxidant
corresponds to the drug content. The coloured species exhibits maximum absorbance
at 530 nm. Beer's law is obeyed over the concentration range 5-60 micrograms ml-1
and the relative standard deviation is found to be less than 2%. The apparent
molar absorptivities are in the range 3.77 x 10(3)-3.98 x 10(3) l mol-1 cm-1, the
detection limits being in the range 0.6133-1.1349 micrograms ml-1. The method was
successfully applied to the determination of the studied drugs in their
formulations and the mean percentage recoveries were found to be 97.32-102.80%.
PMID- 10782378
TI - Synthesis and antimicrobial activity of novel arylideneisothiosemicarbazones.
AB - Arylidenimidazoles bearing a thioethereal function in the position 2 of the
imidazole ring show good antimicrobial activity. We now report on the synthesis
and the biological properties of some novel arylidenisothiosemicarbazones,
structurally related to the arylideneiminoimidazoles of which they can be
considered the linear precursors. Particular attention has been put on the
influence of structural modifications on the biological activity.
PMID- 10782379
TI - Potentiometric determination of nitrate in products used for the treatment of
dentinal hypersensitivity.
AB - In this paper, a rapid, simple and inexpensive potentiometric method for the
determination of the potassium nitrate contained in different dentinal
desensitizer products is described. The nitrate-selective electrode, using a
tetraoctylammonium salt as sensor, was constructed without an internal filling
solution. The ionic strength of the sample solutions was fixed by means of a 0.33
mol 1(-1) K2SO4 solution and direct potentiometry was used as the analytical
technique of measurement. Precision and accuracy of the method developed were
adequate since the mean of the relative standard deviations was 1.2% and the
average percentage of spike recoveries was 100.9%. Eleven samples of toothpastes,
gels and mouthwashes were analyzed by the proposed potentiometric method and the
quality of the results was compared by means of linear regression analysis with
those obtained by high-performance liquid chromatography (HPLC), adopted as the
reference technique. Satisfactory agreement was observed.
PMID- 10782381
TI - Synthesis of some new thiazolo[3,2-a]pyridines and related heterocyclic systems.
AB - New 2,7-disubstituted 5-amino-6,8-dicyano-2,3-dihydro-3-oxo thiazolo[3,2
a]pyridines have been prepared. Their cyclization with formamide, nitrous acid
and triethylorthoformate afforded a series of polycyclic heterocycles containing
condensed pyrimidine and triazine rings. Antifungal tests were also performed.
PMID- 10782380
TI - Synthesis and antiviral properties of 9-[(2-methyleneaminoxyethoxy)methyl]guanine
derivatives as novel Acyclovir analogues.
AB - This paper reports the synthesis and the antiviral properties of a series of 9
[(2-methyleneaminoxyethoxy)methyl]guanine derivatives, which can be viewed as
analogues of the antiherpes drug Acyclovir (ACV) from which they differ in the
replacement of its hydroxy group with variously substituted methyleneaminoxy
moieties. Some of the newly synthesized compounds proved to possess a certain
activity against HSV-1, albeit lower than that of ACV.
PMID- 10782382
TI - Disoxaril-related 3-(diethylamino)-5-phenylisoxazoles.
AB - Previous research has shown that 3-(dialkylamino)-5-phenylisoxazoles possessing a
compact structure were active against HRV-2 and, consequently, presented a type B
activity. In this paper, 3-(diethylamino)-5-phenylisoxazoles, which are
structurally more elongated and related to Disoxaril, were synthesized in view to
attempt type A activity against HRV-14. Unfortunately, all tested compounds were
devoid of activity against HRV-14 (and HIV-1) or exhibited great toxicity.
PMID- 10782384
TI - UV derivative spectrophotometric study of the photochemical degradation of
nisoldipine.
AB - The photodecomposition of nisoldipine ((+/-)3-isobutyl-5-methyl-1,4- dihydro-2,6
dimethyl-4-(2-nitrophenyl)-pyridine-3,5-dicarboxylate), whereby its 4-(2
nitrosophenyl) pyridine analogue is obtained as the photolytic product, was
investigated under daylight exposure by means of UV derivative spectrophotometry.
The optimal instrumental parameters (120 nm/min scan speed; 2 nm slit width;
delta gamma = 10 nm and 5 s response time) for analogue derivative spectra were
established for amplitudes 1D285 and 2D291 (measured to the baseline) of the
nitroso analogue assay, as well as for 1D386 of the parent compound-nisoldipine
assay. Using the first-order derivative spectrum, the minimum detectable amount
of nitroso analogue in the presence of nisoldipine was equivalent to an impurity
level of 5% and by the second-order derivative spectrum, the determination limit
was equivalent to an impurity level of 2%. The degradation of nisoldipine
followed within 30 days and the calculated maximal degradation rate was 1.6% per
day for nisoldipine raw material, but significantly lower values of 0.19 and
0.15% per day were obtained for Nisoldin tablets (10 and 5 mg, respectively).
PMID- 10782383
TI - Determination of fluocortolone pivalate and fluocortolone hexanoate in
suppositories using reverse-phase HPLC.
AB - Fluocortolone and its esters are synthetic corticosteroids used topically in the
treatment of various skin disorders. A method that can be successfully used for
the separation and determination of fluocortolone pivalate and fluocortolone
hexanoate in suppositories was developed. This method is based on reverse-phase
HPLC on Supelcosil LC-18 (25 cm x 4.6 mm, 5 microns), using methanol-acetonitrile
water-glacial acetic acid (17:46:37:0.4 v/v/v/v) as mobile phase at a flow rate
of 3.0 ml/min. Detection was carried out using a UV detector at 238 nm. The
method developed was validated, and calibration curves were established dependent
on peak area. The validated ranges for fluocortolone pivalate and fluocortolone
hexanoate are 15-305 micrograms/ml (r = 0.9995) and 15-315 micrograms/ml (r =
0.9996), respectively. The limits of detection and the limits of quantification
for both esters were also determined.
PMID- 10782385
TI - An efficient method for the synthesis of sulbactam pivoxil.
AB - Sulbactam pivoxil, a prodrug of the beta-lactamase inhibitor sulbactam, was
prepared in high yield by reacting the sodium salt of sulbactam with chloromethyl
pivalate in a polar solvent, then diluting the reaction mixture with water and
isolating the product by filtration. Dimethyl sulfoxide was found to be the
solvent of choice among several aprotic organic solvents.
PMID- 10782386
TI - Comparative LC-MS and HPLC analyses of selected antiepileptics and beta-blocking
drugs.
AB - A highly sensitive and specific assay procedure based on the combination of
liquid chromatography and mass spectrometry (LC-MS) has been developed for the
quantitative analysis of selected antiepileptics (carbamazepine and phenytoin)
and beta-blocking drugs (acebutolol, atenolol, pindolol and propranolol) using
APCI as an ionization process. The measured concentration range was 100-300 ng ml
1 for all drugs except phenytoin (0.5-1.5 micrograms ml-1). Analysis was based on
direct injection of methanolic solutions of drugs into the mass spectrometer with
the subsequent elution with a mobile phase consisting of methanol and 1% acetic
acid solution (4:1) at a flow rate 1 ml min-1. The mass spectrometer was
programmed to permit detection and determination of either fragment or molecular
ions of carbamazepine, phenytoin, acebutolol, atenolol, pindolol and propranolol
at m/e 194.3, 252.9, 337.2, 267.1, 249.1 and 260.1, respectively. The recorded
chromatograms exhibited well-resolved peaks at retention times < 1 min. The peak
area was correlated linearly to the drug concentration. Intraday precision gave
relative standard deviations in the range 1.75-4.02%. Compared to HPLC, the
described LC-MS was faster, more sensitive and specific. Unlike HPLC, LC-MS could
be applied to analyze incompletely resolved mixtures. The absolute detection
limits for LC-MS and HPLC were 0.2-0.5 and 10-25 ng, respectively. Recovery
studies of the investigated compounds in pharmaceutical products using LC-MS and
HPLC gave mean percentages of 97.5-102.0 and 98.4-103.3, respectively.
Statistical analysis of the data using t- and F-tests showed insignificant
differences between both methods for the analysis of carbamazepine, phenytoin,
acebutolol and atenolol in pharmaceutical formulations. However, LC-MS gave more
accurate results than HPLC for determination of pindolol in tablets. Propranolol
could only be determined in tablets using LC-MS.
PMID- 10782387
TI - Synthesis and antimicrobial activity of 1,4-diaryl-2-azetidinones.
AB - Cycloaddition of substituted 4,4-benzylidene-anilines to in situ prepared
dichloroketenes in the presence of dichloroacetyl chloride and triethylamine
affords a variety of 2-azetidinones. All the compounds were characterized by IR
and 1H NMR. Their antimicrobial activity, against Gram(+) and Gram(-) bacteria
and fungi, was tested.
PMID- 10782388
TI - Synthesis and antimicrobial activity of (E)-acetoxystilbenes and alpha,alpha'
dibromoacetoxybibenzyls.
AB - The synthesis of 13 new (E)-acetoxystilbenes and alpha,alpha'
dibromoacetoxybibenzyls and their antimicrobial activity are reported. The
results of microbiological screening of 17 (E)-stilbenols and (E)
acetoxystilbenes, unknown in the literature, have also been discussed. In
particular, coumpounds 1c, 1g, 2a, 3a, 3b, 4a, 6a, 6b showed good antibacterial
activity against Staphylococcus aureus and 1c also against Bacillus subtilis.
PMID- 10782389
TI - Tick-borne viral encephalitis--the threat of summer.
PMID- 10782390
TI - Procalcitonin and C-reactive protein levels in community-acquired pneumonia:
correlation with etiology and prognosis.
AB - BACKGROUND: The diagnostic value of admission serum levels of procalcitonin (PCT)
and C-reactive protein (CRP) as indicators of the etiology and prognosis was
prospectively investigated. PATIENTS: 96 patients, 50-85 years of age, treated in
the hospital for community-acquired pneumonia (CAP). RESULTS: On admission, all
patients had elevated CRP levels (> 10 mg/l), but only 60 patients (54%) had
elevated PCT levels (> 0.1 microgram/l). The severity of disease measured by
APACHE II score was strongly associated with admission levels of PCT (p = 0.006),
but not with CRP. Eight of nine patients with pneumonia caused by atypical agents
had PCT levels < 0.5 microgram/l compared with 6/27 patients with pneumonia
caused by classic bacterial pathogens, mainly Streptococcus pneumoniae (p =
0.03). No such correlation between CRP levels and etiology was found. CONCLUSION:
Our data indicate that in patients admitted to the hospital with CAP, measurement
of PCT gives information about the severity of the disease, and may aid the
physician to differentiate typical bacterial etiology from atypical etiology, and
thereby to choose appropriate initial antibiotic treatment.
PMID- 10782391
TI - Comparison of the epidemiological and clinical features of tick-borne
encephalitis in children and adults.
AB - The aim of this prospective study was to compare epidemiological data and
clinical features in children and adults with tick-borne encephalitis (TBE).
Patients with aseptic meningitis diagnosed at the University Medical Centre,
Department of Infectious Diseases, Ljubljana, Slovenia, from June to August 1997,
in whom the diagnosis of TBE was ascertained by the presence of serum IgM
antibodies against TBE virus, who were serologically negative for Borrelia
burgdorferi sensu lato and had a negative PCR CSF result on enteroviral
infection, were included in the study. Out of 213 patients with aseptic
meningitis, 80 (37.56%) fulfilled inclusion criteria. There were 20 children and
60 adults. In both groups males predominated. Virtually all patients had headache
and fever, and more than 50% suffered from vomiting. The majority of patients in
both groups recalled a tick bite, had a biphasic course of the illness, and was
found to have obviously expressed meningeal signs. In both groups the median CSF
leukocyte count was somewhat lower than 100 x 10(6)/l with a predominance of
lymphocytes. Children were more often given antibiotics during the initial phase
of TBE than adults (p = 0.0095). Several other statistically significant
distinctions (p < 0.05) were found including the frequency of fatigue, malaise,
vertigo, photophobia, myalgias, arthralgias, as well as elevated CSF albumin and
protein concentration, elevated albumin quotient and IgG quotient; all these
findings were more often present in adults. In addition a longer duration of
fever, more frequent need for anti-edematous treatment and longer hospitalization
were found in adults. Direct comparison of clinical and epidemiological
characteristics of TBE in children and adults revealed differences in several
clinical and laboratory features and corroborates the previous conclusion that
TBE in childhood is a milder illness than TBE in adults.
PMID- 10782392
TI - Laboratory findings in tick-borne encephalitis--correlation with clinical
outcome.
AB - Infection with the tick-borne encephalitis virus (TBEV) can result in various
neurological complications. At present, there are little data available on
laboratory findings that might help predict the clinical course and prognosis of
tick-borne encephalitis (TBE). In the present study 100 patients with TBE were
examined in respect to various laboratory parameters potentially characteristic
for the disease and indicative for the prognosis in TBE. Pleocytosis, impairment
of the blood-CSF barrier and intrathecal synthesis of immunoglobulins (IgM > IgG,
IgA) were common findings in most patients. On admission to the hospital, 84% of
the patients presented with an intrathecal synthesis of TBEV-specific IgM and/or
IgG antibodies in the CSF. At follow-up, intrathecal synthesis of TBEV-specific
antibodies was demonstrated in all patients studied within 15 days after the
first examination, but changes of CSF parameters did not correlate with the
clinical course of disease. In contrast to those with moderate course of disease,
patients with severe courses of TBE displayed higher cell counts in the CSF and
lower concentrations of neutralizing antibodies in serum, and more frequently
revealed an intrathecal synthesis of total IgG. TBE-specific oligoclonal IgG
antibodies in the CSF were demonstrated only in three patients with prior,
incomplete, vaccination against TBE. The severe course of disease in individual
patients with TBE may result from a slow or low production of neutralizing
antibodies. In these patients, the more intense damage of the CNS tissue is
reflected by higher cell counts in the CSF. At onset of disease the presence of a
low concentration of neutralizing antibodies in serum and a high cell count in
the CSF might indicate an unfavorable course of TBE.
PMID- 10782394
TI - Pilot study assessing TNF gene polymorphism as a prognostic marker for disease
progression in neonates with sepsis.
AB - In adult postoperative intensive care patients, the biallelic Ncol polymorphism
within the tumor necrosis factor (TNF) locus has been shown to be a genomic
marker for individuals with increased TNF-alpha response and poor prognosis in
severe sepsis. We characterized the genomic distribution and allele frequency of
the Ncol polymorphism in 23 preterm and term neonatal intensive care unit (NICU)
patients with culture-proven sepsis and compared it with clinical and laboratory
characteristics to assess its prognostic value for disease progression. Genotype
analysis demonstrated the following absolute (relative) frequencies: 7 (0.31)
infants were homozygous for the allele TNFB2 (Group A). 12 (0.52) infants were
heterozygous (TNFB1/TNFB2) and four (0.17) infants homozygous for the allele
TNFB1 (Group B). There was no significant difference compared to adult intensive
care patients with severe sepsis (p = 0.31). The median gestational age of all
infants (13 female and ten male) as well as for either group was 28 weeks (range
23-37) with a median birth weight of 845 g (range 560-2,720). The study
population included a total of 16 very low birth weight (VLBW) infants, four in
Group A and 12 in Group B. However, there was no significant difference for
gestational age and birth weight in both groups (p = 0.82 and 0.71,
respectively). Laboratory parameters as maximum and minimum leukocyte and
thrombocyte counts, maximum immature to total neutrophil ratios (ITR), maximum C
reactive protein (CRP) levels, days of CRP levels > 5 mg/l and total days of
antibiotic treatment, were not statistically different in both groups. In total,
three infants (13%) died in consequence of their underlying disease. Two infants
belonged to Group A and one to Group B. The statistical analysis of outcome
variables (mortality, neurological impairment, failure to thrive) was not
possible, because the study population was small and the reasons for poor outcome
and death in these high-risk patients had to be considered multifactorial. In
conclusion, in this pilot study the biallelic Ncol polymorphism within the TNF
locus was not a prognostic marker for disease progression in high-risk NICU
admitted term and preterm infants with culture-proven sepsis. In order to detect
differences in outcome similar to adult postsurgical patients with severe sepsis,
an unfeasibly high number of NICU patients with culture-proven sepsis would need
to be included for a similar study.
PMID- 10782393
TI - Fast and type-specific analysis of herpes simplex virus types 1 and 2 by rapid
PCR and fluorescence melting-curve-analysis.
AB - Diagnosis of central nervous system (CNS) infection with herpes simplex virus
(HSV) requires sensitive and rapid techniques. PCR therefore is considered to be
the diagnostic gold standard in these cases. However, current PCR protocols are
time-consuming and labor-intensive. In addition, the need for post-amplification
manipulations increases the risk of laboratory contaminations with amplified
products. In order to improve conventional PCR techniques we compared our current
semiautomated HSV-PCR-ELISA assay with a new micro-volume rapid-cycle PCR system
that combines real-time monitoring and fluorescence melting-curve analysis
without the need for post-amplification sample manipulations. Spiking experiments
with supernatants of tissue culture-grown HSV type 1 (HSV-1) and type 2 (HSV-2)
in HSV-negative control cerebrospinal fluid (CSF) and sterile water revealed that
the new rapid cycle PCR protocol is as sensitive and specific as the PCR-ELISA.
Furthermore, a mismatch (G:T) within the probe-targeted region of the HSV-2
glycoprotein B gene decreases the probe/product melting temperature (Tm) from 69
degrees C for HSV-1 to 64 degrees C for HSV-2, enabling the simultaneous
identification of the two HSV genotypes by melting-curve analysis within one run.
This type specificity of the system was confirmed with 30 genital swabs
previously analyzed for the presence of HSV-1/2 in cell culture. While our
current PCR-ELISA method needs up to 1 day from sample preparation to result
generation, the new procedure takes only 1 h. We consider this system as a
promising new tool for the analysis of HSV DNA in CSF and in other human body
fluids as well as for the diagnosis of other infectious agents where rapid
diagnosis, high sensitivity and specificity are required.
PMID- 10782395
TI - Low correlation of serology with detection of Chlamydia trachomatis by ligase
chain reaction and antigen EIA.
AB - The aim of the present study was to evaluate the diagnostic accuracy of serology
by using new assays for the detection of genus and species-specific IgG, IgM, IgA
and secretory IgA antibody in female sex workers. Cervical swabs and first void
urine (FVU) from 314 female sex workers were submitted to nucleic acid
amplification by ligase chain reaction (LCx, Abbott). Concomittantly, blood
samples were tested for the presence of IgG, IgM and IgA antibodies using a genus
specific assay (rELISA, Medac) and species-specific test (SeroCT, Orgenics).
Chlamydia trachomatis infection was detected in a total of 30 (9.6%) female sex
workers by LCR. With rELISA, seroprevalences for IgG, IgM, and IgA antibody to
Chlamydia were 88.9%, 19.1% and 62.7%, respectively. IgG and IgA antibody
prevalences against C. trachomatis (SeroCT) were 65.0% and 23.9%, respectively.
In comparison to the positive LCR results obtained from cervical swab and/or FVU,
the sensitivity of rELISA for Chlamydia IgG, IgA and IgM detection was 93.3%,
83.3% and 16.7%, respectively. With SeroCT, the sensitivity for C. trachomatis
specific IgG and IgA detection was 86.7% and 33.3%, respectively. The
specificities of both serologic tests in comparison to LCR were very low. In
conclusion, the correlation of serology with active C. trachomatis infection of
the lower genital tract is very low. According to our results, serologic testing
for Chlamydia can exclude active infection of the lower genital tract with a high
reliability (> or = 95%). However, detection of C. trachomatis can only be
reliably achieved by nucleic acid amplification assays.
PMID- 10782396
TI - Tuberculosis in an area bordering east London: significant local variations when
compared to national data.
AB - From September 1996 to June 1997, in an area bordering East London, we
prospectively collected epidemiological, clinical and microbiological data on all
patients with newly diagnosed culture-positive tuberculosis and compared these to
national data based on notifications. The significant differences were that
tuberculosis was diagnosed almost exclusively in non-Caucasian patients (42/47
[89%]) and that there was a high percentage of extrapulmonary tuberculosis (27/47
[57%]) including four cases of tuberculous meningitis and five cases of
osteomyelitis. We also observed that 19/27 (70%) of patients with extrapulmonary
tuberculosis had normal chest X-rays, 3/17 (18%) sub-Saharan Africans were HIV
antibody-positive and drug resistance strains were isolated from six sub-Saharan
Africans and one Caucasian. Figures for treatment failures and mortality compared
favorably to national averages at 6 months. National data do not accurately
reflect local epidemiology and clinical presentations. Hospital-based
surveillance and promoting awareness of local differences is essential to prevent
delayed diagnosis, inappropriate management and poor clinical outcome.
PMID- 10782397
TI - Hospitalization and complications in children under 2 years of age with
Bordetella pertussis infection.
AB - We prospectively followed 725 children under 2 years of age with laboratory
diagnosed Bordetella pertussis infection to investigate the hospitalization rate
and complications. Diagnosis was made by culture and polymerase chain reaction
(PCR) from nasopharyngeal swabs in 11,016 children who presented with > or = 7
days of cough at 63 pediatric practices in Germany. Of these children, 33 (4.5%)
were hospitalized at a mean age of 4.8 months (range, 17 days to 19.5 months).
Complications occurred in 16 (48%) of the 33 patients. Pneumonia developed in two
(6%) children and a convulsion was observed in one (3%). Intensive care
monitoring was required for 23 (70%) children. Further complications were
bradycardia (21%), apnea (12%), conjunctivitis (12%), loss of weight (12%),
otitis media (6%), atelectasis (3%) and dehydration (3%). Children aged 6-24
months who had not received any dose of pertussis vaccine had a ten-fold
increased risk of hospitalization compared to those who had been partially or
fully immunized (p < 0.05). Pertussis immunization should be given at an early
point in time and completely in order to prevent severe courses of pertussis and
hospitalization in young children.
PMID- 10782398
TI - Polymerase chain reaction as a diagnostic tool for detecting Leishmania.
AB - Polymerase chain reaction (PCR) has been used to identify a Leishmania parasite
in a cutaneous ulcer from a 27-year-old patient infected during travel in Peru.
The available classical diagnostic methods could not confirm the diagnosis in a
sufficiently short time. Therefore, two sets of oligonucleotides were designed
and with both of them fragments of the expected size were obtained. The sequence
of the fragment derived from kinetoplast DNA corresponds to the Leishmania
Viannia complex. Polymerase chain reaction has advantages over classical
diagnostic methods, which makes it an important technique in those hospitals and
clinical laboratories in Europe which lack standard diagnostic tests for
Leishmania.
PMID- 10782399
TI - Streptococcus pneumoniae peritonitis postpartum.
AB - A peritonitis caused by an ascending infection is a rare complication postpartum.
A 37-year-old woman presented with a secondary peritonitis due to Streptococcus
pneumoniae. The patient had given birth to a healthy boy 4 weeks before and
showed no symptoms of a bronchitis on admission. An operation was performed after
the patient developed an acute abdomen, showing a diffuse peritonitis. High
vaginal swabs and blood cultures taken on admission were positive for S.
pneumoniae as well as the specimen taken during the operation. Thus we concluded
that this was a case of an ascending infection. After antibiotic therapy with
penicillin the patient could be discharged 8 days after the operation.
PMID- 10782400
TI - Visceral manifestation of cat scratch disease in children. A consequence of
altered immunological state?
AB - A 12-year-old girl with a 2-month history of fever and abdominal pain was
admitted to our hospital. Ultrasound and CT scans of the abdomen showed multiple
hypoechoic lesions of liver and spleen. Screening for zoonosis revealed high
positive titers to Bartonella henselae. T-cell deficiency was demonstrated and
remained almost unchanged during a follow-up of 11 months. A review of the
literature shows that disseminated visceral affection is a rare presentation of
cat scratch disease (CSD) in childhood and adolescence. Further immunological
investigations are needed in more patients with CSD to confirm whether an altered
immunological state may be responsible for the atypical visceral manifestation of
CSD.
PMID- 10782401
TI - A case of paracoccidioidomycosis: experience with long-term therapy.
AB - We describe long-term therapy for paracoccidioidomycosis occurring in a 61-year
old house-painter from Venezuela. The diagnostic examinations made in South
America had shown pulmonary granulomatous lesions and an osteolytic pattern of
the left knee that had been considered suspect of malignant disease with an
indication for limb amputation. With the aid of fine needle aspiration biopsy
(FNAB) and culture examination we diagnosed an osteomyelitis by Paracoccidioides
brasiliensis and initiated therapy with itraconazole, 400 mg per day, reduced to
200 mg per day after 2 months. At the end of 2 years of drug therapy, we observed
complete regression of the pulmonary lesions and of the osteolytic area of the
left knee. Moreover, we have periodically observed our patient to verify his
clinical development and he is still in good health. We suggest that this
pathology be considered in differential diagnosis of leprosy, tuberculosis,
leishmaniasis, and systemic mycoses, even in non-endemic areas.
PMID- 10782403
TI - Cutaneous manifestations in brucellosis: case report and review of the
literature.
AB - Brucellosis is a classical common zoonotic disease of worldwide distribution.
Skin complications are infrequent and affect less than 5% of patients with
brucellosis, although they may occasionally occur during the clinical course of
the disease. Here, we report a case of a shepherd presenting with fever and a
diffuse maculopapular rash due to Brucella melitensis infection, and we provide a
review of the relevant literature.
PMID- 10782402
TI - Listeria meningitis in children: report of two cases.
AB - We report two cases of meningitis caused by Listeria monocytogenes in children.
The first patient was a healthy 14-month-old boy and the second patient a 3-year
old girl with Byler disease which, however, is not reported as a predisposing
factor for listeriosis. We present these cases because Listeria infection,
although common in neonates, is extremely infrequent during infancy and
childhood.
PMID- 10782404
TI - Expression of retinoic acid receptors in non-neoplastic epithelial disorders of
the vulva and normal vulvar skin.
AB - Retinoids and their nuclear retinoic receptors (RARs) are important modulators of
epidermal cell proliferation and terminal differentiation. Aberrant expression of
RARs in the epidermis has been found to be associated with altered
differentiation capacity of keratinocytes. In this study, the expression of the
various types of RARs (RAR-alpha, RAR-beta, and RAR-gamma) was investigated in
surgical specimens from 17 patients with vulvar lichen sclerosus, 12 patients
with vulvar squamous cell hyperplasia, and 11 specimens of normal vulvar skin by
nonradioactive in situ hybridization. The results demonstrate that RAR-alpha
expression is significantly decreased in lichen sclerosus (p < 0.0001) and
squamous cell hyperplasia (p = 0.007) compared with normal vulvar skin.
Furthermore, in normal vulvar skin RAR-alpha mRNA is mainly located in the
suprabasal epidermal cell layers, whereas in lichen sclerosus RAR-alpha is
expressed predominantly in the basal cell layers. In squamous cell hyperplasia
RAR-alpha expression occurs in all cell layers. Compared with normal vulvar skin,
RAR-gamma expression is higher in lichen sclerosus (p = 0.026), but no
statistically significant differences are seen in squamous cell hyperplasia.
These results suggest that partial loss and abnormal localization of RAR-alpha
expression as well as increased RAR-gamma expression may play a role in the
etiology of non-neoplastic epithelial disorders of the vulva.
PMID- 10782405
TI - Primary vulvar and vaginal extraosseous Ewing's sarcoma/peripheral
neuroectodermal tumor: diagnostic confirmation with CD99 immunostaining and
reverse transcriptase-polymerase chain reaction.
AB - Two cases of extraosseous Ewing's sarcoma/peripheral neuroectodermal tumor
arising in unusual, superficial sites are reported. One tumor involved the
vaginal wall of a 35-year-old woman, and the other neoplasm arose in the dermis
of the vulva in a 28-year-old woman. The tumors showed characteristic microscopic
features of Ewing's sarcoma/peripheral neuroectodermal tumor with nodular
monotonous proliferations of undifferentiated, small, round, hyperchromatic cells
with a low mitotic index. Rare rosette-like formations were apparent only in the
vulvar neoplasm. The tumors displayed intense immunoreactivity in a membranous
pattern for CD99, the cell surface glycoprotein encoded by the MIC2 gene.
Genetically, the tumors expressed the EWS/FLI-1 chimeric transcript, derived from
the t(11;22)(q24;q12) chromosomal translocation. Both patients had localized
disease treated with wide local excision; one received postoperative
chemotherapy, and the other received chemotherapy and radiotherapy. To date, 18
and 19 months after diagnosis, neither patient has had clinical evidence of local
recurrence or metastasis. To our knowledge, these are the first reported cases of
vaginal and vulvar Ewing's sarcoma/peripheral neuroectodermal tumor, confirmed
with molecular genetic analysis, in the English literature.
PMID- 10782406
TI - Well-differentiated villoglandular adenocarcinoma of the uterine cervix:
oncogene/tumor suppressor gene alterations and human papillomavirus genotyping.
AB - Twelve well-differentiated villoglandular adenocarcinomas (WDVAs) of the uterine
cervix were retrospectively analyzed for the presence and specific genotype of
human papillomavirus (HPV), tumor suppressor loss (p53, MCC, APC, BRCA1), cancer
gene mutation (K-ras-2, exons 1 and 2, p53 exons 5 to 8), and oncogene
amplification (c-erbB-2/HER-2/neu, int-2). Tissue for genetic evaluation was
obtained by microdissection, using 4-micron-thick histology sections of archival,
formalin-fixed, paraffin-embedded specimens. Genotyping involved nucleic acid
amplification and DNA sequencing with gene-specific oligonucleotides and L1
region consensus primers for common strains of HPV. Point mutation and HPV strain
determination were accomplished by DNA sequence analysis. Tumor suppressor gene
loss and oncogene amplification were performed by allelic imbalance analysis in
informative subjects based on DNA sequence and microsatellite-length
polymorphisms. HPV was present in all tumors and consisted of type 16 (n = 5,
42%) and type 18 (n = 7, 58%) strains, which have been closely associated with
cervical neoplasia. K-ras-2 and p53 genes did not manifest point mutational
damage. There was no evidence of oncogene amplification or tumor suppressor gene
loss. The presence of HPV in all 12 tumors supports the role of HPV infection in
the molecular pathogenesis of this uncommon neoplasm. The absence of associated
oncogene or tumor suppressor gene damage is consistent with indolent biological
behavior and the favorable prognosis of this unusual tumor.
PMID- 10782407
TI - The patterns of expression of an apoptosis-related CK18 neoepitope, the bcl-2
proto-oncogene, and the Ki67 proliferation marker in normal, hyperplastic, and
malignant endometrium.
AB - Expression of a neoepitope on cytokeratin 18, recognized by the monoclonal
antibody M30, is an early indicator of apoptosis in epithelial cells. The aim of
this study was to determine the equilibrium between apoptosis (M30), anti
apoptosis (bcl-2), and proliferation (Ki-67) in different endometrial conditions.
Paraffin-embedded samples (n = 107), representing proliferative endometrium (18),
secretory endometrium (19), postmenopausal endometrium (15), disordered
proliferative endometrium (6), simple hyperplasia (12), complex hyperplasia (8),
and endometrial adenocarcinoma (29), were evaluated immunohistochemically. The
indirect streptavidin-biotin-horseradish peroxidase technique, with 3-amino-9
ethylcarbazole as the chromogen, was used to visualize the reactions.
Proliferative endometrium showed high bcl-2 and Ki-67 expression levels with no
M30. In the secretory phase, the balance was tipped in favor of M30 with a
decrease of bcl-2 and Ki-67. Postmenopausal endometrium revealed high Ki-67 and
bcl-2 expression levels and no M30. In complex hyperplasia, M30, bcl-2, and Ki-67
showed increased expression. In endometrial carcinoma, an increasing reactivity
for M30 and Ki-67 was seen as the grade progressed. bcl-2 reacted weakly and only
in grade 1 cancer. Immunohistochemistry facilitates the study of the expression
of proteins related to cyclic endometrial activity. Interruption of these cyclic
events is associated with specific disturbances in the expression patterns of
these proteins.
PMID- 10782408
TI - Endometrial endometrioid carcinomas associated with Ewing sarcoma/peripheral
primitive neuroectodermal tumor.
AB - Three uterine tumors, each consisting of endometrioid carcinoma and Ewing's
sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) are described. The
diagnosis of ES/pPNET in each case was first established in the hysterectomy
specimen because each ES/pPNET was misinterpreted on the endometrial biopsy
specimens as a high-grade homologous sarcoma. The ES/pPNET element in each case
consisted of solid masses of small- to medium-sized round cells without Homer
Wright pseudorosettes, glial or ganglion cells, true rosettes with central
lumens, or medulloepithelial tubules. Each ES/pPNET exhibited focal positive
immunostaining for neuron-specific enolase, diffuse staining for vimentin, and
strong cell membrane immunoreactivity for O13 (CD99), the last finding providing
the first clue to the diagnosis of ES/pPNET in each case. The diagnosis in each
case was confirmed by detection of EWS/FLI-1 fusion transcript through reverse
transcription polymerase chain reaction. We also examined O13 immunoreactivity
retrospectively in 40 cases of malignant mixed mullerian tumors (MMMT) with
homologous or heterologous elements. O13 immunoreactivity was not observed in the
malignant epithelium or in the homologous or heterologous sarcomas. The
immunoreactivity of O13 in round cell endometrial sarcomas provides a clue to the
diagnosis of ES/pPNET.
PMID- 10782409
TI - Endometrial carcinoma and non-Hodgkin's lymphoma involving the female genital
tract: a report of three cases.
AB - The occurrence of both non-Hodgkin's lymphoma and carcinoma involving the female
genital tract of the same patient is rare; we describe three such cases. In case
1, a 56-year-old woman with endometrioid endometrial carcinoma had synchronous
follicular lymphoma of the uterus and ovary. In case 2, a 57-year-old woman with
diffuse large B-cell lymphoma of the uterine cervix presented 5 years later with
an endometrioid endometrial carcinoma. In case 3, a 69-year-old woman with an
endometrioid endometrial carcinoma presented with a diffuse large B-cell lymphoma
of the vagina 3 years later. In two patients, the non-Hodgkin's lymphoma was
unsuspected clinically and would have been missed without biopsy and tissue
diagnosis.
PMID- 10782410
TI - Mucosal epithelial proliferation of the fallopian tube: prevalence, clinical
associations, and optimal strategy for histopathologic assessment.
AB - The prevalence and clinical significance of mucosal epithelial proliferation or
hyperplasia of the fallopian tube are controversial in the few studies reported.
Some authors have retrospectively examined "routine" sections (one or two
submitted from each tube), whereas others have prospectively blocked the entire
tubes. In the current study, we prospectively studied a total of 168 tubes from
98 women who had various indications for salpingectomy and compared the diagnosis
in an initial single section (to simulate the usual practice) with that in the
remainder of the entirely sectioned and submitted tube (mean total number of
sections, 9.0). Some degree of mucosal epithelial proliferation was found in 83%
of all tubes examined, with no difference between the tubes removed for routine
tubal ligation and those in women who had benign ovarian lesions, malignant
gynecologic tumors, uterine leiomyomata, or benign tubal lesions (salpingitis or
ectopic pregnancy). Mucosal epithelial proliferation graded as more than mild,
however, was seen in only 4.5% of the otherwise normal ligated tubes versus 35 to
46% of tubes associated with the other lesions. When the initial sections were
compared with the subsequent ones, the diagnosis was identical in 96 tubes (57%).
In the other 72 tubes (43%), the difference in diagnosis was never greater than
one grade (no, mild, moderate, severe mucosal epithelial proliferation), with the
diagnosis more often upgraded (50 tubes) than downgraded (22 tubes) in the
additional sections. It is concluded that there is no reason to submit an entire
tube for histologic examination to detect clinically significant lesions, and the
usual practice of submission of one or two sections is clinically appropriate.
PMID- 10782411
TI - Recurrent fallopian tube carcinoma: TP53 mutation and clinical course.
AB - Primary fallopian tube carcinoma is a rare, aggressive gynecological cancer;
little is known about its cause. Previous studies have indicated that p53
immunopositivity is correlated with short-term survival in primary fallopian tube
carcinoma. We examined p53 and p21/WAF1 immunostaining and TP53 mutation in exons
5 to 8 by single-stranded conformation polymorphism and constant denaturant gel
electrophoresis in nine cases of primary fallopian tube carcinoma and their
metastases/recurrences from patients who survived for between a few months and
more than 20 years after diagnosis. We found that 1.) p53 immunopositivity
without detectable p21/WAF1 immunostaining did not correlate with TP53 mutations
in the conserved domains; 2.) mutations in TP53 occurred in two
metastases/recurrences but not in their corresponding primary tumors; 3.) in two
cancers, a TP53 mutation was observed in the primary tumor but not in the
metastases/recurrences; 4.) constant denaturant gel electrophoresis seems to be
more sensitive than single-stranded conformation polymorphism in detecting TP53
mutations; and 5.) in the nine cases studied, p53 immunoreactivity and/or TP53
mutation analysis did not correlate with tumor progression, survival, or response
to treatment.
PMID- 10782412
TI - Loss of heterozygosity on chromosome 17q in epithelial ovarian tumors:
association with carcinomas with serous differentiation.
AB - Loss of heterozygosity (LOH) on chromosome 17q is frequent in epithelial ovarian
tumors, but its clinicopathologic significance remains to be elucidated. DNA of
50 patients with epithelial ovarian tumors was extracted from blood and from
fresh-frozen and paraffin-embedded tissue (14 benign, 7 borderline, and 29
malignant). Six microsatellite loci were amplified by PCR (D17S250, TRHA1,
D17S800, D17S855, D17S579, D17S513). LOH was scored by the absence or reduction
of the signal to less than 50% of one of the alleles in tumor DNA compared with
normal DNA. LOH was identified on chromosome 17q in at least one locus in 12
tumors (24%), all of them carcinomas (12 of 29 tumors, 41.3%). It occurred more
frequently among high-grade serous carcinomas (8 of 14 tumors, 57%) and mixed
endometrioid-serous carcinomas (2 of 5, 40%). LOH was detected in all informative
markers of 10 tumors, suggesting the complete loss of an entire chromosome 17
homologue. Patients with LOH-positive carcinomas were older than those with LOH
negative malignant tumors (mean ages 67 and 49). The results support the
hypothesis that LOH on chromosome 17q may be associated with the development of
ovarian cancers in elderly patients, particularly with high-grade serous or mixed
endometrioid-serous carcinomas.
PMID- 10782413
TI - Immunohistochemical detection of the Wilms' tumor gene (WT1) in epithelial
ovarian tumors.
AB - The Wilms' tumor gene WT1 plays multiple roles in the development of the
genitourinary organs and Wilms' tumors. The aims of this study were to
immunohistochemically evaluate WT1 expression in normal female genital tissues
and in epithelial ovarian tumors and to look for correlations between WT1
expression and histologic subtypes and cell proliferation in epithelial ovarian
tumors. In normal female genital organs, WT1 expression was recognized in ovarian
surface epithelium, the lining of inclusion cysts, and tubal epithelium, but not
in the cervical or endometrial epithelium. In epithelial ovarian tumors, serous
tumors generally revealed a high WT1 expression. Among adenocarcinomas, serous
carcinoma revealed a significantly higher WT1 expression than the other
histologic subtypes. There were no significant correlations between the WT1
labeling index and the Ki-67 labeling index, and no significant difference in
survival between those showing high and low WT1 expression among the malignant
cases. These results suggest that WT1 expression may be related to cell
differentiation, and that the histologic subtypes of epithelial ovarian
carcinomas may differ considerably in their biological characteristics.
PMID- 10782414
TI - Atypical solitary fibrous tumor of the vulva.
AB - An atypical solitary fibrous tumor (SFT) was encountered as a slow-growing, 15
cm, well-demarcated, vulvar tumor in a 70-year-old woman. The tumor was highly
cellular and composed predominantly of hemangiopericytomatous and capillary
hemangioma-like proliferations and short fascicular arrangements of spindled
cells. Multinucleated giant cells and tumor necrosis also were present. The tumor
cells were positive for vimentin, CD34, progesterone receptors, and bcl-2 and
were diploid by flow cytometry. The patient was well without disease 9 months
after surgery. Awareness of the occurrence of atypical SFT in the vulva is
important so that confusion with other neoplasms can be avoided.
PMID- 10782415
TI - Primary ovarian rhabdomyosarcoma associated with clear cell carcinoma of the
ovary: a case report and review of the literature.
AB - The clinicopathologic and immunohistochemical findings of a case of coexistent
primary ovarian rhabdomyosarcoma and clear cell carcinoma of the ovary are
reported. The tumor was detected in a 41-year-old premenopausal woman who had a 1
year history of pelvic pain. On physical examination, a 14.0-cm left adnexal mass
was found for which a hysterectomy with bilateral salpingo-oophorectomy and
staging biopsies were performed. The tumor was composed of solid and cystic
areas, and two distinct microscopic components were identified: clear cell
carcinoma and rhabdomyosarcoma. Immunoperoxidase studies demonstrated that the
neoplastic cells in the latter component were positive for desmin, muscle
specific actin, and myoglobin. A biopsy taken from the pelvic peritoneum revealed
rhabdomyosarcoma (FIGO stage IIB). Despite two cycles of chemotherapy, the
disease persisted in the pelvis 4 months after diagnosis.
PMID- 10782416
TI - Adenocarcinoma of the uterine cervix with choriocarcinomatous and hepatoid
differentiation: report of a case.
AB - A case of adenocarcinoma of the uterine cervix that showed choriocarcinomatous
and hepatoid differentiation was encountered in a 65-year-old woman. She
presented with genital bleeding and had multiple metastatic nodules in the lungs.
At operation, a large, hemorrhagic, and necrotic tumor was found in the uterine
cervix. The major portion of the tumor consisted of typical choriocarcinoma
admixed with minor areas of hepatoid carcinoma and endocervical adenocarcinoma.
Human chorionic gonadotropin and alpha-fetoprotein were detected in tumor cells
in the choriocarcinomatous and hepatoid areas, respectively. The patient died of
pulmonary metastasis 4 months after the operation. The coexistence of
choriocarcinomatous and hepatoid carcinoma in an endocervical adenocarcinoma has
not been reported previously. Both heterotopic components were probably derived
from aberrant differentiation (or neometaplasia) of the somatic epithelial cells
of the endocervical adenocarcinoma.
PMID- 10782417
TI - Ectopic production and localization of beta-human chorionic gonadotropin in
lymphoepithelioma-like carcinoma of the cervix: a case report.
AB - A 32-year-old woman underwent a suction curettage for missed abortion. The
initial serum human chorionic gonadotropin (beta-hCG) level was 40 IU/ml. The
histologic examination of the uterine curettage specimen showed scant strips of a
poorly differentiated malignant neoplasm and no chorionic villi. The tumor showed
strong immunoreactivity for cytokeratin (AE1/AE3) and beta-hCG but no reactivity
for human placental lactogen. The combination of histologic appearance, beta-hCG
immunoreactivity, and elevation of serum beta-hCG raised a strong suspicion for
epithelioid trophoblastic tumor (ETT). Postcurettage serial serum beta-hCG levels
remained in the range of 20 to 45 micrograms/ml. Computerized tomographic scan
showed a 1.0-cm circumscribed mass in the upper endocervix. A radical
hysterectomy and pelvic lymphadenectomy were performed. Gross examination of the
hysterectomy specimen likewise showed a well-circumscribed mass in the upper
endocervix. Histologic examination revealed an undifferentiated carcinoma
accompanied by intense lymphoplasmacytic infiltrate. A final diagnosis of
lymphoepithelioma-like carcinoma (LELC) was rendered. LELC with elevated serum
beta-hCG level and immunoreactivity to beta-hCG should be distinguished from ETT
in a small endocervical curettage sample.
PMID- 10782419
TI - Bizarre leiomyoma of the vagina: report of a case.
AB - Smooth muscle tumors are the most common mesenchymal tumors of the adult vagina,
but no case of bizarre (also referred to as atypical, symplastic, or pleomorphic)
leiomyoma has been described at this site. We present such a case in a 44-year
old woman.
PMID- 10782418
TI - Uterine adenolipoleiomyoma: a rare hamartomatous lesion.
AB - An apparently unique intramural uterine lesion is described for which we propose
the name adenolipoleiomyoma. On gross examination, a well-circumscribed white
intramural mass contained focal fatty areas. Histology showed the mass to be
composed of smooth muscle, adipose tissue, and endometrial, endocervical, and
tubal type glands. The endometrial glands were surrounded by typical endometrial
stroma. There was no evidence of adenomyosis in the uterus outside the lesion.
This is only the second report of such a lesion within the uterus and the first
with an intramural location. We believe it to be a benign hamartomatous lesion.
PMID- 10782420
TI - Unilateral salpingitis due to enterobius vermicularis.
AB - A case of unilateral salpingitis caused by Enterobius vermicularis presenting as
a painful adnexal mass in a 28-year-old woman is reported.
PMID- 10782421
TI - Ovarian dysplasia identified by cul-de-sac aspiration: a reexamination of
previously reported cases.
PMID- 10782422
TI - Tumor markers in ovaries at risk of developing carcinoma.
PMID- 10782423
TI - Psychosocial care by general practitioners--where are the problems? Results of a
demonstration project on quality management in psychosocial primary care.
AB - OBJECTIVE: Since 1987, psychosocial services have been a part of the primary care
setting in Germany. In the framework of an eight-center national demonstration
program, problems in the diagnosis and therapy of psychosocial problems and
psychosomatic disorders were assessed. Methods to improve quality were also
implemented. METHOD: General practitioners (n = 191) from six regions
participated in the study. One thousand three hundred and forty-one treatment
episodes of patients with predominantly psychosocial symptoms were documented.
Differences between psychosocial strain, treatment, and outcome were determined
by analyses of variance. RESULTS: Anxiety (62%), depression (51%), and
marital/family conflicts (44%) were the most frequent symptoms. Psychosocial
treatment was offered more often to those patients who had the highest level of
anxiety and depression. Patients with pain and without a psychological
attribution to their illnesses were offered less psychosocial treatment and
suffered worse results. Partners and family members were rarely integrated into
therapy. The procedures employed to improve outcome were quality circles, family
oriented case conferences, consultation services, and collaborative groups.
CONCLUSIONS: These initial results are promising. A process of internal quality
management has been initiated. Some of the physicians still resist documenting
the data. Patients with somatic symptoms without psychological attribution may
need special psychosocial interventions to improve their outcomes.
PMID- 10782425
TI - Burnout in nursing staff: is there a relationship between depression and burnout?
AB - OBJECTIVE: There is evidence that burnout may be a clinical entity with
pathological stress reaction features related to the inability in finding
pleasure from work. The purpose of this study was to investigate the relationship
between burnout and depression. METHODS: The study took place in the general
hospital AHEPA of Thessaloniki. All members of the nursing staff (in total 368
subjects) took part. The protocol was self-reported and anonymous, in order to
obtain as valid data as possible and included the Maslach Burnout Inventory (MBI)
to assess the level of burnout, the Eysenck Personality Questionnaire (EPQ) to
assess personality traits, and the Zung Self-Rating Depression Scale to assess
depressive symptomatology. RESULTS: The analysis revealed a weak but significant
relationship between burnout and depression. CONCLUSIONS: Depression is a
pervasive disorder that affects almost every aspect of the patient's life. On the
contrary, burnout is, by definition, a syndrome restricted to the patient's
professional environment. However, it seems that there may be two distinct types
of burnout syndromes, of which the one comprising the majority of nurses has
little or no common features with depression. The second type consists of
individuals with a predisposition to develop burnout. The latter is characterized
by more severe symptomatology, phenotypic similarity to depression and presumably
common etiological mechanisms.
PMID- 10782424
TI - Psychological distress in healthy women with familial breast cancer: like mother,
like daughter?
AB - OBJECTIVE: In 1977, the Israel Cancer Association held a one-day conference, on
the subject of familial breast cancer, for healthy women with at least one first
degree relative diagnosed with breast cancer. The objective of this study was to
assess the psychological distress of a sample of the women who attended. METHOD:
Of the 333 healthy women present at the conference, 230 completed three
questionnaires: one on sociodemographic data and the medical history of the first
degree relative(s) (mother and/or sister), and two that measure psychological
distress: the Brief Symptom Inventory and the Impact of Events Scale. SAMPLE: The
subjects were divided into three categorical groups: those whose mother had
breast cancer (group A, N = 176), those whose sister had breast cancer (group B,
N = 34), and those whose mother and sister both had the disease (group C, N =
20). In addition, subjects were divided into two groups according to the
psychological distress level. RESULTS: Analysis of results (using ANOVA and a Chi
square test for categorical variables and both univariate and multivariate
procedures for psychological distress assessment) showed elevated levels of
distress and persistent intrusive thoughts in all groups, and particularly in
group C. CONCLUSION: There is a need to promote genetic diagnostic and
appropriate counseling, notwithstanding the potential risks that genetic
counseling poses for such women.
PMID- 10782426
TI - Multiple sclerosis presenting as catatonia.
AB - OBJECTIVE: Catatonic disorder due to general medical condition must be excluded
in psychiatric patients presenting with this movement disorder. This report
emphasizes the association of catatonia with multiple sclerosis. METHOD: A
patient with catatonia, psychotic depression, and the subsequent diagnosis of
multiple sclerosis is described and the literature reviewed. RESULTS: Mutism,
immobility, cataplexy, waxy flexibility, and other aspects of catatonia occur in
multiple sclerosis, usually as a consequence of a severe mood disorder and
extensive cerebral demyelination. These symptoms may be the presenting
manifestations of multiple sclerosis. CONCLUSIONS: A high index of suspicion for
neurological disease is indicated in patients with new-onset catatonia.
Neuroimaging and other studies may reveal underlying demyelination requiring
specific therapy.
PMID- 10782427
TI - Comment: Global climate warming and the efficacy of therapeutic agents in
psychiatry.
PMID- 10782428
TI - Seeing things from a different angle: the pigeon's recognition of single geons
rotated in depth.
AB - In 2 experiments involving computer-rendered versions of single shapes or
"geons," the extent to which depth rotation affects the visual discrimination
performance of pigeons in both go/no-go and forced-choice tasks was documented.
The pigeons were able to recognize geons at most rotations in depth; however, the
pigeons' recognition performance was better at the training view than at most
other views. Aspects of these results are both consistent with and problematic
for object-centered and viewer-centered theories of object recognition.
PMID- 10782429
TI - Display variability and spatial organization as contributors to the pigeon's
discrimination of complex visual stimuli.
AB - Three experiments assessed the contributions of display variability and spatial
organization to the pigeon's discrimination of 16-icon visual displays. After
training to discriminate 4 x 4 arrays of same and different computer icons, 4
pigeons were shown testing displays that systematically manipulated the
variability of the depicted icons and their spatial organization on the display
screen. Display variability and spatial organization each reliably controlled the
pigeon's behavior. These seemingly separate effects could be collectively
explained by the pigeon's discriminating the amount of variability or entropy in
localized regions of the display.
PMID- 10782430
TI - Conditioning the unconditioned response: modification of the rabbit's
(Oryctolagus cuniculus) unconditioned nictitating membrane response.
AB - Conditioning-specific reflex modification (CRM) occurs when classical
conditioning modifies responding to an unconditioned stimulus (US) in the absence
of a conditioned stimulus (CS). Three experiments monitored rabbit nictitating
(Oryctolagus cuniculus) membrane unconditioned responses to 5 intensities and 4
durations of periorbital electrical stimulation before and after CS or US
manipulation. CRM occurred after 12 days of CS-US pairings but not following
unpaired CS/US presentations or restraint. CRM survived CS-alone and CS/US
unpaired extinction of the conditioned response (CR) but not presentations of the
US alone, although CRs remained intact. Thus, CRs could be weakened without
eliminating CRM and CRM could be weakened without eliminating CRs. Data indicate
CRM is a reliable, associative effect that is more than a generalized CR and may
not be explained by habituation, stimulus generalization, contextual
conditioning, or bidirectional conditioning.
PMID- 10782431
TI - Contextual control over conditioned responding in a latent inhibition paradigm.
AB - We used 1-, 2-, and 3-context designs to study the control exerted by contexts
over freezing in rats exposed to a conditioned stimulus (CS) in advance of its
pairing with a shock unconditioned stimulus. The latent inhibition observed when
preexposure, conditioning, and testing occurred in the same context was
attenuated if preexposure occurred in a different context to conditioning and
testing. Latent inhibition (i.e., attenuated performance) was restored in a CS
specific manner if preexposure and testing occurred in the same context and
conditioning in a different one. Latent inhibition was also reduced by a long
retention interval but remained specific for a particular context-CS relation.
Finally, CS preexposure resulted in contextual control over the expression of
excitatory conditioned performance. The results are discussed in terms of memory,
associative, and associative-performance models of CS-preexposure effects.
PMID- 10782432
TI - Contextual control over conditioned responding in an extinction paradigm.
AB - Four experiments studied contextual control over rats' freezing to conditioned
stimuli (CSs) that had been paired with shock and were then extinguished. In
Experiment 1, rats were exposed to a CS A-shock and a CS B-shock pairing in
Context C. CS A was then extinguished in Context A, and CS B in Context B.
Freezing was renewed when each CS was presented in the context where the other CS
had been extinguished. In Experiments 2-4, rats were exposed to a CS A-shock
pairing in A and a CS B-shock pairing in B. They were then exposed to Context C
where one, both, or neither of the CSs were extinguished, or where both CSs
continued to be reinforced. On test, the rats froze more to CS A than to CS B in
Context A, and more to CS B than to CS A in Context B, but only if the CSs had
been extinguished. Thus, after extinction, rats use contexts to regulate
retrieval not only of their memory for extinction, but also of their memory for
the original conditioning episode.
PMID- 10782433
TI - The influence of passive preexposure on escape from a Morris pool.
AB - In 3 experiments rats were preexposed to the landmarks that surround a Morris
pool by being placed on a submerged platform within the pool. They were then
required to escape from the pool by swimming to the platform, which was in a
location that had not been used during preexposure. Preexposure facilitated
subsequent escape from the pool, provided that the platform was not moved during
preexposure and the relative position of the landmarks to each other remained
constant throughout preexposure. In contrast, if during preexposure the platform
was moved from session to session (Experiment 1), or the array of landmarks was
altered unsystematically from trial to trial (Experiments 2 and 3), then
subsequent learning to escape from the pool was disrupted. These findings suggest
that the effects of preexposure to the landmarks in a Morris pool is determined
by whether or not they are of relevance for identifying the location of the
platform. When they are relevant, then subsequent learning is facilitated, but
when they are irrelevant, then subsequent learning is disrupted.
PMID- 10782434
TI - Quantitative analysis of risk sensitivity in honeybees (Apis mellifera) with
variability in concentration and amount of reward.
AB - Free-flying honeybees (Apis mellifera) were trained in a series of experiments
designed to look for evidence of risk sensitivity in foraging for sucrose
solution. The suitability of the choice method used was established in 3
preliminary experiments with differences in concentration, amount, and
probability of reward. Of 5 subsequent experiments in which 2 alternatives
provided the same mean concentration of sucrose solution with different variance,
3 showed risk indifference, and 2 showed risk aversion (preference for consistent
reward). Of 2 final experiments in which the alternatives provided the same mean
amount of sucrose solution with different variance, both showed risk aversion.
Performance could be simulated quantitatively with a simple choice model
developed by P. A. Couvillon and M. E. Bitterman (1991) to account for the
results of a wide range of previous experiments on discriminative learning in
honeybees.
PMID- 10782435
TI - Stimulus and temporal cues in classical conditioning.
AB - In 2 experiments, separate groups of rats were given stimulus conditioning,
temporal conditioning, untreated control and (in Experiment 2) learned
irrelevance control procedures, followed by a compound with both stimulus and
temporal cues. Stimulus conditioning consisted of a random 15-s duration
conditioned stimulus (CS) followed by food; temporal conditioning consisted of
food-food intervals of fixed 90 s (Experiment 1) or fixed 75 + random 15 s
(Experiment 2). The stimulus group abruptly increased responding after CS onset,
and the temporal group gradually increased responding over the food-food
interval. When the food-food interval was fixed 90 s, the temporal cue exerted
stronger control in the compound, whereas when the food-food interval was fixed
75 + random 15 s, the stimulus cue exerted stronger control. The strength of
conditioning, temporal gradients of responding, and cue competition effects
appear to reflect simultaneous timing of multiple intervals.
PMID- 10782436
TI - Stimulus repetition effects on texture-based visual search by pigeons.
AB - Four experiments investigated the effects of within-session stimulus repetition
on texture discrimination. Six pigeons (Columba livia) searched for a contrasting
target region (color or shape) randomly embedded within a larger distractor
region for food reinforcement. Experiment 1 found that repeating features of the
distractors, but not those of the target, across trials increased the accuracy of
target localization relative to baseline. Experiment 2 found that subsequently
switching the identity of a repeated distractor feature to the target decreased
accuracy. Experiment 3 found that the effects of repeating a distractor feature
influenced search performance for at least 60 trials after this learning.
Experiment 4 found that differential stimulus-outcome relations can produce
control by repeated target features. The results are discussed in terms of the
factors and strategies involved in the control of avian visual search behavior.
PMID- 10782437
TI - Evaluative conditioning in the picture-picture paradigm with random assignment of
conditioned stimuli to unconditioned stimuli.
AB - Human participants were allocated to 1 of 3 groups. In the conditioning group,
each conditioned stimulus (CS)-unconditioned stimulus (US) pair was presented 7
times during the acquisition phase. Participants who were assigned to the
extinction group saw 5 additional presentations of each CS in isolation after the
7 presentations of each CS-US pair. In the latent inhibition group, the CS-only
trials were presented before the CS-US trials. Overall, a significant evaluative
conditioning effect was observed. This effect cannot be dismissed on the basis of
the arguments developed by A. P. Field and G. C. L. Davey (1997, 1998, 1999), and
the results thus provide strong evidence for the associative nature of evaluative
conditioning. The results are also in line with other findings, which showed that
evaluative conditioning is resistant to extinction.
PMID- 10782438
TI - Study for verification testing of the helmet-mounted display in the Japanese
Experimental Module.
AB - Our purpose is to propose a research and development project in the field of
telemedicine. The proposed Multimedia Telemedicine Experiment for Extra-Vehicular
Activity will entail experiments designed to support astronaut health management
during Extra-Vehicular Activity (EVA). Experiments will have relevant
applications to the Japanese Experimental Module (JEM) operated by National Space
Development Agency of Japan (NASDA) for the International Space Station (ISS). In
essence, this is a proposal for verification testing of the Helmet-Mounted
Display (HMD), which enables astronauts to verify their own blood pressures and
electrocardiograms, and to view a display of instructions from the ground station
and listings of work procedures. Specifically, HMD is a device designed to
project images and data inside the astronaut's helmet. We consider this R&D
proposal to be one of the most suitable projects under consideration in response
to NASDA's open invitation calling for medical experiments to be conducted on
JEM.
PMID- 10782439
TI - Electromagnetic interference with electronic medical equipment induced by
automatic conveyance systems.
AB - Electromagnetic interference (EMI) with electronic medical equipment induced by
automatic conveyance systems is estimated. We measured the electric intensities
of electromagnetic waves transmitted by three self-controlled electric truck
systems. We also observed EMI with an infusion pump and a syringe pump set 1 m
from the rail. The maximum electric field intensity was observed at the supplied
current frequency in two systems with non-contact power supply mechanisms. The
highest value, 137.0 dB microV/m, was measured just beside the rail. This is
higher than the international electromagnetic immunity standard limit for
electronic medical equipment. EMI may occur if electronic medical equipment is
used within 2 m of the rail when the system contains an inductive power supply
mechanism. With a contact power supply mechanism, the electric field intensity
was much lower than that of the immunity standard. EMI should not occur even when
electronic medical equipment is used just beside the rail.
PMID- 10782440
TI - A question and answer E-mail system for responding to query from the general
public with which the system manager can identify delayed replies.
AB - We constructed a question and answer system for direct delivery of E-mail queries
from the general public to the proper hospital representative and with which the
system administrator can monitor E-mail replies. The system consists of two sub
systems; one is an E-mail questionnaire sub-system that automatically delivers E
mail queries to the proper person and an E-mail reply monitor sub-system with
which the system administrator can monitor the E-mail replies. The monitor system
compares the origin address of the E-mail reply and the destination address on a
questionnaire filled out at the time the query is made. In a test of the system,
56 queries were received in 31 days, with 37 replied to. The interval from
receipt of an E-mail query to reply was calculated. Nineteen replies were
submitted within 2 days.
PMID- 10782441
TI - Redesigning the medical office for improved efficiency: an object-oriented event
driven messaging system.
AB - Medical practitioners are under ever increasing pressure to maximize patient
care, while minimizing costs. One productivity area that has not previously
undergone thorough investigation is the efficient utilization of time for intra
office communication. Medical office personnel typically need to communicate
patient information and resource requests, as well as personal messages. An intra
office communication system is designed that reduces time-waste typically
incurred in medical office environments. Redesigning medical offices with intra
office communication systems provides time savings of several man hours per day.
The subsequent increase in time efficiency enables higher quality of patient care
and larger patient loads to be managed by existing medical staff.
PMID- 10782442
TI - A simple client-server system using a personal computer as the server.
AB - Hospital information systems have recently grown into huge, complex systems. As a
result, the cost of development and maintenance of application programs has
increased and become a serious problem. We have constructed an order entry system
using server-client architecture as part of a hospital intranet information
system in which a personal computer is used as a server. Using a commercial
database management system and software development tools, an easily maintained
order entry system was developed within only three months by one programmer.
Since slow response when the number of clients increased was possible, we
measured turn-around times when one or ten clients accessed simultaneously. Turn
around times were 8 and 10 sec, respectively. Because we expect much better
performance from personal computers in the near future, application systems using
personal computers as Intranet servers will be cost and time effective and easy
to develop and maintain.
PMID- 10782443
TI - The art of building decision trees.
AB - Decision support systems that help physicians are becoming a very important part
of medical decision making. They are based on different models and the best of
them are providing an explanation together with an accurate, reliable, and quick
response. One of the most viable among models are decision trees, already
successfully used for many medical decision-making purposes. Although effective
and reliable, the traditional decision tree construction approach still contains
several deficiencies. Therefore we decided to develop and compare several
decision support models using four different approaches. We took statistical
analysis, a MtDeciT, in our laboratory developed tool for building decision trees
with a classical method, the well-known C5.0 tool and a self-adapting
evolutionary decision support model that uses evolutionary principles for the
induction of decision trees. Several solutions were evolved for the
classification of metabolic and respiratory acidosis (MRA). A comparison between
developed models and obtained results has shown that our approach can be
considered as a good choice for different kinds of real-world medical decision
making.
PMID- 10782444
TI - Validation of the Spanish version of the Changes in Sexual Functioning
Questionnaire (CSFQ).
AB - The aim of this study is to adapt and validate the Changes in Sexual Functioning
Questionnaire (CSFQ) in Spanish. The CSFQ was administered to 206 depressed
patients in different Spanish cities, to 326 health sciences students at the
University of Oviedo, and to 48 workers undergoing routine health check-ups. The
Hamilton Depression Rating Scale (HAM-D) was administered to the depressed
patients. The average time spent answering the CSFQ was 15.19 minutes. The CSFQ
discriminated the depressed patients from the workers and university students. In
the three areas of reliability (internal, test-retest, and inter-rater), the
coefficients obtained were greater than 0.80. The factor analysis demonstrated
differences in the internal construct of the American CSFQ and its Spanish
equivalent. The psychometrc properties of the Spanish version of the CSFQ
indicate that it is a valid instrument for clinical use in treating depressed
patients.
PMID- 10782445
TI - Sildenafil for psychotropic-induced sexual dysfunction in 31 women and 61 men.
AB - Ninety-two outpatients (31 women, 61 men) who were treated with oral sildenafil
for psychotropic-induced sexual dysfunction (PISD) completed ratings of their
sexual functioning pre- and posttreatment. Both women and men reported
significant improvements (p = .001) in all domains of sexual functioning, with
88% reporting improvement in overall sexual satisfaction. Significant
improvements were reported regardless of psychotropic medication type. However,
patients taking selective serotonin re-uptake inhibitors reported less
improvement in arousal, libido, and overall sexual satisfaction than did other
patients, whereas patients taking benzodiazepines reported significantly more
improvement in libido and overall sexual satisfaction. Oral sildenafil may be an
effective treatment for PISD.
PMID- 10782446
TI - Satisfaction in the sex life of a general population sample.
AB - A questionnaire asking about satisfaction and problems in the sex lives of
respondents and their partners was sent to 4,000 adults registered with general
practices in England. A quarter of respondents said that they were dissatisfied
with their sex lives, men more so than women, particularly with the frequency of
intercourse. Respondents were more likely to be dissatisfied with their sex life
if they perceived their partner to have a sexual problem. Respondents who were
dissatisfied were more likely to report that their partner was dissatisfied with
their sex life. The benefits of treating sexual problems have wide implications
for both partners in a relationship.
PMID- 10782447
TI - Characteristics of the ideal sex partner: gender differences and perceptions of
the preferences of the other gender.
AB - The objective of the current study was to further examine gender differences in
preferences for particular characteristics in a sexual partner and to investigate
the extent to which men and women accurately estimate the preferences of the
other gender. Heterosexual college students (185 men, 244 women) rated a diverse
set of characteristics in a hypothetical sexual partner with whom they were
presumed to be involved in an ongoing relationship. Participants also responded
to the same set of items with regard to estimates of the ratings of the other
gender (order of presentation was counter-balanced). Although there was notable
similarity in what men and women most valued in a potential long-term sex
partner, there were gender differences with regard to ratings of several of the
items. Also, men and women under- or overestimated the ratings of the other
gender with regard to several characteristics. Results are discussed with regard
to implications for intervention as well as directions for future research.
PMID- 10782449
TI - Perceived premarital counseling outcomes among recently married army personnel.
AB - Data from 1,285 recently married soldiers who participated in the 1989 Army
Family Research Program survey indicated that premarital counseling by itself had
little effect on subsequent marital satisfaction. However, those who had
premarital counseling were more likely to use marital and family therapy
services, at both subclinical and clinical levels of distress, than others who
had not had such counseling before marriage.
PMID- 10782448
TI - The relationship between perceived dysfunctional family-of-origin rules and
intimacy in young adult dating relationships.
AB - This study examined the relationship between perceived dysfunctional family-of
origin rules and intimacy in single young adult dating relationships. A sample of
754 single, Caucasian-American young adults completed measures of perceived
dysfunctional family-of-origin rules and emotional, intellectual, and sexual
intimacy in dating relationships. When controlling for the effects of gender and
age, results showed that perceived dysfunctional family-of-origin rules had a
negative impact on the perceived expression and experience of these three kinds
of intimacy in dating relationships. Implications for relationship therapy are
discussed.
PMID- 10782450
TI - Evaluation of clitoral blood flow by color Doppler ultrasonography.
AB - The feasibility of reliably measuring clitoral blood flow using standard color
Doppler ultrasonography was evaluated by two independent assessors in a sample of
40 pre- and post-menopausal women. High positive correlations with no significant
mean differences between examiners were found for three major standard blood flow
measures including maximum velocity, resistance, and pulsatility indices. With
further methodological refinements, ultrasonographic evaluation of clitoral blood
flow will be adaptable for clinical and research use and is likely to become the
standard physiological measure of female sexual arousal.
PMID- 10782451
TI - The Female Sexual Function Index (FSFI): a multidimensional self-report
instrument for the assessment of female sexual function.
AB - This article presents the development of a brief, self-report measure of female
sexual function. Initial face validity testing of questionnaire items, identified
by an expert panel, was followed by a study aimed at further refining the
questionnaire. It was administered to 131 normal controls and 128 age-matched
subjects with female sexual arousal disorder (FSAD) at five research centers.
Based on clinical interpretations of a principal components analysis, a 6-domain
structure was identified, which included desire, subjective arousal, lubrication,
orgasm, satisfaction, and pain. Overall test-retest reliability coefficients were
high for each of the individual domains (r = 0.79 to 0.86) and a high degree of
internal consistency was observed (Cronbach's alpha values of 0.82 and higher)
Good construct validity was demonstrated by highly significant mean difference
scores between the FSAD and control groups for each of the domains (p < or =
0.001). Additionally, divergent validity with a scale of marital satisfaction was
observed. These results support the reliability and psychometric (as well as
clinical) validity of the Female Sexual Function Index (FSFI) in the assessment
of key dimensions of female sexual function in clinical and nonclinical samples.
Our findings also suggest important gender differences in the patterning of
female sexual function in comparison with similar questionnaire studies in males.
PMID- 10782452
TI - [Clinical characteristics of familial rheumatoid arthritis in Spain. A study of
73 families. Spanish Consortium for Rheumatoid Arthritis (CEAR) and European
Consortium for Familial Rheumatoid Arthritis (ECRAF)].
AB - OBJECTIVE: To describe clinical characteristics and the homogeneity of disease
expression between involved members in multicase Spanish rheumatoid arthritis
(RA) families. PATIENTS AND METHODS: 73 families with two or more siblings with
RA were found, with a total of 149 patients distributed in 79 pairs (70 sib
pairs, and 3 sib trios). Demographic, clinical and radiological characteristics
were recorded in a standard questionnaire. RESULTS: Clinical characteristics were
similar to those of sporadic RA with a high frequency of women (78%), positive
rheumatoid factor (RF) (86%), erosions (89%) and a 25% of the patients having
extraarticular disease. The most important variable in disease severity was
disease duration. The concordance between family members of the same age and
calendar year of disease onset, and the pattern of disease expression, was not
higher than expected, showing that the disease is heterogenic. CONCLUSION:
Environmental factors seem to be more important in RA susceptibility. Clinical
characteristics of familiar RA in Spain do not seem to be different from sporadic
RA, although differences were found in disease expression within families that
may be due to variation of genetic or environmental factors, responsible for the
susceptibility and disease duration.
PMID- 10782453
TI - [Lowering high levels of fasting total homocysteine with folic acid and vitamins
B in patients with venous thromboembolism: relationship between response and the
C677T methylenetetrahydrofolate reductase (MTHRF) genotype].
AB - BACKGROUND: High levels of plasma total homocysteine (tHcy) are involved in
arterial or venous occlusive diseases. It essentially depends on the nutritional
status of folic acid (FA) and vitamins B12 or B6, but also on the
methylenetetrahydrofolate reductase (MTHFR) enzymatic activity. We aim to
evaluate the response of the hyperhomocysteinemia (HHcy) to a standard schedule
of vitamin supplementation, according with the MTHFR genotype. PATIENTS AND
METHODS: 227 patients, diagnosed with venous thromboembolism (VTE) were analysed
for tHcy (in fasting conditions), and for the MTHFR-C677T gene polymorphism. When
the tHcy exceeded the cut-off point (men = 16, women = 15 mumol/l), the patients
were supplemented with a dose equivalent to 1 mg FA, 0.2 mg B12 and 100 mg of B6,
daily by 6 weeks. Afterwards they were reanalysed and the reduction was
stratified by MTHFR genotype, looking for any difference in the response.
RESULTS: The mean fasting tHcy was 12.3 mumol/l (SD = 8). The 51
hyperhomocysteinemic patients (22%) were older (65.1 y) than the normal ones
(55.0 y) (p = 0.0001). The treatment was carried out properly in 46 patients
(90%). The pre-treatment mean Hcy was 23.2 (SD = 10.5) mumol/l, and it was
reduced to 13.0 (SD = 5.9) (p = 0.0001) (mean reduction = 42.1%). By genotype,
the C/C reduced from 21.0 to 13.2 mumol/l (37%) (n = 18), the C/T from 25.0 to
12.6 mumol/l (46%) (n = 24), and the abnormal homozygotes T/T from 22.7 to 14.5
mumol/l (39%) (n = 4), although no statistical significant differences were
found. In 80% of cases (37/46), tHcy values normalised. A negative correlation (r
= -0.471) (p = 0.005) was observed between age and response. CONCLUSIONS: The
FA/B6/B12 based therapy reduces in a simple, quick and effective way (> 40% in 6
weeks) the pathologic tHcy levels on a VTE population and this is not influenced
by the MTHFR genotype. As HHcy seems related with recurrences of venous
thrombosis, we could speculate if it would be useful to analyse routinely the
tHcy, attempting reduction in selected cases.
PMID- 10782454
TI - [Phenotypic expression of Lp(a) in Spanish children and adolescents].
AB - BACKGROUND: To know the distribution of phenotypes Lp(a) in an young population.
METHODS: Lipoprotein levels, lipoprotein(a), apolipoproteins and the Lp(a)
phenotypes were determined in 105 children, selected according to their
cholesterol concentrations. RESULTS: The Lp(a) concentrations were significantly
higher in group with low molecular weight respect to group with high molecular
weight. The most frequent isoform was S3. CONCLUSIONS: The Lp(a) concentrations
correlate inversely with the molecular weight of Apo(a) isoforms.
PMID- 10782455
TI - [Genetics of rheumatoid arthritis].
PMID- 10782456
TI - [Hodgkin's disease in patients infected by the human immunodeficiency virus.
Study of fifteen cases].
AB - BACKGROUND: In spite of not being considered as an AIDS defining illness,
Hodgkin's disease (HD) has specific clinical and biological features in HIV
infected patients. PATIENTS AND METHODS: Study of clinicopathologic and analytic
characteristics, Epstein-Barr virus (EBV) detection (polymerase chain reaction),
and prognosis in 15 patients with HD and HIV infection. RESULTS: Thirteen
patients had B symptoms, 10 extranodal involvement and 12 advanced HD. The most
frequent histologic subtypes were mixed cellularity (6) and lymphocyte depletion
(6). The mean (SD) of CD4 lymphocytes was 0.10 (0.08) x 10(9)/l. The presence of
EBV in lymph node biopsy was demonstrated in 3 out of 4 patients investigated.
Complete remission (CR) was achieved in 7 out of 14 treated cases (50%), the
median overall survival was 26 months and the 2 year event-free survival
probability was 60%. CONCLUSIONS: In HIV-infected patients, HD presents in
advanced stages, unfavourable histologic subtypes, frequent extranodal
involvement and B symptoms. The prognosis is poor, mainly because of a low CR
rate.
PMID- 10782457
TI - [Sociologic overview of quality life].
PMID- 10782458
TI - [New perspectives in the nonpharmacological treatment of atrial fibrillation].
PMID- 10782459
TI - [What are cryptogenic hepatic diseases?].
PMID- 10782460
TI - [Penetrating aortic ulcer: an unreported cause of massive digestive hemorrhage].
PMID- 10782461
TI - [Exchange blood transfusion and P. falciparum malaria].
PMID- 10782463
TI - [Usefulness of bone marrow examination in the diagnosis of fever of unknown
origin in patients infected by human immunodeficiency virus].
PMID- 10782462
TI - [Acute bilateral ophthalmoplegia with raised anti-GQ1b antibodies].
PMID- 10782464
TI - Prognostic implication of human papillomavirus infection in squamous cell
carcinoma of the lung.
AB - On the subtropical island of Okinawa, squamous cell carcinoma (SCC), particularly
the well-differentiated form, is the most frequent type of lung cancer, while
this form is relatively rare on the Japanese mainland and in other countries.
Furthermore, in Okinawa, in 1993, 80% of SCC cases of the lung were found to be
infected with human papillomavirus (HPV). We studied the prognosis of SCC of the
lung with HPV infection (n = 25) and compared it with non-HPV-infected SCC (n =
16). Using the Kaplan-Meier method (Wilcoxon analysis), the prognosis of HPV
infected cases was found to be better than that of the non-infected cases. In the
virus-infected cases, apoptosis and infiltration of a large number of Langerhans
cells were demonstrated. In addition to these findings, the virus-infected tumors
were demonstrated to be histologically well-differentiated, perhaps contributing
to the favorable prognosis. However, among the virus-infected cases, the type 16
virus-infected cases showed a poorer prognosis, compared to those infected with
other HPV types. p53 gene mutation was also examined, and was considered to be an
unfavorable prognostic factor, as reported elsewhere. However, in Okinawa, HPV
positive cases with p53 mutations showed a slightly better prognosis than did non
viral infected cases with p53 mutations. The TNM staging system was also useful
for categorizing the virus-infected cases. The prognosis of stage III (A and B)
cases was poor. All of our present cases received surgical treatment.
Chemotherapy and radiation therapy were not performed. Such treatment, however,
might be effective, because virus-infected uterine cervical carcinomas have been
routinely treated with chemotherapy and radiation. Furthermore, if the
immunological basis of increased Langerhans cell infiltration in HPV-infected
cases is elucidated, a clinical trial with immunotherapy may be favorable for the
clinical outcome.
PMID- 10782465
TI - Expression of stromelysin and urokinase type plasminogen activator protein in
resection specimens and biopsies at different stages of osteoarthritis of the
knee.
AB - This study aimed at assessing the possible diagnostic value of cartilage biopsies
as a convenient marker for cartilage matrix degradation. We therefore examined
cartilage specimens from 56 patients with primary osteoarthritis (OA) of the
knee. Resection and biopsy cartilage specimens obtained during joint replacement
surgery were used for this study. In addition to histomorphology,
immunohistochemistry (ICH) was performed to determine the expression levels and
distribution patterns of stromelysin and u-PA protein. The latter data were
compared with the degree of histomorphological changes in osteoarthritic
cartilage samples, based on a modified version of Mankin's grading score.
Compared to the cartilage resection specimens, the biopsies showed comparable
expression patterns for both proteinases: the strongest signals were noted in the
superficial zone and, as matrix destruction increased, also in the chondrocytes
of the transition and deep zones. The strongest signals were ascertained in cell
clusters beneath deep matrix fissures. At the immunohistochemical level, we found
a direct correlation in the expression of MMP-3 and u-PA between resection
specimens and biopsies. Furthermore, in both types of cartilage samples, we
noticed a positive relationship between the expression of both proteins and the
Mankin score. Analysis of the expression levels revealed significant differences
between deep, transition and superficial zones. Histomorphological and
immunohistochemical examinations of MMP-3 and u-PA in biopsies of osteoarthritic
cartilage turned out to be useful for estimating the pathological changes within
osteoarthritic knee joints. Therefore, in future, cartilage biopsies from
osteoarthritic knee joints might serve as a diagnostic tool and thus have an
influence on further therapeutic strategies.
PMID- 10782466
TI - Evaluation of numerical abnormalities of chromosomes 1 and 17 in proliferative
epithelial breast lesions using fluorescence in situ hybridization.
AB - Our aim was to investigate the putative role of chromosome abnormalities of
chromosomes 1 and 17 in the process of breast carcinogenesis. Numerical
abnormalities of chromosomes 1 and 17 were investigated using fluorescence in
situ hybridisation (FISH) in a series of 16 primary invasive breast carcinomas
associated with intraductal proliferative epithelial lesions. Chromosome 1
aneusomy was detected in 55.6% of ductal hyperplasia (DH), 81.8% of ductal
carcinomas in situ (DCIS) and 87.5% of invasive ductal carcinomas (IDC).
Chromosome 17 aneusomy was not detected in the cases of DH and was present in
90.9% of DCIS and in 87.5% of IDC. Simultaneous aneusomy of chromosome 1 and 17
was found in 81.8% of DCIS and in 75.0% of IDC. Our results showed that the
number of chromosome 1 and 17 copies increases from normal epithelium to invasive
cancer. The numerical abnormalities of chromosome 1 were already detected in DH,
suggesting that a gain in the copy number of chromosome 1 may be involved early
in breast carcinogenesis.
PMID- 10782467
TI - T311--an anti-tyrosinase monoclonal antibody for the detection of melanocytic
lesions in paraffin embedded tissues.
AB - Tyrosinase is a key enzyme in melanin biosynthesis and represents a marker of
melanocytic differentiation. We previously generated T311, a murine monoclonal
antibody to the tyrosinase recombinant protein. This study was performed to
evaluate T311 as a diagnostic immunohistochemical reagent for use on formalin
fixed paraffin-embedded pathological material. We analyzed the specificity of the
antibody on a panel of normal and neoplastic tissues, and we assessed its
sensitivity in a large number of metastatic and primary malignant melanomas,
nevi, three angiomyolipomas, and two vitiligo specimens. T311 revealed intense
reactivity on paraffin-embedded material. Immunoreactivity was limited to cells
of melanocytic differentiation and no immunostaining was present in unrelated
normal tissues and tumors. Eighty-four percent of metastatic malignant melanomas
were immunoreactive with T311 and showed predominantly a homogeneous expression
pattern. However, in primary melanomas of the desmoplastic/spindle cell type,
T311 revealed a poor immunoreactivity. Nevi showed intense staining at the
junctional zone, while the dermal component revealed decreasing reactivity
towards deeper areas. Only one angiomyolipoma was focally immunoreactive with
T311. Vitiligo specimens were immunonegative. We conclude that T311 is a specific
and sensitive marker for the detection of melanocytic lesions in formalin-fixed
paraffin-embedded tissues and a useful serological reagent for diagnostic
pathology.
PMID- 10782469
TI - Increased fractal complexity of the epithelial-connective tissue interface in the
tongue of 4NQO-treated rats.
AB - The effect of the carcinogen 4-nitroquinoline 1-oxide (0.001% in drinking water)
on the irregularity of the epithelial connective tissue interface (ECTI) of the
ventral surface of the tongue was quantified in Dark Agouti and Wistar Furth
rats. Histological tongue sections stained with the Azan-Mallory method were
digitised (111 images, resolution 1 pixel = 3.1 microns), and the limit between
epithelium and stroma of the ventral surface was extracted and analysed using a
fractal geometry technique (local connected dimension). The results showed that
although none of the images included carcinomas on the ventral surface of the
tongue (all cases had other oral carcinomas), the epithelial profiles of the
treated cases showed a statistically significant increase in irregularity when
compared to controls. Canonical discriminant analysis of the parameters
describing the irregularity of the ECTI classified 81.1% of the images in the
original groups (treated or control). Fractal analysis is capable of detecting
subtle architectural changes in the oral epithelium of the rat occurring after
exposure to the carcinogen, even when full malignant transformation has not yet
taken place. Fractal analysis, which may prove useful for monitoring the
progression of carcinogenesis in this animal model, is a morphometrical parameter
in the diagnosis of oral epithelial dysplasia.
PMID- 10782468
TI - Expression of p27kip1 and p53 in medulloblastoma: relationship with cell
proliferation and survival.
AB - p27kip1 and p21cip1 are cyclin-dependent kinase (cdk) inhibitors which along with
p53 play critical roles in the control of cell cycle progression. Accumulation of
p27kip1 in post-mitotic neurons is a major event of neurogenesis. We hypothesized
that a dysregulation of the expression of p53 and these cdk inhibitors underlies
cellular proliferation in medulloblastomas, and tested this hypothesis by
investigating p27kip1, p21cip1, Bcl2 and p53 immunoreactivity in 14
medulloblastoma tumors. We noted an inverse relationship between p27kip1
expression and cellular proliferation (MIB1). Focal islands of neuroblastic or
glial differentiation expressed high levels of p27kip1, while the
undifferentiated, highly-proliferative population of tumor cells showed no
detectable p27kip1 expression, thus suggesting a role for p27kip1 in cell cycle
control in medulloblastoma. In addition, there was no detectable p21cip1
expression in any of the medulloblastomas studied. The low level of apoptosis
displayed by these tumors was not associated with the expression of Bcl-2. A
significant relationship was found between detection of p53 protein and poor
survival. Since, p21cip1 and p27kip1 are often co-expressed with other INK4
family of cdk inhibitors during the induction of cellular differentiation and are
synergistic in their effect, a deregulation of their coordinate expression may
underlie the lack of complete differentiation in medulloblastoma.
PMID- 10782470
TI - The role of sialylated Lewis antigens on hematogenous metastases of human
pancreas carcinoma cell lines in vivo.
AB - Previous studies have shown that sialyl Lewis a (SLea) and sialyl Lewis x (SLex)
correlated to hematogenous metastasis of human cancers. Although SLea/SLex and E
selectin act as a set of adhesion molecules in vitro, it is not clear whether the
in vivo correlation is exclusively mediated by the adhesion function. To address
this issue, we investigated whether or not the role of SLea/SLex antigens on
hematogenous metastasis to the liver in SCID mice was exclusively mediated by
adhesion by using antibodies for these antigens and SLea/SLEx-negative, human
pancreas adenocarcinoma cell line PCI-6. The absence of SLea/SLex expression was
supported by the absent flow cytometric detection of the antigens as well as by
the absent attachment augmentation to activated endothelial cells. PCI-6 cells
are xenotransplantable to nude and SCID mice and produce vascular endothelial
cell growth factor (VEGF) in a significant amount. PCI-6 cells, 1 x 10(6), were
injected into the spleens of SCID mice, and resultant liver metastases were
evaluated six weeks later. We observed an inhibitory effect on the establishment
and growth of metastatic colonies when anti-SLea or anti-SLex antibody was
administered. This indicates that SLea/x antigens have an important in vivo role,
even in the metastasis of SLea/SLex-negative tumor cells. This implies that there
may be an in vivo function of SLea/x antigens other than that of the attachment
between tumor and endothelial cells.
PMID- 10782471
TI - Adult mesoblastic nephroma with ciliated epithelium. A case report.
AB - A case of renal pelvic tumors occurring in a 44-year-old man is reported. There
were two polypoid renal pelvic tumors which consisted of glandular and stromal
components. Some glands in the tumors had ciliated epithelium and were quite
similar to the epididymal tubules. Other glands in the tumors resembled the
collecting duct or the mesonephric remnant seen in female genitalia.
Immunohistochemistry and electron microscopy revealed smooth muscle
differentiation of the stromal cells of these tumors. Some psammoma bodies were
seen in the glands of the tumors. We diagnosed these tumors as adult mesoblastic
nephroma (MN). The patient has been followed up for 14 months, showing no
evidence of recurrence. Differentiation of the tumors from angiomyolipoma,
leiomyoma, and nephrogenic adenofibroma is discussed. Adult renal tumors that
consist of epithelial and stromal components have been reported under various
names. They constitute clinicopathologically different entities originating from
pediatric MN. We suggest that these tumors should be termed "adult MN".
PMID- 10782472
TI - Parachordoma of the tibia: report of a rare case.
AB - We report a case of recurrent parachordoma of the left anterior tibial region in
a 64-year-old male patient. The tumor was a periosteal tender mass, and,
histologically, displayed vague nodules of spindle to rounded eosinophilic cells
embedded in a myxoid matrix. Large vacuolated (physalphorouslike) cells were
noted as in sacrococcygeal chordoma. This tumor should be differentiated from
myxoid chondrosarcoma, myxoid liposarcoma, chondromyxoid fibroma, and metastatic
chordoma. The presence of physaliphorous cells in the tumor with positive
immunoreactions caused by cytokeratin rules out the diagnosis of another myxoid
tumor. The differential diagnosis from metastatic chordoma is basically made by
clinicians. Even though parachordoma is usually regarded as a benign soft tissue
neoplasm, two recurrences occurred in our case. Since the reported cases,
including ours, have diverse clinical courses, it is essential to follow-up the
patient carefully.
PMID- 10782473
TI - Benign mixed epithelial and stromal tumor of the kidney.
PMID- 10782474
TI - Growth charts, low birth weight, and international adoption.
PMID- 10782475
TI - The risks are many, but the joys are great.
PMID- 10782476
TI - Preadoption review of medical records.
PMID- 10782477
TI - Medical evaluation and infectious considerations on arrival.
PMID- 10782478
TI - Initial assessment of growth, development, and the effects of
institutionalization in internationally adopted children.
PMID- 10782479
TI - Long-term medical issues in international adoptees.
PMID- 10782480
TI - Behavioral sequelae of orphanage life.
PMID- 10782481
TI - The Internet and international adoption information.
PMID- 10782482
TI - Resident's column: international adoption.
PMID- 10782483
TI - A comparative multi-centre study of the efficacy of propolis, acyclovir and
placebo in the treatment of genital herpes (HSV).
AB - Ninety men and women with recurrent genital HSV type 2 participated in a
randomized, single-blind, masked investigator, controlled multi-centre study
comparing the efficacy of ointment of Canadian propolis containing natural
flavonoids with ointments of acyclovir and placebo (vehicle) on healing ability
and capacity to remedy symptoms. Thirty individuals were randomized to each
group. Treatment was intended to start in the blister phase. All participants had
HSV type 2 isolated, confirmed by serum immunoglobulin levels. The participants
were examined on the 3rd, 7th and 10th days of treatment by gynaecologists,
dermatovenerologists or urologists at seven different medical centres. Apart from
clinical symptoms the number and size of the herpetic lesions were noted. At each
examination the lesions were classified into four stages: vesicular, ulcerated,
crusted and healed. The study ointments were applied to affected areas four times
daily. In women with vaginal or cervical lesions a tampon with the appropriate
ointment was inserted four times daily for 10 days. Endpoint variables were
healing time and time until loss of symptoms. RESULTS: On Day 10, 24 out of 30
individuals in the propolis group had healed. In the acyclovir group 14 out of 30
and in the placebo group 12 out of 30 had healed. (p = 0.0015). The healing
process appeared to be faster in the propolis group. In the propolis group 15
individuals had crusted lesions on Day 3 compared to 8 individuals in the
acyclovir group and none in the placebo group (p = 0.0006). On Day 7, 10
participants in the propolis group, 4 in the acyclovir group and 3 in the placebo
group had healed. At the initial examination all patients had local symptoms and
28% general symptoms. At Day 3, 3 patients in the propolis group had local
symptoms compared to 8 and 9 in the acyclovir and placebo groups respectively. Of
the women, 66% had vaginal superinfections of microbial pathogens at the initial
examination. In the acyclovir and placebo groups no change in the vaginal flora
was found following treatment whereas in the propolis group the incidence of
superinfection was reduced by 55%. (p = 0.10 n.s.). CONCLUSION: An ointment
containing flavonoids appeared to be more effective than both acyclovir and
placebo ointments in healing genital herpetic lesions, and in reducing local
symptoms.
PMID- 10782484
TI - Antioxidant and cyclooxygenase inhibitory phenolic compounds from Ocimum sanctum
Linn.
AB - Anti-oxidant bioassay-directed extraction of the fresh leaves and stems of Ocimum
sanctum and purification of the extract yielded the following compounds;
cirsilineol [1], cirsimaritin [2], isothymusin [3], isothymonin [4], apigenin
[5], rosmarinic acid [6], and appreciable quantities of eugenol. The structures
of compounds 1-6 were established using spectroscopic methods. Compounds 1 and 5
were isolated previously from O. sanctum whereas compounds 2 and 3 are here
identified for the first time from O. sanctum. Eugenol, a major component of the
volatile oil, and compounds 1, 3, 4, and 6 demonstrated good antioxidant activity
at 10-microM concentrations. Anti-inflammatory activity or cyclooxygenase
inhibitory activity of these compounds were observed. Eugenol demonstrated 97%
cyclooxygenase-1 inhibitory activity when assayed at 1000-microM concentrations.
Compounds 1, 2, and 4-6 displayed 37, 50, 37, 65, and 58% cyclooxygenase-1
inhibitory activity, respectively, when assayed at 1000-microM concentrations.
Eugenol and compounds 1, 2, 5, and 6 demonstrated cyclooxygenase-2 inhibitory
activity at slightly higher levels when assayed at 1000-microM concentrations.
The activities of compounds 1-6 were comparable to ibuprofen, naproxen, and
aspirin at 10-, 10-, and 1000-microM concentrations, respectively. These results
support traditional uses of O. sanctum and identify the compounds responsible.
PMID- 10782485
TI - Cyclooxygenase active bioflavonoids from Balaton tart cherry and their structure
activity relationships.
AB - Several flavonoids and isoflavonoids isolated from Balaton tart cherry were
assayed for prostaglandin H endoperoxide synthase (PGHS-1) enzyme or
cyclooxygenase isoform-1 (COX-1) activity. Genistein showed the highest COX-1
inhibitory activity among the isoflavonoids studied, with an IC50 value of 80
microM. Kaempferol gave the highest COX-1 inhibitory activity among the
flavonoids tested, with an IC50 value of 180 microM. The structure-activity
relationships of flavonoids and isoflavonoids revealed that hydroxyl groups at
C4', C5 and C7 in isoflavonoids were essential for appreciable COX-1 inhibitory
activity. Also, the C2-C3 double bond in flavonoids is important for COX-1
inhibitory activity. However, a hydroxyl group at the position decreased COX-1
inhibitory activity by flavonoids.
PMID- 10782486
TI - Anti-inflammatory and anti-arthritic activities of silymarin acting through
inhibition of 5-lipoxygenase.
AB - Silymarin, a mixture of flavonolignans, comprised mainly of three isomers,
silybin, silydianin and silychristin isolated from the fruits of Silybum
marianum, is currently in therapeutic use as a hepatoprotective agent. Silymarin
on evaluation exhibited significant antiinflammatory and antiarthritic activities
in the papaya latex induced model of inflammation and mycobacterial adjuvant
induced arthritis in rats. Results of the study indicate its action through
inhibition of 5-lipoxygenase for antiinflammatory and antiarthritic activities.
PMID- 10782487
TI - Isolation and hypoglycemic activity of 5, 7,3'-trihydroxy-3,6,4'
trimethoxyflavone from Brickellia veronicaefolia.
AB - Hypoglycemic activity-guided fractionation together with chemical analysis led to
the isolation of one flavone (5, 7,3'-trihydroxy-3,6,4'-trimethoxyflavone) from
the chloroform extract of the leaves of Brikkellia veronicaefolia. Identification
was based on spectroscopic methods. The isolated flavone was tested for
hypoglycemic activity in normal and alloxan-diabetic CD1 mice (25-30 g) were
administered in doses of 10, 25 and 50 mg/kg body weight. The blood glucose
levels were determined before and 1.5, 3, 4.5 and 24 hours after drug
administration. The results showed that the flavone produces a significant
hypoglycemic effect in normal as well as in diabetic mice. Comparison was made
between the action of the flavone and a known hypoglycemic drug as tolbutamide
(50 mg/kg). The flavone was found to be slow and less effective than tolbutamide.
PMID- 10782488
TI - Antiamoebic and spasmolytic activities of extracts from some antidiarrhoeal
traditional preparations used in Kinshasa, Congo.
AB - Three major extracts from some traditional preparations, based on medicinal
plants, used as antidiarrhoeal agents were investigated for their putative
antiamoebic and spasmolytic activities in vitro. Results indicated that both
biological activities are concentrated in the polyphenolic fraction, and not in
the saponin or alkaloid containing fractions. The most active polyphenolic
extracts were those from Euphorbia hirta whole plant, leaves of Alchornea
cordifolia, Crossopteryx febrifuga, Nauclea latifolia, Psidium guajava, Tithonia
diversifolia, stem bark of Harungana madagascariensis, Mangifera indica,
Maprounea africana and Psidium guajava, inhibiting Entamoeba histolytica growth
with MAC < 10 micrograms/ml. The same extracts, at a concentration of 80
micrograms/ml in an organ bath, also exhibited more than 70% inhibition of
acetylcholine and/or KCl solution-induced contractions on isolated guinea-pig
ileum.
PMID- 10782489
TI - Cytotoxic activity of hydrolyzable tannins against human oral tumor cell lines--a
possible mechanism.
AB - Hydrolyzable tannins showed higher cytotoxic activity against human oral squamous
cell carcinoma and salivary gland tumor cell lines than against normal human
gingival fibroblasts, whereas gallic acid, a component unit of tannins, showed
much weaker selective cytotoxicity. The cytotoxic activity of dimeric compounds
was generally higher than that of monomeric compounds. Macrocyclic ellagitannin
oligomers, such as oenothein B, woodfordin C and woodfordin D showed the greatest
cytotoxic activity, and their activity (per given number of molecules) was one
order higher than those of gallic acid and epigallocatechin gallate, a major
component of green tea. These compounds induced apoptotic cell death
characterized by DNA fragmentation (as demonstrated by the TUNEL method) and
cleavage of cytokeratin 18 by activated caspase(s) (as demonstrated by M30
monoclonal antibody). ESR spectroscopy revealed that these macrocyclic compounds
at higher concentrations produced their own radicals and significantly enhanced
the radical intensity of sodium ascorbate, possibly by their prooxidant actions.
Catalase failed to eliminate their apoptosis-inducing activity, reducing the
possibility of the involvement of hydrogen peroxide production in the
extracellular fraction. These observations suggested that the antitumor activity
of macrocyclic ellagitannin oligomers reported previously might be explained by
their apoptosis-inducing activity.
PMID- 10782490
TI - Effects of luteolin on arylamine N-acetyltransferase activity in rat blood and
liver.
AB - In this study we investigated inhibition of Arylamine N-acetyltransferase (NAT)
activity in rat blood and liver tissue cytosols by luteolin. Using high
performance liquid chromatography, NAT activity for acetylation of 2
aminofluorene and remaining unacetylated 2-aminofluorene were examined. The NAT
activity in rat blood and liver tissue was inhibited by luteolin in a dose
dependent manner: higher concentrations of luteolin in the reaction resulted in
greater inhibition of NAT activities in both examined tissues. The data also
indicated that luteolin decreased apparent Km and Vmax of NAT enzymes from rat
blood and liver tissue cytosols. This report is the first demonstration that
luteolin can affect rat blood and liver tissue NAT activity.
PMID- 10782491
TI - Role of Salviae Miltiorrhizae Radix extract and its compounds in enhancing nitric
oxide expression.
AB - Excessive production of nitric oxide (NO) and its peroxidant product,
peroxynitrite, has been implicated in the pathology of acute and chronic renal
failure, and inhibitors of NO production have been shown to exert protective and
ameliorative effects against renal epithelial cell damage mediated by enhanced
generation of NO. Salviae Miltiorrhizae Radix has exhibited a beneficial effect
in the improvement of renal failure. In order to clarify the mechanism
responsible, we investigated whether Salviae Miltiorrhizae Radix extract and
several of its related compounds, including caffeic acid and its polymers which
were isolated by our research group, can regulate the generation and release of
NO. The results demonstrated that Salviae Miltiorrhizae Radix extract and these
compounds suppressed NO effectively in the systems employing activated
macrophages and the arginine-hydrogen peroxide, and that, furthermore, the
activity shown by the compounds was higher than that shown by the extract. In
addition, direct scavenging of NO was also observed. The present findings suggest
that Salviae Miltiorrhizae Radix extract and its compounds are potent NO
inhibitors, and that their inhibitory effect on the generation and release of NO
may contribute to the previously reported pharmacological effect of Salviae
Miltiorrhizae Radix in improving renal function.
PMID- 10782494
TI - The psychodynamic and pharmacodynamic effects of drugs: a differentiated
evaluation of the efficacy of phytotherapy.
AB - The therapeutic usefulness of medicines is nowadays usually measured in terms of
parameters devised in the artificial surroundings of a double blind clinical
trial. The difference between the active drug and the placebo is accepted as
being the same as the desired overall effect. Yet, when applied to whole
categories of medicines, this yardstick can be misleading, as has become apparent
from the discussion which has recently arisen regarding the genuine and the
illusory pharmacodynamic effects of synthetic antidepressants. Differentiated
analysis of a representative number of placebo-controlled studies has shown that
when used for depressive conditions, the psychodynamic components contribute far
more to the overall effect than do the pharmacodynamic components. In this
respect, modern synthetic antidepressants are no better than Hypericum products
of plant origin. Among other things, this means that for depressive states and
similar indications, the safety, tolerability and acceptability of a medicine
must be given much greater weight than its pharmacodynamic effects as assessed
simply by testing against a placebo. The quantification of the two therapeutic
components, as can be accomplished by a placebo-controlled drug trial, has
revealed that the overall outcome of therapy for various important indications of
this kind is attributable predominantly to the psychodynamic component. It may
reasonably be assumed that the contribution made by the pharmacodynamic effects
to the overall therapeutic response will amount to only about 20-50%. This raises
questions regarding the clinical relevance and economic value of placebo
controlled studies. When assessing data on drug efficacy for the purpose of
licensing applications, greater attention should be given to this reality.
PMID- 10782492
TI - Mechanisms of the contractile effect of the hydroalcoholic extract of Cissampelos
sympodialis Eichl. in the rat aorta.
AB - In the present work the effect of the aqueous fraction of the ethanolic extract
of the leaves (AFL) of Cissampelos sympodialis Eichl. was investigated in the rat
aorta. In the presence of functional endothelium, AFL produced concentration
dependent contractions (EC50 value of 76.6 +/- 17.8 micrograms/ml). In the
absence of functional endothelium, the concentration-response curves to AFL were
significantly shifted to the left (EC50 values of 1.3 +/- 0.9 micrograms/ml)
without modification of its maximal contractile effect. In the presence of L-NAME
(300 microM) and of indomethacin (10 mM), the concentration-response curves
produced by AFL were also shifted to the left (EC50 values of 21.8 +/- 6.2 and
24.3 +/- 13.2 micrograms/ml, respectively). The treatment of the aortas with L
NAME (300 microM) plus indomethacin (10 microM) produced a significant shift to
the left of the concentration-dependent curves of AFL (EC50 value of 4.9 +/- 2.2
micrograms/ml), similar to that observed in the absence of the vascular
endothelium. In addition, AFL-induced contraction was abolished in the presence
of prazosin (1 microM), and significantly shifted to the right in the presence of
yohimbine (EC50 value of 723.6 +/- 76.4 micrograms/ml). Thus, based on these
results, it can be concluded that contractions induced by AFL in the rat aorta
were due to activation of alpha-adrenoceptors. Furthermore, these results also
showed that the AFL-induced contractions were modulated by the endothelium, via
the release of NO and of a cyclooxygenase-derived relaxant product. Finally, it
can be concluded that the contractile effects of AFL on vascular smooth muscle
may play an important role in the hypertensive effects of this plant in vivo.
PMID- 10782493
TI - Effect of shitei-to, a traditional Chinese medicine formulation, on
pentylenetetrazol-induced kindling in mice.
AB - This study measured the effects of Shitei-To (STT), a traditional Chinese
Medicine, which is a mixture of extracts from three medicinal herbs, Shitei (SI,
Kaki Calyx; calyx of Diospyros kaki L. f.), Shokyo (SK, Zingiberis Rhizoma;
rhizome of Zingiber officinale Roscoe) and Choji (CJ, Caryophylli flos; flowerbud
of Syzygium aromaticum [L.] Merrill et. Perry), has long been used for the
treatment of hiccups in Japan and China, against fully pentylenetetrazol-kindled
seizures and on the development of pentylenetetrazol kindling in mice. Repeated
administration of STT (3.0 g/kg p.o.) mildly retards the development of
pentylenetetrazol-induced kindling in mice. STT also decreased the number of
tonic-clonic convulsions resulting from progression kindling. On the other hand,
STT had no effect on convulsions in fully pentylenetetrazol-kindled mice. These
findings suggest that STT protects against the development of convulsions, and
that STT may have therapeutic effects in the prevention of secondarily
generalized seizures.
PMID- 10782495
TI - Functional and structural aspects of the Kell blood group system.
AB - Two covalently linked proteins, Kell and XK, constitute the Kell blood group
system. Kell, a 93-Kd type II glycoprotein, is highly polymorphic and carries all
but 1 of the known Kell antigens, and XK, which traverses the membrane 10 times,
carries a single antigen, the ubiquitous Kx. The Kell/XK complex is not limited
to erythroid tissues and may have multiple physiological roles. Absence of one of
the component proteins, XK, is associated with abnormal red cell morphology and
late-onset forms of nerve and muscle abnormalities, whereas the other protein
component, Kell, is an enzyme whose principal known function is the production of
a potent bioactive peptide, ET-3.
PMID- 10782496
TI - Food and Drug Administration's proposed approach to regulation of hematopoietic
stem/progenitor cell products for therapeutic use.
PMID- 10782497
TI - The cytomegalovirus-"safe" blood product: is leukoreduction equivalent to
antibody screening?
PMID- 10782498
TI - Multicenter randomized controlled trials in transfusion medicine.
PMID- 10782499
TI - Indeterminate results in blood donor testing: what you don't know can hurt you.
PMID- 10782500
TI - Cross-reactivity of antibodies to human and primate red cell antigens.
PMID- 10782502
TI - [Quality assurance in geriatrics--a further challenge!].
PMID- 10782501
TI - The evaluation and management of platelet refractoriness and alloimmunization.
PMID- 10782503
TI - [Quality assurance in geriatric rehabilitation hospital treatment. Long-term
medical and functional outcome].
AB - Clinical geriatric therapy has shown to be beneficial and cost-effective.
However, little is known about its long-term results. Based on GEMIDAS (Geriatric
Minimal Data Set), a multicenter-Database of the German Federal Association of
140 Clinical Geriatric Institutions, we conducted a one-year-follow-up pilot
study focusing on medical and functional results, including needs of technical
aids and nursing. Mortality was 16% at 1 year. Two thirds of the deceased had
died during the first half year, many with severe stroke. Among the 840
survivors, 81.1% lived in their private housing, 14.5% in nursing homes, 4.4%
were actually hospitalized. 37.3% suffered from recurrent diseases such as stroke
(5.2%), bone fractures (4.5%), heart attacks (2.1%), severe infections (1.1%),
needing hospitalization in 31.9%, repeatedly in 6.9% of the survivors. Technical
aids were regularly used in about 80%. Personal help was often necessary and was
provided by relatives (66.9%), professional nursing (39.8%), neighbors (5.7%),
only 6% of the patients needed no help. The initial functional gain (mean Barthel
Index from 53.4 to 72.3 points) diminished to 59.6 points during follow-up, with
similar patterns for most of the single Barthel-items. Our results confirm the
initial benefit and clearly show a significant long-term effect of clinical
geriatric rehabilitation. For stabilization and further functional improvement,
specific and continuous rehabilitation efforts seem to be crucial.
PMID- 10782504
TI - [Documentation and quality assurance in clinical routine].
AB - Quality assurance by documentation in the clinical routine may no longer be
regarded as a tedious additional duty providing only little practical value in
medical care. This leads to users' resistance and to statistics of doubtful
validity. Therefore, the great significance of the primary medical documentation
for the quality assurance has to be emphasized and should be the focus of an
efficient documentation-management. Requirements for such a documentation
management are described and their implementation in the Albertinen-Haus is
shown. This institution uses conventional paper-documents as well as their
electronic counterparts. An efficient documentation-management shows the
advantage of a quality assurance for the daily routine in hospitals. Data
required for the statistical quality assurance should merely be a by-product of
the usual documentation. This can only be achieved by an increased computer
support in the clinical routine, but it also requires programmes which fill the
needs of all the team members.
PMID- 10782505
TI - [Geriatric oncology].
AB - The demographic development will result in a major increase in the number of
elderly cancer patients. Age is the main risk factor for the development of a
malignant disease. The incidence of the main cancer diagnosis increases with
advancing age. Treatment of elderly cancer patients is an exquisite task. On the
one hand, an increased morbidity and mortality may be the result of an
unreflected transfer into the geriatric setting of treatment schedules developed
for younger patients. On the other hand, reduction of dose intensity can result
in decreased survival, life prolongation or insufficient palliation. Elderly
people are a very heterogeneous group. Some are in a very good health status.
Others are impaired, dependent, suffer from a number of comorbidities and have to
take a variety of drugs. Those conditions and not the chronological age influence
tolerance against tumour therapy. For elderly patients maintenance of
independence and quality of life is more important than disease free survival and
prolongation of life.
PMID- 10782506
TI - [External quality management in inpatient geriatric care--the SIESTA instrument].
AB - Continuous quality improvement in long term care facilities requires systematic
cooperation of internal and external quality management. We designed SIESTA to
assist skilled nursing care and management in their effort to measure and develop
the quality of care in their facility in a rational way.
PMID- 10782507
TI - [Patient care evaluation studies--a comprehensive concept for evaluation of
oncologic patient management].
AB - As part of the oncological patient care, tumor documentation has been attributed
growing importance as a means of quality assurance. The extended organ specific
tumor documentation can serve to answer some specific clinical questions. The
rational of the so called Patient Care Evaluation Studies (PCES) carried out by
the Commission on Cancer of the American College of Surgeons in the US will be
shown in this article and the objectives of an initial study being carried out in
the Federal Republic of Germany simultaneously with the US-study will be
demonstrated. PCES are a way to compare actual patient care with idealized
recommendations of Clinical Practice Guidelines. Thus, the application of
Practice Guidelines in the clinical routine as one aspect of evidence based
medicine can be analyzed.
PMID- 10782508
TI - [Primary psychosomatic management in general practice. Results of a German
nationwide demonstration project of quality assurance].
AB - In the frame of a national demonstration program, psychosocial care of patients
with psychological and psychosomatic problems were assessed. General
practitioners (n = 191) from six regions participated in the study. 1341
treatment episodes of patients with predominately psychosocial symptoms were
documented. Anxiety (62%), depression (51%) and marital/family conflicts (44%)
were the most frequent symptoms. Somatic treatment and psychosocial intervention
were offered equally. Patients with psychosocial treatment achieved better
results. Partners and family members were rarely integrated into therapy. The
procedures employed to improve outcome were quality circles, family-orientated
case conferences, consultation services and collaborative groups.
PMID- 10782509
TI - [Practice guideline--acute respiratory tract infections. From recommendations for
therapy of acute respiratory tract infections by the Drug Committee of German
Physicians. Drug Committee of German Physicians].
PMID- 10782510
TI - [Managing risks in clinical routine practice and effect of guidelines].
AB - Four steps of risk management are known at present in the clinical practice. For
all forms guidelines are important--these could be national guidelines or in
house guidelines. All guidelines are respected to perform reliable and steady
quality and to reduce risks.
PMID- 10782511
TI - [Problem-based learning in graduate general practice education: the why and how].
AB - This paper describes the experiences with different concepts of problem oriented
learning in a postgraduate training course in general practice in Hamburg. It is
argued that for postgraduate training of general practitioners a four-step-model
is more adequate than the "classical" seven-step-model.
PMID- 10782512
TI - [The problem of anosmia].
AB - Olfactory problems have deleterious consequences to systemic health, nutritional
status and quality of life. Olfactory disorders are not as rare as generally
assumed. Chemosensory dysfunction is most often secondary to one of only a few
causes: nasal/sinus disease, viral infection, toxic chemical exposure, head
trauma, as well as medication-related and idiopathic conditions. Many olfactory
disorders are secondary to a wide variety of diseases, e.g. Alzheimer's disease.
The patient's history may provide clues to these and other problems (e.g. toxin
exposure, congenital dysosmia). Therapy should not begin until a standardized
test has been established the impairment of the sense of smell. Treatment of the
underlying diseases may restore chemosensory function. The only truly reversible
cause is inflammation, which is confirmed when smell returns after administration
of corticosteroids. Reference is made to the need for adequate psychologic
guidance of patients with chemosensorial problems. If restoration of their sense
of smell is unlikely, patients should be educated to ensure safety in regard to
such dangers as gas leaks, smoke, and spoiled foods.
PMID- 10782513
TI - [Autopsy in peri- and neonatology--an essential step in quality control. Data on
autopsy frequency in Saxony].
AB - In the framework of a general quality assurance compaign the working group for
peri- and neonatology at the General Medical Council of Saxony has investigated
the frequency, conclusiveness and development of autopsies in Saxony between 1992
and 1997/98. There were observable different autopsy rates depending on the
degree of neonate maturity. Thus, the autopsy rate of stillbirths having birth
weights from 500 to 999 g amounted to 79.7%, and that of stillbirths above 1000 g
birth weight to only 59.4%. The abduction rate of neonates dying before day 7 of
life was 65.7%. It is remarkable that the abduction rates declines from 79.1 to
62.9% in all weight classes of premature and full-term neonates from 1992 to
1997. The possible reasons for the decline of autopsies and the problems emerging
for quality assurance are discussed.
PMID- 10782514
TI - [Surgical quality assurance in the largest federal district of Austria-
introduction of a project].
AB - On the basis of permanently rising costs in health care on the one hand and
limited budgets on the other hand as well as the increasing importance of correct
and comprehensive quality assurance, we developed protocols for nine different
surgical tracer-diagnosis. These protocols include the minimum standards of the
medical, nursing and administrative area per day of treatment. After one year of
trial at three surgical departments of different capacity, treatment-spectrum and
equipment, revised protocols will be implemented at all 23 surgical departments
in our federal state if necessary.
PMID- 10782515
TI - Chronic urticaria in childhood.
PMID- 10782516
TI - Role of tachykinins in asthma.
AB - The sensory neuropeptides substance P (SP) and neurokinin A (NKA) are localized
to sensory airway nerves, from which they can be released by a variety of
stimuli, including allergen, ozone, or inflammatory mediators. Sensory nerves
containing these peptides are relatively scarce in human airways, but it is
becoming increasingly evident that inflammatory cells such as eosinophils,
macrophages, lymphocytes, and dendritic cells can produce the tachykinins SP and
NKA. Moreover, immune stimuli can boost the production and secretion of SP and
NKA. SP and NKA have potent effects on bronchomotor tone, airway secretions, and
bronchial circulation (vasodilation and microvascular leakage) and on
inflammatory and immune cells. Following their release, tachykinins are degraded
by neutral endopeptidase (NEP) and angiotensin-converting enzyme. The airway
effects of the tachykinins are largely mediated by tachykinin NK1 and NK2
receptors. Tachykinins contract smooth muscle mainly by interaction with NK2
receptors, while the vascular and proinflammatory effects are mediated by the NK1
receptor. In view of their potent effects on the airways, tachykinins have been
put forward as possible mediators of asthma, and tachykinin receptor antagonists
are a potential new class of antiasthmatic medication.
PMID- 10782517
TI - Position statement: UEMS- Section of Allergology and Clinical Immunology.
European specialist care in allergology and clinical immunology in the new
millennium.
PMID- 10782519
TI - Identification of bovine IgG as a major cross-reactive vertebrate meat allergen.
AB - BACKGROUND: Although beef is a main source of protein in Western diets, very
little has been published on allergic reactions to beef or the main allergens
implicated in these reactions. The aim was to evaluate the IgE antibody response
to beef in suspected meat-allergic subjects and assess cross-reactivity of beef
with other vertebrate meats. METHODS: Fifty-seven sera from suspected meat
allergic subjects were tested by grid blot for specific IgE antibodies to
vertebrate meats (beef, lamb, pork, venison, and chicken), and the patterns of
recognition of meat proteins were assessed by immunoblot studies. RESULTS: A 160
kDa band, identified as bovine IgG, was detected in raw beef in 83% (10/12) of
beef-allergic subjects but in only 24% of the beef-tolerant subjects. IgE
reactivity to a band of similar mol. mass was detected also in lamb and venison,
but rarely in pork or chicken. Complete inhibition of the IgE reactivity to the
bovine IgG was obtained with lamb, venison, and milk. IgE reactivity to this band
also completely disappeared when beef or lamb extracts were separated under
reducing conditions, indicating conformational epitopes. CONCLUSIONS: Bovine IgG
appears to be a major cross-reacting meat allergen that could predict beef
allergy. Further studies with oral IgG challenges should be performed to document
the conclusion that in vitro reactivity correlates with clinical
hypersensitivity. The role of bovine IgG in other bovine products such as milk,
dander, or hair must also be studied, and the hypothesis that it is a cross
reacting allergen with other mammalian products validated.
PMID- 10782518
TI - Evaluation of the allergenicity of tropical pollen and airborne spores in
Singapore.
AB - BACKGROUND: Sensitization to pollen and spores of the Southeast Asian tropical
region is not well documented. This study evaluated the allergenicity of the
tropical airspora in Singapore. METHODS: On the basis of the results of an
aerobiologic survey of the airspora profile of Singapore, crude extracts of 23
main spore (fungal and fern) and pollen types were prepared. A total of 231
patients with asthma and/or allergic rhinitis and 76 healthy controls were
evaluated by skin prick test (SPT). Total and specific IgE levels were also
quantified by the fluorescence allergosorbent test (FAST). RESULTS: All 23
allergenic extracts tested elicited positive SPT responses. Among the patients
with atopic diseases, extracts of oil-palm pollen (Elaeis guineensis) were
observed to have the highest frequency of positive reactions (40%), followed by
extracts of resam-fern spores (Dicranopteris linearis) (34%) and sea-teak pollen
(Podocarpus polystachyus) (33.8%). Fungal spores with the highest SPT responses
were Curvularia spp. (26-32%) and Drechslera-like spores (31%). Positive
responses to these extracts correlated with total serum IgE levels of the
subjects and were significantly associated with the presence of atopic disease.
CONCLUSIONS: We have documented sensitization to tropical pollen and spores in
our population. Its association with atopy suggests that it has a role in
allergic diseases in the tropics.
PMID- 10782520
TI - Airway inflammation in asthma and perennial allergic rhinitis. Relationship with
nonspecific bronchial responsiveness and maximal airway narrowing.
AB - BACKGROUND: Eosinophilic airway inflammation is the hallmark of asthma, but it
has also been reported in other conditions such as allergic rhinitis. We have
tested whether the analysis of cells and chemicals in sputum can distinguish
between patients with mild allergic asthma, those with allergic rhinitis, and
healthy controls. The relationship between inflammation markers in sputum and
nonspecific bronchial hyperresponsiveness to methacholine (BHR) (PD20 and maximal
response plateau [MRP] values) was also evaluated. METHODS: We selected 31 mild
asthmatics and 15 rhinitis patients sensitized to house-dust mite. As a control
group, we studied 10 healthy subjects. Every subject underwent the methacholine
bronchial provocation test (M-BPT) and sputum induction. Blood eosinophils and
serum ECP levels were measured. Sputum cell differentials were assessed, and
eosinophil cationic protein (ECP), tryptase, albumin, and interleukin (IL)-5
levels were measured in the entire sputum supernatant. RESULTS: Blood eosinophils
and serum ECP levels were higher in asthma patients and rhinitis than in healthy
controls, but no difference between asthma patients and rhinitis patients was
found. Asthmatics had higher eosinophil counts and higher ECP and tryptase levels
in sputum than rhinitis patients or control subjects. Sputum albumin levels were
higher in asthmatics than in controls. Rhinitis patients exhibited higher sputum
eosinophils than healthy controls. An association between sputum eosinophil
numbers and MPR values (r= -0.57) was detected, and a trend toward correlation
between sputum ECP levels and PD20 values (r= -0.47) was found in the rhinitis
group, but not in asthmatics. No correlation between blood eosinophilic
inflammation and lung functional indices was found. CONCLUSIONS: Induced sputum
is an accurate method to study bronchial inflammation, allowing one to
distinguish between rhinitis patients and mildly asthmatic patients. The fact
that no relationship was detected between sputum inflammation and BHR suggests
that other factors, such as airway remodeling, may be at least partly responsible
for BHR in asthma.
PMID- 10782521
TI - Glucocorticosteroids rapidly inhibit allergen-induced expression of E-selectin in
vitro in a mucosal model of allergic rhinitis.
AB - BACKGROUND: Transendothelial migration of cells to sites of inflammation is a
hallmark of the allergic reaction. The adhesion cascade involves the initial
expression of the adhesion molecule E-selectin on endothelial cells. The aim of
the study was to determine the efficacy of a 30-min preincubation of the
glucocorticosteroids (GCS) fluticasone, prednisolone, and fluocortin butyl on
allergen- and interleukin (IL)-1beta-induced E-selectin expression in allergic
rhinitis. METHODS: Freshly taken nasal inferior turbinate mucosa of 19 subjects
with allergic rhinitis was cut into small cubes and preincubated for 30 min with
prednisolone (n = 6), fluticasone (n = 5), and fluocortin butyl (n = 3) in
different concentrations, followed by allergen exposure at a concentration of
1000 BU/ml for 1 and 2 h. Additionally, fluticasone-preincubated tissues were
exposed to recombinant human rhIL-1beta (n = 5) at a concentration of 2 pg/ml.
The expression of E-selectin was assessed by immunohistochemistry (APAAP
technique) and computerized image evaluation. RESULTS: In this model, E-selectin
expression was significantly upregulated by allergen and rhIL- 1beta within 1 and
2 h. After 30-min preincubation with prednisolone and fluocortin butyl at drug
concentrations of 10-8 mol/1, we found a significant (> or = 50%) reduction of
the E-selectin expression after 1 and 2 h. Allergen-induced E-selectin expression
was nearly abolished at concentrations of 10-5 (prednisolone) and 10-4 mol/l
(fluocortin butyl). Fluticasone significantly inhibited E-selectin expression by
> or = 50% at concentrations of 10-14 and 10-12 mol/l after 1 and 2 h, and
abolished E-selectin induction at concentrations of 10-12 and 10-10 mol/l,
respectively. Exposure of mucosal cubes to rhIL-lbeta (n = 5) also induced rapid
upregulation of E-selectin expression, an effect which could be only partially
suppressed by fluticasone preincubation at concentrations of 10-l0 mol/l.
CONCLUSIONS: Allergen-induced E-selectin expression is significantly and rapidly
inhibited by GCS preincubation, fluticasone being more potent than prednisolone
and fluocortin butyl. We suggest that this rapid effect is mainly indirect,
possibly by inhibition of allergen-induced cytokine release.
PMID- 10782522
TI - House-dust-mite sublingual-swallow immunotherapy (SLIT) in perennial rhinitis: a
double-blind, placebo-controlled study.
AB - BACKGROUND: The safety and efficacy of sublingual-swallow immunotherapy (SLIT) in
rhinitis caused by house-dust mite were evaluated in a double-blind, placebo
controlled study including 75 patients for 24 months. METHODS: Patients received
either placebo or SLIT with a standardized Dermatophagoides pteronyssinus (D.pt.)
- D. farinae (D.f) 50/50 extract. The mean cumulative dose was 90,000 IR,
equivalent to 2.2 mg of Der p 1 and 1.7 mg of Der f I. Symptom and medication
scores were assessed throughout the study. Exposure to house-dust mite, skin
sensitivity, and serum specific IgE and IgG4 were assessed before starting
treatment and after 12 and 24 months. RESULTS: Seventy-two patients (36 active-36
placebo) were eligible for intent-to-treat analysis. Thirty-six patients dropped
out of the study. The number of patients who dropped out due to lack of efficacy
was eight out of 37 (21.6%) in the active treatment group compared to 15 out of
38 (39.5%) in the placebo group (chi-square=2.81, P=0.09). Total symptom and
medication scores decreased significantly after 12 and 24 months (P<0.05) of
treatment in both groups, but no significant difference was observed between the
active and placebo groups. After 24 months, the number of patients with high
levels of indoor allergenic load decreased significantly in both groups compared
to baseline data (P=0.01). Specific IgE (D.pt. and D.f.) increased significantly
in the active treatment group after 12 and 24 months, while no change was
observed in the placebo group. Specific IgG4 levels were not significantly
modified in either group. Two patients in each group reported mild adverse
effects. No severe adverse effects were reported. CONCLUSIONS: We conclude that
SLIT in rhinitis caused by house-dust mite was safe, but there was a lack of
consistent clinical benefit compared to placebo, probably due to the impact of
the allergen avoidance measures that lowered the allergen burden.
PMID- 10782523
TI - Sensitization and lung function in workers occupationally exposed to natural
thickening products.
AB - BACKGROUND: Three workers engaged in the manufacture of natural thickener
products (Cassia spp., guar, and tamarind flour) were occupationally sensitized
to Cassia spp. Therefore, a cross-sectional study on the prevalence of
sensitization among and respiratory health of the employees of this plant was
conducted. METHODS AND RESULTS: Sixty-two workers (36 with high, 26 with low
exposure) participated in the survey. Skin prick tests and specific IgE tests
with extracts of these components revealed that 11.3% were sensitized to Cassia
spp. and 9.7% to at least one species of storage mites, with a significantly
higher portion of atopic subjects in the sensitized group. Overall, 55% of the
subjects reported work-related symptoms (upper and lower airways, eyes, or skin).
FVC % pred. was significantly lower in highly exposed workers, while RV % pred.
and RV%TLC % pred. were significantly higher in this group. In the multivariate
model, sensitization was not a risk factor for impairment of lung function.
CONCLUSIONS: Dust exposure to flours may not only cause allergic sensitization
but also induce chronic changes in lung function.
PMID- 10782524
TI - Cetirizine inhibits bradykinin-induced cutaneous wheal and flare in atopic and
healthy subjects.
AB - BACKGROUND: Kinins are vasoactive mediators involved in allergic reactions. When
applied on the skin or in the nose, bradykinin (BK) elicits inflammation that is
poorly affected by previous H1-blockade. The aim of this study was to compare the
possible effect of cetirizine (an H1-antagonist) on wheal and flare responses to
BK, histamine, and compound 48/80 in atopic and healthy subjects. METHODS: In a
randomized, double-blind, crossover study, eight atopic and eight healthy
subjects received cetirizine (10 mg/day) or placebo for 3 days before cutaneous
tests. Intradermal tests (IDT) and prick tests (PT) were performed with BK (20
nmol/ml for IDT and 20 micromol/ml for PT), histamine (100 microg/ml IDT and 100
mg/ml PT), and compound 48/80 (100 microg/ml IDT and 100 mg/ml PT) as positive
controls and saline as negative control. The skin responses were monitored by
measurement of wheal and flare areas. RESULTS: BK, histamine, and 48/80 induced
wheal and flare reactions in all placebo-treated subjects. Histamine elicited
larger wheal and flare reactions than BK and 48/80. IDT with BK induced four- to
sixfold larger wheal and flare reaction than PT. No differences in BK-induced
wheal and flare were observed between atopic and healthy subjects. In atopic
subjects, cetirizine induced a significant reduction of flare reactions after the
BK test (80% for IDT, and 94% for PT [P < 0.01]). Moreover, cetirizine reduced
significantly BK-induced wheals by 70% for IDT (P < 0.01) and 65% for PT (P <
0.01). A similar inhibiting effect of cetirizine was also observed in healthy
subjects. CONCLUSIONS: These findings showed that the wheal and flare reactions
induced by BK challenge were markedly inhibited by previous intake of cetirizine.
The mechanism by which this effect is mediated cannot be established at present.
PMID- 10782525
TI - Antigliadin IgE--indicator of wheat allergy in atopic dermatitis.
AB - BACKGROUND: Cereal grains are recognized as the cause of adverse reactions in
some patients exposed to grain or flour by either inhalation or ingestion. Cereal
related diseases, such as celiac disease and baker's asthma, have been well
studied and the causative cereal proteins have been characterized. Although
cereals form an essential part of daily nutrition, the allergenic proteins
causing symptoms on ingestion in atopic dermatitis (AD) have remained obscure. In
this study, we have investigated the allergenic fraction of wheat in AD. METHODS:
Skin prick tests (SPT) with a NaCl wheat suspension and the ethanol-soluble wheat
gliadin were performed on 18 wheat-challenge-positive or -negative children with
AD, six adult AD patients with suspected cereal allergy, and one adult with wheat
dependent exercise-induced urticaria/anaphylaxis. Serum total IgE and specific
IgE-antibody levels to wheat and gluten were measured with the
radioallergosorbent test (RAST) simultaneously. In addition serum samples of all
25 patients were analyzed by IgE immunoblotting with the ethanol-soluble wheat
protein extract. RESULTS: Thirteen of the AD children were wheat-challenge
positive, 11/12 of them appeared to be positive with gliadin SPT, and all had an
elevated gluten RAST value. Those challenge-negative were negative with both
gliadin SPT and gluten RAST. Positive wheat SPT and RAST alone were not
associated with positive challenges. Four of the adult patients responded to a
cereal-free diet, although only two of them appeared to be positive with gliadin
SPT and gluten RAST. A broad and intensive staining of gliadin peptides in IgE
immunoblotting studies was seen in challenge-positive children with positive
gliadin SPT and/ or gluten RAST. Besides staining of peptides in the main gliadin
area of 30-46 kDa, a characteristic finding was the staining of small, <14-kDa
proteins with sera of challenge- and gliadin-SPT-positive patients. CONCLUSIONS:
We found that wheat-allergic AD patients have IgE antibodies against gliadin that
can be detected by both SPT and the sensitive immunoblotting method. This
suggests that gliadin peptides are important allergens, and ingestion of wheat
causes symptoms of AD. A broad and intensive IgE staining was seen of gliadin
peptides against both the previously characterized peptides in the main gliadin
area and small, previously uncharacterized peptides of less than 14 kDa. The
gliadin SPT and gluten RAST are good screening methods. Further characterization
of the IgE-stained gliadin proteins is needed.
PMID- 10782526
TI - Eotaxin in induced sputum of asthmatics: relationship with eosinophils and
eosinophil cationic protein in sputum.
AB - BACKGROUND: Eosinophilic inflammation is a crucial aspect of allergic diseases
such as bronchial asthma. An eosinophil-active chemokine, eotaxin, may play a
role in the pathogenesis of the tissue eosinophilia accompanying asthma. METHODS:
Induced sputa were obtained from 53 patients with atopic asthma and six healthy
subjects, and the concentration of eotaxin in the sputum was measured by ELISA.
We investigated whether the sputum content of eotaxin is related to 1) asthma
status or corticosteroid therapy, and 2) other sputum indices, including
percentage of eosinophils and concentration of eosinophil cationic protein (ECP).
RESULTS: The patients with stable or unstable asthma showed significantly higher
concentrations of sputum eotaxin than the normal controls. The level of sputum
eotaxin demonstrated a positive correlation with the percentage of eosinophils in
stable asthmatics not receiving corticosteroid therapy, but not in stable
patients treated with corticosteroids, or in unstable patients. Sputum eotaxin
demonstrated a positive correlation with ECP in asthmatic patients who were
either in a stable state or not receiving steroid therapy. CONCLUSIONS: The
elevated level of eotaxin detected in association with increased eosinophils and
ECP in the sputum of asthmatics suggests that eotaxin is involved in the
pathogenesis of eosinophilic airway inflammation. The relationship of eotaxin to
airway eosinophilia may be modified by the stability status of asthma and
corticosteroid therapy.
PMID- 10782527
TI - Pocket 4 in the HLA-DRB1 antigen-binding groove: an association with atopy.
AB - BACKGROUND: Many studies have attempted to identify an association between HLA
genes and atopy, given the role of HLA molecules in the regulation of the immune
response. In the case of house-dust mites, it is difficult to find an association
with a particular HLA allele, due to the complexity of the allergen. The
objective was to investigate whether HLA-DRB1 functional groups are better
correlated with the atopic disease in our population than DRB1 alleles. METHODS:
The method was reanalysis of the HLA-DRB1 data of a previous case/ control study.
RESULTS: The "Dr" group was found to be associated with the atopic disease in our
population. CONCLUSIONS: Grouping HLA-DRB1 alleles into functional categories may
assist in the search for predictive factors in relation to atopic disease.
PMID- 10782528
TI - Indoor exposure to formaldehyde and risk of allergy.
PMID- 10782530
TI - Asthma caused by a pet bat.
PMID- 10782529
TI - Allergic rhinitis to turtle food.
PMID- 10782531
TI - Occupational rhinitis/asthma to courgette.
PMID- 10782532
TI - Intrauterine cow's milk sensitization.
PMID- 10782533
TI - Advantage of insulin lispro in suspected insulin allergy.
PMID- 10782534
TI - Allergy to cypress pollen.
PMID- 10782535
TI - Occupational allergy to cyclamen.
PMID- 10782536
TI - Selective hypersensitivity to diclofenac.
PMID- 10782537
TI - Diclofenac-induced fever.
PMID- 10782538
TI - Allergy to gelatin.
PMID- 10782539
TI - Selective immediate hypersensitivity to ceftriaxone.
PMID- 10782541
TI - Asthma to tetramethrin.
PMID- 10782540
TI - Fever and urticaria to codeine.
PMID- 10782542
TI - Immediate hypersensitivity to ceftriaxone.
PMID- 10782543
TI - Do we still need psychiatric case registers?
PMID- 10782544
TI - Combination of antidepressants and psychological treatments for bulimia nervosa:
a systematic review.
AB - This review assessed the effect of a combination of antidepressants plus
psychological approaches compared to each single treatment for bulimia nervosa.
METHOD: Trials were included in two meta-analyses: single antidepressants versus
combination and single psychological approaches versus combination.
Methodological quality and homogeneity of results were assessed. Dichotomous
outcomes were analysed by calculating relative risks (RR). RESULT: Five trials
were included in meta-analysis 1 and 7 in meta-analysis 2. Remission rates were
42% for combination versus 23% for antidepressants (RR = 1.38; 95% CI=0.98-1.93;
P=0.06) and 36% for psychological approaches compared to 49% for combination (RR=
1.21; P=0.03). Drop-out rates were 16% for psychological approaches and 30% for
combination (RR =0.57; 95% CI = 0.38-0.088; P=0.11). CONCLUSION: Efficacy of
combined treatments was superior to single approaches. When antidepressants were
combined to treatment, acceptability of psychological approaches was
significantly reduced.
PMID- 10782545
TI - Cognitive impairment and syndromal depression in estimates of active life
expectancy: the 13-year follow-up of the Baltimore Epidemiologic Catchment Area
sample.
AB - OBJECTIVE: Our hypothesis was that including cognitive status and syndromal
depression in specifying functional impairment would result in significant
differences in estimates of active life expectancy from specifications that
included only standard functional measures (such as activities of daily living).
METHOD: The subjects were the 3481 continuing participants of the Baltimore
Epidemiologic Catchment Area Program. Interviews included criterion-based
diagnosis of depression, assessment of cognitive status and standard survey
questions on function. RESULTS: Estimates of active life expectancy decreased
from 9.8 years to 8.9 years at age 65 years for men, and from 10 years to 8.4
years at age 65 years for women, when the definition of active life expectancy
included measures of cognitive impairment and syndromal depression. CONCLUSION:
Measurements of active life expectancy tend to ignore dependencies related to
psychological causes, and should move beyond mere enumeration of activities of
daily living and instrumental activities of daily living.
PMID- 10782546
TI - Cognitive dysfunctions and white matter lesions in patients with bipolar disorder
in remission.
AB - OBJECTIVE: To compare cognitive functioning in relation to white matter lesions
in bipolar disorder in remission and schizophrenia. METHOD: Cognitive performance
and the occurrence of white matter lesions on MRI images of the brain were
assessed in 22 patients with bipolar disorder in remission, 22 patients with
schizophrenia and 22 healthy volunteers. RESULTS: Performance of tests of memory,
speed and cognitive flexibility was significantly impaired in both patient
groups. The frequency of white matter lesions did not differ significantly
between the three groups. No differences in cognitive performance were found
between patients with white matter lesions and patients without such lesions.
CONCLUSION: White matter lesions apparently do not underlie cognitive deficits
that are found in patients with bipolar disorder in remission and in patients
with schizophrenia.
PMID- 10782547
TI - Cognitive dysfunction in obsessive-compulsive disorder.
AB - OBJECTIVE: Assessment of cognitive functions among obsessive-compulsive disorder
(OCD) patients would help in understanding the neurobiology and brain areas
involved in that disorder. The objective of this work was to study the cognitive
dysfunction in OCD patients and to identify its correlation with both the
clinical picture and the severity of the disorder. METHOD: Neuropsychological and
electrophysiological event-related potentials were tested in 30 OCD patients and
compared with 30 normal volunteers of a matched gender, age and education.
RESULTS: Results showed a defective visuospatial recognition, which worsens with
chronicity, deteriorated set-shifting abilities, overfocused attention to
irrelevant stimuli and delayed selective attention to relevant tasks. Mild cases
showed better selective attention than severe cases. Obsessive cases had a
defective visual memory, while compulsive cases had delayed perception of task
relevant stimuli. Mixed cases showed disturbed information-processing both early
and late. CONCLUSION: OCD patients have a characteristic pattern of cognitive
dysfunction that differs among patients of varied severity, chronicity and
symptom type. We suggest a striatofrontoparietal neural pathophysiology. OCD
seems to be a heterogeneous disorder, both clinically and pathophysiologically.
PMID- 10782548
TI - Sex differences in late-life depression.
AB - OBJECTIVE: The primary aim of this study was to assess sex differences in
depression in later life. METHOD: In a random, age and sex-stratified community
sample of 3056 older Dutch people (55 85 years) the prevalence, symptom-reporting
and risk factors associated with depression in later life were studied.
Depression was measured with the Center for Epidemiologic Studies Depression
scale (CES-D). Bivariate, multivariate and factor analyses were used. RESULTS:
Prevalence of depression in women was almost twice as high as in men. Controlling
for age and competing risk factors reduced the relative risk for females with
more than half. Symptom-patterns in men and women were very much alike. Sex
differences in associations with risk factors were small, but exposure to these
risk factors was considerably higher in females. CONCLUSION: Very little evidence
for a typical 'female depression' was found. Female preponderance in depression
was related to a greater exposure to risk factors.
PMID- 10782549
TI - Regional differences in schizophrenia incidence in Denmark.
AB - OBJECTIVE: To examine the regional distribution of schizophrenia incidence in
Denmark. METHOD: A cohort consisting of 2441 Danish psychiatric patients, with
first-time admissions between January 1, 1978 and December 31, 1982, and
diagnosed as having schizophrenia (ICD-8) at least once in a 10-year period of
observation was divided into three regional groups by degree of urbanization.
RESULTS: Incidence increased for both sexes with increasing urbanization. A
diagnostic delay was most pronounced in the least urbanized areas and was most
pronounced for women. CONCLUSION: Our study confirms the existence of regional
differences in schizophrenia incidence on a national basis. Marked regional
differences in diagnostic delay were also demonstrated. A possible explanation
could be regional differences in diagnostic procedures, underlining the
importance of uniform diagnostic patterns as a means for reliable mapping of
psychiatric morbidity and, hopefully, adequate treatment.
PMID- 10782550
TI - Changes in negative symptoms and the risk of tardive dyskinesia: a longitudinal
study. UK700 Group.
AB - OBJECTIVE: To examine whether the development of tardive dyskinesia (TD) is
accompanied by a parallel process of worsening negative symptoms in a
longitudinal study. METHOD: A sample of 708 psychotic patients were followed over
a period of 2 years, using the Abnormal Involuntary Movement Scale and the Scale
for the Assessment of Negative Symptoms (SANS). RESULTS: Of 361 individuals with
no prior evidence of dyskinesia, 46 (13%) developed TD by year 2. Independent of
the effects of male sex (odds ratio (OR)=2.18, 95% confidence interval: 1.00
4.74), age (OR per quartile group = 1.39, 95% CI: 1.01-1.90), duration of
exposure to antipsychotic medication (OR = 2.35 per 8 months, 95% CI: 1.17-4.72)
and average SANS score (OR per quartile group = 1.38, 95% CI: 0.99-1.93),
worsening of negative symptoms over the 2 previous years was associated with TD
onset (OR per quartile group = 1.46, 95% CI: 1.07-2.00). CONCLUSION: The
development of TD is linked, independent of the effect of antipsychotics and
older age, to an illness-related pathological process, characterized by worsening
negative symptoms.
PMID- 10782551
TI - Quantitative EEG in 'positive' and 'negative' schizophrenia.
AB - OBJECTIVE: Quantitative EEG has yielded different results in schizophrenia. The
method of quantitative EEG has been relatively poorly used in the studies of the
dichotomy into positive and negative schizophrenia. METHOD: Amplitude values of
any particular frequency band (after fast Fourier transformation, FFT) were
observed in 47 schizophrenic patients (25 patients with positive and 22 patients
with negative schizophrenia) and in 50 normal subjects. The frontal, temporal,
parietal and occipital regions (F3, F4, C3, C4, T3, T4, P3, P4, O1 and O2) were
observed. RESULTS: Positive and negative schizophrenia were found to differ only
in the delta and theta bands over frontal regions. Positive and negative
schizophrenic patients were found to differ from normal subjects in delta, theta,
alpha and beta 2 bands. CONCLUSION: Delta and theta activity may play a role as a
marker in differentiating between positive and negative schizophrenia.
PMID- 10782552
TI - Heterogeneity in schizophrenia; mixture modelling of age-at-first-admission,
gender and diagnosis.
AB - OBJECTIVE: Identifying and explaining sources of heterogeneity in schizophrenia
would help elucidate its aetiology and course. In this paper we examine
heterogeneity in terms of age-at-first-admission, diagnosis and gender by
decomposing a large dataset using mixture modelling. METHOD: Using the Queensland
Mental Health Statistics System, we first extracted age-at-first-admission data
for schizophrenia (ICD8/9 295) to represent a 'narrow' definition of
schizophrenia (N= 7651); we then added paraphrenia (297) and other non-organic
psychoses (298) for a 'broad' definition (N= 10 199). Mixture models were fitted
to these narrowly and broadly defined distributions for both males and females.
RESULTS: For narrowly defined schizophrenia a three-component model best fitted
both male and female distributions. While the mean ages of these components were
very similar for both males and females, the ratios of males to females crossed
from an excess of males in the 'youngest' component to an excess of females in
the 'oldest' component. When using the broad definition, four components best
fitted the underlying distributions. While the first three were similar to those
found for narrowly defined schizophrenia, the additional fourth component
reverted to a male excess; however, the mean age for males was 10 years younger
than for females. CONCLUSION: Our findings suggest that subtypes based on age-at
first-admission can be identified, although the number identified depends on how
inclusively schizophrenia is defined. While there appear to be the same number
with similar mean ages for both genders, there are differences in the proportions
of males to females. Further work to fully characterize their nature is
warranted.
PMID- 10782553
TI - Effects of a coping-orientated group therapy for schizophrenia and
schizoaffective patients: a pilot study.
AB - OBJECTIVE: This controlled pilot study was designed, first, to examine the
efficacy of two different group therapy formats for schizophrenia and
schizoaffective patients: a patient-centred, psychoeducative and coping
orientated group therapy approach and a supportive therapy group. Secondly, it
intended to establish preliminary hypotheses on the therapeutically relevant
factors. METHOD: In a sample of 32 patients suffering from schizophrenia or a
schizoaffective disorder the effect sizes of the coping-orientated therapy
approach and a supportive group therapy on several outcome variables were
examined and the predictive power of different effect variables on outcome was
analysed. RESULTS: The effect sizes show improvements in the cognizance of the
disorder and the related pharmacotherapy, the psychopathology and the social
functioning for both therapy conditions. Moreover, outcome as measured after 1
year was best predicted by the patient's mastery of active, problem-focused
coping strategies. CONCLUSION: The results corroborate the appropriateness of
focusing on aspects of coping-behaviour in psychological interventions.
PMID- 10782555
TI - Patient satisfaction: a valid index of quality of care in a psychiatric service.
AB - OBJECTIVE: To assess patients', clinicians' and referrers' satisfaction with care
in newly referred psychiatric patients and to compare these with standard quality
indicators such as waiting times used by the service. METHOD: A random sample of
all new adult psychiatric patients presenting over a 4-month period in 2
successive years to an inner-city psychiatric service was assessed. RESULTS: One
hundred and thirteen (68%) of 167 randomly selected patients were seen.
Independent evidence of service performance showed that patient satisfaction, but
not clinician or referrer satisfaction, was a more accurate indicator of quality
of care than standard indicators. CONCLUSION: Simple ratings of patient
satisfaction alone may be useful indicators of quality of psychiatric care.
PMID- 10782554
TI - Development, reliability and acceptability of a new version of the DSM-IV Social
and Occupational Functioning Assessment Scale (SOFAS) to assess routine social
functioning.
AB - OBJECTIVE: Development of a scale to assess patients' social functioning, the
Personal and Social Performance scale (PSP). METHOD: PSP has been developed
through focus groups and reliability studies on the basis of the social
functioning component of the DSM-IV Social and Occupational Functioning
Assessment Scale (SOFAS). The last reliability study was carried out by 39
workers with different professional roles on a sample of 61 psychiatric patients
admitted to the rehabilitation unit. Each patient was rated independently on the
scale by the two workers who knew them best. RESULTS: The PSP is a 100-point
single-item rating scale, subdivided into 10 equal intervals. The ratings are
based mainly on the assessment of patient's functioning in four main areas: 1)
socially useful activities; 2) personal and social relationships; 3) self-care;
and 4) disturbing and aggressive behaviours. Operational criteria to rate the
levels of disabilities have been defined for the above-mentioned areas. Excellent
inter-rater reliability was also obtained in less educated workers. CONCLUSION:
Compared to SOFAS, PSP has better face validity and psychometric properties. It
was found to be an acceptable, quick and valid measure of patients' personal and
social functioning.
PMID- 10782556
TI - Clozapine and risperidone: combination/augmentation treatment of refractory
schizophrenia: a preliminary observation.
AB - OBJECTIVE: Clozapine and risperidone were the first two antipsychotic drugs of a
new class of agents for the pharmacotherapy of schizophrenia. It has been
suggested that refractory schizophrenic patients who fail to respond to neither
clozapine nor risperidone may respond to a combination/augmentation strategy of
both medicaments. METHOD: Three cases of individuals with unremittent
schizophrenia treated via this combination are presented. Response was evaluated
by clinical follow-up and PANSS rating scale. RESULTS: Good clinical results with
no noticeable adverse side effects, ascertained by a reduction from baseline
scores of the Positive and Negative Syndrome Scale (PANSS) were obtained in all
three patients. CONCLUSION: The findings from this pilot study suggest this
combination as a possible therapeutic approach for treating resistant
schizophrenic patients.
PMID- 10782557
TI - Progressive brain atrophy and VBR increase in schizophrenia?
PMID- 10782558
TI - Interactive educational diabetes simulators: future possibilities.
AB - In 1996 an interactive educational diabetes simulator called AIDA was released
without charge on the Internet as a non-commercial contribution to continuing
diabetes education. Over the past 3 years over 30,000 people have visited the
AIDA Web site-- http://www.diabetic.org.uk/aida.htm--and over 10,000 copies of
the program have been downloaded from there free-of-charge. This review builds on
the experience gained from the AIDA development and the World Wide Web
distribution of the software, and looks to the future, highlighting features
which users might expect to see in future generations of such interactive
educational diabetes programs. Novel functions already described in the
literature are overviewed, and possible applications using personal computers and
the Internet are discussed. The importance of the user interface is stressed. The
concept of a "virtual diabetic patient" that provides an electronic
representation of a patient with diabetes--and which can be used for self
learning/teaching/demonstration purposes--is highlighted.
PMID- 10782559
TI - Dexamethasone-induced changes in FAD-glycerophosphate dehydrogenase mRNA, content
and activity, and insulin release in human pancreatic islets.
AB - Human pancreatic islets were cultured for 63 hr at 2.8 or 16.7 mM D-glucose in
the absence or presence of dexamethasone. In the 1.0 to 10 microM range,
dexamethasone caused a concentration-related decrease in the FAD (flavin adenine
dinucleotide)-linked mitochondrial glycerophosphate dehydrogenase (mGDH) mRNA
content of the islets, and decreased both the mGDH content of the islets and the
catalytic activity of the enzyme in islet homogenates, these effects being often
more marked in islets cultured at 16.7 mM, rather than 2.8 mM, D-glucose. Even
after culture in the presence of no more than 10 nM dexamethasone, namely under
conditions in which the mGDH mRNA content and activity were both virtually
unaffected, the corticosteroid restored the capacity of the beta-cells to display
an increase in insulin output in response to a rise in D-glucose concentration in
islets first cultured at 2.8 mM D-glucose but suppressed the insulinotropic
action of the hexose in islets first cultured at 16.7 mM D-glucose. Whilst
revealing an untoward effect of high concentrations of dexamethasone upon mGDH
mRNA, content and activity in human islets, these findings also document a dual
effect of a low concentration of the corticosteroid (10 nM) upon the secretory
responsiveness of human islets to D-glucose, independently of any significant
change in mGDH gene expression. It is proposed that such a dual action may
account, in part at least, for both the well known increase in insulin output
found in hypercorticism and the more recently discovered unfavourable direct
effect of corticosteroid hormones on the secretory activity of islet beta-cells.
PMID- 10782560
TI - A study on lymphocyte subpopulation in diabetic mothers at delivery and in their
newborn.
AB - Despite the importance of immunological aspects in pregnancy, until now few
studies have been reported on the cellular immune modifications of diabetic
pregnancy and on the newborn of diabetic mothers. Therefore, we thought it of
interest to evaluate cell immunity in diabetic pregnant women and in their
newborn children. Fourteen pregnant women with Type 1 diabetes (T1DM), mean age
(+/-SD) 30-4 yr, mean disease duration (+/-SD) 12+/-5 yr, 15 with gestational
diabetes mellitus (GDM) (mean age 33+/-6 yr), and 21 healthy pregnant women (mean
age 29+/-4 yr) were studied and their metabolic and immunological parameters were
evaluated. Fifty newborn babies were examined for immunological evaluation. Mean
fasting plasma glucose and HbA1c values were higher in T1DM and GDM patients than
in controls. Total lymphocyte subsets were higher in T1DM and GDM patients,
although there were no significant differences between the percentual values. In
children of T1DM and GDM mothers absolute lymphocyte values were increased,
whereas the natural killer (NK) subset had decreased values in both absolute and
percentual terms. Our work shows that, with respect to healthy controls, both GDM
and T1DM mothers have a significant increase in total lymphocytes, and newborns
have a reduced number of NK lymphocytes. Lower numbers of NK lymphocytes are
probably related to altered production of lymphokines during foetal life and may
also represent a real immune deficit in monitoring against viral infections.
PMID- 10782561
TI - A strong inverse relationship between PAI-1 and Lp(a) in hypertensive Type 2
diabetic patients.
AB - Thrombophilia with a contemporary reduction of fibrinolytic activity has been
observed both in diabetes mellitus and hypertension. Previously, we found a
relationship between plasminogen activator inhibitor Type 1 (PAI-1) and
lipoprotein(a) [Lp(a)] in Type 2 diabetes mellitus patients without
complications. We hypothesised that this relationship could be due to a
compensatory mechanism able to lower the risk of hypofibrinolysis as found in
Type 2 diabetes mellitus. The present work was aimed at investigating the
influence of concurrent hypertension and diabetes mellitus on the plasma levels
of these two fibrinolytic inhibitors. In addition, other risk factors, known to
influence the fibrinolytic parameters, were taken into account. Forty-nine Type 2
nonhypertensive diabetic patients without complications, 47 Type 2 hypertensive
diabetic patients without complications, 54 non-diabetic hypertensive subjects
without complications as well as 87 control subjects were studied. Plasma
concentrations of Lp(a), PAI-1 antigen and activity, and the main parameters of
oxidative, lipo- and glycometabolic balance were determined. Significant
statistical differences between diabetic and non-diabetic subjects were found
concerning triglycerides and antioxidant defence (p<0.01). Analysis of variance
showed the F test statistically significant in evaluating the Log PAI-1/Lp(a) (p
= 0.02). Correlation analysis between Log PAI-1 antigen and Lp(a) was significant
in non-hypertensive diabetic patients, as expected (r = -0.38, p<0.01), and even
stronger in hypertensive diabetic patients (r = -O.72,p<0.01). These results
allow to hypothesise that the relationship between PAI-1/Lp(a) could be
determinant in avoiding vascular complications due to diabetes mellitus and
hypertension.
PMID- 10782562
TI - Atorvastatin for the management of Type 2 diabetic patients with dyslipidaemia. A
mid-term (9 months) treatment experience.
AB - Dyslipidaemia, particularly increased triglycerides (TG) and low HDL-cholesterol
(HDL-C), represents an important risk factor for Type 2 diabetes (T2DM)
macrovascular complications. Our aim was to evaluate the effects of atorvastatin
in a population of T2DM patients according to their cardiovascular risk: evidence
of myocardial or coronary lesions (group A); evidence of familiar
hypercholesterolaemia (group B); evidence of stable cardiovascular risk (group
C). The mean age was 64+/-7 yr, mean disease duration 9.5+/-3 yr, the mean body
mass index (BMI) 27.7+/-1.3 kg/m2, mean HbA1c 8+/-0.6%; total cholesterol 256+/
24 mg/dl in group A, 298+/-30 and 244+/-31 in groups B and C, respectively
(p<0.05 B vs. A and C). Moreover, mean HDL-C values were about 45+/-7 mg/dl, TG
225+/-20 mg/dl, systolic and diastolic blood pressure 144+/-7 mm Hg and 84+/-8 mm
Hg, respectively; fibrinogen values 330+/-23 mg/dl and microalbuminuria 58+/-9
mg/l. Lipid profile improved significantly during the treatment with personalised
doses of atorvastatin (generally 10 mg/day) designed to achieve the therapeutic
goals: the reduction of total cholesterol, TG (p<0.01), LDL-cholesterol (LDL-C)
(p<0.01) and an increase of HDL-C were measured. The treatment with atorvastatin
induced significant reduction of microalbuminuria and fibrinogen levels (p<0.01).
Moreover, in the subgroup of patients with hypertension, diastolic blood pressure
values were reduced without modification of antihypertensive treatment. This
preliminary study suggests that the management of hypercholesterolaemia with
atorvastatin in T2DM patients may be useful both for the primary and secondary
prevention of chronic complications of T2DM.
PMID- 10782563
TI - Changes of autoantibodies against oxidatively modified low density lipoproteins
during long-term LDL-apheresis.
AB - The oxidation of low-density lipoproteins (LDL) is considered a key event in the
initiation of atherosclerosis. The aim of this study was to follow-up the
biological marker of in vivo LDL oxidation (oxidatively modified LDL autoantibody
titres) during long-term LDL-apheresis treatment. A patient suffering from severe
combined hyperlipidaemia underwent LDL-apheresis biweekly and was followed for
two years. The significant reduction of baseline total cholesterol (58%), total
triglycerides (80%), LDL-cholesterol (48%), apoprotein B (50%) and apolipoprotein
(a) (61%) may be considered as a good response to the treatment. The titre of
autoantibodies (IgG) against oxidatively modified LDL (malondialdehyde-derived
LDL) was followed throughout the study and showed dynamic changes. The measured
values were multiple compared as mean+/-SD over each semester of apheresis
application: I semester 70.0+/-8.3 U/ml, n = 12; II semester 58.0+/-13.8 U/ml, n
= 12; III semester 37.6+/-6.0 U/ml, n=12; IV semester 34.3+/-7.0 U/ml, n = 12;
ANOVA: I vs. II semester p<0.083, II vs. III semester p<0.00053, III vs. IV
semester p<0.248. In parallel to the changes in this biochemical parameter,
regression of numerous xanthomas was clinically observed. In spite of this, the
presence of oxidised-LDL (oxLDL) antibodies was enhanced in comparison to
antibody titre detected in a group of age-matched normolipaemic healthy controls
(n = 15; 19.4+/-8.6; p<0.01). Classical lipoprotein parameters were correlated
with the titre of autoantibodies against oxLDL and showed low correlation
coefficients: total cholesterol vs. oxLDLab, r = 0.36; triglycerides vs. oxLDLab,
r = 0.43; LDL cholesterol vs. oxLDLab, r = 0.14; HDL cholesterol vs. oxLDLab, r =
-0.33; apo B vs. oxLDLab, r = 0.25; apo (a) vs. oxLDLab, r = -0.05. Our study
showed an additional benefit of LDL-apheresis therapy. The production of
autoantibodies against oxLDL was reduced during the treatment, indicating a lower
level of the atherogenic antigen.
PMID- 10782564
TI - Florid diabetic retinopathy and its systemic implications.
PMID- 10782565
TI - Insulin regulation of protein metabolism in vivo.
PMID- 10782567
TI - Optimum protein intake in chronic renal failure.
PMID- 10782566
TI - Protein metabolism in Type 1 and Type 2 diabetes mellitus in the fasted and fed
states.
PMID- 10782568
TI - Is it possible to correct protein metabolism in cirrhotic patients?
PMID- 10782569
TI - Male infertility and environmental exposure to lead and cadmium.
AB - Humans are exposed occupationally and environmentally to metal aerosols including
lead (Pb2+) and cadmium (Cd2+). These toxicants accumulate in male reproductive
organs. Epidemiological studies have been equivocal about effects of Pb2+ and
Cd2+ on hormone concentrations, male fertility and sperm parameters. Comparison
of Pb2+ and Cd2+ concentrations in fertile and infertile men are problematic.
Problem areas include failure to control confounding variables, but genetic
polymorphisms as in somatic diseases may modulate Pb2+ and Cd2+ damage. Multiple
calcium (Ca2+) and potassium (K+) channel isoforms have been identified in human
testes and spermatozoa. These Ca2+ and K+ channels are involved in early events
of acrosome reactions. Ca2+ channel are susceptible to Cd2+ poisoning and K+
channels to Pb2+. These channels offer entry paths for metallic toxicants into
mature spermatozoa. Ion channel polymorphisms may cause differential
sensitivities to Cd2+ and Pb2+, explaining in part prospective blinded studies
showing high Cd2+ in varicocele-related human infertility and high Pb2+ in
unexplained infertility. In both forms of male infertility the ability to undergo
an acrosome reaction decreases. Reverse transcriptase-polymerase chain reaction
assays for Ca2+ and K+ channel isoforms may identify susceptibility subgroups
with lower resistance to environmental exposures.
PMID- 10782570
TI - Smoking and reproduction: gene damage to human gametes and embryos.
AB - Assisted conception is a useful methodology for detecting disturbances in
clinical outcome, meiotic maturation, and genetic integrity of human gametes.
Germinal cells are vulnerable to genetic damage from smoking, but can repair
damage during meiosis. In ejaculated spermatozoa, repair capacity declines
drastically. Smoking alters the meiotic spindle of oocytes and spermatozoa,
leading to chromosome errors which affect reproductive outcomes. Smoking is
associated with reduced numbers of retrieved oocytes, leading to early age of
menopause. Oocyte elimination occurs preferentially during meiosis I, a period
sensitive to genetic damage. Smoking inhibits embryo fragmentation; inhibition
may confer survival advantage to embryos genetically altered. Smoking is
associated with low sperm quality, but clinical effects are not recognized.
Cadmium (a heavy metal), nicotine (a toxic alkaloid), and its metabolite
cotinine, are detectable in gonadal tissues and fluids in association with
smoking. Cotinine incorporates into ovarian granulosa-lutein cells, compromising
the developmental potential of follicles. Benzo[a]pyrene is a carcinogenic
polycyclic aromatic hydrocarbon resulting from cigarette combustion. Its reactive
metabolite binds covalently to DNA, forming adducts. Smoking-related adducts were
detectable in ovarian granulosa-lutein cells, oocytes, spermatozoa and
preimplantation embryos. Transmission of altered DNA from smoking by spermatozoa
was demonstrated in preimplantation embryos and in association with increased
risk of childhood cancer.
PMID- 10782571
TI - Physiological and pharmacological aspects of local transfer of substances in the
ovarian adnexa in women.
AB - An intimate arrangement between the utero-ovarian vein and the ovarian artery has
been found in many species. The anatomical structure suggests the existence of a
counter-current system of exchange, and many animal experiments point to a
physiological importance of this transfer system. In man, the utero-ovarian vein
forms a plexus around the ovarian artery. In-vitro experiments have demonstrated
a local transfer of progesterone; in-vivo experiments have proved that krypton
and progesterone can be transferred from the utero-ovarian vein to the ovarian
artery. The physiological and pharmacological importance of the counter-current
system is still under evaluation, and further investigations are needed. It has
been suggested that counter-current transfer facilitates local communication
between the ovary, Fallopian tube, and uterus. This may be important in a context
of luteolysis, follicular selection and maturation, fertilization, and the
recognition and maintenance of pregnancy. The pharmacological and therapeutic
potential may be limited, as the ovarian adnexa are relatively difficult to
access. Instillation of hormones into the uterine lumen will probably induce a
higher plasma concentration in the ovarian arterial blood than in peripheral
arterial plasma. A culdoscopic or endoscopic approach might permit introduction
of long-acting depots in the uterine fundus near the Fallopian tubes and/or
ovaries.
PMID- 10782572
TI - Comparison between different routes of progesterone administration as luteal
phase support in infertility treatments.
AB - Different routes of natural progesterone supplementation have been tried as
luteal phase support in infertility treatments. Orally administered progesterone
is rapidly metabolized in the gastrointestinal tract and its use has proved to be
inferior to i.m. and vaginal routes. Progesterone i.m. achieves serum
progesterone values that are within the range of luteal phase and results in
sufficient secretory transformation of the endometrium and satisfactory pregnancy
rates. The comparison between i.m. and vaginal progesterone has led to
controversial results as regards the superiority of one or the other in inducing
secretory endometrial transformation. However, there is increasing evidence in
the literature to favour the use of vaginal progesterone. Vaginally administered
progesterone achieves adequate endometrial secretory transformation but its
pharmacokinetic properties are greatly dependent on the formulation used. After
vaginal progesterone application, discrepancies have been detected between serum
progesterone values and histological endometrial features. Vaginally administered
progesterone results in adequate secretory endometrial transformation, despite
serum progesterone values lower than those observed after i.m. administration,
even if they are lower than those observed during the luteal phase of the natural
cycle. This discrepancy is indicative of the first uterine pass effect and
therefore of a better bioavailability of progesterone in the uterus, with minimal
systematic undesirable effects.
PMID- 10782573
TI - The role of heat shock proteins in reproduction.
AB - Heat shock proteins (HSP) were first identified in cells after exposure to
elevated temperature. Subsequently HSP have been identified as a critical
component of a very complex and highly conserved cellular defence mechanism to
preserve cell survival under adverse environmental conditions. HSP are
preferentially expressed in response to an array of insults, including
hyperthermia, free oxygen radicals, heavy metals, ethanol, amino acid analogues,
inflammation and infection. HSP interact with intracellular polypeptides and
prevent their denaturation or incorrect assembly. In addition HSP are also
involved in several processes essential for cellular function under physiological
conditions. HSP production is enhanced during in-vitro embryo culture and they
are among the first proteins produced during mammalian embryo growth. The
spontaneous expression of HSP as an essential part of embryo development is well
documented and the presence or absence of HSP influences various aspects of
reproduction in many species. Finally, HSP are immunodominant antigens of
numerous microbial pathogens, e.g. Chlamydia trachomatis, which have been
recognized as the main cause of tubal infertility. Many couples with fertility
problems have had a previous genital tract infection, have become sensitized to
microbial HSP, and a prolonged and asymptomatic infection may trigger immunity to
microbial HSP epitopes that are also expressed in man. Antibodies to both
bacterial and human HSP are present at high titres in sera and hydrosalpinx fluid
of many patients undergoing in-vitro fertilization (IVF). In a mouse in-vitro
embryo culture model, these antibodies impaired the mouse embryo development at
unique developmental stages. Recent studies indicate an association between a
previous infection, immunity to HSP and reproductive failure.
PMID- 10782574
TI - Sperm function assays and their predictive value for fertilization outcome in IVF
therapy: a meta-analysis.
AB - The prevalence of male infertility and the availability of new, highly successful
therapeutic options make the testing of sperm functional competence mandatory. An
objective, outcome-based examination of the validity of the currently available
assays was performed based upon the results obtained from 2906 subjects evaluated
in 34 prospectively designed, controlled studies. The aim was carried out through
a meta-analytical approach that examined the predictive value of four categories
of sperm functional assays: computer-aided sperm motion analysis (CASA); induced
acrosome reaction testing; sperm penetration assay (SPA); and sperm-zona
pellucida binding assays for IVF outcome. Results demonstrated a high predictive
power of the sperm-zona pellucida binding and the induced-acrosome reaction
assays for fertilization outcome. On the other hand, the findings indicated a
poor clinical value of the SPA as predictor of fertilization and a real need for
standardization and further investigation of the potential clinical utility of
CASA systems. This analysis points out to limitations of the current tests and
the need for standardization of methodologies and provides objective evidence on
which clinical management and future research can be based.
PMID- 10782575
TI - The metabolic effect of antenatal corticosteroid therapy.
AB - The use of antenatal dexamethasone to mature the fetal lung in pregnancies likely
to deliver before 34 weeks is almost universal. It reduces the incidence of
respiratory distress syndrome in the newborn and results in an overall
improvement in neonatal morbidity and mortality. Although considered to be
generally safe, there are concerns about adverse maternal and fetal effects. In a
series of studies, we have found that antenatal dexamethasone administration is
associated with reduced placental hormone production and maternal bone formation,
impaired glucose tolerance and altered function of the hypothalamic-pituitary
adrenal axis. In this article, we have compared our data with other reports in
the human and reviewed the relevant animal data. We conclude that further studies
on the long-term effects of antenatal dexamethasone therapy in the human are
warranted with particular emphasis on the long-term effects on the fetus.
PMID- 10782576
TI - Haemodynamic evaluation of the first trimester fetus with special emphasis on
venous return.
AB - Knowledge of the fetal circulation is a prerequisite for understanding the
physiological behaviour of the developing fetus. In this overview dealing with
Colour and Power Doppler ultrasound findings in the first trimester of pregnancy
and its pathophysiological background, we aim to report on the methodological
aspects, normal blood flow waveform patterns, normal reference values for
haemodynamic parameters and potential clinical applications for both arterial and
venous flow information (umbilical artery, descending aorta, middle cerebral
artery, umbilical vein, inferior vena cava, ductus venosus) and atrioventricular
valves. Particular emphasis is devoted to the venous return to the heart.
Alterations in venous waveforms, particularly in the ductus venosus, are
correlated with the pathophysiology of some fetal diseases and are suggested as a
promising tool for the screening of cardiac impairment and as an alternative
method for fetal biophysical surveillance.
PMID- 10782577
TI - Cost-effective infertility care.
AB - Cost-effective healthcare has become a principal paradigm in all areas of
medicine. In order to establish cost-effective care, clinical outcomes under
various cost conditions have to be examined. Such a process cannot be static
since it has to consider ever evolving treatments and outcome results. In
infertility, the evaluation of cost-effective care should be simpler than in most
other areas of medicine since treatment end-points are easily defined.
Nevertheless, the field is lagging in the establishment of cost-effective
treatment algorithms. In this review, an effort is made to define the current
state of the art of cost effective infertility care, to suggest steps that can be
taken to drive the process forward and to encourage the introduction of even
limited processes to further the concept of outcome-dependent cost assessment
within a practice setting. The limited availability of resources mandates their
judicious use throughout medicine. In a field like infertility, by many (rightly
or wrongly) perceived as 'elective', the judicious use of resources seems even
more necessary since it would permit the treatment of larger patient populations
than have currently access to care without further expense to third-party
payments.
PMID- 10782578
TI - Leukotrienes in gynaecology: the hypothetical value of anti-leukotriene therapy
in dysmenorrhoea and endometriosis.
AB - The lipoxygenase products (leukotrienes) have been demonstrated in many mammalian
tissues including humans. They are widely distributed in the lungs, gut, uterus,
kidneys, skin, heart and the liver. Their roles as mediators of inflammation have
made them therapeutic targets. Significant amounts of leukotrienes have been
demonstrated in the endometrium of women with primary dysmenorrhoea who do not
respond to treatment with anti-prostaglandins. Also, in endometriosis, cytokines,
which can initiate the cascade for the biosynthesis of leukotrienes, have been
shown to be elevated. It is estimated that 10-30% of patients with painful
periods fail to respond to prostaglandin (PG) synthetase inhibitors. Of adult
females approximately 40% have painful menstruation and 10% of these are
incapacitated for 1-3 days per month, and approximately 10% of women aged between
15-45 years suffer from endometriosis, which is a significant cause of
infertility. Leukotriene receptor antagonists have recently been licensed for the
treatment of asthma in the UK. In this review, we present the case for the
potential use of these products in the management of primary dysmenorrhoea
(especially in patients who are not responding to the traditional treatment using
PG synthetase inhibitors) and possibly also in cases of endometriosis.
PMID- 10782579
TI - Survival of Acinetobacter on three clinically related inanimate surfaces.
PMID- 10782580
TI - Creutzfeldt-Jakob disease: management of accidental contamination of
neurosurgical instruments, pathology equipment, and solutions.
PMID- 10782581
TI - Disinfection of hospital laundry using ozone: microbiological evaluation.
PMID- 10782582
TI - Impact of nosocomial infections on outcome: myths and evidence.
PMID- 10782583
TI - Reasons that healthcare workers decline influenza vaccination in a New Zealand
hospital environment.
PMID- 10782584
TI - Risk factors for nosocomial infection in a high-risk nursery.
PMID- 10782585
TI - Once MRSA, always MRSA? Setting up a hospital preadmission questionnaire.
PMID- 10782586
TI - Good antimicrobial stewardship in the hospital: fitting, but flagrantly flagging.
PMID- 10782587
TI - Practices to improve antimicrobial use at 47 US hospitals: the status of the 1997
SHEA/IDSA position paper recommendations. Society for Healthcare Epidemiology of
America/Infectious Diseases Society of America.
AB - OBJECTIVE: To determine the status of programs to improve antimicrobial
prescribing at select US hospitals. DESIGN: Cross-sectional survey. PARTICIPANTS
AND SETTING: Pharmacy and infection control staff at all 47 hospitals
participating in phase 3 of Project Intensive Care Antimicrobial Resistance
Epidemiology. RESULTS: All 47 hospitals had some programs to improve
antimicrobial use, but the practices reported varied considerably. All used a
formulary, and 43 (91%) used it in conjunction with at least one of the other
three antimicrobial-use policies evaluated: stop orders, restriction, and
criteria-based clinical practice guidelines (CPGs). CPGs were reported most
commonly (70%), followed by stop orders (60%) and restriction policies (40%).
Although consultation with an infectious disease physician (70%) or pharmacist
(66%) was commonly used to influence initial antimicrobial choice, few (40%)
reported a system to measure compliance with these consultations. CONCLUSIONS: In
most hospitals surveyed, practices to improve antimicrobial use, although
present, were inadequate based on recommendations in a Society for Healthcare
Epidemiology of America and Infectious Disease Society of America joint position
paper. There is room to improve antimicrobial-use stewardship at US hospitals.
PMID- 10782588
TI - Nosocomial infections in pediatric patients: a European, multicenter prospective
study. European Study Group.
AB - OBJECTIVES: To determine the site and bacterial epidemiology of nosocomial
infections (NIs) in children. DESIGN: 6-month prospective study with periodic
chart review during hospitalization using a uniform prospective questionnaire in
each unit, analyzed at a coordinating center. SETTING: 20 units in eight European
countries: 5 pediatric intensive care units (PICUs), 7 neonatal units, 2
hematology-oncology units, 8 general pediatric units. PARTICIPANTS: All children
hospitalized during the study period with an NI according to Centers for Disease
Control and Prevention criteria. RESULTS: The overall incidence of NI was 2.5%,
ranging from 1% in general pediatric units to 23.6% in PICUs. Bacteria were
responsible for 68% (gram-negative bacilli, 37%; gram-positive cocci, 31%),
Candida for 9%, and viruses for 22% of cases. The proportion of lower respiratory
tract infections was 13% in general pediatric units and 53% in PICUs. Bloodstream
infections were most frequent in neonatal units (71% of NIs) and were associated
with a central venous catheter in 66% of cases. Coagulase-negative Staphylococcus
(CNS) was the main pathogen. Eleven percent of NI were urinary tract infections.
Gastrointestinal infections were most commonly viral and accounted for 76% of NIs
in general pediatric units. The prevalence of antimicrobial resistance depended
on the type of unit. The highest rates were observed in PICUs: 26.3% of
Staphylococcus aureus and 89% of CNS were methicillin-resistant, and 37.5% of
Klebsiella pneumoniae had an extended-spectrum beta-lactamase. Mortality due to
NI was 10% in PICUs and 17% in neonatal units. CONCLUSIONS: We found large
differences in NI frequency and microbial epidemiology in this European study.
Viruses were the main pathogens in general pediatrics units. Catheter-related
sepsis and CNS were frequent in newborns. A high frequency of multiresistant
bacteria was observed in some units. Clinical monitoring of NIs and bacterial
resistance profiles are required in all pediatric units.
PMID- 10782589
TI - Comparison of higher-dose intradermal hepatitis B vaccination to standard
intramuscular vaccination of healthcare workers.
AB - OBJECTIVE: To compare the immunogenicity of hepatitis B vaccine administered via
intradermal (ID) versus intramuscular (IM) route. METHODS: Subjects chose either
to specify the route of immunization or to undergo random allocation to
vaccination by the ID (0.15 mL) or the IM (1.0 mL) route. Yeast-derived
recombinant hepatitis B vaccine was given at 0, 30, and 180 days. Hepatitis B
surface antibody (HBsAb) and hepatitis B core antibody (HBcAb) were measured by
microparticle enzyme immunoassay. RESULTS: 763 subjects were enrolled. Baseline
screening identified 65 subjects (8%) who were positive for HBsAb or HBcAb.
Vaccination was completed by 590 (85%) of 698 enrollees (370 ID, 220 IM).
Seroconversion rates (geometric mean titers [GMT]>0 IU/mL HBsAb) for those
vaccinated ID were 99% and 96% for screening at 9 months and 1 year post
vaccination, respectively; subjects vaccinated intramuscularly had similar rates
of 95% and 96%. Seropositivity rates (GMT > or = 10 IU/mL HBsAb) showed a similar
pattern, with 95%, 92%, and 73% at 9 months and 1 and 2 years, respectively, for
those vaccinated ID, and 94%, 93%, and 81% for those having IM vaccination. GMT
for HBsAb was significantly higher for individuals vaccinated IM than for those
vaccinated ID (P<.0001). The GMT ratio for the IM and ID routes decreased over
time, being 9.3 at 9 months, 7.8 at 1 year, and 5.9 at 2 years. An unanticipated
side effect of intradermal vaccination was skin discoloration at injection sites,
which persisted for at least 2 years postvaccination. Two thirds (112/166) of
respondents reported that they would have selected the ID route despite the
discoloration. CONCLUSIONS: Higher-dose ID vaccination (3 vs 1 microg per
injection) uses one sixth of the dose required for standard IM vaccination. It is
a cost-effective way to vaccinate populations against hepatitis B virus, but the
long-term efficacy of the ID route must still be investigated.
PMID- 10782590
TI - Evidence of delays in transferring patients with methicillin-resistant
Staphylococcus aureus or vancomycin-resistant Enterococcus to long-term-care
facilities.
AB - This retrospective case-control study examined whether there was a difference in
length of time awaiting long-term-care placement for patients identified as
having methicillin-resistant Staphylococcus aureus or vancomycin-resistant
Enterococcus compared to controls. Thirty-nine patients with methicillin
resistant Staphylococcus aureus or vancomycin-resistant Enterococcus waited for
placement an average of 61 days longer than controls (P<.0002). The average
number of requests for placement was 2.5 compared to 1.7 for controls (P=.015).
PMID- 10782591
TI - The incidence and risk factors of ventilator-associated pneumonia in a Riyadh
hospital.
AB - We report the incidence of, and risk factors for, ventilator-associated pneumonia
(VAP) at the King Fahad National Guard Hospital. Of the 202 patients studied, 41
(25.2%) had VAP. The incidence density was 16.8/1,000 person-days of ventilation.
Variables significantly associated with VAP were serious injury from motor
vehicle accident, enteral feeding, and length of ventilation. The avoidance of
unnecessary enteral nutrition could help to reduce VAP.
PMID- 10782592
TI - O2 in Y2K: not an airtight case.
PMID- 10782593
TI - Diagnostic tests: distinguishing good tests from bad and even ugly ones.
AB - This article focuses on the selection and interpretation of diagnostic tests,
emphasizing the importance of understanding how their mathematical parameters
affect the information they provide in various settings. The utility and
limitations of sensitivity, specificity, predictive value, and receiver operating
characteristic (ROC) curves are discussed using catheter-related bloodstream
infections as an example. ROC curves have been used for selecting optimal cutoff
values for a positive result and for selecting among several alternative
diagnostic tests. For example, 16 different tests have been proposed for
diagnosis of catheter-related bloodstream infection; ROC analysis provides an
effective way to determine which test offers the best overall performance.
PMID- 10782594
TI - Attitudes of Finnish dog-owners about programs to control canine genetic
diseases.
AB - A mailed questionnaire survey was done to study dog-owners' knowledge of canine
inherited diseases and the present screening and control programs in Finland, as
well as to study the importance of health-related matters and well-being to dog
owners. The purpose was also to study the owners' role in programs and the
influence of health and well-being in their decision-making process and choices
when purchasing a puppy. This study showed that dog-owners highly valued health
related matters and well-being. The present programs were considered to have a
positive effect on the prevention of canine inherited diseases. Dog-owners
estimated that their own knowledge could be better but they believed in
veterinarians' and dog-breeders' ability to inform them. Inherited skeletal and
ocular diseases were thought to be important to canine well-being; the importance
of other diseases or behaviour problems was assessed to be lower. In choosing a
suitable breed, behaviour and temperament were the most-important factors but
health-related matters were essential in actually choosing a puppy's breeder and
the litter. Well-being and health were also considered very important to the
image of the dog hobby.
PMID- 10782595
TI - Attitudes of Finnish dog-breeders about programs to control canine genetic
diseases.
AB - A questionnaire was mailed to 320 Finnish dog-breeders to study breeders'
knowledge of canine inherited diseases and of the present screening and control
programs in Finland. The purpose was also to study the breeders' attitudes about
and compliance with such programs. Breeders estimated that their knowledge was
quite good, and they also believed in their ability to influence other groups and
to promote the programs. The present programs were considered to have a positive
effect on the prevention of canine inherited diseases, but information given to
breeders and other key groups could produce even better results. Inherited
skeletal and ocular diseases were thought to be important to canine well-being;
the importance of other diseases was assessed to be lower.
PMID- 10782596
TI - Risk factors for fecal shedding of Salmonella in 91 US dairy herds in 1996.
AB - In 1996, data on management practices used on US dairy operations were collected
and analyzed for association with fecal shedding of Salmonella by dairy cows. A
total of 4299 fecal samples from 91 herds was cultured for Salmonella isolation.
Herd-size (adjusted odds ratios (OR) = 5.8, 95% CI 1.1, 31.3), region (OR = 5.7,
CI 1.4, 23.5), use of flush water systems (OR = 3.5, CI 0.9, 14.7), and feeding
brewers' products to lactating cows (OR = 3.4, CI 0.9, 12.9) were identified as
the most important predictive risk factors. The population attributable risks
(PARs) for herd-size, region, flush water system, and feeding brewers' products
to lactating cows were 0.76, 0.46, 0.37, and 0.42, respectively. The estimated
PAR for all four risk factors combined was 0.95. The effects of these factors
need to be more-closely evaluated in more-controlled studies, in order to develop
intervention programs that reduce Salmonella shedding.
PMID- 10782597
TI - Time-space clustering of reported blowfly strike in Queensland sheep flocks.
AB - The reported occurrence of blowfly strike in 57 sheep flocks in Queensland,
Australia, was investigated for time-space clustering in an exploratory study
using Knox's method. Flystrike occurrence peaked in late spring and early summer,
with an additional late-autumn peak in southern-Queensland flocks. A total of
1596 case-pairs was examined. Significant clustering (P = 0.07) was only detected
for case-pairs occurring within 3 months and 150 km of each other; 164 case-pairs
were declared close compared to an expectation of 151. We suggest that factors
common to a district (such as rainfall and temperature) are responsible for
clustering of flystrike in Queensland.
PMID- 10782598
TI - A clinical trial to evaluate the effects of flumethrin or ivermectin treatment on
hemoparasites, gastrointestinal parasites, conception and daily weight gain in a
dairy farm in Japan.
AB - A clinical trial was performed to compare the effects of flumethrin and
ivermectin treatments of grazing heifers at one farm in central Japan. 64 heifers
were randomly allocated into two groups. Flumethrin (1 mg/kg pour on) was applied
approximately once every 3 weeks to heifers in one group and heifers in the
second group were injected approximately once every month with ivermectin (200
microg/kg; id). Between groups, no significant differences were detected in the
proportions of animals that showed parasitemia of Theileria sergenti and
conception risks. Significantly lower average log-transformed nematode-egg counts
and higher average daily weight gain were observed in the ivermectin-treated
group. Animals with higher body weight at the start of grazing and lower log
transformed total nematode-egg and coccidia-oocyst counts had higher odds of
conceiving. Animals with ivermectin treatment, lower body weight at the start of
grazing and lower log-transformed coccidia-oocyst count had higher daily weight
gain. Ivermectin may be more useful in this farm because of the higher
productivity for cattle and lower cost for its usage.
PMID- 10782599
TI - Use of a non-linear spline regression to model time-varying fluctuations in
mammary-secretion element concentrations of periparturient mares in Michigan,
USA.
AB - A study was designed to model the fluctuations of nine specific element
concentrations in mammary secretions from periparturient mares over time. During
the 1992 foaling season, serial samples of mammary secretions were collected from
all 18 pregnant Arabian mares at the Michigan State University equine teaching
and research center. Non-linear regression techniques were used to model the
relationship between element concentration in mammary secretions and days from
foaling (which connected two separate sigmoid curves with a spline function);
indicator variables were included for mare and mare parity. Element
concentrations in mammary secretions varied significantly during the
periparturient period in mares. Both time trends and individual variability
explained a significant portion of the variation in these element concentrations.
Multiparous mares had lower concentrations of K and Zn, but higher concentrations
of Na. Substantial serial and spatial correlation were detected in spite of
modeling efforts to avoid the problem. As a result, p-values obtained for
parameter estimates were likely biased toward zero. Nonetheless, results of this
analysis indicate that monitoring changes in mammary-secretion element
concentrations might reasonably be used as a predictor of impending parturition
in the mare. In addition, these results suggest that element concentrations
warrant attention in the development of neonatal milk-replacement therapies. This
study demonstrates that non-linear regression can be used successfully to model
time-series data in animal-health management. This approach should be considered
by investigators facing similar analytical challenges.
PMID- 10782600
TI - EMSC partnership for children: National Association of EMS Physicians model
pediatric protocols.
PMID- 10782601
TI - Usage of emergency medical services by children with special health care needs.
AB - OBJECTIVE: To describe the usage of emergency medical services (EMS) by children
with special health care needs (CSHCN). METHODS: All EMS runs and related
hospital records for children aged 0-17 years in Utah in 1991-92 were linked. The
CSHCN status was determined from ICD-9 diagnoses using three available
definitions. The amounts of EMS usage were compared between CSHCN and other
children. A pediatric intensive care practitioner determined CSHCN status by
chart review for 915 children transported by EMS to a pediatric tertiary care
hospital, and his classification was compared with the CSHCN status assigned by
the three ICD-9-based definitions. RESULTS: The three definitions assigned CSHCN
status for 2% to 24% of children using EMS. When compared with other children,
CSHCN were more likely to be admitted to the hospital, more likely to use EMS for
transfer between health care facilities, and more likely to receive prehospital
procedures such as intravenous therapy. In the group of children whose charts
were reviewed individually, one ICD-9-based definition most closely agreed to
determination of CSHCN status by a pediatric intensive care practitioner.
CONCLUSIONS: Children with special health care needs who use EMS are more likely
to receive advanced life support service, to receive prehospital procedures, and
to be transferred from one health care facility to another. There is need for a
specific and measurable definition of CSHCN that can be applied to existing
health data.
PMID- 10782602
TI - U.S. Army air ambulance operations in El Paso, Texas: a descriptive study and
system review.
AB - OBJECTIVES: To analyze a high-volume military air ambulance unit and review the
U.S. Army air medical transport system and Military Assistance to Safety and
Traffic (MAST) program. METHODS: The setting was a remote medical system with
numerous ground emergency medical services. All patients transported between
January 1, 1996, and February 28, 1998, were included. Patients who were dead on
scene or for whom records were unavailable were excluded. A retrospective review
of transport and available inpatient records was conducted. RESULTS: Five hundred
seventeen patients were transported during the study period; 461 patients met
inclusion criteria (89%). Of these, 70% were classified as trauma; 30% possessed
medical or other surgical diagnoses. Prehospital responses numbered 71.6%, while
28.4% were interhospital transfers. Missions averaged 23.4 minutes per flight,
with no major aircraft mishaps. Prehospital utilization review showed appropriate
use; 35% of interhospital trauma and 11% of interhospital nontrauma missions were
staffed inadequately by these criteria. Time intervals, procedures, and program
impact are discussed. CONCLUSION: This and similar units participating in the
MAST program provide effective air transport in settings underserved by civilian
programs. Quality and wartime readiness could be improved by centralized medical
direction, treatment and transfer protocols, and enhanced training of medics.
Further investigations of the clinical impact of advanced training and a two
medic aircrew model are warranted.
PMID- 10782603
TI - Study design and outcomes in out-of-hospital emergency medicine research: a ten
year analysis.
AB - OBJECTIVE: Lack of rigorous study design and failure to follow diverse patient
outcomes have been identified as critical gaps in the medical research
literature. This study sought to determine whether similar gaps exist in the
literature for out-of-hospital interventions. METHODS: A computerized MEDLINE
search was conducted for the ten-year period 1985 through 1994 using the MeSH
terms "emergency medical services," "prehospital," and "transportation of
patients." Using a standard abstraction form, two investigators independently
analyzed articles meeting these inclusion criteria: original research evaluating
an out-of-hospital intervention and measuring a patient outcome. Study design was
categorized in order of scientific rigor, moving from case series to randomized
trial. Measures of outcomes were classified into the six Ds: death, disease,
discomfort, disability, dissatisfaction, and debt (cost). RESULTS: Interobserver
agreement was high (kappa = 0.80). For the ten-year period, 3,686 titles, 1,454
abstracts, and 373 articles were examined serially; all 285 studies meeting
inclusion criteria were analyzed. Case series (44%) was the most frequently used
design, while only 15% were randomized trials. The majority of the studies were
retrospective (53%). A single outcome was assessed in 45% of the articles; 41%
measured two outcomes, 13% three outcomes, and 1% four outcomes. Death and
disease were the most common outcomes evaluated. Disability, debt, discomfort,
and dissatisfaction were infrequently measured. CONCLUSION: Studies of out-of
hospital emergency medical interventions are limited in the scientific rigor of
study design and the diversity of patient outcomes measured. To adequately assess
the effectiveness of out-of-hospital care, efforts should be directed toward
strengthening study designs and examining the full range of patient outcomes.
PMID- 10782604
TI - Justification of pulse oximeter costs for paramedic prehospital providers.
AB - OBJECTIVE: To assess the potential cost savings of decreasing prehospital oxygen
utilization by using pulse oximetry to identify those patients who do not require
supplemental oxygen. METHODS: A prospective, controlled trial was performed
comparing rates of oxygen utilization by paramedics with and without access to
pulse oximetry. Consecutive patient encounters over a ten-week period were
randomized by day of presentation. Pulse oximeters were made available on
alternate days. On those days, patients whose oxygen saturations were less than
95% were treated with supplemental oxygen. RESULTS: The use of pulse oximeters
incurred a saving of 0.14 "D"-size oxygen cylinders per call. For the authors'
service, this translates to a potential saving of $2,324 (C)/vehicle/year.
CONCLUSION: For regions with patient demographics similar to the authors', the
initial cost of providing paramedics with pulse oximeters may be offset by
savings in oxygen consumption. A formula is provided to allow individual
ambulance services to calculate the potential savings for their service.
PMID- 10782605
TI - Appropriateness of intravenous cannulation by paramedics: a London study.
AB - INTRODUCTION: The number of patients undergoing intravenous (IV) cannulation by
paramedics has increased dramatically over recent years in the UK. Treatment
protocols for cannulation in the field are loosely defined. Variation in practice
may lead to patients' receiving differential treatment according to customary
practice, rather than according to their clinical conditions. OBJECTIVES: To
explore variations in practice and assess level of appropriatenesss of IV
cannulation by London Ambulance Service (LAS) paramedics; to revise treatment
protocols and work toward clinical guidelines, if indicated by study findings.
METHODS: Skill usage data were analyzed for all LAS paramedics for 1995-96. All
patients who were IV-cannulated and transported to three hospitals by LAS during
March 1996 were identified. A panel of accident and emergency (A&E) and
prehospital specialists judged each case for appropriateness. RESULTS: Variation
during the year was wide, with a range of 1 to 221 (mean 47) patients cannulated
per paramedic, although the majority showed some consistency in frequency of
skill usage. A sample of 183 cases was reviewed. The majority judged 149 (81.4%)
to be appropriate, although there was considerable disagreement between reviewers
(kappa = 0.43, p < 0.001). Data suggested that those paramedics who cannulate
more frequently cannulated less appropriately during the study period (lowest
30%: 73.9% appropriate; highest 30%: 45.8% appropriate, p = 0.05). CONCLUSION:
Despite wide variation between paramedics, the panel judged overall
appropriateness of cannulation to be high. The audit advisory group judged that
new clinical guidelines might not achieve an improvement in practice and were not
supported by study findings. It was recommended that variations be addressed
through individual practice review.
PMID- 10782606
TI - An assessment of paramedic performance during invasive airway management.
AB - OBJECTIVE: To assess the performance of paramedics, in a newly-initiated
prehospital program, during invasive airway management. METHODS: An audit of
paramedic call reports for a 12-month period from January to December 1997 was
performed. Call reports that documented invasive airway management were retrieved
and relevant data were extracted using a preformulated data-entry form. RESULTS:
Paramedics attempted tracheal intubation in 453 patients and were successful in
408 (90.1%); 331 of the patients were in cardiopulmonary arrest with vital signs
absent (VSA), 101 had medical emergencies, and 21 had trauma-related problems. In
the VSA cohort, the tracheas of 96% of the patients were intubated successfully;
80.1% on the first attempt, 10.6% on the second, 4.5% on the third, and 0.9%
after more than three attempts. In the medical cohort, the tracheas of 74.3% of
the patients were intubated; 60.4% on the first attempt, 11.9% on the second, and
2.9% on the third. In the trauma cohort, 71.4% of the intubations were
successful; 66.6% on the first attempt, 26.6% on the second, and 6.6% on the
third. There was a difference (p < 0.001) in the incidence of successful
intubations comparing the VSA cohort with the medical/trauma cohorts. There was
also a difference (p < 0.001) between the success rate for nasal intubations (43
of 68, 63% of patients successfully intubated) and that for oral intubation (365
of 385, 94% of patients). CONCLUSION: This study demonstrated a difference in the
paramedics' success rates for tracheal intubation in VSA patients compared with
those with preserved airway reflexes and a lower success rate for nasal vs oral
tracheal intubation. These differences may be due to inadequate training,
technical difficulties experienced in the field, or lack of sufficient exposure
to medical/trauma scenarios to gain management experience. Future training to
address these issues, both in the initial training phase and in the continuing
education program, may be beneficial in improving performance.
PMID- 10782607
TI - The laryngeal tube: a new adjunct for airway management.
AB - INTRODUCTION: A prototype of the laryngeal tube was tested for simple and
reliable use for ventilation in a mannequin. One possible use of this tube will
be the management of the difficult airway. In spite of blind insertion, an
inadvertent tracheal positioning should not occur due to the form of the tube. A
pharyngeal cuff provides a proximal seal of the airway, while an esophageal cuff
seals the airway distally and prevents aspiration of gastric contents. A ventral
opening between both cuffs is used for ventilation. OBJECTIVE: To examine the
reliability of the laryngeal tube for airway management in a mannequin. METHODS:
Fifty physicians and nurses were included in this study and inserted the
laryngeal tube blindly during ten consecutive attempts in an advanced life
support mannequin. All participants used the laryngeal tube for the first time.
RESULTS: During 500 insertions of the tube, correct placement and sufficient
ventilation were achieved 478 times in the first attempt (95.6%); 18 times
(3.6%), inflating the proximal balloon with an additional 50 mL of air led to
sufficient ventilation. In four attempts (0.8%), sufficient ventilation was still
not possible due to the tube's not being placed deep enough (according to the
printed ring marks on the tube). In each case, the tube was placed correctly in
the following attempt. Neither a tracheal intubation nor ventilation of the
stomach could be observed. The average time for positioning the laryngeal tube
was 27.15 seconds for all 500 attempts (average time of the 50 participants for
the tenth attempt: 23.85 seconds). CONCLUSION: The laryngeal tube may be a fast,
reliable, and easy device for airway management. Further research is necessary.
PMID- 10782608
TI - A new system for sternal intraosseous infusion in adults.
AB - BACKGROUND: Intraosseous (IO) infusion provides an alternative route for the
administration of fluids and medications when difficulty with peripheral or
central lines is encountered during resuscitation of critically ill and injured
patients. OBJECTIVE: To report the first 50 uses of a new system for emergency IO
infusion into the sternum in adults, the Pyng F.A.S.T.1 IO infusion system.
METHODS: Six emergency departments and five prehospital emergency medical
services (EMS) sites in Canada and the United States provided clinical and/or
research data on their use of the IO system in a pilot study of success rates,
insertion times, and complications. Indications for use included adult patient,
urgent need for fluids or medications, and unacceptable delay or inability to
achieve standard vascular access. A basic data set was standardized for all
sites, and some sites collected additional data. RESULTS: The overall success
rate for achieving vascular access with the system was 84%. Success rates were
74% for first-time users, and 95% for experienced users. Failure to achieve
vascular access occurred most frequently in patients (5 of 9) described
subjectively by the user as "very obese," in whom there was a thick layer of
tissue overlying the sternum. Mean time to achieve vascular access was 77
seconds. Flow rates of up to 80 mL/min were reported for gravity drip, and more
than 150 mL/min by syringe bolus. Pressure cuffs were also used successfully,
although fluid rate was controlled by clamping the line. Further research on flow
rates is needed. No complications or complaints were reported at two-month follow
up. CONCLUSION: These early data indicate that sternal IO infusion using the new
F.A.S.T.1 IO system may provide rapid, safe vascular access and may be a useful
technique for reducing unacceptable delays in the provision of emergency
treatment.
PMID- 10782609
TI - Training paramedics: emergency care for children with special health care needs.
AB - OBJECTIVE: To enhance knowledge and comfort related to the emergency care of
children with special health care needs (CSHCN) through an innovative continuing
education program for paramedics. METHODS: A self-study program presenting in
depth information about common problems that affect the assessment and management
of a child's airway, breathing, circulation, disability, and environment
(ABCDEs), regardless of the child's diagnosis, was developed. This program used a
manual, a video, practice mannequins, and skills evaluations to teach skills to
paramedics employed at a municipal fire department. RESULTS: Pre- and
posttraining surveys found that the paramedics were significantly more
comfortable with the assessment and management of CSHCN after the completion of
the self-study program, with a pretraining average of 2.83 and posttraining
average of 4.20 on a five-point Likert-type scale, t(37) = 12.87, p < 0.001. A
skills evaluation showed that skills performance varied widely across 21 skills,
ranging from skills mastery to low skills knowledge. On the posttraining survey,
between 74% and 94% of the paramedics rated each topic (tracheostomies,
indwelling central venous catheters, cerebrospinal fluid shunts, gastrostomies,
child abuse, and latex allergy) as applicable to their practices as paramedics.
CONCLUSION: Given the growing population of CSHCN, it is important to provide
specialized education to increase an EMS provider's preparedness to respond to
emergency situations involving children with special health care needs.
PMID- 10782610
TI - The use of emergency medical dispatch protocols to reduce the number of
inappropriate scene responses made by advanced life support personnel.
AB - OBJECTIVES: To determine whether implementation of an emergency medical dispatch
(EMD) system would reduce the rate of inappropriate advanced life support (ALS)
utilization, and enable more accurate identification of those patients requiring
ALS care. METHODS: An emergency medical services (EMS) site providing basic life
support (BLS) and ALS care to a population of 200,000 served as the study site
for calendar year 1996. This study compared the prospective identification of
patients as ALS or BLS using EMD with that using chief complaint-based dispatch
criteria. Each patient served as his or her own control. The ALS or BLS priority
was assigned using both chief complaint and EMD criteria. Chief complaint-based
dispatching meant that all patients with preestablished chief complaints received
ALS without further triage questions, while EMD allowed the dispatchers to
question callers using a scripted set of questions. The outcome measures included
the number of calls categorized as ALS or BLS, the number of calls cancelled by
BLS, and the number of ALS calls released to BLS care. Yates-corrected chi-square
was used for statistical analysis. RESULTS: There were 11,174 patients enrolled.
The use of EMD was associated with a significant decrease in the proportion of
calls designated as ALS (44.7% vs 55.8%, p < 0.0001), as well as a significant
decrease in the number of ALS responses cancelled by BLS (9.2% vs 23.8%, p <
0.0001) and patients released to BLS by medical control (4.7% vs 7.3%, p <
0.0001). CONCLUSIONS: Implementation of an EMD system significantly decreased
inappropriate ALS dispatching, as defined by decreased rate of ALS cancellations
and BLS releases. Further study is needed to see whether other EMD dispatch
models may further refine ALS dispatch.
PMID- 10782611
TI - Termination of resuscitation in the prehospital setting for adult patients
suffering nontraumatic cardiac arrest. National Association of EMS Physicians
Standards and Clinical Practice Committee.
AB - The National Association of EMS Physicians (NAEMSP) supports out-of-hospital
termination of resuscitation for adult, nontraumatic cardiac arrest patients who
have not responded to full resuscitative efforts. The following factors should be
considered in establishing termination of resuscitation protocols: 1) Termination
of resuscitation may be considered for any adult patient who suffers sudden
cardiac death that is likely to be medical. 2) Unwitnessed cardiac arrest with
delayed initiation of cardiopulmonary resuscitation (CPR) beyond 6 minutes and
delayed defibrillation beyond 8 minutes has a poor prognosis. 3) In the absence
of "do not resuscitate" or advanced directives, a full resuscitative effort
including CPR, definitive airway management, medication administration,
defibrillation if necessary, and at least 20 minutes of treatment following
Advanced Cardiac Life Support (ACLS) guidelines should be performed prior to
declaring the patient dead. 4) A patient whose rhythm changes to, or remains in,
ventricular fibrillation or ventricular tachycardia should have continued
resuscitative efforts. Patients in asystole or pulseless electrical activity
should be strongly considered for out-of-hospital termination of resuscitation.
5) Logistic factors should be considered, such as collapse in a public place,
family wishes, and safety of the crew and public. 6) Online medical direction
should be established prior to termination of resuscitation. The decision to
terminate efforts should be a consensus between the on-scene paramedic and the
online physician. 7) The on-scene providers and family should have access to
resources, such as clergy, crisis workers, and social workers. 8) Quality review
is necessary to ensure appropriate application of the termination protocol, law
enforcement notification, medical examiner or coroner involvement, and family
counseling.
PMID- 10782612
TI - Refractory asystole and death following the prehospital administration of
adenosine.
PMID- 10782613
TI - Misplaced tubes.
PMID- 10782614
TI - Reconstruction algorithm for polychromatic CT imaging: application to beam
hardening correction.
AB - This paper presents a new reconstruction algorithm for both single- and dual
energy computed tomography (CT) imaging. By incorporating the polychromatic
characteristics of the X-ray beam into the reconstruction process, the algorithm
is capable of eliminating beam hardening artifacts. The single energy version of
the algorithm assumes that each voxel in the scan field can be expressed as a
mixture of two known substances, for example, a mixture of trabecular bone and
marrow, or a mixture of fat and flesh. These assumptions are easily satisfied in
a quantitative computed tomography (QCT) setting. We have compared our algorithm
to three commonly used single-energy correction techniques. Experimental results
show that our algorithm is much more robust and accurate. We have also shown that
QCT measurements obtained using our algorithm are five times more accurate than
that from current QCT systems (using calibration). The dual-energy mode does not
require any prior knowledge of the object in the scan field, and can be used to
estimate the attenuation coefficient function of unknown materials. We have
tested the dual-energy setup to obtain an accurate estimate for the attenuation
coefficient function of K2 HPO4 solution.
PMID- 10782615
TI - Volume rendering quantification algorithm for reconstruction of CT volume
rendered structures: Part I. Cerebral arteriovenous malformations.
AB - Volume rendering is a visualization technique that has important applications in
diagnostic radiology and in radiotherapy but has not achieved widespread use due,
in part, to the lack of volumetric analysis tools for comparison of volume
rendering to conventional visualization techniques. The volume rendering
quantification algorithm (VRQA), a technique for three-dimensional (3-D)
reconstruction of a structure identified on six principal volume-rendered views,
is introduced and described. VRQA involves three major steps: 1) preprocessing of
the partial surfaces constructed from each of six volume-rendered images; 2)
merging these processed partial surfaces to define the boundaries of a volume;
and 3) computation of the volume of the structure from this boundary information.
After testing on phantoms, VRQA was applied to CT data of patients with cerebral
arteriovenous malformations (AVM's). Because volumetric visualization of the
cerebral AVM is relatively insensitive to operator dependencies, such as the
choice of opacity transfer function, and because precise volumetric definition of
the AVM is necessary for radiosurgical treatment planning, it is representative
of a class of structures that is ideal for testing and calibration of VRQA. AVM
volumes obtained using VRQA are intermediate to those obtained using axial
contouring and those obtained using CT-correlated biplanar angiography (two
routinely used visualization techniques for treatment planning for AVM's).
Applications and potential expansions of VRQA are discussed.
PMID- 10782616
TI - Probabilistic modeling of single-trial fMRI data.
AB - This paper describes a probabilistic framework for modeling single-trial
functional magnetic resonance (fMR) images based on a parametric model for the
hemodynamic response and Markov random field (MRF) image models. The model is
fitted to image data by maximizing a lower bound on the log likelihood. The
result is an approximate maximum a posteriori estimate of the joint distribution
over the model parameters and pixel labels. Examples show how this technique can
used to segment two-dimensional (2-D) fMR images, or parts thereof, into regions
with different characteristics of their hemodynamic response.
PMID- 10782617
TI - Point-tracked quantitative analysis of left ventricular surface motion from 3-D
image sequences.
AB - We propose and validate the hypothesis that we can use differential shape
properties of the myocardial surfaces to recover dense field motion from standard
three-dimensional (3-D) image sequences (MRI and CT). Quantitative measures of
left ventricular regional function can be further inferred from the point
correspondence maps. The noninvasive, algorithm-derived results are validated on
two levels. First, the motion trajectories are compared to those of implanted
imaging-opaque markers of a canine model in two imaging modalities, where
subpixel accuracy is achieved. Second, the validity of using motion parameters
(path length and thickness changes) for detecting myocardial injury area is
tested by comparing algorithms derived results to postmortem analysis TTC
staining of myocardial tissue, where the achieved Pearson product-moment
correlation value is 0.968.
PMID- 10782618
TI - Consistency conditions and linear reconstruction methods in diffraction
tomography.
AB - Because an image can be reconstructed from knowledge of its Radon transform (RT),
the task of reconstructing an image is tantamount to that of estimating its RT.
Based upon the Fourier diffraction projection (FDP) theorem, from the statistical
perspective of unbiased reduction of image variance, we previously proposed an
infinite family of estimation methods for obtaining the RT from the scattered
data in diffraction tomography (DT). In this work, using the FDP theorem, we
define the diffraction Radon transform (DRT), which can be treated as the data
function in DT. Subsequently, using strategies similar to those that analyze the
consistency conditions on the exponential Radon transform in two-dimensional (2
D) single-photon emission computed tomography with uniform attenuation, we
studied the consistency condition on the DRT and we show that there is a
hierarchy of estimation methods that actually project the noisy data function
onto its consistency space in different ways. In terms of a weighted inner
product of the consistency and inconsistency parts of a noisy data function, we
further demonstrate that a subset of the family of estimation methods can be
interpreted as orthogonal projections onto the consistency space of the DRT. In
particular, the statistically suboptimal estimation method in the family
corresponds to an orthogonal projection associated with an ordinary inner product
of the consistency and inconsistency parts of a noisy data function.
PMID- 10782619
TI - An ultra-fast user-steered image segmentation paradigm: live wire on the fly.
AB - We have been developing general user steered image segmentation strategies for
routine use in applications involving a large number of data sets. In the past,
we have presented three segmentation paradigms: live wire, live lane, and a three
dimensional (3-D) extension of the live-wire method. In this paper, we introduce
an ultra-fast live-wire method, referred to as live wire on the fly, for further
reducing user's time compared to the basic live-wire method. In live wire, 3
D/four-dimensional (4-D) object boundaries are segmented in a slice-by-slice
fashion. To segment a two-dimensional (2-D) boundary, the user initially picks a
point on the boundary and all possible minimum-cost paths from this point to all
other points in the image are computed via Dijkstra's algorithm. Subsequently, a
live wire is displayed in real time from the initial point to any subsequent
position taken by the cursor. If the cursor is close to the desired boundary, the
live wire snaps on to the boundary. The cursor is then deposited and a new live
wire segment is found next. The entire 2-D boundary is specified via a set of
live-wire segments in this fashion. A drawback of this method is that the speed
of optimal path computation depends on image size. On modestly powered computers,
for images of even modest size, some sluggishness appears in user interaction,
which reduces the overall segmentation efficiency. In this work, we solve this
problem by exploiting some known properties of graphs to avoid unnecessary
minimum-cost path computation during segmentation. In live wire on the fly, when
the user selects a point on the boundary the live-wire segment is computed and
displayed in real time from the selected point to any subsequent position of the
cursor in the image, even for large images and even on low-powered computers.
Based on 492 tracing experiments from an actual medical application, we
demonstrate that live wire on the fly is 1.3-31 times faster than live wire for
actual segmentation for varying image sizes, although the pure computational part
alone is found to be about 120 times faster.
PMID- 10782620
TI - Computer-aided stereotactic functional neurosurgery enhanced by the use of the
multiple brain atlas database.
AB - This paper introduces a computer-aided atlas-based functional neurosurgery
methodology and describes NeuroPlanner, a software system which supports it.
NeuroPlanner provides four groups of functions: 1) data-related for data reading,
interpolation, reformatting, and image processing; 2) atlas-related for multiple
atlases reading, atlas-to-data global and local registrations, two-way anatomical
indexing, and multiple labeling in two and three dimensions; 3) atlas-data
exploration-related for three-dimensional (3-D) display and real-time
manipulation of cerebral structures, continuous navigation, two-dimensional (2
D), triplanar, 3-D presentations, and 2-D interaction in four views; and 4)
neurosurgery-related for targeting, trajectory planning, mensuration, simulating
the insertion of microelectrode, and simulating therapeutic lesioning. All
operations, excluding atlas and data reading, are real time. The combined
anatomical index of the multiple brain atlas database containing complementary 2
D and 3-D atlases has about 1000 structures per hemisphere, and over 400 sulcal
patterns. Neurosurgical planning with mutually preregistered multiple brain
atlases in all three orthogonal orientations is novel. The approach is validated
with 24 intraoperative and postoperative datasets for thalamotomies, thalamic
stimulations, pallidotomies, and pallidal stimulations. Its potential benefits
include increased accuracy of target definition, reduced time of the surgical
procedure by decreasing the number of tracts, facilitated planning of more
sophisticated trajectories, lowered cost by reducing the number of
microelectrodes used, reduced surgical complications, and the extra degree of
confidence given to the neurosurgeon.
PMID- 10782621
TI - Hypotony: What is it? How should we manage it?
PMID- 10782622
TI - Large diurnal fluctuations in intraocular pressure are an independent risk factor
in patients with glaucoma.
AB - PURPOSE: To study the risk associated with diurnal intraocular pressure (IOP)
variations in patients with open-angle glaucoma. PATIENTS AND METHODS: Sixty-four
patients (105 eyes) from the practices of two glaucoma specialists successfully
performed home tonometry with a self-tonometer five times a day for 5 days. All
patients had open-angle glaucoma and documented IOP below 25 mm Hg over a mean
follow-up period of 5 years. Baseline status and time to progression of visual
field loss were identified from the clinical charts. The level and variability of
diurnal IOP obtained using home tonometry were characterized. Risk of progression
was analyzed using a nonparametric time-to-event model, incorporating methods for
correlated outcomes. RESULTS: Although mean home IOP and baseline office IOP were
similar (16.4 +/- 3.6 mm Hg and 17.6 +/- 3.2 mm Hg, respectively), the average
IOP range over the 5 days of home tonometry was 10.0 +/- 2.9 mm Hg. Baseline
office IOP had no predictive value (relative hazard, 0.98). The diurnal IOP range
and the IOP range over multiple days were significant risk factors for
progression, even after adjusting for office IOP, age, race, gender, and visual
field damage at baseline (relative hazards [95% confidence intervals], 5.69
[1.86, 17.35] and 5.76 [2.21, 14.98]). Eighty-eight percent of patients in the
upper twenty-fifth percentile of IOP and 57% of patients in the lower twenty
fifth percentile progressed within 8 years. CONCLUSIONS: In patients with
glaucoma with office IOP in the normal range, large fluctuations in diurnal IOP
are a significant risk factor, independent of parameters obtained in the office.
Fluctuations in IOP may be important in managing patients with glaucoma.
Development of methods to control fluctuations in IOP may be warranted.
PMID- 10782623
TI - Crete, Greece glaucoma study.
AB - PURPOSE: To investigate the prevalence of primary open-angle glaucoma (POAG) in a
randomized sample of the inhabitants of the island of Crete. PATIENTS AND
METHODS: In 18 different villages in all four prefectures of the island of Crete,
patients were randomly selected from 1993 through 1998, and an in situ study was
accomplished. The sampling fraction (covered by the 1991 census) in each village
was approximately 5%. Patients were considered to have POAG when the morphologic
aspect of a glaucomatous optic disc was present, and/or a nerve fiber layer
defect and a visual field defect was present. The presence of Pseudoexfoliation
syndrome (PEX) and pseudoexfoliative glaucoma (PEXG) was also investigated.
RESULTS: The prevalence of glaucoma in Crete was 2.80%. Of those diagnosed with
POAG, 9.67% had an intraocular pressure (IOP) under 21 mm Hg, and 25.80% had PEX.
The prevalence of simple ocular hypertension without glaucoma was found in 6.58%
of the patients. The ratio of subjects with hypertensive glaucoma to those with
simple ocular hypertension was 1:2.6. CONCLUSION: The prevalence of POAG and
exfoliation glaucoma appears to be quite high in Crete. Further research will be
needed to set more accurate criteria for earlier diagnosis and to enable more
efficient organization of the health care system.
PMID- 10782625
TI - Diffuse and localized nerve fiber layer loss measured with a scanning laser
polarimeter: sensitivity and specificity of detecting glaucoma.
AB - PURPOSE: To differentiate normal from diseased retinal nerve fiber layers (NFL)
using a new method of analyzing polarimetry data that specifically targets
patterns of diffuse and localized NFL loss. METHODS: The NFL from a sample of 34
patients with primary open-angle glaucoma (POAG), 34 patients with ocular
hypertension, and 34 normal subjects were imaged using a scanning laser
polarimeter (GDx; Laser Diagnostic Technologies, Inc., San Diego, CA). Diffuse
loss was defined as a reduction in the peak-to-trough amplitude of the double
hump NFL pattern, and localized loss was defined as a lowering of the correlation
of thickness values between local regions shown previously to correspond in
normal subjects. RESULTS: Significant differences were found between the groups
of normal subjects, patients with hypertension, and patients for both the
amplitude and the correlational measures. The sensitivity and specificity
calculated using optimal criterion values were 94% and 91%, respectively.
CONCLUSIONS: These results suggest that NFL analysis targeting specific patterns
of loss may be beneficial for differentiating normal NFL patterns from diseased
NFL patterns, as well as for identifying patients at high risk.
PMID- 10782624
TI - Cost analysis of glaucoma medications.
AB - PURPOSE: To evaluate the yearly cost in 1998 of glaucoma medications to patients
and to the Health Plan at a university-affiliated teaching hospital with its own
health maintenance organization. MATERIALS AND METHODS: Data concerning Health
Plan glaucoma-medication prescriptions for 1998 were retrieved from the hospital
pharmacy database. RESULTS: The most costly medication per patient per year was
latanoprost (Xalatan; Pharmacia & Upjohn, Kalamazoo, MI [$337]), followed by
betaxolol hydrochloride (Betoptic-S; Alcon, Fort Worth, TX [$336]), dorzolamide
(Trusopt; Merck & Co., West Point, PA [$288]), brimonidine tartrate (Alphagan;
Allergan Pharmaceuticals, Irvine, CA [$260]), timolol maleate 0.5% in a gel
forming solution (Timoptic-XE 0.5%; Merck & Co., West Point, PA [$199]),
levobunolol hydrochloride (Betagan; Allergan Pharmaceuticals, Irvine, CA [$195]),
and generic timolol maleate 0.5% ($132). Cost per unit was greatest for Betoptic
S ($51), exceeding that of Trusopt ($43) and Xalatan ($43), Alphagan ($42),
Betagan ($38), Timoptic-XE 0.5% ($32), and timolol maleate 0.5% ($27).
CONCLUSION: Variability in the cost of medications may influence the long-term
medical management of glaucoma patients.
PMID- 10782626
TI - Electrophysiologic assessment of photoreceptor function in patients with primary
open-angle glaucoma.
AB - PURPOSE: Electroretinograms to high-intensity flashes were obtained to determine
the extent of rod and cone photoreceptor and postreceptor dysfunction in patients
with primary open-angle glaucoma. METHODS: Full-field flash electroretinograms
were obtained using brief high-intensity flashes. Dark-adapted (rod-dominated)
and light-adapted (cone-dominated) electroretinogram responses were recorded to a
"white" light as a function of flash intensity. The a-wave data were fitted with
a model based on photopigment transduction to obtain values for the parameters of
log Rmax (the maximum response) and log S (sensitivity). Oscillatory potentials
were measured to the cone-dominated high-intensity flashes. Standard clinical 30
Hz flicker electroretinogram responses were recorded using a Grass
photostimulator. RESULTS: Analysis of rod and cone a-wave data showed that log
Rmax and log S values were within the normal range in nearly all of the patients.
For some patients, oscillatory potentials were delayed beyond the normal range.
CONCLUSION: Our results provide little evidence for widespread photoreceptor
abnormalities in primary open-angle glaucoma.
PMID- 10782627
TI - Excisional bleb revision to correct overfiltration or leakage.
AB - OBJECTIVES: To evaluate the effectiveness of excisional revision of filtering
blebs for hypotony or leakage when more conservative measures have failed.
PATIENTS AND METHODS: Retrospective review of all patients who underwent
excisional revision of a filtering bleb for hypotony (intraocular pressure [IOP]
< 5 mm Hg) or leakage during a 3 year period. The revision consisted of excision
of the avascular bleb, mobilization of the surrounding conjunctiva, and suturing
of the conjunctiva at the limbus. RESULTS: Sixteen patients were included in the
study. The average age was 66.3 +/- 14.8 years (range, 39-83). Revision followed
trabeculectomy in 11 cases, combined phacoemulsification-trabeculectomy in three
cases, and inadvertent blebs in two cases. Five cases had bleb leaks without
hypotony, four cases had hypotony alone, and seven cases had both hypotony and a
bleb leak. Average follow-up after bleb revision was 25 +/- 11 months (range, 9
43). Average IOP increased from 3.8 +/- 5.6 mm Hg (range, 0-22) to 11.9 +/- 4.1
mm Hg (range, 3-18), with an average of 1.1 +/- 1.1 medication (range, 0-3). The
IOP at the last visit was < 15 mm Hg in all but two patients, with 10 of the 16
patients requiring medications. At the last follow-up examination, visual acuity
had improved > or = two lines in nine patients and was reduced two lines in one
patient. Five patients had early postoperative limbal wound leaks; resuturing was
required in one case. CONCLUSIONS: Excisional bleb revision is an effective
technique to correct hypotony or leakage after filtering surgery when other
methods have failed. Intraocular pressure control is often maintained with the
use of medications.
PMID- 10782628
TI - Long-term topical timolol and blood lipids: the Blue Mountains Eye Study.
AB - OBJECTIVES: To examine whether an association exists between long-term use of
topical timolol and blood lipids, including high-density lipoprotein cholesterol
(HDL-C), cholesterol, and triglycerides, among participants of the Blue Mountains
Eye Study. METHODS: From 1992 through 1994, a detailed medical and eye
examination was performed in 3,654 people aged 49 years or older, representing
82% of permanent residents in two postcode areas west of Sydney. Glaucoma and
ocular hypertension were diagnosed, and an ophthalmic history was taken,
including use of topical timolol. Fasting blood tests were performed in 89% of
subjects. Lipid levels were compared in subjects using topical timolol for at
least 1 year with those not using timolol, after excluding people using oral beta
blockers, topical beta1-selective agents, or oral lipid-lowering medications.
RESULTS: Analyses compared blood lipids of 63 people who had used topical timolol
for at least 1 year with 2,597 nonusers. No statistically significant differences
were found in any blood lipid mean levels between treated and untreated people,
after multivariate adjustment. However, subgroup analyses of men and women
separately showed that male timolol users had a mean value of HDL-C 0.13 mmol/L
(11%) lower then the mean value of male nonusers, while female timolol users had
a mean value of HDL-C 0.09 mmol/L (5%) higher than the mean for female nonusers.
There were no statistically significant associations between timolol treatment
duration and HDL-C or other lipid levels. Previously reported adverse effects of
oral beta-blockers on blood lipid levels were confirmed. CONCLUSIONS: These
population-based data suggest that long-term administration of topical timolol
for glaucoma or ocular hypertension can cause adverse effects on HDL-C in men,
but not in women. The magnitude of the effect in men was similar to that
previously described in a number of short-term studies.
PMID- 10782629
TI - Effect of latanoprost on intraocular pressure in steroid-induced glaucoma.
AB - PURPOSE: To study the effect of monotherapy with latanoprost 0.005% on
intraocular pressure (IOP) in a prospective nonrandomized clinical trial of
patients newly diagnosed with steroid-induced secondary open-angle glaucoma.
PATIENTS AND METHODS: Eight patients (16 eyes) with newly diagnosed steroid
associated secondary open-angle glaucoma were prescribed latanoprost 0.005% once
a day in each eye. The initial IOP before treatment served as an internal control
for each eye. Intraocular pressure was remeasured after 1 month of monotherapy
with latanoprost. Investigators (WJS) were blinded to initial IOP at the time of
remeasurement. After discontinuation of steroids, IOP was rechecked. If IOP was
stable, latanoprost was discontinued. Intraocular pressure was rechecked 2 to 4
weeks later to confirm an association with steroid use. RESULTS: Intraocular
pressure was significantly decreased after treatment with latanoprost (18.3 +/-
2.8 mm Hg) compared with initial IOP (25.3 +/- 9.1 mm Hg). This change
represented a 28% decrease in IOP compared with baseline levels. Average IOP
after discontinuation of steroids and latanoprost (17.3 +/- 1.4 mm Hg) did not
differ from IOP measured during treatment with latanoprost, but it was
significantly less than the initial IOP before treatment. No adverse effects were
noted. CONCLUSIONS: Monotherapy with latanoprost is safe and effective in
patients with steroid-induced glaucoma. Advantages include lack of systemic side
effects and convenient once-daily dosing.
PMID- 10782630
TI - Additive effect of latanoprost to the combination of timolol and dorzolamide.
AB - PURPOSE: To study the additive effect of latanoprost 0.005% in patients who have
uncontrolled intraocular pressure (IOP) using timolol 0.5% and dorzolamide 2%.
METHODS: Fifty-two consecutive patients with open-angle glaucoma who were using
timolol and dorzolamide and were considered to have IOP above their defined
target pressure were included in this study. After a baseline diurnal tension
curve (DTC) was performed, latanoprost once a day was added to the treatment, and
a second DTC was performed 1 week later. RESULTS: Five patients (9.6%) were
discontinued from treatment because of side effects. The remaining 47 patients
showed a significant IOP reduction of 3.1 mm Hg (16%) from a baseline of 19.3 mm
Hg (mean IOP registered during DTC; P < or = 0.0001). Seventeen patients (36.3%)
showed a mean IOP reduction greater than 20%. CONCLUSIONS: Latanoprost had an
additive effect when used as a third drug for patients on timolol and dorzolamide
who were in need of further IOP reduction. These results suggest that latanoprost
may be very effective in some patients with poorly controlled glaucoma on
multiple therapy.
PMID- 10782632
TI - Glaucoma associated with elevated episcleral venous pressure.
PMID- 10782631
TI - How low can we get? Tonometry in the Thomson gazelle (Gazella thomsoni).
AB - PURPOSE: To establish a normal reference range of intraocular pressure estimates
in Thomson gazelles (Gazella thomsoni). MATERIALS AND METHODS: Applanation
tonometry was conducted in 22 eyes of 11 gazelles anesthetized for transportation
purposes with a mixture of etorphine hydrochloride and acepromazine maleate. Five
sequential readings using a Tono-Pen XL (Mentor Ophthalmics, Inc., Norwell, MA)
were obtained from each eye. Results were analyzed for the effect of age, weight,
gender, side, and replicate readings and were compared with estimates in other
species. RESULTS: Mean (+/- standard deviation) intraocular pressure estimate in
22 eyes of 11 gazelles was 7.6 +/- 1.6 mm Hg. None of the variables tested had a
significant effect on the results. CONCLUSIONS: To date, the intraocular pressure
estimates in the Thomson gazelle are the lowest reported in any species.
PMID- 10782633
TI - Financing new drug development in ophthalmology.
AB - Previously, the author presented an overview of the procedural aspects of
ophthalmic drug development. In that article, aspects of drug discovery and
development were discussed, including application of the scientific method,
compound selection, biological evaluation, pharmaceutical formulation, clinical
development, and regulatory approval. An important part of drug discovery and
development is funding the work. In this article, the author presents key issues
involved in this funding process.
PMID- 10782634
TI - Postoperative Descemet membrane detachment with maintenance of corneal clarity
after trabeculectomy.
AB - This case report describes an unusual complication of Descemet membrane
detachment after anterior chamber reformation to treat a flat anterior chamber
and hypotony from a trabeculectomy. This large Descemet membrane detachment was
unexpectedly associated with a clear cornea. Treatment was conservative, and the
Descemet membrane detachment spontaneously resolved in 6 months.
PMID- 10782635
TI - The relationship between optic disc area and open-angle glaucoma.
PMID- 10782636
TI - Successive approximations for charged particle motion
AB - Single-particle dynamics in electron microscopes, ion or electron lithographic
instruments, particle accelerators, and particle spectrographs is described by
weakly nonlinear ordinary differential equations. Therefore, the linear part of
the equation of motion is usually solved and the nonlinear effects are then found
in successive order by iteration methods. When synchrotron radiation is not
important, the equation can be derived from a Hamiltonian or a Lagrangian. The
Hamiltonian nature can lead to simplified computations of particle transport
through an optical device when a suitable computational method is used. H. Rose
and his school have contributed to these techniques by developing and intensively
using the eikonal method [1-3]. Many ingenious microscopic and lithographic
devices were found by Rose and his group due to the simple structure of this
method [4-6]. The particle optical eikonal method is either derived by
propagating the electron wave or by the principle of Maupertuis for time
independent fields. Maybe because of the time-dependent fields which are often
required, in the area of accelerator physics the eikonal method has never become
popular, although Lagrange methods had been used sometimes already in early days
[7]. In this area classical Hamilitonian dynamics is usually used to compute
nonlinear particle motion. Here the author will therefore derive the eikonal
method from a Hamiltonian quite familiar to the accelerator physics community and
reformulate it in a simplifying way. With the event of high-energy polarized
electron beams [8] and plans for high-energy proton beams [9], nonlinear effects
in spin motion have become important in high-energy accelerators. The author
introduces a successive approximation for the nonlinear effects in the coupled
spin and orbit motion of charged particles which resembles some of the
simplifications resulting from the eikonal method for the pure orbit motion.
PMID- 10782637
TI - Initial resolution measurements of an improved magnetic-electrostatic detector
objective lens for LVSEM
AB - In this paper we present some initial resolution measurements of an improved
magnetic-electrostatic detector objective lens for a low-voltage scanning
electron microscope. The electron optical design of the lens was already proposed
by the authors [G. Knell, E. Plies, Nucl. Instr. & Meth. A 427 (1999) 99]. The
magnetic circuit of this lens has a radially arranged pole-piece gap. Thus, the
specimen is immersed in a strong magnetic field of 106 mT (working distance: 1
mm, primary electron energy: 200 eV). The electrostatic field strength of our
optimized lens variant amounts to a moderate value of 100 V/mm for a working
distance of 1 mm. At a final beam energy of 1 keV a resolution of 3 nm, at 260 eV
a resolution of 5 nm was obtained.
PMID- 10782638
TI - Construction and characterization of the fringe field monochromator for a field
emission gun
AB - Although some microscopes have shown stabilities sufficient to attain below 0.1
eV spectral resolution in high-resolution electron energy loss spectroscopy, the
intrinsic energy width of the high brightness source (0.3-0.6 eV) has been
limiting the resolution. To lower the energy width of the source to 50 meV
without unnecessary loss of brightness, a monochromator has been designed
consisting of a short (4 mm) fringe field Wien filter and a 150 nm energy
selection slit (nanoslit) both to be incorporated in the gun area of the
microscope. A prototype has been built and tested in an ultra-high-vacuum setup
(10(-9) mbar). The monochromator, operating on a Schottky field emission gun,
showed stable and reproducible operation. The nanoslits did not contaminate and
the structure remained stable. By measuring the current through the slit
structure a direct image of the beam in the monochromator could be attained and
the monochromator could be aligned without the use of a microscope. Good
dispersed imaging conditions were found indicating an ultimate resolution of 55
meV. A Mark II fringe field monochromator (FFM) was designed and constructed
compatible with the cold tungsten field emitter of the VG scanning transmission
microscope. The monochromator was incorporated in the gun area of the microscope
at IBM T.J. Watson research center, New York. The monochromator was aligned on
100 kV and the energy distribution measured using the monochromator displayed a
below 50 meV filtering capability. The retarding Wien filter spectrometer was
used to show a 61 meV EELS system resolution. The FFM is shown to be a
monochromator which can be aligned without the use of the electron microscope.
This makes it directly applicable for scanning transmission microscopy and low
voltage scanning electron microscopy, where it can lower the resolution loss
which is caused by chromatic blur of the spot.
PMID- 10782639
TI - Nanosecond electron microscopes
AB - Combining electron optics, fast electronics and pulsed lasers, a transmission and
a photoelectron emission microscope were built, which visualize events in thin
films and on surfaces with a time resolution of several nanoseconds. The high
speed electron microscopy is capable to track fast laser-induced processes in
metals below the ablation threshold, which are difficult to detect by other
imaging techniques. The material response to nano- and femtosecond laser pulses
was found to be very different. It was dominated by thermo/chemocapillary flow
and chemical reactions in the case of nanosecond pulses, and by mechanical
deformations and non-thermal electron emission after a femtosecond pulse.
PMID- 10782640
TI - Measurement of lens aberrations by means of image displacements in beam-tilt
series
AB - Electron microscope image aberrations are determined by means of the beam
tilt/image displacement method with respect to the precision required to obtain a
resolution of 1 A. The method simultaneously yields all image aberrations to the
fourth order and it is independent of the material used for the procedure. The
experimental procedure using amorphous carbon is described and errors in
measuring beam-tilt angles, magnifications and image displacements can be kept
sufficiently small to achieve the required accuracy. The method is applied to
determine aberration constants of a CM300 FEG/UT microscope with correction of
the three-fold astigmatism. The coefficient of spherical aberration and the
modulus of the three-fold astigmatism were measured to 0.60 (+/- 0.02) mm and 150
(+/- 50) nm, respectively. The beam tilt/image displacement procedure is also
computer simulated using an amorphous model structure yielding the same values
for the lens aberrations which are used for imaging. However, a coefficient of
spherical aberration of 0.67 mm is obtained by applying the focus
variation/diffractogram analysis on the same model.
PMID- 10782641
TI - Upper limits for the residual aberrations of a high-resolution aberration
corrected STEM
AB - The development of correctors for electron optical systems has already brought
the improvement of resolution for a low-voltage scanning electron microscope and
a commercially available transmission electron microscope and is anticipated in
the near future for a dedicated scanning transmission electron microscope (STEM).
The resolution attainable especially of a probe-forming system at 200 kV cannot
only be estimated from calculations ignoring all non-rotationally symmetric axial
aberrations in an electron optical system. For a certain resolution, one would
like to attain, the influence of the deviations from the ideal, aberration-free
system has to be investigated. Therefore, in the following we have carried out
the evaluation of the required accuracy for the compensation of the various
residual aberrations in order to achieve a resolution in the sub-Angstrom regime
with a probe-forming system.
PMID- 10782642
TI - Inelastic electron holography
AB - Coherence of inelastically scattered electrons was investigated by means of
biprism interference experiments performed in a transmission electron microscope
equipped with a highly coherent field emission gun and an imaging filter. The
experimental results show that within the wave inelastically scattered at
aluminium plasmons there is in fact an area of about 10 nm diameter with
coherence sufficient to take electron holograms.
PMID- 10782643
TI - Inelastic scattering and holography
AB - The controversy about whether or not an inelastically scattered electron wave can
still interfere with a reference wave is solved by treating the whole problem
rigorously and describing electron, source and object in one Hamiltonian. It
turns out that, in principle, interference can occur between an inelastically
scattered wave and a reference wave from the incident beam spectrum provided the
energy difference is smaller than about 10(-15) eV. However, it is argued that
the density of states in source object and electron wave is much too small to
make this effect observable.
PMID- 10782644
TI - Can high-angle annular dark field scattering be represented by a local operator?
AB - High-angle annular dark field imaging has become an invaluable technique for
recording atomic resolution STEM images. Many analyses of high-angle annular dark
field images assume that the signal is the result of a local scattering operator
and can be represented as a simple convolution of a probe function with a set of
atomic columns. The apparent simplicity of the technique and the straightforward
increase in signal with atomic number have lead to the belief that it is possible
to quantify impurity concentrations at atomic column resolution. The limitations
in these assumptions are examined on the basis of approximations starting from a
complete theory for high-angle scattering based on multi phonon excitations. Not
surprisingly, the accuracy of the local scattering operator approximation
improves as the inner cut-off angle is increased.
PMID- 10782645
TI - Zero-loss image formation and modified contrast transfer theory in EFTEM.
AB - For a weak phase/weak amplitude object the information transfer in the imaging
process of TEM is described by the common formalism of the contrast transfer
function (CTF). So far the effects of inelastic scattering were not accounted for
in this formalism. In conventional imaging they were simply neglected. In energy
filtering TEM (EFTEM), where removal of inelastic electrons leads to higher
specimen contrast, they were modelled by a global increase of the elastic
amplitude contrast. Thus, the description of inelastic and elastic scattering was
mixed. Here a new ansatz is proposed which treats elastic and inelastic contrast
transfer separately by adding an inelastic contribution to the scattering
potentials. In EFTEM this has the effect of adding a filter contrast which
depends on the characteristics of the inelastic scattering. For samples with
dominant plasmon loss the additional filter contrast is restricted to low
resolution. Because of its strong dependence on the nature of the inelastic
scattering process, the filter contrast cannot in general be unified with the
conventional elastic amplitude contrast. The modified CTF theory for EFTEM was
tested experimentally on a variety of samples. Images of amorphous layers of
copper, aluminium, and carbon films, as well as zero-loss images of proteins
embedded in amorphous ice were evaluated. The values of the parameters of the
additional filter contrast were determined for carbon film and proteins embedded
in vitrified ice. Comparison of different CTF models used to reconstruct 3D
volumes from zero-loss images confirmed that best agreement with the atomic model
is attained with the new, modified CTF theory.
PMID- 10782646
TI - Computation of contrasts in atomic resolution electron spectroscopic images of
planar defects in crystalline specimens
AB - The image obtained in a conventional transmission electron microscope contains
contributions from elastically and from inelastically scattered electrons. The
electron spectroscopic imaging mode of an energy-filtering transmission electron
microscope allows us to separate these two different contributions by inserting
an energy-selecting slit in the energy-dispersive plane of an imaging energy
filter. Selecting a specific energy loss corresponding to the ionization of the
inner shell of a particular element one can obtain information on the
distribution of the element within the specimen. The contrast is then caused by
inelastically scattered electrons. For crystalline specimens, however, the
contrast will be influenced additionally by the elastic contrast. This elastic
contrast arises from electron diffraction and increases with increasing crystal
thickness. Therefore the intensity distribution in the image cannot directly be
interpreted as an elemental map. For a reliable interpretation of contrast
formation in elemental maps it is therefore necessary to compute theoretical
energy-loss images for various crystal thicknesses and compare these images with
the experimental images. As an example we discuss the influence of electron
diffraction effects on energy-loss images of two crystals with planar defects.
Linescans are computed for various thicknesses of these crystals. Our
calculations are performed using first-order perturbation theory to describe the
transitions between the Bloch-wave states of the incident electron. The computed
linescans for various crystal thicknesses show clearly that the influence of the
elastic contrast on an image increases when we investigate thicker specimens.
Furthermore, the comparison between elastic and energy-loss images demonstrates
the partial preservation of the elastic contrast as a function of thickness. We
find that for specimens thicker than about one third of the extinction length
(here approximately 80-100 A) it is impossible to interpret an energy-loss image
directly as elemental map.
PMID- 10782647
TI - Surface structural sensitivity of convergent-beam RHEED: Si (0 0 1) 2 x 1 models
compared with dynamical simulations
AB - The aim of this work is to evaluate the sensitivity of convergent-beam RHEED for
the refinement of surface atomic structure. We have compared experimental and
theoretical convergent-beam RHEED patterns from the silicon (0 0 1) reconstructed
surface. The experiment was carried out in a custom designed UHV diffraction
camera,using a micron sized probe. Both experimental and theoretical CB-RHEED
patterns show complex details, highly sensitive to the surface structure. The
multiple scattering simulations were based on two experimental structural models
which make different assumptions for dimer tilt, one derived from X-ray
diffraction results, and another from LEED data. The simulated CB-RHEED patterns
using the X-ray model were found to be in closer agreement with our experiment
than the LEED model. However, the agreement is not entirely satisfactory,
suggesting that further improvement on this model is necessary.
PMID- 10782648
TI - Analysis of local strain in aluminium interconnects by energy filtered CBED
AB - Energy filtered convergent beam electron diffraction (CBED) was used to
investigate localised strain in aluminium interconnects. The quantitative
analysis of the experimental patterns is based on a multi-step evaluation
procedure which is the main subject of the present paper. The improvements which
were made to the analysis method aim at increasing both the automation and the
accuracy. The detection of the higher order Laue zone (HOLZ) line positions is
performed by means of the Hough transform. The required sub-pixel resolution can
be achieved routinely and the achievable accuracy is only limited by the line
width and the amount of noise in the patterns. The determination of the strain
state is performed via a refinement algorithm which is based on varying the
strain state in the sample coordinate system and simulating the patterns for the
individual grains until a best fit with the experiment is obtained. For the
simulation we have developed a new correction scheme in which the dynamical
effects are treated separately for each individual HOLZ line. The results show
that the main source of the observed strains is the difference in thermal
expansion coefficients. The strain is substantially reduced underneath a hillock
in the interconnect. Asymmetries in the strain distribution around the hillock
show that the unidirectional diffusion during electromigration tests causes peak
strains in areas next to the hillock which may be possible failure sites.
PMID- 10782650
TI - Investigation of thermoelectric silicide thin films by means of analytical
transmission electron microscopy
AB - The microstructure of rhenium silicide thin films and its progress by annealing
were investigated by means of analytical transmission electron microscopy.
Sputtered amorphous films were characterised by analysis of the radial
distribution function (RDF). The position of the first maximum of RDF represents
the most probable distance between neighbouring atoms and decreases from 2.75 to
2.62 A in films with an increasing Si-content from 60 to 75 at%. This decrease
correlates with the change of the temperature coefficient (TC) of the electrical
resistivity. During in situ annealing, the formation of nanocrystals in films
with different Si-contents was observed. In thin films with 64 at% the quantity
of nanocrystals increases after 1 h at 900 K whereas their sizes remain
unchanged. The crystallisation in Re-rich thin films proceeds lower and produces
larger crystals than in films near to the ReSi1.75 stoichiometry. Sputtered
epitaxial ReSi1.75 films on Si (1 0 0) consist of crystals with nanometer size
and an azimuthal torsion of 45 degrees.
PMID- 10782649
TI - Rietveld analysis of electron powder diffraction data from nanocrystalline
anatase, TiO2
AB - The structure of nanocrystalline anatase (TiO2) was successfully refined from
electron powder diffraction data using the Rietveld technique. A polycrystalline
sample (average crystal size about 70 A) was characterised by selected area
electron diffraction in a conventional transmission electron microscope operated
at 300 kV. Radially integrated intensities were extracted from digitised
photographic films and used in the course of structure refinements by a standard
program for Rietveld analysis. The structure was refined in space group I4(1)/amd
(#141) with lattice parameters a = 3.7710(9) A and c = 9.430(2) A. The
reliability factors of the refinement are Rwp = 5.2% and R(B) = 2.6%. The close
agreement of the refined structural parameters with previous results obtained
from neutron diffraction on coarse-grained powders proves the applicability of
the method for characterising nanocrystalline powders. The present study shows
that Rietveld analysis on electron powder data is a good compliment to the
existing methods for accurate structural investigations on nanocrystalline
materials and thin films.
PMID- 10782651
TI - TEM analysis of epitaxial semiconductor layers with high stacking fault densities
considering artifacts induced by the cross-section geometry
AB - Epitaxial semiconductor layers, in particular II-VI compound semiconductors with
the component Se deposited on III-V semiconductor substrates like GaAs or InAs,
can contain high densities of stacking faults. CdxMg(1-x)Se layers with Cd
concentrations x of 93% and 57% on InAs(0 0 1) substrates were investigated as
typical representatives of this class of heterostructures. The defect structure
of the layers is dominated by a high density of stacking fault (SF) pairs bound
by Shockley partial dislocations with Burgers vectors b = 1/6 <1 1 2> and a stair
rod dislocation with b = 1/6 <1 1 0> at the intersection line of the pairs. Plan
view transmission electron microscopy (TEM) is generally applied to obtain
information about the type, density and arrangement of the stacking faults in
thin epilayers up to moderate SF densities. Cross-section TEM is more frequently
carried out for thick layers and at high SF densities. It will be demonstrated by
a detailed analysis of cross-section images that a careful interpretation of the
observed SF morphologies is necessary due to artifacts induced by the cross
section geometry.
PMID- 10782652
TI - Electron microscope characterization of CdSe/ZnSe quantum dots based on molecular
dynamics structure relaxations
AB - Molecular dynamics simulations using empirical potentials are applied to
characterize the structure, the energy relaxation and the stability of pyramidal
shaped quantum dots in the CdSe/ZnSe system. The relaxed structure models are
used for a reliable interpretation of electron microscope investigations to
analyze the size, the shape and the strain fields of the quantum dots. Though the
elastic strains modify the electron microsope image contrast by creating virtual
truncations of the pyramids or additional black-white lobes, optimum imaging
conditions chosen will reveal the shape and the size of the dots.
PMID- 10782654
TI - Ammunition from the cancer wars: live and spent bullets.
PMID- 10782653
TI - Effects of supplemental alpha-tocopherol and beta-carotene on colorectal cancer:
results from a controlled trial (Finland)
AB - BACKGROUND: Some epidemiological investigations suggest that higher intake or
biochemical status of vitamin E and beta-carotene might be associated with
reduced risk of colorectal cancer. METHODS: We tested the effects of alpha
tocopherol and beta-carotene supplementation on the incidence of colorectal
cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a
double-blind, placebo-controlled trial among 29,133 50-69-year-old male cigarette
smokers. Participants were randomly assigned to receive alpha-tocopherol (50 mg),
beta-carotene (20 mg), both agents, or a placebo daily for 5-8 years. Incident
colorectal cancers (n = 135) were identified through the nationwide cancer
registry, and 99% were histologically confirmed. Intervention effects were
evaluated using survival analysis and proportional hazards models. RESULTS:
Colorectal cancer incidence was somewhat lower in the alpha-tocopherol arm
compared to the no alpha-tocopherol arm, but this finding was not statistically
significant (relative risk (RR) = 0.78, 95% confidence interval (CI) 0.55-1.09;
log-rank test p = 0.15). Beta-carotene had no effect on colorectal cancer
incidence (RR = 1.05, 95% CI 0.75-1.47; log-rank test p = 0.78). There was no
interaction between the two substances. CONCLUSION: Our study found no evidence
of a beneficial or harmful effect for beta-carotene in colorectal cancer in older
male smokers, but does provide suggestive evidence that vitamin E supplementation
may have had a modest preventive effect. The latter finding is in accord with
previous research linking higher vitamin E status to reduced colorectal cancer
risk.
PMID- 10782655
TI - Passive and active smoking and breast cancer risk in Canada, 1994-97.
AB - BACKGROUND: Studies comparing ever smokers with never smokers have found little
increase in breast cancer risk. However, the five published studies examining
passive smoking and breast cancer have all suggested associations with both
passive and active smoking, particularly premenopausal risk. METHODS: We analyzed
data collected through the Canadian National Enhanced Cancer Surveillance System,
from 805 premenopausal and 1512 postmenopausal women with newly diagnosed
(incident), histologically confirmed, primary breast cancer and 2438 population
controls. The mailed questionnaire included questions on breast cancer risk
factors and a lifetime residential and occupational history of exposure to
passive smoking. RESULTS: Among premenopausal women who were never active
smokers, regular exposure to passive smoke was associated with an adjusted breast
cancer odds ratio (OR) of 2.3 (95% confidence interval [CI] 1.2-4.6). Passive
exposure showed a strong dose-response trend (test for trend p = 0.0007) with an
OR of 2.9 (95% CI 1.3-6.6) for more than 35 years of passive residential and/or
occupational exposure. When premenopausal women who had ever actively smoked were
compared with women never regularly exposed to passive or active smoke, the
adjusted OR for breast cancer was also 2.3 (95% CI 1.2-4.5). Among postmenopausal
women who were never-active smokers, regular exposure to passive smoke was
associated with an adjusted breast cancer OR of 1.2 (95% CI 0.8-1.8) and an OR of
1.4 (95% CI 0.9-2.3) for the most highly exposed quartile of women. The adjusted
OR for postmenopausal breast cancer risk for ever-active smokers compared with
women never regularly exposed to passive or active smoke was 1.5 (95% CI 1.0
2.3). Statistically significant dose-response relationships were observed with
increasing years of smoking, increasing pack-years and decreasing years since
quitting. Women with 35 or more years of smoking had an adjusted OR of 1.7 (95%
CI 1.1-2.7). CONCLUSIONS: Active and passive smoking may be associated with
increased breast cancer risk, particularly premenopausal risk.
PMID- 10782656
TI - Effects of social support, regular physician and health-related attitudes on
cervical cancer screening in an Asian population.
AB - OBJECTIVE: Out primary objective was to examine sociodemographic and attitudinal
factors that affect uptake of the Pap smear in a multi-ethnic Asian population.
METHODS: We conducted a prevalence survey among women aged 50-64 years living in
Singapore and ascertained by means of an in-person questionnaire interview their
Pap screening history, demographic characteristics, informal social support and
attitudes towards early detection. RESULTS: We found that, after adjusting for
demographic variables known to be predictors of Pap screening, women who reported
ever having a Pap smear were more likely to have close friends with whom they
could discuss health (adjusted odds ratio (OR) 2.1, 95% confidence intervals (CI)
1.2-3.6), and have a regular physician (adjusted OR 2.3 (1.3-4.1)). Based on
responses to four indices measuring health attitudes, they were significantly
less likely to express a fatalistic viewpoint towards health and illness
(adjusted OR for highest vs. lowest tertile 0.3 (95% CI 0.1-0.7)), and more
likely to believe that early detection could improve the outcome (adjusted OR 3.3
(95% CI 1.4-7.8)). The nature of the test itself was a significant barrier to
having a Pap smear, but only among women with fewer years of education.
CONCLUSIONS: Our results suggest that, within this Asian population, a multi
pronged approach is required to reach unscreened women. The role of physicians
and close friends should be emphasized, and health messages should be formulated
to address specific, relevant attitudinal barriers to Pap screening.
PMID- 10782658
TI - Alcohol consumption and risk of breast cancer: a cohort study.
AB - OBJECTIVES: To study the association between alcohol consumption and breast
cancer risk. METHODS: A case-cohort analysis was undertaken within the cohort of
56,837 women who were enrolled in the Canadian National Breast Screening Study
(NBSS) and who completed a self-administered dietary questionnaire. (The NBSS is
a randomized controlled trial of screening for breast cancer in women aged 40-59
at recruitment.) The cohort was recruited between 1980 and 1985, and during
follow-up to the end of 1993 a total of 1469 women in the dietary cohort were
diagnosed with biopsy-confirmed incident breast cancer. For comparative purposes
a subcohort consisting of a random sample of 5681 women was selected from the
full dietary cohort. After exclusions for various reasons the analyses were based
on 1336 cases and 5238 noncases. RESULTS: When compared to nondrinkers the
adjusted incidence rate ratios (95% confidence intervals) for those consuming > 0
and < or = 10 g of alcohol/day, > 10 and < or = 20 g/day, > 20 and < or = 30
g/day, > 30 and < or = 40 g/day, > 40 and < or = 50 g/day, and > 50 g/day were
1.01 (0.84-1.22), 1.16 (0.91-1.47), 1.27 (0.91-1.78), 0.77 (0.51-1.16), 1.00
(0.57-1.75), and 1.70 (0.97-2.98), respectively; the associated p value for the
test for trend was 0.351. Similar findings were obtained when analyses were
conducted separately in the screened and control arms of the NBSS, in
premenopausal and postmenopausal women, for screen-detected and interval-detected
breast cancer, and by levels of other breast cancer risk factors. CONCLUSIONS:
The results of this study suggest that alcohol consumption might be associated
with increased risk of breast cancer at relatively high levels of intake.
PMID- 10782657
TI - Gastroesophageal reflux disease, use of H2 receptor antagonists, and risk of
esophageal and gastric cancer.
AB - OBJECTIVE: The incidence of esophageal adenocarcinoma has risen rapidly in the
past two decades, for unknown reasons. The goal of this analysis was to determine
whether gastroesophageal reflux disease (GERD) or the medications used to treat
it are associated with an increased risk of esophageal or gastric cancer, using
data from a large population-based case-control study. METHODS: Cases were aged
30-79 years, newly diagnosed with esophageal adenocarcinoma (n = 293), esophageal
squamous cell carcinoma (n = 221), gastric cardia adenocarcinoma (n = 261), or
non-cardia gastric adenocarcinoma (n = 368) in three areas with population-based
tumor registries. Controls (n = 695) were chosen by random digit dialing and from
Health Care Financing Administration rosters. Data were collected using an in
person structured interview. RESULTS: History of gastric ulcer was associated
with an increased risk of non-cardia gastric adenocarcinoma (OR 2.1, 95% CI 1.4
3.2). Risk of esophageal adenocarcinoma increased with frequency of GERD
symptoms; the odds ratio in those reporting daily symptoms was 5.5 (95% CI 3.2
9.3). Ever having used H2 blockers was unassociated with esophageal
adenocarcinoma risk (OR 0.9, 95% CI 0.5-1.5). The odds ratio was 1.3 (95% CI 0.6
2.8) in long-term (4 or more years) users, but increased to 2.1 (95% CI 0.8-5.6)
when use in the 5 years prior to the interview was disregarded. Risk was also
modestly increased among users of antacids. Neither GERD symptoms nor use of H2
blockers or antacids was associated with risk of the other three tumor types.
CONCLUSIONS: Individuals with long-standing GERD are at increased risk of
esophageal adenocarcinoma, whether or not the symptoms are treated with H2
blockers or antacids.
PMID- 10782659
TI - NSAIDs and risk of colorectal cancer according to presence or absence of family
history of the disease.
AB - BACKGROUND: We undertook the present analyses to determine whether family history
of colorectal cancer in a parent or sibling modifies the inverse association of
nonsteroidal anti-inflammatory drug (NSAID) use with colorectal cancer risk.
METHODS: We used data from two case-control studies of colorectal cancer. The
hospital-based Case Control Surveillance Study included 1526 patients with
primary colorectal cancer, 4192 cancer controls and 6036 noncancer controls. A
population-based study conducted in Massachusetts enrolled 1201 incident cases of
colorectal cancer and 1201 community controls. Data on NSAID use and risk factors
for colorectal cancer were collected by interview. RESULTS: In both studies there
was a reduction in the odds ratios among subjects who used NSAIDs regularly
continuing into the previous year, regardless of family history. In the Case
Control Surveillance data, the odds ratio was 0.4 (95% CI 0.2-0.9) among subjects
with a family history and 0.5 (95% CI 0.4-0.7) among subjects without a family
history. The comparable odds ratios in the Massachusetts data were 0.5 (95% CI
0.3-0.9) and 0.7 (95% CI 0.6-0.9). CONCLUSIONS: These data indicate that regular
continuing NSAID use is associated with a reduced risk of colorectal cancer among
persons with a family history of the disease, as well as those without such a
history.
PMID- 10782660
TI - Cancer control research 2001.
AB - OBJECTIVES: Major societal changes, including the changing demographics of US
society and the genetics and communications revolutions, are providing new
opportunities to control cancer both in the United States and around the world.
This article examines the implications of these trends and other issues in the
context of cancer control research. A seven-item strategy for cancer control
research is proposed. RESULTS: Epidemiology, statistics, genetics, and bio
behavioral research are central disciplines for cancer control research. The
identification of particular at-risk populations is increasingly possible. Cancer
control research must focus on increasing fundamental knowledge in order to
accelerate improvements in cancer prevention and early detection. Cancer control
research also must be used to conduct trials of new cancer detection methods,
overcome differential participation in cancer screening, develop evidence-based
strategies to improve decision-making, and develop evidence-based cancer
communications. A comprehensive cancer surveillance system is the foundation for
cancer control research. Cancer control research must aim to reduce cancer risk,
incidence, and mortality, and improve quality of life. These are important
challenges for the new millennium.
PMID- 10782661
TI - The associations of adolescent cigarette smoking, alcoholic beverage consumption,
environmental tobacco smoke, and ionizing radiation with subsequent breast cancer
risk (United States).
AB - OBJECTIVES: Studies of breast cancer among survivors of the World War II atomic
bomb blasts over Japan suggest that the adolescent breast may be particularly
sensitive to carcinogenic insult. To further explore that possibility we examined
the relationships of cigarette smoking, alcohol consumption, environmental
tobacco smoke (ETS) exposure, and medical treatment with ionizing radiation
during adolescence with subsequent breast cancer risk. METHODS: Data from the
Carolina Breast Cancer Study, a population-based, case-control study of breast
cancer in North Carolina women aged 20-74 years (864 cases, 790 controls), were
analyzed. RESULTS: A modest increase in breast cancer risk was suggested for
women who began to smoke cigarettes between the ages of 10 and 14 years (OR: 1.5,
CI: 0.9-2.5), and for women exposed to ionizing radiation between ages 10 and 19
years to treat or monitor a medical condition (OR: 1.6, CI: 0.5-2.5). Neither
exposure to ETS at home prior to age 18 years (OR: 1.1, CI: 0.9-1.3) nor
initiation of alcoholic beverage consumption between ages 10 and 15 years (OR:
1.1, CI: 0.6-1.8) appeared to increase risk. CONCLUSIONS: Our results are
consistent with previous evidence suggesting that some adolescent exposures could
influence future breast cancer risk.
PMID- 10782663
TI - Update: master settlement agreement between the states and the tobacco industry
(United States).
PMID- 10782662
TI - A prospective study of plasma ascorbic acid concentrations and breast cancer
(United States).
AB - OBJECTIVES: To investigate the association between prediagnostic plasma ascorbic
acid concentrations and subsequent breast cancer risk in a nested case-control
study. METHODS: Female volunteer residents of Washington County, MD, donated
14,625 non-fasting blood samples in 1989. Incident breast cancer cases (n = 115)
and controls (n = 115) were matched by age, menopausal status at donation, and
date and hour of blood donation. RESULTS: Median ascorbic acid concentrations
were similar between cases and controls (1.44 mg/dl vs. 1.39 mg/dl. p = 0.78).
There was no evidence for a dose-response relationship between higher plasma
ascorbic acid concentrations and breast cancer risk [highest vs. lowest fifths:
ORadjusted = 0.90, Ptrend = 0.98). CONCLUSIONS: Findings from this prospective
study do not suggest a protective association between prediagnostic plasma
ascorbic acid concentrations and breast cancer risk in the subsequent 5 years of
follow-up.
PMID- 10782665
TI - Solid-phase synthesis of oligomeric deoxynucleic-thiourea (DNT) and deoxynucleic
S-methylthiourea (DNmt): a neutral/polycationic analogue of DNA.
AB - A solid-phase synthesis for oligomeric DNmt is reported. Synthesis proceeds in 3'
5' direction and involves coupling of a protected 3'-isothiocyanate with the
corresponding 5'-amine of the growing oligo chain. The difference in oligomeric
thiourea/S-methylthiourea binding to DNA is investigated.
PMID- 10782664
TI - Isoxazolines and isoxazoles as factor Xa inhibitors.
AB - 3,4,5-Trisubstituted isoxazolines (2) and isoxazoles (3) were prepared and
evaluated for their in vitro and in vivo antithrombotic efficacy. They were
compared to 3,5,5-trisubstituted isoxazolines (1) for Factor Xa selectivity and
potency. They were also compared in an arterio-venous (A-V) shunt model of
thrombosis.
PMID- 10782666
TI - The synthesis and vasopressin (AVP) antagonist activity of a novel series of N
aroyl-2,4,5,6-tetrahydropyrazolo[3,4-d]thieno[3,2-b]azepines.
AB - Synthesis and SAR of N-[4-[(4,5-dihydropyrazolo[3,4-d]thieno[3,2-b]azepin-6(2H)-y
l)carbonyl]phenyl]benzamides as arginine vasopressin (AVP) receptor antagonists
are discussed. Potent orally active AVP receptor antagonists are produced when
the benzamide moiety contains a phenyl group at the 2-position. Similar analogues
of 4,6,7,8-tetrahydro-5H-thieno[3,2-b]azepine and VPA-985 are reported.
PMID- 10782667
TI - Antitumor agents. Part 202: novel 2'-amino chalcones: design, synthesis and
biological evaluation.
AB - New 4',5',2,3,4-substituted 2'-amino chalcones were synthesized and evaluated for
cytotoxicity against a panel of human tumor cell lines. Several compounds
displayed significant cytotoxicity. The most promising lead molecule (10) also
had high activity toward multi-drug resistant KB-VIN, and ovarian 1A9 cell lines.
2'-Amino chalcones demonstrated significantly increased antitumor activity
compared with the corresponding chalcones, while, the epoxide derivatives
generally showed greatly reduced activity.
PMID- 10782668
TI - Suitably functionalised pyrimidines as potential antimycotic agents.
AB - Various suitably functionalized pyrimidine derivatives have been synthesized to
explore their potential as antimycotic agents. Some of the synthesized compounds
4c, 4d, 8a-e have shown highly significant in vitro antifungal activity against
five human pathogenic fungi.
PMID- 10782669
TI - Synthesis and biological activity of fluoro-substituted pyrrolo[2,3
d]pyrimidines: the development of potential positron emission tomography imaging
agents for the corticotropin-releasing hormone type 1 receptor.
AB - A series of fluoro-substituted 4-(dialkylamino)pyrrolo[2,3-d]pyrimidines was
synthesized and their binding affinity for corticotropin-releasing hormone type 1
receptor (CRHR1) was investigated. Compounds 11a and 11b possessed very high
CRHR1 affinity (Ki=3.5, 0.91 nM, respectively). They are promising candidates for
the development of 18F-containing nonpeptide PET radioligands for CRHR1.
PMID- 10782670
TI - Alpha-ketoamides, alpha-ketoesters and alpha-diketones as HCV NS3 protease
inhibitors.
AB - Peptide-based alpha-ketoamides, alpha-ketoesters and alpha-diketones were
designed, synthesized and evaluated against HCV NS3 protease. Alpha-ketoamides
have the highest affinity among the three classes, with 8 being the most potent
inhibitor with an IC50 of 340 nM.
PMID- 10782671
TI - 4-Thiazolidinones: novel inhibitors of the bacterial enzyme MurB.
AB - 4-Thiazolidinones were synthesized and evaluated for their ability to inhibit the
bacterial enzyme MurB. Selected 4-thiazolidinones displayed activity against the
enzyme in vitro. This activity, coupled with the design principles of the
thiazolidinones, supports the postulate that 4-thiazolidinones may be recognized
as diphosphate mimics by a biological selector.
PMID- 10782672
TI - Heterocyclic bibenzimidazole derivatives as topoisomerase I inhibitors.
AB - A series of 2'-heterocyclic derivatives of 5-phenyl-2,5'-1H-bibenzimidazoles were
evaluated for topoisomerase I poisoning activity and cytotoxicity. Topo I
poisoning activity was associated with 2'-derivatives that possessed a hydrogen
atom capable of hydrogen bond formation, suggesting that the interatomic
distances between such hydrogen atoms and the heteroatoms on the adjacent
benzimidazole influence activity.
PMID- 10782673
TI - N-acyl phenylalanine analogues as potent small molecule VLA-4 antagonists.
AB - We have identified a series of low molecular weight (Mr < 500) N
acylphenylalanines that are effective inhibitors of the VCAM-VLA-4 interaction.
Investigation of the SAR of the N-acyl moiety led to the identification of N
benzylpyroglutamyl derivatives as being particularly potent.
PMID- 10782674
TI - N-benzylpyroglutamyl-L-phenylalanine derivatives as VCAM/VLA-4 antagonists.
AB - A series of N-(N-benzylpyroglutamyl)-4-substituted-L-phenylalanine derivatives
was prepared as VLA-4/VCAM antagonists. Analogues substituted by electron
deficient benzoylamino groups bearing bulky ortho substituents had low-nM potency
in an ELISA assay and low-microM activity in a cell based assay.
PMID- 10782675
TI - High incorporation of L-amino acids to cereulide, an emetic toxin from Bacillus
cereus.
AB - Cereulide is a principal toxin causing emetic syndrome produced by Bacillus
cereus. This paper deals with biosynthetic studies on this unusual cyclic
depsipeptide toxin from 13C labeled L-amino acid precursors (Val, Leu, Ala) upon
cultivation in synthetic media. The analyses were made at atomic level of the
constituent amino- or oxy-acids through NMR and ESI-MS/MS spectroscopic methods
on cereulide and its hydrolysate dipeptides. The incorporation of the 13C atom
was 95% in each O-Val, O-Leu and L-Val, while 40% in D-Ala of cereulide.
PMID- 10782676
TI - Cyclodextrin-peptide hybrid as a hydrolytic catalyst having multiple functional
groups.
AB - A designed cyclodextrin peptide hybrid, which has multiple functional groups on
its alpha-helix peptide backbone, has been synthesized as a catalyst for ester
hydrolysis. Kinetic study revealed that the carboxylate group plays a key role in
this system.
PMID- 10782677
TI - Guanylpiperidine peptidomimetics: potent and selective bis-cation inhibitors of
factor Xa.
AB - A novel series of rigid P3-guanylpiperidine peptide mimics 3-14 was designed as
potential factor Xa and prothrombinase inhibitors. Incorporation into a P2-gly-P1
argininal motif led to highly potent and selective inhibitors. The synthesis and
biological activities of these derivatives are reported herein.
PMID- 10782679
TI - Structural comparison between type I and type II antagonists: possible
implications in the drug design of AT1 antagonists.
AB - Analogues of sarilesin (type I AT1 antagonists), and sarmesin (type II AT1
antagonists) with homoserine (hSer) at position 8 were prepared and bioassayed.
The presence of a Tyr4-Ile5-His6 bend found in sarmesin but not in sarilesin was
identified. The obtained results coupled with conformational analysis studies,
using a combination of NMR spectroscopy and computational chemistry, propose
important conformational and stereoelectronic properties for agonist and
antagonist activity at AT1 receptors.
PMID- 10782678
TI - Conversion of a polysaccharide to nitric oxide-releasing form. Dual-mechanism
anticoagulant activity of diazeniumdiolated heparin.
AB - We describe heparin/diazeniumdiolate conjugates that generate nitric oxide (NO)
at physiological pH. Like the heparin from which they were prepared, they inhibit
thrombin-induced blood coagulation. Unlike heparin, they can also inhibit and
reverse ADP-induced platelet aggregation (as expected for an NO-releasing agent),
suggesting potential utility as dual-action antithrombotics.
PMID- 10782680
TI - Macrocarpins A-D, new cytotoxic nor-triterpenes from Maytenus macrocarpa.
AB - Macrocarpins A (1), B (2), C (3) and D (4), four new nor-triterpenes, have been
isolated from the roots of Maytenus macrocarpa. The structures were established
by spectroscopic examinations. Natural compounds 1, 2, 4 and the acetyl
derivative 1a are cytotoxic against four tumoral cell lines with IC50 values
ranging between 0.4 and 5.2 microM.
PMID- 10782681
TI - The abasic site as a target for generation of locally multiply damaged sites.
AB - Abasic sites in DNA have been specifically targeted by synthetic compounds able
to cleave DNA at abasic sites and to induce photodamages in the vicinity of the
lesion. The synthesis and the photoactivity of the drugs on abasic sites
containing DNA and oligonucleotides are reported.
PMID- 10782682
TI - QSAR of 1,1'-(1,2-ethylenebisbenzyl)bis(4-substitutedpyridinium) dibromides as
choline kinase inhibitors: a different approach for antiproliferative drug
design.
AB - Ten new structures of a series of the title compounds were synthesized and
screened for their activity to inhibit choline kinase under ex vivo conditions.
Their inhibitory potency correlates with the 13C chemical shifts (in CD3OD) of
the methylene group bearing the positively charged nitrogen. The inhibitory
effect on proliferation against the HT-29 cell line is strongly dependent on its
ability to inhibit the production of phosphorylcholine.
PMID- 10782683
TI - Synthesis and pharmacology of new enantiopure delta(3)-4-arylkainoids.
AB - Seven delta(3)-4-arylkainoids possessing various 4-position aromatic and
heteroaromatic groups were synthesized and their apparent affinities were
measured in order to explore the influences of 4-position electron density and
stereochemistry on receptor affinity and specificity. Kainoids 1a-f were shown to
be selective agonists at the NMDA receptor and the electron rich furanyl and
thienyl analogues exhibited the highest affinities. Naphthylkainoid 1g proved to
be a nonselective antagonist at the iGluRs.
PMID- 10782684
TI - Serendipitous synthesis of novel dehydro- and dechloro-pseudomycin B (PSB)
derivatives.
AB - The syntheses and preliminary investigation of antifungal activities of two
dehydro PSB derivatives 8 and 10 as well as one 3-imido-9-dechloro PSB analogue
13 are described.
PMID- 10782685
TI - Synthesis of a cyanopeptide-analogue with trypsin activating properties.
AB - An efficient synthesis of a peptidic analogue of cyanobacterial metabolites with
proposed serine protease inhibitory activity has been developed. Surprisingly,
one trypsin activating compound was obtained.
PMID- 10782687
TI - Synthesis and transfection properties of novel non-toxic monocationic lipids.
Variation of lipid anchor, spacer and head group structure.
AB - This report describes the synthesis and the transfection properties of novel
monocationic non-toxic lipids. We have carried out structural variations in all
three units of the transfection lipid, the lipid anchor, the spacer moiety and
the positively charged head group. Our results lead to the conclusion that
systematic modification of structural subunits is a promising way to enhance the
transfection efficiency.
PMID- 10782686
TI - The design, synthesis and physical chemical properties of novel human vasopressin
V2-receptor antagonists optimized for parenteral delivery.
AB - Ionizable groups were introduced onto the 10,11-dihydro-5H-pyrrolo[2,1
c][1,4]benzodiazepine scaffold of the vasopressin V2-antagonist WAY-VPA-985 in
the search for molecules optimized for parenteral formulation. The synthesis and
structure activity relationships (SAR) are presented together with solubility
data in a model parenteral system. The amine, WAY-140288 (4f), was chosen for
further development. p6
PMID- 10782688
TI - N-p-nitrobenzyloxycarbonyl galactosamine imidate as a glycosyl donor for the
efficient synthesis of mucin core-2 analogue.
AB - An efficient synthesis of the mucin core-2 analogue 1a was accomplished using N-p
nitrobenzyloxycarbonyl(PNZ)-protected trichloroacetimidate 4 as a novel glycosyl
donor.
PMID- 10782689
TI - 5'-[2-(2-Nitrophenyl)-2-methylpropionyl]-2'-deoxy-5-fluorouridine as a potential
bioreductively activated prodrug of FUDR: synthesis, stability and reductive
activation.
AB - 5'-[2-(2-Nitrophenyl)-2-methylpropionyl]-2'-deoxy-5-fluorouridine was synthesized
as a potential bioreductively activated prodrug of 5-fluoro-2'-deoxyuridine
(FUDR). The target compound was stable in both phosphate buffer and human serum
and was found to release quickly the parent drug FUDR in quantitative yield upon
mild chemical reduction.
PMID- 10782691
TI - Novel 3-(4-piperidinylthio)-1H-indoles as potent nonopioid orally active central
analgesics.
AB - A series of 3-(4-piperidinylthio)-1H-indoles was synthesized and evaluated in
mice in the phenylbenzoquinone(PBQ)-induced writhing and hot plate tests. Most of
these compounds are good analgesics with activities comparable to that of
morphine. Among them compound 1i (UP 237-61), which has a strong serotonin
binding profile, has an interesting antinociceptive activity which is not
reversed by naloxone.
PMID- 10782690
TI - Incorporation of a 4-hydroxy-N-acetylprolinol nucleotide analogue improves the 3'
exonuclease stability of 2'-5'-oligoadenylate-antisense conjugates.
AB - Incorporation of a 4-hydroxy-N-acetylprolinol nucleotide analogue at the 3'
terminus of DNA or 2-5A-DNA sequences resulted in a significantly enhanced 3'
exonuclease resistance while the affinity for complementary RNA was only slightly
decreased. Furthermore, the binding to and activation of human RNase L by thus
modified 2-5A-DNA conjugates was not altered as compared to the parent unmodified
2-5A-DNAs.
PMID- 10782692
TI - Leukotriene B4 photoaffinity probes: design, synthesis and evaluation of new
arylazide-1,3-disubstituted cyclohexanes.
AB - The synthesis and the binding affinities of new leukotriene B4 receptor
photoaffinity probes, where a 1,3-disubstituted cyclohexane ring replaces the
conjugated delta6,7 and delta8,9 double bonds of the natural eicosanoid, are
described. One enantiomeric compound, 4b alpha, is specifically cross-linked upon
photolysis to the recombinant leukotriene B4 receptor from human origin (h-BLTR)
solubilized in a micellar medium. This probe appears as a good candidate for
identifying the ligand binding site of this receptor.
PMID- 10782693
TI - Synthesis and antibacterial activity of novel 6-O-substituted erythromycin A
derivatives.
AB - A series of novel 6-O-substituted erythromycin A derivatives has been
synthesized. Good in vitro antibacterial activity has been demonstrated for
analogues incorporating a variety of structural features. The methodology
disclosed is expected to find application in the design of future macrolide
antibiotics that target the prevalent bacterial resistance problem.
PMID- 10782694
TI - Design, synthesis, and structure-activity relationship studies of ATP analogues
as DNA gyrase inhibitors.
AB - We report herein the design and synthesis of ATP-analogues, namely 4-amino
pyrazolo[3,4-d]pyrimidines and 4-amino-pyrazolo[1,5-a][1,3,5]triazines, with DNA
gyrase inhibitory activity. Among these series, some compounds exhibited
promising antibacterial activity.
PMID- 10782695
TI - Chemo- and enzymatic synthesis of partially and fully N-deacetylated 4
methylumbelliferyl chitobiosides: fluorogenic substrates for chitinase.
AB - Partially and fully N-deacetylated 4-methylumberlliferyl chitobioside (1)
derivatives, such as GlcN-GlcNAc-UMB (2), GlcNAc-GlcN-UMB (3), and (GlcN)2-UMB
(4), were synthesized using chemo- and enzymatic procedure. Fluorescent aglycon
was released from the chitobiosides 1, 2 and 3 by the action of chitinase. These
UMB glycosides of heterochitobiose were versatile probes for the investigation of
substrate binding chitinase from various sources.
PMID- 10782696
TI - ORL1 receptor ligands: structure-activity relationships of 8-cycloalkyl-1-phenyl
1,3,8-triaza-spiro[4.5]decan-4-ones.
AB - We have investigated 8-cycloalkyl-1-phenyl-1,3,8-triaza-spiro[4.5]decan-4-o nes
as ligands for the ORL1 receptor. These unsophisticated, achiral compounds show
remarkable affinity for the ORL1 receptor. Optimizing for selectivity we show
that the maximum of affinity and selectivity versus the other opioid receptors is
achieved for 8-cyclodecyl-1-phenyl-1,3,8-triaza-spiro[4.5]decan-4-o ne 2e and 8
(cis-4-isopropyl-cyclohexyl)-1-phenyl-1,3,8-triaza-spiro[4.5] decan-4-one 2q. The
identified compounds (2e, 2q) are more or less equipotent to the natural ligand
itself, both in the binding assay and in the functional GTPgammaS assay.
PMID- 10782697
TI - A convenient extension of the Wessely-Moser rearrangement for the synthesis of
substituted alkylaminoflavones as neuroprotective agents in vitro.
AB - A series of 8-alkylamino-5,7-dihydroxyflavones was prepared from chrysine via a
seven step sequence. The synthesis of their 6-alkylamino isomers could be
subsequently accomplished through a convenient extension of the Wessely-Moser
rearrangement. These compounds were found to be efficient neuroprotective agents
in vitro.
PMID- 10782698
TI - Synthesis and antifungal activity of a ferrocene-fluconazole analogue.
AB - A novel ferrocene fluconazole analogue was synthesized and its antifungal
properties investigated against yeast strains of medical importance, including
those intrinsically resistant to fluconazole. In vitro tests revealed a slight
increase in fungal growth and a reversal of the effect of fluconazole at minimal
inhibitory concentrations.
PMID- 10782699
TI - Dynamics and control of the global tuberculosis epidemic.
AB - Studies of disease burden have reaffirmed that tuberculosis is among the top 10
causes of death in the world. The tuberculosis epidemic in most countries could
eventually be brought under control by implementing the World Health
Organization's (WHO) directly observed therapy, short course (DOTS) strategy,
although tuberculosis linked to human immunodeficiency virus (HIV) in Africa and
multidrug-resistant tuberculosis (MDR-TB) in the former Soviet Union urgently
demand adaptations and extensions of DOTS. Most high-incidence countries have
achieved treatment success rates approaching the WHO 85% target in pilot
projects. In the long term, we may have better diagnostics, drugs, and vaccines
to control the disease; for the next 5 years, the central problem in global
tuberculosis control is to expand DOTS coverage in high-incidence countries.
Improved case finding and diagnosis, coupled with best-practice short-course
chemotherapy, could quickly and dramatically cut the number of years of healthy
life lost due to tuberculosis, especially by preventing death.
PMID- 10782700
TI - Adult tuberculosis overview: African versus Western perspectives.
AB - Tuberculosis is currently an enormous global health problem. In industrialized
countries in Western Europe and North America, tuberculosis case rates are low
and an increasing proportion of cases now occur in foreign-born individuals and
in marginalized populations, including the homeless, prisoners, drug users, and
persons with human immunodeficiency virus (HIV) infection or acquired
immunodeficiency syndrome (AIDS). In contrast, the burden of tuberculosis in sub
Saharan Africa continues to grow, largely fueled by the HIV pandemic and poor
public health infrastructure. Use of the World Health Organization's (WHO)
directly observed therapy, short course (DOTS) strategy has been successful in
improving outcomes and preventing the emergence of acquired drug resistance in
several African countries; however, case rates are increasing throughout most of
the region. It is clear that control of tuberculosis in Africa is closely linked
to control of HIV and AIDS. Substantial external donor support and innovative
approaches to enhance interactions between HIV/AIDS prevention and treatment
efforts and tuberculosis control programs will be needed to improve the current
tuberculosis situation in Africa. The purpose of this review is to provide a
synopsis of recent developments in these areas and to serve as a reference source
for interested readers.
PMID- 10782701
TI - Childhood tuberculosis.
AB - Childhood tuberculosis will reflect the incidence of cavitating pulmonary
tuberculosis in adults and will consequently be encountered most frequently in
those areas with a high incidence of tuberculosis. Problem areas include our
continuing inability to confirm the diagnosis of tuberculosis in many children,
the escalating interaction of the human immunodeficiency virus (HIV) pandemic and
tuberculosis, which is now evident with greater frequency in childhood, and the
scarcity of data relating to antituberculosis therapy in childhood, which
necessitates reliance on adult studies in many cases. This review highlights
several options for obtaining material for culture of Mycobacterium tuberculosis
in children, aspects of tuberculin testing, which remains one of the cornerstones
supporting a diagnosis of tuberculosis in childhood, the potential importance of
therapeutic drug monitoring in problem cases, new data giving epidemiologic and
clinical details of the interaction of HIV infection and tuberculosis in
children, and studies describing the epidemiology of tuberculosis in the
developed and developing world.
PMID- 10782702
TI - Advances in the management of tuberculosis: clinical trials and beyond.
AB - Modern short-course treatment for tuberculosis is highly effective and cost
effective, yet the disease remains a leading cause of suffering and death. The
problem has been exacerbated in recent years by the human immunodeficiency virus
(HIV) pandemic and the increasing prevalence of multidrug-resistant tuberculosis.
Improvements in diagnosis, vaccination, chemoprophylaxis, and therapy are thus
urgently needed. Molecular techniques are facilitating the development of rapid
and sensitive diagnostic tests and the rational approach to the production of new
vaccines. New forms of treatment are being investigated and there is also
considerable emphasis on optimizing the deployment of the available treatment
regimens. This has resulted in the World Health Organization's five-point
directly observed therapy, short course (DOTS) strategy and proposed
modifications (DOTS-plus) for the management of multidrug-resistant (MDR)
tuberculosis. Despite these advances, it is becoming abundantly clear that the
failure to control tuberculosis is a direct consequence of the gross inequities
in the distribution of wealth and health care provision worldwide, which do not
allow for putting advances in the management of tuberculosis into practice. The
control of tuberculosis will therefore require attention to justice and human
rights as well as greatly increased technical and financial support from the
developed nations.
PMID- 10782703
TI - Drug-resistant tuberculosis.
AB - There is increasing concern in many countries about the problem of drug-resistant
tuberculosis, particularly so because no new classes of drugs have been developed
for the treatment of tuberculosis since the 1960s. Although drug resistance is
thought to be fairly common in some countries and rare in others, the global
extent of this condition is not precisely known. This problem is currently being
investigated by a combined initiative of the World Health Organization and the
International Union Against Tuberculosis and Lung Disease. Recently, there have
been advances in the understanding of the genetic basis of drug-resistant
tuberculosis. With the sequencing of the whole genome of Mycobacterium
tuberculosis, the possibility of new targets for drug development has emerged.
For the present, however, cure rates on average remain modest, and nonadherence
with chemotherapy remains a major problem. Drug resistance is a man-made problem
and efforts to prevent it through directly observed therapy, short course are
essential.
PMID- 10782704
TI - Tuberculosis vaccines: developmental work and the future.
AB - The last year in tuberculosis vaccine research has witnessed the initial
flowering of the benefits promised by the tuberculosis genome sequencing product.
Although the real benefits in terms of clinical treatments are yet to be
realized, genomics is making its presence felt in the rapid identification and
expression of proteins with vaccine potential from Mycobacterium tuberculosis,
the definition of species-specific antigens for diagnostic use, and the
construction of a variety of novel living vectors for vaccination. At the same
time, the recent increase in work on animal models with more direct applicability
to the situations likely to be encountered in human vaccine trials are providing
the basic underpinnings needed for the assessment of these new vaccines.
PMID- 10782705
TI - Advances in understanding pulmonary host defense mechanisms: dendritic cell
function and immunomodulation.
AB - Mucosal host immunity in the respiratory tract can probably be manipulated to
better improve defense against microbes and other antigens or particulates that
cause infection and respiratory illness. An evolving strategy is to target the
extensive network of dendritic cells in the lungs, especially dendritic cells
located in the airway epithelium, which are super antigen-presenting cells that
can initiate specific T-lymphocyte immune responses. Also, dendritic cells can
elaborate cytokines such as interleukin 12 which drive other components of the
immune response including antibody production. However, dendritic cells can be
counter-regulated by inhibitory cytokines or certain microbes that create a
dynamic interplay. This review emphasizes human studies and relevant animal
models that provide a framework for future planning of experimental approaches to
enhancing antimicrobial immunity and respiratory host defense.
PMID- 10782706
TI - Sinusitis in adults.
AB - Symptoms of sinusitis are among the most common reasons for patients presenting
to primary care physicians. There is considerable controversy regarding
appropriate management of both acute and chronic sinus disease. This article
reviews etiologic mechanisms in these conditions and presents recent evidence to
provide a logical basis on which to make decisions regarding medical and surgical
therapy.
PMID- 10782707
TI - Acute and chronic sinusitis in children.
AB - There is one subject in recent publications on pediatric sinusitis on which most
authors agree, and that is that the public cannot continue to receive antibiotics
on demand solely because of purulent nasal discharge, and that clinicians cannot
continue to prescribe broad-spectrum and expensive antibiotics for minimal
indications. Two publications show that the prevalence of various anatomical
variations is no greater in children with rhinosinusitis than in a control group.
This mirrors recent work in adults and implies that immunity and the way the
mucosa reacts to pathogens is likely to be of primary importance, rather than the
anatomy. Several good reviews on the management of rhinosinusitis in children all
emphasize the need for medical and not surgical management of these patients
except in cases in which the complications of sinusitis develop. The fact that
computed tomography is poor at diagnosing sinusitis in children is also a
recurring theme.
PMID- 10782708
TI - Community-acquired pneumonia.
AB - Community-acquired pneumonia (CAP) remains a leading cause of morbidity and
mortality worldwide and has significant financial implications for health-care
systems. The epidemiology and fundamental biology of the disease has evolved,
reflecting the human immunodeficiency virus pandemic, increasing world travel,
and, as always, poverty. The promise held out by molecular diagnostic technology
has yet to deliver in this arena, and antibiotic resistance continues to drive
the quest for new antimicrobial agents. The emergence of multidrug-resistant
Streptococcus pneumoniae, the microorganism most often implicated as a cause of
CAP, continues to threaten treatment options. The evolution of this organism, the
persistently high mortality rate associated with CAP, and increasing health-care
costs have prompted the publication of guidelines by various authorities that can
be used to assist in the initial assessment of the patient and then guide
empirical antimicrobial therapy. It is unclear whether these guidelines will have
significant impact on cost and mortality, although the trend toward a rational
and evidence-based approach to antimicrobial therapy must be a goal to aspire to.
PMID- 10782709
TI - Pyogenic lung infections: factors for predicting clinical outcome of lung abscess
and thoracic empyema.
AB - Lung abscess and thoracic empyema continue to cause significant morbidity and
mortality despite appropriate antibiotic therapy and various options for drainage
of empyema. Multiple factors, including the patient's general state of health,
the presence of underlying disease, the virulence of the pathogen responsible,
and the promptness of drainage of empyema, appear to dictate the clinical
outcome. However, the available data are derived from uncontrolled, retrospective
studies and the high morbidity and mortality rates underscore the need for large
prospective studies to better evaluate factors that may predict the clinical
outcome of these conditions.
PMID- 10782710
TI - Human immunodeficiency virus and respiratory infection.
AB - Pulmonary disease remains a major problem for the 33 million individuals who are
thought to be infected with human immunodeficiency virus (HIV) worldwide.
Respiratory infections are responsible for a large number of the 2 million deaths
that occur each year in association with HIV disease. In countries where the
majority of the population can access highly active antiretroviral therapy,
morbidity and mortality rates have been cut by up to 80%. This has allowed the
withdrawal of specific opportunistic infection prophylaxis when immune
restoration is deemed to be adequate. Recommendations have been published
concerning Pneumocystis carinii prophylaxis. This year has also seen further
reports of drug-resistant isolates of Pneumocystis carinii. The clinical
relevance of this is still debated. Tuberculosis remains a global problem. The
complexity of the interactions between specific anti-HIV and anti-tuberculous
treatment have been highlighted. In the developing world, the importance of
immunization and prophylaxis (against bacteria and mycobacteria) have recently
been further defined in a number of studies.
PMID- 10782711
TI - Respiratory infections in the traveler.
AB - The growth of travel of recent years has been unprecedented and presents new
challenges to health professionals worldwide. More travelers of diverse
backgrounds are visiting exotic locales rarely encountered before. This poses new
risks to health, in addition to potentially aiding the spread of emerging
respiratory infections. Travelers such as immunocompromised individuals and
members of ethnic minorities are at significant risk for travel-related
infections. Respiratory illnesses are some of the most common infections
affecting human beings, yet little information has been published on them in
relation to travel. Multidisciplinary approaches and collaboration across
different sectors are needed to address the many issues involved in travel
related respiratory infections. This article discusses some of the topical issues
of respiratory tract infections occurring in travelers.
PMID- 10782712
TI - Advances in antimicrobial therapy for respiratory tract infections.
AB - Even at the turn of the millennium, respiratory infections exact a heavy toll on
the American public. Pneumonia is the leading infectious disease cause of death,
and influenza costs Medicare more than $1 billion each year. This article
highlights some of the advances this past year in antimicrobial therapy for
respiratory tract infections. Efforts are targeted at shortening the length of
treatment and reducing costs for pneumonia. A promising new class of antivirals
has been introduced for the treatment of influenza, and alternative medicine
continues to receive more scientific scrutiny. Antimicrobials alone are not the
answer, and preliminary work on immunomodulatory therapies may usher in a new era
of multifaceted treatment approaches.
PMID- 10782713
TI - Bibliography. Current world literature. Infectious diseases.
PMID- 10782714
TI - Perspectives in suicidology: families, mental illness, and suicide.
AB - The ways in which the key words "family," "mental illness," and "suicide" are
interpreted in the context of research into suicide will influence the formation
of theories, the interpretation of results, and the development of suicide
prevention strategies. It is argued that there is no general agreement about the
meaning of these words.
PMID- 10782715
TI - Collaborating to prevent suicide: a clinical-research perspective.
AB - It is argued that suicidality is essentially a relational phenomenon; the
presence or absence of certain key relationships paradoxically can be both
suicide causing and suicide preventive. The relational aspects of suicide are
especially poignant in clinical work with suicidal patients. However, when
suicidality is involved, there are a number of issues that can interfere with
effective clinical practice. Fortunately, a new paradigm has begun to emerge in
contemporary clinical suicidology, which objectifies suicidality and emphasizes
the phenomenology of suicidal states. Moreover, from an increasingly empirical
perspective, this approach is creating new and better ways to effectively assess
and treat suicidal conditions.
PMID- 10782716
TI - The suicidal mode: a cognitive-behavioral model of suicidality.
AB - This article discusses the theoretical foundation and potential clinical
application of the suicidal mode, a cognitive behavioral theory of suicidality.
The model presented represents a specific elaboration of Beck's modal theory of
psychopathology. In addition to discussing the fundamental requirements of a
theory of suicidality, the theoretical assumptions of the suicidal mode are
identified, its component parts defined, its inherent strengths emphasized, and
its application in clinical settings detailed. Definition of a modal theory of
suicidality represents the growing influence of cognitive-behavioral theory in
efforts at psychotherapeutic integration in clinical suicidology.
PMID- 10782717
TI - Depression, suicide, and suicide prevention in schizophrenia.
AB - Suicide is the single largest cause of premature death among individuals with
schizophrenia. Furthermore, epidemiological data indicate that nearly 80% of
patients with the diagnosis of schizophrenia will experience a major depressive
episode at some time during their lifetime. This report reviews recent findings
relative to the risk of suicide in schizophrenia, including data from the
Chestnut Lodge longitudinal study of schizophrenia subtypes and symptom domains.
Paradoxically, those patients with schizophrenia who are most likely to recover
or experience a good outcome are also those at greatest risk for suicide. The
reduction of morbidity and mortality in schizophrenia should include depression
and suicidality as targets for both psychopharmacological and psychosocial
treatment.
PMID- 10782718
TI - Writing projects: lessening undergraduates' unique suicidal bereavement.
AB - To assess if writing projects lessen undergraduates' grief following a loved
one's suicide, 40 students whose loved one died by suicide in the past 2 years
wrote on four occasions over 2 weeks about profound topics (e.g., events and
emotions surrounding the death) or trivial topics (e.g., description of the
previous meal). All participants completed pre- and posttest measures of grief
and self-reported health visits, and 75% completed the same measures at 6-week
mailed follow-up. As expected, individuals in the profound condition reported
less grief associated with suicide at follow-up than those in the trivial
condition. However, the trivial and profound groups were not significantly
different in general grief or health visits. Writing about grief associated with
the suicide of a loved one appeared to reduce suicidal grief associated with this
event. However, this benefit did not extend to general grief or physical health.
PMID- 10782720
TI - Suicide among adolescents and young adults: a cross-national comparison of 34
countries.
AB - Few cross-national reports have examined suicide rates among adolescents and
young adults. A survey of suicides among 15-24-year-olds in 34 of the wealthiest
nations demonstrated that 15,555 youths killed themselves in a 1-year study
period. Thirty-four percent of these suicides were firearm-related. Finland led
the participating nations in total and firearm-related suicide rates. An
association was found between divorce rates and youth suicide rates, firearm
related suicide among youths, and suicide rates among young males. For a smaller
sample of countries, an association was found between firearm availability and
firearm-related suicide rates among youths and suicide rates among young males.
PMID- 10782719
TI - Suicidal behavior in the municipality of Baerum, Norway: a 12-year prospective
study of parasuicide and suicide.
AB - The present 12-year (1984-1995) surveillance study includes all hospitalized
parasuicide patients (n = 1,031) as well as all suicides (n = 161) in the
municipality of Baerum, a suburb of Oslo. The parasuicide rate decreased from 170
per 100,000 in 1984 to 79 per 100,000 in 1995 (53.5%). The parasuicide rates were
lower than those in several comparable studies. Rates were higher for divorced
females and separated males compared to married and other marital states, and the
pattern of relative risk of parasuicide with respect to marital status was
stable. Unemployment and substance abuse were positively correlated with
parasuicidal behavior for both males and females. Approximately 33% reported one
or more previous parasuicidal acts, and 21% repeated the parasuicide during the
observation period. Ninety-four percent used self-poisoning as parasuicide
method. A total of 2.4% of the parasuiciders committed suicide during the
observation period. The mean annual suicide rate in Baerum was 19.0 per 100,000
compared to the national average of 14.7. The results support the notion of
parasuicide and suicide being two different but overlapping populations. The
implementation of a follow-up system for parasuiciders may have contributed to
the reduced parasuicide rate during the study period.
PMID- 10782721
TI - Mansur Zaskar: a man almost bored to death.
PMID- 10782722
TI - Magnetic resonance imaging of the normal temporal bone.
AB - Recent advances in magnetic resonance imaging (MRI) technology has allowed the
development of imaging sequences tailored to the assessment of exquisite anatomic
detail of the temporal bone structures. This article describes MRI of the normal
temporal bone anatomy, with emphasis on common anatomic variants and clinically
relevant structures.
PMID- 10782724
TI - Magnetic resonance imaging for evaluation of otic labyrinth pathology.
AB - The auditory (cochlear) labyrinth, the cochlea, holds the hearing sensory
receptors. The vestibular labyrinth contains the sensory receptors for balance,
which lie in the three semicircular canals and in the otolithic organs (the
saccule and utricle). Pure tone audiometry and brain stem evoked audiometry can
help to differentiate a peripheral cochlear disorder from central lesion. The
type of nystagmus, severity of postural instability, and neurological evaluation
can help to differentiate a peripheral vestibular disorder from a central
vestibular lesion. The decision whether to perform an appropriate imaging such as
brain imaging versus labyrinthine imaging depends on the clinical and
paraclinical information provided to the radiologist by the neurotologist,
neurologist, or other clinicians. The magnetic resonance imaging characteristics
of peripheral cochlear and vestibular lesions are the main focus of this article.
PMID- 10782723
TI - Congenital sensorineural hearing loss and enlarged endolymphatic sac and duct:
role of magnetic resonance imaging and computed tomography.
AB - During the past 20 years, there have been significant advances in cochlear
implants as the treatment of choice for profoundly hearing-impaired children. The
increasing application of cochlear implant has brought with it an increase in the
investigational use of computed tomography and magnetic resonance imaging. In
this article, the author reviews (a) the anatomy and embryology of the inner ear,
(b) the pathological changes associated with congenital sensorineural hearing
loss (SNHL), and (c) the spectrum of imaging findings in patients with SNHL.
PMID- 10782725
TI - Value of imaging in disorders of the facial nerve.
AB - Imaging of the facial nerve has proved its usefulness to physicians in the
evaluation of pathological conditions of this nerve. Magnetic resonance imaging
(MRI) of the facial nerve should always be obtained selectively and should
include the parotid gland in case of peripheral facial nerve palsy. Gadolinium
DTPA contrast pulse sequence is the most informative MRI study for evaluation of
facial nerve pathology. This article reviews the imaging anatomy of the facial
nerve and describes the clinical features and MR characteristics of common
disorders of the facial nerve.
PMID- 10782726
TI - Magnetic resonance imaging of the internal auditory canal.
AB - Magnetic resonance imaging (MRI) is presently the study of choice for assessment
of the internal auditory canal (IAC). MRI provides excellent assessment of the
IAC and the bony changes occurring in the canal walls, and it provides excellent
demonstration of the content of the canal. Pathological processes arising within
the IAC are well visualized by various MR sequences. The possibility of
demonstrating masses as small as 2 mm has propelled MRI into the leading role for
diagnosis of vestibular schwannoma. Unfortunately, the high cost of MR has been a
limiting factor in its use as a screening test for patients with sensorineural
hearing loss (SNHL) of unknown origin. Auditory brain stem response has been
widely used as a screening procedure, but this test fails to recognize small
lesions and cannot be used whenever hearing loss is severe. In this article, we
will discuss our approach to assessment of the IAC in patients with retrocochlear
SNHL or vestibular symptoms of central origin, review the pathological processes
involving the IAC walls or arising within the canal, emphasizing the appropriate
MRI sequences used for diagnosis.
PMID- 10782727
TI - Langerhans histiocytosis of temporal bone: role of magnetic resonance imaging.
AB - Langerhans cell histiocytosis (LCH) may involve nearly every organ of the body.
In children, head and neck involvement has been reported in as many as 82% of
patients. Sites of head and neck involvement include skull, temporal bone, orbit,
mandible, maxilla and cervical nodes. In addition, patients may have coexisting
central nervous system (CNS) involvement adjacent to, or remote from, osseous
lesions. Magnetic resonance imaging (MRI) of the temporal bone in patients with
LCH is ideal for evaluating the extracranial extent of the soft-tissue mass and
is complementary to computed tomography (CT) in the assessment of osseous
erosion. MRI is superb in the evaluation of intracranial extension, usually into
the middle cranial fossa, and of patency of adjacent vascular structures. It is
the imaging modality of choice to evaluate patients with suspected CNS
involvement of LCH, which includes lesions of the infundibulum, cerebrum,
cerebellum, and extra-axial spaces.
PMID- 10782728
TI - Increasing access to renal transplantation in the 21st century.
PMID- 10782729
TI - Maintenance immunosuppression: new agents and persistent dilemmas.
AB - Since the approval of cyclosporine in 1983, only 3 drugs, mycophenolate mofetil,
tacrolimus, and sirolimus, have been approved for maintenance immunosuppression
in renal transplant recipients. All 3 agents decrease the incidence of early
acute allograft rejection. An increase in intermediate and long-term graft
survival has not been shown. However, survival data from these clinical trials
should be interpreted with caution because the studies were not designed for this
purpose. All 3 drugs have significant, albeit different, safety profiles. It
remains to be seen whether, the lower incidence of hypertension and
hyperlipidemia seen in tacrolimus-treated patients will reduce the incidence and
severity of the cardiovascular disease experienced by renal transplant
recipients. Sirolimus causes severe hyperlipidemia, and the long-term
consequences both on the pathogenesis of cardiovascular disease and on lipid
associated renal injury have yet to be determined. Tacrolimus and mycophenolate
mofetil appear to increase graft survival in pancreas-kidney recipients but their
efficacy in another high-risk group, African-American recipients, has not yet
been clearly shown. However, the trend toward improved graft survival in African
American recipients treated with tacrolimus is encouraging. Steroid-withdrawal
remains a goal in the posttransplant period. The available data from steroid
withdrawal and steroid-avoidance clinical trials are mixed. Steroid withdrawal
can be achieved in about 50% of patients on a cyclosporine-based
immunosuppression regimen. Steroid-withdrawal under coverage of tacrolimus,
mycophenolate mofetil or Neoral (Novartis Pharmaceuticals, East Hanover, NJ) may
be more successful than that achieved in patients receiving Sandimmune (Novartis
Pharmaceuticals). Further studies are needed in this area.
PMID- 10782730
TI - Expanded criteria donors: attempts to increase the renal transplant donor pool.
AB - There is a growing disparity between the demand for and the supply of kidneys for
transplantation. The demographics of the donor pool are also changing. The
average potential cadaveric organ donor is now more likely to be older, at
greater risk for co-morbid conditions such as hypertension or viral infections,
and more likely to die from cerebrovascular disease. These factors have led to an
expansion of the criteria that defines the suitable organ donor. Expanded
criteria donors are defined as the following: (1) at the upper and lower extremes
in age; (2) having a history of hypertension or diabetes; (3) hemodynamically
unstable; (4) non-heartbeating (cardiopulmonary death rather than brain death);
(5) seropositive for hepatitis B or C; (6) having systemic infections; (7) having
displayed high-risk social behavior for HIV infection; (8) having a history of
malignancy; (9) having abnormal organ function; or (10) with renal anatomic
anomalies or injuries. Use of kidneys from these "expanded criteria donors" is a
two-edged sword. While they provide more organs for transplantation, the risk of
suboptimal recipient outcome is increased. A rational approach to the use of each
of these types of kidneys and proper selection of recipients is essential to
obtain acceptable results. The article reviews the factors that have contributed
to the successful transplantation of kidneys procured from expanded criteria
organ donors and how these organs can be allocated most efficaciously to the
appropriate recipients.
PMID- 10782731
TI - Infectious complications in renal transplant recipients.
AB - Infectious complications present major challenges to physicians caring for renal
transplant recipients. The high rate of infection reflects the net state of
immunosuppression associated with end-stage renal disease, transplantation, donor
and environmental exposure. An understanding of the factors that affect the
patients' overall state of immunosuppression is essential to prevent and treat
infectious complications, which may lead to significant morbidity, graft
dysfunction, or mortality. Familiarity with the various pathogens, clinical
presentation, diagnostic options, treatment, and prophylaxis is important to care
for renal transplant patients. The authors present their approach, based on
review of current literature, to these issues.
PMID- 10782733
TI - Israel (Sol) Penn (1930-1999).
PMID- 10782732
TI - Cancers in renal transplant recipients.
AB - Data regarding posttransplant cancers are reviewed from the Cincinnati Transplant
Tumor Registry (CTTR) and from the literature. The CTTR has data on 9,688 types
of cancer that developed in 9,032 renal allograft recipients. The predominant
tumors are lymphomas and lymphoproliferations (PTLD), carcinomas of the skin and
lips, carcinomas of the vulva and perineum, in situ carcinomas of the cervix of
the uterus, Kaposi's sarcoma (KS), hepatocellular carcinomas, renal carcinomas,
and various sarcomas (excluding KS). Prominent features of the PTLD cases are
their high incidence, frequent involvement of extranodal sites, a marked
predilection for the brain, and frequent involvement of the allograft by tumor.
Skin cancers also present unusual features, a remarkable high frequency of KS,
reversal of the ratio of basal cell carcinomas to squamous cell carcinomas that
is seen in the general population, the young age of the patients, the high
incidence of multiple tumors (in 44% of patients), and the aggressive behavior of
some squamous cell carcinomas. Cancers of the vulva and perineum occur at a much
younger age than in the general population and are preceded by a history of
condyloma acuminatum in over 57% of cases. Reduction or cessation of
immunosuppressive therapy is of value in some patients with PTLD or KS but
carries the risk of allograft rejection.
PMID- 10782734
TI - Progress in renal transplantation for children.
AB - Renal transplantation continues to be the goal of therapy for children with end
stage renal disease. Patient age, primary renal disease, psychosocial status,
living versus cadaver donor allograft, immunosuppressive therapy, urologic
status, and maximization of growth and development must be considered in
determining the optimal time for transplantation. Immunizations should be up to
date, and the immune status of both the donor and the recipient with regard to
Epstein Barr virus (EBV), cytomegalovirus (CMV), varicella, human
immunodeficiency virus (HIV) and Hepatitis A, B, and C must be known. Prednisone;
cyclosporine or tacrolimus; and mycophenolate mofetil or azathioprine remain the
mainstays of immunosuppression. However, new therapies such as sirolimus are
under investigation for use in pediatric renal transplantation. Induction
therapies include T-cell antibodies as well as the more recent addition of
interleukin-2 receptor blockers. Complications including infection, rejection,
and malignancy continue to be problematic in pediatric renal transplantation.
There continues to be a strong focus on optimizing growth and development after
transplant. Although patient and graft survival have improved over time, outcomes
in pediatric renal transplantation continue to lag behind those in adults.
PMID- 10782735
TI - The role of the advanced practice nurse in the care of organ transplant
recipients.
AB - The role of the advanced practice nurse (APN) in transplantation has evolved from
the role of the clinical transplant coordinator. This report attempts to define
the credentials, practice domains, barriers to practice, and reimbursement issues
related to APN practice while contrasting the role with that of clinical
transplant coordinator. The nephrology APN working in a collaborative transplant
practice can be an integral part of a multidisciplinary health care team. The
APN's education and credentials empower them to provide a wider scope of services
than transplant coordinators who are "experts by experience." These services can
include providing primary care and performing procedures such as percutaneous
transplant biopsies, insertion of peripheral and central venous catheters, and
wound debridement as well as management of patients along their continuum of
transplant care. Patient education and advocacy also are key components of APN
practice. In addition, the services the APN provides generally are reimbursable
and therefore can provide revenue for the practice.
PMID- 10782736
TI - Patient-nephrologist discussions about kidney transplantation as a treatment
option.
AB - Little is known about how nephrologists discuss transplantation as a treatment
option with end-stage renal disease patients. The authors sought to describe the
content and manner of patient-nephrologist discussions about transplantation.
Using a cross-sectional study design, we interviewed 79 chronic hemodialysis
patients and 12 nephrologists using a semistructured questionnaire that focused
on nephrologist and patient reports of discussions about transplantation. The
authors found that nephrologists provided information on treatment options
gradually over several weeks to months. They generally presented the option of
dialysis first, then transplantation, but avoided discussing mortality data.
Nephrologists said they encouraged most patients, but especially young patients,
to seek transplantation. Of all patients, 68% reported being encouraged to seek
transplantation by nephrologists. Low socioeconomic status patients were less
likely to report being encouraged to seek transplantation even after adjustment
for transplant suitability. Both nephrologists and patients avoided discussing
life expectancy data. In conclusion, patient age and socioeconomic status appear
to influence discussions of transplantation as a treatment option. Further work
is needed to determine how the content and manner of such discussions affect
treatment decisions.
PMID- 10782737
TI - The ECB renal patient questionnaire: an assessment tool to determine renal
patients' needs for immediate social work intervention.
AB - Medicare mandates that all persons with end-stage renal disease (ESRD) receive
clinical social work assessment and intervention for psychosocial needs. Crisis
intervention rather than preventative social service often occurs because of an
annual increase in the number of patients diagnosed with ESRD, tightening of
social work budgets, larger and more complex case loads, diminishing resources
and staff, increased patient acuity, and emphasis on outpatient care. To decrease
crisis intervention episodes, enhance allocation of time and resources, and
improve quality of patient care, the authors investigated the creation of a
short, self-administered, easily scored instrument to predict ESRD patients in
need of immediate social work intervention. In 4 research phases, from 1986 to
1994, with 791 subjects from all ESRD treatment modalities, the ECB Renal Patient
Questionnaire (ECB) was developed. The ECB is a 30-item questionnaire that is
highly reliable, valid, easy to administer and score, and is accurate with
frequent use. It has been tested nationally to establish scoring norms. The
research phases are reported here to make the ECB more widely available to renal
health care professionals.
PMID- 10782738
TI - Traditional intravaginal practices and the heterosexual transmission of disease:
a review.
AB - OBJECTIVE: To review reports on the use and effects of traditional intravaginal
substances and practices. METHOD: The medical and social science literature of
the past 50 years regarding use and effects of traditional intravaginal
substances and practices is reviewed. RESULTS: Traditional intravaginal practices
have been described in 11 countries of sub-Saharan Africa, and also in Qatar,
Indonesia, Thailand, Haiti, the Dominican Republic, and the United States.
Women's reasons for the practices include personal hygiene, disease prevention or
treatment, and enhancement of sexual experience. Few studies document damage to
the vaginal epithelium or changes in vaginal flora due to these practices. No
prospective studies link these practices to disease transmission. CONCLUSION: The
determination of how these practices affect disease transmission will require
precise definition of independent variables, which is difficult because of the
diversity of the practices. It is appropriate to search for intervening
variables; specifically, the effects on the vaginal pH, flora, and epithelium.
PMID- 10782739
TI - Potential for community-based screening, treatment, and antibiotic prophylaxis
for syphilis prevention.
AB - BACKGROUND: The recent syphilis epidemic in Louisiana occurred predominantly
among disadvantaged African Americans who may distrust public health agencies and
prevention efforts. OBJECTIVES: To determine community perceptions regarding
trust and use of public health clinics, to assess whether race of provider is
important to persons at risk for syphilis, and to assess the willingness of
persons to participate in syphilis screening, treatment, and antibiotic
prophylaxis. STUDY DESIGN: Qualitative interviews were conducted with 18
community leaders and 38 community members who were at risk for syphilis.
Quantitative surveys were completed by persons with primary or secondary syphilis
(n = 92), their sexual contacts (n = 56), and with neighborhood controls (n =
143). Three possible programs for syphilis screening and antibiotic prophylaxis
were proposed (1) bar setting; (2) home setting, and (3) mobile health-van
setting in high-risk communities. RESULTS: In qualitative interviews, community
leaders and community members reported a high degree of trust in the public
sexually transmitted disease clinic. A majority of respondents felt that race was
not a factor in choosing healthcare providers. Respondents favored the provision
of services in a mobile health van over in a bar or in their homes. In
quantitative interviews, more than 80% of community members surveyed reported
that they would go to a mobile health van for syphilis testing. Nearly two thirds
of respondents reported that they would be willing to take oral prophylaxis for
syphilis, and more than half of respondents reported that they would accept an
injection. CONCLUSIONS: Community members trust the public sexually transmitted
disease (STD) clinic, are generally not concerned with the race of healthcare
providers, and are supportive of community-based STD screening, treatment, and
antibiotic prophylaxis provided from a mobile clinic.
PMID- 10782741
TI - Gonorrhea in male adolescents and young adults in Newark, New Jersey:
implications of risk factors and patient preferences for prevention strategies.
AB - BACKGROUND: Although the national rate of gonorrhea declined 68% from 1975 to
1995, rates remain high in many inner-city areas. In 1995, the gonorrhea rate in
Newark, NJ, was five times the US rate. OBJECTIVE: To determine factors
associated with acquisition of gonorrhea by men in Newark. STUDY DESIGN: A case
control study conducted at the sexually transmitted disease (STD) clinic in
Newark, comparing males 15 to 29 years with culture-confirmed gonorrhea to
controls with no STD. RESULTS: Compared with controls, males with gonorrhea more
frequently reported at least 1 casual sex partner within the preceding month
(adjusted odds ratio [OR], 3.2; 95% CI, 1.8-5.7), sex after using marijuana
during the preceding month (OR, 2.4; 95% CI, 1.1-5.3), and a history of
incarceration (OR, 2.1; 95% CI, 1.2-3.7). Of males with casual partners, having a
new casual sexual relationship (onset within the past month) was particularly
risky for gonorrhea (OR, 3.9; 95% CI, 1.2-12.7). Incorrect condom use was highly
prevalent for both cases and controls. Many persons with gonorrhea reported that
they were not willing to consistently use condoms or to have only one partner.
CONCLUSIONS: Sex with casual partners is associated with gonorrhea in males, and
may be a difficult practice to change. Condoms are often used incorrectly, if at
all, in this population. Prevention strategies, in addition to the promotion of
condom use and monogamy, may be necessary.
PMID- 10782740
TI - To notify or not to notify: STD patients' perspectives of partner notification in
Seattle.
AB - BACKGROUND AND OBJECTIVES: To obtain patients' perspectives on why only some
partners are notified in partner-notification programs, the cornerstone of
sexually transmitted disease (STD) control, although low proportions of partners
are located and evaluated. GOALS: To describe patterns of partner notification
reported by persons with STD infection. STUDY DESIGN: In-depth interviews
conducted in Seattle with 60 heterosexual men and women with gonorrhea,
chlamydial infection, or nongonoccocal urethritis, and 19 men with gonorrhea
reporting sex with men (MSM) were tape recorded, transcribed verbatim, and
content analyzed. RESULTS: The typical notification pattern was to notify a main
partner but not others. Least likely to be notified were partners perceived as
transmitters, contacts preceding the onset of symptoms, the oral sex and
anonymous contacts of MSM, one-time partners of men, and incarcerated and former
partners of women. Fears among young heterosexual participants included gossip
and violence (women). Fears among MSM included rejection. CONCLUSIONS: Partner
notification programs should develop innovative approaches for partners perceived
as transmitters, oral-sex only contacts of MSM, and contacts preceding symptom
onset.
PMID- 10782742
TI - A prospective study on condom slippage and breakage among female brothel-based
sex workers in Singapore.
AB - BACKGROUND: Concerns about the effectiveness of condoms in preventing sexually
transmitted diseases have been raised. Data are lacking on condom failure and its
associated factors among sex workers in Southeast Asia. GOAL: To assess factors
associated with condom breakage and slippage. STUDY DESIGN: A prospective study
on condom breakage and slippage over a 1-day period was conducted among 219
female brothel-based sex workers in Singapore in 1997. RESULTS: Condom breakage
and slippage rates among 1,885 episodes of condom use were 1.2% (95% CI, 0.7-1.8)
and 2.1% (95% CI, 1.2-3.0), respectively. After adjusting for intracluster
effects and confounders, condom breakage and slippage were significantly
associated with duration of sex work and spontaneity of clients to use condoms.
CONCLUSION: Condom use among sex workers should be promoted in view of the low
failure rates. Strategies to reduce condom breakage and slippage should be
directed at sex workers with increased risk of condom failure.
PMID- 10782744
TI - Gonorrhea, chlamydia and the sexual network: pushing the envelope.
PMID- 10782743
TI - Comparative epidemiology of heterosexual gonococcal and chlamydial networks:
implications for transmission patterns.
AB - OBJECTIVE: Networks of sex-partner interaction affect differential risk of
acquiring sexually transmitted infections. The authors evaluated sociodemographic
and behavioral factors that correlated with membership in networks of gonococcal
and chlamydial transmission. METHODS: Face-to-face interviews were conducted with
127 patients with gonorrhea and 184 patients with chlamydia (index cases) and
their named sex partners, as well as the partners of infected partners. Detailed
information was obtained regarding demographic, behavioral, and sexual-history
characteristics of all respondents. RESULTS: Gonococcal-network members differed
significantly from chlamydial-network members in a number of demographic
variables, including race or ethnicity, education, and unemployment status.
Gonococcal-network members were more likely to report past history of crack
cocaine use, sexual assault, and having been in jail. Gonococcal-network members
also reported having more sex partners during the past 1 year and 3 months than
did chlamydial-network members. Gonococcal and chlamydial mixing matrices
demonstrated assortativeness for sex partner selection by race or ethnicity but
not by sexual activity level, and no systematic differences between networks were
noted. Gonococcal networks were larger than chlamydial networks. CONCLUSIONS:
Network analyses of gonococcal and chlamydial infections demonstrated significant
differences in sociodemographic and behavioral variables. Further research is
required to delineate specific predictors of network membership among persons at
risk for sexually transmitted infections.
PMID- 10782745
TI - Mycoplasma genitalium in males with nongonococcal urethritis: prevalence and
clinical efficacy of eradication.
AB - BACKGROUND: Mycoplasma genitalium is regarded as a potential pathogen of the
human urogenital tract based on prevalence findings of several European studies.
GOAL: To determine the prevalence of M genitalium in urethral specimens of
symptomatic patients with nongonococcal urethritis and from asymptomatic patients
attending a sexually transmitted disease clinic in Milan, and to verify the
clinical efficacy of M genitalium eradication by antibiotic treatment. STUDY
DESIGN: From May 1998 to late April 1999, a routine analysis for M genitalium by
DNA amplification (polymerase chain reaction) was performed in patients attending
the Institute of Dermatological Science in Milan. The authors examined urethral
swabs from 178 symptomatic and 23 asymptomatic males. M genitalium-positive
patients were clinically and microbiologically tested after treatment with either
doxycycline or azithromycin. RESULTS: Among males with nongonococcal urethritis,
M genitalium was detected in 14.0% of patients as the only agent; in 15.1% of
patients in association with Chlamydia trachomatis and/or Ureaplasma urealyticum;
and in 1 asymptomatic patient. In all symptomatic M genitalium-positive patients,
antibiotic treatment eradicated the infection and cured clinical symptoms.
CONCLUSION: These data reveal the high prevalence of M genitalium in symptomatic
patients, the rarity of asymptomatic carriers, the high susceptibility to
antibiotic treatment, and the clinical efficacy of M genitalium eradication.
Moreover, data confirm the etiologic role of M genitalium in inflammatory
processes of the human urogenital tract in the Mediterranean area.
PMID- 10782746
TI - Candida vaginitis: self-reported incidence and associated costs.
AB - BACKGROUND AND OBJECTIVES: Incidence of Candida vaginitis by age and racial or
ethnic group is poorly described. GOAL: Estimate incidence, cumulative
probability of presumed C vaginitis by age, racial or ethnic group, and
associated costs. STUDY DESIGN: Random digit-dialing survey of 2000 US women.
RESULTS: A total of 6.5 percent (95% CI, 5.4-7.5%) of women older than 18 years
reported a least one episode of presumed C vaginitis during the previous 2
months. Women reporting a 1-year period with four or more episodes comprised 8.0%
of the sample but accounted for 37.2% of women reporting episodes. Black women
reported approximately three times more yeast infections in the previous 2 months
(17.4%; 95% CI, 11.2-23.5%) than white women (5.8%; 95% CI, 4.7-6.9%).
CONCLUSION: The high incidence and the propensity for recurrence underscore the
need for a better understanding of the epidemiology and pathogenesis, and stress
the need for the development of more accurate, rapid diagnostics and effective
treatments.
PMID- 10782747
TI - Comparative prevalence of infection with Trichomonas vaginalis among men
attending a sexually transmitted diseases clinic.
AB - OBJECTIVE: Although established in women as a common cause of vaginal discharge,
the prevalence of Trichomonas vaginalis (TV) in men compared with other classic
urethral pathogens has not been well characterized. To assess this issue, the
authors compared the prevalence of Neisseria gonorrhoeae (GC), Chlamydia
trachomatis (CT), and TV in consecutive men attending a sexually transmitted
diseases (STD) clinic. METHODS: From June 1, 1998 to July 27, 1998, 454
consecutive men presenting to the Denver Metro Health Clinic with a new problem
were tested for GC by urethral swab culture, for CT by polymerase chain reaction
of urine, and for TV by urine sediment culture. RESULTS: GC, CT, and TV were
detected in 23 (5.1%), 34 (7.5%), and 13 (2.8%) of men, respectively. There were
significant differences by age for both CT (11.3% in men younger than 30 years
versus 3.3% in men 30 years and older, P < 0.05) and TV (0.8% in men younger than
30 years versus 5.1% in men 30 years and older, P < 0.05). In 50 men 30 years or
older with symptoms of urethral discharge, TV prevalence (12.0%) rivalled that of
GC (12.0%) and CT (14.0%). In 45 men 30 years and older with nongonococcal
urethritis, the prevalence of TV and CT were each 13.3%. Multivariate logistical
regression analysis showed the presence of discharge and nongonococcal urethritis
in men 30 years and older to be an independent predictor of TV. CONCLUSIONS: TV
is common in men attending sexually transmitted disease clinics, especially in
those 30 years or older, in whom it may account for as much urethritis as GC or
CT. These findings suggest that in older men with nongonococcal urethritis,
diagnostic evaluation, empiric treatment, and partner management should include
the possibility of TV infection.
PMID- 10782748
TI - Consider diagnosis and treatment of trichomoniasis in men.
PMID- 10782749
TI - Calcium channel blockers in diabetic subjects: innocent at last?
AB - Calcium antagonists are indicted as a potential trigger of a variety of
complications spanning from myocardial infarction to bleeding and cancer. Three
randomised controlled trials, the MIDAS, the FACET and the ABCD trial, seem to
suggest that the risk for myocardial infarction is increased in diabetics on
calcium antagonists. These trials in aggregate totalled only 92 cardiovascular
events and it is possible that the observed differences were due to random
errors. Most of the patients of the ABCD trial discontinued the medication to
which they were initially randomised before the end of the study, which raised
the possibility of systematic bias. In both the MIDAS and ABCD studies
cardiovascular events were secondary end-points and the apparent adverse effects
were identified only by subgroup analyses. Furthermore, in both studies, patients
in the control groups were being treated with ACE inhibitors. The lack of a
placebo group makes it impossible to establish whether the observed effects were
due to the harmful influence of calcium antagonism or to the favourable effects
of ACE inhibition. New data abstracted from the PIUMA database show that the rate
of total cardiovascular and cardiac events did not differ between diabetics on
calcium antagonists and diabetics not using these drugs. These new data are in
keeping with findings in the HOT study where an impressive degree of cardiac
protection was observed in diabetic patients on felodipine.
PMID- 10782750
TI - Peripheral insulin sensitivity is decreased by elevated non-esterified fatty acid
level in dexamethasone-treated rats.
AB - The pathogenesis of glucocorticoid-induced insulin resistance in the peripheral
tissue was studied by perfusion experiments of the isolated rat hindquarter and
insulin tolerance tests in the rat with the cutting off operation of blood
supplies to the liver, kidneys, intestines and pancreas. The rat was injected
with 0.5 mg/kg dexamethasone for 7 days. Just after the multiple functional
organectomies, insulin was loaded in doses of 0.1 and 0.5 U/kg. Plasma insulin
levels during 0-10 min were approximately 100-20 and 500-100 microU/ml,
respectively. The decreasing rates in plasma glucose level after injections of
saline and 0.1 U/kg insulin were much smaller in dexamethasone-treated than
control rats (0.0+/-7.2 vs 13.3+/-3.4%/10 min, p<0.05, and 8.0+/-5.8 vs 39.4+/
3.7%/10 min, p<0.01 respectively). The decreasing rate after 0.5 U/kg insulin
loads was similar between both groups (40.2+/-10.0 in dexamethasone-treated and
52.3+/-7.3%/10 min in control rats). Plasma non-esterified fatty acids were
raised in dexamethasone-treated compared to control rats (1.23+/-0.23 vs 0.73+/
0.08 mM, p<0.01). In the hindquarter perfusion study, glucose uptake in the
dexamethasone-treated rat leg was no less than in the normal rat leg under a
palmitate-free condition, and was decreased by the addition of 1.0 mM palmitate
without and together with 100 and 500 microU/ml insulin. These results suggest
that the glucocorticoid-induced peripheral insulin resistance is characterised by
the decreased sensitivity and the preserved responsiveness to insulin, and is
caused mainly by an elevated non-esterified fatty acid level.
PMID- 10782751
TI - The effect of flavonoid treatment on the glycation and antioxidant status in Type
1 diabetic patients.
AB - Amongst the numerous co-adjuvant therapies which could influence the incidence
and progression of diabetic complications, antioxidants and flavonoids are
currently being tested in several clinical trials. In this study we investigated
the effects of Daflon 500, which is made up of the flavonoids diosmin (90%) and
hesperidin (10%), in a group of 28 Type 1 diabetic patients in a double blind
placebo-controlled study. Parameters of glycation and oxidative stress were
measured before and after the intervention. Treatment with this flavonoid had no
side effects and was followed by a decrease in HbA1c, from 8.85+/-1.57 to 8.47+/
1.40% (p=0.017). This decrease was more pronounced in the patients with higher
initial HbA1c but was unrelated to glycaemic control as monitored by the mean and
fluctuations of daily glycaemia. Decrease in HbA1c was accompanied by an increase
in glutathione peroxidase activity, from 119+/-68 to 145+/-42 U/l haemolysate
(p=0.015), a tendency for increase in plasma protein thiols and an increase in
the lag time of the copper-induced in vitro oxidability of non-HDL lipoproteins,
from 96+/-24 to 111+/-28 min (p=0.005). These parameters did not change
significantly after receiving placebo. Other parameters of antioxidant capacity
such as blood GSH, catalase and superoxide dismutase activities, as well as in
vitro formation of thiobarbituric acid reactive substances (TBARS), were
unaffected by either flavonoid or placebo. Our results suggest that the flavonoid
induced decrease in glycation is associated with an increase in the antioxidant
component dependent on the levels and activities of thiol-containing proteins
such as glutathione peroxidase. One mechanism which could explain these effects
is the protection of vitamin C and E from consumption by oxidative processes.
PMID- 10782752
TI - Glucose tolerance and insulin secretion in pregnancy.
AB - The authors have studied the behaviour of plasma glucose, insulinaemia and
insulin-glucose ratio in 2 groups of pregnant women with BMI values > or = or
<26, respectively. Each group was divided into 3 subgroups on the basis of an
oral glucose tolerance test (OGTT) response: GIGT (gestational impaired glucose
tolerance), GD (gestational diabetes), and C (normal controls). Data from non
obese pregnant women demonstrate that both basal and OGTT-stimulated glucose
levels were significantly different in all subgroups. The total insulin amount in
the GIGT and GD subgroups is quite similar to or greater than the controls, but
with a significant reduction of the insulin-glucose ratio. In GD also an absolute
deficiency of insulin rise at 30 min during the glucose load, as in subjects with
Type 2 diabetes mellitus (T2DM), was observed. The behaviour of these parameters
in obese pregnant women seems to be similar, even though with some significant
differences: in these subjects, there is a less clear-cut differentiation among
all subgroups, and the appearance of gestational diabetes is not accompanied by a
significant decrease of insulin secretion at 30 min. Our data seem to demonstrate
that insulin resistance with an inadequate hyperinsulinaemia is a common factor
for the alterations of carbohydrate metabolism during pregnancy. Only in the non
obese patients with gestational diabetes, is there an absolute defect of early
insulin response to the glucose load, as it is seen in T2DM.
PMID- 10782753
TI - Growth hormone and IGF-I in diabetic children with and without microalbuminuria.
AB - In order to evaluate the relationship between urinary GH, urinary IGF-I and
plasma IGF-I levels and presence of incipient diabetic nephropathy in paediatric
age, we studied fifty (25 male and 25 female) prepubertal patients with insulin
dependent diabetes mellitus (T1DM). The patients were subdivided into two groups
according to the presence of persistent microalbuminuria defined as albumin
excretion rate (AER) >20 microg/min in at least 5 urine collections in the 6
months prior to the beginning of the study: Group A: 18 patients with
microalbuminuria; Group B: 32 patients without microalbuminuria. A group of 20
healthy subjects, sex-, age- and pubertal stage-matched, served as control. No
difference was observed between the urinary output of IGF-I and GH and plasma IGF
I values between normoalbuminuric and control subjects (normoalbuminuric vs
controls: urinary GH: mean+/-SD 7.9+/-0.7 ng/day vs 8.1+/-0.6; urinary IGF-I:
178.3+/-19.7 ng/day vs 175.5+/-20.3; plasma IGF-I: 203.9+/-31.2 ng/ml vs 199.4+/
43.2), but a significant difference was observed between the urinary output of
IGF-I and GH and plasma IGF-I levels between microalbuminuric patients and
normoalbuminuric and controls (microalbuminuric subjects: urinary GH: 13.1+/-1.4
p<0.01; urinary IGF-I: 451.3+/-45.9 p<0.001; plasma IGF-I: 326.5+/-63.2 p<0.01).
Moreover, plasma IGF-I, urinary GH and urinary IGF-I were not significantly
associated with microalbuminuria, while plasma IGF-I levels were positively
related to glomerular filtration rate (GFR) (p<0.05). In conclusion, our study
demonstrates that microalbuminuric patients have higher levels of urinary IGF-I,
urinary GH, plasma IGF-I than normoalbuminuric diabetic subjects. These data
support the hypothesis that IGF-I can have a role in the changes of renal
function observed in patients with persistent microalbuminuria.
PMID- 10782754
TI - Effects of acarbose treatment in Type 2 diabetic patients under dietary training:
a multicentre, double-blind, placebo-controlled, 2-year study.
AB - This 24-months, placebo-controlled, double-blind, randomised, group comparison
study investigated the effect of acarbose vs placebo for improving metabolic
control in patients with Type 2 diabetes under dietary training insufficiently
controlled by diet alone. Patients randomised to acarbose had their dose
increased in a stepwise manner to week 5. From week 5 onwards, they received 100
mg three times daily. This incremental dosing scheme was matched in the placebo
group. All patients received specialist, intensive, continuous dietary training
and counselling throughout the 2 yr of the study. Of the 74 patients randomised,
60 were included in the per-protocol analysis (28 receiving acarbose; 32
receiving placebo). HbA1c was the primary target variable. Per-protocol analysis
found that, after 24 months, the mean difference in HbA1c relative to baseline
value was -1.71+/-1.6% in the acarbose group and -0.82+/-1.1% in the placebo
group. End-point values were 6.85+/-1.7% in the acarbose group and 7.41+/-1.1% in
the placebo group. This difference between acarbose and placebo was statistically
significant (p=0.02). Patients were defined as responders if they did not require
additional treatment with an antidiabetic agent during the study. The responder
rate under acarbose therapy was 89%, compared with 47% for placebo (p=0.0005).
Acarbose-treated responders improved their HbA1c level to 6.45+/-0.82% after 24
months. The efficacy of acarbose was consistent throughout the study; decreasing
efficacy was not evident. The results demonstrate the efficacy of acarbose for
improving metabolic control in patients with Type 2 diabetes, even when such
patients receive good dietary treatment and counselling.
PMID- 10782755
TI - Hyperuricaemia in Type 2 diabetes mellitus.
AB - This study was undertaken to find the significant parameters associated with
hyperuricaemia in patients with Type 2 diabetes, and hence to determine if
hyperuricaemia is associated with poor control of diabetes or increased coronary
heart disease. All the diabetic patients seen at a Family Medicine Teaching
Clinic within the period January to September 1997 were recruited into the study.
In 273 Type 2 diabetics, serum uric acid was analysed against basic demographic
data (age, sex, smoking and alcohol habits, body mass index, number of years
since the diagnosis of diabetes), present medications, control of diabetic state
(attending physician's estimation of the patient's diet compliance, fasting serum
sugar, HbA1c), and complications (serum creatinine, total cholesterol,
triglyceride, urine proteinuria, retinopathy, last blood pressure readings,
history of hypertension, coronary heart disease, stroke). Serum uric acid was
significantly associated with body mass index, history of hypertension, serum
triglyceride and serum creatinine, but was not related to coronary heart disease,
stroke or control of the diabetic state. Female diabetics were more likely to
have elevated uric acid. There is not enough evidence for monitoring serum uric
acid or for intervention to lower asymptomatic hyperuricaemia in Type 2 diabetic
patients.
PMID- 10782757
TI - On grassroots activism and health policy: a case study.
PMID- 10782756
TI - Calcium antagonists and cardiovascular risk in patients with hypertension and
Type 2 diabetes mellitus: evidence from the PIUMA Study. Progetto Ipertensione
Umbria Monitoraggio Ambulatoriale.
AB - We conducted a retrospective analysis of all subjects with essential hypertension
and Type 2 diabetes mellitus enrolled in the PIUMA (Progetto Ipertensione Umbria
Monitoraggio Ambulatoriale) registry, in order to evaluate whether the use of
calcium antagonists is associated with an increase in cardiovascular risk in
these subjects. One hundred and sixty-four consecutive subjects with no previous
cardiovascular morbid events and coexistence of essential hypertension and Type 2
diabetes mellitus were studied before therapy and followed for up to 12 years
(mean 5). There were periodical contacts with family doctors and patients in
order to ascertain the occurrence of major cardiovascular events. The use of
calcium antagonists that preceded the event was considered for classification.
None of the patients was lost to follow-up. At entry, the patients who were
subsequently given calcium antagonists (n=50) had a higher clinical (174/98 vs
161/92 mmHg, both p<0.01) and 24-hr ambulatory blood pressure (150/90 vs 141/84
mmHg, both p<0.01) than those who were not. During follow-up there were 53 major
cardiovascular morbid events (6.46 per 100 person-years). The rate of total
cardiovascular events [5.6 vs 6.8 events per 100 person-years, relative risk 0.88
(95% CI: 0.47-1.61)] and that of cardiac events [4.0 vs 3.3 events per 100 person
years, relative risk 1.33 (95% CI: 0.62-2.89)] did not differ between users of
calcium antagonists and non-users. The use of angiotensin converting enzyme
inhibitors (n=66) was unrelated to the risk of cardiovascular events (relative
risk 1.24, 95% CI: 0.71-2.16). In a Cox multivariate analysis, only age (p=0.002)
and 24-hr pulse pressure (p=0.04) were independent predictors of cardiovascular
events. In conclusion, this cohort study does not support the hypothesis that use
of calcium antagonists is associated with an excess risk of adverse
cardiovascular events in uncomplicated subjects with essential hypertension and
Type 2 diabetes mellitus.
PMID- 10782758
TI - Comparison of student outcomes and preferences in a traditional vs. World Wide
Web-based baccalaureate nursing research course.
AB - The purpose of this project was to compare student outcomes in an undergraduate
research course taught using both World Wide Web-based distance learning
technology and traditional pedagogy. Reasons given for enrolling in the
traditional classroom section included the perception of increased opportunity
for interaction, decreased opportunity to procrastinate, immediate feedback, and
more meaningful learning activities. Reasons for selecting the Web group section
included cost, convenience, and flexibility. Overall, there was no significant
difference in examination scores between the two groups on the three multiple
choice examinations or for the course grades (t = -.96, P = .343). Students who
reported that they were self-directed and had the ability to maintain their own
pace and avoid procrastination were most suited to Web-based courses. The Web
based classes can help provide opportunities for methods of communication that
are not traditionally nurtured in traditional classroom settings. Secondary
benefits of the World Wide Web-based course were to increase student confidence
with the computer, and introduce them to skills and opportunities they would not
have had in the classroom. Additionally, over time and with practice, student's
writing skills improved.
PMID- 10782759
TI - An experience of peer mentoring with student nurses: enhancement of personal and
professional growth.
AB - This article discusses the importance of peer mentoring in nursing education. The
current literature is reviewed and areas for further research are identified.
Most specifically, the article explores the results of a recent research study
conducted at Southern Cross University in Australia. The research investigated
the relationship between personal and professional growth and peer mentoring with
a group of women nurses. Seven nurses participated in this qualitative research
project. Six of the participants were student nurses enrolled in an undergraduate
nursing degree and the seventh participant was the degree program coordinator.
The research was conducted over a 12-week period and was located in critical
paradigm. The research methods used were reflective journaling and interviewing.
The results indicated that the process of peer mentoring in nursing education
demonstrated a strong relationship to personal and professional growth for all of
the participants. Characteristics of the peer mentoring process such as shared
learning, shared caring, reciprocity, commitment to each other's personal and
professional growth, and friendship, are discussed.
PMID- 10782760
TI - Experiences and comfort with culturally diverse groups in undergraduate pre
nursing students.
AB - A sample of approximately 200 undergraduate students beginning their nursing
education responded to questionnaire items concerning experience and levels of
comfort working with diverse client groups. Students reported little discomfort
with racial/ethnic groups, but reported they would have considerable difficulty
working with lesbian, gay, or bisexual clients, and patients with human
immunodeficiency virus. Their reasons for discomfort were examined.
PMID- 10782761
TI - Does constructivist epistemology have a place in nurse education?
AB - Nursing students who undertake the bachelor of nursing degree program are adults,
many of whom are considered mature students. As such, they have significant life
experiences and a vast amount of knowledge that has been acquired both formally
and informally. Much of formal education historically, and even today, is content
and curriculum driven, and teacher focused. Constructivist epistemology offers an
alternative to traditional pedagogy in that it is student focused and considers
previous learning done by the students as a foundation upon which to modify,
build, and expand new knowledge. Constructivism also appears to be congruent with
adult education theory and therefore offers great potential for the enhancement
of self-directed learning. It enhances empowered learning because of the
consideration of prior knowledge and the ownership of learning by the students.
Implicit in this is the development of metacognitive skills that are an important
facet of active and self-directed learning. As a result of undergraduate learning
within a constructivist framework, there are likely to be benefits for nurses in
the practice setting for making the transition from inexperienced to experienced
practitioners. Constructivist learning frameworks provide learning skills that
enhance knowledge acquisition with understanding.
PMID- 10782762
TI - Domestic violence and the nursing curriculum: tuning in and tuning up.
AB - Domestic violence is a major health, social, and criminal justice problem in the
United States. Although not confined to women, it is a growing concern of women
and those who care for women. Nurses are often the first health care provider
with whom the battered woman and her family interact. Reports of several studies
indicate educational preparation of nurses is inadequate to assure sensitive,
quality, and effective nursing care to those who have survived domestic violence.
One purpose of this qualitative study was to identify and describe the essential
knowledge and skills needed by nurses to provide competent, sensitive care.
Interviews were conducted with 13 informants who were considered experts in
violence-related care. Their responses were analyzed for categories of response
and themes related to their feelings about domestic violence and the essential
knowledge and skills nurses need to provide appropriate care. Findings provide
data that can form the empirical bases for review of current curriculum content
and strategies, indicate needed revisions, and serve as a framework for future
curriculum development.
PMID- 10782763
TI - Students' collaborative clinical experience.
PMID- 10782764
TI - The National Council Licensure Examinations/differential item functioning
process.
AB - The National Council of State Boards of Nursing, Inc., is committed to
administering licensure examinations that test minimum, essential entry level
nursing competence. The item development process used by the National Council
includes extensive procedures that are designed to minimize the possibility that
test items contain factors unrelated to the purpose of the examination. This
article described one of those procedures, known as the NCLEX DIF process. The
NCLEX DIF process combines a statistical review with a judgmental review to
detect items that may be measuring other than the intended construct. National
Council Licensure Examinations are closely scrutinized to ensure fairness and
validity. While it may not be possible to conduct DIF analyses on classroom test
items, nursing educators should endeavor to review all items for potential item
bias by examining them for stereotypical and sensitive material. Guidelines to
assist the nursing educator in the review process to prevent item bias are
available (Wendt, Holz, Worcester, 1996; Shepard, 1982).
PMID- 10782765
TI - Social work graduate students' beliefs regarding responsibilities of professional
nursing.
PMID- 10782766
TI - Is peripheral spinal cord hypointensity a sign of venous hypertensive myelopathy?
PMID- 10782767
TI - Comparisons between carotid duplex sonography and cerebral angiography in
assessing the degree of carotid stenosis.
PMID- 10782768
TI - Applying functional MR imaging to brain-behavioral research: can we do better
than simple clinical measures?
PMID- 10782770
TI - Absence of selective deep white matter ischemia in chronic carotid disease: a
positron emission tomographic study of regional oxygen extraction.
AB - BACKGROUND AND PURPOSE: Deep white matter may be the location of an internal
arterial border zone. The purpose of this study was to determine whether the deep
white matter was subject to a greater degree of ischemia than was the cortex
among patients with chronic carotid occlusion. METHODS: Thirty-six patients with
carotid occlusion and structurally normal deep white matter were studied with
positron emission tomography. Measurements of oxygen extraction fraction were
made in superficial (cortical and subcortical) regions in the middle cerebral
artery territory and in deep white matter (internal border zone) regions. The
presence of selective ischemia of the deep white matter was assessed by the ratio
of deep white matter:superficial oxygen extraction fraction. Ipsilateral
hemispheric ratios among patients were assessed as a group as compared with
contralateral hemispheric ratios and as compared with normal hemispheric ratios
from 15 control volunteers. RESULTS: Mean deep white matter to superficial oxygen
extraction fraction ratios (+/-95% confidence limits) were 0.99 (+/-0.07), 1.01
(+/-0.06), and 1.02 (+/-0.08) for ipsilateral, contralateral, and normal
hemispheres, respectively. No statistically significant difference was found
between ipsilateral and contralateral (P = .691) or normal hemispheres (P = .68),
nor was any statistically significant difference found when the analysis was
limited to patients with increased superficial oxygen extraction fraction (n =
9). Individual deep white matter:superficial ratios were within the normal range
for all patients. CONCLUSION: Normal deep white matter among patients with
carotid occlusion is not subject to a greater degree of ischemia than is the
overlying cortex. It is unlikely that deep white matter infarctions observed
among patients with carotid occlusion are owing to chronic selective hemodynamic
compromise occurring at an internal arterial border zone.
PMID- 10782769
TI - Subcortical ischemic vascular dementia: assessment with quantitative MR imaging
and 1H MR spectroscopy.
AB - BACKGROUND AND PURPOSE: Subcortical ischemic vascular dementia is associated with
cortical hypometabolism and hypoperfusion, and this reduced cortical metabolism
or blood flow can be detected with functional imaging such as positron emission
tomography. The aim of this study was to characterize, by means of MR imaging and
1H MR spectroscopy, the structural and metabolic brain changes that occur among
patients with subcortical ischemic vascular dementia compared with those of
elderly control volunteers and patients with Alzheimer's disease. METHODS:
Patients with dementia and lacunes (n = 11), cognitive impairment and lacunes (n
= 14), and dementia without lacunes (n = 18) and healthy age-matched control
volunteers (n = 20) underwent MR imaging and 1H MR spectroscopy. 1H MR
spectroscopy data were coanalyzed with coregistered segmented MR images to
account for atrophy and tissue composition. RESULTS: Compared with healthy
control volunteers, patients with dementia and lacunes had 11.74% lower N
acetylaspartate/creatine ratios (NAA/Cr) (P = .007) and 10.25% lower N
acetylaspartate measurements (NAA) in the cerebral cortex (P = .03). In white
matter, patients with dementia and lacunes showed a 10.56% NAA/Cr reduction (P =
.01) and a 12.64% NAA reduction (P = .04) compared with control subjects. NAA in
the frontal cortex was negatively correlated with the volume of white matter
signal hyperintensity among patients with cognitive impairment and lacunes (P =
.002). Patients with dementia, but not patients with dementia and lacunes, showed
a 10.33% NAA/Cr decrease (P = .02) in the hippocampus compared with healthy
control volunteers. CONCLUSION: Patients with dementia and lacunes have reduced
NAA and NAA/Cr in both cortical and white matter regions. Cortical changes may
result from cortical ischemia/infarction, retrograde or trans-synaptic injury (or
both) secondary to subcortical neuronal loss, or concurrent Alzheimer's
pathologic abnormalities. Cortical derangement may contribute to dementia among
patients with subcortical infarction.
PMID- 10782771
TI - Evaluation of carotid stenosis by angiography: potential bias toward
overestimated measurements introduced by prior interpretation of Doppler
sonograms.
AB - BACKGROUND AND PURPOSE: Doppler sonography of the carotid arteries is routinely
performed before catheter angiography, and its results may bias the subsequent
interpretation of angiograms. We attempt to establish that Doppler sonography may
show an exaggerated degree of carotid stenosis, introducing bias to the
evaluation of carotid stenosis by subsequent catheter angiography. METHODS:
Angiograms of the carotid arteries obtained to evaluate potential carotid
stenosis in patients who had undergone Doppler sonography of the carotid arteries
were retrospectively reviewed (from 1993 to 1998). Readers who were blinded to
the previous interpretations of the angiography and Doppler sonography results
measured carotid stenosis. The results of Doppler sonography of the carotid
arteries were not re-evaluated. Based on the original Doppler sonograms, stenoses
were categorized as normal/mild (<30%), moderate (30-59%), severe (60-79%), and
critical (80-99%). Within these categories, the differences between the original
percent stenosis, as determined by angiography, and the blinded measurements were
determined. RESULTS: A total of 106 patients with angiographically measurable
stenoses in 128 vessels were identified. The difference between the blinded
readers was 3% (+/-8%), with no category statistically different from the other.
The difference between original and remeasured stenoses in carotid arteries in
the Doppler categories were as follows: mild stenosis, 2% (+/-9%); moderate
stenosis, 6% (+/-15%); severe stenosis, 8% (+/-15%); and critical stenosis, 22%
(+/-12%). A significant overestimation occurred in the severe (P < .05) and
critical (P < .0001) stenosis categories. One third of patients with stenoses in
the severe or critical Doppler category had significant stenoses on the original
angiograms that were less than 60%, according to blinded remeasurement.
CONCLUSION: Doppler sonography of the carotid arteries has the potential to bias
the subsequent interpretation of catheter angiography. Care must be taken to
measure stenosis accurately, using strict criteria to determine the potential
benefit of carotid endarterectomy for the individual patient and to ensure that
the criteria for Doppler sonography of the carotid arteries are based on accurate
catheter angiography measurements.
PMID- 10782772
TI - A standardized method for measuring intracranial arterial stenosis.
AB - BACKGROUND AND PURPOSE: Atherosclerosis of the major intracranial arteries is an
important cause of ischemic stroke. We established measurement criteria to assess
percent stenosis of a major intracranial artery (carotid, middle cerebral,
vertebral, basilar) and determined the interobserver/intraobserver agreements and
interclass/intraclass correlations of these measurements. METHODS: We defined
percent stenosis of an intracranial artery as follows: percent stenosis = [(1 -
(D(stenosis)/D(normal)))] x 100, where D(stenosis) = the diameter of the artery
at the site of the most severe stenosis and D(normal) = the diameter of the
proximal normal artery. If the proximal segment was diseased, contingency sites
were chosen to measure D(normal): distal artery (second choice), feeding artery
(third choice). Using a hand-held digital caliper, three neuroradiologists
independently measured D(stenosis) and D(normal) of 24 stenotic intracranial
arteries. Each observer repeated the readings 4 weeks later. We determined how
frequently two observers' measurements of percent stenosis of each of the 24
diseased arteries differed by 10% or less. RESULTS: Among the three pairs of
observers, interobserver agreements were 88% (observer 1 versus observer 2), 79%
(observer 1 versus observer 3), 75% (observer 2 versus observer 3) for the first
reading and were 75% (observer 1 versus observer 2), 100% (observer 1 versus
observer 3), and 71% (observer 2 versus observer 3) for the second reading.
Intraobserver agreement for each of the observers was 88%, 83%, and 100%.
Interclass correlation was 85% (first reading) and 87% (second reading).
Intraclass correlation was 92% (first and second readings combined). CONCLUSION:
This method shows good interobserver and intraobserver agreements for the
measurement of intracranial stenosis of a major artery. If validated in
subsequent studies, this method may serve as a standard for the measurement of
percent stenosis of an intracranial artery.
PMID- 10782774
TI - Correlation between choline level measured by proton MR spectroscopy and Ki-67
labeling index in gliomas.
AB - BACKGROUND AND PURPOSE: The clinical relevance of proton MR spectroscopy needs
further clarification as to its usefulness and limitations. The purpose of this
study was to investigate the correlation between the semiquantitative choline
containing compound level (Cho value) measured by MR spectroscopy and the Ki-67
labeling index in gliomas. METHODS: Localized proton spectra were obtained in 26
consecutive patients with glioma who subsequently underwent surgery for tumor
removal. Metabolic values in the spectra were measured semiquantitatively using
an external standard of reference. The Ki-67 labeling index was measured in the
surgical specimen. Because the semiquantitative metabolic values may be affected
by tissue components included in the spectroscopic voxel, the MR imaging
appearance of the voxel within the tumor was classed as homogeneous or
heterogeneous through visual evaluation of the presence of necrosis, cyst,
hemorrhage, and calcification, and pattern of enhancement. RESULTS: We found a
strong linear correlation between the Cho value and the Ki-67 labeling index in
the 18 homogeneous gliomas, but no correlation was found in the eight
heterogeneous gliomas, which turned out to be malignant. CONCLUSION: The
semiquantitative Cho value is a reliable predictor of proliferative activity of
gliomas when the tumor appears homogeneous on MR images.
PMID- 10782773
TI - MR imaging and localized proton spectroscopy of the precentral gyrus in
amyotrophic lateral sclerosis.
AB - BACKGROUND AND PURPOSE: In the search for a diagnostic test for amyotrophic
lateral sclerosis (ALS), especially upper motor neuron (UMN) involvement, MR
imaging and proton spectroscopy techniques have each received attention, but
their findings have not been correlated. The purpose of this study was to
identify relationships among the results of current techniques, taking into
account the severity of clinical UMN disease, so that objective measures of the
pathogenesis of ALS may be established. METHODS: Eighteen subjects with
clinically diagnosed ALS and 12 healthy volunteers underwent MR imaging of the
brain and localized proton MR spectroscopy. Water-suppressed spectra from the
left precentral gyrus and from the left cuneus gyrus were analyzed with the
LCModel method, yielding concentrations for N-acetyl (NA), total creatine (Cr),
choline (Cho), glutamate (Glu), glutamine (Gin), and myo-inositol (Ins) metabolic
substrates. Signal intensities of the precentral gyrus on T2-weighted images were
assessed qualitatively in a blinded fashion. RESULTS: For the precentral gyrus,
mean Cho (1.3 mM) and Ins (3.25 mM) for the ALS group were significantly
increased. After adjustment for Cr covariance, mean Glu (5.08 mM) and NA (6.31
mM) were decreased. For the cuneus gyrus, no difference in metabolite
concentrations between groups was observed. Trend analysis of the precentral
gyrus metabolite concentrations revealed significant increases in Cho and Ins and
decreases in NA and Glu with respect to the severity of clinical UMN signs.
Metabolic changes were greater in the subset of ALS patients with precentral
gyrus signal changes on imaging, and significantly increased Ins was associated
with cortical hypointensity on fast spin-echo images. CONCLUSION: Mean metabolite
concentrations determined from precentral gyrus spectra reflect clinical and
pathologic changes that occur in ALS. Imaging findings, while related to the
spectral and clinical results, are not specific to ALS.
PMID- 10782775
TI - MR imaging- and MR spectroscopy-revealed changes in meningiomas for which
embolization was performed without subsequent surgery.
AB - We describe our experience with follow-up MR imaging and MR spectroscopy in two
patients after embolization of meningiomas without subsequent surgery. In both
patients there was a marked reduction in tumor size and a decrease in contrast
enhancement associated with spectroscopic signs of fatty degeneration. We did not
observe regrowth; however, in one patient with incomplete angiographic
devascularization, residual vital tumor tissue was seen at follow-up
examinations.
PMID- 10782776
TI - Highly active antiretroviral therapy for patients with AIDS dementia complex:
effect on MR imaging findings and clinical course.
AB - BACKGROUND AND PURPOSE: Recent studies have reported the clinical improvement in
patients with AIDS treated with a combination of antiretroviral regimens. The
purpose of our study was to describe the effects of highly active antiretroviral
therapy on MR images in patients with HIV encephalopathy and to compare the
clinical course with follow-up neuroimaging studies. METHODS: Initial and follow
up MR imaging findings are described in four patients with AIDS dementia complex
at baseline and after antiretroviral therapy, and correlated with clinical and
immunologic findings. RESULTS: Initial MR imaging revealed white matter signal
abnormalities on long-TR images without mass effect and without enhancement on
postcontrast images, consistent with HIV encephalopathy. Lesions were located in
the basal ganglia and posterior fossa in two patients. All four patients showed
progression of white matter disease on the first follow-up MR scan (mean, 6
months). On subsequent scans, regression was seen in three patients and
stabilization of white matter disease was observed in one patient. Increases in
CD4+ count and decreases in viral load below the limit of quantification were
present in all patients. CONCLUSION: Although our patient population was small,
the results suggest that disease regression in patients with AIDS dementia
complex after treatment with highly active antiretroviral therapy can be
characterized and monitored by MR imaging.
PMID- 10782777
TI - Improved detection of intraventricular cysticercal cysts with the use of three
dimensional constructive interference in steady state MR sequences.
AB - BACKGROUND AND PURPOSE: Before the advent of MR imaging, intraventricular cysts
were difficult to diagnose noninvasively. Among the invasive procedures used were
contrast ventriculography and CT ventriculography. MR imaging, with its
multiplanar imaging capabilities, excellent depiction of tissue contrast, and
versatile parameters, is an important tool in the assessment of intraventricular
cystic lesions. We investigated the role of three-dimensional constructive
interference in steady state (3D-CISS) MR sequences in the evaluation of
intraventricular cysticercal cysts. METHODS: The study group comprised 11
patients with intraventricular cysticercal cysts. MR studies included spin-echo
(SE) T1-weighted, turbo-SE T2-weighted, and 3D-CISS sequences. All images were
obtained on a superconducting 1.5-T MR unit. The routine and 3D-CISS sequences
were reviewed and interpreted separately by two neuroradiologists. RESULTS: All
patients underwent surgery for excision of intraventricular cysticercal cysts.
Eight patients had cysts in the fourth ventricle, two in the lateral ventricle,
and one in the third ventricle. SE T1-weighted images showed the cystic wall in
nine cases, the scolex in four, and the cystic fluid in two. Turbo-SE T2-weighted
images showed the cystic wall and scolex in three and four cases, respectively.
The routine sequences did not show the scolex, cystic wall, or cystic fluid
together in any of the 11 patients. 3D-CISS images showed the scolex in all 11
patients and the cystic wall and cystic fluid in eight patients each. In seven of
the 11 patients, 3D-CISS images showed the scolex, cystic wall, and fluid
together. CONCLUSION: The 3D-CISS sequence is more sensitive and specific than
routine SE sequences in the diagnosis of intraventricular cysticercal cysts.
PMID- 10782778
TI - Pituitary hypoplasia in patients with a mutation in the growth hormone-releasing
hormone receptor gene.
AB - BACKGROUND AND PURPOSE: Several anatomic abnormalities of the pituitary gland
have been described as occurring in association with congenital growth hormone
deficiency, including hypoplasia of the adenohypophysis, truncation of the
pituitary stalk, and ectopia of the neurohypophysis. Their pathogenesis, however,
is obscure. Normal pituitary development is dependent on the sequential
expression of a series of ontogenetic factors. Growth hormone-releasing hormone
(GHRH) is known to stimulate somatotroph proliferation, and a dwarf mouse model
with a mutant GHRH receptor, the "little mouse," has a small anterior pituitary
due to hypoplasia of the somatotrophs. We recently described the human homolog of
the little mouse (dwarfism of Sindh), caused by a homozygous nonsense mutation in
the GHRH receptor gene in a Pakistani kindred. We investigated MR imaging
characteristics to gain information regarding the potential role of GHRH in human
pituitary organogenesis. METHODS: MR images of the head were obtained of four
affected male patients (age range, 22-29 years). Maximal anterior pituitary
dimensions were determined from sagittal and coronal images, and pituitary
volumes were estimated from cubic and ellipsoid formulae. The measurements were
compared with normative values matched for age and sex. RESULTS: The
adenohypophysis was small in each of the four patients. The maximal height for
the anterior pituitary was 3 mm in three patients and 2 mm in one (mean +/- SD,
2.75 +/- 0.5 mm), which is significantly (P < .001) less than the expected height
of 5.6 +/- 1.0 mm for men in this age group. Estimates of anterior pituitary
volume in the patients ranged from 75 to 124 mm3 (104 +/- 21 mm3), which
corresponds to 35% to 52% of the normal mean volume corrected for small head size
(P < .005). No other cranial abnormalities were identified. CONCLUSION: We
describe significant hypoplasia of the adenohypophysis occurring in four dwarfs
with a nonsense mutation in the GHRH receptor. In addition to isolated growth
hormone deficiency and severe dwarfism, affected patients have anterior pituitary
hypoplasia, presumably due to somatotroph maldevelopment. Resistance to GHRH
explains the hypoplasia of the adenohypophysis--a feature that contributes to
growth hormone deficiency in this syndrome. This is one of the few instances in
which the molecular basis of pituitary dysmorphogenesis has been identified.
PMID- 10782779
TI - Adrenocorticotropic hormone-dependent Cushing's syndrome: sensitivity and
specificity of inferior petrosal sinus sampling.
AB - BACKGROUND AND PURPOSE: Determining the cause of Cushing's syndrome can be
difficult. Bilateral inferior petrosal sinus (IPS) sampling after ovine
corticotropin-releasing hormone (oCRH) stimulation is an established technique
for the differentiation of pituitary from nonpituitary sources of
adrenocorticotropic hormone (ACTH) production. The purpose of this study was to
review our experience to determine the sensitivity and specificity of bilateral
IPS sampling. METHODS: Between January 1990 and February 1997, 92 patients
underwent 94 IPS sampling procedures. Indications for these patients with
Cushing's syndrome included no discrete lesion on MR images or CT scans, a
discrete lesion present on images but equivocal peripheral ACTH sampling after
oCRH stimulation, and persistent Cushing's syndrome after trans-sphenoidal
surgery. RESULTS: IPS sampling yielded six false-negative results and one false
positive result, manifesting an overall sensitivity of 92.2% and a specificity of
90.0% for detection of a pituitary source of ACTH after oCRH stimulation.
Microadenoma lateralization by IPS sampling after oCRH stimulation agreed with
the surgical location in 70.0% of the patients. The technical success rate of
initial (presampling) bilateral IPS catheterization was 93.6%. Two serious
complications occurred and consisted of a venous subarachnoid hemorrhage and a
lower extremity deep venous thrombosis. CONCLUSION: Bilateral IPS sampling after
oCRH stimulation is helpful in the evaluation of ACTH-dependent Cushing's
syndrome. False-negative results, however, suggest that the possibility of a
pituitary source must still be considered when no response to oCRH is documented.
Interpetrosal ACTH gradient alone is not sufficient to lateralize the tumor
reliably.
PMID- 10782780
TI - Structural changes of the substantia nigra in Parkinson's disease as revealed by
MR imaging.
AB - BACKGROUND AND PURPOSE: The possibility of using MR imaging as a sensitive marker
of the structural changes in Parkinson's disease has been a long-sought goal. We
describe a new method for imaging and quantifying the morphologic changes of the
substantia nigra in Parkinson's disease and compare radiologic findings with
clinical evaluation. METHODS: Using a combination of two MR imaging inversion
recovery pulse sequences, the substantia nigra was imaged in six patients with
Parkinson's disease and six age-related control participants. A radiologic index
was defined and used to quantify the signal changes that were observed in the
patients. The radiologic index was compared with clinical scores obtained from
the Unified Parkinson's Disease Rating Scale. RESULTS: The images showed loss of
signal in a lateral-to-medial gradient in cases of Parkinson's disease,
corresponding to the known neuropathologic pattern of degeneration. The
radiologic index was highly correlated with the Unified Parkinson's Disease
Rating Scale score, and there was no overlap in radiologic indices between the
patient and the control groups (P < .00005). CONCLUSION: This study suggests that
MR imaging is sensitive to structural changes in even the earliest cases of
Parkinson's disease, thereby indicating the potential for detecting
presymptomatic disease. Furthermore, a radiologic measure has been defined that
correlates with the conventional clinical measure of disease severity. Therefore,
MR imaging could prove to be a sensitive biological marker for objective staging
of the disease.
PMID- 10782781
TI - Isolated demyelinating syndromes: comparison of different MR imaging criteria to
predict conversion to clinically definite multiple sclerosis.
AB - BACKGROUND AND PURPOSE: Various authors have developed criteria to classify MR
imaging findings that suggest the possibility of multiple sclerosis. The purpose
of this study was to evaluate and compare the capacity of three sets of MR
imaging criteria for predicting the conversion of isolated demyelinating
syndromes to clinically definite multiple sclerosis. METHODS: Seventy patients
with clinically isolated neurologic symptoms suggestive of multiple sclerosis
were prospectively studied with MR imaging. The MR imaging findings were
evaluated by two independent neuroradiologists who were blinded to clinical
follow-up data. Based on the clinical outcome at follow-up (presence of a second
attack that established clinically definite multiple sclerosis), the sensitivity,
specificity, accuracy, positive predictive value, and negative predictive value
of the criteria proposed by Paty et al, Fazekas et al, and Barkhof et al were
calculated. RESULTS: Clinically definite multiple sclerosis developed in 22 (31%)
patients after a mean follow-up time of 28.3 months. The criteria proposed by
Paty et al and those proposed by Fazekas et al showed identical results:
sensitivity, 86%; specificity, 54%; accuracy, 64%; positive predictive value,
46%; and negative predictive value, 89%. The criteria proposed by Barkhof et al
showed the following: sensitivity, 73%; specificity, 73%; accuracy, 73%; positive
predictive value, 55%; and negative predictive value, 85%. CONCLUSION: The four
dichotomized MR imaging parameters proposed by Barkhof et al are more specific
and accurate than the criteria proposed by Paty et al or Fazekas et al for
predicting conversion to clinically definite multiple sclerosis.
PMID- 10782782
TI - MR digital subtraction angiography of cerebral arteriovenous malformations.
AB - BACKGROUND AND PURPOSE: Although phase-contrast MR angiography provides some
information regarding hemodynamics of cerebral arteriovenous malformations
(AVMs), most conventional MR angiographic techniques have not been helpful in
this respect. We attempted to determine the value of MR digital subtraction
angiography (DSA) in assessing AVM hemodynamics. METHODS: We developed an MR DSA
technique by combining rapid thick-section T1-weighted imaging with a bolus
injection of contrast material. The temporal resolution was 0.56 to 0.61 seconds
per scan. MR DSA images obtained from 14 patients with AVMs were reviewed.
Anatomic depiction of each component of the AVM was rated using a four-point
grading scale (excellent = 3, good = 2, fair = 1, poor = 0) to compare
conventional vs MR angiograms. RESULTS: We were able to obtain serial images in
which passage of contrast material was evident within the AVM, although the
sequence we used allowed images to be obtained in only one projection. The
average score for feeders, nidi, and drainers was 1.6, 2.4, and 2.3,
respectively, with an overall average of 2.1. CONCLUSION: The spatial resolution
of our technique may fall below the level needed for identification of small
vascular components of an AVM. Additionally, the limited slab may restrict
application of the technique to assessment of large or very small AVMs. MR DSA,
however, can show the hemodynamics of AVMs and may serve as a supplement to
conventional MR imaging in the diagnosis of cerebral AVMs.
PMID- 10782783
TI - Carotid-cavernous fistulas: diagnosis with spiral CT angiography.
AB - Four cases in which the diagnosis of carotid-cavernous fistula was made by using
CT angiography are illustrated. The diagnosis was confirmed by digital
subtraction angiography in all four instances. To our knowledge, this is the
first report of the CT angiographic appearance of carotid-cavernous fistulas.
PMID- 10782784
TI - High uptake of 123I-metaiodobenzylguanidine related to olfactory neuroblastoma
revealed by single-photon emission CT.
AB - We studied a case of olfactory neuroblastoma by noting 123I
metaiodobenzylguanidine (MIBG) uptake revealed by single-photon emission CT
(SPECT). MR imaging revealed an enhancing tumor extending from the left nasal
cavity to the bilateral anterior frontal cranial fossae. SPECT revealed high 123I
MIBG uptake in the enhancing tumor. SPECT-revealed 123I-MIBG uptake appears to be
clinically useful for distinguishing olfactory neuroblastomas from other tumors,
especially suprasellar meningiomas.
PMID- 10782785
TI - The adult radiographic shuntogram.
AB - We describe the adult radiographic shuntogram, a simple method to evaluate the
function and patency of a ventriculoperitoneal or ventriculoatrial shunt. The
procedure involves placing contrast material into the valve of a shunt system and
following the flow for appropriate clearing of contrast agent from the shunt
tubing. Twenty-three studies were obtained in 15 patients in whom shunt
malfunction was suspected. The method can be used to establish valve malfunction,
ventricular or distal catheter obstruction, and peritoneal encystment.
PMID- 10782786
TI - Percutaneous transluminal angioplasty and stenting of the proximal vertebral
artery for symptomatic stenosis.
AB - BACKGROUND AND PURPOSE: Percutaneous transluminal angioplasty (PTA) for
significant stenosis involving the origin of the vertebral artery is now a well
established treatment for selected patients when posterior cerebral arterial
circulation is compromised. Arterial spasm, dissection, and restenosis may occur
in some instances, with subsequent hemodynamic compromise. To prevent these
potential complications, we combined PTA of the vertebral artery with primary
stenting, using coronary stents, in seven patients. We herein present our short-
and intermediate-term results. METHODS: A total of seven lesions affecting the
origin of the vertebral artery were treated by primary trans-stenotic coronary
stent placement. All patients were symptomatic, fulfilling the general criteria
for vertebral artery angioplasty. Patients were followed for up to 36 months
after treatment. RESULTS: All seven lesions were successfully dilated. Residual
stenosis was never greater than 20% in diameter. No perioperative complications
occurred. Clinical follow-up showed immediate resolution or improvement of
symptoms in all patients. One patient's condition deteriorated 15 months after
stent placement because of atheromatous stenosis of the prevertebral segment in
the ipsilateral subclavian artery. CONCLUSION: Stent placement to treat
significant stenosis involving the origin of the vertebral artery is safe and
effective for alleviating symptoms and improving blood flow to the posterior
cerebral circulation. Coronary stent design seems to be particularly well suited
to cover atherosclerotic lesions of the origin of the vertebral artery. The stent
mesh probably prevents elastic recoil and early restenosis after PTA, as it does
in coronary arteries.
PMID- 10782787
TI - Endovascular stenting for carotid artery stenosis: preliminary experience using
the shape-memory- alloy-recoverable-technology (SMART) stent.
AB - We describe our initial clinical experience using the newly available self
expanding, Nitinol, shape-memory-, alloy-recoverable-technology (SMART) stent in
treating carotid artery occlusive disease. Five stents were used in four carotid
arteries in four consecutive patients with carotid stenosis of at least 70%.
Technical success (<20% residual stenosis) was achieved in all cases. No
procedural complications specifically related to use of the SMART stent were
encountered. All patients remained symptom-free, with no evidence of transient
ischemic attacks or new strokes during an average follow-up period of 6 months.
Excellent performance of the SMART stent for the endovascular treatment of
carotid artery stenosis has been shown based on our early experience. Validation
with greater numbers and longer-term follow-up is required. The specific
technical characteristics, potential advantages, and disadvantages of this stent
are discussed and compared with other currently used carotid artery stents.
PMID- 10782788
TI - Occlusion of experimentally created fusiform aneurysms with porous metallic
stents.
AB - BACKGROUND AND PURPOSE: Carotid fusiform aneurysms are most commonly treated with
occlusion of the parent vessel. The purpose of our study was to assess the
effectiveness of self-expanding, cobalt-alloy stents in the ablation of
experimental fusiform aneurysms with preservation of the parent vessel in a
carotid artery model. METHODS: Porous metallic stents were placed endovascularly
along the lengths of experimentally created fusiform aneurysms in the carotid
arteries of dogs; aneurysms were also created in the animals' opposite carotid
arteries to serve as controls. RESULTS: Before stent placement, angiography of
the carotid arteries showed large fusiform aneurysms along the lengths of the
common carotid arteries and complex patterns of flow. Immediately after stent
placement there was disruption of the usual flow patterns within the lumens of
the fusiform aneurysms. The lumen between the wall of the aneurysm and stented
carotid showed stasis of contrast material and blood. Near-complete ablation of
all aneurysms was observed 8 weeks after stent placement. The stented carotid
arteries remained widely patent; control aneurysms and carotid arteries were
patent and unchanged. Histopathologic analysis revealed fibrotic reactive scar
tissue filling the space between the stent wires and outer wall of the fusiform
aneurysm. CONCLUSION: Changing blood flow dynamics within an aneurysm can promote
thrombus formation. The stent promotes stasis and thrombus within the residual
lumen between the stent wall and the outer wall of the aneurysm because its woven
wire mesh interferes with usual blood flow patterns, which then promotes
formation of thrombus and fibrosis within the residual aneurysmal lumen.
PMID- 10782789
TI - Three-dimensional time-of-flight MR angiography in the evaluation of intracranial
aneurysms treated with Guglielmi detachable coils.
AB - BACKGROUND AND PURPOSE: Intravascular treatment of intracranial aneurysms is a
relatively new therapeutic technique and long-term controlled angiographic trials
are needed to assess persistence of aneurysm occlusion. Our purpose was to
evaluate the effectiveness of 3D time-of-flight (3D-TOF) MR angiography as a
noninvasive screening tool in the follow-up of cerebral aneurysms treated with
Guglielmi detachable coils (GDCs). METHODS: Forty-nine patients with 50
intracranial aneurysms previously treated with GDCs were studied with both DSA
and 3D-TOF MR angiography. In 14 cases, a second follow-up examination was
performed, for a total of 64 aneurysms evaluated. In 25 aneurysms, both pre- and
postcontrast MR angiographic studies were obtained. RESULTS: In seven of 64
aneurysms, the MR angiographic studies were considered to be unreliable owing to
the presence of artifacts that obscured part of the parent artery and did not
allow an accurate evaluation of the aneurysm neck. These seven aneurysms,
however, all were shown to be completely occluded at digital subtraction
angiography (DSA). In the remaining 57 aneurysms, DSA revealed complete occlusion
in 39 and the presence of residual patency in 18, whereas MR angiography showed
complete occlusion in 38 and residual patency in 19. Enhanced MR angiography
proved to be useful in evaluating residual patency in large and giant aneurysms
and in better depicting the distal branch arteries. CONCLUSION: Although
artifacts related to the presence of coils are evident on a considerable number
of imaging studies, our findings indicate that MR angiography is useful in the
evaluation of residual patency of cerebral aneurysms treated with GDCs and may
eventually prove valuable in the follow-up of those cases in which a good initial
correlation with DSA was demonstrated.
PMID- 10782790
TI - Endovascular treatment of a ruptured paraclinoid aneurysm of the carotid syphon
achieved using endovascular stent and endosaccular coil placement.
AB - We herein report a case of a ruptured superior hypophyseal aneurysm of the left
supraclinoid carotid artery that could not be treated with a Guglielmi detachable
coil (GDC), even in combination with a supporting nondetachable balloon. After an
unsuccessful attempt at surgical clipping, treatment consisted of the placement
of a stent over the neck of the aneurysm, advancement of a microcatheter through
the stent mesh, and endosaccular embolization with a GDC. The late clinical
outcome was excellent.
PMID- 10782791
TI - Dense packing of cerebral aneurysms: an in vitro study with detachable platinum
coils.
AB - Aneurysm models were used to study the density of packing after coil
embolization. Platinum coils were introduced until the point of minimally dense
packing, indicated by aneurysmal circulatory exclusion. Packing was continued up
to the point of maximal density, indicated by protrusion into the parent artery.
Volumetric ratios (coil volume/aneurysmal volume) were calculated for minimally
and maximally dense packing. Maximally dense packing ratios were a little higher
than the minimally dense ratios, but less than 37%.
PMID- 10782792
TI - Transvenous embolization of a dural arteriovenous fistula of the anterior cranial
fossa: preliminary results.
AB - We report two cases of a dural arteriovenous fistula of the anterior cranial
fossa, one causing subarachnoid hemorrhage and one detected accidentally. The
first case was incompletely treated by neurosurgery, and the second one was
referred for endovascular therapy. Both fistulas were successfully occluded by
transvenous embolization by using electrolytically detachable coils.
PMID- 10782793
TI - MR imaging of patients with carotidynia.
AB - BACKGROUND AND PURPOSE: Carotidynia is an idiopathic neck pain syndrome
associated with tenderness to palpation over the carotid bifurcation. Although
well known in the otolaryngology and neurology literature, the validity of the
entity has recently been questioned, in part because of the almost uniform
absence of radiologic or pathologic findings. We report the MR findings in five
patients with carotidynia. METHODS: During a period of 44 months, five patients
with clinical signs and symptoms consistent with carotidynia were referred for
imaging from the otolaryngology service. Each patient underwent MR imaging of the
neck on a 1.5-T system. The studies included, as a minimum, pre- and postcontrast
axial and postcontrast coronal T1-weighted images. Two patients also had axial T2
weighted imaging and another two patients underwent duplex sonography of the
carotids. RESULTS: All five patients had abnormal enhancing tissue surrounding
the symptomatic carotid artery centered at the level of the distal common carotid
and carotid bifurcation. This tissue had intermediate signal intensity on T1
weighted images and showed marked enhancement. In all patients, the remaining
visualized portions of the carotid artery were normal. Normal flow voids were
present throughout the vessel, and the caliber of the vessels was always within
normal limits. There was no evidence of intramural hematoma, cervical
lymphadenopathy, or atherosclerotic disease of the vessel. In one patient, repeat
imaging after resolution of symptoms showed an absence of the previous
abnormality. CONCLUSION: The MR findings in these patients, along with the lack
of any findings to suggest alternative diagnoses, support the existence of
carotidynia as a distinct clinical entity.
PMID- 10782794
TI - The CT and MR imaging features of carcinoma arising in thyroglossal duct
remnants.
AB - BACKGROUND AND PURPOSE: Carcinoma arising in thyroglossal duct remnants is a well
described entity in the pathology and surgery literature, but it has little
recognition in the radiology literature. Preoperative diagnosis may alter
surgical management, although this diagnosis is rarely made. This study was
undertaken to determine the radiologic features that might differentiate
carcinoma from benign thyroglossal duct cysts. METHODS: Twenty-one cases of
nonpediatric thyroglossal duct anomalies imaged at our institution during a 15
year period were reviewed retrospectively. The images were assessed for lesion
wall thickness, enhancement, soft-tissue component, calcification, and loculation
of the cystic component. Three additional cases of thyroglossal duct carcinoma
obtained from outside institutions were reviewed for these features also.
RESULTS: Six cases of thyroglossal duct carcinoma were reviewed. All cases of
carcinoma had solid soft-tissue elements visible on CT scans or MR images,
compared with three of 18 cases of benign thyroglossal duct cysts. The malignant
component was seen as a small peripherally based mass in relation to a cyst, a
solid mass in the expected course of the thyroglossal duct, or a complex invasive
mass also in the midline of the neck. CT only revealed calcification in cases of
carcinoma, within either the primary carcinoma mass or a metastatic node.
CONCLUSION: Thyroglossal duct carcinoma should be suspected in an adult patient
in the presence of a solid nodule or invasive features in association with a
thyroglossal duct lesion visible on CT scans or MR images. The presence of
calcification, which is seen best on CT scans, may be a specific marker for
carcinoma.
PMID- 10782795
TI - Imaging of nonlaryngeal neuroendocrine carcinoma.
AB - The imaging and pathologic features of three cases of nonlaryngeal neuroendocrine
carcinoma of the head and neck are described. Neuroendocrine carcinomas represent
malignant epithelial neuroendocrine neoplasms and are classified as three types:
typical carcinoid (well differentiated), atypical carcinoid (moderately
differentiated), and small cell neuroendocrine (poorly differentiated)
carcinomas. The CT and MR imaging features of these tumors are nonspecific.
Paranasal sinus neuroendocrine carcinomas showed expansion and destruction of the
sinus, whereas metastatic neuroendocrine carcinomas to an intraparotid lymph node
presented as a circumscribed parotid mass on CT scans.
PMID- 10782797
TI - Peripheral spinal cord hypointensity on T2-weighted MR images: a reliable imaging
sign of venous hypertensive myelopathy.
AB - BACKGROUND AND PURPOSE: MR findings reported in conjunction with spinal dural
arteriovenous fistula (SDAVF) include cord swelling, increased T2 signal within
the spinal cord, and parenchymal enhancement, each of which is nonspecific.
Enlarged vessels on the cord surface, the most specific MR finding, is noted in
only half of SDAVF patients. Nevertheless, we have frequently observed MR
peripheral hypointensity of the spinal cord in SDAVF on T2-weighted images, which
is not characteristic of nonvascular or nonhemorrhagic causes of myelopathy and
which has not been described in association with SDAVF. We hypothesized that
peripheral cord hypointensity might reliably suggest the diagnosis of SDAVF or
other causes of venous hypertensive myelopathy. METHODS: We reviewed the MR
findings in 11 consecutive cases of angiographically confirmed symptomatic SDAVF
and in four cases of intracranial dural arteriovenous fistula with spinal
drainage, a lesion that also causes spinal cord deficits mediated by venous
hypertensive myelopathy. RESULTS: In each case, T2 hypointensity involving the
cord periphery was present. This sign has not been previously described in
association with either SDAVF or other causes of venous hypertensive myelopathy.
It appears, however, to be a relatively constant imaging feature of SDAVF.
CONCLUSION: In the absence of spinal hemorrhage, T2 hypointensity involving the
periphery of the spinal cord suggests venous hypertensive myelopathy as a cause
of spinal cord dysfunction.
PMID- 10782796
TI - CT-revealed choroidal effusions as a sign of carotid cavernous fistula.
AB - Choroidal effusions may appear as subtle abnormalities on CT scans. Recognition
of choroidal effusions, however, is critical because they may be an early sign of
ocular pathologic abnormality. After detection, the various causes of choroidal
effusions, such as carotid cavernous fistulas, ocular hypotony, tumors, and
inflammatory conditions, should be considered.
PMID- 10782798
TI - Giant cervical epidural veins after lumbar puncture in a case of intracranial
hypotension.
AB - A 29-year-old woman presented with dilated epidural veins and incapacitating
headache after undergoing a lumbar puncture. Two months later, the results of
follow-up MR imaging were normal. These findings suggest that temporary dilation
of the epidural vein may occur in association with post-lumbar puncture
intracranial hypotension syndrome. In these cases, it seems useful to confirm
whether the patient has recently undergone a lumbar puncture.
PMID- 10782799
TI - Intracranial calcifications in childhood medulloblastoma: relation to nevoid
basal cell carcinoma syndrome.
AB - BACKGROUND AND PURPOSE: Medulloblastoma is one of the most common posterior fossa
tumors to occur in children. Our purpose was to document the frequency, location,
and time of occurrence of intracranial calcifications in cranial CT studies of
children with medulloblastoma. METHODS: We retrospectively reviewed cranial CT
studies of 56 patients diagnosed with medulloblastoma from 1983 through 1997 for
the presence of intracranial calcifications. The findings were compared with 159
cranial CT studies of patients who were evaluated in the emergency department
(control group). Thirty-two patients with medulloblastoma without shunts were
compared with 118 patients from the control group without shunts. Similarly, 24
patients with medulloblastoma with shunts were compared with 41 patients from the
control group with shunts. RESULTS: Overall, three (9%) patients with
medulloblastoma without shunts, four (16%) patients with medulloblastoma with
shunts, and four (10%) patients from the control group with shunts had falx
calcification. Only the two children carrying the diagnoses of medulloblastoma
and nevoid basal cell carcinoma syndrome, however, had calcification of the falx
cerebri shown on the cranial CT scans obtained during the peridiagnostic period.
Both were diagnosed with medulloblastoma before the age of 3 years and later
developed jaw cysts and multiple basal cell carcinomas in the radiation field.
CONCLUSION: Previous studies have shown that falx calcification is a major
component of nevoid basal cell carcinoma syndrome. Our two cases illustrate the
importance of considering the diagnosis of nevoid basal cell carcinoma syndrome
when falx calcification is present in young patients with medulloblastoma. If the
concomitant diagnosis of nevoid basal cell carcinoma syndrome is made,
alternative types of therapy should be sought to minimize radiation therapy
sequelae.
PMID- 10782800
TI - Acute identification of cranial burst fracture: comparison between CT and MR
imaging findings.
AB - BACKGROUND AND PURPOSE: Scalp swelling associated with cranial burst fracture, a
widely diastatic skull fracture of infants associated with dural laceration and
acute cerebral extrusion, may be confused with that of a simple subgaleal
hematoma. Both conditions can also be associated with hemorrhagic shock. We
sought to improve the early evaluation of infants believed to have sustained
cranial burst fracture by including MR imaging, since this study clearly
delineates the dural-cortical interface, the site of injury. METHODS: Seven
infants aged 1 through 11 months who sustained cranial burst fractures, all
initially imaged with skull radiography and CT, were studied or treated from 1992
through 1996. MR imaging was obtained after resuscitation and stabilization.
RESULTS: Surgery or autopsy confirmed MR findings (dural laceration and
extracalvarial cerebral tissue) in all seven infants. CONCLUSION: MR imaging
allows early diagnosis of skull fracture associated with acute cerebral
extrusion.
PMID- 10782801
TI - A proposal for developing a large patient population cohort for longterm safety
monitoring in rheumatoid arthritis.
PMID- 10782802
TI - Longterm safety monitoring in rheumatoid arthritis. A proposal from OMERACT.
PMID- 10782803
TI - Is the progression of osteoarthritis phasic? Evidence and implications.
PMID- 10782804
TI - The case for classification of polymyalgia rheumatica and remitting seronegative
symmetrical synovitis with pitting edema as primarily capsular/entheseal based
pathologies.
PMID- 10782805
TI - Chimeric anti-tumor necrosis factor-alpha monoclonal antibody treatment of
patients with rheumatoid arthritis receiving methotrexate therapy.
AB - OBJECTIVE: To evaluate the safety and efficacy of single and multiple doses of a
chimeric anti-TNF-alpha monoclonal antibody (infliximab) in patients with
rheumatoid arthritis (RA) who had active disease despite therapy with
methotrexate (MTX). METHODS: Twenty-eight patients with active RA despite
receiving therapy with 10 mg/week of MTX were randomized to receive a single,
blinded infusion of either placebo or 5, 10, or 20 mg/kg infliximab. Twenty-three
patients who completed the blinded study entered an open, multiple dose extension
study in which they received up to 3 additional infusions of 10 mg/kg infliximab
at Weeks 12, 20, and 28. Safety, efficacy, and pharmacokinetics were evaluated
during the blinded and open trial. RESULTS: There were no serious infusion
related reactions. In the blinded phase, 17 (81.0%) of 21 patients receiving
infliximab achieved an American College of Rheumatology (ACR) 20% response at
some point during the 12 weeks of followup compared to one (14.3%) of 7 patients
receiving placebo (p = 0.003). Clinical improvement was evident by the first week
and was sustained through Week 12. For the 19 patients who received infliximab
during the blinded part of the trial and continued into the open label trial, 53%
maintained an ACR 20% response with multiple infusions of 10 mg/kg infliximab
through Week 40. Three patients withdrew from the trial during the open
continuation phase because of adverse events: cellulitis, infusion related
dizziness and headache, and vasculitic rash. Infliximab in doses of 5 to 20 mg/kg
had a mean terminal half-life ranging from 9 to 12 days and was detectable in
sera from most patients 8 to 12 weeks after dosing. CONCLUSION: Infliximab is
generally well tolerated during 40 weeks of therapy. A single infusion of 5 to 20
mg/kg infliximab significantly decreases the signs and symptoms of RA compared to
placebo in patients with active disease receiving MTX. Multiple doses of
infliximab produce sustained clinical benefit for up to 40 weeks.
PMID- 10782806
TI - Bucillamine suppresses human Th1 cell development by a hydrogen peroxide
independent mechanism.
AB - OBJECTIVE: To clarify the effect of bucillamine, an antirheumatic drug related to
D-penicillamine, on the development of human Th1 and Th2 cells in vitro. METHODS:
Peripheral blood mononuclear cells (PBMC) or purified CD4+ T cells were subjected
to the priming culture in which cells were stimulated with anti-CD3 and anti-CD28
monoclonal antibodies for 3 days and expanded for 4 days in the presence of
interleukin-2. Cytokine production by the generated cells was determined on a
flow cytometer using intracellular cytokine staining. The effects of bucillamine
were determined by adding it for the first 3 days of the priming culture.
RESULTS: Bucillamine decreased the frequency of interferon-gamma (IFN-gamma)
producing CD4+ T cells among generated CD4+ T cells after the priming culture of
PBMC, although D-penicillamine did not. This effect of bucillamine was
independent of hydrogen peroxide since it was not reversed by a catalase
treatment. One of the bucillamine metabolites, SA981, which exerts its effects by
a hydrogen peroxide-independent mechanism, decreased the frequency of IFN-gamma
producing CD4+ T cells more potently than bucillamine. Bucillamine reduced the
frequency of Th1 cells after the priming culture of purified CD4+CD45RO- T cells,
indicating that bucillamine exerts the effect in the absence of monocytes or B
cells. CONCLUSION: Bucillamine directly acts on CD4+CD45RO- T cells to suppress
Th1 cell development by a hydrogen peroxide-independent mechanism. This
previously unknown action may explain the in vivo effect of bucillamine in the
treatment of rheumatoid arthritis.
PMID- 10782807
TI - Cathepsin B and its endogenous inhibitor cystatin C in rheumatoid arthritis
synovium.
AB - OBJECTIVE: To compare the expression of cathepsin B and its endogenous inhibitor
cystatin C in synovial tissue of patients with rheumatoid arthritis (RA) and to
determine the cell type expressing cystatin C. METHODS: The expression of
cathepsin B and cystatin C was studied by immunohistochemistry in synovial tissue
of 10 patients with RA and compared to healthy controls. Applying double labeling
methods, the expression of cathepsin B was compared to that of cystatin C. To
determine the cell type expressing cystatin C, double labeling with anti-CD68 (PG
M1) was performed. RESULTS: Both cystatin C and cathepsin B were strongly
expressed in synoviocytes of patients with RA. Furthermore, fibroproliferative
tissue at the site of cartilage and bone destruction contained fibroblast-like
and macrophage-like cells positive for cystatin C and cathepsin B, whereas normal
synovial tissue exhibited only limited expression of these molecules. Osteoclasts
revealed positive staining for CD68 and cystatin C, but not for cathepsin B.
CONCLUSION: Cystatin C is a product of both macrophage-like and fibroblast-like
synoviocytes. The strong expression of both the matrix degrading cysteine
proteinase cathepsin B and the cysteine proteinase inhibitor cystatin C in
rheumatoid synovium, particularly at the sites of bone and cartilage erosion,
suggests that cystatin C--although increased--is not sufficient to prevent matrix
degradation by cathepsin B.
PMID- 10782808
TI - Epstein-Barr virus infection in peripheral blood mononuclear cells, synovial
fluid cells, and synovial membranes of patients with rheumatoid arthritis.
AB - OBJECTIVE: Different infectious agents have been proposed to be involved in the
pathogenesis of rheumatoid arthritis (RA). We investigated the role of latent
Epstein-Barr virus (EBV) infection in patients with RA. METHODS: Sera of 55
patients with RA and 60 age and sex matched healthy controls were examined for
antibodies against EBV encoded antigens (EBNA-1, VCA, and EA) by ELISA. The
presence of viral DNA was analyzed by polymerase chain amplification of DNA
isolated from peripheral blood mononuclear cells (PBMC) of these samples and from
cells of synovial fluid (SF) specimens. Paraffin sections of synovial membranes
from 25 patients were subjected to in situ hybridization analysis for the EBV
encoded small RNA EBER1 and EBER2. RESULTS: Two-fold increased values of IgG
antibodies against EBNA-1 were found in patients with RA in comparison to healthy
controls (p = 0.029). No statistically significant difference could be observed
for antibody levels against EBV-VCA. Fourteen (24.1%) of 55 patients with RA had
serological evidence of reactivated EBV infection in comparison to none of the
control group (p = 0.028). In PBMC, EBV DNA was detected in a significantly
higher proportion in the patient group (50.9 vs. 30%; p = 0.02). In addition, SF
cells harbored the viral DNA in 30% of RA cases compared to 16.6% of control
cases (p = 0.02). However, EBER1/2 transcripts could only be found within
synovial membranes of 2 (8%) of 25 patients with RA. CONCLUSION: These findings
support the hypothesis that EBV infection may be involved in the pathogenesis of
RA. Further studies may define the precise pathogenetic mechanisms of viral
infection for the development of inflammatory arthritis.
PMID- 10782809
TI - Synovial hyperplasia in HTLV-I associated arthropathy is induced by tumor
necrosis factor-alpha produced by HTLV-I infected CD68+ cells.
AB - OBJECTIVE: To investigate the pathogenic role of macrophage lineage (CD68+) cells
in synovial proliferation in patients with human T cell leukemia virus I (HTLV-I)
associated arthropathy (HAAP). METHODS: Synovial tissues obtained from 3 patients
with HAAP and 3 patients with osteoarthritis (OA) were examined for the
expression of tumor necrosis factor-alpha (TNF-alpha) mRNA, HTLV-I tax/rex mRNA,
and number of CD68 by in situ reverse transcription assay and
immunohistochemistry. Western blot and flow cytometric analyses were used to
determine TNF-alpha production in HTLV-I infected synoviocytes. Changes in CD68+
cell population were examined by flow cytometric analysis. Proliferative effects
of supernatants of HTLV-I infected synoviocytes on normal synoviocytes were also
determined. RESULTS: TNF-alpha and HTLV-I tax/rex mRNA were preferentially
expressed in CD68+ cells in HAAP synovia. Infection of OA synoviocytes by HTLV-I
resulted in preferential expression in CD68+ cells, and these cells produced TNF
alpha. Supernatants of HTLV-I infected synoviocytes significantly enhanced the
proliferation of normal synoviocytes through a TNF-alpha dependent pathway.
CONCLUSION: Our results suggest HTLV-I viral tropism for CD68+ cells, and that
HTLV-I infected synoviocytes were induced to produce TNF-alpha, which enhances
synovial proliferation in HAAP.
PMID- 10782810
TI - High serum levels of pro-matrix metalloproteinase-3 are associated with greater
radiographic damage and the presence of the shared epitope in patients with
rheumatoid arthritis.
AB - OBJECTIVE: To determine if there is a relationship between serum pro-matrix
metalloproteinase-3 (proMMP-3) levels and radiographic damage in rheumatoid
arthritis (RA), and to investigate whether high levels are associated with
presence of the HLA-DRB1 shared epitope (SE). METHODS: Serum proMMP-3 levels were
measured by ELISA on 45 RA patients with early disease and 292 with established
disease. Early RA was arbitrarily defined as disease duration <3 years. Clinical
and laboratory measures of disease activity and severity were obtained.
Radiographic damage was assessed by scoring radiographs of the hands and feet
using the method of Larsen. HLA-DRB1 typing was performed by sequence-specific
oligonucleotide probing. Data were analyzed by multiple regression analysis.
RESULTS: In all patients, there was a correlation (r = 0.318, p<0.0001) between
serum proMMP-3 levels and Larsen scores. Other correlations were found with
Health Assessment Questionnaire score (r = 0.261, p<0.0001) and C-reactive
protein (CRP) (r = 0.357, p<0.0001) levels. ProMMP-3 levels were significantly
higher in SE+/+ patients than in those completely lacking the SE, with the
highest levels in patients carrying an HLA-DRI+/DR4+ phenotype. The greatest
difference in proMMP-3 levels between SE+/+ and SE-/- patients was in those with
a disease duration <3 years (381.6 vs. 71.7 ng/ml; p = 0.02). CONCLUSION: Our
data indicate that there is a significant relationship between radiographic
damage and serum levels of proMMP-3. As well, higher circulating levels of proMMP
3 are found in patients positive for the SE, particularly in early RA, and this
may partly explain the association between the SE and more erosive disease.
PMID- 10782811
TI - Matrix metalloproteinase-3 serum levels are correlated with disease activity and
predict clinical response in rheumatoid arthritis.
AB - OBJECTIVE: To demonstrate that serum matrix metalloproteinase-3 (MMP-3) is a
variable associated with disease activity and with the response to treatment in
rheumatoid arthritis (RA). METHODS: Serum MMP-3 levels were measured and compared
to biological and clinical disease activity variables in 20 patients with active
RA assessed serially during a one year prospective open label trial with
methotrexate or tenidap. RESULTS: MMP-3 levels were significantly correlated with
C-reactive protein (CRP) and interleukin 6 serum levels as well as with the
disease activity score (DAS), not only at start in untreated patients but also
during the 12 month followup period in both treated groups. Early changes (after
0.5, 1, 2, or 3 months) in MMP-3 levels were significantly associated with change
in DAS observed 4 to 6 months later. CONCLUSION: In addition to CRP, a systemic
marker of inflammation, serum MMP-3 may serve as a consistent synovial derived
marker of RA disease activity, early changes of which predict disease outcome.
PMID- 10782812
TI - High macrophage-colony stimulating factor levels in synovial fluid of loose
artificial hip joints.
AB - OBJECTIVE: To clarify a macrophage-colony stimulating factor (M-CSF) related
mechanism of aseptic loosening of artificial hip joints. METHODS: Synovium-like
interface tissues between bone and prosthesis, regenerated pseudocapsular
tissues, and synovial fluid (SF) were collected from 9 patients with loose
artificial hip joint at revision surgery. Tissue distribution, production site,
and SF level of M-CSF in loose hip joints were investigated by
immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR),
and ELISA, respectively. For a comparative assessment of the M-CSF level in loose
hip joints, SF of active rheumatoid arthritis (RA) and mild osteoarthritis (OA)
also were analyzed by ELISA. RESULTS: Immunohistochemical analysis showed the
presence of M-CSF immunoreactive cells mainly in the interface tissues between
bone and prosthesis and inner pseudocapsular tissues, both of which were in
contact with joint fluid. RT-PCR analysis confirmed the local production of M-CSF
in these periprosthetic tissues. Significantly higher M-CSF level in loose hip
joint fluid than in active RA and mild OA fluid was revealed by ELISA.
CONCLUSION: High M-CSF level in loose hip joint fluid suggests transportation of
M-CSF from production sites to joint fluid. This indicates that not only
polyethylene wear particles (reported to induce foreign body reaction at the bone
prosthesis interface), but also M-CSF, abundant in joint fluid, are transported
to and affect the interface. Thus, M-CSF is locally produced in periprosthetic
tissues of loose hip joints and possibly contributes to periprosthetic weakening
and osteolysis via joint fluid, leading to prosthetic loosening.
PMID- 10782813
TI - Lupus nephritis outcomes: health maintenance organizations compared to non-health
maintenance organizations.
AB - OBJECTIVE: Patients with systemic lupus erythematosus (SLE) in USA increasingly
have their care centered in health maintenance organizations (HMO). We examined
whether HMO and non-HMO SLE patients with renal involvement, who had the same
university rheumatologist, differed in their utilization of health care or renal
outcomes. METHODS: Consecutive patients with SLE with renal involvement (n = 24),
10 enrolled in an HMO, 14 not, were studied. Laboratory values were prospectively
determined. RESULTS: At the first visit to the rheumatologist, there was no
significant difference between HMO and non-HMO patients in laboratory values.
There was no difference in the 2 groups in the final prednisone dose (HMO 12 mg
vs non-HMO 15.9 mg) or use of azathioprine (20% vs. 57%; p = 0.07) or
cyclophosphamide (60% vs. 57%). The serum creatinine was higher in the HMO
patients (HMO 1.1 mg/dl vs. non-HMO 0.78 mg/dl; p = 0.05). No difference was
found in the number of rheumatology visits. There was a significant difference in
the number of communications from the rheumatologist to the HMO versus the HMO to
the rheumatologist (p = 0.026). CONCLUSION: Other than the serum creatinine,
there are no differences in the treatment or renal outcomes for HMO compared to
non-HMO patients with SLE seeing the same rheumatologist. There is a potential
barrier in physician communication, however, with the majority of communications
going from the rheumatologist to the HMO provider.
PMID- 10782814
TI - Altered function of the hypothalamic stress axes in patients with moderately
active systemic lupus erythematosus. I. The hypothalamus-autonomic nervous system
axis.
AB - OBJECTIVE: To determine the human corticotropin releasing hormone (hCRH) induced
stress response of the hypothalamus-autonomic nervous system axis (HANS) in
patients with moderately active systemic lupus erythematosus (SLE). METHODS:
Cardiovascular and pupillary function variables were measured by standardized
computer procedures before and during an hCRH test (6 time points). The results
of 12 patients with SLE were compared to 24 healthy subjects with (HS+P, n = 12)
and without (HS, n = 12) prior administration of prednisolone 3 days before the
test. RESULTS: At baseline, diastolic blood pressure was significantly higher in
SLE than in HS or HS+P (p<0.001). During the hCRH test, patients with SLE had
increased heart rates and systolic and diastolic blood pressure responses
compared to HS+P and HS (p<0.001 for all comparisons). Moreover, heart rate
variation was decreased at rest, during the lying-to-standing procedure, and
during the 2 applied respiratory tests (p<0.01 vs. HS). Compared to HS+P and HS,
latency time of the pupillary light reflex was prolonged and maximal pupillary
area was increased, revealing sympathetic hyperreactivity. CONCLUSION: This study
found an altered autonomic nervous system response at baseline, which was more
pronounced during the hCRH stress test in patients with moderately active SLE
compared to healthy subjects. Baseline and stress responses are characterized by
a sympathetic overstimulation. Such a hypersympathetic reaction may lead to
increased risk of cardiovascular diseases in patients with moderately active SLE,
which needs to be investigated in longitudinal studies.
PMID- 10782815
TI - Altered function of the hypothalamic stress axes in patients with moderately
active systemic lupus erythematosus. II. Dissociation between androstenedione,
cortisol, or dehydroepiandrosterone and interleukin 6 or tumor necrosis factor.
AB - OBJECTIVE: To investigate adrenocorticotropin, androstenedione (ASD), cortisol,
or dehydroepiandrosterone sulfate (DHEAS) before and during a corticotropin
releasing hormone (hCRH) test in patients with moderately active systemic lupus
erythematosus (SLE) undergoing low dose longterm glucocorticoid therapy, and to
examine these hormones in relation to interleukin 6 (IL-6) or tumor necrosis
factor (TNF). METHODS: Serum levels of hormones and cytokines were measured
before and during an hCRH test. The results of 12 patients with SLE were compared
to 12 healthy subjects (HS) and 12 healthy subjects given prior short term
prednisolone (HS+P). RESULTS: Baseline and stimulated serum ASD, cortisol, and
DHEAS were lower in patients with SLE vs. HS (p<0.005), but baseline and
stimulated plasma adrenocorticotropin was normal in SLE. In SLE, but not in HS+P
or HS, baseline and stimulated DHEAS was low in relation to cortisol or ASD
(i.e., shift from DHEAS to cortisol or ASD). In patients with SLE, baseline and
stimulated serum levels of adrenal hormones were lower in relation to IL-6 or TNF
compared to HS or HS+P (p< 0.001). In contrast, in SLE patients, the baseline and
stimulated pituitary hormone adrenocorticotropin was normal in relation to these
cytokines. CONCLUSION: We found marked adrenal insufficiency and a shift in
steroidogenesis to cortisol in patients with SLE, but a completely normal
pituitary function (in absolute values and in relation to IL-6 or TNF). This may
depend in part on prior longterm glucocorticoid therapy and changes of
steroidogenesis due to cytokines. The situation in patients with SLE was not
mimicked by high dose short term prednisolone in healthy subjects. Further
longitudinal studies in untreated patients are needed to investigate the
endocrine-immune interplay and its consequences during the course of SLE.
PMID- 10782816
TI - Outcome of total hip replacement for avascular necrosis in systemic lupus
erythematosus.
AB - OBJECTIVE: To describe the short and medium term results of total hip
arthroplasty (THA) for avascular necrosis in patients with systemic lupus
erythematosus (SLE). METHODS: Nineteen patients with SLE and avascular necrosis
of the femoral head (AVNFH), who underwent 26 THA were retrospectively reviewed
with a minimum followup of 2 years. To determine whether these patients had
results similar to those of patients with other conditions, we formed a control
group of 19 patients who had 29 THA. They were matched for age, sex, and followup
to the patients with SLE. Controls had THA for juvenile rheumatoid arthritis (n =
7), osteoarthritis (5), adult onset rheumatoid arthritis (8), developmental
dysplasia of the hip (4), and other diagnoses (5). Outcome measures included a 10
point visual analog scale (VAS) for pain, the Harris hip score, and the SF-36
self-administered health outcome questionnaire. We used the methods of Delee,
Harris, and Engh for radiological assessment. RESULTS: Mean age at surgery was 46
years (range 21-71 years) and average followup was 4 years, 7 months (range 1 yr
9 mo to 9 yrs 6 mo), similar in both groups. Technical problems, mostly
consisting of small, nonpropagating cracks of the calcar in uncemented stems,
were encountered in 4 SLE hips and 1 control hip. Six complications were noted in
the SLE group, including 2 early, nonrecurrent dislocations, 1 patient with thigh
pain for 1 year, 1 pericarditis, 1 sick-sinus syndrome, and 1 urinary tract
infection. There was one case of urinary tract infection in the control group.
One SLE patient developed a low grade prosthetic infection and underwent
successful revision 2 years after primary surgery. Clinical outcome measures had
similar scores in the 2 groups: average VAS pain score = 2.00 in SLE hips
(maximum 10) and 1.97 in control hips; mean Harris hip score = 86.7 in SLE
patients (maximum 100) and 81.9 in controls; average SF-36 score = 63.4 in SLE
patients (maximum 100) and 60.5 in controls. There was no radiological evidence
of implant loosening in controls; there was 1 asymptomatic cup migration in the
SLE group. CONCLUSION: In the short and medium term, patients with SLE and AVN
had good results after THA. Results were similar in patients who had hip
replacement for other diagnoses. Less favorable clinical outcomes of hip
replacement have been reported in young patients who have AVN of other etiology
(e.g., alcoholic, post-traumatic), but this was not the case in our young
patients who had AVN and SLE. Thus, AVNFH and SLE should not constitute a
contraindication to hip replacement.
PMID- 10782817
TI - Antiprothrombin and antiannexin V antibodies imply risk of thrombosis in patients
with systemic autoimmune diseases.
AB - OBJECTIVE: To investigate the relationship between antiprothrombin (aPT) and
antiannexin V (aANX) autoantibodies of IgG isotype and thrombosis in patients
with systemic autoimmune diseases. To compare the clinical relevance of these
antibodies to that of anticardiolipin (aCL), anti-beta2-glycoprotein I antibodies
(anti-beta2-GPI), and lupus anticoagulant (LAC). METHODS: Serum IgG aPT, aANX,
aCL, and anti-beta2-GPI levels were measured by solid phase enzyme immunoassay in
the sera of 70 patients with systemic autoimmune diseases, 35 with
antiphospholipid syndrome (APS) and 35 without APS. Medical records were
analyzed, and associations of the antibodies with clinical features of APS were
assessed. RESULTS: Patients with APS had higher frequency of aPT (p = 0.001) and
aANX (p = 0.002) compared to patients without APS. Thrombotic events occurred
more frequently in those with aPT or aANX than those without (p = 0.005, p =
0.006, respectively). The presence of aPT and aANX was found to be highly
specific for APS. CONCLUSION: Measurement of aPT and aANX antibodies may be of
value in confirming the diagnosis of APS, and in evaluating risk of venous and
arterial thrombosis in patients with systemic autoimmune diseases.
PMID- 10782819
TI - Increased serum levels of interleukin 10 in Sjogren's syndrome; correlation with
increased IgG1.
AB - OBJECTIVE: To determine levels of interleukin 10 (IL-10) and IgG subclasses in
serum from 53 patients with primary Sjogren's syndrome (SS). METHODS: Serum
levels of IL-10 were measured using specific sandwich ELISA in 25 patients with
"definite" SS, 28 with "possible" SS, and 32 healthy controls. Interferon-gamma
(IFN-gamma) and transforming growth factor-beta1 (TGF-beta1) were also measured
by immunoassays. Immunoglobulin classes, IgG subclasses, and C-reactive protein
were measured by nephelometry. RESULTS: Circulating IL-10 was elevated in 25
patients. The increase reached significance in the group with possible SS (p =
0.03) versus controls. In the group with definite SS, IL-10 level was correlated
with IgG1 level (p = 0.01, r = 0.67) and with focus score (p = 0.01). IFN-gamma
was undetectable in most patients. TGF-beta1 was higher (not significantly) in
possible SS than in definite SS. CONCLUSION: IL-10 is increased in SS and may
account for the overproduction of IgG1 in the syndrome. High IL-10 in the absence
of increased IgG1 in possible SS suggests that IL-10 may be necessary but not
sufficient for IgG1 overproduction and that other factors are involved. Whereas
the correlation of IL-10 level with focus score was expected, it is intriguing
that IL-10 was more frequently increased in the incomplete (possible) form of SS
than the complete (definite) form. Elevated IL-10 may characterize the lower
stage of eccrine dysfunction and perhaps contributes to limiting its severity.
PMID- 10782818
TI - Serum levels of KL-6 as a useful marker for evaluating pulmonary fibrosis in
patients with systemic sclerosis.
AB - OBJECTIVE: KL-6 is a mucin-like glycoprotein that is strongly expressed on type
II pneumocytes in the lung. Circulating KL-6 has been shown to be a sensitive
marker of the disease activity of interstitial lung diseases. We determined the
serum levels of KL-6 in patients with systemic sclerosis (SSc) and investigated
whether these levels would serve as a useful marker of pulmonary fibrosis (PF) in
patients with SSc. METHODS: The serum KL-6 levels were determined using a
specific ELISA in 91 patients with SSc, and in 38 healthy controls. RESULTS: The
serum levels of KL-6 were significantly higher in patients with SSc than in
healthy controls (923+/-860 vs. 382+/-55 U/ml; p<0.0001). The serum KL-6 levels
of the patients with diffuse cutaneous SSc (dSSc) tended to be higher than those
with limited cutaneous SSc (ISSc) (1054+/-1000 vs. 800+/-694 U/ml), but there was
no significant difference between these 2 groups. The serum KL-6 levels in the
patients with PF were significantly elevated compared to those without PF (1283+/
1056 vs. 520+/-148 U/ml; p<0.0001). Moreover, DLCO and VC were also significantly
decreased in the patients with elevated KL-6 levels compared to those with normal
levels (62+/-22% vs. 72+/-17%, p<0.05; 87 +/-20% vs. 100+/-18%, p<0.01,
respectively). CONCLUSION: Serum KL-6 level may be a useful serum marker for
evaluating pulmonary fibrosis in patients with SSc.
PMID- 10782820
TI - Increased expression of interleukin 1alpha and MHC class I in muscle tissue of
patients with chronic, inactive polymyositis and dermatomyositis.
AB - OBJECTIVE: To investigate if there is a molecular correlate in muscle tissue to
the persisting decreased muscle function in patients with chronic, inactive
polymyositis (PM) and dermatomyositis (DM). METHODS: Muscle function was assessed
using a muscle function index of myositis. To assess disease activity both
histopathological investigation of muscle biopsies and magnetic resonance imaging
(MRI) scans of the thigh muscles were performed. Inactive chronic disease was
defined as persisting muscle weakness and absence of inflammatory infiltrates in
muscle biopsy and absence of signs of inflammation on MRI. Expression of
interleukin 1alpha (IL-1alpha), IL-1beta,, adhesion molecules, and MHC class I
molecules in muscle tissue was investigated with immunohistochemistry. RESULTS:
Muscle weakness was confirmed by a reduction of muscle function score. No signs
of inflammation typical for myositis were observed. The most striking finding in
our study was the strong expression of IL-1alpha and MHC class I molecules in
muscle tissue from patients with inactive chronic PM and DM. Increased IL-1alpha
expression was evident in capillaries and increased MHC class I expression was
detected in muscle fiber membranes. CONCLUSION: IL-1alpha and MHC class I
molecules may have an importance in the pathogenesis of the chronic muscle
weakness and fatigue in patients with PM and DM.
PMID- 10782822
TI - Lack of association between infection and onset of polymyalgia rheumatica.
AB - OBJECTIVE: The etiology of giant cell arteritis (GCA) is unknown, but its sudden
onset and the wide variation in incidence reported from various parts of the
world suggest a genetic predisposition and/or the influence of environmental
factors, such as infectious agents or a seasonal effect. We analyzed the
influence of season on GCA in our area over the period 1985-97, as well as the
possible association between infection and onset. METHODS: Retrospective study of
143 cases of GCA diagnosed from 1985 to 1997. To evaluate seasonal variation in
disease onset, the month of onset of the first symptoms related to GCA was used
to calculate season-specific incidence rates. Differences between season
incidence rates were assessed by chi-square test. To test for an association
between infection and GCA onset, we considered only infections that occurred
within 2 months before the onset of disease. Because of the difficulty in
determining whether an infection was present using only the clinical and
laboratory data recorded in patients' medical charts, we categorized the
likelihood of patients having infection into 3 groups: no infection, probable
infection, and definite infection. RESULTS: Between 1985 and 1997 (both years
included), a total of 143 patients (88 women, 55 men) were diagnosed with GCA. Of
these, 85 had isolated polymyalgia rheumatica (PMR), 22 had temporal arteritis
(TA) without PMR, and 36 had PMR associated with TA. The main clinical features
in our population were similar to those reported in other studies. We found no
seasonal variation in disease onset during the 13 year period. Moreover, only one
(0.7%) of 143 patients was categorized as a probable infection, whereas definite
infection was not observed in any case. From these results, the hypothesis of an
infectious cause for GCA seems highly improbable. CONCLUSION: We were unable to
observe a seasonal pattern or an association between infection and the onset of
GCA.
PMID- 10782821
TI - Amyloid myopathy masquerading as polymyositis.
AB - OBJECTIVE: It is not well appreciated that the clinical presentation of amyloid
myopathy can mimic that of polymyositis. By retrospective clinicopathologic
analysis we determined distinctive features of amyloid myopathy that
differentiate the 2 diseases. METHODS: Two patients with clinical and histologic
evidence of an inflammatory myopathy had fatal outcomes despite appropriate
treatment for polymyositis. Their clinical course and original pathologic
specimens were reviewed. In addition, original tissue samples were obtained and
analyzed using Congo red staining and immunoperoxidase. RESULTS: The initial
diagnosis of polymyositis was supported in both cases by muscle biopsies showing
inflammatory infiltrates and elevations of creatine phosphokinase and by classic
electromyography. Retrospective evaluation of the initial muscle biopsies
disclosed subtle but incontrovertible evidence of vascular amyloid. Further
analysis of the original specimens confirmed the presence of immunoglobin light
chain (AL) amyloid. CONCLUSION: Amyloid myopathy can mimic polymyositis. Both can
have similar clinical symptoms, as well as inflammatory infiltrates on muscle
biopsy. Failure to recognize amyloid myopathy deprives patients of potentially
life prolonging treatment. Congo red staining and immunohistochemical analysis of
tissue could prevent misdiagnosis.
PMID- 10782823
TI - The relationship between patient satisfaction with health and clinical measures
of function and disease status in patients with psoriatic arthritis.
AB - OBJECTIVE: To investigate whether patient satisfaction with health is a distinct
aspect of clinical or health status in a sample of patients with psoriatic
arthritis (PsA). METHODS: One hundred sixty-nine consecutive outpatients
attending the University of Toronto PsA Clinic completed the Arthritis Impact
Measurement Scales II (AIMS2), which includes both a global rating of patient
satisfaction with health and a scale that assesses satisfaction with functioning
in 12 health domains. Clinical, laboratory, and radiological assessments of
function, pain, inflammation, and damage were also performed according to a
standard protocol. RESULTS: Logistic regression analysis indicated that the AIMS2
global ratings of patient satisfaction with health were not associated with
traditional clinical measures of inflammation and damage, but were associated
with American College of Rheumatology (ACR) functional class and number of
fibromyalgia tender points. Patient satisfaction was also related to annual
family income and use of retinoids or corticosteroids. Similarly, linear
regression analysis showed that scores on the AIMS2 satisfaction scale were
unrelated to traditional clinical measures of inflammation and damage, with the
exception of total number of actively inflamed joints. ACR functional class,
annual family income, and comorbidity were also related to scores on the
satisfaction scale. CONCLUSION: Patient satisfaction with health appears to be
relatively independent of traditional clinical measures of physical functioning,
pain, and disease status.
PMID- 10782824
TI - Type and outcome of reconstructive surgery for different patterns of psoriatic
arthritis.
AB - OBJECTIVE: To describe our experience of musculoskeletal surgery in patients with
different patterns of psoriatic arthritis (PsA). METHODS: From 1986 to 1996, 71
operations in 43 patients with established PsA were performed at our institution.
The patterns of PsA recognized in this patient group were: distal PsA,
oligoarticular PsA, and polyarticular PsA, with or without associated
spondylitis. Surgical findings and procedure, intra- and postoperative
complications were recorded. Nineteen patients were available for clinical
evaluation, both by conventional surgeon generated and by patient generated self
administered questionnaires. RESULTS: The majority of patients had polyarticular
PsA. All operations in patients with distal PsA were distal interphalangeal (DIP)
and proximal interphalangeal (PIP) joint fusions. All operations in patients with
oligoarticular PsA involved the hip or knee. Polyarticular patients underwent a
range of procedures. Soft tissue contractures and bone loss required specific
attention in 14 procedures. In the 19 patients who were reviewed clinically,
conventional scoring of individual procedures showed good to excellent results.
Patient oriented outcomes had low scores compared to a disease-free general
population. CONCLUSION: The 3 principal patterns of PsA are associated with
different types of surgery. Although traditional surgeon generated scores
evaluating individual procedures indicated results comparable to patients who
have osteoarthritis, patient generated outcome measures of global health and
function scored substantially lower than a general, arthritis-free population,
reflecting the burden of polyarticular involvement.
PMID- 10782825
TI - Discovertebral erosions and destruction in psoriatic arthritis.
AB - OBJECTIVE: To evaluate the prevalence and clinical features of destructive
abnormalities of the discovertebral junction in psoriatic arthritis (PsA).
METHODS: One hundred consecutive patients with PsA (38 with spondylitis, 48 with
polyarthritis, 14 with oligoarthritis; 52 men and 48 women; mean age 45.74 years,
range 18-76, mean duration of disease 79.84 mo, range 8-336) were evaluated. The
study protocol included a questionnaire on the patient's usual work, occurrence
of previous trauma or infection to the spine, characteristics of articular
involvement, and presence and characteristics of back pain. Radiographic study of
involved joints and of the spine was performed and lesions occurring at the
discovertebral junction were classified according to Cawley's suggestions.
RESULTS: Twelve patients showed destructive abnormalities of the discovertebral
junction (12.0%). These patients had age and disease duration significantly
greater than the patients without abnormalities (p = 0.0001 and 0.0001,
respectively). Nine of them had spondylitis and 3 polyarthritis (p = 0.02).
Cervical tract was affected in 4 cases (33.3%) and thoracic in 12 (100%). Lumbar
spine changes occurred in 6 patients (50%). Lesions were localized to only one
level in 4 cases and at multiple levels in the remaining 8. According to Cawley's
classification type 1 lesions involved 6 thoracic discovertebral junctions, type
2 involved 15 junctions (4 cervical, 5 thoracic, 6 lumbar), type 3 only one
thoracic junction. Back pain occurred in only 5 cases (41.6%), all belonging to
the spondylitic subset. Pain was localized to those tracts of the spine with
radiographically documented disease and was exacerbated with physical activity.
CONCLUSION: Discovertebral erosions seem to be another characteristic aspect of
spondyloarthropathies. In PsA, the lesions occur markedly in older spondylitic
patients with a greater duration of disease and may often be totally
asymptomatic.
PMID- 10782826
TI - Gene delivery to human chondrocytes by an adeno associated virus vector.
AB - OBJECTIVE: To investigate the efficiency of gene transduction to human
chondrocytes using an adeno associated virus (AAV) vector. METHODS: We transduced
green fluorescent protein (GFP) gene using AAV vector to primary human
chondrocytes as well as human cartilage organ cultures, in which chondrocytes are
surrounded by extracellular matrix. Expression of GFP gene was analyzed at
various time points after transduction by fluorescence microscopy and
immunohistochemistry. RESULTS: In primary chondrocytes, the percentages of GFP
positive cells were 15.9% or 16.0% on Day 1 and 95.0% or 93.7% on Day 7 after
gene transduction. In cartilage organ cultures, gene delivery was observed in
cells located not only in the superficial layer but also in the deep layer within
the cartilage tissue. Up to 45.3+/-7.4% or 46.0+/-3.9% of chondrocytes expressed
GFP for at least 28 days. CONCLUSION: AAV vector could be useful for direct gene
delivery to chondrocytes in situ.
PMID- 10782827
TI - Empirical advantages of adeno associated viral vectors in vivo gene therapy for
arthritis.
AB - OBJECTIVE: To evaluate the utility of the adeno associated viral (AAV) vector for
gene delivery to joint cells in vivo and in vitro, and to assess its potential as
a vector for arthritis gene therapy. METHODS: A recombinant AAV (rAAV) vector
expressing the bacterial beta-galactosidase (beta-gal) gene (rAAV-CMV-LacZ) was
directly introduced into healthy-normal mouse knees, or arthritic knees in mice
overexpressing tumor necrosis factor-alpha (hTNFalpha-Tg). Beta-gal expression
levels were determined by immunohistochemistry and chemiluminescence. The
transduction efficiency of this vector on primary fibroblast-like synoviocytes
(FLS) in vitro was determined by FACS. The effects of UV and gamma-irradiation as
well as TNF-alpha on transduction efficiency were determined using the same
methods. RESULTS: We found little evidence of rAAV transduction in the joint
cells of healthy mice. Target gene expression was detected in all animals at Day
3, and peaked at Day 7 before returning to baseline levels 21 days after
injection. In contrast, synoviocytes, articular chondrocytes, and meniscal cells
of diseased mice were transduced by rAAV-CMV-LacZ in hTNFalpha-Tg animals.
Transduction efficiencies correlated with joint damage, and target gene
expression was up to 10-fold greater than that seen in the normal mice. In vitro,
we found that rAAV transduction of FLS can be enhanced by pretreatment with UV or
gamma-irradiation and TNF-alpha stimulation. CONCLUSION: We find that rAAV
vectors have several empirical advantages for in vivo gene therapy for arthritis:
(1) rAAV preferentially transduces arthritic joint cells in vivo. (2) rAAV can
transduce both FLS and chondrocytes in vivo. (3) rAAV transduction of FLS can be
augmented by pretreatment with agents that induce DNA repair enzymes.
PMID- 10782828
TI - Ex vivo gene delivery using an adenovirus vector in treatment for cartilage
defects.
AB - OBJECTIVE: To realize local selective gene expression in grafted chondrocytes for
cartilage defect, we investigated the usefulness of an ex vivo gene delivery
method using an adenovirus vector. METHODS: Beta-galactosidase gene (LacZ) was
transfected using an adenovirus vector to chondrocytes isolated from rat joints.
The cells were then embedded into collagen gel, and LacZ expression in the gel
was examined using 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-gal)
staining; beta-galactosidase activity was also measured. The collagen gel
containing transfected chondrocytes was grafted to the experimental cartilage
defects, and the expression of delivered gene was histologically examined after X
gal staining of the tissue containing the grafted area. RESULTS: X-gal positive
chondrocytes in the gel accounted for 82% at one week and 55% at 8 weeks after
gene delivery. Beta-galactosidase activity decreased with time, but its
expression was maintained even at 8 weeks after gene delivery. Chondrocytes used
in the allograft maintained their morphology, and the expression of delivered
gene continued during the 8 week period. CONCLUSION: In this ex vivo method,
delivered gene can be expressed efficiently for a long time; this method would be
useful in allografts for cartilage defects.
PMID- 10782829
TI - Hyaluronic acid inhibits the expression of u-PA, PAI-1, and u-PAR in human
synovial fibroblasts of osteoarthritis and rheumatoid arthritis.
AB - OBJECTIVE: Intraarticular administration of hyaluronic acid (HA) has been widely
used for the treatment of osteoarthritis (OA). Fibrinolysis is closely related to
the pericellular proteolysis involved in inflammation. However, the role of HA in
the regulation of fibrinolytic factors is not yet known. We investigated the
effect of HA on the pericellular fibrinolytic system of human synovial
fibroblasts derived from OA and rheumatoid arthritis (RA). METHODS: Human
synovial fibroblasts obtained from OA and RA were cultured in the presence and
absence of HA. The antigen of urokinase-type plasminogen activator (u-PA) and
plasminogen activator inhibitor-1 (PAI-1) were measured by ELISA, and u-PA
activity was evaluated by electrophoretic enzymography. The binding assay of u-PA
and the immunohistochemical analysis of u-PA were employed to detect u-PA
receptor (u-PAR). RESULTS: HA suppressed the secretion of both u-PA and PAI-1
antigens from the synovial fibroblasts of OA to their conditioned medium.
Suppression of u-PA activity in OA synovial fibroblasts was more marked than in
those of RA. The u-PA binding assay of OA and RA synovial fibroblasts revealed a
single class of binding site: dissociation constant (Kd) 23.7 nM, maximal number
of binding sites (Bmax) 3.11x10(4) binding sites/cell; Kd 16.5 nM, Bmax of
9.88x10(4) binding sites/cell, respectively. HA decreased Bmax in fibroblasts of
both OA and RA. Immunohistochemical analysis showed that u-PAR was constitutively
expressed in both synovial fibroblasts, but if these cells were treated with HA,
the decrease of the staining of u-PAR was more pronounced in the cells of RA than
in OA. CONCLUSION: Pericellular fibrinolytic activity mediated by the u-PA/u-PAR
system and PAI-1 was attenuated by HA in synovial fibroblasts derived from OA and
RA. Thus, HA may be a useful agent to inhibit the inflammation of arthritis.
PMID- 10782830
TI - Apoptotic chondrocytes from osteoarthrotic human articular cartilage and abnormal
calcification of subchondral bone.
AB - OBJECTIVE: Osteoarthrosis (OA) is accompanied by altered subchondral bone
remodeling. We investigated the role of chondrocytes in the mechanism of abnormal
cartilage calcification. METHODS: Knee articular cartilage samples from OA and
normal tissue were studied. Macroscopic and microscopic observations, alkaline
phosphatase staining for light and electron microscopy (bright and dark fields).
TUNEL technique, electron diffraction, and x-ray microanalyses were performed.
RESULTS: Chondrocytes from patients displayed a morphology of apoptosis and
showed abundant alkaline phosphatase (ALP)-rich matrix vesicles (MV) budding from
the plasma membrane with hydroxyapatite microcrystals on their surface. Farther
from the cells, hydroxyapatite crystals were detected on the MV surface and
increased as they approached the subchondral bone. The concentration of Ca and P
and their ratio increased inside the ALP-rich MV in relation to the proximity to
subchondral bone. In the OA subchondral bone the ratio Ca/P varied from 3.936 to
0.974. In normal tissue the ratio was very homogeneous (maximum 1.973, minimum
1.781). CONCLUSION: In situ, apoptotic chondrocytes correlate with factors known
to be involved in the calcification of the extracellular matrix. This suggests
that apoptosis is involved in the abnormal calcification of OA cartilage, and
consequently in the altered remodeling of the subchondral bone.
PMID- 10782831
TI - Preference for nonsteroidal antiinflammatory drugs versus acetaminophen and
concomitant use of both types of drugs in patients with osteoarthritis.
AB - OBJECTIVE: To analyze results of treatment of osteoarthritis (OA) with
acetaminophen and the nonsteroidal antiinflammatory drugs (NSAID) through a
patient survey. METHODS: A 15 minute telephone survey was conducted with 300
patients, including 172 with confirmed OA. RESULTS: Twenty-four percent of
patients who took acetaminophen rated it as "very helpful," compared to 31% for
ibuprofen, 30% for naproxen, and 56% for diclofenac. Drug continuation beyond 24
months was reported by 33% of patients for acetaminophen, 21% for ibuprofen, 17%
for naproxen, and 19% for diclofenac. Acetaminophen was significantly less likely
to be discontinued because of toxicity than NSAID. Patients who indicated that
they would not take a drug again, and therefore be unlikely to participate in a
clinical trial involving this drug, were 26% for acetaminophen, 40% for
ibuprofen, 38% for naproxen, and 28% for diclofenac. About 30% of patients who
took acetaminophen reported concurrent use of ibuprofen, naproxen, or diclofenac.
Among the 67% of patients who identified a drug as "most helpful," 80% named an
NSAID, compared to 20% who named acetaminophen or another analgesic as the "most
helpful" drug. CONCLUSION: Patients take many different drugs for OA, most of
which are not continued beyond 2 years. Many patients take both acetaminophen and
an NSAID. Most patients who identified a drug as "most helpful" named an NSAID
rather than acetaminophen or an analgesic drug. These findings may be of value in
further development of management strategies and guidelines for OA.
PMID- 10782832
TI - Bone mineral density in women with ankylosing spondylitis.
AB - OBJECTIVE: To determine bone mineral density (BMD) in premenopausal women with
early ankylosing spondylitis (AS). METHODS: Eighteen premenopausal women with AS
without syndesmophytes, interapophysiary arthritis, and/or coxofemoral joint
destruction were studied. BMD was analyzed at lumbar spine and femoral neck by
dual energy x-ray absorptiometry (Hologic QDR 1000). Z scores and T scores
related to the general Spanish population were recorded. Comparisons were
performed using the Student t test. Pearson's correlation coefficients were used
to study the correlation between BMD and the variables. Following the WHO
classification, osteopenia was diagnosed in patients with T score between -1 and
2.5 and osteoporosis in those with T score < -2.5 at lumbar spine or femoral
neck. RESULTS: The mean Z score for spine BMD was -0.19+/-0.7, and -0.03+/-0.85
for femoral neck BMD. There were no significant differences of Z score values
compared to the general population. No significant correlation was found between
BMD and disease duration, radiology sacroiliac score, and spine mobility.
Densitometry showed osteopenia in 2 patients and osteoporosis in none.
CONCLUSION: We found a slight reduction in BMD in premenopausal women with early
AS, but the difference was not statistically significant. We discuss the factors
related to its pathogenesis.
PMID- 10782833
TI - Bone mineral density and risk of incident and progressive radiographic knee
osteoarthritis in women: the Framingham Study.
AB - OBJECTIVE: To examine the relations of bone mineral density (BMD) and change in
BMD to risk of incident and progressive radiographic knee osteoarthritis (OA) in
a longitudinal cohort study. METHODS: Female participants aged 63 to 91 years
(mean age 71) in the Framingham Study received anteroposterior weight bearing
knee radiographs at biennial examinations 18 (1983-85) and 22 (1992-93). Knee
radiographs were given scores for global severity of OA (Kellgren-Lawrence scale:
range 0 to 4) and for the presence of osteophytes and joint space narrowing
(range 0 to 3). Femoral neck BMD was assessed using dual photon absorptiometry at
examination 20 and dual x-ray absorptiometry at examination 22. We examined the
relations of BMD at examination 20 and its change between examination 20 and
examination 22 to incident and progressive knee OA, as well as to worsening of
individual radiographic features adjusting for age, body mass index, and other
potential confounding factors. RESULTS: In total, 473 women (ages 63 to 91 yrs)
had complete assessments. Over 8 years of followup, risk of incident radiographic
knee OA increased from 5.6% among women in the lowest age-specific quartile of
BMD to 14.2, 10.3, and 11.8% among women in the 2nd, 3rd, and highest quartiles,
respectively. Multivariate adjusted OR of incident OA for each increase quartile
of BMD were 1.0, 2.5, 2.0, and 2.3, respectively (p for trend = 0.222). This was
mainly reflected in an increased risk of osteophyte development. However, risk of
progressive OA decreased from 34.4 to 22.0, 20.3, and 18.9% as BMD increased.
Compared to those in the lowest quartile of BMD, adjusted OR for progressive
disease were 0.3, 0.2, and 0.1 among women in the 2nd, 3rd, and highest quartiles
(p for trend <0.001), respectively, mainly due to its effect on lowering the risk
of joint space loss. Compared to those who lost BMD >0.04 g/cm2 over the followup
period, women who gained BMD were at increased risk of incident but at a
significantly decreased risk of progressive knee OA. BMD change was not
associated with osteophyte development, but gain in BMD lowered the risk of joint
space loss. CONCLUSION: High BMD and BMD gain decreased the risk of progression
of radiographic knee OA, but may be associated with an increased risk of incident
knee OA. The protective effect was mainly through its influence on reducing the
risk of joint space loss. Our results offer insights into how bone may affect the
course of the most common joint disease, and thus may have potential therapeutic
implications.
PMID- 10782834
TI - Comparison of nasal and oral tolerance for the prevention of collagen induced
murine arthritis.
AB - OBJECTIVE: Administration of bovine type II collagen (CII) or of its peptide
either orally or nasally has been reported to suppress the development of
collagen induced arthritis (CIA) in mice and rats. We examined the inhibitory
effects of CII delivered by each route on CIA in DBA/1J mice to determine which
route was superior. METHODS: Male mice were injected twice with CII in Freund's
complete adjuvant to induce CIA. Before induction of CIA, 1, 10, or 40 microg of
CII were administered nasally 15 times and 10, 100, 500, or 1000 microg of CII
were given 10 times orally. The development of arthritis, arthritis score, CII
specific delayed-type hypersensitivity (DTH) response, and CII-specific antibody
levels were examined. RESULTS: Nasal administration of 10 microg of CII 15 times
had the most prominent suppressive effects, reducing disease incidence by 50% and
inhibiting both CII-specific IgG antibody and DTH responses. Of all the mice
undergoing oral administration, those receiving 500 microg of CII 10 times showed
the greatest suppressive potential. However, the treatment only delayed disease
onset for roughly 3 weeks, lowering CII-specific IgG antibody levels but failing
to suppress DTH responses. CONCLUSION: Nasal administration of CII reduced CIA
development and inhibited CII-specific T cell and antibody responses to a greater
degree than did oral administration.
PMID- 10782835
TI - Community based epidemiological study on hyperuricemia and gout in Kin-Hu,
Kinmen.
AB - OBJECTIVE: This is a population survey conducted in 1991-92 among residents aged
> or =30 years in Kin-Hu, Kinmen, with a 77.7% response rate to study the
prevalence of hyperuricemia and hyperuricemia associated gout. A stratified
analysis based on sex and age was used to assess the interaction and analyze the
associated risk factors for hyperuricemia and gout. METHODS: Hyperuricemia was
defined as uric acid > or =7.0 mg/dl for men and > or =6.0 mg/dl for women. Gout
was clinically diagnosed by a senior rheumatologist based on patient's history
and examination according to the clinical criteria of Wallace. Basic demographic
and lifestyle variables as well as biochemical data were collected. RESULTS: The
prevalence of hyperuricemia was 25.8% (391/1515) in men and 15.0% (250/1670) in
women. The prevalence of gout among hyperuricemic subjects was 11.5% for men and
3% for women. According to age spectrum, the risk factor for hyperuricemia was
hyperlipidemia in young adults (30-39 yrs); lifestyle and some clinical syndromes
played a significant role in middle aged persons (40-59 yrs). The different risk
factors between the sexes in middle age were alcohol consumption effect in men
and menopause effect in women. Impaired renal function and use of diuretics
became the important factors in the elderly (> or =60 yrs). The risk factors for
gout among either the general population or subjects with hyperuricemia were
concentration of serum uric acid, alcohol consumption, and central obesity.
CONCLUSION: Risk factors for hyperuricemia tended to be different with respect to
sex and age. Alcohol consumption and central obesity were independent predictors
of gout among hyperuricemic subjects irrespective of uric acid level.
PMID- 10782836
TI - Attributions in chronic fatigue syndrome and fibromyalgia syndrome in tertiary
care.
AB - OBJECTIVE: To evaluate the attributions of patients with chronic fatigue syndrome
(CFS) and fibromyalgia (FM) consulting at a university fatigue and pain clinic.
METHODS: Consecutive attenders (n = 192) who met the CFS criteria (n = 95) or FM
criteria (n = 56) or who had medically unexplained chronic pain and/or fatigue
without meeting both criteria (CPF) (n = 41) were evaluated. All subjects
completed an extended form of the Cause of Illness Inventory. Descriptive
statistics, frequency analyses, chi-square tests, one-way analysis of variance,
and sequential Fisher least significant difference tests were performed. RESULTS:
In total, 48 patients reported physical causes only and 10 patients psychosocial
causes only; the majority (70%) mentioned both types of causes. With regard to
the contents, "a chemical imbalance in my body" (61%), "a virus" (51%), "stress"
(61%), and "emotional confusion" (40%) were reported most frequently. The
diagnostic label did not have a significant influence on number and type of
attributions. Small to moderate effect sizes were registered concerning the
association of specific attributions and diagnosis, sex, duration of the
symptoms, contact with a self-help group, and premorbid depression. CONCLUSION:
The majority of patients with CFS, FM, and CPF reported a great diversity of
attributions open to a preferably personalized cognitive behavioral approach.
Special attention should be paid to patients with symptoms existing for more than
one year and those who had previous contacts with a self-help group. They
particularly show external, stable, and global attributions that may compromise
feelings of self-efficacy in dealing with the illness.
PMID- 10782837
TI - The role of generalized pain and pain behavior in tender point scores in
fibromyalgia.
AB - OBJECTIVE: To determine and assess the significance of the independent role of
pain, pain behavior, depression, and weekly stress in tender point scores in
objectively diagnosed fibromyalgia (FM) patients. METHODS: One hundred eleven
patients with FM recruited from the community and private and university based
clinics participated in a comprehensive evaluation of their pain, psychological
distress, and pain behavior. Tender point assessment was carried out across 18
discrete sites according to American College of Rheumatology criteria. Pain was
assessed with a composite index of 4 pain measures; psychological distress
consisted of measures of stress and depression, and pain behavior was measured by
an objective index derived from a 10 minute videotaped sequence in which 5 pain
behaviors were recorded. RESULTS: Multiple regression analyses revealed that high
pain, high pain behavior, and shorter illness duration were related independently
to tender point scores. Measures of depression and weekly stress were not
independently related to tender point scores. CONCLUSION: Tender point scores are
related to generalized pain and pain behavior tendencies in patients with FM, and
do not independently reflect generalized psychological distress.
PMID- 10782838
TI - Skeletal muscle infarction in diabetes mellitus.
AB - OBJECTIVE: To analyze the risk factors, clinical features, and methods of
diagnosis of diabetic muscle infarction (DMI). METHODS: Three patients with
diabetes mellitus (DM) and skeletal muscle infarction were studied, and 49
additional cases reported in the English literature (Medline database search)
were reviewed. RESULTS: Review of all 52 patients with DMI revealed a number of
typical features: equal sex distribution; mean age 41.5 years (range 19-81 yrs);
a number of risk factors [long duration of DM (mean 15.2 yrs), poor control and
microvascular diabetic complications (neuropathy, retinopathy, nephropathy)
(94%), and insulin dependent type I DM (77%)]; a characteristic clinical
presentation with painful diffuse muscle swelling (100%); and sometimes a muscle
mass (44%), predilection for quadriceps (62%), hip adductors (13%) and leg
muscles (13%), elevated serum creatine phosphokinase (47%), abnormal sonograms
(81%), abnormal magnetic resonance image (MRI) findings (100%), typical
histopathologic findings of a muscle infarct (100%) (ultrastructural evidence of
microangiography in one patient); and a tendency toward spontaneous resolution
although recurrences are common (51%). CONCLUSION: Skeletal muscle infarction is
a rare complication of long standing, poorly controlled DM associated with
multiple end organ microvascular sequelae. Increased clinical awareness is
important for early recognition, particularly in a diabetic patient presenting
with a painful thigh or leg swelling. MR imaging is the diagnostic study of
choice, and in the appropriate clinical setting, may obviate the need for a
muscle biopsy.
PMID- 10782839
TI - Validation of the proposed ILAR classification criteria for juvenile idiopathic
arthritis. International League of Associations for Rheumatology.
AB - OBJECTIVE: The new International League of Associations for Rheumatology (ILAR)
classification criteria were proposed to facilitate communication among pediatric
rheumatologists. Before they are applied in daily practice they should be
clinically validated. METHODS: We retrospectively applied the proposed criteria
on our pediatric rheumatology patient population seen between June 1 and August
31, 1998. RESULTS: We saw 67 patients with oligoarticular (oJRA), 6 with
polyarticular/RF negative (pJRA), and 8 with systemic juvenile rheumatoid
arthritis (sJRA), all classified according to American College of Rheumatology
criteria, 5 with juvenile psoriatic arthritis (PsA) according to the Vancouver
criteria, and 11 with juvenile spondyloarthritis (SP) according to the European
Spondylarthropathy Study Group preliminary criteria. Of the 97 patients, 85 could
be clearly classified according to the ILAR criteria. Twelve patients (12%) were
classified as "other." Six patients could not be classified as "oligo" because of
a family history of psoriasis, and did not fulfill the criteria for PsA either.
All 6 "other" patients fulfilled criteria for 2 different categories. CONCLUSION:
With this ILAR proposed classification criteria 88% of patients could be
classified. In patients classified as "other," the psoriatic trait caused the
most difficulty in classification.
PMID- 10782841
TI - The value of echocardiography in the diagnosis and followup of rheumatic carditis
in children and adolescents: a 2 year prospective study.
AB - OBJECTIVE: To evaluate echocardiographic/Doppler findings in patients with
rheumatic fever whether or not clinical manifestations of carditis were present,
and the followup of these findings 24 months after the acute phase. METHODS:
Twenty-two patients with rheumatic fever (13 boys, 9 girls, mean age 11.0 years)
were evaluated at baseline (at diagnosis) and after 3 and 6 mo of disease.
Eighteen patients were reevaluated 24 mo later. The assessment included physical
and cardiac examination, electrocardiogram, chest radiography, and color
ECHO/Doppler performed blindly by different investigators. The control group
included 15 healthy children. RESULTS: We observed clinical carditis in 8
patients (36.4%): Group 1, all with ECHO abnormalities. We observed no clinical
cardiac manifestations in 14 patients (Group 2), but 5 (35.7%) had positive
ECHO/Doppler abnormalities that persisted at least 6 mo in followup assessments.
Mitral and aortic were the most frequently involved valves. In Group 1 we
observed normalization of the ECHO/Doppler in 3 patients, improvement in 2, no
change in 2, and worsening in one. Twelve of 14 patients without clinical
carditis were reevaluated, including the 5 patients with ECHO/Doppler
abnormalities during the initial evaluations; normalization or improvement was
observed in 2 patients, no change in 2, and worsening in one. We observed no
ECHO/Doppler abnormalities in the control group. CONCLUSION: This blind
prospective study suggests the existence of asymptomatic carditis in some
patients with rheumatic fever and the role ECHO/Doppler investigation could play
in diagnosis and followup.
PMID- 10782842
TI - Seropositive rheumatoid arthritis with dermatomyositis sine myositis,
angioimmunoblastic lymphadenopathy with dysproteinemia-type T cell lymphoma, and
B cell lymphoma of the oropharynx.
AB - Angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) is a rare
lymphoproliferative disorder that often progresses to high grade T cell lymphoma.
We describe a 63-year-old woman with longstanding seropositive rheumatoid
arthritis who developed fever, cutaneous findings of dermatomyositis, a diffuse
pruritic maculopapular rash, enlarged lymph nodes, polyclonal elevated serum
gammaglobulins, and an IgG lambda paraprotein. Lymph node biopsies yielded tissue
with characteristic changes of AILD and T cell lymphoma. Interleukin 6 (IL-6) was
present during the early, active phase of disease, and circulating IL-6 and IL-2
were detected one month before tumor recurrence. Two years after AILD and T cell
lymphoma were diagnosed, she developed a B cell lymphoma that involved the
oropharynx.
PMID- 10782840
TI - Bone mineral content and bone mineral metabolism: changes after growth hormone
treatment in juvenile chronic arthritis.
AB - OBJECTIVE: To determine whether growth hormone (rhGH) affects bone mineral
metabolism and bone mineral content (BMC, g/cm) in a therapeutic trial of
recombinant growth hormone in growth retarded children with juvenile chronic
arthritis (JCA) treated with steroid. METHODS: BMC was measured in 20 children
(of whom 17 were treated with corticosteroid) before and after one year of rhGH.
Children were randomized to receive either low dose (12 IU/m2/week) or high dose
(24 IU/m2/week) for one year. Three monthly assessments were made of disease
activity and anthropomorphic measurements. Blood and urine samples were also
obtained to measure indicators of disease activity, bone remodeling, and vitamin
D and parathyroid hormone (PTH) status. RESULTS: BMC increased during the
treatment period and correlated with increasing height. Osteocalcin levels,
normally indicators of bone formation, increased after rhGH treatment and
correlated significantly with height velocity, particularly for the high dose
treatment group. In contrast, osteocalcin levels were negatively correlated with
C-reactive protein levels, both before and during treatment. Height velocity,
vitamin D, PTH, and osteocalcin levels were significantly lower than age matched
controls before treatment. CONCLUSION: Steroid treated children with both JCA and
severe growth retardation have reduced vitamin D, PTH, and osteocalcin levels.
After treatment with rhGH, height velocity increased, as did BMC. Growth hormone
might be a useful adjunct in the treatment of severe growth retardation and
osteoporosis in children with JCA. The longterm benefits of rhGH in the treatment
of osteoporosis remain unclear.
PMID- 10782843
TI - Hypocomplementemic panniculitis with paraprotein.
AB - Two episodes of severe panniculitis accompanied by fever and an acute phase
response were the main clinical features in a patient who had an unusual IgG
kappa paraprotein. Both episodes responded promptly to steroids. Complement
proteins of the early classical pathway were depleted in the patient's serum, and
in vitro experiments indicated that the IgG kappa paraprotein activated
complement directly. The association of recurrent panniculitis and
paraproteinemia-hypocomplementemia has been described in 2 other patients. It
should be recognized since its response to steroids is immediate.
PMID- 10782844
TI - Synovial cyst of the proximal tibiofibular joint.
AB - We describe a case of an unusual synovial cyst originating from the proximal
tibiofibular joint. This cyst presented as a painless, soft tissue swelling just
distal to the fibular head. We review the literature on this topic regarding
clinical presentation, imaging, and management.
PMID- 10782845
TI - Oral granuloma associated with intestinal Behcet's disease.
PMID- 10782846
TI - Intravenous gammaglobulin in the treatment of central nervous system vasculitis
associated with Sjogren's syndrome.
PMID- 10782848
TI - Innovative strategies for trial design.
AB - Most clinical trial designs used in evaluating therapies require large numbers of
subjects. Childhood rheumatic diseases are rare and large numbers of subjects are
not available. We have largely been unsuccessful in developing evidence based
therapeutics for pediatric rheumatology. Because these diseases are rare, it is
important for each clinical trial to enroll all possible subjects, and it is
important to extract as much information as possible from each subject. Placebo
controlled randomized studies are sometimes seen as unacceptable to physicians
and patients. We need study designs that are more acceptable and that will
increase accrual. Some clinical trial designs, especially those that involve
crossover treatment assignments, can increase the amount of information that each
subject contributes. These types of studies can only be used for treatments that
are reversible. For treatments that may permanently affect the disease course, I
propose the randomized placebo phase design as one way of increasing study
acceptability and accrual.
PMID- 10782847
TI - A new clinical manifestation of the Dobrin's syndrome?
PMID- 10782849
TI - Outcomes assessment: meeting the challenge of accountability in pediatric
rheumatology.
AB - As providers of health services, pediatric rheumatologists must learn to manage
financial risk, deliver quality services, and provide value to a number of
healthcare stakeholders. What these deliverables mean in a competitive healthcare
environment are explained. Ways to achieve these goals, provide excellent care to
children with rheumatic conditions, and differentiate pediatric rheumatologists
in the marketplace are discussed.
PMID- 10782850
TI - Update on functional assessment tools.
AB - In recent years, there has been a tremendous growth in the development of
measurement instruments that evaluate health status, functional status,
disability, and quality of life in adults with rheumatic diseases. In the past
decade, similar measures have been developed for application in children with
rheumatic diseases. These include the Childhood Arthritis Impact Measurement
Scales (CHAIMS), the Childhood Health Assessment Questionnaire (CHAQ), the
Juvenile Arthritis Functional Assessment Report (JAFAR), the Juvenile Arthritis
Self-report Index (JASI), the Juvenile Arthritis Quality of Life Questionnaire
(JAQQ), and the Childhood Arthritis Health Profile (CAHP). The latter 2
instruments assess health related quality of life (HRQOL) and they are discussed
here. The need to adapt this kind of instrument for use in an international
climate creates an interesting dilemma and this is discussed.
PMID- 10782851
TI - Premature atherosclerosis in systemic lupus erythematosus.
AB - Premature atherosclerosis is a recognized complication of systemic lupus
erythematosus (SLE). Since life expectancy in SLE is improving, premature
atherosclerosis is emerging as an ever more important clinical issue.
Atherosclerosis begins in the pediatric age group, and interventions directed at
prevention should begin in childhood as well. Possible etiologies include
dyslipoproteinemia (DL) from the underlying chronic inflammatory disease or from
corticosteroid therapy, hypercoagulation due to antiphospholipid antibodies or
nephrotic syndrome, vasculitis, and hypertension. A relationship between DL and
presence of anticardiolipin antibodies (aCL) has been reported. Dietary therapy
is helpful, but many patients continue to have significant DL after both dietary
modification and fish oil supplementation. Lipid lowering drugs may be indicated
in this subgroup. Potential mechanisms of the DL are discussed. Other strategies
to prevent atherosclerosis and its complications are reviewed.
PMID- 10782852
TI - The antiphospholipid syndrome: immunologic and clinical aspects. Clinical
spectrum and treatment.
AB - Antiphospholipid antibodies (aPL) have been associated with clinical conditions
that involve arterial or venous thrombotic events and pregnancy morbidity
including fetal loss and preeclampsia. These antibodies are detected by various
functional tests for the lupus anticoagulant, the anticardiolipin ELISA, the anti
beta2-glycoprotein I ELISA, or ELISA tests for other aPL. The pathogenic
mechanisms are poorly understood. A "2 hit" hypothesis has been entertained in
which there is underlying vascular (endothelial) damage, and in the presence of
an aPL, a thrombotic complication emerges. Although the role of immunologic
processes and autoimmunity appears important, immunosuppressive therapy has not
proven very effective. Treatment options are limited to antiplatelet therapy
(primarily for arterial events) and anticoagulation (with coumadin, heparin, or
low molecular weight heparins) because of lack of understanding of the inciting
factors and the pathogenesis of the process.
PMID- 10782853
TI - The pain puzzle: a visual and conceptual metaphor for understanding and treating
pain in pediatric rheumatic disease.
AB - Chronic pain is a primary clinical manifestation of pediatric rheumatic diseases
that for some children persists into adulthood and is associated with increased
disability. The "pain puzzle" is presented as a visual and conceptual metaphor
for understanding and treating pediatric rheumatic disease related pain. This
metaphor is consistent with a biobehavioral model of pain that focuses on the
unique and interactive components of nociceptive activity, emotions, cognitions,
and behavior in the experience of pain. We describe the parts of the pain puzzle
and review the implications for treating pediatric rheumatic disease related
pain.
PMID- 10782854
TI - Bone mineral status in juvenile rheumatoid arthritis.
AB - Osteoporosis can be thought of as a disease of childhood with manifestations in
the adult years. One strategy in prevention of osteoporosis is to maximize peak
bone mass with interventions focused during the childhood and adolescent years,
taking advantage of this unique window of opportunity to maximize bone mass
accrual, maximize peak bone mass, and theoretically decrease fracture risk for
life. Factors important in the development of peak bone mass in children are
reviewed. Studies examining bone metabolism and bone density in children with
juvenile rheumatoid arthritis (JRA) are summarized. There is much work to be done
before the best treatments for the osteoporosis of JRA are defined. Optimizing
calcium intake and physical activity, along with corticosteroid avoidance and
control of disease activity, is sound management for children with JRA.
PMID- 10782855
TI - Effects of rheumatic disease and corticosteroid treatment on calcium metabolism
and bone density in children assessed one year after diagnosis, using stable
isotopes and dual energy x-ray absorptiometry.
AB - OBJECTIVE: To evaluate calcium (Ca) metabolism and bone mineral density (BMD) in
children with rheumatic disease (RD) at diagnosis and one year later, and effects
of different therapies. METHODS: We used dual tracer isotope studies and dual
energy x-ray absorptiometry (DEXA) to measure Ca metabolism and BMD in 13
children with RD at diagnosis and one year later. Seven subjects were treated
with steroids (RD-ST), 6 with antiinflammatory agents (RD-NS), excluding
steroids. RESULTS: Ca balance data for RD subjects were not significantly
different from data reported previously for healthy sex and age matched controls.
True Ca absorption (Va) was slightly but not significantly greater at study entry
in RD-NS subjects (313+/-67 vs 239+/-112 mg/day in RD-ST subjects; p = 0.13).
Calculated Ca balance retention (Vbal) was higher at entry in RD-NS (200+/-51 vs
RD-ST 60+/-125 mg/day; p = 0.08). One year later, Vbal remained higher in RD-NS
(202+/-77 mg/day vs RD-ST 101+/-157 mg/day; p = 0.02). BMD was similar in both
groups at entry (RD-NS 0.81+/-0.06 g/cm2 vs RD-ST 0.89+/-0.1 g/cm2; p = 0.07).
One year later, BMD was 0.86+/-0.6 g/cm2 in RD-NS versus 0.89+/-0.08 g/cm2 in RD
ST; p = 0.07. Ca kinetic and DEXA studies did not reveal significant alteration
of Ca kinetics or significantly lower BMD in steroid treated subjects versus non
steroid treated subjects. However, slightly lower Va and Vbal indicated a
possible risk of bone demineralization in steroid treated subjects. CONCLUSION:
Children with RD who are treated with steroids may be at greater risk of bone
demineralization at diagnosis that persists through the first year. However, bone
loss may take years to manifest when measured by quantitative methods such as
DEXA.
PMID- 10782856
TI - An overview of amplified musculoskeletal pain syndromes.
AB - Children may have a wide variety of amplified musculoskeletal pain syndromes that
may or may not be associated with overt autonomic signs and may be diffuse or
localized to one body part. It is most common in pre- to adolescent girls.
Hallmarks of the diagnosis include increasing pain over time, allodynia, an
incongruent affect, disproportional dysfunction, and the absence of other causes.
Psychological distress within the child or family is apparent in most, but not
all, since it also is associated with injury or illness. Once the diagnosis is
established, all medicines and testing are stopped. A sympathetically driven pain
model is used to explain the pain to make it understandable. Treatment is an
intense exercise program; ours is 5 hours daily. We focus on functional aerobic
training specifically using the involved body part such as sports related drills,
running, play activities, and swimming. Allodynia is treated with desensitization
such as towel rubbing. A psychological evaluation is done and specific
psychotherapy is recommended if indicated. The average duration of the daily
program is 2 weeks with a 1 hour home program being done for another 2 to 8
weeks. After one month roughly 80% of the children have no pain and are fully
functional, another 15% are fully functional with mild or recurrent pain; 5% are
not better. Significant relapses are infrequent; 15% require retreatment. Five to
10% of the children will develop a different symptom of psychological distress.
At 5 years, 90% are doing well.
PMID- 10782858
TI - Gene therapy for juvenile rheumatoid arthritis?
AB - Gene therapy shows promise as a means of improving the treatment of a number of
rheumatic diseases, including adult rheumatoid arthritis (RA). We summarize these
developments and discuss the merits of extending such approaches to the treatment
of juvenile RA. The special issues that arise when treating children by
experimental new procedures predicate a cautious approach using strategies first
shown to be safe in adults. Patients with severe, erosive, nonremitting
pauciarticular juvenile RA might be suitable first candidates for gene therapy.
PMID- 10782859
TI - Unfinished business: challenges into the next century.
PMID- 10782857
TI - The role of bone marrow transplantation in pediatric rheumatic diseases.
AB - Recent advances in bone marrow transplantation have led to improvement in its
safety and it is now being used for rheumatologic disorders resistant to standard
medical management. I describe some of the theories underlying its use and review
the current data supporting its use.
PMID- 10782860
TI - Quo vadis? Whither goest thou, rheumatologist?
PMID- 10782861
TI - Initial steps in lymph node metastasis formation in an experimental system:
possible involvement of recognition by macrophage C-type lectins.
AB - We used histological observations and experiments with fluorescent cell tracers
to investigate the roles of tissue macrophages in recognition through a
galactose/N-acetylgalactosamine-specific C-type lectin (mMGL) in lymph node
metastasis formation by mouse ovarian tumor OV2944-HM-1 (HM-1) cells. Lymph node
metastasis from subcutaneous sites was shown to be initiated by the entry of
tumor cells into the subcapsular sinus of lymph nodes where mMGL-positive cells
were mainly located. To investigate whether mMGL-positive cells contributed to
host resistance against lymph node metastasis, we repeatedly treated mice bearing
transplanted tumors with an mMGL-blocking monoclonal antibody that was known to
inhibit mMGL binding to its ligands. The number of HM-1 cells recovered from
lymph nodes 2 weeks after subcutaneous injections was significantly greater when
the mice were treated with the blocking anti-mMGL antibody. These results
suggested that mMGL-positive macrophages contributed to the host's defense
against lymph node metastasis.
PMID- 10782863
TI - Immune gene therapy of experimental mouse brain tumor with adenovirus-mediated
gene transfer of murine interleukin-4.
AB - We examined the antitumor activity of replication-deficient adenoviral vectors
carrying the murine interleukin-4 (IL-4) gene (AdCIL4) using a syngeneic brain
tumor model in mice. Mice implanted with malignant astrocytoma cells infected
with AdCIL4 survived significantly longer than those in the control groups.
Immunocytochemical analysis of the tumors showed that AdCIL4 caused the strong up
regulation of MHC class II antigen expression by the tumor cells and macrophages,
and consequent infiltration by CD8+ T lymphocytes. This study demonstrates the
efficacy of IL-4 gene transfection mediated by adenoviral vectors for
intracerebral tumor and characterizes the immunoreaction caused by AdCIL4.
PMID- 10782862
TI - B7-2 expression on tumor cells is important for the acquisition of cytotoxic T
lymphocyte activity by spleen cells from low-dose-melphalan-treated MOPC-315
tumor bearers via a mechanism that requires either B7-1 or B7-2 expression on
host antigen-presenting cells.
AB - We have previously shown that B7-2 (CD86) and, to a lesser extent, B7-1 (CD80)
contribute to the curative effectiveness of low-dose melphalan (L-phenylalanine
mustard) for mice bearing a large MOPC-315 tumor under conditions that lead to
the acquisition of potent cytotoxic T lymphocyte (CTL) activity at the tumor
site. Since B7-1 and B7-2 are expressed on both tumor cells and host antigen
presenting cells (APC), the current studies were undertaken to examine the
relative importance of each costimulatory molecule on tumor cells and on host APC
for the acquisition of anti-MOPC-315 CTL activity. Utilizing an in vitro system
for the acquisition of CTL activity, we found that B7 expression on host APC is
important for the development of CTL activity in stimulation cultures of spleen
cells from low-dose-melphalan-treated MOPC-315 tumor bearers, although the
expression of either B7-1 or B7-2 is sufficient. In addition, we found that B7-2,
which is expressed at high levels on stimulator tumor cells, but not B7-1, which
is expressed at much lower levels, is also important for the acquisition of CTL
activity. However, the vast majority of the CTL activity acquired in vitro in
response to stimulation with the B7-2-expressing MOPC-315 tumor cells was found
to depend on B7-expressing host APC. Thus, it is likely that B7-2, which is
expressed at high levels on MOPC-315 tumor cells, promotes the rapid lysis of
MOPC-315 stimulator tumor cells, thereby making tumor-associated antigens more
readily available for efficient presentation by B7-expressing host APC which, in
turn, stimulate the acquisition of CTL activity by spleen cells from low-dose
melphalan-treated MOPC-315 tumor bearers.
PMID- 10782864
TI - Immunotherapy with vaccines combining MHC class II/CD80+ tumor cells with
interleukin-12 reduces established metastatic disease and stimulates immune
effectors and monokine induced by interferon gamma.
AB - Because they are difficult to treat, animal models of widespread, established
metastatic cancer are rarely used to test novel immunotherapies. Two such mouse
models are used in this report to demonstrate the therapeutic efficacy and to
probe the mechanisms of a novel combination immunotherapy consisting of the
cytokine interleukin-12 (IL-12) combined with a previously described vaccine
based on MHC class II, CD80-expressing cells. BALB/c mice with 3-week established
primary 4T1 mammary carcinomas up to 6 mm in diameter and with extensive,
spontaneous lung metastases show a significant reduction in lung metastases
following a 3-week course of immunotherapy consisting of weekly injections of the
cell-based vaccine plus injections of IL-12 three times per week. C57BL/6 mice
with 7-day established intravenous B16 melF10 lung metastases show a similar
response following immunotherapy with IL-12 plus a vaccine based on B16 MHC class
II, CD80-expressing cells. In both systems the combination therapy of cells plus
IL-12 is more effective than IL-12 or the cellular vaccine alone, although, in
the 4T1 system, optimal activity does not require MHC class II and CD80
expression in the vaccine cells. The cell-based vaccines were originally designed
to activate tumor-specific CD4+ T lymphocytes specifically and thereby provide
helper activity to tumor-cytotoxic CD8+ T cells, and IL-12 was added to the
therapy to facilitate T helper type 1 lymphocyte (Th1) differentiation. In vivo
depletion experiments for CD4+ and CD8+ T cells and natural killer (NK) cells and
tumor challenge experiments in beige/nude/XID immunodeficient mice demonstrate
that the therapeutic effect is not exclusively dependent on a single cell
population, suggesting that T and NK cells are acting together to optimize the
response. IL-12 may also be enhancing the immunotherapy via induction of the
chemokine Mig (monokine induced by interferon gamma), because reverse PCR
experiments demonstrate that Mig is present in the lungs of mice receiving
therapy and is most likely synthesized by the tumor cells. These results
demonstrate that the combination therapy of systemic IL-12 and a cell-based
vaccine is an effective agent for the treatment of advanced, disseminated
metastatic cancers in experimental mouse models and that multiple effector cell
populations and anti-angiostatic factors are likely to mediate the effect.
PMID- 10782865
TI - Tumor-derived Fas ligand induces toxicity in lymphoid organs and plays an
important role in successful chemotherapy.
AB - Recent studies have suggested that Fas ligand (FasL-) tumor cells can induce
apoptosis in Fas+ T cells. However, the effect of growth of FasL+ tumors in vivo,
on lymphoid tissues of the host is not clear and therefore was the subject of
this investigation. Injection of FasL+ LSA tumor caused a significant decrease in
cellularity of the thymus and spleen, resulting from marked apoptosis, in
syngeneic C57BL/6+/+ (wildtype) but not C57BL/6-lpr/lpr (Fas-deficient) mice. The
tumor-induced toxicity resulted from tumor-derived rather than host-derived FasL,
inasmuch as LSA tumor growth in C57BL/6-gld/gld (FasL-defective) mice, induced
marked apoptosis and toxicity in the thymus and spleen. The LSA tumor growth
induced a significant decrease in the percentage of CD4+CD8+ T cells in the
thymus of C57BL/6+/+ mice and an increase in the percentage of CD4+, CD8+ and CD4
CD8- T cells. Of the four subpopulations tested, the CD4+CD8+ T cells showed
maximum apoptosis. The LSA (FasL+) but not P815(FasL-) tumor cell lysates and
culture supernatants induced marked apoptosis in Fas+ thymocytes, when tested
both in vitro and in vivo. The LSA-tumor-induced apoptosis in vitro was inhibited
by antibodies against FasL or by caspase and other inhibitors of apoptosis.
Chemotherapy of LSA-tumor-bearing C57BL/ 6+/+ mice at advanced stages of tumor
growth failed to cure the mice, whereas, more than 80% of LSA-tumor-bearing
C57BL/6-lpr/lpr mice, similarly treated, survived. Together, the current study
demonstrates that FasL produced by LSA tumor cells is functional in vivo and can
cause severe toxicity in lymphoid organs of the host. Also, Fas/FasL interactions
may play an important role in the successful chemotherapy of FasL-bearing tumor.
PMID- 10782866
TI - Phase I trial of interleukin-2 and high-dose arginine butyrate in metastatic
colorectal cancer.
AB - INTRODUCTION: Interleukin-2 (IL-2) and sodium butyrate allow rats to be cured of
peritoneal carcinomatosis from colon cancer. We performed a phase I trial of IL-2
and high-dose arginine butyrate (ArgB) in patients with advanced metastatic
colorectal cancer. PATIENTS AND METHODS: From April to July 1997, six patients
were included in the trail; they had a median age of 52 years, four had a
performance status of 0, two had a performance status of 1 with normal biological
functions. All patients had received at least two prior lines of chemotherapy. A
fixed dose of 18 MIU/m2 IL-2,was administered by subcutaneous injection and ArgB
was delivered via continuous intravenous infusion on days 1-6 with escalating
doses starting at 2 g kg(-1) day(-1). RESULTS: The planned dose escalation was
not possible because of toxicities. A daily ArgB dose of 2 g/kg was delivered for
nine cycles. Level 2 (4 g/kg) could not be delivered in three of the six patients
because of liver toxicity. The dose-limiting toxicities were fatigue and liver
function disturbances. The maximum tolerated dose for ArgB was 3 g kg(-1) day(
1), in combination with IL-2 at 12 MIU m2 day(-1). No clinical response was seen.
Pharmacokinetic analysis showed large intra- and interindividual variations.
CONCLUSION: This schedule with a high dose of ArgB proved to be highly toxic with
liver insufficiency. We will be running another trial with lower doses of ArgB
calculated from the schedule used in the experimental model, starting at a dose
of 20 mg kg(-1) day(-1) for ArgB and 200000 UI kg(-1) day(-1) IL-2, every 8 h.
PMID- 10782867
TI - Top 10 tips for successful grantsmanship.
PMID- 10782868
TI - Application of the Omaha System in acute care.
AB - Although effective as a standardized language for documentation in community and
public health settings, the Omaha System has not been evaluated in acute care
settings. The purpose of this study was to evaluate the utility of the Omaha
System to code the terms used by nurses when documenting hospital care. The
nursing documentation in 30 hospital records was content analyzed for signs and
symptoms, patient problems, and nursing interventions, then coded into the
categories of the Omaha System. Degree of match was evaluated using concept match
scores, and utility was determined using empirical, operational, and pragmatic
criteria. Study findings suggest several strengths (i.e., high reliability, coded
97% of the problems, easy to use) and some limitations (lack of mutual
exclusivity among terms, lack of semantic clarity, the need for three new
problems). This study has important implications in demonstrating the utility of
the Omaha System for possible expansion into acute care to standardize
communication between the hospital setting and home care.
PMID- 10782869
TI - Age-related changes in initiation and maintenance of sleep: a meta-analysis.
AB - The purpose of this meta-analysis was to determine the magnitude of change over
the adult life span in four key sleep characteristics and to explore research
design features that may account for variability in reported age-related sleep
change. Forty-one published studies (combined N = 3293) provided 99 correlational
effect sizes. Waking frequency and duration increased with age as previously
concluded by narrative reviewers. Although narrative reviewers were less certain
whether nighttime sleep amount or the ability to initiate sleep decreased with
age, the meta-analysis suggested that both decreased. When sleep variables were
measured by polysomnography rather than self-report, larger age-related changes
were found. Few researchers who studied normal sleep controlled for important
health moderators or studied women.
PMID- 10782870
TI - Acculturation and perinatal health outcomes among rural women of Mexican descent.
AB - Research has shown that health outcomes for urban women of Mexican descent are
related to acculturation. The purpose of this research was to compare perinatal
outcomes of 773 women of Mexican descent who gave birth in three rural northern
California hospitals, in relation to acculturation measured three different ways:
by place of birth, by language spoken, and by the two factors combined as an
Acculturation Index (AI). The prenatal and birth records of 773 Mexico-born or
U.S.-born women of Mexican descent were reviewed. Results showed that language
spoken was a less useful indicator of acculturation associated with perinatal
complications than place of birth or the AI. The categorization of acculturation
with the AI enhanced understanding of more specific groups of rural women and
their particular health outcomes.
PMID- 10782871
TI - Narratives of smoking relapse: the stories of postpartum women.
AB - Many women who stop smoking during pregnancy relapse soon after the birth of
their infants. Using narrative research, experiences of smoking relapse were
explored using interviews with 27 postpartum women. The stories of relapse were
analyzed to identify important components, paying attention to commonalities,
differences, and areas of emphasis. Five general story lines were identified: (1)
controlling one's smoking (starting with a "puff" and consciously restricting the
amount smoked); (2) being vulnerable to smoking(relapsing because of an inability
to resist cigarettes); (3) nostalgia for one's former self(relapsing to recapture
feelings of freedom and happier times); (4) smoking for relief(relapsing to
manage emotions and stress); and (5) never really having quit (relapsing because
they did not quit for themselves). The findings of this study provide support for
the claim that the experiences of smoking cessation and relapse among postpartum
women may be unique and, consequently, may require specialized intervention.
PMID- 10782872
TI - Challenging the rules: women's prodromal and acute symptoms of myocardial
infarction.
AB - In this qualitative study the researcher identified symptoms women experienced
prior to and during an acute myocardial infarction (AMI). The purposive
nonprobability sample for this descriptive naturalistic study consisted of 40
women. Using content analysis and constant comparison, the researcher identified
specific symptoms and grouped them according to time of occurrence, prodromal and
acute. Thirty-seven women experienced prodromal symptoms, beginning from a few
weeks to 2 years prior to their AMI and ranging from 0 to 11 symptoms per woman.
The most frequent prodromal symptoms were unusual fatigue (n = 27), discomfort in
the shoulder blade area (n = 21), and chest sensations (n = 20), whereas the most
frequent acute symptoms were chest sensations (n = 26), shortness of breath (n =
22), feeling hot and flushed (n = 21), and unusual fatigue (n = 18). Only 11
women experienced severe pain during their AMI. Conclusions of this study are
threefold: (a) women identified classic and unique symptoms of AMI, which
challenge the content of current educational literature; (b) women experienced a
gradual progression of number and severity of AMI symptoms; and (c) women need
sufficient time to recognize their prodromal symptoms of their AMI.
PMID- 10782873
TI - Expert decision making in relation to unanticipated blood glucose levels.
AB - How people (N = 22) with long-standing Type I diabetes make everyday self-care
decisions, specifically in regard to unanticipated blood glucose levels (UBGLs)
was investigated using grounded theory. Participants differentiated between
decisions made in familiar and typical situations and those made in novel
situations. Decisions made in familiar situations were straightforward, arising
from a confident appraisal of the cause of the UBGL. The primary focus of
decision making in response to an UBGL in familiar situations was the decision
about the course of action. The focus in unfamiliar situations was the appraisal
of the cause of the UBGL. It was characterized by the participants' lack of
confidence and by a non-linear progression in which the individual retraced
previous phases of the decision-making process or proceeded to tangential steps.
Participants matched the features of previously encountered situations to
construct a story that explained the events in order to generate some plausible
hypotheses. A number of contextual and mediating variables were identified as
influencing the decision-making process and the decisions they made. The findings
of this research demonstrate that the decision maker's familiarity with the
situation influences the nature of the decision-making processes that are used.
PMID- 10782874
TI - Description of retained abilities in older persons with dementia.
AB - There have been suggestions in the literature that the care of people with
dementia must be focused on abilities as opposed to disabilities. However, this
approach has not been carefully defined in terms of what constitutes remaining
abilities. This article provides a description of the abilities in people with
dementia, which is based on a descriptive analysis of data derived from a larger
study regarding the psychometric evaluation of an abilities assessment
instrument. The sample comprised 112 male veterans with dementia who were living
in a long-term care facility. Their mean age was 75 years. Data were collected in
the areas of self-care, social, interactional, and interpretive abilities.
Abilities were retained in all four areas. Furthermore, abilities were
differently affected and varied considerably across subjects, which is consistent
with evidence pertaining to cognitive changes in dementia. Our results provide
support for an individualized, abilities-focused approach to the care of people
with dementia.
PMID- 10782875
TI - An evaluation of a self-generated identification code.
AB - We describe a self-generated coding form used in a study of HIV prevention
practices of college students and provide information on the success rate of
matching questionnaires over a 3-year period using the form. The data for this
study were from a longitudinal study of HIV risk-reduction practices of college
students. In order to match questionnaires over the 3-year study period while
maintaining anonymity, participants were asked to complete a self-generated
identification form at each data collection point. In the second year of the
project, we were able to successfully match 74.3% of the questionnaires to those
returned during the first year using 6 to 8 of the code elements on the form, and
in the third year, we were able to match 73% of questionnaires to those returned
in the second year. Participants for whom questionnaires matched were more likely
than participants with unmatched questionnaires to be white students enrolled as
underclassmen.
PMID- 10782876
TI - Re: Research utilization.
PMID- 10782877
TI - Human herpes virus 8: a new virus discloses its face.
AB - The human herpes virus 8 (HHV8) or Kaposi's sarcoma-associated herpes virus
(KSHV) is present in all Kaposi's sarcoma, and the detection of the virus using
polymerase chain reaction or in situ hybridization is a highly sensitive and
specific diagnostic test for the diagnosis of this neoplasm. HHV8 is furthermore
invariably present in primary effusion lymphoma (PEL) and has also been detected
in patients with acquired immunodeficiency syndrome (AIDS)-associated
multicentric Castleman's disease (MCD) as well as, to a lesser extent, in non
AIDS MCD. In contrast to Kaposi's sarcoma, in which the tumor cells show
primarily latent HHV8 infection, a higher rate of lytically infected cells can be
observed in MCD. Epidemiological surveys indicate that the seroprevalence for
HHV8 parallels the risk of developing Kaposi's sarcoma--5-10% in the general
population of the Western world but ranging up to 20-70% in homosexual human
immunodeficiency virus (HIV)-infected patients, and the infection precedes the
development of Kaposis's sarcoma. Finally, HHV8 has been reported in a number of
other diseases, especially in multiple myeloma. However, the highly controversial
role of HHV8 in these lesions has to be clarified. Based on the data available
today, HHV8 can be assigned as a new human virus, associated with tumors.
PMID- 10782878
TI - Altered intercellular glycoconjugates and dilated intercellular spaces of
esophageal epithelium in reflux disease.
AB - BACKGROUND AND AIMS: The usefulness of histological diagnosis of gastroesophageal
reflux disease (GERD) is limited by poor specificity or sensitivity of available
diagnostic tools. Recently, ultrastructural morphometry showed interstitial space
dilation (ISD) to be a reliable sign of reflux disease. Aims of this study were
to (a) search for a light microscopy equivalent of ISD, (b) test its diagnostic
value, and (c) look for a possible role of intercellular glycoconjugates in its
genesis. METHODS: Esophageal grasp biopsies were taken during endoscopy, 2-3 cm
and 6-7 cm above the squamocolumnar junction, from patients under investigation
for GERD symptoms. The biopsies were fixed in aldehyde solutions and embedded in
resin for electron microscopy or in paraffin for routine histology, and the
glycoconjugates underwent immunohistochemistry using 3-fucosyl-N-acetylactosamine
antibodies. RESULTS: Irregular intercellular space dilation was detected in the
basal and prickle layers using both light and electron microscopy. Hematoxylin
eosin preparations showed ISD in 20 of 22 (90%) erosive esophagitis cases, 30 of
44 (68%) endoscopy negative GERD cases, and 1 of 12 (8%) controls, with good
interobserver (K = 0.75) and bioptic site reproducibility. ISD correlated with
loss or rearrangement of intercellular glycoconjugates of the overlying layers
and with granulocyte (eosinophil and/or neutrophil) infiltration. CONCLUSIONS:
Light microscopy ISD is a suitable index of GERD. Alterations of intercellular
glycoconjugates are likely to have a role in the genesis of ISD and GERD.
PMID- 10782879
TI - Vesicular monoamine transporter 2 as a marker of gastric enterochromaffin-like
cell tumors.
AB - The vesicular monoamine transporter 2 (VMAT2) facilitates the ATP-dependent
accumulation of biogenic amine inside the secretory granules of endocrine cells
and neurons and was demonstrated in the histamine-producing enterochromaffin-like
(ECL) cells of the stomach. In the present investigation, VMAT2
immunohistochemistry was tested in 85 endocrine tumors, of which 60 were well
differentiated gastrointestinal and pancreatic growths, 5 poorly differentiated
(neuro)endocrine carcinomas (PDEC) and 1 mixed PDEC/ECL cell carcinoma of the
stomach, 12 pheochromocytomas/paragangliomas, 3 adrenocortical lesions, 2
parathyroid and 2 lung neuroendocrine tumors. Extensive and intense VMAT2
immunoreactivity was observed in 16 of 16 gastric ECL cell tumors, 6 of 6 adrenal
pheochromocytomas, 2 of 2 chromaffin paragangliomas and in 3 of the 4 carotid
body paragangliomas investigated. Rare VMAT2-positive cells were observed in 12
of 21 intestinal enterochromaffin (EC) cell tumors, in 9 of 11 pancreatic
neuroendocrine tumors, and in the mixed PDEC/ ECL cell carcinoma of the stomach
(differentiated cells only). No VMAT2 immunoreactivity was observed in five
gastrin, four somatostatin and three enteroglucagon/peptideYY tumors of the
gastrointestinal tract, in six gastric PDECs, in three adrenocortical growths,
and two parathyroid and two lung neuroendocrine tumors. These data support VMAT2
immunohistochemistry as being a useful tool for the diagnosis of gastric ECL cell
tumors, separating them from all other endocrine tumors arising in the
gastroduodenal area i.e., gastrin, somatostatin, EC cell and PDEC tumors, all of
which proved essentially negative.
PMID- 10782880
TI - Protein expression of p53, p21 (WAF1/CIP1), bcl-2, Bax, cyclin D1 and pRb in
human colon carcinomas.
AB - Tumour growth is regulated by a balance between proliferation, growth arrest and
programmed cell death (apoptosis). Until recently, the majority of the studies
dealing with oncogenesis has been focused on the regulation of cell
proliferation. There is now growing understanding that control of growth arrest
and apoptosis play key roles in the development of human cancer and in cancer
treatment. Some of the more heavily studied proteins of importance for the
control of growth arrest and apoptosis are p53, p21, bcl-2 and bax. Alterations
in the p53 protein may lead to malignant transformation and defect therapy
response, most likely as a result of defective p53-dependent apoptosis. In
addition, p21 (WAF1/CIP1) is involved in cell-cycle arrest and probably in
induction of p53-dependent apoptosis. Proteins belonging to the bcl-2 family are
also important for normal apoptosis. Overexpression of bcl-2 protein is thought
to reduce the apoptotic capacity, while bax protein seems to be necessary for
induction of apoptosis. In this study, we have immunostained tissues from 93
primary colon carcinomas and have examined the expression of p53, p21
(WAF1/CIP1), bcl-2 bax, pRb and cyclin D1 for evaluation of their roles in colon
cancer progression. A highly significant association between p53 accumulation and
downregulation of p21 (WAF1/CIP1) was seen. We also found a strong association
between reduced/absent p21 and the development of metastases and death due to
cancer disease. Cyclin D1, bcl-2 and bax protein failed to have independent
prognostic impacts. Bcl-2 and bax protein levels showed an inverse relationship.
The results of the present study indicate that reduced p21 protein levels play an
important role in progression of colon cancer. We concluded that evaluation of
p21 expression in primary colon carcinomas at the time of surgery might be a
valuable tool in defining patients with a high risk of developing metastases.
PMID- 10782881
TI - Anal cancer subtype reproducibility study.
AB - For histological subtyping of anal squamous carcinomas the WHO advocates a six
way subdivision, but it has been suspected that the six types cannot be reliably
discriminated in practice. We conducted a blinded study involving slides from 103
consecutive cases, each slide being examined by three experts (from Denmark,
Australia and UK) on two occasions at least 8 months apart. Agreement on subtypes
was low: 72% between rounds within pathologist, 61% between pathologists. Even
for the commonest, and most stably diagnosed, type, viz. large-cell keratinising
squamous carcinoma, the intra- and interpathologist frequencies of confirmation
were only 81% and 71%, respectively. The pathologist marked the picture as
typical and his subtype diagnosis as certain 41% of times: even then confirmation
frequencies were only 88% and 74%, respectively. Calculations, including kappa
analyses, suggest that 26% of the typing variation was noise. The WHO scheme must
be even more unreliable in everyday practice. We finally mention a recently
demonstrated link between human papilloma virus (HPV) and certain types of anal
cancer, which may well provide an additional argument for revising existing
subtyping schemes.
PMID- 10782882
TI - Gastrointestinal pacemaker cell tumor: clinicopathological, immunohistochemical,
and ultrastructural study with special reference to c-kit receptor antibody.
AB - Recent studies indicate that a subgroup of gastrointestinal stromal tumors,
including gastrointestinal autonomic nerve tumors (GANTs), originate from stem
cells that differentiate toward a pacemaker-cell phenotype. These pacemaker cells
form a complex network intercalated between the autonomic nerves and the muscle
walls of the gastrointestinal tract and are called interstitial cells of Cajal
(ICC). The c-kit receptor (CD117) is a sensitive marker for ICC. The aim of our
study was to support the hypothesis that GANTs show ICC differentiation. Seven
GANTs without convincing smooth muscle or neural differentiation all showed
homogeneous reactivity for the c-kit receptor. CD34 was positive in three cases.
On electron microscopy, the typical features of GANT were present. Six tumors
contained skeinoid fibers. Most tumors were related to the small bowel. They
presented as single (two cases) or multiple (five cases) tumors. The presenting
symptoms were abdominal bleeding (2), abdominal mass (2), anemia (1), and small
bowel perforation (1). In two cases, liver metastases developed. Because of the
close immunohistochemical and electron microscopic similarities of these tumors
to the interstitial cells of Cajal, the term gastrointestinal pacemaker cell
tumor seems appropriate.
PMID- 10782883
TI - Association of vascular endothelial growth factor and mast cells with
angiogenesis in laryngeal squamous cell carcinoma.
AB - We investigated the expression of vascular endothelial growth factor (VEGF) and
microvascular density in 54 cases of invasive laryngeal squamous cell carcinoma
(SCC) and in ten samples of normal laryngeal tissue using immunohistochemistry
methods. The study also focused on the distribution of mast cells in and around
the SCCs. The microvascular density in laryngeal carcinoma tissue was higher than
that in normal tissue (P = 0.02). VEGF was localized in SCCs, stromal cells,
endothelial cells, minor salivary glands, and non-cancer epithelium adjacent to
the tumor. VEGF expression in the tumor cells was found in 13 of 54 cases
(24.1%), whereas mast cells around the carcinomas were VEGF positive in all 54
cases. Staining of VEGF in SCCs was strong in the area of high microvascular
density (P = 0.0002). Using a multi-labeling subtraction immunostaining method,
VEGF-positive stromal cells were classified mostly as mast cells and, in a few
instances, as macrophages. VEGF staining in SCCs was associated with the mast
cell count (P = 0.0001). There was no distinct correlation between VEGF
expression and pTNM stage of an SCC. In conclusion, the results suggest that VEGF
might be an important angiogenic factor in cancer invasion. Laryngeal cancer
cells and mast cells may control the angiogenic response by releasing VEGF.
PMID- 10782884
TI - Light and electron microscopic examination of endothelial cells from bovine
retinal vessels in long-term cultures.
AB - The aim of the present work was to examine and compare the ultrastructure of
bovine retinal endothelial cells (BRECs) in vitro during several passages in a
medium selective for endothelial cells. The identity of the endothelial cells was
confirmed immunohistochemically, up to the tenth passage. Changes in their
ultrastructure in comparison to endothelial cells in vivo occurred at the onset
of culturing and not progressively with repeated passages. The cultured BRECs
show high metabolic activity in all passages. While retaining their identity as
endothelial cells, they modify their lipid metabolism, so that lipids are stored.
This change in lipid metabolism was induced by the medium.
PMID- 10782885
TI - Ultrastructure and molecular histology of rabbit hind-limb collateral artery
growth (arteriogenesis).
AB - Previous studies in the canine heart had shown that the growth of collateral
arteries occurs via proliferative enlargement of pre-existing arteriolar
connections (arteriogenesis). In the present study, we investigated the
ultrastructure and molecular histology of growing and remodeling collateral
arteries that develop after femoral artery occlusion in rabbits as a function of
time from 2 h to 240 days after occlusion. Pre-existent arteriolar collaterals
had a diameter of about 50 microm. They consisted of one to two layers of smooth
muscle cells (SMCs) and were morphologically indistinguishable from normal
arterioles. The stages of arteriogenesis consisted of arteriolar thinning,
followed by transformation of SMCs from the contractile- into the proliferative-
and synthetic phenotype. Endothelial cells (ECs) and SMCs proliferated, and SMCs
migrated and formed a neo-intima. Intercellular adhesion molecule (ICAM-1) and
vascular cell adhesion molecule (VCAM-1) showed early upregulation in ECs, which
was accompanied by accumulation of blood-derived macrophages. Mitosis of ECs and
SMCs started about 24 h after occlusion, whereas adhesion molecule expression and
monocyte adhesion occurred as early as 12 h after occlusion, suggesting a role of
monocytes in vascular cell proliferation. Treatment of rabbits with the pro
inflammatory cytokine MCP-1 increased monocyte adhesion and accelerated vascular
remodeling. In vitro shear-stress experiments in cultured ECs revealed an
increased phosphorylation of the focal contacts after 30 min and induction of
ICAM-1 and VCAM-1 expression between 2 h and 6 h after shear onset, suggesting
that shear stress may be the initiating event. We conclude that the process of
arteriogenesis, which leads to the positive remodeling of an arteriole into an
artery up to 12 times its original size, can be modified by modulators of
inflammation.
PMID- 10782886
TI - Feasibility of simultaneous fluorescence immunophenotyping and fluorescence in
situ hybridization study for the detection of estrogen receptor expression and
deletions of the estrogen receptor gene in breast carcinoma cell lines.
AB - For the first time, combined immunophenotyping and fluorescence in situ
hybridization (FISH) technique according to the "fluorescence immunophenotyping
and interphase cytogenetics as a tool for investigation of neoplasms" (FICTION)
technique have been successfully applied in solid tumors. Thus, we were able to
visualize the antigen expression of cells with chromosomal deletions of a tumor
suppressor region directly. In six breast carcinoma cell lines, we investigated
the correlation between estrogen receptor (ER) expression status and deletions of
the estrogen receptor gene (ESR). To screen for deletions of the ESR gene, dual
color FISH was performed with a YAC (yeast artificial chromosome) probe
containing the ESR gene and, as internal control, with a centromeric probe of
chromosome 6. Deletions of the ESR gene were detected in four of six cell lines.
For direct comparison of ER expression with the copy number of the ESR gene at
the single cell level, immunophenotyping with mouse anti-human ER antibody was
combined with FISH with the YAC probe containing the ESR gene according to the
FICTION technique. There was no correlation between lack of or reduced ER
expression and deletions of the ESR gene. One cell line with deletions of the ESR
gene did express ER on the protein level, while another cell line without a
deletion did not. Cells with deletions of the ESR gene were either ER expression
positive or negative. The staining intensity of ER expression was not associated
with the copy number of the ESR gene. Thus, this FICTION study unequivocally
shows that deletions of the ESR gene are not the major cause of absent or reduced
ER expression in breast carcinoma cell lines.
PMID- 10782887
TI - Testicular diffuse large cell lymphoma with tubule preservation--molecular
genetic evidence of transformation from previous follicular lymphoma.
AB - Testicular lymphomas usually occur in older men and are mostly diffuse large B
cell lymphomas (DLBL). They may be primary manifestation of lymphoma or represent
a relapse of a previous non-Hodgkin's lymphoma. This report details a testicular
large cell lymphoma, which was proven to be large cell transformation of a low
grade follicular lymphoma biopsied 8 years earlier. Initially, a 38-year old man
was diagnosed with cervical lymphadenopathy, and biopsy was interpreted as
reactive follicular hyperplasia; no treatment was given, and the lymphadenopathy
resolved spontaneously. Eight years later, the patient underwent surgery for a
left testicular mass and gastroscopy for gastric symptoms. The patient died 7
months later with evidence for intra-abdominal and central nervous system
lymphoma after a brief but temporary response to M-BACOD chemotherapy.
Orchiectomy specimen and gastroscopic biopsy showed diffuse large B-cell lymphoma
(CD20+), which infiltrated between well-preserved tubules in the testis.
Histological comparison with 20 testicular lymphomas without previous lymphoma
showed tubule infiltration in all cases, suggesting that the tubule-preserving
infiltration pattern could be a histological marker for secondary lymphoma
involvement in testis. On re-examination, the lymph node 8 years prior was
verified as follicular, predominantly small, cleaved cell lymphoma with bcl2
positive follicles. The earlier follicular lymphoma and the subsequent diffuse
large cell lymphoma were analyzed using polymerase chain reaction and showed
identical sequences of the t(14;18) translocation and immunoglobulin heavy chain
gene rearrangement. Analysis of the VH-gene sequences from the follicular
lymphoma revealed sequence heterogeneity consistent with ongoing mutation.
However, the transformed diffuse large cell lymphoma had no intraclonal
variation, with the sequence matching with one of the subclones from the low
grade follicular lymphoma. These results confirm that the large cell
transformation of follicular lymphoma occurs in a single follicular lymphoma
cell. This case also indicates that the selection of the transformed clone can be
part of the natural history of disease and can occur without exposure to
chemotherapy.
PMID- 10782888
TI - Progesterone receptor expression in orbital cavernous hemangiomas.
AB - Orbital cavernous hemangiomas (OCH) have thick and highly cellular vascular
walls. Ultrastructural studies have demonstrated the smooth muscle nature of
these cells. Vascular neoplasms can modify their morphological and clinical
features under hormonal stimulation. The purpose of the present study was to
investigate the presence of smooth muscle markers and sex steroid receptors in 12
cases of OCH. Orbital cases were compared with cutaneous hemangiomas and
subcutaneous angioleiomyomas. Smooth muscle actin (SMA) and desmin were localized
in spindle cells of the vascular walls of all 12 cases studied. OCH showed
immunohistochemical positivity with progesterone receptor (PR) antibody both in
smooth muscular and in endothelial cells. For comparison, sex steroid receptors
were studied in 10 cases of cutaneous cavernous hemangioma and in 10 cases of
subcutaneous angioleiomyoma. PR was found in smooth muscle and endothelial cells
of 6 out of 10 cases of subcutaneous angioleiomyoma and in none of the cases of
cutaneous cavernous hemangioma. No positivity was obtained with estrogen receptor
(ER) antibody in any of the cases tested. The present data suggest that OCH share
morphological and immunohistochemical features with subcutaneous angioleiomyomas.
Furthermore, immunohistochemical positivity with PR antibody indicates that OCH
have to be added to the list of mesenchymal lesions that express sex steroid
receptors.
PMID- 10782889
TI - Peripheral papillary tumor of type-II pneumocytes: a rare neoplasm of
undetermined malignant potential.
AB - Peripheral papillary adenomas of the lung are uncommon neoplasms (only ten cases
have been described so far in the English literature) composed predominantly of
type-II pneumocytes and generally considered benign. We describe here two
additional cases of this lung tumor. In both cases histological examination
revealed an encapsulated papillary neoplasm with invasion of the capsule and, in
one case, invasion of the adjacent alveoli and visceral pleura too. The
proliferative index (Ki67) was less than 2% and the epithelial cells were
positive for cytokeratins, surfactant apoproteins (SP), and nuclear thyroid
transcription factor-1 (TTF- 1). Ultrastructurally, the epithelial cells showed
the characteristic surface microvilli and cytoplasmic lamellar inclusions of type
II cells. Review of the literature has revealed two other cases of peripheral
papillary adenoma of type-II pneumocytes with infiltrative features. Thus, we
propose replacing the term peripheral papillary adenoma with peripheral papillary
tumor of undetermined malignant potential.
PMID- 10782890
TI - Defective DNA repair genes in a primary culture of human renal cell carcinoma.
AB - PURPOSE: Genomic stability is maintained by error-free DNA replication, repair,
and recombination. To determine if repair genes contribute to genomic
instability, we used a newly established cell line RCC-AJR (from clear-cell renal
cell carcinoma) to examine hMSH2 (a mismatch-repair gene) and the gene encoding
DNA beta polymerase (polbeta; a known contributor to base-excision repair).
METHODS: Coding sequences of hMSH2 and polbeta were amplified by the polymerase
chain reaction (PCR) using RNA from RCC-AJR cells and matched normal kidney (NK)
cells from the same patient. Nucleotide sequences of the PCR products were
determined by the dideoxy-DNA method and direct sequencing. Expressions of repair
genes were assayed by Western blotting. Microsatellite stability in RCC-AJR cells
was assayed by alteration in (CA)n repeats. RESULTS: In the RCC-AJR cells, we
detected (a) a deletion of 1476 bp encoding 492 amino acids of hMSH2 cDNA, (b) an
87-bp deletion in the polbeta coding sequence, (c) truncated forms of hMSH2 and
polbeta proteins, and (d) microsatellite instability. CONCLUSIONS: This study
provides evidence of alterations in hMSH2 and polbeta in the homogeneous cell
population of an RCC-AJR tumor culture. The data indicate that repair genes may
help preserve genomic stability in this cell line. We believe that this new
primary RCC-AJR cell line will prove a useful model for investigating the cascade
of genetic events in renal cells that leads to renal carcinogenesis.
PMID- 10782891
TI - Cycloprodigiosin hydrochloride, a H+/Cl- symporter, induces apoptosis in human
breast cancer cell lines.
AB - The effect of cycloprodigiosin hydrochloride (cPrG.HCl), a H+/Cl- symporter, on
five human breast cancer cell lines (KPL-1, T-47D, MCF-7, MKL-F, and MDA-MB-231),
a human breast epithelial cell line (HBL-100), and a human fibroblast cell line
(WI-38-40) was examined. cPrG.HCl inhibited the growth of all five breast cancer
cell lines (IC50: 0.46-0.62 microM) and slightly inhibited HBL-100 and WI-38-40
cell growth (IC50: 1.75 microM and 2.26 microM respectively). cPrG.HCl treatment
in KPL-1 cells increased the pH of acidic organelles, decreased intracellular pH,
and caused apoptosis, which was confirmed by the appearance of a sub-G1
population by flow cytometry and DNA fragmentation. In addition, cPrG.HCl-induced
apoptosis was strongly suppressed by imidazole, a cell-permeable base, suggesting
that intracellular acidification was essential for the apoptosis. Further,
cPrG.HCl treatment up-regulated Bax and Bak expression, down-regulated Bcl-2
expression, and activated caspase-3. Therefore, the intracellular acidification
by cPrG.HCl treatment suppressed the growth of human breast cancer cell lines by
inducing apoptosis.
PMID- 10782892
TI - Differential modulation of chemosensitivity to alkylating agents and platinum
compounds by DNA repair modulators in human lung cancer cell lines.
AB - PURPOSE: Modulation of DNA repair represents one strategy to overcome cellular
drug resistance to alkylating agents and platinum compounds. The effects of
different known DNA repair modulators such as O6-benzylguanine (6 microg/ml),
fludarabine (25 ng/ml), aphidicolin (8.5 ng/ml), pentoxifylline (1.4 microg/ml)
and methoxamine (12.4 microg/ml) on the cytotoxicity of mafosfamide,
chlorambucil, 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU), cisplatin and
carboplatin were tested in human lung cancer cell lines. METHODS:
Chemosensitivity of the human adenocarcinoma cell line MOR/P and the cisplatin
resistant subline MOR/CPR as well as the large-cell lung cancer cell line L23/P
and its cisplatin-resistant counterpart L23/CPR were evaluated by the MTT
colorimetric assay. RESULTS: O6-benzylguanine, an inhibitor of O6-alkylguanine
DNA alkyltransferase, significantly sensitised MOR/P and MOR/CPR cells to the
cytotoxic effect of BCNU. Fludarabine, methoxamine and aphidicolin did not change
the chemosensitivity of the parental and cisplatin-resistant cell lines to any
cytotoxic drug tested. Interestingly, O6-benzylguanine enhanced the
chemoresistance of parental and cisplatin-resistant cell lines to platinum
compounds. Also, pentoxifylline increased resistance of the MOR cell lines to
mafosfamide. CONCLUSIONS: Modulation of DNA repair elicits not only
chemosensitisation but may also enhance cellular resistance to DNA-affine drugs.
PMID- 10782893
TI - Expression of erbB-3 protein in colorectal adenocarcinoma: correlation with poor
survival.
AB - BACKGROUND/AIMS: The family of erbB receptors includes four transmembrane
glycoproteins with tyrosine kinase activity. These receptors are widely expressed
in normal tissues, but they also have been implicated in the development of
several human adenocarcinomas. c-erbB-3/HER-3 has been detected to a greater or
lesser extent in many tissues from the digestive, urinary, reproductive and
respiratory tracts. The overexpression of c-erbB-3/HER-3 protein has also been
shown in 53%-88% of colorectal adenocarcinomas. In this study we investigated the
expression of the c-erbB-3/ HER-3 gene product in colorectal tumour samples, and
compared the results obtained with several clinicopathological parameters,
including the survival of patients. METHODS: Paraffin-embedded tissue sections
were analysed immunohistochemically, using monoclonal antibody RTJ1 to human erbB
3 protein. Antibody RTJ1 specificity was confirmed by immunoprecipitation
followed by Western blotting analysis. Amplification of the erbB-3 oncogene was
tested by dot-blot hybridization. RESULTS: Adenocarcinomas of the colon were
positive for erbB-3 protein in 78% of samples examined. Dot-blot analysis showed
no amplification of the erbB-3 gene in colon adenocarcinomas. Statistical
analysis showed that patients with tumours that could not be stained for erbB-3
protein survived significantly longer (P<0.05) than patients with tumours
staining positive for the erbB-3 protein. A Cox proportional-hazards model with
stepwise variable selection identified age, sex and erbB-3 expression as
important prognostic factors. CONCLUSION: These findings demonstrate that erbB-3
protein expression could serve as a prognostic factor in colorectal malignancies.
PMID- 10782894
TI - Sensitive detection of micrometastases in bone marrow from patients with breast
cancer using immunomagnetic isolation of tumor cells in combination with reverse
transcriptase/polymerase chain reaction for cytokeratin-19.
AB - We report a highly sensitive method to detect rare human breast cancer cells,
which combines an immunomagnetic separation (IMS) using antibody BM2 against MUC
1 with cytokeratin-19 (CK19) and the reverse transcriptase/polymerase chain
reaction (RT-PCR). The IMS-RT-PCR technique allows the detection of 1 tumor
cell/10(7)-10(8) mononuclear cells. This is at least ten times more sensitive
than CK19 RT-PCR alone, or immunocytochemistry. All 117 peripheral blood and 8
bone marrow samples obtained from healthy donors as negative controls were
positive for beta2-microglobulin by RT-PCR but negative for CK19 by IMS-RT-PCR or
RT-PCR alone. Out of 26 bone marrow samples from breast cancer patients, 18 had
CK19 transcripts detectable by IMS-RT-PCR. In contrast, only 14 and 13 samples
from the 26 were found to be positive by RT-PCR alone or by routine
immunocytochemical staining. In conclusion, IMS-RT-PCR for CK19 is a highly
sensitive and specific method for detecting very low numbers of micrometastatic
breast cancer cells in bone marrow amidst an excess of nonmalignant cells. For
the early diagnosis of disseminating disease, this assay is more efficient than
RT-PCR alone and routine immunocytochemistry.
PMID- 10782895
TI - Patterns of expression and secretion of vascular endothelial growth factor in
malignant soft-tissue tumours.
AB - Vascular endothelial growth factor (VEGF) is an important cytokine especially in
the process of tumour angiogenesis. A total of 46 soft-tissue sarcomas were
analysed for the expression and possible secretion of VEGF by
immunohistochemistry, in-situ hybridisation, and enzyme-linked immunosorbent
assays (ELISA). VEGF was demonstrated immunohistochemically in tumour tissue in
45 of 46 cases. The detection of mRNA transcripts yielded evidence of synthesis
of VEGF in these sarcomas. ELISA could be performed in 21 cases. Higher
concentrations of VEGF were found in tumour-related intraoperatively sampled
venous blood in 16 out of 21 patients (76%) than in systemic concentrations taken
preoperatively. The results indicated the secretion of VEGF by tumour cells
although these raised concentrations were not statistically significant. In 12
out of these 16 patients (75%) a concurrent moderate to strong immunoexpression
of VEGF was detected. The relevance of VEGF blood concentrations as a potential
"progress parameter" for the course of disease remains questionable. This is
mainly due to the lack of statistical significance in the difference between
systemic VEGF concentrations in patients and those of a control group. Further
long-term follow-up studies are needed, which should include patients with tumour
recurrences.
PMID- 10782896
TI - Wilms' tumor gene (WT1) expression in lung cancer, colon cancer and glioblastoma
cell lines compared to freshly isolated tumor specimens.
AB - The Wilms' tumor gene (WT1) encodes a transcriptional regulator involved in
growth and differentiation of various tissue types. A continuous over-expression
of WT1 was found in leukemic blasts, thus suggesting an oncogenic function. Solid
cancer entities have also been described as expressing WT1. We systematically
analyzed WT1 expression in small-cell and non-small-cell lung cancer, colon
cancer and glioblastoma patients and in the respective tumor cell lines. Using
reverse transcription/polymerase chain reaction, we found WT1 expression in
glioblastoma (5 of 8), lung (5 of 11), and colon cancer (5 of 15) cell lines.
While WT1 was expressed in only 1 of 12 lung cancer and 1 of 5 glioblastoma
specimens, it was not detected in colon cancer or macroscopically tumor-free
colon and lung tissue. In addition, HT29 colon cancer cells showed a loss of WT1
expression when grown to confluence or induced to differentiate by sodium
butyrate. From this evidence, testing for WT1 expression is not clinically
relevant for colon cancer, lung cancer, or glioblastoma patients. WT1 expression
in cancer cell lines can probably be attributed to optimized in vitro growth
conditions.
PMID- 10782897
TI - Gastric cancer in very young adults: apropos four patients and a review of the
literature.
AB - Whether gastric cancer in young adults differs from gastric cancer in older
patients has been a controversial issue. It has long been suspected that young
patients with gastric cancer have different biological features with a more
aggressive course of disease and a poorer prognosis than older patients. This,
however, has not been firmly substantiated. We report on the clinical course of
four patients (three female and one male) with locally advanced (n = 1) or
metastasized (n = 3) non-resectable gastric cancer diagnosed under the age of 29
years (23, 25, 27, 28 years). Prior to diagnosis, all three women had recently
been pregnant (1-22 months). Diagnosis was endoscopically biopsy-proven and
staging work-up was performed by primary explorative surgery (n = 1), laparoscopy
and explorative surgery (n = 1) or CAT scan and ultrasound (n = 2). The delay
between initial symptoms and diagnosis was 8-22 weeks (median, 10 weeks). The
histology was signet-ring cell (n = 2) or undifferentiated (n = 2) gastric
cancer. All patients had the diffuse type of gastric cancer according to Lauren.
Patients were treated with the FLAP polychemotherapy regimen consisting of
leucovorin, 5-fluorouracil, doxorubicin and cisplatinum, as previously reported.
The best response after chemotherapy was partial in two patients. Two patients
showed progressive disease. Secondary surgery was performed in three responding
patients (one of them responded only locally). One patient achieved no evidence
of disease after complete tumor resection (R0). In two patients surgery was
palliative (R2/exploration). Three patients died 6, 4 and 8 months after
diagnosis. One patient is still alive. In our series, very young adults with
gastric cancer had adverse clinical and pathological features. In accordance with
other reports, we observed a predominance of female patients and a possible
association with recent pregnancies. Though the delay between the first symptoms
and diagnosis in our patients was no different from that reported for older
patients, special emphasis should be given to prompt referral and diagnostic
investigations, ensuring the diagnosis of gastric cancer early in the course of
disease.
PMID- 10782898
TI - p53 tumour-suppressor gene in non-small-cell lung cancer with neoadjuvant
therapy.
AB - In a phase II study for optimizing therapeutic management of locally advanced non
small-cell lung cancer the prognostic and therapeutic relevance of the p53 status
was investigated. Biopsy or mediastinoscopy samples, collected prior to
neoadjuvant chemoradiotherapy and corresponding resection specimens, were
analysed immunohistochemically (CM1 antiserum) for p53 accumulation and molecular
biologically (polymerase chain reaction/single-strand conformation polymorphism)
for p53 mutations. The results were correlated to the response to therapy
(regression grade) and to the survival times. p53 accumulation was found in 41.7%
(prior to neoadjuvant therapy) and in 40.0% (after surgery) of the tumours. p53
mutation was demonstrated in 45.4% (prior to neoadjuvant therapy) and in 46.4%
(after surgery) of the investigated tumours. Neither before nor after therapy was
any correlation to the survival times or to the response to therapy seen in the
collective analysed. Thus, such investigations are not suitable for identifying
patients with locally advanced non-small-cell lung cancer who might benefit, to
different extents, from neoadjuvant therapy.
PMID- 10782899
TI - Evidence of carcinogenicity of DDT in nonhuman primates.
PMID- 10782900
TI - CTLA-4 gene polymorphism confers susceptibility to primary biliary cirrhosis.
AB - BACKGROUND/AIM: Primary biliary cirrhosis (PBC) is an autoimmune cholestatic
liver disease thought to develop through a complex interaction of genetic and
environmental factors. It is characterised by T-cell-mediated non-suppurative
destructive cholangitis. We have studied the polymorphic cytotoxic T lymphocyte
associated antigen-4 (CTLA-4) gene, which encodes a molecule that is a vital
negative regulator of T-cell activation, as a candidate susceptibility locus for
PBC. This gene on chromosome 2q33 (designated IDDM12) is associated with
susceptibility to both type 1 diabetes and autoimmune thyroid disease. METHODS:
The CTLA-4 exon 1 polymorphism (A/G encoding for threonine or alanine,
respectively) was genotyped via polymerase chain reaction in 200 Caucasoid PBC
patients and 200 non-related geographically matched Caucasoid controls. RESULTS:
There was significant overrepresentation of the G/A and G/G genotypes in PBC
patients compared to controls (G/A 53% vs 40%; G/G 18.5% vs 10.5%, Odds Ratio
(OR)=2.45 [95% CI 1.6-3.7], p=0.00006, chi2=19.4). Likewise, there was a
significant difference in allele frequencies (G encoding alanine at codon 17, PBC
0.45 vs controls 0.305: OR=1.9 [1.4-2.5], p<0.0002). This association remained
significant (p=0.00027) when patients with autoimmune thyroid disease were
excluded from the analysis. CONCLUSIONS: The CTLA-4 exon 1 polymorphism is the
first non-major histocompatibility complex gene to be identified as a
susceptibility locus for PBC. Our data support the hypothesis that clinically
distinct autoimmune disease may be controlled by a common set of susceptibility
genes.
PMID- 10782902
TI - Role of glutathione and oxidative stress in phalloidin-induced cholestasis.
AB - BACKGROUND/AIMS: Biliary glutathione is an important generator of the bile-salt
independent flow, and is known to be regulated by the hepatic glutathione
availability. We investigated, in an acute model of phalloidin-induced
cholestasis, biliary glutathione secretion and the role of hepatic glutathione,
oxidative stress, and protein kinase c activation, which have been implicated in
many hepatotoxin-induced hepatic dysfunctions. METHODS: Rats were given a single
dose of 80 microg/100 g body weight of phalloidin and the hepatic thiols and
glutathione content, redox state and vesicular activity were evaluated during
both development of and recovery from cholestasis. The prophylactic effect of N
acetylcysteine (a precursor of glutathione synthesis and an antioxidant) was also
examined. In addition, in the isolated perfused rat liver, we studied the
prophylactic effect of the PKc inhibitor H7 on phalloidin-induced cholestasis.
RESULTS: In the early stages of cholestasis, phalloidin induced a decline in bile
flow, mainly related to a disruption of biliary glutathione secretion. The
decline in biliary glutathione content was not associated with increased
glutathione degradation, indicated by a parallel decline in biliary non-protein
thiols and by the lack of an increase in biliary gamma-glutamyltranspeptidase.
There was also no evidence of hepatic depletion of glutathione or of oxidative
stress, as measured by the oxidized-to-reduced glutathione ratio. Moreover,
phalloidin resulted in inhibition of vascular transcytosis as assessed by
horseradish peroxidase labeling. Pre-treatment with N-acetylcysteine did not
counteract the decline in biliary glutathione secretion and bile flow produced by
phalloidin, supporting the view that the hepatic availability of glutathione and
oxidative stress injury are not implicated in the early stages of cholestatic
injury. Moreover, treatment with H-7 did not alter the biliary glutathione
output, or the decline in bile flow induced by the toxin. CONCLUSIONS: This study
suggests that the phalloidin-induced inhibition of bile formation may be
attributed to rapid disruption of the hepatocanalicular transport of glutathione.
PMID- 10782901
TI - Selenium, zinc and copper plasma levels in intrahepatic cholestasis of pregnancy,
in normal pregnancies and in healthy individuals, in Chile.
AB - BACKGROUND/AIMS: Low blood Se levels have been previously shown in normal
pregnancies (third trimester) and significantly lower levels in patients with
intrahepatic cholestasis of pregnancy (ICP), in Finland and in Chile, suggesting
that a low or marginal dietary availability of Se may contribute to the
pathogenesis of this disease. The aim of this study was to investigate whether a
temporal change in plasma concentration of Se, and seasonal fluctuations in
plasma concentrations of Se, Zn and Cu, could coincide with changes in the
prevalence of ICP. METHODS: A cross-sectional cohort study was done including 21
ICP patients, 98 women in the third trimester of a normal pregnancy, 29 non
pregnant women, and also 13 individuals (seven non-pregnant women and six men)
who had been studied 9 years before. Plasma Se, Zn and Cu were measured by atomic
spectroscopy. Plasma Se levels in the present study were compared to the results
obtained 5 to 7 years before, employing identical methodology in similar
population samples. RESULTS: Plasma Se concentrations in non-pregnant women were
higher than in the previous study: 1.43+/-0.34 micromol/l vs 0.85+/-0.13;
p<0.001. In comparison to non-pregnant women, normal pregnancies near term had
lower plasma levels of Se: 1.08+/-0.25 micromol/l; p<0.01, and Zn: 17.90+/-3.61
micromol/l vs 19.71+/-3.21; p<0.05, but higher plasma levels of Cu: 34.35+/-7.12
micromol/l vs 20.62+/-3.34; p<0.01. In normal pregnancies, plasma Se
concentration was significantly higher in summer (1.34+/-0.19 micromol/l) than in
the other seasons, while Zn and Cu diminished. Similar to previous studies, ICP
patients had significantly lower Se plasma levels than normal pregnancies: 0.94+/
0.12 micromol/l, p<0.05, and Cu levels were significantly higher: 50.80+/-7.02
micromol/l, p<0.01. Cu plasma levels correlated with the biochemical severity of
the disease. Zn did not change in ICP. CONCLUSIONS: The present study shows that
the decrease in the prevalence of ICP in Chile during the last decade coincides
with an increase in plasma Se levels. Its lower incidence during summer coincides
with a higher plasma Se concentration in summer than in other seasons, as
observed in normal pregnancies.
PMID- 10782904
TI - Oxygen regulation of rat hepatocyte iNOS gene expression.
AB - BACKGROUND/AIMS: The human iNOS promoter contains a consensus sequence for
binding the hypoxia inducible factor. The aim of this study was to see whether
iNOS gene expression is triggered by oxygen tension in rat hepatocytes exposed in
vivo to high (periportal) and low (perivenous) oxygen tension. METHODS:
Hepatocytes transfected or not with a plasmid containing rat iNOS promoter linked
to chloramphenicol acetyltransferase were cultured at 21% and 5% oxygen tension.
In normal hepatocytes, iNOS protein, mRNA and activity were detected. In
transfected cells, chloramphenicol acetyltransferase activity was measured.
RESULTS: In cells cultured in a hypoxic environment, both iNOS protein and mRNA
increased, whereas the nitrite level in the medium decreased. However, electron
paramagnetic resonance analysis and in vitro iNOS activity indicated that iNOS
was active. Transfection experiments showed that the expression of
chloramphenicol acetyltransferase driven by iNOS promoter was increased in cells
maintained at low oxygen tension. CONCLUSIONS: Our experiments show that in rat
hepatocytes: 1) iNOS is induced by low oxygen tension; 2) the modification occurs
at the transcriptional level; 3) the enzyme at 5% oxygen is able to catalyze the
synthesis of NO, although no nitrites are accumulated in the medium. These
findings could have physiopathological relevance, e.g. in determining the
resistance of perivenous hepatocytes to ischemia injury.
PMID- 10782903
TI - Long-term effects of ursodeoxycholic acid in primary biliary cirrhosis: results
of a double-blind controlled multicentric trial. UDCA-Cooperative Group from the
Spanish Association for the Study of the Liver.
AB - BACKGROUND/AIM: The aim of this study was to assess the efficacy of
ursodeoxycholic acid (UDCA) for primary biliary cirrhosis in a randomized, double
blind placebo-controlled trial. METHODS: Consecutive patients (n=192) were
randomized to receive 14-16 mg UDCA/kg/day or placebo. Patients underwent a
complete history, physical examination, liver chemistries, immunological
determinations and liver biopsy at entry and at the end of the trial, which
lasted for at least 2 years. Patients were seen every 3 months and the median
follow-up was 3.4 years (range 0.3 to 6.1 years). RESULTS: Patients receiving
UDCA (99) or placebo (93) were comparable with regard to age, sex, biochemical
parameters and liver histology. UDCA treatment was associated with decreases in
alkaline phosphatase, gammaglutamyl transferase, alanine aminotransferase, and
cholesterol levels, effects which were conspicuous after 3 months of treatment
and remained similar during the follow-up. During the study 31 patients (10
receiving UDCA and 21 placebo) discontinued the trial because of noncompliance
(n=11), voluntary withdrawal (n=19) or adverse effects (n=1). Treatment failure
(death or liver transplantation) was observed in 17 patients receiving UDCA and
in 11 patients receiving placebo. Times to death or liver transplantation and to
clinical complications were not significantly different in patients receiving
UDCA or placebo. Histological analysis indicates that UDCA improved portal
inflammation and prevented histological stage progression. By contrast,
histological stage as well as ductular proliferation and ductopenia progressed in
patients receiving placebo. CONCLUSIONS: Although UDCA treatment did not
significantly affect time to death or liver transplantation and to clinical
complications, the effects on both cholestasis and liver histology suggest that
UDCA is safe and may be useful for preventing the progression of primary biliary
cirrhosis.
PMID- 10782906
TI - Blood neutrophil functions and cytokine release in severe alcoholic hepatitis:
effect of corticosteroids.
AB - BACKGROUND/AIMS: Several observations point to an important role of interactions
between polymorphonuclear neutrophils and cytokines in severe alcoholic
hepatitis. The polymorphonuclear neutrophil activation status and the local and
systemic pro- and anti-inflammatory cytokine responses were quantified. The
effect of corticosteroids, widely used in this setting, was evaluated using these
parameters. METHODS: We studied blood polymorphonuclear neutrophil functions in
terms of L-selectin and beta2-integrin expression, H2O2 production and IL-8 and
tumor necrosis factor alpha synthesis capacity. We also measured IL-8, tumor
necrosis factor alpha and IL-10 plasma and liver tissue levels. Fifteen patients
with alcoholic hepatitis were compared to 15 patients with alcoholic cirrhosis
without alcoholic hepatitis, and to 10 healthy volunteers. The impact of a 28-day
course of corticosteroids on blood neutrophils activation status and cytokine
levels was evaluated in patients with alcoholic hepatitis. RESULTS: Blood
polymorphonuclear neutrophils were activated, as shown by increased H2O2
production (48+/-6 vs 29+/-6 MFI in healthy controls), and decreased L-selectin
expression (300+/-61 vs 449+/-59 in healthy controls). Upon stimulation,
polymorphonuclear neutrophils synthesized large amounts of IL-8 (21.7+/-9.2 ng/ml
vs 8.8+/-10 ng/ml in healthy controls) and tumor necrosis factor alpha (524+/-132
pg/ml vs 79+/-144 pg/ml in healthy controls). Tumor necrosis factor alpha and IL
8 plasma and tissue levels were markedly increased as IL-10 was barely detectable
in alcoholic hepatitis patients, compared to cirrhotic patients and healthy
controls. During steroid therapy, plasma levels of the pro-inflammatory cytokine
IL-8 fell as early as day 14, while levels of the anti-inflammatory cytokine IL
10 increased on day 21. Finally, polymorphonuclear neutrophil functions returned
to normal after treatment. CONCLUSION: Severe alcoholic hepatitis appears to be
associated with polymorphonuclear neutrophil activation and an imbalance between
pro- and anti-inflammatory cytokines; during steroid therapy a normalization of
these parameters was observed.
PMID- 10782905
TI - Flow cytometric analysis of autonomous growth of erythroid precursors in liquid
culture detects occult polycythemia vera in the Budd-Chiari syndrome.
AB - BACKGROUND/AIMS: Hepatic vein thrombosis (Budd-Chiari syndrome) is associated
with various hypercoagulable states, such as polycythemia vera (PV), presence of
the lupus anticoagulant, paroxysmal nocturnal hemoglobinuria (PNH) and
deficiencies of antithrombin III, protein C and protein S. In recent years, it
has become evident that patients with the Budd-Chiari syndrome may have more than
one risk factor that may cause a state of hypercoagulability. The aim of the
current study was to assess the prevalence of occult PV in patients with Budd
Chiari syndrome using a novel method for the detection of spontaneous erythroid
growth. METHODS: Twenty-two patients with Budd-Chiari syndrome were evaluated. As
controls, we studied normal donors and four patients with liver cirrhosis and
five patients with right-side heart failure, two conditions that in part mimic
Budd-Chiari syndrome. The presence of PV was determined by flow cytometric
analysis of autonomous growth of erythroid precursors. Patients were considered
as having occult PV if they had spontaneous erythroid cell growth in the absence
of erythropoietin and with no features of overt PV. RESULTS: Cells from ten
patients with Budd-Chiari syndrome demonstrated spontaneous erythroid cell
growth; eight patients (32%) were found to have occult PV and two patients had
overt PV. None of the controls had spontaneous erythroid growth. Of the eight
Budd-Chiari patients with occult PV, six had one or more additional recognized
hypercoagulable states. Seven patients (32%) had protein C deficiency, six
patients (27%) had activated protein C resistance, five (23%) had anti
cardiolipin antibodies, five (23%) had antithrombin III deficiency, and four
patients (18%) had protein S deficiency. Three patients (14%) were homozygous to
methyltetra hydrofolate reductase and ten (45.5%) were heterozygous. One patient
had PNH. Overall, in 12 patients there were two or more combined risk factors.
CONCLUSIONS: Using a flow cytometric analysis of autonomous growth of erythroid
precursors we found a clear correlation between Budd-Chiari syndrome and occult
PV.
PMID- 10782907
TI - Suppression of hepatic lesions in a murine graft-versus-host reaction by
antibodies against adhesion molecules.
AB - BACKGROUND/AIMS: The injection of parental CD4+ T cells into major
histocompatibility complex (MHC) class II disparate F1 hybrid mice induced an
autoimmune graft-versus-host reaction (GVHR) which is analogous to autoimmune
liver diseases. The interaction of adhesion molecules such as vascular cell
adhesion molecule-1 (VCAM-1) and very late antigen-4 (VLA-4) has been known to be
profoundly involved in the trafficking of lymphocytes into the inflammatory
tissues. The aim of this study was to clarify the role of VLA4 or VCAM-1 in the
development of GVHR-induced hepatic lesions in our model. METHODS: B6 T spleen
cells were injected into (B6.C-H-2bm12xB6) F1 mice intravenously. Anti-VLA-4 mAbs
and/or anti-VCAM-1 mAbs were injected intraperitoneally at a dose of 2.5 mg/kg of
each mAbs per body weight of mouse. We examined the changes in GVHR-induced
hepatic lesions, serum levels of antimitochondrial antibodies (AMA) and cytokine
mRNA expressions of liver-infiltrating lymphocytes using H.E. and
immunohistochemical staining, enzyme-linked immunosorbent assay (ELISA), and
reverse transcription-polymerase chain reaction (RT-PCR), respectively. RESULTS:
Hepatic lesions of anti-VLA-4 mAbs-treated mice were inhibited compared with
those of GVHR mice. However, the administration of mAbs did not interfere with
the induction of splenomegaly, the invasion of CD4+, CD8+, B220+, or Mac-1+ cells
around bile ducts, nor the production of AMA. Liver-infiltrating CD4+ T cells
obtained from these treated mice did not alter the expression of T helper (Th)1
and Th2 cytokine mRNA. CONCLUSION: The results suggest that treatment with
antibodies against these adhesion molecules could inhibit the infiltration of
lymphocytes without affecting the Th1/Th2 balance. The blockade of VLA-4-mediated
cell infiltration into the liver in this model may have a possible novel
therapeutic role of VLA-4 mAbs.
PMID- 10782908
TI - Amoxicillin-clavulanic acid versus cefotaxime in the therapy of bacterial
infections in cirrhotic patients.
AB - BACKGROUND/AIM: Cefotaxime is considered the first-choice antibiotic for
empirical treatment in cirrhotic patients developing bacterial infections. It has
been suggested that amoxicillin-clavulanic acid could be an alternative to
cefotaxime, particularly in patients developing bacterial infections while on
prophylactic norfloxacin. The aim of the present study was to compare amoxicillin
clavulanic acid with cefotaxime in the treatment of bacterial infections in
cirrhosis. METHODS: Ninety-six hospitalized cirrhotic patients with suspicion of
bacterial infection were prospectively included and randomized into two groups:
one group (n=48) received amoxicillin-clavulanic acid, first intravenously 1 g
0.2 g every 8 h, and then orally 500 mg-125 mg every 8 h, and the other group
(n=48) received intravenous cefotaxime 1 g every 6 h. Patients were stratified
for previous prophylaxis with norfloxacin and ascitic fluid infection. RESULTS:
Sixteen patients were excluded from the analysis because bacterial infection was
not demonstrated or because of secondary peritonitis. Therefore, 38 patients from
the amoxicillin-clavulanic acid group and 42 from the cefotaxime group were
finally analyzed. There were 24 ascitic fluid infections in each group. Infection
resolution (86.8% vs 88%, 95% CI: -0.15 to 0.13, p NS), spontaneous bacterial
peritonitis resolution (87.5% vs 83.3%, 95% CI: -0.15 to 0.24, p NS), duration of
treatment, incidence of complications, time of hospitalization and hospital
mortality were similar in both groups. Considering patients on prophylactic
norfloxacin, infection resolution was also similar (100% vs 83.3%, 95% CI: -0.04
to 0.37, p NS). No adverse events were observed in either of the two groups. The
cost of antibiotics was statistically lower in the amoxicillin-clavulanic acid
group (p<0.001). CONCLUSIONS: Amoxicillin-clavulanic acid is as effective as
cefotaxime in the treatment of bacterial infections in cirrhotic patients, but is
less expensive and can be administered orally. These results suggest that
amoxicillin-clavulanic acid is an effective alternative to cefotaxime for the
empirical treatment of bacterial infections in cirrhosis.
PMID- 10782909
TI - Dexamethasone coupled to albumin is selectively taken up by rat nonparenchymal
liver cells and attenuates LPS-induced activation of hepatic cells.
AB - BACKGROUND/AIMS: The human serum albumin (HSA) conjugate Dexa10-HSA was designed
to specifically deliver the anti-inflammatory drug dexamethasone (Dexa) to
nonparenchymal cells (NPC) in the rat liver. NPC play an important role in the
pathogenesis of acute and chronic inflammatory liver diseases like fibrosis.
Targeting Dexa to these cells might reduce its adverse effects and increase the
efficacy. METHODS: Tissue and intrahepatic distributions of Dexa10-HSA were
assessed in normal and fibrotic rats with 125I-labelled conjugate and by
immunohistochemistry. The effect of the conjugate on lipopolysaccharide (LPS)
induced inflammation and cell activation was studied in vitro with precision-cut
liver slices and in vivo. RESULTS: Ten minutes after i.v. injection 72+/-13% and
65+/-12% of a tracer dose of Dexa10-HSA had been taken up in normal and fibrotic
livers, respectively. Unconjugated Dexa also accumulated in livers, but cellular
distribution studies revealed an accumulation in parenchymal cells (NPC vs.
parenchymal cell (PC) ratio=0.29+/-11, p<0.005) whereas Dexa10-HSA accumulated in
nonparenchymal cells (NPC/PC ratio=7.9+/-3.1). Both coupled and uncoupled Dexa
showed effective inhibition of LPS-induced NOx and TNFalpha production in
precision-cut liver slices. At low concentrations (0.02 microM), however, Dexa10
HSA was more efficient at inhibiting TNFalpha production than uncoupled Dexa. In
fibrotic rats Dexa10-HSA (3 mg/kg) and an equimolar amount of uncoupled Dexa
(0.22 mg/kg) both significantly promoted survival after LPS-induced acute
inflammation. CONCLUSION: Dexa10-HSA was at least as effective as uncoupled Dexa
at inhibiting LPS-induced effects, which indicates that HSA-bound Dexa is
pharmacologically active. Coupling Dexa to HSA shifted the accumulation of Dexa
from the PC to the NPC of livers. Since mediator release from NPC is crucial in
the initiation and propagation of the fibrotic process, selective delivery of
Dexa in NPC may improve the efficacy and safety of corticosteroid treatment of
liver fibrosis.
PMID- 10782910
TI - Expression of MAGE, GAGE and BAGE genes in human liver diseases: utility as
molecular markers for hepatocellular carcinoma.
AB - BACKGROUND/AIMS: The MAGE, GAGE and BAGE genes encode tumor antigens recognized
by autologous cytotoxic T lymphocytes. The aim of this study was to evaluate the
possibility of using these genes as molecular markers and as the targets of
specific immunotherapy for human hepatocellular carcinoma (HCC). METHODS: The
expressions of MAGE-1, MAGE-3, GAGE1-6, GAGE1-2 and BAGE mRNA in 33 surgically
resected HCC samples and 26 of their corresponding non-cancerous samples (11
liver cirrhosis and 15 chronic hepatitis) were studied by a reverse-transcription
polymerase chain reaction, and were compared with clinicopathological parameters.
The expression of MAGE-1 was also examined in 16 biopsied HCC samples. RESULTS:
MAGE-1, MAGE-3, GAGE1-6, GAGE1-2 and BAGE mRNA were expressed in 67%, 39%, 36%,
30%, and 21% of the HCC, respectively. At least one transcript was detected in
88% of the HCC, while no expression was observed in the non-cancerous livers.
There was no significant correlation between the expression of any of the tumor
antigens examined and the differentiation stage or size of the HCC. Especially,
MAGE-1 was highly expressed in small HCC with a diameter of less than 2 cm and in
well-differentiated HCC (81% and 70%, respectively), and was also expressed even
in alpha-fetoprotein-negative and PIVKA-II-negative HCC (58% and 76%,
respectively). The MAGE-1 expression was detected in 69% of biopsied HCC samples
and the expression was high in both small and well-differentiated HCC.
CONCLUSIONS: These tumor-specific antigens can be useful as molecular markers and
as the possible target molecules for the specific immunotherapy of human HCC.
PMID- 10782911
TI - Growth hormone induces CCAAT/enhancer binding protein alpha (C/EBPalpha) in
cultured rat hepatocytes.
AB - BACKGROUND/AIMS: The transcription factor CCAAT/enhancer binding protein alpha
(C/EBPalpha) is a transactivator of several genes in the liver, which are
regulated by growth hormone. METHODS: Growth hormone (100 ng/ml) was added to
primary rat hepatocytes cultured on a laminin-rich matrix. C/EBP mRNA and protein
levels were measured by RNase protection assay and Western blotting,
respectively. DNA binding activity was measured by electrophoretic mobility shift
assay (EMSA). RESULTS: Growth hormone treatment for 6 h to 3 days increased
C/EBPalpha mRNA levels. Addition of growth hormone for 24 h and 4 days also
enhanced the levels of the 42 and 30 kDa isoforms of immunoreactive C/EBPalpha.
EMSA showed that addition of growth hormone for 24 h enhanced the abundance of a
protein complex binding to a consensus C/EBP binding DNA oligonucleotide. This
protein complex was supershifted by antibodies directed against C/EBPalpha but
not against C/EBPbeta. There were no consistent effects on C/EBPbeta mRNA or
protein at any timepoint. The growth hormone effect on C/EBPalpha expression was
not affected by simultaneous incubation with insulin or glucocorticoids, two
hormones that previously have been reported to affect C/EBPs. CONCLUSIONS: Growth
hormone enhances the levels of C/EBPalpha mRNA and protein as well as the DNA
binding activity of C/EBPalpha in cultured rat hepatocytes.
PMID- 10782912
TI - The extent of synchronous initiation and termination of DNA synthesis in
regenerating mouse liver is dependent on connexin32 expressing gap junctions.
AB - BACKGROUND/AIMS: It has previously been shown in rat liver that the gap
junctional proteins connexin32 and connexin26 are downregulated when murine
hepatocytes are in the S-phase of the cell cycle. Therefore, it has been
hypothesized that loss of functional gap junctions could affect proliferation of
hepatocytes. This study aimed to check this hypothesis. METHODS: We searched for
differences in liver regeneration after two-thirds partial hepatectomy between
connexin32-deficient and wild-type mice. RESULTS: The ratio of liver to body
weight in regenerating liver was not affected by loss of the connexin32 gene. The
peak of DNA synthesis occurred at the same time, i.e. 36 to 96 h after partial
hepatectomy, in connexin32-deficient and wild-type liver. During this time,
however, only about half as many nuclei of hepatocytes in connexin32-deficient
liver incorporated bromodeoxyuridine, compared to wild-type liver. Furthermore, 1
2 weeks after full recovery of liver mass, we detected a higher level of
bromodeoxyuridine incorporation into hepatocytes of connexin32-deficient than in
wild-type liver. CONCLUSIONS: Loss of connexin32 protein and/or diminished
expression of connexin26 did not promote G0/1-S transition of hepatocytes in two
thirds hepatectomized mouse livers. Instead, the extent of synchronous initiation
and termination of DNA synthesis in regenerating liver was altered in connexin32
deficient mice.
PMID- 10782914
TI - Epidermal growth factor and insulin-like growth factor I upregulate the
expression of the epidermal growth factor system in rat liver.
AB - BACKGROUND/AIM: Both epidermal growth factor and insulin-like growth factor I
play a role in connection with the liver. In the present study, the possible
interaction of these two growth factor systems was studied by investigating the
effect of epidermal growth factor or insulin-like growth factor I treatment on
the expression of the epidermal growth factor receptor, and its activating
ligands, transforming growth factor-alpha and epidermal growth factor. METHODS:
Fifty-five male rats received no treatment, human recombinant epidermal growth
factor or human recombinant insulin-like growth factor I for either 3 or 7 days.
The amount of epidermal growth factor receptor, transforming growth factor-alpha,
and epidermal growth factor mRNA was quantitated by a calibrated user-friendly RT
PCR assay (CURT-PCR), and the expression of transforming growth factor-alpha and
epidermal growth factor peptides was quantitated by ELISA. RESULTS: Control liver
(n=16) contained a mean (+/-SD) value of 12.7+/-7.4x10(-18) mol epidermal growth
factor receptor mRNA, 3.8+/-2.0x10(-18) mol transforming growth factor-alpha mRNA
and 0.8+/-0.4x10(-18) mol epidermal growth factor mRNA per microg total RNA and
9.8+/-1.6 fmol/mg protein epidermal growth factor and 144+/-22 fmol/mg protein
transforming growth factor-alpha. Both epidermal growth factor and insulin-like
growth factor I treatment increased the expression of mRNA for transforming
growth factor-alpha and epidermal growth factor receptor, as well as the
expression of transforming growth factor-alpha peptide. The level of epidermal
growth factor receptor and transforming growth factor-alpha mRNA expression was
found to correlate both in control and growth factor-treated animals, whereas the
expression of epidermal growth factor receptor and epidermal growth factor showed
no correlation. Marked differences were seen upon activation of the two growth
factor systems, as epidermal growth factor, but not insulin-like growth factor I
treatment, increased the plasma concentration of urea and decreased the
concentration of insulin-like growth factor I and the liver enzymes, alanine
aminotransferase and alkaline phosphatase. CONCLUSION: Our results show that
epidermal growth factor and insulin-like growth factor I, which belong to two
different growth factor systems, both induce a correlated upregulation of
transforming growth factor-alpha and epidermal growth factor receptor mRNA in rat
liver. Although marked differences were observed after treatment with either
epidermal growth factor or insulin-like growth factor I on the liver as reflected
in the plasma concentrations of e.g. liver enzymes, a common motif in their
action involves an upregulation of the expression of the epidermal growth factor
system.
PMID- 10782913
TI - Differential suppression of liver-specific genes in regenerating rat liver
induced by extended hepatectomy.
AB - BACKGROUND/AIMS: The function of the remnant liver is critical to survival of
patients following an extended hepatectomy. The aim of this study was to
determine whether proliferating hepatocytes in the remnant liver preserve the
expression of liver-specific genes. METHODS: Using regenerating rat livers after
30, 70, and 90% partial hepatectomy (PHx), Northern blot analyses were performed
with probes for seven liver-specific genes, six growth-related genes, two
housekeeping genes and two acute phase reactant protein genes. RESULTS: During
the regeneration after 90% PHx, the transcription of liver-specific genes showed
three chronological patterns: transcription of serum albumin and cytochrome P450
2B decreased rapidly and reached a nadir at 6 to 24 h after PHx; those of
apolipoprotein A-1, phosphoenolpyruvate carboxykinase and ornithine
transcarbamylase decreased gradually until 24 to 48 h; those of UDP
glucuronosyltransferase and hepatocyte nuclear factor 4 did not show any changes
until 48 h after PHx. In contrast, expression levels of all the growth-related
genes and of housekeeping genes increased rapidly after PHx. After 30 and 70%
PHx, expression of these genes changed in a similar manner to the 90% PHx case
but to a lower extent. CONCLUSIONS: Based upon the fractions of Ki-67 positive
hepatocytes in remnant livers, we could estimate the degree of expression of each
liver-specific gene in the proliferating hepatocytes. The serum albumin gene was
completely suppressed, while that encoding UDP-glucuronosyltransferase was not
affected. These results correlated well with the patterns of albumin and
bilirubin in rat serum after PHx. Other liver-specific genes were moderately
suppressed in proliferating hepatocytes. Thus, expression of liver-specific gene
is differentially suppressed when hepatocytes enter a proliferation cycle. Those
that are unaffected may be indispensable for maintaining the homeostasis of the
living organism.
PMID- 10782915
TI - Liver xenotransplantation: changes in lipid and lipoprotein concentration after
long-term graft survival.
AB - BACKGROUND/AIMS: Today, scientists devote considerable effort to the study of
mechanisms of xenograft rejection, but with liver xenotransplantation (XTx)
researchers face the added problem of metabolic incompatibility between species.
To date, there have been few studies of molecular xenogeneic interactions,
perhaps because little progress has been made in solving immunological problems.
This study is an initial analysis of lipoprotein metabolism in a hamster-to-rat
hepatic xenotransplantation model. METHODS: There were 6 experimental groups
(n=8): (1) male Sprague-Dawley (S.D.) rats (220-280 g); (2) male Golden Syrian
hamsters (100-150 g); (3) S.D. rats, "sham" operation with immunosuppression; (4)
S.D. rat-to-S.D. rat alloTx; (5) S.D. rat-to-S.D. rat alloTx with
immunosuppression; (6) XTx hamster G.S-to-S.D. rat with immunosuppression.
Mofetil mycophenolate (25 mg/kg/d) was administered for 14 days and FK506 (0.2
mg/kg/d) for 45 days (groups 3, 5 and 6). After 24 h fasting, animals were
sacrificed (day +50 postransplantation) and a complete lipoprotein profile was
determined. Serum lipoproteins were subfractioned by ultracentrifugation in
density gradient. RESULTS: There was a large increase in serum lipid levels in
xenografted rats compared with control rats and allografted rats. Xenografted
rats presented a severely altered lipoprotein profile compared with normal rats.
Surprisingly, the characterisation of lipoproteins in xenografted rats displayed
the same composition as donor animals. Histological study did not show signs of
alteration of the hepatic architecture. CONCLUSIONS: Since the liver is the main
solid organ co-ordinator of metabolic pathways, such as lipid metabolism, hepatic
xenotransplantation makes changes in lipid concentrations in the recipient and
also changes in lipid compositions of lipoproteins. Hepatic xenotransplantation
is not a feasible solution given the organ's metabolic complexity.
PMID- 10782916
TI - TTV infection in patients with acute hepatitis of defined aetiology and in acute
non-A-E hepatitis.
AB - BACKGROUND/AIMS: Recently, the presence of a novel nonenveloped single-stranded
DNA virus (TTV) has been associated with either acute or chronic hepatitis of
unknown aetiology, suggesting a possible aetiological role. The aim of this study
was to evaluate the prevalence, the significance and the clinical impact of TTV
infection in patients with acute viral hepatitis of defined aetiology and in
patients with non-A-E acute hepatitis. METHODS: TTV-DNA was tested by hemi-nested
PCR in serum samples collected from 121 patients during and after acute hepatitis
(103 with acute viral hepatitis of defined aetiology and 18 with acute non-A-E
hepatitis) and in 30 healthy controls. RESULTS: Overall, the rate of TTV
infection was 12.6% (13/103) in patients with acute hepatitis of defined
aetiology, 16.6% (3/18) in patients with non-A-E acute hepatitis and 6.6% (2/30)
in the healthy control group, (p=n.s). TTV-DNA was detected in the following
proportions: hepatitis B, 13.2% (7/53); hepatitis C, 16.6% (4/24); hepatitis A,
4.7% (1/21); hepatitis E 20% (1/5). Moreover, acute hepatitis with and without
TTV infection/coinfection were comparable in terms of both liver biochemistry and
chronicity rate. The results of TTV re-testing after serial dilutions of six TTV
DNA positive serum samples during and after the peak of liver transaminases
failed to demonstrate a correlation between liver damage and viral titre.
CONCLUSIONS: The prevalence of TTV infection appeared to be comparable in
patients with non-A-E hepatitis, in acute hepatitis of defined aetiology and in
the control group. Hence, an aetiological role of TTV for acute hepatitis of
unknown aetiology seems questionable. Moreover, TTV infection does not modify the
natural history of acute hepatitis of defined aetiology.
PMID- 10782917
TI - Changes in serum tissue inhibitor of matrix metalloproteinase-1 after interferon
alpha treatment in chronic hepatitis C.
AB - BACKGROUND/AIMS: The aim of this study was to evaluate the effect of interferon
alpha on the metabolism of hepatic fibrosis in chronic hepatitis C, monitoring
serum tissue inhibitor of matrix metalloproteinase-1(TIMP-1) and N-terminal
propeptide of type III procollagen (PIIINP) reflecting fibrolysis and
fibrogenesis, respectively. METHODS: Serum levels of TIMP-1 and PIIINP were
serially measured in 112 treated and 31 untreated patients with chronic hepatitis
C during and after interferon alpha treatment. Furthermore, the relationships
between these serum markers and the grades of hepatic fibrosis after interferon
therapy were also investigated. RESULTS: Serum pretreatment levels of TIMP-1 and
PIIINP in non-responders were significantly higher than those in sustained and
transient responders, but these levels were not different in the latter two
groups. Serum TIMP-1 levels decreased significantly during and after treatment in
sustained responders, and decreased temporarily at the end of treatment in
transient responders, although these levels were unchanged during and after
treatment in non-responders and untreated patients. In contrast, serum PIIINP
levels decreased significantly during and after treatment in all treated groups,
but were unchanged in untreated patients. Histological examination 12 months
after interferon was completed demonstrated that hepatic fibrosis improved in
sustained responders and was unchanged in transient and non-responders, but
progressed in untreated patients. CONCLUSION: These results suggest that
interferon alpha treatment of chronic hepatitis C may improve hepatic fibrosis in
sustained responders by the acceleration of fibrolysis as well as the inhibition
of fibrogenesis, and that it may suppress the progression of hepatic fibrosis in
non-sustained responders by the inhibition of fibrogenesis.
PMID- 10782919
TI - Ursodeoxycholic acid for primary biliary cirrhosis: lessons from the past--issues
for the future.
PMID- 10782920
TI - Mallory bodies revisited.
PMID- 10782918
TI - HCV-related fibrosis progression following liver transplantation: increase in
recent years.
AB - BACKGROUND/AIMS: The natural history and predictors of HCV-related disease
severity post-transplantation are uncertain. The aims of this study were to
define the natural history of post-transplantation HCV infection by assessing the
rate of fibrosis progression, to determine if the post-transplantation natural
history differs from that observed pre-transplantation, and to identify
predictors of post-transplantation disease progression. METHODS: Post
transplantation biopsies (mean: 3+/-1.6/patient) from 284 patients were scored
according to histologic stage, using the method of Desmet et al. Change in
fibrosis score (fibrosis progression/year) post-transplantation was used as the
primary outcome. Predictors analyzed included viral factors (genotype and viral
load at transplantation), patient demographics, year of transplantation, country
of transplantation, pre-transplantation fibrosis progression, immunosuppression
and laboratory data. RESULTS: There was a linear association between change in
fibrosis score and time from transplantation, with a median rate of fibrosis
progression per year of 0.3 (0.004-2.19/year). Using parametric time-to-event
analysis, the expected median duration to cirrhosis was 10 years. The rate of
post-transplantation fibrosis progression was significantly higher than pre
transplantation (0.2/year (0.09-0.8) p<0.0001), and higher in Spanish than US
centers (0.48 (0.01-2.19) vs 0.28 (0.004-2.08); p=0.09) despite similar
progression rates prior to transplantation. Variables independently associated
with post-transplantation progression included year of transplantation
(p=0.0001), race (p=0.02), number of methyl-prednisolone boluses (p=0.03), and
HCV RNA levels at transplantation (p=0.01). CONCLUSIONS: HCV-related disease
progression is accelerated in immunocompromised compared to immunocompetent
patients, with a progressive increase in patients who have recently undergone
liver transplantation. Changes in patient management post-transplantation over
time and between transplant centers may account for the increase in fibrosis
progression observed in recent years.
PMID- 10782921
TI - Undetectable serum caeruloplasmin in a woman with chronic hepatitis C infection.
AB - There are many causes of a low serum caeruloplasmin. Not only may this be a
feature of Wilson's disease, but a low level may be found in association with
chronic liver disease of any cause. We report here a case where undetectable
serum caeruloplasmin was found during routine investigation of a woman with
hepatitis C viral infection.
PMID- 10782922
TI - Images in hepatology. Acute cholecystitis revealing a diaphragm disinsertion.
PMID- 10782923
TI - The genetics of osteoporosis: 'complexities and difficulties'.
AB - Osteoporosis is characterized by a decrease in bone mass as well as a
deterioration of the bone architecture resulting in an increased risk of
fracture. Although the disease is multifactorial, twin studies have shown that
genetic factors account for up to 80% of the variance in bone mineral density,
the best known predictor of the risk of osteoporosis. Some loci, such as the
vitamin D and estrogen receptor genes, as well as the collagen type Ialpha1
locus, are promising genetic determinants of bone mass, and possibly other bone
phenotypes, but this is controversial and the molecular basis of osteoporosis
remains largely undefined. Considering that the effect of each candidate gene is
expected to be modest, discrepancies between allelic association studies may have
arisen because different populations carry different genetic backgrounds and
exposure to environmental factors. Also, we realize the importance of gene-gene
as well as gene-environment interactions as significant determinants of bone
density and risk of osteoporosis. The use of new tools such as small nucleotide
polymorphism maps now allows the possibility to perform allelic association
studies in the context of whole-genome search. However, specific study design
strategies in large epidemiological studies as well as the best statistical
approach will need to be established. We may expect the development of population
specific at-risk profiles for osteoporosis that would include genetic and
environmental factors, as well as their interactions. This should eventually lead
to better prevention strategies and more adapted therapies against osteoporosis.
PMID- 10782924
TI - Xolotl: god of monstrosities.
PMID- 10782925
TI - Comparison of the role of dopamine, serotonin, and noradrenaline genes in ADHD,
ODD and conduct disorder: multivariate regression analysis of 20 genes.
AB - The present study is based on the proposal that complex disorders resulting from
the effects of multiple genes are best investigated by simultaneously examining
multiple candidate genes in the same group of subjects. We have examined the
effect of 20 genes for dopamine, serotonin, and noradrenergic metabolism on a
quantitative score for attention deficit hyperactivity disorder (ADHD) in 336
unrelated Caucasian subjects. The genotypes of each gene were assigned a score
from 0 to 2, based on results from the literature or studies in an independent
set of subjects (literature-based scoring), or results based on analysis of
variance for the sample (optimized gene scoring). Multivariate linear regression
analysis with backward elimination was used to determine which genes contributed
most to the phenotype for both coding methods. For optimized gene scoring, three
dopamine genes contributed to 2.3% of the variance, p = 0.052; three serotonin
genes contributed to 3%, p = 0.015; and six adrenergic genes contributed to 6.9%,
p = 0.0006. For all genes combined, 12 genes contributed to 11.6% of the
variance, p = 0.0001. These results indicate that the adrenergic genes play a
greater role in ADHD than either the dopaminergic or serotonergic genes combined.
The results using literature-based gene scoring were similar. An examination of
two additional comorbid phenotypes, conduct disorder and oppositional defiant
disorder (ODD), indicated they shared genes with ADHD. For ODD different
genotypes of the same genes were often used. These results support the value of
the simultaneous examination of multiple candidate genes.
PMID- 10782926
TI - A pilot study of the possible role of familial defects in anticoagulation as a
cause for terminal limb reduction malformations.
AB - Terminal limb deficiency defects affect between three and eight babies per 10000
births and are an important cause of disability. Established causes for these
malformations include single gene disorders, chromosome abnormalities,
teratogens, and amniotic bands. However, the etiology remains unknown in a
significant proportion of cases. Several authors have hypothesized that vascular
accidents, either bleeds or vessel occlusions, may underlie a substantial number
of cases; but, for the most part, the origin of such events remains obscure. Over
the past several years, an increasing number of genetic thrombophilias have been
recognized and have been associated with increased risks of peri- and post-natal
occlusive disease, and with higher rates of recurrent pregnancy loss. The
hypothesis to be examined in this pilot study was whether the inherited
thrombophilias might be associated with a vascular cause of some terminal limb
deficiency defects. Towards that end, protein C, protein S, antithrombin III,
factor V Leiden mutation, prothrombin (G20210A) variant,
methylenetetrahydrofolate reductase variant, plasma homocysteine, anticardiolipin
IgM and IgG antibodies, and lipoprotein (a) were measured in 24 mother-child
pairs in which the child had a terminal limb defect. The results provided some
evidence that there may be an excess of thrombophilias present in such families
and that they may play some etiological role in a subset of these types of limb
malformations.
PMID- 10782928
TI - A rapid fluorescent multiplexed-PCR analysis (FMPA) for founder mutations in the
BRCA1 and BRCA2 genes.
AB - Mutations of the BRCA1 and BRCA2 genes account for approximately 80% of
hereditary breast/ovarian cancer families, but the size of these two genes makes
mutation analysis time-consuming and technically challenging. In some populations
such as the Ashkenazi Jewish and the French-Canadian, a small number of recurrent
founder mutations account for the majority of mutations in cancer families. We
have therefore developed two rapid genetic screening tests, which allow us to
detect three frequent frameshift mutations in the Ashkenazi Jewish population and
five frameshift mutations in the French-Canadian population. These fluorescent
non-radioactive methods permit the simultaneous detection of multiple mutations
by generating multiplexed PCR-amplified gene fragments, and by discriminating
these on the basis of their size in a denaturing polyacrylamide gel. Using these
methods, we were able to correctly identify all mutants in a blinded analysis of
276 DNA samples, including 30 derived from paraffin-embedded tumor samples and 10
from buccal-cell brushes, with no false positive or false negative results. These
techniques designed for the direct detection of recurrent mutations in the BRCA1
and BRCA2 genes, have the advantages of being efficient, sensitive, cost
effective, and are applicable to large scale screening for epidemiologic studies.
PMID- 10782927
TI - A germline mutation at the extreme 3' end of the APC gene results in a severe
desmoid phenotype and is associated with overexpression of beta-catenin in the
desmoid tumor.
AB - Desmoid tumors arise sporadically or as part of the extraintestinal
manifestations of familial adenomatous polyposis (FAP). In FAP, two distinct
clinical presentations of the desmoid phenotype are seen: 1) one or a few desmoid
tumors present predominantly in the abdominal wall or the abdomen; 2) a florid
proliferation of tumors early in life, mostly near the axial skeleton or
extremities. These different phenotypes have been associated with different sites
of germline mutations in the adenomatous polyposis coli gene (APC gene). We
present a large, French-Canadian kindred with a florid desmoid tumor phenotype
caused by a germline mutation at codon 2643-2644 of the APC gene. The phenotype
was characterized by the early onset of multiple tumors, arising near the axial
skeleton and in proximal extremities. The penetrance of desmoid tumors was near
100% in this kindred. However, the expression of the disease was variable amongst
the different affected relatives. Many gene carriers had cutaneous cysts.
Polyposis of the colon was rarely observed in the affected individuals and we did
not document upper gastro-intestinal polyps. The mutant APC allele did not
express a stable truncated protein in vivo. Molecular analysis of the proband's
tumor DNA revealed a somatic inactivating mutation of the wild-type allele.
Immunohistochemistry on the tumor also demonstrated elevated levels of beta
catenin. The present study demonstrates that this extreme 3' APC mutation is
associated with a severely penetrant desmoid phenotype and attenuated polyposis
coli. It also suggests the involvement of the beta-catenin pathway in the
development of desmoid tumors in FAP. The natural history of the disease is
variable between individuals, and surgical interventions have to be timed
appropriately due to the frequent recurrences.
PMID- 10782929
TI - Molecular analysis of the 5'-flanking region of the neurofibromatosis type 1
(NF1) gene: identification of five sequence variants.
AB - Dideoxy fingerprinting was used to analyse the 5' flanking region of the
neurofibromin (NF1) gene in a panel of 380 neurofibromatosis type 1 (NF1)
patients. Five polymorphisms/rare variants were identified at positions -412, -
402, + 16, + 25 and + 132, but control data indicated that these were unlikely to
be of pathological significance. Promoter mutations in the NF1 gene are not,
therefore, a common cause of NF1. This notwithstanding, a reporter gene assay was
performed to determine if these variants could affect the expression of the NF1
gene, and all three changes in the 5'-untranslated region (UTR) (+ 16, + 25, +
132) were found to be associated with a 60-70% increase in reporter gene
expression.
PMID- 10782930
TI - Identification of four novel mutations of the low-density lipoprotein receptor
gene in Korean patients with familial hypercholesterolemia.
AB - To obtain insight into the genetic variation of the low-density lipoprotein (LDL)
receptor gene in Korean patients with familial hypercholesterolemia (FH), we used
single-strand conformation polymorphism to screen all 18 exons and a promotor of
the LDL receptor gene in 20 unrelated Korean FH patients. Four novel point
mutations were detected in 5 FH patients and were characterized by sequence
analysis. Of them, one is a nonsense mutation, a Glu-->Stop (CAG-->TAG) at codon
161, and results in a large deletion. The other three, which were a Ala-->Glu
(GCG-->GAG) mutation at signal peptide, Cys-->Tyr (TGC-->TAC) at codon 210, and
Pro-->Leu (CTG-->CCG) at codon 584, were novel missense mutations, which modified
the highly conserved region of the LDL receptor gene. All these mutations were
absent in normolipidemic controls and were associated in heterozygote carriers
with clinical signs of FH. Identification of these novel mutations provides
another example of the molecular heterogeneity of the LDL receptor gene mutations
causing FH.
PMID- 10782931
TI - Spina bifida and common mutations at the homocysteine metabolism pathway.
PMID- 10782932
TI - Pseudodominant inheritance of DFNB1 deafness due to the common 35delG mutation.
PMID- 10782933
TI - Identification of cystic fibrosis mutations in Oman.
PMID- 10782934
TI - Systematic review of aetiology and treatment of post-stroke hand oedema and
shoulder-hand syndrome.
AB - Studies on the aetiology and treatment of post-stroke hand oedema and shoulder
hand syndrome (SHS) published from January 1973 until August 1998 were
identified. Eleven studies were included with at least some control for
confounding. These were evaluated on 11 methodological criteria and by
standardized effect sizes. There were five aetiological studies: four cohort
studies and one study consisting of two case series using a within-subjects
design. The matters investigated included lymph scintigraphy in hand oedema, bone
scintigraphy, putative risk factors and the existence of autonomic dysregulation
and peripheral nerve lesions in SHS. There were six therapeutic studies: one
randomized controlled trial, one non-randomized controlled trial, one cohort
study and three case series, of which two studies used a within-subjects design.
These studies investigated continuous passive motion and neuromuscular
stimulation in hand oedema as well as oral corticosteroids, intramuscular
calcitonin and trauma prevention in SHS. A great diversity of pathophysiological
and therapeutic insight was found. Based on systematic analysis of the
literature, the following conclusions seem justified: (i) the shoulder is
involved in only half of the cases with painful swelling of wrist and hand,
suggesting a "wrist-hand syndrome" between simple hand oedema and SHS; (ii) hand
oedema is not lymphoedema; (iii) SHS usually coincides with increased arterial
blood flow; (iv) trauma causes aseptic joint inflammations in SHS; (v) no
specific treatment has yet proven its advantage over other physical methods for
reducing hand oedema; and (vi) oral corticosteroids are the most effective
treatment for SHS.
PMID- 10782935
TI - Effect of swallowing training on swallowing disorders in Parkinson's disease.
AB - The purpose of the present study was to determine whether swallowing training
improves swallowing function in patients with Parkinson's disease. Ten patients
(5 males, 5 females) who had symptoms of dysphagia and 12 healthy volunteers were
studied. The initiation time of the swallowing reflex, the "premotor time" (PMT),
was calculated from an electromyogram of the submental muscles before and after
swallowing training. Patients with Parkinson's disease had a significantly longer
PMT (p = 0.0014) than did healthy controls. There was no correlation between PMT
and the duration of the disease (r = -0.146; p = 0.6867) or the patient's age (r
= 0.602; p = 0.0653). After swallowing training, the patients' PMTs decreased
significantly (p = 0.0051).
PMID- 10782936
TI - Effect of cooling suit treatment in patients with multiple sclerosis evaluated by
evoked potentials.
AB - The aim of the present study was to determine whether any significant alterations
of evoked potentials could be detected after treatment of patients with multiple
sclerosis with a cooling suit. All patients had previously experienced a positive
effect of this treatment. Six patients were investigated with visual, sensory and
motor evoked potentials and six further patients with only motor evoked
potentials. All patients had relevant clinical lesions. The mean values for the
group of patients were similar before and after cooling, but a few individuals
showed a substantial improvement of motor evoked potentials after cooling, with
increased amplitude and/or shortened central motor conduction time. There was
also a weak, but significant, correlation between temperature decrements and the
reduction of central motor conduction time. However, since the central motor
conduction times of most patients were only slightly affected, this effect could
explain only a small part of the beneficial effect of cooling. Effects on
cognition and executive ability or improvement of spasticity may be of greater
importance.
PMID- 10782937
TI - Cooling suit for multiple sclerosis: functional improvement in daily living?
AB - Eight cryopositive patients with multiple sclerosis used cooling suits for 40
minutes regularly one or more times daily for a six-week period. The patients
were given repeated motor and mental tests by a physiotherapist in order to
determine whether they had a continuous beneficial effect of cooling during this
period. Additionally, selected activities of daily living performed in the
patient's homes were evaluated and registered according to Assessment of Motor
and Process Skills (AMPS). Six out of eight patients improved in at least one
motor test and all patients improved according to AMPS. For one of the patients,
who was profoundly handicapped, the effect of cooling was evaluated differently.
PMID- 10782938
TI - Simple assessment of outcome after acute brain injury using the Glasgow Outcome
Scale.
AB - To evaluate alternative methods of determining Glasgow Outcome Scale scores, a
postal survey was made of 288 general practitioners and 128 relatives of patients
who had sustained acute brain injuries 5-7 years previously. The Glasgow Outcome
Scale score from the general practitioner and relative were compared with that
calculated from questionnaire information by an experienced rater. There was poor
agreement between general practitioner and rater (K = 0.17) and relative and
rater (K = 0.35) scores. Both general practitioners and relatives indicated more
favourable outcomes than the rater, with a higher level of agreement (K = 0.61)
between them. When Glasgow Outcome Scale scores are used, the methods employed
should be valid and reliable; failure to ensure this may be responsible for a
considerable proportion of variability in reported studies of brain injury
outcome.
PMID- 10782939
TI - Functional electrical stimulation-assisted walking for persons with incomplete
spinal injuries: longitudinal changes in maximal overground walking speed.
AB - This study investigated the changes in maximal overground walking speed (MOWS)
that occurred during walking training with a functional electrical stimulation
(FES) orthosis by chronic spinal cord injured persons with incomplete motor
function loss. The average walking speed over a distance of 10 m was calculated
while the participants (n = 14) used their FES orthosis with and without power as
well as with the various ambulatory assistive devices available. Within the first
year of use, walking with an FES orthosis facilitated use of more advanced
ambulatory assistive devices (10/14), improvements in functional mobility (12/14)
and increases in the combined (0.26 m/s) and therapeutic (0.25 m/s) MOWS that
were correlated (combined: r = 0.57; therapeutic: r = 0.69) with their respective
initial MOWS. A longitudinal analysis showed that increases in MOWS followed a
pattern of changes best described by either an exponential association (8/12) or
a linear (4/12) model. These changes were similar for the combined and
therapeutic MOWS (7/11) as well as for the different ambulatory assistive devices
(8/9). It is concluded that the increased MOWS during walking training using the
FES orthosis is mostly due to a therapeutic effect, implying that mechanisms of
plasticity occur during such a training paradigm.
PMID- 10782940
TI - Quadriceps strength in women with a previous hip fracture: relationships to
physical ability and bone mass.
AB - Associations between physical ability, level of current physical activity and
bone mass were examined in 47 elderly women (mean age 80 years) who had suffered
from a hip fracture 3-36 months (mean 17 months) previously. Measures of physical
ability included isokinetic quadriceps strength of both the non-fractured and
fractured leg, and walking and stair climbing speed. An estimate of current
physical activity was made using the Northwick Park activity index questionnaire
specifically designed for hip fracture patients. Bone mineral density of the
spine and hip (Ward's triangle, femoral neck and trochanter) was assessed by dual
energy X-ray absorptiometry. Relationships between the measured parameters were
analysed using multiple regression analyses, taking into account the confounding
effects of age, height, weight and months since fracture. Quadriceps strength of
the fractured leg was on average 18% lower than that of the contralateral leg (p
< 0.001). Quadriceps strength of the fractured leg proved to be the most robust
predictor of walking speed (Rpartial = 0.69, p < 0.0001), stair climbing speed
(Rpartial = 0.46, p < 0.001) and the activity index (Rpartial = 0.56, p <
0.0001). Bone mineral density was independently predicted only by body weight
(Rpartial range: 0.45-0.72, p < 0.001), not by any of the parameters of physical
ability or by the Northwick Park activity index. In conclusion, quadriceps
strength is markedly affected in women with a previous hip fracture and is
associated with walking ability and level of physical activity. This study showed
that bone mass is linked to body weight, not to physical ability and activity.
Thus, the main benefit of muscle strengthening exercises in these women may be to
promote mobility.
PMID- 10782941
TI - Impact of age on improvement in health-related quality of life 5 years after
coronary artery bypass grafting.
AB - The aim of this study was to describe the relief of symptoms and improvement in
other aspects of health-related quality of life 5 years after coronary artery by
pass grafting in relation to age. Patients in western Sweden were approached with
an inquiry prior to surgery and 5 years after the operation. Health-related
quality of life was estimated with 3 different instruments: Physical Activity
Score (PAS), Nottingham Health Profile (NHP), Psychological General Well-Being
Index (PGWB). Prior to surgery patients were approached either in the ward or by
post and 5 years after surgery they were approached by post. A total of 1719
patients were available for the survey, of whom 876 (51%) responded to the survey
both prior to and after 5 years. Among the 876 respondents 287 were <60 years,
331 were 60-67 years and 258 were >67 years. In terms of physical activity, chest
pain and dyspnoea, a similar improvement was observed regardless of age. In terms
of health-related quality of life questionnaires, there was an inverse
association between age and improvement when using PAS and a similar trend was
observed with NHP and PGWB. In conclusion, 5 years after coronary artery bypass
grafting relief of symptoms and improvement in physical activity was not
associated with age, whereas improvement in other aspects of health-related
quality of life tended to be less marked in elderly people. Overall age seemed to
have a small impact on the improved well-being 5 years after coronary surgery.
However, due to the limited response rate the results may not be applicable to a
non-selected coronary artery bypass grafting population.
PMID- 10782942
TI - The forensic anthropology legacy of T. Dale Stewart (1901-1997).
AB - T. Dale Stewart (1901-1997) began his Smithsonian career as a temporary aide to
Ales Hrdlicka (1869-1943) in 1924. At the time of his death in 1997, he was
regarded world-wide as an authority who led the professional development of
American forensic anthropology. He was a prodigious researcher, best known for
his meticulous attention to detail, balanced scientific judgment, keen sense of
research design, and ability for synthesis. Stewart's publications, extensive
casework for the FBI and others, his court testimony, publications, professional
contacts, and organizational activity merit him a prominent place in the history
of American forensic anthropology.
PMID- 10782943
TI - Becoming respectable: T. Dale Stewart and the acceptance of forensic anthropology
in the academic community.
AB - Before World War II, forensic anthropology was of peripheral interest to a few
anthropologists willing to assist in investigations by law enforcement agencies.
A strong bias that "police work" was unbecoming to the scholarly pursuits of
academics persisted into the post-war years. Changes took place as a consequence
of T. Dale Stewart's case work in the identification of human remains with the
FBI from 1943 to 1969, his directorship of the National Museum of Natural History
(Smithsonian Institution) beginning in 1962, and his work with the Armed Forces
after 1948. This paper discusses the historic period of transition of attitudes
and practices in the contexts of Stewart's contributions and the cases and
teaching programs of one of his contemporaries. Theodore D. McCown at the
University of California at Berkeley, during the period of 1939 to 1969. The
establishment of the Physical Anthropology Section within the American Academy of
Forensic Sciences in 1972 and the creation of the T. Dale Stewart award for
distinguished service in forensic anthropology advanced those laboratory research
programs and medical-legal investigations conducted by present-day forensic
anthropologists.
PMID- 10782944
TI - Dr. T. Dale Stewart's travels.
AB - Renowned forensic physical anthropologist Dr. T. Dale Stewart traveled
extensively to countries all over the world. The reasons for his journeys were
manifold. He did fieldwork, took part in congresses, visited scientific
institutions, and lectured by invitation at various universities. This paper
deals with his journeys in general and with his four visits to Czechoslovakia in
particular. Three of them were undertaken in connection with scientific
congresses dedicated to Dr. Ales Hrdlicka. Dr. Stewart, as Hrdlicka's successor
in the Smithsonian Institution, always chose an appropriate topic for his
lecture. His visits to Hrdlicka's native country and town contributed to better
mutual understanding and exchange of ideas between physical anthropologists and
anatomists from both countries, the USA and Czechoslovakia (the today separate
Czech and Slovak Republics).
PMID- 10782947
TI - T. Dale Stewart's perspective on his career as a forensic anthropologist at the
Smithsonian.
AB - T. D. Stewart (1901-1997) is internationally recognized as an early leader in
forensic anthropology. In a series of taped interviews in 1975 and in 1986,
Stewart discusses his professional development. The interviews document his early
education in Delta, Pennsylvania, his long career at the Smithsonian Institution
in Washington, DC and aspects of his many contributions to forensic anthropology.
His well-known careful editorial work and exhaustive, problem-oriented research
approach may have been influenced by his early training in his hometown bank and
his many years of apprenticeship under Ales Hrdlicka (1869-1943). Stewart
describes aspects of the difficulties of working for Hrdlicka, yet credits the
work ethic established by him as a formative factor in his own prodigious
productivity.
PMID- 10782948
TI - Publications of T. Dale Stewart (1901-1997).
AB - T. D. Stewart (1901-1997) published at least 394 works between the years 1929 and
1992. These include 118 reviews, 40 abstracts, 227 articles or book chapters,
five edited volumes, and four books or monographs.
PMID- 10782946
TI - Archaeology, science and forensic anthropology: a tribute to Dr T. Dale Stewart.
AB - The name, T. Dale Stewart is synonymous with physical anthropology. To many
members of the physical anthropology section, particularly those born in the
latter half of this century, he is perhaps best known for his 1979 Essentials of
Forensic Anthropology. Without a doubt, much of the foundation of this discipline
rests upon his teachings and influence. Few knew him in the capacity that William
M. Bass did, as T. Dale Stewart was a member of Bass doctoral committee. Bass was
greatly influenced during the time he spent working with Dr. Stewart in the
1950's and the instruction and guidance Stewart instilled in Bass has and will
continue to be passed on to subsequent generations. Research was Dale Stewart's
main emphasis and he succeeded in demonstrating the value of investigation and
how results were crucial in explaining many of the processes manifest on skeletal
material. Clearly his hypothesis-based approach became essential to skeletal
biology and numerous procedures and methods employed in the field are synonymous
with the teachings of Dr. T. Dale Stewart. By reflecting on several recently
completed interdisciplinary research projects, the far-reaching impact of his
knowledge and instruction can be demonstrated.
PMID- 10782945
TI - T. Dale Stewart: remembrances of a scholar and colleague.
AB - T. Dale Stewart's contributions had a considerable influence on the development
and early evolution of the field of forensic anthropology. This composition
provides a perception of Stewart from the viewpoint of an advanced graduate
student and then a young colleague. It explains, in part, the quiet leadership
and assistance that Stewart provided at various professional and familiar levels
to one individual and is indicative of the broad effect that Stewart had on
generations of students and professionals in anthropology, osteology and forensic
anthropology.
PMID- 10782949
TI - Sex differences in proximal humeral outline shape: elliptical Fourier functions.
AB - A method is presented for the numerical analysis of sex differences in size and
shape of the proximal humeral outlines using elliptical Fourier functions (EFFs).
A skeletal sample consisting of right and left humeri pairs of 69 individuals, 36
males and 33 females, was used. The proximal superior view in the plane of the
proximo-distal axis of each humerus was photographed and then 54 boundary points
were located on the two-dimensional outline tracings. These points were digitized
and used to compute EFFs with 27 harmonics. From the EFFs, a set of expected
points on the proximal humeral outline was generated using the centroid as an
origin. Superimposition of the male and female outlines on this centroid provided
a detailed picture of the relative sex differences in size and shape with respect
to that center. The bounded area of the proximal humeral outline showed
statistically significant sex differences. Additionally, statistical results of
the amplitudes derived from the "area-standardized" EFFs and visual assessments
of the mean outline plots indicated significant sex differences in shape of the
proximal humeral outlines. Focusing on localized regional differences, the
greater tubercle was located more postero-medially and the lesser tubercle was
located more anteriorly in the males compared to the females. Sex determinations
from the proximal humeri were also examined with discriminant functions based on
the amplitudes, which represent shape characteristics of the outline, and the
hounded area. Using a cross-validation method, predictions of the percentages of
cases correctly classified with the discriminant functions were ranged from 92.8%
to 95.7% for the right and left humeral data. These results suggest that
differences in size and shape of the proximal humeral outlines may be better
predictors of sex when compared with conventional measurements of the humerus.
PMID- 10782950
TI - Age estimation by occlusal tooth wear.
AB - The purpose of the present investigation was to test the accuracy of a new
scoring system in recording tooth wear for age estimation. The material consisted
of dental stone casts of 383 volunteers who had sound premolars and molars with
normal occlusion. The degree of occlusal wear for all premolar and molar teeth
was scored with the new system. The high intra- and inter-examiner concordances
showed that the new score system was very reliable. The degree of tooth wear
showed a significant positive correlation with age in each and every examined
tooth of both males and females. Tooth wear scores of males were higher than
those of females. Calculating tables for age estimation were designed and the
accuracy of age estimation was obtained with the General Linear Models
procedures. Our system could provide estimation of an individual's age within +/
3 years in 42.4% of males and 49.4% of females, within +/-5 years in 61.8% of
males and 63.3% of females. When the subjects were divided into two age groups
and data were re-treated, the accuracy of age estimation was increased.
Collectively, it was shown that our new system for scoring tooth wear is a
reliable and accurate method for age estimation.
PMID- 10782951
TI - Secondary ion mass spectrometric characterization of nail polishes and paint
surfaces.
AB - A variety of paint and fingernail polish samples, which were visually similar,
but had different chemical compositions and formulations, was analyzed using
quadrupole static secondary ion mass spectrometry (SIMS). Coating distinction was
easily achieved in many cases because of the presence of dominant ions derived
from the components of the coating, which could be observed in the SIMS spectra.
In other instances, coating distinction was difficult within a product line
because of spectral complexity; for this reason and because of the large numbers
of spectra generated in this study, multivariate statistical techniques were
employed, which allowed the meaningful classification and comparison of spectra.
Partial Least Squares (PLS) and Principal Component Analysis (PCA) were applied
to quadrupole SIMS data. PCA showed distinct spectral differences between most
spectral groups, and also emphasized the reproducibility of the SIMS spectra.
When using PLS analysis, reasonably accurate coating identification was achieved
with the data. Overall, the PLS model is more than 90% effective in identifying
the spectrum of a particular coating, and nearly 100% effective at telling which
coating components represented in the PLS models are not present in a spectrum.
The level of spectral variation caused by sample bombardment in the SIMS analysis
was investigated using Fourier transform infrared spectroscopy (FT-IR) and
quadrupole static SIMS. Changes in the FT-IR spectra were observed and were most
likely a result of a number of factors involving the static SIMS analysis.
However, the bulk of the sample is unaltered and may be used for further testing.
PMID- 10782952
TI - Physical and chemical evidence remaining after the explosion of large improvised
bombs. Part 1: firings of ammonium nitrate/sugar and urea nitrate.
AB - Recent criminal acts in the United Kingdom, United States and other countries
have demonstrated the dangers to public safety from the criminal use of
improvised explosives on a large scale. Four sets of trials were carried out over
four years, partly in collaboration with the United States Federal Bureau of
Investigation, involving the firing of large bombs, mostly fertilizer based. The
principal objectives of the firings were to measure the physical effects of the
explosions upon objects representative of those that would be found at a real
bomb scene and to recover any chemical traces deposited on these objects. The
results are intended for use as an aid in determining the approximate size and
type of an explosive employed in a terrorist attack. This paper describes the
background behind the trials, the procedures for preparation of witness materials
and charges, and the collection and analysis of physical and chemical evidence.
PMID- 10782953
TI - Physical and chemical evidence remaining after the explosion of large improvised
bombs. Part 2: Firings of calcium ammonium nitrate/sugar mixtures.
AB - Six test firings of large improvised explosive devices were carried out. The
principal objectives of the firings were to measure the physical effects of the
explosions upon representative objects placed nearby and to recover any chemical
traces deposited on these objects. The results are intended for use as an aid in
determining the approximate size and type of an explosive employed in terrorist
attacks. Three 454 kg charges of a mixture of calcium ammonium nitrate (CAN)
fertilizer and sugar, and three 2268 kg charges of a similar mixture, all
confined in cylindrical steel containers were fired. Each charge was surrounded
by 19 road signs mounted on posts and four vehicles, to act as witness materials.
The analysis of aqueous swab extracts taken from the witness materials after
firing showed the recovery of nitrate, ammonium and low levels of glucose. No
sucrose was detected. Nitrate was usually recovered in greater quantities than
ammonium and recovery generally decreased with increasing distance from the
charges in any given direction. Quantities recovered from objects placed at the
same distance in different directions varied considerably. Patterns of physical
damage to the witness materials could be discerned according to their distance
from the charge and the size of the charge. The velocities of detonation and air
blast effects were measured.
PMID- 10782956
TI - The role of the dental hygienist in mass disasters.
AB - The authors examine the specialty of dental hygiene and address its role in the
identification of mass-disaster fatalities. Very little exists in the literature
on what dental hygienists can often and what they have contributed as members of
dental-identification teams. To encourage forensic dentists to seek out the
valuable assistance of these highly trained professionals, the authors illustrate
how their services can be used in mass disasters.
PMID- 10782955
TI - Fingerprint enhancement revisited and the effects of blood enhancement chemicals
on subsequent profiler Plus fluorescent short tandem repeat DNA analysis of fresh
and aged bloody fingerprints.
AB - This study was aimed at determining the effect of seven blood enhancement
reagents on the subsequent Profiler Plus fluorescent STR DNA analysis of fresh or
aged bloody fingerprints deposited on various porous and nonporous surfaces.
Amido Black, Crowle's Double Stain. 1,8-diazafluoren-9-one (DFO), Hungarian Red,
leucomalachite green, luminol and ninhydrin were tested on linoleum, glass,
metal, wood (pine, painted white), clothing (85% polyester/15% cotton, 65%
polyester/35% cotton, and blue denim) and paper (Scott 2-ply and Xerox-grade).
Preliminary experiments were designed to determine the optimal blood dilutions to
use to ensure a DNA typing result following chemical enhancement. A 1:200 blood
dilution deposited on linoleum and enhanced with Crowle's Double Stain generated
enough DNA for one to two rounds of Profiler Plus PCR amplification. A
comparative study of the DNA yields before and after treatment indicated that the
quantity of DNA recovered from bloody fingerprints following enhancement was
reduced by a factor of 2 to 12. Such a reduction in the DNA yields could
potentially compromise DNA typing analysis in the case of small stains. The blood
enhancement chemicals selected were also evaluated for their capability to reveal
bloodmarks on the various porous and nonporous surfaces chosen in this study.
Luminol. Amido Black and Crowle's Double Stain showed the highest sensitivity of
all seven chemicals tested and revealed highly diluted (1:200) bloody
fingerprints. Both luminol and Amido Black produced excellent results on both
porous and nonporous surfaces, but Crowle's Double Stain failed to produce any
results on porous substrates. Hungarian Red, DFO, leucomalachite green and
ninhydrin showed lower sensitivities. Enhancement of bloodmarks using any of the
chemicals selected, and short-term exposure to these same chemicals (i.e., less
than 54 days), had no adverse effects on the PCR amplification of the nine STR
systems surveyed (D3S 1358, HumvWA, HumFGA, D8S1179, D21S11, D18S51, D5S818,
D13S317, D7S820) or of the gender determination marker Amelogenin. The intensity
of the fluorescent signals was very similar and the allele size measurements
remained constant and identical to those of untreated bloody fingerprints. No
additional background fluorescence was noted. Continuous exposure (for 54 days)
to two of the seven enhancement chemicals selected (i.e., Crowle's Double Stain
and Hungarian Red) slightly reduced the amplification efficiency of the longer
STR loci in profiles of fresh and 7 to 14-day-old bloodprints. This suggests that
long-term exposure to these chemicals possibly affects the integrity of the DNA
molecules. This study indicates that significant evidence can be obtained from
fresh or aged bloody fingerprints applied to a variety of absorbent and
nonabsorbent surfaces which are exposed to different enhancement chemicals for
short or long periods of time. It also reaffirms that PCR STR DNA typing
procedures are robust and provide excellent results when used in concert with
fluorescence-based detection assays after fingerprint identification has taken
place.
PMID- 10782954
TI - The relationship between substance use, drug selling, and lethal violence in 25
juvenile murderers.
AB - The goal of the present study was to determine the relationship between substance
use, drug selling, and lethal violence in adolescent male homicide offenders and
their victims. The study employed a retrospective review of criminal justice
databases and medical examiner records for murders committed by 25 adolescent
males incarcerated in the Commonwealth of Virginia juvenile correctional centers
from February 1992 to July 1996. The perpetrator sample was 84% African American
and 16% white. The average age at the time of the offense was 15.0 years (range =
13.0 to 17.7 years). The victims were 84% male, 60% African American and 32%
white. The median victim age was 28.0 years (mean = 34.8, range = 17 months to 75
years). The results indicated that 52% of the murders were committed by juveniles
with identified involvement in drug selling, and 28% of the murders were drug
related. Toxicology results indicated recent drug or alcohol use in 27% of the
victims; while 74% of the perpetrators reported substance use, 35% indicating
daily use. Using discriminant analysis, it was possible to accurately classify
86% of the drug-related murders with the variables of recent victim drug use and
perpetrator substance use history. The results indicated that adolescent males
involved in the sale and distribution of illegal drugs comprised a significant
percentage of those incarcerated for murder. Recent victim drug use and
perpetrator substance use may be important variables in identifying drug-related
juvenile homicides. These results underscore the link between substance use, drug
selling, and lethal violence.
PMID- 10782957
TI - Clinical and forensic indicators of "suicide by cop".
AB - This paper reviews the literature pertaining to the phenomenon of "suicide by
cop"--any incident in which a suicidal individual attempts to get law enforcement
to kill him. This article defines the term "suicide by cop," discusses the
various motivations of individuals who engage in this type of behavior, presents
the risk factors and indicators for suicide and violence, and describes specific
indicators for suicide by cop. Proper recognition of these events, prior and
subsequent to their occurrence, has important implications for prevention,
officer safety, equivocal death analysis and psychological autopsy, civil
litigation, criminal justice proceedings, and community stability. This paper
presents seven case studies which demonstrate the clinical and forensic
indicators of this phenomenon.
PMID- 10782959
TI - A review of crane deaths in Jefferson County, Alabama.
AB - Cranes are machines used to move heavy objects. Cranes are operated by crane
operators, usually working in conjunction with an assistant guiding the movements
of the crane from his vantage point outside the crane. Few jurisdictions require
that crane operators be either licensed or certified. We conducted a
retrospective study of those dying of crane-related injuries in our jurisdiction
during the 16 years from 1981 to 1996. All ten decedents were male, and the
manner of each death was accidental. Neither ethanol nor drugs of abuse were
detected in any case. Eight of the ten decedents died due to blunt force
injuries, one due to mechanical asphyxia, and one due to thermal burns.
Investigation by the Occupational Safety and Health Administration (OSHA) led to
fines ranging from $80 to $2700 in six of the ten cases. Nationwide,
electrocution is the most common cause of crane-related death, but no crane
related death in Jefferson County was caused by electrocution in our study. The
absence of electrocutions was due to the planned, routine suspension of power to
electrical lines in the vicinity of a crane during the crane's operation, a
practice saving an estimated seven lives. Nevertheless, human error or lack of
planning was still responsible for most of the deaths in our study. In addition
to careful planning and adherence to safety standards established by planning, we
recommend the mandatory licensure and certification of professional crane
operators and the assessment of larger fines by OSHA for safety standard
violations.
PMID- 10782958
TI - Aging and homicide rates.
AB - There are no published studies concerning the effect of mortality rate on the
rate of homicide by habitually violent offenders. On the basis of nation-wide
statistics in Finland, the frequency of homicide is 61% lower among 50-year old
males than among 30-year old males. However, when the 4.9-fold mortality of
habitually violent offenders is taken into account, the homicide rate is only 43%
lower among 50-year old males than among 30-year old males. This is an important
issue in forensic psychiatry and that requires further attention, as age is used
a predictive factor when assessing the risk of violent behavior.
PMID- 10782960
TI - A 36-year history of fatal road rage in Marion County, Oregon: 1963-1998.
AB - This paper documents the 36-year history, with five examples, of fatal road rage
in Marion County, Oregon. Relevant details (all that were available) from each
case are presented. Alcohol intoxication was present in four of our five cases.
We include two deaths by gunshot at close range, two deaths as a result of a
motor vehicle traffic accident, and one natural death. All subjects were males.
Three were Caucasian and two were Hispanic. The three subjects in Cases 1, 2 and
3 were complete strangers to the occupants of the other involved vehicles. The
subjects in Cases 4 and 5 (along with the occupants of their own vehicles) were
acquaintances of the occupants of the involved vehicle. There appears to be no
previous forensic, medical or psychiatric literature on road rage as such. We
present an initial psychiatric evaluation of the perpetrators of this type of
fatal assault. There are no specific statutes in Oregon, at the state or county
levels, regarding road rage. However, the city of Gresham, Oregon, recently
enacted an ordinance regarding road rage. We stress the need for further study of
this phenomenon, especially through the use of the psychological-psychiatric
autopsy.
PMID- 10782961
TI - Hair analysis: self-reported use of "speed" and "ecstasy" compared with
laboratory findings.
AB - Drug use histories were collected from 100 subjects recruited from the "dance
scene" in and around Glasgow, Scotland. In addition, each subject donated a hair
sample which was analyzed by gas chromatography/mass spectrometry (GC/MS) for
amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4
methylenedioxymethamphetamine (MD MA) and 3,4-methylenedioxyethylamphetamine
(MDEA). The hair samples were analyzed in two 6 cm segments or in full, ranging
from 1.5 to 12 cm depending on the length of the hair. Approximately 10 mg of
hair was ground to a fine powder before treatment with beta-glucuronidase/aryl
sulfatase. A solid-phase extraction procedure was carried out followed by
derivatization with pentafluoropropionic anhydride (PFPA). All extracts were
analyzed by gas chromatography/mass spectrometry (GC/MS). Of the 139 segments
analyzed, 77 (52.5%) were positive for at least one of the five amphetamines. The
drug concentrations found in the hair were compared with the self-reported drug
histories. A concordance of greater than 50% was found between the self-report
data and levels detected in hair. However, no correlation was found between the
reported number of "ecstasy" tablets consumed and the drug levels detected in
hair. An increase in the average drug levels measured was observed from low to
high use (number of "ecstasy" tablets/month). A large number of false negatives
and a low number of false positives were observed.
PMID- 10782963
TI - Solid-phase extraction for profiling of ecstasy tablets.
AB - A solid-phase extraction (SPE) procedure has been developed for impurity
profiling of illicit tablets containing 3,4-methylenedioxy-N-methyl-amphetamine
(MDMA, ecstasy). Following initial comparison of liquid-liquid extraction and
solid-phase extraction, SPE was found to be preferable because it afforded higher
extraction efficiencies and shorter extraction times. Procedure blank samples
were also analyzed to identify constituents of the extracts which did not
originate in the ecstasy tablets. The developed procedure was subsequently
applied to 12 samples of seized ecstasy tablets and a comparison was made of
these samples to determine similarities and obtain inferences with respect to
commonality of origin.
PMID- 10782962
TI - Analysis of morphine by RIA and HPLC in fingernail clippings obtained from heroin
users.
AB - Heroin is abused around the world and is frequently reported as the cause of
death in overdose cases. Analysis of morphine in hair has been used in the past
in forensic toxicology to study the addiction history of heroin addicts. The
purpose of the present study was to evaluate the usefulness of the nail as an
analytical specimen in the identification and quantification of morphine in
fingernail clippings of known heroin users. Fingernail clippings were obtained
from 26 consenting patients of the Glasgow Drug Problem Service. At the time of
sampling, the participants provided answers to a questionnaire regarding their
drug use patterns. Samples were decontaminated by sonication in SDS, deionized
water and methanol, and the methanolic washes were screened for analyte presence.
The washed nail clippings were then hydrolyzed and extracted. RIA was used for
the screening and HPLC for the confirmation of morphine. Positive RIA results
were obtained with nail clippings from 25 of the 26 heroin users. The levels
ranged from 0.06 to 4.69 ng/mg with a mean morphine concentration of 1.67 ng/mg.
HPLC results were positive for 22 of the 26 nail samples. The mean morphine level
by HPLC was 2.11 ng/mg with a range from 0.14 to 6.90 ng/mg. Based on these
results, we suggest that nails have the potential of becoming a powerful
alternative to hair for the detection of past heroin use in forensic cases.
PMID- 10782965
TI - The FAA's postmortem forensic toxicology self-evaluated proficiency test program:
the first seven years.
AB - Existing proficiency-testing (PT) programs do not address the complexity of
postmortem forensic toxicology. These programs do not include decomposed samples
and solid tissues. Therefore, the Federal Aviation Administration in July 1991
started such a needed PT program. This program is used to: (i) professionally
develop and maintain technical currency on a voluntary, interlaboratory, and self
evaluation basis, and (ii) quantifiably assess methods in the absence and
presence of interfering substances. There are currently about 30 laboratories in
the program. Functioning under various governmental/non-governmental agencies and
academic institutions, these laboratories represent a broad cross-section of the
country. PT samples are distributed quarterly, and result summaries are sent to
the participants, while maintaining their anonymity. Since the inception of the
program, 28 PT samples encompassing whole blood, plasma, urine, kidney, or liver,
with (or without) drugs, metabolites, and common chemicals (nicotine, caffeine,
beta-phenylethylamine, etc.) have been analyzed by the participants. Analytical
findings were generally consistent with the anticipated values, but they were
dependent on the nature and conditions of the specimens and types of the added
analytes. Some incidences of false positives of concern were noted, as well. This
PT program is one of the few programs recommended by the American Board of
Forensic Toxicology in which laboratories may participate for their accreditation
by the Board. It is anticipated that this PT program will continue to play a
critical part in supporting the quality assurance/quality control (QA/QC)
component of forensic toxicology, thereby enhancing operational performance.
PMID- 10782964
TI - Olanzapine concentrations in clinical serum and postmortem blood specimens--when
does therapeutic become toxic?
AB - The concentration of olanzapine (Zyprexa) was determined in 1653 clinical serum
specimens during routine drug monitoring, and in 58 postmortem whole blood
specimens as part of routine toxicological analysis. The analysis of olanzapine
was performed by the solid-phase extraction of 1.0 mL of buffered serum or blood,
followed by gas chromatography separation with nitrogen-phosphorus detection. The
analysis of the clinical serum samples showed that 86% of positive serum values
were within the range of 5 to 75 ng/mL, with a mean and median of 36 and 26
ng/mL, respectively. These data suggest that the concentrations of olanzapine
expected during therapy may be higher than those previously reported. In 58
postmortem whole blood specimens the mean olanzapine concentration was 358 ng/mL
with a range of 10 to 5200 ng/mL. Further, investigation of deaths involving
olanzapine suggest that potential toxicity should be considered at concentrations
above 100 ng/mL. Although the majority of the olanzapine-related deaths were
associated with many other drugs, death primarily due to olanzapine toxicity was
determined at concentrations in post-mortem blood as low as 160 ng/mL.
PMID- 10782966
TI - Population frequency for the short tandem repeat loci D18S849, D3S1744, and
D12S1090 in Caucasian-Mestizo and African descent populations of Colombia.
AB - Blood samples from 489 unrelated Caucasian Mestizo and 252 individuals of African
descent in Colombia were amplified and typed for three short tandem repeat (STR)
markers (D12S1090, D3S1744, and D18S849). All markers conformed to Hardy-Weinberg
equilibrium expectations in both populations studied. In addition,
heterozygosity, mean exclusion chance, polymorphism information content,
discrimination power, and the assumption of independence within and between loci
were determined. The mean exclusion chance for all three STR markers is 0.9750 in
the Caucasian Mestizo population and 0.9731 in the African Colombian Population.
The discrimination power is 0.999925 and 0.999911 in the Caucasian Mestizo and
African Colombian respectively.
PMID- 10782968
TI - Swiss allele frequencies and haplotypes of 7 Y-specific STRs.
AB - In view of application to personal identification and paternal analysis, the
allele distribution of the loci DYS 19, DYS389 I and II, DYS390, DYS391, DYS392,
and DYS393 were determined in a sample of 126 unrelated males from the area of
Bern (Switzerland). The 7 Y-STR loci were coamplified in a total of two multiplex
reactions using fluorescently-labeled primers. PCR products were separated and
detected on a capillary electrophoresis ABI Prism 310 instrument. All loci were
polymorphic and the allele distributions are similar to other caucasian data.
PMID- 10782967
TI - Population genetics of nine STR loci in two populations from Brazil.
AB - The Short Tandem Repeats (STRs) D3S1358, HUMvWA31/A, HUMFIBRA/FGA, D8S 1179,
D2S11, D18S51, D5S818, D13S317, and D7S820 were studied in two Brazilian
populations (from Amazonia and S. Paulo) using the "AmpF1 STR Profiler Plus PCR
Amplification Kit." The nine loci showed a combined discrimination power greater
than 0.9999999999 and a chance of exclusion of 0.9999.
PMID- 10782969
TI - The distribution of D1S80 and VWA alleles in a Karen population from Northern
Thailand.
AB - The DIS80 and VWA loci were studied in a Karen population from Northern Thailand
by the polymerase chain reaction and polyacrylamide gel electrophoresis. Twelve
DIS80 and six VWA alleles were found. No deviations from the Hardy-Weinberg and
linkage equilibrium were observed. The power of exclusion (PE) from the analysis
of the DIS80 and VWA locus is 0.67 and 0.45, respectively, the power of
discrimination (PD) is 0.95 and 0.85, respectively, with a combined PD of 0.99
and PE of 0.82.
PMID- 10782970
TI - Population genetics of the D1S1656, D12S391, and D18S535 loci in Asturias (North
Spain).
AB - Allele and genotype frequencies for three recently described short tandem repeat
loci D1S1656, D12S391, and D18S535 were determined in a population sample from
Asturias (North Spain). The loci were amplified using a fluorescence based PCR
method and were typed automatically. No deviation from Hardy-Weinberg
expectations were observed. The three loci proved to be highly discriminating and
the allele frequencies observed are similar to those of the other European
populations that have been typed for these loci to date.
PMID- 10782971
TI - Threat mail and forensic science: DNA profiling from items of evidence after
treatment with DFO.
AB - Two cases of threatening letters with their accompanying envelopes were received
to the Division of Forensic Identification unit of the Israel Police. The
envelopes, including the stamps, and the letters were initially examined for
latent fingerprints by the DFO reagent, known to cause degradation of DNA.
Although no latent fingerprints could be visualized on any of the items, the
biology laboratory using organic DNA extraction, was successful in defining
genetic profiles from all the items employing six STR loci, even after treatment
with DFO. In a controlled experiment, a known donor attached a stamp, by licking,
to an envelope. This item was treated with DFO and then profiled using STR loci.
The results showed that previous DFO treatment on the control stamp before DNA
analysis had no negative effects on obtaining the DNA profile of the known donor
using STR loci.
PMID- 10782972
TI - Analysis of primer residue from lead free ammunition by X-ray microfluorescence.
AB - In forensic science, the analysis of gunshot residues was traditionally done by
the detection of lead (Pb), antimony (Sb) and barium (Ba) usually found in a
primer. However, the recent development of lead-free ammunition represents a new
challenge for ballistic specialists. This analysis study gunshot residues from
primers and ammunitions in the area surrounding bullet holes, a very important
tool to determine the shooting distance. The ammunitions used were 9 mm Luger and
.38 spl + p calibers, where lead in the primer was replaced with strontium (Sr)
and where the lead bullet was plated with copper (Total Metal Jacket). Gunshot
analysis results were obtained using an energy dispersive X-ray microfluorescence
spectrometer. The method allows the detection and quantification of strontium
residues on the target up to a distance of 45 cm.
PMID- 10782973
TI - The detection and analysis of ignitable liquid residues extracted from human skin
using SPME/GC.
AB - A simple, fast, inexpensive, and sensitive technique for the detection and
identification of flammable or combustible liquid residues on the skin of arson
suspects is presented. The use of solid phase microextraction (SPME) for the
analysis of ignitable liquid residues has been demonstrated and it is shown in
this work that this technique is effective in extracting these liquid residues at
extremely low quantities. Microliter quantities of controlled spikes of gasoline,
diesel fuel, and charcoal lighter fluid were deposited on the hands of a
volunteer and extracted after several time intervals. The SPME technique can
recover very small amounts of liquid deposits on skin up to 3.5 h after exposure,
depending on the class of the ignitable liquid residue used.
PMID- 10782974
TI - Sex variation in the second cervical vertebra.
AB - The second cervical vertebra can be used to estimate sex with 83% accuracy in
unidentified human skeletal remains. Reported here are the necessary statistics,
based on 8 dimensions taken from 400 second cervical vertebrae, for the
computation of customized discriminant functions. Discriminant function equations
developed using variables selected in a stepwise procedure are also presented
here as an example of the usefulness of this bone in estimating sex.
PMID- 10782975
TI - Use of radiographic atlases in a mass fatality.
AB - In May and June of 1996, a forensic anthropology team from the C.A. Pound Human
Identification Laboratory at the University of Florida identified 9 of 10
juveniles from the crash of ValuJet 592. The team relied primarily on a
radiographic atlas developed and used by clinical practitioners to determine
skeletal age. Postmortem radiographs of the juvenile victims were compared with
radiographic standards to determine skeletal age. Skeletal age was then compared
to a passenger list indicating the sex, weight, height, and chronological age of
each individual. Tentative identifications based on the atlas method were
organized into an exclusion matrix. Final identifications were based on this
assessment in conjunction with other anthropological data such as appearance and
fusion of ossification centers and estimation of stature.
PMID- 10782976
TI - The chain saw: an uncommon means of committing suicide.
AB - A suicide committed with a power saw is an uncommonly reported incident: and the
use of a chain saw in particular has been extremely rare. We report two cases of
suicide that were committed by using chain saws. In each case the victim had a
history of depression or of a prior suicide attempt, and applied the chain saw to
his neck to kill himself. We summarize the findings of the two death
investigations and the world literature pertaining to suicide committed with
power saws.
PMID- 10782977
TI - A fatal case of chlorate poisoning: confirmation by ion chromatography of body
fluids.
AB - A 49-year-old male chemical industry worker was admitted to intensive care with a
24-hour history of respiratory failure, vomiting, headache, stupor, arterial
hypotension, and cyanosed face and limbs. He had acute haemolysis (3.9 g/L plasma
haemoglobin concentration) and 30% methaemoglobinaemia. Whereas the search for
alcohol, barbiturates and opiates was negative, benzodiazepines and tricyclic
antidepressants were present. The patient was in fact being treated with
fluvoxamine, amitryptiline, and alprazolam. As the clinical and biological signs
suggested chlorate poisoning, chlorate was looked for by using an aniline color
reaction. It was found in gastric content and urine. Treatment consisted in
mechanical ventilation, vasoactive amines, methylene blue, plasma exchange,
exchange transfusion, and haemodialysis. Despite this, the patient had several
cardiac arrests and refractory metabolic acidosis. He died 12 h after his
admission. Specific ion chromatography was used afterhand to assay the chlorate
in various body fluids. The technique was based on a separation on an ion
exchange Dionex AS 12A column coupled with conductivity detection. A quantitative
estimation was carried out by using external calibration with a four-point
calibration curve which was linear between 1 and 15 mg/L. The measured plasma
levels of chlorate were 78 and 29 mg/L respectively before and after exchange
transfusion. Gastric-lavage liquid contained 1300 mg/L of chlorate and urine 4300
mg/L. Ion chromatography, which is routinely used in environmental studies helped
to confirm a massive oral intake of chlorate by measuring the corresponding blood
and urine chlorate concentrations, data which had only rarely been reported
previously.
PMID- 10782979
TI - Keyhole defect production in tubular bone.
AB - Fracture characteristics, reported primarily for the cranium, are valuable
indicators of bullet direction. A bullet striking the vault tangentially produces
an irregular opening, termed a "keyhole defect." with the circular portion of the
defect being the initial point of impact. Identifying this feature in tubular
bone (long bone) can also demonstrate bullet direction and the position of the
bone at the time of the shooting. This case study involving a tangential shot
(i.e., a keyhole fracture) to the humerus demonstrates some of the same fracture
mechanics seen in the cranium.
PMID- 10782978
TI - Fatal aspiration of sardine fry in a patient with lung cancer.
AB - We report a fatal case of death due to unusual aspiration of sardine fry in an
elderly Japanese man with lung cancer. The cause of death was sudden respiratory
arrest while eating. Autopsy revealed peculiar materials with cell nests and
pigmented particles, together with striated muscle and skin, in the ectatic
bronchioles of the left lower lobe. Serial histologic sections suggested that the
structures observed were the eyeballs of small animals that appeared to have been
inhaled. The patient had habitually eaten sardine fry and rice gruel, which were
also detected in the gastric contents. Therefore, the eyes were considered to be
those of the fry, which is a popular food item in Japan. This was confirmed by
histologic examination of fry that were obtained commercially.
PMID- 10782980
TI - The postmortem fate of Pat Gregory: a disinterred Native American.
AB - In late June 1990, the Mono County Sheriffs Department in Bridgeport, CA
contacted the Physical Anthropology Human Identification Laboratory (PAHIL) at
California State University, Chico to seek assistance in the identification of a
recently discovered skull. To assist with possible identification, the cranium
received a classic physical anthropological/morphological analysis to suggest the
decedent's sex, age at death, ancestral affiliation, and uniqueness. It was
concluded the cranium was that of an older male, and someone with mixed ancestry,
probably Native American/White. Suggested uniquenesses were an eroded and greasy
texture, with adhering white sand, evidence of healed antemortem nasal fractures,
and a bifid left occipital condyle. The cranium was confiscated from a man
suspected of vandalizing a Native American cemetery just south of the community
of Lee Vining. The cemetery was established in the mid-1800's by local Native
American tribes. Although ownership of the land was disputed by the US Forest
Service (the Inyo National Forest), and the Los Angeles Department of Water and
Power (LADWP), county authorities claimed that because the incident involved the
desecration of a cemetery and human remains, it was a legal issue, and therefore,
the Sheriff's Department had jurisdiction over the case if not the land. The
suspect pled guilty to the possession of Native American remains but claimed not
to have desecrated a grave. Over the next year and a half, members of the Native
American community representing various tribes sought the return of the cranium,
while also seeking assurance that it belonged to the vandalized grave. While
county, US Forest Service, and LADWP officials continued to argue over whom had
jurisdiction of the remains the superior court judge ordered the county to pay
for any analysis necessary to determine if the cranium belonged to the decedent
in question. This report addresses the conclusions of that analysis and the
disposition of the case. Furthermore, the report addresses the forensic value to
Native Americans of the continued study of a wide variety of human skeletal
remains.
PMID- 10782981
TI - The use of microscopic postmortem changes in anagen hair roots to associate
questioned hairs with known hairs and reconstruct events in two murder cases.
AB - In two cases investigated by the New Orleans Police Department Crime Lab, hairs
recovered from crime scenes were found to exhibit microscopic postmortem changes
in anagen hair roots. These microscopic characteristics were used to associate
these hairs with various victims in the cases. In addition to associating
questioned hairs with known hairs, the fact that the victims were dead when the
hairs were pulled helped investigators reconstruct events in both crimes and
corroborate statements made by the arrested subjects in each case.
PMID- 10782982
TI - Signature murders: a report of the 1984 Cranbrook, British Columbia cases.
AB - Two females, Denean Worms and Brenda Hughes, were murdered in separate events in
Cranbrook, British Columbia in 1984 within three months of each other. Terrence
Wayne Burlingham was found guilty of both murders and he appealed. The Supreme
Court of Canada granted Burlingham a new trial in the Worms case, but no evidence
from Burlingham's confession nor the murder weapon could be used. The Crown
counsel requested an evaluation of the two murders to determine if they were
committed by the same person. The analyses of those murders revealed that they
were linked by a personal "signature" of the killer. The murder cases reported
here demonstrate a control-oriented signature. The killer used a .410 shotgun as
his method of control and death, engaged in overkill of each victim by shooting
them twice in the head, and left the victims in sexually degrading positions.
Another signature feature was the absence of typical wounds to the victims which
would be expected from a serial sex offender. All of these characteristics, in
combination, accounted for this killer's personal expression.
PMID- 10782983
TI - Han Chinese population data in Chongqing China for nine STR loci.
PMID- 10782984
TI - Increasing the identification potential from human foot remains.
PMID- 10782986
TI - Commentary on Wu AHB, Hill DW, Crouch D, Hodnett CN, McCurdy HH. Minimal
standards for the performance and interpretation of toxicology tests in legal
proceedings. J Forensic Sci 1999;44(3):516-522.
PMID- 10782987
TI - Commentary on Keto RO. Analysis and comparison of bullet leads by inductively
coupled plasma mass spectrometry. J Forensic Sci 1999;44(5):1020-6.
PMID- 10782985
TI - Practical implications of charge transport model for electrostatic detection
apparatus (ESDA).
PMID- 10782988
TI - Verbal conventions for handwriting opinions.
PMID- 10782989
TI - Interaction of E. coli single-stranded DNA binding protein (SSB) with exonuclease
I. The carboxy-terminus of SSB is the recognition site for the nuclease.
AB - The 3'-5' single-stranded DNA(ssDNA) degrading exonuclease I of E. coli directly
interacts with the E. coli ssDNA binding protein (EcoSSB). Analytical
ultracentrifugation shows that all 4 carboxy-termini of an EcoSSB tetramer bind
exonuclease I. Binding is weakened by increasing salt concentrations, indicating
the involvement of the negatively charged amino acids of the carboxy-terminus of
SSB. Mutant SSB proteins EcoSSBP176S (ssb-113) and EcoSSBF177C do not
bindtoexonuclease I while EcoSSBG15D (ssb-3) does bind. In a co-precipitation
assay we show that the absence of the lastten amino acids (PMDFDDDIPF) completely
abolishes binding of EcoSSB to exonuclease I. The interaction does not depend on
the presence of the correct amino-terminal DNA binding domain or the amino acid
sequences between the DNA binding domain and the last ten amino acids. A
synthetic peptide (WMDFDDDIPF), corresponding to the last nine amino acids of
EcoSSB, specifically inhibits the interaction. Both EcoSSBP176S and EcoSSBF177C
SSBs bind DNA similar to wild-type EcoSSB, indicating that the phenotype of ssb
113 is not an indication of altered DNA binding. The repair deficiency of either
ssb-3 or ssb-113 strain can be complemented by overexpression of the respective
other mutant.
PMID- 10782990
TI - p38/SAPK2-dependent gene expression in Jurkat T cells.
AB - The stress-activated protein kinase p38/SAPK2 is known to regulate the activity
of transcription factors and to control expression of several genes at the
transcriptional or post-transcriptional level. In order to identify genes whose
expression is under the control of p38/SAPK2 activity, we have compared the mRNA
levels of a pattern of 588 genes between human Jurkat T cells with anisomycin
activated p38/SAPK2 and cells in which p38/SAPK2 was inhibited by the compound
SB203580. Genes strongly expressed at the transcript level as a result of
p38/SAPK2 activation are the transcription factors c-jun, fos-related antigen 1
(fra-1), the growth-arrest and DNA-damage gene gadd153 and early-growth-related
gene 1 (egr-1) as well as the c-srk kinase csk and the nucleotide exchange factor
ras-GRF. mRNAs significantly down-regulated include the insulin receptor IR, the
adapter grb2, the transcription factor c-myc and the defender against apoptotic
death, dad-1. For six selected genes, p38/SAPK2-regulated expression was
confirmed and further analysed by Northern blot experiments, demonstrating a
complex regulation of these genes under stress conditions.
PMID- 10782993
TI - Structural investigations of the highly flexible recombinant ribosomal protein
L12 from Thermotoga maritima.
AB - Ribosomal protein L7/L12, the only multicopy component of the ribosome, is
involved in translation factor binding and in the ribosomal GTPase center. The
gene for L7/L12 from Thermotoga maritima was cloned and the protein expressed at
high levels in Escherichia coli. Purification of L7/L12 was achieved under non
denaturing conditions via heat treatment and two chromatographic steps. Circular
dichroism melting profiles were monitored at 222 nm, showing the melting
temperature of the protein at pH 7.5 around 110 degrees C, compared to
approximately 60 degrees C for the highly homologous Escherichia coli protein.
The unfolding was reversible and renaturation closely followed the path of the
thermal melting. Dynamic light scattering, gel filtration chromatography, and
crosslinking experiments suggested that under physiological buffer conditions
Thermotoga maritima L7/L12 exists as a tetramer. The protein was crystallized
under two conditions, yielding an orthorhombic (C222(1)) and a cubic (12(1)3)
space group with an estimated two and three to four L7/L12 molecules per
asymmetric unit, respectively. The crystals contained the full-length protein,
and cryogenic buffers were developed which improved the mosaic spreads and the
resolution limits. For the structure solution isoleucine was mutated to
methionine at two separate positions, the mutant forms expressed as
selenomethionine variants and crystallized.
PMID- 10782991
TI - The first laminin G-type domain in the SHBG-like region of protein S contains
residues essential for activation of the receptor tyrosine kinase sky.
AB - Vitamin K-dependent protein S and the product of growth-arrest-specific gene 6
(Gas6) both possess the ability to phosphorylate members of the Axl/Sky subfamily
of receptor tyrosine kinases. However, Gas6 appears to be the bona fide ligand
for these receptors in man, as human protein S has been demonstrated to activate
murine Sky but not the human orthologue. In contrast, bovine protein S is able to
stimulate human Sky despite its high degree of sequence identity with human
protein S. The domain organisations of protein S and Gas6 are virtually identical
and the C-terminal SHBG-like region, containing two globular (G) domains, has
been shown to play a crucial role in the receptor stimulation. In order to
further localise the area responsible for the interaction, a number of protein
chimeras were used to stimulate human Sky. Each chimera had one part of the human
protein S SHBG-like region replaced by the corresponding part of bovine protein S
or human Gas6. We found that human protein S may indeed activate human Sky but
only above physiological plasma concentrations. The human-bovine protein S
chimeras provided new information implying that the first G domain contains
critical residues for the interaction with the Sky receptor. Moreover, these
residues do not seem to be clustered but rather to be distributed at various
positions in the first G domain.
PMID- 10782996
TI - Stability of bacteriophage T4 short tail fiber.
AB - Adsorption of T-even bacteriophages to the E. coli host cell is mediated by long
and short tail fibers. Bacteriophage T4 short tail fiber protein p12 was used to
investigate the stability against thermal and chemical denaturation. Purified p12
is thermostable with a melting point of 78 degrees C. Guanidinium chloride
induced denaturation displayed strong hysteresis and an intermediate between 2
and 3 M denaturant. The transitions occur at 1.5 and 3.2 M denaturant as revealed
by fluorescence spectroscopy and circular dichroism. The data suggest an
equilibrium unfolding intermediate with a separate unfolding of the C-terminal
knob domain and the shaft region.
PMID- 10782994
TI - Polyhistidine-tagged hepatitis B core particles as carriers of HIV-1/gp120
epitopes of different HIV-1 subtypes.
AB - The hepatitis B core antigen is a widely accepted carrier particle to enhance the
immunogenicity of foreign epitopes. From electron cryomicroscopy, the
immunodominant region between amino acid positions 79 to 81 is known to protrude
from the surface of the shells. It can be replaced by heterologous sequences
without interfering with the particle-forming capacity in many cases. Here we
have introduced various V3 sequences of the envelope protein of different
subtypes (A, B, O) of HIV-1/gp120 in order to enhance their immunogenicity and
broaden the immune response against the virus. To improve purification efficiency
and solubility of the E. coli-expressed hybrids, six histidine residues were
fused to amino acid 156. An adjustable purification scheme was utilised including
denaturation, Ni(2+)-NTA affinity chromatography and particle renaturation under
high salt conditions, resulting in highly pure antigen preparations. The hybrids
reacted specifically with sera of HIV-1-infected patients. They further induced
an autologous, subtype-specific anti-HIV-1 antibody response superior to that of
Keyhole limpet-haemocyanine-coupled peptides.
PMID- 10782992
TI - Permutation of the active site motif of tryparedoxin 2.
AB - Tryparedoxins (TXN) are thioredoxin-related proteins which, as
trypanothione:peroxiredoxin oxidoreductases, constitute the trypanothione
dependent antioxidant defense and may also serve as substrates for ribonucleotide
reductase in trypanosomatids. The active site motif of TXN2, 40WCPPCR45, of
Crithidia fasciculata was mutated by site-directed mutagenesis and eight
corresponding muteins were expressed in E. coli as terminally His-tagged
proteins, purified to homogeneity by nickel chelate chromatography, and
characterized in terms of specific activity, specificity and, if possible,
kinetics. Exchange of Cys41 and Cys44 by serine yielded inactive products
confirming their presumed involvement in catalysis. Exchange of Arg45 by
aspartate resulted in loss of activity, suggesting an activation of active site
cysteines by the positive charge of Arg45. Substitution of Trp40 by phenylalanine
or tyrosine resulted in moderate decrease of specific activity, as did exchange
of Pro42 by glycine. Kinetic analysis of these three muteins revealed that
primarilythe reaction with trypanothione is affected by the mutations. Simulation
of thioredoxin or glutaredoxin-like active sites in TXN2 (P42G and W40T/P43Y,
respectively) did not result in thioredoxin or glutaredoxin-like activities.
These data underscore that TXNs, although belonging to the thioredoxin
superfamily, represent a group of enzymes distinct from thioredoxins and
glutaredoxins in terms of specificity, and appear attractive as molecular targets
for the design of trypanocidal compounds.
PMID- 10782995
TI - 'In vitro evolution' of ligands for HCV-specific serum antibodies.
AB - We developed a strategy to improve the properties of ligands selected from phage
displayed random peptide libraries. A site-directed mutagenesis protocol that
introduces mutations and extends the size of a target sequence has been set up to
generate diversity in a single or in a population of clones. The pool of mutants
thus created is screened to identify variants with the desired properties. We
refer to this strategy as in vitro evolution' of ligands. Here we report the
application of this in vitro evolution protocol to the identification of improved
ligands for HCV-specific serum antibodies. A single clone or population of clones
were processed to generate a secondary library. Screening of these libraries with
sera from HCV-infected patients identified peptides with an enhanced and
broadened ability to detect HCV-specific serum antibodies.
PMID- 10782997
TI - Analysis of the RNase T1 mediated cleavage of an immobilized gapped heteroduplex
via fluorescence correlation spectroscopy.
AB - We report a new method for studying the activity of hydrolytic enzymes.
Fluorescence correlation spectroscopy was used to observe online the
hydrolyzation of a rhodamine B-labeled substrate by ribonuclease T1. A gapped
heteroduplex substrate - a hybrid of a ribooligonucleotide and two smaller
complementary deoxyribooligonucleotides - was immobilized via biotin to a
streptavidin-coated surface of a coverslip. The reported method opens the
possibility to study the cleavage of small substrates differing only slightly in
molecular weight from the enzyme reaction product. The use of fluorescence
correlation spectroscopy allows the detection of very low enzyme concentrations
(down to 10(-21) mol 0.05 fM of RNase T1, corresponding to about 600 RNase T1
molecules in 0.02 ml).
PMID- 10782998
TI - Binding of selenoprotein P to heparin: characterization with surface plasmon
resonance.
AB - The binding of selenoprotein P to glycosaminoglycans using heparin as a model
compound was studied by surface plasmon resonance. It was found that heparin
contains two binding sites for selenoprotein P, a high-affinity, low-capacity
site (Kd approximately 1 nM) and a low-affinity, high-capacity site (Kd
approximately 140 nM). Binding at both sites is sensitive to pH and ionic
strength, and the high-affinity site is abolished by histidine carbethoxylation
with diethylpyrocarbonate. The pH and salt dependence of binding suggests
electrostatic interactions with heparin. The concentrations of selenoprotein P in
plasma (approximately 50 nM) are sufficiently high to facilitate binding of
selenoprotein P to proteoglycans on the vascular endothelium, and this may
contribute to the formation of a protective barrier against oxidants such as
peroxynitrite or hydroperoxides.
PMID- 10782999
TI - Biotin-avidin microplate assay for the quantitative analysis of enzymatic
methylation of DNA by DNA methyltransferases.
AB - An assay is described to measure methylation of biotinylated oligonucleotide
substrates by DNA methyltransferases using [methyl-3H]-AdoMet. After the
methylation reaction the oligonucleotides are immobilized on an avidin-coated
microplate. The incorporation of [3H] into the DNA is quenched by addition of
unlabeled AdoMet to the binding buffer. Unreacted AdoMet and enzyme are removed
by washing. To release the radioactivity incorporated into the DNA, the wells are
incubated with a non-specific endonuclease and the radioactivity determined by
liquid scintillation counting. As an example, we have studied methylation of DNA
by the EcoRV DNA methyltransferase. The reaction progress curves measured with
this assay are linear with respect to time. Methylation rates linearly increase
with enzyme concentration. The rates are comparable to results obtained with the
same enzyme using a different assay. The biotin-avidin assay is inexpensive,
convenient, quantitative, fast and well suited to process many samples in
parallel. The accuracy of the assay is high, allowing to reproduce results within
+/- 10%. The assay is very sensitive as demonstrated by the detection of
incorporation of 0.8 fmol methyl groups into the DNA. Under the experimental
conditions, this corresponds to methylation of only 0.03% of all target sites of
the substrate. Using this assay, the DNA methylation activity of some M.EcoRV
variants could be detected that was not visible by other in vitro methylation
assays.
PMID- 10783000
TI - Biochemical modifications and transcriptional alterations attendant to sterol
feeding in Phytophthora parasitica.
AB - Phytophthora species are eukaryotic sterol auxotrophs that possess the ability to
grow, albeit poorly, in the complete absence of sterols. Growth of Phytophthora
is often improved substantially when an exogenous source of sterol is provided.
Additionally, sterols may be required for sexual and asexual sporulation in
Phytophthora. Our research has been focused on identifying and characterizing the
immediate physiological effects following sterol addition to cultures of P.
parasitica. Through gas chromatographic analysis of extracts from P. parasitica
cultures that were fed various sterols, we have obtained evidence for sterol C5
desaturase and delta7 reductase activities in this organism. Zoo blots were
probed with DNA sequences encoding these enzymes, from Saccharomyces cerevisiae
and Arabidopsis thaliana. Hybridization of a S. cerevisiae ERG3 probe to P.
parasitica DNA was observed, implicating sequence similarity between the sterol
C5 desaturase encoding genes. Differential display experiments, using RNA from P.
parasitica, have demonstrated a pattern of altered gene expression between
cultures grown in the presence and absence of sitosterol. Characterization of
sterol-related metabolic effects and sterol functions in Phytophthora should lead
to improved measures for control of this important group of plant pathogens.
PMID- 10783001
TI - Cloning and characterization of the Dictyostelium discoideum cycloartenol
synthase cDNA.
AB - Cycloartenol synthase converts oxidosqualene to cycloartenol, the first
carbocyclic intermediate en route to sterols in plants and many protists.
Presented here is the first cycloartenol synthase gene identified from a protist,
the cellular slime mold Dictyostelium discoideum. The cDNA encodes an 81-kDa
predicted protein 50-52% identical to known higher plant cycloartenol synthases
and 40-49% identical to known lanosterol synthases from fungi and mammals. The
encoded protein expressed in transgenic Saccharomyces cerevisiae converted
synthetic oxidosqualene to cycloartenol in vitro. This product was characterized
by 1H and 13C nuclear magnetic resonance and gas chromatography-mass
spectrometry. The predicted protein sequence diverges sufficiently from the known
cycloartenol synthase sequences to dramatically reduce the number of residues
that are candidates for the catalytic difference between cycloartenol and
lanosterol formation.
PMID- 10783002
TI - Cloning and sequencing of the Candida albicans C-4 sterol methyl oxidase gene
(ERG25) and expression of an ERG25 conditional lethal mutation in Saccharomyces
cerevisiae.
AB - The ERG25 gene encoding the Candida albicans C-4 sterol methyl oxidase was cloned
and sequenced by complementing a Saccharomyces cerevisiae erg25 mutant with a C.
albicans genomic library. The Erg25p is comprised of 308 amino acids and shows 65
and 38% homology to the enzymes from S. cerevisiae and Homo sapiens,
respectively. The protein contains three histidine clusters common to nonheme
iron-binding enzymes and an endoplasmic reticulum retrieval signal as do the
proteins from S. cerevisiae and humans. A temperature-sensitive (ts) conditional
lethal mutation of the C. albicans ERG25 was isolated and expressed in S.
cerevisiae. Sequence analysis of the ts mutant indicated an amino acid
substitution within the region of the protein encompassed by the histidine
clusters involved in iron binding. Results indicate that plasmid-borne
conditional lethal mutants of target genes have potential use in the rescue of
Candida mutations in genes that are essential for viability.
PMID- 10783003
TI - Plant sterol-C24-methyl transferases: different profiles of tobacco transformed
with SMT1 or SMT2.
AB - Higher plant cells contain a mixture of 24-desmethyl, 24-methyl(ene), and 24
ethyl(idene) sterols in given proportions according to species but also to cell
type. As a first step to investigate the function of such sterol compositions in
the physiology of a plant, we have illustrated in the present work the
coexistence of two distinct (S)-adenosyl-L-methionine sterol-C24
methyltransferases (SMT) in transgenic Nicotiana tabacum L. Indeed, modulation of
the expression of the tobacco gene SMT1-1, which encodes a cycloartenol-C24
methyltransferase, results in variations of the proportion of cycloartenol and a
concomitant effect on the proportion of 24-ethyl sterols. Overexpression in
tobacco of the Arabidopsis thaliana (L.) Heynh. gene SMT2-1 which encodes a 24
methylene lophenol-C24(1)-methyltransferase, results in a dramatic modification
of the ratio of 24-methyl cholesterol to sitosterol associated with a reduced
growth, a topic discussed in the present work.
PMID- 10783004
TI - Design and synthesis of new steroidal inhibitors of estrogen synthase
(aromatase).
AB - The estrogen synthase (aromatase) enzyme system is responsible for the
biosynthesis of estrogen hormones in human females. Estrogens are vital for
normal growth and development, but will promote the growth of certain breast
cancers. Approximately 30-50% of breast cancers are considered to be hormone
dependent. Consequently regulation of estrogen biosynthesis has advanced as a
potential therapeutic strategy. This has led to the development of active-site
inhibitors, which may have potential for the control of breast cancer. We have
recently prepared a number of new steroidal inhibitors that have been evaluated
as aromatase inhibitors. These include steroidal A/B-ring isoxazoles and a series
of A/B-ring pyrazoles with alkyl- and aryl-substituted nitrogen. In addition, we
have developed new chemical procedures for the synthesis of 6beta-hydroxy
steroids, which could be key intermediates in the preparation of C-19 inhibitors
of aromatase activity.
PMID- 10783005
TI - Biosynthesis of sterols and ecdysteroids in Ajuga hairy roots.
AB - Hairy roots of Ajuga reptans var. atropurpurea produce clerosterol, 22
dehydroclerosterol, and cholesterol as sterol constituents, and 20
hydroxyecdysone, cyasterone, isocyasterone, and 29-norcyasterone as ecdysteroid
constituents. To better understand the biosynthesis of these steroidal compounds,
we carried out feeding studies of variously 2H- and 13C-labeled sterol substrates
with Ajuga hairy roots. In this article, we review our studies in this field.
Feeding of labeled desmosterols, 24-methylenecholesterol, and 13C2-acetate
established the mechanism of the biosynthesis of the two C29-sterols and a newly
accumulated codisterol, including the metabolic correlation of C-26 and C-27
methyl groups. In Ajuga hairy roots, 3alpha-, 4alpha-, and 4beta-hydrogens of
cholesterol were all retained at their original positions after conversion into
20-hydroxyecdysone, in contrast to the observations in a fern and an insect.
Furthermore, the origin of 5beta-H of 20-hydroxyecdysone was found to be C-6
hydrogen of cholesterol exclusively, which is inconsistent with the results in
the fern and the insect. These data strongly support the intermediacy of 7
dehydrocholesterol 5alpha,6alpha-epoxide. Moreover, 7-dehydrocholesterol, 3beta
hydroxy-5beta-cholest-7-en-6-one (5beta-ketol), and 3beta,14alpha-dihydroxy-5beta
cholest-7-en-6-one (5beta-ketodiol) were converted into 20-hydroxyecdysone. Thus,
the pathway cholesterol-->7-dehydrocholesterol-->7-dehydrocholesterol
5alpha,6alpha-epoxide-->5beta-ketol-->5beta-k etodiol is proposed for the early
stages of 20-hydroxyecdysone biosynthesis. 3beta-Hydroxy-5beta-cholestan-6-one
was also incorporated into 20-hydroxyecdysone, suggesting that the introduction
of a 7-ene function is not necessarily next to cholesterol. C-25 Hydroxylation
during 20-hydroxyecdysone biosynthesis was found to proceed with ca. 70%
retention and 30% inversion. Finally, clerosterol was shown to be a precursor of
cyasterone and isocyasterone.
PMID- 10783006
TI - Cholesterol synthesis in the vertebrate retina: effects of U18666A on rat retinal
structure, photoreceptor membrane assembly, and sterol metabolism and
composition.
AB - Treatment of neonatal rats with U18666A, an inhibitor of desmosterol delta24
reductase, results in accumulation of desmosterol (delta5,24) and depletion of
cholesterol (delta5) in various bodily tissues and also causes cataracts. We
evaluated the effects of U18666A on the sterol composition, de novo sterol
synthesis, and histological structure of the retina. Neonatal Sprague-Dawley rats
were injected subcutaneously with U18666A (15 mg/kg, in olive oil ) every other
day from birth through 3 wk of age; in parallel, control rats received olive oil
alone. At 21 d, treated and control groups each were subdivided into two groups:
one group of each was injected intravitreally with [3H]acetate; retinas were
removed 20 h later and nonsaponifiable lipids (NSL) were analyzed by radio-high
performance liquid chromatography. The other group was injected intravitreally
with [3H]leucine; 4 d later, one eye of each animal was evaluated by light and
electron microscopy and light microscopic autoradiography, while contralateral
retinas and rod outer segment (ROS) membranes prepared therefrom were analyzed by
sodium dodecyl sulfate-polyacrylamide gel electrophoresis/fluorography. In the
treated group, the delta5/delta5,24 mole ratio of retinas was ca. 1.0, and >88%
of the NSL radioactivity was in delta5,24; in contrast, control retinas had
delta5/delta5,24 >170, with >80% of the NSL radioactivity in delta5. Retinal
histology, ultrastructure, ROS renewal rates, and rhodopsin synthesis and
intracellular trafficking were comparable in both treated and control animals.
These results suggest that desmosterol can either substitute functionally for
cholesterol in the retina or it can complement subthreshold levels of cholesterol
by sterol synergism.
PMID- 10783007
TI - Rationally designed inhibitors as tools for comparing the mechanism of squalene
hopene cyclase with oxidosqualene cyclase.
AB - The inhibition of squalene-hopene cyclase (SHC) (E.C. 5.4.99.-), an enzyme of
bacterial membranes catalyzing the formation of pentacyclic sterol-like
triterpenes, was studied by using different classes of compounds originally
developed as inhibitors of oxidosqualene cyclase (OSC) (E.C. 5.4.99.7), the
enzyme of eukaryotes responsible for the formation of tetracyclic precursors of
sterols. The mechanism of cyclization of squalene by SHC, beginning with a
protonation of the 2,3 double bond by an acidic residue of the enzyme, followed
by a series of electrophilic additions of the carbocationic intermediates to the
double bonds, is similar to the mechanism of cyclization of 2,3-oxidosqualene by
OSC. The inhibitors studied included: (i) analogs of the carbocationic
intermediates formed during cyclization, such as aza-analogs of squalene and 2,3
oxidosqualene; (ii) affinity-labeling inhibitors bearing a methylidene reactive
group; and (iii) vinyldioxidosqualenes and vinylsulfide derivatives of the
substrates. Comparison of the results obtained with the two enzymes, SHC and OSC,
showed that many of the most effective inhibitors of OSC were also able to
inhibit SHC, while some derivatives acted as specific inhibitors. Differences
could be easily explained on the basis of the different substrate specificity of
the two enzymes.
PMID- 10783008
TI - Structure-apoptotic potency evaluations of novel sterols using human leukemic
cells.
AB - Three oxidized analogs of cholesterol have been characterized for their ability
to cause apoptotic cell death in CEM-C7-14 human leukemic cells. In addition to
testing 15-ketocholestenol (K15), 15-ketocholestenol hydroxyethyl ether (CK15),
and 7-ketocholesterol hydroxyethyl ether (CK7), an oxysterol of known apoptotic
response, 25-hydroxycholesterol (25OHC), served as a standard for comparison.
Growth studies based on dye exclusion by viable cells while using a sublethal
concentration of oxysterols ranked their potency for cell kill as 25OHC > K15 >
CK15 > CK7. Both the TUNEL assay (terminal deoxynucleotidyl transferase-mediated
dUTP-X nick end labeling), which quantifies the amount of DNA nicks caused by a
toxic agent, and the MTT assay, which measures cell metabolism and thus reflects
cell viability, substantiated the same rank order. An ELISA assay for evaluating
release of DNA fragments into the cytosol after treatment gave a similar potency
order. The oncogene c-myc mRNA was suppressed by all three oxysterols, with 25OHC
and K15 being the most potent suppressors. Hoechst and Annexin V staining
documented that these oxysterols kill cells by an apoptotic pathway as evidenced
by condensation of nuclear chromatin and plasma membrane inversion, respectively.
From these in vitro studies, we believe that 25OHC, K15, and possibly CK15 have
the potential to be chemotherapeutic agents.
PMID- 10783009
TI - C27 to C32 sterols found in Pneumocystis, an opportunistic pathogen of
immunocompromised mammals.
AB - Pneumocystis carinii is the paradigm of opportunistic infections in
immunocompromised mammals. Prior to the acquired immunodeficiency syndrome (AIDS)
pandemic and the use of immunosuppressive therapy in organ transplant and cancer
patients, P. carinii was regarded as a curiosity, rarely observed clinically.
Interest in this organism exploded when it was identified as the agent of P.
carinii pneumonia (PcP), the direct cause of death among many AIDS patients.
Aggressive prophylaxis has decreased the number of acute PcP cases, but it
remains among the most prevalent opportunistic infections found within this
patient population. The taxonomic assignment of P. carinii has long been argued;
molecular genetics data now demonstrate that it is a fungus. Several antimycotic
drugs are targeted against ergosterol or its biosynthesis, but these are not as
effective against PcP as they are against other fungal infections. This can now
be explained in part by the identification of the sterols of P. carinii. The
organism lacks ergosterol but contains distinct C28 and C29 delta7 24
alkylsterols. Also, 24-methylenelanost-8-en-3beta-ol (C31) and pneumocysterol,
(24Z)-ethylidenelanost-8-en-3beta-ol (C32) were recently identified in organisms
infecting humans. Together, the delta7 24-alkylsterols and pneumocysterol are
regarded as signature lipids of the pathogen that can be useful for the diagnosis
of PcP, since no other lung pathogen is known to contain them. Cholesterol (C27),
the dominant sterol component in P. carinii, is probably totally scavenged from
the host. De novo synthesis of sterols has been demonstrated by the presence of
lovastatin-sensitive 3-hydroxy-3-methylglutaryl-CoA reductase activity, the
incorporation of radiolabeled mevalonate and squalene into P. carinii sterols,
and the reduction in cellular ATP in cells treated with inhibitors of enzymes in
sterol biosynthesis.
PMID- 10783010
TI - The effects of dehydroepiandrosterone on carcinogenesis, obesity, the immune
system, and aging.
AB - With the passage of the U.S. Dietary Supplement Health and Education Act of 1994,
dehydroepiandrosterone (DHEA, 5-androsten-3beta-ol-17-one) has become widely
available, and a large and growing market has developed for this "fountain of
youth." DHEA has been shown to have significant beneficial effects in animals,
which may lead to clinical uses in man. Historically, the U.S. Food and Drug
Administration removed DHEA from the over-the-counter market in 1985 because
there was no support for the health claims that were made for this product.
Almost all of the biological data was on animals and there was a lack of
demonstrated efficacy in humans. Recently there have been a number of small
clinical trials in humans but the results have not been as positive as in the
animal tests. This review will be restricted to the effects of DHEA on
carcinogenesis, obesity, the immune system, and aging. Four hypotheses have been
proposed to explain the underlying biochemical mechanism(s) by which DHEA exerts
its beneficial properties. The first is based on the inhibitory effect of DHEA on
mammalian glucose-6-phosphate dehydrogenase. This mechanism can explain the
antiinitiation and antipromotion steps in some cases of carcinogenesis. The
second biochemical mechanism involves the induction of peroxisomes and peroxisome
associated enzymes. The third explanation is that DHEA works in a similar fashion
to the known anticarcinogenic action of food restriction. An antiglucocorticoid
mechanism has also been suggested. A hypothesis for the increase followed by the
decrease in the levels of DHEA with age is proposed. A number of new synthetic
DHEA analogs have been synthesized and tested. They offer the best hope for the
development of a clinically useful drug based on the properties of DHEA.
PMID- 10783011
TI - Plasma oxysterols and tocopherol in patients with diabetes mellitus and
hyperlipidemia.
AB - The plasma levels of free oxysterols (7-ketocholesterol; 7alpha-hydroxy-, 7beta
hydroxy-, 25-hydroxy-, and 27-hydroxycholesterol; and 5alpha,6alpha
epoxycholestanol) in patients with diabetes mellitus and hypercholesterolemia
were determined using gas chromatography-mass spectrometry with selective ion
monitoring. We studied 39 patients with diabetes mellitus, 20 nondiabetic
patients with hypercholesterolemia, and 37 normal controls. Plasma cholesterol
levels in diabetic and hypercholesterolemic patients showed no statistical
difference. Plasma 7-ketocholesterol was significantly higher in patients with
diabetes (31.6+/-2.8 ng/mL) or hypercholesterolemia (52.3+/-5.9) than in the
control group (22.4+/-1.2). The increased plasma cholesterol can be regarded as
an oxidation substrate for the oxidant stress and the higher absolute levels of
oxysterols in hypercholesterolemic plasma compared with the control plasma. This
difference disappeared when 7-ketocholesterol was expressed in proportion to
total cholesterol. The oxidizability of plasma cholesterol was evaluated by
comparing the increased ratio of 7-ketocholesterol after CuSO4 oxidation to the
ratio before. We demonstrated that the patients with diabetes showed increased
oxidizability (77.5%) compared with the control (36.6%) or hyperlipemic group
(45.3%), which is likely due to the lower amounts of alpha-tocopherol in the
diabetics. Measurement of oxysterols may serve as a marker for in vivo oxidized
lipoproteins in diabetes and hyperlipemia.
PMID- 10783013
TI - Challenges of evaluating homeopathic treatment of acute otitis media.
PMID- 10783012
TI - Use of a 13C tracer to quantify the plasma appearance of a physiological dose of
lutein in humans.
AB - Increased intake of lutein from vegetables promotes increased density of the
macular pigment and therefore may protect against age-related macular
degeneration. Our objective was to use a 13C tracer and high-precision gas
chromatography-combustion interfaced-isotope ratio mass spectrometry (GC-C-IRMS)
to investigate metabolism of a lutein dose equivalent to that absorbed from
vegetables. Biosynthetic per-labeled (>99% 13C) lutein was purified from a
commercially available extract of algal biomass. Subjects (n = 4) ingested 3 mg
of [13C]lutein with a standardized low-carotenoid breakfast. Blood samples were
collected at baseline and then hourly for 12 h; additional blood samples were
drawn at 16, 24, 48, 72, 96, 192, 360, and 528 h. To produce perhydro-beta
carotene suitable for analysis by GC-C-IRMS, the plasma lutein fraction was
hydrogenated on palladium-on-carbon catalyst with acid-catalyzed hydrogenolysis.
The stable carbon isotope (13C/12C) ratio measured by GC-C-IRMS was used to
calculate the plasma concentration of [13C]lutein. There was a rapid increase in
[13C]lutein in plasma until peak enrichment at 16 h followed by a decline to the
next measurement at 24 h. At 528 h, small changes in 13C enrichment from baseline
could still be measured in plasma lutein. High-precision GC-C-IRMS enables
complete definition of the appearance and disappearance of [13C]lutein in plasma
after ingestion of a dose similar to that absorbed from foods.
PMID- 10783014
TI - Adult formulation of a five component acellular pertussis vaccine combined with
diphtheria and tetanus toxoids and inactivated poliovirus vaccine is safe and
immunogenic in adolescents and adults.
AB - BACKGROUND: Pertussis is increasingly recognized as an important cause of cough
illness in adolescents and adults. PURPOSE: To evaluate the safety and antibody
response to a single dose of an adult formulation of a five component (pertussis
toxoid, filamentous hemagglutinin, pertactin, fimbriae 2 and 3) acellular
pertussis vaccine (aP) combined with diphtheria and tetanus toxoids (TdaP) and
inactivated poliovirus vaccine (TdaP-IPV) in adolescents and adults and to assess
the response to a second dose of the acellular pertussis vaccine in a subset of
the adults. POPULATION AND SETTING: The study addressed 1207 healthy participants
(736 adults and 466 adolescents) recruited in five Canadian communities. STUDY
DESIGN: In a randomized, observer-blind, controlled clinical trial, adult
participants received Td followed at a separate visit by aP, TdaP followed by IPV
or TdaP-IPV; adolescents received Td-IPV followed at a separate visit by aP or
TdaP-IPV. A subgroup of adults was given a booster of aP 1 month after TdaP.
OUTCOME MEASURES: Antibody titers measured before and 1 month after each
immunization; adverse events enumerated at 24 h, 72 h and 8 to 10 days. RESULTS:
The aP vaccine given by itself was associated with adverse events less frequently
than were Td, Td-IPV, TdaP or TdaP-IPV vaccines, but reaction rates did not
differ significantly among the latter products. The antibody response against
Bordetella pertussis antigens was vigorous in all groups, although adults given
the TdaP-IPV vaccine had lower antibody titers against filamentous hemagglutinin,
pertactin, diphtheria and tetanus antibodies than those given TdaP vaccine.
Similarly adolescents given TdaP-IPV had lower antibody titers against pertussis
toxin, filamentous hemagglutinin, fimbriae and agglutinins than those given Td
IPV and aP alone. A second dose of acellular pertussis vaccine was not associated
with increased adverse events in adults but elicited increased antibody titers
over that achieved by a single dose only against pertussis toxin. CONCLUSIONS:
This adult formulation five component aP vaccine given as TdaP-IPV is safe and
immunogenic in adolescents and adults and is a candidate vaccine for adolescent
and adult immunization programs.
PMID- 10783015
TI - Vitamin A supplementation of South African children with severe diarrhea: optimum
timing for improving biochemical and clinical recovery and subsequent vitamin A
status.
AB - BACKGROUND: Vitamin A has well-recognized benefits for prevention of diarrhea,
but the impact of therapeutic doses given during diarrhea on biochemical and
clinical outcomes is less clear. We investigated these potential therapeutic
benefits within a study of the optimum time for vitamin A supplementation to
promote vitamin A status. METHODS: Young children with severe diarrhea were
randomized to receive 60 mg of retinol as retinyl palmitate during acute diarrhea
or once symptoms had resolved, usually after 5 to 8 days. Either during acute
diarrhea or after its resolution, children not receiving vitamin A were given
identical placebo. On Days 0 and 3 we measured urinary neopterin, plasma retinol
and acute phase proteins and intestinal permeability by the lactulose/mannitol
test. Eight weeks after discharge children returned to hospital for a modified
dose response test of vitamin A stores. RESULTS: Most children presented with
watery diarrhea and grossly abnormal intestinal permeability and immune
activation markers. At 8 weeks plasma retinol concentrations of children
receiving vitamin A during acute diarrhea, compared with those receiving it in
early convalescence [0.67 (95% confidence interval, 0.58 to 0.76) micromol/l vs.
0.68 (95% confidence interval, 0.59 to 0.79) micromol/l], and the proportion of
children with deficient vitamin A stores (7 of 34 vs. 8 of 34) did not differ.
Clinical features, lactulose/mannitol tests and urinary neopterin concentrations
on Day 3 also did not differ significantly when vitamin A was given early or
late. CONCLUSIONS: Even when it was given during severe diarrhea, a large dose of
vitamin A improved vitamin A stores in a population in whom vitamin A deficiency
is a public health problem. Vitamin A did not significantly improve early
clinical or biochemical recovery from severe diarrhea.
PMID- 10783016
TI - More laboratory testing: greater cost but not necessarily better.
AB - BACKGROUND: The bacterial latex agglutination assay is ordered predominantly on
the pediatric population, for rapid screening for bacterial surface antigens in
cerebrospinal fluid (CSF) or urine specimens. The high cost of this assay and
questions raised in the literature regarding its accuracy led to a retrospective
review of the use of this assay at a medium-sized midwest teaching hospital. The
results of 6,370 bacterial latex agglutination tests performed between May, 1995,
and November, 1996, and charts of patients being tested were reviewed. RESULTS:
This study demonstrated a sensitivity and specificity of 28.6% and 86.7% for
urine specimens and 70.0% and 99.4% for CSF specimens. A total of 11 pathogens
were accurately detected (7 CSF and 4 urine). There were 13 false negatives and
59 false positives. None of the true positives had a discernible effect on either
treatment or hospital course; however, several of the erroneous tests resulted in
delayed or unnecessary treatment and workup of the involved patients. The annual
billed cost of this test at this institution (fiscal years 1995 to 1997) averaged
$167,000 per annum. This does not include indirect costs associated with
increased length of hospital stay, overutilization of antibiotics and excess
laboratory tests ordered as a result of false positives. CONCLUSIONS: Bacterial
antigen latex agglutination testing is neither sufficiently sensitive nor
specific to be used as a screening test. Accurate results have no demonstrable
clinical impact, whereas numerous inaccurate results are often generated at great
cost. The continued use of the latex agglutination assay should be seriously
questioned in an era when cost containment and clinical efficiency are becoming
increasingly important.
PMID- 10783017
TI - Etiology of community-acquired pneumonia in 254 hospitalized children.
AB - BACKGROUND: Childhood community-acquired pneumonia is a common illness, but there
have been relatively few comprehensive studies of the viral and bacterial
etiology in developed countries. The aim of the present investigation was to
determine the etiology of community-acquired pneumonia in hospitalized children
by several laboratory methods. METHODS: In a 3-year prospective study a
nasopharyngeal aspirate for viral studies and acute and convalescent serum
samples for viral and bacterial serology were taken from 254 children with
symptoms of acute infection and infiltrates compatible with pneumonia in the
chest radiograph. The role of 17 microbes was investigated. RESULTS: A potential
causative agent was detected in 215 (85%) of the 254 patients. Sixty-two percent
of the patients had viral infection, 53% had bacterial infection and 30% had
evidence of concomitant viral-bacterial infection. Streptococcus pneumoniae
(37%), respiratory syncytial virus (29%) and rhinovirus (24%) were the most
common agents associated with community-acquired pneumonia. Only one patient had
a positive blood culture (S. pneumoniae) of 125 cultured. A dual viral infection
was detected in 35 patients, and a dual bacterial infection was detected in 19
patients. CONCLUSIONS: The possible causative agent of childhood community
acquired pneumonia can be detected in most cases. Further studies are warranted
to determine what etiologic investigations would aid in the management of
pneumonia. With effective immunization for S. pneumoniae and respiratory
syncytial virus infections, more than one-half of the pneumonia cases in this
study could have been prevented.
PMID- 10783018
TI - Predictive value of pneumococcal nasopharyngeal cultures for the assessment of
nonresponsive acute otitis media in children.
AB - BACKGROUND: Nonresponsive acute otitis media (NR-AOM) is reported in > 10% of
children with AOM treated with antibiotics. Drug-resistant Streptococcus
pneumoniae is currently considered the leading cause of antibiotic failures in
AOM. Nasopharyngeal colonization with S. pneumoniae was found to increase
significantly during episodes of AOM. OBJECTIVES: To investigate the
nasopharyngeal colonization with S. pneumoniae during NR-AOM and compare it with
that found in AOM not recently treated with antibiotics (NT-AOM); to assess the
predictive value of nasopharyngeal pneumococcal cultures results for the
bacteriologic assessment of NR-AOM. MATERIALS AND METHODS: Patients age 3 to 48
months with NT-AOM and NR-AOM were prospectively studied. Simultaneous
nasopharyngeal cultures for S. pneumoniae and middle ear fluid cultures were
obtained at enrollment. Antibiotic susceptibility testing was performed in all S.
pneumoniae isolates. Penicillin and ceftriaxone MICs for S. pneumoniae were
determined by E-test. The sensitivity, specificity and positive and negative
predictive values of positive or negative nasopharyngeal cultures for the
presence of S. pneumoniae in middle ear fluid were calculated. RESULTS: We
studied 362 and 217 children with NT-AOM and NR-AOM, respectively. Of the
children with NT-AOM and NR-AOM, 95 and 97%, respectively, were younger than 2
years of age. S. pneumoniae was isolated in the nasopharynx of 66 and 58% of
children with NT-AOM and NR-AOM, respectively. Penicillin-nonsusceptible S.
pneumoniae was isolated more frequently from the nasopharynx of patients with NR
AOM than from those with NT-AOM (84% vs. 47%; P < 0.01). Antibiotic
susceptibility patterns were similar for S. pneumoniae isolates recovered from
the nasopharynx and those from the middle ear fluid in both NT-AOM and NR-AOM. A
positive nasopharyngeal culture had only little predictive value for the presence
of S. pneumoniae in middle ear fluid (41 and 51% for NT-AOM and NR-AOM,
respectively). However, the negative predictive value of nasopharyngeal cultures
for recovery of S. pneumoniae in NR-AOM was high and significantly higher in NR
AOM than in NT-AOM (91% vs. 78%, respectively; P = 0.009). The negative
predictive value of nasopharyngeal cultures for recovery of antibiotic-resistant
S. pneumoniae was 95 and 93% in NT-AOM and NR-AOM, respectively. Conclusions. A
significantly higher nasopharyngeal colonization rate with antibiotic-resistant
S. pneumoniae was found in patients with NR-AOM than in those with NT-AOM.
Negative nasopharyngeal culture for antibiotic-resistant S. pneumoniae
practically rules out its presence in middle ear fluid.
PMID- 10783019
TI - Effect of rapid diagnosis on management of influenza A infections.
AB - BACKGROUND: Few studies have examined the impact of rapid viral diagnostic tests
on patient management. OBJECTIVE: To assess the effect of rapid diagnosis of
influenza A infections on patient management. METHODS: The medical records of
children with respiratory infections who were evaluated at a children's hospital
between July 1, 1995, and June 30, 1997, were reviewed. Children (n = 56)
evaluated in the Emergency Department (ED) who had a positive influenza A enzyme
immunoassay (EIA) were compared with two control groups for the likelihood of
admission, antibiotic use and duration of hospitalization and antibiotic
administration. RESULTS: Patients discharged from the ED with a positive EIA test
were less likely to receive antibiotics than those with a negative EIA test (20%
vs. 53%; P = 0.04). Patients admitted to the hospital with a positive EIA test
were as likely to receive antibiotics as those without a rapid diagnosis, but the
duration of antibiotic administration was significantly shorter in the group with
a positive EIA test (3.5 vs. 5.4 days; P = 0.03). Patients with a positive EIA
test also were more likely to receive antiviral therapy than either control group
(25% vs. 0 and 1.8%; P < 0.001). CONCLUSIONS: The detection of influenza A by EIA
has a positive impact on medical management by decreasing antibiotic use in
pediatric patients evaluated in an ED, by decreasing the duration of antibiotic
use in hospitalized patients and by encouraging antiviral therapy.
PMID- 10783020
TI - Viral infections in children undergoing hematopoietic stem cell transplant.
AB - BACKGROUND: Although viral infection is a major clinical problem for
hematopoietic stem cell transplant recipients, there are few large series
reporting on these infections in the pediatric population. We performed a
retrospective analysis of the impact of viral infections in this patient
population in our center, managed by a uniform antiviral prophylaxis protocol.
METHOD: We reviewed the medical records of consecutive children and adolescents
who received hematopoietic stem cell transplantation at the Division of
Pediatrics, The University of Texas M. D. Anderson Cancer Center in Houston, TX,
from July, 1992 to August, 1996. RESULTS: During the study period there were 70
episodes of viral infections in 96 transplants. The viruses most commonly
encountered were cytomegalovirus (24), varicella-zoster (21) and herpes simplex
(10). Fifty of these episodes resulted in clinically apparent diseases, affecting
39 patients. The Kaplan-Meier estimated probability for the development of viral
diseases was 62%. Ten percent of these patients died as a direct result of the
infectious process, all within 4 months of transplant. Significant factors for
development of viral disease were the development of acute graft-vs.-host disease
and the duration of preengraftment neutropenia. CONCLUSIONS: Viruses are common
pathogens after hematopoietic stem cell transplantation in the pediatric
population. Despite routine antiviral prophylaxis the morbidity and mortality of
viral infections remain high. Enhancement of immune recovery after hematopoietic
stem cell transplantation together with the development of new classes of
antiviral agents may impact the incidence and prognosis of viral infections in
this setting.
PMID- 10783021
TI - Bacteremia in febrile Malawian children: clinical and microbiologic features.
AB - BACKGROUND: There are no published data for the incidence or etiology of
childhood bacteremia in Malawi. We describe the clinical and microbiologic
features of children admitted to hospital from whom blood cultures yielded
bacterial pathogens. METHODS: Any neonate or child admitted to the pediatric
wards of the Queen Elizabeth Central Hospital had a blood culture taken in the
event of fever without obvious clinical explanation. Clinical and microbiologic
data were prospectively collected for children with a significant positive
culture. RESULTS: Between September, 1996, and August, 1997, we processed 2,123
cultures. Of these, 365 (17.2%) grew a pathogen. Non-typhi salmonellae (NTS) and
enteric Gram-negative bacilli constituted 67.4% of isolates, and Streptococcus
pneumoniae constituted 16.4%. More than two-thirds of NTS episodes coincided with
the peak malaria transmission season (January to June); 67% of bacteremic
children were malnourished, 28% severely so. Patients with NTS bacteremia were
significantly more likely to have coincident malaria and to have splenomegaly and
anemia than children with other infecting organisms. The overall mortality was
38% but varied considerably according to age and nutritional status. Prior
antibiotic use, coincident malaria or meningitis did not adversely affect
outcome. In vitro resistance to the commonly available antibiotics ampicillin and
trimethoprim-sulfamethoxazole was found in 76 and 71% of NTS isolates. Screening
tests for penicillin resistance suggested a rate of 21% among pneumococci.
CONCLUSIONS: Bacteremia is common in hospitalized Malawian children and has a
high mortality. There are high rates of resistance to some of the commonly used
antibacterial agents.
PMID- 10783022
TI - Risk factors for candidemia in Neonatal Intensive Care Unit patients. The
National Epidemiology of Mycosis Survey study group.
AB - BACKGROUND: Candida species are important nosocomial pathogens in neonatal
intensive care unit (NICU) patients. METHODS: A prospective cohort study was
performed in six geographically diverse NICUs from 1993 to 1995 to determine the
incidence of and risk factors for candidemia, including the role of
gastrointestinal (GI) tract colonization. Study procedures included rectal swabs
to detect fungal colonization and active surveillance to identify risk factors
for candidemia. Candida strains obtained from the GI tract and blood were
analyzed by pulsed field gel electrophoresis to determine whether colonizing
strains caused candidemia. RESULTS: In all, 2,847 infants were enrolled and 35
(1.2%) developed candidemia (12.3 cases per 1,000 patient discharges or 0.63 case
per 1,000 catheter days) including 23 of 421 (5.5%) babies < or =1,000 g. After
adjusting for birth weight and abdominal surgery, forward multivariate logistic
regression analysis demonstrated significant risk factors, including gestational
age <32 weeks, 5-min Apgar <5; shock, disseminated intravascular coagulopathy,
prior use of intralipid, parenteral nutrition, central venous catheters, H2
blockers, intubation or length of stay > 7 days before candidemia (P < 0.05).
Catheters, steroids and GI tract colonization were not independent risk factors,
but GI tract colonization preceded candidemia in 15 of 35 (43%) case patients.
CONCLUSIONS: Candida spp. are an important cause of late onset sepsis in NICU
patients. The incidence of candidemia might be decreased by the judicious use of
treatments identified as risk factors and avoiding H2 blockers.
PMID- 10783023
TI - Meningococcal disease in Dallas County, Texas: results of a six-year population
based study.
AB - OBJECTIVE: Neisseria meningitidis is an important cause of serious bacterial
infection in children and adults in the US. From 1992 to 1997 invasive disease
caused by N. meningitidis was studied among 1.9 million residents of Dallas
County, TX METHODS: The demographic characteristics and diagnoses of 151 patients
were identified through active, population-based surveillance and review of
medical records. Serogroups were determined for strains infecting 129 (85%)
patients. RESULTS: The average annualized incidence rate was 1.3 cases per
100,000 person years and was highest for children <1 year (13 cases/100,000
person years). Older patients (50+ years old) were more likely to present with
pneumonia and less likely to present with meningitis than younger patients.
Neither the fatality rate nor the duration of hospitalization for surviving
patients was associated with age. Among patients with a known serogroup,
serogroup C disease was found in 35% of cases <1 year old, 64% of those 1 to 49
years old and 44% of those 50+ years old. Serogroup B strains were isolated from
26% of patients <1 year, 17% of patients 1 to 49 years old and none of the
patients 50+ years old. Serogroup Y disease increased from 22% to 35% of cases
between 1992 and 1997 (P = 0.03). This serogroup was identified in 26% of
patients <1 year old, 17% of patients 1 to 49 years old and in 50% of patients
50+ years old. Serogroup C and Y accounted for 61% of cases in children <1 year
old and for 79% of cases in all age groups. CONCLUSION: The results underscore
the importance of conjugate vaccines for serogroups C and Y.
PMID- 10783024
TI - Streptococcus pneumoniae antimicrobial susceptibility testing.
PMID- 10783025
TI - Pneumococcal conjugate vaccines.
PMID- 10783026
TI - Vaccines for prevention of meningococcal disease.
PMID- 10783027
TI - Neonatal gonococcal arthritis after negative prenatal screening and despite
conjunctival prophylaxis.
PMID- 10783028
TI - Kawasaki disease associated with measles virus infection in a monozygotic twin.
PMID- 10783029
TI - Costs of otitis media in a managed care population.
PMID- 10783030
TI - Genetic analysis of sin nombre hantavirus in Iowa.
PMID- 10783031
TI - Rash and petechiae as presenting signs of Q fever.
PMID- 10783032
TI - Early onset neonatal sepsis caused by serotype VIII group B streptococci.
PMID- 10783033
TI - Home monitoring of the middle ear system with spectral gradient acoustic
reflectometry: distinguishing acute otitis media from upper respiratory
infection.
PMID- 10783034
TI - Pseudomonas folliculitis in a young child.
PMID- 10783036
TI - Diagnosis of Helicobacter pylori infection with a novel stool antigen-based assay
in children.
PMID- 10783035
TI - Genotypic characterization of human immunodeficiency virus type 1 isolated from
vertically infected children with antiretroviral therapy experience.
PMID- 10783037
TI - Flurithromycin-induced acute interstitial nephritis.
PMID- 10783038
TI - Etiology and treatment of pneumonia.
AB - BACKGROUND: Lower respiratory tract infections are a common cause of morbidity
among children. Among these infections pneumonia is the most serious illness and
can be difficult to diagnose. The etiology of pneumonia is still partly unknown,
primarily because of difficulty in obtaining adequate samples and lack of
reliable diagnostic methods. ETIOLOGY OF PNEUMONIA: Streptococcus pneumoniae is
recognized as an important cause of pediatric pneumonia regardless of age in both
the inpatient and outpatient setting. In developed countries S. pneumoniae
probably accounts for 25 to 30% of cases of pediatric community-acquired
pneumonia. Viruses (mostly respiratory syncytial virus) are responsible for
approximately 20% of cases, and Chlamydia pneumoniae and Mycoplasma pneumoniae
occur commonly in older children. FUTURE CHALLENGES: Despite the effectiveness of
antimicrobial therapy, the emergence of resistant bacterial pathogens has
resulted in increased interest in developing more effective vaccines. If
conjugate pneumococcal vaccines prove effective at eradicating carriage of
pneumococci in the nasopharynx, immunization may be an important tool against the
spread of pneumococcal disease. Future challenges include implementation of
effective intervention strategies, production of simple diagnostic tools and
development of effective vaccines.
PMID- 10783039
TI - Clinical significance of resistant organisms in otitis media.
AB - BACKGROUND: Otitis media is an important health care problem of childhood. The
bacteriology of otitis media comprises three main pathogens: Streptococcus
pneumoniae, nontypable Haemophilus influenzae and Moraxella catarrhalis. Although
the prevalence of resistant strains varies geographically and temporally,
antimicrobial resistance is widespread and increasing. RESISTANCE TO ANTIBIOTIC
DRUGS: Among the risk factors for development of resistance in otitis media are
antimicrobial use, young age, day-care attendance and prior hospitalization. The
increasing rate of resistance to antibiotic drugs is associated with a decreased
rate of successful eradication of pathogens from middle ear fluid, which is
associated with clinical failure. A bacteriologic cure rate of 80 to 85% is
observed for S. pneumoniae and nontypable H. influenzae when serum concentrations
exceed the MIC for 40 to 50% of dosing interval. Comparative trials indicate that
some of the beta-lactams can achieve bacteriologic eradication in acute otitis
media, although major differences in outcome exist among agents based on
pathogen, beta-lactamase status and MIC values. ANTIBIOTIC CHOICE: Overall the
choice of antibiotics for treatment of otitis media should take into
consideration their in vitro activity against the locally prevalent organisms,
especially resistant organisms, and results obtained from studies in which
bacteriologic outcome was used as the endpoint.
PMID- 10783040
TI - Management of otitis media: 2000 and beyond.
AB - BACKGROUND: In the next few years what will alter our modes of diagnosis, choice
of therapies and strategies for prevention of acute otitis media (AOM)? These
issues, as well as whether antibiotic resistance will continue to threaten the
efficacy of currently available antimicrobial agents, whether industry and
academia will be able to respond to bacterial resistance with effective new
antimicrobial drugs and whether the pneumococcal conjugate vaccine will
substantially reduce the incidence of AOM provide a basis for discussing the
problems and possible solutions related to AOM. ANTIMICROBIAL DRUGS: Bacteria and
viruses will continue to find ways to survive the activity of currently available
antimicrobial drugs. Among the new antibacterial drugs under consideration are
ketolides, oxazolodinones and quinolones. Guidelines stress limiting usage of
antimicrobial agents to diseases that are likely caused by bacterial pathogens.
Antiviral drugs are now available against influenza virus and respiratory
syncytial virus infections. DIAGNOSIS: Tympanometry and/or acoustic reflectometry
are adjunctive techniques for assisting in the diagnosis of middle ear effusion
in children whose otoscopic examination is ambiguous. Laser myringotomy has been
used in several hundred children; however, there are no published studies of
randomized trials. NEW VACCINES: Investigators have evaluated the safety and
efficacy of a heptavalent pneumococcal polysaccharide vaccine conjugated with
CRM197 (a diphtheria toxin mutant). The results showed a reduction in the overall
burden of severe and recurrent AOM. Respiratory syncytial virus is the viral
pathogen most frequently associated with AOM. For this reason safe and effective
viral vaccines are needed to complement the efficacy of bacterial vaccines for
prevention of AOM. CONCLUSIONS: Parents influence decisions by pediatricians to
use antimicrobial agents and should be informed about the appropriate usage of
antibiotics. Educators and public health officials must find techniques to
distinguish WebSites that provide information of value from those that are not
credible. Of paramount importance is the development of techniques to increase
the accuracy of clinical and microbiologic diagnosis. Finally there is a need for
studies of appropriate scientific design that can assess the efficacy and safety
of alternative therapies.
PMID- 10783041
TI - Immunogenicity of pneumococcal conjugate vaccines.
AB - BACKGROUND: Prevention of pneumococcal infections is a public health priority
because of the high impact of the disease and because of the increasing problems
due to antimicrobial resistance. Traditional vaccines, consisting of purified
capsular polysaccharides (PSs) of Streptococcus pneumoniae, are not immunogenic
in young children. In addition they confer only limited protection in patients
with immunodeficiencies and hematologic malignancies. IMMUNOGENICITY OF
PNEUMOCOCCAL CONJUGATE VACCINES: Immunogenicity of the PS vaccine has been
enhanced by coupling pneumococcal PSs to proteins to produce a conjugate vaccine.
Conjugate molecules are designed to possess T cell dependent properties, such as
immunogenicity in early infancy, stimulation of high levels of IgG isotype
antibodies and enhanced immunologic memory responses. In the clinical studies
multivalent pneumococcal conjugate vaccines have been shown to induce an IgG
dominating serum antibody response against common pneumococcal serotypes causing
infections in children. A booster dose later in life creates a robust and rapid
antibody response, indicating the existence of immunologic memory in primed
children. Antibodies induced by conjugate vaccines are functionally active, as
demonstrated by their high avidity and opsonophagocytic activity.
PMID- 10783042
TI - Efficacy of pneumococcal conjugate vaccines in large scale field trials.
AB - BACKGROUND: Each year Streptococcus pneumoniae causes approximately 1.2 million
deaths worldwide from pneumonia. In the United States S. pneumoniae is estimated
to cause 500,000 cases of pneumonia and 7 million episodes of acute otitis media
annually. CONJUGATE VACCINES: The current pneumococcal polysaccharide vaccine is
ineffective in children <2 years old and may not produce an adequate antibody
response until children reach the age of 5 years. Pneumococcal conjugate vaccines
are immunogenic after primary and booster vaccination in young children and in
children and adults with immunodeficiencies. Immunization with conjugate vaccines
also induces a strong and rapid anamnestic response and enhanced functional
activity of antibodies. Two large scale field trials of pneumococcal conjugate
vaccines were initiated in 1995, 1 in California and 1 in Finland. The California
trial, involving 37,868 children, evaluated the efficacy of a 7-valent conjugate
for the prevention of invasive pneumococcal disease and secondarily evaluated its
efficacy for acute otitis media and pneumonia. RESULTS: Preliminary results
indicate 94% efficacy against invasive pneumococcal disease caused by serotypes
included in the vaccine in fully or partially vaccinated children. Preliminary
evidence from large scale field trials indicates that pneumococcal conjugate
vaccines are effective in reducing invasive pneumococcal disease as well as acute
otitis media and pneumonia in children and represents a significant advance in
the prevention of childhood infectious diseases.
PMID- 10783043
TI - Prevalence of migraine and Raynaud's phenomenon in Japanese patients with
vasospastic angina.
AB - The prevalence of migraine and Raynaud's phenomenon in Japanese patients with
vasospastic angina (group I) were compared with those in 2 control groups: one
with effort angina (group II) and the other group without known ischemic heart
disease (group III). There were no significant differences among the 3 groups
with respect to age and sex. The prevalence of migraine in group I was 23 of 100,
as compared with 4 of 100 in group II (p<0.01) and 11 of 100 in group III
(p<0.05). The prevalence of Raynaud's phenomenon in group I was 9 of 100, as
compared with 3 of 100 in group II and 4 of 100 in group III. Thus, in Japan, the
prevalence of migraine in patients with vasospastic angina was higher than those
in the 2 control groups, whereas the prevalence of Raynaud's phenomenon did not
differ significantly among the 3 groups. The prevalence of Raynaud's phenomenon
in Japanese patients with vasospastic angina was different from that reported
from North America, although the prevalence of migraine was the same. This may be
partially explained by racial differences.
PMID- 10783044
TI - Ultrasonographic study of carotid artery structural changes with natural
longevity.
AB - The changes in carotid artery structure during the natural longevity of the
Uighurs people were compared with other ethnic groups. The 419 subjects were
divided into (1) longevity and (2) older groups as follows: Uighurs longevity
group in Hotan (ULH); and Uighurs, Hans and Kazaks older groups in Hotan or
Balikun (UOH, HOH, HOB and KOB). The wall thickness of the common carotid artery
(CCA) was measured by ultrasonography. Risk factors were evaluated by measuring
total cholesterol (T-C), high-density lipoprotein cholesterol (HDL-C), low
density lipoprotein cholesterol (LDL-C), triglyceride (TG) and fasting glucose,
and by 24-h ambulatory blood pressure monitoring. Wall thickness and blood
pressure were greater in the Balikun groups than in the Hotan groups. The CCA
wall was thicker in Uighurs and Kazaks than in Hans, in the ULH than in the UOH.
There was no significant difference in blood pressure among the Hotan groups. LDL
C and glucose were higher and HDL-C was lower in the Hotan groups than in the
Balikun groups. T-C, LDL-C, TG and glucose were higher in the HOH than in the ULH
and UOH. Systolic blood pressure and LDL-C were higher and TG was lower in the
KOB than in the HOB. These results suggest that an increased CCA wall thickness
can be attributed to age in Hotan, and to a higher blood pressure level in
Balikun, and that the higher blood pressure affected the Balikun groups more than
the Hotan groups.
PMID- 10783045
TI - Hemodynamic effects of phosphodiesterase III inhibitor in patients with a large
ventricular left-to-right shunt.
AB - The hemodynamic effects of olprinone, a newly synthesized phosphodiesterase (PDE)
III inhibitor, were assessed in patients with a large cardiac left-to-right
shunt. Ten patients with a large ventricular septal defect (VSD) were evaluated
during cardiac catheterization. Olprinone was administered as a bolus, 20
microg/kg body weight, and hemodynamic data were obtained before and after the
administration. Heart rate and systemic flow increased significantly after
administration. On the other hand, olprinone significantly reduced left and right
atrial pressure, the systolic pulmonary/arterial pressure ratio, and systemic
vascular resistance. However, pulmonary flow and pulmonary vascular resistance
were not changed. These results suggested that olprinone had a positive inotropic
effect and selective vasodilator effect on patients with a large ventricular left
to-right shunt. Thus, PDE inhibitors may be beneficial for the treatment of
patients with a large VSD.
PMID- 10783046
TI - Clinical characteristics of patients with fresh left ventricular thrombus.
AB - The present study analyzed the clinical backgrounds of 9 patients with fresh left
ventricular thrombus (LVT) detected by two-dimensional echocardiography during
the past 5 years. Patients with acute myocardial infarction were excluded. Left
ventricular systolic function was disturbed either diffusely or segmentally in
all patients with a mean ejection fraction of 33%. In 7 patients,
echocardiography was performed shortly after furosemide therapy for New York
Heart Association class IV congestive heart failure; echocardiography was also
performed just before treatment in 4 of the 7 patients and LVT was not detected
in any of them. Two patients died of underlying disorders within 2 months of
detection of the thrombus. However, the LVT disappeared in the other 7 patients
without any thromboembolic episodes during the 6 months after starting
anticoagulant therapy. As fresh LVT developed shortly after diuretic therapy in
patients with severe congestive heart failure associated with left ventricular
systolic dysfunction, concomitant anticoagulant therapy is recommended.
PMID- 10783047
TI - A low amplitude His-bundle potential predicts failure of the right-sided approach
for atrioventricular junction ablation.
AB - In 30 patients with drug refractory atrial fibrillation-flutter who underwent
radiofrequency (RF) ablation of the atrioventricular (AV) junction, 23 were
successfully ablated using the conventional right-sided approach (group A). Seven
patients required a left-sided approach (group B) after multiple applications
from the conventional right-sided approach failed to produce complete AV block.
The amplitude of the His-bundle potential recorded at the ablation site differed
significantly between the 2 groups (0.23+/-0.11 mV in group A vs 0.12+/-0.04 mV
in group B; p<0.005). Also, the amplitude of the His-bundle potential recorded in
the standard position across the tricuspid annulus differed significantly between
the 2 groups (0.27+/-0.35 mV in group A vs 0.11+/-0.44 mV in group B; p<0.007).
There was no significant difference in the amplitude of the ventricular potential
between the 2 groups. The probability of successful ablation of the AV junction
with a conventional right-sided approach was 6 out of 12 patients (50%) if the
His amplitude was <0.12mV, and 17 out of 18 patients (94%) if the His amplitude
was >0.12mV (p<0.005). Patients in group B had a mean of 20.5+/-13.0 failed right
sided RF applications (5-33 applications), but required a mean of only 2
subsequent RF applications for success on the left side (1-6 applications). The
His-amplitude recorded from the left side using the same catheter was
significantly greater than that on the corresponding right-side (0.22+/-0.09 mV
on the left side vs 0.12+/-0.04 mV on the right side: p<0.05). Total mean
fluoroscopic time was 62+/-12min for group B and 20+/-13min for group A patients.
In patients that underwent RF ablation of the AV junction, a maximum His
amplitude <0.12 mV predicted a success rate of approximately 50% in the present
study. An early switch to a left-sided approach may avoid multiple RF
applications and prolonged fluoroscopic time in patients with a low amplitude His
bundle potential.
PMID- 10783048
TI - Endothelialization of the coils used to occlude a persistent ductus arteriosus:
an angiographic study.
AB - To assess the endothelialization of the coils used to close a persistent ductus
arteriosus (PDA), the present study comprised a review of the follow-up
aortograms and pulmonary angiograms in 25 patients who underwent coil occlusion.
The minimal diameter and the length of the PDA were measured prior to the
procedure, and the shortest distance between the aortic end of the deployed coil
and the aortic end of the PDA was measured after coil deployment. Evidence of
endothelial coverage of the coil was sought on follow-up angiograms performed 6
24 (15+/-5) months later and the factors that determined the thickness of the
endothelial coverage on the aortic end were investigated. Separation of the coil
and the contrast column were detected at the aortic end in all cases and at the
pulmonary end in 18 of 25 cases. The thickness of the separation ranged from 0.4
to 1.3 (0.7+/-0.2) mm at the aortic end and 0.3 to 0.8 (0.6+/-0.2) mm at the
pulmonary end. The length of the ductus and of the ampulla had a significant
positive correlation with the thickness of the aortic end separation. Apparent
endothelial coverage of the coil was completed by 6 months after coil occlusion.
Infective endocarditis or thromboembolism is an unlikely complication once
endothelium covers the implanted coil.
PMID- 10783049
TI - The effect of the atrioventricular interval during atrioventricular sequential
pacing on the hemodynamics in dynamic obstruction of the left ventricular outflow
tract in dogs.
AB - The present study was performed to clarify the mechanism involved in the
reduction of the pressure gradient in the left ventricular outflow tract of
patients with hypertrophic obstructive cardiomyopathy when treated with
atrioventricular (AV) sequential pacing. The effect of AV sequential pacing with
variable AV intervals on the hemodynamics and dyssynchronous wall motion was
experimentally studied using echocardiography in the dynamic obstruction of the
left ventricular outflow tract created by dobutamine infusion in 17 dogs. The
pressure gradient of the left ventricular outflow tract decreased with shortening
of the AV interval during AV sequential pacing. Also, the dyssynchrony time,
defined as the difference in the time between the intraventricular septum and
posterior wall during the systolic phase recorded with M-mode echocardiography,
increased with shortening of the AV interval during AV sequential pacing.
However, very short AV intervals produced a significant decrease in the aortic
pressure and increase in the pulmonary capillary wedge pressure. The dyssynchrony
time showed a positive liner correlation with the percentage reduction in the
pressure gradient of the left ventricular outflow tract (R=0.794, p<0.0001). It
was concluded that dyssynchronous wall motion in the left ventricle was produced
by pacing from the right ventricular apex and resulted in a reduction in the
pressure gradient of the left ventricular outflow tract. Optimization of the AV
interval during AV sequential pacing may play an important role in improving the
hemodynamics in dynamic obstruction of the left ventricular outflow tract.
PMID- 10783050
TI - Effect of angiotensin converting enzyme inhibitor and angiotensin II type 1
receptor antagonist on metabolism and contraction in ischemia-reperfused rabbit
heart.
AB - The effect of angiotensin converting enzyme (ACE) inhibitor, temocaprilat and/or
angiotensin II type 1 (AT1) receptor antagonist, CV-11974 on myocardial
metabolism and contraction during ischemia and reperfusion was examined by
phosphorus 31-nuclear magnetic resonance (31P-NMR) in Langendorff rabbit hearts.
After normothermic 15 min global ischemia, postischemic reperfusion of 60min was
carried out. Temocaprilat and/or CV-11974 were administered from 40 min prior to
the global ischemia. Adenosine triphosphate (ATP), creatine phosphate (PCr),
inorganic phosphate (Pi), intracellular pH (pHi), left ventricular developed
pressure (LVDevP), left ventricular end-diastolic pressure (LVEDP) and coronary
flow were measured. Twenty-eight hearts were divided into 4 experimental groups
consisting of 7 hearts each: group I consisted of controls, group II was perfused
with temocaprilat (10(-6)mol/L), group III was perfused with CV-11974 (10(
6)mol/L), and group IV was perfused with temocaprilat (10(-6)mol/L) in
combination with CV-11974 (10(-6) mol/L). Groups II and III showed a significant
(p<0.05) inhibition of an overshoot phenomenon of PCr during postischemic
reperfusion compared with group I. Group IV also showed a more pronounced
significant (p<0.01) inhibition of the overshoot of PCr during reperfusion
compared with group I. Groups II, III and IV showed a significant (p<0.05)
inhibition of the decrease in ATP during global ischemia (59+/-2, 54+/-3 and 54+/
7%, respectively) compared with group I (45+/-3%). Groups II and IV showed a
significant (p<0.05) early recovery of ATP during reperfusion (81+/-2, 80+/-6%)
compared with group I (71+/-3%) and group II (73+/-2%). Group IV showed no more
significant recovery in ATP than group III. There were no differences in LVDevP,
LVEDP and coronary flow among these groups. In conclusion, temocaprilat in
combination with CV-11974 has significant potential for improving myocardial
energy metabolism during both myocardial ischemia and reperfusion.
PMID- 10783051
TI - Strain difference in rats with experimental giant cell myocarditis.
AB - Immunogenetic mechanisms may be involved in the pathogenesis of myocarditis and
dilated cardiomyopathy. The present study investigated the incidence,
histopathology and histocompatibility characteristics of experimental giant cell
myocarditis in various strains of rats. Experimental giant cell myocarditis was
induced by immunization with porcine cardiac myosin in Lewis (RT-1(l)), Dahl
(DIR/Eis) (RT-1(l)), Fisher (RT-1(lv 1)) rats, but not in Dahl (DIS/Eis) (RT
1(l)) or Brown Norway (RT-1(n)). Myocarditis was most severe in the Lewis rats
and their heart weight/body weight ratio was significantly higher than that of
control rats immunized with Freund's complete adjuvant alone. In conclusion, this
study provides evidence that the expression and severity of experimental giant
cell myocarditis may be determined mainly by genetic factors, including both
major histocompatibility complex genes as well as other genes, which may be
controlled by an immune mechanism.
PMID- 10783052
TI - Anisotropic conduction prolongs ventricular repolarization and increases its
spatial gradient in the intact canine heart.
AB - The effects of the activation sequence on ventricular repolarization and its
spatial gradient were examined in anesthetized open-chest dogs. Unipolar and
bipolar electrograms were recorded from 47 epicardial sites on the anterior left
ventricular wall using a mapping electrode. The local QT interval (QT) and the
activation time (AT) at each site were measured on the unipolar and bipolar
electrograms, respectively. The QT index (QTI) was defined as the QT minus AT
interval, and was used as a measure of local repolarization. QTI was longer at
each site during propagation that was longitudinal (L) (219+/-21 ms) than during
propagation transverse (T) (202+/-22 ms, p<0.001) to the epicardial fiber
orientation or during atrial pacing (165+/-20 ms, p<0.001). During L-propagation,
the QTI shortened as a function of the distance from the stimulus. The spatial
gradient was steeper during T-propagation (p<0.05). Monophasic action potentials
(MAP) were also recorded simultaneously at 4 epicardial sites. The MAP duration
during ventricular pacing was longer than during atrial pacing at sites within
1.5 cm of the pacing site. This difference disappeared at more distant sites and
was attenuated by a simultaneous stimulus from a site symmetrically aligned along
the fiber. These findings indicate that anisotropic conduction prolongs
ventricular repolarization and increases its spatial gradient in the intact
heart. An electrotonic downstream effect appears to be the cause.
PMID- 10783053
TI - Electrogram characteristics indicative of a recurrent conduction site after
ablation of the inferior vena cava-tricuspid annulus isthmus: a study in the
canine blood-perfused atrioventricular preparation.
AB - Analysis of the electrograms recorded along the ablation line can identify a
recurrent conduction site after ablation of the isthmus between the inferior vena
cava (IVC) and tricuspid annulus (TA) for atrial flutter. The present study
examined the relationship between the activation sequence and electrogram
characteristics using a model of recurrent conduction in the isthmus. The canine
heart was isolated (n=8) and cross-circulated with the arterial blood of a
support dog. A plaque electrode was placed at the isthmus, and 42 bipolar
electrograms (filtered and unfiltered) were recorded during pacing at
120beats/min from the lateral right atrium before and after creating a narrow gap
by 2 discontinuous incisions from the TA to the IVC. All bipolar electrodes, with
the cathode in the TA side and the anode in the IVC side, were placed
perpendicular to the TA. Before creating the incisions, the wavefront (WF) from
the pacing impulse traveled uniformly in the isthmus and almost in parallel to
the TA, and the filtered electrogram at each site showed a single potential.
After creating the incisions, the WF propagated through the gap and spread
radially to the area distal to the incisions. In close proximity to the incision
lines opposite to the pacing site, the WF advanced from the gap towards the TA
and IVC perpendicularly to the TA. Filtered electrograms on the incision lines
showed double or split potentials, whereas those on the gap showed a single or
fractionated potential. In unfiltered electrograms recorded from the TA to the
IVC in close proximity to the incision lines opposite the pacing site, reversal
of electrogram polarity was noted at the gap. A single or fractionated potential
between double potentials indicates a gap between lines of conduction block.
Electrogram polarity reversal along the ablation line indicates the presence of 2
opposing WF arising from the gap.
PMID- 10783054
TI - Five-year intra-individual variability in C-reactive protein levels in a Japanese
population-based study: the Jichi Medical School Cohort Study at Yamato, 1993
1998.
AB - C-reactive protein (CRP) is an acute-phase reactant that is related to future
cardiovascular events. However, little is known about the long-term intra
individual stability of CRP in community residents. The 5-year intra-individual
correlation of CRP levels was examined in the Jichi Medical School Cohort Study
in Japan. CRP measurements were obtained in 1993 and in 1998 from 388
presumptively healthy individuals aged 30-69 years at baseline. The Pearson's
correlation coefficient of CRP between baseline and follow-up measurements was
0.43 (95% confidence interval (CI): 0.34-0.51). Additional analyses by sex and
smoking status at baseline revealed similar coefficients. The correlation
coefficient of CRP was lower than that of other classical risk factors, such as
body-mass index (BMI), blood pressure, and total and high-density lipoprotein
(HDL) cholesterol. A subgroup of individuals with higher levels of CRP at both
baseline and follow-up measurements had higher BMI, hemoglobin Alc, and plasma
fibrinogen, and lower levels of HDL-cholesterol than others, even after adjusting
for age, sex, and smoking status in a multiple logistic model. In conclusion, the
stability of CRP levels was statistically significant in a long-term population
based study. A subgroup with higher levels of CRP who had an aggregation of
cardiovascular risk factors was identified by the 2 measurements.
PMID- 10783055
TI - Severe thrombocytopenia caused by digitoxin intoxication in a patient with heart
failure associated with Sjogren's syndrome.
AB - Congestive heart failure (CHF) related to Sjogren's syndrome is extremely rare.
This report concerns a patient who presented with CHF and severe thrombocytopenia
(5,000/microl). Serum concentrations of K, Mg and digitoxin were 3.2mmol/L,
1.4mg/L and 57.2ng/ml, respectively. Digitoxin intoxication was evident,
seemingly evoked by hypokalemia, hypomagnesemia, hepatorenal dysfunction and
hypothyroidism. The severe thrombocytopenia was considered to have been caused by
this intoxication, as it disappeared soon after the digitoxin was discontinued
and potassium was supplemented.
PMID- 10783056
TI - Oozing type cardiac rupture repaired with percutaneous injection of fibrin-glue
into the pericardial space: case report.
AB - Two patients, a 56-year-old man and an 81-year-old woman who were admitted to
hospital because of anteroseptal acute myocardial infarction, were initially
treated successfully with direct percutaneous transluminal coronary angioplasty.
However, both patients later developed sudden cardiogenic shock due to cardiac
tamponade caused by left ventricular free wall rupture (LVFWR). Prompt, life
saving pericardiocentesis was performed, then fibrin-glue was percutaneously
injected into the pericardial space. After the procedure, there was no detectable
pericardial effusion on echocardiography and the hemodynamic state became stable.
The surgical treatment was the standard procedure for LVFWR, but percutaneous
fibrin-glue therapy can also be considered for oozing type LVFWR.
PMID- 10783057
TI - Aorto-coronary dissection during angioplasty in a patient with myxedema.
AB - A 67-year-old man with overt hypothyroidism and medically controlled hypertension
was admitted for coronary angiography because of exertional angina. His
triiodothyronine (T3) and thyroxine (T4) levels had been low for 4 years.
Although signs and symptoms of hypothyroidism were apparent, his
hypercholesterolemia was mild. Coronary angiography revealed an eccentric
stenosis in the distal portion of the right coronary artery and it was decided to
perform angioplasty because his angina had continued in spite of medication. The
dissection appeared at the lesion site after the first nominal inflation, and a
subsequent image disclosed a spiral dissection from the dilated site to the
aortic sinus and peripheral coronary artery. Although emergency stenting could
not prevent the extension near the origin of the brachiocephalic artery, the
false lumen thrombosed and then diminished with conservative therapy. Aorto
coronary dissection is potentially life-threatening and has been recently
reported as a complication during cardiac catheterization procedures. Chronic
hypothyroid insufficiency may be one of the risk factors for this complication.
PMID- 10783058
TI - Interferon treatment for dilated cardiomyopathy and striated myopathy associated
with hepatitis C virus infection based on serial measurements of serum
concentrations of cardiac troponin T.
AB - The present authors recently suggested, on the basis of studies using polymerase
chain reaction (PCR), that hepatitis C virus (HCV) infection is involved in the
etiology or pathogenesis of cardiomyopathic disorders. They have also reported
that the serum concentration of cardiac troponin T is an indicator of ongoing
myocyte degeneration in patients with dilated cardiomyopathy (DCM) and
hypothesized that its serial measurement may be a marker of therapeutic efficacy.
This is the first case report of DCM and striated myopathy, associated with HCV
infection, treated with interferon therapy guided by monitoring of serial serum
concentrations of cardiac troponin T. Positive-plus strands of HCV RNA were found
in the patient's myocardium, as well as plus and minus strands in the quadriceps
muscle specimens. Serum levels of creatine kinase (CK), CK-MB and cardiac
troponin T fell as serum HCV titers decreased during treatment with interferon,
whereas conventional treatment of heart failure had no effect. Monitoring of
serial serum concentrations of cardiac troponin T may allow the earlier diagnosis
and treatment of patients with HCV-associated cardiomyopathy and improve their
clinical course.
PMID- 10783059
TI - Catalytic mechanism of class A beta-lactamase. I. The role of Glu166 and Serl30
in the deacylation reaction.
AB - The tetrahedral intermediate formation process, which is the first step in the
deacylation reaction by class A beta-lactamase, was investigated by the ab initio
molecular orbital method. In this study, benzyl penicillin was used as the
substrate. From the results of our molecular dynamics study of the structure of
beta-lactam antibiotics-beta-lactamase complex, the substrate, Ser70, Lys73,
Ser130, Glu166 and a water molecule for the deacylation reaction were considered
for construction of a model for calculation. The calculation results indicated
that Glu166 plays a role in holding a water molecule, which is necessary for the
deacylation reaction, and that the hydrogen bond network among Lys73Nzeta,
Ser130Ogamma, and the carboxyl group of the beta-lactam antibiotics was formed by
the uptake of beta-lactam antibiotics by beta-lactamase. The activation energy
for this reaction was 33.3 kcal/mol, and it is very likely that the reaction
occurred at body temperature. Subsequent calculation results obtained by using
the model excluding Ser130 and the carboxyl group of the substrate indicated that
the activation energy for this reaction was 40.8 kcal/mol, which is 7.5 kcal/mol
higher than that of the previous reaction. It was found that the hydrogen bond
network plays an important role in decreasing the activation energy for the
tetrahedral intermediate formation reaction. Lys73Nzeta, which is located at the
edge of the hydrogen bond network, played a role in forming a hydrogen bond with
Glu166Oepsilon in order to help the deacylation reaction. The role of amino acid
residues around the active site of class A beta-lactamase was also discussed.
PMID- 10783060
TI - Enzymatic reactivity and anti-tumor activity of 1-(beta-D-arabinofuranosyl)-2
thiocytosine derivatives.
AB - Sixteen derivatives of 1-(beta-D-arabinofuranosyl)-2-thiocytosine (araSC),
including five 5'-esters, three 3'-esters, five N4-amides and three 5'
phosphodiesters, were synthesized and their reactivity to mouse tissue
homogenates, including plasma, liver and intestine, and antitumor activity in
mice bearing P388 cells were measured. The ester derivatives had a potent effect
on the enzyme systems while the amide and phosphodiester derivatives were less
active. The reactivity of ester derivatives was highly dependent on their
chemical structure. The reactivity of amides and phosphodiester derivatives on
mouse plasma and intestinal homogenate was also dependent on the chemical
structure, although their action on intestinal enzymes was very similar. Two of
eight ester derivatives showed considerable antitumor activity in vivo, although
they also showed serious toxicity indicated by a weight loss in the mice. Four
out of five amides and two out of three phosphodiesters showed antitumor
activity, and two were highly effective (>200% in T/C, the ratio of the mean
survival time of the treated group to that of the control group) with only a very
slight weight loss.
PMID- 10783061
TI - A comparison of cellactose with two ad hoc processed lactose-cellulose blends as
direct compression excipients.
AB - Three processed lactose-cellulose blends of similar composition, particle size
and true density were compared as direct compression excipients: one was prepared
by dry granulation, one by extrusion-spheronization, and the commercial product
Cellactose. Differences among their flow properties depended solely on their
different sphericities. Unlike those of the other blends, Cellactose particles
exhibited numerous macropores. The mean yield pressures of all three blends were
similar to those of direct compression lactoses. Cellactose tablets prepared at a
punch pressure that largely eliminated macropores (pores >1 microm) had better
mechanical properties but much poorer disintegration than tablets of the other
blends prepared at the same punch pressure. However, the tensile strength and
disintegration time of Cellactose tablets both fell rapidly as macropore volume
was increased by reducing punch pressure, while the enthalpy of
wetting/dissolution rose. The strength and water-resistance of well-compacted
Cellactose tablets is attributed to the spatial distribution of lactose and
cellulose in Cellactose particles, rather than to beta-lactose content or extra
particular structural features.
PMID- 10783062
TI - Studies on thermal aggregation of bovine serum albumin as a drug carrier.
AB - The irreversible thermal aggregation rate and process of bovine serum albumin
(BSA) were investigated by means of light scattering technique as a function of
temperature. The increasing rate of particle radius was affected by the
aggregation temperature, concentration and the presence of fatty acid. The
particle radius was larger and the aggregation rate was faster for fatty acid
free BSA at higher temperature and concentration. Two thermal aggregation
processes were observed at relatively low temperature and concentration, both for
fatty acid containing (C-BSA) and fatty acid free BSA (F-BSA). The first process
proceeds by an inter-monomer aggregation mechanism, and the second process by
inter-aggregates aggregation. The first process is represented by a power law as
Rhapp proportional to t(z), which is diffusion limited cluster aggregation
(DLCA).
PMID- 10783063
TI - Quantitative analysis of the kinetic constant of the reaction of N,N'
propylenedinicotinamide with the hydroxyl radical using dimethyl sulfoxide and
deduction of its structure in chloroform.
AB - N,N'-Propylenedinicotinamide (Nicaraven) is presently being developed for the
treatment of cerebral stroke including subarachnoid hemorrhage. This drug is
promising because some data suggest it to have an ability to scavenge the
hydroxyl radical under physiological conditions in vivo, while it also has a high
permeability through the blood brain barrier. Using the kinetic constant of the
reaction between the hydroxyl radical and dimethyl sulfoxide, the formula derived
by Babbs and Griffin (Free Rad. Biol. Med., 6 1989) was applied to obtain the
kinetic constant of Nicaraven with the hydroxyl radical using a dimethyl
sulfoxide-xanthine oxidase-hypoxanthine-Fe system, and this yielded the kinetic
constant 3.4x10(9) M(-1) s(-1) (1 M=1 mol dm(-3)) for Nicaraven. Structurally
related compounds were also investigated. The amide group of Nicaraven was thus
found to play an important part in the reaction with the hydroxyl radical.
Methanesulfinic acid, which was obtained from the reaction between dimethyl
sulfoxide and the hydroxyl radical, was found to be stable under this adopted
experimental condition and therefore was used to quantify the kinetic constant of
Nicaraven. The structure of Nicaraven has also been investigated in CDCl3 using
IR spectra, computer calculations and 1H-NMR analysis, and Nicaraven was thus
shown to have an intramolecular hydrogen bond which forms a 7-membered ring that
resembles a part of the 1H-1,4-benzodiazepines. This structure may play an
important role in the penetration through the blood brain barrier.
PMID- 10783064
TI - Effect of the linking position of a side chain in
bis(quinolylmethyl)ethylenediamine as a DNA binding agent.
AB - Two bisquinoline derivatives, N,N'-bis(2-quinolylmethyl)ethylenediamine (2-BQME)
and N,N'-bis(8-quinolylmethyl)ethylenediamine (8-BQME) have been synthesized, and
their ability to bind to duplex DNA was studied. 8-BQME bound to DNA more
strongly than 2-BQME, judging from the extent of increase in the melting
temperature of duplex DNA, the UV-vis spectral change, and ethidium displacement
assay. These compounds exhibited apparent AT-specificity suggesting minor groove
binding in addition to intercalation.
PMID- 10783065
TI - Molecular dynamics simulations of bovine cathepsin B and its complex with CA074.
AB - To promote our better understanding of the dynamic stability of the bovine
cathepsin B structure, which is characterized by an extra disulfide bond at
Cys148-Cys252 from the other species, and of the binding stability of CA074 (a
cathepsin B-specific inhibitor), molecular dynamics (MD) simulations were
performed for the enzyme and its CA074 complex, assuming a system in aqueous
solution at 300 K. The MD simulation covering 400 ps indicated that the existence
of a Cys148-Cys252 disulfide bond increases the conformational flexibility of the
occluding loop, although the conformational stability of the overall structure is
little affected. The structural characteristics of the complex elucidated by X
ray analysis were suggested to be also intrinsic and stable in the dynamic state;
the hydrogen bonding/electrostatic interactions between the main and side chains
of CA074 and the Sn and Sn' subsites of the enzyme were maintained throughout the
MD simulation. Furthermore, the simulation made clear that the binding of CA074
significantly restricted the conformational flexibility of the substrate binding
region, especially the occluding loop, of cathepsin B. Statistical analyses
during the simulation suggest that the selectivity of CA074 for cathepsin B stems
from the tight P1'-S1' and P2'-S2' interactions, assisted in particular by double
hydrogen bonds between the carboxyl two oxygens of the CA074 C-terminus and the
imidazole NH groups of His110 and His111 residues.
PMID- 10783066
TI - Podophyllotoxin aza-analogue, a novel DNA topoisomerase II inhibitor.
AB - The pendant E-ring moiety of the podophyllotoxin aza-analogue 1 that is a potent
inhibitor of microtubule assembly was modified in order to acquire inhibitory
activity of DNA topoisomerase II. The monophenolic analogue 2 did not exhibit
human topoisomerase II inhibition, while the ortho-quinone 3 that was obtained by
oxidation of 2 inhibited its catalytic activity (decatenation) in a dose
dependent manner and stimulated double strand DNA breaks in supercoiled circular
plasmid DNA, resulting in the production of linear DNA. These results showed that
the topoisomerase II inhibition of the ortho-quinone 3 is due to stabilization of
the topoisomerase II-DNA covalent binary complex. On the other hand, the ortho
quinone 3 did not inhibit the relaxation process of supercoiled DNA by
topoisomerase I at concentrations up to 400 microM, nor was intercalation
observed in unwinding measurements of 3. Therefore, the ortho-quinone 3 was shown
to be a novel nonintercalative topoisomerase II specific inhibitor that
stabilizes the cleavable complex. The present results suggest that the 4'-free
hydroxyl group on the E-ring and the sugar moiety on the C-ring are not a
prerequisite for topoisomerase II inhibition by podophyllotoxin derivatives.
PMID- 10783067
TI - Novel potassium channel opener prodrugs with a slow onset and prolonged duration
of action.
AB - (-)-(3S,4R,1'R,6'S)-4-(4-Benzyl-5-oxo-3,4-diazabicyclo[4.1.0]hept-2-en-2 -yloxy)
3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-carbo nitrile and its
derivatives with a modified benzyl group were synthesized with the objective of
discovering novel ATP-sensitive potassium channel openers (PCOs) with a slow
onset of action and a reduced tendency to induce tachycardia. Among the compounds
synthesized, 4-(2-chlorobenzyl) derivative 5bB had potent hypotensive activity in
spontaneously hypertensive rats (SHRs). In addition, compound 5bB showed the
desired pharmacological profile with a slow onset and long duration of action and
induction of only mild tachycardia. Compound 5bB was found to be quantitatively
metabolized in rats to give active des-2-chlorobenzyl derivative 6B. These
results suggest that the incorporation of an N-benzyl group is a useful method
for the preparation of prodrugs, the function of which is to delay the onset and
prolong the duration of action of the active substance.
PMID- 10783068
TI - Methyl quadrangularates A-D and related triterpenes from Combretum quadrangulare.
AB - From the MeOH extract of leaves of Combretum quadrangulare, fifteen new
cycloartane-type triterpenes, methyl quadrangularates A-D (1-4) and N-P (8, 6,
12), methyl 24-epiquadrangularate C (5), quadrangularic acid E (9), 23
deoxojessic acid (10), 1-O-acetyl-23-deoxojessic acid (11), quadragularols A (7)
and B (13) and norquadrangularic acids B (14) and C (15) were isolated together
with two known cycloartane-type triterpenes, methyl 23-deoxojessate (16) and
4beta,14alpha-dimethyl-5alpha-ergosta-9beta++ +,19-cyclo-24(31)-en-3beta-hydroxy
4alpha-carboxylic acid (17). Betulinic acid (18), beta-sitosterol (19),
kamatakenin (20), isokaempferide (21), 5,7,4'-trihydroxy-3,3'-dimethoxyflavone
(22) and 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (23) were also obtained from the
same extract. The structures of the new compounds were elucidated on the basis of
spectral analysis and chemical conversions. All the isolated compounds were
tested for their cytotoxicity towards highly liver metastatic murine colon 26-L5
carcinoma cells, and the cycloartane-type triterpenes showed various degrees of
cytotoxicity, whereas all the flavonoids possessed strong cytotoxicity with ED50
values equal to or less than 6 microM.
PMID- 10783069
TI - Structures of 4-aryl-coumarin (neoflavone) dimers isolated from Pistacia
chinensis BUNGE and their estrogen-like activity.
AB - Activity-guided fractionation of twigs of Pistacia chinensis resulted in the
isolation and characterization of two novel ingredients as potent estrogen
agonists. On the basis of spectral analysis and comparison with a related
compound their structures were elucidated as 3,3''-dimers of 4
aryldihydrocoumarins (3,4-dihydro-4-(4'-hydroxyphenyl)-7-hydroxycoumarin)
differing only in the stereochemical disposition of the linkage between the two 4
arylcoumarin moieties. These compounds are the first examples of bis-flavonoids
which have been proven to possess estrogen-like activity.
PMID- 10783070
TI - 4-Sulfenyl-2-carbamoyl-4-isoxazolin-3-ones: biological isostere to 4-chloro-2
carbamoyl-4-isoxazolin-3-ones.
AB - 4-Sulfenyl-2-carbamoyl-4-isoxazolin-3-ones (4) were designed on the basis of
biological isosterism and prepared in four steps. Some of these compounds showed
sufficient pre-emergent herbicidal activities against various kinds of weeds.
Among the synthesized compounds, 2-(N-(4-chlorophenyl)-N-isopropylcarbamoyl)-4
ethylthio-5-methyl-4 -isoxazolin-3-one (4cd) exhibited the most promising
activity.
PMID- 10783071
TI - Cardenolide and oxypregnane glycosides from the root of Asclepias incarnata L.
AB - Twenty-nine new oxypregnane glycosides were obtained along with two known
cardenolides, frugoside and gofruside, and three known 12-O-acylated pregnane
glycosides from the roots of Asclepias incarnata L. (Asclepiadaceae). By detailed
studies of the 1H- and 13C-NMR spectra, the structures were determined to be tri-
to penta glycosides of isolineolon, 12-O-acetyllineolon, ikemagenin, 12-O
benzoylisolineolon, and two new 12-O-acylated pregnanes.
PMID- 10783072
TI - Studies on the reaction of benzo[x]quinoline N-oxides (X = f, h, and g) with
methylsulfinyl carbanion using the semi-empirical molecular orbital method.
Liberation of the N-oxide group.
AB - The mechanism of the liberation reaction of the N-oxide group has been studied
and compared with the methylation reaction using a semi-empirical molecular
orbital PM3 method. By comparing the calculated values of Gibbs free energy of
activation, we can determine whether a liberation reaction or methylation
reaction occurs.
PMID- 10783073
TI - Improved synthesis of paroxetine hydrochloride propan-2-ol solvate through one of
metabolites in humans, and characterization of the solvate crystals.
AB - Paroxetine, a potent and selective inhibitor of 5-hydroxytryptamine (serotonin)
uptake, was prepared through a piperidine derivative, which was reported to be
one of the paroxetine metabolites in humans. Thus, the piperidine derivative was
converted to its N-tert-butoxycarbonyl (N-Boc) derivative, which was then
converted to N-Boc paroxetine. Paroxetine hydrochloride propan-2-ol (isopropyl
alcohol (IPA)) solvate crystals were directly obtained from the N-Boc paroxetine
by adding hydrogen chloride to the N-Boc paroxetine IPA solution. The amount of
IPA content in the crystals was reduced by drying with a continuous change of
powder X-ray diffraction patterns. Other characterizations of the solvate
crystals were also conducted.
PMID- 10783074
TI - Structural and spectral characteristics of the electrogenerated
tetracyanoethylene dianion.
AB - Structural and spectral characteristics of the electrogenerated
tetracyanoethylene dianion (TCNE2-) were experimentally and theoretically
examined. Spectroelectrochemistry of TCNE gives the spectra of TCNE2- in CH3CN at
220 nm, and in CH2Cl2 at 300 nm. These spectral characteristics are well
explained by CIS/6-31G(d) and semiempirical CNDO/S-CI calculations. The bands in
CH3CN and in CH2Cl2 are assigned to the degenerate 1E<--1A1 transition at the D2d
structure and the 1B2u<--1Ag transition at the D2h structure, respectively. The
rotation barrier of the C=C bond in TCNE2- is estimated by Hartree-Fock (HF),
second-order Moller-Plesset perturbation (MP2) and fourth-order MP (MP4)
calculations with 6-31G(d), 6-31+G(d) and 6-311+G(d) basis sets as 42-51 kJ mol(
1). The D2d structure is most stable, and the D2h structure represents the
transition state of the internal rotation. The calculations reveal that the two
electron addition to the antibonding LUMO of TCNE causes an easy rotation around
the C=C bond of TCNE2- characterized by the formal single bond. These results
show that TCNE2- preferentially adopts D2d and D2h structures in solvents
depending upon the solvent nature by virtue of the easy rotation around the C=C
bond.
PMID- 10783075
TI - Megastigmane, benzyl and phenethyl alcohol glycosides, and 4,4'-dimethoxy-beta
truxinic acid catalpol diester from the leaves of Premna subscandens MERR.
AB - Extensive isolation work on the n-BuOH-soluble fraction obtained from the leaves
of Premna subscandens, collected on Ishigaki island, Okinawa, afforded six
compounds. Two were identified as megastigmane glucosides, 7-(3,5-dihydroxy-1,1,5
trimethylcyclohexylidene)-9-methylprop++ +-8-enyl 9-O-beta-D-glucopyranoside and
3-hydroxy-5,6-epoxy-beta-ionol 9-O-beta-D-glucopyranoside. The structures of the
remaining four new compounds were elucidated to be a 2'-O-beta-D-apiofuranosyl
derivative of 3-hydroxy-5,6-epoxy-beta-ionol 9-O-beta-D-glucopyranoside, named
premnaionoside, benzyl alcohol beta-D-(2'-O-beta-D-xylopyranosyl)glucopyranoside,
phenethyl alcohol beta-D-(2'-O-beta-D-glucopyranosyl)glucopyranoside, and 4,4'
dimethoxy-beta-truxinic acid catalpol diester by spectroscopic analyses.
PMID- 10783076
TI - Glochidionolactones A-F: butenolide glucosides from leaves of Glochidion
zeylanicum (GAERTN) A. JUSS.
AB - From the leaves of Glochidion zeylanicum, six new butenolide glucoside, named
glochidionolactones A-F, were isolated along with a known related compound,
phyllanthurinolactone. The structures of glochidionolactones A-D and F were
elucidated mainly by spectroscopic analyses. The absolute stereochemistry of
glochidionolactone E was established by X-ray crystallographic analysis.
PMID- 10783077
TI - Synthesis of tricyclic compounds as steroid 5alpha-reductase inhibitors.
AB - A series of 4-phenoxybutyric acid derivatives attached to a tricyclic skeleton
were prepared and evaluated as 5alpha-reductase inhibitors. Structure activity
relationships for these compounds in terms of rat epididymis (type 2) 5alpha
reductase inhibitory activities reveal that 1) the substitution pattern at the 11
position of dibenz[b,e]oxepin influenced potency, 2) higher lipophilicity of the
tricyclic skeleton improved potency, whereas the existence of a basic nitrogen
atom in this skeleton was detrimental to potency, and 3) isobutyl substitution at
the 8 positon of the azepine skeleton was tolerated. Among the tricyclic
compounds studied, 4-[3-[5-benzyl-8-(2-methyl)propyl-10,11
dihydrodibenz[b,f]azepine- 2-carboxamido]phenoxy]butyric acid (26) was the most
potent inhibitor of rat type 2 5alpha-reductase at 0.1 microM.
PMID- 10783078
TI - Cholestane glycosides from Solanum abutiloides. III.
AB - Four new cholestane glycosides, named abutilosides D (1), E (2), F (3) and G (4),
were isolated from the fresh roots of Solanum abutiloides. By chemical and
spectroscopic evidence, their structures were elucidated as 26-O-beta-D
glucopyranosyl 3beta,16alpha,26-trihydroxy-5alpha-cholestan-22-one 3-O-beta-D
xylopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->4)-beta-D- glucopyranoside and
its desxylosyl compound (1 and 3, respectively), 26-O-beta-D-glucopyranosyl
3beta,16alpha,26-trihydroxycholest-5-en-22-one 3-O-beta-D-xylopyranosyl-(1-->2)
alpha-L-rhamnopyranosyl-(1-->4)-beta-D- glucopyranoside and its desxylosyl
compound (2 and 4, respectively). These compounds were regarded as precursors of
a dormantinone type compound on a hypothetical pathway of steroid biogenesis.
PMID- 10783079
TI - Butyrolactones from Aspergillus terreus.
AB - In the process development of lovastatin using Aspergillus terreus DRCC 152 in
solid state fermentation, we have isolated a new butyrolactone-IV (3) along with
the previously reported butyrolactone-I (1) and butyrolactone-II (2) produced
under submerged conditions. The structure of compound 3 has been characterized as
3-hydroxy-5-[2-(1-hydroxy-1-methylethyl)-2(R)-2,3-dihydro-benzo[b]furan- 5
ylmethyl]-4-(4-hydroxyphenyl)-5-methoxycarbonyl-(5R)-2,5-dihydro-2 -furanone on
the basis of spectroscopic studies. The absolute stereochemistry has been
determined by single crystal X-ray diffraction studies. The cytotoxic and
antibacterial activities of these compounds were determined.
PMID- 10783080
TI - Efficient synthesis of a key intermediate of DV-7751 via optical resolution or
microbial reduction.
AB - Two efficient and practical methods of synthesis of the C-10 substituent of DV
7751 (1), a novel quinolone carboxylic acid, were established. The first method
utilizes an optical resolution of racemic 8-amino-6-benzyl-6-azaspiro[3.4]octane
(13), while the second employs an enantioselective microbial reduction of 6
benzyl-5,8-dioxo-6-azaspiro[3.4]octane (8b). The enantiomeric excess of (S)-8
amino-6-benzyl-6-azaspiro[3.4]octane (11) with each method of synthesis is
greater than 96%.
PMID- 10783081
TI - Differentiation inducing activities of isocoumarins from Hydrangea Dulcis Folium.
AB - In the course of searching for differentiation inducers against leukemic cells
from plants, we have recognized the differentiation inducing activities of the
methanolic extract of Hydrangea Dulcis Folium. Activity guided separation of the
extract was carried out using M1 cells, and seven isocoumarins were isolated as
active substances. These isocoumarins showed the activities at the concentration
of 100 microM and non-cytotoxic effects even at 300 microM.
PMID- 10783082
TI - Studies on the constituents of solanaceous plants. (46). Steroidal glycosides
from the fruits of Solanum anguivi.
AB - Three new glycosides named anguiviosides A-C were isolated from the fruits of
Solanum anguivi and characterized as follows:3-O-beta-chacotrioside (1), 3-O-[4-O
maloyl-alpha-L-rhamnopyranosyl(1-->2)]-alpha-L-rhamnopyra nosyl(1-->4)-beta-D
glucopyranoside (2) and 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-xylopyranosyl(1
->3)]-beta-D-+ ++glucopyranoide (3), of (25R,26R)-spirost-5-en-3beta,26-diol.
PMID- 10783083
TI - Stereoselective reactions. XXXII. Enantioselective deprotonation of 4-tert
butylcyclohexanone by fluorine-containing chiral lithium amides derived from 1
phenylethylamine and 1-(1-naphthyl)ethylamine.
AB - Enantioselective deprotonation of 4-tert-butylcyclohexanone was examined using 1
phenylethylamine- and 1-(1-naphthyl)ethylamine-derived chiral lithium amides
having an alkyl or a fluoroalkyl substituent at the amide nitrogen. The lithium
amides having a 2,2,2-trifluoroethyl group on the amide nitrogen are easily
accessible in both enantiomeric forms, and were found to induce good
enantioselectivity in the present reaction.
PMID- 10783084
TI - Two novel C-glycosides of aureolic acid repress transcription of the MDR1 gene.
AB - In the search for compounds which repress MDR1 gene expression, two novel aryl C
glycosides were isolated from a broth of Streptomyces sp. They had the
characteristic structure of a dideoxy-carbohydrate (oliose or olivose) linked
directly to chromomycinone, an aglycone of aureolic acids. Further investigation
revealed that they were artifacts yielded from an aureolic acid, mithramycin.
Acid and methanol were necessary to yield the C-glycosides. This reaction would
contribute to the design of useful aryl C-glycosides.
PMID- 10783085
TI - The controlled release of a drug from biodegradable chitosan gel beads.
AB - Chitosan (CS) forms a gel in solutions with a pH above 12, and the gelation
occurs at pH of about 9 in 10% amino acid solutions. In this paper, we
investigated the enzymatic degradation and the drug release profile of this novel
CS gel beads. The degradability of the CS gel beads was affected by the CS
properties, e.g. the degree of deacetylation. The release of prednisolone (PS),
as a model drug, from the CS gel beads was sustained significantly compared with
the gel prepared with NaOH only. However, the release was not able to be
sustained by the increment of NaOH concentration in the solution employed for the
preparation of CS gel beads. We also investigated the control of drug release
from CS gel beads by application of a complex formed between chondroitin sulfate
(Cho) and CS. The release of PS from the CS gel beads treated with Cho was
prolonged, and the release pattern was not affected by the treatment time. The
time to 50% drug release was about 5 min with PS powder, about 200 min in CS gel
beads with 10% glycine (Gly) (pH 9.0), and about 330 min in the CS gel beads with
10% Gly (pH 9.0) treated with Cho. Thus CS gel beads appear promising as a
vehicle for sustained drug delivery, and the degradation of CS gel beads may be
controlled by the degree of deacetylation of CS.
PMID- 10783086
TI - Four new furanone-coumarins from Clausena excavata.
AB - Four new furanone-coumarins, clauslactones-N (4), -O (5), -P (6) and -Q (7) were
isolated from the leaves and twigs of Clausena excavata BURM. f. (Rutaceae)
collected in Indonesia and their structures were elucidated by spectroscopic
analysis.
PMID- 10783087
TI - Temperature-induced crystallization and compactibility of spray dried composite
particles composed of amorphous lactose and various types of water-soluble
polymer.
AB - The purpose of this study was to investigate the temperature-induced
crystallization and the compactibility of the composite particles containing
amorphous lactose and various types of polymers. The composite particles were
prepared by spray-drying an aqueous solution of lactose and various types of gel
forming water-soluble polymers at various formulating ratios. The stabilizing
effect of hydroxypropylcellulose (HPC) and polyvinyl pyrrolidone (PVP) on
amorphous lactose in the composite particles was smaller than that of sodium
alginate in comparing at the same formulating ratios. The difference in the
stability of amorphous lactose in the composite particles was attributed to the
difference in the glass transition temperature (Tg) of the composite particles
caused by the polymers formulated. The tensile strength of compacted spray-dried
composite particles containing the polymers was higher than commercial lactose
for direct tabletting (DCL21). The tensile strength of the composite particles
was increased with an increase in water content in the particles. The difference
in compactibility of the composite particles containing the different amount of
polymer and water could be explained by the difference in Tg of the particles.
PMID- 10783088
TI - An efficient synthesis of the anti-asthmatic agent T-440: a selective N
alkylation of 2-pyridone.
AB - 6,7-Diethoxy-1-[1-(2-methoxyethyl)-2-oxo-1,2-dihydropyridin- 4-yl]naphthalene-2,3
dimethanol [T-440, (1)] is a potential anti-asthmatic agent based on selective
phosphodiesterase 4 inhibition. It was necessary for the further evaluation of 1
to develop an efficient synthetic route for 1, especially the construction of the
1-(2-methoxyethyl)-2-pyridone moiety. We examined an N-selective alkylation of
pyridone derivative (2) in basic media. 2-Methoxyethylation of 2 with 2
methoxyethyl iodide utilizing LiH as the base gave predominantly an N-alkyl
pyridone derivative (3a) in 82% yield (N/O-alkylation=92/8), which is compatible
with an ab initio calculation of transition-state structures for the methylation
of 2-pyridone. Single crystallization of a crude mixture of 3a and 4a furnished
pure 3a, which is a key synthetic intermediate of 1.
PMID- 10783089
TI - An outcome-based study of aesthetic surgery in a clinic setting.
AB - Previous studies have addressed the difficulties in training residents in
aesthetic surgery. The purpose of this study is to analyze patient satisfaction
with cosmetic surgery at an inner city teaching hospital as well as to evaluate
referral patterns. The patients included in this study underwent aesthetic
surgical procedures through the Kings County Hospital Plastic Surgery Clinic
(KCHC) from January 1, 1997, to June 30, 1998. Patients were informed that the
procedure would be performed by a plastic surgery resident with attending
supervision. Data were obtained in a retrospective fashion using telephone
surveys. Fifty-five patients participated in the study, which accounted for 68
aesthetic procedures. Sixty percent of patients considered the results of surgery
as excellent or good. On a patient satisfaction scale from 0 (unhappy) to 10
(exceedingly happy), patients' self-reporting average was 6.59. This mean value
may not be completely indicative of patient satisfaction. Eighty-nine percent of
patients would refer a friend and 78% of patients would have the same procedure
performed again. Sixty-nine percent of the patients had been referred by past
KCHC patients. All of these numbers tend to convey a higher degree of patient
satisfaction. The results of the study appear to convey the importance of
developing residents' ability to accurately explain to patients the anticipated
results of aesthetic surgery.
PMID- 10783090
TI - Replantation of avulsed scalps and secondary aesthetic correction.
AB - Five patients with avulsed scalps were treated with replantation between 1992 and
1998. All patients were women age 20 to 36 years. The percentage of the avulsed
scalp ranged from 50% to 100% of the whole scalp. The vessels chosen for
anastomosis were the superficial temporal artery, occipital artery, and
superficial temporal vein. A vein graft harvested from the cephalic vein of the
forearm was performed on the venous and arterial sides in 1 patient. Two patients
experienced complete survival of the replanted scalp. Three patients showed 40%,
50%, and 80% survival areas, with the remaining defects resurfaced as split
thickness skin grafts. Six months later, the scar areas in the last 3 patients
were reconstructed with an expansion of the normal or replanted scalp. The follow
up period ranged from 1 to 7 years. In 4 patients a partial return of sensation
in the replanted scalp and motor function of the frontalis muscle were observed.
All patients were satisfied with the aesthetic results of their surgery.
PMID- 10783092
TI - Neural anatomy of the radial forearm flap.
AB - Typically the lateral antebrachial cutaneous nerve alone is used to innervate the
radial forearm free flap when a sensate flap is required. The authors desired, by
means of fresh cadaveric microdissections and by means of local anesthetic
injections in living subjects, to map the sensory nerve territories of this flap.
Eight radial forearm flaps were elevated and the medial antebrachial cutaneous
nerve (MABC), lateral antebrachial cutaneous nerve (LABC), and superficial radial
sensory nerve (SRSN) were dissected with the aid of an operating microscope (2.5
10x) and traced to their dermal insertions. In the injection study, the MABC,
LABC, and SRSN in eight forearms of 4 subjects were blocked sequentially with 2%
lidocaine injections. The resulting sensory deficit from each injection was
mapped on the skin and superimposed on the marked radial forearm flap territory.
Distribution of the three dissected nerve regions and the sensory deficit after
injection were determined by digital images and computer analysis. During flap
dissections, mean nerve distributions of total flap area were as follows: LABC,
61.8% (range, 48.3-71.6%); MABC, 33.8% (range, 30.5-38.9%); and SRSN, 34.6%
(range, 26.8-44.1%). After nerve block the mapped sensory areas were as follows:
LABC, 62.3% (range, 44.5-88.5%); MABC, 19.6% (range, 8.0-35.8%); and SRSN, 19.5%
(range, 9.9-26.3%). At least 40% of the total flap area was not innervated by the
LABC as identified both by nerve dissection and sensory local anesthetic
blockade. By including the LABC, MABC, and SRSN in the radial forearm flap, both
the theoretical and the clinically determined useful sensory innervation of the
radial forearm flap potentially would be increased.
PMID- 10783091
TI - Distally based fasciocutaneous flap of the calf for cutaneous coverage of the
lower leg and dorsum of the foot.
AB - Cutaneous injuries of the inferior third of the leg and dorsum of the foot
represent a great challenge for plastic surgeons. The poor vascularization and
subsequent poor healing encountered in these regions demand detailed knowledge of
the local anatomy to select the best surgical alternative for each patient. In
patients in whom local or free muscular flaps are not suitable, the
fasciocutaneous flaps seem to be a good alternative. The distal pedicled
fasciocutaneous flap of the calf was used to cover skin defects of the leg and
foot in 22 patients. In 4 patients the authors designed an island flap to prevent
a large defect in the donor area and to decrease the time of hospitalization and
recovery of the patient. In a severe defect, the flap was used as a cross-leg
flap. The results were satisfactory because the flap provided stable coverage for
different defects with few complications. The island flap is a good option for
achieving a better aesthetic result and can be used in select patients.
PMID- 10783093
TI - Surgical treatment of urethral fistulas following hypospadias repair.
AB - Development of urethral fistulas is one of the most common late complications of
hypospadias surgery. A total of 161 male patients who had 186 urethrocutaneous
fistulas were first classified according to the fistula classification of Horton
and colleagues and then treated with three types of procedures: simple closure,
local rotation flaps, or tube graft reconstruction. With initial surgical
intervention, 156 of 186 fistulas were treated successfully. The remaining 30
fistulas (16.1%) recurred during the follow-up period. In the recurrent cases,
immediate closure was not preferred, and an average of 6 months was waited before
considering any additional surgical attempt. Distal cases had a higher failure
rate, and the simple closure technique failed to show a success rate as high as
local flap or tube graft repair. The high recurrence of distal cases was
attributed mainly to the lack of adequate soft tissue adjacent to the fistula,
which is vital for safe closure. In addition, the traction effect of erection on
the skin and urethra, which is more prominent distally than proximally, is also
believed to play an additive role. To increase success, the selection of
appropriate treatment modality and customization of techniques for each patient
cannot be overemphasized. However, the authors conclude that careful presurgical
assessment of the patient, a 6-month delay before any secondary surgical attempt,
inversion of the urethral mucosa, avoidance of any overlapping suture lines,
urinary diversion proximal to the repair site for 5 to 11 days, and usage of
thin, absorbable suture materials are the main criteria that should be met for a
satisfactory hypospadias fistula repair.
PMID- 10783094
TI - Periprosthetic breast capsules contain the fibrogenic cytokines TGF-beta1 and TGF
beta2, suggesting possible new treatment approaches.
AB - Periprosthetic breast capsules composed of fibrotic collagenous material with
increased collagen production are not dissimilar to other fibrotic conditions
occurring in other organs. Fibrosis in the lung, liver, kidney, and skin has been
associated with overproduction of the fibrogenic isoforms of transforming growth
factor beta (TGF-beta1 and TGF-beta2). If periprosthetic breast capsules
contained high levels of these cytokines, possibly new treatment approaches for
capsular contraction could be proposed. Breast implant capsules of 35 patients
harvested at the time of explantation were examined using indirect
immunohistochemistry. Staining intensity for TGF-beta1 and TGF-beta2 was measured
in all specimens. Immunohistochemical staining for TGF-beta1 and TGF-beta2
revealed that these two cytokines were present in all capsules analyzed. Minimal
TGF-beta1 and TGF-beta2 were found in normal breast tissue. Levels of control vs.
TGF-beta1 and control vs. TGF-beta2 were significant (p = 0.004 and p < 0.001
respectively). The presence of TGF-beta isoforms that are known to be fibrogenic
may suggest new therapeutic approaches, which are being investigated for other
fibrotic conditions.
PMID- 10783095
TI - Skin flap prefabrication using acellular dermal matrix and cultured keratinocytes
in a porcine model.
AB - In an effort to minimize the amount of autogenous tissue that is sacrificed in
using a random skin flap, the authors, in a porcine model, implanted 3.0 x 7.0-cm
(median thickness, 1 mm) sheets of commercially available nonmeshed acellular
dermal matrix (AlloDerm) subcutaneously. After a vascularization period of 2
weeks, the implants were elevated and used as turnover dermal flaps to cover
adjacent 3.0 x 3.0-cm full-thickness skin defects. Sheets of autogenous cultured
keratinocytes were used for epithelium. The AlloDerm-cultured keratinocyte
complex flaps healed without any complications. Measurements for percent
contraction of the wound to determine the suitability of AlloDerm as a dermal
flap showed that the wounds had contracted an average of 18 +/- 3.6% at 24 weeks.
Histological evaluation revealed multilayered keratinocytes and indurations
between the cultured keratinocytes and AlloDerm. Fibroblast infiltration and the
presence of luminal spaces surrounded by capillary endothelium characteristic of
neovascularization of the matrix were also noted. This preliminary study may form
the basis for developing other types of prefabricated flaps using AlloDerm and
cultured keratinocytes.
PMID- 10783096
TI - Comparison of immune response to nerve allograft segments in fetal and adult
rabbits: a histological study.
AB - Fetuses, as opposed to adults, are immature immunologically and it has been
proved that they can tolerate allograft materials much better than adults. In
this study the rejection phenomenon of nerve allografts was compared
histologically in fetuses and adults. The study was performed in 60 New Zealand
rabbits (30 pregnant and 30 nonpregnant), and allograft nerve segments were
obtained from Chinchilla rabbits. The animals were divided into fetal and adult
groups. Each group was studied at various time periods. Nerve allografts were
placed under the panniculus carnosus in the interscapular region of the fetuses
and adults. In both fetal and adult groups, the nerve allograft segments were
assessed histologically after 1, 7, and 30 days. The criteria used during the
evaluation were the degenerative findings in the myelinated axons (large, medium,
and small axons), changes in Schwann's cells, and the quantity of infiltrating
cells. The changes were graded microscopically from 0 (no change) to 3 (severe
destruction and cellular infiltration). Cellular infiltration was more extensive
in the adult groups than in the fetal groups. Earlier fetal groups showed minimal
infiltration, but the response became more extensive in the later fetal groups.
This is probably related to the removal of the fetuses from their intrauterine
environment. When comparing fetal and adult groups, the results were significant
(p < 0.05). The fetuses tolerated the nerve allograft segments better than the
adults. This may be related to the immature immune system of the fetuses.
PMID- 10783097
TI - Platelet supernatant promotes proliferation of auricular chondrocytes and
formation of chondrocyte mass.
AB - Recently proposed procedures for in vitro generation of new cartilage may be
difficult to perform in humans because so many chondrocytes are needed for tissue
engineering. In this study the authors investigated new, efficient, low-cost
techniques for the isolation and culture of chondrocytes from the ear cartilage
of the rabbit. They performed a low-density monolayer culture with a low
concentration (0.5%, 1%) of human platelet supernatant and observed cell
proliferation (seeding efficiency, deoxyribonucleic acid synthesis), matrix
synthesis (glycosaminoglycan synthesis), and the expression of type I and type II
collagen (reverse transcriptase polymerase chain reaction). Seeding efficiency
was increased in 1% of platelet supernatant-treated cultures by two to three
times compared with untreated controls. One percent platelet supernatant had
increased the incorporation of [3H]-thymidine by 1.9 to 2.5 times at 72 hours
compared with controls. Glycosaminoglycan synthesis was increased in platelet
supernatant-treated chondrocytes at 96 hours compared with controls. Chondrocytes
treated with 1% platelet supernatant showed a decreased expression of the type II
collagen gene. Supplementation with a high concentration (10%) of the platelet
supernatant provided the conditions for in vitro chondrocyte mass formation.
These results indicate that proliferation and matrix synthesis of auricular
chondrocytes is stimulated by a low concentration of platelet supernatant. On the
other hand, chondrocytes were immobilized by a high concentration of platelet
supernatant. Platelet supernatant may be useful as an inexpensive autologous
source of multiple growth factors to enhance chondrocyte proliferation, and also
may play the role of scaffold for chondrocytes. Additional investigation is
underway to generate culture conditions that promote the differentiation as well
as the proliferation of chondrocytes.
PMID- 10783099
TI - Transsacral usage of a pure island TRAM flap for a large sacral defect: a case
report.
AB - A pedicled transverse rectus abdominis musculocutaneous (TRAM) flap was used to
reconstruct a large sacral defect retroperitoneally. Muscle and superiorly
located skin were elevated on the deep inferior epigastric pedicle. The flap was
transposed retroperitoneally from the abdominal wall to the sacral region of the
patient. The selection criteria for this particular flap are discussed and
compared with other reconstructive choices.
PMID- 10783098
TI - Filleted toe flap for chronic forefoot ulcer reconstruction.
AB - Chronic plantar and dorsal forefoot ulcer may result from injury, structural
deformity, and abnormal sensation or circulation. It is not uncommon that the
distal portion of the affected toes is deficient functionally in these patients.
A filleted toe flap from the expendable functionless toe can provide a durable,
stable, and sensate skin flap of 4 to 5.5 cm for coverage of the forefoot defect.
In this report, five cases of dorsal forefoot defects and four cases of plantar
forefoot defects due to ischemia (N = 3), trophic change (N = 2), and diabetes (N
= 4) were treated with filleted toe flaps. One flap failed due to postoperative
deep infection. The other eight filleted toe flaps survived but 2 patients
underwent secondary amputations 7 months and 2 two years later because of
secondary diabetic foot infections.
PMID- 10783100
TI - Combined pedicled flaps for grade IIIB tibial fractures in children: a report of
two patients.
AB - Severe open tibial fractures in children are associated with notable morbidity
and require early aggressive management to ensure a successful outcome. Free
flaps are currently the gold standard in distal extremity reconstruction in which
large soft-tissue defects exist, as is often the case with grade IIIB fractures.
In severe lower limb trauma, however, free flaps are associated with a relatively
high risk of failure, particularly when definitive soft-tissue coverage is
delayed. Alternative methods of soft-tissue reconstruction may, therefore,
occasionally require consideration. The authors describe the combined use of
three pedicled flaps to attain soft-tissue coverage in 2 children with grade IIIB
tibial fractures. These three flaps are individually in common use for lower limb
soft-tissue coverage, are simple to raise, and in combination can cover extensive
soft-tissue defects of the lower extremity. The major vascular axes of the limb
are not sacrificed; however, the aesthetic result is modest.
PMID- 10783101
TI - Reverse radial forearm flap as a source of soft tissue and blood supply for thumb
reconstruction.
AB - Soft-tissue deficiency is sometimes a major problem in thumb reconstructive cases
with toe-to-thumb transfer. In the patient presented, a reverse radial forearm
flap was used to provide a vascular pedicle for anastomosis with the second toe
vessels. The flap also provided soft-tissue coverage for the metatarsal bone of
the transferred toe. The radial artery and concomitant vein were used for the
dorsalis pedis artery and vein anastomosis. The skin island of the forearm flap
was wrapped around the transferred metatarsal bone. Using this technique, two
limiting problems in toe-to-hand transfers were solved at the same time. In the
crushed hand, sometimes it is not possible to find enough soft tissue and a good
vascular pedicle for a new thumb, and this option seems to be a reasonable
choice.
PMID- 10783102
TI - Aggressive basal cell carcinoma of the temporal region in a patient with Gorlin
Goltz syndrome.
AB - Gorlin-Goltz syndrome is an autosomal dominant disorder with variable penetration
characterized primarily by five major findings: multiple basal cell carcinomas
presenting at a young age, pits on the palms and soles, skeletal abnormalities,
jaw cysts, and ectopic calcification of the falx cerebri and other structures.
When the basal cell carcinomas are located in the head and neck there is a high
risk of invasion of deep structures if early and radical treatment is not
performed. The authors present a 59-year-old man affected by basal cell carcinoma
in the context of Gorlin-Goltz syndrome. Although patients with this syndrome can
present aggressive basal cell carcinomas, it is unusual to find them involving
the craniofacial bones. In this patient the basal cell carcinoma involved the
middle ear, the intrapetrous aspect of the facial nerve, and the dura mater. The
reconstruction of a wide three-dimensional defect, in which the brain was
exposed, was achieved with local flaps and a free musculocutaneous rectus
abdominis flap. Factors affecting reconstruction in the lateral cranial base are
discussed.
PMID- 10783103
TI - Salvage of ear replantation using the temporoparietal fascia flap.
AB - The authors report a case involving a 46-year-old man who sustained a traumatic
amputation of approximately 60% of his ear from a human bite. The ear was
replanted microsurgically without the benefit of venous anastomosis. Blood
transfusion was not required despite the use of leech therapy and systemic
anticoagulation. The replantation appeared to be a success at the time of his
discharge from the hospital, but during the late postoperative period the
replanted ear became progressively necrotic. The failing ear replantation was
rescued successfully with the use of temporoparietal fascia flap reconstruction.
PMID- 10783104
TI - Large myxofibroma of the mandible treated with segmental mandibular resection and
vascularized fibular graft.
AB - This report summarizes a case of large myxofibroma of the mandible. On the basis
of the clinical appearance, radiographic findings, and biopsy specimen, the
lesion was diagnosed as a myxofibroma. Segmental mandibular resection and
immediate reconstruction by vascularized fibular graft were performed. At the 18
month follow-up there was no evidence of recurrence of the tumor, and good
functional and aesthetic results were maintained.
PMID- 10783105
TI - Trapezoid bone fracture.
AB - Fractures of the carpal bones involve only a single bone or complex bones with or
without ligament rupture. However, fractures of the trapezoid are rarely seen.
Because the trapezoid is fastened to the trapezium, capitate, and scaphoid by
strong ligaments, fracture or dislocation is limited by this rigid fixation. The
authors present a single bone fracture of the trapezoid in a 40-year-old man. A
tomogram of the carpal bone was useful in diagnosing the trapezoid fracture. The
mechanism for development of fracture of the trapezoid alone is unknown. However,
fracture of the trapezoid seemed to occur when the wrist joint was forced with
excessive flexion stress that was placed on the trapezoid through the second
metacarpal bone indirectly. This occurred in the same manner that a walnut is
broken with nutcrackers.
PMID- 10783106
TI - Granular cell tumor in a child's finger.
AB - Granular cell tumor is an uncommon tumor found in the hand. It is probably of
Schwann cell origin and may be associated with a peripheral nerve. Although it is
often described as a painless tumor of the oral cavity and skin, its presentation
in the fingers or hand is often painful--a characteristic not well recognized.
PMID- 10783107
TI - Reconstruction of aplasia cutis congenita of the trunk in a newborn infant using
acellular allogenic dermal graft and cultured epithelial autografts.
AB - Aplasia cutis congenita, a congenital condition characterized by the absence of
all skin layers, occurs mostly on the scalp, but may also involve the trunk and
extremities. Conservative treatment using silver sulfadiazine with daily dressing
change has been recommended to avoid donor site morbidity and operative risks to
the neonate who may have other congenital defects. Others have proposed early
surgical intervention to prevent problems associated with delayed wound healing.
In this case of a newborn, the authors used an alternative therapy to avoid
delayed wound healing and multiple surgical interventions. During one operative
procedure, a 130-cm2 lesion on the trunk was covered with allogeneic dermis and
cultured epithelial autografts (CEAs). After 2.5 weeks and with three additional
applications of CEAs at bedside, 90% of the wound had healed. At 27 months, the
grafted area was smooth, and pliable with normal skin texture.
PMID- 10783108
TI - Technical refinements in the surgical treatment of gynecomastia.
AB - The authors present their experience with liposuction of breast fat followed by
sharp excision of the breast gland, when needed. Liposuction is performed,
introducing a short uterine curette through a hemicircular periareolar incision.
The suction is carried out as close as possible to the glandular tissue and all
around the areola in a fan shape until the boundaries of the mammary region are
reached in all directions to allow better skin redraping. Because the fat layers
are encased in the fibrous septi of the superficial fascial system, suction of
the fat lobules allows shrinkage of the septi and also enables skin retraction in
patients with marked gynecomastia and considerable skin redundancy. Moreover,
because liposuction causes an increase of coagulative factors in the treated
area, it plays an important role in spontaneous hemostasis. In fact, the
hypercoagulative state of the fat treated by liposuction implies minimal bleeding
in additional surgery. The removal of the residual mammary gland is very easy,
hemostasis is usually not needed, and drains are usually not used.
PMID- 10783109
TI - Reel people.
PMID- 10783110
TI - Re: Skin-sparing mastectomy with sun flap closure.
PMID- 10783111
TI - Re: Earlobe epidermal inclusion cyst excision using a Desmarres clamp.
PMID- 10783112
TI - Bilateral well-leg compartment syndrome after supine position surgery.
PMID- 10783113
TI - Flap model with a scar-induced invariable necrotic pattern.
PMID- 10783114
TI - Preoperative patient education: a study in reduction mammaplasty.
PMID- 10783115
TI - Recurrent, discharging congenital frontotemporal dermoid cyst.
PMID- 10783116
TI - Simple vacuum drainage of hematoma or seroma.
PMID- 10783117
TI - The effects of protease inhibitor therapy on human immunodeficiency virus type 1
levels in semen (AIDS clinical trials group protocol 850).
AB - Antiretroviral therapy may lead to decreased shedding of human immunodeficiency
virus type 1 (HIV-1) in genital secretions. Thirty men, 19 receiving amprenavir
and 11 receiving amprenavir, zidovudine, and lamivudine, donated blood and semen
while undergoing treatment, to evaluate the effects of these medications on HIV-1
shedding in semen. Before therapy, 4 men had HIV-1 RNA levels in seminal plasma
>6.0 log10 (1 million) copies/mL, markedly higher than levels in blood plasma.
Most men (77%) had HIV-1 RNA levels in seminal plasma below the limit of
quantification during therapy. Amprenavir alone suppressed HIV-1 RNA levels to
<400 copies/mL in seminal plasma in the majority of patients, the first direct
demonstration of the antiretroviral effects of a protease inhibitor in the male
genital tract. However, 8 men (27%) had measurable HIV-1 in seminal plasma at
their last study visit, 4 with increasing levels. Persistent replication of HIV
in the genital tract may have implications for the selection of resistant virus
and sexual transmission of HIV-1.
PMID- 10783118
TI - Absence of antibody against human papillomavirus type 16 E6 and E7 in patients
with cervical cancer is independent of sequence variations.
AB - It is not known whether the lack of antibody response against human
papillomavirus (HPV) type 16 E6 and E7 among some cervical cancer patients is due
to naturally existing sequence variations. In this study, naturally occurring HPV
16 E6 and E7 variants (including the prototype) were cloned, antigens were
expressed by in vitro transcription and translation, and the humoral immune
response of 34 HPV-16-positive cervical cancer patients was analyzed by
radioimmunoprecipitation assay (RIPA). In addition, the RIPA results were
compared with those of a sandwich-protein ELISA, to further substantiate antibody
status. Sera lacking E6 reactivity by RIPA remained negative by protein ELISA.
All E6 antigens (the prototype and the variants 350G?L83V, 131G?R10G/350G?L83V,
335T?H78Y/350G?L83V, 345G?Y81C/350G?L83V, and African 2 ?Af2) showed cross
reactivity by RIPA. The lack of HPV-16 E6 or E7 antibodies is independent of
naturally occurring variants in cervical cancer patients. Thus, testing for HPV
16 E6 or E7 prototype antigens seems to be sufficient in serological assays.
PMID- 10783120
TI - Mechanisms of cell injury and death in hyperoxia: role of cytokines and Bcl-2
family proteins.
PMID- 10783119
TI - Cationic proteins and bronchial hyperresponsiveness.
PMID- 10783121
TI - Pulmonary fibrosis: pathways are slowly coming into light.
PMID- 10783122
TI - Tumor antigens in thoracic malignancy.
PMID- 10783123
TI - Suppression of maxi-K channel and membrane depolarization by synthetic
polycations in single tracheal myocytes.
AB - Polycationic proteins, e.g., major basic protein from eosinophils or cathepsin G
from neutrophils, have been shown to increase nonspecific airway responsiveness.
Along with several indirect manners of action, polycations were reported to
contract smooth-muscle strips and to raise the cellular Ca(2+) concentration as a
direct action on airway smooth muscle. However, the mechanistic basis for the
direct behavior remains to be elucidated. To address this issue, we examined the
effects of synthetic cationic polypeptides poly-L-arginine and poly-L-lysine on
fresh single smooth-muscle cells from bovine trachea using a patch-clamp
technique. Both of the polycations significantly depolarized the membrane from a
baseline of about -40 to -20 mV in a dose-dependent manner. The polycations also
suppressed whole-cell spontaneous transient outward currents as well as both the
conductance (from a baseline of about 130 to 70 pS) and open-state probability
(about 25% of control values) of large-conductance Ca(2+)-dependent K(+) channel
(maxi-K channel) on excised outside-out patch membranes. The polycations were
without effect on the whole-cell Ca(2+) currents induced by depolarizing voltage
pulses. We concluded that the synthetic polycations had at least two sites of
action; one is the delayed rectifier K(+) channel that is responsible for the
membrane depolarization that increases Ca(2+) influx, and the other is the maxi-K
channel the suppression of which inhibits muscle relaxation. These results may
explain the direct contractile action and, therefore, one of the mechanisms
underlying the airway hyperresponsiveness induced by various polycationic
proteins.
PMID- 10783124
TI - Interleukin-6-induced protection in hyperoxic acute lung injury.
AB - Hyperoxic lung injury is commonly encountered in patients who require treatment
with high concentrations of inspired oxygen. To determine whether interleukin
(IL)-6 is protective in oxygen toxicity, we compared the effects of 100% O(2) in
transgenic mice that overexpress IL-6 in the lung and transgene (-) controls. IL
6 markedly enhanced survival, with 100% of transgene (-) animals dying within 72
to 96 h, 100% of transgene (+) animals living for more than 8 d and more than 90%
of transgene (+) animals living longer than 12 d. This protection was associated
with markedly diminished alveolar-capillary protein leak, endothelial and
epithelial membrane injury, and lung lipid peroxidation. Hyperoxia also caused
cell death with DNA fragmentation in the lungs of transgene (-) animals and IL-6
markedly diminished this cytopathic response. The protective effects of IL-6 were
not associated with significant alterations in the activities of copper/ zinc
superoxide dismutase (SOD) or manganese SOD. They were, however, associated with
the enhanced accumulation of the cell-death inhibitor Bcl-2, but not the cell
death stimulator BAX, and with the heightened accumulation of the cell-death
regulator tissue inhibitor of metalloproteinase-1 (TIMP-1). These studies
demonstrate that IL-6 markedly diminishes hyperoxic lung injury and that this
protection is associated with a marked diminution in hyperoxia-induced cell death
and DNA fragmentation. They also demonstrate that this protection is not
associated with significant alterations in SOD activity, but is associated with
the induction of Bcl-2 and TIMP-1.
PMID- 10783125
TI - Bleomycin-mediated pulmonary toxicity: evidence for a p53-mediated response.
AB - Bleomycin damages DNA and causes lung injury and fibrosis. To determine whether
bleomycin is associated with the appearance of DNA damage-inducible proteins, C3H
mice received either 0.4 mg bleomycin or normal saline intratracheally and were
killed 1 to 14 d later. The lungs were examined for expression of p53,
p21(WAF1/PiCl), and proliferating cell nuclear antigen (PCNA) using
immunohistochemistry and Western blotting. p53-positive cells first appeared at 5
d after treatment and peaked at 7 d; PCNA-positive cells appeared at 1 d after
treatment and peaked at 7 d; and p21-positive cells appeared at 5 d and peaked at
9 d. Western blot analysis confirmed that bleomycin upregulated the DNA damage
inducible proteins in a similar fashion. This is the first evidence that
bleomycin causes a p53-dependent response associated with acute injury in the
lung.
PMID- 10783126
TI - Serologic responses in patients with malignant mesothelioma: evidence for both
public and private specificities.
AB - Malignant mesothelioma (MM) is a pulmonary malignancy that appears to be
immunogenic based on a large number of studies in both animals and humans. This
notion is supported by our recent demonstration using Western blot analysis of
immunoglobulin G antibodies reactive with a variety of autoantigens in many
patients with MM. In view of the enormous potential of such antigens in early
diagnosis, immunotherapy, and vaccination of at-risk individuals, it was
essential to identify these antigens. We therefore applied the SEREX technique
(serologic identification by recombinant expression cloning), using a serum pool
from six patients as the probe against an expressed complementary DNA library
derived from a cloned MM cell line. We screened over one million recombinants and
obtained sequence information on eight antigens that had provoked immunoglobulin
heavy chain class switching, presumably as a consequence of T-cell recognition.
Six of these antigens were identifiable (U2AF[65], Siah binding protein,
topoisomerase IIbeta, ZFM1, mIre1, and pendulin), and of the others, one was
found as a single EST from a myotube library (Jemm-1); the other (Jemm-2) was not
represented in any EST database even as a weak homolog. Consistent with our
previous findings, each of the characterizable antigens would be expected to be
associated with the cell nucleus. Each of the autoantibody specificities was
uniquely associated with a single patient with the exception of antibodies to
TOPIIbeta and U2AF(65). We found 13 of 14 (93%) patients with MM had antibodies
to TOPIIbeta and two of 14 (14%) patients had antibodies to U2AF(65). The number
of serum reactivities, taken as a measure of the complexity of the immune
response, correlates with patient survival and with an index of systemic
inflammation. These data suggest that a broader range of serologic reactivities
reflects a more active host response to the presence of tumor.
PMID- 10783128
TI - A novel function of thyrotropin as a potentiator of electrolyte secretion from
the tracheal gland.
AB - Accumulating evidence suggests that thyrotropin (thyroid-stimulating hormone
[TSH]) plays some roles in immunoregulation by an extrathyroidal action. Because
airway submucosal glands are responsible for nonspecific and specific airway
defense, we tested the effect of TSH on feline tracheal submucosal gland using a
whole-cell patch-clamp technique, immunohistochemistry, and reverse
transcription/polymerase chain reaction (RT-PCR). TSH potentiated
neurotransmitter-induced ionic currents significantly in a dose-dependent manner.
Acetylcholine (10(-)(8) M)- and norepinephrine (10(-)(7) M)-induced inward
current (I(i)), which we previously showed to be a Cl(-) current, were increased
to about 3-fold the pre-TSH control responses, respectively, by 2.0 ng/ml TSH;
and to 6- and 23-fold the control values by 20.0 ng/ml TSH, respectively. TSH
alone was without effect up to 20.0 ng/ml. Follicular stimulating hormone only
slightly affected the I(i) (1. 5-fold the control). Analyses with
immunohistochemistry and RT-PCR failed to identify TSH receptors on the glandular
tissue. Maneuvers to raise the cellular adenosine 3',5'-cyclic monophosphate also
failed to mimic the TSH-mediated potentiation. The TSH effect appeared to be
mediated by a signaling pathway involving tyrosine kinase because its inhibitors
(genistein and herbimycin A) abolished the augmentation completely, and
interferon-gamma, a tyrosine kinase activator, imitated the TSH action on
submucosal gland. Thus, TSH may be an important regulator of airway fluid
secretion.
PMID- 10783127
TI - Matrix-associated transforming growth factor-beta1 primes mouse bone marrow
derived mast cells for increased high-affinity Fc receptor for immunoglobulin E
dependent eicosanoid biosynthesis.
AB - Mast cells at different tissue locations are heterogeneous with respect to
histochemical staining characteristics, granule protease and proteoglycan
content, and eicosanoid biosynthesis. We used Matrigel, an extract from the
Engelbreth-Holm-Swarm mouse sarcoma that is enriched in basement-membrane
proteins, to investigate the effect of tissue matrix proteins on the
differentiation of mouse mast cells, with particular attention to eicosanoid
biosynthesis. Culture of mouse bone-marrow cells in interleukin-3 on Matrigel for
3 to 4 wk provided a population of mast cells with more intense metachromasia and
increased safranin counterstaining compared with mast cells derived in the
absence of Matrigel (bone marrow-derived mast cells [BMMC]). High-affinity Fc
receptor for immunoglobulin E-dependent biosynthesis of prostaglandin D(2) and
leukotriene (LT) C(4) was 6- and 11-fold higher, respectively, from mast cells
derived in the presence of Matrigel compared with conventional BMMC derived in
its absence. BMMC derived in the presence of Matrigel also generated substantial
quantities of 6-trans-LTB(4) diastereoisomers and LTB(4), which were minimally
generated by conventional BMMC. When conventional BMMC derived in the absence of
Matrigel were then cultured on Matrigel for 5 d, eicosanoid biosynthesis was
upregulated without any change in granule staining characteristics. This
upregulation in eicosanoid biosynthesis was inhibited by neutralizing anti-
transforming growth factor (TGF)-beta1-specific antibodies, was reproduced by 1
ng/ml TGF-beta1, and was attributed to increased expression of cytosolic
phospholipase A(2).
PMID- 10783129
TI - Genetic linkage analysis of susceptibility to particle exposure in mice.
AB - Particle-induced increases in respiratory morbidity and mortality have been
observed worldwide in industrialized cities but the toxicologic mechanisms have
not been elucidated. It is hypothesized that subpopulations including the elderly
and individuals with cardiopulmonary disease are particularly at risk to the
effects of exposure. Genetic background is another important host factor that may
contribute to interindividual responsivity to particulate exposure. This study
was designed to identify susceptibility loci for alveolar macrophage (AM) immune
dysfunction induced by inhalation of sulfate-associated carbon particles in
susceptible C57BL/6J and resistant C3H/ HeJ inbred mice. AMs were chosen for
study because they represent an important component of host defense, and
compromised host defense has been hypothesized to be an important factor in
particle-induced respiratory morbidity. The quantitative phenotype for these
studies was Fc receptor-mediated phagocytic function, an index of AM integrity.
Analyses of macrophage dysfunction phenotypes of segregant and nonsegregant
populations derived from these two strains indicate that two unlinked genes
control susceptibility. A genome-wide linkage analysis of an intercross (F(2))
cohort identified significant and suggestive quantitative trait loci (QTLs) on
chromosomes 17 and 11, respectively. Candidate susceptibility genes were
identified for mice and humans by comparative mapping. Importantly, both QTLs
overlap previously identified QTLs for susceptibility to another common
pollutant, ozone. This is the first demonstration that genetic background is an
important determinant of responsiveness to particle-induced immune dysfunction,
and it has important implications for understanding the epidemiologic
associations between particulates and morbidity and mortality.
PMID- 10783130
TI - Molecular regulation of granulocyte macrophage colony-stimulating factor in human
lung epithelial cells by interleukin (IL)-1beta, IL-4, and IL-13 involves both
transcriptional and post-transcriptional mechanisms.
AB - Interleukin (IL)-1beta stimulates the release of granulocyte macrophage colony
stimulating factor (GM-CSF) from lung epithelial cells. To investigate the
molecular mechanisms underlying GM-CSF regulation, we studied GM-CSF production,
messenger RNA (mRNA) expression levels, and GM-CSF promoter activity in A549
human alveolar carcinoma cells stimulated with IL-1beta. Coincubation with IL-4
or IL-13 dose-dependently inhibited IL-1beta-induced GM-CSF release. Time-course
studies of intracellular and extracellular protein release and mRNA expression
indicated tight coupling of protein and mRNA synthesis within 6 h after
stimulation. IL-4 and IL-13 both inhibited expression of GM-CSF mRNA and protein
by 2 h after stimulation. Stable transfection of A549 cells, with GM-CSF
promoter/ enhancer constructs containing up to 3.3 kb upstream of the
transcription start site, revealed maximal activation by IL-1beta and phorbol 12
myristate 13-acetate (PMA) with a reporter containing the proximal promoter (-627
to +35). This excludes sequences further upstream from a major regulatory role in
GM-CSF promoter activation by IL-1beta or PMA in these cells. IL-4 and IL-13
downregulated promoter activation but had no effect on GM-CSF mRNA half-life.
However, IL-1beta activation of all constructs was far less pronounced than in
Jurkat T cells, suggesting a requirement for additional mechanisms, possibly post
transcriptional, to potentiate the observed transcriptional induction.
PMID- 10783131
TI - Mechanism of extracellular signal-regulated kinase (ERK)-1 and ERK-2 activation
by vanadium pentoxide in rat pulmonary myofibroblasts.
AB - Vanadium pentoxide (V(2)O(5)) is a cause of occupational asthma and chronic
bronchitis, yet the molecular mechanisms through which V(2)O(5) exerts its
effects on cell function are unclear. In this study we investigated the potential
of V(2)O(5) to activate the extracellular signal-regulated kinases 1 and 2 (ERK
1/2) in rat pulmonary myofibroblasts. Treatment of myofibroblasts with V(2)O(5)
resulted in the activation of ERK-1/2, yet the inert metal titanium dioxide had
no effect on ERK-1/2 activation. V(2)O(5)-induced ERK-1/2 activation was
abolished by pretreatment with forskolin or PD98059, indicating a dependence on
Raf and mitogen-activated protein (MAP) kinase kinase, respectively. Depletion of
conventional protein kinase C activity with phorbol 12-myristate 13-acetate did
not inhibit V(2)O(5)-induced ERK-1/2 activation. ERK-1/2 activation by V(2)O(5)
was inhibited > 70% with the epidermal growth factor receptor (EGF-R) tyrosine
kinase inhibitor AG1478. Phosphorylation of the 170-kD EGF-R by V(2)O(5) was
detected after immunoprecipitation with an anti-EGF-R antibody followed by
phosphotyrosine Western blotting. V(2)O(5) strongly tyrosine-phosphorylated a 115
kD protein (p115) and activation of p115 was inhibited 60 to 70% by AG1478,
indicating that this protein was an EGF-R substrate. Phosphorylation of p115 was
also observed in EGF-stimulated cells. Immunoprecipitation of V(2)O(5)- or EGF
treated cell lysates with an antibody against Src homology 2 protein tyrosine
phosphatase (SH-PTP2) identified p115 as a SH-PTP2-binding protein. Pretreatment
of cells with the antioxidant N-acetyl-L-cysteine blocked V(2)O(5)-induced MAP
kinase activation and p115 phosphorylation > 90%. These data suggest that
V(2)O(5) activation of ERK-1/2 is oxidant-dependent and mediated through tyrosine
phosphorylation of EGF-R and an EGF-R substrate which we identified as a 115-kD
SH-PTP2-binding protein.
PMID- 10783132
TI - Induction of cell cornification and enhanced squamous-cell marker SPRR1 gene
expression by phorbol ester are regulated by different signaling pathways in
human conducting airway epithelial cells.
AB - Phorbol ester is a strong inducer for both cell cornification and squamous-cell
marker SPRR1 gene expression in conducting airway epithelial cells. However, the
signaling pathways involved in the regulation of both events have not been
completely elucidated. The current study focuses on the common and divergent
pathways involved in the induction of these two activities by phorbol-13
myristate-12-acetate (PMA). Using a protein kinase (PK) C inhibitor,
bisindolylmaleimide I, PMA-induced cell cornification and SPRR1 gene expression
were abolished. Further, a PKC activator, indolactam V, induced cell
cornification in the absence of PMA treatment. These results suggest a PKC
dependent signaling pathway for both gene induction and enhanced cell
cornification by PMA. However, a mitogen-activated protein kinase-specific
inhibitor, PD98059, could only block the gene induction event but failed to
prevent cell cornification induced by PMA. These results suggest that diverse
signaling pathways after PKC activation by PMA are involved in the regulation of
these two events.
PMID- 10783133
TI - Modification of the inflammatory response to allergen challenge after exposure to
bacterial lipopolysaccharide.
AB - The potential role of respiratory infections in altering the development of atopy
and asthma is complex. Infections have been suggested to be effective in
preventing the induction of T-helper 2-polarized allergen-specific immunity in
early life, but also to exacerbate asthma in older, sensitized individuals. The
mechanism(s) underlying these effects are poorly defined. The aim of this work
was to determine the influence of lipopolysaccharide (LPS) exposure on the
development of sensitization to allergen and the response to allergen challenge
in vivo. Piebald-Virol-Glaxo rats were exposed to a single aerosol of LPS 1 d
before or 1, 2, 4, 6, 8, or 10 d after sensitization with ovalbumin (OVA). On Day
11 animals were exposed to 1% OVA and responses to allergen were measured 24 h
later, monitoring inflammatory cell influx and microvascular leakage into
bronchoalveolar lavage (BAL) fluid as well as pulmonary responses to methacholine
using the forced oscillation technique. Histologic analysis was included to
complement the BAL results. Single aerosol exposure to LPS 1 d before and up to 4
d after intraperitoneal injection of OVA protected against the development of OVA
specific immunoglobulin (Ig) E. LPS exposure 6, 8, or 10 d after sensitization
further exacerbated the OVA-induced cellular influx, resulting in neutrophilia
and increased Evans Blue dye leakage with no effect on serum IgE levels. In
addition, LPS abolished the OVA-induced hyperresponsiveness in sensitized animals
when given 18 h after OVA challenge. This study demonstrates that exposure to LPS
can modify the development of allergic inflammation in vivo by two independent
mechanisms. Exposure early in the sensitization process, up to Day 6 after
exposure to allergen, prevented allergen sensitization. Exposure to LPS after
allergen challenge in sensitized animals abolished the hyperresponsiveness and
modified the inflammatory cell influx characteristic of late-phase response to
allergen.
PMID- 10783134
TI - Adenoviral gene transfer is inhibited by soluble factors in malignant pleural
effusions.
AB - Direct in vivo gene delivery is a prerequisite for many gene therapy strategies;
however, efficacy has been limited by a lack of therapeutic gene transfer. In
studying intrapleural malignancy as a model for the gene therapy of non-small
cell lung cancer, we previously identified soluble chondroitin sulfate
proteoglycans/glycosaminoglycans (CS-PG/GAGs) in malignant pleural effusions
(MPE) as factors that inhibit retroviral vector (RV) transduction. Similarly, we
have observed inhibition to gene transfer in the fluid component of MPE using
adenoviral (Ad) vectors. Analyses indicate that the factors responsible for the
block are filterable, soluble, titrable, and heat stable (56 degrees C). Passage
through microporous membranes fractionates the inhibitory factors into large (>
100 kD) components of the effusions. In contrast to RV transduction, hyaluronic
acid or CS-PG/GAGs are not the inhibitors because the block is not reversed by
pretreatment of the effusions with mammalian hyaluronidase, and exogenous
addition of GAGs into the transduction media does not diminish Ad transduction.
In considering the mechanism of action of the inhibitory factors, we observe that
Ad entry, and specifically the binding of radiolabeled Ad to its target cell, is
inhibited in the presence of MPE. Ad internalization may also be impaired;
however, these studies exclude soluble fibronectin in MPE as a competitive
inhibitor of Ad transduction. Lastly, sepharose A- mediated immunoglobulin
depletion of MPE only partially reverses the block, and significant inhibition to
Ad gene transfer persists at lower adenovirus:target cell ratios. Identifying the
structural and functional basis for inhibition to Ad gene transfer may yield
specific strategies to enable better in vivo translation of gene therapy
approaches.
PMID- 10783135
TI - Genetic susceptibility to ozone-induced lung hyperpermeability: role of toll-like
receptor 4.
AB - The pollutant ozone (O(3)) induces lung hyperpermeability and inflammation in
humans and animal models. Among inbred strains of mice, there is a 3-fold
difference in total protein (a marker of permeability) recovered in
bronchoalveolar lavage (BAL) fluid after a 72-h exposure to 0.3 ppm O(3). To
determine the chromosomal locations of susceptibility genes, we performed a
genome screen using recombinant inbred (RI) strains of mice derived from O(3)
susceptible C57BL/6J (B6) and O(3)-resistant C3H/HeJ (HeJ) progenitors. Each RI
strain was phenotyped for O(3)-induced hyperpermeability, and linkage was
assessed for 558 markers using Map Manager QTb27. A significant quantitative
trait locus (QTL) was identified on chromosome 4. The likelihood ratio chi(2)
statistic (16.6) for the peak of the QTL was greater than the significance
threshold (16.3) determined empirically by permutation test. This QTL contains a
candidate gene, Toll-like receptor 4 (Tlr4 ), that recently has been implicated
in innate immunity and endotoxin susceptibility. The amount of the total trait
variance explained by the QTL at Tlr4, the gene with the highest likelihood ratio
statistic in the QTL, was approximately 70%. To test the role of Tlr4 in O(3)
induced hyperpermeability, BAL protein responses to O(3) were compared in
C3H/HeOuJ (OuJ) and HeJ mice that differ only at a polymorphism in the coding
region of Tlr4. Significantly greater protein concentrations (430 +/- 35
microg/ml) were found in OuJ mice compared with HeJ mice (258 +/- 18 microg/ml)
after exposure to O(3). Furthermore, reverse transcriptase/polymerase chain
reaction analysis demonstrated differential expression of Tlr4 message levels
between HeJ and OuJ mice after O(3) exposure. Together, results indicate that a
QTL on mouse chromosome 4 explains a significant portion of the genetic variance
in O(3)-induced hyperpermeability, and support a role for Tlr4 as a strong
candidate susceptibility gene.
PMID- 10783137
TI - Drusen associated with aging and age-related macular degeneration contain
proteins common to extracellular deposits associated with atherosclerosis,
elastosis, amyloidosis, and dense deposit disease.
AB - Age-related macular degeneration (AMD), a blinding disorder that compromises
central vision, is characterized by the accumulation of extracellular deposits,
termed drusen, between the retinal pigmented epithelium and the choroid. Recent
studies in this laboratory revealed that vitronectin is a major component of
drusen. Because vitronectin is also a constituent of abnormal deposits associated
with a variety of diseases, drusen from human donor eyes were examined for
compositional similarities with other extracellular disease deposits. Thirty-four
antibodies to 29 different proteins or protein complexes were tested for
immunoreactivity with hard and soft drusen phenotypes. These analyses provide a
partial profile of the molecular composition of drusen. Serum amyloid P
component, apolipoprotein E, immunoglobulin light chains, Factor X, and
complement proteins (C5 and C5b-9 complex) were identified in all drusen
phenotypes. Transcripts encoding some of these molecules were also found to be
synthesized by the retina, retinal pigmented epithelium, and/or choroid. The
compositional similarity between drusen and other disease deposits may be
significant in view of the recently established correlation between AMD and
atherosclerosis. This study suggests that similar pathways may be involved in the
etiologies of AMD and other age-related diseases.
PMID- 10783136
TI - Different expression of TNF-alpha receptors and prostaglandin E(2 )Production in
normal and fibrotic lung fibroblasts: potential implications for the evolution of
the inflammatory process.
AB - Normal human lung fibroblasts downregulate the production of tumor necrosis
factor (TNF)-alpha by activated monocytes through the production of prostaglandin
E(2) (PGE(2)), contributing to the local control of the inflammatory process. In
this study, we provide evidence that fibroblasts derived from diseased tissue,
such as fibrotic lung fibroblasts, exhibit different functional features compared
with normal cells, with particular regard to their modulatory role. Indeed,
fibrotic fibroblasts (FF) spontaneously produced less PGE(2) (3,300 +/- 410
pg/ml) compared with normal fibroblasts (NF) (7,500 +/- 270 pg/ml) and, as a
consequence, they showed a reduced ability to downregulate the production of TNF
alpha by lipopolysaccharide (LPS)- activated monocytes. The percentage of
inhibition induced by normal cells on the production of TNF-alpha by LPS
activated monocytes was 61 +/- 5.9%, whereas the inhibitory effect exerted by
fibrotic cells was reduced to 32 +/- 4% (P < 0.01). We have also observed that
the ability of TNF-alpha to induce PGE(2) was impaired in FF and was related to a
reduced expression of cyclooxygenase 2. This was possibly due to the reduction of
the expression of TNF receptors (TNFRs) in fibrotic cell lines compared with
normal cell lines. Flow cytometry revealed that the mean fluorescence intensity
(MFI) of both isoforms of TNFR was significantly lower in FF compared with NF.
The MFI of TNFR1 was 3. 55 +/- 0.12 for NF and 1.78 +/- 0.35 for FF (P < 0.001).
The MFI of TNFR2 was 1.95 +/- 0.27 for NF and 0.99 +/- 0.16 for FF (P < 0.01).
The analysis of the effect of TNF-alpha on some functions associated with
collagen metabolism in NF and FF showed an increase of the expression of the
receptor for collagen type I (alpha(2)beta(1) integrin) in NF (42 +/- 10%) and an
even larger increase in FF (102 +/- 23%) (P < 0.05). Interestingly, unlike NF,
TNF-alpha failed to increase matrix metalloproteinase 1 levels in FF and did not
cause any growth inhibition in these cells. The reduced capability of fibrotic
cells to produce PGE(2) either spontaneously or after TNF-alpha treatment may
lead to an unrestrained release of TNF-alpha from activated monocytes and, as a
result of the reduced expression of TNFRs, to a different response of these cells
to TNF-alpha. These changes may be important in the evolution of the inflammatory
process, potentially contributing to its transformation into a chronic and self
perpetuating process.
PMID- 10783138
TI - Direct interaction of GD3 ganglioside with mitochondria generates reactive oxygen
species followed by mitochondrial permeability transition, cytochrome c release,
and caspase activation.
AB - Glycosphingolipids, including gangliosides, are emerging as signaling
intermediates of extracellular stimuli. Because mitochondria play a key role in
the orchestration of death signals, we assessed the interaction of GD3
ganglioside (GD3) with mitochondria and the subsequent cascade of events that
culminate in cell death. In vitro studies with isolated mitochondria from rat
liver demonstrate that GD3 elicited a burst of peroxide production within 15-30
min, which preceded the opening of the mitochondrial permeability transition,
followed by cytochrome c (cyt c) release. These effects were mimicked by
lactosylceramide and N-acetyl-sphingosine but not by sphinganine or sphingosine
and were prevented by cyclosporin A and butylated hydroxytoluene (BHT).
Reconstitution of mitochondria pre-exposed to GD3 with cytosol from rat liver in
a cell-free system resulted in the proteolytic processing of procaspase 3 and
subsequent caspase 3 activation. Intact hepatocytes or U937 cells selectively
depleted of glutathione in mitochondria by 3-hydroxyl-4-pentenoate (HP) with the
sparing of cytosol reduced glutathione (GSH) were sensitized to GD3, manifested
as an apoptotic death. Inhibition of caspase 3 prevented the apoptotic phenotype
of HP-treated cells caused by GD3 without affecting cell survival; in contrast,
BHT fully protected HP-treated cells to GD3 treatment. Treatment of cells with
tumor necrosis factor increased the level of GD3, whereas blockers of
mitochondrial respiration at complex I and II protected sensitized cells to GD3
treatment. Thus, the effect of GD3 as a lipid death effector is determined by its
interaction with mitochondria leading to oxidant-dependent caspase activation.
Mitochondrial glutathione plays a key role in controlling cell survival through
modulation of the oxidative stress induced by glycosphingolipids.
PMID- 10783139
TI - High-affinity LPS binding domain(s) in recombinant factor C of a horseshoe crab
neutralizes LPS-induced lethality.
AB - SSCrFCES is a biologically active, recombinant fragment of factor C, which is the
endotoxin-sensitive serine protease of the LAL coagulation cascade. The
approximately 38 kDa protein represents the LPS binding domain of factor C. A
novel secretory signal directs the secretion of SSCrFCES into the culture
supernatant of Drosophila cells, and hence it is readily purified. By
differential ultrafiltration followed by preparative isoelectric membrane
electrophoresis, SSCrFCES was purified as an isoelectrically homogeneous and
stable monomeric protein. The ability of SSCrFCES to bind lipid A was analyzed
using an ELISA-based assay as well as surface plasmon resonance. SSCrFCES
exhibits high positive cooperativity of binding to two or three lipid A
molecules, with a Hill's coefficient of 2.2. The 50% endotoxin-neutralizing
concentration of SSCrFCES against 200 EU of endotoxin is approximately 0.069
microM, suggesting that SSCrFCES is an effective inhibitor of LAL coagulation
cascade. Although partially attenuated by human serum, as little as 1 microM of
SSCrFCES inhibits the LPS-induced secretion of hTNF-alpha and hIL-8 by THP-1 and
human peripheral blood mononuclear cells with greater potency than polymyxin B.
SSCrFCES is noncytotoxic, with a clearance rate of 4.7 ml/min. The L.D.(90) of
SSCrFCES for LPS lethality is achieved at 2 microM. These results demonstrate the
endotoxin-neutralizing capability of SSCrFCES in vitro and in vivo and its
potential use for the treatment of endotoxin-induced septic shock.
PMID- 10783140
TI - Genetic heterogeneity of angiogenesis in mice.
AB - Many diseases, including cancer, are dependent on the growth of new blood
vessels, a process known as angiogenesis. Differences in an individual's ability
to grow new blood vessels may influence the rate of progression of these
diseases. Here we show that different strains of inbred mice have an
approximately 10-fold range of response to growth factor-stimulated angiogenesis
in the corneal micropocket assay. The in vitro migratory activity of endothelial
cells from aortic rings of selected strains correlated with the in vivo
responsiveness. Further, a differential sensitivity to angiogenesis inhibitors
was seen between strains, with one strain demonstrating resistance to both TNP
470 and thalidomide. These results suggest the presence of genetic factors that
control individual angiogenic potential.
PMID- 10783141
TI - Sustained mammary gland-directed, ponasterone A-inducible expression in
transgenic mice.
AB - The ability to regulate temporal- and spatial-specific expression of target genes
in transgenic mice will facilitate analysis of gene function and enable the
generation of murine models of human diseases. The genetic analysis of mammary
gland tumorigenesis requires the development of mammary gland-specific
transgenics, which are tightly regulated throughout the adult mammary epithelium.
Analysis of genes implicated in mammary gland tumorigenesis has been hampered by
mosaic transgene expression and the findings that homozygous deletion of several
candidate genes (cyclin D1, Stat5A, prolactin receptor) abrogates normal mammary
gland development. We describe the development of transgenic mouse lines in which
sustained transgene expression was inducibly regulated, both specifically and
homogeneously, in the adult mammary gland epithelium. Transgenes encoding
RXRalpha and a chimeric ecdysone receptor under control of a modified MMTV-LTR,
which targets mammary gland expression, were used. These transgenic 'receptor'
lines were crossed with transgenic 'enhancer' lines in which the ecdysone/RXR
binding site induced ligand-dependent expression of transgenic beta
galactosidase. Pharmacokinetic analysis of a highly bioactive ligand (ponasterone
A), identified through screening ecdysteroids from local plants, demonstrated
sustained release and transgene expression in vivo. This transgenic model with
both tightly regulated and homogeneous transgene expression, which was sustained
in vivo using ligands readily extracted from local flora, has broad practical
applicability for genetic analysis of mammary gland disease.
PMID- 10783142
TI - Endothelial K(+) channel lacks the Ca(2+) sensitivity-regulating beta subunit.
AB - Hyperpolarizing large-conductance, Ca(2+)-activated K(+) channels (BK) are
important modulators of vascular smooth muscle and endothelial cell function. In
vascular smooth muscle cells, BK are composed of pore-forming alpha subunits and
modulatory beta subunits. However, expression, composition, and function of BK
subunits in endothelium have not been studied so far. In patch-clamp experiments
we identified BK (283 pS) in intact endothelium of porcine aortic tissue slices.
The BK opener DHS-I (0.05-0.3 micromol/l), stimulating BK activity only in the
presence of beta subunits, had no effect on BK in endothelium whereas the alpha
subunit selective BK opener NS1619 (20 micromol/l) markedly increased channel
activity. Correspondingly, mRNA expression of the beta subunit was undetectable
in endothelium, whereas alpha subunit expression was demonstrated. To investigate
the functional role of beta subunits, we transfected the beta subunit into a
human endothelial cell line (EA.hy 926). beta subunit expression resulted in an
increased Ca(2+) sensitivity of BK activity: the potential of half-maximal
activation (V(1/2)) shifted from 73.4 mV to 49.6 mV at 1 micromol/l [Ca(2+)](i)
and an decrease of the EC(50) value for [Ca(2+)](i) by 1 microM at +60 mV was
observed. This study demonstrates that BK channels in endothelium are composed of
alpha subunits without association to beta subunits. The lack of the beta subunit
indicates a substantially different channel regulation in endothelial cells
compared to vascular smooth muscle cells.
PMID- 10783143
TI - Increased phosphoinositide 3-kinase activity induces a lymphoproliferative
disorder and contributes to tumor generation in vivo.
AB - Alterations in the cell division:cell death ratio induce multiple autoimmune and
transformation processes. Phosphoinositide 3-kinase (PI3K) controls cell division
and cell death in vitro, but its effect on the function of the cellular immune
system and on tumor formation in mammals is poorly characterized. Here we show
that transgenic mice expressing in T lymphocytes an active form of PI3K derived
from a thymic lymphoma, p65(PI3K), developed an infiltrating lymphoproliferative
disorder and autoimmune renal disease with an increased number of T lymphocytes
exhibiting a memory phenotype and reduced apoptosis. This pathology was
strikingly similar to that described in mice exhibiting heterozygous loss of the
tumor suppressor PTEN, a lipid and protein phosphatase. We show that
overexpression of PTEN selectively blocks p65(PI3K)-induced 3T3 fibroblast
transformation. Moreover, the early development of T cell lymphomas in p65(PI3K)
Tg p53(-/-) mice indicated that PI3K contributes to tumor development. These
observations demonstrate that constitutive activation of PI3K extends T cell
survival in vivo, affects T cell homeostasis, and contributes to tumor
generation, supporting a model in which selective increases in one type of PTEN
substrate, the PI3K-derived lipid products, induce tumorigenesis. PI3K thus
emerges as a potential target in autoimmune disease and cancer therapy.
PMID- 10783144
TI - Identification of a novel partner of RNA polymerase II subunit 11, Che-1, which
interacts with and affects the growth suppression function of Rb.
AB - hRPB11 is a core subunit of RNA polymerase II (pol II) specifically down
regulated on doxorubicin (dox) treatment. Levels of this protein profoundly
affect cell differentiation, cell proliferation, and tumorigenicity in vivo. Here
we describe Che-1, a novel human protein that interacts with hRPB11. Che-1
possesses a domain of high homology with Escherichia coli RNA polymerase final
sigma-factor 70 and SV40 large T antigen. In addition, we report that Che-1
interacts with the retinoblastoma susceptibility gene (Rb) by two distinct
domains. Functionally, we demonstrate that Che-1 represses the growth suppression
function of Rb, counteracting the inhibitory action of Rb on the trans-activation
function of E2F1. These results identify a novel protein that binds Rb and the
core of pol II, and suggest that Che-1 may be part of transcription regulatory
complex.
PMID- 10783145
TI - The prostate apoptosis response-4 protein participates in motor neuron
degeneration in amyotrophic lateral sclerosis.
AB - Prostate apoptosis response-4 (Par-4), a protein containing a leucine zipper
domain within a death domain, is up-regulated in prostate cancer cells and
hippocampal neurons induced to undergo apoptosis. Here, we report higher Par-4
levels in lumbar spinal cord samples from patients with amyotrophic lateral
sclerosis (ALS) than in lumbar spinal cord samples from neurologically normal
patients. We also compared the levels of Par-4 in lumbar spinal cord samples from
wild-type and transgenic mice expressing the human Cu/Zn-superoxide dismutase
gene with a familial ALS mutation. Relative to control samples, higher Par-4
levels were observed in lumbar spinal cord samples prepared from the transgenic
mice at a time when they had hind-limb paralysis. Immunohistochemical analyses of
human and mouse lumbar spinal cord sections revealed that Par-4 is localized to
motor neurons in the ventral horn region. In culture studies, exposure of primary
mouse spinal cord motor neurons or NSC-19 motor neuron cells to oxidative insults
resulted in a rapid and large increase in Par-4 levels that preceded apoptosis.
Pretreatment of the motor neuron cells with a Par-4 antisense oligonucleotide
prevented oxidative stress-induced apoptosis and reversed oxidative stress
induced mitochondrial dysfunction that preceded apoptosis. Collectively, these
data suggest a role for Par-4 in models of motor neuron injury relevant to ALS.
PMID- 10783146
TI - Various effects of angiotensin II on amygdaloid neuronal activity in normotensive
control and hypertensive transgenic [TGR(mREN-2)27] rats.
AB - The effects of iontophoretically ejected angiotensin II (Ang II) on the firing
rate of neurons in the basolateral complex and the central and cortical amygdala
were investigated in two strains of urethane anesthetized rats. In normotensive
Sprague-Dawley rats, Ang II induced a significant increase in the discharge rate
of responsive amygdaloid neurons. In contrast, in the hypertensive transgenic
[TGR(mREN-2)27] rats with higher brain Ang II level, Ang II more often caused
inhibitory effects on the amygdaloid firing rate in comparison with controls. The
distribution of nonresponsive, excited, and inhibited neurons differed
significantly in the two rat strains. Moreover, the responsiveness of amygdaloid
neurons was significantly higher in transgenic rats in comparison with controls.
Both the increase and the decrease in the firing rate caused by Ang II could be
blocked either by angiotensin AT(1) or by AT(2) receptor-specific antagonists. In
many cases, the Ang II-induced decrease in the firing rate was antagonized by
bicuculline, a gamma-aminobutyric acid (GABA(A)) antagonist. The higher
responsiveness of amygdaloid neurons in transgenic rats as well as the
predominance of inhibitory effects, presumedly mediated by GABAergic
interneurons, could change the output of the amygdala and its influence on
thirst, kidney, and cardiovascular function or on processes of learning and
anxiety.
PMID- 10783148
TI - Elevated serum free fatty acid concentrations inhibit T lymphocyte signaling.
AB - Unbound cis-unsaturated free (i.e., nonesterified) fatty acids (FFA) inhibit T
lymphocyte activation in vitro and therefore may exert immunosuppressive effects.
However, in blood serum the major proportion of FFA is tightly bound to albumin,
whereas unbound FFA are hardly detectable. Since serum FFA elevation occurs under
pathological conditions like insulin resistance or cancer, which are often
associated with a disturbed immune response, we addressed the question of whether
increased serum FFA concentrations could affect T lymphocyte activation under in
vivo conditions. Our studies revealed that 1) addition of pure long-chain cis
unsaturated FFA in the absence of albumin inhibited calcium response in cultured
Jurkat T cells. 2) In healthy volunteers, serum FFA elevation by a lipid/heparin
infusion, including predominantly unsaturated fatty acids, decreased calcium
response of cultured T cells in contrast to studies without heparin. 3) Most
notably, stepwise increasing serum FFA by lipid/heparin infusion also inhibited
calcium response of simultaneously isolated autologous peripheral blood T
lymphocytes as well as their CD4(+) and CD8(+) subsets. In conclusion, our data
emphasize that serum FFA elevation is able to exert immunosuppressive effects in
vivo.
PMID- 10783147
TI - A protein kinase G-sensitive channel mediates flow-induced Ca(2+) entry into
vascular endothelial cells.
AB - The hemodynamic force generated by blood flow is considered to be the
physiologically most important stimulus for the release of nitric oxide (NO) and
prostacyclin (PGI(2)) from vascular endothelial cells (1). NO and PGI(2) then act
on the underlying smooth muscle cells, causing vasodilation and thus lowering
blood pressure (2, 3). One critical early event occurring in this flow-induced
regulation of vascular tone is that blood flow induces Ca(2+) entry into vascular
endothelial cells, which in turn leads to the formation of NO (4, 5). Here we
report a mechanosensitive Ca(2+)-permeable channel in vascular endothelial cells.
The activity of the channel was inhibited by 8-Br-cGMP, a membrane-permeant
activator of protein kinase G (PKG), in cell-attached membrane patches. The
inhibition could be reversed by PKG inhibitor KT5823 or H-8. A direct application
of active PKG in inside-out patches blocked the channel activity. Gd(3+), Ni(2+),
or SK&F-96365 also inhibited the channel activity. A study of fluorescent Ca(2+)
entry revealed a striking pharmacological similarity between the Ca(2+) entry
elicited by flow and the mechanosensitive Ca(2+)-permeable channel we identified,
suggesting that this channel is the primary pathway mediating flow-induced Ca(2+)
entry into vascular endothelial cells.
PMID- 10783149
TI - IL-4 regulates VIP receptor subtype 2 mRNA (VPAC2) expression in T cells in
murine schistosomiasis.
AB - In murine schistosomiasis, granuloma T cells express VPAC2 mRNA, whereas there is
none in splenocytes. This suggests that T cell VPAC2 mRNA is inducible. To
address this issue, splenocytes from schistosome-infected mice were incubated
with anti-CD3 to induce VPAC2 mRNA, which only appeared when cell cultures also
contained anti-IL-4 mAb. Granuloma cells expressed VPAC2 mRNA. This natural
expression decreased substantially when cells were cultured 3 days in vitro.
However, granuloma cells cultured with anti-IL-4 mAb strongly expressed VPAC2
mRNA. IL-4 KO mice were examined to further address the importance of IL-4 in
VPAC2 regulation. Splenocytes and dispersed granuloma cells from IL-4 KO animals
had substantially more VPAC2 mRNA than those in wild-type controls. VPAC2 mRNA
content decreased when cells were cultured with rIL-4. VPAC2 mRNA localized to
CD4+ T cells. Th1 cell lines expressed VPAC2 mRNA much stronger than Th2 cells.
Anti-IL-4 mAb increased VPAC2 mRNA expression in Th2 cells cultured in vitro.
However, rIL-4 could not suppress VPAC2 mRNA expression in Th1 cells. Thus, VPAC2
is an inducible CD4+ T cell receptor, and IL-4 down-modulates VPAC2 mRNA
expression in Th2 cells.
PMID- 10783151
TI - GFAT as a target molecule of methylmercury toxicity in Saccharomyces cerevisiae.
AB - Using a genomic library constructed from Saccharomyces cerevisiae, we have
identified a gene GFA1 that confers resistance to methylmercury toxicity. GFA1
encodes L-glutamine:D-fructose-6-phosphate amidotransferase (GFAT) and catalyzes
synthesis of glucosamine-6-phosphate. Transformed yeast cells expressing GFA1
demonstrated resistance to methylmercury but no resistance to p
chloromercuribenzoate, a GFAT inhibitor. The cytotoxicity of methylmercury was
inhibited by loading excess glucosamine 6-phosphate into yeast. Considering that
GFAT is an essential cellular enzyme, our findings suggest that GFAT is the major
target molecule of methylmercury in yeasts. This report is the first to identify
the target molecule of methylmercury toxicity in eukaryotic cells.
PMID- 10783150
TI - Oxidative DNA damage precedes DNA fragmentation after experimental stroke in rat
brain.
AB - Experimental stroke using a focal cerebral ischemia and reperfusion (FCIR) model
was induced in male Long-Evans rats by a bilateral occlusion of both common
carotid arteries and the right middle cerebral artery for 30-90 min, followed by
various periods of reperfusion. Oxidative DNA lesions in the ipsilateral cortex
were demonstrated using Escherichia coli formamidopyrimidine DNA N-glycosylase
(Fpg protein)-sensitive sites (FPGSS), as labeled in situ using digoxigenin-dUTP
and detected using antibodies against digoxigenin. Because Fpg protein removes 8
hydroxy-2'-deoxyguanine (oh8dG) and other lesions in DNA, FPGSS measure oxidative
DNA damage. The number of FPGSS-positive cells in the cortex from the sham
operated control group was 3 +/- 3 (mean +/- SD per mm(2)). In animals that
received 90 min occlusion and 15 min of reperfusion (FCIR 90/15), FPGSS-positive
cells were significantly increased by 200-fold. Oxidative DNA damage was
confirmed by using monoclonal antibodies against 8-hydroxy-guanosine (oh8G) and
oh8dG. A pretreatment of RNase A (100 microg/ml) to the tissue reduced, but did
not abolish, the oh8dG signal. The number of animals with positive FPGSS or oh8dG
was significantly (P<0.01) higher in the FCIR group than in the sham-operated
control group. We detected few FPGSS of oh8dG-positive cells in the animals
treated with FCIR of 90/60. No terminal UTP nicked-end labeling (TUNEL)-positive
cells, as a detection of cell death, were detected at this early reperfusion
time. Our data suggest that early oxidative DNA lesions elicited by experimental
stroke could be repaired. Therefore, the oxidative DNA lesions observed in the
nuclear and mitochondrial DNA of the brain are different from the DNA
fragmentation detected using TUNEL.
PMID- 10783152
TI - Discoidin domain receptor 1 (DDR1) signaling in PC12 cells: activation of
juxtamembrane domains in PDGFR/DDR/TrkA chimeric receptors.
AB - The discoidin domain receptor (DDR1) is characterized by a discoidin I motif in
the extracellular domain, an unusually long cytoplasmic juxtamembrane (JM)
region, and a kinase domain that is 45% identical to that of the NGF receptor,
TrkA. DDR1 also has a major splice form, which has a 37 amino acid insert in the
JM region with a consensus Shc PTB site that is lacking in the shorter receptor.
One class of ligands for the DDR receptors has recently been identified as being
derived from the collagen family, but neither native PC12 cells, which express
modest amounts of DDR1, nor transfected PC12 cells, which express much larger
amounts of DDR1, respond to this ligand. A chimeric receptor, containing the
extracellular domain of hPDGFRbeta fused to the transmembrane and intracellular
regions of DDR1, also fails to mediate neuronal-like differentiation in stably
transfected PC12 cells and is only weakly autophosphorylated. However, chimeric
receptors, which are composed of combinations of intracellular regions from DDR1
and TrkA (with the extracellular domain of hPDGFRbeta), in some cases provided
ligand (PDGF) -inducible receptor responses. Those with the TrkA kinase domain
and the DDR1 JM regions were able to produce differentiation to varying degrees,
whereas the opposite combination did not. Analysis of the signaling responses of
the two chimeras with DDR1 JM sequences (with and without the insert) indicated
that the shorter sequence bound and activated FRS2 whereas the insert-containing
form activated Shc instead. Both activated PLCgamma through the carboxyl-terminal
tyrosine of the TrkA domain (Y785 in TrkA residue numbering). Mutation of this
site (Y-->F) eliminated PLCgamma activation (indicating there are no other
cryptic binding sites for PLCgamma in the DDR1 sequences) and markedly reduced
the differentiative activity of the receptor. This is in contrast to TrkA (or
PDGFRbeta/TrkA chimeras), where ablation of this pathway has no notable effect on
PC12 cell morphogenic responses. Thus, the activation of FRS2 and Shc (leading to
MAPK activation) is weaker in the DDR1/TrkA chimeras than in TrkA alone, and the
PLCgamma contribution becomes essential for full response. Nonetheless, both DDR1
JM regions contain potentially usable signaling sites, albeit they apparently are
not activated directly in DDR1 (or DDR1 chimeras) in a ligand-dependent fashion.
These findings suggest that the DDR1 receptors do have signaling capacity but may
require additional components or altered conditions to fully activate their
kinase domains and/or sustain the activation of the JM sites.
PMID- 10783153
TI - Is creatine kinase responsible for fatigue? Studies of isolated skeletal muscle
deficient in creatine kinase.
AB - Creatine kinase (CK) is a key enzyme for maintaining a constant ATP/ADP ratio
during rapid energy turnover. To investigate the role of CK in skeletal muscle
fatigue, we used isolated whole muscles and intact single fibers from CK
deficient mice (CK(-/-)). With high-intensity electrical stimulation, single
fibers from CK(-/-) mice displayed a transient decrease in both tetanic free
myoplasmic [Ca(2+)] ([Ca(2+)](i), measured with the fluorescent dye indo-1) and
force that was not observed in wild-type fibers. With less intense, repeated
tetanic stimulation single fibers and EDL muscles, both of which are fast-twitch,
fatigued more slowly in CK(-/-) than in wild-type mice; on the other hand, the
slow-twitch soleus muscle fatigued more rapidly in CK(-/-) mice. In single wild
type fibers, tetanic force decreased and [Ca(2+)](i) increased during the first
10 fatiguing tetani, but this was not observed in CK(-/-) fibers. Fatigue was not
accompanied by phosphocreatine breakdown and accumulation of inorganic phosphate
in CK(-/-) muscles. In conclusion, CK is important for avoiding fatigue at the
onset of high-intensity stimulation. However, during more prolonged stimulation,
CK may contribute to the fatigue process by increasing the myoplasmic
concentration of inorganic phosphate.
PMID- 10783154
TI - Stretch-induced endothelin B receptor-mediated apoptosis in vascular smooth
muscle cells.
AB - Growing evidence suggests that a pressure-induced increase in the synthesis of
endothelin (ET-1) is involved in arterial remodeling and, as a consequence, in
the manifestation of chronic hypertension. To study potential stretch-induced
changes in gene expression and their functional consequences, we have cultured
rat aortic smooth muscle cells (raSMC) and porcine aortic endothelial cells
(PAEC) on flexible elastomer membranes. The cells were periodically stretched (up
to 20% elongation, 0.5 Hz, 6 h) and the expression of prepro-ET-1 and that of the
endothelin A and B receptors (ET(A)-R and ET(B)-R) were analyzed by semi
quantitative RT-PCR analysis and ELISA (ET-1). In contrast to PAEC where ET-1
synthesis was up-regulated up to eightfold on exposure to cyclic stretch, ET-1
synthesis in raSMC was decreased by more than 80% under these conditions. ET(A) R
-mRNA expression in stretched raSMC declined to 50% whereas ET(B) R -mRNA levels
were increased up to 10-fold. One functional consequence of this apparent shift
in receptor abundance was an apoptosis-promoting action of exogenous ET-1 (10
nM), as judged by the appearance of subdiploid peaks during FACS analysis,
caspase-3 activation and chromatin condensation. This ET-1-induced apoptosis
appeared to be ET(B)-R mediated, as it was completely suppressed by the ET(B)-R
antagonist BQ 788 but not by the ET(A)-R antagonist BQ 123. Moreover, raSMC
derived from homozygous spotting lethal rats, which lack a functional ET(B)-R,
showed no signs of apoptosis after exposure to cyclic strain and exogenous ET-1.
These findings suggest a central role for the endothelin system in the onset of
hypertension-induced remodeling in conduit arteries, which may proceed via an
initial stretch-induced apoptosis of the smooth muscle cells.
PMID- 10783155
TI - Intrinsic metabolic depression in cells isolated from the hepatopancreas of
estivating snails.
AB - Many animals across the phylogenetic scale are routinely capable of depressing
their metabolic rate to 5-15% of that at rest, remaining in this state sometimes
for years. However, despite its widespread occurrence, the biochemical processes
associated with metabolic depression remain obscure. We demonstrate here the
development of an isolated cell model for the study of metabolic depression. The
isolated cells from the hepatopancreas (digestive gland) of the land snail (Helix
aspersa) are oxygen conformers; i.e., their rate of respiration depends on pO(2).
Cells isolated from estivating snails show a stable metabolic depression to 30%
of control (despite the long and invasive process of cell isolation) when
metabolic rate at the physiological pH and pO(2) of the hemolymph of estivating
snails is compared with metabolic rate at the physiological pH and pO(2) of the
hemolymph of control snails. When the extrinsic effects of pH and pO(2) are
excluded, the intrinsic metabolic depression of the cells from estivating snails
is still to below 50% of control snails. The in vitro effect of pO(2) on
metabolic rate is independent of pH and state (awake or estivating), but the
effects of pH and state significantly interact. This suggests that pH and state
change affect metabolic depression by similar mechanisms but that the metabolic
depression by hypoxia involves a separate mechanism.
PMID- 10783156
TI - Covalent cross-linking of secreted bovine thyroglobulin by transglutaminase.
AB - Extracellular storage of thyroglobulin (TG) is a prerequisite for maintaining
constant levels of thyroid hormones in vertebrates. Storage of TG within the
follicle lumen is achieved by compactation and by the formation of covalent cross
links between TG molecules. In bovine thyroids, approximately 75% of the cross
links are other than disulfide bonds (J. Cell Biol. 180, 1071-1081). We have now
shown that polymeric TG contains a large number of N(epsilon)(gamma
glutamyl)lysine cross-links and that only traces of these can be found in the
soluble form of TG. Because such isopeptide bridges are generated usually by the
action of a transglutaminase, it is reasonable to propose that the covalent
polymerization of TG in the globules is under the control of this enzyme. Soluble
TG was shown to be a substrate for transglutaminase in vitro; moreover, the
presence of transglutaminase was demonstrated by immunofluorescence and by
immunoblotting in freshly isolated bovine thyroid globules. With immunoelectron
microscopy, transglutaminase was detected in the cytoplasm of thyrocytes, but not
in compartments of the secretory pathway. Only one messenger RNA for
transglutaminase was found by Northern blotting. Sequencing of the cloned gene
failed to reveal a secretory signal, which supports the notion that the thyroid
transglutaminase is the cytosolic type. Apparently, the enzyme reaches the lumen
of the follicle by an as yet unknown pathway to catalyze the covalent cross
linking of thyroid globules in this extracellular compartment.
PMID- 10783157
TI - Insulin regulates soluble amyloid precursor protein release via phosphatidyl
inositol 3 kinase-dependent pathway.
AB - Several lines of biochemical evidence correlate the presence of energy metabolic
defects with the functional alterations associated with brain aging and with the
pathogenesis of neurodegenerative disorders such as Alzheimer's disease. Within
this context we tested the ability of insulin to regulate the amyloid precursor
protein (APP) processing in SH-SY5Y neuroblastoma cells. Our findings show that
insulin promotes APP metabolism by a glucose-independent mechanism. We
demonstrate a novel intracellular pathway that increases the rate of secretion of
soluble APP through the activity of phosphatidyl-inositol 3 kinase (PI3-K). This
pathway, downstream of insulin receptor tyrosine kinase activity, does not
involve either the activation of protein kinase C or the mitogen-activated
protein kinase (MAP-K) pathway. Because of the physiological role of PI3-K in the
translocation of glucose transporter-containing vesicles, we speculate that PI3-K
involvement in APP metabolism may act at the level of vesicular trafficking.
PMID- 10783159
TI - ASBMB/ASPET 2000 june 4-8, 2000 boston, massachusetts
PMID- 10783158
TI - Suppression of neurocognitive damage in LP-BM5-infected mice with a targeted
deletion of the TNF-alpha gene.
AB - Brain levels of TNF-alpha increase in many inflammatory conditions, including HIV
1 infection, and may contribute to neurodegenerative processes. The paucity of
agents that can selectively and potently block TNF-alpha processing or its
receptors has led us to investigate the role of TNF-alpha in chronic
neurodegeneration associated with retroviral infection using mice with targeted
deletions of the TNF-alpha gene. Infection of wild-type C57BL/6 mice with the LP
BM5 murine leukemia retrovirus mixture leads to the development of a severe
immunodeficiency as well as cognitive deficits and neuronal damage. TNF-alpha-(-/
) mice infected with LP-BM5 developed a systemic immunopathology
indistinguishable in severity from that observed in contemporaneously infected
wild-type mice. In contrast, the performance of infected TNF-alpha-(-/-) mice in
the Y-maze and Morris water maze was not different from that of uninfected TNF
alpha-(-/-) mice. The extent of glial activation in the striatum, as indicated by
the increase in density of peripheral benzodiazepine receptors, was equivalent in
both groups of LP-BM5-infected mice. However, the decrease in striatal MAP-2
expression, a marker of neurodegeneration observed in infected wild-type mice,
was not found in infected TNF-alpha-(-/-) mice. While the loss of TNF-alpha
appeared to have no effect on the course or severity of the central or peripheral
immunopathology resulting from LP-BM5 infection, the behavioral and biochemical
manifestations were substantially curtailed in the TNF-alpha-(-/-) mice. These
findings directly support a role for TNF-alpha in the neurodegenerative processes
associated with viral infections such as HIV-1.
PMID- 10783160
TI - Side-branching in the mammary gland: the progesterone-Wnt connection.
PMID- 10783161
TI - The leucine-rich repeat protein SUR-8 enhances MAP kinase activation and forms a
complex with Ras and Raf.
AB - Caenorhabditis elegans sur-8 encodes a positive regulator of Ras signaling. We
investigated the mechanism by which the human Sur-8 homolog can positively
regulate Ras-MAP kinase signaling in mammalian cells. Sur-8 expression enhances
Ras- or EGF-induced Raf and ERK activation but has no effect on ERK activation
induced by active Raf or MEK. Furthermore, Sur-8 expression does not increase AKT
or JNK activation. Sur-8 interacts with Ras and Raf and is able to form a ternary
complex with the two proteins. Thus, Sur-8 may function as a scaffold that
enhances Ras-MAP kinase signal transduction by facilitating the interaction
between Ras and Raf.
PMID- 10783162
TI - Proteolysis in Caenorhabditis elegans sex determination: cleavage of TRA-2A by
TRA-3.
AB - The Caenorhabditis elegans tra-3 gene promotes female development in XX
hermaphrodites and encodes an atypical calpain regulatory protease lacking
calcium-binding EF hands. We report that despite the absence of EF hands, TRA-3
has calcium-dependent proteolytic activity and its proteolytic domain is
essential for in vivo function. We show that the membrane protein TRA-2A, which
promotes XX female development by repressing the masculinizing protein FEM-3, is
a TRA-3 substrate. Cleavage of TRA-2A by TRA-3 generates a peptide predicted to
have feminizing activity. These results indicate that proteolysis regulated by
calcium may control some aspects of sexual cell fate in C. elegans.
PMID- 10783163
TI - Ku complex interacts with and stimulates the Werner protein.
AB - Werner syndrome (WS) is the hallmark premature aging disorder in which affected
humans appear older than their chronological age. The protein WRNp, defective in
WS, has helicase function, DNA-dependent ATPase, and exonuclease activity.
Although WRNp functions in nucleic acid metabolism, there is little or no
information about the pathways or protein interactions in which it participates.
Here we identify Ku70 and Ku86 as proteins that interact with WRNp. Although Ku
proteins had no effect on ATPase or helicase activity, they strongly stimulated
specific exonuclease activity. These results suggest that WRNp and the Ku complex
participate in a common DNA metabolic pathway.
PMID- 10783164
TI - Mcm10 and the MCM2-7 complex interact to initiate DNA synthesis and to release
replication factors from origins.
AB - MCM2-7, a complex of six subunits, is an essential component of the
prereplication chromatin that is assembled at Saccharomyces cerevisiae
replication origins during G(1) phase. It is also believed to be the processive
helicase at growing forks. To elucidate the action of MCM2-7 during the
transition from initiation to elongation replication, we have focused our studies
on Mcm10, a replication initiation protein that physically interacts with members
of the MCM2-7 complex. We show that Mcm10 is a chromatin-associated protein that
mediates the association of the MCM2-7 complex with replication origins.
Furthermore, diminished interaction between Mcm10 and Mcm7, a subunit of the MCM2
7 complex, by a mutation in either Mcm10 or Mcm7 inhibits replication initiation.
Surprisingly, a double mutant containing both the mcm10-1 and mcm7-1 (cdc47-1)
alleles restores interaction between Mcm10 and Mcm7 and corrects all of the
defects exhibited by each of the single mutants, including the stalling of
replication forks at replication origins typically seen in mcm10-1 cells. This
mutual compensation of defects between two independently isolated mutations is
allele specific. These results suggest that Mcm10, like Mcm7, is a critical
component of the prereplication chromatin and that interaction between Mcm10 and
Mcm7 is required for proper replication initiation and prompt release of origin
bound factors.
PMID- 10783165
TI - BASC, a super complex of BRCA1-associated proteins involved in the recognition
and repair of aberrant DNA structures.
AB - We report the identities of the members of a group of proteins that associate
with BRCA1 to form a large complex that we have named BASC (BRCA1-associated
genome surveillance complex). This complex includes tumor suppressors and DNA
damage repair proteins MSH2, MSH6, MLH1, ATM, BLM, and the RAD50-MRE11-NBS1
protein complex. In addition, DNA replication factor C (RFC), a protein complex
that facilitates the loading of PCNA onto DNA, is also part of BASC. We find that
BRCA1, the BLM helicase, and the RAD50-MRE11-NBS1 complex colocalize to large
nuclear foci that contain PCNA when cells are treated with agents that interfere
with DNA synthesis. The association of BRCA1 with MSH2 and MSH6, which are
required for transcription-coupled repair, provides a possible explanation for
the role of BRCA1 in this pathway. Strikingly, all members of this complex have
roles in recognition of abnormal DNA structures or damaged DNA, suggesting that
BASC may serve as a sensor for DNA damage. Several of these proteins also have
roles in DNA replication-associated repair. Collectively, these results suggest
that BRCA1 may function as a coordinator of multiple activities required for
maintenance of genomic integrity during the process of DNA replication and point
to a central role for BRCA1 in DNA repair.
PMID- 10783166
TI - Nuclear localization and histone acetylation: a pathway for chromatin opening and
transcriptional activation of the human beta-globin locus.
AB - We have investigated the mechanism, structural correlates, and cis-acting
elements involved in chromatin opening and gene activation, using the human beta
globin locus as a model. Full transcriptional activity of the human beta-globin
locus requires the locus control region (LCR), composed of a series of nuclease
hypersensitive sites located upstream of this globin gene cluster. Our previous
analysis of naturally occurring and targeted LCR deletions revealed that
chromatin opening and transcriptional activity in the endogenous beta-globin
locus are dissociable and dependent on distinct cis-acting elements. We now
report that general histone H3/H4 acetylation and relocation of the locus away
from centromeric heterochromatin in the interphase nucleus are correlated and do
not require the LCR. In contrast, LCR-dependent promoter activation is associated
with localized histone H3 hyperacetylation at the LCR and the transcribed beta
globin-promoter and gene. On the basis of these results, we suggest a multistep
model for gene activation; localization away from centromeric heterochromatin is
required to achieve general hyperacetylation and an open chromatin structure of
the locus, whereas a mechanism involving LCR/promoter histone H3 hyperacetylation
is required for high-level transcription of the beta-globin genes.
PMID- 10783167
TI - Bromodomain factor 1 corresponds to a missing piece of yeast TFIID.
AB - The basal transcription factor TFIID consists of the TATA-binding protein (TBP)
and TBP-associated factors (TAFs). Yeast Taf67 is homologous to mammalian
TAF(II)55. Using a yeast two-hybrid screen to identify proteins that interact
with Taf67, we isolated Bromodomain factor 1 (Bdf1) and its homolog (Bdf2). The
Bdf proteins are genetically redundant, as cells are inviable without at least
one of the two BDF genes. Both proteins contain two bromodomains, a motif found
in several proteins involved in transcription and chromatin modification. The BDF
genes interact genetically with TAF67. Furthermore, Bdf1 associates with TFIID
and is recruited to a TATA-containing promoter. Deletion of Bdf1 or the Taf67 Bdf
interacting domain leads to defects in gene expression. Interestingly, the higher
eukaryotic TAF(II)250 has an acetyltransferase activity, two bromodomains, and an
associated kinase activity. Its yeast homolog, Taf145, has acetyltransferase
activity but lacks the bromodomains and kinase. Bdf1, like TAF(II)250, has a
kinase activity that maps carboxy-terminal to the bromodomains. The structural
and functional similarities suggest that Bdf1 corresponds to the carboxy-terminal
region of higher eukaryotic TAF(II)250 and that the interaction between TFIID and
Bdf1 is important for proper gene expression.
PMID- 10783168
TI - Leptin-specific patterns of gene expression in white adipose tissue.
AB - Leptin is a hormone that regulates body weight by decreasing food intake and
increasing energy expenditure. ob/ob mice carry leptin mutations and are obese
and hyperphagic. Leptin administration to lean and ob/ob mice activates a novel
metabolic program that depletes adipose tissue. Although this response is
physiologically distinct from that evident after food restriction, the molecular
nature of these differences is as yet unknown. Expression monitoring of 6500
genes using oligonucleotide microarrays in wild-type, ob/ob, and transgenic mice
expressing low levels of leptin revealed that differences in ambient leptin
levels have dramatic effects on the phenotype of white adipose tissue. These data
identified a large number of genes that are differentially expressed in ob/ob
mice. To delineate the components of the transcriptional program specifically
affected by leptin, the level of the same 6500 genes was monitored in wild-type
and ob/ob mice at various times after leptin treatment or food restriction. A
novel application of k-means clustering identified 8 clusters of adipose tissue
genes whose expression was different between leptin treatment and food
restriction in ob/ob mice and 10 such clusters in wild-type experiments. One of
the clusters was repressed specifically by leptin in both wild-type and ob/ob
mice and included several genes known to be regulated by SREBP-1/ADD1. Further
studies confirmed that leptin decreases the levels of SREBP-1/ADD1 RNA and
transcriptionally active SREBP-1/ADD1 protein in white adipose tissue. Future
studies of the molecular basis for the apparent coordinate regulation of the
other clusters of leptin-regulated genes may reveal additional mechanisms by
which leptin exerts its weight-reducing effects.
PMID- 10783169
TI - Analysis of p53-regulated gene expression patterns using oligonucleotide arrays.
AB - Oligonucleotide microarrays were employed to quantitate mRNA levels from a large
number of genes regulated by the p53 transcription factor. Responses to DNA
damage and to zinc-inducible p53 were compared for their transcription patterns
in cell culture. A cluster analysis of these data demonstrates that genes induced
by gamma radiation, UV radiation, and the zinc-induced p53 form distinct sets and
subsets with a few genes in common to all these treatments. Cell type- or cell
line-specific p53 responses were detected. When p53 proteins were induced with
zinc, the kinetics of induction or repression of mRNAs from p53-responsive genes
fell into eight distinct classes, five different kinetics of induction, and three
different kinetics of repression. In addition, low levels of p53 in a cell
induced or repressed only a subset of genes observed at higher p53 levels. The
results of this study demonstrate that the nature of the p53 response in diverse
mRNA species depends on the levels of p53 protein in a cell, the type of inducing
agent or event, and the cell type employed. Of 6000 genes examined for p53
regulatory responses, 107 induced and 54 repressed genes fell into categories of
apoptosis and growth arrest, cytoskeletal functions, growth factors and their
inhibitors, extracellular matrix, and adhesion genes.
PMID- 10783170
TI - Induction of medulloblastomas in p53-null mutant mice by somatic inactivation of
Rb in the external granular layer cells of the cerebellum.
AB - Medulloblastomas are among the most common malignancies in childhood, and they
are associated with substantial mortality and morbidity. The molecular
pathogenesis as well as the ontogeny of these neoplasms is still poorly
understood. We have generated a mouse model for medulloblastoma by Cre-LoxP
mediated inactivation of Rb and p53 tumor suppressor genes in the cerebellar
external granular layer (EGL) cells. GFAP-Cre-mediated recombination was found
both in astrocytes and in immature precursor cells of the EGL in the developing
cerebellum. GFAP-Cre;Rb(LoxP/LoxP);p53(-/- or LoxP/LoxP) mice developed highly
aggressive embryonal tumors of the cerebellum with typical features of
medulloblastoma. These tumors were identified as early as 7 weeks of age on the
outer surface of the molecular layer, corresponding to the location of the EGL
cells during development. Our results demonstrate that loss of function of RB is
essential for medulloblastoma development in the mouse and strongly support the
hypothesis that medulloblastomas arise from multipotent precursor cells located
in the EGL.
PMID- 10783172
TI - Fragmented responsibility, deteriorating care.
PMID- 10783171
TI - Inhibitor of striate conditionally suppresses cell proliferation in variegated
maize.
AB - Since the work done by R.A. Emerson in the 1930s, Inhibitor of striate (Isr) has
been recognized as a dose-dependent genetic modifier of variegation in chlorotic
leaf striping mutants of maize such as striate2 (sr2). We have shown that Isr
specifically inhibits proliferation and differentiation of plastid defective
cells in sr2 mutants. Leaf narrowing is due to loss of intermediate veins and
ground tissue located at leaf margins, and the few remaining plastid defective
cells are of irregular size and aberrant organization. The Isr gene has been
cloned by targeted transposon tagging. Isr mRNA is expressed throughout young
leaves, but Isr chimeras indicate that the expression of Isr at leaf margins is
sufficient to suppress both the lateral expansion of sr2 leaves and the extent of
striping. Isr protein appears to encode a chloroplast protein with sequence
similarity to a family of bacterial phosphatases involved in carbon catabolite
repression or in carbon metabolism. We propose that the action of Isr in nuclear
and plastid communication could be triggered by carbon stress.
PMID- 10783173
TI - Personal accounts: first-person accounts in the Journal's first quarter-century.
PMID- 10783174
TI - Datapoints: Estimates of children and adolescents with school-related behavioral
problems.
PMID- 10783176
TI - Best practices: Population density as a factor in the rehospitalization of
persons with serious and persistent mental illness.
PMID- 10783177
TI - Rehab rounds: Behavioral management of aggression through teaching interpersonal
skills.
PMID- 10783178
TI - Trends in community mental health programs.
PMID- 10783179
TI - Whatever happened to community mental health?
PMID- 10783180
TI - Utilization management in a large managed behavioral health organization.
AB - OBJECTIVE: The utilization management process of a managed behavioral health
organization was examined to determine the frequency and types of reviews and the
extent to which rationing of service was achieved through the denial of services.
METHODS: A case study of the utilization management program of a large managed
behavioral health organization was done. Information was gathered from claims for
1997, and utilization review data were drawn from 51 plans. Data were examined by
review type and authorization actions. RESULTS: The utilization management
program performed a total of 9, 639 reviews. The most common type was concurrent
review for additional outpatient therapy visits (46 percent). The second most
common type was concurrent facility review (12.9 percent). The vast majority of
authorizations were approved at the level requested by the provider (91.8
percent). Very few services were denied (.8 percent) or approved at a level lower
than requested by the provider (1.3 percent). CONCLUSIONS: Although concerns have
been raised about the high denial rates of utilization management programs, this
study found very low denial rates. Further studies are needed to determine the
precise mechanisms used in utilization management programs to control
utilization. In addition, the large number of reviews raises questions about the
time and opportunity costs of the review process.
PMID- 10783181
TI - A review of pharmacotherapy of major depression in children and adolescents.
AB - OBJECTIVE: The review examined the historical progression and current status of
pharmacotherapy of child and adolescent major affective disorder. METHODS: A
MEDLINE search was used to identify double-blind, placebo-controlled studies of
child and adolescent major depression. Only studies that used reliable diagnostic
and recovery parameters were included. RESULTS: Few well-designed studies have
compared placebo and tricyclic antidepressants in the treatment of major
depressive disorder in children and adolescents. However, results consistently
suggest that tricyclic antidepressants are not efficacious. Early results of
double-blind placebo-controlled trials with fluoxetine and paroxetine have shown
a significant drug effect. However, the results are inconsistent, which could
reflect the ways that response to medication is defined, the ways that rating
scales measure recovery, and uncertainties of dosing strategies with second
generation antidepressants. Hypothesized reasons for the unique response pattern
in youths include the changing hormonal status of children, the differential
maturation of the noradrenergic versus serotonergic neurotransmitter systems, and
the possibility that a large proportion of depressed youths are in the early
stages of bipolar disorder, which is not effectively treated by these
medications. CONCLUSIONS: Tricyclic antidepressants are not superior to placebo
for the treatment of child and adolescent major depressive disorder. Although two
of three trials of second-generation antidepressants in this age group have had
negative results, data suggest that these drugs may be more promising. It is too
early in our investigation to know whether these agents will be effective in
treating major depressive disorder in children and adolescents.
PMID- 10783182
TI - Changes in use of valproate and other mood stabilizers for patients with
schizophrenia from 1994 to 1998.
AB - OBJECTIVE: The study describes changes over time in the adjunctive use of
valproate and other mood stabilizers-lithium, carbamazepine, and gabapentin-
among hospitalized psychiatric patients with a diagnosis of schizophrenia.
METHODS: For each calendar year from 1994 through 1998, data were drawn from a
database containing clinical and drug prescription information for every
inpatient in the adult civil facilities of the New York State Office of Mental
Health. RESULTS: In 1994 a total of 26.2 percent of inpatients diagnosed as
having schizophrenia received a mood stabilizer, compared with 43.4 percent in
1998. In 1994 lithium was the most commonly prescribed mood stabilizer, for 13.2
percent of patients, followed by valproate, for 12.3 percent. In 1998 valproate
was the most commonly prescribed, for 35 percent of patients, followed by
lithium, for 11.3 percent. On average, patients received valproate for about two
thirds of their hospital stay, at a mean dose of 1,520 mg per day. CONCLUSIONS:
The adjunctive use of valproate nearly tripled from 1994 to 1998 among patients
with a diagnosis of schizophrenia. Valproate has become the most commonly
prescribed mood stabilizer for this population, despite the paucity of evidence
in the literature for efficacy in this use. Controlled clinical trials are needed
to examine the adjunctive use of mood stabilizers, in particular valproate, among
patients with schizophrenia.
PMID- 10783183
TI - Effects of substance dependence on outcomes of patients in a randomized trial of
two case management models.
AB - OBJECTIVE: The effectiveness of a community-based intensive clinical case
management program was compared with that of a hospital-based expanded brokerage
case management program for seriously mentally ill adults with and without
substance dependence. METHODS: The sample of 268 frequently hospitalized
psychiatric patients was recruited during acute psychiatric hospitalization. More
than half of the sample (53 percent) was diagnosed as having at least one current
DSM-III-R substance dependence disorder co-occurring with their primary major
mental disorder. Subjects were stratified by substance dependence status and
randomly assigned to one of the case management programs. They were interviewed
before hospital discharge and at one, two, and six months after discharge to
assess psychosocial and drug use variables. Subjects' service use was examined
for the six months before and after hospitalization. RESULTS: The hypothesis that
substance-dependent subjects would benefit more from intensive clinical case
management was not supported. Substance dependence predicted negative outcomes
independent of the case management intervention. The hypothesis that the two case
management approaches would be equally effective for subjects not dependent on
substances was also not borne out. Intensive clinical case management was the
superior treatment for subjects who were not dependent on substances. Fewer of
them required psychiatric hospitalization in the six-month postdischarge period
than in the six-month period before hospital admission. CONCLUSIONS: The negative
outcomes for substance-dependent subjects in both programs suggest that the two
case management models were relatively ineffective for these patients. Results
suggest that intensive clinical case management can be effective within the first
six months for nondependent adults with serious mental illness.
PMID- 10783184
TI - Comparing outcomes of major models of police responses to mental health
emergencies.
AB - OBJECTIVE: The study compared three models of police responses to incidents
involving people thought to have mental illnesses to determine how often
specialized professionals responded and how often they were able to resolve cases
without arrest. METHODS: Three study sites representing distinct approaches to
police handling of incidents involving persons with mental illness were examined
Birmingham, Alabama; and Knoxville and Memphis, Tennessee. At each site, records
were examined for approximately 100 police dispatch calls for "emotionally
disturbed persons" to examine the extent to which the specially trained
professionals responded. To determine differences in case dispositions, records
were also examined for 100 incidents at each site that involved a specialized
response. RESULTS: Large differences were found across sites in the proportion of
calls that resulted in a specialized response-28 percent for Birmingham, 40
percent for Knoxville, and 95 percent for Memphis. One reason for the differences
was the availability in Memphis of a crisis drop-off center for persons with
mental illness that had a no-refusal policy for police cases. All three programs
had relatively low arrest rates when a specialized response was made, 13 percent
for Birmingham, 5 percent for Knoxville, and 2 percent for Memphis. Birmingham's
program was most likely to resolve an incident on the scene, whereas Knoxville's
program predominantly referred individuals to mental health specialists.
CONCLUSIONS: Our data strongly suggest that collaborations between the criminal
justice system, the mental health system, and the advocacy community plus
essential services reduce the inappropriate use of U.S. jails to house persons
with acute symptoms of mental illness.
PMID- 10783185
TI - Comparing quality of mental health care for public-sector and privately insured
populations.
AB - OBJECTIVE: This study examined the methodological difficulties of comparing
quality of care in large health care systems. It demonstrated methods for
measuring quality of mental health care and, using these measures, compared
patients from Department of Veterans Affairs (VA) hospitals with privately
insured patients. METHODS: Individuals receiving VA inpatient mental health care
during the first six months of each fiscal year from 1993 to 1997 were identified
from discharge abstracts. A similar cohort of privately insured individuals was
identified using MEDSTAT's MarketScan database from 1993 to 1995. Individuals in
both cohorts were tracked for six months after discharge. Length of stay,
readmission rates, and access to outpatient services were calculated. RESULTS:
The private sector outperformed VA on most quality measures, although differences
were modest and can likely be explained by the greater severity of illness and
social disadvantages of VA patients. Readmission rates increased considerably
over time in the private sector, whereas they declined for VA patients. Quality
measures varied by diagnosis, with VA performing better than the private sector
in treating patients diagnosed with substance abuse and mental disorders not
elsewhere classified but worse in treating patients diagnosed with depression.
CONCLUSIONS: Although the private sector modestly outperformed VA on most quality
measures, VA treats a more troubled population, and it improved markedly over
time compared with the private sector. As health systems strive to reduce costs
of care, methods for comparing and evaluating the quality of care become
increasingly important. However, methodological challenges remain substantial.
PMID- 10783186
TI - A Delphi approach to describing service models of community mental health
practice.
AB - OBJECTIVE: The activities of mental health practitioners are poorly understood
and described because of a lack of generally accepted and understandable
categories. Greater precision is needed for accountability, planning, and
evaluation. The objective of this study was to identify a valid and reliable set
of categories to describe the clinical work practices of intensive case managers
in the United Kingdom. METHODS: Eight intensive case managers participated in a
Delphi process to produce a set of categories that described their clinical work
practices. They each completed three questionnaires and participated in a final
group discussion. RESULTS: The initial open questionnaire generated 38 potential
categories after exact duplicates were removed. In round 2, the intensive case
managers each rated the 38 categories from 1 to 5 (essential to unimportant). A
high degree of consensus on the relative importance of the 38 suggested practice
categories was rapidly achieved. In round 3, they re-rated the categories in the
light of group medians and their own round 2 ratings. In a structured face-to
face discussion group, the intensive case managers then reduced the 38 potential
categories to ten comprehensive and mutually exclusive categories that were
judged to adequately and accurately reflect work practices. They were housing,
finance, daily living skills, criminal justice system, occupation and leisure,
engagement, physical health, caregivers and significant others, specific mental
health intervention or assessment, and medication. CONCLUSIONS: Delphi methods
were effective and relatively straightforward in producing an agreed-on set of
categories with which to record clinical activity and inform care planning.
PMID- 10783187
TI - Treatment of acute schizophrenia in open general medical wards in Jamaica.
AB - OBJECTIVE: The study assessed the efficacy of treating acute psychotic illness in
open medical wards of general hospitals. METHODS: The sample consisted of 120
patients with schizophrenia whose first contact with a psychiatric service in
Jamaica was in 1992 and who were treated as inpatients during the acute phase of
their illness. Based on the geographic catchment area where they lived, patients
were admitted to open medical wards in general hospitals, to psychiatric units in
general hospitals, or to acute care wards in a custodial mental hospital. At
first contact, patients' severity of illness was assessed, and sociodemographic
variables, pathways to care, and legal status were determined. At discharge and
for the subsequent 12 months, patients' outcomes were assessed by blinded
observers using variables that included relapse, length of stay, employment
status after discharge, and clinical status. RESULTS: More than half (53 percent)
of the patients were admitted to the mental hospital, 28 percent to general
hospital medical wards, and 19 percent to psychiatric units in general hospitals.
The three groups did not differ significantly in geographic incidence rates,
patterns of symptoms, and severity of psychosis. The mean length of stay was 90.9
days for patients in the mental hospital, 27.9 days in the general hospital
psychiatric units, and 17.3 days in the general hospital medical wards. Clinical
outcome variables were significantly better for patients treated in the general
hospital medical wards than for those treated in the mental hospital, as were
outpatient compliance and gainful employment. CONCLUSIONS: While allowing for
possible differences in the three patient groups and the clinical settings, it
appears that treatment in general hospital medical wards results in outcome that
is at least equivalent to, and for some patients superior to, the outcome of
treatment in conventional psychiatric facilities.
PMID- 10783188
TI - The cost of access to mental health services in managed care.
AB - Managed care has controlled the cost of specialty mental health services, but its
impact on access to care is not well described. In a retrospective design, the
study used empirical data to demonstrate a direct relationship between managed
care plans' claims costs per member per month and the proportion of plan members
who use specialty mental health services annually. Each increment of $1 per
member per month in spending on claims was associated with a.9 percent increase
in the proportion of enrollees receiving specialty mental health treatment. These
data raise concerns that plans with low per-member per-month costs may unduly
restrict access to specialty treatment.
PMID- 10783189
TI - Subjective experiences of clozapine treatment by patients with chronic
schizophrenia.
AB - A 37-item survey covering a variety of somatopsychic domains was constructed to
explore patients' subjective response to treatment with clozapine. The survey was
administered to 130 patients with diagnoses of chronic schizophrenic or
schizoaffective disorders who were on a stable clozapine regimen. The majority
reported improvement in their level of satisfaction, quality of life, compliance
with treatment, thinking, mood, and alertness. Most patients reported worsening
in nocturnal salivation, and smaller numbers reported worsening in various
gastrointestinal and urinary symptoms and weight gain. This general health survey
highlights the patients' positive regard for clozapine, despite adverse bodily
experiences. Subjective reports are a useful component of outcome measures of
drug treatment.
PMID- 10783190
TI - An assessment of clinical practice of clozapine therapy for veterans.
AB - Clozapine therapy for 2,996 patients with treatment-refractory schizophrenia was
examined over a five-year period in the Veterans Affairs health care system.
Patients were assessed with the Brief Psychiatric Rating Scale (BPRS) and the
Abnormal Involuntary Movement Scale (AIMS). BPRS scores, which were available for
522 patients, indicated a significant improvement, as did AIMS scores, which were
available for 252 patients. Compared with individuals who showed a modest
improvement, those with a more robust response to clozapine had higher initial
BPRS scores and were three times more likely to have been suicidal in the month
before starting clozapine therapy.
PMID- 10783191
TI - Acceptability of telepsychiatry to a rural population.
AB - Sixty-seven residents of a rural Midwestern state were surveyed by telephone to
determine which factors influence their willingness to receive mental health
services through live, two-way audio and video transmission. Two-thirds of the
survey respondents were willing to participate in telepsychiatry. Many expressed
reluctance, however. They were concerned about maintaining confidentiality, and
they perceived telepsychiatry as impersonal. Medicare enrollees and older survey
respondents were less willing than younger respondents to endorse the use of
telemedicine.
PMID- 10783192
TI - Unusual case report: Nonpharmacologic effects of sildenafil.
AB - Sildenafil (Viagra), by virtue of its conflict-laden symbolic meanings, may be
particularly likely to have psychosocial consequences, either therapeutic or
disruptive. The author presents two cases of men in their mid-seventies who took
sildenafil and who were admitted to a locked geropsychiatry unit because of
homicidal ideation toward their wives that occurred while they were not under the
direct effect of the drug. In one case, a wife's rejection of her husband's
advances seemed to uncover many hidden resentments that they bore toward each
other. In the other, sildenafil failed to restore potency to a patient with
diabetes, and he developed a jealous delusion that his wife was having an affair.
PMID- 10783193
TI - The high cost of care.
PMID- 10783195
TI - The high cost of care
PMID- 10783194
TI - Involuntary hospitalization or aversive incarceration?
PMID- 10783196
TI - "Patient" versus "client".
PMID- 10783197
TI - "Patient" versus "client".
PMID- 10783198
TI - "Patient" versus "Client"
PMID- 10783199
TI - The corporate life.
PMID- 10783200
TI - Separating subculture from psychopathology.
PMID- 10783201
TI - The corporate life
PMID- 10783202
TI - Ideas of reference about newscasters.
PMID- 10783203
TI - Clinical trials in acute myocardial infarction: should we adjust for baseline
characteristics?
AB - BACKGROUND: Clinical trials concerning acute myocardial infarction often evaluate
short-term death. Several baseline characteristics are predictors of death, most
notably age. Adjustment for one or more predictors in a multivariable analysis
may be considered to correct the estimate of the treatment effect for any
imbalance that by chance may have occurred between the randomized groups.
Moreover, adjustment results in a stratified estimate of the effect of treatment.
METHODS AND RESULTS: The effects of adjustment (correction for imbalance and
stratification) were studied with logistic regression analysis in the Global Use
of Strategies to Open Occluded Coronary Arteries (GUSTO)-I trial. The primary end
point was 30-day death, which occurred in 6.3% of 10,348 patients randomly
assigned to tissue plasminogen activator and 7.3% of 20,162 patients randomly
assigned to streptokinase thrombolytic therapy. This is equivalent to an
unadjusted odds ratio of 0.853. No significant imbalance had occurred for any of
17 baseline characteristics considered, including well-known demographic,
presenting, and history characteristics. Adjusted for age, the odds ratio was
0.829, which is an 18% increase in estimated effect on the logistic scale. When
adjusted for 17 characteristics, the odds ratio was 0.820, an increase of 25%.
The increase in effect estimate was largely explained by the stratification
effect and only partly by imbalance of predictors. CONCLUSIONS: Adjustment for
predictive baseline characteristics, even when largely balanced, may lead to
clearly different estimates of the treatment effect on mortality rates.
Adjustment for important predictors such as age is recommended in clinical trials
studying patients with acute myocardial infarction.
PMID- 10783204
TI - Appropriate outcome measures in trials evaluating treatment of atrial
fibrillation.
AB - BACKGROUND: Atrial fibrillation (AF) is a widespread disease that has only
recently received the focused attention of arrhythmia specialists despite being
the most frequently occurring significant cardiac arrhythmia. METHODS AND
RESULTS: The wide variety of trial designs used to evaluate AF treatment is a
reflection of the diverse outcomes associated with this condition. The best
trials assess the impact of treatment on a clearly measured outcome that is of
clinical relevance to patients. This review discusses the different designs of AF
treatment trials and analyzes the utility of the various outcomes that can be
assessed. CONCLUSIONS: A sensible goal of AF treatment is to reduce the frequency
of recurrences and to prolong the time between them. The most appropriate trials
focus on AF recurrences that are symptomatic and therefore relevant to the
patient. We still do not know if there is value in AF prevention, beyond
preventing symptoms. However, ongoing and future studies will show whether AF
suppression reduces the longer-term risks of stroke or death and improves patient
quality of life. Cost of care will increasingly be studied in future trials of AF
management.
PMID- 10783205
TI - Clinical trials in acute myocardial infarction: when should we adjust for
baseline characteristics?
PMID- 10783206
TI - Understanding racial differences in cardiovascular care and outcomes: issues for
the new millennium.
PMID- 10783207
TI - Monitoring trends in severity of acute myocardial infarction: challenges for the
next millennium.
PMID- 10783208
TI - When is angina good? Preconditioning in acute myocardial infarction.
PMID- 10783210
TI - Transpulmonary passage of Albunex as a marker of intracardiac hemodynamics and
outcome in chronic congestive heart failure.
AB - BACKGROUND: Aggressive management to reduce pulmonary artery systolic pressure
(PASP) and pulmonary capillary wedge pressure (PCWP) reduces hospitalization
rates and is crucial for patients awaiting transplantation but may require
periodic invasive monitoring with right heart catheterization. METHODS: The
purpose of this study was to define the relation of transpulmonary passage of
Albunex (Mallinckrodt Medical, St Louis, Mo) to intracardiac hemodynamics and
clinical outcome in patients with chronic congestive heart failure (CHF).
Patients (n = 38) with chronic CHF underwent graded dobutamine infusion
(baseline, 5, 10, 20 microg/kg per minute; 5-minute stages) with 5.0 mL Albunex
injected intravenously at each stage. The dobutamine dose at which Albunex
appeared in the left ventricle was determined. All patients had right heart
catheterization to determine PASP and PCWP. RESULTS: Transpulmonary passage of
Albunex at baseline or at 5 microg/kg per minute dobutamine infusion predicted
PCWP <20 mm Hg with a positive predictive value of 100% and a negative predictive
value of 79%. Initial appearance of Albunex in the left ventricle at a dobutamine
dose of 20 microg/kg per minute or failure to appear at any dose predicted a PCWP
>20 mm Hg with a positive predictive value of 100% and a negative predictive
value of 94%. No patient with Albunex passage at baseline sustained a major
adverse event. Major adverse events occurred in 11 of 21 patients in whom Albunex
either failed to cross or crossed the pulmonary bed at a dose of 20 microg/kg per
minute of dobutamine. CONCLUSION: In patients with chronic CHF, transpulmonary
passage of Albunex during dobutamine infusion can be used to predict both
elevated and normal intracardiac pressures and to identify a subset of patients
at high risk for an adverse outcome.
PMID- 10783209
TI - Strategy for optimal aortic regurgitation quantification by Doppler
echocardiography: agreement among different methods.
AB - BACKGROUND: Although different Doppler methods have been validated for aortic
regurgitation quantification, the benefit of combining information from different
methods has not been defined. METHODS: Our study included 2 phases. In the
initial phase (60 patients), Doppler parameters (jet width, short-axis jet area,
apical jet area, regurgitant fraction from pulmonary and mitral flow, and
deceleration slope) were correlated with angiography; range values for each
severity grade were defined and intraobserver and interobserver and intermachine
variability were studied. In the validation phase (158 patients), defined value
ranges were prospectively tested and a strategy based on considering as the
definitive severity grade that in which the two best methods agreed was tested.
RESULTS: Jet width had the best correlation with angiography (r = 0.91), and its
ratio with the left ventricular outflow diameter did not improve the correlation
(r = 0.85) and decreased reproducibility. Apical jet area and regurgitant
fraction from pulmonary flow permitted acceptable quantification (r = 0.87 and
0.86, respectively) but with worse reproducibility. The other methods were not
assessable in 20% to 30% of studies. Concordance with angiography decreased in
jet width when the jet was eccentric (90% vs 77%, P <.01), in apical jet area
when mitral valve disease was present (84% vs 65%, P <.02), and in short-axis jet
area and regurgitant fraction from pulmonary flow with concomitant aortic
stenosis (77% vs 44%, P <.002 and 77% vs 53%, P <.02, respectively). Agreement
with angiography was very high (94 [95%] of 99) when severity grade coincided in
both jet width and apical jet area. In 59 cases without concordance, regurgitant
fraction from pulmonary flow was used as a third method. Overall, this strategy
permitted concordance with angiography in 146 patients (92%). CONCLUSIONS: Jet
width is the best predictor in aortic regurgitation quantification by Doppler
echocardiography. However, better results were obtained when a strategy based on
concordance between jet width and another Doppler method was established,
particularly when the jet was eccentric.
PMID- 10783211
TI - Prehospital delay time in acute myocardial infarction: an exploratory study on
relation to hospital outcomes and cost.
AB - BACKGROUND: Short prehospital delay is associated with improved outcomes in
myocardial infarction, but the impact on cost has not been tested. Shortening
delay time could reduce health care expenditures. METHODS AND RESULTS: Two
hundred ninety-eight patients were examined with the use of a historic
prospective design at 2 hospital sites. A secondary analysis was performed that
used patients with confirmed myocardial infarction from the National Register of
Myocardial Infarction and direct and indirect costs from the accounting system at
the hospitals. Chi-square, Mann Whitney U, and Fisher exact tests were used for
comparisons. Delay and 4 sets of variables were regressed on cost with the
significant predictors used to construct a final model. The mean age was 71 +/-
14 years old; 62% were men. There were no major differences in demographics,
cardiac history, risk factors, and admission characteristics between short and
long delayers. Resource utilization and clinical outcomes were similar between
the 2 groups; there was no difference in cost. Additional diagnostic procedures
(odds ratio 2.92; 95% confidence interval 1.65-5.15) and complications (odds
ratio 3.43; 95% confidence interval 2.03-5.82) were significant predictors of
cost. Delay was not a predictor of high cost. CONCLUSIONS: Short prehospital
delay was not associated with improved clinical outcomes, nor did it predict
cost. Explanations include (1) the low utilization of early reperfusion therapy
in the short delay group, (2) the study lacked sufficient power to detect a
difference in cost between short and long delayers, and (3) the severity of
illness could not be adequately measured. This issue warrants further study
because of the potential impacts on health care expenditures.
PMID- 10783212
TI - Inappropriate therapy from atrial fibrillation and sinus tachycardia in automated
implantable cardioverter defibrillators.
AB - BACKGROUND: Inappropriate therapy from supraventricular tachyarrhythmias (atrial
fibrillation [AF] and sinus tachycardia [ST]) in patients with implanted
cardioverter defibrillators is a major challenge. We tested the performance of
stability algorithms from 3 manufacturers for episodes of inappropriate therapy
delivered because of AF and an onset algorithm for all episodes of inappropriate
therapy caused by ST. METHODS: Therapy was classified as caused by ventricular
tachycardia (VT), ST, or AF from review of stored intracardiac electrograms,
history, clinical information, and R-R data before study inception. By using 30
to 60 R-R intervals before therapy, sensitivity and specificity for a family of
stability values and percentage of onset values were calculated for each
manufacturer and receiver operating characteristic curves generated. RESULTS: Of
the 217 patients monitored, 62 (29%) received inappropriate therapy, and 40 had
complete R-R information available. Of the 40 patients, 21 patients received
therapy for AF, 19 for ST, and 1 patient for noise; 15 (38%) also received
appropriate therapy for VT. We analyzed 83 episodes of VT from 18 patients, 94
episodes of AF from 21 patients, and 56 episodes of ST from 19 patients.
Specificity, in the clinically relevant sensitivity range of >/=95%, was
comparable across manufacturers at about 40%. An onset value of 80% was
associated with 91% sensitivity and 95% specificity for the specific algorithm
tested. CONCLUSIONS: Inappropriate therapy is a common problem in implantable
cardiac defibrillators. The performance of the stability algorithms used to
differentiate AF from VT was less than ideal, though comparable across
manufacturers. The onset algorithm accurately differentiates ST from VT.
PMID- 10783213
TI - Determinants of outcome in patients with sustained ventricular tachyarrhythmias:
the antiarrhythmics versus implantable defibrillators (AVID) study registry.
AB - BACKGROUND: The prognosis of patients with sustained ventricular tachyarrhythmias
varies according to clinical characteristics. We sought to identify predictors of
survival in a large population of patients with documented sustained ventricular
tachyarrhythmias not related to reversible or correctable causes included in the
Antiarrhythmics Versus Implantable Defibrillators (AVID) Registry. METHODS AND
RESULTS: We analyzed the impact of 36 demographic, clinical, and discharge
treatment variables on the outcome for 3559 patients. Survival status was
assessed with the use of the National Death Index. Multivariate analyses were
performed with the use of the Cox proportional hazards model. After a mean follow
up of 17 +/- 12 months, 631 patients died. Actuarial survival was 0.86 (95%
confidence interval [CI] 0.85 to 0.88), 0.79 (95% CI 0.78 to 0.81), and 0.72 (95%
CI 0.70 to 0.74) at 1, 2, and 3 years. Multivariate predictors of worse survival
included older age, severe left ventricular dysfunction, lower systolic blood
pressure, history of congestive heart failure, diabetes, smoking or atrial
fibrillation, and preexistent pacemaker. The hemodynamic impact of the qualifying
arrhythmia was not a predictor of outcome. Defibrillator implantation and
hospital discharge while the patient was taking a beta-blocker or an angiotensin
converting enzyme inhibitor were associated with better prognosis. CONCLUSIONS:
Despite therapeutic advances, the mortality rates of patients with sustained
ventricular tachyarrhythmias remain high. Prognosis depends on the severity of
underlying heart disease, as reflected by the extent of left ventricular
dysfunction and the presence of heart failure. Well-tolerated ventricular
tachycardia in patients with structural heart disease does not carry a
significantly better prognosis than ventricular tachyarrhythmia with more severe
hemodynamic consequences.
PMID- 10783214
TI - Clinical study to investigate the predictive parameters for the onset of atrial
fibrillation in patients with essential hypertension.
AB - BACKGROUND: The risk factors involved in the onset of atrial fibrillation (AF)
are well known, but the predictive clinical and paraclinical parameters for the
onset of AF in hypertensive patients have not been investigated specifically.
METHODS AND RESULTS: We retrospectively analyzed 97 consecutive patients with
hypertension and no known history of AF or cardiovascular events who attended the
cardiology outpatient clinic. The analysis was based on clinical data, the
noninvasive ambulatory 24-hour measurement of blood pressure (AMBP), a standard
12-lead electrocardiogram, and a Doppler echocardiogram. After a mean follow-up
of 25 +/- 3 months, 19 (19. 5%) patients had AF, 3 (15.8%) of whom had a
cerebrovascular accident. The patients with AF were older than the others and
their AMBP showed higher mean systolic diurnal and nocturnal blood pressures,
though no differences in the clinical blood pressure readings were present. On
the electrocardiogram, the maximum duration of the P wave and its dispersion were
more prolonged in the patients with AF. On the Doppler echocardiogram, left
ventricular mass and left atrial dimension were higher in the patients with AF,
and the A-wave velocity of diastolic mitral flow was reduced in these patients.
In the multivariate analysis, age (odds ratio 3.28, P <.001), diurnal systolic
blood pressure (odds ratio 1.35, P <.01) and nocturnal systolic blood pressure
(odds ratio 1.16, P <.01), maximum duration of the P wave (odds ratio 2.09, P
<.01), dispersion of the P wave (odds ratio 2.52, P <.001), echocardiographic
left ventricular mass (odds ratio 1.43, P <.01), left atrial dimension (odds
ratio 2.81, P <.001), and velocity of the A wave (odds ratio 2. 24, P <.01) were
independent predictors for the onset of AF. After correction for age, maximum
duration of the P wave (odds ratio 1.34, P <.01), dispersion of the P wave (odds
ratio 1.63, P <.001), and the velocity of the A wave (odds ratio 1.42, P <.01)
remained independent predictors for the onset of AF. CONCLUSIONS: In patients
with hypertension, age and the level of diurnal and nocturnal systolic blood
pressures measured by 24-hour AMBP are important independent predictors for the
onset of AF. Independent of age, increases in left atrial dimension and left
ventricular mass, prolongation of the maximum duration and dispersion of the P
wave and reduced A-wave velocity are also predictors for the onset of AF.
PMID- 10783215
TI - Collaborative angiographic patency trial of recombinant staphylokinase (CAPTORS).
AB - BACKGROUND: We undertook an angiographic, dose-finding study of staphylokinase
(SAK42D variant) to evaluate its efficacy and safety in patients with acute ST
segment myocardial infarction. METHODS AND RESULTS: Patients were studied within
6 hours of symptom onset and received SAK42D as a 30-minute infusion with 20% of
the total dose given as a bolus. Eighty-two patients with a median age of 60
years (interquartile range 52 to 69 years), 84% male and 43% with an anterior
myocardial infarction, were studied at a median time from symptom onset of 2.7
hours. There was a high degree of Thrombolysis in Myocardial Infarction (TIMI) 3
flow achieved with 15 mg of SAK42D, that is, 62%. Therefore after 21 patients had
been studied at this dose the next dose of 30 mg was used and 65% TIMI 3 patency
was achieved. At the peak dose of 45 mg, TIMI 3 90-minute patency was 63%. There
were no allergic reactions, and no patient had intracranial hemorrhage. Four
patients had major and 9 moderate bleeding during the study; 2 of the major and 5
of the moderate bleeding events occurred within 48 hours of commencement of
treatment. The majority (62%) of these were related to vascular instrumentation,
and there was no relation between the extent of bleeding and dose of SAK42D used.
Forty-five minutes after cessation of SAK42D, there were small percent decrements
in plasma fibrinogen and plasminogen levels that did not reach statistical
significance. However, there were dose-related changes in alpha(2) anti-plasmin
that revealed a borderline significant reduction that was dose related (P =.053).
CONCLUSION: These data revealed similar fibrinolytic efficacy across a 3-fold
increment in dose, indicating that this study operated on a flat portion of the
dose-response curve. The favorable efficacy/safety profile achieved with
staphylokinase is encouraging, and further investigation is warranted.
PMID- 10783216
TI - Reduced thrombus burden with abciximab delivered locally before percutaneous
intervention in saphenous vein grafts.
AB - BACKGROUND: Existing thrombus can complicate percutaneous saphenous vein graft
(SVG) intervention. Local delivery of thrombolytics has been used to reduce the
thrombus burden often associated with these interventions. We sought to determine
whether local delivery of a platelet glycoprotein IIb/IIIa inhibitor is feasible
and can reduce thrombus burden before percutaneous SVG intervention. METHODS: We
performed a multicenter pilot study of abciximab (0.25 mg/kg) given by local
delivery catheter before percutaneous intervention for de novo SVG stenoses
followed by intravenous infusion. All patients (n = 58) had >/=60% stenosis and
Thrombolysis In Myocardial Infarction (TIMI) grade >0 flow in an SVG of 3 to 4 mm
in diameter. Percent diameter stenosis, TIMI thrombus grade, and TIMI flow grade
were measured before and after delivery of abciximab and after intervention.
RESULTS: Median percent diameter stenosis improved from 69% to 45% (P =.0001)
after local delivery, and TIMI thrombus grade >/=1 incidence reduced from 68% to
34% (P =.0001). TIMI flow grade was not significantly affected (P =.12). All
patients had a successful intervention (=50% residual stenosis). CONCLUSIONS:
Local abciximab delivery before percutaneous SVG intervention is associated with
significantly reduced thrombus burden, significantly improved percent diameter
stenosis, and excellent acute procedural results. Further studies of this
approach are warranted to define its clinical utility.
PMID- 10783217
TI - Clinical and angiographic outcome after angiography-guided stent placement in
small coronary vessels.
AB - BACKGROUND: Although it is widely accepted that stenting confers favorable
angiographic and clinical results in coronary arteries >/=3.0 mm in diameter, the
outcome of stent placement in smaller vessels remains largely unclear. METHODS
AND RESULTS: We sought to specifically determine the early and long-term clinical
outcomes in a large series of 197 consecutive patients who underwent stent
placement in 207 vessels <3.0 mm in diameter. Procedural success, accomplished in
97.3%, was accompanied by a significant reduction in lesion severity from 85% +/-
9% before to 3% +/- 7% diameter stenosis after the procedure (P =.0001) and a
0.5% incidence of subacute stent thrombosis. At 1 and 2 years of follow-up,
survival rate without major target lesion-driven events was observed in 77.3% and
73.9% of patients, respectively. Repeat revascularization procedures accounted
for most of these events; cardiac deaths (including those related to subacute
stent thrombosis) and late (>30 days) myocardial infarctions were infrequent
(2.4% and 1.0%, respectively). The 6-month angiographic binary instent restenosis
rate was 30.1%. On multivariate analysis, diabetes mellitus (P =. 0275), small
baseline reference vessel size (P =.0300), and stent size =2.7 mm (P =.0111)
were independently associated with an increased instent restenosis rate.
CONCLUSIONS: Optimal angiography-guided coronary stenting of vessels <3.0 mm in
diameter in association with the stringent use of a poststent combined aspirin
ticlopidine antiplatelet regimen confers a low risk of stent thrombosis, an
acceptable incidence of angiographic instent restenosis, and a favorable long
term clinical outcome.
PMID- 10783218
TI - Severity of coronary artery disease in black and white male veterans and
likelihood of revascularization.
AB - BACKGROUND: Many reports in the literature have found the use of invasive cardiac
procedures in black patients to be less common than in white patients. These
reports tend to have small numbers of black patients compared with white patients
or rely on the information contained in claims or administrative data. METHODS
AND RESULTS: Cardiac catheterization reports were reviewed in a Veterans
Administration hospital that serves a large number of black patients. After
review of the medical histories and hemodynamic and angiographic findings in 726
black and 734 white male veterans, data were collected to determine recommended
and actual therapy. Death was assessed after a 4- to 10-year follow-up period.
White patients were more likely to have significant coronary artery lesions than
black patients. Multivariate analysis showed that the likelihood of patients
actually having percutaneous transluminal coronary angioplasty or coronary artery
bypass surgery did not differ by ethnicity when controlling for disease extent or
severity. Coronary artery bypass surgery was associated with decreased mortality
rates for both black and white patients. Although short-term death in blacks was
not different from whites, blacks had an increased long-term risk for death.
CONCLUSIONS: After coronary angiography, black veterans and white veterans appear
to undergo revascularization procedures related to the severity of disease. The
decreased long-term life expectancy of black men as compared with whites is not
necessarily explained by the presence of or treatment for coronary artery disease
in this population.
PMID- 10783219
TI - Race and sex differences in the management of coronary artery disease.
AB - Although numerous studies have documented race and sex differences in the
treatment of coronary artery disease, the available analyses have not been
comprehensively evaluated. In this review, we summarize prior estimates of race
and sex disparities in the utilization of standard tests and therapies, and we
evaluate studies of factors that may contribute to gaps in care. The studies
presented consistently demonstrate that blacks and women with coronary artery
disease, compared with whites and men, are substantially less likely to receive
standard interventions. Studies also indicate that racial differences relate in
part to socioeconomic factors, process-of-care variables, and patient
preferences, whereas sex differences relate in part to clinical factors. In both
cases, however, our understanding is limited by deficiencies in currently
available datasets. Moreover, factors that have been shown to contribute to race
and sex disparities in medical care fail to explain them fully. In both cases,
physician decision-making appears to contribute as well, suggesting that
subconscious biases may contribute to treatment disparities. We conclude by
proposing initiatives to remedy race and sex disparities in medical care. Efforts
should focus on increasing physician awareness of this problem. Studies should
gather data that are currently unavailable for analysis, including detailed
clinical variables and patient-level socioeconomic information. Finally, novel
quality assurance programs, designed to evaluate and improve the care of blacks
and women with coronary artery disease, should be promptly undertaken.
PMID- 10783220
TI - Age and outcome after acute coronary syndromes without persistent ST-segment
elevation.
AB - BACKGROUND: Although age is the most important variable associated with death
among patients with persistent ST-segment elevation, its impact on outcome among
patients without persistent ST-segment elevation remains unknown. Moreover, the
impact of age on the efficacy of antiplatelet therapy with eptifibatide is
unknown. METHODS: We analyzed the impact of increased age on outcome (death or
[re]infarction) among patients enrolled in PURSUIT (Platelet Glycoprotein
IIb/IIIa in Unstable Angina Receptor Suppression Using Integrilin Therapy), a
prospective, randomized study comparing placebo versus eptifibatide therapy in
acute coronary syndromes without persistent ST-segment elevation. The 9461
patients were divided into 10-year age groups: <50, 50-59, 60-69, 70-79, and
>/=80. In addition, we examined whether age had an impact on the efficacy of
eptifibatide therapy. RESULTS: Eptifibatide improved outcome at 30 days (P =.04).
There was no interaction among age and treatment (placebo vs eptifibatide) and
adjusted outcome (P =.16 for death or [re]infarction at 30 days). Despite their
worse clinical profile, older patients were less likely to undergo coronary
angiography at 30 days: 936 (71%), 1489 (68%), 1969 (65%), 1357 (57%), and 193
(38%) in the respective age groups. Death or (re)infarction at 30 days occurred
in 121 (9%), 255 (12%), 447 (15%), 460 (19%), and 134 (26%) in the respective age
groups, and at 6 months in 149 (11%), 301 (14%), 547 (18%), 575 (24%), and 162
(32%). For a 10-year difference in age group, the adjusted odds for death or
(re)infarction were greater by 33% within 30 days and by 34% within 6 months.
These trends persisted for patients with or without myocardial infarction on
presentation. CONCLUSIONS: Age did not significantly affect the efficacy of
eptifibatide. Older age among patients with acute coronary syndromes was
associated with worse baseline characteristics, fewer invasive procedures, and
worse outcome.
PMID- 10783221
TI - Effect of leukocytosis at initial examination on prognosis in patients with
primary unstable angina.
AB - BACKGROUND: Leukocytosis with acute myocardial infarction at initial examination
predicts adverse prognosis, but it is unknown whether it predicts outcome in
patients with primary unstable angina. METHODS AND RESULTS: We studied 414
consecutive patients with unstable angina admitted through the emergency
department to telemetry and intensive care units of an urban academic hospital.
To study primary unstable angina, we excluded 134 patients with precipitants (eg,
urosepsis, pneumonia) that may cause leukocytosis. Of 280 patients, 96 (34%) had
leukocytosis (leukocyte count >10,000 per microL) at initial examination. A total
of 30 patients (11%) died and 47 (17%) died or had nonfatal myocardial infarction
within 12 months of initial examination. In a univariate Cox model, patients with
leukocytosis had a hazard ratio (HR) of 2.6 (95% confidence interval [CI] 1.3
5.4) for death by 1 year. In a multivariate Cox model the only significant
predictors of 1-year death were congestive heart failure at initial examination
(HR 7.8; 95% CI 2.8-22) and elevated creatinine (HR 2.7; 95% CI 1.3-5.7); in this
model, the relation between leukocytosis and prognosis was markedly attenuated
(HR 1.4; 95% CI 0.6-2.9). The adjusted HR for leukocytosis was 1.3 (95% CI 0. 7
2.3) for death or nonfatal MI by 1 year. CONCLUSIONS: Leukocytosis at initial
examination is associated with adverse prognosis in patients with primary
unstable angina. However, the association is confounded by other important
predictors of prognosis. Leukocytosis may be a marker of stress associated with
more severe cases of unstable angina or comorbid conditions.
PMID- 10783222
TI - Trends in severity of hospitalized myocardial infarction: the atherosclerosis
risk in communities (ARIC) study, 1987-1994.
AB - BACKGROUND: Declining mortality rates of coronary heart disease in the United
States could be attributable to declining incidence, declining severity, and/or
improvements in treatment. METHODS: We examined trends in severity of patients
hospitalized for myocardial infarction to characterize its contribution to this
decline by using data from the Atherosclerosis Risk in Communities (ARIC) study.
RESULTS: No significant change in the proportion having systolic blood pressure
<100 mm Hg or an abnormal pulse at presentation was noted. The proportion with ST
segment elevation on the initial electrocardiogram increased 10% per year (P
<.001), and the proportion with a diagnostic or evolving diagnostic
electrocardiogram abnormality increased 4% per year (P <.01); the proportion that
had a new Q-wave infarction develop remained unchanged. The mean peak creatine
kinase level decreased 5% per year (P <.001), the proportion with abnormal enzyme
levels decreased 10% per year (P <.001), and the proportion that met criteria for
definite myocardial infarction decreased 4% per year (P <.05). The proportion
that had cardiogenic shock decreased 10.9% per year (P <. 01), but the proportion
that had an acute episode of congestive heart failure was stable. CONCLUSIONS:
With stable hemodynamic indicators, worsening electrocardiographic indicators,
and improving enzymatic indicators, these results provide mixed support for
decreases in the severity of myocardial infarction.
PMID- 10783223
TI - Beneficial effect of prodromal angina pectoris is lost in elderly patients with
acute myocardial infarction.
AB - BACKGROUND: Prodromal angina pectoris occurring shortly before the onset of acute
myocardial infarction is associated with a favorable outcome by the mechanism of
ischemic preconditioning. Recent experiments have reported that the beneficial
effect of ischemic preconditioning are reversed in the aged heart. METHODS: We
studied 990 patients who underwent coronary angiography within 12 hours after the
onset of acute myocardial infarction. Patients were divided into 2 groups: those
aged <70 years (nonelderly patients, n = 722) and those aged >/=70 years (elderly
patients, n = 268). Prodromal angina in the 24 hours before infarction was found
in 190 of 722 nonelderly patients and in 66 of 268 elderly patients (26% vs 25%,
P =.61). RESULTS: In nonelderly patients, prodromal angina was associated with
lower peak creatine kinase levels (2438 +/- 1939 IU/L vs 2837 +/- 2341 IU/L, P
=.04), lower in-hospital mortality rates (3.7% vs 8.8%, P =.02), and better 5
year survival rates (P =. 007). On the contrary, in elderly patients there was no
significant difference in peak creatine kinase levels (2427 +/- 2142 IU/L vs 2256
+/- 1551 IU/L, P =.51), in-hospital mortality rate (21.2% vs 17. 4%, P =.49), and
5-year survival rates (P =.47). A multivariate analysis showed that prodromal
angina in the 24 hours before infarction was associated with 5-year survival rate
in nonelderly patients (odds ratio 0.49, P =.009) but not in elderly patients
(odds ratio l.12, P =.65). CONCLUSIONS: In nonelderly patients, prodromal angina
in the 24 hours before infarction was associated with a smaller infarct size and
better short- and long-term survival, suggesting a relation to ischemic
preconditioning. However, such a beneficial effect was not observed in elderly
patients.
PMID- 10783224
TI - Determinants of delayed improvement in exercise capacity after percutaneous
transvenous mitral commissurotomy.
AB - BACKGROUND: Percutaneous transvenous mitral commissurotomy (PTMC) results in
short-term hemodynamic and symptomatic improvements. We have previously shown
that the immediate symptomatic relief is related to the improvement in excessive
exercise ventilation. The exercise capacity, however, does not improve in the
short term but does improve gradually over several months. The pathophysiologic
basis for the delayed improvement in exercise capacity has not been fully
evaluated. METHODS: To elucidate the determinants of improvement in exercise
capacity late after PTMC, maximal ergometer exercise with respiratory gas
analysis and exercise hemodynamic measurements were performed in 22 patients with
symptomatic mitral stenosis before, immediately after, and 7 months after PTMC.
RESULTS: Mitral valve area increased from 0.9 +/- 0.2 cm(2) to 1.7 +/- 0.4 cm(2)
after PTMC (P <.01). Significant improvements were observed in symptoms, cardiac
output at peak exercise (6.6 +/- 1.5 L/min vs 8.6 +/- 1.9 L/min, P <.01), and
mean pulmonary artery pressure at peak exercise (54.1 +/- 15.6 mm Hg vs 42.3 +/-
9.5 mm Hg, P <.01) immediately after PTMC. Excessive exercise ventilation, as
assessed by the slope of the regression line between expired minute ventilation
and carbon dioxide output (VE-VCo(2)), decreased significantly from 38.2 +/- 8.2
to 33.3 +/- 4.9 (P <.01). There were no significant changes in peak oxygen uptake
(from 17.5 +/- 3.2 mL/kg per minute to 17.9 +/- 3.6 mL/kg per minute) immediately
after PTMC. At 7 months, improved mitral valve area, symptoms, cardiac output at
peak exercise, mean pulmonary artery pressure at peak exercise, and VE-VCo(2)
were unchanged compared with values immediate after PTMC. Significant improvement
was observed in peak oxygen uptake (19.7 +/- 3.0 mL/kg per minute [P <.01
compared with pre-PTMC or immediate post-PTMC values]). The increase in exercise
cardiac output or the decrease in pulmonary artery pressure was not correlated
with the late improvement in peak oxygen uptake. The short- or long-term
improvements in VE-VCo(2), however, were significantly correlated with the late
improvement in peak oxygen uptake. CONCLUSIONS: Our results suggest that
ventilatory improvement, not increased exercise cardiac output, contributed at
least in part to the late improvement in exercise capacity after PTMC.
PMID- 10783225
TI - Differential clinical prognostic classifications in dilated and ischemic advanced
heart failure: the EPICAL study.
AB - BACKGROUND: The clinical management of severe congestive heart failure (CHF)
should be graded according to the prognosis of each individual patient. Our
objective was to elaborate a prognostic rating system for severe CHF. METHODS:
The EPICAL program (Epidemiologie de l'Insuffisance Cardiaque Avancee en
Lorraine) identified patients with severe CHF defined by hospitalization
accompanied by class III/IV dyspnea, edema, or hypertension; an ejection fraction
=30% or a cardiothoracic index >/=60%. Baseline variables were tested in Cox
multivariate models. RESULTS: Patients with ischemic heart disease (n = 219) had
a lower 1-year survival rate (57.6%) than patients with dilated cardiomyopathy (n
= 182) (69. 1%). Multivariate analysis identified 5 prognostic factors for
ischemic CHF and 7 for CHF caused by dilated cardiomyopathy. These variables were
used to classify patients within prognostic subgroups of good (>75%),
intermediate, or poor (=25%) 1-year survival. CONCLUSION: A score for
prognostic prediction was further derived from readily available data to help
physicians improve decision making and to assist in clinical trials as a
stratification tool.
PMID- 10783226
TI - Myocardial integrated ultrasonic backscatter in patients with dilated
cardiomyopathy: prediction of response to beta-blocker therapy.
AB - BACKGROUND: Myocardial integrated backscatter (IB) imaging has been reported to
be useful for ultrasonic tissue characterization and delineation of myocardial
viability or fibrosis. beta-Blocker therapy has beneficial effects for patients
with dilated cardiomyopathy (DCM), but there are no clear findings that indicate
which patients with DCM will respond to this therapy. This study was performed to
evaluate whether myocardial IB analysis can predict the response to beta-blocker
therapy. METHODS AND RESULTS: We prospectively performed echocardiographic
examination with IB analysis in 29 patients with DCM (20 men, 9 women) before
starting bisoprolol therapy and in 15 normal subjects. Standard echocardiographic
examination and IB analysis in the left ventricular wall in the 2-dimensional
short-axis view were performed and the magnitude of cyclic variation (CV) of IB
and calibrated myocardial IB intensity (subtracted pericardial) were obtained
from the interventricular septum and the left ventricular posterior wall. Sixteen
patients responded to bisoprolol therapy and 13 did not respond after 12 months
of full-dose therapy. Calibrated myocardial IB intensity was lower in responders
relative to nonresponders in both the interventricular septum (responders, -20.1
+/- 3.6 dB vs nonresponders, -9.8 +/- 5.1 dB, P <.0001; controls, -20.1 +/- 4.4
dB) and posterior wall (responders, -20.6 +/- 3.6 dB vs nonresponders, -14.6 +/-
4.2 dB, P =.0002; controls, -22.7 +/- 3.3 dB). Also, the lower the myocardial
intensity in the interventricular septum or posterior wall, the better left
ventricular systolic function improved after beta-blocker therapy. However, CV
was lower in both DCM groups than in the controls, and CV in the interventricular
septum was lower in nonresponders than in responders (responders, 4.0 +/- 4.1 dB
vs nonresponders, -0.8 +/- 6. 1 dB, P <.02; controls, 8.3 +/- 2.4 dB). In
addition, CV in the posterior wall showed no difference between the 2 DCM groups
(responders, 5.6 +/- 1.3 dB vs nonresponders, 5.1 +/- 3.5 dB, P = not
significant; controls, 9.6 +/- 2.5 dB). Also, the percent fibrosis on right
ventricular endomyocardial biopsy specimens showed no distinctions between these
2 groups (responders, 25.1% +/- 16.1% vs nonresponders, 24.9% +/- 15.0%, P = not
significant). CONCLUSIONS: These findings suggest that left ventricular
myocardial IB data, especially IB intensity, provide useful information for
predicting the response to beta-blocker therapy in patients with DCM. However,
right ventricular endomyocardial biopsy findings do not appear to contribute to
discriminating between the 2 groups.
PMID- 10783227
TI - Relation of changes over time in ventricular size and function to those in
exercise capacity in patients with chronic heart failure.
AB - BACKGROUND: We studied the direction and magnitude of changes in left ventricular
(LV) cavity size and mass over time and whether these changes were related to
those in exercise performance in patients with chronic heart failure (CHF).
METHODS AND RESULTS: The study group was composed of 59 patients (55 men aged 58
+/- 10 years) with CHF and LV end-diastolic diameter (EDD) >55 mm. All underwent
echocardiography and a treadmill cardiopulmonary exercise test within a 4-week
interval (baseline) and again after a period of >/=4 months (median of 14
months). At baseline, the group as a whole had moderate to severe LV dysfunction
with an EDD of 70 +/- 9 mm, end-systolic diameter (ESD) of 60 +/- 11 mm, and LV
mass of 500 +/- 200 g. The mean peak oxygen consumption (Vo (2), 18 +/- 6 mL/kg
per minute) was unrelated to LV cavity size or mass. EDD increased in 37 (63%) of
the patients and fell in 22 (37%) patients from the initial to the second test.
The absolute magnitude of changes over time averaged 7 mm for EDD, 125 g for
mass, and 6 mL/kg per minute for peak Vo(2). Changes in LV size and mass per year
were significantly related to those in peak Vo(2) (r = -0.49 for EDD, r = -0.56
for ESD, and r = -0.44 for LV mass, respectively, all P <.001) and ventilatory
response to exercise (r = 0.60, r = 0.58, and r = 0.72 for EDD, ESD, and LV mass;
respectively, all P <.001). CONCLUSIONS: Changes over time in objective measures
of LV dimensions and mass, in patients with CHF are significantly related to
those in exercise capacity and respiratory efficiency.
PMID- 10783228
TI - Pericardial and pleural effusions in decompensated chronic heart failure.
AB - BACKGROUND: In decompensated chronic heart failure, there is controversy
regarding the incidence and amount of pericardial fluid. Moreover, the relation
of pericardial effusion to pleural effusion has not yet been clarified. The
current study examined the incidence and amount of pericardial effusion in
patients with decompensated chronic heart failure as a function of the volume of
pleural effusion. METHODS AND RESULTS: The study subjects were 60 consecutive
patients with chronic heart failure requiring diuresis to improve the symptoms
and signs of congestion. Pericardial effusion was semiquantified on the basis of
M-mode echocardiographic findings and the volume of thoracic effusion drawn from
computed tomographic images of the chest with Simpson's method. Causes of
decompensated chronic heart failure in the 60 patients included cardiac valve
disease (n = 26), arterial hypertension (n = 12), chronic ischemic heart disease
(n = 9), and others (n = 13). As many as 52 (87%) of the 60 patients had pleural
effusion; of these, 45 had bilateral effusion, 5 had right-sided effusion only,
and 2 had left-sided effusion only. In contrast, only 12 (20%) patients had small
(n = 9) or moderate (n = 3) pericardial effusion. There was no significant
association between the amount of pleural effusion and the semiquantified
pericardial effusion (chi-square 3.27, P =.775). CONCLUSIONS: In this series of
patients with congestive heart failure, small pericardial effusion was sometimes
observed, but moderate to large effusion was uncommon, and there was no
significant association between a given amount of pleural effusion and the volume
of pericardial effusion.
PMID- 10783229
TI - Effect of pregnancy on the duration of bovine pericardial bioprostheses.
PMID- 10783231
TI - Helicobacter pylori and chronic immune activation.
PMID- 10783235
TI - The molecular motor dynein is involved in targeting swallow and bicoid RNA to the
anterior pole of Drosophila oocytes.
AB - Localization of bicoid (bcd) messenger RNA to the anterior pole of the Drosophila
oocyte requires the exuperantia ( exu), swallow (swa) and staufen (stau) genes.
We show here that Swa protein transiently co-localizes with bcd RNA in mid
oogenesis. Swa also localizes to the anterior pole of the oocyte in the absence
of bcd RNA. This localization does not require Exu, but depends on intact
microtubules. In mutant ovaries with duplicated polarity of microtubules, Swa and
bcd RNA are ectopically localized at the posterior pole, as well as being present
at the anterior pole. We identify dynein light chain-1 (Ddlc-1), a component of
the minus-end-directed microtubule motor cytoplasmic dynein, as a Swa-binding
protein. We propose that Swa acts as an adaptor for the dynein complex and
thereby enables dynein to transport bcd RNA along microtubules to their minus
ends at the anterior pole of the oocyte.
PMID- 10783236
TI - Dynamics and segregation of cell-matrix adhesions in cultured fibroblasts.
AB - Here we use time-lapse microscopy to analyse cell-matrix adhesions in cells
expressing one of two different cytoskeletal proteins, paxillin or tensin, tagged
with green fluorescent protein (GFP). Use of GFP-paxillin to analyse focal
contacts and GFP-tensin to study fibrillar adhesions reveals that both types of
major adhesion are highly dynamic. Small focal contacts often translocate, by
extending centripetally and contracting peripherally, at a mean rate of 19
micrometers per hour. Fibrillar adhesions arise from the medial ends of
stationary focal contacts, contain alpha5beta1 integrin and tensin but not other
focal-contact components, and associate with fibronectin fibrils. Fibrillar
adhesions translocate centripetally at a mean rate of 18 micrometers per hour in
an actomyosin-dependent manner. We propose a dynamic model for the regulation of
cell-matrix adhesions and for transitions between focal contacts and fibrillar
adhesions, with the ability of the matrix to deform functioning as a mechanical
switch.
PMID- 10783237
TI - Real-time measurements of vesicle-SNARE recycling in synapses of the central
nervous system.
AB - Following the fusion of synaptic vesicles with the presynaptic plasma membrane of
nerve terminals by the process of exocytosis, synaptic-vesicle components are
recycled to replenish the vesicle pool. Here we use a pH-sensitive green
fluorescent protein to measure the residence time of VAMP, a vesicle-associated
SNARE protein important for membrane fusion, on the surfaces of synaptic
terminals of hippocampal neurons following exocytosis. The time course of VAMP
retrieval depends linearly on the amount of VAMP that is added to the plasma
membrane, with retrieval occurring between about 4 seconds and 90 seconds after
exocytosis, and newly internalized vesicles are rapidly acidified. These data are
well described by a model in which endocytosis appears to be saturable, but
proceeds with an initial maximum velocity of about one vesicle per second. We
also find that, following exocytosis, a portion of the newly inserted VAMP
appears on the surface of the axon.
PMID- 10783238
TI - Presenilin-1 differentially facilitates endoproteolysis of the beta-amyloid
precursor protein and Notch.
AB - Mutations in the presenilin-1 (PS1) gene are associated with Alzheimer's disease
and cause increased secretion of the neurotoxic amyloid-beta peptide (Abeta).
Critical intramembraneous aspartates at residues 257 and 385 are required for the
function of PS1 protein. Here we investigate the biological function of a
naturally occurring PS1 splice variant (PS1 Deltaexon 8), which lacks the
critical aspartate 257. Cell lines that stably express PS1 Deltaexon 8 or a PS1
protein in which aspartate residue 257 is mutated secrete significant levels of
Abeta, whereas Abeta generation is severely reduced in cells transfected with PS1
containing a mutation of aspartate 385. In contrast, endoproteolytic processing
of Notch is almost completely inhibited in cell lines expressing any of the PS1
variants that lack one of the critical aspartates. These data indicate that PS1
may differentially facilitate gamma-secretase-mediated generation of Abeta and
endoproteolysis of Notch.
PMID- 10783239
TI - A new ABC transporter mediating the detachment of lipid-modified proteins from
membranes.
AB - Lipoproteins in Escherichia coli are anchored to the periplasmic side of either
the inner or the outer membrane by a lipid moiety that is covalently attached to
the amino-terminal cysteine residue. Membrane specificity depends on a sorting
signal at position 2 of the lipoprotein. Lipoproteins directed to the outer
membrane are released from the inner membrane in an ATP-dependent manner through
the formation of a complex with LolA, a periplasmic chaperone. However, the
ATPase involved in this reaction has not been identified. Here we show, using
reconstituted proteoliposomes, that a new complex, LolCDE, belonging to the ATP
binding cassette (ABC) transporter family, catalyses the release of lipoproteins
in LolA- and sorting-signal-dependent manners. The LolCDE complex differs
mechanistically from all other ABC transporters as it is not involved in the
transmembrane transport of substrates. This new mechanism is evolutionarily
conserved in other gram-negative bacteria.
PMID- 10783240
TI - Noelin-1 is a secreted glycoprotein involved in generation of the neural crest.
AB - The vertebrate neural crest arises at the border of the neural plate during early
stages of nervous system development; however, little is known about the
molecular mechanisms underlying neural crest formation. Here we identify a
secreted protein, Noelin-1, which has the ability to prolong neural crest
production. Noelin-1 messenger RNA is expressed in a graded pattern in the
closing neural tube. It subsequently becomes restricted to the dorsal neural
folds and migrating neural crest. Over expression of Noelin-1 using recombinant
retroviruses causes an excess of neural crest emigration and extends the time
that the neural tube is competent to generate as well as regenerate neural crest
cells. These results support an important role for Noelin-1 in regulating the
production of neural crest cells by the neural tube.
PMID- 10783241
TI - A new self-assembled peroxisomal vesicle required for efficient resealing of the
plasma membrane.
AB - The Woronin body is a membrane-bound organelle that has been observed in over 50
species of filamentous fungi. However, neither the composition nor the precise
function of the Woronin body has yet been determined. Here we purify the Woronin
body from Neurospora crassa and isolate Hex1, a new protein containing a
consensus sequence known as peroxisome-targeting signal-1 (PTS1). We show that
Hex1 is localized to the matrix of the Woronin body by immunoelectron microscopy,
and that a green fluorescent protein- (GFP-)Hex1 fusion protein is targeted to
yeast peroxisomes in a PTS1- and peroxin-dependent manner. The expression of the
HEX1 gene in yeast generates hexagonal vesicles that are morphologically similar
to the native Woronin body, implying a Hex1-encoded mechanism of Woronin-body
assembly. Deletion of HEX1 in N. crassa eliminates Woronin bodies from the
cytoplasm and results in hyphae that exhibit a cytoplasmic-bleeding phenotype in
response to cell lysis. Our results show that the Woronin body represents a new
category of peroxisome with a function in the maintenance of cellular integrity.
PMID- 10783242
TI - Regulation of E2F transcription by cyclin E-Cdk2 kinase mediated through p300/CBP
co-activators.
AB - The E2F proteins form a family of transcription factors that regulate the
transition from the G1 to the S phase in the cell cycle. E2F activity is
regulated by members of the retinoblastoma protein (pRb) family, ensuring the
tight control of E2F-responsive genes. During the G1 phase, phosphorylation of
pRb by cyclin-dependent kinases (CDKs), most notably cyclin D-CDK complexes,
releases pRb from E2F, facilitating cell-cycle progression by the timely
induction of E2F-targeted genes such as cyclin E. However, it is not known
whether E2F proteins are directly targeted by CDKs. Here we show that E2F-5 is
phosphorylated by the cyclin E-Cdk2 complex, which functions in the late G1
phase, but not by the early-G1-phase-acting cyclin D-CDK complex. A
phosphorylation site in the trans-activation domain of E2F-5 stimulates
transcription and cell-cycle progression by the recruitment of the p300/CBP
family of co-activators, whose binding to E2F-5 is stabilized upon
phosphorylation by cyclin E-Cdk2. These results indicate that E2F activity may be
directly regulated by cyclin E-Cdk2, and imply an autoregulatory mechanism for
cell-cycle-dependent transcription through the CDK-stimulated interaction of E2F
with p300/CBP co-activators.
PMID- 10783244
TI - Detection of S-phase cells in tissue sections by in situ DNA replication.
PMID- 10783243
TI - TRAIL receptor-2 signals apoptosis through FADD and caspase-8.
PMID- 10783245
TI - Involvement of the Arp2/3 complex in phagocytosis mediated by FcgammaR or CR3.
PMID- 10783246
TI - Draining resources.
PMID- 10783247
TI - Drosophila genome takes flight.
AB - In the March 24 issue of Science, a flurry of papers report on the impending
completion of the Drosophila melanogaster genome sequence. This historic
achievement is the result of a unique collaboration between the Berkeley
Drosophila Genome Project (BDGP), led by Gerry Rubin, and the genomics company
Celera, headed by Craig Venter. With its genome almost completely sequenced ahead
of schedule, Drosophila is another important model organism to enter the
postgenomic age, and represents the largest genome sequenced to date.
PMID- 10783248
TI - mRNA export: the long and winding road.
AB - To the growing list of factors required for the export of messenger RNA from
nucleus to cytoplasm can now be added Yra1. Yeast Yra1 and its metazoan
orthologues bind mRNAs and interact with multiple mRNA export factors. Transport
of proteins and small RNAs does not require Yra1 or any other proteins required
for mRNA export, suggesting that mRNA export may proceed by a different
mechanism. The finding that Yra1 has a role in mRNA export moves us one step
closer to identifying all the proteins required for this process.
PMID- 10783249
TI - Matchmakers for sister-chromatid cohesion.
PMID- 10783250
TI - Teaching tumour suppressors new tricks.
AB - Examination of the tumour suppressor adenomatous polyposis coli (APC) has shown
that it may be multifunctional. Recent work has demonstrated dynamic interactions
of APC with the microtubule cytoskeleton, supporting the idea that APC has an
important function in cell migration.
PMID- 10783251
TI - Swallowing dynein: a missing link in RNA localization?
AB - Localization of bicoid messenger RNA to the anterior cortex of the developing
oocyte is essential for correct anterior-posterior patterning of the Drosophila
embryo. It now seems that the Swallow protein functions as an adaptor, bridging
bicoid mRNA to dynein, a molecular motor that would transport the complex
anteriorly along microtubules.
PMID- 10783252
TI - Unsheathing WASP's sting.
PMID- 10783253
TI - Control of apoptotic DNA degradation.
AB - Apoptotic DNA degradation has been thought to be a cell-autonomous process.
Recent evidence suggests that heterophagic recognition and engulfment of dying
cells by non-apoptotic cells may be critical for the activation and/or action of
apoptogenic DNases.
PMID- 10783254
TI - Rb function in cell-cycle regulation and apoptosis.
AB - Loss of cell-cycle control is a hallmark of neoplastic cells. One regulator of
the critical G1 to S-phase transition in the cell cycle is the retinoblastoma
tumour suppressor protein Rb, which interacts with the E2F family of cell-cycle
transcription factors to repress gene transcription required for this transition.
Through its interaction with E2F, Rb also regulates genes that control apoptosis.
Here we review the roles of Rb in regulating the cell cycle and apoptosis and
discuss recent results linking these Rb functions to chromatin-remodelling
enzymes.
PMID- 10783255
TI - Construction and characterization of a Schistosoma mansoni bacterial artificial
chromosome library.
AB - A bacterial artificial chromosome (BAC) library has been established from genomic
DNA isolated from the trematode parasite of human, Schistosoma mansoni. This
library consists of more than 21,000 recombinant clones carrying inserts in the
pBeloBAC11 vector. The mean insert size was 100 kb, representing an approximate
7.95-fold genome coverage. Library screening with eight chromosome-specific or
single-copy gene probes yielded between 1 and 9 positive clones, and none of
those tested was absent from the library. End sequences were obtained for 93
randomly selected clones, and 37 showed sequence identity to S. mansoni sequences
(ESTs, genes, or repetitive sequences). A preliminary analysis by fluorescence in
situ hybridization localized 8 clones on schistosome chromosomes 1 (2 clones), 2,
3, 5, Z, and W (3 clones). This library provides a new resource for the physical
mapping and sequencing of the genome of this important human pathogen.
PMID- 10783256
TI - Somatic versus germline mutation processes at minisatellite CEB1 (D2S90) in
humans and transgenic mice.
AB - The most variable human minisatellites show extreme germline instability
dominated by complex intra-allelic rearrangements plus a lower frequency of inter
allelic transfers of repeat units. In contrast, little is known about somatic
instability at such loci. We have therefore used single-molecule PCR to analyze
mutation at minisatellite CEB1 (D2S90) in human blood DNA. Somatic mutants were
rare and involved only relatively simple intra-allelic events, with no bias
toward expansions, in sharp contrast to the complex gain-biased rearrangements
seen in sperm. Somatic and germline mutation processes were further analyzed in
mice transgenic for a cosmid insert containing CEB1. Mutant molecules in
transgenic sperm and blood were detected but only at the low frequencies seen in
human blood and arose mainly by simple duplications and deletions as seen for
somatic mutations in human. These data suggest distinct pathways for germline and
somatic CEB1 mutations with germline instability involving recombination-based
repair of meiotic double-strand breaks and somatic mutation arising by
replication slippage or mitotic recombination. The problem of transferring
germline-specific features of minisatellite instability from human to mouse
suggests, with other recent observations, that long-range chromatin conformation
may be required for the recombination-based mode of germline instability at human
minisatellites.
PMID- 10783258
TI - Molecular cloning of a novel NF2/ERM/4.1 superfamily gene, ehm2, that is
expressed in high-metastatic K1735 murine melanoma cells.
AB - We have cloned a novel gene, Ehm2, that is expressed in high-metastatic but not
in low-metastatic K-1735 murine melanoma cells. The Ehm2 gene encodes a protein
of 527 amino acid residues, showing up to 41% amino acid identity with the FERM
domain of NF2/ERM/4.1 superfamily proteins, which have the function of connecting
cell surface transmembrane proteins to cytoskeletal molecules. The Ehm2 gene was
mapped to chromosome 4 and was expressed in the liver, lung, kidney, and testis
and in 7- to 17-day embryos. The highest level of homology was observed with
NBL4, which is a new subfamily protein of the NF2/ERM/4.1 superfamily. A human
homologue of the mouse Ehm2 gene, showing significant homology (83% identity),
was identified in the genomic DNA and EST databases. Furthermore, seven rat EST
clones and one pig EST clone in the GenBank EST database were identified as
having 83-92% sequence homology with the cDNA sequence of the mouse Ehm2 gene.
Thus, Ehm2 is a highly conserved gene that encodes a novel member of the
NF2/ERM/4.1 superfamily proteins.
PMID- 10783257
TI - Functional and genomic analysis of the human mitochondrial intermediate
peptidase, a putative protein partner of frataxin.
AB - We showed recently that the yeast mitochondrial intermediate peptidase (YMIP
polypeptide; gene symbol, OCT1) promotes mitochondrial iron uptake by catalyzing
the maturation of iron-utilizing proteins and exacerbates the mitochondrial iron
accumulation that results from loss of yeast frataxin, a mitochondrial protein
required for mitochondrial iron efflux. This suggests that the human MIP (HMIP
polypeptide; gene symbol MIPEP) may be one of the loci predicted to influence the
clinical manifestations of Friedreich's ataxia (FRDA), an autosomal recessive
neurodegenerative disease caused by lack of human frataxin. To begin to test this
hypothesis, we have characterized HMIP at the functional and genomic levels. We
show that HMIP can complement a yeast knock-out mutant lacking YMIP,
demonstrating that HMIP and YMIP are functional homologues. The MIPEP gene spans
57 kb and consists of 19 exons that correlate with the functional domains of
HMIP. Primer extension analysis has identified a major transcript of the MIPEP
gene expressed differentially and predominantly in tissues with high oxygen
consumption, while sequence analysis of approximately 2 kb of 5'-flanking DNA has
revealed putative Mt1/3/4, NF-kappaB, and AP-1 elements that may regulate MIPEP
expression in these tissues. Using a new polymorphic (CA)(n) repeat in intron 4,
MIPEP has been genetically mapped within a 7-cM interval between markers D13S283
and D13S217 on 13q12. This work provides the basis for molecular analysis of
MIPEP in FRDA and possibly other neurodegenerative diseases.
PMID- 10783259
TI - Sequence and expression pattern of a novel human orphan G-protein-coupled
receptor, GPRC5B, a family C receptor with a short amino-terminal domain.
AB - Query of GenBank with the amino acid sequence of human metabotropic glutamate
receptor subtype 2 (mGluR2) identified a predicted gene product of unknown
function on BAC clone CIT987SK-A-69G12 (located on chromosome band 16p12) as a
homologous protein. The transcript, entitled GPRC5B, was cloned from an expressed
sequence tag clone that contained the entire open reading frame of the transcript
encoding a protein of 395 amino acids. Analysis of the protein sequence reveal
that GPRC5B contains a signal peptide and seven transmembrane alpha-helices,
which is a hallmark of G-protein-coupled receptors (GPCRs). GPRC5B displays
homology to retinoic acid-inducible gene 1 (RAIG1, 33% sequence identity) and to
several family C (mGluR-like) GPCRs (20-25% sequence identity). Both RAIG1 and
GPRC5B have short extracellular amino-terminal domains (ATDs) that contrast the
very long ATDs characterizing the receptors currently assigned to family C.
However, our results strongly indicate that RAIG1 and GPRC5B form a new subgroup
of family C characterized by short ATDs. GPRC5B mRNA is widely expressed in
peripheral and central tissues with highest abundance in kidney, pancreas, and
testis. This mRNA expression pattern is markedly different from that of RAIG1,
which shows a slightly more restricted expression pattern with highest abundance
in lung tissue.
PMID- 10783260
TI - A sequence-ready physical map of the region containing the human natural killer
gene complex on chromosome 12p12.3-p13.2.
AB - We developed a sequence-ready physical map of a part of human chromosome 12p12.3
p13.2 where the natural killer gene complex (NKC) is located. The NKC includes a
cluster of genes with structure similar to that of the Ca(2+)-dependent lectin
superfamily of glycoproteins that are expressed on the surface of most natural
killer (NK) cells and a subset of T cells. These killer cell lectin-like
receptors (KLR) are involved in NK target cell recognition, leading to activation
or inhibition of NK cell function. We used a number of sequence-tagged site (STS)
markers from this region to screen two large insert bacterial artificial
chromosome (BAC) libraries and a bacteriophage P1-derived (PAC) chromosome
library. The clones were assembled into contiguous sets by STS content analysis.
The 72-BAC and 11-PAC contig covers nearly 2 Mb of DNA and provides an average
marker resolution of 26 kb. We have precisely localized 17 genes, 5 expressed
sequence tags, and 49 STSs within this contig. Of this total number of STS, 30
are newly developed by clone-end sequencing. We established the order of the
genes as tel-M6PR-MAFAL (HGMW-approved symbol KLRG1)-A2M-PZP-A2MP-NKRP1A (HGMW
approved symbol KLRB1)-CD69-AICL (HGMW-approved symbol CLECSF2)-KLRF1-OLR1-CD94
(HGMW-approved symbol KLRD1)-NKG2D (HGMW-approved symbol D12S2489E)-PGFL-NKG2F
(HGMW-approved symbol KLRC4)-NKG2E (HGMW-approved symbol KLRC3)-NKG2A (HGMW
approved symbol KLRC1)-LY49L (HGMW-approved symbol KLRA1)-cen. This map would
facilitate the cloning of new KLR genes and the complete sequencing of this
region.
PMID- 10783261
TI - Evidence for a Niemann-pick C (NPC) gene family: identification and
characterization of NPC1L1.
AB - Niemann-Pick type C1 (NPC1) disease is caused by defects in the NPC1 protein,
which result in perturbation of subcellular cholesterol transport. To identify
related proteins that may be involved in subcellular cholesterol trafficking, the
expressed sequence tag (EST) database was searched to find homologues of human
NPC1. A short, weakly similar EST was identified and used to obtain a full-length
human cDNA of about 5 kb and two alternatively spliced transcripts. The gene,
named NPC1L1, was mapped to chromosome 7p13, contained 20 exons, including an
unusually large 1526-bp exon 2, and spanned approximately 29 kb. In contrast to
NPC1, the NPC1L1 putative promoter region contained a sterol-regulatory element.
The predicted protein shared 42% identity and 51% similarity with NPC1.
Interestingly, NPC1L1 contains the conserved amino-terminal "NPC1 domain" and the
putative sterol-sensing domain, providing strong evidence that it is related to
human NPC1 and suggesting that these may comprise a new family of NPC1-related
proteins. However, the two differ with respect to their putative intracellular
targeting signals. Collectively, these data suggest that NPC1L1 and NPC1 form
part of a family of related proteins that may have similar functions at different
subcellular locations, perhaps at sequential steps of the same cholesterol
transport pathway.
PMID- 10783262
TI - Characterization of human retinal fascin gene (FSCN2) at 17q25: close physical
linkage of fascin and cytoplasmic actin genes.
AB - Retinal fascin is a newly identified photoreceptor-specific paralog of the actin
bundling protein fascin. Fascins crosslink f-actin into highly ordered bundles
within dynamic cell extensions such as neuronal growth cone filopodia. We have
isolated cDNA and genomic clones of human retinal fascin and characterized the
structure of the human retinal fascin gene (FSCN2). The cDNA predicts a protein
of 492 amino acids and molecular mass 55,057 that shows 94% identity to bovine
retinal fascin and 56% identity to human fascin. Promoter analysis reveals a
consensus retinoic acid response element and several potential binding sites for
transcription factors Crx and Nrl, which correlates with the retina-specific
expression of FSCN2 mRNA. Fluorescence in situ hybridization analysis and genomic
clone sequencing indicate that the FSCN2 gene lies within 200 kb of the actin
gene ACTG1 at 17q25. Database searches revealed that the human fascin gene FSCN1
and actin gene ACTB at 7p22 also coexist within a 200-kb genomic clone. The close
physical linkage of these fascin/actin gene pairs suggests that they derive from
a common gene duplication event and allows comparison of fascin and actin
phylogenetic analyses. Finally, a possible link to the retinitis pigmentosa 17
allele (RP17) at distal 17q was excluded by demonstration of multiple independent
segregation events in two RP17 kindreds. Informative FSCN2 polymorphisms were
identified and will serve as useful markers in future linkage studies. The likely
function of retinal fascin, in light of known fascin roles in other cell types,
is to assemble actin microfilaments in support of photoreceptor disk
morphogenesis.
PMID- 10783264
TI - Cloning and chromosomal mapping of human glucuronyltransferase involved in
biosynthesis of the HNK-1 carbohydrate epitope.
AB - The HNK-1 carbohydrate is expressed on various cell adhesion molecules in the
nervous system and is suggested to play a role in cell-cell and cell-substrate
interactions. Here we describe the isolation of a cDNA encoding human
glucuronyltransferase (GlcAT-P), which is a key enzyme in the biosynthesis of the
HNK-1 carbohydrate. The primary structure deduced from the cDNA sequence
predicted a type II transmembrane protein of 334 amino acids. Human GlcAT-P was
98.2% identical with rat GlcAT-P in amino acid sequence, the exception being the
length of the cytoplasmic tail. Northern blot analysis indicated that human GlcAT
P is expressed mainly in the brain. There is a single copy of the human GlcAT-P
gene (HGMW-approved symbol B3GAT1), and it was mapped to chromosome 11q25.
PMID- 10783263
TI - Human sulfotransferases SULT1C1 and SULT1C2: cDNA characterization, gene cloning,
and chromosomal localization.
AB - Sulfate conjugation catalyzed by sulfotransferase (SULT) enzymes is an important
pathway in the biotransformation of many drugs, other xenobiotics,
neurotransmitters, and hormones. We previously described a human cDNA, SULT1C1,
that encoded a protein similar in sequence to that of rat ST1C1. Subsequently, a
related human cDNA, SULT1C2, was reported. In the present study, we set out to
characterize further the human SULT1C1 cDNA and then to clone, structurally
characterize, and map its gene. As an initial step, we performed 5'- and 3'-RACE
with SULT1C1 cDNA. Those experiments demonstrated that a small number of SULT1C1
transcripts contained an "insert," which we later showed resulted from
alternative splicing that involved an Alu sequence in intron 3 of SULT1C1. We
then cloned and structurally characterized the SULT1C1 gene from a human genomic
BAC library. Because the sequence of SULT1C2 was closely related to that of
SULT1C1 and because the genes for other human SULT paralogues occur in clusters,
we screened the BAC clones that had been positive for SULT1C1 to search for
SULT1C2 and discovered a clone that contained both genes. That BAC was used to
sequence and structurally characterize SULT1C2. SULT1C1 and SULT1C2 were
approximately 21 and 10 kb in length, respectively. Both genes contained seven
exons that encoded protein, and both had structures that were similar to those of
other genes that encode members of the SULT1 family. Finally, human SULT1C1 and
SULT1C2 mapped to 2q11.2 by fluorescence in situ hybridization. The cloning and
structural characterization of SULT1C1 and SULT1C2 will now make it possible to
perform molecular genetic and pharmacogenomic studies of these sulfate
conjugating enzymes in humans.
PMID- 10783266
TI - The expanded human kallikrein gene family: locus characterization and molecular
cloning of a new member, KLK-L3 (KLK9).
AB - In rodents, kallikreins are encoded by a large multigene family but in humans,
only three kallikrein genes were thought to exist. Based on the homology between
the human and the rodent kallikrein loci, we defined a 300-kb human kallikrein
gene region on chromosome 19q13. 3-q13.4. By using linear sequence information,
restriction analysis, PCR, and blotting techniques, we were able to construct the
first detailed map of the human kallikrein gene locus. Comparative analysis of
genes located in this area enabled us to expand the human kallikrein multigene
family with some recently identified serine proteases and establish common
structural features. We further identified a new kallikrein-like gene, named
kallikrein-like gene 3 (KLK-L3; HGMW-approved symbol KLK9). We describe the
structural characterization of the KLK-L3 gene, together with its precise
chromosomal localization in relation to other kallikreins and its tissue
expression pattern and hormonal regulation.
PMID- 10783265
TI - Identification of a testis-specific gene (C15orf2) in the Prader-Willi syndrome
region on chromosome 15.
AB - Prader-Willi syndrome (PWS) results from the loss of paternal contributions for a
2-Mb imprinted region on the proximal long arm of human chromosome 15. Hitherto,
five paternally active genes have been identified in this region (ZNF127, NDN,
MAGEL2, SNURF-SNRPN, and IPW). Here we report the identification of a novel gene
in the PWS critical region, which has been designated "chromosome 15 open reading
frame 2" (C15orf2). C15orf2 is an intronless gene located between MAGEL2 and
SNURF-SNRPN. It is associated with a CpG island, which is methylated in all
tissues tested except for germ cells. C15orf2 is transcribed as a 7.5-kb mRNA and
contains an open reading frame encoding a predicted 1156-amino-acid protein of
unknown function. Transcription of C15orf2 occurs exclusively in the testis, and
in adult testis samples, we observed biallelic expression. By zoo-blot analysis,
we found related sequences in DNA from other primates, but not in nonprimate DNA.
We conclude that C15orf2 may play a role in primate spermatogenesis.
PMID- 10783267
TI - Design of a high-power NMR probe for low-temperature studies.
AB - A low-temperature, high-power NMR probe head design is described which eliminates
the problem of electric arc discharge commonly experienced during radiofrequency
pulse cycling in a helium environment. A polychlorotrifluoroethylene (Kel-F) coil
former, fitted with a solenoid coil, is heat-shrunk onto stainless-steel flanges
and spot-welded inside a stainless-steel probe head assembly connected to a
hollow coaxial transmission-line probe shaft. By this means, the sample coil and
all high-voltage elements can effectively be isolated in a vacuum, while at the
same time permitting good thermal contact between the sample and cryogenic gas.
This design was used in NMR studies in the 4.6 K < or = T < or = 77 K temperature
range for RF pulse durations < or = 50 ms (and longer for low RF amplitudes) and
amplitudes up to approximately 60 G.
PMID- 10783268
TI - t(1) noise and sensitivity in pulsed field gradient experiments.
AB - In this paper, a calculation routine based on product operator formalism and
coherence pathway is presented, which describes t(1) noise and sensitivity in
pulsed field gradient experiments. Several examples including the absolute value
mode pulsed field gradient COSY, MQF-COSY, MQC, HMQC, and NOESY sequences are
investigated to study the t(1) noise stemming from the phase errors of
radiofrequency (RF) pulses and the sensitivity affected by RF pulse rotation
angles. Our theoretical results indicate that the t(1) noises in P-type COSY,
multiple-quantum-filtered (MQF)-COSY, and multiple-quantum coherence (MQC) are
lower than those in the N-type corresponding experiments, while in HMQC and NOESY
there is no difference in t(1) noise effects between P-type and N-type spectra.
Meanwhile, from the calculations, we obtained the optimized RF pulse rotation
angles in those sequences. In MQF-COSY, an increase in sensitivity of about
4(cos(2)θ sin(q-1)2θ)(2) - 1 (θ = arc cot can be achieved by
using the optimized angles. In MQC, the increase is 2 cos(2)θ sin(q
1)2θ - 1 (θ = arc cot. MQF-COSY experiments are also carried out to
support our corresponding theoretical results.
PMID- 10783269
TI - (1)H-(17)O nuclear-quadrupole double-resonance study of hydrogen disorder in 2
nitrobenzoic acid.
AB - Temperature dependence of (17)O nuclear quadrupole resonance frequencies was
measured in solid 2-nitrobenzoic acid by a (1)H-(17)O nuclear quadrupole double
resonance technique. The experimental results show the presence of a fast
exchange of hydrogen atoms between two nonequivalent positions within the O-H
ellipsis O hydrogen bonds. The hydrogen disorder is ascribed to concerted jumps
of two hydrogen atoms within the hydrogen bonds connecting two molecules in a
dimer. The energy difference DeltaE of the two hydrogen configurations is equal
to DeltaE = 60 meV = 5.8 kJ/mol. The dipole structure of the (17)O NQR lines from
the C-O-H oxygen positions was also measured at -100 degrees C and at room
temperature. The orientation of the principal axes of the electric field gradient
tensor with respect to the O-H bond and the sign of the quadrupole coupling
constant were determined. The oxygen-hydrogen distance R(O-H), as determined from
the dipole structure of the (17)O NQR lines is at -100 degrees C equal to 0.099
nm. At room temperature we observe a longer distance, R(O-H) = 0.101 nm, in
agreement with the hydrogen intrabond exchange.
PMID- 10783270
TI - Jones matrix formalism for quasioptical EPR.
AB - The Jones matrix formalism that has been used to analyze quasioptical millimeter
wave circuits is extended for specific application to high-frequency electron
paramagnetic resonance (EPR). A survey of general expressions for Jones matrices
of elements commonly used in quasioptical EPR spectrometers is given. The Jones
matrix representations of quasioptical transmission and reflection cavities are
derived, and their relationship to the equivalent circuit and transmission line
representations used for conventional EPR cavities is demonstrated. The formalism
is applied to selected quasioptical EPR spectrometer designs and experimental
tests of the formalism are presented for two configurations of a quasioptical
spectrometer operating at 220 GHz.
PMID- 10783271
TI - Automatic correction for phase shifts, frequency shifts, and lineshape
distortions across a series of single resonance lines in large spectral data
sets.
AB - A new model-free method is presented that automatically corrects for phase
shifts, frequency shifts, and additional lineshape distortions of one single
resonance peak across a series of in vivo NMR spectra. All separate phase and
frequency variations are quickly and directly derived from the common lineshape
in the data set using principal component analysis and linear regression. First,
the new approach is evaluated on simulated data in order to quantitatively assess
the phase and frequency shifts which can be removed by the proposed correction
procedure. Subsequently, the value of the method is demonstrated on in vivo (31)P
NMR spectra from skeletal muscle of the hind leg of the mouse focusing on the
phosphocreatine resonance which is distorted by the experimental procedure. Phase
shifts, frequency shifts, and lineshape distortions with respect to the common
lineshape in the spectral data set could successfully be removed.
PMID- 10783272
TI - Two-pulse nutation echoes generated by gradients of the radiofrequency amplitude
and of the main magnetic field.
AB - A two-pulse NMR nutation spectroscopy scheme is suggested that leads to a new
type of spin echoes. The amplitude of the radiofrequency (RF) pulses as well as
the external magnetic field are assumed to be subject to gradients G(1) and G(0),
respectively, in the same but otherwise arbitrary direction. Multiple echoes are
predicted and observed at times k(G(1)/G(0))tau(1) and tau -/+ k(G(1)/G(0))tau(1)
(k = 1, 2, 3, ...) after the second RF pulse, where tau(1) represents the
radiofrequency pulse duration, and tau is the spacing of the RF pulses. Based on
these echoes, a method for diffusion measurements is proposed that simultaneously
provides the spin-lattice relaxation time and the self-diffusion coefficient.
PMID- 10783273
TI - Remote tuning of NMR probe circuits.
AB - There are many circumstances in which the probe tuning adjustments cannot be
located near the rf NMR coil. These may occur in high-temperature NMR, low
temperature NMR, and in the use of magnets with small diameter access bores. We
address here circuitry for connecting a fixed-tuned probe circuit by a
transmission line to a remotely located tuning network. In particular, the
bandwidth over which the probe may be remotely tuned while keeping the losses in
the transmission line acceptably low is considered. The results show that for all
resonant circuit geometries (series, parallel, series-parallel), overcoupling of
the line to the tuned circuit is key to obtaining a large tuning bandwidth. At
equivalent extents of overcoupling, all resonant circuit geometries have nearly
equal remote tuning bandwidths. Particularly for the case of low-loss
transmission line, the tuning bandwidth can be many times the tuned circuit's
bandwidth, f(o)/Q.
PMID- 10783274
TI - Multiple quantum and high-resolution NMR, molecular structure, and order
parameters of partially oriented ortho and meta dimethyl-, dichloro-, and
chloromethylbenzenes codissolved in nematic liquid crystals.
AB - We develop a strategy for analyzing complex nuclear magnetic resonance (NMR)
spectra of several solutes codissolved in liquid-crystal phases. Spectral
parameters of solutes m- or o-xylene were estimated by analyzing 2D multiple
quantum NMR spectra using a modified version of a least-squares fitting routine
which adjusts chemical shifts, order parameters, structural parameters, and/or
dipolar couplings independently. These estimates were used to facilitate analysis
of the high-resolution spectra which contain resonances from many solutes.
Calculated spectra of m- or o-xylene were subtracted from the experimental high
resolution spectra leaving resonances from the other solutes readily visible.
Accurate spectral parameters of all codissolved solutes were determined from the
high-resolution spectra. Order parameters and structural parameters (including
vibrationally corrected parameters) of m- and o-xylene, m- and o-chlorotoluene,
and m- and o-dichlorobenzene were calculated from the dipolar couplings.
PMID- 10783275
TI - Electron nuclear quadruple resonance for assignment of overlapping spectra.
AB - Multiple resonance methods are important tools in EPR for revealing the network
of hyperfine levels of free radicals and paramagnetic centers. The variations of
electron nuclear double resonance (ENDOR) or electron spin-echo envelope
modulation (ESEEM) techniques help to correlate nuclear frequencies with each
other. These methods have limited utility when there is extensive overlap or
suspected overlap in the EPR spectrum between different species or different
orientations. In the ENDOR spectrum, overlap and second-order shifts of lines
also leads to ambiguity in assignment and interpretation. A new electron nuclear
multiple resonance method is presented here that is based on population transfer
ENDOR. It is a quadruple resonance method that correlates ENDOR lines and reveals
the network of hyperfine levels in samples with unoriented paramagnetic species
and in samples with overlapping EPR or ENDOR lines.
PMID- 10783276
TI - An L-band crossed-loop (Bimodal) EPR resonator.
AB - Our crossed-loop resonator design has been enhanced to increase the filling
factor and has been extended from S-band to L-band. High isolation between the
two modes results in shorter dead time in pulsed EPR experiments than would occur
with a reflection resonator of the same Q.
PMID- 10783277
TI - Off-resonance effects of the radiofrequency pulses used in spectral editing with
double-quantum coherence transfer.
AB - Spectral editing using gradient selected double-quantum (DQ) coherence transfer
is often used for the selective observation of metabolites in vivo. In attempting
to optimize the detection sensitivity of a conventional DQ spectral editing
sequence, the effects of using radiofrequency (RF) pulses that are not at the
resonance frequency of the observed peaks were investigated both theoretically
and experimentally. The results show that spectral editing using pulses at the
frequency of the observed resonance does not necessarily give the optimal
detection sensitivity. At 7 T, the detection sensitivity of lactate observed
using a DQ editing method can be increased by up to 30% by setting the RF pulses
off resonance at the proper frequency. The results also suggest that slice
selective RF pulses used in DQ spectral editing combined with PRESS localization
may have slice profiles different from those when the same pulses are used for
standard PRESS spatial localization.
PMID- 10783278
TI - Correlation time and diffusion coefficient imaging: application to a granular
flow system.
AB - A parametric method for spatially resolved measurements for velocity
autocorrelation functions, R(u)(tau) = , expressed as a sum of
exponentials, is presented. The method is applied to a granular flow system of 2
mm oil-filled spheres rotated in a half-filled horizontal cylinder, which is an
Ornstein-Uhlenbeck process with velocity autocorrelation function R(u)(tau) =
e(- ||tau ||/tau(c)), where tau(c) is the correlation time and D =
tau(c) is the diffusion coefficient. The pulsed-field-gradient NMR method
consists of applying three different gradient pulse sequences of varying motion
sensitivity to distinguish the range of correlation times present for particle
motion. Time-dependent apparent diffusion coefficients are measured for these
three sequences and tau(c) and D are then calculated from the apparent diffusion
coefficient images. For the cylinder rotation rate of 2.3 rad/s, the axial
diffusion coefficient at the top center of the free surface was 5.5 x 10(-6)
m(2)/s, the correlation time was 3 ms, and the velocity fluctuation or granular
temperature was 1.8 x 10(-3) m(2)/s(2). This method is also applicable to
study transport in systems involving turbulence and porous media flows.
PMID- 10783279
TI - Relaxation effects on transverse magnetization using RF pulses long compared to
T(2).
AB - The transverse relaxation effects which occur during the application of optimized
slice-selective Shinnar-Le Roux pulses are studied. The behavior of both
longitudinal and transverse magnetization is examined, focusing the attention on
changes which affect the absorption and dispersion components. Besides the
reduction in amplitude, the absorption component was found to be unaffected by
transverse relaxation times, whereas the dispersion component was strongly
distorted. A comparison between the distortion components from pulses having same
length but different bandwidths is given.
PMID- 10783280
TI - Electron spin-lattice relaxation rates for high-spin Fe(III) complexes in glassy
solvents at temperatures between 6 and 298 K.
AB - The temperature dependence of spin-lattice relaxation rates was analyzed for four
high-spin nonheme iron proteins between 5 and 20 K, for three high-spin iron
porphyrins between 5 and 118 K, and for four high-spin heme proteins between 5
and 150 to 298 K. For the nonheme proteins the zero-field splittings, D, are less
than 0.7 cm(-1), and the relaxation is dominated by the Orbach and Raman
processes. For the iron porphyrins and heme proteins D is between 4 and 12 cm(-1)
and the relaxation is dominated by the Orbach process between about 5 and 100 K
and by a local mode at higher temperatures. The relaxation rates for the heme
proteins in glassy matrices extrapolated to values at room temperature that are
similar to values obtained by NMR relaxivity in fluid solution. This similarity
suggests that for high-spin Fe(III) heme proteins with effective intramolecular
spin-lattice relaxation processes, the additional motional freedom gained when a
relatively large protein goes from glassy solid to liquid solution at room
temperature has little impact on spin-lattice relaxation.
PMID- 10783281
TI - Clean TROSY: compensation for relaxation-induced artifacts.
AB - TROSY pulse sequences for recording, e.g., (1)H-(15)N chemical shift correlation
spectra of proteins are designed to select only one of four two-dimensional
multiplet components. However, all of the variants published so far are prone to
relaxation-induced artifacts at the positions of two of the other multiplet
components. This article introduces modifications to the two spin-state-selective
coherence transfer building blocks of the TROSY mixing sequence resulting in a
clean TROSY spectrum with the artifacts largely suppressed. It works by having
the new mixing sequence generate peaks of opposite phase at the positions of the
relaxation artifacts. The clean TROSY pulse sequence is marginally shorter than
the original one and contains the same pulses. Experimental demonstration is
presented for the (15)N-labeled proteins RAP 17-97 (N-terminal domain of alpha(2)
macroglobulin receptor associated protein) and EQT, equinatoxin II, from the
Mediterranean anemone Actinia equina.
PMID- 10783282
TI - 1H NMR relaxation investigation of inhibitors interacting with Torpedo
californica acetylcholinesterase.
AB - Two naphthyridines interacting with Torpedo californica acetylcholinesterase
(AChE) were investigated. (1)H NMR spectra were recorded and nonselective,
selective, and double-selective spin-lattice relaxation rates were measured. The
enhancement of selective relaxation rates could be titrated by different ligand
concentrations at constant AChE (yielding 0.22 and 1.53 mM for the dissociation
constants) and was providing evidence of a diverse mode of interaction. The
double-selective relaxation rates were used to evaluate the motional correlation
times of bound ligands at 34.9 and 36.5 ns at 300 K. Selective relaxation rates
of bound inhibitors could be interpreted also in terms of dipole-dipole
interactions with protons in the enzyme active site.
PMID- 10783283
TI - High-frequency dynamic nuclear polarization in the nuclear rotating frame.
AB - A proton dynamic nuclear polarization (DNP) NMR signal enhancement (epsilon)
close to thermal equilibrium, epsilon = 0.89, has been obtained at high field
(B(0) = 5 T, nu(epr) = 139.5 GHz) using 15 mM trityl radical in a 40:60
water/glycerol frozen solution at 11 K. The electron-nuclear polarization
transfer is performed in the nuclear rotating frame with microwave irradiation
during a nuclear spin-lock pulse. The growth of the signal enhancement is
governed by the rotating frame nuclear spin-lattice relaxation time (T(1rho)),
which is four orders of magnitude shorter than the nuclear spin-lattice
relaxation time (T(1n)). Due to the rapid polarization transfer in the nuclear
rotating frame the experiment can be recycled at a rate of 1/T(1rho) and is not
limited by the much slower lab frame nuclear spin-lattice relaxation rate
(1/T(1n)). The increased repetition rate allowed in the nuclear rotating frame
provides an effective enhancement per unit time(1/2) of epsilon(t) = 197. The
nuclear rotating frame-DNP experiment does not require high microwave power;
significant signal enhancements were obtained with a low-power (20 mW) Gunn diode
microwave source and no microwave resonant structure. The symmetric trityl
radical used as the polarization source is water-soluble and has a narrow EPR
linewidth of 10 G at 139.5 GHz making it an ideal polarization source for high
field DNP/NMR studies of biological systems.
PMID- 10783284
TI - Combining PGSE NMR with homonuclear dipolar decoupling.
AB - A new robust approach for combining multiple-pulse homonuclear decoupling and
PGSE NMR is introduced for accurately measuring molecular diffusion coefficients
in systems with nonvanishing static homonuclear dipolar couplings. Homonuclear
decoupling suppresses dipolar dephasing during the gradient pulses but its
efficiency and scaling factor for the effective gradient vary across the sample
because of the large variation of the frequency offset caused by the gradient.
The resulting artifacts are reduced by introducing a slice selection scheme. The
method is demonstrated by (19)F PGSE NMR experiments in a lyotropic liquid
crystal.
PMID- 10783285
TI - A solid-state NMR index of helical membrane protein structure and topology.
AB - The secondary structure and topology of membrane proteins can be described by
inspection of two-dimensional (1)H-(15)N dipolar coupling/(15)N chemical shift
polarization inversion spin exchange at the magic angle spectra obtained from
uniformly (15)N-labeled samples in oriented bilayers. The characteristic wheel
like patterns of resonances observed in these spectra reflect helical wheel
projections of residues in both transmembrane and in-plane helices and hence
provide direct indices of the secondary structure and topology of membrane
proteins in phospholipid bilayers. We refer to these patterns as PISA (polarity
index slant angle) wheels. The transmembrane helix of the M2 peptide
corresponding to the pore-lining segment of the acetylcholine receptor and the
membrane surface helix of the antibiotic peptide magainin are used as examples.
PMID- 10783286
TI - Three-dimensional solid-state NMR spectroscopy is essential for resolution of
resonances from in-plane residues in uniformly (15)N-labeled helical membrane
proteins in oriented lipid bilayers.
AB - Uniformly (15)N-labeled samples of membrane proteins with helices aligned
parallel to the membrane surface give two-dimensional PISEMA spectra that are
highly overlapped due to limited dispersions of (1)H-(15)N dipolar coupling and
(15)N chemical shift frequencies. However, resolution is greatly improved in
three-dimensional (1)H chemical shift/(1)H-(15)N dipolar coupling/(15)N chemical
shift correlation spectra. The 23-residue antibiotic peptide magainin and a 54
residue polypeptide corresponding to the cytoplasmic domain of the HIV-1
accessory protein Vpu are used as examples. Both polypeptides consist almost
entirely of alpha-helices, with their axes aligned parallel to the membrane
surface. The measurement of three orientationally dependent frequencies for Val17
of magainin enabled the three-dimensional orientation of this helical peptide to
be determined in the lipid bilayer.
PMID- 10783287
TI - Imaging membrane protein helical wheels.
AB - Resonance patterns have been observed in 2D solid-state NMR spectra of the
transmembrane segment of M2 protein from Influenza A virus in oriented samples
reflecting the helical wheel of this alpha-helix. The center of this pattern
uniquely defines the helical tilt with respect to the bilayer normal without a
need for resonance assignments. The distribution of resonances from amino acid
specific labels around the "PISA wheel" defines the rotational orientation of the
helix and yields preliminary site-specific assignments. With assignments high
resolution structural detail, such as differences in tilt and rotational
orientation along the helical axis leading to an assessment of helical coiling,
can be obtained.
PMID- 10783288
TI - Time-shared X(omega(1))-half-filter for improved sensitivity in subspectral
editing.
AB - Experiments with X-half-filter elements allow the separation of the resonances
from protons bound and unbound to a spin X into different subspectra. This
Communication presents a modified half-filter element where the filter delay is
simultaneously used for chemical shift labeling and scalar coupling evolution in
a semi-constant time experiment. The filter element is demonstrated with a (1)H
NOESY spectrum of a 28.5-kDa 2:1 complex between the uniformly (13)C-labeled N
terminal domain of Escherichia coli arginine repressor and operator DNA.
PMID- 10783289
TI - Suppression of diagonal peaks in three-dimensional protein NMR TROSY-type HCCH
correlation experiments.
AB - A novel method for suppression of (13)C-(13)C diagonal peaks without sensitivity
loss in three-dimensional HCCH TROSY-type NMR correlation experiments involving
aromatic side chains in proteins (Pervushin et al., J. Am. Chem. Soc. 120, 6394
6400 (1998)) is presented. The key element is a spin-state-selective filter in
the (13)C-(13)C mixing sequence with the dual effect of selecting the TROSY
resonance in the preceding evolution period and interchanging TROSY and anti
TROSY resonances. The cross peaks are invariant to this filter but diagonal peak
coherence gets concentrated on the anti-TROSY transition so that it can be
eliminated by a (13)C --> (1)H TROSY transfer element. The new method is
demonstrated using a (13)C,(15)N-labeled protein sample, RAP 18-112 (N-terminal
domain of alpha(2)-macroglobulin receptor associated protein), at 750 MHz.
PMID- 10783290
TI - An iterative fitting procedure for the determination of longitudinal NMR cross
correlation rates.
AB - We present a method to measure (15)N-(1)H dipolar/(15)N CSA longitudinal cross
correlation rates in protonated proteins. The method depends on the measurement
of four observables: the cumulative proton-proton cross relaxation rates, the
(15)N R(1) relaxation rate, the multiexponential decay of 2N(Z)H(N)(Z) spin
order, and multiexponential buildup of 2N(Z)H(N)(Z) spin-order. The (15)N-(1)H
dipolar/(15)N CSA longitudinal cross-correlation rate is extracted from these
measurements by an iterative fitting procedure to the solution of differential
equations describing the coupled relaxation dynamics of the z-magnetization of
the (15)N nucleus, the two-spin-order 2N(Z)H(N)(Z), and a two-spin-order term
2N(Z)H(Q)(Z) describing the interaction with remote protons. The method is
applied to the microbial ribonuclease binase. The method can also extract
longitudinal cross-correlation rates for those amide protons that are involved in
rapid solvent exchange. The experiment that serves for extracting proton-proton
cross-relaxation rates is a modification of 3D (15)N-resolved NOESY-HSQC. The
experiment restores the solvent magnetization to its equilibrium state during
data detection for all phase cycling steps and all values of NOE mixing times and
is recommended for use in standard applications as well.
PMID- 10783291
TI - The future of genetic analysis of neurological disorders.
AB - Molecular genetic analysis has allowed the elucidation of the etiology of many
single-gene, neurodegenerative syndromes. However, as yet, it has had little
direct impact on our understanding of the etiology in cases with more complex
modes of inheritance. With the completion of the sequence of the human genome, it
should be possible to start to attack these more complex problems. In this
article, we review the genetic methods that may be used to dissect the etiologies
of these diseases and outline what types of clinical samples will be needed for
this quest.
PMID- 10783292
TI - Neuroanatomical abnormalities in behaviorally characterized APP(V717F) transgenic
mice.
AB - Histological analyses were performed on the brains of APP(V717F) transgenic
(Tg)mice previously studied in a battery of behavioral tests. We describe here
the regional and age-dependent deposition of amyloid in both heterozygous and
homozygous Tg mice. We also report that Tg mice show significant and age
dependent changes in synaptic density measured by synaptophysin immunoreactivity.
Surprisingly, a rather marked hippocampal atrophy is observed as early as 3
months of age in Tg mice (20-40%). Statistical analyses revealed that the
deficits in object recognition memory are related to the number of amyloid
deposits in specific brain regions, whereas deficits in spatial reference and
working memory are related to the changes in synaptic density and hippocampal
atrophy. Our study suggests that the behavioral deficits observed in Tg mice are
only in part related to amyloid deposition, but are also related to
neuroanatomical alterations secondary to overexpression of the APP(V717F)
transgene and independent of amyloid deposition.
PMID- 10783294
TI - Subcellular localization of presenilins: association with a unique membrane pool
in cultured cells.
AB - We have investigated the subcellular distribution of presenilin-1 (PS1) and
presenilin-2 (PS2) in a variety of mammalian cell lines. In Iodixanol-based
density gradients, PS1 derivatives show a biphasic distribution, cofractionating
with membranes containing ER-resident proteins and an additional population of
membranes with low buoyant density that do not contain markers of the Golgi
complex, ERGIC, COP II vesicles, ER exit compartment, COP II receptor, Golgi
SNARE, trans-Golgi network, caveolar membranes, or endocytic vesicles. Confocal
immunofluorescence and immunoelectron microscopy studies fully supported the
fractionation studies. These data suggest that PS1 fragments accumulate in a
unique subcompartment(s) of the ER or ER to Golgi trafficking intermediates.
Interestingly, the FAD-linked PS1 variants show a marked redistribution toward
the heavier region of the gradient. Finally, and in contrast to PS1, PS2
fragments are detected preponderantly in more densely sedimenting membranes,
suggesting that the subcellular compartments in which these molecules accumulate
are distinct.
PMID- 10783293
TI - Characterization of pathology in transgenic mice over-expressing human genomic
and cDNA tau transgenes.
AB - To examine the normal cellular function of tau and its role in pathogenesis, we
have created transgenic mice that overexpress a tau transgene derived from a
human PAC that contains the coding sequence, intronic regions, and regulatory
regions of the human gene. All six isoforms of human tau are represented in the
transgenic mouse brain at the mRNA and protein level and the human tau is
distributed in neurites and at synapses, but is absent from cell bodies. A
comparison between the genomic tau mice and mice that overexpress a tau cDNA
transgene shows that overall, the distribution of tau is similar in the two
lines, but human tau is located in the somatodendritic compartment of many
neurons in the cDNA mice. Tau-immunoreactive axonal swellings were found in the
spinal cords of the cDNA mice, which correlated with a hind-limb abnormality,
whereas neuropathology was essentially normal in the genomic mice up to 8 months
of age.
PMID- 10783295
TI - Functional phenotype in transgenic mice expressing mutant human presenilin-1.
AB - Mutations in the presenilin-1 (PS1) gene cause approximately 50% of cases of
early onset familial Alzheimer's disease. The function of this protein remains
unknown. We have made an electrophysiological study of hippocampal slices from
transgenic mice expressing either a normal human PS1 transgene (WT) or one of two
human PS1 transgenes bearing pathogenic mutations at codon M146 (M146L and
M146V). Medium and late afterhyperpolarizations in CA3 pyramidal cells were
larger in mice expressing either mutant form compared with WT and nontransgenic
controls. Calcium responses to depolarization were larger in M146L mice compared
with nontransgenic littermates; synaptic potentiation of the CA3 to CA1
projection was also stronger. These results demonstrate disruption of the control
of intracellular calcium and electrophysiological dysfunction in PS1 mutant mice.
PMID- 10783296
TI - EBV-based plasmid DNA rearrangements after transfection of eukaryotic cells.
AB - The cDNA encoding influenza virus (A/Udorn/307/72 strain) M2 protein was
subcloned into the EBV-based vector pREP9. Three continuous kidney cellular lines
of different origin were transfected with recombinant plasmid pREP9-M2. One and 5
months after transfection plasmid DNA rearrangements were detected by means of
restriction analysis of recovered plasmids and their hybridization with an
influenza-virus-specific radioactive probe. Deletions were the most frequent type
of pREP9-M2 mutations. PCR with primers corresponding to cellular genome and
plasmid DNA followed by Southern blot analysis with the [(32)P]-labeled M2
fragment allowed host DNA rearrangements to be revealed in transfected cells.
PMID- 10783297
TI - Expression of bacillar glutamyl endopeptidase genes in Bacillus subtilis by a new
mobilizable single-replicon vector pLF.
AB - The pLF1311 natural plasmid from Lactobacillus fermentum 1311 was used to
construct a single-replicon vector suitable for rapid cloning in a wide range of
gram-positive hosts and Escherichia coli. The new vector is capable of
conjugative mobilization from E. coli to various hosts by conjugal transfer. The
final vector (3.4 kb) showed a high segregational and structural stability and a
high copy number. Glutamyl endopeptidase genes from Bacillus licheniformis
(gseBL) and B. intermedius (gseBI) were cloned in both pLF9 and pLF14 vectors and
introduced to B. subtilis. The yield of enzymes in the pLF-derived producers was
6- to 30-fold more than in the natural producers and reached 100-150 mg/L of
mature protease.
PMID- 10783298
TI - Plasmid R1 is present as clusters in the cells of Escherichia coli.
AB - Fluorescence microscopy was used to determine the location(s) of the replication
origin of plasmid R1 in exponentially growing cells of Escherichia coli. The
number of oriR1 foci per cell was smaller than the number of R1 copies per cell
and was found to be the same for a copA mutant of R1 and for the wild-type
plasmid. The intensities of individual foci were stronger for the cop mutant than
for the wild type. We interpreted these results to imply that the plasmid DNA
molecules were localized in small groups/clusters, a result that seems contrary
to the earlier observations that plasmid R1 replicates randomly and segregates as
a single-copy unit. The implications for the quantitative behavior of plasmid R1
in stability, incompatibility tests, replication, and partition experiments are
discussed.
PMID- 10783299
TI - Construction of a tightly regulated plasmid vector for Streptococcus pneumoniae:
controlled expression of the green fluorescent protein.
AB - We have constructed a regulated plasmid vector for Streptococcus pneumoniae,
based on the streptococcal broad-host-range replicon pLS1. As a reporter gene, we
subcloned the gfp gene from Aequorea victoria, encoding the green fluorescent
protein. This gene was placed under the control of the inducible P(M) promoter of
the S. pneumoniae malMP operon which, in turn, is regulated by the product of the
pneumococcal malR gene. Binding of MalR protein to the P(M) promoter is
inactivated by growing the cells in maltose-containing media. Highly regulated
gene expression was achieved by cloning in the same plasmid the P(M)-gfp cassette
and the malR gene, thus providing the MalR regulator in cis. Pneumococcal cells
harboring this vector gave a linear response of GFP synthesis in a maltose
dependent mode without detectable background levels in the absence of the
inducer.
PMID- 10783300
TI - Identification of a potential membrane-targeting region of the replication
initiator protein (TrfA) of broad-host-range plasmid RK2.
AB - Plasmid RK2 codes for two species of the replication initiator protein TrfA (33
and 44 kDa). Both polypeptides are strongly associated with membrane fractions of
Escherichia coli host cells (W. Firshein and P. Kim, Mol. Microbiol. 23, 1-10,
1997). We investigated the role of a 12-amino-acid hydrophobic region (HR) in the
membrane association of TrfA. Epitope-tagged polypeptide fragments of TrfA that
contained HR were expressed and found to be associated with membrane fractions.
Site-directed mutagenesis of trfA revealed that changes of specific amino acids
in HR can affect both TrfA association with the membrane and its ability to
support replication of an RK2 oriV plasmid in vivo. These results are consistent
with the hypothesis that membrane association of TrfA is functionally relevant
and that the HR region of TrfA is involved in membrane association and DNA
replication in vivo.
PMID- 10783301
TI - Cloning and characterization of the replicon of the Nocardia italica plasmid,
pNI100.
AB - A 19-kb plasmid, pNI100, was isolated from Nocardia italica CCRC12359; its
replicon was cloned and characterized as having a single open reading frame (ORF)
of 1188 bp specifying 396 amino acids (aa). Analyses of the deduced aa sequence
of the Rep protein indicated that characteristics of three consensus sequences
and a P-loop-like motif in the Rep protein of plasmid pSG5, a conjugative plasmid
involving a rolling-circle replication mechanism, were conserved in those of
plasmid pNI100. Phenotypically, a pock structure was produced in the regenerated
mycelium by introducing pNI100 DNA into the Streptomyces lividans protoplast.
This result strongly suggests that pNI100 is a conjugative plasmid and probably
replicates by a rolling-circle replication mechanism. By using the replicon of
pNI100, a bifunctional plasmid pNI105 that could replicate in both Escherichia
coli and S. lividans was constructed and found to be a useful cloning shuttle
vector.
PMID- 10783302
TI - Identification and characterization of a native Dichelobacter nodosus plasmid,
pDN1.
AB - The gram-negative anaerobe Dichelobacter nodosus is the primary causative agent
of ovine footrot, a mixed bacterial infection of the hoof. We report here the
characterization of a novel native plasmid, pDN1, from D. nodosus. Sequence
analysis has revealed that pDN1 has a high degree of similarity to broad-host
range plasmids belonging, or related, to Escherichia coli incompatibility group
Q. However, in contrast to these plasmids, pDN1 encodes no antibiotic resistance
determinants, lacks genes E and F, and hence is smaller than all previously
reported IncQ plasmids. In addition, pDN1 belongs to a different incompatibility
group than the IncQ plasmids to which it is related. However, pDN1 does contain
the replication and mobilization genes that are responsible for the extremely
broad host range characteristic of IncQ plasmids, and derivatives of pDN1
replicate in E. coli. In addition, the mobilization determinants of pDN1 are
functional, since derivatives of pDN1 are mobilized by the IncPalpha plasmid RP4
in E. coli.
PMID- 10783303
TI - Analysis of the complete nucleotide sequence of the tetracycline-resistance
transposon Tn10.
AB - An analysis of the complete nucleotide sequence of the composite tetracycline
resistance transposon Tn10 (9147 bp) from the Salmonella typhi conjugative
plasmid R27 is presented. A comparison of the protein sequences from IS10-right
and IS10-left transposases has identified four amino acid differences. These
residues appear to play an important role in normal transposase function and may
account for the differences in exhibited transposition activities. The
tetracycline determinants encoded by this version of Tn10 share >99% identity
with those of Tn10(R100), demonstrating the conservation that exists between
these transposons. A previously uncharacterized approximately 3000-bp region of
Tn10 contains four putative open reading frames. One of these open reading frames
shares 55% identity with the glutamate permease protein sequence from Haemophilus
influenzae although it was unable to complement an Escherichia coli glutamate
permease mutant, with which it shares 51% identity. The three remaining putative
open reading frames are arranged as a discrete genetic unit adjacent to the
glutamate permease homolog and are transcribed in the opposite direction. Two of
these open reading frames are homologous with Bacillus subtilis proteins of
unknown functions while the other has no homologs in the database. The presence
of an aminoacyl-tRNA synthetase class II motif in one of these open reading
frames in combination with the glutamate permease homolog allows us to postulate
that this region of Tn10 could once have played a role in amino acid metabolism.
PMID- 10783304
TI - Disorders in cell circuitry during multistage carcinogenesis: the role of
homeostasis.
AB - The multistage process of carcinogenesis involves the progressive acquisition of
mutations, and epigenetic abnormalities in the expression, of multiple genes that
have highly diverse functions. An important group of these genes are involved in
cell cycle control. Thus, cyclin D1 is frequently overexpressed in a varety of
human cancers. Cylin D1 plays a critical role in carcinogenesis because (i)
overexpression enhances cell transformation and tumorigenesis, and enhances the
amplification of other genes, and (ii) an antisense cyclin D1 cDNA reverts the
malignant phenotype of carcinoma cells. Therefore, cyclin D1 may be a useful
biomarker in molecular epidemiology studies, and inhibitors of its function may
be useful in both cancer chemoprevention and therapy. We discovered a paradoxical
increase in the cell cycle inhibitors protein p27(Kip1) in a subset of human
cancers, and obtained evidence for homeostatic feedback loops between cyclins D1
or E and p27(Kip1). Furthermore, derivatives of HT29 colon cancer cells with
increased levels of p27(Kip1) showed increased sensitivity to induction of
differentiation. This may explain why decreased p27(Kip1) in a subset of human
cancers is associated with a high grade (poorly differentiated) histology and
poor prognosis. Agents that increase cellular levels of p27(Kip1) may, therefore,
also be useful in cancer therapy. Using an antisense Rb oligonucleotide we
obtained evidence that the paradoxical increase in pRb often seen in human colon
cancers protects these cells from growth inhibition and apopotosis. On the basis
of these, and other findings, we hypothesize that homeostatic feedback mechanisms
play a critical role in multistage carcinogenesis. Furthermore, because of their
bizarre circuitry, cancer cells suffer from 'gene addiction' and 'gene
hypersensitivity' disorders that might be exploited in both cancer prevention and
chemotherapy.
PMID- 10783305
TI - The INK4a/ARF locus in murine tumorigenesis.
AB - The INK4a/ARF locus is regarded as one of the most important anti-tumoral
defenses that mammalian organisms possess. The characterization of its two gene
products, p16(INK4a) and p19(ARF), has provided a great insight on the
functioning of the tumor suppressors Rb and p53, respectively. Present evidence
indicates that the INK4a/ARF locus is transcriptionally activated by oncogenic
stresses, resulting in cell-cycle arrest or apoptosis. Here, I review the
evidence accumulated on the involvement of the INK4a/ARF locus in murine
tumorigenesis. Also, I summarize the phenotype of the different transgenic mouse
models based on the inactivation of the INK4a/ARF locus.
PMID- 10783306
TI - Activation of NF-kappaB/Rel occurs early during neoplastic transformation of
mammary cells.
AB - NF-kappaB/Rel is a family of transcription factors which are expressed in all
cells; however, in most non-B cells, they are sequestered in the cytoplasm in
inactive complexes with specific inhibitory proteins, termed IkappaBs. We have
recently shown that NF-kappaB/Rel factors are aberrantly activated in human
breast cancer and rodent mammary tumors, and function to promote tumor cell
survival and proliferation. Here, we have examined the time-course of induction
of NF-kappaB/Rel factors upon carcinogen treatment of female Sprague-Dawley (S-D)
rats in vivo and in human mammary epithelial cells (HMECs) in culture. We
observed that NF-kappaB/Rel activation is an early event, occurring prior to
malignant transformation. In S-D rats, increased NF-kappaB/Rel binding was
detected in nuclear extracts of mammary glands from 40% of animals 3 weeks post
treatment with 15 mg/kg 7,12-dimethylbenz[a]anthracene (DMBA); this is prior to
formation of tumors which normally begin to be detected after 7-9 weeks. In non
tumorigenic MCF-10F cells, in vitro malignant transformation upon treatment with
either DMBA or benzo[a]pyrene (B[a]P) resulted in a 4- to 12-fold increase in
activity of classical NF-kappaB (p65/p50). NF-kappaB induction was corrrelated
with a decrease in the stability of the NF-kappaB-specific inhibitory protein
IkappaB-alpha. Ectopic expression of the transactivating p65 subunit of NF-kappaB
in MCF-10F cells induced the c-myc oncogene promoter, which is driven by two NF
kappaB elements, and endogenous c-Myc levels. Furthermore, reduction mammoplasty
derived HMECs, immortalized following B[a]P exposure, showed dysregulated
induction of classical NF-kappaB prior to malignant transformation. Together
these findings suggest that activation of NF-kappaB plays an early, critical role
in the carcinogen-driven transformation of mammary glands.
PMID- 10783307
TI - 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) inhibits growth factor withdrawal
induced apoptosis in the human mammary epithelial cell line, MCF-10A.
AB - Previous studies have demonstrated that 2,3,7, 8-tetrachlorodibenzo-p-dioxin
(TCDD) increases cell recovery in the human mammary epithelial cell line MCF-10A
grown under growth factor-restricted conditions. TCDD was also found to mimic
growth factor signaling pathways by stimulating the tyrosine phosphorylation of
numerous effector molecules, and increased phosphatidylinositol 3-kinase (PI3K)
activity in the absence of exogenously added growth factors. In the present
studies, we have expanded on these initial results to show that TCDD (3-30 nM)
increases cell recovery on days 2-6 by as much as 80% when insulin or epidermal
growth factor (EGF) was removed from the media. The mechanism for this effect
appears to be complex as TCDD inhibited apoptosis stimulated by EGF, or EGF and
insulin, withdrawal by almost 80% as determined by Annexin V binding. However,
withdrawal of insulin alone did not induce apoptosis even though TCDD did
increase cell number in its absence. These results were corroborated by
immunoblot analysis of poly(ADP-ribose) polymerase cleavage. Since TCDD
stimulates PI3K activity, the phosphorylation status of Akt, a serine/threonine
kinase that mediates PI3K-dependent inhibition of apoptosis, was examined.
Immunoblot analysis revealed that TCDD causes a transient increase in the
phosphorylated form of Akt that peaks at 6 h and disappears by 12 h. It appears
that EGF stimulates an anti-apoptotic pathway, while insulin signals a pro
mitogenic pathway. By stimulating or mimicking one or both of these pathways TCDD
may alter tightly regulated growth pathways in the MCF-10A cell line.
PMID- 10783308
TI - Effect of a tyrosine 155 to phenylalanine mutation of protein kinase cdelta on
the proliferative and tumorigenic properties of NIH 3T3 fibroblasts.
AB - Tyrosine phosphorylation has emerged as an important mechanism in the regulation
of enzyme function. In this paper, we describe a mutant of PKCdelta altered at a
single tyrosine residue which has the opposite effect compared with wild-type
PKCdelta on the growth characteristics of NIH 3T3 cells. Overexpression of wild
type PKCdelta results in a decreased growth rate and a lower cell density at
confluency. On the other hand, overexpression of PKCdelta with a mutation from
tyrosine to phenylalanine at position 155 results in a significantly higher rate
of growth and a higher density at confluency compared with vector controls.
Moreover, these cells are able to grow in soft agar and to form tumors in nude
mice. In contrast to kinase negative PKC constructs, this mutant maintains in
vitro kinase activity and shows a subcellular localization and a translocation
pattern that are similar to those of the wild-type PKCdelta. Whether the altered
biological effect is due to the missing phosphorylation on tyrosine or the
mutation from tyrosine to phenylalanine per se remains under investigation.
PMID- 10783309
TI - Cell activation via CD44 occurs in advanced stages of squamous cell
carcinogenesis.
AB - Squamous cell carcinoma (SCC) derives from dysplastic or metaplastic stratified
epithelia. The process of squamous cell carcinogenesis has been investigated for
the potential role of the adhesion molecule CD44, whose standard form (CD44s) and
isoforms generated by alternative splicing of variant exons are known to display
altered expression during tumorigenesis in other systems. We have utilized an in
vitro correlate of squamous cell carcinogenesis, in which progression stages from
normal squamous epithelium to dysplastic lesions and to SCC are represented by
primary cultures of normal keratinocytes, by human papilloma virus-immortalized
keratinocytes (UP) and by HPVimmortalized/v-Ha-ras transfected tumorigenic
keratinocytes (UPR). We investigated expression of CD44 and of variant isoforms,
from mRNA to intracellular and surface protein levels, and found no relationship
between expression of CD44 and stages of squamous cell carcinogenesis. However,
when the function of CD44 was analyzed as Ca(2+) mobilization ability upon
monoclonal antibody binding and crosslinking, signal transduction via CD44 was
found only for the neoplastic stage (UPR cells). Ca(2+) mobilization was
completely independent of density of surface CD44. We have performed similar
analyses in an in vitro model of SCC in which four squamous tumor cell lines and
UPR cells were sorted according to increasing resistance to external cytotoxic
stimuli, i.e. starving conditions, treatment with the retinoid N-(4
hydroxyphenyl)retinamide and cytolytic activity of effector lymphokine-activated
killer cells. No relationship between expression of CD44 and level of cell
resistance against external cell death-inducing stimuli was found, while CD44
mediated Ca(2+) mobilization ability was restricted to the highly resistant tumor
cell lines. Our results indicate that the role(s) of CD44 in squamous cell
proliferative disorders can be evinced from the functional features of the
molecule, rather than from its phenotypic repertoire.
PMID- 10783310
TI - Influence of DNA structure on hypoxanthine and 1,N(6)-ethenoadenine removal by
murine 3-methyladenine DNA glycosylase.
AB - 3-Methyladenine DNA glycosylases initiate base excision repair by flipping the
nucleotide bearing the target base out of double-stranded DNA into an active site
pocket for glycosylic bond cleavage and base release. Substrate bases for the
murine 3-methyladenine DNA glycosylase (other than 3-methyladenine) include
hypoxanthine and 1,N(6)-ethenoadenine, two mutagenic adducts formed by both
endogenous and exogenous agents. Using double-stranded DNA oligonucleotides
containing damaged bases at specific sites, we studied the relative removal rates
for these two adducts when located in different sequence contexts. One of the
sequence contexts was an A:T tract, chosen because DNA secondary structure is
known to change along the length of this tract, due to a progressive narrowing of
the minor groove. Here we report that removal rates for hypoxanthine, but not for
1,N(6)-ethenoadenine, are dramatically affected by its location within the A:T
tract. In addition, the removal rates of hypoxanthine and 1,N(6)-ethenoadenine
when paired opposite thymine or cytosine were examined, and in each sequence
context hypoxanthine removal decreased by at least 20-fold when paired opposite
cytosine versus thymine. In contrast, 1, N(6)-ethenoadenine removal was
unaffected by the identity of the opposing pyrimidine. We conclude that the
removal of certain bases by the mouse 3-methyladenine DNA glycosylase can be
modulated by both adjacent and opposing sequence contexts. The influence of DNA
sequence context upon DNA repair rates, such as those described here, may
contribute to the creation of mutational hot spots in mammalian cells.
PMID- 10783311
TI - Dietary antioxidant depletion: enhancement of tumor apoptosis and inhibition of
brain tumor growth in transgenic mice.
AB - Apoptosis, or regulated cell suicide, eliminates unwanted and damaged cells,
including precancerous and cancerous cells. Since reactive oxygen species (ROS)
act as essential apoptotic mediators, we reasoned that increasing the ROS level
might enhance apoptosis and thereby slow down tumor growth. Here, using a defined
transgenic brain tumor model with known tumor apoptosis rates, we test the impact
of antioxidant-depleted diet, capable of increasing ROS levels, or antioxidant
enriched diets on tumor growth. Dramatically increased apoptosis occurs within
tumors, but not in normal tissues of antioxidant-depleted mice. The presence of
detectable increased oxidant stress within tumors indicates that the likely
mechanism of enhanced tumor apoptosis is via ROS and DNA oxidative impairment.
Importantly, due to the ROS-enhanced apoptosis, tumor growth is inhibited in mice
fed an antioxidant-depleted diet. In clear contrast, an antioxidant-rich diet had
no impact on tumor growth.
PMID- 10783312
TI - (-)-Epigallocatechin gallate can prevent cisplatin-induced lung tumorigenesis in
A/J mice.
AB - Risks of secondary lung cancer in patients with non-small cell lung cancer and
small cell lung cancer are estimated to be 1-2% and 2-10% per patient per year,
respectively. Cisplatin is widely used in the treatment of lung cancer and is
also known as a carcinogen in experimental animals. In this study, the effect of
(-)-epigallocatechin gallate (EGCG) on cisplatin-induced lung tumors in A/J mice
was investigated. Female A/J mice (4 weeks old) were divided into four groups:
group 1, control without treatment; group 2, EGCG treatment (1 mg/ml in tap
water); group 3, weekly cisplatin treatment (1.62 mg/kg body wt, i.p.) for 10
weeks; group 4, cisplatin plus EGCG treatment (EGCG was started 2 weeks before
cisplatin treatment). Four groups of mice were killed at week 30 after treatment.
Tumor incidence was 26.3% (5/19) in group 1, 30% (6/20) in group 2, 100% (19/19)
in group 3 and 94.4% (17/18) in group 4. Tumor multiplicity (the number of tumors
per mouse, mean +/- SD) was 0.4 +/- 0.8 in group 1, 0.4 +/- 0.8 in group 2, 5.1
+/- 2.1 in group 3 and 2.8 +/- 2.3 in group 4. Tumor multiplicity was
significantly reduced by adding EGCG to cisplatin-treated mice (P < 0.01).
Furthermore, EGCG significantly reduced cisplatin-induced weight loss from 24.7
26.3% (cisplatin treatment) to 10.8-11.6% (cisplatin plus EGCG treatment) (P <
0.01). These findings suggest that EGCG can inhibit cisplatin-induced weight loss
and lung tumorigenesis in A/J mice.
PMID- 10783313
TI - Plant phenolics decrease intestinal tumors in an animal model of familial
adenomatous polyposis.
AB - Epidemiological studies consistently indicate that consumption of fruits and
vegetables lowers cancer risk in humans and suggest that certain dietary
constituents may be effective in preventing colon cancer. Plant-derived phenolic
compounds manifest many beneficial effects and can potentially inhibit several
stages of carcinogenesis in vivo. In this study, we investigated the efficacy of
several plant-derived phenolics, including caffeic acid phenethyl ester (CAPE),
curcumin, quercetin and rutin, for the prevention of tumors in C57BL/6J-Min/+
(Min/+) mice. These animals bear a germline mutation in the Apc gene and
spontaneously develop numerous intestinal adenomas by 15 weeks of age. At a
dietary level of 0.15%, CAPE decreased tumor formation in Min/+ mice by 63%.
Curcumin induced a similar tumor inhibition. Quercetin and rutin, however, both
failed to alter tumor formation at dietary levels of 2%. Examination of
intestinal tissue from the treated animals showed that tumor prevention by CAPE
and curcumin was associated with increased enterocyte apoptosis and
proliferation. CAPE and curcumin also decreased expression of the oncoprotein
beta-catenin in the enterocytes of the Min/+ mouse, an observation previously
associated with an antitumor effect. These data place the plant phenolics CAPE
and curcumin among a growing list of anti-inflammatory agents that suppress Apc
associated intestinal carcinogenesis.
PMID- 10783314
TI - Effect of intact and isoflavone-depleted soy protein on NMU-induced rat mammary
tumorigenesis.
AB - Experiments in animal models of carcinogenesis suggest that soy consumption
decreases tumor number and incidence. Genistein, an isoflavone which is present
in soy at high concentrations, has been considered to be the primary antitumor
constituent in soy. In the present study, the N-nitroso-N-methylurea (NMU)
induced mammary tumor model was used as a means to determine whether the
chemopreventive effect of soy was attributable specifically to its high content
of isoflavones. Five groups of rats (30/group) were fed the following modified
AIN-93G diets: group 1, 20% intact soy protein (SP); group 2, 10% SP; group 3,
20% isoflavone-depleted soy protein (IDSP); group 4, 10% IDSP; group 5, the
casein-based AIN-93G diet. The SP contained 1.07 and IDSP 0.073 mg genistein/g
isolate, respectively. Experimental diets were initiated 1 week prior to NMU
administration (at 50 days of age) and continued for another 18 weeks. No
significant differences were found among the five groups when assessed in terms
of tumor incidence, latency, multiplicity or volume. A trend towards inhibition
was observed in both the 20 and 10% SP and IDSP groups when assessed in terms of
total tumors/group, tumor volume and latency, but this trend did not achieve
statistical significance. The results of this model study do not support the
hypothesis that the isoflavone components of soy protein, or soy protein itself,
inhibit chemically induced mammary tumor development.
PMID- 10783315
TI - Inhibitory effects of Bifidobacterium-fermented soy milk on 2-amino-1-methyl-6
phenylimidazo[4,5-b]pyridine-induced rat mammary carcinogenesis, with a partial
contribution of its component isoflavones.
AB - High consumption of soybean and soybean-related products is hypothesized to
contribute to protection against breast cancer. Soybean is a rich source of
genistein, a putative cancer chemopreventive agent. Fermented soy milk (FSM),
which is made of soy milk fermented with the Bifidobacterium breve strain Yakult,
contains larger amounts of the isoflavone aglycones genistein and daidzein than
unfermented soy milk. In the present study, we examined the effects of FSM and
its component isoflavone mixture (genistein:daidzein 4:1) on 2-amino-1-methyl-6
phenylimidazo[4, 5-b]pyridine (PhIP)-induced mammary carcinogenesis in rats.
Starting at 7 weeks of age, female Sprague-Dawley rats were given PhIP at a dose
of 85 mg/kg body wt by intragastric administration four times a week for 2 weeks.
They were fed control high fat basal diet or experimental high fat diet
containing 10% FSM or 0.02 or 0.04% isoflavone mixture during and after
carcinogen exposure. The incidences (percentage of rats with tumors) of mammary
gland tumors were 71% in the control diet group, 51% in the FSM group and 68 and
61% in the groups treated with isoflavone mixture at 0.02 and 0.04%,
respectively. Mammary tumor multiplicities (number of tumors per rat) were 1.2 +/
0.2 for 10% FSM, 2.2 +/- 0.4 for 0.02% isoflavone mixture and 1.5 +/- 0.3 for
0.04% isoflavone mixture, being clearly smaller than the control diet value (2.6
+/- 0.5). Furthermore, feeding of FSM and the isoflavone mixture at both doses
reduced the sizes of mammary tumors. Since the amounts of isoflavones in 10% FSM
are approximately equivalent to those in the 0.02% isoflavone mixture, the
chemopreventive activity of FSM could be partly attributable to the presence of
isoflavones such as genistein and daidzein.
PMID- 10783316
TI - Antiproliferative and apoptotic effects of O-Trensox, a new synthetic iron
chelator, on differentiated human hepatoma cell lines.
AB - We investigated the effects of a new iron chelator, O-Trensox (TRX), compared
with desferrioxamine (DFO), on proliferation and apoptosis in cultures of the
human hepatoblastoma HepG2 and hepatocarcinoma HBG cell lines. Our results show
that TRX decreased DNA synthesis in a time- and dose-dependent manner and with a
higher efficiency than DFO. Mitotic index was also strongly decreased by TRX and,
unexpectedly, DFO inhibited mitotic activity to the same extent as TRX, thus
there is a discrepancy between the slight reduction in DNA synthesis and a large
decrease in mitotic index after DFO treatment. In addition, we found that TRX
induced accumulation of cells in the G(1) and G(2) phases of the cell cycle
whereas DFO arrested cells in G(1) and during progression through S phase. These
data suggest that the partial inhibition of DNA replication observed after
exposure to DFO may be due to a lower efficiency of metal chelation and/or that
it does not inhibit the G(1)/S transition but arrests cells in late S phase. The
effects of both TRX and DFO on DNA synthesis and mitotic index were reversible
after removing the chelators from the culture medium. An apoptotic effect of TRX
was strongly suggested by analysis of DNA content by flow cytometry, nuclear
fragmentation and DNA degradation in oligonucleosomes and confirmed by the
induction of a high level of caspase 3-like activity. TRX induced apoptosis in a
dose- and time-dependent manner in proliferating HepG2 cells. In HBG cells, TRX
induced apoptosis in proliferating and confluent cells arrested in the G(1) phase
of the cell cycle, demonstrating that inhibition of proliferation and induction
of apoptosis occurred independently. DFO induced DNA alterations only at
concentrations >100 microM and without induction of caspase 3-like activity,
indicating that DFO is not a strong inducer of apoptosis. Addition of Fe or Zn to
the culture medium during TRX treatment led to a complete restoration of
proliferation rate and inhibition of apoptosis, demonstrating that Fe/Zn
saturated TRX was not toxic in the absence of metal depletion. These data show
that TRX, at concentrations of 20-50 microM, strongly inhibits cell proliferation
and induces apoptosis in proliferating and non-proliferating HepG2 and HBG cells,
respectively.
PMID- 10783317
TI - Suppression of polypogenesis in a new mouse strain with a truncated Apc(Delta474)
by a novel COX-2 inhibitor, JTE-522.
AB - Mutations of the adenomatous polyposis coli gene (Apc) have been implicated in
the occurrence of sporadic colon cancer. Various Apc knockout strains of mice
have been created to better understand the function of this gene. In the present
study, using gene targeting, we disrupted the mouse Apc gene at the end of exon
10 to compare its effect with the effects of other types of Apc gene disruption,
all of which are on exon 15. The mice expressed a mutant form of mRNA that
encoded 474 amino acids instead of 2845 amino acids due to exon duplication. In
addition, these Apc(Delta474) knockout mice developed intestinal and mammary
tumors. Since the most severe cases of familial adenomatous polyposis are
associated with mutations on exon 15, our mutation at exon 10 was expected to
result in a mild phenotype. However, the number of polyps that our mice developed
was similar to that of other Apc knockout mice such as Apc(Min) and Apc(1309)
mice. Cyclooxygenase-2 (COX-2) has been implicated in colorectal carcinoma.
Apc(Delta474) mice treated with JTE-522, a novel COX-2-selective inhibitor,
showed a significantly reduced number of polyps. These results suggest that COX-2
plays an important role in polypogenesis and COX-2-selective inhibitors can be
used as new preventive therapeutics against colorectal tumors.
PMID- 10783318
TI - Suppression of cyclooxygenase-2 promoter-dependent transcriptional activity in
colon cancer cells by chemopreventive agents with a resorcin-type structure.
AB - Cyclooxygenase-2 (COX-2) is abundantly expressed in colon cancer cells. It has
been reported that inhibition of COX-2 enzyme activity is shown to prevent colon
carcinogenesis. Thus, suppression of COX-2 expression may also be an effective
chemopreventive strategy. In the present study, we constructed a beta
galactosidase reporter gene system in human colon cancer DLD-1 cells, and
measured COX-2 promoter-dependent transcriptional activity in the cells.
Interferon gamma suppressed this COX-2 promoter activity, while 12-O
tetradecanoylphorbol-13-acetate and transforming growth factor alpha (TGFalpha)
exerted enhancing effects. We then tested the influence of 14 candidate cancer
chemopreventive compounds on COX-2 promoter activity. Chemopreventive agents such
as quercetin, kaempferol, genistein, resveratrol and resorcinol, all having a
common resorcin moiety, were found to effectively suppress the COX-2 promoter
activity with and without TGFalpha-stimulation in DLD-1 cells. Since all these
compounds have a resorcin moiety as a common structure, a resorcin-type structure
may play an active role in the inhibition of COX-2 expression in colon cancer
cells.
PMID- 10783319
TI - Polymorphisms in the DNA repair genes XRCC1 and ERCC2 and biomarkers of DNA
damage in human blood mononuclear cells.
AB - Polymorphisms in several DNA repair genes have recently been identified, but
little is known about their phenotypic significance. To determine whether
variation in DNA repair genes is related to host DNA damage, we studied the
association between polymorphisms in XRCC1 (codon 399) and ERCC2 (codon 751) and
two markers of DNA damage, sister chromatid exchange (SCE) frequencies (n = 76)
and polyphenol DNA adducts (n = 61). SCE frequencies were determined using a
modified fluorescence-Giemsa method and polyphenol DNA adducts were determined
using a P1-enhanced (32)P-post-labeling procedure. XRCC1 and ERCC2 genotypes were
identified using PCR-RFLP. Mean SCE frequencies among current smokers who were
homozygous carriers of the 399Gln allele in XRCC1 were greater than those in
399Arg/Arg current smokers. We also observed a possible gene-dosage effect for
XRCC1 399Gln and detectable DNA adducts, and significantly more adducts among
older subjects who were carriers of the 399Gln allele than in younger subjects
with the 399Arg/Arg genotype. The polymorphism in ERCC2 was unrelated to SCE
frequency or DNA adduct level. Our results suggest that carriers of the
polymorphic XRCC1 399Gln allele may be at greater risk for tobacco- and age
related DNA damage.
PMID- 10783320
TI - The COX-2 inhibitor nimesulide suppresses superoxide and 8-hydroxy-deoxyguanosine
formation, and stimulates apoptosis in mucosa during early colonic inflammation
in rats.
AB - As we have shown previously [Tardieu,D., Jaeg,J.P., Cadet,J., Embvani,E.,
Corpet,D.E. and Petit,C. (1998) Cancer Lett, 134, 1-5], a 48-h treatment of 6%
dextran sodium sulphate (DSS) in drinking water led to a reproducible 2-fold
increase of the mutagenic oxidative lesion 8-oxo-7,8-dihydro-2'-deoxyguanosine (8
oxodGuo) in colonic mucosa DNA of rats in vivo. The aim of this study was to test
the effect of nimesulide, a preferential COX-2 inhibitor, on the DSS-induced 8
oxodGuo increase. We show that nimesulide when administered orally,
simultaneously with DSS at 5 mg/kg/day, not only totally prevents 8-oxodGuo
formation but also suppresses the 5-fold increase of superoxide induced by DSS in
the colonic mucosa. This was measured by in vivo formazan blue precipitation (P <
0.01 in the Wilcoxon test). Moreover, nimesulide enhances apoptosis by
approximately 30% as compared with the already high level induced by DSS
treatment (P < 0.01). It is suggested that the significant increase in mutagenic
oxidative DNA damage, produced by mild acute colonic inflammation, could be
important in the initiation of colon cancer in both animals and man. These
effects may explain at least partly the well-documented protective action towards
colon cancer by preferential COX-2 inhibitors, either xenobiotics such as
nimesulide or natural nutrients.
PMID- 10783321
TI - Chemoprevention of tobacco-smoke lung carcinogenesis in mice after cessation of
smoke exposure.
AB - Male strain A/J mice were exposed for 6 h per day, 5 days per week to a mixture
of 89% cigarette sidestream smoke and 11% mainstream smoke. Total suspended
particulate concentrations were 137 mg/m(3). In experiment 1, animals were
exposed for 5 months to tobacco smoke and given a 4 month recovery period in air.
Lung tumor multiplicity was 2.4 and incidence 89%. Animals exposed to filtered
air had 1.0 tumor per lung (65% incidence). In animals kept for 5 months in
smoke, removed into air and then fed a diet containing a mixture of myoinositol
and dexamethasone, tumor multiplicity was 1.0 and incidence was 62%. These values
were significantly (P < 0.01) lower than in animals exposed to smoke and
identical to values seen in controls. In animals fed a diet containing 250 mg/kg
each of phenethyl isothiocyanate and benzyl isothiocyanate during the entire 9
months, lung tumor multiplicity was 2.1 and incidence 96%, not significantly
different from animals exposed to smoke and fed control diet. In experiment 2,
animals were exposed for 5 months to smoke, followed by a 4 month recovery period
in air and were fed during the entire period a diet containing either D-limonene
or 1, 4-phenylenebis(methylene)selenoisocyanate (p-XSC). In animals exposed to
tobacco smoke and fed control diet, lung tumor multiplicity was 2.8, whereas in
the animals fed D-limonene it was 2. 6 and in the animals fed p-XSC it was 2.4.
The differences to the controls were statistically not significant. It was
concluded that myoinositol-dexamethasone successfully prevents the development of
tobacco smoke-induced lung tumors even if administered when the animals have
'quit' smoking. On the other hand, agents otherwise shown to prevent lung tumor
formation following administration of 4-(methylnitrosamino)-1-(3-pyridyl)-1
butanone or benzo[a]pyrene were ineffective against tobacco smoke.
PMID- 10783322
TI - Dietary choline restriction causes complex I dysfunction and increased H(2)O(2)
generation in liver mitochondria.
AB - Removal of choline from the diet results in accumulation of triglycerides in the
liver, and chronic dietary deficiency produces a non-genotoxic model of
hepatocellular carcinoma. An early event in choline deficiency is the appearance
of oxidized lipid, DNA and protein, suggesting that increased oxidative stress
may facilitate neoplasia in the choline deficient liver. In this study, we find
that mitochondria isolated from rats fed a choline-deficient, L-amino acid
defined diet (CDAA) demonstrate impaired respiratory function, particularly in
regard to complex I-linked (NADH-dependent) respiration. This impairment in
mitochondrial electron transport occurs coincidentally with alterations in
phosphatidylcholine metabolism as indicated by an increased ratio of long-chain
to short-chain mitochondrial phosphatidylcholine. Moreover, hydrogen peroxide
(H(2)O(2)) generation is significantly increased in mitochondria isolated from
CDAA rats compared with mitochondrial from normal rats, and the NADH-specific
yield of H(2)O(2) is increased by at least 2.5-fold. These findings suggest an
explanation for the rapid onset of oxidative stress and energy compromise in the
choline deficiency model of hepatocellular carcinoma and indicate that dietary
choline withdrawal may be a useful paradigm for the study of mitochondrial
pathophysiology in carcinogenesis.
PMID- 10783323
TI - One-electron oxidation is not a major route of metabolic activation and DNA
binding for the carcinogen 7H-dibenzo[c,g]carbazole in vitro and in mouse liver
and lung.
AB - 7H-Dibenzo[c,g]carbazole (DBC) is a potent multi-site, multi-species carcinogen
present in a variety of complex mixtures derived from the incomplete combustion
of organic matter. Like many carcinogens, DBC requires metabolic activation to an
electrophilic species to exert its mutagenic and carcinogenic effects. One
electron oxidation, leading to the formation of radical cation intermediates, has
been proposed as a mechanism of metabolic activation for DBC in vitro resulting
in unstable DNA adducts. The purpose of this research was to determine whether
one-electron oxidation is a mechanism of activation and DNA binding for DBC in
vivo. Specific depurinating DBC-DNA adducts formed by one-electron oxidation were
analyzed in mouse liver at 4 h following a single i.p. dose of 40 mg/kg of 11
microCi [(14)C]DBC. In addition to five previously published adduct standards,
two newly identified adduct standards were characterized by mass spectrometry and
NMR, namely DBC-6-N7-Ade and DBC-6-N1-Ade; however, neither was observed in mouse
liver. Only the DBC-5-N7-Gua adduct was observed in mouse liver extracts at a
level of 6.5 +/- 1. 8 adducts/10(6) nucleotides. In addition, the formation of AP
sites and stable DBC-DNA adducts was analyzed in mouse liver and lung at 4, 12
and 24 h following a single i.p. dose of 0.4, 4 or 40 mg/kg DBC (n = 3/group).
There was a distinct time- and dose-response of stable DBC-DNA adducts detected
by (32)P-post-labeling. There was not a clear dose-response for formation of AP
sites; however, a significant increase over control levels was observed at the 4
and 40 mg/kg dose groups at 4 and 12 h post dosing, respectively. Quantitative
comparisons indicate that the depurinating DBC-5-N7-Gua adduct constitutes
approximately 0.4% of total adducts measured whereas the stable adducts detected
by (32)P-post-labeling constitute 99.6% of total adducts measured following a 40
mg/kg dose and a 4 h time-point. The data indicate that one-electron oxidation
does occur in mouse liver in vivo. However, one-electron oxidation is a minor
mechanism of activation in that the percentage of total adducts formed through
this route constitutes a minor percentage of the total adducts formed.
PMID- 10783324
TI - The effect of lithocholic acid on proliferation and apoptosis during the early
stages of colon carcinogenesis: differential effect on apoptosis in the presence
of a colon carcinogen.
AB - Lithocholic acid (LCA) is implicated in human and experimental animal
carcinogenesis. Its effect on apoptosis and proliferation of the colonic
epithelium was studied in a 1,2-dimethylhydrazine (DMH)-induced murine
carcinogenesis model. Four groups of mice, control, LCA, DMH and DMH+LCA, were
studied for 4 weeks, a period corresponding to early stages of carcinogenesis.
Apoptosis (AI) and proliferation (PI) indices in the colon were determined by
immunohistochemistry. LCA stimulated apoptosis [AI = 1.2 +/- 0.3% (all values are
the mean +/- SEM) versus control 0.5 +/- 0.1%, P < 0. 05], as did DMH (4.3 +/-
0.8%, P < 0.02). DMH increased apoptosis at the base of the crypt nearly 50-fold,
with no effect at the lumenal third. In mice receiving DMH, LCA suppressed
apoptosis almost completely (0.1 +/- 0.03%); this suppression was complete at the
lower two-thirds of the crypt (AI = 0) and 60% at the lumenal third. LCA
increased proliferation (PI = 22.2 +/- 4.6% versus 15.4 +/- 1% in controls), but
this did not reach statistical significance. DMH increased proliferation (PI =
34.6 +/- 2.3%, P < 0.01). In mice receiving DMH, proliferation (41 +/- 2.9%) was
about two-thirds of the additive effect. LCA affected proliferation, mainly in
the middle third of the crypt; DMH's effect was similar in distribution, but more
pronounced. In mice receiving DMH, LCA shifts proliferation upward, extending it
to the lumenal third of the crypt. LCA's main cell kinetic effect in the colon is
on apoptosis; this effect differs in normal (stimulation) and pre-malignant colon
(nearly complete suppression). LCA does not significantly stimulate proliferation
in either normal or pre-malignant colon. The differential effect of LCA on
apoptosis in the presence of a carcinogen partially explains its effect as a
promoter on colon carcinogenesis in animal models, and may have important
implications for human carcinogenesis.
PMID- 10783325
TI - Exploring the relationship between the inhibition of gap junctional intercellular
communication and other biological phenomena.
AB - The mechanistic relationship of the inhibition of gap junctional intercellular
communication (GJIC) to other toxicological phenomena was explored using a
recently developed method that models the properties of a large population of
molecules chosen to represent the 'universe of chemicals'. The analyses indicate
that inhibition of GJIC is strongly linked to the carcinogenic process in
rodents, to cellular but not systemic toxicity, to biological phenomena that may
involve inflammatory processes and to development effects. The inhibition of GJIC
appears not to be associated with genotoxic mechanisms. With respect to cancer
causation, integration of the analyses suggests that inhibition of GJIC is
involved in non-genotoxic cancer induction or in the non-genotoxic phases of the
carcinogenic process (such as inflammation, cell toxicity, cell proliferation,
inhibition of cell differentiation and apoptosis).
PMID- 10783327
TI - Modulation of base excision repair by low density lipoprotein, oxidized low
density lipoprotein and antioxidants in mouse monocytes.
AB - In the present study, we found that oxidized low density lipoprotein, but not low
density lipoprotein, down-regulated base excision repair activity in extracts of
mouse monocyte cell line PU5-1.8. An enzyme required in this pathway, DNA
polymerase beta, was also down-regulated. In contrast, treatment of monocytes
with a combination of ascorbate and alpha-tocopherol up-regulated base excision
repair activity and expression of DNA polymerase beta. Co-treatment of monocytes
with antioxidants plus oxidized low density lipoprotein prevented down-regulation
by oxidized low density lipoprotein. Oxidative DNA damage, as measured by 8
hydroxyguanine accumulation in genomic DNA, was found in cells treated with
oxidized low density lipoprotein; 8-hydroxyguanine was not found in the cells
treated with low density lipoprotein, antioxidants or oxidized low density
lipoprotein plus antioxidants. These results establish a linkage between the DNA
base excision repair pathway, oxidative DNA damage and oxidized low density
lipoprotein treatment in mouse monocytes. Since oxidized low density lipoprotein
is implicated in chronic disease conditions such as atherogenesis, these findings
facilitate understanding of genetic toxicology mechanisms related to human health
and disease.
PMID- 10783326
TI - Induction of murine intestinal and hepatic peroxiredoxin MSP23 by dietary
butylated hydroxyanisole.
AB - Feeding mice with 2(3)-t-butyl-4-hydroxyanisole (BHA) induces phase II
detoxifying enzymes that inhibit the action of carcinogens. We have found that
dietary BHA induces intestinal and hepatic MSP23 (also called peroxiredoxin I), a
stress-inducible antioxidant, in a manner similar to the induction of glutathione
S-transferases (GSTs). The levels of MSP23 in the proximal intestine and liver,
estimated by immunoblotting, increased approximately 1.9- and 1.3-fold,
respectively, in mice fed a diet containing 0.7% (w/w) BHA for 7 days. The level
of MSP23 mRNA in these tissues also increased more than 2-fold after mice were
fed BHA, suggesting that the induction of MSP23 is controlled at the
transcription level. Immunostaining of the small intestine shows that MSP23 is
expressed mainly in the columnar epithelial cells. The induction of MSP23 may be
important to protect the cells and tissues against toxic electrophiles and
reactive oxygen species.
PMID- 10783328
TI - mRNA expression patterns in different stages of asbestos-induced carcinogenesis
in rats.
AB - Human malignant mesotheliomas are induced almost exclusively by fibrous dusts.
The nature of interactions between fibers and target cells, and the molecular
mechanisms leading to tumorigenesis, are not yet understood. Here, the mRNA
expression patterns at different stages of asbestos-induced carcinogenesis in
rats were monitored by suppression subtractive hybridization (SSH) and array
assay. Several genes were upregulated in pretumorous tissues from asbestos
treated rats, in asbestos-induced tumors and in cells treated with asbestos in
vitro. The upregulation of the proto-oncogene c-myc, fra-1 and egfr in fiber
induced carcinogenesis was demonstrated at different stages of carcinogenesis. A
possible role of Fra-1 as one of the dimeric proteins generating the AP-1
transcription factor was substantiated by its dose-dependent expression in
mesothelial cells treated with asbestos in vitro. The upregulation of osteopontin
(an extracellular matrix protein) and of zyxin and integrin-linked kinase
(intracellular proteins associated with the focal adhesion contact), indicate
that fibers may affect integrin-linked signal transduction and extracellular
matrix proteins.
PMID- 10783329
TI - Suprabasal expression of the human papillomavirus type 16 oncoproteins in mouse
epidermis alters expression of cell cycle regulatory proteins.
AB - Human papillomavirus (HPV) survives by reactivating DNA replication in post
mitotic cells. In the present study, we describe a mouse model of HPV-dependent
disease. In these mice, DNA synthesis is activated in suprabasal keratinocytes,
leading to acanthosis, parakeratosis and enhanced desquamation. The full-length
E6/E7 transcript and two alternately spliced products are produced and in most
lines the predominant product is E6*. In the present study, we examine the
effects of E6/E7 on cell cycle regulatory protein expression. E6/E7 expression in
mouse epidermis is correlated with increased levels of the p53, p21, p27, cdk2,
cdk4, cdk6, cyclin D1 and cyclin E regulatory proteins. Hyperproliferation is
also observed in the buccal mucosa and the tongue epithelia of E6/E7 mice, and
p53 levels are markedly increased in these epithelia. These results suggest that
the major changes in cell cycle regulatory protein expression are in response to
the presence of E7 and that E6 has a lesser impact.
PMID- 10783330
TI - Rapid induction of uterine tumors with p53 point mutations in heterozygous p53
deficient CBA mice given a single intraperitoneal administration of N-ethyl-N
nitrosourea.
AB - To investigate the sensitivity of heterozygous p53-deficient CBA mice to
carcinogens, 20 female mice [p53(+/-)] and 20 wild-type littermates [p53(+/+)]
were given an intraperitoneal injection of 120 mg/kg body wt of N-ethyl-N
nitrosourea (ENU) and were maintained without any other treatment for a further
26 weeks. Histopathology showed that uterine tumors (endometrial polyps and
stromal sarcomas) and lung adenomas were induced in both p53(+/-) and p53(+/+)
mice. The incidence of uterine tumors and lung adenomas (94% and 81%,
respectively) in p53(+/-) mice was significantly greater than that in p53 (+/+)
mice (37% and 42%, respectively). Malignant lymphomas were only induced in p53(+/
) mice, at an incidence of 31%. Concerning uterine tumors and preneoplastic
lesions, there were endometrial stromal sarcomas and atypical hyperplasias of the
endometrial gland in 90% and 63%, respectively, of p53(+/-) mice, with
significantly greater incidences than in p53(+/+) mice. Gene analysis revealed
GCG-->GTG point mutations in codon 135 of exon 5 of the p53 allele in all of the
uterine endometrial stromal sarcomas examined. Our results suggest that female
p53(+/-) CBA mice are very susceptible to uterine carcinogenesis, providing a
useful model for ENU-induced uterine tumors.
PMID- 10783331
TI - Radiation-induced mammary tumors in virgin and parous rats administered
contraceptive steroids, 17alpha-ethinylestradiol and norethisterone.
AB - Oral contraceptives are used among women worldwide, and radiation is being used
increasingly for diagnosis or therapy. We have investigated the effects of
contraceptive steroids on the risk of mammary tumors initiated by radiation.
Virgin rats received whole-body irradiation with 2.6 Gy gamma-rays 1 month after
the administration of low- or high-dose pellets of contraceptive steroids, such
as 17alpha-ethinylestradiol (EE(2)) combined with 19-norethisterone (NET). The
high-dose pellet was removed 1 month after irradiation, but administration of the
low-dose pellet was continued for up to 1 year. The incidence (33.3%) of mammary
tumors initiated with radiation was not modified by the long-term administration
of the low-dose pellets. However, the incidence (58. 3%) was increased
significantly by the irradiation during administration of the high-dose pellets,
but no significant difference in the proportion of adenocarcinoma and
fibroadenoma was observed. Meanwhile, parous rats were irradiated with 2.6 Gy
gamma-rays at weaning, a period of greater susceptibility to radiation, and then
were implanted with the low-dose pellets 1 month later. The highest incidence
(90%) of mammary tumors was detected in the parous rats. The proportion of
adenocarcinomas in the parous irradiated rats increased significantly on
treatment with the low-dose pellets. The results suggest that administration of
the high-dose pellets of EE(2)-NET, but not of the low-dose pellets, enhances
susceptibility to the initiation by gamma-rays of mammary tumors in virgin rats,
and that the low-dose pellets act as a tumor promoter in the mammary glands of
parous rats irradiated at weaning.
PMID- 10783332
TI - Cadmium mutagenicity and human nucleotide excision repair protein XPA: CD, EXAFS
and (1)H/(15)N-NMR spectroscopic studies on the zinc(II)- and cadmium(II)
associated minimal DNA-binding domain (M98-F219).
AB - Human XPA is a 31 kDa protein involved in nucleotide excision repair (NER), a
ubiquitous, multi-enzyme pathway responsible for processing multiple types of DNA
damage in the eukaryotic genome. A zinc-associated, C4-type motif (C105-X(2)-C108
X(17)-C126-X(2)-C129) located in the minimal DNA-binding region (M98-F219) of XPA
(XPA-MBD) is essential for damaged DNA recognition. Cadmium is a known carcinogen
and can displace the zinc in many metal-binding proteins. It has been suggested
that the carcinogenic properties of cadmium may result from structural changes
effected in XPA when Cd(2+) is substituted for Zn(2+) in the metal-binding site.
The solution structure of XPA-MBD containing zinc(II) has recently been
determined [Buchko et al., (1998) Nucleic Acids Res., 26, 2779-2788; Buchko et
al., (1999) Biochemistry, 38, 15116-15128]. To assess the effects of cadmium(II)
substitution on the structure of XPA-MBD, XPA-MBD was expressed in minimal medium
supplemented with cadmium acetate to yield a protein that was almost exclusively
(>95%) associated with cadmium(II) (CdXPA-MBD). Extended X-ray absorption fine
structure spectra collected on ZnXPA-MBD and CdXPA-MBD in frozen (77 K) 15%
aqueous glycerol solution show that the metal is coordinated to the sulfur atoms
of four cysteine residues with an average metal-sulfur bond length of 2.34 +/-
0.01 and 2.54 +/- 0.01 A, respectively. Comparison of the circular dichroism, two
dimensional (1)H,(15)N-HSQC, and three-dimensional (15)N-edited HSQC-NOESY
spectra of ZnXPA-MBD and CdXPA-MBD show that there are no structural differences
between the two proteins. The absence of major structural changes upon
substituting cadmium(II) for zinc(II) in XPA suggests that cadmium-induced
mutagenesis is probably not due to structural perturbations to the zinc-binding
core of XPA.
PMID- 10783333
TI - Oxidative DNA damage in fetal tissues after transplacental exposure to 3'-azido
3'-deoxythymidine (AZT).
AB - The nucleoside analogue 3'-azido-3'-deoxythymidine (AZT) has been used
successfully to reduce the incidence of transplacental and perinatal transmission
of the HIV virus. However, prolonged treatment with high doses of AZT is utilized
in this therapy, and AZT has been found to be a perinatal carcinogen in mice. Any
possible perinatal carcinogenic side effects in the human can best be managed if
the mechanism is understood. AZT targets mitochondria and might cause increased
intracellular production of reactive oxygen species (ROS). We tested whether
transplacental AZT may cause oxidative damage in nuclear DNA of fetal tissues. CD
1 Swiss pregnant mice were treated with the transplacental carcinogenesis regimen
(25 mg/day AZT, for gestation days 12-18) and tissues collected on the day of
birth. Significant increases in 8-oxo-2'-deoxyguano- sine (8-oxo-dG) were found
in the livers, a target tissue for transplacental carcinogenesis, and in the
kidneys. A non-significant increase occurred in brain, with no change in lung.
Tissues were also obtained from fetal patas monkeys (Erythrocebus patas), whose
mothers had received 10 mg AZT/day during the last half of gestation. Although
limited numbers of samples were available, possible increases in 8-oxo-dG were
noted, relative to controls, for placenta and for fetal lung and brain (P = 0.055
for treatment-related increases in these tissues). These results suggest that an
increase in reactive oxygen species could contribute to the mechanism of
transplacental carcinogenesis by AZT in mice, and that this may also occur in
primates.
PMID- 10783334
TI - Expression of PGF(2alpha) receptor mRNA in normal, hyperplastic and neoplastic
skin.
AB - Reverse transcription polymerase chain reaction (RT-PCR) and Northern blot
analysis was used to determine the level of expression of prostaglandin F(2alpha)
(FP) receptor mRNA in various mouse tissues, including normal, hyperplastic and
neoplastic mouse epidermis. Steady-state concentrations of FP receptor mRNA were
low in normal and hyperplastic epidermis. The response of the epidermis to the
phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) was biphasic in that FP
receptor mRNA was increased immediately after treatment, followed by a long
lasting down-regulation at later time points. FP receptor mRNA was down-regulated
in the majority of papillomas obtained by the mouse skin carcinogenesis
initiation-promotion protocol. In carcinomas, FP receptor mRNA expression was
similar to that in normal epidermis. The steady-state concentration of FP mRNA
was inversely correlated with PGF(2alpha) levels in normal and hyperplastic
epidermis and in papillomas, indicating that FP mRNA expression is regulated by
this eicosanoid.
PMID- 10783336
TI - Resignation
PMID- 10783335
TI - Mitomycin C and diepoxybutane action mechanisms and FANCC protein functions:
further insights into the role for oxidative stress in Fanconi's anaemia
phenotype.
AB - Evidence for redox-dependent toxicities of mitomycin C (MMC) and diepoxybutane
(DEB), through different mechanisms, has been related to the phenotypic defect(s)
of Fanconi's anaemia (FA) cells, due to their excess sensitivity to these agents.
Recent data have pointed to interactions of the FANCC protein (encoded by the FA
complementation group C gene, FA-C) with NADPH cytochrome P450 reductase and
glutathione S-transferase (GST), two activities involved in either triggering or
detoxifying reactive intermediates, including xenobiotics and reactive oxygen
species. A body of evidence points to: (i) oxygen hypersensitivity of FA cells;
(ii) oxygen-dependent MMC and DEB toxicity; (iii) excess oxidative DNA damage in
FA cells; and (iv) DEB-induced glutathione depletion and GST inhibition. The
available evidence corroborates the previously suggested role for oxidative
stress in FA phenotype and disease progression, shedding new light on the redox
dependent mechanisms in MMC and DEB toxicities, and suggesting a direct
association of oxidative stress with the primary genetic defect in FA.
PMID- 10783337
TI - In appreciation of professor R.G.Edwards, founding editor of the human
reproduction journals
PMID- 10783338
TI - What are the ownership rights for gametes and embryos? Advance directives and the
disposition of cryopreserved gametes and embryos.
PMID- 10783339
TI - Gender reassignment and assisted reproduction. Evaluation of multiple aspects.
PMID- 10783340
TI - Alternative sources of gametes: reality or science fiction?
AB - Although great progress has been made in both the investigation and treatment of
infertility, a considerable number of patients still fail to conceive.
Spermatogenic failure and/or oocyte ageing appear to be responsible for a large
proportion of cases. The use of donor gametes may bring legal, ethical and even
social problems of acceptance that can discourage infertile couples from the
donor route. Fortunately, emerging reproductive technologies and preliminary
results from animal experiments provide some hope for alternative sources of
gametes through which these infertile patients can finally conceive their own
genetic child. In conjunction with intracytoplasmic sperm injection (ICSI),
fertilization of human oocytes with immature sperm precursors, e.g. spermatids
and even secondary spermatocytes, has resulted in healthy babies. Pregnancies
have also resulted from the use of spermatids derived from in-vitro
spermatogenesis. In the mouse, even primary spermatocytes appear able to
participate in normal embryogenesis. In view of the possibility for
transplantation and even xenotransplantation of spermatogonia to a host testis in
animals, a similar use of human male stem cells might provide an attractive
source for the treatment of males with arrested spermatogenesis, as well as male
cancer patients. Transplantation of somatic cell nuclei and their haploidization
within oocytes may prove to be a practical way of eradicating age-related
aneuploidy and so constitute an innovative source of healthy oocytes. Most
importantly, however, the safety of the procedures described here needs to be
proven before their application to the human arena. Finally, we discuss the
implications of cytoplasmic quality and of genetic imprinting in the context of
these manipulations.
PMID- 10783341
TI - Empty follicle syndrome: evidence for recurrence.
AB - The empty follicle syndrome (EFS) is a frustrating condition in which no oocytes
are retrieved in an IVF cycle. Although this is an infrequent event in IVF
patients, the economic consequences as well as the emotional frustration of a
cancelled cycle due to the inability to obtain oocytes are enormous. The
mechanisms responsible for EFS remain obscure, though many hypotheses have been
put forward ranging from dysfunctional folliculogenesis to a drug-related
problem. We found that the EFS is a rare event (1.8% of oocyte retrievals) but
with profound implications for counselling the couple about their future
reproductive performance. The chances of recurrence of EFS increase with the age
of the patient (24% recurrence rate for the 35-39 year age group, and 57% for
those over 40 years). We postulate that ovarian ageing, through altered
folliculogenesis, may be implicated in the aetiology of EFS and its recurrence.
PMID- 10783342
TI - Increased risk of early pregnancy loss by profound suppression of luteinizing
hormone during ovarian stimulation in normogonadotrophic women undergoing
assisted reproduction.
AB - The impact of suppressed concentrations of circulating luteinizing hormone (LH)
during ovarian stimulation on the outcome of in-vitro fertilization or
intracytoplasmic sperm injection treatment in 200 consecutive, normogonadotrophic
women (couples) was analysed retrospectively. A standard stimulation protocol
with mid-luteal gonadotrophin-releasing hormone (GnRH) agonist down-regulation
and ovarian stimulation with recombinant follicle stimulating hormone (FSH) was
used in all cases. Blood was sampled from each woman on stimulation days 1 and 8
for analysis of oestradiol and LH in serum. A threshold value of serum LH of 0.5
IU/l on stimulation day 8 (S8) was chosen to discriminate between women with low
or 'normal' LH concentrations. Low concentrations of LH on S8 (<0.5 IU/l) were
found in 49% (98/200) of the women. This group of women was comparable with the
normal LH group with regard to pre-treatment clinical parameters, and to the
parameters characterizing the stimulation protocol with the exception of serum
oestradiol concentration, which on S8 was significantly lower than in the normal
LH group (P < 0.001). The proportion of positive pregnancy tests was similar in
the two groups (30% versus 34% per started cycle), but the final clinical
treatment outcome was significantly different, with a five-fold higher risk of
early pregnancy loss (45% versus 9%; P < 0.005) in the low LH group and
consequently a significantly poorer chance of delivery than in the normal LH
group. It is concluded that a substantial proportion of normogonadotrophic women
treated with GnRH agonist down-regulation in combination with FSH, devoid of LH
activity, experience LH suppression, which compromises the treatment outcome.
Whether these women would benefit from supplementation with recombinant LH or
human menopausal gonadotrophin during ovarian stimulation, remains to be proven
in the future by prospective randomized trials.
PMID- 10783343
TI - Consequences on gonadotrophin secretion of an early discontinuation of
gonadotrophin-releasing hormone agonist administration in short-term protocol for
in-vitro fertilization.
AB - Administration of gonadotrophin-releasing hormone (GnRHa) agonists, used in IVF
short-term protocols to initiate follicular recruitment, may be restricted to the
early follicular phase without any further risk of LH surge. However,
consequences of an early discontinuation upon residual endogenous gonadotrophin
secretion are still unknown. Here, the effects of early cessation of GnRH agonist
upon gonadotrophin secretion and ovarian parameters of IVF cycles were
investigated. A total of 230 normo-ovulatory women were prospectively allocated
to one of the two regimens: decapeptyl-GnRH (100 microgram) was daily injected
either from day 1 to the triggering of ovulation (group 1) or for the first 7
days (group 2). Exogenous gonadotrophins (150 IU) were administered on day 4 and
5 with a subsequent adjustment. Detections of free alpha subunit and dimeric LH
were performed by highly specific 'two site' monoclonal immunoradiometric assays.
The results show that early discontinuation of GnRH agonist administration was
associated with a sharp decrease in both plasma free alpha subunit and dimeric LH
concentrations while plasma oestradiol response to exogenous gonadotrophins was
reduced. Other ovarian parameters and pregnancy rate were unchanged. These data
indicate that endogenous LH secretion is maintained by a daily administration of
GnRH agonist and may contribute to the final follicular maturation.
PMID- 10783344
TI - Ovarian stimulation for assisted reproduction with HMG and concomitant midcycle
administration of the GnRH antagonist cetrorelix according to the multiple dose
protocol: a prospective uncontrolled phase III study.
AB - A total of 346 women with normal ovulatory function was stimulated with human
menopausal gonadotrophins (HMG) to attain ovarian stimulation for IVF or
intracytoplasmic sperm injection (ICSI). Stimulation with HMG started on cycle
day 2 or 3. After 6 days of stimulation, Cetrorelix in its minimum effective
multiple dose of 0. 25 mg/day, was administered daily until induction of
ovulation. In total, 333 patients (96.2%) reached the day of HCG administration,
and 324 (93.6%) underwent oocyte retrieval. A mean of 25.2 ampoules of HMG was
applied for a mean of 10.4 days. Cetrorelix was administered for a mean time
lapse of 5.7 days. The mean normal fertilization rate was 60% in the IVF group
and 59% in the ICSI group. Seventy pregnancies were attained, reflecting an
ongoing clinical pregnancy rate of 24% per transfer. The ongoing clinical
implantation rate was 11.4%. Only three cases of raised luteinizing hormone (LH)
(>/=10 IU/l) with increased progesterone secretion (>/=1 ng/ml) were observed
after initiation of Cetrorelix administration, reflecting an incidence of
premature luteinization of 0.9%. The abortion rate was 17%. The incidence of
severe ovarian hyperstimulation syndrome (World Health Organization grade III)
was as low as 0.6%.
PMID- 10783345
TI - Induction of ovulation in women undergoing assisted reproductive techniques:
recombinant human FSH (follitropin alpha) versus highly purified urinary FSH
(urofollitropin HP).
AB - This multicentre, open, randomized, study compared the efficacy and safety of
recombinant follicle stimulating hormone (rFSH; follitropin alpha) with highly
purified urinary human FSH (uFSH; urofollitropin HP) in women undergoing
ovulation induction for assisted reproductive techniques. Following long down
regulation with buserelin, patients received two ampoules of 75 IU (150 IU) s.c.
rFSH or highly purified uFSH for 6 days, after which the dose could be increased
until they fulfilled the criteria for human chorionic gonadotrophin (HCG)
administration. Of 168 patients recruited, 155 received at least one dose of FSH,
and 137 received HCG [68: rFSH (85%); 69: uFSH (92%)]. Following oocyte retrieval
and fertilization, up to three embryos were replaced/patient and luteal support
was given. The mean number of oocytes retrieved/patient was 10.2 +/- 6.0 for rFSH
patients compared with 10.8 +/- 6.1 in the uFSH group (not significant). There
was a trend towards fewer ampoules used (22.3 +/- 6.5 versus 24.3 +/- 6.5),
higher pregnancy (44.3 versus 41.4%) and live birth rates (33.8 versus 26.7%), as
well as a lower miscarriage rate (0.0 versus 16.7%) in favour of rFSH. However,
no significant differences in efficacy parameters were recorded. Ovarian
hyperstimulation syndrome occurred in 8.6% and 7.9% of rFSH and uFSH patients
respectively. In conclusion, this protocol was effective in inducing multiple
follicular development and high numbers of oocytes were retrieved with both
drugs.
PMID- 10783346
TI - Safety and efficacy of oestriol for symptoms of natural or surgically induced
menopause.
AB - To assess the safety and efficacy of oestriol in relieving post-menopausal
symptoms 53 post-menopausal Japanese women with climacteric symptoms, 27 with
natural menopause (group I) and 26 with surgically induced menopause (group II),
received oral oestriol, 2 mg daily for 12 months. Clinical parameters including
Kupperman index (KI) and the degree of satisfaction with symptomatic relief;
serum concentrations of oestradiol, FSH and LH; serum lipids; blood pressure;
bone mineral density, serum calcium (Ca), alkaline phosphatase (ALP), and urinary
Ca were compared between the two groups. Oestriol improved KI in groups I and II
by 49 and 80% respectively. Satisfaction with treatment was 85% in group I and
93% in group II. For both parameters, values were significantly different between
groups I and II (P < 0.05 for both). Serum concentrations of oestradiol, FSH and
LH changed in group I versus group II 6 months after initiation. A significant
decrease in serum ALP and Ca/Cr was observed in group I at 6 months. Except for
serum triglycerides, oestriol had no significant effect on lipids. Systolic and
diastolic blood pressures were significantly decreased in group I at 3 months
versus baseline. Slight vaginal bleeding occurred in 14.3% of group I.
Histological evaluation of the endometrium in all women of group I and ultrasound
assessment of the breasts following 12 months of oestriol treatment found normal
results in all women. Therefore, oestriol appeared to be safe and effective in
relieving symptoms of menopausal women. The beneficial biochemical effects of
oestriol were marked in the natural menopause. Overall, oestriol may serve as a
good choice for hormone replacement therapy to protect against other climacteric
symptoms in post-menopausal women who do not need medication for osteoporosis or
coronary artery disease.
PMID- 10783347
TI - Value of serum and follicular fluid cytokine profile in the prediction of
moderate to severe ovarian hyperstimulation syndrome.
AB - The aim of this study was to examine the role of serum and follicular fluid pro
inflammatory cytokines and vascular endothelial growth factor (VEGF) in the
prediction of ovarian hyperstimulation syndrome (OHSS). A total of 156
consecutive women undergoing in-vitro fertilization were recruited. The study
group comprised 12 women who subsequently developed moderate (n = 7) or severe (n
= 5) OHSS. The two control groups were comprised of a randomized selection of 12
high-risk and 12 low-risk women in whom OHSS did not develop. Serum was collected
on days of human chorionic gonadotrophin, oocyte retrieval, and embryo transfer.
Serum and follicular fluid concentrations of interleukin (IL)-6, IL-8, tumour
necrosis factor-alpha (TNF-alpha), and VEGF were measured. Follicular fluid IL-6
concentrations at the time of oocyte retrieval and serum IL-8 concentrations at
the time of embryo transfer were significantly higher in the OHSS compared to the
two control groups (P = 0.026 and P = 0.017 respectively). Serum concentrations
of TNF-alpha and VEGF showed no statistically significant difference between the
OHSS group and the controls at any studied time point. This study suggests that
follicular fluid IL-6 concentrations at the time of oocyte retrieval and serum IL
8 concentrations on the day of embryo transfer may serve as early predictors for
this syndrome.
PMID- 10783349
TI - Ovarian antibodies, FSH and inhibin B: independent markers associated with
unexplained infertility.
AB - Premature menopause and unexplained infertility are associated with ovarian
antibodies, a marker of ovarian autoimmunity. In premature menopause, FSH is also
elevated while in unexplained infertility FSH concentrations are often normal.
The relationship of ovarian antibodies and FSH and inhibin B, as markers of
follicle function, was investigated in unexplained infertility. Ovarian
antibodies were determined by immunoassay in comparison to normal controls (n =
12); 51.9% were positive at two SD (P < 0.05) and 38.5% were positive at three SD
above the control mean (P < 0.01). In this study three SD above the control mean
was considered positive. In unexplained infertility, three out of 10 (30%) had
elevated day 3 FSH (>10 mIU/ml) and ovarian antibodies, while 17/42 (40%) had
normal FSH (<10 mIU/ml) and ovarian antibodies. In women with normal FSH, two out
of seven (29%) had low inhibin B concentrations (<33 pg/ml) and ovarian
antibodies, and 15/35 (43%) had normal inhibin B concentrations (> 33 pg/ml) and
ovarian antibodies. Similarly, when women with and without ovarian antibodies
were compared there was no difference in mean FSH or mean inhibin B
concentrations. Thus, unlike other endocrine autoimmune disorders, hormone
concentrations are not predictors of potential ovarian autoimmunity. This
suggests that in unexplained infertility ovarian antibodies are an independent
marker of potential ovarian failure, and may precede changes in regulatory
hormones.
PMID- 10783348
TI - Hyperreactio luteinalis despite the absence of a corpus luteum and suppressed
serum follicle stimulating concentrations in a triplet pregnancy.
AB - Hyperreactio luteinalis is characterized by moderate to marked cystic enlargement
of the ovaries related to multiple theca lutein cysts and is associated with very
high sex steroid concentrations. It is a rare condition especially in the first
trimester. The case described below is believed to be the only case of
hyperreactio luteinalis reported following frozen embryo transfer. This case
provides an opportunity to gain further insight into the mechanism responsible
for this unusual condition. The 30 year old woman demonstrated a slightly
elevated LH/FSH ratio (5 and 3 mIU/ml respectively) and normal baseline androgen
concentrations. Two years following oocyte retrieval she had a second frozen
embryo transfer. The ovaries were normal size when the embryos were transferred
and androgens were still normal. The ovaries did not begin to enlarge until 51
days from transfer. A dichorionic intrauterine pregnancy with monozygotic twins
in the left gestational sac was seen. Eventually, 86 days from transfer, the
ovaries enlarged to 145x103x116 mm right; and 83x95x117 mm left. Serum oestradiol
was 30 078 pg/ml, beta-human chorionic gonadotrophin (HCG) 239 920 mIU/ml, serum
progesterone >160 ng/ml, total testosterone 2254 ng/dl, free testosterone 42.3
pg/ml and androstenedione 7328 ng/dl. Throughout the first trimester, serum FSH
was <1 mIU/ml. Thus, neither FSH nor a corpus luteum is necessary to initiate
this syndrome.
PMID- 10783350
TI - Changes in serum inhibin, activin and follistatin concentrations during puberty
in girls.
AB - Serum concentrations of inhibin A, inhibin B, activin A and follistatin were
determined using two-site enzyme-linked immunosorbent assays (ELISA) during
pubertal ovarian development in 28 girls and five follicular phase women. Blood
obtained every 15 to 20 min overnight was pooled for peptide determination. Serum
inhibin A concentrations increased in mid puberty, exhibiting positive
correlations with bone age (r = 0.527, P = 0.0016) and oestradiol concentrations
(r = 0.581, P = 0.0005). Inhibin B concentrations peaked in mid puberty and
declined thereafter, but remained greater than concentrations seen in prepubertal
girls, and correlating positively with oestradiol (r = 0.362, P = 0.046) and
follicle stimulating hormone (FSH) concentrations (r = 0.369, P = 0.038). Total
activin A concentrations did not vary significantly across pubertal stages. Total
follistatin concentrations, determined by radioimmunoassay, decreased with
advancing puberty, exhibiting negative correlations with bone age (r = -0.634, P
= 0.0001) and oestradiol concentration (r = -0.687, P = 0.0001). Follistatin
concentrations determined by an ELISA specific for follistatin 288 were greatest
in mid-pubertal girls, but concentrations in late puberty were less than those in
early puberty. The free follistatin assay indicated that all circulating
follistatin was activin-bound. These results suggest that significant changes in
serum concentrations of FSH-regulatory peptides accompany the onset of puberty.
PMID- 10783351
TI - A tale of two syndromes: ovarian hyperstimulation and abdominal compartment.
AB - Abdominal compartment syndrome complicated severe ovarian hyperstimulation in a
35 year old woman with multiple bowel resections due to Crohn's disease. Pain
from ovarian enlargement necessitated hospital admission. Despite intravenous
fluid administration and heparin prophylaxis, ilio-femoral deep vein thrombosis
developed. Treatment by intravenous heparin was complicated by repeated intra
ovarian bleeding, anaemia and acute renal failure requiring haemodialysis. Intra
abdominal pressures were elevated. After placement of an inferior vena caval
filter and discontinuation of heparin, there was slow spontaneous recovery
without surgery.
PMID- 10783352
TI - Transfer of zona-free embryos improves outcome in poor prognosis patients: a
prospective randomized controlled study.
AB - Assisted zona hatching (AZH) has been used in IVF programmes for several years.
Recently one group has reported successful pregnancies after transfer of zona
free blastocysts. The aim of our study was to evaluate outcomes after transfer of
zona-free day 3 embryos. Two groups of women undergoing intracytoplasmic sperm
injection (ICSI) were included in the study. Group A consisted of 52 women under
the age of 40 years undergoing their first ICSI attempt. They were alternately
randomized to receive zona-free embryos (27 women) and zona-intact embryos (25
women). The second group (group B) included 71 women with a poor prognosis, as
defined by age 40 years or more, and/or at least two previous failed IVF/ICSI
attempts. They were randomized in a 3:4 ratio (30 zona-free, 41 zona-intact).
Acid Tyrode's solution was used to remove the zona pellucida before embryo
transfer on day 3 after oocyte collection. The pregnancy rate in group A was not
significantly improved when the zona pellucida was removed. However, in the poor
prognosis group B, zona removal resulted in a significantly higher pregnancy rate
when compared with controls (23 versus 7.3%). We conclude that complete removal
of the zona pellucida can improve pregnancy rates in women with poor IVF/ICSI
prognosis.
PMID- 10783353
TI - External validation of the templeton model for predicting success after IVF.
AB - This study aimed to externally validate the prognostic model presented by
Templeton in 1996 for live births resulting from IVF treatment. Data were used
from the University Hospital, Nijmegen, The Netherlands, from March 1991 to
January 1999. The predictive capacity of the model in our population
discriminated between those women with a low probability of success and those
with a relatively high probability. Despite these encouraging findings, our data
show that implementation of the model in clinical decision-making remains
difficult. The Templeton model is not applicable or usable in daily clinical
practice, because the model did not give more information about the prognosis for
the vast majority of the patients. Therefore, the search for better prognostic
factors resulting in better predictive models should continue.
PMID- 10783354
TI - Non-homogeneous hyperechogenic pattern 3 days after embryo transfer is associated
with lower pregnancy rates.
AB - The purpose of this study was to investigate the relationship between mid-luteal
phase echo patterns and IVF-embryo transfer outcome in women who have
demonstrated adequate endometrial development by the late proliferative phase. A
prospective study was carried out of 86 patients undergoing IVF-embryo transfer
and 86 patients undergoing frozen embryo transfer who all underwent sonographic
monitoring of the endometrium 3 days after embryo transfer. The cycles were
classified into two groups: those with the homogeneous hyperechogenic (HH)
pattern and those without it. The women who had an HH pattern had higher clinical
pregnancy (32.8 versus 10.7%, P < 0.05) and implantation rates in stimulated
cycles (14.3 versus 4.1%, P < 0.05 respectively) than those that did not. There
was no significant difference in the clinical pregnancy or implantation rates by
echo pattern (18.2 and 8.1% for non-HH and 18. 7 and 8.0% for HH respectively) in
frozen embryo transfer cycles. These data demonstrate that in embryo transfer
cycles where ovarian stimulation was used, there were decreased pregnancy and
implantation rates in cycles where the HH pattern was not observed 3 days after
transfer. The failure of the endometrium to display this pattern may indicate
some endometrial abnormality resulting in implantation defects.
PMID- 10783355
TI - Fifteen years experience with an in-vitro fertilization surrogate gestational
pregnancy programme.
AB - The purpose of our study was to review and evaluate retrospectively the
experience of an in-vitro fertilization (IVF) surrogate gestational programme in
a tertiary care and academic centre. In a 15 year period from 1984 to 1999, a
total of 180 cycles of IVF surrogate gestational pregnancy was started in 112
couples. On average, the women were 34.4 +/- 4.4 years of age, had 11.1 +/- 0.72
oocytes obtained per retrieval, 7.1 +/- 0.5 oocytes fertilized and 5. 8 +/- 0.4
embryos subsequently cleaved. Sixteen cycles (8.9%) were cancelled due to poor
stimulation. Except for six cycles (3.3%) where there were no embryos available,
an average of 3.2 +/- 0.1 embryos was transferred to each individual recipient.
The overall pregnancy rate per cycle after IVF surrogacy was 24% (38 of 158),
with a clinical pregnancy rate of 19% (30 of 158), and a live birth rate of 15.8%
(25 of 158). When compared to patients who underwent a hysterectomy, individuals
with congenital absence of the uterus had significantly more oocytes retrieved (P
< 0.006), fertilized, cleaved and more embryos available for transfer despite
being of comparable age. IVF surrogate gestation is an established, yet still
controversial, approach to the care of infertile couples. Take-home baby rates
are comparable to conventional IVF over the same 15 year span in our programme.
Patients with congenital absence of the uterus responded to ovulation induction
better than patients who underwent a hysterectomy, perhaps due in part to ovarian
compromise from previous surgical procedures.
PMID- 10783356
TI - The value of Chlamydia trachomatis antibody testing as part of routine
infertility investigations.
AB - Laparoscopy is considered the gold standard for the evaluation of tubal disease
but it is an invasive and costly procedure. Chlamydia trachomatis antibody
testing is simple and inexpensive and causes minimal inconvenience to the
patient. Using the micro-immunofluorescence technique we assessed the
significance of positive serology. There was a marked association between the
titre and the likelihood of tubal damage. In the group with low titres (1 in 32)
there was only a 5% incidence of tubal damage; however, there was a progressive
increase in the incidence of tubal damage in those with higher titres. Twenty out
of 57 patients with titres higher than 1 in 32 had tubal damage (35%). The
difference between the two groups was statistically significant (P < 0.0001,
chi(2) test). By using C. trachomatis antibody testing more widely it may be
possible to reduce the number of laparoscopies performed. It should therefore
become an integral part of the fertility work-up.
PMID- 10783357
TI - Transmissions of hepatitis C virus during the ancillary procedures for assisted
conception.
AB - Since mother to child transmissions of hepatitis C virus (HCV) have been reported
to be low, teams involved in assisted reproductive technologies have accepted HCV
positive patients into their programmes. We report in the present paper two cases
of undoubted patient to patient HCV transmission while patients were attending
for assisted conception. In both cases, HCV genotyping and sequencing of the
first hypervariable region of the HCV genome provided molecular evidence for
nosocomial transmission. Investigations made to elucidate the route of
contamination have shown that the most likely route of contamination is through
healthcare workers. Such nosocomial HCV infection has been reported in other
healthcare situations, mainly in dialysis units, and physical proximity was also
suspected to be at the origin of the infection. We conclude that assisted
reproduction teams must be very prudent when including such patients in their
programmes.
PMID- 10783358
TI - The measurement of endometrial perfusion in norplant users: a pilot study.
AB - The use of progestogens without oestrogen is commonly associated with irregular
menstrual bleeding. Oestrogens and progestogens are both thought to influence
endometrial perfusion; changes in endometrial perfusion may contribute to
vascular fragility and breakdown. In this study, endometrial perfusion was
measured using laser-Doppler fluxmetry in women in the secretory phase of the
menstrual cycle before and 4-6 weeks after insertion of the low-dose long-acting
levonorgestrel contraceptive implant system, Norplant. Endometrial perfusion was
also measured in women exposed to Norplant for up to 19 months. There was no
significant difference between endometrial perfusion in control cycles (27.2 flux
units +/- 5.5, SEM) and at 4-6 weeks after Norplant insertion (16.3 flux units +/
5.0), a time when irregular bleeding and spotting are common. Endometrial
perfusion was no different from controls after longer periods of Norplant
exposure (35.7 flux units +/- 7.2). No direct relationships between endometrial
perfusion and plasma concentrations of ovarian steroid hormones were
demonstrated. Short-term endometrial vasomotion was largely abolished during
Norplant exposure.
PMID- 10783360
TI - Circulating concentrations of the antiprogestins CDB-2914 and mifepristone in the
female rhesus monkey following various routes of administration.
AB - The overall aim of these studies was to investigate the oral and i.m.
bioavailability of CDB-2914 in intact female rhesus monkeys, and to compare the
serum concentrations of CDB-2914 with that of mifepristone following oral
administration. In the first study, a 50 mg bolus of CDB-2914 per monkey was
administered intravenously, orally or intramuscularly. The area under the serum
concentration-time curve for 72 h (AUC(0-72)) following i.v. injection was 18 320
+/- 2718 ng/ml*h, and that for oral administration was 10 464 +/- 3248 ng/ml*h.
Thus, the oral bioavailability of CDB-2914 equivalents was 56%. The AUC(0-168 h)
following i.m. injection was 11 226 +/- 1130 ng/ml*h. Therefore, the i.m.
bioavailability of CDB-2914 equivalents was 62%. In the second study, the serum
concentrations of CDB-2914 and mifepristone equivalents were compared following
an oral bolus dose in two different formulations. When administered at 5 mg/kg in
aqueous suspending vehicle (ASV), the mean peak serum concentration (C(max)) of
CDB-2914 equivalents (192 +/- 64 ng/ml) occurred at 5 +/- 1 h, whereas the C(max)
of mifepristone equivalents (82 +/- 25 ng/ml) occurred at 3 +/- 1 h. Following
administration in gelatin capsules (35 mg/monkey), the C(max) of CDB-2914
equivalents (129 +/- 24 ng/ml) occurred at 5 +/- 1 h, while the C(max) of
mifepristone equivalents (31 +/- 8 ng/ml) occurred at 3 +/- 1 h. The serum
concentration (AUC(0-120 h)) of CDB-2914 equivalents was 4.7- or 5. 3-fold
greater than that of mifepristone equivalents when administered orally in ASV or
gelatin capsules respectively. The serum protein binding characteristics of CDB
2914 were also studied. CDB-2914 bound to human alpha(1)-acid glycoprotein (AAG),
but not with as high an affinity as mifepristone. In contrast, neither CDB-2914
nor mifepristone bound with high affinity to AAG, corticosteroid binding globulin
or sex hormone binding globulin in monkey serum. Collectively, these results
indicated that CDB-2914 was more efficiently absorbed than mifepristone following
oral administration to female rhesus monkeys.
PMID- 10783359
TI - A single mid-follicular dose of CDB-2914, a new antiprogestin, inhibits
folliculogenesis and endometrial differentiation in normally cycling women.
AB - Previous studies in women have shown that the antiprogestin mifepristone delays
or inhibits folliculogenesis. The purpose of this study was to explore whether a
new analogue, CDB-2914, has similar effects on folliculogenesis, ovulation, or on
subsequent luteal phase endometrial maturation. Forty-four normally cycling,
healthy women recorded urine LH and vaginal bleeding during pre-treatment,
treatment, and post-treatment cycles. At a lead follicle diameter of 14-16 mm, a
single oral dose (10, 50, 100 mg) of CDB-2914 or placebo was given, and daily
ultrasound, oestradiol and progesterone were obtained until follicular collapse;
an endometrial biopsy was obtained 5-7 days later. Single doses of CDB-2914 were
well tolerated. Mid-follicular CDB-2914 suppressed lead follicle growth, causing
a dose-dependent delay in folliculogenesis and suppression of plasma oestradiol.
At higher doses, a new lead follicle was often recruited. Although luteinized
unruptured follicles were observed at the 100 mg dose, all women had follicular
collapse. There was a significant delay in endometrial maturation after CDB-2914
at all doses. The treatment cycle was lengthened by 1-2 weeks in 30% at 100, 27%
at 50 and 9% at 10 mg. CDB-2914 altered ovarian and endometrial physiology
without major effects on menstrual cyclicity and may have therapeutic utility.
PMID- 10783361
TI - Analysis of chromosomal abnormalities in human spermatozoa using multi-colour
fluorescence in-situ hybridization.
AB - There is concern that intracytoplasmic sperm injection (ICSI) may lead to
offspring with a high frequency of chromosomal abnormalities. Accordingly, we
studied spermatozoa sampled from eight infertile men with
oligoasthenoteratozoospermia (OAT) by multi-colour fluorescence in-situ
hybridization (FISH), using DNA probes for chromosomes 13, 18, 21, X and Y.
Results were compared with those of spermatozoa sampled from 10 healthy men with
normal semen profiles. Analysis of the diploidy values was repeated twice in each
of the 18 men. There was no significant difference in the two diploidy estimates;
thus the FISH technique appeared to be accurate and reliable for determining
aneuploidy in human spermatozoa. We found the average frequencies of disomy for
chromosomes 13, 18, 21 and X or Y to be 0.13, 0.12, 0.24 and 0.59% respectively
for the OAT group and 0.09, 0.13, 0.19 and 0.38% respectively for the control
group. The diploidy rate was 0.29% in the OAT group, and 0.16% in the control
group. Thus, the OAT group showed a significantly higher frequency of disomy for
chromosomes 13 (P < 0.001), 21 (P < 0.05), sex (P < 0.001), and diploidy (P <
0.005) than the control group. This finding suggests there may be some risk of
aneuploidy in the offspring conceived by the ICSI technique.
PMID- 10783362
TI - The use of two density gradient centrifugation techniques and the swim-up method
to separate spermatozoa with chromatin and nuclear DNA anomalies.
AB - Human semen is heterogeneous in quality, not only between males but also within a
single ejaculate. Differences in quality are evident, both when examining the
classical parameters of sperm number, motility and morphology and in the
integrity of the sperm nucleus. The aim of this study was to determine the
efficiency of the PureSperm((R)), Percoll((R)) and swim-up preparation techniques
to eliminate spermatozoa with nuclear anomalies. Semen samples were collected,
washed and one part of the semen spread on a slide, the remainder was prepared
using the swim-up, PureSperm((R)) or Percoll((R)) techniques. Spermatozoa from
different fractions were fixed on slides and assessed. Sperm samples (n) from
different men were stained using the chromomycin A(3) (CMA(3)) fluorochrome,
which indirectly demonstrates a decreased presence of protamine (n = 31 for swim
up; n = 45 for PureSperm((R)); n = 39 for Percoll((R))). Spermatozoa prepared
using PureSperm((R)) (n = 35) and Percoll((R)) (n = 37) were also examined for
the presence of endogenous DNA nicks. Good quality spermatozoa should not possess
DNA nicks and not stain (i.e. fluoresce) with CMA(3). When prepared using the
swim-up technique the spermatozoa recovered showed no significant improvement
with the CMA(3) staining. When spermatozoa were prepared using the PureSperm((R))
and Percoll((R)) techniques, a significant (P < 0.001) decrease in both CMA(3)
positivity and DNA strand breakage was observed. These results indicate that both
the PureSperm((R)) and Percoll((R)) techniques can enrich the sperm population by
separating out those with nicked DNA and with poorly condensed chromatin.
PMID- 10783363
TI - Enhancement of zona binding using 2-hydroxypropyl- beta-cyclodextrin.
AB - Since membrane cholesterol depletion is known to play an important role in sperm
capacitation, we have investigated the effect of 2-hydroxypropyl-beta
cyclodextrin, a cyclic oligosaccharide that mediates cholesterol efflux, on sperm
functions. Sperm treatment with cyclodextrin did not affect the motility patterns
but induced an increase in sperm binding to zona pellucida (24 +/- 5 versus 13 +/
4 in control, P < 0.01). Cyclodextrin treatment was associated with an increase
in spontaneous acrosome reaction (32 +/- 8% versus 22 +/- 4% in controls after a
4 h incubation, P < 0.05; 61 +/- 10% versus 50 +/- 11% in controls after a 24 h
incubation, NS) but with a decrease in acrosome response to ionophore challenge
(44 +/- 5% versus 51 +/- 3% in controls, P < 0.05). Concerning cell sterols,
cyclodextrin induced a rapid and dramatic fall in the cholesterol and desmosterol
content of spermatozoa. We conclude that cyclodextrin is a powerful capacitating
agent, but since it induces an increase in spontaneous acrosome loss, it needs to
be further evaluated before routine use in assisted reproductive technology
media.
PMID- 10783364
TI - Chromosome analysis of spermatozoa extracted from testes of men with non
obstructive azoospermia.
AB - Infertile men with azoospermia now have the possibility of fathering children by
testicular sperm extraction combined with intracytoplasmic sperm injection.
However, there are concerns about the risk of chromosomal abnormalities in their
spermatozoa. We have studied aneuploidy frequencies for chromosomes 13, 21, X and
Y by multicolour fluorescence in-situ hybridization (FISH) in testicular
spermatozoa extracted from three men with non-obstructive azoospermia. The men
were 34-37 years of age and had normal follicle-stimulating hormone (FSH)
concentrations and normal 46,XY somatic karyotypes. A total of 3324 spermatozoa
was analysed. The infertile patients had an elevated frequency of disomy for
chromosomes 13, 21, XY disomy compared to controls but none of these reached
statistical significance. Also there was no significant difference in the sex
ratio or the frequency of diploidy in azoospermic patients compared to normal
control donors. This first report on chromosomal aneuploidy in spermatozoa
extracted from testes of patients with non-obstructive azoospermia suggests that
some azoospermic men do not have a substantially increased risk of chromosomally
abnormal spermatozoa.
PMID- 10783365
TI - The effect of extracellular ice and cryoprotective agents on the water
permeability parameters of human sperm plasma membrane during freezing.
AB - A firm biophysical basis for the cryopreservation of human spermatozoa is limited
by a lack of knowledge regarding the water permeability characteristics during
freezing in the presence of extracellular ice and cryoprotective agents (CPA).
Cryomicroscopy cannot be used to measure dehydration during freezing in human
spermatozoa because of their highly non-spherical shape and their small
dimensions which are at the limits of light microscopic resolution. Using a new
shape-independent differential scanning calorimeter (DSC) technique, volumetric
shrinkage during freezing of human sperm cell suspensions was obtained at cooling
rates of 5 and 10 degrees C/min in the presence of extracellular ice and CPA.
Using previously published data, the human sperm cell was modelled as a cylinder
of length 40.2 micrometer and a radius of 0.42 micrometer with an osmotically
inactive cell volume, V(b), of 0.23V(o), where V(o) is the isotonic cell volume.
By fitting a model of water transport to the experimentally obtained volumetric
shrinkage data, the best fit membrane permeability parameters (L(pg) and E(Lp))
were determined. The 'combined best fit' membrane permeability parameters at 5
and 10 degrees C/min for human sperm cells in modified media are: L(pg) = 2.
4x10(-14) m(3)/Ns (0.14 micrometer/min-atm) and E(Lp) = 357.7 kJ/mol (85. 5
kcal/mol) (R(2) = 0.98), and in CPA media (with 6% glycerol and 10% egg yolk) are
L(pg)[cpa] = 0.67x10(-14) m(3)/Ns (0.04 micrometer/min-atm) and E(Lp)[cpa] =
138.9 kJ/mol (33.2 kcal/mol) (R(2) = 0.98). These parameters are significantly
different from previously published parameters for human spermatozoa obtained at
suprazero temperatures and at subzero temperatures in the absence of
extracellular ice. The parameters obtained in this study also suggest that
damaging intracellular ice formation (IIF) could occur in human sperm cells at
cooling rates as low as 25-45 degrees C/min, depending on the concentrations of
the CPA. This may help to explain the discrepancy between the empirically
determined optimal cryopreservation cooling rates (<100 degrees C/min) and the
numerically predicted optimal cooling rates (>7000 degrees C/min) obtained using
previously published suprazero human sperm permeability parameters which do not
account for the presence of extracellular ice.
PMID- 10783366
TI - Chromosome analysis of human spermatozoa from an oligoasthenozoospermic carrier
for a 13;14 Robertsonian translocation by their injection into mouse oocytes.
AB - We present a case of a 46,XY der(13;14) Robertsonian translocation carrier whose
spermatozoa were karyotyped after injection into mouse oocytes. Fresh semen
samples as well as recovered samples were used. There was no significant
difference in the survival rate of mouse oocytes (fresh: 78.1% versus frozen:
81.7%), activation rate (fresh: 84.0% versus frozen: 90.6%), fertilization rate
(fresh: 72.0% versus thawing of frozen: 76.5%) between fresh or frozen
spermatozoa. Metaphase chromosome spreads from 45 spermatozoa were analysed. The
frequency of spermatozoa that were chromosomally unbalanced with respect to the
translocation was 8.9%, and the frequency of abnormalities unrelated to
translocation was 4.4%. An excess of spermatozoa with balanced chromosomes was
observed: compared with normal, 23 (51.1%) versus 16 (35.6%) respectively; but
this segregation difference was not statistically significant (chi(2) = 0.9, P >
0.3). After genetic counselling with the carrier and his partner,
intracytoplasmic sperm injection treatment was performed. Healthy female and male
infants were delivered at 36 weeks gestation via a Caesarean section. Both babies
were carriers for the balanced Robertsonian translocations detected for prenatal
diagnosis at 16 weeks gestation. The present study demonstrates that patients can
be given further information about the proportion of the spermatozoa which carry
a chromosomal abnormality.
PMID- 10783367
TI - Effect of recombinant human gonadotrophins on human, bovine and murine oocyte
meiosis, fertilization and embryonic development in vitro.
AB - The response of murine, bovine and human oocytes to pure recombinant preparations
of human follicle stimulating hormone (rFSH) and luteinizing hormone (rLH) for
meiotic maturation and subsequent developmental competence in vitro were examined
in the present experiments. Maturation of immature bovine oocytes to the
metaphase II stage was significantly increased by the addition of 1 IU/ml of rFSH
in combination with either 1 IU/ml rLH or 10 IU/ml rLH. Similarly, embryonic
development to the blastocyst stage was improved in bovine oocytes treated with a
1:10 combination of rFSH:rLH. However, no significant difference was observed in
the number of inner cell mass or trophectoderm cells of the resulting
blastocysts. Although the increased maturation to metaphase II was not
significant, human embryonic developmental competence was improved by maturing
oocytes in the presence of a 1:10 ratio of rFSH:rLH as only those oocytes exposed
to a 1:10 ratio of rFSH: rLH during maturation showed normal cleavage patterns
beyond day 2. In addition, 1 IU/ml rFSH and 1 IU/ml rLH increased the expression
of oocyte proteins in human oocytes. The inclusion of recombinant gonadotrophins,
either singly or in combination, had no significant effect on the maturation,
fertilization or embryonic development of in-vitro matured mouse oocytes. These
data provide support for the responsiveness of human and bovine oocytes to
gonadotrophins in vitro and the need to consider variations in the relative
concentrations for optimization of oocyte developmental competence.
PMID- 10783368
TI - Chemically and mechanically induced membrane fusion: non-activating methods for
nuclear transfer in mature human oocytes.
AB - Most current studies of nuclear transfer in mammalian oocytes have used
electrofusion to incorporate donor cell nuclei into enucleated oocyte cytoplasts.
However, the application of electrofusion to human oocytes is hampered by the
relative ease with which this procedure induces oocyte activation. Here we tested
a previously described chemical fusion technique and an original mechanical
fusion procedure in this application. Enucleated metaphase II oocytes were first
agglutinated with karyoplasts originating from other metaphase II oocytes and
then induced to fuse with the use of polyethylene glycol or by micromanipulation
with an intracytoplasmic sperm injection (ICSI) micropipette. Both techniques
yielded a high frequency of fusion and did not cause oocyte activation. Moreover,
the reconstructed oocytes were easily activated by subsequent treatment with
ionophore A23187 and 6-dimethylaminopurine. These techniques may be used in
attempts to alleviate female infertility due to insufficiency of ooplasmic
factors by nuclear transfer from patients' oocytes to enucleated donor oocyte
cytoplasts. For eventual future use in human cloning, they would ensure prolonged
exposure of transferred nuclei to metaphase promoting factor, which appears to be
required for optimal nuclear reprogramming.
PMID- 10783369
TI - Hyaluronan in the nuchal skin of chromosomally abnormal fetuses.
AB - Nuchal skin oedema at 10-14 weeks gestation, observed by ultrasonography as
increased nuchal translucency (NT), is found in approximately 70% of fetuses with
trisomies 21, 18 and 13 as well as those with Turner's syndrome. This study
investigates the possibility that one mechanism for increased translucency is an
altered composition of the skin with a higher concentration of hyaluronan; large
amounts of hyaluronan can lead to excessive hydration of the extracellular
matrix. We isolated the hyaluronic acid binding region (HABR) from aggrecan in
the extracellular matrix of hyaline cartilage and used it in a biotinylated form
in combination with a fluorescent probe as a marker for hyaluronan.
Immunohistochemistry was then used to examine the nuchal skin of chromosomally
abnormal and normal fetuses, obtained after termination of pregnancy. In fetuses
with trisomy 21 there was a substantial increase in hyaluronan, whereas in
trisomies 18 and 13 and Turner's syndrome the amount was similar to that in
chromosomally normal controls. This finding suggests that hyaluronan may be
implicated in the pathogenesis of increased NT in fetuses with trisomy 21, but
the common phenotypic expression of increased translucency in different
chromosomal abnormalities may be the consequence of other mechanisms.
PMID- 10783370
TI - Vaginal misoprostol alone for medical abortion up to 9 weeks of gestation:
efficacy and acceptability.
AB - Misoprostol and mifepristone have been shown to be effective for medical abortion
up to 9 weeks of gestation. When used alone, the successful complete abortion
rate dropped to approximately 60%. It has been demonstrated that by adding water
to misoprostol, the success rate rose to 92%. This is the first randomized study
to investigate the efficacy of misoprostol and water versus misoprostol alone for
first trimester medical abortion in women at = 9 weeks of gestation. Eighty
women were randomly assigned to group 1 (water added to misoprostol) and group 2
(misoprostol alone). Vaginal misoprostol 800 microgram was given on days 1, 3 and
5. If the woman did not require vacuum aspiration during the period up to the
return of first menstruation after medical abortion, the outcome was classified
as complete abortion. The incidence of side-effects and the acceptability were
assessed through a standardized questionnaire during and after the abortion. The
complete abortion rate appeared higher when water was added but the difference
did not reach statistical significance. Gastro-intestinal side-effects were
common but well tolerated in both groups. Overall, 40% of the women preferred a
surgical method in the future because of the high failure rate. With an overall
complete abortion rate of 85%, it is probably not a clinically acceptable method
even if the addition of water can improve the results. We conclude that the
addition of water onto misoprostol tablets does not improve its efficacy in first
trimester medical abortion. Misoprostol alone is not recommended for medical
abortion (up to 9 weeks of pregnancy) because of the high failure rate and low
acceptability.
PMID- 10783371
TI - Peripheral natural killer cytotoxicity and CD56(pos)CD16(pos) cells increase
during early pregnancy in women with a history of recurrent spontaneous abortion.
AB - For diagnostic purposes we assessed peripheral natural killer (NK) cell
cytotoxicity and NK and T cell numbers to assess their putative predictive value
in recurrent spontaneous abortion (RSA). A total of 43 women with subsequent
pregnancy, 37 healthy controls and 39 women successfully partaking in an in-vitro
fertilization (IVF) procedure, were included in the study. We show that before
pregnancy, levels of NK cytotoxicity and numbers of both single CD56(pos) and
double CD56(pos)CD16(pos) cells were similar between RSA women and controls. But
notably, within the RSA group, NK cell numbers of <12% were strongly associated
with a subsequent pregnancy carried to term. Supplementation of folic acid led to
an increase of single CD56(pos) cells, but cytotoxic function appeared
unaffected. The expression pattern of killer inhibitory receptors on CD56(pos)
cells was not different between patients and controls. A longitudinal study
revealed that, compared with controls, in RSA women higher numbers of double
CD56(pos)CD16(pos) cells were present during early pregnancy, paralleled by an
increase in cytotoxic NK cell reactivity. The single CD56(pos) population
decreased in number. In conclusion, the analysis of peripheral NK cell
characteristics appears a suitable diagnostic tool in RSA. Immunomodulation aimed
at NK cell function appears a promising therapeutic measure.
PMID- 10783372
TI - Anti-cardiolipin antibodies in fetal blood and amniotic fluid derived from
patients with the anti-phospholipid syndrome.
AB - The aim of this study was to investigate whether, in patients with
antiphospholipid syndrome, anticardiolipin antibodies pass from mother to
offspring sera and amniotic fluid. Eleven patients with antiphospholipid syndrome
(study group) and 11 healthy controls, matched by maternal and gestational age
(control group) were prospectively examined for the presence of anticardiolipin
antibodies in the cord blood during labour, and amniotic fluid during vaginal or
Caesarean delivery. Three neonates (27.3%) in the study group had anticardiolipin
antibodies in the cord blood, while none had them in the control group.
Anticardiolipin antibodies were detected in the amniotic fluid in six (54.5%) of
the study group pregnancies, compared with none in the control group. No adverse
neonatal outcome was noted except for significantly lower (P < 0.0006) mean birth
weight in the study group. Anticardiolipin antibodies can pass the placenta and
be detected in fetal cord blood and amniotic fluid. This finding might be used in
the future for the assessment of pregnancies with antiphospholipid syndrome.
PMID- 10783373
TI - Fertility outcome after ectopic pregnancy and use of an intrauterine device at
the time of the index ectopic pregnancy.
AB - Fertility after ectopic pregnancy (EP) was investigated in a non-selected
population taking into account intrauterine device (IUD) use at the time of the
EP. Between January 1992 and June 1996, 647 women listed in the EP register of
Auvergne (France) were followed up. The analysis included only the 328 women who
were seeking to become pregnant: 23 women using IUD at the time of the index EP
(IUD users) and 305 IUD non-users. Among IUD users, there was no recurrence of
EP, and the 1 year cumulative rate was 87% [95% confidence interval (CI): 73
100%] for intrauterine pregnancies and 86% (95% CI: 72-100%) for deliveries.
Among IUD non-users, the 2 year cumulative rate for recurrence of EP was 28% (95%
CI: 17-39%), and the 1 year cumulative rates were 60% (95% CI: 53-66%) for
intrauterine pregnancies and 44% (95% CI: 38-56%) for deliveries. The adjusted
intrauterine pregnancy rate of IUD users was not significantly different from
that of IUD non-users. However, IUD non-users had more miscarriages, so their
delivery rate was lower.
PMID- 10783374
TI - Secular movements in sex ratios of adults and of births in populations during the
past half-century.
AB - There is some evidence for a small overall negative correlation across
populations between sex ratio (proportion male) at birth and adult sex ratio.
There seems to be no systematic correlation within populations across time of sex
ratio at birth with adult sex ratio during the past 50 years. So even if adult
sex ratios play some part in determining the overall level of the sex ratio at
birth, they apparently have played little role in the recent widespread secular
changes in sex ratio at birth. It is shown here that there is a strong cohort
effect in adult sex ratios: if a woman is in a marriage squeeze (i.e. in a cohort
with a relative abundance of women) at age 15 years, she will remain in such a
squeeze for the rest of her reproductive life. In England and Wales, the maternal
age-specific sex ratios at birth moved roughly in parallel across time during the
years 1950-1995. This suggests that sex ratio at birth is not a cohort phenomenon
(as it would be if it were affected by adult sex ratio) but is subject to some
agents which change with time and affect women (parents) of all ages roughly
equally.
PMID- 10783375
TI - The variation of the probability of a son within and across couples.
AB - It is suggested that there is a flaw in the currently accepted account of the
variation of P, the probability of a boy, within and across couples. It was
previously suggested that P has a mean (for Caucasian couples) of approximately
0.514 with an SD of approximately 0.05 across couples: and that the variation
within couples is rather less. Grounds are offered here for suspecting that this
formulation underestimates both SDs by a factor of as much as 4. It is suggested
that in estimating these sources of variation, earlier workers did not consider
the possibility that within-couple variation might be random and substantial. In
view of the established epidemiology of human sex ratios, it now seems likely
that such variation exists, and that there is a substantial measure of
counterbalancing across-couple variation.
PMID- 10783376
TI - Obstetric outcome of pregnancies following ICSI, classified according to sperm
origin and quality.
AB - The aim of this study was to report the outcome of all clinical pregnancies
obtained after intracytoplasmic sperm injection (ICSI) performed during a 5 year
period at two fertility clinics, with special reference to delivery outcome
associated with different sperm origin and quality and the transfer of fresh or
frozen-thawed pre-embryos. A total of 1293 clinical pregnancies was analysed.
Deliveries occurred in 75.9% (n = 982) and early spontaneous abortion, late
spontaneous abortion and ectopic pregnancy in 21.4, 1.0 and 1.2% respectively.
Multiple birth occurred in 21.3% (208 sets of twins and one set of triplets) of
the deliveries, with the highest incidence in the epididymal sperm group (30.2%)
and lowest in the cryopreserved group (13.7%). A total of 1192 infants was born.
Preterm birth occurred in 15.7% of all deliveries. Preterm birth was not related
to sperm origin or quality but was related to multiple birth. The prematurity
rate was 8.4%, 42.3% and 100% for singletons, twins and triplets respectively.
Singleton infants born after cryopreservation as embryos had a significantly
higher birthweight than the ejaculated sperm group with fresh embryo transfer.
The perinatal mortality rate was 11.7 per 1000 born infants. Eighty-seven of the
1192 infants (7.3%) had a malformation, 40 of which were minor. The perinatal
mortality rate and the malformation rate were similar in the different subgroups.
Prenatal karyotyping was performed on 149 fetuses (12.5%) and abnormal results
were found in four cases (2.7%). In conclusion, obstetric outcome of ICSI
pregnancies was similar to that of conventional IVF and was not influenced by
sperm origin or quality. The high incidence of multiple births is still the major
concern.
PMID- 10783377
TI - Pemphigus vulgaris in pregnancy: a case report and review of literature.
AB - Pemphigus vulgaris (PV) is an uncommon, immune-mediated bullous dermatosis,
which, during its active phase, has been associated with infertility. Pemphigus
vulgaris during pregnancy is exceedingly rare-only 26 cases with
immunopathological confirmation have been reported. The disease may be associated
with adverse neonatal outcome, including prematurity and fetal death. Transient
skin lesions may occasionally appear in the neonate. We report a patient who
conceived during the active phase of PV, required high doses of corticosteroids
to control the disease, and was delivered of a pre-term, appropriate-for
gestational age newborn.
PMID- 10783378
TI - Posterior uterine wall rupture during labour.
AB - Vaginal births after Caesarean section (VBAC) are well-accepted procedures when
pregnant women do not have any contra-indications. The possibilities of the
uterine dehisence and rupture during VBAC should always be considered. This
occurrence is usually related to the previous scar tissue and subsequent risk is
acceptable. Nevertheless, rupture that occurs in presumably normal tissue areas
of the uterus instead of in scar tissue areas with resultant perinatal death is
extremely rare. We present a 31 year old woman who had posterior uterine rupture
when she tried VBAC at 38 weeks gestation. During the course of VBAC, she had a
smooth labour course without use of any augmentation medication, but her
condition was complicated with uterine rupture without any premonitory signal. It
resulted in maternal shock and sequentially the death of the newborn 7 days after
delivery. By reviewing this case report, we should keep in mind that prompt
response to every woman during labour is of paramount importance to avoid
repeating the occurrence of uterine rupture, partly because uterine rupture could
occur without prominent signals and partly because subsequent dangers seem to be
those created by acts of omission. Finally, the benefits and safety of VBAC have
not been undermined because this patient is an isolated and extremely rare case.
PMID- 10783380
TI - The need for statistical rigour when pooling data from a variety of sources.
PMID- 10783379
TI - Equal distribution of congenital blood cell chimerism in dizygotic triplets after
in-vitro fertilization.
AB - The special situation of multiple pregnancies following IVF has led to a growing
interest in the assessment of embryonal development by means of molecular
genetics. We report a case of congenital blood chimerism in dizygotic triplets
(two boys, one girl) present in erythrocytes and leukocytes in both sexes.
Routine pre-operative blood serology of the 6 year old female triplet revealed
chimerism of the red cells. Flow cytometry of the erythrocytes and DNA analysis
of the leukocytes demonstrated that all three children had the same proportions
of male and female cells. Fluorescent in-situ hybridization (FISH) analyses
revealed Y chromosomes in 84% of the girl's leukocytes and in 89/92% of the two
boys' leukocytes. The true genetic lines were determined by analysing
polymorphism of serum groups (glycoprotein, transferrin, protease inhibitor and
plasminogen) secreted by non-haematopoetic tissue, by blood group typing of hair
roots and by DNA analysis of endothelial cells. Evidently placental anastomoses
allowed a reciprocal intra-uterine transfusion of blood stem cells in the
triplets.
PMID- 10783382
TI - Should hysteroscopy be a part of the basic infertility workup?
PMID- 10783381
TI - Analysing data on the sex ratio of human births by cycle day of conception.
PMID- 10783383
TI - Recombinant versus urinary FSH for ovarian stimulation in assisted reproduction.
PMID- 10783384
TI - Abnormal sodium stimulation of carnitine transport in primary carnitine
deficiency.
AB - Primary carnitine deficiency is an autosomal recessive disorder of fatty acid
oxidation characterized by hypoketotic hypoglycemia and skeletal and cardiac
myopathy. It is caused by mutations in the sodium-dependent carnitine
cotransporter OCTN2. The majority of natural mutations identified in this and
other Na(+)/solute symporters introduce premature termination codons or impair
insertion of the mutant transporter on the plasma membrane. Here we report that a
missense mutation (E452K) identified in one patient with primary carnitine
deficiency did not affect membrane targeting, as assessed with confocal
microscopy of transporters tagged with the green fluorescent protein, but reduced
carnitine transport by impairing sodium stimulation of carnitine transport. The
natural mutation increased the concentration of sodium required to half-maximally
stimulate carnitine transport (K(Na)) from the physiological value of 11.6 to 187
mm. Substitution of Glu(452) with glutamine (E452Q), aspartate (E452D), or
alanine (E452A) caused intermediate increases in the K(Na). Carnitine transport
decreased exponentially with increased K(Na). The E452K mutation is the first
natural mutation in a mammalian cotransporter affecting sodium-coupled solute
transfer and identifies a novel domain of the OCTN2 cotransporter involved in
transmembrane sodium/solute transfer.
PMID- 10783385
TI - Specific cellular proteins associate with angiotensin-converting enzyme and
regulate its intracellular transport and cleavage-secretion.
AB - Angiotensin-converting enzyme (ACE) is an extensively glycosylated type I
ectoprotein anchored in the plasma membrane by a hydrophobic transmembrane
domain. In tissue culture as well as in vivo, the extracellular domain of ACE is
released into the culture medium by a regulated proteolytic cleavage. To identify
the cellular proteins that regulate ACE processing and cleavage-secretion, ACE
bound proteins were purified by affinity chromatography and characterized by
microsequencing and Western blotting. One protein was identified as ribophorin
and another as immunoglobulin-binding protein (BiP), a chaperone. Metabolic
labeling and immunoprecipitation of ACE confirmed its interaction with BiP.
Overexpression of BiP inhibited ACE secretion, an effect accentuated by the
expression of an enzymatically inactive mutant BiP. This inhibition was caused by
the retention of ACE precursors by BiP in the endoplasmic reticulum, as revealed
by immunoprecipitation and immunofluorescence experiments. However, treatment
with a phorbol ester, phorbol 12-myristate 13-acetate, enhanced ACE secretion
even from cells overexpressing BiP. Western blot analysis of ACE-associated
proteins with antibodies to protein kinase C (PKC) revealed the presence of its
specific isozymes. Treatment with phorbol 12-myristate 13-acetate caused marked
reduction in ACE association of selective PKC species. Thus, our studies have
identified PKC and BiP as two proteins that directly interact with ACE and
modulate its cell-surface expression and cleavage-secretion.
PMID- 10783386
TI - Cyclic GMP-dependent protein kinase signaling pathway inhibits RhoA-induced Ca2+
sensitization of contraction in vascular smooth muscle.
AB - The potent vasodilator action of cyclic GMP-dependent protein kinase (cGK)
involves decreasing the Ca(2+) sensitivity of contraction of smooth muscle via
stimulation of myosin light chain phosphatase through unknown mechanisms (Wu, X.,
Somlyo, A. V., and Somlyo, A. P. (1996) Biochem. Biophys. Res. Commun. 220, 658
663). Myosin light chain phosphatase activity is controlled by the small GTPase
RhoA and its target Rho kinase. Here we demonstrate cGMP effects mediated by cGK
that inhibit RhoA-dependent Ca(2+) sensitization of contraction of blood vessels
and actin cytoskeleton organization in cultured vascular myocytes. Ca(2+)
sensitization and actin organization were inhibited by both 8-bromo-cGMP and
sodium nitroprusside (SNP). SNP also caused translocation of activated RhoA from
the membrane to the cytosol. SNP-induced actin disassembly was lost in vascular
myocytes in culture after successive passages but was restored by transfection of
cells with cGK I. Furthermore, cGK phosphorylated RhoA in vitro, and addition of
cGK I inhibited RhoA-induced Ca(2+) sensitization in permeabilized smooth muscle.
8-Bromo-cGMP-induced actin disassembly was inhibited in vascular myocytes
expressing RhoA(Ala-188), a mutant that could not be phosphorylated.
Collectively, these results indicate that cGK phosphorylates and inhibits RhoA
and suggest that the consequent inhibition of RhoA-induced Ca(2+) sensitization
and actin cytoskeleton organization contributes to the vasodilator action of
nitric oxide.
PMID- 10783387
TI - Analysis of the HypC-hycE complex, a key intermediate in the assembly of the
metal center of the Escherichia coli hydrogenase 3.
AB - The formation of a complex between the specific chaperone-type protein HypC and
the precursor form of the large subunit HycE in the maturation pathway of
hydrogenase 3 from Escherichia coli has been studied by targeted replacement of
amino acids in both proteins. HypC and its homologs contain the motif
MC(L/I/V)(G/A)(L/I/V)P at the amino terminus, from which the methionine residue
is post-translationally removed. The exchange of the cysteine residue led to
complete loss of the ability to interact with the precursor form of HycE, but
replacement of the proline residue had no effect. Site-directed replacement of
the conserved cysteine residues in HycE involved in nickel binding was also
performed. Exchange of Cys(241) resulted in the inability of the HycE variant to
interact with HypC and to incorporate nickel. The variants of HycE in which
Cys(244) and Cys(531) were replaced by alanine residues were unable to
incorporate nickel, although the mutated proteins could interact with HypC.
Intriguingly, the precursor of HycE in which the Cys(534) residue was exchanged
could form the complex with HypC, could incorporate nickel, and was C-terminally
processed, but it delivered an inactive enzyme. Our findings are in favor of a
model in which binding of HypC masks Cys(241); Cys(244) and Cys(531) bind the
iron and nickel moieties, respectively; and C534 closes the bridge between the
two metals after C-terminal processing has taken place.
PMID- 10783388
TI - Activation of p38 mitogen-activated protein kinase is required for tumor necrosis
factor-alpha -supported proliferation of leukemia and lymphoma cell lines.
AB - To elucidate mechanisms of tumor necrosis factor alpha (TNF-alpha)-induced
proliferation of a number of human leukemia and lymphoma cell lines, we examined
the role of p38 mitogen-activated protein kinase (MAPK) in TNF-alpha signaling in
Mo7e and Hut-78 cells. TNF-alpha-dependent p38 MAPK activation was detected in
both Mo7e and Hut-78 cells and was blocked by the p38 MAPK inhibitor, SB203580.
Ablation of p38 MAPK activity by SB203580 abrogated TNF-alpha-induced Mo7e cell
proliferation and TNF-alpha-dependent autocrine growth of Hut-78. As we have
shown previously that activation of the nuclear factor kappaB (NF-kappaB) is also
required for TNF-alpha-induced Mo7e cell proliferation, the involvement of p38
MAPK in NF-kappaB activation was assessed. SB203580 did not affect TNF-alpha
signaled nuclear translocation and DNA-binding activity of NF-kappaB, and
inhibition of NF-kappaB function did not affect TNF-alpha-induced p38 MAPK
activation, indicating that these events are not dependent on each other.
However, SB203580 depressed the expression of NF-kappaB-dependent genes, as
monitored by a kappaB-driven reporter gene. Our findings demonstrate that
activation of both p38 MAPK and NF-kappaB plays a critical role in TNF-alpha
mediated survival and proliferation of human leukemia and lymphoma cells, and p38
MAPK acts at least in part by facilitating the transcriptional activation
function of NF-kappaB.
PMID- 10783389
TI - Identification of neuromedin U as the cognate ligand of the orphan G protein
coupled receptor FM-3.
AB - Neuromedin U is a bioactive peptide first isolated from porcine spinal cord. In
this paper, we demonstrate that neuromedin U is the cognate ligand for the orphan
G protein-coupled receptor, FM-3, isolated originally as a homologue of
neurotensin and growth hormone secretogogue receptors. Neuromedin U induced
specific and evident elevation of extracellular acidification rates, arachidonic
acid metabolite release, and intracellular Ca(2+) mobilization in Chinese hamster
ovary cells expressing human FM-3. In addition, radiolabeled neuromedin U
specifically bound to membrane fractions prepared from these cells with high
affinity. We subsequently analyzed the tissue distribution of neuromedin U and FM
3 mRNAs in rats using quantitative reverse transcription-polymerase chain
reaction. Neuromedin U mRNA was highly expressed in the gastrointestinal tract,
and the highest expression was detected in the pituitary gland. On the other
hand, FM-3 mRNA was highly expressed in the small intestine and lung, suggesting
that neuromedin U plays important roles in these tissues. The identification of a
specific and functional receptor for neuromedin U will facilitate studies on
their physiological roles and the search for receptor agonists and antagonists.
PMID- 10783390
TI - RGS4 is arginylated and degraded by the N-end rule pathway in vitro.
AB - The N-end rule relates the in vivo half-life of a protein to the identity of its
N-terminal residue. We used an expression-cloning screen to search for mouse
proteins that are degraded by the ubiquitin/proteasome-dependent N-end rule
pathway in a reticulocyte lysate. One substrate thus identified was RGS4, a
member of the RGS family of GTPase-activating proteins that down-regulate
specific G proteins. A determinant of the RGS4 degradation signal (degron) was
located at the N terminus of RGS4, because converting cysteine 2 to either
glycine, alanine, or valine completely stabilized RGS4. Radiochemical sequencing
indicated that the N-terminal methionine of the lysate-produced RGS4 was replaced
with arginine. Since N-terminal arginine is a destabilizing residue not encoded
by RGS4 mRNA, we conclude that the degron of RGS4 is generated through the
removal of N-terminal methionine and enzymatic arginylation of the resulting N
terminal cysteine. RGS16, another member of the RGS family, was also found to be
an N-end rule substrate. RGS4 that was transiently expressed in mouse L cells was
short-lived in these cells. However, the targeting of RGS4 for degradation in
this in vivo setting involved primarily another degron, because N-terminal
variants of RGS4 that were stable in reticulocyte lysate remained unstable in L
cells.
PMID- 10783391
TI - Identification, characterization, and crystal structure of the Omega class
glutathione transferases.
AB - A new class of glutathione transferases has been discovered by analysis of the
expressed sequence tag data base and sequence alignment. Glutathione S
transferases (GSTs) of the new class, named Omega, exist in several mammalian
species and Caenorhabditis elegans. In humans, GSTO 1-1 is expressed in most
tissues and exhibits glutathione-dependent thiol transferase and dehydroascorbate
reductase activities characteristic of the glutaredoxins. The structure of GSTO 1
1 has been determined at 2.0-A resolution and has a characteristic GST fold
(Protein Data Bank entry code ). The Omega class GSTs exhibit an unusual N
terminal extension that abuts the C terminus to form a novel structural unit.
Unlike other mammalian GSTs, GSTO 1-1 appears to have an active site cysteine
that can form a disulfide bond with glutathione.
PMID- 10783392
TI - Multimeric structure of PomA, a component of the Na+-driven polar flagellar motor
of vibrio alginolyticus.
AB - Four integral membrane proteins, PomA, PomB, MotX, and MotY, are thought to be
directly involved in torque generation of the Na(+)-driven polar flagellar motor
of Vibrio alginolyticus. Our previous study showed that PomA and PomB form a
complex, which catalyzes sodium influx in response to a potassium diffusion
potential. PomA forms a stable dimer when expressed in a PomB null mutant. To
explore the possible functional dependence of PomA domains in adjacent subunits,
we prepared a series of PomA dimer fusions containing different combinations of
wild-type or mutant subunits. Introduction of the mutation P199L, which
completely inactivates flagellar rotation, into either the first or the second
half of the dimer abolished motility. The P199L mutation in monomeric PomA also
altered the PomA-PomB interaction. PomA dimer with the P199L mutation even in one
subunit also had no ability to interact with PomB, indicating that the both
subunits in the dimer are required for the functional interaction between PomA
and PomB. Flagellar rotation by wild-type PomA dimer was completely inactivated
by phenamil, a sodium channel blocker. However, activity was retained in the
presence of phenamil when either half of the dimer was replaced with a phenamil
resistant subunit, indicating that both subunits must bind phenamil for motility
to be fully inhibited. These observations demonstrate that both halves of the
PomA dimer function together to generate the torque for flagellar rotation.
PMID- 10783393
TI - Cloning of a novel inosine-guanosine transporter gene from Leishmania donovani by
functional rescue of a transport-deficient mutant.
AB - Purine transport is an indispensable nutritional function for protozoan
parasites, since they are incapable of purine biosynthesis and must, therefore,
acquire purines from the host milieu. Exploiting a mutant cell line (FBD5) of
Leishmania donovani deficient in inosine and guanosine transport activity, the
gene encoding this transporter (LdNT2) has been cloned by functional rescue of
the mutant phenotype. LdNT2 encodes a polypeptide of 499 amino acids that shows
substantial homology to other members of the equilibrative nucleoside transporter
family. Molecular analysis revealed that LdNT2 is present as a single gene copy
within the leishmanial genome and encodes a single transcript of 3 kilobase
pairs. Transfection of FBD5 parasites with LdNT2 re-established their ability to
take up inosine and guanosine with a concurrent restoration of sensitivity to the
inosine analog formycin B. Kinetic analyses reveal that LdNT2 is highly specific
for inosine (K(m) = 0.3 micrometer) and guanosine (K(m) = 1.7 micrometer) and
does not recognize other naturally occurring nucleosides. Expression of LdNT2
cRNA in Xenopus oocytes significantly augmented their ability to take up inosine
and guanosine, establishing that LdNT2 by itself suffices to mediate nucleoside
transport. These results authenticate genetically and biochemically that LdNT2 is
a novel nucleoside transporter with an unusual and strict specificity for inosine
and guanosine.
PMID- 10783395
TI - Suppression of erythroid but not megakaryocytic differentiation of human K562
erythroleukemic cells by notch-1.
AB - The Notch signal transduction pathway is a highly conserved regulatory system
that controls multiple developmental processes. We have established an
erythroleukemia cell model to study how Notch regulates cell fate and
erythroleukemic cell differentiation. K562 and HEL cells expressed the Notch-1
receptor and the Notch ligand Jagged-1. The stable expression of the
constitutively active intracellular domain of Notch-1 (NIC-1) in K562 cells
inhibited erythroid without affecting megakaryocytic maturation. Expression of
antisense Notch-1 induced spontaneous erythroid maturation. Suppression of
erythroid maturation by NIC-1 did not result from down-regulation of GATA-1 and
TAL-1, transcription factors necessary for erythroid differentiation. Microarray
gene expression analysis identified genes activated during erythroid maturation,
and NIC-1 disrupted the maturation-dependent changes in the expression of these
genes. These results show that NIC-1 alters the pattern of gene expression in
K562 cells leading to a block in erythroid maturation and therefore suggest that
Notch signaling may control the developmental potential of normal and malignant
erythroid progenitor cells.
PMID- 10783394
TI - Activation of potassium and chloride channels by tumor necrosis factor alpha.
Role in liver cell death.
AB - Despite abundant evidence for changes in mitochondrial membrane permeability in
tumor necrosis factor (TNF)-mediated cell death, the role of plasma membrane ion
channels in this process remains unclear. These studies examine the influence of
TNF on ion channel opening and death in a model rat liver cell line (HTC). TNF
(25 ng/ml) elicited a 2- and 5-fold increase in K(+) and Cl(-) currents,
respectively, in HTC cells. These increases occurred within 5-10 min after TNF
exposure and were inhibited either by K(+) or Cl(-) substitution or by K(+)
channel blockers (Ba(2+), quinine, 0.1 mm each) or Cl(-) channel blockers (10
microm 5-nitro-2-(3-phenylpropylamino)benzoic acid and 0.1 mm N-phenylanthranilic
acid), respectively. TNF-mediated increases in K(+) and Cl(-) currents were each
inhibited by intracellular Ca(2+) chelation (5 mm EGTA), ATP depletion (4
units/ml apyrase), and the protein kinase C (PKC) inhibitors chelerythrine (10
micrometer) or PKC 19-36 peptide (1 micrometer). In contrast, currents were not
attenuated by the calmodulin kinase II 281-309 peptide (10 micrometer), an
inhibitor of calmodulin kinase II. In the presence of actinomycin D (1
micrometer), each of the above ion channel blockers significantly delayed the
progression to TNF-mediated cell death. Collectively, these data suggest that
activation of K(+) and Cl(-) channels is an early response to TNF signaling and
that channel opening is Ca(2+)- and PKC-dependent. Our findings further suggest
that K(+) and Cl(-) channels participate in pathways leading to TNF-mediated cell
death and thus represent potential therapeutic targets to attenuate liver injury
from TNF.
PMID- 10783396
TI - The transcription factor EGR-1 directly transactivates the fibronectin gene and
enhances attachment of human glioblastoma cell line U251.
AB - EGR-1, a transcription factor with important functions in the regulation of
growth and differentiation, is highly expressed in brain. Previous studies have
shown that EGR-1 suppresses the transformed phenotype. However, the expression
and role of EGR-1 in human glioblastoma cells are not yet determined. In this
study, we found that the basal expression of the EGR-1 protein is undetectable,
but is inducible in four human glioblastoma cell lines. To determine EGR-1
functions, we re-expressed EGR-1 in human glioblastoma U251 cells and found that
the secretion of transforming growth factor-beta1 (TGF-beta1), plasminogen
activator inhibitor-1 (PAI-1), and fibronectin (FN) was greatly enhanced.
Addition of anti-TGF-beta antibodies completely inhibited the secretion of PAI-1,
but had little effect on secretion of FN, indicating that PAI-1 is under the
control of EGR-1-induced TGF-beta1. An examination of the promoter of the FN gene
revealed two EGR-1-binding sites between positions -75 and -52 and positions -4
and +14 that specifically bound EGR-1 in gel mobility shift experiments.
Utilizing wild-type and mutant FN promoter/luciferase reporter genes, we
demonstrated that EGR-1 positively regulated the activity of the FN gene. In
addition, cell adhesion and migration were greatly increased in the EGR-1
expressing cells, and adhesion was reversed by addition of RGD-containing
peptides. These results suggest that EGR-1 may regulate cell interaction with the
extracellular matrix by coordinated induction of TGF-beta1, FN, and PAI-1 in
human glioblastoma cells.
PMID- 10783397
TI - A new determinant of endoplasmic reticulum localization is contained in the
juxtamembrane region of the ectodomain of hepatitis C virus glycoprotein E1.
AB - Hepatitis C virus glycoproteins E1 and E2 do not reach the plasma membrane of the
cell but accumulate intracellularly, mostly in the endoplasmic reticulum.
Previous studies based on transient expression assays have shown that the
transmembrane domains of both glycoproteins are sufficient to localize reporter
proteins in the endoplasmic reticulum and that other localization signals may be
contained in the ectodomain of E1 protein. To identify such signals we generated
chimeric proteins between E1 and two reporter proteins, the human CD8
glycoprotein and the human alkaline phosphatase, and analyzed their subcellular
localization in stable as well as transient transfectants. Our results showed
that (i) an independent localization determinant for the endoplasmic reticulum is
present in the juxtamembrane region of the ectodomain of E1 protein and (ii) the
localization dictated by this determinant is either due to direct retention or to
a recycling mechanism from the intermediate compartment/cis-Golgi complex region,
which is clearly different from those previously described for other retrieval
signals. These results show for the first time in mammalian cells that the
localization in the endoplasmic reticulum of transmembrane protein can be
determined by specific targeting signals acting in the lumen of the compartment.
PMID- 10783398
TI - Identification of a 24 kDa phosphoprotein associated with an intermediate stage
of memory in Hermissenda.
AB - A requirement for protein synthesis is a critical feature in dissociating
different phases of memory. However, in examples of cellular and synaptic
plasticity in which an early or intermediate requirement for protein synthesis
has been implicated, specific proteins have not been identified. Here we report
the identification of a 24 kDa phosphoprotein (CSP24) associated with an
intermediate stage of memory, distinct from short-term memory, detected after one
trial conditioning of Hermissenda. CSP24, initially identified from (32)PO(4)
labeled proteins resolved by two dimensional (2-D) PAGE, was excised from
multiple Coomassie blue-stained 2-D gels and subjected to reverse phase HPLC and
automated sequence analysis. The sequenced peptides exhibited a homology to the
beta-thymosin family of actin-binding protein. Anti-CSP24 antibody recognized
CSP24 on 1- and 2-D gels by Western blot analysis. Labeled CSP24
immunoprecipitated with anti-CSP24 antibody revealed that significantly more
(32)PO(4) was incorporated in preparations that received one-trial conditioning
compared with unpaired controls. In contrast, labeled CSP24 immunoprecipitated
with anti-CSP24 from conditioned and unpaired control preparations receiving a
procedure that only produced short-term enhanced excitability did not exhibit
differences in (32)PO(4) incorporation into the immunoprecipitates. These results
show that a specific identified phosphoprotein is associated with an intermediate
stage of memory for one-trial conditioning in Hermissenda.
PMID- 10783399
TI - High ethanol consumption and low sensitivity to ethanol-induced sedation in
protein kinase A-mutant mice.
AB - Both in vitro and in vivo evidence indicate that cAMP-dependent protein kinase
(PKA) mediates some of the acute and chronic cellular responses to alcohol.
However, it is unclear whether PKA regulates voluntary alcohol consumption. We
therefore studied alcohol consumption by mice that completely lack the regulatory
IIbeta (RIIbeta) subunit of PKA as a result of targeted gene disruption. Here we
report that RIIbeta knockout mice (RIIbeta-/-) showed incr eased consumption of
solutions containing 6, 10, and 20% (v/v) ethanol when compared with wild-type
mice (RIIbeta+/+). On the other hand, RIIbeta-/- mice showed normal consumption
of solutions containing either sucrose or quinine. When compared with wild-type
mice, the RIIbeta-/- mice were found to be less sensitive to the sedative effects
of ethanol as measured by more rapid recovery from ethanol-induced sleep, even
though plasma ethanol concentrations did not differ significantly from those of
controls. Finally, both RIbeta- and catylatic subunit beta1-deficient mice showed
normal voluntary consumption of ethanol, indicating that increased ethanol
consumption is not a general characteristic associated with deletion of PKA
subunits. These data demonstrate a role for the RIIbeta subunit of PKA in
regulating voluntary consumption of alcohol and sensitivity to the intoxication
effects that are produced by this drug.
PMID- 10783400
TI - Chemical stimulation of synaptosomes modulates alpha -Ca2+/calmodulin-dependent
protein kinase II mRNA association to polysomes.
AB - The presence of specific mRNAs in dendrites and at synapses is well established,
but a direct and reliable demonstration that they are associated with polysomes
is still missing. To address this point we analyzed the polysomal association of
the mRNAs for the alpha-subunit of Ca(2+)/calmodulin-dependent protein kinase II
(alpha-CaMKII), for type 1 inositol 1,4,5-trisphosphate receptor (InsP3R1) and
for the activity-regulated cytoskeleton-associated protein (Arc) in a
synaptosomal preparation devoid of contaminating material from neuronal and glial
perikarya. We show that a fraction of alpha-CaMKII, InsP3R1, and Arc mRNAs
present in synaptosomes is indeed associated with polysomes. Moreover, we show
that polysomal association of alpha-CaMKII mRNA, but not InsP3R1 and Arc mRNAs,
increases with depolarization of the synaptosomal membrane. Finally, we show that
the synthesis of alpha-CaMKII protein increases with stimulation. Dendritic mRNA
recruitment onto polysomes in response to synaptic stimulation might represent
one of the mechanisms underlying the processes of learning and memory.
PMID- 10783401
TI - Cervical dorsal rhizotomy increases brain-derived neurotrophic factor and
neurotrophin-3 expression in the ventral spinal cord.
AB - Although neurotrophic factors have been implicated in several forms of
neuroplasticity, little is known concerning their potential role in spinal
plasticity. Cervical dorsal rhizotomy (CDR) enhances serotonin terminal density
near (spinal) phrenic motoneurons and serotonin-dependent long-term facilitation
of phrenic motor output (Kinkead et al., 1998). We tested the hypothesis that
selected neurotrophic factors change in a manner consistent with an involvement
in this model of spinal plasticity. Brain-derived neurotrophic factor (BDNF),
neurotrophin-3 (NT-3), glial cell line-derived neurotrophic factor (GDNF), and
transforming growth factor-beta(1) (TGF-beta(1)) concentrations were measured
(ELISA) in three regions of interest to respiratory control: (1) ventral cervical
spinal segments associated with the phrenic motor nucleus (C3-C6), (2) ventral
thoracic spinal segments associated with inspiratory intercostal motor output (T3
T6) and (3) the diaphragm. Tissues were harvested from rats 7 d after bilateral
CDR and compared with sham-operated and unoperated control rats. CDR increased
BDNF (110%; p = 0.002) and NT-3 (100%; p = 0.002) in the cervical and NT-3 in the
thoracic spinal cord (98%; p = 0.009). GDNF and TGF-beta(1) were not altered by
CDR in any tissue. Immunohistochemistry localized BDNF and NT-3 to motoneurons
and interneurons of the ventral spinal cord. These studies provide novel,
suggestive evidence that BDNF and NT-3, possibly through their trophic effects on
serotonergic neurons and/or motoneurons, may underlie serotonin-dependent
plasticity in (spinal) respiratory motor control after CDR.
PMID- 10783402
TI - Prediction of short-term outcome in patients with suspected myocardial
infarction.
AB - STUDY OBJECTIVE: Although specific cardiac injury markers have enhanced early
patient classification, the ECG remains a necessary investigation in the acute
phase of chest pain. Combined use of both tests could further improve the
diagnostic and prognostic accuracy. METHODS: We studied 311 consecutive patients
who came to the emergency department of a regional referral hospital for the
differential diagnosis of acute chest discomfort. The admission ECG was
classified using an automated interpretation program and tested together with
elevated admission creatine kinase isoform MB (CK-MB) and cardiac troponin I
(TnI) concentration for prediction of final myocardial injury (44%) and in
hospital mortality (14%). RESULTS: Combining the information from the admission
ECG and cardiac markers, the sensitivity for becoming final myocardial injury
(maximal CK-MB >/=11 microg/L) was 90% and specificity 61%. The proportion of
false-negative results (10%) was independent of symptom duration. Age, positive
ECG findings, and increased admission TnI levels were predictive for in-hospital
mortality. CONCLUSION: The commonly available biochemical and ECG criteria allow
risk stratification of patients with a suspected acute ischemic event. The data
analysis can easily be automated and is independent of patient delay.
PMID- 10783403
TI - Atomized lidocaine as topical anesthesia for nasogastric tube placement: A
randomized, double-blind, placebo-controlled trial.
AB - STUDY OBJECTIVE: To evaluate the efficacy of topical atomized 4% lidocaine in
reducing the pain associated with nasogastric tube (NGT) placement. METHODS: This
prospective, randomized, double-blind, placebo-controlled trial was conducted in
the emergency department of a university teaching hospital. Study participants
were alert, hemodynamically stable adult patients requiring NGT placement for
diagnostic or therapeutic purposes. Atomized 4% lidocaine or normal saline
solution was administered in the nasopharynx and oropharynx before NGT placement.
All patients also received topical 2% lidocaine jelly intranasally after
atomization. The pain of NGT placement was measured using a standard 100-mm
visual analog scale. RESULTS: A total of 40 patients were enrolled in the study,
with 20 in the lidocaine group and 20 in the placebo group. Mean pain scores were
37.4 mm (95% confidence interval [CI] 25.4 to 49.4) for atomized lidocaine and
64.5 mm (95% CI 51.8 to 77.1) for placebo with a mean difference of 27.1 mm (95%
CI 14.8 to 39.4), achieving both clinical and statistical significance.
CONCLUSION: Atomized nasopharyngeal and oropharyngeal 4% lidocaine results in
clinically and statistically significant reductions in pain during NGT placement.
PMID- 10783404
TI - Determinants of patient satisfaction and willingness to return with emergency
care.
AB - STUDY OBJECTIVE: To identify emergency department process of care measures that
are significantly associated with satisfaction and willingness to return.
METHODS: Patient satisfaction and willingness to return at 5 urban, teaching
hospital EDs were assessed. Baseline questionnaire, chart review, and 10-day
follow-up telephone interviews were performed, and 38 process of care measures
and 30 patient characteristic were collected for each respondent. Overall
satisfaction was modeled with ordinal logistic regression. Willingness to return
was modeled with logistic regression. RESULTS: During a 1-month study period,
2,899 (84% of eligible) on-site questionnaires were completed. Telephone
interviews were completed by 2,333 patients (80% of patients who completed a
questionnaire). Patient-reported problems that were highly correlated with
satisfaction included help not received when needed (odds ratio [OR] 0.345; 95%
confidence interval [CI] 0.261 to 0.456), poor explanation of causes of problem
(OR 0.434; 95% CI 0.345 to 0.546), not told about potential wait time (OR 0.479;
95% CI 0.399 to 0.577), not told when to resume normal activities (OR 0.691; 95%
CI 0.531 to 0.901), poor explanation of test results (OR 0.647; 95% CI 0.495 to
0.845), and not told when to return to the ED (OR 0.656; 95% CI 0. 494 to 0.871).
Other process of care measures correlated with satisfaction include nonacute
triage status (OR 0.701, 95% CI 0.578 to 0.851) and number of treatments in the
ED (OR 1.164 per treatment; 95% CI 1.073 to 1.263). Patient characteristics that
significantly predicted less satisfaction included younger age and black race.
Determinants of willingness to return include poor explanation of causes of
problem (OR 0.328; 95% CI 0.217 to 0.495), unable to leave a message for family
(OR 0.391; 95% CI 0.226 to 0. 677), not told about potential wait time (OR 0.561;
95% CI 0.381 to 0.825), poor explanation of test results (OR 0.541; 95% CI 0.347
to 0.846), and help not received when needed (OR 0.537; 95% CI 0.340 to 0.846).
Patients with a chief complaint of hand laceration were less willing to return
compared with a reference population of patients with abdominal pain. Willingness
to return is strongly predicted by overall satisfaction (OR 2.601; 95% CI 2.292
to 2.951). CONCLUSION: These data identify specific process of care measures that
are determinants of patient satisfaction and willingness to return. Efforts to
increase patient satisfaction and willingness to return should focus on improving
ED performance on these identified process measures.
PMID- 10783405
TI - Gastric lavage for liquid poisons.
AB - STUDY OBJECTIVE: This study was conducted to determine whether gastric lavage
reduces the absorption of ingested liquids. METHODS: The study design was a
randomized controlled human volunteer crossover study in 10 subjects. On 2
separate occasions 2 weeks apart, the volunteers ingested a solution of 4.0 g of
acetaminophen in 60 mL of water. Eight blood specimens were obtained over the
initial 8 hours for determination of serum acetaminophen concentrations, which
were used to calculate routine pharmacokinetic parameters. One hour after 1 drug
ingestion, gastric lavage was performed through a 34-F orogastric tube. Serum
acetaminophen concentrations were measured by high-performance liquid
chromatography and a 2-tailed t test was used for statistical analysis. RESULTS:
The mean values for area under the concentration curve (+/-SD) for the control
and gastric lavage groups were 195+/-31 and 154+/-52 mg/L.hour, respectively (P
<.05). The mean reduction in acetaminophen bioavailability because of gastric
lavage was 20%+/-28% (95% confidence interval 3 to 37). CONCLUSION: In this
experimental model for the ingestion of liquids, gastric lavage at 1 hour
resulted in a significant decrease in the mean serum bioavailability of
acetaminophen. Nonetheless, this treatment effect is unlikely to be of clinical
value because of its modest extent, unreliable performance, and the availability
of a more effective, less risky alternative, activated charcoal.
PMID- 10783406
TI - Poisoning mortality in the United States: comparison of national mortality
statistics and poison control center reports.
AB - STUDY OBJECTIVE: To determine whether the distributions of age and poisoning
categories for poisoning deaths are similar in death certificates as compiled by
the National Center for Health Statistics (NCHS) and US poison control centers as
reported by the Toxic Exposure Surveillance System (TESS). METHODS: Data from
both databases for 1994 were examined. Mortality data from NCHS were identified
by applicable E-codes of the International Classification of Diseases-ninth
revision (ICD-9). All fatalities described in the TESS report were coded to
conform to the ICD-9 system. RESULTS: A total of 16,527 poisoning deaths were
recorded by NCHS; 766 deaths were reported by TESS. For NCHS and TESS,
respectively, the age distribution of unintentional drug poisonings (N=7,823;
155) and unintentional non-drug poisonings (N=1,234; 102) differed (P <.001),
whereas those for intentional poisonings (N=5,320; 413) did not differ
significantly. In the NCHS and TESS data sets, respectively, the relative
distribution of death circumstances differed (P <.001) for unintentional drug
poisonings (47% versus 20%), unintentional non-drug poisonings (8% versus 14%),
intentional poisonings (32% versus 54%), and unknown or other circumstances (13%
versus 12%). The distributions of poisoning circumstances and age categories were
dependent on the data source (P <.001). There was no statistical agreement
between the data sets in rankings of the 12 most frequent ICD-9 codes and toxins
associated with poisoning deaths. CONCLUSION: Deaths reported in TESS represent
5% of the poisoning deaths tabulated by NCHS. Differences observed in the 2 data
sets may lead to differing health policies to address poisoning hazards.
PMID- 10783407
TI - Chest pain centers: diagnosis of acute coronary syndromes.
AB - Chest pain centers in the emergency department have generally been accepted as a
safe, cost-effective, and rapid approach to the evaluation, triage, and
management of patients with potential acute coronary syndromes. These centers
were initially designed to enhance patient care by decreasing time to treatment
for acute myocardial infarction (AMI) and rapidly identifying patients with
unstable angina. They also included community outreach and educational objectives
designed to reduce time from the onset of chest pain to ED presentation. In the
past decade, health care financial constraints have created additional impetus to
the development of chest pain centers. Cost reduction efforts have occurred to
reduce hospitalizations, lengths of stay, and unnecessary treatments and
procedures. Practitioners and administrators try to balance these goals with the
imperative to provide high-quality patient care. Protocol-driven approaches have
been developed for specific disease processes in emergency settings. The chest
pain center concept is such an approach for patients with chest pain. Chest pain
is the second most common ED presenting complaint and is a symptom related to the
leading cause of death in the United States, coronary artery disease (CAD). One
third of ED patients with chest pain will eventually have a diagnosis of acute
coronary syndrome. Many patients with acute coronary syndromes have atypical
presentations that are not diagnosed in the ED with the traditional diagnostic
evaluation of a history, physical examination, and 12-lead ECG. If they are not
admitted to the hospital for further evaluation, the diagnosis may be missed. The
2% to 5% of AMI patients who are inadvertently released home often have poor
outcomes and result in a leading cause of malpractice suits in emergency
medicine. More than one half of ED patients with chest pain have clinical
findings after their initial evaluation consistent with acute coronary syndromes
and are admitted to the hospital. Approximately one half of these patients, after
evaluation in the hospital, are found not to have acute coronary syndromes. The
cost for these negative inpatient cardiac evaluations has been estimated to be $6
billion in the United States each year. Today, chest pain centers serve as an
integral component of many EDs. Their success and safety is the result of a
focused, protocol-driven approach directed at the acute coronary syndrome
continuum from unstable angina to transmural Q-wave myocardial infarction. New
therapies for acute coronary syndromes make ED triage and risk stratification
increasingly important. Although different chest pain center protocols have
proved effective, all address the diagnosis and rapid treatment of acute
myocardial necrosis, rest ischemia, and exercise-induced ischemia. Identifying
patients with coronary artery disease in one of these stages in the spectrum of
myocardial ischemia is the foundation for a successful chest pain center in the
ED.
PMID- 10783408
TI - National Heart Attack Alert Program position paper: chest pain centers and
programs for the evaluation of acute cardiac ischemia.
AB - The National Heart Attack Alert Program (NHAAP), which is coordinated by the
National Heart, Lung, and Blood Institute (NHLBI), promotes the early detection
and optimal treatment of patients with acute myocardial infarction and other
acute coronary ischemic syndromes. The NHAAP, having observed the development and
growth of chest pain centers in emergency departments with special interest,
created a task force to evaluate such centers and make recommendations pertaining
to the management of patients with acute cardiac ischemia. This position paper
offers recommendations to assist emergency physicians in EDs, including those
with chest pain centers, in providing comprehensive care for patients with acute
cardiac ischemia.
PMID- 10783409
TI - Cardiac arrest and the role of thrombolytic agents.
AB - Thrombolytic agents may have clinically significant beneficial effects in cardiac
arrest. The application of thrombolytic drugs in the setting of current and
antecedent cardiopulmonary resuscitation is well documented; however, it has not
been systematically studied nor has it been widely considered. We provide a
literature review of thrombolytic agents and cardiopulmonary resuscitation to
discuss the need for randomized controlled trials and the possibility of benefits
in acute resuscitation.
PMID- 10783410
TI - Report of the Task Force on Residency Training Information (1999-2000), American
Board of Emergency Medicine.
AB - The American Board of Emergency Medicine gathers extensive background information
on emergency medicine residents and the programs in which they train. We present
the third annual report on the status of US emergency medicine residency
programs. [American Board of Emergency Medicine. Report of the Task Force on
Residency Training Information (1999-2000), American Board of Emergency Medicine.
Ann Emerg Med. May 2000;35:481-498.]
PMID- 10783411
TI - Emergency department customer satisfaction: the point of view paradox.
PMID- 10783412
TI - Tissue plasminogen activator in pediatric myocardial infarction.
AB - Children rarely present to emergency physicians during an acute myocardial
infarction. However, this may occur in the setting of Kawasaki disease with
thrombosed coronary aneurysms. We present the first case in which intravenous
tissue plasminogen activator was used to successfully treat a 7-year-old child
having an acute myocardial infarction caused by a thrombosed coronary aneurysm.
PMID- 10783413
TI - Geographic variation in penicillin resistance in Streptococcus pneumoniae:
selected sites, United States, 1997.
PMID- 10783414
TI - Are we, as physicians, entitled to our frame of reference?
PMID- 10783415
TI - Small-dose inhaled nitric oxide and pulmonary embolism.
PMID- 10783416
TI - Small-dose inhaled nitric oxide and pulmonary embolism
PMID- 10783417
TI - Harmonization of data collection on poisonings.
PMID- 10783418
TI - Meeting the SAEM ultrasound guidelines. Society for Academic Emergency Medicine.
PMID- 10783419
TI - Clinical policy: critical issues in the evaluation and management of adult
patients presenting with suspected acute myocardial infarction or unstable
angina. American College of Emergency Physicians.
AB - This clinical policy focuses on critical issues in the evaluation and management
of patients with acute myocardial infarction or unstable angina. A MEDLINE search
for articles published between January 1993 and December 1998 was performed using
combinations of the key words chest pain, acute myocardial infarction, unstable
angina, thrombolytics, primary angioplasty, 12-lead ECG, ST-segment monitoring,
cardiac serum markers, and chest pain centers. Subcommittee members and expert
peer reviewers also supplied articles with direct bearing on the policy. This
policy focuses on 5 areas of current interest and/or controversy: (1) ECG
eligibility criteria for fibrinolytic therapy, (2) role of primary angioplasty in
patients with acute myocardial infarction, (3) use of serum markers to diagnose
acute myocardial infarction, (4) serial 12-lead ECGs during the initial
evaluation, and (5) chest pain evaluation units. Recommendations for patient
management are provided for each of these 5 topics based on strength of evidence
(Standards, Guidelines, Options). Standards represent patient management
principles that reflect a high degree of clinical certainty; Guidelines represent
patient management principles that reflect moderate clinical certainty; and
Options represent other patient management strategies based on preliminary,
inconclusive, or conflicting evidence, or based on panel consensus. This
guideline is intended for physicians working in hospital-based emergency
departments or chest pain evaluation units.
PMID- 10783420
TI - ECG eligibility criteria for emergent fibrinolytic therapy. American College of
Emergency Physicians.
PMID- 10783421
TI - The role of primary angioplasty in patients presenting with acute myocardial
infarction. American College of Emergency Physicians.
AB - The role of primary coronary angioplasty in AMI patients presenting to the ED in
cardiogenic shock or who have an absolute contraindication to fibrinolytic
administration is well established. (1,2) In contrast, the role of primary
angioplasty in patients with AMI eligible for fibrinolytic therapy is
controversial.(3) A number of prospective trials have been conducted to address
the issue of primary angioplasty versus fibrinolytic therapy with varying
results. (4-12) Several of these studies have found modest but statistically
significant benefits in short-term mortality, reinfarction rates, infarct size,
and/or complication rates.(4-8) Other studies failed to confirm these benefits
and found the 2 therapies to be of equal value.(9-12) Emergency physicians who
practice in centers that offer primary angioplasty are frequently faced with the
conundrum of whether to activate the emergency cardiac catheterization team or
give fibrinolytic therapy in the ED. Likewise, emergency physicians who practice
in a hospital that does not offer angioplasty face a similar dilemma if they have
a patient with an AMI who they believe might benefit from immediate transfer to a
facility with cardiac catheterization capabilities. A recent meta-analysis
analyzed 10 prospective studies comparing primary angioplasty with intravenous
fibrinolytic therapy and found that the mortality rate for 30 days or less was
4.4% for 1,290 patients treated with primary angioplasty compared with 6.5% for
1,316 patients treated with fibrinolytic agents (95% confidence intervals 0.46 to
0.49, P =.02).(13) When death was combined with nonfatal reinfarction, the rates
were 7.2% for angioplasty and 11.9% for fibrinolytic therapy. In addition,
angioplasty was associated with a statistically significant reduction in total
strokes (0.7% versus 2.0%) and hemorrhagic stroke (0.1% versus 1.1%). Although
the apparent benefit of primary angioplasty found in this analysis is enticing, 3
caveats must be considered before reaching a definitive conclusion. First, there
is acknowledged potential for bias in both the quantitative review techniques and
the enrollment practices of the individual studies reviewed.(14) Second, the time
from presentation to the ED to inflation of the balloon in the angiography suite
is relatively rapid in most of the studies used for the analysis, and in order
for a center to duplicate these results, it is reasonable to presume they must be
able to consistently equal or improve on the door-to-balloon times in the
published studies. Although no clinical study definitively establishes the ideal
door-to-balloon time, it may be reasonable to extrapolate that the balloon time
ideally would be less than 90 minutes from time of ED diagnosis of AMI. Likewise,
the experience of the interventionist is of critical importance and the procedure
must be done at a high-volume center similar to those used in the reported
trials. Third, there continue to be advances in interventional techniques, such
as the use of platelet inhibitors and coronary stents, that may modify future
results. Currently it can be concluded that primary angioplasty, when conducted
in a timely manner in experienced hands, is a viable alternative to fibrinolytic
therapy. When the element of time or experience is uncertain or cannot meet
stringent criteria, fibrinolytic therapy remains the treatment of choice.
PMID- 10783422
TI - Serum marker analysis in acute myocardial infarction. American College of
Emergency Physicians.
PMID- 10783423
TI - Serial 12-lead ECGS in the emergency department. American College of Emergency
Physicians.
PMID- 10783424
TI - Chest pain evaluation units. American College of Emergency Physicians.
PMID- 10783425
TI - The case for hospice care in long-term care environments.
AB - Hospice care typically is underused in long-term care facilities. Although these
programs do provide other quality services, routine measurement of important
parameters of end-of-life care, such as pain control, dyspnea, and spiritual and
psychosocial issues, should also occur. Health care providers working in long
term care facilities should be held accountable for high-quality care for dying
residents. In this environment, the benefits of hospice or hospicelike services
may become immediately apparent. Continued attention to changes in the Medicare
Hospice Benefits to improve patient access to hospice services and health care
delivery for those living in long-term care facilities is warranted.
PMID- 10783426
TI - Care of the dying in long-term care settings.
AB - A team of caregivers provides health care in nursing homes. This team is led by a
nurse and includes a physician, nursing assistants, and other nursing home staff.
Given the future demand for palliative care in this setting, the roles of all
caregivers need to be supported with meaningful training, improved working
conditions, and respect for each caregiver's contribution.
PMID- 10783427
TI - Talking to the older adult about advance directives.
AB - Discussing advance care plans with elderly patients can improve the experience of
end-of-life care for patients, families, and health care teams. Specific goals
for any particular discussion should be based on patients' particular clinical
circumstances. Physicians should focus on patients' overall values and goals and
should provide emotional support during the discussion. Decisions made during the
advance care planning process should be documented.
PMID- 10783428
TI - Advance directives: older adults with dementia.
AB - The benefits and risks for older adults with dementia executing advance
directives are discussed. Salient issues related to decision-specific capacity
and models for advance planning and end-of-life decisions by cognitively impaired
older adults are presented.
PMID- 10783429
TI - Advances in pain management for older adult patients.
AB - Management of pain is crucial to the success of any program of care and support
for dying patients and their families. Pain can be controlled in more than 90% of
older adults. Components of an effective program include comprehensive, repeated
pain assessment; detection and treatment of complicating medical and
psychological disorders (e.g., delirium); spiritual concerns; and the judicious
use of nonpharmacologic and pharmacologic therapies, radiation, and
radiopharmaceuticals. Strategies that enable clinicians to prevent and treat the
expected complications of nonsteroidal anti-inflammatory and opioid therapies are
reviewed. Strategies to change opioid agents or routes to minimize opioid-induced
side effects and to provide effective pain relief as death nears are presented.
PMID- 10783430
TI - Nutrition and hydration in terminally ill patients: an update.
AB - Many health care professionals lack knowledge about artificial nutrition and
hydration at the end of life or may hold different attitudes about artificial
nutrition and hydration compared with other treatments. Consequently, they may
convey inaccurate or misleading information to patients or their surrogate
decision makers. An updated understanding about artificial nutrition and
hydration in light of prevailing medical evidence is presented.
PMID- 10783431
TI - Antisecretory agents in gastrointestinal obstruction.
AB - Gastrointestinal obstruction is associated with nausea, vomiting, and abdominal
pain. Antisecretory agents can relieve these symptoms, even in the absence of
surgical or mechanical intervention. These medical management approaches are
outlined, and recommendations are made.
PMID- 10783432
TI - Depression and the dying older patient.
AB - Depression remains a source of considerable suffering among dying older adults.
Unfortunately, clinical depression commonly is overlooked in this vulnerable
population and often goes untreated. An overview of diagnosing depression in
older patients is presented. Various risk factors for depression in the
palliative care setting are examined. The somatic therapies that are available
for treatment consideration in older, depressed adults nearing death are
reviewed.
PMID- 10783433
TI - Delirium in the terminally ill.
AB - Delirium is highly prevalent in terminally ill patients, especially in the last
weeks of life, when some cognitive impairment develops in as many as 85% of
patients. Delirium is associated with increased morbidity in terminally ill
patients and can interfere with pain and symptom control. The cause of delirium
is usually multifactorial and often cannot be found or reversed in dying
patients. Nonpharmacologic and pharmacologic interventions are effective in
controlling the symptoms of delirium in terminally ill patients. Haloperidol and
other newer neuroleptics are safe and effective in eliminating delirium for some
patients. In approximately one third of patients, delirium can be managed
successfully only by providing sedation.
PMID- 10783434
TI - Palliative care for advanced dementia.
AB - Dementia is a common, devastating, and ultimately fatal illness. Although no cure
exists for most causes of dementia, palliative interventions for the predictable
complications of the illness can effectively reduce the suffering of patients and
families. Care of patients with end-stage dementia is clinically and conceptually
consistent with hospice and palliative care, and this approach to care for
patients with terminal dementia is preferred. Although the 6-month risk for
mortality can be predicted (to satisfy current American hospice eligibility
requirements), palliative care interventions are appropriate much earlier in the
course of deterioration from dementia.
PMID- 10783435
TI - Measuring quality in end-of-life care.
AB - Scrutiny of the quality of medical care near the end of life is increasing.
Experts have begun to define and conceptualize quality of care for dying patients
and are developing measurement tools to assess quality of care in this
population. Definitions and conceptual models of quality of care at the end of
life are reviewed. Approaches for measuring the processes and outcomes of end-of
life care are discussed. Approaches for initiating quality assessment of end-of
life care among geriatric patients are suggested.
PMID- 10783436
TI - Citation for the Down Surgical Prize 1998--Michael Wake.
PMID- 10783437
TI - Citation for the BAOMS Surgery Prize 1998--Mark McGurk.
PMID- 10783438
TI - Helix rim advancement for reconstruction of marginal defects of the pinna.
AB - Helical rim defects commonly result from excision of neoplasms or from injury.
Various techniques for reconstruction of such defects have been described. The
wedge excision technique that is commonly described in texts causes butterfly
deformity, webbing and cupping of the pinna and the authors believe that it
should be abandoned. Helix rim advancement flaps were first described 30 years
ago and offer a simple and versatile method for reconstruction with excellent
cosmetic results. Line drawings and photographs show the operative sequence and
the end results of such flaps.
PMID- 10783439
TI - Burkitt's lymphoma presenting as mandibular swelling--report of a case and review
of publications.
AB - Burkitt's lymphoma in a 4-year-old Chinese boy presented with acute mandibular
swelling but no associated systemic disturbance. A review of published reports
shows that the diagnosis should be suspected in jaw lesions with no obvious
cause.
PMID- 10783440
TI - Clinical and functional staging of oral submucous fibrosis.
AB - OBJECTIVE: To investigate the association of location of bands in oral submucous
fibrosis and extent of mouth-opening. DESIGN: Cross-sectional study. SETTING:
University hospital, Pakistan. SUBJECTS: 325 patients who presented with oral
submucous fibrosis in Karachi between January 1992 and October 1994, of whom 288
had data sufficient for analysis. MAIN MEASURES: Location of fibrous bands in the
mouth and interincisal distance (mm). RESULTS: All subjects with labial bands had
bands in the fauces, and all but one who had labial bands also had buccal bands.
All those with buccal bands also had bands in the fauces. Of those with buccal
bands, 42% did not have labial bands. The proportion of patients with bands in
all three sites increased from functional stage A (interincisal opening < or = 10
mm) to stage C (interincisal opening > or = 20 mm) with a simultaneous reduction
in the proportion of people with bands in one or two sites (X2 = 105, df = 4, P <
0.0001). CONCLUSIONS: Bands are common at the back of the mouth in mild cases of
oral submucous fibrosis and, as the disease increases in severity, are more
likely to be found anteriorly as well.
PMID- 10783441
TI - Bone grafting technique to increase interdental alveolar bone height for
placement of an implant.
AB - We have developed a simple, one-step technique for chin bone onlay grafting
combined with simultaneous implant placement to increase alveolar bone height
without any support system. We have used it to place 14 implants in nine
patients; eight recovered uneventfully but, in the other one, the wound broke
down and the exposed chin bone necrosed. After a mean follow-up period of three
years (range 1.5-4.7) the clinical and radiological outcome has remained good in
those eight patients.
PMID- 10783442
TI - Clinicopathological study of peripheral odontogenic fibromas (WHO-type) in
Malaysians (1967-95).
AB - Analysis of case records of 46 patients with peripheral odontogenic fibroma (1967
95) diagnosed in the Division of Stomatology, Institute for Medical Research,
Kuala Lumpur, disclosed a relatively young age of onset (mean, 32.2 years; range
5 months-64 years; peak incidence second decade of life), a slight female
preponderance (M:F ratio 1:1.3), no racial predilection, a slight bias towards
location in the mandible (52%) and a wide histomorphological range. All cases
were treated by simple excision. Follow-up records were generally not available,
so we do not know what the recurrence rate is.
PMID- 10783443
TI - Maternal risk factors in cleft lip and palate: case control study.
AB - Three hundred and six mothers who gave birth to babies with cleft lip, or palate,
or both, were matched with 306 who gave birth to healthy babies in the same area
during the same time period. Significantly more babies in the cleft group had a
family history of clefts (48/306 compared with 7/306, P<0.0001). In the cases
studied, combined cleft lip and palate was significantly more common among boys
(82/157 compared with 57/149, P=0.02) and cleft palate alone among girls (48/149
compared with 22/157, P=0.0002). Significantly more mothers reported some sort of
illness during early pregnancy (101/306 compared with 74/306, P=0.02). There were
no differences between the groups as far as dietary preferences were concerned
but during early pregnancy the mothers who gave birth to babies with defects
tended to drink less alcohol (<1 unit/week) (236 compared with 199, P=0.001) and
less coffee (<1 cup/week) (159/306 compared with 131, P=0.03). However, in each
case similar proportions gave up once the pregnancy was confirmed. Large
multicentre studies are required to confirm or refute these findings.
PMID- 10783444
TI - A comparison of growth impairment and orthodontic results in adult patients with
clefts of palate and unilateral clefts of lip, palate and alveolus.
AB - OBJECTIVE: To evaluate and compare the long-term aesthetic and functional results
of surgical and orthodontic treatment in patients with cleft palate and
unilateral cleft lip, palate, and alveolus. DESIGN: 30 patients with unilateral
cleft lip, palate, and alveolus and 30 patients with isolated cleft palate, mean
age of 18.9 years, were evaluated by cephalometric and model analysis a mean of
1.5 years after orthodontic treatment. In each group the surgical treatment has
been similar. RESULTS: Model analysis: The sum of every mesiodistal tooth
diameter in the maxilla and in the mandible was recorded according to the Bolton
analysis. Twenty patients with unilateral cleft lip, palate and alveolus had
relatively large upper dental arches and nine had relatively large lower dental
arches. Twenty-two patients with cleft palates had large upper dental arches and
seven had large mandibular arches. Eleven patients with unilateral cleft lip,
palate, and alveolus and 18 patients with cleft palate had a negative space
supply (the sum of the mesiodistal tooth diameters compared with the sagittal
length of the alveolar ridge) in the region of the lateral teeth. All patients
had persistent transverse space deficits that were increased on the side of the
cleft in patients with cleft lip, palate, and alveolus. These unilateral
transversal space deficits were recorded in 22 patients with unilateral cleft
lip, palate, and alveolus and in 8 patients with isolated cleft palate. Sagittal
measurements were reduced in 26 patients with unilateral cleft lip, palate, and
alveolus and in 23 patients with cleft palate alone. The alveolar midline of the
maxilla and the mandible were displaced in 25 patients with unilateral cleft lip,
palate, and alveolus and in 19 patients with isolated cleft palate. Lateral
cephalometric analysis: The lateral cephalograms taken at the same time as the
models showed a mean SNA of 76.8 degrees and a NL-NSL angle of 8.7 degrees,
indications of a tendency towards maxillary retrognathia in patients with
unilateral cleft lip, palate, and alveolus. Patients with cleft palate had a mean
SNA of 79.6 degrees and NL-NSL angle of 8.1 degrees. The anterior facial vertical
index was within normal limits in patients with cleft lip, palate, and alveolus
(44% vs 56%). An anterior facial height index of 42% compared with 58% in
patients with isolated cleft palate indicated a slight reduction in midface
height with an increase in the lower face as a consequence. CONCLUSION:
Orthodontic and surgical treatment can result in satisfactory results on model
analysis. However, there is specific growth impairment of the maxilla 1.5 years
after termination of orthodontic treatment and this influences the final
cephalometric analysis, particularly in patients with cleft lip, palate, and
alveolus.
PMID- 10783445
TI - Pull-through technique of scapular osteocutaneous flap to decrease frequency of
positioning change.
AB - During reconstructions of the head and neck regions with a scapular or a scapular
osteocutaneous flap, it is usually necessary to reposition the patient twice and
prepare the operating field three times for removal of tumor, harvesting the
flap, and reconstruction. This is one of the main disadvantages of the scapular
flap. We have used the pull-through technique to reduce the number of changes in
position that are required. In addition, the ischaemic time of the flap is also
substantially reduced. The flap is first raised and then tunneled through the
axilla to lie passively on the chest while the tumor is excised. These procedures
have been followed in 13 cases of scapular and scapular osteocutaneous flap with
no problems.
PMID- 10783446
TI - Progress of ossification and epithelialization of wounds after simple or surgical
extractions of teeth in rats with chronic renal failure: an experimental study.
AB - Our aim was to investigate the progress of wound healing after simple and
surgical removal of the first two molars of the right and left maxillary
segments, respectively, in Wistar rats with experimentally induced moderate
chronic renal failure (CRF). Sixty Wistar rats were divided into two groups of 30
rats each: experimental and control. CRF was induced in the experimental group by
an intraperitoneal injection of cisplatin, 5 mg/kg body weight (BW) initially and
then with two maintenance doses of 2.5 mg/kg BW at intervals of one month. The
teeth were extracted one month after the last dose of cisplatin. The sockets and
the kidneys of all the rats of both groups were evaluated. The mandibles of the
15 rats in the experimental group that developed moderate CRF, together with
those of two controls, were evaluated for abnormalities that suggested renal
osteodystrophy. The histopathological examination showed: (a) that there were no
significant differences in the pattern of wound healing no matter how the tooth
was extracted; (b) there were no specific abnormalities in the mandible to
indicate of secondary hyperparathyroidism or renal osteodystrophy; and (c) the
kidneys of the rats of the experimental group underwent histopathological changes
that were significantly different from those in the controls (P < 0.001). Our
results indicate that moderate CRF does not have any appreciable or significant
modifying effect on wound healing after tooth extraction in Wistar rats.
PMID- 10783447
TI - Exposure of high-density porous polyethylene (Medpor) used for contour
restoration and treatment.
AB - Porous high-density polyethylene (Medpor) is a biocompatible large-pore, high
density polyethylene implant. It is well tolerated by surrounding tissue, and its
porous structure is rapidly infiltrated by host tissue. It is a highly stable and
somewhat flexible porous alloplast that has rapid tissue ingrowth into its pores.
However, when the implant is placed under a thin cover of skin, there is a risk
of exposure. A total of 52 Medpor implants were placed in 31 patients over a four
year period. The implants were used for the chin, malar area, nasal
reconstruction, ear reconstruction, orbital reconstruction, and the correction of
mandibular contour deformities. Many of these implants were placed in areas
considered problematic, such as those with thin or atrophic soft-tissue coverage
and extensive scarring. There were nine complications, including three patients
in whom the implant was exposed; these are presented here.
PMID- 10783448
TI - Lack of correlation between water hardness and salivary calculi in England.
AB - Our aim was to test the hypothesis that residents of hard water areas are at
increased risk of developing salivary calculi. The evidence based on figures from
the Hospital Episode Statistics database for the years 1991 to 1994, suggests
that there is no such association. For example, in the South West Water area
(soft water) the incidence was 28.92/million/year compared with Yorkshire (hard
water) 31.64/million/year. The correlation coefficient shows that water hardness
is not significantly associated with either the incidence of salivary calculi (r
= 0.02, P = 0.9) or that of sialadenitis (n = 2.4, P = 0.4). The lack of
association holds for both men and women independently. However, the two
conditions have similar patterns of incidence (r = 0.5, P = 0.05), suggesting
some common but unknown similarity in aetiology.
PMID- 10783449
TI - Correction of recurrent dislocation of the mandible in elderly patients by the
Dautrey procedure.
AB - Twelve patients with recurrent mandibular dislocation, 11 of whom were over 50
years old, were treated by the Dautrey procedure using a temporal approach. None
experienced recurrence or developed complications such as restriction of mouth
opening, paresis of the facial nerve, or pain in the temporomandibular joint
during a follow-up period that ranged from 1.5 to 8 years.
PMID- 10783450
TI - The efficacy of Emla and 5% lignocaine gel for anaesthesia of human gingival
mucosa.
AB - OBJECTIVE: To compare the analgesic effect of a mixture of 2.5% lignocaine and
2.5% prilocaine (Emla) with that of lignocaine gel alone for minor operations on
the gingiva. DESIGN: Randomized double-blind trial. SETTING: Teaching hospital,
UK. SUBJECTS: 10 healthy dental students (7 men and 3 women, 20-21 years old).
INTERVENTIONS: Construction of a reservoir within a splint on each side of the
mouth and insertion of splints. The volunteers acted as their own controls, and
the sides used for each anaesthetic were chosen at random. MAIN OUTCOME MEASURES:
Measurement of pressure-pain threshold by a standard technique. RESULTS: The
median (range) duration of anaesthesia after Emla (22.5, 12-30) was significantly
longer than after lignocaine alone (12.5, 0-25) (P=0.01), and the area under the
curve for the pressure-pain threshold for Emla (2053, 199-4564) was significantly
greater than for lignocaine alone (986, 169-2942) (P=0.01). CONCLUSION: Emla is a
more effective topical anaesthetic agent than lignocaine alone. Although its
duration of action is relatively short it is adequate for minor operations on the
gingiva.
PMID- 10783451
TI - A retrospective study of unerupted maxillary incisors associated with
supernumerary teeth.
AB - We retrospectively reviewed the clinical records and radiographs of 100 patients
who had had supernumerary teeth removed. Their mean (SD) age was 9 years 3 months
(2). The 100 patients had a total of 127 unerupted maxillary incisors associated
with supernumerary teeth. The supernumerary tooth was removed without exposure of
the permanent tooth more often among the 79 younger children (aged 10 years or
less) (SND=3.52, P<0.01), and when the incisors were less mature (Cvek
classification 1, 2, and 3) (SND=5.27, P<0.01). Of these incisors with immature
roots that were treated conservatively, 60 (72%) erupted and 24 (28%) required
further operation. Of the mature incisors treated conservatively, 10 (63%)
required further operation. In this study, almost three-quarters of immature
incisors erupted spontaneously after removal of the associated supernumerary
teeth. Over half of the mature teeth required further operation. Mature teeth
should be exposed with or without bonding at the time of removal of the
supernumerary teeth.
PMID- 10783452
TI - Surgical and orthodontic rapid palatal expansion in adults using Glassman's
technique: retrospective study.
AB - In 1984, Glassman et al. described a conservative surgical method of separation
of the midpalatal suture in which an osteotomy is done only at the lateral and
anterior wall of the maxilla. Between 1991 and 1997, we have operated on 21
patients with maxillary transverse discrepancies using the method that they
described. This gave good results in 20 patients. The other, who was operated on
at the age of 38 years, developed a fracture of the alveolar process of the
maxilla on one side because of ossification of the midpalatal suture. The
surgically assisted rapid palatal expansion described by Glassman et al. is
suitable for patients up to the age of 30. Older patients require additional
surgical separation of the midpalatal suture.
PMID- 10783453
TI - Mechanical and biomechanical measurements of five currently available
osteosynthesis systems of self-tapping screws.
AB - Pressure force, uniaxial 'pullout', minimum torque, and peak torque tests were
done to evaluate the effectiveness of three popular monocortical and non
compressing self-tapping screw systems 2 mm in diameter (Champy, Centre-Drive,
and Wuerzburger) and two systems 1.5 mm in diameter (Champy and Wuerzburger). The
screw systems were all tested on polyvinylchloride plate, skull, and molar
mandibular bone from fresh human cadavers. The Champy screw 2 mm in diameter and
7 mm long produced the highest pressure force (mean (SD) 153.4 (58.5) N, n=40) of
the systems tested. The Centre-Drive screw of the same size showed the highest
retentive force in pullout tests (619.5 (169.9) N, n=40) and also the largest
difference between minimum and peak torque in skull and molar mandibular bone
(1.86 (0.65) kpcm, n=40). This was clinically relevant compared with reported
human bite-force (range 216-740 N). The results showed that, the screw diameter
and number of threads were the most important and significant of the mechanical
variables tested. The skull bone also exerted more retentive force than the molar
mandibular bone. The overall data indicate that there is no need to use screws
more than 7 mm long or wider than 2 mm in diameter for monocortical non
compressive osteosynthesis in the craniofacial and the mandibular region.
PMID- 10783455
TI - Contents list from the Japanese Journal of Oral and Maxillofacial Surgery (Volume
43 Number 12 1997).
PMID- 10783454
TI - Abstracts from Mund-, Kiefer- und Gesichtschirurgie(Volume 3, Number 6 1999).
PMID- 10783457
TI - Re: GDC specialist list.
PMID- 10783456
TI - Re: Peckitt. Stereoscopic lithography: customised titanium implants in orofacial
reconstruction: a new surgical technique without flap cover.
PMID- 10783458
TI - Reply to Carter & Holmes. Re: Stereoscopic lithography: customized implants in
orofacial reconstruction - a new surgical technique without flap cover.
PMID- 10783459
TI - Angiocentric T cell lymphoma of the paranasal sinuses: a difficult diagnosis.
PMID- 10783460
TI - Orbital floor injury with extraocular muscle entrapment following functional
endoscopic sinus surgery.
PMID- 10783461
TI - CT image of nasoalveolar cyst.
PMID- 10783463
TI - Bright light as an inhibitor of adenosine transport.
AB - The administration of bright light rapidly improves subjective alertness and is
likely to have direct effects on the activity of neurons in the suprachiasmatic
nucleus (SCN). Bright light may enhance wakefulness by interrupting the increase
in extracellular adenosine concentration with brain metabolism during the day.
Exposure to bright light is hypothesized to induce the inhibition of adenosine
transport, promoting both subjective alertness and activation measured
objectively, and to activate the cholinergic neurons of the reticular system and
those using gamma-aminobutyric acid as a neurotransmitter in the SCN.
PMID- 10783464
TI - Mechanisms of sudden infant death and the contamination of inspired air with
exhaled air.
AB - The physiological effects on an infant of repeatedly sleeping in an environment
consisting of a mixture of exhaled air and fresh air is examined. It is found
that adaptation can be predicted. A possible outcome of the adaptation is shown
to be the development of hypoxia when the conditions change during sleep from a
state with carbon dioxide contamination of inspired air to one without. This
hypoxia can be associated with apnoea: this apnoea can provide an explanation for
some instances of sudden infant death. This explanation is consistent with the
known epidemiology and environmental associations of a proportion of sudden
infant death syndrome. Safety precautions for the prevention of re-breathing are
given.
PMID- 10783465
TI - Proto-metastatic core and comet effect: new theoretical model of the mechanism of
metastasis generation.
AB - One important aspect of cancer is its capacity to generate metastasis. The
mechanism by which one or several neoplastic cells escape from the primitive
tumor to start the metastatic process is still a matter of discussion, hence the
need to reconsider under which circumstances and conditions 'lethal escape' is
produced. Thus we introduce two concepts: proto-metastatic core and comet effect.
We maintain that only one group of cells (proto-metastatic core) could escape
passively from the tumor focus when they enter the bloodstream together with
other detritus. The proto-metastatic core disintegrates through friction with the
blood (comet effect). There are two mechanism of metastasis. In the first, only
one cell leaves the vessel joined to white blood cells as it moves through an
inflamed area. The second, from the proto-metastatic core, could form venous
thrombus. We believe that this new theoretical model of the etiopathology of
cancer will contribute to future therapies.
PMID- 10783466
TI - What is the material base of acupuncture? The nerves!
AB - Acupuncture is a traditional Chinese medical method which has been used in the
treatment of patients for thousands of years. It is rejected by modern science
for lack of solid material background. In recent years, more and more laboratory
proof has accumulated that acupuncture can change the charge and potential of
neurons, the concentrations of K(+), Na(+), Ca(++) and the content of neuro
transmitters such as aspartate, and taurine and the quantities of neuro-peptides
such as beta-endorphin and leu-enkephalin. All these phenomena are directly
related to nerve cells. Now the lengthy discussion may conclude that nerve cells
and the central nervous system are the real material base of acupuncture.
PMID- 10783467
TI - Is fractal geometry useful in medicine and biomedical sciences?
AB - Fractal geometry has become very useful in the understanding of many phenomena in
various fields such as astrophysics, economy or agriculture and recently in
medicine. After a brief intuitive introduction to the basis of fractal geometry,
the clue is made about the correlation between Df and the complexity or the
irregularity of a structure. However, fractal analysis must be applied with
certain caution in natural objects such as bio-medical ones. The cardio-vascular
system remains one of the most important fields of application of these kinds of
approach. Spectral analysis of the R-R interval, morphology of the distal
coronary arteries constitute two examples. Other very interesting applications
are founded in bacteriology, medical imaging or ophthalmology. In our
institution, we apply fractal analysis in order to quantitate angiogenesis and
other vascular processes.
PMID- 10783468
TI - A new diagnostic system for psychiatry.
AB - The objective of this work is to apply theoretical concepts from system theories
to psychiatry, and formulate a novel diagnostic system that will combine the
advantages of descriptive diagnosis and biopsychosocial diagnosis in psychiatry.
Biopsychosocial factors and symptoms of mental disorders are described as
instabilities and perturbations in a system (i.e. the nervous system). The author
reviews certain basic concepts from system theories and applies them to clinical
concepts in psychiatry. Biopsychosocial factors are perceived as agitators of
organization in the nervous system, and symptoms are described as emergent
properties out of these perturbations. A profile of biopsychosocial factors is
plotted to correlate with a profile of perturbations and their related symptoms.
This agitator versus perturbation mapping is advantageous as a diagnostic system
for psychiatry. The proposed diagnostic system is of value in dealing with the
clinical complexity of mental disorders, has a potential for increasing
predictive validity in psychiatry, and may contribute to etiological brain
research of mental disorders.
PMID- 10783469
TI - Field recognition of pathogen and HIV self.
AB - There is evidence to suggest that the HIV virus is never presented clearly and
completely to the immune system. It is possible there is an additional
recognition system in skin it misses. By bypassing the skin in inoculation or
neutralizing skin presentation in semen, an envelope that may modify immune
response, pathogen may get by this additional field recognition system. In an
effort to engage this additional recognition system for more information about
the virus, the immune system may end up purposefully mutating the virus for the
wrong reason inadvertently establishing a repertoire of HIV self. The unique
circumstances of HIV presentation may cause this proposed additional normally
compatible recognition system to turn into a competing system.
PMID- 10783470
TI - Biophysical body-brain-mind unity: theory and practice.
AB - A novel substance-attributed biophysical theory of brain-mind unity is presented.
We separate spiritualism and matters of the soul from the medical sphere.
Biophysical principles are responsible for the body's operational regimen (BOR)
in the homeostatic state which allows for materialization and emergence of the
mind; Excitation and/or inhibition modulate 8 BOR stages. There is automatic
(somatic) and non-automatic (biophysical and psychological) Circadian cycle
control. Computer-analog input and output occurs in wired neuronal electric
pathways. Biotechnological devices located in emotional neurons positively signal
homeostatic and negatively signal deranged BOR and biophysical mind operations.
Macro and/or micro cerebral lesions which affect homeostasis may cause
psychopathology, which can be treated with 'instrumental psychotherapy' (IPT)
which enables recovery from homeostatic disorder in Phase 1, refining EGO in
Phase 2, and social competence in Phase 3. The theory of brain-mind unity and
practice of IPT is geared to medical workers and biophysical psychologists.
PMID- 10783471
TI - Immunoregulation via 'bystander suppression' needs minute amounts of substances-
a basis for homeopathic therapy?
AB - One of the main characteristics of homeopathic drugs is the low concentration of
substances they contain. In most discussions this serves as the predominant
argument against homeopathic treatments. The small amount of ingredients is in
most instances considered not to be able to induce significant changes in
classical pharmacological models. A few years ago researchers at the Harvard
Medical School in Boston observed that the auto-reactivity ofT-cells is managed
by the immune system in at least two different ways that obviously were dependent
upon the concentration of the antigen they encounter: If they see high
concentrations of a self-antigen they are deleted (killed), but when given low
doses they undergo a special kind of active inhibition (called 'bystander
suppression'). We feel that this type of regulation induced by very low substance
concentrations could serve as a model to explain the way in which at least some
homeopathic pharmaceuticals mediate their therapeutic effects.
PMID- 10783472
TI - Biocryptography.
AB - A new cryptology that uses biomolecules as carriers of hidden information is
described here. The huge dimension of biopolymers permits the insertion there of
private messages and the rapidity and specificity of biomolecular interactions
facilitate the identification of classified communications. Otherwise, this
process can be implemented in a virtual context.
PMID- 10783473
TI - Considerations upon the anatomical model of reward-based learning in the basal
ganglia.
AB - The nigrostriatal pathway appears to be very important in the reward-based
learning. The dopaminergic neurons in the substantia nigra pars compacta (SNC)
fire in relation to primary rewards and reward-conditioned stimuli, but not to
rewards that are expected. It has been hypothesized that the anatomical framework
for the selective response of these neurons is organized in the projections from
some paralimbic areas in the frontal lobe to the striosomes of the caudate
nucleus, which are also directly connected with the dopaminergic neurons of the
SNC. Here, we present two additional pathways that may be related with this
neurophysiological finding. We hypothesize that the connections of the paralimbic
cortices with the ventral system of the basal ganglia and then with the thalamus
and the hypothalamus, and the circuit ventral striatum-substantia nigra pars
reticulata-thalamus-striatum could be also involved in the reward-based learning.
PMID- 10783474
TI - Errors and biases in the diagnosis of cancer of the lung and their influence on
risk estimates.
AB - When diagnosed as primary lung cancer, metastases from the abdomen, plus false
negative cases have little effect on epidemiology studies of male smokers, but
may result in a severe dilution of the lung cancers among women and nonsmokers.
We have attempted to quantitate this handicap for epidemiological studies using
two approaches. The relative frequency of diagnosed primary lung and abdominal
cancer among males, women, and nonsmokers differs substantially and is used here
to calculate magnitude. The second approach postulates that the ratio of
nonsmokers among persons with squamous cell lung cancer and primary
adenocarcinoma of the lung would be constant by sex if there were no distortion
by abdominal metastases. These two approaches indicate that the much higher ratio
of metastatic disease diagnosed as primary lung cancer among nonsmoking women
(factor of 15 to 20), makes it more difficult to identify an environmental
carcinogen among women or nonsmokers than among male smokers in case-control
studies.
PMID- 10783475
TI - Siblings of sudden infant death syndrome and near miss in about 30 families: is
there a genetic factor?
AB - The purposes of this study were: (1) to compare our data with those reported in
the general population; (2) to find a factor implicated in repetitive accidents;
(3) to look for a possible genetic factor; and (4) to evaluate whether or not the
risk of recurrence was the same in a family with two or more infants having died
of sudden intant death syndrome (SIDS) as in the general population. We study
retrospectively 77 files which constitute a group of 30 families which was
analysed with reference to a list of data laid out in the shape of genealogical
trees. Our study shows that risk factors are similar to those described
previously and repetitive among siblings or cousins. The rate of recurrence is
not available for the general population. On studying some family trees, we can
speculate on the existence of an autosomal dominant gene with incomplete
penetrance.
PMID- 10783476
TI - Cancer incidences in the digestive tube: is cobalamin a small intestine
cytoprotector?
AB - Malignancies are common in the digestive tube, although with unequal distribution
among segments. The aim of this paper was to compare available interpretations of
the low cancer incidence in the small bowel and high in the large bowel. Supposed
mechanisms include relatively small bacterial population, large secretion of
liquid and rapid transit in the small bowel. Small bowel mucosa is the main
absorptive part of the digestive tube with absorption rates for various nutrients
so high that they can even be considered as clearances from the intestinal
content. Consequently, these nutrients are not present in the large bowel. An
alternative explanation is that an absorbable protective substance from the
intraluminal content, might protect the mucosa from malignant transformations. It
can be speculated that if there are any cytoprotective substances in the digested
food their effect would be expressed mostly in the absorptive small intestine,
leaving the large bowel mucosa unprotected. Vitamin B12 might be a possible
candidate for this role. Cobalamin molecules are initially bound to haptocorrin
(Hc) in the stomach, but in the small intestine B12 is transferred to intrinsic
factor (IF) after the action of pancreatic trypsin on Hc. Cobalamin-IF complexes
are absorbed in the terminal ileum leaving only a small fraction of B12 to enter
the large bowel. We have tried to summarize available data regarding cancer
incidences in digestive tube, segmental length and transit times of tube content.
Cancer density is calculated as incidence per length and transit speed as length
per transit time. Cancer incidences for seven intestinal segments were considered
low if they were below one case per 100 000 inhabitants annually, while the low
cancer density meant less than six cases per 100 000 inhabitants per metre. For
instance, transverse colon was considered as a high cancer incidence place (2.15
cases), with low cancer density (4.3 cases/m). Transit speed more than 0.3
metre/hour was associated with low cancer incidences (accuracy 0.85) and low
cancer density segments (accuracy 1.00). Cobalamin availability showed similar
distribution, available in low incidence segments and unavailable in high
incidence segments. Experimental studies are needed to quantify B12 availability
in the large bowel and to determine whether small amounts of B12-IF or, perhaps,
B12-haptocorrin complexes are absorbed by the small bowel mucosa. Without that,
no cytoprotective effects of B12 in the digestive tube can be expected.
PMID- 10783477
TI - A cycle of cerebrospinal fluid: supporting evidence and theoretical
considerations.
AB - An entrenched theory of cerebrospinal fluid (CSF) absorption by the arachnoid
villi fails to explain observations regarding the movement of substances in the
fluid. Experiments that demonstrated the arachnoid villi as the site of
absorption were based on non-physiologic methods. CSF does not flow through the
arachnoid villi, because villi require bulk flow and bulk flow of CSF does not
exist. CSF is transported through the choroid fissure and recycled through the
tela choroidae by the choroid plexus, with reentry into the ventricular system.
Observed failures of the effete arachnoid villus theory can be readily explained
by the cycling theory. A complete cycle of CSF is suggested to pace the 90 to 100
minute ultradian rhythms found in human physiology.
PMID- 10783478
TI - Ex vivo expanded allogeneic cord blood progenitor cell transplantation with a non
myeloablative conditioning regimen would cure autoimmune diseases.
AB - Loss of self-tolerance is the basis for autoimmune disease. Autologous as well as
allogeneic stem cell transplantation is increasingly being considered and used
for therapy of autoimmune disease. Non-myeloablative conditioning has been shown
in the context of malignant diseases to be feasible. Cord blood transplantation
has been associated with significantly less graft-versus-host disease (GVHD) than
other forms of allotransplantation. Ex-vivo expansion of this limited resource is
increasingly becoming feasible. It is being hypothesized that ex-vivo expanded
cord blood progenitor cell transplantation using a non-myeloablative conditioning
regimen would be curative in autoimmune diseases.
PMID- 10783479
TI - Long-term relapses of breast cancer: a neglected but important issue.
AB - The relatively frequent finding of long-term relapses from breast cancer, eight
years or more after the mastectomy, could indicate that breast cancer is a
particular neoplasm and even suggests that it could be a systemic disease. The
study of receptors in cases of long-term relapses instead indicate that breast
cancer, with the exception of the presence of hormonal receptors which influence
the clinical behavior, is similar to neoplasms that arise in other parts of the
body. It is possible that the presence of receptors indirectly conditions the
formation of antimitotic factors more effective than those known today, up to
determining in some cases the phenomenon of long-term relapses. Such factors are
presumably active also for neoplasms arising in other parts of the body.
PMID- 10783480
TI - Involvement of polyglutamine endolysis followed by pyroglutamate formation in the
pathogenesis of triplet repeat/polyglutamine-expansion diseases.
AB - The mechanism by which polyglutamine expansions in several proteins lead to
neurodegenerative disorders remains largely unknown. The biochemical properties
of polyglutamine repeats suggest one possible explanation; endolytic cleavage at
a glutaminyl-glutaminyl bond followed by pyroglutamate formation may contribute
to the pathogenesis through augmenting the catabolic stability, hydrophobicity,
amyloidogenicity, and neurotoxicity of the polyglutaminyl proteins. The
hypothesis points out novel therapeutic strategies to delay disease onset in
genetically diagnosed presymptomatic patients.
PMID- 10783481
TI - Rice hurts the stomach by its stickiness.
AB - Rice masses remove mucus from the stomach and duodenum as the sticky starch binds
the sticky mucus, weakening the defense against acid and pepsin which may in turn
cause heartburn and ulcer. Such unwanted effect can be avoided by taking enough
water with rice meal as water converts rice masses into slurry.
PMID- 10783482
TI - How calcium from calcium carbonate and milk benefit peptic ulcer patients.
AB - Calcium from calcium containing antacids and milk enhance the integrity of
gastrointestinal mucosa and mucus, as it is the natural linker agent of these
structures, which strengthens their defense function.
PMID- 10783483
TI - Lessons from the follow-up of developmental dyslexics.
AB - The follow-up of developmental dyslexics from childhood to maturity reveals
interesting and important facts. One of the main conclusions which can be reached
on considering these facts is that reading and writing can be acquired without
phonology. Many developmental dyslexics manage to reach high levels of literacy
while remaining seriously handicapped in their phonological skills. The
suggestion presented in this paper advocates the adoption of the practical
strategies employed by the dyslexics as the basis of the remedial methods to be
used in schools.
PMID- 10783484
TI - Pheromones cause disease: the exocrinology of anorexia nervosa.
AB - The aetiology of anorexia nervosa is exocrinological. This notion is supported by
physical evidence in animal models with directly comparable symptomatology.
Anorexia nervosa (AN) syndrome would be a puberty delay caused by reception and
autoreception of conspecific pheromone emissions: a pheromone-induced puberty
delay (PIPD). As such, it would be amenable to medical treatment drawing from
forty years of research in animals. This hypothesis is testable. For instance,
since food ad libitum is a prerequisite for PIPD, occasional supervised fasting
in healthy peripuberal subjects should prevent AN. Besides, tolerating an
untestable thought disease (1,2) with symptoms of a curable well-understood
animal condition would be anti-scientific and perpetuates medical disaster. Even
their endocrinologies are identical. Pheromone feedback tunes animal appetites
and immunity to available resources and prospects. In addition to timing puberty,
pheromones regulate fertility. Pheromones will probably be implicated in the
aetiology of the psychiatric and autoimmune diseases. This is the second in a
series of twelve papers to explore this contention systematically.
PMID- 10783485
TI - Cholinergic regulation of biological hydrodynamics.
AB - The structures of biological life are formed in water. Their function depends on
changes in the entropy of water. It is regulated by the cholinergic system. The
initiating event is the ChE-splitting of water with liberation of free protons.
They will draw electrons from the fairly inert dioxygen. The induced oxygen
reactivity will give liberation and transfer of electrons and hydrodynamic pH
dependent changes in protein configurations. A multitude of sub-systems will be
activated. The sequence of events normally ends with the formation of water, thus
preventing uncontrolled radical chain reactions. Cholinergic receptors appear as
restricting units of the general disordering entropy tendency. ChE-induced
hydrodynamics is propagated to the inner of cells by the water soluble protons
and the electrolytes. Especially Ca appear to have a strong influence on the
hydrodynamic dipole moment of water. Because water is an integral structure of
DNA genetics also will be influenced. Conditions caused by deprivation of oxygen
or of reactive oxygen and disorders by hyperactivity and inactivity are briefly
discussed. The CNS takes the shape of a large-scale quantum computer with a
function far beyond our ability of immediate perception. The atomic nuclear
proportions of quantum bits (qubits) will admit the functional one-cell unit of
immune memory cells. Cholinergic hydrodynamics appear to substantiate the much
discussed chaos theory.
PMID- 10783486
TI - Vaginal douching and preterm birth: an intriguing hypothesis.
AB - The rate of preterm birth has risen in recent years and is twice as high among
black women as among white women. Neither the underlying causes nor the reasons
for the racial disparity are clearly understood. Further, preventable risk
factors have not been identified. We hypothesize that vaginal douching plays a
key role in the risk of infection-related spontaneous preterm birth. Vaginal
douching is a common behavior, twice as prevalent among black women as among
white women. Douching may be an important mechanism by which vaginal pathogens
gain access to the upper genital tract. Douching increases the risk of acquiring
bacterial vaginosis. It may also facilitate the ascent of microorganisms into the
upper genital tract, resulting in a chronic bacterial colonization inside the
uterus. During pregnancy, the host inflammatory response is initiated, which
stimulates preterm labor and birth. Douching, a potentially preventable risk
factor, may explain a substantial proportion of the black-white disparity in
preterm birth.
PMID- 10783487
TI - Are proteases used as anti-inflammatory agents in reality accelerating the
inflammatory process?
AB - A possible anti-inflammatory effect of intraduodenally administered trypsin was
investigated using the paw oedema and pleurisy models of carrageenan-induced
inflammation in rats. No anti-inflammatory effect was detected by plethysmography
or on the basis of pleural leukocyte migration in treated animals compared to a
sham group. The groups were implanted with an intraduodenal catheter after
treatment with metopyrone, an inhibitor of endogenous corticosteroid synthesis.
Since surgical stress induces an anti-inflammatory effect of its own; the sham
group was an important control. Metopyrone antagonized surgical stress, and
trypsin inhibited oedema by about 16% four hours after carrageenan
administration, a nonsignificant reduction. Evans blue dye protein leakage into
the peritoneal cavity as a measure of vascular permeability demonstrated a pro
inflammatory effect of trypsin. The present results lead us to propose that
trypsin may be acting not as anti-inflammatory agent but by accelerating the
inflammatory process, thereby reducing the duration of the process.
PMID- 10783488
TI - Resistance of cancer cells to immune recognition and killing.
AB - It is well recognized that, in order for a wound to heal, the fibrin clot must be
eliminated by fibrinolytic enzymes. In certain instances, however, fibrin is
ineffectively degraded or even not degraded. For example, in pregnancy, the
placenta contains a layer of fibrin (Nitabuck's layer) which presents as 'self'
to the immune system. Similar situations have been observed in many solid tumors.
A hypothesis is presented according to which tumor cells can escape detection and
attack by the immune system in most cancer patients. The tumor dons a 'coat' of
the host's own protein on its cell surface. The coat is composed of fibrin and of
a polymeric form of human serum albumin (HSA) which, by contrast to pure fibrin,
is resistant to fibrinolytic degradation. Such a coated tumor appears as 'self'
to the immune system, and thus is not detected as a tumor by the immune system
(i.e. natural killer cells). When tumors are prepared for in vitro assays against
drugs, they are routinely treated with proteolytic enzymes (e.g. pepsin, or
chymotrypsin, etc.) which dissolve the protein coat, exposing the tumor cell
surface to the drug. Thus, the in vivo existence of a coat on the tumor surface
may explain why some drugs have little or no effect in vivo, while the same drugs
are active in vitro.
PMID- 10783489
TI - Ionizing radiation and mitogenetic radiation: two links of the same energetic
chain in a biological cell.
AB - Present research demonstrates that the excitation of living systems by high
energy/low doses of ionizing radiation (IR) initiates prolonged secondary
ultraviolet (UV) range emission that influences biota. When doses of this energy
are too high, the process of energy or radiation absorption by the cells causes
negative changes (i.e. negative mutations or death). When these doses are
sufficiently low, vital processes inside the cells are stimulated and can create
positive changes. This paper proposes a common denomination for mechanisms of UV
and ionizing radiation when interacting with living cells, underlying both its
mitogenetic effect and radiation hormesis. Data from radon exposure in
chronically exposed nuclear workers, acutely exposed Hiroshima and Nagasaki
victims and observers of atmospheric nuclear explosions, combined with animal
results, present irrefutable evidence that low doses of IR are beneficial. As a
conclusion the author postulates the possibility of new methods of therapy
regarding the use of IR and mitogenetic radiation. This paper has been written to
encourage debate regarding possible future benefits that may be derived from low
level doses of IR exposure in the general population.
PMID- 10783490
TI - Colon heat and colon cancer.
AB - Epidemiological findings on the relation between foods and colon cancer are
inconsistent. Many, but far from all, found positive associations for meat and
fat and negative ones for vegetables and fruits. Explanations so far have focused
on direct biochemical conversions in the colon or transit time, but they remain
unable to explain the contradictory observations. One aspect grossly ignored has
been bacterially produced heat which is beyond somatic control. A present day
affluent lifestyle includes a more sedentary life, the strongest of all risk
factors for colon cancer, with more sitting and less diffusion of bacterial heat,
more fat and sugar, rich in energy and less of energy poor foods like cereals. A
temperature higher by less than 1 degrees C in the colon over decades may promote
tumour growth to a distinguishable extent.
PMID- 10783491
TI - Glutarimide: a carrier transporting drug through cell membranes.
AB - It is suggested that glutarimide moiety (2,6-piperidinedione) with the intact
imide group (OC-NH-CO) and substituted at alpha or beta position in the ring, is
acting as the carrier molecule (vector), which transports biologically active
substituents (functional groups) through cell membranes. The results obtained
from quantum chemical calculations and experimental studies indicate that
structural features and physicochemical properties of glutarimide moiety are
remarkably similar with those of uracil derivatives. Therefore, glutarimide drug
may interact with specific receptors involved in transport of uracil and thymine
nucleosides and it may easily cross biological membranes. (c) 2000 Harcourt
Publishers Ltd.
PMID- 10783492
TI - Parathyroid hormone may be a cancer promoter - an explanation for the decrease in
cancer risk associated with ultraviolet light, calcium, and vitamin D.
AB - Epidemiological studies reporting an inverse association between sunlight
exposure and risk for cancers of the breast, colon, and prostate, have not yet
been explained. Since ultraviolet (UV) light promotes dermal vitamin D
generation, studies suggesting that dietary calcium and vitamin D may likewise
have cancer-preventive activity are potentially of relevance. UV light, calcium,
and vitamin D have the common property of suppressing parathyroid hormone (PTH)
production; these considerations raise the possibility that PTH may have
promotional activity for certain cancers. PTH might function indirectly in this
regard, by increasing hepatic production of the progression growth factor IGF-I,
a likely cancer promoter. A more direct role is suggested by recent evidence that
many cancers express receptors for PTH/PTH-related protein; these receptors
mediate co-mitogenic and/or pro-invasive signals in some cancers. High risk for
previous or concurrent neoplasms has been reported in patients with parathyroid
adenomas. In light of the increase in cancer risk associated with hypertension,
it is notable that PTH levels are typically increased in salt-sensitive
hypertensives. Prospective case-control studies examining serum PTH in relation
to subsequent cancer risk appear warranted.
PMID- 10783493
TI - Toward a wholly nutritional therapy for type 2 diabetes.
AB - It may now be feasible to target specific supplemental nutrients to each of the
key dysfunctions which conspire to maintain hyperglycemia in type 2 diabetes:
bioactive chromium for skeletal muscle insulin resistance, conjugated linoleic
acid for adipocyte insulin resistance, high-dose biotin for excessive hepatic
glucose output, and coenzyme Q(10) for beta cell failure. Nutritional strategies
which disinhibit hepatic fatty acid oxidation (involving hydroxycitrate,
carnitine, pyruvate, and other adjuvants) may likewise prove beneficial - in the
short term, by decreasing serum free fatty acids and, in the longer term, by
promoting regression of visceral obesity. The nutrients and food factors
recommended here appear to be safe and well tolerated, and thus may have
particular utility for diabetes prevention.
PMID- 10783494
TI - The origins of western obesity: a role for animal protein?
AB - A reduced propensity to oxidize fat, as indicated by a relatively high fasting
respiratory quotient, is a major risk factor for weight gain. Increased insulin
secretion works in various ways to impede fat oxidation and promote fat storage.
The substantial 'spontaneous' weight loss often seen with very-low-fat dietary
regimens may reflect not only a reduced rate of fat ingestion, but also an
improved insulin sensitivity of skeletal muscle that down-regulates insulin
secretion. Reduction of diurnal insulin secretion may also play a role in the fat
loss often achieved with exercise training, low-glycemic-index diets,
supplementation with soluble fiber or chromium, low-carbohydrate regimens, and
biguanide therapy. The exceptional leanness of vegan cultures may reflect an
additional factor - the absence of animal protein. Although dietary protein by
itself provokes relatively little insulin release, it can markedly potentiate the
insulin response to co-ingested carbohydrate; Western meals typically unite
starchy foods with an animal protein-based main course. Thus, postprandial
insulin secretion may be reduced by either avoiding animal protein, or
segregating it in low-carbohydrate meals; the latter practice is a feature of fad
diets stressing 'food combining'. Vegan diets tend to be relatively low in
protein, legume protein may be slowly absorbed, and, as compared to animal
protein, isolated soy protein provokes a greater release of glucagon, an enhancer
of fat oxidation. The low insulin response to rice may mirror its low protein
content. Minimizing diurnal insulin secretion in the context of a low fat intake
may represent an effective strategy for achieving and maintaining leanness.
PMID- 10783495
TI - The worldwide controversy about the polymorphism of the vitamin D receptor gene
and bone mineral density.
PMID- 10783496
TI - Maternal serum alpha-fetoprotein and altitude.
AB - Maternal serum alpha-fetoprotein (MS-alphaFP) testing is widely used to screen
for fetal defects. MS-alphaFP concentrations are affected by a number of
variables such as gestational age, maternal weight, number of fetuses, race, and
insulin-dependent diabetes. Undefined geographic factors may also influence MS
alphaFP. We have examined the effect of altitude in a sample of 1063 MS-alphaFP
results selected to span a range of altitudes. The study sample was subjected to
linear regression with and without a term for altitude, and multiple-of-the
median (MoM) values were calculated before and after adjusting for altitude. The
median MS-alphaFP was found to decrease an average of 1 ng/mL for every 1100 ft
increase in altitude, a change approximately equivalent to that seen with an
increase in maternal weight of 6 lb. Adjusting for altitude resulted in the
reclassification of 36 of 1063 patient results (3.4%), although the clinical
utility of this adjustment remains unexamined.
PMID- 10783497
TI - Antisense antiviral agents: about the optimal approach.
AB - The vast majority of recent efforts to synthesize effective antisense
preparations for antiviral therapy have been made by using oligonucleotides,
agents able to inhibit only a relatively small portion of the viral genome. That
is the main reason why this approach is far from optimal. The optimal approach,
however, is the accomplishment of the total inhibition of the viral genome. Here,
a general protocol for preparation of the antisense antiviral agents with optimal
properties for in vivo application is proposed, irrespective of the viral genome
nucleotide sequence.
PMID- 10783498
TI - Adequate selection of anticancer agents: a task which can be fulfilled by
changing selection criteria.
AB - An analysis of anticancer agents' selection based on the effect on tumor cell
colony formation inhibition after exposure to the agent under investigation is
performed. The real significance of such a method, as well as the probable
negative clinical consequences of its use for screening of agents for cancer
therapy are pointed out. Also, principles of overcoming the inadequacy of tumor
cell clones' expansion inhibition tests and their equivalents are proposed.
PMID- 10783499
TI - Immunologic memory in the placenta: a lymphocyte recirculation hypothesis.
AB - The placenta is an immunologically unique organ where a balance between maternal
immunity and fetoplacental well-being must be maintained for successful pregnancy
to occur. The intervillous blood is important in this context, yet little is
known about local immunologic processes, particularly how placenta-specific
memory immune responses are maintained. Using malaria as an illustrative case, we
describe an hypothetical model in which recirculation of memory T lymphocytes
from the intervillous blood to local lymphoid tissue facilitates maintenance of
local memory immunity. This explains how memory cells might be retained when the
placenta is expelled at parturition and thus remain available for rapid recall
from the local lymphoid tissue to the intervillous space when exposure to the
same antigenic stimulus occurs in subsequent pregnancies. Study of cell-mediated
immunity to infections like malaria in the intervillous blood and the use of
animal models will be necessary to provide proof for this hypothesis.
PMID- 10783500
TI - Effects of electrostatic potentials generated on the surface of the skin by
wearing synthetic and semisynthetic fabrics on physical condition, mood and
behavior: role of acupuncture points.
AB - Synthetic and semisynthetic fabrics generate electrostatic potentials on the
surface of the skin. The author suggests that the effects of electrostatic
potentials on physical and psychological condition are mediated by acupuncture
points. The author further suggests that electrostatic charges on the surface of
the skin may affect virtually all physiological functions, mood, and behavior.
PMID- 10783501
TI - Pitfalls in the determination of common analytes in the critically ill.
AB - In the critically ill, the pre-analytical aspects of blood gas analysis still
require attention from the clinician. Sampling and transport remain critical
factors. Use of drugs may create analytical interferences for common analytes
like glucose and protein. Icterus may falsely reduce creatinine and albumin
values. Changes in the serum or plasma matrix (reduction of protein, increased
covolume of solutes, ...) may furthermore cause important effects on the
distribution of electrolytes. Enzyme activity measurements may be erroneous due
to lack of essential oligoelements or reducing substances. Immunoassays may
suffer from interferences caused by auto-antibodies. In case of hemolysis, a
careful interpretation of test results is mandatory.
PMID- 10783502
TI - From obesity to diabetes: why, when and who?
AB - Obesity is considered as the most important risk factor for type 2 diabetes. We
will briefly discuss why does obesity predispose to diabetes, when does diabetes
occur in obese subjects and who among obese individuals is particularly prone to
develop diabetes. Obesity, especially intraabdominal adiposity, is associated
with increased FFA plasma concentrations which exert a major negative effect on
insulin sensitivity at both muscular and hepatic sites. Various metabolic,
haemodynamic and hormonal theories have been proposed to explain insulin
resistance in obese subjects. A specific role of TNF-alpha has been recently
suggested. However, besides insulin resistance, defective insulin secretion is a
prerequisie for the development of overt type 2 diabetes. Both lipotoxicity and
glucotoxicity may initiate and perpetuate a vicious circle responsible for the
metabolic deterioration. Diabetes occurs as a late phenomenon in obesity and is
preceded by years of impaired glucose tolerance. The progression to diabetes is
heralded by an inability of the B cell to maintain its previously high rate of
insulin secretion in response to glucose in face of insulin resistance. This
propensity to develop type 2 diabetes may be genetically determined and/or
triggered by environmental factors. The evolution from obesity to diabetes
represents a continuum that progresses through different phases in which defects
in both insulin action and insulin secretion play a critical interaction and must
be looked at in concert.
PMID- 10783503
TI - Comparative in vitro activity of cefepime against strains isolated from intensive
care and haematology patients.
AB - The aim of the study was to evaluate cefepime, a "fourth generation"
cephalosporin, for its in vitro activity in comparison with 5 other broad
spectrum antibiotics against clinical isolates from ICU and haematology patients.
The strains were isolated from blood (8%), lower respiratory tract (41%), upper
respiratory tract (14%), urine (20%) and other sites (17%). They were divided
into: 28 non-inducible Enterobacteriaceae, 35 inducible Enterobacteriaceae, 20
non-fermenters, 10 S. aureus and 10 Streptococcus spp. The MIC-values were
determined by E-test. Overall, the rank order of susceptibility was cefepime
(93%), imipenem (90%), piperacillin-tazobactam (81%), ciprofloxacin (79%),
ceftriaxone (75%) and ceftazidime (74%). Only cefepime was able to inhibit all
inducible Enterobacteriaceae. Against Pseudomonas aeruginosa, cefepime had the
same activity as ceftazidime. With the exception of ceftazidime (65%), all beta
lactams demonstrated good activity against Gram positive cocci. The excellent
activity against most Gram negative and Gram positive pathogens suggests that
cefepime may be useful in the treatment of serious infections in the described
patient population.
PMID- 10783504
TI - Hereditary angioneurotic edema: review of the literature.
AB - Congenital C1-inhibitor deficiency, or hereditary angioneurotic edema (HAE), is a
rare autosomal dominant disease due to alterations in the C1 inhibitor gene that
results in a deficiency of antigenic and/or functional C1-INH. Affected patients
are heterozygous, and their deficiency is incomplete, many of them having up to
20% of the normal amount of the inhibitor. The disease is characterised by
recurrent, circumscribed, non-pitting, and non-pruritic subepithelial swellings
of sudden onset, which fade during the course of 48-72 hours, but can persist up
to 1 week. Lesions can be solitary or multiple and primarily involve the
extremities, larynx, face, and bowel wall. Bradykinin is believed to be the main,
but certainly not the sole, mediator responsible for the bouts of edema in HAE.
The diagnosis is suggested by family history, the lack of accompanying pruritus
or urticaria, the presence of recurrent gastrointestinal attacks of colics, and
episodes of laryngeal edema. Diminished C4 concentrations during symptomatic
periods are highly suggestive for the diagnosis. Further laboratory diagnosis
depends on demonstrating a deficiency of C1-INH antigen (type I) in most
kindreds, but some kindreds have an antigenically intact but dysfunctional
protein (type II) and require a functional assay to establish the diagnosis.
Prophylactic administration of either attenuated androgens or protease inhibitors
has proved useful in reducing frequency or severity of attacks. Infusions of a
vapour-heated C1-INH concentrate are safe and effective means of both preventing
and treating attacks. Nevertheless, this treatment is expensive and this extract
is not readily available. It is emphasised that administration of angiotensin
converting enzyme inhibitors is contraindicated in patients suffering from
protease inhibitor deficiency states.
PMID- 10783505
TI - Q fever after a journey in Syria: a diagnosis suggested by bone marrow biopsy.
AB - A Belgian patient developed Q fever after a journey in Syria. Coxiella burnetii
infection was diagnosed because of the presence of granulomas with a central
vacuole in a bone marrow biopsy. During doxycycline treatment all his symptoms
disappeared.
PMID- 10783507
TI - [Rieger's nasal flap. History, technical refinements and indications].
AB - Rieger's flap, described by Rieger as a nasal rotation flap, has often been given
other names and descriptions in the literature. We consequently felt an overview
of the development, characteristics and technique of Rieger's flap was in order,
with the goal of helping surgeons use it to best avail. Rieger's flap is
irreplaceable for reconstructing defects of the lower third of the nose located
on or near the midline. Variants of Rieger's flap can be used to treat defects
located higher up on the nose. Four cases are reported to illustrate these
indications.
PMID- 10783506
TI - Multidrug-resistant tuberculosis spondylitis.
AB - We report a case of multidrug-resistant spinal tuberculosis complicated by
epiduritis and paraspinal abscess in a 68-year-old black woman. Multidrug
resistant tuberculous spondylitis is still rare in Belgium. Two others cases were
reported from 1992 to 1997. The optimal therapy is not standardized and the
mandatory duration of treatment is not known. Clinical presentation, radiological
findings, and treatment are presented. The need for prompt diagnosis and optimal
therapy is emphasized.
PMID- 10783508
TI - [Homage to Leon Tripier. Description of the first musculocutaneous flap and
current indications].
AB - The double pedicle flap taken from the upper lid was described for the first time
in 1888 by Tripier. To our knowledge, it is the first case of reconstruction by a
myocutaneous flap described in the literature. Other authors subsequently
modified the first description. The same flap taken with a single inner pedicle
is now usually employed. For the authors, the Tripier's flap, with a double and
permanent pedicle, still has some indications in eyelid reconstruction.
PMID- 10783509
TI - [Indications for the Schmid-Meyer frontal-temporal flap for nasal reconstruction.
Four clinical cases].
AB - The fronto-temporal flap described by Schmid and modified by Meyer is a tubular
flap with an internal supraciliary pedicle which allows the transposition of the
temporal skin with the addition of ear cartilage on the tip of the nose or the
ala nasi. This meticulous reconstruction requires four stages which are workable
under local anesthesia. Four clinical cases allow to specify the advantages and
the drawbacks of this technique. They place this technique in the therapeutic
possibilities between the composite grafts and various local and distant flaps.
PMID- 10783510
TI - [Survivorship of breast implants used in breast reconstruction. 949 implants].
AB - The authors present from a series of 949 implants their method to calculate the
life span of a mammary implant in the framework of breast reconstruction after
cancer. In this statistical study, they have calculated the median life span of
breast implants (loss of half of staff) by distinguishing it according to each
type of implant (content, brand, indication...). The global median life span of a
breast implant is 127 months. The median life span of a silicone gel-filled
implant is superior than a saline implant because the frequency of deflation of
saline implants is more important than the first one, despite that the real
rupture percentage of silicone gel-filled implants is under-evaluated by the
number of asymptomatic rupture. For saline implants, the median life span is
clearly decreased by the initial under-inflation (108 months against 127 months)
doubling the secondary deflation risk. In this series, the authors have been able
to compare the evolution of implants according to their initial indication
(reconstruction or aesthetic) and sometimes at a same patient, they have not
observed significant difference of the median life span over a period of five
years for an implant used in breast reconstruction after cancer or for an implant
used in symmetricalization. In this series, the life span of saline implants is
significant different in function of the brand of the implant demonstrating the
comparative study usefulness by brands.
PMID- 10783511
TI - [The modiolus. Comparative anatomy, embryological and physiological review,
surgical importance].
AB - Monkeys, imitators of man's gesture never shared smile with him and their facial
expressions only result in grimaces. Study of animal anatomy may explain why
subtle expressions of the lips are a more man's special gift than laughter. These
fine movements are related to a subcutaneous muscular structure termed modiolus,
which is the meeting point of muscles involved in the motion of mouth and
comparative anatomy shows this structure to be better defined in Man than in
other primates. Embryologically, muscles that form the modiolus derive from a
cellular concentration in the region of the second branchial arch. It is then
logical to see these muscles converge to the corner of the mouth to form the
modiolus, as they emerge from a common area. Functioning of the modiolus is
complex, as its position may change many times in a minute to allow the
orbicularis oris muscle to take any position and do any movement as if it was
inserted on bone. With its complex physiology, the modiolus is of critical
importance in the subtle expressions of the lips and must be preserved or
reconstructed when performing repair of full-thickness tissue defects of lips.
PMID- 10783512
TI - [Eyelid sebaceous carcinoma. A case report with literature review].
AB - Sebaceous carcinoma of the eyelids is a rare malignancy of which most cases
require extensive excision followed by usually complete eyelid reconstruction. We
report a case developed from the Meibomius glands of the lower eyelid. Complete
excision was achieved by removing the entire eyelid 'en bloc'. Reconstruction was
with a composite, chondromucosal septal graft layered on an upper eyelid,
musculocutaneous, transposition flap based on a lateral pedicle. After a brief
review of the relevant literature, the advantages and disadvantages of the
various methods of complete lower eyelid reconstruction are discussed.
PMID- 10783513
TI - [Radial antibrachial islet flap based on distal perforating arteries. A clinical
case].
AB - The frequency of the hand trauma involving tissue losses generated the research
for developing new technical solutions more simple and economic. The regional
flaps, such as the distal pedicle Chinese flap, are usually surgeon's first
choice whenever the local resources are over passed. Still, this type of Chinese
flap would claim a major disadvantage as they involve the sacrifice of a vascular
axis of the hand, sometimes even the dominant one. The operating team, would be
able to avoid this inconvenience when using distal perforators based-on
antibrachial radial flap; moreover, this technique would allow the covering of
the substance losses, as far as the metacarpophalangeal joints. The authors
report a clinical case.
PMID- 10783514
TI - [From a single vertical scar to vertical mammaplasty. From Louis Dartigues (1869
1940) to Claude Lassus (1933)].
AB - The cutaneous sequelae left by mammaplasties have always constituted a major
problem as well for the patients as for the surgeons. Since the turn of the
century and the birth of modern mammary corrections, surgeons have tried to
reduce these scars, while avoiding the impairment of the vascularisation of the
mammary gland, the nipple-areola complex and the skin. L. Dartigues proposed, in
1924, the use of a single subareolar vertical scar for the correction of limited
mammary ptosis. F. Lotsch introduced, in 1923, the rudiments of the future
vertical mammaplasty by associating a peri-areolar scar to the single vertical
subareolar scar. In 1971, C. Lassus, who had become interested and had been using
Lotsch's technique since 1964, abandoned the technique for a while, but returned
to these basic technique of Lotsch which he modified over the years and made it
applicable in 1980 to ptosed and most hypertrophied breasts. This article is also
concerned with the historic evolution of the scars left by mammary corrections
and with the mastopexy procedures.
PMID- 10783515
TI - [Medical demographics and plastic surgery in France: current situation and
projections].
PMID- 10783517
TI - Photochemical and chemical oxidation of mexiletine and tocainide. Structure
elucidation of the major products.
AB - Mexiletine (mex) and tocainide (toc) are antiarrhythmic drugs of closely related
structure. Several degradation products are formed by interaction with both light
and oxidizing agents in the case of mex, and only by oxidants with toc. On the
basis of the identified structures, the decomposition reactions can be classified
into two types (Scheme 1). Type I is an oxidative cyclization reaction producing
the oxazepine derivative 1 from mex and the diazepine derivative 3 from toc. In
reaction type II side chain oxidized products (2 or 4 and 5) are formed. While
tocainide.HCl has proved to be photostable, in solid mexiletine HCl the oxazepine
derivative was observed after several days' exposure to direct sunlight. The
pharmacopoeias (Ph.Eur.3, USP 23), however, do not prescribe light-protection for
mex.HCl.
PMID- 10783516
TI - Preparation of thieno[3,2-h]cinnolinones as matrix metalloproteinase inhibitors.
AB - A new series of thieno[3,2-h]cinnolinone analogues was synthesized which is
structurally related to 2,3,4,4a,5,6-hexahydrothieno [3,2-h]cinnolin-3-one 1, a
weak inhibitor of the matrix metalloproteinase MMP-8 (human neutrophil
collagenase). Preliminary SAR studies have shown that while C4a-methyl, C7
acetylamino, C7 and C8-nitro substitution, and C4-C4a olefination provided no
increase in activity relative to 1, C8-acetylamino substitution as in 5 and 8 was
favourable. Moreover, to predict how the thieno[3,2-h]cinnolinone inhibitors
might bind to MMP-8, the unsubstituted compound 9 was docked into the MMP-8
crystal structure. These studies revealed that inhibitor 9 does not seem to be
able to coordinate the catalytically-active zinc ion but preferably interact with
the peptide-binding region of the active site.
PMID- 10783518
TI - Design and synthesis of some oxadiazolyl, thiadiazolyl, thiazolidinyl, and
thiazolyl derivatives of 1H-pyrazole as anti-inflammatory antimicrobial agents.
AB - Four series of 1H-pyrazole derivatives have been synthesized. The first series
was prepared by cyclization of the intermediate 3-(5-bromo-2-thienyl)-1-phenyl-1H
pyrazole-4-carbaldehyde aroyl-hydrazone 4a-c with acetic anhydride to afford the
corresponding oxadiazoline derivatives 5a-c. The other series were prepared by
the cyclization of the intermediate 3-(5-bromo-2-thienyl)-1-phenyl-4-substituted
thiocarbamoylhydrazonomethyl-1H-pyrazole 6a-c with acetic anhydride, ethyl
bromoacetate or phenacyl bromide giving rise to 3-(5-bromo-2-thienyl)-1-phenyl-4
[3-acetyl-5-(N-substituted acetamido)-2,3-dihydro-1,3,4-thiadiazol-2-yl]-1H
pyrazoles 7a-c, 3-(5-bromo-2-thienyl)-1-phenyl-4-(3-substituted- 4-oxothiazolidin
2-ylidenehydrazonomethyl)-1H-pyrazoles 8a-c, or 3-(5-bromo-2-thienyl)-1-phenyl-4
(3-substituted-4- phenyl-2,3-dihydrothiazol-2-ylidenehydrazonomethyl)-1H-pyraz
oles 9a-c respectively. Some of these compounds showed anti-inflammatory,
antibacterial or antifungal activities comparable to that of Proquazone,
Ampicillin, or Clotrimazole respectively.
PMID- 10783519
TI - Studies on the chemistry of thienoannelated O,N- and S,N-containing heterocycles.
Part 19: thieno[2,3-b][1,4]thiazines with calcium antagonistic and potassium
opening activities.
AB - In this study novel substituted 6-benzyl-thieno[2,3-b][1,4]thiazines with an urea
moiety were synthesized. Structural modifications of the amino side chain were
carried out with the aim of finding tissue specific compounds. The effects on
papillary muscles, right atria, aortic strips, and terminal ilea were
investigated. Compounds 10c and 10d showed the most potent negative inotropic
effect. The calcium antagonism of all derivatives occurred in a non-competitive
manner, which may indicate that they also have potassium channel opening
activities.
PMID- 10783520
TI - Hypochlorous acid, a major oxidant produced by activated neutrophils, has low
effect on two pyridobenzazepine derivatives, JL 3 and JL 13.
AB - JL 13 (5-(4-methylpiperazin-1-yl)-8-chloro-pyrido[2,3-b]- [1,5]benzoxazepine
fumarate) and JL 3 (10-(4-methylpiperazin-1- yl)pyrido[4,3
b][1,4]benzothiazepine), two pyridobenzazepine derivatives structurally related
to clozapine, were selected for further development. Due to their structural
similarity to clozapine, they are haunted by the spectre of clozapine-induced
agranulocytosis. In a previous study, JL 13 was shown to be less sensitive to
oxidation than clozapine. In the present paper, using an in vitro procedure, we
report the effect of hypochlorous acid (HOCl), a major in vivo oxidant, on both
drugs. It appears that the oxidations of JL 3 and JL 13, unlike clozapine, are
very slow and little secondary product is formed. Moreover, in contrast to
clozapine, the products that were formed are not reactive and thus do not react
with glutathione or N-acetylcysteine. Thus, if, as postulated for clozapine, drug
induced agranulocytosis is due to a reactive metabolite formed by neutrophils or
their precursors, JL 3 and JL 13 would not be expected to cause the same adverse
reaction.
PMID- 10783521
TI - Does [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]-
dichloroplatinum(II) act on the hormone-sensitive, murine breast cancer as a
biological response modifier? Part 1: The MXT-M-3.2 breast cancer stimulates the
growth of an identical second graft; [meso-1,2-bis(2,6-dichloro-4
hydroxyphenyl)ethylenediamine]dichloroplat inum (II) inhibits this process.
AB - The MXT-M-3.2 breast cancer implanted into female B6D2F1 mice accelerates the
growth of an identical second tumor. This process is inhibited by [meso-1,2
bis(2,6-dichloro-4-hydroxyphenyl) ethylenediamine]dichloroplatinum(II). The
possible modes of action of this compound as a biological response modifier are
discussed.
PMID- 10783522
TI - Protecting the legacy: the nurse-patient relationship and the therapeutic
alliance.
PMID- 10783523
TI - Effect of cognitive therapy on depression in rural, battered women.
AB - The purpose of this pilot study was to explore the feasibility of a future
randomized trial to determine the effect of a 20-week cognitive therapy
intervention (INSIGHT) on depression in battered women. An experimental, 2 group
pretest and posttest design was used in this study with 18 rural women who have
experienced battering and 9 rural women who have not. The results of this study
lend feasibility to other studies using INSIGHT with a larger, randomized sample.
The 50% attrition rate for the battered women suggests the need for phase
specific sensitivity in future research.
PMID- 10783524
TI - Predicting substance abuse and comorbidity in rural women.
AB - Substance abuse in women is underdiagnosed. Moreover, women are more likely to
have a primary comorbid psychiatric disorder that complicates diagnosis and
treatment. The purpose of this study was to identify risk factors that would
predict substance abuse and primary comorbid psychiatric disorders in rural
women. Discriminant function analysis identified 2 factors, alcohol beliefs and
threats of minor violence, which correctly identified substance abusing women
from nonsubstance abusing women, and women with nonsubstance use psychiatric
disorders from those with no psychiatric disorder. These 2 functions correctly
classified 69% of women in the study. Psychiatric diagnoses and nursing
implications are discussed.
PMID- 10783526
TI - Symptom development in bulimia nervosa: a comparison of women with and without a
history of anorexia nervosa.
AB - Identifying women at risk for developing bulimia nervosa (BN) is an important
area of study for psychiatric-mental health nurses. Of those who develop BN, a
large proportion of women have been diagnosed earlier with anorexia nervosa (AN).
It has been posited that women who are treated for AN are often only partially
recovered. Although their weights become clinically acceptable, they often
continue to restrict food; this typically leads to a binge eating and purging
cycle and the development of BN. A history of AN is viewed as a possible risk
factor for the development of BN. This study compared women seeking treatment for
BN with a prior history of AN, and those without this history on selected
variables. A profile emerged and is described supporting a distinct subgroup with
prior AN. Findings from this study have implications for early detection of and
extended follow-up care after treatment for AN.
PMID- 10783525
TI - African American grandmothers' perceptions of caregiver concerns associated with
rearing adolescent grandchildren.
AB - In 1996, grandparents were the sole providers of care for 269,000 grandchildren.
Research findings indicate that grandmothers are usually the primary caretakers
of grandchildren. Previous issues associated with raising grandchildren vary, but
usually relate to the grandparents' health, financial concerns, or lack of social
support. This qualitative descriptive study was designed to describe African
American grandmothers' perceptions about the burdens of raising adolescent
grandchildren. Using this approach, the researchers were able to study the
richness and diversity of the grandmothers' perceptions. Data were collected from
35 grandmothers through a focus group (n = 7) and during a 4-day intervention
research study (n = 28) entitled "Grandmother-Grandchild Health Promotion
Program." Numerous concerns were voiced by both groups, but those stated most
frequently were associated with the well-being of grandchildren (grandchildren's
sexual behavior, potential drug use, and potential risk of encountering violence)
and relational conflicts with adult children. Unexpected findings were the
absence of stated concerns associated with the grandmothers' financial situation
or health. Recommendations for intervention, clinical practice, and research are
discussed.
PMID- 10783527
TI - Aversiveness of traditional psychiatric patient restriction.
AB - This article is a literature review of traditional psychiatric patient
restriction and the consequential harm that the patient experiences. Though the
obtainment of theoretical objectives and short-term overt behavioral results
appear to be gained through psychiatric constraint measures, injurious effects to
the patient have been recorded with resultant impediment to the restoration of
psychological health. This article asserts the necessity for the use of
alternative measures, which have been shown to be successful in restoring control
while maintaining and promoting the dignity and psychological health of the
patient.
PMID- 10783528
TI - Cost-effectiveness analysis of case management versus a routine community care
organization for patients with chronic schizophrenia.
AB - This article reports the economic analysis of a study on the implementation of
case management in the Community Psychiatric Nursing Service (CPNS) caring for
chronic schizophrenic clients in Hong Kong. The purpose of the study was to
compare the outcome of case management service with the conventional practice
CPNS. Sixty-two subjects participated in the analysis. Cost-effectiveness
analysis showed that case management costs more in Hong Kong $3,600 (US$450) per
person and that over a 5-month period, case management was associated with
improvements in psychological and functional outcomes and patient satisfaction.
The results of this study will inform policy makers about resource allocation and
policy development in the implementation of case management for the care of
mentally ill clients.
PMID- 10783529
TI - Origin of Finnish mutations causing aspartylglucosaminuria.
AB - Aspartylglucosaminuria (AGU) is an autosomal recessive lysosomal storage disease
highly enriched in Finland where one mutation AGUFin major is responsible for 98%
of the AGUFin alleles. Another mutation AGUFin minor has been identified in eight
compound heterozygote patients who have AGUFin major mutation in their other
allele. In addition four compound heterozygote patients have AGUFin major in one
allele and unknown AGUFin mutation in the other allele. To study the origin of
these mutations the haplotype analysis was performed on six patients with AGUFin
minor mutation and four patients with unknown AGUFin mutation using nine
microsatellite markers on the 7.6 cM chromosome region on 4q28-4qter. The
haplotype data suggest that one founder mutation is responsible of all AGUFin
minor alleles. Allelic association was also observed in AGUFin major chromosomes.
Patients with unknown mutation did not share a common haplotype and therefore
most likely have different origin.
PMID- 10783530
TI - Inheritance of species differences in female receptivity and song requirement
between Drosophila virilis and D. montana.
AB - Females of two Drosophila virilis group species, D. virilis and D. montana, have
different requirements for the courting males. In the present study we have
examined species differences in female receptivity and male courtship song
requirement using females' acceptance signal instead of copulation for measuring
female readiness to mate. Behavior of D. virilis and D. montana females and F1
and backcross hybrid females was observed in a single-pair courtships with D.
virilis and D. montana males and normal and wingless (mute) F1 hybrid males. D.
virilis females were very receptive and they commonly accepted the courtship of
males unable to produce courtship song. D. montana females, on the contrary, had
a low receptivity and these females accepted the courting male only after hearing
his song. Interspecific F1 and backcross (BCm) females resembled D. virilis more
than D. montana in their receptivity. These females, however, resembled D.
montana in their song requirement. These findings suggest that female song
requirement and female receptivity are determined by different genetic factors.
PMID- 10783531
TI - Autosomal and sex chromosomal polymorphisms with multiple rearrangements and a
new karyotype in the genus Rhipidomys (Sigmodontinae, Rodentia).
AB - Two diploid numbers and five karyomorphs were found in ten specimens of
Rhipidomys (Sigmodontinae, Rodentia) from three states in Brazil: 2n = 50 from
Amazonas, and 2n = 44 from Mato Grosso and Bahia. CBG, GTG, and RBG-banding and
Ag-NOR analyses were performed, as well as fluorescence in situ: hybridization
with (T2AG3)7 probes. The new diploid number of 2n = 50 was associated with two
different fundamental numbers (FN = 71 and 72) as a result of pericentric
inversions and addition/deletion of constitutive heterochromatin. The samples
from two localities (Aripuana and Vila Rica) in the state of Mato Grosso shared
2n = 44 and FN = 52, but their karyotypes differed because of pericentric
inversions. Although the single specimen from Bahia had the same diploid number
as the samples from Mato Grosso, its karyotype and FN were completely
distinctive. Karyological comparison of GTG-banding patterns revealed total
homology between the karyotypes of the specimens from Bahia and Mato Grosso,
implying the occurrence of 14 autosomal pericentric inversions. Homologies
between ten of the autosomes in the karyotypes with 2n = 50 (FN = 72) and 2n = 44
(from Vila Rica, MT) were demonstrated. The differentiation between 2n = 44 and
2n = 50 involved five pericentric inversions, addition/deletion of constitutive
heterochromatin in both autosomes and sex chromosomes, at least one Robertsonian
rearrangement and other not detected rearrangements. Despite the remarkable
number of rearrangements, interstitial telomeric sites (ITS) were not detected.
Sex chromosomes also exhibited polymorphism in size and morphology.
PMID- 10783533
TI - Genomic compatibility between two phyllotine rodent species evaluated through
their hybrids.
AB - In order to investigate the genomic compatibility between allopatric rodent
species, Phyllotis darwini and Phyllotis magister, we have studied several
cytogenetic and reproductive features of their laboratory hybrids. Of thirty-one
pairings between species, only five were successful, producing eleven newborns.
Like parents, hybrids had 38 metacentric chromosomes, except for the
subtelocentric Y chromosome inherited from P. magister. There was almost total C
and G band correspondence between homeologous autosomes. However, parental sex
chromosomes had different morphology, C and G bands. Ag-NOR bands appeared as
small telomeric Ag+ regions, distributed in four chromosomal pairs of darwini,
three of magister and four homeologous chromosomes of the hybrids. The three
forms had similar indexes of NOR activity per cell, in spite of the variability
in NOR expression which was always detected. Usually, only one member of parental
homologous chromosomes showed AgNOR+; nevertheless, both homeologous chromosomes
were active in many hybrid cells. The frequencies of cells that expressed their
ribosomal genes in the two homologous or homeologous NOR chromosomes were similar
in parental and hybrid cells. These results strongly suggest that ribosomal genes
of both parental genomes would function codominantly in the hybrids. The gonad
histological and morphometric analyses showed that hybrids conformed to Haldane's
rule, since females were fertile and males were infertile. Our results indicate
that P. darwini and P. magister genomes can function in relative harmony and
compatibility when they are placed together in their laboratory generated
hybrids, suggesting that these species have few genetic differences, probably
because they have recently diverged.
PMID- 10783532
TI - Ribosomal RNA gene loci and silver-stained nucleolar organizer regions associated
with heterochromatin in Alaskan char Salvelinus malma and chum salmon
Oncorhynchus keta.
AB - Nucleolus-forming 5.8S, 18S and 28S ribosomal RNA gene (rDNA) loci were assigned
by fluorescence in situ hybridization (FISH) to the distal half of the short arms
of a large-sized submetacentric pair in the Alaskan char (Salvelinus malma) and
to the distal region of the long arms of a medium-sized submetacentric pair in
the chum salmon (Oncorhynchus keta), respectively. In each species, heteromorphic
FISH signals, spanning whole satellite region and secondary constriction, imply
an intraspecific variation in the size of rDNA loci. Size variation of silver
stained nucleolar organizer regions (AgNORs) was also apparent between or within
the assigned rDNA loci in each species, suggesting a possible inter- or
intralocus inactivation of rDNAs. C-band positivity of assigned rDNA loci and
AgNORs unequivocally showed their association with heterochromatin in these
species.
PMID- 10783534
TI - Applicant self-selection: correlates of withdrawal from a multiple hurdle
process.
AB - The authors examined applicant self-selection from a multiple hurdle hiring
process. The relationships of the selection status of 3,550 police applicants
(self-selected out prior to 1 of the hurdles, passing, or failing) and
perceptions of the organization, commitment to a law enforcement job,
expectations regarding the job, employment status, the need to relocate, the
opinions of family and friends, and perceptions of the hiring process were
examined. Differences between those who stayed in the process and those who self
selected out were observed in most areas, and those who self-selected out at
early stages differed from those self-selecting out at later stages. African
Americans' and women's perceptions also differed from the majority group,
indicating some of the difficulties an organization faces in attempting to
diversify.
PMID- 10783535
TI - Adapting the cognitive interview to enhance long-term (35 years) recall of
physical activities.
AB - The cognitive interview (CI) was modified for use in an epidemiological study in
which respondents were asked to recall their daily physical activities from the
distant past (35 years ago). In comparison to a traditional epidemiological
interview, the CI elicited many more responses and also more precise responses.
Several practical costs, however, were incurred by the CI: additional time to
train interviewers and to conduct interviews and difficulties in coding the
responses. The costs and benefits of conducting the CI are addressed, along with
conceptual and methodological challenges. The article ends with an existential
question: Is the CI a singular technique if it can be modified so radically for
different settings?
PMID- 10783536
TI - Interindividual differences in intraindividual changes in proactivity during
organizational entry: a latent growth modeling approach to understanding newcomer
adaptation.
AB - Intraindividual change over time is the essence of the change phenomenon
hypothesized to occur in the individual newcomer adaptation process. Many
important adaptation questions cannot be answered without an adequate
conceptualization and assessment of intraindividual change. Using a latent growth
modeling approach to data collected from 146 doctoral program newcomers over 4
repeated measurements spaced at 1-month intervals, the authors explicitly modeled
interindividual differences in intraindividual changes in newcomer proactivities
(information seeking, relationship building) and proximal adaptation outcomes
(task mastery, role clarity, social integration) during organizational entry.
Results indicated that changes in proactivity may be related to newcomer
characteristics and adaptation outcomes in interesting ways that have not been
previously examined.
PMID- 10783537
TI - A longitudinal study of relations between job stressors and job strains while
controlling for prior negative affectivity and strains.
AB - Interpretation of observed relations between job stressors and job strains in
cross-sectional surveys is often ambiguous because of possible 3rd variables
(both stable background factors, such as personality, and transitory occasion
factors, such as mood). In this longitudinal study, negative affectivity (NA) and
strains were assessed both in college and later on the job. Stressors were
assessed only on the job. Evidence was found that some background factors
affected measures of job stressors and job strains in that college measures were
significantly related to subsequent measures on the job. Relations between job
stressors and job strains, however, were in most cases not affected significantly
when prior strains and NA were controlled for. Furthermore, the results suggested
that NA measures are subject to occasion factors.
PMID- 10783538
TI - Selection based on merit versus demography: implications across race and gender
lines.
AB - In a replication and extension of the study by M. E. Heilman, M. C. Simon, and D.
P. Repper (1987), 201 undergraduates participated in a simulation in which they
experienced differing selection procedures and outcome feedback. Selection
procedures did not have the deleterious effects on women that were found
previously. Instead, race interacted with gender to moderate this relationship,
and outcome played a significant role in participant self-evaluations. Black
participants rated their leadership ability highest when both chosen
preferentially and given negative outcome feedback, apparently because of a
desire to maintain positive self-esteem. The latter explanation was supported in
a follow-up study in which undergraduates (n = 80) worked in groups and received
negative outcome feedback from either a racially similar or racially different
experimenter. Theoretical and practical implications relating to diversity and
self-appraisal management are discussed.
PMID- 10783539
TI - Conscientiousness and agreeableness as predictors of rating leniency.
AB - The authors studied the relationship between the Big Five personality factors and
rating elevation among 111 students making peer evaluations. It was hypothesized
that Conscientiousness (C) scores would be negatively correlated with rating
level and that Agreeableness (A) scores would be positively correlated with
rating level. We further predicted that individuals who were low on C and high on
A would produce the most elevated ratings. As predicted, A scores were positively
related to rating level (.33, p < .01) and C scores were negatively correlated
with rating level (-.37, p < .01). Using the strong hypothesis test (P. Bobko,
1986), the authors found that ratings by low C and high A individuals were more
elevated than all other groups of students combined (p < .01).
PMID- 10783540
TI - Personality and job satisfaction: the mediating role of job characteristics.
AB - This study tested a model of the relationship between core self-evaluations,
intrinsic job characteristics, and job satisfaction. Core self-evaluations was
assumed to be a broad personality concept manifested in 4 specific traits: self
esteem, generalized self-efficacy, locus of control, and low neuroticism. The
model hypothesized that both subjective (perceived) job characteristics and job
complexity mediate the relationship between core self-evaluations and job
satisfaction. Two studies were conducted to test the model. Results from Study 1
supported the hypothesized model but also suggested that alternative models fit
the data well. Results from Study 2 revealed that core self-evaluations measured
in childhood and in early adulthood were linked to job satisfaction measured in
middle adulthood. Furthermore, in Study 2 job complexity mediated part of the
relationship between both assessments of core self-evaluations and job
satisfaction.
PMID- 10783541
TI - Action-state orientation: construct validity of a revised measure and its
relationship to work-related variables.
AB - Data from 6 studies (N = 945) were combined to examine the factor structure and
construct validity of J. Kuhl's (1994a) measure of action-state orientation, the
Action Control Scale (ACS). Initial confirmatory factor analysis (CFA) of 4
models showed poor fit with the data. Items that did not perform well were
dropped, and the 4 CFA models were retested, resulting in support for a 3-factor
solution corresponding to the Preoccupation, Hesitation, and Volatility
subscales. Regression analyses demonstrated that the revised ACS subscales
measure a construct distinct from cognitive ability and personality. The revised
subscales showed differential statistically significant relationships with (a)
self-regulatory and self-focus variables and (b) job attitudes and ratings of job
performance. The authors conclude that action-state orientation is a construct
relevant to applied settings and that future research should further examine this
construct.
PMID- 10783542
TI - "I knew we would win": hindsight bias for favorable and unfavorable team decision
outcomes.
AB - This study examined hindsight bias for team decisions in a competitive setting in
which groups attempted to outperform each other. It was anticipated that, because
of self-serving mechanisms, individuals would show hindsight bias only when
decision outcomes allowed them to take credit for their own team's success or to
downgrade another team for being unsuccessful. MBA students playing a market
simulation game made hindsight estimates regarding the likelihood that either
their own or another team would perform well. Consistent with a self-serving
interpretation, when decision outcomes were favorable individuals evaluating
their own team, but not those evaluating another, showed hindsight bias. When
outcomes were unfavorable individuals evaluating their own team did not show
hindsight bias, but those evaluating another team did. Discussion focuses on
implications of hindsight bias in team decision-making settings.
PMID- 10783543
TI - The influence of shared mental models on team process and performance.
AB - The influence of teammates' shared mental models on team processes and
performance was tested using 56 undergraduate dyads who "flew" a series of
missions on a personal-computer-based flight-combat simulation. The authors both
conceptually and empirically distinguished between teammates' task- and team
based mental models and indexed their convergence or "sharedness" using
individually completed paired-comparisons matrices analyzed using a network-based
algorithm. The results illustrated that both shared-team- and task-based mental
models related positively to subsequent team process and performance.
Furthermore, team processes fully mediated the relationship between mental model
convergence and team effectiveness. Results are discussed in terms of the role of
shared cognitions in team effectiveness and the applicability of different
interventions designed to achieve such convergence.
PMID- 10783544
TI - Employee attitude surveys: examining the attitudes of noncompliant employees.
AB - Employees (N = 194) from a wide variety of organizations participated in this
study aimed at describing the attitudes of individuals who refuse to respond to
an employee survey request (noncompliants). Noncompliants, in comparison with
those individuals who would comply with the survey request, possessed greater
intentions to quit, less organizational commitment, and less satisfaction toward
supervisors and their own jobs. Noncompliants also possessed more negative
beliefs regarding how their organization handles employee survey data (e.g., does
not act on survey data). No significant differences were found for work-related
demographic variables, satisfaction with pay, and satisfaction with promotion
opportunities. Implications for survey research are discussed along with methods
to address nonresponse and noncmpliance.
PMID- 10783545
TI - The effect of organizational structure on perceptions of procedural fairness.
AB - This study explored the relationship between 3 dimensions of organizational
structure--centralization, formalization, and size--and perceptions of procedural
and interactional fairness. Data from 11 organizations (N = 209) indicated that,
as predicted, centralization was negatively related to perceptions of procedural
fairness, and organizational size was negatively related to interactional
fairness. However, contrary to predictions, formalization was not related to
perceptions of procedural fairness. Results suggest that organizational structure
and design should play a more prominent role in our thinking about organizational
fairness.
PMID- 10783546
TI - Does computerizing paper-and-pencil job attitude scales make a difference? New
IRT analyses offer insight.
AB - The measurement equivalence of 2 scales of the Job Descriptive Index (JDI; P. C.
Smith, L. M. Kendall, & C. L. Hulin, 1969), the Supervisor Satisfaction scale and
the Coworker Satisfaction scale, was examined across computerized and paper-and
pencil administrations. In this study, employees in 2 organizations (N = 1,777)
were administered paper-and-pencil versions of the scales, and employees in a
third organization (N = 509) were administered a computerized version. A newly
developed item response theory (IRT) technique for examining differential test
functioning (N. S. Raju, W. J. van der Linden, & P. F. Fleer, 1995) was used to
examine measurement equivalence across media. Results support the measurement
equivalence of the JDI Supervisor and Coworker scales across administration
media. The implications of these findings for both practitioners and
organizational researchers are discussed.
PMID- 10783547
TI - Ancient Pygmalion joins contemporary management: a meta-analysis of the result.
AB - To determine the existence and relative magnitude of the Pygmalion effect among
adults within management contexts, a meta-analysis of 17 relevant studies (58
effect sizes; N = 2,874) was conducted to provide an estimate of the population
mean effect size and variation from Pygmalion interventions. Performance measures
in these studies included exam scores, performance appraisals, and physical
output. Results indicate that Pygmalion effects can be fairly strong within some
management contexts (average d = 1.13) but may vary widely depending on
moderating variables. Specifically, results were stronger in the military, with
men, and when involving persons for whom low expectations were initially held.
Findings also highlight the need for more research in ongoing work contexts (vs.
training) and in for-profit organizations (vs. the military). Suggestions are
given to help overcome possible hurdles in conducting research in these areas.
PMID- 10783548
TI - [What is your diagnosis? Trigeminal neuralgia caused by a hematoma in Meckel's
cavity].
PMID- 10783549
TI - [Low visual acuity, disorders of the visual field: how to adapt the imaging of
optical pathways to clinical practice?].
PMID- 10783550
TI - [Vertebro-epidural lumbosacral vascular malformations. An unusual cause of lumbo
sciatic pain].
AB - Sciatica is most commonly caused by nerve root compression secondary to herniated
disk. Rarely, it can be due to a lumbosacral vascular malformation. We present
five cases with such a malformation, presenting as a chronic lumboradiculagia.
The patients were explored with computed tomography, MRI and selective spinal
angiography. Polymorphic anatomic and hemodynamic aspect of these cases are
reported: 1. One vertebral hemangioma with epidural extension; 2. Three purely
epidural malformations: a) one epidural cavernous hemangioma, b) one epidural
arteriovenous malformation, c) one epidural varix; 3. One paravertebral
arteriovenous fistula with epidural venous drainage. Diagnosis of these rare
malformations may be difficult. A multiplanar cross-sectional magnetic resonance
and computed tomography scan with contrast enhancement can show characteristic
abnormalities and may assist in recognition these malformations. Selective spinal
angiography confirms the diagnosis, allows to classify the malformation and is
required to evaluate endovascular therapeutic possibilities.
PMID- 10783551
TI - Hemodynamic changes around cerebral arteriovenous malformation before and after
embolization measured with PET.
AB - To estimate the changes in regional cerebral blood flow (rCBF) around cerebral
arteriovenous malformation (AVM) before and after embolization, 6 patients with
AVM were sequentially examined with positron emission tomography (PET). PET
depicted the remodeling of rCBF in the ipsilateral hemisphere of AVM after
embolization. Decrease of rCBF in the ipsilateral hemisphere was also detected in
patients with focal symptoms before embolization, and improvement of clinical
symptoms after embolization corresponded to disappearance of rCBF decrease. PET
can detect hemodynamic changes after embolization, and has a possibility to
estimate the effect of embolization in patients with AVM.
PMID- 10783552
TI - [Diffusion MRI and cerebral ischemia. When to calculate the coefficient of
diffusion?].
AB - INTRODUCTION: There are two types of diffusion images: so-called "diffusion
weighted" images (DWI) and apparent diffusion coefficient (ADC) images. For
certain authors, ADC mapping is crucial for interpreting diffusion images while
for others the ADC map adds no further sensitivity or specificity compared with
diffusion weighted images. The objective of this work was to determine those
situations where ADC mapping modifies image interpretation. MATERIAL AND METHODS:
T2-weighted and diffusion-weighted (DIF) MRI sequences were acquired in 197
patients with suspected cerebral ischemia (< or = 48 hr). For each lesion (239
lesions in the 197 patients), we analyzed MRI interpretation with and without ADC
mapping and compared the interpretations with the final diagnosis established on
clinical data and complementary explorations. RESULTS: We observed 3 groups. In
group A (36% of the lesions), ADC mapping did not change image interpretation.
This group was subdivided into 3 subgroups. A1: T2 and DIF weighted images are
normal: no lesions and normal ACD map (n = 38 patients); A2: High intensity
signal on T2 and low intensity signal on DIF: ischemic sequelae, ADC always
increased (n = 32 lesions); A3: T2 normal and high intensity signal on DIF: hyper
acute ischemia and ADC always decreased (n = 16 patients) In group B (high
intensity signal on T2 and DIF, 54.5% of the lesions), ADC mapping changed the
MRI interpretation: there was acute ischemia if the ADC was decreased (n = 113)
and "pseudo-ischemic" lesions if the ADC was normal or increased (n = 17
patients). Group C was comprised of 23 lesions with a false negative ADC (9.5%).
These lesions were always small recent ischemic lesions (< or = 5 mm) with a high
intensity signal on DIF and a strictly normal ADC map. CONCLUSION: ADC mapping
was found to be useful in 54.5% of the lesions and should not be considered as
solely a research tool but also as a useful tool for routine clinical practice.
PMID- 10783553
TI - [The value of MRI for the diagnosis of meningeal hemorrhage during vasospasm].
AB - Retrospectively, subarachnoidal hemorrhage can be misdiagnosed when the acute
event did not bring the patient to medical attention, when clinical history is
unclear and the CT scan is normal. Moreover, days after subarachnoid hemorrhage,
cerebral vasospasm can result in neurological deficits that are indistinguishable
from that produced by other causes of stroke. We report our experience with two
patients who presented with symptoms of ischemia due to an arterial vasospasm
that followed unrecognized rupture of an intracranial aneurysm. In both cases, CT
scan failed to detect subarachnoid hemorrhage while MR detected the presence of
signal changes in the subarachnoidal spaces associated with an ischemic stroke in
one case. Neurological symptoms resolved completely after aneurysm treatment. MR
can be a critical for the diagnosis of stroke secondary to vasospasm in order to
prescribe an adapted treatment, avoid anticoagulant or thrombolytic therapy, and
rapidly exclude the recently ruptured aneurysm to protect the patient from the
risk of rebleeding.
PMID- 10783555
TI - Intramedullary cavernous malformations.
AB - Five cases of intramedullary cavernous malformations were retrospectively
reviewed. There were 4 women and one man ranging in age from 30 to 67 years.
Thoracic spinal cord was involved twice and cervical cord in three cases. Four of
them underwent surgery: two improved, one remained stable and symptoms worsened
in one. Clinical, radiological features and surgical management are discussed in
the light of the follow-up and literature analysis. The role of T2* weighted
sequence in MR diagnosis of intramedullary cavernomas is emphasised.
PMID- 10783554
TI - [Capillary telangiectasis, angiographically occult vascular malformations. MRI
symptomatology apropos of 7 cases].
AB - OBJECTIVE: Describe the MRI findings in capillary telangiectasias. MATERIALS AND
METHODS: Between 1996 and 1999, we observed 9 cases of capillary telangiectasia
in 7 patients explored 5 times for posterior fossa symptoms. In two cases
capillary telangiectasia was a fortuitous discovery. All patients were explored
by MRI with T1 sequences with and without gadolinium injections, turbo spin echo
T2 coupled in 5 cases with a double echo gradient echo T2 sequence (TR: 970 ms,
TE: 15 and 35 ms). Two patients also underwent vertebral angiography. RESULTS:
The telangiectasia gave a low intensity signal on T1 sequences in 2 of the 9
cases and a discretely high intensity signal on T2 sequences in all cases. After
gadolinium injection, 9 telangiectasias showed homogeneous or speckled
enhancement. The echo-gradient T2 images showed a very low intensity signal in 7
out of 7 cases on the second echo. At the first echo, 4 capillary telangiectasias
were undetectable. The two vertebral angiographies were normal and the follow-up
MRI in 5 patients showed lesion stability. CONCLUSION: Pontile lesions with no
mass effect showing enhancement after gadolinium injection and with or without a
discrete T2 high intensity signal but with a frank echo-gradient T2 signal
strongly suggest capillary telangiectasia.
PMID- 10783556
TI - [Diffusion imaging in asymptomatic focal vasospasm. Apropos of a case].
AB - We report a case of an asymptomatic vasospasm with a focal, reversible apparent
diffusion coefficient (ADC) decrease after a middle cerebral artery aneurysm
rupture. This isolated decrease of ADC has not yet been reported in this
pathological situation. It could be interesting to predict the risk of ischemic
delayed complications of vasospasm.
PMID- 10783557
TI - [Cerebral panthrombophlebitis in a paucisymptomatic patient].
AB - In most cases, extensive cerebral venous thrombosis present themselves with a
severe clinical outcome and poor prognosis. We present the case of a 59-years-old
patient with a slight rather unrevealing symptoms but suffering from a cerebral
thrombosis impacting on both superficial and deep venous system. The etiologic
assessment revealed activated protein C resistance. Clinical evolution under
systemic anticoagulation was prompt, with complete repermeabilization of the
various venous structures.
PMID- 10783558
TI - Isolated histiocytosis X of the pituitary stalk.
AB - A case of histiocytosis X granuloma localized in the pituitary stalk is reported.
Coronal and sagittal magnetic resonance imaging views were useful to determine
the precise size and location of the mass lesion. The diagnosis was established
immunohistochemically and the patient was treated with low-dose irradiation
therapy. After irradiation, the patient improved well without endocrine
replacement treatment. The pituitary stalk recovered its normal size with no
evidence of recurrence on MRI at 7-year follow-up. We emphasize the importance of
MRI before initiating therapy to evaluate the pituitary mass lesion and the
effectiveness of low-dose irradiation for isolated histiocytosis X.
PMID- 10783559
TI - Periodontal relevance of anterior crowding.
AB - The periodontal relevance of anterior and posterior crowding concerns 3 main
aspects: 1. oral hygiene/plaque retention, 2. altered topography of gingiva,
septum and orofacial alveolar bone and 3. periodontal therapy (scaling, root
planing, regenerative approaches). These aspects are discussed with regard to the
literature and to the author's own clinical and histological findings. Present
day knowledge suggests that the following positive periodontal effects can be
expected from correction of orthodontic crowding: better access for oral hygiene,
improved morphology of soft and hard periodontal tissues; future research has to
substantiate the value of this benefit, simplified mechanical and surgical
therapy (scaling, root planing, curettage), more favorable conditions for
periodontal regeneration.
PMID- 10783560
TI - Efficacy of protection by latex gloves during orthodontic therapy.
AB - The wearing of gloves during orthodontic or dental treatment is generally
indicated for reasons of hygiene and protection against infection. This study was
aimed at determining the extent and localization of perforations caused by the
various orthodontic treatment techniques and interrupting the infection barrier.
The impermeability was tested by means of a water retention test according to
European standard EN 455, Part 1, performed on 1600 Centramed (Centramed,
Koblenz), Tekmedic and SafeEx non-sterile disposable latex gloves (both by Safe
Med, Switzerland) and Safe Gan latex gloves with an additional acrylate coating
(also by Safe Med). The perforation rate in unused gloves was between 0.5% and
7.5%, rising on average to 11% with increasing use. 36% of the total number of
lesions resulted from handling removable appliances, and 57% from handling fixed
appliances, especially when replacing arch wires and elastics. Most lesions were
in the thumb, index finger and palm region. Only 18% of the defects were noticed
by the dentists themselves. The gloves worn by beginners in their first year of
postgraduate orthodontic training had about twice as many defects as those worn
by qualified orthodontists. When patients with an increased risk of infection are
to be treated, additional hand disinfection measures should be taken and 2 pairs
of gloves worn in view of the relatively unreliable protection offered by
commercially available latex gloves.
PMID- 10783561
TI - Prospective study on the reproducibility of cephalometric landmarks on
conventional and digital lateral headfilms.
AB - The introduction of digital X-ray techniques offered a variety of new
possibilities for digital image enhancement and exposure reduction. In order to
compare the reproducibility of cephalometric landmarks on conventional and
digital lateral headfilms 100 digital and 100 conventional lateral headfilms of
patients attending our clinic were randomly selected. The digital cephalograms
were obtained using storage phosphor plates in standard X-ray cassettes. All X
rays had been taken at 77 kV. For the digital images the mAs settings for
conventional images minus 4 mAs were used. Two orthodontists traced each X-ray
twice (21 reference points) at an interval of at least 1 week. The tracings were
superimposed and the distances between the tracings of identical reference points
were registered. The average reproducibility of cephalometric landmarks was
significantly higher on the digitally obtained images, despite a reduction of
radiation exposure of 23.7% in the digital images.
PMID- 10783562
TI - Transcutaneous electrical nerve stimulation (TENS): its short-term and long-term
effects on the masticatory muscles.
AB - In an electromyographic study on subjects with no functional disturbances of the
masticatory muscles, the duration of the post-therapeutic effects of
transcutaneous electrical nerve stimulation (= TENS) on the superficial masseter
and anterior temporal muscle was analyzed. The myoelectric signals were
registered from 20 healthy volunteers in 3 different mandibular positions. The
recordings were performed before a 20-minute TENS application with the J-4
Myomonitor and continued with a sequence of follow-up registrations with
increasing interval to the initial stimulation. The EMG signals underwent
computer-aided analysis and were evaluated by determining the integrated values
as a parameter of muscle activity, and after Fourier transformation by 7
describing parameters of the power spectrum (e.g. mean power frequency = MPF). A
detailed analysis of variance of all data was used to investigate significant
changes of the parameters during the observation period. Muscular response to
TENS includes a decrease in muscular activity (= reduction in integrated EMG
signals) and a shift in the power spectrum to higher frequencies (increase in
MPF). These changes were statistically highly significant for both analyzed
muscles and for all different mandibular exercises. As these reactions to TENS
are contrary to muscle fatigue, the results can be interpreted as indicating that
this type of therapy stimulates a change in the biochemical and physiological
muscular conditions, which leads to muscle relaxation. Electromyographically, the
post-therapeutic effect lasted for 2 hours in case of normal masticatory muscle
activity but for more than 7 hours in case of low muscular loading. The
alterations of the integrated EMG values were more persistent than those of the
parameters of the power spectrum.
PMID- 10783563
TI - Follow-up control of patients with unilateral posterior cross-bite treated with
expansion plates or the quad-helix appliance.
AB - The aim of this study was to evaluate the long-term stability of the occlusion
after correction of posterior cross-bite with either a removable expansion plate
or a quad-helix appliance and to compare the transversal development of the jaws
in the plate group, the quad-helix group and a control group. At the start of
treatment there were 22 children in each of the treated groups. Two children in
the plate group and 1 child in the quad-helix group discontinued the treatment.
Two children treated with the quad-helix appliance and 1 child in the plate group
could not be reached for the follow-up registration, so the collective finally
consisted of 30 boys and 27 girls: 19 subjects in the plate group, 19 in the quad
helix group and 19 controls. The treatment groups were studied with the help of
plaster models before treatment, immediately after treatment and at the last
registration about 5.5 years after treatment. The control group was studied with
the help of plaster models on 2 occasions, at the mean age of 8.8 years and 15.9
years respectively. This was about the same age as the first and the last
registrations in the treatment groups. In all children, the posterior cross-bite
was corrected by the end of the treatment. At the last registration, the
corrected posterior cross-bite had relapsed in 1 child in the plate group and in
3 children in the quad-helix group. The degree of expansion was similar for both
groups. The mean treatment time was longer in the plate group than in the quad
helix group: 12.5 months and 7.7 months respectively. Despite a transversal
expansion in the treatment groups, the width of the maxillary dental arch did not
reach the mean width in the control group, and even at the last registration the
width of the maxillary dental arch was significantly greater in the control group
than in the treated groups. The conclusions of this study are: 1. The long-term
treatment effect in children with posterior cross-bite was somewhat better when
they were treated with the removable expansion plate in comparison with treatment
with the quad-helix appliance. 2. Both immediately after treatment and at the
last registration 5.5 years later, the width of the maxillary dental arch was
significantly greater in the control group than in the plate group or the quad
helix group while the width of the mandibular dental arch was equal in all 3
groups.
PMID- 10783564
TI - Pain in orthodontics. A review and discussion of the literature.
AB - This literature review focuses on previous studies of pain and pain perception in
dentistry with special emphasis on orthodontic treatment. The prevalence of pain
and background factors such as age, gender and culture/society, in addition to
pain physiology and the influence of concomitant emotional and cognitive factors,
is examined. Pain during orthodontic tooth movement is reported from the point of
view of its physiology and character and different assessment methods. These
aspects are described both generally and specifically in relation to the type of
orthodontic forces and to the experience of discomfort other than pain. Since the
orthodontic treatment may cause some degree of suffering for the patients, it is
important for orthodontists to handle this situation in the best possible way.
Some ideas about the possibilities of avoiding, reducing or alleviating pain in
orthodontics are discussed.
PMID- 10783565
TI - The influence of a 0.2% chlorhexidine mouthrinse on plaque regrowth in
orthodontic patients. A randomized prospective study. Part II: Bacteriological
parameters.
AB - In a prospective plaque regrowth study focusing on oral hygiene during fixed
appliance therapy 12 adolescent patients (mean age 14.1 +/- 1.5 years) were
evaluated twice over 2-day test periods. In the randomized, double-blind study
the influences of a 0.2% chlorhexidine mouthrinse (Corsodyl, CHX) and a
commercially available dentifrice supplementing fluoride (Odol-med-3) were
compared intra- and interindividually in a crossover design with regard to the
bacteriological parameters. The bacteriological parameters of vital fluorescence,
bacteriological counts (BC), colony forming units (CFU), plating efficiency (PE)
and mutans streptococci (MS) were related to the clinically assessed indices of
plaque and gingivitis. All parameters analyzed demonstrated significant
differences between the control and the test (chlorhexidine) group. Where-as the
values of BC, CFU, and PE progressively increased in the control group from T0 to
T2, these parameters distinctly decreased in the chlorhexidine group. All values
of vital flora (VF) scored around 75% in the control group compared to values of
30% in the test group. BC, CFU und PE correlated significantly. The score of
mutans streptococci persisted or increased in the controls whereas mutans
streptococci approached 0 in the chlorhexidine group. Until the 5th day of
washout a clear-cut carry over of the chlorhexidine rinse on mutans streptococci
as well as on the gingival index was evident. Since dead microorganisms remain on
the tooth surface and in order to maintain oral health, chlorhexidine application
might advisedly be supplemented by mechanical plaque control.
PMID- 10783566
TI - [Single-blood-sample method for the determination of glomerular filtration rate
using 99mTc-DTPA in Japanese].
AB - The study was aimed to evaluate glomerular filtration rate with 99mTc-DTPA by
means of a single-plasma-sample method in Japanese. Three were 50 patients (29
males and 21 females, age range being 25 to 91 years) with diabetes mellitus of
various degree of the renal function. 99mTc-DTPA of 300 MBq/2 ml that was
prepared in our hospital was injected. Dynamic renal scintigraphy was carried out
and 10 blood samples were taken after the injection. Blood clearance (true GFR)
of 99mTc-DTPA was determined from plasma concentration which was fitted to the
biexponential curve by a non-linear least squares method. Plasma concentration
(ml/min/1.73 m2) after 75 min-post injection showed very higher linear regression
and linear correlation with true GFR than 0.900. The best linear regression and
linear correlation was observed with 180 min-sample (r = 0.989). As general, the
following equation was obtained; Y = A + Bln(X), A = 436.1217 - 3.45817t +
0.01205t2 - 0.000015t3, B = -212.601 + 1.42518t - 0.04834t2 + 0.0000062t3, X =
plasma concentration at sampling time t (%ID/L/1.73 m2), t = sampling time from
75 to 300 min (r > 0.900). This is the new equation of single-plasma-sample
method for the determination of GFR using 99mTc-DTPA for Japanese. The clinical
feasibility should be accessed in a field of a nuclear medicine practice.
PMID- 10783567
TI - [Evaluation of technetium-99m-MIBI scintigraphy in metastatic differentiated
thyroid cancer--comparison study with 131I and 201Tl].
AB - Detectability of metastasis in differentiated thyroid cancer using technetium-99m
methoxyisobutyl isonitrile (99mTc-MIBI) was compared with that of 131I and 201Tl.
Forty patients after total thyroidectomy were evaluated. The scan results were
compared with those of 131I and 201Tl whole body scintigraphy per patient. The
positive rate was 68% in 99mTc-MIBI, 84% in 131I, 60% in 201Tl respectively. As
to the lymph node metastasis, the positive rates were 56% in 99mTc-MIBI, 78% in
131I, 39% in 201Tl. In lung metastasis, the positive rate was 46% in 99mTc-MIBI,
82% in 131I and 55% in 201Tl. Serum thyroglobulin (Tg) was significantly higher
in 201Tl and/or 99mTc-MIBI positive group compared to that of negative group
independent of 131I scan results. Although the detectability of both 99mTc-MIBI
and 201Tl were inferior to that of 131I, 9 to 22% of metastasis were detected
only by these radiopharmaceuticals. Both 99mTc-MIBI and 201Tl, therefore, should
be used in cases with high serum Tg even with negative 131I uptake. Basing on the
fact there was no prominent difference between 99mTc-MIBI and 201Tl in the
detectability of metastasis, 99mTc-MIBI might be more suitable tracer because of
better quality image.
PMID- 10783568
TI - [Is the cardiac function improvement after PTCA predictable by the quantitative
indices from exercise stress 201Tl myocardial SPECT, in patients with old
myocardial infarction?].
AB - PURPOSE: We examined whether the improvement of left ventricular function after
percutaneous transluminal coronary angioplasty (PTCA) in patients with one
diseased vessel can be predicted by the quantitative indices from exercise stress
201Tl single photon emission computed tomography (SPECT) and radionuclide
angiography (RNA) before PTCA. METHODS: Exercise stress 201Tl myocardial SPECT
and RNA were performed before and after PTCA in 28 patients with old myocardial
infarction (OMI). The patients were divided into two groups according to the
results of coronary angiogram performed at 3 to 6 months after PTCA; patency was
confirmed in 22 patients (Group P) and restenosis was observed in the remaining 6
patients (Group S). RESULTS: In Group P, the count ratios defined as 201Tl uptake
in the PTCA region divided by the uptake in the normal region were significantly
improved at 1 week and 3 to 6 months after PTCA in the initial image. 201Tl
washout rates in the normal regions were significantly increased at 1 week after
PTCA in Group S, and these rates in the PTCA regions were significantly increased
at 1 week after PTCA in Group P. Left ventricular ejection fractions (LVEF)
obtained from RNA were significantly improved 1 week and 3 to 6 months after PTCA
in Group P. The changes of LVEF between pre-PTCA and 3 to 6 months after PTCA
(delta LVEF) were significantly correlated with the count ratios of both initial
and delayed SPECT images in Group P (r = 0.652; p < 0.01, r = 0.645; p < 0.01
respectively). From the multiple regression analysis using stepwise methods, the
count ratio in delayed image and the LVEF before PTCA were selected as
independent predictive variables for delta LVEF (multiple correlation coefficient
= 0.776). CONCLUSION: Thus, the improvement of LVEF after PTCA may be predictable
by the count ratio in the delayed SPECT image and LVEF before PTCA when the
treated vessel is persistently patent.
PMID- 10783569
TI - [The outcome of treatment with adjusted dose of 131I to thyroid weight for
Graves' disease by estimation of effective half life using a single radioiodine
uptake measurement].
AB - In the determination of therapeutic 131I doses, it takes several days to measure
effective half life (EHL) of radioiodine in thyroid glands (Ordinary method). We
suggested the new method to estimate EHL by a single radioiodine uptake
measurement (INDEX method). We evaluated the outcome of 131I treatment with these
two methods in outpatients with Graves' disease. Eighty outpatients were treated
with INDEX method (Group I) and 108 outpatients with Ordinary method (Group O).
At the 5-yr follow up, the incidence of hypothyroidism in Group I was 22.5%,
subclinical hypothyroidism 8.8%, euthyroidism 30.0%, subclinical hyperthyroidism
13.7% and hyperthyroidism 25.0%. In Group O, 17.6% of the patients were
hypothyroid, 16.7% subclinical hypothyroid, 30.5% euthyroid, 9.3% subclinical
hyperthyroid and 25.9% hyperthyroid. There were no significant differences
between these two methods. We conclude that INDEX method surpasses Ordinary
method in timesaver and is equal in effectiveness.
PMID- 10783570
TI - [Impairment of septal uptake and washout on 123I-BMIPP myocardial SPECT after
pacemaker implantation: report of two cases].
AB - Case 1 involved a 62-year-old woman with complete atrioventricular block and case
2 involved a 70-year-old woman with sick sinus syndrome. In both cases,
echocardiography, 123I-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP)
and 99mTc-tetrofosmin myocardial single photon emission computed tomographic
(SPECT) findings were normal. Coronary arteriography and left ventriculography
also revealed normal in both cases. After pacemaker implantation (DDD-type in
case 1 and VVI-type in case 2), both patient's electrocardiograms revealed left
bundle branch block-type conduction disturbance, and echocardiography showed
asynchronous hypokinesia in the septal region. One year later, although both
patient's ATP loading tetrofosmin SPECT were normal, BMIPP SPECT showed reduced
uptake and increased washout in the septal region. These findings suggest that
these changes of BMIPP SPECT might be caused by left bundle branch block-type
conduction disturbance after pacemaker implantation.
PMID- 10783571
TI - [111InCl3 uptake in ununited fractures: a case report].
AB - 111InCl3 scintigraphy was performed in a 37-year-old male with pancytopenia.
Intense tracer uptake in the ununited rib fractures was recognized. There are few
descriptions of 111InCl3 uptake in ununited fracture, and this case indicated
that ununited fracture should be added to the differential diagnosis of 111InCl3
uptake.
PMID- 10783572
TI - [Dopamine transporter SPECT in patients with Parkinson's disease].
AB - The major neuropathological feature in Parkinson's disease (PD) is severe
degeneration of the dopamine (DA) neurons in the substantia nigra. Dopamine
transporter (DAT) is an important protein in the regulation of DA
neurotransmission. It has been reported that PD patients show a loss of DAT in
striatum. We report here the findings of single photon emission computed
tomography (SPECT) of the DAT with 2 beta-carboxymethoxy-3 beta
(4[123I]iodophenyl)tropane ([123I] beta-CIT) to investigate striatal DAT in 10
patients with PD, one patient with vascular parkinsonism (VP), and one patient
with dystonia syndrome. Patients were evaluated using the Webster rating scale.
Specific/nondisplaceable striatal binding ratio (V3") was obtained in each case.
In PD patients, the uptake of [123I] beta-CIT was reduced, especially in the tail
of putamen compared with caudate nucleus. Even in the early stage of PD, the
uptake of beta-CIT was reduced not only in the severely affected side, but also
in the mildly disturbed side of the brain. Putamen caudate ratio was generally
low in PD patients. In VP patient, the uptake was reduced, but putamen caudate
ratio was not decreased. V3" values showed significant correlation with the
severity of clinical symptoms such as self-care, facies, posture, gait, speech,
and Hoehn-Yahr's stage. On the other hand, V3" values were not significantly
correlated with the degree of tremor, seborrhea, and duration of the illness. In
conclusion, we found that SPECT of the [123I] beta-CIT is a useful method for the
diagnosis in the patients presenting parkinsonism, and for the clinico
physiological estimation of parkinsonian symptoms such as self-care, facies,
posture, gait, and speech.
PMID- 10783573
TI - [Comparison of scatter and attenuation correction methods in single photon
emission CT--simulation study].
AB - Quantitative SPECT requires an accurate and appropriate attenuation correction
and scatter correction. This paper compares scatter corrected images combined
with attenuation correction. The scatter correction methods used here were the
deconvolution method, dual energy window subtraction method, triple energy window
method, and dual photopeak window method. The attenuation correction methods used
were Sorenson's method, iterative Chang's method, and Bellini's method. The
numerical phantoms used were the cold spot, hot spot, star, and MCAT phantom.
These correction methods were assessed by using profiles and images, contrast
values, and linearity of SPECT values.
PMID- 10783574
TI - [Quantitative evaluation for scatter and attenuation correction in 99mTc SPECT-
multicenter cooperation phantom study].
AB - A multicenter cooperation phantom study was conducted to evaluate the accuracy of
a triple energy window scatter correction technique in combination with various
attenuation correction methods for 99mTc single photon emission computed
tomography (SPECT) imaging. Six centers participated in this research and the
data obtained with seven SPECT instruments were analyzed. The phantom used in the
experiment was a 20 x 10 cm cylinder filled with homogeneous 99mTc solution,
containing two kinds of cold spots (cold rod phantoms). One had a water-filled
cylinder 5.5 cm in diameter positioned 2.5 cm from the center. The other
contained 6 water-filled cylinders of various sizes. Contrasts of cold regions
were in the range from 74% to 120% (true 100%). Another phantom had the shape of
a pie-chart divided into six chambers symmetrically positioned in a cylinder 20
cm in diameter and 10 cm in height. Each chamber had volume of 480 ml and
contained homogeneous 99mTc solution of different concentrations. This phantom
was used to test for linearity between the radio activity concentration and
reconstructed count density (linearity phantom). The intercept of the regression
line obtained from the linearity phantom was 8.4 kBq ml-1 without scatter
correction and -6.8 kBq ml-1 with scatter correction. Contrast was in the range
from 78% to 132% (true 100%). The mean relative error for the measured activity
concentration was 4.9% +/- 3.5% (mean +/- sd).
PMID- 10783575
TI - [Clinical features of 25 patients with cytomegalovirus infection complicating
hematological diseases unrelated to allogeneic bone marrow transplantation].
AB - The clinical features of 25 cases of cytomegalovirus (CMV) infection complicating
hematological diseases were analyzed. These cases did not undergo allogeneic bone
marrow transplantation. 21 cases (84%) had a lymphoid tumor including 16 cases
(64%) of malignant lymphoma and three cases of adult T-cell leukemia. All
patients but one have received corticosteroid or antineoplastic agents before the
occurrence of CMV infection. The types of CMV infections were interstitial
pneumonia (23 cases), retinitis (2 cases), enteritis (one case), and persistent
pyrexia (one case). Nine cases were diagnosed by histopathology and 5 of these 9
cases were discovered as having a CMV infection at autopsy. 20 cases were treated
with ganciclovir for CMV infection, but only 9 cases improved. Of the 9 cases
diagnosed by CMV-antigenemia, which had been introduced in the late 1994, 4 cases
whose lymphoid tumor had been controlled responded to ganciclovir and survived
but others with uncontrollable disease died. The present study indicates that the
progress in the treatment of CMV infection was achieved in patients with
controllable hematological disease but not in patients with refractory disease
even after introduction of CMV-antigenemia.
PMID- 10783576
TI - [Evaluation of a new method for antifungal drugs susceptibility testing to
yeasts].
AB - We compared the Etest with a broth microdilution method (FP panel), performed
according to the National Committee for modified Clinical Laboratory Standards
(NCCLS) document M27-P guidelines, for determining the MICs of 81 clinical
isolates of yeasts (7 Candida albicans, 8 Candida glabrata, 10 Candida
parapsilosis, 6 Pichia anomala, 10 Candida tropicalis, 4 Candida guilliermondii,
4 Candida krusei, 6 Trichosporon cutaneum, 5 Candida ciferrii, 3 Candida famata,
4 Candida norvegensis, 2 Rhodotorula rubra, 3 Candida lusitaniae, 2 Candida
curvata, 1 Candida inconspicua, 1 Candida intermedia, 1 Candida colliculosa, 1
Cryptococcus spp, 1 Tricosporon capitatum, 1 Pichia ohmeri, 1 Saccharomyces
cerevisiae). The Etest results for 6 ATCC standard strains correlated well with
reference MICs except those of flucytosine (5-FC) for C. krusei, which tended to
be 1 to 2 log2 dilution higher than the MIC range determined by NCCLS guidelines.
However, the best agreement between the results for clinical isolates was seen
with 5-FC (100% agreement [Within +/- 2 log2 dilutions] between the results of
the two methods). There was a 91.4% agreement between the results of the two
methods with amphotericin B (Etest MICs tended to be 1 to 2 log2 dilution lower
than those of the FP panel). The Etest results with litraconazole for clinical
isolates except C. tropicalis were similar to MICs of the FP panel (Etest for C.
tropicalis showed 1 to 2 log2 dilution lower than FP panel). Also, the Etest
results with fluconazole for clinical isolates except C. tropicalis were similar
of 1 log2 dilution higher than MICs of the FP panel (Etest for C. tropicalis
showed more than 2 log2 dilution lower than FP panel). These results showed a
good level of overall agreement between the Etest method and the broth
microdilution test (FP panel). Since the Etest is a less laborintensive and much
simpler method, it appears to be a useful procedure for testing the
susceptibility of yeasts to antifungal agents.
PMID- 10783577
TI - [Clinical study of an outbreak of aseptic meningitis due to echovirus type 30 in
Munakata City in 1997-1998].
AB - From October, 1997 through July, 1998, an outbreak of aseptic meningitis due to
echovirus type 30 occurred in the northern part of Kyushu area in Japan. In this
outbreak, clinical and virologic observations were carried out on 157 in-patients
with aseptic meningitis at our hospital. The age of the patients ranged from 1
year and 9 months to 57-year old. One hundred and twenty out of 157 cases were
the children under 15 years of age, and in this age group, male/female ratio was
2:1. The largest proportion of cases occurred in the 5- to 9-year age group. The
number of cases reached a peak in December, 1997, but the epidemic extended to
the next summer. In 12 families, more than one person became ill (total 22
cases). Virus isolation from cerebrospinal fluid (CSF) was tried on 130 out of
157 cases. Echovirus 30 was isolated in 74 cases (58 children, 16 adults), and
echovirus 18 in 9 cases from June, 1998 until the end of the study. Paired acute
and convalescent sera were available from the 25 patients with negative virus
isolation, and 7 out of 25 patients had a fourfold or greater rise in
neutralizing antibodies. Headache, fever, vomiting, nuchal rigidity were
detectable in most cases, but in this outbreak, continued severe headache was
characteristic. Eye pain was experienced by 2% of the total cases. In children,
gastrointestinal symptoms were noted in 12% of the cases, but were not in adult
patients. The CSF cell counts ranged from 2 to 3,478 cells per cubic millimeter.
Fifty-eight percent were predominantly lymphocytic, while 42% were
polymorphonuclear predominant. Virus was highly isolated from the CSF when the
specimens were obtained within three days after the onset of the acute illness,
but in one case, virus was isolated on day 7. In a few cases, virus was isolated
without pleocytosis in CSF.
PMID- 10783578
TI - [A study of anti-HIV compounds which interfere the virus entry via coreceptor
CXCR4].
AB - T22 is an anti-HIV polypeptide which was synthesized with chemical modification
from the horse shoe hemocytic polypeptides, polyphemusin II as a lead compound.
T22 was found to block T-tropic HIV-1 entry into target cells as a CXCR4
antagonist. We synthesized T134, a small sized analog of T22 with reduced
positive charges. T134 exhibited highly potent activity and significantly less
cytotoxicity when compared to T22. It was shown that bicyclam AMD3100 and ALX40
4C are antagonists of CXCR4, and vMIP II which is coded chemokine in HHV8/KSHV
effects antagonistically both CXCR4 and CCR5. We examined the anti-HIV activity
of these CXCR4 antagonists. All of them inhibit the binding of anti-CXCR4
antibody (12G5) to PBMC, but have no effect on the binding of anti-CCR5 antibody
(2D7) except for vMIP II. vMIP II decreased the binding of both 12G5 and 2D7. In
these compounds, T134 showed the most potency to anti-HIV activity. We also
attempted to clarify the cross resistance between these antagonists, using HIV-1
resistant to AMD3100. T134, ALX40-4C and vMIP II are active against the AMD3100
resistant strain. This observation indicates the potential of using these the
inhibitors as a new type of agent preventing HIV entry.
PMID- 10783579
TI - [Why there were few isolations of tubercle bacilli in young children with
pulmonary tuberculosis?].
AB - We retrospectively evaluated the factors influencing the isolation of tubercle
bacilli in 51 children under 14 years of age with pulmonary tuberculosis who were
admitted to Yokohama City University Hospital from 1975 to 1998. Young children
(0-6 years of age) with pulmonary tuberculosis were significantly less positive
by smear and culture than elder children (7-14 years of age) with pulmonary
tuberculosis. According to the Japanese Society for Tuberculosis classification
of finding on chest X-ray film for pulmonary tuberculosis, the culture-positive
patients with type II (cavitary lesions) were found in all, the culture-positive
patients with type III (non-cavitary lesions) in 39.3%, and the culture-positive
patients with type H (hilar and mediastinal lymphadenopathys) in 35.3%. Patients
with cavitary lesions (type II) were significantly more positive by smear and
culture than patients with non-cavitary lesions (type III + type H). Only 15.8%
of the young children with pulmonary tuberculosis had received BCG vaccine and
all had non-cavitary lesions (type III and type H). But, 84.6% out of the older
children had received BCG vaccine and half had cavitary lesions. Taken together,
the result was that there were few isolation of tubercle bacilli in young
children with pulmonary tuberculosis because they had non-cavitary tuberculosis
without delayed-type hypersensitivity to tubercle bacilli.
PMID- 10783580
TI - [Detection of extended spectrum beta-lactamases producing Enterobacteriaceae in
feces].
AB - A study was made of 366 feces for detection of extended spectrum beta-lactamases
producing Enterobacteriaceae from feces. The selective agar was used for modified
drigalski agar (Eiken Chemical Co., LTD) with 2 micrograms/ml cefotaxime (ESBL
screen agar). 92 strains of Enterobacteriaceae, 41 Escherichia coli, 15
Citrobacter freundii, 13 Enterobacter cloacae, 11 Klebsiella pneumoniae, and
other 12, were isolated from ESBL screen agar. And, R-plasmid that were selected
by 2 micrograms/ml cefotaxime were transferred by conjugation from two of the 92
strains. These strain were E. coli TH9809927 and Proteus mirabilis TH9808262 that
were amplified by "Toho-1 type" primer. The clude enzyme from two strains (donor)
and transconjugants were especially hydrolysed cepharoridine and cefotaxime.
Accordingly, two strains (0.5%) were detected as ESBL producers. We think that
the result of our survey suggests the increase of ESBLs producing bacterial
infection in Japan, and believe that there is a trend of infection of its by
surveilance of the feces.
PMID- 10783581
TI - [Two cases of hypoxemic acute bronchiolitis due to Mycoplasma pneumoniae].
AB - Two males with acute bronchiolitis due to Mycoplasma (M.) pneumoniae, aged 24 and
39 years were reported. They presented prolonged cough and fever in the early
stage of the disease. Chest X-rays of those patients showed diffused nodular
shadows. Chest CT scan showed diffused nodular shadows and thickning of
bronchovascular marking. Blood-gas analysis indicated hypoxemia without abnormal
A-aDO2. We diagnosed two patients as M. pneumoniae infection by antibody assays.
The Eosinophil cationic protein (ECP) level and IgE level were high. Eosinophilia
and endotoxemia were also observed in two patients. We speculated that the
allergic reaction and endotoxemia may be related to hypoxemia and the clinical
severity of M. pneumoniae infection.
PMID- 10783582
TI - [A case with infectious mononucleosis-like syndrome caused by human herpes virus
6 infection].
AB - A 26-year-old female was admitted because of multiple fractures in lower
extremities. While in the hospital, she developed a high fever and generalized
skin eruption. Physical examination revealed bilateral cervical lymphadenopathy
and mild hepatosplenomegaly. The white cell count was 11,200 with 11% atypical
lymphocytes. Serum GOT, GPT, LDH were markedly elevated. Infectious mononucleosis
was suspected, but the serological test for EB virus did not show evidence of
acute EB virus infection. Anti-HSV, CMV, hepatitis A virus antibody titers also
did not show significant change during the coarse. The serological test for HHV-6
only showed increased titer of IgM and IgG antibodies. Rapidly elevated IgG
antibody titer was indicative of reactivation of HHV-6. So, she was diagnosed as
mononucleosis-like syndrome caused by HHV-6, probably reactivated infection. Her
symptoms gradually disappeared during a month.
PMID- 10783583
TI - [A case report of Campylobacter fetus subspecies fetus oophoritis].
AB - A 45-year-old female with oophoritis (pelvic inflammatory disease) caused by
Campylobacter fetus (C. fetus) is reported. She was admitted to the hospital
because of high fever and an acute abdomen. On admission, severe inflammation was
observed by the laboratory findings, and abdominal X-ray and CT scan revealed
ileus with marked swelling of the right ovary. Laparotomy was performed with
adonexooophrectomy due to the tubo-ovarian abscesses. C. fetus was isolated from
the right ovary, salpinx and ascites. Erythromycin was administered after a
sensitive test of C. fetus as the bacteria was isolated at operation. She was
discharged on the 17th day after her admission. Indirect immunofluorescent test
with hyperimmune rabbit sera to isolated C. fetus revealed a fine to coarse
granular immunoreaction in the cytoplasm of the macrophages infiltrated in the
tissue. This result was interpreted as the existence and growth of bacteria in
the right ovarian tissue. Oophoritis due to C. fetus subspecies fetus is very
rare. To our knowledge, this case is the second case reported in Japan.
PMID- 10783584
TI - [A case of pulmonary Nocardia farcinica infection in a patient with non
tuberculous mycobacteriosis].
AB - A 64 years old woman without systemic immunological disorders was admitted to our
hospital because of a productive cough, low grade fever and bloody sputum. Chest
X-ray revealed multiple nodules with calcification, infiltrates and
bronchiectasis. Laboratory findings showed mild hypoproteinemia and elevated
sedimentation rate. Both Nocardia farcinica and Mycobacterium intracellulare were
isolated from the bronchial lavage fluid. Administration of sulfamethoxazole
trimethoprim improved her symptoms. In a recurrent study of bronchial lavage N.
farcinica was not isolated, but M. intracellurale was still isolated. We believe
that N. farcinica may cause infectious exacerbation of chronic lung disease: non
tuberculous mycobacteriosis and bronchiectasis.
PMID- 10783585
TI - Outbreak of Japanese spotted fever in the southeastern part of Awaji Island.
PMID- 10783586
TI - The natural and the supernatural in melancholic genius. A debate in sixteenth
century Spanish medicine and its antecedents.
PMID- 10783588
TI - Professional ethics and discipline: the Prussian medical courts of honour, 1899
1920.
PMID- 10783587
TI - [Learning before enlightenment? On the popular medicine manuscripts of the
physician and best selling author Christoph von Hellwig (1663-1721)].
PMID- 10783590
TI - [Nucleotides and lactation milk].
PMID- 10783589
TI - Assessing neuropathological research carried out on victims of the 'euthanasia'
programme. With two lists of publications from Institutes in Berlin, Munich and
Hamburg.
PMID- 10783591
TI - [Cisapride and risk of cardiac complications].
AB - Cisapride is a prokinetic agent thought to be without severe side effects.
Recently, rare cisapride-induced cardiotoxic effects (QT interval prolongation,
ventricular arrhythmias) have been reported, raising questions about its safety.
Some risk factors have been reported: overdosage of cisapride, association with
some drugs inhibiting hepatic metabolism via the cytochrome P450 3A4 enzymatic
system (such as azole antifungals, macrolide antibiotics, non sedating
antihistamines), other pharmacological agents increasing the parasympathetic tone
by raising the effect of cisapride (such as ranitidine and cimetidine),
electrolyte abnormalities (such as low serum levels of calcium, potassium and
magnesium in the blood), liver dysfunctions, congenital long QT syndrome, and
infants born before 36 weeks' gestation, for three months after birth.
Physicians, prescribing cisapride should pay attention to these risk factors, to
avoid the possibility of a rare cardiac adverse effect.
PMID- 10783592
TI - Langer-Giedion syndrome. A patient without mental retardation and a large 8q23.2
q24.22 deletion.
AB - Mental retardation (MR) is a typical feature of Langer-Giedion syndrome (LGS).
Only 18 cases of LGS without MR have been reported. All of them either had normal
karyotype or carried a deletion not exceeding the 8q24 band. Thus, it has been
proposed that MR in LGS patients is associated with larger deletions. A patient
with LGS and a large 8q23.2-q24.22 deletion but without MR is reported. This case
suggests that there is not any particular gene which alone is responsible for MR
in LGS patients, but it is the reduced expression of a large number of genes
which predisposes to MR.
PMID- 10783593
TI - Bone marrow hypoplasia associated with acute viral hepatitis in four children.
AB - Four cases of children, aged 2 to 11 years, with acute viral hepatitis and bone
marrow hypoplasia are reported. Three patients presented only jaundice and
hepatomegaly; one also had liver failure. All the four patients underwent bone
marrow aspiration which showed bone marrow aplasia. In two of the four patients a
liver biopsy revealed patchy necrosis with inflammatory mononuclear cell
infiltrate. Half of the patients received a bone marrow transplantation; the
remaining patients were treated by intravenous infusion of immunoglobulins,
growth factors and steroids. The main epidemiological and etiological features of
such association are also reported.
PMID- 10783595
TI - Issues resonate with physician.
PMID- 10783594
TI - [Feeding].
PMID- 10783596
TI - The decline and fall of HMOs.
PMID- 10783597
TI - Long-term outcome following pancreas surgery.
PMID- 10783598
TI - Showtime
PMID- 10783599
TI - Medical consumers browse a chaotic cyberspace.
PMID- 10783600
TI - Mini med school. For that little bit of doctor in everyone.
PMID- 10783601
TI - Lessons from the heart.
PMID- 10783602
TI - Health policy hub.
PMID- 10783603
TI - Leading the way.
PMID- 10783604
TI - Regional differences in cardiovascular mortality in Minnesota.
AB - Cardiovascular disease is the leading cause of death in the United States.
Initial results from our health survey in the Red River Valley of Minnesota
suggested elevated cardiovascular mortality in men and women in younger age
groups there compared with the rest of the state. Similarly, earlier published
longitudinal studies of cardiovascular mortality in Minnesota revealed increased
cardiovascular mortality in counties west of a diagonal line drawn through the
tip of the arrowhead region (northeast Minnesota) to the southwest corner of the
state. In this study we examined cardiovascular mortality by geographic region
with respect to economic factors, residence patterns, and ethnic group. Since
these regions vary in geology and major land use, environmental factors were
considered as well. Our present data show a significant elevation in
cardiovascular mortality from 1987-1997 in men and women aged 25-59 in northwest
and northeast Minnesota counties compared with central-metro counties. In
contrast, south-central Minnesota shows a rate of cardiovascular mortality for
that age group similar to that seen in the central-metro region. The increase in
cardiovascular deaths from myocardial infarct in the younger groups in the more
rural, less affluent areas of northwest Minnesota is nearly two times higher than
in the central-metro counties. Genetic factors may play a role in the increased
mortality recorded for northeast Minnesota. Environmental contaminants such as
pesticides are additional considerations. Finally, our data suggest the need to
address long-standing regional cardiovascular mortality differences and rural
health care access in Minnesota.
PMID- 10783605
TI - Loneliness: an overlooked and costly health risk factor.
PMID- 10783606
TI - [Treatment of benign prostatic hyperplasia syndrome. 2: Interventional therapy].
AB - The invasive treatment modalities available fur BPH can be divided into
interstitial therapy without removal of tissue (e.g. stents), and those involving
delayed tissue ablation (thermal/coagulation procedures, e.g. laser ablation,
microwave thermo-ablation, high-intensity ultrasound). The latter procedures
(coagulation) more often permit a nonbloody intervention, the sphincter usually
remains uninjured, and retrograde ejaculation is less frequent. A third group of
options is interventional treatment, with immediate ablation of tissue
(vaporization, resection), which is more invasive and associated with a higher
risk of complications than the two first-mentioned groups. An advantage of these
options is the avoidance of a longer-term catheterization with its associated
risks. Help is provided for deciding which procedure should be used in which
patient.
PMID- 10783607
TI - [Carbohydrate-deficient glycoprotein syndrome (CDGS) type Ib. A hereditary
metabolic disease and its therapy].
AB - Underlying the carbohydrate-deficient glycoprotein syndrome (CDGS) type 1b is a
defect in phosphomannose isomerase (PMI), an enzyme of mannose metabolism. The
clinical manifestations include exudative gastroenteropathy, thromboses and
hemorrhages. In contrast to other forms of the CDGS syndrome, neurological
symptoms are completely lacking. The condition responds to a simple dietetic
treatment employing the monosaccharide mannose.
PMID- 10783608
TI - [Phase II ambulatory cardiac rehabilitation (Cologne model). 3 year results after
conclusion of the intervention].
AB - BASELINE: Of a total of 101 patients with CAD who participated in an ambulatory
cardiac rehabilitation program (ACR) ("Cologne model") between 1992 and 1994, 76
(75.2%) were examined 36 months after concluding ACR. RESULTS: The significant
improvement in exercise tolerance from 118.4 +/- 30.1 to 131.9 +/- 34.1 W
achieved with the ACR was maintained at the 3-year examination. ACR also
significantly decreased plasma cholesterol levels from 228.9 +/- 48.3 to 211.7 +/
37.0 mg%; 3 years after ACR the corresponding figures were 219.1 +/- 39.3 mg%.
In the high-risk group the significant reduction in plasma cholesterol levels
from 265 +/- 43.6 to 231.9 +/- 35.4 mg% observed immediately after ACR was
maintained over the three-year period (234.6 +/- 37.7 mg%). Similar patterns were
observed for other parameters of lipid metabolism. Before the cardiac event 63.2%
of the patients smoked; at the 3-year examination the percentage was 30.3%.
Before ACR, 73.7% of the patients were gainfully employed. Within the first 6
months after ACR, 71.4% returned to work, and this percentage increased to 73.2%
after one year. Three years later, 64.3% were still working. DISCUSSION: The
results demonstrate that the lifestyle changes achieved with 4-weeks of ACR may,
at least in part, be maintained over a period of 36 months.
PMID- 10783609
TI - [Individual outcome-oriented cardiologic rehabilitation treatment].
AB - Cardiac rehabilitation and subsequent intensified aftercare is capable, of
increasing the rate of occupational reintegration not only over the short-term,
but also over a period of two years. In addition to improving physical
performance, this enhances the patient's self-confidence, decreases anxiety and
reduces depression. Since, two years after completion of cardiac rehabilitation
and aftercare, the percentage of those lost to gainful employment and in need of
an early pension is appreciably less in the interventional group as compared with
controls, this program would appear to be of particular economic importance for
social security/national insurance carriers. For this reason, the Westphalian
Social Security Carrier has initiated the regular use of this concept in its
cardiological hospitals.
PMID- 10783611
TI - [Amoxicillin/clavulanic acid in therapy of bacterial infections of the diabetic
foot. Results of an observational study].
AB - The results of an observational study of amoxicillin/clavulanic acid (Augmentan)
in 191 patients are presented. The average duration of treatment was 15 days
(median). Healing or improvement was observed in 76% of the cases. In view of the
fact that the condition often has a multifactorial genesis and neural and
vascular changes impair healing, this result must be considered a clinical
success. Variables with an influence on the efficacy of the treatment were the
incidence of manifestation and pathogenesis of the ulcer, renal function, blood
pressure and smoking. Amoxicillin/clavulanic acid was well tolerated, with
adverse events being observed in only 9 out of 193 patients (4.7%). Treatment was
abandoned because of adverse events in 3 out of 193 patients (1.6%). Overall,
treatment of the infected diabetic foot with amoxicillin/clavulanic acid was well
tolerated and effective.
PMID- 10783610
TI - [What do general practitioners expect from a psychiatric clinic? Wish for closer
cooperation].
AB - OBJECTIVE: In the present study the views of family doctors on what constitutes
"ideal" cooperation with a psychiatric hospital were investigated. METHOD: The
views expressed by 24 family doctors and recorded in interviews were analyzed
qualitatively with the aim of assessing their importance. RESULTS: Regular
exchange of information between family doctor and psychiatrist, prompt receipt of
the discharge report, a named contact person on admission and during
hospitalization, competent psychiatric inpatient care, and the possibility of
being able to directly refer patients were felt to be the most important points.
Almost a half of all the views expressed related to intercommunication.
CONCLUSION: Psychiatric hospitals should give more consideration to the views and
wishes of family doctors as a means to resolving possible problems of interaction
and to improving the care afforded mentally sick patients.
PMID- 10783612
TI - [Stage-adapted reconstruction of the stomach after gastrectomy].
AB - The only realistic chance of a cure for cancer of the stomach is gastrectomy with
a wide margin of clearance. The question as to what constitutes the ideal
reconstruction of a substitute stomach, however, remains unanswered. A number of
prospective randomized studies show that patients operated on in curative intent
and with a good long-term prognosis, should be given a substitute stomach in the
form of a pouch constructed from small bowel, with restoration of duodenal
passage. On account of the shorter operating time, patients receiving palliative
surgery should be treated with a simple oesophagojejunostomy without such a small
bowel pouch substitute stomach.
PMID- 10783613
TI - [ALLHAT Study: doxazosin arm is discontinued. Alpha blocker is less effective
than a diuretic].
PMID- 10783614
TI - [Calcium antagonist in heart failure. No improvement, no damage].
PMID- 10783615
TI - [ASS or clopidogrel? In high vascular risk it is best to give both].
PMID- 10783616
TI - [Phytotherapy and homeopathy on the internet. Alternative medicine for physicians
and patients].
PMID- 10783617
TI - [Myocardial infarct--seizure--psychosis. The drug emergency has many faces].
PMID- 10783618
TI - [Fatal fibroelastoma].
PMID- 10783619
TI - [Diabetic retinopathy--screening is a requirement. Don't wait until vision
becomes impaired].
AB - Diabetic retinopathy is the most common systemic disease capable of leading to
blindness. Laser treatment of diabetic retinopathy is standardized; in most cases
it can prevent blindness, provided the diagnosis is made in good time. Since
impairment of vision is a late complication, systemic screening examinations are
of particular importance if we are to reliably determine the optimal time for
treatment. Advances in vitreoretinal surgery make possible the treatment of such
late manifestations as vitreous hemorrhage and tractive retinal detachment.
Provided that stage-oriented and timely treatment is forthcoming, these formerly
hopeless cases should become a rare exception. The currently sole confirmed
medical treatment is optimal control of blood sugar--based on the HBA1c value-
and of blood pressure. The clinical efficacy of inhibitors of angiotensin
converting enzyme or protein kinase C is presently undergoing investigation.
PMID- 10783620
TI - [Management of the diabetic patient. When consult the general practitioner, when
the specialist practice?].
AB - The perception that in type 2 diabetes mellitus the prognosis with regard to
micro-angiopathic and macro-angiopathic complications significantly depends on
the quality of metabolism and the level of the blood pressure, should prompt all
of us to considerably intensify our efforts to ensure optimal treatment for the
diabetic. For example, insulin will have to administered at an earlier time-point
and to a much greater extent than formerly. In order to meet the objectives
specified in the St. Vincent Declaration of 1989, not only close cooperations
between family doctors and diabetologists in specialist practices and hospitals,
but also comprehensive quality control measures will be needed. In new diabetes
contracts, for example the interface model, attempts are being made to take
account of these facts. The various tasks of family doctors and specialized
diabetes practices are discussed on the basis of the interface model.
PMID- 10783621
TI - [Synopsis of vasculitis. When the immune system attacks autologous blood
vessels].
PMID- 10783622
TI - [Unstable angina pectoris: preventing the infarct. Thrombosis ABC, 14].
PMID- 10783623
TI - [An unusual cause for dysphagia. Enlargement of the left atrium].
PMID- 10783624
TI - [Colleagues, return the certification and work only for cash!. Interview by
Werner Loosen].
PMID- 10783625
TI - [Lipid therapy is effective in concomitant risk. In this way statins can be
prescribed in a budget-appropriate manner].
PMID- 10783626
TI - [Diphtheria, tetanus and pertussis. Booster vaccination!].
PMID- 10783627
TI - [No sodium--no pain. New guidelines in bone and muscle pain].
PMID- 10783628
TI - [New concept in chronic heart failure. Blocking the function of tumor necrosis
factor].
PMID- 10783630
TI - [Suggestions about the function of local centers of public health activities].
PMID- 10783629
TI - [A physician who relocated to campaign against epidemic leprosy. Armauer Hansen
discovered leprosy bacteria].
PMID- 10783631
TI - [Factors in continuation of home health care for patients with intractable
neurological diseases].
AB - OBJECTIVE: This study was carried out to elucidate factors related to difficulty
in continuing home health care and to investigate problems of the corresponding
support system for patients with intractable neurological diseases. SUBJECTS AND
METHODS: Subjects were 139 cases of amyotrophic lateral sclerosis (ALS), 376
cases of spino-cerebellar degeneration (SCD) and 1,048 cases of Parkinson's
disease (PD) who were collected from the nationwide survey of health and social
service needs of the patients with intractable diseases in 1995. Factors and
problems related to limited activity due to diseases and necessity for medical
care were analysed. The need for facilities of long-term care was also studied.
RESULTS: The characteristic conditions of patients with ALS were shorter duration
of the illness, higher percentage of conditions requiring medical care and
disorders of swallowing or respiration and full nursing care in daily life
compared with the other two diseases. The characteristics of PD were higher
percentage of female and older age in both patients and their family caregivers.
The proportion of cases for whom health care was judged to be prone to difficulty
was 23.0% in ALS, 10.9% in PD and 7.2% in SCD, respectively. Regarding the
factors related to difficulty in continuing home health care, conditions
requiring medical care, the need for full nursing care in daily life, and the
duration of the illness were recognized in ALS. In SCD, 5 factors, including
conditions requiring medical care, the need for full nursing care in daily life,
patients age greater than 65 years, the duration of the illness, and patients
being nursed by their sons or daughters were detected. In PD, 4 factors, such as
conditions requiring medical care, the need for full nursing care in daily life,
the patients being nursed by persons other than the spouse, and the need of
nursing care were found. CONCLUSION: These results suggest the necessity of
social functions of medical care, nursing and family support that can be supplied
at home effectively according to symptoms in progress, and the need for
facilities of long-term care of patients for whom continuation of home health
care may become difficult, which will work as a support system for long-term care
of patients with intractable neurological diseases.
PMID- 10783632
TI - [Characteristics of "Tojikomori" and "Tojikomerare" among home disabled elderly:
daily life of housebound elderly].
AB - BACKGROUND AND PURPOSE: A Japanese word Tojikomori means shutting oneself in a
room or house, or generally withdrawing. It has been pointed out that Tojikomori
results in a decline in mobility among disabled elderly living at home. As a
result of the qualitative study, we have attempted to define two types of
Tojikomori. The first type, or the narrowly defined Tojikomori, is the elderly
who are housebound-inactive but have a high mobility level. The second type,
Tojikomerare (the passive of Tojikomori), is the elderly who are housebound
inactive because of their low mobility. The purpose of this study is to describe
characteristics of Tojikomori and Tojikomerare. METHODS: 321 disabled elderly
(male: 122, female: 199, mean age 78.8) were interviewed at home by nurses in
Wajima City, Japan, in 1998. The subjects were selected from the list of used in
a screening survey, the Whole Wajima Elderly Survey. Mobility, life space,
activity, physical function, psychosocial factors, caregiver's burden and
caregiver's care to elderly were measured. The Tojikomerare subjects were
operationally defined as the housebound-inactive elderly who were unable to walk.
The Tojikomori were identified as the housebound-inactive elderly who were able
to walk 5 yards but were unable to take a bus. RESULTS: Results obtained were as
follows: 1. Housebound were not found among elders able to go out bus. There were
16 Tojikomori (10.1%) in subjects who were able to walk 5 yards (n = 153). Among
the subjects who were unable to walk (n = 72), 49 people (68.1%) were classified
as Tojikomerare. 2. The physical function, autonomy and social network of the
Tojikomerare subjects were lowest among subjects unable to walk. They used day
care least and received least care from their caregivers. In addition, their
caregivers' burdens were modest. 3. Among the elderly who were able to walk 5
yards, autonomy and social network of the Tojikomori ranked lowest, although
physical function was not low. CONCLUSION: Tojikomerare had lowest physical and
psychosocial function, but they were cared for the least by caregivers.
Tojikomori had the lowest psychosocial function among elderly who can walk 5
yards. The results suggest that it is important to evaluate the mobility, life
space, and activity of the housebound elderly when providing community-based
services.
PMID- 10783633
TI - [Validity and reproducibility of a semi-quantitative food frequency questionnaire
for nutritional education of patients of diabetes mellitus (FFQW65)].
AB - BACKGROUND: A self-administered semi-quantitative food frequency questionnaire
with 65 food lists (FFQW65) was developed for the nutritional education of
patients of diabetes mellitus. METHODS: Relative validity and reproducibility of
nutrient intakes as assessed by FFQW65 were investigated in volunteers of 71
males. To assess the relative validity, a one-week diet record was used as a
reference. The FFQW65 was administered twice at an interval of 10 month in order
to assess the reproducibility. Log transformed data was used to obtain Pearson
correlation coefficients. RESULTS: As for the validity, Pearson correlation
coefficient of total energy intake of breakfast was 0.74 and the relative
difference between predicted value and diet record was relatively small (the
difference was -5 kcal and relative difference rate was 1.1%). Compared with
breakfast, those for lunch, supper and one-day total energy intakes were
relatively lower (0.52, 0.66 and 0.64, respectively) and the relative differences
were around 10%, respectively. The one-day intakes of sixteen nutrients (except
for potassium and niacin) ranged from 0.28 to 0.64. Energy adjusted correlation
coefficients for protein, iron and cholesterol were low (0.16, 0.14 and 0.19,
respectively). Those for the other thirteen nutrients ranged from 0.26 to 0.65.
As for the reproducibility, the second survey using FFQW65 was administered to 64
males. Pearson correlation coefficient of one-day total energy intake was 0.76
and those for the other nutrients ranged from 0.54 (vitamin D) to 0.81 (calcium).
CONCLUSION: The results suggest that FFQW65 can be used for the evaluation of
energy intake by usual meals for nutrition education of patients of diabetes
mellitus.
PMID- 10783634
TI - [Current state and related factors in examinations of those who have had contact
with tuberculosis].
AB - OBJECTIVE: This study investigated the current conditions of identifying
tuberculosis contacts and enforcing their examinations in Public Health Centers
and examined related factors. METHODS: The study subjects were 431 index cases
with tuberculosis who were newly registered between 1995 and 1997 at four Public
Health Centers in Tokyo and Yokohama. Based on case registration card information
and interviews with public health nurses in charge, the data of identification of
contacts and enforcement of examination of their contacts were collected.
RESULTS: The proportion of index cases with insufficient identification of
contacts was 28.3%, particularly the non-family contact data being insufficient.
From logistic regression analysis: index cases aged 20-39 years; contact with
many people; "a moderate risk index of infection" cases; and being homeless were
factors significantly related to insufficient identification of contacts. The
proportion of contacts who were examined in individual contact examinations was
59.1%, that of mass contact examinations was 80.4%. From logistic regression
analysis: negative index cases on sputum smear; and no history of routine health
examinations for the past 3 years or a complete lack of information were factors
significantly related to insufficient enforcement of individual contact
examinations. As to mass contact examinations, not interviewing index cases was a
factor significantly related to insufficient enforcement. Further individual and
mass contact examinations differed in quality according to Public Health Center.
The incidence in close contacts with active tuberculosis was 1.0%, and was
especially high in members of the same household and friends of the newly
diagnosed. CONCLUSIONS: This study showed that the current contact examinations
for tuberculosis are insufficient. In addition it was shown that an adequate
identification of contacts and a complete enforcement of contact examinations are
urgent needs in Japan.
PMID- 10783635
TI - [Inadequate care by family caregiver of frail elderly living at home].
AB - In order to elucidate the present situation and background of inadequate care of
frail elderly living at home by family caregivers, a questionnaire survey was
performed on family caregivers. A total of 408 family caregivers were analyzed.
The major results of this survey were as follows; 1. Thirty two percent of
caregivers were associated with inadequate care. The percentage of main details
of inadequate care were "ignoring" was 19%, "the infliction of mental anguish
(e.g. insulting or verbal aggression)" was 14% and "physical injury (e.g. slap,
pinch or kick)" was 8%. 2. As a result of the analysis of answers to open-ended
questions by caregivers, the reason for inadequate care were classified roughly
into three groups as follows; 1. stress and feelings of the caregiver 2. behavior
or characteristics of the elderly 3. human relationship between the caregiver and
the elderly or the caregiver and the relatives. 3. Frequency of caregiver's
emotion of animosity to elderly were "often" was 3.9%, "sometimes" was 18.1%,
"occasionally" was 39.2%, "rarely" was 22.5%, "none" was 11.5%. The main reason
for animosity were "elderly happened to be angry or complained", "not able to
understand caregivers talk", "irritated due to being busy" or "there is no
feeling of appreciation in the elderly". 4. The relation of inadequate care and
emotion of animosity was large (chi 2 test, P < 0.0001) and correlation of degree
of animosity and experience of inadequate care was linear.
PMID- 10783636
TI - [ADL and actual life styles of all Japanese centenarians as determined by a
visitation interview survey].
AB - A visiting interview survey was performed on all centenarians living in Japan to
investigate their Activities of Daily Life (ADL). 2,851 centenarians, 92.9% of
all subjects completed the interview. They were divided into three groups, good
ADL (almost independent in daily life), moderate ADL (almost independent in
indoor life), and inferior ADL (bed fast) by the condition of ADL. Some factors
of health conditions, family size, frequency of use of public welfare services,
and life styles were compared among these three groups. Both the good and the
moderate ADL groups accounted for about 20% each, and the inferior ADL group was
about 60% of the subjects. The condition of ADL of men was better than that of
women. The inferior ADL group showed a significantly higher percentage of chronic
diseases. High ratios of cerebral vascular disease and dementia were seen in this
group, and many had no teeth. While two thirds of all the centenarians lived at
home, over 90% of the good ADL group lived at home. The mode of family size was
three including the person oneself. An average of 21% of men and 27% of women
used public health welfare services. However 40% of the centenarians in the
inferior ADL group used those services. Men had better dietary habits for health
than women. The good ADL group showed the most desirable dietary habits among the
three groups and had the highest percentage of drinkers and smokers. Men
practiced a greater number of ideal habits for longevity than women. Of the ADL
groups, centenarians in the good ADL group had the highest percentage of ideal
habits for longevity. The centenarians who maintained good ADL had the following
characteristics: There were fewer people under medical treatment. They had
maintained their own teeth. Almost all of them were living at their home with
their family. They had continued good dietary habits and daily life for health
and longevity. For the maintenance and improvement of ADL of centenarians,
adequate social welfare support in a local area for centenarians and their family
seemed to be vital in addition to health management and guidance of healthy life
style of the aged.
PMID- 10783637
TI - [Brain tumors: update 6 years after the publication of the WHO blue book].
PMID- 10783638
TI - [Transmission and scanning microscopy of elastofibroma ultrastructure].
AB - Elastofibroma is a rare benign tumor of soft tissues that has the elective
localization in peri- or interscapular region. It is characterized by the
proliferation of fibroblast-like cells which appear enveloped by abundant elastic
and collagen fibers. Here we present a case of elastofibroma, observed in a 63
year old woman in the interscapular region. The neoformation has been studied by
transmission electron microscopy (TEM) and scanning electron microscopy (SEM).
Our hypothesis is the possibility that elastofibroma is the consequence of active
neoformation of fibers elastic normal in the quality that subsequently is meet to
progressive degenerative phenomenons.
PMID- 10783639
TI - [Central core disease. Report of 2 cases in adults].
AB - "Central core disease" (CCD) is a rare disease of infancy and childhood and
represents the prototypic member of a group of muscular disorders known as
"congenital, benign (non progressive) myopathies". It is very uncommon to
diagnose cases affected by CCD in youth and adulthood. The disease is mainly
familial with a dominant autosomal pattern of inheritance, but sporadic cases are
known to occur. The candidate gene has been localized on chromosome 19q13.1, and
is allelic with RYR-1 ("ryanodine receptor" [calcium release channel gene]), the
gene responsible of the susceptibility to malignant hyperthermia. In some
familial cases of CCD a susceptibility to malignant hyperthermia was also
recognized. The diagnosis is only made based on muscular biopsy, which documents
some peculiar morphological abnormalities, i.e. focal losses of oxidative enzyme
activities, exclusively in type I muscular fibres. The basis for the loss of such
activities is represented by an almost total absence of mitochondria and
sarcoplasmic reticulum in those focal regions of muscle fibres. Cores may be
"structured" and "unstructured" based on the reactivity with myosin ATPases,
which ultrastructurally means preservation or destruction of myofilaments. Both
structured and unstructured cores qualify this disease in the same way. The
authors have observed two cases of CCD in patients in their non infantile age.
Both diagnoses were accomplished by means of muscular biopsy, and the results of
their studies in both cases are herein presented and discussed.
PMID- 10783640
TI - [Cell-block immunocytochemical characterization of effusions. Use of antibody
panel: calretinin, Ber-EP4, keratin and CD68].
AB - An anticorpal panel formed by Calretinin, Ber-EP4, Keratin and CD 68 has been
applied to differentiate mesothelial hyperplasia/mesothelioma from metastastic
carcinoma in cavity effusions. The study was performed in 86 cases in which
paraffinated cell-blocks were obtained. All cases positive for malignancy had
histological confirmation. The series included 2 malignant mesothelioma, 54
reactive mesothelial hyperplasia, and 30 metastatic carcinoma. All cases of
reactive mesothelial showed strong cytoplasmatic positivity for Calretinin, and
hyperplasia negativity for Ber-EP4. The 2 cases of mesothelioma were positive for
Calretinin and negative for Ber-EP4. In contrast, all cases of metastatic
carcinoma had membrane or cytoplasmatic positivity for Ber-EP4. The sensitivity
(100%) and specificity (100%) of reactivity for Calretinin and Ber-EP4 showed
that the immunocytochemical results on paraffin embedded material from cavity
effusions are very reliable, so that the tested immunocytochemical panel can be
useful in cytological differential diagnosis between reactive mesothelial
hyperplasia/mesothelioma and metastatic carcinoma.
PMID- 10783641
TI - [Intestinal brushing. Technical-cytological contribution in the pathological
study of Vater's ampulla, common bile duct, and pancreatic system].
AB - OBJECTIVE: This experience shows the effectiveness of the cytological examination
in the diagnosis of biliary and pancreatic neoplasm on samples obtained from
Vater's papilla through endoscopic intestinal brushing. STUDY DESIGN: From June
1997 to October 1998, 28 patients, suffering from suspicious neoplasm of Vater's
papilla or biliary system, were studied. Each sample was obtained through
intestinal brushing during an Endoscopic Retrograde Colangio-Pancreatography
(ERCP) and processed with the technique of direct smear stained with
Papanicolaou's method. The sample was followed by the corresponding biopsy in 16
cases and by surgical specimens in 8 cases. RESULTS: 27 patients out of 28 were
correctly classified by the intestinal brushing. The method carried out a
positive predictive value of 100% and a sensitivity of 93%. The sensitivity of
biopsy turned out to be 80%. CONCLUSIONS: The intestinal brushing is an effective
method of diagnosis, which turned out to be relevant as a support and, in several
cases, as a substitute of the biopsy. We think, therefore, that the brushing
should be carried out whenever a lesion of the Vater's papilla or of the biliary
system is suspected during an ERCP.
PMID- 10783642
TI - [Orbital embryonal rhabdomyosarcoma in adults. Report of 2 cases].
AB - Rhabdomyosarcoma (RMS) is the most frequent sarcoma of infancy. Embryonal RMS is
generally correlated with a better response to chemotherapy. In the present paper
two cases of embryonal RMS of the orbit affecting adult patients are reported.
Both patients are male, aged 22 and 24 years respectively. In Case 1 the lesion
arose primitively in the orbit, in Case 2 the orbit was affected by secondary
involvement. Both patients presented a rapid response to chemotherapy, with
reduction of the neoplastic mass and regression of symptoms.
PMID- 10783643
TI - [Hypophyseal hyperplasia].
PMID- 10783644
TI - [Cervix adenocarcinoma and squamous cell carcinoma: 2 different morphologic
entities?].
PMID- 10783646
TI - [Luck and genius in research: rethinking about Camillo Golgi 100 years after the
discovery of his apparatus].
PMID- 10783645
TI - [Origin of modern pathologic anatomy: a dangerous misunderstanding].
PMID- 10783647
TI - [Trends in pathology research].
PMID- 10783648
TI - [Randomized double-blind study (third place blinded) to examine the effectiveness
and side effects of methacholine in the nonspecific bronchial provocation test].
AB - Softly and effectiveness of methacholine for the diagnosis of non-specific
bronchial hyperresponsiveness [BHR] were tested in a third place blinded study.
61 patients suspected to suffer from BHR took part. 56 subjects provided complete
data and were included in the study. 27 participants were challenged with
methacholine 0.33% (verum) and 29 patients received NaCl 0.9% (placebo). The
challenge was applied as 5-step-test using a storage bag. The doses were elevated
by doubling the aerosol volume. A positive test result was assumed when basal
specific airway resistance (sRt) reduplicated and simultaneously 2.0 (kPa*s) was
attained. Ten out of 27 subjects in the verum group (33.3%) had a positive test
result whereas in the placebo group only one subject showed a reaction (3.5%). A
statistically significant association between the change of sRt and the
cumulative methacholine dose was confirmed in the verum group (p < 0.002),
whereas this effect could not be observed in patients challenged with placebo (p
= 0.20). Side effects did not occur. We conclude that inhalative challenge with
methacholine 0.33% applied as a 5-step-test is suitable to objectify BHR. The
substantial benefit of the applied test scheme is the short range of time in
which the challenge can be performed (approximately 20 min) and that dilution
series of the test substance (methacholine 0.33%) are not required.
PMID- 10783650
TI - [Proposals for a rationale and for rational diagnosis of coughs].
AB - Cough is probably the most frequent symptom in chest diseases. Hence, a rational
and economical diagnostic procedure is essential to prevent unnecessary costs to
the health services, i.e. acute bronchitis, a self-limiting disease, which is the
most frequent cause for cough should not involve extensive per case costs.
History, physical examination, chest X-ray and lung function testing--which
constitute both the first and second, i.e. the basic level of a stepwise approach
-allows to diagnose causes in most patients with cough. Without evidence of the
cause after completing this basic diagnostic procedure patients with acute cough
may require blood gases analysis, electrocardiography, echocardiography, lung
perfusion study, spiral CT angiography, bronchoscopy or laboratory examinations
for diagnosis of pulmonary embolism, aspiration or (seldom) pleuritis sicca.
Chronic persistent cough (CPC) is diagnosed if the basic standard approach to
chronic cough fails to lead to final diagnosis. Patients will then need further
subtle diagnostic management, i.e. bronchial provocation testing, 24 hour pH
probe, ENT- or neurological examination, high resolution CT of the thorax and
bronchoscopy. We present two algorithms for the rational diagnostic approach to
acute (figure 1) and chronic (figure 2) cough. Each algorithm considers spectrum
and frequency of causes on the one hand, the positive predictive value, costs and
patient discomfort due to the examination on the other. Nonetheless, despite
extensive examination up to 20% of patients suffering from CPC the cause remains
unclear [11]. Frequently, the capsaicin cough challenge test can reveal an
idiopathic upregulation of the cough reflex as the hypothesised underlying
condition. Psychogenic cough however, a rare condition in adults should not
coincide with hypersensitivity of the cough reflex. Inconsistency and low
reproducibility of results of the capsaicin challenge in patients with
psychogenic cough preclude his routine clinical use. In conclusion, the very
common acute bronchitis and the ACE inhibitor-induced cough do not require any
other diagnostic procedure except patient history and physical examination. A
simple basic diagnostic approach will usually allow to evaluate acute and chronic
cough. In the remaining cases the proposed algorithm should be used for best
results and to prevent excessive costs.
PMID- 10783649
TI - [Effect of the long-acting beta-2 agonist inhalant formoterol on the quality of
sleep of patients with bronchial asthma].
AB - BACKGROUND: Patients with asthma bronchiale often complain of exacerbations
during the night. Some anti-asthmatic drugs are known to impair the quality of
sleep. HYPOTHESIS: The study was undertaken to prove the effect of the long
acting, inhaled beta-2-agonist formoterol on the quality of sleep in patients
with mild or moderate asthma bronchiale. METHODS: 20 patients with asthma
bronchiale (15 female, 21-75 years, O 33.3 years) without sleep disorder were
evaluated by polysomnography during 3 nights. After one adaptation night, the
patients were randomly assigned 24 micrograms of formoterol during one and
placebo during the other night. The frequency of respiratory disturbances,
arousals, sleep latency, sleep stages, sleep efficiency, motoric activity, and
subjective impression of sleep quality were compared in both groups. RESULTS:
Respiratory disturbances were less, and the subjective impression of sleep
quality was better with formoterol in 50% of the patients. The objective quality
of sleep was slightly better with formoterol, but not significant (Tab. 1).
CONCLUSIONS: In patients with mild or moderate asthma bronchiale, formoterol does
not impair, probably slightly improves the quality of sleep.
PMID- 10783651
TI - [Two out-of-the-ordinary (?) case reports an asthmatic disease].
AB - This is a report on two cases of asthmatic disease presented to a general
practitioner. After a prolonged course of many years during which the intensity
of asthma varied, Ms K. suffered from constantly recurring exacerbations that
required treatment with systemic corticosteroids. The reason was found to be an
adrenocortical insufficiency suspected to be of iatrogenic origin. After various
treatment attempts an optimal minimal therapy was found resulting in complete
freedom from complaints, namely, a combination of fluticasone and 3 mg
methylprednisolone. However, brief instruction and group training as well as
freedom from complaints remained unsuccessful in keeping the patient compliant.
Mr Pl had been suffering from allergic asthma since early childhood which
escalated in 1982. Beclomethasone diproprionate (BDP) and Budesonid were not
tolerated (hoarseness), so that polypharmacy became necessary. This could only be
reduced after finding out that Flunisolid (Fls) was tolerated, so that
stabilisation was achieved. Complaints were greatly reduced with sole inhalation
of Fls and salbutamol. After having changed over to fluticasone it became
possible to reduce salbutamol as stabilisation progressed, so that salbutamol was
used only if required. Depending on the intensity of allergen exposure,
complaints now occur in February/March only, requiring updating of the therapy in
respect of dosage and number of drugs used. During the remaining part of the year
a minimal therapy using one stroke of 250 micrograms fluticasone was found
sufficient to ensure lasting freedom from complaints. Both patients reduced or
terminated the treatment of their own accord despite freedom from complaints
under minimal therapy and were reconverted to therapy compliance only after the
peak flow values had dropped or the complaints had returned.
PMID- 10783652
TI - [Pathogenesis, diagnosis and therapy of COPD].
PMID- 10783653
TI - [Inhaled prostacyclin and iloprost in severe pulmonary hypertension secondary to
pulmonary fibrosis].
AB - Pulmonary hypertension is a life-threatening complication of lung fibrosis.
Vasodilator therapy is difficult owing to systemic side effects and pulmonary
ventilation-perfusion mismatch. We compared the effects of intravenous
prostacyclin and inhaled NO and aerosolized prostacyclin in randomized order and,
in addition, tested for effects of oxygen and systemic calcium antagonists (CAAs)
in eight patients with lung fibrosis and pulmonary hypertension. Aerosolized
prostaglandin (PG)I2 caused preferential pulmonary vasodilatation with a decrease
in mean pulmonary arterial pressure from 44.1 +/- 4.2 to 31.6 +/- 3.1 mmHg, and
pulmonary vascular resistance (RL) from 810 +/- 226 to 386 +/- 69 dyn.s.cm-5 (p <
0.005, respectively). Systemic arterial pressure, arterial oxygen saturation, and
pulmonary right-to-left-shunt flow, measured by multiple inert gas analysis, were
not significantly changed. Inhaled NO similarly resulted in selective pulmonary
vasodilatation, with RL decreasing from 726 +/- 217 to 458 +/- 81 dyn.s.cm-5. In
contrast, both intravenous PGI2 and CAAs were not pulmonary selective, resulting
in a significant drop in arterial pressure. In addition PGI2 infusion caused a
marked increase in shunt flow. Long-term therapy with aerosolized iloprost (long
acting PGI2 analog) resulted in unequivocal clinical improvement from a state of
immobilization and severe resting dyspnea in a patient with decompensated right
heart failure. We concluded that, in pulmonary hypertension secondary to lung
fibrosis, aerosolization of PGI2 or iloprost causes marked pulmonary
vasodilatation with maintenance of gas exchange and systemic arterial pressure.
Long-term therapy with inhaled iloprost may be life saving in decompensated right
heart failure from pulmonary hypertension secondary to lung fibrosis.
PMID- 10783655
TI - [Phenomenologic and functional variability of violence among children].
AB - Examination of ten-year old children's everyday interactions with peers observed
in natural settings of a school demonstrates that violence was present in many
situations of help, sanctions, and rough-and-tumble play. Thorough analysis
reveals diverse functions of violence in children's interactions: affirmation of
reciprocity and justice, experience of agency and control, preservation of
territories against intruders, clear messages, compensations of lacking
capacities, and defense of the self.
PMID- 10783654
TI - [Surveillance and rehabilitation in asbestos exposure--an underrated problem?].
PMID- 10783656
TI - [Violence in the school--an analysis and prevention].
AB - The "Forschungsgruppe Schulevaluation" (Research Group for School Evaluation,
Technical University of Dresden) conducted several empirical investigations which
led to rich knowledge concerning the amount of violence in schools, the different
forms of violence, roles that actors of and sufferers from violent action play
and the causes for violence. Besides the wellknown socialisatory influence of
families, media consumption and peers for the formation of violent behaviour of
pupils and of behaviour that has an affinity to violence a causal influence of
schools was detected. Questions concerning the prevention of violence, the
conducting of pilot studies on the latter point in one single school as well as
the evaluation of the preventory measures taken were important points in our
work. In the present study we will present the most important empirical results
and our experience with the prevention of violence.
PMID- 10783657
TI - [Violence in the school--imported or self-produced?].
AB - The empirical results of the Bielefeld Research Project "Violence in Schools"
provide information about the kind and frequency of violent behaviors of pupils,
about a possible increase in the level of violence in German schools since the
1970s and about relevant risk factors inside and outside of the school which
influence the number of violent acts committed by pupils. The identification of
specific conditions in different areas of socialization makes it possible to
determine to what degree violence is imported into the school from outside or is
produced from within. On the basis of these findings, recommendations are made
for the prevention of violence in schools.
PMID- 10783658
TI - [Weapons in school--experiences and approaches in Berlin].
AB - On the background of current and often dramatized media reports on the subject of
guns in schools this article deals with acts of violence, with guns which were
discussed publicly last year in Berlin. In addition the authors have included
statistical data from the Berlin school administration on acts of violence at
Berlin schools which were reported 1996 to 1999. These were all incidents where
guns were mentioned. On the one hand detailed analyses of these reports show that
guns are used only exceptionally. On the other hand, surveys among students and
studies on arming in general and also the willingness to arm oneself, which
should be taken seriously, showed a wide-spread feeling of being threatened among
teenagers and especially male teenagers try to prepare themselves this. With the
example of Berlin this article describes which measures the school administration
uses in view of increasing offences committed by children and teenagers regarding
concrete acts of violence. Recommendations on steps appropriate to dealing with
incidents with gun threats and what kinds of resources schools can turn to in
cases of serious acts of violences are also included in this article. In the end
it becomes clear that schools free of guns and violence can only be realized if
children, youths and teachers can count on parents, media and the politically
responsible to reliably support this goal.
PMID- 10783660
TI - [Two cases of classical polyarteritis nodosa associated with a low titre of MPO
ANCA].
AB - We studied two autopsy cases, each with a low titre of myeloperoxidase anti
neutrophil cytoplasmic antibody (MPO-ANCA) associated with systemic vasculitis.
It was difficult to distinguish these cases from classic polyarteritis nodosa.
The patients had suffered from continuous fever, malaise, and weight loss:
however, their renal insufficiency was clinically mild over the course of their
disease. The patients were diagnosed initially as having MPO-ANCA-associated
vasculitis and were treated with prednisolone. Their clinical status improved,
but unfortunately, they died of an infectious disease. Autopsies revealed
systemic vasculitis in small arteries with no signs of necrotizing and crescentic
glomerulonephritis. Our pathologist subsequently diagnosed both cases as classic
polyarteritis nodosa. Systemic vasculitis associated with MPO-ANCA is usually
considered to be a microscopic polyarteritis. However, classic polyarteritis
nodosa should always be considered as a possibility for those patients with mild
renal insufficiency and a low titre of MPO-ANCA.
PMID- 10783659
TI - [Therapeutic effect and clinical findings in patients with MPO-ANCA associated
vasculitis syndrome].
AB - We investigated to clarify the clinical findings, course and therapeutic effect
in the patients with MPO (myeloperoxidase)-ANCA (anti-neutrophil cytoplasmic
antibody) associated vasculitis syndrome. We analyzed clinical findings and data
of 19 cases of MPO-ANCA associated vasculitis. These patients were diagnosed with
clinical symptoms (fever, arthralgia, body weight loss, etc.), laboratory data
(high titer of CRP, leukocytosis, thrombocytosis, and high titer of MPO-ANCA) and
pathologic findings of necrotizing vasculitis. They were 14 male and 5 female
aged 18 to 84 years (mean 65 years) and were treated with prednisolone and
immunosuppressive agents, and additional therapy included pulse therapy and
plasma exchange. Seven cases were dead within 3 months. Post-mortum examination
showed that these cases died of pneumonitis, cerebral events and gastric
bleeding. There was no mortal case induced by over-immunosuppression. In survival
cases, the MPO-ANCA levels decreased rapidly after these therapies and these
antibodies were maintained low levels (360 to 25 EU/l). Comparison of fatal cases
and survival cases, there were difference in the initial dose of prednisolone (27
mg/day vs. 56 mg/day), the ratio of double filtration plasmapheresis (14% vs.
42%), and the ratio of immunosuppressive therapy (14% vs. 83%). The measurement
of MPO-ANCA is useful makers of the diagnosis and effectiveness of the therapy in
patients with MPO-ANCA associated vasculitis. We recommend the aggressive
therapy, including prednisolone, immunosuppressive agents and plasma exchange for
MPO-ANCA associated vasculitis. We believe that the aggressive therapy improve
the survival rate of the patients with MPO-ANCA associated vasculitis.
PMID- 10783661
TI - [The radiographic report of soft tissue tumor on the legs in a case of cutaneous
polyarteritis nodosa].
AB - A 55-year-old male was admitted to our hospital because of arthralgia, rash, and
painful tumor in the legs. On admission, skin lesions involving dark erythematous
macules and a tender mass of 3 by 5 cm were present. Laboratory findings included
hemoglobin of 11.2 g/dl, white blood cell count of 6200/microliter, erythrocyte
sedimentation rate (ESR) of 88 mm/hour, and normal results of renal function
tests. Hepatitis B surface antigen, anti-nuclear antibody (ANA), and perinuclear
pattern antineutrophil cytoplasmic autoantibody (ANCA) were negative. A T 1
weighted magnetic resonance image (MRI) showed iso-intensity areas that increased
in intensity on T 2-weighted images of the M. gastrocnemius. The angiographic
appearance of tumor staining with some degree of luminal irregularity in the
posterior tibial artery suggested a diagnosis of soft tissue neoplasm. Biopsy
specimens of the right leg lesion were consistent with necrotizing arteritis of
both small and medium-sized vessels. Treatment with prednisolone and
cyclophosphamide resulted in the disappearance of the skin lesions and the
improvement of laboratory data. At first, classical polyarteritis nodosa was
considered histologically. However, lesions were limited to skin, muscles, and
joints, and there has been no evidence of systemic disease for 1.5 years;
consequently, cutaneous form of polyarteritis nodosa was diagnosed. Reports of
soft tissue tumors on the legs of patients with polyarteritis nodosa are quite
rare. The interesting radiographic findings of cutaneous polyarteritis nodosa
were reported.
PMID- 10783662
TI - [Antiphospholipid antibody-associated hemophagocytic syndrome].
AB - Autoimmune diseases such as systemic lupus erythematosus (SLE) are known to be
causative disorders of reactive hemophagocytic syndrome (HPS). We recently
encountered a case of HPS associated with the presence of antiphospholipid
antibodies (aPL). This patient showed severe thrombocytopenia (0.2 x
10(4)/microliter) and moderate anemia (Hb; 7.6 g/dl). Bone marrow smears showed
normal cellularity and an increase in mature-looking histiocytes scattered among
the hematopoietic cells, which accounted for approximately 3% of all nucleated
cells and were distributed unevenly. These cells showed marked phagocytosis of
hematopoietic cells, including megakaryocytes, erythroblasts, and a few
neutrophils. In this patient, there is no possible causative factor of HPS (such
as viral infection, lymphoma, and systemic lupus erythematosus) except the
presence of aPL. There have been no previously reported cases describing the
relationship between aPL and HPS. This case indicate that attention should be
given to the possibility that certain patients with aPL-associated cytopenia may
display accompanying intramedullary hemophagocytic phenomena.
PMID- 10783663
TI - [Two cases of rheumatoid arthritis associated with IgA -type multiple myeloma].
AB - We report here two Japanese cases of rheumatoid arthritis (RA) associated with
IgA [symbol: see text]-type multiple myeloma (MM). Case 1. The patient was a 68
year-old man with eight-years history of RA. The M-proteinemia (IgA 2838 mg/dl)
in laboratory findings suggested a complication of MM which had been noticed
since four years ago. On May 1997, he was referred and admitted to our hospital
because of cough, right chest pain and dyspnea. Serum immunoelectrophoresis
showed monoclonal IgA[symbol: see text]-type light chain. Bone marrow aspirate
contained 6.5% atypical plasma cells. The X-ray findings revealed radiolucent
myelomatous foci in the skull. From these findings, IgA[symbol: see text]-type MM
was diagnosed. His condition was recovered by administration of antibiotics for
bacterial pleuritis. Case 2. The patient was a 75-year-old woman with twelve
years history of RA. The laboratory findings of M-proteinemia (IgA 1215 mg/dl)
with the decrease of other serum immunoglobulin level (IgG 611 mg/dl, IgM 60
mg/dl) and monoclonal IgA[symbol: see text]-type light chain in serum
immunoelectrophoresis suggested MM four years ago. Bone marrow aspirate contained
5% plasma cells. From these findings, IgA[symbol: see text]-type MM was
diagnosed. In the review of reported Japanese cases of RA associated with MM, it
might be characteristic that IgA type MM was found more frequently in RA patients
than other immunoglobulin types.
PMID- 10783664
TI - [Osteoclastic bone resorption in joint destruction of rheumatoid arthritis].
PMID- 10783665
TI - [Dermatological aspects on systemic sclerosis].
PMID- 10783666
TI - [Revised Japan criteria for Sjogren syndrome].
PMID- 10783667
TI - [Study on Japan Rheumatism Association diagnostic criteria for early rheumatoid
arthritis. Prospective evaluation of diagnostic criteria for early rheumatoid
arthritis].
PMID- 10783668
TI - [Nonsurgical occlusion of an atrial septal defect in childhood: initial Swiss
experiences].
AB - The initial experience with catheter closure of an atrial septal defect (ASD) in
children, performed at two Swiss centers is presented. The ASD closures were
performed according to international multicenter study protocols. 14 children,
aged 3.9-17.5 years underwent closure by catheter. The defect size varied between
12 and 22 mm (balloon sized), the ratio between pulmonary and systemic blood flow
showed a mean of 2.2 (1.5-3.5). Catheter closure was done using three different
occlusion devices. More recently only the Amplatzer occluder was used at both
institutions. In 12 children (86%) defect closure was successful and after a
follow-up of 3-32 months (mean 17) only one child had a trivial residual
interatrial shunt. In all children, echocardiographic follow-up showed an
unchanged and correct device position on both sides of the atrial septum. In two
children, a floppy aortic segment of the atrial septal rim led to instable device
position: both children underwent surgical defect closure later. The children
with successful device closure showed no complications during the catheterization
or during follow-up. There were no thrombotic complications on the surfaces of
the devices. Catheter closure of an ASD during childhood is a safe and efficient
alternative to standard surgical treatment.
PMID- 10783669
TI - [Value of ultrasound study and dual energy x-ray absorptiometry (DEXA) for
assessment of risk of osteoporosis].
AB - Screening postmenopausal women for preventing osteoporosis at an early stage is
the main topic of several studies. The present paper evaluates the place of
ultrasound measurements in comparison with Dual Energy X-ray-absorptiometry
(DEXA). METHODS: 247 women (41 women < or = 50 yrs, 103 women 50-60 yrs, 103
women > 60 yrs) underwent DEXA of the vertebrae and hip and concommittantly
ultrasound measurements of the calcaneus. RESULTS: The DEXA values in the
vertebral column vary considerably and are lowest in L1 and highest in L4. The
femur on the other hand shows lowest values in the Ward triangle (T = -1.6 SD),
and highest in the trochanter (T = -0.3 SD). Speed of sound (SOS) gives lower T
values (-1.2 SD) than broadband ultrasound attenuation (BUA) (-0.3 SD).
Statistical analysis (Spearman, Pearson) shows no correlation between ultrasound
and DEXA measurements and therefore do not permit analogies between hip and
vertebral column and vice versa. CONCLUSIONS: Our data show that the fracture
risk of an individual woman can be adequately ascertained only by DEXA
measurement of vertebrae and femur. Ultrasound measurement today cannot be
recommended as routine screening or diagnostic method.
PMID- 10783670
TI - [Differential diagnosis of unilateral hearing loss].
AB - There are two main kinds of hearing disorders: sensorineural and conductive.
Sensorineural hearing loss is a common disorder that results from damage to the
inner ear in over 95% of all cases; therefore, retrocochlear hearing disorders
are rare and cannot be differentiated from sensory losses by clinical symptoms
alone. Unilateral hearing loss entails many problems in hearing during the entire
life of the affected patients. Conductive deafness has a readily determined
etiology in most cases. In contrast, unilateral sensorineural hearing loss
requires more refined and extensive investigation. The etiology of an asymmetric
sensorineural hearing loss can often be difficult to determine. Because a wide
variety of pathologic processes may be responsible for the hearing loss, numerous
diagnostic tests are usually used during initial evaluation, including pure-tone
audiometry, acoustic reflex testing, imaging, serologic testing, and auditory
brainstem response testing. The most frequent causes of unilateral sensorineural
hearing loss were sudden deafness, Meniere's disease and cerebellopontine angle
tumors. Early diagnosis of acoustic neuroma or other lesions of the internal
auditory meatus or cerebello-pontine angle requires special attention. The
patient with an acoustic neuroma may present to the otologist with a variety of
clinical features. Classically these include a retrocochlear pattern of
sensorineural hearing loss, reduced vestibular response on caloric testing and a
pathological auditory brainstem response. Magnetic resonance imaging offers
greater specificity than computed tomography. Therapy of unilateral sensorineural
hearing loss includes efforts to treat known causes either medically or
surgically.
PMID- 10783671
TI - [Retrosternal pressure, dyspnea and palpitations. Small cell bronchial
carcinoma].
PMID- 10783672
TI - Results of revision total knee arthroplasty.
AB - BACKGROUND/AIM OF STUDY: The results of primary total knee arthroplasties have
improved over the years but some still fail, requiring revision. Revision total
knee arthroplasty is technically more difficult and has not enjoyed the same
success rates as the index operation. The aim of this retrospective study was to
review the results of revision total knee arthroplasties carried out at our
centre. This is the first study in Singapore on revision total knee arthroplasty.
METHODS: A retrospective study where 17 patients (18 knees) had been followed up
since their revision operations were clinically assessed. Based on the Knee
Society Clinical Scoring System, they were assigned separate knee and function
scores (each having a maximum possible 100). RESULTS: The mean knee score was 76
(range 35-93), which rates as good. Of the 18 knees, 67% had excellent or good
knee scores. By comparison, the mean function score was 56 (range 0-90) which
rates as poor and 33% had excellent or good function scores. CONCLUSION: Revision
total knee arthroplasty achieves good and excellent results in spite of technical
difficulties often associated with the revision operation. The difference in mean
knee and function scores emphasises that many other factors such as physical
strength and stamina affect function. Nevertheless, 15 patients were able to walk
out of their house and around their neighbourhood for varying distances. This
satisfied their expectations and the poor mean function score may reflect
different expectations of patients overseas from whence this scoring system
originated.
PMID- 10783673
TI - Effects of an ethanolic extract of Gynura procumbens on serum glucose,
cholesterol and triglyceride levels in normal and streptozotocin-induced diabetic
rats.
AB - AIM OF STUDY: The aim was to demonstrate the effects of the leaves of Gynura
procumbens (Lour.) Merr. on blood sugar and lipid levels in experimental animals.
METHODOLOGY: We obtained an ethanolic extract of the leaves of G. procumbens and
monitored the effects of an oral administration of (i) different single doses of
the extract on oral glucose tolerance in streptozotocin-induced diabetic and
normal rats and (ii) fourteen doses over 7 days on serum cholesterol and
triglyceride levels in streptozotocin-induced diabetic rats. Metformin and
glibenclamide were used as positive control drugs. RESULTS: The extract, at
single doses of 50, 150 and 300 mg/kg orally, significantly suppressed the
elevated serum glucose levels in diabetic rats; 150 mg/kg was found to be the
optimum hypoglycaemic dose. The extract however did not significantly suppress
the elevated serum glucose levels in normal rats, unlike glibenclamide.
Metformin, but not glibenclamide, improved glucose tolerance in the diabetic
rats. When the optimum dose was given to diabetic rats for 7 days, the extract
significantly reduced serum cholesterol and triglyceride levels in these rats.
CONCLUSION: These results indicate that the leaves of G. procumbens may have
biguanide-like activity.
PMID- 10783674
TI - Surgical approach and results of surgery in adenocarcinoma of the gastro
oesophageal junction.
AB - AIM OF STUDY: This paper attempts to determine the appropriate surgical procedure
in relation to the pathological types of adenocarcinoma of the gastro-oesophageal
junction in Singapore. METHODS: Data on population characteristics, clinical
presentation, pathology, surgical procedures and results of treatment were
gathered from the case records of a personal series of 32 patients resected for
adenocarcinoma of the gastro-oesophageal junction. RESULTS: The 32 patients with
adenocarcinoma of the gastro-oesophageal junction (Type I, 9; II, 20 and III, 3),
presented at a late stage (Stage I-II, 5; III, 14; IV, 13). In 19 patients with
Stages I-III disease, attempted curative surgery was performed--extended total
gastrectomy for Types II and III disease (13 patients) and oesophagectomy for
Type I (6 patients). There was one operative mortality following curative
resection. Palliative resection was performed on 13 patients with Stage IV
disease with one operative mortality. The main operative morbidity was
anastomotic leakage, occurring in 5 patients; both operative deaths were
associated with this complication. The actuarial 5-year survival was 20%.
CONCLUSION: Although gastro-oesophageal cancer presents late, it can be resected
safely by extended total gastrectomy for Types II and III disease and
oesophagectomy for Type I disease, taking precautions to minimise anastomotic
leakage. Although usually palliative, Stages I and II and to a lesser extent
Stage III, are curable by these surgical procedures which ensure a tumour free
surgical margin and adequate lymphadenectomy.
PMID- 10783675
TI - The diagnostic yield of pleural fluid cytology in malignant pleural effusions.
AB - BACKGROUND: The development of a pleural effusion in a patient with a known
malignancy often raises the possibility that the effusion is due to malignant
involvement of the pleura. Accurate diagnosis of the cause of the pleural
effusion in such a patient is essential as the treatment and prognosis may vary.
Currently, thoracentesis and cytologic analysis of pleural fluid cytology is
usually the initial diagnostic step. AIM: To assess the diagnostic yield of
pleural fluid cytologic examination in patients with suspected malignant pleural
effusions seen at our centre. METHODS: Retrospective review of the results of
pleural fluid cytologic examination performed on 103 patients who presented with
suspected malignant pleural effusions. RESULTS: The underlying malignancies in
these patients were as follows: bronchogenic carcinoma (51.5%), breast carcinoma
(29.1%), hepatocellular carcinoma (1.9%), carcinoma of the stomach (1.9%),
malignant mesothelioma, nasopharyngeal carcinoma, renal cell carcinoma, carcinoma
of the oesophagus, lymphoma, carcinoma of the colon (1% each), unknown (9.7%).
Initial pleural fluid cytology was positive for malignancy in 48.5% of patients.
The yield of this diagnostic procedure was improved with repeated pleural fluid
cytologic specimens and when combined with a percutaneous pleural biopsy. There
was no statistically significant difference in the clinical features and pleural
fluid characteristics of patients with malignant pleural effusions and those in
whom the pleural effusions were paramalignant. CONCLUSION: Pleural fluid
cytologic examination is a useful initial step in the diagnostic work-up of
patients with suspected malignant pleural effusions. The diagnostic yield of such
examination is improved with repeated pleural fluid cytologic specimens and when
combined with a percutaneous pleural biopsy. Clinical presentation and pleural
fluid characteristics were inadequate in differentiating between malignant and
paramalignant effusions.
PMID- 10783676
TI - Flashlamp-pumped pulsed dye laser (585nm) for the treatment of portwine stains--a
study of treatment outcome in 94 Asian patients in Singapore.
AB - BACKGROUND: This is a report of a prospective study on the treatment outcome of
94 Asian skin Types III and IV patients with port-wine stains with the 585 nm
flashlamp-pumped pulsed dye laser in Singapore. RESULTS: All patients had
completed at least 1 year of follow-up post treatment and had received treatment
at 8-12 weekly intervals under topical lodocaine-prilocaine anaesthesia. Our
patients received an average of 4 treatments sessions. At the end of each
treatment (8-12 weeks after the last laser treatment/before the next laser
treatment) and on completion of the last treatment (8-12 weeks after the final
laser treatment), patients were assessed for response based on a subjective
scoring system where excellent = > 75% improvement, good = 50% to 75%
improvement, fair = 25% to 49% improvement and poor = < 25% improvement and the
same = no observable improvement. The dermatologist also recorded scores after
each treatment in a similar way. On completion of the final treatment, patients
were asked to score (8-12 weeks after the final laser treatment) the overall
response to the treatment themselves using the same scoring system. The mean age
was 26.4 years (range 1 year to 58 years). The mean initial treatment energy
density dose was 6.24 J/cm2. Eighty percent of our patients experienced excellent
or good response to treatment after the initial treatment and further
improvements were observed with each subsequent treatment. RESULTS: The author
scored 86% of our patients having "excellent" or "good" response while 83% of our
patients scored "excellent" or "good" response upon completion of their
treatment. The dermatologist generally recorded better improvement scores than
the patients. The dermatologist scored 36% and 50% of our patients having
"excellent" and "good" response respectively. The corresponding treatment
response scores by our patients were 22% ("excellent") and 61% ("good").
CONCLUSION: Macular lesions appear to respond better than papular/nodular
lesions, but the difference was not statistically significant probably due to the
small study cohort. Light coloured port-wine stains tended to respond better to
treatment than darker lesions (not statistically significant), but overall, all
colour lesions responded well to treatment. Patients' expectation of improvements
was generally higher than the dermatologist's.
PMID- 10783677
TI - Adolescent pregnancies managed at KK Hospital.
AB - AIM OF STUDY: The aim was to analyse the pregnancy outcome among girls, aged 17
and below, at KK Hospital. METHODOLOGY: This is a retrospective study. A total of
108 adolescent pregnancies were analysed with regards to pregnancy order,
antenatal complications, mode of delivery and pregnancy outcome. RESULTS: The 2
most common antenatal complications were anaemia and preterm labour. The repeat
pregnancy rate was 15.7%. Vaginal delivery was achieved in 7.2%; 21.2% of babies
born weighed less than 2.5 kg. CONCLUSIONS: Adolescent pregnancies accounted for
only a small proportion of all deliveries in our hospital. Late or non-existent
antenatal care was a feature in most pregnancies. The incidence of repeat
pregnancies reflects the need for a more effective counselling on contraception.
PMID- 10783678
TI - Giant cell arteritis causing bilateral sequential anterior ischaemic optic
neuropathy--a case report.
AB - Giant cell arteritis is a chronic granulomatous inflammation of unknown aetiology
involving large and medium size arteries in the elderly. It causes acute visual
loss from ischaemia to the optic nerves or central retinal artery occlusion. This
is a rare cause of anterior ischaemic optic neuropathy in our local population.
We present a patient who had bilateral loss of vision from sequential arteritic
ischaemic optic neuropathy. She was treated with intravenous steroids
immediately. Diagnosis was based on histopathological studies of temporal artery
biopsies.
PMID- 10783679
TI - Morbidity after a bite from a 'non-venomous' pet snake.
AB - We report the first recorded case of morbidity from the bite of a red-neck
keelback snake (Rhabdophis subminiatus) from South East Asia. This is a species
of the Colubrid family which originated from South East Asia. Severe envenomation
from this snake was reported as poisonous in the West as far back as 1978 but it
is still being classified as non-venomous. This classification led our patient to
keep this 'harmless' snake as a pet. We recommend that this snake be reclassified
as 'venomous' or at least warnings be issued to the public not to keep it as a
pet.
PMID- 10783680
TI - Hybrid cardiac revascularisation surgery.
AB - Currently, 3 methods of myocardial revascularisation are available for the
treatment of coronary artery disease: i) coronary artery bypass grafting (CABG);
ii) percutaneous transluminal coronary angiography (PTCA), and iii)
transmyocardial laser revascularisation (TMR). Until recently, these procedures
were performed exclusive to one another. We report 2 cases of minimally invasive
direct coronary artery bypass grafting with subsequent PTCA, and 1 case of staged
PTCA followed by TMR performed at our institution. We discuss the role of hybrid
procedures in the current era of treatment of ischaemic heart disease.
PMID- 10783681
TI - An unusual manifestation of severe caustic injury.
AB - Knowledge of the sequelae of caustic ingestion is of relevance to staff of the
Emergency Room, Intensive Care Unit, surgical and gastroenterology services. It
poses a considerable management problem and may result in life-threatening
complications such as visceral perforation. This case report demonstrates an
unusual and previously unreported manifestation of caustic injury.
PMID- 10783682
TI - Inferior vena cava filters--percutaneous insertion?
AB - The incidence of deep venous thrombosis (DVT) and pulmonary embolism (PE) among
Chinese is much lower than in Caucasians. The total number of inferior vena cava
(IVC) filters inserted in regional hospitals in Canada (about 700 beds in Toronto
General Hospital) and Hong Kong (about 1,250 beds in Pamela Youde Nethersole
Eastern Hospital) also reflects this. Thirty-six IVC filters were deployed in
Toronto General Hospital, compared to 8 IVC filters inserted in Pamela Youde
Nethersole Eastern Hospital from August 1997 to September 1998. Despite this, the
physician may encounter patients with thromboembolic disease who require inferior
vena cava interruption. The usual indication will be pulmonary embolism with
contraindications to, or failure or complications of, anticoagulation therapy. It
is important for angiographers to be familiar with the technique of percutaneous
insertion of IVC filters. The types of IVC filters, techniques of insertion and
guidelines relating to the choice of a filter would be discussed.
PMID- 10783683
TI - Clinics in diagnostic imaging (45). Osmotic myelinolysis ( central potine
myelinolysis).
AB - A 65-year-old woman developed progressive neurological deterioration following
rapid correction of hyponatremia. Magnetic resonance imaging showed T2
hyperintense areas in the central pons, basal ganglia and deep white matter,
typical of osmotic myelinolysis (OM). Previously thought to be uniformly fatal,
there are increasing reports of non-fatal cases of OM. The recognition and
understanding of this entity is important to prevent or reduce the incidence of
its occurrence, as there is no specific treatment once it develops. The clinical
and radiological features of OM are reviewed.
PMID- 10783684
TI - Medical milestones of the last millennium.
PMID- 10783685
TI - The death of the party. All the rave, GHB's hazards go unheeded.
PMID- 10783686
TI - Tampon safety. TSS now rare, but women still should take care.
PMID- 10783687
TI - Your medicine cabinet needs an annual checkup, too.
PMID- 10783688
TI - Science at FDA. The key to making the right decisions.
PMID- 10783689
TI - Two companies caught in fish fraud case.
PMID- 10783690
TI - Models of nursing care: a century of vacillation.
PMID- 10783691
TI - Where will tomorrow's nurse managers come from?
PMID- 10783692
TI - Tips for successful merger integration.
PMID- 10783693
TI - Nurses' perceptions. Is your nurse uncomfortable or incompetent?
PMID- 10783694
TI - The demise of nursing administration programs. Reaction to the reaction!
PMID- 10783695
TI - Japan's healthcare system.
PMID- 10783696
TI - Nursing future search. Building a community of nurses in an integrated healthcare
system.
AB - Many models and approaches are available to manage change and plan for the
future. Large group intervention is one approach to tapping the collective wisdom
of a nursing system facing formidable adaptive challenges. Large group
interventions involve many people, and they include open sharing of information,
group problem-solving, participation, and sharing of power to create a shared
future. One model for creating a vision for the future is called "Future Search".
In this article, we describe the methodology of Future Search as a model to plan
for change. A case study illustrates the use of a Nursing Future Search by an
integrated, not-for-profit healthcare organization in northern Virginia. Results
and the outcomes of a 6-month follow-up conference reveal nine planning groups
that are moving a community of nurses to action.
PMID- 10783697
TI - Values expressed in philosophies of nursing services.
AB - Do nurses value "caring"? Does it matter that nurses respect individual rights
while caring for groups of patients? What values are shared by nurses and are
they evident in institutions? How important are nursing values in a changing
healthcare system? Should nurse administrators ensure that nursing values remain
integral to managed care? What is the nurse's responsibility for communicating
nursing values throughout the organization? The authors discuss the values
expressed in nursing service philosophies and how they reflect a changing
healthcare system.
PMID- 10783698
TI - Intuition in professional practice. Executive and staff perceptions.
AB - Intuition, as part of our thinking, is often misunderstood or held in mystical
regard. It is important to understand the aspects of this instinctual process and
to appreciate the differing perspectives of both the registered nurse in the
staff position and the executive in a leadership role. We compare responses to a
Socratic dialogue of the definition of intuition and offer suggestions for
nursing leaders to develop clinical judgment using nursing examples of intuition.
PMID- 10783699
TI - Hospital networking. Comparing the work of nurses with flexible and traditional
schedules.
AB - OBJECTIVE: This research study was conducted to contrast workplace socialization
of nurses working flexible (flex) and traditional schedules in an acute care
setting. The study illustrates the types of social networks used by both types of
nurses in a reengineered healthcare environment. SUMMARY BACKGROUND DATA:
Reengineering strategies, such as flex nurse staffing, add a new dimension to
workplace change and adaptation. Few studies have examined the similarities and
differences between nurses working flex and traditional schedules. The research
literature shows that workplace socialization significantly affects job
satisfaction, organizational commitment, and retention. No studies have examined
how the process of socialization--forming social networks--differs for nurses
working traditional or flex schedules. METHODS AND SUBJECTS: A convenience sample
of 120 nurses working traditional schedules and 46 nurses working flex schedules
from a pediatric, tertiary care setting completed the Social Network
Questionnaire (SNQ), a standardized instrument that records individuals' social
network composition and function. RESULTS: No significant differences were found
in the nurses' social network composition. Both types of nurses constructed peer
based networks and nurse managers were also present in their networks. Nurses
working traditional schedules used significantly more peer members for different
types of emotional support, such as reassurance and handling emotional upsets.
CONCLUSIONS: Workplace networks are important to both types of nurses. Nurses on
flex schedules may form less social attachments in order to manage the increased
demands of moving among multiple units. This group of nurses can provide clues
for adaptive change in reengineered environments.
PMID- 10783700
TI - Redesigning financial management education for the nursing administration
graduate student.
AB - The changes and expansion in the nurse administrator role indicate a need for a
specialized body of financial knowledge and skills for making system focused
decisions that integrate the clinical and business aspects of healthcare. A
survey of nurse administrators and chief executive officers showed high agreement
on the important financial management concepts to the nurse administrator role. A
graduate level financial management course that includes concepts for course
content and practice applications is proposed.
PMID- 10783701
TI - [Homage to Professor J.-Andre Thomas (1905-1999)].
PMID- 10783702
TI - [Animal toxins and ion channels].
AB - Animal venoms contain various toxins which act on ion-channels, responsible for
either sodium, potassium, calcium or chloride permeation. Structure determination
of these toxins demonstrate that they are organised around two different
structural motifs: potassium and sodium channel effectors are organised around an
alpha-helix connected by two disulfide bridges to a two- or three-stranded beta
sheet whereas calcium channels effectors are structured around an "Inhibitory
Cystine Knot" motif made of a dense disulfide-rich core from which emerge several
loops. Analysis of local structural modifications allows us to understand the
structural basis of the selectivity of these effectors towards the various ion
channels. This is the first step in the design of new synthetic molecules which
are potent therapeutic drugs for diseases involving ion channel dysfunctioning.
PMID- 10783703
TI - [Bacterial toxins: useful for studying G-proteins implicated in the mechanism of
exocytosis in neuroendocrine cells].
AB - In neuroendocrine cells, regulated exocytosis is a multistep process that
comprises the recruitment and priming of secretory granules, their docking to the
exocytotic sites, and the subsequent fusion of granules with the plasma membrane
leading to the release of secretory products into the extracellular space. Using
bacterial toxins which specially inactivate subsets of G proteins, we were able
to demonstrate that both trimeric and monomeric G proteins directly control the
late stages of exocytosis in chromaffin cells. Indeed, in secretagogue-stimulated
chromaffin cells, the subplasmalemmal actin cytoskeleton undergoes a specific
reorganization that is a prerequisite for exocytosis. Our results suggest that a
granule-bound trimeric Go protein controls the actin network surrounding
secretory granules through a pathway involving the GTPase RhoA and a downstream
phosphatidylinositol 4-kinase. Furthermore, the GTPase Cdc42 plays a active role
in exocytosis, most likely by providing specific actin structures to the late
docking and/or fusion steps. We propose that G proteins tightly control secretion
in neuroendocrine cells by coupling the actin cytoskeleton to the sequential
steps underlying membrane trafficking at the site of exocytosis. Our data
highlight the use of bacterial toxins, which proved to be powerful tools to
dissect the exocytotic machinery at the molecular level.
PMID- 10783704
TI - [Analysis of synaptic neurotransmitter release mechanisms using bacterial
toxins].
AB - Several bacterial toxins are powerful and highly specific tools for studying
basic mechanisms involved in cell biology. Whereas the clostridial neurotoxins
are widely used by neurobiologists, many other toxins (i.e. toxins acting on
small G-proteins or actin) are still overlooked. Botulinum neurotoxins (BoNT,
serotypes A-G) and tetanus neurotoxin (TeNT), known under the generic term of
clostridial neurotoxins, are characterized by their unique ability to selectively
block neurotransmitter release. These proteins are formed of a light (Mr
approximately 50) and a heavy (Mr approximately 100) chain which are disulfide
linked. The cellular action of BoNT and TeNT involves several steps: heavy chain
mediated binding to the nerve ending membrane, endocytosis, and translocation of
the light chain (their catalytic moiety) into the cytosol. The light chains each
cleaves one of three, highly conserved, proteins (VAMP/synaptobrevin, syntaxin,
and SNAP-25 also termed SNAREs) implicated in fusion of synaptic vesicles with
plasma membrane at the release site. Hence, when these neurotoxins are applied
extracellularly, they can be used as specific tools to inhibit evoked and
spontaneous transmitter release from certain neurones whereas, when the membrane
limiting steps are bypassed by the mean of intracellular applications, BoNTs
orTeNT can be used to affect regulated secretion in various cell types. Several
members of the Rho GTPase family have been involved in intracellular trafficking
of synaptic vesicles and secretory organelles. As they are natural targets for
several bacterial exoenzymes or cytotoxins, their role in neurotransmitter
release can be probed by examining the action of these toxins on
neurotransmission. Such toxins include: i) the non permeant C3 exoenzymes from C.
botulinum or C. limosum which ADP-ribosylate and thereby inactivate Rho, ii)
exoenzyme S from Pseudomonas aeruginosa which ADP-ribosylates different members
of the Ras, Rab, Ral and Rap families, iii) toxin B from C. difficile which
glucosylates Rho, Rac and CDC42, iv) lethal toxin from C. sordellii which
glucosylates Rac, Ras and to a lesser extent, Rap and Ral, but not on Rho or
CDC42, and v) CNF deamidases secreted by pathogenic strains of E. coli which
activate Rho and, to a lesser extent, CDC42. Since these toxins or exoenzymes
have no or little ability to enter into the neurones, they must be applied
intraneuronally to bypass the membrane limiting steps. Injection of several of
these toxins into Aplysia neurones allowed us to reveal a new role for Rac in the
control of exocytosis. ADP-ribosylating enzymes, which specifically act on
monomeric actin (C2 binary toxin from C. botulinum and iota toxin from C.
perfringens), are potential tools to probe the role of actin filaments during
secretion.
PMID- 10783705
TI - [Muscarinic modulation of cardiac activity].
AB - The goal of the present review is to report information concerning cardiac
innervation or more precisely to approach the modulation of cardiac electrical
and mechanical activity by parasympathetic innervation. Acetylcholine (ACh)
release by nerve endings from the vagus nerve hyperpolarizes the membrane,
shortens action potential (AP) duration and has a negative inotropic effect on
cardiac muscle. Toxins are usefull tools in the study of membrane signals. The
Caribbean ciguatoxin (C-CTX-1) has a muscarinic effect on frog atrial fibres. The
toxin evokes the release of ACh from motoneuron nerve terminals innervating this
tissue which allows us to propose a model, similar to the one of the
neuromuscular junction (nmj), to describe the events occurring during the
triggering and release of ACh. Trachynilysin (TLY) is a proteic toxin which
causes an influx of Ca2+ into the cells and releases ACh from nmj synaptic
vesicles. TLY has a muscarinic effect on atrial fibres which is explicated in the
release of neurotransmitter from the nerve endings generated by the TLY-induced
Ca2+ influx. It is known that ACh release from nmj is known to be due to
exocytosis of synaptic vesicles via the activation of a proteic complex blocked
by botulinum toxins. One of these proteins SNAP-25 is the target of type A
botulinum toxin (BoNT/A). The study of hearts isolated from BoNT/A poisoned frogs
show that atrial AP is lengthened and reveals the presence of SNAP-25 in nerve
endings of this tissue. Moreover, the electrical activity of ventricular muscle
is markedly altered; in BoNT/A treated frog, an important outward current
activated by internal Ca2+ develops. ACh released from nerve terminals binds to a
G protein coupled membrane receptor and activates a K+ channel and other
effectors. Five subtypes of muscarinic receptors have been cloned from different
tissue (M1, M2, M3, M4) subtypes have been identified in cardiac tissues
throughout many species. These receptors coupled with different G-proteins
activate different effectors. M1 receptors modulate the cardiac plateau and
therefore the magnitude of the peak contraction. M2 receptors are mainly involved
in the repolarization phase of the AP and modulate the duration of the peak
contraction. The roles of M3 and M4 are not yet clearly defined; however, they
may activate K+ currents. In conclusion, ACh releases from parasympathetic nerve
endings which innervate cardiac cells follows to similar events (Ca2+ influx;
presence of a SNAP-25 protein) to those which produce ACh release from nmj,
stimulates different G proteins coupled muscarinic receptors, and activates
different effectors involved in the modulation of cardiac electrical and
mechanical activity.
PMID- 10783706
TI - [Conus venoms: a source of toxins which interact with membrane- potential
dependent sodium channels].
AB - Marine snails of the genus Conus, as they are carnivorous predators, have a venom
apparatus used to capture their prey. The toxins contained in the venoms of
Conidae, called conotoxins, are of a particular high degree of diversity and
represent powerful tools in the neuroscience field. Indeed, these toxins
specifically bind with a high affinity to receptors and ionic channels.
Therefore, they provide original pharmacological tools which receive increasing
investigation both to identify and study some functions of the nervous systems
and to characterize new types and closely related subtypes of receptors or ionic
channels. The voltage-gated sodium channel, because of its fundamental role in
cell membrane excitability, is the specific target of a large number of animal
and vegetal toxins. Actually, at least seven toxin receptor sites have been
identified on this channel-protein. These toxins, and in particular conotoxins,
are used to precise the role of different types and/or closely related subtypes
of sodium channels in the peripheral and central nervous systems. The focus of
the present review is to summarize our current knowledge of the consequences of
physiological interactions between different conotoxin families and sodium
channels.
PMID- 10783707
TI - [Effect of ciguatoxins on the cardiocirculatory system].
AB - The aim of the present review was to collect the main observations reported until
now concerning the cardio-circulatory effects of polyether toxins, called
ciguatoxins, which are involved in an endemic intoxication named ciguatera found
in tropical and subtropical countries. Ciguatera is caused by the ingestion of
fishes contaminated with the dinoflagellate Gamberdiscus toxicus. Due to both
tropical fish exportation destined for food and tourism, the disease has now
spread out to temperate areas. Several toxins have been isolated and purified
from different fish species living in different geographical areas. They are
classified into three main groups by the nature of certain cycles of their carbon
skeleton. Clinical reports show evidence that ciguatera intoxication affect both
electrocardiograms and blood pressure. In most cases, ciguateric intoxication
mainly evoked bradycardia, hypotension, and the alteration of S-T segment in the
electrocardiogram. Isolated and purified ciguatoxins strongly altered the
morphology of cardiac tissue inducing swelling of the cells and alterations of
cellular organelles. These toxins impair the conduction of cardiac nerves and
increase the opening probability of Na+ channels in intracardiac ganglions.
Depending on the concentration applied, the substances exerted either a fast
positive inotropic effect or a negative inotropic effect on the contraction of
mammalian atrial and ventricular cardiac muscle. These effects were attributed to
a release of noradrenaline and acetylcholine from neural terminals of the
autonomic nervous system present in cardiac tissue. They also exert a slow
delayed inotropic effect on the contraction which has been attributed to a direct
effect of the toxins on tetrodotoxin-sensitive voltage-dependent Na+ channels of
cardiac membranes. Ciguatoxins depolarized the membrane of mammalian atrial and
ventricular preparations and shifted the threshold of sodium current activation
to more negative membrane potentials. In conclusion, the inotropic effects of
ciguatoxins on cardiac tissues mainly depend on the toxin concentration
sensitivity of autonomic nerve terminals, which released noradrenaline and/or
acetylcholine, while the ciguatoxin-induced increase of the sodium influx could
be involved in the cardiac cell swelling which coincides with reports in which
ciguatoxins induced a mannitol-inhibited swelling of the Node of Ranvier.
PMID- 10783708
TI - [The fasciculin-acetylcholinesterase interaction].
AB - Acetylcholinesterase (AChE) terminates the action of the neurotransmitter
acetylcholine at cholinergic synapses in the central and peripheral nervous
systems. Fasciculins, which belong to the family of "three-fingered" snake
toxins, selectively inhibit mammalian AChEs with Ki values in the picomolar
range. In solution, the cationic fasciculin appears to bind to the enzyme's
peripheral anionic site, located near the mouth of the gorge leading to the
active center, to inhibit catalysis either allosterically or by creating an
electrostatic barrier at the gorge entry (or both). Yet the crystal structure of
the fasciculin-mouse AChE complex, which shows that the central loop of
fasciculin fits snugly at the entrance of the gorge, suggests that the mode of
action of fasciculin is steric occlusion of substrate access to the active
center. Mutagenesis of the fasciculin molecule, undertaken to establish a
functional map of the binding surfaces, identified determinants common to those
identified by the structural approach and revealed that only a few of the many
fasciculin residues residing at the complex interface provide the strong contacts
required for high affinity binding and enzyme inhibition. However, it did not
reconcile the disparity between the kinetic and structural data. Finally, the
crystal structure of mouse AChE without bound fasciculin shows a tetrameric
assembly of subunits; within the tetramer, a short loop at the surface of a
subunit associates with the peripheral site of a facing subunit and sterically
occludes the entrance of the active center gorge. The position and
complementarity of the peripheral site-occluding loop mimic the characteristics
of the central loop of fasciculin bound to AChE. This suggests not only that the
peripheral site of AChE is a site for association of heterologous proteins with
interactive surface loops, but also that endogenous peptidic ligands of AChE
sharing structural features with the fasciculin molecule might exist.
PMID- 10783709
TI - [Tetanus and botulinum toxins are zinc metallopeptidases: molecular mechanisms
and inhibition of their neurotoxicity].
AB - The very high toxicity of tetanus neurotoxin (TeNT) and botulinum neurotoxin
(BoNT) are related to their nature of zinc metallopeptidases able to selectively
cleave small proteins involved in neurotransmitters exocytosis. At this time,
there is no efficient and selective therapy towards tetanos and tobulism as well
as protection against a possible spreading of the toxins. We have therefore
investigated the minimum sequences of TeNT and BoNT substrates allowing an
efficient and simple fluorescent dosage of the enzymatic activity to be
developed. Using synaptobrevin (93 amino acids) as substrate of TeNT and several
fragments synthesised by solid phase method, we have shown that the clostridial
neurotoxins behave as allosteric-type enzymes. This is the first example in zinc
metallopeptidases. Based on these results a strategy, including the use of
combinatorial chemistry, was carried out issuing in the design of the first
potent inhibitors of TeNT and BoNT.
PMID- 10783710
TI - [Induction of membrane excitability in Xenopus oocytes].
AB - Immature oocytes from the African toad Xenopus laevis are not known to be
excitable cells, which means that they do not generate an action potential in
response to small depolarizations. However, a regenerative response is produced
if successive depolarizing currents of large magnitude are applied to the oocyte
membrane. This response is characterized by the occurrence of a positive
transmembrane potential that can last for several minutes. The opening of voltage
dependent channels, highly selective for sodium ions, underlies the
depolarization thus obtained. These channels exhibit unconventional
electrophysiological and pharmacological properties, which set them apart from
other types of voltage-dependent sodium channels found in excitable tissues. The
opening of the oocyte sodium channels is a complex process, which includes an
induction phase. During this phase, the channels change from an electrical state
of inexcitability into an excitable voltage-dependent state. The induction
mechanism is modulated by the temperature of the bathing medium, by the
activation of enzymes (namely a phospholipase C and a protein kinase C) and by
the release of calcium ions from intracellular phosphatidyl-inositol
trisphosphate stores. The results summarized in this review point out the
possible role that these sodium channels may play in the physiology of the
oocyte.
PMID- 10783711
TI - [Bacillus thuringiensis: a biotechnology model].
AB - This paper is on the different biotechnological approaches that have been used to
improve Bacillus thuringiensis (Bt) for the control of agricultural insect pests
and have contributed to the successful use of this biological control agent; it
describes how a better knowledge of the high diversity of Bt strains and toxins
genes together with the development of efficient host-vector systems has made it
possible to overcome a number of the problems associated with Bt based insect
control measures. First we present an overview of the biology of Bt and of the
mode of action of its insecticidal toxins. We then describe some of the progress
that has been made in furthering our knowledge of the genetics of Bt and of its
insecticidal toxin genes and in the understanding of their regulation. The paper
then deals with the use of recombinant DNA technology to develop new Bt strains
for more effective pest control or to introduce the genes encoding partial
endotoxins directly into plants to produce insect-resistant trangenic plants.
Several examples describing how biotechnology has been used to increase the
production of insecticidal proteins in Bt or their persistence in the field by
protecting them against UV degradation are presented and discussed. Finally,
based on our knowledge of the mechanism of transposition of the Bt transposon
Tn4430, we describe the construction of a new generation of recombinant strains
of Bt, from which antibiotic resistance genes and other non-Bt DNA sequences were
selectively eliminated, using a new generation of site-specific recombination
vectors. In the future, continuing improvement of first generation products and
research into new sources of resistance is essential to ensure the long-term
control of insect pests. Chimeric toxins could also be produced so as to increase
toxin activity or direct resistance towards a particular type of insect. The
search for new insecticidal toxins, in Bt or other microorganisms, may also
provide new weapons for the fight against insect damage.
PMID- 10783712
TI - Bacterial resistance; an emerging health problem.
PMID- 10783713
TI - Antibiotic resistance: genetic mechanisms and mobility.
AB - Based on the current knowledge, resistance genes seems mainly to originate in the
organisms which produce antibiotics (Davies 1994). We lack considerably in the
understanding of how these genes were transferred to pathogenic bacteria, and due
to the enormous diversity of e.g. the soil flora, it is doubtful that we will
ever obtain more that a faint picture of this. In Gram negative bacteria, more
and more resistance genes are demonstrated to be located in integrons (e.g. beta
lactamase and streptomycin resistance genes in Salmonella Typhimurium DT104
(Sandvang et al. in press)). Integrons seem primarily to act as insertion sites
for resistance genes. The origin of integrons as well as the resistance gene
cassettes that are the other essential element of this system, is largely unknown
(Hall & Collis 1995). Integrons can be located in the chromosome, in transposons,
which have the ability to copy them themselves to other DNA molecules, or on
plasmids. The emergence of resistant bacteria normally happens because of
selection for a resistant clone of bacteria. Several mechanisms, however, exists
by which the resistance genes can be transferred from one bacteria to another.
Conjugation, mediated by plasmids or conjugative transposons, is currently the
most well established of these mechanisms. Still, however, the selection pressure
created by the use of antibiotics determines whether bacteria that have newly
acquired a resistance gene expand to dominate in the population or remains a
blink in history.
PMID- 10783714
TI - Current status of antibiotic resistance in animal production.
AB - It is generally accepted that the more antibiotics we use, the faster bacteria
will develop resistance. Further it has been more or less accepted that once an
antibiotic is withdrawn from the clinic, the resistance genes will eventually
disappear, [table: see text] since they will no more be of any survival value for
the bacterial cell. However, recent research has shown that after a long time
period of exposure to antibiotics, certain bacterial species may adapt to this
environment in such a way that they keep their resistance genes stably also after
the removal of antibiotics. Thus, there is reason to believe that once resistance
has developed it will not even in the long term be eradicated. What then can we
do not to increase further the already high level of antibiotic-resistant
bacteria in animals? We should of course encourage a prudent use of these
valuable drugs. In Sweden antibiotics are not used for growth promoting purposes
and are available only after veterinary prescription on strict indications.
Generally, antimicrobial treatment of animals on individual or on herd basis
should not be considered unless in connection with relevant diagnostics. The
amounts of antibiotics used and the development of resistance in important
pathogens should be closely monitored. Furthermore, resistance monitoring in
certain non-pathogenic intestinal bacteria, which may serve as a reservoir for
resistance genes is probably more important than hitherto anticipated. Once the
usage of or resistance to a certain antibiotic seems to increase in an alarming
way, steps should be taken to limit the usage of the drug in order to prevent
further spread of resistance genes in animals, humans and the environment. Better
methods for detecting and quantifying antibiotic resistance have to be developed.
Screening methods must be standardized and evaluated in order to obtain
comparable and reliable results from different countries. The genetic mechanisms
for development of resistance and spread of resistance genes should be studied in
detail. Research in these areas will lead to new ideas on how to inhibit the
resistance mechanisms. So far, it has been well established that a heavy
antimicrobial drug selective pressure in overcrowded populations of production
animals creates favourable environments both for the emergence and the spread of
antibiotic resistance genes.
PMID- 10783715
TI - Antibiotic resistance in aquaculture.
PMID- 10783716
TI - Antimicrobial resistance in bacteria from pets and horses.
PMID- 10783717
TI - Transfer of antibiotic resistant bacteria from animals to man.
AB - Antibiotic resistance develops in zoonotic bacteria in response to antibiotics
used in food animals. A close association exists between the amounts of
antibiotics used and the levels of resistance observed. The classes of
antibiotics routinely used for treatment of human infections are also used for
animals either for therapy or for growth promotion. Antibiotic resistance in
zoonotic bacteria constitute a public health hazard, primarily through the
increased risk of treatment failures. This paper describes the zoonotic bacteria,
salmonella, campylobacter, yersinia and entero-haemorrhagic E. coli (EHEC).
Infections with these agents do not generally require antibiotic therapy, but in
some cases antibiotics are essential to obtain a successful cure. The levels and
types of resistance observed in zoonotic bacteria in some countries, especially
the increasing levels of fluoroquinolone resistance in salmonella and
campylobacter, gives cause for concern. The principles of controlling resistance
development involve infection control at herd level and prudent use of
antibiotics.
PMID- 10783718
TI - Indirect transfer of antibiotic resistance genes to man.
PMID- 10783719
TI - Public health aspects of antibiotic resistance monitoring in the USA.
AB - Treatment of food-producing animals with antimicrobial agents that are important
in human therapy may present a public health risk by the transfer of resistant
zoonotic pathogens or resistant genes from animals to humans via consumption of
contaminated food. Resistant bacteria can diminish the effectiveness of
antibiotics and demand the use of more expensive or less safe alternatives. In
1996, the U. S. Food and Drug Administration (FDA), the Centers for Disease
Control and Prevention (CDC), and the Department of Agriculture (USDA)
established the National Antimicrobial Resistance Monitoring Program to
prospectively monitor changes in antimicrobial susceptibilities of zoonotic
enteric pathogens from human and animal clinical specimens, from healthy farm
animals, and from carcasses of food-producing animals at slaughter plants. Data
resulting from the monitoring program will be used to redirect antimicrobial drug
use, primarily through educational initiatives directed at health practitioners,
in order to diminish the development and spread of resistance. Veterinary testing
is conducted at USDA's Agricultural Research Service and CDC's Foodborne Disease
Laboratory is testing human isolates under contract to FDA. Both the CDC and USDA
laboratories are using a semi-automated system (Sensititre, Accumed, Westlake,
Ohio) for testing susceptibilities of the isolates to 17 antimicrobial agents on
a minimum inhibitory concentration plate. Comparable methods for isolate handling
are used in both laboratories. This paper describes the development,
implementation, and objectives of the National Antimicrobial Resistance
Monitoring Program, presents initial data generated by the program, and discusses
future plans.
PMID- 10783720
TI - Design of a system for monitoring antimicrobial resistance in pathogenic,
zoonotic and indicator bacteria from food animals.
AB - DANMAP is a Danish programme for integrated monitoring of and research on
antimicrobial resistance in bacteria from food animals, food and humans. The
paper describes how bacteria from broilers, pigs, and cattle are collected, as
well as the procedures for data handling and presentation of results. The
bacteria from animals include certain pathogens, selected so that they are
representative for submissions to Danish diagnostic laboratories, as well as
zoonotic bacteria (Campylobacter, Salmonella and Yersinia) and indicator bacteria
(E. coli, E. faecium and E. faecalis), from samples collected at abattoirs. The
latter samples are selected so that they are representative of the respective
animal populations. Therefore, the apparent prevalence of antimicrobial
resistance in the populations may be calculated. The isolates are identified to
species level and the results of susceptibility testing are stored as continuous
variables. All isolates are maintained in a strain collection so that they are
available for subsequent research projects. The data handling facilities makes it
possible to present results as percent resistant isolates or as the apparent
prevalence of resistance in the population, or alternatively as graphical
distributions of mm inhibition zones or MIC values. Computer routines have been
established that make it possible to detect specific phenotypic expressions of
resistance that may be of particular interest.
PMID- 10783721
TI - Antibiotics as growth promoters.
PMID- 10783722
TI - The animal health and animal welfare situation in the European Union.
PMID- 10783723
TI - Summary review of the chronology of the major measures in relation to bovine
spongiform encephalopathy (BSE) in the United Kingdom and the European Union.
PMID- 10783724
TI - Animal health conditions for trade within and import into the European Union of
live animals and animal products.
PMID- 10783725
TI - Role of the industry in preventing introduction of animal disease in Denmark.
PMID- 10783726
TI - The situation from Iceland's point of view.
PMID- 10783727
TI - The situation from Norway's point of view ecological and health consequences of
spreading of pathogenes and genes through an increasing trade in foods.
PMID- 10783728
TI - Veterinary service and animal health situation in Latvia (1990-1996).
PMID- 10783730
TI - Programmes to control or eradicate Salmonella in animal production in Denmark.
AB - The number of diagnosed cases of salmonella infections in humans has been
increasing during the latest 10 years, for the last 5 years mainly because of an
increase in infections with Salmonella Enteritidis. As far as Danish produced
animal products is concerned, it is assumed that the most important sources of
human salmonella infections are, in order of priority: eggs, poultry meat and
pork. In Denmark there are at the moment public and voluntary salmonella pre
harvest reduction programmes in the production of pigs, broilers and eggs. The
programme in the pig production is a control programme, that means that the aim
is to maintain a generally low level of salmonella in pig herds. At the same time
the goal of a low level of salmonella contamination of pork is also pursued
through general and specific hygiene measures in the slaughterhouses. The
programmes in the poultry production are limited to broilers and hens eggs. They
are, at least in theory, eradication programmes where the aim is total freedom
from salmonella. According to the rules of Council Directive 92/117/EEC, flocks
of hens producing eggs for hatching must be free from Salmonella Enteritidis and
Typhimurium, whereas according to the Danish national requirements (Veterinary
Service Orders to come into effect shortly), these two salmonella serotypes must
be eradicated from flocks of hens producing eggs for sale to consumers and all
salmonella serotypes must be eradicated from flocks of hens producing eggs for
hatching.
PMID- 10783729
TI - A common Salmonella control programme in Finland, Norway and Sweden.
PMID- 10783731
TI - Risk analysis, a tool for improved decision making.
PMID- 10783732
TI - [Metallothionein].
PMID- 10783733
TI - A new idea in the field of ACE inhibition: continuous drug administration
(perchronotherapy).
PMID- 10783734
TI - Expansion of haematopoietic stem cells in vitro: a challenge to stem cell
biologists.
AB - Expansion of haematopoietic stem cells from various sources has gained importance
so as to provide a clinically potential graft, which shows ideal growth kinetics,
resulting in reduction of the period of neutropenia and thrombocytopenia in any
autologous or allogenic transplant setting. Expansion also facilitates
transduction of genes for gene therapy. This review examines the various means
employed to achieve the expansion of stem cells, and the criteria used to score
the extent of expansion based on how stem cells are identified. It tries to
analyse the ideal manner in which expansion should be carried out, with emphasis
that expansion should not be at the expense of loss of stemness. It also attempts
to judge the roles played by the stromal elements and cytokines, which are both
part of the complex microenvironment, which in vivo has a strict regulation on
haematopoiesis.
PMID- 10783735
TI - Light sensitivity of the photoperiodic response system in higher vertebrates:
wavelength and intensity effects.
AB - Most species use daily light in one way or the other in regulation of their short
and/or long term activities. Light is perceived by pigment(s) present in the
retinal (RP) and/or extra-retinal photoreceptors (ERPs). ERPs may be located at
various sites in the body but in non-mammalian vertebrates they are found
predominantly in the pineal body and hypothalamic region of the brain, Light
radiations directly penetrate brain tissues to reach and stimulate the
hypothalamic (deep-brain) photoreceptors. How does light information finally
reach to the clock is not fully understood in many vertebrate groups? In mammals,
however, the light information from the retina to the clock (the hypothalamic
suprachiasmatic nuclei, SCN) is relayed through the retino-hypothalamic tract
(RHT) which originates from the retinal ganglion cells, and through the geniculo
hypothalamic tract (GHT) which originates from the photically responsive cells of
a portion of the lateral geniculate nucleus (LGN), called the intergeniculate
leaflet (IGL). A response to light (the photoperiodic response) is the result of
the interpretation of light information by the photoperiodic system. Apart from
the duration, the animals use the gradual shifts in the intensity and wavelength
of daily light to regulate their photoperiodic clock system. The wavelengths to
which photoreceptors are maximally sensitive or the wavelengths which have
greater access to the photoreceptors can induce a maximal response. There can
also be differential effects of wavelength and intensity of light on circadian
process(es) involved in the entrainment and induction of the photoperiodic clock.
This may have some adaptive implications. Entrainment to daily light-dark (LD)
cycle may be achieved at dawn or dusk, depending whether the animal is day- or
night-active, when there is relatively low intensity of light. By contrast,
photoperiodic induction in many species occurs during long days of spring and
summer when plenty of daylight at higher intensity is available later in the day.
PMID- 10783736
TI - Effect of thiocyanate induced hypothyroidism on 5'deiodinase activity and T3
receptors in developing rat brain.
AB - Experiments were performed in weaning rats to understand the influence of
thiocyanate, an hydrolytic product of glucosinolates present in foods, on the
generation of T3 in situ by type II 5'deiodinase and the binding of 125I T3 to
specific nuclear receptors in developing brain. Feeding of thiocyanate through
gestation and lactation resulted in an increase in type II 5'deiodinase activity
in cerebrum, cerebellum and brainstem of the 21 day old pups compared to
controls. Hypothyroidism induced by thiocyanate further resulted in augmentation
of the maximum binding capacity of receptors in the cerebrum of the weaning pups.
Affinity constants for binding of 125I T3 were however, unaltered. Increase in
type II 5'deiodinase activity and the number of binding sites point to an
adaptive increase in response to thiocyanate induced hypothyroidism to maintain
the cellular T3 levels within a narrow limit.
PMID- 10783737
TI - Effect of phenobarbitone administration to pregnant rats on anxiety in
offsprings.
AB - Adults Charles-Foster rats were prenatally treated to phenobarbitone (10 mg/kg,
i.p.) from day 13 to 21 of gestation, this being the critical period of neural
development. Pregnant control rats were similarly treated with equal volume of
vehicle. Adult rat offsprings at 8-9 weeks of age were subjected to open-field
exploratory behaviour, elevated plus-maze and elevated zero-maze tests. The rat
offsprings displayed significantly increased ambulation and rearings in an open
field arena when compared to control offsprings whereas self-grooming and faecal
droppings remain unchanged. On elevated plus-maze test these prenatally treated
rat offsprings spent significantly less time on open arms and more time and more
number of entries in enclosed arms as compared to controls. Prenatally exposed
rats also showed significant less time on open arms, less number of head dips and
stretched attend postures on elevated zero-maze test indicating increased
anxiogenic behavioural pattern in these animals. The results suggest that
prenatal exposure to phenobarbitone leaves a lasting effect on the anxiety state
of the offsprings.
PMID- 10783738
TI - Perturbations in phosphoinositide metabolism and protein kinase C activity in
mouse liver following whole body irradiation.
AB - The involvement of the signal transduction pathway in mouse liver following whole
body irradition was investigated. Mice were exposed to 60Co gamma rays (3 Gy) and
sacrificed after different time intervals. Various elements of phosphatidyl
inositol signal transduction pathway were investigated. Alterations could be seen
as early as 15 min of irradiation. These changes are reflected in elevation in
DAG levels and increased activation of PKC, an enzyme which is involved in
tumorigenesis. The chronological appearance of various transducers following
whole body irradiation is of significance since these early effects may set the
stage for radiation-induced tumorigenesis and hence may be used to manipulate
tumor response to radiotherapy.
PMID- 10783739
TI - Effect of aqueous extract of Ipomoea carnea leaf on isolated frog and mouse
heart.
AB - Ipomoea carnea fam. Convolvulaceae is a poisonous plant and its toxicity is
supposed to be due to the cardiac and respiratory failure. The present paper
describes the cardiac effect of aqueous extract of the fresh leaves of I. carnea
using mouse and frog heart. The aqueous extract produced an initial blockade of
isolated frog heart for 5-10 sec followed by dose dependent increase in both
amplitude and rate that lasts up to 2 min. Atropine (1 microgram/ml) blocked the
initial depressant phase and potentiated the stimulant effect of the aqueous
extract. The dose dependent increase in cardiac contractility of aqueous extract
was not altered by propranolol or calcium channel blockers like nifedipine or
diltiazem. The decrease in sodium chloride concentration or increase in potassium
chloride concentration or calcium chloride concentration in physiological salt
solution inhibited the responses to aqueous extract while an increase in sodium
chloride concentration or decrease in potassium chloride or calcium chloride
concentration in physiological salt solution potentiated the responses to the
aqueous extract of I. carnea. It may be suggested from the data that aqueous
extract of I. carnea produces positive inotropic effect on isolate frog heart
possibly by sodium extrusion or release of the intracellular calcium.
PMID- 10783740
TI - Sperm-mediated gene transfer into oocytes of the golden hamster: assessment of
sperm function.
AB - The possibility of sperm as a vehicle to deliver foreign DNA to oocytes was
tested in hamsters. Epididymal spermatozoa, incubated with linearized plasmid DNA
encoding ovine growth hormone (pCMXoGH), showed a spontaneous tendency to
interact with DNA. Kinetics of sperm uptake of DNA was determined by using [32P]
labeled DNA. Spermatozoa took up the added DNA by 15-30 min and the uptake was
inhibited by human seminal fluid in a dose dependent manner. Addition of DNA did
not affect the functional competence of spermatozoa, in terms of their ability to
undergo capacitation and acrosome reaction (34.5% +/- 2.2 vs 35% +/- 1.5). The
fertilizing ability of DNA treated-spermatozoa from hamsters and humans was
assessed by zona-free hamster egg penetration assay. Number of sperm penetrated
per oocyte were 23 +/- 4.5 and 1.4 +/- 1.3 for hamster and human spermatozoa,
respectively. Penetrated oocytes harbored sperm-treated DNA both with hamster
(30.2 cpm/oocyte) and human (19.2 cpm/oocyte) spermatozoa. These results show
that the hamster and human spermatozoa have a strong tendency to interact with
exogenous (foreign) DNA and are able to transfer DNA to oocytes. Sperm may be
used as a vector for DNA transfer and this approach has potential in the
production of transgenic animals.
PMID- 10783741
TI - Subpopulations of physiological and ovarian follicular fluid peptide induced
apoptotic cells.
AB - Ovarian follicular fluid peptide (OFFP) purified from sheep ovaries enhances
apoptotic changes in ovarian granulosa cells of mice. To get an insight into the
cell subpopulations responding to OFFP, the heterogeneity of granulosa cells was
resolved. Subpopulations of granulosa cells were obtained from ovaries of
immature mice treated with PMSG alone and autopsied 48 hr (control) and 72 hr
after injection (atretic) and from animals injected OFFP 24 hr after PMSG
injection and autopsied 24 hr later (OFFP treated) by separation on discontinuous
Percoll gradient. Four fractions were collected and studied for their relative
distributions and percent apoptotic cells measured by acridine orange staining.
FSH binding to granulosa cell (sedimenting as a major) fraction was studied by
radio receptor assay. There is a difference in densities in subpopulations of
apoptotic cells induced by OFFP and those generated during the physiological
process of atresia. This difference may be a reflection of different granulosa
cell subpopulations involved in peptide response or differences in phases as the
cells transit from normal to apoptotic phenotype. FSH binding to granulosa cells
from OFFP treated animals was significantly less than those from control and
atretic group.
PMID- 10783742
TI - Neem (Azadirachta indica) extract as an antibacterial agent against fish
pathogenic bacteria.
AB - Aquaneem, an emulsified product prepared from the neem (A. indica) kernel was
tested against four pathogenic bacteria of fish (i.e. Aeromonas hydrophila,
Pseudomonas fluorescens, Escherichia coli and Myxobacteria spp.) to test its
efficacy as an antibacterial agent. Growth inhibitory property of the product at
10, 15 and 20 ppm has been noticed and recorded. The percentage reduction of
bacterial cell population was noted to be maximum on 9th day at 20 ppm
concentration (i.e. 70.14%, 74.15% and 61.75% for A. hydrophila, P. fluorescens
and E. coli respectively) with the only exception of myxobacteria which showed
maximum reduction percentage (63.90%) on 15th day. Among all the bacteria tested
A. hydrophila, P. fluorescens and Myxobacteria spp. exhibited maximum sensitivity
to Aquaneem in terms of percentage reduction of bacterial cell population in
comparison to E. coli.
PMID- 10783743
TI - Induction of Salmonella enterotoxin (stn) gene expression by epithelial cells
(IEC-6).
AB - Prevalence of Salmonella enterotoxin (stn) gene among Salmonella enterica and S.
bongori was investigated by polymerase chain reaction (PCR) and gene probe and
its status of phenotypic expression was examined on chinese hamster ovary cells
by cultivating the strains with conventional method for enterotoxin production
and by cultivating the organisms in contact with intestinal epithelial cells of
rats (IEC-6). All the 19 strains and serovars of S. enterica such as Typhimurium,
Enteritidis, Newport, Weltevreden, Indiana, Gallinarum and Kentucky were found to
carry stn gene as examined by PCR and gene probe but only a limited number of
strains (13 out of 19) expressed phenotypically the enterotoxin when cultured by
conventional method. Cultivation of organisms in contact with epithelial cells
induced expression of stn gene phenotypically in all the 19 strains. In contrast
to S. enterica, strains of S. bongori were found neither genotypically (stn) nor
phenotypically (Stn) positive.
PMID- 10783744
TI - Assessment of protein quality of infant milk food formula supplemented with
lactulose.
AB - To examine the protein quality of infant food formula supplemented with lactulose
(bifidogenic factor), groups of 21 day male weanling rats were fed diet
containing lactulose at 0.5% for 4 weeks. The gain in body weight of rats fed
lactulose supplemented diet were similar to that of rats fed lactulose free and
skim milk powder fed diet as controls. No difference in overall acceptability
pattern was also observed in studies conducted with human subjects for
organoleptic evaluation. The results suggest that supplementation of lactulose in
infant food formula does not affect either the protein quality as indicated by
protein efficiency ratio in rats as compared to control formulae or overall
acceptability by human subjects.
PMID- 10783745
TI - Passive immunization of piglets against enterotoxigenic colibacillosis by
vaccinating dams with K88ac pili bearing bacterins.
AB - Day-old-piglets were passively immunized by vaccinating the pregnant sows with
K88ac enterotoxigenic Escherichia coli (ETEC) vaccine. High level of ETEC
specific antibodies was excreted in colostrum (3733.33 +/- 1152.13) and
maintained a detectable level (100.00 +/- 0.00) up to 21 day post partum (DPP).
The IgG was the predominant immunoglobulin followed by IgA and IgM. Piglets born
of vaccinated dam (group A) and unvaccinated dam (group B) were challenged in 7
day of age. Clinical and faecal scores were significantly (P < 0.01) low in group
A than that of group B. Piglets of group A developed mild diarrhoea (33.33%),
while all the control piglets developed profuse diarrhoea and 3 of these died
before 14 day of challenge infection.
PMID- 10783746
TI - Effect of Ocimum sanctum fixed oil on vascular permeability and leucocytes
migration.
AB - Ocimum sanctum fixed oil significantly inhibited the rise in protein
concentration and dye leakage in peritoneal fluid in experimentally induced
peritoneal inflammation in mice. In carrageenan-induced pleurisy in rats, the
fixed oil showed significant inhibition of leucocytes migration in the pleural
exudate. The results suggest that the fixed oil can inhibit enhancement of the
vascular/capillary permability and leucocyte migration following inflammatory
stimulus.
PMID- 10783747
TI - Studies on cytochrome oxidase in carbon tetrachloride treated rats.
AB - Cytochrome c oxidase was purified from control and CCl4 treated rats and its
kinetic properties were studied. The activity of the enzyme was inhibited by 51%
in CCl4 (4 g per kg body weight for 24 hr) treated rats. Studies on the kinetic
properties showed that the K(m) of the enzyme increased by 60% while Vmax
decreased by 44% in CCl4 treated rats compared to controls. The content of
cytochrome aa3 was decreased by 34% while cytochrome b and c were not affected by
CCl4 treatment. Phosphatidylcholine, phosphatidylethanolamine and cardiolipin
were decreased significantly by 40%, 49% and 60% respectively in CCl4 treated
rats. A decrease in the cytochrome aa3 content and a change in the lipid
environment of the membrane are probably responsible for a decreased rate of
electron transfer from cytochrome c to oxygen.
PMID- 10783748
TI - Estimation of different degrees of provocation by DEC (diethyl carbamazine
citrate) medication in bancroftian filariasis in Vellore, Tamilnadu.
AB - DEC in general has the power to bringout the filarial worms into the peripheral
blood when administered. The provocative effect was observed in 86.8% of the mf
positive cases. Optimum provocative effect was noticed in the age group above 12
years and there was no influence on sex. The maximum effect of provocation was
seen at 60 min after the administration 2 mg/kg body weight DEC. The mf rate was
high in the blood collected after the administration of DEC during day time, than
that during night.
PMID- 10783749
TI - Effect of entomopathogenic fungus, Beauveria bassiana on larvae of three species
of mosquitoes.
AB - Beauveria bassiana, an entomopathogenic fungus, was evaluated for its potential
against second and third instar larvae of Culex quinquefasciatus, Anopheles
stephensi and Aedes aegypti. Conidiospores of this fungus were effective in
causing infection leading to mortality of different larval instars. Larvae of Cx.
quinquefasciatus were more susceptible to infection than An. stephensi and the
second instar larvae of these two species were more susceptible than third instar
larvae. Larvae of Ae. aegypti were resistant to infection by B. bassiana.
PMID- 10783750
TI - Turritella attenuata (Kasinathan): as biological indicator of marine pollution--a
trace metal analytical study.
AB - A study to monitor marine pollution with reference to trace elements (Fe, Zn, Mn
and Cu) on T. attenuata, commonly called as screw shell over a period of one year
on the whole body and various organs, viz. digestive diverticula, foot, mantle
and ovary was conducted from the sandy beach of Porto Novo Coast (Lat 11 degrees
29' N Long: 79 degrees 46' E) of Peninsular India using Atomic Absorption
Spectrophotometer (AAS). Higher concentration of all the four trace metals
analysed were recorded in the digestive diverticula, whereas lower concentration
of zinc and manganese were recorded in the ovary during the monsoon period. The
higher level of trace metal concentration in the monsoon period may be due to the
presence of these pollutants in large amounts in water. The accumulation of
selected trace metals varies in different seasons according to the extent of
pollution load in the marine environment.
PMID- 10783751
TI - Factors influencing adherence of Candida spp. to host tissues and plastic
surfaces.
AB - Attachment of Candida spp. to host tissues and plastic surfaces is the first and
a crucial step that initiates colonization by yeast cells and subsequent
development of disseminated fungal infection. These infections are associated
with high degree of morbidity, mortality and extra cost. Modern trends have
focused not only on how best to treat but also on how to prevent Candida
infections. To achieve this goal, the factors that influence the adherence of
Candida spp. to biological and non biological surfaces have been studied. C.
albicans adheres at a degree higher than that of the other Candida spp. and C.
tropicalis adheres to a lesser extent. This may reflect the higher pathogenicity
of C. albicans compared to the other Candida spp. Germinated C. albicans cells
adhere to host tissue more readily than do yeast-phase. Sugars play an important
role in the adherence of Candida spp. Overall, galactose was found to promote the
adherence of Candida spp. to host tissues and plastic surfaces more than any
other mono or disaccharide. Amino sugars on the other hand inhibit the adherence
of the yeast cells. Divalent ions such as Ca2+ and Mg2+ promote the adherence of
Candida spp. more than monovalent ions. Candida spp. express on their surface
receptors, which interact with a wide variety of host proteins including
fibrinogen, fibronectin, lamanin, and type I and IV collagen thus binding Candida
spp. To glycoproteinaceous conditioning film at the blood-polymer interface.
Coaggregation of Candida spp. with other bacteria promotes colonization of yeast
cells to oral biofilm, host tissues, and to surfaces of the indwelling vascular
catheters. These factors form the basis for the interference with the adherence
of Candida spp.
PMID- 10783752
TI - Interaction between N-methyl-D-aspartate receptor antagonists and imipramine in
shock-induced depression.
AB - In the past few years, literature has accumulated describing manifestation of
seizures following administration of certain antidepressants. Such reports are of
particular importance because depression is a frequent psychiatric problem
associated with epilepsy. Therefore, in the view of the fact that NMDA receptor
antagonists have been reported to reduce behavioural deficits and have been shown
to be anticonvulsant, it was considered imperative to study their antidepressant
effect using shock-induced depression model in mice. Presentation of inescapable
foot shock significantly reduced ambulation and rearing in the open field arena
and increased immobility duration in the FST. Pretreatment with imipramine, MK
801 and ketamine significantly prevented the effect of shock. Also, the
combination of imipramine with either of the NMDA antagonists antagonised the
effect of shock. Haloperidol, prazosin and ketanserin pretreatment modified the
effect of these agents. These findings suggest an antidepressant effect of the
NMDA receptor antagonists, and a complexity of neurotransmitter mechanisms, which
are responsible for the occurrence of behavioural effects in shock-induced
depression model.
PMID- 10783753
TI - Immunosuppressive activity in buffalo placenta.
AB - Immunosuppressive activity in buffalo placenta was evaluated by measuring
proliferation of lymphocytes in presence of phytohaemagglutinin (PHA) alone or
PHA plus placental proteins. The immunosuppressive activity was dose-dependent
over the protein concentration range of 10-50 micrograms/ml. Proteins from both
cotyledon and non-cotyledon portions of placenta exhibited immunosuppressive
activity. Fractions obtained with 0-40, 40-60 and 60-80% saturated ammonium
sulphate exhibited 70, 73 and 75% suppression, respectively. PBS-soluble
placental proteins were resolved on G-100 column into three peaks that exhibited
69 (peak 1), 55 (peak 2) and 73% (peak 3) suppression. Exogenously added
interleukin-1 (IL-1) failed to reverse the suppression caused by buffalo
placental proteins.
PMID- 10783754
TI - Effect of flavone in a canine model of myocardial stunning.
AB - Putative cardioprotective action of flavone (10, 20 and 30 mg/kg) was
investigated in a canine model of regional ischemia (20 min) followed by 60 min
of reperfusion. In animals pretreated with vehicle, myocardial stunning was
evidenced by significant changes in hemodynamic parameters (depressed mean
arterial pressure, LV peak (+) dP/dt, LV peak (-) dP/dt and elevated LV end
diastolic pressure) and biochemical parameters (decreased myocardial ATP and rise
in plasma malondialdehyde or MDA; a marker of free radical-induced injury). A
reduction in plasma MDA was noted with 20 and 30 mg/kg flavone, although
attenuation of myocardial dysfunction was evident with all the three doses. The
results suggest that besides a significant dose-dependent antioxidant effect,
flavone may also have some cardioprotective actions per se, which needs to be
further investigated.
PMID- 10783755
TI - Effects of intranasal challenge with group A beta haemolytic streptococcus M type
49 in Swiss albino mice.
AB - Mice are susceptible to natural infections with streptococci and therefore can
serve as suitable animal models to study experimental streptococcal infections.
In an earlier study, we had shown the development of pharyngeal colonization,
antibody response and histopathological changes in the heart following intranasal
(IN) challenge with a rheumatogenic serotype of group A beta haemolytic
streptococcus, the M type 18. To determine if nonpharyngitis associated serotypes
can also elicit similar responses, 30 Swiss albino mice were challenged
intranasally with 2 x 10(7) colony forming units of a skin associated serotype of
group A beta haemolytic streptococcus, the M type 49. Pharyngeal colonization
varied from 64% (n = 30) in the first week to 69% (n = 16) during the fourth week
after IN challenge. Eleven (36.7%) of the 30 animals studied showed antibody
response to DNase B (ADNB) with peak titers varying from 150 to 1200 units. Wide
variations were seen in ADNB titers in individual mice. Histopathological
evidence for cardiac lesions were seen in three animals. The changes were mild
and varied from mild to chronic endocardial inflammation to calcification. The
study shows that Swiss albino mice are also susceptible to IN challenge with skin
associated strains of GABHS and therefore can serve as useful models to study the
effects of experimental infection with diverse serotypes of GABHS.
PMID- 10783756
TI - Apoptosis in bovine herpesvirus-1 infected bovine peripheral blood mononuclear
cells.
AB - Apoptosis is a process whereby cells die in a controlled manner in response to
various stimuli like cytotoxins, viral antigens and normal physiological signals
during differentiation and development. Virus induced immunosuppression has been
reported for various viral diseases including Bovine Herpesvirus-1 (BHV-1). In
the present study, BHV-1 was found to cause apoptosis in ConA stimulated bovine
peripheral blood mononuclear cells (PBMCs). Apoptotic index quantified by
fluorescent dyes revealed a significant (P < 0.001) increase in percent apoptotic
cells at 2, 24 and 48 hr post infection as compared to their respective non
infected controls. Apoptosis specific internucleosomal laddering in DNA from BHV
1 infected PBMCs was seen in agarose gel electrophoresis. No DNA fragmentation
was observed in control non-infected PBMCs.
PMID- 10783757
TI - Effect of bracken (Pteridium a quilinum) and dryopteris (Dryopteris juxtaposita)
fern toxicity in laboratory rabbits.
AB - Experimental studies with Bracken and Dryopteris ferns @ 25% concentrate ration
mixture were conducted in rabbits. Fern fed rabbits showed progressive anaemia,
leukopaenia, lymphopaenia and relative heterophilia. Significant elevations in
serum enzymes like serum glutamate oxaloactate transminase (SGOT), serum
glutamate pyruvate transminase (SGPT), alkaline phosphatase (ALP), urea and
creatinine levels were seen. Histopathologically, rabbits showed mild to moderate
vascular changes in most of visceral organs, vacuolar degenerative changes in
hepatocytes, hypersecretory activity in intestine, presence of casts in renal
tubules and degenerative changes in renal tubular lining epithelial cells.
Dryopteris fed rabbits showed somewhat more severe degenerative and vascular
changes in different intervals. A low level of toxic principle ptaquiloside was
detected in Bracken and Dryopteris ferns by thin layer chromatography (TLC) and
high-pressure liquid chromatography (HPLC) methods.
PMID- 10783758
TI - Growth response of African catfish, Clarias gariepinus (Burchell) to varied
protein and lipid levels.
AB - To study the growth response of African catfish (Clarias gariepinus) to the diets
containing two protein (30 and 35%) and two lipid levels (12 and 18%) in a closed
recirculatory system for 60 days, fish were fed to satiation twice daily. The
experiment was carried out in triplicate groups. Fortnightly sampling of fish and
water samples was carried out. The best result in terms of growth was obtained
with the diet containing 34.62% protein and 12.12% lipid. The protein to lipid
ratio was 18.57 in the diet that gave best percentage weight gain. However best
survival, food conversion ratio and protein efficiency ratio were recorded in the
diet containing 29.86% protein and 18.08% lipid.
PMID- 10783759
TI - Evidence for integration of IS1 and IS10 in recombinant plasmid containing
rearrangement hot-spot(rhs) common-shared block(CSB) in Escherichia coli K-12.
AB - The integration of IS1 and IS10 was reported in the recombinant plasmid
containing the 3070 bp rearrangement hotspot(rhs) common-shared block(CSB) in
Escherichia coli K-12. The integration of IS1 was found to be in rhs(CSB)
portion, whereas the integration of IS10 was found to be in both rhs(CSB) and
vector portions. The bacterial cells containing the recombinant plasmid grew very
slowly. But the integration of IS1 or IS10 in rhs(CSB) portion made the host grow
rapidly and overgrew the slow-growing population inheriting the recombinant
plasmids without IS-sequences. The sites of integration of IS1 and IS10 were
different as was judged from restriction endonuclease mapping. These are rare
examples of interchromosomal mobilisation of IS1 and IS10 from host chromosome
into plasmid.
PMID- 10783760
TI - Hepatoprotective activity of ellagic acid against carbon tetrachloride induced
hepatotoxicity in rats.
AB - Administration of CCl4 to normal rats and consequent oral feeding with ellagic
acid (50 mg/kg) provided a significant protection against the biochemical
alterations in serum and liver produced by CCl4. In vitro experiments showed that
liver microsomes from animals treated with ellagic acid and CCl4, decreased lipid
peroxidation compared to microsome prepared from rats exposed to CCl4 alone.
PMID- 10783761
TI - Coordinate production of cephamycin c and clavulanic acid by Streptomyces
clavuligerus.
AB - Production of cephamycin c and clavulanic acid by Streptomyces clavuligerus was
investigated using different media in shake flask condition. Highest cell growth
(3.8 g/L) was observed in glycerol, sucrose, proline and glutamic acid (GSPG)
medium. Although, GSPG medium supported maximum growth, it was least effective
for the synthesis of both cephamycin and clavulanic acid. Yield of cephamycin and
clavulanic acid was maximum in dextrin and K medium, respectively. High and low
level of constituents of dextrin medium, affected production of both cephamycin
and clavulanic acid. Biosynthesis of clavulanic acid was associated with
production of cephamycin c.
PMID- 10783762
TI - Monoclonal antibody based dot-enzyme linked immunosorbent assay (Dot-ELISA) and
agar gel precipitation test (AGPT) for identification of Newcastle disease virus
(NDV).
AB - Two mouse monoclonal antibodies (MAbs), viz. 2B7 and 2 D10 raised against
haemagglutinin-neuraminidase glycoprotein of Newcastle disease virus (NDV) were
used to identify several other field isolates and vaccine strains of NDV. These
MAbs reacted specifically with all the NDV strains/isolates in Dot-ELISA whereas,
only MAb 2D10 reacted with all the NDV strains/isolates in agar gel precipitation
test. These two tests employing the MAbs were standardised for rapid diagnosis
and identification of NDV.
PMID- 10783763
TI - Gamma-interferon bioassay for detection of bovine tuberculosis in cattle:
kinetics of production and dose response in whole blood culture.
AB - Stimulation with Mycobacterium bovis PPD sensitised lymphocytes (whole blood or
peripheral blood lymphocytes) results in release of gamma-interferon that can be
detected by simple bioassay. The optimum concentration of bovine PPD was 20
micrograms ml and the optimum incubation period was 24 hr for maximum production
of gamma-interferon in whole blood culture (128 units/ml) and peripheral blood
culture (64 units/ml).
PMID- 10783764
TI - Long-term feeding effect of thermally oxidised oils on antioxidant enzymes in
rats.
AB - Long term feeding effect of thermally oxidised oils on activities of hepatic
antioxidant enzymes viz. catalase, glutathione peroxidase (GPX), glutathione-S
transferase (GST) and superoxide dismutase (SOD) at 5 and 20% level for 20 weeks
was studied in laboratory rats. Activity of catalase increased in heated and
fried oil fed group of rats, whereas activities of GPX, GST and SOD decreased in
both heated and fried oil groups. Increase or decrease in activities of these
enzymes may be related to several factors like heating and frying conditions,
nature of fat, extent of peroxidation, presence of antioxidants, duration of
feeding, beside other factors.
PMID- 10783765
TI - A non-radioactive method for mapping restriction fragment length polymorphic
genetic markers in Anopheles gambiae.
AB - A non-radioactive method for in situ hybridisation of Restriction Fragment Length
Polymorphic (RFLP) markers to the polytene chromosome of Anopheles gambiae, the
important malaria vector, which yielded good readable quality of chromosomal
bands is reported. The methodology adopted was a Biotin-Streptavidin-Alkaline
Phosphatase system which yielded fluorescent signals when stained with dyes such
as Nitro Blue Tetrazolium and Bromo Chloro Indolyl Phosphate.
PMID- 10783766
TI - Twin reversed arterial perfusion syndrome.
AB - Twin reversed arterial perfusion (TRAP) syndrome is a rare but severe
complication of monozygotic monochorionic twin pregnancies. The outcome is
invariably fatal for the abnormal twins and for 50-75% of the normal co-twins.
The prenatal diagnosis of the TRAP always has to be presumed in a multiple
pregnancy within which a twin pair grows whenever cardiac activity can not be
proved echographically. We present discuss--based upon literature research-
pathogenic mechanisms, pathologic-anatomic, echographic diagnosis and management
of these high-risk pregnancies.
PMID- 10783767
TI - Magnetic resonance imaging of cerebral central sulci: a study of monozygotic
twins.
AB - The cerebral central sulci, seat of the sensorimotor cortex, vary anatomically in
form, length and depth among individuals and present a left/right asymmetry. The
purpose of this work was to measure central sulcus's lengths, at the surface and
in-depth, in each hemisphere of monozygotic twins in order to evaluate the
influence of environmental factors on the morphometry and asymmetry of this
structure. A measurement technique on MR images of the brains using 3 D software
was developed. Two operators applied this technique to measure central sulcus
lengths at the surface of the brain and in-depth in each hemisphere. Besides the
fact that the technique developed gave high Intraclass Correlation Coefficients
(ICC) for the surface lengths (mean value 0.94), and slightly less high for the
in-depth length (mean value 0.87), we found a weak (from 0.57 to 0.73 for raw
data) but significant ICC between homologous sulci in pairs of twins. In
addition, the ICC for asymmetry indices were not significant. Hence, if central
sulcus morphometry is in part genetically influenced, these results show that
nongenetic factors are nonetheless important in their development.
PMID- 10783768
TI - A comparative study of twinning and triplet rates in 17 countries, 1972-1996.
AB - Secular changes in twinning and triplet rates were analyzed using vital
statistics in Austria, the Czech Republic, the Slovak Republic, England and
Wales, Germany, the Netherlands, Switzerland, Denmark, Finland, Norway, Sweden,
Canada, Australia, Hong Kong, Israel, Japan, and Singapore during the period from
1972 to 1996. Among those 17 countries, the twinning and triplet rates in the
Czech Republic and in the Slovak Republic remained constant from 1972 to 1994,
whereas these rates increased significantly year by year in the other 15
countries during the examined period in each country. Twinning rates increased
from 1.2-fold in Austria to 2-fold in Denmark from 1972 to 1996. As for triplets,
the rate increased from 3-fold in Denmark to 9-fold in Norway during that period.
With one exception, that being the Slovak Republic, the triplet rate was highest
in the Scandinavian countries, followed by the other European and Asian
countries. The rising twinning and triplet rates have been attributed to the
higher proportion of mothers treated with ovulation-inducing hormones and
partially attributed to IVF.
PMID- 10783769
TI - Quantitative estimates of ABH secretion in saliva of human twins.
AB - Blood and saliva samples of 122 like-sexed twin pairs (65 MZ and 57 DZ) living in
Chandigarh (India) were analyzed for ABH polymorphism. The results indicated that
ABH secretions were independent of ABO blood groups though there was an
indication of higher incidence of non-secretors among 'O' blood group twin
individuals. No significant differences were observed between twins and
singletons in secretor gene frequency estimates. The quantitative data revealed
that mean titre scores for H substances were lower than that for A and B
substances. F test contrasting intra-pair variance between zygosities for ABH
quantitative secretions was highly significant indicating stronger genetic
component of variation. The results suggested that quantitative assay of ABH
secretions would be a better indicator for zygosity determination than mere
qualitative differentiation.
PMID- 10783770
TI - Mosaic partial trisomy of chromosome 5 (q33-q ter) associated with fetal
polycystic kidneys.
AB - A case of de novo mosaic partial trisomy of chromosome 5 (q33-q ter) in a
stillborn male fetus with bilateral polycystic kidneys, and atrial septal defect,
is reported. Fetal cord blood sampling was carried out at 25 weeks of gestation
because of bilateral polycystic kidneys with severe oligohydramnios observed on
ultrasound examination of the fetus. The family history was notable for the
presence of similar phenotypic abnormality in the mother and sibling. However, no
chromosomal abnormality was detected in other family members. Significance of
this rare chromosomal abnormality and its association with congenital
malformations in the fetus and in the family is being discussed.
PMID- 10783771
TI - Wildlife population assessment: past developments and future directions.
AB - We review the major developments in wildlife population assessment in the past
century. Three major areas are considered: mark-recapture, distance sampling, and
harvest models. We speculate on how these fields will develop in the next
century. Topics for which we expect to see methodological advances include
integration of modeling with Geographic Information Systems, automated survey
design algorithms, advances in model-based inference from sample survey data, a
common inferential framework for wildlife population assessment methods, improved
methods for estimating population trends, the embedding of biological process
models into inference, substantially improved models for conservation management,
advanced spatiotemporal models of ecosystems, and greater emphasis on
incorporating model selection uncertainty into inference. We discuss the kind of
developments that might be anticipated in these topics.
PMID- 10783772
TI - Bayesian detection of clusters and discontinuities in disease maps.
AB - An interesting epidemiological problem is the analysis of geographical variation
in rates of disease incidence or mortality. One goal of such an analysis is to
detect clusters of elevated (or lowered) risk in order to identify unknown risk
factors regarding the disease. We propose a nonparametric Bayesian approach for
the detection of such clusters based on Green's (1995, Biometrika 82, 711-732)
reversible jump MCMC methodology. The prior model assumes that geographical
regions can be combined in clusters with constant relative risk within a cluster.
The number of clusters, the location of the clusters, and the risk within each
cluster is unknown. This specification can be seen as a change-point problem of
variable dimension in irregular, discrete space. We illustrate our method through
an analysis of oral cavity cancer mortality rates in Germany and compare the
results with those obtained by the commonly used Bayesian disease mapping method
of Besag, York, and Mollie (1991, Annals of the Institute of Statistical
Mathematics, 43, 1-59).
PMID- 10783773
TI - Methodology for estimating the abundance of rare animals: seabird nesting on
north east Herald Cay.
AB - We discuss the problem of estimating the number of nests of different species of
seabirds on North East Herald Cay based on the data from a 1996 survey of
quadrats along transects and data from similar past surveys. We consider three
approaches based on different plausible models, namely a conditional negative
binomial model that allows for additional zeroes in the data, a weighting
approach (based on a heteroscedastic regression model), and a transform-both
sides regression approach. We find that the conditional negative binomial
approach and a linear regression approach work well but that the transform-both
sides approach should not be used. We apply the conditional negative binomial and
linear regression approaches with poststratification based on data quality and
availability to estimate the number of frigatebird nests on North East Herald
Cay.
PMID- 10783774
TI - Semiparametric regression for periodic longitudinal hormone data from multiple
menstrual cycles.
AB - We consider semiparametric regression for periodic longitudinal data. Parametric
fixed effects are used to model the covariate effects and a periodic
nonparametric smooth function is used to model the time effect. The within
subject correlation is modeled using subject-specific random effects and a random
stochastic process with a periodic variance function. We use maximum penalized
likelihood to estimate the regression coefficients and the periodic nonparametric
time function, whose estimator is shown to be a periodic cubic smoothing spline.
We use restricted maximum likelihood to simultaneously estimate the smoothing
parameter and the variance components. We show that all model parameters can be
easily obtained by fitting a linear mixed model. A common problem in the analysis
of longitudinal data is to compare the time profiles of two groups, e.g., between
treatment and placebo. We develop a scaled chi-squared test for the equality of
two nonparametric time functions. The proposed model and the test are illustrated
by analyzing hormone data collected during two consecutive menstrual cycles and
their performance is evaluated through simulations.
PMID- 10783775
TI - Localization of a quantitative trait locus via a Bayesian approach.
AB - A Bayesian approach to the direct mapping of a quantitative trait locus (QTL),
fully utilizing information from multiple linked gene markers, is presented in
this paper. The joint posterior distribution (a mixture distribution modeling the
linkage between a biallelic QTL and N gene markers) is computationally
challenging and invites exploration via Markov chain Monte Carlo methods. The
parameter's complete marginal posterior densities are obtained, allowing a
diverse range of inferences. Parameters estimated include the QTL genotype
probabilities for the sires and the offspring, the allele frequencies for the
QTL, and the position and additive and dominance effects of the QTL. The
methodology is applied through simulation to a half-sib design to form an outbred
pedigree structure where there is an entire class of missing information. The
capacity of the technique to accurately estimate parameters is examined for a
range of scenarios.
PMID- 10783776
TI - Accounting for variability in the use of permutation testing to detect
quantitative trait loci.
AB - Locating quantitative trait loci (QTL), or genomic regions associated with known
molecular markers, is of increasing interest in a wide variety of applications
ranging from human genetics to agricultural genetics. The hope of locating QTL
(or genes) affecting a quantitative trait is that it will lead to
characterization and possible manipulations of these genes. However, the
complexity of both statistical and genetic issues surrounding the location of
these regions calls into question the asymptotic statistical results supplying
the distribution of the test statistics employed. Coupled with the power of
current-day computing, permutation theory was reintroduced for the purpose of
estimating the distribution of any test statistic used to test for the location
of QTL. Permutation techniques have offered an attractive alternative to
significance measures based on asymptotic theory. The ideas of permutation
testing are extended in this application to include confidence intervals for the
thresholds and p-values estimated in permutation testing procedures. The
confidence intervals developed account for the Monte Carlo error associated with
practical applications of permutation testing and lead to an effective method of
determining an efficient permutation sample size.
PMID- 10783777
TI - Estimation of age-specific breeding probabilities from capture-recapture data.
AB - We provide a new method for estimating the age-specific breeding probabilities
from recaptures or resightings of animals marked as young. Our method is more
direct than previous methods and allows the modeler to fit and compare models
where the age-specific breeding proportions are equal over different cohorts or
are a function of external covariates.
PMID- 10783778
TI - Estimating data transformations in nonlinear mixed effects models.
AB - A routine practice in the analysis of repeated measurement data is to represent
individual responses by a mixed effects model on some transformed scale. For
example, for pharmacokinetic, growth, and other data, both the response and the
regression model are typically transformed to achieve approximate within
individual normality and constant variance on the new scale; however, the choice
of transformation is often made subjectively or by default, with adoption of a
standard choice such as the log. We propose a mixed effects framework based on
the transform-both-sides model, where the transformation is represented by a
monotone parametric function and is estimated from the data. For this model, we
describe a practical fitting strategy based on approximation of the marginal
likelihood. Inference is complicated by the fact that estimation of the
transformation requires modification of the usual standard errors for estimators
of fixed effects; however, we show that, under conditions relevant to common
applications, this complication is asymptotically negligible, allowing
straightforward implementation via standard software.
PMID- 10783779
TI - Random effects modeling of multiple binomial responses using the multivariate
binomial logit-normal distribution.
AB - The multivariate binomial logit-normal distribution is a mixture distribution for
which, (i) conditional on a set of success probabilities and sample size indices,
a vector of counts is independent binomial variates, and (ii) the vector of
logits of the parameters has a multivariate normal distribution. We use this
distribution to model multivariate binomial-type responses using a vector of
random effects. The vector of logits of parameters has a mean that is a linear
function of explanatory variables and has an unspecified or partly specified
covariance matrix. The model generalizes and provides greater flexibility than
the univariate model that uses a normal random effect to account for positive
correlations in clustered data. The multivariate model is useful when different
elements of the response vector refer to different characteristics, each of which
may naturally have its own random effect. It is also useful for repeated binary
measurement of a single response when there is a nonexchangeable association
structure, such as one often expects with longitudinal data or when negative
association exists for at least one pair of responses. We apply the model to an
influenza study with repeated responses in which some pairs are negatively
associated and to a developmental toxicity study with continuation-ratio logits
applied to an ordinal response with clustered observations.
PMID- 10783780
TI - Generalized nonlinear models for pharmacokinetic data.
AB - Phase I trials to study the pharmacokinetic properties of a new drug generally
involve a restricted number of healthy volunteers. Because of the nature of the
group involved in such studies, the appropriate distributional assumptions are
not always obvious. These model assumptions include the actual distribution but
also the ways in which the dispersion of responses is allowed to vary over time
and the fact that small concentrations of a substance are not easily detectable
and hence are left censored. We propose that a reasonably wide class of
generalized nonlinear models allowing for left censoring be considered now that
this is feasible with current computer power and sophisticated statistical
packages. These modelling strategies are applied to a Phase I study of the drug
flosequinan and its metabolite. This drug was developed for the treatment of
heart failure. Because the metabolite also exhibits an active pharmacologic
effect, study of both the parent drug and the metabolite is of interest.
PMID- 10783781
TI - Self-modeling for two-dimensional response curves.
AB - Two-dimensional response curves are an important experimental outcome in speech
kinematics and other areas of research. These parameterized curves are usually
obtained by recording the two-dimensional location of an object over time. In
this setting, time is the independent variable and the x and y locations on
specified coordinate axes define the multivariate response. Collections of such
parameterized curves can be obtained either from one subject or from a number of
different subjects, each producing one or several realizations of the response
curve. When only one dependent variable is observed over time and no parametric
model is specified, self-modeling regression (SEMOR) is an attractive modeling
approach. SEMOR assumes that each of a collection of curves differs from a
smooth, average shape function by some simple parametric transformation of the
coordinate axes (usually linear). We will describe the extension of SEMOR to two
dimensional parameterized curves using affine transformations of a two
dimensional, time-parameterized shape function.
PMID- 10783782
TI - Conditional-cumulant-of-exposure method in logistic missing covariate regression.
AB - We consider estimation in logistic regression where some covariate variables may
be missing at random. Satten and Kupper (1993, Journal of the American
Statistical Association 88, 200-208) proposed estimating odds ratio parameters
using methods based on the probability of exposure. By approximating a partial
likelihood, we extend their idea and propose a method that estimates the cumulant
generating function of the missing covariate given observed covariates and
surrogates in the controls. Our proposed method first estimates some lower order
cumulants of the conditional distribution of the unobserved data and then solves
a resulting estimating equation for the logistic regression parameter. A simple
version of the proposed method is to replace a missing covariate by the summation
of its conditional mean and conditional variance given observed data in the
controls. We note that one important property of the proposed method is that,
when the validation is only on controls, a class of inverse selection probability
weighted semiparametric estimators cannot be applied because selection
probabilities on cases are zeroes. The proposed estimator performs well unless
the relative risk parameters are large, even though it is technically
inconsistent. Small-sample simulations are conducted. We illustrate the method by
an example of real data analysis.
PMID- 10783783
TI - Weighted normality-based estimator in correcting correlation coefficient
estimation between incomplete nutrient measurements.
AB - Consider the problem of estimating the correlation between two nutrient
measurements, such as the percent energy from fat obtained from a food frequency
questionnaire (FFQ) and that from repeated food records or 24-hour recalls. Under
a classical additive model for repeated food records, it is known that there is
an attenuation effect on the correlation estimation if the sample average of
repeated food records for each subject is used to estimate the underlying long
term average. This paper considers the case in which the selection probability of
a subject for participation in the calibration study, in which repeated food
records are measured, depends on the corresponding FFQ value, and the repeated
longitudinal measurement errors have an autoregressive structure. This paper
investigates a normality-based estimator and compares it with a simple method of
moments. Both methods are consistent if the first two moments of nutrient
measurements exist. Furthermore, joint estimating equations are applied to
estimate the correlation coefficient and related nuisance parameters
simultaneously. This approach provides a simple sandwich formula for the
covariance estimation of the estimator. Finite sample performance is examined via
a simulation study, and the proposed weighted normality-based estimator performs
well under various distributional assumptions. The methods are applied to real
data from a dietary assessment study.
PMID- 10783784
TI - A graphical method for finding maximin efficiency designs.
AB - We consider the problem of designing an experiment when there are two competing
optimality criteria. Designs that maximize the minimum efficiencies under the two
criteria are proposed along with a graphical method for finding these maximin
designs.
PMID- 10783785
TI - Substantial gains in bias reduction from matching with a variable number of
controls.
AB - In observational studies that match several controls to each treated subject,
substantially greater bias reduction is possible if the number of controls is not
fixed but rather is allowed to vary from one matched set to another. In certain
cases, matching with a fixed number of controls may remove only 50% of the bias
in a covariate, whereas matching with a variable number of controls may remove
90% of the bias, even though both control groups have the same number of controls
in total. An example of matching in a study of surgical mortality is discussed in
detail.
PMID- 10783786
TI - Estimation and testing with overdispersed proportions using the beta-logistic
regression model of Heckman and Willis.
AB - Methods are presented for modeling dose-related effects in proportion data when
extra-binomial variability is a concern. Motivation is taken from experiments in
developmental toxicology, where similarity among conceptuses within a litter
leads to intralitter correlations and to overdispersion in the observed
proportions. Appeal is made to the well-known beta-binomial distribution to
represent the overdispersion. From this, an exponential function of the linear
predictor is used to model the dose-response relationship. The specification was
introduced previously for econometric applications by Heckman and Willis; it
induces a form of logistic regression for the mean response, together with a
reciprocal biexponential model for the intralitter correlation. Large-sample,
likelihood-based methods for estimating and testing the joint proportion
correlation response are studied. A developmental toxicity data set illustrates
the methods.
PMID- 10783787
TI - A homogeneity test in overviews with group sequentially monitored clinical
trials.
AB - It is known that using statistical stopping rules in clinical trials can create
an artificial heterogeneity of treatment effects in overviews of related trials
(Hughes, Freedman, and Pocock, 1992, Biometrics 48, 41-53). If the true treatment
effect being tested is small, as is often the case, the homogeneity test by
DerSimonian and Laird (1986, Controlled Clinical Trials 7, 177-188) violates the
size of the test very severely. This paper provides a new homogeneity test, which
preserves the size of the test more accurately. The operating characteristics of
the new test are examined through simulations.
PMID- 10783788
TI - Negative binomial additive models.
AB - The generalized additive model is extended to handle negative binomial responses.
The extension is complicated by the fact that the negative binomial distribution
has two parameters and is not in the exponential family. The methodology is
applied to data involving DNA adduct counts and smoking variables among ex
smokers with lung cancer. A more detailed investigation is made of the parametric
relationship between the number of adducts and years since quitting while
retaining a smooth relationship between adducts and the other covariates.
PMID- 10783789
TI - Testing for differences in survival with delayed ascertainment.
AB - During the interim stages of most large-scale clinical trials, knowledge that a
patient is alive or dead is usually not up-to-date. This is due to the pattern of
patient visits to hospitals as well as the administrative set-up used by the
study to obtain information on vital status. On a two-armed study, if the process
of ascertaining vital status is not the same in both treatment groups, then the
standard method of testing based on the logrank statistic may not be applicable.
Instead, an ad hoc modification to the logrank test, which artificially truncates
follow-up prior to the time of analysis, is often used. These approaches have not
been formally addressed in the literature. In the early stages of a clinical
trial, severe bias or loss of power may result. For this situation, we propose a
class of test statistics that extends the usual class of U statistics. Asymptotic
normality is derived by reformulating the statistics in terms of counting
processes and employing the theory of U statistics along with martingale
techniques. For early interim analyses, a numerical study indicates that the new
tests can be more powerful than the current practice when differential
ascertainment is present. To illustrate the potential loss of information when
lagging follow-up to control for ascertainment delays, we reanalyze an AIDS
clinical trial with the truncated logrank and the new statistics.
PMID- 10783790
TI - Testing equality of survival functions based on both paired and unpaired censored
data.
AB - We introduce two test procedures for comparing two survival distributions on the
basis of randomly right-censored data consisting of both paired and unpaired
observations. Our procedures are based on generalizations of a pooled rank test
statistic previously proposed for uncensored data. One generalization adapts the
Prentice-Wilcoxon score, while the other adapts the Akritas score. The use of
these particular scoring systems in pooled rank tests with randomly right
censored paired data has been advocated by several researchers. Our test
procedures utilize the permutation distributions of the test statistics based on
a novel manner of permuting the scores. Permutation versions of tests for right
censored paired data and for two independent right-censored samples that use the
proposed scoring systems are obtained as special cases of our test procedures.
Simulation results show that our test procedures have high power for detecting
scale and location shifts in exponential and log-logistic distributions for the
survival times. We also demonstrate the advantages of our test procedures in
terms of utilizing randomly occurring unpaired observations that are discarded in
test procedures for paired data. The tests are applied to skin graft data
previously reported elsewhere.
PMID- 10783791
TI - A linear mixed-effects model for multivariate censored data.
AB - We apply a linear mixed-effects model to multivariate failure time data.
Computation of the regression parameters involves the Buckley-James method in an
iterated Monte Carlo expectation-maximization algorithm, wherein the Monte Carlo
E-step is implemented using the Metropolis-Hastings algorithm. From simulation
studies, this approach compares favorably with the marginal independence
approach, especially when there is a strong within-cluster correlation.
PMID- 10783792
TI - Estimation of sojourn time in chronic disease screening without data on interval
cases.
AB - Estimation of the sojourn time on the preclinical detectable period in disease
screening or transition rates for the natural history of chronic disease usually
rely on interval cases (diagnosed between screens). However, to ascertain such
cases might be difficult in developing countries due to incomplete registration
systems and difficulties in follow-up. To overcome this problem, we propose three
Markov models to estimate parameters without using interval cases. A three-state
Markov model, a five-state Markov model related to regional lymph node spread,
and a five-state Markov model pertaining to tumor size are applied to data on
breast cancer screening in female relatives of breast cancer cases in Taiwan.
Results based on a three-state Markov model give mean sojourn time (MST) 1.90
(95% CI: 1.18-4.86) years for this high-risk group. Validation of these models on
the basis of data on breast cancer screening in the age groups 50-59 and 60-69
years from the Swedish Two-County Trial shows the estimates from a three-state
Markov model that does not use interval cases are very close to those from
previous Markov models taking interval cancers into account. For the five-state
Markov model, a reparameterized procedure using auxiliary information on
clinically detected cancers is performed to estimate relevant parameters. A good
fit of internal and external validation demonstrates the feasibility of using
these models to estimate parameters that have previously required interval
cancers. This method can be applied to other screening data in which there are no
data on interval cases.
PMID- 10783793
TI - Variance and sample size calculations in quality-of-life--adjusted survival
analysis (Q-TWiST).
AB - The Quality-Adjusted Time Without Symptoms or Toxicity (Q-TWiST) statistic
previously introduced by Glasziou, Simes and Gelber (1990, Statistics in Medicine
9, 1259-1276) combines toxicity, disease-free survival, and overall survival
information in assessing the impact of treatments on the lives of patients. This
methodology has received positive reviews from clinicians as intuitive and
useful, but to date, the variance of this statistic has remained unspecified. We
review aspects of the Q-TWiST method for analyzing clinical trial data, extend
the method to accommodate multiple treatment arms, and provide closed-form
asymptotic variance formulas. We also provide a framework for designing Q-TWiST
clinical trials with sample sizes determined using the derived asymptotic
variance formulas. Trials currently collecting quality of life data did not have
the benefit of these sample size calculation techniques in designing their
studies.
PMID- 10783794
TI - A two-sample comparison for multiple ordered event data.
AB - A longitudinal study is conducted to compare the process of particular disease
between two groups. The process of the disease is monitored according to which of
several ordered events occur. In the paper, the sojourn time between two
successive events is considered as the outcome of interest. The group effects on
the sojourn times of the multiple events are parameterized by scale changes in a
semiparametric accelerated failure time model where the dependence structure
among the multivariate sojourn times is unspecified. Suppose that the sojourn
times are subject to dependent censoring and the censoring times are observed for
all subjects. A log-rank-type estimating approach by rescaling the sojourn times
and the dependent censoring times into the same distribution is constructed to
estimate the group effects and the corresponding estimators are consistent and
asymptotically normal. Without the dependent censoring, the independent censoring
times in general are not available for the uncensored data. In order to complete
the censoring information, pseudo-censoring times are generated from the
corresponding nonparametrically estimated survival function in each group, and we
can still obtained unbiased estimating functions for the group effects. A real
application and a simulation study are conducted to illustrate the proposed
methods.
PMID- 10783795
TI - Analysis of a two-stage case-control study with cluster sampling of controls:
application to nonmelanoma skin cancer.
AB - We present a pseudolikelihood approach for analyzing a two-stage population-based
case-control study with cluster sampling of controls. These methods were
developed to analyze data from a study of nonmelanoma skin cancer (NMSC). This
study was designed to evaluate the role of ultraviolet radiation (UVB) on NMSC
risk while adjusting for age group, which is known for all subjects, and for
other individual-level factors, such as susceptibility to sunburn, which are
known only for participants in the case-control study. The methods presented
yield estimates of relative and absolute risk, with standard errors, while
accounting naturally for the two-stage sampling of the cohort and cluster
sampling of controls.
PMID- 10783796
TI - A multiple imputation approach to Cox regression with interval-censored data.
AB - We propose a general semiparametric method based on multiple imputation for Cox
regression with interval-censored data. The method consists of iterating the
following two steps. First, from finite-interval-censored (but not right
censored) data, exact failure times are imputed using Tanner and Wei's poor man's
or asymptotic normal data augmentation scheme based on the current estimates of
the regression coefficient and the baseline survival curve. Second, a standard
statistical procedure for right-censored data, such as the Cox partial likelihood
method, is applied to imputed data to update the estimates. Through simulation,
we demonstrate that the resulting estimate of the regression coefficient and its
associated standard error provide a promising alternative to the nonparametric
maximum likelihood estimate. Our proposal is easily implemented by taking
advantage of existing computer programs for right-censored data.
PMID- 10783798
TI - Approximate Bayesian evaluation of multiple treatment effects.
AB - We propose an approximate Bayesian method for comparing an experimental treatment
to a control based on a randomized clinical trial with multivariate patient
outcomes. Overall treatment effect is characterized by a vector of parameters
corresponding to effects on the individual patient outcomes. We partition the
parameter space into four sets where, respectively, the experimental treatment is
superior to the control, the control is superior to the experimental, the two
treatments are equivalent, and the treatment effects are discordant. We compute
posterior probabilities of the parameter sets by treating an estimator of the
parameter vector like a random variable in the Bayesian paradigm. The
approximation may be used in any setting where a consistent, asymptotically
normal estimator of the parameter vector is available. The method is illustrated
by application to a breast cancer data set consisting of multiple time-to-event
outcomes with covariates and to count data arising from a cross-classification of
response, infection, and treatment in an acute leukemia trial.
PMID- 10783797
TI - Use of binomial group testing in tests of hypotheses for classification or
quantitative covariables.
AB - In group testing, the test unit consists of a group of individuals. If the group
test is positive, then one or more individuals in the group are assumed to be
positive. A group observation in binomial group testing can be, say, the test
result (positive or negative) for a pool of blood samples that come from several
different individuals. It has been shown that, when the proportion (p) of
infected individuals is low, group testing is often preferable to individual
testing for identifying infected individuals and for estimating proportions of
those infected. We extend the potential applications of group testing to
hypothesis-testing problems wherein one wants to test for a relationship between
p and a classification or quantitative covariable. Asymptotic relative
efficiencies (AREs) of tests based on group testing versus the usual individual
testing are obtained. The Pitman ARE strongly favors group testing in many cases.
Small-sample results from simulation studies are given and are consistent with
the large-sample (asymptotic) findings. We illustrate the potential advantages of
group testing in hypothesis testing using HIV-1 seroprevalence data.
PMID- 10783799
TI - Bayesian nonparametric inference on the dose level with specified response rate.
AB - The richness of nonparametric Bayesian models has attracted many different
applications. Its application in dose-finding studies has been hindered due to
lack of methodologies on the nonparametric Bayesian inference on percentiles. The
primary interest in dose-finding studies focuses inference on the unknown
toxicity or efficacy dose level corresponding to a prespecified rate. This paper
shows how this problem may generally be handled by deriving inference on
percentiles of a distribution following a Dirichlet process prior. In particular,
theoretical results are derived to obtain the nonparametric Bayesian inference of
the unknown dose level. This is followed by a description of the numerical
implementation of that theory. The method also allows efficient estimation of the
entire potency curve. Finally, the usefulness of the approach is demonstrated via
an experimental data example.
PMID- 10783800
TI - Estimation in a Cox proportional hazards cure model.
AB - Some failure time data come from a population that consists of some subjects who
are susceptible to and others who are nonsusceptible to the event of interest.
The data typically have heavy censoring at the end of the follow-up period, and a
standard survival analysis would not always be appropriate. In such situations
where there is good scientific or empirical evidence of a nonsusceptible
population, the mixture or cure model can be used (Farewell, 1982, Biometrics 38,
1041-1046). It assumes a binary distribution to model the incidence probability
and a parametric failure time distribution to model the latency. Kuk and Chen
(1992, Biometrika 79, 531-541) extended the model by using Cox's proportional
hazards regression for the latency. We develop maximum likelihood techniques for
the joint estimation of the incidence and latency regression parameters in this
model using the nonparametric form of the likelihood and an EM algorithm. A zero
tail constraint is used to reduce the near nonidentifiability of the problem. The
inverse of the observed information matrix is used to compute the standard
errors. A simulation study shows that the methods are competitive to the
parametric methods under ideal conditions and are generally better when censoring
from loss to follow-up is heavy. The methods are applied to a data set of tonsil
cancer patients treated with radiation therapy.
PMID- 10783801
TI - A nonparametric mixture model for cure rate estimation.
AB - Nonparametric methods have attracted less attention than their parametric
counterparts for cure rate analysis. In this paper, we study a general
nonparametric mixture model. The proportional hazards assumption is employed in
modeling the effect of covariates on the failure time of patients who are not
cured. The EM algorithm, the marginal likelihood approach, and multiple
imputations are employed to estimate parameters of interest in the model. This
model extends models and improves estimation methods proposed by other
researchers. It also extends Cox's proportional hazards regression model by
allowing a proportion of event-free patients and investigating covariate effects
on that proportion. The model and its estimation method are investigated by
simulations. An application to breast cancer data, including comparisons with
previous analyses using a parametric model and an existing nonparametric model by
other researchers, confirms the conclusions from the parametric model but not
those from the existing nonparametric model.
PMID- 10783802
TI - Active life expectancy from annual follow-up data with missing responses.
AB - Active life expectancy (ALE) at a given age is defined as the expected remaining
years free of disability. In this study, three categories of health status are
defined according to the ability to perform activities of daily living
independently. Several studies have used increment-decrement life tables to
estimate ALE, without error analysis, from only a baseline and one follow-up
interview. The present work conducts an individual-level covariate analysis using
a three-state Markov chain model for multiple follow-up data. Using a logistic
link, the model estimates single-year transition probabilities among states of
health, accounting for missing interviews. This approach has the advantages of
smoothing subsequent estimates and increased power by using all follow-ups. We
compute ALE and total life expectancy from these estimated single-year transition
probabilities. Variance estimates are computed using the delta method. Data from
the Iowa Established Population for the Epidemiologic Study of the Elderly are
used to test the effects of smoking on ALE on all 5-year age groups past 65
years, controlling for sex and education.
PMID- 10783803
TI - Predictive accuracy and explained variation in Cox regression.
AB - We suggest a new measure of the proportion of the variation of possibly censored
survival times explained by a given proportional hazards model. The proposed
measure, termed V, shares several favorable properties with an earlier V1 but
also improves the handling of censoring. The statistic contrasts distance
measures between individual 1/0 survival processes and fitted survival curves
with and without covariate information. These distance measures, Dx and D,
respectively, are themselves informative as summaries of absolute rather than
relative predictive accuracy. We recommend graphical comparisons of survival
curves for prognostic index groups to improve the understanding of obtained
values for V, Dx, and D. Their use and interpretation is exemplified for a
Yorkshire lung cancer study on survival. From this and an overview for several
well-known clinical data sets, we show that the likely amount of relative or
absolute predictive accuracy is often low even if there are highly significant
and relatively strong prognostic factors.
PMID- 10783804
TI - Bayesian information criterion for censored survival models.
AB - We investigate the Bayesian Information Criterion (BIC) for variable selection in
models for censored survival data. Kass and Wasserman (1995, Journal of the
American Statistical Association 90, 928-934) showed that BIC provides a close
approximation to the Bayes factor when a unit-information prior on the parameter
space is used. We propose a revision of the penalty term in BIC so that it is
defined in terms of the number of uncensored events instead of the number of
observations. For a simple censored data model, this revision results in a better
approximation to the exact Bayes factor based on a conjugate unit-information
prior. In the Cox proportional hazards regression model, we propose defining BIC
in terms of the maximized partial likelihood. Using the number of deaths rather
than the number of individuals in the BIC penalty term corresponds to a more
realistic prior on the parameter space and is shown to improve predictive
performance for assessing stroke risk in the Cardiovascular Health Study.
PMID- 10783805
TI - The combination of population pharmacokinetic studies.
AB - Pharmacokinetic data consist of drug concentrations with associated known
sampling times and are collected following the administration of known dosage
regimens. Population pharmacokinetic data consist of such data on a number of
individuals, possibly along with individual-specific characteristics. During drug
development, a number of population pharmacokinetic studies are typically carried
out and the combination of such studies is of great importance for characterizing
the drug and, in particular, for the design of future studies. In this paper, we
describe a model that may be used to combine population pharmacokinetic data. The
model is illustrated using six phase I studies of the antiasthmatic drug
fluticasone propionate. Our approach is Bayesian and computation is carried out
using Markov chain Monte Carlo. We provide a number of simplifications to the
model that may be made in order to ease simulation from the posterior
distribution.
PMID- 10783806
TI - The impact of restrictive entry criterion during the placebo lead-in period.
AB - In the study of depression, most randomized clinical trials have design features
that attempt to sample from a stable patient population. One commonly used design
feature is to require patients to maintain some minimum baseline symptom severity
score during a placebo lead-in period. One intent of this design feature is to
evaluate the behavior of patients prior to administration of active medication.
If, during the lead-in period, patients do not maintain minimum symptom severity,
the patients are excluded from the remainder of the study, the theory being that
the excluded patients are not part of a stable patient population and hence are
not likely to demonstrate efficacy of a truly effective treatment. This
presentation investigates the effectiveness of a restrictive entry criterion and
proposes an alternative explanation for what is usually defined as placebo
response.
PMID- 10783807
TI - Mixed effects logistic regression models for longitudinal ordinal functional
response data with multiple-cause drop-out from the longitudinal study of aging.
AB - In the context of analyzing ordinal functional limitation responses from the
Longitudinal Study of Aging, we investigate the association between current
functional limitation and previous year's limitation and its modification by
physical activity and multiple causes of drop-out. We accommodate the
longitudinal nature of the multiple causes of informative drop-out (death and
unknown loss-to-follow-up) with a mixed effects logistic model. Under the
proposed model with a random intercept and slope, the ordinal functional outcome
and multiple discrete time survival profiles share a common random effect
structure. This shared parameter selection model assumes that the multiple causes
of drop-out are conditionally independent of the functional limitation outcome
given the underlying random effect representing an individual's trajectory of
general health status across time. Although it is not possible to fully assess
the adequacy of this assumption, we assess the robustness of the approach by
varying the assumptions underlying the proposed model, such as the random effects
distribution and the drop-out component. It appears that between-subject
differences in initial functional limitation are strongly associated with future
functional limitation and that this association is stronger for those who do not
have physical activity regardless of the random effects and informative drop-out
specifications. In contrast, the association between current functional
limitation and previous trajectory of functional status within an individual is
weaker and more sensitive to changes in the random effects and drop-out
assumptions.
PMID- 10783808
TI - Modeling human fertility in the presence of measurement error.
AB - The probability of conception in a given menstrual cycle is closely related to
the timing of intercourse relative to ovulation. Although commonly used markers
of time of ovulation are known to be error prone, most fertility models assume
the day of ovulation is measured without error. We develop a mixture model that
allows the day to be misspecified. We assume that the measurement errors are
i.i.d. across menstrual cycles. Heterogeneity among couples in the per cycle
likelihood of conception is accounted for using a beta mixture model. Bayesian
estimation is straightforward using Markov chain Monte Carlo techniques. The
methods are applied to a prospective study of couples at risk of pregnancy. In
the absence of validation data or multiple independent markers of ovulation, the
identifiability of the measurement error distribution depends on the assumed
model. Thus, the results of studies relating the timing of intercourse to the
probability of conception should be interpreted cautiously.
PMID- 10783809
TI - A comparison study of models and fitting procedures for biphasic viral dynamics
in HIV-1 infected patients treated with antiviral therapies.
AB - The study of HIV dynamics is one of the most important developments in recent
AIDS research. It has led to a new understanding of the pathogenesis of HIV
infection. But, although important findings in HIV dynamics have been published
in prestigious scientific journals in the last 5 years, the model-fitting
procedures used in these publications have not been studied in any detail. In
this paper, we evaluate the performance of four model-fitting procedures proposed
and used in biphasic HIV dynamic data analysis via extensive Monte Carlo
simulations. We propose some guidelines for practitioners to select an
appropriate method for their own data analysis. Real data examples from an AIDS
clinical trial are provided as illustrations.
PMID- 10783810
TI - Comment on Quan and Shih's "Assessing reproducibility by the within-subject
coefficient of variation with random effects models".
PMID- 10783811
TI - Computer-assisted analysis of mixtures.
PMID- 10783812
TI - Estimating risk difference in multicenter studies under baseline-risk
heterogeneity.
AB - In this paper, we consider the case of efficient estimation of the risk
difference in a multicenter study allowing for baseline heterogeneity. We
consider the optimally weighted estimator for the common risk difference and show
that this estimator has considerable bias when the true weights (which are
inversely proportional to the variances of the center-specific risk difference
estimates) are replaced by their sample estimates. In addition, we propose a new
estimator for this situation of the Mantel-Haenszel type that is unbiased and, in
addition, has a smaller variance for small sample sizes within the study centers.
Simulations illustrate these findings.
PMID- 10783813
TI - A revisit on tests for homogeneity of the risk difference.
AB - Lipsitz et al. (1998, Biometrics 54, 148-160) discussed testing the homogeneity
of the risk difference for a series of 2 x 2 tables. They proposed and evaluated
several weighted test statistics, including the commonly used weighted least
squares test statistic. Here we suggest various important improvements on these
test statistics. First, we propose using the one-sided analogues of the test
procedures proposed by Lipsitz et al. because we should only reject the null
hypothesis of homogeneity when the variation of the estimated risk differences
between centers is large. Second, we generalize their study by redesigning the
simulations to include the situations considered by Lipsitz et al. (1998) as
special cases. Third, we consider a logarithmic transformation of the weighted
least squares test statistic to improve the normal approximation of its sampling
distribution. On the basis of Monte Carlo simulations, we note that, as long as
the mean treatment group size per table is moderate or large (> or = 16), this
simple test statistic, in conjunction with the commonly used adjustment procedure
for sparse data, can be useful when the number of 2 x 2 tables is small or
moderate (< or = 32). In these situations, in fact, we find that our proposed
method generally outperforms all the statistics considered by Lipsitz et al.
Finally, we include a general guideline about which test statistic should be used
in a variety of situations.
PMID- 10783814
TI - Understanding and managing cancer pain.
PMID- 10783815
TI - Neurophysiology of cancer pain.
AB - BACKGROUND: Recent basic science research has greatly added to our knowledge of
pain mechanisms. Application of this knowledge to cancer pain syndromes has led
to new and innovative approaches to cancer pain management. METHODS: The
mechanisms involved in the three main cancer pain syndromes (somatic, visceral,
and neuropathic) are reviewed, and various therapeutic options are discussed.
RESULTS: Advances in knowledge in neurophysiology, neuroanatomy, and pharmacology
have allowed a greater understanding of the peripheral and central mechanisms of
pain. New drugs and interventional techniques based on this knowledge have
improved the control of cancer pain. CONCLUSIONS: Understanding the
neurophysiology of cancer pain promotes use of the most appropriate palliative
measures for pain control.
PMID- 10783816
TI - Cancer pain management.
AB - BACKGROUND: Controlling pain in cancer patients is often inadequate. A recent
multicenter study of patients with metastatic disease who were experiencing pain
reported that 36% still had pain severe enough to compromise their daily
function. METHODS: The author draws on his experiences as well as those of others
to review general guidelines and provide specific recommendations for cancer pain
management. RESULTS: Three components are critical to managing cancer pain:
assessing pain, establishing an appropriate therapeutic opioid regimen, and
integrating with other therapies. An appropriate therapeutic opioid regimen
involves initiating, consolidating and maintaining therapy. Other strategies
(e.g., advanced pharmacological, adjuvant, interventional, and psychological) can
be added to opioid therapy. CONCLUSIONS: A revision of the Agency for Health Care
Policy and Research Cancer Pain Guidelines is currently underway. The management
of pain in cancer patients should include more frequent reassessment of both
analgesia and side effects to ensure optimal cancer pain relief.
PMID- 10783817
TI - Routes of opioid analgesic therapy in the management of cancer pain.
AB - BACKGROUND: The availability of various routes of administration of opioid
analgesics can be confusing when determining an appropriate, efficacious, and
cost-effective regimen to manage cancer pain. METHODS: The indications,
contraindications, and pharmacokinetic properties of oral, intravenous,
subcutaneous, transdermal, transmucosal, rectal, and perispinal routes of opioid
administration are reviewed. RESULTS: To determine the most efficacious, cost
effective, and user-friendly option to manage cancer pain, several factors must
be considered: the ability of the patient to use a specific type of delivery
system, the efficacy of that system to deliver acceptable analgesia, the ease of
use for the patient and family, the potential or actual complications associated
with that system, and the cost. CONCLUSIONS: Administering opioids to manage
cancer pain requires knowledge of potency relative to morphine and
bioavailability of the route chosen. Changes in the route, dosage, or opioid used
should be accompanied with close patient follow-up.
PMID- 10783818
TI - Critical evaluation of chemical neurolysis of the sympathetic axis for cancer
pain.
AB - BACKGROUND: Patients with pain caused by cancer frequently experience visceral
pain. In addition to oral pharmacologic therapy to manage pain, neurolytic blocks
of the sympathetic axis are also effective in controlling visceral cancer pain.
METHODS: Four types of neurolytic blocks (interpleural phenol, celiac plexus,
superior hypogastric plexus, and ganglion impar) used in the treatment of
visceral cancer pain are reviewed. RESULTS: Several studies have documented the
efficacy of neurolytic blocks in reducing pain intensity and opioid consumption.
However, the narrow risk-benefit ratio associated with neurolysis techniques
requires knowledge of the implications associated with the different neurolytic
blocks to minimize undesirable effects. CONCLUSIONS: Neurolysis of the
sympathetic axis has been shown to be an effective and safe approach to treat
visceral pain in cancer patients and should be incorporated in the armamentarium
of the pain specialist as a useful adjunct to oral pharmacologic therapy.
PMID- 10783819
TI - Interventional treatment of cancer pain: the fourth step in the World Health
Organization analgesic ladder?
AB - BACKGROUND: For most patients with cancer pain, the World Health Organization's
three-step analgesic ladder provides adequate management with oral or transdermal
options. However, some cancer patients are not well palliated with these
approaches. METHODS: The author reviews interventional options that include nerve
blocks, spinal administration of local anesthetics, opioids, alpha-2 agonists,
spinal cord stimulation, and surgical interventions. RESULTS: Numerous
interventional options are readily accessible and most can be performed on an
outpatient basis. They can be used as sole agents for the control of cancer pain
or as useful adjuncts to supplement analgesia provided by opioids, thus
decreasing opioid dose requirements and side effects. CONCLUSIONS: Cancer-related
pain can be controlled with several interventions when oral or transdermal
opioids are inadequate. A risk:benefit ratio should be considered before
implementing invasive analgesic methods.
PMID- 10783820
TI - Nonpharmacological interventions with chronic cancer pain in adults.
AB - BACKGROUND: Pain is often poorly controlled in cancer patients. Chronic pain
affects adult patients at all stages of cancer management. Optimal pain
management may require attention to psychosocial variables and the inclusion of
nonpharmacological techniques. METHODS: Three nonpharmacological strategies that
are effective in reducing pain caused by cancer--patient psycho-education,
supportive psychotherapy, and cognitive-behavioral interventions--are reviewed.
Recommendations for physicians to facilitate a mental health referral are also
discussed. RESULTS: Effective treatment of cancer pain begins with assessing the
severity, characteristics, and impact of pain. Emotional distress (especially
anxiety, depression, and beliefs about pain) has emerged as predictive of patient
pain levels. Appropriate pain management may require a multidisciplinary
approach. CONCLUSIONS: Patient psycho-education has empowered patients to
actively participate in pain control strategies. Supportive psychotherapy can
assist patients in managing the stressors associated with cancer, and cognitive
behavioral therapy helps patients to recognize and modify the factors that
contribute to physical and emotional distress.
PMID- 10783821
TI - Intravenous to oral (iv:po) anti-infective conversion therapy.
PMID- 10783822
TI - Erectile dysfunction in the cancer patient.
PMID- 10783823
TI - Disseminated cutaneous Mycobacterium chelonae infection.
PMID- 10783824
TI - Strategies for combining chemotherapy and biotherapy in melanoma.
PMID- 10783825
TI - P-glycoprotein inhibitor erythromycin increases oral bioavailability of talinolol
in humans.
AB - OBJECTIVE: Increased bioavailability of the P-glycoprotein (Pgp) substrates
digoxin and cyclosporin due to erythromycin has been observed in vivo. The aim of
the present study was to investigate the effect of orally administered
erythromycin on the oral bioavailability of the beta-blocker talinolol. Talinolol
is a suitable model compound for Pgp drug-drug interaction studies due to its Pgp
related active intestinal secretion and lack of any significant metabolism.
METHODS: In a randomized crossover study, the oral pharmacokinetics of talinolol
(50 mg) after a concomitant single oral dose of erythromycin (2 g) or placebo
were investigated in 9 healthy men. Concentrations of talinolol were measured in
serum and urine by HPLC. RESULTS: The area under the curve of talinolol serum
concentrations from 0 to 24 h (AUC(0-24)) and the maximum serum concentrations
(Cmax) were significantly increased after administration of erythromycin compared
to placebo. t(max) values were significantly reduced. The renal clearance (CLR)
of talinolol was unchanged after co-administration of erythromycin and there was
a small but statistically significant decrease in elimination half-life (t1/2).
Serum pharmacokinetics correlate with the results derived from urine
concentration measurement. One subject suffered from moderate diarrhea after
erythromycin and was excluded from the analysis. CONCLUSION: We suggest that the
increase in oral bioavailability of talinolol after concomitant erythromycin is
caused by increased intestinal net absorption due to Pgp inhibition by
erythromycin.
PMID- 10783826
TI - Affinities at the verapamil binding site of MDR1-encoded P-glycoprotein: drugs
and analogs, stereoisomers and metabolites.
AB - OBJECTIVES: The multidrug transporter P-glycoprotein (P-gp) appears to play a
significant role in drug absorption and disposition. Hence, it is of interest to
evaluate structure-affinity relationships for the purpose of making predictions.
METHODS: The affinity to P-gp of related molecular structures from various groups
of drugs was determined using competitive radioligand-binding assays. Structural
analogs, stereoisomers and metabolites of verapamil-type calcium antagonists,
beta-adrenoceptor antagonists as well as omeprazole, omeprazole enantiomers and
the sulfone metabolite of omeprazole were investigated. RESULTS: Whereas some
stereoselectivity was detected for the high-affinity P-gp substrates verapamil
and carvedilol, little or no differences were observed in the case of other beta
blockers. One of the 4 labetalol stereoisomers, the R,R-isomer dilevalol, had an
IC50 value half that of labetalol. CONCLUSIONS: Metabolites of verapamil,
gallopamil, carvedilol and omeprazole are characterized by having higher IC50
values (lower P-gp affinity) than the respective parent compounds. Only the
acebutolol metabolite, diacetolol, had a P-gp affinity comparable to that of the
parent compound.
PMID- 10783827
TI - Simultaneous measurement of cellular P-glycoprotein content and function by
multiparametric flow-cytometry.
AB - OBJECTIVE: A multiparametric approach was applied to simultaneously determine
expression and function of the drug efflux pump P-glycoprotein (PGP) in multidrug
resistant (MDR) human leukemic lymphoblast cell lines and isolated leukemic
blasts using flow-cytometry in a patient with acute myeloid leukemia (AML).
METHODS: The antigen was measured by staining PGP using the monoclonal antibody
4e3 which does not inhibit the function of PGP. The 4e3 antibody binds to an
external epitope of PGP and can therefore be used for staining living cells. Drug
transport, mediated by PGP, was determined simultaneously by measuring rhodamine
123 (rho123) efflux. The MDR cell lines, CEM/VLB10-2 and CEM/VBL100 are 10-fold
and 270-fold resistant to vinblastine (VBL), respectively, compared to the human
PGP-negative parent cell line CEM/WT and they express different amounts of PGP.
Initially, living cells were stained using the 4e3 antibody and a secondary
antibody labeled with 7-amino-4-methylcoumarin-3-acetic acid (AMCA). Cells were
then incubated for 60 min with rho123 (10 microM) and analyzed for rhodamine and
AMCA-derived fluorescence. The decrease in rho123 fluorescence was determined
after a further period of 30 min. RESULTS: CEM/VLB100 cells expressed larger
amounts of PGP, and rho123 fluorescence after 30 min was 85% lower than the
parent cell line. PGP expression and rho123 efflux were also detected in
CEM/VLB10-2 cells which display a low degree of resistance, thus reflecting the
high sensitivity of this method. PGP-expressing blasts and moderate rho123 efflux
were also observed in a specimen derived from a patient with clinically resistant
acute myeloid leukemia (AML). CONCLUSION: A multiparametric approach using flow
cytometry allows the reliable and sensitive measurement of both PGP expression
and function simultaneously in single cells.
PMID- 10783828
TI - Diverse effects of P-glycoprotein inhibitory agents on human leukemia cells
expressing the multidrug resistance protein (MRP).
AB - Multidrug resistance (MDR) to cancer chemotherapy is frequently associated with
decreased drug accumulation in cancer cells due to drug expulsion by multidrug
transporters such as P-glycoprotein (Pgp) and multidrug resistance protein (MRP).
The novel resistance modifying agents PSC 833, 280-446, and LY 335979 are
primarily targeted at inhibition of Pgp, and their MRP inhibitory potential is
largely unknown. OBJECTIVE: In the present study we addressed the effect of these
agents on MRP-derived drug resistance. MATERIALS: Drug-resistant human leukemia
cells with Pgp+/MRP- (KG1a/200, K562/150) and Pgp-/MRP+ (HL60/130) phenotypes
were maintained in suspension cultures for experimental studies of drug
accumulation and drug sensitization by Pgp inhibitors. METHODS: Intracellular
accumulation of the fluorescent anthracycline daunorubicin was measured by flow
cytometry and fluorescence detection. Daunorubicin dose-response curves were
generated by non-linear regression of electronically measured cell counts of 72-
96-h cultures. The half-maximal growth inhibitory dose (GI50) was used as
measure of growth inhibition. RESULTS: All MDR phenotypes studied exercised
significant resistance to daunorubicin. PSC 833, 280-446 and LY335979 were equal
in sensitizing Pgp+/MRP- cells to daunorubicin-induced growth inhibition (p <
0.0001). The Pgp-/MRP+ cells responded to PSC 833 and 280-446 by increased
accumulation of daunorubicin (p = 0.0022 and p = 0.0005, respectively) and
sensitization to the drug (p = 0.0009 and p = 0.0007, respectively). Conversely,
LY335979 did not affect accumulation of daunorubicin in Pgp-/MRP+ cells nor
sensitize these cells to daunorubicin. CONCLUSION: Pgp inhibitory agents have
differential effects on MRP-derived drug resistance which could be exploited in
treatment of multidrug resistance in cancer patients.
PMID- 10783829
TI - Resistance modulation in CHO cells by R-verapamil and bile salts is associated
with physical and chemical changes in the cell membrane.
AB - OBJECTIVES: Changes in multidrug resistance by resistance modifiers such as R
verapamil cause changes in fluidity of the cell membrane. The extent to which
these changes involve structural alterations in membrane lipids has been
investigated in CHO cells. METHODS: Sensitive (AUXB1) and resistant (CH(R)C5)
chinese hamster ovary cells (CHO) were grown in culture. Incubations were carried
out with R-verapamil (0-10 microM) or the membrane perturbing agents tauro-cheno
deoxycholate (0-1.6 mM, TCDC) and tauro-urso-deoxycholate (0-3.5mM, TUDC). Cell
membrane fluidity was determined by electron-paramagnetic resonance spectroscopy
and membrane lipids by HPLC and TLC. RESULTS: The resistant CH(R)C5 subline had a
higher cell membrane order (lower fluidity, S = 0.7234) in the interface region
of the cell membrane than sensitive AUXB1 cells (S = 0.6984) determined using
EPR. The MDR-modulator R-verapamil and TCDC, but not TUDC, lowered cell membrane
order in a concentration-dependent manner and increased membrane fluidity of the
resistant CH(R)C5 subline. TCDC and R-verapamil were without effect on the cell
membrane fluidity of AUXB1 cells. These changes were accompanied by alterations
in the fatty acid composition of the plasma membrane. Untreated sensitive AUXB1
cells had higher levels of unsaturated fatty acids than resistant CH(R)C5 cells.
In CH(R)C5 cells, R-verapamil increased the content of poly-unsaturated fatty
acids and TCDC, but not TUDC, increased the content of mono-unsaturated fatty
acids. CONCLUSIONS: The results demonstrate that resistance modifiers such as
verapamil may influence cytostatic drug action by producing structural changes to
lipid domains in the plasma membrane.
PMID- 10783830
TI - Cytostatic sensitivity and MDR in bladder carcinoma cells: implications for tumor
therapy.
AB - The clinical success generally seen in chemotherapy of advanced bladder carcinoma
is far from optimal. The mechanism of resistance development is unclear and the
expression of P-170 glycoprotein is generally low. The aim of this study, carried
out in vitro in sensitive and cisplatin-resistant cell lines, was to examine
sensitivity modulation using R-verapamil and cell membrane perturbing agents.
Cell growth rates and changes in the order of the cell membrane, determined using
electron-paramagnetic resonance spectrometry, were recorded. R-verapamil
increased the toxic effect of doxorubicin in the cisplatin-resistant cell line
which showed the highest membrane order. Linolenic acid had a similar effect and
also increased sensitivity to cisplatin and methotrexate. Bile salts (tauro-cheno
deoxycholate,TCDC, and tauro-urso-deoxycholate TUDC), had little effect on
cytotoxicity. These results indicate that R-verapamil and linolenic acid can act
as sensitivity modulators in bladder carcinoma cells and that the action of these
agents may involve membrane fluidity changes, a phenomenon noted previously in
regard to sensitivity modulation in chinese hamster ovary cell lines.
PMID- 10783831
TI - Modulation of multidrug resistance in human leukemia cells with mdr1-targeted
antisense oligonucleotides using variable treatment schedules.
AB - OBJECTIVE: The purpose of the current study was to characterize the effect of
chimeric AS-ODNs encapsulated with cationic lipids on MDR in human leukemia cells
and to determine if this modification of the ODN alone or in combination with the
cationic lipid might offer advantages over classical ODN treatment with free
unmodulated or phosphorothiolated AS-ODNs. Furthermore, we extended the antisense
method to the use of AS-ODNs in the parental drug-sensitive leukemia cells which
express mdr1-mRNA at a relative low level and lack P170 expression to evaluate
the effectiveness of prophylactic AS-ODN treatment. METHODS: The effect of a 4
day AS-ODN treatment in drug-resistant human leukemia cells which exhibit the
classic MDR phenotype at a moderate level was examined. Twenty-four hours after
the last ODN administration the cells were analyzed for mdr1-mRNA (quantitative
RT-PCR) and P170 expression (FCM), for R123 accumulation/efflux capacity (FCM)
and for sensitivity to vincristine (MTT). In the parental drug-sensitive CCRF-CEM
cells the mdr1-mRNA expression was assessed 24, 48 and 72 h after AS-ODN
treatment administered as free phosphorothioate or conjugated with DMRIE-C.
RESULTS: Cationic lipids produced a clear increase in cellular ODN uptake but
also caused an increase in variability of uptake rates (30% vs. 10% variability
after free phosphorothioates). Both AS-ODNs inhibit P170 expression whereby the
antisense effect of the chimeric ODN seems to be stronger compared to the
phosphorothioate (30% vs. 22% MRK16 staining). Consistent with the inhibition of
P170 expression, an increased sensitivity to vincristine was observed. In
parental drug-sensitive cells, AS-ODN treatment caused nearly complete inhibition
of mdr1-mRNA expression (5% of control). CONCLUSION: The data demonstrate that it
is nearly impossible to achieve a complete reversal of the MDR phenotype in drug
resistant cells using AS-ODNs. A more promising approach seems to be the
prophylactic treatment with AS-ODNs.
PMID- 10783832
TI - Induction of apoptosis by idarubicin: how important is the plasma peak?
AB - OBJECTIVES: It is still not clear whether a high plasma peak or a prolonged
plasma presence of the drug is optimal for chemotherapy with anthracyclines. A
high plasma peak seems to correlate with the liberation of oxygen radicals and
cumulative delayed cardiotoxicity, and therefore, should be avoided. On the other
hand, its role in attaining the desired therapeutic effect, i.e. induction of
apoptosis in tumor cells, has not been clearly elucidated. METHODS: Idarubicin is
the only anthracycline that can be applied orally. We measured the DNA-binding of
idarubicin and idarubicinol and the induced apoptosis in the human promyelocytic
HL-60 leukemia cell line. Various pharmacokinetic profiles, with and without
clinically relevant peak concentrations, were simulated in vitro. RESULTS: The
concentration necessary for maximal DNA-binding and subsequent induction of
apoptosis was 1.5 microg/ml for 20 minutes which is well above the plasma
concentration achievable in therapy. A plateau of apoptosis was observed after 90
minutes of incubation; a prolongation above 90 minutes did not increase the rate
of apoptosis. We simulated a bolus application and a continuous infusion using
two different pharmacokinetic profiles of idarubicin with comparable AUCs (area
under the time curve). After 48 hours of total incubation, the viability of HL-60
cells was 56.88% with profile 1 (50 ng/ml idarubicin for 2 hours) and 83.00% with
profile 2 (4.25 ng/ml for 24 hours). CONCLUSIONS: Although these in vitro
experiments are not directly applicable to the clinical situation, they do
indicate that a prolongation of the application time up to at least 90 minutes,
either by continuous infusion or by oral application, may be acceptable as a
method of increasing apoptosis. On the other hand, the plasma peak seems to be an
important factor for the induction of apoptosis. Further studies are in progress
to define the minimal plasma peak necessary to induce a maximum of apoptosis.
PMID- 10783833
TI - Risk factors for drug-induced gingival overgrowth.
AB - BACKGROUND/AIMS: Drug-induced gingival overgrowth remains a significant problem
for the periodontologist. Many patients medicated with the drugs implicated in
this unwanted effect experience significant, recurrent gingival problems that
require repeated surgical excisions. In this review, we attempt to identify and
quantify the various "risk factors" associated with both the development and
expression of the drug-induced gingival changes. METHOD: The risk factors
appraised include age, sex, drug variables, concomitant medication, periodontal
variables and genetic factors. Elucidation of such factors may help to identify
"at risk patients" and then develop appropriate treatment strategies. RESULTS: Of
the factors identified, the only one that can be affected by the periodontologist
is the patents' periodontal condition. However, drug variables and concomitant
medication do impact upon the expression of gingival overgrowth. CONCLUSION: The
identification of risk factors associated with both the prevalence and severity
of drug-induced gingival overgrowth is important for all parties involved with
this unwanted effect. Both periodontologist and patient have an important role to
play in improving oral hygiene and gingival health. Likewise, there is always an
opportunity to establish a close liaison between the patient's physician and the
periodontologist to try and identify alternative drug regimens that can help
reduce the impact of this unwanted effect.
PMID- 10783834
TI - Radiographic detection and assessment of the periodontal endosseous defects.
AB - AIMS: The aim of the present study was to investigate the potential of
conventional radiography in detecting and accurately imaging periodontal
endosseous (or osseous) defects when compared to surgical measurements. A further
objective of the study was the selection of the most successful radiographic
method for the assessment of endosseous defects. METHOD: Surgical measurements,
during periodontal flap surgery, and radiographic measurements, from periapical
and panoramic radiographs, were obtained from 5,072 proximal surfaces of 100
patients presenting with periodontitis. RESULTS: Statistical evaluation of the
surgical and radiographic measurements revealed the following. (1) The ability of
the radiographs to detect periodontal osseous defects was relatively low. (2) For
periapical radiography, it depended, in descending order, on the depth and
buccolingual width of the defect, the number of osseous walls and the jaw
location. For panoramic radiography, it depended only on buccolingual width. (3)
Osseous defects of small depth and/or small buccolingual width were the most
difficult to detect radiographically. (4) Periapical radiography was more
successful than panoramic in detecting osseous defects, and more accurate in
assessing the defect dimensions (depth, mesiodistal width). (5) The difference in
the defect detection ability between the 2 radiographic methods, the accuracy of
the radiographic defect dimensions assessment as well as the degree of agreement
between periapical and panoramic assessment depended on defect location and
dimensions. CONCLUSIONS: Periapical radiography is superior to panoramic in
detecting and accurately imaging periodontal osseous destruction.
PMID- 10783835
TI - Dental and periodontal status of Sjogren's syndrome.
AB - BACKGROUND: Sjogren's syndrome (SS) is one of the most common systemic autoimmune
diseases in middle-aged women. The present study had the aim to examine the
dental and periodontal condition in patients with SS in comparison with disease
controls and to evaluate the influence of reduced salivary flow in the
periodontal tissues. METHOD: We examined 24 patients with primary or secondary SS
in comparison with 27 patients who had another autoimmune disease but no signs or
symptoms of SS, as well as with 29 subjects who had a subjective feeling of
xerostomia or xerophthalmia without exhibiting an underlying disease. The
clinical evaluation included examination of the oral mucosa, determination of
missing, decayed and filled teeth, fixed or removable prosthetic appliances,
plaque index, gingival index, probing pocket depth, probing attachment level,
oral hygiene habits and frequency of dental visits. Statistical analysis was
performed using the 2-tailed Fisher exact and Kruskal-Wallis tests. RESULTS: No
significant difference was found in the dental or periodontal condition of the 3
groups. The number of teeth, feelings and distal or mesial decay lesions
correlated negatively with age, while the number of fixed prosthetic appliances
correlated positively. The salivary flow was statistically lower in patients with
SS and exhibited a negative correlation with the number of cervical decay
lesions. It was also found that SS patients had better oral hygiene habits than
subjects of the control groups. CONCLUSIONS: No significant,difference could be
detected concerning the dental and periodontal status of SS patients, compared
with that of patients with other immune diseases as well as with that of controls
who had subjective xerostomia.
PMID- 10783836
TI - Laser Doppler flowmeter measurement of relative gingival and forehead skin blood
flow in light and heavy smokers during and after smoking.
AB - AIM: To determine the effect of the smoking experience on relative blood flow in
gingiva and to compare this to skin. METHOD: A laser Doppler flowmeter was used
to record relative blood flow to healthy gingiva and to forehead skin in smokers
and non-smoking controls. Smoking status was verified by quantitative analysis of
serum cotinine. Continuous measurements were made over sequential periods with
the subject at rest, during a sham smoking exercise, during smoking of a standard
research cigarette (2R1, University of Kentucky) for 5 min and throughout a
subsequent recovery period. Non-smoking controls sham smoked during the
equivalent 5 minute smoking period. RESULTS: No significant differences with
respect to the proportional changes of relative gingival blood flow between time
points were observed between the groups. However, between-group comparisons of
relative blood flow revealed a significant increase in the relative blood flow to
the forehead skin of light smokers (serum cotinine < or =60 ng/ml; n=6), when
compared to heavy smokers (serum cotinine > or = 100 ng/ml; n=9) or to non
smokers (serum cotinine < or = 10 ng/ml; n=6), 2 min following the smoking
experience (p = 0.007). CONCLUSION: The results do not seem to support the theory
that tobacco smoking causes localised vasoconstriction in the periodontal tissues
in humans. These data show that smoking causes an acute increase in relative
blood flow in forehead skin in light smokers compared to heavy smokers,
suggesting a potential induction of tolerance in regular users of tobacco.
PMID- 10783837
TI - Subgingival polishing with a teflon-coated sonic scaler insert in comparison to
conventional instruments as assessed on extracted teeth. (I) Residual deposits.
AB - BACKGROUND: Recent studies have shown that endotoxins are located on the
periodontally diseased root cementum and not within it. These studies led to the
suggestion that the root surface could be treated less aggressively during
periodontal therapy. Thus, we designed a teflon-tubed sonic scaler insert for
subgingival polishing. It was our objective to assess to which extent this new
instrument is capable of removing bacterial deposits in deep pockets in
comparison with conventional scaling instruments. METHOD: We compared the extent
to which plaque and calculus could be removed with a curette, a conventional
sonic and ultrasonic scaler insert, a Per-io-tor insert, and a teflon-tubed sonic
scaler insert. 84 teeth requiring extraction had been treated with one of these
instruments. After extraction, the teeth were stained with Malachite green, and
the following areas were assessed: area lacking plaque and calculus, calculus,
and area only covered with plaque. For statistical comparison, nonparametric
analyses were carried out. RESULTS: Curettes and conventional ultrasonic and
sonic-scaler inserts had more area lacking plaque and calculus (97.5%, 92.2%,
92.1%) than did the Per-io-tor (80.1%) or the teflon-coated sonic scaler insert
(84.4%). A similar effectivity sequence was observed for residual soft deposits
(curette: 1.9%, ultrasonic scaler: 6.1%, sonic scaler: 5.4%, teflon-coated sonic
scaler: 5.1% and Per-io-tor: 9.5%). CONCLUSIONS: The Per-io-tor and the teflon
coated sonic scaler insert seem to be suitable for the removal of soft deposits
on the root surface, but not for the removal of calculus.
PMID- 10783838
TI - Smoking and GCF levels of IL-1beta and IL-1ra in periodontal disease.
AB - AIMS: GCF levels of the cytokine IL-1beta and its receptor antagonist IL-1ra were
analyzed with respect to smoking in patients with moderate to severe periodontal
disease. The study population included 22 smokers and 18 non-smokers in the age
range 32-86 years. Concomitantly, the GCF levels of IgA, IgG, albumin and total
protein were analyzed. METHOD: Samples of GCF were obtained from 2 diseased sites
in each patient by means of an aspiration method. IL-1beta, IL-1ra, IgA and IgG
were determined with immunoelectrophoresis. Total protein was determined by the
BCA method. RESULTS: The clinical characteristics in terms of probing depth and
frequency of diseased sites and supragingival plaque did not differ between
smokers and non-smokers. Gingival bleeding, however, was significantly depressed
in smokers. IL-1beta was detected in GCF of 95% of both smokers and non-smokers
and IL-1ra in all patients. The GCF level of IL-1ra was approximately 1,000-fold
that of IL-1beta. The GCF levels of IL-1beta and IL-1ra were high in comparison
with those of TNF-alpha and IL-6 determined by the same method in our earlier
studies. CONCLUSION: Our observations did not reveal any influence of smoking on
the levels of IL-1beta and IL-1ra in GCF.
PMID- 10783839
TI - Determination of the in situ bactericidal activity of an essential oil mouthrinse
using a vital stain method.
AB - BACKGROUND: Recent research has indicated that bacteria within a biofilm may
undergo changes in susceptibility to antimicrobial agents when compared to
planktonic forms. This study was conducted to determine the bactericidal effect
of an essential oil-containing mouthrinse (Listerine Antiseptic) on dental plaque
bacteria in situ. METHODS: 1-day-old plaque in 17 subjects was sampled at
baseline from the buccal surfaces of diagonally contralateral maxillary and
mandibular bicuspids and 1st molars. Subjects were then randomly assigned either
an essential oil mouthrinse or a sterile saline negative control and rinsed under
supervision with 20 ml for 30 s. 30 min later, plaque was sampled from the
remaining contralateral posterior teeth. Subjects repeated these procedures with
their respective alternate rinse after 1 week. Pooled plaque samples from each
subject at each sampling period were stained with a commercially-available
fluorescent stain which fluoresces live and dead bacteria green and red,
respectively. The stained plaque specimens were analyzed using computerized image
analysis. A separate in vitro study was conducted to determine the relationship
between the % red stain per sample and bacterial viability. RESULTS: Analysis of
vital stained plaque specimens indicated that following rinsing with the
essential oil mouthrinse, 78.7% of bacteria were dead compared to 27.9% following
rinsing with the negative control (p<0.001). The in vitro findings demonstrated
that the % red stain per sample is reflective of actual bacterial kill.
CONCLUSIONS: This study confirms the findings of previous in vitro and in vivo
studies which demonstrated the essential oil mouthrinse to have significant
biocidal activity against oral micro-organisms. These studies all support the
primacy of a bactericidal mechanism in producing the plaque and gingivitis
reductions observed in numerous clinical trials conducted on the essential oil
mouthrinse.
PMID- 10783840
TI - Relationship of the substance P to indicators of host response in human gingival
crevicular fluid.
AB - BACKGROUND: The substance P (SP) level in human gingival crevicular fluid (GCF)
was studied in relation to clinical periodontal variables and to various
indicators of host response in the GCF. METHODS: GCF was collected from
periodontal sites with gingival inflammation and shallow or moderately deep
pocket in 48 subjects. The total amount of SP and the substances based on host
response factors in a 30-s sample were determined by ELISA and enzymatic methods.
RESULTS: Significant correlation was found between SP and probing depth (r=
0.637, p<0.001), while correlation was weak between SP and either gingival (r=
0.177, p=0.23) or plaque index (r=0.008, p=0.96). SP also showed significant
correlation with the indicators of host response: prostaglandin E2, aspartate
aminotransferase, alkaline phosphatase, myeloperoxidase, interleukin-1beta, tumor
necrosis factor-alpha, interleukin-8 and monocyte chemoattractant protein-1
(r=0.434-0.867, p<0.01-0.001). CONCLUSION: These results indicate that
neuropeptide SP in GCF may have a potential as an indicator of periodontal
inflammation and the host response.
PMID- 10783841
TI - Is there a relationship between rheumatoid arthritis and periodontal disease?
AB - AIM: The aim of this study was to determine whether there is a relationship
between disease experience of rheumatoid arthritis and periodontal disease.
METHODS: 1,412 individuals attending the University of Queensland's School of
Dentistry were assessed for the prevalence of periodontal disease and rheumatoid
arthritis. Analysis of data obtained from a self-reported health questionnaire
and dental records was carried out and included: number of individuals referred
for advanced periodontal care (test group); number of individuals attending for
routine dentistry; determination of rheumatoid arthritis, cardiovascular disease
and diabetes mellitus through self-reporting and assessment of prescription
medications; assessment of periodontal disease through assessment of existing
oral radiographs. RESULTS: In patients referred for periodontal treatment, the
prevalence of self-reported rheumatoid arthritis was 3.95% which is significantly
higher than that seen in patients not referred for periodontal treatment (0.66%)
and also that reported in the general population (1%). Of those referred patients
with rheumatoid arthritis, 62.5% had advanced forms of periodontal disease. These
results were mirrored in the results of the self-reported prevalence of
cardiovascular disease and diabetes mellitus which was consistent with the
published higher prevalence in periodontal patients. CONCLUSIONS: Based on data
derived from self-reported health conditions, and not withstanding the
limitations of such a study, we conclude that there is good evidence to suggest
that individuals with moderate to severe periodontal disease are at higher risk
of suffering from rheumatoid arthritis and vice versa.
PMID- 10783842
TI - A controlled study of relative periodontal attachment loss in people with HIV
infection.
AB - OBJECTIVE: To compare the progression of periodontal destruction in people with
and without HIV. METHOD: Relative attachment loss on 6 index teeth was compared
between 19 people with HIV and 17 people without HIV infection over 12 and 18
month follow ups. RESULTS: The proportions of sites with 1, 2 or 3 mm of relative
attachment loss were similar in the study and control groups. Mean maximum
relative attachment loss was similar in both groups after 12 months but greater
in the study group after 18 months. CONCLUSIONS: The data are not compelling
evidence of greater periodontal destruction associated with HIV infection. Large
scale cohort studies or meta-analyses would be more conclusive.
PMID- 10783843
TI - A laboratory and clinical investigation comparing 2 oscillating/rotating electric
toothbrushes.
AB - BACKGROUND/AIMS: The purpose of the study was to investigate the efficacy of
plaque removal by 2 different toothbrushes in a laboratory model and in a
clinical study. METHOD: The 2 brushes used were the Philips/Jordan HP 735 and the
Braun Oral-B Ultra Plaque Remover (D9). Both were compared in a laboratory study
(using a robot system) and a short-term clinical study. For the laboratory study,
plaque substitute was applied to the artificial teeth of ten typodonts, which
were cleaned by a robot for 2 min. The remaining plaque substitute was measured
on buccal and lingual/palatal surfaces, as well as gumline and interproximal
sites, using a computerized vision system. The clinical study included 23 non
dental students. All subjects received a single oral prophylaxis and were asked
not to brush their teeth for 48 h prior to their appointment. After the amount of
plaque had been evaluated at 6 sites per tooth, subjects brushed in a random
split-mouth order with the 2 electric toothbrushes, after which the amount of
plaque was re-evaluated. RESULTS: The results of the laboratory study showed
that, for all surfaces combined, the mean removal of plaque substitute for both
brushes was the same. However, at the vestibular and the approximal vestibular
surfaces, the reduction in plaque substitute was significantly higher (p<0.01)
with the Braun toothbrush compared to the Philips. In the clinical study, the
mean overall plaque reduction for the Braun toothbrush (74%) was significantly
higher than for the Philips (66%). Further analysis revealed that the significant
difference in favour of the Braun brush was mainly due to plaque removal from the
approximal vestibular and the approximal lingual sites. CONCLUSIONS: In
conclusion, both the laboratory and clinical study show that the Braun Oral-B
Ultra Plaque Remover (D9) is more effective than the Philips/Jordan HP 735. Both
study models indicate that this difference is greatest on the approximal
vestibular surfaces.
PMID- 10783844
TI - Calcium paradox disease: calcium deficiency prompting secondary
hyperparathyroidism and cellular calcium overload.
PMID- 10783845
TI - Trends in the incidence of hip fracture in Japan, 1987-1997: the third nationwide
survey.
AB - The third nationwide survey for hip fracture incidence was conducted in 1997
following the first such survey in 1987 and the second in 1992. The purpose of
this study was to investigate the trends in the incidence and regional
distribution of this disease during 10 years. Of 10271 orthopedic institutions in
Japan, 4503 were selected as subjects for the study using the optimum allocation
method. Questionnaires concerning new patients with hip fracture were mailed. The
replies were obtained from 2930 institutions by the end of December 1998; the
response rate was 65.1%. The number of new patients was estimated to be 89900
94900 [mean, 92400; 20100-21400 (20800) men and 69600-73600 (71600) women]. The
number of cases in 1997 was about 1.7 times higher than that in the first survey
and 1.2 times higher than that in the second survey. The age-specific incidence
(per 10000 per year) in men and women in 1997 was 0.30 and 0.13, respectively,
for age under 40 years; 0.91 and 0.60, 40-49 years; 2.00 and 2.39, 50-59 years;
5.12 and 9.07, 60-69 years; 17.3 and 40.8, 70-79 years; 57.4 and 147.8, 80-89
years; and 128.9 and 281.0, for age over 90 years. The incidence was increased
compared with that of the first survey, and similar to the second survey,
excepting that of women aged 80 years or older. Concerning regional differences,
hip fracture incidence was relatively low in the eastern area compared to the
western area in Japan, which was a trend identical to that in the previous
nationwide surveys.
PMID- 10783846
TI - Patterns of gene expression associated with BMP-2-induced osteoblast and
adipocyte differentiation of mesenchymal progenitor cell 3T3-F442A.
AB - The pluripotent mesenchymal stem cells give rise to osteoblasts, adipocytes,
chondrocytes, and myoblasts. The differentiation of these stem cells into each of
the mature functional cells may be controlled by a distinctive master gene(s) and
is associated with temporal and spatial expression of diverse genes.
Identification of genes that are expressed during the differentiation of the
mesenchymal cells to osteoblasts is, therefore, important to obtain insights into
the molecular mechanisms of osteogenesis. The murine undifferentiated mesenchymal
cell 3T3-F442A, when treated with the bone morphogenetic protein 2 (BMP-2), a
well-characterized inducer of mesenchymal cell differentiation, exhibited both
osteoblastic and adipocytic differentiation. Using the SAGE (serial analysis of
gene expression) technique, which has been shown to enable quantitative analysis
of large numbers of genes in a simple and quick manner, we obtained 1600 sequence
tags representing 2107 individual nucleotide sequences from control and BMP-2
treated 3T3-F442A cells, respectively. By comparing the frequency of tag
occurrence, we found profiles of up- or downregulated genes associated with
osteoblast or adipocyte phenotype such as type I collagen, osteonectin and OSF-2,
or C/EBPbeta, aP2, fatty acid synthase, and lipoprotein lipase, respectively, in
BMP-2-treated 3T3-F442A cells. Our data show that BMP-2 induces not only
osteoblastic but also adipocytic differentiation in the 3T3-F442A cells. They
also show that the 3T3-F442A cells have bipotentials of differentiating toward
osteoblasts and adipocytes. The results, therefore, might explain the inverse
correlation between trabecular bone volume and fat volume in the bone marrow
cavity. The results also suggest that the SAGE may be a useful technique that
allows us a fast and efficient way to generate global and local views of gene
expression associated with cellular differentiation of the mesenchymal stem
cells.
PMID- 10783847
TI - Ultrastructural study on calcification of cartilage: comparing ICR and twy mice.
AB - Twy mice are autosomal recessive mutant mice that develop multiple progressive
abnormal calcification, mainly of the cartilage or tendons of the spine and
limbs. They finally succumb to severe deformation and ankylosis. We carried out
an ultrastructural study on the growth plate as well as the articular and spinal
disc cartilage of twy mice and control ICR mice. Knee and spinal specimens were
obtained from the animals, then prepared using standard procedures.
Ultrastructural observations were made on uranyl lead-stained sections and
elemental analysis was carried out on unstained sections. In both twy and ICR
mice, linked granules (chain granules) were observed at the pericellular matrix,
but there was no remarkable difference between their presence in the growth
cartilage. In the twy mice, however, chain granules were observed in the
pericellular matrix, cytoplasm, and nucleus of the articular and spinal disc
cartilage. These chain granules disappeared after decalcification. Elemental
analyses revealed significant amounts of calcium and phosphorus in these
granules. It may be significant for abnormal calcification that such chain
granules were observed in the articular and spinal disc cartilage of twy mice.
PMID- 10783848
TI - Osteoclastic resorption of equine cranial and postcranial bone in vitro.
AB - To address possible differences in the resorbability of cranial and postcranial
bone, slices of equine frontal bone and leg (first phalanx or third metacarpus)
were seeded with embryonic chick bone cells and cultured for 20-24h. After
removing the cells and drying the specimens, the areas and volumes of more than
800 resorption pits in each set were measured using a video-rate reflection
confocal microscope system. Relative mineralization densities were determined by
quantitative electron backscattering analysis. The mean mineralization density
was greater in the leg bone, but the mean depths for resorption pits in frontal
bone were smaller (median volume/area ratios, experiment 1 and experiment 2: 1.98
microm frontal and 3.79 microm leg versus 2.70 microm and 4.20 microm,
respectively; P < 0.0001, Mann-Whitney), even though the areas were greater in
the frontal (medians, 286 microm2 and 324 microm2, versus 242 microm2 and 201
microm2; P < 0.0001). This study has shown a difference between cranial and
postcranial equine bone in the shape and size of resorption pits formed in vitro.
Overall, it has shown that cranial bone may be resorbed at least as readily as
postcranial bone. This result is counter to the clinical impression that cranial
bone has a greater staying power than postcranial bone when used as a grafting
material.
PMID- 10783849
TI - Identification of a novel polymorphism of estrogen receptor-alpha gene that is
associated with calcium excretion in urine.
AB - A novel variation of the estrogen receptor-alpha (ERalpha) gene was identified by
polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP).
It is one base substitution in codon 325 (CCC [allele M] to CCG [allele m]) in
exon 4 of the human ERalpha gene. This substitution did not cause an amino acid
change. We categorized 306 unrelated Japanese postmenopausal women into three
genotypes: MM, Mm, and mm; the frequency of each genotype was 26.5%, 43.1%, and
30.4%, respectively. Then, the association of this polymorphism with bone mineral
density (BMD) of lumbar spine and bone-calcium metabolic markers was studied.
There was no significant difference in BMD of the lumbar spine or most of the
bone metabolic markers. However, the urinary calcium (Ca) excretion ratio (u
Ca/Cre) corrected by creatinine was significantly lower in the genotype mm group
compared with the genotype MM group (MM vs mm, 0.247 +/-0.158 vs 0.200 +/- 0.105;
P < 0.05). We examined the relationship of restriction fragment length
polymorphisms (RFLPs) (PvuII, XbaI) in intron 1 and the polymorphism in exon 4.
The frequency of genotype MM was higher in the genotype PPxx, which was reported
to be associated with lower BMD in the same population of Japanese postmenopausal
women. The ER polymorphism identified in this study might be related to some
biological mechanisms that regulate calcium metabolism.
PMID- 10783850
TI - Comparison of various biochemical measurements with bone mineral densitometry and
quantitative ultrasound for the assessment of vertebral fracture.
AB - We have retrospectively studied postmenopausal elderly Japanese women (n = 288;
age range, 60-75 years, 65.8 +/- 4.5 [mean +/- SD]) for the evaluation of
biochemical measurements in assessment of bone mass and vertebral fracture,
comparing with several bone mineral measurements and quantitative ultrasound
(QUS) measurement. Several biochemical parameters [red cell count (RBC),
hemoglobin (HB), albumin (ALB), and cholesterol (CHO)] positively correlated with
bone mass parameters, but only serum cholesterol showed association with the
presence of vertebral fracture. Urinary deoxypyridinoline (DPYD) and n
telopeptide (NTx) showed moderate negative correlation with bone mass parameters,
and DPYD showed association with vertebral fracture. All bone mineral
measurements (lumbar spine, total body, femoral neck by DXA, calcaneal bone by
SXA, distal radius by pQCT) and QUS measurement (os calcaneus by two different
QUS machines) showed a higher odds ratio and high chi2 value in logistic
regression analysis for association with vertebral fracture. Thus, bone mass
measurement is the principal method for assessment of fracture risk, and
biochemical measurement should be used for motivation of further bone mass
measurement. In biochemical measurements, measurement of serum cholesterol is
cheap and easy, and thus might have an advantage, although further study is
necessary.
PMID- 10783851
TI - Increase of intestinal calcium absorption and bone mineral density by heated
algal ingredient (HAI) in rats.
AB - Active absorbable calcium (AAACa) produced by adding HAI (heated algal
ingredient) to oyster shell calcium (AACa) is quite efficiently absorbed from the
intestine and can increase bone mineral density in elderly osteoporotic patients.
HAI was produced by heating the seaweed Cystophyllum fusiforme under reduced
pressure, extracting with 6N HCL, and partially neutralizing it. Butanol-ethanol
extraction then yielded active HAI fraction A, corresponding to about 1% in
weight. The active HAI fraction increased intestinal Ca absorption as shown by a
dose-dependent increase of plasma Ca in young male parathyroidectomized rats
maintained on a low-Ca diet by administration through a stomach tube with a
constant dose of AACa. The action of the active fraction A to maintain bone mass
was then tested in young male rats kept on a low-Ca diet for 2 weeks. Bone
weight, trabecular bone density, and strength-strain index as indices of bone
strength measured by peripheral computed tomography (pQCT) tended to increase
when the active HAI fraction was given along with Ca. HAI increased intestinal Ca
absorption and prevented the decrease of bone density in rats kept on a low-Ca
diet.
PMID- 10783852
TI - The relationship between spinal and appendicular bone mass modified by physical,
historical, and lifestyle factors.
AB - Spinal, radial, and calcaneal bone mineral density (BMD) measured by dual-energy
X-ray absorptiometry (DXA) and calcaneal bone mass measured by quantitative
ultrasound densitometry (QUS) were compared in 83 healthy Japanese female
volunteers. A significant and strong correlation was found within the same
methods (r = 0.619 for lumbar spine and radius by DXA, r = 0.760 for lumbar spine
and calcaneus by DXA, and r = 0.644 for calcaneus and radius by DXA), and within
the same site (r = 0.758 for calcaneus by DXA and QUS). A lesser correlation was
found when both the method and site were different (r = 0.521 for radius by DXA
and calcaneus by QUS, and r = 0.583 for lumbar spine by DXA and calcaneus by
QUS). Relations of spinal and appendicular bone mass were examined together with
physical, historical, and lifestyle factors. Multiple correlation coefficients
between bone mass at the lumbar spine and appendicular bone were 0.754 to 0.782,
and all these increased after modification by physical, historical, and lifestyle
factors in whichever appendicular bone. In the correlation between lumbar spine
and radial BMD, past weight-bearing activity, age at menarche, family history of
fractures, and body weight were chosen. Menstrual status, body weight, past
weight-bearing activity, and present arm-using activity were chosen to determine
the correlation between lumbar spine BMD and calcaneal bone mass by QUS. These
results suggest that the incorporation of those factors improved the correlation
between lumbar spine BMD and appendicular bone mass, especially in cases of
lumbar spine BMD versus radial BMD or calcaneal bone mass by QUS.
PMID- 10783854
TI - Framework lives, but does it learn?
PMID- 10783853
TI - Critics of 'gene foods' report are avoiding the real issues.
PMID- 10783855
TI - Critics challenge Celera's claims over human genome sequence...as biotech debate
splits along party lines.
PMID- 10783856
TI - US academy study finds GM foods are safe...but critics claim the panel was
biased.
PMID- 10783857
TI - Music software to come to genome aid?
PMID- 10783858
TI - Frustration grows over EU grant application procedures.
PMID- 10783859
TI - Deaths bring South African HIV drug trials to a premature halt.
PMID- 10783860
TI - Fake bird fossil highlights the problem of illegal trading.
PMID- 10783861
TI - Affymetrix loses first round of patent battle.
PMID- 10783862
TI - Storming the Tower of Babel.
PMID- 10783863
TI - Technology failures were caused by managers not listening to engineers.
PMID- 10783864
TI - No conflict between SLAC and Japan's KEK. Stanford Linear Accelerator Center
PMID- 10783865
TI - Venture funding for new ideas
PMID- 10783866
TI - Regenesis
PMID- 10783867
TI - Perfect use of imperfection.
PMID- 10783868
TI - Chaos in space and time
PMID- 10783869
TI - Plant biology. Shattering developments.
PMID- 10783870
TI - High-temperature superconductivity. Stripes defeat the Fermi liquid
PMID- 10783871
TI - Recognizing DNA in the library.
PMID- 10783872
TI - Freezing by heating
PMID- 10783873
TI - Immunology. Commit ye helpers.
PMID- 10783874
TI - Delaying the onset of Huntington's in mice.
PMID- 10783875
TI - Hexadecane decay by methanogenesis.
PMID- 10783876
TI - Parasitic honeybees get royal treatment.
PMID- 10783877
TI - Specificities of heparan sulphate proteoglycans in developmental processes.
AB - Heparan sulphate proteoglycans are abundant cell-surface molecules that consist
of a protein core to which heparan sulphate glycosaminoglycan chains are
attached. The functions of these molecules have remained mostly underappreciated
by developmental biologists; however, the actions of important signalling
molecules, for example Wnt and Hedgehog, depend on them. To understand both the
mechanisms by which ligands involved in development interact with their receptors
and how morphogens pattern tissues, biologists need to consider the functions of
heparan sulphate proteoglycans in signalling and developmental patterning.
PMID- 10783878
TI - One-dimensional nature of the magnetic fluctuations in YBa2Cu3O6.6
AB - There is increasing evidence that inhomogeneous distributions of charge and spin-
so-called 'striped phases'--play an important role in determining the properties
of the high-temperature superconductors. For example, recent neutron-scattering
measurements on the YBa2Cu3O(7-x) family of materials show both spin and charge
fluctuations that are consistent with the striped-phase picture. But the
fluctuations associated with a striped phase are expected to be one-dimensional,
whereas the magnetic fluctuations observed to date appear to display two
dimensional symmetry. We show here that this apparent two-dimensionality results
from measurements on twinned crystals, and that similar measurements on
substantially detwinned crystals of YBa2Cu3O6.6 reveal the one-dimensional
character of the magnetic fluctuations, thus greatly strengthening the striped
phase interpretation. Moreover, our results also suggest that superconductivity
originates in charge stripes that extend along the b crystal axis, where the
superfluid density is found to be substantially larger than for the a direction.
PMID- 10783879
TI - Magnetic field surrounding the starburst nucleus of the galaxy M82 from polarized
dust emission
AB - Magnetic fields may play an important role in the star-formation process,
especially in the central regions of 'starburst' galaxies where star formation is
vigorous. But the field directions are very difficult to determine in the dense
molecular gas out of which the stars form, so it has hitherto been impossible to
test this hypothesis. Dust grains in interstellar clouds tend to be magnetically
aligned, and it is possible to determine the alignment direction based on the
polarization of optical light due to preferential extinction along the long axes
of the aligned grains. This technique works, however, only for diffuse gas, not
for the dense molecular gas. Here we report observations of polarized thermal
emission from the aligned dust grains in the central region of M82, which
directly traces the magnetic field structure (as projected onto the plane of the
sky). Organized field lines are seen around the brightest star-forming regions,
while in the dusty halo the field lines form a giant magnetic bubble possibly
blown out by the galaxy's 'superwind'.
PMID- 10783880
TI - Mechanisms of extensive spatiotemporal chaos in Rayleigh-Benard convection
AB - Spatially extended dynamical systems exhibit complex behaviour in both space and
time--spatiotemporal chaos. Analysis of dynamical quantities (such as fractal
dimensions and Lyapunov exponents) has provided insights into low-dimensional
systems; but it has proven more difficult to understand spatiotemporal chaos in
high-dimensional systems, despite abundant data describing its statistical
properties. Initial attempts have been made to extend the dynamical approach to
higher-dimensional systems, demonstrating numerically that the spatiotemporal
chaos in several simple models is extensive (the number of dynamical degrees of
freedom scales with the system volume). Here we report a computational
investigation of a phenomenon found in nature, 'spiral defect' chaos in Rayleigh
Benard convection, in which we find that the spatiotemporal chaos in this state
is extensive and characterized by about a hundred dynamical degrees of freedom.
By studying the detailed space-time evolution of the dynamical degrees of
freedom, we find that the mechanism for the generation of chaotic disorder is
spatially and temporally localized to events associated with the creation and
annihilation of defects.
PMID- 10783881
TI - Phase transitions in the incoherent lattice fluctuations in YBa2Cu3O(7-delta)
AB - The growing body of experimental evidence for the existence of complex textures
of charges and spins in the high-temperature superconductors has drawn attention
to the so-called 'stripe-phase' models as a possible basis for the mechanism of
superconductivity in these materials. Such observations have until now been
restricted to systems where the texture dynamics are slow or suppressed
altogether, and do not include the important case of YBa2Cu3O(7-delta). It seems
likely that the dynamic behaviour of stripes, which has been suggested to undergo
several phase transitions as a function of temperature, should also be reflected
in the lattice properties of the host materials, and this forms the motivation
for our present experiments. Specifically, we use MeV helium ion channelling, an
ultrafast real-space probe of atomic displacements (with sub-picometre
resolution), to probe incoherent lattice fluctuations in YBa2Cu3O(7-delta) as a
function of temperature and oxygen doping. We detect lattice fluctuations that
are larger than the expected thermal vibration component, and which show
anomalies characteristic of the phase transitions anticipated for a dynamic
stripe phase. Comparison of our lattice results with single-particle-tunnelling
and photoemission data highlights the importance of spin-charge separation
phenomena in the copper oxide superconductors.
PMID- 10783882
TI - Complete photonic bandgaps in 12-fold symmetric quasicrystals
AB - Photonic crystals are attracting current interest for a variety of reasons, such
as their ability to inhibit the spontaneous emission of light. This and related
properties arise from the formation of photonic bandgaps, whereby multiple
scattering of photons by lattices of periodically varying refractive indices acts
to prevent the propagation of electromagnetic waves having certain wavelengths.
One route to forming photonic crystals is to etch two-dimensional periodic
lattices of vertical air holes into dielectric slab waveguides. Such structures
can show complete photonic bandgaps, but only for large-diameter air holes in
materials of high refractive index (such as gallium arsenide, n = 3.69), which
unfortunately leads to significantly reduced optical transmission when combined
with optical fibres of low refractive index. It has been suggested that
quasicrystalline (rather than periodic) lattices can also possess photonic
bandgaps. Here we demonstrate this concept experimentally and show that it
enables complete photonic bandgaps--non-directional and for any polarization--to
be realized with small air holes in silicon nitride (n = 2.02), and even glass (n
= 1.45). These properties make photonic quasicrystals promising for application
in a range of optical devices.
PMID- 10783883
TI - Manipulation of atoms across a surface at room temperature
AB - Since the realization that the tips of scanning probe microscopes can interact
with atoms at surfaces, there has been much interest in the possibility of
building or modifying nanostructures or molecules directly from single atoms.
Individual large molecules can be positioned on surfaces, and atoms can be
transferred controllably between the sample and probe tip. The most complex
structures are produced at cryogenic temperatures by sliding atoms across a
surface to chosen sites. But there are problems in manipulating atoms laterally
at higher temperatures--atoms that are sufficiently well bound to a surface to be
stable at higher temperatures require a stronger tip interaction to be moved.
This situation differs significantly from the idealized weakly interacting tips
of scanning tunnelling or atomic force microscopes. Here we demonstrate that
precise positioning of atoms on a copper surface is possible at room temperature.
The triggering mechanism for the atomic motion unexpectedly depends on the
tunnelling current density, rather than the electric field or proximity of tip
and surface.
PMID- 10783884
TI - Self-assembly of nanoparticles into structured spherical and network aggregates
AB - Multi-scale ordering of materials is central for the application of molecular
systems in macroscopic devices. Self-assembly based on selective control of non
covalent interactions provides a powerful tool for the creation of structured
systems at a molecular level, and application of this methodology to
macromolecular systems provides a means for extending such structures to
macroscopic length scale. Monolayer-functionalized nanoparticles can be made with
a wide variety of metallic and non-metallic cores, providing a versatile building
block for such approaches. Here we present a polymer-mediated 'bricks and mortar'
strategy for the ordering of nanoparticles into structured assemblies. This
methodology allows monolayer-protected gold particles to self-assemble into
structured aggregates while thermally controlling their size and morphology.
Using 2-nm gold particles as building blocks, we show that spherical aggregates
of size 97 +/- 17 nm can be produced at 23 degrees C, and that 0.5-1 microm
spherical assemblies with (5-40) x 10(5) individual subunits form at -20 degrees
C. Intriguingly, extended networks of approximately 50-nm subunits are formed at
10 degrees C, illustrating the potential of our approach for the formation of
diverse structural motifs such as wires and rods. These findings demonstrate that
the assembly process provides control over the resulting aggregates, while the
modularity of the 'bricks and mortar' approach allows combinatorial control over
the constituents, providing a versatile route to new materials systems.
PMID- 10783885
TI - Subduction erosion along the Middle America convergent margin
AB - 'Subduction erosion' has been invoked to explain material missing from some
continents along convergent margins. It has been suggested that this form of
tectonic erosion removes continental material at the front of the margin or along
the underside of the upper (continental) plate. Frontal erosion is interpreted
from disrupted topography at the base of a slope and is most evident in the wake
of subducting seamounts. In contrast, structures resulting from erosion at the
base of a continental plate are seldom recognized in seismic reflection images
because such images typically have poor resolution at distances greater than
approximately 5 km from the trench axis. Basal erosion from seamounts and ridges
has been inferred, but few large subducted bodies--let alone the eroded base of
the upper plate--are imaged convincingly. From seismic images we identify here
two mechanisms of basal erosion: erosion by seamount tunnelling and removal of
large rock lenses of a distending upper plate. Seismic cross-sections from Costa
Rica to Nicaragua indicate that erosion may extend along much of the Middle
America convergent margin.
PMID- 10783886
TI - Quantitative evidence for global amphibian population declines.
AB - Although there is growing concern that amphibian populations are declining
globally, much of the supporting evidence is either anecdotal or derived from
short-term studies at small geographical scales. This raises questions not only
about the difficulty of detecting temporal trends in populations which are
notoriously variable, but also about the validity of inferring global trends from
local or regional studies. Here we use data from 936 populations to assess large
scale temporal and spatial variations in amphibian population trends. On a global
scale, our results indicate relatively rapid declines from the late 1950s/early
1960s to the late 1960s, followed by a reduced rate of decline to the present.
Amphibian population trends during the 1960s were negative in western Europe
(including the United Kingdom) and North America, but only the latter populations
showed declines from the 1970s to the late 1990s. These results suggest that
while large-scale trends show considerable geographical and temporal variability,
amphibian populations are in fact declining--and that this decline has been
happening for several decades.
PMID- 10783887
TI - The metapopulation capacity of a fragmented landscape.
AB - Ecologists and conservation biologists have used many measures of landscape
structure to predict the population dynamic consequences of habitat loss and
fragmentation, but these measures are not well justified by population dynamic
theory. Here we introduce a new measure for highly fragmented landscapes, termed
the metapopulation capacity, which is rigorously derived from metapopulation
theory and can easily be applied to real networks of habitat fragments with known
areas and connectivities. Technically, metapopulation capacity is the leading
eigenvalue of an appropriate 'landscape' matrix. A species is predicted to
persist in a landscape if the metapopulation capacity of that landscape is
greater than a threshold value determined by the properties of the species.
Therefore, metapopulation capacity can conveniently be used to rank different
landscapes in terms of their capacity to support viable metapopulations. We
present an empirical example on multiple networks occupied by an endangered
species of butterfly. Using this theory, we may also calculate how the
metapopulation capacity is changed by removing habitat fragments from or adding
new ones into specific spatial locations, or by changing their areas. The
metapopulation capacity should find many applications in metapopulation ecology,
landscape ecology and conservation biology.
PMID- 10783888
TI - Asymmetric redirection of flow through the heart.
AB - Through cardiac looping during embryonic development, paths of flow through the
mature heart have direction changes and asymmetries whose topology and functional
significance remain relatively unexplored. Here we show, using magnetic resonance
velocity mapping, the asymmetric redirection of streaming blood in atrial and
ventricular cavities of the adult human heart, with sinuous, chirally asymmetric
paths of flow through the whole. On the basis of mapped flow fields and drawings
that illustrate spatial relations between flow paths, we propose that asymmetries
and curvatures of the looped heart have potential fluidic and dynamic advantages.
Patterns of atrial filling seem to be asymmetric in a manner that allows the
momentum of inflowing streams to be redirected towards atrio-ventricular valves,
and the change in direction at ventricular level is such that recoil away from
ejected blood is in a direction that can enhance rather than inhibit ventriculo
atrial coupling. Chiral asymmetry might help to minimize dissipative interaction
between entering, recirculating and outflowing streams. These factors might
combine to allow a reciprocating, sling-like, 'morphodynamic' mode of action to
come into effect when heart rate and output increase during exercise.
PMID- 10783889
TI - Interruption of a basal ganglia-forebrain circuit prevents plasticity of learned
vocalizations.
AB - Birdsong, like speech, is a learned vocal behaviour that relies greatly on
hearing; in both songbirds and humans the removal of auditory feedback by
deafening leads to a gradual deterioration of adult vocal production. Here we
investigate the neural mechanisms that contribute to the processing of auditory
feedback during the maintenance of song in adult zebra finches. We show that the
deleterious effects on song production that normally follow deafening can be
prevented by a second insult to the nervous system--the lesion of a basal ganglia
forebrain circuit. The results suggest that the removal of auditory feedback
leads to the generation of an instructive signal that actively drives non
adaptive changes in song; they also suggest that this instructive signal is
generated within (or conveyed through) the basal ganglia-forebrain pathway. Our
findings provide evidence that cortical-basal ganglia circuits may participate in
the evaluation of sensory feedback during calibration of motor performance, and
demonstrate that damage to such circuits can have little effect on previously
learned behaviour while conspicuously disrupting the capacity to adaptively
modify that behaviour.
PMID- 10783890
TI - SHATTERPROOF MADS-box genes control seed dispersal in Arabidopsis.
AB - The fruit, which mediates the maturation and dispersal of seeds, is a complex
structure unique to flowering plants. Seed dispersal in plants such as
Arabidopsis occurs by a process called fruit dehiscence, or pod shatter. Few
studies have focused on identifying genes that regulate this process, in spite of
the agronomic value of controlling seed dispersal in crop plants such as canola.
Here we show that the closely related SHATTERPROOF (SHP1) and SHATTERPROOF2
(SHP2) MADS-box genes are required for fruit dehiscence in Arabidopsis. Moreover,
SHP1 and SHP2 are functionally redundant, as neither single mutant displays a
novel phenotype. Our studies of shp1 shp2 fruit, and of plants constitutively
expressing SHP1 and SHP2, show that these two genes control dehiscence zone
differentiation and promote the lignification of adjacent cells. Our results
indicate that further analysis of the molecular events underlying fruit
dehiscence may allow genetic manipulation of pod shatter in crop plants.
PMID- 10783891
TI - Rapid degradation of a large fraction of newly synthesized proteins by
proteasomes.
AB - MHC class I molecules function to present peptides eight to ten residues long to
the immune system. These peptides originate primarily from a cytosolic pool of
proteins through the actions of proteasomes, and are transported into the
endoplasmic reticulum, where they assemble with nascent class I molecules. Most
peptides are generated from proteins that are apparently metabolically stable. To
explain this, we previously proposed that peptides arise from proteasomal
degradation of defective ribosomal products (DRiPs). DRiPs are polypeptides that
never attain native structure owing to errors in translation or post
translational processes necessary for proper protein folding. Here we show,
first, that DRiPs constitute upwards of 30% of newly synthesized proteins as
determined in a variety of cell types; second, that at least some DRiPs represent
ubiquitinated proteins; and last, that ubiquitinated DRiPs are formed from human
immunodeficiency virus Gag polyprotein, a long-lived viral protein that serves as
a source of antigenic peptides.
PMID- 10783892
TI - The major substrates for TAP in vivo are derived from newly synthesized proteins.
AB - The transporter associated with antigen processing (TAP) is a member of the
family of ABC transporters that translocate a large variety of substrates across
membranes. TAP transports peptides from the cytosol into the endoplasmic
reticulum for binding to MHC class I molecules and for subsequent presentation to
the immune system. Here we follow the lateral mobility of TAP in living cells.
TAP's mobility increases when it is inactive and decreases when it translocates
peptides. Because TAP activity is dependent on substrate, the mobility of TAP is
used to monitor the intracellular peptide content in vivo. Comparison of the
diffusion rates in peptide-free and peptide-saturated cells indicates that
normally about one-third of all TAP molecules actively translocate peptides.
However, during an acute influenza infection TAP becomes fully employed owing to
the production and degradation of viral proteins. Furthermore, TAP activity
depends on continuing protein translation. This implies that MHC class I
molecules mainly sample peptides that originate from newly synthesized proteins,
to ensure rapid presentation to the immune system.
PMID- 10783893
TI - NAK is an IkappaB kinase-activating kinase.
AB - Phosphorylation of IkappaB by the IkappaB kinase (IKK) complex is a critical step
leading to IkappaB degradation and activation of transcription factor NF-kappaB.
The IKK complex contains two catalytic subunits, IKKalpha and IKKbeta, the latter
being indispensable for NF-kappaB activation by pro-inflammatory cytokines.
Although IKK is activated by phosphorylation of the IKKbeta activation loop, the
physiological IKK kinases that mediate responses to extracellular stimuli remain
obscure. Here we describe an IKK-related kinase, named NAK (NF-kappaB-activating
kinase), that can activate IKK through direct phosphorylation. NAK induces
IkappaB degradation and NF-kappaB activity through IKKbeta. Endogenous NAK is
activated by phorbol ester tumour promoters and growth factors, whereas
catalytically inactive NAK specifically inhibits activation of NF-kappaB by
protein kinase C-epsilon (PKCepsilon). Thus, NAK is an IKK kinase that may
mediate IKK and NF-kappaB activation in response to growth factors that stimulate
PKCepsilon activity.
PMID- 10783894
TI - AFX-like Forkhead transcription factors mediate cell-cycle regulation by Ras and
PKB through p27kip1.
AB - The Forkhead transcription factors AFX, FKHR and FKHR-L1 are orthologues of DAF
16, a Forkhead factor that regulates longevity in Caenorhabditis elegans. Here we
show that overexpression of these Forkhead transcription factors causes growth
suppression in a variety of cell lines, including a Ras-transformed cell line and
a cell line lacking the tumour suppressor PTEN. Expression of AFX blocks cell
cycle progression at phase G1, independent of functional retinoblastoma protein
(pRb) but dependent on the cell-cycle inhibitor p27kip1. Indeed, AFX
transcriptionally activates p27kip1, resulting in increased protein levels. We
conclude that AFX-like proteins are involved in cell-cycle regulation and that
inactivation of these proteins is an important step in oncogenic transformation.
PMID- 10783896
TI - Universities encourage industrialists to come back to their roots.
PMID- 10783895
TI - Normalizing mitochondrial superoxide production blocks three pathways of
hyperglycaemic damage.
AB - Diabetic hyperglycaemia causes a variety of pathological changes in small
vessels, arteries and peripheral nerves. Vascular endothelial cells are an
important target of hyperglycaemic damage, but the mechanisms underlying this
damage are not fully understood. Three seemingly independent biochemical pathways
are involved in the pathogenesis: glucose-induced activation of protein kinase C
isoforms; increased formation of glucose-derived advanced glycation end-products;
and increased glucose flux through the aldose reductase pathway. The relevance of
each of these pathways is supported by animal studies in which pathway-specific
inhibitors prevent various hyperglycaemia-induced abnormalities. Hyperglycaemia
increases the production of reactive oxygen species inside cultured bovine aortic
endothelial cells. Here we show that this increase in reactive oxygen species is
prevented by an inhibitor of electron transport chain complex II, by an uncoupler
of oxidative phosphorylation, by uncoupling protein-1 and by manganese superoxide
dismutase. Normalizing levels of mitochondrial reactive oxygen species with each
of these agents prevents glucose-induced activation of protein kinase C,
formation of advanced glycation end-products, sorbitol accumulation and NFkappaB
activation.
PMID- 10783897
TI - Georgia realizes the commercial potential of science.
PMID- 10783898
TI - Estrogen and substrate metabolism: a review of contradictory research.
AB - The increasing number of females participating in physical activity has
heightened our awareness of changes in the menstrual cycle which often accompany
physical activity. As such, there has been a considerable amount of research
investigating the relationships between menstrual cycle changes and bone mineral
density, performance, ventilation and substrate metabolism. A number of
researchers have concluded that there may be enhanced fat metabolism in
eumenorrhoeic versus amenorrhoeic females, or in the follicular phase versus the
luteal phase of the menstrual cycle, due to the theoretical estrogen level in
eumenorrhoeic versus amenorrhoeic females or the luteal phase versus the
follicular phase. However, a definite relationship between resting estrogen level
and substrate metabolism has not been clearly established. In addition, the
mechanisms which may be responsible for the effect of estrogen on substrate
metabolism have not been addressed. It appears that the effects of estrogen on
metabolism may be via the effect of estrogen on glucogenic hormones or lipolytic
enzymes. Therefore, the primary purpose of this review is to explore the effects
of estrogen on substrate metabolism. Menstrual cycle physiology and possible
mechanisms for the effects of estrogen on metabolism, as well as previous
research on estrogen and metabolism in rats and humans, will be discussed.
PMID- 10783900
TI - The physically-challenged athlete: medical issues and assessment.
AB - The rate and pattern of injuries is similar in both physically-challenged and
able-bodied athletic participation. However, understanding of the unique medical
issues faced by physically-challenged athletes is necessary in conducting
appropriate pre-participation evaluations and developing strategies for injury
prevention and medical management. Review of the literature provides insight for
choosing relevant tests and interpreting components of the physical examination
for this population. More research is needed in the management of medical
problems specific to the physically-challenged athlete.
PMID- 10783899
TI - Maximising the clinical use of exercise gaseous exchange testing in children with
repaired cyanotic congenital heart defects: the development of an appropriate
test strategy.
AB - Implicit in deciding upon an exercise test strategy to elucidate cardiopulmonary
function in children with congenital heart disease are appropriate application of
gas exchange techniques and the significance of the data collected to the
specific congenital heart disorder. Post-operative cardiopulmonary responses to
exercise in cyanotic disorders are complex and, despite a large body of extant
literature in paediatric patients, there has been much difficulty in achieving
quality and consistency of data. Maximal oxygen uptake is widely recognised as
the best single indicator of cardiopulmonary function and has therefore been the
focus of most clinical exercise tests in children. Many children with various
heart anomalies are able to exercise to maximum without adverse symptoms, and it
is essential that test termination is based on the same criteria for these
children. Choosing appropriate, valid indicators of maximum in children with
congenital heart disease is beset by difficulties. Such maximal intensity
exercise testing procedures have been challenged on the grounds that they do not
give a good indication of cardiopulmonary function that is relevant to real life
situations. Furthermore, they are prone to much interindividual variability and
error in the definition of maximal exertion. Alternative strategies have been
proposed which focus upon dynamic submaximal and kinetic cardiopulmonary
responses, which are thought to be less dependent on maximal voluntary effort and
more suited to the daily activity patterns of children. These methods are also
not without problems. Variability in anaerobic threshold measurements and
controversy regarding its physiological meaning have been debated. It is
recommended that an appropriate cardiopulmonary exercise gas exchange test
strategy, which provides clinically useful information for children with cyanotic
congenital heart disease, should include both maximal and submaximal data. The
inclusion of oxygen uptake kinetics and ventilatory data are encouraged, since
they may allow the distinction between a pulmonary, cardiovascular or inactivity
related exercise limitation.
PMID- 10783901
TI - Effects of throwing overweight and underweight baseballs on throwing velocity and
accuracy.
AB - The purpose of this review is to determine how throwing overweight and
underweight baseballs affects baseball throwing velocity and accuracy. Two
studies examined how a warm-up with overweight baseballs affected throwing
velocity and accuracy of 5 oz regulation baseballs. One of these studies showed
significant increases in throwing velocity and accuracy, while the other study
found no significant differences. Three training studies (6 to 12 weeks in
duration) using overweight baseballs were conducted to determine how they
affected ball accuracy while throwing regulation baseballs. No significant
differences were found in any study. From these data it is concluded that warming
up or training with overweight baseballs does not improve ball accuracy. Seven
overweight and 4 underweight training studies (6 to 12 weeks in duration) were
conducted to determine how throwing velocity of regulation baseballs was affected
due to training with these overweight and underweight baseballs. The overweight
baseballs ranged in weight from 5.25 to 17 oz, while the underweight baseballs
were between 4 and 4.75 oz. Data from these training studies strongly support the
practice of training with overweight and underweight baseballs to increase
throwing velocity of regulation baseballs. Since no injuries were reported
throughout the training studies, throwing overweight and underweight baseballs
may not be more stressful to the throwing arm compared to throwing regulation
baseballs. However, since currently there are no injury data related to throwing
overweight and underweight baseballs, this should be the focus of subsequent
studies. In addition, research should be initiated to determine whether throwing
kinematics and kinetics are different between throwing regulation baseballs and
throwing overweight and underweight baseballs.
PMID- 10783903
TI - The Zone Diet and athletic performance.
PMID- 10783902
TI - Recurrent posterior thigh symptoms detrimental to performance in rugby union:
predisposing factors.
AB - Recurrent hamstring injury is a very common problem in rugby union, but has been
largely ignored in the literature. It is concluded that a multifactorial
aetiology may be present, and that these symptoms may be part of a continuum of
symptoms that may lead to more serious injuries. Effective management needs to
focus not just locally, but include proximal issues such as lumbo-pelvic
stability and correcting lumbar spine dysfunction. The factors addressed in a
prevention programme are likely to contribute to performance gains.
PMID- 10783904
TI - Examining glucose transport in single vascular smooth muscle cells with a
fluorescent glucose analog.
AB - Changes in vascular smooth muscle glucose transport are thought to contribute to
the pathogenesis of vascular disease in conditions such as diabetes, yet no
single-cell assay for glucose uptake by VSM exists. Therefore, we examined the
uptake of the fluorescent glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4
yl)amino]-2-deoxyglucose (2-NBDG) in isolated pig vascular smooth muscle cells
(VSMC) using digital imaging microscopy. Uptake of 2-NBDG by VSMC was inhibited
by D-glucose but not by L-glucose, suggesting that 2-NBDG enters VSMC via glucose
transporters. Uptake of 2-NBDG was linear in the presence of 10 mM D-glucose
(n=6, R2=0.9408) but not in its absence (n=4, R2=0.9993), indicating that 2-NBDG
is not metabolized and accumulates within the cells. 2-NBDG fluorescence in VSMC
was often non-uniform and appeared to represent binding of 2-NBDG to some
cytoplasmic component. The present study demonstrates that 2-NBDG is a useful
tool for examining vascular smooth muscle glucose uptake at the single cell
level.
PMID- 10783905
TI - Differences between cation-osmotic hemolysis and filterability in exaprolol- and
glutaraldehyde-treated human red blood cells.
AB - The changes in human red blood cell microrheology in different glutaraldehyde
(3.0 and 5.0 x 10(-6) mol x l(-1)) and exaprolol (2.5 and 5.0 x 10(-4) mol x l(
1)) concentrations were studied. The method of millipore filtration was compared
with the method of cation-osmotic hemolysis. Both drugs prolonged the filtration
time. Cation-osmotic hemolysis in glutaraldehyde-treated cells was significantly
lower in comparison with the control group. On the other hand, there was a
significant increase in cation-osmotic hemolysis in exaprolol-treated cells.
Besides cation-osmotic hemolysis and filterability of erythrocytes, we evaluated
the medium cell volume (MCV) and the medium cell hemoglobin concentration (MCHC).
No changes in MCV and MCHC in glutaraldehyde-treated cells were observed.
However, the MCV was significantly lower and the MCHC was significantly higher in
exaprolol-treated cells. In conclusion, we suggest that the method of cation
osmotic hemolysis is more sensitive than the filtration method for determination
of red blood cell microrheology.
PMID- 10783906
TI - Effects of nitric oxide donor, isosorbide dinitrate, on energy metabolism of rat
reticulocytes.
AB - Since nitric oxide (NO) in many cells is involved in energy metabolism, the aim
of this study was to evaluate the role of isosorbide dinitrate (ISDN), a NO
donor, in energy metabolism of rat reticulocytes, particularly due to their high
content of hemoglobin--an effective scavenger of NO. Rat reticulocyte-rich red
blood cell suspensions were aerobically incubated in the absence (control) or in
the presence of different concentrations of ISDN. ISDN decreased total and
coupled oxygen consumption (p<0.05) while increased uncoupled oxygen consumption
(p<0.05) in a dose- and time-dependent manner. This was followed by enhancement
of glycolysis, as measured by increased glucose consumption and lactate
accumulation (p<0.05). Levels of all glycolytic intermediates in the presence of
ISDN indicate only stimulation of pyruvate kinase activity. ISDN did not alter
the concentration of ATP, while increased ADP and AMP levels (p>0.05). In rat
reticulocytes under steady-state conditions, 95.4% of overall energy was produced
by oxidative phosphorylation but only 4.6% by glycolysis. Due to a reduced
coupled oxygen consumption in the presence of ISDN, ATP production via oxidative
phosphorylation was significantly diminished. A simultaneous increase of
glycolytic ATP production is not enough to ensure constant ATP production. The
calculated mean ATP turnover time was prolonged by 199% in the presence of 1.5
mmol/l ISDN. In conclusion, ISDN a) inhibited total and coupled respiration but
enhanced uncoupled respiration, b) stimulated glycolysis, c) decreased ATP
production and d) prolonged ATP turnover time in rat reticulocytes. These effects
were mediated by NO as the effector molecule.
PMID- 10783907
TI - Enalapril in subantihypertensive dosage attenuates kidney proliferation and
functional recovery in normotensive ablation nephropathy of the rat.
AB - Most studies on the antiproliferative action of angiotensin converting enzyme
inhibitors (ACEI) were performed in a rat hypertensive remnant kidney model with
5/6 kidney ablation which raised objections about the antihypertensive effect of
ACEI and the influence of other antihypertensive drugs administered to remnant
kidney control rats. To prevent these objections, a normotensive 4/6 remnant
kidney model was elaborated and a subantihypertensive dosage of enalapril was
used to evaluate its antiproliferative action. Subtotally nephrectomized rats
(Nx) markedly increased the remnant kidney weight during a 4-week period and this
rise was prevented by the treatment with enalapril (NxE) (Nx +297+/-35 mg vs.
sham-operated +145+/-32 mg, p<0.001; NxE +154+/-35 mg vs. Nx p<0.001). While
collagen concentration in the kidney cortex was not increased in sham-operated
rats (Sham) in comparison with the control group (Ctrl) at the beginning of the
study, the subsequent increase was significant in the Nx group and enalapril did
not attenuate this increase (Sham 148+/-5 mg/100 g w.w. vs. Nx 164+/-2 mg/100 g
w.w., p<0.01; NxE 161+/-4 mg/100 g w.w. vs. Sham p<0.05). The tubular protein/DNA
ratio increase, which was significant in the Nx group, was inhibited by enalapril
(Nx 26.2+/-10.5 vs. NxE 15.3+/-2.6, p<0.05). The protein/DNA ratio was much lower
in glomeruli, with no significant changes in either the Nx or NxE groups. Serum
urea concentrations were slightly higher in the Nx group than in the sham
operated group, but markedly elevated in the NxE group (Nx 10.71+/-0.76 mmol/l
vs. Sham 6.10+/-0.33 mmol/l, p<0.001; NxE 28.9+/-2.6 mmol/l vs. Sham p<0.001).
Creatinine concentrations in the Nx group were increased in comparison with the
sham-operated group and markedly increased in the NxE group (Nx 63.7+/-3.56
micromol/l vs. Sham 37.2+/-2.84 micromol/l, p<0.001; NxE 107.0+/-5.2 micromol/l
vs. Sham p<0.001). The clearance of creatinine was lower in the Nx group than in
the sham-operated group and was markedly reduced in the NxE group (Nx 0.89+/-0.06
ml/min.g kidney wt. vs. Sham 1.05+/-0.16 ml/min x g kidney wt., p<0.01; NxE
0.58+/-0.029 ml/min x g kidney wt. vs. Sham, p<0.001). Enalapril improved
proteinuria in comparison with the Nx group (NxE 5.6+/-0.6 mg/24 h vs. Nx 16.1+/
3.4 mg/24 h, p<0.05). Thus remnant kidney proliferation is substantial even in
normotensive rats. It includes both proliferation and collagen accumulation with
partial recovery of kidney weight and function, but is accompanied by enhanced
proteinuria. Enalapril attenuates the proliferation and decreases proteinuria but
prolongs kidney function recovery.
PMID- 10783908
TI - Nephrotoxicity of cyclosporin A in hereditary hypertriglyceridemic rats.
AB - It has been suggested that cyclosporin A (CsA) nephrotoxicity can be reduced by
the concomitant administration of omega-3 fatty acids or vitamin E. The present
study was designed to establish whether the effect of the above substances can
also be demonstrated in rats with hereditary hypertriglyceridemia (HTG) whose
sensitivity to the nephrotoxic effect is greater than in control AVN rats. CsA
administration at a dose of 10 mg/kg/day to HTG rats resulted in a significant
rise (p<0.001) in serum levels of creatinine (from 66.0+/-7.6 to 108.4+/-11.6
micromol/l) and urea (from 8.3+/-0.7 to 22.3+/-18 mmol/l) which was not found in
AVN rats. The baseline values of systolic blood pressure (SBP) were significantly
higher in HTG rats. However, in both strains CsA administration was associated
with a similar SBP increase which was not prevented by omega-3 fatty acids (EPAX)
or vitamin E administration. Concomitant administration of CsA with EPAX at a
dose of 600 mg/kg b.w./day in HTG rats prevented the rise in the serum levels of
creatinine (65.4+/-14.7 micromol/l) and reduced the increase in the serum urea
levels (11.9+/-7.6 mmol/l). Concomitant administration of CsA and vitamin E (at a
dose of 25 mg/kg/day) also reduced the increase (p<0.05) in the serum levels of
creatinine (70.7+/-14.3 micromol/l) and urea (9.8+/-3.4 mmol/l) compared to the
effects elicited by the administration of CsA alone (p<0.05). Administration of
CsA alone or in combination with EPAX or vitamin E did not have a marked effect
on diuresis, proteinuria, urinary osmolality, urinary excretion of urea,
creatinine and potassium. Under all experimental conditions, the rate of urinary
excretion of sodium in HTG rats was significantly lower (p<0.01) than in AVN
rats. The results obtained support the assumption that omega-3 fatty acids and
vitamin E at the doses used reduce CsA nephrotoxicity in rats with hereditary
hypertriglyceridemia whose sensitivity to the nephrotoxic effect of CsA is
significantly higher than in AVN rats.
PMID- 10783909
TI - Hydrogen peroxide in the breath of rats: the effects of hypoxia and paraquat.
AB - The hypothesis that oxidative stress can be induced by hypoxia was tested by
measuring the concentration of hydrogen peroxide by a luminometric technique in
the breath samples of rats exposed to hypoxia and paraquat. The group of animals
(n=15) exposed to normobaric hypoxia (10% O2) for three days had an increased
amount of H2O2 (200%, P<0.001) in their breath in comparison to control animals.
After 7 days of recovery in air, the exposed animals still produced significantly
increased levels of H2O2 (152%, P<0.001). Paraquat administration was used as a
positive control, since it is a redox cycling compound producing free radicals.
In the animals treated with a toxic dose of paraquat, the peak H2O2 production
was observed 5 h after i.p. injection (156%, P<0.02). Within the next 2 h it
decreased to the control level and stayed constant for 48 h, when the animals
began to die. It is suggested that H2O2, observed in the breath samples, is a
product of a metabolic pathway that could itself be sensitive to oxidative
damage.
PMID- 10783910
TI - Role of intracerebroventricular vasopressin in the development of stress-induced
gastric lesions in rats.
AB - We investigated whether arginine vasopressin (AVP) has a central influence on the
development of gastric mucosal lesions evoked by restraint-cold stress in rats.
AVP and vasopressin V1 receptor antagonist were injected
intracerebroventricularly (i.c.v.) and the rats were exposed to restraint-cold
stress for five hours. After decapitation the stomachs were examined for gastric
mucosal lesions which were evaluated according to an ulcer score. Three different
doses of AVP and V1 receptor antagonist were administered in order to investigate
the effects of exogenous and endogenous AVP on stress-induced gastric mucosal
lesions. The intensity of gastric mucosal lesions was reduced when exogenous AVP
was injected intracerebroventricularly. On the other hand, vasopressin V1
receptor antagonist, which was administered by the same route, augmented gastric
mucosal lesions. Our findings indicate that AVP, injected centrally, plays a role
in preventing the formation of gastric mucosal lesions induced by stress via a
central V1 receptor.
PMID- 10783911
TI - Long- and medium-chain triacylglycerols in nutritional support of liver
regeneration of partially hepatectomized rats.
AB - An appropriate choice for a suitable diet during liver regeneration still remains
an enigma. To investigate the effect of isocaloric enteral feeding with medium
chain triacylglycerols (MCT) and long-chain triacylglycerols (LCT) supplement
(MCT+LCT, 40%:60% w:w) (178 kJ/kg b.w./24 h), rat liver regeneration was studied
24 and 72 h after partial hepatectomy. The liver DNA synthesis 24 h after partial
hepatectomy was significantly higher in the MCT+LCT-supplemented rats (30.2+/-8.2
x 10(3) dpm/mg liver DNA) compared to MCT-treated animals (18.1+/-5.7 x 10(3)
dpm/mg liver DNA). Liver protein synthesis was non-significantly elevated both 24
and 72 h after surgery in MCT+LCT-supplemented rats (13.7+/-1.1 and 10.9+/-3.1 x
10(3) dpm/mg liver protein). Seventy-two hours after partial hepatectomy, the
hepatocyte mitotic activity was significantly increased in MCT+LCT- supplemented
group vs. LCT- or MCT-fed rats (3.3+/-0.7 vs. 1.9+/-0.7 or 1.0+/-0.6 mitoses per
1000 hepatocytes), thus exhibiting an increased proliferative potential. The
results showed a qualitative difference according to the proportion of MCT to LCT
in the enteral supplements. Overfeeding with MCT decreased body weight, increased
liver weight by its fatty infiltration, increased rat mortality rate and reduced
spontaneous caloric intake. We conclude that the balanced supplement of MCT+LCT
(40%:60% w:w) preserves liver regeneration, whereas overfeeding with MCT seems to
be deleterious.
PMID- 10783912
TI - The role of human glutathione S-transferases M1 and T1 in individual
susceptibility to bladder cancer.
AB - Several genes involved in the metabolism of carcinogens have been found to be
polymorphic in the human population, and specific alleles are associated with
increased risk of cancer at various sites. This study is focused on the
polymorphic enzymes glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) that are
involved in the detoxification of many xenobiotics involved in the etiology of
bladder cancer. To investigate the role of GSTM1 and GSTT1 in bladder
carcinogenesis, the polymerase chain reaction was used to determine GSTM1 and
GSTT1 genotypes of cancer patients (n = 76) and controls (n = 248). The
proportion of putative risk GSTM1 null genotype in the case group was 52.6%,
compared to 49.6% in the control group, but the GSTT1 0/0 frequency in the
bladder cancer group was significantly higher (P = 0.04) in comparison with the
control group (27.6 vs 16.9%). Individuals lacking the GSTT1 gene are at an
approximately 1.9-fold higher risk (OR = 1.87, C.I. 95% = 1.03-3.42) of
developing bladder cancer in comparison with individuals with at least one active
allele in the GSTT1 locus. A significantly higher incidence of GSTM1 deletion
genotype (P = 0.02) was found in smokers with bladder cancer compared to the
controls (70.6 vs 49.6%). Smokers lacking the GSTM1 gene are at an approximately
2.4-fold higher risk of bladder cancer (OR = 2.44, C.I. 95% = 1.10-5.30). The
effect of smoking associated with the GSTT1 0/0 genotype was not found to affect
the risk of bladder cancer.
PMID- 10783913
TI - Early inflammatory cytokine and acute phase protein response under the stress of
thermal injury in rats.
AB - The acute inflammatory response associated with thermal injury was examined in
rats. The appearance of mediators of inflammation in the systemic circulation,
including cytokines interleukin-1 (IL-1), tumor necrosis factor (TNF) and
interleukin-6 (IL-6) and acute phase proteins were assessed during initial 72 h
following thermal injury. Increased levels of activity were noted for all three
cytokines, but with a different time-course. While serum IL-1 activity was
elevated throughout the 3-day period of observation, the levels of serum TNF
activity were enhanced after 12 h and on days 1 and 3 following scalding injury.
The values of IL-6 were already increased one hour after thermal injury and
increased progressively up to day 1 following scalding. Alpha2-macroglobulin and
haptoglobin levels were increased 12 h after thermal injury, rising further on
days 1 and 3. Positive correlation was found between the time-course of increased
serum IL-6 activity and alpha2-macroglobulin, as well as between TNF and
haptoglobin in the serum.
PMID- 10783914
TI - Permanent alterations of spinal cord reflexes following nerve lesion in newborn
rats.
AB - Sciatic nerve lesion in newborn rats is known to cause degeneration of a large
number of axotomized motoneurones and spinal ganglion cells. Some of the
surviving motoneurones exhibit abnormal firing properties and the projection
pattern of central terminals of sensory neurones is altered. We report here on
long-term changes in spinal cord reflexes in adult rats following neonatal nerve
crush. In acutely spinalized and anaesthetized adult rats 4-6 months old in which
the sciatic nerve had been crushed on one side at birth, the tibial nerve, common
peroneal nerve or sural nerve were stimulated on the reinnervated and control
side and reflex responses were recorded from the L5 ventral spinal roots. Ventral
root responses (VRRs) to tibial and peroneal nerve stimulation on the side of the
nerve lesion were significantly smaller in amplitude representing only about 15%
of the mean amplitude of VRRs on the control side. The calculated central delay
of the first, presumably monosynaptic component of the VRR potential was 1.6 ms
on the control side while the earliest VRR wave on the side of the nerve lesion
appeared after a mean central latency of 4.0 ms that seems too long to be of
monosynaptic origin. These results suggest that neonatal sciatic nerve injury
markedly alters the physiological properties and synaptic connectivity in spinal
cord neurones and causes a marked depression of spinal cord responses to
peripheral nerve stimulation.
PMID- 10783915
TI - Midazolam suppresses spike-and-wave rhythm accompanying three different models of
epileptic seizures.
AB - The action of a water-soluble benzodiazepine midazolam (0.1 and 1 mg/kg i.p.) was
tested against three models of spike-and-wave rhythm in rats: rhythmic metrazol
activity (a model of human absence seizures), minimal metrazol seizures, and
epileptic afterdischarges induced by low-frequency cortical stimulation (probably
models of human myoclonic seizures). Midazolam was able to reduce spike-and-wave
activity in all three models, but there were quantitative differences: the lower
dose was effective only against rhythmic metrazol activity, but its action
against two other models was negligible, whereas the higher dose of midazolam
resulted in significant effects in all three models. These quantitative
differences are not sufficient to prove our hypothesis that the spike-and-wave
rhythm represents different phenomena in various models. A spread of epileptic
activity into brain structures other than the thalamocortical system determines
the type of epileptic seizures.
PMID- 10783916
TI - Antipentylenetetrazol action of clobazam in developing rats.
AB - Clobazam (0.5 to 7.5 mg/kg i.p.) was tested against motor seizures elicited by
pentylenetetrazol in rats 7, 12, 18, 25 and 90 days old. Minimal, predominantly
clonic seizures with preserved righting ability were reliably induced by
pentylenetetrazol and suppressed by clobazam in rats aged 18 days or more. The
incidence of minimal seizures after clobazam pretreatment was not increased in 7-
and 12-day-old rat pups. Generalized tonic-clonic seizures were markedly
suppressed by clobazam in all age groups. In 18-day-old and older animals
clobazam doses suppressing generalized seizures were always lower than those
necessary for exerting an effect on minimal seizures. The differences in clobazam
action appearing at various levels of maturation are only quantitative.
PMID- 10783917
TI - Regulation of Na+, K+-ATPase density by the extracellular ionic and osmotic
environment in bovine articular chondrocytes.
AB - The abundance of Na+, K+-ATPase in cartilage is controlled by the ionic
composition of the extracellular environment of chondrocytes, and specifically
depends on the local concentration of polyanionic matrix proteoglycans. In this
study, it was found that the plasma membrane density of Na+, K+-ATPase in
isolated chondrocytes is sensitive to both ionic and osmotic changes in the
extracellular environment. The upregulation observed experimentally was similar
in magnitude as measured by 3H-ouabain binding, which indicates that chondrocytes
respond adaptively to both ionic and osmotic stimuli. The precise mechanism for
this novel mode of Na+, K+-ATPase regulation has yet to be elucidated.
Physiological perturbation of the ionic and osmotic environment of chondrocytes
may alter intracellular Na+ concentration and this may be one of a number of
stimuli responsible for alterations to the expression and plasma membrane
abundance of Na+, K+-ATPase in the cells.
PMID- 10783918
TI - Effects of immobilization stress combined with water immersion and chronic
amphetamine treatment on the adenylyl cyclase activity in rat neurohypophysis.
AB - Several papers have indicated the participation of cyclic AMP as a second
messenger for the release of neurohypophysial hormones. Since very little is
known about the effects of stress and drugs of abuse on this process, we studied
the activity of adenylyl cyclase in the neurohypophyses after immobilization
stress and chronic amphetamine treatment. Our findings indicate the involvement
of cyclic AMP in the regulation of neurohypophysis as well as the increase in
total adenylyl cyclase both after application of immobilization stress combined
with water immersion and after chronic amphetamine treatment.
PMID- 10783919
TI - Unusual intrafusal fibres in human muscle spindles.
AB - We have studied the morphology and pattern of expression of myosin heavy chain
(MHC) isoforms of intrafusal fibres in a human first lumbrical muscle. Each
intrafusal fibre type, namely nuclear bag1, nuclear bag2 and nuclear chain
fibres, had a distinct MHC composition and distribution of different MHC isoforms
along the whole length of intrafusal fibres. However, most muscle spindles
analyzed also contained one or several intrafusal fibres exhibiting an extrafusal
or mixed pattern of immunoreactivity which did not correspond to any of the
described intrafusal fibre types. We conclude that the latter fibres do not
represent new intrafusal fibre types, but their morphology and expression of MHC
merely reflects the differences in their innervation owing to their unusual
localization at the edge or outside the axial bundle of intrafusal fibres.
PMID- 10783920
TI - Model of lymphocyte migration in Merino ewes under physiological conditions.
AB - The paper presents an example of a new type of a structured model containing time
delays in parallel branches. This model was selected as optimal to describe
mathematically the lymphocyte migration between the venous blood and prescapular
lymph in Merino ewes under physiological conditions. The model allowed to
identify and quantify several lymphocyte fractions exhibiting different migration
dynamics.
PMID- 10783921
TI - Performance of dual-microphone in-the-ear hearing aids.
AB - Fifty subjects with mild to moderate-severe sensorineural hearing loss and prior
experience with binaural amplification were evaluated at two sites (25 subjects
at each site). Signal-to-noise ratios (SNRs) were measured using the Hearing in
Noise Test (HINT) after each subject wore binaural in-the-ear hearing aids
programmed for omnidirectional and dual-microphone performance, for 4 weeks. Both
microphone conditions were evaluated under "ideal" (signal at 0 degrees; noise at
180 degrees) and "diffuse" (signal at 0 degrees; correlated noise at 45 , 135
degrees, 225 degrees, and 315 degrees) listening conditions. Results revealed
statistically significant mean improvements in SNRs between 3.7 and 3.5 dB at
Site I and 3.2 and 2.7 dB at Site II for the ideal and diffuse listening
conditions, respectively, for the dual-microphones in comparison to the
performance provided by the omnidirectional microphone.
PMID- 10783922
TI - Assessing growth of loudness in children by cross-modality matching.
AB - This study examined the clinical feasibility, validity, and reliability of
loudness growth assessment using cross-modality matching (CMM) between line
length and loudness in 16 children 4 to 12 years old with normal hearing or
bilateral sensorineural hearing losses ranging from moderate to severe in degree.
Eight adult listeners with normal hearing were used as a comparison group.
Loudness growth functions and real-ear measures were obtained for 500-Hz and
2,000-Hz narrowband noise stimuli for each individual. No significant differences
were found between the loudness slope values for the adults and children with
normal hearing. Loudness growth functions of the children with sensorineural
hearing loss were significantly steeper (larger) than the slopes obtained from
children with normal hearing. The numeric slope value of the loudness growth
function became larger and more variable as children's hearing threshold
increased and differed for children with similar thresholds. The loudness
functions obtained for retested participants at two different test sessions were
highly correlated. Real-ear measurements revealed that for equivalent input
stimulus levels, significantly higher stimulus levels were present in the ear
canals of children versus adults. Although adults and children with normal
hearing had similar overall rates of loudness growth, discrete points along the
loudness growth function were judged to be louder by the children. This
preliminary study suggests that measures of loudness growth using CMM between
line length and loudness are feasible, valid, and reliable in children with
normal hearing or sensorineural hearing loss. The individual variability noted in
slope values for children with hearing loss attests to the importance of
subjective assessments of loudness. The protocol used in this study may have
potential as a clinical tool for selecting and fitting amplification technology
for children with hearing loss as young as 6 years.
PMID- 10783923
TI - Effect of stimulation rate on cochlear implant recipients' thresholds and maximum
acceptable loudness levels.
AB - Clinically, speech processor programs are created using electrical thresholds and
maximum acceptable loudness levels (MALs) at several different stimulation rates
to determine what rate will provide cochlear implant recipients with the best
speech recognition when using fast-rate speech coding strategies. This study was
designed to determine the difference in thresholds and MALs (expressed in the
clinical unit, Current Level [CL]) for pairs of six rates spanning those
available with the Nucleus 24 device (i.e., 250 to 2,400 pps/ch) using monopolar,
25 microsec/phase stimulation. Test-retest measures of threshold and MAL for each
rate were obtained from seven adult Nucleus 24 recipients on each of 11
electrodes. The difference in threshold and in MAL between pairs of rates was
dependent on the absolute CL. Below approximately 190 CL, thresholds and MALs
decreased with increasing rate; above 210 CL, there was little change in
threshold or MAL with increasing rate. Based on these findings, an approach to
estimating threshold and MAL from one rate to another is suggested, pending
further research.
PMID- 10783924
TI - Improving audibility with nonlinear amplification for listeners with high
frequency loss.
AB - In contrast to fitting strategies for linear amplification that have been
frequently refined for listeners with different degrees of hearing loss, we know
relatively little about the effects of nonlinear amplification for differing
audiometric configurations. The purpose of the current study was to determine
whether increases in audibility with nonlinear amplification improved speech
recognition to a comparable degree for listeners with sloping sensorineural loss
as for a comparison group of listeners with flat sensorineural loss. Consonant
recognition was examined as a function of audibility with wide dynamic range
compression amplification and with linear amplification. For linearly amplified
speech, listeners with flat and sloping loss showed similar improvements in
recognition given the same increases in audibility. Results for nonlinearly
amplified speech indicated that the listeners with flat loss showed a greater
rate of improvement as audibility increases than the listeners with sloping loss.
This difference is largely due to superior performance by the listeners with
sloping loss for low-audibility speech in comparison to equivalent group
performance for high-audibility speech.
PMID- 10783925
TI - Articulation index and hearing handicap.
AB - This investigation examined the relationship between perceived hearing handicap
and the Articulation Index (AI) and the extent to which this relationship was
influenced by the variables age, gender, degree of hearing loss, and audiometric
slope. Subject age, gender, pure-tone thresholds, and scores for the Self
Assessment of Communication (SAC) and the Significant Other Assessment of
Communication (SOAC) were extracted retrospectively from 373 patient files (194
males, 179 females). Correlation analysis revealed a significant (p < .01)
negative relationship between AI values and both measures of hearing handicap,
and also indicated that SAC/SOAC total scores correlated significantly (p < .01)
with each other. Partial correlation analyses revealed that degree of hearing
loss was the only variable under study that had substantial influence on the
strength of AI/hearing handicap correlations.
PMID- 10783926
TI - Preferred listening levels of children who use hearing aids: comparison to
prescriptive targets.
AB - The preferred listening levels (PLLs) of children with sensorineural hearing loss
were elicited using conversation-level speech, heard through the children's own
hearing aids. All hearing aids were fitted using the desired sensation level
(DSL) method. Comparisons were made between the PLL and targets from the
following prescriptive formulae: DSL version 4.1 and two versions of the National
Acoustic Laboratories (NAL) procedure, including NAL revised for severe-profound
losses (NAL)-RP and NAL nonlinear NAL/NL1. Results for this sample of children
indicated that the PLL was similar to the DSL targets, and that, on average, NAL
RP/NL1 targets recommended less gain than that preferred by the majority of
children in this study. The implications of factors such as acclimatization, test
levels, and clinical procedures on these results are discussed.
PMID- 10783927
TI - Quality of life questionnaires for all respiratory diseases, every language and
ethnic minorities. Are alternatives available?
PMID- 10783928
TI - Pulmonary calcifications: a review.
AB - Pulmonary calcification is a common asymptomatic finding, usually discovered on
routine chest X-ray or at autopsy. Pulmonary calcifications are caused mainly by
two mechanisms: the dystrophic form and the metastatic form (1). Despite the
different aetiologies, the pulmonary function and clinical manifestations are
quite similar in both forms. We present a review of the clinical and radiology
findings of the different aspects of pulmonary calcifications according to its
pathogenesis and its anatomic distribution: parenchymal, lymphe node and pleural.
PMID- 10783929
TI - Inter-laboratory comparison of flow-volume curve measurements as quality control
procedure in the framework of an international epidemiological study (PEACE
project).
AB - The aim of this work was to describe the results of a simple quality control
procedure for the flow-volume curve adopted in a multicentre epidemiological
study (PEACE). In 14 centres, 8-15 individuals (n = 157) performed forced vital
capacity (FVC) manoeuvres following a standard protocol with both the local
spirometer/pneumotachograph and a portable spirometer (i.e. the 'reference
instrument' for this study). Deviances of measurements were assessed by computing
the differences (delta) between the former and the latter, the ratios of such
differences on portable spirometer values (delta %) and the coefficients of
variation (CV). The portable spirometer yielded lower mean AFVC and deltaFEV1
(forced in 1 sec) than local instruments (except for two and four centres,
respectively). In most instances, differences were statistically significant.
Absolute mean A%FVC ranged from 4.9-18.2%, while delta%FEV1 ranged from 2.3
18.5%. The Bland and Altman analysis showed a good agreement between the portable
and local instruments, except for two centres, where a systematic trend towards
higher individual absolute deltaFVC and deltaFEV1 was observed. The overall
variability, assessed by CV, was within 6.2% and 5.1% for FVC and FEV1,
respectively: it was similar to other quality control studies ranging from 2.0
5.5% for FVC and 2.2-5.8% for FEV1. Our results point out the importance of
performing interlaboratory comparisons as a quality control procedure in
multicentre epidemiological studies on lung function, and of stimulating
manufacturers to extend the accuracy and precision of the instruments.
PMID- 10783930
TI - Direct medical costs of chronic obstructive pulmonary disease: chronic bronchitis
and emphysema.
AB - In this study we aimed to estimate direct medical costs of Chronic Obstructive
Pulmonary Disease (COPD) by disease type; chronic bronchitis and emphysema. This
study estimates direct costs in 1996 dollars using a prevalence approach and both
aggregate and microcosting. A societal perspective is taken using prevalence, and
multiple national, state and local data sources are used to estimate health-care
utilization and costs. Chronic bronchitis and emphysema together account for
$14.5 billion in annual direct costs. Inpatient costs are greater than outpatient
and emergency costs ($8.3 vs. $7.8 billion) and hospital and medication costs
account for most resources spent. The high prevalence of chronic bronchitis
accounts for its larger total costs ($11.7 billion) compared with emphysema ($2.8
billion). Emphysema, which is more severe, has higher costs per prevalent case
($1341 vs. $816). Hospital stays account for the highest costs, $6.0 billion for
chronic bronchitis and $1.9 billion for emphysema. The hospitalization rate,
length of stay and average cost per prevalent case are higher for emphysema than
for chronic bronchitis. Medication costs are the second highest cost category
($4.4 billion for chronic bronchitis, $0.693 billion for emphysema). The high
hospitalization and low home care costs (0.2% of total) suggest underuse of home
care and room to shift from acute to preventive care. More attention to
healthcare management of chronic bronchitis and emphysema is suggested, and
improving inhaler and anti-smoking compliance might be important targets.
PMID- 10783931
TI - Assisted pressure control ventilation via a mini-tracheostomy tube for
postoperative respiratory management of lung cancer patients.
AB - Assisted pressure control ventilation (PCV) via a min-tracheostomy tube (MTT) was
conducted to improve gas exchange and reduce the work of breathing of lung cancer
patients after surgery. Thirty-two patients with lung cancer underwent lobectomy
and were managed postoperatively by assisted PCV via an MTT. On the basis of a
simulation study using a lung model for clinical use, we set the inspiratory
pressure to 20 cmH2O and inspiratory time to 1.0 sec to produce a 450-ml
supported volume via the MTT per breath. The blood gases and respiratory rate of
each patient were measured under three sets of conditions: PCV via an MTT
transtracheal oxygenation (TTO) via an MTT and a Venturi face mask with the same
FiO2. After PCV via an MTT overnight, the blood gases in the room air were
measured 2.5 h after withdrawing PCV. In order to determine the effect of PCV via
an MTT on gas exchange after PCV withdrawal, 32 other age and sex-matched lung
cancer patients, who had undergone lobectomy and oxygenation via a face mask
alone after surgery, were used as historical controls. The simulation study
showed that the ventilated volume provided by assisted PCV via an MTT was about
half that provided via a conventional endotracheal tube, even in the presence of
air leakage. The clinical application showed that the ventilated volume obtained
with the PCV via an MTT was significantly higher than that with spontaneous
breathing (P<0.001). PCV via an MTT increased the PaO2 and reduced both the PaCO2
and respiratory rate significantly in comparison with TTO via an MTT and a face
mask (P<0.001). After PCV withdrawal the morning after surgery, the PaO2 of the
PCV group was significantly higher than that of the historical controls
(P<0.001). No postoperative pulmonary complications were observed in either the
PCV or the control groups, however. In addition, no complications or morbidity
were seen related to either MTT insertion or PCV via an MTT. Assisted PVC via an
MTT increased the tidal volume, improved the gas exchange, reduced the
respiratory rate by providing adequate ventilatory support and increased the
PaO2, even after withdrawal following lung surgery. Even though we did not
observe any benefit of clinical outcome with PCV via an MTT in the present study,
this procedure appears to be a potentially useful respiratory management modality
for patients with high risk of postoperative pulmonary complications.
PMID- 10783932
TI - Frequency dependence of compliance in the evaluation of patients with unexplained
respiratory symptoms.
AB - Frequency dependence of compliance (FDC) reflects non-homogeneous ventilatory
distribution and, in the presence of a normal measured airway resistance,
suggests peripheral airways dysfunction. This study evaluated peripheral airway
function and bronchial reactivity in irritant exposed or non-exposed individuals
with normal routine pulmonary function tests (PFTs) who had persistent
unexplained lower respiratory symptoms. Twenty-two patients were identified with
persistent respiratory symptoms and with normal chest X-ray and PFTs. Twenty were
non-smokers; two had stopped smoking more than 10 years before evaluation. Twelve
patients had been exposed to irritants in their workplaces or at home. Non
specific bronchial hyper-reactivity (nsBHR) and FDC, pre- and post
bronchodilator, were measured in all patients. Studies were repeated in 6/12
irritant-exposed subjects after exposure removal and inhaled corticosteroid
treatment. Whereas 12/22 patients had nsBHR, all 22 subjects demonstrated FDC
[dynamic lung compliance/static lung compliance Cdyn,1 / Cst,1 at respiratory
frequency 60 min(-1) (f60), mean 46%, range 27-67%]. After bronchodilator
administration, a 15% improvement Cdyn,1 was observed most consistently at f60
(mean% improvement 26%, 95% CI 14-38%) and in subjects without nsBHR. However,
Cdyn,1 at f60 did not return to normal after inhaled bronchodilator. Irritant
exposed and unexposed individuals appeared similar in results of testing for FDC
and nsBHR. FDC and its response to bronchodilators provide objective
physiological measures of an airway abnormality which may provide a basis for
clinical symptoms in patients with normal routine pulmonary function studies. The
presence of persistently abnormal FDC after bronchodilator (BD) and on follow up
studies may reflect chronic inflammatory and/or structural changes in the airways
in addition to bronchoconstriction.
PMID- 10783933
TI - Osseous disease in patients with pulmonary sarcoidosis and musculoskeletal
symptoms.
AB - Little is known about the clinical manifestations and correlates of osseous
sarcoidosis and few data exist to guide pulmonologists in their evaluation of
patients for possible osseous involvement. To determine the relationship between
pulmonary and osseous sarcoidosis, and to develop an algorithm for use by
pulmonologists in assessing patients with suspected osseous sarcoidosis, we
conducted a retrospective, case control study of patients with pulmonary
sarcoidosis and musculoskeletal complaints who were evaluated for osseous
disease. All patients underwent a standard evaluation to include physical
examination, chest radiograph (CXR), spirometry (PFTs), bone scintigraphy and
plain radiographs of the hands and feet. Patients completed a health assessment
questionnaire and serum angiotenisin converting enzyme, erythrocyte sedimentation
rate, and C-reactive protein were measured. Patients eventually diagnosed with
osseous sarcoidosis were compared to those lacking osseous involvement. Osseous
involvement in patients with pulmonary sarcoidosis and musculoskeletal symptoms
was common and seen in 38.9% of subjects. Patients with osseous sarcoidosis were
more likely to concomitantly suffer from cutaneous sarcoidosis and to have
elevated ACE levels and ESRs. No measure of pulmonary involvement (CXR stage,
PFTs or symptoms) differentiated patients with osseous sarcoidosis from those
without this condition. In cases of osseous sarcoidosis, bone scintigraphy
identified a mean of four sites of osseous involvement, some of which would have
been missed with the use of plain radiographs limited to the hands and feet. We
conclude that in patients with pulmonary sarcoidosis who have significant
musculoskeletal complaints, osseous involvement is frequent. Pulmonary features
of sarcoidosis do not differ between patients with and without osseous disease.
Bone scintigraphy aids in the evaluation of these patients.
PMID- 10783934
TI - Lung volume and its correlation to nocturnal apnoea and desaturation.
AB - The cross-sectional area of the upper airway is known to be lung volume
dependent. If, and to what extent, lung volume variables correlate to nocturnal
obstructive apnoeas and oxygen desaturations independently of other factors known
to affect lung volumes and sleep disordered breathing is still unclear. A total
of 92 subjects were examined by ambulatory recording of nocturnal obstructive
apnoeas and desaturations. Sixty-nine of the subjects had a history of snoring
and 23 were healthy subjects without complaints of snoring and daytime
sleepiness. All subjects performed static and dynamic spirometry for measurements
of lung volumes. To evaluate the correlation between lung volume variables and
apnoea index (AI) and oxygen desaturation index (ODI), simple and multiple
regression analysis was performed. Expiratory reserve volume (ERV) was found to
be lower in subjects with snoring and apnoeas (ERV = 1.0 l) than in non-snoring
subjects (ERV = 1.7 l), (P<0.001). Forced expiratory volume in 1 sec (FEV1)/vital
capacity (VC) was slightly, but significantly (P = 0.031), lower in subjects with
snoring and nocturnal apnoeas and desaturations. In the multiple regression
analysis ERV was found to be independently correlated to both AI (R2=0.13;
P=0.001) and ODI (R2 = 0.11; P = 0.002). Multiple regression analysis also
revealed that ERV, body mass index (BMI) and habitual smoking together accounted
for 43% of the variation in AI and 48% of the variation in ODI. We find a
significant independent association between ERV and nocturnal obstructive apnoea
and oxygen desaturation frequency. Our results indicate that ERV is correlated to
these events to a similar extent, as is obesity.
PMID- 10783935
TI - Prevalence and mechanisms of diurnal hypercapnia in a sample of morbidly obese
subjects with obstructive sleep apnoea.
AB - It is well known that obstructive sleep apnoea is especially frequent in the
morbidly obese. In these subjects diurnal chronic hypercapnia, whose mechanism is
still debated, may be present. Our study was performed to evaluate the prevalence
and the mechanism of diurnal hypercapnia in the morbidly obese affected by
obstructive sleep apnoea. From a population referred to our centre because of
suspicion of sleep related breathing disorders, we selected 285 subjects without
cardiopulmonary, neuromuscular or endocrinological diseases: 89 (36 M and 53 F,
aged 46+/-13 years) had body mass index (BMI) > or = 40 kg m(-2) (MO group:
morbidly obese subjects) and 196 (99 M and 97 F, aged 48+/-16 years) had BMI <40
kg m(-2) (NMO group: non-morbidly obese subjects). Then the MO group was divided
into three subgroups: normocapnic subjects without obstructive sleep apnoea,
normocapnic subjects with obstructive sleep apnoea, hypercapnic subjects with
obstructive sleep apnoea; while we found no hypercapnic subject without
obstructive sleep apnoea. All subjects underwent anthropometric evaluations and
bioelectrical impedance analyses, respiratory function tests and arterial blood
gas analysis, a modified version of the Sleep and Healthy questionnaire and a
full night polysomnography. Our results showed that hypercapnia (PaCO2 > or = 45
mm Hg) associated with obstructive sleep apnoea [respiratory disturbance index
(RDI) > or = 10 h(-1)] was found in 27% of the morbidly obese subjects, but only
in 11% of the nonmorbidly obese ones (P<0.01). The comparison among the three
subgroups, in which we divided the morbidly obese subjects, shows that those with
hypercapnia and obstructive sleep apnoea had significantly more important
ventilatory restrictive defects [forced vital capacity (FVC)% of pred 73.27+/-14
81 vs. 82.37+/-16.93 vs. 87.25+/-18.14 respectively; total lung capacity (TLC)%
of pred 63.83+/-16.35 vs. 79.11+/-14.15 vs. 87.01+/-10.5], a significantly higher
respiratory disturbance index (RDI 46.34+/-26.90 vs. 31.79+/-22.47 vs. 4.98+/
3.29) a longer total sleep time with oxyhaemoglobin saturation<90% [total
sleeptime (TST)SaO2<90% 63.40+/-33.86 vs. 25.95+/-29.34 vs. 8.22+/-22.12] and a
lower rapid eye movement (REM) stage (9.5+/-1.2 vs. 14.0+/-0.9 vs. 17.05+/-1.2)
than normocapnic subjects with obstructive sleep apnoea or subjects without
obstructive sleep apnoea. The best model to predict PaCO2 resulted from a
combination of TSTSaO2<90% (r2 = 0.22, P<0.001), forced expiratory volume in 1
sec (FEV1)% of pred (r2 = 0.09, P<0.01), FVC % of pred (r2 = 0.075, P<0.01). In
conclusion our study suggests that diurnal hypercapnia is frequently associated
with obstructive sleep apnoea in the morbidly obese without chronic obstructive
pulmonary disorder (COPD) and that ventilatory restriction and sleep related
respiratory disturbances correlate to diurnal hypercapnia.
PMID- 10783936
TI - The economic impact of asthma and chronic obstructive pulmonary disease (COPD) in
Sweden in 1980 and 1991.
AB - This study was carried out to estimate the direct and indirect costs associated
with asthma and chronic obstructive pulmonary disease (COPD) in Sweden in 1980
and 1991, and to identify trends in the use of outpatient care, drugs and
inpatient care, and the development of temporary morbidity, permanent disability
and mortality for asthma and COPD. Routinely published administrative and
population data were used to estimate the costs of asthma and COPD, and these
figures were compared to corresponding estimates and trends for all respiratory
diseases as well as for all diseases. Asthma and COPD each accounted for about
SEK 3 billion, together roughly 2% of the economic cost of all diseases. Although
the total costs associated with each disease were similar, the distribution of
the different cost components and changes in each component over time differed.
During the 1980s, the cost of drugs and out-patient care increased for both
diseases. The cost of inpatient care for asthma decreased, whereas that for COPD
increased. This study shows that asthma therapy has changed from inpatient to
ambulatory care in Sweden, while the treatment of COPD to a higher degree still
is based on inpatient care.
PMID- 10783937
TI - Physiological and symptom determinants of exercise performance in patients with
chronic airway obstruction.
AB - To evaluate the physiological and symptom determinants of exercise performance
(EP) as measured by a 6-min walking test (6MWD), Watt(max), and peak oxygen
consumption (VO2 ml/min/kg), 105 patients with chronic airway obstruction (CAO)
[50 chronic obstructive pulmonary disease (COPD): 44 men, aged 63+/-7 years,
forced expiratory volume in 1 sec (FEV1) forced vital capacity (FVC)(-1)% 54+/
13; and 55 asthmatic: 23 men, aged 55+/-10 years, FEV1 FVC(-1) % 65+/-10]
underwent evaluation of 6MWD, symptom limited cyclo-ergometer exercise test,
spirometry, respiratory muscle function, arterial blood gases and sensation of
dyspnoea [using the Borg scale, Visual Analogue Scale (VAS) and Baseline Dyspnoea
Index (BDI)]. A hierarchical method of analysis identified the residual volume
(RV), total lung capacity (TLC)(-1) ratio, BDI and the patient's age as the
strongest and most consistent correlates of EP (r2 = 0.14-0.21). The correlation
between EP and its various determinants was not influenced by diagnosis. The
relationship between breathlessness and EP was different between men and women:
at any given level of exercise, women were more breathless than men. In
multivariate analyses that contained both RV TLC(-1) and BDI, the RV TLC(-1)
ratio was the strongest correlate of EP, although the BDI remained a significant
covariate. Overall, age was the major determinant of EP but inclusion of the RV
TLC(-1) ratio and the BDI into the model explained a further 9-15% of the
variance in EP. These three covariates together explained 26-34% of the variance
between patients. We conclude that in stable CAO patients, the prediction of
exercise capacity by anthropometric, demographic, clinical and physiological
variables is likely to be low. Age, pulmonary hyperinflation and dyspnoea are the
strongest and most consistent correlates of impaired exercise performance.
Airways obstruction, measured during expiration using FEV1, does not appear to be
a predictor of physiological impairment. These results underline the importance
of performing exercise evaluation in CAO patients.
PMID- 10783938
TI - The expression of lymphocyte surface antigens in bronchial biopsies,
bronchoalveolar lavage cells and blood cells in healthy smoking and never-smoking
men, 60 years old.
AB - In this study we investigated if smoking subjects with a normal or slightly
decreased lung function differ in the lymphocyte pattern compared to never
smokers. In a group of 'healthy' smokers (n = 58) and never-smokers (n = 34) 60
years old, we investigated the lymphocyte pattern in both BAL (n = 30 and n = 18
respectively), bronchial epithelium and lamina propria (n = 14 and n = 10
respectively) and blood. We found that all subjects, despite smoking history, had
a higher number of CD8+ cells per mm2 in the epithelium compared to the lamina
propria in the bronchial biopsies. In smokers, these CD8+ cells were
significantly negatively correlated to FEV1 (r = -0.56, P = 0.04). In smokers,
the number of CD8+ lymphocytes was higher and the T cell activation markers
(CD57+ and CD28+) were lower in BAL, than in never-smokers. This last finding was
also seen in blood for CD3+ 57+. We conclude, that in 'healthy' smokers the
lymphocyte patterns are different compared to never-smokers, to some extent in
BAL. There is also a relation between lymphocytes in the bronchial mucosa and
lung function. This has previously been shown in patients with chronic
obstructive pulmonary disease (COPD) and chronic bronchitis but not in
asymptomatic smokers.
PMID- 10783939
TI - Assessing health status and quality of life in idiopathic pulmonary fibrosis:
which measure should be used?
AB - Many studies conducted on the health status and quality of life (QOL) of patients
with certain chronic diseases have demonstrated that their disease had an impact
on their lives. However, less is known about the QOL and health status of
patients suffering from idiopathic pulmonary fibrosis (IPF). In the present
study, three focus groups of IPF patients (n=10) were run to identify the aspects
of QOL or health status that are relevant to this population and to establish
which measure is preferable to assess these aspects. The patients completed and
discussed the St. George's Respiratory Questionnaire (SGRQ) and the World Health
Organization Quality of Life assessment instrument (WHOQOL-100). Results
indicated that hobbies/leisure activities, mobility, transport, social
relationships, working capacity, energy and doing things slower were aspects
relevant to IPF patients' QOL. The WHOQOL-100, with an additional social support
questionnaire, appeared to be preferable.
PMID- 10783940
TI - Impact of patient education and self-management on morbidity in asthmatics and
patients with chronic obstructive pulmonary disease.
AB - The effect of patient education on morbidity in asthmatics and COPD patients has
not previously been investigated in a single study. We randomized 78 asthmatics
and 62 COPD patients after ordinary outpatient management. Intervention consisted
of educational group sessions and individual sessions administered by a trained
nurse and physiotherapist. A self-management plan was developed. The utilization
of health resources and absenteeism from work was self-reported monthly. During
the 12-month follow-up, approximately two (P= 0.001) and three (P= 0.001) times
as many uneducated asthmatics and COPD patients, respectively, visited their
general practitioner (GP) compared with educated. The mean reduction in GP
consultations for the educated were 73% (P<0.001) and 85% (P<0.0001) for the
asthma and COPD group, respectively, compared with uneducated. Fifty percent of
uneducated asthmatics reported absenteeism from work compared with 24% of the
educated (P = 0.06). The mean reduction in days offwork for the educated was 69%
(P = 0.03), compared with uneducated. A positive correlation was observed between
St George's Respiratory Questionnaire total score and number of GP visits for
both the asthma and COPD group (P < 0.001). We conclude that patient education in
asthmatics and COPD patients reduced the need for GP visits and kept a greater
proportion of patients independent of their GP. Patient education among
asthmatics also reduced the number of days off work and appeared to increase the
proportion of patients not reporting absenteeism from work at all. Increasing
number of GP visits was correlated with decreased health-related quality of life
as measured by the SGRQ for both the asthmatics and the COPD patients.
PMID- 10783941
TI - Asthma and airway hyper-responsiveness in adults who required hospital admission
for bronchiolitis in early childhood.
AB - Viral respiratory infections in infancy may contribute to the development of
airway hyper-responsiveness (AHR) in childhood but their effects on respiratory
function at the adult age are still uncertain. A group of 42 subjects aged 17-35
with a pediatrician-made diagnosis of severe bronchiolitis in infancy (Br) were
compared for the presence of asthma and AHR to a control group (C) paired for age
and gender, without evidence of lower respiratory disease in infancy. All had a
respiratory and environmental questionnaire, allergy skin prick tests, blood
eosinophil count, total serum IgE determination and measurements of expiratory
flows and airway response to methacholine. In Br and C groups, respectively, 38
and 12% of subjects had a physician-made diagnosis of asthma, 26 and 7% used
bronchodilators and 12 and 0% an inhaled corticosteroid; 71 and 67%,
respectively, were atopic, 50 and 24% were smokers and 43 and 17% had a first
degree relative with asthma. Mean baseline FEV1 and FEV1/FVC ratio were lower in
the Br than in the C group, with 94/103% (P=0.002) and 80/87 (P<0.0001) of the
predicted value, respectively. Geometric mean PC20 methacholine was significantly
lower in the Br than in the C group 3.9/20.3 mg ml(-1) (P<0.0001). Mean blood
eosinophil count and serum IgE levels were similar in both groups (P> 0.05). In
conclusion, asthma and AHR were found more frequently in young adults with a past
history of bronchiolitis, suggesting that this type of respiratory infection may
contribute to altered pulmonary function in adulthood, although it may also
represent an early manifestation of asthma. The influence of potential
confounding factors, such as familial predisposition and exposure to cigarette
smoke on the development of asthma and AHR in the Br group, cannot be excluded.
PMID- 10783942
TI - Diagnosis of vitreoretinal adhesions in macular disease with optical coherence
tomography.
AB - PURPOSE: To compare the relative incidence of vitreoretinal adhesions associated
with partial vitreous separation within the macula diagnosed with optical
coherence tomography (OCT) with that of those diagnosed with biomicroscopy.
METHODS: The authors obtained linear cross-sectional retinal images using OCT in
patients with selected macular diseases. Additional studies included
biomicroscopy, fundus photography, fluorescein angiography, and B-scan
ultrasonography. RESULTS: Optical coherence tomography was performed on 132 eyes
of 119 patients. Vitreoretinal adhesions within the macula were identified using
OCT in 39 eyes (30%) with the following diagnoses: idiopathic epiretinal membrane
(n = 13), diabetic retinopathy (n = 7), idiopathic macular hole (n = 7), cystoid
macular edema (n = 7), and vitreomacular traction syndrome (n = 5). Biomicroscopy
identified vitreoretinal adhesions in only 11 eyes (8%). Two distinct
vitreoretinal adhesion patterns were identified with OCT, each associated with
partial separation of the posterior hyaloid face: focal (n = 25) and multifocal
(n = 14). CONCLUSIONS: Optical coherence tomography is more sensitive than
biomicroscopy in identifying vitreoretinal adhesions associated with macular
disease.
PMID- 10783943
TI - Surgical treatment for severe diabetic macular edema with massive hard exudates.
AB - PURPOSE: Massive diabetic macular exudates respond poorly to conventional laser
treatment. The purpose of this study was to analyze the surgical results of eyes
with massive hard exudates secondary to diabetic macular edema treated with
combined pars plana vitrectomy, posterior hyaloid removal, focal endolaser
treatment, and panretinal photocoagulation. METHODS: The author retrospectively
analyzed the surgical outcome of 13 consecutive eyes (11 patients) with massive
diabetic macular exudates. All patients had had at least one session of focal
and/or grid laser treatment without any effect. Pars plana vitrectomy, posterior
hyaloid removal, focal macular endolaser treatment, and intraoperative panretinal
photocoagulation were performed. Postoperative visual acuity, evolution of
macular edema, and hard exudates were recorded. RESULTS: All 13 eyes showed
significant decreases in macular edema and hard exudates, a process that became
clinically obvious 3 months after the operation. Eleven eyes had improved vision
of at least two lines during an average follow-up period of 14.8 months.
Intraoperative and postoperative complications included angle closure glaucoma
(one eye), persistent vitreous hemorrhage (two eyes), choroidal detachment (one
eye), intravitreal fibrin formation (one eye), epiretinal membrane formation (one
eye), and neovascular glaucoma (one eye). CONCLUSION: Combined surgery may offer
an opportunity for improvement of vision and reduction of massive macular
exudates in patients with severe diabetic macular edema.
PMID- 10783944
TI - Resolution of diabetic macular edema after surgical removal of the posterior
hyaloid and the inner limiting membrane.
AB - PURPOSE: To evaluate the surgical results of pars plana vitrectomy with peeling
of the inner limiting membrane (ILM) in a preliminary series of 12 eyes with
diffuse diabetic macular edema. PATIENTS AND METHODS: Pars plana vitrectomy with
peeling of the ILM was performed in 12 eyes with diffuse diabetic macular edema.
In 10 eyes, the posterior hyaloid was attached and thickened. Six eyes had
undergone macular photocoagulation previously, and two other eyes had been
vitrectomized previously. Light and electron microscopy of the specimens obtained
during vitrectomy was performed. Visual acuity and retinal thickening were
monitored. RESULTS: Intraoperatively, the posterior hyaloid was found to be
thickened and completely attached to the macula in 10 eyes. Two previously
vitrectomized eyes showed a glistening reflex of the vitreoretinal interface but
no premacular membrane. The posterior hyaloid and the ILM were removed from the
macula. Postoperatively, retinal thickening resolved or decreased in all eyes.
Visual acuity improved by at least two lines in 11 eyes. Best-corrected
postoperative visual acuity developed within 4 to 12 weeks. No recurrence or
deterioration of macular edema or epiretinal membrane formation were observed
during the entire period of review (mean, 16 months; range, 8-31 months). Light
and electron microscopy showed the presence of the ILM associated with sparse and
mostly single-layered fibrous astrocytes. CONCLUSION: Vitrectomy including
removal of the ILM leads to expedited resolution of diffuse diabetic macular
edema and improvement of visual acuity without subsequent epiretinal membrane
formation. Complete release of tractional forces and inhibition of
reproliferation of fibrous astrocytes seem to be prudent in the eyes of patients
with diabetes and advanced vitreoretinal interface disease of the macula.
PMID- 10783945
TI - ICGA-guided laser photocoagulation of occult choroidal neovascularization in age
related macular degeneration. Indocyanine green angiography.
AB - PURPOSE: To evaluate the efficacy of indocyanine green angiography (ICGA)-guided
laser photocoagulation in eyes with fluorescein angiographic evidence of occult
choroidal neovascularization (O-CNV) in patients with age-related macular
degeneration (ARMD) with or without pigment epithelium detachment (PED). METHODS:
Eighty eyes of 79 consecutive patients with O-CNV underwent laser treatment of a
clearly outlined extrafoveal ICGA hyperfluorescent area, presumed to be focal
CNV. Four types of presumed CNV were treated: Group 1 (20 eyes), CNV beneath the
PED; Group 2 (23 eyes), CNV at the margin of the PED; Group 3 (10 eyes),
parapapillary CNV and PED; and Group 4 (27 eyes), macular CNV without PED. Median
follow-up was 17.5 months (range, 6-24 months). RESULTS: After 1 year, 15% of the
eyes in Group 1, 30% in Group 2, 100% in Group 3, and 52% in Group 4 had
obliteration of the presumed CNV. After 1 year, visual acuity was stable or
improved in 18% of Group 1, in 37.5% of Group 2, in 100% of Group 3, and in 73%
of Group 4. The remaining eyes worsened. CONCLUSIONS: Indocyanine green
angiography-guided laser treatment may improve or stabilize visual acuity in some
eyes with O-CNV. The best outcome is seen in eyes with presumed parapapillary
CNV, probably made up of choroidal telangiectases in many cases. The type and
location of the presumed CNV influence prognosis after laser treatment
considerably. A randomized, controlled clinical study appears necessary to
investigate the efficacy of ICGA-guided laser treatment in different types of
presumed CNV. The inclusion criteria for further trials need to be defined with
precision, as data from patients with different choroidal vascular abnormalities
have been pooled until now.
PMID- 10783946
TI - ICGA-guided laser photocoagulation of feeder vessels of choroidal neovascular
membranes in age-related macular degeneration. Indocyanine green angiography.
AB - PURPOSE: To report the ability of indocyanine green angiography (ICGA) with a
confocal scanning laser ophthalmoscope (SLO) to identify feeder vessels of
choroidal neovascular membranes (CNVM) secondary to age-related macular
degeneration (ARMD) and to show the feasibility of inducing complete closure of
the CNVM by photocoagulation targeted exclusively to the feeder vessels. METHODS:
Five consecutive patients with exudative ARMD in whom ICGA with the confocal SLO
showed extrafoveal feeder vessels supplying choroidal neovascular nets had laser
photocoagulation done only to the feeder vessels. In two patients, two separate
membranes were seen. RESULTS: Laser photocoagulation resulted in closure of the
feeder vessels and the CNVM in four patients. Complete closure was achieved with
one treatment in one patient and with two treatments in three patients. In one
patient, two treatments failed to close the feeder vessel and the CNVM, but a
third, more intense laser treatment resulted in temporary closure of the feeder
vessel and CNVM, which recanalized 2 to 4 weeks later with development of a large
rip in the retinal pigment epithelium. In one patient, two separate CNVMs grew
from the edge of the laser scars, but they were not directly related to the
original CNVM and its feeder vessel, and were treated successfully. The same eye
later developed subfoveal occult CNVM with gradual deterioration of visual
acuity. In the other four patients, visual acuity improved in two and was
unchanged in two. CONCLUSIONS: Indocyanine green angiography with the confocal
SLO can identify choroidal feeder vessels supplying CNVM secondary to ARMD. Laser
treatment to such extrafoveal feeder vessels, particularly in membranes that are
large or subfoveal, may be effective in closing the feeder vessel and CNVM with
preservation of the fovea and central vision. More than one treatment may be
required, however, and failures and complications may be expected with this
treatment modality.
PMID- 10783947
TI - Characterization of reactivation of cytomegalovirus retinitis in patients healed
after treatment with highly active antiretroviral therapy.
AB - PURPOSE: To delineate the immune parameters associated with reactivation of
cytomegalovirus (CMV) retinitis in patients for whom highly active antiretroviral
therapy (HAART) was not successful. METHODS: Prospective, longitudinal
observational study of a cohort of 102 patients with CMV retinitis treated with
HAART and being followed up at the AIDS Ocular Research Unit of the University of
California, San Diego from November 1995 to November 1998. The study included
serial clinical and fundus photographic examinations with CD4 T-lymphocyte counts
and HIV viral load measurements. RESULTS: Forty-seven of the 102 patients with
CMV retinitis responded to HAART. Thirty-five of the patients were successfully
withdrawn from anti-CMV therapy. During a median follow-up of 74.71 weeks (range,
4.86-144 weeks) after discontinuation of anti-CMV therapy, four patients
experienced a reactivation of CMV retinitis. In each case, the CD4 count
decreased before reactivation to a median of 31.5 cells/mm3 (mean, 31.25
cells/mm3; range, 23-39 cells/mm3). The association between the CD4 count
decreasing to less than 50 cells/mm3 and reactivation of CMV retinitis was
statistically significant (P < 0.0003). CONCLUSION: Four patients treated with
HAART experienced reactivation of CMV retinitis as their CD4 count decreased. The
threshold CD4 count below which reactivation of CMV retinitis occurred in
patients for whom HAART was not successful appeared to be 50 cells/mm3. Despite
an initial response to HAART, patients are still at risk for reactivation of CMV
retinitis if their CD4 count decreases to less than 50 cells/mm3. The HIV viral
load did not appear to predict CMV reactivation.
PMID- 10783948
TI - Anatomic results and complications in a long-term follow-up of pneumatic
retinopexy cases.
AB - BACKGROUND: The use of pneumatic retinopexy is controversial because 1)
intraocular gas could increase the risk of proliferate vitreoretinopathy and 2)
it has been reported to achieve low rates of success after a single procedure.
METHODS: A total of 219 consecutive cases of SF6 pneumatic retinopexy were
reviewed retrospectively. The follow-up period ranged from 2 to 5 years. RESULTS:
A total of 179 (81.73%) of 219 eyes were treated successfully with a single
procedure. The success rate increased with reoperations to 98.89%. Preoperative
factors related to primary failure or redetachment were aphakia or pseudophakia
(P = 0.0058) and breaks localized on horizontal meridia (P = 0.0305). Cryopexy
was significantly associated with failure (P = 0.0007). A total of 31.05% of eyes
showed early complications. The most frequent incidence was delay in subretinal
fluid reabsorption (36.76%), followed by new breaks (26.47%). Late complications
were observed in 6.84% of the eyes (six eyes with macular pucker, three with new
retinal detachments, three with cataracts, and three with new breaks without
detachment). CONCLUSIONS: Failures of pneumatic retinopexy were related to lens
status, localization of the break, and cryopexy. The occurrence of early and late
complications was similar to that in other procedures.
PMID- 10783949
TI - Improvement of visual acuity over time in patients with bilateral geographic
atrophy from age-related macular degeneration.
AB - PURPOSE: To study the improvement in visual acuity over time in patients with
central scotomas. METHODS: In a prospective natural history study of geographic
atrophy (GA) from age-related macular degeneration (ARMD) with annual follow-up,
36 patients with bilateral GA completed 3 years of follow-up. Protocol visual
acuity (VA) measurements were performed. Scanning laser ophthalmoscopy (SLO) was
performed, and the areas of GA were measured from fundus photographs. RESULTS:
Six eyes of six patients with VA ranging from 20/80 to 20/500 had a VA
improvement of two or more lines (mean, 3.2 lines). This was found only in the
worse-seeing eyes of the patients and was contemporaneous with the deterioration
in VA of the better-seeing eyes. Four of six eyes that improved in acuity had an
improvement in the ability to find and hold the fixation target in an area of
seeing retina, as assessed by SLO at follow-up, and a fifth eye changed from one
fixation site that had little functional retina to another site. CONCLUSIONS:
Spontaneous improvement in VA in eyes with bilateral GA and central scotomas may
occur. It appears to be related to deterioration in VA of the better-seeing
fellow eye and is associated with improvement of fixation in the worse-seeing
eye. The worse-seeing eye of a patient with bilateral ARMD may have the potential
for better vision than measured VA indicates. This finding may have implications
for the choice of patients in treatment trials, for interpretation of long-term
results, and for planning and assessment of low vision intervention.
PMID- 10783950
TI - Fixation patterns of idiopathic macular holes after vitreous surgery.
AB - BACKGROUND: Evaluation of idiopathic macular holes with the scanning laser
ophthalmoscope (SLO) has shown fixation to be located at or near the margin of
the hole and above the horizontal meridian in most cases. However, changes
between preoperative and postoperative fixation have not been well studied.
METHOD: We used SLO microperimetry to determine scotomas and fixation points in
13 patients with idiopathic macular holes before and after vitreous surgery. The
distance between preoperative and postoperative fixation points and the direction
of movement were measured. RESULTS: Preoperatively, fixation was found to be at
or near the margin of the macular hole in all eyes and was located above the
horizontal meridian in most (84.6%) eyes. Postoperatively, there was a shift in
the position of the fixation points. The distance between preoperative and
postoperative fixation correlated with the degree of visual improvement (P =
0.032), but the direction of movement was variable. CONCLUSION: A shift in the
position of fixation occurs after macular hole surgery, and the amount of shift
correlates with visual improvement. From this observation, we define the term
functional macular hole closure, characterized by centripetal movement of the
neurosensory retina and improvement in vision, and the broader term anatomic
macular hole closure, in which apparent hole closure may result from gliosis in
the absence of movement of the neurosensory retina, not associated with visual
improvement.
PMID- 10783951
TI - Macular hole retinal detachment in highly myopic eyes: ultrastructure of
surgically removed epiretinal membrane and clinicopathologic correlation.
AB - PURPOSE: To elucidate the pathogenesis of macular hole retinal detachment (RD) in
highly myopic eyes by investigating the ultrastructure of surgically removed
epiretinal membranes (ERM). METHODS: Five consecutive Japanese patients with
macular hole RD in highly myopic eyes underwent vitrectomy with attempted removal
of the ERM around the hole. The surgical specimens were examined by light
microscopy and by scanning and transmission electron microscopy. RESULTS:
Extremely thin, translucent sheets of epiretinal tissue were harvested from all
patients during surgery, resulting in successful retinal reattachment.
Ultrastructural examination revealed that the ERM consisted of cortical vitreous
and various cellular components. Fibrous astrocytes were the major cell
population and extended cytoplasmic processes with membrane-associated vesicles
onto the cortical vitreous. Gap junctions were observed between the
interdigitating processes of fibrous astrocytes. The cortical vitreous contained
abundant newly formed collagen, including fibrous long-spacing collagen,
surrounded by sparsely distributed native vitreous collagen. CONCLUSIONS: Active
synthesis of new collagen may be regulated by fibrous astrocytes by means of
transmission of metabolic substances through gap junctions and cytoplasmic
vesicles. The frequent occurrence of newly formed collagen aggregates may
subsequently lead to a diffusely condensed posterior cortical vitreous that
exerts tangential traction on the posterior retina, causing macular hole RD.
PMID- 10783952
TI - Familial spastic paraplegia and maculopathy with juxtafoveolar retinal
telangiectasis and subretinal neovascularization.
AB - PURPOSE: To describe a previously unreported condition involving familial spastic
paraplegia and a peculiar type of maculopathy. METHODS: Two pairs of siblings
were studied. All four cases underwent serial clinical examinations, fundus
photography, and fluorescein angiography. Two siblings had extensive
investigations. RESULTS: Characteristics of the four cases include spastic
paraplegia diagnosed in the first decade of life and visual loss at about age 9
due to a maculopathy with an abnormal vascular complex. In the early stages,
parafoveal dilatation of the capillary network was noted. The later stages were
characterized by cystic macular degeneration, and seven of eight eyes developed
fibrovascular scars with retinochoroidal anastomoses, pigment migration, and
atrophic changes. In two siblings, electro-oculographic findings were subnormal,
whereas results of electroretinography, magnetic resonance imaging of the brain
and spinal cord, and metabolic and karyotype studies were normal. These siblings
were an Indonesian girl and boy; the other siblings were white males. There was
no consanguinity of the parents and family history was unremarkable. CONCLUSIONS:
This study suggests that the two pairs of siblings have an identical familial and
probably recessive disorder with neurodegenerative changes that have caused
paraplegia and a peculiar maculopathy associated with anomalous retinal vascular
complexes, retinochoroidal anastomoses, and subretinal neovascularization.
PMID- 10783953
TI - Exudative retinal detachment and retinitis associated with acquired syphilitic
uveitis.
AB - PURPOSE: To describe three cases of exudative retinal detachment and focal
retinitis associated with acquired syphilitic uveitis. METHODS: Three patients
who were referred for evaluation of uveitis were examined. Slit-lamp examination,
ophthalmoscopy, B-scan ultrasonography, fundus photography, and fluorescein
angiography were performed before and after therapy. RESULTS: Each patient had
uveitis with exudative retinal detachment, periphlebitis, and focal retinitis.
Laboratory testing (fluorescent treponemal antibody absorption) revealed positive
serology for active syphilis in all cases. Human immunodeficiency virus antibody
testing was negative in all patients. Retinal detachment resolved in all cases
after treatment with intravenous penicillin. Despite resolution of subretinal
fluid, visual acuity remained poor in eyes in which the macula was detached.
CONCLUSION: Syphilis is a cause of exudative retinal detachment. Antibiotic
therapy can lead to retinal reattachment. Early recognition and treatment may
prevent severe vision loss.
PMID- 10783954
TI - Intravitreal injection of hyaluronidase cannot induce posterior vitreous
detachment in the rabbit.
AB - PURPOSE: To investigate whether intravitreal injection of hyaluronidase can
induce posterior vitreous detachment (PVD) in the rabbit. METHODS: One eye each
of 12 New Zealand white rabbits received intravitreal injection via the pars
plana of 20 IU of hyaluronidase (0.1 mL reconstituted in sterile balanced salt
solution [BSS]) into the midvitreous cavity. The fellow eye of each rabbit
received a vitreous injection of 0.1 mL of BSS. At 3 and 6 months after
intravitreal injection, four and eight rabbits were killed, respectively, and the
eyes were enucleated. After fixation, scanning electron microscopy was performed
to study the vitreoretinal interface. RESULTS: At 3 and 6 months after injection,
scanning electron microscopy showed that the retinal surfaces in eyes that
received either hyaluronidase or BSS were covered with vitreous collagen fibers.
No eyes, even those that received hyaluronidase over a period of 6 months, had
the smooth retinal surface consistent with a bare internal limiting lamina that
suggests the development of PVD. CONCLUSION: Hyaluronidase cannot induce PVD in
the rabbit over a 6-month period after vitreous injection.
PMID- 10783955
TI - Presumed parvovirus B19-associated retinal pigment epitheliopathy.
AB - PURPOSE: To describe a patient with a white dot syndrome associated with acute
erythema infectiosum. METHODS: A patient with a clinical history of erythema
infectiosum and multifocal punctate white lesions at the level of the retinal
pigment epithelium was followed up for an 8-month interval. Serum was tested for
immunoglobulin M (IgM) and IgG antibodies to parvovirus B19 at the time of the
initial evaluation and during convalescence using an indirect immunofluorescence
antibody technique. Serial photographs and fluorescein angiograms were obtained.
RESULTS: IgM and IgG antibodies to parvovirus were detected in the serum at the
time of initial evaluation; IgM antibodies had disappeared but IgG antibodies
persisted in serum obtained at 1-month follow-up. Fundus evaluation revealed
clinical disappearance of some lesions, with increased pigmentation of others
over the course of follow-up. CONCLUSION: The authors have identified an adult
patient who presented with a white dot syndrome associated with acute erythema
infectiosum documented by serologically proved parvovirus B19 infection.
PMID- 10783956
TI - Diagnostic and therapeutic challenges.
PMID- 10783957
TI - Diagnostic and therapeutic challenges.
PMID- 10783958
TI - Local recurrence of choroidal melanoma 13 years after successful xenon arc
photoablation.
PMID- 10783959
TI - Breast cancer metastatic to the choroid in a male patient.
PMID- 10783960
TI - Choroidal metastasis and retinal pigment epithelial tear in a patient with small
cell lung carcinoma.
PMID- 10783961
TI - Diffuse infiltrating retinoblastoma: an inherited case.
PMID- 10783962
TI - Choroidal neovascular membrane: a late complication of inactive Toxocara
chorioretinitis.
PMID- 10783963
TI - Improved visual acuity following pars plana vitrectomy for diabetic cystoid
macular edema and detached posterior hyaloid.
PMID- 10783964
TI - Metallic intraocular foreign body impacted in the retina: 12-year follow-up.
PMID- 10783965
TI - Suprachoroidal gas as a complication of pneumatic retinopexy.
PMID- 10783966
TI - Giant retinal tears after photorefractive keratectomy.
PMID- 10783967
TI - Histopathologic study of presumed parafoveal telangiectasis.
PMID- 10783968
TI - Creating local bibliographic databases: new tools for evidence-based health care.
AB - The Internet has created new opportunities for librarians to present literature
search results to clinicians. In order to take full advantage of these
opportunities, libraries need to create locally maintained bibliographic
databases. A simple method of creating a local bibliographic database and
publishing it on the Web is described. The method uses off-the-shelf software and
requires minimal programming. A hedge search strategy for outcome studies of
clinical process interventions is created, and Ovid is used to search MEDLINE.
The search results are saved and imported into EndNote libraries. The citations
are modified, exported to a Microsoft Access database, and published on the Web.
Clinicians can use a Web browser to search the database. The bibliographic
database contains 13,803 MEDLINE citations of outcome studies. Most searches take
between four and ten seconds and retrieve between ten and 100 citations. The
entire cost of the software is under $900. Locally maintained bibliographic
databases can be created easily and inexpensively. They significantly extend the
evidence-based health care services that libraries can offer to clinicians.
PMID- 10783969
TI - Monograph use at an academic health sciences library: the first three years of
shelf life.
AB - OBJECTIVE: To study the circulation of monographs during the first three years of
shelf life at an academic health sciences library. METHOD: A record was kept of
monographs added to the circulating collection from mid-1994 to mid-1995. After
three years, each monograph was located and the number of times it circulated
during the first, second, and third year of shelf life determined by counting
checkout stamps on the circulation slip. RESULTS: Of the 1,958 monographs
studied, 1,674 had complete data for the first three years of shelf life. Of
those 1,674 titles, 81.48% circulated at least once. A total of 7,659
circulations were recorded; 38.69% occurred in the first year of shelf life,
32.37% in the second year, and 28.95% in the third year. The data did not fit the
well-known 80/20 rule. Instead, approximately 38% of monographs accounted for 80%
of circulation. A small percentage, 2.21%, of monographs accounted for a
substantial percentage of circulation, 21.84%. CONCLUSIONS: A large percentage of
the monographs circulated and use did not decline sharply with age within the
first three years of shelf life, indicating a high demand for monographs at this
academic health sciences library. These results, combined with the findings of
earlier studies, suggested two possibilities. First, academic health sciences
libraries might exhibit use of a higher percentage of monograph acquisitions than
other types of libraries; or, second, a low monograph-to-user ratio might result
in a higher percentage of monographs being used. Perhaps both factors contributed
to the results found in this study. Further investigation would be needed to
determine the extent to which library type and monograph-to-user ratio influenced
monograph use.
PMID- 10783970
TI - A study comparing centralized CD-ROM and decentralized intranet access to
MEDLINE.
AB - OBJECTIVE: The purpose of this study was to evaluate the efficacy of a
decentralized intranet access in each medical department as opposed to
centralized unique MEDLINE access in the medical library. DESIGN: A two-phase
questionnaire to evaluate MEDLINE use was given to junior and senior physicians
at Rouen University Hospital (RUH). Phase I (August-October 1996) corresponded to
a time period when centralized access was the only means of access available and
phase II (August-October 1997) to a time period following the introduction of
decentralized intranet access. RESULTS: A total of 168 physicians filled out at
least one phase of the questionnaire, among whom 123 (73%) filled out both
phases. Use of MEDLINE significantly increased in 1997 (average of 10.2+/-1.1
searches in three months) versus 1996 (average of 4.9+/-0.7 searches in three
months, P<0.0001). The aim of searches changed, becoming significantly more care
oriented in phase II (P<0.0001). The number of searches performed by the
physicians alone increased (P<0.0001) and searches performed by the librarian
decreased (P<0.0001) in phase II. The method of searches also changed, as
searches by author (P< 0.0001), by journal (P = 0.0042), and by free word (P =
0.0027) increased in phase II. Knowledge of the following concepts of MEDLINE
significantly increased: explosion (P<0.0001), scope note (P<0.0001), Abridged
Index Medicus (AIM) journals (P<0.0001), Medical Subject Headings (MeSH)
qualifier (P<0.0001), and focus (P<0.0001). CONCLUSION: A decentralized intranet
access to MEDLINE increased the number of searches and knowledge of this
bibliographic database. MEDLINE intranet access modified the purpose and the
methods of searching.
PMID- 10783971
TI - A two-year experience teaching computer literacy to first-year medical students
using skill-based cohorts.
AB - Because it is widely accepted that providing information online will play a major
role in both the teaching and practice of medicine in the near future, a short
formal course of instruction in computer skills was proposed for the incoming
class of students entering medical school at the State University of New York at
Stony Brook. The syllabus was developed on the basis of a set of expected
outcomes, which was accepted by the dean of medicine and the curriculum committee
for classes beginning in the fall of 1997. Prior to their arrival, students were
asked to complete a self-assessment survey designed to elucidate their initial
skill base; the returned surveys showed students to have computer skills ranging
from complete novice to that of a systems engineer. The classes were taught
during the first three weeks of the semester to groups of students separated on
the basis of their knowledge of and comfort with computers. Areas covered
included computer basics, e-mail management, MEDLINE, and Internet search tools.
Each student received seven hours of hands-on training followed by a test. The
syllabus and emphasis of the classes were tailored to the initial skill base but
the final test was given at the same level to all students. Student
participation, test scores, and course evaluations indicated that this noncredit
program was successful in achieving an acceptable level of comfort in using a
computer for almost all of the student body.
PMID- 10783972
TI - Outreach to public health professionals: lessons learned from a collaborative
Iowa public health project.
AB - In 1995, the National Library of Medicine (NLM) and the Public Health Service
(PHS) recommended that special attention be given to the information needs of
unaffiliated public health professionals. In response, the National Network of
Libraries of Medicine (NN/LM) Greater Midwest Region initiated a collaborative
outreach program for public health professionals working in rural east and
central Iowa. Five public health agencies were provided equipment, training, and
support for accessing the Internet. Key factors in the success of this project
were: (1) the role of collaborating agencies in the implementation and ongoing
success of information access outreach projects; (2) knowledge of the socio
cultural factors that influence the information-seeking habits of project
participants (public health professionals); and (3) management of changing or
varying technological infrastructures. Working with their funding, personnel from
federal, state, and local governments enhanced the information-seeking skills of
public health professionals in rural eastern and central Iowa communities.
PMID- 10783973
TI - Mapping the literature of cytotechnology.
AB - The major purpose of this study was to identify and assess indexing coverage of
core journals in cytotechnology. It was part of a larger project sponsored by the
Nursing and Allied Health Resources Section of the Medical Library Association to
map the literature of allied health. Three representative journals in
cytotechnology were selected and subjected to citation analysis to determine what
journals, other publication types, and years were cited and how often. Bradford's
Law of Scattering was applied to the resulting list of cited journals to identify
core titles in the discipline, and five indexes were searched to assess coverage
of these core titles. Results indicated that the cytotechnology journal
literature had a small core but wide dispersion: one third of the 21,021 journal
citations appeared in only 3 titles; another third appeared in an additional 26
titles; the remaining third were scattered in 1,069 different titles. Science
Citation Index Expanded rated highest in indexing coverage of the core titles,
followed by MEDLINE, EMBASE/Excerpta Medica, HealthSTAR, and Cumulative Index to
Nursing and Allied Health Literature (CINAHL). The study's results also showed
that journals were the predominantly cited format and that citing authors relied
strongly on more recent literature.
PMID- 10783974
TI - The Research Funding Service: a model for expanded library services.
AB - Traditionally, libraries have provided a modest amount of information about
grants and funding opportunities to researchers in need of research funding. Ten
years ago, the University of Washington (UW) Health Sciences Libraries and
Information Center joined in a cooperative effort with the School of Medicine to
develop a complete, library-based grant and funding service for health sciences
researchers called the Research Funding Service. The library provided space,
access to the library collection, equipment, and electronic resources, and the
School of Medicine funded staff and operations. The range of services now
includes individual consultation appointments, an extensive Web site, classes on
funding database searching and writing grant applications, a discussion series
that frequently hosts guest speakers, a monthly newsletter with funding
opportunities of interest to the six health sciences schools, extensive files on
funding sources, and referral services.
PMID- 10783975
TI - Assessing electronic information access and use in long-term care facilities in
north Texas.
PMID- 10783976
TI - Development of a Web-based faculty publications database.
PMID- 10783977
TI - T. Scott Plutchak, twenty-third editor of the Bulletin of the Medical Library
Association.
PMID- 10783978
TI - Biosynthesis of riboflavin in plants. The ribA gene of Arabidopsis thaliana
specifies a bifunctional GTP cyclohydrolase II/3,4-dihydroxy-2-butanone 4
phosphate synthase.
AB - A cDNA segment from Arabidopsis thaliana with similarity to the ribA gene of
Bacillus subtilis was sequenced. A similar gene was cloned from tomato. The open
reading frame of A. thaliana was fused to the malE gene of Escherichia coli and
was expressed in a recombinant E. coli strain. The recombinant fusion protein was
purified and shown to have GTP cyclohydrolase II activity as well as 3,4
dihydroxy-2-butanone 4-phosphate synthase activity. The cognate gene was
amplified by polymerase chain reaction from chromosomal Arabidopsis DNA and was
shown to contain six introns. Intron 4 is located in the region connecting the
GTP cyclohydrolase II and 3,4-dihydroxy-2-butanone 4-phosphate synthase domain of
the putative domains catalyzing the two reaction steps. By comparison with the
bacterial ribA gene, the Arabidopsis gene contains an additional 5' element
specifying about 120 amino acid residues. This segment contains numerous serine
and threonine residues and does not show similarity with other known sequences.
The N-terminal segment is not required for catalytic activity and is likely to
serve as signal sequence for import into chloroplasts.
PMID- 10783979
TI - Biosynthesis of 20-hydroxyecdysone in Ajuga hairy roots: the possibility of 7-ene
introduction at a late stage.
AB - Administration of [3alpha-2H]-3beta-hydroxy-5beta-cholestan-6-one to hairy roots
of Ajuga reptans var. atropurpurea followed by 2H-NMR spectroscopic analysis of
the resulting 20-hydroxyecdysone so formed revealed that the substrate was
efficiently incorporated into the latter. Additionally, [5beta,7alpha,7beta-2H3]
2beta,3beta-dihydroxy-+ ++5beta-cholestan-6-one was converted into 20
hydroxyecdysone. These findings clearly indicate that Ajuga hairy roots are
capable of introducing a double bond at the 7-position at a late stage of 20
hydroxyecdysone biosynthesis, suggesting the possibility of an alternative
biosynthetic pathway which does not involve 7-dehydrocholesterol as an obligatory
intermediate.
PMID- 10783980
TI - Photo-induced synthesis of tomatidenol-based glycoalkaloids in Solanum phureja
tubers.
AB - The effect of light exposure on the steroidal glycoalkaloid content of Solanum
phureja tubers has been investigated and compared with that in domesticated
potato (Solanum tuberosum) tubers. The results indicated that the increase in the
concentration of solanidine-based glycoalkaloids, alpha-solanine and alpha
chaconine was broadly similar in both species. However, in the S. phureja tubers,
light exposure also induced the synthesis of tomatidenol-based glycoalkaloids.
These have been identified as alpha- and beta-solamarine. These glycoalkaloids
were not detected in tubers continually stored in darkness.
PMID- 10783981
TI - Fungicidal activity of natural and synthetic sesquiterpene lactone analogs.
AB - Fungicidal activity of 36 natural and synthetic sesquiterpene lactones with
guaianolide, trans, trans-germacranolide, cis, cis-germacranolide, melampolide,
and eudesmanolide carbon skeletons was evaluated against the phytopathogenic
fungi Colletotrichum acutatum, C. fragariae, C. gloeosporioides, Fusarium
oxysporum, Botrytis cinerea, and Phomopsis sp. Dose-response data for the active
compounds dehydrozaluzanin C, dehydrocostuslactone, 5alpha
hydroxydehydrocostuslacone, costunolide, and zaluzanin C are presented. A new 96
well microbioassay procedure for fast and easy evaluation of antifungal activity
was used to compare these compounds with commercial fungicide standards. Some
structure-activity conclusions are also presented.
PMID- 10783982
TI - Prenylflavonoid variation in Humulus lupulus: distribution and taxonomic
significance of xanthogalenol and 4'-O-methylxanthohumol.
AB - The resins produced by either lupulin or leaf glands of over 120 plants of
Humulus lupulus and one plant of H. japonicus (Cannabinaceae) were analyzed for
the presence of prenylated flavonoids. The H. lupulus taxa investigated were H.
lupulus var. lupulus from Europe, H. lupulus var. cordifolius from Japan, and H.
lupulus from North America. Fifty-two of the plants examined were cultivars of
European, American, and Japanese origin. Twenty-two flavonoids were detected in
the glandular exudates of H. lupulus by HPLC-MS MS. Xanthohumol (3'-prenyl-6'-O
methylchalconaringenin) was the principal prenylflavonoid in all H. lupulus
plants and was accompanied by 11 structurally similar chalcones. Ten flavonoids
were identified as the flavanone isomers of these chalcones. Three other
prenylchalcones were isolated from H. lupulus cv. 'Galena', one of which was
identified as 3'-prenyl-4'-O-methylchalconaringenin (named 'xanthogalenol'). The
distribution of three 4'-O-methylchalcones, i.e. xanthogalenol, 4'-O
methylxanthohumol, and 4',6'-di-O-methylchalconaringenin, was found to be limited
to wild American plants from the Missouri-Mississippi river basin, H. lupulus
var. cordifolius, and most of their descendents. These 4'-O-methylchalcones were
absent from cultivars of European origin, and from wild hops from Europe and
southwestern USA. The flavonoid dichotomy (presence versus absence of 4'-O
methylchalcones) indicates that there are at least two evolutionary lineages
within H. lupulus (European and Japanese American), which is in agreement with
morphological, molecular, and phytogeographical evidence. Leaf glands of H.
japonicus from eastern Asia did not produce the H. lupulus prenylflavonoids.
PMID- 10783983
TI - Biosynthetic studies on the tropane ring system of the tropane alkaloids from
Datura stramonium.
AB - Isotopic labelling experiments have been carried out in Datura stramonium root
cultures with the following isotopically labelled precursors; [2H3]- [2-13C, 2H3]
, [1-13C, 18O2]-acetates, 2H2O, [2H3-methyl]-methionine, [2-13C]-phenyllactate,
[3-2H]-tropine and [2'-13C, 3-2H]-littorine. The study explored the incorporation
of isotope into the tropane ring system of littorine 1 and hyoscyamine 2 and
revealed that deuterium from acetate is incorporated only into C-6 and C-7, and
not into C-2 and C-4 as previously reported. Oxygen-18 was not retained at a
detectable level into the C(3)-O bond from [1-13C, 18O2]-acetate. The
intramolecular nature of the rearrangement of littorine 1 to hyoscyamine 2 is
revealed again by a labelling study using [2'-13C, 3-2H]-littorine, [2-13C]
phenyllactate and [3-2H]-tropine.
PMID- 10783984
TI - Structure and synthesis of ether-linked proteracacinidin and promelacacinidin
proanthocyanidins from Acacia caffra.
AB - Two new ether-linked proanthocyanidins, epioritin-(4beta-->3)-epioritin-4beta-ol
and epimesquitol-(4beta-->4)-epioritin-4beta-ol, were isolated from the heartwood
of Acacia caffra. Their structures and absolute configurations were established
by spectroscopic methods and syntheses.
PMID- 10783985
TI - Structure and synthesis of the first procassinidin dimers based on epicatechin,
and gallo- and epigallo-catechin.
AB - The range of natural dimeric procassinidins is extended by identification of
cassiaflavan-(4alpha-->8)-epicatechin, cassiaflavan-(4alpha 8)-epigallocatechin,
cassiaflavan-(4beta-->8)-epicatechin, cassiaflavan-(4beta-->8)-epigallocatechin,
cassiaflavan-(4beta-->8)-gallocatechin, ent-cassiaflavan-(4beta-->8)-epicatechin
and cassiaflavan-(4alpha-->6)-epicatechin in the bark of Cassia petersiana. Their
structures and absolute configuration were confirmed by synthesis.
PMID- 10783986
TI - Triterpenoids from Tripterygium wilfordii.
AB - The extract (T(II)) of Tripterygium wilfordii Hook f. afforded four
triterpenoids: wilforic acid D (3beta,24-epoxy-2alpha-hydroxy-24R*-ethoxy-29
friedelanoic acid); (E) 3beta,24-epoxy-2-oxo-3alpha-hydroxy-29-friedelanoic acid;
(F) 2beta-hydroxy-3-oxo-friedelan-29-oic acid; 29-hydroxy-3-oxo-olean-12-en-28
oic acid and 17 known triterpenoids. Their structures were established on the
basis of spectroscopic studies. In a bioactivity analysis, only the known
dulcioic acid compound showed a significant inhibitory effect on cytokine
production.
PMID- 10783987
TI - 6-[omega-arylalkenyl]-5,6-dihydro-alpha-pyrones from Cryptocarya moschata
(Lauraceae).
AB - Eleven 6-[omega-arylalkenyl]-5,6-dihydro-alpha-pyrones, cryptomoscatones D2, E1,
E2, E3 and F1 and cryptopyranmoscatones A1, A2, A3, B1, B2 and B4, in addition to
goniothalamin and cryptofolione, were isolated from branch and stem bark of
Cryptocarya moschata, Lauraceae. Their structures were established by
spectroscopic methods.
PMID- 10783988
TI - Symptom control in advanced gastrointestinal cancer.
AB - Patients with advanced gastrointestinal cancer develop many symptoms as the
disease progresses. However, the common problems of pain, nausea and vomiting,
anorexia, constipation and intestinal obstruction can all be relieved by
appropriate pharmacological treatment.
PMID- 10783989
TI - The role of radiotherapy in the palliative treatment of gastrointestinal cancer.
AB - Gastrointestinal malignancy is the second commonest cancer and is associated with
a high mortality. Although definitive surgery could be offered for most tumour
sites in the gastrointestinal tract, the majority of patients will still develop
incurable recurrent or metastatic disease. Therefore, palliation is an important
part of management. Radiotherapy has long been recognized as an effective
palliative modality in gastrointestinal cancer. It was previously offered in
cases where surgical resection was not feasible either due to the advanced nature
of the disease or the presence of metastatic disease. Planning and delivery of
radiation techniques have improved over the years and it is now possible to offer
high-dose radiation to the tumour with acceptable side-effects. The dose of
radiation offered is important to achieve worthwhile palliation. The advent of
high-dose brachytherapy has contributed significantly to the role of radiotherapy
as an effective palliative modality used either alone or as a boost to external
beam radiotherapy. The addition of chemotherapy to radiation has been used in
most tumour sites in the gastrointestinal tract and has been shown to improve the
therapeutic ratio; however, one should be aware of the increased toxicity and
careful selection of patients is necessary. Chemoradiation could help to down
stage locally advanced tumours which are otherwise unresectable. This approach
has led to improved local control in certain tumour sites, e.g. anal canal and
oesophagus. Whether this translates into improvement in survival remains to be
seen. However, with increasing use of multi-modality therapy, increases in
toxicity to the patient and in cost to healthcare providers must be taken into
account.
PMID- 10783990
TI - Palliative chemotherapy in advanced gastrointestinal cancer.
AB - In this review, the role of chemotherapy in the palliative treatment of advanced
gastrointestinal cancer is discussed. Emphasis is placed on chemotherapy-related
problems, current chemo-therapy options, and new developments.
PMID- 10783991
TI - Endoscopic palliation of gastrointestinal malignancy.
AB - In this paper, we review a range of therapeutic options which may be employed at
endoscopy to alleviate the symptoms of gastrointestinal malignancy.
PMID- 10783992
TI - Surgical and interventional palliative treatment of upper gastrointestinal
malignancies.
AB - Malignancies of the upper gastrointestinal tract, including the oesophagus,
stomach, liver, bile ducts and pancreas, are highly virulent diseases. While
curative therapies relieve symptoms caused by these cancers, most of these
treatments prove unsuccessful in the control of tumour due to occult residual
disease. This review covers only planned palliative procedures for these
conditions where patient factors (e.g. performance status or patient wishes) or
tumour factors (e.g. locally advanced or known metastatic disease) prevent
potentially curative intervention. For most patients, palliation of luminal
obstruction, pain or other symptoms is the most worthwhile treatment that can be
offered with present therapies.
PMID- 10783993
TI - Surgical palliation of colorectal cancer.
PMID- 10783994
TI - What should the clinician know about the cytochrome P450 system?
AB - The cytochromes P450 are a superfamily of enzymes which catalyse mono-oxidation,
thus transforming fat-soluble toxins into water-soluble metabolites which are
excreted in urine. Cytochromes P450 are mainly located in the liver, they play a
major role in hepatotoxicity. The toxins (or the drugs) can be in part
transformed into reactive metabolites which destroy intrahepatocytic proteins
(metabolite-related hepatotoxicity) or form an immune complex that induces immune
reactions (immune-related hepatotoxicity).
PMID- 10783995
TI - Effect of L-arginine on lower oesophageal sphincter motility in man.
AB - OBJECTIVE: Inhibitory responses of the lower oesophageal sphincter (LOS) are
mediated via an L-arginine/nitric oxide (NO) pathway. L-arginine is known as the
precursor of NO. We have studied the effect of intravenous L-arginine on LOS
motility in man. DESIGN: Twelve healthy subjects participated in a double-blind,
placebo-controlled randomized study. METHODS: We investigated the effect of
continuous infusion of L-arginine (500 mg/kg body weight/120 min) in six subjects
under fasting conditions. Six other subjects were studied under postprandial
conditions. LOS pressure (LOSP), swallow-induced LOS relaxations and transient
lower oesophageal sphincter relaxations (TLOSR) were measured with sleeve
manometry combined with pH metry. The meal consisted of a carbohydrate-high fat
meal. Blood samples were taken before and after administration of L-arginine or
saline to determine plasma levels of amino acids, cholecystokinin and gastrin.
RESULTS: Plasma levels of arginine and citrulline significantly (P < 0.05)
increased during L-arginine infusion. L-arginine did not affect plasma hormone
levels. Under fasting conditions, LOSP and TLOSR were not influenced by L
arginine. Ingestion of the carbohydrate-high fat meal significantly decreased
LOSP. L-arginine did not significantly influence TLOSR frequency, either under
fasting conditions or postprandially. CONCLUSIONS: These results suggest that in
humans under fasting or postprandial conditions intravenous infusion of L
arginine does not influence LOS motility.
PMID- 10783996
TI - Pantoprazole 20 mg is an effective maintenance therapy for patients with gastro
oesophageal reflux disease.
AB - OBJECTIVES: To compare the efficacy of 20 mg with 40 mg pantoprazole in
maintaining symptomatic and endoscopic remission in patients with gastro
oesophageal reflux disease (GORD). STUDY DESIGN: Patients (18-84 years old; n =
433) with healed GORD II or III were included in this prospective multi-centre,
randomized, parallel, double-blind study. Pantoprazole was administered once
daily for up to 1 year as either a 20 mg or 40 mg enteric-coated tablet to 221
and 212 patients, respectively. Symptoms of GORD were assessed every 3 months.
Endoscopy was performed at entry, after 6 and 12 months, or when symptoms of GORD
were perceived on at least three consecutive days. The primary efficacy parameter
was the time until endoscopically proven relapse of GORD occurred (stage I or
greater); the secondary parameters included tolerability, safety, and time until
symptomatic relapse occurred. RESULTS: In the 20 mg treatment group, 87% and 75%
of patients were in endoscopic remission after 6 and 12 months, respectively; the
corresponding rates in the 40 mg treatment group were 91% and 78%. In both
treatment groups, GORD stage I accounted for about 50% of endoscopic relapses.
The symptomatic remission rates in the 20 mg group were estimated as 85% and 77%
after 6 and 12 months, respectively; the corresponding values in the 40 mg group
were 87% and 76%. No correlation was seen either between the endoscopically
proven relapse and perception of symptoms, or between the severity of the pre
treatment stage of GORD and the maintenance dose of pantoprazole. Both doses were
well tolerated. CONCLUSIONS: Both the 20 mg and 40 mg doses of pantoprazole are
safe and effective in maintaining patients with healed reflux oesophagitis in
remission. Moreover, for the majority of patients, the 20 mg dose provides
adequate long-term therapeutic efficacy at a minimal drug exposure and lower
costs.
PMID- 10783997
TI - Helicobacter pylori eradication therapy: a discrepancy between current guidelines
and clinical practice.
AB - BACKGROUND: Consensus guidelines recommend that patients with peptic ulcer
disease, and other causes of dyspepsia, should be treated with Helicobacter
pylori eradication regimens. However, it has not been firmly established whether
physicians have adapted their practice accordingly. OBJECTIVES: (1) To establish
the proportion of ulcer-healing prescriptions that H. pylori eradication regimens
accounted for, (2) to evaluate the composition of the eradication regimens used,
and (3) to compare the prescribing patterns of specialist and primary care
practitioners. METHODS: Seven community pharmacy practices were identified, and
all prescriptions for individual acid-suppressing agents and eradication regimens
were prospectively evaluated over an initial one-month period. Prospective
documentation and evaluation of eradication regimens only was then continued for
a further three-month period. RESULTS: The prescriptions for 585 patients were
evaluated. Proton-pump inhibitors and H2-receptor antagonists accounted for 261
(44.5%) and 307 (52.5%) of prescriptions respectively. H. pylori eradication
therapy was prescribed for 17 (2.9%) patients in this initial period. Sixty-six
eradication regimens were evaluated over four months: 48/66 (73%) of these were
initiated by primary care practitioners and 18/66 (27%) by specialists. Thirteen
different combinations of antibiotics and acid-suppressing agents were identified
- many of undocumented efficacy. Dual, triple and quadruple regimens accounted
for 15 (23%), 48 (72.5%) and 3 (4.5%) of patient prescriptions respectively.
CONCLUSION: H. pylori eradication therapy currently accounts for a very small
proportion of ulcer-healing medication in clinical practice. Most eradication
regimens are initiated by primary care practitioners. In comparison with
specialist practices, prescriptions from this source are more likely to be of
undocumented efficacy.
PMID- 10784000
TI - Short-acting general anaesthesia facilitates therapeutic ERCP in frail elderly
patients with benign extra-hepatic biliary disease.
AB - AIMS AND OBJECTIVES: To ascertain whether therapeutic endoscopic retrograde
cholangiopancreatography (ERCP) for benign biliary disease in frail elderly
patients with comorbid conditions can be safely undertaken in a district general
hospital, and whether the procedure is facilitated by the use of short-acting
general anaesthesia. SETTING: District general hospital in South East England.
DESIGN OF STUDY: Clinical study of 25 consecutive patients with benign biliary
disease. METHODS: Describes the process of bile duct clearance by therapeutic
ERCP under short-acting general anaesthesia in 25 patients with co-morbidity aged
> or = 80 years and gives details of the general anaesthesia and monitoring.
RESULTS: Twenty-two patients had their bile ducts successfully cleared locally
and one patient was stented for a benign biliary stricture. The ampullae of two
other patients were lying within diverticula, which hindered cannulation and only
pancreatograms were obtained; one of the patients had a successful bile duct
clearance at a tertiary centre, the other refused further intervention.
Complications (melaena, bronchopneumonia and a Clostridium difficile infection)
occurred in two patients (8%). There was no morbidity associated with the
anaesthesia, and no mortality occurred within 30 days of the procedure.
CONCLUSIONS: Bile duct clearance by therapeutic ERCP can be safely carried out in
frail elderly patients in a district general hospital and the process is
facilitated by the use of short-acting general anaesthesia. The importance of
optimizing the patient's condition before ERCP, and not overfilling the
pancreatic duct, is highlighted.
PMID- 10783998
TI - Assessment of the prevalence of infection with Helicobacter pylori in patients
with inflammatory bowel disease.
AB - OBJECTIVE: To determine the prevalence of Helicobacter pylori in patients with
inflammatory bowel disease (IBD) and compare this to the prevalence in a control
population with non-organic bowel symptoms, and to investigate the effect of
sulphasalazine and other 5-aminosalicylic acid (5-ASA) drugs on the prevalence of
H. pylori in IBD patients. DESIGN: Prospective, controlled trial. SETTING:
Gastroenterology out-patient department, City General Hospital, North
Staffordshire Hospitals NHS Trust, Stoke-on-Trent. PARTICIPANTS: The population
comprised 51 patients with ulcerative colitis, 42 patients with Crohn's disease
and 40 patients with irritable bowel syndrome as controls. Patients with X-ray-
and/or biopsy-proven disease were eligible to be entered into the study.
INTERVENTIONS: Subjects filled in a detailed questionnaire, were assessed for
seropositivity of H. pylori and underwent a C13 urea breath test (UBT). MAIN
OUTCOME MEASURES: Seropositivity for H. pylori and a positive C13 UBT result.
RESULTS: A quarter of the irritable bowel syndrome controls were seropositive for
H. pylori. Of the ulcerative colitis patients, 21.6% were currently H. pylori
positive on C13 UBT; 17.6% of the ulcerative colitis patients who had been
previously treated with sulphasalazine were positive while 23.1% of the
ulcerative colitis patients who had been treated with a non-sulphasalazine 5-ASA
drug were positive. Of the Crohn's patients, 11.9% were currently H. pylori
positive; 3.6% of the Crohn's patients who had been previously treated with
sulphasalazine were positive while 12.5% of the Crohn's patients who had been
treated with a non-sulphasalazine 5-ASA drug were positive. CONCLUSIONS: Patients
with IBD and Crohn's disease in particular were less likely to be H. pylori
positive than controls. Sulphasalazine treatment further decreased the prevalence
of H. pylori, although the reduced prevalence of H. pylori in IBD patients could
not be accounted for by this alone.
PMID- 10783999
TI - Transforming growth factor-beta and hepatocyte growth factor plasma levels in
patients with inflammatory bowel disease.
AB - OBJECTIVE: An increased mucosal expression of transforming growth factor-beta
(TGF-beta) and hepatocyte growth factor (HGF) has been reported in patients with
active inflammatory bowel diseases (IBD) and in proximity to injured gastric and
intestinal mucosal surfaces. The aim of this study was to measure systemic
concentrations of TGF-beta and HGF and to assess their potential value to predict
disease activity or severity of inflammation in patients with inflammatory bowel
diseases. DESIGN AND METHODS: Plasma HGF and TGF-beta1 peptide levels were
determined in 29 patients with ulcerative colitis, 45 patients with Crohn's
disease and 28 healthy controls using commercial ELISA assays. Peptide levels
were correlated with disease activity indices and various laboratory parameters.
RESULTS: HGF and TGF-beta1 plasma levels were detected in all control and IBD
subjects. Although a tendency towards increased HGF and TGF-beta1 peptide levels
in IBD patients was observed, differences between groups were not significant In
ulcerative colitis patients HGF plasma levels positively correlated with white
blood cell counts and negatively correlated with serum albumin concentrations and
haematocrit. In Crohn's disease patients, a positive correlation between TGF-beta
and platelet count was observed. CONCLUSIONS: HGF and TGF-beta1 plasma
concentrations are not significantly different in IBD and healthy control
subjects. Stratification of IBD patients according to disease activity did not
reveal any substantial differences, suggesting that HGF and TGF-beta plasma
levels have no value in the assessment of disease activity or severity of
inflammation in patients with IBD.
PMID- 10784001
TI - Neuropeptide Y and peptide YY, but not pancreatic polypeptide, substance P,
cholecystokinin and gastric inhibitory polypeptide, inhibit the glucagon- and
noradrenaline-dependent increase in glucose output in rat liver.
AB - OBJECTIVE: The gastrointestinal peptides neuropeptide Y (NPY), peptide YY (PYY),
pancreatic polypeptide (PP), substance P (SP), cholecystokinin (CCK) and gastric
inhibitory polypeptide (GIP) are released into the portal vein mainly during the
absorptive phase. Their direct actions and their hormone modulatory effects on
liver carbohydrate metabolism were investigated. METHODS: Isolated rat liver,
single-pass-perfused via both the hepatic artery (120 cm H2O, 30% flow) and the
portal vein (20 cm H2O, 70% flow) with a Krebs-Henseleit buffer containing 5 mM
glucose, 2 mM lactate and 0.2 mM pyruvate, NPY (5 nM), PYY (5 nM), PP (5 nM), SP
(100 nM), CCK (100 nM) and GIP (10 nM) was infused for 10 min via either vessel.
In additional experiments, insulin (100 nM), glucagon (1 nM) or noradrenaline (1
microM) were applied for 5 min via the portal vein during a 20 min portovenous
infusion of one of the peptides. RESULTS: Under basal conditions, neither
arterial nor portal NPY, PYY, PP, SP, CCK or GIP modified hepatic glucose and
lactate metabolism. Also, none of the peptides enabled an action of portal
insulin in the normally insulin-insensitive isolated perfused rat liver. NPY and
PYY, but not PP, SP, CCK or GIP, inhibited the increase in glucose release by
glucagon and noradrenaline. Under basal conditions, none of the peptides altered
hepatic flow. Only portal NPY and PYY enhanced slightly the noradrenaline
dependent reduction of portal flow. CONCLUSIONS: NPY, PYY, PP, SP, CCK and GIP do
not act directly as regulators of basal hepatic carbohydrate metabolism. NPY and
PYY act as signal factors of the absorptive phase function as antagonists of the
postabsorptive glucose regulatory hormones glucagon and noradrenaline.
PMID- 10784002
TI - Serum interferon gamma in primary biliary cirrhosis: effect of ursodeoxycholic
acid and prednisone therapy alone and in combination.
AB - BACKGROUND: Interferon-gamma may have immunopathogenic importance in primary
biliary cirrhosis, stimulating aberrant expression on biliary epithelium of class
II major histocompatibility molecules and inter-cellular adhesion molecule-1.
Liver transcripts for interferon-gamma are found in primary biliary cirrhosis.
Its serum level is increased in pretransplantation stages and decreases after
transplantation. OBJECTIVES: (1) To verify whether serum interferon-gamma levels
are increased in non-cirrhotic stages of primary biliary cirrhosis. (2) To
evaluate the effect of ursodeoxycholic acid and prednisone alone and in
combination on serum levels of interferon-gamma and soluble inter-cellular
adhesion molecule-1. METHODS: Nine non-cirrhotic, anicteric patients with primary
biliary cirrhosis (patient test group), 14 healthy, negative controls and 14
positive controls, with chronic hepatitis related to hepatitis C virus were
studied in basal condition. Primary biliary cirrhosis patients were treated with
ursodeoxycholic acid, prednisone and the association of the two drugs for three 4
week periods, each period separated by a 4-week wash-out. Interferon-gamma and
soluble inter-cellular adhesion molecule-1 were measured in serum by commercially
available immuno-enzymatic kits. RESULTS: Median interferon-gamma levels were
increased in patients with primary biliary cirrhosis compared with healthy
controls (44 vs 19 pg/ml; P < 0.01) but similar to those in chronic hepatitis
patients (47 pg/ml). Serum soluble inter-cellular adhesion molecule-1 was
significantly reduced by ursodeoxycholic acid, and an even greater reduction was
obtained on addition of prednisone. No treatment affected interferon-gamma
levels. CONCLUSION: Serum interferon-gamma is increased in noncirrhotic patients
with primary biliary cirrhosis, but this is not disease-specific. Neither
ursodeoxycholic acid, nor prednisone, nor the combination of the two drugs
influenced this immunological pathway of primary biliary cirrhosis.
PMID- 10784003
TI - Histological estimation of the efficacy of endoscopic laser coagulation therapy
for diffuse antral vascular ectasia.
AB - We present the case of a 72-year-old woman with successful control of repeated
episodes of bleeding from diffuse antral vascular ectasia (DAVE) by laser
coagulation therapy. In addition to DAVE, the patient also suffered from severe
iron deficiency anaemia (due to recurrent bleeding), liver cirrhosis, and huge
tumours of hepatocellular carcinoma (HCC). She was referred from another hospital
after failure to stop her bleeding episodes. Endoscopic examination revealed
diffuse speckled telangiectasia over most of the stomach (from antrum to the
upper portion of the body) and large numbers of blood clots. The patient had
received repeated blood transfusions, haemostatic drugs, and H2 receptor
antagonists at the other hospital, without improvement of the repeated bleeding.
She underwent three sessions of endoscopic laser coagulation therapy for the
lesions at our hospital after the final diagnosis of DAVE had been made based on
the characteristic histological findings of biopsied specimens. This treatment
improved her general condition and stopped the bleeding from the gastrointestinal
tract even without fasting. Unfortunately, however, her liver function gradually
worsened due to HCC and previous massive bleeding, and she finally died of liver
failure three months after the last laser session. Autopsied specimens obtained
from the patient's stomach revealed that macroscopic diffuse speckled
telangiectasia and microscopic typical vasodilatation in mucosal and submucosal
layers of gastric tissue had disappeared in the treated areas but not all
portions of the DAVE lesion. These histological findings for the treated areas,
in addition to the clinical improvement of bleeding, suggest that endoscopic
laser coagulation therapy may be useful and one of the first choices in treatment
for DAVE.
PMID- 10784004
TI - Prevalence of Helicobacter pylori infection in Hungarian gastroenterologists and
general practitioners.
PMID- 10784006
TI - Transfer of pigeons' matching to sample to novel sample locations.
AB - This study examined the conditions under which conditional stimulus control by
the sample stimuli in three-key matching-to-sample paradigms would generalize
across the different possible sample locations. In Experiments 1 and 2, the
samples appeared on the left and right side keys during initial training and then
on the center key during testing. Transfer of pigeons' matching performances to
the center-key samples was evident after both identity and symbolic matching
training. In Experiment 3, pigeons trained on symbolic matching with two side-key
samples or with a side-key and a center-key sample generally transferred their
learned matching performances to those samples when they subsequently appeared in
the remaining (novel) location. These results indicate that, when two-choice
conditional discriminations are learned with more than one sample location, the
visual characteristics of the sample per se predominantly come to control the
pigeons' comparison choices. This finding encourages the use of the multiple
location training procedure as a way of reducing control by location, thus
providing a more discriminating test of symmetry in animals.
PMID- 10784005
TI - Pigeons may not remember the stimuli that reinforced their recent behavior.
AB - In two experiments the conditioned reinforcing and delayed discriminative
stimulus functions of stimuli that signal delays to reinforcement were studied.
Pigeons' pecks to a center key produced delayed-matching-to-sample trials
according to a variable-interval 60-s (or 30-s in 1 pigeon) schedule (Experiment
1) or a multiple variable-interval 20-s variable-interval 120-s schedule
(Experiment 2). The trials consisted of a 2-s illumination of one of two sample
key colors followed by delays ranging across phases from 0.1 to 27.0 s followed
in turn by the presentation of matching and nonmatching comparison stimuli on the
side keys. Pecks to the key color that matched the sample were reinforced with 4
s access to grain. Under some conditions of Experiment 1, pecks to nonmatching
comparison stimuli produced a 4-s blackout and the start of the next interval.
Under other conditions of Experiment 1 and each condition of Experiment 2, pecks
to nonmatching stimuli had no effect and trials ended only when pigeons pecked
the other, matching stimulus and received food. The functions relating pretrial
response rates to delays differed markedly from those relating matching-to-sample
accuracy to delays. Specifically, response rates remained relatively high until
the longest delays (15.0 to 27.0 s) were arranged, at which point they fell to
low levels. Matching accuracy was high at short delays, but fell to chance at
delays between 3.0 and 9.0 s. In Experiment 2, both matching accuracy and
response rates remained high over a wider range of delays in the variable
interval 120-s component relative to the variable-interval 20-s component. The
difference in matching accuracy between the components was not due to an
increased tendency in the variable-interval 20-s component toward proactive
interference following short intervals. Thus, under these experimental conditions
the conditioned reinforcing and the delayed discriminative functions of the
sample stimulus depended on the same variables (delay and variable-interval
value), but were nevertheless dissociated.
PMID- 10784007
TI - Use of number by crows: investigation by matching and oddity learning.
AB - Hooded crows were trained in two-alternative simultaneous matching and oddity
tasks with stimulus sets of three different categories: color (black and white),
shape (Arabic Numerals 1 and 2, which were used as visual shapes only), and
number of elements (arrays of one and two items). These three sets were used for
training successively and repeatedly; the stimulus set was changed to the next
one after the criterion (80% correct or better over 30 consecutive trials) was
reached with the previous one. Training was continued until the criterion could
be reached within the first 30 to 50 trials for each of the three training sets.
During partial transfer tests, familiar stimuli (numerals and arrays in the range
from 1 to 2) were paired with novel ones (numerals and arrays in the range from 3
to 4). At the final stage of testing only novel stimuli were presented (numerals
and arrays in the range from 5 to 8). Four of 6 birds were able to transfer in
these tests, and their performance was significantly above chance. Moreover,
performance of the birds on the array stimuli did not differ from their
performance on the color or shape stimuli. They were capable of recognizing the
number of elements in arrays and comparing the stimuli by this attribute. It was
concluded that crows were able to apply the matching (or oddity) concept to
stimuli of numerical category.
PMID- 10784008
TI - Acquisition of arbitrary conditional discriminations by young normally developing
children.
AB - Three experiments investigated conditions designed to facilitate acquisition of
arbitrary conditional discriminations in 3- to 6-year-old normally developing
children. In Experiment 1, 6 subjects failed to master the arbitrary match-to
sample task under conditions of differential reinforcement alone, but 7 subjects
did so when instructions or instructions and sample naming were added. In
Experiment 2, sample naming introduced in a blocked-trial arrangement resulted in
acquisition, but only when the sample name was a nonsense syllable provided by
the experimenter (5 of 7 subjects) and not when the sample name was generated by
the subject (0 of 5 subjects). Experiment 3 demonstrated the effectiveness of a
training sequence involving thematically related stimuli as an intermediate step
facilitating the transition from identity to novel arbitrary relations. The
difficulties in mastering arbitrary conditional discriminations shown here imply
that further analyses with young children will be particularly important in
efforts to investigate the development of theoretically important stimulus
relations.
PMID- 10784009
TI - The spatial distribution of behavior under varying frequencies of temporally
scheduled water delivery.
AB - Two studies evaluated the effects of response-independent water deliveries on the
location (on the floor of the experimental chamber) and position (height) of
rats' behavior. In both experiments, fixed-time schedules delivered water in two
dispensers that were located at opposite ends of the chamber. In Experiment 1,
the two schedules provided complementary frequencies of water deliveries while
the overall number of deliveries stayed constant. In Experiment 2, one of the
schedules delivered water twice as frequently as the other; this proportion was
kept constant while the overall density of water deliveries changed
systematically. In both experiments, a single position (height) of behavior was
dominant. Also, the percentage of time allocated to each dispenser was roughly
proportional to the percentage of water deliveries associated with the
dispensers. These data and additional considerations support the importance of
examining the spatial properties and patterning of behavior.
PMID- 10784010
TI - Effects of compounding drug-related stimuli: escalation of heroin self
administration.
AB - Previous experiments have demonstrated that presenting independently established
discriminative stimuli in compound can substantially increase operant responding
maintained by food reinforcement or shock avoidance. Recently, this phenomenon
was also shown to occur with cocaine self-administration. The present study
further assessed the generality of these stimulus-compounding effects by
systematically replicating them with heroin self-administration. Rats' nose-poke
responses produced intravenous heroin (0.025 mg/kg per infusion) on a variable
ratio schedule when either a tone or a light was present. In the absence of these
stimuli, responding was not reinforced. Once discriminative control by the tone
and light had been established, the stimuli were presented in compound under
extinction (with heroin discontinued) or maintenance conditions (with heroin
available during test-stimulus presentations). In extinction, the tone-light
compound increased responding approximately threefold compared to tone or light
alone. Under maintenance conditions, compounding increased heroin intake
approximately twofold. These effects closely matched those obtained earlier with
cocaine. This consistency across pharmacological classes and across drug and
nondrug reinforcers further confirms that (a) self-administered drugs support
conditioning and learning in a manner similar to that supported by other
reinforcers; and (b) multiple drug-related cues interact in lawful and
predictable ways to affect drug seeking and consumption.
PMID- 10784011
TI - Varying wheel-running reinforcer duration within a session: effect on the
revolution-postreinforcement pause relation.
AB - Previous investigations of wheel-running reinforcement that manipulated
reinforcer duration across conditions showed a strong relation between wheel
running rate and average postreinforcement pause (PRP) duration. To determine if
the basis of this relation across conditions was a local effect of fatigue or
satiation, the correlation between revolutions run and the duration of the
immediately following PRP was investigated under conditions in which reinforcer
duration was either constant or variable within a session. Seven male Wistar rats
pressed a lever on a fixed-interval 60-s reinforcement schedule with the
opportunity to run for 60 s as the reinforcing consequence. In the constant
duration condition, the duration of the reinforcer was always 60 s. In the
variable-duration condition, the duration of the reinforcer varied between 2 and
240 s with a mean of 60 s. Mean correlations between revolutions run and the next
PRP duration for constant, variable, and constant conditions were -.07, .20, and
.07, respectively. Although the positive correlation in the variable-duration
condition is consistent with an effect of momentary fatigue or satiation, little
of the variance in PRP duration appears to be attributable to these factors.
PMID- 10784012
TI - Do not leave the operating room without it.
PMID- 10784013
TI - Hepatitis C virus infection: review and implications for the orthopedic surgeon.
AB - Hepatitis C virus (HCV), a single-stranded ribonucleic acid virus identified in
1989, is estimated to have infected 1%-2% of the United States population. The
incidence of HCV in patients requiring orthopedic surgery may be as high as 5%.
Surgeons and operating room personnel are at risk for blood-borne diseases
transmitted during surgery. The orthopedic surgeon must be aware of viral
infection with this pathogen for the safety of the entire operating room team.
Further, screening for HCV is routinely done when a patient donates autologous
blood prior to elective surgery, and the orthopedic surgeon is often the first or
only physician informed of a positive result. The surgeon should know how to
interpret the result, advise the patient, and incorporate the diagnosis of HCV
into the plan for the proposed surgery. We will review the natural history,
transmission, evaluation of, and current treatment for infection with this blood
borne virus.
PMID- 10784014
TI - Deep vein thrombosis prophylaxis: a comprehensive approach for total hip and
total knee arthroplasty patient populations.
AB - One of the most catastrophic complications after total joint arthroplasty is a
fatal pulmonary embolism. Thromboembolic disease is particularly a problem in
lower extremity joint arthroplasty secondary to the development of deep vein
thrombosis (DVT) and proximal propagation of the thrombus. The environment
created during total hip and knee arthroplasty fulfills the criteria for DVT
formation: vessel wall damage, venous stasis, and a hypercoagulable state.
Evidence that suggests the insult and primary event in thrombogenesis occurs
during surgery. Until recently, however, the main thrust of DVT prophylaxis has
concentrated on the immediate postoperative period. A more global approach to
patient care during the 6-week period beginning with surgery may result in more
effective DVT prophylaxis. Operative interventions that have proven to be
effective include hypotensive epidural anesthesia and intravenous administration
of heparin. Postoperative pharmaceutical interventions range from standard doses
of aspirin or warfarin to recently studied dosing regimens of low-molecular
weight heparins, antiplatelet agents, and antithrombotic agents. Mechanical
prophylaxis has also proved to be a valuable adjunct in DVT prophylaxis during
these periods. It is hoped that a more comprehensive approach incorporating
several of the aforementioned treatments into a strategy that encompasses the
intraoperative and early and late postoperative periods will maximize the
effectiveness of DVT prophylaxis.
PMID- 10784015
TI - Hepatitis C virus infection: knowledge in the orthopedic community.
AB - A survey with 14 questions pertaining to the natural history, infectiveness, and
diagnosis and treatment of hepatitis C viral infection was given to all
practicing orthopedic surgeons in Portland, Maine. Possible responses were
"true," "false," or "don't know" to the 14 statements. A question regarding any
interest in learning more about the hepatitis C virus was also posed. Most (82%,
23/28) surgeons completed the questionnaire. A total of 72% of the responses were
either wrong or marked "don't know"; most (83%) of the respondents wanted to know
more about the infection about hepatitis C viral infection. Not only are
orthopedic surgeons at risk for exposure to this virus, but also they are often
the first to notify a patient of a positive result after routine hepatitis C
testing of autologous predonated blood. Education programs and journal reviews
should be directed toward this goal.
PMID- 10784016
TI - Use of the entire width of the flexor carpi radialis tendon for the ligament
reconstruction tendon interposition arthroplasty does not impair wrist function.
AB - Although the original technical description of the ligament reconstruction tendon
interposition arthroplasty as treatment for osteoarthritis at the base of the
thumb included use of one half of the width of the flexor carpi radialis (FCR)
tendon, it has been recommended that the entire width be used to simplify harvest
and provide a larger piece of tissue for ligament reconstruction. The objective
of this study was to evaluate preoperative and postoperative wrist motion and
flexion strength, subjectively and objectively, to identify whether the use of
the entire width of the FCR tendon results in decline or weakness. Our findings
show neither subjective nor objective impairment of wrist motion or flexion
strength at 1-year follow-up; 6 months after the procedure, strength had returned
nearly to baseline.
PMID- 10784017
TI - Quantitative anatomy of the scapula.
AB - Thirty adult bony scapulae were used to report detailed bony dimensions of the
scapula. The measurements of bony dimensions of the scapula included the glenoid,
coracoid, spine, and body. The results of the measurements showed that the
thickest bony stock (posteroanterior diameter), with a mean value of 13 mm to 23
mm in the glenoid process, was found in the middle third of the area within 1 cm
medial to the glenoid rim. In the scapular spine region, the greatest
superoinferior diameter of the bone was noted in the lateral portion of the
spine, followed by the medial portion. It was also found that smallest
superoinferior diameter (2 mm to 7 mm) of the spine was located at the middle
portion between the base and ridge along the whole spine. On the lateral border
of the scapula, the posteroanterior diameter of bone was relatively greater for
the upper portion (8 mm) than for the lower portion, including the inferior angle
(6 mm). This information may be helpful in open reduction and internal fixation
of significantly displaced scapular fractures.
PMID- 10784018
TI - A case of recurrent trigger thumb.
AB - In this report we present a case of recurrent trigger thumb after surgical
release. A 3-year-old girl underwent surgical release of the first annular pulley
at another institution. The resected first annular pulley had been confirmed by
pathologic analysis. After surgery the triggering and locking recurred, and she
developed limited function due to persistent pain. The second operative release
revealed a fibrous band in the region of the previous first annular pulley and a
thickened flexor tendon sheath.
PMID- 10784019
TI - A bench-top method for evaluating modular total hip component combinations.
AB - A modular total hip prosthesis allows the surgeon to vary head size, neck length,
and acetabular coverage. Different combinations, however, may increase the risk
of impingement of the prosthesis neck on the acetabular liner, leading to
dislocation. We developed a bench-top model to test different modular component
combinations to determine how far the femoral component could travel within the
acetabular liner before impingement led to dislocation. We tested two hip
systems, each from a different manufacturer. Certain components increased the
risk of impingement and dislocation: skirted necks, smaller heads, and lipped
liners. While the contribution of each component was small, the risk was
additive, so that the combination of a small head with a skirted neck in a lipped
liner actually reduced the available range of motion by 18 degrees, from 146
degrees to 128 degrees, in the first system, and by 13 degrees, from 156 degrees
to 143 degrees in the other. This method could be adapted to test a wide range of
component configurations, from a number of manufacturers. These findings may be
useful in avoiding potentially unstable configurations when given a choice of
modular components.
PMID- 10784020
TI - Coma from fat embolism syndrome after hemiarthroplasty of the hip for metastatic
breast cancer to the proximal femur: a case report.
AB - We present a case report of fat embolism syndrome (FES) that resulted in
prolonged coma after cemented hemiarthroplasty in a patient with metastatic
breast cancer. After the cemented hip prosthesis was placed, the patient
developed decreased sensorium that progressed to coma in association with
hypoxemia and tachypnea. Pulmonary compromise was mild, and the patient required
only supplemental oxygen for support. The patient demonstrated no petechiae.
Magnetic imaging results were consistent with FES. While the pulmonary symptoms
resolved quickly, the patient remained unresponsive for 11 days without
purposeful motor function. After waking she recovered rapidly, and at her 2-month
follow-up appointment, demonstrated no adverse orthopedic, pulmonary, or
neurologic sequelae.
PMID- 10784021
TI - Massive subperiosteal hemorrhage and femoral shaft osteonecrosis: a complication
of tissue plasminogen activator therapy for purpura fulminans.
AB - We present the case of a child who developed a massive subperiosteal hemorrhage
and subsequent osteonecrosis of her right femur after treatment with tissue
plasminogen activator for post-varicella streptococcal purpura fulminans.
Radiographs showed posteromedial translation of the capital femoral epiphysis on
the necrotic shaft, and the hip was immobilized. The femur slowly remodeled and
has continued to grow. The child is independently ambulatory with a 2.1-cm leg
length discrepancy, a varus deformity of the hip, and a valgus distal femur.
PMID- 10784022
TI - Soft tissue hemangioma.
PMID- 10784023
TI - Delayed brachial plexus neurapraxia complicating malunion of the clavicle.
AB - Delayed brachial plexus neurapraxia is a rare complication of midshaft clavicular
fracture. The symptoms are variable and occur insidiously. Surgical decompression
to release the compression of brachial plexus is the treatment of choice and
usually has a good result. We report a patient whose brachial plexus was
compressed by malunion of the clavicle. This patient had a good outcome after
treatment with intramedullary nailing and Knowles pin fixation after corrective
osteotomy without bone grafting.
PMID- 10784024
TI - Extraction of a supracondylar nail through the proximal femur during total hip
arthroplasty.
AB - With the increasing popularity of supracondylar femoral intramedullary nails,
removal of these devices may become necessary during total hip arthroplasty. The
present article describes a technique for extracting these nails in a retrograde
fashion through the proximal femur, thus sparing the patient a knee arthrotomy.
PMID- 10784025
TI - Deamidation of a model hexapeptide in poly(vinyl alcohol) hydrogels and xerogels.
AB - Polymeric controlled release systems have been proposed to prolong the half-lives
of protein and peptide drugs in vivo and to deliver active drug at a controlled
rate. These systems are ineffective, however, if the drug is not stable during
storage and release. This study addresses the effect of poly(vinyl alcohol) on
the stability and release of an incorporated hexapeptide, VYPNGA, which undergoes
deamidation. Two types of peptide-loaded poly(vinyl alcohol) matrices were
formed, a semisolid hydrogel and a lower water content 'xerogel', and stored at
50 degrees C for up to 122 days. The hexapeptide was less stable in both
poly(vinyl alcohol) matrices than in aqueous buffer or lyophilized polymer-free
powders. The type of poly(vinyl alcohol) matrix appeared to influence the
degradation mechanism, since the product distributions differ in the hydrogel and
the xerogel. The results suggest that, rather than stabilizing this peptide,
incorporation in poly(vinyl alcohol) matrices reduces stability relative to
solution and lyophilized controls.
PMID- 10784026
TI - Bioactive fMLF-OMe analogs containing a N-terminal oximic or formylhydrazonic
moiety.
AB - In order to obtain chemotactic peptides with selective bioactivity, a new type of
structural modification was introduced at the N-terminal position of HCO-Nle-Leu
Phe-OMe. Two groups of analogs have been synthesized both containing a N-terminal
residue of the X=C(R)-CO-type replacing the native HCO-NH-CH(R)-CO-. In
particular, the A group of pseudopeptides (2a-d) possesses a N-terminal oximic
fragment (X=HO-N) and the B group (3a-d) a formylhydrazone fragment (X=HCO-NH-N).
These new ligands have been examined for their capacity to induce chemotaxis and
other cellular responses such as superoxide anion production and lysozyme
release; although significantly active as chemoattractants they have been found
to be practically devoid of secretagog activity, thus exhibiting selective
behavior. The adopted chemical modification seems extensible in designing a new
class of pseudopeptides (hydrazonopeptides) structurally related to both
hydrazinopeptides and peptides containing alpha,beta-unsaturated residues.
PMID- 10784027
TI - (1H-benzotriazol-1-yloxy)-N,N-dimethylmethaniminium hexachloroantimonate (BOMI),
a novel coupling reagent for solution and solid-phase peptide synthesis.
AB - A HOBt-based immonium-type compound,(1H-benzotriazol-1-yloxy)-N,N-dimethyl
methaniminium hexachloroantimonate (BOMI), was synthesized and successfully
applied to the synthesis of various oligopeptides with good yields. The
estimation of racemization and the influence of several reaction parameters such
as solvents, bases and temperature were studied by HPLC using a model reaction.
It was found that the reactivity of BOMI was much higher than that of HOBt-based
phosphonium- and uronium-type coupling reagents. Moreover, its racemization was
lower than that of other HOBt-derived coupling reagents. The effectiveness of
BOMI was also demonstrated by the synthesis of Leu-enkephalin both in solution
and in the solid-phase.
PMID- 10784028
TI - 1H-NMR determination of the solution structure and absolute configuration of
FR134043, a novel inhibitor of human leukocyte elastase.
AB - FR134043 is a semisynthetic disulfonated derivative of the natural product
FR901277, is isolated from the culture filtrate of Streptomyces resistomicificus
and has potent inhibitory activity against human leukocyte elastase. Although the
chemical structure of FR134043 was determined to be a unique bicyclic peptide
like compound consisting of seven amino acids by using several spectroscopic
analytical methods, the chiralities of three centers were unknown. A simple
simulated annealing protocol to determine the structure was applied to the eight
possible stereoisomers, and the one that best satisfied the NOE distance
constraints was determined to be the true stereoconfiguration of FR134043. The
solution structure showed that all Calpha atoms existed in the L configuration
and six of the seven side chains were located towards the outside of the bicyclic
framework, even though most of them are highly hydrophobic moieties. The
simulated annealing calculation described here is a frequently used method for
the determination of the solution structure of peptides or small proteins. We
show here that it is also applicable to the determination of the absolute
configuration of macrocyclic compounds produced from natural sources.
PMID- 10784029
TI - Solution stability of salmon calcitonin at high concentration for delivery in an
implantable system.
AB - Salmon calcitonin solutions (50 mg/mL and 100 mg/mL) were placed on stability at
37 degrees C for 1 year in a variety of solvent systems including water, ethanol,
glycerol, propylene glycol (PG) and dimethyl sulfoxide (DMSO). Calcitonin
degradation was monitored by RP-HPLC and size-exclusion chromatography. DMSO and
pH 3.3 solutions provided optimum stability. Conformational stability was also
monitored by FTIR over the 1 year time course and compared with chemical and
physical stability. After 12 months at 37 degrees C, four major conformations
were observed: a beta-sheet conformation (pH 3.3, pH 5.0, 70% DMSO and 70%
glycerol), an aggregate conformation (pH 7.0 water), a strong alpha-helical
conformation (70% EtOH, 70% PG) and a weak alpha-helical conformation (100%
DMSO). No correlation between structure and chemical stability was observed in
which both the beta-sheet structure (pH 3.3, water) and a loose alpha-helical
structure (100% DMSO) demonstrated good stability. However, some correlation was
observed between structure and physical stability, where co-solvents inducing an
alpha-helical structure resulted in a decrease in gelation. These two structural
states associated with improved stability and minimal gelation, indicated that
gelation can be reduced or eliminated by the use of pharmaceutically acceptable
co-solvents. Finally, salmon calcitonin (50 mg/mL) was formulated in 100% DMSO
and delivered from a DUROS implant over 4 months. Delivery at a target dose of 18
microg/day calcitonin at 37 degrees C was confirmed.
PMID- 10784030
TI - Alkylation of cysteine-containing peptides to mimic palmitoylation.
AB - Numerous proteins that are involved in cell signaling and viral replication
require post-translational modification by palmitoylation to function properly.
The molecular details by which this palmitoyl modification affects protein
function remain poorly understood. To facilitate in vitro biochemical and
structural studies of the role of palmitoylation on protein function, a method
was developed for alkylating peptides with saturated C16 groups at cysteine
residues and demonstrated using peptides derived from the palmitoylated region of
Sindbis virus E2 glycoprotein. The synthetic approach takes advantage of
disulfide chemistry to specifically modify only the cysteine residues within
peptides and covalently links C16 groups via disulfide bridges using a new
thioalkylating reagent, hexyldexyldithiopyridine. The chemistry presented here
takes place in solution under mild conditions without the need for protection of
the peptide functional groups. A method for purifying these modified peptides is
also described. This protocol can be of general use to investigators studying the
role of palmitoylation in biological systems.
PMID- 10784032
TI - Structure-activity relationship of truncated and substituted analogues of the
intracellular delivery vector Penetratin.
AB - Peptides derived from the third alpha-helix of the homeodomain (residues 43-58;
Penetratin) of Antennapedia, a Drosophila homeoprotein, were prepared by
simultaneous multiple synthesis. Sets of N- and C-terminally truncated peptides,
as well as a series of alanine substitution analogues, were studied. Cell
penetration assays using human cell cultures with these peptides revealed that
the C-terminal segment 52Arg-Arg-Met-Lys-Trp-Lys-Lys58 of the parent sequence was
necessary and sufficient for efficient cell membrane translocation. Individual
Ala substitutions of the peptide's basic residues led to markedly decreased cell
internalization ability, whereas replacement of hydrophobic residues was
tolerated surprisingly well. Subcellular localization was seen to be affected by
substitutions, with analogues being addressed preferentially to the cytosol or to
the nucleus. Conformational constriction of the Penetratin sequence through
placement and oxidation of flanking cysteine residues afforded a cyclic disulfide
peptide which had lost most of its membrane translocation capacity.
PMID- 10784031
TI - Novel, potent calmodulin antagonists derived from an all-D hexapeptide
combinatorial library that inhibit in vivo cell proliferation: activity and
structural characterization.
AB - Calmodulin is known to bind to various amphipathic helical peptide sequences, and
the calmodulin-peptide binding surface has been shown to be remarkably tolerant
sterically. D-Amino acid peptides, therefore, represent potential nonhydrolysable
intracellular antagonists of calmodulin. In the present study, synthetic
combinatorial libraries have been used to develop novel D-amino acid hexapeptide
antagonists to calmodulin-regulated phosphodiesterase activity. Five hexapeptides
were identified from a library containing over 52 million sequences. These
peptides inhibited cell proliferation both in cell culture using normal rat
kidney cells and by injection via the femoral vein following partial hepatectomy
of rat liver cells. These hexapeptides showed no toxic effect on the cells.
Despite their short length, the identified hexapeptides appear to adopt a partial
helical conformation similar to other known calmodulin-binding peptides, as shown
by CD spectroscopy in the presence of calmodulin and NMR spectroscopy in DMSO.
The present peptides are the shortest peptide calmodulin antagonists reported to
date showing potential in vivo activity.
PMID- 10784033
TI - Short synthetic glycopeptides successfully induce antibody responses to carcinoma
associated Tn antigen.
AB - Glycopeptides containing a tumor-associated carbohydrate antigen (mono-, tri- or
hexa-Tn antigen) as a B-cell epitope and a CD4+ T-cell epitope (PV: poliovirus or
TT: tetanus toxin) were prepared for immunological studies. Several Tn antigen
residues [FmocSer/Thr (alpha-GalNAc)-OH] were successively incorporated into the
peptide sequence with unprotected carbohydrate groups. The tri- and hexa-Tn
glycopeptides were recognized by MLS128, a Tn-specific monoclonal antibody. The
position of the tri-Tn motif in the peptide sequence and the peptide backbone
itself do not alter its antigenicity. As demonstrated by both ELISA and FACS
analysis, the glycopeptides induced high titers of anti-Tn antibodies in mice, in
the absence of a carrier molecule. In addition, the generated antibodies
recognized the native Tn antigen on cancer cells. The antibody response obtained
with a D-(Tn3)-PV glycopeptide containing three alpha-GalNAc-D-serine residues is
similar that obtained with the Tn6-PV glycopeptide. These results demonstrate
that short synthetic glycopeptides are able to induce anticancer antibody
responses.
PMID- 10784034
TI - Surface-active proteins enable microbial aerial hyphae to grow into the air.
PMID- 10784035
TI - Nicotinoprotein (NADH-containing) alcohol dehydrogenase from Rhodococcus
erythropolis DSM 1069: an efficient catalyst for coenzyme-independent oxidation
of a broad spectrum of alcohols and the interconversion of alcohols and
aldehydes.
AB - Extracts from benzyl-alcohol-grown Rhodococcus erythropolis DSM 1069 showed
NAD(P)-independent, N,N-dimethyl-4-nitrosoaniline (NDMA)-dependent alcohol
dehydrogenase activity. The enzyme exhibiting this activity was purified to
homogeneity and characterized. It appears to be a typical nicotinoprotein as it
contains tightly bound NADH acting as cofactor instead of coenzyme. Other
characteristics indicate that it is highly similar to the known nicotinoprotein
alcohol dehydrogenase (np-ADH) from Amycolatopsis methanolica: it is a
homotetramer of 150 kDa; N-terminal amino acid sequencing (22 residues) showed
that 77% of these amino acids are identical in the two enzymes; it has optimal
activity at pH 7.0; it lacks NAD(P)H-dependent aldehyde reductase activity; it
catalyses the oxidation of a broad range of (preferably) primary and secondary
alcohols, either aliphatic or aromatic, and formaldehyde, with the concomitant
reduction of the artificial electron acceptor NDMA. NDMA could be replaced by an
aldehyde, but not formaldehyde, the substrate specificity of the enzyme for the
aldehydes reflecting that for the corresponding alcohols. The latter also applied
to the low aldehyde dismutase activity displayed by the enzyme. From this,
together with the results of the induction studies, it is concluded that np-ADH
functions as the main alcohol-oxidizing enzyme in the dissimilation of many, but
not all, alcohols by R. erythropolis and may also catalyse coenzyme-independent
interconversion of alcohols and aldehydes under certain circumstances. It is
anticipated that the enzyme may be of even wider significance since structural
data indicate that np-ADH is also present in other (nocardioform) actinomycetes.
PMID- 10784036
TI - Ubiquinone limits oxidative stress in Escherichia coli.
AB - Ubiquinone is an essential redox component of the aerobic respiratory chains of
bacteria and mitochondria. It is well established that mammalian ubiquinone can
function in its reduced form (ubiquinol) as a lipid-soluble antioxidant
preventing lipid peroxidation. The objective of this study was to test the
hypothesis that prokaryotic ubiquinone is involved in the defence against
oxidative stress in the cytoplasmic membrane. The rate of superoxide production
by rapidly respiring wild-type Escherichia coli membranes was twofold higher than
in the slowly respiring membranes from a ubiCA knockout mutant. However, large
amounts of superoxide accumulated in the Ubi- membranes compared to wild-type
membranes, which possess superoxide-scavenging ubiquinol. Likewise, the rate of
H2O2 production was twofold higher in the wild-type, but the overall production
of H2O2 was again significantly higher in the Ubi- membranes. Inclusion of a
water-soluble ubiquinone homologue (UQ-1) effectively decreased the amount of
H2O2 produced in the Ubi- membranes in a concentration-dependent manner. Addition
of UQ-2 to the membranes was even more effective in limiting accumulation of H2O2
than was UQ-1, suggesting a role for the side-chain in conferring liposolubility
in the antioxidative defence mechanism. Intracellular H2O2 concentration was
increased 1.8-fold in the ubiCA mutant, and expression of the katG gene, encoding
the catalase hydroperoxidase I, as well as catalase enzyme activity, were
increased twofold in this mutant. The ubiCA mutant was hypersensitive to
oxidative stress mediated by CuSO4 or H2O2; sensitivity to the latter could be
abolished by addition of cysteine. This phenotype was also exhibited by a ubiG
mutant, defective in the last step of UQ biosynthesis and therefore expected to
accumulate several UQ biosynthetic intermediates. These observations support the
participation of reduced ubiquinone as an antioxidant in E. coli. The ubiCA
mutant exhibited a pleiotropic phenotype, being resistant to heat, linolenic acid
and phleomycin. Resistance to the two latter compounds is probably due to reduced
uptake. Like mutants unable to synthesize the quinol oxidase, cytochrome bd, the
ubiCA mutant was also sensitive to dithiothreitol, an effect that is attributed
to inability of the respiratory chain to maintain an appropriate redox balance in
the periplasm.
PMID- 10784037
TI - Incorporation of [2-3H]glycerol into cell surface components of Bacillus subtilis
168 and thermosensitive mutants affected in wall teichoic acid synthesis: effect
of tunicamycin.
AB - A method is described for measuring the synthesis of poly(glycerol phosphate)
[poly(groP)], the major wall teichoic acid (WTA), lipoteichoic acid (LTA) and
phospholipid (P-lipid), through fractionation of [2-3H]glycerol ([2-3H]gro)
labelled Bacillus subtilis cells. When cultures of certain temperature-sensitive
mutants defective in one of several tag genes, encoding enzymes involved in WTA
synthesis, were transferred to the restrictive temperature, the synthesis of WTA
underwent a specific, immediate, block, while that of LTA or P-lipid proceeded
unimpeded. These results, in addition to confirming the role of tag genes,
demonstrated, reciprocally, the specificity of the fractionation procedure used
to distinguish label in WTA from that in LTA or P-lipid. Results of analysis of
other, less severely affected, tag-deficient mutants, as well as of another
genetically unrelated mutant developing comparable morphological phenotypes in
non-permissive conditions, are discussed in relation to a possible mechanism
generating the latter phenotype. Fractionation of B. subtilis 168 cells labelled
either with [2-3H]gro or with [1-14C]N-acetylglucosamine, to which tunicamycin
was added at 0.5 microg ml(-1) (the MIC) revealed a specific and marked
inhibition of poly(groP) as well as of poly(3-O-beta-D-glucopyranosyl-N
acetylgalactosamine 1-phosphate), the minor WTA. However, for 60 min at least,
the syntheses of PG, LTA and P-lipid were barely affected.
PMID- 10784038
TI - The yexA gene product is required for phosphoribosylformylglycinamidine
synthetase activity in Bacillus subtilis.
AB - The yexA gene encodes an 84 amino acid reading frame; in Bacillus subtilis it is
positioned between the purC and purQ genes of the purine biosynthetic operon.
Disruption of yexA resulted in a purine-auxotrophic phenotype. When yexA was
expressed in trans it was able to complement a yexA mutation. Growth experiments
and enzyme analysis of yexA mutant strains revealed a defective
phosphoribosylformylglycinamidine synthetase (FGAM synthetase). In the organisms
in which FGAM synthetase has been studied a single polypeptide is responsible for
activity. In some organisms two separate genes - in B. subtilis the purL and purQ
genes - encode polypeptides with similarity to the N-terminal and the C-terminal
region, respectively, of the single-polypeptide FGAM synthetase. Thus, active
FGAM synthetase in B. subtilis requires the yexA gene product in addition to the
purL and purQ gene products. Open reading frames with sequence similarity to yexA
are found in other Gram-positive organisms, in a cyanobacterium and in
methanogenic archaea. The designation purS is proposed for this novel function in
purine biosynthesis in B. subtilis.
PMID- 10784039
TI - The Bacillus subtilis cysP gene encodes a novel sulphate permease related to the
inorganic phosphate transporter (Pit) family.
AB - Sulphate permeases in the plasma membrane are responsible for uptake of
environmental sulphate used in the sulphate assimilation pathway in bacteria and
plants. Here it is reported that the ORF designated cysP, located on the Bacillus
subtilis chromosome between cysH and five putative genes involved in sulphate
assimilation, encodes a sulphate permease. cysP is able to complement Escherichia
coli cysteine auxotrophs with mutations affecting either the membrane or
periplasmic components of the sulphate-thiosulphate permease. Transport studies
with cell suspensions of a cysA97 E. coli strain transformed with a plasmid
expressing the B. subtilis cysP gene indicated that CysP catalyses sulphate
uptake. Analysis of the primary sequence showed that CysP (354 amino acids,
estimated molecular mass 24 kDa) is a highly hydrophobic protein which has 11
putative transmembrane helices. Sequence comparisons revealed that CysP, together
with the phosphate permease of Neurospora crassa, Pho-4, and E. coli PitA,
belongs to the family of related transporters, the inorganic phosphate
transporter (Pit) family. Among the putative phosphate permeases, CysP shows a
similar size and the same domain organization as the archaeal transporters. This
is the first report of a sulphate permease in a Gram-positive organism.
PMID- 10784040
TI - RT-PCR as a tool for systematic transcriptional analysis of large regions of the
Bacillus subtilis genome.
AB - Transcriptional analysis of five different regions of the Bacillus subtilis 168
genome, comprising a total of 175 kb encoding newly identified genes, was carried
out using the RT-PCR technique as part of the functional analysis of the whole
genome of this bacterium. Amplification of mRNA fragments allowed the detection
of both highly and poorly transcribed genes covering 81% of putative ORFs, and
also the monitoring of variations in the expression level among genes
differentially expressed during particular bacterial growth phases.
PMID- 10784041
TI - Analysis of the Rhizobium leguminosarum siderophore-uptake gene fhuA:
differential expression in free-living bacteria and nitrogen-fixing bacteroids
and distribution of an fhuA pseudogene in different strains.
AB - A mutation was isolated in the Rhizobium leguminosarum gene fhuA, which appears
to specify the outer-membrane receptor for the siderophore vicibactin. The mutant
was defective in iron uptake and accumulated the siderophore vicibactin in the
extracellular medium. Expression of fhuA was regulated by Fe3+, transcription
being higher in iron-depleted cells. Transcription of fhuA was independent of a
functional copy of rpol, a neighbouring gene that specifies a putative ECF sigma
factor of RNA polymerase and which is involved in siderophore production in
Rhizobium. Mutations in fhuA did not detectably affect symbiotic N2 fixation on
peas. An fhuA::gus fusion was expressed by bacteria in the meristematic zone of
pea nodules but not in mature bacteroids. Some other strains of R. leguminosarum
also contain a pseudogene version of fhuA. The sequences of some of these and the
'real' fhuA genes were determined.
PMID- 10784042
TI - Expression and purification of four different rhizobial acyl carrier proteins.
AB - In rhizobia, besides the constitutive acyl carrier protein (AcpP) involved in the
biosynthesis and transfer of common fatty acids, there are at least three
specialized acyl carrier proteins (ACPs): (1) the flavonoid-inducible nodulation
protein NodF; (2) the RkpF protein, which is required for the biosynthesis of
rhizobial capsular polysaccharides; and (3) AcpXL, which transfers 27
hydroxyoctacosanoic acid to a sugar backbone during lipid A biosynthesis. Whereas
the nucleotide sequences encoding the three specialized ACPs are known, only the
amino acid sequence of the AcpP of Sinorhizobium meliloti was available. In this
study, using reverse genetics, the genes for the constitutive AcpPs of S.
meliloti and of Rhizobium leguminosarum were cloned and sequenced. Previously, it
had been shown that NodF and RkpF can be overproduced in Escherichia coli using
the T7 polymerase expression system. Using the same system, the constitutive
AcpPs of S. meliloti and of R. leguminosarum, together with the specialized ACP
AcpXL, were overproduced and purified. All the known ACPs of rhizobia can be
labelled in vivo during expression in E. coli with radioactive beta-alanine added
to the growth medium due to their modification with a 4'-phosphopantetheine
prosthetic group. The availability of all functionally different ACPs should help
to unravel how different fatty acids are targeted towards different biosynthetic
pathways in one organism.
PMID- 10784043
TI - Absence of translationally selected synonymous codon usage bias in Helicobacter
pylori.
AB - Synonymous codon usage in the complete genome of Helicobacter pylori was
investigated. The moderate A+T-richness of the genome (G+C=39 mol%) is reflected
in the overall synonymous codon usage but the frequencies of some codons cannot
be explained by simple mutational biases. A low level of heterogeneity among
genes was observed, but this does not appear to be due to varying mutational bias
or translational selection. Some of the heterogeneity was due to amino acid
composition variation among the encoded proteins, and some may be attributable to
recent acquisition of genes from other species. Since Hel. pylori codon usage is
not dominated by biased mutation patterns, the absence of evidence for
translationally mediated selection among synonymous codons is striking. This has
implications with regard to the life history of this species, and in particular
suggests that Hel. pylori strains are not subject to periods of competitive
exponential growth. Despite the lack of selected codon usage, base composition
immediately after the translation initiation site is skewed, consistent with
selection against secondary structure formation in this region.
PMID- 10784045
TI - Candida albicans CFL1 encodes a functional ferric reductase activity that can
rescue a Saccharomyces cerevisiae fre1 mutant.
AB - Candida albicans, like other pathogens, has to compete with the host for a
limited supply of available iron. Consequently, iron acquisition is likely to be
an important factor for the growth, survival and virulence of this organism. It
was previously demonstrated that C. albicans has a surface-associated ferric
reductase similar to that of Saccharomyces cerevisiae. Therefore, functional
rescue of a S. cerevisiae fre1 mutant was used to isolate a C. albicans ferric
reductase gene (CFL1). This gene has been previously identified. However, the
workers had not observed any functional reductase activity associated with the
gene. The discrepancy with the findings in this report appears to be due to the
clone previously reported carrying a non-contiguous piece of C. albicans DNA.
Results shown in this paper demonstrate that CFL1 transcription is regulated in
response to levels of iron and copper. This is the first demonstration of a
functional ferric reductase gene from C. albicans.
PMID- 10784044
TI - The alpha-amylase gene amyH of the moderate halophile Halomonas meridiana:
cloning and molecular characterization.
AB - Two types of Tn1732-induced mutants defective in extracellular amylase activity
were isolated from the moderate halophile Halomonas meridiana DSM 5425. Type I
mutants displayed amylase activity in the periplasm, and were unable to use any
of the carbon sources tested, including starch and its hydrolysis product
maltose. The type II mutant was affected in the gene responsible for the
synthesis of the extracellular alpha-amylase. This gene (amyH) was isolated by
functional complementation of mutant II and sequenced. The deduced protein (AmyH)
showed a high degree of homology to a proposed family of alpha-amylases
consisting of enzymes from Alteromonas (Pseudoalteromonas) haloplanktis,
Thermomonospora curvata, streptomycetes, insects and mammals. AmyH contained the
four highly conserved regions in amylases, as well as a high content of acidic
amino acids. The amyH gene was functional in the moderate halophile Halomonas
elongata and, when cloned in a multicopy vector, in Escherichia coli. AmyH is
believed to be the first extracellular-amylase-encoding gene isolated from a
moderate halophile, a group of extremophiles of great biotechnological potential.
In addition, H. meridiana and H. elongata were able to secrete the thermostable
alpha-amylase from Bacillus licheniformis, indicating that members of the genus
Halomonas are good candidates for use as cell factories to produce heterologous
extracellular enzymes.
PMID- 10784046
TI - Cellular lipid composition influences stress activation of the yeast general
stress response element (STRE).
AB - The heat inducibility of the yeast heat-shock response (HSR) pathway has been
shown to be critically dependent on the level of unsaturated fatty acids present
in the cell. Here the inducibility by heat or salt of the independently regulated
general stress response (GSR) pathway is shown to be affected in the same way. An
increase in the percentage of unsaturated fatty acids in heat- or salt-acclimated
cells correlated with a decrease in the induction of a general stress-response
promoter-element (STRE)-driven reporter gene by either stress. Despite inducing
reporter gene expression, sorbic acid treatment did not confer salt cross
tolerance on the cells. This failure correlated with a failure to increase the
percentage of unsaturated fatty acids in the cells, suggesting that GSR pathway
induction, in the absence of lipid changes, is insufficient for the induction of
cross-tolerance. Cells grown with fatty acid supplements under anaerobic
conditions provided further evidence for a potential role for lipids in the
acquisition of stress resistance. These cells contained different fatty acid
profiles depending on the fatty acid supplement supplied, exhibited differential
sensitivity to both heat and salt stress, but had not undergone STRE induction.
These results suggest that heat- and salt-stress induction of the GSR are
sensitive to the level of unsaturated fatty acids present in the cell and that
stress cross-tolerance may be a lipid-mediated phenomenon. Given that an
increased level of unsaturated fatty acids also down-regulates heat induction of
the HSR pathway, these observations lead to the provocative hypothesis that lipid
modifications, rather than HSR or GSR pathway induction, are a major contributor
to the induced heat and salt tolerance of yeast cells.
PMID- 10784047
TI - Novel genes involved in the regulation of pathogenicity factor production within
the rpf gene cluster of Xanthomonas campestris.
AB - The synthesis of extracellular enzymes and extracellular polysaccharide (EPS) in
Xanthomonas campestris pathovar campestris (Xcc) is subject to co-ordinate
regulation by a cluster of genes called rpf (for regulation of pathogenicity
factors). These genes are located within a 21.9 kb region of the chromosome
isolated as the cosmid clone pIJ3020. The genes in the left-hand section of this
region of the chromosome have previously been characterized. This paper reports
on the genes in the right-hand section and on the phenotypes of mutants with
transposon insertions in these genes. Sequence analysis identified eight genes or
ORFs with the gene order rpfD-orf1-orf2-orf3-orf4-recJ-rpf E-greA. RecJ and GreA
have established functions in recombination and transcriptional elongation,
respectively. rpfD encoded a protein with some amino acid sequence relatedness to
a hypothetical protein from Caulobacter crescentus and an autolysin response
regulator in Bacillus subtilis. The predicted protein products of orf1, 2 and 3
were related to each other and had substantial amino acid sequence relatedness to
hypothetical proteins from C. crescentus. Transposon insertions in orf1, 2 and 3
had no effect on the synthesis of extracellular enzymes or EPS. The predicted
proteins RpfE and Orf4 showed the highest amino acid sequence relatedness to
hypothetical proteins from Bordetella pertussis and Klebsiella pneumoniae,
respectively. Transposon insertions in rpfE led to reduced levels of some
extracellular enzymes (endoglucanase and protease) and increased levels of others
(polygalacturonate lyase). Transposon insertions in orf4 had no effect on
polygalacturonate lyase but led to reduced levels of protease and endoglucanase.
Levels of EPS were reduced in both rpfE and orf4 mutants. These alterations in
the levels of extracellular enzymes, which were relatively modest (between two-
and threefold), did not affect the pathogenicity of Xcc on turnip. It is proposed
that the gene designation should be rpfI for orf4.
PMID- 10784048
TI - Chromosome mapping of the sweet potato little leaf phytoplasma reveals genome
heterogeneity within the phytoplasmas.
AB - To further understand the genomic diversity and genetic architecture of
phytoplasmas, a physical and genetic map of the sweet potato little leaf (SPLL)
strain V4 phytoplasma chromosome was determined. PFGE was used to determine the
size of the SPLL-V4 genome, which was estimated to be 622 kb. A physical map was
prepared by two-dimensional reciprocal digestions using the restriction
endonucleases BssHII, Smal, Eagl and I-Ceul. Sixteen cleavage sites were located
on the map. Southern hybridizations of digested SPLL-V4 chromosomal DNA were done
using random clones and PCR-amplified genes as probes. This confirmed fragment
positions and located the two rRNA operons and the linked fus/tuf genes encoding
elongation factors G and Tu, respectively, on the physical map. An inversion of
one of the rRNA operons was observed from hybridization data. Sequence analysis
of one of the random clones identified a gid gene encoding a glucose-inhibited
division protein. Digestions of the tomato big bud (TBB) phytoplasma chromosome
with the same four enzymes revealed genome heterogeneity when compared to the
closely related SPLL-V4, and a preliminary chromosome size for the TBB
phytoplasma of 662 kb was estimated. This mapping information has revealed that
significant genome diversity exists within the phytoplasmas.
PMID- 10784049
TI - An acyl-coenzyme A carboxylase encoding gene associated with jadomycin
biosynthesis in Streptomyces venezuelae ISP5230.
AB - Analysis of a region of chromosomal DNA lying between jadR1 and jadI in the gene
cluster for jadomycin biosynthesis in Streptomyces venezuelae ISP5230 detected an
ORF encoding 584 amino acids similar in sequence to the biotin carboxylase (BC)
and biotin carboxyl carrier protein (BCCP) components of acyl-coenzyme A
carboxylases. Multiple sequence alignments of the deduced Jad protein with acyl
coenzyme A carboxylases from various sources located the BC and BCCP components
in the N- and C-terminal regions, respectively, of the deduced polypeptides. The
organization and amino acid sequence of the deduced polypeptide most closely
resembled those in other Gram-positive bacteria broadly classified as
actinomycetes. Disrupting the gene, designated jadJ, severely reduced but did not
eliminate jadomycin production. The disruption had no effect on growth or
morphology of the organism, implying that the product of jadJ is not essential
for fatty acid biosynthesis. It is concluded that jadJ supplies malonyl-coenzyme
A for biosynthesis of the polyketide intermediate that is eventually processed to
form the antibiotic jadomycin B.
PMID- 10784050
TI - The homologous terminal sequence of the Streptomyces lividans chromosome and SLP2
plasmid.
AB - The chromosome of Streptomyces lividans shares 15.4 kb homology with one end of
the linear plasmid SLP2, consisting of a 10.1 kb terminal sequence followed by
the 5.3 kb transposable element Tn4811. The 10.1 kb terminal sequence was
determined. The mean G+C content of this sequence is 67.9 mol% with a striking G
vs C bias in the last kb. The terminal 232 nt contained 10 palindromic sequences
with potential to form complex secondary structures. One typical Streptomyces
coding sequence (designated ORF1) of 2643 bp was predicted in the determined
sequence. The amino acid sequence of the ORF1 product contained a DEAH helicase
motif, and exhibited similarity to type I restriction enzyme HsdR subunits in the
database, suggesting a possible role in replication of the telomeres. However,
all the ORF1 sequences on the chromosome and SLP2 could be simultaneously knocked
out by targeted recombination without affecting the viability of the cells and
the linearity of the chromosome and SLP2. This ruled out ORF1 as an essential
component in the maintenance of the linear chromosome and plasmids.
PMID- 10784051
TI - The 1-kb-repeat-encoded DNA-binding protein as repressor of an alpha-glucosidase
operon flanking the amplifiable sequence AUD1 of Streptomyces lividans.
AB - High-copy-number amplification of the AUD1 element is frequently associated with
the large chromosomal deletions responsible for genetic instability in
Streptomyces lividans TK64. Five ORFs were found in a 7 kb region directly
adjacent to AUD1. The putative products of ORF1, ORF2 and ORF3 showed
similarities to ATP-binding cassette (ABC) sugar transporters, the deduced
protein sequence of ORF4 displayed similarities to alpha-glucosidases whilst no
homology to proteins with known functions was found for ORF5. ORF4 (renamed aglA)
was expressed in Escherichia coli and the protein purified and characterized. An
alpha-glucosidase activity was detected using the synthetic alpha-glucoside p
nitrophenyl alpha-D-glucopyranoside. Of the many oligosaccharides tested, only
sucrose was hydrolysed at a measurable rate [specific activity 32.4 units (mg
protein)(-1)] but no growth of S. lividans TK64 on sucrose was observed. A strain
in which aglA was disrupted showed the same low alpha-glucosidase activity as
strain TK64 and in both strains no stimulation of activity was seen by sucrose,
trehalose or maltose; dextrin increased alpha-glucosidase activity about 10-fold.
This probably resulted from induction of a second alpha-glucosidase-encoding
gene. The AUD1 element contains three 1 kb repeats which encode DNA-binding
proteins necessary for high-frequency amplification. In strains with a unique 1
kb repeat, disruption of the repeat led to a significant increase in the alpha
glucosidase activity. These results strongly suggest that the 1-kb-repeat-encoded
proteins of AUD1 have a dual function: they are the repressors of the agl genes
and they promote amplification of AUD1.
PMID- 10784052
TI - Six putative two-component regulatory systems isolated from Lactococcus lactis
subsp. cremoris MG1363.
AB - The genetic elements specifying six putative two-component regulatory systems
(2CSs) were identified on the chromosome of Lactococcus lactis MG1363. These 2CSs
appear to represent distinct loci, each containing a histidine kinase and
response-regulator-encoding gene pair. Transcriptional analysis of the six 2CSs
was performed either by generating transcriptional fusions to a reporter gene or
by primer extension. Two of the systems appeared to be expressed constitutively
at a high level, whilst the remaining four exhibited growth-phase-dependent
expression. Insertional mutagenesis established that the two constitutively
expressed 2CSs are necessary for normal cell growth and/or survival. Mutational
analysis of the remaining four systems revealed that they are implicated in
susceptibility to extreme pH, osmotic or oxidative conditions, or the regulation
of phosphatase activity in L. lactis.
PMID- 10784053
TI - Lactococcin 972, a bacteriocin that inhibits septum formation in lactococci.
AB - Addition of lactococcin 972 to exponentially growing sensitive cultures of
Lactococcus lactis resulted in cell elongation and widening. Thin sections
revealed that septum invagination was blocked. Cell growth progressed until most
cells showed equatorial constriction and even initial deposition of material at
the septum ring, although cell division did not proceed any further. The increase
in the incorporation of labelled precursors into the cell wall shifted from an
exponential to a linear mode in treated cultures, subsequently being arrested.
Gross degeneration of the cells was observed prior to cell death, followed by
slow lysis of the culture. In contrast, stationary-phase cultures remained
unaffected.
PMID- 10784054
TI - A Clostridium difficile gene encoding flagellin.
AB - Six strains of Clostridium difficile examined by electron microscopy were found
to carry flagella. The flagella of these strains were extracted and the N
terminal sequences of the flagellin proteins were determined. Four of the strains
carried the N-terminal sequence MRVNTNVSAL exhibiting up to 90% identity to
numerous flagellins. Using degenerate primers based on the N-terminal sequence
and the conserved C-terminal sequence of several flagellins, the gene encoding
the flagellum subunit (fliC) was isolated and sequenced from two virulent
strains. The two gene sequences exhibited 91% inter-strain identity. The gene
consists of 870 nt encoding a protein of 290 amino acids with an estimated
molecular mass of 31 kDa, while the extracted flagellin has an apparent molecular
mass of 39 kDa on SDS-PAGE. The FliC protein displays a high degree of identity
in the N- and C-terminal amino acids whereas the central region is variable. A
second ORF is present downstream of fliC displaying homology to
glycosyltransferases. The fliC gene was expressed in fusion with glutathione S
transferase, purified and a polyclonal monospecific antiserum was obtained.
Flagella of C. difficile do not play a role in adherence, since the antiserum
raised against the purified protein did not inhibit adherence to cultured cells.
PCR-RFLP analysis of amplified flagellin gene products and Southern analysis
revealed inter-strain heterogeneity; this could be useful for epidemiological and
phylogenetic studies of this organism.
PMID- 10784055
TI - Genetic characterization of pilin glycosylation in Neisseria meningitidis.
AB - Pili of Neisseria meningitidis are a key virulence factor, being the major
adhesin of this capsulate organism and contributing to specificity for the human
host. Pili are post-translationally modified by addition of an O-linked
trisaccharide, Gal(beta1-4)Gal(alpha1-3)2,4-diacetimido-2,4,6-trideoxyhexose++ +.
In a previous study the authors identified and characterized a gene, pglA,
encoding a galactosyltransferase involved in pilin glycosylation. In this study a
set of random genomic sequences from N. meningitidis strain MC58 was used to
search for further genes involved in pilin glycosylation. Initially, an open
reading frame was identified, and designated pglD (pilin glycosylation gene D),
which was homologous to genes involved in polysaccharide biosynthesis. The region
adjacent to this gene was cloned and nucleotide sequence analysis revealed two
further genes, pglB and pglC, which were also homologous with genes involved in
polysaccharide biosynthesis. Insertional mutations were constructed in pglB, pglC
and pglD in N. meningitidis C311#3, a strain with well-defined LPS and pilin
linked glycan structures, to determine whether these genes had a role in the
biosynthesis of either of these molecules. Analysis of these mutants revealed
that there was no alteration in the phenotype of LPS in any of the mutant strains
as judged by SDS-PAGE gel migration. In contrast, increased gel migration of the
pilin subunit molecules of pglB, pglC and pglD mutants by Western analysis was
observed. Pilin from each of the pglB, pglC and pglD mutants did not react with a
terminal-galactose-specific stain, confirming that the gel migration differences
were due to the alteration or absence of the pilin-linked trisaccharide structure
in these mutants. In addition, antisera specific for the C311#3 trisaccharide
failed to react with pilin from the pglB, pglC, pglD and galE mutants. Analysis
of nucleotide sequence homologies has suggested specific roles for pglB, pglC and
pglD in the biosynthesis of the 2,4-diacetimido-2,4,6-trideoxyhexose structure.
PMID- 10784056
TI - Identification of Staphylococcus aureus genes expressed during growth in milk: a
useful model for selection of genes important in bovine mastitis?
AB - Staphylococcus aureus is a major cause of bovine mastitis. Since gene expression
of many bacteria is known to be regulated by the environment, milk may play an
important role in the regulation of the early steps in the pathogenesis of bovine
mastitis by S. aureus. To get insight into the response of S. aureus to the milk
environment, a Tn917-lacZ mutant library was generated and screened for genes
specifically expressed during growth in milk. Twenty-eight mutants were
identified and analysed. Four groups of genes were found, involved in cell-wall
synthesis, nucleotide synthesis, transcriptional regulation and carbohydrate
metabolism. A fifth group contained genes with hypothetical or unknown functions.
Many of the genes identified belonged to biosynthetic pathways of S. aureus and
other bacterial species which have also been shown to play a role in vivo as
determined in murine infection models. Therefore, growth on milk may be an
attractive model for the identification of genes preferentially expressed during
bovine mastitis.
PMID- 10784057
TI - Biochemical characterization of different types of adherence of Vibrio species to
fish epithelial cells.
AB - Vibrio species are Gram-negative bacteria that cause a systemic infection in fish
called vibriosis. The authors previously demonstrated that internalization and
cytotoxicity are important virulence mechanisms in vibrio-fish epithelial cell
interactions. Adherence is a prerequisite for successful internalization. In this
study, the adherence capability of two invasive strains [V. anguillarum 811218-5W
and G/Virus/5(3)] was compared with that of two non-invasive strains [V. damselae
ATCC 33539 and V. anguillarum S2/5/93(2)] using adherence assays in three
different types of fish cells (epithelial papillosum of carp, EPC; grunt-fin
tissue, GF; and fat-head minnow epithelial cells, FHM). For all four strains
there was no significant difference (P>0.05) in the adherence to the different
cell lines. V. anguillarum 811218-5W exhibited the highest adherence, followed by
G/Virus/5(3) and S2/5/93(2); V. damselae ATCC 33539 showed the lowest adherence.
The super-adherence characteristic of V. anguillarum 811218-5W on EPC cells was
not affected by inhibitors, sugars, low temperature (4 degrees C) incubation, or
non-biological surfaces such as glass coverslips. The galactose-linked adherence
characteristic of V. anguillarum G/Virus/5(3) to the EPC cells was partially
inhibited by peptidase treatment of the fish cells, low-temperature incubation,
and addition of sugars that contained galactose (such as lactose and N-acetyl-D
galactosamine). De novo synthesis of bacterial protein, viable bacteria and
intact carbohydrate structure of vibrios were required for both super-adherence
and galactose-linked adherence. These adherence characteristics were also found
in ten other invasive vibrios, and galactose-linked adherence was found in nine
invasive vibrios.
PMID- 10784058
TI - Molecular analysis of genetic differences between virulent and avirulent strains
of Aeromonas hydrophila isolated from diseased fish.
AB - Aeromonas hydrophila, a normal inhabitant of aquatic environments, is an
opportunistic pathogen of a variety of aquatic and terrestrial animals, including
humans. A. hydrophila PPD134/91 is defined as virulent whereas PPD35/85 is
defined as avirulent on the basis of their different LD50 values in fish.
Suppression subtractive hybridization (SSH) was used to identify genetic
differences between these two strains. Sixty-nine genomic regions of differences
were absent in PPD35/85, and the DNA sequences of these regions were determined.
Sixteen ORFs encoded by 23 fragments showed high homology to known proteins of
other bacteria. ORFs encoded by the remaining 46 fragments were identified as new
proteins of A. hydrophila, showing no significant homology to any known proteins.
Among these PPD134/91-specific genes, 22 DNA fragments (21 ORFs) were present in
most of the eight virulent strains studied but mostly absent in the seven
avirulent strains, suggesting that they are universal virulence genes in A.
hydrophila. The PPD134/91-specific genes included five known virulence factors of
A. hydrophila: haemolysin (hlyA), protease (oligopeptidase A), outer-membrane
protein (Omp), multidrug-resistance protein and histone-like protein (HU-2).
Another 47 DNA fragments (44 ORFs) were mainly present in PPD134/91, indicating
the heterogeneity among motile aeromonads. Some of these fragments encoded
virulence determinants. These included genes for the synthesis of O-antigen and
type II restriction/modification system. The results indicated that SSH is
successful in identifying genetic differences and virulence genes among different
strains of A. hydrophila.
PMID- 10784059
TI - The gene encoding P27 lipoprotein and a putative antibiotic-resistance gene form
an operon in Mycobacterium tuberculosis and Mycobacterium bovis.
AB - P27 is an antigenic membrane lipoprotein synthesized by members of the
Mycobacterium tuberculosis complex. Northern blotting and RT-PCR experiments
indicated that the genes encoding P27 and a putative antibiotic transporter (P55)
form an operon. A promoter region was identified and characterized by deletion
analysis in Mycobacterium smegmatis. Two transcription initiation points were
mapped in Mycobacterium bovis BCG by primer extension analysis to 76 bp and 87 bp
upstream of the ATG initiation codon. Putative -10 and -35 promoter consensus
sequences associated with these showed 66% similarity to previously identified
mycobacterial promoters. These results suggest that the P27/P55 operon is
transcribed from two promoters in M. bovis BCG.
PMID- 10784060
TI - In vitro characterization of porcine hepatocyte function.
AB - The clinical consequences of acute liver failure are associated with high
mortality. Intensive medical intervention is required to treat the symptoms of
liver failure, including coagulopathy, metabolic instability, and encephalopathy.
Providing temporary liver support with an extracorporeal liver assist device
could stabilize the patient until a donor liver became available or the patient's
own liver was able to recover. The use of human hepatocytes as the biologic
component of the assist device is precluded by the scarcity of available tissue
and the limited proliferative potential of adult hepatocytes in vitro.
Consequently, porcine hepatocytes are being evaluated as a cell source for liver
assist devices. Maintaining differentiated function in isolated hepatocytes,
however, remains a challenge in the development of this technology and is
complicated by the fact that the key therapeutic functions for short-term
survival have not been well defined. Several approaches have been effective in
prolonging rodent hepatocyte function in vitro, including manipulation of
extracellular matrix. Here, we have investigated porcine hepatocyte function in
vitro with a specific emphasis on the response to exogenous collagen matrix. In
control cultures, albumin secretion increased during the first 7-10 days of
culture to an average of 50 +/- 17 microg/day/10(6) cells and then decreased over
the next 2 weeks. The pattern of urea synthesis was slightly different in that it
was highest in the first 1-3 days postisolation (140 +/- 19 microg/day/10(6)
cells) and then decreased by about 50% to a plateau level that was stable during
the next 3-4 weeks of culture. Cytochrome P450-mediated activities were the most
labile with time in culture and were undetectable after the first week in the
absence of pharmacological inducers. In contrast to results reported for rat
cells, porcine hepatocytes exhibited differentiated function in the absence of
any modification of the culture dish surface and function was not increased or
prolonged in the presence of exogenous collagen.
PMID- 10784061
TI - Optimal insulin treatment in syngeneic islet transplantation.
AB - Insulin-induced normoglycemia has shown to have a beneficial effect on the
outcome of pancreatic islets transplanted to diabetic recipients. The aim of the
study was to identify the insulin treatment that can maximize its beneficial
effect on islet transplants. Six groups of streptozotocin diabetic C57Bl/6 mice
were transplanted (Tx) with 100 syngeneic islets, an insufficient beta cell mass
to restore normoglycemia, and were treated with insulin as follows: group 1 (n =
9): from day 10 before Tx to day 14 after Tx; group 2 (n = 11): from day 6 before
Tx to Tx day; group 3 (n = 11): from Tx day to day 6 after Tx; group 4 (n = 7):
from Tx day to day 14 after Tx; group 5 (n = 8): from day 10 to day 24 after Tx;
group 6 (n = 18): Tx mice were not treated with insulin. Sixty days after Tx,
normoglycemia was achieved in 100% of mice in groups 1, 4, and 5, in 73% of mice
in group 2, and in only 45% and 33% of mice in groups 3 and 6, respectively (p <
0.01). Intraperitoneal glucose tolerance, determined only in normoglycemic mice,
was similar in groups 1, 2, 4, and normal controls. In contrast, normoglycemic
mice from groups 3, 5, and 6, exposed to more severe and prolonged hyperglycemia
after Tx, showed higher glucose values after glucose injection, suggesting that
hyperglycemia had a long-lasting deleterious effect on transplanted beta cell
function. The initially transplanted beta cell mass was maintained in the grafts
of normoglycemic mice, but was severely reduced in hyperglycemic mice.
Transplanted beta cell mass was similar in normoglycemic groups with normal or
impaired glucose tolerance, indicating that impaired glucose tolerance was not
due to reduced beta cell mass. In summary, the beneficial effect of insulin
induced normoglycemia on transplanted islets was maximal when insulin treatment
was maintained the initial 14 days after transplantation. Exposure to sustained
hyperglycemia initially after transplantation had a long-lasting deleterious
effect on transplanted islets.
PMID- 10784062
TI - The risks of total pancreatectomy and splenic islet autotransplantation.
AB - The intraportal site is the most common site for islet transplantation. Many
other sites have been tried experimentally, including the spleen, which has
successfully lead to insulin independence in a number of animal models.
Nevertheless, there are no detailed reports of total pancreatectomy and splenic
islet autotransplantation in humans. Five patients underwent total pancreatectomy
and splenic islet autotransplantation for chronic pancreatitis. Four patients had
a pylorus-preserving total pancreatectomy and one patient a duodenal-preserving
pancreatectomy. In three cases islets were embolized into both the portal vein
and spleen. Two patients received splenic islet transplants alone. Islets were
transplanted by retrograde venous infusion via the short gastric veins (n = 3),
splenic vein stump (n = 1), and the left gastroepiploic vein (n = 1). The total
volumes of transplanted pancreatic digest in those receiving combined intraportal
and splenic autografts (n = 3) were 15.8, 13.0, and 13.5 ml. The volumes in those
receiving a splenic-alone autograft (n = 2) were 12.0 and 5 ml. The mean rise in
portal pressure was 18 cm of water. Complications related to the splenic
autograft included a wedge splenic infarct, an emergency splenectomy, and a
portal vein thrombosis in one patient having a combined intraportal and splenic
autograft. Two patients developed insulin independence. two patients were still
insulin independent at 1-year follow-up, and all had normal HbA1c levels (mean
5.6, range 5.2-6.3). Splenic islet autotransplantation, after total
pancreatectomy, does lead to insulin independence. However, in our experience the
combined procedure has a high morbidity because of splenic infarction and venous
thrombosis.
PMID- 10784063
TI - Chitosan-polyvinyl pyrrolidone hydrogels as candidate for islet immunoisolation:
in vitro biocompatibility evaluation.
AB - The success of immunoisolation devices for islet transplantation depends on the
nature of semipermeable membranes, which permit the crossover of micronutrients,
glucose, and insulin and prevent the entry of immunocytes and other transplant
rejection mechanisms. In the present study we examined the properties of chitosan
polyvinyl pyrrolidone (PVP) hydrogels for possible application as an
immunoisolation device. Hydrogels with two different proportions of chitosan-PVP
(M1 1:1 and M2 2:1, v/v) were synthesized by cross-linking with glutaraldehyde.
Hydrogels were characterized for their hydrophilic nature, protein adsorption,
diffusion properties, cytotoxicity, and islet compatibility. Hydrogel membranes
were found to be hydrophilic as determined by high octane contact angle value
(M1: 142.9 +/- 0.46; M2: 143.6 +/- 0.49). Protein adsorption on the hydrogels was
found to be low (0.0143 +/- 0.0027 mg for M1 and 0.0136 +/- 0.0049 mg for M2)
compared to tissue culture polystyrene (TCPS) (0.0434 +/- 0.001 mg) and pure
chitosan (0.0214 +/- 0.0025 mg) control. Hydrogel M1 was tested as a
representative for diffusion studies. M1 allowed regulated transport of insulin
and did not allow anti-insulin antibodies to pass through. In vitro
biocompatibility of M1 and M2 was found to be excellent with no cytotoxic effects
on the HeLa cells as determined by MTT and NR assay. Mouse islets cultured on the
hydrogel membranes retained their integrity and intact morphology as assessed by
image analysis study. Viability of islets cultured on hydrogels was comparable to
that of controls (M1: 97%; M2: 90.4%) as assessed by trypan blue dye exclusion
test. Islets retained their functionality when cultured on hydrogels, as judged
by insulin secretion in response to glucose challenge (16.0 mM). Although in vivo
experiments are awaited, the present study provides sufficient documentation to
consider chitosan-PVP membranes as potential candidates for immunoisolation of
islets.
PMID- 10784064
TI - Storage and microencapsulation of islets for transplantation.
AB - Microencapsulation is an effective means of immunoisolation for pancreatic islet
transplants. However, the process of isolating, purifying, encapsulating, and
transplanting islets in a single day is labor intensive and difficult for routine
use. There is an apparent need for reliable methods of islet storage, and
cryopreservation has emerged as an attractive system of islet banking. While
studies have shown that cryopreserved islets are viable when tested
unencapsulated after thawing, it is not clear if the combination of freezing and
encapsulation would affect islet function. The purpose of the present study was
to determine the in vitro function of cryopreserved islets following thawing and
microencapsulation. Islets were isolated from the pancreata of Sprague-Dawley
rats and cryopreserved under liquid nitrogen for either 1 week or 1 month,
following an overnight culture at 37 degrees C. Upon thawing, the islets were
tested either unencapsulated or after encapsulation in polylysine-alginate
membrane. In all experiments islets were preperifused for 1 h at 37 degrees C
with a modified Krebs-Ringer bicarbonate buffer containing 3.3 mM (60 mg/dl)
glucose and maintained at pH 7.4 by continuous gassing with 95% air/5% CO2.
Following basal effluent sample collection on ice, the glucose concentration was
raised to 16.7 mM (300 mg/dl). It was found that, within 10 min of high glucose
stimulation, an average of twofold increase in insulin secretion (p < 0.01) was
obtained in islets within or without microcapsules. We conclude that islets
cryopreserved for 1 month prior to thawing and microencapsulation retained
functional viability as determined in in vitro experiments.
PMID- 10784065
TI - Chemotaxis activation of peritoneal murine macrophages induced by the
transplantation of free and encapsulated pancreatic rat islets.
AB - The present study concerns the influence of the transplantation of free and
encapsulated (AN69 membrane, Hospal) islets on the chemotaxis of peritoneal
macrophages. Fifty free or encapsulated rat islets, cultured for 24 h, were
transplanted in the peritoneal cavity of mice (n = 12). Three days after
transplantation, the chemotaxis of peritoneal murine macrophages was tested
towards formyl-methionyl-leucyl-phenylalanine (fMLP) and a culture medium
conditioned for 3 days by free rat islets isolated from the same rat donor. In
response to fMLP, the chemotactic indexes of macrophages from mice transplanted
with free or encapsulated islets were 8.09 +/- 2.10 and 9.45 +/- 2.76,
respectively. These values were significantly higher than those obtained when
macrophages from untreated mice were tested (2.42 +/- 0.23; p < 0.01). In
response to culture medium conditioned by free islets, the transplanted
encapsulated islets failed to enhance macrophage chemotaxis (2.41 +/- 0.53)
compared to transplanted free islets (7.00 +/- 2.63; p < 0.01). Thus,
encapsulation decreased the specific chemotactic activity of peritoneal
macrophages induced by free islet transplantation, probably by prohibiting the
diffusion of chemoattractants.
PMID- 10784066
TI - Increased survival of dopaminergic neurons in striatal grafts of fetal ventral
mesencephalic cells exposed to neurotrophin-3 or glial cell line-derived
neurotrophic factor.
AB - The transplantation of fetal mesencephalic cell suspensions into the brain
striatal system is an emerging treatment for Parkinson's disease. However, one
objection to this procedure is the relatively poor survival of implanted cells.
The ability of neurotrophic factors to regulate developmental neuron survival and
differentiation suggests they could be used to enhance the success of cerebral
grafts. We studied the effects of neurotrophin-3 (NT-3) or glial cell line
derived neurotrophic factor (GDNF) on the survival of dopaminergic neurons from
rat fetal ventral mesencephalic cells (FMCs) implanted into the rat striatum. Two
conditions were tested: (a) incubation of FMCs in media containing NT-3 and GDNF,
prior to grafting, and (b) co-grafting of FMCs with cells engineered to
overexpress high levels of NT-3 or GDNF. One week after grafting into the rat
striatum, the survival of TH+ neurons was significantly increased by pretreatment
of ventral mesencephalic cells with NT-3 or GDNF. Similarly, co-graft of ventral
mesencephalic cells with NT-3- or GDNF-overexpressing cells, but not the mock
transfected control cell line, increased the survival of graft-derived
dopaminergic neurons. Interestingly, we also found that co-grafting of GDNF
overexpressing cells was less effective than NT-3 at improving the survival of
fetal dopaminergic neurons in the grafts, and that only GDNF induced intense TH
immunostaining in fibers and nerve endings of the host tissue surrounding the
implant. Thus, our results suggest that NT-3, by strongly enhancing survival, and
GDNF, by promoting both survival and sprouting, may improve the efficiency of
fetal transplants in the treatment of Parkinson's disease.
PMID- 10784067
TI - Survival, neuronal differentiation, and fiber outgrowth of propagated human
neural precursor grafts in an animal model of Huntington's disease.
AB - Expanded neural precursor cells provide an attractive alternative to primary
fetal tissue for cell replacement therapies in neurodegenerative diseases. In
this study we transplanted epigenetically propagated human neural precursor cells
into a rat model of Huntington's disease. Neural precursors survived
transplantation and large numbers differentiated to express neuronal antigens,
including some that expressed DARPP-32, indicating a mature striatal phenotype
had been adopted. Neuronal fibers from the grafts projected diffusely throughout
the host brain, although there was no evidence that outgrowth was specifically
target directed. This study supports the contention that propagated human neural
precursors may ultimately be of use in therapeutic neural transplantation
paradigms for diseases such as Huntington's disease.
PMID- 10784068
TI - Volume and differentiation of striatal grafts in rats: relationship to the number
of cells implanted.
AB - A growing body of evidence suggests that graft-mediated functional recovery in
animal models of Huntington's disease is influenced by the morphology of the
striatal grafts. Various parameters, including embryonic dissection, tissue
preparation, and surgical delivery into the brain, have been investigated with
the aim of increasing the proportion of the grafts comprising striatum-like
tissue. While growing evidence suggests that implants derived from the selective
dissection of the lateral ganglionic eminence (LGE) contain more striatal tissue,
the relationship between the quantity of LGE tissue implanted and the striatum
like proportion of the resultant grafts has not been formally investigated. In
this study the volume of striatum-like tissue within the grafts did not increase
in a linear manner with increasing numbers of cells implanted. The proportion of
the grafts that comprised the striatum-like patch compartment or P-zone remained
constant after an initial rapid increase as the number of LGE cells implanted was
increased. These results have important practical implications in determining the
optimum number of LGE cells to implant and hence in the design of any surgical
protocol for the clinical application of this technique.
PMID- 10784069
TI - Pretreatment with MK-801 or the lazaroid U-83836E does not enhance striatal graft
survival.
AB - A large proportion of grafted striatal neurons die, and mechanisms by which they
succumb may involve excitotoxicity and oxidative stress. We investigated the
effects of pretreatment of the graft tissue with the N-methyl-D-aspartate (NMDA)
receptor antagonist (+)dizocilpine hydrogen maleate (MK-801) and lipid
peroxidation inhibitor lazaroid U-83836E on the survival of transplanted striatal
neurons. Neither compound increased the survival of grafts, suggesting that NMDA
related excitotoxicity or oxidative stress may not be primary mediators of cell
death in striatal grafts.
PMID- 10784071
TI - Branched hybrid vessel: in vitro loaded hydrodynamic forces influence the tissue
architecture.
AB - This study was conducted to investigate how a continuous load of hydrodynamic
stresses influences the tissue architecture of a branched hybrid vessel in vitro.
Tubular hybrid medial tissue of small (3 mm) and large (6 mm) diameters, prepared
by thermal gelation of a cold mixed solution of bovine smooth muscle cells (SMCs)
and type I collagen in glass molds, was assembled into a branched hybrid medial
tissue by end-to-side anastomosis. After a 2-week culture period, bovine
endothelial cells (ECs) were seeded onto the luminal surface. The branched hybrid
vessel was connected to a mock circulatory loop system and tested for two modes
of flow: 1) low flow rate for 24 h, 2) high flow rate for 24 or 72 h. After
exposure to a low flow rate for 24 h, cobblestone appearance of the ECs was
dominant. After exposure to a high flow rate, EC alignment in the direction of
flow was observed in the branch region, except at the region of predicted flow
separation where ECs retained their polygonal configuration. Elongation of SMCs
with no preferential orientation was observed in the case of vessels exposed to a
high flow rate for 24 h, and circumferential orientation was prominent in those
exposed to a high flow rate for 72 h. On the other hand, collagen fibrils
exhibited no preferential orientation in either case. After injection of Evans
blue-albumin conjugate into the circulating medium, the luminal surface of the
hybrid vessel exposed to a high flow rate for 24 h was examined by confocal laser
scanning microscopy. The fluorescence intensity was low at the high shear zone in
the branch region, while at the flow separation region it was very high,
indicating the increased albumin permeability at the latter region. These
findings reflect region-specific tissue architecture in the branch region, in
response to the local flow pattern, and may provide an in vitro atherosclerosis
model as well as a fundamental basis for the development of functional branched
hybrid grafts.
PMID- 10784070
TI - Intrathecal grafting of unencapsulated adrenal medullary tissue can bring CD4 T
lymphocytes into CSF: a potentially deleterious event for the graft.
AB - Adrenal medullary tissue including chromaffin cells was grafted intrathecally in
cancer patients to relieve intractable pain. The central nervous system (CNS) is
considered an immune privileged site. Therefore, non-HLA-matched and
unencapsulated tissue was grafted in 15 patients and 1 sham control in a series
of at least 20 grafts. We observed an increase in CSF lymphocyte counts in 15/20
allografts (75%). In contrast to peripheral blood, CD4 T cells predominated in
the CSF, but failed to exhibit an activated phenotype (CD25+ CD45RO+ HLA-DR+).
The positive effect of graft on pain, the high met-enkephalin levels, the absence
of any increase in CSF cytokine levels particularly for IFN-gamma or IL-2 (but
not IL-10 and IL-6), indirectly indicated that the graft was tolerated despite
the presence of CSF lymphocytes. The single treatment failure and three of four
cases of partial efficacy occurred in grafts where CSF lymphocytes were present.
Moreover, when assayed (n = 7), the CD4+ CSF lymphocytes still retained the
capacity to exhibit ex vivo a normal or enhanced frequency of T CD4 cells
producing IFN-gamma and IL-2. Taken together, our observations indicate that
impairment of the local immunosuppressive balance can lead to activation of those
CSF CD4 T cells and drive a rejection process. This study suggests further work
on the purification and/or the immunoisolation of tissues grafted in the CNS will
be necessary, particularly when the possibility of long-term and repeated
grafting is considered.
PMID- 10784072
TI - Longitudinal studies on the microcirculation around the TheraCyte immunoisolation
device, using the laser Doppler technique.
AB - Encapsulation of cellular grafts in an immunoisolation membrane device may make
it possible to perform transplantation without having to give immunosuppressive
drugs. A common problem is the development of an avascular fibrotic zone around
the implants, leading to impaired graft survival. The TheraCyte
macroencapsulation device has therefore been designed to facilitate
neovascularization of the device's surface. In this study, we evaluated the
microcirculation around empty TheraCyte devices implanted SC in rats at various
times after implantation, using a laser Doppler probe introduced via the device
port. Studies were performed on day 1 or at 1, 2, and 4 weeks or at 2, 3, and 12
months after implantation. The mean flow was 158+/-42, 148+/-50, 133+/-28, 72+/
17, 138+/-41, 165+/-43, and 160+/-29 perfusion units (PU), respectively. Thus,
the microcirculation around the device was significantly reduced at 4 weeks after
implantation (p < 0.01) while, from 2 months onwards the circulation had improved
and did not differ significantly from that on day 1. The present study shows time
related changes in the microcirculatory flow around TheraCyte macroencapsulation
devices that agree with our previous microdialysis studies on in vivo exchange of
insulin and glucose between the device and the circulation. Laser Doppler
flowmetry seems to provide a reliable technique for screening blood perfusion
around macroencapsulation devices.
PMID- 10784073
TI - Improved vascularization of planar membrane diffusion devices following
continuous infusion of vascular endothelial growth factor.
AB - Improving blood vessel formation around an immunobarrier device should improve
the survival of the encapsulated tissue. In the present study we investigated the
formation of new blood vessels around a planar membrane diffusion device (the
Baxter Theracyte System) undergoing a continuous infusion of vascular endothelial
growth factor through the membranes and into the surrounding tissue. Each device
(20 microl) had both an inner immunoisolation membrane and an outer vascularizing
membrane. Human recombinant vascular endothelial growth factor-165 was infused at
100 ng/day (low dose: n = 6) and 500 ng/day (high dose: n = 7) for 10 days into
devices implanted s.c. in Sprague-Dawley rats; noninfused devices transplanted
for an identical period were used as controls (n = 5). Two days following the
termination of VEGF infusion, devices were loaded with 20 microl of Lispro
insulin (1 U/kg) and the kinetics of insulin release from the lumen of the device
was assessed. Devices were then explanted and the number of blood vessels
(capillary and noncapillary) was quantified using morphometry. High-dose vascular
endothelial growth factor infusion resulted in two- to threefold more blood
vessels around the device than that obtained with the noninfused devices and
devices infused with low-dose vascular endothelial growth factor. This increase
in the number of blood vessels was accompanied by a modest increase in insulin
diffusion from the device in the high-dose vascular endothelial growth factor
infusion group. We conclude that vascular endothelial growth factor can be used
to improve blood vessel formation adjacent to planar membrane diffusion devices.
PMID- 10784074
TI - Effects of flt-3 ligand in combination with TPO on the expansion of
megakaryocytic progenitors.
AB - As an early acting growth factor, flt-3 ligand (FL) promotes the ex vivo
expansion of hematopoietic stem and progenitor cells. The effect and mechanism of
FL on the development of the megakaryocytic lineage remain unclear. In this
study, we compared the effects of FL and stem cell factor (SCF) in combination
with other megakaryocyte-promoting cytokines on the differentiation and
proliferation of megakaryocytic progenitors and investigated the expression of
flt-3 receptors on megakaryocytic cell lines. In liquid cultures of enriched
CD34+ cells from human umbilical cord blood for 14 days, FL plus thrombopoietin
(TPO), interleukin-3 (IL-3), and IL-6 promoted the expansion of nucleated cells,
CD34+ cells, CD34+ CD38- cells, and megakaryocyte colony-forming units (CFU-MK)
by 300 +/- 115-, 23.8 +/- 11.3-, 33.9 +/- 28.6-, and 584 +/- 220-fold,
respectively. Replacing FL with SCF significantly decreased the yield of all cell
types. Using murine bone marrow (BM) cells, we demonstrated that FL at a range of
0-100 ng/ml had no significant mitogenic effect on CFU-MK formation. TPO
increased CFU-MK (p < 0.001) but the effect was not significantly modified by FL.
While one human acute lymphoblastic leukemia sample expressed high levels of flt
3 receptor, the four megakaryocytic cell lines (Meg-01, CHRF-288-11, M-07e, and
Dami) did not show any positive expression. Our data suggest that the present
cytokine combination and expansion conditions provide an effective and
potentially useful system for the clinical expansion of cord blood for bone
marrow transplantation (BMT). FL alone did not stimulate megakaryocytopoiesis,
possibly due to the lack of receptor expression on megakaryocytes. The effect of
FL in augmenting the expansion of CFU-MK in liquid culture might be due to the
early action of FL at the pluripotent stem cell stage.
PMID- 10784075
TI - The assessment and treatment of Post-traumatic Stress Disorder in children and
adolescents.
AB - Post-traumatic Stress Disorder (PTSD) is a syndrome defined by the intrusive re
experiencing of a trauma, avoidance of traumatic reminders, and persistent
physiological arousal. PTSD is associated with high levels of comorbidity and may
increase the risk for additional disorders over time. While controversies remain
regarding the applicability of the PTSD criteria to very young children, it has
proved to be a useful framework for guiding assessment and treatment research
with older children and adolescents. This article presents an overview of the
literature on the clinical characteristics, assessment, and treatment of PTSD in
children and adolescents.
PMID- 10784076
TI - School and neuropsychological performance of evacuated children in Kyiv 11 years
after the Chornobyl disaster.
AB - This paper examines the cognitive and neuropsychological functioning of children
who were in utero to age 15 months at the time of the Chornobyl disaster and were
evacuated to Kyiv from the 30-kilometer zone surrounding the plant. Specifically,
we compared 300 evacuee children at ages 10-12 with 300 non-evacuee Kyiv
classmates on objective and subjective measures of attention, memory, and school
performance. The evacuee children were not significantly different from their
classmates on the objective measures (grades; Symbolic Relations subtest of the
Detroit Test; forms 1 and 2 of the Visual Search and Attention Test; Benton Form
A; Trails A; Underline the Words Test) or on most of the subjective measures (the
attention subscale of the Child Behavior Checklist completed by mothers; the
attention items of the Iowa Conners Teacher's Rating Scale; mother and child
perceptions of school performance). The one exception was that 31.3% of evacuee
mothers compared to 7.4% of classmate mothers indicated that their child had a
memory problem. However, this subjective measure of memory problems was not
significantly related to neuropsychological or school performance. No significant
differences were found in comparisons of evacuees and classmates who were in
utero at the time of the explosion, children from Pripyat vs. other villages in
the 30-kilometer zone, and children manifesting greater generalized anxiety. For
both groups, children with greater Chornobyl-focused anxiety performed
significantly worse than children with less Chornobyl-focused anxiety on measures
of attention. The results thus fail to confirm two previous reports that
relatively more children from areas contaminated by radiation had cognitive
deficits compared to controls. Possible reasons for the differences in findings
among the studies are discussed.
PMID- 10784078
TI - Social functioning in children with a chronic illness.
AB - Behavioural, cognitive, and affective aspects of social functioning of 107
children with a chronic illness were studied. The aim of the study was twofold:
(1) to describe peer interaction of children with a chronic illness in comparison
with normative data of healthy children; (2) to examine whether peer interaction
was related to the illness characteristics physical restrictions and pain. Peer
interaction was assessed with measures of social activities (CBCL), parent
reported social skills (CABS), child-reported social skills (MESSY), social self
esteem (SPPC), and social anxiety (SASK). Results showed no differences between
diagnosis groups, suggesting that the social consequences of chronic illness are
not diagnosis specific. Compared with healthy norms, chronically ill children
reported less aggressive behaviour. The parent-report measures suggested a
similar trend. Children with chronic illness also tended to display more
submissive behaviour than healthy norms, as perceived by their parents. With
regard to illness characteristics, both physical restrictions and pain were
associated with restricted social activities, but not with other measures of
social peer interaction. Children who display submissive behaviour and children
who are restricted in their social activities should receive extra attention
because they are especially vulnerable for problems in their social development.
PMID- 10784077
TI - The mental health of the peers of suicide completers and attempters.
AB - This study examined the prevalence and risk of psychiatric disturbances and
suicidal behaviours among the peers of suicide attempters and completers. The
subjects were selected from high schools with and without history of student
suicides in the past 3 years. The psychiatric disturbances (as measured by the
YSR and CBCL), suicidal behaviours, drug use, and a wide range of potential risk
factors were measured. About a quarter of the peers of suicide completers and
attempters were probable psychiatric cases and 15-21% of them reported suicidal
acts. The increased risk of psychiatric disturbances and suicidal behaviours were
still evident after controlling for age, sex, and potential risk factors. The
presence of psychiatric disturbances could not wholly account for the increased
odds of suicidal behaviours. Peers of suicide attempters carried a higher risk
than peers of suicide completers. The close friends of suicide completers were
particularly at risk of internalising problems, whereas the close friends of
suicide attempters were at high risk of externalising problems. The peers of
suicide completers and attempters represent a high-risk group for psychiatric
disturbances and suicidal behaviours. The specific association of different types
of psychiatric disturbances in the peers of suicide completers and attempters
suggested that different risk mechanisms might be in operation within these peer
groups.
PMID- 10784079
TI - Multi-method psycho-educational intervention for preschool children with
disruptive behavior: preliminary results at post-treatment.
AB - Annual screenings of preschool children at kindergarten registration identified
158 children having high levels of aggressive, hyperactive, impulsive, and
inattentive behavior. These "disruptive" children were randomly assigned to four
treatment conditions lasting the kindergarten school year: no treatment, parent
training only, full-day treatment classroom only, and the combination of parent
training with the classroom treatment. Results showed that parent training
produced no significant treatment effects, probably owing largely to poor
attendance. The classroom treatment produced improvement in multiple domains:
parent ratings of adaptive behavior, teacher ratings of attention, aggression,
self-control, and social skills, as well as direct observations of externalizing
behavior in the classroom. Neither treatment improved academic achievement skills
or parent ratings of home behavior problems, nor were effects evident on any lab
measures of attention, impulse control, or mother-child interactions. It is
concluded that when parent training is offered at school registration to parents
of disruptive children identified through a brief school registration screening,
it may not be a useful approach to treating the home and community behavioral
problems of such children. The kindergarten classroom intervention was far more
effective in reducing the perceived behavioral problems and impaired social
skills of these children. Even so, most treatment effects were specific to the
school environment and did not affect achievement skills. These findings must be
viewed as tentative until follow-up evaluations can be done to determine the long
term outcomes of these interventions.
PMID- 10784080
TI - Cognitive and familial contributions to conduct disorder in children.
AB - Although young children with conduct disorder (CD) are suspected of having verbal
and executive function deficits, most studies that investigated this hypothesis
did not control for attention deficit hyperactivity disorder (ADHD). Furthermore,
relatively little is known about the interaction between cognitive deficits and
familial factors in explaining the onset and persistence of CD in children. The
participants in this study were 57 children with CD and 35 controls aged 7 to 12
years. At 1-year follow-up, 41 of the participants with CD were reassessed.
Children with CD were found to be significantly impaired in four of five
executive function measures after ADHD symptoms and socioeconomic status (SES)
were controlled. Executive function test performance, number of ADHD symptoms,
and familial characteristics (SES, parental punishment) together correctly
classified 90% of the participants. Only the number of ADHD symptoms was found to
significantly improve prediction of CD 1 year later beyond that afforded by
number of CD symptoms a year earlier. Findings indicate that children with CD and
ADHD symptoms are especially at risk for persistent antisocial behaviour. Results
also highlight the importance of treatment programs that cover both cognitive and
familial aspects associated with CD.
PMID- 10784081
TI - Gender self-concept profiles of adolescents suspended from high school.
AB - The gender self-concept profiles of 128 adolescents (107 males) whose persistent
behaviour problems led to suspension from school were investigated. Establishing
the students' percentile ratings in the 11 subscales of the Self-Description
Questionnaire overcame previous methodological weaknesses. For boys and girls
Physical Appearance, Opposite-sex Relationships, and Honesty and Trustworthiness
were in the average range, but Parent Relationships, General Self, and General
School self-concepts were low. Only girls were low for Same-sex Relationships and
Emotional Stability. The profiles suggest that boys' antisocial behaviours are
associated with striving for a masculine self-image, but girls' antisocial
behaviours are associated with greater social marginalisation. The issues of
multi-focused interventions, prosocial role models, the particular needs of
girls, and the relationship between self-control, self-enhancement, and
reputation enhancement theories are discussed.
PMID- 10784082
TI - The interface between ADHD and language impairment: an examination of language,
achievement, and cognitive processing.
AB - Language impairments are commonly observed among children referred for
psychiatric services. The most frequent psychiatric diagnosis of children with
language impairment (LI) is Attention Deficit Hyperactivity Disorder (ADHD). It
is not clear whether there are differences between children with ADHD and
comorbid LI and children with other psychiatric disorders who are also comorbid
for LI. In the present study the language, achievement, and cognitive processing
characteristics of 166 psychiatrically referred 7-14-year-old children were
examined using a 2 x 2 (ADHD, LI) design to examine four groups: children with
ADHD + LI, children with ADHD who have normally developing language, children
with psychiatric diagnoses other than ADHD with a language impairment (OPD + LI)
or without a LI (OPD). Results indicated that children with LI were at the most
disadvantage regardless of the nature of the psychiatric diagnosis. Contrary to
prediction, working memory measures, used to tap the core cognitive deficit of
ADHD in executive functions, were more closely associated with LI than with ADHD.
It was concluded that caution must be exercised in attributing to children with
ADHD what might be a reflection of problems for children with language impairment
generally. As most therapies are verbally based it is notable that language
competence is rarely evaluated systematically before such therapies are
undertaken.
PMID- 10784083
TI - Lack of attentional bias for emotional information in clinically depressed
children and adolescents on the dot probe task.
AB - The present study utilised a cognitive paradigm to investigate attentional biases
in clinically depressed children and adolescents. Two groups of children and
adolescents--clinically depressed (N = 19) and normal controls (N = 26)--were
asked to complete a computerised version of the attentional dot probe paradigm
similar to that used by MacLeod, Mathews, and Tata (1986). Results provided no
support for an attentional bias, either toward depression-related words or threat
words, in the depressed group. This finding is discussed in the context of
cognitive theories of anxiety and depression.
PMID- 10784084
TI - Verbal bias in recognition of facial emotions in children with Asperger syndrome.
AB - Thirteen children and adolescents with diagnoses of Asperger syndrome (AS) were
matched with 13 nonautistic control children on chronological age and verbal IQ.
They were tested on their ability to recognize simple facial emotions, as well as
facial emotions paired with matching, mismatching, or irrelevant verbal labels.
There were no differences between the groups at recognizing simple emotions but
the Asperger group performed significantly worse than the control group at
recognizing emotions when faces were paired with mismatching words (but not with
matching or irrelevant words). The results suggest that there are qualitative
differences from nonclinical populations in how children with AS process facial
expressions. When presented with a more demanding affective processing task,
individuals with AS showed a bias towards visual-verbal over visual-affective
information (i.e., words over faces). Thus, children with AS may be utilizing
compensatory strategies, such as verbal mediation, to process facial expressions
of emotion.
PMID- 10784085
TI - Stability and change of attachment at 14, 24, and 58 months of age: behavior,
representation, and life events.
AB - Stability and change of attachment was examined longitudinally in a group of 48
children at 14, 24, and 58 months of age. Whereas attachment classifications
showed stability between 14 and 24 months, lack of stability was the case between
either 14 or 24 months and 58 months. Mothers of children who did not exhibit
stability of attachment reported more negative and less positive life events. No
correspondence was found between attachment classification at 14 or 24 months and
mental representations at 58 months. However there was agreement between
representational and behavioral measures of attachment at 58 months, where mental
representations of attachment appeared to mirror and complement behavioral
classification of the attachment relationship with the mother. Evidence for
continuity of attachment from infancy to childhood internal representations was
found only in a subgroup of children who showed stability of secure attachment
between infancy and 58 months of age. These children exhibited greater Emotional
Openness in the SAT at 4.5 years. Findings are discussed in terms of different
positions in attachment theory and research regarding the stability and change of
attachment relationships.
PMID- 10784086
TI - Knowledge of display rules in prelingually deaf and hearing children.
AB - Deaf children of elementary and secondary school age participated in a study
designed to examine their understanding of display rules, the principles
governing the expression and concealment of emotion in social situations. The
results showed that deaf children's knowledge of display rules, as measured by
their reported concealment of emotion, was comparable to that of hearing children
of the same age. However, deaf children were less likely to report that they
would conceal happiness and anger. They were also less likely to produce reasons
for concealing emotion and a smaller proportion of their reasons were prosocial,
that is, relating to the feelings of others. The results suggest that the
understanding of display rules (which function to protect the feelings of other
people) may develop more gradually in deaf children raised in a spoken language
environment than it does in hearing children.
PMID- 10784087
TI - Selective microstimulation of central nervous system neurons.
AB - The goal of this study was to identify stimulus parameters and electrode
geometries that were effective in selectively stimulating targeted neuronal
populations within the central nervous system (CNS). Cable models of neurons that
included an axon, initial segment, soma, and branching dendritic tree, with
geometries and membrane dynamics derived from mammalian motoneurons, were used to
study excitation with extracellular electrodes. The models reproduced a wide
range of experimentally documented excitation patterns including current-distance
and strength-duration relationships. Evaluation of different stimulus paradigms
was performed using populations of fifty cells and fifty fibers of passage
randomly positioned about an extracellular electrode(s). Monophasic cathodic or
anodic stimuli enabled selective stimulation of fibers over cells or cells over
fibers, respectively. However, when a symmetrical charge-balancing stimulus phase
was incorporated, selectivity was greatly diminished. An anodic first, cathodic
second asymmetrical biphasic stimulus enabled selective stimulation of fibers,
while a cathodic first, anodic second asymmetrical biphasic stimulus enabled
selective stimulation of cells. These novel waveforms provided enhanced
selectivity while preserving charge balancing as is required to minimize the risk
of electrode corrosion and tissue injury. Furthermore, the models developed in
this study can predict the effectiveness of electrode geometries and stimulus
parameters for selective activation of specific neuronal populations, and in turn
represent useful tools for the design of electrodes and stimulus waveforms for
use in CNS neural prosthetic devices.
PMID- 10784088
TI - Integrin-dependent human macrophage migration induced by oscillatory electrical
stimulation.
AB - Electrical stimulation has been used to promote wound healing. The mechanisms by
which such stimulation could interact with biological systems to accelerate
healing have not been elucidated. One potential mechanism could involve
stimulation of macrophage migration to the site of a wound. Here we report that
oscillatory electric fields induce human macrophage migration. Macrophages
exposed to a 1 Hz, 2 V/cm field show an induced migration velocity of 5.2+/-0.4 x
10(-2) microm/min and a random motility coefficient of 4.8+/-1.4 x 10(-2)
microm2/min on a glass substrate. Electric field exposure induces reorganization
of microfilaments from ring-like structures at the cell periphery to podosomes
that are confined to the contact sites between cell and substrate, suggesting
that the cells are crawling on glass. Treatment of cells with monoclonal
antibodies directed against beta2-integrins prior to field exposure prevents cell
migration, indicating that integrin-dependent signaling pathways are involved.
Electric fields cause macrophage migration on laminin or fibronectin coated
substrates without inducing podosome formation or changes in cellular morphology.
The migration velocity is not significantly altered but the random movement is
suppressed, suggesting that cell movements on a laminin- or fibronectin-coated
surface are not mediated by cell crawling. It is suggested that electric field
induced macrophage migration utilizes several modes of cell movement, including
cell crawling and possibly cell rolling.
PMID- 10784089
TI - Influence of the electric axis of stimulation on the induced transmembrane
potentials in ellipsoidal bidomain heart.
AB - This theoretical study was provoked by and designed to interpret, complement and
extend the implications of recent experimental observations by Wikswo and Lin
(PACE, 21:940, 1998) on the epicardial surface of rabbit hearts. Using a
macroscopic bidomain representation of the cardiac structure and the finite
element method, we model the response of the heart to uniform electric fields
applied under different angles. To overcome intra- and interspecies differences
in the geometric and structural characteristics of the cardiac muscle, the
analysis is conducted for an idealized ellipsoidal heart. Although idealized,
this heart model incorporates important structural features, i.e., fiber
curvature, transmural fiber rotation, and unequal anisotropy for the intra- and
extracellular domains. This study shows that regions of maximum polarization of
opposite sign may develop along an axis, significantly deviating from the axis of
the applied electric field. The polarization evoked inside the ventricular wall
seems to be a major contributor to this phenomenon. Nonperiodic structural
inhomogeneities on multicellular level (endocardial "trabeculation" in our model)
result in local unaligned polarization dipoles weakening the magnitude of the
global polarization dipole and reducing its deviation from the axis of
stimulation. Our results might be helpful in improving current understanding of
defibrillation mechanisms.
PMID- 10784091
TI - Theoretical evaluation of contributions of heat conduction and countercurrent
heat exchange in selective brain cooling in humans.
AB - The purpose of this work is to evaluate the capacity of the heat loss from the
carotid artery in the human neck and thus, to provide indirect evidence of the
existence of selective brain cooling in humans during hyperthermia. A theoretical
model is developed to describe the effects of blood flow rate and vascular
geometry on the thermal equilibration in the carotid artery based on the blood
flow and the anatomical vascular geometry in the human neck. The potential for
cooling of blood in the carotid artery on its way to the brain by heat exchange
with the jugular vein and by radial heat conduction loss to the cool neck surface
is evaluated. It is shown that the cooling of the arterial blood can be as much
as 1.1 degrees C lower than the body core temperature, which is in agreement with
previous experimental measurements of the difference between the tympanic and
body core temperatures. The model also evaluates the relative contributions of
countercurrent heat exchange and radial heat conduction to selective brain
cooling. It is found that these mechanisms are comparable with each other.
Results of the present study will help provide a better understanding of the
thermoregulation during hyperthermia.
PMID- 10784090
TI - Advection and diffusion of substances in biological tissues with complex vascular
networks.
AB - For highly diffusive solutes the kinetics of blood-tissue exchange is only poorly
represented by a model consisting of sets of independent parallel capillary
tissue units. We constructed a more realistic multicapillary network model
conforming statistically to morphometric data. Flows through the tortuous paths
in the network were calculated based on constant resistance per unit length
throughout the network and the resulting advective intracapillary velocity field
was used as a framework for describing the extravascular diffusion of a substance
for which there is no barrier or permeability limitation. Simulated impulse
responses from the system, analogous to tracer water outflow dilution curves,
showed flow-limited behavior over a range of flows from about 2 to 5 ml min(-1)
g(-1), as is observed for water in the heart in vivo. The present model serves as
a reference standard against which to evaluate computationally simpler, less
physically realistic models. The simulated outflow curves from the network model,
like experimental water curves, were matched to outflow curves from the commonly
used axially distributed models only by setting the capillary wall permeability
surface area (PS) to a value so artifactually low that it is incompatible with
the experimental observations that transport is flow limited. However, simple
axially distributed models with appropriately high PSs will fit water outflow
dilution curves if axial diffusion coefficients are set at high enough values to
account for enhanced dispersion due to the complex geometry of the capillary
network. Without incorporating this enhanced dispersion, when applied to
experimental curves over a range of flows, the simpler models give a false
inference that there is recruitment of capillary surface area with increasing
flow. Thus distributed models must account for diffusional as well as permeation
processes to provide physiologically appropriate parameter estimates.
PMID- 10784092
TI - Mathematical modeling of the human body during water replacement and dehydration:
body water changes.
AB - A model of the human body that integrates the variables involved in temperature
regulation and blood gas transport within the cardiovascular and respiratory
systems is presented here. It expands upon previous work to describe the
competition between skin and muscles when both require increased blood flows
during exercise and/or heat stress. First, a detailed study of the control
relations used to predict skin blood flow was undertaken. Four other control
relations employed in the model were also examined and modified as indicated by
empirical results found in literature. Internal responses to exercise and/or heat
stress can affect both thermoregulation and the cardiorespiratory system.
Dehydration was studied in addition to complete water replacement during similar
environmental and exercise situations. Control relations for skin blood flow and
evaporative heat loss were modified and a water balance was added to study how
the loss of water through sweat can be limiting. Runoff from sweating as a
function of relative humidity was introduced along with evaporation, and these
results were compared to data to validate the model.
PMID- 10784093
TI - True arterial system compliance estimated from apparent arterial compliance.
AB - A new method has been developed to estimate total arterial compliance from
measured input pressure and flow. In contrast to other methods, this method does
not rely on fitting the elements of a lumped model to measured data. Instead, it
relies on measured input impedance and peripheral resistance to calculate the
relationship of arterial blood volume to input pressure. Generally, this transfer
function is a complex function of frequency and is called the apparent arterial
compliance. At very low frequencies, the confounding effect of pulse wave
reflection disappears, and apparent compliance becomes total arterial compliance.
This study reveals that frequency components of pressure and flow below heart
rate are generally necessary to obtain a valid estimate of compliance. Thus, the
ubiquitous practice of estimating total arterial compliance from a single cardiac
cycle is suspect under most circumstances, since a single cardiac cycle does not
contain these frequencies.
PMID- 10784094
TI - The effect of celiac and renal artery outflows on near-wall velocities in the
porcine iliac arteries.
AB - The effects of the outflow of aortic blood through the celiac and renal arteries
on the flow field in the external iliac arteries were studied under steady and
physiologically realistic pulsatile flow conditions. Laser Doppler velocimetry
(LDV) measurements were made close to the medial, lateral, ventral, and dorsal
walls of the external iliac branches of a clear, flow-through replica of a
porcine aorta and its daughter vessels. The outflow from each branch of the
replica was controlled so that the infrarenal aortic flow rate and the flow
partition at the aortic trifurcation were the same for all experiments. LDV
measurements were made with flow exiting through both the renal and celiac artery
ostia, only the celiac ostium, and neither ostium. The steady flow results
indicate that while the outflow through the renal arteries did not have a
significant effect on near wall shear rate in the external iliac arteries, the
flow through the celiac artery did. However, in pulsatile flow, three indices of
near wall velocity in the iliac arteries were unaffected by celiac artery
outflow, while a fourth showed a small effect that can be attributed to
differences in minimum velocity. These results indicate that reliable simulations
of blood flow in the external iliac arteries can be carried out without including
the renal and celiac vessels, provided that the correct infrarenal flow wave is
used. They also demonstrate that the flow field downstream of a region, such as a
branch, that strongly alters the flow, can be nearly independent of the velocity
field entering the region.
PMID- 10784095
TI - A micromechanical model of airway-parenchymal interdependence.
AB - The forces of parenchymal interdependence in the lung are potent inhibitors of
airway smooth muscle shortening, as evidenced by the marked dependence of
bronchial responsiveness on lung volume. In this study we developed a
mathematical-computer model of the effects of parenchymal interdependence on
airway smooth muscle shortening. A three-dimensional network of cuboidal alveolar
walls was tethered at its boundaries and surrounded a single airway with
mechanical properties identical to the alveolar parenchyma. The walls were
assigned highly nonlinear properties so that the pressure-volume behavior of the
model matched that measured in dogs. Constriction of the airway was achieved by
increasing the circumferential tension in the airway wall, and then solving the
force-balance equations of the model to calculate the equilibrium configurations
of the airway wall and all the interconnecting alveolar walls. The changes in
airway resistance predicted by the model at various transpulmonary pressures
(P(tp)) were compared to those obtained by the alveolar capsule oscillator
technique in dogs during induced bronchoconstriction at various P(tp) (Balassy et
al., J. Appl. Physiol. 78:875-880, 1995). The model matched the data reasonably
well at P(tp) values above about 0.5 kPa, but was too responsive at lower P(tp).
We were able to make the model match the data at all P(tp) by including an
additional stiffness term, such as might conceivably arise from the airway wall
itself.
PMID- 10784096
TI - Finite element simulation of location- and time-dependent mechanical behavior of
chondrocytes in unconfined compression tests.
AB - Experimental evidence suggests that cells are extremely sensitive to their
mechanical environment and react directly to mechanical stimuli. At present, it
is technically difficult to measure fluid pressure, stress, and strain in cells,
and to determine the time-dependent deformation of chondrocytes. For this reason,
there are no data in the published literature that show the dynamic behavior of
chondrocytes in articular cartilage. Similarly, the dynamic chondrocyte mechanics
have not been calculated using theoretical models that account for the influence
of cell volumetric fraction on cartilage mechanical properties. In the present
investigation, the location- and time-dependent stress-strain state and fluid
pressure distribution in chondrocytes in unconfined compression tests were
simulated numerically using a finite element method. The technique involved two
basic steps: first, cartilage was approximated as a macroscopically homogenized
material and the mechanical behavior of cartilage was obtained using the
homogenized model; second, the solution of the time-dependent displacements and
fluid pressure fields of the homogenized model was used as the time-dependent
boundary conditions for a microscopic submodel to obtain average location- and
time-dependent mechanical behavior of cells. Cells and extracellular matrix were
assumed to be biphasic materials composed of a fluid phase and a hyperelastic
solid phase. The hydraulic permeability was assumed to be deformation dependent
and the analysis was performed using a finite deformation approach. Numerical
tests were made using configurations similar to those of experiments described in
the literature. Our simulations show that the mechanical response of chondrocytes
to cartilage loading depends on time, fluid boundary conditions, and the
locations of the cells within the specimen. The present results are the first to
suggest that chondrocyte deformation in a stress-relaxation type test may exceed
the imposed system deformation by a factor of 3-4, that chondrocyte deformations
are highly dynamic and do not reach a steady state within about 20 min of steady
compression (in an unconfined test), and that cell deformations are very much
location dependent.
PMID- 10784098
TI - Stent-induced thromboembolism.
PMID- 10784097
TI - Facilitated diffusion and membrane permeation of fatty acid in albumin solutions.
AB - Facilitated transport is characteristic of most living systems, and usually
involves a series of consecutive adjacent transfer regions, each having different
transport properties. As a first step in the analysis of the multiregional
problem, we consider in a single unstirred layer the facilitated diffusion of
fatty acid (F) in albumin (A) solution under conditions of slow versus rapid
association-dissociation, accounting for differing diffusivities of the albumin
fatty acid complex (AF). Diffusion gradients become established in an unstirred
layer between a source of constant concentration of A, AF, and F in equilibrium,
and a membrane permeable to F. The posited system does not reduce to a thin- or
thick-layer approximation. The transient state is prolonged by slower on/off
binding rates and by increasing the thickness of the unstirred layer. Solutions
to transient and steady state depend upon the choice of boundary conditions,
especially for thin regions. When there are two regions (each with its specific
binding protein) separated by a permeable membrane, the steady-state fluxes and
concentration profiles depend on the rates of association and dissociation
reactions, on the diffusion coefficients, local consumption rates, and on the
membrane permeability. Sensitivity analysis reveals the relative importance of
these mechanisms.
PMID- 10784099
TI - Calcium-independent release of [3H]spermine from chick retina.
AB - Spermine has been shown to influence NMDA receptor function through an
interaction at the coagonist site for glycine in the central nervous system (CNS)
and the retina. In order to support a role for spermine as neurotransmitter or
neuromodulator in the chick retina, specific stimulated-release of spermine
should be demonstrated. Isolated chick retinas, preloaded with [3H]spermine, were
stimulated with 1 mM NMDA and other glutamate agonists at ionotropic receptors,
in a continuous superfusion system. [3H]spermine was released from the retina by
depolarization with 50 mM KCl, in a Ca2+-independent manner. Inhibition of Na+/K+
ATPase by ouabain or digitoxigenin also induced spermine release following 36 min
in the presence of the drugs; such effect seems unrelated to changes in Na+
electrochemical gradients, since nigericin and veratrine did not induce release
in Na+ containing medium. The lack of effect of glutamate, NMDA and kainate at 1
mM concentration, suggests that release of spermine in the retina is mediated by
the reversal of uptake and not necessarily linked to EAA-receptor activation.
PMID- 10784100
TI - Preferential inhibition of L- and N-type calcium channels in the rat hippocampal
neurons by cilnidipine.
AB - The effect of a dihydropyridine Ca2+ antagonist, cilnidipine, on voltage
dependent Ca2+ channels was studied in acutely dissociated rat CA1 pyramidal
neurons using the nystatin-perforated patch recording configuration under voltage
clamp conditions. Cilnidipine had no effect on low-voltage-activated (LVA) Ca2+
channels at the low concentrations under 10(-6) M. On the other hand, cilnidipine
inhibited the high-voltage-activated (HVA) Ca2+ current (I(Ca)) in a
concentration-dependent manner and the inhibition curve showed a step-wise
pattern; cilnidipine selectively reduced only L-type HVA I(Ca) at the low
concentrations under 10(-7) and 10(-6) M cilnidipine blocked not only L- but also
N-type HVA I(Ca). At the high concentration over 10(-6) M cilnidipine non
selectively blocked the T-type LVA and P/Q- and R-type HVA Ca2+ channels. This is
the first report that cilnidipine at lower concentration of 10(-6) M blocks both
L-and N-type HVA I(Ca) in the hippocampal neurons.
PMID- 10784101
TI - Spermine dependent activation of the N-methyl-D-aspartate receptor and the effect
of nitric oxide synthase inhibition during hypoxia in the cerebral cortex of
newborn piglets.
AB - This study tests the hypothesis that brain tissue hypoxia results in modification
of spermine-dependent activation of the cerebral N-methyl-D-aspartate (NMDA)
receptor ion-channel in newborn piglet brains and that pretreatment with N(omega)
nitro-L-arginine (NNLA), an inhibitor of nitric oxide synthase, will reduce the
hypoxia-induced modification of the spermine-dependent activation of the
receptor. Piglets were assigned to one of four groups; normoxia or hypoxia with
or without NNLA. The infusion of NNLA or vehicle lasted for 60 min while the
animals were ventilated under either hypoxic or normoxic conditions. Cerebral
tissue hypoxia was confirmed by measuring ATP and phosphocreatine (PCr) levels.
P2 membranes were isolated and 3H-MK-801 binding was measured in the presence of
spermine. Steady state 3H-MK-801 binding in the presence of spermine, showed an
increase in receptor affinity in both normoxic (47% of control) and hypoxic (42%
of control) animals without change in receptor density. During hypoxia, the
spermine-dependent increase in the maximal response of the 3H-MK-801 binding
correlated inversely with the ATP concentrations. NNLA pretreatment prior to
hypoxia, resulted in a decrease in the slope of the regression line describing
the relationship between cellular energy state (ATP) and percent change in
maximal response to spermine compared with vehicle treated animals indicating
attenuation of the response to hypoxia. We conclude that the spermine-dependent
modification of the affinity of the NMDA receptor ion-channel as assessed by 3H
MK-801 binding is similar in hypoxic and normoxic cortical tissue. NNLA
administration reduces the hypoxia-induced spermine-dependent activation of the
receptor indicating that nitric oxide mediates modification of the spermine site
activation of the NMDA receptor ion-channel complex.
PMID- 10784102
TI - A possible role for nerve growth factor in the augmentation of sodium channels in
models of chronic pain.
AB - Inflammation induces an upregulation of sodium channels in sensory neurons. This
most likely occurs as a result of the retrograde transport of cytochemical
mediators released during the inflammatory response. The purpose of this study
was to determine the effect of the subcutaneous administration of one such
mediator, nerve growth factor (NGF), on the production of sodium channels in
neurons of the rat dorsal root ganglion. For this, hindpaw withdrawal from either
a thermal or mechanical stimulus was measured in rats at selected intervals for
up to 2 weeks following injections of NGF. Sodium channel augmentation was then
examined in dorsal root ganglia using site-specific, anti-sodium channel
antibodies. Both thermal and mechanical allodynia was observed between 3 and 12 h
post-injection. The hyperalgesic response returned to baseline by approximately
24 h post-injection. Sodium channel labeling was found to increase dramatically
in the small neurons of the associated dorsal root ganglia beginning at 23 h,
reached maximum intensity by 1 week, and persisted for up to 3 months post
injection. Pre-blocking NGF with anti-NGF prevented the NGF-induced decrease in
paw withdrawal latencies and significantly reduced the intensity of sodium
channel labeling. The results indicate that NGF is an important mediator both in
the development of acute hyperalgesia and in the stimulation of sodium channel
production in dorsal root ganglia during inflammation.
PMID- 10784103
TI - Intracisternal PYY inhibits gastric lesions induced by ethanol in rats: role of
PYY-preferring receptors?
AB - We previously reported that intracisternal (i.c.) injection of peptide YY (PYY)
and low doses of thyrotropin-releasing hormone (TRH) or TRH analog, RX 77368,
increased the resistance of the gastric mucosa to ethanol injury through vagal
pathways in rats. The gastroprotective effect of i.c. injection of
PYY/neuropeptide NPY (NPY) agonists with differential in vitro affinity to the Y
receptor subtypes was examined in urethane-anesthetized rats. Intragastric
administration of ethanol (45%, 5 ml/kg) results in mucosal lesions covering 23+/
2% of the gastric corpus in 1 h. PYY (500 ng, i.c.) significantly reduced ethanol
induced gastric lesions by 52%. [Pro34]PYY (PYY-preferring/Y1/Y5/Y4 subtypes)
injected i.c. at 50, 100, 200 or 500 ng, reduced dose dependently gastric lesions
to 15.4+/-2.2%, 11.4+/-3.1%, 8.6+/-2.9% and 5.4+/-2.2%, respectively. PYY3-36,
(Y2/Y4 subtypes), [Leu31, Pro34]NPY (Y1/Y5), NPY (Y3/Y1/Y5/Y2) and pancreatic
polypeptide (PP, Y4) injected i.c. at 500 ng did not influence significantly
ethanol-induced gastric lesions. Combined i.c. injection of RX 77368 (1 ng) and
Pro34PYY (25 ng), at sub-threshold doses given singly, reduced ethanol-induced
gastric injury to 12.9+/-2.3% while RX 77368 (1 ng) plus PYY3-36 (500 ng) or
[Leu31, Pro34]NPY (25 ng) had no effect. These findings indicate that i.c. PYY
induced gastric protection against 45% ethanol is mediated by a Y receptor
subtype which bears similarity with the putative PYY-preferring receptor and
distinct from the currently defined Y1/Y5; in addition, there is a synergistic
interaction between activation of this PYY-preferring receptor and i.c. TRH to
increase the resistance of the gastric mucosa to injury caused by 45% ethanol.
PMID- 10784104
TI - Effects of acute and chronic treatment with fluoxetine on regional glucose
cerebral metabolism in rats: implications for clinical therapies.
AB - The wide therapeutic spectrum of fluoxetine (e.g., antidepressant, antipanic,
antiphobic, antiobsessive, analgesic, antimigraine) requires long-term
administration and adaptive changes. To test whether adaptation involves the
serotonin (5-HT) transporters, we measured the effects of fluoxetine on the
regional cerebral metabolic rate for glucose (rCMRglc) in control rats or in rats
pretreated for 2 weeks with fluoxetine (8 mg/kg, i.p., daily, 2 days wash out);
rCMRglc was measured in 56 brain regions, using the quantitative
[14C]deoxyglucose technique, at 30 min after i.p. administration of fluoxetine
0.4, 4 or 40 mg/kg, i.p., to non-pretreated rats or fluoxetine 4 mg/kg to
pretreated rats. In non-pretreated rats, fluoxetine reduced rCMRglc in a dose
dependent fashion in 4 (7%, mean decrease 11%), 28 (50%, mean decrease 23%) and
37 (66%, mean decrease 32%) brain regions. In chronic fluoxetine-pretreated rats,
fluoxetine decreased rCMRglc to a substantially lesser degree (eight regions,
14%; mean decrease, 10%). Subcortical brain regions (i.e., hypothalamic
paraventricular, locus coeruleus and basal ganglia nuclei) that mediate the
physiological responses to stress were very sensitive to fluoxetine acutely and
subsensitive after chronic treatment. As kinetic tolerance to fluoxetine does not
occur during chronic administration, the diminished rCMRglc responsivity to
fluoxetine reflects dynamic, adaptive tolerance of 5-HT transporters and,
consequently, increased synaptic 5-HT concentrations; the findings suggest that
fluoxetine may be therapeutic by increasing the 5-HT-negative modulation upon
areas that drive the abnormally hyperactive responses to stress found in several
neuropsychiatric conditions.
PMID- 10784105
TI - Role of calcium on the modulation of spontaneous acetylcholine efflux by the D2
dopamine receptor subtype in rat striatal synaptosomes.
AB - The role of calcium in the modulation of spontaneous [3H]acetylcholine ([3H]ACh)
efflux through presynaptic D2 dopamine hetero-receptors was investigated in rat
striatal synaptosomes. The kinetic studies of [3H]ACh efflux in the presence or
absence of Ca2+ were carried out in nonstimulating conditions. When Ca2+ was
omitted from the superfusion medium, a notable and significant (P<0.001) decrease
of tritium efflux (39%) was obtained. While [3H]ACh efflux was insensitive to
tetrodotoxin (TTX) 1 microM, cadmium (10 microM), a nonselective antagonist of
calcium channels, significantly reduced the tritium efflux by 24% (P<0.001),
while the L-type calcium antagonist, nifedipine, (30 microM) inhibited the
tritium efflux by only 10% (P<0.02). 2-(4-Fenylpiperidine)cyclohexanol
(vesamicol), an inhibitor of the vesicular [3H]ACh carrier, significantly
depressed the spontaneous tritium efflux in the presence of Ca2+ (60%; P<0.001)
and in a low-calcium medium (20%; P<0.001). Although 1 microM of 7-hydroxy-N,N-di
n-propyl-2-aminotetraline (7-OH-DPAT) inhibited spontaneous [3H]ACh efflux in the
presence of calcium, this dopaminergic agonist did not modify the
neurotransmitter release in either the low-Ca2+ medium or in the presence of
vesamicol. These results suggest that the spontaneous [3H]ACh efflux is a process
involving a Ca2+-dependent component (39%), sensitive to calcium channel-blockers
and vesamicol, in rat striatal synaptosomes. In addition, activation of the D2
dopamine hetero-receptor only modulates the calcium-dependent component of
spontaneous [3H]ACh efflux.
PMID- 10784106
TI - Simultaneous action of MK-801 (dizclopine) on dopamine, glutamate, aspartate and
GABA release from striatum isolated nerve endings.
AB - The simultaneous effect of MK-801 on the baseline- and depolarization (20 microM
veratridine or 30 mM high K+)-evoked release of endogenous dopamine, glutamate
(Glu), aspartate (Asp), and GABA is investigated in the same preparation of rat
striatum isolated nerve endings. MK-801, in the microM range, selectively
increases the baseline and high K+ depolarization-evoked release of dopamine,
without causing any effect on the baseline or on the high K+-evoked release of
Glu, Asp and GABA. In addition to this selective action on dopamine release, MK
801 inhibits the veratridine depolarization-evoked release of all the
neurotransmitters tested, including dopamine. In SBFI and fura-2 preloaded
striatal synaptosomes, MK-801 inhibits the elevation of internal Na+ (Na(i)) and
the elevation of internal Ca2+ (Ca(i)) induced by veratridine depolarization. The
elevation of Ca(i) induced by high K+ depolarization is unchanged by MK-801. This
study reveals two separate MK-801 actions. (1) The voltage-independent action,
which increases dopamine release selectively, and might contribute to the effects
of MK-801 on motor coordination. (2) The voltage-dependent action, which inhibits
all the veratridine-evoked responses including the evoked release of the
excitatory amino acids (which are particularly concentrated in striatum nerve
endings), and might contribute to the anticonvulsant and neuroprotective effects
of MK-801.
PMID- 10784107
TI - Cellular expression of ionotropic glutamate receptor subunits in subpopulations
of neurons in the rat substantia nigra pars reticulata.
AB - In order to characterize the expression of ionotropic glutamate receptor
immunoreactivity in subpopulations of neurons in the rat substantia nigra pars
reticulata (SNr), double labeling experiments were performed. Neurons in the
reticulata were found to display GluR1, GluR2, GluR2/3, GluR4, N-methyl-D
aspartate receptor 1 (NMDAR1) and NMDAR2B immunoreactivity. Some of the
reticulata neurons were shown to display GluR1 and GluR2 immunoreactivity or
GluR2 and GluR4 immunoreactivity at the single cell level. In addition,
subpopulations of reticulata neurons were characterized on the basis of the
strong expression of parvalbumin (PV) and GABA transaminase immunoreactivity. All
of the reticulata neurons that displayed strong immunoreactivity for PV or GABA
transaminase also displayed immunoreactivity for GluR1, GluR2/3, GluR4, NMDAR1
and NMDAR2B. A tiny portion (around 15%) of reticulata neurons that display
NMDAR1 immunoreactivity was found to be PV- or GABA-transaminase-negative. The
present results indicate that native alpha-amino-3-hydroxy-5-methyl-4-isoxazole
propionate (AMPA)-type receptors and NMDA-type receptors in the rat substantia
nigra are composed of heteromeric receptor subunits. The present findings further
demonstrate that most of the AMPA-type and NMDA-type glutamate receptor subunits
are primarily expressed by subpopulations of neurons in the rat SNr.
PMID- 10784108
TI - Transplantation of olfactory ensheathing cells or Schwann cells restores rapid
and secure conduction across the transected spinal cord.
AB - Olfactory ensheathing cells (OECs) or Schwann cells were transplanted into the
transected dorsal columns of the rat spinal cord to induce axonal regeneration.
Electrophysiological recordings were obtained in an isolated spinal cord
preparation. Without transplantation of cells, no impulse conduction was observed
across the transection site; but following cell transplantation, impulse
conduction was observed for over a centimeter beyond the lesion. Cell labelling
indicated that the regenerated axons were derived from the appropriate neuronal
source, and that donor cells migrated into the denervated host tract. As reported
in previous studies, the number of regenerated axons was limited. Conduction
velocity measurements and morphology indicated that the regenerated axons were
myelinated, but conducted faster and had larger axon areas than normal axons.
These results indicate that the regenerated spinal cord axons induced by cell
transplantation provide a quantitatively limited but rapidly conducting new
pathway across the transection site.
PMID- 10784109
TI - Amylin compared with calcitonin: competitive binding studies in rat brain and
antinociceptive activity.
AB - Binding studies for rat amylin (AMY) and salmon calcitonin (sCT) were performed
on rat membranes prepared from pons and medulla oblongata of rats. The aim was to
see whether specific binding sites for AMY and/or for sCT present in these areas
could be relevant to some of the biological activities of the two peptides.
Binding sites specific for [125I]AMY are present in the pons-medulla of rat brain
as AMY, but not sCT, was able to displace radiolabeled AMY binding with an IC50 =
3.7+/-0.5x10(-10) M. In contrast, binding of [125I]sCT was displaced by both sCT
and AMY, although with different potencies, the IC50 for sCT being 1+/-0.1x10(
11) M, and for AMY, 1.8+/-0.08x10(-7) M. The functional significance of the
presence of these binding sites was evaluated in two different nociceptive tests,
hot-plate and tail-flick. In the tail-flick test neither AMY (5-10 microg/rat,
i.c.v.) nor sCT (10 microg/rat i.c.v.) showed antinociceptive activity, whereas
in the hot-plate test AMY (10 microg/rat, i.c.v.) significantly increased the
response latencies as did sCT (250 ng/rat, i.c.v.). These results demonstrated
that a 40-fold greater dose of AMY is necessary to produce a comparable
antinociceptive effect to that exerted by sCT. These findings are in accordance
with the low affinity of AMY for sCT binding sites in rat pons-medulla. It is
therefore suggested that the central inhibitory activity of AMY on pain
perception involves interaction with sCT receptors whereas the selective AMY
binding sites subserve other (as yet unknown) functions.
PMID- 10784110
TI - Microinjections of an opiate receptor antagonist into the bed nucleus of the
stria terminalis suppress heroin self-administration in dependent rats.
AB - Recent anatomical evidence suggests that the shell of the nucleus accumbens, the
bed nucleus of the stria terminalis, and the central nucleus of the amygdala,
together referred to as the extended amygdala, may play a role in opiate
dependence. The bed nucleus of the stria terminalis and the shell of the nucleus
accumbens have a moderately high density of opiate receptors, which allows for
manipulation of opiate neurotransmission with receptor antagonists. The goal of
this study was to determine the role these regions play in opiate reinforcement,
and whether dependence alters the reinforcing effects of opiates by examining the
effect of local administration of the opiate receptor antagonist methylnaloxonium
on heroin self-administration in dependent and nondependent rats. Previous
studies revealed that blockade of the reinforcing effects of opiates with
systemic administration of opiate receptor antagonists results in an increase in
heroin self-administration in nondependent rats, and a greater increase in
dependent rats. In the present study, methylnaloxonium dose-dependently
suppressed heroin intake when injected into the bed nucleus of the stria
terminalis and shell of the nucleus accumbens of dependent rats, and had no
effect in nondependent rats. These results demonstrate that opiate receptors in
parts of the extended amygdala may be responsible for the reinforcing effects of
opiates in dependent animals and suggest that activity in this system may be
recruited during the development of dependence.
PMID- 10784111
TI - Differential distribution of metabotropic glutamate receptor subtype mRNAs in the
thalamus of the rat.
AB - L-Glutamate (L-Glu) is present in most excitatory synapses of the mammalian
brain, acting on several receptor subtypes. Height different genes encoding
metabotropic glutamate receptors (mGluRs) subtypes have been described (mGluR1
8), having a distinct distribution in the brain. In the present study, the
distribution of mGluR1, 3, 4, 5 and 7 mRNAs was determined in 20 thalamic nuclei
of adult rats by performing in situ hybridisation with subtype-specific 35S
labelled oligonucleotide probes. High expression of mGluR1 mRNA mainly occurred
in midline nuclei such as the centromedial/centrolateral (CM/CL) nuclei,
parafascicular and submedius nuclei, and in the ventroposteromedial (VPM) and
posterior (Po) nuclei. In contrast, mGluR5 mRNA was more uniformly distributed at
weak to moderate levels, except in the reuniens nucleus where a strong signal was
detected. The mGluR3 mRNA was highly expressed in the reticular thalamic nucleus
and almost not detectable in any other thalamic region. Additionally, mGluR3 mRNA
was found not only in neurones but also in putative glial cells. The mGluR4 mRNA
was abundant in most thalamic nuclei, with prominent expression in the CM/CL, Po
and ventrobasal complex (VPM and ventroposterolateral, VPL). Finally, mGluR7
transcripts were found evenly distributed throughout the thalamus at moderate
levels, the highest signal being detected in the paraventricular thalamic
nucleus, VPM, VPL and Po. This differential distribution of mGluR subtypes in the
rat thalamus may contribute to the heterogeneity of glutamate effects on thalamic
neurones. The mGluR1, mGluR4 and mGluR7 receptors may be involved in the
processing of somatosensory information because they are expressed in nuclei that
receive direct sensory input.
PMID- 10784112
TI - Effects of chlorobutanol on primary and secondary endings of isolated cat muscle
spindles.
AB - The effects of the preservative chlorobutanol on primary and secondary endings of
muscle spindles isolated from the tenuissimus muscle of the cat were investigated
in this study. Chlorobutanol was applied to the bathing solution in final
concentrations of between 10 and 100 microg/ml. It induced a reversible and dose
dependent decrease in the discharge frequency of both types of ending without any
visible length change in the sensory region of the receptor. The initial
activity, the peak dynamic discharge, the maximum static discharge value and the
final static discharge value were evaluated from an ending's discharge pattern
obtained during ramp-and-hold stretches. These four basic discharge frequencies
decreased in parallel with increasing concentrations of chlorobutanol. Their
sensitivities to chlorobutanol were similar (mean values: -0.11 to -0.29 imp/s
per microg/ml chlorobutanol) and were independent of the amplitude of stretch.
The dynamic response and the static response of both primary and secondary
endings remained unchanged, indicating that the sensitivity of the spindle to
stretch was not influenced by chlorobutanol. Chlorobutanol also reduced the
discharge activity of the muscle spindle afferents during sinusoidal stretches.
The amplitude of the receptor potential (AC component) remained unchanged under
chlorobutanol. With the available recording technique it was not possible to
measure slow shifts of the membrane potential. However, a hyperpolarization of
the ending's membrane might explain why the afferent discharge frequency is
reduced by chlorobutanol. The calcium dynamics of the spindle do not appear to be
altered by CB, as the effect exerted on the afferent discharge by a change in the
extracellular calcium concentration and a blockage of calcium channels was
different from the CB effect. As the inhibitory effect of CB was reduced by
ouabain, it is possible that CB activates the electrogenic Na/K pump or affects a
mechanism that is closely related to the activity of the pump. The properties of
the axonal membrane appear not to be altered, as chlorobutanol did not change the
shape of action potentials.
PMID- 10784113
TI - Corticotropin releasing hormone neurons in the paraventricular nucleus are direct
targets for neuropeptide Y neurons in the arcuate nucleus: an anterograde tracing
study.
AB - In the present study, anterograde tracing combined with triple label
immunofluorescent staining was conducted to examine the possible anatomical
interactions between Neuropeptide Y (NPY) neurons in the arcuate nucleus of the
hypothalamus (ARH) and the corticotropin releasing hormone (CRH) system in the
paraventricular nucleus of the hypothalamus (PVH). The anterograde tracer,
Phaseolus vulgaris leucoagglutinin (PHA-L), was iontophresed into the ARH of
female rats and triple label immunofluorescence staining with three different
fluorophores was performed to visualize PHA-L, NPY and CRH, with the aid of
confocal microscopy. In PVH, NPY and PHA-L double-labeled fibers were found
mainly in the parvocellular part of the PVH (PVHp). Confocal analysis
demonstrated that NPY/PHA-L double-labeled fibers came in close apposition to CRH
perikarya. In the median eminence, NPY/PHA-L double-labeled fibers were found
both in the inner and the outer zones of the median eminence. However, very few
double-labeled fibers were found in the proximity of CRH neuronal fibers in the
median eminence. Double label staining was also performed to determine if NPY Y1
receptors were expressed in CRH neurons. Two different fluorophores were used to
visualize CRH neurons and Y1 receptor. No convincing Y1-positive staining was
found in CRH cell bodies in the PVH, even though Y1-positive staining in numerous
fibers and cell bodies was observed throughout the region. However, Y1-positive
fibers were shown to make close contact with CRH cell bodies in the PVH. In the
ME, the majority of the Y1-positive fibers were located in the lateral portion of
the ME, whereas the CRH fibers were found mainly in the medial portion of the
external zone of the ME. The results of the present study suggest that ARH NPY
neurons provide direct input into CRH cell bodies in the PVH region. However, the
direct effects of NPY must be mediated by some receptor subtype other than Y1. Y1
receptor involvement in NPY modulation of CRH neuronal function in the PVH
appears to be indirect through modulation of neuronal afferents making contact
with CRH neurons.
PMID- 10784114
TI - Microanatomical localization of dopamine receptor protein immunoreactivity in the
rat cerebellar cortex.
AB - Dopamine (DA) receptor subtype localization was investigated in rat cerebellar
cortex using immunohistochemical techniques with antibodies raised against D1-D5
receptor protein. A faint D1 receptor protein immunoreactivity was developed in
molecular and Purkinje neurons layers. D2 receptor protein immunoreactivity was
found primarily in cerebellar white matter followed by molecular and granular
layers and Purkinje neurons. Antibodies against D2S receptor protein were
localized in molecular layer and to a lesser extent, in granular layer. A few
Purkinje neurons displayed a faint D2S receptor protein immunoreactivity. D3
receptor protein immunoreactivity was observed primarily in molecular and in
Purkinje neurons layers of lobules 9 and 10. A faint D3 receptor protein
immunoreactivity was also localized in Purkinje neurons and to a lesser extent,
in molecular and granular layers of cerebellar lobules 1-8. D4 receptor protein
immunoreactivity was found in cerebellar white matter. A pale immunostaining was
also visualized in molecular layer. D5 receptor protein immunoreactivity was
localized primarily in molecular and Purkinje neurons layers and to a lesser
extent, in granular layer and in white matter. The above results indicate that
rat cerebellar cortex expresses the DA receptor subtypes so far identified.
Purkinje neurons, which are the only efferent neurons of cerebellum, are richest
in DA receptor protein immunoreactivity. This suggests that dopaminergic
neurotransmission may modulate efferent inputs from cerebellum. The localization
of the majority of D2 and D4 and of a faint D5 protein receptor immunoreactivity
in cerebellar white matter suggests that these receptors may be presynaptic and
transported axonally.
PMID- 10784115
TI - Mitochondria buffer non-toxic calcium loads and release calcium through the
mitochondrial permeability transition pore and sodium/calcium exchanger in rat
basal forebrain neurons.
AB - Mitochondria participate in intracellular Ca2+ buffering and signalling. They are
also major mediators of cell death. Toxic Ca2+ accumulation in mitochondria is
widely believed to initiate cell death in many cell types by opening the
permeability transition pore (PTP). In non-neuronal cells, the PTP has been
implicated as a Ca2+ release mechanism in physiological Ca2+ signalling. In
neurons, Ca2+ release from mitochondria has been attributed primarily to
mitochondrial Na+/Ca2+ exchange. Using fura-2 ratiometric microfluorimetry in
acutely dissociated rat basal forebrain neurons, we show that mitochondria are
able to buffer non-toxic Ca2+ loads arising from caffeine-sensitive internal
stores or from extracellular influx through voltage gated channels. We also show
that these non-toxic Ca2+ loads are reversibly released from mitochondria through
the PTP and the Na+/Ca2+ exchanger. Evoked Ca2+ transients have characteristic
peak and shoulder features mediated by mitochondrial buffering and release.
Depolarizing mitochondria with carbonyl cyanide m-chlorophenylhydrazone (CCCP, 5
microM) causes release of mitochondrial Ca2+ and prevents Ca2+ uptake. In CCCP,
the magnitudes of evoked Ca2+ transients are increased, and the peak and shoulder
features are eliminated. The PTP antagonist, cyclosporin A, (CSA, 2 microM) and
the Na+/Ca2+ exchange blocker, clonazepam, (CLO, 20 microM) reversibly inhibited
both the shoulder features of evoked Ca2+ transients and Ca2+ transients
associated with CCCP application. We suggest that central neuronal mitochondria
buffer and release Ca2+ through the PTP and Na+/Ca2+ exchanger during
physiological Ca2+ signalling. We also suggest that CLO blocks both the PTP and
the mitochondrial Na+/Ca2+ exchanger.
PMID- 10784116
TI - Adenosine release upon spinal cord injury.
AB - The hypothesis that release of adenosine following spinal cord injury (SCI) may
provide neuroprotective feedback is explored. Consistent with this hypothesis,
substantial release of adenosine, estimated to reach 100 microM in the
extracellular space, was detected by microdialysis sampling immediately following
contusion SCI. There is also considerable release of excitatory amino acids
following SCI. The latter was not affected by administration of the general
adenosine receptor antagonist theophylline and the A1 antagonist 8-cyclopentyl
1,3-dipropylxanthine, implying that the adenosine released following SCI does not
significantly influence the release of neurotoxic amino acids. Administration of
the concentration of glutamate released upon SCI into the spinal cord caused only
about 1% as much release of adenosine as did injury, evidence that elevated
excitatory amino acids do not elicit an appreciable fraction of the release of
adenosine that follows SCI. Results obtained suggest that release of endogenous
adenosine is not neuroprotective by blocking release of excitatory amino acids
following SCI.
PMID- 10784117
TI - Strain differences to the effects of aversive frequency ultrasound on behaviour
and brain topography of c-fos expression in the rat.
AB - Previous studies have shown that ultrasound at 20 kHz produces an escape
(defence) response in the hooded Lister rat. This study compares the ultrasound
induced behavioural response in the hooded Lister and albino Wistar rat.
Ultrasound (continuous tone, square wave, 20 kHz) produced an initial
characteristic startle response (brisk running) in the hooded Lister rat that was
followed immediately after cessation of the ultrasound by a period of freezing
behaviour. In contrast, Wistar rats showed no initial escape response but a
prolonged period of freezing that started during the ultrasound and continued for
a period after the end of the ultrasound. Immunohistochemical assessment of c-fos
expression also showed a difference between the two strains with preferential
expression in the dorsal region of the rostral and caudal periaqueductal grey
(PAG) in the hooded Lister rat, while the expression occurred in the ventral PAG
in the Wistar rats. In summary, the two strains exhibit distinct defensive
behaviours and patterns of neuronal activation in response to the same aversive
signal. It remains to be determined whether these differences relate to neuronal
circuitry or perception of the signal, but analysis of the mechanisms involved
may help our understanding of the heterogeneity of anxiety disorders.
PMID- 10784118
TI - Enhancement of Ca2+-induced noradrenaline release by vanadate in PC12 cells:
possible involvement of tyrosine phosphorylation.
AB - Tyrosine phosphorylation has been shown to participate in the signal cascade
after receptor stimulation with neurotransmitters and neurotrophins. However, the
role of tyrosine phosphorylation in the process(es) of neurotransmitter release
has not been well established. The effects of orthovanadate (Na3VO4), an
inhibitor of protein-tyrosine phosphatases, on cytosolic free Ca2+ concentrations
([Ca2+]i), phosphotyrosine accumulation and noradrenaline (NA) release in
neurosecretory PC12 cells were investigated. Addition of Na3VO4 enhanced
ionomycin-stimulated [3H]NA release in a concentration-dependent manner, although
Na3VO4 alone had no effect. Na3VO4 also enhanced [3H]NA release induced by P2
receptor stimulation with adenosine 5'-O-(3-thiotriphosphate) (ATPgammaS) or by
depolarization with 50 mM KCl, which stimulated a [Ca2+]i increase. A cell
permeable inhibitor of protein-tyrosine phosphatases, L-p-bromotetramisole
oxalate, at 0.3 mM enhanced ionomycin-stimulated [3H]NA release, although
pervanadate had no effect. Addition of 5 mM Na3VO4 stimulated phosphotyrosine
accumulation in several protein bands such as p130cas, but did not increase
[Ca2+]i in PC12 cells. These findings suggest that the tyrosine phosphorylation
pathway regulates Ca2+-stimulated NA release without changes of [Ca2+]i in PC12
cells.
PMID- 10784119
TI - Activation of cardiac vagal afferents facilitates late vagal inhibition in
neurones of the rostral ventrolateral medulla oblongata bilaterally.
AB - A reduced activity of cardiac vagal afferent fibres is considered as one of the
pathophysiological causes of post-infarction complications [A. Head, Baroreflexes
and cardiovascular regulation in hypertension. J. Cardiovasc. Pharmacol. 26
(1995) S7-S16]. The mechanism of how a reduction of cardiac vagal activity leads
to enhanced sympathetic drive and systemic hypertension is however not yet clear.
Experimental data have shown that the rostral ventrolateral medulla oblongata
(RVLM) plays an important role in tonic blood pressure regulation, the control of
sympathetic vasoconstriction and cardiac performance. The aim of the study was to
determine whether activation of cardiac vagal afferents contributes to eliciting
the long-lasting late inhibition that we have previously shown to occur in
neurones of the RVLM [A. Zagon, K. Ishizuka, I. Rocha, K.M. Spyer, Late vagal
inhibition in neurones of the ventrolateral medulla oblongata in the rat.
Neurosci. 92 (1999) 877-888]. The experiments were carried out in terminally
anaesthetised and artificially ventilated rats using in vivo intracellular
recordings. The data confirmed that late vagal inhibition is elicited by
cumulative activation of functionally different vagal afferents, including those
that originate from cardiac receptors. It was also demonstrated that activation
of cardiac afferents could lead to a significant increase in the duration of this
long-lasting late response component. Facilitation of late vagal inhibition was
observed in RVLM neurones both ipsi- and contralateral to the stimulated nerve.
It is suggested that such facilitation of late vagal inhibition may be a
mechanism of how pulse-synchronous activation of cardiac afferents leads to a
tonic modulation of the activity of RVLM neurones. An attenuation of late vagal
inhibition during reduced activity of cardiac vagal afferents could lead to
enhanced excitability in these neurones which in turn can lead to an increase in
medullary sympathetic outflows towards the heart and peripheral blood vessels.
PMID- 10784120
TI - Mononuclear cell proliferation and hyperplasia during Wallerian degeneration in
the visual system of the goldfish in the presence or absence of regenerating
optic axons.
AB - Patterns of proliferation and changes in non-neuronal cell number in the visual
system of the goldfish have been quantitatively examined during optic axon
regeneration after an optic nerve crush (ONC). In addition, in order to examine
the effect of the regenerating axons on cellular responses in the visual
pathways, we did a similar analysis of animals with the right eye removed (ER).
Finally, we used double labeling protocols to demonstrate that the proliferating
cells that we were counting were mostly phagocytic cells of the mononuclear
lineage. In animals with an ONC, we observed an early burst of proliferation that
peaked between 7 and 14 days after surgery in all parts of the visual system. In
the optic tract, there was also a secondary rise that peaked at 21 days. Levels
of proliferation returned to normal by 32 days postoperative in the tract and
tectum, while they remained somewhat elevated in the optic nerve for at least 93
days. The total number of non-neuronal cells in the visual paths also rose to
peak values between 7 and 14 days after ONC surgery. In the optic tract and
tectum, the values fell rapidly after this time, while in the optic nerve, there
was a secondary peak at 32 days after which values remained elevated for the
duration of the experiment. As compared to animals with an ONC, enucleation
resulted in elevated proliferation and hyperplasia at early postoperative
intervals. However, because these differences occurred when axons had not yet
regenerated into the affected structures, these data do not provide strong
evidence for a direct effect of regenerating optic axons on the early cellular
responses during Wallerian degeneration in the goldfish. In addition, in the
tectum, there was an early increment in cell number that was not associated with
elevated levels of proliferation. We believe that this increment represents
immigration of resident microglia from other regions of the brain.
PMID- 10784121
TI - Expression of Fos protein in adrenal preganglionic neurons following chemical
stimulation of the rostral ventrolateral medulla of the rat.
AB - The ventrolateral medulla is known to be involved in the regulation of arterial
blood pressure, especially via its connections with sympathetic preganglionic
neurons (SPNs) mainly located in the intermediolateral nucleus of the spinal
cord. It has been shown that stimulation of the rostral part of the ventrolateral
medulla (RVLM) elicits a release of catecholamines from the adrenal medulla. The
aim of the present study was to demonstrate the existence of a functional pathway
between the RVLM and adrenal SPNs using the combination of a retrograde tract
tracing technique (cholera toxin B subunit) with the immunohistochemical
detection of Fos protein following the chemical stimulation of RVLM. The data
obtained showed that: (1) chemical stimulation of the RVLM induced Fos
immunoreactivity in the intermediolateral nucleus and particularly in SPNs
projecting to the adrenal medulla; (2) along the thoracic segments T2-T12, 26.1%
of retrogradely identified adrenal SPNs were Fos-immunoreactive with the greatest
percentage (30.9%) in the T8 segment. These results favored a functional control
of the RVLM on adrenal SPNs which may contribute to a substantial activation of
the cardiovascular system via the release of adrenal catecholamines.
PMID- 10784122
TI - Phorbol ester induced changes in tight and adherens junctions in the choroid
plexus epithelium and in the ependyma.
AB - The molecular composition and functional properties of cell-cell junctions of
choroid plexus epithelial cells and the ependyma of the lateral ventricular wall
were investigated in the rat brain. Expression studies of cadherin and alpha- and
beta-catenins, as well as expression of occludin and ZO-1, indicated that cell
adherens and tight junctions were present in both choroid plexus epithelial cells
and in ependymal cells. We then tested the hypothesis that phorbolester in vivo
can induce changes in the expression level of adherens and tight junction
molecules at the blood-cerebrospinal fluid (CSF) barrier as well as in the
ependyma. In addition, the functional properties of the ependymal junctions were
tested by injection of dextran 3000 into the striatum after phorbolester
application. Twenty-four hours after phorbolester-injection into the lateral
ventricle of the rat brain, the expression patterns of tight and adherens
junction molecules were markedly changed in the epithelial cells of the choroid
plexus. The adherens junction proteins cadherin and beta-catenin were reduced in
both the ependymal cells of the lateral ventricle and choroid plexus epithelial
cells. In addition, the occludin-immunoreactivity of the choroid plexus
epithelial cells was strongly reduced. However, the ZO-1 immunoreactivity was not
affected by the phorbol ester-treatment and the alpha-catenin immunoreactivity
was not changed. Furthermore, phorbol ester injection induced a reduction of the
volume of intrastriatal injected biotinylated dextran (m.w. 3000), which is
consistent with a modulatory influence of protein kinase C activation on the
clearance capacity of the brain.
PMID- 10784123
TI - Non-N-methyl-D-aspartate glutamate receptors mediate oxygen--glucose deprivation
induced oligodendroglial injury.
AB - Cells of oligodendroglial lineage are susceptible to oxygen and glucose
deprivation. When oligodendrocyte-like cells differentiated from CG-4
immortalized rat O-2A progenitor cells were exposed to hypoxia alone or glucose
deprivation alone for 48 h, release of lactate dehydrogenase (LDH) into the
culture medium did not increase. However, when cells were deprived of both oxygen
and glucose for 6 or 12 h preceding reoxygenation for 2 h, LDH release increased.
Adding glucose to the medium protected against cell death and increased lactate
production in a concentration-dependent manner. Cell damage induced by
deprivation of oxygen and glucose was prevented by calcium-free medium or by non
N-methyl-D-aspartate glutamate receptor (GluR) antagonists, such as 6-cyano-7
nitroquinoxaline-2,3-dione or LY293558, but not by the voltage-dependent calcium
channel blocker, nimodipine, or by the N-methyl-D-aspartate GluR antagonist, MK
801. The glutamate concentration in the medium from cells exposed to oxygen
glucose deprivation for 12 h was 49.70+/-3.04 microM/l, which is sufficient to
activate GluRs during deprivation of oxygen and glucose. Apoptotic cells detected
by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end
labeling (TUNEL) or Hoechst 33258 staining did not increase in cells exposed to
oxygen-glucose deprivation for 12 h and subsequent reoxygenation for 2 h. No DNA
laddering was detected by agarose gel electrophoresis from cells exposed to
deprivation of oxygen and glucose. Neither acetyl-YVAD-CHO, an inhibitor of
caspase-1-like proteases, nor acetyl-DEVD-CHO, an inhibitor of caspase-3-like
proteases, prevented oxygen-glucose deprivation-induced injury. Thus, oxygen and
glucose deprivation causes calcium-influx-induced necrotic cell damage in cells
of oligodendroglial lineage via non-N-methyl-D-aspartate GluR channels.
PMID- 10784124
TI - Calretinin is not a marker for subdivisions within the suprachiasmatic nucleus.
AB - In this study, we report the immunocytochemical localization of the calcium
binding protein calretinin (CAL) in the suprachiasmatic nuclei (SCN) of male and
female rodents including rats, mice, golden hamsters, and Arvicanthis niloticus.
The results revealed that CAL is present in different subdivisions of the SCN in
the different species studied and CAL can, therefore, not be considered a marker
for particular subdivisions within the SCN. No differences were found between
males and females.
PMID- 10784125
TI - Direct projections from the magnocellular division of the basal nucleus of the
amygdala to the principal part of the cortical masticatory area in the macaque
monkey.
AB - Direct projections from the amygdala to the cortical masticatory area were found
in the macaque monkey. Under the guidance of intracortical microstimulation,
retrograde tracers were injected into multiple jaw movement-related regions of
the frontal lobe. The cortical masticatory area, especially its principal part,
stimulation of which elicited rhythmic jaw movement, was the only site of
injection that produced neuronal labeling in the amygdala. The cells of origin of
such projections were localized in the medial aspect of the magnocellular
division of the basal nucleus through its rostral level. No labeled neurons were
observed in the amygdala after tracer injection into any other cortical jaw
movement-related region. The present results suggest that the amygdaloid input to
the cortical masticatory area may exert some modulatory influence on the
generation of masticatory rhythm.
PMID- 10784126
TI - A novel effect of an opioid receptor antagonist, naloxone, on the production of
reactive oxygen species by microglia: a study by electron paramagnetic resonance
spectroscopy.
AB - Microglia as the first line of defensive cells in the brain produce free radicals
including superoxide and nitric oxide (NO), contributing to neurodegeneration. An
opioid receptor antagonist, naloxone, has been considered pharmacologically
beneficial to endotoxin shock, experimental cerebral ischemia, and spinal cord
injury. However, the mechanisms underlying these beneficial effects of naloxone
are still not clear. This study explores the effects of naloxone on the
production of superoxide and NO by the murine microglial cell line, BV2,
stimulated with lipopolysaccharide (LPS) as measured by electron paramagnetic
resonance (EPR). The production of superoxide triggered by phobol-12-myristate-13
acetate (PMA) resulted in superoxide dismutase (SOD)-inhibitable, catalase
uninhibitable 5,5-dimethyl-1-pyrroline N-oxide (DMPO) hydroxyl radical adduct
formation. LPS enhanced the production of superoxide and triggered the formation
of non-heme iron-nitrosyl complex. Cells pre-treated with naloxone showed
significant reduction of superoxide production by 35%. However, it could not
significantly reduce the formation of non-heme iron-nitrosyl complex and nitrite.
Taken together, the results expand our understanding of the neuroprotective
effects of naloxone as it decreases superoxide production by microglia.
PMID- 10784127
TI - Field responses to perforant path stimulation in the rat dentate gyrus: role of
corticosterone and NMDA-receptor activation.
AB - Recent studies showed that corticosterone and NMDA receptor activation suppress
cell turn-over in the dentate gyrus through a common pathway, the NMDA receptor
acting downstream of the corticosteroids. The present data show that in the
absence of corticosteroids but not of NMDA receptor activation synaptic responses
of dentate cells are reduced. The reduced synaptic responsiveness in the absence
of corticosterone is therefore probably not caused by changes in cell turn-over.
PMID- 10784128
TI - The possible role of endogenous glutathione as an anticonvulsant in mice.
AB - We have recently found that intracerebroventricular (i.c.v.) administration of
glutathione (GSH) inhibits pentylenetetrazol-induced convulsions in mice,
suggesting that GSH has an anticonvulsive action. In the present study, we
investigated whether endogenous GSH play a role in regulating seizure
susceptibility, using L-buthionine-[S,R]-sulfoximine (BSO), a specific inhibitor
of GSH biosynthesis. BSO treatment (3.2 micromol i.c.v. x 2, 48 and 24 h prior to
experiments) decreased brain GSH level to 31.5% of control, and potentiated
pentylenetetrazol-induced convulsions. Potentiation of convulsions by BSO
treatment was recovered by supplying GSH (10 nmol, i.c.v.). These results suggest
that endogenous GSH functions as an anticonvulsant.
PMID- 10784129
TI - Region-specific changes of NOS-IR cells in the basal ganglia of the aged rat.
AB - Nitric oxide (NO) is a free radical postulated to act as a neurotransmitter,
neuromodulator, or second messenger molecule in the central nervous system.
Several findings suggest that NO production may be decreased in the aged rats. In
the present study, we investigated regional discrepancies in changes with aging
in the number of nitric oxide synthase-immunoreactive (NOS-IR) cells in the basal
ganglia of the aged rat by immunocytochemistry. The number of NOS-IR neurons in
the striatum and substantia innominata of the aged rat decreased. In contrast,
the number of NOS-IR neurons in the subthalamic nucleus increased in the aged
rat. On the other hand, the number of NOS-IR neurons in the nucleus accumbens and
olfactory tubercle did not change. Taken together, important functional changes
can be caused by the region-specific changes of NOS-IR neurons in the basal
ganglia with aging.
PMID- 10784130
TI - Hemorrhagic transformation after fibrinolytic therapy with tissue plasminogen
activator in a rat thromboembolic model of stroke.
AB - In this study, the effects of early vs. delayed tPA treatment on the development
of hemorrhagic transformation was compared in a rat thromboembolic model of
stroke. Fibrinolysis was performed by administering tPA intravenously at 2 or 6 h
after ischemic onset. Twenty-four hours later, confluent hemorrhagic infarction
was observed only in rats treated with tPA at 6 h at the rate of 50%. In this
delayed treatment group, significantly increased numbers of polymorphonuclear
leukocytes (PMNL) were observed to accumulate inside microvessels within the
ischemic core. PMNL accumulation may be related to the induction of hemorrhagic
infarction after delayed tPA treatment.
PMID- 10784131
TI - The antinociceptive effect of PAG-microinjected dipyrone in rats is mediated by
endogenous opioids of the rostral ventromedical medulla.
AB - Microinjection of non-opioid analgesics, such as dipyrone (DIP), into the
periaqueductal gray matter (PAG) in rats causes an inhibition of nociceptive
circuits in the spinal cord. We have herein investigated whether this effect is
mediated by opioidergic mechanisms in the rostral ventromedial medulla (RVM),
which is an important relay between the PAG and the spinal cord. The responses of
spinal wide-dynamic-range neurons to noxious stimulation of their receptive field
(RF) were inhibited by microinjection of DIP (100 microg/0.5 microl) into PAG.
Subsequent microinjection of naloxone (NAL; 0.5 microg/0.5 microl) into RVM
reversed this inhibition. The present and previous results suggest that non
opioid analgesics, as well as opiates, inhibit nociception by activating
descending opioidergic mechanisms in PAG and RVM.
PMID- 10784132
TI - Learning-specific decrease in synaptosomal ATP diphosphohydrolase activity from
hippocampus and entorhinal cortex of adult rats.
AB - Considering the involvement of extracellular ATP in the memory formation, we
analyzed the effect of inhibitory avoidance training on ectonucleotidase
activities in synaptosomes from hippocampus, entorhinal cortex and parietal
cortex. ATP diphosphohydrolase activity presented a decrease (33%) in hippocampal
synaptosomes of rats sacrificed 180 min after training. Our results also showed a
decrease in synaptosomal ATP diphosphohydrolase (30% and 42% for ATP and ADP,
respectively) in entorhinal cortex immediately after training. These findings
suggest an integrated action of ATP diphosphohydrolase from hippocampus and
entorhinal cortex in the formation of inhibitory avoidance memory.
PMID- 10784133
TI - Vasoactive intestinal peptide (VIP) prevents neurotoxicity in neuronal cultures:
relevance to neuroprotection in Parkinson's disease.
AB - Vasoactive intestinal peptide (VIP) provides neuroprotection against beta-amyloid
toxicity in models of Alzheimer's disease. A superactive analogue, stearyl-Nle17
VIP (SNV) is a 100-fold more potent than VIP. In primary neuronal cultures, VIP
protective activity may be mediated by femtomolar-acting glial proteins such as
activity-dependent neurotrophic factor (ADNF), activity-dependent neuroprotective
protein (ADNP), peptide derivatives ADNF-9 (9aa) and NAP (8aa), respectively. It
has been hypothesized that beta-amyloid induces oxidative stress leading to
neuronal cell death. Similarly, dopamine and its oxidation products were
suggested to trigger dopaminergic nigral cell death in Parkinson's disease. We
now examined the possible protective effects of VIP against toxicity of dopamine,
6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpyridinium ion (MPP+) in neuronal
cultures [rat pheochromocytoma (PC12), human neuroblastoma (SH-SY5Y) and rat
cerebellar granular cells]. Remarkably low concentrations of VIP (10(-16)-10(-8)
M), ADNF-9 and NAP (10(-18)-10(-10) M) protected against dopamine and 6-OHDA
toxicity in PC12 and neuroblastoma cells. VIP (10(-11)-10(-9) M) and SNV (10(-13)
10(-11) M), protected cerebellar granule neurons against 6-OHDA. In contrast, VIP
did not rescue neurons from death associated with MPP+. Since dopamine toxicity
is linked to the red/ ox state of the cellular glutathione, we investigated
neuroprotection in cells depleted of reduced glutathione (GSH). Buthionine
sulfoximine (BSO), a selective inhibitor of glutathione synthesis, caused a
marked reduction in GSH in neuroblastoma cells and their viability decreased by
70-90%. VIP, SNV or NAP (over a wide concentration range) provided significant
neuroprotection against BSO toxicity. These results show that the mechanism of
neuroprotection by VIP/SNV/NAP may be mediated through raising cellular
resistance against oxidative stress. Our data suggest these compounds as
potential lead compounds for protective therapies against Parkinson's disease.
PMID- 10784134
TI - Velocity-difference induced focusing of nucleotides in capillary electrophoresis
with a dynamic pH junction.
AB - Velocity-difference induced focusing (V-DIF) of nucleotides was achieved by using
a dynamic pH junction in capillary electrophoresis (CE) with UV detection. The
influence of specific analyte properties, such as nucleotide base structure,
sugar structure, and degree of phosphorylation, is examined. The pKa values and
borate complexation with vicinal diols are important factors that caused the
focusing. Therefore, the pH and borate content in the sample and background
electrolyte can be adjusted to optimize the focusing effect. This method allows
the injection of large volumes of sample (approximately 300 nL), resulting in at
least 50-fold improvement in concentration sensitivity. The detection limit of
4.0 x 10(-8) M for nucleotides can be achieved in favorable conditions. V-DIF can
be also applied to nucleotide pool analysis from cell extracts to improve the
concentration sensitivity of CE and to reduce the time-consuming steps of
desalting and off-line preconcentration that are often required for assays of
nucleotides from biological samples.
PMID- 10784135
TI - Chiral separations of polar compounds by hydrophilic interaction chromatography
with evaporative light scattering detection.
AB - The chiral separations of drug substances and underivatized amino acids were
demonstrated in this study through the use of hydrophilic interaction
chromatography (HILIC). The polar character of the model compounds presented
challenges for their analysis by traditional modes of chromatography, but through
the employment of multimodal chromatography utilizing the HILIC mechanism and
cyclodextrin- or teicoplanin-derivatized stationary phases, effective resolution
was achieved. The analytes lacked sufficient ultraviolet chromophores, requiring
their determination by evaporative light scattering detection. HILIC was
demonstrated to represent a novel technique for the facilitation of chiral
chromatography by providing an environment of solubility and retention that could
not be achieved through the use of the traditional methods of reversed-phase,
normal-phase, or polar organic mode.
PMID- 10784136
TI - Examination of structural changes of polymeric amino acid-based surfactants on
enantioselectivity: effect of amino acid order, steric factors, and number and
position of chiral centers.
AB - In this study, a large number of polymeric chiral surfactants were examined and
their performances in terms of enantiomeric resolution compared for a variety of
chiral analytes. The surfactants investigated in this study include all possible
dipeptide combinations of the L-form of alanine, valine, leucine, and the achiral
amino acid glycine (except glycine-glycine). Also included in this study were the
single amino acid surfactants of alanine, valine, and leucine as well as the
single chiral center dipeptide surfactant poly(sodium undecyl-L-leucine-beta
alanine) (poly L-SULbetaA). Several different aspects of polymeric dipeptide
surfactants, as they pertain to chiral separations, are examined. Some of the
factors investigated in this report include the effect of position and number of
chiral centers, amino acid order, and steric effects.
PMID- 10784137
TI - Analytical reliability of mobile-phase recycling in liquid chromatography
AB - Although it is not officially condoned, mobile-phase (MP) recycling has become a
widespread practice that is not well documented in terms of its effects on sample
quantification. MP was spiked with three different concentrations of two
analytes, tartaric acid and sodium citrate, to simulate MP recycling. These MPs
were used to analyze eight different concentrations of these analytes in standard
solutions. When analyte concentration in the MP exceeds that in the sample, a
vacancy (negative) peak is observed, and when its concentration in the MP is
equal to that in the sample, no peak is observed for that analyte. The slopes of
the linear regression lines for standards in MPs with different concentrations of
analyte did not change, although the gamma-intercept values decrease with
increasing concentration of analyte in the MP. These results show that the
concentration of analytes in recycled MP can be determined by comparing the
absolute value of the gamma-intercept of the linear regression line with the
corresponding peak area from the linear regression line for clean (solute-free)
MP, provided other chromatographic parameters do not change. Suggestions are made
for determining when recycled MP should be discarded.
PMID- 10784138
TI - Element-specific detection in capillary electrophoresis using X-ray fluorescence
spectroscopy.
AB - X-ray fluorescence spectroscopy is demonstrated here as a novel, element-specific
detector for capillary electrophoresis. Monochromatic 10 keV X-rays from a
synchrotron light source are used to excite core electrons, causing emission of
characteristic Kalpha X-ray fluorescence (XRF) lines. Using this technique, XRF
energies provide elemental identification, while XRF intensities can be used to
quantitate the metal composition of each eluent. An X-ray transparent polymer
coupling is used to create a window for the on-line, X-ray detection. This
coupling contributes no measurable extra-column variance, and electrophoretic
mobilities for the metal complexes used as model solutes are highly reproducible.
The combination of XRF detection with capillary electrophoresis (CE-XRF) creates
the first on-line detection system that is element-specific, nondestructive, and
directly applicable to a broad range of applications including nonelectroactive
species. CE-XRF is successfully demonstrated here for high binding-constant
complexes of Fe(III), Co(II), Cu(II), and Zn(II). Within a single injection,
electropherograms are obtained for each element of interest, with the element
identity obtained directly from the emission energy. In contrast with ICPMS, this
detection technique is directly on-line and does not require volatilization of
the eluent. As a result, element-specific detection is not limited by the sample
or the buffer volatility or atomization efficiency. Simultaneous XRF and UV
absorbance detection can be used to provide an on-line determination of
metal/chelate ratios. Although XRF detection limits are presently only in the 0.1
mM (0.5 ng) range, both collection geometry and incident intensity have yet to be
optimized. Further optimization is expected to enhance this detection limit by
another 2-3 orders of magnitude. As a result, the advent of XRF detection
combined with the separating power of CE presents new possibilities for on-line,
element-specific analysis.
PMID- 10784139
TI - Enhancement of fluorescence in thin-layer chromatography induced by the
interaction between n-alkanes and an organic cation
AB - Fluorescence enhancement of a broad variety of solutes has been used extensively
in TLC although no thorough explanation has been proposed. In this work, we try
to understand it and explore new applications to which it can be put. In this
way, alkanes can be quantitatively determined by fluorescence scanning
densitometry using silica gel plates impregnated with berberine sulfate.
Molecular simulation and analysis of molecular orbitals allows this phenomenon to
be explained in this case and lays the groundwork to explain fluorescence
enhancements produced by other molecules. A ion-molecule interaction between
alkanes and berberine sulfate is responsible for the enhancement of fluorescence
produced by alkanes. Computational results suggest that the surrounding alkane
molecules provide an apolar environment to the berberine cation, thus enhancing
the intensity of the fluorescence signal. This proposed explanation has been
tested by extending the fluorescence determination to other compounds. These
include biologically interesting saturated and unsaturated fatty acids, steroids
and derivatives, prostaglandins, ceramides, galactocerebrosides, as well as
terpenes, and polypropylene glycols. In addition, according to the proposed
explanation, the properties required for alternative impregnants to berberine are
discussed.
PMID- 10784140
TI - Role of the carbohydrate moieties in chiral recognition on teicoplanin-based LC
stationary phases.
AB - For this study, we used the macrocyclic antibiotic teicoplanin, a molecule
consisting of an aglycone peptide "basket" with three attached carbohydrate
(sugar) moieties. The sugar units were removed and the aglycone was purified. Two
chiral stationary phases (CSPs) were prepared in a similar way, one with the
native teicoplanin molecule and the other with the aglycone. Twenty-six compounds
were evaluated on the two CSPs with seven RPLC mobile phases and two polar
organic mobile phases. The compounds were 13 amino acids or structurally related
compounds (including DOPA, folinic acid, etc.) and 13 other compounds (such as
carnitine, bromacil, etc.). The chromatographic results are given as the
retention, selectivity, and resolution factors along with the peak efficiency and
the enantioselective free energy difference corresponding to the separation of
the two enantiomers. The polarities of the two CSPs are similar. It is clearly
established that the aglycone is responsible for the enantioseparation of amino
acids. The difference in enantioselective free energy between the aglycone CSP
and the teicoplanin CSP was between 0.3 and 1 kcal/mol for amino acid
enantioseparations. This produced resolution factors 2-5 times higher with the
aglycone CSP. Four non amino acid compounds were separated only on the
teicoplanin CSP. Six and five compounds were better separated on the teicoplanin
and aglycone CSPs, respectively. Although the sugar units decrease the resolution
of alpha-amino acid enantiomers, they can contribute significantly to the
resolution of a number of non amino acid enantiomeric pairs.
PMID- 10784141
TI - A high-throughput screening method for the determination of aqueous drug
solubility using laser nephelometry in microtiter plates.
AB - The determination of aqueous solubility in a high-throughput screening
environment is invaluable in the selection of the most promising potential drug
candidates. We describe a fast method based on laser nephelometry that can
determine the solubility of potential drug candidates (usually from combinatorial
chemistry) supplied as dimethyl sulfoxide (DMSO) solutions in 96-well plates. In
the sample, the percent DMSO is kept constant allowing direct comparison of
results. The nephelometric method has been shown to produce results equivalent to
those produced by an HPLC method and to be largely unaffected by colored
solutions.
PMID- 10784142
TI - Speciation of alkyllead and inorganic lead by derivatization with deuterium
labeled sodium tetraethylborate and SPME-GC/MS.
AB - A method for full speciation and determination of alkyllead and inorganic
lead(II) in aqueous samples was developed. This was accomplished by in situ
derivatization with deuterium-labeled sodium tetraethylborate NaB(C2D5)4 (DSTEB).
The derivatization was carried out directly in the aqueous sample and the
derivatives were extracted from the headspace by a solid-phase microextraction
(SPME) fiber. The extracted analytes were then transferred to a GC/MS or a GC/FID
for separation and detection. The research presented demonstrates that SPME and
the derivatization reagent DSTEB can be used successfully for the speciation of
Pb2+, Pb(CH3)3+, Pb(C2H5)3+, and Pb(C2H5)4 in water samples. All derivatives,
Pb(C2D5)4, (CH3)3Pb(C2D5), (C2H5)3Pb(C2D5), and Pb(C2H5)4, are separated using an
SBP-5 column. This method was applied to monitor degradation of tetraethyllead in
water. This is the first report of ethylation by DSTEB for full speciation of
methyllead, ethyllead, and inorganic lead compounds. This approach can be
extended to other organometallic compounds as demonstrated for ethyltin
speciation. This full speciation method will aid in monitoring occurrence,
pathways, toxicity, and biological effects of these compounds in the environment.
It is easily adopted for field analysis.
PMID- 10784143
TI - Application of directly coupled HPLC-NMR-MS to the identification and
confirmation of quercetin glycosides and phloretin glycosides in apple peel.
AB - Directly coupled HPLC-NMR-MS was used to identify and confirm the presence of
quercetin O-glycosides and phloretin O-glycosides in an extract of apple peel.
From the MS and MS/MS data, the molecular weights of the intact molecules as well
as those of quercetin and phloretin and their sugar moieties were deduced. The
NMR data provided information on the identity of the compounds as well as the
alpha and beta conformations and the position of the glycosides on quercetin and
phloretin. The following O-glycosides of quercetin could be identified: quercetin
3-alpha-L-rhamnosyl-(1-->6)-beta-D-glucoside (rutin), quercetin-3-beta-D
galactoside (hyperin), quercetin-3-beta-D-glucoside (isoquercitrin), quercetin-3
beta-D-xyloside (reynoutrin), quercetin-3-alpha-L-arabinofuranoside (avicularin),
and quercetin-3-alpha-L-rhamnoside (quercitrin). Phloretin was present as
phloretin-2'-beta-D-glucoside (phloridzin) and the 2'-beta-D-xylosyl-(1-->6)-beta
D-glucoside. Concentrations were between 0.2 and 5 mg/g of apple peel.
PMID- 10784144
TI - AMACE1: versatile aminoacetamide electrophore reagent.
AB - Acetamide, 2-amino-N-[[3,5-bis(trifluoromethyl)phenyl]-methyl]-N-methyl-,
monohydrochloride, which we have named AMACE1, was synthesized in three steps
starting from N-tritylglycine. AMACE1 was coupled via its primary amine group
(pKa 8.2) under aqueous conditions to four model analytes for oxidative sugar
damage to DNA: glycolate, 3-hydroxy-2-butanone, 3-phenylbutyraldehyde, and alpha
hydroxy-gamma-butyrolactone, relying on cyanoborohydride for coupling to a keto
function and a water-soluble carbodiimide for coupling to a carboxyl function.
Further reaction with butyric anhydride led to products that could be detected by
gas chromatography/electron capture mass spectrometry when 1 microL of ethyl
acetate containing essentially 20 amol of each product was injected, on the basis
of selected ion monitoring of the analyte characteristic anion fragment from
dissociative loss of the 3,5-bis-(trifluoromethyl)phenylmethyl moiety: m/z 215,
289, 299, and 329, respectively. Since many small, organic analytes contain a
keto or carboxylic acid group, AMACE1 should be useful in general in the area of
trace organic analysis.
PMID- 10784145
TI - Retention of ionizable compounds on HPLC. 4. Mobile-phase pH measurement in
methanol/water
AB - The different procedures used in HPLC to measure the pH of a mobile phase are
evaluated in terms of the rigorous IUPAC definition of pH. The three procedures
evaluated are as follows: measurement of the pH of the aqueous HPLC buffer before
mixing it with the organic modifier, measurement of the pH of the HPLC buffer
after mixing it with the organic modifier using a pH electrode system calibrated
with aqueous buffers, and measurement of the pH of the HPLC buffer after mixing
it with the organic modifier but calibrating the electrode system with reference
buffers prepared in the same mixed solvent used as mobile phase. Following IUPAC
definitions and recommendations, the three pH values can be related with the pH
scales: w(w)pH, s(w)pH, and s(s)pH, respectively. The relationships between these
three pH scales are also presented. The retention of several compounds with
acid/base behavior in a C-18 and a polymeric column with buffered methanol/water
as mobile phase is related to the mobile phase pH value measured in the three pH
scales. It is demonstrated that the s(w)pH and s(s)pH scales give better
relationships than the w(w)pH scale (pH measured in the aqueous buffer before
mixing it with the organic modifier), commonly used on HPLC. The s(w)pH scale is
specially recommended because of its simplicity of measurement: the pH is
measured after mixing the aqueous buffer with the organic modifier, but the pH
calibration is performed with the common aqueous reference buffers.
PMID- 10784146
TI - Atrazine-selective polymers prepared by molecular imprinting of trialkylmelamines
as dummy template species of atrazine
AB - Synthetic polymer receptors selective for atrazine have been prepared by
molecular imprinting using trialkylmelamines as template molecules in place of
atrazine. Trialkylmelamines were shown to be useful as templates for introducing
affinity for atrazine into ethylene glycol dimethacrylate-methacrylic acid
copolymers. The polymers showed the selective binding capacity for triazine
herbicides including atrazine, whereas agrochemicals in other categories were not
adsorbed to the imprinted polymers. The group selectivity demonstrated was
comparable with that of the original atrazine imprinted polymers. Use of the
nonagrochemical template molecules as a substitution to atrazine has made it
possible to synthesize herbicide-receptor polymers free from troubles caused by
analyte contaminants, which are desired for analytical applications.
PMID- 10784147
TI - A reversed-phase high-performance liquid chromatographic method for the
determination of soya bean proteins in bovine milks.
AB - A reversed-phase high-performance liquid chromatographic method was designed for
the quantitation of soya bean proteins in bovine milks. The method consisted of a
linear binary gradient, acetonitrile-water-0.1% trifluoroacetic acid, at a flow
rate of 1 mL/min and a temperature of 50 degrees C which resulted in a separation
time for soya bean proteins of 11 min. Calibration by the external standard
method using a soya bean protein isolate as standard was employed, and the method
was validated by evaluating precision, accuracy, and robustness. This method was
shown to be useful for the analysis of soya bean proteins in bovine milks spiked
with soya bean protein isolate; soya bean protein concentrations of approximately
13 microg/g of bovine milk could be detected by using the optimized method. The
results obtained for some of the bovine milks were compared with those obtained
by the method of standard additions.
PMID- 10784148
TI - Improving the recovery of ionic solutes from aqueous media by modified
thermospray liquid-liquid extraction
AB - Our previously reported procedure for the extraction of charged compounds from
aqueous samples by thermospray liquid-liquid extraction (TSLLE) was essentially a
one-step extraction involving large sample volumes. In this report, recirculative
extraction, analysis of small sample volumes, the halide ion effect, and the
effect of solvency or solvent modification on the extraction efficiency of
benzoic acid (BA) by TSLLE were investigated. Compared to the one-step procedure
that resulted in an extraction efficiency of only 28% for BA in n-hexane,
recirculative TSLLE resulted in a BA recovery of 65% after five extraction
cycles. When applied to sample volumes of 5-10 mL, TSLLE extracted BAwith a
precision of 2.8-6.1%. NaF, NaCl, and NaBr were also used to enhance analyte
recovery. NaF gave the best recovery, 104%, for BA relative to the 88% obtained
by batch processing. Some improvements in the extraction efficiency was observed
when solvent modifiers such as methanol, ethanol, and 2-propanol were used.
PMID- 10784149
TI - Development of electrical field-flow fractionation
AB - Electrical field-flow fractionation (ElFFF) results for a series of polystyrene
latex beads are presented. To first approximation, retention behavior can be
related to conventional FFF theory, modified to account for a particle-wall
repulsion effect. Size selectivity and column efficiency were exceptionally high,
again approaching the upper limit predicted by theory. For the channel described
in the present study, application of small voltages (typically less than 2 V)
across the thin (131 microm) separation space defined by a Teflon spacer
generates nominal field strengths of 10(4) V m(-1). However, electrode
polarization reduces the effective field across the bulk of the channel to
approximately 3% of the nominal value in the system studied. The magnitude of the
applied field was calibrated by using standard latex beads of known size and
mobility. Perturbations to retention behavior, such as overloading, were
investigated. It was found that ideal separations occur at very dilute
concentrations of the sample plug and that working in systems of very low ionic
strength, the double-layer thickness adds significantly to the effective size of
a particle. Steric inversion was observed at a particle size of approximately 0.4
microm under the conditions employed.
PMID- 10784150
TI - Laser-activated voltammetry: measurement of the diffusion coefficients of
electropassivating species. Application to pyrrole and phenol in aqueous solution
AB - Clean electrode surfaces can be achieved during the electrolysis of otherwise
passivating species in aqueous and other solutions by means of surface ablation
using a 10-Hz pulsed Nd:YAG 532-nm laser. This ability to remove passivating
electrolytically generated layers on glassy carbon and platinum electrodes is
shown first by an investigation of the stripping peaks formed from the
electrogeneration of the neutral forms of methyl viologen and heptyl viologen
during reduction in aqueous solution of dications. Next, laser ablation was
conducted under well-defined hydrodynamic conditions using a channel flow cell to
identify laser power thresholds below which transport-limited currents could be
seen, which were in quantitative agreement with those expected in the absence of
irradiation. Levich plots recorded in the channel flow cell for K4Fe(CN)6 at
glassy carbon and platinum electrodes showed such agreement for laser intensities
lower than 0.17 and 0.65 W cm(-2), respectively. Working at intensities below
these thresholds, steady-state voltammetry was observed for the oxidation of both
phenol and pyrrole at glassy carbon and platinum electrodes, respectively, in
aqueous solution. The diffusion coefficients of these two species were then
measured under hydrodynamic conditions using laser ablation voltammetry to
continuously clean the surface. Diffusion coefficients were inferred using the
Levich equation. The result for phenol at a pH of 12 in aqueous solution was 0.9
(+/-0.1) x 10(-5) cm2 s(-1), which is in good agreement with an independent
nonelectrochemical method. The diffusion coefficient of pyrrole in aqueous
solution was similarly evaluated as 1.25 (+/-0.1) x 10(-5) cm2 s(-1).
PMID- 10784151
TI - Ion-partitioning membrane-based electrochemical sensors
AB - The application of ion-partitioning membranes on proton transducers for the
development of electrochemical sensors is presented. The ion-partitioning
membrane incorporates two different ionophores, one selective to protons and the
other to analyte cations, as well as the necessary anionic lipophilic sites. As
dictated by the electroneutrality principle, when the concentration of the
analyte cations in the sample increases, the analyte cations are extracted into
the membrane, displacing protons of equal charge out of the membrane. The pH
sensitive gate of a CHEMFET or the surface of a glass pH electrode is used as an
internal transducer for the monitoring of the membrane proton flux. The resulting
signal of the pH transducer is related to the concentration of the analyte cation
present in the sample. The experiments presented here indicate that the observed
CHEMFET's signal is affected by the interaction of the pH-sensitive sensor
element with protons released by the polymeric membrane.
PMID- 10784152
TI - Lifetime of ion-selective electrodes based on charged ionophores
AB - The lifetime of solvent polymeric ion-selective electrodes (ISEs) is limited by
leaching of the membrane components into the sample solutions. In this article,
leaching of charged ionophores is discussed. Because of the electroneutrality
principle, the loss of the charged ionophore into the sample must be accompanied
by parallel transport of an ion of the opposite charge sign into the sample or by
ion exchange with a sample ion of the same charge sign. Because ionic sites of
high lipophilicity are available, the loss of ionic sites is, in general, not a
concern. Therefore, it is assumed here that the cotransported or ion-exchanging
ions are primary or interfering ions forming complexes with the ionophore. A
general theory that allows quantification of ionophore lipophilicities and a
discussion of changes in the membrane composition and selectivity with time is
presented. A high complex stability and high analyte concentrations diminish the
rate of ionophore loss into the sample if a charged ionophore is coextracted from
the membrane into the sample together with an analyte ion of opposite charge. On
the other hand, if the charged ionophore has the same charge sign as the ion that
it binds, a large binding constant and high analyte concentrations enhance
ionophore leaching into the sample. The model is applied to interpret results for
an electrically charged ionophore, for which selectivity changes as a function of
the leaching time were observed and the lipophilicity was determined with
potentiometric measurements. Using the lipophilicities of neutral ionophores, as
described previously, and the lipophilicities of charged ionophores, as described
here, a direct comparison of the expected leaching rates of charged and neutral
ionophores has become possible.
PMID- 10784153
TI - Simulations of the frequency response of implantable glucose sensors.
AB - The response of enzyme electrode glucose sensors implanted in tissues to
physiologic blood glucose oscillations is simulated. Models describe both oxygen
based and peroxide-based glucose sensors in spatially homogeneous medium
simulating some mass transfer properties of tissue. Pass-through ratios and
delays are reported as a function of frequency for the oxygen-based sensor, and
the effects on continuous blood glucose monitoring are illustrated using data
from the literature. Certain peroxide-based sensor designs may produce common
signals for different glucose concentrations, a characteristic not found in
oxygen-based sensors. The dynamic response depends on the frequency of glucose
oscillation and is sensitive to sensor type, enzyme activity, and diffusional
resistance.
PMID- 10784154
TI - Development of chemical sensors based on redox-dependent receptors. Preparation
and characterization of phenanthrenequinone-modified electrodes
AB - The study of phenanthrenequinone(PQ)-modified electrodes, prepared by
electropolymerization of a phenanthrenequinone-pyrrole derivative, is described.
The surface-confined PQ is shown to behave similarly to PQ in solution, acting as
a redox-dependent receptor toward aromatic ureas in aprotic solvents. Large,
positive shifts in the E1/2 of the PQ0/- redox couple are observed in the
presence of these ureas, due to a strong hydrogen bonding interaction between the
PQ radical anion and urea. The effect is fully reversible. Of the substrates
examined, only aromatic ureas produce a significant shift. Nonaromatic ureas or
other HN and HO containing compounds have little effect on the E1/2. The
magnitude of the shift is also independent of electrode coverage, allowing
reproducible measurements to be made despite significant loss in material from
the surface.
PMID- 10784155
TI - On-column surface-enhanced Raman spectroscopy detection in capillary
electrophoresis using running buffers containing silver colloidal solutions
AB - Direct on-column surface-enhanced Raman spectroscopy (SERS) detection is
demonstrated in capillary electrophoresis (CE). Distinctive SERS spectra of two
test compounds, riboflavin and Rhodamine 6G, are obtained in 100 microm i.d.
fused-silica capillaries under CE conditions using running buffers that contain
silver colloidal solutions. Detection is performed using an unmodified commercial
Raman spectrometer in a confocal microscope mode of operation. The effects of
laser power, wavelength, spectra acquisition time, silver colloidal
concentration, and applied voltage (i.e., flow rate) on the quality of SERS
spectra are evaluated. Using laser powers of 17 mW (at the sample) at 515 nm and
employing 1 s spectral acquisition times, spectra with bands exhibiting signal-to
noise ratios greater than 10 could be obtained for 1.0 x 10(-6) M riboflavin and
very low nanomolar concentrations of Rhodamine 6G. This was accomplished without
optimization of silver colloidal solution compositions and by using a low
throughput spectrometer. Incorporation of the colloidal solutions into running
buffers is shown to have little effect on the separation of the test compounds as
monitored using a laser-induced fluorescence instrumental scheme. However, SERS
spectra degrade if the capillary is not rinsed between experiments. Riboflavin
and Rhodamine 6G spectra are obtained on-the-fly for actual CE separations. In
the case of the latter solute, the injected quantity was approximately 90 amol.
PMID- 10784156
TI - Separation and detection of explosives on a microchip using micellar
electrokinetic chromatography and indirect laser-induced fluorescence
AB - A new approach for sensitive detection on a microfabricated chip is presented.
Indirect laser-induced-fluorescence (IDLIF) was used to detect explosive
compounds after separation by micellar electrokinetic chromatography (MEKC). The
detection setup was used in an epifluorescence configuration with excitation
provided by a near-IR diode laser operating at 750 nm. To achieve indirect
detection, a low concentration of a dye (5 microM Cy7) was added to the running
buffer as a visualizing agent. Using this methodology, a sample containing 14
explosives (EPA 8330 mixture) was examined. Concentrations of 1 ppm of
trinitrobenzene (TNB), trinitrotoluene (TNT), dinitrobenzene (DNB), tetryl, and
2,4-dinitrotoluene (2,4-DNT) could be detected with S/N ratios between 3 and 10.
Analyses showing 10 peaks, with plate numbers on the order of 60000, were
completed within 60 s using a 65 mm long separation channel. The three isomers of
nitrotoluene (2-, 3-, and 4-nitrotoluene) were not resolved. Additionally, the
two nitramines (HMX and RDX) could only be detected at much higher
concentrations, likely due to the low fluorescence quenching efficiencies of
these compounds. The analysis method was also used to separate and detect
nitroaromatic compounds in extracts from spiked soil samples. The presence of 1
ppm (1 microg of analyte/1 g of soil) of TNB, DNB, TNT, tetryl, 2,4-DNT, 2,6-DNT,
2-NH2-4,6-DNT, and 4-NH2-2,6-DNT could readily be detected. In the interest of
increasing the sensitivity of the analysis, various on-chip injection schemes
were evaluated. It was found that a 250 microm double-T injector gave a 35%
increase in peak signal compared to a straight-cross injector, which is less than
expected based on injected volume.
PMID- 10784157
TI - Speciation of dissolved iron(III) and iron(II) in water by on-line coupling of
flow injection separation and preconcentration with inductively coupled plasma
mass spectrometry.
AB - A method has been developed for the speciation of trace dissolved Fe(II) and
Fe(II) in water by on-line coupling of flow injection separation and
preconcentration with inductively coupled plasma mass spectrometry (ICPMS).
Selective determination of Fe(III) in the presence of Fe(II) was made possible by
on-line formation and sorption of the Fe(III)-pyrrolidinecarbodithioate (PDC)
complex in a PTFE knotted reactor over a sample acidity range of 0.07-0.4 mol L(
1) HCl, elution with 1 mol L(-1) HNO3, and detection by ICPMS. Over a sample
acidity range of 0.001-0.004 mol L(-1) HCl, the sum of Fe(III) and Fe(II), i.e.,
Fe(III + II), could be determined without the need for preoxidation of Fe(II) to
Fe(III). The concentration of Fe(II) was obtained as the difference between those
of Fe(III + II) and Fe(III). With a sample flow rate of 5 mL min(-1) and a 30-s
preconcentration time, an enhancement factor of 12, a retention efficiency of
80%, and a detection limit (3s) of 0.08 microg L(-1) were obtained at a sampling
frequency of 21 samples h(-1). The relative standard deviation (n = 11) was 2.9%
at the 10 microg L(-1) Fe(III) level. Recoveries of spiked Fe(III) and Fe(II) in
local tap water, river water, and groundwater samples ranged from 95% to 103%.
The concentrations of Fe(III) and Fe(II) in synthetic aqueous mixtures obtained
by the proposed method were in good agreement with the spiked values. The result
for total iron concentration in the river water reference material SLRS-3 was in
good agreement with the certified value. The method was successfully applied to
the determination of trace dissolved Fe(III) and Fe(II) in local tap water, river
water, and groundwater samples.
PMID- 10784158
TI - A large bore-direct injection high efficiency nebulizer for inductively coupled
plasma spectrometry
AB - A large bore-direct injection high efficiency nebulizer (IB-DIHEN) is introduced
that is less prone to capillary blockage and optimally operates at low nebulizer
gas pressures compared with the conventional DIHEN used for inductively coupled
plasma (ICP) spectrometries. The aerosol quality is examined using a two
dimensional phase Doppler particle analyzer (2D PDPA), and analytical figures of
merits are acquired by ICP mass spectrometry. Compared with the DIHEN, the LB
DIHEN produces larger droplets, but the velocity distributions and mean droplet
velocities are narrower and lower, respectively, providing longer residence times
for the droplets in the plasma. High RF power (1500 W), low nebulizer gas flow
rates (0.25-0.35 L/min), and low solution uptake rates (80-110 microL/min) are
required to operate the LB-DIHEN at optimum conditions for ICPMS. Detection
limits and sensitivities measured with the LB-DIHEN are superior to those of a
conventional nebulizer-spray chamber combination, but precision is inferior. The
performance of the LB-DIHEN is further explored in the determination of trace
elements in an herbal extract.
PMID- 10784159
TI - Phosphorescent oxygen sensors utilizing sulfur-nitrogen-phosphorous polymer
matrixes: synthesis, characterization, and evaluation of poly(thionylphosphazene)
b-poly(tetrahydrofuran) block copolymers
AB - We examine the use of thionylphosphazene-based block copolymers as matrixes for
oxygen sensor applications. Poly(aminothionylphosphazene)-b-poly(tetrahydrofuran)
(PATPy-PTHFx) block copolymers were prepared via reaction of ring-opened
poly(chlorothionylphosphazene) with THF and subsequently with excess n-butylamine
(to form PBATPy-PTHFx) or methylamine (to form PMATPy-PTHFx). The block
copolymers were characterized by NMR, gel permeation chromatography, and
differential scanning calorimetry. Films of PBATPy-PTHFx block copolymers
containing platinum octaethylporphyrin or [Ru(dpp)3]Cl2 (dpp = 4,7-diphenyl-1,10
phenanthroline) as the oxygen-sensitive chromophore were prepared, and time-scan
experiments were carried out to determine the diffusion coefficients, Do2, and
solubilities, So2, of oxygen therein. Despite microphase separation, the data fit
well to a simple Fick's law description of oxygen diffusion and gave Do2 values
smaller than that for the n-butylamino-substituted PBATP635. For films freshly
annealed above the melting point of PTHFx, the Do2 values were 35-50% (dye
dependent) larger than after aging 3 days at room temperature. Films with
[Ru(dpp)3]Cl2 as the dye were evaluated as media for phosphorescent pressure
sensing. The dye-containing polymer films exhibit linear Stern-Volmer-like plots,
even at high dye concentrations, as well as good photostability, and
significantly higher sensitivity to oxygen quenching than simple mixtures of the
analogous homopolymers.
PMID- 10784160
TI - On-line characterization of organic aerosols formed from biogenic precursors
using atmospheric pressure chemical ionization mass spectrometry.
AB - A method to investigate the chemical composition of organic aerosols formed from
biogenic hydrocarbon oxidation using atmospheric pressure chemical ionization
mass spectrometry (APCI/MS) is described. The method involves the direct
introduction of aerosol particles into the ion source of the mass spectrometer.
Using this technique, reaction monitoring experiments of alpha-pinene ozonolysis
show the formation of hetero- and homomolecular cluster anions (dimers) of the
primary oxidation products (multifunctional carboxylic acids). Since the
formation of dimers plays a profound role in new particle formation processes by
homogeneous nucleation in the atmosphere and, at the same time, is an intrinsic
feature of APCI, it is essential to differentiate between both processes when on
line APCI/MS is applied. In this paper, we compare the results from the
investigations of organic aerosols and artificially generated dimer cluster ions
of the same compounds using identical ionization conditions. The clusters and
their formation processes are characterized by varying the analyte concentration,
investigating the thermal stability of dimers, and studying collisional
activation properties of both ion species. The investigations show a significant
difference in ion stability: dimer anions measured on-line have an estimated
stability that is 20 kJ mol(-1) higher than that of the corresponding
artificially generated cluster ions. Hence, the technique provides the
possibility to accurately characterize dimers as ionized reaction products from
biogenic hydrocarbon oxidation and allows an insight into the process of new
particle formation by homogeneous nucleation.
PMID- 10784161
TI - Automated 96-well SPE and LC-MS-MS for determination of protease inhibitors in
plasma and cartilage tissues.
AB - Bioanalytical methods based on automated solid-phase extraction (SPE) and high
performance liquid chromatography with electrospray tandem mass spectrometry (LC
MS-MS) have been developed and utilized for the determination of MMP inhibitors
in plasma and cartilage tissues. The SPE methods were automated using a 96-well
extraction plate and a 96-channel programmable liquid-handling workstation. The
LC-MS-MS methods were developed using a rapid gradient LC separation, followed by
sample introduction through an ionspray interface in the positive ion mode and
tandem mass spectrometric detection with selected reaction monitoring. In the
optimized SPE methods, crude plasma or ground cartilage supernatant samples were
loaded onto an SPE plate to remove proteins and other interfering components in
the matrixes to render relatively clean extracts for LC-MS-MS analysis. Compared
to the simple plasma protein precipitation method, the automated SPE method
afforded significant time-saving in sample preparation and improved sensitivity
in MS detection. The methods were validated and successfully applied to the
analysis of protease inhibitors in plasma and cartilage tissues.
PMID- 10784162
TI - Accurate mass multiplexed tandem mass spectrometry for high-throughput
polypeptide identification from mixtures.
AB - We report a new tandem mass spectrometric approach for the improved
identification of polypeptides from mixtures (e.g., using genomic databases). The
approach involves the dissociation of several species simultaneously in a single
experiment and provides both increased speed and sensitivity. The data analysis
makes use of the known fragmentation pathways for polypeptides and highly
accurate mass measurements for both the set of parent polypeptides and their
fragments. The accurate mass information makes it possible to attribute most
fragments to a specific parent species. We provide an initial demonstration of
this multiplexed tandem MS approach using an FTICR mass spectrometer with a
mixture of seven polypeptides dissociated using infrared irradiation from a CO2
laser. The peptides were added to, and then successfully identified from, the
largest genomic database yet available (C. elegans), which is equivalent in
complexity to that for a specific differentiated mammalian cell type.
Additionally, since only a few enzymatic fragments are necessary to unambiguously
identify a protein from an appropriate database, it is anticipated that the
multiplexed MS/MS method will allow the more rapid identification of complex
protein mixtures with on-line separation of their enzymatically produced
polypeptides.
PMID- 10784163
TI - A disposable amperometric sensor screen printed on a nitrocellulose strip: a
glucose biosensor employing lead oxide as an interference-removing agent.
AB - A new type of disposable amperometric sensor is devised by screen printing thick
film electrodes directly on a porous nitrocellulose (NC) strip. The
chromatographic NC strip is then utilized to introduce various sample
pretreatment layers. As a preliminary application, a glucose biosensor based on
hydrogen peroxide detection is constructed by immobilizing glucose oxidase (GOx)
on the NC electrode strip and by formulating a strong oxidation layer (i.e.,
PbO2) at the sample loading area, placed below the GOx reaction band. The screen
printed PbO2 paste serves as a sample pretreatment layer that removes
interference by its strong oxidizing ability. Samples applied are carried
chromatographically, via the PbO2 paste, to the GOx layer, and glucose is
catalyzed to liberate hydrogen peroxide, which is then detected at the electrode
surface. The proposed NC/PbO2 strip sensor is shown to be virtually insusceptible
to interfering species such as acetaminophen and ascorbic and uric acids and to
exhibit good performance, in terms of the sensor-to-sensor reproducibility
(standard deviation, +/-0.026 - +/-0.086 microA), the sensitivity (slope, -0.183
microA/mM), and the linearity (correlation coefficient, 0.994 in the range of 0
10 mM).
PMID- 10784164
TI - Room-temperature imprinting method for plastic microchannel fabrication
AB - A new plastic imprinting method using a silicon template is demonstrated. This
new approach obviates the necessity of heating the plastic substrate during the
stamping process, thus improving the device yield from approximately 10 devices
to above 100 devices per template. The dimensions of the imprinted microchannels
were found to be very reproducible, with variations of less than 2%. The channel
depths were dependent on the pressures applied and the materials used. Rather
than bonding the open channels with another piece of plastic, a flexible and
adhesive poly(dimethylsiloxane) film is used to seal the microchannels, which
offers many advantages. As an application, isoelectric focusing of green
fluorescence protein on these plastic microfluidic devices is illustrated.
PMID- 10784165
TI - Sweeping of neutral analytes in electrokinetic chromatography with high-salt
containing matrixes
AB - The concept of sweeping neutral analytes using a high-conductivity matrix or
under a reduced electric field in micellar electrokinetic chromatography (MEKC)
using anionic micelles and in the presence of electroosmotic flow is presented.
Three important processes are identified. First, stacking of the micelles at the
cathodic interface between the sample solution (S) and background solution (BGS)
zones is identified. This is then followed by the sweeping of analyte molecules
by the stacked micelles that enter the S zone. Finally, the destacking of the
stacked micelles at the anodic interface between the S and BGS zones occurs. The
stacking of the micelles improves the focusing effect of sweeping by a factor
approximately equal to the ratio of conductivities between the S and BGS zones
(ratio = enhancement factor = gamma'). However, the destacking of the stacked
micelles broadens the swept zones by a factor approximately equal to 1/gamma'. In
effect, the focusing effect of sweeping using a matrix with equal or higher
conductivity compared to the BGS will be roughly the same. The micelle stacking
and destacking mechanisms are verified experimentally. This paper also provides
comments on the mechanism of neutral analyte focusing under similar conditions
proposed by another group.
PMID- 10784166
TI - Artificial insemination outcomes in beef females using bovine sperm with a
detectable fertility-associated antigen.
AB - In this study, semen samples from 25 bulls that had passed a breeding soundness
evaluation were analyzed for the presence or absence of a 31-kDa protein, known
as fertility-associated antigen (FAA), on spermatozoal membranes. Eighteen bulls
had FAA on sperm (FAA-positive) and seven were devoid of FAA on sperm (FAA
negative). A single ejaculate from each bull was extended and frozen with 25 to
30 x 10(6) sperm in .5-mL straws. Crossbred replacement heifers (n = 865) were
estrus-synchronized and artificially inseminated either at timed AI or 12 h after
they were detected in estrus. Mature cows (n = 285) were inseminated 12 h after
they were detected in estrus during a 45-d AI period. Pregnancy rates (pooled) to
first AI service for females (n = 764) inseminated with FAA-positive sperm were
65.6% and were 49.7% for females (n = 386) inseminated with FAA-negative sperm (P
< .005). Among the estrus-synchronized replacement heifers, pregnancy rates to
synchronized AI service for heifers (n = 550) inseminated with FAA-positive sperm
were 62% and were 45.7% for heifers (n = 315) inseminated with FAA-negative sperm
(P < .005). These data indicate that pregnancy rates to first AI service at
spontaneous and synchronized estrus are higher when using semen from bulls with
detectable FAA on spermatozoal membranes compared to semen from bulls devoid of
FAA on membranes. Fertility-associated antigen is an important determinant for
fertility potential of sperm from bulls to be used in AI breeding programs.
PMID- 10784167
TI - Prediction of crude fat content of longissimus muscle of beef using the ratio of
fat area calculated from computer image analysis: comparison of regression
equations for prediction using different input devices at different stations.
AB - Crude fat content of longissimus (ribeye) muscle of beef cattle was predicted
from a ratio of fat area (RFA) to area of ribeye muscle calculated from computer
image analysis (CIA). Cross sections of 64 ribeyes taken from the 6-7th rib from
cattle at experiment station A and cross sections of 94 ribeyes taken from the 6
7th rib from cattle at Experiment Station B were used in this study. Slices (1 to
1.5 cm in thickness) of just the Longissimus dorsi were homogenized and sampled
for chemical estimation of crude fat content using petroleum ether. Crude fat
content as determined from chemical analysis was used as the true estimate of fat
content. A CCD (charge-coupled device) camera was used as the input device at
Experiment Station A, and a single-lens reflex camera was used at Experiment
Station B to photograph ribeyes for CIA. The contour comparison method, which
assigns a threshold value for each marbling particle, was used to obtain accurate
binarization in this study. Minimum and maximum of chemical measurements of crude
fat were 2.1 and 39.8%, and for CIA calculation of the RFA were 6.1 and 56.8%,
respectively. This range covered almost the complete range of the beef marbling
standard used in carcass grading in Japan. The equation for the regression of the
crude fat content (Y) on RFA (X) calculated from CIA for all of the data was Y =
.793X-3.04 with r2 = .96. Regression equations for prediction of crude fat
percentage from RFA taking into consideration the effect of experiment station
were Y = .741X-2.22 with r2 = .91 for Experiment Station A, and Y = .782X-2.54
with r2 = .91 for Experiment Station B. Analysis of covariance showed that the
effects of experiment stations on intercepts and slopes were not significant (P >
.10). The ranges of differences between actual and predicted crude fat content
from the prediction equation that was calculated without consideration of the
effect of station were -6.4 to 4.0%. CIA of cross sections of the ribeye muscle
seems to have potential for prediction of crude fat content.
PMID- 10784168
TI - Evaluation of calpastatin activity measures in ante- and postmortem muscle from
half-sib bulls and steers.
AB - Calpastatin activity measured at 24 h postmortem in bovine longissimus muscle
(PMLD24) is correlated with Warner-Bratzler shear force (WBS) measurements, an
objective measure of tenderness. A live-animal measurement of calpastatin
activity that correlates with 24-h postmortem activity would provide information
for selection programs without the expense of progeny testing. The purpose of
this study was to evaluate the effectiveness of calpastatin activity measurements
obtained on tissue samples from live animals and to determine the relationship
among various calpastatin activity measures and tenderness determined by WBS and
sensory panel. Biopsies (approximately 10 g) were obtained surgically 2 d before
slaughter from the supraspinatus muscle on the anterior surface of the scapula
(LISH0) from contemporary purebred Angus bulls (n = 12) and steers (n = 17).
Biopsies from a subset of these cattle (n = 12) were refrigerated at 4 degrees C
to simulate the postmortem cooling process for 24 h (LISH24) prior to extraction.
A rib section anterior to the 12 and 13th rib interface was collected from all
animals at the commercial abattoir between 22 and 23 h postmortem for PMLD24,
sensory panel, and WBS measurements. A postmortem shoulder muscle sample (PMSH24)
was collected at the same time. Calpastatin was extracted from all muscle samples
using a heated calpastatin activity protocol. Sensory panel tenderness, WBS,
LISH0, LISH24, and PMSH24 were not different between bulls and steers. However,
PMLD24 values were significantly different. Significant partial correlations were
found between WBS and sensory panel tenderness (-.55), between WBS and PMLD24 (
.43), and between LISH24 and PMLD24 (.78). Therefore, similar calpastatin
activity values are possible with ante- and postmortem tissue samples, suggesting
the possibility of using measurements from live-tissue biopsies from other than
the longissimus muscle to predict end product tenderness.
PMID- 10784169
TI - Polyethylene glycol as a means for reducing the impact of condensed tannins in
carob pulp: effects on lamb growth performance and meat quality.
AB - We conducted an experiment to evaluate the effects that a diet containing
condensed tannins with and without polyethylene glycol (PEG) has on lamb growth
and meat quality. Twenty-three male Comisana lambs were introduced to the three
experimental diets between 45 and 50 d of age. Eight were given a diet containing
56% of Ceratonia siliqua (carob) pulp (tannin group), another eight received the
same diet with a supplement of 40 g of PEG for each kilogram of diet (PEG group),
and the remaining seven lambs were given a conventional maize-based diet (maize
group). Voluntary feed intake and live weights were measured until slaughter at
105 d of age, and digestibility measurements were undertaken toward the end of
the feeding trial. Carcass yield, meat quality characteristics, and a taste panel
evaluation were conducted. The tannin-based diet contained 2.5% condensed tannins
(DM basis), and lambs given this diet had lower growth rates and poorer feed
efficiencies (P < .01) compared with the other treatment groups. Daily gain was
similar between the maize and PEG lambs, although the efficiency of feed
conversion was highest in the maize group. The digestibility of DM, N, and fiber
was reduced (P < .05) by the condensed tannins. Lambs fed the tannin diet had a
lower carcass yield (P < .05) and had less fat (P < .05), and the meat had a
higher ultimate pH (P < .01) than those given the PEG or maize diets. Condensed
tannins affected meat color, which was lighter (L*) than meat from lambs given
the PEG-containing diet (P < .01). Sensory evaluation showed that panelists
preferred meat from lambs receiving PEG and maize treatments compared with those
receiving the tannin diet, and this could be related to differences in meat
ultimate pH and carcass fatness. These results show that condensed tannins from
carob pulp are very detrimental to feed digestibility and lamb performance.
Inclusion of 40 g of PEG/kg diet eliminated the effects of condensed tannins so
that lamb performance and meat quality were similar to lambs given a maize-based
diet.
PMID- 10784170
TI - Endocrine studies in ivermectin-treated heifers from birth to puberty.
AB - Continuous treatment with ivermectin from birth to puberty advanced sexual
maturation by 3.7 wk in Holstein heifers grazing pastures naturally infected with
nematodes. Every 14 d jugular blood samples were taken from birth to 45 wk of age
from all heifers. No differences in serum FSH, estradiol, or thyroxine levels
were observed during the trial between the treated and untreated group. Mean LH
levels were diminished in untreated heifers 4 wk before the first estrus and the
amplitude of LH pulses was augmented in treated heifers when puberty was reached.
Serum IGF-I levels increased from birth to 22 wk of age and then reached a
plateau in both groups, but levels were consistently higher in treated heifers
from 26 wk of age onward. Body weight gain was retarded in parasitized heifers
and IGF-I values were positively correlated with body weight only during the
first 20 wk of life. We suggest that enhanced prepubertal IGF-I levels in
conjunction with increased prepubertal LH levels and pubertal LH pulse amplitude
might be involved in the accelerated somatic maturation and in puberty
advancement observed in ivermectin-treated heifers.
PMID- 10784171
TI - Effects of energy intake, implantation, and subcutaneous fat end point on feedlot
steer performance and carcass composition.
AB - The purpose of this experiment was to evaluate the effects of energy intake,
implantation, and fat end point on feedlot performance and carcass composition of
steers. Three hundred eighty-four yearling crossbred steers (368 +/- 23.1 kg)
were allotted in a completely randomized design. Treatments were arranged in a 2
x 3 x 2 factorial experiment. Main effect factors were two levels of intake,
three implant strategies, and two compositional fat end points at slaughter. The
levels of intake were ad libitum (AL) and restricted (RS) intake (90% ad
libitum). The three implant strategies were Revalor-S (REV) (120 mg trenbolone
acetate, 24 mg estradiol), Synovex-Plus (SYN) (200 mg trenbolone acetate, 28 mg
estradiol benzoate), and no implant (control). The compositional target end
points were 1.0 and 1.4 cm s.c. fat cover over the 12th and 13th rib. Restricted
intake steers consumed 9.2% less (P < .01) DM than AL steers. Ad libitum-intake
steers gained weight 15.5% more rapidly (P < .01) than RS-intake steers. Steers
implanted with REV tended (P < .07) to gain faster than SYN steers, who in turn
gained 15.2% more (P < .01) than control steers. Ad libitum-intake steers were
4.8% more (P < .01) efficient than RS steers. Steers fed to a targeted 1.4 cm
s.c. backfat cover were 2.9% less (P < .05) efficient than steers fed to 1.0 cm,
and steers implanted with either REV or SYN had similar (P = .47) feed
efficiencies, whereas control steers had lower (P < .01) feed efficiencies.
Steers fed to a targeted compositional fat end point of 1.4 cm had 1.3% higher (P
< .01) dressing percentage (DP) than steers fed to 1.0 cm. Control and SYN steers
had similar (P = .13) DP; however, REV steers had 6.1% greater (P < .01) DP than
SYN steers. Steers fed to 1.4 cm s.c. fat end point had higher (P < .01)
numerical yield grades than steers fed to 1.0 cm (3.34 vs 2.71). There was an
interaction (P < .01) for intake level and implant for marbling score. Marbling
scores were lower (P < .05) for RS x SYN and AL x REV than in other treatments.
Steers on the RS x REV treatment were intermediate in marbling to all treatments
except AL control, which was higher (P < .01) than RS x SYN, AL x REV, and RS x
REV. No interaction for dry matter intake level and anabolic implants was
observed for growth performance. The depression in carcass quality resulting from
implanting is reduced as backfat increases from 1.0 to 1.4 cm at slaughter.
PMID- 10784172
TI - Response to 13 generations of selection for increased 8-week body weight in lines
of mice carrying a sheep growth hormone-based transgene.
AB - The purpose of this study was to evaluate selection in lines of transgenic mice.
Two replicates of lines that either carried or did not carry the sheep
metallothionein-1a sheep growth hormone transgene (oMt1a-oGH) were established.
The host lines had been previously selected for rapid growth or selected
randomly. Within-litter selection for increased 8-wk body weight was carried out
for 13 generations. The frequency of oMt1a-oGH was monitored in all generations
in the transgenic lines, but no genotypic information regarding the transgene was
used as an aid to selection. The oMt1a-oGH was activated from weaning, at 3 wk,
until 8 wk of age by adding ZnSO4 to the drinking water. Zinc stimulation of the
transgene was not done during mating, gestation, or lactation. Data on body
weights and weight gains were analyzed with a conventional mixed model and with
an animal model. Genetic progress was achieved in all lines subjected to
directional selection. In the control background, response to selection for 8-wk
body weight was larger in the nontransgenic lines than in the transgenic lines,
whereas no difference was found in the selected background. The frequency of the
transgene was increased from the initial .5 to .62 in the randomly selected
background but decreased to .04 in lines from a selected background. The REML
estimates of variance components and genetic gain estimates varied greatly
between the two methods. In general, there was better agreement between the
realized heritability estimates and the heritability estimates obtained from the
conventional mixed model analysis than between realized heritability estimates
and results obtained using the animal model. Favorable correlated responses were
obtained for 3- and 6-wk body weights and on 3- to 6- and 6- to 8-wk weight
gains. Correlated responses to selection were larger in the selected than in the
nonselected background but were not affected by the presence of the transgene.
Results suggest that constructs similar to the oMt1a-oGH, which allow tight
regulation, may be successfully incorporated into commercial livestock and should
have larger effects in populations that have not been subject to selection.
PMID- 10784173
TI - Genetic parameters among weight, prolificacy, and wool traits of Columbia,
Polypay, Rambouillet, and Targhee sheep.
AB - Genetic parameters for Columbia, Polypay, Rambouillet, and Targhee sheep were
estimated using REML with animal models for prolificacy, weight, and wool traits.
All bivariate analyses included a covariance between additive genetic effects for
the two traits plus appropriate additional covariances. Number of observations by
breed ranged from 5,140 to 7,095 for prolificacy traits, from 7,750 to 9,530 for
weight traits, and from 4,603 to 34,746 for wool traits. Heritability estimates
ranged from .03 to .11 for prolificacy traits (litter size at birth and litter
size at weaning), from .09 to .26 for weight traits (birth weight and average
daily gain), and from .25 to .53 for wool traits (fleece weight, fleece grade and
staple length). Estimates of direct genetic correlations among prolificacy and
among weight traits were positive and ranged from .58 to 1.00 and .18 to 1.00,
respectively. Estimates of direct genetic correlation between fleece weight and
staple length were positive (.50 to .70) but were negative between fleece weight
and fleece grade (-.60 to -.34) and between staple length and fleece grade (-.72
and -.40). Prolificacy and wool traits were essentially uncorrelated. Weight and
prolificacy traits were slightly positively correlated. Weight traits had a
moderate positive direct genetic correlation with fleece weight and staple
length, but were uncorrelated with fleece grade. These estimates of genetic
parameters between prolificacy, weight, and wool traits can be used to construct
multiple-trait selection indexes for dual-purpose sheep.
PMID- 10784175
TI - Effects of eating space and availability of water in feeders on productivity and
eating behavior of grower/finisher pigs.
AB - Three experiments were conducted to determine the effects of eating space and
availability of water within feeders on the productivity and behavior of
growing/finishing pigs. In Exp. 1, 12 commercial feeders were classified as being
either single-space (SS) or multiple-space (MS), and either as dry (D) or wet/dry
(WD), resulting in two SS-D, four MS-D, three SS-WD and three MS-WD models. Each
model was evaluated using four pens of 12 pigs, which were fed a mash diet
throughout the growing/finishing period (25 to 106 kg). Pigs were videotaped when
they were approximately 40 and 80 kg in weight to determine eating behavior. The
number of feeding spaces did not affect the productivity of the pigs, but the
presence of water within the feeder resulted in increases in ADFI (P < .05) and
ADG (P < .05) and a reduction in carcass lean (P < .05). Pigs eating from SS
feeders spent 15% less time eating than those fed from two-space feeders (P <
.05), and occupancy rate for feeding spaces was increased by 75% (P < .05). The
WD feeders also resulted in a reduction (17%) in eatingtime compared to D models
(P < .01), and occupancy rate for WD feeders was similarly reduced (P < .05).
Pigs spent 16% less time eating when they weighed approximately 80 kg than when
they weighed 40 kg (P < .01). In Exp. 2, rate of eating was determined during a
short test on the same 12 feeder models for both small (48 kg) and large (90 kg)
pigs. Large pigs ate faster than small pigs, but eating rate was not affected by
feeding space or presence of water in the feeder. In Exp. 3, eating rate was
determined for small amounts of dry or wet feed. Premixing water with the feed
(1:1 ratio by weight) increased eating speed (P < .01). We concluded that 12 pigs
can be fed from a single-space feeder without affecting productivity. The
inclusion of water within a feeder decreases time spent eating, but it increases
ADFI and ADG. When pigs are small, they spend more time eating, and feeder
occupancy rates are higher than when they are large.
PMID- 10784174
TI - High dietary copper improves odor characteristics of swine waste.
AB - We conducted two experiments to determine the effects of dietary copper
concentration and source on odor characteristics of swine waste. In both
experiments, 192 weanling gilts and barrows were allotted to 24 pens. Pens were
randomly assigned to one of six dietary treatments, consisting of control (10 ppm
Cu as cupric sulfate, CuSO4), 66 or 225 ppm Cu as CuSO4, or 33, 66, or 100 ppm Cu
as cupric citrate (Cucitrate). An antibiotic was included in the diets for Exp.
1, but not Exp. 2. On d 28, fecal samples were randomly obtained from one pig per
pen and stored at -20 degrees C until preparation and evaluation by an odor
panel. The odor panel consisted of 10 individuals, and each panelist evaluated
the odor intensity, irritation intensity, and odor quality of the samples. In
Exp. 1, the odor and irritation intensity of the feces were lower (P < .05) from
animals consuming diets containing 225 ppm Cu as CuSO4 and 66 or 100 ppm Cu as Cu
citrate compared to the control. The odor quality of the waste from animals
consuming diets containing 225 ppm Cu as CuSO4 and 66 or 100 ppm Cu as Cu-citrate
was improved (P < .05) compared to the 33 ppm Cu treatment. In Exp. 2, the odor
intensity of the feces of pigs receiving diets supplemented with all
concentrations of Cu-citrate was lower (P < .05) than that of feces from the
control animals. Irritation intensity of the feces was not affected by treatment.
Odor quality of waste of pigs supplemented with 225 ppm Cu from CuSO4 and all
concentrations of Cu-citrate was improved (P < .05) compared to that of waste of
the control pigs. Two gilts and two barrows from each nursery pen in Exp. 1 were
continued through the growing-finishing phase on their respective experimental
diets. The growing-finishing phase lasted 103 d, and fecal samples were randomly
obtained from one pig per pen at the completion of the phase. During the growing
finishing phase, the odor intensity and the irritation intensity of the feces
were lower (P < .05) from pigs supplemented with 66 and 225 ppm Cu as CuSO4 and
66 and 100 ppm Cu from Cu-citrate than from the control pigs. The odor quality of
the waste was improved (P < .05) in all animals receiving supplemental Cu. These
data indicate an improvement in odor characteristics of swine waste with the
supplementation of Cu. In addition, lower concentrations of an organic nonsulfate
Cu source resulted in similar odor characteristics of swine waste as 225 ppm
CuSO4.
PMID- 10784176
TI - Effects of boar contact and housing conditions on estrus expression in weaned
sows.
AB - Our objective was to study the effects of housing conditions and the amount of
boar contact in a protocol for estrus detection on estrus detection rate, timing
of onset of estrus, duration of estrus, and timing of ovulation. After weaning,
130 multiparous sows were assigned to three treatments: HI, in which 52 sows were
housed individually in crates and received a high amount of boar contact during
estrus detection; HG, in which 52 sows were housed in groups and received a high
amount of boar contact; and NI, in which 26 sows were housed individually in
crates and received a normal amount of boar contact. Estrus detection was
performed every 8 h. For each treatment, the standing response to three levels of
stimuli was recorded: a back pressure test (BPT) by a man (man-estrus), presence
of a teaser boar (spontaneous-estrus), and BPT in the presence of a teaser boar
(boar-estrus). In addition, for HI and HG, the standing response to a fourth
level of stimuli was recorded: BPT in a detection-mating area, surrounded by four
boar pens (DMA-estrus). To detect ovulation, ultrasonography was performed every
4 h during estrus. Of 117 sows that ovulated, 46% showed man-estrus, 56%
spontaneous-estrus, 90% boar-estrus, and 97% DMA-estrus. Mean onset of man-estrus
was 107 h (SD 26) after weaning, of spontaneous-estrus was 106 h (SD 22) after
weaning, of boar-estrus was 99 h (SD 21) after weaning, and of DMA-estrus was 93
h (SD 22) after weaning. Duration of man-estrus was 22 h (SD 14), of spontaneous
estrus was 29 h (SD 16), of boar-estrus was 42 h (SD 20), and of DMA-estrus was
55 h (SD 18). The high amount of boar contact reduced the number of sows showing
man-estrus (P < .05; 41% for HG and HI vs 68% for NI) and reduced duration of
boar-estrus (P < .05; 43 h for HG and HI vs 52 h for NI). Duration of DMA-estrus
for HG and HI was similar to duration of boar-estrus for NI. Onset of estrus and
timing of ovulation were not affected by amount of boar contact. Group housing
did not affect detection rate and duration of estrus, but it did postpone average
onset of estrus by 10 h, paralleled by a postponement of ovulation. In
conclusion, estrus expression is similar at the highest level of stimuli in
different protocols for estrus detection. Including higher levels of stimuli in a
protocol reduces estrus expression at lower levels of stimuli. This reduction
indicates adaptation of sows to a given protocol for estrus detection. Group
housing can delay ovulation and related behavioral estrus.
PMID- 10784177
TI - Hand-feeding and gentling influence early-weaned lambs' attachment responses to
their stockperson.
AB - Artificially reared herbivores are highly dependent on the stockperson at an
early age in order to learn to drink from an artificial milk provider. This
period of training may be a determinant for the animals' subsequent responses
toward humans. However, long-term responses may also depend on the human contact
(e.g., visual, physical interactions, gentling, and handling) provided to the
young lambs after this training period. We examined whether different levels of
subsequent contact (no visual and physical contact, stroking, and feeding reward)
affect long-term attachment responses of lambs to the caretaker that provided the
subsequent contact, after a common initial training period for artificial feeding
provided by another person. Ewe lambs (n = 45) were artificially reared from
multinippled buckets in groups of three. All the lambs were trained by a
stockperson (S1) to suck from the bucket (4.4 +/- .3 sessions of 3 min per animal
for the first 2 d of life). Subsequently, 15 lambs received no further human
contact (T0). Fifteen other lambs received only stroking from a second
stockperson (S2) for 6 min three times a day during the first 4 wk (T1). The
remaining 15 lambs (T2) were stroked and bottle-fed by S2 during the same
posttraining period as for T1. Tests were performed at 4, 6 (just before
weaning), 9, and 13 wk of age in an unfamiliar arena marked in a grid pattern.
The test procedure included three successive parts: 1) isolation for 1 min; 2) S2
presence for 2 min; and 3) isolation for 1 min. The T0 lambs spent a similar
amount of time in the grid square close to S2 regardless of whether he was
present. The T1 and T2 lambs spent more time close to S2 than T0 (P < .01), and
T2 spent more time close than T1 (P < .05). In the presence of S2, T2 vocalized
less (P < .01) than T0, and T1 did not differ from either T2 or T0. The T2 lambs
also crossed fewer squares than T0. When S2 left the arena, T2 vocalized more (P
< .01) than T0 and more (P < .05) than T1, and T1 had a tendency to vocalize more
(P = .08) than T0. Differences persisted with increasing age. Human contact,
especially stroking and feeding, during the 4 wk following initial training
strongly and durably influenced the lambs' response not only to the appearance
but also to the disappearance of a familiar stockperson. This last result
supports the idea that lambs could form a social bond with their stockperson.
PMID- 10784178
TI - Culture of porcine stromal-vascular cells in serum-free medium: differential
action of various hormonal agents on adipose conversion.
AB - We developed a strictly controlled serum-free culture system and tested the
effects of adipogenic and antiadipogenic agents on the proliferation and(or)
adipose conversion of porcine stromal-vascular cells. To avoid any interference
with serum components, stromal-vascular cells were isolated, plated, and grown in
absence of serum. In these culture conditions, a very limited growth phase and
the absence of cell confluence were observed. However, when compared with
continuous culture in serum-containing medium, the serum-free conditions were
significantly more adipogenic as assessed by increased lipid content and
increased enzymatic activities for lipoprotein lipase, glycerol 3-phosphate
dehydrogenase, and malic enzyme. In serum-free medium, physiological
concentrations of insulin or IGF-I were sufficient to significantly increase the
percentage of lipid-containing cells, whereas triiodothyronine (T3) and GH had no
effect. Insulin, IGF-I, and, more moderately, T3 also accelerated the lipid
filling in the lipid-containing cells. In the presence of insulin, stimulation by
T3 or hydrocortisone alone had no effect on glycerol 3-phosphate dehydrogenase
activity, whereas their concomitant addition significantly increased it. Chronic
exposure to tumor necrosis factor-alpha dose-dependently stimulated cell
proliferation but clearly inhibited differentiation. Epidermal growth factor,
another known antiadipogenic agent, also significantly increased the
proliferation of stromal-vascular cells, but, surprisingly, this was not
correlated with inhibition of adipocyte differentiation. Indeed, epidermal growth
factor treatment did not decrease lipid filling and significantly improved
lipoprotein lipase and malic enzyme activities. Taken together, the results
obtained in these strictly controlled serum-free culture conditions point out
functions for insulin, IGF-I, hydrocortisone, and T3 during early and(or) later
steps of porcine adipose conversion. In addition, this study reports a positive
activity of epidermal growth factor on porcine adipocyte differentiation that is
in clear contrast with previous works performed with rodent cells.
PMID- 10784179
TI - Influence of feeding different amounts of first colostrum on metabolic,
endocrine, and health status and on growth performance in neonatal calves.
AB - Colostrum intake is important for health and postnatal development of neonatal
calves. We studied the effects of enhanced first colostrum feeding on growth,
health status, and metabolic and endocrine traits in calves during their 1st wk
of life. Calves of group CL (GrCL; n = 7) were fed colostrum of milkings 1 to 6
twice daily during the first 3 d of life, followed by milk replacer (MR) up to d
7. Calves of group CH (GrCH; n = 7) were fed colostrum of the first milking
during the first 3 d and then colostrum (of the first milking) twice daily, which
on d 4, 5, 6, and 7 was diluted with 25, 50, 75, and 75 parts of MR,
respectively. Pre- and postprandial blood samples were taken on d 1, 2, 3, and 7
for the determination of various metabolic and endocrine traits, and on d 5
intestinal absorption capacity was measured using the xylose absorption test.
Rectal temperatures and fecal scores were higher (P < .05) in GrCH than in GrCL.
Plasma concentrations of total protein and albumin were higher (P < .05) on d 7,
IgG on d 2 and 3, and urea on d 2, 3, and 7 in GrCH than in GrCL. Plasma
concentrations of triglycerides were higher (P < .05) on d 2 and of phospholipids
and cholesterol were higher (P < .01) on d 7 in GrCH than in GrCL. Plasma insulin
and glucagon concentrations were higher (P < .05) in GrCH than in GrCL, whereas
prolactin and growth hormone concentrations were higher (P < .05) in GrCL than in
GrCH. Enhanced colostrum intake had no effects on xylose absorption on d 5.
Higher plasma protein, urea, and lipid concentrations in GrCH partly mirrored
higher protein and fat intake but additionally pointed to higher protein
synthesis and lipid turnover.
PMID- 10784180
TI - Plasmid transfection and retroviral transduction of porcine muscle cells for cell
mediated gene transfer.
AB - Cell-mediated gene transfer is a potential tool for studying muscle growth, but
efficient genetic manipulation and implantation strategies have not been
developed for pigs. The objectives of the present study were to determine methods
for transient and stable incorporation of reporter genes into porcine muscle
cells and to investigate their use for cell-mediated gene transfer in pigs.
Porcine myoblasts and fibroblasts were isolated from muscle of 2-wk-old male
pigs. Myogenic cell lines were identified using muscle-specific monoclonal
antibodies, myotube fusion assays, and the presence of muscle-specific markers
(MyoD and desmin). Four commercial cationic liposomes (lipofectAMINE, lipofectin,
cellFECTIN, and DMRIE-C) were tested at different DNA:lipid ratios for their
ability to transfect myoblasts and fibroblasts transiently with a luciferase
reporter plasmid. LipofectAMINE resulted in the greatest (P < .01) transient
luciferase activity for both cell types. Electroporation of cells for transient
transfection resulted in less luciferase activity than cationic transfection.
Stable transfections were conducted using a green fluorescence protein (GFP)
reporter plasmid containing the neomycin resistance gene. LipofectAMINE
transfection resulted in stable GFP expression in 1:16,000 myoblasts and 1:33,000
fibroblasts. Stable electroporation resulted in efficiencies that were
significantly lower than established with cationic liposomes. Porcine cells were
transduced with GFP using vesicular stomatitis virus glycoprotein G pseudotyped
retrovirus and resulted in efficiencies of 1:1.2 for myoblasts and 1:1.1 for
fibroblasts. These results show that cationic liposomes are superior to
electroporation for transfection, but retroviral transduction produced stable
reporter gene expression in > 80% of porcine muscle cells. Transduced GFP
positive cells were separated from GFP-negative cells by fluorescence-activated
cell sorting and implanted into 2-wk-old male pigs. On d 4, implanted muscles
were removed and subjected to immunodetection of GFP protein. Fibroblast
implantation resulted in limited GFP expression within muscle, whereas myoblast
implantation resulted in GFP within muscle fibers. This suggests that cell
mediated gene transfer is possible in porcine muscle and may be useful as an
approach for studying muscle growth in pigs.
PMID- 10784181
TI - Modulation of porcine adipocyte beta-adrenergic receptors by a beta-adrenergic
agonist.
AB - Mammalian cells have several mechanisms to decrease the response to beta
adrenergic agonists. Agonists are metabolized or taken up by nerve endings. The
beta-adrenergic receptors (betaAR) are inactivated by phosphorylation and removed
from the cell membrane, and synthesis is decreased or degradation is increased.
Knowledge about adipocyte betaAR desensitization is mostly from rodent adipocytes
with > or = 90% beta3AR. Porcine adipocyte betaAR have functional and ligand
binding properties that are quite different from those in many other species.
Furthermore, the predominant betaAR subtype in the porcine adipocyte is the
beta1AR (70 to 80%). Given these species differences, it might be expected that
desensitization in porcine adipocytes would not be totally concordant with the
rodent-derived model. Isolated porcine adipocytes were incubated without or with
a betaAR agonist, isoproterenol. The total betaAR number, measured by ligand
binding in a crude membrane fraction, tended to be lower after 6 h of incubation
without isoproterenol. The addition of 10(-5) M isoproterenol during the
incubation caused the betaAR number to decrease 43% compared to cells incubated
without isoproterenol. The beta1AR and beta2AR transcript concentrations both
decreased 45% after 6 h of incubation without isoproterenol. There was no
decrease in mRNA when cells were incubated with isoproterenol. The results
suggest the betaAR were desensitized by incubation with isoproterenol, perhaps by
phosphorylation and removal from the membrane, but this was not accompanied by
modulation of the concentration of transcripts for beta1AR or beta2AR.
PMID- 10784182
TI - Modulation of porcine adipocyte beta-adrenergic receptors by hormones and
butyrate.
AB - The beta-adrenergic receptors (betaAR) on the surface of mammalian cells are
desensitized when the cell is stimulated by betaAR agonists to eliminate
excessive response by the cell. Investigations with adipocytes, primarily rodent
derived cells, indicate other hormones and substrates also can modulate the
individual betaAR subtypes. For example, glucocorticoids decrease the beta1AR and
the beta3AR but increase the beta2AR. Insulin decreases the beta3AR. Thyroid
hormones increase the beta3AR and butyrate increases beta1AR and beta2AR but
dramatically decreases beta3AR. Because porcine adipocytes have unique functional
and ligand-binding properties compared to rodent adipocytes and because porcine
adipocytes contain predominantly beta1AR, compared to rodent adipocytes with
predominantly beta3AR, we expect the regulation of porcine adipocyte betaAR by
hormones and substrates to be different from that in rodent adipocytes. Isolated
porcine adipocytes were incubated for 6 and 21 h without and with dexamethasone,
insulin, triiodothyronine, or butyrate. Cells incubated without hormone or
butyrate had a decreased betaAR number at 21 h. The beta1AR and beta2AR
transcript concentrations were decreased after 6 h and tended to rebound after 21
h of incubation. Dexamethasone did not change the total betaAR number but tended
to increase the beta1AR and beta2AR transcript concentrations. Insulin increased
the betaAR number and decreased both transcript concentrations at 21 h.
Triiodothyronine and butyrate did not change the receptor number or transcript
concentrations. The results indicate that betaAR transcript concentrations do not
accurately predict the betaAR protein concentration (estimated by ligand
binding). Results also indicate that betaAR in porcine adipocytes are relatively
unresponsive to hormones and butyrate compared to rodent-derived adipocytes
described in the literature.
PMID- 10784183
TI - Effect of feed restriction on adipose tissue transcript concentrations in
genetically lean and obese pigs.
AB - To determine possible genetic influences on the steady-state concentrations of
several key transcription factor transcripts and the transcript concentrations
for adipocyte-characteristic proteins, young, genetically obese and lean pigs
were given ad libitum access or feed or were restrictively fed at 50% of ad
libitum intake for 5 wk. Obese pigs were smaller and fatter than lean pigs,
whether intake was ad libitum or restrictive. Plasma protein, albumin, and
cholesterol concentrations were greater in obese than in lean pigs. Plasma NEFA,
blood urea nitrogen, triacylglycerols, and postprandial glucose and insulin
concentrations were less (P < .02) in pigs fed restrictively than in pigs with ad
libitum access to feed, regardless of genetic group. The adipose tissue glucose
transporter 4, fatty acid synthase, and leptin transcript concentrations were
greater (P < .05) in obese than in lean pigs. The CCAAT/enhancer binding proteins
beta and alpha, adipocyte fatty acid binding protein, hormone-sensitive lipase,
and the beta1-adrenergic receptor transcript concentrations tended (P < . 10) to
be greater in adipose tissue from obese than in that from lean pigs. Several
other transcripts were numerically greater in obese than in lean pigs. The data
collectively suggest that messenger RNA concentration for several adipose tissue
proteins is a contributing factor to the excess fat deposition in these obese
pigs. Restricted feeding did not change the concentration of any transcript
except that for adipocyte fatty acid binding protein, which was reduced. The
accretion of fat was markedly reduced in the restrictively fed pigs, but this
diminution does not seem to be regulated by modulation of messenger RNA
concentration.
PMID- 10784184
TI - Developmental changes in cholesterol 7alpha- and 27-hydroxylases in the piglet.
AB - Hepatic cholesterol 7alpha-hydroxylase (CYP7A) and sterol 27 hydroxylase
activities were measured in fetal, newborn, suckling, and weaned piglets from 76
d into gestation to 49 d of age. Hepatic CYP7A activity was not detected in fetal
microsomes, but it increased to 6.8 +/- 2.6 pmol/min x mg(-1) protein in suckling
piglets at 21 d of age and to 18.2 +/- 2.5 in weaned piglets at 49 d of age.
Hepatic CYP7A activity was not different between 49-d-old piglets weaned at 21 d
and piglets suckled for 49 d (18.9 +/- 2.6 and 18.2 +/- 2.5 pmol/min x mg
protein, respectively). Fasting for 14 h decreased CYP7A activity by 86% in both
suckled and weaned piglets. Cholesterol 7alpha-hydroxylase activity remained
decreased for at least 5 h after refeeding. Sterol 27-hydroxylase activity was
also undetectable near birth, but was detectable by 21 d of age. Postnatally,
sterol 27-hydroxylase activity was not influenced by age or suckling and weaning,
as was CYP7A. Sterol 27-hydroxylase was decreased by 80% in piglets deprived of
feed compared with piglets given free access. In contrast to CYP7A activity, 27
hydroxylase activity returned within 5 h after refeeding to levels observed in
piglets given ad libitum access to feed. Similar to CYP7A enzyme activity,
hepatic CYP7A mRNA was not detected in newborn piglets, but increased from 2.7 +/
1.7 pg mRNA/microg RNA in suckling piglets at 21 d to 13.7 +/- 1.2 in 49-d-old
piglets weaned at 21 d. As with enzyme activity, feed deprivation decreased CYP7A
mRNA to barely detectable levels (< .5 pg/microg RNA), and which remained
decreased for at least 5 h following refeeding (.6 +/- .3 and 2.67 +/- .4 pg
mRNA/microg RNA for suckled and weaned piglets, respectively). In piglets allowed
free access to feed, CYP7A mRNA concentrations were associated positively (P =
.001) with enzyme activity. These results suggest that developmental regulation
of CYP7A activity is the result of a pretranslational mechanism.
PMID- 10784185
TI - Injection of beef strip loins with solutions containing sodium tripolyphosphate,
sodium lactate, and sodium chloride to enhance palatability.
AB - Beef strip loins (46 U.S. Choice loins and 49 U.S. Select loins) were used to
evaluate the potential for enhancing beef tenderness, juiciness, and flavor by
injecting fresh cuts with solutions containing sodium tripolyphosphate, sodium
lactate, and sodium chloride. One half of each loin served as an untreated
control, and the other half was injected with either distilled water (110% of raw
weight) or a solution containing phosphate/lactate/chloride solution (107.5, 110,
112.5, or 115% of raw weight). All phosphate/lactate/chloride solutions were
formulated to produce injected product concentrations of .25% sodium
tripolyphosphate, .5% sodium chloride, and 2.5% sodium lactate. Ten additional
U.S. Select loins were injected to 110% of raw weight with a phosphate-only
solution (final product concentration of .25% sodium tripolyphosphate) for
comparison with Select loins injected to 110% with phosphate/lactate/chloride and
with distilled water. Steaks from each control and treated loin section were
cooked to two final internal temperatures (66 degrees C and 77 degrees C) for
sensory panel evaluation and shear force measurement. Injection of subprimal cuts
with phosphate/lactate/chloride solutions improved tenderness (P < .05),
juiciness (P < .05), and cooked beef flavor (P < .10) of strip loin steaks and
was especially effective for maintaining tenderness and juiciness of steaks
cooked to the higher final internal temperature. Injection of Select loins with a
solution containing only sodium tripolyphosphate was not effective for improving
beef tenderness or juiciness and tended to impart off-flavors characterized by
sensory panelists as soapy and sour. Injection of fresh cuts with
phosphate/lactate/chloride solutions could assist the beef industry's efforts to
improve product quality and consistency.
PMID- 10784186
TI - Variation in proteolysis, sarcomere length, collagen content, and tenderness
among major pork muscles.
AB - The objectives of this experiment were to determine the extent of variation in
proteolysis, sarcomere length, and collagen content among pork muscles and the
association of those factors with tenderness variation among muscles at 1 d
postmortem. Twenty-three white composite barrows were slaughtered and carcasses
(66 kg) were chilled at 0 degrees C for 24 h. At 1 d postmortem, the longissimus
lumborum, biceps femoris, semimembranosus, semitendinosus, and triceps brachii,
long head were dissected from one side of each carcass and frozen. Trained
sensory panelists evaluated tenderness, amount of connective tissue, juiciness,
and pork flavor intensity of grilled (70 degrees C) chops on 8-point scales. Raw
chops were used for total collagen content, sarcomere length, and the extent of
desmin proteolysis. Tenderness ratings were highest (P < .05) for semitendinosus
(7.2) and triceps brachii (7.1), followed by longissimus lumborum (6.4) and
semimembranosus (5.7) and were lowest (P < .05) for biceps femorus (4.0). The
simple correlations between longissimus lumborum tenderness and the tenderness of
other muscles were .54 (semimembranosus), .34 (semitendinosus), .36 (triceps
branchii), and .17 (biceps femorus). Total collagen was highest (P < .05) for
biceps femorus (7.1 mg/g muscle), followed by triceps branchii (6.0 mg/g) and
semitendinosus (5.3 mg/g), and lowest for semimembranosus (4.5 mg/g) and
longissimus lumborum (4.1 mg/g). Sarcomere length was longest (P < .05) for
semitendinosus (2.5 microm) and triceps branchii (2.4 microm), followed by
semimembranosus (1.8 microm), longissimus lumborum (1.8 microm), and biceps
femorus (1.7 microm). Proteolysis of desmin was greatest (P < .05) in longissimus
lumborum (39.3%), followed by semimembranosus (21.0%) and biceps femoris (18.5%),
then semitendinosus (.2%) and triceps brachii (.2%). Multiple linear regression
using total collagen, sarcomere length, and proteolysis accounted for 57% of the
variation in tenderness rating among all samples. Piecewise linear regression was
used to account for the interaction of sarcomere length with proteolysis and
collagen. This analysis accounted for 72% of the variation in tenderness rating.
Variation in collagen, proteolysis, and sarcomere length and the degree of their
interaction with one another determine the tenderness of individual muscles.
PMID- 10784187
TI - Identification of optimal ranges in ribeye area for portion cutting of beef
steaks.
AB - Restaurant-ready (21-d aged, needle tenderized) loin steaks (strip, S; and T
bone, TB) representing three portion sizes (227, 284, and 340 g for S; 397, 454,
and 510 g for TB) were portioned from 71 low-Choice beef carcasses representing
seven ribeye size groups (70.9 cm2 and less to 103.2 cm2 and greater, in 6.3-cm2
increments). Steaks (n = 568) were cooked on a grooved grill to temperatures of
either 67 or 77 degrees C and evaluated for cooking characteristics, sensory
attributes (n = 284), and shear force (n = 284) to identify optimal ribeye areas
for portioned steaks. As expected, thickness of all portioned steaks decreased (P
< .05) as ribeye size increased, whereas thickness of steaks increased (P < .05)
as portion size increased. The S were significantly thicker than TB. The TB
cooked faster (P < .05) than did S for ribeye areas 77.4 to 83.8 cm2 in the
average portion sizes and for ribeye areas 71.0 to 96.6 cm2 in the large portion
sizes. However, S cooked significantly faster than did TB for ribeye areas less
than 70.9 cm2 in the average portion sizes. The S had higher (P < .05) initial
tenderness scores and lower (P < .05) shear values than did TB. Initial
tenderness scores were lower (P < .05) for ribeye areas greater than 103.2 cm2
compared with ribeye areas less than 83.8 cm2 and 90.3 to 96.6 cm2, with all
others being intermediate. Shear force tended (P = .08) to follow the initial
tenderness results. The S cooked to both end point temperatures, and TB cooked to
67 degrees C had higher (P < .05) initial tenderness scores than did TB cooked to
77 degrees C. Tenderness was reduced in TB cooked to higher temperatures as well
as in S and TB portioned from ribeye areas greater than 103.2 cm2. Steaks
portioned from carcasses with ribeye areas between 77.4 to 96.6 cm2 can optimize
both cooking time and tenderness for the foodservice sector.
PMID- 10784188
TI - Effect of dietary glycine and benzoate level on benzoate metabolism in mink
(Mustela vision), blue fox (Alopex lagopus), and raccoon dog (Nyctereutes
procyonoides).
AB - Three 2 x 4 factorial experiments were carried out from August to September with
30 juvenile male mink, 24 raccoon dogs, and 24 blue foxes to investigate the
effect of dietary glycine supply (low or high) on the efficiency of these species
to excrete hippuric acid with incremental benzoate intake (0, 1, 2, or 4 mmol/kg
BW). For mink, two additional treatments with 1 or 2 mmol/kg BW of ethyl benzoate
were included. A basal low-glycine diet was formulated to meet the minimum
protein requirements of fur animals (30% of ME). This diet was supplemented with
0 or 3 g/kg of glycine, or with 0, 1.0, 2.07, or 4.15 g/kg of sodium benzoate for
mink and blue foxes, and with 0 or 4.5 g/kg of glycine and 0, 1.58, 3.17, or 6.34
g/kg of sodium benzoate for raccoon dogs, respectively. Two additional diets with
.76 or 1.53 g/kg of ethyl benzoate were made for mink. Fecal and urinary benzoic
and hippuric acid excretion were measured for 3 d. The 24-h recovery of
[14C]benzoic acid injected intraperitoneally was measured from urine, the liver,
and the kidneys. All animals appeared healthy and no clinical signs of benzoate
overdose were observed. Dietary benzoate level did not affect ADFI or ADG in any
species. Glycine supplementation lowered ADFI in mink. The majority of ingested
benzoates were absorbed from the gut (over 95%), except in blue foxes, which
excreted 6 to 15% of ingested benzoates in feces with incremental increases in
benzoate intake. Urinary free benzoic acid excretion accounted for 10% of the
ingested benzoates in blue foxes but less than 5% in mink and raccoon dogs. When
benzoate intake was 1 mmol/kg BW, mink, blue foxes, and raccoon dogs excreted 71,
77, and 34% of ingested benzoates as hippuric acid in urine, respectively. With
higher benzoate intakes, urinary hippuric acid excretion decreased quadratically
with mink to 20%, and linearly with blue foxes and raccoon dogs to 45 and 16%,
respectively. The hippuric acid pathway appears to be the principal route of
benzoate elimination in the mink and blue fox, whereas, in the raccoon dog, other
pathways appear to be more important. In mink, the elimination of ethyl benzoate
did not differ from that of sodium benzoate. Because glycine conjugation is the
primary route of benzoate elimination, it is recommended that benzoate content in
fur animal feeds should not exceed 1 g/kg feed on an as-fed basis.
PMID- 10784189
TI - Further assessment of the dietary lysine requirement of finishing gilts.
AB - A cooperative research study involving 635 gilts was conducted at eight research
stations to further estimate the lysine requirement of finishing gilts. Dietary
crude protein levels of the five dietary treatments ranged from 16.0 to 24.4%
with calculated lysine levels of .80, .95, 1.10, 1.25, or 1.40%. Each station
contributed a minimum of two replicate pens of pigs per treatment. Average
initial and final weights were 53.6 and 116.4 kg, respectively. At the end of the
experimental period, pigs were killed and hot carcass weight, 10th-rib fat depth,
and longissimus muscle area were measured. Carcass fat-free lean percentage and
fat-free lean gain were estimated from these data. Daily lysine intakes averaged
21.8, 25.9, 30.5, 34.3, and 37.8 g/d for the five treatment groups, respectively.
Increasing the dietary lysine from .80 to .95% numerically increased weight gain
and gain:feed, but these increases were not maintained at higher levels of
dietary lysine. Overall, rate and efficiency of gain decreased (cubic, P < .01)
with increasing dietary lysine. Carcasses were leaner at the two higher levels of
dietary lysine as evidenced by reduced 10th rib backfat (linear, P < .01),
increased longissimus area (quadratic, P < .04), and increased percentage of
estimated fat-free lean (linear, P < .01). Carcass fat-free lean gain was not
influenced by dietary lysine except for a small numerical improvement (P < .11)
at the .95% level of dietary lysine that paralleled the improvement in body
weight gain. The results indicate that the dietary lysine requirement of
finishing gilts with a mean carcass fat-free lean growth rate of 306 g/d from 54
to 116 kg body weight is probably no higher than .80% of the diet to achieve
maximum rate and efficiency of body weight gain and carcass lean growth rate. The
results also indicate that higher dietary lysine levels may increase carcass
leanness in finishing gilts, possibly due to reduced intake of NE. Whether this
response is due to the effects of lysine alone, protein (i.e., other amino
acids), or soybean meal is unknown.
PMID- 10784190
TI - Impact of dietary lysine intake during lactation on follicular development and
oocyte maturation after weaning in primiparous sows.
AB - Primiparous sows (n = 36) were used to evaluate the effects of dietary lysine
intake in lactation on follicular development and oocyte maturation after
weaning. Sows were assigned randomly to one of three diets containing .4% (low
lysine, LL), 1.0% (medium lysine, ML), or 1.6% (high lysine, HL) total lysine.
All diets contained 2.1 Mcal NE/kg and exceeded NRC (1988) requirements for all
other nutrients. Actual lysine intakes over an 18-d lactation were 16, 36, and 56
g/d for sows consuming LL, ML, and HL, respectively. Ovarian data were analyzed
for sows determined to have been slaughtered during the first proestrus period
after weaning, using previously established criteria. Compared with sows fed ML
and HL, sows fed LL tended to have lower uterine weight, follicular fluid volume,
and follicular fluid (FF) estradiol (E2) content (P < .15), but similar ovarian
weight and follicular fluid IGF-I concentration. Within the largest 15
preovulatory follicles, sows fed LL had a lower percentage of large (> or = 7.0
mm) follicles (33 vs 50 and 58%; P < .01) and a higher percentage of medium (5.5
to 7.0 mm) follicles (62 vs 44 and 39%; P < .01) but a similar percentage of
small (< or = 5.5 mm) follicles (4.4 vs 5.9 and 3.7%; P > .15), respectively,
compared with sows fed ML or HL. Standardized pools of oocytes aspirated from
follicles of prepubertal gilts were incubated for 44 h with pooled FF recovered
from the largest 15 follicles of each experimental sow. Fewer oocyte nuclei
matured to metaphase II of meiosis when cultured with FF recovered from sows fed
LL, than from sows fed ML or HL (47.1 vs 59.8 and 63.8%, respectively; P < .01).
Our results suggest that low lysine (protein) intake in primiparous lactating
sows impaired follicular development and reduced the ability of follicles to
support oocyte maturation. However, high compared with medium lysine (protein)
intake had no further positive effects on ovarian function.
PMID- 10784191
TI - Effects of dietary lysine intake during lactation on blood metabolites, hormones,
and reproductive performance in primiparous sows.
AB - Effects of three dietary lysine (protein) concentrations during lactation on
metabolic state, protein metabolism, reproductive hormones, and performance were
investigated in 36 primiparous sows. Sows were assigned randomly to one of three
diets containing .4% (low lysine, LL), 1.0% (medium lysine, ML), or 1.6% (high
lysine, HL) total lysine from intact protein sources. All diets contained 2.1
Mcal NE/kg and exceeded the recommended requirements for all other nutrients.
Actual lysine intakes over an 18-d lactation were 16, 36, and 56 g/d for sows fed
LL, ML, and HL, respectively. Fractional breakdown rate of muscle was determined
on d 4 and 15 of lactation by using a three-compartment kinetic model of 3
methylhistidine metabolism. Increasing lysine intake during lactation did not
affect fractional breakdown rate of muscle on d 4 of lactation but decreased it
on d 15 (P < .05). Sows fed LL had a reduced number of LH pulses on d 12 and 18
(P < .05) and reduced serum estradiol (E2) concentration on d 18 of lactation
compared with sows fed ML and HL treatments. However, LH pulses and E2
concentrations were similar between ML and HL treatments (P > .35). Increasing
lysine intake increased serum urea nitrogen (SUN) and postprandial insulin
concentrations (P < .05) during lactation but had no effect on plasma glucose
concentrations (P > .20). Sows fed HL had greater serum IGF-I on d 6 and 18 than
sows fed ML (P < .05). Number of LH peaks was correlated with serum insulin
concentration 25 min after feeding on d 6 and 18 (r = .31 to .41; P < .1) and pre
(r = .33 to .46) and postprandial (r = .30 to .58) SUN concentrations (P < .05)
during different stages of lactation. Results indicate that, compared with medium
lysine intake, low lysine intake increased muscle protein degradation and
decreased concentrations of insulin, SUN, and estradiol and LH pulsatility. In
contrast, high lysine (protein) intake increased SUN, insulin, and IGF-I, but did
not increase secretion of estradiol and LH compared with medium lysine intake.
Furthermore, nutritional impacts on reproduction may be mediated in part through
associated effects on circulating insulin concentration.
PMID- 10784192
TI - Growth promotion effects and plasma changes from feeding high dietary
concentrations of zinc and copper to weanling pigs (regional study).
AB - An experiment was conducted to determine the effect of high dietary intakes of Zn
and Cu and their combination on growth performance of weanling pigs with diverse
health status and management strategies. Twelve experiment stations cooperated
and used a total of 1,356 pigs that averaged 6.55 kg BW and 22.2 d age at
weaning. The four dietary treatments, all of which met or exceeded NRC
requirements, were 1) control, 2) 3,000 ppm Zn (from Zn oxide), 3) 250 Cu ppm
(from Cu sulfate), or 4) 3,000 ppm Zn and 250 ppm Cu. The diets were fed as a
complex Phase I diet (1.4% lysine) for 7 d followed by a Phase II diet (1.2%
lysine) for 21 d. Chlortetracycline (220 ppm) was added to all diets. Fecal color
(1 = yellow to 5 = black) and consistency (1 = very firm to 5 = very watery) were
scored daily for 3 wk. At the end of the 28-d study, 412 pigs were bled at five
stations, and plasma Cu, Zn, and Fe concentrations were determined at one station
with atomic absorption spectrophotometry. Average daily gain (375, 422, 409, 415
g/d), feed intake (637, 690, 671, 681 g/d), and gain/feed (586, 611, 611, 612
g/kg) were improved (P < .01) by the addition of Zn and(or) Cu. Significant Cu x
Zn interactions imply that the responses to Zn and Cu were independent and not
additive. There were significant (P < .01) Zn and Cu effects and a Zn x Cu
interaction on fecal color (3.17, 3.24, 4.32, 3.57) and consistency (2.39, 2.14,
2.14, 2.13). Dietary additions of Cu and Zn resulted in elevated plasma
concentrations of Cu and Zn, respectively. These data indicate that
pharmacological additions of 3,000 ppm Zn (oxide) or 250 ppm Cu (sulfate)
stimulate growth beyond that derived from intakes of Zn and Cu that meet nutrient
requirements. However, the combination of Zn and Cu did not result in an additive
growth response.
PMID- 10784193
TI - Zinc bioavailability in soybean meal.
AB - A phytate-containing soy protein concentrate (SPC) diet (13.5 mg Zn/kg) and a
phytate-free egg white diet (.3 mg Zn/kg) were used to determine the relative
bioavailability (RBV) of Zn in dehulled soybean meal (SBM) based on Zn depletion
repletion growth bioassays in young chicks. After a 4-d Zn depletion period,
chick weight gain responded linearly (P < .01) to graded increments of
supplemental Zn (0 to 10 mg/kg) from ZnSO4 x 7H2O, whether added to the Zn
deficient SPC or egg white diet. Slope, however, was over twice as great for the
standard curve relating weight gain to supplemental Zn intake for the egg white
diet as for the SPC diet. Addition of 7 to 10 mg Zn/kg from SBM to either Zn
deficient diet increased (P < .01) weight gain, but a similar SBM addition to
either diet made adequate in Zn did not increase weight gain. Using standard
curve methodology, RBV of Zn in SBM was 78% when the the SPC diet was used, but
it was only 40% when the egg white diet was used. The phytate contained in the
SPC basal diet therefore markedly reduced the efficiency of utilizing the
supplemental inorganic Zn from ZnSO4 x 7H2O. This lowered the slope of the
standard curve so that, on a relative basis, the Zn in SBM had a higher RBV value
than was the case for Zn utilization in SBM with the phytate-free egg white diet.
The 78% Zn RBV value in SBM would seem to have the greatest relevance for
practical-type corn-SBM diets.
PMID- 10784194
TI - Ornithine alpha-ketoglutarate and creatine effects on growth and plasma
metabolites of nursery pigs.
AB - Four experiments were conducted to determine the effect of dietary ornithine
alpha-ketoglutarate (OKG) and creatine monohydrate on growth performance and
plasma metabolites of nursery pigs. In each experiment, treatments were
replicated with four to five pens of four to six pigs each. Each experiment
lasted from 3 to 4 wk and Phase I (1.6% Lys) and Phase II (1.3 to 1.5% Lys) diets
were fed for 9 to 16 d each. In Exp. 1, pigs (4.7 kg and 15 d of age) were fed
diets containing 0, .10, or .75% OKG. Daily gain during a 13-d Phase I period and
ADFI during Phase I and overall (29 d) were increased (P < .10) in pigs fed .75%
OKG. Gain:feed ratio was not affected (P > .10) by diet. In Exp. 2, pigs (7.1 kg
and 23 d of age) were fed 0 or .50% OKG during Phase I only. During Phase I, II,
and overall, ADG and ADFI were not affected (P > .10) by OKG supplementation, but
gain:feed was decreased during Phase I (P < .04), Phase II (P < .08), and overall
(P < .04). Plasma urea N (PUN), glucose, and NEFA concentrations were not
affected (P > .10) by OKG supplementation in this experiment. In Exp. 3, pigs
(5.8 kg and 20 d of age) were fed diets containing 0, .10, or .50% creatine.
Creatine tended to linearly decrease ADG (P = .11) and plasma albumin (P = .12)
and PUN (P < .10) concentrations in Phase II (d 12 to 26). In Exp. 4, 850 mg of
OKG or 750 mg of creatine was provided daily by oral capsule to pigs 4 d before
weaning to 2 d after weaning. Pigs within a litter received either no capsule or
capsules containing OKG or creatine. After weaning, pigs that received no capsule
before weaning received no treatment, .50% creatine, or .50% OKG in the nursery
diet. Pigs that received OKG before weaning received no treatment or .50% OKG,
and pigs that received creatine before weaning received no treatment or .50%
creatine in the nursery diet. Pigs weighed 3.9 kg 4 d before weaning and 4.9 kg
at weaning at an average age of 20 d. The OKG provided by capsule decreased ADG
(P < .02) and ADFI (P < .09) during Phase II. The OKG did not affect (P > .10)
plasma NEFA, glucose, or urea N concentrations. Creatine added to the nursery
diet increased (P < .02) ADFI and decreased (P < .10) gain:feed during Phase II
and overall. Creatine in the nursery diet also increased (P < .01) PUN, but it
did not affect plasma glucose or NEFA concentrations. Creatine and OKG have
variable effects on growth performance and plasma metabolites of nursery pigs.
PMID- 10784195
TI - Alterations in hemograms and serum biochemical analytes of steers after prolonged
consumption of endophyte-infected tall fescue.
AB - The objective of the current study was to delineate changes that occur in serum
analytes and blood cellular elements in cattle that graze endophyte-infested
(Neotyphodium coenophialum) tall fescue. Tall fescue is grown on more than 35
million acres (14.2 million ha) of pasture in the United States, and three
fourths of the pastures are infected with the endophyte at a 60% or greater
level. Tall fescue toxicosis caused by endophyte-produced ergot alkaloids
continues to be the most important grass-related disease in the United States, in
terms of economic loss to animal producers. However, the agronomic attributes of
tall fescue make it an attractive forage species because of its ability to
withstand cool temperatures, drought, poor soil conditions, and intensive
defoliation from herbivore species, including insects. Tall fescue toxicosis is a
complex disease and the need exists to understand the mechanisms of the toxic
effects in order to institute effective, prophylactic control measures. Our group
previously reported changes that occur in serum biochemical analytes of cattle
that graze endophyte-infected tall fescue. An additional year's worth of data
have been added, strengthening and corroborating these data. Consistent and
significant changes associated with tall fescue toxicosis during the 3-yr study
included decreased serum concentrations of cholesterol, globulin (increased
albumin/globulin ratio), prolactin, total protein, and copper. The activity of
alanine aminotransferase was decreased in serum, whereas an increase in serum
concentrations of creatinine and total bilirubin occurred. The present report
also documents comparative hemograms of cattle that grazed endophyte-infected or
endophyte-free tall fescue over a prolonged period. The mean erythrocyte counts
were increased in cattle that grazed endophyte-infected tall fescue, whereas mean
corpuscular hemoglobin and mean corpuscular volume were decreased, as were mean
eosinophil counts. Thus, repeatable changes have been identified that occur in
serum biochemical and blood cellular values of cattle grazing endophyte-infected
tall fescue that will aid in understanding the pathogenesis of the disease. In
addition, these consistently altered parameters can be used to assess the
effectiveness of potential prophylactic treatments.
PMID- 10784196
TI - Adrenal function in Angora goats: a comparative study of adrenal steroidogenesis
in Angora goats, Boer goats, and Merino sheep.
AB - South African Angora goats (Capra aegagrus) are susceptible to stress conditions,
possibly due to adrenal cortex malfunction. Selection for mohair production may
reduce adrenal function and decrease cortisol production. Secretion of cortisol
by the adrenal cortex is essential for the induction of several gluconeogenic
enzymes that enable animals to survive stressful conditions, and adrenocortical
insufficiency, therefore, precipitates a vulnerability to stress. In this study,
Angora goats were compared with two breeds generally accepted as hardy, Boer
goats (Capra hircus) and Merino sheep (Ovis aries). Adrenal steroidogenesis was
studied using subcellular fractions prepared from the adrenal glands of freshly
slaughtered animals. Adrenal microsomes and mitochondria were incubated with the
relevant steroid substrates, and products were analyzed and quantified with TLC,
HPLC, or RIA. Subsequently, the activity of individual enzymes involved in this
pathway were further investigated. The cytochrome P450 content in the
preparations was also compared. The results from these studies indicated that the
activity of the cytochrome P450c17 enzyme in Angora goats differed (P < .01) from
that of the other species investigated. This difference may contribute to the
cause of the observed hypoadrenocorticism in Angora goats.
PMID- 10784197
TI - Effect of estradiol-17beta administration during the time of conceptus elongation
on placental size at term in Meishan pigs.
AB - Meishan embryos transferred to recipient females on d 2.5 are larger, contain
greater numbers of trophectoderm cells, and secrete greater amounts of estradiol
17beta (E2beta) when gestated in a Yorkshire as compared with Meishan uterus to d
12. Additionally, placentas of Meishan conceptuses are larger when gestated in a
Yorkshire as compared with Meishan uterus throughout gestation. Embryonic E2beta
secretion during elongation on d 12 to 13 of gestation is temporally associated
with endometrial secretion of growth factors, including IGF-I, which has been
shown to increase mitotic rate in the trophectoderm of pig embryos. This
experiment was conducted to determine whether E2beta administration to Meishan
gilts at the time of conceptus elongation would increase placental size at term.
Meishan gilts (n = 12) were checked twice daily for estrus (0700 and 1900), and
each was bred to a Meishan boar at 0 and 24 h after the onset of estrus (d 0).
Gilts were randomly assigned in equal numbers to receive injections of sesame oil
(VEH) starting on d 12 (control), 1 mg of E2beta in VEH starting on d 12 (E212),
or 1 mg of E2beta in VEH starting d 13 (E(2)13). The injections were initiated at
0700 or 1900 (corresponding to the time of day they first exhibited estrus) and
continued at 6-h intervals for 48 h, resulting in 8 mg of E2beta given in eight
injections. Pregnant gilts were killed on d 112 of gestation, and ovulation rate,
litter size, implantation site length, fetal weight, crown-rump length, placental
weight, and placental surface area were quantified. There were no differences
among E(2)12, E(2)13, and control females in ovulation rate or litter size, which
averaged 16.3 +/- .7 and 11.8 +/- .7, respectively. Fetal weight and crown-rump
length were not different (P > .10) among E(2)12, E(2)13, and control females,
averaging 802 +/- 26 g and 24.3 +/- .3 cm. Placentas were markedly heavier (176
+/- 14 and 174 +/- 16 vs 134 +/- 10 g, P < .05) and larger (1,337 +/- 97 and
1,520 +/- 70 vs 978 +/- 29 cm2, P < .001) for E(2)12 and E(2)13 vs control gilts,
respectively. Placental efficiency (estimated as fetal weight:placental weight)
was greater (P < .05) in the control than in the E(2)12 and E(2)13 gilts (5.8 +/-
.2 vs 4.8 +/- .2 and 5.1 +/- .4). These data demonstrate that the amount of
E2beta exposure around the time of elongation affects placental size at term.
Additionally, the difference in placental efficiency between control and E2beta
groups indicate that E2beta-induced increases in placental size led to a reduced
placental efficiency.
PMID- 10784198
TI - Effects of dietary copper source and concentration on carcass characteristics and
lipid and cholesterol metabolism in growing and finishing steers.
AB - We conducted an experiment to determine the effects of dietary copper (Cu) source
and level on carcass characteristics, longissimus muscle fatty acid composition,
and serum and muscle cholesterol concentrations in steers. Sixty Angus and Angus
x Hereford steers were stratified by weight and initial liver Cu concentration
within a breed and randomly assigned to treatments. Treatments consisted of: 1)
control (no supplemental Cu); 2) 20 mg Cu/kg DM from Cu sulfate (CuSO4); 3) 40 mg
Cu/kg DM from CuSO4; 4) 20 mg Cu/kg DM from Cu citrate; 5) 20 mg Cu/kg DM from Cu
proteinate; and 6) 20 mg Cu/kg DM from tribasic Cu chloride. A corn silage
soybean meal-based diet was fed for 56 d. Steers were then switched to a high
concentrate diet. Equal numbers (n = 5) of steers per treatment were slaughtered
after receiving the finishing diets for either 101 or 121 d. Serum cholesterol
was not affected by treatment during the growing phase but was decreased (P <
.05) in steers supplemented with Cu by d 84 of the finishing period and remained
lower (P < . 05) at subsequent sampling periods. Longissimus muscle cholesterol
concentration tended to be reduced (P < .11) by Cu supplementation. Hot carcass
weight and backfat were lower (P < .05) in animals receiving supplemental Cu.
However, Cu-supplemented and control steers had similar marbling scores.
Longissimus muscle polyunsaturated fatty acid concentrations (18:2 and 18:3) were
increased (P < .07) and saturated fatty acid concentrations tended (P < . 11) to
be reduced by Cu supplementation. These results indicate that as little as 20 mg
of supplemental Cu/kg diet can reduce backfat and serum cholesterol and increase
muscle polyunsaturated fatty acids in steers fed high-concentrate diets.
PMID- 10784199
TI - Effect of dietary concentration of metabolizable lysine on finishing cattle
performance.
AB - A finishing trial and a metabolism trial were conducted to determine the effect
of supplemental metabolizable Lys level on finishing calf performance and to
estimate the metabolizable Lys requirement of finishing calves. The finishing
trial included 60 individually fed crossbred beef steer calves (237 kg; SD = 20
kg) supplemented with either incremental amounts of rumen-protected Lys and Met,
or Met alone. Addition of Lys and Met improved gains and efficiencies (quadratic;
P < .02) during the first 56 d. There was no response to supplemental Met alone,
suggesting that supplemental Lys rather than Met was responsible for the
improvement in performance. Using nonlinear analyses to compare gain relative to
supplemental Lys intake, maximum gain was determined to be 2.10 kg/d, or .27 kg/d
above the zero Lys control, at a supplemental Lys intake of 2.56 g/d. Steers
supplemented with 3 and 4 g of Lys had a weight advantage over the control steers
of 16 kg at 56 d and 32 kg at the end of the 161-d trial. However, there were no
statistical responses to Lys or Met during any periods after 56 d. During a
separate metabolism trial, four steers fed the control finishing diet were
slaughtered, and abomasal contents were collected for amino acid analyses. The
predicted (Level 1 NRC, 1996) metabolizable protein flow to the abomasum for the
control diet was 715 g/d, and the predicted Lys flow was 37.9 g/d. A supplemental
Lys intake of 2.56 g/d would increase the Lys flow to 40.5 g/d. Feedlot diets low
in ruminal escape protein may be deficient in metabolizable Lys, especially early
in the feeding period. The metabolizable Lys requirement of steer calves gaining
2.10 kg/d is estimated to be 40.5 g/d.
PMID- 10784200
TI - Influence of abomasal infusion of high levels of lysine or methionine, or both,
on ruminal fermentation, eating behavior, and performance of lactating dairy
cows.
AB - Four multiparous late-lactation Holstein cows were fed a basal ration designed to
be co-limiting in intestinally absorbable supplies of methionine and lysine. Cows
were supplemented with no amino acids, lysine by abomasal infusion to 140% of the
calculated intestinally absorbable requirement, methionine by abomasal infusion
to 140% of requirement, or both amino acids in a 4 x 4 Latin square design with
28-d periods. Unsupplemented cows consumed 23.8 kg/d of dry matter and produced
36.9 kg/d of milk containing 3.70% fat, 3.22% protein, and 4.82% lactose. Cows
ate less dry matter and produced less milk and milk lactose, and tended (P = .06
or .08) to produce less milk protein when abomasally infused with methionine
alone or together with lysine. Infusion of lysine alone resulted in production
values numerically between those of unsupplemented cows and those cows
supplemented with methionine alone or together with lysine. Evaluation of the
results with two metabolic models of dairy cows indicated that performance of
unsupplemented cows may have been limited by delivery of metabolizable or
digestible protein, or intestinally absorbable lysine, isoleucine, or histidine,
depending on the metabolic model used to evaluate animal performance. Regardless,
results are consistent with those using nonruminant species, which have shown
that imbalanced profiles of intestinally absorbable amino acids are associated
with reduced dry matter intake and animal performance. Results also show that
negative effects on performance of lactating dairy cows can occur if methionine
is supplied at levels substantially in excess of calculated intestinally
absorbable requirements, either alone or together with lysine.
PMID- 10784202
TI - The effect of feed intake level on splanchnic metabolism in growing beef steers.
AB - The effect of feed intake level (.6, 1.0, and 1.6 x maintenance energy and
protein requirements, M) on splanchnic (portal-drained viscera [PDV] plus liver)
metabolism was evaluated in six multicatheterized beef steers (398 +/- 27 kg),
using a double 3 x 3 Latin square design. On the last day of each 21-d
experimental period, six hourly blood samples were collected from arterial,
portal, and hepatic vessels. Due to catheter patency, PDV fluxes were measured on
five steers, and liver and splanchnic fluxes on four steers. Increasing intake
elevated (P < .01) splanchnic release of total (T) amino acids (AA), through
increases (P < .01) in PDV release of both essential (E) and nonessential (NE)
AA, in spite of a tendency (P < .20) for increased liver removal of NEAA. The PDV
release of AA N represented 27 and 51% of digested N for 1.0 and 1.6 x M,
respectively. At 1.0 and 1.6 x M, the liver removed 34% of total AA released by
the PDV. For individual AA, portal flux of most EAA increased (P < .05) with feed
intake, and the increase (P < .10) in splanchnic flux was accompanied by
increased arterial concentration for all EAA except histidine, lysine, and
methionine. This suggests that these might be limiting AA for this diet. On a net
basis, most individual NEAA were released by the PDV except glutamate and
glutamine, which were removed by the digestive tract. There was a net removal of
NEAA by the liver, except for aspartate and especially glutamate, which were
released. Ammonia release by the PDV tended (P < .20) to increase with intake and
represented 69, 53, and 45% of digested N at .6, 1.0, and 1.6 x M, respectively.
Urea removed by the PDV, unaffected by intake, represented 32, 33, and 21% of the
digested N. Arterial glucose concentration increased linearly (P < .01) with
greater intake, whereas net liver and splanchnic glucose release increased in a
quadratic (P < .05) manner. Net PDV glucose release represented 26% of net
glucose hepatic release at 1.6 x M. Intake elevated (P < .10) both insulin and
glucagon arterial concentrations, resulting from a larger increment of portal
release (P < .01) than hepatic removal (P < .05). Intake-based variations in IGF
I and NEFA arterial concentrations (P < .05) were not related to changes in
splanchnic metabolism. These results clearly show the crucial role of the
splanchnic tissues in regulating the profile and quantity of AA and
concentrations of glucose and pancreatic hormones reaching peripheral tissues.
PMID- 10784201
TI - Absorption of 2-hydroxy-4-(methylthio)butanoic acid by isolated sheep ruminal and
omasal epithelia.
AB - Alimet (Novus Inter., Inc., St. Louis, MO) feed supplement (an 88% aqueous
solution of 2-hydroxy-4-(methylthio) butanoic acid; HMB) is a source of L-Met
commonly used in nonruminants and ruminants. The absorption of HMB across ovine
omasal and ruminal epithelia was evaluated in this study. Ruminal and omasal
epithelia were collected from eight lambs (BW = 67.6 kg +/- 9.1) and mounted in
parabiotic chambers that were repeatedly sampled throughout a 60-min incubation.
The appearance of HMB (using DL-[5-14C]-HMB as a radiolabeled marker) in serosal
buffers increased quadratically (P < .004) with time in both tissues. More (P <
.001) HMB appeared in the serosal buffers with omasal than with ruminal
epithelia. Both tissues responded similarly, and, after 60 min of incubation, the
accumulation of HMB within the tissues increased linearly (P < .001) as substrate
concentration (.375, .75, 1.5, 3.0, 6.0, and 12.0 mM) increased in mucosal
buffers. As the concentration of HMB in the mucosal buffers increased, there was
a quadratic (P < .001) increase in the appearance of HMB in the serosal buffer of
the omasal epithelium, indicating some saturation of the system. The increase in
serosal appearance of HMB was linear (P < .001) with ruminal tissue. The results
indicate that there are probably multiple mechanisms involved in the absorption
of HMB. Because saturation was observed in the omasum, it is likely that mediated
transport accounts for at least a portion of the absorption of HMB in the omasum.
Other mechanisms (e.g., diffusion and(or) paracellular absorption) are
responsible for the balance of the absorption. Omasal epithelium appears to have
a greater capacity for HMB absorption than ruminal epithelium. The enzymes
involved in the conversion of HMB to 2-keto-4-(methylthio)butanoic acid were
found in ruminal and omasal epithelia, liver and kidney. These results indicate
that HMB can be absorbed across ruminal and omasal epithelium and that HMB can be
used as a source of L-methionine.
PMID- 10784203
TI - Rapid communication: polymorphism in the goat beta-lactoglobulin proximal
promoter region.
PMID- 10784204
TI - Assessing pediatric senior residents' training in resuscitation: fund of
knowledge, technical skills, and perception of confidence.
AB - OBJECTIVE: To describe pediatric housestaff knowledge, experience, confidence in
pediatric resuscitations and their ability to perform important resuscitation
procedures during the usual training experience. DESIGN AND PARTICIPANTS: Cohort
study of PGY-3 level residents in a ACGME accredited pediatric residency training
program at a large, tertiary care children's hospital. METHODS: Fund of knowledge
was assessed by administering the standardized test from the Pediatric Advanced
Life Support (PALS) Course in addition to a supplemental short answer test
requiring clinical problem-solving skills. Procedural skills were evaluated
through observation of the resident performing four procedures during a skills
workshop using a weighted step-wise grading sheet. Resident experience and
confidence was quantified using an anonymous survey. RESULTS: Ninety-seven
percent of residents participated. Residents achieved high scores on the
standardized PALS test (93.2%+/-5.5), but performed less well when answering more
complicated questions (60.0%+/-9.9) on the short answer test. No resident was
able to successfully perform both basic and advanced airway skills, and only 11%
successfully completed both vascular skills. Although residents were overall
confident in their resuscitation skills, performance in the skill workshop
revealed significant deficits. For example, only 18% performed ancillary airway
maneuvers properly. None of the residents performed all four skills correctly.
Experience in both real and mock resuscitations was infrequent. Residents
reported receiving feedback on their performance less than half of the time. Over
89% of them felt that resuscitation knowledge and skill were important for their
future chosen career. CONCLUSION: Pediatric residents infrequently lead or
participate in real or mock resuscitations. Although confident in performing many
of the necessary resuscitation skills, few residents performed critical
components of these skills correctly. Current pediatric residency training may
not provide sufficient experience to develop adequate skills, fund of knowledge,
or confidence needed for resuscitation.
PMID- 10784205
TI - Fall and suffocation injuries associated with in-home use of car seats and baby
carriers.
AB - OBJECTIVE: This paper examines two hazard patterns associated with in-home use
and placement of car seats and baby carriers: 1) fall injuries resulting from
placement on elevated surfaces and 2) suffocation resulting from seat overturn on
soft surfaces. DESIGN: Emergency department data reporting on falls suffered by
infants aged 6 months and younger, and associated with car seats and baby
carriers, were provided by the U.S. Consumer Product Safety Commission's National
Electronic Injury Surveillance System for 1997. National estimates were based on
396 incidents. Additionally, 15 cases of suffocation resulting from car/infant
seat overturn on soft surfaces were identified through the Commission's Death
Certificate and Investigation Files. RESULTS: In 1997, it is estimated that
approximately 8700 infants were treated in emergency departments as a result of
fall injuries suffered while using a car seat or baby carrier. More than one
third of estimated falls were specifically attributed to the seat being placed on
an elevated surface in the home, such as a counter or table. A search of
suffocation incidents resulting from seat overturn on a soft surface produced 15
incidents. The majority of incidents occurred when the seat had been placed on a
bed or waterbed. CONCLUSIONS: Many parents are unaware of hazards associated with
common placement scenarios for infant car seats and baby carriers. These hazard
patterns and their potential consequences need to be conveyed to new parents by
pediatricians. At the same time, manufacturers have an obligation to pursue
design alternatives that will reduce the likelihood of seat overturn.
PMID- 10784206
TI - Costs of sedation using oral midazolam: money, time, and parental attitudes.
AB - OBJECTIVE: Many agents suitable for pediatric outpatient sedation have been
identified and compared, but less data have appeared on the effect of sedation
use on Emergency Department (ED) length of stay (LOS) or visit costs. We sought
to discover the relationship between one commonly used method of sedation, orally
administered midazolam, and ED LOS and visit costs. Parents were then surveyed to
determine their attitudes toward sedation given knowledge of these costs.
METHODS: All ED patients under 10 years of age seen in a pediatric ED during
April and May of 1996 for repair of lacerations <2.5 cm in length were identified
via retrospective chart review. Children were excluded if they had other
significant injuries, received sedatives other than oral midazolam, or were
repaired by non-ED physicians. Preliminary cost and LOS data from this review was
used to create a parental survey measuring attitudes toward the costs of an
unnamed form of sedation (not mentioning oral midazolam). A convenience sample of
parents in an ED waiting room were asked if they would want sedation administered
to a child needing sutures if this increased the visit cost by $100 and/or
increased LOS by 30 minutes. Parents were then asked to re-answer these questions
assuming that the sedation medication was effective only 50% of the time.
RESULTS: Of 120 patients meeting entry criteria, 57 (48%) received oral
midazolam. Children sedated with this agent were significantly younger (3.6 vs.
4.6 years, P = 0.015), had more layered repairs (30% vs. 14%, P = 0.047), and
more facial lacerations (84% vs. 63%, P = 0.01) when compared with nonsedated
patients. Mean LOS for patients with simple lacerations receiving oral midazolam
increased by 17.1 minutes (P = 0.03) compared with nonsedated children; for
layered repairs, the mean increase was 30.9 minutes (P<0.05). The use of oral
midazolam did not effect physician charges, but did significantly increase mean
combined nurse/hospital charges and total charges by 73 to 87 dollars, depending
on laceration type (P<0.001 all cases). Of 81 parents surveyed, 81% said that
they would be willing to wait 30 extra minutes for sedation to be used; this
figure fell to 73% if sedation was effective 50% of the time. Seventy-five
percent of parents were willing to pay $100 extra for sedation; 67% if sedation
was effective only half the time. Willingness to endure a longer LOS or pay
increased charges was not associated with parental sex or insurance status.
CONCLUSION: The use of oral midazolam significantly increases ED visit LOS and
cost. This information is important to review with parents when discussing
sedation options. Up to one third of parents surveyed would not want to wait
extra time or pay extra money for sedation to be administered, especially if the
efficacy of the chosen method was not assured.
PMID- 10784207
TI - Acceptance of family member presence during pediatric resuscitations in the
emergency department: effects of personal experience.
AB - OBJECTIVE: Opinions remain polarized on allowing family member presence during
pediatric resuscitations (FMP). Reluctance to adopt FMP may stem from
preconceived notions on this practice. This study evaluates the effect of prior
experience with FMP and on its acceptance by emergency department personnel
(EDP). METHODS: EDP from three different EDs were surveyed concerning FMP. Study
facilities included an urban teaching community ED with routine FMP (R-ED), a
suburban community ED with occasional FMP (O-ED) and an urban university
pediatric ED with virtually no FMP (N-ED) during pediatric resuscitations. Survey
information included hospital of practice, position in ED, years in practice,
opinions on FMP and personal experience with FMP for five clinical scenarios:
laceration repair (LAC), intravenous access (IV), lumbar puncture (LP),
endotracheal intubation (ETI), cardiopulmonary resuscitation (CPR), and critical
resuscitation (CR). Statistical analysis was through chi square and regression
analysis. RESULTS: Eighty-five emergency department personnel participated in the
survey, 57 (67%) nurses, 22 (25%) physicians, 4 technicians (5%), and 2 nurses
aids (2%). There was a significant correlation between a favorable opinion
concerning family member presence during LP, ETI, CPR and CR and the type of
Emergency Department in which the individual practiced (P<0.002). Regression
analysis demonstrated a similar relation between personal experience with LAC,
IV, ETI, CR, and CPR and a favorable opinion on FMP during that activity
(P<0.03). CONCLUSION: Opinions on FMP are strongly influenced by experience with
this practice. Emergency department personnel with prior exposure to family
member presence during resuscitations favor this activity. Biases by EDP lacking
experience with FMP may limit its introduction into unfamiliar institutions.
PMID- 10784208
TI - A comparison of the initial to the later stream urine in children catheterized to
evaluate for a urinary tract infection.
AB - BACKGROUND: To avoid potential contamination, it is recommended that the first
few drops of urine be discarded when obtaining a catheterized urine sample from a
child being evaluated for a urinary tract infection (UTI). The existing evidence
to make such a recommendation is scant. Our goal, therefore, was to determine
whether the urinalysis, Gram stain, and culture results were significantly
different from the initial and later urine samples collected from catheterized
children. METHODS: A prospective diagnostic discrimination between early and
later urine samples was conducted on a convenience sample of pediatric patients
being evaluated for a UTI in an urban emergency department. Results of the
urinalysis, Gram stain, and quantitative culture were compared between the early
and later stream urine samples. RESULTS: Data from 86 children were analyzed.
Four of 80 patients had a false identification of low colony count bacteruria
from the early but not from the later stream. For patients with negative
cultures, the early stream was also more likely to falsely identify > or =5
wbc/hpf (P<0.01) or bacteruria (P<0.05) on urinalysis than the later stream.
CONCLUSIONS: There is a small but potentially meaningful contamination of the
early stream urine compared with the later stream in young children catheterized
to evaluate for a urinary tract infection.
PMID- 10784209
TI - Lower thoracic SCIWORA in a 3-year-old child: case report.
PMID- 10784211
TI - Central anticholinergic syndrome from orphenadrine in a 3 year old.
AB - Orphenadrine (N,N-dimethyl-2(o-methyl-alpha-phenylbenzyloxy)ethylamine) is an
analog of diphenhydramine with central and peripheral anticholinergic properties.
It is commonly prescribed both as a muscle relaxant and as an adjunct to
antipsychotic medications to prevent parkinsonism. We report a case of
orphenadrine poisoning in a 3-year-old boy following ingestion of no more than
two 100-mg tablets. Central anticholinergic toxicity was prominent, manifested by
hallucinations and severe agitation. Orphenadrine can cause profound toxicity in
children after ingestion of small doses, and should be considered as a potential
cause for acute delirium in childhood.
PMID- 10784210
TI - A common cause of altered mental status occurring at an uncommon age.
AB - Wernicke's encephalopathy is a neurologic disorder due to a nutritional
deficiency of thiamine, characterized by ocular palsies, ataxia, and altered
mental activity. While Wernicke's encephalopathy is commonly attributed to
alcoholism in the adult population, it has been described in children receiving
prolonged parenteral nutrition and those with malignancies and AIDS. The disease,
however, is rarely diagnosed in the pediatric population during life. We report a
case of Wernicke's encephalopathy in a child with prolonged starvation and aim to
improve awareness of a potentially fatal but treatable disease.
PMID- 10784212
TI - Hallucinations as the initial presentation of shigellosis.
PMID- 10784213
TI - Brain abscess following delayed endoscopic removal of an initially asymptomatic
esophageal coin.
AB - Brain abscesses are rare occurrences in pediatric patients, and making their
diagnosis can be difficult. The two most commonly cited risk factors are
otorhinologic infections and cyanotic congenital heart disease (CCHD). We present
a 13-month-old child with a brain abscess who, 2 weeks prior, underwent rigid
endoscopy for the extraction of a coin from the esophagus. We believe this to be
the first such report of a brain abscess after rigid endoscopy for removal of an
esophageal foreign body. In this case the esophageal coin was initially
asymptomatic and had been present for weeks prior to removal. The potential
association between delayed coin extraction and development of an intracranial
infection, suggested by this report, may warrant investigation.
PMID- 10784214
TI - Abdominal trauma in infants and children: prompt identification and early
management of serious and life-threatening injuries. Part I: injury patterns and
initial assessment.
AB - Evaluation of children with abdominal trauma can be a difficult process. Unique
anatomic features predispose children to specific injuries and potentially make
identification of life-threatening injuries difficult. While Part I of this
review discusses the initial assessment and diagnostic testing in children with
abdominal trauma, Part II will review specific injuries and ED management of
children with possible abdominal trauma. Knowledge of each of these factors will
improve the ability of general and pediatric emergency physicians to
expeditiously identify children with potential serious injury and initiate
appropriate treatment.
PMID- 10784215
TI - Pediatric emergency medicine: legal briefs.
PMID- 10784216
TI - Left back pain and blood in the urine.
PMID- 10784217
TI - Evaluation of an ambu-bag valve with a self-contained, colorimetric end-tidal CO2
system in the detection of airway mishaps: an animal trial.
AB - OBJECTIVE: Capno-Flo (Kirk Specialty Systems, Carrouton, TX) is a portable
pulmonary resuscitator (self inflating ambu-bag--valve system) with a self
contained, colorimetric end-tidal CO2 detector that has the ability to provide
continuous CO2 monitoring for up to 2 hours. The purpose of this study is to
determine the accuracy and time interval for the Capno-Flo monitor to detect
acute airway obstructions and hypopharyngeal extubations in an intubated animal
model. SUBJECTS: Five anesthetized, non-paralyzed, mechanically ventilated
Yorkshire minipigs. METHODS: Complete and partial airway obstruction was
simulated with complete and partial cross-clamping of the endotracheal (ET) tube.
Placement of the ET tube into the hypopharynx was performed to simulate
accidental extubation. In addition to the Capno-Flo colorimetric indicator, both
sidestream (SS) and mainstream (MS) capnography were used to monitor end-tidal
CO2 and comparison. The time intervals for the capnograph wave to flatten and for
the monitor to display "zero" were recorded after each airway alteration. Each
experiment was carried out for 180 seconds, and a total of 25 trials was
performed. RESULTS: Complete obstruction produced a color change in the Capno-Flo
monitor in 9+/-2 seconds and flattening of the SS and MS waveform in 8+/-2
seconds and 6+/-2 seconds, respectively. The SS and MS monitors displayed zero in
49+/-7 seconds and 19+/-1 seconds, respectively. Partial obstruction did not
produce color change, a flattening of the wave, or a monitor display of zero.
Hypopharyngeal extubation produced a color change in 10+/-2 seconds, flattening
of the SS and MS waveform in 7+/-2 seconds and 7+/-1 seconds, respectively. The
SS and MS monitors displayed "zero" in 76+/-16 seconds and 18+/-3 seconds,
respectively. CONCLUSION: The Capno-Flo identified all complete airway
obstructions and hypopharyngeal extubations rapidly. The CF monitor performed
comparable to the SS and MS capnographs. Neither the Capno-Flo, nor the
sidestream, nor the mainstream capnographs detected partial airway obstruction.
The clinical application of this portable inexpensive capnometer in the
continuous monitoring of the intubated patient, especially the transport patient,
should be investigated further.
PMID- 10784218
TI - An 18 month old with recurrent otitis media.
PMID- 10784219
TI - Is it or isn't it?
PMID- 10784220
TI - Radicals and oxidative stress in diabetes.
AB - Recent evidence is reviewed indicating increased oxidative damage in Type 1 and
Type 2 diabetes mellitus as well as deficits in antioxidant defence enzymes and
vitamins. Mechanisms are considered whereby hyperglycaemia can increase oxidative
stress, and change the redox potential of glutathione and whereby reactive oxygen
species can cause hyperglycaemia. It is argued that oxygen, antioxidant defences,
and cellular redox status should now be regarded as central players in diabetes
and the metabolic syndrome.
PMID- 10784221
TI - Beneficial effects of C-peptide on incipient nephropathy and neuropathy in
patients with Type 1 diabetes mellitus.
AB - AIMS: Recent studies have indicated that proinsulin C-peptide shows specific
binding to cell membrane binding sites and may exert biological effects when
administered to patients with Type 1 diabetes mellitus. This study was undertaken
to determine if combined treatment with C-peptide and insulin might reduce the
level of microalbuminuria in patients with Type 1 diabetes and incipient
nephropathy. METHODS: Twenty-one normotensive patients with microalbuminuria were
studied for 6 months in a double-blind, randomized, cross-over design. The
patients received s.c. injections of either human C-peptide (600 nmol/24 h) or
placebo plus their regular insulin regimen for 3 months. RESULTS: Glycaemic
control improved slightly during the study and to a similar extent in both
treatment groups. Blood pressure was unaltered throughout the study. During the C
peptide treatment period, urinary albumin excretion decreased progressively on
average from 58 microg/min (basal) to 34 microg/min (3 months, P < 0.01) and it
tended to increase, but not significantly so, during the placebo period. The
difference between the two treatment periods was statistically significant (P <
0.01). In the 12 patients with signs of autonomic neuropathy prior to the study,
respiratory heart rate variability increased by 21 +/- 9% (P < 0.05) during
treatment with C-peptide but was unaltered during placebo. Thermal thresholds
were significantly improved during C-peptide treatment in comparison to placebo
(n = 6, P < 0.05). CONCLUSION: These results indicate that combined treatment
with C-peptide and insulin for 3 months may improve renal function by diminishing
urinary albumin excretion and ameliorate autonomic and sensory nerve dysfunction
in patients with Type 1 diabetes mellitus.
PMID- 10784222
TI - Education integrated into structured general practice care for Type 2 diabetic
patients results in sustained improvement of disease knowledge and self-care.
AB - AIMS: The objective of this study was to study the effectiveness of structured
care with and without integrated education with regard to patients' knowledge,
self-care behaviour and disease perception. METHODS: Four diabetes care
programmes implemented in a daily primary care setting were compared, two based
on structured care and two on education integrated into structured care.
Measurements were taken at baseline and after 6 and 12 months. RESULTS: The study
included 243 patients with Type 2 diabetes mellitus treated by a general
practitioner (mean age 64.0 years; diabetes duration 7.1 years). The level of
patients' disease knowledge increased in all programmes, was preserved at follow
up and differed between programmes with a specific educational component (37%) on
one hand and the non-educational programmes (11%) on the other (P < 0.001). The
percentage of patients performing self-care behaviour increased in all
programmes, but more so in the programmes with an educational component. In
addition, an increase in the frequency of self-care behaviour was observed,
whereas no change in disease perception was found. In cross sectional analyses
disease knowledge and self-care behaviour were positively related (partial
correlation coefficient: 0.35; P < 0.001 adjusted for age, sex, level of
education and duration of diabetes). CONCLUSIONS: The results indicate that
primary care programmes which integrated education into structured care are able
to improve both Type 2 diabetic patients' disease knowledge and their self-care
behaviour. These improvements endured after the completion of the programmes,
which suggests that they initiate lasting changes in the way patients handle
their disease.
PMID- 10784223
TI - Prevalence of symptoms of depression and anxiety in a diabetes clinic population.
AB - AIMS: To investigate the use of a short questionnaire to measure psychological
symptoms in a busy clinic setting, and to examine the prevalence of these
symptoms in adults with diabetes. The perceived need for psychological treatment
services was also measured. METHODS: Adults (> 18 years) with either Type 1 or
Type 2 diabetes were invited to complete a short demographic form and the
Hospital Anxiety and Depression Scale (HADS) whilst waiting for their routine
diabetes outpatients appointment. Complication status was measured via patients'
medical records. Glycaemic control (HbA(1c)) was also recorded. RESULTS: A high
response rate (96%) was achieved. Prevalence rates of psychological symptoms were
high (overall 28% of study participants reported moderate-severe levels of
depression or anxiety or both). Men were somewhat more likely to report moderate
severe depressive symptoms, whereas women reported more moderate-severe anxiety.
A significant association between depression and poor glycaemic control was
observed in the men, but not in the women. Regression analysis demonstrated that
the interaction between sex and glycaemic control, HbA(1c) and sex were all
significantly associated with depression and anxiety (R2 = 0.16 and 0.19,
respectively). One-third of subjects reported that at the moment they would be
interested in receiving counselling or psychotherapy if it was currently
available at the diabetes clinic. CONCLUSIONS: This study has shown that the HADS
is an appropriate questionnaire to use in a clinic setting in adults with
diabetes. There may be a stronger association between glycaemic control and
psychological symptomatology in men than in women. There remains a significant
proportion of individuals with diabetes who require psychological support, which,
if available, might help improve glycaemic control and thus overall wellbeing.
PMID- 10784224
TI - Is mild gestational hyperglycaemia associated with maternal and neonatal
complications? The Diagest Study.
AB - AIMS: To evaluate the maternal and neonatal complications rates of mild
gestational hyperglycaemia (MGH) compared to a control group in France. METHODS:
A systematic screening by a 50-g glucose challenge test was offered to all women
between 24 and 28 weeks of gestation in 15 maternity units. If the 50-g glucose
challenge test was > or = 7.2 mmol/l, a 100-g 3-h oral glucose tolerance test
(OGTT) was performed. MGH (n = 131) was defined by one abnormal value on the 3-h
OGTT (Carpenter and Coustan criteria). The control group (n = 108) was defined by
a 50-g glucose challenge test below 7.2 mmol/l. Women with MGH received no
treatment or specific advice during the pregnancy. Large for gestational age
(LGA) was defined by a birth weight of at least the 90th percentile on French
standard growth curves. RESULTS: Women with MGH were older than the controls
(28.8 (5.8) vs. 27.0 (5.2); P < 0.05) and had a higher body mass index (24.8
(4.8) vs. 23.0 (3.9); P < 0.01). The rate of pregnancy-induced hypertension and
Caesarean section were not different between the MGH and control group. The rate
of LGA was significantly higher in the MGH group than the control group (22.1%
vs. 11.4%; P < 0.05). After adjustment for confounding factors of macrosomia (pre
pregnancy body mass index > 27, maternal age > 35, multiparity and educational
level), there was a persistent relationship between LGA and MGH (odds ratio 2.50;
95% confidence interval (1.16-5.40); P < 0.05). MGH was more frequently
associated with adverse maternal and fetal outcome than in the controls (53.4%
vs. 28.7%; P < 0.01). CONCLUSIONS: This study suggested that the increased rate
of adverse maternal and fetal outcome, especially LGA, was associated with
untreated mild gestational hyperglycaemia women compared to a control group. This
link to lower degrees of hyperglycaemia during pregnancy is independent of
confounding factors.
PMID- 10784225
TI - A randomized, controlled trial comparing insulin lispro with human soluble
insulin in patients with Type 1 diabetes on intensified insulin therapy. The UK
Trial Group.
AB - AIMS: Despite considerable experience with insulin lispro, few blinded
comparisons with soluble insulin are available. This study compared insulin
lispro with human soluble insulin in patients with Type 1 diabetes mellitus on
multiple injection therapy who inject shortly before meals. METHODS: Glucose
control, frequency of hypoglycaemia and patient preference were examined in the
course of a prospective, randomized, double-blind, crossover comparison, with a 6
week run-in period and 12 weeks on each therapy. Ninety-three patients took part,
all on multiple daily doses of insulin, with soluble insulin before meals and NPH
(isophane) insulin at night. The main outcome measures were self-monitored blood
glucose profiles, glycated haemoglobin, frequency of hypoglycaemic episodes,
patient satisfaction and well-being and patient preference. RESULTS: Blood
glucose levels were significantly lower after breakfast and lunch, but higher
before breakfast, lunch and supper, in patients taking insulin lispro. Levels of
HbA(1c) were 7.4 +/- 1.1% on Humulin S and 7.5 +/- 1.1% on insulin lispro (P =
0.807). The overall frequency of symptomatic hypoglycaemia did not differ, but
patients on insulin lispro were less likely to experience hypoglycaemia between
midnight and 6 a.m., and more likely to experience episodes from 6 a.m. to
midday. Questionnaires completed by 84/87 patients at the end of the study showed
that 43 (51%) were able to identify each insulin correctly, nine (11%) were
incorrect, and 32 (38%) were unable to tell the insulins apart. No significant
preference emerged: 35 (42%) opted for insulin lispro, 24 (29%) opted for Humulin
S, while the remainder had no clear preference. CONCLUSIONS: Substitution of
insulin lispro for soluble insulin in a multiple injection regimen improved post
prandial glucose control at the expense of an increase in fasting and pre
prandial glucose levels. Patients who already injected shortly before meals
expressed no clear preference for the fast-acting analogue, and did not improve
their overall control as a result of using it. Nocturnal hypoglycaemia was
however, less frequent on insulin lispro, and may emerge as a robust indication
for its use.
PMID- 10784226
TI - Clinical profile of diabetic foot infections in south India--a retrospective
study.
AB - AIMS: The aim of the study was to determine the profile of diabetes foot
infections in south Indian diabetic subjects. The causative factors for delayed
wound healing and the recurrence of infection were also studied. METHODS: During
a period of 6 months, 374 patients who had undergone some surgical procedure for
foot infection were available for follow-up (M:F 227:147, mean age 54.9 +/- 9.4
years, diabetes duration 10.9 +/- 7.7 years). All of them had records of clinical
and treatment details, laboratory data including biothesiometry, Doppler tests
and electrocardiogram (ECG) records. Foot ulcers were classified according to
Wagner's classification. RESULTS: Majority of the patients had grade II and III
ulcers (50% and 26.5%, respectively), grade IV was seen in another 21.9%. The
median healing time was 44 days. Recurrence of infection which occurred in 53%
was more common in patients with neuropathy and peripheral vascular disease
(PVD). CONCLUSIONS: Recurrence of foot infection was common among south Indian
Type 2 diabetic subjects and was related to the presence of PVD and neuropathy.
There is also a need for improvement in footwear and foot care education.
PMID- 10784227
TI - Angiotensin-converting enzyme inhibition by quinapril blocks the albuminuric
effect of atrial natriuretic peptide in Type 1 diabetes and microalbuminuria.
AB - AIMS: This study examined the effect of angiotensin-converting enzyme inhibition,
administered at doses with no effect on systemic blood pressure, on the
albuminuric action of atrial natriuretic peptide (ANP). METHODS: Seven Type 1
diabetic patients with established microalbuminuria participated in a two limb,
single-blind, placebo controlled study. Subjects were administered quinapril 10
mg daily or placebo for 7 days prior to study. On the study day, subjects were
euglycaemic clamped and subsequently fluid loaded (20 ml/kg tap water orally plus
urinary losses). At steady state diuresis, a 1 h intravenous infusion of ANP 0.05
mg.kg(-1) x min(-1) was administered. Urine was collected at 15-min intervals for
estimation of albumin-creatinine ratio (ACR). Results were analysed by ANOVA.
RESULTS: Baseline mean arterial pressure was similar after pre-treatment with
quinapril and placebo (98.7 +/- 3.8 vs. 100 +/- 4.5 mmHg, mean +/- SD, P > 0.5),
and was unaltered by ANP infusion on either study day. Baseline ACR was similar
on quinapril and placebo (P = 0.13). ANP infusion induced a rise in urine ACR
with placebo (58.4 +/- 40.2 to 393.6 +/- 262.9 mg/mmol, P = 0.006), but not with
quinapril (29.3 +/- 10.7 to 81.5 +/- 43 mg/mmol, P = 0.15). The urine ACR
response to ANP infusion was higher with placebo than with quinapril (P = 0.02).
CONCLUSIONS: Quinapril blocks the albuminuric effect of intravenous infusion of
ANP in subjects with Type 1 diabetes mellitus and established microalbuminuria.
This action is independent of changes in mean arterial pressure and creatinine
clearance.
PMID- 10784228
TI - Effects of the new oral hypoglycaemic agent nateglinide on insulin secretion in
Type 2 diabetes mellitus.
AB - AIMS: The new non-sulphonylurea oral hypoglycaemic agent nateglinide has been
shown to enhance insulin secretion in animals and in healthy human volunteers and
thus offers a potential advance in the treatment of Type 2 diabetes mellitus.
This study examined whether nateglinide can enhance insulin secretion, and
particularly the first phase insulin response, in patients with Type 2 diabetes.
METHODS: A double-blind, placebo-controlled trial, examining the effects of a
single oral dose of 60 mg nateglinide, given 20 min prior to an intravenous
glucose tolerance test (IGTT), on insulin secretion in 10 otherwise healthy
Caucasian men with recently diagnosed Type 2 diabetes (duration since diagnosis 0
44 months). RESULTS: Insulin secretion (both overall and first phase) was
significantly increased by nateglinide (P < 0.001), as were C-peptide (P < 0.001)
and proinsulin (P < 0.001) secretion. Overall glucose concentrations following
glucose challenge were lower after nateglinide than after placebo (P = 0.05).
CONCLUSIONS: Nateglinide significantly increases insulin secretion in Type 2
diabetic patients, in particular restoring the first phase insulin response.
Further study is necessary to determine the effects of chronic administration on
insulin secretion and blood glucose concentration.
PMID- 10784229
TI - Relative activity and referral patterns for diabetes and non-diabetes in general
practice.
AB - AIMS: To describe and compare general practice (GP) activity for patients with
and without diabetes using a survey of general practices representing over 10% of
the Welsh population. METHODS: The Welsh GP Morbidity Database Project (GPMDP)
collected data including demographic and lifestyle information and consultation
data such as diagnosis, referral and surgical procedures. These data were
analysed to establish the annual period prevalence of diabetes and compare the
relative number of consultations and referrals. RESULTS: A total of 4,182
diabetic patients were recorded (prevalence 1.41%) and accounted for 77,371
(4.4%) consultations. Patients with diabetes were four-times more likely to be
referred to community services (relative risk (RR) 4.1, 95% CI 3.7-4.7), in
particular district nursing (RR 3.8, 1.9-7.7), optician services (RR 8.9, 5.0
15.7), chiropody (RR 8.2 6.4-10.5) and dietician services (RR 21.2, 17.6-25.5).
Patients with diabetes were also more likely to be followed-up in general
practice (RR 6.7, 6.2-7.2) both within 1 month (RR 6.7, 6.2-7.2) and 1 month to 1
year (RR 9.7, 8.9-10.7). Emergency admissions were also more likely for patients
with diabetes (RR 6.8, 6.2-7.5) as were elective admissions to general medicine
(RR 5.6, 4.6-6.7), surgery (RR 1.8, 1.5-2.0) and opthalmology (4.2, 3.4-5.2).
CONCLUSION: The increased utilization of health services apparent in secondary
care was confirmed in primary care. Further research is required to determine
levels of community activity after initial referral.
PMID- 10784230
TI - Early social mixing and childhood Type 1 diabetes mellitus: a case-control study
in Yorkshire, UK.
AB - AIMS: Evidence from animal models shows an increased risk of Type 1 diabetes
mellitus associated with the absence of early life exposure to pathogens. To test
this 'hygiene hypothesis', patterns of social mixing and infections in the first
year of life and the risk of developing autoimmune diabetes in childhood were
examined. METHODS: Personal interviews were conducted with the mothers of 220
children with Type 1 diabetes (0-15 years) and 433 age/sex matched controls from
a population-based case control study in Yorkshire, UK. Social mixing including
attendance at daycare, and infections occurring under 1 year of age were measures
of exposure. Adjusted odds ratios (OR) were derived using conditional logistic
regression. RESULTS: Frequency of attendance at daycare during the 1st year of
life was inversely associated with childhood diabetes (OR 0.71, 95% confidence
interval 0.51-1.00, P = 0.05), a finding not explained by mother's age, level of
education or maternal diabetes. Increasing numbers of children in the daycare
setting and numbers of sessions attended were significantly associated with
increasing protection from diabetes. The strongest effect was observed in
children with diabetes diagnosed aged 0-4 years. CONCLUSIONS: Social mixing
through attendance at daycare in early infancy appears to confer protection
against the development of childhood diabetes. This may be mediated through
exposure to infectious agent(s) as a significant dose-response effect was evident
with increasing numbers of child 'contacts'. These findings suggest early
infectious exposure may play a role in the development of immunoregulatory
mechanisms which protect against diabetes and further work is warranted.
PMID- 10784231
TI - Comparison of vasodilator effects of substance P in human forearm vessels of
normoalbuminuric Type 1 diabetic and non-diabetic subjects.
AB - AIMS: To compare the vasodilatory responses to substance P in human forearm
vessels in Type 1 normoalbuminuric diabetic and non-diabetic subjects. METHODS:
Forearm blood flow (FBF) was measured using a plethysmography technique in 12
normoalbuminuric Type 1 diabetic subjects (six males, six females) (HbA(1c) 8.2
+/- 0.3% (mean +/- SEM)) and 12 non-diabetic healthy control subjects in response
to the infusion of the vasodilators substance P (SP), acetylcholine (ACh) and
nitroprusside. RESULTS: There was no significant difference in baseline FBF
between the two groups (2.80 +/- 0.29 ml/min per 100 ml forearm tissue (diabetic
group) vs. 2.85 +/- 0.37 ml/min per 100 ml (non-diabetic group), P = 0.45).
Infusion of SP was associated with an incremental increase in FBF in the diabetic
(0.6, 2 and 6 ng/min - 6.08 +/- 1.07, 7.82 +/- 1.08 and 9.48 +/- 1.14 ml/min per
100 ml, respectively) and the non-diabetic group (0.6, 2 and 6 ng/min - 5.41 +/-
0.80, 6.93 +/- 0.96 and 9.25 +/- 1.11 ml/min per 100 ml, respectively).
Similarly, an incremental rise in FBF was observed during infusion of ACh
(diabetic group: 7.5, 15 and 30 microg/min - 7.14 +/- 1.22, 8.91 +/- 1.40 and
11.67 +/- 1.93 ml/min per 100 ml, respectively; non-diabetic group: 7.5, 15 and
30 microg/min - 5.87 +/- 0.81, 7.49 +/- 0.96 and 10.74 +/- 1.29 ml/min per 100
ml, respectively). When FBF was expressed as percentage change from baseline,
there was no significant difference in vasodilatory responses between the two
groups for SP (0.6 ng/min, P = 0.21; 2 ng/min, P = 0.19; 6 ng/min, P = 0.19) or
ACh (7.5 microg/min, P = 0.20; 15 microg/min, P = 0.20; 30 microg/min, P = 0.35).
CONCLUSIONS: This study suggests that endothelium-dependent vasodilatory
responses to SP (and ACh) are not impaired in Type 1 diabetic subjects with
normal urinary albumin excretion.
PMID- 10784232
TI - Significance of GAD positivity in elderly patients with diabetes.
PMID- 10784233
TI - Hypoxia-induced vascular endothelial growth factor expression is potentiated by
elevated glucose levels.
PMID- 10784234
TI - Does acute hyperinsulinaemia change plasma adrenomedullin concentration in
healthy men?
PMID- 10784235
TI - Long-term treatment of the anaemia in Type 1 diabetes mellitus with
erythropoietin.
PMID- 10784236
TI - Epidemiology, racism, and health: the case of low birth weight.
PMID- 10784237
TI - Impact of exposure to maternal PCBs and dioxins on the neonate's thyroid hormone
status.
PMID- 10784238
TI - Birth weight trends among interracial black and white infants.
AB - I examined time trends in low birth weight (LBW) and very low birth weight (VLBW)
among interracial compared with single-race infants. Using natality data from
1978 through 1997 for singleton births to black and white parents, I calculated
relative risks (RRs) of LBW and VLBW for interracial compared with single-race
births, stratified by maternal race and adjusted for maternal characteristics.
Among black mothers, interracial births had lower risks of LBW and VLBW than
single-race births, and RRs were similar throughout the time period [for example,
adjusted RR = 0.76 and 95% confidence interval (CI) = 0.73-0.80 for LBW in 1994
1997]. Among white mothers, interracial infants had higher risks of LBW than
single-race infants; however, the adjusted RRs declined over the time period,
from 1.22 (95% CI = 1.19-1.27) in 1978-1981 to 1.05 (95% CI = 1.03-1.08) in 1994
1997. Since 1978, there has been some relative improvement in birth outcomes for
infants of white mothers and black fathers compared with single-race white
births. There was, however, no relative improvement for black mother/black father
infants relative to black mother/white father births.
PMID- 10784239
TI - Polychlorinated biphenyl (PCB) exposure in relation to thyroid hormone levels in
neonates.
AB - Polychlorinated biphenyls (PCBs) are industrially produced environmentally
persistent compounds. In developed countries all humans have detectable levels in
blood and other tissues. PCBs alter thyroid hormone metabolism in animal
experiments, and human data suggest background-level exposure may have similar
effects in neonates. We evaluated this possible effect among 160 North Carolina
children whose in utero PCB exposure was estimated on the basis of the mother's
PCB levels in milk and blood, in 1978-1982 (estimated median PCB level in milk at
birth, 1.8 mg/kg lipid). Their umbilical cord sera were thawed in 1998 and
assayed for total thyroxine, free thyroxine, and thyroid stimulating hormone. We
found that PCB exposure was not strongly related to any of the thyroid measures.
For example, for a one unit change in milk PCB concentration (mg/kg lipid), the
associated multivariate-adjusted increase in thyroid stimulating hormone level
was 7% (95% confidence limits (CL) = -6, 21). Despite the possibility of sample
degradation, these data suggest that within the range of background-level
exposure in the United States, in utero PCB exposure is only slightly related to
serum concentration of total thyroxine, free thyroxine, and thyroid stimulating
hormone at birth.
PMID- 10784240
TI - An exact method for meta-analysis of case-control and follow-up studies.
AB - In this paper, we describe an exact method for estimating a common relative risk
across different epidemiologic study designs. The types of studies allowed by the
method include case-control studies, follow-up studies with an internal
comparison group, and follow-up studies with an external comparison group.
Because the method is exact, sparseness of individual studies is not an issue.
Those wishing to perform a meta-analysis of case-control studies and follow-up
studies in which both the exposure and outcome are rare will find the method
particularly useful. To allow one to perform the computations efficiently, we
present a partial polynomial multiplication algorithm. We also describe a public
domain computer program that performs the necessary calculations.
PMID- 10784241
TI - Eosinophilia is associated with increased all-cause mortality after a follow-up
of 30 years in a general population sample.
AB - We investigated whether allergy is associated with increased all-cause mortality.
Two allergy markers, peripheral blood eosinophilia (> or =275 eosinophilic cells
per mm3) and positive skin tests (sum score > or =3), were available for 5,383
subjects of a cohort study on asthma and chronic obstructive pulmonary disease in
general population samples of Vlagtwedde and Vlaardingen, the Netherlands, in
1965-1972. During 30 years of follow-up, 1,135 subjects died. In a Cox regression
analysis, eosinophilia was associated with an increased risk (relative risk =
1.4; 95% confidence interval = 1.2-1.7) of all-cause mortality, independent of
gender, age, smoking habits, percentage predicted forced expiratory volume in 1
second (FEV1 % predicted), and positive skin tests at the start of the study.
Subjects with positive skin tests had only an increased risk of all-cause
mortality in the subgroup of subjects with FEV1 <80% of predicted (relative risk
= 1.7; 95% confidence interval = 1.0-2.8). These results remained essentially
unchanged after exclusion of subjects with asthma. We conclude that eosinophilia
is associated with increased all-cause mortality. An increased number of
peripheral blood eosinophils may reflect an increased inflammatory response,
resulting in tissue injury. It is possible that the association between a low
FEV1% predicted and all-cause mortality is partly mediated by an atopic
constitution.
PMID- 10784242
TI - Can sustained weight loss in overweight individuals reduce the risk of diabetes
mellitus?
AB - Although rates of adult-onset diabetes mellitus increase with increasing obesity,
there is little evidence that weight loss in overweight individuals can reduce
their risk of developing diabetes. Using data from the Framingham Study, we
examined the effects of sustained and nonsustained weight loss on risk of
diabetes mellitus among 618 overweight (body mass index > or =27) subjects 30-50
years of age. To separate sustained from nonsustained weight loss, we examined
weight change in two consecutive 8-year periods. Subjects who had stable weight
(+/- 1 lb per year) during both periods served as the referent group for all
analyses. Sustained weight loss led to a 37% lower risk of diabetes [relative
risk (RR) = 0.63; 95% confidence interval = 0.34-1.2], and this effect was
stronger for more obese (body mass index > or =29) subjects (RR = 0.38; 95%
confidence interval = 0.18-0.81). Those who lost 8.1-15 lb had a 33% reduction in
diabetes risk, whereas those losing more had a 51% reduction in risk. Regardless
of the amount of weight lost, those who regained the lost weight had no reduction
in diabetes risk (RR = 1.1 and 1.2 for those who lost 8.1-15 and >15 lb,
respectively). We conclude that a modest amount of sustained weight loss can
substantially reduce the risk of diabetes mellitus in overweight individuals.
PMID- 10784243
TI - An indirect estimate of the incidence of non-insulin-dependent diabetes mellitus.
AB - Our goal was to estimate non-insulin-dependent diabetes mellitus incidence in the
Netherlands in the absence of equivocal empirical data. Incidence can be
expressed as a function of age, sex, prevalence, and mortality. We obtained
prevalence data from a study that pooled existing prevalence estimates. We
calculated diabetes-related mortality using relative risks on all-cause
mortality. Sensitivity for the rate of excess mortality was determined using the
95% confidence intervals (95% CI) of the relative risks. The estimated incidence
increases exponentially with age, with a doubling time of 10 years for men and 9
years for women. The rate increases from 8.1 per 10,000 (95% CI = 7.7-8.8) for
men ages 40-44 years and 7.0 (95% CI = 6.8-8.0) for women to 79.7 per 10,000 (95%
CI = 69.5-90.9) for men ages 75-79 years and 85.8 (95% CI = 80.6-91.0) for women.
When empirical estimates of incidence are largely lacking, the methodology
described offers a useful alternative, in particular for the assessment of
potential intervention effects.
PMID- 10784244
TI - Influence of apolipoprotein E genotype on the risk of cognitive deterioration in
moderate drinkers and smokers.
AB - We investigated the risk of cognitive deterioration in relation to alcohol
consumption and smoking according to the apolipoprotein E (ApoE) polymorphism.
The ApoE epsilon4 allele is an established risk factor for dementia and cognitive
impairment. There are also some recent indications that vascular risk factors,
including alcohol and tobacco consumption, might play a role in cognition. Our
data are from the Epidemiology of Vascular Aging (EVA) study, a prospective study
of 1,389 subjects ages 59-71 years at study entry, living the city of Nantes,
France, and followed at 4 years after entry. Information on subjects' alcohol and
tobacco consumption was collected from a structured questionnaire on food habits.
Cognitive performance was assessed by the Mini-Mental State Examination (MMSE).
Cognitive deterioration was defined as a decrease of 3 points or more in the Mini
Mental State Examination between study entry and 4-year follow-up. Drinking was
associated with a decreased risk of cognitive deterioration in non-ApoE epsilon4
carriers, whereas an opposite association was observed in ApoE epsilon4 carriers.
The risk of cognitive deterioration associated with tobacco consumption was also
modified according to ApoE genotype, with smokers being at decreased risk of
cognitive deterioration among ApoE epsilon4 allele carriers and at increased risk
in noncarriers. The effects of alcohol consumption and smoking on the risk of
cognitive deterioration appears to be strongly modified by the presence of ApoE
epsilon4 allele.
PMID- 10784246
TI - Physical activity and incidence of postmenopausal breast cancer.
AB - Whether physical activity reduces the risk of postmenopausal breast cancer is
uncertain; few studies have addressed this issue. We examined the association of
leisure physical activity with breast cancer incidence among 37,105
postmenopausal participants in the Iowa Women's Health Study. Women reporting the
highest level of physical activity at baseline compared with women with the
lowest level of activity had an age-adjusted relative risk of breast cancer of
0.92 (95% confidence interval = 0.80-1.05). Women reporting any regular leisure
time physical activity had a relative risk of 0.97 (95% confidence interval =
0.87-1.08) compared with those reporting no such regular physical activity.
Adjustment for potential confounders did not appreciably alter the findings.
There is little evidence from this study that physical activity later in life is
associated to any appreciable extent with breast cancer incidence.
PMID- 10784245
TI - Smoking and myelodysplastic syndromes.
AB - The purpose of this case-control study was to investigate tobacco smoking as a
risk factor for myelodysplastic syndromes, emphasizing karyotypic aberrations as
markers for exposure and risk differentiation with respect to morphology. We
obtained smoking history by interview of 330 cytogenetically investigated adult
myelodysplastic syndrome cases and 337 controls, matched with respect to sex,
year of birth, and county of living. Smoking for at least 1 year at some time 20
years or less before diagnosis was associated with an elevated relative risk (RR)
for primary myelodysplastic syndromes (odds ratio (OR) 1.8; 95% confidence
interval (CI) = 1.2-2.7). The results indicated a relation with intensity and
duration of smoking as well as a decrease in risk a few years after cessation of
smoking. Smoking was associated with an increased RR for primary myelodysplastic
syndromes with chromosome 7 abnormalities (OR 5.0; 95% CI = 1.1-23). Elevated RRs
were also seen for refractory anemia (OR 2.5; 95% CI = 1.2-5.6) and for
refractory anemia with ringed sideroblasts (OR 3.2; 95% CI = 0.88-12). The
findings suggest that smoking is a risk factor for myelodysplastic syndromes.
PMID- 10784247
TI - Does hereditary nonpolyposis colorectal cancer explain the observed excess risk
of colorectal cancer associated with family history?
AB - Several studies have found an increased risk of colorectal cancer associated with
a family history of colorectal cancer. Some studies, although not all, have also
suggested that family history of colorectal cancer may be a risk factor for
adenomatous polyps. Hereditary nonpolyposis colorectal cancer is a known genetic
syndrome predisposing to colorectal cancer. The hypothesis of this paper is that
the preponderance of the genetic or familial risk for colorectal cancer in the
United States is mediated by hereditary nonpolyposis colorectal cancer. To test
this hypothesis, I have incorporated what is known about hereditary nonpolyposis
colorectal cancer into a genetic model that generates probabilities of family
clustering of colorectal cancer. Using this model, which assumes that all
familial risk for colorectal cancer is due to hereditary nonpolyposis colorectal
cancer, the expected relative risks for colorectal cancer (and adenomas)
associated with given types of family histories were calculated. The relative
risks predicted by the model fairly closely matched the results found in the
literature, especially those reported from a large cohort study. As observed in
several studies, the model predicts that relative risks decrease sharply with
age. In contrast to the elevated risk for colorectal cancer, the model predicts
no elevated risk for adenomas associated with family history of colorectal
cancer.
PMID- 10784248
TI - Age at menopause, body mass index, and the risk of colorectal cancer mortality in
the Dutch Diagnostisch Onderzoek Mammacarcinoom (DOM) cohort.
AB - We investigated whether age at menopause is associated with subsequent mortality
from colorectal cancer along with the possible modification of this association
by body mass index. Our data are from the Diagnostisch Onderzoek Mammacarcinoom
cohort of 10,671 postmenopausal women in the Netherlands, enrolled between 1974
and 1977, with a median follow-up of 18 years. During this follow-up, 95 women
died of colorectal cancer. Women 49 years of age or older at menopause showed a
lower risk of colorectal cancer mortality compared with women younger than 49 at
menopause. This protective effect, however, was found only among nonoverweight
women (< or =24 kg/m2), for whom the hazard ratio was 0.46 (95% confidence
interval = 0.21-1.03). In larger women, the hazard ratio was 1.17 (95% confidence
interval = 0.68-2.00).
PMID- 10784249
TI - Familial relationships in squamous cell carcinoma of the skin.
AB - The Swedish Family-Cancer Database, which was updated in 1999 to cover
individuals born after 1934 with their biological parents, totals 9.6 million
persons. We used this resource to study invasive and in situ skin cancers. We
identified 198 families in which a parent and an offspring had skin cancer. The
familial standardized incidence ratios (SIRs) were 2.4 for invasive and 2.8 for
in situ skin cancers in offspring. The SIRs for offspring depended only weakly on
the age at diagnosis, as evaluated in two age groups. Compared with offspring
whose parents had a single skin cancer, offspring whose parents had multiple skin
cancers had a 70% increase in SIR. The discordant parental cancer sites that
showed associations with skin cancer in offspring were melanoma, ocular melanoma,
and a group of cancers observed in immunosuppressed patients.
PMID- 10784250
TI - Maternal pregnancy estriol levels in relation to anamnestic and fetal
anthropometric data.
AB - In epidemiologic studies of perinatal exposures, birth weight has been proposed
as a proxy variable for intrauterine estrogen exposure. To assess the validity of
this assumption, we performed analyses of the association between estriol levels
in 188 women in the 17th, 25th, 33rd, and 37th weeks of pregnancy and the birth
weights of their infants. We found a general increase in mean cumulative estriol
dose with increasing birth weight category throughout pregnancy. In late
pregnancy, mean pregnancy estriol level of mothers of infants in the highest
birth weight category (>4,500 gm) was twice as high as that of mothers of infants
in the lowest category (<2,500 gm), 775 nmol/liter and 392 nmol/liter,
respectively. Smoking lowered the maternal estriol levels by 20% or more
throughout pregnancy. With smoking and birth weight included in a regression
analysis, maternal age, placental weight, and infant ponderal index did not add
any explanatory power to the model. Our data suggest that, on an aggregate level,
birth weight can be used as a proxy variable of intrauterine estriol exposure.
PMID- 10784251
TI - The distributed lag between air pollution and daily deaths.
AB - Many studies have reported associations between air pollution and daily deaths.
Those studies have not consistently specified the lag between exposure and
response, although most have found associations that persisted for more than 1
day. A systematic approach to specifying the lag association would allow better
comparison across sites and give insight into the nature of the relation. To
examine this question, I fit unconstrained and constrained distributed lag
relations to the association between daily deaths of persons 65 years of age and
older with PM10 in 10 U.S. cities (New Haven, Birmingham, Pittsburgh, Canton,
Detroit, Chicago, Minneapolis, Colorado Springs, Spokane, and Seattle) that had
daily monitoring for PM10. After control for temperature, humidity, barometric
pressure, day of the week, and seasonal patterns, I found evidence in each city
that the effect of a single day's exposure to PM10 was manifested across several
days. Averaging over the 10 cities, the overall effect of an increase in exposure
of 10 microg/m3 on a single day was a 1.4% increase in deaths (95% confidence
intervals (CI) = 1.15-1.68) using a quadratic distributed lag model, and a 1.3%
increase (95% CI = 1.04-1.56) using an unconstrained distributed lag model. In
contrast, constraining the model to assume the effect all occurs in one day
resulted in an estimate of only 0.65% (95% CI = 0.49-0.81), indicating that this
constraint leads to a substantial underestimate of effect. Combining the
estimated effect at each day's lag across the 10 cities showed that the effect
was spread over several days and did not reach zero until 5 days after the
exposure. Given the distribution of sensitivities likely in the general
population, this result is biologically plausible. I also found a protective
effect of barometric pressure in all 10 locations.
PMID- 10784252
TI - Total but not high-density lipoprotein cholesterol is consistently associated
with coronary heart disease mortality in elderly men in Finland, Italy, and The
Netherlands.
AB - We studied the relation between serum total and high-density lipoprotein (HDL)
cholesterol and 10-year coronary heart disease mortality in elderly men in
different European countries. The Finland, Italy and the Netherlands Elderly
(FINE) Study is a prospective follow-up study in 2,132 elderly men ages 65-84
years in Finland, the Netherlands, and Italy. We estimated relative risks using
Cox proportional hazard analysis with time-dependent covariates. Total
cholesterol was positively related to coronary heart disease mortality in all
three countries. The combined relative risk for the total population of the FINE
Study was 1.17 (95% confidence interval = 1.06-1.29) for each 1.00 mmol/liter
increase in total cholesterol. HDL cholesterol was inversely related to coronary
heart disease mortality in Finland, but not in the Netherlands and Italy. In
Italy we noted an interaction among HDL cholesterol, body mass index, and alcohol
intake, with an inverse association for HDL cholesterol in lean men who drank <40
gm of alcohol daily and a positive association for HDL cholesterol among
overweight men who drank > or =40 gm of alcohol per day. Serum total cholesterol
remains an important predictor of coronary heart disease mortality in elderly men
in different European countries. The effect of HDL cholesterol differed among the
three countries.
PMID- 10784253
TI - Body mass index in relation to energy intake and expenditure among adults in
Greece.
AB - The empirical evidence concerning the quantitative relations between energy
intake and expenditure on the one hand and body mass index (BMI) on the other is
inconclusive. We have used a large database of 14,281 individuals, for whom
habitual dietary intake and expenditure have been ascertained with adequate
methodology, to examine the mutually adjusted associations of these variables
with BMI. Study subjects were adult participants in the Greek component of the
European Prospective Investigation into Cancer and Nutrition (EPIC) study. After
adjustment for age and gender and exclusion of dieting individuals and energy
underreporters, an increment of about 500 kcal intake was found to correspond to
an increment of about 0.33 kg/m2 of BMI, whereas an increment of about 5 MET
hours of energy expenditure was associated with a decrease of about 0.18 kg/m2 of
BMI, where MET is the ratio of the metabolic rate associated with a given
activity to the resting metabolic rate. Our results indicate that increasing
physical activity is about half as effective as decreasing energy intake in
reducing BMI.
PMID- 10784254
TI - Low-income African-American mothers' perception of exposure to racial
discrimination and infant birth weight.
AB - We performed a hospital-based case-control study of African-American mothers to
explore the relation between a mother's perception of exposure to racial
discrimination during pregnancy and very low birth weight. We administered a
structured questionnaire to low-income mothers of very low birth weight (<1500
gm; N = 25) and non-low birth weight (>2500 gm; N = 60) infants. The unadjusted
and adjusted odds ratio of very low birth weight for maternal exposure to racial
discrimination were 1.9 (0.5-6.6) and 3.2 (0.9-11.3), respectively. We conclude
that maternal perception of exposure to racial discrimination during pregnancy
may be associated with very low birth weight in their infants.
PMID- 10784255
TI - Strength and anthropometric measures in identical and fraternal twins: no
evidence of masculinization of females with male co-twins.
AB - Sharing of intrauterine environment in twins of opposite sex has been
hypothesized to result in masculinization of the female twin. We tested this
hypothesis by comparing strength (maximum hand-grip pressure) and various
anthropometric measures in a newly established survey panel comprising 4,314
middle-aged twins identified through a Danish population-based twin registry. Sex
and zygosity-specific mean values of handgrip strength, height, weight, body
mass index, and waist circumference were highly comparable between fraternal
twins of opposite sex and fraternal twins of same sex. Our results provide no
support for the hypothesis of masculinization of female twins from opposite sex
twin pairs.
PMID- 10784256
TI - Differential survival related to smoking among patients with renal cell
carcinoma.
AB - We examined the relation between tobacco smoking and survival among renal cell
carcinoma cases, using information from a population-based cancer registry.
Current smokers were at increased risk of death compared with non-smokers (hazard
ratio (HR) 1.7, 95% CI = 1.2-2.5). The association was strongest within 6 months
of diagnosis (HR 2.5, 95% CI = 1.5-4.3). Most of the association was explained by
stage at diagnosis, with current smokers more likely (OR 2.2, 95% CI = 1.4-3.5)
to have distant disease. Case-control studies may be biased if cases who do not
participate owing to short survival have different smoking histories than
participating cases.
PMID- 10784257
TI - Cancer in husbands of cervical cancer patients.
AB - We used the Swedish Family-Cancer Database to analyze the spectrum of cancers
diagnosed in husbands of women with in situ or invasive cervical cancer, and we
compared these to second carcinogenic events in women presenting with these
cancers. Our hypothesis was increased cancer susceptibility from human papilloma
virus (HPV). When the wives had in situ or invasive cervical cancer, the standard
incidence ratios (SIRs) for anal cancer in husbands were 1.75 (95% CI = 1.05
2.62) and 1.92 (95% CI = 0.69-3.76). Anal cancer was also increased as a second
primary cancer in women. Other common cancers were related to tobacco smoking.
The results indicate that HPV infection is associated with anal cancer in both
men and women.
PMID- 10784258
TI - Using nicotine measurements and parental reports to assess indoor air: the PIAMA
birth cohort study. Prevention and Incidence of Asthma and Mite Allergy.
AB - We used two methods to collect data on indoor smoking exposure of 3-month-old
infants. First, parents of approximately 100 children completed a questionnaire.
We then measured nicotine in the air of the living rooms in smoking and non
smoking households with a passive sampler for a period of 2 weeks, several months
after the questionnaire had been completed. Smoking habits reported in the
questionnaire generally with reported number of cigarettes smoked during the
measurement weeks, and with nicotine concentrations in the air. These results
suggest that exposure classification based on questionnaire data is likely to be
reasonably valid.
PMID- 10784259
TI - The relative merits of contemporary measurements and historical calculated fields
in the Swedish childhood cancer study.
AB - We present arguments that suggest that historical average calculated fields,
which are widely used to estimate biologically relevant exposure to
electromagnetic fields, may be less accurate than contemporary spot measurements,
which are made at a time following the biologically relevant period of exposure.
We use data from the seminal Feychting and Ahlbom study of the health effects of
electromagnetic field exposure in a Swedish population to illustrate our
argument. We also show how the two types of measurements can produce divergent
estimates of risk, and show how in the Feychting and Ahlbom study, the less
accurate measurement, the historical average calculated fields, may have resulted
in a spurious increase in the estimates of risk. Finally, we consider the
implications of our arguments for other studies that rely on wire codes and
historical calculations of personal exposure.
PMID- 10784260
TI - Measuring electromagnetic fields.
PMID- 10784261
TI - Failure to publish results of epidemiologic studies is unethical.
PMID- 10784262
TI - Hepatitis B vaccine is not associated with liver problems in US children less
than 6 years old.
PMID- 10784263
TI - Hepatitis B vaccine is not associated with liver problems in US children less
than 6 years old.
PMID- 10784264
TI - Under-reporting of attributable risk and reporting of the risk ratio in
epidemiologic literature.
PMID- 10784265
TI - The role of atmospheric nitrogen dioxide in the risk of hospital admission in the
patient with respiratory pathology.
PMID- 10784266
TI - Common measures of disease burden, risk trade-offs, and improved environmental
health decision-making.
PMID- 10784268
TI - Diseases of meaning and the meaning of dis-eases.
PMID- 10784267
TI - A review of the benefits, adverse events, drug interactions, and safety of St.
John's Wort (Hypericum perforatum): the implications with regard to the
regulation of herbal medicines.
PMID- 10784269
TI - Searching for antimalarials in plants.
PMID- 10784270
TI - Homeopathic treatment of acute childhood diarrhea: results from a clinical trial
in Nepal.
AB - OBJECTIVE: To investigate whether the finding in a previous study that
homeopathic medicines decrease the duration of acute diarrhea in children could
be replicated in a different study population. DESIGN: Randomized, double-blind,
placebo-controlled trial. SETTING: Private, charitable health clinic in
Kathmandu, Nepal. SUBJECTS: A consecutive sample of 126 children, 6 months to 5
years of age, who presented during April through June, 1994, with more than three
unformed stools in the previous 24 hours. INTERVENTION: Children received either
an individualized homeopathic medicine or placebo, to be taken one dose after
each unformed stool for 5 days. Parents recorded daily stools on diary cards, and
health workers made home visits daily to monitor children. OUTCOME MEASURES:
Predefined measures were based on the previous study: (1) duration of diarrhea,
defined as the time until there were fewer than three unformed stools per day,
for two consecutive days, and (2) Average number of stools per day for each
group. RESULTS: Of the 126 children initially enrolled, 116 completed treatment.
The mean number of stools per day over the entire 5-day treatment period was 3.2
for the treatment group and 4.5 for the placebo group (P = 0.023). A Kaplan-Meier
survival analysis of the duration of diarrhea, which included data from all
patient visits, showed an 18.4% greater probability that a child would be free of
diarrhea by day 5 under homeopathic treatment (P = 0.036). CONCLUSIONS: These
results are consistent with the finding from the previous study that
individualized homeopathic treatment decreases the duration of diarrhea and
number of stools in children with acute childhood diarrhea.
PMID- 10784271
TI - An investigation into the use of aromatherapy in intrapartum midwifery practice.
AB - OBJECTIVE: The principal aim of the study was to examine the contribution of
aromatherapy to the promotion of maternal comfort during labor and as a tool to
improve the quality of midwifery care. DESIGN: Evaluative study. SETTING:
Delivery suite in a large British teaching hospital with approximately 6,500
deliveries per annum. SUBJECTS: A total of 8,058 mothers were evaluated between
1990 and 1998. INTERVENTIONS: Women were offered aromatherapy to relieve anxiety,
pain, nausea and/or vomiting or to strengthen contractions. Routine data
collected on the use of aromatherapy over the period were analyzed. Data from the
unit audit were used to provide a comparison group of mothers not given
aromatherapy (n = 15,799) from the study center. OUTCOME MEASURES: Outcome
measures include mothers' ratings of effectiveness, outcomes of labor, use of
pharmacologic pain relief, uptake of intravenous oxytocin, reported associated
symptoms, and annual costs. RESULTS: The use of aromatherapy during childbirth
was an increasingly popular care option with mothers and midwives. More than 50%
of mothers rated it as helpful, and only 14% found it unhelpful. The use of
aromatherapy was not confined to low-risk mothers. Sixty percent of the sample
were primigravidae, and 32% overall had had their labor induced. The
administration of aromatherapy in childbirth did appear to reduce the need for
additional pain relief in a proportion of mothers. More than 8% of primigravidae
and 18% of multigravidae used no conventional pain relief during labor after
using essential oils. During the years of the study, the use of pethidine in the
study center declined from 6% to 0.2% of women. The study also showed that
aromatherapy may have the potential to augment labor contractions for women in
dysfunctional labour. A very low number of associated adverse symptoms were
reported (1%). CONCLUSION: This study represents a successful example of the
integration of a complementary therapy into mainstream midwifery practice and
forms a basis for future research.
PMID- 10784272
TI - Are acupuncture points tender? A blinded study of Spleen 6.
AB - OBJECTIVES: To explore the methodology for investigating the tenderness of
acupuncture points, with particular reference to the hypothesis that the point
Spleen 6 (SP6) is more tender in women than in men. DESIGN: Single-blind,
observational study with volunteers. SETTING: University of Exeter, U.K.
SUBJECTS: Student volunteers, 13 male and 13 female. OUTCOME MEASURES: Pressure
thresholds at SP6, a control acupuncture point Stomach 36, and two nonacupuncture
control sites in each leg were measured weekly for 4 weeks. RESULTS: No
statistically significant differences were found between the pressure thresholds
of SP6 in women and those in men. CONCLUSION: The present study provides no
strong evidence to support the hypothesis that the acupuncture point SP6 is more
tender in women and in men. Recommendations for further investigations are
discussed.
PMID- 10784273
TI - Healing as a therapy for human disease: a systematic review.
AB - OBJECTIVE: To assess, from published clinical trials, the evidence for the use of
healing as a complementary medical intervention in human disease. DESIGN: Limited
to studies involving random assignment to a treatment group consisting of
"healing," broadly defined, or to a concurrent control group. All randomized
trials published up to the year 2000, were identified from MEDLINE, CINAHL, BIDS
EMBASE, the CISCOM complementary medicine databases and from bibliographic
references of published articles. Copies of all published studies were obtained,
data were extracted, and methodological quality (Jadad) scores were derived where
possible. RESULTS: Fifty-nine randomized clinical trials (RCTs) were found
comparing healing with a control intervention on human participants. In 37 of
these, healing was used for existing diseases or symptoms (22 existed as fully
accessible published reports, 10 as dissertation abstracts only, and 5 as
"preliminary" investigations with limited evidential value). The 22 full trials
(10 reporting a "significant" effect of healing compared with control) constitute
an extremely heterogeneous group, varying greatly in the method and duration of
healing; the medical condition treated; the outcome measure employed; and the
control intervention used. Many trials had a number of methodological
shortcomings, including small sample sizes, and were inadequately reported. Only
8 studies (5 with a significant outcome for healing) had a maximum methodological
quality score of 5, and in 10 studies this score was 3 or less. Two trials-both
large scale and methodologically sound-were replicates, and each found a
significant beneficial effect of intercessory prayer on the clinical progress of
cardiac patients. Eleven of the 15 dissertation abstracts and pilot studies
reported nonsignificant results for healing compared with control, a finding that
probably reflects the relatively small sample sizes and the likelihood of type II
errors. The significant heterogeneity found in this group of trials makes
categorization problematic and inhibits the pooling of results by meta-analysis
or similar techniques to obtain a global estimate of the "treatment effect" of
healing. CONCLUSIONS: No firm conclusions about the efficacy or inefficacy of
healing can be drawn from this diverse group of RCTs. Given the current emphasis
on evidence-based medicine, future investigations should be adequately powered,
appropriately controlled, and properly described. These future investigations
would most usefully consist of: (1) pragmatic trials of healing for
undifferentiated conditions on patients based in general practice and (2) larger
RCTs of distant healing on large numbers of patients with well-defined measurable
illness.
PMID- 10784274
TI - Methodological problems of clinical research into spiritual healing: the healer's
perspective.
PMID- 10784275
TI - Placing healers, healees, and healing into a wider research context.
AB - Healers claim that they can relieve, and often heal, injury and illness against
the odds of medical prognosis. Skeptics say that such claims can be accounted for
by possible misdiagnosis, uncritical reportage, placebo response, and coincident
natural improvement. Their a priori objection is that subjective intention in one
person cannot, of itself, affect the physiology and/or mental processes of
another person. This a priori objection becomes invalid if experimental evidence,
using simultaneous electroencephalographic recordings from two or more brains,
has demonstrated that direct brain-to-brain communication can occur. Evidence
that something very unusual is occurring during the healing transaction comes
from recordings of anomalous electrical and magnetic fields generated by healers
when they are in the intention-to-heal mindset.
PMID- 10784276
TI - Researching healing: a psychologist's perspective.
AB - This article suggests that a research agenda for healing should encompass
qualitative issues of value and meaning as well as quantitative issues of
clinical effectiveness. Patients themselves should play an active part in all
stages of the research process in order to ensure that the questions addressed
are relevant to the needs and wants of those who use healing. Research should
address the issues of defining and specifying desired outcomes and clarifying the
specific and nonspecific factors in the healing process as well as investigating
the potential for harm in treatment and minimizing risk. Some specific research
questions are raised. The healing community is challenged to develop a research
agenda that is conceptually and methodologically rigorous, true to the holistic
nature of complementary and alternative medicine, and retains the subversive edge
of the healing traditions.
PMID- 10784277
TI - Colloquium on spiritual healing. Meeting summary: major themes.
PMID- 10784278
TI - The first international meeting of the Research Initiative on Traditional
Antimalarial Methods (RITAM).
AB - The first international meeting of the Research Initiative on Traditional
Antimalarial Methods (RITAM) was held at the Regional Dermatology Training Centre
(RDTC) of the Tumaini University of Health Sciences, Moshi, Tanzania, on December
8-11, 1999. This Inaugural Meeting of RITAM, jointly hosted by the Global
Initiative for Traditional Systems of Health (GIFTS) at Oxford University and the
World Health Organization (WHO), was designed to develop a strategy for more
effective, evidence-based use of traditional medicines that can also inform
malaria-control policy decisions. RITAM was established during 1999 as a network
of researchers and other people who are active or interested in the study and use
of traditional, plant-based antimalarials. RITAM is a partnership between GIFTS
of Health, University of Oxford and the Tropical Disease Research (TDR) Programme
of WHO. Malaria is one of the key health issues affecting developing countries,
particularly in sub-Saharan Africa and Asia. With increasing drug resistance and
the high cost of pharmaceutical drugs, the use of herbal antimalarials is
popular. The conference was attended by biologic and social scientists,
clinicians, traditional healers, and policy makers from Africa, Asia, Europe, and
the Americas. The meeting was funded by the Rockefeller Foundation, the Nuffield
Foundation's Commonwealth Programme, WHO's TDR Programme, and direct support to
delegates was provided by other funders. The meeting addressed the need for
research and policy on the prophylactic and therapeutic effects of medicinal
plants as well as on vector control and repellence. There were five main outputs
from the meeting: (1) targets for making a significant contribution to the
control of malaria through the use of traditional antimalarial methods; (2)
methods for achieving these targets, including ethical guidelines; (3) an
implementation strategy for moving this field ahead quickly and soundly and for
putting research findings into practice; (4) linkages established between
researchers working on traditional antimalarial methods, based on agreed research
priorities and designed to avoid unnecessary replication; and (5) strengthening
the RITAM database of current knowledge on traditional herbal antimalarial
methods. Four specialist groups were established to develop the above: (1)
policy, advocacy, and funding; (2) preclinical studies; (3) clinical development;
and (4) repellance and vector control. These will be coordinated by an executive
committee managed by GIFTS. Two meetings are planned in 2000: a natural-products
chemistry meeting at WHO in Geneva, Switzerland, in June; and a symposium at the
World Congress on Tropical Medicine in Cartagena, Colombia, in August.
PMID- 10784279
TI - The real-time interactive 3-D-DVA for robust coronary MRA.
AB - A graphical user interface (GUI) has been developed which enables interactive
feedback and control to the real-time diminishing variance algorithm (DVA). This
interactivity allows the user to set scan parameters, view scan statistics, and
view image updates during the course of the scan. In addition, the DVA has been
extended to simultaneously reduce motion artifacts in three dimensions using
three orthogonal navigators. Preliminary in vivo studies indicate that these
improvements to the standard DVA allow for significantly improved consistency and
robustness in eliminating respiratory motion artifacts from MR images,
particularly when imaging the coronary arteries.
PMID- 10784280
TI - Unwarping of unidirectionally distorted EPI images.
AB - Echo-planar imaging (EPI) is a fast nuclear magnetic resonance imaging (MRI)
method. Unfortunately, local magnetic field inhomogeneities induced mainly by the
subject's presence cause significant geometrical distortion, predominantly along
the phase-encoding direction, which must be undone to allow for meaningful
further processing. So far, this aspect has been too often neglected. In this
paper, we suggest a new approach using an algorithm specifically developed for
the automatic registration of distorted EPI images with corresponding
anatomically correct MRI images. We model the deformation field with splines,
which gives us a great deal of flexibility, while comprising the affine transform
as a special case. The registration criterion is least squares. Interestingly,
the complexity of its evaluation does not depend on the resolution of the control
grid. The spline model gives us good accuracy thanks to its high approximation
order. The short support of splines leads to a fast algorithm. A multiresolution
approach yields robustness and additional speedup. The algorithm was tested on
real as well as synthetic data, and the results were compared with a manual
method. A wavelet-based Sobolev-type random deformation generator was developed
for testing purposes. A blind test indicates that the proposed automatic method
is faster, more reliable, and more precise than the manual one.
PMID- 10784281
TI - Voxel similarity measures for 3-D serial MR brain image registration.
AB - We have evaluated eight different similarity measures used for rigid body
registration of serial magnetic resonance (MR) brain scans. To assess their
accuracy we used 33 clinical three-dimensional (3-D) serial MR images, with
deformable extradural tissue excluded by manual segmentation and simulated 3-D MR
images with added intensity distortion. For each measure we determined the
consistency of registration transformations for both sets of segmented and
unsegmented data. We have shown that of the eight measures tested, the ones based
on joint entropy produced the best consistency. In particular, these measures
seemed to be least sensitive to the presence of extradural tissue. For these data
the difference in accuracy of these joint entropy measures, with or without brain
segmentation, was within the threshold of visually detectable change in the
difference images.
PMID- 10784282
TI - Automated anatomical labeling of the bronchial branch and its application to the
virtual bronchoscopy system.
AB - This paper describes a method for the automated anatomical labeling of the
bronchial branch extracted from a three-dimensional (3-D) chest X-ray CT image
and its application to a virtual bronchoscopy system (VBS). Automated anatomical
labeling is necessary for implementing an advanced computer-aided diagnosis
system of 3-D medical images. This method performs the anatomical labeling of the
bronchial branch using the knowledge base of the bronchial branch name. The
knowledge base holds information on the bronchial branch as a set of rules for
its anatomical labeling. A bronchus region is automatically extracted from a
given 3-D CT image. A tree structure representing the essential structure of the
extracted bronchus is recognized from the bronchus region. Anatomical labeling is
performed by comparing this tree structure of the bronchus with the knowledge
base. As an application, we implemented the function to automatically present the
anatomical names of the branches that are shown in the currently rendered image
in real time on the VBS. The result showed that the method could segment about
57% of the branches from CT images and extracted a tree structure of about 91% in
branches in the segmented bronchus. The anatomical labeling method could assign
the correct branch name to about 93% of the branches in the extracted tree
structure. Anatomical names were appropriately displayed in the endoscopic view.
PMID- 10784283
TI - A CAD system for the automatic detection of clustered microcalcifications in
digitized mammogram films.
AB - Clusters of microcalcifications in mammograms are an important early sign of
breast cancer. This paper presents a computer-aided diagnosis (CAD) system for
the automatic detection of clustered microcalcifications in digitized mammograms.
The proposed system consists of two main steps. First, potential
microcalcification pixels in the mammograms are segmented out by using mixed
features consisting of wavelet features and gray level statistical features, and
labeled into potential individual microcalcification objects by their spatial
connectivity. Second, individual microcalcifications are detected by using a set
of 31 features extracted from the potential individual microcalcification
objects. The discriminatory power of these features is analyzed using general
regression neural networks via sequential forward and sequential backward
selection methods. The classifiers used in these two steps are both multilayer
feedforward neural networks. The method is applied to a database of 40 mammograms
(Nijmegen database) containing 105 clusters of microcalcifications. A free
response operating characteristics (FROC) curve is used to evaluate the
performance. Results show that the proposed system gives quite satisfactory
detection performance. In particular, a 90% mean true positive detection rate is
achieved at the cost of 0.5 false positive per image when mixed features are used
in the first step and 15 features selected by the sequential backward selection
method are used in the second step. However, we must be cautious when
interpreting the results, since the 20 training samples are also used in the
testing step.
PMID- 10784284
TI - A multiscale dynamic programming procedure for boundary detection in ultrasonic
artery images.
AB - Ultrasonic measurements of human carotid and femoral artery walls are
conventionally obtained by manually tracing interfaces between tissue layers. The
drawbacks of this method are the interobserver variability and inefficiency. In
this paper, we present a new automated method which reduces these problems. By
applying a multiscale dynamic programming (DP) algorithm, approximate vessel wall
positions are first estimated in a coarse-scale image, which then guide the
detection of the boundaries in a fine-scale image. In both cases, DP is used for
finding a global optimum for a cost function. The cost function is a weighted sum
of terms, in fuzzy expression forms, representing image features and geometrical
characteristics of the vessel interfaces. The weights are adjusted by a training
procedure using human expert tracings. Operator interventions, if needed, also
take effect under the framework of global optimality. This reduces the amount of
human intervention and, hence, variability due to subjectiveness. By
incorporating human knowledge and experience, the algorithm becomes more robust.
A thorough evaluation of the method in the clinical environment shows that
interobserver variability is evidently decreased and so is the overall analysis
time. We conclude that the automated procedure can replace the manual procedure
and leads to an improved performance.
PMID- 10784285
TI - New variants of a method of MRI scale standardization.
AB - One of the major drawbacks of magnetic resonance imaging (MRI) has been the lack
of a standard and quantifiable interpretation of image intensities. Unlike in
other modalities, such as X-ray computerized tomography, MR images taken for the
same patient on the same scanner at different times may appear different from
each other due to a variety of scanner-dependent variations and, therefore, the
absolute intensity values do not have a fixed meaning. We have devised a two-step
method wherein all images (independent of patients and the specific brand of the
MR scanner used) can be transformed in such a way that for the same protocol and
body region, in the transformed images similar intensities will have similar
tissue meaning. Standardized images can be displayed with fixed windows without
the need of per-case adjustment. More importantly, extraction of quantitative
information about healthy organs or about abnormalities can be considerably
simplified. This paper introduces and compares new variants of this standardizing
method that can help to overcome some of the problems with the original method.
PMID- 10784286
TI - Using the Job-Related Affective Well-Being Scale (JAWS) to investigate affective
responses to work stressors.
AB - Prior research linking job stressors to psychological strains has been limited to
a small number of emotional reactions. This article describes research linking
job stressors to a wide range of affective states at work. In Study 1, a
multidimensional scaling procedure was used on a matrix of similarity judgments
by 51 employees of 56 job-related affective statements to support a 2-dimensional
view of affective well-being. In Study 2, ratings of the affect statements by 100
employees further supported the contention that the dimensions were pleasure
displeasure and degree of arousal. In Study 3, 114 full-time university employees
responded to the Job-Related Affective Well-Being Scale, which was found to be
related to measures of job stressors as well as job satisfaction and physical
symptoms.
PMID- 10784287
TI - Lean production teams and health in garment manufacture.
AB - The impact of lean production on psychological health was assessed by comparing
lean production teams in garment manufacture with a traditional system for making
similar garments. Work design characteristics were examined as mediators of the
impact of work organization on health. Findings indicate both positive and
negative direct effects of teamworking on aspects of autonomy, work demands, and
social climate. In turn, both positive and negative direct effects of work design
on psychological health were found, which combine to give no overall difference
between the groups. This study suggests that the balance between positive and
negative effects of lean production teamworking depends on management choices in
the form of work design.
PMID- 10784288
TI - Interpersonal conflict at work and psychological outcomes: testing a model among
young workers.
AB - On the basis of A. P. Fiske's (1992) general theory of social relations, a model
of interpersonal conflict at work was developed and tested in a sample of young
workers. The model predicts that conflict with supervisors is predictive of
organizationally relevant psychological outcomes (job satisfaction,
organizational commitment, and turnover intentions), whereas conflict with
coworkers is predictive of personally relevant psychological outcomes
(depression, self-esteem, and somatic symptoms). Data were obtained from a sample
of 319 individuals ages 16 to 19 years. Structural equation modeling results
supported the hypothesized relations. Secondary regression analysis of 2 data
sets from M. A. Donovan, F. Drasgow, and L. J. Munson (1998) provides initial
support for the generalizability of the hypothesized model to older employees.
PMID- 10784289
TI - Linear and nonlinear relations between psychosocial job characteristics,
subjective outcomes, and sickness absence: baseline results from SMASH. Study on
Musculoskeletal Disorders, Absenteeism, Stress, and Health.
AB - This study investigates the demand-control-support (DCS) model by (a) using a
more focused measure of job control, (b) testing for interactive and nonlinear
relationships, and (c) further extending the model to the prediction of an
objective outcome measure (i.e., company-administrated sickness absence).
Hypotheses were tested in a heterogeneous sample of 1,739 employees from a 3-year
prospective cohort study called SMASH (Study on Musculoskeletal Disorders,
Absenteeism, Stress, and Health). Baseline results showed that a linear additive
model was superior for job satisfaction, psychosomatic health complaints, and
sickness absence, whereas a curvilinear model was superior for emotional
exhaustion and depression. It is concluded that, first, there was no evidence of
interactive effects. Second, it seems sensible to pay more attention to
curvilinear relationships in future research. Finally, the DCS model was not
supported using a more objective outcome measure.
PMID- 10784290
TI - Organizational and individual factors affecting mental health and job
satisfaction: a multilevel analysis of job control and personality.
AB - This study evaluated variation at the individual and work unit levels in the
relations of job control, hostility, and trait anxiety to mental health and job
satisfaction. Questionnaire data from a sample of 2,900 employees working at 152
hospital wards were analyzed by means of multilevel regression analyses. Results
showed that mental health (General Health Questionnaire-12), varying mainly at
the individual level, was explained mostly by hostility and trait anxiety. Job
satisfaction varied significantly at the individual and the ward level. Job
control accounted for most of this multilevel variation. Thus, this study
demonstrated the significance of individual characteristics and organizational
effects in explaining the mental health and job satisfaction of employees.
PMID- 10784291
TI - Consequences associated with work-to-family conflict: a review and agenda for
future research.
AB - A comprehensive review of the outcomes associated with work-to-family conflict
was conducted and effect sizes were estimated. Atypology was presented that
grouped outcomes into 3 categories: work related, nonwork related, and stress
related. Issues concerning the measurement of work-family conflict were also
discussed. The results demonstrate the widespread and serious consequences
associated with work-to-family conflict. On the basis of the results of the
review, an agenda for future research was provided.
PMID- 10784292
TI - Implementing a stress management training: comparative trainer effectiveness.
AB - Participants who were recruited from various organizations were randomly assigned
to 1 of 2 stress management training (SMT) conditions or an assessment-only
control group. The groups in the 1st SMT condition were led by external clinical
psychologists. The groups in the 2nd SMT condition were led by individuals who
held posts within the organizations involved, referred to as paraprofessionals.
Results show favorable effects of the SMT program both in the short term as well
as at 6-month follow-up. Results showed no serious differences in effectiveness
between trainers. It is argued that, to be effective, the SMT program does not
necessarily have to be given by clinical psychologists only but may instead be
given by individuals from other professional orientations.
PMID- 10784293
TI - Sequence analysis of genes and genomes.
AB - A major step towards understanding of the genetic basis of an organism is the
complete sequence determination of all genes in its genome. The development of
powerful techniques for DNA sequencing has enabled sequencing of large amounts of
gene fragments and even complete genomes. Important new techniques for physical
mapping, DNA sequencing and sequence analysis have been developed. To increase
the throughput, automated procedures for sample preparation and new software for
sequence analysis have been applied. This review describes the development of new
sequencing methods and the optimisation of sequencing strategies for whole genome
and cDNA analysis, as well as discusses issues regarding sequence analysis and
annotation.
PMID- 10784294
TI - Screening hydrolysis over two-phases.
AB - A new assay is described that monitors hydrolysis with the concurrent transfer of
a solvatochromic dye across an oil-water barrier. Through the appropriate design,
this transfer is accompanied by a 10(6) gain in fluorescence. This response can
be used to effectively screen hydrolytic activity at high-throughput. Using this
method, microunits of alkaline phosphatase, glucosidases, as well as several
common proteases can be visually detected within an hour through concentration
over a 200:1 volumetric ratio of aqueous to organic phases. Development of a
water-solublizing protecting group extends this methodology to screen a wide
range of processes that undergo cleavage of a covalent bond.
PMID- 10784296
TI - Carotenoid content of chlorophycean microalgae: factors determining lutein
accumulation in Muriellopsis sp. (Chlorophyta).
AB - Fifteen strains of chlorophycean microalgae have been investigated with regard to
their carotenoid profile. Lutein, beta-carotene and violaxanthin were present in
virtually all of the strains, lutein, in general, being the most abundant
carotenoid, whereas canthaxanthin and astaxanthin were found in some strains
only. Chlorella fusca SAG 211-8b, Chlorococcum citriforme SAG 62.80, Muriellopsis
sp., Neospongiococcum gelatinosum SAG B 64.80 and Chlorella zofingiensis CCAP
211/14 exhibited high lutein levels, the latter strain containing in addition
substantial amounts of astaxanthin. Muriellopsis sp. was further characterized,
since besides a high lutein content (up to 35 mg l(-1) culture), it had the
highest growth rate (up to 0.17-0.23 h(-1)) and maximal standing cell density (up
to 8 x 10(10) cells l(-1) culture). These levels of lutein are in the range of
those reported for astaxanthin in Haematococcus and for beta-carotene in
Dunaliella, microalgae of recognized interest for the production of these
carotenoids. Lutein content of Muriellopsis sp. increased during the exponential
phase of growth, with the highest value being recorded in the early stationary
phase. Maximum levels of lutein in Muriellopsis sp. cultures were recorded at 20
40 mM NaNO3, 2-100 mM NaCl, 460 micromol photon m(-2) s(-1), pH 6.5 and 28
degrees C, conditions which were, in general, also optimal for cell growth.
Growth-limiting conditions, such as pH values of 6 or 9 and a temperature of 33
degrees C, were found to stimulate carotenogenesis in Muriellopsis sp. This
strain represents a potential source of lutein, a commercially interesting
carotenoid of application in aquaculture and poultry farming, as well as in the
prevention of cancer and diseases related to retinal degeneration.
PMID- 10784295
TI - Enzymatic degumming of ramie bast fibers.
AB - Bast fibers from ramie (Boehmeria nivea) were treated with cell-free culture
supernatants from an Amycolata sp. and a recombinant Streptomyces lividans strain
expressing the Amycolata pectate lyase to investigate the degumming effects of
different extracellular polysaccharide-degrading enzymes. Culture supernatants
from the Amycolata sp. with high pectate lyase activities were most effective in
fiber separation and reduced the gum content of ramie fibers by 30% within 15 h.
Xylanase activity produced by the Amycolata sp. contributed little to the
degumming. Electron micrographs showed that the crude pectate lyase from the
Amycolata sp. removed plant gum more efficiently from decorticated ramie bast
fibers than the purified enzyme. Similarly, degumming with the crude enzyme of
the Amycolata sp. and the recombinant S. lividans strain for 24 h resulted in
fibers with a residual gum content of 14.7 and 17.3%, respectively. Degumming
with the crude enzyme of the recombinant Streptomyces strain was slightly
improved by the addition of a commercial pectinesterase. No significant degumming
was observed with the crude enzyme from an S. lividans strain that did not
produce the Amycolata pectate lyase. These results indicate that the pectinolytic
activity of the Amycolata sp. plays an active role in degumming of ramie bast
fibers.
PMID- 10784297
TI - Monitoring cellular state transitions in a production-scale CHO-cell process
using an electronic nose.
AB - An electronic nose is used to monitor the bioreactor off-gas composition in
perfused cultivations of a CHO-cell line producing recombinant human blood
coagulation factor VIII. The applicability of the electronic nose for monitoring
cellular state transitions and process control is explained. It is shown that the
instrument can reveal characteristic process states related to product and
lactate formation, and detect microbial infections in a very early stage of the
infection. The visualization of ideal process conditions is realized by using
principal component analysis (PCA) and the on-line applicability of this method
is outlined. The results illustrate the potential of the electronic nose as on
line sensor for ensuring product and process quality in production-scale
bioprocesses.
PMID- 10784298
TI - Establishment of forskolin yielding transformed cell suspension cultures of
Coleus forskohlii as controlled by different factors.
AB - Suspension cultures derived from gall calli which were obtained following
infection with Agrobacterium tumefaciens (C58) were established in Coleus
forskohlii. Cell line selection following single cell cloning or cell aggregate
cloning was carried out to select cell lines capable of fast growth and for
producing high level of forskolin. A fast growing cell line (GSO-5/7) thus
selected was found to accumulate 0.021% forskolin in 42 days. The effect of
cultural conditions on cell growth was studied to identify factors influencing
biomass yield. Cell growth in suspension was found to be influenced significantly
by carbon source, initial cell density and light or dark condition. Optimal cell
growth (20 fold increase in biomass in a 42 day period) was obtained when the
cells were grown in dark condition in B5O media containing 3% sucrose as sole
carbon source with an initial cell density of 1.5 x 10(5) cells per ml. Forskolin
accumulation was maximum (0.021%) in the stationary phase of cell growth. These
suspension cultures showed continuous and stable production of forskolin.
PMID- 10784299
TI - Anaerobic thermophilic fermentation for acetic acid production from milk
permeate.
AB - Fermentation of milk permeate to produce acetic acid under anaerobic thermophilic
conditions (approximately 60 degrees C) was studied. Although none of the known
thermophilic acetogenic bacteria can ferment lactose, it has been found that one
strain can use galactose and two strains can use lactate. Moorella
thermoautotrophica DSM 7417 and M. thermoacetica DSM 2955 were able to convert
lactate to acetate at thermophilic temperatures with a yield of approximately
0.93 g g(-1). Among the strains screened for their abilities to produce acetate
and lactate from lactose, Clostridium thermolacticum DSM 2910 was found precisely
to produce large amounts of lactate and acetate. However, it also produced
significant amounts of ethanol, CO2 and H2. The lactate yield was affected by
cell growth. During the exponential phase, acetate, ethanol, CO2 and H2 were the
main products of fermentation with an equimolar acetate/ethanol ratio, whereas
during the stationary phase, only lactic acid was produced with a yield of 4 mol
per mol lactose, thus reaching the maximal theoretical value. When this bacterium
was co-cultured with M. thermoautotrophica, lactose was first converted mainly to
lactic acid, then to acetic acid, with a zero residual lactic acid concentration
and an overall yield of acetate around 80%. Under such conditions, only 13% of
the fermented lactose was converted to ethanol by C. thermolacticum.
PMID- 10784300
TI - Revisiting the Glasgow Coma Scale and Coma Score.
PMID- 10784301
TI - A clear view: the way forward for eye care on ICU. Intensive care units.
PMID- 10784302
TI - Glasgow Coma Scale: variation in mortality among permutations of specific total
scores.
AB - OBJECTIVE: The objective of this study was to determine whether different score
permutations of the Glasgow Coma Scale (GCS) giving the same GCS total score were
associated with significantly different mortality. DESIGN: For each GCS total we
compared the mortality associated with each of the different GCS permutations
using a Fisher's exact test. The relationship between components of the GCS score
and mortality was also examined using uni- and multivariate logistic regression.
SETTING: Data were collected from the intensive care unit at Wellington Hospital,
a multidisciplinary, tertiary referral unit. PATIENTS: We analysed the GCS and
mortality data from all admissions over a 4 year period (January 1994-January
1998). Patients with GCS scores of 3 or 15 were excluded, since these two total
scores do not have multiple permutations, leaving 1,390 patients with GCS scores
of 4-14 for analysis. RESULTS: The incidence of mortality was significantly
different for the different permutations for total GCS scores of 7, 9, 11 and 14.
CONCLUSIONS: It is possible for patients to have the same total GCS score, but
significantly different risks of mortality due to differences in the GCS profile
making up that score. This suggests that GCS scores may be more useful reported
in terms of profiles rather than totals. This could also have implications for
the use of other scoring systems such as Acute Physiology and Chronic Health
Evaluation and Simplified Acute Physiology Score.
PMID- 10784303
TI - Eye care for the critically ill.
AB - PURPOSE: To evaluate the effectiveness and efficiency of an algorithm in the
prevention of ocular surface disease in sedated and unconscious patients in the
intensive care unit (ICU). METHODS: The eyes of all sedated and unconscious
patients admitted to an ICU between September and December 1998 were managed
according to an eye care algorithm. The applications of the preventive measures
were assessed by a single observer twice weekly. The lid position, the presence
and degree of keratopathy, sedation score, and the treatment received were
documented at every assessment. RESULTS: Thirty-four patients were recruited for
management according to the eye care algorithm over a period ranging from 1 to 28
days. Four patients were excluded because of failure by staff to adhere to the
protocol. In 18 patients no active treatment was required. Out of six patients
who had conjunctival exposure and were given ocular lubricants, four maintained
clear corneas. No corneal or conjunctival staining was noted in two of the four
patients whose lids required closure with Micropore tape for corneal exposure.
Use of lid taping and lubricants prevented corneal abrasion in two patients who
were prone ventilated. The prevalence of ocular surface abnormalities was 8.7 %
where the algorithm was properly followed (23 patients). CONCLUSION: The proposed
eye care algorithm appears to be effective in preventing ocular surface
abnormalities in the sedated and unconscious patients in the ICU, and efficient
in that it may reduce the workload required for critically ill patients.
PMID- 10784304
TI - Incidence and mortality of severe sepsis in surgical intensive care patients: the
influence of patient gender on disease process and outcome.
AB - OBJECTIVE: Laboratory studies demonstrated significant detrimental effects of
male sex-steroids (testosterone) on immune functions following hemorrhagic shock
and soft-tissue trauma. Moreover, better survival of female mice subjected to
severe sepsis was observed when compared to male animals. The aims of the present
study were to evaluate whether or not gender differences regarding incidence and
mortality of severe sepsis do exist in surgical intensive care patients and to
elucidate the influence of patient age on incidence and mortality of severe
sepsis/septic shock. DESIGN: Data base review of prospectively collected data
from surgical intensive care patients. SETTING: Surgical intensive care unit of
the department of surgery of a university hospital. PATIENTS: Prospectively
collected data of 4,218 intensive care patients (2,709 male, 1,509 female).
RESULTS: Significantly fewer female patients were referred to the intensive care
unit (6.6 % vs 10.8 % of all patients; P < 0.05) leading to a significantly
smaller proportion of female intensive care patients (35.8% vs 64.2%). No gender
differences regarding number of failing organs or surgical procedure (exception
vascular surgery) were observed in patients with and without severe sepsis/septic
shock, indicating that the patients studied are comparable regarding general
health prior to admission to SICU. Among all female patients referred to SICU
only 7.6 % developed severe sepsis/septic shock, while 10.4% of all male patients
suffered from severe sepsis or septic shock (P < 0.05). This gender difference
results from a significantly lower incidence of severe sepsis/ septic shock in
female patients between 60 and 79 years. No gender difference regarding mortality
rates of severe sepsis/septic shock was observed (men 64.9 %, women 65.5%).
CONCLUSIONS: Our results indicate a significantly smaller number of female
patients requiring intensive care as well as a significantly lower incidence of
severe sepsis/septic shock in female intensive care patients. Mortality from
severe sepsis/ septic shock, however, is not affected by gender.
PMID- 10784305
TI - Monitoring the circulatory responses of shocked patients during fluid
resuscitation in the emergency department.
AB - OBJECTIVES: To assess the feasibility of constructing left ventricular response
curves non-invasively during the fluid resuscitation of critically ill patients
in the emergency department (ED) using a portable suprasternal Doppler ultrasound
(PSSDU) device. DESIGN: Prospective case series. SETTING: Emergency department,
Catholic University of Leuven, Belgium. PATIENTS: Shocked patients in the ED were
diagnosed by predefined criteria. Only those thought to require standardised
intravenous colloid challenges were observed i. e., sequential boluses of 3.5
ml/kg/10 min titrated against changes in stroke distance (Doppler surrogate for
left ventricular stroke volume). RESULTS: A total of 50 shocked patients were
studied. Stroke distance was measurable in 45 patients. 35 patients were fluid
responders in terms of stroke distance. Group mean stroke distance increased
during resuscitation (8.6 +/- 4.1 cm to 19.5 +/- 4.6 cm, P < 0.001) and then
reached a plateau value (19.6 +/- 4.6 cm, P = 0.488). No response to fluid was
seen in nine patients of which eight had severe sepsis. Alternative therapeutic
approaches increased stroke distance for all of these patients. Evidence for
right ventricular dysfunction was found as a cause for fluid non-response in the
majority of patients with sepsis. CONCLUSIONS: Previous experimental work has
shown that changes in central blood flow can be derived using the PSSDU device.
This clinical feasibility study suggests that the PSSDU can help tailor
haemodynamic therapy for an individual patient and give an early indication of
treatment failure in the ED.
PMID- 10784306
TI - Assessment of cardiac preload and extravascular lung water by single
transpulmonary thermodilution.
AB - OBJECTIVE: Transpulmonary double-indicator dilution is a useful monitoring
technique for measurement of intrathoracic blood volume (ITBV) and extravascular
lung water (EVLW). In this study, we compared a simpler approach using single
arterial thermodilution derived measurements of ITBV and EVLW with the double
indicator dilution technique. DESIGN: Prospective observational clinical study.
SETTING: Surgical intensive care units of two university hospitals. PATIENTS AND
METHODS: Global end-diastolic volume (GEDV) derived from single thermodilution
was used for calculation of ITBV. Structural regression analysis of the first two
thermo-dye dilution measurements in a derivation population of 57 critically ill
patients (38 male, 19 female, 18-79 years, 56 +/- 15 years) revealed ITBV = (1.25
x GEDV)-28.4 (ml). This equation was then applied to all first measurements in a
validation population of 209 critically ill patients (139 male, 70 female, 10-88
years, mean 53 +/- 19 years), and single-thermodilution ITBV (ITBV(ST)) and EVLW
(EVLW(ST)) was calculated and compared to thermo-dye dilution derived values
(ITBV(TD), EVLW(TD)). For inter-individual comparison, absolute values for ITBV
and EVLW were normalised as indexed by body surface area (ITBVI) and body weight
(EVLWI), respectively. MEASUREMENTS AND RESULTS: Linear regression analysis
yielded a correlation of ITBVI(ST) = (1.05 x ITBVI(TD))-58.0 (ml/m2), r = 0.97, P
< 0.0001. Bias between ITBVI(TD) and ITBVI(ST) was 7.6 (ml/m2) with a standard
deviation of 57.4 (ml/m2). Single-thermodilution EVLWI (EVLWI(ST)) was calculated
using ITBVI(ST) and revealed the correlation EVLWI(ST) = (0.83 x EVLWI(TD)) + 1.6
(ml/kg), r = 0.96, P < 0.0001. Bias between EVLWI(TD) and EVLWI(ST) was -0.2
(ml/kg) with a standard deviation of 1.4 (ml/kg). In detail, EVLWI(ST)
systematically overestimated EVLWI(TD) at low-normal values for EVLWI and
underestimated EVLWI at higher values (above 12 ml/kg). CONCLUSION:
Determinations of ITBV and EVLW by single thermodilution agreed closely with the
corresponding values from the double-indicator technique. Since transpulmonary
single thermodilution is simple to apply, less invasive and cheaper, all these
features make it a promising technique for the bedside. Nevertheless, further
validation studies are needed in the future.
PMID- 10784307
TI - Inhaled prostacyclin and platelet function after cardiac surgery and
cardiopulmonary bypass.
AB - OBJECTIVE: To study the effects of 6 h inhalation of aerosolized prostacyclin
(PGI2) on platelet function. DESIGN: In a prospective, double-blind, randomized
study, 28 patients scheduled for elective cardiac surgery requiring
cardiopulmonary bypass (CPB), received either 0.9% sodium chloride (n = 8), PGI2
5 microg x ml(-1) (n = 10) or PGI2 10 microg x ml(-1) (n = 10) as an aerosol for
6 h postoperatively. SETTING: Cardiothoracic intensive care unit at a university
hospital. INTERVENTIONS: All patients were studied immediately after surgery
during mechanical ventilation and sedation. The PGI2 solutions or saline were
administered with a jet nebulizer. MEASUREMENTS AND RESULTS: Bleeding time and
chest tube drainage were measured. Blood samples for platelet aggregation,
thrombelastography (TEG) and analysis of coagulation parameters and the stable
prostacyclin metabolite 6-keto-PGF1alpha were obtained immediately before
inhalation and after 2, 4 and 6 h of inhalation. After 6 h of PGI2 inhalation,
regardless of administered dose, there was a lower rate of platelet aggregation
and a lower maximal increase in light transmission in response to adenosine
diphosphate (ADP) than in the control group. The TEG variable reaction time (R)
was prolonged after 4 and 6 h of inhalation in the PGI2 group receiving 10 microg
x ml(-1). There were no differences between groups with respect to bleeding time
and chest tube drainage or any of the other variables examined. CONCLUSION:
Inhalation of PGI2 for 6 h in patients after cardiac surgery is associated with
impaired platelet aggregation detected by in vitro techniques, with no in vivo
signs of platelet dysfunction.
PMID- 10784308
TI - Experiences with severe P. falciparum malaria in the intensive care unit.
AB - OBJECTIVE: To review the clinical profiles and therapies instituted for patients
with severe malaria admitted to an ICU. DESIGN: Retrospective study. SETTING:
Internal ICU of a tertiary care centre. PATIENTS AND PARTICIPANTS: Between
January, 1992, and February, 1999, 104 patients with malaria were admitted to the
General Hospital of Vienna. Sixty-nine patients suffered from Plasmodium
falciparum malaria (66%), seven of these were admitted to the ICU. MEASUREMENT
AND RESULTS: Seven patients were admitted to the ICU, of whom three died (4% in
hospital case-fatality rate). Four patients required mechanical ventilation
because of respiratory insufficiency and adult respiratory distress syndrome
(ARDS), of whom three died. Three patients were treated with inhaled nitric oxide
(NO) and kinetic therapy; one patient required extracorporeal veno-venous
oxygenation. All patients who died required haemofiltration because of acute
renal failure. CONCLUSION: As P. falciparum is a potentially life-threatening
disease, reliable criteria for ICU admission should be defined and risk factors
identified. Early ICU monitoring should be attempted, especially under the
following conditions: (1) lack of clinical response to anti-malarial treatment
within 48 h and/or (2) any signs of neurological disturbance (hypoglycaemia
excluded). Prospective multicentre trials and guidelines for supportive intensive
care are urgently needed.
PMID- 10784309
TI - Cerebral blood flow and metabolism in severe brain injury: the role of pressure
autoregulation during cerebral perfusion pressure management.
AB - OBJECTIVE: To ascertain if norepinephrine can be used as part of the cerebral
perfusion pressure (CPP) management to increase arterial blood pressure (MAP)
without causing cerebral hyperemia after severe head injury (HI). DESIGN:
Prospective, interventional study. SETTING: Intensive care unit in a university
hospital. PATIENTS: Twelve severely HI patients; median Glasgow Coma Scale was 6
(range 3-8). INTERVENTIONS: CPP management ( = 70 mmHg). Pressure autoregulation
(assessed by norepinephrine infusion) was defined intact if % CPP/%CVR < or = 2.
RESULTS: Cerebral blood flow (CBF: Xe133 inhalation technique), jugular bulb
oxygen saturation (SjO2) and transcranial Doppler (TCD) were recorded during the
test. Norepinephrine increased CPP by 33 % (+/- 4). Autoregulation was found to
be intact in ten patients and defective in two. In the ten patients with
preserved autoregulation, CBF decreased from 31 +/- 3 to 28 +/- 3 ml/ 100 g/min;
in the two patients with impaired autoregulation CBF increased respectively from
16 to 35 and from 21 to 70 ml/100 g/min. SjO2 did not change significantly from
baseline. TCD remained within the normal range. CONCLUSIONS: During CPP
management norepinephrine can be used to increase MAP without potentiating
hyperemia if pressure autoregulation is preserved. The assessment of pressure
autoregulation should be considered as a guide for arterial pressure-oriented
therapy after HI.
PMID- 10784310
TI - Sonoclot signature during normal pregnancy.
AB - OBJECTIVE: The Sonoclot analyser provides global measurement of haemostasis,
including plasma coagulation, platelet function and fibrinolysis. Benefits of its
use in cardiovascular and hepatic surgery are well-documented and it may be
useful in managing obstetric complications. The aim of this study was to
determine ranges of the Sonoclot variables for normal pregnancy. DESIGN:
Prospective and longitudinal study. SETTING: Antenatal outpatient clinic,
university hospital. PATIENTS: Forty-seven healthy women were studied; forty-two
completed normal pregnancies and gave birth to healthy infants. INTERVENTIONS:
None. MEASUREMENTS AND RESULTS: Sonoclot signatures were performed at 10-15, 32
34 and 38-40 weeks of gestation and at 8 weeks postpartum. Haemoglobin
concentration, haematocrit, platelet count, fibrinogen and activated partial
thromboplastin time (APTT) were analysed with normal results. Sonact time and
peak time were significantly decreased and clot rate and secondary rate were
significantly increased during pregnancy compared with 8 weeks postpartum,
indicating hypercoagulability. There were no significant changes in these
variables during pregnancy. There were no changes in peak amplitude and downward
rate. A significant correlation was found between sonact time and APTT, and
between clot rate and APTT. CONCLUSIONS: We found the Sonoclot analyser simple to
handle and the signatures easy to interpret. The ranges for the Sonoclot
variables apply throughout pregnancy. The ranges for sonact time, clot rate,
secondary rate and peak time during pregnancy differed from the ranges at 8 weeks
postpartum.
PMID- 10784311
TI - Trimethoprim-sulfamethoxazole-induced aseptic meningitis: case report and
literature review.
AB - Aseptic meningitis is a rare adverse drug reaction, reported with non-steroidal
anti-inflammatory agents (NSAIDs) and with miscellaneous drugs such as
trimethoprim-sulfamethoxazole (TMP-SMX). The most common clinical findings
reported are fever, headache, stiffness and altered level of consciousness. We
report a case of aseptic meningitis related to TMP-SMX ingestion that caused
severe derangements of the patient's vital signs, requiring Intensive Care Unit
admittance. The prompt diagnosis and discontinuation of the drug resulted in
complete recovery. We examine the case according to the literature on this topic.
We conclude that, since the signs and symptoms of this unusual drug reaction may
mimic those of central nervous system infection, the clinician should consider
this etiology when he is faced with a patient with suspected meningoencephalitis,
especially if the latter has already been treated at home with unknown drugs.
Further studies should investigate the pathogenetic mechanism of TMP-SMX-induced
aseptic meningitis.
PMID- 10784312
TI - Zinc chloride smoke inhalation: a rare cause of severe acute respiratory distress
syndrome.
AB - Zinc chloride smoke inhalation is a rare cause of slowly progressive and often
fatal acute respiratory distress syndrome (ARDS). The conventional treatment
includes intravenous N-acetylcysteine, L-3, 4-dehydroproline, methylene blue, and
respiratory support according to the lung protective strategy. This report
presents the cases of three patients with serious zinc chloride inhalation and
ARDS, the last of whom survived after prolonged intensive care,
videothoracoscopic excision of emphysema bullae, and recurrent chemical
pleurodesis.
PMID- 10784313
TI - Transient EDTA-dependent pseudothrombocytopenia in a patient with sepsis.
AB - Ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia (EDTA-PTCP) is
the phenomenon of a spurious low platelet count due to antiplatelet antibodies
that cause platelet clumping in blood anticoagulated with EDTA. We describe a
case of EDTA-PTCP that appeared transiently with the development of sepsis. A 50
year-old man underwent Bentall's aortic root replacement for acute aortic
dissection with aortic insufficiency. Postoperatively the patient suffered
paralytic ileus followed by methicillin-resistant Staphylococcus aureus enteritis
and septicemia with endotoxemia. EDTA-PTCP appeared with the development of
sepsis, and disappeared with its resolution. To avoid incorrect diagnoses and
inappropriate treatment, EDTA-PTCP should always be considered as a possible
cause of reported low platelet counts, even in patients with sepsis.
PMID- 10784314
TI - Effect of inhaled nitric oxide in combination with almitrine on ventilation
perfusion distributions in experimental lung injury.
AB - OBJECTIVE: To investigate a possible additive effect of combined nitric oxide
(NO) and almitrine bismesylate (ALM) on pulmonary ventilation-perfusion (V(A)/Q)
ratio. DESIGN: Prospective, controlled animal study. SETTING: Animal research
facility of a university hospital. INTERVENTIONS: Three conditions were studied
in ten female pigs with experimental acute lung injury (ALI) induced by repeated
lung lavage: 1) 10 ppm NO, 2) 10 ppm NO with 1 microg/kg per min ALM, 3) 1
microg/ kg per min ALM. For each condition, gas exchange, hemodynamics and V(A)/Q
distributions were analyzed using the multiple inert gas elimination technique
(MIGET). MEASUREMENT AND RESULTS: With NO + ALM, arterial oxygen partial pressure
(PaO2) increased from 63 +/- 18 mmHg to 202 +/- 97 mmHg while intrapulmonary
shunt decreased from 50 +/- 15 % to 26 +/- 12% and blood flow to regions with a
normal V(A)/Q ratio increased from 49 +/- 16 % to 72 +/- 15 %. These changes were
significant when compared to untreated ALI (p < 0.05) and NO or ALM alone (p <
0.05), although improvements due to NO or ALM also reached statistical
significance compared to ALI values (p < 0.05). CONCLUSIONS: We conclude that NO
+ ALM results in an additive improvement of pulmonary gas exchange in an
experimental model of ALI by diverting additional blood flow from non-ventilated
lung regions towards those with normal V(A)/Q relationships.
PMID- 10784316
TI - Meta-analyses versus randomised controlled trials in intensive care medicine.
PMID- 10784315
TI - Mitigation of endotoxin-induced acute lung injury in ventilated rabbits by
surfactant and inhaled nitric oxide.
AB - OBJECTIVE: To evaluate the efficacy of surfactant and inhaled nitric oxide (iNO)
in endotoxin-induced acute lung injury (ALI). DESIGN: Prospective, randomised,
controlled experimental study. SETTING: A medical university hospital research
laboratory. INTERVENTION: Twenty-nine adult rabbits (2.4-3.4 kg) were given two
doses of intravenous endotoxin (Escherichia coli) (0.01 mg/kg and, 12 h later,
0.1 mg/kg), and then subjected to mechanical ventilation. After 8 h these animals
were allocated to four treatment groups: (1) control, (2) iNO at 20 ppm (NO), (3)
surfactant at 100 mg/kg (Surf) and (4) both surfactant and iNO as in groups 2 and
3 (SNO), and ventilated for a further 6 h followed by broncho-alveolar lavage
(BAL), analysis of surfactant contents in BAL fluid and histological examination
of the lungs. MEASUREMENTS AND RESULTS: All the animals had developed ALI with
respiratory failure 8 h after the second dose of endotoxin as evidenced by a
decrease of PaO2/FIO2 from 520 +/- 30 to 395 +/- 19 mmHg and dynamic compliance
(Cdyn) from 1.20 +/- 0.11 to 0.73 +/- 0.05 ml/ cmH2O x kg, and an increase of
intrapulmonary shunting (Qs/Qt) from 7.5 +/- 0.8% to 12.9 +/- 1.0% (all
measurements p < 0.01 versus baseline). In the SNO group, values for PaO2/FIO2,
Cdyn and Qs/Qt after 6 h were 301 +/- 15 mmHg, 0.67 +/- 0.05 ml/cmH2O x kg and
16.5 +/- 0.8%, compared to 224 +/- 26 mmHg, 0.53 +/- 0.04 ml/ cmH2O x kg and 24.1
+/- 2.0%, respectively, in the control group (all measurements p < 0.01). Both
Surf and NO groups showed intermediate levels of these parameters. In both Surf
and SNO groups, the minimum surface tension of BAL fluid was lower, and the
content of disaturated phosphatidylcholine/total protein higher, than in the
control and NO groups (p < 0.01). Histological features of lung injury were less
prominent and wet/dry lung weight ratio lower in the NO, Surf and SNO groups.
Decreased surfactant protein A (SP-A) and its mRNA expression were found in all
endotoxin-exposed groups, but the SP-A content of the SNO group was moderately
improved in comparison to the control group. Surfactant aggregate size was not
affected. CONCLUSION: Early application of surfactant and iNO moderately
mitigated ALI as reflected by improvement of lung mechanics, pulmonary perfusion
and morphology.
PMID- 10784317
TI - Non-invasive ventilation in acute hypoxemic respiratory failure.
PMID- 10784318
TI - Anti-microbial or antiseptic impregnated central venous catheters: update on a
"central" debate.
PMID- 10784319
TI - Neck ties as vectors for nosocomial infection.
PMID- 10784320
TI - Primary heart angiosarcoma: an infrequent cause of acute respiratory failure.
PMID- 10784321
TI - Acute myocardial infarction with normal coronary arteries during septic shock
from Neisseria meningitidis.
PMID- 10784322
TI - Pericardial effusion: a rare complication of thermal burn.
PMID- 10784323
TI - Carcinoid crisis during transesophageal echocardiography.
PMID- 10784324
TI - Successful resuscitation using nitroglycerin for refractory pulseless electrical
activity in intensive care unit.
PMID- 10784325
TI - Esmolol in the treatment of severe arrhythmia after acute trichloroethylene
poisoning.
PMID- 10784326
TI - Life-threatening magnesium toxicity.
PMID- 10784327
TI - A very early onset of respiratory failure due to phenytoin-associated
hypersensitivity syndrome and concomitant glucocorticoid administration.
PMID- 10784328
TI - Hypocholesterolemia in critically ill patients.
PMID- 10784329
TI - Oral health status of patients 5-6 years after placement of cobalt-chromium
removable partial dentures.
AB - This study is a clinical survey of cobalt-chromium (Co-Cr) removable partial
denture (RPD) wearers that aimed to investigate the effects of denture wearing on
oral tissues. A random sample of patients who had received their dentures 5-6
years previously from a dental teaching hospital in Hong Kong was selected. Those
who had been constantly wearing the RPDs were examined by one calibrated examiner
under an optimal clinical setting. The patients' dental, periodontal and mucosal
status were assessed. A total of 87 patients were examined. Mucosal lesions under
the Co-Cr RPDs were uncommon in this study sample. However, there was a high
prevalence of plaque, gingivitis and gingival recession, especially in dento
gingival surfaces in close proximity (within 3 mm) to the dentures. Thus, there
is a special need for regular oral hygiene reinforcement, scaling and prophylaxis
among RPD wearers. Despite a low caries incidence in the study sample, root
caries were found to be associated with contact with the RPDs (P < 0.05) but
coronal caries were not. It is recommended that coverage of the exposed root
surfaces by RPD components should be avoided. Also, topical fluorides should be
regularly applied onto exposed root surfaces as a preventive measure.
PMID- 10784330
TI - Degradation of repaired denture base materials in simulated oral fluid.
AB - This in vitro study evaluates the degradation of repaired denture bases upon
immersion in a simulated oral fluid. Denture base materials (Luciton 199), after
being repaired by Repair Material and Triad, using three different joint surface
designs (butt, round and 45 degrees bevel), were immersed onto 99.5 vol.%
ethanol/water solution (with similar solubility parameter) for various amounts of
time (0-72 h). The flexural loads of the six combination of groups were measured
by the three-point bending tests using a universal testing machine. Acoustic
emission (AE) during sample fracturing were processed using the MISTRA 2001
system. The fracture pattern and surface details of the interface were examined
with a scanning electronic microscope (SEM). Data were analysed using three-way
ANOVA and Tukey LSD tests. SEM micrographs of the fracture interface were used to
differentiate the fracture mode. The flexural loads (2.72 +/- 0.51 Kgf) of the
round joint specimens were significantly higher (P< 0.05) than those (butt: 1.66
+/- 0.38 Kgf, 45 degrees bevel: 1.93 +/- 0.41 Kgf) of the other two designs. This
corresponds to the microscopic examination in which more cohesive failure mode
was found for the round joint group after storage. The flexural loads (2.54 +/-
0.39 Kgf) of the specimens repaired with Triad were significantly higher (P <
0.05) than those (1.59 +/- 0.40 Kgf) of specimens repaired with Repair Material.
Significant progressive reduction of the flexural load and/or AE signals of the
specimens was noted in proportion to the length of time of the immersion in the
simulated oral fluid. Mechanical strength of a denture base repaired with a round
joint design and light-cured material is significantly higher after immersion in
simulated oral fluid.
PMID- 10784331
TI - Tooth loss and the condition of the prosthodontic appliances in a group of
elderly home residents.
AB - The study assessed the number of missing teeth, the state of the existing
prosthodontic appliances and the need for their replacement. Dental status and
anamnesis were taken on a group of 120 elderly home residents by trained
examiners. Prosthodontic appliances were evaluated according to the Karlsson's
index for the crowns and bridges, and according to the modified Nevalainen et al.
index for the evaluation of the complete dentures, as well as the need for
prosthetic treatment. The most persistent teeth in both jaws were lower canines,
while the most commonly missing teeth were lower first molars. On average, the
crowns were older and in poorer condition than the bridges. Lower complete
dentures had better stability but were also less retentive in comparison with the
upper complete dentures. More than 82% of the subjects were in need of either
fixed, removable or combined prosthodontic treatment. The high prevalence of
needs for prosthodontic treatment pointed to the requirement for frequent dental
check ups within elderly home residents in order to better identify and meet
their dental needs.
PMID- 10784332
TI - The effect of polishing systems on microleakage of tooth-coloured restoratives.
Part 2: composite and polyacid-modified composite resins.
AB - The purpose of this in vitro study was to investigate the effect of polishing
systems on the microleakage of composite and polyacid-modified composite resins.
Class V cavities were prepared at the cemento-enamel junction of 80 freshly
extracted posterior teeth. The prepared teeth were randomly divided into two
groups and restored with conventional or polyacid-modified composite resins. The
restored teeth were stored in distilled water at 37 degrees C for 1 week after
removal of excess restorative with diamond finishing burs. The restored teeth
were then divided into four groups of ten and finished/polished using the
following systems: Two Striper micron finishing system (MFS), Sof-Lex XT (Sof
Lex), Enhance composite finishing and polishing system (Enhance), and Shofu
composite finishing kit (Shofu). The finished restorations were subjected to dye
penetration testing. Results showed that the microleakage resistance at both
enamel and dentin margins of composite and polyacid-modified composite resins are
not significantly affected by the different polishing systems.
PMID- 10784333
TI - Reliability of some clinical parameters of evaluation in implant dentistry.
AB - Clinical tests that are commonly used to evaluate tissues surrounding natural
teeth are also used in implant dentistry. It is unclear if they are equally valid
and reflect the condition of the bone surrounding an implant reliably. This study
evaluates the use of a plaque index, a gingiva index, the assessment of a probing
depth and the Periotest value and relates the findings to the image on a
radiograph in 16 patients, involving 32 IMZ implants. All four clinical tests
showed poor sensitivity and, in general, only fair specificity when observations
from the image on the radiograph were interpreted as the 'golden standard' for
the presence or absence of pathology adjacent to the implant. Frequently, based
on any clinical parameter, disease was not diagnosed, while the radiograph did
show pathological loss of bone at the bone-implant contact area. It is concluded
that the aforementioned parameters are unreliable and unfit for clinical
evaluation in implant dentistry. Radiographs are needed to evaluate critical
marginal bone changes surrounding dental implants.
PMID- 10784334
TI - Intercondylar width as a guide to setting up complete denture teeth.
AB - A clinical study was designed to investigate the relationship between
intercondylar width (ICW) and inter-dental widths of the upper and lower canines
and first molars to aid in denture teeth positioning. The study was divided into
two parts so that the results of the first part could be verified in the second
part. In the first part, 27 adult subjects were selected according to the
exclusion criteria of the study. A kinematic hinge axis locator was used to
locate the true point of condylar rotation. The distance between these points was
considered to be the ICW. A strong correlation was found between ICW and
interdental measurements, with ICW and upper first molars being the strongest
(r=0.612, P= 0.004). A set of indices developed from the results was recommended
for the positioning of complete denture teeth. In the second part of the study,
inter-dental measurements were estimated using the indices obtained in the first
part. The estimated inter-dental widths showed no significant differences
compared with the real widths (P= 0.109, P=0.849, P=0.353, P=0.41). Based on the
results of this study, ICW measurements can be used for setting up canines and
first molars in complete dentures.
PMID- 10784335
TI - Wireless optoelectronic recordings of mandibular and associated head-neck
movements in man: a methodological study.
AB - Human mandibular movements in space are the result of combined motions of the
mandible and the head-neck. They can be simultaneously monitored by an
optoelectronic recording technique via markers at different locations on the
mandible and on the head. Markers can be attached to the teeth or to the facial
skin. Mandibular movements relative to the head can be calculated by one- or
three-dimensional (1D and 3D, respectively) mathematical compensation for head
movements. The present study analysed mandibular and associated head movements
during maximal jaw opening-closing tasks in 10 healthy subjects using a wireless
3D optoelectronic movement recording system. The study aimed to: (i) estimate the
soft tissue related displacement of skin-attached markers at different locations
on the face; (ii) compare 1D with 3D mathematical compensation for associated
head movements; (iii) evaluate the influence of marker location on the recorded
head and mandibular movement amplitudes; and (iv) compare skin-attached markers
with teeth-attached markers with regard to temporal estimates of recorded
mandibular and head movements. Markers were attached to the upper and lower
incisors and to the skin of the forehead, nose-bridge, nose-tip and chin. Soft
tissue related displacement of skin-attached markers varied between locations.
The displacement for the chin marker was larger than that of other markers. The
least displacement was found for the nose-bridge marker. However, relative to
mandibular and head movements, respectively, the displacement of the chin marker
was of the same order as that of the nose-bridge marker. The temporal estimates
were not significantly affected by displacement of the skin-attached markers.
Markers at different locations on the head and the mandible registered different
amplitudes. The mandibular movement patterns calculated by 1D and 3D compensation
were not comparable. It is concluded that markers attached to the chin and the
nose-bridge can be reliably used in temporal analyses of mandibular and head
movements during maximal jaw opening-closing. With certain limitations, they are
acceptable for spatial analyses. Selection of method of marker attachment, marker
location, and method of compensation for associated head movements should be
based on the aim of the study.
PMID- 10784336
TI - Influence of clenching level on intercuspal contact area in various regions of
the dental arch.
AB - The purpose of this study was to evaluate the relationship between the clenching
level and the intercuspal contact area in different regions of the dental arch.
Twenty-five healthy subjects with natural normal dentitions and good occlusal
support performed clenching tasks in the intercuspal position at four different
levels (10, 30, 70 and 100% levels of maximum voluntary contraction) through EMG
visual feedback from bilateral masseter and anterior temporal muscles.
Simultaneously, the occlusal contacts were recorded with a silicone occlusal
contact checking material (Black Silicone, GC Dental Industrial Corp., Tokyo,
Japan). The occlusal records were analysed by an image analyser. Every area of
the thickness less than 50 microm was determined to be an occlusal contact area.
The occlusal contact areas on the anterior teeth (incisors and canines), the
premolars (first and second premolars) and the molars (first and second molars)
were calculated separately. The posterior occlusal contact area increased with an
increase in the clenching levels but that of the anterior did not. The results of
this study indicate that the increase in clenching forces affects the anterior
and posterior occlusal contact areas differently.
PMID- 10784337
TI - Development of a new device for recording condylar head movement.
AB - Several excellent devices have recently been developed to precisely record
mandibular movement. However, these devices are not always suitable for use under
certain conditions, such as during sleep, because they incorporate a face bow
unit. We report here a newly developed, easy and convenient recording device that
does not require the use of an instrument within the mouth. Instead, a
subminiature pressure transducer is inserted between the outer surface of a
fixation device in the external auditory meatus and the anterior cutaneous
surface of the external auditory meatus. The fixation device was made using
silicone impression material in the shape of the inner external auditory meatus.
Following moulding, the material was cut in half and the parts were reconnected
using a coiled spring. This method is based on a routine clinical method for
palpating the external auditory meatus to observe condylar head movement. By
comparing the results obtained using this device with those obtained using
CADIAX, we confirmed that it is useful for recording the movement of the condylar
head in routine clinical examinations.
PMID- 10784338
TI - The effects of different additives on the dielectric relaxation and the dynamic
mechanical properties of urethane dimethacrylate.
AB - The polymer-filler interaction of a dental composite was examined by dielectric
measurements to determine how a non-compatible inorganic phase modifies the
molecular behaviour of the polymer chains and how modification of this phase by
silanation can affect these molecular behaviours. Urethane dimethacrylate (UDMA)
monomer and zirconia-silica (ZS) powder were used as organic and inorganic
phases, respectively. 3-Acryloxypropyltrimethoxysilane (MAPM) and 4
aminobutyltriethoxysilane (ABTE) were used as silanating coupling agents. The
components of the composite were mixed in different ratios after treating the
filler with from 0 to 30 times the minimum uniform coverage with the silane, then
the composite was made into thin films. The dielectric spectra of five replicas
for each filler-monomer ratio were measured, and three replicas were measured for
each silane and for each amount of silane used to treat the filler. Increasing
the filler concentration in the composites decreased the intensity of
Tan(delta)epsilon for the alpha- and beta-relaxations, where the beta-relaxations
also became broader and the alpha-relaxations were totally obstructed. The alpha
relaxations were shifted to higher temperatures, while the beta-relaxations were
shifted to lower temperatures. Filler treatment with small amounts of MAPM
shifted the alpha-relaxations to higher temperatures; they were shifted back to
lower temperatures when the filler was treated with large amounts of silane.
Filler treatment with large amounts of ABTE (30-fold) caused an extra peak to
emerge in the high-temperature region. It can be concluded that increasing filler
concentration restricts the mobility of the main chains and decreases the
thickness of the surface layer, while allowing more movement of the local chains.
Filler treatment with MAPM was shown to be a compatible coupling agent with the
ZS and the UDMA systems. Such compatibility was observed through the
effectiveness of the chemical linkage of the silane to the filler and the polymer
without forming a separate inter-phase. Filler treatment with ABTE was shown to
be an incompatible coupling agent for the ZS-filled UDMA system. The
incompatibility was observed by the occurrence of a new peak that characterizes
an inter-phase.
PMID- 10784339
TI - Streptococcus mutans in saliva of normal subjects and neck and head irradiated
cancer subjects after consumption of honey.
AB - The antibacterial activity of natural honey consumption has been examined in
patients suffering from head and neck cancer who developed hyposalivation
following irradiation treatment. Enumeration of total bacteria and streptococcus
mutans was carried out in saliva of the patients and of a normal volunteer group
before and after honey consumption. Total bacteria count was not significantly
different between both groups, whereas the streptococcus mutans count decreased
significantly in the experimental group following honey consumption.
PMID- 10784340
TI - Nuclear pore function viewed with atomic force microscopy.
AB - In this review we focus on studies using atomic force microscopy (AFM) to
describe the function of nuclear pore complexes (NPC). After a short introduction
of AFM we follow the route of cargo molecules from the cytosol into the nucleus.
AFM visualizes cargo before translocation into the nucleoplasm, cargo docking at
the cytoplasmic NPC surface, cargo passing through the NPC and changes in NPC
conformation in response to ATP, Calcium and pH. We discuss AFM experiments on
nuclear envelopes on the basis of previous data obtained with more conventional
techniques such as electron microscopy, confocal microscopy and other imaging
techniques. Finally we draw attention to the recently developed nuclear hourglass
technique that serves as a new electrophysiological approach to studying the
structure-function relationship of NPC in combination with AFM at a molecular
level.
PMID- 10784341
TI - NaCl transport deficiencies--hemodynamics to the rescue.
AB - Hereditary defects in the renal handling of filtered NaCl and water have
important implications for understanding the physiological mechanisms that enable
the kidney to optimize the match between glomerular filtration rate and tubular
reabsorption. Null mutations in the water channel aquaporin 1 (AQP1) or the Na/H
exchanger NHE3, two major fluid transporters in the proximal tubule, are states
in which a reduction in proximal fluid absorption is accompanied by proportionate
decrements in glomerular filtration rate. Compensation of the transport defect by
a reduction in filtered load is so efficient that clinically symptomatic Na
losses are not observed in either AQPI or NHE3 deficiency. On the other hand,
severe syndromes of salt wasting are caused by transport deficiencies in the
thick ascending limb or the collecting duct, indicating that the severity of Na
dysregulation is unrelated to the basal absorption of NaCl in a given nephron
segment. Loss of function of the Na,K,2Cl-cotransporter (NKCC2) or of the
epithelial Na channel (ENaC) reduces Na absorption in thick ascending limbs or
collecting ducts. In these states, the increased delivery of Na to downstream
segments is not monitored by a sensor linked to the site of filtrate formation.
In the absence of adaptations in the filtered load, intrarenal compensation of a
circumscribed NaCl malabsorption by adjustment of NaCl transport in other nephron
segments is remarkably insufficient, particularly in the immature kidney of the
newborn.
PMID- 10784342
TI - Effects of the dihydropyridine receptor subunits gamma and alpha2delta on the
kinetics of heterologously expressed L-type Ca2+ channels.
AB - Ba2+ currents through L-type Ca2+ channels were measured in tsA201 cells
transiently transfected with expression vectors encoding the dihydropyridine
(DHP) receptor subunits alpha1C, beta1a-GFP, alpha2delta and gamma. The subunit
effect on channel function was studied by omitting either alpha2delta or gamma
from the transfection mixture and analyzing the voltage dependence and kinetics
of activation, inactivation and recovery from inactivation. Activation could be
described by a single exponential function while the time course of inactivation
of the Ba2+ current followed a double exponential function. Progressively longer
depolarization led to increasingly slower recovery, indicating the successive
occupancy of several inactive states. Activation parameters remained largely
unaffected in y-deficient cells whereas the voltage dependence of inactivation
was shifted by 16 mV to more positive potentials and the larger one of the two
inactivation time constants was increased by one-third. On the other hand,
alpha2delta-deficient cells showed decreased current density and slowed
activation and inactivation. Recovery from inactivation was significantly slowed
by gamma coexpression. This and the effect of the gamma subunit on steady-state
inactivation were independent of the presence of alpha2delta. We conclude that y
stabilizes L-type Ca2+ channel inactivation in a way similar to certain Ca(2+)
antagonistic drugs. Alpha2delta is not needed for this effect.
PMID- 10784343
TI - Inhibition of apamin-sensitive K+ current by hypoxia in adult rat adrenal
chromaffin cells.
AB - The effect of hypoxia on small-conductance Ca(2+)-activated K+ current was
investigated in a study of adult rat adrenomedullary chromaffin cells (AMCs),
which were maintained in short-term culture. The nystatin-perforated, whole-cell
patchclamp technique was used to study the effect of hypoxia with minimum
perturbation of the intracellular milieu. Under voltage-clamp conditions, acute
hypoxia (P(O2) approximately equal to 25 mmHg) suppressed the whole-cell outward
currents of more than half the AMCs (24/46). This suppression was eliminated
after application of apamin (400 nM), a selective inhibitor of small-conductance
Ca(2+)-activated K+ current (I(SK)(Ca)) (n=5), suggesting that an apamin
sensitive component of whole-cell currents is suppressed during hypoxia. In
contrast to I(SK)(Ca), Ca2+ current (I(Ca)) (n=10) was not affected by hypoxia.
Finally, under current-clamp conditions, hypoxia reversibly depolarized the
resting membrane potential of adult AMCs (34/40). Apamin, however, eliminated the
hypoxia-induced depolarization (400 nM) (7/8), suggesting that hypoxic
depolarization is related to the suppression of I(SK(Ca). From the above results,
we conclude that adult AMCs are sensitive to hypoxia, and that I(SK)(Ca)
contributes to the hypoxia-induced suppression of whole-cell outward current and
depolarization of the resting membrane potential in adult AMCs.
PMID- 10784344
TI - Modification of wild-type and batrachotoxin-resistant muscle mu1 Na+ channels by
veratridine.
AB - Biochemical evidence indicates that veratridine (VTD) and batrachotoxin (BTX)
share a common binding site in Na+ channels. Under whole-cell voltage-clamp
conditions, we examined this single receptor hypothesis by studying the VTD
phenotype in BTX-resistant muscle Na+ channels, microl-I433K, N434K, L437K,
F1579K, and N1584K. Derived from point mutations at segments D1-S6 and D4-S6,
these mutant Na+ channels are resistant to 5 microM BTX when expressed in human
embryonic kidney cells. In contrast to the wild-type phenotype, VTD at 200 microM
elicits little or no maintained current during a test pulse at +50 mV, and little
or no "tail" current after the test pulse in all BTX-resistant mutant channels.
Paradoxically, VTD retains its ability to inhibit the peak Na+ current in BTX
resistant mutant Na+ channels. To explain these mutant phenotypes, we propose a
two-step binding reaction scheme. An initial VTD-binding interaction with the Na+
channel results in the inhibition of peak current amplitude, and a second binding
reaction results in the trapping of VTD within the D1-S6 and D4-S6 domain
interface. The failure of BTX-resistant mutant Na+ channels to trap VTD suggests
that segments of D1-S6 and D4-S6 form a common receptor for VTD and BTX.
PMID- 10784345
TI - Cloning, localisation and functional expression of the human orthologue of the
TREK-1 potassium channel.
AB - We have cloned human TREK-1, one of the newly emerging mammalian family of 2-P
domain potassium channels. The channel has 411 amino acids with a 41-amino-acid
extension at the C-terminus when compared with the cloned mouse TREK-1 channel.
Expression of hTREK-1 produced a substantial hyperpolarising shift in resting
membrane potential accompanied by the induction of large, outwardly rectifying,
non-inactivating currents which were potassium selective. Pharmacologically,
hTREK-1-mediated currents were only blocked to a limited extent by classic
potassium channel blockers or open channel pore blockers known to potently
inhibit other channels. The channel was reversibly potentiated by arachidonic
acid. CNS distribution of hTREK-1 is widespread with higher levels being observed
in caudate, putamen, amygdala, thalamus and spinal cord. Only low levels of
expression were seen in the majority of peripheral regions. Thus, hTREK-1,
although functionally and pharmacologically similar to mouse TREK-1, appears to
have a more CNS-specific distribution.
PMID- 10784346
TI - Downregulation of skeletal muscle UCP-3 gene expression during refeeding is
prevented by cold exposure.
AB - We wished to gain insights into the role of skeletal muscle uncoupling protein-3
(UCP-3) in the elevated efficiency of fat recovery during refeeding after
starvation. Previous observations have revealed that muscle UCP-3 expression is
downregulated in rats during refeeding at 22 degrees C. Therefore, we
investigated whether this also occurs during refeeding at thermoneutrality (29 C)
or in the cold (6 C), since at these environmental temperatures the refed animals
also show diminished thermogenesis and a higher rate of fat deposition than
controls. The UCP-3 mRNA level in the skeletal muscles studied (soleus,
gastrocnemius and tibialis anterior) was significantly lower in the refed group
than in controls at thermoneutrality, but there were no such differences between
these two groups in the cold. This effect of cold, namely abolishing refeeding
induced downregulation of skeletal muscle UCP, is specific to UCP-3 since the
gene expression of skeletal muscle UCP-2 remained significantly lower in the
refed than in the controls both at thermoneutrality and in the cold. These
findings during refeeding in the cold therefore dissociate UCP-3 gene regulation
from the adaptive reduction in thermogenesis that accelerates fat deposition
during weight recovery. They also reveal differential responses of UCP-3 and UCP
2, whose significance is discussed in the light of our previously proposed
hypothesis, which centers upon a role for these UCP homologues in the regulation
of lipids as a fuel substrate.
PMID- 10784347
TI - Particle-mediated gene transfer to rat neurons in primary culture.
AB - Gene transfer into neuronal cells provides an important approach to study their
function. Particle-mediated gene delivery was used to transfect rat dorsal root
ganglion (DRG) and hippocampal neurons in primary culture with the genes for the
enhanced blue and green fluorescent proteins (EBFP and EGFP) under control of the
cytomegalovirus promoter. Quantitative analysis of marker protein fluorescence
detected expression at 3 h that continued to increase for 48 h. For DRG neurons
the optimal expression efficiency of 8+/-2% was obtained 24 h following
transfection. In contrast, approximately 2+/-1% of hippocampal neurons in culture
expressed EGFP at 3 h which subsequently declined. Co-transfection of DRG
cultures with two plasmids produced reliable expression of both genes.
Transfected DRG neurons exhibited normal electrophysiological properties, and
resting and stimulated intracellular Ca2+ concentrations were unchanged. After
transfection, 44% of hippocampal neurons remained in functional synaptic networks
as indicated by glutamatergic Ca2+ spiking activity. Particle-mediated gene
delivery provided a straightforward, reproducible and efficient method for
transfection of neurons in primary culture. Transfected cells were easily
identified by EGFP fluorescence, enabling subsequent physiological analysis.
Biolistic particle bombardment was well tolerated by peripheral neurons, although
caution was required when this method was applied to CNS cultures.
PMID- 10784348
TI - The effect of external pH on the delayed rectifying K+ current in cardiac
ventricular myocytes.
AB - The effects of extracellular pH (pHe) on the delayed rectifying K+ current iKr in
rabbit ventricular myocytes were studied using the whole-cell-clamp technique.
Since a variety of results have been reported on the effect of pH on expressed
hERG channels, our aim was to investigate the effects of pH on iKr channels in
their native environment. iKr is reduced by extracellular acidification and its
deactivation is faster. Extracellular acidification results in a marked shift of
the steady-state activation curve to more positive potentials, while
alkalinization does not produce a significant shift. E1/2= - 11.3 mV, -20.2 mV,
21.4 mV at pHe 6.5, 7.4, 8.5 respectively; the slope factor is 6.2 mV, and is not
affected by pHe. Deactivation of iKr is biexponential, with time constants of the
order of 0.5 s and 10 s at -50 mV. Both time constants decrease with external
acidification. Also the contribution of the fast component to the total amplitude
becomes larger with acidification. Acidification also decreases the fully
activated iKr current. Our experiments demonstrate that extracellular
acidification reduces iKr by increasing the rate of deactivation, causing a shift
of the voltage dependence of activation and producing a voltage-dependent block
of the fully activated iKr current.
PMID- 10784349
TI - Functional integrity of endothelium determines Ca2+ channel availability in
smooth muscle: involvement of nitric oxide.
AB - Endothelium regulates smooth muscle contractility in part via nitric oxide (NO).
We tested the hypothesis that endothelial dysfunction, either produced by injury
or simulated pharmacologically by reducing the bioavailability of NO, results in
elevated Ca2+ channel availability (ngmax=maximum conductance/cell capacitance)
in smooth muscle cells isolated from the vessel. Using basilar arteries of
normotensive Wistar rats, we measured ngmax in smooth muscle cells from control
vessels, from vessels in which endothelium was injured using Na fluoroscene plus
light, and from vessels in which the bioavailability of NO was reduced by
pretreatment with the NO scavenger 1H-imidazol-1 -yloxy,2-(4-carboxyphenyl)-4,5
dihydro-4,4,5,5-tetramethyl-3-oxide , potassium salt (C-PTIO), or the endothelial
nitric oxide synthase (eNOS) inhibitor N(G)-nitro-L-arginine methyl ester (L
NAME). Values of ngmax in these four groups of cells were 0.28+/-0.02 nS/pF
(n=22), 0.51+/-0.05 nS/pF (n=15), 0.430+/-.03 nS/pF (n=12), and 0.47+/-0.04 nS/pF
(n=14) (P<0.05, ANOVA), respectively. To determine whether larger currents
associated with endothelial dysfunction exhibit altered sensitivity to exogenous
NO, we quantified the response to various concentrations of NO donor, Na
nitroprusside (SNP), in 37 cells from control vessels and 33 cells from vessels
pretreated with L-NAME. SNP exhibited identical potency (half-maximum values,
18.7 and 21.1 nM) but greater apparent efficacy (maximum fractional block, 0.82
versus 0.63) in down-regulating Ca2+ channel currents in cells isolated from
vessels with dysfunctional endothelium. Our results are consistent with a direct
influence of endogenous NO on Ca2+ channel availability in smooth muscle cells,
and indicate that Ca2+ channel availability in isolated smooth muscle cells may
be a sensitive measure of the functional integrity of the endothelium in the
parent vessel.
PMID- 10784350
TI - Chloride channels in the plasma membrane of a foetal Drosophila cell line, S2.
AB - We evaluated the suitability of the S2 foetal Drosophila cell line as an
expression system for vertebrate anion channel proteins (e.g. cystic fibrosis
transmembrane conductance regulator, CFTR) in patch-clamp studies of the
endogenous ion channels. In the inside-out configuration (symmetric 150 mM Cl-)
we found most frequently an inwardly rectifying Cl- channel with single-channel
conductances (gamma) of 57, 45 and 17 pS at -80, 0 and 80 mV, respectively.
Reduction of bath [Cl-] to 40 mM caused a shift in reversal potential (Vrev) to
22.5 mV indicating pronounced Cl- selectivity. In the outside-out configuration
([Cl-]pipette = 40 mM, [Cl-]bath = 150 mM) we observed a Cl- channel with a
linear unitary current/voltage (i/V) relation for which gamma was 30 pS. The
kinetics were quite slow in both configurations. Cl-selectivity was also observed
in whole-cell experiments ([Cl-]pipette = 40 mM) in which a Vrev of -43.8 mV,
i.e. close to the Cl- equilibrium potential, demonstrated that the membrane
current was dominated by Cl-. We conclude that the important features making S2
cells suitable as an expression system for heterologous expressed anion channel
proteins are: small total whole-cell currents (less than 100 pA), single-channel
and whole-cell currents that, unlike those of CFTR, cannot be described by the
Goldman-Hodgkin-Katz regime, and slow kinetics distinctly different from those of
CFTR.
PMID- 10784351
TI - Cellular adaptation of the mouse cortical thick ascending limb of Henle's loop
(CTAL) to dietary magnesium restriction: enhanced transepithelial Mg2+ and Ca2+
transport.
AB - Mice aged 4 or 8 weeks were fed with a low-Mg2+ diet for 1, 2, 3 or 4 days. After
1 day of diet, the urinary excretion of Mg2+ and Ca2+ was strongly reduced in
both animal groups (4 and 8 weeks), accompanied by a significant fall in plasma
Mg2+ concentration and an increase in urinary volume. This profile persisted
after 2, 3 or 4 days of dietary Mg2+ restriction. After 1 day of diet,
transepithelial ion net fluxes of Na+, Cl-, Ca2+ and Mg2+ (JNa' JCI, JCl, JMg)
measured in vitro from isolated perfused cortical thick ascending limbs (CTALs)
of these animals remained unchanged. After 2 days of diet, measurements of J(Ca)
and J(Mg) in isolated perfused CTALs showed that transepithelial Mg2+ and Ca2+
reabsorption were enhanced in CTALs from Mg(2+)-depleted, 8-week-old animals,
whereas transepithelial Mg2+ and Ca2+ transport were not altered in 4-week-old
mice. JNa and JCl and the transepithelial potential (PDte) were not modified in
CTALs from either animal group. Our results suggest that a low-Mg2+ diet leads to
urinary retention of Mg2+ and Ca2+ which is most likely due to increased Mg2+ and
Ca2+ transport in the CTAL. Furthermore, in response to dietary Mg2+ restriction,
the reabsorption of divalent cations in the CTAL of adult, but not of young, mice
undergoes cellular adaptation.
PMID- 10784352
TI - Impact of pulse pressure on the respiratory-related arterial pressure variability
and its autonomic control in the rat.
AB - The autonomic control of respiratory-related arterial pressure variability (RAPV)
remains uncharacterised. We set out to test the hypothesis that the autonomic
nervous system may participate in RAPV via its effect on pulse pressure (PP).
Experiments were performed on adult male Sprague-Dawley rats anaesthetised with
ketamine and paralysed with pancuronium under positive-pressure ventilation.
Respiratory variability in each parameter was quantified by auto-spectral
analysis and the relationship between variabilities in two signals assessed by
cross-spectral analysis. PP and systolic pressure (SP) exhibited similar powers
of respiratory variability that were far more pronounced than for diastolic
pressure (DP) or mean pressure (MP). The variability in PP preceded that in SP,
MP or DP. The largest phase lag occurred between PP and DP and was equivalent to
the time delay of one pulse interval. Coherence between respiratory variabilities
in PP and MP was nearly perfect. Propranolol dose dependently suppressed
respiratory variability in each pressure parameter and eventually disrupted the
PP-MP relationship in respiratory variability. However, the influence of lung
volume on MP persisted with a near-zero phase lag. Combined administration of
phentolamine and atropine facilitated respiratory variability in PP and SP and
failed to block the effect of propranolol. However, the combined administration
moved the dose/response curve of propranolol and respiratory variability in each
pressure parameter to the right. We conclude that, in addition to non-autonomic
mechanisms, RAPV may be facilitated by cardiac sympathetic function via the
effect on PP variability. The autonomic mechanism can still be evoked during
combined alpha-adrenoceptor and muscarinic blockade, possibly via baroreflex
mechanisms.
PMID- 10784353
TI - Rapid gene transcription induced by stretch in cardiac myocytes and fibroblasts
and their paracrine influence on stationary myocytes and fibroblasts.
AB - Functional adaptation of cardiac cells in response to haemodynamic load requires
dynamic alteration of gene expression. In this study, we examined early changes
in gene expression following stretch in myocytes and fibroblasts isolated from
neonatal rat hearts. In the first hour of biaxially applied static stretch, the
changes in expression of immediate-early genes, such as c-fos, c-jun and fra-1,
were quantified. The expression of the atrial natriuretic peptide (ANP) gene in
myocytes was measured as an indication of the hypertrophic response. In stretched
myocytes, expression of c-fos and ANP increased transiently to 227% and 176%
respectively after 30 min stretch, whereas c-jun and fra-1 expression decreased
in the 1st hour of stretch. In stretched fibroblasts the expression of c-fos and
fra-1 increased transiently to maxima of 145% and 146% respectively after 30 min
stretch, whereas c-jun expression did not change significantly. To study the
indirect effects of stretch, as an indication of cross-talk between cardiac
cells, stationary myocytes and fibroblasts were incubated with stretch
conditioned medium (CM) from stretched (0-60 min) myocytes and fibroblasts. CM
from stretched myocytes reduced c-fos and induced c-jun expression in myocytes
and fibroblasts, reduced fra-1 expression in myocytes but induced fra-1
expression in fibroblasts. CM from stretched fibroblasts induced c-fos expression
and had little effect on c-jun expression in myocytes and fibroblasts, induced
the fra-1 expression in myocytes but had little effect on fra-1 expression in
fibroblasts. CM from myocytes and CM from fibroblasts induced ANP expression in
myocytes to 206% and 120% respectively after 45 min stretch. Static stretch of
myocytes and fibroblasts appears to stimulate, within 1 h, secretion of cell type
specific factors that participate in the regulation of proto-oncogene and ANP
expression of stationary myocytes and fibroblasts. These early changes in gene
transcription suggest that stretch of the myocardium initiates intracellular gene
expression as well as cross-talk between the cell types.
PMID- 10784354
TI - Role of architecture in determining passive electrical properties in gap junction
connected cells.
AB - The electrical properties of gap junction-connected cells were analysed in terms
of their architectural organization. Two major architectural categories were
considered: trees and rings. Trees are described by means of Bethe lattices
(lattices with no rings) with arbitrary co-ordination and rings by two
dimensional periodic lattices with fourfold (square) or sixfold (triangular) co
ordination. The Bethe lattice is solved analytically by the transfer constant
method, which allows the introduction of several physiologically relevant effects
in a very simple manner. The experimental data for the length constant and the
input resistance were fitted by varying the coupling and membrane resistances for
various morphologies. The large variations in the length constant observed
experimentally in two systems (turtle retina horizontal cells with and without
dopamine and pancreatic beta-cells in the active and silent phases) could not be
explained by means of the Bethe lattice, indicating that the cell arrangements
form rings. Subsequent analysis by means of a linear chain and the square and
triangular lattices showed the crucial relevance of architecture in deriving the
electrical characteristics of gap junction-connected cells from experimental
data.
PMID- 10784355
TI - Outwards currents in embryonic stem cell-derived cardiomyocytes.
AB - The aim of the present study was to investigate the expression and functional
role of outwards currents during the early stages of cardiomyogenesis. The
predominant repolarizing current in early-stage, embryonic stem (ES) cell-derived
cardiomyocytes was a 4-aminopyridine (4-AP) sensitive [concentration for half
maximal inhibition (IC50) 1.7 mM], transient outward current (Ito) with a current
density of 10.3+/-2.1 pA/pF (n=72). We observed two additional, rapidly
activating, outwardly rectifying current components, I(K),sus and Ires, in early-
and late-stage cardiomyocytes. These currents were characterized by slow and no
inactivation, respectively, during the depolarizing voltage step. I(K),sus was
detected in about 25% of cells investigated and displayed 4-AP hypersensitivity
(IC50 29 microM), whereas Ires was found in all cells of both differentiation
stages and was 4-AP insensitive. In contrast to early-stage cells, Ires formed
the larger portion of the aggregate, whole-cell current in late-stage, ES cell
derived cardiomyocytes. The current densities of all three current components
increased during development, however, the most prominent increase was observed
for I(res) from 3.6+/-0.8 pA/pF (n=72) to 8+/-1.1 pA/pF (n=35). In current-clamp
recordings in early-stage, spontaneously contracting cardiomyocytes, 4-AP
depolarized the cells, lengthened the action potential duration (APD) and
increased the action potential frequency. In late-stage cells 4-AP had no effect
on action potential frequency. We conclude that in early-stage cardiomyocytes
I(to) plays an important role in controlling electrical activity.
PMID- 10784356
TI - Effect of anoxic preconditioning on ATP-sensitive potassium channels in guinea
pig ventricular myocytes.
AB - Ischemic or hypoxic preconditioning in experimental animals and humans is
described. The mechanism of preconditioning may involve several endogenous
substances released from ischemic or hypoxic tissues (such as adenosine,
noradrenaline and bradykinin) that stimulate protein kinase C (PKC), which then
phosphorylates ATP-sensitive potassium channels (K(ATP) channels). However, the
effect of hypoxic preconditioning on K(ATP) channels in guinea-pig ventricular
myocytes is unclear. The uncoupler carbonyl cyanide p
(trifluoromethoxy)phenylhydrazone (FCCP) has been shown to activate K(ATP)
channels in isolated cardiac cells. In the present study we tested whether anoxic
preconditioning (APC) could affect the opening of K(ATP) channels activated by
metabolic inhibition (MI) induced by FCCP in cell-attached and inside-out patches
from guinea-pig ventricular myocytes. We measured the channel activity as NP(o)i
and calculated it using the formula Po=I/(Ni), where Po is open-state
probability, I is the mean patch current carried by all K(ATP) channels activated
in a particular patch for a certain period of time, N is the number of
functioning channels in the patch, and i is the unitary current of the K(ATP)
channels. In cell-attached membrane patches, after about 5 min of initiating MI,
K(ATP) channels were activated at a holding potential of +40 mV (NP(o)i=3.70+/
0.9 pA); APC pretreatment (3 min of anoxia followed by 7 min of reoxygenation)
before MI (APC+MI group) shortened the time to activate K(ATP) channels by MI
(2.3+/-0.5 min) and increased the activity of K(ATP)currents (NP(o)i=8.4+/-0.5
pA). This effect of APC was eliminated by administration of a PKC blocker,
chelerythrine (5 microM), for 5 min before the APC pretreatment. In the inside
out patches, the IC50 of intracellular ATP against the K(ATP) channels in the
APC+MI group was significantly increased to 642 microM compared to that in the MI
group (IC50 of intracellular ATP =252 microM). Chelerythrine inhibited the effect
of APC on the sensitivity of K(ATP) channels to the intracellular ATP
concentration (IC50 of [ATP]i=301 microM). Our results demonstrate that APC can
increase and accelerate the opening of K(ATP) channels induced by MI, and
decrease the sensitivity of K(ATP) channels to [ATP]i, which is mediated by
promoting the activation of PKC induced by APC.
PMID- 10784357
TI - Lidocaine alters activation gating of cardiac Na channels.
AB - The class IB antiarrhythmic drug, lidocaine, interacts strongly with depolarized
sodium (Na) channels, an action that is thought to underlie its clinical
efficacy. Previously, we have reported Na channel gating current (Ig) experiments
with a quaternary form of lidocaine, QX-222, which binds preferentially to open
Na channels and modifies the gating-charge/voltage (Q/V) relationship of cardiac
Na channels by reducing maximal gating charge (Qmax) and lessening its voltage
dependence. We report here investigations with lidocaine itself on Ig of native
canine and cloned human cardiac Na channels. Although the state dependence of
lidocaine binding to Na channels differs from that of quaternary drugs, Ig
measurements demonstrated that lidocaine produced changes in the Q/V
relationships similar to those elicited by QX-222, with a reduction in Qmax by
33% and a corresponding decrease in the slope factor. Concentration/response
curves for the reduction in gating charge by lidocaine matched those for the
block of sodium current (I(Na)), as would be expected if modification of Na
channel voltage sensors by lidocaine underlied its action. The application of
site-3 toxins, which inhibit movement of the voltage sensor associated with
inactivation, to lidocaine-bound Na channels elicits an additional reduction in
Qmax suggesting that lidocaine does not "stabilize" the Na channel in an
inactivated state. We conclude that lidocaine blocks I(Na) by modification of the
Na channel's voltage sensors predominately associated with channel activation
leading to channel opening.
PMID- 10784358
TI - Stimulation of Na/Ca exchange by the beta-adrenergic/protein kinase A pathway in
guinea-pig ventricular myocytes at 37 degrees C.
AB - We investigated the effect of beta-adrenergic stimulation on Na/Ca exchange in
whole-cell patch-clamped guinea-pig ventricular myocytes at 37 degrees C. With
ion channel and Na/K pump currents blocked, the Na/Ca exchange current (I(Na-Ca)
was measured selectively as membrane current inhibited by 10 mM nickel (Ni)
during a voltage ramp applied between +80 and -120 mV. Isoprenaline (1 microM)
caused an increase in both inward and outward current generated by the Na/Ca
exchange, which was prevented by the beta-adrenoceptor blocker propranolol. These
data suggest that isoprenaline caused a receptor-mediated up-regulation of Na/Ca
exchange activity. Mimicking beta-adrenoceptor activation, either by stimulation
of adenylate cyclase with forskolin or by internal dialysis of cells with cyclic
AMP (3':5'-cyclic adenosine monophosphate), also increased I(Na-Ca). Using
fluorescence Ca measurement, an increase of internal cAMP was shown to increase
the rate of transmembrane Ca transport via the Na/Ca exchange. A selective
inhibitor of protein kinase A prevented stimulation of Na/Ca exchange by
isoprenaline. These data suggest that the underlying mechanism of stimulation was
phosphorylation of the Na/Ca exchange protein by protein kinase A. Isoprenaline
did not stimulate I(Na-Ca) when experiments were carried out at 20 degrees C, in
contrast to the findings at 37 degrees C. Modulation of Na/Ca exchange by the
beta-adrenergic pathway may have important physiological consequences for
intracellular Ca regulation and electrical activity during hormonal stimulation,
or during sympathetic nerve stimulation.
PMID- 10784359
TI - Dendrimer-assisted patch-clamp sizing of nuclear pores.
AB - Macromolecular translocation (MMT) across the nuclear envelope (NE) occurs
exclusively through the nuclear pore complex (NPC). Therefore, the diameter of
the NPC aqueous/electrolytic channel (NPCC) is important for cellular structure
and function. The NPCC diameter was previously determined to be approximately
equal to 10 nm with electron microscopy (EM) using the translocation of colloidal
gold particles. Here we present patch-clamp and fluorescence microscopy data from
adult cardiomyocyte nuclei that demonstrate the use of patch-clamp for assessing
NPCC diameter. Fluorescence microscopy with B-phycoerythrin (BPE, 240 kDa)
conjugated to a nuclear localization signal (NLS) demonstrated that these nuclei
were competent for NPC-mediated MMT (NPC-MMT). Furthermore, when exposed to an
appropriate cell lysate, the nuclei expressed enhanced green fluorescence protein
(EGFP) after 5-10 h of incubation with the plasmid for this protein (pEGFP, 3.1
MDa). Nucleus-attached patch-clamp showed that colloidal gold particles were not
useful probes; they modified NPCC gating. As a result of this finding, we
searched for an inert class of particles that could be used without irreversibly
affecting NPCC gating and found that fluorescently labeled Starburst dendrimers,
a distinct class of polymers, were useful. Our patch-clamp and fluorescence
microscopy data with calibrated dendrimers indicate that the cardiomyocyte NPCC
diameter varies between 8 and 9 nm. These studies open a new direction in the
investigation of live, continuous NPC dynamics under physiological conditions.
PMID- 10784360
TI - Dose-dependent effect of angiotensin II on human erythropoietin production.
AB - Current evidence suggests that angiotensin II may be involved in the regulation
of renal erythropoietin (EPO) production. The present study assessed the role of
angiotensin II (A II) in different doses in the control of EPO production in
humans. In a parallel, randomized, placebo-controlled open design, 60 healthy
male volunteers received a 6-h intravenous infusion of: placebo (placebo,
electrolyte solution), a pressor dose of A II (1-3 microg/min; A II press), a
combination of a pressor dose of A II and the selective AT1-receptor blocker
losartan, 50 mg (A II press + L), a subpressor dose of A II (0.0375-0.15
microg/min; A II subpress) and a combination of a subpressor dose of A II and
losartan (A II subpress + L). A II press treatment resulted in a significant
increase of the maximum EPO concentration (CmaxEPO, 41% higher versus placebo)
and the amount of EPO produced in 24 h (AUCEPO(0-24 h), 61% larger versus
placebo), A II subpress treatment increased CmaxEPO (35% higher versus placebo)
and AUC(EPO)(0-24 h) (34% larger versus placebo). A II press + L and A II
subpress + L treatments did not significantly increase CmaxEPO and AUCEPO(0-24 h)
compared to placebo. A II affects EPO production in a dose-dependent manner. The
signal seems to be mediated via AT1-receptors. A II appears to be one modulator
EPO production in humans.
PMID- 10784361
TI - Ca2+-activation characteristics of single fibres from chemically skinned rat
muscle incubated with glucose-6-phosphate.
AB - In this study we examined the effects of 3-24 h of incubation of chemically
skinned rat fast-twitch muscle with the glycolytic metabolite glucose 6-phosphate
(G6-P) on the contractile properties and myosin ATPase activity in single muscle
fibres, and on the carbohydrate content of myosin heavy chains (MHCs). Exposure
of the permeabilised muscle to 10 mM G6-P for 24 h at 22+/-1 degrees C in a rigor
solution containing protease inhibitors and a reducing agent (dithiothreitol,
DTT) significantly decreased maximum Ca(2+)-activated force output by 31%,
lowered the Ca2+ threshold for contraction by 0.1 pCa units and produced
shallower force-pCa curves compared with controls. Furthermore, under these
conditions, G6-P-treated muscle displayed lower myofibrillar MgATPase activity
and a markedly higher carbohydrate content of MHCs, as identified with an
immunoblot protocol for glycoprotein detection. Shorter incubations under the
same conditions or 24-h incubations with 5 mM G6-P generally resulted in smaller
changes in the contractile activation parameters. These findings suggest that
reducing sugars acting as metabolic intermediates in the glycolytic pathway can
have important non-energy-related effects on the contractile activation
characteristics of mammalian skeletal muscle. These effects are consistent with
the glycation of muscle proteins, in particular that of the MHC.
PMID- 10784362
TI - Heparin-induced extracorporal low-density-lipoprotein precipitation (H.E.L.P.) to
improve the recovery of hearing in patients with sudden idiopathic hearing loss.
AB - The pathogenesis of sudden hearing loss (SHL) is still not well understood.
Possible causes include increased blood viscosity, microthrombosis or altered
blood flow. Hypercholesterolemia, hyperfibrinogenemia and increased platelet
aggregation are frequently observed in patients with SHL. The aim of this study
was to investigate whether drastic lowering of plasma cholesterol and fibrinogen
by selective extracorporal apheresis could have a beneficial effect on hearing
recovery in these patients. Seven patients with SHL were treated with an
extracorporal procedure removing fibrinogen and cholesterol from plasma. Six of
the seven patients showed an immediate improvement in auditory thresholds
following a single treatment of heparin-induced low-density lipoprotein
precipitation. These findings indicate for the first time that acute and drastic
removal of plasma fibrinogen and low-density lipoproteins may be an effective
clinical method for the treatment of patients with SHL.
PMID- 10784363
TI - A Dutch family with progressive sensorineural hearing impairment linked to the
DFNA2 region.
AB - We studied a Dutch family with DFNA2-linked progressive sensorineural hearing
impairment (SNHI). Recent audiograms were obtained from 18 of the affected
persons (age 7-81 years) and were used in a gene-linkage analysis. Linear
regression analysis of the audiograms, using binaural mean thresholds, disclosed
on average a descending slope of approximately 10 dB/octave at any age and an
annual threshold increase at any frequency of about 0.7 dB/year. There may have
been substantial congenital impairment at higher frequencies, but longitudinal
analysis of hearing impairment in the youngest case, who was followed from age 5
years, suggested that the most significant changes in hearing may have occurred
in the first two decades of life. Linkage analysis was carried out with special
attention to the DFNA2 region because hearing trends were very similar to
families previously linked to DFNA2. Linkage to DFNA2 was established with
maximum lod scores of 4.7 and 3.2 for the flanking markers of the DFNA2 region
(D1S432;MYCL1).
PMID- 10784364
TI - Preliminary experiences with contact endoscopy of the larynx.
AB - Nine patients with laryngeal polyps, four with Reinke's edema, three with
leukoplakia, one with papilloma and one with malignant tumor were studied by
means of laryngeal contact endoscopy during microlaryngoscopy. This technique
allowed in vivo and in situ visualization of the superficial layer of the
laryngeal epithelium after staining with methylene blue. Cell structures
evaluated were the size and color of the nuclei, the nucleus/cytoplasm ratio,
nuclear and cytoplasmic contours, the presence of nucleoli, mitoses and
keratoses, as well as the microvascular network of the mucosa and superficial
cellular changes from normal to pathological. The normal squamous epithelium of
the vocal cord showed a homogeneous cellular population with regular nuclear and
cytoplasmic morphological characteristics and a uniform nucleus-to-cytoplasm
ratio. Specific cellular epithelial patterns and several alterations of the
vascular distribution were found in different pathological conditions.
Cytological pictures obtained at contact endoscopy were consistent with
histological findings in all the patients studied.
PMID- 10784365
TI - How much does it cost to preserve a larynx? An economic study.
AB - Various studies report an increase in costs when induction chemotherapy is
included in the treatment of advanced laryngeal cancer, but to our knowledge no
studies have yet compared the economic costs of total laryngectomy versus
induction chemotherapy in the treatment of advanced laryngeal cancer. We have
conducted a retrospective study comparing the costs of treatment and survival in
96 patients with a T3N0-1 glottic carcinoma. Findings showed that the average
cost per patient in the group of patients treated by total laryngectomy with or
without postoperative radiotherapy was 5,853 Eur, while that for the group of
patients who began treatment with induction chemotherapy was 6,452 Eur. The
adjusted 5-year survival for patients treated with total laryngectomy with or
without postoperative radiotherapy was 80%, and 72% for patients who began
treatment with induction chemotherapy. Sixteen of the 35 patients (46%) receiving
induction chemotherapy were spared laryngectomy. The use of induction
chemotherapy in the treatment of patients with advanced laryngeal carcinomas
involved an increase in cost of 600 Eur in relation to treatment with total
laryngectomy and postoperative radiotherapy. However, from an economic point of
view, we consider induction chemotherapy to be an important consideration in an
organ-preservation strategy.
PMID- 10784366
TI - Squamous cell carcinoma of the lower lid in a 19-month-old girl with xeroderma
pigmentosum.
AB - Squamous cell carcinoma (SCC) of the skin usually occurs in older patients and
commonly develops from actinic keratosis. Patients with xeroderma pigmentosum
(XP) can acquire SCC at an early age. To our knowledge the youngest reported
patient with XP and SCC was 8 years of age. We report a 19-month-old Lebanese
girl with XP who presented clinically because of a rapidly growing mass of the
medial part of her right lower lid that was biopsied and found to be squamous
cell carcinoma. The mass was surgically excised with no evidence of recurrence
after 2 years of follow-up. We describe our clinical experiences with this
patient and have reviewed the available literature concerning XP and malignancy.
PMID- 10784367
TI - Social class of origin and cardinal symptoms of schizophrenic disorders over the
early illness course.
AB - BACKGROUND: This study describes the relationship of social class of origin to
cardinal symptoms of schizophrenic disorders over the early illness course.
METHOD: The sample of subjects was drawn from the Suffolk County Mental Health
Project, a longitudinal epidemiologic study of first-hospitalized subjects with
psychotic disorders; the present study focused on patients with schizophrenic
disorders. At baseline, subjects were dichotomized into upper/middle and lower
social class of origin groups, based on occupation of the head of the household
of origin. The patients in both groups were assessed for the major symptoms of
schizophrenic disorders using standard structured instruments at both baseline
and 6-month follow-up. The 6-month symptom severity levels were compared between
the groups, controlling for baseline symptom status and potential confounders.
RESULTS: At 6-month follow-up, the upper/middle social class of origin group, as
compared to the lower social class of origin group, had lower symptom levels for
hallucinations (adjusted OR = 4.88, chi2 = 8.49, P = 0.004) and delusions
(adjusted OR = 2.46, chi2 = 4.16, P = 0.04). There were no notable group
differences for any of the negative or thought disorganization symptoms.
CONCLUSIONS: Social class of origin is associated with positive symptoms of
schizophrenia over the early illness course.
PMID- 10784368
TI - Access to physician treatment for a mental disorder: a regional analysis.
AB - BACKGROUND: This study examined (1) disparities in the proportion of persons who
accessed a physician for treatment of a diagnosed mental disorder across 17
health regions in Alberta, Canada, and (2) the extent to which regional
disparities in physician access could be explained by differences in regional
demographies, population needs, or physician supply. METHODS: The study
illustrates the use of ecological comparisons for regional health system
performance evaluations. Regional characteristics were aggregated from four
sources of data: the health insurance registry file (population denominators and
regional demographies), physician claims data (treatment access), census data
(social indicators of population need), and the medical directory of the College
of Physicians of Surgeons (physician supply). RESULTS: Regional variability in
needs-adjusted measures of access to physician-based treatment services were
comparatively small (varying by a factor of 1.6). Models containing adjustments
for demography, need, and physician supply explained 41% of regional variation in
access. Of the total variation explained, physician supply explained a smaller
proportion (39%) in comparison to social demography and needs (61%). Few large
regional imbalances were noted when needs-adjusted and supply-adjusted estimates
were compared. Only two areas appeared to be underserviced in comparison to their
local needs, reflecting approximately 6% of the provincial population.
CONCLUSIONS: While all three study factors proved important, findings support the
broad conclusion that social demography and social risk (a proxy for need) will
remain the key determinants predicting access to physician services for treatment
of mental disorders in publicly funded health systems.
PMID- 10784369
TI - Mental disorders and employee sickness absence: the NEMESIS study. Netherlands
Mental Health Survey and Incidence Study.
AB - BACKGROUND: This study aimed to determine to what extent different forms of
mental disorders are related to an increased likelihood of sickness absence and
whether this increase depends on the employee's sex. METHODS: Data of 3,695
employed persons aged 18-64 years from a national sample of the Dutch population
were derived from the first two waves of the Netherlands Mental Health Survey and
Incidence Study (NEMESIS). Mental disorders (DSM-III-R) in the past 12 months
were assessed at baseline (1996). Subsequent sickness absence was assessed at the
follow-up 1 year later. Somatic illnesses and age were included as controlled
confounders. RESULTS: Major depressive disorder, dysthymia, simple phobia and
drug abuse/dependence were predictive of sickness absence in men. In women, the
associations were weaker, and none of the 1-year DSM-III-R disorders was
significantly related to the likelihood of sickness absence. CONCLUSIONS: Mental
disorders are a more important risk factor for sickness absence for male
employees than for female employees. Knowledge of this sex difference can be
valuable for the development of interventions aiming at reducing sickness absence
rates due to mental illness.
PMID- 10784371
TI - Bulimic disorders and sociocentric values in north India.
AB - BACKGROUND: Previous studies have shown low rates of eating disorders in some
developing countries. We set out to investigate the prevalence of bulimia in an
all-female college population in north India and relate it to sociocentrism of
the culture. METHODS: A total of 504 students in an all-girls private college in
an industrial town in north India completed the Hindi translation of the Bulimia
Investigatory Test, Edinburgh (BITE). A random sample of 50 students,
irrespective of their scores, were interviewed using the DSM-III-R interview for
eating disorders; they were also asked about qualitative aspects of their
relationship with the family and their own views of their identity. RESULTS:
There was no effect of age, social class, religion or height on the distribution
of BITE scores. Three key factors emerged; these were related to the constructs
of compulsive activity, impulsivity/sociocentric avoidance and associated
attitudinal responses and depressive thinking with features of helplessness and
feelings of failure. Acculturation was not related to BITE scores. Virtually all
interviewees had sociocentric views of theirselves. CONCLUSIONS: Sociocentrism
and impulsivity account for a significant amount of the variance. The role of
sociocentrism in influencing patterns of eating deserves to be studied further.
PMID- 10784370
TI - Threshold Assessment Grid (TAG): the development of a valid and brief scale to
assess the severity of mental illness.
AB - BACKGROUND: Lack of consensus about the meaning of severe mental illness makes it
difficult to prioritise the severely mentally ill for specialist mental health
care. The goal of this study was to develop a valid and brief assessment of
severity of mental illness. METHOD: Six search workshops (n = 57) using consensus
techniques developed a draft assessment acceptable to users, carers,
practitioners and policy makers. A two-round Delphi consultation (n = 58) was
held to identify consensus on this instrument. RESULTS: Search workshops agreed
seven domains relevant to identifying the severely mentally ill: intentional and
unintentional self-harm, risk from and to others, and survival, psychological,
and social needs and disabilities. The Delphi consultation indicated at least
agreement with all aspects in both rounds. CONCLUSIONS: The Threshold Assessment
Grid (TAG) is a brief method of identifying the severely mentally ill, which has
adequate face, concurrent, construct and content validity.
PMID- 10784372
TI - Social class, income, education, area of residence and psychological distress:
does social class have an independent effect on psychological distress in
Antalya, Turkey?
AB - AIM: The aim of this study is to determine the separate effects of social class,
income, education and area of residence on psychological distress. The study also
assesses whether the association between prevalence of high score on the 12-item
General Health Questionnaire (GHQ 12) and social class is independent of other
variables. METHOD: Psychological distress was assessed by means of the GHQ 12.
The study covered 1,092 adults aged 15 years or more living in two different
quarters of Antalya. Social class status was defined by occupational position,
with income, education and area of residence treated as confounders. Chi-square
and logistic regression analyses were used to evaluate the data. RESULTS: Large
inequalities in psychological distress by all variables were observed.
Psychological distress was significantly associated with class status, after
adjusting for income, education, area of residence and other potential
confounders (age, sex and marital status). Class inequalities in psychological
distress were observed between blue-collar workers/unqualified employees and
bourgeoisie. CONCLUSIONS: These findings support the view that the recent
widening of inequalities among social classes in Turkey pose a substantial threat
to health.
PMID- 10784374
TI - Acute myocardial infarction and Helicobacter pylori seropositivity.
AB - Infectious agents including Helicobacter pylori, have been linked to coronary
heart diseases on epidemiological and pathogenetic grounds. Classical risk
factors fail to explain all the epidemiological variations of the disease. Our
aim was to investigate the association of acute myocardial infarction with
Helicobacter pylori infection in a case-control study by comparing a group of
male patients with a control group of blood donors matched for sex and age. We
investigated the classical cardiovascular risk factors in all patients. We
studied 44 consecutive male patients, aged 40-65 years, admitted for acute
myocardial infarction to the Coronary Care Unit at Novi Ligure Hospital in
northern Italy. Helicobacter pylori infection was assessed by measurement of
antibodies (IgG) against Helicobacter pylori in blood. Volunteer blood donors
attending Molinette Hospital Blood Bank in Turin, northern Italy served as
controls. Among the patients we investigated the presence of hypertension,
cholesterol and glucose levels in serum, fibrinogen in plasma, smoking habits,
and social class. Helicobacter pylori infection was present in 34 of 44 (77%)
patients and in 183 of 310 (59%) controls (P<0.05); the odds ratio was 2.36 (95%
confidence interval 1.08-5.31). Classical cardiovascular risk factors did not
differ among patients with and without Helicobacter pylori infection. In
conclusion, patients with acute myocardial infarction had a significantly higher
prevalence of Helicobacter pylori infection than the control population. The
classical risk factors for cardiovascular diseases were equally distributed among
patients irrespective of their Helicobacter pylori status.
PMID- 10784373
TI - Protein-bound polysaccharide (PSK) induces cytotoxic activity in the NKL human
natural killer cell line.
AB - We studied the effect of protein-bound polysaccharide PSK on the activation of
the human natural killer cell line NKL. We observed an increased natural killer
cytotoxic activity against different tumor cells (K562, Daudi, and U937) when a
standard 2- to 3-h 51chromium release assay was performed. The results parallel
those obtained after treatment of the NKL cell line with interleukin-2. The
highest cytotoxic activity was reached at a concentration of 100 microg/ml of
PSK. This natural killer activation was inhibited when the PSK dose was 1,000
microg/ml. None of the cell surface markers that were analyzed by fluorescence
activated cell sorting showed variations after PSK or interleukin-2 treatment of
NKL cells. These markers included CD2, CD11b, CD11c, CD18, CD16, CD54, CD56,
CD98, CD25, CD122, HLA class I, HLA class II, CD94, ILT2, p58.1, p70, and NKp46.
One of these markers (NKp46) is a major triggering receptor reported to be
involved in the natural cytotoxicity of fresh or cultured human natural killer
cells. In our study, another triggering receptor must be implicated in PSK
induced natural killer lysis. Our data suggest that PSK is an important
biological response modifier of natural killer cells in vitro and may prove to be
useful for the study of human natural killer cell biology.
PMID- 10784375
TI - The pre-procedural platelet state predicts clinical recurrence after coronary
angioplasty.
AB - Percutaneous transluminal coronary angioplasty is an established therapy for
coronary artery disease, but restenosis still occurs at a rate of 25%-40%. The
aim of this study was to investigate the acute effect of percutaneous
transluminal coronary angioplasty on platelet function and the relationship
between platelet function and clinical recurrence. Spontaneous platelet
aggregation was assessed before and after successful coronary angioplasty in 155
patients (120 men, 35 women). Patients were followed for a mean time of 20
months; follow-up angiography was performed only in patients with clinical
recurrence. In 122 of 155 patients (79%) a significant increase in spontaneous
platelet aggregation was observed immediately after coronary angioplasty.
Baseline spontaneous platelet aggregation in platelet-rich plasma was
significantly lower in patients with clinical recurrence than in those without
(P<0.05). Kaplan-Meier event-free survival estimate showed a significant
difference in clinical recurrence between patients with spontaneous platelet
aggregation in platelet-rich plasma below and above the first quintile (P<0.05)
with a relative risk of 2.5. In conclusion. these results indicate that
percutaneous transluminal coronary angioplasty enhances spontaneous platelet
aggregation and that the platelet state before coronary angioplasty affects the
risk of clinical recurrence after the procedure.
PMID- 10784376
TI - The influence of smoking on von Willebrand factor is already manifest in healthy
adolescent females: the Floren-teen (Florence Teenager) Study.
AB - The early onset of atherosclerosis and the involvement of physiological
biochemical, and environmental factors in its pathogenesis is well documented.
Few data are available on the role of risk factors related to hemostasis in the
pathogenesis of atherosclerosis in the young and, in particular, little
information is available on adolescent populations. In the Study of Preventive
Medicine and Education Program (Floren-teen Study), von Willebrand factor, a risk
factor for cardiovascular disorder, was studied, together with classical
cardiovascular risk factors, in apparently healthy students from two high schools
in Florence. Familial and personal history, physical examination, and
cardiovascular risk factors were evaluated in 144 students (aged 17-19 years).
Blood was withdrawn to assess von Willebrand factor (ELISA) and lipid parameters.
Levels of von Willebrand factor were significantly higher (P<0.044) in smokers
than in nonsmokers and were correlated with the number of cigarettes per day in
the whole group (P=0.01) and in females (P=0.006). In females a positive
correlation was observed between von Willebrand factor and high-density
lipoprotein cholesterol (P=0.0365). There was no significant correlation between
von Willebrand factor and blood pressure or between von Willebrand factor and
physical activity. In conclusion, this study shows an association between levels
of von Willebrand factor and smoking habits and is the first show that even a
brief period of smoking affects levels of von Willebrand factor in healthy
adolescent females independently of other risk factors. These results stress the
relevance of extending prevention programs to reduce smoking in high school
students.
PMID- 10784377
TI - Correlation of low-density lipoprotein modification by myeloperoxidase with
hypochlorous acid formation.
AB - Myeloperoxidase is an enzyme in phagocytes which catalyzes several redox
reactions. A major product is hypochlorous acid which appears to be important in
inflammatory processes such as atherosclerosis. The aim of this study was to
investigate whether the kinetics of low-density lipoprotein modification by the
myeloperoxidase/hydrogen peroxide/chloride system in vitro conform to the
established kinetics of hypochlorous acid formation and to compare the results
with known in vivo data. The absorbance at 234 nm was applied to study the
kinetics of the modification of low-density lipoprotein. Variation of the
concentration of low-density lipoprotein, hydrogen peroxide, and chloride,
respectively, had a biphasic effect on the maximal rate of low-density
lipoprotein modification. Increasing the substrates up to certain threshold
levels resulted in increased modification, however, further increases caused
inhibition of low-density lipoprotein modification. The inhibitory effect of
higher low-density lipoprotein concentrations might be relevant, since these
concentrations occur in the human aortic intima. Furthermore, a positive
correlation was found between the maximal rate of low-density lipoprotein
modification and the acidity of the medium. In summary, low-density lipoprotein
modification is affected by the myeloperoxidase/hydrogen peroxide/chloride system
in a similar manner to hypochlorous acid production. We conclude that
myeloperoxidase, which has been detected in atherosclerotic lesions, is able to
modify low-density lipoprotein into the form which is taken up by macrophages in
an uncontrolled manner.
PMID- 10784378
TI - Urinary hypoxanthine and xanthine levels in acute coronary syndromes.
AB - Ischemia leads to impaired ATP metabolism, with increased production of purine
degradation products, such as hypoxanthine and xanthine, which are useful markers
of tissue hypoxia. These extracellular markers of ischemia have been studied
extensively in many clinical conditions of oxidative stress, including perinatal
asphyxia, acute respiratory distress syndrome, cerebral ischemia, and
preeclampsia. The aim of this study was to explore the usefulness of urinary
hypoxanthine and xanthine as ischemia markers in acute coronary syndromes.
Urinary excretion of hypoxanthine and xanthine was assessed by high-performance
liquid chromatography in 30 patients with acute coronary syndromes and in 30 age-
and sex-matched controls. Serum and urine uric acid, creatinine, and urea
concentrations were also determined. Hypoxanthine excretion was significantly
elevated in patients compared with healthy controls (84.37+/-8.63 and 42.70+/
3.97 nmol/mg creatinine, mean+/-SEM, P<0.0001). Urinary xanthine levels were also
increased in patients with acute coronary syndromes (100.13+/-12.14 and 34.74+/
4.07 nmol/mg creatinine patients and controls, respectively; P<0.0001).
Hypoxanthine and xanthine excretion showed a strong positive correlation in both
groups. Significant negative correlations between urinary hypoxanthine and uric
acid and xanthine and uric acid were observed in the patients, but not in
controls. In conclusion, increased levels of ATP degradation products
hypoxanthine and xanthine are observed in various hypoxic clinical conditions.
This study suggests that these parameters may be useful markers of ischemia in
patients with acute coronary syndromes.
PMID- 10784379
TI - Selective upregulation of MHC class I expression in metastatic colonies derived
from tumor clones of a murine fibrosarcoma.
AB - Eighteen metastatic nodes derived from the wild-type (GR9) and from 4 different
clones (G2, D8, B10, and B9) obtained from a fibrosarcoma were analyzed for H-2
class I and II expression, as well as for adhesion molecules (CD44, CDIIb, CD18,
CD49, and CD54). When metastatic nodes were cultured, typed for H-2 antigens, and
compared with the H-2 expression of the inducing tumor cell, H-2 Kd and Dd class
I expression was greater in most nodes analyzed. In contrast, the Ld molecule
remained negative, or showed a minor increase. Class II expression was negative
in the wild-type and the tumor clones, and remained so in the metastatic
colonies. Analysis of the adhesion molecules revealed no differences between the
inducing tumor cells and the metastatic nodes. The only molecule expressed was
CD44, which was present in all cells studied and was also inducible by interferon
gamma. The increase in H-2K and H-2D expression was associated with resistance to
natural killer cytotoxicity, as observed in the G2 tumor clone and some
autologous metastases, such as B9MP2, G2MK2, and G2MLI. In three independent
clones of this tumor system (D8, BIOMP6, and B9MP6) we found that tumor cells
treated with interferon-gamma had the same altered phenotype, i.e., a selective
lack of response of the Ld molecule to induction. These findings add a cautionary
note to the well-established idea that tumor cells may lose all class I antigens
during tumor progression, and suggest that sometimes this may not be the case.
The selective downregulation of Ld and upregulation of Kd and Dd class I
expression may give some tumor cells means of escaping both cytotoxic lymphocyte
and natural killer immune surveillance.
PMID- 10784380
TI - Analysis of three genetic polymorphisms as risk factors for thrombosis.
PMID- 10784381
TI - Oxysterol-induced cell death in U937 and HepG2 cells at reduced and normal serum
concentrations.
AB - BACKGROUND AND AIMS: Cholesterol oxidation products (oxysterols) are commonly
found in foods of animal origin and are also produced endogenously in the body.
Oxysterols are cytotoxic to certain cell lines and in some cases have been shown
to induce apoptosis. The aim of this study was to investigate the effects of
7beta-hydroxy-cholesterol (7beta-OHC) and 25-hydroxycholesterol (25-OHC) on
cytotoxicity and induction of apoptosis in U937 and HepG2 cells, treated in media
containing either 2.5% foetal calf serum (FCS) or 10% FCS to examine the effect
of increasing the cholesterol level. METHODS: The cells were incubated for 24 and
48 h with 30 microM oxysterol. Viability was assessed by fluorescein
diacetate/ethidium bromide staining and cell proliferation was determined by
haemocytometer counting. Apoptosis was monitored by detection of DNA fragments
(laddering) in 1.5% agarose gels. Cells with condensed or fragmented nuclei were
identified by Hoechst 33342 staining. The percentage of cells with sub-G1 levels
of DNA was measured by flow cytometry. RESULTS: Treatment of U937 cells with
7beta-OHC, in contrast to 25-OHC, resulted in a decrease in cell viability and
proliferation at 24 and 48 h (P <.01). 25-OHC and 7beta-OHC were both equally
cytotoxic to the HepG2 cell line. 7beta-OHC induced DNA laddering and an increase
in the percentage of condensed or fragmented nuclei at both time points and at
both serum concentrations in the U937 cell line. 25-OHC induced faint laddering
in the U937 cells after 48 h in reduced serum media and resulted in a small
increase in percentage condensed or fragmented nuclei which was independent of
time of oxysterol exposure and serum concentration. The percentage of condensed
or fragmented nuclei was low in the HepG2 cell line and no laddering was observed
under any of the conditions studied. Flow cytometric analysis showed that only
7beta-OHC treated U937 cells had an increased level of hypodiploid cells.
CONCLUSION: Both oxysterols appear to be equally cytotoxic to the HepG2 cell
line. In U937 cells, 25-OHC is much less cytotoxic than 7beta-OHC. In addition,
we have shown that 7beta-OHC induces apoptosis in U937 cells. 10% FCS displays a
protective effect on cytotoxicity (as well as on 7beta-OHC induced apoptosis in
U937 cells), although the data did not reach statistical significance.
PMID- 10784382
TI - Chronic arginine aspartate supplementation in runners reduces total plasma amino
acid level at rest and during a marathon run.
AB - BACKGROUND: Athletes consume arginine and/or aspartate as potential nutritional
ergogenics. Their metabolic effects are controversial and there is some evidence
that ingestion of large doses of single amino acids can adversely affect the
nitrogen balance or induce an amino acid imbalance. Nevertheless, the general
metabolic influence of an arginine aspartate supplementation during a prolonged
exercise bout has not yet been investigated. AIM OF THE STUDY: The aim of this
study was, therefore, to investigate the general metabolic impact of a chronic
supplementation with arginine aspartate in endurance-trained athletes at rest and
during a marathon run. METHODS: Fourteen endurance-trained runners participated
in this field study which was carried out according to a double-blind crossover
design. 15 g of arginine aspartate or a carbohydrate-based placebo were
supplemented daily for 14 days before a marathon run. Blood samples for analysis
of metabolites and hormones were collected shortly before the run, after 31 km,
at the end of the run, and after a recovery period of two hours. Additionally,
the respiratory exchange ratio was determined during the run. RESULTS: The plasma
level of carbohydrate (glucose, lactate, pyruvate) and fat metabolites (fatty
acids, glycerol, beta-hydroxybutyrate), cortisol, insulin, ammonia, lactate
dehydrogenase, and creatine kinase as well as the respiratory exchange ratio were
unaffected by the supplementation. In contrast, the plasma level of somatotropic
hormone, glucagon, urea, and arginine were significantly increased, and the level
of most of the remaining plasma amino acids as well as their sum was
significantly reduced. CONCLUSIONS: There was no obvious metabolic benefit
derived from the chronic supplementation with arginine aspartate. And since
furthermore the consequences of a reduction of the total plasma amino acid level
are not known, the practice of using single amino acid supplements as potential
ergogenics should be critically reevaluated.
PMID- 10784383
TI - Conjugated linoleic acid effects on circulating hormones, metabolites and
lipoproteins, and its proportion in fasting serum and erythrocyte membranes of
swine.
AB - BACKGROUND: Conjugated linoleic acids (CLA)# refer to a group of linoleic acid
(18:2)-derived isomers with conjugated double bonds mostly at carbon atoms 9 and
11 or 10 and 12, and with all possible cis and trans combinations. CLA is a newly
recognized nutrient that functions to regulate energy retention and metabolism
and that causes a serum lipoprotein profile considered to be less atherogenic.
However, rodent models that have been frequently used for these studies are only
of limited use because of distinct differences in physiology, compared with man.
Additionally, possible differences in food intake between the experimental groups
remained often unconsidered in those studies. Thus, it can not be excluded that
the beneficial effects of CLA reported in a series of studies may be due, at
least partially, to differences in nutrient and energy ingested. AIMS OF THE
STUDY: This prompted us to undertake an investigation on the action of CLA by
using a pig model and a feeding regimen with controlled amounts of food and
antioxidants. The parameters used to assess CLA-specific action were selected
hormones and metabolites involved in energy metabolism, individual lipoproteins
and the appearance of CLA in fasting serum and erythrocyte membranes. Blood as an
easily available biological sample was used for investigation. METHODS: For that
purpose 16 adult female pigs were divided into two groups of 8 each, and were
isoenergetically fed diets containing 0 (control diet) or 1% level of CLA (by
weight) for 6 weeks. Plasma concentrations of total and free thyroxine (T4),
total and free triiodothyronine (T3), and insulin were measured by
radioimmunoassays. Plasma non-esterified fatty acids (NEFA), beta
hydroxybutyrate, circulating blood ATP and other clinical chemical variables were
determined using enzymatic assays. The concentration of alpha-tocopherol was
determined by high performance liquid chromatography. The lipoproteins VLDL
(density <1.019 kg/L), LDL (density 1.019 - 1.063 kg/L), and HDL (density >1.063
kg/L) were isolated by step-wise ultracentrifugation. Fatty acids of the dietary
oils, serum and blood cell membranes were separated and quantified by gas
chromatography. RESULTS: At week 6, body weights of the pigs fed the CLA
supplemented diet were not different from that of the controls. CLA-treated pigs
exhibited a 37% higher concentration of fasting serum insulin than their controls
receiving no CLA (P = 0.11). Circulating free and total T4 and T3 as well as
serum levels of beta-hydroxybutyrate, alpha-tocopherol, protein, glucose, urea,
creatinine and circulating blood ATP remained unaffected by CLA supplementation.
Serum concentrations of non-esterified fatty acids were reduced by 38% in CLA
treated pigs relative to the controls, although this difference was not
significant. CLA-treated pigs tended to have lower leukocyte counts in blood than
their controls (P <0.1). Erythrocyte and platelet counts, the hematocrit and
hemoglobin concentration were similar between the groups. Serum of CLA-treated
pigs showed a trend toward increased levels of triacylglycerols, cholesterol and
phosphatidylcholine in the very low density and low density lipoproteins (LDL),
without distinct changes in the high density lipoprotein fraction (HDL). The LDL
cholesterol to HDL cholesterol ratio was significantly increased by CLA. When
pigs were fed CLA at a dietary level of 1%, limited proportions of CLA appeared
in fasting serum (1.6%) and erythrocyte membranes (1.1%). CONCLUSIONS: Under the
present experimental conditions there appeared to be parallels between the
effects of CLA and the reported effects of trans fatty acids in the mode of
action on lipoproteins and insulin. The failure to demonstrate significant
beneficial effects of CLA on the lipoprotein profile which have been observed in
other studies requires further research.
PMID- 10784384
TI - Dietary fiber reduces the antioxidative effect of a carotenoid and alpha
tocopherol mixture on LDL oxidation ex vivo in humans.
AB - BACKGROUND: Antioxidant concentrations in low density lipoproteins (LDL) are an
important determinant for their susceptibility to oxidation and can be modulated
by dietary intake. AIM OF THE STUDY: In the present study, the influence of
dietary fiber on the antioxidant enrichment and the oxidation resistance of LDL
after antioxidant supplementation is investigated. METHOD: An antioxidant
supplement consisting of beta-carotene, lycopene, lutein, canthaxanthin and alpha
tocopherol was given to six young women together with a standard meal. Using a
cross-over study design, each subject received the standard meal without
additional dietary fiber and enriched with pectin, guar, or cellulose in a random
order. To determine the resistance of LDL against copper ion-induced oxidation,
the formation of conjugated dienes was measured. RESULTS: Eight, 10, and 24 hours
after antioxidant supplementation the isolated LDL revealed significantly (p <
0.05) increased antioxidant concentrations; addition of pectin, guar, or
cellulose to the meal depressed this increase. Concomitantly, the observed
increase in the resistance of LDL against oxidation (measured as lag phase) was
lower with dietary fiber supplementation than that found without. On average,
pectin, guar, and cellulose reduced the increase of the lag phase (measured
without addition of dietary fiber) by 38%, 22%, and 18%, respectively.
CONCLUSIONS: These results indicate that dietary fiber supplementation decreases
the antioxidative effect of a supplement consisting of carotenoids and alpha
tocopherol in LDL, an effect that is likely to be mediated by a reduced
bioavailability of these antioxidants in the gut.
PMID- 10784386
TI - Extracorporeal photochemotherapy in the treatment of severe graft-versus-host
disease.
AB - Advances in posttransplant immunosuppression have to the present not been able to
prevent the development of graft-versus-host disease (GVHD) in patients given
related or unrelated stem cell grafts for cure of hematologic diseases. Patients
with GVHD not responding to first line therapy with corticosteroids remain at
high risk of death due to severe infections or organ failure. Extracorporeal
exposure of peripheral blood mononuclear cells to the photosensitizing agent 8
methoxypsoralen and ultraviolet A radiation has been shown to be effective in
treatment of selected T-cell mediated diseases, including cutaneous T-cell
lymphoma and rejection after organ transplantation. Extracorporeal
photochemotherapy (ECP) is also a safe and efficacious adjunct therapy for both
acute and chronic extensive GVHD with skin and visceral involvement and
resistance to conventional immunosuppressive therapy. A multicenter randomized
study should help define the impact of ECP in the treatment of GVHD and overall
survival of these patients.
PMID- 10784385
TI - Impact of diets with corn oil or olive/sunflower oils on DNA damage in healthy
young men.
AB - BACKGROUND: Plant fats and oils are major sources of mono- and polyunsaturated
fatty acids as well as vitamin E, the major fat-soluble antioxidants in human
nutrition. Dietary antioxidants are expected to reduce cancer risk by minimizing
DNA damage. AIM OF THE STUDY: To compare the effects of gamma-tocopherol rich
corn oil and the mixture of the alpha-tocopherol rich olive/sunflower oil on
plasma concentration of tocopherols and on the frequency of sister chromatid
exchange (SCE), an indicator of DNA damage. METHODS: This study had a double
blind, cross-over design and was conducted in 20 normal healthy non-smoking males
aged 19-31 years. Design included a 2-week adjustment period and two 2-week test
periods in which diets containing 30% energy as fat including either 80 g of corn
oil (CO) (20 mg alpha-tocopherol, 100 mg gamma-tocopherol) or 80 g of olive/
sunflower oil (OSO) (24 mg alpha-tocopherol, 2.4 mg gamma-tocopherol), as the
main fat-source, were given. Blood samples for analysis of SCE rate and content
of tocopherols were collected at the beginning (T0), after adjustment (T1) and
after the test period (T2) in intervals of 2 weeks. RESULTS: After two weeks of
the corn oil diet, the plasma concentration of gamma-tocopherol increased but
alpha-tocopherol decreased significantly compared to the olive/sunflower oil
diet. The concentration of alpha-tocopherol increased (CO: 22.99 +/- 1.11 vs.
OSO: 24.40 +/- 1.49 micromol/l) and that of gamma-tocopherol decreased (CO: 4.19
+/- 0.29 vs. OSO: 2.99 +/- 0.25 micromol/l) after the olive/sunflower oil diet.
Intake of the corn oil diet was associated with reduced SCE rate and intensity,
whereas there was no change in SCE after the olive/sunflower oil diet (CO: 7.66
+/- 0.25 vs. OSO: 8.06 +/- 0.47 mean SCE/cell) CONCLUSIONS: The combination of
gamma-tocopherol with alpha-tocopherol in corn oil diet despite the lower alpha
tocopherol equivalents/diene acid equivalents ratio achieved better protection
against DNA damage than alpha-tocopherol alone in the olive/sunflower oil diet.
PMID- 10784387
TI - The t(9;14)(p13;q32) translocation in B-cell non-Hodgkin's lymphoma.
AB - t(9;14)(p13;q32) is a rare but recurring translocation found in a subset of B
cell non-Hodgkin's lymphoma (B-NHL). These lymphomas share clinical features with
chronic lymphocytic leukemia and are further characterized by plasmacytoid
differentiation of lymphoma cells. Molecular cloning of t(9;14)(p13;q32) revealed
juxtaposition of the PAX5 to the immunoglobulin heavy chain gene (IGH), although
breakpoints on both genes were variable. The PAX5 gene encodes the BSAP (B-cell
specific activator protein) transcription factor, which is expressed throughout
the process of B-cell development except in terminally differentiated plasma
cells. t(9;14)(p13;q32) consistently leaves the PAX5 coding region intact, most
likely resulting in deregulated expression of the gene product due to the
proximity of IGH. The majority cases of B-cell tumors expressed considerable
levels of PAX5/BSAP irrespective of whether they exhibited t(9;14)(p13;q32),
suggesting that quantitative differences in expression level alone may not
account for the development of this particular subtype of B-NHL.
PMID- 10784388
TI - Primary effusion lymphoma cell lines harbouring human herpesvirus type-8.
AB - Primary effusion lymphoma (PEL) is a novel lymphoma entity consistently infected
by HHV-8 that occurs predominantly in immunodeficient patients and is
characterized by liquid growth in the serous body cavities. In order to
facilitate the understanding of PEL pathogenesis and histogenesis, we have
established three PEL cell lines termed CRO-AP/2, CRO-AP/3 and CRO-AP/5. All cell
lines have been derived from HIV positive homosexual men affected by PEL with (in
the case of CRO-AP/2 and CRO-AP/5) or without (in the case of CRO-AP/3) a
previous history of Kaposi's sarcoma. The cell lines are representative of both
virologic variants of PEL, i.e. HHV-8+ EBV+ PEL (CRO-AP/2 and CRO-AP/5) and HHV
8+ EBV- PEL (CRO-AP/3). Morphologic and phenotypic features of CRO-AP/2, CRO-AP/3
and CRO-AP/5 are typical of PEL, and include morphology bridging immunoblastic
and anaplastic features as well as an indeterminate (non B- non T-cell)
phenotype. The B-cell nature of the cell lines is documented by the presence of
rearranged immunoglobulin genes. The detailed analysis of the molecular and
phenotypic features of CRO-AP/2, CRO-AP/3 and CRO-AP/5 has allowed the
identification of recurrent chromosomal abnormalities of PEL and has contributed
to the definition of PEL as a lymphoma of post-germinal center, pre-terminally
differentiated B-cells.
PMID- 10784389
TI - Leptin receptor and leukemia.
AB - The receptor for leptin, the gene product of the obese gene, is expressed in
hematopoietic stem cells. Leptin stimulates normal myeloid and erythroid
development, and is secreted from bone marrow adipocytes, which occupy most of
the marrow cavity in humans. Leptin might thus play an important role in the
control of the expansion and differentiation of primitive hematopoietic cells
through paracrine interaction in the bone marrow microenvironment. Leukemic cells
of some patients with acute myeloblastic leukemia, acute lymphoblastic leukemia,
and chronic myeloid leukemia (CML) also express the leptin receptor. In cases of
CML, higher expression of leptin receptor is observed during blast crisis than in
chronic phase. Leptin alone and in combination with other cytokines has
stimulative effects on proliferation of leukemia cells as well as anti-apoptotic
effects. These findings suggest the possibility that leptin plays roles in the
pathophysiology of leukemia.
PMID- 10784390
TI - Clinical implications of aberrant TSG101 transcripts in acute myeloblastic
leukemia.
AB - Tsg101 is a mouse tumor suppressor gene whose homozygous deletion produces
transformation of NIH3T3 cells and leads to metastases in nude mice. The human
homologue of the gene, TSG101, is localized in chromosome 11p15.1-p15.2. Reduced
TSG101 expression may cause the defect of the cell cycle checkpoint that leads to
genetic instability and consequently to the progression of neoplasia. Aberrant
TSG101 transcript have been identified in many types of cancers, and the
relaxation of RNA splicing fidelity may be an onco-developmental marker in
cancers and could play a general role in tumorigenesis. In our previous study,
smaller TSG101 transcripts were found in AML specimens, hematopoietic cell lines
and normal controls. The aberrant transcripts occurred more frequently in the AML
cases and cell lines. The patients with aberrant TSG101 transcripts had higher
initial white cell count, lower LDH level, and lower complete remission rate
after induction chemotherapy. However, further multivariate analysis of clinical
data revealed that there was no relationship to the TSG101 aberrant transcripts.
The clinical significance of TSG101 aberrant transcript in AML needs further
evaluation.
PMID- 10784391
TI - Clinical significance of deletions of chromosome arm 6q in childhood acute
lymphoblastic leukemia: a report from the Children's Cancer Group.
AB - We have compared outcome for 167 (9.0%) children with a del(6q) and 1713 (91%)
children without a del(6q) treated on Children's Cancer Group (CCG) risk-adjusted
treatment protocols for acute lymphoblastic leukemia (ALL). Thirty-three patients
had a del(6q) as the sole aberration; 22 patients had a del(6q) only as a
secondary abnormality. Thirty-six cases had a del(6q) and high hyperdiploidy (>50
chromosomes). Six patients with a del(6q) also had +16 and 8 patients had loss of
a sex chromosome. Frequent recurring breakpoints were q13, q15, q21, q23, and
q25. Patients with a del(6q) were more likely to have T-lineage ALL (p < 0.001),
a mediastinal mass (p = 0.01), and higher WBC counts (p = 0.04), although only
half of these patients were classified as poor risk. Event-free survival at 6
years was similar for patients with or without a del(6q), with estimates of 77%
(SD = 5%) and 74% (SD = 2%), respectively (p = 0.44). This finding was also
observed within NCI poor and standard risk groups. Thus, cytogenetically
detectable del(6q) is not associated with adverse risk in pediatric ALL.
PMID- 10784392
TI - Cyclophosphamide, ara-C and topotecan (CAT) for patients with refractory or
relapsed acute leukemia.
AB - Topotecan is a topoisomerase I inhibitor with significant activity in patients
with myelodysplastic syndrome and chronic myelomonocytic leukemia. Pre-clinical
data suggest a synergistic activity with DNA damaging agents such as
cyclophosphamide, where topotecan might prevent the repair of cyclophosphamide
induced DNA damage. We thus designed a combination including cyclophosphamide 500
mg/m2 every 12 hours given on days 1 to 3; topotecan 1.25 mg/m2/day by continuous
infusion on days 2 to 6, and cytosine arabinoside (ara-C) 2 g/m2 over 4 hours
daily for 5 days on days 2 to 6 (CAT). Sixty six (63 evaluable) patients were
treated. Fifty two patients had refractory (n=12) or relapsed (n=40) acute
myelogenous leukemia (AML), and eleven had acute lymphocytic leukemia (ALL)
(refractory n=3, relapsed n=8); their median age was 57 years (range, 18 to 79
years). Eleven patients (17%) achieved a complete remission (CR), and two
patients (3%) had a hematologic improvement (HI; met all criteria for CR except
for platelets < 100x10(9)/L), for an overall response rate of 20%. Responses
occurred in 12 of 52 AML patients (23%), including 10 CR (19%) and 2 HI (4%), and
in 1 of 11 patients with ALL (9%). Myelosuppression was universal; there were 23
episodes of pneumonia or sepsis and 18 episodes of fever of unknown origin
complicating 74 courses of CAT. Non-hematologic toxicity was mostly
gastrointestinal, including nausea, vomiting, diarrhea and mucositis, but was
severe in only 8%. In summary, the CAT regimen is well tolerated and has
significant anti-leukemia activity which warrants further investigation.
PMID- 10784393
TI - A four-parameter index of marrow dysplasia has predictive value for survival in
myelodysplastic syndromes.
AB - Marrow dysplasia is a major characteristic of patients with myelodysplastic
syndrome (MDS), along with marrow blastosis, cytopenia and cytogenetic anomalies.
However, the impact of the degree of marrow dysplasia on survival has not been
fully assessed. In this retrospective analysis of 111 patients selected according
to the IPSS criteria of MDS diagnosis, the presence or absence of 21 dysplasia
characteristics recognizable in bone marrow smears stained by the May-Grunwald
Giemsa method was correlated with patient survival. Using Cox proportional
hazards regression analysis, megaloblastosis (MEGALO), neutrophil agranularity
(AGRAN) and hypogranularity (HYPOGRAN) were highly significant predictors (p <
0.005), and Pelger-Huet anomaly (PELGHUET) a significant predictor (p = 0.05), of
patient survival. The regression analysis yielded a dysplasia-based risk index
(DI) where DI = 1.26 MEGALO + 0.82 AGRAN - 1.08 HYPOGRAN + 0.45 PELGHUET. The two
subgroups of 60 and 47 patients with DI < or = 0 and > 0 showed highly
significant differences in median survivals (2.6 vs 1.1 yrs; p <0.0001).
Multivariate analysis further showed that DI offered additional predictive power
that was independent of that provided by the IPSS (p=0.002 and 0.001
respectively). Analysis of survival curves stratified for IPSS and DI showed that
the additional predictive power offered by inclusion of the DI essentially
concerned the IPSS low/INT-1 risk categories. Further stratification for age did
not improve survival prediction. The data indicate that a set of 4 dysplasia
parameters can offer some prediction for survival of MDS patients in addition to
that provided by the IPSS. Further multicenter studies should aim at including
some form of evaluation of the degree of dysplasia in prognostic systems.
PMID- 10784394
TI - High dose chemotherapy without hematopoietic cell support for the treatment of
refractory lymphoma.
AB - Conventional dose combination chemotherapy for patients with relapsed or
refractory lymphoma is rarely curative. High dose chemotherapy followed by
hematopoietic progenitor cell transplant (HPCT) has a clearly defined role in
patients who have first relapsed after standard CHOP chemotherapy for lymphoma.
However, the role of HPCT is less well defined for patients with chemo-resistant,
or chemo-refractory disease. Sixteen patients (15 Non-Hodgkin's, 1 Hodgkin's
Disease) were entered into a phase II study to determine if a dose intensive
induction regimen in heavily pre-treated refractory lymphoma patients could
permit further consolidation with HPCT. The primary endpoints were survival,
response, toxicity, and resource utilization. The regimen consisted of continuous
infusion etoposide 1 or 2 gm/m2/72 hours, idarubicin 12 mg/m2/d for 3 days
followed by cytarabine 2 gm/m2/72 hours on days 8, 9, and 10 (VIC). Fifteen
patients were evaluable for objective response. The overall response rate was 53%
with 7 patients achieving a partial response and 1 patient achieving a complete
response. Of the 8 responders, 6 patients subsequently received high dose
chemotherapy followed by HPCT (4 autologous, 2 allogeneic). The median survival
was 176 days for the non-responders contrasted with 722 days for the responders.
The average duration of hospitalization was 38 days. Toxicity was mainfest
primarily as mucositis with a median grade of 3 among the first 13 patients, and
a median grade of 2 in three subsequent patients who received an etoposide dose
of 1 gm/m2/72 hours. All patients had an episode of neutropenic fever and 5
patients developed clinically significant pneumonitis during therapy. The VIC
regimen is active in the treatment of chemo-refractory lymphoma with clinically
significant differences in survival for patients who respond to therapy. Further
modifications to the regimen could include the addition of a topoisomerase I
inhibitor for synergy with etoposide, and using VIC as part of a tandem
transplant regimen where response to VIC would allow further therapy with a
myeloablative induction followed by HPCT.
PMID- 10784395
TI - Simultaneous detection of BCL-2 protein, trisomy 12, retinoblastoma and P53
monoallelic gene deletions in B-cell chronic lymphocytic leukemia by fluorescence
in situ hybridization (FISH): relation to disease status.
AB - Various genetic abnormalities are often found in B-CLL, but their relative
importance in the pathogenesis and evolution of the disease has not been
adequately clarified. We studied the expression of bcl-2 protein and the possible
simultaneous occurrence of bcl-2 overexpression, trisomy 12 and the Rb1 and p53
gene deletions in 38 patients with B-CLL by combining immunophenotyping and dual
color interphase FISH. We also looked for correlation between the genetic
abnormalities and clinical parameters such as stage, disease duration from
diagnosis to the time of study and overall survival. High expression of the bcl-2
protein was found in 76.3% of the patients (29/38). Trisomy 12 was found in 37%
of cases (14/38) and Rb1 monoallelic gene deletion in 42% (16/38). The percentage
of cells with hemizygous Rb1 deletion ranged from 13 to 18%. Monoallelic deletion
of p53 was found in 29% of cases (11/38). The number of cells with only one
signal ranged from 28 to 98%. Patients in stage A had on average, less than one
abnormality, while patients in stage C had 2.6 abnormalities. Patients appeared
to accumulate genetic abnormalities with time. Bcl-2 overexpression was found
early in the course of the disease. Trisomy 12 appeared later, at about the same
time as Rb1 deletion, but was not associated with adverse prognosis. Monoallelic
deletion of p53 gene appeared rather late in the course of the disease and was
associated with advanced stage. Despite the fact that more deaths occurred in the
group of patients with three or four abnormalities and the presence of p53 gene
deletion, differences in survival were not statistically significant, probably
due to the limited number of patients in each group. A larger group of patients
studied in a prospective manner will better clarify these issues in the future.
PMID- 10784396
TI - Clinical significance of the t(14;18) and BCL2 overexpression in follicular large
cell lymphoma.
AB - Follicular large cell lymphoma (FLCL) is an aggressive disease that responds to
anthracycline-containing chemotherapy much like diffuse large B-cell lymphoma
(DLBCL). Since the t(14;18) and/or bcl2 protein expression are less common in
FLCL than in its low-grade counterparts, we sought to determine whether these
features were predictive of survival as in DLBCL. We studied 50 patients with
FLCL who were treated with curative intent. The t(14;18) was found by cytogenetic
analysis in 56% of the patients and bcl2 protein was expressed by the tumor cells
in 73%, but neither was predictive of survival. However, abnormalities of
chromosome 17p and the presence of trisomy 21 were adverse predictors of
survival, as were a number of clinical features. We conclude that neither the
absence of the t(14;18) nor the lack of bcl2 expression explain the good response
of a subset of patients with FLCL to curative therapy.
PMID- 10784397
TI - A prospective study of the LMB regimen for diffuse large cell non Hodgkin's
lymphoma in adults.
AB - Although the CHOP regimen remains a standard first line chemotherapy for diffuse
large cell lymphoma (DLCL) in adults, a majority of these patients will still
experience disease progression after the completion of this treatment. The LMB
protocol is an intensive chemotherapy regimen which yields high survival rates in
Burkitt's lymphoma (BL) and diffuse large cell lymphoma (DLCL) in children, as
well as in primary cerebral DLCL (PCL) of adults. Here, we report the long term
results of this regimen in a prospective series of 22 adult patients with DLCL
excluding PCL. Fifteen male and 7 female patients with a median age of 30 years
(range: 20-55) were treated prospectively between 1988 and 1993. 16 (72%)
patients had an age adjusted International Pronostic Index (IPI) > or = 1. The
median duration of the treatment was 15 weeks (range 13-19). Nineteen of the 22
patients (87%) experienced an objective response (14 complete, and 5 partial
responses) at the end of the protocol. The predominant toxicity was
myelosuppression: 89% of the COPADEM courses were followed by grade IV
neutropenia and 5% with grade IV infection. One patient died (4%) of treatment
related toxicity. With a median follow-up of 94 months and a minimum follow-up of
65 months, 8-year overall and progression-free survival are 73% and 67%
respectively. The 8 year overall survival were 100%, 78% and 42% in patients with
an IPI 0, 1, and 2-3 respectively. This short intensive regimen yields promising
long term survival rates in this monocentric prospective study and may deserve to
be tested in a larger multicentric prospective study comparing it to the CHOP
regimen.
PMID- 10784398
TI - Serum erythropoietin and thrombopoietin levels in patients with essential
thrombocythaemia.
AB - In 40 patients with essential thrombocythaemia (ET) serum erythropoietin (EPO)
and thrombopoietin (TPO) concentrations were determined and compared with the EPO
and TPO values of a healthy control group. The mean EPO serum concentration for
24 control patients was 9.4 mU/ml +/- 3.7 (range 2-17.9), for 32 untreated ET
patients at diagnosis 6.6 mU/ml +/- 7.6 (range 0.5-44.3) and for 8 ET patients
treated with cytoreduction 14.1 mU/ml +/- 8.0 (range 4.5-26.1). Serum EPO levels
in untreated ET patients at diagnosis were significantly lower compared with
serum EPO levels in healthy control patients (p=0.002). Serum EPO levels in
treated ET patients were not different from serum EPO levels in healthy controls
(p=0.13) but were significantly higher compared with untreated ET patients
(p=0.003). Serum TPO levels were determined in 18 of 40 ET patients, the mean TPO
serum concentration was 211 pg/ml +/- 109 (range 62,5-345). The mean TPO serum
concentration for 10 untreated ET patients at diagnosis was 162 pg/ml +/- 87
(range 62,5-302) and for 8 ET patients who had received cytoreductive treatment
272 pg/ml +/- 106 (range 96-345), respectively (p=0.04). Both serum TPO levels
for treated and untreated ET patients were significantly higher (p<0.001)
compared with serum TPO levels for healthy controls. The results of our study
suggest a difference in the regulation of serum EPO and TPO in patients with ET.
While the mean serum EPO level is decreased in untreated ET patients, the
corresponding mean serum TPO level is increased. Treatment with cytoreduction,
results in normalisation of the mean serum EPO level, whereas the mean TPO serum
level remains elevated.
PMID- 10784399
TI - Acute myeloblastic leukemia secondary to myelodysplasia (MDS-AML): a comparison
of remission induction with three drugs versus standard two-drugs induction.
AB - To evaluate the addition of a third drug to standard induction chemotherapy in
patients with MDS-AML, 23 patients (males/females 13/10, median age 54.3 years,
range 24-74 years, median MDS duration 9.8 months, range 2-39 months) who
received a standard 2-drugs induction were compared with 23 patients
(males/females 11/12, median age 45.6 months, range 21-60 years, median MDS
duration 8.3 months, range 2-29 months) who received an intensified 3-drugs
induction with etoposide. CR rate, median CR duration and median OS were similar
in both groups (48% vs 56%, 4.8 vs 5.9 months, 6.5 vs 7.0 months respectively).
Among responding patients, all but one, who underwent allogeneic bone marrow
transplantation, relapsed. In conclusion, addition of a third drug (etoposide)
does not seem to significantly improve the poor prognosis of MDS-AML patients.
PMID- 10784400
TI - CD40 ligand-induced apoptosis is Fas-independent in human multiple myeloma cells.
AB - We and others previously demonstrated that human multiple myeloma (MM) cells
express CD40 and have an active CD40-growth regulatory pathway. This study
characterizes the growth outcome of soluble (gp39) or membrane-bound recombinant
human CD40-ligand (rCD40L) and its relationship with Fas-dependent apoptosis.
Contrary to the moderate growth-stimulatory effect of the CD40-MAb G28.5, gp39
inhibited 3H-thymidine uptake of the plasma dyscrasia lines ARH-77, U266, and HS
Sultan in a dose-dependent fashion by up to 82%. By comparison, RPMI 8226 cells
were resistant to CD40L-growth modulation, which may be attributable to a single
base substitution (TCA-->TTA, serine-->leucine) at the 3rd cysteine-rich
extramembrane region of CD40. Gp39 similarly reduced myeloma clonogenic colony
(MCC) formation in patient primary bone marrow cultures by 50% (40-76%; n=6).
Studies using transfectant L cells that constitutively expressed CD40L showed
that membrane-bound CD40L inhibited the growth of ARH-77, U266, and HS-Sultan
cells (66%, 63%, and 32%, respectively), whereas untransfected L cells did not.
Growth inhibition by gp39 or CD40L+ L cells was neutralized by coincubation with
the CD40L antibodies 5c8 or LL48. CD40L-treatment increased apoptotic activity of
MM cells, as defined by oligonucleosomal DNA fragmentation and an increased
binding to annexin V (16-28%). All three untreated CD40-responsive MM lines
expressed the Fas/Apo-1/CD95 antigen (65-92% CD95+). However, only ARH-77 cells
responded to the growth inhibitory effect of the CD95-agonistic antibody CH-11.
CD95 expression was not affected significantly by gp39 treatment, and growth
inhibition by CH-11 was additive to gp39 (from 42% to 64% decrease in 3H-thmidine
uptake). Conversely, the CD95 antagonist antibody ZB4 reversed the Fas-dependent
growth inhibitory process but did not significantly alter gp39-mediated growth
outcome. Gp39 treatment lowered the expression of TNFR-associated factors TRAF4
and TRAF6 by 38% and 32%, respectively, whereas detectable levels of TRAF1,2,3,
and 5 levels remained unchanged. Our observations indicate that the CD40L-binding
inhibits human MM cell growth and increases its apoptotic activity. This growth
inhibitory effect corresponds to lower levels of cytoplasmic TRAF signaling
elements, and appears independent of the Fas-signaling pathway. CD40 receptor
mutation may lead to unresponsiveness to CD40 growth modulation in multiple
myeloma cells.
PMID- 10784401
TI - Induction of apoptosis by 2-chloro-2'deoxyadenosine (2-CdA) alone and in
combination with other cytotoxic drugs: synergistic effects on normal and
neoplastic lymphocytes by addition of doxorubicin and mitoxantrone.
AB - 2-CdA is active as a single agent in the treatment of low-grade lymphomas. We
analyzed the induction of apoptosis by 2-CdA alone (n=5) and in combination with
other drugs in peripheral lymphocytes from 25 patients with leukemic low-grade
lymphomas and from 25 healthy volunteers. 2-CdA was tested in 4 escalating
concentrations (0.05 microg/ml to 0.4 microg/ml). Linear regressions showed a
dose dependent apoptosis rate of 0.29 x microg 2-CdA/ml + 0.11 (r2=0.88, p=0.006)
in normal cells and 0.41 x microg 2-CdA/ml + 0.15 (r2=0.88, p=0.005) in leukemic
cells. Intracellular metabolization of 2-CdA into 2-CdA-5'mono-, -di- and the
active metabolite -triphosphate was analyzed by HPLC and paralleled the dose
dependent increase of apoptosis. The combination of 2-CdA with doxorubicin or
mitoxantrone had a synergistic effect on the induction of apoptosis (p<0.001) in
both normal and neoplastic lymphocytes, whereas 2-CdA plus etoposide or cytosine
arabinoside were only additive. Due to the flat slope of the dose response of 2
CdA concentration on apoptosis we assume that higher in vivo dosages of 2-CdA in
the treatment of low-grade lymphomas may not result in a higher clinical
efficacy. The synergistic lymphocytotoxic effect of 2-CdA combined with
doxorubicin or mitoxantrone may be relevant for new treatment approaches.
PMID- 10784402
TI - Effect of antisense oligonucleotides on CD34+ cells from chronic myeloid
leukemia.
AB - Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder
characterized by a specific hybrid gene BCR-ABL (formed as a result of t(9;22)).
This leads to two possible mRNA usually present in leukemic cells, either B2A2 or
B3A2. Targeting these mRNA by antisense oligonucleotides (AS) might offer the
opportunity to decrease leukemic growth. We have tested the ability of AS to
inhibit the in vitro proliferation of CD34 positive (CD34+) blood cells from 16
patients with newly diagnosed CML. CD34+ cells were isolated by an immunomagnetic
technique and incubated for 16 to 18 hours with an 18 mer AS (0.25 mM). Sense
oligonucleotides served as controls. The effects of AS were evaluated by
clonogenic test (production of CFU-GM). Moreover, colonies were picked out and
studied by RT-PCR to analyse the presence of BCR-ABL transcript. For nine
patients with B3A2 transcript, the median inhibition of CFU-GM formation at day
14 was 64.0 +/- 11.2% (68.0 +/- 11.4% at day 21) and for the seven patients with
a B2A2 transcript: 59.0 +/- 11.4% (72.5 +/- 12.0% at day 21). AS showed no effect
on CD34+ cells from three normal volunteer donor cells. However, for every
patient studied, colonies picked out remained BCR-ABL positive with the RT-PCR
technique.
PMID- 10784403
TI - Telomerase activity in preleukemia and acute myelogenous leukemia.
AB - The development of acute leukemia from preleukemia involves the appearance of
clones with increasing proliferative potential. The studies described here
demonstrate that telomerase activity progressively increases as the bone marrow
cells acquire increasing proliferative potential. This was demonstrated by
measuring telomerase activity in normal bone marrow, in post-treatment lymphoma
marrows with skewed Lyonization, and in MDS and AML marrows. The greater
telomerase activity in myelodysplastic marrow than in normal marrow is not due to
a higher proportion of blast cells or to a higher proliferative rate of the MDS
marrow. These data demonstrate that the increasing proliferative potential of the
marrow which occurs during the development of AML is associated with a
simultaneous increase in telomerase activity.
PMID- 10784404
TI - Priming effects of macrophage colony-stimulating factor on monocytic leukemia
cells in combination with chemotherapy: induction of programmed cell death in
vivo.
AB - Two elderly patients with chronic myelomonocytic leukemia were treated with
cytosine arabinoside (Ara-C) and aclarubicin (ACR) under simultaneous
administrations of macrophage colony-stimulating factor (M-CSF) (CAM), and both
obtained good responses. Examination of apoptosis using flow cytometry revealed
induction of apoptotic death of leukemia cells by CAM in Patient 2, while neither
induction of apoptotic death of leukemia cells nor clinical response were seen
with CAG (Ara-C, ACR, and granulocyte colony-stimulating factor) given prior to
CAM in Patient 1. These findings suggested that chemotherapy combined with
simultaneous administration of M-CSF could effectively reduce monocytic leukemia
cells by inducing programmed cell death.
PMID- 10784405
TI - Induction of TrkA expression by differentiation inducers in human myeloid
leukemia KG-1 cells.
AB - We have recently reported that retinoic acid (RA) induced the expression of trkA,
the high affinity receptor for nerve growth factor (NGF), in human myeloid
leukemia KG-1 cells. In the present study, we report that the expression of trkA
was also induced by several other differentiation inducers, including 1alpha, 25
dihydroxyvitamin D3 (Vit D3), 1-beta-D-arabinofuranosyl cytosine (Ara-C), sodium
butyrate (NaBut), and phorbol 12-myristate 13-acetate (PMA). Interestingly, RA in
combination with NaBut or PMA synergistically induced cellular differentiation as
well as the expression of trkA in KG-1 cells. Furthermore, activation of the
induced trkA receptor by exogenous NGF potentiated the differentiating effects of
RA and NaBut. Our results demonstrated that the induction of trkA is an event
associated with the differentiation of KG-1 cells. Our findings suggest that NGF,
in addition to its pivotal roles in the nervous system, may also play important
roles in hematopoietic differentiation.
PMID- 10784406
TI - The human tartrate-resistant acid phosphatase (TRAP): involvement of the hemin
responsive elements (HRE) in transcriptional regulation.
AB - The biochemical properties and protein structure of the tartrate-resistant acid
phosphatase (TRAP), an iron-containing lysosomal glycoprotein in cells of the
mononuclear phagocyte system, are well known. In contrast, little is known about
the physiology and genic structure of this unique enzyme. In some diseases, like
hairy cell leukemia, Gaucher's disease and osteoclastoma, cytochemically detected
TRAP expression is used as a disease-associated marker. In order to begin to
elucidate the regulation of this gene we generated different deletion constructs
of the TRAP 5'-flanking region, placed them upstream of the luciferase reporter
gene and assayed them for their ability to direct luciferase expression in human
293 cells. Treatment of these cells with the iron-modulating reagents transferrin
and hemin causes opposite effects on the TRAP promoter activity. Two regulatory
GAGGC tandem repeat sequences (the hemin responsive elements, HRE) within the 5'
flanking region of the human TRAP gene were identified. Studies with specific HRE
deletion constructs of the human TRAP 5'-flanking region upstream of the
luciferase reporter gene document the functionality of these HRE-sequences which
are apparently responsible for mediating transcriptional inhibition upon exposure
to hemin. In addition to the previously published functional characterization of
the murine TRAP HRE motifs, these results provide the first description of a new
iron/hemin-responsive transcriptional regulation in the human TRAP gene.
PMID- 10784407
TI - Neoplastic cell activation and proliferative response to CD40-ligand characterize
recurrent leukemic bouts in an unusual case of low grade lymphoma.
AB - Spontaneous fluctuations in activity of low-grade B cell lymphomas are common but
not understood. An explanation may be offered by studying an atypical SLL/CLL
case characterized by recurrent cycles of leukemic phase alternating with
spontaneous remission (1). During remissions, residual IgMkappa+ leukemic cells
exhibited resting phenotype, low proliferative response to CD4O-ligand and
delayed apoptosis. In contrast, the acute phase counterparts were phenotypically
activated, underwent rapid apoptosis in culture and proliferated extensively in
response to membrane-anchored CD40-ligand. Transient bursts of serum TNFalpha and
IL-10 preceded the acute phases, which were characterized by the co-existence of
CD40-ligand+ T lymphocytes and lymphoma cells in the bone marrow. Based on ex
vivo and in-vitro data, we suggest that changes in the lymphoma milieu affect the
neoplastic cell activation status, rate of proliferation in response to activated
T cells and rate of apoptosis. These responses may underlie both the induction
and spontaneous regression of the acute phases in this unique lymphoma. Our
findings raise the possibility that part of this mechanism may have evolved
during transformation of indolent common CLL to its more aggressive form.
PMID- 10784408
TI - Prolonged third remission in a patient with acute promyelocytic leukemia after
consolidation chemotherapy with intermittent intermediate dose ara-C and
maintenance with intermittent all-trans retinoic acid (ATRA).
AB - The benefit of all-trans-retinoic acid (ATRA) in the front line therapy of acute
promyelocytic leukemia (APL) is well established, but its role in postremission
therapy and in the treatment of relapse is currently under investigation.
Moreover, the impact of cytosine arabinoside (Ara-C) in the therapy of APL has
been questioned in recent studies. We report a prolonged third molecular
remission (MR) in a patient with hyperleukocytotic APL after induction with ATRA,
consolidation chemotherapy (CT) with intermittent intermediate dose Ara-C and
maintenance therapy with intermittent ATRA. While the first two remissions were
relatively short (8 months and 11 months, resp.), the duration of the third
continuous CR (49+ months) is more than twice as long as the length of the two
previous remissions combined. In this case Ara-C followed by intermittent ATRA
maintenance was a safe and effective therapy for relapsed disease. A third
molecular remission of such duration and quality is unusual.
PMID- 10784409
TI - Myelodysplasia presenting as granulocytic sarcoma of mediastinum causing superior
vena cava syndrome.
AB - Granulocytic sarcomas (GS) are extramedullary tumor masses of immature myeloid
cells, most frequently associated with hematological disorders including acute
myeloid leukemia (AML), chronic myelogenous leukemia (CML), and myelodysplastic
syndrome (MDS). Recent interest has centered upon the possible biologic
properties that enable theses myeloid cells to adhere to tissues and establish a
tumor mass. GS presenting as a mediastinal mass is relatively infrequent, and
more uncommon is presentation with the superior vena cava syndrome. We present
one such case and review some of the available literature.
PMID- 10784410
TI - Mycobacterium-avium-intracellulare complex infection following 2
chlorodeoxyadenosine therapy for hairy cell leukaemia.
AB - 2-Chlorodeoxyadenosine (2-CdA) is associated with prolonged suppression of CD4
lymphocytes. Cases of tuberculosis or mycobacterium avium intracellulare complex
(MAC) infection complicating 2-CdA administration have not been reported despite
the low CD4 counts. We report a patient with Hairy Cell Leukaemia (HCL) who
developed MAC infection one month following 2-CdA treatment. This patient had
been previously treated with prednisone for Sweets Syndrome. It would appear that
the combination of 2-CdA and prednisone predisposes patients to MAC infection,
and if possible this combination of treatment should be avoided.
PMID- 10784411
TI - Is nitrotyrosine generated in human erythrocytes in circulation?
AB - Nitrotyrosine is considered a stable biomarker of reactive nitrogen species,
including nitrogen dioxide (NO2) and peroxynitrous acid (ONOOH) in biomaterials.
There are inconsistent observations on the detection of free and protein
associated nitrotyrosine in normal human plasma. Human erythrocytes,
differentiated from erythrocyte precursor cells in the bone marrow, circulating
in the body for an average of 120 d, and finally removed by spleen macrophages,
may be exposed to reactive nitrogen species. In the present study, membrane
proteins and hemoglobin from the senescent erythrocyte population were compared
with those from young erythrocytes separated from the same individuals in their
nitrotyrosine presence using newly prepared rabbit polyclonal anti-nitrotyrosine
ribonuclease A and anti-nitro(N-butoxycarbonyl)tyrosine-bovine serum albumin
antibodies. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the
membranes and hemoglobin, and subsequent Western blot analysis, showed that these
antibodies only slightly bind to the bands of the proteins from both young and
senescent erythrocytes, whereas these antibodies definitely bind to the protein
bands of membranes and hemoglobin nitrated by NO2 or ONOOH in vitro. This result
indicates that nitrotyrosine is not detected in the membrane proteins and
hemoglobin in human normal erythrocytes in circulation. However, this does not
conclude that erythrocytes are not exposed to reactive nitrogen species in the
circulation.
PMID- 10784412
TI - A novel Van91 I polymorphism in the 1st intron of the parathyroid hormone
(PTH)/PTH-related peptide (PTHrP) receptor gene and its effect on the urinary
cAMP response to PTH.
AB - This study was designed to identify a parathyroid hormone (PTH)/PTH-related
peptide (PTHrP) receptor gene polymorphism in a healthy Japanese population. All
known 13 introns of this gene were amplified by PCR, except the 1st intron, which
was amplified by the long-PCR method. No restriction fragment length
polymorphisms (RFLPs) were detected by BsmI or XbaI in any of these introns.
Twenty-one other restriction enzymes (Hind III, Bgl II, Sty I, Pvu II, Eco81 I,
Van91 I, BstX I, Sse8387 I, EcoR I, BamH I, Mbo II, Tth111 I, PshA I, Eam1105 I,
Not I, Srf I, Bgl I, Fok I, Sfi I, Apa I, Taq I) were tested on the 1st intron.
Furthermore, digestion by Van911 (CCANNNNNTGG) identified a single, two-allele
polymorphism with a fragment of approximately 3.5 kb (V allele) or a fragment of
3.1 and 0.4 kb (v allele). The frequency of the Van91 I polymorphism in 106
healthy Japanese volunteers was 77.4% for type vv, 19.8% for type Vv and 2.8% for
type VV. In addition, the urinary cAMP response to exogenous [1-34]PTH was
studied in 17 healthy volunteers and found to be significantly greater in persons
with type Vv than type vv (p<0.05). In conclusion, the Van91 I polymorphism of
the PTH/PTHrP receptor gene can be used to study the role of polymorphism in
various disorders involving PTH or PTHrP.
PMID- 10784413
TI - Some factors which influence intrinsic factor content and its mRNA level in the
rat stomach.
AB - Factors which regulate Intrinsic Factor (IF) content and IF mRNA level were
examined with an abc-ELISA and Northern blot analysis in growing rats, and
compared with pepsinogen (Pg) and in terms of the increased need for vitamin B12
(V.B12). Increases in IF content and IF mRNA level gradually occurred from day 13
after birth, whereas those of Pg and Pg mRNA started from day 16. The effects of
a few related hormones on the expression of IF mRNA were examined. The injection
of hydrocortisone induced IF and Pg mRNA expression in 5-d-old postnatal rats.
Furthermore, adrenalectomy-induced decreases in IF content and IF mRNA level in
adult male rats were recovered with hydrocortisone administration. IF content and
IF mRNA level were measured in the artificially and physiologically created needs
for V.B12, the first being regeneration of the liver, the V.B12 storing tissue,
following partial hepatectomy, and the second pregnancy or lactation. During
regeneration of the liver, increases in IF content and IF mRNA level were marked,
followed by reduction toward the original level after accomplishment of
regeneration. Increases in IF content and IF mRNA level were also seen in
lactating rats, but no increases were obtained in pregnant rats. These results
suggest that the IF content and IF mRNA level are regulated not only by
corticosteroids but also by the increased need for V.B12.
PMID- 10784414
TI - Distribution of a major lysosomal membrane glycoprotein, LGP85/LIMP II, in rat
tissues.
AB - We previously identified and characterized a major lysosomal membrane
glycoprotein, termed LGP85 (identical to LIMP II), in rat liver lysosomes. This
study describes the distribution of the mRNA and protein of LGP85 in rat tissues.
LGP85 protein and mRNA were detectable in all tissues when analyzed by Western
and Northern blotting. The 4.2- and 2.2-kb transcripts of LGP85 were detected in
all tissues. Liver and lung have the highest and lowest levels of LGP85 mRNA,
respectively. A single protein band with an apparent molecular weight (Mr) of
approximately 85000 was detected in each tissue. The specific protein content of
LGP85 in spleen was markedly higher than in other tissues. LGP85 protein is
distributed in the tissues independently of LGP85 mRNA. Furthermore, there was a
less significant relationship between LGP85 protein and another lysosomal
membrane glycoprotein, lamp-1, in the tissue distribution (a regression
coefficient of 0.086), which suggests that LGP85 may function in vivo
independently of lamp-1.
PMID- 10784415
TI - Involvement of NF-kappaB in the protection of cell death by tumor necrosis factor
in L929 derived TNF resistant C12 cells.
AB - The Tumor necrosis factor (TNF)-resistant C12 cell line was established by
continuous exposure of a toxic concentration of TNF to parental murine
fibrosarcoma L929 cells. Introduction of the cytosolic phospholipase A2 (cPLA2)
gene to C12 cells resulted in restoration of the TNF sensitive phenotype (CPL4
cells). DNA ladder formation and nuclear condensation by TNF exposure suggested
that TNF induced apoptotic cell death in L929, C12 and CPL4 cells. TNF-induced
activation of transcription factor nuclear factor-kappaB (NF-kappaB) was observed
in all 3 cell lines. The activation reached the maximum level at 30 min after the
exposure to TNF and thereafter declined slowly. The amount of activated NF-kappaB
in C12 cells was about twice as high as that of L929 cells with either dose of
TNF tested in this study. It was found that C12 cells expressed latent NF-kappaB
twice that of L929 cells. This abundance of latent NF-kappaB would provide a
higher response of NF-kappaB in C12 cells. Pretreatment with the known potent NF
kappaB inhibitor pyrolidine dithiocarbamate (PDTC) profoundly suppressed the
activation of NF-kappaB induced by TNF and potentiated TNF cytotoxicity in all 3
cell lines. These results are consistent with the recently found anti-apoptotic
action of NF-kappaB and suggest that NF-kappaB acts as an acquired TNF resistant
factor in C12 cells.
PMID- 10784416
TI - Comparison of the antidiarrheal effects of zaldaride maleate and its optical
isomers in rats.
AB - Zaldaride maleate (ZAL), a calmodulin inhibitor, that ameliorates secretory
diarrhea in rodents, has a racemic structure. In this study, we compared the
antidiarrheal and antisecretory effects of ZAL and its optical isomers, R(-)
isomer and S(+)-isomer, in rats. In Ussing chamber experiments, the inhibitory
action of ZAL on acetylcholine-induced ion transport in the rat colonic mucosa
was equipotent for both optical isomers, with IC50 values of approximately 3--4
micromol/l. In castor-oil-induced diarrhea, ZAL and its S(+)-isomer inhibited the
incidence of diarrhea, whereas the R(-)-isomer had no effect. In 16,16-dimethyl
prostaglandin E2-induced diarrhea, ZAL, the S(+)-isomer and the R(-)-isomer
significantly ameliorated diarrhea at doses of 30, 10 and 30 mg/kg (p.o.),
respectively; the ED50 values were 25, 10 and above 30 mg/kg (p.o.),
respectively. The pharmacokinetic parameters after administration of 30 mg/kg
(p.o.) of each compound were as follows: ZAL (Cmax: 378 ng/ml, AUC0-12: 1650 ng
h/ml); S(+)-isomer (Cmax: 565 ng/ml, AUC0-12: 2230 ng-h/ml) and R(-)-isomer
(Cmax: 271 ng/ml, AUC0-12: 613 ng-h/ml) (mean, N=4). In conclusion, despite the
fact that the antisecretory actions of ZAL and its optical isomers are the same,
the antidiarrheal actions of ZAL and its S(+)-isomer are more potent than that of
the R(-)-isomer. The antidiarrheal actions of ZAL and its optical isomers may be
related to plasma levels.
PMID- 10784417
TI - Focal cerebral ischemia-induced escape deficit in rats is ameliorated by a
reversible inhibitor of monoamine oxidase-a: implications for a novel animal
model of post-stroke depression.
AB - The present investigation was conducted to examine whether a reversible inhibitor
of monoamine oxidase (MAO)-A, T-794, affects the shuttle-box escape deficit
induced by transient middle cerebral artery (MCA) occlusion (MCAO). MCA-occluded
and sham-operated rats (surgery on day 0) were subjected to daily shuttle-box
session from day 7 to 9 (training series) and from day 13 to 15 (test series) and
received twice daily administration of T-794 (10 mg/kg p.o., b.i.d.) or vehicle
from the evening of day 9. In the final shuttle-box session of test series (day
15), while MCA-occluded-vehicle-treated rats showed significantly more escape
failures than sham-operated-vehicle-treated rats, the failures made by MCA
occluded rats were significantly decreased by T-794 to the level of the sham
operated group. Additionally, biochemical examination was conducted after
behavioral evaluation to examine possible involvement of the brain monoamine
system in the observed behavioral syndrome. In occluded hemisphere of MCA
occluded rats, catecholamine levels were decreased and ratios of deaminated
metabolite to corresponding monoamine were increased compared with the respective
values of the sham-operated group, and these changes were reversed by T-794.
Results are discussed in terms of possible relevance of the MCAO-induced escape
deficit to post-stroke depression.
PMID- 10784418
TI - Reduction of electrically evoked neural activity by ginseng saponin in rat
hippocampal slices.
AB - It is well established that ginseng saponin has positive influences on various
neural diseases, but little is known about its electrophysiological effects in
the central nervous system. In this study, we examined the electrophysiological
effects of ginseng saponin in rat hippocampal slices. Total saponin from ginseng
root reduced the slope of fEPSPs (field excitatory postsynaptic potentials) in
the CA1 area in a dose-dependent manner (9.1 +/-5.4%, 48.4+/-12.1%, and 60.5+/
15.3% at 10, 50, and 100 microg/ml, respectively), which was reversed within 10
min of washout. Seven different ginsenosides resulted in varied degrees of fEPSPs
reduction. The rank order of reduction was Rb1, Rg1 >Rg2, Rh1, Rc>Rd, Re within a
range of 5-64% reduction. No difference in the suppressive action between
protopanaxadiol (Rb1, Rc, Rd) and protopanaxatriol (Rg1, Rg2, Re, Rh1) saponins
was shown; the slope of fEPSPs was reduced by 38% and 40% on average,
respectively. The possible role of gamma-aminobutyric acid (GABA(A)) receptor in
the suppressive action of ginseng saponins was tested using whole cell patch
recording in acutely isolated hippocampal neurons. Ginsenosides did not induce
chloride current nor modified GABA-induced current. Also, the suppressive effect
of ginsenosides on fEPSPs was still observed in the presence of the GABA(A)
receptor antagonist, bicuculline methiodide 50 microM. These results suggest that
the suppressive effect is not attributable to regulation of GABA(A) receptor
activation.
PMID- 10784419
TI - Alteration in membrane fluidity of rat liver microsomes and of liposomes by
protoporphyrin and its anti-lipidperoxidative effect.
AB - The effect of protoporphyrin (PP) on membrane fluidity was investigated by
electron paramagnetic resonance spectroscopy using doxyl stearate spin probes in
relation to the anti-lipidperoxidative effect of PP. PP decreased the membrane
fluidity in rat liver microsomes at concentrations above 1 mM and also in
phosphatidylcholine (PC)-cholesterol (Cho) (100:8, a molar basis) liposomes. The
lipid peroxidation stimulated by Fe2+ and L-ascorbic acid in those membrane
preparations was attenuated along with the decrease in membrane fluidity by PP.
Similar results were also found in Cho-rich PC (100:30 to 100) liposomes having
less fluidity. These results suggest that the decrease in the membrane fluidity
caused by PP may be involved in the antioxidative action of PP.
PMID- 10784420
TI - Activation of NF-kappaB determines the sensitivity of human colon cancer cells to
TNFalpha-induced apoptosis.
AB - Tumor necrosis factor alpha (TNFalpha) generates a potent cytotoxic effect,
however many cancer cells are resistant to TNFalpha-mediated killing and the
cause of the differential sensitivity remains to be elucidated. In this study, we
demonstrated that TNFalpha induced cell death in four different human colon
cancer cell lines. The degree of cytotoxic effect was different in each cell
line, in that HCT-15 was relatively sensitive, while DLD-1, HT-29 and WiDr were
relatively resistant. TNFalpha induced apoptotic changes such as morphological
changes, DNA fragmentation and activation of caspase-3 in HCT-15, but to a lesser
degree in the others. Transcriptional expression of TNFR1(p55), as well as that
of FLICE, Fas, FADD, DR3, FAF, TRADD, and RIP was similar in these cell lines,
indicating that the susceptibility to TNFalpha-induced apoptosis may not be
determined by the constitutive expression level of these factors. Interestingly,
the cytotoxic effect of TNFalpha was well correlated with the DNA binding
activity of NF-kappaB in the colon cancer cell lines. Further, the overexpression
of a non-phosphorylated mutant form of IkappaBalpha enhanced the cytotoxicity of
TNFalpha in the resistant cell line, DLD-1, indicating that NF-kappaB activity
may determine the sensitivity of colon cancer cells to TNFalpha-induced
apoptosis. Thus, our results indicate that modulation of NF-kappaB activity may
provide a useful tool to sensitize colon cancer cells to TNFalpha treatment.
PMID- 10784421
TI - Depressor effect of wheat germ hydrolysate and its novel angiotensin I-converting
enzyme inhibitory peptide, Ile-Val-Tyr, and the metabolism in rat and human
plasma.
AB - We report here the antihypertensive effect of wheat germ (WG) hydrolysate and its
dominant peptide, Ile-Val-Tyr (IVY), with potent angiotensin I-converting enzyme
(ACE) inhibitory activity. The toxicity test of AG50W fraction purified from the
WG hydrolysate and IVY in ddy mice revealed that 1 week median lethal
concentrations of AG fraction and IVY were less than 100 and 10 mg/kg,
respectively. As a result of an intravenous administration test of both
inhibitors in spontaneously hypertensive rat (SHR), the mean arterial blood
pressure (MAP) significantly decreased with the dose; the MAP reduction of 10.3
and 19.2 mmHg was observed at a dose of 50 mg/kg of AG fraction and 5 mg/kg of
IVY, respectively. In addition to this behavior, the MAP gradually decreased
after the 5 mg/kg of IVY injection (time to give a maximum reduction; 8 min), and
the reduction was held for 20 min. By using rat and human plasma, IVY was found
to be metabolized by the action of aminopeptidase in plasma to form a subsequent
ACE inhibitor, Val-Tyr (VY). Thus, the intake of IVY as a physiologically
functional food would serve in the lowering of blood pressure (BP) by the
combined depressor effect of itself and its metabolite after the absorption.
PMID- 10784422
TI - Reproducible biphasic cutaneous edema induced by topical and repeated application
of antigen in sensitized mice.
AB - An allergic dermatitis model was developed by repeated sensitization and
challenge with antigen (ovalbumin, OA) over 7 months in mice. ddY mice were
sensitized by i.p. injection of OA adsorbed on Al(OH)3 (1 microg OA/2 mg
Al(OH)3/animal) once every 3 weeks. Antigen challenge was conducted by injection
of OA solution (0.1, 1 and 10 microg/site) into the skin of the hind paw instep
10 d after the respective sensitizations. At the 1st challenge, all the 3 groups
showed an immediate edematous response with the peak at 30 min or 1 h after the
challenge. The group challenged with the highest dose (10 microg/site) of the
antigen developed a clear late-phase edema, which was observed at the 2nd
challenge, increasing until the 3rd challenge, reaching a plateau at further
challenges. On the other hand, such late phase edema scarcely developed in the
group challenged with the lowest dose (0.1 microg/site) of the antigen. The
amount of circulating specific IgE antibody increased following repeated
sensitizations and challenges in all groups, but there were no significant
differences in the levels among them. Mepyramine suppressed the early edema by
approximately 50%, yet the late phase edema was unaffected. In conclusion, using
Al(OH)3+antigen for sensitization and an appropriate amount of antigen for
challenge, reproducible biphasic edematous responses were observed long-term
without desensitization. This model may be classified as an acute allergic
dermatitis and can be useful for quantitatively evaluating the effects of anti
allergic drugs.
PMID- 10784423
TI - Biochemical characterization of bovine lactoferrin as a glycyrrhizin-binding
protein in vitro.
AB - Lactoferrin (LF) from bovine colostrum was biochemically characterized as a
glycyrrhizin (GL)-binding protein (gbP) in vitro. It was found that (i) bovine LF
(bLF) and a synthetic bovine lactoferricin (bLFcin, the N'-terminal region of bLF
at the positions 17--41) had a high affinity to a GL-affinity column; (ii)
approximately 1.8 moles of GL were bound to a molecule of bLF with a binding
constant of approx. 1.20x10(4) M(-1) at pH 6.8; and (iii) GL, but not
glycyrrhetinic acid (GA), induced a conformational change of bLF. In addition,
the glucuronic acid moiety of the GL molecule was found to be responsible for
binding to bLF, because (i) no binding of GA and two glucoses-GA (Glc-Glc-GA) to
bLF was detected; and (ii) a synthetic fluorinated GL (GlcA-GlcF-GA) and mono
glucuronyl-GA (mono-GlcA-GA) were bound significantly to bLF. A similar binding
of GL to human LF (hLF) was also observed under the same experimental conditions.
Data provided here suggest that (i) bLF contains plural GL-binding sites; and
(ii) the specific binding of GL to bLF may modulate the physiological activity of
bLF in vivo.
PMID- 10784424
TI - Pharmacokinetics of diethylcarbamazine: prediction by concentration in saliva.
AB - The concentration of diethylcarbamazine in saliva was used to determine
pharmacokinetic parameters, in comparison to plasma and urine concentrations. Six
healthy adult male volunteers were administered 150 mg diethylcarbamazine with
400 ml of water. At seven different time intervals, blood, urine and saliva
samples were taken, and different pharmacokinetic parameters measured. The plasma
saliva concentration ratio was calculated as 1.53 whereas the observed ratio was
3.82. The half lives, times to reach peak plasma concentration, and elimination
rate constants did not show any significant difference in the different samples.
The plasma peak concentration and areas under the curve were significantly
(p<0.05) increased from those of the saliva. At 24 h, when diethylcarbamazine was
absent in urine, the plasma and saliva concentrations were almost zero.
Diethylcarbamazine is secreted in saliva, and its concentration in saliva can be
used to monitor drug therapy.
PMID- 10784425
TI - Potentiation of acetaminophen hepatotoxicity by doxapram in mouse primary
cultured hepatocytes.
AB - The augmentation by doxapram (DOP) of the reduction in viability and of the
apoptosis of cells induced by acetaminophen (AA) was examined in mouse primary
cultured hepatocytes. Loss of viability on exposure to AA and/or DOP in cultured
hepatocytes was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium
bromide (MTT) assay and the apoptosis of cultured hepatocytes was detected by
nuclear morphologic observation and from a ladder-like DNA fragmentation pattern.
The combination of AA (5 mM) and DOP (10, 20, 50 or 100 microM) potentiated the
reduction in cell viability and increased the oxidative stress. Hepatocytes
exposed for 24 h to AA (5 mM) plus DOP (100 microM), showed atrophy of nuclei,
including chromatin condensation and a ladder-like DNA fragmentation pattern,
characteristic of apoptosis. Benzyl-oxycarbonyl-Asp-CH2OC (O)-2,6-dichlorobenzene
(Z-Asp-CH2-DCB, 50 microM), an inhibitor for caspases, improved the viability and
ladder-like DNA fragmentation in cells exposed to DOP (200 or 500 microM) alone
or AA ( 5 mM) plus DOP (100 microM). However, loss of viability on exposure to a
high concentration of AA (10 mM) and ladder-like DNA fragmentation were not
affected by Z-Asp-CH2-DCB. These results indicated that the synergistic increase
in oxidative stress, activation of caspases and DNA fragmentation induced by DOP
potentiated the hepatotoxicity of AA.
PMID- 10784426
TI - Two flavonoids from the leaves of Morus alba induce differentiation of the human
promyelocytic leukemia (HL-60) cell line.
AB - Two flavonoids, quercetin-3-O-beta-D-glucopyranoside (1) and quercetin-3,7-di-O
beta-D-glucopyranoside (2), were isolated from the leaves of Morus alba
(Moraceae). These two flavonoids exerted a significant inhibitory effect on the
growth of the human promyelocytic leukemia cell line (HL-60) at the concentration
of 2 x 10(-4) M. Compound 2 also induced differentiation of the HL-60 cell line
to express CD 66b and CD 14 antigens. These flavonoids exhibited significant free
radical scavenging effects on 1,1-diphenyl-2-picryl-hydrazyl radical.
PMID- 10784427
TI - Hepatoprotective effect of Combretum quadrangulare and its constituents.
AB - The MeOH extract of leaves of Combretum quadrangulare showed significant
hepatoprotective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)
induced experimental liver injury in mice and on D-GalN/tumor necrosis factor
alpha (TNF-alpha)-induced cell death in primary cultured mouse hepatocytes.
Phytochemical investigation led to the isolation of thirty cycloartane-type
triterpenes together with betulinic acid, beta-sitosterol, beta-sitosterol
glucoside, 4 flavones (34-37), and 3 flavone C-glucosides (38-40). These
compounds showed various potencies of hepatoprotective effect on D-GalN/TNF-alpha
induced cell death in primary cultured mouse hepatocytes. Quadrangularol B (29),
methyl quadrangularate I (33), kamatakenin (34), 5,7,4'-trihydroxy-3,3'
dimethoxyflavone (35), 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (36) and
isokaempferide (37) showed strong inhibitory effect on TNF-alpha-induced cell
death with IC50 values of 34.3, 33.7, 13.3, 22.4, 13.4 and 22.8 microM,
respectively, whereas clinically-used silibinin had an IC50 value of 39.6 microM
and glycyrrhizin showed very weak inhibitory effect. Methyl quadrangularates A
(30) and N (32), norquadrangularic acid B (31) and vitexin (40) also showed
potent inhibition on TNF-alpha-induced cell death with IC50 values of 45.7, 89.3,
67.6 and 40.1 microM, respectively. The flavonoids and some of the cycloartane
type triterpenes appeared to be the hepatoprotective principles of the leaves of
C. quadrangulare.
PMID- 10784428
TI - Physiological change after local injection of liposomes containing tumor necrosis
factor (TNF).
AB - After the local (subcutaneous) administration of tumor necrosis factor-alpha
(TNF), two types of physiological change were clearly observed in dogs. One was a
systemic change, the other was a local change at the injected site. Solution,
negatively charged liposome and positively charged liposome were locally injected
in dogs. Even with local administration, the increase of triglyceride in plasma
and the decrease of blood pressure were the most serious after administration of
the solution. These changes were typical systemic side effects of TNF.
Consequently, liposomes suppressed these serious systemic side effects of TNF
after a local administration. Another physiological change was irritation at the
injected site. However, after administration of positively charged liposome, the
lowest irritation at the injected site was observed, along with the highest local
concentration of TNF. We reported the superior antitumor effect of positively
charged liposomes in solution, as well as the lowest systemic circulation after
an intratumor administration. Therefore, it was speculated that a positively
charged liposome directly acted on the tumor cells without TNF release. These
results exhibited the potency of liposomal delivery of TNF with local
administration.
PMID- 10784429
TI - Inhibitory effect of dexamethasone palmitate-low density lipoprotein complex on
low density lipoprotein-induced macrophage foam cell formation.
AB - We used low density lipoprotein (LDL) as a carrier of site-specific delivery of
drugs to atherosclerotic lesions, prepared a dexamethasone palmitate (DP)-LDL
complex, and examined the effect of the DP-LDL complex on foam cell formation of
macrophages in vitro. LDL was isolated from human plasma and the DP-LDL complex
was prepared by incubation in the presence of Celite 545. The complex contained
about 50 mol of DP in 1 mol of LDL. When macrophages were incubated with LDL for
48 h, cholesterol ester was accumulated in the macrophages, indicating foam cell
formation. This accumulation of cholesterol ester was significantly inhibited by
incubation with the DP-LDL complex. The potency of the DP-LDL complex was similar
to that of dexamethasone alone. The DP-LDL complex also significantly attenuated
the accumulation of cholesterol ester induced by incubation with LDL prior to the
incubation with the DP-LDL complex. These findings indicated that the DP-LDL
complex showed similar characteristics to LDL, and the DP-LDL complex inhibited
the foam cell formation of macrophages in in vitro experiments. This DP-LDL
complex has a possibility as a drug-carrier complex for use in atherosclerosis.
PMID- 10784430
TI - Absorption, distribution and excretion of galactosyl-beta-cyclodextrin and
mannosyl-beta-cyclodextrin in rats.
AB - Microanalytical methods were developed for measuring galactosyl-beta-cyclodextrin
(Gal-betaCD) and mannosyl (Man)-betaCD in biological matrices of the rat by HPLC
with pulsed amperometric detection. Then, using these methods, the absorption,
distribution and excretion of intravenously and orally administered Gal-betaCD
and Man-betaCD were determined in rats, and compared with those of glucosyl (Glc)
betaCD. The pharmacokinetic behavior of Gal-betaCD, Man-betaCD and Glc-betaCD
after intravenous administration (50 mg/kg) was very similar. Within 6 h after
intravenous administration, unchanged Gal-betaCD and Man-betaCD recovered in
urine accounted for about 90% of each dose. After oral administration (500
mg/kg), 0.37% and 0.38% of Gal-betaCD and Man-betaCD, respectively, were excreted
in urine. After intravenous and oral administration of Gal-betaCD and Man-betaCD,
the decomposition of Gal-betaCD and Man-betaCD to betaCD in the urine, kidney and
liver was greater than that of Glc-betaCD. The sum of the molar concentrations of
branched CDs and their decomposition product, betaCD, in the liver at 4 h after
intravenous administration of Gal-betaCD and Man-betaCD was greater than that of
Glc-betaCD. Furthermore, the inclusion complexes of estriol and betamethasone
with Gal-betaCD, Man-betaCD and Glc-betaCD were prepared and their absorption was
evaluated after oral administration in rats. The plasma concentrations of the
drugs after oral administration of drug-Gal-betaCD and drug-Man-betaCD complexes
were the same as those after the administration of drug-Glc-betaCD complexes.
PMID- 10784431
TI - Influence of N-terminal peptide and oligosaccharide on the clearance of t-PA.
AB - We have studied the influence of Gly-Ala-Arg peptide at the N-terminus and the
oligosaccharide at Asn184 on the clearance of tissue plasminogen activator (t
PA). In order to intensify the influence of these structural features, Gln117 t
PA, which is a mutant tissue plasminogen activator (mt-PA) expressed in mouse
C127 cells, was used for the investigation. It is altered to remove a high
mannose type oligosaccharide by the mutation of an amino acid from Asn117 to Gln.
We isolated 4 variants of Gln117 t-PA by cation-exchange chromatography, which
are abbreviated as S-I, S-II, L-I and L-II. These variants originated from the
heterogeneity of the peptide chains (S-chain, 527 amino acids, L-chain, 530 amino
acids) and oligosaccharide (Type I, 2 oligosaccharides, Type II, 1
oligosaccharide). Pharmacokinetics of these variants were investigated after
single intravenous administration to male rats at a dose of 250 microg/kg.
Significant differences in pharmacokinetic parameters were observed among these
variants, but there was no considerable difference in fibrin clot lysis time
(FCLT) activity. Gly-Ala-Arg peptide at the N-terminus increased the CLt, whereas
the oligosaccharide at Asn184 decreased the CLt. Moreover, the effects of the N
terminal peptide and the oligosaccharide on the CLt were independent of each
other. Our study with Gln117 t-PA revealed the role of the N-terminal peptide
found in the L-chain produced during the processing of t-PA precursor.
PMID- 10784432
TI - Pharmacokinetics of aniracetam and its metabolites in rat brain.
AB - The pharmacokinetics of aniracetam (AP) and its main metabolites, 4-p
anisamidobutyric acid (ABA), 2-pyrrolidinone (PD) and p-anisic acid (AA), in 3
brain regions (cerebral cortex, hippocampus and thalamus) was investigated after
single intravenous (i.v.) and oral administrations of AP to rats. AP, AA and PD
were rapidly distributed into the 3 brain regions after i.v. administration of
AP, but the amounts of AP were low. The concentrations of AP and AA in brain
regions rapidly declined, whereas PD levels were higher and more sustained than
those of AP and AA. ABA levels in the regions were below the detection limit.
There were no significant differences in the distribution of these compounds in
the 3 brain regions. The AUCbrain/AUCplasma ratio of PD was 53--55%, in contrast
to the low ratio of AP (2.4--3.2%) and AA (3.9--4.2%). On oral administration of
AP, the AUCbrain/AUCplasma ratio of PD was also higher than that of AA. When the
transport of PD was tested using the in situ brain perfusion technique, it was
clarified that PD was not transported across the blood-brain barrier (BBB) by a
neutral amino acid carrier system. The high brain levels of PD and the low levels
of AP suggest that the clinical efficacy of dosed AP may partly result from PD
penetrating into the brain.
PMID- 10784433
TI - In vitro cytotoxicity of cis[((1R,2R)-1,2-cyclohexanediamine-N,N')bis(myristato)]
platinum(II) suspended in lipiodol in rat hepatoma AH-109A cells and human tumor
cell lines.
AB - SM-11355, cis[((1R,2R)-1,2-cyclohexanediamine-N,N ')bis(myristato)] platinum(II),
is a lipophilic platinum complex. SM-11355 suspended in Lipiodol (SM
11355/Lipiodol) was shown to have antitumor activity against hepatic tumors after
intra-hepatic arterial administration in animal models. In this study, the in
vitro growth inhibitory activities of SM-11355 and cisplatin (CDDP) following 7-d
drug exposure were examined using rat ascite hepatoma AH-109A cells and various
human tumor cell lines. In monolayer or suspension cell cultures, SM-11355 did
not inhibit the cell growth, whereas SM-11355/Lipiodol had dose-dependent growth
inhibitory activities, as did CDDP suspended in Lipiodol (CDDP/Lipiodol). This
was also the case in the colony formation assay in agarose gel. CDDP/Lipiodol
released platinum compound into the culture medium rapidly, whereas SM
11355/Lipiodol released it slowly but constantly for 7 d. Furthermore, a
significant amount of platinum was detected in the cells treated with
CDDP/Lipiodol and SM-11355/Lipiodol. These results suggest that Lipiodol plays an
important role in the in vitro cytotoxicity of SM-11355, and certain platinum
compounds released from SM-11355/Lipiodol have growth inhibitory effects on these
cells.
PMID- 10784434
TI - Comparison of anthocyanin distribution in different blueberry sources by
capillary zone electrophoresis.
AB - Capillary zone electrophoretic separation of blueberry anthocyanins was studied
using a Na-borate buffer containing trans-1,2-diaminocyclohexane-N,N,N',N'-tetra
acetic acid monohydrate (CyDTA) as the carrier buffer. The separation conditions
were precisely examined using an aqueous extract of bilberry (wild type
blueberry) as the separation sample which is rich in this type and amount of
anthocyanins. Each separated peak was identified by comparing the mobility with
that of anthocyanin standards after normalization against the mobility of
malvidin 3-o-glucoside (Mv 3-Glc) added as an internal standard. As salt
concentrations of the running buffer increased, the peak resolution was markedly
improved over the whole range of separation, especially, among the fast moving
components (petunidin 3-glucoside, cyanidin 3-glucoside and malvidin 3
galactoside). Inversely, the peak separation both between petunidin 3-glucoside
and peonidin 3-glucoside, and between delphinidin 3-glucoside and petunidin 3
galactoside, respectively, were decreased. The anthocyanins were, however,
successfully separated by decreasing the buffer pH. Good separation of
anthocyanins was finally achieved by 30 mM Na-borate (pH 8.78) containing 7.5 mM
CyDTA within 10 min. Under this separation condition, anthocyanins from different
blueberry sources were analyzed. The results revealed that different blueberry
sources had their own patterns of anthocyanin distribution and amounts in the
extracts, thus the present method is suitable for the quality control of
anthocyanin-containing food materials.
PMID- 10784435
TI - Inhibition of drug-metabolizing enzyme activity in human hepatic cytochrome P450s
by bisphenol A.
AB - Effect of bisphenol A on drug-metabolizing enzyme activities by human hepatic
cytochrome P450s (CYP) was investigated. We measured aminopyrine N-demethylation
by eleven kinds of cDNA-expressed CYPs. CYP2C19 and CYP2B6 catalyzed most
efficiently the aminopyrine N-demethylation, followed by CYP2C8 and CYP2D6.
Bisphenol A (1 mM) most efficiently inhibited aminopyrine N-demethylation by
CYP2C8 and CYP2C19 by 82% and 85%, respectively, whereas inhibition of the
activities by CYP 2B6 and 2D6 was less than 40%. Bisphenol A exhibited a
noncompetitive-type inhibition of aminopyrine N-demethylase activity by CYP2C8
with Ki value of 97 microM. Additionally, we investigated the inhibitory effect
of bisphenol A on CYP2C19-mediated S-mephenytoin 4-hydroxylation. Bisphenol A
exhibited a mixed-type inhibition with Ki value of 113 microM. These results
suggest that bisphenol A inhibits human hepatic CYP activities, especially CYP2C8
and CYP2C19.
PMID- 10784436
TI - Most clot-bound thrombin activity is inhibited by plasma antithrombin during clot
aging, but a very small fraction survives.
AB - Inhibitory effects of thrombin inhibitors against clot-bound thrombin have been
evaluated using clots prepared from human plasma as the source of clot
immobilized active enzyme, and the clot-bound thrombin has been reported to be
protected from its inhibition by antithrombin. However, we found that the clot
bound thrombin was not intrinsically protected from inhibition by antithrombin,
i.e., a large fraction of initially active clot-bound thrombin was inhibited by
antithrombin present in human plasma time dependently, and only very small
fractions (0.04--0.08%) of the thrombin retained their enzymatic activity after
clot-aging. These results suggest that the extent of clot-aging determines the
sensitivity of clot-bound thrombin to antithrombin, and that inhibitory effects
of drugs against clot-bound thrombin in vitro must be interpreted with caution to
estimate their effects in vivo.
PMID- 10784437
TI - Stereoselective internal acyl migration of 1beta-O-acyl glucuronides of
enantiomeric 2-phenylpropionic acids.
AB - Internal acyl migration reactions of 1beta-O-acyl glucuronides of 2-arylpropionic
acids (profens) are of interest because of their possible role in covalent
binding to serum proteins and consequent allergic reactions. The stereoselective
degradation of 1beta-O-acyl glucuronides of enantiomeric 2-phenylpropionic acids
(PAs), the basic structures of profens, in phosphate buffer (pH 7.4) at 37
degrees C, has been investigated using HPLC. Apparent first-order degradation of
1beta-O-acyl glucuronide and the sequential appearance of 2-, 3- and 4-O-acyl
isomers were observed for each enantiomer. Acyl migration was observed to
predominate over hydrolysis as in the other profen glucuronides. All the
positional isomers and anomers were characterized using NMR and HPLC-NMR. The
overall degradation half-life of (R)- and (S)-PA glucuronides was 1.8 and 3.3 h,
respectively. These results suggest that (R)-PA glucuronide could be more
susceptible to covalent binding to proteins via acyl migration than the
corresponding antipode. The lability of the (R)-diastereomer over the antipode is
consistent with previous reports on other profen glucuronides. Thus, the
diastereomeric PA glucuronides are considered to be the best model compounds for
the computation of structural physicochemical parameters to control the
stereoselective internal acyl migration of profen glucuronides because PA has the
simplest chemical structure of all the profens.
PMID- 10784438
TI - Inhibition of DNA topoisomerases by nidulalin A derivatives.
AB - Three cytotoxic dihydroxanthone derivatives, nidulalin A(1), F390B(2), and
F390C(3) were evaluated for inhibitory activity against DNA topoisomerases.
Compounds 1 and 2 inhibited DNA topoisomerase II with IC50 values of 2.2 microM
and 16 microM, and 3 inhibited DNA topoisomerase I with an IC50 value of 5.9
microM.
PMID- 10784439
TI - Modulators of tumor necrosis factor alpha production bearing dicarba-closo
dodecaborane as a hydrophobic pharmacophore.
AB - Previous studies on the structural development of tumor necrosis factor alpha
(TNF-alpha) production regulators derived from thalidomide (N-alpha
phthalimidoglutarimide) revealed that a hydrophobic substituent at the nitrogen
atom of the phthalimide ring is critical for potent activity. We have designed
and prepared phthalimide derivatives bearing a boron cluster, dicarba-closo
dodecaborane (carborane), which has a hydrophobic character and spherical
geometry, as a novel candidate of biological response modifiers. These compounds
were shown to regulate TNF-alpha production by HL-60 cells, as expected. The
result provides a further example of the application of carborane as a
hydrophobic pharmacophore of biologically active molecules.
PMID- 10784440
TI - Inhibition of cyclooxygenase-2 expression by diarylheptanoids from the bark of
Alnus hirsuta var. sibirica.
AB - Two known diarylheptanoids, oregonin (1), (5S)-1,7-bis-(3,4-dihydroxyphenyl)
heptane-3-one-5-O-beta-D-xylopyranosi de and hirsutanonol (2), (5S)-1,7-bis-(3,4
dihydroxyphenyl)-5-hydroxyheptane-3-one isolated from the bark of Alnus hirsuta
var. sibirica, showed significant inhibitory effects on 12-O-tetradecanoylphorbol
13-acetate (TPA)-induced cyclooxygenase-2 (COX-2) expression in immortalized
human breast epithelial MCF10A cells.
PMID- 10784441
TI - Carrier-envelope phase control of femtosecond mode-locked lasers and direct
optical frequency synthesis
AB - We stabilized the carrier-envelope phase of the pulses emitted by a femtosecond
mode-locked laser by using the powerful tools of frequency-domain laser
stabilization. We confirmed control of the pulse-to-pulse carrier-envelope phase
using temporal cross correlation. This phase stabilization locks the absolute
frequencies emitted by the laser, which we used to perform absolute optical
frequency measurements that were directly referenced to a stable microwave clock.
PMID- 10784443
TI - Windows through the dusty disks surrounding the youngest low-mass protostellar
objects.
AB - The formation and evolution of young low-mass stars are characterized by
important processes of mass loss and accretion occurring in the innermost regions
of their placentary circumstellar disks. Because of the large obscuration of
these disks at optical and infrared wavelengths in the early protostellar stages
(class 0 sources), they were previously detected only at radio wavelengths using
interferometric techniques. We have detected with the Infrared Space Observatory
the mid-infrared (mid-IR) emission associated with the class 0 protostar VLA1 in
the HH1-HH2 region located in the Orion nebula. The emission arises in three
wavelength windows (at 5. 3, 6.6, and 7.5 micrometers) where the absorption due
to ices and silicates has a local minimum that exposes the central part of the
young protostellar system to mid-IR investigations. The mid-IR emission arises
from a central source with a diameter of 4 astronomical units at an averaged
temperature of approximately 700 K, deeply embedded in a dense region with a
visual extinction of 80 to 100 magnitudes.
PMID- 10784444
TI - Control of energy transfer in oriented conjugated polymer-mesoporous silica
composites
AB - Nanoscale architecture was used to control energy transfer in semiconducting
polymers embedded in the channels of oriented, hexagonal nanoporous silica.
Polarized femtosecond spectroscopies show that excitations migrate
unidirectionally from aggregated, randomly oriented polymer segments outside the
pores to isolated, aligned polymer chains within the pores. Energy migration
along the conjugated polymer backbone occurred more slowly than Forster energy
transfer between polymer chains. The different intrachain and interchain energy
transfer time scales explain the behavior of conjugated polymers in a range of
solution environments. The results provide insights for optimizing nanostructured
materials for use in optoelectronic devices.
PMID- 10784442
TI - Architecture of RNA polymerase II and implications for the transcription
mechanism.
AB - A backbone model of a 10-subunit yeast RNA polymerase II has been derived from x
ray diffraction data extending to 3 angstroms resolution. All 10 subunits exhibit
a high degree of identity with the corresponding human proteins, and 9 of the 10
subunits are conserved among the three eukaryotic RNA polymerases I, II, and III.
Notable features of the model include a pair of jaws, formed by subunits Rpb1,
Rpb5, and Rpb9, that appear to grip DNA downstream of the active center. A clamp
on the DNA nearer the active center, formed by Rpb1, Rpb2, and Rpb6, may be
locked in the closed position by RNA, accounting for the great stability of
transcribing complexes. A pore in the protein complex beneath the active center
may allow entry of substrates for polymerization and exit of the transcript
during proofreading and passage through pause sites in the DNA.
PMID- 10784445
TI - A superconducting field-effect switch.
AB - We report here on a novel realization of a field-effect device that allows
switching between insulating and superconducting states, which is the widest
possible variation of electrical properties of a material. We chose C(60) as the
active material because of its low surface state density and observed
superconductivity in alkali metal-doped C(60). We induced three electrons per
C(60) molecule in the topmost molecular layer of a crystal with the field-effect
device, creating a superconducting switch operating up to 11 kelvin. An insulator
was thereby transformed into a superconductor. This technique offers new
opportunities for the study of superconductivity as a function of carrier
concentration.
PMID- 10784446
TI - The Archean sulfur cycle and the early history of atmospheric oxygen.
AB - The isotope record of sedimentary sulfides can help resolve the history of oxygen
accumulation into the atmosphere. We measured sulfur isotopic fractionation
during microbial sulfate reduction up to 88 degrees C and show how sulfate
reduction rate influences the preservation of biological fractionations in
sediments. The sedimentary sulfur isotope record suggests low concentrations of
seawater sulfate and atmospheric oxygen in the early Archean (3.4 to 2.8 billion
years ago). The accumulation of oxygen and sulfate began later, in the early
Proterozoic (2.5 to 0.54 billion years ago).
PMID- 10784447
TI - Heightened odds of large earthquakes near istanbul: An interaction-based
probability calculation
AB - We calculate the probability of strong shaking in Istanbul, an urban center of 10
million people, from the description of earthquakes on the North Anatolian fault
system in the Marmara Sea during the past 500 years and test the resulting
catalog against the frequency of damage in Istanbul during the preceding
millennium. Departing from current practice, we include the time-dependent effect
of stress transferred by the 1999 moment magnitude M = 7.4 Izmit earthquake to
faults nearer to Istanbul. We find a 62 +/- 15% probability (one standard
deviation) of strong shaking during the next 30 years and 32 +/- 12% during the
next decade.
PMID- 10784448
TI - Extension of cell life-span and telomere length in animals cloned from senescent
somatic cells.
AB - The potential of cloning depends in part on whether the procedure can reverse
cellular aging and restore somatic cells to a phenotypically youthful state.
Here, we report the birth of six healthy cloned calves derived from populations
of senescent donor somatic cells. Nuclear transfer extended the replicative life
span of senescent cells (zero to four population doublings remaining) to greater
than 90 population doublings. Early population doubling level complementary DNA-1
(EPC-1, an age-dependent gene) expression in cells from the cloned animals was
3.5- to 5-fold higher than that in cells from age-matched (5 to 10 months old)
controls. Southern blot and flow cytometric analyses indicated that the telomeres
were also extended beyond those of newborn (<2 weeks old) and age-matched control
animals. The ability to regenerate animals and cells may have important
implications for medicine and the study of mammalian aging.
PMID- 10784449
TI - Gene therapy of human severe combined immunodeficiency (SCID)-X1 disease.
AB - Severe combined immunodeficiency-X1 (SCID-X1) is an X-linked inherited disorder
characterized by an early block in T and natural killer (NK) lymphocyte
differentiation. This block is caused by mutations of the gene encoding the
gammac cytokine receptor subunit of interleukin-2, -4, -7, -9, and -15 receptors,
which participates in the delivery of growth, survival, and differentiation
signals to early lymphoid progenitors. After preclinical studies, a gene therapy
trial for SCID-X1 was initiated, based on the use of complementary DNA containing
a defective gammac Moloney retrovirus-derived vector and ex vivo infection of
CD34+ cells. After a 10-month follow-up period, gammac transgene-expressing T and
NK cells were detected in two patients. T, B, and NK cell counts and function,
including antigen-specific responses, were comparable to those of age-matched
controls. Thus, gene therapy was able to provide full correction of disease
phenotype and, hence, clinical benefit.
PMID- 10784450
TI - Localization of a short-term memory in Drosophila.
AB - Memories are thought to be due to lasting synaptic modifications in the brain.
The search for memory traces has relied predominantly on determining regions that
are necessary for the process. However, a more informative approach is to define
the smallest sufficient set of brain structures. The rutabaga adenylyl cyclase,
an enzyme that is ubiquitously expressed in the Drosophila brain and that
mediates synaptic plasticity, is needed exclusively in the Kenyon cells of the
mushroom bodies for a component of olfactory short-term memory. This demonstrates
that synaptic plasticity in a small brain region can be sufficient for memory
formation.
PMID- 10784451
TI - Control of homeostasis of CD8+ memory T cells by opposing cytokines.
AB - Memory T cells maintain their numbers for long periods after antigen exposure.
Here we show that CD8+ T cells of memory phenotype divide slowly in animals. This
division requires interleukin-15 and is markedly increased by inhibition of
interleukin-2 (IL-2). Therefore, the numbers of CD8+ memory T cells in animals
are controlled by a balance between IL-15 and IL-2.
PMID- 10784452
TI - Location of a major susceptibility locus for familial schizophrenia on chromosome
1q21-q22.
AB - Schizophrenia is a complex disorder, and there is substantial evidence supporting
a genetic etiology. Despite this, prior attempts to localize susceptibility loci
have produced predominantly suggestive findings. A genome-wide scan for
schizophrenia susceptibility loci in 22 extended families with high rates of
schizophrenia provided highly significant evidence of linkage to chromosome 1
(1q21-q22), with a maximum heterogeneity logarithm of the likelihood of linkage
(lod) score of 6.50. This linkage result should provide sufficient power to allow
the positional cloning of the underlying susceptibility gene.
PMID- 10784453
TI - Resetting central and peripheral circadian oscillators in transgenic rats.
AB - In multicellular organisms, circadian oscillators are organized into multitissue
systems which function as biological clocks that regulate the activities of the
organism in relation to environmental cycles and provide an internal temporal
framework. To investigate the organization of a mammalian circadian system, we
constructed a transgenic rat line in which luciferase is rhythmically expressed
under the control of the mouse Per1 promoter. Light emission from cultured
suprachiasmatic nuclei (SCN) of these rats was invariably and robustly rhythmic
and persisted for up to 32 days in vitro. Liver, lung, and skeletal muscle also
expressed circadian rhythms, which damped after two to seven cycles in vitro. In
response to advances and delays of the environmental light cycle, the circadian
rhythm of light emission from the SCN shifted more rapidly than did the rhythm of
locomotor behavior or the rhythms in peripheral tissues. We hypothesize that a
self-sustained circadian pacemaker in the SCN entrains circadian oscillators in
the periphery to maintain adaptive phase control, which is temporarily lost
following large, abrupt shifts in the environmental light cycle.
PMID- 10784455
TI - Dementia in the twenty-first century.
PMID- 10784456
TI - Quality of life in individuals with anxiety disorders.
AB - OBJECTIVE: Quality-of-life indices have been used in medical practice to estimate
the impact of different diseases on functioning and well-being and to compare
outcomes between different treatment modalities. An integrated view of the issue
of quality of life in patients with anxiety disorders can provide important
information regarding the nature and extent of the burden associated with these
disorders and may be useful in the development of strategies to deal with it.
METHOD: A review of epidemiological and clinical studies that have investigated
quality of life (broadly conceptualized) in patients with panic disorder, social
phobia, posttraumatic stress disorder, generalized anxiety disorder, and
obsessive-compulsive disorder was conducted by searching MEDLINE and PsycLIT
citations from 1984 to 1999. A summary of the key articles published in this area
is presented. RESULTS: The studies reviewed portray an almost uniform picture of
anxiety disorders as illnesses that markedly compromise quality of life and
psychosocial functioning. Significant impairment can also be found in individuals
with subthreshold forms of anxiety disorders. Effective pharmacological or
psychotherapeutic treatment has been shown to improve the quality of life for
patients with panic disorder, social phobia, and posttraumatic stress disorder.
Limitations in current knowledge in this area are identified, and suggestions for
needed future research are provided. CONCLUSIONS: It is expected that a more
thorough understanding of the impact on quality of life will lead to increased
public awareness of anxiety disorders as serious mental disorders worthy of
further investment in research, prevention, and treatment.
PMID- 10784457
TI - Cytokines and the brain: implications for clinical psychiatry.
AB - OBJECTIVE: This article reviews recent developments in cytokine biology that are
relevant to clinical psychiatry. METHOD: The authors reviewed English-language
literature of the last 15 years that pertains to the biology of cytokines with
emphasis on central nervous system effects in general and psychiatric disorders
in particular. RESULTS: Growing evidence suggests that, in addition to providing
communication between immune cells, specific cytokines play a role in signaling
the brain to produce neurochemical, neuroendocrine, neuroimmune, and behavioral
changes. This signaling may be part of a generalized, comprehensive mechanism to
mobilize resources in the face of physical and/or psychological stress and to
maintain homeostasis. The clinical implications of these findings are far
reaching and include a possible role for cytokines in the pathophysiology of
specific psychiatric disorders such as major depression, schizophrenia, and
Alzheimer's disease. The effects of cytokines in the central nervous system may
provide a possible mechanism for the "sickness behavior" of patients with severe
infection or cancer, as well as for the neuropsychiatric adverse effects of
treatment with interferons and interleukins. CONCLUSIONS: A better understanding
of the role of cytokines in various brain activities will enhance knowledge of
specific psychobiological mechanisms in health and disease and provide
opportunities for novel treatment interventions.
PMID- 10784458
TI - Cognition: mental rotation.
PMID- 10784459
TI - Tug-of-war: domestic abuse and the misuse of religion.
PMID- 10784461
TI - Dementia in elderly persons in a general hospital.
AB - OBJECTIVE: This study investigated the prevalence of dementia in a general
hospital, reasons for which patients with dementia were admitted, and the
relationship between dementia and length of stay, cost, and in-hospital mortality
rate. METHOD: The study focused on data from the hospital database on 21,251
patients aged 60 and older who were discharged in 1996 and 1997. Patients were
grouped as with or without a discharge diagnosis of dementia by ICD-9-CM
criteria. The groups were compared on sociodemographic characteristics, principal
discharge diagnoses, lengths of stay, costs, and in-hospital mortality rates.
RESULTS: The prevalence of dementia among discharged patients was 3.9% (N=823);
it was dependent on age (age 60-64, prevalence=2.6%; age 85 and older,
prevalence=8.9%). The primary discharge diagnoses of the groups were different.
The mean length of stay was 10.4 days for patients with dementia and 6.5 days for
patients without dementia. Per capita hospital costs were $4,000 higher for
patients with dementia. Differences in lengths of stay and per capita costs were
statistically significant after adjusting for age, race, and sex. Lengths of stay
and hospital costs for patients with dementia were significantly higher for eight
primary discharge diagnoses after adjusting for age, race, and sex. CONCLUSIONS:
Dementia is present in a significant proportion of patients admitted to general
inpatient units. Patients with dementia are admitted for different reasons than
patients without dementia and appear to have longer stays, which are associated
with higher costs. Efforts to identify dementia early during hospitalization
could improve patient care and reduce costs.
PMID- 10784462
TI - Mental and behavioral disturbances in dementia: findings from the Cache County
Study on Memory in Aging.
AB - OBJECTIVE: The authors report findings from a study of 5,092 community residents
who constituted 90% of the elderly resident population of Cache County, Utah.
METHOD: The 5,092 participants, who were 65 years old or older, were screened for
dementia. Based on the results of this screen, 1,002 participants (329 with
dementia and 673 without dementia) underwent comprehensive neuropsychiatric
examinations and were rated on the Neuropsychiatric Inventory, a widely used
method for ascertainment and classification of dementia-associated mental and
behavioral disturbances. RESULTS: Of the 329 participants with dementia, 214
(65%) had Alzheimer's disease, 62 (19%) had vascular dementia, and 53 (16%) had
another DSM-IV dementia diagnosis; 201 (61%) had exhibited one or more mental or
behavioral disturbances in the past month. Apathy (27%), depression (24%), and
agitation/aggression (24%) were the most common in participants with dementia.
These disturbances were almost four times more common in participants with
dementia than in those without. Only modest differences were observed in the
prevalence of mental or behavioral disturbances in different types of dementia or
at different stages of illness: participants with Alzheimer's disease were more
likely to have delusions and less likely to have depression. Agitation/aggression
and aberrant motor behavior were more common in participants with advanced
dementia. CONCLUSIONS: On the basis of their findings in this large community
population of elderly people, the authors conclude that a wide range of dementia
associated mental and behavioral disturbances afflict the majority of individuals
with dementia. Because of their frequency and their adverse effects on patients
and their caregivers, these disturbances should be ascertained and treated in all
cases of dementia.
PMID- 10784463
TI - Vitamin B(12) deficiency and depression in physically disabled older women:
epidemiologic evidence from the Women's Health and Aging Study.
AB - OBJECTIVE: It has been hypothesized that adequate concentrations of vitamin B(12)
and folate are essential to maintain the integrity of the neurological systems
involved in mood regulation, but epidemiologic evidence for such a link in the
general population is unavailable. This study examined whether community-dwelling
older women with metabolically significant vitamin B(12) or folate deficiency are
particularly prone to depression. METHOD: Serum levels of vitamin B(12), folate,
methylmalonic acid, and total homocysteine were assayed in 700 disabled,
nondemented women aged 65 years and over living in the community. Depressive
symptoms were measured by means of the Geriatric Depression Scale and categorized
as no depression, mild depression, and severe depression. RESULTS: Serum
homocysteine levels, serum folate levels, and the prevalences of folate
deficiency and anemia were not associated with depression status. The depressed
subjects, especially those with severe depression, had a significantly higher
serum methylmalonic acid level and a nonsignificantly lower serum vitamin B(12)
level than the nondepressed subjects. Metabolically significant vitamin B(12)
deficiency was present in 14.9% of the 478 nondepressed subjects, 17. 0% of the
100 mildly depressed subjects, and 27.0% of the 122 severely depressed women.
After adjustment for sociodemographic characteristics and health status, the
subjects with vitamin B(12) deficiency were 2.05 times as likely to be severely
depressed as were nondeficient subjects. CONCLUSIONS: In community-dwelling older
women, metabolically significant vitamin B(12)deficiency is associated with a
twofold risk of severe depression.
PMID- 10784464
TI - Comorbid anxiety disorders in depressed elderly patients.
AB - OBJECTIVE: Anxiety disorders are common in adults with depressive disorders, but
several studies have suggested a relatively low prevalence of anxiety disorders
in older individuals with depression. This cross-sectional study measured current
and lifetime rates and associated clinical features of anxiety disorders in
depressed elderly patients. METHOD: History of anxiety disorders was assessed by
using a structured diagnostic instrument in 182 depressed subjects aged 60 and
older seen in primary care and psychiatric settings. Associations between
comorbid anxiety disorders and baseline characteristics were measured. The
modified structured instrument allowed detection of symptoms that met inclusion
criteria for generalized anxiety disorder in a depressive episode. RESULTS:
Thirty-five percent of older subjects with depressive disorders had at least one
lifetime anxiety disorder diagnosis, and 23% had a current diagnosis. The most
common current comorbid anxiety disorders were panic disorder (9.3%), specific
phobias (8.8%), and social phobia (6.6%). Symptoms that met inclusion criteria
for generalized anxiety disorder, measured separately, were present in 27.5% of
depressed subjects. Presence of a comorbid anxiety disorder was associated with
poorer social function and a higher level of somatic symptoms. Symptoms of
generalized anxiety disorder were associated with a higher level of suicidality.
CONCLUSIONS: Contrary to previous reports, the present study found a relatively
high rate of current and lifetime anxiety disorders in elderly depressed
individuals. Comorbid anxiety disorders and symptoms of generalized anxiety
disorder were associated with a more severe presentation of depressive illness in
elderly subjects.
PMID- 10784465
TI - Comparison of sertraline and nortriptyline in the treatment of major depressive
disorder in late life.
AB - OBJECTIVE: This study was designed to evaluate the comparative efficacy and
safety of sertraline and nortriptyline for the treatment of major depressive
disorder in older adults. METHOD: A double-blind, parallel group design was used
to compare 210 outpatients, 60 years of age and older, who met DSM-III-R criteria
for major depressive episode and had a minimum Hamilton Depression Rating Scale
score of 18. The patients were randomly assigned to 12 weeks of treatment with
either sertraline (50-150 mg/day) or nortriptyline (25-100 mg/day). RESULTS: The
safety profiles of the two treatments were similar except that nortriptyline
treatment was associated with a significant increase in pulse rate, whereas
sertraline was associated with a nonsignificant decrease. Efficacy of both drugs
was similar for both treatments at all time points, with 71.6% (N=53 of 74) of
the sertraline-treated patients and 61.4% (N=43 of 70) of the nortriptyline
treated patients achieving responder status by week 12. Time to response was also
similar, with more than 75% of the improvement in scores on the Hamilton
depression scale having occurred by week 6. Secondary efficacy measures
(posttreatment measures of cognitive function, memory, and quality of life)
revealed a significant advantage for sertraline treatment. CONCLUSIONS: Primary
efficacy measures showed sertraline and nortriptyline to be similarly effective.
With secondary outcome measures there was consistent evidence of an advantage for
the sertraline-treated group. The clinical impact of these measures on the long
term well-being of elderly depressed patients should be examined in a study of
maintenance treatment.
PMID- 10784467
TI - Age at first alcohol use: a risk factor for the development of alcohol disorders.
AB - OBJECTIVE: This study aimed to describe the natural course of DSM-III-R alcohol
disorders as a function of age at first alcohol use and to investigate the
influence of early use as a risk factor for progression to the development of
alcohol disorders, exclusive of the effect of confounding influences. METHOD:
Data were obtained from a community sample (N=5,856) of lifetime drinkers
participating in the 1990-1991 Mental Health Supplement of the Ontario Health
Survey. RESULTS: Survival analyses revealed a rapid progression to alcohol
related harm among those who reported having their first drink at ages 11-14.
After 10 years, 13.5% of the subjects who began to drink at ages 11 and 12 met
the criteria for a diagnosis of alcohol abuse, and 15.9% had a diagnosis of
dependence. Rates for subjects who began to drink at ages 13 and 14 were 13.7%
and 9.0%, respectively. In contrast, rates for those who started drinking at ages
19 and older were 2.0% and 1.0%. Unexpectedly, a delay in progression to harm was
observed for the youngest drinkers (ages 10 and under). Hazard regression
analyses revealed a nonlinear effect of age at first alcohol use, marked by an
elevated risk of developing disorders among subjects first using alcohol at ages
11-14. CONCLUSIONS: First use of alcohol at ages 11-14 greatly heightens the risk
of progression to the development of alcohol disorders and therefore is a
reasonable target for intervention strategies that seek to delay first use as a
means of averting problems later in life.
PMID- 10784466
TI - Hippocampal volume in adolescent-onset alcohol use disorders.
AB - OBJECTIVE: Alcohol use disorders (defined as DSM-IV alcohol dependence or abuse)
are prevalent and serious problems among adolescents. As adolescence is marked by
progressive hippocampal development, this brain region may be particularly
susceptible to the adverse effects of adolescent alcohol use disorders. This
study compared the hippocampal volumes of adolescents and young adults with
adolescent-onset alcohol use disorders to those of healthy matched comparison
subjects. METHOD: Magnetic resonance imaging was used to measure the hippocampal
volumes and volumes of comparison brain regions in 12 subjects with alcohol use
disorders and 24 comparison subjects matched on age, sex, and handedness.
RESULTS: Both left and right hippocampal volumes were significantly smaller in
subjects with alcohol use disorders than in comparison subjects. Total
hippocampal volume correlated positively with the age at onset and negatively
with the duration of the alcohol use disorder. Intracranial, cerebral, and
cortical gray and white matter volumes and measures of the mid-sagittal area of
the corpus callosum did not differ between groups. CONCLUSIONS: In the mature
brain, chronic alcohol use disorders are associated with graded global brain
dysmorphology. Although the etiology, neuropsychological consequences, and
permanence of these hippocampal findings need to be further examined, these
findings suggest that, during adolescence, the hippocampus may be particularly
susceptible to the adverse effects of alcohol.
PMID- 10784468
TI - Prospective study of depression and the risk of heavy alcohol use in women.
AB - OBJECTIVE: The authors' goal was to determine whether depression is associated
with a greater risk of heavy alcohol consumption in women. METHOD: The study was
based on a 1-year follow-up of the Baltimore cohort of the National Institute of
Mental Health Epidemiologic Catchment Area project. The sample consisted of 1,383
women at risk for heavy alcohol use. History of depression and frequency of
lifetime-experienced depressive symptoms were assessed at baseline, and incident
cases of heavy drinking were identified 1 year later. After calculating
descriptive statistics for the sample, the authors developed a series of logistic
regression models to estimate the risk of heavy drinking at follow-up associated
with depression status. RESULTS: The initial estimate of the risk for heavy
drinking in women with a history of depressive disorder was 2.60 times greater
than the risk in women with no history of depressive disorder. This estimate did
not change markedly after adjustment for age, history of antisocial personality
disorder, or father's history of heavy drinking (relative risk=2.2). A higher
frequency of depressive symptoms was also found to be associated with an
elevation in the risk for heavy alcohol use (relative risk=1.09). CONCLUSIONS:
These results add to other evidence that depression must be considered in the
assessment of vulnerability for heavy alcohol use in women. Further research is
needed to clarify the mechanisms of the observed association and to discover
whether detection and effective treatment of depression might reduce risk of
later alcohol problems.
PMID- 10784469
TI - Central auditory processing in patients with auditory hallucinations.
AB - OBJECTIVE: Data from a full assessment of auditory perception in patients with
schizophrenia were used to investigate whether auditory hallucinations are
associated with abnormality of central auditory processing. METHOD: Three groups
of subjects participated in auditory assessments: 22 patients with psychosis and
a recent history of auditory hallucinations, 16 patients with psychosis but no
history of auditory hallucinations, and 22 normal subjects. Nine auditory
assessments, including auditory brainstem response, monotic and dichotic speech
perception tests, and nonspeech perceptual tests, were performed. Statistical
analyses for group differences were performed using analysis of variance and
Kruskal-Wallis tests. The results of individual patients with test scores in the
severely abnormal range (more than three standard deviations from the mean for
the normal subjects) were examined for patterns that suggested sites of
dysfunction in the central auditory system. RESULTS: The results showed
significant individual variability among the subjects in both patient groups.
There were no group differences on tests that are sensitive to low brainstem
function. Both patient groups performed poorly in tests that are sensitive to
cortical or high brainstem function, and hallucinating patients differed from
nonhallucinating patients in scores on tests of filtered speech perception and
response bias patterns on dichotic speech tests. Six patients in the
hallucinating group had scores in the severely abnormal range on more than one
test. CONCLUSIONS: Hallucinations may be associated with auditory dysfunction in
the right hemisphere or in the interhemispheric pathways. However, comparison of
results for the patient groups suggests that the deficits seen in hallucinating
patients may represent a greater degree of the same types of deficits seen in
nonhallucinating patients.
PMID- 10784470
TI - Normal P50 suppression in schizophrenia patients treated with atypical
antipsychotic medications.
AB - OBJECTIVE: Patients with schizophrenia have deficits in attention, cognition, and
information processing. Measures such as P50 suppression are used to study
cognitive and attentional dysfunction among these patients. P50 suppression is an
operational measure of sensory gating that can be assessed by averaging
electroencephalographic responses to multiple pairs of auditory clicks separated
by 500 msec. Normally, the P50 response to the second click is smaller than the
response to the first click. Many studies have demonstrated that schizophrenia
patients have deficient P50 suppression, meaning that the difference between the
first and second clicks is not as large as normal. Atypical antipsychotic
medications may have superior clinical efficacy for negative symptoms and
cognitive deficits. It is important, therefore, to evaluate the effects of
atypical antipsychotic medications on measures such as P50 suppression. METHOD:
P50 suppression of 13 patients with schizophrenia receiving clinically effective
doses of clozapine, olanzapine, or risperidone (classified as atypical
antipsychotic medications) was compared to that of 13 patients receiving
conventional antipsychotic medications. RESULTS: The patient groups did not
differ on clinical or demographic measures. The patients receiving atypical
antipsychotic medications had normal-range P50 suppression (mean=72%). In
contrast, the patients receiving typical antipsychotic medications had
dramatically lower P50 suppression (mean=27%). CONCLUSIONS: The results support
the hypothesis that patients treated with atypical antipsychotic medications have
normal P50 measures of sensory gating. Longitudinal within-subjects studies are
warranted to clarify the mechanisms mediating this effect.
PMID- 10784471
TI - Continuous performance test and schizophrenia: a test of stimulus-response
compatibility, working memory, response readiness, or none of the above?
AB - OBJECTIVE: Abnormalities of attention are considered the fundamental deficits in
cognitive function manifested by patients with schizophrenia. The authors
administered variations of two types of cognitive tasks to patients with
schizophrenia (N=20) and normal comparison subjects (N=30) to test four possible
cognitive mechanisms that might account for such abnormalities. METHOD:
Variations of the Continuous Performance Test were used to test the four
mechanisms. Stimulus-response mapping was explored by comparing results on a task
in which subjects were to make a response if the word "nine" was preceded by the
word "one" with results on a task in which the required response was made
explicit by the stimulus (the word "ready" followed by the word "press"). The
building up of a prepotent response tendency was tested by manipulating the
probability with which the cue and imperative stimulus appeared (17% or 50%). The
amount of working memory required to maintain contextual information was tested
by using different delay intervals (1000 msec and 3000 msec). The extent to which
problems in vigilance might be attributable to problems in the "motoric"
component of response readiness was operationalized by having subjects perform a
secondary motor task concurrent with the attentional task. RESULTS: Patients with
schizophrenia performed significantly worse than the normal comparison subjects
on all tasks. However, none of the four manipulations of the Continuous
Performance Test tasks had a differential impact on the patients' performance
speed or accuracy. In contrast, there was a significant interaction of group,
delay interval, and target probability in which patients made disproportionately
more omission errors at short delay intervals and at low target probabilities.
CONCLUSIONS: The findings may call into question the explanatory power of certain
well-known contemporary mechanistic accounts of performance on the Continuous
Performance Test in patients with schizophrenia. The findings suggest that a
difficulty in rapidly encoding information (i.e., constructing a representation)
in certain "unengaging" situations may be at the core of deficits on tasks
associated with this attentional test.
PMID- 10784472
TI - Visual perception and working memory in schizotypal personality disorder.
AB - OBJECTIVE: Patients affected by schizophrenia show deficits in both visual
perception and working memory. The authors tested early-stage vision and working
memory in subjects with schizotypal personality disorder, which has been
biologically associated with schizophrenia. METHOD: Eleven subjects who met DSM
III-R criteria for schizotypal personality disorder and 12 normal comparison
subjects were evaluated. Performance thresholds were obtained for tests of visual
discrimination and working memory. Both form and trajectory processing were
evaluated for each task. RESULTS: Subjects with schizotypal personality disorder
showed intact discrimination of form and trajectory but were impaired on working
memory tasks. CONCLUSIONS: These data suggest that subjects with schizotypal
personality disorder, unlike patients affected by schizophrenia, have relatively
intact visual perception. Subjects with schizotypal personality disorder do show
specific deficits on tasks of comparable difficulty when working memory demands
are imposed. Schizotypal personality disorder may be associated with a more
specific visual processing deficit than schizophrenia, possibly reflecting
disruption of frontal lobe systems subserving visual working memory operations.
PMID- 10784473
TI - Verbal and nonverbal neuropsychological test performance in subjects with
schizotypal personality disorder.
AB - OBJECTIVE: The authors contrasted verbal and nonverbal measures of attention and
memory in patients with DSM-IV-defined schizotypal personality disorder in order
to expand on their previous findings of verbal learning deficits in these
patients and to understand better the neuropsychological profile of schizotypal
personality disorder. METHOD: Cognitive test performance was examined in 16 right
handed men who met diagnostic criteria for schizotypal personality disorder and
16 matched male comparison subjects. Neuropsychological measures included verbal
and nonverbal tests of persistence, supraspan learning, and short- and long-term
memory retention. Neuropsychological profiles were constructed by standardizing
test scores based on the means and standard deviations of the comparison subject
group. RESULTS: Subjects with schizotypal personality disorder showed a mild to
moderate general reduction in performance on all measures. Verbal measures of
persistence, short-term retention, and learning were more severely impaired than
their nonverbal analogs. Performance on measures of memory retention was
independent of modality. CONCLUSIONS: The results are consistent with previous
reports that have suggested a mild, general decrement in cognitive performance
and proportionately greater involvement of the left hemisphere in patients with
schizotypal personality disorder. The findings provide further support for a
specific deficit in the early processing stages of verbal learning.
PMID- 10784474
TI - Premorbid speech and language impairments in childhood-onset schizophrenia:
association with risk factors.
AB - OBJECTIVE: As both premorbid neurodevelopmental impairments and familial risk
factors for schizophrenia are prominent in childhood-onset cases (with onset of
psychosis by age 12), their relationship was examined. METHOD: Premorbid
language, motor, and social impairments were assessed in a cohort of 49 patients
with childhood-onset schizophrenia. Familial loading for schizophrenia spectrum
disorders, familial eye-tracking dysfunction, and obstetrical complications were
assessed without knowledge of premorbid abnormalities and were compared in the
patients with and without developmental impairments. RESULTS: Over one-half of
the patients in this group had developmental dysfunction in each domain assessed.
The patients with premorbid speech and language impairments had higher familial
loading scores for schizophrenia spectrum disorders and more obstetrical
complications, and their relatives had worse smooth-pursuit eye movements. The
boys had more premorbid motor abnormalities, but early language and social
impairments did not differ significantly between genders. There were no other
significant relationships between premorbid social or motor abnormalities and the
risk factors assessed here. CONCLUSIONS: Premorbid developmental impairments are
common in childhood-onset schizophrenia. The rates of three risk factors for
schizophrenia (familial loading for schizophrenia spectrum disorders, familial
eye-tracking dysfunction, and obstetrical complications) were increased for the
probands with premorbid speech and language impairments, suggesting that the
pathophysiology of schizophrenia involves the abnormal development of language
related brain regions.
PMID- 10784475
TI - Obstetric risk factors for early-onset schizophrenia in a Finnish birth cohort.
AB - OBJECTIVE: Although case-control investigations have shown an association between
obstetric complications and schizophrenia, particularly among patients with early
onsets, cohort studies have mostly failed to confirm this effect. The authors
examined whether a history of fetal hypoxia and other obstetric complications
elevated risk for early-onset schizophrenia in a 1955 Helsinki birth cohort.
METHOD: The subjects were 80 randomly selected patients with schizophrenia (36
with early and 44 with later onsets) representative of all available probands in
the cohort, 61 of their nonschizophrenic siblings, and 56 demographically matched
nonpsychiatric comparison subjects. Psychiatric diagnoses were obtained from
structured clinical interviews, and obstetric data were taken from standardized,
prospectively ascertained obstetric records. A score for hypoxia-associated
obstetric complications was entered into logistic regression models, along with
measures of prenatal infection and fetal growth retardation. RESULTS: Hypoxia
associated obstetric complications significantly increased the odds of early
onset schizophrenia but not of later-onset schizophrenia or unaffected sibling
status, after prenatal infection and fetal growth retardation were taken into
account. CONCLUSIONS: These findings support an association between obstetric
complications and increased risk for early-onset schizophrenia. The authors
advance a model whereby the neurotoxic effects of fetal hypoxia may lead to an
early onset of schizophrenia due to premature cortical synaptic pruning.
PMID- 10784476
TI - Untreated initial psychosis: its relation to quality of life and symptom
remission in first-episode schizophrenia.
AB - OBJECTIVE: Previous studies have suggested that there may be an association
between longer duration of untreated psychosis and poor outcome in schizophrenia.
These studies have been interpreted as providing evidence that untreated
psychosis may constitute an "active morbid process" that is "toxic" to the brain.
If untreated psychosis is neurotoxic, this would form a strong basis for early
intervention in schizophrenia. METHOD: Seventy-four neuroleptic-naive patients
with DSM-IV schizophrenia were evaluated 6 months after their first inpatient
hospitalization. The authors examined the relationship between untreated initial
psychosis duration (measured from onset of first symptom as well as from onset of
full positive syndrome) and quality of life, symptom severity, and time to
remission of positive symptoms. RESULTS: Earlier age at illness onset was
associated with longer duration of untreated prodromal psychotic symptoms. There
were no significant gender differences in duration of untreated initial
psychosis, nor were there any significant associations between untreated initial
psychosis duration and premorbid functioning. After controlling for the effects
of age at onset, the duration of untreated initial psychosis did not
significantly impair subsequent quality of life, symptom severity, or remission
of positive symptoms. CONCLUSIONS: Duration of untreated initial psychosis was
not prognostic of poor outcome early in the course of schizophrenia. Biological
measures of neurotoxicity are needed to examine the "toxic psychosis" hypothesis
more directly.
PMID- 10784477
TI - Age-dependent decline of symptoms of attention deficit hyperactivity disorder:
impact of remission definition and symptom type.
AB - OBJECTIVE: Symptom decline in attention deficit hyperactivity disorder (ADHD) was
examined with different definitions of remission. METHOD: Symptoms in 128 boys
were measured five times over 4 years. The prevalences of syndromatic (less than
full syndrome), symptomatic (less than subthreshold diagnosis), and functional
(full recovery) remission were estimated as a function of age with multivariate
logistic regression. RESULTS: Age was significantly associated with decline in
total ADHD symptoms and symptoms of hyperactivity, impulsivity, and inattention.
Symptoms of inattention remitted for fewer subjects than did symptoms of
hyperactivity or impulsivity. The proportion of subjects experiencing remission
varied considerably with the definition used (highest for syndromatic remission,
lowest for functional remission). CONCLUSIONS: These results indicate that
differences in reported remission rates reflect the definition used rather than
the disorder's course. They provide systematic support for the clinical
observation that hyperactivity and impulsivity symptoms tend to decline at a
higher rate than inattention symptoms.
PMID- 10784478
TI - Divalproex treatment for youth with explosive temper and mood lability: a double
blind, placebo-controlled crossover design.
AB - OBJECTIVE: The authors sought to replicate open-label findings showing that
specific criteria for explosive temper and mood lability identify disruptive
youth who improve while receiving the anticonvulsant divalproex sodium. METHOD:
Twenty outpatient children and adolescents (ages 10-18) with a disruptive
behavior disorder (oppositional defiant disorder or conduct disorder) met the
specific criteria for explosive temper and mood lability. They received 6 weeks
of divalproex treatment and 6 weeks of placebo by random assignment. Independent
evaluators blind to group assignment assessed response at the end of each phase.
RESULTS: At the end of phase 1, eight of 10 subjects had responded to divalproex;
zero of 10 had responded to placebo. Of the 15 subjects who completed both
phases, 12 has superior response taking divalproex. CONCLUSIONS: This preliminary
study replicates open-label findings showing that divalproex is an efficacious
treatment for explosive temper and mood lability in disruptive children and
adolescents.
PMID- 10784479
TI - Response to flumazenil in women with premenstrual dysphoric disorder.
AB - OBJECTIVE: The authors sought to determine whether the administration of
flumazenil would induce marked panic symptoms in women suffering from
premenstrual dysphoric disorder. METHOD: Ten women with premenstrual dysphoric
disorder and 11 comparison subjects were injected with flumazenil or placebo in a
double-blind, randomized, balanced crossover design in a single session in the
luteal phase of their menstrual cycles. RESULTS: Flumazenil induced a much
greater panic response in the women with premenstrual dysphoric disorder than in
the comparison subjects. CONCLUSIONS: These preliminary results are consistent
with a dysregulation of the g-aminobutyric acid A/benzodiazepine receptor complex
during the premenstruum of women suffering from premenstrual dysphoric disorder.
PMID- 10784480
TI - Adhesio interthalamica in male patients with schizophrenia.
AB - OBJECTIVE: The authors investigated whether absence of the adhesio interthalamica
in patients with schizophrenia constitutes a marker of early developmental
neuropathological changes. METHOD: Thirty male patients with schizophrenia and 30
healthy male subjects were recruited for study. Magnetic resonance imaging was
performed, and the presence or absence of the adhesio interthalamica was
determined for each subject. The length and volume of the third ventricle were
also measured. RESULTS: No differences in the presence or absence of the adhesio
interthalamica were found between patients with schizophrenia and normal
comparison subjects. Patients without the adhesio interthalamica had
significantly higher scores for negative symptoms than patients with the adhesio
interthalamica. There was no correlation between absence of the adhesio
interthalamica and length and volume of the third ventricle in either patients or
comparison subjects. CONCLUSIONS: The findings suggest that patients with
schizophrenia who do not have the adhesio interthalamica are characterized by
more severe negative symptoms.
PMID- 10784481
TI - Placebo-controlled trial of glycine added to clozapine in schizophrenia.
AB - OBJECTIVE: The purpose of this study was to evaluate the effects of high-dose
oral glycine on positive and negative symptoms and cognitive function when added
to clozapine in adults with schizophrenia. METHOD: The authors conducted a double
blind, placebo-controlled, parallel-group trial of 60 g/day of glycine added to
clozapine for 8 weeks in 30 adults with schizophrenia. Clinical ratings were
performed every 2 weeks. RESULTS: Twenty-seven patients completed the trial.
Glycine augmentation of clozapine produced no statistically significant change in
positive or negative symptoms or cognitive functioning. No subjects showed
clinically significant worsening of clinical ratings. CONCLUSIONS: These data,
combined with data from previous trials with D-cycloserine and glycine, suggest
that agonists at the glycine site may be less effective when combined with
clozapine than they are when combined with conventional antipsychotics.
PMID- 10784482
TI - Reduced olfactory bulb volume in patients with schizophrenia.
AB - OBJECTIVE: The authors' goal in this study was to compare the size of olfactory
bulbs of patients with schizophrenia and those of healthy subjects. METHOD:
Magnetic resonance imaging scans of olfactory bulbs were obtained from 26
patients with schizophrenia and 22 healthy comparison subjects. A reliable region
of interest procedure was used to measure olfactory bulb volume. RESULTS:
Patients exhibited 23% smaller bilateral bulb volume than comparison subjects,
independent of acute clinical, demographic, or treatment measures. Bulb volume
correlated with odor detection sensitivity in healthy subjects but not in
patients with schizophrenia. CONCLUSIONS: Patients with schizophrenia exhibit
structural olfactory deficits as well as functional olfactory deficits. The
olfactory system may be a model system in which to study the neurobiology of the
disorder.
PMID- 10784484
TI - Amphetamine misuse and social phobia.
PMID- 10784483
TI - Low GSK-3beta immunoreactivity in postmortem frontal cortex of schizophrenic
patients.
AB - OBJECTIVE: Glycogen synthase kinase-3 (GSK-3) is a protein kinase that is highly
abundant in the brain. It is involved in signal transduction cascades of multiple
cellular processes, particularly neurodevelopment. In an attempt to explore
possible involvement of GSK-3beta in psychiatric disorders, the authors examined
its levels in postmortem brain tissue. METHOD: Western blot analysis was
performed to measure GSK-3beta in the frontal cortex of 14 schizophrenic
patients, 15 patients with bipolar disorder, 15 patients with unipolar
depression, and 14 normal comparison subjects. RESULTS: GSK-3beta levels were 41%
lower in the schizophrenic patients than in the comparison subjects. Other
diagnostic groups did not differ from the comparison subjects. CONCLUSIONS: These
results are consistent with the notion that schizophrenia involves
neurodevelopmental pathology. It remains to be investigated whether the active
fraction of GSK-3beta, or its activity, is also low in frontal cortex of
schizophrenic patients and if this is also reflected in other brain regions.
PMID- 10784485
TI - Focal segmental glomerulosclerosis and lithium treatment.
PMID- 10784486
TI - Euphoric mania and rapid transcranial magnetic stimulation.
PMID- 10784487
TI - Ziprasidone overdose.
PMID- 10784488
TI - Antidepressant-induced sexual dysfunction and Ginkgo Biloba.
PMID- 10784489
TI - Racial differences in treatment of adolescents with bipolar disorder.
PMID- 10784490
TI - Mnemonic screening device for generalized anxiety disorder.
PMID- 10784491
TI - Treatments to change sexual orientation.
PMID- 10784493
TI - Biology versus psychoanalysis.
PMID- 10784494
TI - Possible interaction of tramadol and antidepressants.
PMID- 10784500
TI - Cross-Cultural Practice: Assessment, Treatment, and Training.
PMID- 10784496
TI - Use of ECT in Italy.
PMID- 10784503
TI - Psychoanalysis: Clinical and Theoretical.
PMID- 10784508
TI - Unusual and memorable
PMID- 10784507
TI - Inflammation-mediated rheumatic diseases and atherosclerosis.
PMID- 10784510
TI - Rheumatic diseases and the environment
PMID- 10784512
TI - Biology of the synovial joint
PMID- 10784513
TI - Factors that modify the association between knee pain and mobility limitation in
older women: the Women's Health and Aging Study.
AB - OBJECTIVE: To investigate the influence of pain severity, knee extensor muscle
weakness, obesity, depression, and activity on the association between recent
knee pain and limitation of usual and fast paced walking, and ability to rise
from a chair. METHODS: A cross sectional analysis of 769 older women (mean age
77.8, range 65-101) with physical disability, but no severe cognitive impairment.
Severity of knee pain in the past month was classified as none, moderate, or
severe. Mobility was measured using timed performance tests. RESULTS: The
prevalence of recent knee pain was 53% (408/769). One third of the women with
pain reported it to be severe. In general, knee pain was only significantly
associated with limited mobility if severe. Obesity, activity and, to a lesser
extent, depression intensified the effects of pain. Knee extensor weakness did
not. Obesity was a distinctive risk factor in that it substantially increased the
risk of mobility limitation, but only in women with pain. In women who had severe
pain, activity (walking more than three city blocks in the past week) increased
the risk of walking disability more than inactivity. Depression had a minor, but
statistically significant effect on walking ability, but not the ability to rise
from a chair. CONCLUSION: In older women with recent knee pain, a high pain
severity score, obesity, and activity are important factors that increase the
risk of mobility limitation.
PMID- 10784514
TI - The oxidative metabolism of circulating phagocytes in ankylosing spondylitis:
determination by whole blood chemiluminescence.
AB - OBJECTIVE: Superoxide anion radicals within the human body are regarded as a
major cause of inflammation. However, their role in the pathogenesis of
ankylosing spondylitis (AS) has not been well identified. This study aimed at
investigating the relation between AS and the oxidative metabolism of phagocytes
in whole blood. METHODS: 24 patients with classic AS were examined to determine
their clinical status; complete blood count, erythrocyte sedimentation rate
(ESR), and C reactive protein (CRP) were determined, and levels of the superoxide
anion radicals in the patients with AS and 21 healthy subjects were assessed by
the ultraweak chemiluminescence method. Subsequently, the relation between this
disease and phagocytes was examined by using N-formyl-methionyl-leucyl
phenylalanine (fMLP) and phorbol-12-myristate-13-acetate (PMA) stimulants.
RESULTS: In clinical assessments, patients with AS had abnormally raised serum
CRP (>10 mg/l) and ESR (>15 mm/1st h) levels. In contrast with healthy subjects,
patients with AS had significantly increased rates of superoxide anion radical
production in their whole blood either in the resting state or with either fMLP
or PMA stimulation. In addition, chemiluminescence maximum light intensity was
significantly higher in patients with AS than in healthy subjects after fMLP or
PMA stimulation. CONCLUSIONS: Our results suggest that the phagocytes of patients
with AS are partly activated in the resting state, and are sensitive to fMLP or
PMA stimulation. The priming of phagocytes in the bloodstream is likely to be a
causative factor in the onset of AS.
PMID- 10784515
TI - Detection of multiple viral DNA species in synovial tissue and fluid of patients
with early arthritis.
AB - OBJECTIVE: Viruses have a role in the pathogenesis of various forms of arthritis.
This study aimed at determining whether viral DNA can be detected in joint
samples in the early stages of idiopathic arthritides. METHODS: Synovial fluid
(SF) and synovial tissue (ST) samples were obtained from 73 patients, with
undifferentiated arthritis (n=22), rheumatoid arthritis (n=13),
spondyloarthropathy (n=17), crystal arthropathy (n=8), osteoarthritis (n=7),
septic arthritis (n=5), and trauma (n=1). The presence of viral DNA was
investigated by polymerase chain reaction analysis. RESULTS: Cytomegalovirus was
present in 25 patients, parvovirus B19 in 15 patients, Epstein-Barr virus in 12
patients, and herpes simplex virus in 16 patients (in ST, SF, or both),
respectively. The joint samples were negative for viral DNA from adenovirus and
varicella-zoster virus. In ST, eight patients were double positive for parvovirus
B19 and another viral DNA, with herpes simplex virus being the most prevalent.
Seven patients were double positive for other viruses (cytomegalovirus, herpes
simplex virus, Epstein-Barr virus). In SF, four patients were double or triple
positive for viral DNA. Paired samples were available in 56 patients. In these,
viral DNA was detected in 37 patients in ST, as compared with 19 in SF.
CONCLUSION: These data show that one or more viruses can be detected in the
synovial specimens of patients with early arthritis, irrespective of the clinical
diagnosis. This observation might be explained by migration of inflammatory cells
harbouring viral DNA into the inflamed joints.
PMID- 10784516
TI - Percentage of glycosylated serum ferritin remains low throughout the course of
adult onset Still's disease.
AB - OBJECTIVE: To determine the evolution of levels of total serum ferritin and
percentage of the glycosylated form in patients with adult onset Still's disease
(AOSD) at the time of diagnosis and during follow up. METHODS: All patients with
AOSD were tested at the time of diagnosis and during follow up. Total serum
ferritin levels were analysed by immunoassay, and the percentage of glycosylated
ferritin was determined by methods using Sepharose-Con A. RESULTS: 14 patients
(eight women, six men) with AOSD were enrolled. At the time of diagnosis, mean
(SD) age was 36 (16) years. Mean initial total serum ferritin was 6350 (1300)
microg/l (normal <250 microg/l). The mean initial percentage of glycosylated
ferritin was 14.7 (13)% (normal >50%). Mean follow up time was 37 (35) months. At
the time of the last examination all patients were in remission except one, who
presented a chronic articular form. Total serum ferritin remained high in this
single patient and was normal in the 13 others, with a mean of 98 (73) microg/l.
In all patients the percentage of glycosylated ferritin remained low, with a mean
of 16 (16)%. CONCLUSION: Total serum ferritin is a marker of the active phase of
AOSD. The percentage of glycosylated ferritin is low both in the active phase and
in remission. Further studies are needed to confirm these data and to determine
their specificity for AOSD before considering any possible use of a low
percentage of glycosylated ferritin as a diagnostic tool in suspected AOSD,
especially when atypical or previously treated.
PMID- 10784517
TI - Effect of circulating immune complexes on the binding of rheumatoid factor to
histones.
AB - OBJECTIVE: To determine whether the reaction of rheumatoid factor (RF) with solid
phase histone is due to the simultaneous presence of circulating immune complexes
(CICs) or aggregated IgG. METHODS: Serum samples from 56 patients with
seropositive rheumatoid arthritis (RA) and 50 random blood bank donors were used.
Binding of immunoglobulins to histone was determined by enzyme linked
immunosorbent assay (ELISA) and by western blots. Aggregated IgG was obtained by
heating at 61(o)C for 30 minutes. RESULTS: Among the RA sera tested by ELISA, 54%
were positive for histone binding by IgM, IgG, or IgA and 20% by IgM only.
Heating of normal sera caused a significant enhancement in the binding of IgG to
histone (p<0.001). This binding had a non-cognate behaviour-that is, it was
destroyed by pepsin treatment of serum and was not significantly inhibited by
competition with free histone. The same behaviour was seen for IgM, IgG, and IgA
binding from RA sera. However, cognate IgG antibody binding to histone was
inhibited by free histone and was resistant to pepsin digestion. Addition of heat
aggregated IgG to RA sera or pretreatment of histone with aggregated IgG caused a
significant increase in IgM binding to histone. CONCLUSION: IgM, IgG, and IgA RF
bind to solid phase histone as a result of attachment to histone of immune
complexes or aggregated IgG and not as a result of a cognate reaction with
histone.
PMID- 10784518
TI - Systemic scleroderma in Greece: low mortality and strong linkage with HLA
DRB1*1104 allele.
AB - OBJECTIVE: Description of Greek patients with scleroderma with reference to (a)
major organ disease, (b) autoantibodies, (c) survival rate, and (d) HLA
associations. METHODS: The clinical files of 254 patients were analysed
retrospectively and a standardised clinical chart was completed with age at
disease onset, sex, date of first and last visit, clinical and serological
findings, organs affected, reasons for death, and HLA class II alleles. HLA class
II alleles (DRB1, DQA1, DQB1, DPB1) were determined by polymerase chain reaction
amplification using oligopeptide probes. DNA was extracted from 98 patients and
130 Greek controls. RESULTS: 124 patients (49%) had limited systemic sclerosis
(lSSc), 114 (45%) had diffuse systemic sclerosis (dSSc), and 16 (6%) had overlap
syndromes. Patients with dSSc, compared with lSSc, were characterised by a higher
prevalence of lung disease (p=0.0011), oesophageal, heart, and peripheral vessel
disease (p=0.027, p=0.0025, and p=0.012, respectively). Anticentromere antibodies
(ACA) occurred exclusively in lSSc (34%), whereas antibodies to topoisomerase I
(anti-topo I) were associated with dSSc (p<0.0001). Anti-topo I were associated
with interstitial pulmonary fibrosis, oesophageal and peripheral vessel disease
(p=0.028, p=0.012, and p=0.01, respectively). The HLA-DRB1*1104 allele was
associated with the disease (p<0.0001) and anti-topo I (p<0.001), whereas it was
not associated with ACA serum reactivity (p<0.001). Renal disease occurred in 4%
of patients with SSc. The estimated survival probability for this cohort of
patients with SSc, four years after the first visit, is 94.8%. CONCLUSION: SSc
among Greek subjects has the same pattern of organ disease as in other white
populations. However, the prevalence of kidney disease is low. The HLA class II
DRB1*1104 allele is associated with the disease, with anti-topo I, and not
associated with ACA serum reactivity.
PMID- 10784519
TI - Does location of vertebral deformity within the spine influence back pain and
disability? European Vertebral Osteoporosis Study (EVOS) Group.
AB - OBJECTIVE: Vertebral deformity is associated with back pain and disability. The
aim of this analysis was to determine whether location within the spine
influences the strength of association between vertebral deformity, back pain and
disability. METHODS: Men and women aged 50 years and over were recruited from
population registers in 30 European centres. Subjects were invited for an
interviewer administered questionnaire, and for lateral spinal radiographs. The
questionnaire included questions about back pain, general health and functional
ability. The spinal radiographs were evaluated morphometrically and vertebral
deformity defined according to the McCloskey-Kanis method. RESULTS: 756 (11.7%)
men and 885 (11. 8%) women had evidence of one or more vertebral deformities.
Among women with a single deformity, after adjusting for age and centre, those
with a lumbar deformity were more likely than those with a thoracic deformity to
report back pain, both currently (OR=1.4; 95% CI 1.0, 2.0) and in the past year
(OR=1.5; 95% CI 1.0, 2.3). No association was observed in men. Among women with
two deformities, those with adjacent deformities were more likely than those with
non-adjacent deformities to report poor general health (OR=2.2; 95%CI 0.9, 5.6),
impaired functional ability (OR=1.9; 95%CI 0.8, 4. 7) and current back pain
(OR=2.1; 95%CI 0.9, 4.9), though none of these associations were statistically
significant. By contrast, among men, non-adjacent deformities were associated
with impaired functional ability compared with those with adjacent deformities.
CONCLUSION: Location within the spine influences the strength of association
between self reported health factors and vertebral deformity.
PMID- 10784520
TI - Pneumomediastinum in dermatomyositis: association with cutaneous vasculopathy.
AB - OBJECTIVES: To study the pathogenesis of pneumomediastinum in
polymyositis/dermatomyositis (PM/DM). PATIENTS AND METHODS: The clinical records
of 48 patients with PM/DM were reviewed, focusing mainly on the presence of
pneumomediastinum and cutaneous vasculopathy, and the chest radiographic changes.
A patient with pneumomediastinum with a characteristic change in his bronchus is
described in detail. Case reports of pneumomediastinum in PM/DM in English
publications are reviewed. RESULTS: Among the 48 patients with PM/DM,
pneumomediastinum was observed as a complication in four patients with DM and
none of the patients with PM. Three of the four patients with pneumomediastinum,
but only six of the 44 patients without this complication, had associated
cutaneous vasculopathy. There was a significant association of pneumomediastinum
with cutaneous vasculopathy (p = 0.02) and younger age (p = 0.04), but not with
the prevalence of lung disease. A 30 year old man (patient 1) with DM, who had
interstitial pneumonitis and skin ulceration due to vasculopathy, developed
pneumomediastinum. Fibreoptic bronchoscopy showed white plaques on the bronchial
mucosa, which were confirmed by microscopic examination as representing
subepithelial necrosis. A literature review showed 13 cases of DM but no patient
with PM with pneumomediastinum. CONCLUSIONS: In patient 1, bronchial necrosis due
to vasculopathy was strongly suspected as being responsible for the
pneumomediastinum. The results suggest that pneumomediastinum was associated not
with interstitial pneumonitis but with the complication of vasculopathy appearing
as skin lesions in DM.
PMID- 10784522
TI - Microsatellite analysis in rheumatoid arthritis synovial fibroblasts.
AB - OBJECTIVES: Rheumatoid arthritis (RA) is a chronic disease characterised by
irreversible destruction of the affected joints. As aggressive transformed
appearing synovial fibroblasts are commonly found at the site of invasion of the
rheumatoid synovium into the adjacent cartilage and bone, the presence of
microsatellite instability (MSI) and expression of mismatch repair enzymes as a
possible mechanism in the alteration of these cells was examined. METHODS: DNA
was extracted from the synovial fibroblasts and blood of 20 patients with long
term RA undergoing joint replacement, and the presence of MSI was studied at 10
microsatellite loci. In addition, immunohistochemistry was performed to evaluate
the expression of the two major mismatch repair enzymes (hMLH1 and hMSH2) in
rheumatoid synovium. RESULTS: MSI could not be detected in any of the fibroblast
cell populations derived from the 20 different rheumatoid synovial samples. In
addition, strong expression of mismatch repair enzymes could be seen in numerous
cells, including fibroblasts, throughout the synovium. CONCLUSIONS: Applying the
currently used and established markers for MSI, the data show for the first time
that MSI does not appear to have an important role in alteration of rheumatoid
synovial fibroblasts into an aggressive phenotype. On the other hand, strong
mismatch repair enzyme synthesis in rheumatoid synovium supports the hypothesis
of continuing DNA repair, presumably due to long term, inflammation induced DNA
damage.
PMID- 10784521
TI - Diagnosis and monitoring of central nervous system involvement in systemic lupus
erythematosus: value of F-18 fluorodeoxyglucose PET.
AB - OBJECTIVE: To investigate prospectively abnormalities of brain glucose
utilisation in relation to major or minor neuropsychiatric symptoms in systemic
lupus erythematosus (SLE). METHODS: Positron emission tomography (PET) using F-18
labelled fluorodeoxyglucose was performed in 28 patients with SLE. Patients were
classified as having severe neuropsychiatric manifestations (seizures, focal
neurological deficits, acute confusional states, mood disorders) (n=12), or mild
neuropsychiatric manifestations (headache, reactive depression, cognitive
dysfunction, anxiety disorders) (n=11) and five patients without signs of central
nervous system (CNS) involvement. Ten clinically and neurologically healthy
volunteers served as controls. In 26 patients magnetic resonance imaging (MRI)
was performed and autoantibodies against CNS tissue, ribosomal P protein and
cardiolipin were measured. In 14 patients follow up PET scans were performed
after a mean (SD) period of 11.6 (9.5) months. RESULTS: PET scans showed
hypometabolism in at least one brain region in all patients with severe or mild
CNS symptoms (100%) as compared with patients without cerebral symptoms (40%)
(p<0.0025). Parieto-occipital regions were most commonly affected (96%), followed
by parietal regions (32%). In contrast, MRI images were abnormal in only 11 of 22
patients (50%) with neuropsychiatric symptoms and in one of four patients (25%)
without symptoms. In 12 of 14 patients examined in follow up PET scans
persistence, improvement or worsening of cerebral symptoms were associated with
unchanged, decreased or increased brain hypometabolism, respectively. No
significant correlation was found between PET or MRI findings and autoantibody
profiles. CONCLUSIONS: PET imaging represents a sensitive tool to detect manifest
or subclinical CNS involvement in SLE and PET findings correlate well with the
clinical course of disease.
PMID- 10784523
TI - Systemic vasculitis with bilateral perirenal haemorrhage in chronic
myelomonocytic leukaemia.
AB - The cases of two patients with chronic myelomonocytic leukaemia associated with
periarteritis nodosa-like, antineutrophil cytoplasmic antibody negative, systemic
vasculitis, are reported. A 61 year old man was admitted with fever, diffuse
myalgia, and abdominal pain. Blood and bone marrow examination showed chronic
myelomonocytic leukaemia. Vasculitis of the gall bladder was responsible for
acalculous cholecystitis. A massive spontaneous bilateral perirenal haemorrhage
occurred. A 73 year old woman with chronic myelomonocytic leukaemia had been
followed up for one year when unexplained fever occurred. Two months after the
onset of fever, sudden abdominal pain was ascribed to spontaneous bilateral renal
haematoma related to bilateral renal arterial aneurysms. Neuromuscular biopsy
showed non-necrotising periarteriolar inflammation. To our knowledge, systemic
vasculitis has never been reported in chronic myelomonocytic leukaemia. In our
two cases a non-random association is suggested because (a) chronic
myelomonocytic leukaemia is a rare myelodysplastic syndrome, (b) spontaneous
bilateral perirenal haematoma is not a usual feature of periarteritis nodosa.
PMID- 10784524
TI - Do not resuscitate decisions: flogging dead horses or a dignified death?
Resuscitation should not be withheld from elderly people without discussion.
PMID- 10784525
TI - Valuing the effects of sildenafil in erectile dysfunction. Strong assumptions are
required to generate a QALY value.
PMID- 10784526
TI - Multicentre research ethics committees: has the cure been worse than the disease?
No, but idiosyncracies and obstructions to good research must be removed.
PMID- 10784528
TI - Reducing the speed limit to 20 mph in urban areas. Child deaths and injuries
would be decreased.
PMID- 10784527
TI - Risk of torsades de pointes with non-cardiac drugs. Doctors need to be aware that
many drugs can cause qt prolongation.
PMID- 10784529
TI - Control malaria to help defeat poverty, says WHO.
PMID- 10784530
TI - NHS should be recast in BBC mould, says report.
PMID- 10784531
TI - Spain launches national plan for palliative care.
PMID- 10784533
TI - In brief
PMID- 10784532
TI - Health insurer delays psychiatric admissions.
PMID- 10784534
TI - National register will monitor hip replacements.
PMID- 10784535
TI - Discrimination "rife" against mental health patients.
PMID- 10784536
TI - Guru promotes global health.
PMID- 10784537
TI - Cost utility analysis of sildenafil compared with papaverine-phentolamine
injections.
AB - OBJECTIVE: To compare the cost effectiveness of sildenafil and papaverine
phentolamine injections for treating erectile dysfunction. DESIGN: Cost utility
analysis comparing treatment with sildenafil (allowing a switch to injection
therapy) and treatment with papaverine-phentolamine (no switch allowed). Costs
and effects were estimated from the societal perspective. Using time trade-off, a
sample of the general public (n=169) valued health states relating to erectile
dysfunction. These values were used to estimated health related quality of life
by converting the clinical outcomes of a trial into quality adjusted life years
(QALYs). PARTICIPANTS: 169 residents of Rotterdam. MAIN OUTCOME MEASURES: Cost
per quality adjusted life year. RESULTS: Participants thought that erectile
dysfunction limits quality of life considerably: the mean utility gain
attributable to sildenafil is 0.11. Overall, treatment with sildenafil gained
more QALYs, but the total costs were higher. The incremental cost effectiveness
ratio for the introduction of sildenafil was pound sterling 3639 in the first
year and fell in following years. Doubling the frequency of use of sildenafil
almost doubled the cost per additional QALY. CONCLUSIONS: Treatment with
sildenafil is cost effective. When considering funding sildenafil, healthcare
systems should take into account that the frequency of use affects cost
effectiveness.
PMID- 10784538
TI - Scientific, ethical, and logistical considerations in introducing a new
operation: a retrospective cohort study from paediatric cardiac surgery.
AB - OBJECTIVE: To review the initial impact on mortality of infants with congenital
heart disease of a new surgical technique that is now taken for granted. DESIGN:
Retrospective cohort study. SETTING: A tertiary paediatric cardiology centre.
SUBJECTS: 325 consecutive neonates with simple transposition of the great
arteries admitted before, during, and after the preferred management changed from
the Senning operation to the arterial switch (1978-98); and 100 consecutive
neonates requiring a different neonatal open heart operation that did not change
in that period. MAIN OUTCOME MEASURES: Mortality before and early after operation
reconstructed sequentially as the series evolved and retrospectively once the
series was complete; actuarial survival associated with the different treatment
strategies. RESULTS: For both the transposition and the comparison group, early
mortality in 1998 was lower than in 1978. During that period, however, there was
a phase temporally related to the adoption of the switch operation in which early
mortality for transposition increased. Actuarial survival of recent patients with
"intention to treat" with arterial switch is superior to those with intention to
treat with the Senning operation, as predicted when the switch operation was
first adopted. CONCLUSIONS: A period of increased hazard for individual patients
may occur when a specialist community, a particular unit, and an individual
surgeon are all learning a new technique concurrently. Obtaining informed consent
during this time of uncertainty is helped by clarity about the objectives of
treatment and availability of relevant local and international data.
PMID- 10784540
TI - The odd man out
PMID- 10784539
TI - Temperature measured at the axilla compared with rectum in children and young
people: systematic review.
AB - OBJECTIVE: To evaluate the agreement between temperature measured at the axilla
and rectum in children and young people. DESIGN: A systematic review of studies
comparing temperature measured at the axilla (test site) with temperature
measured at the rectum (reference site) using the same type of measuring device
at both sites in each patient. Devices were mercury or electronic thermometers or
indwelling thermocouple probes. STUDIES REVIEWED: 40 studies including 5528
children and young people from birth to 18 years. DATA EXTRACTION: Difference in
temperature readings at the axilla and rectum. RESULTS: 20 studies (n=3201 (58%)
participants) had sufficient data to be included in a meta-analysis. There was
significant residual heterogeneity in both mean differences and sample standard
deviations within the groups using different devices and within age groups. The
pooled (random effects) mean temperature difference (rectal minus axillary
temperature) for mercury thermometers was 0.25 degrees C (95% limits of agreement
-0.15 degrees C to 0.65 degrees C) and for electronic thermometers was 0. 85
degrees C (-0.19 degrees C to 1.90 degrees C). The pooled (random effects) mean
temperature difference (rectal minus axillary temperature) for neonates was 0.17
degrees C (-0.15 degrees C to 0. 50 degrees C) and for older children and young
people was 0.92 degrees C (-0.15 degrees C to 1.98 degrees C). CONCLUSIONS: The
difference between temperature readings at the axilla and rectum using either
mercury or electronic thermometers showed wide variation across studies. This has
implications for clinical situations where temperature needs to be measured with
precision.
PMID- 10784541
TI - The new system of review by multicentre research ethics committees: prospective
study.
AB - OBJECTIVE: To assess the function of the new system of review by multicentre
research ethics committees and to highlight areas where improvement is still
needed. DESIGN: Prospectively collected data from a multicentre study was
examined with respect to the ethics review process. Administrative, financial,
and time elements of the review process were audited. SETTING: A single
multicentre research ethics committee and 125 local ethics committees from six
regions of England. MAIN OUTCOME MEASURES: Time to reply, time to approval, and
number of non-local changes to the application requested. RESULTS: Only 40% of
local ethics committees considered our study in the manner specified in the 1998
directive. Less than a third of committees replied within the 21 day period
stipulated, although committees acting by executive subcommittee replied more
quickly than those not acting by executive subcommittee. There was a tendency for
executive subcommittees to approve studies in a shorter time. Local ethics
committees asked for a large number of non-local changes to the application. The
financial cost of applying to multiple ethics committees remains high, mainly
because multiple copies of research applications are being requested.
CONCLUSIONS: The new system of approval by multicentre research ethics committee
for multicentre studies was introduced to reduce administrative costs, speed up
the process of reviews by multiple research ethics committees, and standardise
the conclusions of the local research ethics committees. Since its introduction
an improvement has been seen, but the system is not yet universally functioning
as intended. Ethics review still remains a hindrance to the financial resources
and commencement of national studies. We strongly support the structure of review
by multicentre research ethics committees but suggest that the system has yet to
achieve its aims.
PMID- 10784543
TI - The cost of getting approval
PMID- 10784542
TI - Responses of local research ethics committees to a study with approval from a
multicentre research ethics committee.
PMID- 10784545
TI - Keep looking for a reason
PMID- 10784544
TI - Sedation with "non-sedating" antihistamines: four prescription-event monitoring
studies in general practice.
AB - OBJECTIVES: To investigate the frequency with which sedation was reported in post
marketing surveillance studies of four second generation antihistamines:
loratadine, cetirizine, fexofenadine, and acrivastine. DESIGN: Prescription-event
monitoring studies. SETTING: Prescriptions were obtained for each cohort in the
immediate post-marketing period. SUBJECTS: Event data were obtained for a total
of 43 363 patients. MAIN OUTCOME MEASURES: Reporting of sedation or drowsiness.
RESULTS: The odds ratios (adjusted for age and sex) for the incidence of sedation
were 0.63 (95% confidence interval 0.36 to 1.11; P=0.1) for fexofenadine; 2.79
(1.69 to 4.58; P<0.0001) for acrivastine, and 3.53 (2.07 to 5.42; P<0.0001) for
cetirizine compared with loratadine. No increased risk of accident or injury was
evident with any of the four drugs. CONCLUSIONS: Although the risk of sedation
was low with all four drugs, fexofenadine and loratadine may be more appropriate
for people working in safety critical jobs.
PMID- 10784546
TI - Drug treatment in heart failure.
PMID- 10784547
TI - Email submissions from outside the united kingdom
PMID- 10784548
TI - ABC of arterial and venous disease. Arterial aneurysms.
PMID- 10784549
TI - "Shouldn't we do something about the fire?"
PMID- 10784550
TI - How should cost data in pragmatic randomised trials be analysed?
PMID- 10784552
TI - Fifty five years later
PMID- 10784551
TI - Income inequality and mortality: importance to health of individual income,
psychosocial environment, or material conditions.
PMID- 10784553
TI - A good death. Sharing control in death: the role of an "amicus mortis".
PMID- 10784554
TI - Older Americans hold on to life dearly.
PMID- 10784555
TI - New models of journals must be sought.
PMID- 10784556
TI - Population, consumption, and entrapment. Raise living standards to reduce
population growth.
PMID- 10784557
TI - Eradicating war is essential to eliminate poverty and improve health.
PMID- 10784558
TI - Will eradication of Helicobacter pylori improve symptoms of non-ulcer dyspepsia?
Studies included in meta-analysis had heterogenous, not homogenous, results.
PMID- 10784559
TI - Use of unlabelled and off licence drugs in children. Use of unlicensed drugs may
be recommended in guidelines.
PMID- 10784560
TI - Prescriptions on bioterrorism have it backwards.
PMID- 10784561
TI - Pathogen causing infection related to body piercing should be determined.
PMID- 10784562
TI - Patient information systems are not more expensive than leaflets.
PMID- 10784564
TI - Obituaries
PMID- 10784563
TI - Joint Committee on Postgraduate Training for GPs needs more money for its work.
PMID- 10784566
TI - Evidence based gastroenterology and hepatology
PMID- 10784565
TI - Consultants' leaders spell out NHS spending priorities
PMID- 10784567
TI - Bioethics: An anthology
PMID- 10784568
TI - Humanitarian crises: the medical and public health response
PMID- 10784569
TI - Blue/Orange
PMID- 10784571
TI - The class reunion
PMID- 10784570
TI - The ethics of research ethics committees.
PMID- 10784572
TI - Ebrahim's quartet
PMID- 10784574
TI - New operations bring period of increased hazard for patients
PMID- 10784573
TI - Healthcare systems should fund sildenafil
PMID- 10784575
TI - Temperature measured at the axilla in children and young people may be misleading
PMID- 10784576
TI - Ethics approval for multicentre research is expensive, slow, and inconsistent
PMID- 10784577
TI - Non-sedating antihistamines have differing sedative effects
PMID- 10784578
TI - Material conditions directly affect health inequalities, not income inequality
PMID- 10784579
TI - Follow the money.
PMID- 10784580
TI - Helicobacter heilmannii-associated primary gastric low-grade MALT lymphoma:
complete remission after curing the infection.
AB - BACKGROUND & AIMS: Cure of Helicobacter pylori infection may lead to complete
remission of associated low-grade mucosa-associated lymphoid tissue (MALT)
lymphoma in stage EI. This study investigated whether Helicobacter heilmannii
infection-associated primary gastric MALT lymphoma will regress after cure of the
infection. METHODS: H. heilmannii-induced gastritis was diagnosed histologically,
by a new specific immunoglobulin G enzyme-linked immunosorbent assay, and with
16S ribosomal RNA amplification and sequencing in 5 consecutive patients with
primary gastric MALT lymphoma clinical stage EI. Patients received 40 mg
omeprazole and 750 mg amoxicillin 3 times per day for 14 days. Polymerase chain
reaction (PCR) was used to detect rearrangement of immunoglobulin heavy-chain
genes before treatment and during follow-up. RESULTS: Five patients (3 men, 2
women; mean age, 65 years; range, 42-79 years) were studied. H. pylori was not
detected by culture, histology, serology, or PCR. Treatment resulted in the cure
of H. heilmannii infection in each case and complete histological and endoscopic
remission of the tumors. Three of 5 patients showed monoclonal B cells before
treatment, 2 of whom remained PCR positive. Within a median follow-up period of
24 months, no relapse of the lymphoma or reinfection with H. heilmannii occurred.
CONCLUSIONS: These data suggest that gastric MALT lymphoma may arise in patients
with H. heilmannii infection. Cure of this infection may lead to complete
remission of the MALT lymphoma.
PMID- 10784581
TI - Controlled 15-year trial on screening for colorectal cancer in families with
hereditary nonpolyposis colorectal cancer.
AB - BACKGROUND & AIMS: Identification of the hereditary nonpolyposis colorectal
cancer (HNPCC) syndrome enables prevention of colorectal cancer (CRC) by means of
colonoscopy and polypectomies. We evaluated the efficacy of screening in a
controlled trial over 15 years. METHODS: Incidence of CRC and survival were
compared in 2 cohorts of at-risk members of 22 families with HNPCC. Colonic
screening at 3-year intervals was arranged for 133 subjects; 119 control subjects
had no screening. Genetic testing was offered to subjects in whose families the
causative mutation was known. RESULTS: CRC developed in 8 screened subjects (6%)
compared with 19 control subjects (16 %; P = 0.014). The CRC rate was reduced by
62%. In mutation-positive subjects alone, the CRC rates were 18% in screened
subjects and 41% in controls (P = 0.02). The decrease resulted from the removal
of adenomas in 13 mutation-positive individuals (30%) and in 6 subjects with
unknown mutation status (40%). All CRCs in the study group were local, causing no
deaths, compared with 9 deaths caused by CRC in the controls. The overall death
rates were 10 vs. 26 subjects in the study and control groups (P = 0.003), 4 vs.
12 in mutation-positive subjects (P = 0.05). CONCLUSIONS: Colonoscopic screening
at 3-year intervals more than halves the risk of CRC, prevents CRC deaths, and
decreases overall mortality by about 65% in HNPCC families.
PMID- 10784582
TI - Microsatellite instability and mutation of mitochondrial and nuclear DNA in
gastric carcinoma.
AB - BACKGROUND & AIMS: Microsatellite instability (MSI) in mitochondrial DNA (mtDNA)
is observed in some colorectal carcinomas. We attempted to determine if
mitochondrial MSI (mtMSI) and mutations occur in gastric carcinomas and if the
mtMSI phenotype underlies specific clinicopathologic profiles. METHODS: Sixty-two
gastric carcinomas (34 intestinal and 28 diffuse types) were investigated. Coding
mutations in 8 different mitochondrial genes, mtMSI in a noncoding (C)n tract,
and p53 gene mutations were examined by polymerase chain reaction-single-strand
conformation polymorphism (PCR-SSCP) analysis. MSI in nuclear DNA (nMSI) and loss
of the p53 gene were examined using microsatellite markers. RESULTS: Ten of 62
(16%) carcinomas showed the mtMSI phenotype. Mitochondrial gene mutation was
detected in 5 carcinomas, 4 of which also showed the mtMSI phenotype. There was a
positive correlation between mtMSI and nMSI status. In intestinal carcinomas,
mtMSI, nMSI, and p53 gene alterations were frequently detected from early to
advanced stages. In diffuse carcinomas, both kinds of MSI were found in only
advanced (subserosal or serosal invasion) carcinomas. Six of 7 carcinomas with
the nMSI phenotype and all 5 carcinomas with mitochondrial coding mutations had a
considerable intestinal-type tumor cell component. CONCLUSIONS: Mitochondrial
gene mutations, which are associated with the mtMSI phenotype, may play a
specific role in the tumorigenesis of intestinal-type gastric carcinomas.
PMID- 10784583
TI - Regional cerebral activation in irritable bowel syndrome and control subjects
with painful and nonpainful rectal distention.
AB - BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is characterized by visceral
hypersensitivity, possibly related to abnormal brain-gut communication. Positron
emission tomography imaging has suggested specific central nervous system (CNS)
abnormalities in visceral pain processing in IBS. This study aimed to determine
(1) if functional magnetic resonance imaging (fMRI) detects CNS activity during
painful and nonpainful visceral stimulation; and (2) if CNS pain centers in IBS
respond abnormally. METHODS: fMRI was performed during nonpainful and painful
rectal distention in 18 patients with IBS and 16 controls. RESULTS: Rectal
stimulation increased the activity of anterior cingulate (33/34), prefrontal
(32/34), insular cortices (33/34), and thalamus (32/34) in most subjects. In IBS
subjects, but not controls, pain led to greater activation of the anterior
cingulate cortex (ACC) than did nonpainful stimuli. IBS patients had a greater
number of pixels activated in the ACC and reported greater intensity of pain at
55-mm Hg distention than controls. CONCLUSIONS: IBS patients activate the ACC, a
critical CNS pain center, to a greater extent than controls in response to a
painful rectal stimulus. Contrary to previous reports, these data suggest
heightened pain sensitivity of the brain-gut axis in IBS, with a normal pattern
of activation.
PMID- 10784584
TI - Distinct expression of splice variants of neuronal nitric oxide synthase in the
human gastrointestinal tract.
AB - BACKGROUND & AIMS: Changes of neuronal nitric oxide synthase (nNOS) expression
have been linked to several human gastrointestinal disorders such as achalasia,
diabetic gastroparesis, and hypertrophic pyloric stenosis. They could be caused
by differential transcriptional control or alternative splicing generating
different nNOS proteins. The aims of this study were to characterize 5'-splice
variants, promoter usage, and site-specific expression of nNOS in the human
gastrointestinal tract. METHODS: 5'-Splice variants were characterized by
immunoblotting, reverse-transcription polymerase chain reaction, 5'-rapid
amplification of complementary DNA ends, and Southern blotting. Genomic analysis
was performed by rapid amplification of genomic ends, followed by reporter gene
assays. RESULTS: Six different 5'-splice variants of nNOS-messenger RNA were
identified showing specific expressions at various sites of the human
gastrointestinal tract. Three variants encode for nNOSalpha, which has a specific
N-terminal PDZ/GLGF domain and interaction sites for regulatory proteins. Two
variants encode for nNOSbeta and 1 for nNOSgamma, which both lack the protein
binding domains of nNOSalpha. In addition to 2 known first exons, a novel first
exon of human nNOS with a separate functionally active downstream promoter and
multiple binding sites for transcription factors was identified and
characterized. CONCLUSIONS: Six 5'-mRNA splice variants of nNOS encoding 3
different nNOS proteins are expressed in the human gut. The differential
expression of these proteins could be implicated in different biological
functions.
PMID- 10784585
TI - Expression of glucocorticoid receptor beta in lymphocytes of patients with
glucocorticoid-resistant ulcerative colitis.
AB - BACKGROUND & AIMS: Recently, the glucocorticoid receptor beta (hGRbeta) was
suggested to play a role as a dominant negative regulator for determining
glucocorticoid response. The aim of this study was to clarify whether reverse
transcription polymerase chain reaction (RT-PCR) analysis of hGRbeta messenger
RNA (mRNA) can predict the response to glucocorticoids in patients with
ulcerative colitis. METHODS: Total RNA obtained from peripheral blood mononuclear
cells (PBMCs) of 23 patients with ulcerative colitis and 20 healthy volunteers
was reverse transcribed; the resulting complementary DNA was amplified using
specific primers for hGRalpha and hGRbeta. Protein expression of hGR in PBMCs was
confirmed by immunoprecipitation-Western blot analysis. RESULTS: The expression
of hGRalpha mRNA (477 base pairs) was detected in all patients and all healthy
volunteers. In contrast, a hGRbeta mRNA (366 base pairs) was detected in 1 (9.1%)
of 11 glucocorticoid-sensitive patients, 10 (83.3%) of 12 glucocorticoid
resistant patients, and 2 (10%) of 20 healthy volunteers. The positive rate of
hGRbeta mRNA in the resistant group was significantly higher than that in the
sensitive group (P = 0.0019). The hGRbeta band could be detected by
immunoprecipitation-Western blotting in hGRbeta mRNA-positive patients.
CONCLUSIONS: The results show that the expression of hGRbeta mRNA in PBMCs
examined by RT-PCR may serve as a novel predictor of glucocorticoid response in
ulcerative colitis.
PMID- 10784587
TI - Intestinal inflammation observed in IL-2R/IL-2 mutant mice is associated with
impaired intestinal T lymphopoiesis.
AB - BACKGROUND & AIMS: Although interleukin (IL)-2(-/-) and IL-2Ralpha(-/-) mice
develop inflammatory bowel disease, IL-2Rbeta(-/-) animals are apparently free of
gut pathology. Intraintestinal T lymphopoiesis is reported to be impaired in IL
2Rbeta(-/-) mice; we have determined whether this characteristic correlated with
the apparent resistance of this mutant strain to intestinal inflammation. This
led us to reassess intraintestinal T lymphopoiesis in these 3 mutant strains.
METHODS: Intestinal histology and intraintestinal T lymphopoiesis were analyzed
in unmanipulated mutant mice and in athymic and euthymic radiation chimeras
reconstituted with bone marrow derived from IL-2(-/-), IL-2Ralpha(-/-), and IL
2Rbeta(-/-) donors. RESULTS: Intraintestinal T lymphopoiesis was ablated in the 3
mutant strains and was associated with cryptopatch abnormalities. The intestinal
mucosa of mice reconstituted with lymphocytes from IL-2Rbeta(-/-) mice exhibited
lesions of both the small and large bowel similar to those observed in the early
stages of human gluten enteropathy and acute ulcerative colitis, respectively.
Analysis of euthymic and athymic bone marrow radiation chimeras indicated that T
cells located in the intestinal mucosa of unmanipulated IL-2(-/-), IL-2Ralpha(-/
), and IL-2Rbeta(-/-) mice are of thymic origin. CONCLUSIONS: Null mutations at
IL-2/IL-2Ralpha and beta loci differentially affect intraintestinal and
intrathymic T lymphopoiesis. These conditions are associated with lesions of
intestinal inflammation that are mediated by thymus-derived T cells.
PMID- 10784588
TI - Propagation and neural regulation of calcium waves in longitudinal and circular
muscle layers of guinea pig small intestine.
AB - BACKGROUND & AIMS: The relative movements of longitudinal muscle (LM) and
circular muscle (CM) and the role that nerves play in coordinating their
activities has been a subject of controversy. We used fluorescent video imaging
techniques to study the origin and propagation of excitability simultaneously in
LM and CM of the small intestine. METHODS: Opened segments of guinea pig ileum
were loaded with the Ca(2+) indicator fluo-3. Mucosal reflexes were elicited by
lightly depressing the mucosa with a sponge. RESULTS: Spontaneous Ca(2+) waves
occurred frequently in LM (1.2 s(-1)) and less frequently in CM (3.2 min(-1)).
They originated from discrete pacing sites and propagated at rates 8-9 times
faster parallel (LM, 87 mm/s; CM, 77 mm/s) compared with transverse to the long
axis of muscle fibers. The presence of Ca(2+) waves in one muscle layer did not
affect the origin, rate of conduction, or range of propagation in the other
layer. The extent of propagation was limited by collisions with neighboring waves
or recently excited regions. Simultaneous excitation of both muscle layers could
be elicited by mucosal stimulation of either ascending or descending reflex
pathways. Neural excitation resulted in an increase in the frequency of Ca(2+)
waves and induction of new pacing sites without eliciting direct coupling between
layers. CONCLUSIONS: Localized, spontaneous Ca(2+) waves occur independently in
both muscle layers, promoting mixing (pendular or segmental) movements, whereas
activation of neural reflexes stimulates Ca(2+) waves synchronously in both
layers, resulting in strong peristaltic or propulsive movements.
PMID- 10784586
TI - Selective expansion of intraepithelial lymphocytes expressing the HLA-E-specific
natural killer receptor CD94 in celiac disease.
AB - BACKGROUND & AIMS: Celiac disease is a gluten-induced enteropathy characterized
by the presence of gliadin-specific CD4(+) T cells in the lamina propria and by a
prominent intraepithelial T-cell infiltration of unknown mechanism. The aim of
this study was to characterize the subset(s) of intraepithelial lymphocytes
(IELs) expanding during active celiac disease to provide insights into the
mechanisms involved in their expansion. METHODS: Flow-cytometric analysis of
isolated IELs and/or immunohistochemical staining of frozen sections were
performed in 51 celiac patients and 50 controls with a panel of monoclonal
antibodies against T-cell and natural killer (NK) receptors. In addition, in
vitro studies were performed to identify candidate stimuli for NK receptor
expression. RESULTS: In normal intestine, different proportions of IELs, which
were mainly T cells, expressed the NK receptors CD94/NKG2, NKR-P1A, KIR2D/3D,
NKp46, Pen5, or CD56. During the active phase of celiac disease, the frequency of
CD94(+) IELs, which were mostly alphabeta T cells, was conspicuously increased
over controls. In contrast, the expression of other NK markers was not modified.
Furthermore, expression of CD94 could be selectively induced in vitro by T-cell
receptor activation and/or interleukin 15, a cytokine produced by intestinal
epithelial cells. CONCLUSIONS: The gut epithelium favors the development of T
cells that express NK receptors. In active celiac disease, there is a specific
and selective increase of IELs expressing CD94, the HLA-E-specific NK receptor
that may be related to T-cell receptor activation and/or interleukin 15
secretion.
PMID- 10784589
TI - Gastric mucosal responses to intrahepatic portosystemic shunting in patients with
cirrhosis.
AB - BACKGROUND & AIMS: The response of gastric mucosal lesions in cirrhotic patients
with portal hypertension, namely, portal hypertensive gastropathy (PHG) and
gastric vascular ectasia (GVE), to transjugular intrahepatic portosystemic shunts
(TIPS) is not known. METHODS: Clinical and laboratory evaluation, upper
gastrointestinal endoscopy, and Doppler ultrasonography were performed before
placement of TIPS and 6 weeks, 3 months, and 6 months after TIPS in 54 patients.
Thirty patients had mild PHG, 10 had severe PHG, and 14 had GVE. RESULTS:
Approximately 75% of the patients with severe PHG responded to TIPS as shown by
improvement in endoscopic findings and by a decrease in transfusion requirements;
89% of patients with mild PHG had endoscopic resolution. Patients with GVE had
neither endoscopic resolution nor a decrease in transfusion requirements after
TIPS. There was no difference in mortality between the 2 groups. CONCLUSIONS: The
results support the position that severe PHG and GVE may be different lesions.
Mild and severe PHG respond to TIPS. Because GVE does not respond to TIPS, we
recommend that TIPS be avoided for the treatment of gastrointestinal bleeding
associated with GVE.
PMID- 10784590
TI - Impaired human gallbladder lipid absorption in cholesterol gallstone disease and
its effect on cholesterol solubility in bile.
AB - BACKGROUND & AIMS: The role of the gallbladder in gallstone pathogenesis is still
unclear. We examined the effects of gallbladder mucosal lipid absorption on lipid
composition and cholesterol crystallization in bile. METHODS: The in vitro
isolated, intra-arterially perfused gallbladder model was used (1) to compare the
absorption rates of lipids from standard bile by gallbladders obtained from 7
patients with cholesterol gallstones and 6 controls; and (2) to measure the
microscopic cholesterol crystal detection time in cholesterol-enriched pig bile
before and after lipid absorption by the pig gallbladder. RESULTS: Control
gallbladders, but not cholesterol gallstone gallbladders, significantly reduced
cholesterol (P < 0.02) and phospholipid (P < 0.01) and increased bile salt (P <
0.01) molar percentages in bile over a 5-hour period by efficient and selective
cholesterol and phospholipid absorption. A histomorphometric study of the
epithelial cells showed significantly higher values for nuclear density (P <
0.01) and nuclear (P < 0.05) and cytoplasmic (P < 0.05) areas in the cholesterol
gallstone than the control group. Sequential microscopy of cholesterol-enriched
pig bile showed significantly shorter cholesterol filament (P < 0.01) and typical
cholesterol plate (P < 0. 02) detection times before than after exposure of bile
to the gallbladder lipid absorption. CONCLUSIONS: In cholesterol gallstone
disease, the human gallbladder epithelium loses its capacity to selectively and
efficiently absorb cholesterol and phospholipids from bile, even if it is
hyperplastic and hypertrophic. This epithelial dysfunction eliminates the
positive effect that the normal gallbladder exerts on cholesterol solubility in
bile and might be a pathogenetic cofactor for cholesterol gallstone formation.
PMID- 10784591
TI - Role of ATP7B in biliary copper excretion in a human hepatoma cell line and
normal rat hepatocytes.
AB - BACKGROUND & AIMS: Wilson's disease is a genetic disorder characterized by the
accumulation of copper in the body caused by a defect of biliary copper
excretion. The Wilson's disease gene has been cloned; however, the precise
localization of the gene product (ATP7B) and its role in biliary copper excretion
have not been clarified. METHODS: We constructed a chimeric protein between green
fluorescent protein (GFP) and ATP7B (GFP-ATP7B) and expressed it in a human
hepatoma cell line (Huh7) and isolated rat hepatocytes. The Golgi apparatus, late
endosomes, lysosomes, and bile canaliculus were visualized by fluorescence
microscopy. Brefeldin A and nocodazole were used to redistribute the Golgi
proteins. Bafilomycin A1 was used to analyze the association between GFP-ATP7B
and the late endosomes. RESULTS: GFP-ATP7B colocalized with rhodamine-dextran and
late endosome markers but not with the Golgi markers, lysosome markers, or a
tight junction protein. Brefeldin A and nocodazole redistributed the Golgi
proteins, but they did not affect the distribution of ATP7B. CONCLUSIONS:
Although it is widely believed that ATP7B is located at the Golgi apparatus, its
main localization is in late endosomes. ATP7B seems to translocate copper from
the cytosol to the late endosomal lumen, thus participating in biliary copper
excretion via lysosomes.
PMID- 10784592
TI - Glucagon-induced expression of the MAP kinase phosphatase MKP-1 in rat
hepatocytes.
AB - BACKGROUND & AIMS: Glucagon exerts pleiotropic effects on liver function, but the
underlying signal transduction is incompletely understood. We investigated the
effect of glucagon on the mitogen-activated protein (MAP) kinase phosphatase MKP
1 expression. METHODS: The effect of glucagon on MKP-1 expression was studied in
cultured rat hepatocytes. RESULTS: Glucagon (10-100 nmol/L) and 8-CPT-cAMP (10 or
50 micromol/L) stimulated in rat hepatocytes the expression of MKP-1 messenger
RNA and protein, which became maximal within 30 minutes and declined to nearly
basal levels after 60 minutes. MKP-1 induction by glucagon was sensitive to
inhibition of adenylate cyclase and protein kinase A. The protein kinases G and
C, Ca(2+), MAP kinases, reactive oxygen intermediates, and cellular dehydration
were not involved in the glucagon-induced signaling to MKP-1. MKP-1 expression
correlated with glucagon-induced antagonization of MAP kinase phosphorylation by
epidermal growth factor in hepatocytes. CONCLUSIONS: The MKP-1 response to
glucagon produces an additional level of interaction with MAP kinase-dependent
processes, which may contribute to the regulation of liver function by glucagon
or other cAMP-elevating agents.
PMID- 10784593
TI - Contribution of nitric oxide to the pathogenesis of cirrhotic cardiomyopathy in
bile duct-ligated rats.
AB - BACKGROUND & AIMS: Decreased cardiac contractility and beta-adrenergic
responsiveness have been observed in cirrhosis, but the etiology remains unclear.
We aimed to test the role of nitric oxide (NO), a negative inotropic agent, in
the pathogenesis of cirrhotic cardiomyopathy in a rat model. METHODS: Cirrhosis
was induced by bile duct ligation. Four weeks after ligation or sham operation,
cardiac levels of tumor necrosis factor (TNF)-alpha, guanosine 3,5'-cyclic
monophosphate (cGMP), inducible NOS (NOS2), and endothelial constitutive NOS
(NOS3) messenger RNA (mRNA) and protein were determined. Serum nitrite/nitrate
level was measured. Cardiac contractile function was evaluated in isolated left
ventricular papillary muscles in the absence and presence of the NOS inhibitor
nitro-L-arginine methyl ester (L-NAME). RESULTS: Cardiac TNF-alpha, NOS2 mRNA and
protein, cGMP, and serum interleukin (IL)-1beta and nitrite/nitrate levels were
significantly higher in cirrhotic rats than sham controls. No significant
differences in NOS3 mRNA or protein were found between cirrhotic and sham control
rats. Baseline isoproterenol-stimulated papillary muscle contractile force was
significantly lower in the cirrhotic group; with L-NAME incubation, contractile
force increased significantly in cirrhotic rats but was unaffected in the
controls. In normal papillary muscles, IL-1beta attenuated the contractility, but
coincubation with L-NAME again reversed this attenuation. Incubation with the
exogenous NO donor S-nitroso-N-acetyl-penicillamine also blunted papillary muscle
contractility. CONCLUSIONS: These results suggest that cytokine-induced
stimulation of NOS2 plays a significant role in the pathogenesis of cirrhotic
cardiomyopathy.
PMID- 10784594
TI - American Gastrointestinal Association. Our new president--Thomas A. Brasitus,
M.D.
PMID- 10784595
TI - American Gastroenterological Association Medical Position Statement: guidelines
on intestinal ischemia.
AB - This document presents the official recommendations of the American
Gastroenterological Association (AGA) on intestinal ischemia. It was approved by
the Clinical Practice and Practice Economics Committee on September 25, 1999, and
by the AGA Governing Board on November 15, 1999.
PMID- 10784596
TI - AGA technical review on intestinal ischemia. American Gastrointestinal
Association.
AB - This literature review and the recommendations therein were prepared for the
American Gastroenterological Association Clinical Practice and Practice Economics
Committee. The paper was approved by the committee on September 25, 1999, and by
the AGA Governing Board on November 25, 1999.
PMID- 10784597
TI - If aggressive surveillance in hereditary nonpolyposis colorectal cancer is now
state of the art, are there any challenges left?
PMID- 10784598
TI - Rectal distention: from sensation to feeling.
PMID- 10784600
TI - Urgent endoscopy with endoscopic therapy for acute diverticular bleeding.
PMID- 10784599
TI - Do mucosal T cells prevent intestinal inflammation?
PMID- 10784601
TI - Diagnostic testing after fecal occult blood testing: compliance is the issue.
PMID- 10784602
TI - NASH: Can we iron out the pathogenesis?
PMID- 10784603
TI - Textbook of gastroenterology
PMID- 10784605
TI - Regulatory role of mature B cells in a murine model of inflammatory bowel
disease.
AB - The spontaneous chronic colitis in TCR alpha mutant (TCRalpha(-/-)) mice mediated
by CD4(+) TCRalpha(-)beta(+) T cells is more severe in the absence of mature B
cells, suggesting a suppressive role of B cells and Ig in the development of
chronic colitis. To investigate the direct role of B cells in the suppression of
this colitis, cell transfer studies were performed in TCRalpha(-/-) x Igmu(-/-)
(alphamu(-/-)) double-knockout mice. The chronic colitis was markedly attenuated
in alphamu(-/-) mice after the adoptive transfer of peripheral B cells from
TCRalpha(-/-) mice into 3- to 4-week-old alphamu(-/-) mice prior to the
development of colitis. Furthermore, transfer of mature B cells from TCRalpha(-/
) mice markedly decreased the number of pathogenic colonic CD4(+) TCRalpha(
)beta(+) T cells in alphamu(-/-) mice with established colitis. This B cell
effect required the presence of functional co-stimulatory molecules CD40 and B7-2
(CD86) but not B7-1 (CD80). These results indicate that mature B cells play an
important role in the development of chronic colitis in TCRalpha(-/-) mice by
directly regulating the pathogenic T cells (CD4(+) TCRalpha(-)beta(+) T cells).
PMID- 10784604
TI - gammadelta T cells of human early pregnancy decidua: evidence for cytotoxic
potency.
AB - The immune compromise in decidua allows a semiallogeneic fetus to survive without
impairing the ability of the maternal immune system to fight infections.
Cytotoxic mechanisms are likely to be important in this compromise. Using RT-PCR,
immunoflow cytometry and immunoelectron microscopy, the cytotoxic potential of
isolated human decidual gammadelta T cells was studied. mRNA for perforin (Pf),
granzymes A and B, granulysin and Fas ligand (FasL) was simultaneously expressed
in decidual gammadelta T cells. Pf and FasL were not expressed on the cell
surface. However, the cells constitutively synthesized Pf and stored it in
cytolytic granules. Within the granules Pf mainly resided in the granule core
formed by Pf-containing microvesicles. Ultrastructurally, three groups of Pf
containing granules were distinguished. They probably represent different stages
of granule maturation in a process where Pf-containing microvesicles first attach
to the core cortex and then are translocated across the cortex into the core.
Presynthesized FasL was also stored in the core and microvesicles of the
cytolytic granules. Upon degranulation by ionomycin/Ca(2+) treatment, FasL was
rapidly translocated to the cell surface, demonstrating that its surface
expression was not controlled by de novo biosynthesis. Thus decidual gammadelta T
cells appear to perform Pf- and FasL-mediated cytotoxicity utilizing a common
secretory mechanism based on cytolytic granule exocytosis. The first cytochemical
visualization of lipids in the cytolytic granules is provided. These
intragranular lipids probably wrap up the core and participate in packaging of
the cytotoxic proteins as well as in the killing process. An ultrastructural
model of a cytolytic granule is presented.
PMID- 10784606
TI - PRELI, the human homologue of the avian px19, is expressed by germinal center B
lymphocytes.
AB - We report the identification of a human cDNA encoding a 25 kDa protein of
relevant evolutionary and lymphoid interest (PRELI). PRELI was cloned by
screening a B lymphocyte-specific cDNA library with a probe generated by mRNA
differential display. PRELI amino acid sequence is 85% similar to the avian px19
protein, expressed within the blood islands and in the liver during avian embryo
development. PRELI and px19 contain tandem repeats (A/TAEKAK) of the late
embryogenesis abundant (LEA) motif, characteristic of a group of survival
molecules and originally thought to be present only in plant proteins.
Interestingly, PRELI expression is high in the fetal liver, a major site for B
cell lymphopoiesis, while the mRNA levels in other fetal tissues such as the
brain, lung, and kidney are comparatively low. At the adult stage, PRELI
expression is drastically reduced in the liver but exhibits high mRNA levels in
the spleen, brain, lung and kidney tissues, suggesting that PRELI expression may
be important for the development of vital and immunocompetent organs. Moreover,
PRELI is also highly expressed in the adult lymph nodes and peripheral blood
leukocytes, further stressing that at the adult stage, PRELI expression may be
important during secondary immune responses. Consistent with this hypothesis, the
expression of PRELI is predominant within germinal centers (GC), a stage in which
B lymphocytes are under a stressful selection pressure. Taken together these
data: (i) strongly support the notion that the conserved LEA motif represents a
phylogenetic link between plants and animals, (ii) reveal a novel molecule whose
expression may play a role in the maturation of distinct human tissues, and (iii)
suggest that PRELI expression may be important for GC B lymphocytes.
PMID- 10784607
TI - In vivo identification of lymphocyte subsets exhibiting transcriptionally active
NF-kappaB/Rel complexes.
AB - To analyze the NF-kappaB/Rel activity pattern in a living organism, we previously
generated transgenic mice carrying a kappaB-dependent lacZ gene. In situ analysis
of both primary and secondary lymphoid organs revealed a strong NF-kappaB
transcriptional activity in antigen-presenting cells, some endothelial cells and
sinus lining cells of the lymph node capsula with very little activity in
lymphocytes and thymocytes. Using fluorescein-di-beta-D-galactopyranoside (FDG)
as a vital substrate for the beta-galactosidase, we re-examined by flow cytometry
the NF-kappaB/Rel transcriptional activity in our mouse model. We report here
that such constitutive NF-kappaB/Rel activity was significantly detected in
thymocytes at the CD44+CD25(-) stage. This constitutive activity extended with
CD25 expression to the majority of the CD44(-)CD25(+) thymocytes and was then
restricted to a few mature T cells. In the spleen, constitutive NF-kappaB/Rel
activity was found in most B cells, unlike T cells which were largely negative.
Virgin IgD(+) B cells expressed higher levels of NF-kappaB transcriptional
activity than other B cell types. Altogether, these results suggest that NF
kappaB/Rel complexes are key players in the in vivo differentiation of IgD(+) B
lymphocytes and possibly CD25(+) thymocytes.
PMID- 10784608
TI - Antigen-specific cellular hyporesponsiveness in a chronic human helminth
infection is mediated by T(h)3/T(r)1-type cytokines IL-10 and transforming growth
factor-beta but not by a T(h)1 to T(h)2 shift.
AB - Exposure to infective larvae of the filarial nematode Onchocerca volvulus (Ov)
either results in patent infection (microfilaridermia) or it leads to a status
called putative immunity, characterized by resistance to infection. Similar to
other chronic helminth infections, there is a T cell proliferative
hyporesponsiveness to Ov antigen (OvAg) by peripheral blood mononuclear cells
(PBMC) from individuals with patent infection, i.e. generalized onchocerciasis
(GEO), compared to PBMC from putatively immune (PI) individuals. In this study,
mechanisms mediating this cellular hyporesponsiveness in GEO were investigated:
the low proliferative response in PBMC from GEO individuals was associated with a
lack of IL-4 production and significantly lower production of IL-5 compared to
those from PI individuals, arguing against a general shift towards a T(h)2
response being the cause of hyporesponsiveness. In contrast, IL-10 and
transforming growth factor (TGF)-beta, two cytokines associated with a T(h)3
response, seemed to mediate hyporesponsiveness: PBMC from individuals with GEO
produced significantly more IL-10, and T cell proliferative hyporesponsiveness in
this group could be reversed by the addition of anti-IL-10 and anti-TGF-beta
antibodies. Hyporesponsiveness was specific for OvAg and not observed upon
stimulation with related nematode antigens, arguing for a T cell-mediated, Ov
specific down-regulation. Ov-specific T cells could be cloned from GEO PBMC which
have a unique cytokine profile (no IL-2 but high IL-10 and/or TGF-beta
production), similar to the T cell subsets known to suppress ongoing inflammation
(T(h)3 and T(r)1), indicating that this cell type which has not been found so far
in infectious diseases may be involved in maintaining Ov-specific
hyporesponsiveness.
PMID- 10784609
TI - Cyclin D2 is essential for BCR-mediated proliferation and CD5 B cell development.
AB - Progression into G(1) in B lymphocytes is regulated by cyclins D2 and D3,
components of the cell cycle machinery currently believed to have overlapping and
potentially redundant roles in cell cycle control. To study the specific role of
cyclin D2 in B lymphocyte proliferation, we examined B cells from cyclin D2(-/-)
mice and demonstrate a specific requirement for cyclin D2 in BCR- but not CD40-
or lipopolysaccharide-induced proliferation. Furthermore, conventional B cell
development proceeds normally in the mutant mice; however, the CD5 B cell
compartment is dramatically reduced, suggesting that cyclin D2 is important in
CD5 B cell development as well as antigen-dependent B cell clonal expansion.
PMID- 10784610
TI - TCR v(beta) usage and clonality of T cells isolated from progressing and rejected
tumor sites before and after in vitro culture.
AB - A gelatin sponge model of concomitant tumor immunity was employed in order to
examine the clonality of T cells associated with progressing and rejected tumor
sites. Here we show that freshly isolated T cells bearing TCR V(beta)1, CDR3
RPGTGN, J(beta)1.1 and TCR V(beta)8, CDR3 GD, J(beta)1.6 predominated progressing
and rejected tumor sites. Despite the similarity in T cell populations, the T
cells from rejected tumor sites were capable of killing the autologous tumor
cells, whereas T cells from progressing tumor sites were not able to do so. The
differing cytolytic ability could not be attributed to a difference in TCR zeta
chain protein expression levels between both T cell populations. After a 5 day
mixed lymphocyte tumor culture the T cells from the progressing tumor site were
capable of killing autologous tumor cells, which suggested changes took place
within the cell population during in vitro culture. Further TCR analysis revealed
T cells bearing TCR V(beta)1, CDR3 RPGTGN, J(beta)1.1 and TCR V(beta)8, CDR3 GD,
J(beta)1.6 were not expanded following the in vitro culture. These data suggest
that the lack of cytotoxicity of freshly isolated tumor-infiltrating lymphocytes
(TIL) was not due to abnormal TCR zeta chain expression or major differences in
the TCR V(beta) usage. Additionally, the gain of TIL effector function did not
correlate with an expansion of the TCR bearing T cells found to predominate the
in vivo response. These data suggest that the predominant TCR V(beta) used by
lymphocytes infiltrating regressing or rejected tumors may not represent the
tumor reactive T cells that grow in culture or respond to the autologous tumor in
vitro.
PMID- 10784611
TI - Glycine-rich cell wall proteins act as specific antigen targets in autoimmune and
food allergic disorders.
AB - Our objective was to investigate the presence of a B and T cell immune response
directed against the glycine-rich cell wall protein (GRP) in patients with
different autoimmune disorders and with food allergy. GRP is an ubiquitous food
protein that has high homology with cytokeratins and other self proteins [Epstein
Barr virus nuclear antigen-1 (EBNA-I), heterogeneous nuclear ribonucleoprotein,
fibrillar collagen] which are common targets in autoimmune disorders. A peptide
(GGYGDGGAHGGGYGG) derived from GRP was used to screen human sera in direct and
competitive ELISA assay. Anti-GRP-specific IgG were analyzed for their ability to
cross-react with autoantigens. The intracellular cytokine profiles of the peptide
specific T cell clones obtained from representative patients have been studied.
BALB/c mice were immunized with the peptide coupled to the carrier protein
keyhole limpet hemocyanin (KLH). Serum IgG antibodies directed against the GRP
peptide were detected in several autoimmune disorders and in food allergic
patients, and were able to cross-react with autoantigens including keratin,
collagen and EBNA-I. Twenty-five T cell clones showed a specific proliferative
response to the GRP peptide and were of the T(h)0 phenotype. Eight of the 10
BALB/c mice immunized with the peptide coupled to KLH developed an autoimmune
response. Our data suggest that phylogenetically highly conserved epitopes in
plants, viruses and humans may be responsible for an autoimmune response in
susceptible individuals. They also indicate that the antigen spreading of a
particular sequence among apparently divergent proteins may participate to
initiate or amplify an immune response.
PMID- 10784612
TI - Cartilage-reactive T cells in rheumatoid synovium.
AB - Rheumatoid arthritis (RA) is an inflammatory polyarthritis genetically linked to
HLA-DR4 and related haplotypes. RA synovial tissue is characterized by T cell
infiltration and activation of macrophage-like cells, strongly implicating a T
cell-antigen-presenting cell (APC) interaction in RA pathogenesis. To investigate
the nature of the antigens driving the T cell response, synovial tissue was
obtained from a patient with chronic RA and T cells were enriched. These T cells
were stimulated by endogenous APC from the same synovial tissue. The T cell lines
were subsequently evaluated for responsiveness to autologous APC and cartilage
antigens. Specific proliferative responses to autologous APC which were enhanced
by cartilage extract were seen. Immunomagnetic bead selection and RT-PCR was used
to identify TCR alphabeta pairs which appeared to respond to antigen(s) in the
cartilage extract. T cell clones derived from the same joint were shown to
release IL-2 in response to the cartilage extract and expressed a related TCR.
With these experiments we have shown direct evidence that autoreactive T cells
are found within the inflamed rheumatoid synovium and, further, that the antigens
driving these T cells are cartilage derived. Since the antigens recognized by
these populations of T cells are found within cartilage our data provides
evidence that RA pathology could be related to a self-driven autoimmune response
to cartilage proteins.
PMID- 10784613
TI - Tumor angiogenesis factors reduce leukocyte adhesion in vivo.
AB - Leukocyte-endothelium interactions are diminished in tumors. It is reported here
that, in a tumor-free in vivo model, angiogenic factors can down-regulate
leukocyte adhesion to endothelium. Slow releasing pellets were loaded with either
basic fibroblast growth factor (bFGF), vascular endothelial cell growth factor
(VEGF) or vehicle alone and were placed in the scrotum of mice. After 3 days, a
single intrascrotal injection of 1 microg/kg IL-1beta was given 4 h before
vessels of the cremaster muscle were investigated for leukocyte rolling and
adhesion by means of intravital microscopy. Exposure of normal tissue to either
bFGF or VEGF resulted in markedly decreased levels of cytokine-induced leukocyte
adhesion. Suppression of leukocyte rolling was not observed. Instead a moderate
enhancement of rolling by VEGF was found. The observed differences could not be
explained by differences in fluid dynamic parameters or systemic leukocyte
counts. In conclusion, evidence is presented that, in vivo, angiogenic factors
significantly reduce leukocyte adhesion, the final step preceding leukocyte
infiltration. This observation may explain why tumors escape from immune
surveillance.
PMID- 10784614
TI - B cell- and monocyte-activating chemokine (BMAC), a novel non-ELR alpha
chemokine.
AB - A novel alpha-chemokine, designated KS1, was identified from an EST database of a
murine immature keratinocyte cDNA library. The EST has 94% similarity to a
recently cloned human gene, BRAK, that has no demonstrated function. Northern
analysis of mouse and human genes showed detectable mRNA in brain, intestine,
muscle and kidney. Tumour panel blots showed that BRAK was down-regulated in
cervical adenocarcinoma and uterine leiomyoma, but was up-regulated in breast
invasive ductal carcinoma. KS1 bound specifically to B cells and macrophages, as
well as two B cell lines, CESS and A20, and a monocyte line, THP-1. KS1 showed no
binding to naive or activated T cells. In addition, KS1 stimulated the chemotaxis
of CESS and THP-1 cells but not T cells. The s.c. injection of KS1 creates a
mixed inflammatory response in Nude and C3H/HeJ mice. The above data indicates
that KS1 and its human homologue represents a novel non-ELR alpha-chemokine that
may have important roles in trafficking of B cells and monocytes. We propose the
name B cell- and monocyte-activating chemokine (BMAC) for this molecule to
reflect the described biological functions.
PMID- 10784615
TI - Defensins act as potent adjuvants that promote cellular and humoral immune
responses in mice to a lymphoma idiotype and carrier antigens.
AB - Defensins released by neutrophils are able to kill a broad spectrum of microbes.
They also induce leukocyte migration in vitro and elicit inflammatory leukocyte
responses at s.c. injection sites in mice. In vitro experiments showed that human
defensins enhanced concanavalin A-stimulated murine spleen cell proliferation and
IFN-gamma production. This led us to examine the effects of human defensins on
specific immune responses in vivo. BALB/c mice were immunized with 50 microg of
keyhole limpet hemocyanin (KLH) adsorbed to aluminum hydroxide and administered
with defensins in aqueous solution. Intraperitoneal administration of defensins
significantly increased the production of KLH-specific IgG1, IgG2a and IgG2b
antibodies 14 days after immunization. In vitro splenic KLH-specific
proliferative responses were higher in mice treated with KLH and defensins than
in those treated with KLH alone. Increased IFN-gamma and, to a lesser extent, IL
4 production were also detected in the supernatants of ex vivoKLH-activated
spleen cells from mice treated with defensins. Finally, defensins significantly
enhanced the antibody response to a syngeneic tumor antigen, lymphoma Ig idiotype
and also augmented resistance to tumor challenge. These results indicate that
defensins act as potent immune adjuvants by inducing the production of
lymphokines, which promote T cell-dependent cellular immunity and antigen
specific Ig production. Thus, defensins appear to function as neutrophil-derived
signals that promote adaptive immune responses.
PMID- 10784616
TI - Differential IL-12 responsiveness of T cells but not of NK cells from tumor
bearing mice in IL-12-responsive versus -unresponsive tumor models.
AB - While IL-12 administration induces tumor regression through stimulating T cells
in tumor-bearing mice, this IL-12 effect is observed in some but not all tumor
models. The present study aimed to compare IL-12 responsiveness of T cells from
tumor-bearing mice in IL-12-responsive (CSA1M and OV-HM) and -unresponsive (Meth
A) tumor models. Tumor regression in IL-12-responsive tumor models required the
participation of T cells, but not of NK1.1(+) cells. Because a NK1.1(+) cell
population was the major producer of IFN-gamma, comparable levels of IFN-gamma
production were induced in IL-12-responsive and -unresponsive tumor-bearing mice.
This indicates that the amount of IFN-gamma produced in tumor-bearing individuals
does not correlate with the anti-tumor efficacy of IL-12. In contrast, IL-12
responsiveness of T cells differed between the responsive and unresponsive
models: purified T cells from CSA1M/OV-HM-bearing or Meth A-bearing mice
exhibited high or low IL-12 responsiveness respectively, when evaluated by the
amounts of IFN-gamma produced in response to IL-12. T cells from CSA1M- or OV-HM
bearing but not from Meth A-bearing mice exhibited enhanced levels of mRNA for
the IL-12 receptor (IL-12R). These results indicate that a fundamental difference
exists in IL-12 responsiveness of T cells between IL-12-responsive and
unresponsive tumor models, and that such a difference is associated with the
expression of IL-12R on T cells.
PMID- 10784617
TI - Short-lived immunization site inflammation in self-limited active experimental
allergic encephalomyelitis.
AB - To understand the mechanisms underlying spontaneous remission of proteolipid
protein (PLP) 139-151 peptide-induced experimental allergic encephalomyelitis
(EAE), an acute autoimmune disease of SJL mice resembling human multiple
sclerosis, we examined both the effector response site in the central nervous
system (CNS) and the immunization site at different phases of the disease. In the
CNS, the frequency of PLP 139-151 peptide-specific IFN-gamma-producing T cells as
well as the amount of infiltrating CD4(+) and CD11b(+) cells decreased with
recovery. However, IL-4-producing cells were always rare and cyclooxygenase-2(+)
cells were numerous only at disease peak in the CNS, suggesting that T(h)2
cytokines and prostaglandins did not determine remission of EAE. By looking at
the s.c. site of PLP 139-151 peptide plus adjuvant injection, we found that,
although the inflammatory infiltrate was abundant, CD11b(+) cells started to
decrease already during disease acute phase and DEC-205(+) cells were numerous
only at early time points. We propose that immunization site inflammation is
short-lived in PLP 139-151 peptide-induced EAE, and this leads to a temporary
autoreactive T cell stimulation and to a self-limited disease.
PMID- 10784618
TI - The DNA-bending protein, HMG1, is required for correct cleavage of 23 bp
recombination signal sequences by recombination activating gene proteins in
vitro.
AB - DNA-bending proteins are known to facilitate the in vitro V(D)J joining of
antigen receptor genes. Here we report that the high-mobility group protein,
HMG1, is necessary for the correct nicking of the 23 bp recombination signal
sequence (23-RSS) by the recombination [corrected] activating gene (RAG)
proteins, RAG1 and RAG2. Without HMG1, the mouse Jkappa1 23-RSS was recognized as
if it were the 12-RSS and nicked at a site 12 + 7 nucleotides away from the 9mer
signal, even though no 7mer-like sequence was evident at the cryptic nicking
site. When increased amounts of HMG1 were added, the 23-RSS substrate was nicked
correctly at a site 23 + 7 nucleotides from the 9mer, and nicking at the cryptic
site disappeared. Unlike the 23-RSS, the 12-RSS did not require HMG1 for correct
nicking, although HMG1 was found to increase the interaction between RSS and RAG
proteins. Modification-interference assays demonstrated that HMG1 caused changes
in the interaction between the 23-RSS and RAG proteins specifically at the 7mer
and the cryptic nicking site.
PMID- 10784619
TI - DEC-205 as a marker of dendritic cells with regulatory effects on CD8 T cell
responses.
AB - We have previously reported that a population of lymphoid-related CD8alpha(+) DEC
205(+) dendritic cells (DC) from mouse spleen have 'regulatory' effects on the T
cells they activate. CD8 T cells produce IL-2 and give a sustained proliferative
response to allogeneic CD8alpha(-) DEC-205(-) splenic DC, but produce little IL-2
and give a limited response to allogeneic CD8(+) DEC-205(+) splenic DC. Although
CD8alpha and DEC-205 correlate closely among splenic DC, lymph nodes (LN) include
a large population of CD8alpha(low) DEC-205(high) DC. By i.v. transfer of
purified thymic early lymphoid precursors into irradiated recipient mice we now
demonstrate that these CD8alpha(low) but DEC-205(high) LN DC can be the progeny
of a lymphoid precursor population, apparently corresponding to the
CD8alpha(high) DEC-205(high) DC progeny of the same precursors in spleen and
thymus. By culture of the separated, purified DC with allogeneic CD8 T cells we
demonstrate that the CD8alpha(low) DEC-205(high) DC of LN are also functionally
equivalent to the CD8alpha(high) DEC-205(high) DC of spleen. Therefore, DEC-205
but not CD8alpha serves to segregate functionally distinct DC types in LN.
However, DC isolated from the spleens of genetically manipulated DEC-205(null)
mice and separated on the basis of CD8alpha expression have a similar capacity to
stimulate CD8 T cells as their heterozygous littermate controls, with the
CD8alpha(+) but now DEC-205(null) DC still giving restricted responses. In
conclusion, high expression of DEC-205 appears to be a good marker of the
lymphoid-related regulatory type of DC, but DEC-205 itself is not responsible for
transmitting negative signals to the T cells.
PMID- 10784620
TI - Oligonucleotide therapeutics: a step forward.
PMID- 10784621
TI - Phase I clinical and pharmacokinetic study of bcl-2 antisense oligonucleotide
therapy in patients with non-Hodgkin's lymphoma.
AB - PURPOSE: To evaluate the pharmacokinetics and toxicity of an antisense
oligonucleotide targeting bcl-2 in patients with non-Hodgkin's lymphoma (NHL) and
to determine efficacy using clinical and biologic end points. PATIENTS AND
METHODS: Twenty-one patients with Bcl-2-positive relapsed NHL received a 14-day
subcutaneous infusion of G3139, an 18-mer phosphorothioate oligonucleotide
complementary to the first six codons of the bcl-2 open reading frame. Plasma
pharmacokinetics were measured by anion exchange high-performance liquid
chromatography. Response was assessed by computed tomography. Changes in Bcl-2
expression were measured by fluorescence-activated cell sorting of patients'
tumor samples. RESULTS: Eight cohorts of patients received doses between 4. 6 and
195.8 mg/m(2)/d. No significant systemic toxicity was seen at doses up to 110.4
mg/m(2)/d. All patients displayed skin inflammation at the subcutaneous infusion
site. Dose-limiting toxicities were thrombocytopenia, hypotension, fever, and
asthenia. The maximum-tolerated dose was 147.2 mg/m(2)/d. Plasma levels of G3139
equivalent to the efficacious plasma concentration in in vivo models were
produced with doses above 36.8 mg/m(2)/d. Plasma levels associated with dose
limiting toxicity were greater than 4 microg/mL. By standard criteria, there was
one complete response, 2 minor responses, nine cases of stable disease, and nine
cases of progressive disease. Bcl-2 protein was reduced in seven of 16 assessable
patients. This reduction occurred in tumor cells derived from lymph nodes in two
patients and from peripheral blood or bone marrow mononuclear cell populations in
the remaining five patients. CONCLUSION: Bcl-2 antisense therapy is feasible and
shows potential for antitumor activity in NHL. Downregulation of Bcl-2 protein
suggests a specific antisense mechanism.
PMID- 10784622
TI - Randomized cross-over trial of progenitor-cell mobilization: high-dose
cyclophosphamide plus granulocyte colony-stimulating factor (G-CSF) versus
granulocyte-macrophage colony-stimulating factor plus G-CSF.
AB - PURPOSE: Patient response to hematopoietic progenitor-cell mobilizing regimens
seems to vary considerably, making comparison between regimens difficult. To
eliminate this inter-patient variability, we designed a cross-over trial and
prospectively compared the number of progenitors mobilized into blood after
granulocyte-macrophage colony-stimulating factor (GM-CSF) days 1 to 12 plus
granulocyte colony-stimulating factor (G-CSF) days 7 to 12 (regimen G) with the
number of progenitors after cyclophosphamide plus G-CSF days 3 to 14 (regimen C)
in the same patient. PATIENTS AND METHODS: Twenty-nine patients were randomized
to receive either regimen G or C first (G1 and C1, respectively) and underwent
two leukaphereses. After a washout period, patients were then crossed over to the
alternate regimen (C2 and G2, respectively) and underwent two additional
leukaphereses. The hematopoietic progenitor-cell content of each collection was
determined. In addition, toxicity and charges were tracked. RESULTS: Regimen C (n
= 50) resulted in mobilization of more CD34(+) cells (2.7-fold/kg/apheresis),
erythroid burst-forming units (1.8-fold/kg/apheresis), and colony-forming units
granulocyte-macrophage (2.2-fold/kg/apheresis) compared with regimen G given to
the same patients (n = 46; paired t test, P<.01 for all comparisons). Compared
with regimen G, regimen C resulted in better mobilization, whether it was given
first (P =.025) or second (P =.02). The ability to achieve a target collection of
> or =2x10(6) CD34(+) cells/kg using two leukaphereses was 50% after G1 and 90%
after C1. Three of the seven patients in whom mobilization was poor after G1 had
> or =2x10(6) CD34(+) cells/kg with two leukaphereses after C2. In contrast, when
regimen G was given second (G2), seven out of 10 patients failed to achieve the
target CD34(+) cell dose despite adequate collections after C1. Thirty percent of
the patients (nine of 29) given regimen C were admitted to the hospital because
of neutropenic fever for a median duration of 4 days (range, 2 to 10 days). The
higher cost of regimen C was balanced by higher CD34(+) cell yield, resulting in
equivalent charges based on cost per CD34(+) cell collected. CONCLUSION: We
report the first clinical trial that used a cross-over design showing that high
dose cyclophosphamide plus G-CSF results in mobilization of more progenitors then
GM-CSF plus G-CSF when tested in the same patient regardless of sequence of
administration, although the regimen is associated with greater morbidity.
Patients who fail to achieve adequate mobilization after regimen G can be treated
with regimen C as an effective salvage regimen, whereas patients who fail regimen
C are unlikely to benefit from subsequent treatment with regimen G. The cross
over design allowed detection of significant differences between regimens in a
small cohort of patients and should be considered in design of future comparisons
of mobilization regimens.
PMID- 10784623
TI - Early detection of relapse by hypermetaphase fluorescence in situ hybridization
after allogeneic bone marrow transplantation for chronic myeloid leukemia.
AB - PURPOSE: Standard G-band cytogenetic analysis (CG) provides information on
approximately 25 metaphases for monitoring the presence of Philadelphia
chromosome positive (Ph+) cells in chronic myelogenous leukemia (CML) patients,
making the detection of a low frequency of Ph+ cells problematic. The purpose of
this study was to improve the detection of a low frequency of Ph+ cells. PATIENTS
AND METHODS: We combined fluorescence in situ hybridization (FISH) with long-term
colcemid exposure, capturing several hundred metaphases in bone marrow cultures
(hypermetaphase FISH [HMF]). Using probes that identify Ph+ cells, HMF was
compared with CG analysis in the follow-up evaluations of 51 patients with CML at
various time points after allogeneic bone marrow transplant (BMT). RESULTS:
Thirty-five patients never showed the presence of Ph+ cells by either method. In
four patients, high frequencies of Ph+ cells were detected by both methods. In
the remaining 12 patients, Ph+ cells were detected by HMF at time points after
BMT when they were not detected by CG. In seven of the 12 patients, low but
statistically significant frequencies of Ph+ cells (0.37% to 5.20%) were detected
3 months or later after BMT, and when no intervention was initiated, all seven
patients later relapsed. Based on those data, an eighth patient with mixed
chimerism and a similar HMF-detected Ph+ frequency (1.8% at 27 months after BMT)
was reinfused with donor lymphocytes and achieved remission with 0% Ph+ cells
studied by HMF (up to 50 months after BMT). Ph+ cells detected by HMF but not by
CG less than 3 months after BMT disappeared on later examination in two of four
patients. After detection of Ph+ cells by HMF only, the median time to
cytogenetic progression (detection of Ph+ cells by CG) was 101 days. CONCLUSION:
The results demonstrate the ability of HMF to detect low but clinically relevant
levels of leukemic cells not detected by CG in transplant patients. The data
indicate that HMF can detect low levels of Ph+ cells before standard cytogenetics
at a time that may be useful in monitoring disease status and planning clinical
interventions.
PMID- 10784624
TI - P-Glycoprotein inhibitor valspodar (PSC 833) increases the intracellular
concentrations of daunorubicin in vivo in patients with P-glycoprotein-positive
acute myeloid leukemia.
AB - PURPOSE: The aim of the present study was to evaluate the effect of the
cyclosporine derivative valspodar (PSC 833; Amdray, Novartis Pharma, Basel,
Switzerland) on the concentration of daunorubicin (dnr) in leukemic blast cells
in vivo during treatment. PATIENTS AND METHODS: Ten patients with acute myeloid
leukemia (AML) were included. Leukemic cells from seven of the patients were P
glycoprotein (Pgp)-positive. dnr 100 mg/m(2) was given as a continuous infusion
over 72 hours. After 24 hours, a loading dose of valspodar was given, followed by
a 36-hour infusion of 10 mg/kg per 24 hours. Blood samples were drawn at regular
intervals, and concentrations of dnr and its main metabolite, daunorubicinol, in
plasma and isolated leukemic cells were determined by high-pressure liquid
chromatography. RESULTS: The mean dnr concentrations in leukemic cells 24 hours
after the start of infusion (before valspodar) were 18.8 micromol/L in Pgp
negative samples and 13.5 micromol/L in Pgp-positive samples. After 8 hours of
valspodar infusion, these values were 25.8 and 24.0 micromol/L, respectively. The
effect of valspodar was evaluated from the ratio of the area under the curve
(AUC) for dnr concentration versus time in leukemic cells to the AUC for dnr
concentration against time in the plasma. For the seven patients with Pgp
positive leukemia, the mean ratio increased by 52%, from 545 on day 1 to 830 on
day 2 (P<.05) when valspodar was given. In the three patients with Pgp-negative
leukemia, no significant difference was observed. CONCLUSION: These results
strongly suggest that valspodar, by interacting with Pgp, can increase the
cellular uptake of dnr in leukemic blasts in vivo.
PMID- 10784625
TI - Alpha hemolytic streptococcal infection during intensive treatment for acute
myeloid leukemia: a report from the Children's cancer group study CCG-2891.
AB - PURPOSE: Past reports indicate that alpha hemolytic streptococcal (AHS) organisms
are a common cause of infection among acute myeloid leukemia (AML) patients. This
study was intended to ascertain the population incidence and rate (infections per
100 patient-days of treatment) of AHS and to identify associated risk factors.
PATIENTS AND METHODS: Patients (n = 874 with 151,350 days of risk) enrolled on
the Children's Cancer Group (CCG) protocol for newly diagnosed AML, CCG-2891,
which randomly assigned intensity of induction and intensification, were
prospectively evaluated for infectious complications. RESULTS: AHS occurred in
21% of patients, was primarily blood borne (86%), made up 21% of bacteremic
infections, and had a recurrent incidence of 31% during subsequent therapy. AHS
was more often life-threatening (59%) than other infections (41%) (P = .001). AHS
rates increased with age less than 10 years (odds ratio [OR], 2.0; P = .007),
intensively timed induction (OR, 1.8 to 1.9; P = .02), and high-dose cytarabine
intensification (OR, 3.7; P<.0001). Among all courses, the greatest incidence
(19%) and rate (0.41) were associated with the use of high-dose cytarabine.
Gastrointestinal toxicity correlated significantly with AHS bacteremia (P<.01).
Infection with AHS resulted in increased hospital days (P =.0001). Only among
bone marrow transplant patients were overall survival (OR, 2.8; P = .0001) and
disease-free survival (OR, 2.1; P = .008) decreased after AHS bacteremia.
CONCLUSION: This study, the first to prospectively examine AHS incidence among
uniformly treated patients in multiple institutions, established that as the
intensity of AML therapy has increased, so has the rate of AHS. Young children,
those with previous AHS bacteremias, and those receiving high-dose cytarabine are
at particularly high risk of AHS bacteremia.
PMID- 10784626
TI - Partially mismatched related-donor bone marrow transplantation for pediatric
patients with acute leukemia: younger donors and absence of peripheral blasts
improve outcome.
AB - PURPOSE: To extend access to bone marrow transplantation (BMT), we used partially
mismatched related donors (PMRD) for pediatric patients with acute leukemia. In
this report we sought to determine pretransplantation factors that might predict
outcome. PATIENTS AND METHODS: Of 67 such patients, 43 had acute lymphocytic
leukemia and 24 had acute myelogenous leukemia. At the time of transplantation,
41 patients were in relapse. Donors included 40 parents, 24 siblings, and three
cousins. HLA disparity of two to three major antigens was detected in two thirds
of the donor-recipient pairs. Conditioning therapy, including total-body
irradiation and chemotherapy followed by graft-versus-host disease (GvHD)
prophylaxis with partial T-cell depletion of the graft using T10B9 or OKT3, was
combined with posttransplantation immunosuppression. RESULTS: Estimated
probability (EP) of engraftment was 0.96 and was not affected by donor-antigen
mismatch (AgMM; P =.732). EP of grades 2 to 4 acute GvHD was 0.24 and was not
affected by recipient AgMM (P =.796). EP of disease-free survival was 0.26 at 3
years but improved to 0.45 when donors were younger than 30 years (P<.001). EP of
relapse at 3 years was 0.41 and reduced with younger donors' age. For patients
who were in relapse at the time of transplantation, absence of blasts was
associated with a lower relapse rate (0.46 v. 0.84; P =. 083), similar to that of
patients in remission. CONCLUSION: PMRD-BMT in pediatric leukemia resulted in
high engraftment and low GvHD rates. To improve outcomes, younger donors should
be sought, and clinicians should attempt to reduce peripheral blasts in patients
who are in relapse.
PMID- 10784627
TI - Mitoxantrone, etoposide, and cyclosporine therapy in pediatric patients with
recurrent or refractory acute myeloid leukemia.
AB - PURPOSE: To determine the remission rate and toxicity of mitoxantrone, etoposide,
and cyclosporine (MEC) therapy, multidrug resistance-1 (MDR1) status, and steady
state cyclosporine (CSA) levels in children with relapsed and/or refractory acute
myeloid leukemia. PATIENTS AND METHODS: MEC therapy consisted of mitoxantrone 6
mg/m(2)/d for 5 days, etoposide 60 mg/m(2)/d for 5 days, and CSA 10 mg/kg for 2
hours followed by 30 mg/kg/d as a continuous infusion for 98 hours. Because of
pharmacokinetic interactions, drug doses were decreased to 60% of those found to
be effective without coadministration of CSA. MDR1 expression was evaluated by
reverse transcriptase polymerase chain reaction, flow cytometry, and the ability
of CSA at 2.5 micromol/L to increase intracellular accumulation of (3)H
daunomycin in blasts from bone marrow specimens. RESULTS: The remission rate was
35% (n = 23 of 66). Overall, 35% of patients (n = 23) achieved complete remission
(CR), 12% of patients (n = 8) achieved partial remission, and 9% of patients (n =
6) died of infection. Exposure to CSA levels of greater than 2,400 ng/mL was
achieved in 95% of patients (n = 56 of 59). Toxicities included infection,
cardiotoxicity, myelosuppression, stomatitis, and reversible increases in serum
creatinine and bilirubin. In most who had relapsed while receiving therapy or
whose induction therapy had failed, response was not significantly different for
MDR1-positive and MDR1-negative patients. CONCLUSION: Serum levels of CSA capable
of reversing multidrug resistance are achievable in children with acceptable
toxicity. The CR rate of 35% achieved in this study is comparable to previously
reported results using standard doses of mitoxantrone and etoposide. The use of
CSA may have improved the response rate for the MDR1-positive patients so that it
was not different from that for the MDR1-negative patients.
PMID- 10784628
TI - Prognostic impact of trisomies of chromosomes 10, 17, and 5 among children with
acute lymphoblastic leukemia and high hyperdiploidy (> 50 chromosomes).
AB - PURPOSE: Children with acute lymphoblastic leukemia (ALL) and high hyperdiploidy
(> 50 chromosomes) have improved outcome compared with other ALL patients. We
sought to identify cytogenetic features that would predict differences in outcome
within this low-risk subset of ALL patients. MATERIALS AND METHODS: High
hyperdiploid ALL patients (N = 480) were enrolled between 1988 and 1995 on
Children's Cancer Group (CCG) trials. Karyotypes were determined by conventional
banding. Treatment outcome was analyzed by life-table methods. RESULTS: Patients
with 54 to 58 chromosomes had better outcome than patients with 51 to 53 or 59 to
68 chromosomes (P = .0002). Patients with a trisomy of chromosome 10 (P<.0001),
chromosome 17 (P = .0002), or chromosome 18 (P = .004) had significantly improved
outcome compared with their counterparts who lacked the given trisomy. Patients
with a trisomy of chromosome 5 had worse outcome than patients lacking this
trisomy (P = .02). Patients with trisomies of both chromosomes 10 and 17 had
better outcome than those with a trisomy of chromosome 10 (P = .09), a trisomy of
chromosome 17 (P =.01), or neither trisomy (P<.0001). Multivariate analysis
indicated that trisomy of chromosome 10 (P = .001) was the most significant
prognostic factor for high-hyperdiploid patients, yet trisomy of chromosome 17 (P
=.02) or chromosome 5 (P = .01) and modal chromosome number (P = .02) also had
significant multivariate effects. CONCLUSION: Trisomy of chromosomes 10 and 17 as
well as modal chromosome number 54 to 58 identify subgroups of patients with high
hyperdiploid ALL who have a better outcome than high-hyperdiploid patients who
lack these cytogenetic features. Trisomy of chromosome 5 confers poorer outcome
among high-hyperdiploid patients.
PMID- 10784629
TI - Loss of heterozygosity at 1p36 independently predicts for disease progression but
not decreased overall survival probability in neuroblastoma patients: a
Children's Cancer Group study.
AB - PURPOSE: To determine the independent prognostic significance of 1p36 loss of
heterozygosity (LOH) in a representative group of neuroblastoma patients.
PATIENTS AND METHODS: Diagnostic tumor specimens from 238 patients registered
onto the most recent Children's Cancer Group phase III clinical trials were
assayed for LOH with 13 microsatellite polymorphic markers spanning chromosome
band 1p36. Allelic status at 1p36 was correlated with other prognostic variables
and disease outcome. RESULTS: LOH at 1p36 was detected in 83 (35%) of 238
neuroblastomas. There was a correlation of 1p36 LOH with age at diagnosis greater
than 1 year (P = .026), metastatic disease (P<.001), elevated serum ferritin
level (P<.001), unfavorable histopathology (P<.001), and MYCN oncogene
amplification (P<.001). LOH at 1p36 was associated with decreased event-free
survival (EFS) and overall survival (OS) probabilities (P<.0001). For the 180
cases with single-copy MYCN, 1p36 LOH status was highly correlated with decreased
EFS (P = .0002) but not OS (P = .1212). Entering 1p36 LOH into a multivariate
regression model suggested a trend toward an independent association with
decreased EFS (P = .0558) but not with decreased OS (P = .3687). Furthermore,
allelic status at 1p36 was the only prognostic variable that was significantly
associated with decreased EFS in low-risk neuroblastoma patients (P = .0148).
CONCLUSION: LOH at 1p36 is independently associated with decreased EFS, but not
OS, in neuroblastoma patients. Determination of 1p36 allelic status may be useful
for predicting which neuroblastoma patients with otherwise favorable clinical and
biologic features are more likely to have disease progression.
PMID- 10784630
TI - Phase I trials in pediatric oncology: perceptions of pediatricians from the
United Kingdom Children's Cancer Study Group and the Pediatric Oncology Group.
AB - PURPOSE: To identify areas of concern regarding the conduct of phase I trials,
the perceived expectations and motivations of the parents of children entered,
the expectations of toxicity and benefit, and the ethical concerns of pediatric
hematologists and oncologists in the United Kingdom and North America. METHODS: A
survey instrument consisting of 19 open- and closed-ended questions was sent to
United Kingdom Children's Cancer Study Group (UKCCSG)- and Pediatric Oncology
Group (POG)-affiliated pediatricians. RESULTS: Fifty-three UKCCSG- and 78 POG
affiliated pediatricians responded. Thirty-two UKCCSG and 51 POG respondents had
previously entered at least one child into a phase I study. Overall, respondents
believed that parents entered their children for medical benefit, altruism, and
hope of cure. Although many respondents believed that children could benefit from
medical improvement, feelings of altruism, and maintenance of hope, the chance of
cure or complete remission was thought to be small. Similarly, parents were
thought to potentially benefit through altruism and maintenance of hope. Whereas
83% of UKCCSG respondents indicated that phase I trials were associated with
ethical difficulties, this was a concern for 48% of POG respondents. The main
ethical concerns of respondents were risk of toxicity, consent of the child,
unrealistic hope, and coercion. CONCLUSION: The respondents in this survey
expressed mainly ethical concerns regarding the conduct of phase I trials and had
realistic expectations of the potential for toxicity and benefit for those
children who participate in these studies.
PMID- 10784631
TI - Prognostic value of p53 for local failure in mastectomy-treated breast cancer
patients.
AB - PURPOSE: The loss of p53 function is a recognized adverse prognostic factor in
invasive breast cancer. Several studies have shown a relationship between the
nuclear accumulation of p53 protein (a surrogate marker of p53 inactivation) and
poor disease-free and overall survival. In general, however, these studies did
not report the prognostic value of p53 for local failure, which we have therefore
assessed retrospectively here. MATERIALS AND METHODS: Accumulation of p53 protein
was evaluated by immunohistochemistry in 1,530 mastectomy-treated breast cancer
patients (259 radiation therapy [RT]- and 1,271 mastectomy only [No RT]-treated
patients). Statistical comparisons were made between p53 protein accumulation,
estrogen/progesterone receptors, nodal status, tumor size, and local failure rate
(LFR). Local failure was defined as tumor recurrence involving the chest wall
and/or the ipsilateral supraclavicular/axillary lymph nodes. The median follow-up
period was 62 months. RESULTS: In the No RT group, the LFR was 9.1% and 16. 5% in
p53-negative and p53-positive patients, respectively (P<.001). Multivariate
analysis revealed that p53 protein accumulation was significantly associated with
an increased risk of local relapse (relative risk [RR], 1.7; 95% confidence
interval [CI], 1.2 to 2.4). Nodal status and tumor size were also significant
factors. In the RT group, the LFR was 9.3% and 21.5% in p53-negative and p53
positive patients, respectively (P = .009). Multivariate analysis revealed that
p53 protein accumulation was significantly associated with an increased risk of
local relapse (RR, 2.5; 95% CI, 1.1 to 5.7), as was nodal status. CONCLUSION:
Nuclear accumulation of p53 protein is independently associated with a
significantly increased local failure rate in breast cancer patients treated with
mastectomy, with or without radiation.
PMID- 10784632
TI - Detection of circulating tumor cells by reverse transcriptase polymerase chain
reaction of maspin in patients with breast cancer undergoing conventional-dose
chemotherapy.
AB - PURPOSE: To establish, in patients with breast cancer subjected to primary
conventional chemotherapy and enrolled in a prospective study, the mobilizing
effect of therapy on potentially neoplastic cells by means of a reverse
transcriptase polymerase chain reaction (RT-PCR) assay for mRNA of maspin, a
protein related to the serpin family of protease inhibitors. PATIENTS AND
METHODS: Peripheral-blood samples were collected from 30 patients with
histologically proven breast cancer before and 4 and 8 days after conventional
chemotherapy for three consecutive courses. A total of 216 samples were screened
for the presence of maspin mRNA by RT-PCR. RESULTS: Before therapy, all samples
but one were negative. After chemotherapy, 11 patients (38%) had positive
samples. No difference in the rate of positivity was observed between groups
defined according to initial stage, type of chemotherapy, Ki-67-related
proliferative activity, or CA 15.3 expression. CONCLUSION: Our results confirm
that RT-PCR for maspin mRNA is a sensitive assay for the study of circulating
potentially neoplastic mammary cells in patients with breast cancer. Moreover,
our findings indicate a marked effect of conventional-dose chemotherapy on the
mobilization of these cells in breast tumors. In our series of patients, this
phenomenon does not seem to be associated with other known risk factors. Finally,
the data suggest, without proving, an association between the presence of
circulating maspin positive cells and a higher risk of disease progression. If
this association could be confirmed, then the assay could have prognostic
significance. However, larger confirmatory studies are necessary.
PMID- 10784633
TI - Phase II trial of gemcitabine plus cisplatin in patients with metastatic
urothelial cancer.
AB - PURPOSE: To assess the activity and toxicity of the combination of gemcitabine
and cisplatin in the treatment of chemotherapy-naive patients with metastatic
urothelial cancer. PATIENTS AND METHODS: Forty-six patients with measurable stage
IV carcinoma of the urothelium were enrolled onto this trial. Gemcitabine 1,000
mg/m(2) was administered intravenously for 30 to 60 minutes on days 1, 8, and 15
of each 28-day cycle. Cisplatin was administered after gemcitabine on day 1 of
each cycle. The first 11 patients received an initial cisplatin dose of 100
mg/m(2). Due to the hematologic toxicity observed in several of these patients,
the dose was reduced to 75 mg/m(2) in the remaining 35 patients. Patients were
treated with six cycles, unless disease progression or severe toxicity
necessitated earlier discontinuation. RESULTS: Ten of the 46 patients achieved a
complete response and nine showed a partial response. The overall response rate
was 41%. The median time to treatment failure was 5.5 months. The median survival
was 14.3 months, and the 1-year survival probability was 54%. Most of the
toxicities were hematologic and, in general, easily manageable. CONCLUSION:
Gemcitabine plus cisplatin is active in the treatment of metastatic urothelial
cancer in chemotherapy-naive patients and has an acceptable clinical safety
profile. Studies are under way to further define the place of gemcitabine in
combination with other chemotherapeutic agents in the treatment of metastatic
urothelial cancer.
PMID- 10784634
TI - Effect of cytokine therapy on survival for patients with advanced renal cell
carcinoma.
AB - PURPOSE: To evaluate the relationship between treatment with cytokine therapy and
survival, investigate the effect of nephrectomy on survival, and identify long
term survivors among a cohort of 670 patients with advanced renal cell carcinoma
(RCC). PATIENTS AND METHODS: A total of 670 patients with advanced RCC treated on
24 clinical trials of systemic chemotherapy or cytokine therapy were the subjects
of this retrospective analysis. Treatment was categorized as cytokine (containing
interferon alfa and/or interleukin-2) in 396 patients (59%) and as chemotherapy
(cytotoxic or hormonal therapy) in 274 (41%). Among the 670 patients, those with
survival times of greater than 5 years were identified as long-term survivors.
RESULTS: Patients treated with cytokine therapy had a longer survival time than
did those treated with chemotherapy, regardless of the year of treatment or risk
category based on pretreatment features. The median survival times for favorable
, intermediate-, and poor-risk patients were 27, 12, and 6 months for those
treated with cytokines and 15, 7, and 3 months for those treated with
chemotherapy, respectively. The magnitude of difference in median survival was
greater in the favorable- and intermediate-risk groups. The median survival time
was less than 6 months in the poor-risk group for both treatment programs. Median
survival time was 14 months among patients with prior nephrectomy plus time from
diagnosis to treatment greater than 1 year versus 8 months among those with time
from diagnosis to treatment less than 1 year, regardless of pretreatment
nephrectomy status. Thirty patients (4.5%) among the 670 patients were identified
as long-term survivors; 12 were free of disease after nephrectomy and treatment
with interferon alfa, interleukin-2, or surgical resection of metastasis.
CONCLUSION: The low proportion of patients with advanced RCC who achieve long
term survival emphasizes the need for clinical investigation to identify more
effective therapy.
PMID- 10784635
TI - Results of a phase II study using estramustine phosphate and vinblastine in
combination with high-dose three-dimensional conformal radiotherapy for patients
with locally advanced prostate cancer.
AB - PURPOSE: To assess the feasibility and tolerance of neoadjuvant and concomitant
estramustine phosphate and vinblastine (EV) with high-dose three-dimensional
conformal radiotherapy (3D-CRT) for patients with unfavorable-risk prostate
cancer. PATIENTS AND METHODS: Twenty-seven patients with unfavorable-risk
prostate cancer were enrolled onto a prospective study to determine the
feasibility of combining EV with 3D-CRT. Patients were eligible if any of the
following requirements were satisfied: (1) Gleason score > or =8 and prostate
specific antigen (PSA) > 10 ng/mL; (2) Gleason score of 7 and PSA > 20 ng/mL; (3)
clinical stage T3N0M0 disease with PSA > 20 ng/mL; (4) any patient with T4N0M0
disease; or (5) patients with TXN1MO disease. Therapy consisted of three 8-week
cycles of EV and 8 weeks of 3D-CRT. Estramustine phosphate was given orally
beginning on week 1 and continued until the completion of 3D-CRT. Each 8-week
cycle of vinblastine consisted of 6 weekly intravenous injections followed by a 2
week rest period. Radiation therapy was administered using a three-dimensional
conformal approach to a prescription dose of 75.6 Gy. The median follow-up was 26
months (range, 6 to 40 months). RESULTS: Twenty-three (85%) of 27 patients
completed the entire course of therapy and were assessable for toxicities and
biochemical outcome. Two patients (7%) developed grade 3 hematologic toxicity
that resolved, and two patients (7%) developed grade 3 hepatoxicity, manifesting
as persistent elevation of serum transaminase levels, necessitating
discontinuation of the chemotherapy and withdrawal from the treatment program.
The most prominent adverse effects from this regimen were mild to moderate (grade
1 to 2) nausea and fatigue related to estramustine. Mild peripheral edema was
seen in 15% of patients and was treated with diuresis. 3D-CRT was tolerated well
in these patients. Medications were required for relief of acute grade 2 rectal
(gastrointestinal [GI]) and urinary (genitourinary [GU]) symptoms in 35% and 48%
of patients, respectively. Three patients developed acute grade 3 GU toxicities.
The 2-year actuarial likelihood of late grade 2 GI toxicity was 20%. No late
grade 3 or 4 GI toxicities were observed. The 2-year actuarial likelihoods of
late grade 2 and 3 GU toxicities were 25% and 12%, respectively. No grade 4 GU
toxicity was observed. CONCLUSION: Neoadjuvant and concomitant EV with high-dose
3D-CRT is well tolerated in patients with unfavorable-risk prostate cancer.
Although the incidence of modest (grade 2) late GI and GU toxicities seem to be
increased compared with 3D-CRT alone or in combination with androgen ablation
therapy, no severe toxicities were encountered with this regimen.
PMID- 10784636
TI - Profile of men randomized to the prostate cancer prevention trial: baseline
health-related quality of life, urinary and sexual functioning, and health
behaviors.
AB - PURPOSE: To describe men who agreed to be randomized to the Prostate Cancer
Prevention Trial (PCPT), a 7-year, double-blind placebo-controlled study of the
efficacy of finasteride in preventing prostate cancer. METHODS: Comprehensive
health-related quality-of-life data are presented for 18,882 randomized PCPT
participants. RESULTS: PCPT participants are highly educated, middle to upper
income, and primarily white (92%). Participants reported healthy lifestyles. The
mean American Urological Association Symptom Index score was well below the
maximum entry score of less than 19; existing urinary symptoms were generally not
bothersome. The scores for two sexual functioning scales could range from 0 to
100, with higher scores reflecting worse sexual functioning. The mean score for
the Sexual Problem Scale was 19.2 out of 100, and the mean Sexual Activities
Scale was 44.1 out of 100. Scores for seven of the eight Medical Outcomes Study
36-item Short-Form Health Survey scales (higher scores are better) were 10 to 20
points higher than those reported by a general population sample and differed
minimally by race but not by age. Previously reported associations between sexual
dysfunction and hypertension, diabetes, and depression were also observed. Men
who never smoked reported less sexual dysfunction than did those who either had
quit or still smoked. CONCLUSION: Individuals who are likely to enroll in primary
prevention trials have a high socioeconomic status, healthy lifestyle behaviors,
and better health than the general population. These data help oncologists design
chemoprevention trials with respect to the selection of health-related quality-of
life assessments and recruitment strategies.
PMID- 10784637
TI - Impact of the number of treatment courses on the clinical response of patients
who receive high-dose bolus interleukin-2.
AB - PURPOSE: To determine the impact of treatment with successive courses of high
dose bolus interleukin-2 (IL-2) on the incidence of clinical responses in
patients with metastatic melanoma or renal cell cancer. PATIENTS AND METHODS: A
consecutive series of 350 patients with either metastatic melanoma or renal cell
cancer who were treated with high-dose bolus IL-2 in the Surgery Branch, National
Cancer Institute, between September 1985 and November 1996 was analyzed, with a
median potential follow-up of 7.1 years. All patients were treated with 720,000
IU/kg of IL-2 administered by a 15-minute intravenous infusion every 8 hours for
up to 5 days, as clinically tolerated per cycle. Patients were retreated
according to clinical response and tolerance to the IL-2 therapy. RESULTS: Of the
149 patients with melanoma, 10 achieved complete responses (CRs) and 13 partial
responses (PRs), for an overall response rate of 15.4%. Of the 201 patients with
renal cell cancer, 18 achieved CRs and 20 PRs, for an overall response rate of
19.0%. Among responding patients, 21 of 23 with melanoma and 34 of 38 with renal
cell cancer developed at least PRs after the first course of IL-2. CONCLUSION:
Most patients with metastatic melanoma and renal cell cancer who achieved PRs or
CRs to intravenous high-dose bolus IL-2 were identified after the first course of
therapy. Those who demonstrated no response after two treatment courses failed to
respond to additional IL-2 therapy. Based on this retrospective analysis, we
recommend that patients who exhibit objective responses to treatment with high
dose bolus IL-2 receive additional treatment courses until either CR or IL-2
intolerance develops. Patients who do not achieve objective responses after two
courses of IL-2 should receive no further treatment with this regimen.
PMID- 10784638
TI - Dexamethasone for the prophylaxis of radiation-induced emesis: a National Cancer
Institute of Canada Clinical Trials Group phase III study.
AB - PURPOSE: To investigate the efficacy of dexamethasone as a prophylactic
antiemetic for patients receiving fractionated radiotherapy to the upper abdomen
in a randomized controlled trial. PATIENTS AND METHODS: One hundred fifty-four
patients planned to receive fractionated radiotherapy to fields involving the
upper abdomen (minimum total dose, 20 Gy; minimum number of fractions, five) were
randomized to receive prophylactic dexamethasone (2 mg orally three times a day
[tid], starting in the morning of first treatment and continuing until after
their fifth treatment) or placebo. The primary end point of the study was the
proportion of patients free from emesis during the study period. Secondary end
points included a quality-of-life assessment using the core questionnaire of the
European Organization for Research and Treatment of Cancer and side effects of
dexamethasone therapy in this population of patients. RESULTS: Fifty-four (70%)
out of 75 patients receiving dexamethasone had complete protection versus 37
(49%) out of 75 patients on placebo (P = .025). Most emetic episodes occurred
during the initial phase of treatment. Although there was no difference in global
quality of life between the two sets of patients, patients receiving
dexamethasone had less nausea and vomiting and less loss of appetite but more
insomnia. CONCLUSION: Dexamethasone 2 mg tid seems to be an effective
prophylactic antiemetic in this situation. Side effects were acceptable, but
there seemed to be no overall effect on global quality of life.
PMID- 10784639
TI - Biology of the adenomatous polyposis coli tumor suppressor.
AB - The adenomatous polyposis coli (APC) gene was first identified as the gene
mutated in an inherited syndrome of colon cancer predisposition known as familial
adenomatous polyposis coli (FAP). Mutation of APC is also found in 80% of all
colorectal adenomas and carcinomas and is one of the earliest mutations in colon
cancer progression. Similar to other tumor suppressor genes, both APC alleles are
inactivated by mutation in colon tumors, resulting in the loss of full-length
protein in tumor cells. The functional significance of altering APC is the
dysregulation of several physiologic processes that govern colonic epithelial
cell homeostasis, which include cell cycle progression, migration,
differentiation, and apoptosis. Roles for APC in some of these processes are in
large part attributable to its ability to regulate cytosolic levels of the
signaling molecule beta-catenin and to affect the transcriptional profile in
cells. This article summarizes numerous genetic, biochemical, and cell biologic
studies on the mechanisms of APC-mediated tumor suppression. Mouse models of FAP,
in which the APC gene has been genetically inactivated, have been particularly
useful in testing therapeutic and chemopreventive strategies. These data have
significant implications for colorectal cancer treatment approaches as well as
for understanding other disease genes and cancers of other tissue types.
PMID- 10784640
TI - Prophylactic surgery in women with a hereditary predisposition to breast and
ovarian cancer.
AB - PURPOSE: To review the published literature on the efficacy and adverse effects
of prophylactic mastectomy (PM) and prophylactic oophorectomy (PO) in women with
a hereditary predisposition to breast and ovarian cancer and to provide
management recommendations for these women. METHODS: Using the terms
"prophylactic," "preventive," "bilateral," "mastectomy," "oophorectomy," and
"ovariectomy," a MEDLINE search of the English-language literature for articles
related to PM and PO was performed. The bibliographies of these articles were
reviewed to identify additional relevant references. RESULTS: There have been no
prospective trials of PM or PO for the reduction of breast cancer or ovarian
cancer incidence or mortality. Most of the available retrospective studies are
composed of women who had surgery for a variety of indications and in whom
genetic risk was not well characterized. However, some reports in women at
increased risk of breast or ovarian cancer have shown that PM and PO can reduce
cancer incidence. CONCLUSION: Interest in and use of PM and PO are high among
physicians and high-risk women. PM and PO seem to be associated with considerable
reduction in the risk of breast and ovarian cancer, albeit incomplete. The
surgical morbidity of PM and PO is low, but the complications of premature
menopause may be significant, and few studies address quality-of-life issues in
women who have opted for PM and PO. Management recommendations for high-risk
individuals are presented on the basis of the available evidence.
PMID- 10784641
TI - Diagnosis in oncology. Case 1: primary transmural cardiac lymphoma.
PMID- 10784642
TI - Diagnosis in oncology. Case 2: secondary lymphoma of the heart manifesting as
intracavitary masses.
PMID- 10784643
TI - Spirituality and the dying patient.
PMID- 10784644
TI - Intrathecal cytarabine and bone marrow suppression.
PMID- 10784645
TI - Dexrazoxane and the ASCO guidelines for the use of chemotherapy and radiotherapy
protectants: a critique.
PMID- 10785212
TI - The ovarian hyperstimulation syndrome.
AB - OBJECTIVE: To review the up-to-date literature concerning the pathogenesis of,
risk factors for, prevention of, and therapy for the ovarian hyperstimulation
syndrome, and to provide suggestions for management of this syndrome. DESIGN:
Literature review combined with on-site clinical experiences at the authors'
institution of practice. PATIENT(S): Women who have risk factors for or manifest
the ovarian hyperstimulation syndrome. INTERVENTION(S): Intravenous fluid
management, thrombosis prevention techniques, paracentesis techniques, and
critical care management protocols. MAIN OUTCOME MEASURE(S): Staging system of
the ovarian hyperstimulation syndrome, criteria for outpatient versus
hospitalization management, and indications for varying levels of interventional
management. RESULT(S): The ovarian hyperstimulation syndrome, unique to the field
of assisted reproductive technology, remains a largely elusive and unpredictable
iatrogenic physiologic complication in the course of pharmacologic ovarian
stimulation. Reliable information on risk factors, possible physiologic
mechanisms, prevention techniques, and management is fortunately progressing, and
overall advances are being made in this field. The present review is an attempt
to summarize the modern literature regarding this syndrome and to use this
current knowledge to provide a basis for acceptable management regimens.
CONCLUSION(S): Ovarian hyperstimulation syndrome is a serious complication of
assisted reproductive technology, with potential for critical morbidity and
death. Physicians who prescribe medications known to be associated with this
syndrome should be familiar with identifiable risk factors, means of prevention,
and a system for staging and treating the disease and have a current knowledge
base for putative models of pathogenesis.
PMID- 10785213
TI - Round spermatid injection.
PMID- 10785214
TI - Distinction between early and late ovarian hyperstimulation syndrome.
AB - OBJECTIVE: To compare patient and cycle characteristics among three study groups:
early ovarian hyperstimulation syndrome (OHSS), late OHSS, and non-OHSS. DESIGN:
Prospective observational study. SETTING: University assisted conception service.
PATIENT(S): Women undergoing in vitro fertilization, intracytoplasmic sperm
injection or gamete intrafallopian transfer treatment at Bristol University In
Vitro Fertilization Service between January 1, 1995, and December 31, 1998.
INTERVENTION: None. MAIN OUTCOME MEASURE(S): Patient age, prevalence of
polycystic ovaries, gonadotropin requirement, peak serum estradiol (E(2))
concentration, number of oocytes retrieved, clinical pregnancy rate, number of
gestation sacs, and severity of OHSS. RESULT(S): Women with early OHSS had
significantly higher serum E(2) levels and lower gonadotropin requirements than
did the other groups. Cycles with either early or late OHSS had significantly
more oocytes collected than those without OHSS. Serum E(2) and oocyte numbers did
not accurately predict the risk of developing late OHSS. Clinical pregnancies
occurred in all cycles with late OHSS, and multiple pregnancies were
significantly more frequent in the late OHSS group than in the other groups. Late
OHSS was more likely than early OHSS to be severe. CONCLUSION(S): Early OHSS
relates to "excessive" preovulatory response to stimulation, whereas late OHSS
depends on the occurrence of pregnancy, is likelier to be severe, and is only
poorly related to preovulatory events.
PMID- 10785215
TI - A prospective, randomized controlled trial comparing the efficacy of recombinant
follicle-stimulating hormone in three different in vitro fertilization protocols.
AB - OBJECTIVE: To compare the following IVF protocols: a short protocol and long
protocols starting on day 2 or day 21. All protocols used recombinant FSH (rFSH)
for ovarian stimulation. DESIGN: Prospective, randomized study. SETTING: An
assisted reproduction unit at a university center. PATIENT(S): Patients
undergoing IVF (n = 150) were treated according to one of the three treatment
protocols allocated by a random method. INTERVENTION(S): All patients used
buserelin acetate and rFSH. Patients began the long protocol on day 2 (group 1)
or day 21 (group 2) of the cycle. Patients in group 3 began the short protocol on
day 2 of the cycle. MAIN OUTCOME MEASURE(S): Ovarian response, implantation
rates, and pregnancy rates (PRs). RESULT(S): Patients treated with the short
protocol (group 3) were stimulated in a shorter time, required less rFSH, and
achieved higher E(2) levels. The numbers of follicles, oocytes, and embryos were
similar in all three groups. The implantation rates were similar in groups 1 and
2 (11.8% and 13.3%, respectively), and both were higher than in group 3 (4.1%).
Clinical PRs per oocytes retrieved were 19.6%, 18.6%, and 8.3% in groups 1, 2,
and 3, respectively. CONCLUSION(S): The implantation rate was significantly
higher with the long protocols than with the short protocol, with a tendency for
a higher PR as well.
PMID- 10785216
TI - Tubal sterilization: focus on the U.S. experience.
AB - OBJECTIVE: To review the frequency, effectiveness, and clinical sequelae of tubal
sterilization with a focus on the U.S. experience. DESIGN: A review of U.S.
health care statistics and English-language literature using a MEDLINE search,
bibliographies of key references, and U.S. government publications. PATIENT(S):
Women seeking tubal sterilization. INTERVENTION: Tubal sterilization. MAIN
OUTCOME MEASURE(S): Effectiveness and long-term risks and benefits. RESULT(S):
Half of the 700,000 annual bilateral tubal sterilizations (TS) are performed
postpartum and half as ambulatory interval procedures. Eleven million U.S. women
15-44 years of age rely on TS for contraception. Failure rates vary by method
with one third or more resulting in ectopic pregnancy. Reversal is most
successful after use of methods that destroy the least tube. Evidence of
menstrual or hormonal disturbance after TS is weak, although some studies find
higher rates of hysterectomy among previously sterilized women. Decreased risk of
subsequent ovarian cancer has been observed among sterilized women.
CONCLUSION(S): Tubal sterilization is highly effective and safe. Failures,
although uncommon, occur at higher rates than previously appreciated. Evidence
for hormonal or menstrual changes due to TS is weak. Tubal sterilization is
associated with decreased risk of ovarian cancer.
PMID- 10785217
TI - Safety and effectiveness of vasectomy.
AB - OBJECTIVE: To recommend further research on vasectomy based on a systematic
review of the effectiveness and safety of vasectomy. DESIGN: A systematic MEDLINE
review of the literature on the safety and effectiveness of vasectomy between
1964 and 1998. MAIN OUTCOME MEASURE(S): Early failure rates are <1%; however,
effectiveness and complications vary with experience of surgeons and surgical
technique. Early complications, including hematoma, infection, sperm granulomas,
epididymitis-orchitis, and congestive epididymitis, occur in 1%-6% of men
undergoing vasectomy. Incidence of epididymal pain is poorly documented. Animal
and human data indicate that vasectomy does not increase atherosclerosis and that
increases in circulating immune complexes after vasectomy are transient in men
with vasectomies. The weight of the evidence regarding prostate and testicular
cancer suggests that men with vasectomy are not at increased risk of these
cancers. CONCLUSION(S): Publications to date continue to support the conclusion
that vasectomy is a highly effective form of contraception. Future studies should
include evaluations of the long-term effectiveness of vasectomy, evaluating
criteria for postvasectomy discontinuation of alternative contraception for use
in settings where semen analysis is not practical, and characterizing
complications including chronic epididymal pain syndrome.
PMID- 10785218
TI - Women, men, and contraceptive sterilization.
AB - OBJECTIVE: To review the social and behavior contexts of decisions about
contraceptive sterilization and to analyze factors associated with sterilization
choices. DESIGN: Multinomial logit regression of sterilization. PATIENT(S):
Various subsamples as appropriate to specific analyses drawn from the 10,847
women interviewed in the 1995 National Survey of Family Growth, and the 5,227 men
interviewed in the National Survey of Families and Households. INTERVENTION(S):
None. MAIN OUTCOME MEASURE(S): Tubal sterilization and vasectomy. RESULT(S):
Surprisingly high proportions of recent tubal sterilizations were performed on
unmarried women: 1 in 3 overall, 1 in 5 among white non-Hispanic women, and 2 in
3 among black women. Sterilization choice among continuously married couples also
revealed large differences by race and ethnicity. Parity at the time of the last
wanted birth is a major factor affecting sterilization choices, although
significant effects were found as well as for a number of other variables,
including age differences between spouses, education, and religion. Compared with
other regions, the ratio of tubal sterilizations to vasectomies is extremely low
in the Western region of the United States. CONCLUSION(S): Analysis of
sterilization decisions must be based on time since the completion of
childbearing. The findings call attention to the need for measuring variables
that mediate observed associations with sterilization outcomes.
PMID- 10785219
TI - Noninvasive assessment of glucose and pyruvate uptake by human embryos after
intracytoplasmic sperm injection and during the formation of pronuclei.
AB - OBJECTIVE: To improve in vitro culture conditions and human embryo selection
before transfer after IVF with intracytoplasmic sperm injection (ICSI). DESIGN: A
controlled, randomized, prospective study. SETTING: University hospital-based IVF
ET program. PATIENT(S): Couples undergoing ICSI. INTERVENTION(S): Culture of
human embryos in the presence of 1 mM or 5.56 mM glucose and metabolic
measurements with the use of noninvasive microfluorescence assays immediately
after ICSI to the time of transfer. MAIN OUTCOME MEASURE(S): Embryo development,
implantation rate, and glucose and pyruvate uptake. RESULT(S): Fertilization
rates, early embryo development, and implantation rates were not significantly
different between 1 mM and 5.56 mM glucose. Pyruvate uptake was significantly
higher during the formation of the pronuclei, at 15 +/- 0.7 and 11.4 +/- 1.3
pmol/embryo/h for fertilized and unfertilized oocytes, respectively. Pyruvate
uptake did not correlate with cleavage stage or embryo morphology. However,
during the second day of incubation, pyruvate uptake was significantly higher for
the untransferred embryos of pregnant women compared with nonpregnant women, at
17.9 +/- 1.5 and 10.8 +/- 1.0 pmol/embryo/h, respectively. CONCLUSION(S): The
increased level of pyruvate uptake during fertilization reflects the increased
demand for energy necessary for the formation of the pronuclei. However, the
metabolic measurements could not improve the selection of embryos with the best
implantation potential. Finally, the reduction of glucose concentration in the
culture medium failed to improve embryo viability.
PMID- 10785220
TI - In vitro fertilization outcomes after intracytoplasmic sperm injection with fresh
or frozen-thawed testicular spermatozoa.
AB - OBJECTIVE: To compare the outcomes of intracytoplasmic sperm injection (ICSI) and
in vitro fertilization (IVF) with fresh and cryopreserved testicular spermatozoa
in patients with obstructive and nonobstructive azoospermia. DESIGN:
Retrospective analysis of consecutive ICSI cycles. SETTING: Large urban
reproductive medicine program. PATIENT(S): Twenty-nine patients with obstructive
and nonobstructive azoospermia undergoing testicular sperm extraction for a total
of 46 IVF-ICSI cycles (12 fresh, 34 frozen). INTERVENTION(S): Testicular sperm
extraction, cryopreservation, and IVF-ICSI with fresh or frozen-thawed
spermatozoa. MAIN OUTCOME MEASURE(S): Fertilization rates, embryo cleavage rates,
embryo implantation rates, clinical pregnancy rates per cycle and per embryo
transfer, and delivery and spontaneous abortion rates. RESULT(S): No
statistically significant differences were noted in any of the parameters
examined between IVF-ICSI cycles from fresh or frozen-thawed testicular
spermatozoa. Fertilization rates were 56% with fresh vs. 61% with frozen-thawed
testicular sperm, cleavage rates 92% vs. 95%, implantation rates 26% vs. 17%,
clinical pregnancy rates per cycle 33% vs. 41%, and pregnancy rates per embryo
transfer 33% vs. 45%, respectively. Delivery rates were 75% with fresh vs. 69.2%
with frozen-thawed testicular sperm, and spontaneous abortion rates 25% and
30.8%, respectively. CONCLUSION(S): No differences were found in IVF-ICSI
outcomes between cryopreserved and fresh testicular sperm. In addition,
cryopreservation provides several advantages for the patients and reproductive
team.
PMID- 10785221
TI - Oxalate in human seminal plasma: possible significance and problems of oxalate
determination.
AB - OBJECTIVE: To determine the level of oxalate in seminal plasma and to correlate
it with andrologic variables. DESIGN: Laboratory examination. SETTING: University
based department of andrology and department of clinical chemistry. PATIENT(S):
One hundred male outpatients with infertility. INTERVENTION(S): Isolated seminal
plasma was stored for 120 days at -20 degrees C. MAIN OUTCOME MEASURE(S): Levels
of oxalic acid in seminal plasma. RESULT(S): Oxalate levels in seminal plasma
depend on the degradation of ascorbic acid to oxalic acid during storage. There
was a linear nonenzymatic increase of oxalate with storage time. After 120 days
of storage, the values were 133 +/- 50 micromol/L (n = 100). Oxalic acid
correlated significantly with the number of sperm head anomalies, the pH value,
and the age of the donors and correlated negatively with the volume of ejaculate.
CONCLUSION(S): Oxalic acid in seminal plasma may influence male fertility.
PMID- 10785222
TI - Expression of the platelet-activating factor receptor in human spermatozoa:
differences in messenger ribonucleic acid content and protein distribution
between normal and abnormal spermatozoa.
AB - OBJECTIVE: To determine the expression and distribution of the platelet
activating factor (PAF) receptor in normal and abnormal specimens of human
spermatozoa. DESIGN: Prospective analysis of membrane-bound PAF receptors by
immunofluorescence and PAF receptor messenger RNA by quantitated reverse
transcription-polymerase chain reaction in normal and abnormal spermatozoa.
SETTING: University-based reproductive genetics laboratory. PATIENT(S): Men
undergoing routine semen analysis. INTERVENTION(S): Normal and abnormal
spermatozoa were exposed to rabbit anti-PAF receptor antibody, fluorescein
isothiocyanate-conjugated goat anti-rabbit antibody, and fluorescent microscopy
or subjected to RNA isolation by acid-phenol extraction and quantitated (MIMIC
Construction Kit [Clontech Laboratories, Inc., Palo Alto, CA]) reverse
transcription-polymerase chain reaction. MAIN OUTCOME MEASURE(S): Fluorescent
intensities at six locations along spermatozoa (end piece, principal tail,
midpiece, neck, proximal head, and acrosomal region) and PAF receptor expression
(messenger RNA) levels. RESULT(S): Immunofluorescence demonstrated a significant
difference in PAF receptor distribution between normal and abnormal human
spermatozoa, specifically at the neck region. Additionally, abnormal spermatozoa
were found to have statistically significantly more PAF receptor messenger RNA
than normal spermatozoa. CONCLUSION(S): Platelet-activating factor receptor
expression and distribution are significantly altered in abnormal spermatozoa and
this may be the result of some defect in gene transcription.
PMID- 10785223
TI - Serum levels of inhibins are differentially altered in patients with polycystic
ovary syndrome: effects of being overweight and relevance to hyperandrogenism.
AB - OBJECTIVE: To explore the abnormalities of serum inhibin isoform concentrations
in a large group of patients with polycystic ovary syndrome (PCOS) and to
evaluate the influence of body mass index (BMI), age, LH, and androgens on serum
inhibin levels. DESIGN: Prospective study. SETTING: Reproductive endocrinology
unit of an academic medical center. PATIENT(S): Forty-one women with PCOS were
compared with 24 healthy women. INTERVENTION(S): Blood sampling was performed in
the early follicular phase in patients and in control women. MAIN OUTCOME
MEASURE(S): Serum levels of inhibin A, inhibin B, alpha-inhibin, pro-alphaC
(alpha-inhibin precursor proteins), LH, FSH, E(2), T, and androstenedione (A)
were assessed in all subjects. RESULT(S): Serum alpha-inhibin levels together
with LH, T, and A levels were significantly increased in women with PCOS. Serum
inhibin A levels were lower in patients with PCOS than controls (median +/- SD:
7.35 +/- 2.9 vs. 9.4 +/- 4.7 pg/mL), pro-alphaC levels were higher (264 +/- 136.7
vs. 127 +/- 81.5 pg/mL), and inhibin B levels did not differ between the groups
(110.5 +/- 51.5 vs. 108 +/- 47.5 pg/mL). Simple regression analysis showed that
inhibin A and B levels were negatively correlated with BMI in patients with PCOS
(r = -0.43 and r27 kg/m(2)) displayed significantly lower inhibin A and inhibin B
levels and a higher pro-alphaC-inhibin A ratio than nonobese patients with PCOS
(BMI =27 kg/m(2)). In this last subgroup, the mean inhibin B level was
significantly higher than in controls (median +/- SD: 144 +/- 53.5 vs. 108 +/-
47.5 pg/mL). Partial regression analysis, after controlling for age and BMI,
demonstrated that in patients with PCOS, pro-alphaC levels were positively and
independently correlated with LH and A levels. CONCLUSION(S): Among women with
PCOS, the trend toward an excess serum inhibin B level is observed exclusively in
nonobese patients. The higher pro-alphaC levels and the lower inhibin A levels
might reflect a defect in the processing of inhibins specific to polycystic
ovaries. In addition, our data suggest that pro-alphaC originates from the theca
interstitial cells and could participate in control of the androgen production by
these cells.
PMID- 10785224
TI - Pregnancies and deliveries after in vitro maturation culture followed by in vitro
fertilization and embryo transfer without stimulation in women with polycystic
ovary syndrome.
AB - OBJECTIVE: To improve the efficacy of an IVF-ET program for unstimulated patients
with polycystic ovary syndrome (PCOS) with the use of culture for oocyte
maturation. DESIGN: Prospective studies with the comparison of different ET
procedures from March 1995 through February 1998. SETTING: University-affiliated
hospital. PATIENT(S): Ninety-four cycles in 64 consenting patients with PCOS.
INTERVENTION(S): Immature oocytes were retrieved from unstimulated patients with
PCOS and subsequently cultured and fertilized in vitro. Zygote intrafallopian
transfer (ZIFT), uterine ET, or a combined approach of ZIFT + uterine ET was
subsequently performed. MAIN OUTCOME MEASURE(S): Laboratory and clinical data.
RESULT(S): Among 1, 280 immature oocytes (13.6 +/- 7.5 oocytes per patient)
retrieved, 89% (1,139) were morphologically normal, and 62.2% (708/1,139) of the
normal oocytes matured in vitro after culture for 48 hours. When intracytoplasmic
sperm injection was performed, 68% (481/708) developed to the normal pronuclear
stage, and 88.1% of the embryos cocultured with Vero cells (266/302) cleaved.
Eighty-five ET cycles were conducted and pregnancy was established in 23 cycles
(27.1%), which consisted of 8 after uterine ET and 15 after a combined approach.
Seventeen patients delivered 20 normal infants. CONCLUSION(S): The IVF-ET method
using no ovarian stimulation followed by in vitro maturation culture can be a
feasible assisted reproductive technology for treatment of PCOS with various
complications.
PMID- 10785225
TI - A prospective, randomized trial comparing flutamide (250 mg/d) and finasteride (5
mg/d) in the treatment of hirsutism.
AB - OBJECTIVE: To compare the long-term (1 year) effects of flutamide (250 mg/d) and
finasteride (5 mg/d) for the treatment of hirsutism in women. DESIGN: Randomized,
prospective clinical study. SETTING: Departments of Gynecology and Obstetrics and
Endocrinology at Erciyes University Medical Faculty, Kayseri, Turkey. PATIENT(S):
Seventy patients with hirsutism were studied. INTERVENTION(S): Thirty-five
patients were treated with flutamide (250 mg/d) and 35 patients with finasteride
(5 mg/d) for 12 months. Hirsutism score, hormone levels, and multiscreen blood
chemistry were measured at 3-month intervals. MAIN OUTCOME MEASURE(S): Reduction
in hair growth. RESULT(S): The modified Ferriman-Gallwey scores for hirsutism
decreased significantly at months 6 and 12 from a mean +/- SD of 17. 8 +/- 5.8 to
6.0 +/- 3.4 and 17.8 +/- 5.8 to 4.8 +/- 3.2, respectively, in group 1; and from
19.1 +/- 6.1 to 14.2 +/- 4.9 and 19.1 +/- 6.1 to 11.3 +/- 5.0 in group 2,
respectively. There were no statistically significant differences in any of the
hormonal indices in group 1, but in group 2, E(2) and sex hormone-binding
globulin increased significantly while DHEAS decreased significantly at 12 months
of therapy. CONCLUSION(S): This study shows that flutamide (250 mg/d) is more
effective than finasteride (5 mg/d) in reducing hair growth. We conclude that
flutamide (250 mg/d) may represent a more effective and well tolerated treatment
for patients.
PMID- 10785226
TI - Identification of macrophages at the site of peritoneal injury: evidence
supporting a direct role for peritoneal macrophages in healing injured
peritoneum.
AB - OBJECTIVE: To determine if peritoneal macrophages are present at the site of a
surgical injury to the peritoneum during wound healing. DESIGN: Controlled
research study. SETTING: Academic research laboratory. EXPERIMENTAL MODEL: A
murine model of peritoneal wound healing. INTERVENTION(S): Intraperitoneal
injection of polystyrene beads 1 hour after a surgical peritoneal injury to
identify peritoneal macrophages. MAIN OUTCOME MEASURE(S): Presence of peritoneal
macrophages at the site of the healing wound as determined by intracellular
polystyrene beads on transmission electron microscopy 1, 3, 7, and 14 days after
injury. RESULT(S): Peritoneal macrophages were easily distinguished from other
cell types by the phagocytosis of polystyrene beads. One day after injury,
peritoneal macrophages were adherent to the wound surface. By 3 days, mesothelial
cells began covering the peritoneal macrophages at the wound surface and
peritoneal macrophages were identified deep within the wound. Seven days after
injury, the mesothelial layer was completely reconstituted, but peritoneal
macrophages persisted within the healing would below the surface mesothelium.
CONCLUSION(S): These data indicate that peritoneal macrophages are present at the
peritoneal injury site throughout the healing interval and are consistent with
these macrophages having a critical role in peritoneal wound healing.
PMID- 10785227
TI - Insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and IGFBP-3
protease activity in the peritoneal fluid of patients with and without
endometriosis.
AB - OBJECTIVE: To compare levels of insulin-like growth factor (IGF) components in
the peritoneal fluid of patients with and without endometriosis. DESIGN: Patients
with endometriosis were compared with control patients. SETTING: Seoul National
University Hospital, Korea. PATIENT(S): Forty-three patients with endometriosis
and 20 patients without endometriosis. INTERVENTION(S): Peritoneal fluid
specimens were collected. MAIN OUTCOME MEASURE(S): Insulin-like growth factors,
IGF binding protein (IGFBP) profiles and IGFBP-3 protease activity. RESULT(S):
The IGF-I levels in peritoneal fluid were significantly higher in patients with
endometriosis than in control patients, while the IGFBP-3 levels and the relative
proportion of IGFBP-2 in peritoneal fluid were significantly lower in patients
with endometriosis than in control patients. However, IGF-II levels, IGFBP-4
profiles, and IGFBP-3 protease activity did not differ significantly between the
two groups. No correlation between these IGF components in peritoneal fluid and
the stage of endometriosis was noted. CONCLUSION(S): The profiles of IGF
components in peritoneal fluid of patients with pelvic endometriosis may play an
important role in the growth of ectopic endometrium and endometriosis-induced
infertility.
PMID- 10785228
TI - Mitochondrial ATPase 6 gene expression in unfertilized oocytes and cleavage-stage
embryos.
AB - OBJECTIVE: To compare the level of mitochondrial ATPase 6 gene expression in
unfertilized oocytes and cleavage-stage embryos. DESIGN: Reverse transcription
polymerase chain reaction was performed in unfertilized oocytes and cleavage
stage embryos derived from tripronucleate embryos to determine ATPase 6 gene
expression. SETTING: Department of Obstetrics and Gynecology, Human Genetics
Laboratory, Infertility Medical Center of CHA General Hospital, College of
Medicine, Pochon CHA University, Seoul, Korea. PATIENT(S): Oocytes were obtained
from infertile couples undergoing in vitro fertilization. INTERVENTION(S):
Unfertilized oocytes collected at 48 hours after retrieval and cleavage-stage
embryos derived from tripronucleate embryos were prepared for evaluation of
mitochondrial gene expression. MAIN OUTCOME MEASURE(S): Comparison of ATPase 6
gene expression by using single-cell reverse transcription polymerase chain
reaction. RESULT(S): Expression of unfertilized oocytes decreased compared with
early cleavage-stage embryos. CONCLUSION(S): Our findings of decreased ATPase 6
expression in unfertilized oocytes suggest that there may be a decrease in the
mitochondrial functional capacity of oxidative phosphorylation.
PMID- 10785229
TI - Transforming growth factor-beta3 is expressed at high levels in leiomyoma where
it stimulates fibronectin expression and cell proliferation.
AB - OBJECTIVE: To investigate the expression of TGF-beta3 in leiomyoma and myometrium
as well as the effect of TGF-beta3 on the expression of fibronectin and on the
proliferation of leiomyoma and myometrial cells. DESIGN: Observational and in
vitro experimental study. SETTING: University medical center. PATIENT(S): Women
with (n = 18) leiomyoma. INTERVENTION(S): First TGF-beta3 mRNA and protein levels
in myometrium and leiomyoma were measured, and then myometrial and leiomyoma
cells in culture were treated with TGF-beta3. MAIN OUTCOME MEASURE(S): TGF-beta3
and fibronectin mRNA were evaluated by Northern analysis. Myometrial and
leiomyoma cell proliferation was assessed with use of [(3)H]thymidine
incorporation. RESULT(S): The TGF-beta3 mRNA level in the leiomyoma samples was
3.5-fold higher than in the myometrial samples. The highest TGF-beta3 mRNA level
was observed in leiomyoma samples from midsecretory phase and was 5-fold higher
than in proliferative phase samples. Fibronectin mRNA expression also was higher
in the leiomyoma than in the myometrium. TGF-beta3 induced fibronectin expression
in leiomyoma cells and directly stimulated myometrial and leiomyoma cell
proliferation in cultures. CONCLUSION(S): These findings suggest that TGF-beta3
may be mediating the growth-promoting effects of sex steroids on leiomyomas by
playing a role in the fibrogenic process and cell proliferation that characterize
these tumors.
PMID- 10785230
TI - Retinoic acid suppresses interleukin-6 production in human endometrial cells.
AB - OBJECTIVE: To determine whether retinoic acid (RA) can regulate the expression of
interleukin (IL)-6 in human endometrial cells in a manner that might be
beneficial to women with endometriosis. DESIGN: In vitro study. SETTING: Academic
medical center. PATIENT(S): Patients with endometriosis and controls.
INTERVENTION(S): Endometrial cell cultures were treated with RA. MAIN OUTCOME
MEASURE(S): Interleukin-6 protein secretion, messenger RNA expression, and IL-6
promoter activity. RESULT(S): Using a human endometrial cell line (EM42), as well
as primary stromal and epithelial endometrial cells, we demonstrated that RA
suppresses IL-6 protein and messenger RNA expression in a time- and dose
dependent fashion, showing maximal effects at pharmacologically achievable blood
serum concentrations (micromoles per liter). Retinoic acid specifically inhibited
the activity of IL-6-promoter reporter constructs that were transiently
transfected into EM42 cells. Mutational analysis of reporter constructs indicated
that RA suppression of IL-6 expression was mediated, at least in part, through
the nuclear factor IL-6 binding site located in the IL-6 promoter. CONCLUSION:
Retinoids may play a fundamental role in altering the pathophysiology of
endometriosis related to aberrant production of IL-6.
PMID- 10785231
TI - Induction of endometrial plasminogen activator-inhibitor 1: a possible mechanism
contributing to the effect of intrauterine levonorgestrel in the treatment of
menorrhagia.
AB - OBJECTIVE: To elucidate molecular mechanisms accounting for excessive menstrual
blood loss, and to present the therapeutic effect of an intrauterine
levonorgestrel system (LNG-IUS) in menorrhagia. DESIGN: A multicenter study
comparing hysterectomy with the LNG-IUS in treating menorrhagia. SETTING: A
university hospital. PATIENT(S): Women with (n = 27) and without (n = 14)
menorrhagia, and women with uterine fibroids but undetermined menstrual blood
loss (n = 35). INTERVENTION(S): An LNG-IUS was inserted into the uterine cavity
in 11 women with menorrhagia and six women experiencing normal menstrual blood
loss. MAIN OUTCOME MEASURE(S): Expression of the messenger ribonucleic acid
(mRNA) of tissue-type plasminogen activator (t-PA) and that of a specific PA
inhibitor type 1 (PAI-1) in endometrial tissue samples, as evaluated with the use
of Northern blot analysis. RESULT(S): t-PA mRNA was expressed in the endometrium
throughout the menstrual cycle, with no statistically significant difference
between a proliferative (n = 30) and a secretory endometrium (n = 40), or between
women experiencing normal menstrual blood loss (n = 14) and those with
menorrhagia (n = 27). The levels of t-PA mRNA in menstrual phase samples (n = 6)
were significantly higher than those in proliferative or secretory endometrium.
PAI-1 mRNA was detected in the endometrium during menstruation only. Both t-PA
mRNA and PAI-1 mRNA were expressed in all endometrial samples (n = 17) obtained 6
months after an LNG-IUS was inserted, regardless of the menstrual cycle phase.
The relative levels of both types of mRNA were significantly higher in LNG
endometrium than in proliferative or secretory endometrium, but levels did not
differ from those in menstrual-phase endometrium. CONCLUSION(S): The mean (+/-SD)
levels of t-PA mRNA and PAI-1 mRNA in the endometrium of women with and without
menorrhagia did not differ, suggesting that the PA system is not the major
determinant of menstrual blood loss. However, continuous induction of PAI-1 may
contribute to the therapeutic effect of LNG-IUS in treating menorrhagia.
PMID- 10785232
TI - Genetic contributions of the endothelial nitric oxide synthase gene to ovulation
and menopause in a mouse model.
AB - OBJECTIVE: To investigate the influence of the endothelial nitric oxide synthase
gene (Nos3) on ovulatory capacity and reproductive senescence. DESIGN:
Prospective, controlled study. SETTING: Academic research institution.
SUBJECT(S): Laboratory mice with targeted mutagenesis of Nos3. INTERVENTION(S):
Hyperstimulation protocol, oocyte culture, and ovarian histology using wild-type
(Nos3(+/+); n = 20), heterozygous (Nos3(+/m); n = 39), and homozygous deficient
(Nos3(m/m); n = 11) female mice; observation of reproductive outcomes. MAIN
OUTCOME MEASURE(S): Number and survival of oocytes; onset of menarche and
menopause. RESULT(S): The mean number of superovulated oocytes (18 +/- 36 vs. 41
+/- 4) and the 48-hour overall survival rate of embryos (65% vs. 81%) were
significantly reduced for Nos3(m/m) female mice compared with Nos3(+/+) female
mice. Nos3(m/m) females showed a significantly reduced number and size of antral
follicles and corpora lutea compared with wild-type controls. Compared with
Nos3(+/m) x Nos3(+/m) breedings, Nos3(m/m) x Nos3(m/m) breedings showed a higher
female age at first litter (76.2 +/- 10.3 vs. 107.8 +/- 26.6 days), fewer litters
(10.5 +/- 3.6 vs. 7. 8 +/- 4.2), and a lower female age at reproductive
senescence (400.2 +/- 64.5 vs. 332.1 +/- 27.4 days), respectively. CONCLUSION(S):
Our data suggest that Nos3 deficiency is associated with reduced ovulatory
capacity and impaired early embryonic viability and that it influences the onset
of menarche and menopause.
PMID- 10785233
TI - Outpatient evaluation and treatment of tubal obstruction with selective
salpingography and balloon tuboplasty.
AB - OBJECTIVE: To compare selective salpingography and balloon tuboplasty for the
treatment of tubal obstruction. DESIGN: A retrospective evaluation of results of
women treated for tubal obstruction by outpatient methods at a single center.
SETTING: Tertiary-care, university-affiliated hospital. PATIENT(S): A total of
3,424 infertile women, of whom 418 had bilateral tubal obstruction by
hysterosalpingography, treated at Nihon Medical Center from 1982 to 1997.
INTERVENTION(S): Women with tubal obstructions who had visual evidence of an
intact uterine tubal ostium at hysteroscopy were treated by selective
salpingography. If selective salpingography could not establish patency, then
transcervical balloon tuboplasty was performed with one of three catheter
systems. Patients were followed expectantly for 1 year after treatment. MAIN
OUTCOME MEASURE(S): Postoperative tubal patency and overall pregnancy rates (PRs)
at 1-year of follow-up. RESULT(S): The overall patency rate was 67.5%, with 30%
of these patients conceiving (20.2% of all subjects). Selective salpingography
was associated with a 35. 7% patency rate, and 27.3% of these patients conceived.
Of the subjects who failed selective salpingography and underwent balloon
tuboplasty, 66.2% achieved patency, of whom 33% spontaneously conceived. Balloon
tuboplasty was effective in restoring patency in many cases after selective
salpingography had failed. Statistically significant differences were found
between selective salpingography and balloon tuboplasty and for the different
balloon tuboplasty catheters in terms of patency rates, while a trend was seen
for PRs. CONCLUSION(S): Many women diagnosed as having tubal obstruction can be
treated by outpatient methods that do not require general anesthesia. Achieving
patency by these methods is associated with high PRs and avoids the need for
assisted reproductive technologies in some cases. Balloon tuboplasty is a more
effective treatment than selective salpingography. The choice of balloon
tuboplasty catheter system may affect success rates.
PMID- 10785234
TI - A second hysterosalpingography reduces the use of selective technique for
treatment of a proximal tubal obstruction.
AB - OBJECTIVE: To assess whether a second hysterosalpingography (HSG) can permit
tubal patency, reducing the use of selective salpingography in patients with
proximal tubal obstruction. DESIGN: Prospective study. SETTING: University
hospital. PATIENT(S): The study population consisted of 360 infertile women.
INTERVENTION(S): In patients with unilateral or bilateral proximal tubal
obstruction, a second HSG was performed after about 1 month. In those cases with
persistent obstruction, an immediate selective salpingography and tubal
catheterization were performed. MAIN OUTCOME MEASURE(S): Tubal opacification.
RESULT(S): Forty patients underwent a second HSG procedure for proximal tubal
occlusion. Among these, 24 achieved bilateral tubal patency. Thus, repetition of
a conventional HSG after 1 month avoided unnecessary salpingography in 60% of
patients. CONCLUSION(S): In infertile women with proximal tubal obstruction, we
believe it is best to perform a second HSG. HSG is easy to carry out and subjects
patients to a lower dosage of radiation and fewer risks than selective
salpingography. The latter technique should be reserved for unsuccessful cases.
PMID- 10785235
TI - Robotic-assisted laparoscopic microsurgical tubal anastomosis: a human pilot
study.
AB - OBJECTIVE: To evaluate the feasibility and safety of a robotic device to perform
a laparoscopic tubal anastomosis. DESIGN: Prospective pilot study. SETTING:
Tertiary care medical center. PATIENT(S): Ten patients with previous tubal
ligations underwent laparoscopic tubal ligation reversal using a robotic suturing
device. INTERVENTION(S): Tubal surgery was performed with a robotic system. A two
layered closure was used for all tubes. Four stitches of 8-0 polygalactin sutures
were used for each layer. MAIN OUTCOME MEASURE(S): Tubal patency; secondary
measures were pregnancy rates, complications, and operative time. RESULT(S): The
procedure was completed successfully in all 10 patients. No patient required
conversion to an open procedure. The mean time (+/-SD) required to complete the
anastomosis of both tubes was 159 +/- 33.8 minutes. Chromotubation at the end of
the procedure showed patency in all tubes anastomosed. A postoperative
hysterosalpingogram 6 weeks after surgery demonstrated patency in 17 of the 19
(89%) tubes anastomosed. There have been five pregnancies so far. There were no
complications. CONCLUSION(S): Robotic technology can be used safely to create
laparoscopic microsurgical anastomoses with adequate patency rates. Robotic
technology has the potential to make laparoscopic microsuturing easier.
PMID- 10785236
TI - Deep endometriosis conundrum: evidence in favor of a peritoneal origin.
AB - OBJECTIVE: To determine whether the depth and volume of the pouch of Douglas
differs in patients with endometriosis with and without deep lesions and to
compare them with subjects with a healthy pelvis or with diseases other than
endometriosis. DESIGN: Prospective, comparative study. SETTING: Tertiary care and
referral center for patients with endometriosis. PATIENT(S): Women undergoing
laparoscopy for infertility, pelvic pain, or adnexal anomalies (deep
endometriotic rectovaginal lesions in 16 cases, endometriosis without deep
lesions in 127 cases, miscellaneous anomalies in 35 cases, and normal pelvis in
26 cases). INTERVENTION(S): Douglas pouch depth measurement from the upper border
of uterosacral ligaments to its base with a calibrated probe and volume
assessment by a fluid-filling technique. MAIN OUTCOME MEASURE(S): Douglas pouch
depth and volume. RESULT(S): Mean (+/-SD) Douglas pouch depth and volume
measurements were 3.6 +/- 1.6 cm and 41.6 +/- 19.3 mL in women with deep
endometriosis, 5.3 +/- 0.8 cm and 67.2 +/- 18.1 mL in those with peritoneal and
ovarian lesions only, 5.2 +/- 0.9 cm and 67.6 +/- 12.6 mL in those with
miscellaneous conditions, and 5.5 +/- 0.8 cm and 65.8 +/- 10.9 mL in those with
normal pelvis. CONCLUSION(S): Reduced Douglas pouch depth and volume in women
with deep endometriosis suggest that such lesions develop not in the rectovaginal
septum but intraperitoneally and that burial by anterior rectal wall adhesions
creates a false bottom, giving an erroneous impression of extraperitoneal origin.
PMID- 10785237
TI - Usefulness of Doppler sonography in the diagnosis of ovarian torsion.
AB - OBJECTIVE: To assess the predictive value of Doppler sonography in the diagnosis
of ovarian torsion and to correlate Doppler results with surgical findings and
various clinical characteristics. DESIGN: Retrospective study of discharged
inpatients. SETTING: An academic community hospital. PATIENT(S): Twenty-one
patients with surgically confirmed ovarian torsion over an 8-year period.
INTERVENTION(S): Data were collected on Doppler flow results, ultrasound and
surgical findings, patient characteristics, and associated morbidity. MAIN
OUTCOME MEASURE(S): Accuracy of Doppler diagnosis as to presence of ovarian
torsion. RESULT(S): Twenty-one patients had surgically confirmed ovarian torsion.
Doppler sonography was performed in 10 of the 21 patients. Doppler sonographic
findings were normal in 60% (6 of 10), and abnormal (decreased or absent) in 40%
suggestive of torsion. In cases involving ovulation induction, Doppler sonography
findings were normal in 25% (1 of 4). Furthermore, the time to diagnosis of
ovarian torsion (mean = 5.3 hours) and the time to hospital discharge (mean = 2
days) were both decreased when compared with instances when normal flow was
detected by Doppler sonography (59 hours and 2.7 days, respectively).
CONCLUSION(S): Abnormal flow detected by Doppler sonography is highly predictive
of adnexal torsion and is therefore useful in the diagnosis of ovarian torsion.
However, when normal flow is detected by Doppler sonography, it does not
necessarily exclude an ovarian torsion; in fact, torsion is missed in 60% of
cases, and time to diagnosis in these cases is delayed. In cases of ovulation
induction, sensitivity is increased to 75%.
PMID- 10785238
TI - A pilot study involving minimal ovarian stimulation for in vitro fertilization:
extending the "follicle-stimulating hormone window" combined with the
gonadotropin-releasing hormone antagonist cetrorelix.
AB - OBJECTIVE: To study whether minimal interference in the process of selection of
the single dominant follicle may serve as the basis for a simplified ovarian
stimulation regimen for IVF. DESIGN: Single-center randomized pilot study.
SETTING: Tertiary referral fertility center. PATIENT(S): Fifteen normo-ovulatory
patients with a regular indication for IVF. INTERVENTION(S): Ovarian stimulation
for IVF was begun with 100 or 150 IU/d recombinant FSH starting on cycle day 5.
From cycle day 8 or later, cotreatment was begun with 0.25 mg/d GnRH antagonist.
No luteal support was provided. MAIN OUTCOME MEASURE(S): Total number of dominant
follicles and characteristics of the endocrine cycle. RESULT(S): Multiple
follicle development occurred in five of eight patients in the 100-IU group and
in all seven women in the 150-IU group. Follicular phase and luteal phase lengths
were normal, but the endocrine profile was abnormal. CONCLUSION(S): A fixed daily
dose of 150 IU recombinant FSH starting in the midfollicular phase resulted in
ongoing growth of a restricted number of dominant follicles and sufficient
oocytes retrieved to lead to ET. A marked reduction in the total amount of
gonadotropins administered compared with standard treatment was achieved.
Withholding luteal support did not exclude pregnancies.
PMID- 10785239
TI - A comparative study of high fixed-dose and decremental-dose regimens of
gonadotropins in a minidose gonadotropin-releasing hormone agonist flare protocol
for poor responders.
PMID- 10785240
TI - Successful pregnancy and delivery after in vitro fertilization and embryo
transfer in a patient with primary hypopituitarism.
PMID- 10785241
TI - A case of ovarian hyperstimulation during pituitary down-regulation caused by
plurihormonal macroadenoma.
PMID- 10785242
TI - Treatment of infertile women with adenomyosis with a conservative microsurgical
technique and a gonadotropin-releasing hormone agonist.
PMID- 10785244
TI - Reply from authors:
PMID- 10785243
TI - Is aspirin all it is cracked up to be-reproducibility of transvaginal color
Doppler ultrasonography for ovarian and uterine vessels?
PMID- 10785245
TI - What is the threshold value for serum estradiol levels associated with adverse
IVF outcomes?
PMID- 10785246
TI - Reply of the authors:
PMID- 10785248
TI - CDC announcement
PMID- 10785249
TI - Multiple system atrophy: the crime and the suspect.
PMID- 10785250
TI - Differentiation of Parkinson's disease and multiple system atrophy in early
disease stages by means of I-123-MIBG-SPECT.
AB - BACKGROUND: Differential diagnosis between idiopathic Parkinson's disease (PD)
and multiple system atrophy (MSA) is often difficult in early disease stages.
Since MSA is misdiagnosed as PD in more than 20% of the early stages, there is
need for methods refining the differentiation of the two disease entities. In PD
postganglionic involvement of the autonomic nervous system (ANS) predominates
whereas in MSA the ANS is mainly affected in its preganglionic structures. The
functional integrity of postganglionic cardiac sympathetic neurons can be
investigated using I-123-metaiodobenzylguanidine-single photon emission computed
tomography (MIBG-SPECT). OBJECTIVES: We investigated whether I-123-MIBG-SPECT
allows to differentiate between early stages of PD and MSA in patients not yet
requiring L-dopa therapy. METHODS: Thirty patients (10 PD and 20 MSA patients)
underwent MIBG-SPECT and evaluation of heart rate variability (HRV). Patients on
any medication interfering with MIBG-accumulation were excluded from the study.
Cardiac perfusion was evaluated by myocardial scintigraphy. RESULTS: The median
cardiac MIBG uptake was significantly decreased in PD as well as MSA patients
compared to controls (P<0.001). However, in the PD group MIBG uptake was
significantly lower than in MSA (P=0.03). Even in PD patients without clinical
signs of autonomic failure, MIBG uptake was significantly lower than in MSA
patients (P=0.03). Analysis of heart rate parameters did not differentiate
between PD and MSA patients. The median coefficient of variation was
significantly smaller in PD and MSA patients compared to control subjects.
CONCLUSIONS: Our study shows that MIBG-SPECT identifies autonomic cardiac
dysfunction in very early stages of both, PD and MSA. More importantly, the
technique facilitates differentiation of MSA and PD in the early stages. The
different pathology with prominent peripheral, postganglionic sympathetic
dysfunction in PD and primarily central and preganglionic lesions in MSA accounts
for a lower MIBG uptake in PD compared to MSA patients.
PMID- 10785251
TI - Regional differences of cerebrovascular reactivity effected by calcium channel
blocker - dotarizine.
AB - Dotarizine, a novel antimigraine prophylactic drug, is chemically related to
Diphenylbutylpiperazines, which are known to have Ca(2+)-antagonistic, alpha
adrenolytic and antihistaminic properties. Additionally, Dotarizine exhibits
strong 5-HT2 receptor-specific antiserotoninergic properties. The vasostabilizing
effect of Dotarizine on cerebrovascular reactivity during different ventilation
conditions was demonstrated in various in vitro and in vivo studies. In the
presented study, the effect of chronic oral administration of the drug on
vascular reactions of different areas of cerebral vessels following
hyperventilation was investigated. The experiments were carried out on two groups
of experimental animals (rabbits). In the first group (6) 25 mg/kg of Dotarizine
dissolved in 0.25% agar was administered orally for 5 days twice daily. The
control group of animals (6) was fed with agar of the same concentration
according to the same time schedule. During the experiment, 15 min
hyperventilation was performed and blood flow velocity (BFV) in the middle
cerebral artery (MCA) and the basilar artery (BA) was recorded using Transcranial
Doppler apparatus (TCD) before and after hyperventilation state. The obtained
results revealed a strong antivasoconstrictive effect of Dotarizine on cerebral
vessels reactivity during hyperventilation. In the control experimental group,
the 15 min hyperventilation caused a decrease in the mean BFV in MCA and BA by 36
and 14%, respectively, and in the drug-treated group under the same ventilation
conditions the decrease of the mean BFV in BA was only 6% and even a slight
increase (8% as compared with control values) of BFV in MCA was observed.
Comparison of the pulsatility index (PI) values demonstrated a significant
decrease of vascular resistance in MCA in the Dotarizine-treated group of animals
(P<0.1). From the obtained results it can be concluded that chronic oral
administration of a novel compound (Dotarizine) diminishes the vasoconstrictive
effect of hyperventilation on cerebral vessels in rabbits. The influence of this
drug demonstrates regional differences in the cerebrovascular reactivity and it
appears to change the vascular resistance in the small arteries of the
cerebrovascular system. Thus, it can be recommended as a good prophylactic
antimigraine compound due its vasostabilizing properties.
PMID- 10785252
TI - Cortical language lateralization in right handed normal subjects using functional
magnetic resonance imaging.
AB - In 95% of right handed individuals the left hemisphere is dominant for speech and
language function. The evidence for this is accumulated primarily from clinical
populations. We investigated cortical topography of language function and
lateralization in a sample of the right handed population using functional
magnetic resonance imaging and two lexical-semantic paradigms. Activated cortical
language networks were assessed topographically and quantitatively by using a
lateralization index. As a group, we observed left hemispheric language
dominance. Individually, the lateralization index varied continuously from left
hemisphere dominant to bilateral representation. In males, language primarily
lateralized to left, and in females, approximately half had left lateralization
and the other half had bilateral representation. Our data indicate that a
previous view of female bilateral hemispheric dominance for language (McGlone,
1980. Sex differences in human brain asymmetry: a critical survey. Behav Brain
Sci 3:215-263; Shaywitz et al., 1995. Sex differences in the functional
organization of the brain for language. Nature 373:607-609) simplifies the
complexity of cortical language distribution in this population. Analysis of the
distribution of the lateralization index in our study allowed us to make this
difference in females apparent.
PMID- 10785253
TI - Cores in hypothyroid myopathy: a clinical, histological and immunofluorescence
study.
AB - Fifteen patients with primary hypothyroidism were evaluated neurologically.
Needle biopsies of skeletal muscle were obtained using a Bergstrom needle. In 73%
of the patients, cores were identified histologically and by electron microscopy
in the skeletal muscle of these patients. The presence of cores correlated with
the severity of hypothyroidism, muscle hypertrophy, cramps and the duration of
the hypothyroid state. There was no significant correlation with muscle weakness.
Immunofluorescence studies with N-CAM antibodies demonstrated staining of the
sarcolemma, cytoplasm and central regions (cores) in the hypothyroid muscle.
These imply that the presence of cores in hypothyroid myopathy is due to
reactivation of embryonic proteins that disrupt skeletal muscle architecture.
PMID- 10785254
TI - Interobserver reproducibility among neuropathologists and surgical pathologists
in fibrillary astrocytoma grading.
AB - Many of the problems associated with the current grading approaches for
fibrillary astrocytomas center around the lack of consistency in grading. This
study compares the diagnoses of five neuropathologists with five experienced
surgical pathologists with regard to assigning astrocytoma grade. Thirty
neoplastic and non-neoplastic lesions were sent to each of five neuropathologists
and five surgical pathologists for placement into one of three grades as outlined
by modified Ringertz schema. Grading criteria (Burger et al., 1985. Cancer
56:1106-1111) were distributed to all participants, who have been practicing for
at least 5 years. An additional category for non-neoplastic or normal tissue was
also provided. The diagnoses, based on the majority opinion of the
neuropathologist group, included six low grade astrocytomas, 11 anaplastic
astrocytomas, seven glioblastoma multiforme, and six normal/reactive lesions.
Agreement by all neuropathologists was reached in 12 cases (40%). A discrepant
diagnosis was obtained in one of five neuropathologists in 14 additional cases
(46.7%). In the remaining four cases, two neuropathologists deviated from the
majority opinion; in each of these cases, the diagnostic problem involved
differentiating tumor from reactive gliosis. All five surgical pathologists
agreed in six cases (20%). One discrepant diagnosis among the surgical
pathologist group was seen in seven cases (23.3%). In the remaining 17 cases, two
or more discrepant diagnoses were obtained (56.7%); discrepancies in these cases
included differences in assignment of tumor grade and in distinguishing low grade
astrocytoma from gliosis. IN CONCLUSION: (1) it is likely that experience with
grading accounts for the better level of agreement among the neuropathologist
group (kappa statistic 0.63) versus the surgical pathologist group (kappa
statistic 0.36); (2) in most cases, the neuropathologists all agreed or had one
discrepant diagnosis (86.7%) versus the surgical pathologist group (43.3%); (3)
the discrepancies in diagnosis among both groups is likely related, in good part,
to the limitations of the grading schema in fully enumerating the spectrum of
such grading parameters as cytologic atypia and vascular proliferation.
PMID- 10785255
TI - Presynaptic impairment of cerebellar inhibitory synapses by an autoantibody to
glutamate decarboxylase.
AB - Glutamic acid decarboxylase (GAD), the enzyme responsible for converting
glutamate to gamma-aminobutyric acid (GABA), is a target of humoral autoimmunity
in stiff-man syndrome and subacute cerebellar ataxia. Recently, we found that an
anti-GAD autoantibody in the CSF of an ataxic patient selectively suppressed GABA
mediated transmission on cerebellar Purkinje cells without affecting glutamate
mediated transmission. Here, we examine the mechanism by which the autoantibody
impaired the inhibitory transmission, using immunohistochemistry and whole-cell
recording in rat cerebellar slices. The present results indicate that CSF
immunoglobulins prepared from an ataxic patient acted on the presynaptic
terminals of GABAergic interneurons and decreased GABA release onto Purkinje
cells.
PMID- 10785256
TI - Prevalence of triplet repeat expansion in ataxia patients from Hokkaido, the
northernmost island of Japan.
AB - Approximately 44% of cases of spinocerebellar ataxia (SCA) in Hokkaido, the
northernmost island of Japan, were estimated to be inherited. To determine the
prevalence of triplet repeat expansion in hereditary SCA patients, we genotyped
seven genetically defined dominant SCAs in 349 patients, including 266 patients
from 77 families, 78 probands from unrelated families with hereditary late-onset
SCA, and five patients in whom a family history of SCA was not demonstrated. The
frequency of each disorder in a total of 155 unrelated families was 23.9% for
Machado-Joseph disease (MJD), 29.0% for SCA6, 9.7% for SCA1, 7.7% for SCA2, and
2.6% for dentatorubral-pallidoluysian atrophy. Abnormal expansion of triplet
repeats for SCA7 and SCA8 was not detected. A total of 27.1% of the patients had
still unknown SCA mutations. In addition, the GAA repeat in the frataxin gene was
not abnormally expanded in 13 early-onset SCA patients with clinical features
similar to those of Friedreich ataxia. Comparison of our results with those from
other centers handling SCA showed that MJD is prevalent throughout Japan, but the
frequencies of other dominant SCAs differ considerably even within Japan.
PMID- 10785257
TI - Effect of propentofylline (HWA 285) on focal ischemia in rats: effect of
treatment and posttreatment duration on infarct size.
AB - BACKGROUND AND PUROSEe: in this study we tested the potentially neuroprotective
properties of propentofylline in a model of focal ischemia with long-term,
repeated treatment. METHODS: 37 male Wistar rats (280-300 g) underwent permanent
occlusion of the middle cerebral artery (MCA). Infusion was started 30 min after
occlusion of the MCA over a period of 2 h with a dosage of 0.01 mg/kg body
weight. Immediately after the termination of infusion repetitive intraperitoneal
injections were started. Animals were assigned to four groups: continuous
treatment for a period of 12 h with 24-h survival (group A, n=9) or 48-h survival
(group B, n=10), continuous treatment for a period of 48 h with 48-h survival
(group C, n=9) and placebo (group D, n=9). Infarct size was calculated from brain
slices stained with 2,3,5-triphenyltetrazolium chloride. RESULTS: the infarct
size was significantly reduced in group C (treatment for 48 h) (163.9+/-30.5
mm(3)) compared to the placebo group (297.4+/-17. 7 mm(3)). No effect on infarct
size was observed in group A (196. 8+/-37.3 mm(3)) and group B (239.6+/-42.9
mm(3)) compared to placebo. CONCLUSION: continuous i.p. injections of
propentofylline over a period of 48 h significantly reduces infarct size in an
animal model of focal cerebral ischemia. With shorter periods of continuous
administration of the drug and delayed postmortem analysis, reductions in the
infarct size did not reach a level of significance. These data show the
importance of continuous long-term administration after ischemic stroke in
clinical trials to achieve the beneficial effects of neuroprotection by
propentofylline.
PMID- 10785258
TI - Parkinson's disease impairs the ability to change set quickly.
AB - We tested the hypothesis that basal ganglia dysfunction in Parkinson's disease
impairs the ability to quickly change set. The ability to change set was inferred
by measuring the change in the amplitude of automatic gastrocnemius or tibialis
anterior muscle responses in standing subjects: (1) when the direction of a
surface perturbation changed from a backward translation to a toes up rotation;
and (2) when subjects were instructed to 'give' or 'resist' while responding to
the translations and rotations. In experiment 1, a change in sensorimotor set was
assessed by the suppression of gastrocnemius responses to toes up rotations
following a series of backward translations. Unlike healthy young and older
subjects, Parkinson subjects did not change sensorimotor set immediately to the
first rotation, but needed several rotations to change their responses. When
required to alternate their responses between backward translations and toes up
rotations, Parkinson subjects showed a smaller amplitude change in gastrocnemius
responses. In experiment 2, Parkinson subjects had more difficulty in using
cognitive set to modify their responses, especially when instructed to 'resist'
the perturbations. A small number of healthy older subjects also had difficulties
changing set quickly, but to a lesser extent than the Parkinson subjects.
Levodopa medication did not improve the Parkinson subjects' ability to change set
quickly. These results suggest that the basal ganglia, which are affected in
Parkinson's disease, are critical neural substrates in the ability to change set
quickly.
PMID- 10785259
TI - Membrane-bound macrophage colony-stimulating factor and its receptor play
adhesion molecule-like roles in leukemic cells.
AB - Membrane-bound macrophage colony-stimulating factor (m-M-CSF) is the membrane
form M-CSF by alternative splicing. J6-1 leukemic cell line spontaneously forms
cell clusters, whose growth depends on the auto-juxtacrine mediated by m-M-CSF
and its receptor (M-CSFR). In this study, M-CSFR isolated from J6-1 cells and
recombinant human M-CSF soluble receptor (rh-M-CSFsR) were used to study their
effects on J6-1 cells. Both receptors inhibited cell proliferation. Use of M-CSFR
monoclonal antibodies, M-CSFR or rh-M-CSFsR to block either M-CSFR or m-M-CSF on
cell surface inhibited the cluster forming process, while both receptors
stimulated cells adhering to culture plate. Furthermore, M-CSFR and/or rh-M-CSFsR
caused multiple cellular changes including cytoplasmic pH, multinuclear cell
ratio, antigen expression and cell diameter. A [Ca(2+)] rise was induced within
90 s by both receptors. Western blot experiments showed that rh-M-CSFsR caused
tyrosine phosphorylation on multiple cytoplasmic proteins of 45 kDa and 55-90
kDa, which could be blocked by H7. These observations suggested that m-M-CSF and
M-CSFR mediate J6-1 cell intercellular adhesion with bi-directional signal
transduction, and Ca(2+), protein tyrosine kinases, PKC and/or other H7 sensitive
kinase(s) involve in the counter-directional signal transduction.
PMID- 10785260
TI - Indomethacin induces apoptosis and inhibits proliferation in chronic myeloid
leukemia cells.
AB - A nonsteroidal anti-inflammatory drug (NSAID)--indomethacin (IN), was found to
induce apoptosis and inhibit proliferation of K562 cells and primary culture bone
marrow cells from six chronic myelogenous leukemia (CML) patients. IN induced
cells apoptosis and inhibited cells proliferation in a dose-and time-dependent
manner, the optimum IN concentration and incubation time for eliciting these
effects were 400 micromol/l and 72 h, respectively. A synergic effect on Vp-16
(2.5 microg/ml) induced apoptosis was observed when combined with 100 micromol/l
IN in K562 cells. RT-PCR results showed that IN down-regulated Bcl-2 mRNA
expression, and did not change Bax mRNA expression; Western blot results
confirmed that IN inhibited Bcl-2 protein expression, no influence was found on
the translative level of bax protein. Our study indicate that IN induce apoptosis
of CML cells by down-regulating Bcl-2 expression partially, and there is a
potential significance in the treatment of CML.
PMID- 10785261
TI - Thiazolidinedione suppresses the expression of erythroid phenotype in
erythroleukemia cell line K562.
AB - The activation of PPARgamma:RXR nuclear system induces monocytic differentiation
of some myelogeneous leukemia cell lines. The present study was undertaken to
examine the effect of PPARgamma ligand, TZD (troglitazone or pioglitazone) and/or
RXR selective ligand, LG100268 on the erythroleukaemia cell line K562 which has
both an erythroid character and a potential for differentiation into
megakaryocytes. TZD suppressed cell proliferation and the erythroid phenotype of
K562 cells. The suppression of erythroid phenotype of K562 cells by TZD was
synergistically enhanced by the combined treatment with LG100268. Moreover, the
marked suppression of erythroid phenotype in K562 cells was also accompanied by
the downregulation of the erythroid lineage-transcription factor, GATA-1. These
novel actions of troglitazone may provide a biochemical basis for anemia
occasionally which is observed after the in vivo administration of TZD.
PMID- 10785263
TI - Effects of cytokines on CD20 antigen expression on tumor cells from patients with
chronic lymphocytic leukemia.
AB - Anti-CD20 antibody is an established treatment for low-grade non-Hodgkin's
lymphoma (NHL). Augmenting the expression of CD20 antigen on the tumor cells may
increase the cell kill and therefore increase the effectiveness of the antibody.
To study this, we incubated peripheral blood lymphocytes from CLL patients with
the following cytokines: EPO, SCF, TNFalpha, TGFbeta, GMCSF, TPO, IL-1, IL-2, IL
3, IL-4, GCSF. CD20 expression was studied by flow cytometry at baseline, 24 and
72 h after exposure to these cytokines. Upregulation of CD20 antigen expression
was observed with IL-4, TNFalpha and GMCSF.
PMID- 10785262
TI - Analysis of thrombopoietin receptor (c-mpl) mRNA expression in de novo acute
myeloid leukemia.
AB - Expression of the thrombopoietin receptor, c-mpl, has been recently suggested to
represent an adverse prognostic factor in myelodysplasia and acute myeloid
leukemia (AML). To further evaluate this putative correlation, we assessed the c
mpl mRNA expression in blast samples of 53 AML patients. Overall, c-mpl mRNA
expression was observed in 27 (51%) patients. No significant difference between c
mpl(+) and c-mpl(-) patients was found with respect to established prognostic
factors such as age (50 vs. 53 years) or karyotype, whereas a significant
correlation was observed between c-mpl and CD34 expression (P = 0.026). Among 40
patients who completed standard-/high-dose cytarabine-containing
induction/consolidation treatment and were evaluable for treatment response, a
higher complete remission (CR) rate was achieved in c-mpl- than in c-mpl(+)
patients (95 vs. 68%; P = 0.026). Upon multivariate analysis, this relationship
was independent from CD34 expression. CR duration was not significantly longer in
c-mpl(-) than in c-mpl(+) patients (median: 14 vs. 10 months, P = 0.262). In
conclusion, our data strongly support the previously suggested notion that c-mpl
expression is of prognostic relevance for CR induction in de novo AML patients,
and suggest determination of c-mpl expression within larger prospective studies
in the attempt to develop risk-adapted AML treatment strategies.
PMID- 10785264
TI - Myelodysplastic syndrome at a large tertiary care community hospital: analysis
according to the international prognostic scoring system.
AB - The outcome of patients diagnosed myelodysplastic syndromes (MDS) between 1990
and 1997 from William Beaumont Hospital (WBH) was analyzed according to the
International Prognostic Scoring System (IPSS) risk categorization. A
retrospective study of 195 MDS patients wa s performed. Seventy-nine patients
with MDS, in whom a karyotype was obtained and with an adequate follow-up were
included in the final analysis. Cases of proliferative CMML (WBC > 12x10(9)/l)
were excluded from the study. The overall median survival was 3.1 years, and
median survival stratified by IPSS was 3.4, 4.1 and 0.5 years for the INT-1, INT
2 and high risk group and not yet reached for the low risk group. The overall
survival by IPSS subcategorization were 6.88, 5.29, 5.30 and 2.12 years for the
low, INT-1, INT-2, and high risk groups respectively. Cytogenetics were
significant in predicting the overall survival. The IPSS score stratified
patients into risk categories for development of AML. The risk of development
into AML was 8, 8, 33 and 54% for the low, INT-1, INT-2 and high risk groups,
respectively. We conclude that IPSS score can be useful in predicting survival
and AML evolution in some MDS patients.
PMID- 10785265
TI - Bone marrow purging by photodynamic treatment in children with acute leukemia:
cytoprotective action of amifostine.
AB - In order to evaluate the combined effect of Amifostine and Merocyanine 540 during
photoirradiation in neoplastic cells, bone marrow cells from children with acute
leukemia (AL), age-matched controls as well as HL-60 cell line were studied. Cell
suspensions were incubated with Amifostine, then with MC 540 and they were
subsequently exposed to different irradiation doses by Argon Laser 514 nm. Cell
survival was estimated by trypan blue supravital stain following a 24-h
incubation. The leukemic cell line was studied in continuous liquid cell cultures
for 4 weeks. The survival of normal bone marrow progenitors has been estimated by
colony formation assay in methylcellulose cultures. Our results showed that
Amifostine enhances the photokilling effect of MC 540 on leukemic cells and
significantly protects bone marrow nucleated and committed progenitors (BFU-E and
CFU-GM) from children with AL under chemotherapy. In conclusion, Amifostine seems
to be a promising cytoprotective agent in the clinical use of purging with MC 540
mediated phototherapy.
PMID- 10785266
TI - Qualitative and quantitative characterization of Fas (CD95) expression and its
role in primary human acute leukemia cells.
AB - Fas antigen, a cell surface molecule, directly mediates apoptosis, and is
expressed on a limited number of human tissues. Blood or bone marrow samples from
patients with acute myelogenous leukemia (AML), acute lymphoblastic leukemia
(ALL) and mixed leukemia were examined qualitatively and quantitatively for the
expression of Fas as well as its function using flow cytometry and the annexin V
staining method. Fas expression was flow cytometrically unimodal with
heterogeneous density, and showed quantitatively characteristic features in
different diseases: undetectable in mixed leukemia, faint to weak in ALL, low in
M0 and M1, and variable (low to strong) in M2, M3, M4, and M5. Both the full
length and the alternatively spliced truncated mRNAs were detected constitutively
even in acute leukemia cells with qualitatively negative and quantitatively faint
Fas, and the band density of the former transcripts detected by RT-PCR was
correlated with the level of expression of the Fas protein. Short-term culturing
of freshly isolated leukemia cells gave rise to an increase of Fas density. In
acute leukemia cells, the apoptosis induced by anti-Fas MoAb was compared with
that induced by etoposide (a topoisomerase II inhibitor). We found that fresh ALL
and AML cells were resistant to the anti-Fas IgM antibody, while etoposide could
trigger apoptosis in all types of leukemia tested. The combined effects of the
anti-Fas MoAb and etoposide were not always synergistic. These results suggest
that Fas is a biological marker for characterizing ALL and AML cells, and provide
insight into creating a new therapeutic modality using cytotoxic drugs and
cytokines together with modulation of Fas.
PMID- 10785267
TI - In vitro chemosensitivity testing in acute non lymphocytic leukemia using the
bioluminescence ATP assay.
AB - The ATP assay is a short term in vitro chemosensitivity assay where the amount of
viable cells are determined by their content of ATP. The aim of the study was to
compare the in vitro results of six cytostatic drugs to the clinical outcome in
83 acute non-lymphocytic leukemia (ANLL) patients. The secondary ANLL at
diagnosis showed an in vitro resistance to daunorubicin that was significantly
higher compared to de novo ANLL at diagnosis (P<0.003). De novo ANLL at diagnosis
that achieved complete remission (CR) were significantly more sensitive to
daunorubicin compared to those who didn't achieve CR (P<0.05). There was an vitro
correlation between topoisomerase II active drugs but not between these drugs and
ara-C. In vitro ara-C sensitivity (< or = the median of the de novo ANLL at
diagnosis) was correlated to poor overall survival (P = 0.02). In vitro
sensitivity to daunorubicin and mitoxantrone was associated with prolonged
disease free survival (P = 0.03 and P = 0.04). We conclude that despite
significant correlation to clinical parameters for daunorubicin and mitoxantrone
the predictive value of the ATP assay in this material was insufficient for
directing therapy.
PMID- 10785268
TI - A novel translocation t(3;22)(q21;q11) involving 3q21 in myelodysplastic syndrome
derived overt leukemia with thrombocytosis.
AB - We report here a novel translocation t(3;22)(q21;q11) in myelodysplastic syndrome
(MDS)-derived overt leukemia with thrombocytosis. A 44-year-old female was
initially diagnosed as MDS with a low platelet count and normal karyotype. After
4 months, blood leukemic cells and platelets rapidly increased concomitantly and
a diagnosis of acute myeloblastic leukemia (AML M1) was made. Chromosome analysis
showed 46, XX, t(3;22)(q21;q11) in 14 of 20 metaphases. Fluorescence in situ
hybridization analysis confirmed both the der(3)t(3;22) and the der(22)t(3;22).
Our results suggest that unidentified gene(s) at 3q21 breakpoint may be
implicated in the pathogenesis of abnormal thrombopoiesis as observed in the
3q21q26 syndrome.
PMID- 10785269
TI - Marsupial immunology: out of the pouch.
PMID- 10785270
TI - Development of the immune system and immunological protection in marsupial pouch
young.
AB - At birth the tissues of marsupial immune system are underdeveloped. The young
animal is not immunocompetent. Histological and immunohistochemical studies of
pouch young epithelial tissues provide a clear picture of tissue development but
the timing of onset of immunocompetence awaits definition. The survival of the
neonatal marsupial in a microbially rich environment is dependent on maternal
strategies, including immunoglobulin transfer via milk and, in some species,
prenatally via the yolk sac placenta. It is also likely that pouch secretions
play a role. This review summarizes our current knowledge of the pathway of
immunological development in marsupials and the protection and threats afforded
by the pouch environment.
PMID- 10785271
TI - The roles of histology and immunohistology in the investigation of marsupial
disease and normal lymphoid tissue.
AB - This review acquaints scientists with current information related to the
application of histology and immunohistology to the studies of normal lymphoid
tissues and specific diseases in marsupials. Histological examination of tissue
is a necessary prerequisite for immunohistological examination because it
establishes tissue structure and detects specific areas of disease which allow
the selection of smaller areas for immunohistological examination. Information is
provided on the basic techniques of histology. Immunohistology
(immunohistochemistry) refers to the identification of antigenic determinants of
specific substances (proteins) by the application of antibodies to histological
sections. Information is provided on a technique for enzyme based, avidin-biotin
enhanced immunohistology, and on antibodies that can be used to mark disease
agents or marsupial tissues and cells. A summary is provided of the available
information on studies of the histology and immunohistology of normal marsupial
lymphoid tissue (thymus, spleen, lymph nodes and mucosa associated lymphoid
tissue), and of selected marsupial diseases such as chlamydiosis and
lymphosarcoma in koalas.
PMID- 10785272
TI - Marsupial cytokines. Structure, function and evolution.
AB - The cytokines are an important group of molecules involved in coordinating the
many and varied components of the immune system. These molecules have been
extensively studied in model eutherian mammals such as mice but comparatively
little is known about the cytokine network of marsupials. Such information will
be invaluable in elucidating fundamental aspects of the marsupial immune system
and will also highlight parallels and differences between the immune systems of
marsupials and eutherians. Given the importance of these goals, our groups have
recently begun to tackle this lack of knowledge of the marsupial cytokine system
and have met with considerable success in the face of the rapid rate of change of
these proteins. This has led to the isolation of the full-length sequences
encoding marsupial orthologues of tumour necrosis factor (TNF), lymphotoxins
alpha and beta (LT-alpha and beta), interleukin-1 beta (IL-1beta), and
interleukin-10 (IL-10). Here we review what has been learnt about structural,
functional and evolutionary aspects of these marsupial cytokines as well as
briefly describing more recent work in progress and future directions in this
field.
PMID- 10785273
TI - Immunoglobulin genetics of marsupials.
AB - Until recently, studies of marsupial immunoglobulins were limited to primarily
protein analyses, such as Protein A binding and immunological cross-reactivity to
eutherian immunoglobulins to draw conclusions about the isotypes present in
metatherians. This left an interesting gap in our knowledge of the evolution of
vertebrate, more specifically mammalian, antibodies and provided little insight
into the diversity of marsupial antibodies. Recently, however, there has been a
flurry of papers from multiple laboratories describing, at the molecular level,
the heavy and light chain classes present in marsupials with some analysis of the
expressed repertoires. These studies have provided the evidence to determine when
some of the uniquely mammalian isotypes, e.g. IgG and IgE, appeared in evolution,
and are a first look at the complexity of heavy and light chain variable regions
in a metatherian. Here we review what was known prior to the cloning of marsupial
Ig genes and what we have learned recently.
PMID- 10785274
TI - Immunological protection of the vulnerable marsupial pouch young: two periods of
immune transfer during lactation in Trichosurus vulpecula (brushtail possum).
AB - Marsupial young are born with an underdeveloped immune system and are dependent
upon passively acquired immune protection provided by the mother's milk.
Colostrum and milk samples were collected from the brushtail possum throughout
lactation and the concentration of secretory IgA (sIgA), IgG and transferrin was
determined by Western blotting. Two periods of immune transfer were identified.
The first, a colostral phase, occurs immediately after birth and involves sIgA,
IgG and transferrin. During the early lactation stage, pouch young receive milk
of a unique composition as they undergo developmental changes in the pouch that
occur in utero for eutherian mammals. At the end of this external gestation, the
composition of the milk changes (switch phase) to resemble that of eutherian
mammals in the late lactation phase. The second transfer of immunity consists of
IgG and transferrin, and occurs during the switch phase prior to maturation of
the immune response.
PMID- 10785275
TI - Photobiology of Monodelphis domestica.
AB - The gray, short-tailed opossum, Monodelphis domestica, has been used for
photobiologic studies since 1984. The presence of a light-activated DNA repair
pathway in the tissues of Monodelphis has been used to identify pyrimidine dimers
in DNA as initiating events for a number of ultraviolet radiation (UVR)-induced
pathologies of the skin and cornea. Furthermore, Monodelphis, unlike common
laboratory rodents, is susceptible to the induction of melanoma by UVR alone.
PMID- 10785276
TI - Immunobiology of mycobacterial infections in marsupials.
AB - Mycobacterial infections of marsupials are important for two reasons. Firstly,
the Australian brushtail possum (Trichosurus vulpecula) serves as the major
wildlife reservoir for Mycobacterium bovis in New Zealand and secondly, M. avium
is a significant cause of disease in endangered marsupial species held in
captivity. Marsupials are highly susceptible to specific mycobacterial infections
which may be linked to deficiencies in their cellular immunity. Histopathological
inspection of affected tissues indicates that, unlike most eutherians, marsupials
are unable to wall off infection sites, resulting in formation of satellite
lesions and generalised disease. This review examines possible reasons for the
high susceptibility of marsupials to mycobacterial infections and investigates
the prospects for developing vaccines to control these diseases.
PMID- 10785277
TI - Sensory channel specific modulation in the nucleus of the solitary tract.
PMID- 10785278
TI - The effects of cyclophosphamide on neurotransmission in the urinary bladder of
Suncus murinus, the house musk shrew.
AB - This study has shown that cyclophosphamide treatment of the insectivore Suncus
murinus, causes a down regulation in both muscarinic and P2X receptors, together
with a reduced responsiveness to exogenous histamine (0.3 mM) in the urinary
bladder. Electrical field stimulation (70 V, 0.3 ms, 0.5-16 Hz, 10 s every 5 min)
of bladders from both control and cyclophosphamide-treated animals showed
identical responses. Since post-junctional alterations have been revealed by the
reduced responsiveness to exogenous carbachol (0.1 microM-3 mM) and beta,gamma
methylene ATP (0.3-300 microM), it would appear that in the bladders of
cyclophosphamide-treated animals there is also a pre-junctional effect, increased
transmitter release compensating for the down regulation of the receptors. As the
pattern of neurotransmission of the bladder of suncus more closely resembles that
of human detrusor than other commonly studied laboratory animals, this
insectivore appears to be a useful animal model for the study of bladder
neurotransmission in pathophysiological conditions.
PMID- 10785279
TI - Cyanide intoxication induced exocytotic epinephrine release in rabbit myocardium.
AB - Cyanide intoxication, which has been used as a model of energy depletion at
cardiac sympathetic nerve terminals, causes non-exocytotic release of
norepinephrine (NE). However, the effect of cyanide intoxication on cardiac
epinephrine (Epi) release remains unknown. Using cardiac microdialysis in the
rabbit, we measured dialysate Epi and NE concentrations as indices of myocardial
interstitial Epi and NE levels, respectively. Local administration of sodium
cyanide (30 mM) through the dialysis probe increased both Epi and NE levels (from
11.3+/-2.3 to 32.3+/-4.4 pg/ml and from 33.6+/-6.1 to 389.0+/-71.8 pg/ml,
respectively, mean+/-S.E., P<0.01). Local desipramine (100 microM) administration
suppressed the cyanide induced NE response without affecting the Epi response. In
contrast, local omega-conotoxin GVIA (10 microM) administration partially
suppressed the cyanide induced NE response and totally abolished the Epi
response. In conclusion, cyanide intoxication causes N-type Ca(2+) channel
dependent exocytotic Epi release as well as inducing N-type Ca(2+) channel
independent non-exocytotic NE release.
PMID- 10785280
TI - Ultrastructural observations of fibroblast-like cells forming gap junctions in
the W/W(nu) mouse small intestine.
AB - The ultrastructure of the wild-type (+/+) mice small intestine was compared with
c-kit mutant (W/W(nu)) mice which only have few interstitial cells of Cajal (ICC)
associated with Auerbach's plexus, in order to elucidate whether the specialized
membrane contacts are general features of so-called fibroblast-like cells that
are widely distributed in the tunica muscularis of the alimentary tract.
Fibroblast-like cells in the Auerbach region were found in approximately equal
number in W/W(nu) mice as in +/+ mice, while ICC associated with Auerbach's
plexus (ICC-AP) could not be demonstrated in W/W(nu) mice in the present
investigation. Fibroblast-like cells were characterized by cytoplasm of moderate
to high electron density, well developed rough endoplasmic reticulum and nuclei
with thick peripheral accumulations of heterochromatin. There were no basal
lamina and caveolae along the cell membrane. It was observed that single
fibroblast-like cells formed probable small gap junctions with muscle cells of
both circular and longitudinal layers. Fibroblast-like cells with the same
features were also observed in the region of the deep muscular plexus in both +/+
and W/W(nu) mice. The present observation, together with our previous studies on
rats and guinea-pigs, suggest the common presence of gap junctions or gap
junction-like structures on fibroblast-like cells in the gastrointestinal
musculature and their involvement in the regulatory system of gastrointestinal
motility by passing electrical or molecular signals to influence the state of
muscle tonus.
PMID- 10785282
TI - Inhibition of gastric motility by noxious chemical stimulation of interspinous
tissues in the rat.
AB - In urethane anesthetized, adult male Wistar rats, noxious chemical stimulation of
the mid to lower thoracic interspinous tissues, in the form of capsaicin
injection, was accompanied by a pronounced increase in gastric sympathetic nerve
activity and inhibition of gastric motility. Much weaker effects on gastric
sympathetic nerve activity and gastric motility were observed with similar
stimulation of the lower lumbar interspinous tissues. The inhibitory response of
gastric motility to thoracic stimulation was preserved in spinalized animals,
somewhat diminished in vagotomized animals and was abolished in most animals from
which the coeliac ganglion had been extirpated. In vagotomized animals, treatment
with 1 mg/kg propranolol i.v. did not cause any further attenuation of the
inhibitory reflex. However, the inhibitory reflex was extinguished in vagotomized
animals which received 1 mg/kg propranolol plus 10 mg/kg phentolamine i.v. These
results suggest that noxious chemical stimulation of the interspinous tissues
elicits a segmentally organized reflex which is mediated principally at the
spinal level and which expresses itself principally, but not exclusively via
sympathetic efferents traversing the coeliac ganglion. The expression of the
reflex response appears to be largely dependent upon the integrity of alpha
adrenergic receptors.
PMID- 10785281
TI - 17beta-estradiol modulates baroreflex sensitivity and autonomic tone of female
rats.
AB - The following experiments examine the role of estrogen as a central modulator of
autonomic tone and baroreflex sensitivity in the female rat. Female Sprague
Dawley rats were ovariectomized and then supplemented daily for 7 days with a
fixed dose of estrogen (5 microg/kg; sc) to produce a stable level of estrogen
similar to that present at proestrous (17 pg/ml). The rats were then
anaesthetized with sodium thiobutabarbital (100 mg/kg) and instrumented to record
blood pressure, heart rate and both vagal and renal efferent nerve activities.
The sensitivity of the cardiac baroreflex was tested using intravenous injection
of multiple doses of either phenylephrine hydrochloride or sodium nitroprusside.
Estrogen-supplemented female rats exhibited a significantly enhanced BRS as
compared to male rats from a previous study (0.78 vs. 0.5). Furthermore, bolus
injection of estrogen (1x10(-2) mg/kg; iv) in estrogen-supplemented female rats
produced a significant increase in vagal nerve activity and a significant
decrease in renal nerve activity which together resulted in a further enhancement
of the BRS (0.78 vs. 2.4). Injection of the selective estrogen receptor
antagonist, ICI 182,780, into nucleus ambiguus and the intrathecal space of the
spinal cord blocked the respective changes in parasympathetic and sympathetic
nerve activities indicating that intravenously administered estrogen modulates
baseline autonomic tone via the activation of central estrogen receptors.
PMID- 10785283
TI - Heart rate recovery post-exercise as an index of parasympathetic activity.
AB - The time constant (T) obtained by fitting post-exercise heart rate (HR) recovery
to a first order exponential decay curve has been promoted as an index of
parasympathetic activity. However, acceptance has been limited because reported
data are inadequate to assess goodness of fit for the model, determine the best
exercise protocol, or optimize the duration of post exercise monitoring.
Consequently, we evaluated T for nine healthy volunteers (age 24-46) following
treadmill exercise at maximal (max) and two stages sub-max exercise (Bruce
protocol). T stabilized only after 3 min of post-exercise monitoring. With max
exercise, T varied unacceptably with small changes in onset of monitoring, e.g.
16.7+/-16.6 (-13.2%) in the first 5 s, and residuals of the fitted curve were non
random. In contrast, sub-max exercise produced consistent T values, e.g. -1.9+/
3.2 (-4.2%) in the first 5 s, and residuals were more nearly random. In
conclusion, first order decay is an inadequate model for HR recovery following
max exercise, but may be reasonable for sub-max levels.
PMID- 10785284
TI - Attenuated cardiovascular adjustment to sustained static exercise after
carbohydrate loading.
AB - We examined whether a higher plasma lactic acid (LA) concentration resulting from
carbohydrate (CHO)-loading affects the cardiovascular responses to exercise
through a greater activation of LA-induced metaboreflex. Before and after CHO
loading, LA concentration, mean arterial blood pressure (MAP), heart rate (HR),
cardiac output (CO), rating perceived exertion (RPE), and integrated
electromyogram (iEMG) of the vastus lateralis were studied during a sustained
static knee extension of single legs in 16 volunteers. The CHO-loading comprised
an exhaustive bout of one-legged cycling (73+/-3% of maximal oxygen uptake for
130-160 min) and consuming a low-CHO diet for 2-3 days and a high-CHO diet for
the next 3 days. In the leg that performed the exercise (the experimental leg),
the LA concentration after CHO-loading was significantly increased, but the
magnitude of MAP, HR, and CO responses during static exercise was significantly
decreased in parallel with a significant reduction of RPE and iEMG. In the
control leg, there were no changes in the variables before and after CHO-loading.
These results suggest that the increased LA concentration resulting from CHO
loading did not affect the cardiovascular adjustment to the sustained exercise.
Other mechanisms related to the reduction of RPE and iEMG seem to be responsible
for the attenuated cardiovascular responses observed in the experimental leg
after CHO-loading.
PMID- 10785285
TI - Development of a highly sensitive quantitative competitive PCR assay for the
detection of murine cytomegalovirus DNA.
AB - Viral persistence and molecular latency are characteristic of infection by the
human cytomegalovirus (HCMV). Using the murine cytomegalovirus (MCMV) as a model
for human infection, a quantitative-competitive polymerase chain reaction (QC
PCR) assay was developed to detect and quantify MCMV-DNA in the salivary glands
of infected mice. The QC-PCR detected high numbers of MCMV DNA copies in the
absence of infectious virus. By comparing the DNA content and the results
obtained from a standard semiquantitative plaque assay, it is concluded that 1
plaque-forming unit (pfu) is the equivalent of approximately 1500 viral genomes.
By day 42-post infection (pi) 4x10(3) copies of DNA/1 mg tissue were sufficient
to reactivate infectious virions after cyclophosphamide immunosupression. By day
90 pi, however, when the DNA load was decreased to <1.2x10(2), reactivation was
not observed. These results indicate that viral reactivation will occur when the
number of infectious DNA copies is equivalent about 2-3 pfu. This quantitative
test may therefore help to detect CMV and the risk of reactivation in
immunosupressed patients.
PMID- 10785286
TI - The use of monoclonal antibody probes for the detection of avian reovirus
antigens.
AB - Two monoclonal antibodies (MAb), E9 and H3, prepared against avian reovirus (ARV)
S1133, were used in an immuno-dot assay to detect ARV antigens from cell culture
and from tendon tissue samples of chickens. The limit of viral antigens detected
was 8 ng using both MAb probes. The probes detected 10 ARV isolates representing
at least two serotypes or pathotypes. The results indicated that these probes had
broad specificity. The probes, however, did not cross-react with viral antigens
prepared from six unrelated avian viruses. The ARV antigens in tendon tissue
samples were detected by both probes, and it is possible, therefore, to use
either of the two MAb probes for detection of ARV infections.
PMID- 10785287
TI - Duplex RT-PCR: reagent concentrations at reverse transcription stage affect the
PCR performance.
AB - Test conditions for the simultaneous detection of potato leafroll virus (PLRV)
and potato virus Y (PVY) in dormant tubers and leaves by reverse transcription
polymerase chain reaction (RT-PCR) were optimized. Various factors optimized at
the reverse transcription (RT) stage rather than at the amplification (PCR) stage
affected the outcome. In the simplex RT-PCR a onefold dNTPs concentration (0.5
mM) was sufficient in yielding a PLRV or PVY band. In contrast, the duplex RT-PCR
required a minimum twofold dNTPs concentration (1.0 mM) during RT to produce
distinct bands in PCR. Similarly, various proportions of antisense primers of
PLRV and PVY used during RT affected subsequent duplex RT-PCR. Optimal
amplification of both viruses were obtained at a ratio of 0.90:0.49 microM of
PLRV:PVY antisense primers. An interaction of dNTPs and RNA template
concentration was observed. A higher concentration of RNA was required at onefold
dNTPs concentration than at twofold dNTPs. Dilutions down to 1:300 of RNA
template yielded distinct bands of both viruses at twofold dNTPs concentration.
At optimized conditions of the duplex RT-PCR both viruses were reliably detected
in composite samples at a ratio of one part infected sap mixed with 399 parts of
sap from healthy tubers. Application of optimized conditions to singly- and
doubly-infected tubers detected both viruses from naturally infected field-grown
tubers. A nearly perfect correlation (r(2)=0.99) was observed between visible
plant symptoms and the virus detection from leaves and tubers by the duplex RT
PCR.
PMID- 10785288
TI - Chimeric swine vesicular disease viruses produced by fusion PCR: a new method for
epitope mapping.
AB - A new method of epitope mapping based on chimeric swine vesicular disease (SVD)
viruses produced by fusion PCR (polymerase chain reaction). Seven out of 16
neutralising and non-neutralising newly produced monoclonal antibodies (MAbs)
discriminated between SVD isolate ITL/1/66 and NET/1/92. Using fusion PCR eight
chimeric viruses were produced containing different supplementary pieces of the
P1 region of both parent strains. Using these chimeric viruses we were able to
map the epitope regions recognised by these seven neutralising and non
neutralising Mabs. This new method, using chimeric viruses produced by fusion
PCR, is particularly valuable for the epitope mapping of non-neutralising MAbs.
PMID- 10785289
TI - Reproducibility of human immunodeficiency virus type 1 (HIV-1) protease and
reverse transcriptase sequencing of plasma samples from heavily treated HIV-1
infected individuals.
AB - The reproducibility of population-based human immunodeficiency virus type 1 (HIV
1) protease and reverse transcriptase (RT) sequencing was assessed using
replicate aliquots of cryopreserved plasma samples obtained from seven heavily
treated HIV-1-infected individuals. The sequence of each sample replicate was
compared with the consensus sequence for that sample and 99.4% of 35128 amino
acids were found to be concordant with the sample consensus. Partial discordances
were present at 0.5% of positions and complete discordances were present at <0.1%
of positions. To assess the reproducibility at detecting mutations (defined here
as differences from the subtype B consensus sequence), the proportion of
sequences having a mutation when at least two sequences from that sample had the
same mutation were examined. There was a median of 13 protease and 18 RT
mutations per sample for a total of 3126 mutations; 95% of these mutations were
detected. However, sequencing of multiple clones from two samples demonstrated
that those mutations present in a minority of clones were often not detected by
population-based sequencing. These results suggest that HIV-1 protease and RT
sequencing of circulating plasma virus is highly reproducible but that the
sensitivity at detecting mutations may be low if those mutations are present as
minor variants.
PMID- 10785290
TI - Simplified, rapid method for cloning of virus-binding polypeptides (putative
receptors) via the far-western screening of a cDNA expression library using
purified virus particles.
AB - A simplified, alternative method for cloning virus-binding polypeptides (receptor
candidates) is described. The method is based on a far-Western assay using
purified tomato spotted wilt tospovirus (TSWV, Bunyaviridae) for screening a
lambda-phage cDNA expression library. The western flower thrips, Frankliniella
occidentalis Pergande, the principal vector of TSWV, in which the virus
replicates, was used for library construction. Using this method several virus
binding polypeptides were identified, it eliminated the need for (a) a cellular
infection or binding system, (b) the identification, cloning and expression of a
functional viral attachment protein, or (c) the purification of the virus
receptor. Using this method, virus-binding polypeptides can be selected and
cloned in a very short period of time and used in subsequent experiments for
determination of their biological relevance as virus receptors and/or tested for
potential usefulness as inhibitors of virus transmission and/or infection.
PMID- 10785291
TI - Anchored oligo(dT) primed RT/PCR: identification and quantification of related
transcripts with distinct 3'-ends.
PMID- 10785292
TI - Production of high-titer stocks of the English strain of rat cytomegalovirus.
AB - A simple technique to increase dramatically the yield of rat cytomegalovirus
(RCMV) from infected monolayers of a rat embryo fibroblast-derived cell line is
described. The method, which involves daily changes of the cell culture medium,
can result in a 50000-fold amplification of virus from cell monolayers inoculated
with only a few RCMV particles. This modification of the standard in vitro
culture technique to amplify viral yield can be used to increase the sensitivity
of the plaque assay for detecting very small amounts of infectious virus in organ
homogenates of RCMV infected animals.
PMID- 10785293
TI - Detection of multiple potato viruses using an oligo(dT) as a common cDNA primer
in multiplex RT-PCR.
AB - A novel usage of multiplex reverse transcription polymerase chain reaction (m-RT
PCR) for simultaneous detection of multiple viruses is reported. By use of an
oligo(dT), as a common primer, nearly full-length cDNAs can be synthesized.
Furthermore, combining an oligo(dT) primer with a specific antisense primer can
be used to simultaneously prime reverse transcription of both polyadenylated and
non-polyadenylated RNAs. Four viral genera including five potato viruses
[(carlavirus (PVS), polerovirus (PLRV), potexvirus (PVX), potyvirus (PVA and
PVY))] and a viroid genus including a viroid genome (pospiviroid (PSTVd)) were
used to develop various formats of m-RT-PCR. In artificially created viral RNA
mixtures, all six RNA pathogens were detected successfully by uniplex- and m-RT
PCR. In naturally infected field grown tubers, m-RT-PCR detected infection of two
to three viruses, which were present in the tubers.
PMID- 10785294
TI - Direct resin composite inlays/onlays: an 11 year follow-up.
AB - OBJECTIVES: The aim of this study was to present an 11-year assessment of direct
resin composite inlays/onlays. METHODS: One-hundred Class II direct resin
composite inlays and 34 direct resin composite restorations were placed in 40
patients. The restorations were evaluated clinically, according to modified USPHS
criteria, annually over a 11-year period. RESULTS: Of the 96 inlays/onlays and 33
direct restorations evaluated at 11 years, 17. 7% in the inlay/onlay group and
27.3% in the direct restorations group were assessed as unacceptable. The
differences in longevity were not statistically significant. The main reasons for
failure for the inlays/onlays and direct restorations were fracture (8.3 and 12.
1%, respectively), occlusal wear in contact areas (4.2 and 6.1%, respectively)
and secondary caries (4.2 and 9.1%, respectively). Eight of the non-acceptable
inlays/onlays and five of the direct restorations were replaced, while the other
ones were repaired with resin composite. Unacceptable wear was observed in
occlusal contact areas of six restorations, in patients who were severe bruxers.
For the other restorations occlusal wear was not found to be a clinical problem
and no difference was observed between the inlays/onlays and direct composite
restorations. The marginal adaptation of the inlays/onlays was still good at the
end of the study. Ditching was only observed in a few inlays. A higher failure
rate was observed in molar teeth than in premolar teeth. CONCLUSIONS: Good
durability was observed for the direct resin composite inlay/onlay technique.
Excellent marginal adaptation and low frequency of secondary caries in patients
with high caries risk were shown. No apparent improvement of mechanical
properties was obtained by the secondary heat treatment of the inlays. Also, the
difference in failure rate between the resin composite direct technique and the
inlay technique was not large, indicating that the more time-consuming and
expensive inlay technique may not be justified. The direct inlay/onlay technique
is recommended to be used in Class II cavities of high caries risk patients with
cervical marginal placed in dentin.
PMID- 10785295
TI - Caries-associated micro-organisms in infants from different socio-economic
backgrounds in Scotland.
AB - OBJECTIVES: The aims of this study were: (1) to compare the frequency of
isolation of mutans streptococci, (Streptococcus mutans, Steptococcus sobrinus),
lactobacilli and yeasts (caries-associated micro-organisms) in the saliva of 1
year-old infants with and without dental caries; and (2) to determine if socio
economic background influenced the frequency isolation of bacteria and caries
status. METHODS: 1393 1-year-old consented infants, who comprised 70. 3% of
children born in Dundee during a 1year period, had saliva samples taken (tongue
loop method) for microbiological culture and were examined for dental caries
(d(1)-threshold: enamel and dentine diagnostic threshold). Thirty-nine infants
were diagnosed with caries and the frequencies of isolation of caries-associated
micro-organisms (and absolute microbial counts) were compared with infants who
were caries-free. In addition, associations were sought between the infants'
socio-economic background, the frequency of isolation of caries-associated micro
organisms and caries status. RESULTS: Streptococcus mutans, lactobacilli and
yeasts were isolated more frequently from those infants with caries compared to
those who were caries-free (S. mutans: 29.7 vs 9.8%, P=0.0008; lactobacilli: 15.4
vs 4.3%, P=0.0073; yeasts: 23.7 vs 10.4%, P=0.0016-Fisher's exact test). There
were no significant differences between the isolation frequencies of S. sobrinus
(2.7 vs 1.3%, P=0.39) from those with and without caries. Significantly, more
infants living in areas of high deprivation had caries compared to those from
more affluent areas (DEPCAT 6 and 7 vs 1-5: 3.6 vs 1.9%, P=0.049), but, apart
from yeasts, socio-economic background was not significantly associated with the
isolation frequencies of any of the caries-associated micro-organisms.
CONCLUSIONS: In infants as young as 1year of age, salivary S. mutans,
lactobacilli and yeasts but not S. sobrinus were isolated significantly more
frequently from those with caries compared to those who were caries-free. Apart
from yeasts, socio-economic background did not influence the frequency of
isolation of caries-associated micro-organisms. However, infants living in areas
of highest deprivation had significantly higher frequencies of caries compared to
those from more affluent areas.
PMID- 10785296
TI - General dental practitioners diagnostic and treatment decisions related to
fissure sealed surfaces.
AB - OBJECTIVES: The purpose of this in-vitro study was to assess the validity and
reproducibility of the diagnosis and treatment planned for occlusal surfaces
prior to and following the placement of a clear sealant by a sample of general
dental practitioners (GDPs). METHODS: 160 permanent posterior teeth were examined
by 25 GDPs. The GDPs were not given any criteria and were therefore free to
diagnose and plan care, as they felt appropriate. Each GDP conducted four
examinations, two prior to and two after sealing. The teeth were serially
sectioned to provide the validating criterion. RESULTS: After sealant placement,
there was a statistically significant increase in specificity and decrease in
sensitivity of both diagnostic and treatment decisions. The reproducibility
expressed by the kappa-statistic was of the order of 0.5 prior to and after
sealing with regard to diagnostic decisions. There was a general tendency to
diagnose less disease after placement of a sealant (P<0. 001). There was also
significantly less care (preventive or restorative) planned after sealant
placement (P<0.001). CONCLUSIONS: The placement of a sealant resulted in the
diagnosis of less disease and less restorative treatment. This may be appropriate
as evidence exists to support the use of sealants as caries therapeutic agents.
PMID- 10785297
TI - Enamel demineralisation assessed by computerised image analysis of clinical
photographs.
AB - OBJECTIVES: To investigate the use of computerised image analysis to measure the
area of demineralisation on the buccal surface of a tooth and to analyse the
effect on that measurement of varying the angle at which a photographic image of
the buccal surface of a tooth is taken. METHODS: Twenty-two teeth with areas of
incremental demineralisation on the buccal surface were photographed
perpendicular to the buccal surface and at angles of 20 and 40 degrees, above
(Cuspal) and below (Gingival) the perpendicular. The images were captured and
analysed using computerised image analysis. RESULTS: The Gingival views showed
lower limits of agreement than the Cuspal views, probably due to the positioning
of the masking on the lower part of the flash, to reduce reflection. There was a
significant difference between the areas of demineralisation measured for the
three angles from the Gingival views (p<0.001). The mean differences in areas
measured were not linear, but there was a significantly greater reduction in area
measured for the 40 degrees views. CONCLUSIONS: Computerised image analysis to
measure areas of demineralisation from a captured 35mm slide is reproducible. The
position of the masking on the camera flash and the angle of the camera makes a
difference to the area measured and the grey scales recorded. Images taken at a
larger angle than 20 degrees to the perpendicular will record a significantly
reduced area of demineralisation. Standardisation of photographs with the use of
calibration markers and manipulation of images is discussed.
PMID- 10785298
TI - Human pulp reaction to dentine bonded amalgam restorations: a histologic study.
AB - OBJECTIVE: The aim of this study was to investigate the human pulp response to
Scotchbond Multi Purpose Plus (SMPP) bonding agent in non-exposed Class V
cavities. METHODS: SMPP was placed in 24 of 40 cavites according to
manufacturer's instructions and the cavities were restored with amalgam. The
remaining 16 cavities were capped with a calcium hydroxide formulation (Dycal)
sealed with zinc-oxide eugenol, and restored with the amalgam. After extraction
at 10 and 35 days, the teeth were fixed, sectioned and stained for light
microscopy. RESULTS: All Dycal-capped teeth, at both 10 and 35 days, exhibited no
pulp inflammation and no demonstrable bacteria. Six cases sealed with SMPP at 10
days showed no pulp inflammation or stained bacterial profiles. The remaining six
teeth demonstrated mild to moderate inflammatory pulpal responses and five out of
these six cases exhibited stained bacterial profiles. Nine out of 12 teeth showed
no inflammatory pulp responses at 35 days, the remaining three cases exhibited
mild to moderate pulp inflammation without stained bacteria. CONCLUSIONS: None of
the teeth sealed with SMPP presented severe inflammatory pulpal reactions
histologically. SMPP did not exhibit significant deleterious effects on the human
pulp tissue during the test periods.
PMID- 10785299
TI - Effects of topical Catalase application on dental pulp tissue: a
histopathological evaluation.
AB - OBJECTIVES: recently, the role of antioxidant enzymes in wound healing and their
therapeutic potential has been a subject of interest in medical sciences. However
there is restricted knowledge on the results of topical application, optimal
therapeutic dosage and carrier types. The purpose of this study was to
investigate the wound healing response of dental pulp after direct pulp capping
with an antioxidant enzyme; Catalase (C-40). METHODS: three mongrel dogs were
used in this study. A total of 32 perforated Cl V preparations were treated with
either 0.8mg (n=16) or 1.6mg (n=16) Catalase (C-40) which was incorporated in
gelatin carriers whereas 16 control teeth had carriers without Catalase. One
millimeter thick Teflon disks were placed over the gelatin pellets and the
cavities restored with silver amalgam. Short term and long term histopathologic
reactions were evaluated after 7 and 90 days. RESULTS: there were no
statistically significant differences between the inflammatory cell responses of
control and either dosage groups of Catalase at the 7-day evaluation period.
However, after 90 days, better tissue healing was observed in the teeth treated
with Catalase, resulting in significant differences with the control group.
CONCLUSIONS: it can be concluded that the results of this study encourage the
topical use of antioxidant Catalase as a pulp-capping agent. However, further
studies are required to determine optimal antioxidant dosages.
PMID- 10785300
TI - A new screening test for toxicity testing of dental materials.
AB - OBJECTIVES: The development of a micro plate assay for cytotoxicity testing of
dental materials based on a bioassay using brine shrimp larvae (artemia salina)
as sensitive organisms. METHODS: Brine shrimp larvae are commonly used for
cytotoxicity assays in pharmacology. These larvae are sensitive to toxic
substances. The ratio between dead larvae (no motility) and living larvae (high
motility) in comparison to a control without any toxic substances is used to
estimate the toxicity of the test solutions. The test materials (Arabesk((R)),
Solitaire((R)), Pertac((R)) II, Tetric((R)), Herculite((R)) and the compomer
materials Dyract((R)), Hytac((R)), Compoglass((R))) were polymerized and
consecutively milled. After incubation of 1g in 4ml distilled water at 37 degrees
C for 48h, the solid materials were separated by centrifugation. The solutions
were equibrilated with NaCl to a salt content of 25g/l. Aliquots of 200microl
were distributed in eight micro wells and 50microl of a artemia salina containing
(n=8-14) solution were added to each well. As controls eight wells with 250microl
salt solution containing a comparable number of brine shrimp were used. At
baseline, after 2, 5, 24 and 48h, the dead shrimp were counted using a stereo
microscope. Finally all shrimps were sacrificed using Na-acid (5%) and counted to
get the number of shrimps per well. RESULTS: All compomers and Solitaire caused
100% brine shrimp lethality after 24h and showed significantly (p<0.01, signed
rank test) higher toxicities than the remaining composites. With the exception of
Pertac II, all composites showed significantly higher toxic values than the
control. Pertac II did not show any differences from the controls used.
CONCLUSIONS: This new technique has some advantages for toxicity testing of
restorative materials, because it can quickly be carried out at low costs. The
disadvantage is the high quantity of material used and the low sensitivity.
PMID- 10785301
TI - Effect of region and dentin perfusion on bond strengths of resin-modified glass
ionomer cements.
AB - OBJECTIVES: The purpose of this study was to evaluate the hypothesis that
regional differences and pulpal pressure would significantly affect bond
strengths of resin-modified glass ionomer cements to dentin. METHODS: Twenty-six
extracted caries-free human third molars were ground to expose middle dentin and
were randomly divided into two groups for bonding: no pulpal pressure and pulpal
pressure of 15cm H(2)O. Fuji II LC, Vitremer, or Photac-Fil Quick were applied to
the previously pre-treated surfaces and light-cured as recommended by the
manufacturers. After immersion in water at 37 degrees C for 24h, the teeth were
sectioned to 0.7mm thick slabs, divided into pulp horn, center, and peripheral
regions according to visual criteria, and trimmed along the bonded interface for
microtensile bond test to a cross-sectional area of 1mm(2). The slabs were
subjected to tensile forces and the data analyzed using ANOVA and Fisher's PLSD
at the 95% level of confidence. RESULTS: For Fuji II LC, bond strengths to the
pulp horn regions were significantly lower than those to the other regions
independent of pulpal pressure (p<0.05). On the other hand, regional bond
strengths were not observed for Vitremer and Photac-fil Quick 0.05). CONCLUSIONS:
Pulpal pressure had a stronger influence on bond strengths and failure modes of
resin-modified glass ionomers than regional differences of the substrate.
PMID- 10785302
TI - Analysis of composite type and different sources of polymerization light on in
vitro toothbrush/dentifrice abrasion resistance.
AB - OBJECTIVES: This study examined toothbrush/dentifrice abrasion of a photo
activated prosthetic composite (dentin and enamel variations) for the purpose of
evaluating the influence of polymerization sources on abrasive wear. METHODS: A
photo-activated prosthetic composite material (Artglass) was assessed. Dentin and
enamel variations were polymerized using a proprietary photo-curing unit with two
xenon stroboscopic lamps (UniXS), and other enamel specimens were polymerized
either with a laboratory photo-curing unit with three fluorescent tubes or with a
high intensity unit with two metal halide lamps. All specimens were stored in
water for 14days and subjected to toothbrush/dentifrice abrasion (350g vertical
load) using an abrasive slurry (Colgate Fluoriguard) and a toothbrush (Oral-B
40). The amount of vertical loss and the surface roughness of the specimens after
20,000 strokes were determined by profilometer. Average values of groups of five
specimens were compared using analysis of variance (ANOVA) and Sheffe's S
intervals (p<0.05). RESULTS: When polymerizing with the proprietary unit, the
abrasion and surface roughness of the enamel material required respective means
of 34.08microm (+/-3.66) and 1.00microm (+/-0.08), and the those of the dentin
material required means of 42.02microm (+/-5.62) and 1.23microm (+/-0.20). Both
abrasion and surface roughness after toothbrushing of the enamel material were
significantly smaller than were those of the dentin material. The abrasion of
specimens polymerized with the metal halide unit required a mean of 23.89microm
(+/-6.17) and demonstrated minimal wear. CONCLUSIONS: The use of a high intensity
metal halide photo-curing unit effectively enhanced the abrasion resistance of
the composite. Surfaces of restorations should be covered with the enamel
material in order to achieve smoothness and wear resistance.
PMID- 10785303
TI - Microtensile bond strengths of glass ionomer (polyalkenoate) cements to dentine
using four conditioners.
AB - OBJECTIVES: The purpose of this study was to measure the microtensile bond
strengths of three glass ionomer cements to dentine (Photac-Fil Quick; Fuji II
LC; Fuji IX GP) using four different conditioners (Ketac Conditioner; Dentin
Conditioner; Cavity Conditioner; and an experimental conditioner, K-930).
METHODS: Superficial occlusal dentine of extracted human third molars was
exposed, finished with wet 600-grit silicon carbide paper, and each of the above
glass ionomer cements bonded using the four conditioners according to the
manufacturers' instructions. After 24h in tap water at 37 degrees C, the teeth
were sectioned to obtain 3-4 bar-shaped specimens. Ten specimens were prepared
for each group and shaped to an hour-glass form of (1.2+/-0.02)mm diameter. The
specimens were mounted in a jig and stressed in tension at a crosshead speed of
1mm/min until failure. The mean bond strengths were calculated and compared using
one-way ANOVA and LSD tests, and the fracture modes were examined by scanning
electron microscopy. RESULTS: Mean microtensile bond strengths for Photac-Fil
Quick were not significantly different from Fuji II LC for each of the
conditioners used. However, the bond strengths for Photac-Fil Quick were
significantly greater than Fuji II LC when no conditioner was applied. Mean
microtensile bond strengths of conditioned specimens of Fuji II LC were
significantly greater than non-conditioned specimens. Mean microtensile bond
strengths of non-conditioned specimens of Fuji IX GP were not significantly
different from conditioned specimens. The fracture mode of all specimens
demonstrated mostly cohesive failure within the cement. SIGNIFICANCE: The use of
surface conditioners resulted in improvement in bond strength of Fuji II LC,
while Photac-Fil Quick and Fuji IX GP showed no difference.
PMID- 10785304
TI - Effect of finishing technique on the microleakage and surface texture of resin
modified glass ionomer restorative materials.
AB - PURPOSE: The purpose of this study was to evaluate the effects of wet and dry
finishing/polishing procedures on the microleakage and surface texture of resin
modified glass ionomer (RMGI) restorative materials. MATERIALS AND METHODS: Class
V cavity preparations were made at the cemento-enamel junction (CEJ) on the
buccal and lingual surface of 30 extracted human molars. The teeth were restored
in three groups of 10 (20 preparations in each group) using Fuji II LC and
Vitremer, both RMGIs, and Fuji II, a capsulated conventional glass ionomer cement
(control). One restoration per tooth was finished/polished with copious
applications of water and the other was finished/polished without water. All
restorations were finished/polished using a sequence of four abrasive disks.
Finishing/polishing was initiated according to manufacturers' instructions
immediately after light-curing Fuji II LC and Vitremer, and 15min after placement
for Fuji II. The specimens were thermocycled and subjected to a silver nitrate
leakage test. Each tooth was sectioned buccolingually and examined with an
optical microscope at 40x to determine the extent of microleakage at enamel and
dentin margins. The data were subjected to a non-parametric statistical analysis.
To evaluate surface roughness after polishing, three disks each of Vitremer and
Fuji II LC were fabricated in Teflon molds. One disk of each material was not
finished/polished (control). The others were finished/polished using Sof-Lex
abrasive disks. One specimen of each material was kept wet during all
finishing/polishing procedures, while the other was kept dry. Atomic force
microscopy was used to determine the average roughness (R(a)) of the specimens.
RESULTS: For each material, microleakage at the enamel margin was very slight.
Leakage of the conventional glass ionomer Fuji II was severe at dentin margins.
Statistical analysis indicated that both Vitremer and Fuji II LC had
significantly less leakage than Fuji II, and that Vitremer had significantly less
leakage than Fuji II LC (p<0.05). Leakage at enamel margins was significantly
less than at dentin margins. Differences related to wet and dry polishing were
not statistically significant. Profilometry data indicated that polished
specimens were rougher than those cured against a Mylar strip. Wet polishing
created greater surface roughness than dry polishing. CONCLUSIONS: RMGIs rather
than conventional glass ionomers should be used in Class V cavity sites to allow
immediate finishing and to reduce the incidence of microleakage. Dry finishing of
RMGIs with abrasive disks is recommended because it produces a smoother surface
and does not contribute to microleakage. However, wet finishing of conventional
glass ionomers is still recommended to avoid desiccation.
PMID- 10785314
TI - Connectance in Sorghum development: beyond the genotype-phenotype duality.
AB - Connectance, the level of linkage between organs, was measured in different lines
of Sorghum bicolor during their reproductive development. It was compared with
expression of characters, their level of variability and their heritability. A
negative relationship is observed between connectance and heritability. Further
results indicate that connectance does not simply introduce a noise factor in
expression of a pre-existing information, but that it is directly involved in
phenotypic expression and plasticity. Connectance appears as partly determined by
the nature and dynamics of the network of relationships. It is concluded that the
phenotype is not restricted to the deterministic expression of a pre-existing
program, the genotype. Morphogenesis also involves another dimension, self
organized, which confers reliability, stability and adaptability to the
developmental processes. The complex interactions between these two dimensions
and their evolutionary consequences are discussed.
PMID- 10785315
TI - Three-dimensional architectures grown by simple 'stigmergic' agents.
AB - A simple model of multi-agent three-dimensional construction is presented. The
properties of this model are investigated. Based on these properties, a fitness
function is defined to characterize the structured patterns that can be generated
by the model. The fitness function assigns a value to each pattern. The choice of
the fitness function is validated by the fact that human observers tend to view
patterns with high (resp. low) fitness as structured (resp. unstructured). A
genetic algorithm based on this fitness function is used to explore the space of
possible patterns. The genetic algorithm is able to make use of sub-modules of
existing patterns and recombine them to produce novel patterns, but strong
epistatic interactions among genes make the fitness landscape rugged and prevent
more complex patterns from being produced.
PMID- 10785316
TI - Autonomous choice in the learning process of a turtle Chinemys reevesii.
AB - We studied animal's learning of spatial discrimination in an experimental
environment. Turtles, Chinemys reevesii, were employed for the study. We focused
on two independent aspects: (1) turtle's success rate in the task, which is the
most common criterion to estimate the ability of the animals, and (2) the
statistical properties of the time interval of the task, which is independent on
the spatial criterion. For a statistical analysis, we employed the scheme of
power law distributions which was recently used to estimate animal behaviors in
relation to the idea of the fractal. We addressed the basic problem of whether
these two criteria, or any other criteria for this matter, could or could not
exclude an observer who studies the animal behavior. To demonstrate
inseparability of an observer and the object, we conducted three different
learning experiments: (1) complete spatial discrimination, (2) incomplete spatial
discrimination, (3) another, different, complete discrimination, in this order.
The incomplete one was taken to mean incomplete only for an observer. Our
experiments reveal that the same result (success rate) was perceived differently
by the animal if the attitude of the observer to the experiments differed. This
observation comes to suggest that the notion of autonomous choice on the part of
an animal is contingent upon the inseparability between an observer and the
object.
PMID- 10785317
TI - Studies into abstract properties of individuals. IV. Emergence In different aged
needle primordia of Douglas fir.
AB - Young, middle aged and older Douglas fir needle primordia, as determined by
distance from the apical meristem, were measured and analyzed to compare levels
and patterns of emergence related to development time. Emergence was seen in the
differently aged needle primordia, generally most noticeable in the oldest and
the least apparent in the youngest. There was also a negative relationship
between variation in size and degree of emergence, and a positive one with
variation in organization. The increasing level of emergence that appears with
age can be related to the continual expression of information and the concomitant
increase in complexity that marks ontogeny and is the result of diverging
developmental trajectories. The histogenetic events seen in ontogeny can be
interpreted as 'clocks' generating local time through the interactions among
cells and tissues that make up the needle primordia. Emergent properties are
manifested through the local events that mark ontogeny, and also through the
expression of phylogenetic information, or the local expression of global
(historical) levels of organization.
PMID- 10785318
TI - Summer school on bioinformatics: information systems and network analysis of gene
regulation and metabolism.
PMID- 10785319
TI - Classical swine fever. Proceedings of a symposium. Birmingham, England, July 9
10, 1998.
PMID- 10785320
TI - Introduction to classical swine fever: virus, disease and control policy.
AB - Classical swine fever virus is a spherical enveloped particle of about 40-60 nm
in diameter with a single stranded RNA genome of about 12,300 bases with positive
polarity, classified as a pestivirus within the family Flaviviridae. Natural
hosts are domestic and wild pigs. The virus causes one of the most severe
diseases in pigs world wide with grave economic consequences. The clinical
picture of classical swine fever is variable, depending on the age of the
affected animals and viral virulence. The virus is well characterised and
reliable laboratory diagnostic procedures are available. In many parts of the
world live attenuated vaccines are being used as a safe and efficient
prophylactic tool. However, in EU Member States and several other countries
vaccination is prohibited and CSF is controlled by a strict stamping out policy.
In order to overcome the disadvantages of conventional vaccination inactivated
marker vaccines have been developed that enable the distinction between
vaccinated and infected animals. Whether these vaccines will be accepted as an
additional tool in the framework of the stamping out policy is not yet decided.
PMID- 10785321
TI - Classical swine fever: the global situation.
AB - A historical and current perspective is given of classical swine fever and its
impact on pig production in different regions of the world. Data were obtained
from a variety of sources including returns to the Office International des
Epizooties, official government reports, other published material and local
information through personal contacts. The disease has been recognized for about
170 years and efforts to control it by official intervention began in the
nineteenth century. Despite this it remains a lingering problem in many parts of
the world where it has both, an economic impact on swine production and a
constraining effect on trade due to the measures necessary to prevent spread.
PMID- 10785322
TI - Incidence and control of CSF in wild boar in Europe.
AB - The possibility that Classical swine fever (CSF) persists in a wild boar
population has been shown in some areas of France, Germany and Italy in recent
years. Availability of susceptible animals and frequency of infectious contacts
are major variables influencing disease evolution. In the European Union (EU)
measures to control CSF in the wild boar are enforced in the framework of Council
Directive 80/217/EEC, including eradication plans that must be enforced taking
account of the local epidemiological situation. Oral vaccination experiments are
being carried out in Germany, which have not led to final conclusions concerning
the efficacy of vaccination in eradicating disease.
PMID- 10785323
TI - Structure and presentation of a World Wide Web database of CSF virus isolates
held at the EU reference laboratory.
AB - A computerized database was generated with the epidemiological data of more than
600 CSF virus strains and isolates kept in the EU Reference Laboratory for
Classical Swine Fever in Hanover. In addition, as sequence data from defined
regions of the genome are increasingly being used for genetic typing of new
isolates and are thus being published, it was decided to integrate them into the
database. In order to make the epidemiological and the sequence data available to
other laboratories through the World Wide Web, a searchable web interface was
programmed, which can be accessed using an Internet browser like Netscape or
Internet Explorer. The possibility to exchange data via the web has the potential
to increase our knowledge concerning genetic and epidemiological links between
outbreaks worldwide.
PMID- 10785324
TI - Genetic typing of classical swine fever virus.
AB - Three regions of the classical swine fever virus (CSFV) genome that have been
widely sequenced were compared with respect to their ability to discriminate
between isolates and to segregate viruses into genetic groups. Sequence data-sets
were assembled for 55 CSFVs comprising 150 nucleotides of the 5' non-translated
region, 190 nucleotides of the E2 envelope glycoprotein gene and 409 nucleotides
of the NS5B polymerase gene. Phylogenetic analysis of each data-set revealed
similar groups and subgroups. For closely related viruses, the more variable or
larger data-sets gave better discrimination, and the most reliable classification
was obtained with sequence data from the NS5B region. No evidence was found for
intertypic recombination between CSFVs. A larger data-set was also analysed
comprising 190 nucleotides of E2 sequence from 100 CSFVs from different parts of
the world, in order to assess the extent and global distribution of CSFV
diversity. Additional groups of CSFV are evident from Asia and the nomenclature
of Lowings et al. (1996) [Lowings, P., Ibata, G., Needham, J., Paton, D., 1996.
J. Gen. Virol. 77, 1311-1321] needs to be updated to accommodate these. A
tentative assignment, adapting rather than overturning the previous nomenclature
divides CSF viruses into three groups with three or four subgroups: 1.1, 1.2,
1.3; 2.1, 2.2, 2.3; 3.1, 3.2, 3.3, 3.4. The expanding data-base of CSFV sequences
should improve the prospects of disease tracing in the future, and provide a
basis for a standardised approach to ensure that results from different
laboratories are comparable.
PMID- 10785325
TI - Classical swine fever virus: a ring test to evaluate RT-PCR detection methods.
AB - Six laboratories participated in an exercise to compare the sensitivity and
specificity of RT-PCR tests for the detection of classical swine fever virus
(CSFV). Two sets of coded samples were prepared by serial dilution of positive
samples and then distributed to each of the laboratories. One set comprised 34
samples of random primed cDNA. These had been synthesised from viral RNA
representative of seven different genetic subtypes of CSFV. The other set
comprised 40 clinical samples containing tonsil, spleen, whole blood or serum
from a pig that had been experimentally infected with CSFV. Each laboratory
tested the samples using one or more PCR/RT-PCR tests that they were accustomed
to using. The methods and results of the laboratories were compared with one
another. The RT-PCR results obtained from testing the clinical samples were also
compared with those obtained by virus isolation and antigen ELISA.ELISA. Both RT
PCR and RT-nested PCR appeared to give some false positive results. Several of
the PCR tests appear suitable in terms of specificity and sensitivity. Further
trials are necessary to compare results when the same test is performed by
different laboratories, and to show that improved control procedures can
eliminate problems due to false positive reactions.A limited comparison of
extraction and reverse transcription procedures showed similar results in each of
three participating laboratories, even though the methods were not standardised.
PMID- 10785326
TI - Survival and inactivation of classical swine fever virus.
AB - Classical swine fever virus, like many enveloped viruses, may be regarded as
moderately fragile. It shows a short but variable survival time in the
environment, depending on physical conditions, but may remain viable for
prolonged periods in favourable circumstances as found, for example, in stored
meat. Published information is reviewed on the survival time of the virus under a
variety of physical and chemical conditions, including the variable influence of
environmental factors. The principles of virus inactivation by heat, pH or
chemicals are discussed, with a consideration of the principles of containment
for laboratories working with the virus.
PMID- 10785327
TI - The 1997-1998 epidemic of classical swine fever in the Netherlands.
AB - In 1997, the pig husbandry in the Netherlands was struck by a severe epidemic of
classical swine fever (CSF). During this epidemic 429 CSF-infected herds were
depopulated and approximately 1300 herds were slaughtered pre-emptively. In
addition millions of pigs of herds not CSF-infected were killed for welfare
reasons (over crowding or overweight). In this paper, we describe the course of
the epidemic and the measures that were taken to control it. The first outbreak
was detected on 4 February 1997 in the pig dense south-eastern part of the
Netherlands. We estimate that CSF virus (CSFV) had already been present in the
country by that time for 5-7 weeks and that the virus had been introduced into
approximately 39 herds before the eradication campaign started. This campaign
consisted of stamping-out infected herds, movement restrictions and efforts to
diagnose infected herds as soon as possible. However, despite these measures the
rate at which new outbreaks were detected continued to rise. The epidemic faded
out only upon the implementation of additional measures such as rapid pre-emptive
slaughter of herds in contact with or located near infected herds, increased
hygienic measures, biweekly screening of all herds by veterinary practitioners,
and reduction of the transportation movements for welfare reasons. The last
infected herd was depopulated on 6 March 1998.
PMID- 10785328
TI - Laboratory experience during the classical swine fever virus epizootic in the
Netherlands in 1997-1998.
AB - From February 1997 till May 1998 the national reference laboratory for classical
swine fever (CSF) in the Netherlands was confronted with millions of samples
taken from pigs during an outbreak of CSF in a pig dense region. In a limited
period major logistic problems needed to be solved regarding the processing of
samples and information at the laboratory facilities. In total over 2.3 million
samples were examined by different CSF diagnostic methods. The majority
(approximately 2.1 million) of these samples were blood samples which were tested
for CSF serum antibody in a semi-automated ELISA. Approximately 166,000 samples
were examined for the presence of CSF virus or viral antigen. Automated
preparation and testing of blood samples for CSF serum antibody, the obligatory
identification and registration system of pig holdings and the computerised
laboratory management system made it possible to process the huge amount of
samples and information presented in a limited period. The majority of the test
results was sent to the veterinary authorities via e-mail or a computerised fax
system. Of the 429 outbreaks 82% were detected via a direct immunofluorescence
technique performed on cryostat sections of the tonsil. The sampling of
clinically suspected pigs ('guided' sampling) for this diagnostic method provided
rapid positive and negative results and thus played a paramount role during the
eradication campaign. Serological surveys identified 13.5% of the infected pig
holdings: such surveys proved very effective in the screening of holdings which
were subjected to restrictions (protection or surveillance zones) for many
months. Virus isolation performed on different types of samples detected 4. 5% of
the infected pig holdings. In conclusion, analysis of data collected in the
laboratory and epidemiological analysis should result in an improved eradication
plan for the future control of outbreaks of CSF in the Netherlands supported by
optimised CSF diagnostic methods.
PMID- 10785329
TI - Development of a classical swine fever subunit marker vaccine and companion
diagnostic test.
AB - The development of a classical swine fever (CSF) subunit marker vaccine, based on
viral envelope glycoprotein E2, and a companion diagnostic test, based on a
second viral envelope glycoprotein E(RNS), will be described. Important
properties of the vaccine, such as onset and duration of immunity, and prevention
of horizontal and vertical transmission of virus were evaluated. A single dose of
the vaccine protected pigs against clinical signs of CSF, following intranasal
challenge with 100LD(50) of virulent classical swine fever virus (CSFV) at 2
weeks after vaccination. However, challenge virus transmission to unvaccinated
sentinels was not always completely inhibited at this time point. From 3 weeks up
to 6 months after vaccination, pigs were protected against clinical signs of CSF,
and no longer transmitted challenge virus to unvaccinated sentinels. In contrast,
unvaccinated control pigs died within 2 weeks after challenge. We also evaluated
transmission of challenge virus in a setup enabling determination of the
reproduction ratio (R value) of the virus. In such an experiment, transmission of
challenge virus is determined in a fully vaccinated population at different time
points after vaccination. Pigs challenged at 1 week after immunization died of
CSF, whereas the vaccinated sentinels became infected, seroconverted for E(RNS)
antibodies, but survived. At 2 weeks after vaccination, the challenged pigs
seroconverted for E(RNS) antibodies, but none of the vaccinated sentinels did.
Thus, at 1 week after vaccination, R1, and at 2 weeks, R=0, implying no control
or control of an outbreak, respectively. Vertical transmission of CSFV to the
immune-incompetent fetus may lead to the birth of highly viraemic, persistently
infected piglets which are one of the major sources of virus spread. Protection
against transplacental transmission of CSFV in vaccinated sows was, therefore,
tested in once and twice vaccinated sows. Only one out of nine once-vaccinated
sows transmitted challenge virus to the fetus, whereas none of the nine twice
vaccinated sows did. Finally, our data show that the E(RNS) test detects CSFV
specific antibodies in vaccinated or unvaccinated pigs as early as 14 days after
infection with a virulent CSF strain. This indicates that the E2 vaccine and
companion test fully comply with the marker vaccine concept. This concept implies
the possibility of detecting infected animals within a vaccinated population.
PMID- 10785330
TI - Economic aspects of the control of classical swine fever outbreaks in the
European Union.
AB - A framework for assessing the economic impact of classical swine fever (CSF) is
presented, including an analysis of direct and indirect costs. Direct costs are
divided into calculated costs, expenditure on control measures (payable costs)
and costs due to financial transfers. The economic impact of current control
strategies is described using practical examples. In most cases, the largest part
of the direct costs is associated with transport standstill measures, of which
approximately 45% are calculated costs. Alternative strategies, still based on
non-vaccination offer a potential for reducing these costs. Various economic
aspects of emergency vaccination are described using as an example, a
hypothetical optimistic CSF case. In order to explore the impact of applying
emergency vaccination using marker vaccines, additional research is required
using simulation modelling. This research should include an assessment of risk
and uncertainty with respect to calculating the epidemiological impact and the
direct costs.
PMID- 10785331
TI - Oral immunisation of wild boar against classical swine fever: evaluation of the
first field study in Germany.
AB - The effectiveness of oral immunisation of wild boar against classical swine fever
(CSF) was studied in a field trial in Lower Saxony for two years, from 1993 to
1995. This field study was performed in an area of ca. 270 km(2)50% of young
boars did not feed on vaccine baits nor become immunised. Therefore, an intensive
hunting of this age group is a necessary adjunct to the use of oral vaccination.
After the third immunisation period, no virus was detected in the areas where
oral immunisation took place.
PMID- 10785332
TI - Epidemiology of HIV infection in the newborn.
AB - Vertical transmission of HIV infection can take place in utero, during delivery
and postnatally through breastfeeding, with about three-quarters of infections
occurring around the time of delivery in non-breastfeeding populations. In
Europe, in the absence of specific interventions, the vertical transmission rate
was 15-20%. High maternal load is the major risk factor for both intra-uterine
and intra-partum mother-to-child transmission. Prematurity is the most common
adverse neonatal outcome associated with maternal HIV infection. Earlier
diagnosis of paediatric HIV infection than previously available is now possible
with virological tests, particularly HIV DNA polymerase chain reaction. An
estimated one fifth of infected children will have been diagnosed with AIDS or
have died by 12 months of age, rising to a third by 6 years of age. Surgical and
therapeutic interventions are effective in reducing vertical transmission risk,
in addition to the avoidance of breastfeeding. Caesarean section delivery before
labour and before rupture of membranes approximately halves the risk of
transmission, while prophylactic zidovudine therapy according to the ACTG076
regimen reduces transmission by up to two-thirds, transmission is reduced even
further with both interventions. Trials of short-course zidovudine regimens show
their effectiveness in reducing vertical transmission, in breastfeeding and non
breastfeeding populations. Nevirapine has been shown to be significantly more
effective than short course zidovudine regimens in breastfeeding populations, but
is still under evaluation in non-breastfeeding populations additionally receiving
routine anti-retroviral prophylaxis. Reports of a small number of serious adverse
events in uninfected children exposed in utero or neonatally to antiretroviral
therapy need further investigation. Trials of vitamin A supplementation to reduce
vertical transmission have had negative results, while the effectiveness of
vaginal lavage and passive immune therapy in reducing vertical transmission
remains uncertain.
PMID- 10785333
TI - Lower alkaline phosphatase activity and occurrence of an abnormal hybrid
intestinal/tissue non-specific isoform in Down's syndrome amniotic fluids.
AB - Quantitative and qualitative analysis of alkaline phosphatases (AP) was performed
on amniotic fluid in 59 normal pregnancies and 14 Down's syndrome (DS)
pregnancies at 16, 18 and 19 weeks of gestation. In DS cases, intestinal and
placental isoenzyme levels were significantly reduced (P<0.001) and the AP
electrophoretic pattern was seen to be modified on polyacrylamide gel
electrophoresis. A unique component was detected. After extraction and
purification of the abnormal isoenzyme, peptide fragments obtained after cyanogen
bromide cleavage indicated a hybrid heterodimeric AP composed of intestinal and
tissue non-specific subunits, as evaluated by SDS polyacrylamide gel
electrophoresis.
PMID- 10785335
TI - Simplified screening for organic acidemia using GC/MS and dried urine filter
paper: a study on neonatal mass screening.
AB - A simplified method for organic acidemia screening using GC/MS, the urease/direct
method, is now available. To establish a practical screening system for organic
acidemias, we studied the usefulness of dried urine filter paper (filter paper
urine) and the application of a personal computer-based system of automated
metabolic profiling and interpretation (automated system) that we earlier
developed. In a comparison of filter paper urine with liquid urine, creatinine
levels ranging from 4.6 to 122.5 mg/dl, showed an excellent correlation
(r=0.9554), when the volumes of blotted urine and distilled water soaked were the
same. Recovery of all 17 compounds except for citrate was similar between liquid
and filter paper urine. CV values of 22 compounds tested ranged from 5.5 to 22.4%
in the liquid urine, and from 7.7 to 29.8% in the filter paper urine. The CV
values in stable isotope dilution analysis were much smaller in all nine
compounds tested. As to the stability of compounds, the percentage changes to
values at day 0 were within about +/-25% on day 28. We compiled GC/MS data,
including methylene unit values, quantifying and confirming ions of 163 different
organic acids and others, to use the automated system. We analyzed specimens from
55 patients with 17 different metabolic disorders. In 54 of the 55 specimens, the
correct diagnosis was successfully indicated. Neonatal mass screening for organic
acidemias warrants ongoing attention using this simplified method and filter
paper urine.
PMID- 10785334
TI - The distribution of receptors for the pro-inflammatory cytokines interleukin (IL)
6 and IL-8 in the developing human fetus.
AB - Interleukin-6 receptor alpha (IL-6R) and interleukin-8 receptor (IL-8RB) are
widely expressed in adult human and murine tissues. Little is known about the
expression of these receptors and the function of their ligands in the developing
human fetus. OBJECTIVES: To determine the tissue distribution and cellular
expression of IL-6R and IL-8RB in the developing human fetus. METHODS: Reverse
transcription-PCR and immunohistochemical staining were performed on brain,
spinal cord, eye, heart, lung, liver, spleen, adrenal, kidney, intestine, and
placenta from fetuses of 8 and 16+/-2 weeks post-conception. RESULTS: IL-6R and
IL-8RB mRNA were detected in all tissues tested at both time points.
Immunoreactivity to anti-IL-6R antibody was present on neurons, and in neuropil
of the brain, as well as in bone marrow, bronchi, hepatocytes, zona glomerulosa
of the adrenal, glomerular cells in kidney, spleen, and placental trophoblasts.
Cell-specific expression for IL-8RB in the central nervous system was localized
to specific groups of neurons and astrocytes in the brain and spinal cord,
including the neural retina. In somatic organs IL-8RB was detected in bone
marrow, myocardiocytes, bronchiolar epithelial cells, hepatocytes, cells of the
zona glomerulosa and the zona fasciculata of the adrenal, the collecting system
of the kidney, enterocytes of the bowel and in placental cells. CONCLUSION: The
widespread expression of these cytokine receptors suggests a nonhematopoietic
role for their ligand in the developing fetus.
PMID- 10785336
TI - Dynamic changes in the middle cerebral artery perfusion in normal full-term human
fetuses in relation to the timing of behavioral state.
AB - Our aim is to evaluate serial changes in normal full-term fetal cerebral
circulation according to the behavioral states. Flow velocity waveforms in the
middle cerebral artery and fetal heart rate (FHR) were well recorded in ten of 19
cases by pulsed Doppler ultrasonography and actocardiography over 45 min,
respectively. Behavioral states were classified as resting or active phase by FHR
patterns. Resistance indices (RIs) were calculated every 5 s as an average of two
consecutive waveforms, and median RI was chosen in each 2-min segment. In order
to evaluate changes in median RI from active-to-resting transition to resting-to
active one statistically, differences in RI between two 2-min segments were
examined using Mann-Whitney U-test. As a result, median RI was decreased to the
minimum one in the active-to-resting transition for 12 min in all cases:
significant decrease to the 2-min segment with the minimum one (P<0.01). Various
types of increase to the maximum median RI during resting phase followed the
minimum one: significant increase from the 2-min segment with the minimum one to
that with the maximum one in all cases (P<0.001 in eight cases, P<0.01 in two
cases). Thereafter, median RI was decreased from the end of resting phase in the
resting-to-active transition for 12 min in all cases: significant decrease from
the last 2-min segment of resting phase in all cases (P<0.01). We reveal that
fetal cerebral circulation changes dynamically in relation to the timing in each
behavioral state.
PMID- 10785337
TI - Detectable interleukin-10 and interleukin-8 in bronchoalveolar lavage fluid from
preterm infants ventilated for respiratory distress syndrome
PMID- 10785338
TI - Effect of postnatal age and beta(3)-adrenergic agonist (Zeneca D7114)
administration on uncoupling protein-1 abundance in the lamb
PMID- 10785339
TI - Effect of fetal number on prolactin receptor abundance in perirenal adipose
tissue of neonatal lambs
PMID- 10785340
TI - The cognitive processes of doctors and nurses in the interpretation of
physiological monitoring data in the neonate
PMID- 10785341
TI - Methodological issues relating to surfactant protein a measurement in
bronchoalveolar lavage fluid from preterm infants with respiratory distress
syndrome
PMID- 10785343
TI - Investigation of the role of lung liquid in the pathogenesis of lung disease in
the preterm infant using magnetic resonance imaging
PMID- 10785342
TI - Induction of retinopathy in newborn rats using a clinically relevant oxygen
profile
PMID- 10785344
TI - W.D. Hamilton (1936-2000).
PMID- 10785345
TI - Hormonal correlates of paternal responsiveness in new and expectant fathers.
AB - Little is known about the physiological and behavioral changes that expectant
fathers undergo prior to the birth of their babies. We measured hormone
concentrations and responses to infant stimuli in expectant and new fathers
living with their partners to determine whether men can experience changes that
parallel the dramatic shifts seen in pregnant women. We obtained two blood
samples from couples at one of four times before or after the birth of their
babies. After the first sample, the couples were exposed to auditory, visual, and
olfactory cues from newborn infants (test of situational reactivity). Men and
women had similar stage-specific differences in hormone levels, including higher
concentrations of prolactin and cortisol in the period just before the births and
lower postnatal concentrations of sex steroids (testosterone or estradiol). Men
with more pregnancy (couvade) symptoms and men who were most affected by the
infant reactivity test had higher prolactin levels and greater post-test
reduction in testosterone. Hormone concentrations were correlated between
partners. This pattern of hormonal change in men and other paternal mammals, and
its absence in nonpaternal species, suggests that hormones may play a role in
priming males to provide care for young.
PMID- 10785346
TI - Does paternal uncertainty explain discriminative grandparental solicitude? A
cross-cultural study in Greece and Germany.
AB - Recent research on kin investment as a reproductive strategy is based on the idea
that differences in grandparental caregiving directly reflect degrees of
differential grandpaternal versus grandmaternal certainty. In a cross-cultural
study in Greece and Germany, 544 subjects (318 Greeks, 208 Germans, 18 of other
origins) were asked for an assessment of their grandparents' (GPs') caregiving.
In Germany and urban Greece (modern Western societies), the maternal GPs were
rated as more intensive caregivers than the paternal GPs, but this was not the
case in rural Greece, where paternal GPs provided more care. However, in all
groups, grandmothers were more caring than grandfathers. Thus, contrary to
previous theory and research, these two effects must be clearly distinguished,
and may be explained by (1) more intense female caregiving in humans (as in other
viviparous mammals) and (2) a socially engendered favoring of maternal relatives
in Western industrial societies as opposed to the favoring of paternal GPs seen
in the patrilateral culture of rural Greece.
PMID- 10785347
TI - The jus primae noctis as a male power display. A review of historic sources with
evolutionary interpretation.
AB - The jus primae noctis was, in the European late medieval context, a widespread
popular belief in an ancient privilege of the lord of the manor to share the
wedding bed with his peasants' brides. Symbolic gestures, reflecting this belief,
were developed by the lords and used as humiliating signs of superiority over the
dependent peasants in the fifteenth century, a time of diminishing status
differences. Actual intercourse in the exercise of the alleged right is difficult
to prove, and there is no hard evidence to suggest that it ever actually
happened. However, the symbolic gestures can be best interpreted as a male power
display, with a basis in the psychology of coercive social dominance, male
competition, and male desire for sexual variety. Several non-European cultures
have accounts of a similar custom related to a young girl's first sexual
intercourse: ritual defloration by chiefs, priests, or strangers. This non
European custom differs from the jus primae noctis in its proximate details, but
seems from an ultimate point of view, to be in conformity with the European
evidence. In this article the origin, development, and relationship of both
customs are discussed and interpreted in light of recent evolutionary studies of
primate behavior and sexual psychology.
PMID- 10785348
TI - Sibling solidarity in a polygamous community in the USA. unpacking inclusive
fitness.
AB - This pilot study explores the degree of solidarity felt between full and half
siblings who are raised in a Mormon Fundamentalist polygamous community. The
community under study is unique in that, at the level of official culture, it
actively promotes full and half sibling solidarity through an ethos that strives
to downplay genetic differences in favor of a harmonious family living together
in one household. This community is an ideal cultural setting in which to examine
the suitability of inclusive fitness theory for understanding the factors that
promote family cohesion, sibling solidarity, and rivalry. Our main question
becomes: is the degree of sibling solidarity a manifestation of genetic closeness
or a natural byproduct of emotional closeness that arises from being raised
together? We found evidence for more solidarity between full siblings than
between half siblings. Our data suggest that, despite the force of religious
ideals, and notwithstanding the continued close physical proximity of half
siblings in the polygamous family, there is a pronounced clustering of feeling
and affection in the polygamous family that is consistent with inclusive fitness
theory.
PMID- 10785349
TI - Do attitude and area influence health? A multilevel approach to health
inequalities.
AB - This paper demonstrates an area effect on health and suggests improvements in
research practice for work in this field. We use an area classification which can
be related clearly to factors that influence the health of individuals and take
account of people's differing propensities to draw influence from their area.
Multilevel analysis demonstrates that the degree of deindustrialisation which an
area experienced in Britain, in the 1980s, has an independent association with
the health of resident individuals. A significant relationship between a person's
attitude to their community and their health is shown to be independent of
individual and area characteristics. We conclude that both individual and area
characteristics influence health.
PMID- 10785350
TI - "Happy Meals" in the Starship Enterprise: interpreting a moral geography of
health care consumption.
AB - This paper extends earlier explorations of the use of metaphor in the marketing
of the Starship Children's Hospital in Auckland, New Zealand, by examining
controversy surrounding the opening of an in-hospital McDonalds fast-food outlet.
The golden arches have become a key element of many children's urban geographies
and a potent symbol of the corporate colonisation of the New Zealand landscape.
In 1997 a minor moral panic ensued when a proposal was unveiled to open a
McDonald's restaurant within the Starship. Data collected from media coverage,
advertising and interviews with hospital management are analysed to interpret
competing discourses around the issue of fast food within a health care setting.
We contend that the introduction of a McDonald's franchise has become the
hospital's ultimate placial icon, adding ambivalence to the moral geography of
health care consumption. We conclude that arguments concerning the unhealthy
nature of McDonald's food obscure deeper discourses surrounding the unpalatable
character of the health reforms, and a perceived 'Americanisation' of health care
in New Zealand.
PMID- 10785351
TI - Contours of coping: mapping the subject world of long-term illness.
AB - Medical geography has evolved from studying 'dots on maps to embodied subjects'.
Involving the acknowledgement of new territories and identities, this has taken
place against a backdrop of wider shifts in understanding health and illness.
This paper suggests geographers are well placed to develop their existing skills
of spatial exploration in order to map out these new territories. Whilst 'the
map' has recently suffered from bad press, as a selective, misleading
representation, this paper demonstrates it can be resurrected as a less sinister
tool to aid our understanding of situated health experiences.
PMID- 10785352
TI - Preferred drinking locations of Scottish adolescents.
AB - A sample of Scottish schoolchildren (N=1240) were asked a series of questions
about their consumption of alcoholic beverages. Those who had consumed alcohol
were asked about the circumstances of their last drinking occasion. That is, what
alcoholic drink(s) they consumed, how they obtained this alcohol and where they
were when they drank it. This was done with the intention of quantifying the
extent of under-age drinking in different settings. The results presented in this
paper indicate a continuum of drinking styles between what might be regarded as
low-risk and high-risk circumstances. At one extreme, much drinking tended to
take place within the family home, usually under parental supervision. At the
opposite extreme, other alcohol consumption took place in a variety of public or
'hidden' outdoor locations. Consumption in these latter location types more often
resulted in intoxication. Also, more dangerous, high alcohol, large volume
beverages (e.g. white cider) tended to be consumed in more risky locations. The
implications of these findings are discussed in terms of the potential harm and
delinquency that can be associated with adolescent drinking.
PMID- 10785353
TI - Smokers at risk: implications of an institutionally bordered risk-reduced
environment.
AB - The paper draws on an evaluation of a workplace smoking policy implemented at
Edinburgh University to examine some implications for smokers at work. While the
objective of institutional risk-reduced environments is to diminish or control
the level of risk behaviour within, they may have unanticipated implications for
participants who are unwilling or unable to adapt. Data presented in the paper
suggest that the University smoking policy carried its own risk. That is, the
policy did not impact equally upon all members of the organisation but was
experienced as divisive in contributing towards and sustaining social
inequalities among staff.
PMID- 10785354
TI - Hans Castorp's journey-to-knowledge of disease and health in Thomas Mann's The
Magic Mountain.
AB - The paper examines Thomas Mann's novel, The Magic Mountain, to show how
imaginative literature can enhance our understanding of health in place. The
story centers on the experiences of Hans Castorp, a young bourgeois German, at a
tuberculosis sanatorium in the Swiss Alps. Three themes are examined: (1) how
knowledge about illness and health, death and life, is gained; (2) how knowledge
is arrived at through a dialectical process which reconciles seeming opposites;
and(3) how new knowledge is gained through making transitions. Lessons for health
geography are drawn from analysis of the three themes.
PMID- 10785355
TI - Mitogen-activated protein kinase kinase 4 (MKK4).
AB - The Mitogen-Activated Protein Kinase Kinase 4 (MKK4), a member of the MAP kinase
kinase family, directly phosphorylates and activates the c-Jun NH2-terminal
kinases (JNK), in response to cellular stresses and proinflammatory cytokines.
JNK is a member of the MAP kinase family and a key component of a stress
activated protein kinase signalling pathway. MKK4 mRNA is widely expressed in
adult mouse tissues, but is especially abundant in skeletal muscle and brain.
Mice lacking the MKK4 gene had abnormal hepatogenesis and died before embryonic
day 14. However cell lines lacking MKK4 have been obtained and these exhibited
defective activation of JNK and AP-1 dependent transcription activity in response
to some, but not all cellular stresses. Furthermore, T lymphocytes deficient in
MKK4 showed impaired IL-2 production following activation of the T cell receptor,
suggesting a key role of the MKK4/JNK pathway in inflammation. The mutation of
the MKK4 gene in some carcinomas indicates that it may also have a role as a
tumor suppressor. Control of the MKK4 activity and expression may provide novel
approaches to cancer or anti-inflammatory therapy.
PMID- 10785356
TI - Erythrocytic differentiation and glyceraldehyde-3-phosphate dehydrogenase
expression are regulated by protein phosphorylation and cAMP in HD3 cells.
AB - Utilisation of glucose undergoes a marked decline during erythroblastic
differentiation in the chicken. Concomitantly there is a reduction in the
expression of glucose transporter proteins and in the expression of the
glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAD). GAD activity
declines, after an initial rise, while the level of GAD mRNA decreases rapidly
after induction of differentiation. We have employed the temperature-sensitive
chicken erythroblast cell line HD3 that differentiates to the erythrocyte
phenotype at 42 degrees C in the presence of inducers (hemin and butyric acid).
The role of tyrosine and serine/threonine phosphorylation pathways were evaluated
with the phosphatase inhibitors sodium vanadate and okadaic acid, respectively.
In the presence of phosphatase inhibitors, HD3 cells underwent differentiation
and increased their synthesis of hemoglobin which is a marker protein for red
blood cells differentiation. The levels of both GAD mRNA and enzymatic activity
were increased by phosphatase inhibitors. The role of cAMP in differentiation was
also assessed. Differentiation of HD3 cells was associated with an increase in
cAMP. However the phosphodiesterase inhibitor IBMX was not a good inducer of
hemoglobin synthesis but did induce GAD mRNA and enzymatic activity. Together
these results suggest that multiple pathways (including serine/threonine
phosphorylation, tyrosine phosphorylation and elevated cAMP) are involved in the
regulation of erythroblastic differentiation, hemoglobin synthesis, GAD gene
expression and GAD activity in HD3 cells.
PMID- 10785357
TI - Ovine placental lactogen and ovine prolactin: partial proteolysis and
conformational stability.
AB - The high-resolution structure of ovine placental lactogen (oPL) and ovine
prolactin (oPRL), not yet established in detail, was probed by limited
proteolysis with the Glu-specific protease from Staphylococcus aureus V8. While
in hGH there were no cleavage sites inside of any of the four alpha-helices, the
analysis of the fragments obtained after partial proteolysis of oPL showed a site
of cleavage at the putative third helix, suggesting that this helix is partially
unwound at this point. The partial proteolysis of the rest of the molecule was
compatible with a similar folding pattern for oPL, hGH and pGH, on the basis of
the crystal structure of these last hormones. In the case of oPRL, proteolytic
cleavage occurred at Glu residues which would be located at the end of the first
helix and the beginning of the second in the hGH folding model, suggesting that
these helices are shorter in oPRL than in hGH. In order to gain further insight
on the folding of these molecules, circular dichroism and intrinsic fluorescence
measurements were used to examine the effect of denaturing conditions on oPL and
oPRL. After exposure to 6 M guanidine the unfolding of both proteins was
completely reversed upon elimination of the denaturing agent. In contrast,
exposure to pH 3.0 caused an irreversible decrease in the alpha-helical content
in both hormones, most striking for oPL, indicating that this hormone is less
stable than oPRL or hGH.
PMID- 10785358
TI - Artificial lipid-protein complexes accelerate cholesterol crystallisation in
model bile.
AB - Cholesterol gallstone disease is one of the major health problems in the world.
Substances which can affect the crystallisation of cholesterol from human bile
have been given considerable attention. Various substances (among them natural
lipid-protein complexes) have been tested for cholesterol crystallisation
promoting activity. Various artificial lipid-albumin complexes have been prepared
of which taurodeoxycholate-human serum albumin-calcium ions (TDC-HSA-Ca(2+)) had
the highest cholesterol crystallisation-promoting activity. This cholesterol
crystallisation-promoting activity is similar to that for the lipid-protein
complex isolated from native human bile [concanavalin A nonbinding fraction (con
A(-) fraction)]. Addition of cholesterol to the TDC-HSA-Ca(2+) complex further
increased the cholesterol crystallisation-promoting activity whereas the addition
of lecithin had an opposite effect. The interaction of individual components of
the TDC-HSA-Ca(2+) complex was followed using several methods. A new effect of
Ca(2+) ions (increase in the number of binding sites for bile salts) on the
interaction of TDC with HSA was found by equilibrium dialysis. Interaction of TDC
with albumin and Ca(2+) did not induce any modification of the secondary
structure of albumin. The results of fluorescence spectroscopy may indicate that
TDC is at least partially bound to not essentially fatty acid free HSA somehow
via admixtures, probably fatty acids. Difference absorption spectrum of the TDC
HSA-Ca(2+)-cholesterol complex was very similar to that of the "natural" lipid
protein complex (con A(-) fraction). From the three drugs with different albumin
binding characteristics, only sulphadimethoxin had an observable effect on the
cholesterol crystallisation-promoting activity. The action of the TDC-HSA-Ca(2+)
complex decreased significantly after the addition of sulphadimethoxin. The
addition of TDC modified the absorption spectrum of the sulphadimethoxin-HSA
Ca(2+) complex. It can be suggested that the complex of HSA with bile salts (TDC
mainly) and Ca(2+) forms a nucleation centre for cholesterol crystallisation in
bile.
PMID- 10785359
TI - Three-dimensional collagen matrices induce delayed but sustained activation of
gelatinase A in human endothelial cells via MT1-MMP.
AB - Gelatinase A, a member of the matrix metalloproteinase (MMP) family, plays an
important role during angiogenesis. It is constitutively expressed by human
endothelial cells as a latent enzyme and requires activation. Thrombin is the
only described physiological inducer of gelatinase A in human endothelial cells.
In this study, we investigated the mechanisms of gelatinase A activation by
another physiological inducer, collagen. Endothelial cells were cultured on
various ECM components for 24 h and the conditioned media were assessed for
gelatinase A activity using gelatin zymography. The results demonstrated that
type I collagen matrix specifically activates gelatinase A after 24 h in human
umbilical vein and 48 h in neonatal foreskin endothelial cells. In contrast,
thrombin activated gelatinase A after only 2 h. Activation by collagen was
sustained over long periods of time in culture (96 h). Unlike thrombin-induced
activation, collagen required active membrane type 1-MMP (MT1-MMP) on the
endothelial cell surface to activate gelatinase A. In addition, collagen-induced
activation of gelatinase A was inhibited by antibodies to the integrin receptor,
alpha(2)beta(1), but not alpha(3)beta(1). Our findings, that collagen can provide
long-term activation of gelatinase A are likely to be relevant to endothelial
cell invasion during angiogenesis.
PMID- 10785360
TI - 4E binding protein 1 expression is inversely correlated to the progression of
gastrointestinal cancers.
AB - Several components of the eukaryotic protein synthesis apparatus have been
associated with oncogenic transformation of cells. Overexpression of the
initiation factor eIF4E occurs in a variety of human tumours. The aim of this
study was to determine the level of expression and the phosphorylation state of
eIF4E and 4E-binding protein 1 (4E-BP1) in gastrointestinal cancer, and to
ascertain whether or not these factors can be used as diagnostic or prognostic
markers within this type of cancer. The eIF4E levels were significantly higher in
tumours compared with normal tissue (51. 5+/-4.4 vs 30.9+/-2.5 arbitrary units
(A.U.)/mg of protein, p<0.001). However, phosphorylated eIF4E did not change in
stomach cancers and decreased in colorectal cancers (67.1+/-1.2 vs 60.8+/-2.8%,
p<0.05). 4E-BP1 expression increased in most of the gastrointestinal cancers
studied. In addition, an inverse correlation between 4E-BP1 elevation and N and M
stages was found, showing significant higher elevation of 4E-BP1 in Node-negative
patients (11.21+/-5.74 vs 4. 03+/-2.36 n-fold, p<0.05) as well as in patients
without distant metastasis (8.41+/-3.29 vs 0.97+/-0.35 n-fold, p<0.05). These
results suggest that 4E-BP1 could function as a tumour suppressor. Moreover, the
data show a significant dephosphorylation of 4E-BP1 in gastrointestinal tumours
that correlated with an increase in the association of 4E-BP1 and eIF4E
indicating a lower availability to eIF4E to recruit to the ribosomes. Our results
support a possible role of 4E-BP1 as a prognostic factor in gastrointestinal
carcinoma.
PMID- 10785361
TI - Dynamic changes in small nuclear ribonucleoproteins of heat-stressed and
thermotolerant HeLa cells.
AB - Living organisms when subjected to various forms of environmental stress mount a
physiological response to survive the long- and short-term ill-effects of the
stress. The stress response may involve selective shut down of non-essential
metabolic activities and the repair of macromolecular damage resulting from the
stress. Messenger RNA splicing in cultured HeLa cells is one of the processes
inhibited by heat stress. Splicing is protected from such inhibition in stress
preconditioned cells that have acquired a tolerant state characterised by
increased cell survival and resistance to other environmental stresses. Stress
tolerant cells have heat shock proteins (HSPs) that had been induced by the
preconditioning process. To examine the biochemical changes induced by stress in
the splicing apparatus, we analysed the small nuclear ribonucleoprotein (snRNP)
particles associated with spliceosomes in normal, stressed, and stress tolerant
cells. We show that (a) the spliceosomal component U4/U5/U6 snRNP particle is
disassembled by heat stress into intermediates of splicing assembly, (b) prior
induction of stress tolerance protects the structural and functional integrity of
snRNPs if cells are subsequently exposed to a severe stress and (c) a novel 65
kDa protein is associated with small nuclear ribonucleoprotein particles in
stress tolerant cells.
PMID- 10785362
TI - Formation of homovanillic acid dimer by enzymatic or Fenton system - catalyzed
oxidation.
AB - Homovanillic acid is the most extensively employed reagent for the fluorometric
detection of peroxidase. However, the assays based on the determination of the
oxidation product of homovanillic acid do not allow a selective detection of the
enzyme, because chemical or physical factors can interfere with the fluorometric
determination. The aim of this work was to verify if other enzymatic or non
enzymatic systems might catalyze the homovanillic acid oxidation. The reaction
was investigated by spectrophotometric and fluorometric assays; HPLC analysis was
used to separate homovanillic acid from its oxidation product and to obtain
information on the oxidation process. The results obtained showed that soybean
lipoxygenase in the presence of hydrogen peroxide can oxidize homovanillic acid
with the formation, by an o,o'-biphenyl linkage, of the corresponding dimer as
the sole reaction product. The reaction followed Michaelis-Menten kinetics, for
both homovanillic acid and hydrogen peroxide. Other systems, such as cytochrome
c/H(2)O(2) and Fenton reagents, were also able to oxidize homovanillic acid to
its dimer. It can be affirmed that possible interference by other oxidative
systems - that could be present in the biological materials tested - should be
considered in assays of peroxidase activity based on the detection of the dimer
of homovanillic acid.
PMID- 10785363
TI - Natural allelic variation of duck erythrocyte histone H1b.
AB - In our previous work (J. Palyga, Genetic polymorphisms of histone H1. b in duck
erythrocytes. Hereditas 114, 85-89, 1991) we reported a genetic polymorphism of
duck erythrocyte histone H1.b. Here, we screened H1 preparations in a two
dimensional polyacrylamide gel to refine the distribution of allelic forms of
H1.b in fifteen duck populations. We have revealed that the frequency of H1.b
allelic variants was significantly different among many conservative and breeding
duck groups. While b(1) and b(3) were common in all populations screened, the
allele b(2), with a slightly lower apparent molecular weight, was confined mainly
to brown-feathered ducks (Khaki Campbell and Orpington) and descendent lines. The
C- and N-terminal peptides released upon cleavage with N-bromosuccinimide and
Staphylococcus aureus protease V8 from duck allelic histones H1. b2 and H1.b3,
respectively, migrated differently in the gel, probably as a result of potential
amino acid variation in a C-terminal domain.
PMID- 10785364
TI - Degradation of methoxysuccinyl-phe-leu-phe-7-amido-4-trifluoromethyl coumarin
(FLF) in cultured myotubes and HepG2 cells is proteasome- and calpain/calcium
dependent.
AB - During recent years, it has become increasingly clear that the ubiquitin
proteasome proteolytic pathway regulates intracellular protein degradation in
various physiological and pathophysiological conditions. Substrates specifically
degraded by the proteasome are important tools to assess the involvement of the
proteasome in cellular proteolysis. It was recently proposed that the membrane
permeable substrate methoxysuccinyl-phenylalanine-leucine-phenylalanine-7-amido-4
trifluoromethyl coumarin (FLF) is degraded specifically by the proteasome. The
role of other proteolytic pathways in the degradation of FLF, however, is not
fully understood. In the present study, we tested the role of different
proteolytic pathways in the degradation of FLF in cultured myotubes and HepG2
cells by treating the cells with inhibitors of lysosomal, calpain and proteasome
activity. In addition, we tested the hypothesis that insulin blocks proteasome
dependent degradation of FLF in myotubes and HepG2 cells. Results suggest that
degradation of FLF in both myotubes and HepG2 cells is regulated by proteasome
and calpain activity but not by lysosomal activity. Insulin inhibited proteasome
dependent but not calpain-dependent degradation of FLF in both myotubes and HepG2
cells. The results are important because they suggest that FLF degradation does
not specifically reflect proteasome activity.
PMID- 10785365
TI - The N-terminal portion of the main cytosolic loop mediates K+ sensitivity in the
retinal rod Na+/Ca2+-K+-exchanger.
AB - Two types of Na+/Ca2+-exchangers have been characterized in the literature: The
first is the cardiac, skeletal muscle and brain type, which exchanges 1 Ca2+ for
3 Na+, the second, found in retinal photosensor cells, transports 1 Ca2+ and 1 K+
in exchange for 4 Na+. The present work describes the properties of chimeric
constructs of the two exchanger types. Ca2+ gel overlay experiments have
identified a high affinity (Kd in the 1 microM range) Ca2+-binding domain between
Glu601 and Asp733 in the main cytosolic loop of the retinal protein, just after
transmembrane domain 5. Insertion of the retinal Ca2+-binding domain in the
cytosolic loop of the cardiac exchanger conferred K+-dependence to the Ca2+
uptake activity of the chimeric constructs expressed in HeLa cells. The apparent
Km of the K+ effect was about 1 mM. Experiments with C-terminally truncated
versions of the retinal insert indicated that the sequence between Leu643 and
Asp733 was critical in mediating K+ sensitivity of the recombinant chimeras.
Thus, the high affinity Ca2+-binding domain in the main cytosolic loop of the
retinal exchanger may regulate the activity of the retinal protein by binding
Ca2+, and by conferring to it K+ sensitivity.
PMID- 10785367
TI - Human oxytocin receptors in cholesterol-rich vs. cholesterol-poor microdomains of
the plasma membrane.
AB - We analyzed the properties of a G protein-coupled receptor localized in
cholesterol-poor vs. cholesterol-rich microdomains of the plasma membrane. For
this purpose, the human oxytocin receptor, which is very sensitive against
alterations of the membrane cholesterol level, was stably expressed in HEK293
cells. To calculate the total number of receptors independent of ligand binding
studies, the oxytocin receptor was tagged with an enhanced green fluorescent
protein (EGFP) which did not change the functional properties of the receptor.
Only 1% of the oxytocin receptors were present in cholesterol-rich detergent
insoluble domains. In contrast, employing a detergent-free fractionation scheme
that preserves the functional activity of the receptor, we detected 10-15% of the
receptors in cholesterol-rich low-density membranes and therein the high-affinity
state receptors were twofold enriched. In cholesterol-poor vs. cholesterol-rich
domains, high-affinity oxytocin receptors behaved similar with respect to their
agonist binding kinetics and GTP sensitivity. However, high-affinity oxytocin
receptors localized in cholesterol-rich low-density membranes showed a markedly
enhanced (t (1/2) approximately threefold) stability at 37 degrees C as compared
with the oxytocin receptors localized in the cholesterol-poor high-density
membranes. Addition of cholesterol to the high-density membranes fully protected
the oxytocin receptors against loss of function. The importance of cholesterol to
stabilize the oxytocin receptor was supported in experiments with solubilized
receptors. Cholesterol markedly delayed the inactivation of oxytocin receptors
solubilized with Chapso. In conclusion, the data of this report suggest that
functional properties of heptahelical receptor proteins could differ in
dependence of their localization in different membrane microdomains.
PMID- 10785366
TI - Characterization of three cloned and expressed 13-hydroperoxide lyase isoenzymes
from alfalfa with unusual N-terminal sequences and different enzyme kinetics.
AB - Three full-length cDNAs from alfalfa seedlings coding for hydroperoxide lyases
were cloned and expressed in Escherichia coli and characterized as cytochrome
P450 enzymes. The isoenzymes were specific for 13-hydroperoxy linoleic and
linolenic acids and did not use the 9-hydroperoxy isomers as substrates. Because
alfalfa contains both specificities, this indicates the presence of two different
types of hydroperoxide lyases, each specific for one kind of substrate. The
enzymes contain 480 amino acids (54 kDa) and contain an unusual, nonplastidic N
terminal sequence of 22 amino acids, which strongly reduces the enzyme activity.
The only known presequence of a hydroperoxide lyase (from Arabidopsis thaliana)
was considered to be a transit sequence. The reduced enzyme activity, however,
indicates that the hydroperoxide lyases with N-terminal extensions could be pro
enzymes. This hypothesis is supported by the fast release of hydroperoxide lyase
products by plants upon wounding. One of the isoenzymes showed a strongly
decreased Vmax and Km compared to the other two. Because this is probably due to
the substitution of Ser377 by Phe; the residue at position 377 seems to be
important. This is the first time that sufficient quantities of hydroperoxide
lyase have been obtained for characterization studies, by circumventing difficult
purification procedures and degradation of the enzyme. The high expression level,
easy purification, good stability and high specificity make these cloned
hydroperoxide lyases excellent tools to study the reaction mechanism and
structure. We postulate an integrated reaction mechanism, based on the known
chemistry of cytochrome P450 enzymes. This is the first mechanism that unifies
all observed features of hydroperoxide lyases.
PMID- 10785368
TI - Methyl-coenzyme M formation in methanogenic archaea. Involvement of zinc in
coenzyme M activation.
AB - Methyl-coenzyme M (2-methylthioethane sulfonate) is the key intermediate of
methane formation in methanogenic archaea. It is generated from coenzyme M (2
mercaptoethane sulfonate) in methyl transfer reactions catalyzed by proteins
containing zinc. Here, we report that, for methyltransferase MtaA from
Methanosarcina barkeri, the zinc is involved in coenzyme M activation. For the
experiments an inactive MtaA apoprotein was obtained by heterologous
overproduction in Escherichia coli grown in the presence of 2 mM EDTA. The
apoprotein was found to react with zinc or cobalt to the fully active holoenzyme.
Appoximately 1 mol of transition metal was bound per mol of protein. Upon
incubation of the holoenzyme with coenzyme M approximately 1 mol of proton was
released per mol of zinc or cobalt. Protons were not released upon incubation of
the apoprotein with coenzyme M or of the holoprotein with other thiol compounds
or with methyl-coenzyme M. The findings are interpreted as indicating that the
role of the transition metal in MtaA is to lower the microscopic pKa of the thiol
group of coenzyme M by coordination to the zinc, and thus to increase its
nucleophilicity for methyl group attack. The pKZn2+ of MtaA was re-determined and
found to be > 15 and not 9.6 as previously reported by us.
PMID- 10785369
TI - Monoclonal antibodies to vascular endothelial growth factor-D block its
interactions with both VEGF receptor-2 and VEGF receptor-3.
AB - Vascular endothelial growth factor-D (VEGF-D), the most recently discovered
mammalian member of the VEGF family, is an angiogenic protein that activates VEGF
receptor-2 (VEGFR-2/Flk1/KDR) and VEGFR-3 (Flt4). These receptor tyrosine
kinases, localized on vascular and lymphatic endothelial cells, signal for
angiogenesis and lymphangiogenesis. VEGF-D consists of a central receptor-binding
VEGF homology domain (VHD) and N-terminal and C-terminal propeptides that are
cleaved from the VHD to generate a mature, bioactive form consisting of dimers of
the VHD. Here we report characterization of mAbs raised to the VHD of human VEGF
D in order to generate VEGF-D antagonists. The mAbs bind the fully processed VHD
with high affinity and also bind unprocessed VEGF-D. We demonstrate, using
bioassays for the binding and cross-linking of VEGFR-2 and VEGFR-3 and biosensor
analysis with immobilized receptors, that one of the mAbs, designated VD1, is
able to compete potently with mature VEGF-D for binding to both VEGFR-2 and VEGFR
3 for binding to mature VEGF-D. This indicates that the binding epitopes on VEGF
D for these two receptors may be in close proximity. Furthermore, VD1 blocks the
mitogenic response of human microvascular endothelial cells to VEGF-D. The anti
(VEGF-D) mAbs raised to the bioactive region of this growth factor will be
powerful tools for analysis of the biological functions of VEGF-D.
PMID- 10785370
TI - The ionization of a buried glutamic acid is thermodynamically linked to the
stability of Leishmania mexicana triose phosphate isomerase.
AB - The amino acid sequence of Leishmania mexicana triose phosphate isomerase is
unique in having at position 65 a glutamic acid instead of a glutamine. The
stability properties of LmTIM and the E65Q mutant were investigated by pH and
guanidinium chloride-induced unfolding. The crystal structure of E65Q was
determined. Three important observations were made: (a) there are no structural
rearrangements as the result of the substitution; (b) the mutant is more stable
than the wild-type; and (c) the stability of the wild-type enzyme shows strong pH
dependence, which can be attributed to the ionization of Glu65. Burying of the
Glu65 side chain in the uncharged environment of the dimer interface results in a
shift in pKa of more than 3 units. The pH-dependent decrease in overall stability
is due to weakening of the monomer-monomer interactions (in the dimer). The E65Q
substitution causes an increase in stability as the result of the formation of an
additional hydrogen bond in each subunit (DeltaDeltaG degrees of 2 kcal.mol-1 per
monomer) and the elimination of a charged group in the dimer interface
(DeltaDeltaG degrees of at least 9 kcal.mol-1 per dimer). The computated shift in
pKa and the stability of the dimer calculated from the charge distribution in the
protein structure agree closely with the experimental results. The guanidinium
chloride dependence of the unfolding constant was smaller than expected from
studies involving monomeric model proteins. No intermediates could be identified
in the unfolding equilibrium by combining fluorescence and CD measurements. Study
of a stable monomeric triose phosphate isomerase variant confirmed that the
phenomenon persists in the monomer.
PMID- 10785372
TI - Characterization of the myo-inositol transport system in Trypanosoma cruzi.
AB - myo-inositol is a growth factor for mammalian cells as well as for the pathogenic
protozoa Trypanosoma cruzi. Most of the cell surface molecules in this organism
rely on myo-inositol as the biosynthetic precursor for phosphoinositides and
glycosylated phosphatidylinositols. The aim of this work was to investigate the
process of myo-inositol translocation across the parasite cell membrane. myo
Inositol uptake was concentration-dependent in the concentration range 0.1-10
microM with maximal transport obtained at 8 microM. Using sodium-free buffers,
where Na+ was replaced by choline or K+, myo-inositol uptake was inhibited by
50%. Furosemide, an inhibitor of the ouabain-insensitive Na+-ATPase, inhibited
the Na+-dependent and Na+-independent myo-inositol uptake by 68 and 33%,
respectively. In contrast, ouabain, an (Na++/K+) ATPase inhibitor, did not affect
transport. Part of the myo-inositol uptake is mediated by active transport as it
was inhibited when energy metabolism inhibitors such as carbonyl cyanide p
(trifluoromethoxy)-phenylhydrazone (34%), 2,4-dinitrophenol (50%), KCN (71%) and
NaN3 (69%) were added to the medium, or the temperature of the medium was lowered
to 4 degrees C. The addition of glucose (5-50 mM) or mannose (10 mM) did not
change the myo-inositol uptake, whereas the addition of 10 mM nonlabeled myo
inositol totally inhibited this transport, indicating that the transporter is
specific for myo-inositol. Phloretin (0.3 mM) and phoridzin (5 mM), but not
cytochalasin B, were efficient inhibitors of myo-inositol uptake. A portion of
the accumulated myo-inositol is converted to inositol phosphates and
phosphoinositides. These data show that myo-inositol transport in T. cruzi
epimastigotes is mediated by at least two specific transporters - one Na+
dependent and the other Na+-independent.
PMID- 10785371
TI - M1 muscarinic acetylcholine receptors activate zif268 gene expression via small G
protein Rho-dependent and lambda-independent pathways in PC12D cells.
AB - We have previously shown that stimulation of M1 muscarinic acetylcholine
receptors (mAChRs) in neuronal PC12D cells rapidly induces the immediate-early
gene zif 268 [Ebihara, T. & Saffen, D. (1997) J. Neurochem. 68, 1001-1010]. Here
we show that stimulation of M1 mAChRs in these cells activates four distal serum
response elements (SREs) in the zif 268 promoter, and that this activation is
strongly inhibited by Clostridium botulinum C3 exoenzyme (C3), which specifically
inactivates the small G-protein Rho. Even with high doses of C3, however, a
portion of the activation remains intact, indicating that stimulation of M1
mAChRs activates zif 268 SREs via Rho-dependent and Rho-independent pathways.
Moreover, the Rho-independent activation of zif 268 SREs is inhibited by the
dominant-negative form of the small G-protein Ras, suggesting that Rho
independent activation of zif 268 SREs is mediated by Ras. To determine if
muscarinic agonists activate RhoA, we also measured the translocation of RhoA
from the cytosolic fraction to the particulate fraction. Translocation of RhoA to
the particulate fraction was observed within 15 min following stimulation of M1
mAChRs, indicating that RhoA is activated with sufficient rapidity to participate
in the induction of zif 268 mRNA. Together, these results suggest that RhoA is
activated following stimulation of M1 mAChRs and functions in SRE-dependent
induction of the zif 268 gene within a Ras-independent pathway.
PMID- 10785373
TI - Design syntheses and mitochondrial complex I inhibitory activity of novel
acetogenin mimics.
AB - Some natural acetogenins are the most potent inhibitors of mitochondrial complex
I. These compounds are characterized by two functional units [i.e. hydroxylated
tetrahydrofuran (THF) and alpha, beta-unsaturated gamma-lactone ring moieties]
separated by a long alkyl spacer. To elucidate which structural factors of
acetogenins, including their active conformation, are crucial for the potent
inhibitory activity we synthesized a novel bis-acetogenin and its analogues
possessing two gamma-lactone rings connected to bis-THF rings by flexible alkyl
spacers. The inhibitory potency of the bis-acetogenin with bovine heart
mitochondrial complex I was identical to that of bullatacin, one of the most
potent natural acetogenins. This result indicated that one molecule of the bis
acetogenin does not work as two reactive inhibitors, suggesting that a gamma
lactone and the THF ring moieties act in a cooperative manner on the enzyme. In
support of this, either of the two ring moieties synthesized individually showed
no or very weak inhibitory effects. Moreover, combined use of the two ring
moieties at various molar ratios exhibited no synergistic enhancement of the
inhibitory potency. These observations indicate that both functional units work
efficiently only when they are directly linked by a flexible alkyl spacer.
Therefore, some specific conformation of the spacer must be important for optimal
positioning of the two units in the enzyme. Furthermore, the alpha,beta
unsaturated gamma-lactone, the 4-OH group in the spacer region, the long alkyl
tail attached to the THF unit and the stereochemistry surrounding the
hydroxylated bis-THF rings were not crucial for the activity, although these are
the most common structural features of natural acetogenins. The present study
provided useful guiding principles not only for simplification of complicated
acetogenin structure, but also for further wide structural modifications of these
molecules.
PMID- 10785374
TI - Induction of intracellular signalling by cyclic glycerophosphates and their deoxy
analogues.
AB - Cyclic glycerophosphates can be formed by enzymic degradation of phospholipids.
They have only recently attracted attention, and their physiological function is
still obscure. In this study, we have searched for signalling functions of the
natural 1,3-cyclic and 1,2-cyclic glycerophosphates, their deoxy analogues, and
the phenyl esters of the 1,3-cyclic phosphates. Linear sn-glycerol 3-phosphate
and glycerol 2-phosphate served as the control compounds. Each of the six
membered ring cyclic phosphates tested induced rapid intracellular tyrosine
phosphorylation in CHO and NIH-3T3 cells when applied extracellularly at a
concentration of 0.5-4 microM. The phosphorylated intracellular proteins had
molecular masses of approximately 35 kDa, approximately 45 kDa, 60-70 kDa and
approximately 120 kDa. The five-membered ring cyclic phosphates had a similar
effect, but at an external concentration of 2-10 microM, while sn-glycerol 3
phosphate and glycerol 2-phosphate had no effect. The six-membered cyclic
phosphates also induced rapid threonine phosphorylation in CHO cells of
approximately 18-kDa, approximately 35-kDa, and approximately 38-kDa proteins.
Further experiments indicated that the cyclic phosphates partition rapidly into
the cell cytosol where they activate kinases, including mitogen-activated protein
kinase. When their intracellular level increases, dephosphorylation presumably
takes place. This pattern may account for the signalling profile of cyclic
phosphates and suggests that they may take part in processes associated with cell
differentiation.
PMID- 10785375
TI - Utilization of leucine and acetate as carbon sources for sterol and fatty acid
biosynthesis by Old and New World Leishmania species, Endotrypanum monterogeii
and Trypanosoma cruzi.
AB - The relative roles of acetate and leucine in the provision of a carbon source for
fatty acid and sterol biosynthesis in several trypanosomatid species were
investigated using 14C- and 13C-labelled acetate, glucose and leucine as
substrates. Promastigotes of Leishmania species synthesized a large proportion of
their sterol from leucine. L. major (LV39), L. amazonensis and L. mexicana were
the most efficient utilizers of leucine, producing at least 70-77% of their
sterol from leucine; L. braziliensis, L. donovani and L. tropica apparently
produced less sterol from leucine (23-36%) and L. major (LV561), L. adleri and L.
panamamensis were intermediate, utilizing leucine to provide 51-58% of their
sterol. In all the cases the balance of the sterol produced was apparently
synthesized from carbon arising from acetate. The related trypanosomatid
Endotrypanum monterogeii also produced a large amount (77%) of its sterol from
leucine rather than acetate. By contrast Trypanosoma cruzi elaborated only 8% of
its sterol from leucine and used acetate far more effectively than the Leishmania
species for sterol biosynthesis. The fatty acid moieties of the triacylglycerols
and phospholipids were produced from acetate. Leucine was also incorporated into
the fatty acids to varying extents in the different organisms showing that
leucine can also be metabolized in trypanosomatids to generate acetyl-CoA.
PMID- 10785376
TI - Structural identification of the lipopolysaccharide O-antigen produced by
Yersinia enterocolitica serotype O:28.
AB - The structure of the O-antigenic polysaccharide (O-PS) component of the
lipopolysaccharide produced by Yersinia enterocolitica serotype O:28 has been
elucidated. From chemical methods involving glycose analysis, periodate
oxidation, methylation and the use of one- and two-dimensional NMR spectroscopy,
the O-PS was found to be a polymer of repeating branched hexasaccharide units
composed of L-rhamnose (four parts), 2-acetamido-2-deoxy-D-glucose (one part),
and 2-acetamido-2-deoxy-D-galacturonic acid (one part) having the following
structure:
PMID- 10785377
TI - Purification and characterization of active recombinant human napsin A.
AB - Recombinant human napsin A expressed in human embryonic kidney 293 cells was
purified to homogeneity by a single-step procedure using part of napsin A
propeptide as affinity ligand. N-Terminal amino-acid sequencing of the purified
enzyme identified the mature form of napsin A. Treatment of purified napsin A
with endoglycosidases F and H resulted in a decrease in its molecular mass from
39 kDa to approximately 37 kDa, confirming that napsin A is glycosylated. The
kinetic properties were analyzed by using two fluorogenic synthetic substrates
K(Dabsyl)-TSLLMAAPQ-Lucifer yellow (DS1) and K(Dabsyl)-TSVLMAAPQ-Lucifer yellow
(DS3). The Km values obtained were 1.7 microM and 6.2 microM, respectively. A
substrate-specificity study using a napsin A-targeted peptide library confirmed
the preference of napsin A for hydrophobic residues at positions P1 and P1'.
Adjacent positions, P2-P4 and P2'-P4', appeared less restricted in distribution
of amino acids. A pH optimum between 4.0 and 5.5 at room temperature was
determined. The purified enzyme was fully active for more than 10 h at pH 5.0 and
6.0, while a half-life of 4 h was determined at pH 7.0 and 37 degrees C.
PMID- 10785378
TI - Investigation of the haem-nicotinate interaction in leghaemoglobin. Role of
hydrogen bonding.
AB - A strategic assessment of the contributions of two active-site hydrogen bonds in
the binding of nicotinate to recombinant ferric soybean leghaemoglobin a (rLb)
was carried out by mutagenic replacement of the hydrogen-bonding residues (H61A
and Y30A variants) and by complementary chemical substitution of the carboxylate
functionality on the nicotinate ligand. Dissociation constants, Kd (pH 5.5, mu =
0.10 M, 25.0 +/- 0.1 degrees C), for binding of nicotinate to ferric rLb, H61A
and Y30A were 1.4 +/- 0.3 microM, 19 +/- 1 microM and 11 +/- 1 microM,
respectively; dissociation constants for binding of nicotinamide were,
respectively, 38 +/- 1 mM, 50 +/- 2 mM and 12 +/- 1 mM, and for binding of
pyridine were 260 +/- 50 microM, 4.5 +/- 0.5 microM and 66 +/- 8 microM,
respectively. Binding of cyanide and azide to the H61A and Y30A variants was
unaffected by the mutations. The pH-dependence of nicotinate binding for rLb and
Y30A was consistent with a single titration process (pKa values 6.9 +/- 0.1 and
6.7 +/- 0.2, respectively); binding of nicotinate to H61A was independent of pH.
Reduction potentials for the rLb and rLb-nicotinate derivatives were 29 +/- 2 mV
(pH 5.40, 25.0 degrees C, mu = 0.10 M) and - 65 +/- 2 mV (pH 5.42, 25.0 degrees
C, mu = 0.10 M), respectively. The experiments provide a quantitative assessment
of the role of individual hydrogen bonds in the binding process, together with a
definitive determination of the pKa of His61 and unambiguous evidence that
titration of His61 controls binding in the neutral to alkaline region.
PMID- 10785379
TI - Characterization of the early steps of OE17 precursor transport by the thylakoid
DeltapH/Tat machinery.
AB - In order to probe the structure and protein translocation function of the
thylakoid Tat machinery, a 25-residue C-terminal extension containing a 13
residue in vivo biotinylation tag and a 6x His tag was added to a mutant
precursor of the 17-kDa subunit of the oxygen-evolving complex to form pOE17(C)
BioHis. When avidin was attached to biotinylated precursor in situ, the precursor
avidin complex was neither imported nor did it form a membrane-spanning
translocation intermediate. It did, however, competitively inhibit the
translocation of unbiotinylated precursor with an apparent KI unaffected by
avidin. It is shown that the precursor protein achieves a stable folded structure
upon dilution from urea, suggesting that the avidin-induced inhibition of
transport results from a folding-induced proximity of N-terminal and C-terminal
domains. It is further demonstrated that the majority of precursor rapidly binds
to the thylakoid membrane, remaining import competent and yet undissociable by
high salt or high pH treatment at ice temperature. The membrane binding event is
unaffected by avidin. Import kinetics reveal that nonproton motive force-driven
transport steps make up a major fraction of the transport time. These
observations suggest that the N-terminal presequence on the avidin-bound
precursor is available for membrane binding and initial recognition by the
transport machinery, but the attached avidin signals the machinery that the
precursor is an incorrectly configured substrate and thus import is aborted.
Consequently, the DeltapH/Tat machinery's proofreading mechanism must operate
after precursor recognition but before the committed step in transport.
PMID- 10785380
TI - Bacterial-injection-induced syntheses of N-beta-alanyldopamine and Dopa
decarboxylase in the hemolymph of coleopteran insect, Tenebrio molitor larvae.
AB - Injection of Escherichia coli into larvae of the coleopteran Tenebrio molitor
resulted in the appearance of a dopamine-like substance on the electrochemical
detector. To characterize this dopamine-like substance, we purified it to
homogeneity from the immunized hemolymph and determined its molecular structure
to be N-beta-alanyldopamine using the liquid chromatographic/tandem mass
spectrometric method. Chemically synthesized N-beta-alanyldopamine showed the
same retention time on HPLC as the purified N-beta-alanyldopamine from immunized
larvae. To elucidate the molecular mechanism of N-beta-alanyldopamine synthesis
in vivo, we examined the enzyme activity of Dopa decarboxylase against E. coli
injected hemolymph of T. molitor larvae. The enzyme activity of Dopa
decarboxylase increased dramatically approximately 8 h after injection; Dopa
decarboxylase activity of injected larvae being 10-times higher than naive larvae
after 24 h. To evaluate the extent of quantitative changes of Dopa decarboxylase
in response to bacterial challenge, Tenebrio Dopa decarboxylase was purified to
homogeneity from the whole larvae and a cDNA clone for Tenebrio Dopa
decarboxylase was isolated. RNA blot hybridization revealed that expression of
the Dopa decarboxylase gene was activated transiently 3-8 h after E. coli
challenge. Immunoprecipitation experiments showed that Tenebrio Dopa
decarboxylase was detected from 8 to 24 h in E. coli-injected larval extract.
Thus, bacterial injection into T. molitor larvae might induce transcriptional
activation of a Dopa decarboxylase gene, and then synthesis of N-beta
alanyldopamine. The synthesized N-beta-alanyldopamine might be used as a
substrate by phenoloxidase during melanin synthesis in the humoral defense
response or the melanotic encapsulation reaction of the cellular defense
response.
PMID- 10785381
TI - Biophysical studies of the development of amyloid fibrils from a peptide fragment
of cold shock protein B.
AB - The peptide CspB-1, which represents residues 1-22 of the cold shock protein CspB
from Bacillus subtilis, has been shown to form amyloid fibrils when solutions
containing this peptide in aqueous (50%) acetonitrile are diluted in water [M.
Gross et al. (1999) Protein Science 8, 1350-1357] We established conditions in
which reproducible kinetic steps associated with the formation of these fibrils
can be observed. Studies combining these conditions with a range of biophysical
methods reveal that a variety of distinct events occurs during the process that
results in amyloid fibrils. A CD spectrum indicative of beta structure is
observed within 1 min of the solvent shift, and its intensity increases on a
longer timescale in at least two kinetic phases. The characteristic wavelength
shift of the amyloid-binding dye Congo Red is established within 30 min of the
initiation of the aggregation process and corresponds to one of the phases
observed by CD and to changes in the Fourier transform-infrared spectrum
indicative of beta structure. Short fibrillar structures begin to be visible
under the electron microscope after these events, and longer, well-defined
amyloid fibrils are established on a timescale of hours. NMR spectroscopy shows
that there are no significant changes in the concentration of monomeric species
in solution during the events leading to fibril formation, but that soluble
aggregates too large to be visible in NMR spectra are present throughout the
process. A model for amyloid formation by this peptide is presented which is
consistent with these kinetic data and with published work on a variety of
disease-related systems. These findings support the concept that the ability to
form amyloid fibrils is a generic property of polypeptide chains, and that the
mechanism of their formation is similar for different peptides and proteins.
PMID- 10785382
TI - Analysis of the thyrotropin-releasing hormone-degrading ectoenzyme by site
directed mutagenesis of cysteine residues. Cys68 is involved in disulfide-linked
dimerization.
AB - Thyrotropin-releasing hormone-degrading ectoenzyme is a member of the M1 family
of Zn-dependent aminopeptidases and catalyzes the degradation of thyrotropin
releasing hormone (TRH; Glp-His-Pro-NH2). Cloning of the cDNA of this enzyme and
biochemical studies revealed that the large extracellular domain of the enzyme
with the catalytically active site contains nine cysteine residues that are
highly conserved among species. To investigate the functional role of these
cysteines in TRH-DE we used a site-directed mutagenesis approach and replaced
individually each cysteine by a serine residue. The results revealed that the
proteolytically truncated and enzymatically fully active enzyme consists of two
identical subunits that are associated noncovalently by protein-protein
interactions but not via interchain S-S bridges. The eight cysteines contained
within this region are all important for the structure of the individual subunit
and the enzymatic activity, which is dramatically reduced in all mutant enzymes.
This is even true for the four cysteines that are clustered within the C-terminal
domain remote from the Zn-binding consensus sequence HEICH. In contrast, Cys68,
which resides within the stalk region seven residues from the end of the
hydrophobic membrane-spanning domain, can be replaced by serine without a
significant change in the enzymatic activity. Interestingly, this residue is
involved in the formation of an interchain disulfide bridge. Covalent
dimerization of the subunits, however, does not seem to be essential for
efficient biosynthesis, enzymatic activity and trafficking to the cell surface.
PMID- 10785383
TI - Shedding of interleukin-6 receptor and tumor necrosis factor alpha. Contribution
of the stalk sequence to the cleavage pattern of transmembrane proteins.
AB - A functionally and structurally diverse group of transmembrane proteins including
transmembrane forms of mediators or receptors can be proteolytically cleaved to
form soluble growth factors or receptors. Recently, the proteolytic activity
responsible for pro-tumor necrosis factor alpha (proTNFalpha) processing has been
identified and named TACE (TNFalpha converting enzyme). In experiments with TACE
deficient (TACE-/-) fibroblasts we found that 4beta-phorbol 12-myristate 13
acetate (PMA)-induced shedding of the interleukin-6 receptor (IL-6R) is strongly
reduced. A basal hydroxamate sensitive release of IL-6R, however, could still be
detected. This result demonstrates that TACE plays a role in IL-6R processing and
that additional metalloproteases might be involved. PMA-induced shedding of IL-6R
in TACE deficient mouse fibroblasts could be restored by stable transfection of a
TACE cDNA. To characterize differences between shedding of IL-6R and proTNFalpha
we generated chimeric IL-6R and proTNFalpha proteins wherein the endogenous
cleavage sites (CS) had been replaced by the corresponding region of proTNFalpha
and IL-6R, respectively. Interestingly, proTNFalpha chimeric proteins showed only
minimal shedding. In contrast, IL-6R chimeras containing the proTNFalpha CS were
shed spontaneously, processing was not further induced by PMA. Thus, the cleavage
pattern transferred by the introduction of the proTNFalpha CS is similar to that
of proTNFalpha itself. We conclude that the amino-acid sequence at the
proteolytic CS contributes to the cleavage characteristics of a protein. However,
this information alone is not sufficient to transfer cleavability as seen with
proTNFalpha chimeras containing the IL-6R CS and which were resistant to
shedding.
PMID- 10785384
TI - Propeptide dependent activation of the Antarctic krill euphauserase precursor
produced in yeast.
AB - Euphauserase is a brachyurin type digestive enzyme isolated from Antarctic krill.
The brachyurins belong to clan SA of the S1 family of serine endopeptidases. In
this study, we demonstrate that the precursor form of recombinant euphauserase,
termed pro-r-euphauserase, can be successfully expressed in Pichia pastoris. The
presence of most of the 51-residue euphauserase propeptide is essential during
expression, under the growth conditions of Pichia. The propeptide may be required
either for correct folding or processing of the enzyme. Cod trypsin generates a
fully active r-euphauserase from its precursor, which appears to be identical to
the native enzyme. The mature r-euphauserase sequence contains 250 amino-acid
residues including a 13-residue activation peptide, which seems to be attached to
the molecule by a disulfide bond. Euphauserase shares an average sequence
identity of 62% with its type I brachyurin analogue, crab collagenase I. However,
the identity between these two sequences is much higher in the regions shown to
be important for the broad substrate specificity and collagen binding of crab
collagenase I. The type I brachyurins share only 30-40% identities with the type
II brachyurins and trypsins. The low isoelectric point of euphauserase, with a
calculated pI value of 3.9, is typical for the type I brachyurins.
PMID- 10785385
TI - UV-B radiation induced exchange of the D1 reaction centre subunits produced from
the psbA2 and psbA3 genes in the Cyanobacterium synechocystis sp. PCC 6803.
AB - UV-B irradiation of Synechocystis 6803 cells inhibits photosystem II activity,
which can be restored via de novo synthesis of the D1 (and D2) reaction center
subunits. Recently we have shown that of the two psbA genes that encode identical
D1 proteins in Synechocystis 6803, UV-B preferentially enhances the transcription
of psbA3 compared to that of psbA2 [Mate, Z., Sass, L., Szekeres, M., Vass, I.
and Nagy, F. (1998) J. Biol. Chem. 273, 17439-17444]. Here we studied the effect
of UV-B on the synthesis of the D1 protein from the psbA2 and psbA3 genes in the
P7 mutant of Synechocystis 6803. In this mutant, psbA2 carries the Ala251-->Val
point mutation, which confers resistance to the photosystem II electron transport
inhibitor metribuzin, but psbA3 is the same as in the wild-type. By applying
variable chlorophyll fluorescence measurements to distinguish between metribuzin
sensitive and metribuzin-resistant photosystem II centers we quantified the
amount of the D1 protein produced from each of the psbA3 and psbA2 genes. When
the cells were exposed to UV-B light, the fraction of D1 protein produced from
the psbA3 gene was increased from 15-20 to 32-40% of the total D1. This effect
was reversible by transferring the cells to visible light. The rate of D1
production from psbA3 increased with increasing UV-B intensities, and was a
transient phenomenon at low UV-B levels (0.1 microE x m-2 x s-1). It is concluded
that the enhancement of psbA3 gene transcription by UV-B light leads to enhanced
D1 protein synthesis from this gene. Our findings demonstrate that the main role
of psbA3 transcription activated by UV-B is to increase the size of the psbA mRNA
pool available for translation when a rapid repair of the D1 protein is needed
under UV-B stress.
PMID- 10785386
TI - Purification, molecular cloning and ethylene-inducible expression of a soluble
type epoxide hydrolase from soybean (Glycine max [L.] Merr.).
AB - A soybean protein was purified from mature dry seeds. Amino-acid sequencing of
the nine internal peptides derived from this N-terminally blocked protein showed
that it has a significant similarity to the soluble epoxide hydrolases known to
date. A degenerate series of 23-mer oligonucleotides with sequences corresponding
to an internal region of eight amino-acid residues was synthesized as a probe
mixture for detection of a putative epoxide hydrolase cDNA in a developing
cotyledon cDNA library. The 1332-bp cDNA obtained was found to have an open
reading frame encoding the seed epoxide hydrolase-like precursor consisting of
341 amino-acid residues, suggesting that 25 amino-acid residues upstream from the
second methionine correspond to a transit peptide. Employing an Escherichia coli
expression system, the putative mature epoxide hydrolase-like protein was
overexpressed and purified to homogeneity. This recombinant protein was confirmed
to exhibit its epoxide-diol converting activity using styrene oxide as substrate.
The Vmax and Km values for styrene oxide are 1.36 micromol x min-1 x mg-1 and
1500 microM, respectively. Sedimentation equilibrium experiments showed that the
active form of this epoxide hydrolase is monomeric in solution. Using the above
cDNA as a probe, a 12-kb genomic clone was selected and the sequence of a 1933-bp
fragment from this clone was found to cover the entire coding region together
with 5'- and 3'-flanking regions of the soybean epoxide hydrolase gene. The
coding region of the gene, interrupted by two short introns, was identical to the
corresponding regions of the cDNA. Northern blot analyses showed that this
epoxide hydrolase gene was expressed strongly at a very early stage (13 days
after flowering) and then the level of expression gradually decreased and almost
ceased at a very late stage (58 days after flowering) of seed development,
whereas its expression was markedly up-regulated by ethylene treatment. In stems
(hypocotyl portion), the epoxide hydrolase transcript was detected at significant
levels and was also up-regulated in response to ethylene. On the other hand, it
is hardly expressed in leaves, even though they were treated with the
phytohormone. Overall, the results obtained may indicate that soluble-type
epoxide hydrolase mRNA is expressed at the maximum level in an early stage of
seed development. Later, oil bodies are formed and subsequently epoxy fatty
acids, naturally occurring metabolites, accumulate within those bodies. The
temporal induction of this epoxide hydrolase transcript in some tissues in
response to ethylene also indicates that this epoxide hydrolase may play a
crucial role in self-defense systems of plant.
PMID- 10785387
TI - Fidelity analysis of HIV-1 reverse transcriptase mutants with an altered amino
acid sequence at residues Leu74, Glu89, Tyr115, Tyr183 and Met184.
AB - Substitution of particular residues postulated to have a role in active site
architecture can alter the overall fidelity of DNA polymerization by HIV-1. The
effects of this kind of substitution were determined in a lacZ-based assay using
HIV-1 reverse transcriptase with specifically mutated residues. We found that the
reported higher fidelity of nucleotide incorporation by the Met184-->Val and
Glu89-->Gly mutant reverse transcriptases (RTs) was not reflected in a
substantial increase in the overall fidelity for these RT mutants. For the 3TC
resistant Met184-->Val RT mutant an almost wild-type level of overall mutation
frequency was observed, while the foscarnet-resistant RTs harbouring the Glu89-
>Gly mutation showed only a twofold decrease in mutation frequency. The Tyr183-
>Phe mutant RT displayed a slightly lower fidelity than wild-type RT. Conversely,
the ddI-resistant RT mutant containing the Leu74-->Val mutation showed a 3.5-fold
higher fidelity compared to the wild-type enzyme. Finally, the Tyr115-->Ala
substitution rendered the enzyme substantially more error-prone for DNA
polymerization. These results correlate with three-dimensional structural studies
of the polymerase active site and confirm the postulated impact of the Leu74,
Tyr183 and Tyr115 RT residues on the overall fidelity of DNA polymerization by
HIV-1 RT.
PMID- 10785388
TI - A novel function of yeast fatty acid synthase. Subunit alpha is capable of self
pantetheinylation.
AB - The prosthetic group of yeast fatty acid synthase (FAS), 4'-phosphopantetheine,
is covalently linked to Ser180 of subunit alpha. It originates from coenzyme A
and is transferred to the enzyme by a specific phosphopantetheine:protein
transferase (PPTase). The present study demonstrates that the FAS-activating
PPTase of yeast represents a distinct catalytic domain of the FAS complex and
resides within the C-terminal portion of subunit alpha. The autoactivation
capacity of yeast FAS became evident from in vitro pantetheinylation studies
using purified apo-FAS preparations. These were readily converted to
pantetheinylated holo-FAS simply upon addition of free coenzyme A.
Pantetheinylation-competent apo-FAS was prepared in vitro by constructing hybrid
oligomers containing alpha-subunits from two different pantetheine-less FAS
mutants. The respective mutants were selected according to their ability to
complement each other, in vivo. In vitro formation of hybrid apo-FAS complexes
was achieved by dimethylmaleic anhydride (DMMA) -induced reversible dissociation
of mixtures of the two constituent mutant enzymes. This treatment was both
necessary and sufficient to produce pantetheinylation-competent apo-FAS. Specific
FAS activities were comparable independent of whether the apo-enzymes were
pantetheinylated in vivo or in vitro. Apart from the induction of overall FAS
activity, incorporation of phosphopantetheine into apo-FAS was also demonstrated
by the use of 3H-labelled coenzyme A, leading to the formation of radioactively
labelled FAS. It is concluded that pantetheinylation of yeast FAS is performed by
an intrinsic catalytic activity of the apo-enzyme proper. The endogenous PPTase
acts in trans between different subunits alpha in the alpha6beta6 oligomer. The
self-pantetheinylation of yeast FAS represents the first example of an apo-enzyme
being capable of post-translational autoactivitation.
PMID- 10785389
TI - Cancer-associated alternative usage of multiple promoters of human GalCer
sulfotransferase gene.
AB - The galactosylceramide sulfotransferase (cerebroside sulfotransferase, CST) (EC
2.8.2.11) gene is highly expressed in human renal cancer cells. To elucidate the
regulatory mechanism of its gene expression, we have determined the genomic
organization of the human CST gene. The gene comprises at least four exons and
spans about 20 kb. The coding region is located in exons 3 and 4. To determine
the transcription initiation sites, 5'-rapid amplification of cDNA ends analysis
was performed using mRNA obtained from four human renal cancer cell lines, SMKT
R1-R4, and normal human renal proximal tubular cells. We found four transcription
initiation sites and alternative usage of six exons corresponding to the 5'
untranslated region in cancer cells. On the other hand, the only transcript
beginning at exon 1a was observed in normal cells. Using reverse transcriptase
PCR analysis, we confirmed that all of the exons 1a-d, especially exons 1c and
1d, are used as a transcription initiation site in cancer cells, whereas only
exons 1a and 1b, mostly 1a, are utilized in normal cells. Analyzing the protein
production from the mRNA variants with different 5'-UTRs, we found that all the
transcripts examined produced the identical proteins. These observations suggest
that the aberrant usage of transcription initiation sites flanked with
promoters/enhancers is involved in the cancer-associated expression of the CST
gene. Furthermore, this gene was assigned to human chromosome 22q12 by means of
fluorescence in situ hybridization.
PMID- 10785390
TI - Uncoupling proteins 2 and 3 interact with members of the 14.3.3 family.
AB - Uncoupling proteins (UCPs) are members of the superfamily of the mitochondrial
anion carrier proteins (MATP). Localized in the inner membrane of the organelle,
they are postulated to be regulators of mitochondrial uncoupling. UCP2 and 3 may
play an important role in the regulation of thermogenesis and, thus, on the
resting metabolic rate in humans. To identify interacting proteins that may be
involved in the regulation of the activity of UCPs, the yeast two-hybrid system
was applied. Segments of hUCP2 containing the hydrophilic loops facing the
intermembrane space, or combinations of these, were used to screen an adipocyte
activation domain (AD) fusion library. The 14.3.3 protein isoforms theta, beta,
zeta were identified as possible interacting partners of hUCP2. Screening of a
human skeletal muscle AD fusion library, on the other hand, yielded several
clones all of them encoding the gamma isoform of the 14.3.3 family. Mapping
experiments further revealed that all these 14.3.3 proteins interact specifically
with the C-terminal intermembrane space domain of both hUCP2 and hUCP3 whereas no
interactions could be detected with the C-terminal part of hUCP1. Direct
interaction between UCP3 and 14.3.3 theta could be demonstrated after in vitro
translation by coimmunoprecipitation. When coexpressed in a heterologous yeast
system, 14.3.3 proteins potentiated the inhibitory effect of UCP3 overexpression
on cell growth. These findings suggest that 14.3.3 proteins could be involved in
the targeting of UCPs to the mitochondria.
PMID- 10785391
TI - Enzyme-mediated sulfide production for the reconstitution of [2Fe-2S] clusters
into apo-biotin synthase of Escherichia coli. Sulfide transfer from cysteine to
biotin.
AB - We previously showed that biotin synthase in which the (Fe-S) cluster was
labelled with 34S by reconstitution donates 34S to biotin [B. Tse Sum Bui, D.
Florentin, F. Fournier, O. Ploux, A. Mejean & A. Marquet (1998) FEBS Lett. 440,
226-230]. We therefore proposed that the source of sulfur was very likely the (Fe
S) centre. This depletion of sulfur from the cluster during enzymatic reaction
could explain the absence of turnover of the enzyme which means that to restore a
catalytic activity, the clusters have to be regenerated. In this report, we show
that the NifS protein from Azotobacter vinelandii and C-DES from Synechocystis as
well as rhodanese from bovine liver can mobilize the sulfur, respectively, from
cysteine and thiosulfate for the formation of a [2Fe-2S] cluster in the
apoprotein of Escherichia coli biotin synthase. The reconstituted enzymes were as
active as the native enzyme. When [35S]cysteine was used during the
reconstitution experiments in the presence of NifS, labelled (Fe35S) biotin
synthase was obtained. This enzyme produced [35S]biotin, confirming the results
obtained with the 34S-reconstituted enzyme. NifS was also effective in mobilizing
selenium from selenocystine to produce an (Fe-Se) cluster. However, though NifS
could efficiently reconstitute holobiotin synthase from the apoform, starting
from cysteine, these two effectors had no significant effect on the turnover of
the enzyme in the in vitro assay.
PMID- 10785393
TI - Oxidation of aromatic sulfides by lignin peroxidase from Phanerochaete
chrysosporium.
AB - The reaction of H2O2 with 4-substituted aryl alkyl sulfides (4-XC6H4SR),
catalysed by lignin peroxidase (LiP) from Phanerochaete chrysosporium, leads to
the formation of sulfoxides, accompanied by diaryl disulfides. The yields of
sulfoxide are greater than 95% when X = OMe, but decrease significantly as the
electron donating power of the substituent decreases. No reaction is observed for
X = CN. The bulkiness of the R group has very little influence on the efficiency
of the reaction, except for R = tBu. The reaction exhibits enantioselectivity (up
to 62% enantiomeric excess with X = Br, with preferential formation of the
sulfoxide with S configuration). Enantioselectivity decreases with increasing
electron density of the sulfide. Experiments in H218O show partial or no
incorporation of the labelled oxygen into the sulfoxide, with the extent of
incorporation decreasing as the ring substituents become more electron
withdrawing. On the basis of these results, it is suggested that LiP compound I
(formed by reaction between the native enzyme and H2O2), reacts with the sulfide
to form a sulfide radical cation and LiP compound II. The radical cation is then
converted to sulfoxide either by reaction with the medium or by a reaction with
compound II, the competition between these two pathways depending on the
stability of the radical cation.
PMID- 10785392
TI - Solution structure of the antimicrobial peptide gaegurin 4 by H and 15N nuclear
magnetic resonance spectroscopy.
AB - Gaegurin 4 (GGN4) is a 37-residue antimicrobial peptide isolated from the skin of
a Korean frog, Rana rugosa. This peptide shows a broad range of activity against
prokaryotic cells but shows very little hemolytic activity against human red
blood cells. The solution structure of GGN4 was studied by using circular
dichroism (CD) and NMR spectroscopy. CD investigations revealed that GGN4 adopts
mainly an alpha-helical conformation in trifluoroethanol/water solution, in
dodecylphosphocholine and in SDS micelles, but adopts random structure in aqueous
solution. By using both homonuclear and heteronuclear NMR experiments, complete
1H and 15N resonance assignments were obtained for GGN4 in 50%
trifluoroethanol/water solution. The calculated structures of GGN4 consist of two
amphipathic alpha-helices extending from residues 2-10 and from residues 16-32.
These two helices are connected by a flexible loop spanning between the residues
11 and 15. By using enzyme digestion and matrix-assisted laser
desorption/ionization mass spectroscopy, we confirmed that GGN4 contains a
disulfide bridge formed between the residues Cys31 and Cys37 in its C-terminus.
The effect of disulfide bridge on the structure and the activity of GGN4 was
investigated. The reduced form of GGN4 revealed a similar activity and
conformation to native GGN4, suggesting that the disulfide bridge does not
strongly affect the conformation and the antimicrobial activity of GGN4.
PMID- 10785394
TI - The HIV-1(Lai) RNA dimerization. Thermodynamic parameters associated with the
transition from the kissing complex to the extended dimer.
AB - Retroviruses contain dimeric RNA consisting of two identical copies of the
genomic RNA. The interaction between these two RNA molecules occurs near their 5'
ends. A region upstream from the splice donor comprising an auto-complementary
sequence has been identified as being responsible for the initiation of the
formation of dimeric HIV-1(Lai) RNA. This region (SL1), part of the PSI
encapsidation domain, can adopt a stem-loop structure. It has already been shown
that this stem-loop structure can initiate the formation of two distinct dimers
differing in their thermostability: a loop-loop dimer or 'kissing complex' and an
extended dimer. We report here a study using UV and 1D NMR spectroscopy of the
dimerization of a short oligoribonucleotide (23 nucleotides) spanning nucleotides
248-270 of the HIV-1(Lai) SL1 sequence, in order to derive the thermodynamic
parameters associated with the transition from the loop-loop complex to the
extended dimer. The temperature dependence of the UV absorbency shows an
hypochromicity for this transition with a small enthalpy change equal to - 29.4
+/- 5 kcal x mol-1, together with a concentration independent transition which
implies a monomolecular reaction. On the other hand, our NMR results don't
indicate a dissociation of the GCGCGC sequence engaged in the loop-loop
interaction during the rearrangement of the loop-loop complex into the extended
dimer. Our data suggest that the loop-loop interaction is maintained during the
temperature dependent conformational change while the intramolecular base-pairing
of the stems is disrupted and then reconstituted to form an intermolecular base
pairing leading to an extended dimer.
PMID- 10785395
TI - Functional properties of recombinant Azospirillum brasilense glutamate synthase,
a complex iron-sulfur flavoprotein.
AB - Azospirillum brasilense glutamate synthase is a complex iron-sulfur flavoprotein
that catalyses the NADPH-dependent reductive transfer of glutamine amide group to
the C(2) carbon of 2-oxoglutarate to yield L-glutamate. Its catalytically active
alphabeta protomer is composed of two dissimilar subunits (alpha subunit, 164.2
kDa; beta subunit, 52.3 kDa) and contains one FAD (at Site 1, the pyridine
nucleotide site within the beta subunit), one FMN (at Site 2, the 2
oxoglutarate/L-glutamate site in the alpha subunit) and three different iron
sulfur clusters (one 3Fe-4S center on the alpha subunit and two 4Fe-4S clusters
of unknown location). A plasmid harboring the gltD and gltB genes, the genes
encoding the glutamate synthase beta and alpha subunits, respectively, each one
under the control of the T7/lac promoter of pET11a was found to be suitable for
the overproduction of glutamate synthase holoenzyme in Escherichia coli BL21(DE3)
cells. Recombinant A. brasilense glutamate synthase could be purified to
homogeneity from overproducing E. coli cells by ion exchange chromatography, gel
filtration and affinity chromatography on a 2',5' ADP-Sepharose 4B column. The
purified enzyme was indistinguishable from that prepared from Azospirillum cells
with respect to cofactor content, N-terminal sequence of the subunits,
aggregation state, kinetic and spectroscopic properties. The study of the
recombinant holoenzyme allowed us to establish that the tendency of glutamate
synthase to form a stable (alphabeta)4 tetramer at high protein concentrations is
a property unique to the holoenzyme, as the isolated beta subunit does not
oligomerize, while the isolated glutamate synthase alpha subunit only forms
dimers at high protein concentrations. Furthermore, the steady-state kinetic
analysis of the glutamate synthase reaction was extended to the study of the
effect of adenosine-containing nucleotides. Compounds such as cAMP, AMP, ADP and
ATP have no effect on the enzyme activity, while the 2'-phosphorylated analogs of
AMP and NADP(H) analogs act as inhibitors of the reaction, competitive with
NADPH. Thus, it can be ruled out that glutamate synthase reaction is subjected to
allosteric modulation by adenosine containing (di)nucleotides, which may bind to
the putative ADP-binding site at the C-terminus of the alpha subunit. At the same
time, the strict requirement of a 2'-phosphate group in the pyridine nucleotide
for binding to glutamate synthase (GltS) was established. Finally, by comparing
the inhibition constants exhibited by a series of NADP+ analogs, the contribution
to the binding energy of the various parts of the pyridine nucleotide has been
determined along with the effect of substituents on the 3 position of the
pyridine ring. With the exception of thio-NADP+, which binds the tightest to
GltS, it appears that the size of the substituent is the factor that affects the
most the interaction between the NADP(H) analog and the enzyme.
PMID- 10785396
TI - Domain organization of p130, PLC-related catalytically inactive protein, and
structural basis for the lack of enzyme activity.
AB - The 130-kDa protein (p130) was isolated as a novel inositol 1,4, 5-trisphosphate
[Ins(1,4,5)P3]-binding protein similar to phospholipase C-delta1 (PLC-delta1),
but lacking catalytic activity [Kanematsu, T., Takeya, H., Watanabe, Y., Ozaki,
S., Yoshida, M., Koga, T., Iwanaga, S. & Hirata, M. (1992) J. Biol. Chem. 267,
6518-6525; Kanematsu, T., Misumi, Y., Watanabe, Y., Ozaki, S., Koga, T., Iwanaga,
S., Ikehara, Y. & Hirata, M. (1996) Biochem. J. 313, 319-325]. To test
experimentally the domain organization of p130 and structural basis for lack of
PLC activity, we subjected p130 to limited proteolysis and also constructed a
number of chimeras with PLC-delta1. Trypsin treatment of p130 produced four major
polypeptides with molecular masses of 86 kDa, 55 kDa, 33 kDa and 25 kDa. Two
polypeptides of 86 kDa and 55 kDa started at Lys93 and were calculated to end at
Arg851 and Arg568, respectively. Using the same approach, it has been found that
the polypeptides of 33 kDa and 25 kDa are likely to correspond to regions between
Val569 and Arg851 and Lys869 and Leu1096, respectively. All the proteolytic sites
were in interconnecting regions between the predicted domains, therefore
supporting domain organization based on sequence similarity to PLC-delta1 and
demonstrating that all domains of p130, including the unique region at the C
terminus, are stable, tightly folded structures. p130 truncated at either or both
the N-terminus (94 amino acids) and C-terminus (851-1096 amino acids) expressed
in COS-1 cells showed no catalytic activity, indicating that p130 has
intrinsically no PLC activity. A number of chimeric molecules between p130 and
PLC-delta1 were constructed and assayed for PLC activity. It was shown that
structural differences in interdomain interactions exist between the two
proteins, as only some domains of p130 could replace the corresponding structures
in PLC-delta1 to form a functional enzyme. These results suggest that p130 and
the related proteins could represent a new protein family that may play some
distinct role in cells due to the capability of binding Ins(1,4,5)P3 but the lack
of catalytic activity.
PMID- 10785397
TI - Correct folding of a ribozyme induced by nonspecific macromolecules.
AB - The 50-nucleotide hammerhead ribozyme HH-S was tested for self-cleavage. The self
cleavage was very inefficient, and only 13% of HH-S was transformed to its
cleavage products. Surprisingly, the percentage of cleavage of HH-S was increased
to 30% when 1 microg of tRNA was added to the reaction mixture (6 microL). Other
macromolecules such as DNAs and proteins were examined to see if they also
augmented cleavage of HH-S, and it was found that most of the macromolecules
tested, except nucleotide monomers, did indeed enhance HH-S cleavage. The self
cleaving reaction was almost saturated in 30 min, and only 13% of HH-S was
cleaved at 37 degrees C for a 70-min reaction, indicating that 87% of HH-S was in
kinetically trapped inactive conformations. Time courses for the reaction of the
HH-S self-cleavage were also measured in the presence of tRNA, an
oligodeoxyribonucleotide, or BSA. Cleavage of HH-S, which had already reached a
plateau of 13% cleaved, increased gradually after the addition of the effector
molecules. The first-order rate constant for the self-cleavage reaction in the
absence of an effector was comparable to that in the presence of BSA, indicating
that the effector molecules do not affect the chemical step of self-cleavage.
These results demonstrate that a variety of nonspecific macromolecules can induce
conformational change of the hammerhead even in such a low concentration as
0.003% (w/v). This conformational change may occur by macromolecular collisions,
or nonspecific weak interactions between HH-S and effectors. Alternatively, a
molecular crowding effect may cause the conformational change.
PMID- 10785398
TI - Characterization and molecular cloning of two different type 2 ribosome
inactivating proteins from the monocotyledonous plant Polygonatum multiflorum.
AB - Leaves of the monocotyledonous plant Polygonatum multiflorum L. (Solomon's seal)
contain besides a monocot mannose-binding lectin two galactose/N
acetylgalactosamine (Gal/GalNAc)-binding type 2 ribosome-inactivating proteins
(RIPs). Both RIPs were purified using a combination of classical protein
purification techniques and affinity chromatography. Although both RIPs consist
of protomers of 65 kDa, the P. multiflorum RIP monomer (PMRIPm) occurs as a
monomer of approximately 60 kDa, whereas the tetramer (PMRIPt) is a tetramer of
240 kDa. Both RIPs exhibit similar RNA N-glycosidase activity but differ in their
specific agglutination activity and carbohydrate-binding specificity, PMRIPt
being a GalNAc-specific lectin whereas PMRIPm is Gal/GalNAc-specific. Toxicity
tests indicated that both Polygonatum RIPs exhibit a very low cytotoxicity
towards human and animal cells. Analysis of the genomic clones encoding both RIPs
revealed a high degree of sequence similarity to other type 2 RIPs. Molecular
modelling confirmed that both Polygonatum RIPs have a similar structure to ricin.
PMID- 10785399
TI - Phosphorylation of phosphodiesterase-5 by cyclic nucleotide-dependent protein
kinase alters its catalytic and allosteric cGMP-binding activities.
AB - In addition to its cGMP-selective catalytic site, cGMP-binding cGMP-specific
phosphodiesterase (PDE5) contains two allosteric cGMP-binding sites and at least
one phosphorylation site (Ser92) on each subunit [Thomas, M.K., Francis, S.H. &
Corbin, J.D. (1990) J. Biol. Chem. 265, 14971-14978]. In the present study, prior
incubation of recombinant bovine PDE5 with a phosphorylation reaction mixture
[cGMP-dependent protein kinase (PKG) or catalytic subunit of cAMP-dependent
protein kinase (PKA), MgATP, cGMP, 3-isobutyl-1-methylxanthine], shown earlier to
produce Ser92 phosphorylation, caused a 50-70% increase in enzyme activity and
also increased the affinity of cGMP binding to the allosteric cGMP-binding sites.
Both effects were associated with increases in its phosphate content up to 0.6
mol per PDE5 subunit. Omission of any one of the preincubation components caused
loss of stimulation of catalytic activity. Addition of the phosphorylation
reaction mixture to a crude bovine lung extract, which contains PDE5, also
produced a significant increase in cGMP PDE catalytic activity. The increase in
recombinant PDE5 catalytic activity brought about by phosphorylation was time
dependent and was obtained with 0.2-0.5 microM PKG subunit, which is
approximately the cellular level of this enzyme in vascular smooth muscle.
Significantly greater stimulation was observed using cGMP substrate
concentrations below the Km value for PDE5, although stimulation was also seen at
high cGMP concentrations. Considerably higher concentration of the catalytic
subunit of PKA than of PKG was required for activation. There was no detectable
difference between phosphorylated and unphosphorylated PDE5 in median inhibitory
concentration for the PDE5 inhibitors, sildenafil, or zaprinast 3-isobutyl-1
methylxanthine. Phosphorylation reduced the cGMP concentration required for half
maximum binding to the allosteric cGMP-binding sites from 0.13 to 0.03 microM.
The mechanism by which phosphorylation of PDE5 by PKG could be involved in
physiological negative-feedback regulation of cGMP levels is discussed.
PMID- 10785400
TI - Interferon-alpha synergistically enhances induction of interleukin-6 by double
stranded RNA in HeLa cells.
AB - Double stranded RNA (dsRNA), an intermediate that is common during viral
infection, directly induces much higher levels of expression of interleukin-6 (IL
6) mRNA than does the cytokine IL-1beta. Interferon alpha (IFNalpha) by itself
does not induce expression of IL-6; nonetheless, IFNalpha pretreatment
dramatically enhances IL-6 induction by dsRNA but not by IL-1beta. Mutation of
either the activating transcription factor/cyclic AMP response element binding
protein (ATF/CREB) or the NF-IL-6 binding element within the IL-6 promoter
eliminates most responsiveness of CAT reporter constructs to either dsRNA or to
IL-1beta. IFNalpha pretreatment partially restores responsiveness to dsRNA but
not to IL-1beta when either the ATF/CREB site or the NF-IL-6 site is mutated, but
at least one of these sites must be intact for responsiveness to be restored.
Mutation of the kappaB binding site in the IL-6 promoter eliminates
responsiveness to either IL-1beta or to dsRNA, and pretreatment with IFNalpha
does not restore any responsiveness. Incubation with dsRNA leads to a decrease in
protein translation, especially in cells that have been pretreated with IFNalpha.
Nonetheless, IFNalpha pretreatment followed by dsRNA leads to very high IL-6
protein levels. These studies demonstrate that major differences exist in the
induction of IL-6 at both the mRNA and protein levels by dsRNA compared to
cytokines and that IFNalpha pretreatment selectively enhances IL-6 induction by
dsRNA but not by IL-1beta. The high levels of IL-6 expression that result when
cells encounter class I IFN prior to dsRNA suggest a mechanism for a heightened
host response to viral infection with heightened production of this pleotropic
cytokine.
PMID- 10785401
TI - Analysis of the molecular composition of Ro ribonucleoprotein complexes.
Identification of novel Y RNA-binding proteins.
AB - Human Ro ribonucleoproteins (RNPs) are composed of one of the four small Y RNAs
and at least two proteins, Ro60 and La; association of additional proteins
including the Ro52 protein and calreticulin has been suggested, but clear-cut
evidence is still lacking. Partial purification of Ro RNPs from HeLa S100
extracts allowed characterization of several subpopulations of Ro RNPs with
estimated molecular masses of between 150 and 550 kDa. The majority of these
complexes contained Ro60 and La, whereas only a small proportion of Ro52 appeared
to be associated with Ro RNPs. To identify novel Y RNA-associated proteins in
vitro, binding of cytoplasmic proteins to biotinylated Y RNAs was investigated.
In these reconstitution experiments, several proteins with estimated molecular
masses of 80, 68, 65, 62, 60 and 53 kDa, the latter two being immunologically
distinct from Ro60 and Ro52, respectively, appeared to bind specifically to Y
RNAs. Furthermore, autoantibodies to these proteins were found in sera from
patients with systemic lupus erythematosus. The proteins bound preferentially to
Y1 and Y3 RNA but, with the exception of the 53-kDa protein, only weakly to Y4
RNA and not at all to Y5 RNA. Coprecipitation of the 80, 68, 65, and 53-kDa
proteins by antibodies to Ro60 and La was observed, suggesting that at least a
proportion of the novel proteins may reside on the same particles as La and/or
Ro60. Finally, the binding sites for these proteins on Y1 RNA were clearly
distinct from the Ro60-binding site involving a portion of the large central loop
2, which was found to be indispensable for binding of the 80, 68, 65 and 53-kDa
proteins, as well as the stem 3-loop 3 and stem 2-loop 1 regions. Interestingly,
truncation of the La-binding site resulted in decreased binding of the novel
proteins (but not of Ro60), indicating La to be required for efficient
association. Taken together, these results suggest the existence of further
subpopulations of Ro RNPs or Y RNPs, consistent with the heterogeneous
characteristics observed for these particles in the biochemical fractionation
experiments.
PMID- 10785402
TI - Aspartate aminotransferase from the Antarctic bacterium Pseudoalteromonas
haloplanktis TAC 125. Cloning, expression, properties, and molecular modelling.
AB - The gene encoding aspartate aminotransferase from the psychrophilic bacterium
Pseudoalteromonas haloplanktis TAC 125 was cloned, sequenced and overexpressed in
Escherichia coli. The recombinant protein (PhAspAT) was characterized both at the
structural and functional level in comparison with the E. coli enzyme (EcAspAT),
which is the most closely related (52% sequence identity) bacterial counterpart.
PhAspAT is rapidly inactivated at 50 degrees C (half-life = 6.8 min), whereas at
this temperature EcAspAT is stable for at least 3 h. The optimal temperature for
PhAspAT activity is approximately 64 degrees C, which is some 11 degrees C below
that of EcAspAT. The protein thermal stability was investigated by following
changes in both tryptophan fluorescence and amide ellipticity; this clearly
suggested that a first structural transition occurs at approximately 50 degrees C
for PhAspAT. These results agree with the expected thermolability of a
psychrophilic enzyme, although the observed stability is much higher than
generally found for enzymes isolated from cold-loving organisms. Furthermore, in
contrast with the higher efficiency exhibited by several extracellular
psychrophilic enzymes, both kcat and kcat/Km of PhAspAT are significantly lower
than those of EcAspAT over the whole temperature range. This behaviour possibly
suggests that the adaptation of this class of endocellular enzymes to a cold
environment may have only made them less stable and not more efficient. The
affinity of PhAspAT for both amino-acid and 2-oxo-acid substrates decreases with
increasing temperature. However, binding of maleate and 2-methyl-L-aspartate,
which both inhibit the initial steps of catalysis, does not change over the
temperature range tested. Therefore, the observed temperature effect may occur at
any of the steps of the catalytic mechanism after the formation of the external
aldimine. A molecular model of PhAspAT was constructed on the basis of sequence
homology with other AspATs. Interestingly, it shows no insertion or extension of
loops, but some cavities and a decrease in side chain packing can be observed.
PMID- 10785403
TI - Study of HIV-2 primer-template initiation complex using antisense
oligonucleotides.
AB - HIV-2 reverse transcription is initiated by the retroviral DNA polymerase
(reverse transcriptase) from a cellular tRNALys3 partially annealed to the primer
binding site in the 5'-region of viral RNA. The HIV-2 genome has two A-rich
regions upstream of the primer binding site. In contrast to HIV-1 RNA, no direct
evidence of interactions with the U-rich anticodon loop of tRNALys3 has been
described to date. Here we address the question of the potential role of the
interactions between these highly structured regions in the initiation of viral
DNA synthesis. To evaluate this we used an antisense approach, first validated in
our in vitro HIV-1 reverse transcription system. Annealing of the antisense
oligonucleotides to the pre-primer binding site (the upstream region contiguous
to the HIV-2 primer binding site) was determined in the presence of native
tRNALys3 or synthetic primers. Using natural and chemically modified antisense
oligonucleotides we found that interactions between the anticodon of tRNALys3 and
an A-rich loop of viral RNA led to an important destabilization of the pre-primer
binding site; this region became accessible to anti-pre-primer binding site
oligonucleotides in a cooperative manner. These studies allowed to identify an A
rich region in HIV-2ROD RNA capable of interacting with tRNALys3. Better
knowledge of these interactions is very important for understanding the
primer/template positioning in the early steps of HIV-2 reverse transcription.
PMID- 10785404
TI - Identification of ubiquitinated repeats in human erythroid alpha-spectrin.
AB - The spectrin role(s) is (are) very important for the shape and the physical
properties of red cells, such as deformability and resistance to mechanical
stresses. Moreover a variety of spectrin diseases are known. We have previously
demonstrated [Corsi, D., Galluzzi, L., Crinelli, R. & Magnani, M. (1995) J. Biol.
Chem. 270, 8928-8935] that human erythroid alpha-spectrin is ubiquitinated in
vitro and in vivo. In order to define the ubiquitinated repeats of this long
protein and find out a possible function, we have produced recombinant peptides
encompassing the alphaIII-, alphaIV-, alphaV- and EF hand domains of alpha
spectrin chain. These peptides were tested in in vitro ubiquitin conjugation
assays and two regions susceptibles to ubiquitination were found. The first one,
in the alphaIV-domain, includes the repeat 17 and the second one, in the alphaV
domain, includes the repeat 20 and a part of repeat 21. We also demonstrated that
the susceptibility to ubiquitination of the alphaV-domain is reduced by
interaction with the corresponding portion of beta-spectrin chain (betaIV
domain). Thus, at least ubiquitination of alphaV-domain is susceptible to
cytoskeleton assembly and spectrin dimerization.
PMID- 10785405
TI - Differential gene expression by endothelial cells in distinct angiogenic states.
AB - Angiogenesis is a complex process that can be regarded as a series of sequential
events comprising a variety of tissue cells. The major problem when studying
angiogenesis in vitro is the lack of a model system mimicking the various aspects
of the process in vivo. In this study we have used two in vitro models, each
representing different and distinct aspects of angiogenesis. Differentially
expressed genes in the two culture forms were identified using the suppression
subtractive hybridization technique to prepare subtracted cDNA libraries. This
was followed by a differential hybridization screen to pick up overexpressed
clones. Using comparative multiplex RT-PCR we confirmed the differential
expression and showed differences up to 14-fold. We identified a broad range of
genes already known to play an important role during angiogenesis like Flt1 or
TIE2. Furthermore several known genes are put into the context of endothelial
cell differentiation, which up to now have not been described as being relevant
to angiogenesis, like NrCAM, Claudin14, BMP-6, PEA-15 and PINCH. With ADAMTS4 and
hADAMTS1/METH-1 we further extended the set of matrix metalloproteases expressed
and regulated by endothelial cells.
PMID- 10785406
TI - Rising drug costs: the impact on dermatology.
AB - In the US prescription drug costs are rising faster than any other component of
health care expenditures, and show no signs of slowing. Spending on prescription
drugs has been estimated by the Health Care Finance Administration (HCFA) to be
rising by approximately 12% per year, more than twice the rate for national
health care expenditures (5.1%). Factors driving the rise in prescription drug
costs include the introduction of new drugs, and consumer demand.
PMID- 10785407
TI - Herbal anti-inflammatory agents for skin disease.
AB - Herbs have been used in clinical medicine for thousands of years. However, it is
only in recent times that we have been able to employ scientific methods to prove
the efficacy of many of these herbs and to give us a better understanding of
their mechanisms of action. This article will focus on the use of herbs in
various dermatological conditions characterized by inflammation and pruritus.
Topical preparations of many of these herbs are more commonplace in Europe.
However, their availability is increasing in the US. As this is occurring we are
witnessing a growing marriage between alternative and traditional medicines.
PMID- 10785408
TI - Induction of choline acetyltransferase activity in cholinergic neurons by
stolonidiol: structure-activity relationship.
AB - The effect of stolonidiol (1), a bioactive marine diterpenoid from the Japanese
soft coral Clavularia sp., on choline acetyltransferase (ChAT) activity was
examined using cultured cholinergic neurons. Stolonidiol (1) showed potent ChAT
inducible activity in primary cultured basal forebrain cells and clonal septal
SN49 cells, suggesting that it may act as a potent neurotrophic factor-like agent
on the cholinergic nervous system. Further expansion of the structure-activity
relationship to include stolonidiol (1) and its derivatives demonstrated that the
exo-methylene group and the epoxide group are essential for ChAT-inducing
activity. Stolonidiol (1) showed the highest activity among the test samples.
PMID- 10785409
TI - Sesquiterpene coumarins and related derivatives from Ferula pallida.
AB - Six new compounds-two sesquiterpene coumarins, pallidones A and B (1, 2), and
four related derivatives, pallidones C-F (3-6), as well as two known
sesquiterpene coumarins, feselol (7) and conferol (8), have been isolated from
the EtOAc extracts of the roots of Ferula pallida. All structures of these
compounds were determined on the basis of spectral evidence, especially 2D NMR
((1)H-(1)H COSY, HSQC, HMBC, and NOESY) and HRMS. The possible biosynthetic
pathway of pallidones C-F (3-6) is discussed.
PMID- 10785410
TI - Cytotoxic prenylxanthones from Garcinia bracteata.
AB - Bioassay-guided fractionation of a leaf extract of G. bracteata has yielded six
new prenylxanthones, bractatin (1), isobractatin (2), 1-O-methylbractatin (3), 1
O-methylisobractatin (4), 1-O-methyl-8-methoxy-8,8a-dihydrobractatin (5), and 1-O
methylneobractatin (6). The structures of these compounds have been elucidated by
spectroscopic means (NMR, MS), literature data, and X-ray crystallographic
analysis of 2. These compounds possess significant cytotoxicity against the KB
cell line.
PMID- 10785411
TI - New bisindole alkaloids of the topsentin and hamacanthin classes from the
Mediterranean marine sponge Rhaphisia lacazei.
AB - Chemical investigation of the Et(2)O extract of the marine sponge Rhaphisia
lacazei resulted in the isolation of 13 pure bisindole alkaloids (1-13).
Compounds (1-6) belong to the class of topsentins and have already been
described. Compounds 7-13 are new products, closely related to the class of
hamacanthins. The major compounds 1-3 were tested in vitro for antitumor
activity; compounds 2 and 3 showed antiproliferative activity against human
bronchopulmonary cancer cells (NSCLC-N6) with an IC(50) of 12 and 6.3 microg/mL,
respectively.
PMID- 10785412
TI - New sesquiterpene/quinones from two sponges of the genus Hyrtios.
AB - Two sponges of the genus Hyrtios have been found to contain new
sesquiterpene/quinones identified by detailed spectroscopic analysis. Four new
compounds with a 4,9-friedodrim-3-ene skeleton [hyrtiophenol (2), 5
epihyrtiophenol (3), 18-hydroxy-5-epihyrtiophenol (4), and 18-hydroxyhyrtiophenol
(5)] were isolated from Hyrtios sp. (Seychelles Islands) along with
isospongiaquinone (1). Moreover, the new compound 21-hydroxy-19-methoxyarenarone
(8), which bears the 4, 9-friedodrim-4(15)-ene skeleton, was isolated from
Hyrtios tubulatus (Curacao) along with arenarol (6) and 5-epiilimaquinone (7).
Assignment of the (13)C NMR signals of four types of 4, 9-friedodrimene skeletons
found in sponges is presented.
PMID- 10785413
TI - Bioactive compounds from Combretum erythrophyllum.
AB - A methanol extract of Combretum erythrophyllum showed inhibitory bioactivities in
a yeast-based microtiter assay for DNA-damaging agents. Bioassay-guided
fractionation of this extract yielded two known bioactive compounds,
combretastatin A-1 and (-)-combretastatin, and two new bioactive glucosides,
combretastatin A-1 2'-beta-D-glucoside (1) and combretastatin B-1 2'-beta-D
glucoside (2). The structures of the new compounds were assigned by (1)H and
(13)C NMR, DEPT, HMQC, and HMBC spectra.
PMID- 10785414
TI - Malevamides A-C, new depsipeptides from the marine cyanobacterium Symploca laete
viridis.
AB - Three new depsipeptides, malevamides A-C (1-3), were isolated from the
cyanobacterium Symploca laete-viridis collected off the south shore of Oahu,
Hawaii. Compounds 1-3 were identified by spectral methods, and partial
stereochemical assignments were made by chiral HPLC of the hydrolyzed compounds.
At a concentration of 2 microg/mL, compounds 1-3 were inactive against P-388, A
549, and HT-29 cancer cells.
PMID- 10785415
TI - New xenicane diterpenes isolated from the acetone extract of the soft coral Xenia
florida.
AB - Six new xenicane diterpenes have been isolated from the acetone extract of the
soft coral Xenia florida. Two of them are diterpenes containing a bicyclic
[4.3.1] ring system. Three of them seem to be precursors for diterpenes
possessing the bicyclic [4.3.1] ring system. One is a common monocarbocyclic
diterpene with a cyclononane skeleton.
PMID- 10785416
TI - Flavonol-cinnamate cycloadducts and diamide derivatives from Aglaia laxiflora.
AB - Leaf extracts of the Malaysian plant Aglaia laxiflora provided two cytotoxic
compounds, a new rocaglaol rhamnoside (1), a known rocaglaol (2), new (but
inactive) flavonol-cinnamaminopyrrolidine adducts (3-6), and their probable
biosynthetic precursors (7 and trimethoxyflavonol). All structures were
elucidated primarily by 2D NMR spectroscopy. The structure and stereochemistry of
aglaxiflorin A (3) were confirmed by single-crystal X-ray crystallography.
PMID- 10785417
TI - Aporphine glycosides from Stephania cepharantha seeds.
AB - Two new aporphine glycosides, stesakine-9-O-beta-D-glucopyranoside (1) and N
methylasimilobine-2-O-beta-D-glucopyranoside (2), were isolated from the seeds of
Stephania cepharantha cultivated in Japan, together with 16 known alkaloids. The
structures of 1 and 2 were spectroscopically determined by comparison of their
(1)H and (13)C NMR data with those of stesakine (11) and N-methylasimilobine
(12), respectively.
PMID- 10785418
TI - Halogenated boldine derivatives with enhanced monoamine receptor selectivity.
AB - (S)-(+)-Boldine (1) was brominated, chlorinated, and iodinated using molecular
bromine in acetic acid or N-halosuccinimides in trifluoroacetic acid. Initial
halogenation occurs at C-3, followed (in the cases of chlorine and bromine) by
the less reactive C-8, to afford 3-haloboldines- and 3,8-dihaloboldines (2-5).
Using a 2:1 ratio of N-iodosuccinimide to boldine, however, only the 3-iodo
derivative 6 was obtained. Radioligand binding studies of these products showed
that halogenation of boldine at C-3 favors affinity for D(1)- (vs D(2)-)
dopaminergic receptors, attaining a low nanomolar IC(50) value in the case of 3
iodoboldine (6).
PMID- 10785419
TI - Coumarins from the fruits of Cnidium monnieri.
AB - Two novel biscoumarins, cnidimonal (1) and cnidimarin (2), and two new coumarin
derivatives, 5-formylxanthotoxol (3) and 2'-deoxymeranzin hydrate (4), were
isolated from a traditional Chinese crude drug, the fruits of Cnidium monnieri,
together with 15 known compounds. Among the known compounds, five of the minor
compounds were isolated for the first time from this plant. The structures of 1-4
were determined with the use of spectroscopic methods.
PMID- 10785420
TI - Biotransformation of testosterone and pregnenolone catalyzed by the fungus
Botrytis cinerea.
AB - Testosterone (1), a male sex hormone, and pregnenolone (2), a precursor of many
steroidal hormones, were oxidized by fermentation with the fungus Botrytis
cinerea. The fermentation of 1 yielded 7beta,17beta-dihydroxyandrostan-3-one (3)
(73%) in a yield comparable to chemical transformations. Fermentation of 2 by the
same fungus afforded a major metabolite 3beta,11alpha, 16beta-trihydroxypregn-5
en-20-one (4) (39%) along with a minor metabolite 11alpha,16beta-dihydroxypregn-4
ene-3,20-dione (5) (6%). The metabolites are characterized by detailed physical
and spectroscopic studies.
PMID- 10785421
TI - Cytotoxic constituents of the roots of Ekmanianthe longiflora.
AB - Bioactivity-directed fractionation of the CHCl(3) extract of the roots of
Ekmanianthe longiflora resulted in the isolation of three new natural products,
(2R,3R,4R)-3,4-dihydro-3, 4-dihydroxy-2-(3-methyl-2-butenyl)-1(2H)-naphthalenone
(1), (2S,3R, 4R)-3,4-dihydro-3, 4-dihydroxy-2-(3-methyl-2-butenyl)-1(2H)
naphthalenone (2), and (2R, 3aR,9R,9aR)-9-hydroxy-2-(1-hydroxy-1-methylethyl)
2,3,3a,4,9 , 9a-hexahydro-naphtho[2,3-b]furan-4-one (3), together with the known
compounds 2-(1-hydroxyethyl)naphtho[2,3-b]furan-4,9-quinone (4), 2
acetylnaphtho[2,3-b]furan-4,9-quinone (5), dehydro-iso-alpha-lapachone (6), alpha
lapachone (7), catalponol, and epi-catalponol. The structures of 1-3 were
determined using a combination of NMR spectroscopic techniques, and the absolute
configurations of compounds 1 and 2 were obtained using Mosher ester methodology.
Compounds 4-6 showed significant cytotoxicity in a panel of human cancer cells.
alpha-Lapachone (7) exhibited only marginal activity, and catalponol and epi
catalponol were inactive in this regard. When tested at 72 mg/kg/injection in an
in vivo mouse P-388 leukemia system, compound 4 was inactive (110% T/C).
PMID- 10785422
TI - Quadranosides I-V, new triterpene glucosides from the seeds of Combretum
quadrangulare.
AB - Five new triterpene glucosides, quadranosides I-V (1-5), have been isolated from
a MeOH extract of the seeds of Combretum quadrangulare, together with 13 known
compounds. The structures of compounds 1-5 were elucidated on the basis of
spectroscopic analysis. Among the new triterpene glucosides, three compounds (1,
2, 5) showed significant hepatoprotective effects against D-galactosamine (D
GalN)/tumor necrosis factor-alpha (TNF-alpha)-induced cell death in primary
cultured mouse hepatocytes.
PMID- 10785423
TI - Mololipids, a new series of anti-HIV bromotyramine-derived compounds from a
sponge of the order verongida.
AB - A new series of lipids called mololipids have been identified from an Hawaiian
sponge of the order Verongida. The structures of these lipids was deduced from
spectroscopic data of the lipid mixture combined with GC-MS analysis. The core of
this novel series of lipids is a bromotyramine homoserine-derived moiety known as
moloka'iamine (1) which is found in many Verongid sponge metabolites.
Moloka'iamine forms bisamides with a diverse series of fatty acids and the
mololipids mixture (2) was active against HIV-1 with an EC(50) of 52.2 microM
without cytotoxicity in human lymphocytes (IC(50) > 100 microM).
PMID- 10785424
TI - A new isoflavone from Genista corsica.
AB - A new isoflavone (1), dihydroisoderrondiol [(3' 'S,4' 'R)-5,7,3' ', 4' '
tetrahydroxy-2' ',2' '-dimethyl-3' ',4' '-dihydropyrano(5' ',6' ';3' ',4'
')isoflavone], was isolated from aerial parts of Genista corsica, together with
11 previously known compounds [daidzein, isoprunetin, isoderrone (2),
ficuisoflavone (3), luteolin, luteolin 4'-O-beta-glucoside, luteolin 7-O-beta
glucoside, taxifolin, 5-methoxytaxifolin, sucrose, and D-pinitol]. The structure
of 1 was elucidated by spectroscopic methods.
PMID- 10785425
TI - 7-O-Methyltetrahydroochnaflavone, a new biflavanone from Ochna beddomei.
AB - 7-O-Methyltetrahydroochnaflavone (1), a new biflavanone, together with nine known
flavonoids, afrormosin (2), 2,3-dihydroochnaflavone 7-O-methyl ether (3),
kaempferol (4), 2,3-dihydroochnaflavone (5), ochnaflavone (6), (-)-epicatechin
(7), kaempferol 3-O-rhamnoside (8), taxifolin 3-O-rhamnoside (9), and kaempferol
3-O-glucoside (10), were isolated from the leaves of Ochna beddomei, and the
structures were elucidated by spectral and chemical studies.
PMID- 10785426
TI - Clerodane diterpenes from Tinospora rumphii.
AB - Two new diterpenes (1 and 2) were obtained from the leaves of Tinospora rumphii,
along with the known compounds tinotufolin D and vitexilactone. The structures of
compounds 1 and 2 were established on the basis of spectroscopic studies.
PMID- 10785427
TI - 17-Epiacnistin-A, a further withanolide from the leaves of Discopodium
penninervium.
AB - A novel withanolide (1) has been isolated from the leaves of Discopodium
penninervium and identified as 17-epiacnistin-A on the basis of spectroscopic and
X-ray diffraction data.
PMID- 10785428
TI - New lanostanoids of Ganoderma tsugae.
AB - Three new compounds, (24R, S)-3alpha-acetoxy-24-hydroxy-5alpha-lanosta-8,25-di en
21-oic acid, named tsugaric acid C (1); 3alpha-acetoxy-5alpha-lanosta-8, 24-diene
21-O-beta-D-xyloside, named tsugarioside B (2); and 3alpha-acetoxy-(Z)-24-methyl
5alpha-lanosta-8,23,25-tr ien-21-oic acid ester beta-D-xyloside, named
tsugarioside C (3), and a mixture of two known steroids were isolated from the
fruit bodies of Ganoderma tsugae. The structures of 1-3 were determined by
spectral and chemical methods. The cytotoxic activity of the lanostanoid
constituents of this fungus was evaluated against several different cancer cell
lines.
PMID- 10785429
TI - Sulcatin, a novel antiproliferative N-methylpyridinium alkaloid from the ascidian
Microcosmus vulgaris.
AB - A new N-methylpyridinium alkaloid, with an interesting antiproliferative activity
in vitro, has been isolated from the Mediterranean tunicate Microcosmus vulgaris.
Its structure has been elucidated by spectroscopic analysis, including extensive
2D NMR experiments.
PMID- 10785430
TI - Sesquiterpene phenylpropanoid and sesquiterpene chromone derivatives from Ferula
pallida.
AB - Four novel compounds-two sesquiterpene phenylpropanoid derivatives, pallidones G
(1) and H (2), and two sesquiterpene chromone derivatives, pallidones I (3) and J
(4)-have been isolated from the roots of Ferula pallida. Their structures were
determined on the basis of NMR and HREIMS evidence.
PMID- 10785431
TI - Haliclonyne, a new highly oxygenated polyacetylene from the marine sponge
Haliclona species.
AB - Haliclonyne (1), a new polyacetylene carboxylic acid, has been isolated from the
marine sponge Haliclona sp. collected in the Gulf of Eilat. The structure of
haliclonyne, a C(47) oxo-octahydroxy-dienetetrayne carboxylic acid, was
elucidated by interpretation of NMR and mass spectra of 1 and two of its
derivatives.
PMID- 10785432
TI - Scalarane and homoscalarane compounds from the nudibranchs Glossodoris sedna and
Glossodoris dalli: chemical and biological properties.
AB - A series of homoscalarane and scalarane compounds (2-7) have been isolated from
two distinct species of Pacific Glossodoris nudibranchs. The structure and
elucidation of the relative stereochemistry of the new metabolites 2 and 3 were
obtained by spectroscopic methods. Compound 2 was ichthyotoxic at 0.1 ppm against
Gambusia affinis and showed moderate activity (IC(50) 18 microM) to inhibit
mammalian phospholipase A(2).
PMID- 10785433
TI - HIV-inhibitory cembrane derivatives from a Philippines collection of the soft
coral Lobophytum species.
AB - Bioassay-guided fractionation of an aqueous extract of a Philippine Islands
collection of the soft coralLobophytum sp. concentrated its HIV-inhibitory
activity into fractions rich in cembranoid diterpenes. Lobohedleolide (1), (7Z)
lobohedleolide (2), and a new compound, 17-dimethylaminolobohedleolide (3), were
purified from these fractions by HPLC. The structures of compounds 1-3 were
elucidated by spectroscopic analyses and by comparison of their spectral data
with previously reported values. The relative stereochemistry of the gamma
lactone ring substituents of 3 was determined by 1D NOESY experiments. While
several other cembranoids that contain a dimethylamino functional group have been
reported from the soft coral Sinularia sp., compound 3 represents the first
cembrane diterpene with this functional group isolated from a Lobophytum species.
Diterpenoids 1-3 exhibited moderate HIV-inhibitory activity (EC(50) approximately
3-5 microg/mL) in a cell-based in vitro anti-HIV assay.
PMID- 10785434
TI - Two novel secoergosterols from the fungus Tylopilus plumbeoviolaceus.
AB - Two novel secoergosterols, 3beta-hydroxy-8alpha,9alpha-oxido-8, 9-secoergosta
7,9(11),22-triene (tylopiol A) (1) and 3beta-hydroxy-8alpha,9alpha-oxido-8,9
secoergosta-7,22 -dien-12-one (tylopiol B) (2), were isolated from the fresh
fruit bodies of Tylopilus plumbeoviolaceus, along with three known compounds,
ergosta-7,22-dien-3beta-ol, uridine, and allitol. Their structures were
elucidated by NMR techniques, including (1)H NMR, (13)C NMR, HMQC, HMBC, and MS.
The structure and stereochemistry of compound 1 were demonstrated by X-ray
crystallography.
PMID- 10785435
TI - A cytotoxic sesquiterpene caffeate from the liverwort Bazzanianovae-zelandiae.
AB - Extracts of the liverwort Bazzania novae-zelandiae were cytotoxic, with selective
activity against human tumor cell lines. Bioactivity-directed isolation work
showed that the new compound naviculyl caffeate (1) was the main cytotoxin. This
structure was confirmed by synthesis from the co-occurring sesquiterpene
naviculol (2).
PMID- 10785436
TI - Stephanotic acid, a novel cyclic pentapeptide from the stem of Stephanotis
floribunda.
AB - The stem of Stephanotis floribunda afforded a new cyclic pentapeptide stephanotic
acid (1), possessing a novel 6-(leucin-3'-yl) tryptophan skeleton. The structure
of 1 was assigned on the basis of extensive NMR experiments and a chemical
reaction and shown to be closely related to the bicyclic octapeptide moroidin
(3), a toxin from Laportea moroides.
PMID- 10785437
TI - Long-range (1)H-(15)N heteronuclear shift correlation at natural abundance.
AB - Despite the inherently low sensitivity of (15)N NMR because of its low
gyromagnetic ratio (gamma(N)) and its relatively low natural abundance (0.37%),
this important nuclide still has useful potential as a structural probe even at
natural abundance. Inverse-detected NMR methods coupled with major advances in
NMR probe designs have made it possible to acquire long-range (1)H-(15)N
heteronuclear shift correlation data on samples as small as a micromole
overnight. Chemical shift referencing schemes for (15)N and the range of (15)N
shifts are discussed, followed by a discussion of the currently available pulse
sequences, pulse calibration, parametrization and processing of long-range (1)H
(15)N data, and the implications of probe selection. These topics are followed by
a review of the applications contained in the literature that have utilized (1)H
(15)N heteronuclear shift correlation experiments at natural abundance, with
emphasis placed on the observed long-range coupling pathways.
PMID- 10785438
TI - Inhalation of low concentrations of toluene induces persistent effects on a
learning retention task, beam-walk performance, and cerebrocortical size in the
rat.
AB - The organic solvent toluene is widely used in industry. The threshold limit value
for extended occupational exposure to toluene is presently set to 200 ppm in the
United States. We have investigated the effect of an inhalation exposure of 80
ppm for 4 weeks (6 h/day, 5 days/week), followed by a postexposure period of at
least 4 weeks, on behavior and brain features in the rat. Toluene exposure
appeared to affect spatial memory, since toluene-exposed rats showed a longer
time in the correct quadrant in a Morris swim maze. This effect may indicate that
the exposed rats used their praxis strategy longer before they started to look
for the platform elsewhere. Toluene-exposed rats showed trends for increases in
both locomotion and rearing behaviors and a significantly reduced beam-walk
performance. The area of the cerebral cortex, especially the parietal cortex, was
decreased by 6-10% in toluene-exposed rats, as shown by magnetic resonance
imaging of living rats and autoradiograms of frozen brain sections. The K(D) and
B(max) values of the dopamine D(3) agonist [(3)H]PD 128907 were not affected by
toluene, as measured in caudate-putamen and subcortical limbic area using
biochemical receptor binding assays and in caudate-putamen and islands of Calleja
using quantitative receptor autoradiography. Hence, previously demonstrated
persistent effects by toluene on the binding characteristics of radioligands
binding to both D(2) and D(3) receptors seem to indicate a persistent effect of
toluene selectively on dopamine D(2) receptors. Taken together, the present
results indicate that exposure to low concentrations of toluene leads to
persistent effects on cognitive, neurological, and brain-structural properties in
the rat.
PMID- 10785439
TI - DNA damage and activated caspase-3 expression in neurons and astrocytes: evidence
for apoptosis in frontotemporal dementia.
AB - Frontotemporal dementia (FTD) is a neurodegenerative disease which affects mainly
the frontal and anterior temporal cortex. It is associated with neuronal loss,
gliosis, and microvacuolation of lamina I to III in these brain regions. In
previous studies we have described neurons with DNA damage in the absence of
tangle formation and suggested this may result in tangle-independent mechanisms
of neurodegeneration in the AD brain. In the present study, we sought to examine
DNA fragmentation and activated caspase-3 expression in FTD brain where tangle
formation is largely absent. The results demonstrate that numerous nuclei were
TdT positive in all FTD brains examined. Activated caspase-3 immunoreactivity was
detected in both neurons and astrocytes and was elevated in FTD cases as compared
to control cases. A subset of activated caspase-3-positive cells were also TdT
positive. In addition, the cell bodies of a subset of astrocytes showed enlarged,
irregular shapes, and vacuolation and their processes appeared fragmented. These
degenerating astrocytes were positive for activated caspase-3 and colocalized
with robust TdT-labeled nuclei. These findings suggest that a subset of
astrocytes exhibit degeneration and that DNA damage and activated caspase-3 may
contribute to neuronal cell death and astrocyte degeneration in the FTD brain.
Our results suggest that apoptosis may be a mechanism of neuronal cell death in
FTD as well as in AD (228).
PMID- 10785440
TI - An altered histaminergic innervation of the substantia nigra in Parkinson's
disease.
AB - The central histaminergic system is one of the subcortical aminergic projection
systems involved in several regulatory functions. The central dopaminergic and
histaminergic systems interact extensively, but little is known about the
histaminergic system in diseases affecting the dopaminergic neurons. The
distribution of histaminergic fibers in the substantia nigra (SN) in postmortem
brain samples from patients suffering from Parkinson's disease (PD) and normal
controls was examined with a specific immunohistochemical method. Direct
connections between dopaminergic neurones and histaminergic fibers were observed.
Histamine in human SN was stored in fibers and varicosities. Sites of histamine
formation were examined by l-histidine decarboxylase in situ hybridization. In
both normal and PD brains HDC mRNA was found only in posterior hypothalamus and
not in SN. The presence of histaminergic innervation of the human substantia
nigra pars compacta (SNc) and reticulata (SNr), paranigral nucleus, radix of
oculomotor nerve, and parabrachial pigmented nucleus was demonstrated. The
density of histaminergic fibers in the middle portion of SNc and SNr was
increased in brains with PD. In PD the morphology of histaminergic fibers was
also altered; they were thinner than in controls and had enlarged varicosities.
An increase of histaminergic innervation may reflect a compensatory event due to
deficiency of, e.g., dopamine or a putative fiber growth inhibitory factor.
Whether the changes seen in histaminergic fibers in PD are primary or secondary
remains to be investigated.
PMID- 10785441
TI - The properties of hNT cells following transplantation into the subventricular
zone of the neonatal forebrain.
AB - Neurons derived from the human teratocarcinoma cell line (hNT) establish
structural polarity and a fully mature phenotype following transplantation into
the rodent brain. Here we describe the transplantation of hNT cells into the
anterior part of neonatal subventricular zone (SVZa), which is a prolific region
of neuronal progenitor cells. Ordinarily, the progeny of endogenous or
homotopically transplanted SVZa cells migrate to the olfactory bulb (OB) along a
restricted pathway, the rostral migratory stream (RMS), and differentiate into
interneurons. To compare the phenotype of cultured hNT cells to their
transplanted cohorts, hNT cells labeled by the fluorescent dye PKH26 were
cultured for 1 day and stained with cell-type-specific antibodies. Clusters as
well as individual hNT cells were immunoreactive for TuJ1, an antibody that
recognizes neuron-specific class III beta-tubulin. The distribution and phenotype
of the transplanted hNT cells were examined. The majority of transplanted PKH26
labeled hNT cells were found at their site of implantation in the SVZa, while a
small proportion of the transplanted hNT cells was situated in the migratory
pathway leading to the OB and in the subependymal zone and granule cell layer of
the olfactory bulb. Many of the transplanted hNT cells, both within the SVZa and
within the RMS, revealed a neuronal phenotype. Collectively, these results reveal
the capacity of hNT cells to respond, at least partially, to cues that ordinarily
govern the migration of SVZa-derived cells and maintain their neuronal identity.
PMID- 10785442
TI - Neuroprotection by 2-h postischemia administration of two free radical
scavengers, alpha-phenyl-n-tert-butyl-nitrone (PBN) and N-tert-butyl-(2
sulfophenyl)-nitrone (S-PBN), in rats subjected to focal embolic cerebral
ischemia.
AB - Oxygen free radical generation may have important secondary damaging effects
after the onset of cerebral ischemia. Free radical scavengers have been used
successfully in attenuating neuronal damage in the reperfusion period in
transient forebrain ischemia. There are limited data on effectiveness in models
of focal ischemia. Two free radical scavengers, alpha-phenyl-n-tert-butyl-nitrone
(PBN) and N-tert-butyl-(2-sulfophenyl)-nitrone (S-PBN), have been shown to reduce
oxidative-stress-induced neuronal injury. Whereas PBN has been demonstrated to
reduce infarct volume in focal ischemia, neuroprotection has not been evaluated
with S-PBN. The present study was designed to evaluate the neuroprotective effect
of PBN and S-PBN compared to vehicle in a focal embolic middle cerebral artery
(MCA) cerebral ischemia model in rats. Wistar rats were randomly divided into
three groups (n = 10 each group). Animals in the control group received vehicle
and those in the treatment groups were treated with PBN or S-PBN (both 100
mg/kg/day x 3 days, intraperitoneally) starting 2 h after the introduction of an
autologous thrombus into the right-side MCA. The neurological outcome was
observed and compared before and after treatment and between groups. The
percentage of cerebral infarct volume was estimated from 2,3, 5
triphenyltetrazolium chloride stained coronal slices 72 h after the ischemic
insult. Two-hour postischemia administration of PBN or S-PBN significantly
improved neurobehavioral scores at 24 h following MCA embolization (both P <
0.01). The percentage of infarct volume for animals receiving vehicle was 32.8 +/
9.4%. Two-hour delayed administration of PBN and S-PBN achieved a 35.4%
reduction in infarct volume in treatment groups when compared with animals
receiving vehicle (PBN vs control, 21.2 +/- 10.9% vs 32.8 +/- 9.4%; P < 0.05; S
PBN vs control, 21.2 +/- 13.1%, (P < 0.05). These data indicate that free radical
generation may be involved in brain damage in this model and 2-h delayed
postischemia treatment with PBN and S-PBN may have neuroprotective effects in
focal cerebral ischemia. As S-PBN does not normally cross the blood-brain
barrier, the neuroprotection evident in this study may be explained by entry into
the brain via damaged vessels.
PMID- 10785443
TI - Metallothioneins are upregulated in symptomatic mice with astrocyte-targeted
expression of tumor necrosis factor-alpha.
AB - Transgenic mice expressing TNF-alpha under the regulatory control of the GFAP
gene promoter (GFAP-TNFalpha mice) exhibit a unique, late-onset chronic
progressive neurological disorder with meningoencephalomyelitis,
neurodegeneration, and demyelination with paralysis. Here we show that the
metallothionein-I + II (MT-I + II) isoforms were dramatically upregulated in the
brain of symptomatic but not presymptomatic GFAP-TNFalpha mice despite TNF-alpha
expression being present in both cases. In situ hybridization analysis for MT-I
RNA and radioimmunoassay results for MT-I + II protein revealed that the
induction was observed in the cerebellum but not in other brain areas. Increased
MT-I RNA levels occurred in the Purkinje and granular neuronal layers of the
cerebellum but also in the molecular layer. Reactive astrocytes, activated rod
like microglia, and macrophages, but not the infiltrating lymphocytes, were
identified as the cellular sources of the MT-I + II proteins. In situ
hybridization for MT-III RNA revealed a modest increase in the white matter of
the cerebellum, which was confirmed by immunocytochemistry. MT-III
immunoreactivity was present in cells which were mainly round or amoeboid
monocytes/macrophages. The pattern of expression of the different MT isoforms in
the GFAP-TNFalpha mice differed substantially from that described previously in
GFAP-IL6 mice, demonstrating unique effects associated with the expression of
each cytokine. The results suggest that the MT expression in the CNS reflects the
inflammatory response and associated damage rather than a direct role of the TNF
alpha in their regulation and support a major role of these proteins during CNS
injury.
PMID- 10785444
TI - GDNF and NT-4 protect midbrain dopaminergic neurons from toxic damage by iron and
nitric oxide.
AB - Free radical formation is considered to be a major cause of dopaminergic
(DAergic) cell death in the substantia nigra leading to Parkinson's disease (PD).
In this study we employed several radical donors including iron and sodium
nitroprusside to induce toxic effects on DAergic neurons cultured from the
embryonic rat midbrain floor. Overall cell survival was assessed by assaying LDH,
and DAergic neuron survival was monitored by counting tyrosine hydroxylase
positive cells. Our data suggest that the DAergic neuron population is about
fourfold more susceptible to free-radical-mediated damage than the total
population of midbrain neurons. Application of the neurotrophic factors GDNF and
NT-4, for which DAergic neurons have specific receptors, prior to toxin
administration protected these neurons from toxin-mediated death, which, fully or
in part, occurs under the signs of apoptosis. These findings underscore the
importance of GDNF and NT-4 in designing future therapeutical concepts for PD.
PMID- 10785445
TI - Changes in cerebral blood flow and distribution associated with acute increases
in plasma sodium and osmolality of chronic hyponatremic rats.
AB - The cause of the osmotic demyelination syndrome that follows too rapid correction
of chronic hyponatremia (CHN) is unknown. Recently, we reported in CHN rats an
association between blood-brain barrier (BBB) disruption occurring as early as 3
h into correction and subsequent demyelination. Given the changes in brain water
and blood volume which occur during correction of CHN, we hypothesized that the
same correction protocol that causes demyelination might alter cerebral blood
flow (CBF) during correction, thereby possibly contributing to BBB disruption and
demyelination. Ten CHN rats were given hypertonic sodium intraperitoneally and
its effect on CBF was continuously monitored for 3 h by magnetic resonance flow
imaging. Over the subsequent 3 h, plasma sodium rose from 110.8 to 127.6
mEq/liter (P < 0.001) but neither mean arterial blood pressure nor arterial CO(2)
tension changed significantly. By 30 min, CBF increased by 50% in cortical and
subcortical areas (P < 0.001) and remained elevated for the next 60 min. After 2
h, cortical flow was no longer elevated significantly and by 3 h it had returned
to control values. Subcortical flow, however, significantly exceeded control
values throughout the 3 h so that after 2 h the ratio of cortical to subcortical
blood flow had fallen from 1.17 to 0.91 (P < 0.05). Although the mechanism by
which increased plasma sodium and osmolality alters CBF is uncertain, the results
suggest that changes in CBF may be part of a cascade of cerebrovascular
disturbances including endothelial or parenchymal damage, mechanical events,
metabolic disturbances, or cytokine release which eventually lead to BBB
disruption and subsequent demyelination.
PMID- 10785446
TI - IL-6 deficiency leads to reduced metallothionein-I+II expression and increased
oxidative stress in the brain stem after 6-aminonicotinamide treatment.
AB - We examined the effects of interleukin-6 (IL-6) deficiency on brain inflammation
and the accompanying bone marrow (BM) leukopoiesis and spleen immune reaction
after systemic administration of a niacin antagonist, 6-aminonicotinamide (6-AN),
which causes both astroglial degeneration/cell death in brain stem gray matter
areas and BM toxicity. In both normal and genetically IL-6-deficient mice (IL-6
knockout (IL-6KO) mice), the extent of astroglial degeneration/cell death in the
brain stem was similar as determined from disappearance of GFAP immunoreactivity.
In 6-AN-injected normal mice reactive astrocytosis encircled gray matter areas
containing astroglial degeneration/cell death, which were infiltrated by several
macrophages and some T-lymphocytes. Reactive astrocytes and a few macrophages
increased significantly the antioxidants metallothionein-I+II (MT-I+II) and
moderately the MT-III isoform. In 6-AN-injected IL-6KO mice reactive astrocytosis
and recruitment of macrophages and T-lymphocytes were clearly reduced, as were BM
leukopoiesis and spleen immune reaction. Expression of MT-I+II was significantly
reduced while MT-III was increased. Oxidative stress, as determined by measuring
nitrated tyrosine and malondialdehyde, was increased by 6-AN to a greater extent
in IL-6KO mice. The blood-brain barrier to albumin was only disrupted in 6-AN
injected normal mice, which likely is due to the substantial migration of blood
derived inflammatory cells into the CNS. The present results demonstrate that
inflammation in CNS is clearly reduced during IL-6 deficiency and this effect is
likely due to significant inhibition of BM leukopoiesis. We also show that IL-6
deficiency reduces the levels of neuroprotective antioxidants MT-I+II followed by
an increased oxidative stress during CNS inflammation.
PMID- 10785447
TI - Embryonic donor age and dissection influences striatal graft development and
functional integration in a rodent model of Huntington's disease.
AB - The method of embryonic dissection and the age of the donor material remain areas
of controversy in the preparation of striatal tissue for intrastriatal
implantation. This study explores the relationship between these two parameters
with respect to the morphology, function, and physiological integration of the
resultant grafts. Tissue derived from embryos of 14 and 16 days of gestation (CRL
10-11 and 14-15 mm, respectively) was prepared as whole, lateral, and medial
ganglionic eminence suspensions (WGE, LGE, and MGE, respectively). The embryonic
material was implanted into the excitotoxically lesioned striatum of host rats.
Grafts derived from E14 LGE attenuated drug-induced rotational bias whereas
grafts from E14 MGE ameliorated contralateral deficits in paw reaching. Six
months after grafting retrograde tracing of graft projections to the globus
pallidus was performed followed by electrical excitation of cortical afferent
fibers. Grafts derived from E14 WGE had the largest volume of striatum-like
tissue and more striatal neurons compared to LGE from the same donor age. These
results suggest that MGE tissue as well as LGE plays a role in the structural and
functional integration of striatal grafts.
PMID- 10785448
TI - Alzheimer-related tau-pathology in the perforant path target zone and in the
hippocampal stratum oriens and radiatum correlates with onset and degree of
dementia.
AB - Abnormal phosphorylation of the tau-protein is regarded as a crucial step in the
formation of neurofibrillary tangles in the neuronal cell body and neuropil
threads in dendrites. We studied the effects of tau-pathology on the clinical
expression of dementia in 106 autopsy cases in the entorhinal region, the
hippocampal stratum oriens, the stratum radiatum, and the perforant path target
zone. The first cytoskeletal lesions were located in the perikarya and dendrites
of the pre-alpha cells of the transentorhinal and entorhinal region. Next,
abnormally phosphorylated tau-protein (PHF-tau) was found in the neuropil of the
CA1-subiculum region. Thereafter, the stratum radiatum and stratum oriens began
to be involved in PHF-tau pathology in Braak stage II. In the Braak stages IV and
V, the stratum radiatum was completely involved, the stratum oriens increasingly
so. Beginning in Braak stage III, we noted cases having PHF-tau pathology in the
perforant path target zone of the outer molecular layer of the dentate gyrus. The
increase of this pathology with ever greater involvement on the part of the
entorhinohippocampal circuit correlated significantly not only with the Braak
stages and with the neurochemically determined hippocampal content of PHF-tau but
also with the degree of dementia as defined by the clinical dementia rating (CDR)
scale. The affection of the stratum oriens in combination with PHF-tau pathology
in the stratum radiatum and in the outer molecular layer of the dentate gyrus was
encountered almost exclusively in demented individuals (CDR 1-3). These results
indicate that axonal PHF-tau pathology in hippocampal pathways presumably is
critical for the clinical expression of dementia and may constitute an anatomical
substrate of clinically verifiable memory dysfunction in Alzheimer's disease.
PMID- 10785449
TI - Molecular dating of senile plaques in the brains of individuals with Down
syndrome and in aged dogs.
AB - beta-Amyloid (Abeta) is a constituent of senile plaques found with increasing age
in individuals with Down syndrome (DS) and in the canine model of aging. Sections
of DS and dog brain were immunostained using an affinity-purified polyclonal
antibody for a posttranslationally modified Abeta with a racemized aspartate at
position 7 (d7C16). The immunostaining characteristics of d7C16 Abeta in DS and
dog brain indicate that it is present in all plaque subtypes, including the
thioflavin-S-negative diffuse plaques that develop with age in dogs. The youngest
DS case exhibited weak immunolabeling for d7C16 but the extent of d7C16-positive
plaques increased with age. In addition, d7C16-positive plaques were initially
found in clusters in the superficial layers of the frontal and entorhinal cortex
but, with advancing age, increasing numbers appeared in deeper layers, suggesting
a progression of Abeta deposition from superficial to deeper cortical layers.
Ultrastructural studies in DS brain were confirmed using perfused dog brain and
provided consistent results; thioflavin-S-negative diffuse plaques consist of
fibrillar Abeta and racemized Abeta is associated with thicker and more highly
interwoven fibrils than nonracemized Abeta. The use of antibodies to modified
forms of the Abeta protein should provide insight into the progression of plaque
pathology in DS and Alzheimer's disease brain.
PMID- 10785450
TI - In situ produced 7-chlorokynurenate provides protection against quinolinate- and
malonate-induced neurotoxicity in the rat striatum.
AB - Excitotoxic mechanisms may play a critical role in the pathophysiology of several
neurological and psychiatric diseases. Excitatory amino acid receptor antagonists
are therefore of great therapeutic interest, but untoward side effects often
prevent their clinical use. Targeting the glycine coagonist site of the (NMDA)
receptor may bypass these shortcomings. The present study was designed to
evaluate the neuroprotective characteristics of l-4-chlorokynurenine (4-Cl-KYN),
a synthetic compound which is enzymatically converted to the selective
glycine/NMDA receptor antagonist 7-chlorokynurenate (7-Cl-KYNA). Using slow (2 h)
intrastriatal infusions of the excitotoxins quinolinate (QUIN; 120 nmol) or
malonate (6.8 micromol) as the experimental paradigm, the neuroprotective potency
of 4-Cl-KYN was first compared with that of exogenous 7-Cl-KYNA, using glutamate
decarboxylase activity as a lesion marker. One hundred and thirty-five nanomoles
of the prodrug 4-Cl-KYN or 27 nmol 7-Cl-KYNA, the former used in a pre- and
cotreatment regimen, were required to block QUIN or, less efficiently, malonate
toxicity. In separate animals, the metabolic fate of this neuroprotective dose of
4-Cl-KYN was examined in vivo. In control striata, the treatment gave rise to 170
+/- 25 pmol 7-Cl-KYNA/mg protein, approximately six times less than an infusion
of 27 nmol exogenous 7-Cl-KYNA, indicating greatly superior efficacy of the
focally produced antagonist. Notably, the conversion of 4-Cl-KYN to 7-Cl-KYNA
increased by 82% in the presence of QUIN. 4-Cl-KYN was also metabolized to 4
chloro-3-hydroxyanthranilate, an established, powerful inhibitor of QUIN
synthesis. This unique pharmacological profile and the fact that the prodrug,
unlike 7-Cl-KYNA, readily penetrates the blood-brain barrier suggest that 4-Cl
KYN may be exceptionally useful as an anti-excitotoxic agent.
PMID- 10785451
TI - Hydrocephalus in the H-Tx rat: a monogenic disease?
AB - The H-Tx rat is a genetic model of hydrocephalus for which thereis a poor
understanding of the mode of inheritance. Previous studies suggested a
polygenicmode of inheritance but the breeding data to supportthis hypothesis have
not been reported. In an attempt to clarify the hereditary mode we have analyzed
the data from eight generations of H-Tx rats and four generations of cross
matings between H-Tx rats and Sprague-Dawley (SD) rats. In the H-Tx rat colony
113 of 129 random brother-sister matings (87.60%) produced hydrocephalic
offspring, with males and females being equally affected. The overall incidence
varied greatly with an average of 30. 35%. In matings with more than three
litters, all mating pairs yielded hydrocephalic pups. In cross-matings both
hydrocephalic and normal H-Tx rats were mated with normal SD rats. No
hydrocephalus was observed in the first generation of 124 pups (F1). Subsequent
brother-sister matings of F1 animals generated hydrocephalic pups in the F2
generation with a lower incidence (4.67% in hydrocephalic HTx/SD matings and
5.11% in normal HTx/SD matings, respectively) than in the H-Tx rat colony
(30.35%). Back-cross-matings between F2 rats and normal H-Tx rats yielded an
incidence of hydrocephalus higher than that of the cross-matings but lower than
that of the H-Tx colony. These data strongly suggest that the H-Tx rat is a
homozygous carrier of an autosomal recessive hydrocephalus gene with incomplete
penetrance. Furthermore, the data clearly rule out sex-linked and polygenic modes
of inheritance and provide further insight with respect to genetic inheritance of
hydrocephalus.
PMID- 10785452
TI - Coordination of prehensile forces during precision grip in Huntington's disease.
AB - The present study examined the coordination of prehensile forces during precision
grip in subjects with Huntington's disease (HD). Fingertip forces were measured
in 12 subjects with HD and 12 age-matched controls during the lifting of an
instrumented object whose weight and surface texture were varied. The results
indicate that subjects with HD have impaired initiation and delayed transitions
between movement sequences and produce excessive and variable forces. However,
subjects with HD demonstrated anticipatory scaling of force development based on
the object's expected physical properties (planning) and adjustment of the force
to the object's actual physical properties (sensorimotor integration). The
observed findings generally were unrelated to the overall disease severity.
However, the variability in forces was correlated with functional capacity and
motor performance suggesting that variability is a key feature of the motor
deficit. These results provide insights into the impaired hand function observed
in individuals with HD.
PMID- 10785453
TI - Immunological myelin disruption does not alter expression of regeneration
associated genes in intact or axotomized rubrospinal neurons.
AB - The inability of axotomized neurons to regenerate within the CNS has been
partially attributed to a number of inhibitory factors associated with CNS myelin
that are extrinsic to the severed neurons. However, some neurons are capable of
limited regeneration after injury and this ability has been shown to correlate
with the expression of certain regeneration-associated genes (RAGs) intrinsic to
injured neurons. It has therefore been postulated that neutralization of
inhibitory factors, as well as the induction of an appropriate neuronal cell body
response, would facilitate improved regrowth of injured CNS axons. In previous
studies we have shown that immunological removal of myelin from the spinal cord
facilitates axonal regeneration by rubrospinal neurons, as indicated by
retrograde transport of a fluorescent dye placed distal to the site of injury.
Here, we investigated whether the immunological focal removal of spinal cord
myelin, following a thoracic spinal cord injury, concomitantly stimulated an
increase in the expression of RAGs in rubrospinal neurons. In situ hybridization
for Talpha-1 tubulin and GAP-43 at days 7, 14, and 21 revealed no significant
increase in gene expression in rubrospinal neurons following immunological
demyelination. The ability of various neuronal populations to sprout or slowly
regrow without expressing the previously characterized cell body response is
reviewed. We conclude that the recently demonstrated regeneration of rubrospinal
tract, after immunologically directed spinal cord demyelination, is the result of
either axonal sprouting or slow axonal regrowth without the increased expression
of RAGs characteristic for fast axon regeneration.
PMID- 10785454
TI - Effects of aluminum exposure on glutamate metabolism: a possible explanation for
its toxicity.
AB - The effects of aluminum (Al) exposure on glutamate metabolism were investigated
to study the mechanism of Al toxicity in rat brain. In astrocytes, the glutamate
glutamine pathway prevents the accumulation of the excitatory neurotransmitter
glutamate, recognized as a neuronal excitotoxin when present in excess in the
extracellular space. Changes in the level of l-aspartate, l-glutamate, and its
metabolite l-glutamine were investigated in various regions of rat brains
following intraperitoneal injection of aluminium gluconate for 2 months. The
changes observed were area- and amino-acid-specific. An increase in glutamine,
but not in l-glutamate or l-aspartate, was noted in the hippocampus and neocortex
of Al-treated rats. This increase in vivo was consistent with observations in
vitro. Exposure of cultured astrocytes to Al chloride (200, 400, and 800 microM)
specifically increased glutamine synthetase activity for the three concentrations
tested. In parallel with this increase, a higher rate of disappearance of
glutamate from culture medium was observed during the first 10 min of incubation
for the three concentrations tested, as well as an accumulation of glutamine in
the cellular extract after 30 min. These observations indicate that the astrocyte
population is a potential target for Al toxic action that could mediate the
pathogenesis of this metal.
PMID- 10785455
TI - Enhancement of acute phase and inhibition of chronic phase of experimental
autoimmune neuritis in Lewis rats by intranasal administration of recombinant
mouse interleukin 17: potential immunoregulatory role.
AB - Experimental autoimmune neuritis (EAN) is a CD4(+) T-cell-mediated demyelinating
disease of the peripheral nervous system (PNS). We examined the effect of
recombinant mouse interleukin 17 (rmIL-17) on chronic EAN induced in Lewis rats
by inoculation of P2 57-81 peptide in Freund's complete adjuvant. Animals were
treated nasally for 6 days with either 0.1 or 0.9 microg/rat/day rmIL-17 from the
onset of neurological signs, i.e., days 9 to 14 postimmunization (p.i.).
Prolonged follow-up demonstrated a chronic course in control and rmIL-17-treated
rats. Treated rats had more severe disease initially (days 18-36 p.i.) with a
stronger enhancing effect observed with the higher rmIL-17 dose. At day 19 rmIL
17-treated rats showed increased infiltration of inflammatory cells into the
sciatic nerve, more severe demyelination, augmented proliferation of regional
lymph node cells, and increased serum levels of tumor necrosis factor-alpha.
After the initial phase of disease enhancement the IL-17-treated EAN rats
improved gradually and ultimately recovered completely, whereas the control EAN
rats remained affected until the end of the observation (day 120 p.i.). The lower
dose of rmIL-17 induced an earlier recovery from clinical deficits than the
higher one. The results indicate that IL-17 plays an immunoregulatory role in
chronic EAN which could have implications for immunomodulatory treatments of
chronic autoimmune disease of the PNS.
PMID- 10785456
TI - Ultrastructural localization of monoclonal antiphospholipid antibody binding to
rat brain.
AB - Antiphospholipid antibodies (aPL), in the presence or absence of systemic lupus
erythematosus, are associated with a number of neurologic complications. However,
the role aPL play in pathology is unclear. A thrombotic etiology seems likely for
many associated disorders, but not for others. Here we describe aPL-reactive
sites in the central nervous system (CNS). Previously, using light microscopy, we
showed direct binding of two monoclonal phosphatidylserine-reactive antibodies
(aPS) to ependyma and myelin of fixed cat brain. In this study we determined the
ultrastructural localization of their binding sites in rat CNS using immunogold
electron microscopy techniques. Both monoclonal antibodies reacted strongly with
myelin, preferentially with the major dense line formed by the cytoplasmic
apposition of the oligodendrocyte plasma membrane. Both monoclonal antibodies
also reacted with an antigen that appears associated with the axoneme in cilia of
ependymal and choroid plexus epithelium. One monoclonal aPS also showed some
reactivity with brain vascular endothelium and reacted slightly with
mitochondria, while the other aPS did not react with these structures. While the
etiology of aPL-associated neurologic disorders remains unclear, our data suggest
possible target sites within the CNS with which aPL can react.
PMID- 10785457
TI - An analysis of atrophy in the medial mammillary nucleus following hippocampal and
fornix lesions in humans and nonhuman primates.
AB - Lesions of the hippocampal formation or transections of the fornix are followed
by shrinkage of the medial mammillary nucleus (MMN). We determined whether the
shrinkage of this nucleus was due to loss and/or shrinkage of neurons in addition
to the loss of neuropil. We examined the MMN in a patient (KB) with an infarct
that led to marked atrophy of the left hippocampus and subiculum, leaving the
right MMN intact. Unbiased, stereological measurement techniques were used to
compare the total cell number and individual neuronal cross-sectional areas in
both left and right MMN in this patient and in two control human brains. We also
analyzed the MMN in four macaque monkeys that underwent experimental unilateral
transections of the fornix. The volume of the MMN on the lesioned side in KB was
55% of the unlesioned side (2.8 mm(3) vs 5.1 mm(3)); the MMN in the monkey cases
were reduced to 47-58% of the volume of the nonlesioned side. Neurons in the
deafferented MMN of KB and of the monkey subjects were decreased in cross
sectional area (16-20%, P < 0.0001). There was a trend toward decreased cell
numbers (11-15%) on the lesioned side in all cases. We have estimated that the
loss in cell number and shrinkage of remaining cells contribute negligibly to the
45% reduction in MMN volume. Therefore, the loss of neuropil (dendrites and
afferent and efferent axons) appears to be the major contributor to the change in
MMN volume.
PMID- 10785458
TI - 125I-CGP 64213 binding to GABA(B) receptors in the brain of monkeys: effect of
MPTP and dopaminomimetic treatments.
AB - Much evidence indicates that abnormal GABA neurotransmission may be implicated in
the pathophysiology of Parkinson's disease (PD) and dopaminomimetic-induced
dyskinesias (DID). In this study, autoradiography using (125)I-CGP 64213 was
performed to investigate GABA(B) receptor density in the brain of control monkeys
as well as monkeys with MPTP-induced nigrostriatal depletion. Three MPTP monkeys
received pulsatile administrations of the D1 dopamine (DA) receptor agonist (SKF
82958) whereas a long-acting D2 DA receptor agonist (cabergoline) was given to
another three animals. SKF 82958 treatment relieved parkinsonian symptoms but two
of three animals developed DID. Cabergoline induced a comparable motor benefit
effect without persistent DID. (125)I-CGP 64213 binding to GABA(B) receptors was
heterogeneous throughout the brain with the highest levels in the medial habenula
of the thalamus. MPTP induced a decrease (-40%) of (125)I-CGP 64213 binding to
GABA(B) receptors in the substantia nigra pars compacta (SNpc) and an increase
(+29%) in the internal segment of the globus pallidus (GPi). This increase in the
GPi was not affected by SKF 82958 but partly reversed by cabergoline. No change
was seen in the striatum, the thalamus, the external segment of the globus
pallidus, and the substantia nigra pars reticulata following MPTP and
dopaminomimetic treatments. The changes of GABA(B) receptors observed in the SNpc
and in the GPi suggest that alteration of GABA(B) receptors may play a role in
the pathophysiology of PD and DID.
PMID- 10785459
TI - Persistent neuroprotection with prolonged postischemic hypothermia in adult rats
subjected to transient middle cerebral artery occlusion.
AB - Postischemic hypothermia provides long-lasting neuroprotection against global
cerebral ischemia in adult rats and gerbils. Studies indicate that hypothermia
must be prolonged (e.g., 24 h) to indefatigably salvage hippocampal CA1 neurons.
Delayed hypothermia also reduces focal ischemic injury. However, no study has
examined long-term outcome following postischemic hypothermia in adult animals.
Furthermore, most studies examined only brief hypothermia (e.g., 3 h). Since
previous studies may have overestimated long-term benefit and have likely used
suboptimal durations of hypothermia, we examined whether prolonged cooling would
attenuate infarction at a 2-month survival time following middle cerebral artery
occlusion (MCAo) in rats. Adult male Wistar rats were implanted with telemetry
brain temperature probes and later subjected to 30 min of normothermic MCAo
(contralateral to side of probe placement) or sham operation. Ischemia was
produced by the insertion of an intraluminal suture combined with systemic
hypotension (60 mm Hg). Sham rats and one ischemic group controlled their own
postischemic temperature while another ischemic group was cooled to 34 degrees C
for 48 h starting at 30 min following the onset of reperfusion. The infarct area
was quantified after a 2-month survival time. Normothermic MCAo resulted in
almost complete striatal destruction (91% loss +/- 12 SD) with extensive cortical
damage (36% +/- 16 SD). Delayed hypothermia treatment significantly reduced
cortical injury to 10% +/- 10 SD (P < 0.001) while striatal injury was marginally
reduced to 79% loss +/- 17 SD (P < 0.05). Delayed hypothermia of only 34 degrees
C provided long-lasting cortical and striatal protection in adult rats subjected
to a severe MCAo insult. These results strongly support the clinical assessment
of hypothermia in acute stroke.
PMID- 10785460
TI - Degeneration of cone photoreceptors induced by expression of the Mas1
protooncogene.
AB - Although transgenic expression of oncogenes typically leads to tumorigenesis,
oncogene expression directed to the rod photoreceptors leads to cell death
without tumor formation. To evaluate the cellular and functional changes induced
in cone photoreceptors by an oncogene, the Mas1 protooncogene was targeted to the
cones of transgenic mice by the human red/green opsin promoter. Mas1 was chosen
because of its exclusive expression in the nervous system and its homology to
opsin. The overall histologic appearance of the transgenic retina was normal and
retinal tumors were never observed. While rod-mediated electroretinograms were
normal in all respects, cone-mediated responses were diminished in direct
relationship to the level of transgene expression as determined by Northern blot
analysis. Responses of UV- and green-sensitive cones were reduced equivalently,
and Northern analysis and immunocytochemistry indicated that cone photoreceptor
densities were markedly diminished throughout transgenic retinas. These results
indicate that oncogene expression in cones induces cell death without tumor
formation and support the possibility that aberrant oncogene expression may
underlie some forms of hereditary retinal diseases. The Mas1 transgenic mice may
be useful in understanding the cone photoreceptor degeneration that occurs in
cone dystrophies and age-related macular degeneration and in evaluating potential
therapies for these disorders.
PMID- 10785461
TI - Localization of transforming growth factor-beta1 and receptor mRNA after
experimental spinal cord injury.
AB - Transforming growth factor-beta1 (TGFbeta1) is a cytokine/growth factor found
within the pathological central nervous system. TGFbeta1 has been shown to
inhibit the release of cytotoxic molecules from microglia and macrophages,
decrease astrocyte proliferation, and promote neuron survival. Because of the
relevance of these actions to spinal cord injury, we examined TGFbeta1 and its
receptors betaRI and betaRII mRNA levels and localization within the contused rat
spinal cord using in situ hybridization. At the lesion site, TGFbeta1 mRNA peaked
at 7 days postinjury and declined thereafter. Temporal and spatial localization
of the betaRI and betaRII receptor mRNA closely mimicked that for TGFbeta1 in the
epicenter. TGFbeta1, betaRI, and betaRII mRNAs also were elevated rostral and
caudal to the injury, especially in regions known to contain activated microglia
and degenerating axon profiles. Immunohistochemical staining of nearby sections
confirmed that the highest levels of TGFbeta1 and receptor mRNA corresponded to
regions filled with activated microglia and macrophages. The similar expression
pattern of TGFbeta1, betaRI, and betaRII mRNA within the injured spinal cord
suggests a local site of action. Since TGFbeta1 can act as an immunosuppressant
as well as a stimulant for growth factors and neurite sprouting, it likely plays
an important role, both temporally and spatially, in orchestrating postinjury
events within the spinal cord.
PMID- 10785462
TI - Development of a mouse model of neuropathic pain following photochemically
induced ischemia in the sciatic nerve.
AB - A mouse model of neuropathic pain was developed by a photochemically induced
ischemic nerve injury in normal male C57/BL6 mice. The ischemia was induced by
unilateral irradiation of the sciatic nerve with an argon ion laser after
intravenous administration of a photosensitizing dye, erythrosin B. The nerve
injury resulted in a significant decrease in withdrawal threshold of the hindpaws
to mechanical stimulation with von Frey hairs, as well as increased
responsiveness to cold and heat stimulation. The mice, however, did not exhibit
overt spontaneous pain-like behaviors. The evoked pain-related behaviors were
observed bilaterally, although the ipsilateral changes were greater than on the
contralateral side. The extent and time course of the behavioral changes were
related to the duration of laser irradiation, with 1-min exposure producing the
most consistent effect. Morphological examination at the light microscopic level
revealed partial demyelination and axonal degeneration of the large myelinated
fibers at the epicenter of the lesion 1 week postirradiation. The extent of the
damage was correlated with the duration of irradiation. Injury and loss of
unmyelinated fibers were also observed at the electronmicroscopic level. We
conclude that an intravascular photochemical reaction leading to ischemia results
in graded damage to the sciatic nerve in mice. Moreover, the nerve injury is
associated with the development of abnormal pain-related behaviors. Both the
behavioral and the morphological changes are correlated with the duration of
irradiation. These results establish a mouse model of partial nerve injury with
neuropathic pain-like behaviors which may be useful in studies using genetically
modified mice.
PMID- 10785463
TI - Antiparkinsonian actions of CP-101,606, an antagonist of NR2B subunit-containing
N-methyl-d-aspartate receptors.
AB - In the setting of nigrostriatal dopamine depletion, glutamatergic pathways to the
striatum and basal ganglia output nuclei become overactive. Systemically
administered glutamate receptor antagonists may have direct antiparkinsonian
actions in rodents, but there is little evidence for this in primates. Glutamate
antagonists may also potentiate conventional dopaminergic therapies; however,
there is concern that broad spectrum, nonselective antagonists may have unwanted
side-effects. Because subunit-selective antagonists may avoid these liabilities,
we have examined the antiparkinsonian effects of a selective antagonist of the
NR2B subunit of the NMDA receptor. In rats, CP-101,606 decreased haloperidol
induced catalepsy with an ED(50) of about 0.5 mg/kg. In MPTP-treated monkeys, CP
101,606 (1 mg/kg) reduced parkinsonian motor symptoms by 20%. At a dose of 0.05
mg/kg, CP-101,606 markedly potentiated the effect of a submaximal dose of
levodopa, reducing motor symptoms by about 50% compared to vehicle and by about
30% compared to levodopa alone. No side-effects were apparent at any dose of CP
101,606. We conclude that CP-101,606 has direct antiparkinsonian actions in both
rodents and monkeys and it synergistically potentiates levodopa in MPTP-treated
monkeys. Clinical evaluation of selective NR2B antagonists may be warranted in
Parkinson's disease.
PMID- 10785464
TI - Brain trauma in aged transgenic mice induces regression of established abeta
deposits.
AB - Traumatic brain injury (TBI) increases susceptibility to Alzheimer's disease
(AD), but it is not known if TBI affects the progression of AD. To address this
question, we studied the neuropathological consequences of TBI in transgenic (TG)
mice with a mutant human Abeta precursor protein (APP) mini-gene driven by a
platelet-derived (PD) growth factor promoter resulting in overexpression of
mutant APP (V717F), elevated brain Abeta levels, and AD-like amyloidosis. Since
brain Abeta deposits first appear in 6-month-old TG (PDAPP) mice and accumulate
with age, 2-year-old PDAPP and wild-type (WT) mice were subjected to controlled
cortical impact (CCI) TBI or sham treatment. At 1, 9, and 16 weeks after TBI,
neuron loss, gliosis, and atrophy were most prominent near the CCI site in PDAPP
and WT mice. However, there also was a remarkable regression in the Abeta amyloid
plaque burden in the hippocampus ipsilateral to TBI compared to the contralateral
hippocampus of the PDAPP mice by 16 weeks postinjury. Thus, these data suggest
that previously accumulated Abeta plaques resulting from progressive amyloidosis
in the AD brain also may be reversible.
PMID- 10785465
TI - Neurotransmitter-mediated control of neuronal firing in the red nucleus of the
rat: reciprocal modulation between noradrenaline and GABA.
AB - The electrical activity of neurons from the red nucleus, a mesencephalic
structure involved in motor control, is under the influence of several
neurotransmitters released from afferent fibers and/or from local interneurons.
We have investigated the combined effects of gamma-aminobutyric acid (GABA) and
noradrenaline (NA), both present at high levels in the red nucleus, on the firing
activity of single rubral neurons recorded extracellularly in vivo on
anesthetized adult rats. NA inhibited the firing activity of a large part of
rubral neurons and induced excitatory or biphasic inhibitory/excitatory effects
in a smaller group of cells. Neuronal firing was also inhibited by GABA in all
the cells studied. When the effect of GABA was tested during continuous
applications of NA, the magnitude of GABA response was modified in 58% of the
cells: the effect of GABA was potentiated by NA in half of the responding neurons
and was decreased in the remaining half. NA-induced potentiation of GABA response
was mimicked by the alpha(2)-adrenoceptor agonist clonidine and was abolished by
the alpha(2)-adrenoceptor antagonist yohimbine. On the other side, the decrease
of GABA response was reproduced by the beta-adrenoceptor agonist isoprenaline and
was blocked by timolol, an antagonist of beta-adrenoceptors. Neuronal firing
activity was reduced by nipecotic acid, an inhibitor of GABA reuptake mechanism,
and was instead increased during application of the GABA(A) receptor antagonist
bicuculline, suggesting that rubral neurons in vivo were under tonic control by
endogenous GABA. Both the inhibitory and the excitatory effects of NA were
reduced in the presence of nipecotic acid and were instead potentiated during
application of bicuculline, suggesting that NA responses were modified by
endogenous GABA. Taken together, our results indicate a reciprocal modulation
between the effects of GABA and NA on neuronal firing activity in the red nucleus
of the rat: GABA depresses the responsiveness of rubral neurons to NA, whereas NA
is able either to potentiate or to decrease the effects of GABA by activation of
alpha(2)- and beta-adrenoceptors, respectively. The functional significance of
such interaction, as well as the possible implication in diseases affecting motor
control, will be discussed.
PMID- 10785466
TI - Modulation of audiogenic seizures by histamine and adenosine receptors in the
inferior colliculus.
AB - Susceptibility to behaviorally similar audiogenic seizures (AGS) occurs
genetically and is inducible during ethanol withdrawal (ETX). Comparisons between
AGS mechanisms of genetically epilepsy-prone rats (GEPR-9s) and ethanol-withdrawn
rats (ETX-Rs) are yielding information about general pathophysiological
mechanisms of epileptogenesis. The inferior colliculus (IC) is the AGS initiation
site. Excitatory amino acid (EAA) abnormalities in the IC are implicated in AGS,
and histamine and adenosine receptor activation each reduce EAA release and
inhibit several seizure types. Previous studies indicate that focal infusion of
an adenosine receptor agonist into the IC blocked AGS in GEPR-9s, but the effects
of adenosine receptor activation in the IC on AGS in ETX-Rs are unknown. The
effects of histamine receptor activation on either form of AGS are also
unexamined. The present study evaluated effects of histamine or a nonselective
adenosine A(1) agonist, 2-chloroadenosine, on AGS by focal microinjection into
the IC. Ethanol dependence and AGS susceptibility were induced in normal rats by
intragastric ethanol. Histamine (40 or 60 nmol/side) significantly reduced AGS in
GEPR-9s, but histamine in doses up to 120 nmol/side did not affect AGS in ETX-Rs.
2-Chloroadenosine (5 or 10 nmol/side) did not affect AGS in ETX-Rs, despite the
effectiveness of lower doses of this agent in GEPR-9s reported previously. Thus,
histamine and adenosine receptors in the IC modulate AGS of GEPR-9s, but do not
modulate ETX-induced AGS. The reasons for this difference may involve the
chronicity of AGS susceptibility in GEPR-9s, which may lead to more extensive
neuromodulation as compensatory mechanisms to limit the seizures compared to the
acute AGS of ETX-Rs.
PMID- 10785467
TI - NMDAR1 receptor proteins and mossy fibers in the fascia dentata during rat
kainate hippocampal epileptogenesis.
AB - We examined the time course of NMDAR1 (NR1) immunoreactivity (IR) in the rat
inner molecular layer of the dentate gyrus following unilateral intrahippocampal
(hilar) kainic acid (KA) lesions and compared them to progressive aberrant mossy
fiber (MF) sprouting into the inner molecular layer (IML). The results
demonstrated that NR1 receptors in the IML of the KA side were decreased as early
as 3 days after KA-induced denervation, then significantly increased at
postinjection day (PID) 7. The densities of NR1 IR in the IML continued to
increase up to 5 months. By comparison, MF sprouting did not occur significantly
in the IML until PID 17, 10 days after NR1 IR was significantly increased.
Recurrent MF-IML neoinnervation significantly increased on days 17, 60, and 150.
This progressive MF innervation was significantly correlated with NR1 increases.
These results suggest that NR1 receptors were decreased soon after KA-induced
deafferentation of granule cell dendrites in the IML; however, they were replaced
by new NR1 receptors at increased densities in the granule cell dendrites, which
may have released neurotrophic factors to stimulate growth cones of MFs to
reinnervate the IML. The progressive increases of NR1 and MFs in the IML suggest
that such neosynaptogenesis would contribute monosynaptic recurrent excitatory
mechanisms for focal hippocampal hyperexcitability and seizure onsets.
PMID- 10785468
TI - Preoperative prediction of optimal resectability in advanced ovarian cancer using
CA-125.
PMID- 10785469
TI - The ability of preoperative serum CA-125 to predict optimal primary tumor
cytoreduction in stage III epithelial ovarian carcinoma.
AB - PURPOSE: The aim of this study was to determine the ability of preoperative serum
CA-125 to predict optimal primary tumor cytoreduction in patients with Stage III
epithelial ovarian carcinoma. METHODS: We performed a retrospective chart review
of 100 consecutive patients with Stage III ovarian carcinoma who had a serum CA
125 drawn prior to primary cytoreductive surgery. We used a receiver operating
characteristic curve to determine the CA-125 level with the maximal prognostic
power in predicting optimal versus suboptimal cytoreduction. RESULTS: The median
CA-125 level for the 100 patients was 819 U/ml (range 5.6-26,200 U/ml). Optimal
cytoreduction (diameter of largest residual tumor nodule < or =1 cm) was obtained
in 45 cases (45%). The probability of performing optimal cytoreduction decreased
with increasing CA-125 levels. A preoperative CA-125 level of 500 U/ml was
identified as the value with the most predictive power. Optimal cytoreduction was
achieved in 33 of the 45 cases (73%) with a CA-125 less than 500 U/ml compared to
only 12 of the 55 cases (22%) with a CA-125 greater than 500 U/ml. Using a
threshold level of 500 U/ml, the preoperative serum CA-125 level was able to
predict optimal versus suboptimal cytoreduction with a sensitivity of 78%,
specificity of 73%, positive predictive value of 78%, and negative predictive
value of 73%. CONCLUSION: The probability of performing optimal cytoreduction in
patients with Stage III ovarian carcinoma and a preoperative CA-125 greater than
500 U/ml was approximately one in five. These patients may be candidates for
initial laparoscopic evaluation to obtain a confirmatory tissue diagnosis and to
determine resectability.
PMID- 10785470
TI - Assessment of inhibin and p53 in granulosa cell tumors of the ovary.
AB - OBJECTIVE: The goal of this work was to determine the cellular content of inhibin
and p53 in granulosa cell tumors (GCTs). METHODS: Clinical records of 47 patients
(mean age, 54 years; range, 20-85 years) presenting with GCT surgically managed
at our institution were abstracted. International Federation of Gynecology stage
I was assigned in 39 patients, stage II in 2, and stage III in 6. Concomitant
endometrial carcinoma was identified in 6 patients. Mean follow-up was 13.6 years
(range, 1 day to 37.6 years). Sections from paraffin-embedded tissue blocks were
analyzed immunohistochemically for expression of tissue inhibin and p53 levels.
Inhibin expression was graded by intensity and reactivity, and p53, by its
presence or absence. RESULTS: The tumors of 27 patients (57%) stained strongly
for inhibin intensity and showed >60% reactivity. Decreased intensity and
reactivity of inhibin expression were associated with advanced-stage disease (P =
0.05 and P < 0.01, respectively, by Fisher exact test). Expression of p53 was
detected in tumors from 27 patients (57%), and immunoreactivity was associated
with compromised progression-free survival (P = 0.016, log-rank test). However,
the association between p53 immunoreactivity and disease stage was not
significant. Absence of p53 expression was significantly associated with
concurrent endometrial carcinoma (P = 0.022), suggesting more molecularly intact
tumors that retain functional activity. CONCLUSIONS: Although the majority of
GCTs show strong expression of inhibin with regard to intensity and reactivity,
weak expression is associated with advanced disease but not with decreased
progression-free survival. By contrast, expression of p53 is not significantly
associated with stage, but increased expression is associated with decreased
disease-free survival. Absence of p53 expression appears to be associated with
concurrent endometrial carcinoma.
PMID- 10785472
TI - The diagnostic value of power Doppler measurements in the endometrium of women
with postmenopausal bleeding.
AB - OBJECTIVE: The objective was to evaluate the accuracy of blood flow measurements
by power Doppler in endometrial vessels in women with postmenopausal bleeding
(PMB). METHODS: Sixty consecutive patients with PMB participated in the study.
Endometrial thickness and power Doppler measurements of small vessels in the
endometrium and subendometrial tissue were performed prior to dilatation and
curettage. Correlation between Doppler indices, endometrial thickness (by
transvaginal sonography), and histopathologic examination was performed. A
Student t test was used for statistical analysis with P < 0.05 as the level of
significance. RESULTS: Fourteen positive cases were found: 11 endometrial
cancers, 1 sarcoma, 1 simple hyperplasia, and 1 complex hyperplasia with atypia.
Measurements of endometrial thickness using a cutoff point of 5 mm revealed a
sensitivity of 78% and specificity of 45.6% (P > 0.05, NS) for detecting
endometrial pathology. Power Doppler measurements (pulsatility index cutoff point
= 1.0) revealed a sensitivity of 85. 7% and specificity of 89% (P = 0.001) for
detecting endometrial pathology. CONCLUSIONS: The noninvasive methods for
endometrial evaluation are not sensitive enough to exclude endometrial pathology.
When invasive methods could not be performed, the combination of transvaginal
sonography and power Doppler imaging provided the best results. When both
modalities are negative, the probability of cancer is less than 5%.
PMID- 10785471
TI - p21 (WAF1/CIP1) protein expression is associated with prolonged survival but not
with p53 expression in epithelial ovarian carcinoma.
AB - OBJECTIVE: The objective of this study was to clarify the influence of p21
protein expression in ovarian cancer. p21 (WAF1 [wild-type p53 activated fragment
1]/CIP1) is a universal cyclin-dependent kinase inhibitor and can be induced as a
downstream effector of the p53 tumor suppressor gene. METHODS: The expression of
p21 was evaluated by immunohistochemical analysis with the monoclonal antibody
WAF1 (Oncogene Science) on 106 formalin-fixed, paraffin-embedded tissue samples
of epithelial ovarian cancer. RESULTS: p21 was expressed in 65 (61%) of all
cases. p21 expression was associated with early stage in FIGO classification
(FIGO I and II, P = 0.003) and no tumor residues after primary tumor resection (P
= 0.018). Immunohistochemical staining results were judged as negative if no
tumor nuclei were stained, as weak positive if 1-49% were stained, and as strong
positive if over 50% of nuclei were stained. Clinical follow-up showed a better
overall survival for cases with strong p21 expression (79 months) versus 40
months for weak expression and 30 months for no expression (P = 0.033).
Previously determined p53 expression of this cohort was compared with p21 status.
p53 overexpression was observed in 49 cases (48%) and showed no association with
p21 expression. CONCLUSION: No correlation was found between p21 and p53
expression. p21 expression is a significant prognostic marker for improved
survival in ovarian cancer and is associated with early FIGO stage and zero tumor
residues after primary tumor resection.
PMID- 10785473
TI - Management of aggressive histologic variants of endometrial carcinoma at the Tom
Baker Cancer Centre between 1984 and 1994.
AB - OBJECTIVE: The aim of this study was to determine the patient characteristics and
outcome of patients with aggressive histologic variants (AV) of endometrial
carcinoma, including uterine papillary serous carcinoma (UPSC), uterine clear
cell carcinoma (UCCC), and mixed type. METHODS AND MATERIALS: All cases with AV
histological type of endometrial carcinoma from January 1984 to December 1994 at
the Tom Baker Cancer Centre were identified using the Alberta Cancer Registry.
Relevant data from the charts of these patients were entered into a study
database (Microsoft Excel) and analyzed for presentation, demography, treatment
parameters, and outcome of treatment. All pathology was reviewed at the time of
diagnosis. Statistical analysis was performed using the S-plus statistics
computer program. Univariate and multivariate analyses were used to assess
independent prognostic factors using the Cox proportional hazards model. RESULTS:
A total of 103 patients with AV histological type were identified and analyzed;
there were 61, 31, and 11 cases of UPSC, CCC, and mixed tumors, respectively.
Sixty-three patients had Stage I, 11 had Stage II, 15 had Stage III, and 14 had
Stage IV disease. The median age of patients was 67 years with a range of 36 to
86 years. Median follow-up was 60 months with a range of 36 to 156 months. The
Cox proportional hazards model showed that lymphvascular space invasion and stage
are the two independent prognostic factors affecting recurrence and survival.
Forty six percent of all cases underwent surgery alone, 39% underwent treatment
which included pelvic RT, and 17% underwent treatment which included
chemotherapy. Pelvic recurrence was reduced significantly by radiotherapy in
Stages I, II, and III (19% recurrence with no RT vs 7% recurrence with RT, P <
0.005). Chemotherapy improved overall survival, but made little difference in
distant relapse rates. CONCLUSIONS: Stage Ia cases treated by surgery alone have
a low risk of relapse and need not be offered adjuvant systemic therapy or pelvic
radiation. Patients with Ib, Ic, II, and III have significantly lower pelvic
failure rates if treated with pelvic radiation, but still have a high distant
failure rate. Systemic therapy did not significantly improve distant relapse-free
survival, but did extend overall survival. Stage IV patients usually died within
6 months with a few responding to systemic chemotherapy. These results suggest
that there is a need for randomized trials for these patients.
PMID- 10785474
TI - Elevated serum CA-125 levels in hemodialysis patients with peritoneal, pleural,
or pericardial fluids.
AB - OBJECTIVE: Serum CA-125, an ovarian tumor marker, is used especially in the
follow-up of ovarian cancer for monitoring the efficacy of therapy and for early
detection of recurrence. A number of benign gynecologic as well as benign and
malignant nongynecologic conditions are associated with elevated serum CA-125
levels. Malignant and nonmalignant serosal fluids were also found to be
associated with high serum levels of CA-125, suggesting that the presence of
fluid in the serosal cavities may stimulate its release. METHODS: We performed a
clinical study in 39 patients (21 females, 18 males) on chronic hemodialysis who
were divided into two groups based on the presence of fluid in the serosal
cavities (peritoneum, pleura, or pericardium) without clinical and radiologic
evidence of neoplasia. There were 26 patients (16 females, 10 males) aged 50.11
+/- 13.86 years (range, 20-76 years) in the serosal fluid-negative group (group
1) and 13 patients (8 females, 5 males) aged 45.30 +/- 18.84 years (range, 17-73
years) in the serosal fluid-positive group (group 2). The control group consisted
of 52 healthy volunteers (30 females, 22 males) aged 44.19 +/- 12.59 years
(range, 19-68 years). RESULTS: Significantly elevated serum CA-125 levels were
found in hemodialysis patients with serosal fluid (P < 0.05) when compared with
both the hemodialysis patients without serosal fluid and the control group. There
was no statistically significant difference between the control group and the
patients without serosal fluids (P > 0.05). CONCLUSION: Although CA-125 can be
considered a reliable tumor marker in patients undergoing hemodialysis, it should
be interpreted with caution in patients with serosal fluids.
PMID- 10785475
TI - Correlation of drug response with the ATP tumorchemosensitivity assay in primary
FIGO stage III ovarian cancer.
AB - OBJECTIVE: Our purpose was to: (a) study the in vitro chemosensitivity of primary
epithelial ovarian cancer to drug combinations with cisplatin (CDDP), carboplatin
(CBDCA), paclitaxel (PTX), epirubicin (EPI), or cyclophosphamide (CTX) utilizing
the ATP tumorchemosensitivity assay (ATP-TCA); (b) correlate the test results
with clinical response in patients with FIGO stage III ovarian cancer; and (c)
analyze the most useful parameters for interpretation of test results. METHODS:
CBDCA/CTX, CBDCA/PTX, CDDP/PTX, and EPI/PTX were tested in 93 fresh human primary
epithelial ovarian cancer specimens. Correlations of in vitro drug
sensitivity/resistance and clinical response were performed in 38 patients with
FIGO stage III disease utilizing Fisher's exact test and by comparison of
progression-free (PFS) and overall survival (OS) between those testing as
sensitive or resistant. A progression-free interval of more than 12 months
following surgery was classified as clinical response. ATP-TCA results were
analyzed using the median effective dose, area under the curve, or a defined
sensitivity index. RESULTS: Evaluable test results were achieved in 83 of 93
patients (89%). EPI/PTX had the highest in vitro activity (P < 0.001). In the
clinical correlation, 29 of 38 patients (76%) were classified as in vitro
sensitive (sensitivity index [SI] <250) and 9 patients as in vitro resistant (SI
>250). The SI was superior for interpretation of test results. Patients testing
as chemosensitive had a significantly longer mean PFS (28.5 vs 12.6 months, P =
0.033) and OS (46.1 vs 17.6, P = 0.03) compared to those patients predicted to be
resistant. The assay demonstrated a sensitivity, specificity, and positive and
negative predictive value of 95, 44, 66, and 89%, respectively (Fisher's exact
test, P = 0. 007). CONCLUSION: The observed in vitro efficacy of EPI/PTX in
primary epithelial ovarian cancer specimens warrants further clinical evaluation.
The high evaluability rate and the observed correlation with PFS and OS, within
the limitations of a nonrandomized study, support the use of the ATP
chemosensitivity assay in future prospective assay-directed trials.
PMID- 10785476
TI - Neoadjuvant intraarterial infusion chemotherapy in patients with stage IB2-IIIB
cervical cancer.
AB - OBJECTIVES: The purpose of this study was determine the effect of neoadjuvant
intraarterial chemotherapy (NAIC) on the prognosis of patients with locally
advanced cervical cancer. METHODS: From January 1992 to December 1997, 26
previously untreated patients with stage IB2-IIIB cervical cancer were enrolled
in the study. NAIC was administered for more than two courses every 3 weeks using
a combination of 17.5 mg/m(2) bleomycin, 7 mg/m(2) mitomycin-C, and 75 mg/m(2)
cisplatin via the bilateral internal iliac artery. Pathologic findings were
evaluated with histologic examinations of surgical specimens. A nonrandomized
control group of 120 patients who underwent conventional treatment between 1980
and 1991 was used for comparison. RESULTS: Nineteen (73.1%) of the 26 patients
responded to initial chemotherapy, permitting a radical hysterectomy with pelvic
lymphadenectomy in 14 patients. The remaining 5 patients received radiotherapy.
One of 7 nonresponders was able to undergo radical surgery. Pathologic complete
responses were found in 4 of the 15 patients who underwent radical surgery. The
incidence of lymph node metastasis, parametrial infiltration, and vascular space
involvement in the 15 patients who received NAIC followed by radical surgery was
significantly lower than that in the control group (13.3, 6.7, and 13.3% vs 54.2,
43.8, and 60.4%). The overall 5-year estimated survival rate was significantly
higher for all 26 patients who received NAIC (80.0%) than for the control group
(59.6%). In stage II and III, the 5-year survival rate for patients who received
NAIC was significantly higher than that in the control group (83.3 and 77.8% vs
68.1 and 49.8%). CONCLUSIONS: These preliminary results suggest that NAIC is able
to eliminate effectively the pathologic risk factors in the pelvic cavity, to
improve the operability in patients with stage IIIB cervical cancer, considered
inoperable, and to improve the prognosis of patients with locally advanced
cervical cancer.
PMID- 10785477
TI - Phase I trial of carboplatin, paclitaxel, etoposide, and cyclophosphamide with
granulocyte colony stimulating factor as first-line therapy for patients with
advanced epithelial ovarian cancer.
AB - OBJECTIVES: The goal of this study was to determine the maximally tolerated doses
(MTDs) of carboplatin, paclitaxel (Taxol), etoposide, and cyclophosphamide (CTEC)
with granulocyte-colony stimulating factor (G-CSF, Filgrastim) support as first
line chemotherapy in women with advanced epithelial ovarian cancer (EOC).
METHODS: Newly diagnosed patients with either stage IV EOC, or stage III EOC and
any amount of gross residual tumor after surgical debulking were eligible to
receive six cycles of CTEC over five different dose levels in this phase I trial
(planned 21-day cycle length). Paclitaxel, carboplatin, and cyclophosphamide were
administered intravenously on Day 1, and oral etoposide was administered on Days
1, 2, and 3. G-CSF was administered beginning Day 4. RESULTS: Twenty patients
received a total of 98 cycles of CTEC over the five dose levels evaluated. Bone
marrow suppression was the major toxic effect, with grade 4 neutropenia and
thrombocytopenia being observed in 25 and 23% of cycles, respectively. The
overall incidence of febrile neutropenia was 10%, and no toxic deaths occurred.
No grade IV thrombocytopenia or febrile neutropenia was observed once the
carboplatin dose was reduced from AUC of 7 to 5. Nonhematologic toxicity was
generally mild (grade 2 or less). Dose-limiting toxicity was not observed at the
highest dose level evaluated in this study, preventing assignment of the MTD. The
clinical complete response rate was 92%, although 15 of 16 evaluable patients
have progressed with a median progression-free interval of 4 months (range, 2-11
months). One patient remains disease-free 9 months from the completion of CTEC.
CONCLUSIONS: The CTEC regimen is well tolerated and highly active. Although the
MTD was not reached in this study, the short median progression-free interval
suggests that this regimen is unlikely to be superior to standard treatment with
paclitaxel and carboplatin. Strategies to optimize the development of future
combination chemotherapy regimens in the treatment of newly diagnosed ovarian
cancer are discussed.
PMID- 10785478
TI - p53 and bcl-2 in epithelial ovarian carcinoma: their value as prognostic
indicators at a median follow-up of 60 months.
AB - OBJECTIVE: p53 is the most common tumor suppressor gene involved with human
malignancies. Mutations in p53 are present in approximately 50% of human
malignancies. bcl-2 is a protooncogene. Expression of its protein product is
related to better prognosis in several malignancies. METHODS: One hundred and
three patients with epithelial ovarian carcinoma were studied.
Immunohistochemical staining using the pAb1801 monoclonal antibody to p53 and the
anti-bcl-2 124 monoclonal antibody to bcl-2 was performed. Image analysis was
used to measure percentage positive nuclear area staining of mutant p53. In
addition to bcl-2 and p53, FIGO stage, grade, histology, and level of
cytoreduction were analyzed as prognostic factors. Univariate as well as Cox
regression analysis was performed. RESULTS: One hundred and three patients were
followed for a mean of 60 months. Twenty patients had FIGO stage I disease, 4
stage II, 59 stage III, and 20 stage IV. Immunohistochemical staining for mutant
p53 was not significantly related to DNA index (P = 0.99) but was related to
increasing FIGO stage (P < 0.001) and increasing histologic grade (P = 0.039).
Using Cox regression analysis, increased mutant p53 staining was an independent
predictor of survival in these patients (P = 0.0032), along with stage (P < 0.
0001) and level of cytoreduction (P < 0.0001). Although by itself bcl-2 was not
an independent prognostic indicator (P = 0.18), the combination of p53 and bcl-2
was independently predictive of survival (P = 0.038). CONCLUSION: This study
confirms the authors' earlier report on the importance of p53 as a prognostic
indicator of survival in ovarian carcinoma. Cox regression analysis reveals
mutant p53 staining to be a better independent indicator of prognosis and
survival in patients with ovarian carcinoma than the combination of bcl-2 and
p53.
PMID- 10785479
TI - Molecular genetic analysis of malignant ovarian germ cell tumors.
AB - OBJECTIVE: Relatively little is known about the molecular mechanisms involved in
the initiation and progression of ovarian germ cell tumors (OGCTs), in contrast
to testicular germ cell tumors (TGCTs) which have been extensively investigated.
Ovarian germ cell tumors share many pathological and biological features with
TGCTs and it is likely that they share similar molecular genetic alterations,
although this has not been studied in detail. The aim of this study was to
compare and contrast loss of heterozygosity (LOH) in OGCTs at chromosomal regions
that are commonly involved in TGCTs. METHODS: Universal amplification was
performed on 35 paired specimens of malignant OGCT and constitutional DNA that
had been microdissected from single paraffin-embedded tissue sections in 32
patients. Sixty-two microsatellite markers were used to assess LOH at chromosomal
regions mapping to 3q, 5q, 9p, 11p, 11q, 12q, 17p, and 18q as these are commonly
involved in testicular germ cell tumors. RESULTS: Assessment of these regions
demonstrated common sites of deletion at 3q27-q28 (50%), 5q31 (33%), 5q34-q35
(46%), 9p22-p21 (32%) and 12q22 (53%) in all histological subtypes of OGCT. We
and others have previously found these regions to be frequently deleted at early
stages of tumor development in TGCTs. CONCLUSIONS: These chromosomal regions may
contain tumor suppressor genes that are important in the initiation and
progression of both malignant OGCTs and TGCTs.
PMID- 10785480
TI - Reproducibility in the assessment of postmenopausal ovaries with transvaginal
ultrasound.
AB - OBJECTIVE: The goal of this study was to evaluate the interexaminer variation in
the assessment of postmenopausal ovaries using transvaginal ultrasound (TVU).
METHODS: One hundred eighty-eight cancer screening trial participants undergoing
TVU were reassessed by a second TVU examination. RESULTS: Although first
examiners tended to describe significantly larger left (P < 0.001) but smaller
right (P = 0.036) ovaries, as well as fewer ovarian abnormalities, examiners
agreed on the test interpretation 93% of the time (kappa = 0.846). In only two
cases (1%) were the differences in interpretation such that the two examiners
recommended different follow-up procedures. CONCLUSIONS: Because of the high
fatality rate of ovarian cancer, early detection remains the best way to combat
this devastating disease. TVU is one screening technique we are currently
evaluating in a cancer screening trial. To help ensure screening test
reproducibility, we have followed explcit protocols for training and certifying
all TVU examiners, as well as for conducting TVU examinations. This study
demonstrates that by adhering to specific training, certification, and
examination protocols, TVU reproducibility is excellent. Such protocols may well
serve as a standard for TVU training and examination.
PMID- 10785481
TI - Primary vaginal and pelvic floor reconstruction at the time of pelvic
exenteration: a study of morbidity.
AB - PURPOSE: The purpose of this study was to analyze our experience with the
influence of reconstructive techniques at the time of pelvic exenteration on
morbidity. MATERIALS AND METHODS: Between June 1986 and December 1998, 60 pelvic
exenterations for gynecologic malignancies were performed in our hospital. Forty
five were selected for this study because they met two criteria: they were
performed by the same team (gynecologic oncologist), and they had similar primary
tumors. There were 38 cervical, 2 vaginal, and 5 uterine malignancies. Sixteen
patients underwent reconstructive surgery: 11 (68.8%) with placement of a
myocutaneous flap with left rectus abdominis, 3 (18.8%) with gracilis muscle, and
2 (12.5%) with the Singapore fasciocutaneous flap. Twenty-nine patients had no
reconstruction. Records were reviewed and statistical analysis was performed.
RESULTS: Attachment of the grafts was complete in 14 of 16 (87.5%), with a
partial vulvovaginal dehiscence in 2 cases. Morbidities included secondary
infection in 3 (18.8%), partial necrosis in 3 (18.8%), and partial stenosis in 5
(31.6%); the last was significantly associated with a gracilis flap (P = 0.015).
There were no statistical differences between neovagina and nonneovagina groups
with respect to the rate of fever, small bowel fistula, bowel obstruction, wound
infection or dehiscence, hernia, colorectal leak, colostomy or urostomy prolapse,
deep vein thrombosis, pulmonary embolism, intraoperative blood transfusions, or
hospital stay. There were no pelvic abscesses in the neovagina group compared
with 27% (6/29) in the other group (P = 0.050). Surgery was significantly longer
(P = 0.019) for the reconstructive surgery group, with no statistical difference
between different kinds of flaps. There were no deaths in either group.
CONCLUSIONS: Reconstruction of the vagina and pelvic floor at the time of pelvic
exenteration can be done safely. Although this increases surgical time, morbidity
is not significantly increased. The rectus abdominis flap seems to be the
preferable option for primary vaginal and pelvic floor reconstruction.
PMID- 10785482
TI - Ovarian endometriosis associated with ovarian carcinoma: a clinicopathological
and immunohistochemical study.
AB - OBJECTIVE: The purpose of this study was to demonstrate the incidence, the
histopathological characteristics, and the proliferation activity of
endometriosis and atypical endometriosis associated with ovarian carcinoma.
METHODS: Microscopic slides of primary lesions from 127 patients with primary
ovarian carcinoma were reviewed. The presence or absence of endometriosis and the
transitions from typical endometriosis to atypical endometriosis and from
atypical endometriosis to carcinoma were also histologically evaluated. Ki-67
immunoreactivity of typical and atypical endometriosis and carcinoma was
examined. In addition, endometrial metaplasias were also evaluated. RESULTS: Of
the 127 patients, 37 had endometriosis: 70% (30/43) had clear cell
adenocarcinoma, 43% (3/7) had endometrioid adenocarcinoma, 7% (4/60) had serous
adenocarcinoma, and none (0/17) had mucinous adenocarcinoma. Thirty-three cases
showed typical endometriosis and 29 cases had atypical endometriosis (25 cases
had both). Tufting and the stratification of the lining epithelium were observed
in 25 and 23 cases, respectively. The transition from typical endometriosis to
atypical endometriosis was observed in 22 cases, and the transition from atypical
endometriosis to carcinoma, in 23 cases. Only one case showed a direct transition
from typical endometriosis to carcinoma. The mean Ki-67 indices were as follows:
ovarian carcinoma, 23.1; atypical endometriosis, 9.9; typical endometriosis, 2.7.
In 18 cases with metaplasia in endometriosis, eosinophilic metaplasia and
ciliated metaplasia were the most common types. Five cases had two types of
metaplasia. CONCLUSIONS: Ovarian carcinomas, especially clear cell and
endometrioid adenocarcinomas, are highly associated with endometriosis. Atypical
endometriosis shows proliferation activity intermediate to those of typical
endometriosis and ovarian carcinoma, suggesting it is a precancerous status.
PMID- 10785483
TI - High-risk group in node-positive patients with stage IB, IIA, and IIB cervical
carcinoma after radical hysterectomy and postoperative pelvic irradiation.
AB - OBJECTIVE: The goal of this study was to identify risk factors in patients with
node-positive stage IB, IIA, and IIB cervical carcinoma after radical
hysterectomy with pelvic lymph node dissection and postoperative irradiation.
METHODS: Two hundred forty-two patients with FIGO stage IB, IIA, and IIB cervical
carcinoma underwent radical hysterectomy with pelvic lymph node dissection;
pathological analysis of the surgical specimen showed positive lymph nodes in 59
patients. These 59 patients were further treated with postoperative radiotherapy.
Eighteen patients were in stage IB, 4 in stage IIA, and 37 in stage IIB.
Histological tumor type, tumor size, lymph-vascular space invasion, parametrium
infiltration, number of positive nodes, and involvement of common iliac nodes
were assessed for correlation with cancer recurrence. RESULTS: When all these
variables were assessed in the Cox proportional regression analysis, parametrium
infiltration (P = 0. 0199) and number of positive nodes (two or more nodes) (P =
0.0483) revealed the factor correlating significantly with disease-specific
survival. Based on these two factors, node-positive patients could be divided
into low-risk (n = 11), intermediate-risk (n = 29), and high-risk (n = 19)
groups. The 5-year disease-specific survival for the low-risk group was 100%
which was significantly better than the 39.1% for the high-risk group (P =
0.0012). CONCLUSION: For patients in the high-risk group, it may be worthwhile to
consider new strategies to improve survival.
PMID- 10785484
TI - Granular cell tumors: a new clinically important histologic finding.
AB - OBJECTIVE: The objective of this study was to review clinical characteristics,
histological findings, and surgical treatment of patients with granular cell
tumors of the vulva at Hartford Hospital and examine histologic characteristics
associated with those cases that recurred. MATERIALS AND METHODS: A retrospective
case review of 13 patients diagnosed with granular cell tumors of the vulva at
Hartford Hospital from April 1982 through May 1998 was undertaken to compare age,
size and location of the lesion, histopathologic features, presenting symptoms,
progression of disease, and treatment. RESULTS: Tumor growth patterns were
divided into those with confluent expansile growth (nodular) and those that
infiltrated the dermis and soft tissue in a haphazard fashion interdigitating
with native connective tissue and skin appendages (infiltrative). The advancing
edge of the tumors was assessed as having either a "pushing" or an infiltrative
border. The advancing edge of the tumor was noted to be irregular and
infiltrative in 8 of the 13 cases. The tumor edge in the remaining 5 was pushing
and well demarcated. Five of the eight tumors with an infiltrative edge recurred
despite the fact that 3 of the 5 cases had negative surgical margins at
resection. None of the 5 cases with "pushing" borders developed recurrence.
CONCLUSIONS: Although rare, vulvar tumors are the most common variety of granular
cell tumors encountered in the female genital tract. Histologic evaluation seems
to indicate that patients are more likely to have a recurrence if an infiltrative
growth pattern is present at the advancing edge of the granular cell tumor even
with negative margins at resection. An appropriate management strategy may be to
recommend reexcision of "infiltrative border" lesions rather than clinical
observation alone.
PMID- 10785485
TI - Complete groin lymphadenectomy with preservation of the fascia lata in the
treatment of vulvar carcinoma.
AB - OBJECTIVE: The goal of this study was to assess the local groin recurrence of
vulvar carcinoma in patients treated by complete groin node dissection with
preservation of the fascia lata (GNDPFL). METHODS: This study is a retrospective
chart review of 60 patients with Stage I-IV vulvar carcinoma who underwent
radical vulvectomy and GNDPFL between 1990 and 1998. All superficial inguinal
nodes and the deep femoral nodes on the anterior and medial surfaces of the
femoral vein within the fossa ovalis were removed en bloc while sparing the
fascia lata and the cribriform fascia over the femoral artery. RESULTS: Of the 60
study patients, 14 patients had Stage I disease, 20 Stage II, 21 Stage III, and 5
Stage IV. The mean number of nodes removed was 10 per groin. Thirty-nine patients
had benign nodes on groin dissection. None of these 39 patients developed cancer
recurrence in the dissected groins. Twenty-one of the sixty study patients (34%)
had malignant nodes on groin dissection. Of these 21 patients, 2 experienced
cancer recurrence in the groins. Our study describes a groin recurrence rate of
7.6% in patients with fewer than three malignant unilateral groin nodes.
Postoperatively, 13% of patients developed lymphedema and 15% formed lymphoceles.
CONCLUSIONS: The zero groin recurrence rate in patients with negative nodes and
the low rate of recurrence in patients with positive nodes indicate that groin
lymphadenectomy with preservation of fascia lata is complete, therapeutic, and
comparable to radical techniques of lymphadenectomy involving skeletonization of
femoral vessels, resection of fascia lata, and muscle transposition.
PMID- 10785486
TI - Germline BRCA2 mutation in a patient with fallopian tube carcinoma: a case
report.
AB - OBJECTIVES: Fallopian tube carcinoma is similar to ovarian and peritoneal
carcinoma with respect to histology, response to chemotherapy, and prognosis.
BRCA germline mutations have been commonly reported in ovarian and peritoneal
carcinoma but rarely in other gynecologic cancers. METHODS: A patient with
fallopian tube carcinoma and a family history of ovarian carcinoma underwent
genetic counseling and BRCA testing as did her daughter. RESULTS: The patient and
her daughter were found to have a germline BRCA2 mutation. CONCLUSION: Like a
family history of ovarian or peritoneal carcinoma, the occurrence of fallopian
tube cancer should alert the clinician to the possibility of an abnormality in
the breast cancer susceptibility 1 or 2 genes.
PMID- 10785487
TI - Declining CA-125 in an ovarian cancer patient with progression of measurable
disease: a rational hypothesis for discordant results.
AB - OBJECTIVES: While a declining CA-125 has been demonstrated to be a useful
indicator of response to chemotherapy in ovarian cancer, occasional patients will
demonstrate discordant results between the level of this antigen and changes in
the size of measurable tumor masses. CASE: The patient was seen in the
Gynecologic Oncology Program of the Cleveland Clinic Taussig Cancer Center.
RESULTS: This patient exhibited a "major response" by CA-125 criteria,
significant shrinkage of multiple peritoneal and perirectal implants, but clear
progression of a pelvic side wall mass. The discordant results in this case are
likely an example of a "mixed response" to the chemotherapy regimen, with the
declining CA-125 corresponding to shrinkage of the responding tumor cell
population. CONCLUSION: An evaluation of changes in both the serum CA-125 level
and measurable masses may represent a more complete analysis of the status of
disease in an individual with ovarian cancer.
PMID- 10785488
TI - Signet ring stromal tumor of the ovary occurring in conjunction with brenner
tumor.
AB - OBJECTIVE: A case is presented of a single ovarian mass that had elements of both
signet ring stromal tumor of the ovary and Brenner tumor. METHODS: The histologic
features and the results of histocytochemical, immunohistochemical, and electron
microscopic studies are presented. RESULTS: The signet ring component of the mass
demonstrated features consistent with the few other cases previously reported. A
positive immunohistochemical stain for the peptide hormone inhibin provides
additional evidence for an ovarian stromal origin for this tumor. CONCLUSION: The
tumor produced no hormonally related symptoms and has shown no evidence of
recurrence. Signet ring stromal tumor of the ovary is an uncommon benign tumor
that may be confused with metastatic signet ring carcinoma. The significance of
the signet ring cells is not certain. Their association with Brenner tumor has
not been previously described.
PMID- 10785489
TI - Erosion of an intraperitoneal chemotherapy catheter resulting in an enterovaginal
fistula.
AB - BACKGROUND: With the pharmacokinetic advantages of intraperitoneal chemotherapy
delivery and the increased popularity of immunotherapy and gene therapy,
intraperitoneal catheters have moved to the forefront as a delivery system in
cancer treatment. This delivery system, however, carries with it an intrinsic
morbidity warranting attention in the often prolonged chemotherapy regimens
demanded by cancer patients. CASE: In reviewing the literature of intraperitoneal
catheter complications, there is no other cited case of a peritoneal catheter
erosion into intestine presenting as an enterovaginal fistula. Our patient,
diagnosed with persistent ovarian carcinoma, had a peritoneal Tenckoff catheter
placed for chemotherapy. Many months after termination of the chemotherapy and 15
months after placement, she presented with bowel contents per vagina. A CT scan
revealed an abdominopelvic abscess encompassing the detached catheter which
embedded in the rectosigmoid colon, allowing direct communication to the upper
vagina. The catheter was removed and the abscess was drained. CONCLUSION:
Intraperitoneal catheters have a morbidity that persists after nonuse. Therefore,
intraperitoneal catheters should be removed if they are not being used.
PMID- 10785490
TI - Urolithiasis following formation of a continent urostomy: case report and review
of the literature.
AB - BACKGROUND: Formation of urinary stones in a continent urostomy (Indiana pouch)
has been described as a late complication. Management of a patient with
symptomatic multiple large stones and review of the literature are outlined. CASE
REPORT: A 32-year-old woman presented with recurrent urinary tract infections and
pyelonephritis 6 years after a total pelvic exenteration and creation of a
continent urostomy for central recurrent carcinoma of the cervix after radical
pelvic radiation. Multiple large stones were found to be the underlying etiology.
Laparotomy, enterocystotomy, and removal of stones were performed without
apparent complication. CONCLUSION: It is recommended that for single calculi or
multiple small stones, electroshock wave lithotripsy or the percutaneous
endoscopic approach be considered. For larger stones the use of laparotomy and
enterocystostomy may be appropriate.
PMID- 10785491
TI - Recurrent invasive adenocarcinoma after hysterectomy for cervical adenocarcinoma
in situ.
AB - BACKGROUND: Unlike its squamous counterpart, therapy for cervical adenocarcinoma
in situ with positive endocervical cone margin remains controversial. CASE: A 52
year-old gravida 2, para 1,0,1,1, presented with vaginal bleeding. Gynecologic
history was significant for cervical cold knife conization with a positive
endocervical margin and endocervical curettage with atypical endocervical cells.
Repeat cone biopsy was considered unsafe given the large initial cone specimen.
An extrafascial hysterectomy was performed 5 weeks later and pathology confirmed
a disease-free cervix. Pap smear performed 1 year later was interpreted as
recurrent adenocarcinoma but later downgraded to inflammation. Inspection and
random biopsies of the vaginal cuff revealed only inflammation. Two subsequent
Pap smears also returned inflammation. Seventeen months after the hysterectomy
physical examination revealed a 2 x 3-cm smooth mass at the vaginal cuff. Biopsy
revealed invasive adenocarcinoma. The patient underwent an upper vaginectomy
followed by postoperative pelvic radiation. CONCLUSION: This case suggests that
despite extrafascial hysterectomy for presumed adenocarcinoma in situ of the
cervix, a residual focus could remain and present later as invasive
adenocarcinoma.
PMID- 10785492
TI - Vascular embolization of benign granulosa cells.
AB - OBJECTIVE(S): Most conditions involving sex cord-stromal cells can be diagnosed
on morphologic criteria alone. We describe a case of vascular embolization of
benign granulosa cells in which immunohistochemistry was of value as a diagnostic
tool. METHODS: We reviewed the clinical history and gross pathologic findings
from a 48-year-old patient who presented with abdominal pain and fullness.
Formalin-fixed paraffin-embedded sections were examined by routine H&E and
immunohistochemical stains. RESULTS: Histologic examination of a grossly enlarged
and cystic ovary revealed nests of cells within angiolymphatic spaces. Although
the cells were cohesive and atypical, they were morphologically similar to the
nearby graafian follicle. Immunohistochemistry showed positive labeling with
antibodies to inhibin-alpha and cytokeratin in a pattern consistent with benign
granulosa cells. CONCLUSION(S): Immunohistochemical stains for inhibin-alpha and
cytokeratin are useful tools to help confirm granulosa cell origin, as
demonstrated in this case involving an atypical histomorphologic picture of
"embolization."
PMID- 10785493
TI - The definition of stage IA(1) cervical adenocarcinoma and selection criteria for
nonradical surgical management.
PMID- 10785494
TI - Reply
PMID- 10785495
TI - Adjuvant chemotherapy or radiotherapy in cervical cancer.
PMID- 10785497
TI - Reply
PMID- 10785498
TI - Reply
PMID- 10785496
TI - Is florid pyloric metaplasia different from adenoma malignum?
PMID- 10785500
TI - In memoriam : Francis X. Witkowski.
PMID- 10785499
TI - Surgical response of advanced-stage borderline ovarian tumors to paclitaxel and
cisplatin chemotherapy.
PMID- 10785501
TI - Making sense out of oxygen sensor.
PMID- 10785502
TI - Bone sialoprotein and the paradox of angiogenesis versus atherosclerosis.
PMID- 10785503
TI - Gene therapy for restenosis.
PMID- 10785504
TI - Polymorphisms of the beta(2)-adrenergic receptor determine exercise capacity in
patients with heart failure.
AB - The beta(2)-adrenergic receptor (beta(2)AR) exists in multiple polymorphic forms
with different characteristics. Their relevance to heart failure (HF) physiology
is unknown. Cardiopulmonary exercise testing was performed on 232 compensated HF
patients with a defined beta(2)AR genotype. Patients with the uncommon Ile164
polymorphism had a lower peak VO(2) (15.0+/-0.9 mL. kg(-1). min(-1)) than did
patients with Thr164 (17.9+/-0.9 mL. kg(-1). min(-1), P<0.0001). The percentage
achieved of predicted peak VO(2) was also lower in patients with Ile164 (62. 3+/
4.5% versus 71.5+/-5.1%, P=0.045). The relative risk of a patient having a VO(2)
=14 mL. kg(-1). min(-1) who had Ile164 was 8.0 (P=0.009). Catheterization-based
invasive exercise testing revealed depressed changes in the exercise-induced
cardiac index, systemic vascular resistance, stroke volume, and VO(2) in patients
with Ile164. The polymorphisms at position 16 also impacted exercise capacity:
peak VO(2) for Arg16 versus Gly16 was 17.0+/-0.8 versus 15. 6+/-0.5 mL. kg(-1).
min(-1), respectively (P=0.03). Because the polymorphisms at loci 16 and 27 can
occur together, 4 homozygous combinations exist. Patients with Arg16/Glu27 had
the highest percentage achieved of predicted peak VO(2) (75. 7+/-6.4%), whereas
those with Gly16/Gln27 had the lowest (55.3+/-2. 8%, P=0.0032). The above
findings were not confounded by baseline clinical characteristics, including beta
blocker usage. We conclude that the beta(2)AR polymorphisms Ile164, Gly16, and
the combination of Gly16 and Gln27 are associated with depressed exercise
performance in HF and represent a genetically determined factor in the
pathophysiology of HF.
PMID- 10785505
TI - Functional deletion mutation of the 5'-flanking region of type A human
natriuretic peptide receptor gene and its association with essential hypertension
and left ventricular hypertrophy in the Japanese.
AB - The natriuretic peptide (NP) family is involved in the regulation of blood
pressure and fluid volume. We isolated the 5'-flanking region of the type A human
NP receptor gene and identified an insertion/deletion mutation in this region. We
then assessed whether there is a genetic association between this mutation and
essential hypertension (EH). The deletion allele lacks 8 nucleotides and alters
binding sites for the activator protein-2 (AP-2) and Zeste transcriptional
factors. We genotyped 200 EH and 200 normotensive (NT) individuals and found 9
subjects with the deletion (8 in the EH group and 1 in the NT group). All 9
individuals were heterozygous. The NT subject with the mutation had left
ventricular hypertrophy without hypertension. Transcriptional activity of the
deletion allele was <30% that of the wild-type allele. The plasma levels of brain
NP in EH patients with the deleted allele were significantly higher than the
levels in the EH patients with the wild-type allele, and plasma brain NP levels
were significantly higher in subjects with the deleted allele than in subjects
with the wild-type allele, despite comparable blood pressures. These findings
suggest that in Japanese individuals, this deletion in the human NP receptor gene
reduces receptor activity and may confer increased susceptibility to developing
EH or left ventricular hypertrophy.
PMID- 10785506
TI - Increased expression of cytoskeletal, linkage, and extracellular proteins in
failing human myocardium.
AB - Experimental studies have shown that in hypertrophy and heart failure,
accumulation of microtubules occurs that impedes sarcomere motion and contributes
to decreased ventricular compliance. We tested the hypothesis that these changes
are present in the failing human heart and that an entire complex of structural
components, including cytoskeletal, linkage, and extracellular proteins, are
involved in causing functional deterioration. In explanted human hearts failing
because of dilated cardiomyopathy (ejection fraction =20%), expression of alpha
and beta-tubulin, desmin, vinculin, fibronectin, and vimentin was determined by
Northern and Western blot analysis and compared with normal myocardium from
explants not used for transplantation. The mRNA for alpha- and beta-tubulin was
increased to 2.4-fold (P<0.01) and 1.25-fold (NS), respectively; for desmin, 1.2
fold (P<0.05); for fibronectin, 5-fold (P<0.001); and for vimentin, 1.7-fold
(P<0.05). Protein levels for alpha-tubulin increased 2.6-fold (P<0.02); for beta
tubulin, 1.2-fold (P<0.005); for desmin, 2.1-fold (P<0.001); for vinculin, 1.2
fold (P<0.005); for fibronectin, 2.9-fold (P<0.001); and for vimentin, 1.5-fold
(P<0. 005). Confocal microscopy showed augmentation and disorganization of all
proteins studied. In combination with the loss of myofilaments and sarcomeric
skeleton previously reported, these changes suggest cardiomyocyte remodeling.
Increased fibronectin and elevated interstitial cellularity (vimentin labeling)
indicate progressive fibrosis. The present results suggest a causative role of
cytoskeletal abnormalities and myofilament loss for intrinsic contractile and
diastolic dysfunction in failing hearts.
PMID- 10785507
TI - Phenotypic and functional changes in regenerated porcine coronary endothelial
cells : increased uptake of modified LDL and reduced production of NO.
AB - Porcine coronary arteries with regenerated endothelium exhibit impaired
endothelium-dependent relaxations. Experiments were designed to analyze the
structural and functional changes occurring in regenerated endothelial cells.
Primary cultures from regenerated endothelium contained giant endothelial cells,
with an increased number of cells with diameter >14.5 microm, a reduced ability
to proliferate, and signs of apoptosis. The uptake of fluorescent acetylated LDL
was increased 2-fold in cultures from regenerated endothelium. The increased
uptake of acetylated LDL was confirmed ex vivo in injured coronary arteries. In
cultures from regenerated endothelium, cGMP production was decreased under basal
conditions and during stimulation with serotonin, bradykinin, and A23187. Thus,
during regeneration, there is accelerated senescence of endothelial cells
accompanied by increased incorporation of modified LDL and reduction of NO
production without decrease in endothelial NO synthase expression. These
alterations help to explain the altered endothelium-dependent responses 28 days
after balloon injury.
PMID- 10785508
TI - Effects of hypoxia on isometric force, intracellular Ca(2+), pH, and energetics
in porcine coronary artery.
AB - When exposed to hypoxic conditions, coronary arteries dilate, which is an
important protective response. Although vessel sensitivity to oxygen is well
documented, the mechanisms are not known with certainty. To further characterize
the mechanisms of oxygen sensing in the coronary artery, we tested the major
classes of hypotheses by measuring the effects of hypoxia on energetics,
[Ca(2+)](i), K(+) channel function, and pH(i). Hypoxia relaxes porcine coronary
arteries stimulated with either KCl or U46619. The extent of relaxation is
dependent on both the degree and kind of stimulation. [Ca(2+)](i) was measured in
endothelium-denuded arteries using fura 2-AM and ratiometric fluorescent
techniques. At lower stimulus levels, hypoxia decreased both force and
[Ca(2+)](i). Inhibitor studies suggest that K(Ca) and K(ATP) channels are not
involved in the hypoxic relaxation, whereas K(V) channels may play a minor role,
if any. Despite the hypoxia-mediated decrease in force, [Ca(2+)](i) was unchanged
or increased at high levels of stimulation. Despite a marked increase in lactate
content, pH(i) (measured with the ratiometric fluorescent dye BCECF) was also
little affected by hypoxia. Measurement of the phosphagen and metabolite profile
of freeze-clamped arteries with analytical isotachophoresis indicated that
hypoxia increased lactate content by 4-fold and decreased phosphocreatine to 60%
of control. However, neither ATP nor P(i) was affected by hypoxia. Interestingly,
additional stimulation under hypoxia increased force but not ATP utilization, as
estimated from measurements of anaerobic lactate production. Thus, surprisingly,
the economy of force maintenance is increased under hypoxia. In porcine coronary
artery, both Ca(2+)-dependent and, importantly, Ca(2+)-independent mechanisms are
involved in hypoxic vasodilatation. For the latter, mechanisms involving either
ATP, [Ca(2+)](i), pH(i), or P(i) cannot be invoked. This novel oxygen sensing
mechanism involves a decreased Ca(2+) sensitivity.
PMID- 10785509
TI - Remodeling of gap junctional coupling in hypertrophied right ventricles of rats
with monocrotaline-induced pulmonary hypertension.
AB - The present study investigates the remodeling of gap junctional organization in
relation to changes in anisotropic conduction properties in hypertrophied right
ventricles (RVs) of rats with monocrotaline (MCT)-induced pulmonary hypertension.
In contrast to controls that showed immunolocalization of connexin43 (Cx43)
labeling largely confined to the intercalated disks, RV myocytes from MCT-treated
rats showed dispersion of Cx43 labeling over the entire cell surface. The
disorganization of Cx43 labeling became more pronounced with the progression of
hypertrophy. Desmoplakin remained localized to the intercalated disks, as in
controls. In RV tissues, the proportion of Cx43 label at the intercalated disk
progressively decreased. Quantitative analysis of en face views of intercalated
disks revealed a significant decrease in the disk gap junctional density in RV
tissues of MCT-treated rats (control, 0.18 versus MCT-treated, 0.14 at 2 weeks;
control, 0.16 versus MCT-treated, 0.11 at 4 weeks). Conduction velocity in RVs
parallel to the fiber orientation was significantly lower (30.2% [n=9]) in MCT
treated rats at 4 weeks than in control rats, whereas there was no significant
difference observed in the conduction velocity across the fiber orientation
between control and MCT-treated rats. The anisotropic ratio of MCT-treated rats
(1.38+/-0.10) was significantly lower than that of control rats (1.98+/-0.12).
These results suggest that RV hypertrophy induced by pressure overload is
associated with both disorganization of gap junction distribution and alteration
of anisotropic conduction properties.
PMID- 10785510
TI - Arterial paclitaxel distribution and deposition.
AB - Successful implementation of local arterial drug delivery requires transmural
distribution of drug. The physicochemical properties of the applied compound,
which govern its transport and tissue binding, become as important as the mode of
delivery. Hydrophilic compounds distribute freely but are cleared rapidly.
Hydrophobic drugs, insoluble in aqueous solutions, bind to fixed tissue elements,
potentially prolonging tissue residence and biological effect. Paclitaxel is such
a hydrophobic compound, with tremendous therapeutic potential against
proliferative vascular disease. We hypothesized that the recent favorable
preclinical data with this compound may derive in part from preferential tissue
binding as a result of unique physicochemical properties. The arterial transport
of paclitaxel was quantified through application ex vivo and measurement of the
subsequent transmural distribution. Arterial paclitaxel deposition at equilibrium
varied across the arterial wall and was everywhere greater in concentration than
in the applied drug source. Permeation into the wall increased with time, from 15
minutes to 4 hours, and varied with the origin of delivery. In contrast to
hydrophilic compounds, the concentration in tissue exceeds the applied
concentration and the rate of transport was markedly slower. Furthermore,
endovascular and perivascular paclitaxel application led to markedly differential
deposition across the blood vessel wall. These data suggest that paclitaxel
interacts with arterial tissue elements as it moves under the forces of diffusion
and convection and can establish substantial partitioning and spatial gradients
across the tissue. The complexity of paclitaxel pharmacokinetics requires in
depth investigation if this drug is to reach its full clinical potential in
proliferative vascular diseases.
PMID- 10785511
TI - Bone sialoprotein mediates human endothelial cell attachment and migration and
promotes angiogenesis.
AB - Bone sialoprotein (BSP) is a secreted glycoprotein primarily found in sites of
biomineralization. Recently, we demonstrated that BSP is strongly upregulated in
osteotropic cancers and particularly those that exhibit microcalcifications. BSP
contains an Arg-Gly-Asp (RGD) motif found in other adhesive molecules that
interact with cellular integrins. In bone, BSP has been shown to mediate the
attachment of osteoblasts and osteoclasts via alpha(v)beta(3) integrin receptors.
Ligands for alpha(v)beta(3) integrin are considered to play a central role during
angiogenesis. Therefore, we used human umbilical vein endothelial cells (HUVECs)
to study the potential role of BSP in angiogenesis. We found that purified
eukaryotic recombinant human BSP (rhBSP) is able to promote both adhesion and
chemotactic migration of HUVECs in a dose-dependent manner. These interactions
involve HUVEC alpha(v)beta(3) integrin receptors and the RGD domain of BSP.
Indeed, HUVECs attach to a recombinant BSP fragment containing the RGD domain,
whereas this response is not observed with the same fragment in which RGD has
been mutated to Lys-Ala-Glu (KAE). A cyclic RGD BSP peptide inhibits both
adhesion and migration of HUVECs to rhBSP. Moreover, anti-alpha(v)beta(3) but not
anti-alpha(v)beta(5) monoclonal antibodies also prevent BSP-mediated adhesion and
migration of HUVECs. We observed that both rhBSP and the RGD BSP recombinant
fragment stimulated ongoing angiogenesis on the chorioallantoic chick membrane
assay. BSP angiogenic activity was inhibited by anti-alpha(v)beta(3) antibody,
and the KAE BSP fragment was inactive. Our findings represent the first report
implicating BSP in angiogenesis. BSP could play a critical role in angiogenesis
associated with bone formation and with tumor growth and metastatic
dissemination.
PMID- 10785512
TI - Vascular endothelial growth factor-stimulated actin reorganization and migration
of endothelial cells is regulated via the serine/threonine kinase Akt.
AB - Vascular endothelial growth factor (VEGF) induces endothelial cell proliferation,
migration, and actin reorganization, all necessary components of an angiogenic
response. However, the distinct signal transduction mechanisms leading to each
angiogenic phenotype are not known. In this study, we examined the ability of
VEGF to stimulate cell migration and actin rearrangement in microvascular
endothelial cells infected with adenoviruses encoding beta-galactosidase (beta
gal), activation-deficient Akt (AA-Akt), or constitutively active Akt (myr-Akt).
VEGF increased cell migration in cells transduced with beta-gal, whereas AA-Akt
blocked VEGF-induced cell locomotion. Interestingly, myr-Akt transduction of
bovine lung microvascular endothelial cells stimulated cytokinesis in the absence
of VEGF, suggesting that constitutively active Akt, per se, can initiate the
process of cell migration. Treatment of beta-gal-infected endothelial cells with
an inhibitor of NO synthesis blocked VEGF-induced migration but did not influence
migration initiated by myr-Akt. In addition, VEGF stimulated remodeling of the
actin cytoskeleton into stress fibers, a response abrogated by infection with
dominant-negative Akt, whereas transduction with myr-Akt alone caused profound
reorganization of F-actin. Collectively, these data demonstrate that Akt is
critically involved in endothelial cell signal transduction mechanisms leading to
migration and that the Akt/endothelial NO synthase pathway is necessary for VEGF
stimulated cell migration.
PMID- 10785514
TI - Cyclooxygenase-2 is required for tumor necrosis factor-alpha- and angiotensin II
mediated proliferation of vascular smooth muscle cells.
AB - Tumor necrosis factor-alpha (TNF-alpha) and angiotensin II (Ang II) induced a
transient increase in vascular smooth muscle cell (VSMC) cyclooxygenase-2 (COX-2)
mRNA accumulation, without affecting COX-1 mRNA levels. The kinetics of COX-2
mRNA accumulation were similar in VSMCs challenged with either TNF-alpha or Ang
II; mRNA accumulation peaked at 2 hours and decreased to control levels by
approximately 6 hours. Accumulation of COX-2 mRNA was associated with a time
dependent increase of COX-2 protein expression that displayed similar kinetics in
response to either TNF-alpha or Ang II. Both the increase in COX-2 mRNA
accumulation and protein expression in response to either TNF-alpha or Ang II
were inhibited by the mitogen-activated protein/extracellular signal-regulated
kinase (MEK) inhibitor PD098059. In addition, the AT(1)-selective receptor
antagonist losartan attenuated the Ang II-mediated increase in COX-2 mRNA
accumulation; the AT(2)-selective antagonist PD123319 had no effect. Prostacyclin
I(2) synthesis was tightly coupled to expression of COX-2, whereas prostaglandin
E(2) and thromboxane A(2) (TXA(2)) synthesis may be associated with differential
usage of COX-1 and COX-2. The COX-2-selective inhibitors NS-398 and nimesulide
and the TXA(2) receptor antagonist BMS 180,291 inhibited TNF-alpha- and Ang II
mediated increases in DNA content and cell number by approximately 95%. These
findings suggest that a prostanoid derived from COX-2, possibly TXA(2), may
contribute to VSMC hyperplasia in vessel injury or pathophysiological conditions
associated with elevated levels of either TNF-alpha or Ang II.
PMID- 10785513
TI - cAMP-dependent vasodilators cross-activate the cGMP-dependent protein kinase to
stimulate BK(Ca) channel activity in coronary artery smooth muscle cells.
AB - cAMP-dependent vasodilators are used to treat a variety of cardiovascular
disorders; however, the signal transduction pathways and effector mechanisms
stimulated by these agents are not fully understood. In the present study we
demonstrate that cAMP-stimulating agents enhance the activity of the large
conductance, calcium-activated potassium (BK(Ca)) channel in single myocytes from
coronary arteries by "cross-activation" of the cGMP-dependent protein kinase
(protein kinase G, PKG). Single-channel patch-clamp data revealed that 10
micromol/L isoproterenol, forskolin, or dopamine opens BK(Ca) channels in
coronary myocytes and that this effect is attenuated by inhibitors of PKG
(KT5823; Rp-8-pCPT-cGMPS), but not by inhibiting the cAMP-dependent protein
kinase (protein kinase A, PKA). In addition, a membrane-permeable analog, CPT
cAMP, also opened BK(Ca) channels in these myocytes, and this effect was reversed
by KT5823. Direct biochemical measurement confirmed that dopamine or forskolin
stimulates PKG activity in coronary arteries but does not elevate cGMP. Finally,
the stimulatory effect of cAMP on BK(Ca) channels was reconstituted in a cell
free, inside-out patch by addition of purified PKG activated by either cGMP or
cAMP. In contrast, channel gating was unaffected by exposure to the purified
catalytic subunit of PKA. In summary, findings from on-cell and cell-free patch
clamp experiments provide direct evidence that cAMP-dependent vasodilators open
BK(Ca) channels in coronary myocytes by cross-activation of PKG (but not via
PKA). Biochemical assay confirmed this cross-activation mechanism of cAMP action
in these arteries. This signaling pathway is a novel mechanism for regulation of
potassium channel activity in vascular smooth muscle and other cells.
PMID- 10785515
TI - Characterization of nitric oxide synthase in the rat parotid gland.
AB - Nitric oxide (NO) acts as an inter- and intracellular signalling molecule of
various cells such as vascular endothelium, macrophages, and neurones. NO is
produced by nitric oxide synthase (NOS) from L-arginine. Here the characteristics
of NOS in the rat parotid gland were investigated. Approximately 74% of total
activity of NOS was present in the cytosolic fraction. For full activation of the
NOS in the cytosolic fraction, tetrahydroxybiopterin, NADPH, Ca(2+) and
calmodulin were needed as cofactors, because the activity was clearly reduced in
the absence of tetrahydroxybiopterin, NADPH, or Ca(2+), or in the absence of
calmodulin and presence of trifluoperazine, a calmodulin antagonist, in the
reaction mixture. The partially purified NOS activity was completely abolished in
the absence of calmodulin or Ca(2+), and activated by them in a dose-dependent
manner; EC(50) for calmodulin and Ca(2+) were 10 and 340 nM, respectively. The
K(m) for L-arginine was 1.57 microM. Immunoblot analysis revealed that a 165-kDa
protein band in the rat parotid gland cytosolic fraction cross-reacted with a
rabbit polyclonal antibody against human brain NOS. These results suggest that
NOS of the rat parotid gland is a neuronal isoform and that its activity is
regulated by physiological concentrations of calmodulin and Ca(2+).
PMID- 10785516
TI - Effect of the sensory neuropeptide antagonists h-CGRP((8-37)) and SR 140.33 on
pulpal and gingival blood flow in ferrets.
AB - In a previous study, it was concluded that the neuropeptides calcitonin gene
related peptide (CGRP) and substance P are released during resting conditions in
the (exposed) ferret dental pulp, contributing to a basal vasodilator tone in the
pulpal vessels. In order to exclude the possibility that the method used elicited
axon reflexes, which might be responsible for neuropeptide release, the present
study was designed without pulp exposure. Non-invasive laser-Doppler flowmetry
was used to measure the effects of intra-arterial infusions of the antagonists h
CGRP((8-37)) and SR 140.33 (neurokinin 1-receptor antagonist) on pulpal and
gingival blood flow before, during and after electrical tooth stimulation.
Infusions of h-CGRP((8-37)) reduced the basal blood flow in the pulp by 31.4+/
5.2% (p<0.001) and in the gingiva by 22.6+/-4.8% (p<0.05). A further significant
decrease in basal blood flow was measured in both pulp and gingiva following SR
140.33 administration. The reduction in blood flow was 16.9+/-1.9% (p<0.005) in
the pulp and 19. 3+/-5.6% (p<0.05) in the gingiva. The systemic arterial pressure
remained unchanged both during and after the periods of infusion. Tooth
stimulation before the antagonist infusion significantly increased the pulpal
blood flow by 71.9+/-15.3% (p<0.005). Infusion of h-CGRP((8-37)) greatly reduced
this electrically induced vasodilatation, indicating that CGRP is the principal
factor responsible for the vasodilatation observed after tooth stimulation. This
study confirms the previous finding that a resting vasodilator tone due to the
release of CGRP and SP exists in the ferret dental pulp. It is concluded that
spontaneous, basal release of the neuropeptides CGRP and substance P exists both
in dental pulp and gingiva in the ferret.
PMID- 10785517
TI - A strain gauge and photoelastic analysis of in vivo strain and in vitro stress
distribution in human dental supporting structures.
AB - Strain gauge and photoelastic experiments have been workhorses of experimental
stress analysis for over 50 years. In this study, both were used to analyse the
nature of stress distribution from the tooth root surface to the supporting
alveolar bone. Such studies help in understanding the behaviour of dental
supporting structures under physiological function. In the strain gauge
experiment, the mechanical strains were measured on the supporting bone surface
and the root surface of the tooth under applied bite force. It was found that
higher strains were distributed along the cervical region of the supporting bone
and the root surface. The photoelastic study was also done to evaluate the stress
distribution pattern from the root surface to the supporting bone under clinical
conditions. The stress patterns were found to decrease from the cervical to the
apical region of the root surface. These studies highlight the role of the
periodontium in stress distribution and bone remodelling.
PMID- 10785518
TI - Expression of bone sialoprotein in mineralized tissues of tooth and bone and in
buccal-pouch carcinomas of Syrian golden hamsters.
AB - The expression of bone sialoprotein (BSP) is normally restricted to mineralized
connective tissues of bones and teeth where it has been associated with mineral
crystal formation. However, recent studies have revealed ectopic expression of
BSP in various lesions, including oral and extraoral carcinomas, in which it has
been associated with the formation of microcrystalline deposits and the
metastasis of cancer cells to bone. To develop a model to study the induction of
BSP in carcinoma development, BSP expression in squamous-cell carcinomas induced
by chemical carcinogen in the hamster cheek-pouch epithelium was investigated.
Hamster BSP cDNA was first isolated and characterized, then used to prepare
probes for Northern and in situ hybridization. The protein sequence of hamster
BSP displayed 86% amino acid identity with a consensus mammalian BSP sequence and
retained polyglutamate sequences, the RGD sequence and sites of phosphorylation,
glycosylation and sulphation. The tissue-specific expression of hamster BSP mRNA
and protein was confirmed by in situ hybridization and immunolocalization in
developing tissues. Squamous-cell carcinomas induced in the buccal pouches of 5
week-old male Syrian golden hamsters treated with chemical carcinogen had BSP
mRNA and BSP in the proliferating neoplastic epithelium. In contrast, neither BSP
mRNA nor the protein could be detected in the stroma within which islands of the
transformed tissue had formed. Thus, the hamster cheek pouch is a well
characterized model that can be used to study the induced expression of BSP in
association with the development of squamous-cell carcinomas.
PMID- 10785519
TI - Isolation of proteoglycan (versican) aggregate from rat dental pulp.
AB - Versican is a large interstitial proteoglycan that is believed to be able to bind
hyaluronan to form large aggregate structures, but no study has isolated native
versican aggregates from any tissue. In this study, ternary aggregate structures
consisting of versican, hyaluronan, and link protein were isolated from rat
dental pulp by associative extractions followed by caesium sulphate rate zonal
sedimentation centrifugation. Fractions from the centrifugation were analysed by
dot blot and Western blot using monoclonal antibodies and hyaluronan-binding
protein. About 60% of the hexuronic acid was extracted by associative
extractions. Positive reactions for versican, hyaluronan and link protein were
clearly detected in the bottom fractions from the centrifugation, but were barely
detectable in the top fractions. These results suggest that the majority of the
versican, hyaluronan, and link protein forms ternary aggregate structures in the
rat dental pulp.
PMID- 10785520
TI - Effects of an anticariogenic casein phosphopeptide on calcium diffusion in
streptococcal model dental plaques.
AB - Casein phosphopeptides (CPP) stabilize amorphous calcium phosphate (ACP) and may
be used to localize ACP in dental plaque, maintaining a state of supersaturation
with respect to tooth enamel, reducing demineralization and enhancing
remineralization. The aim here was to investigate these effects by measuring the
effect of CPP-ACP on calcium diffusion in plaque. Using Dibdin's effusion system,
calcium diffusion was measured in streptococcal model plaques. This demonstrated
that by providing a large number of possible binding sites for calcium, 0.1% CPP
ACP reduces the calcium diffusion coefficient by about 65% at pH 7 and 35% at pH
5. Hence, CPP-ACP binds well to plaque, providing a large calcium reservoir
within the plaque and slowing diffusion of free calcium. This is likely to
restrict mineral loss during a cariogenic episode and provide a potential source
of calcium for subsequent remineralization. Overall, once in place, CPP-ACP will
restrict the caries process.
PMID- 10785521
TI - The effects of food fragmentation index on mandibular closing angle in human
mastication.
AB - Jaw movements were recorded using a three-dimensional magnetic sensing system
(Sirognathograph, Siemens) in 10 human volunteers while chewing standardized
volumes of 15 food types, ranging from soft cheeses to hard nuts. The maximum
horizontal amplitude inside the chewing loop (width of the loop), the height of
the loop (vertical amplitude) and the closing angle made by the jaw during the
late closing phase of the cycle relative to the vertical were calculated. The
most highly significant correlation was between the closing angle and the square
root of the ratio of two mechanical properties of the food - the toughness (R)
and modulus of elasticity (E)(r = -0.85, p<0.001). The width of the chewing loop
was also significantly correlated with the above combination of food properties
(r = -0.75, p<0.01) whereas the vertical amplitude was not. Thus, the mechanical
properties of foods appear to influence the pattern of mandibular movements in
human mastication similarly to their reported effect on food breakdown rates and
anterior temporalis activity during mastication.
PMID- 10785522
TI - The effect of ageing on parenchymal cell populations in adult female mouse
submandibular gland.
AB - The submandibular gland shows an array of responses that accompany ageing, which
are usually modest. However, the submandibular acinar-cell mucin shows a
substantial decline in total amount per gland. In the submandibular gland, there
is also a loss of secretory parenchyma. A number of factors that could influence
either parenchymal loss or a change in its cellular composition were examined in
three ages of adult female mice. The goal was to see if there are ageing-related
cellular changes that might have an effect on mucin production or secretion. The
factors examined included DNA, protein, rates of cell division and apoptosis,
cell volume and cellular composition of the parenchymal population. The
parenchymal cell composition showed significant differences during ageing, with a
substantial decrease in the percentage of acinar cells and increases in the
percentage of both types of ductal cell components. This decline in the
proportion of acinar cells in the parenchyma also reflected an overall reduction
in the total number of acinar cells in the gland. Thus, the change in proportions
of cells may potentially be a direct cause of the ageing-related decline in the
submandibular acinar-cell mucin. The alteration in cellular composition was not
attributable to changes in the cell-division indices; however, there was an
increased rate of apoptosis for acinar cells that was significantly different
between 3 and 28 months. The apoptotic rate doubled for acinar cells but showed
no significant change in ductal cells. This selective change in the rate of
apoptosis with ageing suggests that it is one of the main reasons for the decline
in the proportion of acinar cells in the submandibular gland.
PMID- 10785523
TI - Effects of basic fibroblast growth factor on cultured rat and human submandibular
salivary gland cells.
AB - Basic fibroblast growth factor (bFGF) is a strong mitogen for most mesoderm- and
ectoderm-derived cells. Although bFGF exists in rat and human salivary glands,
its physiological role in those glands is unknown. In this study, the effects of
bFGF were investigated in monolayer culture of normal rat and human submandibular
gland cells. Epithelial cells from rat and human submandibular glands were
cultivated with the aid of 3T3 cells as a feeder layer. The effects of different
concentrations of bFGF on the second passage of these cultured cells were
examined. In both the rat and human cells, the percentage of bromodeoxyuridine
(BrdU)-positive cells gradually increased up to 50 ng/ml, and then increased
sharply at 100 ng/ml. However, at concentrations higher than 100 ng/ml, the
percentages of BrdU-positive cells reached a plateau. In both rat and human
cells, total cell numbers at 100 ng/ml bFGF were significantly higher than those
of the control group from culture day 4. On the other hand, the morphology of the
cultured cells showed no difference either with or without bFGF. These results
indicate that a major effect of bFGF on salivary gland epithelial cells is to act
as a mitogenic stimulus.
PMID- 10785524
TI - Precipitation of specific proteins by freeze-thawing of human saliva.
AB - Frozen saliva samples demonstrate a variable amount of precipitate on thawing
depending on the type of secretion [submandibular-sublingual (SML) greater than
parotid]. This precipitate has been resuspended using EDTA or removed by
centrifugation by some workers and others do not mention it. Yet others collect
the salivas into EDTA or centrifuge them before freezing. To determine the
adsorption of proteins to hydroxyapatite, prior treatment with EDTA would be
disadvantageous. The aim here was to determine if the protein pattern in parotid
and SML saliva as demonstrated by sodium dodecyl sulphate gel electrophoresis is
affected by the formation of precipitates. Portions of parotid and SML saliva
were thawed and treated in the following ways: (a) mixed vigorously with a vortex
mixer; (b) centrifuged to remove the precipitate; (c) mixed with EDTA (1 and 5
mmol final concentration for parotid and SML samples, respectively) to resuspend
the precipitate. The samples were loaded on to gradient (5-20%) SDS gels and,
following electrophoresis, the gels were stained with Coomassie brilliant blue R
250. The protein patterns obtained for (a) and (c) were the same. The centrifuged
samples demonstrated loss of a specific band of less than 14 kDa, although this
was less obvious in the parotid samples. The SML samples also showed a reduction
in other lower molecular-weight proteins. This study demonstrates that
precipitates in thawed frozen salivas contain specific proteins and that these
samples require careful handling to avoid any alteration in the overall protein
composition.
PMID- 10785525
TI - The relation between lead concentrations in human dental tissues and in blood.
AB - The purpose of this study was: (1) to measure the lead concentrations in various
parts of the teeth (enamel, dentine and circumpulpal dentine) and in blood from
individuals of a remote rural South African community; (2) to investigate any
correlation between the lead concentrations in these various dental tissues and
in blood; and (3) to estimate blood lead from the tooth lead concentrations
reported in other studies. Primary teeth and blood were collected from 48
children and analysed by graphite-furnace atomic absorptiometry. The following
median concentrations (expressed in mg/kg) of lead were found: blood, 0.025;
enamel, 0.25; dentine, 2.04; circumpulpal dentine, 6.71. The tooth lead
concentrations were similar to those from other studies from remote rural areas
but comparisons of blood lead were not possible in the absence of previous data.
Blood lead in other studies could be calculated from the ratios here reported.
PMID- 10785526
TI - Fluoride and magnesium concentrations in human dental calculus obtained from
Japanese and Chinese patients.
AB - Calculus deposited on a total of 68 permanent teeth from patients 30-60 years old
from Nagoya in Japan and Beijing in China was investigated. An abrasive
microsampling method was used to examine the fluoride (F) and magnesium (Mg)
distribution, using a fluoride ion-specific electrode and atomic absorption
spectrophotometry, respectively. F concentrations decreased from the surface
towards the interior of the calculus. Mg concentrations, however, gradually rose
towards the innermost surface adjacent to the tooth. In all parts of the depth
profiles, the average concentrations of both magnesium and fluoride were higher
in the Japanese than in the Chinese calculus. Towards the inner surface of the
calculus, F and Mg concentrations were also much higher in the Japanese than in
the Chinese group. A greater intake of sea foods and greater use of fluoride
dentifrices are possible reasons for the higher F and Mg concentrations in the
Japanese individuals.
PMID- 10785527
TI - Estimating relative motoneurone size in human masseter muscle.
AB - The representation of a motor unit in the macro-EMG (MacroRep) is the method of
choice for determining muscle-unit size in masseter. However, before using
MacroRep to infer motoneurone size, the relation between MacroRep amplitude and
motoneurone size needs to be established. This is particularly important in
masseter, where the diameter of the type II muscle fibres is smaller than that of
the type I fibres. This unusual situation may affect the cross-sectional area of
the muscle units innervated by motoneurones, disturbing the expected correlation
between the MacroRep and motoneurone size. This study used H-reflex latency as an
indicator of motoneurone size, and found a negative correlation between H-reflex
latency and MacroRep amplitude in all simultaneously firing motor-unit pairs
identified. Thus it is concluded that MacroRep amplitude provides a good estimate
of relative motoneurone size in masseter, within the limits specified in the
study.
PMID- 10785528
TI - The effectiveness of an educational intervention in changing nursing practice and
preventing catheter-related infection for patients receiving total parenteral
nutrition.
AB - Catheter-related infections are one of the most serious complications of TPN
therapy. Nurses have important responsibilities in the care of patients who are
receiving TPN. This quasi-experimental study was conducted for the purpose of
investigating the effectiveness of an educational intervention on changing
nursing practice and preventing catheter-related infections in patients receiving
total parenteral nutrition. The nurses' practice and the colonisation rate of
control and comparative group patients in the surgical clinics of Hacettepe
University Hospital (Turkey), and related variables were examined before and
after an educational intervention. The findings of the study indicate that the
intervention was successful in improving appropriate nursing practice, mean
scores of nurses' practices were 45.7 before and 66.5 after the intervention
(p<0.05). The rate of microorganism colonisation was also decreased but
statistical analysis demonstrated no association between nursing practices and
microorganism colonisation of catheter cultures.
PMID- 10785529
TI - Evaluation of a self-help leaflet in treatment of social difficulties following
facial disfigurement.
AB - Psychological difficulty, particularly in social situations, is widely reported
by disfigured people, but many receive no formal psychological treatment. This
study randomly allocated 106 facially disfigured people either to receive a self
help leaflet offering cognitive-behavioural guidance or not. Participants were
assessed pre-treatment and at 3 month follow-up. The untreated group then
received the leaflet. Participants in the leaflet group fared better than
controls on 3 of the 9 scales employed (Social Leisure [SAQ] (t=2.31, p=0.012),
HADS anxiety (t=2.22, p=0.015), HADS depression (t=1.83, p=0.036). There is
support for a cognitive-behavioural approach and the usefulness of self-help
instructions in addressing the social difficulties of facially disfigured people.
The approach merits further development and investigation.
PMID- 10785530
TI - Recognising advancing nursing practice: evidence from two observational studies.
AB - Debates over title, grades and relationships across the profession has tended to
dominate the literature in advancing nursing practice. Fewer research projects
have attempted to study the activities of nurses who are designated as
undertaking advancing nursing roles. One study evaluating Masters courses for
Clinical Nursing Practice and a second addressing the impact of the 'Scope of
Professional Practice' (United Kingdom Central Council for Nursing, Midwifery &
Health Visiting, 1992) document by this team of authors afforded these research
opportunities. In this paper empirical data from 'reflective' observation with 19
nurses (including midwives and health visitors) are presented to illustrate the
range and type of functions undertaken by a small group of practitioners
developing their practice. A number of characteristic features emerged.
Assessment of individual and group needs, positive motivation to constantly
improve practice, inter-disciplinary and cross agency working for planned change
and an ability to identify and prioritize service requirements were recognised in
these nurses' roles. Certain personal attributes were seen to be essential for
successful role development such as confidence, commitment and problem solving
powers combined with a positive working environment and supportive managers.
PMID- 10785531
TI - Fatigue in advanced cancer -- meaning before measurement?
AB - The fatigue experienced by patients with advanced cancer has received little
attention either in clinical practice or amongst researchers. To date, attention
has been directed at the fatigue experienced by patients receiving chemotherapy
or radiotherapy, with little being directed at the experiences of patients with
advanced cancer within the context of a rapidly declining health status. In light
of the paucity of information available to inform practice a study was undertaken
to explore the nature and impact of fatigue as experienced by 15 patients with
advanced cancer, a relative or friend of their choice, and health care
professionals involved with their care. The aims were threefold: (i) to gain
further understanding of this debilitating problem from divergent perspectives;
(ii) to identify potential intervention strategies to be evaluated in future
studies; and (iii) to attempt to inform palliative care research methodology
where previously poorly understood and inadequately articulated symptoms, such as
the fatigue of advanced cancer, are addressed. This paper focuses on issues
relating to the third of the three study aims. Seven men and eight women with a
variety of cancers, predominantly breast, ovarian, lung and prostate cancer were
interviewed. Demographic data, disease history, biochemical markers, weight,
nutritional status and medication profile were also recorded. Patients completed
visual analogue scales (VAS) recording perceptions of severity of fatigue and
pain, and distress caused by the fatigue, during the previous week. Each patient
also completed the Hospital Anxiety and Depression Scale (HADS). Following
verbatim transcription, taped interviews were subject to processes derived from
thematic content analysis, and Glaser and Strauss' constant comparative method.
Case note data, VAS and HADS were subject to descriptive statistics. Each
participant within this study articulated the importance of addressing the
struggle of finding meaning in something as inherently disabling as the fatigue
experienced. This led to the conclusion that valid and reliable measurement of
complex facets of terminal illness is dependent on extrapolating meaning before
undertaking measurement. This paper, drawing on patient focused data, sets out to
support that assertion.
PMID- 10785532
TI - The attitude of Japanese family caregivers toward the elderly with dementia.
AB - This research examined family caregivers' attitudes toward their elderly
relatives living with dementia. A convenience sample of fifty-nine Japanese
caregivers was used. Caregiver attitudes were investigated multi-dimensionally
(negative attitude, attitude of acceptance, and attitude of active interaction)
using a questionnaire developed specifically for this study. The dimensions did
not correlate with one another but were associated with different
caregiver/elderly characteristics: i.e., negative attitude with short stay use,
length of time caregivers and elderly relatives were living together and problem
behaviors; attitude of acceptance with sleeping pill use and the type of
relationship; and attitude of active interaction with dementia diagnosis. The
results have implications for nurses in facilitating constructive caregiver
attitudes.
PMID- 10785533
TI - University students' knowledge of AIDS.
AB - In this paper, a cross-sectional exploratory design is utilized for the purpose
of assessing the knowledge level of HIV/AIDS infection among a convenient sample
of university students. The sample consisted of 1013 students at the Bachelor's
level across the university faculties (Scientific, Medical and Humanities). Chi
square test of significance was utilized to examine crucial differences amongst
students regarding their self-assessed, as well as, general knowledge of
HIV/AIDS. The results indicated the presence of a "knowledge-deficit" problem
among the students in terms of what can or cannot transmit HIV/AIDS, taking into
consideration that 54% of the students stated that they "knew very little about
AIDS" and 14% said that they "never heard about AIDS". Moreover, the results
revealed the presence of certain misconceptions (myths) with regard to students'
general knowledge of HIV/AIDS. Significant differences in the students' level of
knowledge appear in relation with students' age, sex, academic level of
university education and the faculty they attend. The study explains these
results and comes out with appropriate recommendations, the most important of
which is the need for introducing a tailored-cut course on HIV/AIDS to be offered
to students as part of their study plans/curricula.
PMID- 10785534
TI - Nurses' participation and utilization of research in the Republic of China.
AB - A survey was done to improve understanding of nurses' participation in research
activities and their utilization of research for practice in one developing
country, the Republic of China. The sample for this 1996-1997 study was 382 staff
nurses and nurse managers. Using two instruments designed for the project it was
found that although research participation was low overall, 64% participated in
some research activities with data collection and presentation at national
conferences the most frequent activities. Nearly half the nurses had utilized
research to change practice in the previous three years. The main barriers to
utilization were lack of time and lack of staff. Role models, consultation and
guidance to locate useful research were the main types of needed assistance. The
findings provide direction for future training, education and managerial policy,
especially for nurses in developing countries, which account for 84% of the
world's population and 93% of the worldwide burden of disease.
PMID- 10785535
TI - Lesbian, gay and bisexual experiences within critical care nursing, 1988-1998: a
survey of the literature.
AB - The aim of this paper is to provide an analysis of the extent to which gay,
lesbian and bisexual service user experiences are represented within the critical
care literature. A survey of five well established critical care journals,
covering the period 1988-1998, was conducted in order to reveal the range of
themes addressed within them. The findings suggest that these groups are
invisible in this field of practice and consequently their particular concerns
have remained marginalised. The implications of this absence are far reaching,
potentially inhibiting nurses from establishing effective caring relationships
with either lesbians, gays or bisexuals and from identifying and developing
appropriate interventions for the care of these patients and their families.
PMID- 10785536
TI - Reconceptualising the outcomes of Continuing Professional Development.
AB - This paper considers the potential outcomes, both positive and negative, of
continuing professional development from the perspectives of practitioners and
managers. Following a consideration of the literature it draws upon data
collected during a 3-year evaluation of the English National Board Framework and
Higher Award to highlight divergent views and tensions within Continuing
Professional Development (CPD). Considerable discrepancies between practitioners
and managers emerge which raise a number of searching questions about the value
each group accords to continuing professional development. Based on the data a
new framework for conceptualizing the outcomes of CPD is presented which
fundamentally undermines a quasi-market approach.
PMID- 10785537
TI - Anandamide and other cannabimimetic fatty acid derivatives-foreword
PMID- 10785538
TI - Biochemistry and pharmacology of the endocannabinoids arachidonylethanolamide and
2-arachidonylglycerol.
AB - The purpose of this review is to discuss the cellular synthesis and inactivation
of two putative endogenous ligands of the cannabinoid receptor, N
arachidonylethanolamine (AEA) and 2-arachidonylglycerol (2-AG). Both ligands are
synthesized by neurons and brain tissue in response to increased intracellular
calcium concentrations. Both ligands are substrates for fatty acid amide
hydrolase (FAAH). Both AEA and 2-AG bind to the neuronal form of the cannabinoid
receptor (CB1). AEA binds the receptor with moderate affinity and has the
characteristics of a partial agonist, whereas, 2-AG binds with low affinity but
exhibits full efficacy. Two possible physiological roles of the endocannabinoids
and the CB1 receptor are discussed: the regulation of gestation and the
regulation of gastrointestinal motility.
PMID- 10785539
TI - Anandamide amidohydrolase (fatty acid amide hydrolase).
AB - Anandamide (N-arachidonoylethanolamine) loses its cannabimimetic activity when it
is hydrolyzed to arachidonic acid and ethanolamine by the catalysis of an enzyme
referred to as anandamide amidohydrolase or fatty acid amide hydrolase. Cravatt's
group and our group cloned cDNA of the enzyme from rat, human, mouse and pig, and
the primary structures revealed that the enzymes belong to an amidase family
characterized by the amidase signature sequence. The recombinant enzyme acted not
only as an amidase for anandamide and oleamide, but also as an esterase for 2
arachidonoylglycerol. The reversibility of the enzymatic anandamide hydrolysis
and synthesis was also confirmed with a purified recombinant enzyme. Several
fatty acid derivatives like methyl arachidonyl fluorophosphonate potently
inhibited the enzyme. The enzyme was distributed widely in mammalian organs such
as liver, small intestine and brain. However, the anandamide hydrolyzing enzyme
found in human megakaryoblastic cells was catalytically distinct from the
previously known enzyme.
PMID- 10785540
TI - Oxidative metabolism of anandamide.
AB - In addition to the well studied hydrolytic metabolism of anandamide, a number of
oxidative processes are also possible. Several routes somewhat analogous to the
metabolism of free arachidonic acid have been reported. These involve mediation
by various lipoxygenases and COX-2 and lead to ethanolamide analogs of the
prostaglandins and HETES. The physiological significance of these products is not
well understood at this time. There are also preliminary data suggesting a
pathway involving oxidation of the hydroxy group of anandamide to a putative
metabolite, N-arachidonyl glycine (AA-gly). This molecule displays activities in
experimental models that suggest that it may play a role in some of the
activities attributed to its precursor, anandamide.
PMID- 10785541
TI - Cannabimimetic fatty acid derivatives in cancer and inflammation.
AB - Evidence for the role of the cannabimimetic fatty acid derivatives (CFADs), i.e.
anandamide (arachidonoylethanolamide, AEA), 2-arachidonoylglycerol (2-AG) and
palmitoylethanolamide (PEA), in the control of inflammation and of the
proliferation of tumor cells is reviewed here. The biosynthesis of AEA, PEA, or 2
AG can be induced by stimulation with either Ca(2+) ionophores,
lipopolysaccharide, or platelet activating factor in macrophages, and by
ionomycin or antigen challenge in rat basophilic leukemia (RBL-2H3) cells (a
widely used model for mast cells). These cells also inactivate CFADs through re
uptake and/or hydrolysis and/or esterification processes. AEA and PEA modulate
cytokine and/or arachidonate release from macrophages in vitro, regulate
serotonin secretion from RBL-2H3 cells, and are analgesic in some animal models
of inflammatory pain. However, the involvement of endogenous CFADs and
cannabinoid CB(1) and CB(2) receptors in these effects is still controversial. In
human breast and prostate cancer cells, AEA and 2-AG, but not PEA, potently
inhibit prolactin and/or nerve growth factor (NGF)-induced cell proliferation.
Vanillyl-derivatives of anandamide, such as olvanil and arvanil, exhibit even
higher anti-proliferative activity. These effects are due to suppression of the
levels of the 100 kDa prolactin receptor or of the high affinity NGF receptors
(trk), are mediated by CB(1)-like cannabinoid receptors, and are enhanced by
other CFADs. Inhibition of adenylyl cyclase and activation of mitogen-activated
protein kinase underlie the anti-mitogenic actions of AEA. The possibility that
CFADs act as local inhibitors of the proliferation of human breast cancer is
discussed here.
PMID- 10785542
TI - Endogenous cannabinoid signaling and psychomotor disorders.
AB - The effects of cannabinoids on motor behaviors and cognitive functions are well
documented. The discovery of the CB1 cannabinoid receptor and the mapping of its
distribution in the central nervous system have provided a rationale to elucidate
the molecular and cellular mechanisms of cannabinoid actions. The identification
of naturally occurring ligands for these receptors, anandamide and 2
arachidonylglycerol, has prompted a large research effort aimed at investigating
the physiological role of the endogenous cannabinoid system, as well as its
potential use as a target for novel therapeutic interventions. This mini-review
discusses the participation of the endogenous cannabinoid system in the
regulation of motor behaviors, pointing out its possible involvement in the
pathophysiology of psychomotor disorders.
PMID- 10785544
TI - Editorial
PMID- 10785543
TI - Cardiovascular effects of endocannabinoids--the plot thickens.
AB - Cannabinoids, the bioactive ingredients of the marijuana plant, are best known
for their psychoactive properties, but they also influence other physiological
processes, such as cardiovascular variables. Endocannabinoids are recently
identified lipid mediators that act as natural ligands at cannabinoid receptors
and mimic most of the biological effects, including the cardiovascular actions,
of plant-derived cannabinoids. In experimental animals, the most prominent
component of the cardiovascular effects of cannabinoids is prolonged hypotension
and bradycardia. This review focuses on the possible mechanisms underlying these
effects. The emerging evidence suggesting that endocannabinoids may be involved
in the peripheral regulation of vascular tone under certain conditions is also
discussed.
PMID- 10785545
TI - (9-[4-acetyl-3-hydroxy-2-n-propylphenoxy) methyl]-3-(1H-tetrazol-5-yl)-4H-pyrido
[1,2-a] pyrimidin-4-one), AS-35, inhibits leukotriene synthesis.
AB - AS-35, (9-[4-acetyl-3-hydroxy-2-n-propylphenoxy) methyl]-3-(1H-tetrazol-5-yl)-4H
pyrido[1, 2-a] pyrimidin-4-one), was developed as a leukotriene (LT) receptor
antagonist, which also inhibited IgE-mediated release of leukotrienes (LTs). We
have investigated the action of AS-35 on the enzyme activities which are involved
in the synthesis of LTC(4) and LTB(4) (LT-synthesizing enzymes); cytosolic
phospholipase A(2) (cPLA(2)), 5-lipoxygenase (5-LO), leukotriene (LT)C(4)
synthase and LTA(4) hydrolase. AS-35 dose-dependently inhibited IgE- and A23187
stimulated production of LTC(4) by up to 71.5-84.8% and that of LTB(4) by 48.3
49.2% at 2. 5x10(-5) M. The assays for cPLA(2)(-), 5-LO-, LTC(4) synthase- and
LTA(4) hydrolase-activities revealed that the inhibition is attributable to
suppression of cPLA(2), 5-LO and LTC(4) synthase but not LTA(4) hydrolase. We
have also studied the action of AS-35 on the release of beta-hexosaminidase (beta
HEX) as a marker of preformed mediators. AS-35 had only weak inhibitory action on
the release of beta-HEX. The results indicate that anti-allergic action of AS-35
is predominantly attributable to its inhibition of LT synthesis by suppressing
three consecutive enzymes for LTC(4) synthesis.
PMID- 10785546
TI - Experimental evidence pointing to the bidirectional interaction between the
immune system and the thyroid axis.
AB - Among the many examples of neuroendocrine-immune system interactions the
relationship between the thyroid axis and the immune function has yet to be
clearly established. Here we studied the influence of thyroid hormones on the
course of an alloimmune response. Murine T(3) and T(4) levels were found to be
increased a few days after the immunization of mice with allogeneic lymphoid
cells. Besides in vivo treatment with T(4) was shown to increase alloantibody
titers during the early stages of alloimmunization and to enforce lymphoid
proliferation in vitro in a mixed lymphocyte reaction. Conversely, lowering
thyroid hormone seric levels by propylthiouracil treatment, negatively modulates
the humoral and cellular alloimmune responses. The evidence here points to the
existence of a bidirectional communication between both systems. The possibility
that the antigenic challenge would increase the thyroid gland activity thus
leading to a positive modulatory action upon the immune response is also
discussed.
PMID- 10785547
TI - Down-regulation by a new anti-inflammatory compound, FR167653, of differentiation
and maturation of human monocytes and bone marrow CD34+ cells to dendritic cells.
AB - FR167653 (1-[7-(4-fluorophenyl)-1,2,3,4-tetrahydro-8 (4-pyridyl) pyrazoro [5-1-c]
[1,2,4] triazin-2-yl]-2-phenylethanedion sulfate monohydrate), one of the
pyridinyl imidazoles, is an immunosuppressive agent which was developed to
inhibit proinflammatory cytokine production. We examined the effect of FR167653
on the differentiation and maturation phases of both human bone marrow-derived
dendritic cells (BM-DC) and blood monocyte-derived DC (Mo-DC). DC induced from
either BM-DC or Mo-DC progenitors in the presence of FR167653 had lower
expression of CD1a, CD83 and CD86 (B7.2). FR167653 also significantly suppressed
the ability of Mo-DC to produce both TNF-alpha and IL-1beta in response to LPS
stimulation. Mixed lymphocyte reaction (MLR) stimulation was significantly lower
in FR167653-treated Mo-DC than in control Mo-DC, although the suppressive effect
of FR167653 was much less on BM-DC. These results indicate novel
immunosuppressive properties of FR167653, which may be therapeutically useful in
controlling chronic immune and/or inflammatory diseases through down-regulation
of DC differentiation and maturation.
PMID- 10785548
TI - Allergen-induced bronchial eosinophilia in guinea-pigs is inhibited by both pre-
and post-induction cyclosporin-A treatments.
AB - Repeated treatment of sensitized guinea-pigs with cyclosporin-A (CS-A) before
aerosol allergen challenge is known to inhibit the subsequent bronchial
eosinophilia. It is not known, however, if the drug is also effective on
established/on-going bronchial eosinophilia. We have, therefore, studied the
effect of CS-A on allergen-induced eosinophil recruitment into the
bronchoalveolar lavage (BAL) fluid of guinea-pigs when given before or after
induction.Ovalbumin-immunized guinea-pigs were treated with CS-A (20 mg/kg
subcutaneously) or vehicle daily for varying periods before a single aerosol
allergen challenge. In animals in which bronchial eosinophilia was maintained
with repeated aerosol allergen challenge, CS-A or vehicle was given daily for
varying periods after the first allergen challenge. BAL and cell count were
performed 24 h after the last challenge. In vehicle-treated animals, a single
allergen challenge caused a 4-5 fold increase in the number of eosinophils in the
BAL fluid after 24 h, declining to baseline by 7 days. In repeatedly-challenged
animals, this response was sustained throughout. Eosinophil infiltration was
significantly inhibited when CS-A was given daily for 7-14 days, but not for 1 or
3 days, before allergen challenge. When given during an established/on-going
eosinophil infiltration, a significant inhibition was seen after administration
for 5 or 7 days, but not for 1 or 3 days.These results show that repeated CS-A
administration inhibits not only the induction of allergic bronchial eosinophilia
but also the maintenance of an established one. This may be relevant in the
treatment of allergic diseases, such as asthma, in which drug administration
often begins when eosinophilia is already established.
PMID- 10785549
TI - Restoration of splenic noradrenergic nerve fibers and immune reactivity in old
F344 rats: a comparison between L-deprenyl and L-desmethyldeprenyl.
AB - L-deprenyl, a monoamine oxidase-B inhibitor, partially reversed the age
associated decline in splenic sympathetic noradrenergic (NA) innervation and
immune reactivity in old male rats. The purpose of the present study was to
examine whether the effects of deprenyl on splenic sympathetic NA nerve fibers
and immune functions are mediated through a metabolite of deprenyl, L
desmethyldeprenyl. Old male F344 rats were treated with 0, 0.25, or 1.0 mg L-(-)
deprenyl/kg BW; 0.025, 0.25, or 1.0 mg L-(-)-desmethyldeprenyl/kg BW; and 1.0 mg
D-(+)-desmethyldeprenyl/kg BW i.p. daily for 8 weeks. The animals were sacrificed
after a 10-day drug wash-out period and the spleens were removed for
histofluorescence, immunocytochemistry, neurochemical, and immunological
analysis. The volume density of NA nerve fibers was increased in the spleens of
deprenyl- and L-desmethyldeprenyl-treated old rats. Con A-induced IFN-gamma
production by spleen cells was elevated in 1.0 mg/kg deprenyl- and L
desmethyldeprenyl-treated rats in comparison to saline- and D-desmethyldeprenyl
treated old rats. Deprenyl and desmethyldeprenyl treatment did not alter the
percentage of CD5+ T cells, but treatment with 1.0 mg/kg deprenyl and 0.025 mg/kg
L-desmethyldeprenyl prevented the decline in the percentage of sIgM(+)B cells in
the spleens of old rats. These results suggest that L-desmethyldeprenyl may be as
equipotent as deprenyl in preventing age-associated diminution in splenic
sympathetic NA innervation and immunocompetence.
PMID- 10785550
TI - Impaired estrogen priming of progesterone receptors in uterus of MRL/MP-lpr/lpr
mice, a model of systemic lupus erythematosus (SLE).
AB - Estrogens exacerbate the autoimmune disease SLE and progesterone is
immunoprotective. Estrogens increase synthesis of progesterone receptors (PR) and
it is hypothesized that this physiological balance may be impaired in SLE. To
test this, cytosolic PR were measured in hypothalamus, thymus and uterus from 6
week-old female ovariectomized BALB/c and MRL/MP-lpr/lpr mice 48 h after s.c.
injection of estradiol benzoate (3.2 microg/0.1 ml; OB) in peanut oil or 0.1 ml
peanut oil alone. PR were measured using [(3)H]ORG 2058, which does not bind to
corticosteroid-binding globulin (CBG), and bound and free ligand were separated
using minicolumns of Sephadex LH20 at 0 degrees C. PR were measured in cytosols
from hypothalamus and uterus of oil-treated BALB/c mice, but were undetectable in
thymus, whereas receptors were measurable in all three tissues of MRL mice. There
was a significantly greater priming effect of OB on PR in uterus of BALB/c mice,
but not in hypothalamus, and PR became detectable in thymus cytosols from BALB/c
mice. Also, the apparent affinity of the binding reaction between [(3)H]ORG 2058
and PR was significantly higher than those measured in other tissues in
hypothalamic cytosols of both strains. These results suggest that there is an
impairment of estrogen priming of progesterone receptors in uterus and perhaps
thymus of MRL mice.
PMID- 10785551
TI - The effects of allopurinol on immune function in normal BALB/c and SCID mice.
AB - To clarify the relationship between purine metabolism and immunity, the in vivo
immunosuppressive effects of allopurinol (AL), a xanthinoxidase (XO) inhibitor,
were studied using normal BALB/c and severe combined immunodeficient (SCID) mice.
Following AL administration for 14 weeks (long term), a decreased immune response
to ovalbumin (OVA) in the peripheral blood was observed in normal mice, which
might not be only due to direct B cell suppression but also due to suppression of
helper T cell function. In the SCID mice, there was a markedly late and reduced
recovery of surface immunoglobulin (sIg) positive cells, which are markers for
mature B lymphocytes, in the peripheral blood after AL administration. The total
immunoglobulin G (IgG) titers in the AL treated group were significantly lower
than in the control group 6 weeks after stem cell transfer, but increased until
there was no difference in the titers between the two groups at week 14. CD4
positive helper T cells and CD8 positive T cells were slow to recover, though
these gradually recovered to reach normal levels in the mature stage. These data
suggest that the administration of AL may modulate B cell and T cell responses in
OVA-immunized antibody formation. Furthermore, this study showed that AL could
influence immune functions during the pre-natal and developmental periods and
that its effects might differ according to the stages of maturity of the immune
cells.
PMID- 10785552
TI - Cefodizime enhances phagocytosis and intracellular killing of Staphylococcus
aureus but does not influence polymorphonuclear leukocytes response to fMLP
stimulation.
AB - The influence of Cefodizime (CDZ) on in vitro activity of polymorphonuclear
leukocytes (PMNL) from healthy subjects was assessed. Preincubation with CDZ
enhanced phagocytosis and intracellular killing of Staphylococcus aureus by PMNL.
Contrary to numerous clinical reports, no significant effect of CDZ preincubation
on PMNL response to n-formyl-methionyl-leucyl-phenylalanine was found with
respect to intracellular calcium changes, degranulation, hydrogen peroxide
production, and chemiluminescence. These results suggest that augmented
microbicidal activity of PMNL is not related to the enhanced production of
reactive oxygen species in healthy subjects.
PMID- 10785553
TI - The opioid-receptor-like 1 (ORL-1) as a potential target for new analgesics.
AB - Anew sequence, which encoded a novel G protein-coupled receptor, was disclosed by
two different groups, using the nucleic acid probes based on the delta opioid
receptor, first cloned in 1992. The new receptor, which Meunier called opioid
receptor-like 1 (ORL-1), was shown to share high homology with the opioid
receptors and therefore thought to be a potential target for new analgesics. In
this respect, the present review reports on the literature referring to ORL-1, to
its natural ligand (nociceptin or orphanin FQ) and to several synthetic analogues
recently described, both as agonists or antagonists at the receptor.
PMID- 10785554
TI - Quantum mechanical study of the intermediates formed following the reaction of
the histidine decarboxylase's substrate and inhibitors with coenzyme.
AB - Histidine decarboxylase catalyses the decarboxylation of l-histidine to histamine
using pyridoxal-5'-phosphate (PLP) as coenzyme. The PM3 quantum mechanical
conformation method of analysis and heat of formation calculation were carried
out for intermediates which are probably formed during the interaction of
histidine (substrate), (s)-alpha-methylhistidine, (s)-alpha-hydrazinohistidine,
(s)-alpha-fluoromethylhistidine and (s)-alpha-difluoromethylhistidine
(inhibitors) with PLP-dependent histidine decarboxylase from Morganella morganii.
The results suggest that the structures of the intermediates before and after
decarboxylation were found to exist in a conformation showing a planar
arrangement of the double bonds with the pyridoxylidene ring and the bond to the
carboxyl group being perpendicular to this plane. After decarboxylation, all the
double bonds are in the plane of the pyridoxylidene ring which facilitates the
electron displacement for the following protonation at C(alpha). The values of
the enthalpy for intermediates would increase the probability of their formation
in the enzyme's active site which are consistent with all available
stereochemical and mechanistic data.
PMID- 10785555
TI - Naphthazarin derivatives (IV): synthesis, inhibition of DNA topoisomerase I and
cytotoxicity of 2- or 6-acyl-5,8-dimethoxy-1, 4-naphthoquinones.
AB - Some 2- or 6-acyl-5,8-dimethoxy-1,4-naphthoquinone (DMNQ) derivatives were
synthesized and evaluated for inhibition of DNA topoisomerase I and cytotoxicity
against L1210 cells. Compared with 2-acyl-DMNQ derivatives, 6-acyl-DMNQ
compounds, bearing a higher electrophilic quinone moiety, showed a higher potency
in the inhibition of DNA topoisomerase I and the cytotoxicity, implying the
possible participation of electrophilic arylation in their bioactivities. Time
and temperature dependence of the enzyme inhibition suggests that the arylation
occurs irreversibly. Among the 6-acyl-DMNQ derivatives, the ones possessing an
acyl group of an intermediate size (C(5)-C(9)) showed higher potency in their
bioactivities than other derivatives. Furthermore, for the effective inhibition
of DNA topoisomerase I, the size of acyl moiety of 6-acylated derivatives seems
to be limited to < 12 carbon atoms.
PMID- 10785557
TI - Carbonic anhydrase inhibitors - part 78(#). Synthesis of water-soluble
sulfonamides incorporating beta-alanyl moieties, possessing long lasting
intraocular pressure lowering properties via the topical route.
AB - Reaction of 26 aromatic/heterocyclic sulfonamides containing amino, imino,
hydrazino or hydroxyl groups with N-tert-butyloxycarbonyl-beta-alanine (Boc-beta
ala; Boc = t-butoxycarbonyl) in the presence of carbodiimide derivatives
afforded, after removal of the protecting group, a series of water-soluble
compounds (as salts of strong acids, such as hydrochloric, trifluoroacetic or
trifluoromethane sulfonic). The new derivatives were assayed as inhibitors of the
zinc enzyme carbonic anhydrase (CA), and more precisely of three of its isozymes,
CA I, II (cytosolic forms) and IV (membrane-bound form), involved in important
physiological processes. Good inhibition was observed against all three isozymes,
but especially against CA II and CA IV (in the nanomolar range), the two isozymes
known to play a critical role in aqueous humour secretion within the ciliary
processes of the eye. Some of the best inhibitors synthesized were applied as 2%
aqueous solutions into the eyes of normotensive or glaucomatous albino rabbits,
when strong and long-lasting intraocular pressure (IOP) lowering was observed
with many of them. Thus, the amino acyl groups conferring water solubility to
these sulfonamide CA inhibitors, coupled with their strong enzyme inhibitory
properties and balanced lipid solubility seem to be the key factors for obtaining
compounds with effective topical antiglaucoma activity.
PMID- 10785556
TI - Protease inhibitors - part 5. Alkyl/arylsulfonyl- and arylsulfonylureido
/arylureido- glycine hydroxamate inhibitors of Clostridium histolyticum
collagenase.
AB - Reaction of alkyl/arylsulfonyl halides with glycine afforded a series of
derivatives which were first N-benzylated by treatment with benzyl chloride, and
then converted to the corresponding hydroxamic acids with hydroxylamine in the
presence of carbodiimide derivatives. Other derivatives were obtained by reaction
of N-benzyl-glycine with aryl isocyanates, arylsulfonyl isocyanates or benzoyl
isothiocyanate, followed by conversion of their COOH group into the CONHOH
moiety, as mentioned above. The 90 new compounds reported here were assayed as
inhibitors of the Clostridium histolyticum collagenase (EC 3.4.24.3), a zinc
enzyme which degrades triple helical regions of native collagen. The prepared
hydroxamate derivatives were generally 100-500 times more active than the
corresponding carboxylates. In the series of synthesized hydroxamates,
substitution patterns leading to the best inhibitors were those involving
perfluoroalkylsulfonyl- and substituted-arylsulfonyl moieties, such as
pentafluorophenylsulfonyl, 3- and 4-carboxyphenylsulfonyl-, 3-trifluoromethyl
phenylsulfonyl or 1- and 2-naphthyl among others. Thus, it seems that similarly
to the matrix metalloproteinase (MMP) hydroxamate inhibitors, Clostridium
histolyticum collagenase inhibitors should incorporate hydrophobic moieties at
the P(1') and P(2') sites, whereas the alpha-carbon substituent may be a small
and compact moiety (such as H, for the Gly derivatives reported here). Such
compounds might lead to the design of collagenase inhibitor-based drugs useful as
anti-cancer, anti-arthritis or anti-bacterial agents for the treatment of corneal
keratitis.
PMID- 10785558
TI - The low affinity PCP sites in the rat cerebellum not only bind TCP-like but also
BTCP-like structures.
AB - Congeners of the potent dopamine (DA) re-uptake inhibitor 1-[1-(2
benzo[b]thiophenyl)cyclohexyl]piperidine (BTCP) are unexpectedly able to bind in
the rat cerebellum, although this structure is devoid of dopaminergic nerve
endings. In line with previous studies the hypothesis that they bind to low
affinity PCP sites labelled with [3H]TCP in the rat cerebellum, even though they
do not bind to the high affinity PCP sites in the forebrain, was considered.
Analogues of 1-[1-(2-thiophenyl)cyclohexyl]piperidine (TCP) and BTCP with a
modified aromatic moiety and with O or S atoms substituted in the cyclohexyl ring
were prepared and tested in competition experiments both in rat forebrain and
cerebellum membranes labelled with [3H]TCP, and in rat striatum membranes
labelled with [3H]BTCP. Results indicated that BTCP and congeners could bind to
low affinity PCP sites labelled with [3H]TCP in the rat cerebellum with a
decrease of the selectivity for the DA transporter. On the contrary, some TCP
analogues displayed a very high selectivity for these low affinity sites; they
might be important pharmacological tools to elucidate the nature and function at
yet unknown of these sites.
PMID- 10785559
TI - Substituted 1,2,3-triazolo[1,5-a]quinazolines: synthesis and binding to
benzodiazepine and adenosine receptors.
AB - This paper reports the synthesis and evaluation of the biological affinity
towards benzodiazepine and A(1) and A(2A) adenosine receptors of some 3
ethoxycarbonyl or 3-phenyl-substituted 1,2, 3-triazolo[1,5-a]quinazolines.
Starting from the appropriate chloro-substituted phenylazides, the series of 7 or
8 chloro-substituted triazoloquinazolines were prepared. Nitration reactions of
the triazoloquinazoline ring and chlorination reactions of the hydroxyl group in
the 5 position of the same ring are also reported. By nucleophilic displacement
of halogen, the corresponding 5-amino derivatives and some analogous derivatives
bearing cyclohexylamino and p-toluidino substituents were obtained. The binding
assays showed a generalized decrease in the affinity towards the benzodiazepine
receptors and confirmed a moderate affinity towards the A(1) adenosine receptors
in comparison with the previously studied triazoloquinazoline derivatives.
PMID- 10785561
TI - Design, synthesis and antihistaminic (H(1)) activity of some condensed 3
aminopyrimidin-4(3H)-ones.
AB - Anovel series of condensed 3-amino-2-(substituted)methylpyrimidin-4(3H)-ones is
reported with potential H(1) receptor antagonistic activity. The IC(50) values
for 23 compounds were found to be in the micromolar range. Five lead compounds
(10c, e, g, r and t), when evaluated by the in vivo method were found to protect
guinea-pigs from the histamine induced asphyxia and antagonized histamine in a
competitive and reversible manner. With a pA(2) value of 8.7 and protection time
of 9.5 min (in vivo test), compound 10g was the most active amongst these five
compounds. The isosteric replacement of the side chain -NH- in series 1, by
oxygen and -NHSO(2)- functions, was undertaken to investigate the role of two
amino functions in the receptor binding. This isosteric replacement with -O- does
not affect the antihistaminic activity and the sedative potential of the series.
Preliminary molecular modelling studies indicate that the compounds with -NHSO(2)
in the side chain exhibit a closer fit with temelastine than their -O-
isosteres.
PMID- 10785562
TI - Synthesis and preliminary evaluation of new 5-pyrazolinone derivatives as
analgesic agents.
AB - New 4-(aroyloxyalkanoyl)-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one s (5) were
cyclized to 4-(2-aryl-5-unsubstituted/substituted oxazol-4-yl)-2,3-dimethyl-1
phenyl-3-pyrazolin-5-ones (6) employing the Davidson procedure. Preliminary
evaluation of analgesic activity revealed that the effect of 4-(2-phenyl-5
ethyloxazol-4-yl)-2, 3-dimethyl-1-phenyl-3-pyrazolin-5-one and 4-[2-(4
chlorophenyl)-5-ethyloxazol-4-yl]-2, 3-dimethyl-1-phenyl-3-pyrazoline-5-one on
acetic acid induced writhing was superior to that of antypyrine and aminopyrine.
4-[2-(4-Chlorophenyl)-5-methyloxazol-4-yl]-2, 3-dimethyl-1-phenyl-3-pyrazolin-5
one and 4-[2-(4-methoxyphenyl)-5-ethyloxazol-4-yl]-2, 3-dimethyl-1-phenyl-3
pyrazolin-5-one were more potent than aminopyrine, whereas 4-(2-phenyl-5
methyloxazol-4-yl)-2, 3-dimethyl-1-phenyl-3-pyrazolin-5-one and 4-[2-(4
methoxyphenyl)-5-methyl-oxazol-4-yl]-2, 3-dimethyl-1-phenyl-3-pyrazolin-5-one
were not as active (modified Koster's Test; 0.19-0.21 mmol.kg(-1)). None of the
selected entries showed inhibition of formaldehyde-induced paw oedema.
PMID- 10785560
TI - Synthesis and antitrypanosomal evaluation of E-isomers of 5-nitro-2-furaldehyde
and 5-nitrothiophene-2-carboxaldehyde semicarbazone derivatives. structure
activity relationships.
AB - Several novel semicarbazone derivatives were prepared from 5-nitro-2-furaldehyde
or 5-nitrothiophene-2-carboxaldehyde and semicarbazides bearing a spermidine
mimetic moiety. All derivatives presented the E-configuration, as determined by
NMR-NOE experiments. These compounds were tested in vitro as potential
antitrypanosomal agents, and some of them, together with the parent compounds, 5
nitro-2-furaldehyde and 5-nitrothiophene-2-carboxaldehyde semicarbazone
derivatives, were also evaluated in vivo using infected mice. Structure-activity
relationship studies were carried out using voltammetric response and lipophilic
hydrophilic balance as parameters. Two of the compounds (1 and 3) displayed the
highest in vivo activity. A correlation was found between lipophilic-hydrophilic
properties and trypanocidal activity, high R(M) values being associated with low
in vivo effects.
PMID- 10785563
TI - The classics: a tribute to the fiftieth anniversary of the randomized clinical
trial.
PMID- 10785564
TI - Co-morbidity data in outcomes research: are clinical data derived from
administrative databases a reliable alternative to chart review?
AB - Evaluation of co-morbidity data is essential in health outcomes research. Co
morbidity data derived from administrative databases has been criticized for
lacking the accuracy required for clinical research. We compared co-morbidity
data derived from a Canadian provincial hospitalization database with chart
review in 817 adults treated with a percutaneous coronary intervention at a
single tertiary care hospital between 1994 and 1995. While the administrative
database tended to under-estimate the prevalence of some co-morbid conditions,
the agreement between chart review and administrative data was good to very good
for most conditions. Asymptomatic conditions were noted to have lower levels of
agreement. Multivariate risk models for all-cause mortality constructed from both
data sources were almost identical, suggesting minimal misclassification. The
results indicate that clinical data abstracted from most Canadian hospitalization
databases can provide reliable information regarding baseline co-morbid
conditions believed to influence survival in a population undergoing percutaneous
coronary interventions.
PMID- 10785565
TI - Selection bias in studies of major depression using clinical subjects.
AB - Selection bias may systematically distort estimates deriving from psychiatric
studies using clinical subjects. Such bias may impact on cross-sectional studies
using samples of convenience and also on clinical case-control studies. The
objective of this report is to describe examples of such bias, and to identify
probably mechanisms underlying it. A series of cases was recruited from among
inpatients at a general hospital in Calgary, Canada. This case-series consisted
of consenting subjects with current episodes of major depression according to a
structured diagnostic interview. Comparison subjects consisted of non-depressed
(according to the structured interview) individuals admitted to the same units
and a sample of community subjects scoring negatively on a major depression
predictor. Bayesian calculations using ancillary census and national survey data
were used to estimate the selection probabilities underlying bias apparent in
several of the odds ratio estimates. Neither a cross-sectional analysis
incorporating all of the clinical subjects, the use of a community comparison
group nor a case-control analysis using a subset of the clinical subjects
resulted in valid estimation. This study confirms that the probability of
selection of clinical subjects can be conditionally dependent on diagnosis and
other variables in ways that create a substantial vulnerability to selection
bias.
PMID- 10785566
TI - Validity and reliability of the SF-36 Health Survey Questionnaire in patients
with coronary artery disease.
AB - The validity and reliability of the SF-36 has been studied in 185 patients
hospitalized with suspected ischemic cardiopathy, classified into four groups
(AMI, unstable angina, nonischemic cardiologies, and absence of cardiologies).
The validity of the construct has been analyzed by means of the association of
the SF-36 with sociodemographic and clinical variables, and with diagnostic
groups. The correlation of the subscales with GHQ-28 scores and the factorial
structure have been studied. Internal consistency was measured by Cronbach's
alpha and the item-internal consistency and item-discriminant validity. The
validation result was as expected, although the scores were significantly lower
in patients with unstable angina, only in the PF, VT, and GH subscales. The
correlations with the GHQ-28 were high for MH and VT. The internal consistency
was high (Cronbach's alpha 0.72-0.94). Factorial analysis identified eight
factors, with the "anxiety" component of subscale MH remaining as an independent
factor. These results suggest that the SF-36 is a useful scale for the
differentiated clinical forms of ischemic cardiopathy, with the additional
capability of reflecting the level of anxiety in these patients.
PMID- 10785567
TI - A meta-analysis of estrogen replacement therapy and risk of epithelial ovarian
cancer.
AB - Estrogen replacement therapy (ERT) has not been associated with epithelial
ovarian cancer in most reported epidemiologic studies that have looked for an
association. Some studies may have found weak statistically nonsignificant
associations because the number of cases or number of women who reported estrogen
use was small. We performed a meta-analysis of data from 15 case-control studies
that provided data on ERT and risk of epithelial ovarian cancer. The 15 combined
studies were statistically heterogeneous (chi(2) (14) = 26. 3, P < 0.05) in terms
of the effect they found. When we combined these studies using a random effects
model, we did not find a significant association of ERT with ovarian cancer (odds
ratio = 1.1, 95% confidence interval = 0.9-1.3). There was no clear evidence of a
dose-response relation with increasing duration of estrogen use in a subset of
five studies that reported estrogen use by duration (overall slope = 0.0012, 95%
confidence interval = -0.0055 to 0. 0080). The influences of statistical
outliers, study design (hospital or clinic controls vs. community controls), and
location (U.S. and Canada vs. Europe and Australia) were examined. The odds ratio
was 1.3 (95% confidence interval = 1.0-1.6) in the relatively homogeneous subset
of four U.S. case-control studies with community controls, but we cannot rule out
the possibility of uncontrolled confounding. The odds ratios for estrogen use for
other subgroups defined by geographic location and type of control group were not
significantly different from one.
PMID- 10785568
TI - Dealing with missing data in observational health care outcome analyses.
AB - Observational outcome analyses appear frequently in the health research
literature. For such analyses, clinical registries are preferred to
administrative databases. Missing data are a common problem in any clinical
registry, and pose a threat to the validity of observational outcomes analyses.
Faced with missing data in a new clinical registry, we compared three possible
responses: exclude cases with missing data; assume that the missing data
indicated absence of risk; or merge the clinical database with an existing
administrative database. The predictive model derived using the merged data
showed a higher C statistic (C = 0.770), better model goodness-of-fit as measured
in a decile-of-risk analysis, the largest gradient of risk across deciles (46.3),
and the largest decrease in deviance (-2 log likelihood = 406.2). The superior
performance of the enhanced data model supports the use of this "enhancement"
methodology and bears consideration when researchers are faced with nonrandom
missing data.
PMID- 10785569
TI - Hormone replacement therapy and endometrial cancer in Ontario, Canada.
AB - Estrogen therapy reduces the risk of osteoporosis and cardiovascular diseases but
is associated with an increased risk of endometrial cancer. We have assessed the
impact of a regimen of estrogen with progestogen on risk of endometrial cancer
for women 48 years and older. We conducted a case-control study in Ontario,
Canada, from 1994 to 1998 by interviewing registry-based cases (n = 512) and
population controls (n = 513) to obtain information on use of hormones and
dietary habits. Compared to non-users, the use of opposed hormone therapy in
sequential regimen for more than three years showed a borderline increase in risk
(OR = 1.49, 95% CI 0.93-2. 40), but this increase was much less than among women
on unopposed estrogen (OR = 4.12, 95% CI 2.21-7.71). Stronger associations were
observed when duration of sequential hormone use was examined as a continuous
variable (OR per three years of use = 1.21, 95% CI 1.03-1. 42). The effect of
opposed hormone therapy on endometrial cancer risk appears to vary both by usage
patterns and by patient characteristics of body weight and history of diabetes.
PMID- 10785570
TI - Dyslipidemia and abdominal obesity: an assessment in three general populations.
AB - Several studies show a relationship between abdominal obesity and cardiovascular
diseases, partially mediated through an altered metabolism of dyslipidemia. The
present study was aimed at testing the robustness of this association across
three contrasted populations and at assessing the performances of abdominal
obesity as a screening tool for dyslipidemia. Data were drawn from three
population health surveys recently conducted in two regions of a developed
country (Switzerland, mostly of Caucasian origin, n = 2650) and in a less
developed country (Seychelles, Indian Ocean, mostly of black descent, n = 806).
Dyslipidemia was defined as a ratio of total cholesterol to high-density
lipoprotein cholesterol (TC-HDL) greater than 5. Two anthropometric circumference
measurements, waist-to-hip ratio (WHR) and waist circumference (WC), were used to
define abdominal obesity either as WHR >/= 0.9 in men and WHR >/= 0.8 in women or
as WC >/= 94 cm and WC >/= 80 cm, respectively. A consistent direct association
between abdominal obesity and dyslipidemia (odds ratios varying from 1.85 to
4.56) was found in the three populations, independently of gender, age, body mass
index, blood pressure, and smoking. This consistency across ethnicities and
environments strengthens the hypothesis of a common etiopathological mechanism.
The sensitivity for detecting dyslipidemia was generally higher for abdominal
obesity, based on either WHR or WC, than for criteria based on the other risk
factors under study. In addition, the sensitivity was higher in the study
populations with a low prevalence of dyslipidemia (Swiss women and Seychellois of
both sexes) than in the others. These findings support that WHR and WC may be
useful as simple and inexpensive screening tools to select individuals eligible
for more sophisticated and costly serum lipid determinations, especially in
developing countries.
PMID- 10785571
TI - Predictive values of waist circumference for dyslipidemia, type 2 diabetes and
hypertension in overweight White, Black, and Hispanic American adults.
AB - Waist circumferences (WC) >/=102 cm for men and >/=88 cm for women have been
proposed by an expert panel as cut-points for identifying increased risk for the
development of obesity comorbidities for most adults. The aim of this
investigation was to examine the predictive values of these WC cut-points for
hypercholesterolemia, low concentration of high (HDL-C), and high concentration
of low (LDL-C) density lipoprotein cholesterol, hypertriglyceridemia, type 2
diabetes, and hypertension in overweight American adults. Data from NHANES III
were utilized for the analysis. Predictive abilities were determined by
calculating sensitivity, specificity, positive (PV+) and negative (PV-)
predictive values in overweight subjects with BMI 25-29.9 kg/m(2). Sensitivity of
WC cut-point was stronger for high LDL-C compared to other risk factors with the
highest values recorded in the 40-59 and 60-69 year age groups in men and women,
respectively. PV+ of WC cut-points for dyslipidemia, type 2 diabetes, and
hypertension were low in men compared to women. PV+ tended to increase with age,
from 19-39, 40-59 to 60-90 year age groups in Whites, Blacks, and Hispanic men.
In men, the highest PV+ were recorded for hypertriglyceridemia in the 60-90 years
old groups, with values of 71.6%, 52.5%, and 43.3% in Whites, Blacks, and
Hispanics, respectively. The CVD risk factor associated with the highest PV+ in
women was diabetes with values of 97.2% in Whites and 88.9% in Blacks, and
hypertriglyceridemia with a value of 93.8% in the 17-39 year age group in
Hispanics. Among Black men 40-59 years of age, only 32% of a population of
overweight hypertensives were detected by the WC cut-points, and among Black
women, 40-59 years of age, only 54% were detected. Given the low sensitivity of
these cut-points for detecting hypertension, one of the major co-morbidities of
obesity, these cut-points failed to provide adequate evidence for the use of WC
in determining or evaluating patients as to co-morbid states. We recommend
further studies to determine a set of specific cut-points associated with
increased risk of CVD in different population groups.
PMID- 10785572
TI - Estimation of extra hospital stay attributable to nosocomial infections:
heterogeneity and timing of events.
AB - Infections acquired in hospital are likely to affect the duration of
hospitalization. Suitable statistical methods for estimating the extra days spent
in hospital due to nosocomial infections should allow modeling of the
heterogeneity of the patient population and the timing of events, as failure to
account for important covariates and failure to model adequately the timing of
events may lead to biased results. Three approaches have been used in the past to
estimate the extra stay: a comparison of duration of stay of infected and
uninfected patients, matching of infected and uninfected patients with respect to
potentially important determinants of the length of hospital stay, and matching
for time-to-infection in addition to the other factors. While these approaches
can allow for the heterogeneity of the patient population, none takes sufficient
account of the real timing of events and may overestimate the effect of
nosocomial infections. We explored the statistical methods available for
analyzing time-to-event data and derived alternative methods to estimate the
extra stay that appropriately account for heterogeneity and timing. Data from two
prospective cohort studies on postoperative wound infection and on nosocomial
pneumonia showed that the two-group comparison yields the highest estimates of
extra stay (21 and 14 extra days), while matching for confounders and time
reduced the estimates to 11 and 8 extra days; our methods yield even lower
results (10-12 and 3-4 extra days).
PMID- 10785573
TI - Coronary heart disease surveillance: field application of an epidemiologic
algorithm.
AB - This report describes the performance of a surveillance system and computerized
algorithm for the assignment of definite or probable hospitalized cardiac events
for large epidemiologic studies. The algorithm, developed by the Coordinating
Committee for Community Demonstration Studies (CCCDS), evolved from the Gillum
criteria, and included selected ICD-9-CM codes including codes 410 through 414
for discharge record screening, plus creatine kinase. For the small percentage of
cases in which enzyme analysis was inconclusive (8%), presence of pain and/or
Minnesota-coded electrocardiograms were included to define the outcome. All data
items were easily obtained from medical records by trained lay record abstractors
and required no interpretation. From January 1980 through December 1991, 21,183
medical records were screened for ICD-9-CM codes 410 through 414. Of all 410 to
411 ICD-9-CM codes (n = 9026), 36.9% (n = 3220) were classified as definite
cardiac events and 10.6% (n = 1057) as probable events. Of all 412 through 414
codes (n = 9070), only 1.8% (n = 227) were classified as definite cardiac events
and 5.4% (n = 716) as probable events. The epidemiologic diagnostic algorithm
presented in this article used computerized data to assign diagnoses in a
standard, objective manner, and was a lower cost alternative to classification of
cardiac events on the basis of clinical review and/or more complex record
abstraction approaches.
PMID- 10785574
TI - Trends in selected biological risk factors for cardiovascular diseases in the
Danish MONICA population, 1982-1992.
AB - Data from 6695 men and women of ages 30, 40, 50, and 60 years, examined in the
Danish WHO MONICA surveys in 1982-84, in 1986-87, and in 1991-92, were analyzed
to estimate secular trends in body height and weight, blood pressure, and serum
total, HDL-, and LDL-cholesterol, and triglyceride. Body height increased 0.1%
per year, and body mass index increased 0.4% per year in women. Diastolic blood
pressure increased 0.4% per year in women and 0.6% per year in 60-year-old men.
HDL cholesterol declined 0.4% per year. Body mass indices in men, diastolic blood
pressures in men <60 years of age, systolic blood pressures, total- and LDL
cholesterol and triglyceride did not change. The levels of biological risk
factors in the Danish WHO MONICA study population did not show trends during the
1980s that help explain the declining incidence of myocardial infarction in the
population.
PMID- 10785575
TI - Verbal fluency and psychiatric symptoms in geriatric schizophrenia.
AB - Previous studies have demonstrated that negative symptoms are regulated by
frontal brain regions. We were interested in the relationship between psychiatric
symptoms and performance on a verbal fluency (VF) battery in a population of
elderly schizophrenic subjects. Thirty-five elderly schizophrenic subjects were
administered a neuropsychological battery which included verbal fluency
performance and Positive and Negative Symptom Scale (PANSS). Results showed
negative symptoms to be strongly correlated with performance on tasks of VF,
which may suggest that negative symptomatology in schizophrenia is related to
prefrontal cortical activity.
PMID- 10785576
TI - Quantitative characterization of eye tracking dysfunction in schizophrenia.
AB - The purpose of this study was to characterize the nature of the processes that
are involved in eye tracking dysfunction (ETD). We identified a combination of
quantitative measures that best distinguished qualitatively normal eye tracking
from qualitatively abnormal eye tracking, using discriminant analysis.
Discriminant scores distinguished schizophrenics with ETD from both
schizophrenics with normal eye tracking and normal controls, but did not
distinguish schizophrenics with normal eye tracking from normal controls,
underscoring the heterogeneity of schizophrenic patients with respect to eye
tracking. The results of the discriminant analysis indicated that ETD is a
multivariate process involving a primary impairment in the smooth pursuit system
characterized by increased catch-up saccades and reduced gain, and, secondarily,
disinhibition of intrusive saccades, especially square-wave jerks. Quantitative
characterization of ETD makes it possible to consider eye tracking as a
quantitative trait in genetic investigations of a multidimensional phenotype.
PMID- 10785577
TI - Event-related potentials and thought disorder in schizophrenia.
AB - We examined the relationship between event-related potentials and thought
disorder in schizophrenia. The subjects were 29 chronic schizophrenic patients.
Thought disorder was assessed using the Comprehensive Index of Positive Thought
Disorder developed by Harrow and colleagues (Harrow and Quinlan, 1985; Marengo et
al., 1986). Auditory event-related potentials were recorded during a standard
oddball task. The P300 amplitude correlated negatively with the severity of the
thought disorder. The P300 amplitude in the patients with thought disorder was
significantly smaller than in the patients without thought disorder. These
results suggest that a reduction in P300 amplitude is associated with a
fundamental impairment of information processing in schizophrenic patients.
PMID- 10785579
TI - Neural correlates of memory organization deficits in schizophrenia. A single
photon emission computed tomography study with 99mTc-ethyl-cysteinate dimer
during a verbal learning task.
AB - Regional cerebral blood flow (rCBF) during a verbal learning task was measured
using 99mTc-ethyl-cysteinate dimer and single photon emission computed tomography
in 10 patients with schizophrenia and nine normal controls. Verbal repetition was
used as a control task. The schizophrenic patients showed failure to
spontaneously utilize implicit category information to learn the word lists. In
the normal controls, rCBF in the left inferior frontal and left anterior
cingulate regions was significantly increased during the verbal learning task,
compared with the verbal repetition task. In contrast, there was no significant
frontal lobe activation by the verbal learning in the schizophrenic patients. The
patients had lower rCBF during the verbal learning task than the controls in the
bilateral inferior frontal, left anterior cingulate, right superior frontal, and
bilateral middle frontal regions. Activation in the left inferior frontal region
was significantly positively correlated with categorical clustering in the task
in the controls, but no such correlation was found in the patients. These results
indicate that memory organization deficits in schizophrenia may be related to
dysfunction in the prefrontal areas, especially in the left inferior frontal
region.
PMID- 10785578
TI - Shape and size of the corpus callosum in schizophrenia and schizotypal
personality disorder.
AB - The size and shape of the corpus callosum were assessed on sagittal section
magnetic resonance images in 27 patients with schizophrenia, 13 patients with
schizotypal personality disorder (SPD), and 30 healthy volunteers. High
resolution 1.2mm axial SPGR images were acquired and resectioned so that the
sagittal plane passed through the anterior and posterior commissures and was
parallel to the interhemispheric fissure. The corpus callosum and the whole brain
were traced on midsagittal section slices of each brain, and the callosum was
divided into 30 anteroposterior sectors. Pixel-by-pixel chi-square and thin-plate
spline analyses were used to assess between-group shape differences. Size of the
corpus callosum was smaller anteriorly in the genu of the corpus callosum and
posteriorly in the splenium in schizophrenic patients than in normal controls.
The genu of the corpus callosum was larger in SPD patients than in schizophrenic
patients or normal controls. The posterior corpus callosum was largest in normal
controls, smaller in SPD patients, and smallest in schizophrenic patients. Shape
analysis was consistent with these size comparisons, and suggested a downward
bowing of the corpus callosum in schizophrenic and SPD patients. SPD patients
also had a region of the callosum just posterior to the genu that was narrower
than in the other two groups. The decreases in corpus callosal size in
schizophrenia varied directly with length of illness, perhaps indicative of a
progressive process. The patient-control differences in callosal size and shape
are consistent with a hypothesis of decreased connectivity between the left and
the right hemispheres in schizophrenia and SPD.
PMID- 10785580
TI - Prevalence of extrapyramidal syndromes in psychiatric inpatients and the
relationship of clozapine treatment to tardive dyskinesia.
AB - In 200 inpatients on regular neuroleptics, point prevalence of extrapyramidal
syndromes, including Parkinson syndrome, akathisia and tardive dyskinesia (TD),
was studied and found to be 20, 11 and 22%, respectively. A total of 46 patients
have currently, and for a longer time, (average about 3years, median over 1year)
been treated with clozapine, and 127 with typical neuroleptics (NLs). Comparing
both groups, higher TD scores were found in the clozapine sample. Investigating
the influence of a set of seven clinical variables on the TD score with the help
of multiple regression analysis, the influence of the treatment modality
disappeared, whereas the age proved to be the only significant variable. Studying
the role of past clozapine therapy in patients currently on typical NLs and
comparing 10 matched pairs of chronic patients with and without TD in whom a
complete life-time cumulative dose of NLs was identified, a relationship between
TD and length of current typical NL therapy and life-time typical NL dosage could
be demonstrated. On the whole, long-term relatively extensive use of clozapine
has not markedly reduced the prevalence of extrapyramidal syndromes in our
psychiatric inpatient population. In particular, we failed to demonstrate a
beneficial effect of clozapine on prevalence of TD. There are certainly patients
who suffer from TD in spite of a long-term intensive clozapine treatment.
PMID- 10785581
TI - Stability of the five-factor structure of the Positive and Negative Syndrome
Scale (PANSS).
AB - The main objective of the study was to verify the stability of the five-factor
(negative. positive, excitation, depression and cognitive) structure of the
Positive and Negative Syndrome Scale (PANSS). The psychometric properties
(validity and reliability) of the forced five-factor structure of the PANSS were
explored in two different populations of schizophrenic patients: one in relapse
and the other in the chronic phase of the disease. Three hundred and forty-two
schizophrenic patients according to DSM-III-R criteria were involved. One hundred
and eighteen (34.5%) patients were in relapse, and 224 (65.5%) were in the
chronic phase. The forced five-factor principal-component analysis explained
64.3% of the total variance in the relapse patients and 62.1% in the chronic
patients. The order of the factors was reversed for the depression and excitation
factors in chronic patients compared with patients in relapse. The internal
consistency of this five-factor structure was good (Cronbach's alpha >0.70) in
the relapse and chronic patients, except for the cognitive factor. In conclusion.
five dimensions (negative, positive, excitation, depression and cognition) are
necessary to account for the various clinical aspects of schizophrenia described
by PANSS in relapse and chronic schizophrenic patients.
PMID- 10785582
TI - Reliability and validity of a new Medication Adherence Rating Scale (MARS) for
the psychoses.
AB - Medication compliance is one of the foremost problems affecting neuroleptic
efficacy in psychiatric patients. To date, compliancy has most commonly been
assessed with the Drug Attitude Inventory (DAI) developed by Hogan et al. (Hogan,
T.P., Awad, A.G., Eastwood, R., 1983. A self-report scale predictive of drug
compliance in schizophrenics: reliability and discriminative validity. Psychol.
Med. 13, 177-183). The present study identified several deficiencies in the DAI.
Using the partial credit version of the Item Response Theory measurement model,
the DAI was refined with the aim of greater validity and clinical utility. The
new inventory was administered to 66 patients, the majority of whom were
diagnosed with schizophrenia. When available, lithium levels and carer ratings of
compliance were also recorded and used to verify compliancy. The new inventory
appears to be a valid and reliable measure of compliancy for psychoactive
medications.
PMID- 10785583
TI - Xanomeline, an M(1)/M(4) preferring muscarinic cholinergic receptor agonist,
produces antipsychotic-like activity in rats and mice.
AB - Xanomeline is an M(1)/M(4) preferring muscarinic receptor agonist which decreased
psychotic behaviors in patients with Alzheimer's disease, suggesting that
xanomeline might be useful in the treatment of psychotic symptoms in patients
with schizophrenia. The purpose of the present studies was, therefore, to compare
the pharmacologic profile of xanomeline with that of known antipsychotic drugs.
Electrophysiologically, xanomeline, after both acute and chronic administration
in rats, inhibited A10 but not A9 dopamine cells in a manner which was blocked by
the muscarinic receptor antagonist scopolamine. Behaviorally, xanomeline, like
haloperidol, clozapine and olanzapine, blocked dopamine agonist-induced turning
in unilateral 6-hydroxydopamine-lesioned rats, as well as apomorphine-induced
climbing in mice. However, unlike the dopamine antagonist antipsychotic
haloperidol, xanomeline did not produce catalepsy in rats. Moreover, xanomeline,
like haloperidol, clozapine and olanzapine, inhibited conditioned avoidance
responding in rats, an effect which also was blocked by scopolamine. The present
results thus demonstrate that xanomeline has a pharmacologic profile which is
similar to that of the atypical antipsychotics clozapine and olanzapine, thus
indicating that xanomeline has the potential to be a novel approach in the
treatment of psychotic symptoms in patients with schizophrenia.
PMID- 10785584
TI - Single agents should be administered in preference to combination chemotherapy
for the treatment of patients over 70 years of age with advanced ovarian
carcinoma.
PMID- 10785585
TI - Quality of life evaluation in oncological clinical trials - the EORTC model. The
EORTC Quality of Life Study Group.
AB - The European Organization for Research and Treatment of Cancer (EORTC) has taken
a leading role in the development of the methodology of quality of life (QL)
measurement. In the EORTC Quality of Life Study Group (QLSG) valid instruments to
assess QL in a general manner and disease-specific modules have been developed to
be used in oncological clinical trials. Statistical and methodological aspects of
QL research are discussed. The application of QL assessments in clinical trials
represents a subsequent challenge. To improve the practice of QL assessment in
clinical trials an 'EORTC model' has been developed. This model requires the
collaboration of liaison persons, the EORTC Cooperative Tumour Groups and the
EORTC Data Centre Quality of Life Unit (QL Unit). Cooperation between these
parties, protocol development and advantages and concerns of the model are
mentioned in this paper. Finally, suggestions for improvement are proposed.
PMID- 10785586
TI - Telemedicine and its impact on cancer management.
AB - The latest dramatic progress in the technologies of the computer industry is
likely to increasingly influence the oncologist's daily routine. Besides well
known and established telemedical services such as videoconferencing, the most
influential trends are the spread of digital hospital infrastructures with
unlimited, secured access to all relevant patient information. This article seeks
to summarise the most imminent influences of telemedical developments on the
future of the oncologist: the effects of telemedical services and electronic
infrastructures on clinical workflow and on medical quality management. In
addition, the history of telemedicine, recent technologies and the performance of
electronic patient records are described.
PMID- 10785587
TI - Summary measures and statistics in the analysis of quality of life data: an
example from an EORTC-NCIC-SAKK locally advanced breast cancer study.
AB - Quality of Life (QL) is now included as an endpoint in many phase III cancer
clinical trials. Numerous statistical techniques have been presented in the
literature to analyse QL data but there is still no agreement as to what is the
optimal approach of analysis. In this paper we, therefore, present and compare
various techniques which have all appeared in the literature and which may be
globally described as summary measures and summary statistics. These techniques
are illustrated using data from an EORTC clinical trial in locally advanced
breast cancer (EORTC trial 10921). It is also explained in this paper how and
when these techniques may be used in other cancer settings. For EORTC trial
10921, it is shown that by choosing different techniques different conclusions
may be drawn concerning the QL outcome. This highlights the importance of
choosing an appropriate primary statistical method and for describing it a priori
in the protocol and analysis plan. In this paper, we show the importance of
performing sensitivity or supportive analysis to support conclusions drawn from
the primary analysis.
PMID- 10785588
TI - Effective tamoxifen therapy of breast cancer involves both antiproliferative and
pro-apoptotic changes.
AB - Despite knowledge of oestrogen receptor status, it is not always possible to
predict which breast cancers will respond to tamoxifen. We have previously
reported that decreased expression of Bcl-2 and/or Ki-S1 were associated with
tumour response to neo-adjuvant tamoxifen in 50 elderly women with oestrogen
receptor (ER)-positive breast cancer. In this study, we confirm that the
expression of Bcl-2 and Ki-S1 are surrogates for the frequency of apoptosis and
mitosis respectively, within these untreated breast cancers, with an inverse
relationship between Bcl-2 expression and the apoptotic index (P<0.05), and a
positive relationship between Ki-S1 expression and the mitotic index (P<0.01).
However, after 3 months' tamoxifen treatment these relationships were no longer
apparent. Moreover, amongst the 27 tumours in which Bcl-2 expression was reduced
during the 3 months' therapy, there was a significant correlation between the
response to therapy and the increase in apoptosis (P<0.05), whereas in those
tumours in which Bcl-2 did not fall with therapy, there was a significant
correlation between response and the decrease in mitosis (P<0.05). These data
suggest there are at least two mechanisms for effective tamoxifen therapy:
increased apoptosis as a consequence of reduced Bcl-2 expression, and decreased
proliferation.
PMID- 10785589
TI - An analysis of potential factors allowing an individual prediction of cisplatin
induced anaemia.
AB - Severe cisplatin (CP)-induced anaemia significantly impairs the patient's quality
of life. Prevention based on erythropoietin (EPO) administration would be cost
effective providing that individual predictive factors of anaemia are identified.
The aim of the present study was to identify parameters able to predict the
occurrence of CP-related anaemia. This prospective study was conducted on 40 head
and neck cancer patients receiving a CP (100 mg/m(2), intravenous (i. v.) on day
1) - 5-fluorouracil (5-FU, 1 g/m(2)/dx5 days by continuous infusion) induction
chemotherapy. Three cycles were given at 3-weekly intervals. Platinum
pharmacokinetics (total and ultrafilterable plasma platinum concentration
measured 16 h after CP administration) and 5-FU pharmacokinetics (full-cycle
plasma area under the curve, (AUC(0-105h)30 g/l) occurred in 15 patients (38%)
and 3 of them also received a blood transfusion. Patient age, 5-FU AUC(0-105h)
and total platinum concentration were unrelated to Hb loss. In contrast,
ultrafilterable (UF) platinum concentration was significantly correlated to Hb
loss: the higher the UF platinum concentration, the greater the Hb loss
(P=0.015). A discriminant analysis allowed a cut-off value for UF platinum to be
proposed to identify patients developing significant loss of Hb: 91% of patients
exhibiting a UF platinum concentration above 50 ng/ml developed significant loss
of Hb in contrast to 18% in the group of patients with a UF platinum
concentration below 50 ng/ml (odds ratio (95% confidence interval, CI) of 46 (4.7
446)). In conclusion, the present platinum pharmacokinetic survey may be proposed
as a valuable approach to identify patients at risk for developing severe
anaemia.
PMID- 10785590
TI - Experience in qualitative and quantitative FDG PET in follow-up of patients with
suspected recurrence from head and neck cancer.
AB - We evaluated positron emission tomography (PET) with 2-[fluorine-18]fluoro-2
deoxy-D-glucose (FDG) in the detection of recurrent head and neck cancer, and
compared visual and quantitative interpretation of PET images for their accuracy
in the identification of tumour recurrence. Sixty-two FDG PET studies were
performed in 56 patients having a total of 81 lesions, which were clinically
suspected for recurrent carcinoma of the head and neck. The PET images were
interpreted visually, and tracer uptake was quantitated as the standardised
uptake value adjusted to body weight (SUV). Sensitivity of visual interpretation
of the PET images for the presence of malignancy ranged from 84 to 95%, and
specificity from 84 to 93%, respectively, depending on the selected scheme for
grading of the lesions. Malignant lesions accumulated significantly more FDG than
the benign ones (the median SUVs were 6.8 and 3.3, respectively, P<0.001).
However, there was a wide overlap of the FDG uptake values between these two
groups. Hence, the highest accuracy of quantitative analysis in correct
identification of tumour recurrence (75% at Receiver Operating Curve analysis)
was inferior to that of visual analysis (89%). FDG PET is feasible for the
detection of recurrent head and neck cancer. Although quantitation of FDG uptake
using SUV shows significantly higher tracer concentrations for malignant than
benign lesions, the wide overlap of individual SUVs between these two groups is a
serious concern in diagnostic evaluation. Therefore, in clinical practice it may
be preferable to identify the presence of tumour recurrence within this patient
group by qualitative interpretation of the PET images.
PMID- 10785591
TI - Intra-operative irradiation (IORT) for primary advanced and recurrent rectal
cancer. a need for randomised studies.
AB - The aim of this study was to determine the impact of intra-operative irradiation
(IORT) combined with pre-operative external beam irradiation (EBRT) and surgical
resection in patients with locally advanced primary or recurrent rectal cancer.
64 patients with locally advanced primary cancer and 104 with recurrence had EBRT
(46-50 Gy) before surgery. 80 patients received IORT (median dose 15 Gy energy 12
MeV). 80 patients had R0 resections, 47 R1 and 41 R2 resections. More R1
resections were performed in the IORT group, more R0 and R2 resections in the non
IORT group. Median follow-up was around 22 months. 146 patients were resected, 22
had exploratory laparotomy. The cumulative overall survival was similar for both
the IORT and non-IORT groups. 5-year survival for primary cancers was 48% versus
28% for recurrences. No R2 resections survived 3.5 years. 5-year-survival for R0
resections was nearly 60% and around 30% for R1 resections. The survival curves
of the patients given and not given IORT treatment was not statistically
different when R0, R1 and R2 resections were analysed separately. IORT did not
seem to influence the local recurrence rate when R0 and R1 resections were
analysed separately or in a multivariate analysis. The IORT and non-IORT groups
were not identical with regard to type of cancer and R-stage. Still the lack of
an identifiable impact of IORT suggests that there is a need for randomised
studies of the IORT effect.
PMID- 10785592
TI - Five-year results in Ewing's sarcoma. The Scandinavian Sarcoma Group experience
with the SSG IX protocol.
AB - The first Scandinavian protocol for Ewing's sarcoma, SSG IV, resulted in a local
control rate of 74% and 5-year metastasis-free survival (MFS) of 43%. The second
protocol, SSG IX, was started in order to improve upon these results. It featured
four chemotherapy cycles, each consisting of two courses of VAI (vincristine,
doxorubicin, ifosfamide) alternating with one course of PAI (cisplatin,
doxorubicin, ifosfamide) at 3-weekly intervals. Total treatment time was 35
weeks. Local therapy was given at week 9. Inoperable or non-radically operated
patients received hyperfractionated accelerated radiotherapy 1.5 Gy twice daily
between chemotherapy courses to a total dose of 42-60 Gy, depending on surgical
radicality and tumour localisation. 88 patients were included (58 male, 30
female, mean age 20 years; range 5-65 years). The tumour (73 M0 and 15 M1) was
located centrally in 31 patients (35%), in the extremities in 34 (39%) and other
sites in 23 (26%) of cases. The median size of tumour was 10 cm (range 2-23),
soft tissue was invaded in 87%. Surgery was the local therapy for 60 (68%)
patients: amputation in 8 and local excision in 52. The surgical margins were
wide in 35 patients, marginal in 14 and intralesional in 3. Radiotherapy was
given to 17 non-radically operated patients postoperatively and to 28 patients
with inoperable tumours primarily. Histological responses were evaluated in 52
patients. 9 local recurrences were observed (10%). Distant metastases developed
in 24 M0 patients (33%). The estimated 5-year MFS was 58% and overall survival
(OS) 70% for M0 and 27% and 28% for M1 patients, respectively. Survival was
favourable in patients with non-metastatic extremity tumours (90%) and tumours
operated with wide margins (90%). Patients with a total necrosis after
chemotherapy had a better OS than those with a partial or poor response
(P=0.003). The toxicity (World Health Organisation) was acceptable
(gastrointestinal G1-2; haematological G3-4). The SSG IX protocol gave better
local control and survival rates than the SSG IV. Whether this is due to a higher
therapeutic efficacy of the present protocol cannot be ascertained in this
comparison with a historical control.
PMID- 10785593
TI - Incidence of P-glycoprotein overexpression and multidrug resistance (MDR)
reversal in adult soft tissue sarcoma.
AB - Multidrug resistance (MDR) is a widespread problem in the treatment of neoplastic
diseases and may limit the effectiveness of treatment of adult soft tissue
sarcomas (STS). We examined the levels of expression of the MDR marker P
glycoprotein (Pgp) in fresh, surgical material and matched paraffin-embedded
tissue using MRK-16 and JSB-1 monoclonal antibodies. Using fresh tumour material
in short-term culture an assessment of doxorubicin sensitivity (MTT assay) and
MDR modulation using PSC-833 in daunorubicin (DNR) accumulation experiments (FACS
analysis) was carried out. 44 patients were studied at various disease stages
with a mean follow-up duration of 487 days (range: 45-1095 days).
Immunocytochemistry and immunohistochemistry showed 62% and 58%, respectively, of
STS samples were positive for Pgp. Patients showing negative Pgp expression had a
median survival of 544 days versus 431 days for Pgp-positive patients (P=0.311),
with disease-free survival medians of 508 and 355 days, respectively (P=0.203).
In vitro doxorubicin sensitivity was not informative in this respect and there
was no apparent relationship between this and Pgp expression. Eleven out of 29
samples evaluated for MDR modulation showed enhanced tumour cell DNR
accumulation. However, the effects of PSC-833 on drug accumulation in clinical
material were modest compared with those seen for MDR cell lines, with a maximum
of only 20% enhancement. Moreover, there was no relationship between the extent
of PSC-833 effects on accumulation and the levels of Pgp seen in the STS samples.
Nevertheless, we show evidence that a proportion of cases of STS express moderate
to high levels of Pgp. There may be a role for MDR modulating agents in
association with doxorubicin in the treatment of these tumours, either in the
adjuvant setting or at first relapse.
PMID- 10785594
TI - C-reactive protein, procalcitonin and interleukin-8 in the primary diagnosis of
infections in cancer patients.
AB - The diagnostic utility of C-reactive protein (CRP), procalcitonin (PCT) and
interleukin-8 (IL-8) were studied in 66 cancer patients with suspected infection
(39 with definite foci of infection, 17 with antibiotic responses without foci
and 10 with neoplastic fever without infection) and 26 patients scheduled for
chemotherapy. The infection group (n=56) had higher median CRP (91 versus 19
mg/l, P<0. 001), PCT (0.28 versus 0.12 ng/ml, P<0.001) and IL-8 values (27.7
versus 16.9 pg/ml, P=0.032) than the non-infection group (n=36). In patients with
suspected infection, only PCT was a good marker to discriminate bacteraemia with
an area under the receiver operating characteristics curve of 0.92 (95%
confidence interval (CI), 0.77-1. 0), but even PCT was less well able to
differentiate between non-bacteraemic infections and neoplastic fever (0.56; 95%
CI, 0. 35-0.77). In conclusion, PCT was a good indicator for bacteraemia, but
none of the three markers were reliable indicators for minor infections in non
neutropenic cancer patients.
PMID- 10785595
TI - Sentinel node biopsy and ultrasound scanning in cutaneous melanoma: clinical and
technical considerations.
AB - 1.5 mm and in all cases with two metastatic SNs, further positive additional
nodes were found. The mean counts per 10 s (CP10S) ratio for SN and non-SN values
was 5.62 (1.29-23.51) and 3.09 (1.03-10.99) in the intra-operative and extra
operative phases, respectively. US scanning and preoperative lymphoscintigraphy
associated with PBD allows preoperative patient selection and accurate SN(s)
identification. Breslow thickness and the number of metastatic SN(s), but not
their type, are correlated with disease spread; CP10S contributed to the
differentiation amongst the nodes and the determining of procedure's completion.
PMID- 10785596
TI - Clinical prognostic factors in 1277 patients with neuroblastoma: results of The
European Neuroblastoma Study Group 'Survey' 1982-1992.
AB - In 1982 the European Neuroblastoma Study Group (ENSG) established a prospective
registry for patients with newly diagnosed neuroblastoma ('The ENSG Survey').
Clinical information was collected primarily to: (a) establish an ENSG database;
and (b) investigate prognostic factors in neuroblastoma. This paper summarises
the results of the survey. By 1992, 1277 patients with a median age of 26 months
(range: 0-289 months), gender ratio of 1.19 M:F had been registered from 30
centres. The median follow-up of survivors is 9.7 years (range: 1-14 years).
Overall 5-year survival (S) is 45% (95% CI 42-48%), and event-free survival (EFS)
is 43% (95% CI 40-45%). For both survival and EFS the key established prognostic
factors, stage and age, are highly significant (P<0.001). In particular, patients
under 1 year of age at diagnosis, whatever the disease stage, had a more
favourable prognosis than older patients; stage 2 (EFS 93% (95% (CI 85-97) versus
76% (95% CI 67-86), P=0.02), stage 3 (EFS 91% (95% CI 82-96) versus 52% (95% CI
44-60), P<0.001) and stage 4 (EFS 59% (95% CI 48-69) versus 16% (95% CI 13-19),
P<0.001). Multivariate analysis established that the anatomical location of the
primary tumour (i.e. abdominal versus other sites) and primary tumour volume also
conferred a statistically significant difference. In stage 4 disease the 20% of
patients without demonstrable bone marrow involvement had a more favourable
prognosis than those with infiltrated marrow (EFS 36% (95% CI 13-19) versus 16%
(95% CI 29-45), P<0.001). Urine catecholamine metabolite levels (raised versus
normal), histology (ganglioneuroblastoma versus neuroblastoma) and gender had no
significant effect on outcome after stage and age were accounted for. 5-year
survival following first relapse is only 5.6% (95% CI 2.8-8.4). This ENSG Survey
provides secure data for future comparisons with new prognostic factors and
treatment programmes.
PMID- 10785597
TI - Trends in mortality from primary liver cancer in Europe.
AB - Upward trends in incidence and mortality from primary liver cancer have been
reported from Japan, the USA and a few European countries. Thus, we
systematically reviewed trends in age-standardised death certification rates from
primary liver cancer between 1970 and 1996 in 20 European countries providing
data for the World Health Organisation database. Overall age-standardised (world
population) mortality rates were approximately stable or showed no consistent
trends in seven countries, including Bulgaria and Hungary (with exceedingly high
rates), Finland, The Netherlands and the UK. Moderate rises were observed in
Austria, Germany and Switzerland, and much larger upward trends in France and
Italy, particularly for males. Downward trends were observed in both sexes in
Belgium, Spain, Ireland, Greece and several Scandinavian countries. The per cent
change in rates per year ranged, for males, from -7.4% for Ireland and -5.1% for
Spain to +4.4% for Italy and +8.6% for France. Trends were more favourable in
women, with 15 out of 20 countries showing downward trends in rates, and
moderately more favourable in middle age (45-64 years) and, in major European
countries, in young adults (20-44 years of age). In conclusion, trends in liver
cancer mortality in Europe are heterogeneous. The fall in mortality in countries
like Spain may be largely explained by improvements in the distinction between
primary and secondary liver neoplasms, whereas upward trends in Central Europe
and Italy are likely to be, at least in part, real. Increases in infection with
the hepatitis C virus, and improved and increased searches for liver cancer in
cirrhotic patients are two of the likeliest explanations for these observations.
PMID- 10785598
TI - Molecular downstream events and induction of thymidylate synthase in mutant and
wild-type p53 colon cancer cell lines after treatment with 5-fluorouracil and the
thymidylate synthase inhibitor raltitrexed.
AB - Inhibition of the key enzyme in DNA synthesis, thymidylate synthase (TS), by 5
fluorouracil (5-FU) and the novel antifolate raltitrexed (Tomudex; ZD1694),
induces dTTP depletion, resulting in DNA strand breaks, which can initiate
pathways leading to an apoptotic mode of cell death. We studied 5-FU- and ZD1694
induced TS inhibition in relation to the expression of p53, p21, Bcl-2 and Bax in
six colon carcinoma cell lines, two with a wild-type (wt) p53 (Lovo, LS174T) and
four with a mutant (mt) p53 (WiDr, WiDr/F, HT29 and SW948) phenotype. In
untreated cells, a reciprocal correlation between p53 and Bcl-2 was found: in
cells with a low wt p53, Bcl-2 expression was present; whilst in cells with mt
p53, Bcl-2 expression was not detectable. Exposure to 5-FU (50 and 100 microM)
and ZD1694 (50 and 100 nM) for 24 and 48 h induced p53 and p21 expression in wt
p53 cells, but not in mt p53 cells. TS was induced approximately 2-10-fold in all
cell lines. TS induction was highest after ZD1694 exposure in the mt p53 cells
HT29 and WiDr/F (6-10-fold). After 5-FU treatment, TS was present both as the
free enzyme and in the ternary complex; however, predominantly as the ternary
complex between TS, FdUMP and 5,10-methylenetetrahydrofolate. In wt p53 cells,
both drugs increased Bax expression up to 5-fold, whereas in mt p53 cells, only a
very slight induction was found. In wt p53 cells, Bcl-2 expression hardly changed
after drug treatment. These results indicate a p53-independent induction of TS
but a regulatory role of wt p53 in the synthesis of Bax in the colon carcinoma
cell lines after TS inhibition.
PMID- 10785599
TI - Microsatellite instability is associated with genetic alteration but not with low
levels of expression of the human mismatch repair proteins hMSH2 and hMLH1.
AB - Mutational inactivation of hMSH2 or hMLH1 has been known to be responsible for
microsatellite instability and cellular resistance to DNA-damaging alkylating
agents. However, the effects of altered expression of hMSH2 or hMLH1 on
microsatellite stability and cellular response to alkylating agents has not been
well investigated. Previously, we have reported that downregulation of the hMLH1
protein was a frequent event and was closely associated with cellular resistance
to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in human gastric carcinoma cell
lines. Therefore, to investigate the relationship between microsatellite
instability and quantitative changes in hMSH2 and hMLH1, we compared the genetic
status and expression levels of hMSH2 and hMLH1 with microsatellite instability
in 11 human gastric carcinoma cell lines. Five cell lines contained wild-type
hMSH2 and hMLH1 and expressed adequate levels of hMSH2 and hMLH1 proteins. In
three cell lines, genetic alterations such as mutation in the hMLH1 gene (SNU-1)
or the hMSH2 gene (SNU-638), or hypermethylation in the promoter region of the
hMLH1 gene (SNU-520) were observed. Microsatellite instability assays revealed
that only these three cell lines exhibited microsatellite instability. Three cell
lines (SNU-216, -484, and -668) containing wild-type hMSH2 and hMLH1 genes
produced significantly downregulated hMSH2 and/or hMLH1 proteins. In spite of the
substantial decrease in the protein levels, these cell lines did not show
microsatellite instability. Together with our previous report, this study
suggests that: microsatellite instability of cells is associated only with
genetic alteration of the mismatch repair genes; relatively low levels of the
hMSH2 and hMLH1 proteins may be sufficient to retain the microsatellite stable
phenotype; and the cellular response to alkylating agents is associated with
genetic alteration and decreased expression of the mismatch repair genes in human
gastric carcinoma cell lines.
PMID- 10785600
TI - Differential response to transforming growth factor (TGF)-alpha and fibroblast
growth factor (FGF) in human renal cell carcinomas of the clear cell and
papillary types.
AB - The clear cell and the papillary types of human renal cell carcinoma (RCC) are
distinct tumour entities with marked differences in their biological properties.
Because growth factors are considered to affect profoundly the biological
behaviour of malignant tumours, we compared the expression and function of
transforming growth factor (TGF)-alpha and fibroblast growth factor (FGF) in both
types of RCCs. Both in vivo and in vitro expression of TGF-alpha, epidermal
growth factor-receptor (EGF-R), FGF-2 and FGF type 3- and 4-receptors was found
in RCCs of both types. However, marked differences between clear cell and
papillary RCCs became evident for TGF-alpha secretion, which could be
demonstrated in 20 out of 24 (83%) clear cell RCCs but in only two out of four
(50%) papillary tumours. Moreover, the mean TGF-alpha secretion rate in clear
cell RCCs significantly (P<0. 05) exceeded that of papillary RCCs. Because the
expression of growth factor receptors could not prove the corresponding
signalling cascades were functional, tumour cell proliferation was tested after
exposure to exogenous TGF-alpha or FGF-1. These experiments demonstrated that
papillary RCCs did not respond significantly to exogenous TGF-alpha or FGF-1,
whereas eight (33%) (TGF-alpha) and 11 (46%) (FGF-1) out of 24 clear cell RCCs
responded with significant (P<0.05) growth stimulation. In conclusion, our
investigation presents data indicating that TGF-alpha and FGF are functionally
involved in the progression of clear cell RCCs, directly stimulating
proliferation by autocrine and/or paracrine actions. In contrast, TGF-alpha and
FGF did not directly stimulate the proliferation of our papillary RCCs, thereby
suggesting functional defects or a blockade in the corresponding signalling
cascades. This differential functionality might contribute to the more aggressive
behaviour of clear cell RCCs.
PMID- 10785601
TI - Antitumour activity of cytotoxic liposomes equipped with selectin ligand
SiaLe(X), in a mouse mammary adenocarcinoma model.
AB - The overexpression of lectins by malignant cells compared with normal ones can be
used for the targeting of drug-loaded liposomes to tumours with the help of
specific carbohydrate ligands (vectors). Recently we have shown that liposomes
bearing specific lipid-anchored glycoconjugates on a polymeric matrix bind in
vitro to human malignant cells more effectively and, being loaded with a
lipophilic prodrug of merphalan, reveal higher cytotoxic activity compared with
unvectored liposomes. In this study, carbohydrate-equipped cytotoxic liposomes
were tested in vivo in a mouse breast cancer model, BLRB-Rb (8.17)1Iem strain
with a high incidence of spontaneous mammary adenocarcinoma (SMA). Firstly, a
cell line of the SMA was established which was then used to determine the
specificity of the tumour cell lectins. After screening of the lectin specificity
of a number of fluorescent carbohydrate probes, SiaLe(X) was shown to be the
ligand with the most affinity, and a lipophilic vector bearing this saccharide
was synthesised. Then different liposomal formulations of the synthetic merphalan
lipid derivative and SiaLe(X) vector were prepared and applied in the treatment
of mice with grafted adenocarcinomas. The results of the tumorigenesis data show
that the therapeutic efficacy of merphalan increases sharply after its insertion
as a lipophilic prodrug into the membrane of SiaLe(X)-vectored liposomes.
PMID- 10785602
TI - Optimising chemotherapy dose density and dose intensity. new strategies to
improve outcomes in adjuvant therapy for breast cancer.
PMID- 10785603
TI - The impact of chemotherapy dose density and dose intensity on breast cancer
outcome: what have we learned?
AB - Optimising chemotherapy dose density and dose intensity are strategies aimed at
improving outcomes in adjuvant therapy for patients with breast cancer. There
are, in theory, at least five models allowing the delivery of a higher overall
drug dose intensity. These are reviewed in this article and vary according to
three main variables: the dose per course, the interval between doses and the
total cumulative dose. Cyclophosphamide, anthracyclines and taxanes are among the
most active agents for the treatment of breast cancer and, as such, they have
been or are currently the focus of prospective, randomised clinical trials
testing some of these dose-intensity models in the adjuvant setting. The results
of recent trials suggest that anthracyclines, but not cyclophosphamide, are
associated with better outcomes if used at higher doses per course and at higher
cumulative doses. However, care has to be taken with premenopausal women where an
increased dose of anthracycline per course but a reduced cumulative dose appears
to produce a worse outcome. Moreover, decreasing the interval between doses, for
anthracyclines and cyclophosphamide, does not seem to provide, so far, additional
benefits for women with locally advanced breast cancer. This approach is not
feasible with docetaxel, since an increase in dose density induces unwanted side
effects. These results represent our current state of knowledge, but clinical
trials are being performed to evaluate further the effect of dose intensity, dose
density and cumulative dose of key therapeutic agents on patient outcomes.
PMID- 10785604
TI - Chemotherapy dose reduction and delay in clinical practice. evaluating the risk
to patient outcome in adjuvant chemotherapy for breast cancer.
AB - Randomised clinical trials demonstrate the importance of maintaining chemotherapy
dose and dose intensity in the systemic adjuvant treatment of breast cancer, and
show that the strategies of dose delay and dose reduction carry the risk of
suboptimal outcome. Such dose modifications are usually necessitated by the
myelosuppressive effects, specifically neutropenia, thrombocytopenia and anaemia,
resulting from the previous cycle of chemotherapy. The Canadian Database
Initiative was designed to determine the incidence of neutropenic complications
(an episode of febrile neutropenia or dose delay or reduction) and the frequency
of complications by cycle of therapy using data from patients with breast cancer
treated at centres across Canada. The centres used a variety of adjuvant
chemotherapy regimens and the database covered the treatment of 444 patients,
average age 47.7 years, who were treated between 1991 and 1996. Across all
chemotherapy regimens, 42% of patients experienced at least one complication. Of
those, 72% went on to have additional complications in subsequent cycles. The
neutropenic complications usually occurred early in the treatment schedule.
PMID- 10785605
TI - A novel approach to maintain planned dose chemotherapy on time: a decision-making
tool to improve patient care.
AB - Studies of primary prophylaxis of febrile neutropenia with recombinant
granulocyte colony-stimulating factor (r-metHuG-CSF, filgrastim), administered to
all patients starting with the initial course of chemotherapy, have demonstrated
an economic advantage over a wide range of settings. In these analyses, the
threshold risk for febrile neutropenia at which a cost saving is realised is
inversely related to the direct medical costs of hospitalisation. Clinical
practice guidelines for the use of filgrastim have been developed based on these
observations. Recent studies incorporating indirect institutional costs have
demonstrated that cost savings can be achieved at substantially lower febrile
neutropenia risk thresholds than previously estimated. Despite the demonstrated
efficacy of filgrastim in primary prophylaxis, its value may be further enhanced
through the appropriate selection of patients for such therapy and a better
understanding of the importance of sustaining dose intensity in specific
malignancies. Clinical prediction models capable of identifying individuals at
high risk for neutropenic complications yield further reductions in febrile
neutropenia risk thresholds and treatment costs in patients receiving cancer
chemotherapy. Prediction models can also be used to evaluate the cost
effectiveness or cost-efficiency of filgrastim use. Such a model has recently
been developed and validated and is described here which incorporates both
baseline clinical characteristics as well as the results of the first cycle of
chemotherapy in patients with early-stage breast cancer. A cost-effectiveness
ratio of US$ 34297 (Euro 32002)dagger per year of life saved (YLS) was calculated
based on dose-response assumptions derived from a previously reported adjuvant
breast cancer trial studying the impact of dose reduction on disease-free
survival. This figure is comparable with accepted cost-effectiveness ratios for
other interventions, e.g. US$ 45000/LYS (Euro 41989) for renal dialysis for
patients with end-stage renal disease. The cost-effectiveness of filgrastim was
evident over a wide range of clinical and cost assumptions. Clinical prediction
models permit rational and cost-effective selection of patients for filgrastim
support. Current guidelines should be re-evaluated in light of new information
available on both the total cost of febrile neutropenia, as well as the cost
effectiveness of these agents in specific clinical situations.
PMID- 10785606
TI - Cellular and genetic constitution of human endometriosis tissues.
AB - For many years, endometriosis has been an enigmatic and confusing disorder, but
there have been recent contributions to the subject, provided by modern
techniques in cellular and molecular biology, regarding the cell lineage
involved, the stage of differentiation, and genomic features. This review deals
mainly with the cellular, cytochemical, cytogenetic, and molecular cytogenetic
features of primary endometriotic lesions and cultured endometriotic cells. The
FbEM-1 cell line, taken as an in vitro model, showed cell proliferation and
differentiation features suggesting an immature endometriosis-related cell
lineage. Chromosomal analysis of these cells demonstrate a complex karyotype
including a rearrangement interpreted as der(5) t(5q34;6p11) indicating a clonal
cell proliferation. Data of recurrent DNA sequence copy number alterations
detected by the comparative genomic hybridization in a series of primary
endometriotic lesions also are described. Predominant recurrent anomalies were
found on chromosome 1p and 22q in 50% of the studied samples. Additional losses
were seen on chromosomes 5p(33%), 6q(27%), 7p(22%), 9q(22%), and 1q(22%), as well
as on 17q segments in one case. Gain of DNA sequences was seen on chromosomes 6q,
7q, and 17q. The potential role of the genetic changes identified are discussed
in relation to the putative oncogenes and/or tumor suppressor genes possibly
involved in development of endometriosis.
PMID- 10785607
TI - Gene knockout mice in the study of parturition.
AB - OBJECTIVE: To review recent studies of parturition control in mice with relevance
to understanding the control of human parturition. METHODS: Assimilation of
published studies of gene knockout mice with mutations in neuropeptides,
prostaglandin synthetic enzymes and receptors, and other molecules implicated in
parturition. RESULTS: The central role of prostaglandins in murine labor is
demonstrated by mice with gene mutations at multiple levels of the prostaglandin
synthetic pathway. In addition, novel molecules such as steroid 5 alpha-reductase
are found to play an essential role in the progression of labor. Surprisingly,
deficiency of neuropeptides such as oxytocin and corticotropin-releasing hormone
have little effect on parturition. CONCLUSION: Molecular genetic analyses in mice
provide an efficient way to define molecules critical for murine parturition.
Extrapolation of the importance of these molecules to human parturition provides
the next challenge.
PMID- 10785608
TI - Amniotic fluid volume responses to intra-amniotic infusion of lactate in fetal
sheep.
AB - OBJECTIVE: In human and ovine fetuses, severe anemia is associated with elevated
fetal blood and amniotic lactate levels and polyhydramnios. In ovine fetuses,
intravascular infusion of sodium lactate elevates fetal plasma and amniotic
lactate levels and produces polyhydramnios. The present study tested the
hypothesis that an elevated amniotic lactate concentration in the absence of an
increased fetal plasma lactate would be associated with an increase in amniotic
fluid volume (AFV). METHODS: Eight chronically catheterized, late-gestation fetal
sheep were studied over 5 days. Twice each day, we measured blood gases and pH,
electrolytes, glucose, lactate, and blood urea nitrogen (BUN) concentrations, as
well as osmolality of fetal blood, maternal blood, amniotic fluid, and fetal
urine. Amniotic fluid volume was measured once daily. During experimental days 2
to 4, lactic acid was infused into the amniotic compartment to achieve an
amniotic lactate concentration of approximately 20 mmol/L. Statistical analysis
was by analysis of variance and regression. RESULTS: Amniotic fluid lactate
levels averaged 2.2 +/- 0.4 mmol/L (mean +/- standard error) before infusion and
18.9 +/- 3.3 mmol/L during the 72-hour infusion, falling to 5.8 +/- 1.2 mmol/L
postinfusion (P < .001). Fetal plasma lactate averaged 1.8 +/- 0.1 mmol/L on day
1 and increased by 1.4 +/- 0.6 mmol/L on day 4 (P < .001). Fetal urine flow was
unchanged and averaged 0.54 +/- 0.08 mL/min over the 5 days. Amniotic fetal
volume was 821 +/- 186 mL on day 1, increased nonsignificantly by 99 +/- 95 mL on
day 4, and remained unchanged on day 5. CONCLUSIONS: The present study suggests
that if amniotic lactate acts osmotically to increase AFV, the effect is small.
Thus, the primary site of action of elevated fetal lactate levels appears to be
at the placenta rather than the intramembranous pathway.
PMID- 10785609
TI - Hypoxic-ischemic tolerance induced by hyperthermic pretreatment in newborn rats.
AB - OBJECTIVE: We investigated the effect of hyperthermic pretreatment 24 hours
before hypoxic-ischemic exposure on neuronal cell damage in 7-day-old rats.
METHODS: Newborn rats were separated on postnatal day 7 into two groups: 1)
preheated (those exposed to 2 hours of hyperthermic pretreatment at 42-43C) (n =
29), and 2) nonheated (n = 20). At 24 hours after the hyperthermic stress, rats
from both groups were subjected to left carotid artery ligation followed by 2
hours of hypoxia (8% oxygen/92% nitrogen) at 33C. All rats were killed 1 week
after hypoxia-ischemia, and brains were extracted for histologic study. A
different group of 7-day-old rats (n = 8) was placed in the same hyperthermic
environment as mentioned above for 2 hours, and 24 hours after heat exposure
brains were extracted for immunohistochemistry of heat-shock protein 70. RESULTS:
The total incidence of hypoxic-ischemic brain damage significantly decreased in
the preheated group (12 of 25 [48%]) compared with the nonheated group (17 of 20
[85%]; P < .03). The induction of immunoreactive heat-shock protein 70 was
observed mainly in glial and vascular endothelial cells and, in a lesser amount,
in neuronal cells of the cerebral cortex and hippocampus. CONCLUSION: Incidence
of hypoxic-ischemic brain damage is consistently reduced by 2 hours of
hyperthermic pretreatment in 7-day-old rats.
PMID- 10785610
TI - Aging, serum estradiol levels, and pregnancy differentially affect vascular
reactivity of the rat uterine artery.
AB - OBJECTIVES: To investigate the effects of aging, ovarian ablation, and pregnancy
on vascular reactivity of the rat uterine artery. METHODS: Segments of uterine
artery from 3-month-old pregnant and nonpregnant Wistar rats and from aged and
ovariectomized animals, both 9 months of age, were exposed in vitro to vasoactive
mediators. Absolute contractile force as well as endothelium-dependent and
independent vascular reactivity were determined. Isometric tension was recorded
using a modified Mulvany myograph system. Results were compared with analysis of
variance and Bonferroni-Dunn post hoc analysis and correlated with serum
estradiol levels. RESULTS: Aging up to 9 months decreased absolute tension of
uterine arteries in vitro elicited by KCl (P < .0001), while not affecting
receptor-operated responses to norepinephrine, endothelin-1, and angiotensin II.
After ovarian ablation maximal contraction to norepinephrine was selectively
reduced in the aged animal (P = .0053). Pregnancy increased absolute tension to
KCl (P < .0001), norepinephrine (P < .008), and endothelin-1 (P = .0003), whereas
relative contractile force (percentage of KCl) induced by norepinephrine and
endothelin-1 remained unchanged and that induced by angiotension II decreased (P
= .0001) in pregnant animals. In addition, pregnancy increased sensitivity to the
endothelium-dependent vasodilator acetylcholine (P = .0022) but decreased that to
the endothelium-independent vasodilator sodium nitroprusside (P = .0062).
Endothelium-dependent relaxation correlated with serum estrogen levels remained
unchanged in 9-month-old Wistar rats, which physiologically exhibited high serum
estrogen concentrations but was impaired with regard to both maximum relaxation
(P < .0001) and sensitivity in aged rats (P = .0007) after ovariectomy.
CONCLUSIONS: Vascular contractility is impaired in the uterine artery of the aged
rat as evidenced by reduced responses to KCl, whereas responses to receptor
operated agonists remain unchanged. Functional ovaries are essential to preserve
endothelium-dependent relaxation in aging animals. During pregnancy, contractile
machinery and endothelium-dependent relaxation are enhanced. In contrast,
contractions to angiotensin II and endothelium-independent relaxation to sodium
nitroprusside are reduced in late pregnancy. These changes in reactivity of the
uterine artery may be important for the regulation of blood flow in the uterus
according to physiologic needs.
PMID- 10785611
TI - Evidence of endothelial cytotoxic compounds in placental extracts from
preeclamptic women.
AB - OBJECTIVE: To determine whether placenta and plasma of preeclamptic women contain
factors that cause endothelial cell damage. METHODS: Placental extracts and
plasma from preeclamptic and normotensive women were added to cultures of normal
human umbilical vein endothelial cells and their effect on their viability, was
determined by MTT reduction and 51chromium release. RESULTS: Placental extracts
from normotensive and preeclamptic women were cytotoxic to endothelial cells, but
not the plasma from both groups. Mean +/- standard deviation values of
cytotoxicity index in preeclamptic and normotensive placental extracts using the
MTT reduction were 70.3 +/- 6.76% and 51.4 +/- 8.81%, respectively, showing a
significant difference (P < .0001). Using the 51chromium-release assay,
preeclamptic placental extracts showed cytotoxic effects of 87.6 +/- 13.47%
compared with 17 +/- 20.60% in control patients. The cytotoxic activity decreased
after trypsin digestion and heat treatment in both groups. CONCLUSIONS: A
cytotoxic factor to endothelial cells in placental extracts of preeclamptic women
was identified. This compound is thermolabile and sensitive to trypsin digestion.
PMID- 10785612
TI - Effects of hypoxia on regulation of prostanoid production in decidual endothelial
cells in normal and preeclamptic pregnancy.
AB - OBJECTIVES: To examine the effect on prostacyclin and thromboxane production of
incubating decidual endothelial cells under hypoxic conditions, comparing cells
from normal and preeclamptic pregnancies. Furthermore, to determine whether
hypoxia is deleterious to cell growth, and test the effects of stimulation and
inhibition on prostanoid production. METHODS: Decidual endothelial cells were
exposed for a total of 40 hours to normoxic (20% O2) or hypoxic (2% O2)
conditions. Prostacyclin and thromboxane secretion over the final 24 hours of
incubation was measured and cell numbers after incubation determined.
Lipopolysaccharide (LPS) (1.0 microgram/mL) was used as a stimulator and
pirmagrel (1.0 mumol/L) and tranylcypromine (10.0 mumol/L) as prostanoid synthase
inhibitors. RESULTS: Incubations in hypoxia resulted in increased thromboxane (P
< .05) but no change in prostacyclin production. This thromboxane increase was
abrogated by pirmagrel. LPS caused significant stimulation of prostacyclin and
thromboxane secretion and both LPS and hypoxia resulted in lower cell numbers.
Decidual endothelial cells from normal and preeclamptic pregnancies were
generally not different. CONCLUSIONS: This study indicates that in preeclampsia,
where decidual endothelial cells are in a relatively more hypoxic environment,
thromboxane production by these cells is likely to be increased and the
prostacyclin/thromboxane ratio decreased. The thromboxane synthase inhibitor,
pirmagrel, was able to reverse this abnormal increased secretion of thromboxane
in vitro.
PMID- 10785613
TI - Photodynamic endometrial ablation in the nonhuman primate.
AB - OBJECTIVE: To test the effectiveness of 5-aminolevulinic acid (ALA)-induced
photodynamic endometrial ablation in the rhesus monkey under varying conditions
of light delivery (fractionated versus continuous) and steroid priming. METHODS:
Photodynamic endometrial ablation was carried out in 17 rhesus monkeys that were
either postmenopausal or in the early proliferative phase. Four hours after
intralumenal injection of ALA (250 mg in 1 mL hyskon), a quartz fiber with a
diffusing tip was inserted. A KTP tunable dye laser delivered 300 mW of light
(635 nm) for 60 minutes in either continuous or fractionated fashion (20 minutes
on, 5 minutes off, and 40 minutes on). In some experiments, thermistors were used
to monitor temperature in the lumen and myometrium during light treatment.
Hysterectomy was performed 3 or 4 days after treatment, and endometrial damage
was assessed histologically. Two additional monkeys (one rhesus and one
cynomolgus monkey) were exposed to the same protocol, except hyskon was
substituted for ALA to control for potential ablative effects due to light
treatment alone. RESULTS: Endometrial ablation was evident in all ALA
photosensitized specimens. The degree of ablation around the light fiber ranged
from moderate to complete. The depth of ablation ranged from 1.14 +/- 0.54 to
2.15 +/- 1.62 mm (mean +/- standard deviation). Ablation was most complete in
uteri of menopausal monkeys. Light treatment after ALA increased lumenal
temperature from 36 C to 50 C, whereas temperature was not significantly
increased by light treatment in the controls. CONCLUSION: This is the first
report of endometrial destruction in the primate using a photodynamic approach.
Whereas clinical application of photodynamic therapy (PDT) requires complete
endometrial ablation to produce long-lasting amenorrhea, our results suggest that
PDT may offer a simple office-based approach to endometrial ablation.
PMID- 10785614
TI - Human first trimester fetal ovaries express oncofetal antigens and steroid
receptors.
AB - OBJECTIVE: To document the expression of oncofetal antigens and steroid receptors
in first trimester human fetal ovaries and to determine the effect of advancing
gestation on expression patterns. METHODS: Fetal gonads were collected from
surgical terminations of pregnancy, and fetal sex was determined by fluorescence
in situ hybridization. Immunocytochemical analysis was performed on paraffin
sections of microdissected fetal ovaries using antibodies to carcinoembryonic
antigen (CEA), placental alkaline phosphatase (PLAP), hCG, alpha fetoprotein
(AFP), CA 125, estrogen receptor (ER) and progesterone receptor (PR) in 12 first
trimester human fetal ovaries. Expression was quantified objectively by measuring
percentage area of immunoreactivity (PAI) on whole sections of the ovary using an
interactive image analysis system. Two pathologists, blinded to the antibodies
used, independently viewed and scored all sections. RESULTS: PLAP, PR, ER and CEA
were expressed in all 12 ovaries (31%, 28%, 21%, and 16% mean PAI, respectively).
A diffuse staining pattern was observed at 8 weeks' gestation, which was more
focal and confined to the cortical regions of the gonad by 12 weeks' gestation.
Putative primordial germ cells were positive for PLAP, PR and ER but rarely for
CEA. The expression (PAI) of PLAP and PR was unchanged during the first
trimester, whereas that of ER decreased from 28% to 12%. The expression of CEA
and hCG decreased from 8 to 11 weeks and then increased markedly by 13 weeks. AFP
had a medullary distribution and was expressed in nine of 12 ovaries (mean PAI
18%). CA 125 expression was minimal or undetected. CONCLUSION: PLAP, ER and PR
were the most extensively expressed protein antigens, particularly in fetal
ovarian cortex. These variable patterns of expression suggest levels of
differentiation in the immature first trimester human fetal ovary.
PMID- 10785615
TI - Short-wavelength automated perimetry: it's role in the clinic and for
understanding ganglion cell function.
AB - Short-wavelength automated perimetry (SWAP) is a more sensitive test than
standard achromatic perimetry for early loss of vision due to glaucoma and other
ocular and neurological diseases. SWAP is also more successful for detecting
changes in vision as glaucoma progresses. Results from various visual function
specific tests, including SWAP, suggest that there are individual differences in
ocular hypertensive and glaucoma eyes in the subtype of ganglion cell first
affected. However, the disease targets the same retinal area for all function
specific tests that show a deficit in a given individual. Psychophysical tests of
vision are critical to understand glaucoma's effect on retinal ganglion cells, to
verify the success or failure of treatment including new neuroprotective agents,
and to determine the relationship of genetic markers for glaucoma to the presence
and progress of the disease.
PMID- 10785616
TI - Molecular evolution of vertebrate visual pigments.
AB - Dramatic improvement of our understanding of the genetic basis of vision was
brought by the molecular characterization of the bovine rhodopsin gene and the
human rhodopsin and color opsin genes (Nathans and Hogness, 1983; Nathans et al.,
1984, 1986a,b). The availability of cDNA clones from these studies has
facilitated the isolation of retinal and nonretinal opsin genes and cDNA clones
from a large variety of species. Today, the number of genomic and cDNA clones of
opsin genes isolated from different vertebrate species exceeds 100 and is
increasing rapidly. The opsin gene sequences reveal the importance of the origin
and differentiation of various opsins and visual pigments. To understand the
molecular genetic basis of spectral tuning of visual pigments, it is essential to
establish correlations between a series of the sequences of visual pigments and
their lambda(max) values. The potentially important amino acid changes identified
in this way have to be tested whether they are in fact responsible for the
lambda(max)-shifts using site-directed mutagenesis and cultured cells. A major
goal of molecular evolutionary genetics is to understand the molecular mechanisms
involved in functional adaptations of organisms to different environments,
including the mechanisms of the regulation of the spectral absorption. Therefore,
both molecular evolutionary analyses of visual pigments and vision science have
an important common goal.
PMID- 10785617
TI - The role of photoreceptors in the control of refractive state.
AB - The current state of research into experimentally induced refractive errors is
reviewed. The area is analysed in three components-the transduction of defocus or
deprivation, the vector for transmitting the error message from the retina to the
outer tunics of the eye, and the identity of the effector for causing growth
modulation in the sclera. Anatomical, pharmacological, electrophysiological and
optical factors are considered in terms of which elements of the retina are
necessary to support a refractive response to deprivation or defocus. Two of the
current models are discussed-one emphasizing the role of the choroid in effecting
ocular and refractive change, while the second model approaches the problem from
the aspect of scleral changes that are associated with growth adaptation without
emphasis on the error detection mechanism. A third model is proposed in which the
error signal for deprivation or defocus is detected in the outer retina and where
error is translated through separate signals for stimulus brightening and
darkening into a net signal for fluid flow across and under the active control of
the retinal pigment epithelium with the fluid communication between the vitreous
chamber and the choroidal lymphatics. The directions of research both fundamental
and clinical which are needed to create pharmaceutical or environmental solutions
to refractive control are discussed.
PMID- 10785618
TI - Microvascular effects of selective prostaglandin analogues in the eye with
special reference to latanoprost and glaucoma treatment.
AB - Prostaglandin F(2alpha) analogues have recently been introduced on the market for
glaucoma treatment. While these drugs have a well-documented intraocular pressure
reducing effect only a limited number of studies have been published regarding
their effects on the microvasculature in the eye. Since many naturally occurring
prostaglandins have marked effects on the cardiovascular system it is conceivable
that synthetic prostaglandins used as glaucoma drugs may exert microvascular
effects in the eye, even if they exhibit receptor selectivity. Latanoprost, the
active principle of Xalatan((R)) eye drops, is a selective FP prostanoid receptor
agonist, and much of the paper is focused on the microvascular effects of
latanoprost and some closely related prostaglandin analogues. The purpose of the
paper is to review the literature on the microvascular effects of prostaglandins
in the eye, and to present some unpublished data on the effects of selective
prostaglandin analogues. Most of the prostaglandin analogues studied exhibit
selectivity for the FP prostanoid receptor. Results from studies with the
following prostaglandin analogues are presented in the paper: PGF(2alpha)
isopropyl ester (PGF(2alpha)-IE), 17-phenyl-18,19,20-trinor-PGF(2alpha)-isopropyl
ester (17-phenyl-PGF(2a)-IE), 15-keto-17-phenyl-18,19, 20-trinor-PGF(2alpha)
isopropyl ester (15-keto-17-phenyl-PGF(2a)-IE), 13,14-dihydro-17-phenyl-18,19,20
trinor-PGF(2alpha)-isopropy l ester (latanoprost), 13,14-dihydro-15R,S-17-phenyl
18,19, 20-trinor-PGF(2alpha)-isopropyl ester (PhXA34), 17-phenyl-18,19, 20-trinor
PGE(2)-isopropyl ester (17-phenyl-PGE(2)-IE), and 19R-hydroxy-PGE(2) (19R-OH
PGE(2)). The regional blood flow has been determined with radioactively labelled
microspheres, the blood volume with (51)Cr labelled erythrocytes and the
capillary permeability to albumin with (125)I and (131)I labelled albumin.
PGF(2alpha)-IE has been shown to exert marked microvascular effects in the rabbit
anterior segment including vasodilatation, increased capillary permeability, and
a breakdown of the blood-aqueous barrier. 17-phenyl-PGF(2alpha)-IE, 15-keto-17
phenyl-PGF(2alpha)-IE, and PhXA34/latanoprost exerted significantly less
vasodilatory effect, and little effect on capillary permeability was seen with
the FP receptor agonists when studied with Evans blue. Intravenous administration
of PhXA34 at a dose range of 1-100 microg/kg b.w. had no consistent effect on the
regional blood flow in the eye indicating that FP receptors in the ocular blood
vessels are not expressed in the rabbit, or alternatively are not functionally
coupled to regulation of vascular tone. In cats topical application of
PGF(2alpha)-IE had no significant effect the on the regional blood flow in
cannulated eyes. No blood flow experiments were performed in intact eyes with
PGF(2alpha)-IE. 17-phenyl-PGF(2alpha)-IE and latanoprost caused some vasodilation
in the anterior segment. None of the analogues had any significant effect on the
blood volume in the ocular tissues, but an increase in capillary permeability to
albumin was seen in several tissues of the eye. However, in the eyelid,
nictitating membrane and conjunctiva exposed to high concentrations of the
prostaglandins no or only little leakage of albumin was detected. It appears that
the intraocular microvasculature in the cat exhibits some sensitivity to FP
prostanoid receptor agonists. (ABSTRACT TRUNCATED)
PMID- 10785619
TI - Genetics and brain injury: apolipoprotein E.
AB - Apolipoprotein E (apo E) is a lipoprotein produced by astrocytes and microglia
and has a proposed role in transporting lipids to injured neurons. There are
three known isoforms of apo E, coded for by the APOE epsilon2, APOE epsilon3, and
APOE epsilon4 genes. The APOE epsilon4 genotype has been implicated as a risk
factor for Alzheimer's disease. Recent studies have suggested that APOE epsilon4
may influence the central nervous system's response to injury. This article
presents an overview of the relationship between apo E, Alzheimer's disease, and
head injury and reviews recent studies implicating APOE epsilon4 as a possible
genetic determinant in recovery from head injury.
PMID- 10785621
TI - Evaluating fitness to drive after cerebral injury: basic issues and
recommendations for medical and legal communities.
AB - Specialists in rehabilitation are typically called upon to evaluate and render an
opinion about whether or not a person can be entrusted to resume driving. And,
because driving is an individual privilege to be balanced against the public's
right to safety and protection from the dangers of a driver whose residual
deficits may impede ability to drive safely, these specialists have developed a
number of methods to assess fitness to drive. Unfortunately, many evaluators
remain unfamiliar with research used as basis for evaluations or lack
understanding of the strengths and weaknesses of tests in use. Therefore, there
may be unquestioning trust in tests and methods that leads to errors of
significant consequence in decisions about fitness to drive as well as
unawareness of expanding risks of litigation that can emanate from inappropriate
recommendations. This article intends to draw attention to issues,
considerations, and problems underlying the conduct of driver evaluations,
including focus on ways in which the legal and medical communities approach
question of fitness, legal and medical definitions and terminology,
responsibility for assessment as well as tests and methods used in evaluations.
Conclusions are drawn from discussion of these matters and recommendations are
outlined for addressing identified problems at the interface between medical and
legal communities.
PMID- 10785620
TI - The hippocampus: anatomy, pathophysiology, and regenerative capacity.
AB - Cognitive deficits following insults to the central nervous system-particularly
those involving the hippocampus and related structures-are often persistent and
severely debilitating. Progress has been made in establishing the role of the
hippocampus in integrating information in the formation of memory necessary for
subsequent recollection of information. The present article will review anatomic,
physiological, and functional aspects of the hippocampus in reference to learning
and memory. Both animal and human hippocampal pathophysiological processes will
be explored. Adaptive and maladaptive central nervous system responses will be
reviewed, with a special emphasis on neurogenesis. Ideally, physiological and
cellular compensatory responses ought to parallel clinical observation. However,
this association is not clearly established. Finally, the current understanding
of neuromodulatory mechanisms (although quite preliminary) will also be
discussed.
PMID- 10785622
TI - Psychological distress and family satisfaction following traumatic brain injury:
injured individuals and their primary, secondary, and tertiary carers.
AB - OBJECTIVE: To assess family psychosocial outcome following traumatic brain injury
(TBI) in all family members, including relatives more peripheral to the person
with the injury. DESIGN: A cross-sectional design was used to gather outcome data
from individuals with TBI and primary, secondary, and tertiary carers, 19.3
months posttrauma. Multivariate analyses of variance (ANOVAs) ascertained
differences in levels of psychological distress and family satisfaction within
families. SETTING AND PARTICIPANTS: Seventy-nine families (65 individuals with
TBI, 72 primary carers, 43 secondary carers, and 22 tertiary carers) were drawn
from a sample of outpatients of three metropolitan, acute rehabilitation
hospitals over a 12-month period. OUTCOME MEASURES: In addition to using the
Family Satisfaction Scale (FSS), measures of psychological distress included the
Beck Depression Inventory (BDI), State Anxiety Inventory (SAI), and Profile of
Mood States (POMS). RESULTS: Although it was noted that a significant proportion
of family members were not psychologically distressed and reported good family
satisfaction, people with TBI remain at greater risk of poor psychosocial outcome
than do their relatives. Of other family members, primary carers-particularly
wives-are at greatest risk of poor psychosocial outcome, and a number of
secondary and tertiary carers also displayed high levels of psychological
distress. CONCLUSIONS: Male relatives (the majority of whom were secondary or
tertiary carers) may report their distress in terms of anger and fatigue, rather
than as depression and anxiety. Future research could develop TBI-specific
measures of anger and fatigue as screening instruments to identify peripheral
family members requiring assistance in adapting to TBI. Many families-despite
their initial traumatic experience-eventually cope well, encouraging researchers
and clinicians to focus future research efforts on those families who have made
good adjustments to TBI.
PMID- 10785623
TI - Social problem solving in children with acquired brain injuries.
AB - OBJECTIVES: To assess the performance of children with acquired brain injuries
(ABIs) on a measure of social problem solving and to examine the relationships
between participant characteristics and performance on the Social Knowledge
Interview (SKI) and between parent-reported child behavior and performance on the
SKI. DESIGN: Between-group comparisons using correlational analyses, matched
pairs t-tests, and analysis of covariance (ANCOVA). PARTICIPANTS: Thirty-one
children 6-12 years old with ABI and 31 control participants, matched on age and
sex. MAIN OUTCOME MEASURE: The SKI, a measure of social problem-solving skills.
RESULTS: Using matched pairs t-tests and ANCOVA, groups were compared on several
SKI measures, including the number of unique responses generated for each problem
scenario, the quality of those responses, and the ability to select the best
response from a set of alternatives. When equated for socioeconomic status (SES),
ABI and control participants performed similarly on the SKI; however, a trend for
children with ABI to generate more assertive responses was observed. Performance
on the SKI was positively correlated with IQ and related to parent-reported
adaptive behavior. In children with ABI, performance was also related to primary
lesion location and treatment regimen. CONCLUSIONS: Children with ABI are as
capable of judging the appropriateness of behavior and generating response
options on an analog measure of social problem solving as were their typically
developing peers. However, those individual children with ABI who are more likely
to have social problems may be identified by the qualitative aspects of their
responses on analog tasks. These findings have implications for the
identification of children with social skills deficits following ABI and for the
development of effective rehabilitation strategies.
PMID- 10785624
TI - Speed of information processing in traumatic brain injury: modality-specific
factors.
AB - OBJECTIVE: To assess speed of information processing by two serial addition tests
(one visual, one auditory) in individuals with moderate-to-severe traumatic brain
injuries (TBIs) and in a healthy, normal control group (NC). The tasks were
designed to equate and control for accuracy of performance across the TBI and NC
groups, thus allowing for quantification of information processing speed. DESIGN:
Performance across groups and tasks were compared using 2 x 2 repeated measure
analyses of variance (ANOVAs). In addition, each individual's processing speed
was used to adjust rate of stimulus presentation on a subsequent "rehabilitation"
trial to determine further whether this adjustment equated accuracy of
performance. SETTING: Rehabilitation hospital. PATIENTS: 22 outpatients with
moderate-to-severe TBI (6 women, 16 men; mean age = 34.6 years; duration of loss
of consciousness = 22.6 days) and 20 age- and education-matched healthy controls.
RESULTS: Processing speed was slower in TBI subjects, relative to controls and
was significantly related to measures of executive functioning for those with
TBI. Relative to controls, speed of processing in the TBI group was
disproportionately slower when information was presented in the auditory,
relative to the visual, modality. CONCLUSIONS: Speed of information processing is
a major impairment in those with TBI when unconfounded by performance accuracy.
The modality-specific impairment observed in the TBI group may, in part, be due
to a greater within-modality interference effect created by the auditory version
of the task. By manipulating information at a pace customized for an individual
through compensatory strategies and environmental modifications, information
processing performance of TBI participants can be enhanced significantly.
PMID- 10785625
TI - Validity of the Orientation Log, relative to the Galveston Orientation and
Amnesia Test.
AB - OBJECTIVE: To establish the validity of the Orientation Log (O-Log) by comparison
with the Galveston Orientation and Amnesia Test (GOAT). DESIGN: Correlation of
daily measures of orientation. SETTING: Acute rehabilitation hospital. SUBJECTS:
Sixty-eight inpatients receiving rehabilitation following traumatic brain injury
(TBI). PRIMARY MEASURES: The O-Log and GOAT. RESULTS: There was a significant
correlation between the GOAT and O-Log (r = .901, P<.001). A cutoff of 25 on the
O-Log was found to be comparable with the 75 cutoff on the GOAT. The scales were
equivalent in measuring duration of posttraumatic amnesia. CONCLUSIONS: The O-Log
is a valid measure of orientation for people with TBI and offers some advantages
in administration over the GOAT.
PMID- 10785626
TI - Pharmacological therapeutics in nutritional management.
PMID- 10785627
TI - Research ethics in head trauma rehabilitation.
PMID- 10785628
TI - The ASM in the new millennium
PMID- 10785629
TI - The dawning of molecular genetics.
PMID- 10785630
TI - Microbial pathogenesis: new paths into a new millennium.
PMID- 10785631
TI - The good old days are now.
PMID- 10785632
TI - Discovery of the anthrax toxin: the beginning of in vivo studies on pathogenic
bacteria.
PMID- 10785633
TI - Pathogenic fungi in the 21st century.
PMID- 10785634
TI - From flagellum assembly to virulence: the extended family of type III export
chaperones.
PMID- 10785635
TI - Yop effectors of Yersinia spp. and actin rearrangements.
PMID- 10785636
TI - DNA microarrays: translational tools for understanding the biology of
Mycobacterium tuberculosis.
PMID- 10785637
TI - Type III machines of Gram-negative bacteria: delivering the goods.
AB - Many Gram-negative pathogens use a type III secretion machine to translocate
protein toxins across the bacterial cell envelope. Pathogenic Yersinia spp.
export at least 14 Yop proteins via a type III machine, which recognizes
secretion substrates by signals encoded in yop mRNA or chaperones bound to
unfolded Yop proteins. During infection, substrate recognition appears to be
regulated in a manner that allows the Yersinia type III pathway to direct Yops to
the bacterial envelope, the extracellular medium or into the cytosol of host
cells.
PMID- 10785638
TI - Regulation of expression of methane monooxygenases by copper ions.
AB - Many methanotrophs contain both a soluble and a particulate methane
monooxygenase. A unique metabolic switch, mediated by copper ions, regulates the
expression of these enzymes. When the copper-to-biomass ratio of the cell is low,
the soluble enzyme is expressed, and when the copper-to-biomass ratio is high,
the particulate enzyme is expressed. A model for the mechanism of this switch is
proposed.
PMID- 10785639
TI - Common molecular mechanisms of symbiosis and pathogenesis.
AB - Traditionally, symbiotic and pathogenic interactions were considered different
manifestations of the bacteria-host interaction. However, the molecular
mechanisms that mediate communication between and cellular modulation of the
involved partners are quite similar. With this review we aim to contribute to a
reduction of the traditional gap between symbiosis and pathogenesis research.
PMID- 10785641
TI - The eukaryotic-like Ser/Thr protein kinases of Mycobacterium tuberculosis.
AB - In bacteria, extracellular signals are generally transduced into cellular
responses via a two-component system. However, genome sequence data have now
revealed the presence of 'eukaryotic-like' protein kinases and phosphatases.
Mycobacterium tuberculosis appears to be unique among bacteria in that its genome
contains 11 members of a newly identified protein kinase family. These M.
tuberculosis eukaryotic-like protein kinases could be key regulators of metabolic
processes, including transcription, cell development and interactions with host
cells.
PMID- 10785640
TI - The staphylococcal transferrin receptor: a glycolytic enzyme with novel
functions.
AB - To obtain iron from the host for growth, staphylococci have evolved sophisticated
iron-scavenging systems including siderophores and a cell surface receptor for
transferrin, the mammalian iron-transporting glycoprotein. The staphylococcal
transferrin receptor has been identified as a member of a newly emerging family
of multifunctional, cell-surface-associated glyceraldehyde-3-phosphate
dehydrogenases, which not only retain their glycolytic enzyme activities but also
bind diverse human serum proteins and possess NAD-ribosylating activity. These
multiple functions suggest a potential contribution to virulence far beyond iron
acquisition.
PMID- 10785642
TI - Learning about kainate receptors.
PMID- 10785644
TI - Nitric oxide, glial cells and neuronal degeneration in parkinsonism.
PMID- 10785643
TI - Beta-secretase revealed: starting gate for race to novel therapies for
Alzheimer's disease.
PMID- 10785645
TI - Reply: a new look at the pathogenesis of Parkinson's disease
PMID- 10785646
TI - Tachykinin autoreceptors in the gut.
PMID- 10785647
TI - Identification of the real molecular target for HIV inhibitors.
PMID- 10785648
TI - Reply: effect of radioligand contamination on the analysis of homologous
competition experiments
PMID- 10785649
TI - Inflammation-coagulation network: are serine protease receptors the knot?
AB - Following an injury, the body recruits a mechanism to delimit and repair tissue
damage; this phenomenon is known as inflammation. Among the several different
pathways that are activated during this process, which is necessary for survival,
activation of the coagulation pathway is a key feature. In fact, clinical changes
in blood fluidity have been closely related to ongoing inflammation. Recent
evidence suggests that serine protease receptors might play a major role in the
host defence mechanism at the interface between coagulation and inflammation.
PMID- 10785650
TI - The troubled story of tachykinins and neurokinins.
AB - A family of peptides that shares a common C-terminal sequence (Phe-X-Gly-Leu
MetNH2) exists in mammalian and non-mammalian species. In mammals, three of these
peptides (substance P, neurokinin A and neurokinin B) satisfy the criteria to be
considered as neurotransmitters either in the central, peripheral or enteric
nervous systems. In addition, multiple receptors for these peptides, which belong
to the superfamily of G-protein-coupled receptors, exist. These receptors have
distinct pharmacological features and selective agonists and antagonists are
available for studying their functional roles. The latest update on nomenclature
of these peptides and their receptors, which dates back to 1986, agreed to use
the terms tachykinins and tachykinin NK1, NK2 and NK3 receptors. This
'nomenclature mismatch' has generated confusion that urges experts in the field
of tachykinin research to provide a revised nomenclature.
PMID- 10785651
TI - Using green fluorescent proteins to study G-protein-coupled receptor localization
and trafficking.
AB - G-protein-coupled receptors (GPCRs) mediate a diverse array of biological
functions as a result of their ability to respond selectively to extracellular
stimuli, which ultimately results in cell-specific activation of signaling
cascades. Generally, GPCR activation is followed rapidly by a loss of
responsiveness, termed desensitization, which is then followed by a period of
recovery or resensitization. These changes in signaling potential are tightly
regulated, primarily via mechanisms that involve GPCR phosphorylation and
trafficking to distinct locations within the cell. Tagging of GPCRs with the
green fluorescent protein (GFP) has enabled the direct visualization of real-time
trafficking of GPCRs in living cells. Such analyses have provided crucial insight
into the mechanisms involved in controlling GPCR function.
PMID- 10785652
TI - Identification of PKC-isoform-specific biological actions using pharmacological
approaches.
AB - The protein kinase C (PKC) family consists of at least 12 isoforms that possess
distinct differences in structure, substrate requirement, expression and
localization. To date, identification of the physiological function of individual
PKC isoforms has been restricted by the availability of few agents that inhibit
or activate the isoforms with specificity. More recent approaches that are used
to modulate PKC isoforms include oligonucleotide antisense technology, and
peptide fragments to either inhibit or promote translocation of PKC isoforms to
specific anchoring proteins. In this review, several currently available
inhibitors and activators of PKC that display varying degrees of selectivity for
the PKC isoforms will be discussed.
PMID- 10785654
TI - Liposome treatment offers amputation reprieve.
PMID- 10785653
TI - Is agmatine a novel neurotransmitter in brain?
AB - Recent evidence suggests that agmatine, which is an intermediate in polyamine
biosynthesis, might be an important neurotransmitter in mammals. Agmatine is
synthesized in the brain, stored in synaptic vesicles in regionally selective
neurons, accumulated by uptake, released by depolarization, and inactivated by
agmatinase. Agmatine binds to alpha2-adrenoceptors and imidazoline binding sites,
and blocks NMDA receptor channels and other ligand-gated cationic channels.
Furthermore, agmatine inhibits nitric oxide synthase, and induces the release of
some peptide hormones. As a result of its ability to inhibit both hyperalgesia
and tolerance to, and withdrawal from, morphine, and its neuroprotective
activity, agmatine has potential as a treatment of chronic pain, addictive states
and brain injury.
PMID- 10785656
TI - Gene therapy leads to sporting success.
PMID- 10785655
TI - New first-line monotherapy for epilepsy.
PMID- 10785657
TI - Brain drug delivery technologies: novel approaches for transporting therapeutics.
AB - The blood-brain barrier (BBB) denies many therapeutic agents access to brain
tumours and other diseases of the central nervous system (CNS). Despite
remarkable advances in our understanding of the mechanisms involved in the
development of the brain diseases and the actions of neuroactive agents, drug
delivery to the brain remains a challenge. For more than 20 years, extensive
efforts have been made to enhance delivery of therapeutic molecules across
vascular barriers of the CNS. The current challenge is to develop drug-delivery
strategies that will allow the passage of drug molecules through the BBB in a
safe and effective manner, and this review will provide an insight into some of
the strategies developed to enhance drug delivery across the BBB.
PMID- 10785658
TI - Therapeutic applications of colloidal drug carriers.
AB - Colloidal drug carriers such as liposomes and nanoparticles can be used to
improve the therapeutic index of both established and new drugs by modifying
their distribution, and thus increasing their efficacy and/or reducing their
toxicity. This is because the drug distribution then follows that of the carrier,
rather than depending on the physicochemical properties of the drug itself. If
these delivery systems are carefully designed with respect to the target and the
route of administration, they may provide one solution to some of the delivery
problems posed by new classes of active molecules, such as peptides and proteins,
genes and oligonucleotides. They may also offer alternative modes for more
conventional drugs, such as highly hydrophobic small molecules. This review
discusses the use of colloidal, particulate carrier systems (25 nm to 1 um in
diameter) in such applications.
PMID- 10785659
TI - Optimal process design for the manufacture of transdermal drug delivery systems.
AB - In a pharmaceutical market characterized by increasing competition, assessment
criteria related to system design are assuming greater importance. This is true
for both conventional dosage forms and drug delivery systems (DDS), as
manufacturers strive to achieve adequate patient convenience and compliance. At
the same time, the process design for the manufacture of DDS must comply with
current good manufacturing practices, and give sufficient consideration to
associated environmental issues. Related problems must be solved under social and
safety pressures, which, in turn, become economic pressures, such as the
consideration of control methods. In addition, both the system design and the
process design have a major impact on the cost of goods, as well as on the levels
of complexity or risk associated with development.
PMID- 10785660
TI - Monitor: progress and profiles.
AB - Monitor provides an insight into the latest developments in pharmaceutical
science and technology through brief synopses of recent presentations,
publications and patents, and expert commentaries on the latest technologies.
There are two sections: Progress summarizes the latest developments in
pharmaceutical process technology, formulation, analytical technology,
sterilization, controlled drug delivery systems and regulatory issues; Profiles
offers expert commentary on emerging technologies, novel processes and strategic,
organizational and logistic issues underlying pharmaceutical R&D.
PMID- 10785661
TI - Development of a CFC-free glucocorticoid metered-dose aerosol system to optimize
drug delivery to the lung.
PMID- 10785662
TI - Sensory transduction of blue light in guard cells.
PMID- 10785663
TI - Is abscisic aldehyde really the immediate precursor to stress-induced ABA?
PMID- 10785664
TI - Plant glutathione S-transferases: enzymes with multiple functions in sickness and
in health.
AB - Glutathione S-transferases (GSTs) are abundant proteins encoded by a highly
divergent, ancient gene family. Soluble GSTs form dimers, each subunit of which
contains active sites that bind glutathione and hydrophobic ligands. Plant GSTs
attach glutathione to electrophilic xenobiotics, which tags them for vacuolar
sequestration. The role of GSTs in metabolism is unclear, although their complex
regulation by environmental stimuli implies that they have important protective
functions. Recent studies show that GSTs catalyse glutathione-depend-ent
isomerizations and the reduction of toxic organic hydroperoxides. GSTs might also
have non-catalytic roles as carriers for phytochemicals.
PMID- 10785665
TI - The WRKY superfamily of plant transcription factors.
AB - The WRKY proteins are a superfamily of transcription factors with up to 100
representatives in Arabidopsis. Family members appear to be involved in the
regulation of various physio-logical programs that are unique to plants,
including pathogen defense, senescence and trichome development. In spite of the
strong conservation of their DNA-binding domain, the overall structures of WRKY
proteins are highly divergent and can be categorized into distinct groups, which
might reflect their different functions.
PMID- 10785666
TI - Plant one-carbon metabolism and its engineering.
AB - The metabolism of one-carbon (C1) units is vital to plants. It involves unique
enzymes and takes place in four subcellular compartments. Plant C1 biochemistry
has remained relatively unexplored, partly because of the low abundance or the
lability of many of its enzymes and intermediates. Fortunately, DNA sequence
databases now make it easier to characterize known C1 enzymes and to discover new
ones, to identify pathways that might carry high C1 fluxes, and to use
engineering to redirect C1 fluxes and to understand their control better.
PMID- 10785667
TI - Progress in the molecular genetic analysis of trichome initiation and
morphogenesis in Arabidopsis.
AB - Arabidopsis trichomes are large unicellular structures that develop on the
surface of most shoot-derived organs. In leaves, the number, spacing and shape of
trichomes is tightly regulated, and this process has been used as an experimental
system to study the control of cell fate and pattern formation. The control of
trichome initiation is complex: both the potential of a cell to adopt the
trichome cell fate and an intricate signaling pathway determine the pattern of
trichome initiation events. Several important new results suggest that trichome
initiation and morphogenesis are redundantly regulated by both positive and
negative factors. A testable model for the control of trichome initiation is
presented.
PMID- 10785668
TI - Coping with multiple enemies: an integration of molecular and ecological
perspectives.
AB - How plants respond to attack by the range of herbivores and pathogens that
confront them in the field is the subject of considerable research by both
molecular biologists and ecologists. However, in spite of the shared focus of
these two bodies of research, there has been little integration between them. We
consider the scope for such integration, and how greater dialogue between
molecular biologists and ecologists could advance understanding of plant
responses to multiple enemies.
PMID- 10785669
TI - Does the plant mitochondrion integrate cellular stress and regulate programmed
cell death?
AB - Research on programmed cell death in plants is providing insight into the
primordial mechanism of programmed cell death in all eukaryotes. Much of the
attention in studies on animal programmed cell death has focused on determining
the importance of signal proteases termed caspases. However, it has recently been
shown that cell death can still occur even when the caspase cascade is blocked,
revealing that there is an underlying oncotic default pathway. Many programmed
plant cell deaths also appear to be oncotic. Shared features of plant and animal
programmed cell death can be used to deduce the primordial components of
eukaryotic programmed cell death. From this perspective, we must ask whether the
mitochondrion is a common factor that can serve in plant and animal cell death as
a stress sensor and as a dispatcher of programmed cell death.
PMID- 10785670
TI - Shorter hospital stays for angioplasty patients who receive abciximab.
AB - The purpose of this retrospective study is to examine the effect of abciximab
treatment on hospital length of stay for patients undergoing angioplasty in a
naturalistic setting. Multivariate analysis was used to control for a wide range
of factors (patient demographics, insurance provider, health conditions,
admission and discharge information, and hospital characteristics) that may
influence length of stay. Estimation was conducted on a sample of 13,384
angioplasty patients via a two-stage sample selection model. In addition, the
model was re-estimated for a subgroup of 4,800 patients who underwent angioplasty
and were also diagnosed with acute myocardial infarction. The study finds that
patients in poorer health were more likely to receive abciximab. After adjusting
for high-risk indications and selection bias, results also indicate that
angioplasty patients (n = 13,384) who are given abciximab have a significantly
shorter length of stay (0.89+/-0.12 fewer days) than those patients who did not
receive abciximab. In a subgroup analysis of patients who had an acute myocardial
infarction (n = 4,800), patients receiving abciximab were also found to have
significantly shorter hospital stays (0.54+/-0.26 fewer days) than patients who
did not receive abciximab. These results indicate that there are potential
economic benefits for hospitals administering abciximab.
PMID- 10785671
TI - Clinical and angiographic outcome of stent implantation without predilatation
using the Jostent Flex stent.
AB - Conventional stenting requires predilatation which potentially increases vessel
wall injury and cost of the procedure. In this study, the safety and efficacy of
direct Jostent Flex (Jomed AB, Helsingborg, Sweden) stent placement was evaluated
in 50 patients. Quantitative coronary angiography was performed at baseline, post
stent and 6 months follow-up. Clinical follow-up was done up to 9 months. In 50
patients (38 male/12 female; age 61+/-12 years) with stable (n = 42; 84%) or
unstable (n = 8; 16%) angina, 53 Jostent Flex (JF) stents (diameter 3.2+/-0.2 mm)
were implanted for 51 stenoses. Direct stenting was successful in 46 stenoses
(90%). No stents were lost or damaged when retrieved after unsuccessful direct
delivery. Eventually, all stents could be implanted at the target site.
Angiographic success (<30% residual stenosis) was achieved in 49 lesions (96%).
At 9 months, none of the patients had died. Target lesion revascularization was
necessary in 4 (8%) patients at 6 months and in 2 (4%) other patients between 6
and 9 months. Minimal lumen diameter increased from 1.1+/-0.4 to 2.6+/-0.4 mm
(p<0.001) after stent placement and 1.8+/-0.6 mm (p<0.001) at 6 months follow-up.
Angiographic restenosis (> 50%) at 6 months was present in 24% of 49 treated
stenoses. At 6 and 9 months, 39 (78%) and 41 (82%) of the patients were free of
anginal symptoms and the ischemic event-free survival was 80% at 9 months. This
study demonstrates the safety and efficacy of direct placement of the JF stent as
well as favorable clinical and angiographic results up to 9 months after the
procedure.
PMID- 10785672
TI - Economic outcomes analysis of stenting versus percutaneous transluminal coronary
angioplasty for patients with coronary artery disease in Japan.
AB - The purpose of this study was to compare the clinical outcomes and costs of
coronary stenting with conventional percutaneous transluminal coronary
angioplasty (PTCA) in patients with coronary artery disease (CAD) in Japan. The
increasing use of stent implantation in CAD has raised economic concerns for
healthcare decision makers. This decision analysis model, which applies to the
Japanese healthcare system and uses recent clinical and economic data,
demonstrates coronary stenting to be superior to PTCA, both in terms of
effectiveness and cost. Although the procedural costs for the stenting group are
substantially higher than for PTCA (1,233,412 yen versus 709,295 yen,
respectively; p<0.001), the difference in cost between the two procedures
(524,117 yen) is already reduced to 299,408 yen by the time of hospital discharge
due to procedural complications and associated bail-out treatments avoided during
the in-hospital period. The initial incremental cost of stenting is more than
recouped by the end of year one, mainly because of savings realized due to
avoided repeat revascularization procedures. The cost neutrality (or small cost
saving) is maintained over subsequent years. Thus, coronary artery stenting leads
to better results as well as cost neutrality after one, two and three years. This
highly desirable outcome implies that stenting rather than PTCA alone should be
the treatment of choice and dominant strategy in Japan from the viewpoint of both
the patient and the healthcare system.
PMID- 10785673
TI - Economics and outcomes of coronary stenting: are stents right for everybody?
PMID- 10785674
TI - Is the "direct" approach best?
PMID- 10785675
TI - Coronary radiation therapy with liquid rhenium-186: a first clinical experience.
AB - BACKGROUND: Coronary radiation therapy (CRT) is a new, attractive approach for
the treatment and prevention of restenosis after percutaneous coronary
interventions (PCI). The RadioCath device consists of a standard balloon
dilatation catheter that can be charged with a solution of sodium 186Re
perrhenate, a predominant beta emitter. The safety and performance of this new
device was evaluated in a pilot trial. METHODS AND RESULTS: Thirty-three patients
with a de novo lesion in a native coronary artery were treated with the RadioCath
device after successful angioplasty. The average dwell time to deliver a dose of
20 Gy at 0.5 mm into the vessel wall was 418+/-64 seconds. The treatment was well
tolerated by most of the patients. In 79%, only one inflation cycle was required
to deliver the prescribed dose. There were two procedural device-related
complications (5.9%) and three minor procedural related in-hospital complications
(9%). CONCLUSIONS: CRT using a balloon catheter device, charged with a sodium
186Re perrhenate solution, seems feasible and safe. Clinical and angiographic 6
month follow-up data are pending.
PMID- 10785676
TI - Basal and reserve renal artery blood flow: effect of endothelium-dependent and
independent vasoactive agonists and radiographic contrast medium in two patients.
AB - This manuscript describes the results of invasive testing of renal artery and
arteriolar reactivity in two patients using a panel of endothelium-dependent and
independent agents including radiographic contrast medium. We found that the
renal artery and microcirculation dilate in response to graded acetylcholine
infusions and to bolus nitroglycerin infusion; the renal microcirculation dilates
in response to papaverine but constricts after adenosine and after radiographic
contrast medium. Future indications for this testing are briefly discussed.
PMID- 10785677
TI - Pseudoaneurysm: a late complication of the transradial approach after coronary
angiography.
AB - Percutaneous interventional procedures via the radial artery are now commonplace
and associated with minimal risks. The favorable anatomic relations of the radial
artery to the surrounding structures determine the safety of this approach. The
absence of major nerves and veins in the vicinity of the radial artery makes the
likelihood of arteriovenous fistulas extremely small. We report a case of
pseudoaneurysm of the radial artery, which was only clinically recognized three
months after coronary angiography.
PMID- 10785678
TI - Percutaneous vascular surgery after aortic valvuloplasty: initial clinical
experience.
AB - Percutaneous balloon aortic valvuloplasty can be associated with significant
vascular morbidity. Often, managing the access site prolongs the length of
hospitalization. Three patients were successfully treated with percutaneous
femoral arterial vascular surgery immediately after aortic valvuloplasty. These
patients did not suffer early or late vascular complications. The access site
care was dramatically improved when compared to our usual experience.
PMID- 10785679
TI - Endovascular AAA repair: management strategies for the iliac artery.
PMID- 10785680
TI - Intravascular Ultrasound Assessment of the Mechanisms and Predictors of
Restenosis Following Coronary Angioplasty.
AB - Restenosis occurs after 30% to 50% of transcatheter coronary procedures; its
mechanisms remain incompletely understood. Intravascular ultrasound (IVUS)
studies were analyzed in 360 non-stented native coronary artery lesions in which
follow-up quantitative angiographic and/or IVUS data was available. Pre
intervention, post-intervention, and follow-up, the external elastic membrane
(EEM) and lumen cross-sectional areas (CSA) were measured; plaque + media (P + M
= EEM - lumen CSA), and cross-sectional narrowing (CSN = P + M/EEM CSA) were
calculated. The anatomic slice selected for serial analysis had an axial location
within the lesion at the smallest follow-up lumen CSA. At follow-up, 73% of the
decrease in lumen CSA was due to a decrease in EEM CSA; 27% was due to an
increase in P+M CSA. The change in lumen CSA correlated more strongly with the
change in EEM CSA than with the change in P + M CSA. The change in EEM CSA was
bidirectional; 47 lesions (22%) showed an increase in EEM CSA. Despite a greater
increase in P + M CSA, lesions exhibiting an increase in EEM CSA had (1) no
change in lumen CSA, (2) decreased restenosis, and (3) a 49% frequency of late
lumen gain. The independent clinical, angiographic, and IVUS predictors of
angiographic restenosis (3 50% diameter stenosis at follow-up) were the IVUS
reference lumen CSA, angiographic pre-intervention diameter stenosis, and post
intervention IVUS CSN. Restenosis appeared to be determined primarily by the
direction and magnitude of the change in EEM CSA. An increase in EEM CSA was
adaptive while a decrease in EEM CSA contributed to restenosis. The most powerful
predictor of restenosis was the IVUS post-procedural CSN. The importance of the
post-procedural CSN was related to the change in EEM CSA as a mechanism of
restenosis.
PMID- 10785681
TI - Angiographic Results and Late Clinical Outcomes Utilizing a Stent Synergy (Pre
Stent Atheroablation) Approach in Complex Lesion Subsets.
AB - To investigate the strategy of OdebulkingO in complex lesions before stent
implantation (stent synergy) to improve procedural safety and achieve optimal
acute and long-term results, we reviewed our experience in 389 patients with 504
lesions undergoing a combined stent procedure (45% rotational atherectomy, 24%
laser angioplasty, 20% directional atherectomy, and 11% transluminal extraction
atherectomy before stent implantation). Procedural success was achieved in 94.5%,
with 4% major ischemic complications (1.1% death, 1.9% Q-wave myocardial
infarction, and 2.3% emergency coronary artery bypass surgery). Overall, subacute
stent thrombosis occurred in 1.5% of patients. Target-lesion revascularization
during follow-up was required in 9.8% of the patients. We conclude that a
strategy of selective pre-stent atheroablation in complex lesion subsets results
in excellent procedural outcomes with acceptable complications and favorable long
term results.
PMID- 10785682
TI - Carotid Stent-Assisted Angioplasty: Preliminary Technique, Angiography, and
Intravascular Ultrasound Observations.
AB - Currently, surgical carotid endarterectomy has been the standard therapy for
symptomatic and asymptomatic patients with significant carotid artery stenoses.
However, there are high surgical risk and other patient subsets, wherein a
Olesser invasiveO catheter-based procedure may be worthwhile. Carotid stent
assisted angioplasty (CSSA) is a percutaneous interventional treatment approach
for appropriately selected patients with common and internal carotid artery
lesions. The present report discusses preliminary technique-related,
angiographic, and intravascular ultrasound observations of CSSA. Five symptomatic
patients (with six carotid stenoses) with other co-morbid states were treated by
a multidisciplinary team under the aegis of an approved protocol using
conventional equipment and available Palmaz tubular slotted stents. On-line
quantitative angiography and intravascular ultrasound imaging was performed to
guide stent insertion and monitor results. There were no procedure-related
complications and angiographic results were excellent (final mean diameter
stenosis 5%). Intravascular ultrasound imaging was feasible and safe. In two
cases, the findings obtained from ultrasound images assisted in subsequent
operator decisions. Thus far, there have been no additional clinical sequelae in
these patients (@ 30 days). This preliminary experience with CSSA indicates that
interventional neurovascular therapies may provide a useful alternative for
selected patients requiring endoluminal reconstruction of carotid stenoses.
Extensive additional studies are required to establish the appropriate clinical
application of this technique.
PMID- 10785683
TI - Retrospective Comparison of a Strategy of Primary Coronary Angioplasty versus
Intravenous Thrombolytic Therapy for Acute Myocardial Infarction in a Community
Hospital without Cardiac Surgical Backup.
AB - Recent studies have demonstrated the benefit of primary percutaneous coronary
angioplasty (PTCA) for the emergency treatment of acute myocardial infarction. We
retrospectively examined our experience in performing primary PTCA in a community
hospital without in-hospital surgical backup. Only highly experienced angioplasty
operators participated, and patients were immediately transferred to a tertiary
care referral hospital following primary angioplasty and stabilization. A total
of 102 patients received PTCA at the community hospital during the study period.
Forty received PTCA for cardiogenic shock or for rescue angioplasty. The
remaining 62 patients (the Primary Angioplasty Group) were compared with a
matched group of patients who received thrombolytic therapy during the same time
period (the Thrombolytic Therapy Group). Angioplasty was angiographically
successful in 96% and TIMI-3 grade blood flow was achieved in 85% of patients who
received PTCA. There were no significant differences between the two groups in
terms of in-hospital complications. The duration of hospital stay was
significantly less in the Primary Angioplasty Group as compared with the
Thrombolytic Therapy Group (median = 4 vs. 6 days, p = 0.005), as was the
duration of intensive care unit stay (median 1 vs. 2.5 days, p = 0.001). Thus,
under carefully controlled conditions, primary angioplasty for acute myocardial
infarction in a community hospital without in-hospital cardiac surgery is an
effective and more efficient alternative to thrombolytic therapy.
PMID- 10785684
TI - Percutaneous Inoue-Balloon Mitral Commissurotomy in Patients with Coexisting
Moderate Mitral Regurgitation, and Severe Subvalvular Disease and/or Mitral
Calcification.
AB - The present study examined the safety and immediate and late outcome of 12
patients with coexisting moderate (angiographic grade 2+) mitral regurgitation
and significant subvalvular disease and/or calcified mitral valves (group 1)
after percutaneous balloon mitral commissurotomy (BMC) and compared the results
with 64 patients without these adverse valve features (group 2). BMC produced a
significantly smaller echocardiographically determined mitral valve area
improvement in group 1 compared with group 2 (from 0.7 +/- 0.2 cm2 to 1.3 +/- 0.3
cm2 vs. 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2, respectively, p < 0.05). Similarly,
compared with group 2, less patients in group 1 obtained an optimal valvuloplasty
outcome defined as a 3 50% increase in mitral valve area or a final valve area of
3 1.5 cm2 without final 3 3 grade angiographic mitral regurgitation (75% vs. 95%,
p < 0.05). There was, however, no severe (3 angiographic grade 3+) mitral
regurgitation in group 1 compared with 1 in group 2 (p = NS). At a mean follow-up
of 19 +/- 14 months, there were no deaths or strokes. Restenosis was noted in 4
patients; 3 in group 1, and 1 in group 2. We conclude that BMC is safe and
effective in patients with pre-existing moderate mitral regurgitation and severe
subvalvular disease and/or significant mitral calcification with minimal risk of
creating severe mitral regurgitation. The valve area improvement was, however,
substantially smaller and the restenosis rate higher than those without moderate
mitral regurgitation and favorable valve anatomy.
PMID- 10785685
TI - Exogenous Fibronectin to Prevent Neointimal Hyperplasia after Balloon
Angioplasty.
AB - This study examined the effect of fibronectin to prevent restenosis in a
microswine model after balloon angioplasty of the right iliac artery. Immediately
following angioplasty, fourteen hypercholesterolemic microswines were randomized
to receive fibronectin (223.5 mg, n = 8) or saline containing albumin (75.6 mg, n
= 6). At 60-days post-angioplasty, the angioplasty-injured and intact
contralateral arteries were examined with angiography and histopathology. With
angiography, there was no significant difference in the luminal diameters of
angioplasty arteries compared with the intact contralateral vessels. Histological
examination of angioplasty-injured vessels showed neointimal hyperplasia. The
intimal areas of angioplasty-injured vessels, in the placebo and fibronectin
groups, were much larger than the areas of their contralateral vessels
(fibronectin 287 +/- 160 vs. 138 +/- 88 um2, p = 0.018; and the placebo (1,245 +/
1,567 vs. 248 +/- 219 um2, p = 0.041). Mean total cholesterol levels of both
groups were maintained at levels > 400 mg/dl throughout the study period.
CONCLUSION: At sixty days after balloon angioplasty injury: 1) fibronectin did
not only not prevent neointimal hyperplasia, in some animals, it increased
neointimal growth; and 2) angiographic results were not sensitive enough to
quantify changes observed in histologic findings.
PMID- 10785686
TI - Bail-Out of Stent Jail: Stent Delivery Through Stent Struts.
AB - Stent deployment in a lesion with a large side branch is an example of the
potential limitation of intracoronary stents, especially the Palmaz-Schatza stent
with its tubular slotted design. This case study describes a patient in whom a
Palmaz-Schatz stent of excessive length covered the origin of a side branch
(Ostent jailO). Thrombus developed in the jailed branch as well as in the main
vessel, causing abrupt vessel closure and impending acute myocardial infarction
within one hour after the procedure. This complication was successfully managed
by emergency repeat angioplasty and implantation of a Micro Stenta on both
branches, i.e. in the main vessel distal to the Palmaz-Schatz stent and in the
side branch through the struts of the Palmaz-Schatz stent.
PMID- 10785687
TI - Right Ventricular Pseudoaneurysm Following Endomyocardial Biopsy.
AB - Ventricular perforation is an unusual complication after endomyocardial biopsy in
heart transplanted patients. We report a case of asymptomatic right ventricular
perforation and pseudoaneurysm formation, secondary to endomyocardial biopsy,
diagnosed by angiography. The spontaneous obliteration of the pseudoaneurysm was
observed.
PMID- 10785688
TI - Rotational Atherectomy for Resistant Anastomotic Saphenous Vein Bypass Graft
Stenosis.
PMID- 10785689
TI - Invasive Electrophysiologic Procedures at Peripheral Medical Sites.
PMID- 10785690
TI - The Evolving Health Care System and Managed Care: The Effects on the Field of
Electrophysiology.
PMID- 10785691
TI - Data Management, Outcomes Assessment and Information in Cardiovascular Practice.
PMID- 10785692
TI - Practice Management Polonaise: A Work in Progress.
PMID- 10785693
TI - Acute Luminal Gain after Stenting: Comparison of Gianturco-Roubin and Palmaz
Schatz Stents.
AB - The Gianturco-Roubin stent has an open coil structure with a clamshell
configuration and a relatively large distance between its transversely parallel
struts. This stent design results in a low metallic surface area but may possibly
also lead to more vessel recoil and less acute luminal gain than that obtained
with the more rigid Palmaz-Schatz stent. The present study compares the acute
angiographic results obtained with both stents. Quantitative coronary
arteriography was performed in 77 patients in whom one of the following was
successfully implanted: 1) a Palmaz-Schatz stent (n = 27), 2) a normally sized (n
= 25) Gianturco-Roubin stent (n = 25), 3) a one-size oversized Gianturco-Roubin
stent (n = 30). Diameter stenosis after stenting was greater in the patients with
a normally sized Gianturco-Roubin stent (28 +/- 2%) than in those with a Palmaz
Schatz stent (18 +/- 1.2%, p < 0.05). This difference was in part attributed to a
more important acute luminal loss due to elastic recoil and plaque protrusion
with Gianturco-Roubin stents (25 +/- 2%) compared with Palmaz-Schatz stents (11
+/- 1.5%, p < 0.0001). However, in the patients with an oversized Gianturco
Roubin stent acute gain was similar to that obtained with Palmaz-Schatz stents
(50 +/- 3.2% vs. 48 +/- 3%, p=0.68) and residual stenosis (20 +/- 2%) was less
than that with a normally sized Gianturco-Roubin stent (p < 0.05). In the
patients with an oversized Gianturco-Roubin stent the actual size during
deployment (109 +/- 2.9% of the reference diameter) was smaller than the nominal
size (122 +/- 1.7%). Thus, one-size oversizing of the Gianturco-Roubin stent
corrects for the smaller actual than nominal diameter of this stent. It also
compensates for the greater recoil observed with this stent and leads to similar
acute diameter gain as that obtained with a Palmaz-Schatz stent without causing
an excessive coronary artery stretching.
PMID- 10785694
TI - Quality Determining Parameters of Balloon Angioplasty Catheters.
AB - The investigations carried out on balloon angioplasty catheters using a parameter
test unit allow an objective comparison and a qualitative assessment of catheter
brands with respect to their stenosis passability. The design of the test unit
allows the measure of other parameters important for clinical practice, such as
pushability and trackability. Altogether 8 over-the-wire and 10 monorail
catheters from 7 different manufacturers were investigated by our study. Between
modern over-the-wire and monorail systems there exists no fundamental difference
in passage capability. In some brands of catheter the stenosis model shows no
increase in the amount of thrust required, even after repeated inflation; this is
accountable to the good folding properties of the balloon. Angioplasty balloons
made of less overstretchable or thinner material yielded the best results. The
fact that changes in balloon quality may result from pre-inflation should carry
weight in discussions concerning the reuse of catheters. The measurement results
are useful for the correct selection of a catheter appropriate to the therapy
task at hand.
PMID- 10785695
TI - The Utility of Unipolar Electrogram Recording for Catheter Ablation of Accessory
Pathways During Atrial Fibrillation.
AB - INTRODUCTION: Atrial fibrillation, a commonly occurring rhythm in patients with
manifest accessory pathways, may prevent the usual mapping criteria for
successful catheter ablation from being obtained. Unipolar electrogram recordings
may be of value in this situation. METHODS: Unipolar recordings were obtained
during atrial fibrillation in one patient with a manifest left-sided accessory
pathway, and another patient with a septal accessory pathway with Mahaim-like
properties. The timing of the intrinsic deflection, and the presence of a QS
complex, were utilized as criteria to define the successful ablation site.
RESULTS: Successful ablation of the accessory pathways was achieved during atrial
fibrillation. CONCLUSIONS: The use of unipolar recordings can aid successful
catheter ablation of the accessory pathways during atrial fibrillation, giving
added information to the bipolar electrograms.
PMID- 10785696
TI - Balloon Angioplasty of Lesions Beyond Extremely Angulated Bends.
AB - Angioplasty of stenosis beyond severely angulated bends (acute angle less than
60!) can be technically difficult. In addition to the difficulty traversing these
severe bends with a guidewire, once crossed, even the lowest profile over-the
wire balloon catheter may not advance around these severe angulations. The
utility of fixed-wire balloon catheters is often limited by prolapse of the
distal wire tip. We describe a technique of shaping a fixed-wire balloon catheter
to prevent wire prolapse while traversing severely angulated bends and its
successful use in two consecutive cases where conventional methods failed.
PMID- 10785697
TI - Myocardial Bridging May Predispose to Coronary Perforation During Rotational
Atherectomy.
PMID- 10785698
TI - Balloon Mitral and Aortic Valvuloplasty in Mirror-Image Dextrocardia.
AB - Three patients of mirror-image dextrocardia were subjected to balloon
valvuloplasty at our institute. One patient had severe pliable rheumatic mitral
stenosis (MS), another had severe calcific rheumatic MS and the third had
moderate rheumatic MS and severe rheumatic aortic stenosis (AS). Necessary
modifications in the standard septal puncture technique, Inoue mitral
valvuloplasty technique, and Cribier aortic valvuloplasty technique were done
keeping unusual anatomy of mirror-image dextrocardia in account to dilate mitral
and aortic stenosis successfully. Acute hemodynamic results were satisfactory and
no complications encountered. This report illustrates feasibility and safety of
balloon mitral and aortic valvuloplasty in the complex cardiac anatomy of situs
inversus totalis.
PMID- 10785699
TI - Evaluation of a New Approach for Perfusing Myocardial Tissue.
PMID- 10785700
TI - Selection of a Consultant for Your Cardiovascular Practice N Caveat Emptor.
PMID- 10785701
TI - Stenting of the Infarct-Related Artery During Complicated Angioplasty in Acute
Myocardial Infarction.
AB - The aim of this study was to assess safety and efficacy of coronary stenting as a
strategy for improving PTCA suboptimal angiographic result. From March 1993 to
December 1995, 104 patients underwent PTCA during acute myocardial infarction.
Unplanned coronary stenting was required in 66 pts (63.5%). Procedural success
was obtained in 64 pts (97%). Two patients had an unsuccessful stenting
procedure: one patient for a suboptimal stent deployment and another for LAD
reocclusion requiring emergency CABG (1.5%). Palmaz-Schatz stents were used in 60
pts (91%) and AVE micro-stent in 6 pts (9%). During the hospital course, subacute
reocclusion of the vessel occurred in 3 pts (4.6%); one patient underwent a
successful rePTCA while the other two underwent CABG. Two patients had vascular
groin complications requiring surgical repair of the femoral artery. During
hospitalization, one patient underwent elective CABG for early residual
myocardial ischemia. At seventy-two hours from PTCA, one patient (1.5%) died as a
result of intestinal infarct. Six months survival rate was 98.3% for 59 pts
discharged alive from our department. Ten pts were symptomatic during the follow
up: One patient underwent PTCA on another vessel and the other underwent CABG for
a multivessel disease. CABG was used in one patient who presented residual silent
ischemia in multivessel coronary artery disease. At six months, the first group
of patients (18 pts) underwent planned coronary angiography: Vessel patency was
present in 17 patients. One patient had an asymptomatic reocclusion of the
treated vessel. This study shows a good angiographic result obtained with
intracoronary stenting during primary or rescue PTCA of the infarct-related
artery. It does not appear to increase major in-hospital adverse events and may
reduce the need for surgical revascularization, reducing in-hospital mortality
rate and favorably affecting LVEF.
PMID- 10785702
TI - Palmaz-Schatz Coronary Stent Implantation Without Intravascular Ultrasound and
Without Subsequent Anticoagulation: Clinical Outcome.
AB - OBJECTIVES: To determine the safety and efficacy of antiplatelet therapy alone in
a selected group of patients following coronary stenting. BACKGROUND: Coronary
stent implantation is an effective treatment for abrupt closure, and can also
reduce the restenosis rate following percutaneous transluminal coronary
angioplasty. However, anticoagulation therapy following stent implantation is
associated with a significant incidence of vascular complications and subacute
stent thrombosis. METHODS: Between February and November 1994 we implanted 62
Palmaz-Schatz stents in 50 patients with an optimal angiographic result following
stent deployment. In these patients, intravascular ultrasound was not used, and a
regimen of aspirin 100 mg daily indefinitely and ticlopidine 250 mg twice daily
for 3 months was started without anticoagulation. RESULTS: Of these 50 patients
(10 females : 40 males, mean age 63 +/- 12 years, LVEF 64 +/- 10%), 39 (78%) were
stented for a suboptimal angiographic result post angioplasty, 2 (4%) received
stents as a bailout procedure, and 9 (18%) were stented electively. Average
hospital stay following stent implantation was 3.7 +/- 3.0 days. After a mean
follow-up period of 140 +/- 70 days, there were no instances of stent occlusion,
death, stroke, need for coronary bypass surgery, Q-wave myocardial infarction or
femoral artery pseudoaneurysm. There was 1 case (2%) of significant puncture site
hemorrhage. CONCLUSIONS: Immediate angiographic appearance after stent
implantation can be used to define patients at low risk of stent thrombosis who
do not require anticoagulation and can safely be discharged early from the
hospital.
PMID- 10785703
TI - Gender Differences in Patients Referred for Electrophysiology Procedures.
AB - Gender differences are prevalent in cardiology and particularly in patients who
have undergone coronary artery bypass surgery and percutaneous transluminal
coronary angioplasty. The purpose of this study was to determine whether similar
gender differences are present in electrophysiology. Eight-hundred seventy-three
patients were identified from the OEP ManagerO database over approximately a two
year period at North Shore University Hospital. Overall, the majority of patients
referred for invasiveive electrophysiology procedures were men (67 percent). A
higher percentage of men had coronary disease despite the type of study/implant.
There was a relatively equal distribution of men and women who underwent head-up
tilt table testing (47 and 53 percent respectively). We conclude that gender
differences are present in electrophysiology studies and that further studies are
necessary to determine whether a bias exists in this field.
PMID- 10785704
TI - Dislodgement of Intracoronary Thrombus During Angiography in a Patient with
Unstable Angina Pectoris.
AB - A patient with unstable angina pectoris in whom thrombus release from
intracoronary lesion was seen during angiography is described. The event resulted
in improvement of vessel patency and resolution of ischemic symptoms. To our
knowledge, only two similar cases have been reported in English literature since
1966.
PMID- 10785705
TI - Congenital Left Ventricular Septal Diverticulum: Angiographic Recognition and
Clinical Significance.
PMID- 10785706
TI - Coronary Stenting in Vessels with Marked Proximal Tortuosity Using a Sport Wire:
Advantages and Pitfalls.
AB - In this report two patients are described in whom successful deployment of a
coronary stent was achieved in a very tortuous coronary artery. Deployment was
performed using a special extra-support wire that straightened the proximal
segment of the artery and provided the support for stent advancement. The
mechanical straightening of the artery induced marked narrowing that did not
respond to intracoronary nitroglycerin but disappeared after withdrawal of the
wire.
PMID- 10785707
TI - Strategy Retreat N An Important Tool for Your Practice.
PMID- 10785708
TI - Sonographic and Angiographic Features of Intramural Hematoma as a Cause of Failed
Coronary Angioplasty.
AB - A characteristic feature of a specific type of dissection after PTCA was observed
in seven cases with severe obstruction of the vessel segments proximal and/or
distal to the dilatation site. The underlying cause in the absence of an
angiographically visible dissection flap was revealed by intravascular
ultrasound. The obstruction was caused by an extraluminal obstruction by an
echodense mass increasing in size with time, and without a dissection flap even
as assessed by intravascular ultrasound. This phenomenon was interpreted as an
intramural hematoma extending between media and adventitial border of the vessel.
In six of seven cases, bailout therapy by either stenting or redilatation and
creation of a typical dissection flap relieved the vessel obstruction. In one
case of extension of the hematoma into the left main coronary artery, CABG was
performed. Intravascular ultrasound provided a conclusive insight into the
underlying morphology of failed PTCA in cases without angiographic features of a
dissection. It helped in deciding and controlling the bailout strategy, which was
the stenting of the entry into the hematoma at the initial dilatation site.
PMID- 10785709
TI - Local Angiopeptin Delivery Using Coated Stents Reduces Neointimal Proliferation
in Overstretched Porcine Coronary Arteries.
AB - BACKGROUND: Systemic administration of angiopeptin has been shown to inhibit
myointimal thickening after arterial injury in several animal species. METHODS
AND RESULTS: To explore to what extent high and long-lasting local concentrations
of angiopeptin influence the healing process after vascular injury, tantalum
balloon-expandable stents were first coated with a polymer loaded with
angiopeptin 250 ug. Implantation of these stents in porcine coronary arteries
resulted in tissue concentrations of 10.7 pg/ml wet weight in the stented
arterial segment 24 hours after stent implantation, gradually declining to 2.0
pg/ml wet weight at day 8. Finally, 20 pigs were randomly treated with either an
angiopeptin-loaded or a blank-coated stent. At baseline, the angiographic
parameters were similar between both groups but, after 6 weeks, the minimal
luminal diameter of the stented arterial segment was larger in the angiopeptin
treated pigs when compared to controls (2.20 +/- 0.57 mm vs 1.57 +/- 0.68 mm, p <
0.01) This angiographic finding was confirmed by post-mortem morphometry where
the respective lumen area values were 1.00 +/- 0.54 mm2 and 0.43 +/- 0.28 mm2 (p
< 0.01). CONCLUSION: Polymer coated stents can be loaded with angiopeptin, which
after implantation in porcine right coronary arteries result in high local tissue
concentrations gradually declining over more than 8 days. These high local
concentrations inhibit myointimal proliferation induced by
poly(organo)phosphazene coated overstretched stents.
PMID- 10785710
TI - Usefulness of Renal Arteriography Following Coronary Angiography.
AB - PURPOSE: To determine the usefulness of renal angiography in patients that
underwent coronary angiography because of clinically suspected coronary artery
disease. METHODS: Selective arteriography of the renal arteries was performed in
205 patients (mean age 60 +/- 8 years; 80% males) at the time after coronary
angiography with the use of right coronary Judkins catheter. RESULTS: Two-hundred
renal angiographies were judged technically adequate. Average additional
fluoroscopy time was 3 +/- 2 min and 30 +/- 8 ml of additional contrast medium
was used. Coronary artery disease (3 50% narrowing) was found in 158 (79%). Renal
arterial disease was found in 17 (8.5%) patients. Reduction in lumen diameter was
< 50% in 11 patients (5.5%) including 3 patients with bilateral stenosis, and 3
50% in 6 patients (3%). The only clinical variable associated with renal artery
stenosis was peripheral vascular disease. CONCLUSION: There is no justification
for doing routine renal angiography for patients undergoing coronary
arteriography because the prevalence of severe renal artery stenosis is low.
PMID- 10785711
TI - Rate-Responsive Pacing Mimicking Ventricular Tachycardia.
AB - We describe 2 patients with rate-responsive permanent ventricular pacemakers who
developed upper rate pacing while at rest. In one patient this occurred during
chest physiotherapy and in the other as a result of muscle fasciculations. In
both cases, the paced rhythm was misdiagnosed as ventricular tachycardia.
Reprogramming of the pulse generators prevented further inappropriate rapid
pacing.
PMID- 10785712
TI - Rescue AVE Stent Placement for Left Anterior Descending Coronary Artery Occlusion
During Diagnostic Angiography.
AB - In a 65-year-old male with coronary artery disease a proximal occlusion of the
left anterior descending coronary artery occurred during diagnostic coronary
angiography. The most likely cause was an occlusive dissection. This resulted in
acute myocardial ischemia and immediate cardiogenic shock. The decision was made
to proceed to emergency percutaneous transluminal coronary angioplasty (PTCA).
After balloon dilatation, a 3.5 mm AVE stent was deployed successfully at the
site of the lesion. This resulted in a satisfactory angiographic result and an
immediate improvement of the clinical picture. We conclude that placement of an
AVE stent can provide a means for restoring flow in case of acute occlusive
dissection during coronary angiography.
PMID- 10785713
TI - TEC Before Stenting in Acute Myocardial Infarction.
PMID- 10785714
TI - Five Not So Easy Pieces N The Business of Practice Mergers and Acquisitions.
PMID- 10785715
TI - Intracoronary Stenting for Restenosis: Long-Term Follow-up: A Single Center
Experience.
AB - One-hundred thirteen stents (78 Wallstents, 29 Palmaz-Schatz and 6 Wiktor) were
implanted in 106 patients aged 63 +/- 5 years to treat a restenosis following
previous angioplasty in a native coronary artery (86 cases) and in a venous graft
(20 cases). Implantation was technically possible in all cases. The native
vessels had a mean reference diameter of 3.3 +/- 0.3 mm and their mean minimal
lumen diameter increased from 1.2 +/- 0.3 mm before angioplasty to 2.8 +/- 0.8
after stent implantation. The venous grafts mean reference diameter was 4.4 +/-
0.7 mm and their mean minimal lumen diameter increased from 1.3 +/- 0.4 mm before
angioplasty to 4.0 +/- 0.7 mm after implantation. Percentage stenosis in the
native arteries and in the venous grafts were respectively 78 +/- 13% and 69 +/-
14% before angioplasty and 24 +/- 8% and 22 +/- 8% after stent implantation.
Complications at 6 months, presented as a ranking scale with 100% follow-up rate
were, overall, of 20% clinical events (4% deaths, 6% myocardial infractions, 2%
coronary artery bypass grafting and 8% re-angioplasty). Angiographic
complications were of 8% subacute thrombosis and 19% restenosis and chronic
occlusions. Long-term, at 65 +/- 9 months, clinical (86% follow-up) and
angiographic (74% follow-up) showed that only a further 9% clinical events and
14% restenosis (12% of them between 6 and 12 months) occurred after 6 months. At
an estimated follow-up time of 104 months, 70% patients remain event-free and the
survival rate is 95%. In conclusion, stent implantation in the treatment of
restenosis following conventional balloon angioplasty is a valid strategy with
good long-term results.
PMID- 10785716
TI - Primary PTCA in a Rural Hospital.
AB - The results of primary percutaneous transluminal coronary angioplasty (PTCA) to
treat patients with acute myocardial infarction in a rural hospital were
reviewed. Thirty-five patients presenting with acute myocardial infarction,
including 40% considered high risk, were treated using the strategy of primary
angioplasty. Following cardiac catheterization, two patients were found to have
anatomy deemed unsuitable for primary angioplasty and subsequently underwent
urgent coronary artery bypass graft (CABG) surgery. Thirty-three patients
underwent primary angioplasty with a procedural success rate of 94%. Procedural
success was defined as reduction of the infarct arteries stenosis to less then
50% and the establishment of TIMI-III flow. Six percent of these patients
required urgent CABG surgery because of unsuccessful angioplasty. In-hospital
cardiac mortality was 3%. Six month follow-up was achieved for all patients.
There were no cardiac deaths following hospital discharge. Recurrent ischemia
occurred in 17% of the patients. Favorable in-hospital and late results were
achieved. This review indicates that the strategy of primary angioplasty to treat
myocardial infarction may be successfully applied in a rural setting.
PMID- 10785717
TI - Coronary Angioplasty in the Treatment of Post-Cardiac Transplant Coronary Artery
Disease.
AB - Accelerated coronary disease following cardiac transplantation is an important
obstacle to long-term survival and its management is not well defined. Coronary
angioplasty has been proposed as a palliative treatment in some patients with
discrete proximal lesions. Of 172 patients who underwent cardiac transplantation
between April 1983 and November 1995, 8 underwent subsequent coronary angioplasty
of 11 lesions. The majority was performed in asymptomatic patients, 5 for
angiographic abnormalities alone, and 3 for documented painless ischemia. Primary
angiographic success was obtained in 91% (10/11) of lesions dilated.
Complications included 1 acute occlusion and 1 arteriovenous fistula. Three
patients died, 1, 8 and 10 months after angioplasty. After an average of 36-month
follow-up, 4 (out of 8) patients had no cardiac event (myocardial infarction,
second angioplasty, retransplantation or death). Thus, coronary angioplasty can
be performed with acceptable risk in selected patients with cardiac
transplantation.
PMID- 10785718
TI - Intravascular Stenting in a Female Patient with Spontaneous Coronary Dissection
and Von WillebrandOs Disease.
AB - We report a case of spontaneous coronary dissection occurring in a 46-year-old
women affected by von WillebrandOs disease presenting with anterior myocardial
infarction. The patient was treated with thrombolytic therapy and stent
implantation. We believe that in patients with single vessel spontaneous coronary
dissection and unstable clinical condition, coronary stenting may provide an
alternative treatment in place of coronary surgery.
PMID- 10785719
TI - Spontaneous Resolution of Pseudo-Narrowing After Coronary Artery Stenting.
AB - Pseudo-narrowings are due to straightening effect of the guidewire on a tortuous
portion of the coronary artery. We described a case of its occurrence after
deployment of intracoronary stents which persisted after withdrawal of the
guidewire and balloon into the guiding catheter. Spontaneous resolution occurred
within 4 weeks of the procedure.
PMID- 10785720
TI - Stent Placement for Coronary Artery Disease in a Cardiac Transplant Patient.
PMID- 10785721
TI - Tracking Market Movement to Managed Care.
PMID- 10785723
TI - Transcatheter Occlusion of Patent Ductus Arteriosus: State of the Art.
PMID- 10785722
TI - Successful Radiofrequency Catheter Ablation in a Patient with Wolff-Parkinson
White Syndrome after Unsuccessful Surgical Repair.
AB - Radiofrequency catheter ablation has found wider applications for the treatment
of supraventricular and ventricular tachycardias. We present a case report of a
30-year-old woman with a history of Wolff-Parkinson-White syndrome and surgical
excision of both septal and paraseptal accessory pathways. Five years post
surgery, she presented with recurrent supraventricular tachycardia. Subsequently,
she underwent successful radiofrequency catheter ablation of a right posterior
septal accessory pathway. After 1.8 seconds of 20 watts of radiofrequency energy
delivered to the right posteroseptal region (coronary sinus os), orthodromic
supraventricular tachycardia was terminated. After completion of a full
100Dsecond application, there was no evidence of either manifest or concealed
accessory pathways, and no supraventricular tachycardia upon restudy. This study
emphasizes the ease and facility of the percutaneous catheter ablation techniques
that are now employed as compared to the open chest surgical approach.
PMID- 10785724
TI - Transcatheter Closure of Atrial Septal Defects: Role of Buttoned Devices.
PMID- 10785726
TI - Should Balloon Angioplasty be Used as a Treatment of Choice for Native Aortic
Coarctations?
PMID- 10785725
TI - Balloon Dilatation of Discrete Membranous Subaortic Stenosis.
PMID- 10785727
TI - Role of Stents in the Management of Congenital Heart Defects.
PMID- 10785728
TI - Critical Pulmonary Stenosis in the Neonate: Role of Transcatheter Management.
PMID- 10785730
TI - Ultrasound as an Adjunct to Cardiac Interventions in Pediatric Patients.
PMID- 10785729
TI - Coil Embolization in the Management of Cardiac Problems in Children.
PMID- 10785731
TI - Is Unstable Angina a Contraindication to Intracoronary Stent Insertion?
AB - BACKGROUND: Percutaneous transluminal coronary angioplasty is associated with
higher rates of acute complications and restenosis when performed in the clinical
setting of unstable angina. Coronary stent insertion has been shown to reduce
restenosis when performed electively. The effect of unstable angina on clinical
outcome after stent deployment is currently unclear. OBJECTIVE: To compare the
clinical outcome after coronary stents inserted in patients with unstable and
stable angina. DESIGN: A retrospective analysis of all patients receiving Palmaz
Schatz stents electively or for sub-optimal angioplasty result in patients with
stable and unstable angina. PATIENTS: One-hundred fifty-seven patients received
178 Palmaz-Schatz stents electively or for the treatment of sub-optimal result.
Thrombolysis in Myocardial Infarction Study (TIMI) grade 3 flow was present in
all patients at the time of stent delivery. Unstable angina was defined as pain
at rest despite anti-anginal therapy (Braunwald class II, III). Eighty-three
patients (mean age 58 years) with unstable angina received 95 stents and 74
patients (mean age 57 years) with stable angina received 83 stents. MAIN OUTCOME
MEASURES: Subacute stent thrombosis (SAST), myocardial infarction (MI), need for
repeat angiography, coronary bypass graft surgery (CABG) and death. RESULTS: The
early complications (within 2 weeks) comparing the unstable and stable groups
respectively were: No deaths, SAST 3/83 (3.6%) vs. 2/74 (2.7%), MI 2/83 (2.4%)
vs. 2/74 (2.7%) and CABG 6/83 (7.2%) vs. 2/74 (2.7%). After 2 weeks no patient
had a MI or CABG. Clinical follow-up was continued up to 6 months. Two patients
in each group had repeat angiography for recurrent symptoms. One patient in the
stable group died from non-cardiac causes. CONCLUSIONS: There appears to be no
difference in the early or late clinical outcome of patients with unstable or
stable angina treated with coronary stent insertion when TIMI flow is normal at
the time of stent insertion.
PMID- 10785732
TI - Experimental Evaluation of a New Single Wire Stainless Steel Fishscale Coronary
Stent (Freedoma).
AB - Recent randomized clinical trials revealed a significant reduction in
angiographic restenosis rates when adjunctive stenting was performed after
conventional coronary balloon angioplasty. Current approved coronary stents are
however hampered by their rigidity, limiting their trackability in tortuous
vessels and furthermore, needing high pressure deployment for optimal vessel
apposition. New coronary stents are currently under development, using more
biocompatible metal alloys and/or designs which better align to the vessel wall
at moderate deployment pressures. We evaluated the safety, efficacy, angiographic
and histological effect of a new stainless steel fishscale designed stent
(Freedoma, Global Therapeutics, Co., USA) in a porcine coronary and peripheral
artery model. Implantation in the right coronary artery was successful in all 20
pigs. Control angiograms at 6 weeks follow-up demonstrated patent vessels and
morphologic evaluation showed only a mild fibromuscular neointimal response
resulting in an area stenosis of 28.7 +/- 0.18% and a mean neointimal hyperplasia
of 0.18 +/- 0.25 mm. Comparison with the Palmaz-Schatza coronary stent in a
porcine peripheral artery model demonstrated similar quantitative angiographic
and morphologic vessel analysis results. Also the morphometric data were
comparable. Area stenosis: Palmaz-Schatz: 37 +/- 0.24%, Freedom: 21 +/- 0.14%, p
= 0.07. Mean neointimal hyperplasia: Palmaz-Schatz: 0.33 +/- 0.24 mm, Freedom:
0.18 +/- 0.08 mm, p = 0.08. CONCLUSION: Freedom coronary stent implantation in a
porcine model resulted in a high procedural success without subacute thrombotic
occlusions, despite no further anticoagulation nor antiplatelet therapy. Six
weeks histopathological and morphometric evaluation demonstrated only a mild
fibromuscular neointimal hyperplasia.
PMID- 10785733
TI - QT Dispersion: Current and Future Clinical Role.
AB - QT dispersion calculated from the standard 12-lead ECG has emerged as a
noninvasiveive measurement of the degree of inhomogeneity in myocardial
repolarization. The studies evaluating predictive value of QT dispersion for
identification of patients at increased risk for serious ventricular arrhythmias
and sudden cardiac death have been conducted in multiple disease states and show
promising results. This review focuses on the conceptual evolution, currently
accepted methodology, and clinical and research applications of QT dispersion
measurements.
PMID- 10785734
TI - Intracoronary Stent Used in a Transplanted Heart.
AB - The development of occlusive cardiac allograft vasculopathy is different from
coronary artery disease in native vessels and treatment is still an unsettled
problem. We describe a case of a 53-year-old male who underwent heart
transplantation because of severe dilated cardiomyopathy. Based on myocardial
ischemia, coronary angiography was performed six years later. Significant two
vessel coronary artery disease had developed and was treated by coronary
angioplasty. Due to a suboptimal result, a Palmaz-Schatz stent was successfully
implanted in the left anterior descending artery. The patency of the stent was
demonstrated by ultrafast computed tomography and confirmed by control
angiography three months later.
PMID- 10785735
TI - Inoue-Balloon Pulmonary Valvuloplasty Using a OFree-FloatO Technique.
PMID- 10785736
TI - ItOs Not the Money N ItOs the Money!
PMID- 10785737
TI - The Philosophy of Physician Compensation During the Transition to Capitated Care.
PMID- 10785738
TI - Characteristics of an Ideal Stent Based Upon Restenosis Pathology.
PMID- 10785739
TI - Restenosis after Angioplasty N An Update on Relevant Animal Models.
PMID- 10785740
TI - Local Drug Delivery: The Development of a Drug Delivery Stent.
PMID- 10785741
TI - Local Drug Delivery for the Treatment of Thrombus and Restenosis.
PMID- 10785742
TI - Successful Coronary Interventions Performed with Argatroban Anticoagulation in
Patients with Heparin-Induced Thrombocytopenia and Thrombosis Syndrome.
AB - Patients with heparin-induced thrombocytopenia and thrombosis syndrome (HITTS)
frequently have coincident vascular disease. Patients with HITTS who require
vascular procedures have often been excluded from vascular intervention because
intravascular procedures require heparin. Re-exposure to heparin places these
patients at great risk for reactivation of thrombosis related to HIT antibody. We
present our initial experience with an alternative anticoagulant to heparin,
argatroban in patients with HIT antibody who underwent 14 coronary interventions.
All 14 coronary lesions were treated successfully and no patient suffered an
HITTS-related or an argatroban-related complication.
PMID- 10785743
TI - Clinical and Angiographic Experience with Coronary Stenting Using Freedoma Stent.
AB - The immediate safety and efficacy and the 6 month clinical and angiographic
follow-up of a new fish-scale designed coronary coil stainless steel stent
(Freedoma) was assessed by a prospective study. During 1995, 169 patients were
treated on 177 vessels using 233 Freedom stents. Procedural indication for
stenting was a bail-out situation in 79 vessels, a suboptimal angioplasty result
in 62 vessels and a third restenosis after PTCA in 36 vessels. Procedural success
was achieved in 170 vessels (96%); in 162 patients (96%). Subacute thrombotic
occlusion occurred in one patient (0.6%). Acute myocardial infarction occurred in
7 patients (4.1%). Bleeding complications, necessitating blood transfusion
occurred in 6 patients (3.6%). There were two non-stent related deaths.
Recurrence of stent-related angina pectoris and/or a positive stress test
occurred in 10 pts (6.4%). Elective control angiography at 6 months was performed
in the first 85 patients. Stent restenosis of 3 50% diameter stenosis was found
in 14 patients (16.5%).
PMID- 10785744
TI - Intracoronary Stent Placement without Coumadin or Intravascular Ultrasound.
AB - Coronary stenting has been associated with the need for intravascular ultrasound,
increased anticoagulation, and increased length of stay. We evaluated the use of
ticlopidine and aspirin without ultrasound in 322 consecutive patients from
February 1995 through January 1996 who underwent intracoronary stenting with
adjunctive high pressure balloon angioplasty [mean peak atmospheres (ATM) = 15.9;
mean post-dilating balloon size = 3.4 mm]. Unstable coronary syndrome was the
admitting diagnosis in 66% of these patients. Post-stent anticoagulation
consisted of overnight heparin, followed by aspirin (325 mg daily) and
ticlopidine (250 mg twice daily) for 4 to 6 weeks. Among the 322 patients, 575
stents (Palmaz-Schatz Coronary Stents = 530; Palmaz-Schatz Biliary Stents = 33;
Gianturco-Roubin Stents = 12) were implanted in 338 coronary vessels (native
arteries = 316; saphenous vein grafts = 22). Twenty-three patients (7%) had multi
vessel stenting. Average length of stay following stenting was 1.6 days (average
overall hospital length of stay was 2.3 days), and 71% of patients were
discharged the next day. Follow-up of all 322 patients was performed by telephone
contact at least 30 days after discharge. During this period 1 (0.3%) acute
thrombosis and no subacute thrombosis occurred. In this series of patients,
coronary stent implantation using routine high pressure balloon post-dilatation N
without intravascular ultrasound N and a combination of aspirin and ticlopidine
was performed with no subacute thrombosis and a short length of stay.
PMID- 10785746
TI - Late Coronary Dissection Induced by a Coronary Stent: A Word of Caution about
Long-Term Effects of Coronary Stents.
PMID- 10785745
TI - Percutaneous Transluminal Coronary Angioplasty Through 5 French Diagnostic
Catheters.
AB - In 130 patients, coronary angioplasty (PTCA) with fixed wire balloons through 5
French (F) diagnostic catheters was performed immediately following diagnostic
coronary angiography. Patients with complex lesions or in whom the need for
alternative devices was likely such as stents were excluded. A total of 151
lesions were attempted. Primary success with 5F systems was achieved in 92% of
lesions. In 7 cases, the 5F system failed to cross the stenosis and a change to a
larger guiding catheter was necessary. Of these 7 cases, 6 could be dilated
successfully with 6 or 7F systems. In one patient in whom the fixed wire balloon
was not able to cross a subtotal stenosis of an obtuse marginal branch through
the 5F catheter, a Monorail system through a 6F guiding catheter failed as well.
The overall technical success rate was 96%. Cardiac complications occurred in 2%
of patients (3 patients with Q-wave myocardial infarction). Two other patients
(1.5%) with suboptimal PTCA results underwent bypass surgery. PTCA through small
diagnostic catheters is a valid alternative technique in selected patients. It is
safe and leads to high success rates. Advantages of this technique include 1)
less peripheral and coronary trauma; 2) enhanced patient comfort; 3) economical
advantages.
PMID- 10785748
TI - Unravelling of a Wiktor Stent by a High Pressure Non-Compliant Balloon N
Successful Nonsurgical Management.
PMID- 10785747
TI - Non-Surgical Repair of Abdominal Aortic Aneurysm.
AB - The conventional treatment of abdominal aortic aneurysm is surgical replacement
with a synthetic graft. Attempts have been made to treat these aneurysms using
stent mounted grafts with reasonable success, thus obviating the need for
surgery. However, certain problems like thromboembolism and the large profile are
yet to be overcome. We report a case of a 75-year-old man where an attempt to
repair a symptomatic abdominal aortic aneurysm was made using an endovascular
uncovered OwallO stent combined with endosaccular coil implantation.
PMID- 10785749
TI - Bailout Palmaz-Schatz Stenting for Iatrogenic Dissection of the Left Main
Coronary Artery.
PMID- 10785751
TI - Heart Institutes N Structures in Evolution.
PMID- 10785750
TI - The Evolution of Heart Institutes.
PMID- 10785752
TI - A Beta-Particle Emitting Radioisotope Stent for the Prevention of Restenosis.
PMID- 10785753
TI - Endovascular Irradiation in the Therapy of Intimal Hyperplasia.
PMID- 10785754
TI - The Need for Standardization Testing for Safety and Efficacy of Permanent Implant
Stents.
PMID- 10785755
TI - Gene Therapy for Restenosis.
PMID- 10785757
TI - Microsurgical Dilatation Concept: Animal Data.
PMID- 10785756
TI - Interventional Cardiology: How Will We Cope with the Next Century?
PMID- 10785759
TI - Multicentric Non-Randomized Experience with Cutting Balloon.
PMID- 10785758
TI - Cutting Balloon System Technology: The Engineering Perspective.
PMID- 10785760
TI - Angiographic and Clinical Outcome after Cutting Balloon Angioplasty.
AB - To evaluate the safety and efficacy of cutting balloon angioplasty, we reviewed
the early angiographic and clinical outcomes of 160 consecutive patients with 173
lesions undergoing this procedure. Angiographic core laboratory analysis was
available in 150 of these lesions. Eccentricity was the most common (49%)
unfavorable pre-procedural morphologic feature; other morphologic findings
included length 3 10 mm (28%), calcification (23%), angulation 3 45 degrees
(13%), irregularity (7%), ostial location (3%), and thrombus (1%). OStand-aloneO
cutting balloon angioplasty was performed in 106 (71%) lesions and an adjunct
balloon or new device was used in 44 (29%) lesions to treat a residual stenosis >
40% after cutting balloon angioplasty. The reference artery size was 2.80 +/-
0.42 mm. The minimal lumen diameter increased from 1.02 +/- 0.30 mm to 2.01 +/-
0.42 mm (p < 0.001) and the % diameter stenosis was reduced from 64 +/- 9% to 29
+/- 12% (p < 0.001). Angiographic success (< 50% diameter stenosis ) was obtained
in 145 (97%) lesions. The residual stenosis was higher in lesions treated with
stand-alone cutting balloon angioplasty than in those undergoing adjunct balloon
or new device angioplasty (31 +/- 10 versus 24 +/- 14; p = 0.0006). The average
cutting balloon:artery ratios in those lesions with and without dissections after
cutting balloon use (1.00 +/- 0.11 versus 0.97 +/- 0.13, respectively; p = 0.29).
A significant inverse relationship between the cutting balloon:artery ratio and
the final % diameter stenosis was noted (R = 0.33; p = 0.0003). There were no
major in-hospital complications after cutting balloon use. This series
demonstrates the safety and efficacy of cutting balloon angioplasty as an
alternative to conventional balloon angioplasty in patients with non complex
coronary artery disease. A multicenter, randomized comparison of cutting balloon
angioplasty with conventional balloon angioplasty for prevention of restenosis is
currently underway.
PMID- 10785761
TI - Cutting Balloon Angioplasty: A Japanese CenterOs Early Experience.
PMID- 10785762
TI - Cutting Balloon Catheter: Clinical Considerations and Challenges.
PMID- 10785763
TI - Mechanism and Role of Platelets in Ischemic Events: Action of Therapeutic Agents.
PMID- 10785764
TI - Platelet Integrin Glycoprotein IIb/IIIa Inhibitors: Opportunities and Challenges.
PMID- 10785765
TI - Heparin and Control of Bleeding Complications During Platelet Glycoprotein
IIb/IIIa Receptor Antagonist Therapy During Percutaneous Coronary
Revascularization.
PMID- 10785766
TI - Clinical Benefit within Patient Subgroups Receiving c7E3 Fab (Abciximab) During
Percutaneous Coronary Revascularization: Subgroup Analysis from the EPIC Trial.
PMID- 10785767
TI - The Economics of IIb/IIIa Therapy.
PMID- 10785768
TI - Antithrombotic Therapy after Stent Deployment.
PMID- 10785769
TI - Use of ReoPro in a Complex Case.
PMID- 10785770
TI - A Case of Stent Mania and Maximizing Costs? For What:Whom Should We Pay?
PMID- 10785771
TI - Cost-EffectiveUtilization of Abciximab During Coronary Angioplasty in the Setting
of Unstable Angina: A Case Study.
PMID- 10785772
TI - ReoPro Clinical Development: Future Directions and Therapeutic Approaches.
PMID- 10785773
TI - Frequency and Prognostic Importance of Creatine Phosphokinase Myocardial Isoforms
after Successful Balloon and New Device Coronary Angioplasty.
AB - The frequency and prognostic importance of subclinical myocardial necrosis after
new device coronary intervention is not known. To identify the frequency of CPK
MB release after balloon and single new device angioplasty in native coronary
arteries, we reviewed the course of 810 patients who underwent successful single
lesion, native vessel angioplasty using balloon angioplasty (N=174), Gianturco
Roubin stent placement for suboptimal angioplasty results (N=31), Palmaz-Schatz
stent deployment (N=320), directional coronary atherectomy (N=102), or rotational
atherectomy (N=183). All patients had serial measurements of CPK-MB isoenzymes 6
and 18D24 hours after coronary intervention; absolute CPK-MB levels were
determined by radioimmunoassay (normal assay < 4 ng/ml). CPK-MB isoenzymes were >
2 times normal (> 8 ng/dl) in 15.6% of procedures, > 3 times normal (3 12 ng/ml)
in 11.5% of procedures, > 4 times normal (3 16 ng/ml) in 8.6% of procedures, and
> 5 times normal (3 20 ng/ml) in 7.7% of procedures. CPK-MB elevation > 2 times
normal was more common in those undergoing directional atherectomy (20.8%) and
Gianturco-Roubin stent placement (34,4%) than in those undergoing balloon
angioplasty (11.7%). No significant differences were noted in patients undergoing
rotational atherectomy (13.2%) or Palmaz-Schatz stent placement (15.6%) than in
those undergoing balloon angioplasty. CPK-MB > 5 times normal occurred after 7.7%
of procedures, but did not vary significantly among the devices used in this
study. We conclude that CPK-MB elevations > 2 times normal are highest in
patients undergoing directional coronary atherectomy and ObailoutO use of the
Gianturco-Roubin stent. No significant differences in CPK-MB elevation were seen
in patients undergoing balloon angioplasty, Palmaz-Schatz stent deployment, or
rotational atherectomy. Identification of the prognostic importance of these CPK
MB elevations is currently under study.
PMID- 10785774
TI - Theoretical and Clinical Aspects of Slow Flow and No-Reflow Phenomenon.
PMID- 10785775
TI - Extraction Atherectomy vs. PTCA in Treating Saphenous Vein Graft Disease: Focus
on Embolization.
PMID- 10785776
TI - Reduction of Post-Procedural Cardiac Enzyme Release Following Coronary
Interventions.
PMID- 10785777
TI - Mechanical Alternatives to Thrombolytics and PTCA in Acute Ischemic Syndrome.
PMID- 10785778
TI - Transradial Artery Coronary Angioplasty and Stenting: History and Single Center
Experience.
PMID- 10785779
TI - Transradial Approach for Coronary Angiography.
PMID- 10785780
TI - Percutaneous Transradial Approach for Coronary Revascularization: What Have We
Learned?
PMID- 10785781
TI - Right Transradial Approach for Coronary Procedures: Preliminary Results.
PMID- 10785783
TI - Hemostasis after Radial Artery Cardiac Catheterization.
PMID- 10785782
TI - Operator Radiation Exposure in PTCA: Comparison of Radial and Femoral Approaches.
AB - In order to evaluate the radiation risk associated with PTCA from the right
radial approach, operator radiation exposure was prospectively measured in 138
patients (pts) undergoing PTCA from the radial artery approach and in 126
patients from the femoral artery approach. Standard overhead and side table lead
curtain shields were used in the femoral group and radial group I (66 pts). In
radial group II (72 pts), a movable floor shield was added to the procedure for
additional radiation protection. The external whole body dose was measured
monthly using film dosimeters. Dose per case and dose per minute of fluoroscopy
time were calculated. Operator external whole body dose was significantly higher
when PTCA is performed from the radial artery (13.5 +/- 2.1 mrem/case) as
compared to the femoral artery (8.8 +/- 1.3 mrem/case) approach (p <.01). This
increased radiation exposure was reduced to less than the femoral artery when the
movable floor shield is added to standard x-ray protection (3.3 +/- 2.3
mrem/case, p <.01 vs. femoral). Thus, PTCA can be performed from the radial
artery approach without increased operator radiation exposure.
PMID- 10785784
TI - Clinical Evaluation of Current Stent Deployment Strategies.
AB - BACKGROUND: Coronary stenting has been demonstrated to reduce the incidence of
abrupt closure and restenosis. However, intensive anticoagulation regimens have
increased the number of vascular complications and hospital length of stay.
Consequently, the potential long-term cost effectiveness of stenting has been
jeopardized by a significant increase in procedural and hospital costs. These
drawbacks have resulted in evaluation of reduced anticoagulation programs and
alternative access sites. METHODS: Access-site and anticoagulation strategies
were analyzed in 377 patients who had undergone coronary stenting. Four groups
were compared: 114 patients stented from the femoral artery and treated with
warfarin, 87 patients stented from the radial artery and treated with warfarin,
88 patients stented from the femoral artery and treated with ticlopidine and
aspirin anticoagulation, and 88 patients stented from the radial artery and
treated with ticlopidine and aspirin. RESULTS: Primary success was similar in all
groups. Subacute closure occurred only in the groups managed with warfarin.
Access-site complications occurred only in the groups with femoral access. Total
hospital and post-procedure length of stay and total hospital charge were
significantly less in the ticlopidine groups. The radial/ticlopidine group was
the most cost-effective. CONCLUSIONS: Ticlopidine/aspirin therapy following
coronary stenting from either the femoral or radial approach reduced hospital
length of stay and hospital charge without subacute closure. Access-site
complications were not reduced by femoral/ticlopidine strategy but were
eliminated by the radial approach with either anticoagulation regimen. The
radial/ticlopidine strategy eliminated access-site complications and
significantly reduced hospital length of stay and hospital charge as compared to
femoral/ticlopidine and was the most cost-effective strategy.
PMID- 10785785
TI - Outpatient Transradial Coronary Stenting: Implications for Cost-Effectiveness.
PMID- 10785786
TI - Right Radial Access for PTCA: A Prospective Study Demonstrates Reduced
Complications and Hospital Charges.
AB - OBJECTIVE: The purpose of the present study was to evaluate the hypothesis that
angioplasty from the radial artery approach is more cost effective than that from
the femoral artery approach. BACKGROUND: Previous studies have demonstrated that
angioplasty can safely and effectively be performed from the radial artery
approach with a virtual absence of access-site complications. METHODS: One
hundred fifty-two patients were prospectively randomized to have their
angioplasty performed from either the radial or femoral approach. Angioplasty
results as well as various cost factors were compared. RESULTS: Primary success,
number of stents deployed, emergency bypass surgery, PTCA time, fluoroscopy time,
amount of contrast media, and catheterization laboratory charge were not
significantly different in the two groups. Access-site complications (0 RRA vs. 4
RFA, p <.04), post-procedure length of stay (2.1 days +/- 0.1 RRA vs. 2.6 +/- 0.3
RFA, p <.04), total hospital length of stay (3.6 days +/- 0.2 RRA vs. 4.5 +/- 0.4
RFA, p <.03), and total hospital charge ($14,374 +/- 467 RRA vs. 15,796 +/- 702,
p <.05) were all significantly less in the radial group. CONCLUSION: PTCA can be
performed from RRA as effectively as RFA without clinically significant access
site complications. Both post-procedure and total hospital stay are reduced,
leading to a 9% reduction in total hospital charges.
PMID- 10785787
TI - Stents DonOt Require Systemic Anticoagulation.But the Technique (and Results)
Must be Optimal.
PMID- 10785788
TI - Preliminary Results of the MUST Trial.
PMID- 10785789
TI - Adjunctive Antithrombotic Therapy with Stents, Current Status and Future
Prospects.
PMID- 10785791
TI - Transradial Coronary Stenting: A Passing Fad or Widespread Use in the Future?
PMID- 10785790
TI - Preliminary Results of the Music Study.
PMID- 10785792
TI - A Progress Report from BENESTENT II: Heparin Coating, Restenosis and Cost
Effectiveness.
PMID- 10785793
TI - PTA and Stents in the Treatment of Extracranial Circulation.
PMID- 10785794
TI - Molecular beacons: a novel DNA probe for nucleic acid and protein studies.
AB - A new concept has been introduced for molecular beacon DNA molecules. Molecular
beacons are a new class of oligonucleotides that can report the presence of
specific nucleic acids in both homogeneous solutions and at the liquid-solid
interface. They emit an intense fluorescent signal only when hybridized to their
target DNA or RNA molecules. Biotinylated molecular beacons have been designed
and used for the development of ultrasensitive DNA sensors and for DNA molecular
interaction studies at a solid-liquid interface. Molecular beacons have also been
used to study protein-DNA interactions. They have provided a variety of exciting
opportunities in DNA/RNA/protein studies.
PMID- 10785795
TI - Polyhomologation: the living polymerization of ylides
AB - The polymerization of dimethylsufoxonium methylide to produce linear
polymethylene polymers is described. The reaction is catalyzed/initiated by
trialkylboranes and gives organoboron star polymers as the primary product. The
reaction is a living polymerization, providing control over molecular weight and
functionality at the polymer chain ends. A variety of novel polymethylene
architectures are available by this methodology.
PMID- 10785796
TI - In situ monitoring of solid-state polymerization reactions in sodium
chloroacetate and sodium bromoacetate by 23Na and 13C solid-state NMR
spectroscopy
AB - The thermally induced solidstate polymerization reactions in sodium chloroacetate
and sodium bromoacetate, leading to poly(hydroxyacetic acid) (polyglycolide) and
NaCl and NaBr, respectively, were studied by isothermal in situ solid-state NMR
spectroscopy at 120, 130 and 140 degrees C with a time resolution of the order of
5 to 25 min. The nuclei probed were 23Na and 13C, allowing the parent compounds
(sodium halogenoacetates) and both reaction products (polymer and alkali halide)
to be monitored. For sodium chloroacetate, there is no evidence for the
involvement of intermediate phases during the reaction whereas this cannot be
excluded for sodium bromoacetate. The crystal structure of sodium bromoacetate
was determined directly from powder diffraction data by the Monte Carlo method,
and was found to be isostructural with sodium chloroacetate. The topochemical
reaction mechanism proposed previously for sodium chloroacetate is thus also
applicable for the polymerization reaction in sodium bromoacetate. The
mechanistic and kinetic information obtained from our in situ solid-state NMR
investigations is compared and contrasted with information obtained from other in
situ probes of the polymerization reactions in these materials.
PMID- 10785797
TI - Stereoselectivity and chiral recognition in copper(I) olefin complexes with a
chiral diamine
AB - Trigonal copper(I) complexes of the chiral bidentate ligand (1S,2S)-N,N'-Bis
(mesitylmethyl)-1,2-diphenyl-1,2-ethanediamine ((S,S)-1) have been prepared with
hydrocarbon olefins, as well as with allylic alcohols and ethers. The
stereochemistry of the complexes has been investigated by 1H NMR spectroscopy and
by combined quantum mechanics and molecular mechanics (QM/MM) computational
methods. The coordinated chiral nitrogen atoms can display equal (R, R) or
opposite (R, S) configuration, the latter being disfavored if steric hindrance is
present above and below the coordination plane. Although the complexes exist as
rapidly equilibrated mixtures of stereoisomers, one of these is often dominant,
and prochiral olefins are coordinated with high enantioface selection. In
addition, the [(S,S)-1]-Cu+ fragment selectively recognizes the R enantiomer of
secondary allylic alcohols and ethers, as confirmed by the X-ray crystal
structure analysis of the adduct with (R)-1-buten-3-ol. The reasons for the
observed selectivities have been elucidated, and lead to some implications which
are consistent with the enantioselection observed in catalytic cyclopropanation
reactions promoted by copper complexes of the same ligand.
PMID- 10785798
TI - A new method for the deprotection of benzyl ethers or the selective protection of
alcohols
AB - A new selective method for the deprotection of benzyl ethers situated next to
alcohols in the alpha, beta, or gamma position is presented which uses either NIS
or DIB/I2 as a reagent. After initial formation of a hypoiodite intermediate, the
reaction is believed to follow a radical pathway to resemble the Hoffman-Loffler
Freytag reaction. The formation of the intermediate hypoiodite is suggested on
the basis of NMR studies. Depending on the substrate, the corresponding
benzylidene derivatives or diols are isolated.
PMID- 10785799
TI - Alkaloids from marine organisms, Part 5. Biomimetic total synthesis of lamellarin
L by coupling of two different arylpyruvic acid units.
AB - Reaction of the ethyl 3-arylpyruvate 5a with the methyl 2-bromo-3-arylpyruvate 6b
in the presence of the 2-arylethylamine 4 afforded the pyrrole derivative 10,
which could be transformed into lamellarin L (1) in five steps. The synthesis
proceeds with 38% overall yield and mimics the probable biosynthesis of these
marine alkaloids.
PMID- 10785800
TI - Synthesis and trapping of transient 1,2-diselones to yield 1,4-diselenin
derivatives: calculated structures of 1,2-diselones, 1,2-diselenetes and their
sulfur analogues
AB - Two conceptually different routes to transient 1,2-diselones are reported: 1) via
ring fragmentation of the 1,4,2-diselenazine system 6, and 2) by the
tributylphosphane-induced depolymerisation of the shelf-stable organoselenium
polymer 15. Evidence for the intermediacy of 1,2-diselone species 7 and 16 is
provided in both cases by in situ trapping with dimethyl acetylenedicarboxylate
(DMAD) to yield 1,4-diselenin derivatives. The route via 15 is especially
expedient and trapping of 16 is efficient. Subsequent reactions of adduct 17
afford [1,2-ethanediylbis(diphenylphosphane)] [5,6-bis(methoxycarbonyl)-1,4
diselenin-2,3-dithiolato]nickel(IV) (20). Theoretical calculations at Hartree
Fock (HF) and Moller-Plesset electron-correlated levels (MP2) suggest that the
cyclic 1,2-diselenete structure 7c is significantly more stable than the acyclic
1,2-diselone structure 7a. For the bicyclic system 16, the difference in energy
between the cyclic and acyclic structures is considerably reduced due to the
conformational rigidity imposed by the fused 1,3-dithiole ring. In contrast, the
acyclic structures of the 1,2-dithione analogues 13a and 25a are computed to be
more stable than their corresponding cyclic 1,2-dithiete structures 13c and 25c.
PMID- 10785801
TI - A combined electrochemical quartz-crystal microbalance probe beam deflection
(EQCM-PBD) study of solvent and ion transfers at a poly
AB - The oxidative polymerisation of the complex2,3-dimethyl-N,N'-bis
(salicylidene)butane-2,3-diaminatonick-el(II), [Ni(saltMe)], was monitored by the
electrochemical quartz microbalance (EQCM) and crystal impedance techniques.
Polymerisation efficiency was maintained throughout deposition of a film, which
behaved rigidly, on the electrode. A combined EQCM-PBD (probe beam deflection)
study of the redox process of the film exposed to a monomer-free solution of 0.1
M tetraethylammonium perchlorate (TEAP) in acetonitrile showed an
electroneutrality mechanism dominated by anion movement accompanied by co
transfer of solvent above 0.8 V. The individual contributions of all the mobile
species involved in the redox switching of the poly[Ni(saltMe)] film were
determined quantitatively by temporal convolution analysis; the estimated
solution-phase diffusion coefficient of the exchanged species was 1.24 x 10(-5)
cm2s-1.
PMID- 10785802
TI - Hybrid open-framework iron phosphate--oxalates demonstrating a dual role of the
oxalate unit
AB - New inorganic-organic hybrid open-framework materials of the phosphate-oxalate
family, [Fe2(H2O)2-(HPO4)2(C2O4)].H2O (I), [Fe2(H2O)2-(HPO4)2(C2O4)].2H2O (II),
[C3N2H12]-[Fe2(HPO4)2(C2O4)1.5]2 (III), and [C3N2OH12][Fe2(HPO4)2(C2O4)1.5]2 (IV)
have been synthesized hydrothermally in the presence of structure-directing
amines. The amine molecules are incorporated in III and IV, whereas I and II are
devoid of them. The oxalate units act as a bridge between the layers in all the
compounds. The layers in I and II are entirely inorganic, being formed by FeO6
and PO4 units, whereas in III and IV oxalate units constitute the inorganic
layers and act as the bridge between these layers. Such a dual role of the
oxalate unit is unique and noteworthy. The formation of two types of inorganic
layers in I and II consisting of four-, six-, and eight-membered rings, indicates
the interconversions between the various rings in the phosphate--oxalates to be
facile. All the phosphate--oxalates show antiferromagnetic ordering at low
temperatures.
PMID- 10785803
TI - Host-guest interactions at self-assembled monolayers of cyclodextrins on gold
AB - We have developed synthesis routes for the introduction of short and long
dialkylsulfides onto the primary side of alpha-, beta-, and gamma-cyclodextrins.
Monolayers of these cyclodextrin adsorbates were characterized by
electrochemistry, wettability studies, X-ray photoelectron spectroscopy (XPS),
time-of-flight secondary ion mass spectrometry (TOF-SIMS), and atomic force
microscopy (AFM). The differences in thickness and polarity of the outerface of
the monolayers were measured by electro-chemistry and wettability studies. On
average about 70% of the sulfide moieties were used for binding to the gold, as
measured by XPS. Tof-SIMS measurements showed that the cyclodextrin adsorbates
adsorb without any bond breakage. AFM measurements revealed for beta-cyclodextrin
monolayers a quasi-hexagonal lattice with a lattice constant of 20.6 A, which
matches the geometrical size of the adsorbate. The alpha-cyclodextrin and gamma
cyclodextrin monolayers are less ordered. Interactions of the anionic guests 1
anilinonaphthalene-8-sulfonic acid (1,8-ANS) and 2-(p-toluidinyl)naphthalene-6
sulfonic acid (2,6-TNS) and the highly ordered monolayers of heptapodant beta
cyclodextrin adsorbates were studied by surface plasmon resonance (SPR) and
electrochemical impedance spectroscopy. The SPR measurements clearly showed
interactions between a beta-cyclodextrin monolayer and 1,8-ANS. Electrochemical
impedance spectroscopy measurements gave high responses even at low guest
concentrations (< or = 5 microM). The association constant for the binding of 1,8
ANS (K = 289,000 +/- 13,000M-1) is considerably higher than the corresponding
value in solution. (Partial) methylation of the secondary side of the beta
cyclodextrin strongly decreases the binding.
PMID- 10785804
TI - Merging organometallic chemistry with polyoxometalate chemistry
AB - A series of polyoxomolybdate-incorporated organometallic complexes has been
obtained by reaction of [MBr(CO)5] or solvated M(CO)3+ ions (M = Mn or Br) with
(nBu4N)2[Mo2O7] in methanol, sometimes in the presence of triols of the type
RC(CH2OH)3 (R = Me or CH2OH). Their molecular structures are related to those of
previously described polyoxoalkoxomolybdates through the formal replacement of
fac-MoO2(OR)+ units by topologically equivalent fac-M(CO)3+ units. Representative
pairs of structurally related clusters include [Mo2O6(OMe)4-Re(CO)32]2- and
[Mo4O10(OMe)6]2-, [Mo2O4MeC(CH2O)32Mn(CO)3]- and [Mo3O6(OMe)MeC(CH2O)32]-,
[Mo2O4HOCH2C(CH2O)32Mn(CO)32] and [Mo4O8(OEt)2MeC(CH2O)32],
[Mo6O16(OMe)2MeC(CH2O)32-Mn(CO)32]2- and [Mo8O20(OMe)4-MeC(CH2O)32]2-. Although
the frameworks of the majority of derivatives are based on tetranuclear units
which display the common rhomb-like structure, the alternative cubane-type
arrangement is observed in [Mo2O5(OMe)5M(CO)32]-.
PMID- 10785806
TI - pi conjugation across the tetrathiafulvalene core: synthesis of extended
tetrathiafulvalene derivatives and theoretical analysis of their unusual
electrochemical properties
AB - A series of extended tetrathiafulvalene (TTF) derivatives bearing one or two 1,4
dithiafulven-6-yl substitutents has been prepared. The new compounds present
remarkable electrochemical singularities compared with other TTF derivatives,
which are strongly affected by the nature of the substitution on the lateral
heterocycle(s). This unusual electrochemical behaviour follows a square-scheme
sequence and is attributed to structural changes upon oxidation of the pi
donating molecules. Digital simulations of the electrochemical data have been
used to reach the values of the kinetic and thermodynamic constants involved in
the square scheme. Theoretical calculations establish an important contribution
of a highly delocalised resonant form involving a tetravalent sulphur in oxidised
species, which could justify the occurrence of an electrochemical behaviour
distinct from that of TTF. Finally, third-order susceptibilities chi 3 of two of
these systems, for which electron-donating and electron-withdrawing substituents
coexist and are conjugated through the TTF pi system, are given.
PMID- 10785805
TI - Catalysis of the addition of benzenethiol to 2-cyclohexen-1-ones by uranyl
salophen complexes: a catalytic metallocleft with high substrate specificity.
AB - The base induced addition of benzenethiol to 2-cyclohexen-1-one and its 4,4-, 5,5
and 6,6-dimethyl derivatives is catalysed by a salophen-uranyl based
metallocleft 2 in chloroform solution with high turnover efficiency and low
product inhibition. Analysis of rate data coupled with equilibrium measurements
for complexation of the catalyst with the enone reactants and addition products
shows that the catalytic mechanism involves the three main steps typical of
single-substrate enzymatic processes, namely substrate binding and recognition,
transformation of the bound substrate, and release of the reaction product.
Unlike the reference salophen-uranyl 1, catalyst 2 is endowed with a structured
binding site responsible for a high degree of substrate specificity among the
investigated enones, due to recognition of their shape and size.
PMID- 10785807
TI - A highly enantiopure biconcave porphyrin with effective D4-structure
AB - A first representative of an effectively D4-symmetric biconcave porphyrin (1) was
prepared from a tetramerizing condensation of a C2-symmetric pyrrole (2). The
chiral pyrrole 2 was synthesized in a six-step reaction sequence starting from
the C2h-symmetric 2,6-di-tert-butylanthracene. The relevant stereochemistry was
introduced in a highly diastereo-discriminating Diels-Alder reaction with fumaric
acid di(-)menthyl ester, catalyzed by aluminum chloride. X-ray analyses of two of
the dimenthyl esters prepared unambiguously secured their tentatively assigned
absolute configuration and that of the pyrrole 2 (as the S,S isomer). The
enantiomeric purity of the pyrrole 2 was determined as 99% ee, using the Co11
complex of the porphyrin 1 as a chiral shift reagent. The pyrrole 2 lent itself
to a stereochemically nearly uniform preparation of the chiral, biconcave
porphyrin 1. Applying Horeau's principle, 1 was calculated to be present in an
enantiomeric excess of about 10(9):1. The validity of the statistical
considerations relevant for this estimate were verified by examination of the
results from preparative tetramerization experiments in which the enantiomeric
purity of the pyrrole 2 was deliberately lowered.
PMID- 10785808
TI - Ethynylogization of a coarctate fragmentation
AB - Coarctate reactions form a separate class of elementary closed-shell processes in
addition to polar and pericyclic reactions. Hence, they also follow a different
homology principle. Whereas vinylogous polar and pericyclic reactions differ in
the length of the reacting system by a double bond, coarctate reactions can be
homologized (ethynylogized) by extending a known system by a triple bond. The
prediction, which is based on theoretical considerations, is confirmed
experimentally by the fragmentation of cyclopropylethynyl nitrene to cyano
acetylene and ethylene, a reaction that is "ethynyloguous" to the known
fragmentation of cyclopropyl nitrene to ethylene and HCN.
PMID- 10785809
TI - X-ray structure of a trimeric 5,5'-biaryl/erythro-beta-O-4-ether lignin model:
evidence for through-space weak interactions.
AB - The crystal structure of a trimeric lignin model 1 presenting the characteristic
pattern of biphenyl (5,5') and aryl-alkyl-ether (beta-O-4) linkages has been
determined. The crystal system is triclinic and the crystallographic unit cell
consists of two monomeric molecules. These results are compared with crystal data
from the literature of simple models of the 5,5' and beta-O-4 structure type. The
availability of a terminal aldehyde function on the model affords some
interesting intermolecular interactions by weak hydrogen bonding which controls
the conformation of the molecule and the aromatic ring orientation in particular;
an unexpected cisoid conformation of the biaryl unit is observed based on the
64.4 degrees value found for the torsion angle between the two 5,5' aromatic
rings.
PMID- 10785810
TI - A mass spectrometry study of XCO+, X=Si, Ge: is SiCO+ a main group carbonyl?
Comments on the bonding in ground state SiCO and the
AB - The cation [Si,C,O]+ has been generated by 1) the electron ionisation (EI) of
tetramethoxysilane and 2) chemical ionisation (CI) of a mixture of silane and
carbon monoxide. Collisional activation (CA) experiments performed for mass
selected [Si,C,O]+, generated by using both methods, indicate that the structure
is not inserted OSiC+; however, a definitive structural assignment as Si(+)-CO,
Si(+)-OC or some cyclic variant is impossible based on these results alone.
Neutralisation-reionisation (+NR+) experiments for EI-generated [Si,C,O]+ reveal
a small peak corresponding to SiC+, but no detectable SiO+ signal, and thus
establishes the existence of the Si(+)-CO isomer. CCSD(T)@B3LYP calculations
employing a triple-zeta basis set have been used to explore the doublet and
quartet potential-energy surfaces of the cation, as well as some important
neutral states. The results suggest that both Si(+)-CO and Si(+)-OC isomers are
feasible; however, the global minimum is 2 pi SiCO+. Isomeric 2 pi SiOC+ is 12.1
kcal mol-1 less stable than 2 pi SiCO+, and all quartet isomers are much higher
in energy. The corresponding neutrals Si-CO and Si-OC are also feasible, but the
lowest energy Si-OC isomer (3A") is bound by only 1.5 kcal mol-1. We attribute
most, if not all, of the recovery signal in the +NR+ experiment to SiCO+ survivor
ions. The nature of the bonding in the lowest energy isomers of Si(+)-(CO,OC) is
interpreted with the aid of natural bond order analyses, and the ground state
bonding of SiCO+ is discussed in relation to classical analogues such as metal
carbonyls and ketenes.
PMID- 10785812
TI - Pnictides as symmetrically bridging ligands in novel neutral complexes
AB - The reaction of [LWCl] (3) [L = N(CH2CH2NiPr)3] with LiE(SiMe3)2 (E = P, As, Sb)
yields the novel, neutral pnictido-bridged complexes [LW = E = WL] (5-7). By
following the reaction, which starts from the LiP-(SiMe3)2 derivative, by 31P NMR
spectroscopy, the formation of an intermediate with a terminal pnictido ligand
can be ruled out. The paramagnetic complexes 5-7 are comprehensively
spectroscopically characterised. The X-ray structure analysis of the
heterocumulenes 5-7 reveals a linear structure in which the two W-"tren" units
bind to the central pnictido atom in a staggered conformation ["tren" = tren
based ligand; tren = tris(2-aminoethyl)-amine. When N2 is used as the inert gas
in the synthesis of the starting material [N(CH2CH2NNp)3WCl] [Np = CH2C-(CH3)3],
the complex [[N(CH2CH2NNp)3]W2(mu, eta 1: eta 1-N2)] (4) is formed as a side
product. Complex 4 possesses a hydrazido(4-) (N2(4-)) ligand connected by two
tungsten-"tren" moieties.
PMID- 10785811
TI - Chemoenzymatic synthesis of sialyl-trimeric-Lewis x.
AB - The decasaccharide sialyl-trimeric-Lewis x is a component of glycoproteins and
glycolipids that serve as E- and P-selectin ligands. The synthesis of this target
structure was accomplished by utilizing a combination of chemical and enzymatic
methods. Highlights of the chemical synthesis include minimal use of protecting
groups and regioselective glycosylations to arrive at a linear tri-lactosamine
structure. Glycosyltransferase-catalyzed reactions were then employed for the
addition of the terminal sialic acid and branch-point fucose residues. Notably,
fucosyltransferases V and VI showed different specificities for the sialyl-tri
lactosamine core structure.
PMID- 10785813
TI - Heat-shrinking spherical and columnar supramolecular dendrimers: their
interconversion and dependence of their shape on molecular taper angle
AB - Synthesis and modes of self-assembly are described for the tapered monodendritic
molecules 3,4,5-nGi-X of generation i = 1, 2, 3 (see structures below) that
contain multiple (CH2)nH alkyl chains on their periphery (n = 12, 14, 16) and a
polar group X at the apex (X = COOH, COONa, COOCs, CO(OCH2CH2)3OH). These
monodendrons self-assemble into supramolecular cylindrical or spherical
dendrimers, which in turn self-organise into p6mm columnar or Pm3n cubic
thermotropic liquid crystals, respectively. The two principal ways of affecting
the self-assembly of these compounds by means of their molecular architecture
are: a) by changing the width of the wide (aliphatic) end, and b) by changing the
volume at the apex. In the present work a) is controlled through temperature
(conformational disorder) and b) is controlled by chaging the generation number i
or the size of X, for example, through the choice of metal cation. The single
most important geometric parameter of these dendritic building blocks is the
molecular solid angle (taper angle) alpha; a high alpha leads to spherical and a
low alpha to cylindrical supramolecular dendrimers. Furthermore, alpha also
determines the equilibrium size of the supramolecular objects; a larger alpha
results in a smaller diameter. The unusually strong negative thermal expansion
coefficient of the cubic and columnar lattice is attributed to the excess of the
increasingly highly tapered molecules being rejected from their parent aggregates
and reassembling as new ones. Increasing alpha is also considered to be
responsible for the observed thermotropic columnar-cubic transition.
PMID- 10785814
TI - Catalytic concepts for the enantioselective synthesis of alpha-amino and alpha
hydroxy phosphonates.
AB - The enantioselective synthesis of alpha-amino- and alpha-hydroxy phosphonates by
catalytic processes has attracted considerable interest in the last few years,
not least because of the pharmaceutical interest in such compounds. This article
contains a compilation of the asymmetric synthesis methods developed to date. The
described synthetic routes are based on different catalytic concepts, namely,
hydrogenation, reductions, dihydroxylation, aminohydroxylation, and
hydrophosphonylation.
PMID- 10785815
TI - Asymmetric synthesis of 2-methyl cyclohexane carboxylic acids by heterogeneous
catalysis: mechanistic aspects
AB - The catalytic hydrogenation of (S)-alkyl-N-(2-methylbenzoyl)pyroglutamates was
studied over supported rhodium and ruthenium catalysts at room temperature and a
pressure of 5 MPa. The reaction was diastereoselective with the predominant
formation of (1S,2R)-2-methylcyclohexane carboxylic acid with a diastereomeric
excess (de) of up to 96%. The most stable conformation was determined by means of
a combination of modelling calculations, NMR spectroscopy and X-ray structural
determination. In this conformation, the carbonyl group of the pyroglutamate
auxiliary shields one face of the aromatic ring. The observed selectivity may
thus be explained by a preferential adsorption at the unshielded face which
avoids steric repulsion by the C=O group to result in a cis hydrogenation. The
addition of an amine, the nature of the support (alumina or active carbon) or of
the metal (Rh or Ru) were shown to give additional stabilisation of the
adsorption at the unshielded face to increase the diastereoisomeric excess.
PMID- 10785816
TI - The photochemistry of 1,3-butadiene rationalized by means of theoretical
resonance structures and their weights
AB - A complete active-space self-consistent-field wave function for the pi-electron
part of s-trans-1,3-butadiene has been expanded into a set of localized bonding
schemes and their weights. These bonding schemes are close to the resonance
structures used in organic chemistry. The expansion technique has been applied to
both the electronic ground state and the electronically first-excited singlet and
triplet pi,pi* states. The manifolds of large-weight bonding schemes represent
approximate resonance hybrids for the ground and the singlet and triplet pi,pi*
states of s-trans-1,3-butadiene. These resonance hybrids, obtained by theory
alone, permit a qualitative rationalization of a significant part of the known
singlet and triplet photochemistry.
PMID- 10785817
TI - Structure-based design, synthesis, and in vitro evaluation of bisubstrate
inhibitors for catechol O-methyltransferase (COMT).
AB - The enzyme catechol O-methyltransferase (COMT) catalyzes the Me group transfer
from the cofactor S-adenosylmethionine (SAM) to the hydroxy group of catechol
substrates. Potential bisubstrate inhibitors of COMT were developed by structure
based design and synthesized. The compounds were tested for in vitro inhibitory
activity against COMT obtained from rat liver, and the inhibition kinetics were
examined with regard to the binding sites of cofactor and substrate. One of the
designed molecules was found to be a bisubstrate inhibitor of COMT with an IC50 =
2 microM. It exhibits competitive kinetics for the SAM and noncompetitive
kinetics for the catechol binding site. Useful structure-activity relationships
were established which provide important guidelines for the design of future
generations of bisubstrate inhibitors of COMT.
PMID- 10785818
TI - Screw-sense-selective polymerization of aryl isocyanides initiated by a Pd-Pt mu
ethynediyl dinuclear complex: a novel method for the synthesis of single-handed
helical poly(isocyanide)s with the block copolymerization technique
AB - Living polymerization of chiral aryl isocyanides, such as m- and p
menthoxycarbonylphenyl isocyanides 2 and 5, initiated by the Pd-Pt mu-ethynediyl
dinuclear complex 1, proceeds with a high screw-sense selectivity to give the
poly(isocyanide)s 3 and 6, which exhibit a large specific rotation and an intense
CD band at lambda = 364 nm as a consequence of a helical chirality. The molar
optical rotation and molar circular dichroism of the resulting polymers 3 and 6
reach a constant value at a degree of polymerization (Pn) of more than 30. Screw
sense-selective polymerization of achiral aryl isocyanides that bear very bulky
substituents, such as 3,5-di(propoxycarbonyl)phenyl isocyanide (11), 3,5
di(butoxycarbonyl)phenyl isocyanide (13), and 3,5-di(cyclohexyloxycarbonyl)phenyl
isocyanide (15), is achieved by the use of chiral oligomer complexes 3(30) and
6(30), prepared from the reaction of 1 with 30 equivalents of 2 or 5, as an
initiator to give predominantly single-handed helical polymers. In contrast,
smaller aryl isocyanides are also polymerized by 3(30) and 6(30) with screw-sense
selectivity in the initial stage of the reaction, but the single-handed helix is
not preserved up to high molecular weight. Kinetic studies of the polymerization
of (L)- and (D)-2, or (L)- and (D)-5 with chiral oligomer complexes (L)-3(50) or
(L)-6(100) suggests that the screw sense of the polymer backbone is not
controlled kinetically, but rather that the thermodynamically stable screw sense
is produced.
PMID- 10785819
TI - Strontium selenogermanate(III) and barium selenogermanate(II,IV): synthesis,
crystal structures, and chemical bonding
AB - The new selenogermanates Sr2Ge2Se5 and Ba2Ge2Se5 were synthesized by heating
stoichiometric mixtures of binary selenides and the corresponding elements to 750
degrees C. The crystal structures were determined by single-crystal X-ray
methods. Both compounds adopt previously unknown structure types. Sr2Ge2Se5
(P2(1)/n, a = 8.445(2) A, b = 12.302 A, c = 9.179 A, beta = 93.75(3) degrees, Z =
4) contains [Ge4Se10]8- ions with homonuclear Ge-Ge bonds (dGe-Ge = 2.432 A),
which may be described as two ethane-like Se3Ge-GeSeSe2/2 fragments sharing two
selenium atoms. Ba2Ge2Se5 (Pnma, a = 12.594(3) A, b = 9.174(2) A, c = 9.160(2) A,
Z = 4) contains [Ge2Se5]4- anions built up by two edge-sharing GeSe4 tetrahedra,
in which one terminal Se atom is replaced by a lone pair from the divalent
germanium atom. The alkaline earth cations are arranged between the complex
anions, each coordinated by eight or nine selenium atoms. Ba2Ge2Se5 is a mixed
valence compound with GeII and GeIV coexisting within the same anion. Sr2Ge2Se5
contains exclusively GeIII. These compounds possess electronic formulations that
correspond to (Sr2+)2(Ge3+)2(Se2-)5 and (Ba2+)2- Ge2+Ge4+(Se2-)5. Calculations of
the electron localization function (ELF) reveal clearly both the lone pair on
GeII in Ba2Ge2Se5 and the covalent Ge-Ge bond in Sr2Ge2Se5. Analysis of the ELF
topologies shows that the GeIII-Se and GeIV-Se covalent bonds are almost
identical, whereas the GeII-Se interactions are weaker and more ionic in
character.
PMID- 10785820
TI - Highly organized spherical hosts that bind organic guests in aqueous solution
with micromolar affinity: microcalorimetry studies
AB - Two novel closed-shell hemicarcerand-like hosts with spherical cavities of 11 A
diameter that are soluble in aqueous solution were constructed. The binding of
xylenes, aryl ethers, polyaromatic compounds, ferrocene derivatives, and bicyclic
aliphatic compounds were examined by NMR spectroscopy and microcalorimetry. NMR
binding studies indicated that binding depended upon guest hydrophobicity and
shape. No binding was detected for guests in which a charge must be desolvated as
part of inclusion or for guests that can not fit within the cavity of the host.
Three complexes 2.naphthalene, 2.p-xylene, and 2.ferrocene were isolated and
found to be indefinitely stable in the solid phase and in aqueous solution. The
binding constants for these complexes are estimated to be greater than 10(8) M-1.
Thirteen guests were examined by microcalorimetry with binding constants ranging
between 10(7) and 10(3) M-1. A comparison of results obtained here with those
from previous work with beta-cyclodextrin and cyclophane hosts, along with
analysis of the entropy-enthalpy compensation data, indicate that there is a
higher degree of guest desolvation with this host structure than with open-shell
hosts. This accounts at least partially for the increase in affinity observed
with these closed-shell hosts. Replacing a hydroxy group in the host portal with
a hydrogen atom does not affect the binding constant, a finding consistent with
the guest residing deeply buried within the host cavity. It was observed that
aromatic guests are bound with higher affinity than aliphatic ones in agreement
with results that point to the importance of London dispersion forces in the
association of aromatic components in face-to-edge orientations. The correlation
of changes in NMR chemical shift with microcalorimetry data supports a model in
which increased CH-pi interactions strengthen association between host and guest
due to the dominant role of van der Waals dispersion forces. Remarkably, the
binding constant for the 1,4 isomer of dimethoxybenzene is 32 times higher than
for the 1,2 isomer, and even greater discrimination is observed between the
xylene guests since the binding constant for p-xylene is 80 times greater than
that for o-xylene. This discrimination between isomeric guests by a rigid host
indicates that changes in specific hydrophobic interactions have substantial
effects upon binding affinity.
PMID- 10785821
TI - Velcrands with snaps and their conformational control
AB - A novel class of self-folding velcrands was prepared that dimerize through
intermolecular forces. Solvophobic interactions on extended pi surfaces stabilize
the dimer similar to velcrands, while eight hydrogen bonds act like snaps to hold
the molecules together. The self-complementary array of hydrogen bonding sites
were incorporated on the upper rim of a resorcinarene-based cavitand. A dramatic
reorganization of shape and size of the internal cavity was manifested through
changes in solvent polarity. Specifically, the equilibrium between the extended
surface (D2d symmetry) and a deep cavity (C4v symmetry) could be manipulated in
mixtures of aromatic solvents (or CDCl3) and [D6]DMSO. The switching of
conformations and the dimerization motif are well-suited for the assembly of
noncovalent polymeric materials.
PMID- 10785822
TI - Nonaqueous ionic liquids: superior reaction media for the catalytic Heck
vinylation of chloroarenes
AB - Nonaqueous ionic liquids, that is molten salts, constitute an activating and
stabilizing noninnocent solvent for the palladium-catalyzed Heck-vinylation of
all types of aryl halides. Especially with chloroarenes an improved activity and
stability of almost any known catalyst system is observed as compared to
conventional, molecular solvents (e.g. dimethylformamide (DMF), dimethylacetamide
(DMAc), N-methyl-2-pyrrolidinone (NMP), or dioxane). Thus, even catalytic amounts
of ligand-free PdCl2 yield stilbene from technically interesting chlorobenzene
and styrene in high yield (turnover number (TON) = 18) without the need for
further promoting salt additives such as tetraphenylphosphonium chloride. The
scope of the new reaction medium is outlined for the first time for the
vinylation of various aryl halides using different mono- and disubstituted
olefins as well as a variety of known palladium(0) and palladium(II) catalyst
systems. Furthermore, a novel means of catalyst recycling is presented and its
scope is evaluated.
PMID- 10785823
TI - 2,2'-bipyridine lariat calixcrowns: a new class of encapsulating ligands forming
highly luminescent Eu3+ and Tb3+ complexes
AB - A new class of calix[4]arene crown ethers with one or two bipyridines appended to
the polyether ring (lariat calixcrowns) have been designed and synthesized; the
luminescence properties of their Eu3+ and Tb3+ complexes have been studied in
acetonitrile. In this solvent, long lifetimes for the metal emitting states and
high metal-luminescence intensities obtained upon ligand excitation have been
observed in both Eu3+ and Tb3+ complexes. The association constants in methanol
have been determined for some of the complexes studied.
PMID- 10785825
TI - Short-range interactions within molecular complexes formed in supersonic beams:
structural effects and chiral discrimination
AB - One- and two-color, mass-selected R2PI spectra of the S1<--S0 transitions in the
bare chiral chromophore R-(+)-1-phenyl-1-propanol (R) and its complexes with a
variety of alcoholic solvent molecules (solv), namely methanol, ethanol, 1
propanol, 2-propanol, 1-butanol, S-(+)-2-butanol, R-(-)-2-butanol, 1-pentanol, S
(+)-2-pentanol, R-(-)-2-pentanol, and 3-pentanol, were recorded after a
supersonic molecular beam expansion. Spectral analysis, coupled with theoretical
calculations, indicate that several hydrogen-bonded [R.solv] conformers are
present in the beam. The R2PI excitation spectra of [R.solv] are characterized by
significant shifts of their band origin relative to that of bare R. The extent
and direction of these spectral shifts depend on the structure and configuration
of solv and are attributed to different short-range interactions in the ground
and excited [R.solv] complexes. Measurement of the binding energies of [R.solv]
in their neutral and ionic states points to a subtle balance between attractive
(electrostatic and dispersive) and repulsive (steric) forces, which control the
spectral features of the complexes and allow enantiomeric discrimination of
chiral solv molecules.
PMID- 10785824
TI - Conformational differences between O- and C-glycosides: the alpha-O-man-(1-->1)
beta-Gal/alpha-C-Man-(1-->1)-beta-Gal case--a decisive demonstration of the
importance of the exo-anomeric effect on the conformation of glycosides.
AB - The conformational behavior of alpha-O-Man-(1-->1)-beta-Gal (1) and its C
analogue (2) has been studied using J/NOE NMR data, molecular mechanics,
molecular dynamics, and ab initio calculations. The population distribution
around the glycosidic linkages of 1 and 2 is rather different, especially for the
alpha-Man linkage. A lower limit for the exo-anomeric effect in water has been
experimentally determined.
PMID- 10785827
TI - Chiral "metallo-spiralenes": helical molecules conformationally stabilised by an
organometallic scaffold
AB - The synthesis of a series of chiral cyclomanganated 2-[(eta 6-phenyl)
Cr(CO)3]pyridine complexes derived from (-)-beta-pinene enables, by a "spirogenic
transformation", the preparation of four different chiral helical
heterobimetallic syn-facial complexes or Cr0/Mn1-spiralenes, among which two
possess a right-handed P molecular helicity and two other a left-handed M one.
These organometallic helical molecules are synthesised by applying two different
methods to the chiral cyclomanganated (eta 6-arene)tricarbonylchromium
substrates. The first method is the so-called "Fischer route" which involves a
sequential addition of PhLi and MeOTf. The second method based on reaction of the
cyclomanganated complex with diphenyldiazomethane which has been tested on
achiral bimetallic substrates is a reasonable neutral alternative to the "Fischer
methodology" for the synthesis of Cr0/Mn1-spiralenes. The crystal structure of
one of these heterobimetallic chiral helical compounds serves as a starting point
in the configurational and structural assessment of the synthesised chiral (eta 6
arene)tricarbonylchromium complexes. Application of the "Fischer route" to a
cyclomanganated chiral 2-phenylpyridine generates a single chiral eta 3-benzylic
complex--or Mn1-spiralene--bearing a left-handed M helicity which has been
characterized by X-ray diffraction analysis. Circular dichroic spectroscopic
measurements underline the predominant contribution of the chiral and chirally
induced aromatic chromophores to the sign of the Cotton effects and confirm the
helical configurations of the considered heterobimetallic species.
PMID- 10785828
TI - Electronic excitations in homopolyatomic bismuth cations: spectroscopic
measurements in molten salts and an ab initio CI-singles study
AB - The electronic excitations of the low-valence bismuth cluster cations Bi5(3+),
Bi8(2+), and Bi9(5+) have been studied with experimental and theoretical
techniques. The UV-visible spectra of the bismuth ions were measured in acidic
chloroaluminate melts (mixture of 1-methyl-3-benzyl imidazolium chloride and
AlCl3). The spectra of the Bi5(3+) and Bi8(2+) ions agree fairly well with
previous reports, but also revealed additional low-energy absorptions. Ab initio
methods were employed to assign the experimentally observed electronic
transitions of these homopolyatomic bismuth cations. Structures were optimized at
the RHF, MP2, and B3LYP levels of theory by using split-valence LANL2DZ basis
sets that were augmented with one and two sets of pure d functions. The computed
structures agree well with the results of neutron diffraction analyses of melts.
Electronically excited states of the three clusters were treated by using the CI
Singles theory. The results of these calculations were used to explain the
observed UV-visible spectra. The observed electronic excitations in the UV
visible range are all found to result from transitions involving the molecular
orbitals formed by 6p-atomic-orbital overlap. This leads to the necessity of
using basis sets that include d-type functions, which allow for an adequate
description of the bonding that results from such p-orbital overlap. Spin-orbit
coupling becomes increasingly important with increasing atomic number and its
consideration is necessary when describing the electronic transitions in clusters
of heavy atoms. The calculations show that singlet-triplet transitions, which are
made accessible by strong spin-orbit coupling, are responsible for some of the
observed absorptions.
PMID- 10785826
TI - Design and synthesis of an alpha,alpha-difluorophosphinate hapten for antibody
catalyzed hydrolysis of organophosphorus nerve agents.
AB - In a new approach to the safe neutralization of organophosphorus chemical
weapons, we designed a hapten to elicit catalytic antibodies with phosphatase
activity. Here we report the synthesis of this alpha,alpha-difluorophosphinate
hapten 6. Various methods for the introduction of the key alpha,alpha
difluoromethyl feature into the phosphinate hapten are discussed. The best
results were obtained with the electrophilic gem-difluorinating agent N
fluorobenzenesulfonimide.
PMID- 10785829
TI - Direct observation of single-molecule generation at a solid-liquid interface
AB - Direct observation of single-molecule generation from a chemical reaction was
achieved at a solid-liquid interface. The reaction between fluorescamine and
immobilized N'-(3-trimethoxysilylpropyl)diethylenetriamine (DETA) was studied at
the single-molecule level. Time-lapse fluorescence images of single-molecule
products, excited by the evanescent field generated at a quartz-liquid interface,
were recorded to follow the chemical reaction to its completion. The reactions
were restricted to the approximately 1 nm thick layer nearest to the interface.
Analysis of the photoelectron intensity of the fluorescent product of the
reaction and its distribution shows that the reaction kinetics goes through a
transition from zeroth-order to first-order as the reaction proceeds. This
approach offered a novel means to study single-molecule reactions at the solid
liquid interface. It also enabled the investigation of reaction kinetics and
chemical mapping of surface heterogeneity at the single-molecule level.
PMID- 10785830
TI - Pain in Parkinson's disease.
AB - Pain, defined as an unpleasant or distressing sensory experience, has been
recognized as feature of Parkinson's disease (PD) since the first descriptions of
the disorder. Pain is estimated to occur in approximately 40% of patients with
PD, and in a minority of individuals becomes severe enough to overshadow the
motor symptoms of the disorder. Recent studies based on patients' descriptions of
pain have enabled a classification of painful sensations into 1 or more of 5
categories: musculoskeletal pain, neuritic or radicular pain, dystonia-associated
pain, primary or central pain, and akathitic discomfort. The existence of a
central pain syndrome, intrinsic to PD, finds support in a collection of case
reports, but the precise mechanism is unknown, and a correlation with pathology
has not been made. This review describes the clinical features of the pain
syndromes in PD, and provides a framework for evaluating, classifying, and
treating painful symptoms in PD.
PMID- 10785831
TI - Sexual dysfunction in Parkinson's disease.
AB - Sexual dysfunction is seen in a number of neurologic diseases. In this article we
review normal human sexual response, some neurologic diseases in which sexual
dysfunction is seen, and Parkinson's disease (PD). With PD there is often a
reduction in sexual interest and function. The studies documenting these problems
are detailed. In addition, we focus on the syndrome of hyper- or aberrant sexual
function seen with pharmacotherapy of PD.
PMID- 10785832
TI - Urinary dysfunction in Parkinson's disease.
AB - Urinary symptoms are very common in Parkinson's disease (PD). They are primarily
irritative (frequency, urgency, urge incontinence) and correlate with the
urodynamic finding of involuntary detrusor contractions at early stages of
bladder filling (detrusor hyperreflexia). Obstructive symptoms (hesitancy, weak
urinary stream) may be seen in a smaller number of patients by themselves or
combined with irritative symptoms. They may be secondary to anticholinergics,
obstructive uropathy, or point to the presence of multiple system atrophy.
Dysfunction of the striated urethral sphincter and pelvic musculature can be seen
in variable numbers in PD, with the main abnormality that of delayed relaxation
at the time of initiation of voluntary voiding.
PMID- 10785833
TI - Behavioral dysfunction in Parkinson's disease.
AB - Behavioral manifestations of Parkinson's disease (PD) are often more debilitating
than the motor manifestations. These occur both as primary manifestations of the
disease and as drug-induced complications. While dementia and abulia are common
problems that are not currently treatable, depression and psychosis often respond
extremely well to medication. Phenomenology, pathology, and general approaches to
treatment will be discussed.
PMID- 10785834
TI - Olfactory dysfunction in Parkinson's disease.
AB - The olfactory system is one of the nonmotor systems severely affected in
Parkinson's disease (PD). Olfactory dysfunction occurs early in the disease
process, is independent of disease stage, duration, and treatment. However,
olfactory dysfunction appears to be dependent on disease subtype. Olfaction is
mildly impaired or preserved in most of the parkinsonism-plus syndromes (PPS).
This provides a means of differential diagnosis between typical PD and PPS.
Olfactory function is impaired also in familial forms of parkinsonism in which
the genetic defect is known. In familial parkinsonism, olfactory function is
impaired in both typical PD and PPS phenotypes. Olfactory dysfunction does not
appear to be a manifestation of dopamine deficiency. Olfactory dysfunction is
also associated with other neurodegenerative diseases such as Alzheimer's disease
(AD), Huntington's disease (HD), as well as with normal aging. The
neuropathological changes observed in the olfactory system in PD and other
neurodegenerative diseases appear to be disease-specific, raising the possibility
that olfactory dysfunction may be the result of a central rather than a
peripheral process. The cellular and molecular mechanisms underlying olfactory
dysfunction in PD and other neurodegenerative diseases remain unknown.
PMID- 10785835
TI - Visual dysfunction in Parkinson's disease.
AB - Several abnormalities of visual function have been demonstrated in Parkinson's
disease (PD) by both electrophysiologic and psychophysical testing. Prolonged
visual evoked potential latencies and abnormal electroretinographic patterns,
both of which respond to levodopa therapy, have been demonstrated in Parkinson's
disease patients and in primates with experimental parkinsonism suggesting that
retinal dopamine deficiency is an important factor in the pathogenesis of PD
visual dysfunction. Abnormalities of color perception, especially in the blue
green axis, and of visual contrast sensitivity (VCS) have also been well
documented in PD patients. Although VCS impairment is likely related to retinal
dopaminergic dysfunction, the fact that this visual abnormality is orientation
specific raises the possibility of visual cortex involvement as well. Visual
abnormalities in PD are usually clinically occult and not likely to be uncovered
during a routine neurological examination or by ordinary high contrast visual
acuity testing. The clinician must be aware, however, that several forms of
disability ranging from gait freezing to visual hallucinations may be linked to
an underlying impairment of visual function in Parkinson's disease.
PMID- 10785836
TI - Sleep dysfunction in Parkinson's disease.
AB - The frequency of sleep complaints in patients with Parkinson's disease (PD) is
estimated to be between 60-90% and a variety of either disease-related or
secondary mechanisms and the dopaminergic treatment itself contributes to the
development of different sleep disturbances. These comprise slight, fragmented
sleep with increased number of arousals and awakenings, and PD-specific motor
phenomena such as nocturnal immobility, rest tremor, eye-blinking, dyskinesias,
and other phenomena such as periodic and nonperiodic limb movements in sleep,
restless legs syndrome, fragmentary myoclonus, and respiratory dysfunction in
sleep. Depression and hallucinations/psychosis further complicate the picture.
The incidence of REM sleep behavior disorder (RBD) with nightmares and violent
behavior is increased in PD and may occur as a preclinical disease-related
symptom. A careful sleep history of patients and their partners, polysomnograms
when necessary, motor and psychiatric assessments should precede individual
treatment strategies, which include adjusting dopaminergic daytime treatment,
benzodiazepines for RBD, reduction of anticholinergic drugs, and, if necessary,
clozapine for nocturnal psychosis.
PMID- 10785837
TI - Imaging of nonmotor symptoms in Parkinson syndromes.
AB - Neuroimaging modalities in Parkinson's Disease (PD) are primarily used for the
differential diagnosis of Parkinson syndromes and to understand
pathophysiological mechanisms in PD. Neuroimaging of nonmotor dysfunctions in PD
mostly consist of functional studies in neuropsychologically impaired PD patients
using PET or SPECT techniques. Various studies controversially discuss the
probable frontal versus temporal hypometabolism in demented PD patients.
Functional studies of PD patients with depression are limited to case reports
showing an involvement of left frontal regions. To investigate the
pathophysiology of hallucinations with functional imaging may be a promising
field of future research.
PMID- 10785838
TI - Neurophysiology of sensorimotor integration in Parkinson's disease.
AB - Parkinson's disease (PD) is a major neurologic disorder that distinctively and
selectively affects movement and--by extension--the motor system. A large body of
evidence has been accumulated over the years showing that movement disorders of
PD are also due to sensory disturbances that affect sensorimotor integration. The
aim of this review is to discuss the possible contribution of neurophysiologic
techniques in evaluating the functionality of sensorimotor integration mechanisms
in PD. Somatosensory evoked potentials (SEPs) are an appropriate functional
approach for the evaluation of sensory processes in the human brain. SEPs from
the frontal scalp sites are considered markers of the functionality of a cortico
subcortico-cortical loop that includes the basal ganglia as well as the premotor
and supplementary motor areas. Over the years, it has been demonstrated that PD
patients--especially in the early stages of the disease--show a severely
depressed frontal responsiveness to sensory stimuli as tested via SEPs. The
transient recovery of frontal SEP amplitude after apomorphine, a potent dopamine
agonist drug, is a good and specific predictor of the clinical response of PD
patients to L-dopa therapy.
PMID- 10785839
TI - Respiratory function in Parkinson's disease.
AB - This article reviews the spectrum of respiratory dysfunction in Parkinson's
disease (PD). It includes the primary effects of PD on the ventilation, response
to medications, and pulmonary complications of antiparkinson therapy. Primary
pulmonary abnormalities include a restrictive change mainly secondary to chest
wall rigidity and upper airway obstruction; both are responsive to dopaminergic
modulation. Respiratory dyskinesia, a side effect of levodopa therapy, may
produce both restrictive and dyskinetic ventilation. Therapy with ergot
derivatives may result in pleuropulmonary fibrosis. Lastly, pulmonary infection
as a consequence of disordered respiratory mechanics continues to contribute
significantly to morbidity and mortality in PD.
PMID- 10785840
TI - Gastrointestinal dysfunction in Parkinson's disease.
AB - Gastrointestinal dysfunction is a frequent and occasionally dominating symptom of
Parkinson's disease (PD). Features of gastrointestinal dysfunction include
disordered control of saliva, dysphagia, gastroparesis, constipation in the sense
of decreased bowel movement frequency, and defecatory dysfunction necessitating
increased straining and resulting in incomplete evacuation. Excess saliva
accumulates in the mouth because of decreased swallowing frequency. Dysphagia
develops in approximately 50% of patients and may be a reflection of both central
nervous system and enteric nervous system derangement. Gastroparesis may produce
a variety of symptoms, including nausea, and also may be responsible for some of
the motor fluctuations seen with levodopa therapy. Bowel dysfunction in PD may be
the result of both delayed colon transit and impaired anorectal muscle
coordination.
PMID- 10785841
TI - Visuo-cognitive dysfunctions in Parkinson's disease.
AB - Loss of will, decreased activity, and poverty of behavior are among the common
symptoms observed in Parkinson's disease (PD). In line with these clinical
observations, PD patients display prominent deficit in neuropsychological tests,
requiring self-generated and effort-demanding operations. However, recent
evidence suggests that this impairment is not generalized: visuo-spatial working
memory and attentional set-shifting seem to be selectively impaired in the early
stages of the disease. Electrophysiological studies also demonstrate the
dysfunction of higher-level visual information processing. In this article, we
discuss some current results to show the connection between clinical symptoms and
neuropsychological deficits. We also consider dysfunction in underlying neural
mechanisms, with particular emphasis on the dysregulation of fronto-striatal
circuits. However, it is conceivable that visuo-cognitive impairment in PD
reflects dysfunction of neural assemblies, involving basal ganglia, dorsal visual
stream, and frontal-prefrontal circuits.
PMID- 10785842
TI - Cardiovascular autonomic dysfunction in parkinsonian patients.
AB - Cardiovascular dysfunction may occur in parkinsonian patients for a variety of
reasons. Patients usually are more than 50 years old and on various drugs (both
antiparkinsonian and for associated medical disorders), some of which may have
cardiovascular effects. Autonomic failure increases with age and also is
recognized in parkinsonian patients who have the disorder multiple system
atrophy, in which there is substantial cardiovascular dysfunction. Thus,
recognition of cardiovascular dysfunction and its causes in parkinsonian patients
is of importance in diagnosis (in separating the various parkinsonian diseases),
in determining prognosis, and finally in management. This article outlines the
major areas of cardiovascular dysfunction, including disorders of blood pressure
control, heart rate, and regional circulation, especially to vital organs.
Clinical features and evaluation are described, together with abnormalities in
different parkinsonian disorders and the principles of management.
PMID- 10785843
TI - The role of costimulatory molecules as targets for new immunosuppressives in
transplantation.
AB - T-cell costimulation is critical for all T-cell-mediated immune responses that
are responsible for endpoints such as allograft rejection or autoimmune disease.
Recent experimental data elucidate specific pathways for T-cell activation and
negative regulatory mechanisms via unique costimulatory molecules. These data
have implications for the development of novel therapeutic strategies to prevent
graft rejection and improve long-term graft survival in transplant patients, and
to treat autoimmune diseases in humans.
PMID- 10785844
TI - Vasoactive substances in renal transplantation.
AB - During and after transplantation the kidney experiences a variety of insults that
result in functional impairment and structural damage. These changes are mediated
or influenced by hormones, cytokines, enzymes and growth factors, which are
excreted by endothelial, graft parenchymal as well as by graft infiltrating
cells. This review evaluates the pathophysiological role of vasoactive substances
(for example, the vasoconstrictors angiotensin II and endothelin, as well as
vasodilators such as nitric oxide, adrenomedullin and atrial natriuretic peptide)
in kidney transplantation and summarizes recent reports that indicate that
targeting vasoactive substances may represent effective therapeutic strategies
for the achievement of long-term allograft survival.
PMID- 10785845
TI - The importance of genetic polymorphisms in renal transplantation.
AB - Genetic variations including single nucleotide polymorphisms, dinucleotide
repeats and microsatellites have been identified in a number of genes encoding
cytokines, cytokine receptors, chemokines and their receptors, adhesion
molecules. Several of the polymorphisms are located in the promoter region of the
gene, affect transcription or translation, and not infrequently determine the
level of expression of the protein product. An interesting and testable
hypothesis for the clinical heterogeneity and differential responsiveness in
allograft recipients is genetic variation. These nucleotide sequence variations,
polymorphisms located in genes contributing to immune repertory and in genes
responsible for drug metabolism, are excellent candidates for the differential
clinical phenotype.
PMID- 10785846
TI - Impact of dyslipidaemia in renal transplant recipients.
AB - The evidence that lipid disorders in patients following renal transplantation
play a major role in the pathogenesis of atherosclerosis and chronic renal
allograft rejection is circumstantial. The absolute rate of clinical vascular
disease and cardiovascular complications in transplant patients, the high
prevalence of an atherogenic lipid profile and the evidence from the large HMG
CoA reductase inhibitor (statin) regression trials in the general population
suggest that lipid lowering treatment is necessary in most patients after renal
transplantation. Furthermore, animal models and observational studies in patients
have found correlations between plasma lipid levels and both acute and chronic
rejection. Animal transplant models and clinical trials in heart transplant
patients also suggest that statin treatment decrease the incidence of chronic
rejection in a manner that may also be independent of lipid lowering. Although
the mechanisms behind this protective effect remains unclear, statins may be the
first agents to be effective in preventing chronic rejection and in reducing the
rate of cardiovascular complication in renal transplant recipients.
PMID- 10785847
TI - Mechanisms of hypertension after renal transplantation.
AB - Hypertension is extremely prevalent after renal transplantation, affecting up to
70% of all patients. An elevation in blood pressure is associated with an
increased cardiovascular risk and may also contribute to chronic allograft
failure. Renal transplantation provides interesting insights into the
pathogenesis of hypertension. Experimental and human data show that the kidney is
an essential organ for blood pressure regulation. In clinical practice a
differential diagnosis that is based on excretory allograft function has proved
useful.
PMID- 10785849
TI - The safe administration of intravenous contrast material for urologists and
radiologists.
PMID- 10785848
TI - Hyperhomocysteinemia in organ transplantation.
AB - An elevated total homocysteine plasma concentration is associated with an
increased morbidity and mortality due to cardiovascular disease in the general
population, in patients with renal failure and in recipients of kidney or heart
transplants. The fasting or post-methionine loading plasma concentration of total
homocysteine is elevated in 50-60% of renal transplant recipients with stable
graft function and in the majority of heart transplant recipients. Fasting and
post-methionine loading hyperhomocysteinemia can be normalized in virtually all
renal transplant patients by a combination of folic acid (5 mg/d), vitamin B6 (50
mg/d) and vitamin B12 (0.4 mg/d). In individuals without renal failure much lower
doses of folate and vitamin B12 are able to correct hyperhomocysteinemia.
Currently, prospective studies are under way to clarify whether folate and
vitamin therapy improves cardiovascular disease morbidity and mortality in the
general population and in organ transplant recipients. While population wide
screening for and treatment of hyperhomocysteinemia is generally not recommended,
treatment of high risk patients, including renal failure patients and kidney and
heart transplant recipients, can be considered but still represents an
experimental therapy.
PMID- 10785850
TI - Testicular microlithiasis.
AB - Testicular microlithiasis is an uncommon condition that is characterized by
calcifications within the lumina of seminiferous tubules. It is usually an
incidental finding on high frequency scrotal sonography. Testicular
microlithiasis is a benign condition but is associated with testicular
malignancies. Recent reports support this association and suggest regular follow
up in these patients.
PMID- 10785851
TI - Imaging guided biopsies of renal masses.
AB - Percutaneous fine-needle aspiration biopsy can be used for the diagnosis of many
abdominal masses. It is safe and accurate, and is often all that is necessary to
determine treatment. Fine-needle aspiration biopsy is both accurate and cost
effective, comparing favorably with open surgical biopsy. The use of percutaneous
biopsy for the diagnosis of renal masses is now more commonplace as urologists
and radiologists become familiar with its indications, contraindications,
accuracy and complications.
PMID- 10785852
TI - Risks and complications of transrectal ultrasound.
AB - Transrectal ultrasound guided needle biopsies of the prostate are routinely
performed to diagnose and stage prostate cancer. This diagnostic technique is a
safe method to diagnose prostate cancer with few major complications but frequent
minor complications.
PMID- 10785853
TI - Radiology of urinary diversions.
AB - Radiologic evaluation of urinary diversion has three objectives: to monitor upper
tract distention, to detect new urothelial tumors and to detect metastasis. The
type of imaging procedure and the frequency of imaging is dictated by the
urologist preference. As many surgical procedures are available for noncontinent
and continent diversion, interpretation of radiographic studies requires a
detailed knowledge of the type of surgical procedure that has been performed.
PMID- 10785854
TI - Unenhanced helical computed tomography in the evaluation of acute flank pain.
AB - Noncontrast helical computed tomography has rapidly replaced other imaging
modalities in the evaluation of patients with acute flank pain. New studies from
multiple centers have compared helical computed tomography directly with
intravenous urography in large numbers of patients, confirming the value of the
former. It is highly sensitive and specific for the diagnosis of
ureterolithiasis, including the visualization of ureteral calculi and secondary
signs of obstruction. It can evaluate alternate diagnoses, improving the utility
of noncontrast helical computed tomography as a diagnostic tool in the evaluation
of acute flank pain.
PMID- 10785855
TI - Bibliography. Current world literature. Renal medicine and renal transplantation.
PMID- 10785856
TI - Bibliography. Current world literature. Imaging--new diagnostic techniques.
PMID- 10785857
TI - Mx mRNA expression and RFLP analysis of rainbow trout Oncorhynchus mykiss genetic
crosses selected for susceptibility or resistance to IHNV.
AB - Three interferon-inducible Mx genes have been identified in rainbow trout
Oncorhynchus mykiss and their roles in virus resistance have yet to be
determined. In mice, expression of the Mx1 protein is associated with resistance
to influenza virus. We report a study to determine whether there was a
correlation between the expression of Mx in rainbow trout and resistance to a
fish rhabdovirus, infectious hematopoietic necrosis virus (IHNV). A comparison of
Mx mRNA expression was made between different families of cultured rainbow trout
selected for resistance or for susceptibility to IHNV. A trout-specific Mx cDNA
gene probe was used to determine whether there was a correlation between Mx mRNA
expression and resistance to the lethal effects of IHNV infection. Approximately
99% of trout injected with a highly virulent strain of the fish rhabdovirus,
IHNV, were able to express full length Mx mRNA at 48 h post infection. This is
markedly different from the expression of truncated, non-functional Mx mRNA found
in most laboratory strains of mice, and the ability of only 25% of wild mice to
express functional Mx protein. A restriction fragment length polymorphism (RFLP)
assay was developed to compare the Mx locus between individual fish and between
rainbow trout genetic crosses bred for IHNV resistance or susceptibility. The
assay was able to discriminate 7 distinct RFLP patterns in the rainbow trout
crosses. One cross was identified that showed a correlation between homozygosity
at the Mx locus and greater susceptibility to IHN-caused mortality.
PMID- 10785858
TI - Use of RT-PCR for diagnosis of infectious salmon anaemia virus (ISAV) in carrier
sea trout Salmo trutta after experimental infection.
AB - The emergence of infectious salmon anaemia virus (ISAV) in Canada and Scotland
and frequent new outbreaks of the disease in Norway strongly suggest that there
are natural reservoirs for the virus. The main host for the ISA virus is probably
a fish occurring in the coastal area, most likely a salmonid fish. Since sea
trout is an abundant species along the Norwegian coast, common in areas where ISA
outbreaks occur, and possibly a life-long carrier of the ISA virus, a study was
initiated to evaluate reverse transcriptase polymerase chain reaction (RT-PCR)
for diagnosis of the virus in experimentally infected trout. Several tissues
(kidney, spleen, heart and skin) were collected from the trout during a 135 d
period. The following diagnostic methods for detection of the ISA virus were
compared: cell culture (Atlantic Salmon Kidney, ASK cells), challenge of disease
free salmon with blood from the infected trout, and RT-PCR. The RT-PCR was the
most sensitive of these methods. With the help of this technique it was possible
to pick out positive individuals throughout the experimental period of 135 d.
Challenge of disease-free salmon were more sensitive than cell culture (ASK
cells). These 2 latter methods require use of the immunofluorescent antibody test
(IFAT) or RT-PCR for verification of presence of ISA virus.
PMID- 10785859
TI - An RT-PCR-based method for the diagnosis of the sleeping disease virus in
experimentally and naturally infected salmonids.
AB - The sleeping disease (SD) of rainbow trout (Oncorhynchus mykiss) is a worldwide
disease for which the causative agent, the sleeping disease virus (SDV), has been
recently characterized as an atypical alphavirus (Villoing et al. 2000). Up to
now, no diagnostic tools were available and thus no epidemiological studies have
been undertaken to evaluate the occurrence of this disease on the field. We
present in this paper a sensitive and highly specific 1 working day method, which
allows the detection of SDV from experimentally and naturally infected fishes.
This method, based on a reverse transcriptase/polymerase chain reaction (RT-PCR)
assay on total RNA extracted from SDV-infected fish organs, enables the specific
DNA amplification of part of the gene encoding the SDV glycoprotein E2, as early
as 2 d post-infection (d.p.i.) and as late as 70 d.p.i., at which time clinical
signs of infection are no longer apparent. Moreover, we show that this RT-PCR
method can be successfully used for the diagnosis of fish infected by a closely
related virus, namely salmon pancreas disease virus (SPDV). This report is the
first description of a very powerful diagnostic assay which could provide a more
accurate replacement for the classical virological, histological and
immunochemistry methods.
PMID- 10785860
TI - Immunization of cultured juvenile rockfish Sebastes schlegeli against Microcotyle
sebastis (Monogenea).
AB - To determine whether immunization with Microcotyle sebastis antigen could induce
protection against the parasite's establishment, naive juvenile rockfish were
immunized by injection or immersion with whole worm antigen of M. sebastis. The
infestation intensities of immunized groups following a challenge (2 wk after
boosting) with 5000 M. sebastis eyed-eggs were significantly lower than those of
control groups, when determined 7 wk postinfection. The fish in the groups
boosted with M. sebastis antigen showed stronger protection than unboosted
groups. The control group injected with FCA only showed a significantly smaller
number of worms than the control group, which was immersed in PBS containing
seawater. The results strongly suggest that both specific and nonspecific immune
factors participate in the protection of rockfish against M. sebastis
establishment.
PMID- 10785861
TI - The life cycle of Sphaerospora truttae (Myxozoa: Myxosporea) and some features of
the biology of both the actinosporean and myxosporean stages.
AB - A previously undescribed echinactinomyxon type actinosporean was shown
experimentally to be the alternate stage of Sphaerospora truttae. The
echinactinomyxon type spores were found to be released from Lumbriculus
variegatus and occasionally Tubifex tubifex. Overall infection prevalence of the
echinactinomyxon was 0.14%. Peak release was in March-May each year. S. truttae
spores developed in experimentally infected salmon 4.5 mo post-exposure to
echinactinomyxon spores. Extrasporogonic stages of S. truttae first appeared in
naturally infected salmon in early July and persisted for 8 to 10 wk. Correlation
between peak release of echinactinomyxon spores and appearance of extrasporogonic
stages of S. truttae is discussed.
PMID- 10785862
TI - Pathological changes caused by cold-water stress in Japanese eel Anguilla
japonica.
AB - In the present study, histopathological changes in Japanese eel Anguilla japonica
subjected to 'cold-water stress' were examined. Eels were exposed to cold water
(13 to 15 degrees C) and warmer water (25 degrees C) as controls. Fish held in
warm water did not show any apparent changes. Although none of the eels exposed
to cold water died, they displayed nephrotic changes such as cloudy swelling and
hyaline droplet degeneration of the renal tubular epithelia. Fish with nephroses
had low levels of serum chloride (12 to 23 mg l-1 in fish with hyaline droplet
degeneration, 71 to 81 mg l-1 in fish with cloudy swelling) compared with the
control fish (87 to 109 mg l-1). In electron microscopy, affected tubular cells
had variously damaged mitochondria and formations of secondary lysosomes of
variable sizes. Electron microscopy also revealed mitochondrial degeneration in
hepatocytes and degenerated granules of neutrophils in the hematopoietic tissue.
'Cold-water stress' was effective in damaging Japanese eels below 15 degrees C.
PMID- 10785863
TI - Some new observations on the cytopathology of fin erosion disease in winter
flounder Pseudopleuronectes americanus.
AB - A light and electron microscopic study was conducted on dorsal fin tissues
adjacent to acute fin erosion lesions in winter flounder from 2 polluted sites
(New York Bight region and New Haven Harbor) on the northeast Atlantic Coast. The
objective of this work was to evaluate these minimally affected, lesion
associated tissues which may precede the acute or severe stages of the disease.
The following 4 types of pathological conditions were found in the epidermis of
diseased fish from the 2 polluted sites: (1) epithelial cell hyperplasia; (2)
mucous cell hyperplasia and hypertrophy; (3) spongiosis; and (4) focal necrosis.
The latter 2 types of lesions have not been previously reported for fin erosion
in this species. Changes in the dermis associated with these lesions included
fibrosis, abnormal distribution of melanocytes, hyperemia and sclerosis of blood
vessels, and hemorrhage. The possibility that hypoxia may play a role in the
observed pathology is considered.
PMID- 10785864
TI - A survey of some parasites and diseases of several species of bivalve mollusc in
northern Western Australia.
AB - Pteriid oysters (Pinctada maxima, Pinctada margaritifera, Pinctada albina, Pteria
penguin), rock oysters (Saccostrea glomerata, Saccostrea cuccullata, Saccostrea
echinata) and representatives of other taxa (Malleidae, Isognomonidae, Pinnidae,
Mytilidae, Spondylidae, Arcidae) from the wild, and 4670 hatchery-reared P.
maxima, from northern and Western Australia, were examined for parasites and
diseases. Rickettsiales-like inclusions and metacestodes of Tylocephalum occurred
in most species. Intranuclear virus-like inclusions occurred in 1/415 wild P.
maxima, 1/1254 S. cuccullata, 3/58 Isognomon isognomum, 1/80 Pinna bicolor and
1/45 Pinna deltodes. Perkinsus was histologically observed in 1/4670 P. maxima
spat, 2/469 P. albina, 1/933 S. glomerata, 16/20 Malleus meridianus, 12/58 I.
isognomum, 1/45 P. deltodes, 5/12 Spondylus sp., 1/16 Septifer bilocularis and
3/6 Barbatia helblingii. One of 1254 S. cuccullata was heavily systematically
infected with Perkinsus merozoites, meronts and schizonts, and was patently
diseased. Other potentially serious pathogens included Haplosporidium sp. in
6/4670 P. maxima spat, Marteilia sydneyi from 1/933 S. glomerata, and Marteilia
sp. (probably M. lengehi) (1/1254) and Haplosporidium sp. (125/1254) from S.
cuccullata. The latter were associated with epizootics on offshore islands, with
heaviest prevalence (45%) in oysters with empty gonad follicles. Marteilioides
sp. infected the oocytes of 9/10 female S. echinata from Darwin Harbour. Details
of geographical distribution and pathology are given, and the health of the
bivalves examined is discussed.
PMID- 10785865
TI - Conservation of sequence in the internal transcribed spacers and 5.8S ribosomal
RNA among geographically separated isolates of parasitic scuticociliates
(Ciliophora, Orchitophryidae).
AB - Nucleotide sequence from the internal transcribed spacers (ITS1 and ITS2) and the
5.8S gene from the ribosomal RNA gene cluster of isolates of the scuticociliate
Orchitophrya stellarum from 4 asteroid hosts were compared. Surprisingly, these
data (495 bp) were identical for O. stellarum isolated from the testes of
Asterias amurensis from Japan; Pisaster ochraceus from British Columbia, Canada;
Asterias rubens from The Netherlands; and Asterias vulgaris from Prince Edward
Island, Canada. These sequence data were compared to those from 3 scuticociliates
which parasitise crustaceans: Mesanophrys pugettensis, M. chesapeakensis and
Anophryoides haemophila. No difference was found in this region between the
nucleotide sequence of M. pugettensis and M. chesapeakensis. The sequence of
Mesanophrys spp. differed by 9.2% in the ITS1 and 4.7% in the ITS2 from that of
O. stellarum. The sequence from the ITS1 (135 bp) and ITS2 (233 bp) of A.
haemophila differed by 42.6 and 20.5% respectively from those of O. stellarum.
Therefore, nucleotide sequence of the ITS regions in these scuticociliates is
highly conserved.
PMID- 10785866
TI - Sodium, potassium, calcium and magnesium and cardiovascular risk.
PMID- 10785867
TI - Salt, blood pressure and cardiovascular diseases.
AB - The rise in average blood pressure with age seen in Western populations does not
occur in isolated traditional nomadic communities. Several factors contribute to
the higher blood pressure in the West. Salt is particularly important, however,
because its effect on blood pressure is large, the dietary intake by Western
populations is high and a large reduction in its intake is realistic. The size of
the relationship between salt and blood pressure depends on age and, in trials,
the duration of reduction of intake of salt. Results of many of the randomized
trials have suggested that reduction of dietary salt exerts only a small effect
on average blood pressure; this is because their subjects have been young
(average age 26 years) and trials have been of short duration (average 2 weeks).
Analysis of observational data concerning various communities indicated that a
reduction in dietary intake of sodium of 100 mmol/24 h (3 g of salt, a realistic
reduction) lowers systolic blood pressure in subjects aged 50-65 years by 10 mmHg
on average. Much evidence corroborates this estimate, including data from the
Intersalt study and a randomized controlled trial of reduction of intake of salt
by older persons. This reduction in blood pressure would reduce age-specific
stroke mortality by an estimated 22% and mortality from heart disease by 16%.
Reducing the amount of salt added to manufactured foods is an important public
health target.
PMID- 10785868
TI - Salt and cardiovascular disease: clinical and epidemiological evidence.
PMID- 10785869
TI - Dietary potassium and cardiovascular disease: clinical applications.
PMID- 10785870
TI - Calcium intake and blood pressure: an update.
PMID- 10785871
TI - A review of the link between dietary magnesium and cardiovascular risk.
PMID- 10785872
TI - C282Y mutation in the HLA-H gene is not a risk factor for patients with
myocardial infarction.
AB - BACKGROUND: Iron is suspected to play a role in the development of
atherosclerosis and in the progression of the disease, and consequently in
myocardial infarction. Authors of a recent study identified a mutation in HLA-H
gene, C282Y, that is an excellent marker for hemochromatosis, which is the most
common cause of iron overload. There is a high prevalence of carriers of
heterozygous hemochromatosis, most of whom are asymptomatic even with
abnormalities of iron metabolism. OBJECTIVE: To study C282Y mutation in the HLA-H
gene of 173 survivors of myocardial infarction matched with 172 controls by age,
race, and sex, and 119 patients upon diagnosis of acute myocardial infarction.
METHODS: Identification of the mutation was performed by PCR amplification of the
DNA fragment followed by Rsal digestion. RESULTS: The prevalence of heterozygotes
for the mutated allele both among patients and among controls was 1.74%. None of
the 119 patients studied upon diagnosis was a carrier of the mutation.
CONCLUSION: Our data suggested that the most common cause of iron overload is not
associated with myocardial infarction.
PMID- 10785873
TI - Circulating lipoprotein profiles are modulated differently by lipoprotein lipase
in obese humans.
AB - BACKGROUND: Several genetic analyses have suggested that lipoprotein lipase (LpL)
genotypes causing decreased LpL activity correlate with increased triglyceride
concentrations and risk for coronary artery disease. In contrast, in some other
studies LpL activity was positively correlated with plasma low-density
lipoprotein (LDL) cholesterol concentrations. OBJECTIVE: To assess whether these
different associations represent physiologic differences in lipoprotein
metabolism. METHODS: We correlated postheparin lipase activities, postprandial
lipemia, and fasting lipoprotein concentrations in obese (BMI > or = 30 kg/m2, n
= 26) and non-obese (BMI < or = 30 kg/m2, n = 57) individuals. LpL was measured
using specific inhibitory antibodies. RESULTS: Surprisingly, LpL activity was
significantly correlated with triglyceride area under the curve after a fat load
in the non-obese, but not the entire group. Moreover, in non-obese individuals,
LpL activity correlated directly (r = 0.40) and hepatic lipase activity
correlated inversely (r = -0.32) with high-density lipoprotein (HDL) cholesterol
concentrations. These relationships were not found in the obese group, in whom
LpL correlated with LDL cholesterol concentrations (r = 0.54). CONCLUSIONS: We
conclude that postheparin LpL activity relates to different lipoproteins in obese
and non-obese individuals. In obesity, greater LpL activity may enhance
conversion of very-low-density lipoprotein cholesterol to LDL cholesterol,
whereas in non-obese individuals the correlation is with HDL cholesterol. Whether
this is due to differences in the source of LpL (muscle or fat), or to other
associated alterations in lipoprotein metabolism is unknown. These results may
explain the non-uniformity of correlations between LpL and atherogenic
lipoproteins in different populations.
PMID- 10785874
TI - Influence of high-density lipoprotein cholesterol and rheological factors on the
sex difference in cardiovascular disease.
AB - BACKGROUND: It is well established that the incidence of cardiovascular disease
among men is higher than that among women. OBJECTIVE: To determine whether
differences between men and women in terms of a range of conventional and
rheological risk factors could explain this sex difference. DESIGN: This was a
population-based cohort study (the Edinburgh Artery Study). METHODS: Men and
women aged 55-74 years (n = 1592) were selected at random from the general
population of Edinburgh and followed up for 5 years. Baseline cardiovascular risk
factors were measured and related to incidence of disease among men and women.
RESULTS: Men had higher levels of cigarette smoking, haematocrit and blood
viscosity and lower levels of low-density lipoprotein (LDL) cholesterol, high
density lipoprotein (HDL) cholesterol and plasma fibrinogen than did women. The
incidences of cardiovascular events among men and women were 48.3 and 26.1 per
1000 person-years, respectively. Adjustment for level of HDL cholesterol reduced
the male:female ratio for sex-specific incidence rates of cardiovascular events
from 1.80 [95% confidence interval (CI) 1.43-2.27] to 1.34 (95% CI 1.04-1.73).
This reduction was partially reversed after further adjustment for the other
cardiovascular risk factors. The impact of blood viscosity, plasma viscosity and
plasma level of fibrinogen on the risk of cardiovascular disease was higher for
men than it was for women (multivariate relative risk for blood viscosity were
1.24, 95% CI 1.08-1.43, for men and 0.81, 95% CI 0.61-1.06, for women).
CONCLUSIONS: Levels of HDL cholesterol levels in women being higher than those in
men may explain some, but not all, of the sex difference in incidence of
cardiovascular disease. Greater susceptibility of men to rheological factors
might also be important.
PMID- 10785875
TI - Rilmenidine in the hypertensive type-2 diabetic: a controlled pilot study versus
captopril.
AB - BACKGROUND: Rilmenidine is an innovative antihypertensive agent that binds
specifically to I1 imidazoline receptors. The antihypertensive efficacy of
rilmenidine in treating type-2 diabetics has been demonstrated, and is associated
with very good clinical and laboratory tolerance. DESIGN: This was a 6-month,
double-blind, randomized, controlled study comparing the effects of rilmenidine
and captopril on the progression of microalbuminuria in a population of patients
with mild-to-moderate hypertension [90 mmHg < diastolic blood pressure (DBP) <
110 mmHg], type-2 diabetes, and microalbuminuria (30 mg/24 h < urine albumin
excretion < or = 300 mg/24 h). RESULTS: Between month 0 and month 6, the mean
supine blood pressure was reduced in a similar manner by rilmenidine (systolic
blood pressure from 159 to 141 mmHg and diastolic blood pressure from 98 to 84
mmHg) and captopril (systolic blood pressure from 157 to 144 mmHg and diastolic
blood pressure from 101 to 82 mmHg). The median value for microalbuminuria was
reduced from 160 (90-260) to 56 (27-87) mg per 24 h by rilmenidine and from 144
(51-200) to 54 (41-123) mg per 24 h by captopril. Rate of clearance of creatinine
was not significantly changed during the study by either treatment (with
rilmenidine it varied from 95.2 to 95.6 ml/min; with captopril it varied from
86.2 to 90.4 ml/min). There was no statistical difference between the changes in
levels of glycosylated hemoglobin for the groups treated with rilmenidine and
captopril. Clinical and laboratory acceptabilities were good, and those for the
two groups were comparable. CONCLUSION: Rilmenidine exerts similar
antihypertensive effects to those of captopril on the hypertensive with type-2
diabetes. Decreases in microalbuminuria elicited by the two treatments do not
differ. That administration of rilmenidine decreases microalbuminuria suggests
that it could exert nephroprotective effects.
PMID- 10785877
TI - Bibliography. Current world literature.
PMID- 10785876
TI - A comparison of algorithms for initiation of lipid lowering therapy in primary
prevention of coronary heart disease.
AB - OBJECTIVE: To compare nine different algorithms for determining the necessity for
drug treatment of hyperlipidaemia in patients without cardiovascular disease.
DESIGN: Risk-factor data on 400 patients were obtained. Algorithms assessed
included the Framingham model, National Cholesterol Education Program, European,
British, New Zealand, British Regional Heart Study, Sheffield, Munster Heart
Study and Dundee guidelines and a local general rule for treatment of atheroma
(General Rule to Enable Atheroma Treatment). SETTING: Three hospital lipid
clinics. RESULTS: Patients were 56% male, aged 53.8 +/- 12.3 years, 38% smoked,
55% had a family history of disease (37% familial hypercholesterolaemia, 33%
hypertension and 5.2% left ventricular hypertrophy); 31% were moderately obese
and 15% were diabetic. The average cholesterol level was 7.9 +/- 2.6 mmol/l.
Median Framingham risk was 1.66%/year and this risk was > 2%/year for 37% and >
3%/year for 17.5%. Treatment was required for 86% by National Cholesterol
Education Program, 70% by General Rule to Enable Atheroma Treatment and European,
61% by New Zealand, 58% by British, 42% by Dundee, 40% by Munster Heart Study,
25% by British Regional Heart Study and 16% by Sheffield guidelines. Algorithms
varied regarding recommendations for treatment of men, women, patients with
familial hypercholesterolaemia and diabetes. Confounders included risk levels,
definitions and weightings for additional risk factors. CONCLUSIONS: Different
algorithms vary widely in their predictions of need for drug treatment of this
high-risk population with hyperlipidaemia. Authors of guidelines for
cardiovascular disease need to unify risk thresholds and definitions and audit
the effects of additional weighting factors so that patients can be treated
consistently.
PMID- 10785879
TI - Reduction of medical errors: an order.
PMID- 10785878
TI - An unusual anesthesia machine leak.
PMID- 10785880
TI - Cardiopulmonary morbidity as a complication of severe preeclampsia HELLP
syndrome.
AB - OBJECTIVE: To profile the types and frequencies of cardiopulmonary morbidity
encountered in patients with severe preeclampsia with or without hemolysis,
elevated liver enzymes, and low platelets (HELLP syndrome). STUDY DESIGN: We
initiated a retrospective study of 979 patients with severe preeclampsia with and
without HELLP syndrome. Types of cardiopulmonary morbidity were analyzed among
the three classes of HELLP syndrome and severe preeclampsia without HELLP
syndrome. RESULTS: Cardiopulmonary morbidity occurred in 7.6% of study patients.
As a group, patients with cardiopulmonary complications were more likely to have
cesareans (11% vs 6%, p = 0.019) earlier in gestation (1366 +/- 700 gm birth
weight versus 1734 +/- 892 gm birth weight, p = 0.021), with higher peak
postpartum blood pressures (< 0.001) and with more abnormal laboratory values
indicative of multisystem disease, compared with patients without this
complication. Patients with cardiopulmonary complications required almost twice
as long to achieve diuresis as comparison patients (22 +/- 23 hours versus 12 +/-
11 hours, p < 0.001). CONCLUSION: The probability of cardiopulmonary
complications increases significantly when patients develop class 1 HELLP
syndrome. Of all cardiopulmonary complications, acute lung injury/acute
respiratory distress syndrome is most specific to class 1 HELLP syndrome.
Transient renal dysfunction is closely related to cardiopulmonary morbidity.
PMID- 10785881
TI - Perinatal outcome of twin pregnancies with one structurally affected fetus: a
case-control study.
AB - OBJECTIVE: To determine whether one structurally affected fetus of a twin
pregnancy further increases the risk of preterm delivery and to compare perinatal
morbidity and mortality in these pregnancies with twin gestations with
structurally normal fetuses. STUDY DESIGN: The cases (n = 25) included all twin
gestations diagnosed from 1991 to 1994 with a sonographically detected fetal
anomaly and a structurally normal co-twin delivered after 24 completed weeks'
gestation. The control group consisted of 547 twin gestations delivered during
the study period with no sonographically detected structural anomalies in either
twin. RESULTS: Compared with controls, pregnancies with a single anomalous fetus
(cases) delivered at a significantly lower gestational age (mean +/- SD: 34.0 +/-
3.2 weeks versus 35.6 +/- 3.2 weeks; p = 0.019) and had a significantly increased
preterm delivery rate (76.0% vs 55.4%; p = 0.042). There was no significant
difference in the incidence of intraventricular hemorrhage or respiratory
distress syndrome, yet the perinatal mortality (80.0/1000 vs 6.4/1000; p = 0.000)
and the average nursery stay (45.5 +/- 43.3 days versus 17.0 +/- 24.0 days; p =
0.003) were significantly increased for cases compared with controls. In
addition, a significantly greater birth weight discordancy (> or = 30%) was seen
in cases compared with controls (32.0% versus 9.1%; p = 0.002). The normal co
twin did not show any significant difference in the perinatal outcome variables
studied when compared with controls. CONCLUSION: Compared with structurally
normal twin pairs, twin gestations with a single anomalous fetus are at a
significantly increased risk for preterm delivery. In addition, the anomalous
fetus, but not the structurally normal co-twin, has a significantly increased
mortality rate and a longer nursery stay. Finally, despite the increased risk for
preterm delivery in twin pregnancies with one anomalous fetus, it is the nature
of the anomaly itself that dictates the perinatal outcome.
PMID- 10785882
TI - Clinical experience in enteral nutrition support for premature infants with
bronchopulmonary dysplasia.
AB - OBJECTIVE: The comprehensive management of infants with bronchopulmonary
dysplasia (BPD) may include the need for fluid restriction. Modular nutrient
components added to preterm formulas increase energy and protein contents but may
compromise the nutrient integrity of the formula. The purpose of this pilot study
was to compare the nutritional status and feeding tolerance of infants fed either
a 30 kcal/oz ready-to-feed formula or a preterm formula containing nutrient
supplements. METHODS: Feeding tolerance, growth, and biochemical indicators of
nutritional status were compared in 27 premature infants with BPD who were fluid
restricted. These infants were fed either a 30 kcal/oz ready-to-feed formula or a
preterm formula with additives concentrated to 30 kcal/oz. RESULTS: Growth and
feeding tolerance were similar between groups. Serum albumin and blood urea
nitrogen concentrations, however, were improved in the ready-to-feed formula
group. CONCLUSION: A 30 kcal/oz ready-to-feed formula provides similar nutrient
composition but improved protein nutritional status; this formula is a safe
alternative to preterm formula containing multiple nutrient additives in
premature infants with BPD.
PMID- 10785883
TI - Prediction of postdischarge complications by predischarge event recordings in
infants with apnea of prematurity.
AB - OBJECTIVE: To determine whether predischarge event recording (PDER) can
accurately identify preterm infants with resolving apnea of prematurity (AOP) at
risk for postdischarge complications. DESIGN: PDER was performed on infants with
resolving AOP on caffeine, ready for discharge. The outcome of infants with
normal recordings was compared with that of infants with abnormal recordings.
Follow-up data were obtained for outcome. RESULTS: Of the 106 infants, 74 had a
normal PDER and 32 had an abnormal PDER (apneas lasting for > 20 seconds and/or a
heart rate of < 80 beats per minute for > 5 seconds). Birth weight, gestational
age at birth, length of stay, discharge weight, and duration of caffeine
treatment after discharge were no different between groups. None of the normal
PDER infants (0 of 74) had postdischarge complications, whereas 4 of 32 infants
with an abnormal PDER had complications (p < 0.05, power = 0.7). The positive
predictive value of a normal PDER and no postdischarge complications was 100%.
The positive predictive value of an abnormal PDER and an adverse outcome was
12.5%. CONCLUSION: Normal PDER accurately identifies infants at low risk for an
adverse outcome.
PMID- 10785884
TI - Effect of sepsis syndrome on neonatal protein and energy metabolism.
AB - OBJECTIVE: It was our hypothesis that septic illness would alter both protein and
energy metabolism in neonates, with elevations of tumor necrosis factor-alpha
(TNF-alpha), interleukin-6 (IL-6), and interleukin-1 beta (IL-1 beta) serving as
markers for these effects. STUDY DESIGN: A total of 31 infants with suspected
sepsis were enrolled into four groups: septic, sick-nonseptic, healthy-nonseptic,
and recovered septic infants. Degree of illness, oxygen consumption, nitrogen
balance, urine 3-methylhistidine/creatinine (MeH/Cr), and TNF-alpha, IL-6, IL-1
beta, and C-reactive protein (CRP) were measured. RESULTS: Oxygen consumption
increased, while nitrogen balance decreased and MeH/Cr increased with increasing
degree of illness. Nitrogen balance improved on recovery from sepsis. IL-6 and
CRP levels were elevated in septic infants compared with sick-nonseptic and
healthy infants. CONCLUSION: Neonates experience a hypermetabolic response with
increased nitrogen loss during septic illness, proportional to the degree of
illness. Increased delivery of protein substrate may be nutritionally
advantageous to the septic neonate.
PMID- 10785885
TI - Relationship between fetal monitoring and resuscitative needs: fetal distress
versus routine cesarean deliveries.
AB - BACKGROUND: There is debate as to whether pediatricians should be present at all
cesarean deliveries. Little published data exist regarding the differences in
resuscitative needs of infants delivered by cesarean section for "fetal distress"
versus those without this diagnosis. OBJECTIVE: To describe the differences in
resuscitative and immediate postnatal intervention needs for neonates with fetal
distress delivered by cesarean section and those without fetal distress delivered
in the same manner. Also, to devise an evaluation tool to assess and compare
levels of neonatal resuscitation between infants and groups of infants. METHODS:
The delivery records of 1411 term infants delivered by cesarean section after
uncomplicated pregnancies at Los Angeles County/University of Southern California
Medical Center from March 3, 1995 through March 8, 1997 were examined
retrospectively. Apgar scores and resuscitative needs were assigned to a newly
devised, weighted scoring system. Resuscitation subscores and total resuscitation
scores were compared using non-parametric methods. RESULTS: The fetal distress
group (n = 80) had a significantly greater resuscitative needs mean score (p <
0.001) and subscores (p < 0.001 to p = 0.004) than did the non-fetal distress
group (n = 419). Of the non-fetal distress group, 48.7% still received some
active form of intervention. CONCLUSION: In our study group, infants with fetal
distress had significantly greater intervention needs than infants without fetal
distress.
PMID- 10785886
TI - Ethnic differences in the rates of low birth weight attributable to differences
in early motherhood: a study from the Third National Health and Nutrition
Examination Survey.
AB - OBJECTIVE: To estimate the impact of early motherhood (being a mother at < 20
years of age) on ethnic differences in the risk of low birth weight (LBW) in a
representative sample (n = 9141) of American infants and children. METHODS: Risks
for LBW and the population-attributable fraction due to early motherhood were
estimated adjusting for maternal smoking and education in logistic regression
models. The contribution of early motherhood to ethnic differences in the risks
of LBW was determined using a relative attributable risk estimate that compared
Hispanics and Blacks with Whites. RESULTS: Early motherhood was independently
associated with increased risk of LBW in each of the three ethnic groups,
adjusting for maternal smoking during pregnancy and education. Hispanic and Black
ethnicity were each associated with 15% and 123% increased risk of LBW relative
to Whites. The population-attributable fractions of LBW due to early motherhood
were 6.2%, 7.4%, and 2.3%, for Whites, Hispanics, and Blacks, respectively. The
responses of early motherhood for LBW were different among the three ethnic
groups (p < 0.05). Adjusting for maternal smoking and education, 4.8% and 7.4% of
the differences in the risk of LBW between Whites and Hispanics and between
Whites and Blacks, respectively, were due to differences in early motherhood.
CONCLUSION: The result of this study underscores the risk of LBW due to early
motherhood. Because early motherhood is preventable and avoidable, appropriate
public health strategies to educate young women on the need to delay childbearing
in these ethnic groups, particularly among Hispanics and Blacks, are warranted.
PMID- 10785887
TI - Teaching residents in the neonatal intensive care unit: a non-traditional
approach.
AB - Because of the increasing constraints on the amount of time pediatric residents
may train in the neonatal intensive care unit (NICU), concerns have been raised
about the adequacy of their exposure to acute emergencies in the delivery room
and their hands-on experience with sick neonates. Importantly, there are also
concerns about the consistency and quality of supervision of PL-1 residents by
second- and third-year residents, who themselves may not have had sufficient
training in the NICU. To address these concerns, we have instituted an
educational plan that links an experienced neonatal nurse practitioner (NNP) one
on-one with a PL-1 resident in a collaborative team. This plan differs from the
traditional resident-to-resident supervisory model. An anonymous survey of our
residents (n = 14) indicates enthusiastic endorsement of this new educational
model. NNPs as first-line teachers in the NICU provide a new approach for
residency training programs.
PMID- 10785888
TI - A comparative study of serum soluble vascular cell adhesion molecule-1 and
soluble intercellular adhesion molecule-1 in preeclampsia.
AB - OBJECTIVES: Maternal serum soluble vascular cell adhesion molecule-1 (sVCAM-1)
and soluble intercellular adhesion molecule-1 (sICAM-1) were evaluated in
preeclampsia to investigate whether these molecules could be helpful with regard
to this pregnancy complication. STUDY DESIGN: The study population was composed
of 30 preeclamptic patients with a mean gestational age of 35.5 +/- 4.6 weeks and
20 age-matched and gestational age-matched normotensive uncomplicated pregnancies
(controls). Blood samples from 7 of the 30 preeclamptic patients and 15 of the 20
controls in the second trimester were also analyzed. Data were analyzed by
parametric methods. RESULTS: Significantly higher maternal serum sVCAM-1 levels
were found in both groups of preeclamptic patients with and without fetal growth
restriction (981 +/- 145 ng/ml; n = 13; p < 0.0005 and 846 +/- 84 ng/ml; p <
0.02, respectively) compared with controls (668 +/- 186 ng/ml). In contrast, no
significant difference was found in maternal serum sICAM-1 levels between
preeclamptic and normotensive pregnancies, or in both adhesion molecules (1) in
the controls between second and third trimester samples and (2) in the second
trimester between pregnant women who developed preeclampsia later and gestational
age-matched controls. CONCLUSION: These findings show a selective significant
elevation of maternal serum sVCAM-1 in preeclampsia, with the highest values in
cases complicated with fetal growth restriction, perhaps reflecting its
angiogenic function. Hence, sVCAM-1 could be helpful in the diagnosis of this
fetal complication in preeclampsia.
PMID- 10785889
TI - Glutaric aciduria type II: observations in seven patients with neonatal- and late
onset disease.
AB - The clinical, biochemical, and neuroradiologic findings and clinical follow-up of
seven patients with glutaric aciduria type II are reported. Three phenotypes of
the disease are encountered: neonatal-onset form with congenital anomalies (two
patients) or without congenital anomalies (three patients) and late-onset form
(two patients). The neonatal-onset form presents as an overwhelming illness, with
severe hypoglycemia and metabolic acidosis leading to rapid death. Frequently it
is associated with perinatal energy deprivation, a neonate with low birth weight
and prematurity. The late-onset form presents with intermittent episodes of
vomiting, hypoglycemia, and acidosis especially after meals rich in fat and/or
proteins. All parents are consanguineous and have a first- or second-degree
relationship. Initially, in the two phenotypes with neonatal onset and during
crisis in the late-onset phenotype, routine laboratory evaluation showed severe
metabolic acidosis, with an increased anion gap, hypoglycemia without ketonuria,
and disturbed liver function tests. In the majority of patients with neonatal
onset forms, the kidneys, liver, and at times the spleen are enlarged with an
increased echogenic pattern; however, no hepatic or renal cysts are detected.
Cardiomegaly is observed in most patients. The diagnosis can be easily and
rapidly reached through tandem mass spectrometry study of the blood and can
further be confirmed by gas chromatography/mass spectrometry analysis of the
urine organic acids. In this report, the magnetic resonance imaging/computed
tomography brain studies showed brain atrophy, white matter disease, and in one
patient, fluid-filled cavities in the periventricular area and putamina. Fluorine
18-labeled 2-fluoro-2-deoxyglucose positron emission tomographic (FDG PET) brain
studies in two patients with late-onset disease showed slightly decreased
activity in the cerebral cortex in one and in the caudate nuclei in the other.
Brain FDG PET scan and magnetic resonance spectroscopy were normal in one patient
with neonatal-onset disease. All patients were treated with a diet low in fat and
protein, oral riboflavin, and carnitine. The results were promising for the late
onset disease. Intravenous carnitine gave rewarding results in one patient with
neonatal-onset disease.
PMID- 10785890
TI - Parvoviral infection associated with increased nuchal translucency: a case
report.
AB - An increased fetal nuchal translucency detected by first trimester ultrasound has
been associated with an elevated risk of aneuploidy. The etiology of the
increased nuchal translucency in fetuses with normal chromosomes is uncertain,
but it has been associated with poor pregnancy outcome. We report a fetus with
increased nuchal translucency and a normal karyotype, in which parvovirus was
detected by polymerase chain reaction in the amniotic fluid. Although an
ultrasound detected an increased nuchal fold thickness in the second trimester,
the pregnancy was otherwise uncomplicated. Parvovirus should be considered as a
possible etiology of increased nuchal translucency. The risks to a fetus with
first trimester parvovirus infections diagnosed under these conditions are
uncertain and require larger studies.
PMID- 10785891
TI - Persistent central diabetes insipidus presenting in a very low birth weight
infant successfully managed with intranasal dDAVP.
AB - We report a case of a premature very low birth weight infant who presented
shortly after birth with idiopathic central diabetes insipidus that persisted
beyond the neonatal period and has been successfully managed with intranasal 1
desamino-8-D-arginine vasopressin. Although this condition is rare in neonates,
early recognition, evaluation, and therapy may prevent more severe morbidity.
Long-term successful management resulting in normal growth and development during
infancy can be achieved with intranasal 1-desamino-8-D-arginine vasopressin
therapy.
PMID- 10785892
TI - Special imaging casebook. Ventriculus terminalis.
PMID- 10785893
TI - Neonatal intensive care unit (NICU)
PMID- 10785894
TI - Work in the neonatal field.
PMID- 10785895
TI - Reader clarifies concepts of structured exercise programs in managing fatigue.
PMID- 10785896
TI - Article on deep vein thrombosis should address primary brain tumors.
PMID- 10785897
TI - Chemotherapy-induced hair loss is a profound human experience.
PMID- 10785898
TI - Practice tips from the Queen's Medical Center in Honolulu, HI.
PMID- 10785899
TI - Beyond the Supreme Court decision: nursing perspectives on end-of-life care.
AB - PURPOSE/OBJECTIVES: To describe nurses' views of care of the terminally ill.
DESIGN: Descriptive cross-sectional survey. SAMPLE: 300 nurses who completed a
survey published in Nursing98 and Nursing Management and 2,033 nurses randomly
selected from the Oncology Nursing Society (N = 2,333). METHODS: Mailed end-of
life (EOL) care survey. MAIN RESEARCH VARIABLES: Dilemmas, barriers, and
effectiveness of EOL care and education and attitudes regarding assisted suicide
and euthanasia. FINDINGS: EOL care dilemmas are common in nursing practice, and
many barriers exist to providing quality EOL care. Issues of euthanasia and
assisted suicide are particularly significant to nurses who struggle to provide
pain and symptom relief amid a system characterized by deficiencies in EOL care.
CONCLUSIONS: Improved care is contingent on adequate education of nurses as the
primary caregivers of patients and families who are facing the end of life. Study
findings provide direction for improved care of the terminally ill. IMPLICATIONS
FOR NURSING PRACTICE: Oncology nurses are centrally involved in care of the
terminally ill. Major reform is needed to provide quality EOL care.
PMID- 10785900
TI - Issues related to the use of genetic material and information.
AB - PURPOSE/OBJECTIVES: To review issues regarding the use of genetic materials and
information. DATA SOURCES: Professional literature, regional and federal
legislation. DATA SYNTHESIS: An analysis is provided of the relationship among
advances in genetic technology, use of genetic material and information, and the
development of laws that protect the interests of donors, researchers, and
insurers. Rapid technological achievements have generated complex questions that
are difficult to answer. The Human Genome Project began and the scientific
discoveries were put to use before adequate professional and public debate on the
ethical, legal, social, and clinical issues. The term "proper use" of genetic
material and information is not defined consistently. An incomplete patchwork of
protective state and federal legislation exists. CONCLUSIONS: Many complicated
issues surround the use and potential misuse of genetic material and information.
Rapidly advancing technology in genetics makes it difficult for regulations that
protect individuals and families to keep pace. IMPLICATIONS FOR NURSING PRACTICE:
Oncology nurses need to recognize their role as change agents, understand genetic
technology, and advocate for patients by participating in the debate on the
proper use and prevention of misuse of genetic material and information.
PMID- 10785901
TI - Bone marrow transplantation: the battle for hope in the face of fear.
AB - PURPOSE/OBJECTIVES: To describe patients' experience of having an autologous bone
marrow transplantation (BMT). DESIGN: Hermeneutic phenomenologic, descriptive,
and interpretive. SETTING: Outpatient treatment area of a comprehensive cancer
center in the Southwest. SAMPLE: 20 adult survivors of autologous BMT, 15 women
and 5 men, with a mean age of 46 years. METHODS: Content analysis of verbatim
transcriptions of open-ended interviews using hermeneutic phenomenology, which
combines descriptive and interpretive phenomenology. CONCLUSIONS: These patients
illustrate that fear, a predominant reality when undergoing autologous BMT, is
balanced with hope for survival. The overarching fear, fear of death, often was
related to the unknown, including cancer recurrence. The fear of the unknown also
came from being unprepared physically and emotionally. Losses were intertwined
with these fears and included loss of both control and trust in one's body.
Patients discussed fear of leaving the hospital and not having someone
"constantly looking at you to make sure that the cancer isn't back." These fears
and losses changed patients' view of life and led to a need for help in bringing
closure to the experience. IMPLICATIONS FOR NURSING PRACTICE: Specific nursing
actions to help allay fear include providing information about both feelings and
procedures, giving opportunities to discuss fears and losses, arranging meetings
with others who have had a BMT or suggesting an appropriate support group, and
including family in all interventions, as appropriate. Reducing fears with these
interventions helped patients maintain hope. By understanding the relationship
between hope and fear, nurses caring for people having BMT can use specific
strategies to decrease fear, hence increasing hope in patients. Nursing education
can emphasize the need to adequately prepare patients. Further research is
indicated to explore the effectiveness of interventions to prepare patients for
BMT and the interplay between hope and fear.
PMID- 10785902
TI - Effectiveness of oral 5-HT3 receptor antagonists for emetogenic chemotherapy.
AB - PURPOSE/OBJECTIVES: To review the efficacy and safety of the oral 5
hydroxytryptamine3 (5-HT3) receptor antagonists and the use of oral and i.v.
antiemetic therapy during and after hospital admission. DATA SOURCES: Articles in
medical and nursing literature. DATA SYNTHESIS: Use of oral antiemetics may help
patients avoid potential complications associated with i.v. administration and be
more convenient. They also are likely to lower staff and materials costs compared
to i.v. formulations. Oral granisetron is the only oral antiemetic approved in
the United States for use with highly emetogenic chemotherapy regimens. Oral
dolasetron and ondansetron are indicated for use with moderately emetogenic
chemotherapy. CONCLUSIONS: Oral therapy is preferable to i.v. formulations for
most patients. The oral 5-HT3 receptor antagonists approved for chemotherapy
induced nausea and vomiting include dolasetron, granisetron, and ondansetron.
Oral granisetron is differentiated for its safety, efficacy, and use in highly
and moderately emetogenic chemotherapy. IMPLICATIONS FOR NURSING PRACTICE: Oral
antiemetics are preferable to i.v. antiemetics because of decreased total costs
and greater convenience for patients who are able to ingest oral medication.
PMID- 10785903
TI - Relaxation and imagery for symptom management: improving patient assessment and
individualizing treatment.
AB - PURPOSE/OBJECTIVES: To discuss and describe the role of relaxation and imagery in
the care of patients with cancer, including suggestions for enhancing assessment
and brief instructions for implementing basic interventions. DATA SYNTHESIS:
Relaxation and imagery are commonly used to treat various side effects of cancer
and its treatment. The nursing literature often has encouraged nurses to use
relaxation and imagery to assist patients in managing pain, nausea, vomiting, and
anxiety. Frequently, the literature has presented these techniques as being
simple, harmless interventions requiring little assessment, planning, or
individualization. CONCLUSIONS: Simplistic, generalized approaches may result in
suboptimal treatment or deleterious responses. IMPLICATIONS FOR NURSING PRACTICE:
Clinicians must assess and collaborate with patients in developing an appropriate
strategy that fits the individual's preferences and beliefs.
PMID- 10785904
TI - Dietary restrictions for patients with neutropenia: a survey of institutional
practices.
AB - PURPOSE/OBJECTIVES: To describe institutional practices related to dietary
restrictions for patients with neutropenia to determine whether restrictions are
used and when they are implemented and discontinued. DESIGN: Descriptive survey.
SAMPLE: 156 institutions belonging to the Association of Community Cancer
Centers. METHODS: Mailed survey. FINDINGS: Of the institutions surveyed, 78% (n =
120) placed patients with neutropenia on restricted diets. Participating
institutions responded that patients were placed on restricted diets at a variety
of different white blood cell and neutrophil counts, including neutrophils <
1,000 (43%) and < 500 (46%). The majority of institutions (92%) placed patients
on restricted diets once neutropenia was documented, while only 9% of
institutions restricted diets when cancer treatment was initiated. Of the
participating institutions, 83% (n = 96) restricted diets only when patients were
neutropenic rather than throughout the duration of the chemotherapy regimen. The
most commonly restricted foods were fresh fruits and juices (92%), fresh
vegetables (95%), and raw eggs (74%). Few institutions restricted tap water
(12%). Wine was restricted at 39% of institutions, and beer was restricted at 40%
of institutions. CONCLUSIONS: The role of diet in the development of infection in
patients with neutropenia is unclear. This unclear role contributes to the
variation in dietary restrictions among institutions. IMPLICATIONS FOR NURSING
PRACTICE: Additional research should focus on dietary factors contributing to
neutropenic infections and establishing criteria for implementation of specific
dietary modifications. Nursing assessment should include nutritional status and
risk factors for neutropenia and bacterial translocation. Nursing protocols for
neutropenic dietary restrictions should be based on research findings.
PMID- 10785905
TI - Chemotherapy extravasation from implanted ports.
AB - PURPOSE/OBJECTIVES: To describe the four primary causes of extravasation from
implanted ports. DATA SOURCES: Journal articles, textbooks, medical records,
depositions, serial photographs, and the authors' personal experiences. DATA
SYNTHESIS: Extravasation from ports can occur by four major mechanisms:
incomplete needle placement and needle dislodgment, thrombus or fibrin sheath
formation, perforation of the superior vena cava, and catheter fracture. The
degree of tissue injury can vary but may be severe enough to require that a
simple mastectomy be performed to manage chest wall necrosis. CONCLUSIONS:
Extravasation is a known risk of chemotherapy administration via implanted ports.
Vesicants should be administered only after a blood return has been obtained and
the needle inserted into the port septum has been adequately secured.
IMPLICATIONS FOR NURSING PRACTICE: Extravasation of vesicant drugs from ports can
cause tissue necrosis and may prompt litigation. Risk-management strategies
include careful assessment and use of ports, comprehensive patient teaching about
the risk of extravasation and measures to decrease the likelihood of needle
dislodgment, and development of extravasation-management policies that address
port extravasations.
PMID- 10785906
TI - Case reports in physiotherapy.
PMID- 10785907
TI - Predicting motor recovery of the upper limb after stroke rehabilitation: value of
a clinical examination.
AB - BACKGROUND AND PURPOSE: Only a few studies have been conducted to predict motor
recovery of the arm after stroke. The aims of this study were to identify which
clinical variables, assessed at different points in time, were predictive of
motor recovery, and to construct useful regression equations. METHOD: One hundred
consecutive stroke patients who had an obvious motor deficit of the upper limb
were evaluated on entry to the study (two to five weeks post-stroke) and at two,
six and 12 months after stroke. The Brunnstrom-Fugl-Meyer test was used as the
outcome measure. Predictors included demographic data, overall disability,
clinical neurological features, neuropsychological factors and secondary shoulder
complications. RESULTS: In multiple regression analyses, motor performance was
invariably retained as the predictive factor with the highest R-square. Other
significant predictive variables were overall disability, muscle tone,
proprioception and hemi-inattention. Between 53% and 89% of the total amount of
variance was accounted for in all selected models. The accuracy of prediction
from clinical measurement in the acute phase diminished as the time span of
measurement of outcome increased. Similarly, assessment of the variables at two
and six months, rather than in the acute stage, resulted in a considerable
improvement in the percentage variance explained at 12 months. The highest
accuracy was obtained when predictions were made step-by-step in time.
CONCLUSIONS: It is possible to predict motor recovery of the upper limb
accurately through the use of a few clinical measures. Predictive equations are
proposed, the use of which are practicable in both clinical practice and
research.
PMID- 10785908
TI - Validity of weight distribution and sway measurements of the Balance Performance
Monitor.
AB - BACKGROUND AND PURPOSE: The Balance Performance Monitor (BPM) is a device which
provides auditory and visual feedback on weight distribution and the magnitude of
lateral and anterior-posterior sway during quiet standing. This study
investigated the validity of the measurements provided by the BPM using a Kistler
force plate (KFP) as the gold standard. METHOD: Percentage weight distribution
between the BPM foot plates was validated using both a series of calibration
weights and the vertical component of ground reaction force, measured by the KFP,
during normal standing in 18 young normal subjects. The lateral and anterior
posterior sway indices from the BPM were validated against the standard deviation
of the position of the centre of pressure, again obtained using the KFP, during
normal standing with eyes open and eyes closed and standing with feet together
with eyes open. Concurrent validity of the percentage weight distribution
measurements was assessed by calculating the 'limits of agreement' between the
corresponding measurements from the BPM and KFP and the 95% confidence intervals
for these 'limits'. Differences in the units of measurement obtained from the BPM
and KFP resulted in the concurrent validity of the sway indices being assessed
using correlation and regression. RESULTS: Excellent agreement was found between
the percentage weight distribution values provided by the BPM and the KFP, which
showed that the BPM may read only 3% of body weight above or below that given by
the KFP. High correlations (r = 0.61-0.99) were found between both the lateral
and anterior-posterior sway indices from the BPM and the motion of the centre of
pressure from the KFP in the respective direction. Despite this, further analysis
of regression equations and the 95% prediction intervals showed poor concurrent
validity of the BPM sway indices in relation to KFP measurements. This was
thought to be due to the different methods by which the sway indices and the
motion of the centre of pressure were calculated. CONCLUSIONS: The BPM may be
used to provide a valid measure of the symmetry aspect, but not necessarily the
steadiness aspect of postural control.
PMID- 10785909
TI - Functional status among elderly Norwegian fallers living at home.
AB - BACKGROUND AND PURPOSE: Falls and their after-effects are important contributors
to disability in old age, but may be mitigated. The relationship between self
reported health and functioning and falling is examined in the present study.
METHOD: The study design was cross-sectional. Data were collected from interviews
with 431 community-dwelling Norwegian subjects aged 67-97 years. Physical health
was assessed through items from the Multidimensional Functional Assessment of
Older Adults (MFAQ), supplemented with the Body Mass Index (BMI). General
health/psychosocial health was assessed with the General Health Questionnaire
(GHQ-20), the Mini-mental State Examination, two general health items and items
concerning mental and social health from the MFAQ. Falls during the last six
months were registered and scored 0 (no falls), 1 (one fall) or 2 (two or more
falls). RESULTS: During the previous six months 24.1% of subjects reported
falling. Four variables: 'Perceived difficulty in keeping balance in walking',
'Troubled by heart pounding/shortness of breath', sum score on the GHQ factor
'Depression/hopelessness', and a higher value on BMI, were independently
associated with number of falls reported. CONCLUSIONS: Score value on 'Perceived
difficulty in keeping balance in walking' was the strongest significant predictor
of falls in the present study. In contrast with other studies, no association
between anxiety, general health and falling was observed.
PMID- 10785910
TI - Effects of a three-month therapeutic exercise programme on flexibility in
subjects with low back pain.
AB - BACKGROUND AND PURPOSE: Spinal and muscle flexibility have been studied
intensively and used clinically as outcome measurements in the rehabilitation of
subjects with low back pain. The results of previous studies are contradictory
and there is a lack of longitudinal data on the effects of long term therapeutic
exercise on flexibility. METHOD: A controlled experimental study was conducted to
determine the effects of progressive therapeutic exercise on spinal and muscle
flexibility. Eighty-six chronic low back pain subjects fulfilled the inclusion
criteria and were divided into three study groups: (1) intensive training group,
(2) home exercise group and (3) control group. The intervention period lasted
three months and measurements were performed at both the beginning of the study
and immediately after intervention. Follow-up measurements were carried out six
and 12 months after baseline. Spinal flexibility was measured with lumbar
flexion, extension, spinal lateral flexion and rotation, and muscle flexibility
was measured with measurements of erector spinae, hamstring and iliopsoas
muscles. Also self-reported outcomes of the Oswestry Index and Borg Scale--Back
Pain Intensity were used. Associations between change (pre- to post-treatment)
were determined for the dependent variables. RESULTS: The results showed no
correlation between flexibility, the Oswestry Index or back pain intensity. After
the first three-month period lumbar flexion, extension and spinal rotation
decreased among all subjects. Spinal rotation and erector spinae muscle
flexibility improved significantly with intensive training. At the nine-month
follow-up, erector spine flexibility was still greater than at baseline.
Hamstring flexibility increased among the intensive training and home exercise
groups from pre- to post-intervention. However, the degree of hamstring
flexibility gained during training was subsequently lost following the period
without programmed exercise in both training groups. Self-reported outcome
variables showed positive changes among the three study groups after the
completion of intervention period, but these changes were only able to be
maintained during subsequent follow-ups for the intensive training and home
exercise groups. CONCLUSIONS: The findings suggest that flexibility does not play
an important role in coping with chronic low back pain for subjects whose
functional limitations are not severe. Also, it appears that the achieved gains
in spinal and muscle flexibility may not be able to be maintained without
continued exercise.
PMID- 10785911
TI - Treatment of focal spasticity with botulinum toxin: effect on the 'positive
support reaction'.
PMID- 10785912
TI - [Brachytherapy in the curative treatment of localized prostatic cancer].
AB - The treatment of clinically localized prostate cancer is based on total
prostatectomy, radiotherapy or surveillance. The adverse effects of these
treatments have led to an increasing interest in alternatives with decreased
morbidity. Brachytherapy consists of placing radioactive sources in the prostatic
tissue. High doses can therefore be delivered to the cancer while avoiding
excessive irradiation of the bladder and rectum. Brachytherapy generally uses
permanent implants (Iodine 125 or Palladium 103). The so-called Seattle technique
requires planning before implantation, while, in the "ProCeed" technique, the
position of the grains is determined at the time of treatment, with the help of a
computer programme which determines the dosimetry. Brachytherapy is a reliable
and reproducible technique with minimal morbidity, providing 10-year results
comparable to those of total prostatectomy.
PMID- 10785913
TI - [Diabetes and urination disorders].
AB - Diabetic neuropathy of can induce multi-organ dysfunction. The diabetes
simultaneously has profound repercussions on gastrointestinal, sexual and
erectile functions. One of the main sequelae of diabetic neuropathy is autonomic
neuropathy affecting the vesicosphincteric control. The objective of this study
was to review the epidemiological, clinical, laboratory and therapeutic data
concerning voiding disorders observed in diabetes. Although the therapeutic
management of an isolated voiding disorder in diabetics still remains
symptomatic, it raises aetiological problems due to the comorbidity, particularly
prostatic obstructive syndromes in men, pelvic dysfunction in women and ageing.
Diabetic patients in renal failure also present specific vesicosphincteric
disorders which are reviewed. Diabetic patients should be more systematically
screened for the development of diabetic bladder disease, especially for
associated factors which participate in its clinical expression. This implies
extreme caution in the management of benign prostatic hyperplasia in the case of
comorbidity, to avoid deteriorating a sometimes fragile detrusor-sphincter
equilibrium. Diabetic detrusor hyperactivity must be better known in order to be
more effectively detected. Pharmacological treatment of this condition raises
problems related to detrusor hypocontractility also related to diabetic bladder
disease. Clinical examination should be able to select those patients requiring
further urodynamic studies in order to assess the individual detrusor-sphincter
equilibrium. These investigations are required when surgical treatment of an
associated urological or gynaecological disorder is considered.
PMID- 10785914
TI - [Treatment of ureteral calculi: report of 152 calculi].
AB - OBJECTIVE: To define the therapeutic approach to ureteric stones. MATERIAL AND
METHODS: 137 patients with 152 ureteric stones were treated between January 1990
and January 1997. Sixty seven stones (44%) were situated in the lumbar ureter, 16
stones (10%) were in the iliac ureter, 69 stones (46%) were in the pelvic ureter.
These stones were treated by extracorporeal shock-wave lithotripsy (ESWL),
ureteroscopy and, more rarely, ureterotomy. RESULTS: One hundred and three stones
were treated in a single session, while 31 required two ESWL sessions. Treatment
eliminated 82% of ureteric stones: 89% of lumbar ureteric stones, 31% of iliac
stones and 85% of pelvic stones. Ureteroscopy was performed as first- or second
line treatment in 34 cases. It successfully treated 97% of ureteric stones: 100%
of pelvic and lumbar stones and 91% of iliac stones. Three patients were
successfully treated by ureterolithotomy for a lumbar ureteric stone and two for
iliac ureteric stones. CONCLUSION: SWL is the reference treatment for stones of
the lumbar ureter. Ureteroscopy is justified after failure of ESWL for stones of
the pelvic and iliac ureter, as it gives excellent results.
PMID- 10785915
TI - [Cacchi and Ricci's disease. Radiology, epidemiology and biology].
AB - OBJECTIVES: Medullary sponge kidney corresponds to the precaliceal dilatation of
renal tubules. The purpose of this article is to draw attention to some of the
radiological, epidemiological and laboratory features of this disease. MATERIAL
AND METHOD: 500 cases of radiopaque renal stones, corresponding to 310 men and
190 women, were reviewed. One or several urographies, early urographic films, and
blood calcium phosphate and 24-hour urinary calcium phosphate and oxalate
assessments were available for all subjects. We have added to this series an
identical study on 100 cases of stones in North African subjects. RESULTS: From a
radiographic point of view, this study shows the value of early urography films,
performed between the 2nd and 4th minutes after intravenous injection of
iodinated contrast agent, which visualize abnormal opacification of the renal
pyramids, before or at the same time as that of the bases of the calices. A
radiological sign, not reported in the medical literature, is a clear border
between abnormal opacification of the papillae and that of the calices, observed
in one or several papillocaliceal zones, which facilitates the diagnosis of
medullary sponge kidney. In this series of 500 cases of renal stones, the
radiological diagnosis of medullary sponge kidney was established in 103 cases:
20.6%. The distribution varies according to sex, 54 out of 310 (12.59%) in men,
53 out of 190 (27.89%) in women; difference p < 0.001. We found only 3 cases of
medullary sponge kidney in the series of 100 cases of radiopaque stones in North
African subjects. In terms of laboratory parameters, 24-hour urine tests showed
hypercalciuria in 61 out of 103 cases (59.22%), or hyperoxaluria in 66 out of 103
cases (64.08%), while 41 out of 103 cases (39.81%) presented both disorders.
Urinary calcium oxalate assessments were normal in 20 out of 103 cases (19.42%).
Hyperparathyroidism was never detected in combination with medullary sponge
kidney. CONCLUSION: This study shows the value of early urography films for the
diagnosis of medullary sponge kidney and demonstrates a useful diagnostic
radiological sign: a clear border between abnormal urographic opacification of
the papillae and calices. It shows the much higher frequency of medullary sponge
kidney in patients with radiopaque stones, with a higher rate in women than in
men, and a low frequency in North African subjects, that needs to be confirmed.
This study also emphasizes the frequency of hypercalciuria and especially
hyperoxaluria, and even the combination of these two disorders in medullary
sponge kidney.
PMID- 10785916
TI - [Kock's pouch: experience and clinical course in 31 patients].
AB - OBJECTIVES: To analyse the morbidity and functional results of Kock's continent
urinary diversion performed since 1992 in cystectomized patients in whom the
urethra could not be used. MATERIAL AND METHODS: From March 1992 to June 1998, 31
Kock's pouches were performed by 2 surgeons on a group of patients with a mean
age of 54 years. Henriet's technique was used in 23 patients until 1996, and was
then modified the last 8 patients in order to create a continent valve. The
diversion was performed after cystectomy for bladder or gynaecological tumour in
23 cases and 1 urinary tract reconstruction in 8 cases (neurogenic bladder,
destroyed urethra, conversion of Bricker diversion). RESULTS: With a mean follow
up of 42 months (12 to 84), the perioperative mortality was 3.4% and immediate
complications were 26%, justifying reoperation in 6.4%. Late complications
predominantly consisted of disinvagination of the valve with a reoperation rate
of 13%. No surgical revision for newly modified antireflux valves has been
performed since 1996. The continence rate of the system, evaluated between 3 and
6 months, was 90%. CONCLUSION: Kock's pouch is a delicate operation, clearly
associated with a high morbidity in this series, as in the literature, although
the results improved with experience. Indications must be confined to patients in
good general condition, motivated for self-catheterization (ATS) and in whom the
urethra cannot be used for bladder replacement.
PMID- 10785917
TI - [Stenosis following a direct uretero-ileal anastomosis technique in substitutive
enterocystoplasty].
AB - OBJECTIVES: Stenosis of the uretero-ileal anastomosis and reflux are the
commonest causes of secondary deterioration of renal function following
enterocystoplasty. Various direct anastomosis and antireflux techniques have been
proposed in order to reduce the risk of stenosis and reflux. In this
retrospective study, the authors evaluated the risk of stenosis and reflux after
right uretero-ileal anastomosis on an invaginated ileal loop. MATERIAL AND
METHODS: The authors evaluated the uretero-ileal anastomosis stenosis and reflux
rate and problems of the invaginated ileo-ileal valve in 157 patients after
bladder replacement enterocystoplasty. RESULTS: The anastomosis stenosis rate was
3.8% (6/157 patients) and all 6 patients were reoperated. Stenotic complications
on the valve were observed in 1.2% of cases (2/157 patients). The total stenosis
morbidity was 5% (8/157 patients). CONCLUSION: Direct end-to-end uretero-ileal
anastomosis is the simplest technique associated with the lowest risk of
stenosis. The low stenosis rate associated with invaginated valves is due to a
modification of the valvular system (limitation of the mesenteric exclusion
manoeuvre, external anchorage of the invagination and fixation by two lines of
resorbable staples).
PMID- 10785918
TI - [Morbidity of endoscopic prostatic resection: 3-month prospective study.
Practical Urology Club].
AB - OBJECTIVES: To quantify the complications of TUR of prostate occurring during the
first three post-operative months. PATIENTS AND METHODS: Multicentric cooperative
study where skilled urologists, aged between 45 and 55 years old, with various
practice settings, compile complications in their consecutive patients undergoing
TURP between March and June 1996. 410 patients have been assessed by 17
urologists. RESULTS: Rate of intraoperative complications is low with 10 patients
being transfused and 3 TUR syndromes being observed. Two deaths occurred in
patients aged 84 and 92 years-old at post-op day 27 and 30 respectively. Twenty
four percent of patients experienced at least one complication during the
observation period, the most frequent of which was asymptomatic bacteriuria in
8.5%. Urethral--mainly meatal--stenosis was the main cause for the
readmission/reintervention rate (6.5%). CONCLUSION: Early morbidity/mortality of
TURP for BPH albeit real, occurs in a small percentage of patients, with a
general mild intensity. Alongside with excellent objective and subjective
outcome, these rates allow TUR of prostate to remain the gold-standard treatment
for BPH.
PMID- 10785919
TI - [Innervation of Denonvilliers' recto-vesical fascia. Anatomical study].
AB - OBJECTIVE: Dissection of Denonvilliers' rectovesical fascia allows easy cleavage
of the prostatorectal and prostatovesical spaces. Its lateral limit in the
"neurovascular pedicles" justifies its resection during radical prostatectomy.
The objective of this study was to define the course and to observe the structure
of nerves crossing the rectovesical fascia, as the sheaths of these nerves may be
invaded by prostatic adenocarcinoma tumour cells. MATERIAL AND METHODS: After
dissection of a fresh cadavre to define the relations of this fascia with the
pedicles, rectovesical fascia biopsies were taken during radical prostatectomies.
Transverse sections were performed and examined histologically. RESULTS: Certain
nerves, derived from the neurovascular pedicle of the inferior hypogastric
plexus, cross the rectovesical fascia to innervate the prostate. CONCLUSION: This
confirms the importance of complete resection of the rectovesical fascia during
radical prostatectomy for cancer, not only for surgical reasons, but also to
ensure oncologically satisfactory surgery, i.e. with healthy resection margins.
PMID- 10785920
TI - [Surgical treatment of traumatic ruptures of the posterior urethra].
AB - OBJECTIVES: To compare the therapeutic results of deferred urgent surgical
treatment and late treatment of traumatic ruptures of the posterior urethra.
MATERIAL AND METHOD: 35 patients with a mean age of 25 years (range: 7 to 79
years) were operated for trauma of the posterior urethra. In most cases, trauma
was secondary to a road accident, associated with fracture of the pelvis. When
rupture of the posterior urethra was diagnosed, the subsequent management
depended on the patient's general condition and associated lesions. In the
absence of serious skeletal or visceral lesions, the patient was operated within
3 weeks following trauma, after radiological assessment. This approach was
applied in 16 patients (Group I). The other 19 patients (Group II) were only
operated at the sixth month, after stabilization of all traumatic lesions.
RESULTS: Results were assessed in terms of the quality of the urinary stream,
urinary continence and sexual impotence. The stream was considered to be good in
93.75% of cases (Group I) and 78.8% of cases (Group II). Continence was perfect
in 100% of cases (Group I), versus 89.4% (Group II) and sexual impotence was
observed in 18.7% (Group I) versus 5.3% (Group II). CONCLUSION: Trauma of the
posterior urethra, without any serious associated lesions, can be operated as a
deferred emergency with excellent results in terms of voiding (80% of good
results), but with a higher frequency of sexual impotence. In patients with
serious associated lesions, the therapeutic management of the urethral trauma is
performed after an interval of 3 to 6 months, at the stage of urethral stricture.
In this case, surgery consists of resection of the fibrous callus, followed by
urethral anastomosis. The results of this operation are good, at the cost of
repeated stricture, treated endoscopically, but with a lower incidence of sexual
impotence.
PMID- 10785921
TI - [Extra-corporeal lithotripsy in the treatment of Peyronie's disease. Use of a
standard lithotriptor (Multiline Siemens) on "young" (less then 6 months old)
plaques].
AB - OBJECTIVE: The treatment of La Peyronie disease is still controversial. ESWL has
been recently proposed to treat symptomatic plaques. The results, although
discordant and often based on subjective assessment criteria, appear to show a
certain degree of efficacy on so-called young plaques, i.e. during the acute
phase of the disease. This study was designed to evaluate the results obtained
with a classical lithotriptor (Siemens Multiline) on plaques present for less
than 6 months. MATERIAL AND METHOD: 26 patients were included in this prospective
study. All presented a painful plaque on erection. The plaque was palpated under
general anaesthesia and 0.5 to 2 ml of contrast agent were injected to allow
radiological visualization. All patients received 3000 impacts at a power of 7
kilojoules in 1 session and all were reviewed 1 month and 3 months after the ESWL
session. RESULTS: Treatment was perfectly tolerated. Among the 26 patients
treated: 19 patients (73%) reported a very marked reduction of pain on erection
and 8 (31%) reported a reduction of curvature on erection, but this reduction was
demonstrated objectively (by tracing or photographs) for only 3 patients (11%).
Seven patients (27%) experienced softening of the plaque. Six (37%) of the
patients suffering from erectile dysfunction reported improvement of the quality
of erection, as reflected by the HEF score. CONCLUSION: A standard lithotriptor
can be used to treat La Peyronie plaques. ESWL appears to have a marked analgesic
effect, but its efficacy on correction of curvature of the penis was not
demonstrated in this study.
PMID- 10785922
TI - [Penile cancer: flow cytometry study of ploidies in 90 patients].
AB - OBJECTIVE: To evaluate prospectively 90 consecutive cases of squamous cell
carcinoma of penis, referred to our Institute, by flow cytometry analysis of
cellular DNA content. To compare deoxyribonucleic acid (DNA) flow cytometry with
clinical and pathological variables to determine the prognostic significance of
this analysis to guide the selection of patients at high risk for development of
lymph node metastases. PATIENTS AND METHODS: We determined the nuclear DNA of
tissues in fresh biopsy specimens of 80 patients diagnosed histologically as
invasive squamous cell penile carcinoma and in fresh biopsy specimens of 10
patients with verrucous carcinoma of penis. Samples were analyzed with a FACScan
flow cytometer, equipped with a doublet discrimination module, using the CellFIT
software package for data acquisition and analysis. RESULTS: The DNA pattern was
diploid in all samples excised from patients with verrucous carcinoma. According
to histological type the frequency of aneuploidy was 5.5% (1 of 18) in well
differentiated carcinoma, 28.8% (17 of 59) in moderately differentiated carcinoma
and 66.6% (2 of 3) in poorly differentiated carcinoma. CONCLUSION: The frequency
of DNA aneuploidy showed correlation with histological type of invasive squamous
cell carcinoma of the penis. Preliminary analysis suggests that patients with
high DNA index may be at increased risk of metastatic involvement.
PMID- 10785923
TI - [Role of systematic scrotal ultrasonography in the management of male
infertility: prospective study of 609 cases].
AB - OBJECTIVES: To assess the benefit and diagnostic contribution of systematic
scrotal ultrasound in the management of infertile men. MATERIAL AND METHODS:
Between 1st January and 31st December 1997, the authors conducted a consecutive
and prospective study of 609 infertile patients corresponding to 418 cases of
oligoasthenoteratospermia and 191 cases of azoospermia. All patients were
investigated by scrotal ultrasound. RESULTS: 133 patients (21.8%) did not present
any clinical or ultrasound abnormality. 60 patients (9.9%) presented isolated
clinical abnormalities and 125 patients (20.5%) presented a discordance between
clinical findings and ultrasound results. 9 patients (1.5%) presented an
ultrasound nodule, 6 of which were discovered incidentally. 22 patients (3.6%) in
whom the clinical features were more difficult to interpret, presented
unambiguous findings. CONCLUSION: Scrotal ultrasound makes a considerable
contribution to more appropriate management of infertile men and diagnoses 1.5%
of testicular tumours.
PMID- 10785924
TI - [Uretero-vaginal fistula. Therapeutic alternatives concerning 10 cases].
AB - OBJECTIVE: Our purpose was to study aetiopathogenic, diagnostic and therapeutic
aspects of ureterovaginal fistulas. STUDY DESIGN: A retrospective study concerned
10 ureterovaginal fistulas. The main causes were gyneacoligical and obstetrical
procedures. The diagnosis was based on clinical considerations and intravenous
pyelography in all cases. Various therapeutic methods were used: Fistulas has
managed in three cases by ureteroneocystostomy. Five cases were managed with
ipsilateral ureteroureterostomy, the segment of ureter below the fistula was
identified using ureteroscopic perforation of this segment in three cases. In one
case the fistula was successfully managed by ureteroscopic placement of ureteral
stent. In case whose fistula was developed after cancer pelvic we choice
abstention. RESULTS: Late radiology showed success of the procedure in 7 patients
and persistance of hypotony in 2 cases treated by u reteroneocystostomy.
CONCLUSION: Ureterofistula is rare, but a relative frequent complication of
pelvic surgery whose prevention is the most efficient treatment.
Ureteroureterostomy is a good procedure when ureteroscopy is performed.
PMID- 10785925
TI - [Emphysematous pyelonephritis in lithiasic kidney caused by acinetobacter].
AB - Emphysematous pyelonephritis is rare. It is exceptionally associated with
urolithiasis with obstruction of the collecting system. It is generally observed
in female diabetic patients. It is caused by gas-producing bacteria. We report a
case in which emphysematous pyelonephritis was caused by an acinetobacter,
associated with pelvic ureteral junction lithiasis. Drainage and nephrectomy were
necessary to overcome this life threatening situation.
PMID- 10785926
TI - [Value of cloverleaf double J ureteral stents in the treatment of extrinsic
ureteral compression].
AB - The authors report three cases of extrinsic bilateral ureteric stenoses in which
standard double J ureteric stents did not allow medium-term improvement of renal
function or resolution of pyelocaliceal cavity dilatation on ultrasonography. A
favourable course was observed after insertion of cloverleaf double J ureteric
stents.
PMID- 10785927
TI - [Bladder pheochromocytoma].
AB - OBJECTIVE: Report of a new case of a rare bladder tumour: bladder
phaeochromocytoma. MATERIAL AND METHODS: A 45-year-old patient presented with
paroxysmal symptoms consisting of headaches, palpitations, tinnitus and excessive
sweating after each micturition. Complementary investigations: ultrasonography,
intravenous urography and magnetic resonance imaging, suggested a circumscribed
tumour with a 2 cm long axis in the bladder dome, and the diagnosis of bladder
phaeochromocytoma was proposed. Partial cystectomy was performed. RESULTS: The
postoperative course was uneventful and the subsequent outcome was favourable
with resolution of all symptoms with a follow-up of 28 months. Histological
examination of the operative specimen confirmed the diagnosis of bladder
phaeochromocytoma. CONCLUSION: Bladder phaeochromocytoma is a rare tumour.
Treatment of this lesion requires the same preparation as for any other site of
phaeochromocytoma. Partial cystectomy ensures radical and effective treatment.
Long-term surveillance is necessary, as recurrences or metastases have been
described 20 and 40 years after treatment.
PMID- 10785928
TI - [Epididymal gaseous abscess after BCG treatment].
AB - The authors report a case of unilateral epididymitis with caseous abscess after
BCG-therapy for superficial bladder tumour. The severity of the lesions required
orchidectomy, followed by four-agent tuberculostatic therapy.
PMID- 10785929
TI - [Malignant penile melanoma].
AB - The authors report the case of a very large, obstructive malignant melanoma (MM.)
of the prepuce, encasing all of the distal extremity of the penis, and discovered
at a late metastatic stage (regional lymph node metastasis). Palliative
treatment, consisting of partial penectomy associated with a complementary
induction and maintenance chemotherapy did not achieve any objective response at
one year. MM. of the penis are rare urological tumours, including MM of the penis
and MM of the male urethra (exclusively mucosal involvement). The diagnosis of MM
of the penis must be considered in any case of black or brown lesion of the
glans, which is the most frequent site. The prognosis is determined by the
clinical stage (BRACKEN and DIOKNO classification) and by the depth and level of
tumour invasion (BRESLOW index and CLARK's degree of dermal invasion). The 5-year
survival is inversely proportional to the tumour thickness. The treatment of MM
of the penis is surgical; the extent of resection and the indication for lymph
node dissection depend on the patient's age, sexuality, and the stage of the
disease and depth of tumour invasion.
PMID- 10785930
TI - [Impact of genital prolapse on the upper urinary tract].
AB - The authors reviewed five cases of genital prolapse affecting the upper urinary
tract and causing renal failure. CLINICAL CASES: Five patients aged 55 to 75
years presented with genital prolapse, which was known by the patient in 3 cases
for a period of 2 to 30 year, but left untreated. All cases had induced bilateral
dilatation of the uretero-pyelocaliceal cavities with severe obstructive renal
failure in 3 cases, moderate renal failure in 2 cases and associated with
hypertension in 2 cases. Repair of prolapse, preceded by upper urinary tract
diversion by ureteric and bladder catheters in 3 cases or pessary + bladder
catheter because of the patient's age in 2 cases, cured or improved renal failure
in 4 patients; only one patient had to be treated by dialysis because of the
severity of the residual renal failure severity. DISCUSSION: The frequency (4%)
of aetiopathogenic mechanisms (ureteric compression, progressive stretching of
the ureter and posterior tilting of the trigone) are analysed. The delayed onset
of sudden deterioration and the varying degrees of severity of renal failure
demand emergency treatment of stage III prolapse with primary diversion of the
upper urinary tract, currently by double J stents, until correction or
improvement of renal function, after which surgical repair of the prolapse can be
performed according to the usual surgical rules. Intravenous urography is still
indicated in this situation. Palliative treatment is only indicated in elderly
patients or patients with a high operative risk. The best treatment remains
prevention by detection and treatment of prolapse before the development of this
fortunately rare complication. CONCLUSION: This short clinical series emphasizes
that undiagnosed prolapse can still be complicated by repercussions on the upper
urinary tract with a risk of renal failure.
PMID- 10785931
TI - [Dyschezia, pudendal neuropathy, and functional pelvico-perineal disorders].
AB - A critical literature review allows an analysis on chronic constipation
evaluation and on the association with anatomical or functional pelvic perineal
disorders, the link with a pudendal neuropathy being frequent. The dyschezia
clinical diagnosis must be completed by X-ray and manometric examinations to well
determine the respective part of anatomical and/or functional disturbances.
Stretch pudendal neuropathy was first described in association with descending
perineum and chronic constipation. This kind of neuropathy is frequently obvious
in other pelvic defects, genital prolapses, urinary incontinence, micturition
disturbances. The diagnosis must be made with a complete electrophysiological
assessment and not only with the pudendal nerve latency terminal motor latency
measurement. These pelvic-perineal disorders have plurifactorial aetiologies,
they are linked together without univoqual chronology, each one may be the cause
or the consequence of the other, and self-worsening evolution may occur.
PMID- 10785932
TI - [Opportunity for a systematic screening of prostatic cancer by determining
prostate specific antigen levels].
PMID- 10785933
TI - [Therapeutic management of epidermoid carcinoma of the penis: anatomoclinical
discussion and review of the literature].
AB - The therapeutic management of penile tumours is determined by the degree of local
extension of the tumour, and the presence of lymph node involvement and visceral
metastases. Many published studies have tried to define the best treatment
options as a function of tumour grade and stage. However, in daily practice, the
treatment of penile tumours still remains highly controversial. After reviewing
the literature, the authors discuss the various treatment options available to
urologists as a function of tumour stage and recall the management difficulties
related to lymph node staging.
PMID- 10785935
TI - [Napoleon III's urogenital disease (1808-1873)].
AB - We tried through this paper to reconstitute the evolution of the urologic illness
of Napoleon III, last emperor of France, the first symptoms of which appeared
many years before the fatal war of 1870, which led to the dismembering of France.
In this connection, we present Napoleon III's physicians and his cures, along
with the diagnostic and therapeutic errors. The case of Napoleon III is a typical
example of the influence the bad health of a sovereign can exercise on the
destiny of his country.
PMID- 10785934
TI - [Conservative surgical techniques in the treatment of kidney tumors].
AB - Several conservative operations are available for renal tumours. This article
describes the anatomical bases, the measures designed to protect the parenchyma
from ischaemia and the various resection techniques. Wedge resection is described
in detail, as it appears to be the most rigorous technique.
PMID- 10785937
TI - [Influence of culture conditions on ligninolytic activity of Stereum hirsutum].
AB - Stereum hirsutum BAFC 2234 was tested for growth kinetics and ligninolytic enzyme
production. The strain showed weak coincidences with widely studied organisms
(Phanerochaete chrysosporium, Pleurotus ostreatus) when the response to nitrogen
sources was assayed. This could be interpreted as a different regulation to
nitrogen metabolism for S. hirsutum BAFC 2234. Alternative carbon sources and the
addition of veratryl alcohol and wood extracts were also tested showing partial
correspondence with other ligninolytic fungi. On the basis of the high enzymatic
activities observed, S. hirsutum BAFC 2234 could be a suitable source of lignin
degrading system aiming techological processes.
PMID- 10785936
TI - [Identification and typing of yeast isolates from hospital patients in Mexico
City].
AB - Nosocomial yeast infections have become a major cause of morbidity and mortality
in immunocompromised patients. This study presents the frequency of yeasts
isolated from different biological products from a Mexico City hospital's
patients during one year. C. albicans was isolated in 72.3% of patients, followed
by C. glabrata (13.4%) and C. parapsilosis (8%). Twenty different morphotypes
were identified and the serotype B was the most frequent (79%).
PMID- 10785938
TI - [Comparison between the standard MPN method recommended by the American Public
Health Association and the Simplate and Petrifilm methods for identification of
the coliform group and Escherichia coli in tilapia (Oreochromis sp) originating
from aquaculture in fresh water].
AB - We have compared three methods for the detection and quantification of coliforms
and E. coli in fish: the conventional three-tube MNP method (APHA), the Simplate
Method and the Petrifilm Method. Thirty samples of the tilapia's external surface
(skin, gills and fin) produced in an artificial pond were collected. Samples were
processed individually in buffered peptone water 1%, then they were diluted and
inoculated in Simplate, Petrifilm and LST tubes. Coliforms were isolated from
100% of the samples. The Simplate and 3M Petrifilm results were obtained after 24
h of incubation. The conventional three-tube MNP method showed results only after
96 hours of incubation. Simplate showed better recovery of coliforms and E. coli
than 3 M Petrifilm and APHA method (P < 0.05). 3M Petrifilm and APHA were not
significantly different for E. coli recovery.
PMID- 10785939
TI - [Rapid diagnosis of principal respiratory viruses in the city of Havana, 1995
97].
AB - Acute respiratory diseases (ARD) are the most common infections in humans and
difficult to prevent. Viruses have been recognized as predominant ethiological
agents. In Cuba, ARD constitute a major problem of health and are the first cause
of morbidity and important cause of mortality. In this paper, rapid diagnosis was
performed to 516 clinical samples which arrived to the Reference Respiratory
Viruses Laboratory of the Pedro Kouri Institute of Tropical Medicine (IPK) from
different parts of Havana City during 1995, 1996 and 1997. The results obtained
have shown 218 positive samples (Influenza A, 89; respiratory syncytial virus 52;
Influenza B, 45; Adenovirus, 13; human parainfluenza virus(HPIV)-1, 6; HPIV-2, 3
and HPIV-3, 10). Influenza A was the virus most frequently found in adults,
whereas in closed population of teen-agers and adults, Influenza B was frequently
found. Furthermore, respiratory syncytial virus was the most important pathogen
in children's under 1 year of age.
PMID- 10785940
TI - [Contamination of bovine fetal serum with bovine viral diarrhea virus].
AB - Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses,
among them bovine viral diarrhea virus (BVDV) affecting the production of
biological reagents and the results of diagnosis. The filtration process used in
the preparation of commercial FBS abrogates most viral agents that may be present
in raw FBS, but BVDV may pass through the filters because of its small size and
its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3
(PI-3) is determined by observation of the cytopathic effect, and also by
hemadsorption in the case of PI-3, the most frequently isolated BVDV is non
cytopathic, and infects cells without morphological alterations, inducing
problems that arise after several cell generations. Batches of raw and processed
FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were
similar to those published for USA. By conventional methods for BVDV detection,
only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained
with high concentrations of the serum under study for at least 2 weeks, with
detection of viral antigen by indirect immunofluorescence, the percentage of BVDV
detection was 80%. This method shows that most lots of commercial FBS contain
BVDV. RT-PCR allows faster detection of the viral genome, but it must be
validated, as it does not show viral replication. To eliminate the problem of
BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.
PMID- 10785942
TI - [Indirect ELISA for the rapid diagnosis of Equine Influenza].
AB - An indirect enzyme linked immunosorbent assay was developed. Infected and non
infected allantoic fluids precipitated with polyetilenglycol 6000 were used as
antigen and control antigen, respectively. Serum samples were diluted 1/20 and a
commercial horse radish peroxidase-labelled rabbit anti-equine IgG was used as
second antibody. The reaction was developed using azino-diethylbenzotyazol
sulfonate (ABTS). Cut-off was determined by ratio sample (Rs). The
hemagglutination inhibition test was used as a reference test for the 391 samples
analyzed. Of these, 301 sera were positive by hemagglutination inhibition test
and indirect ELISA, 75 were negative by both techniques, and 15 were positive by
indirect ELISA and negative by hemagglutination inhibition test. Using
hemagglutination inhibition test as standard, the indirect ELISA showed a
relative specificity and sensitivity of 83.3 and 100%, respectively. This
indirect ELISA is useful as screening test.
PMID- 10785941
TI - Human immunodeficiency virus bDNA assay for pediatric cases.
AB - Techniques to quantify plasma HIV-1 RNA viral load (VL) are commercially
available, and they are adequate for monitoring adults infected by HIV and
treated with antiretroviral drugs. Little experience on HIV VL has been reported
in pediatric cases. In Argentina, the evaluation of several assays for VL in
pediatrics are now being considered. To evaluate the pediatric protocol for bDNA
assay in HIV-infected children, 25 samples from HIV-infected children (according
to CDC criteria for pediatric AIDS) were analyzed by using Quantiplex HIV RNA 2.0
Assay (Chiron Corporation) following the manufacturer's recommendations in a
protocol that uses 50 microliters of patient's plasma (sensitivity: 10,000
copies/ml). When HIV-RNA was not detected, samples were run with the 1 ml
standard bDNA protocol (sensitivity: 500 HIV-RNA c/ml). Nine samples belonged to
infants under 12 months of age (group A) and 16 were over 12 months (group B).
All infants under one year of age had high HIV-RNA copies in plasma. VL ranged
from 30,800 to 2,560,000 RNA copies/ml (median = 362,000 c/ml) for group A and <
10,000 to 554,600 c/ml (median = < 10,000) for group B. Only 25% of children in
group B had detectable HIV-RNA. By using the standard test of quantification,
none of the patients had non detectable HIV-RNA, ranging between 950 and 226,200
c/ml for group B (median = 23,300 RNA c/ml). The suggested pediatric protocol
could be useful in children under 12 months of age, but 1 ml standard protocol
must be used for older children. Samples with undetectable results from children
under one year of age should be repeated using the standard protocol.
PMID- 10785943
TI - [Evaluation of the reincubation of positive blood cultures for detection in the
BACT-ALERT system for the detection of polymicrobial bacteremia].
AB - Between February and September 1997, 6588 blood cultures at the Instituto de
Cardiologia y Cirugia Cardiovascular and Hospital de Ninos Ricardo Gutierrez were
studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294
episodes of bacteremia (600 samples) were analyzed. From these samples, 280
(95.3%) were monomicrobial episodes and 14 (4.7%) polymicrobial episodes.
Positive blood cultures detected by the Bact-Alert system were processed and then
reincubated during 7 days, when they were Gram stained and subcultured in blood
agar, chocolate agar (both in 5-10% CO2), laked blood agar supplemented with
hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE
(aerobic conditions). Following reincubation, 3 out of 14 polymicrobial
bacteremias were detected, rising the level of detection from 3.7% to 4.7%.
Taking into account the total number of bacteremias, only in 3 out of 294 (1%), a
second microorganism was detected. Otherwise, in blood cultures where a
contaminating microorganism was initially isolated, no further isolates
representing a true bacteremia were recovered. Reincubation and terminal
subculture of initially positive blood cultures did not provide relevant data in
order to change therapeutic measures in the studied population. Due to the
increase in costs and labor we consider that this methodology is not routinely
advised.
PMID- 10785944
TI - [Investigation of LIsteria monocytogenes in soft cheeses].
AB - Listeria monocytogenes has been recognized as a bacteria that produces severe
illness in animals and humans. Considering the importance of the presence of L.
monocytogenes in soft paste cheeses, a study of diverse cheeses from supermarkets
of direct sale to the public was carried out. From the 35 analyzed cheeses, 4
strains were isolated (11.4%). The result of the serological study showed that
all the strains corresponded to the serotype 4. The proteic profiles of the
isolated strains showed similarity with the used pattern (4b). Several authors
reported the importance of L. monocytogenes as contaminant in foods ready to eat
like the soft paste cheeses. Thus, it must be remarked the importance of the good
handling practices in the production, transport, refrigeration and exhibition of
this product.
PMID- 10785945
TI - [The Catholic church and abortion].
PMID- 10785946
TI - [Current management of thromboembolism in pregnancy and puerperium].
AB - Venous thromboembolism (VTE) remains the leading cause of maternal death. Today,
various risk factors and conditions are known to increase the risk for VTE
associated with pregnancy. Having identified the individual risk of a pregnant
women, appropriate preventive measures can be taken. If VTE occurs during
pregnancy, an appropriate immediate diagnostic work-up is essential in order to
avoid further complications. For deep vein thrombosis (DVT) the diagnostic tool
of choice is color-coded duplex-sonography, for pulmonary embolism (PE)
perfusion/ventilation lung scan can be used. Integrating a detailed individual
and family history, the presence of thrombophilia or other risk factors, a risk
stratification can be undertaken. These risk categories are defined in the
present paper and the appropriate treatment measures are described. As oral
anticoagulants cross the placenta and may cause embryopathy in any trimester,
oral anticoagulants should be avoided throughout pregnancy. Therefore, heparin is
the anti-coagulant of choice for pregnant women, with low molecular weight
heparins (LMWH) having distinctive pharmacological advantages over unfractionated
heparins. Besides a potential for bleeding, the main side effects of heparin
include heparin-induced thrombocytopenia which prompts for platelet monitoring,
especially in the first weeks of heparin treatment, and, secondly, heparin
induced osteoporosis, which is a potential sequel of long-term heparin
administration. Even though there are abundant reports in the literature on the
use of LMWH in pregnant women, that show that they are safe and effective, LMWH
are not specifically licensed for the use in pregnancy.
PMID- 10785947
TI - [Non-contraceptive benefits of the pill--an often neglected fact].
AB - While rare cardiovascular risks of oral contraceptives (OCs) caused a lot of
concern among OC-using women in the recent past, little attention has been paid
in the public to the non-contraceptive benefits of OCs. Short, medium and long
term non-contraceptive benefits have to be considered. The early Anglo-American
cohort and case-control studies demonstrated a reduction of menstrual complaints,
iron-deficiency anaemia, ectopic pregnancies, and a partly drastic reduction of
some benign and malignant tumours such as endometrial and ovarian cancer. A risk
reduction of rheumatoid arthritis is discussed controversially. The present paper
gives an overview of the state of knowledge. For newer OCs with different
composition, comparable studies are lacking. Therefore, a cohort study was
initiated in Germany in April 1998 to investigate these associations as well for
newer OCs, which is presented. The described non-contraceptive benefits should be
considered in the benefit-risk assessment when prescribing OCs.
PMID- 10785948
TI - [Effects of tubal sterilization].
AB - OBJECTIVE: Besides manifestations of hormonal deficits, psychological problems
are also known as possible negative effects of tubal sterilization (here termed
"operative contraception"--OC). It is generally assumed that the age at time of
operation and the number of children play a crucial role in enabling the patient
to come to terms with surgical contraception. We investigated whether these
patients were satisfied and the frequency of a desire for refertilization as well
as further factors possibly affecting our patients. PATIENTS AND METHODS: A
standardized questionnaire was sent to 274 women in whom surgical contraception
was performed from 1984 to 1990 in our hospital. Besides physical symptoms, the
questions mainly inquired as to satisfaction, degree of regret and desire for
refertilization. RESULTS: 5.4% of women were not satisfied with the operation.
13.7% of the patients regretted the operative contraception and 6.5% wished to
have refertilization. The negative appraisal did not correlate with the number of
children and age at the time of operative contraception. Altogether, satisfaction
was very much greater in patients who had completed family planning than in
patients who had received operative contraception for medical reasons. Appraisal
of operative contraception was especially negative in women in whom the operation
had been performed on the occasion of a cesarean section. CONCLUSION: Our follow
up investigation confirmed that operative contraception was experienced as being
very liberating by most women and was accordingly appraised positively on the
whole. The number of children and age only played a subordinate role in how
patients came to terms with their situation. For a positive experience of
operative contraception, the time of the operation appears to be of major
importance. In particular, "favorable opportunities" on the occasion of cesarean
section and the if anything doubtful need for this measure in the condition after
prior cesarean sections must be avoided, since in these cases a free decision in
favor of operative contraception, which the woman concerned feels to be
autonomous, is not possible.
PMID- 10785949
TI - [LEEP versus cold knife conization for treatment of cervical intraepithelial
neoplasias].
AB - OBJECTIVE: This study was performed to evaluate the effectiveness and side
effects of loop electrosurgical excision procedure (LEEP) in comparison to cold
knife conization for the treatment of cervical intraepithelial neoplasia (CIN).
MATERIAL AND METHODS: Between January 1996 and July 1998, 177 patients underwent
conization. In a matched-pair setting, 50 cases with LEEP were compared with 100
classical conization cases. LEEP was performed with ectocervical and endocervical
excision. RESULTS: Perioperative complications were less in the LEEP group (6%
vs. 11%). The mean volume of LEEP specimens (1.6 cm3) was significantly smaller
than the volume of cone specimens (2.6 cm3). Thermal artifacts were negligible.
There were no significant differences in the proportion of margin involvement
(20% vs. 19%) and residual/recurrent CIN. The endocervical excision contained
dysplastic tissue in 38% of the cases; more important, a positive endocervical
excision was found in 14/21 CIN 3 cases (67%). The success rate, was similar in
both groups (96% vs. 97%). Hospitalization time was less for the LEEP group.
CONCLUSIONS: LEEP conization is a safe and cost effective procedure with a lower
complication rate providing a significantly smaller specimen compared to cold
knife conization. Therefore, LEEP conization may substitute cold knife
conization. However, we do recommend to perform LEEP conization with an
endocervical excision to reduce residual CIN.
PMID- 10785950
TI - [Galactography: important preoperative method for breast surgery].
AB - Galctography still is a very important method in the diagnosis of breast disease.
We studied the influence of indication on the diagnostic and therapeutic efficacy
of galactography. Between 1990 and 1998 210 galactographies performed in a
standardized fashion were evaluated in relation to the histopathologic findings.
Most of the pathology was caused by papilloma followed by ectatic ducts and
carcinoma. There was also a large number of normal ducts. In patients that were
operated on, there was a very high percentage of agreement between radiological
and histopathological diagnosis. If indication and performance are precise,
galactography yields very good results and thus contributes substantially to the
surgical approach. In particular it guides the surgeon safely to the pathologic
finding and thus guarantees its excision within a small volume of tissue.
PMID- 10785951
TI - [Thrombosis of ovarian veins in puerperium associated with heparin-induced
thrombocytopenia type II].
AB - We report for the first time on a puerperal ovarian vein thrombophlebitis
associated with heparin-induced thrombocytopenia type II. Two weeks after
cesarean section with subsequent prophylactic application of heparin a thrombosis
in the left deep femoral and pelvic veins and in the right ovarian vein occurred.
Despite only moderately reduced platelet count a heparin-induced thrombocytopenia
type II was diagnosed by heparin-induced platelet activation test. By treatment
with plasmin activator lysis the thrombus was diminished. An operative procedure
had been prevented. We conclude that also in cases with only moderately reduced
platelet count during and after administration of heparin, especially in patients
with wide spread and accumulating thrombosis, the presence of a heparin-induced
thrombocytopenia should be taken into consideration. In contrast to difficulties
in the management of puerperal ovarian vein thrombophlebitis--occurring
independently from heparin-induced thrombocytopenia (surgical treatment necessary
in most cases)--occurrence of puerperal ovarian vein thrombophlebitis in relation
to heparin-induced thrombocytopenia seems to response better to fibrinolysis and
anticoagulation.
PMID- 10785952
TI - [Computer support of workflow in the hospital: concepts, technology and
application].
AB - For a variety of reasons, hospitals are developing a growing interest in changing
their information systems to support patient processes in a more direct way. This
means to actively deliver the tasks to be performed to the right persons at the
right point in time with the necessary information and the application functions
needed for performing these tasks. Process-oriented workflow technology is a very
interesting candidate to achieve this goal. It offers components for the computer
based analysis, modeling, animation, coordination and monitoring of (hospital)
processes. In this paper we discuss the perspectives offered by workflow-based,
clinical information systems. We survey key features of today's business process
modeling tools and of workflow management systems, and we show how they can be
applied in the clinical domain. To illustrate the huge potential offered by
workflow technology, we present results from the project "Using Workflow
Management Systems for Clinical Applications". Within this project we thoroughly
analyzed and redesigned core processes from the University's Women hospital and
we proto-typically implemented a workflow-based application system for the
support of processes from the division day clinic. Although our work shows that
current workflow technology is still lacking some important features, in the long
run, it may strongly influence information processing within hospitals.
PMID- 10785953
TI - [In memoriam Karl Gunther Ober (24.8.1915-27.2.1999)].
PMID- 10785954
TI - [The meeting of the Japanese Society of Anesthesiology as a bridge between the
20th century and the 21st anesthesiological science].
PMID- 10785955
TI - [Anesthesiology of 20th century and the future prospects in Japan].
PMID- 10785956
TI - [Procedures and the significance of Evidence-based Medicine].
PMID- 10785957
TI - [Role of transesophageal echocardiography in cardiovascular surgical procedures-
special reference to the importance of cooperation between anesthesiologists and
surgeons].
PMID- 10785958
TI - [Present status of infectious diseases transmitted by blood transfusion and the
preventive measures].
PMID- 10785959
TI - [Enlightenment and the propagation of autologous blood transfusion].
PMID- 10785960
TI - [Searching for new genes--Our experience of finding the genes related to nervous
system diseases].
PMID- 10785961
TI - [Anesthesia for dentistry in handicapped persons].
PMID- 10785962
TI - [Progress on physiopathological study of shock--Approach from the molecular
biological point of view].
PMID- 10785963
TI - [Quality of recovery from anesthesia].
PMID- 10785964
TI - [Active sites of anesthetics in the vascular systems].
PMID- 10785965
TI - [Effects of anesthetics on tracheal smooth muscle].
PMID- 10785966
TI - [Anesthesia and the pharynx].
PMID- 10785967
TI - [Various problems involved in diagnosis of brain death and decision of organ
harvesting].
PMID- 10785968
TI - [Mechanism of postoperative pain and the analgesia].
PMID- 10785969
TI - [Anesthesia for pediatric surgical emergencies].
PMID- 10785970
TI - [Preoperative evaluation of patients with cardiovascular disorders].
PMID- 10785971
TI - [Anesthesia for cesarean section--special reference to fetal oxygenation].
PMID- 10785972
TI - [Postoperative complications in aged patients].
PMID- 10785973
TI - [Anesthesia and the allergic reaction].
PMID- 10785974
TI - [Anesthesiological problems in thoracoscopy and laparoscopy].
PMID- 10785975
TI - [Applicability of intravenous anesthesia--special reference to propofol and
ketamine].
PMID- 10785976
TI - [Metabolism and toxicity of anesthetics].
PMID- 10785977
TI - [New methods of cardiopulmonary resuscitation].
PMID- 10785978
TI - [Intraoperative monitoring of the bain and spinal cord during anesthesia].
PMID- 10785979
TI - [Drug interactions among anesthetics].
PMID- 10785980
TI - [Cases with difficulty of intratracheal intubation].
PMID- 10785981
TI - [Intraoperative arrhythmia--the etiology, diagnosis, and the therapy].
PMID- 10785982
TI - [Selection of local anesthetics for clinical usage].
PMID- 10785983
TI - General practice care following miscarriage.
PMID- 10785985
TI - Investigation of lipids. What do the results really mean?
AB - BACKGROUND: The National Heart foundation recommends that all adult Australians
should have their plasma lipids measured to help assess their risk of
cardiovascular disease (CVD). Patients usually concentrate on their total
cholesterol result, but this is less informative than the levels of individual
lipoproteins, particularly low density lipoprotein (LDL) and high density
lipoprotein (HDL). OBJECTIVE: To discuss the considerations behind laboratory
lipid measurements and their interpretation. DISCUSSION: Adult patients are best
assessed with total cholesterol, triglyceride and HDL-C allowing calculation of
LDL-C. Treatment decisions should be based on LDL-C levels in the context of the
overall risk factor status of the patient for CVD. Additional laboratory tests
are available, some of which may assist with diagnosis or clinical decision
making.
PMID- 10785984
TI - Choosing the most appropriate therapy for lipid disorders.
AB - BACKGROUND: There is general acceptance of the need to treat hyperlipidaemia to
reduce the risk of coronary artery disease. However, the level at which it is
appropriate to introduce drug therapy varies with the cardiovascular risk of the
patient. As the range of medications available increases, choosing the
appropriate therapy for a patient becomes more difficult. OBJECTIVE: To provide
the practitioner with a clear view of lipid treatment goals and how to select the
most appropriate treatment. DISCUSSION: Diet is the cornerstone of treatment,
with a discretionary use of drugs when hyperlipidaemia persists, particularly in
those patients with unacceptably high cardiovascular risk. For a predominant
cholesterol problem statin drugs are first choice, whereas fibrate drugs are most
appropriate for hypertriglyceridaemia. For mixed hyperlipidaemia statin, fibrate
or combinations may be required. Treatment is effective and safe but compliance
with long term therapy remains a problem.
PMID- 10785986
TI - Issues in managing hyperlipidaemia.
AB - BACKGROUND: The relationship of plasma cholesterol to human coronary artery
disease was established with the Framingham study in 1960 and an elevated plasma
cholesterol is now considered the major modifiable risk factor for developing
coronary artery disease. Recent studies, including the Australian LIPID study,
have changed what we consider to be acceptable cholesterol levels. OBJECTIVE: To
discuss the role of serum cholesterol levels, dietary modification and lipid
lowering drug treatments in overall cardiovascular risk management. DISCUSSION:
The current challenges in lipid management are to find ways to increase adherence
to medication and deciding how far cholesterol should be lowered. Treatment of a
particular patient depends not just on their serum cholesterol but on their
overall cardiovascular risk. Diet has cardioprotective effects separate from
modification of serum cholesterol levels and this may be true of some lipid
lowering treatments.
PMID- 10785988
TI - Integrating counselling into general practice.
AB - BACKGROUND: General practice counselling has many significant differences to
counselling in other settings. General practitioners have long term relationships
with their patients involving physical as well as mental health care. General
practitioners are often the first point of contact for distressed patients who
may not perceive their problem to have a psychological basis. There are barriers
to counselling including time management and cultural expectations of the
consultation. OBJECTIVE: To outline a practical biopsychosocial model for
counselling in the general practice setting using the knowledge and skills unique
to each GP. Theoretical and practical barriers to counselling commonly
encountered in general practice are discussed. DISCUSSION: Assessing the problem
in a biopsychosocial format highlights strengths and skills the patient already
possesses and involves consideration of physical sensations, emotions,
behaviours, key relationships, family, social roles and resources. Counselling in
general practice requires flexibility and an ability to adapt available resources
to address patient needs in an individually appropriate way.
PMID- 10785987
TI - Treating elevated lipids. Does it make a difference?
AB - BACKGROUND: There is now abundant evidence from clinical trials that treatment
with lipid modifying therapy will decrease the risk of coronary heart disease
(CHD). The decision to treat a patient, whether with advice on lifestyle
modification or with drug therapy, needs to be based on consideration of costs
versus benefits. OBJECTIVE: To assess the evidence from primary and secondary
prevention studies for cardiovascular benefit of cholesterol lowering medication.
DISCUSSION: Treating hypercholesterolaemia reduces the relative risk of major CHD
events by about 30%. The greatest benefit of lipid lowering treatment is in the
high risk group. This group shows the greatest reduction in absolute risk and
therefore a 'smaller number to treat' to prevent one major CHD event. In the
moderate risk group three times as many individuals require treatment to prevent
one major CHD event. However, this corresponds to the benefit in primary
prevention of stroke by treating mild-moderate hypertension in middle aged men.
PMID- 10785989
TI - The Australian categorisation of risk of drug use in pregnancy.
PMID- 10785990
TI - Coronary artery trauma in chest wall injury.
AB - BACKGROUND: Blunt chest trauma is a rare but important cause of coronary artery
occlusion. Coronary damage may occur with even relatively minor chest injuries.
The diagnosis of cardiac injury can be difficult in the setting of chest wall
trauma as the usual findings of chest pain, cardiac enzyme assay and ECG are
unreliable diagnostic tools. OBJECTIVE: A case is presented demonstrating the
diagnosis difficulties. DISCUSSION: An ECG abnormality in the setting of even
minor chest injury requires assessment with echocardiography and, if abnormal,
angiography. Currently angiography is the definitive diagnostic test and allows
for therapeutic intervention as appropriate but coronary artery ultrasound may
find a place in management. Further management depends on the time of diagnosis
and the presence of other injuries.
PMID- 10785991
TI - Extreme anxiety/panic disorder.
AB - A 45 year old man is referred to a specialist psychiatric centre. For 3 years he
has been experiencing worsening impending fear of death and anxiety which he
describes as 'panic attacks'. During these episodes he often experiences
palpitations and becomes sweaty. These episodes have not been relieved despite
several courses of electroconvulsive therapy. On examination, the man is alert
and orientated. He has a normal blood pressure of 125/75 mmHg and
electrocardiogram reveals a pulse rate of 102 beats per minute. A psychiatrist
orders a number of routine tests to rule out organic disease.
PMID- 10785992
TI - A fever from the tropics.
AB - Shirley is a 42 year old woman who has rung you 5 days after returning from a 3
week resort holiday in Malaysia and Thailand. You saw her before her trip and
administered a hepatitis A vaccine and advised her that she did not require anti
malarial drugs as she was only going to large cities and beach resorts. She says
she has had a high fever, headache and body aches for several days and that she
feels exhausted, but is well enough to come to the surgery. When you see her
later that morning, she looks fairly well, although she is moving rather
gingerly. She says she has been resting, is drinking lots of fluids, has some
anorexia, but no other significant symptoms. Examination reveals a temperature of
38 degrees C and she has a fine morbilliform rash on her body, limbs and neck.
There are no other abnormal findings.
PMID- 10785993
TI - Things don't always change for the better.
PMID- 10785994
TI - The Australian practice nurse. Still more questions than answers.
PMID- 10785995
TI - The role of the practice nurse. An exploratory study.
AB - AIM: There is little research on the role of the practice nurse in Australia.
However, there is some evidence that practice nurses are no longer primarily
receptionists, but rather function as nurses. This article reports on a small
qualitative study that set out to identify areas of effective shared care between
general practitioners and practice nurses. METHOD: Semistructured interviews were
conducted with general practitioners and practice nurses in eight general
practices. A general practitioner who did not employ a practice nurse and a
general practitioner and two nurse practitioners at a Community Health Centre
were also interviewed. RESULTS: It was found that general practitioners and
practice nurses have established effective working relationships that enhance
patient care. Shared care was not found, except to some extent in the area of
wound care. CONCLUSION: Most GPs and practice nurses interviewed believed that
the current funding model, requiring GPs to sight all patients before a fee can
be claimed, restricts the potential use of practice nurses' expertise, for
example with patients returning for routine blood tests or blood pressure
monitoring, or wound dressing. A change to the current model would have
implications for the education and accreditation of practice nurses.
PMID- 10785996
TI - Reducing the incomplete excision of non melanotic skin cancers in Australian
general practice.
AB - AIM: To develop a simple set of predictors of incomplete excision of non
melanotic skin cancer and to test them prospectively. METHOD: Possible predictors
were identified by a literature review and modified by a retrospective analysis
of histologically confirmed excisions by the author between 1992 and early 1998.
The composite set was then tested prospectively on non melanotic skin cancer
excisions from April 1998 to September 1999. RESULTS: The set of predictors was
used prospectively to identify lesions with which particular care should be taken
to avoid incomplete excision. Using this method resulted in an overall reduction
of incomplete excisions of about 50%. CONCLUSIONS: The application of a set of
predictors is an effective method of reducing incomplete excisions. A number of
factors related to the age of the patient, the site of the lesion and its
macroscopic appearance made up the set of predictors. Their application showed
that particular care needs to be taken with lesions on the head and neck and
lesions on patients who are under 50 years of age.
PMID- 10785997
TI - The early detection of glaucoma in general practice.
AB - BACKGROUND: Glaucoma is one of the most common preventable causes of visual loss.
Because it is an asymptomatic condition until late in the process only 50% of the
population with glaucoma are aware they have it. Primary care physicians rarely
test their patients for glaucoma, primarily because of the lack of specificity or
sensitivity of any one particular test. OBJECTIVE: To determine if it was
possible to identify patients with early signs of glaucoma from within my own
practice, in patients who had not previously been tested for glaucoma or had not
been tested for at least two years. DISCUSSION: This study has shown that
glaucoma case-finding is feasible in general practice. Direct ophthalmoscopy
proved to be the most valuable single test in diagnosing glaucoma and the
combination of measurement of intraocular pressure and direct ophthalmoscopy was
shown to be the most likely method of diagnosing glaucoma or identifying glaucoma
suspects.
PMID- 10785998
TI - Calibration of sharp cut impactors for indoor and outdoor particle sampling.
AB - A low-flow rate, sharp cut point inertial impaction sampler was developed in 1986
that has been widely used in PM exposure studies in the United States and several
other countries. Although sold commercially as the MS&T Area Sampler, this
sampler is widely referred to as the Harvard Impactor, since the initial use was
at the Harvard School of Public Health. Impactor nozzles for this sampler have
been designed and characterized for flows of 4, 10, 20, and 23 L/min and cut
points of 1, 2, 5, and 10 microns. An improved method for determining the actual
collecting efficiency curve was developed and used for the recent impactor
calibrations reported here. It consists of placing a multiplet reduction impactor
inline just downstream of the vibrating orifice aerosol generator to remove the
multiplets, thus allowing only the singlet particle s to penetrate through to the
impactor being calibrated This paper documents the techniques and results of
recent nozzle calibrations for this sampler and compares it with other size
selective inertial impactors. In general, the impactors were found to have sharp
cutoff characteristics. Particle interstage losses for all of the impactors were
very low, with the exception of the 10-micron cut size 20 L/min impactor, which
had greater losses due to the higher flow rate. All of the 2.5-micron cut nozzle
laboratory calibrations compare favorably to the U.S. Environmental Protection
Agency (EPA) WINS-96 fine particle mass (PM2.5) impactor calibration data.
PMID- 10785999
TI - Effect of methyl tertiary butyl ether concentrations on exhaust emissions from
gasoline used in the metropolitan area of Mexico City.
AB - In this work, the primary objective was to assess the impact of oxygenated fuel
on the exhaust emissions from an important fraction of vehicles in the
Metropolitan Area of Mexico City (MAMC). The results aim to provide information
on the actual effect of MTBE on a fleet that represents more than 60% of the in
use vehicles in the MAMC. Ten vehicles were tested with a low-octane base
gasoline, and 10 more with a regular-grade unleaded base gasoline. Three MTBE
concentrations, 5, 10, and 15 vol %, were tested following the U.S. Federal Test
Procedure (FTP). CO, total HC, and NOx from the exhaust gases were quantitatively
evaluated and also characterized for FTP speciated organic emissions. From this
data, the O3-forming potential of the fuels was calculated. Results show that for
the fleet using low-octane gasoline, the addition of 10% MTBE substantially
reduced CO emissions, but total HC concentration in the exhaust showed a modest
decrease. For the regular gasoline, the 10% MTBE blend seemed to be the best
choice, but there was not a significant decrease in emissions. The specific
reactivity of each fuel, expressed in grams of O3 per gram of nonmethane organic
gases, increased with MTBE concentration in both cases. This result is important
to consider, especially for a region like Mexico City, which has high atmospheric
O3 concentrations.
PMID- 10786000
TI - Neural network model for predicting peak photochemical pollutant levels.
AB - In this paper, an attempt is made for the 24-hr prediction of photochemical
pollutant levels using a neural network model. For this purpose, a model is
developed that relates peak pollutant concentrations to meteorological and
emission variables and indexes. The analysis is based on measurements of O3 and
NO2 from the city of Athens. The meteorological variables are selected to cover
atmospheric processes that determine the fate of the airborne pollutants while
special care is taken to ensure the availability of the required input data from
routine observations or forecasts. The comparison between model predictions and
actual observations shows a good agreement. In addition, a series of sensitivity
tests is performed in order to evaluate the sensitivity of the model to the
uncertainty in meteorological variables. Model forecasts are generally rather
insensitive to small perturbations in most of the input meteorological data,
while they are relatively more sensitive in changes in wind speed and direction.
PMID- 10786001
TI - Biotrickling filtration of nitric oxide.
AB - A biotrickling filter with blast-furnace slag packings (sizes = 20-40 mm and
specific surface area = 120 m2/m3) was utilized to treat NO in an air stream. The
operational stability, as well as the effects of gas empty-bed retention time
(EBRT) and nutrient addition on the removal ability of NO, were tested.
Approximately six weeks were required for the development of a biofilm for NO
degradation, and a two-week organic carbon deficiency resulted in the detachment
of biofilms from the packing surfaces. A steady removal rate of 80% was attained
at specified influent NO concentrations of 892 to 1237 ppm and an EBRT of 118
sec. The effluent NO concentration diminished exponentially with enlarging EBRT,
with influent NO concentrations of 203-898 ppm, and EBRTs of 25 to 118 sec.
Nutrient addition is essential for efficient removal of the influent NO. Mass
ratios of C: P: N = 7: 1: 30 and NaHCO3: NO-N = 6.3 could be used for practical
applications.
PMID- 10786002
TI - Costs, emissions reductions, and vehicle repair: evidence from Arizona.
AB - The Arizona inspection and maintenance (I/M) program provides one of the first
opportunities to examine the costs and effectiveness of vehicle emission repair.
This paper examines various aspects of emission reductions, fuel economy
improvements, and repair costs, drawing data from over 80,000 vehicles that
failed the I/M test in Arizona between 1995 and the first half of 1996. We
summarize the wealth of data on repair from the Arizona program and highlight its
limitations. Because missing or incomplete cost information has been a serious
shortcoming for the evaluation of I/M programs, we develop a method for
estimating repair costs when they are not reported. We find surprising evidence
that almost one quarter of all vehicles that take the I/M test are never observed
to pass the test. Using a statistical analysis, we provide some information about
the differences between the vehicles that pass and those that do not. Older, more
polluting vehicles are much more likely never to pass the I/M test, and their
expected repair costs are much higher than those for newer cars. This paper
summarizes the evidence on costs and emission reductions in the Arizona program,
comparing costs and emissions reductions between cars and trucks. Finally, we
examine the potential for more cost-effective repair, first through an analysis
of tightening I/M cut points and then by calculating the cost savings of
achieving different emission reduction goals when the most cost-effective repairs
are made first.
PMID- 10786003
TI - Speciated hydrocarbon emissions from small utility engines.
AB - Partially speciated hydrocarbon (HC) emissions data from several small utility
engines, as measured by a Fourier Transform Infrared analyzer, are presented. The
engines considered have nominal horsepower ratings between 3.7 and 9.3 kW. Both
side-valve and overhead-valve engines are studied, and four different fuels are
used in the engines. The results indicate that the small HCs present in the
exhaust tend to be in the form of either methane or unsaturated HCs. Other small
alkanes, such as ethane and propane, are present in only relatively small
concentrations. In terms of ozone formation potential, the HCs in the form of
methane will lead to little ozone, but the distribution of the C2 and C3 species
is not ideal from an ozone reduction stand-point. It is also found that the
presence of oxygen in the fuels appears to lead to somewhat more complete
combustion, although the effects are not large. Finally, the overhead-valve
engines appear to have lower HC emissions than side-valve engines, which is
primarily due to higher operating A/F ratios and the engine geometry.
PMID- 10786004
TI - Microwave regeneration of activated carbon used for removal of solvents from
vented air.
AB - A microwave regeneration of activated carbon used to remove organic solvents from
vented air has been investigated. Methyl ethyl ketone (MEK), acetone, and
tetrachloroethylene (TCE) vapors were removed from vented air through adsorption
onto granular activated carbon. The saturated carbon was then regenerated in a
microwave field, where the solvent was quickly desorbed and recovered from the
inner pores of the carbon granules. The microwave-induced regeneration restored
the original adsorption capacity and surface area of the activated carbon.
PMID- 10786005
TI - Removal of chromium from abrasive blast media by leaching and electrochemical
precipitation.
AB - Water is effective in leaching out Cr6+ from a mixture of paint powders and
abrasive blast media. However, acids such as HNO3, HCl, and H2SO4 significantly
enhance the leaching procedure. Cr ions in the leaching solutions are
successfully removed by electrochemical precipitation. The consumable Fe
electrodes generate ferrous ions to cause the reduction of Cr6+ to Cr3+. Cr3+
ions along with Fe2+ and Fe3+ are then removed mainly by precipitation as
Cr(OH)3, Fe(OH)2, and Fe(OH)3 near the cathode where OH- ions are generated by
water electrolysis. The electrochemical process is capable of discharging low
levels of Cr6+, less than 1 mg/L, without pH adjustment.
PMID- 10786006
TI - On-road motor vehicle emissions and fuel consumption in urban driving conditions.
AB - This paper reports on the analysis of on-road vehicle speed, emission, and fuel
consumption data collected by four instrumented vehicles. Time-, distance-, and
fuel-based average fuel consumption, as well as CO, HC, NOx, and soot emission
factors, were derived. The influences of instantaneous vehicle speed on emissions
and fuel consumption were studied. It was found that the fuel-based emission
factors varied much less than the time- and distance-based emission factors as
instantaneous speed changed. The trends are similar to the results obtained from
laboratory tests. The low driving speed contributed to a significant portion of
the total emissions over a trip. Furthermore, the on-road data were analyzed
using the modal approach. The four standard driving modes are acceleration,
cruising, deceleration, and idling. It was found that the transient driving modes
(i.e., acceleration and deceleration) were more polluting than the steady-speed
driving modes (i.e., cruising and idling) in terms of g/km and g/sec. These
results indicated that the on-road emission measurement is feasible in deriving
vehicle emissions and fuel consumption factors in urban driving conditions.
PMID- 10786008
TI - Climate change and the adaptability of agriculture: a review.
AB - The assessment of climate change impacts on agriculture has emerged as a
recognizable field of research over the past 15 years or so. In a relatively
short period, this area of work has undergone a number of important conceptual
and methodological developments. Among many questions that have been debated are
the adaptability of agriculture to climate change and the importance of land
management adjustments in reducing the adverse effects of climate change. In
turn, this latter focus has spawned a discussion regarding the nature of
adaptation and the ability of agriculture to respond to sudden and rapid climatic
changes. In this paper we present an overview of this debate. It is argued that
the first generation of climate change impact studies generally ignored the
possibility that agriculturalists may adjust their farming practices in order to
cope with climate change or to take advantage of new production opportunities.
This conceptual oversight has been largely eliminated over the past five years or
so. However, questions remain surrounding the likelihood that various adaptive
strategies will actually be deployed in particular places. In this paper, we
stress the importance of studying adaptation in the context of decision-making at
the individual farm level and beyond.
PMID- 10786007
TI - A kinetic study on oxidation of pentachlorophenol by ozone.
AB - The kinetics of pentachlorophenol (PCP) ozonation in terms of the gaseous O3 and
dissolved PCP concentrations has been investigated. When the O3 concentration in
the gas phase was in the range of 10 to 40 g O3/m3, the O3 dissolved for a short
time period was proportional to the gaseous O3 concentration. In this range, the
ozonation reaction was first order for each reactant and the overall reaction was
second order. At 25 degrees C, in an aqueous solution, the reaction rate constant
was estimated to be 10.048 L/mol.sec. The reaction rate was much greater than the
mass-transfer rate, indicating that the reaction of O3 and PCP was an interface
reaction on the surface of gaseous O3 bubbles. The final product of the PCP
ozonation was oxalic acid, with the carbon yield of the reaction being 59.4%. The
ozonation of PCP in the aqueous solution was not a radical reaction but a direct
reaction between O3 and PCP molecules under the conditions investigated in this
study, since O3 has a high selectivity toward PCP. The reaction rate increased
with the reaction temperature up to 35 degrees C but decreased at temperatures
greater than 35 degrees C due to the decreased solubility of O3. The addition of
H2O2 did not increase the reaction rate significantly.
PMID- 10786009
TI - Evaluation of watering to control dust in high winds.
AB - A field study was conducted to determine the effectiveness of watering in
controlling PM10 emissions under high wind conditions. The focus of the study was
the pickup of soil by a belly scraper at a landfill. Four low-volume PM10
samplers were positioned downwind of the storage pile (at two distances, 80 and
110 m, and two elevations, 1 and 3 m) and one was located upwind at 3 m
elevation. Integrating nephelometers, which measure the particulate light
scattering coefficient, bsp, were also set up at locations 80 and 110 m downwind
of the storage pile. Wind speed and direction were measured on-site. Samples were
collected for two periods, one with and one without water being applied. Watering
was effective at reducing PM10 emissions at wind speeds up to the maximum 18 m
sec-1 observed at the landfill soil pickup operation. Measurement of bsp provided
an indication of PM10 concentrations with better time resolution than samplers,
but not with sufficient resolution, under the instrumental conditions used, to
correlate with wind gusts.
PMID- 10786010
TI - Performance characteristics of PM10 samplers under calm air conditions.
AB - The size range of airborne particles that is closely related to specific
deposition regions in the human respiratory tract and excess lung burden of these
deposited particles is associated with disease. Size-selective sampling,
therefore, needs to be performed to assess the related health risks. Performance
criteria applied to these samplers must be well characterized in order to provide
accurate and reliable results. The PM10 samplers that have been used in place of
the total suspended particulate samplers for the collection of ambient air
particles are more relevant to potential inhalation hazards. In order to be
certified, a PM10 sampler must meet reliable performance specifications,
primarily the aerosol penetration test with liquid and solid particles in a wind
tunnel (wind speeds of 2, 8, and 24 km/hr). This testing is intended to assure
reasonable accuracy in aerosol measurements. However, the sampler performance
under calm air conditions has not been well studied. In the present study, the
sampling heads of three devices--the Harvard impactor, the Personal Environmental
Monitor (PEM), and the Sierra Andersen model 241 dichotomous sampler PM10 inlet
head--were tested for aerosol separation efficiency. With the consideration of
bias and imprecision of the measurements, five specimens of each type of sampler
were chosen for performance testing, repeating the tests 5 times for each
specimen. An ultrasonic atomizing nozzle was used to nebulize potassium sodium
tartrate tetrahydrate and dioctyl phthalate particles as the solid and liquid
challenge aerosols, respectively. The aerosol number concentrations and size
distributions upstream and downstream of the samplers were measured by using an
aerosizer calibrated against a settling velocity chamber. The results showed that
among the samplers tested, the dichotomous sampler PM10 inlet head had the best
fit to the PM10 convention, while the other two samplers not only appeared to
have a steeper separation-curve slope but also had significant particle bounce
when challenged with solid particles. Analysis of variance also confirmed the
superiority of the dichotomous samplers. Surface-coating with oil or grease
greatly reduced the problem of particle bounce.
PMID- 10786011
TI - Guidance for the performance evaluation of three-dimensional air quality modeling
systems for particulate matter and visibility.
AB - Guidance for the performance evaluation of three-dimensional air quality modeling
systems for particulate matter and visibility is presented. Four levels are
considered: operational, diagnostic, mechanistic, and probabilistic evaluations.
First, a comprehensive model evaluation should be conducted in at least two
distinct geographical locations and for several meteorological episodes. Next,
streamlined evaluations can be conducted for other similar applications if the
comprehensive evaluation is deemed satisfactory. In all cases, the operational
evaluation alone is insufficient, and some diagnostic evaluation must always be
carried out. Recommendations are provided for designing field measurement
programs that can provide the data needed for such model performance evaluations.
PMID- 10786012
TI - A model for pulse jet fabric filters.
AB - A new model for pulse jet fabric filtration is proposed. In contrast to the
earlier model of Ravin and Humphries, which was formulated on the steady state
assumption, the present study is aimed at developing a predictive capability for
both transient and steady state operations, taking into account the compression
effect of filter cakes. The model's relative simplicity allows frequent updating
of the model parameter values, thus improving the accuracy of predictions. As a
result, the model is particularly useful in developing control algorithms and
designing controllers of pulse jet fabric filtration systems.
PMID- 10786013
TI - Fine particles and oxidant pollution: developing an agenda for cooperative
research.
AB - This paper describes a background for the North American Research Strategy for
Tropospheric Ozone (NARSTO) cooperative program integrating studies of O3 and
PM2.5. It discusses several important aspects for rationalizing NARSTO's
trinational investigative approach, including (1) an outlook on the state of
knowledge about fine particles in the troposphere and their origins in Canada,
Mexico, and the United States; (2) the need for enhancement and strengthening of
key field measurements in relation to tropospheric chemistry and a health effects
component; and (3) the use of a central theme for advancing air quality modeling
using evolving techniques to integrate and guide key process-oriented field
campaigns. The importance of organizing a scientific program to acquire "policy
relevant" information is stressed, noting cooperative research directions that
address combined PM2.5 and O3 issues, illustrated through exploration of
hypothetical pathways of PM2.5 response to choices of O3 and PM precursor
emission reductions. The information needed for PM2.5 research is noted to
intersect in many cases with those of O3, but diverge in other cases. Accounting
for these distinctions is important for developing NARSTO's strategy over the
next decade.
PMID- 10786014
TI - Effect of parasite screening on refugee health.
AB - Intestinal parasitic infections among refugees have been perceived as a public
health problem for decades. A control program strategy to reduce morbidity and
eventually transmission of intestinal parasites was initiated in 1993 by Mercy
International (MI) for a group of Somalia refugee and has been implemented
successfully. The management of the program operating within a comprehensive
health care project and the control activities has been performed through the
existing health facilities. This project was based on the "Comprehensive Health
Care Approach" concept and applied to a collection of 10,000 Somali refugees. A
project, which could be further, developed and modified for other similar
situations. The strategy adopted was based on periodic chemotherapy of
schoolchildren, intense health education in close collaboration with the local
community leaders. An overall reduction in prevalence of intestinal parasitic
infections of 53% was one of the targets achieved through this effort after three
years of activities. 92% and 62% reduced the intensity of Ascaris lumbricoides
and Trichuris trichiura infection, respectively. This approach in concert with
the political commitment and limited operational costs is a warranty for the
future sustainability of the control activities. Future control strategies are
tailored to the results of evaluation surveys and are targeted to the identified
high-risk areas. This project can be seen as a model in other refugee situation
with the use of limited local resources.
PMID- 10786015
TI - Effect of cyclophosphamide-mediated immunodeficiency on murine Schistosomiasis
mansoni.
AB - Four groups of female C57BL/6 mice were used. The first group was infected with
500 unattenuated cercariae. The second group was immunosuppressed by
cyclophosphamide (Cy) before infection with the same dose of cercariae. The third
group was exposed to 500 partially attenuated cercariae while the fourth group
was immunosuppressed with (Cy) before exposure to 500 partially attenuated
cercariae. In response to infection with either unattenuated or partially
attenuated cercariae, the total worm burden was significantly reduced. In the
meantime, the level of serum specific anti-SWAP IgG1 was significantly higher and
a specific band at 32 kDa was recognized in the infected groups (first and third)
compared to that in the immunosuppressed groups (second and fourth). Scanning
electron microscopy observations revealed severe damage and deformities on the
tegument of worms of the third group compared to less damage detected on the
tegument of worms in the fourth group. No obvious changes could be detected on
the tegument of worms developed from the second group compared to the first group
(controls). These observations taken together indicate that the high level of
anti-SWAP IgG1 may have a role in the elimination of schistosomes after primary
infection of mice with either unattenuated or partially attenuated S. mansoni
cercariae. Moreover, this immunoglobulin together with UV-induced attenuation
produce severe damage on the tegument of worms developed from mice exposed to
partially attenuated cercariae.
PMID- 10786016
TI - Diagnosis of toxoplasmosis in immunosuppressed mice using the polymerase chain
reaction (PCR) and the enzyme linked immuno-sorbent assay (ELISA) techniques.
AB - In the present study, Toxoplasma infection with the virulent and avirulent
strains in both immunocompetent and immunosuppressed mice was diagnosed using the
MDS ELISA for detection of CA in sera and the PCR for demonstration of DNA in
livers, brains and mononuclear cells of blood. Both techniques proved to be
convenient, especially in immunosuppressed mice.
PMID- 10786017
TI - On the morphology of Heligmosomoides polygyrus (Nematoda-Trichostrongylidae) from
the field mouse apodemus sylvaticus.
AB - The morphology of the trichostrongylid nematode Heligmosomoides polygyrus is
described by light and scanning electron microscopy. In light microscope, the
present material agrees with the original description given by Baylis (1926),
except for the addition of more details about the structure of the genital cone
and the synlophe. The scanning electron microscopy of the present nematode
revealed that the oral opening of the immature worm (L5) is rounded and its
cuticular surface is loosely attached to the body, while the oral opening of the
mature worm is triangular, the two copulatory spicules of the male are alate and
closely adhering to each other and the right lobe of the male bursa is longer
than the left one. Male prebursal and bursal papillae are described. The female
posterior extremity is characterized by crescent vulval and anal openings and a
terminal spike.
PMID- 10786018
TI - Evaluation of four pediculicides against the head lice Pediculus h. capitis.
AB - Four pediculicides were tested against head lice in-vitro. The LT50 for Licid
ranged between 10.75 (at conc. 50%) to 25.08 (at conc. 1%). All lice died with
conc. 100% within 5 minutes. With Malathion, the LT50 ranged between 4.23 to 9.3
at conc. 50% to 1% respectively. All lice died with conc. 57% within 3 minutes.
With Benzanil, the LT50 ranged between 20.85 to 44.34 at conc. 50% to 1%
respectively. All lice died at conc. 2.5% within 10 minutes. With Para plus, the
LT50 ranged between 18.46 to 29.5 at conc. 100% to 50% respectively. All lice
died with conc. 100% within 30 minutes. So, the least time needed to kill all
lice was given with Malathion (3 minutes). The least dose of pediculicide needed
to kill all lice was those of Benzanil (1% = 0.025) and Malathion (1% = 0.57).
The whole results were discussed regarding the advantages and disadvantages of
these pediculicides.
PMID- 10786019
TI - Evaluation of the IgG4 in Egyptian bancroftian filariasis.
AB - The IgG4 response against antigen extracts from Wuchereria bancrofti
microfilariae and Dirofilaria immitis adult worms was determined by ELISA in 65
Egyptian adult male patients suffering from different clinical manifestations of
W. bancrofti infection. They were divided into microfilaremic (n-35) and
amicrofilaremic (n = 30) and these divisions were subdivided into early
asymptomatic, hydrocele and late chronic elephantiasis subgroups. The IgG4
responses were significantly higher in early asymptomatic patients whether
microfilaremic or amicrofilaremic than in hydrocele or in chronic elephantiasis
(P < 0.05) & (P < 0.001) respectively. The IgG4 response was slightly higher in
microfilaremic than in amicrofilaremic subjects. The mean OD value of IgG4 among
the microfilaremics against the microfilaria antigen in early asymptomatic
patients (0.840 nm) was lower than the IgG4 response against the adult antigen in
the same group (0.960 nm), while among the early asymptomatic amicrofilaremics it
was the same (0.690 nm) in both microfilaria and adult antigens.
PMID- 10786020
TI - Modulation of the pathologic and apoptotic changes of experimental toxoplasmosis
by concomitant infection with Trichinella spiralis.
AB - This study shows that Toxoplasma gondii infection is capable of inducing a
process of programmed cell death not only in the infected hepatocytes of
experimental murine model, but also the neighbouring non-infected cells. However,
some cells showed a possible mixed apoptotic and necrotic pattern. Surprisingly,
lymphocytes and Kupffer cells in portal sinusoids nearby the parasite vacuoles
showed no apparent changes. Toxoplasma in concomitant infection with a different
parasite, Trichinella spiralis, clearly mitigate the pathologic and apoptotic
changes caused by T. gondii. These findings might help in understanding the
problematic biology and immunopathogenesis of T. gondii. The results also
augments previous reports by the same authors about the possible protective role
of heterologous antigens of one parasite against a biologically and
immunologically different parasite.
PMID- 10786021
TI - Chironomid potent allergens causing respiratory allergy in children.
AB - Generally speaking, chironomids contain potent inhalant allergens. The skin prick
tests with chironomid crude extract (Chironomus (C.) calipterus) were positive in
20 out of 25 children with respiratory allergy. The skin prick tests with house
dust mite crude extract (Dermatophagoides pteronyssinus) were positive in 3 of
these 20 chironomoid positive skin tests. Chironomid-specific IgE-ELISA were
demonstrated in the sera of 17 (85%) of the chironomid skin positive patients.
These 17 patients gave negative skin prick test to house dust mite crude extract.
It is concluded that chironomid allergens should be considered when dealing with
human respiratory allergy caused by arthropods.
PMID- 10786022
TI - Intestinal spore-forming protozoa among patients suffering from chronic renal
failure.
AB - Cryptosporidium parvum, Isospora belli, Cyclospora cayetanensis and Microsporidia
are four intestinal spore-forming protozoa that cause diarrhoea in immuno
competent individuals and immuno-suppressed patients. Fresh stool samples were
obtained from 120 patients suffering from CRF and attending the Dialysis Unit of
Zagazig University Hospital. Also, stool samples were obtained from 40 immuno
competent individuals complaining of diarrhoea (control group). The stool samples
were examined by direct smear and formol-ether concentration methods then stained
by Giemsa, Modified Ziehl Neelsen (MZN) and Aniline carbol methyl violet stains.
The four intestinal spore-forming protozoa were detected in 40/120 (33.3%) of
patients with CRF and in 2/40 (5.0%) of the control group with a statistically
highly significant difference (P < 0.001). C. parvum, Microsporidia, C.
cayetanensis and I. belli were detected in 18/120 (15%), 10/120 (8.3%), 9/120
(7.5%) and 3/120 (2.5%), respectively. The four protozoa were found as mixed
infections with other pathogens or as single infections confirming their role
alone as a cause of diarrhoea. MZN stain was the most efficient simple, and not
expensive.
PMID- 10786023
TI - Larvicidal activity of Commiphora molmol against Culex pipiens and Aedes caspius
larvae.
AB - Myrrh (oleo-gum-resin) obtained from the stem of Commiphora molmol proved to have
insecticidal activity against mosquito larvae. The oil extract of Myrrh possesses
median lethal activity against 2nd, 3rd and 4th instar larvae of Culex pipiens at
0.016 x 10(2), 0.17 x 10(2) & 1.6 x 10(2) g/l respectively. While LC50 against
3rd instar larvae of Aedes caspius was 0.2 x 10(2) g/l. The oleo-resin extract
showed toxicity against 2nd, 3rd, 4th instar larvae of C. pipiens recording the
LC50 values of 0.06 x 10(2), 0.09 x 10(2) & 0.5 x 10(2) g/l respectively. While
LC50 against 3rd instar larvae of A. caspius was 0.08 x 10(2) g/l. This plant
extract has no marked toxic effect against the water bug Sphaerodema urinator
(Dufor) and the water beetle Hydaticus leander (Rossi). Histological examinations
of Myrrh treated mosquito larvae showed great pathological effect on their fat,
muscles, gut and nervous tissues.
PMID- 10786024
TI - Effect of ivermectin on the brown dog tick, Rhipicephalus sanguineus.
AB - Ivermectin (Ivomec) proved to be effective in controlling R. sanguineus. All
brown dog ticks infesting the treated dogs (subcutaneous injections) with 1.5 ml
or 2 ml/50 kg dropped off within 4 or 3 days respectively. The dropped off ticks
were completely inactive and died within one day or two. Ticks exposed to filter
papers impregnated with 100 micrograms/ml (66.67%) died within four days. A dose
of 1.5-2 microliters/50 kg eradicated Toxocara canis infection in four dogs, and
caused shrinkage of Dipylidium caninum gravid segments in three. A general
discussion was given with special reference to the contraindications and side
effects of ivermectin particularly for human usage.
PMID- 10786025
TI - SDS-PAGE-separated tissue proteins of Biomphalaria alexandrina snails in the
presence and absence of Schistosoma mansoni.
AB - SDS-PAGE was used to separate tissue proteins of control and trematode-infected
Biomphalaria alexandrina snails. The separated profiles demonstrate the
occasional appearance of protein fractions and the remarkable increase of
concentration of certain molecular masses in infected snails at one week interval
over four weeks post exposure to Schistosoma mansoni. Proteins of molecular
masses of 44, 56, 65 and 144 KDa were among these occasionally appeared protein
masses. Post exposure to S. mansoni larval infection, a protein mass of 36 KDa
was predominant giving a markedely higher absorbance (> 1) compared to control
(0.0166). This was identified as lactate dehydrogenase enzyme. Moreover, a
protein of 56 KDa mass was identified as Pyruvate kinase. The predicted induction
of these two enzymes could be either of host and/or parasitic origin. This study
revealed that S. mansoni- B. alexandrina complex has a completely different
protein pattern compared to control with very low similarity coefficient "S"
value. A correlation between the snail tissue protein or separation patterns and
the metabolic redirection of the snail host by the developing sporocyst was
discussed.
PMID- 10786026
TI - An experimental vaccine providing heterologous protection for Leishmania species
in murine model.
AB - Five groups each of 20 BALB/C mice were immunized by heat killed L. donovani
promastigotes. Two groups served as control. Each group of mice was subdivided
into 2 equal subgroups and challenged with either L. donovani or L. major. The
results revealed a high cross reactivity paralleled by a high cross protection
between L. donovani and L. major. Heat killed L. donovani promastigotes super
passed other tested SDS-PAGE fractionated and eluted L. d. fractions identified
by immune BALB/c mice in providing protection against both L. donovani and L.
major. The percentage of protection (reduction in parasite burden) offered by
each vaccine was as follows: 80.21%, 36.11%, 9.29%, 33.44% and 17.48%
respectively against challenge infection with L. donovani and 3.012 x 10(4),
1.095 x 10(4), 6.054 x 10(2), 2.409 x 10(4), and 3.34 x 10(2), respectively
against challenge infection with L. major.
PMID- 10786027
TI - Serum pretreatment with Schistosoma mansoni antigens for serological diagnosis of
fascioliasis.
AB - Cross-reactivity between Fasciola and Schistosoma often causes false positive
results in serological assays for diagnosis of fascioliasis. The authors tried to
reduce cross-reactivity in ELISA for diagnosis of fascioliasis by preincubation
of serum samples with a mixture of Schistosoma mansoni adult worm and egg
antigens. This method was evaluated using serum samples from 4 groups: 25
patients infected with Fasciola, 40 healthy controls, 113 patients infected with
S. mansoni and a group of 100 patients with suspected Fasciola infection. In
group with confirmed Fasciola infection, the sensitivity of ELISA was 96% without
any change after serum pretreatment while, in control group, the specificity was
elevated from 90% to 97.5% after serum pretreatment with S. mansoni antigens. In
S. mansoni infection and suspected Fasciola infection groups, there was a highly
significant reduction in number of ELISA positive cases after serum pretreatment
with S. mansoni antigens (McNemar P < 0.001 for each). In logistic regression
model, seroconversion showed significant dependence on presence of S. mansoni
infection (P = 0.012). The probability of seroconversion was more than three
times higher in S. mansoni infected individuals than in non-infected ones (Odds
ratio = 3.5).
PMID- 10786028
TI - Efficacy of cryotherapy and intralesional pentostam in treatment of cutaneous
leishmaniasis.
AB - Forty-two CL patients with 60 lesions were treated with cryotherapy using liquid
nitrogen twice for two months. Another group of fifty-five CL patients. With 73
lesions were treated with intralesional pentostam with pentostam, 67 of 73
lesions (92%) and with cryotherapy 47 of 60 lesions (78%) healed or markedly
improved at the end of three months follow-up. This study shows that
intralesional pentostam injection was effective than cryotherapy. However, both
lines of treatment were well tolerated by the patients. They showed no severe
side effects and no significant changes in laboratory values. It is suggested
that cryotherapy is an alternative to intralesional pentostam injection.
PMID- 10786029
TI - Treatment of cutaneous leishmaniasis patients with pentostam via intralesion
infiltration.
AB - Cutaneous leishmaniasis (CL) is an endemic disease in Egypt. Systematic treatment
with pentostam has its disadvantages and contraindications. In this study, six
out of eight parasitologically proved CL patients recovered with intralesion
infiltration with a dose of pentostam ranged between 0.8 to 1.6 gm. The other 2
patients did not show response with a dose up to 2 gm. The results were
discussed.
PMID- 10786031
TI - Ultrastructure studies on the nervous system of the land snail Eobania
vermiculata (Gastropoda: Stylommatophora).
AB - The ultrastructure of the different ganglia of the nervous system of the land
snail had been investigated. This study had revealed that the neurosecretory
granules are apparently formed from the Golgi apparatus and in other cases, the
neurosecretory granules appeared to be related to the rough endoplasmic
reticulum. The nuclei of the pedal, pleural, parietal and visceral ganglia are
irregular polymorphic in shape. The fine structure of the neurosecretory cells
was the point of interest in the present investigation.
PMID- 10786030
TI - Cystatin capture enzyme-linked immunosorbent assay for serodiagnosis of human
schistosomiasis mansoni.
AB - To diagnose human schistosomiasis mansoni, the current study tested an ELISA
system that employs indirectly, through a chicken cystatin capture agent, the S.
mansoni cysteine proteinases as antigens to detect IgG anticysteine proteinases.
The study examined 40 patients with S. mansoni, 20 patients with parasitic
infections other than schistosomiasis mansoni, and 20 apparently healthy
individuals with no parasitic infections. The results showed that the cystatin
capture ELISA gave a high sensitivity of 100% even in patients with low egg
count. A similar high sensitivity was also recorded with conventional ELISA using
SWAP alone without presensitization of ELISA plate with cystatin. Moreover, the
capture ELISA showed no cross reactions with patients with other parasitic
infections or normal individuals giving a 100% specificity, while the
conventional ELISA using SWAP alone gave a lower specificity of 85%. The cystatin
capture ELISA was found to be an easy, highly sensitive and specific serological
method for the diagnosis of human schistosomiasis mansoni without the need of
purified proteinases antigens.
PMID- 10786032
TI - Ultrastructure of sperm and spermatogenesis of Cichlidogyrus thurstonae
(Platyhelminthes, Monogenea, Monopisthocotylea).
AB - The present work is the first ultrastructural description of mature spermatozoon
of the monogenetic trematode Cichlidogyrus thurstonae recovered from the gills of
the Nile fish Oreochromis niloticus. The mature spermatozoon of C. thurstonae is
long and filiform with a nucleus, mitochondrion and a single axoneme, pressed
tightly together for most of their length. As most other platyhelminthes, a solid
central unit in the complex central element of the sperm axoneme is present.
There are no peripheral microtubules in the sperm and the arrangement conforms to
the sperm pattern 4 in the scheme of Justine et al. (1985).
PMID- 10786033
TI - Toxicity of a Neem (Azadirachta indica) insecticide to certain aquatic organisms.
AB - Neem based insecticides are likely to show a large increase in use in the near
future. In the present work, the toxicity of a neem insecticide, Neem-Azal-T/S,
was tested against the mosquito larvae, as well as against certain non target
organisms occurring in a polluted pond and a shallow stream, located in a
cultivated area in Giza, Egypt. Samples of water containing the experimental
animals were collected from this area, and toxicity tests were conducted in the
laboratory by exposing them to a series of concentrations of the botanical
insecticide, using the water of the pond and stream at room temperature (28-31
degrees C). The compound was more or less toxic to all the tested species. The
LC50S and mortality rates were determined. The order of tolerance of the
organisms to different concentrations of the insecticide was: larvae of Bufo
regularis (Amphibia) > Aedes caspius. (Insecta) > Gambusia affinis (Poeciliidae)
> Cyclops sp. > Daphnia magna (Crustacea). At a concentration of 20 ppm, all the
tadpoles died within 9 days, while all other individuals died within 5 to 8 days
after exposure to a concentration of 10 ppm of Neem Azal insecticide.
PMID- 10786034
TI - Epidermal growth factor in patients with schistosomal and/or viral liver diseases
and portal hypertension.
AB - A large number of growth factors have been described and their action and
interaction is proving to be complex. The presence study estimated the epidermal
growth factor (EGF) in portal hypertension patients with chronic liver disease
due to bilharziasis or viral infection as well as in patients with peptic ulcers.
The results showed different statistical values regarding liver cirrhosis,
oesophageal varices, and bleeding. No doubt, the EGF was indirectly stimulated by
the schistosomal and/or viral infection.
PMID- 10786035
TI - Different cytokines profiles in spleen cells and liver granuloma of Schistosoma
mansoni experimentally infected mice during disease development.
AB - To determine the importance of Th1 and Th2 cells in modulating granuloma
formation, mRNA transcripts for Th1 (IL-2 and IFN-gamma) and Th2 (IL-4 and IL-5)
cytokines were assessed by the molecular technique of in situ hybridization in
the liver granuloma. The molecular studies showed few number of cells expressing
mRNA transcripts for INF-gamma whereas, considerable number of IL-2 cells were
present in the liver granuloma at 6 weeks post-infection (p.i.). Complete
disappearance of IFN-gamma expressing cells were found when the disease
progressed to 13 weeks p.i. Conversely, very high number of cells expressing mRNA
transcripts for IL-4 and fair number of IL-5 cells were present at 7 weeks p.i.
with a peak level of IL-4 cells at 13 weeks p.i. These in situ molecular studies
of the liver tissues, demonstrated that Th1 cells were present at the very early
granuloma development. Moreover, Th2 cells were required for its full
development. The main interesting finding was the number of cells expressing mRNA
for IL-4, as they were very huge and it might exceed the total number of
lymphocytes per se in the granuloma. Lymphocytes from experimentally infected
mice-spleen cells were also cultured in vitro with S. mansoni soluble egg antigen
(SEA) and the same cytokines of lymphocyte supernatant were measured by ELISA
assay. The levels of IFN-gamma and IL-2 were high to 6 wk. p.i. with a slight
decline of IFN-gamma, and increasing amount of IL-2 at 10-13 wk p.i. Spleen
lymphocytes of fully formed granuloma secreted high levels of IL-4 and IL-5. The
results suggest that the development of schistosome egg-induced liver granuloma
is a complex process and both Th1 and Th2 cell subsets sharing with other
inflammatory cells (non lymphocytes), may play an important role in regulating
and modulating the immuno-pathology of granuloma formation and the subsequent
hepatic fibrosis.
PMID- 10786036
TI - The use of colchicine in treatment of experimental toxoplasmosis.
AB - Colchicine was given in 2 doses (3 and 15 micrograms/mouse) at the time of
infection or 48 hours late. It proved effective in both doses, but better results
were obtained with early treatment. The mortality rates were 30% & 30%, and
Toxoplasma carriers among the surviving mice was 28.6% and 42.9% with high and
low doses respectively. When the treatment was given 48 hours after infection,
the mortality rates were 50% and 60%, Toxoplasma carriers were 40% and 50% with
high and low doses respectively.
PMID- 10786037
TI - Isolation of dust mites from houses of Egyptian allergic patients and induction
of experimental sensitivity by Dermatophagoides pteronyssinus.
AB - Six house dust mite (HDM) species were isolated from dust of floors and
mattresses of allergic patients houses in Alexandria. Dermatophagoides
pteronyssinus (D.p.) was the dominant species in dust of floors and mattresses
with average percentages of 68.9% and 78.3% respectively. It was used to induce
experimental sensitivity in Swiss albino mice by repeated weekly intranasal
instillation of D.p. mites in phosphate buffer saline (PBS). Cytological
examination of bronchoalveolar lavage (BAL) fluid of mice revealed prolonged
eosinophilia, that peaked on day 28 of the experiment and persisted till the end
of the study. Blood eosinophilic counts were progressively increased during the
course of the experiment. Histopathological findings showed evident eosinophilic
infiltration in nasal and lung tissues of the sensitized mice. Specific IgE
response to D.p. was progressively increased, reaching 30 times higher than the
control group on day 42. The detected levels of interluekin-4 (IL-4) were in
accordance with immunoglobulin response. D.p. provoked severe allergic response
and this may help to design an effective therapy to ameliorate such allergic
diseases.
PMID- 10786038
TI - A study of the predisposition of Schistosomiasis mansoni to pyogenic liver
abscess in experimentally infected mice.
AB - In murine experimental model, the present work was carried out to study the
possible predisposition of S. mansoni infection to pyogenic liver abscess,
through a concurrent infection with Staphylococcus aureus. Pyogenic liver
abscesses containing the bacterial organism were found in 85% of mice infected
with concurrent early S. mansoni infection and S. aureus, in 35% of mice with
late S. mansoni infection and the bacterial infection, and in 60% of mice with
concurrent immunosuppressed late St. mansoni infection and staphylococcal
infection. The early S. mansoni infection, immunosuppressed late schistosomiasis
mansoni, and to a less extant late schistosomiasis mansoni, with concurrent
bacterial infections can predispose to pyogenic liver abscess which has
implicative effect on clinical cases.
PMID- 10786039
TI - Correlation between trichomoniasis vaginalis and female infertility.
AB - Trichomoniasis vaginalis is one of the common parasitic infection in females. The
present results showed that infertile women with T. vaginalis with or without
pathogenic microorganisms have decreased C3 & C4, increased IgA level in vaginal
discharge and increased serum prolactin. So. T. vaginalis is incriminated as one
of the causes of their infertility.
PMID- 10786040
TI - Experimental trials of an artemisinin derivative in treatment of Schistosoma
mansoni infected mice.
AB - Dihyroartemesinin, an artemesinin derivative, was used for treatment of mice
experimentally infected with S. mansoni. A significant decrease in total worm
count was recorded when mice were treated during early and late stages of
infection. Histopathological examination of liver sections showed minimal
pathological changes with early treatment and enhanced fibrosis of granulomas
with late treatment. The results showed that dihydroartemesinin had a promising
effect on S. mansoni infected mice almost comparable to that of praziquantel.
PMID- 10786041
TI - The effect of antioxidant preparation (antox) on the course and efficacy of
treatment of trichinosis.
AB - This study evaluated the effect of administration of exogenous antioxidant
(antox) on the course and treatment of Trichinella spiralis in the intestinal
phase (2 days post infection, p.i.) and the muscle phase (35 days p.i.) using
albino rats as an experimental model. The results indicated that the
administration of antox had led to delayed expulsion of adult worms from the
small intestine, decreased inflammatory reactions in the intestines and muscles
and causing an increase in the muscle larval burden. The intake of antioxidant
decreased the efficacy of mebendazole on adult worms in the intestinai phase,
while it enhanced the effect of treatment in the muscle phase and the number of
larvae was highly decreased. So, antox inhibited free radical generation in small
intestine which acts as a contributing factor to the rejection process. But, in
muscle phase, the decreased inflammatory reaction around larvae increases the
chance of the drug to reach larvae and affects them.
PMID- 10786042
TI - The influence of Bacillus sphaericus on the biology and histology of Phlebotomus
papatasi.
AB - This work was achieved to study the impact of B. sphaericus treatment on some
biological aspects of P. papatasi. Contaminated larval food with B. sphaericus
(strain-2362) in different concentrations was offered in the laboratory for P.
papatasi and also the latent effect on the fecundity of survived females from
previously treated larvae. There was a decrease in the survived numbers of
immature stages and adults correlated to the concentrations, while there was no
obvious change in the larval and pupal durations compared to the control. The
fecundity of females survived from previously treated larvae, was sharply
decreased. Many variations was noticed in the examined tissues of mid-gut, fat
tissues, and Malpighian tubules, although no bacteraemia was detected.
PMID- 10786043
TI - Scabies in some workers living in crowded area, Jeddah, Saudi Arabia.
AB - Little is known about human and animal scabies in Jeddah. The present study gives
a picture of human scabies. Over four months, 18 cases have been microscopically
diagnosed. The most common infested site was the abdomen, followed by the lower
and upper limbs. Infestation in other parts of the body was not common but also
recorded. The results were discussed on the light of other works done in the
region.
PMID- 10786044
TI - A preliminary screening study on human cystic echinococcosis in Cairo slaughter
house personnel.
AB - A descriptive serological screening study was done on human cystic echinococcosis
(CE) in high risk groups selected from Cairo slaughter house employees and the
household nearby using indirect haemagglutination (IHA) and enzyme-linked
immunoelectrotransfer blot (EITB) tests. Characterized camel hydatid cyst fluid
(HCF) antigen by 12.5% sodium dodecyl sulphate polyacrylamide gel electrophoresis
(SDS-PAGE) was used. Three asymptomatic clinical cases (1.3%) were seropositive
using EITB assay (reacting with six HCF protein bands of molecular weights
approximately 7, 21, 28, 35, 127 and 210 kilodaltons 'kDa') but one case was
seronegative by the IHA test. All three cases had typical lesions of CE in liver
and lung revealed by abdominal ultrasonography (US), computerized tomography (CT)
scan and chest X-ray. The prevalence of CE in Cairo slaughter house workers was
1.6% versus 1.1% in the household nearby.
PMID- 10786045
TI - Scanning electron microscopy of the tegumental surface of digenetic trematode
Stephanostomum egypticum from the Red Sea fishes.
AB - Surface topography of Stephanostomum egypticum (Ramadan, 1983) is described by
Scanning electron microscope, revealed three morphologically different types of
spines; forty flattened circum-oral spines arranged in 2 circular rows; forty
longitudinal rows of highly projecting thick spines covering area between oral
and ventral suckers and rather flattened and sporadic tegumental spines covering
the body posterior to the ventral sucker. High magnification showed the spines
either single or double pointed with the first type most common. The present
study revealed the presence of four types of sensory papillae: domed around the
suckers, small button-like aggregated on the ventral sucker and near the bases of
the spines; short and long ciliated ones near the posterior extremity of the
fluke. High magnification of tegumental surface showed it to be covered with
several bleb-like structures. The functions of all these tegumental structures
were speculated and discussed was given.
PMID- 10786046
TI - [Corneal wound healing after penetrating keratoplasty with EGF application.
Experimental studies].
AB - PURPOSE: To check post penetrating keratoplasty (PK) corneal wound healing
characteristics after epidermal growth factor (EGF) application and to compare it
with controls. MATERIAL AND METHODS: The PK was performed in the group of 72
young, healthy New Zealand rabbits (36 females and 36 males). Slit-lamp
examination, tonometry and corneal topography by Tomey's corneal modeling system
(TMS-1) were carried out before and after surgery. The PK was performed in both
eyes. Half of animals were used as a bilateral donor for the other half, with a
rule: right eye cornea to the right eye and left eye cornea to the left eye. As a
result, after completed surgery 36 rabbits had bilateral grafts. The animals were
divided into 3 equal groups (12 in each). Two drops of the human recombined EGF
dissolved in the saline solution with concentration varied from 500 to 1500 ng in
each drop were applied to the right eye according to schedule. The left eye was
used as a control and did not receive EGF. Time of observation varied from 24
hours to 6 months. The tensinometry and the histopathologic study--light and
electron microscopy were performed to determine corneal scarring. RESULTS: The
wound healing pattern after PK was characteristic and constant in each group. The
corneal wound healing significantly accelerated in the EGF treated group of
rabbits compared with the controls (p < 0.05). In the group of rabbits receiving
1000 ng of hrEGF 3 times/day, after two weeks of application we noted increase of
the wound strength up to 600 folds, comparing with controls. Well-organized scar
was histologically seen on the 21st post-surgery day. The post-operative corneal
astigmatism was less expressed in the eyes treated with EGF comparing to
controls. CONCLUSIONS: These preliminary results of our experimental study
indicated accelerated effect on the corneal wound healing after PK with topical,
low dose hrEGF application. Clinical observation of utilization of similar low
doses of the hrEGF after PK--is in progress.
PMID- 10786047
TI - [Application of amniotic membrane transplantation in severe corneal diseases].
AB - PURPOSE: To present our experience with the amniotic membrane transplantation in
severe corneal diseases. MATERIAL AND METHODS: In 1998 amniotic membrane
transplantation was applied in 18 eyes (17 patients) with severe and persistent
corneal diseases. The indications were as follows: perforated corneal ulcer--9
eyes, persistent non-perforated corneal ulcer--4 cases, recurrent transplant
disease--2 eyes, 1 patient with Sjogren syndrome and 1 with keratolysis in the
course of ulcerative colitis. Amniotic membrane was prepared in the International
Eye Bank of Lublin from human placenta after elective caesarean section according
to the standard protocol. RESULTS: In 7 eyes with perforated ulcers and 4 eyes
with non-perforated ulcers prompt healing was observed. In 4 cases markedly
improved visual acuity resulted from corneal clarification. In 1 eye perforation
persisted in spite of amniotic membrane transplantation and keratoplasty was
performed afterwards. In the case of keratolysis, amniotic membrane
transplantation did not prevent corneal perforation which was closed successfully
with autologous conjunctival flap. In 2 eyes with recurrent transplant disease
amniotic membrane dissolved quickly after transplantation. In one case the state
of the cornea improved. The second eye required retransplantation of the
membrane. We observed that amniotic membrane dissolved more quickly in a
vascularized bed. CONCLUSION: Amniotic membrane transplantation may be considered
a good alternative method for treating severe corneal disorders that are
refractory to conventional treatment.
PMID- 10786048
TI - [Eye with implanted keratoprosthesis in ultrasound biomicroscopy].
AB - OBJECTIVE: Of the study is to assess the possibility of the ultrasound
biomicroscopy (UBM) in diagnosis of the eyes with implanted Fiodorov-Zujev's
keratoprosthesis. MATERIAL: We examined 10 eyes of 10 patients, 3 females and 7
males. The patients were 12 to 17 years after the second stage of
keratoprosthesis implantation (mean 14.9 +/- 1.37). METHODS: The examinations
were performed with the use of ultrasound biomicroscope (Humphrey Instruments
model 840). RESULTS: UBM made it possible to visualise keratoprosthesis and many
complications: decentration of keratoprosthesis, thinning of anterior part of
leucoma, shallowing of anterior chamber, very narrow angle of filtration,
retroprosthetic membrane-like structures.
PMID- 10786049
TI - [The alterations in corneal structure at III/IV stage of keratoconus by means of
confocal microscopy and ultrasound biomicroscopy before penetrating
keratoplasty].
AB - PURPOSE: The aim of the study was in-real time observation and morphological
evaluation of the human corneas at III/IV stage of keratoconus, using the
scanning slit confocal microscope Confoscan P4 and ultrasound biomicroscopy--UBM.
MATERIAL AND METHODS: The patients with keratoconus were examined according to
the Amsler scale. The material consisted of 12 corneas of 11 patients (8 men, 3
women), where assessment of the corneal structure was performed with the confocal
microscope ConfoScan P4 (Tomey) and ultrasound biomicroscopy--UBM Model 840
(Humphrey Instruments). The comparison of different corneal regions (central and
peripheral) was evaluated. RESULTS: The confocal microscopy and UBM revealed
thinning of the layers of the corneal structure and pathological changes in the
central area, especially at IV stage of keratoconus. The desquamating superficial
cells were elongated, arranged around the apex of the cornea. Below the Bowman's
membrane a considerable disarrangement of collagen fibers reflected by bright
background illumination was observed. In the posterior part of the stroma the
folds were detected. The examination of the cornea showed thickening in the
peripheral part, central detachment of the Descemet's membrane and the
endothelium from the posterior surface of the cornea. The thickness of the cornea
varied from 0.201 to 0.384 mm in the central part and 0.675 to 0.740 mm in the
peripheral area. CONCLUSION: Confocal scanning microscopy combined with
ultrasound biomicroscopy enables the cornea to be examined in vivo. It can be
used to localize pathological changes in individual corneal layers and to assess
their extent.
PMID- 10786050
TI - [Implantation of posterior chamber lenses with trans-scleral fixation].
AB - PURPOSE: The aim of this study is the presentation of our experiences in
implantations of posterior chamber lenses with transscleral fixation. MATERIAL
AND METHODS: The surgery was performed in 66 patients (66 eyes) using modified
technique described by Lindquist et al. Primary implantations were performed in
53% subjects, in the remaining secondary implantations. RESULTS: After surgery we
achieved visual acuity improvement in 80.3%, good visual acuity (0.5-1.0) in
68.4% of subjects. The main postoperative complications were: deformation of the
pupil and decompensation of corneal endothelium. CONCLUSIONS: Implantation of
posterior chamber lenses with transscleral fixation is preferable (alternatively
for anterior chamber lenses) in young patients as well as in subjects with
glaucoma, elevated intraocular pressure, iris coloboma and corneal problems.
PMID- 10786051
TI - [Comparative evaluation of visual acuity after cataract extraction with
monofocal, bifocal or progressive lenses implantation].
AB - PURPOSE: Evaluation which of the lenses: monofocal, bifocal or progressive,
assure the best visual acuity in patients. MATERIAL AND METHODS: 86 patients aged
from 21 to 84 years were operated. Monofocal lenses were implanted in 30 cases,
bifocal in 32 and progressive in 24 cases. RESULTS: In 90% of patients with
monofocal lenses and over 90% of patients in the remaining groups full
uncorrected or corrected distance visual acuity was achieved. In groups with
bifocal and progressive lenses full near visual acuity without correction, or
with the same correction as for distance, was achieved by respectively 65.5% and
75% of patients. CONCLUSIONS: In all three groups very good distance visual
acuity was achieved. The best near visual acuity is assured by progressive
lenses, in lower degree by bifocal lenses.
PMID- 10786052
TI - [Variations of Doppler blood flow parameters in central retinal artery in
relation to position of sample volume].
AB - PURPOSE: To determine variability in measurements of Doppler blood flow
parameters in central retinal artery in relation to sample volume location from
the optic disc. MATERIAL AND METHOD: Eighty central retinal arteries were
examined using color Doppler ultrasonography in 40 healthy volunteers (22 female,
18 male), aged 45 +/- 9 with 7.5 MHz linear-array probe. The measurements of
blood velocities and resistance indices in the arteries were obtained at points
where distance from optic disc surface ranged from 1.5 mm to 6 mm. RESULTS: Blood
velocities increased significantly when sampled closer to the globe (r = -0.61,
and r = -0.32 for peak-systolic and end-diastolic velocities, respectively). Mean
peak-systolic velocities were 13.0 +/- 2.7 cm/s when distance 2.1 +/- 0.46 mm
from optic disc, and 9.3 +/- 2.5 cm/s when distance 4.27 +/- 0.9 mm. Mean end
diastolic velocities were 4.3 +/- 1.2 cm/s and 3.6 +/- 1.1 cm/s, respectively.
Resistance indices inclined to increase when the distance between the measurement
site and the globe shortened. Resistance indices were 0.67 +/- 0.06 when measured
closer to the globe and 0.60 +/- 0.06 when measured farther from it. CONCLUSION:
Position of sample volume in relation to optic disc has to be taken into account
and defined if measurements of blood flow Doppler parameters of the central
retinal artery are to be reproducible.
PMID- 10786053
TI - [Blood flow parameters in ocular vessels of patients with glaucoma].
AB - PURPOSE: To determine Doppler flow parameters in ocular vessels of glaucomatous
patients. MATERIAL AND METHODS: 38 glaucomatous patients, aged 64 +/- 16, and 57
healthy volunteers were examined with 7.5 MHz linear-array probe. Consistently
identified arterial structures included ophthalmic artery, central retinal artery
and short posterior ciliary arteries. The peak systolic, end-diastolic and mean
velocities were measured from Doppler spectra. Resistance and pulsatility indices
were also determined. RESULTS: End-diastolic and mean velocities in central
retinal artery of glaucomatous eyes were: 1.5 +/- 1.9 cm/s, 4.0 +/- 2.0 cm/s,
whereas in healthy eyes they were significantly higher: 3.5 +/- 1.0 cm/s, 5.4 +/-
1.5 cm/s, respectively. These velocities in short posterior ciliary arteries in
glaucomatous patients were significantly lower: 2.4 +/- 2.3 cm/s, 5.6 +/- 2.2
cm/s, comparing to healthy subjects: 4.8 +/- 1.7 cm/s, 7.3 +/- 2.2 cm/s.
Resistance and pulsatility indices in central retinal artery and short posterior
ciliary arteries were significantly higher in the group of patients: RI = 0.85 +/
0.18, PI = 2.11 +/- 0.92--in central retinal artery and RI = 0.81 +/- 0.18, PI =
1.96 +/- 0.91--in short posterior ciliary arteries, comparing to healthy
subjects: RI = 0.61 +/- 0.08, PI = 1.20 +/- 0.17--in central retinal artery, RI =
0.61 +/- 0.09, PI = 1.13 +/- 0.18--in short posterior ciliary arteries. Impedance
indices were increasing progressively with intraocular pressure elevation. There
were no significant differences of Doppler blood flow parameters in ophthalmic
artery between patients and control group. CONCLUSIONS: Blood flow velocities in
central retinal and short posterior ciliary arteries are lower, and resistance
and pulsatility indices are higher in glaucomatous eyes in comparison to healthy
subjects, whereas in ophthalmic artery doppler parameters are similar in both
groups.
PMID- 10786054
TI - [Evaluation of fraxiparine efficacy in the treatment of retinal vein occlusion].
AB - PURPOSE: To evaluate the efficacy of Fraxiparine in the treatment of central
retinal vein occlusion and retinal branch vein occlusion. METHODS: 30 patients
were treated. Fraxiparine (Sanofi-Pharma) was injected subcutaneously in doses of
7.5 thousand units twice daily for 10 days and once daily for 18 days. In 19
cases central retinal vein occlusion was observed and retinal branch vein
occlusion in 11 cases. Mean follow-up was 15 months (range 10-35 months).
Ophthalmological examination including fluorescein angiography was performed
before and after therapy. RESULTS: Improvement of visual function and condition
of retina after therapy was observed in about 50% of cases. In 16 patients laser
photocoagulation applied for neovascularisation or retinal edema was necessary.
PMID- 10786055
TI - [The evaluation of morphological status of bulbar conjunctiva after long-term
antiglaucoma drug therapy].
AB - The aim of this study was to examine the histopathologic picture of bulbar
conjunctiva in glaucoma patients receiving topical antiglaucoma treatment.
MATERIAL AND METHODS: Generally healthy patients with primary open angle glaucoma
(POAG) and primary angle closure glaucoma (PACG) were included in our study.
Conjunctiva specimens were obtained from the area of further fistula of 51
patients undergoing trabeculectomies and assessed by routine histopathological
staining. RESULTS: Non-specific inflammatory infiltration, thickening of the
epithelium, decreased numbers of Goblet cells, proliferation of fibroblasts,
collagen deposition and fibrosis were observed in the obtained material. Changes
in cellular profile and in the extracellular composition of bulbar conjunctivas
in patients receiving long-term topical antiglaucoma treatment were detected.
PMID- 10786056
TI - [Valve implants of glaucoma pressure regulator for refractory glaucoma: own
experience].
AB - PURPOSE: To present our experiences in valve implantation for refractory
glaucoma. MATERIAL AND METHODS: From October 1993 to December 1996 implantations
of Glaucoma Pressure Regulator Optimed were performed in 7 eyes of 7 patients.
There were 4 men and 3 women aged from 32 to 65 years. There were 3 eyes with
neovascular glaucoma due to diabetes mellitus, 2 eyes with posttraumatic
glaucoma, including 1 case after keratoplasty, 1 eye with postkeratoplasty
glaucoma and 1 eye with aphakic glaucoma. Preoperative IOPs ranged from 33 to 61
mm Hg (mean 37.6 +/- 7.2 mm Hg). RESULTS: Success was considered an IOP of less
than 22 mm Hg without medication (complete success) or with medication (qualified
success) without additional filtering surgery. Postoperative success was obtained
in 4 out of 7 eyes after follow-up period of 37.4 +/- 17.08 months (range 16-39
months). Early complications were hyphema (1 patient, 14.3%), blockage of
intracameral portion of the tube (1 patient, 14.3%), hypertony (1 patient,
14.3%). Late complications were: external conjunctival bleb failure (2 patients,
28.6%), blockage of intracameral portion of tube by fibrovascular tissue (1
patient, 14.3%). CONCLUSION: Our experiences confirm that the valve implant is
still today an alternative surgical procedure for controlling IOP in eyes with
refractory glaucoma that have visual potential.
PMID- 10786057
TI - [Helicobacter pylori as supposed factor of uveitis in children: a case report].
AB - MATERIAL: A case of a 14-year-old boy with recurrent idiopathic bilateral
uveitis. METHODS: Detection of Helicobacter pylori infection basing on endoscopic
examination of upper alimentary tract and eradication of this factor using
specific therapy leading to extinction of active uveitis in both eyes. RESULTS:
Helicobacter pylori may be the etiological agent of uveitis in children with
unknown reason of the disease.
PMID- 10786058
TI - [Cellular reactions after intraocular lens implantation].
AB - The surgical trauma and the presence of the artificial lens in the eye causes
inflammatory reactions. The cellular response is a result of 1) the breakdown of
the blood-aqueous barrier, 2) foreign body reaction induced by lens material. The
presence of cellular deposits (small, fibroblast-like, epithelioid, giant cells)
on the surface of intraocular lenses is related to many factors such as surgical
technique, risk factors of inflammation, postoperative treatment and the kind of
lens material. The aim of this paper is to present contemporary knowledge about
cytopathology of intraocular lenses and chances to improve the surface
characteristic to avoid the adhesion of cells.
PMID- 10786059
TI - [Kinurenin degradation pathway in eye: present state of knowledge].
AB - In this review the kinurenin degradation pathway is presented. The role of
indoleamine 2.3-dioxygenase (IDO)--the first enzyme of the tryptophan degradation
-is also described. The implications of these findings for cataract as well as
for other disturbances of vision process are discussed.
PMID- 10786060
TI - [Contemporary views on the etiology, pathogenesis as well as treatment of school
age and progressive myopia].
AB - The contemporary views on the etiology, pathogenesis as well as treatment of
school-age and progressive myopia are discussed. The history of myopia
investigations is described. The results of papers indicating environmental and
genetic reasons of myopia are presented. The anatomical, physiological, and
biochemical changes taking place during the school-age and progressive myopia
progress are characterized. The attitude towards some conservative and surgical
methods of school-age and progressive myopia is expressed. The possibilities of
using the newest experimental results in progressive myopia treatment are
indicated.
PMID- 10786061
TI - [Electroretinogram and electrooculogram in retinal degeneration].
AB - Electroretinogram (ERG) and electrooculogram (EOG) are fundamental for proper
early diagnosis of retinal dystrophies and degenerations. The most characteristic
changes of ERG and EOG in such retinal dystrophies as Stargardt's disease, Best's
disease, fundus flavimaculatus, fundus albipunctatus, retinitis pigmentosa,
choroideremia, iuvenile retinoschisis, congenital stationary night blindness,
progressive cone dystrophy and in some of retinal degenerations for differential
diagnosis were described. Electrophysiological state of retina in retinal
dystrophy depends on patient's age and pattern of inheritance. Very often typical
for dystrophy changes in ERG and EOG without any visible pathology on eye fundi
are found. On the other hand there are some of degenerations similar to
dystrophies in clinical examination. In such cases only ERG and EOG allow to be
sure which diagnosis should be done.
PMID- 10786062
TI - Statistical support for uncertainty in radiological diagnosis.
AB - Radiological interpretation and diagnosis involves the comparison and
classification of complex medical images and is typical of the categorisation
tasks that have been the subject of observational studies in Cognitive Science.
This paper considers the affinity between statistical modelling and theories of
categorisation for naturally occurring categories. Statistical based measures of
similarity and typicality with a probabilistic interpretation are derived. The
utilisation of these measures in the support of diagnosis under uncertainty via
interactive overview plots is described. The application of the methodology to
magnetic resonance imaging of the head is considered. The methods detailed have
application to other fields involving archiving and retrieving of image data.
PMID- 10786063
TI - Utility of the Charlson comorbidity index computed from routinely collected
hospital discharge diagnosis codes.
AB - This study aims to determine whether the Charlson comorbidity index computed from
ICD-9-CM discharge diagnosis codes adds additional information to a model
containing adjustment for more informed patient details (e.g., disease severity
and history), besides solely age and sex, when predicting long-term survival. We
conducted a retrospective cohort study of patients admitted to hospital for
suspected acute myocardial infarction. Index scores were calculated by applying
the D'Hoore et al. algorithm (1993). The index significantly improved the model
fit (likelihood ratio test: p < 0.001). The D'Hoore-adapted Charlson index is a
useful comorbidity risk adjustment tool when applied to AMI and angina patients.
PMID- 10786064
TI - Modeling the recovery from depressive illness by an exponential model with mixed
effects.
AB - In clinical trials of antidepressant treatments, a depression rating score is
usually measured at several points of time for each patient. We propose an
approach to fit data from this type of clinical trial using an exponential mixed
effects model. Compared to previous proposals, this approach has the advantage
that individual recovery curves are fitted rather than curves of means.
Furthermore, no artificial fixing of model parameters is needed as in other
approaches. The flexibility of the proposed model is shown for various
situations. The approach is illustrated by an example from a placebo-controlled
study for the treatment of depression with St. John's Wort (Hypericum
perforatum).
PMID- 10786065
TI - Understanding terminological systems. I: Terminology and typology.
AB - Terminological systems are an important research issue within the field of
medical informatics. For precise understanding of existing terminological systems
a referential framework is needed that provides a uniform terminology and
typology of terminological systems themselves. In this article a uniform
terminology is described by putting relevant fundamental notions and definitions
used by standard organizations such as CEN and ISO into perspective, and
interrelating them to arrive at a useful typology of terminological systems. This
typology is illustrated by applying it to five well-known existing terminological
systems.
PMID- 10786066
TI - Understanding terminological systems. II: Experience with conceptual and formal
representation of structure.
AB - This article describes the application of two popular conceptual and formal
representation formalisms, as part of a framework for understanding
terminological systems. A precise understanding of the structure of a
terminological system is essential to assess existing terminological systems, to
recognize patterns in various systems and to build new terminological systems.
Our experience with the application of this framework to five well-known
terminological systems is described.
PMID- 10786067
TI - CISMeF: a structured health resource guide.
AB - In 1999, the Internet has become a major source of health information. The
objective of CISMeF is to catalogue and index the main French-speaking health
resources. In September 1999, the number of indexed resources totaled over 7,100
with a mean of 75 new sites per week. CISMeF uses two standard tools for
organizing information: the Medline bibliographic database MeSH thesaurus and the
Dublin Core metadata format. Resources included in CISMeF are described by the
following: title, author or creator, subject and keywords, description,
publisher, date, resource type, format, identifier, and language. To index
resources, CISMeF uses five levels of hierarchy: "meta-term", category, keyword,
subheading, and resource type. CISMeF contains a thematic index, including
medical specialities and an alphabetic index. CISMeF respects the Net Scoring,
criteria to assess the quality of health information on the Internet. The CISMeF
project offers a valuable tool for the French-speaking health community: 2,500
computer users visit the Web site each working day.
PMID- 10786068
TI - ARCHIMED: a Network of Integrated Information Systems.
AB - ARCHIMED is a Network of Integrated Information Systems (NIIS). This novel
concept of hospital information system has a major advantage over the currently
used distributed systems. The normalized representation structure of its
databases enable its Navigators to reach simultaneously not only the data coming
from different hospital departments, laboratories, and other hospital facilities,
but also the data from different hospitals associated in the network.
PMID- 10786069
TI - TANCLICO: tools for the analysis of inter-departmental clinical communications.
AB - Patient care management provided by healthcare organizations is complex,
involving many different care providers. The information exchange between
providers concerns a varying and considerable number of actors and a high
transmission load. Based on models, used to characterize specific features of
work processes, we propose a new method able to analyze and represent clinical
communications inside hospitals. Software has been developed, providing tools for
storing and retrieving information resulting from clinical communications. The
method, together with data collected in actual situations, may constitute useful
tools for health information systems developers.
PMID- 10786070
TI - Standard method for describing an electronic patient record template: application
of XML to share domain knowledge.
AB - A Template Definition Language (TDL) was developed to share knowledge of how to
construct an electronic patient record (EPR) template. Based on the extensible
markup language XML, TDL has been designed to be independent of EPR platforms or
databases. Our research of TDL was conducted through evaluation of the
description of various templates in the currently available EPRs and through
comparisons with some electronic clinical guidelines. We conclude that TDL is
sufficient for the objective but still needs improvement of the algorithm for
describing dynamic changes.
PMID- 10786071
TI - A process view of medical practice by modeling communicative acts.
AB - The need of an electronic patient record with a process view on medical care is
widely acknowledged. Characteristics of DEMO (Dynamic Essential Modeling of
Organizations) suggest that with this methodology an adequate process view of
medical practice can be obtained. In applying DEMO to the care process of the
emergency department at the University Medical Centre Utrecht, it was
investigated if DEMO fulfilled our expectations. This practical application
showed that DEMO yields an adequate process view by a clear and comprehensible
view of the core processes, responsibilities, co-ordination of activities, and a
clear description of causal and conditional relations between activities.
PMID- 10786072
TI - Requirements for speech recognition to support medical documentation.
AB - Recent advances in the development of automated speech recognition (ASR) have
made routine applications for medical documentation possible. To achieve this,
ASR has to be optimally integrated into the specific documentation scenario. The
classification presented in this paper allows the definition of specification
requirements. For two different documentation scenarios the appropriate product
selection has been done according to this classification. Two evaluation studies
are presented, addressing the usefulness of applying automated speech
recognition.
PMID- 10786073
TI - An end-to-end secure patient information access card system.
AB - The rapid development of the Internet and the increasing interest in Internet
based solutions has promoted the idea of creating Internet-based health
information applications. This will force a change in the role of IC cards in
healthcare card systems from a data carrier to an access key medium. At the
Medical Informatics Department of Kyoto University Hospital we are developing a
smart card patient information project where patient databases are accessed via
the Internet. Strong end-to-end data encryption is performed via Secure Socket
Layers, transparent to transmit patient information. The smart card is playing
the crucial role of access key to the database: user authentication is performed
internally without ever revealing the actual key. For easy acceptance by
healthcare professionals, the user interface is integrated as a plug-in for two
familiar Web browsers, Netscape Navigator and MS Internet Explorer.
PMID- 10786074
TI - A telemedicine management model based on message-trigger service.
AB - A telemedicine system model, based on a message-trigger service, is described.
This model distributes system applications on multiple computers and establishes
a communication platform to exchange messages among all applications. By
broadcasting event messages, an application is able to trigger a set of local and
remote services. At the same time, a protocol for message exchange is proposed to
fulfill cooperation of applications. To validate the model, a teleconsultation
system is designed. The results indicate that the model has good compatibility
and that the characteristics are easy to implement.
PMID- 10786075
TI - Intraindividual specificity and stability of human EEG: comparing a linear vs a
nonlinear approach.
AB - We have applied the so-called "unfolding dimension approach" to reanalyze an
earlier longitudinal EEG study. Both linear and nonlinear approaches show that
the EEG comprises a static, person-specific part upon which nonstatic and state
specific parts are superimposed. The intraindividual specificity and stability of
the genetic part are similar between methods. This is assessed by comparing the
outcome of a person to his own outcomes at later times (14 days and 5 years
later). The nonlinear method revealed a median correlation coefficient rho =
0.55, whereas advanced linear methods showed a median rho = 0.84. An apparent
effect for the 5-year interval was detected with the nonlinear method and is
discussed in terms of the different assumptions of the two approaches concerning
EEG signal generation.
PMID- 10786076
TI - Structured representation of drug indications: lexical and semantic analysis and
object-oriented modeling.
AB - No standardized representation of drug indications is currently available that
could be used in drug knowledge bases. We describe an object-oriented
representation of indications that should make it possible to develop new tools
for selecting drugs and checking prescriptions in computerized drug prescription
systems. The model was developed using the results of a lexical and semantic
analysis of drug indications, collected into a single file and processed using
natural language processing software. It distinguishes both the diseases for
which the drug may be given and the efficiency of the drug for a given
indication. Two aspects of the model were evaluated: the differences if two
independent evaluators filled the attributes independently and the loss of
information induced by the use of the model. A system based on this model, making
it possible for the physician to select all the drugs satisfying various
criteria, is also presented.
PMID- 10786077
TI - Evaluation of techniques for the presentation of laboratory data: support of
pattern recognition.
AB - Two tabular and two graphical techniques for the presentation of laboratory test
results were compared in a reaction-time experiment with 22 volunteers. The
experimental setup was designed to determine whether one or more of the
presentation techniques facilitated the recognition of four predefined
combinations of abnormal test results. Using a conventional, tabular presentation
technique as a reference, faster median response times were obtained with each of
the other three presentation techniques, irrespective of pattern. The effect on
accuracy was less clear, possibly due to the small number of errors made.
PMID- 10786078
TI - From a urinalysis strategy to an evaluated urine protein expert system.
AB - Urine single protein analysis has developed into a routine method for the
screening and monitoring of kidney diseases. In order to support clinical
decision making by an interpretative report, a urine protein expert system (UPES)
has been developed. Based on a database containing more than 500 excretion
patterns, a modular knowledge base was extracted in production rules and
implemented in a modern expert system shell. The resulting interpretation system
has been thoroughly verified and validated. After the need of interpretation of
the complex findings had been documented in a survey, its usability in routine
and its knowledge representation was evaluated in 11 hospitals. A user conference
confirmed a high quality level of the reports proposed by UPES. It revealed that
the problem of automatic data transfer as well as the common definition of
diagnostic terms by laboratorians and clinicians play a crucial role for the use
of knowledge-based systems in laboratory medicine.
PMID- 10786079
TI - [Keeping hay fever from turning into asthma. Stopping the allergy cascade].
PMID- 10786080
TI - [Bringing science and budget under one hat. Interview by Dr. Barbara Kreutzkamp].
PMID- 10786081
TI - [WHO warns about a change in approach. Long-term therapy for hay fever
patients?].
PMID- 10786082
TI - [With head and neck pain rather not consult a chiropractic?].
PMID- 10786083
TI - [Improved hormone implant provides 3 years of contraception. The end of the
pill?. Interview by Petra Eiden].
PMID- 10786084
TI - [Therapy of hypertension with calcium antagonists. Heart and kidney protection
for elderly type 2 diabetic patients].
PMID- 10786085
TI - [Early detection of prostate carcinoma. What diagnosis is of value when?].
AB - Early detection of carcinoma of the prostate is based on digital rectal
examination of the gland (DRE), transrectal ultrasonic exploration of the gland
(TRUS) and determination of the prostate specific antigen (PSA) in the serum. The
sensitivity of DRE along, but also in conjunction with TRUS is inadequate for
early detection. Furthermore, two-thirds of all palpable prostate carcinomas have
already breached the organ (T3), and are no longer curable by such local measures
as radical prostatectomy or radio-therapy. Nevertheless, DRE is mandatory, since,
when an induration is palpable, a prostate biopsy should be obtained even when
the PSA is normal (< 4 ng/ml). Imaging procedures, such as TRUS or endorectal NMR
have only a secondary role in early detection, while TRUS is indispensable for a
controlled biopsy of the prostate. The most important early detection measure is
the annual determination of PSA (syn. traditional or total PSA), during which
both bound and free PSA is determined using an immunoassay. A chronic problem
with the evaluation of serum levels of this organ marker - which is not an
antigen specific for prostate carcinoma - is the fact that although it has an
acceptable sensitivity (> 90%),its specificity is low (40% false positive
findings). Attempts have been made to reduce the rate of unnecessary biopsies by
measuring free PSA, PSA-density, age-corrected PSA or bound PSA. However, such
attempts have failed to improve the efficacy of traditional PSA measurement in
the individual case. In the guidelines relating to the diagnosis of prostate
carcinoma established by the German urologists, the present recommendation
requires PSA measurement once a year from the age of 45 onwards.
PMID- 10786087
TI - [Pain management in general practice. Therapy with nonsteroidal anti-inflammatory
drugs].
PMID- 10786086
TI - [Therapy of prostate carcinoma. Age, general health status and stage determine
choice of therapy].
AB - Radical prostatectomy is indicated in patients with an estimated life expectancy
of 10 years and with organ defined cancer disease (T1b-T2, No, Mo). Radiotherapy
is an effective alternative treatment, especially in patients with an increased
comorbidity. Primary hormonal treatment is not indicated for organ-defined
cancer. Prognosis of patients with locally advanced prostatic carcinoma
(T3,NO,MO) is poor because of micrometastases; tumour progression will occur in
75% of patients independent of local therapy. Orchiectomy or LH-RH treatment is
option of first choice in metastatic prostate cancer disease. There is no need
for complete androgen deprivation. Ongoing trials measure the effect of
intermittant androgen deprivation. Intention for treatment of hormone refractory
cancer is improvement of quality of life. Cancer-related symptoms are pain caused
by bone metastases, lymphoedemas and urinary retention. Therapeutic options are
monochemotherapy, hormonal treatment, analgetic treatment besides palliative
radiotherapy.
PMID- 10786088
TI - [Gastric protective pain therapy. What is the advantage of new COX-2
inhibitors?].
PMID- 10786089
TI - [Good therapy control requires a standardized test. Thrombosis ABC, 13: INR
instead of Quick].
PMID- 10786090
TI - [Renal failure in chronic osteomyelitis. Secondary amyloidosis in chronic
osteomyelitis].
PMID- 10786091
TI - [Why colleague Hansen is in despair over current politics. With us specialist
have too much to say. Interview by Werner Loosen].
PMID- 10786092
TI - [Model project will separate chaff from wheat. Phytopharmaceutical prescription-
without fear of censure].
PMID- 10786093
TI - [Depressed patients. Competent treatment by the general practitioner].
PMID- 10786094
TI - [Detlef Kellermann and his "hematoma" series. The long path to healing].
PMID- 10786095
TI - Neuropsychological changes after surgery for anterior communicating artery
aneurysm.
AB - Neuropsychological disturbances following surgery for anterior communicating
artery aneurysms were analyzed in 26 patients (11 males, 15 females) using the
Hasegawa dementia scale-revised (HDS-R) over a 3-year period. The patients were
aged from 34 to 76 years (mean 54.1 years). Lesions in the frontal lobe were
evaluated using computed tomography (CT). Twenty-three patients had symptoms over
the course. Four patients had basal forebrain lesion, five had ventral frontal
lesion, and 12 had no lesion. Patients with basal forebrain lesion and no lesion
tended to show disorientation. The mean HDS-R score was 10.2 points in the
patients with ventral frontal lesion, and 13.5 points in the patients with no
lesion. These scores are within the range for dementia. The mean HDS-R score in
patients with basal forebrain and striate lesions was over 25 points and beyond
the range for dementia. Significant differences were observed in the HDS-R score
between patients with ventral frontal lesion and basal forebrain lesion, and
between patients with no lesion and basal forebrain lesion (p < 0.05). Recovery
from neuropsychological disturbances was poorer in patients with ventral frontal
lesion and no lesion compared to those with basal forebrain and striate lesions,
and their symptoms tended to persist.
PMID- 10786096
TI - Long-term follow-up study of patients with cavernous sinus aneurysm treated by
proximal occlusion.
AB - Proximal occlusion of the internal carotid artery (ICA) is still the treatment of
choice for a large cavernous sinus aneurysm. Endovascular occlusion or trapping
of the ICA with or without an extracranial-intracranial bypass is sometimes
performed. We analyzed the results of the long-term follow up of 11 patients with
a giant or large cavernous sinus aneurysm treated by only proximal occlusion
between 1975 and 1989. Proximal occlusion of the carotid artery was performed by
Selverstone clamping. The follow-up period ranged from 6 to 21 years (mean 13.9
years). Eight of the 11 patients showed improvement of cranial nerves paresis or
headache, and four became asymptomatic. None of the original aneurysms ruptured.
The final outcomes were nine good recovery, one moderately disabled, and one
severely disabled by the Glasgow Outcome Scale. The causes of morbidity were
early ischemia and subarachnoid hemorrhage from a newly formed aneurysm. Late
complications included ischemia in two patients, and new formation and
enlargement of aneurysms at a site other than the original aneurysm in two
patients, 13 and 17 years later. Therapeutic carotid artery occlusion requires
strict test ICA occlusion. In addition, long-term follow up by periodical
cerebral angiography using magnetic resonance, computed tomography, or digital
subtraction angiography is necessary, and postoperative medical treatment is
important to reduce the risk of late complications.
PMID- 10786097
TI - Treatment of bacterial brain abscess by repeated aspiration--follow up by serial
computed tomography.
AB - Bacterial brain abscess often requires repeated aspiration before the abscess
finally resolves. However, there are no guidelines for treatment by aspiration;
for example, when should the abscess be tapped again, or when can an abscess be
treated by antibiotics alone without further aspiration. Eleven patients with
bacterial brain abscess treated by aspiration were evaluated to establish
treatment guidelines for brain abscess, in particular the abscess size on serial
computed tomography (CT) after aspiration. CT was performed about 24 hours after
aspiration to evaluate the size of the abscess, and almost weekly during follow
up. The diameter of the brain abscess before and after the initial and last
aspirations were reviewed. In eight of the 11 patients, abscesses were aspirated
repeatedly: two to three times in most patients. The diameter of the abscesses
was 2.5-4.5 cm (mean 3.5 cm) before the last aspiration, and 1.4-3.4 cm (mean 2.3
cm) after the last aspiration, or when continuous drainage was discontinued.
Perifocal edema was moderately decreased within 3 weeks after the last aspiration
by medical treatment alone, with a concomitant decrease in the volume of the
abscess. There were no deaths, and most patients had a favorable outcome. These
results suggest that after the diameter of the abscess becomes less than 2 to 3
cm and does not increase anymore on serial CT, medical treatment alone can be
anticipated to give satisfactory results without further aspiration.
PMID- 10786098
TI - Chronic, traumatic intraconal hematic cyst of the orbit removed through the
fronto-orbital approach--case report.
AB - A 22-year-old male presented with a chronic encapsulated intraorbital hematoma 3
months after blunt trauma to his left eyeball. Ophthalmological examination found
the best corrected visual acuity was 4/20 in the left eye, and 20/20 in the right
eye. The orbit exhibited exophthalmus and inability of the eye to move above the
horizontal level. Orbital magnetic resonance imaging showed a fairly well
demarcated area in the medial aspect of the orbit appearing as hyperintense on T1
weighted images and isoto hyperintense on T2-weighted images. This area was
believed to be hemorrhage. No other abnormalities were found. The diagnosis was
hematic cyst. The cyst was approached through a left fronto-orbital route and its
location identified within the periorbita and orbital fat. The cyst was removed
partially. Histological examination demonstrated cystic accumulation of blood and
breakdown products in a non-epithelium-lined fibrous capsule, compatible with
hematic cyst. The presence of hemosiderin in the cyst wall suggested that the
cyst was a chronically enlarging lesion. Hematic cysts of the orbit usually
present as subperiosteal mass months to years after trauma. Surgical removal of
the cyst wall rather than needle aspiration is recommended to prevent recurrence.
PMID- 10786099
TI - Magnetic resonance imaging of calvarial eosinophilic granuloma with pericranial
soft tissue reaction--case report.
AB - A 4-year-old girl presented with an eosinophilic granuloma in the cranial vault.
Magnetic resonance (MR) imaging showed the mass as slightly low intensity on T1-
and high intensity on T2-weighted images. The pericranial soft tissue was densely
enhanced after gadolinium-diethylenetriaminepenta-acetic acid infusion. The mass
was soft and successfully removed. Histological examination disclosed Langerhans'
cell histiocytosis. MR imaging is useful for the diagnosis of calvarial
eosinophilic granuloma with soft tissue involvement.
PMID- 10786100
TI - Complications associated with intraarterial administration of papaverine for
vasospasm following subarachnoid hemorrhage--two case reports.
AB - Complications associated with intraarterial papaverine infusion occurred in two
patients treated for vasospasm due to subarachnoid hemorrhage (SAH). A 42-year
old male with an anterior communicating artery aneurysm underwent craniotomy and
aneurysm clipping. Five days after the SAH occurred, angiography demonstrated
moderate vasospasm in spite of hypervolemic-hypertensive therapy. During
papaverine infusion into the carotid artery, he suffered loss of consciousness
due to a seizure for a few minutes. A 61-year-old female with a right internal
carotid-posterior communicating artery aneurysm underwent clipping. Six days
after the SAH occurred, angiography demonstrated severe vasospasm in spite of
hypervolemic-hypertensive therapy. Angiography performed immediately after
papaverine infusion into the carotid artery revealed exacerbation of the
vasospasm. Finally she suffered cerebral infarction and died. Complications of
intraarterial papaverine infusion are potentially dangerous. We recommend trial
administration of papaverine with angiography and neurological examination before
full dose infusion to avoid complications.
PMID- 10786101
TI - Malignant schwannoma metastasizing to the parenchyma of the brain--case report.
AB - A 48-year-old male presented with a very rare case of malignant schwannoma
metastasizing to the parenchyma of the brain. He had undergone previous radical
surgical resection of an abdominal wall tumor that was histologically confirmed
as a malignant schwannoma. Five years later, the patient presented with
metastases to the parenchyma of the brain and lung. A large mass at the left
frontoparietal region was totally resected immediately after intratumoral
hemorrhage. He recovered well and the lung metastasis was also removed, but he
later developed further multiple metastases in the lung and brain.
PMID- 10786102
TI - Toxoplasmic encephalitis in patients with acquired immunodeficiency syndrome-
four case reports.
AB - Four patients, all males aged 40-64 years, presented with toxoplasmic
encephalitis associated with human immunodeficiency virus (HIV) infection
manifesting as nonspecific neurological deficits such as epilepsy or hemiparesis.
Magnetic resonance imaging showed single or multiple lesions with ring
enhancement, mimicking metastatic brain tumor or brain abscess. Marked
eosinophilia was noted in three patients. Two patients who received anti
toxoplasma chemotherapy in the early stage had a good outcome. However, the other
two patients suffered rapid neurological deterioration and needed decompressive
surgery, resulting in a poor outcome. Toxoplasma diffusely infects the whole
central nervous system from the early stage. The outcome for patients who needed
emergency surgery was poor. Therefore, this rare but increasingly common
infectious disease must be considered in the differential diagnosis of a patient
with neuroimaging findings similar to those of metastatic tumor or brain abscess.
Appropriate chemotherapy should be started immediately after HIV-positive
reaction is identified in patients with single or multiple mass lesions with ring
enhancement.
PMID- 10786103
TI - Trigeminal neuralgia associated with tentorial agenesis and temporal lobe
herniation--case report.
AB - A 22-year-old female presented with an extremely rare case of trigeminal
neuralgia associated with tentorial agenesis. The pulsating pain in her left
maxillary region persisted for an abnormally long time and had no trigger zone.
The pain later spread to the periorbital region. Coronal magnetic resonance
imaging revealed left medial temporal lobe herniation caused by tentorial
agenesis. The herniated temporal lobe, which had distorted the superior
cerebellar artery, was causing compression of the trigeminal nerve. Her condition
improved following microvascular decompression surgery. Tentorial agenesis should
be considered as a cause of atypical pulsating facial pain, especially in younger
patients.
PMID- 10786104
TI - Revised new brain retractor: characteristics and new indications--technical note.
AB - Revisions were made to our new brain retractor with respect as follows. A knob
was added to each shaft of the new brain retractor to facilitate handling. The
angle between the shaft and the blade can now be adjusted from 60 to 135 degrees,
which is useful in deep, narrow operative fields. Three blade lengths (20, 30,
and 40 mm) are now available. The new retractor is entirely made from titanium.
This revised brain retractor is very useful for the dissection of sylvian and
interhemispheric arachnoid membranes, as well as in the extirpation of
intracerebral masses via corticotomy.
PMID- 10786105
TI - Spontaneous hemopneumothorax--results of conservative treatment.
AB - Spontaneous hemopneumothorax is a serious condition complicating spontaneous
pneumothorax. Early stage thoracotomy has been advocated to stop the bleeding and
evacuate the coagulated blood from the pleural cavity. The present review was
undertaken to emphasize the potential life-threatening condition of spontaneous
hemopneumothorax and reassess the benefit of conservative treatment with chest
tube drainage. Out of six patients, five patients were treated conservatively and
one required an emergency thoracotomy because of cardiovascular collapse.
Although three patients still had minimal residual hemopneumothorax on discharge,
none of them developed empyema or trapped lung. In conclusion, conservative
treatment is efficient and should be performed if bleeding persists for less than
24 hours after chest tube placement.
PMID- 10786106
TI - [Laser transmyocardial revascularization--a potential risk in an acute
situation?].
AB - Morphological and functional effects of transmyocardial laser revascularization
(TMLR) are analyzed in an acute setting on a porcine model. Ten channels were
drilled in the left lateral wall of the heart of 15 pigs (mean weight, 73 +/- 4
kg) with a Holmium-YAG laser (wavelength: 2.1 mu, probe diameter: 1.75 mm).
Echocardiographic control was performed before the TMLR procedure as well as 5
min and 30 min thereafter. Echocardiographic parameters were recorded in short
axis at the level of the laser channels, and included left ventricular ejection
fraction, fractional shortening and segmental wall motility of the channels' area
(scale 0-3: 0 = normal, 1 = hypokinesia, 2 = akinesia, 3 = dyskinesia). After
sacrifice the lased region was sliced perpendicularly to the channels for
histological and morphometrical analysis. Five minutes after the drilling of the
channels, all the echocardiographic index worsened significantly in comparison
with baseline values (p < 0.01). All recovered after 30 min and showed no
difference with baseline values. Cross-section of the channel lesions measured
8.8 +/- 2.4 mm2 which is more than three times that of the probe (p < 0.01). In
acute conditions, the lesions due to the TMLR probe are significantly larger than
the probe itself and cause a transient drop of the segmental wall motility on a
healthy myocardium. These results suggest that TMLR should be used cautiously in
the clinical setting for patients with an impaired ventricular function.
PMID- 10786107
TI - [Harvesting the vena saphena magna for aortocoronary bypass operations--is the
subcutaneous suture necessary?].
AB - BACKGROUND: The need for stitching the subcutaneous layers after saphenous vein
graft harvest for coronary artery bypass is discussed controversially. METHODS:
We conducted a prospective study to determine whether subcutaneous stitches
reduce the incidence of hematoma, infection and wound dehiscence after saphenous
vein graft harvest in patients undergoing coronary artery bypass grafting.
Patients were randomized either to group 1 (n = 100, subcutaneous suture) or
group 2 (n = 46, without subcutaneous suture). Leg wounds were examined for
hematoma, wound dehiscence, necrosis or secretion preoperatively and on day 2 and
5 after surgery. Furthermore, leg circumferences were measured at distinct areas.
RESULTS: There were no significant differences in the incidence of wound
complications. Especially, leg circumferences and incidence of hematomas (group
1: 36% versus group 2: 39%) as well as the length of hospital stay (group 1: 6.8
days versus group 2: 6.2 days) did not differ significantly. CONCLUSIONS: The
subcutaneous suture following saphenectomy is unnecessary. A deterimental effect
of an additional subcutaneous suture could not be demonstrated.
PMID- 10786108
TI - Anastomotic longitudinal stress due to modification of arterial longitudinal
properties after anastomosis.
AB - BACKGROUND: In our hands, in vivo segmental vessel length changes up to 5%
because of blood pressure: increasing in arterial pressure is associated to
decrease in segmental vessel length. METHODS AND MATERIAL: Using two
piezoelectric crystals sutured on vessel wall and a high fidelity pressure probe,
we recorded artery length variations as function of blood pressure, before and
after an end-to-end anastomosis on four pigs carotid arteries. RESULTS: Mean
arterial pressure before anastomosis = 73 mmHg (+/- 12); mean arterial pressure
after anastomosis = 91 mmHg (+/- 14); mean crystals displacement before
anastomosis during systole = -0.21 mm; mean crystals displacement after
anastomosis during systole = +0.24 mm; mean distance between crystals before
anastomosis = 12.3 mm (+/- 0.8) and after anastomosis = 11.2 mm (+/- 0.5).
CONCLUSIONS: In the acute phase following an end-to-end anastomosis, an increase
in blood pressure causes increasing in vessel length, with an exponential
correlation. The anastomosis is constantly subjected to a longitudinal traction
whose magnitude depends on blood pressure.
PMID- 10786109
TI - Decreased compliance on arterial anastomoses.
AB - The present study was undertaken to examine the cross-sectional vascular
compliance at the anastomotic site. METHODS AND MATERIAL: We performed end-to-end
anastomosis on the carotid artery of six pigs using continuous 6/0 polypropylene.
Four carotid arteries were excised and mounted in a perfusion chamber while the
remaining two were left in living animals. We used pulsed ultrasound (NIUS 02) to
generate detailed longitudinal profiles of diameter and compliance in the
proximity and on the anastomosis. RESULTS: On the anastomosis, the vessel
diameter decreases (-1 to -2.6% of diastolic diameter) when blood pressure
increases with an exponential correlation (R2 = 0.75). The arterial compliance at
the anastomosis was negative: the vessel cross-section reduction for a pulse
pressure of 1 up to 32 mmHg was 0.9 to 2% of diastolic vessel cross-section.
CONCLUSIONS: Vessel movement generated a dynamic stenosis whose magnitude seems
to depend on blood pressure level. Increasing blood pressure causes the
retraction of vessel ends which causes vessel lumen reduction. These results
suggest that continuous suture does not provide the continuity of mechanical
properties of the artery.
PMID- 10786110
TI - [Endothelial lesions caused by intra-aortic counterpulsation balloons].
AB - Intra-aortic balloon pump (IABP) is the most frequently used mechanical
circulatory support. Repeated trauma on the aortic wall has been reported as a
cause of balloon perforation by endothelial denudation of atheromatous plaque.
This study analyses the effect of IABP on the endothelium of the calf aorta. In
12 calves (mean weight: 72 +/- 6 kg) an IABP was inserted by femoral route and
left during 6 hours on internal mode with a frequency of 80 cycles/min. The
animals were sacrificed after the procedure (n = 4), at postoperative day (POD) 7
(n = 4), and at POD 14 (n = 4). In the aorta facing the balloon, nine transmural
samples were taken proximally (n = 3), at mid height (n = 3) and distally (n =
3), for histological analysis of the percentage of aortic surface covered with
endothelium. The percentage of aortic surface covered with endothelium at POD 0,
7 and 14 was proximally: 72.5 +/- 27.5%, 83.7 +/- 16.9% and 93.3 +/- 8.9%
respectively; at mid-height: 50.8 +/- 30.7%, 65 +/- 25% and 95 +/- 5%; and
distally: 31.4 +/- 20.1%, 48.3 +/- 34.4% and 85 +/- 10%. A large portion of the
aortic endothelium is abraded after 6 hours of IAB pumping. This effect is more
important at the distal level of the aorta. After two weeks, most of the
endothelium has regenerated.
PMID- 10786111
TI - [Management concept for acute traumatic aortic rupture based on a case report].
AB - Acute traumatic rupture of the thoracic aorta (ATRRA) is mainly a consequence of
high-speed travel or fall from great altitude. Most of the victims die at the
accident scene. Only 10-20% reach the hospital alive. Because of the extremely
high mortality, emergency repair seems to be indicated. Taking into consideration
that the hemorrhage into the mediastinum may remain constained and the patient
usually suffers from a wide variety of life-threatening causes of injury the
aforementioned option is probably not the best one. We report on a patient whose
"stable" aortic rupture was surgically corrected after stablization of the
circulation, coagulation and respiratory problems.
PMID- 10786112
TI - [Surgical repair of aortic coarctation in adults over 30 years of age].
AB - Coarctation of the aorta is nowadays rarely observed among adult population, as
it is usually detected and treated during infancy. The natural history of this
disease however is known to lead to early death due to the consequences of severe
arterial hypertension. We report on 3 patients older than 30 years, recently
operated on in our cardiosurgical units. Two of them were foreigners recently
arrived in Switzerland, of 46 and 32 years old respectively. The medical
examination highlighted severe hypertension and bilateral absence of femoral
pulses. The third patient was a Swiss citizen and had a similar examination.
Chest X-rays clearly showed rib notching, and the suspected diagnosis was
confirmed with angiography. Three different surgical techniques were chosen,
according to the peroperative situation. In one case, the stenosis was resected
and an end-to-end anastomosis could be performed. In another case, the occlusion
was complete and extended over 3 centimeters. The resected segment was replaced
by a prosthetic graft. In the third case, we performed a synthetic patch graft
aortoplasty. Postoperative care were simple in every cases. Coarctation of the
aorta must be evoked among the possible etiologies of severe hypertension, as the
surgical treatment is of real benefit and with reduced morbidity.
PMID- 10786113
TI - Parental notification article criticized.
PMID- 10786114
TI - Loving alcoholics.
PMID- 10786115
TI - Importance of good habits.
PMID- 10786116
TI - Another "Blues" alert.
PMID- 10786117
TI - It is worth the effort.
PMID- 10786118
TI - MedBytes.
PMID- 10786119
TI - Interim overload.
PMID- 10786120
TI - Not for sale.
PMID- 10786122
TI - Getting paid.
PMID- 10786121
TI - Battling supergerms.
PMID- 10786123
TI - Avoiding the legal pitfalls in mental health commitments.
AB - Treatment for some patients with mental illness involves involuntary commitment
to a mental hospital. The Texas Mental Health Code establishes legal criteria,
procedures that must be followed, and the burden of proof borne by the State of
Texas to obtain a commitment. The legal provisions protect patients from
inappropriate hospitalization but often obstruct the efforts of physicians to
effectively treat patients with mental illness. By understanding what appear to
be barriers to treatment, doctors can avoid the legal pitfalls that prevent
involuntary treatment when indicated.
PMID- 10786125
TI - Tropical disease research
PMID- 10786124
TI - HIV/AIDS situation, WHO Western Pacific region, 1998.
PMID- 10786126
TI - Effect of cooling condition on leucite crystals in dental porcelains.
AB - X-ray diffractometry (XRD) was used to analyze the crystal phases of three
commercial dentin and incisal porcelains prepared by normal cooling, quenching in
water, and controlled slow annealing after normal firing. There were no
remarkable differences in the contents of either tetragonal and cubic leucite in
the fired porcelain discs prepared under the three cooling conditions.
Furthermore, there were no significant differences in the parameters of the a
axis and c-axis of tetragonal leucite, and the a-axis of cubic leucite among
them. These results suggest that the cooling condition has little effect on the
microstructural changes of leucite crystals in the dental porcelains, since the
leucite crystals were formed at a higher temperature range than the firing- and
cooling-temperature range and were stabilized by incorporation of additives into
the lattice.
PMID- 10786127
TI - Development of metal-resin composite restorative material. Part 2. Effects of
acid and heat treatments of silver-tin filler particles on flexural properties of
metal-resin composite.
AB - The effects of acid and heat treatments of silver-tin filler particles on the
flexural properties of metal-resin composite restorative materials were
investigated. Five metal-resin composite restorative materials containing
different silver-tin filler particles treated under different conditions were
experimentally prepared. The conditions of the alloy particles were; 1) as
atomized (NT), 2) 1.8% HCl acid-treated (AT), 3) heat-treated at 150 degrees C
for 5 min after AT (A15), 4) heat-treated at 200 degrees C for 5 min after AT
(A20) and 5) heat-treated at 250 degrees C for 5 min after AT (A25). The flexural
strength and the flexural modulus of elasticity were measured for the five metal
resin composites to evaluate the effects of the acid and heat treatments. The
flexural strength of the prepared composites was significantly influenced by the
surface condition of the filler particles (p < 0.01), and increased significantly
when the as atomized particles (NT) were acid-treated (AT) or acid- and heat
treated at 150 degrees C (A15), but then significantly decreased as the heat
treatment temperature increased (A20 and A25). The strength of the A15 composite
was significantly higher than those of the other composites, and exceeded that
(about 60 MPa) of the previous composite with no treatment. No significant
difference was found in the flexural modulus of the composites.
PMID- 10786128
TI - Structure of bioactive glass and its application to glass ionomer cement.
AB - We prepared a new glass ionomer cement using bioactive CaO-P2O5-SiO2(-MgO) glass
and investigated its setting process using FT-IR and MAS NMR analyses. The
compressive strengths of the cements depended on the glass composition and a
maximum strength of 33.3 +/- 4.7 MPa was obtained using cement with the glass
composition of MgO:4.6, CaO:44.9, SiO2:34.2 and P2O5:16.3% in weight. FT-IR
analysis showed that the COOH group in the polyacrylic acid decreased and
carboxylate ion (COO-Ca2+) increased after the setting reaction. A broad signal
appeared around -82 ppm in 29Si MAS-NMR spectra of the glass and a new signal
corresponding to hydrated silica gel formation appeared around -102 and -111 ppm
after setting. This suggests that Ca2+ was released from the glass powder to form
carboxylate salt and that a degree of polymerization in the silicate network
increased. The setting mechanism of the cement was found to be essentially the
same as in conventional glass ionomer cement.
PMID- 10786129
TI - Temperature-dependence of the mechanical properties of FRP orthodontic wire.
AB - The temperature-dependence of the mechanical properties of a new esthetic
orthodontic wire with fiber-reinforced plastic (FRP) structure was investigated.
The new FRP wire, fabricated by a hot drawing method, is 0.5 mm in diameter and
has a multiple fiber structure composed of biocompatible CaO-P2O5-SiO2-Al2O3
glass fibers of 20 microns in diameter and a polymethyl methacrylate matrix. The
flexural load at a deflection of 1 mm and Young's modulus at 24, 37, and 50
degrees C under wet conditions showed similar fiber fraction dependence to those
under dry conditions for a fiber fraction of 40-51%. The flexural load and
Young's modulus tended to decrease slightly with increases in temperature. This
tendency was larger for the lower fiber fraction. However, the difference in
flexural load for a temperature difference of between 24 degrees C and 50 degrees
C was at most 10 gf. This is negligibly small, and a constant orthodontic force
regarding temperature change would be advantageous from a clinical point of view.
PMID- 10786130
TI - Evaluation of the amount of residual monomer on UDMA-based resins by FTIR.
AB - The purpose of this study was to establish a method using FTIR to evaluate the
polymerization characteristics of UDMA-based resins. Three kinds of experimental
UDMA-based resins were prepared with various molar fractions. IR spectra of the
cured film specimens were measured with FTIR before and after extracting residual
monomer from each specimen by MeOH. From the IR spectra, the changes in the
number of double bonds were measured, with the NH absorbance peak as an internal
standard, and the amounts of residual monomers (RM) were calculated. The MeOH
immersed specimens were analyzed by HPLC. The RM measured by FTIR were compared
with those measured by HPLC. The RM measured by HPLC were more than those by
FTIR. Since these differences could be due to the difference in the area
measured, this FTIR estimation method of residual monomers in cured resins using
the NH absorbance peak as an internal standard could be an appropriate method
when the resin monomer does not contain aromatic compounds.
PMID- 10786131
TI - Effect of ferric chloride/citric acid/phosphoric acid conditioner on adhesion of
4-META/MMA-TBB resin to the tooth.
AB - The aim of this study was to examine the effects of ferric chloride/citric
acid/phosphoric acid conditioners on the surface morphology of enamel and dentin
and on the adhesion of 4-META/MMA-TBB resin to conditioned tooth surfaces. Seven
conditioners, including phosphoric acid and its mixture with citric acid and
ferric chloride, were prepared and used for treating bovine teeth before bonding
with the resin. The effects of the conditioners on the surface morphology and
adhesion were examined by scanning electron microscopy and by atomic force
microscopy and by tensile bond strength tests, respectively. The maximum bond
strengths to tooth surfaces were obtained by using 3% ferric chloride/5% citric
acid/10% phosphoric acid conditioner. Thus, enamel and dentin can be treated
simultaneously with this conditioner before bonding with the 4-META/MMA-TBB resin
system.
PMID- 10786132
TI - A method of predicting color stability of autopolymerizing acrylic resins using
electron spin resonance.
AB - Synopsis. Long periods can be required to determine the color stability of
acrylic resins. The concentration of propagating radicals with unpigmented
experimental resins (UER) and initiator solution (IS) of two initiator systems
(binary and ternary) and five products were measured using electron spin
resonance (ESR). The radical concentration was estimated from the area under the
integrated ESR spectrum. The discoloration was measured using a color computer.
Higher content of benzoylperoxide led to higher radical concentrations. The
radical concentration for the ternary system increased slightly with time, but
were lower than those of the binary system. Significant positive correlations
were found between the radical concentration and delta E*ab for UER (r = 0.900, p
< 0.01), IS (r = 0.953, p < 0.001) and the products (r = 0.808, p < 0.05). It was
suggested that the color stability of these resins was predictable by measuring
the radical concentration using ESR.
PMID- 10786133
TI - Phase transformations and age-hardening behaviors related to Au3Cu in Au-Cu-Pd
alloys.
AB - Phase transformation behaviors in Au-Cu-Pd alloys were investigated by means of
electrical resistivity measurements, hardness tests, X-ray diffraction and
transmission electron microscopy. Anisothermal and isothermal annealing were
performed. Two types of phase transformations were found, namely related to the
single phase of Au3Cu and the coexistent phase of Au3Cu and AuCu I. The latter
produced more remarkable hardening than the former. Hardening was brought about
by the antiphase domain size effect of Au3Cu ordered phase in the single phase
and by the formation of AuCu I ordered phase in the Au3Cu ordered matrix. There
are three modes of phase transformation in the coexistent region depending on the
composition. Each sequence is discussed.
PMID- 10786134
TI - Phase transformation mechanisms in (AuCu)1-xPdx pseudobinary alloys by direct
aging method.
AB - Phase transformation mechanisms in the AuCu-Pd pseudobinary system were studied
by means of electrical resistivity measurements, hardness tests, X-ray
diffraction and transmission electron microscopy. A direct aging method was
employed to eliminate the otherwise unavoidable ordering that takes place rapidly
during quenching into ice brine, hence it is important to distinguish the
ordering processes with and without an incubation period. Three phase
transformation modes occurred, namely; ordering at grain boundaries and in the
grain interior with nucleation and growth mechanism after incubation, and
spinodal ordering without any incubation period. The age-hardening of the alloys
examined was attributed to AuCu I ordering. Nucleation and growth mechanism
followed by twinning occurred in the specimens aged at higher temperatures, while
spinodal ordering was seen in specimens aged in lower temperature. The spinodal
ordering temperature of AuCu-Pd alloys increased according to Pd content.
PMID- 10786135
TI - Resin content in cement liquids of resin-modified glass ionomers.
AB - Qualitative and quantitative analyses were conducted on four kinds of resin
modified glass ionomer (RMGI) cement liquids, LC, LC II, LC III (hereinafter
referred to as LCs) and VM, using HPLC and laser Raman spectroscopic methods.
HPLC revealed that among the RMGI liquids LCs contain 31-32% HEMA (2-Hydroxyethyl
methacrylate), and VM contains 18% of the same. The composition of RMGI cement
liquids varied significantly between manufacturers. In Raman spectroscopic
analyses, the spectra of liquids of various ratios of polyacrylic acid and HEMA
were measured, and calculations were made on the peak intensity ratios of C=C
stretch vibration to C=O stretch vibration, common in both HEMA and polyacrylic
acid. The composition ratio of polycarboxylic acid to HEMA of commercial glass
ionomer cements was assessed by the regression curve generated by a combination
of peak intensity ratios and composition ratios. In addition, Raman spectroscopy
was able to identity the differences in form of the methacryloyloxy group.
PMID- 10786137
TI - Cytotoxicity of a trial resin composite liner containing TiK2F6 on rat dental
pulp cells.
AB - The aim of this study was to assess the toxicological responses of a resin
composite containing TiK2F6 and NaF in rat dental pulp cells. Trial resin
composite liners were made, containing 3 wt% fluorides (TiK2F6 or NaF). These
specimens were immersed in 5 ml of cell culture medium supplemented at 37 degrees
C for 24 hours. The eluates were used for the experiments. We judged the
cytotoxicity of the samples by the cell viability. The original elute solution
was serially diluted and then the medium was exchanged for the dilute medium. The
cell viability at 1, 2 or 5 days after commencement of re-culturing was
calculated. The viability of cells in the eluate from the resin composite liners
containing TiK2F6 and NaF decreased with time. The cytotoxicity of TiK2F6 was
weaker than that of NaF at all times.
PMID- 10786136
TI - Hydrothermal-electrochemical deposition of calcium phosphates on various metals.
AB - Calcium phosphates were formed on five kinds of substrate metals using a
hydrothermal-electrochemical method in an autoclave with two electrodes. The
electrolyte dissolving NaCl, K2HPO4, CaCl2.2H2O, tris (hydroxymethyl)
aminomethane, and hydrochloric acid was maintained at 100 degrees C, 150 degrees
C and 200 degrees C. The counter electrode, the anode, was platinum plate, 20 x
20 x 0.5 mm, and the working electrodes as cathode were pure titanium, pure zinc,
pure nickel, pure iron, and stainless steel plates. A constant direct current at
12.5 mA/cm2 was loaded for 1 hr. Hydroxyapatite [Ca10(PO4)6(OH)2] only deposited
at three temperatures on pure titanium plate. On pure zinc plate, both
parascholzite [CaZn2(PO4)2.2H2O] and hydroxyapatite were formed at 150 degrees C
and both parascholzite and ZnO were formed at 200 degrees C. Both hydroxyapatite
and beta-TCP [beta-Ca3(PO4)2] were formed on pure nickel, pure iron, and
stainless steel plates at 200 degrees C. It seems that the incorporation of the
metal ions released from the electrode decreased the Ca/P ratio of the deposit
due to the formation of other compounds except hydroxyapatite.
PMID- 10786138
TI - Metal-resin composite restorative material using powder-liquid system.
AB - In order to further improve the mechanical properties of a metal-resin composite
and avoid the problems which were found in the previous metal-resin composite
using a 2-paste system, another type of metal-resin composite using a powder
liquid system was developed. In the new system 4-META treatment was carried out
at low temperature and DMPT was separated from the 4-META treated particles. The
efficacy of this system as well as the effects of 4-META concentration, duration
of 4-META treatment (immersion time) and filler content on the flexural
properties, working time and setting time were investigated. The flexural
strength of the powder-liquid composite was significantly affected by two main
factors, immersion time and filler content, and the other properties (flexural
modulus, working time and setting time) were by all three main factors. The
highest flexural strength of the prepared composite was 91.8 MPa, which was
higher than that of the 2-paste composite (64.0 MPa) by about 43%. This was
achieved at a 0.1 ratio of 4-META concentration, 30 s immersion time and 94 mass%
filler content. The working time and setting time ranged between 2.3-13.6 min and
4.2-20.1 min, respectively, and those of the highest strength composite were 3.0
and 5.2, respectively. The results of the present study indicate that the powder
liquid system is effective to improve the properties of the metal-resin
composite.
PMID- 10786139
TI - Effect of cavosurface angle on dentin cavity adaptation of resin composites.
AB - The effect of the cavosurface angle of dentin cavities prepared in extracted
human molars on the cavity adaptation of a resin composite was evaluated by
measuring the gap width between the resin composite and the dentin cavity wall.
Cavities with cavosurface angles of 90 degrees, 120 degrees, 135 degrees, or 150
degrees were pretreated with one of two commercial dentin bonding systems or an
experimental dentin bonding system. The contraction gap width was measured at
both the cavity margin and the section cavity using a light microscope. Complete
cavity adaptation was obtained with pretreatment of the experimental groups
regardless of the cavosurface angle. The contraction gap observed at the cavity
margin was prevented with the two commercial dentin bonding systems when the
cavosurface angle was increased to 150 degrees. A high correlation was observed
between the contraction gap width and the proportion of the free surface to the
adhesive surface of the resin composite restoration.
PMID- 10786140
TI - Reinforcement mechanism of dentin mechanical properties by intracanal
medicaments.
AB - The reinforcement mechanism of dentin mechanical properties by intracanal
medicaments was investigated. The dumbbell-shaped specimens were prepared from a
collagen sheet, demineralized dentin and organic dissolved dentin. After
immersing the specimens in intracanal medicaments (eugenol and formocresol), the
tensile test was carried out in 37 degrees C water and the Vickers hardness test
was performed. The tensile strengths increased after eugenol and formocresol
immersion, especially collagen and organic dissolved dentin after formocresol
immersion and demineralized dentin after eugenol immersion. Thus, formocresol
immersion might have reinforced the dentin tensile strength by protein
coagulation, while eugenol immersion might have reinforced the dentin tensile
strength by not only protein coagulation but also chelation with hydroxyapatite.
However, the hardness values did not significantly change after intracanal
medicament immersion.
PMID- 10786141
TI - Isothermal age-hardening behaviour in a multi-purpose dental casting gold alloy.
AB - The isothermal age-hardening behaviour of a multi-purpose dental casting gold
alloy was investigated by means of hardness testing, X-ray diffraction study,
scanning electron microscopic observations and energy dispersive spectroscopy. By
ageing of the solution-treated specimen at 400-500 degrees C, two phases of the
Au-rich alpha 1 phase with an f.c.c. structure and the alpha 2 phase with an
ordered f.c.c. structure based on Pt3In were transformed into three phases of the
alpha 1 phase, the alpha 2 phase and the beta phase with an ordered f.c.t.
structure based on PtZn. Hardening was attributed to the fine nodular
precipitation resulting from the formation of the beta phase in the alpha 1
matrix. Softening was due to the coarsening of the fine nodular precipitates as
the result of consumption of the alpha 2 phase.
PMID- 10786142
TI - Effectiveness of the addition of water-soluble photoinitiator into the self
etching primers on the adhesion of a resin composite to polished dentin and
enamel.
AB - The effectiveness of the addition of a photoinitiator into self-etching primer
was investigated by measuring the tensile bond strength between a resin composite
and dentin or enamel. The addition of camphorquinone to 5 M (5 wt% MDP -35 wt%
HEMA aqueous solution) or 30 M (30 wt% MDP -35 wt% HEMA aqueous solution) did not
increase the bond strengths of resin composite to dentin or enamel. On the other
hand, the bond strength to dentin was increased by the addition of a water
soluble photoinitiator, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)
N,N, N-trimethyl-1- propanaminium chloride (QTX) to 5 M or 30 M. The bond
strengths to enamel were not influenced by the addition of QTX to 5 M or 30 M.
PMID- 10786143
TI - Development of metal-resin composite restorative materia. Part 1. Experimental
composite using silver-tin alloy as filler and 4-META as coupling agent.
AB - Metal-resin composites, using metal particles instead of inorganic particles as
the filler and 4-META as the coupling agent, were experimentally prepared under
20 different conditions (five different concentrations of 4-META, and four
different contents of metal particles). The flexural strength of the prepared
metal-resin composites was in the range of about 14.5-61.3 MPa. The flexural
strength was significantly influenced by the 4-META concentration, the metal
particle content and their interaction. The highest strength was estimated at 2-3
mass% of 4-META concentration and 92.0-93.5 mass% metal filler content. The
flexural modulus of the metal resin composite ranged approximately from 7.8 GPa
to 15.5 GPa. The flexural modulus of the metal resin composite significantly
increased with the metal particle content. The effect of the 4-META concentration
on the flexural modulus was not significant.
PMID- 10786144
TI - Correlation of dentin bond durability with water absorption of bonding layer.
AB - In order to understand the relationship between the durability of adhesive
strength in the oral cavity and water absorption, a series of O-methacryloyl-N
acyl tyrosines (MAATY)-2-hydroxyethyl methacrylate (HEMA) bond system samples was
prepared and their bonding strength to unetched human dentin was measured as a
function of immersion period in water. Also, bulk polymerization was carried out
to measure the amount of water absorption as a function of time. All specimens
absorbed water suddenly when they were immersed into water. The amount of
absorbed water was large when the carbon number in the acyl group was small or
the number of carboxylic groups was large. The adhesive strength of the MAATY
HEMA system to unetched dentin decreased significantly when the MAATY-HEMA
absorbed a larger amount of water. We concluded, therefore, that preparation of
MAATY which absorbs less water may improve durability even when immersed in
water.
PMID- 10786145
TI - The influence of configuration factors on cavity adaptation in compomer
restorations.
AB - The effect of configuration factor (C-factor) on cavity adaptation was
investigated in three compomer and one resin composite restorations. Eighty-four
cylindrical dentin cavities (C-factor: approximately 2.5, 3.0 or 4.0) prepared on
flat coronal dentin surfaces were filled with the materials in combination with
their proprietary adhesive systems. Cavity adaptation was microscopically
examined after 15 minutes storage in water at the top surface and at other four
sites along the cavity walls. Additionally, indentation testing was performed for
each material at 20 minutes and 24 hours after irradiation. Regression analysis
revealed no relationship between C-factor and gap dimension in compomer
restorations at any of the measuring sites, while a logarithmic relation was
found only at the cavity floor of the composite fillings. All materials showed
maturation of mechanical properties. The elastic component of the indentation was
smaller in compomers than in the composite. It was concluded that C-factor had no
influence on the cavity adaptation for compomer restorations. This might be due
to reduced stress generation at the bonding interface caused by relatively low
mechanical properties immediately after curing, less elasticity, and water
absorption in compomers.
PMID- 10786146
TI - Isothermal age-hardening behaviour in a Au-1.6 wt% Ti alloy.
AB - This study describes research with a view to developing a new age-hardenable,
high-carat dental gold alloy with better biocompatibility by addition of a small
quantity of titanium to gold. The relationship between isothermal age-hardening
and phase transformation of the Au-1.6 wt% Ti alloy was investigated by means of
hardness testing, X-ray diffraction study, scanning electron microscopic
observation and energy dispersive spectroscopy. The hardening in the initial
stage of ageing seemed to be attributable to the continuous precipitation of the
Au4Ti ordered phase in the supersaturated alpha solid solution matrix. The
overaging with softening was attributed mainly to the formation of precipitates
at the grain boundaries, which grew to bright lamellae and seemed to be composed
of the Au4Ti phase.
PMID- 10786147
TI - Inhibition of carious lesions in vitro around gallium alloy restorations by
fluoride releasing resin-ionomer cement.
AB - A new fluoride releasing resin-ionomer cement was used for bonding of gallium
alloy restorations in vitro. Etching, priming, and fluoride releasing resin
ionomer cement were used in the experimental group (ARG), prior to placement of
the gallium alloy restorations. Three different controls were used: gallium alloy
only (G), no etching, fluoride releasing resin-ionomer cement, gallium alloy
(RG), etching, priming, non-fluoride cement and gallium alloy (ACG). The mean
shear bond strengths of ARG group to enamel and dentin were higher than those of
the three control groups. Artificial secondary caries lesions around the
restorations in the experimental group and the control groups were produced,
using a strep. mutans culture. The microradiographs were examined for presence of
a caries inhibition zone near the restoration. Caries inhibition zones were
clearly detected around RG and ARG, but not around G and ACG. The results
indicate that the fluoride releasing resin-ionomer cement provided good adhesion
and caries inhibition in enamel and dentin.
PMID- 10786148
TI - 1H-NMR studies of the interaction of dental adhesive monomer, 4-META with
calcium.
AB - Our objective was to determine whether high-resolution proton-nuclear magnetic
resonance (500 MHz) could be utilized for detection of ionic binding interaction
of the 4-META resin system with calcium derived from hydroxyapatite. The
stability of 4-META in aqueous medium was studied, findings indicated that 4-META
was rapidly converted to 4-MET, a hydrate product of 4-META in 10% D2O/DMSO-d6.
The 1H-NMR signals of the methacryloyloxyethoxy group of 4-MET remained intact
following the addition of both monocalcium phosphate (MCP) and dicalcium
phosphate dihydrate (brushite) solution, whereas those of its trimellitic portion
were markedly shifted upfield depending on the phosphate concentration. The
shielding effect followed by upfield shifts was due to the localization of
electron density surrounding the carboxylate anions that were dissociated by the
interaction with calcium counter cation. The shielding effect of 4-MET with
brushite was larger than that with MCP. An ionic interaction of 4-MET derived
from 4-META with calcium was demonstrated.
PMID- 10786149
TI - Setting shrinkage and hygroscopic expansion of resin-modified glass-ionomer in
experimental cylindrical cavities.
AB - The effects of the C-value (bonded surface area/unbonded surface area) and the
volume of the cavity on the volumetric dimensional changes [volumetric setting
shrinkage (VSS) and volumetric hygroscopic expansion (VHE)] of a resin-modified
glass-ionomer (RMGI) filled in experimental cylindrical cavities were evaluated.
The VSS and the VHE rate decreased with increasing C-value. There was a high
inverse regression between the cavity C-value and volumetric dimensional changes,
but a low regression between cavity volume and volumetric dimensional changes.
Therefore, it was thought that greater contraction stress would remain in high C
value cavities than low C-value cavities during the setting process. It was also
confirmed that the volumetric dimensional changes of RMGI in cavity were
influenced primarily by the cavity C-value.
PMID- 10786150
TI - Cytotoxicity of dental resin monomers in the presence of S9 mix enzymes.
AB - The purpose of the this study was to evaluate the cytotoxicity of dental resin
monomers in the presence of a rat liver S9 mix containing cytochrome P 450
enzymes. JTC-12 cells derived from a monkey kidney were seeded on a 96-well multi
well-plate at 9 x 10(3) cells per well. After cultivation, the S9 mix was added
to the wells as an S9 mix group (+S9), and PBS- was added to the other wells as a
none-S9 mix group (-S9), then 7 different concentrations of various monomers were
added to each well. All the specimens were cultured for another 24 hrs. The cell
survival ratios (CSR) were calculated by using a neutral red cytotoxicity assay.
CSR for 50 micrograms/mL of Bis-GMA/S9 mix was 92.6% while for none-S9 mix it was
6.6%. The values of CSR for UDMA, Bis-MPEPP, EGDMA, TEGDMA, DMAEM, 4-META and
HEMA exhibited a reduction in cytotoxicity in the presence of the S9 mix. There
were significant differences between +S9 and -S9 for respective monomers (p <
0.05). However, there were no significant differences between +S9 and -S9 for MMA
(p < 0.05).
PMID- 10786151
TI - Effect of carboxyl group in O-methacryloyl-N-acyl tyrosines on adhesiveness to
unetched human dentin.
AB - We have reported that the carboxylic group plays an important role in the
adhesion of methacryloyl amino acid--2-hydroxyethyl methacrylate type restorative
resin to dentin surfaces. However, our study so far has been limited to the
methacryloyl amino acid that has only one carboxylic acid. In this investigation,
three new O-methacryloyl-N-acyl tyrosines (MAATY) that have one or two carboxylic
groups in the acyl group, and thus two or three carboxylic groups in MAATY, were
prepared and evaluated for their bond strength to unetched dentine. Higher bond
strength was observed when the MAATY contained larger number of carboxylic acid
groups. Factor analysis of the bonding strength revealed that the hydrogen bond
ability of the carboxylic acid and the hydrophile-lipophile balance (HLB)
affected the bond strength.
PMID- 10786152
TI - Strength and microstructure of gallium alloys.
AB - This study investigated the physical and mechanical properties and the
microstructure of four different gallium alloys. For all gallium alloys, the
compressive strengths measured at one hour (86-223 MPa) and 24 hours (265-286
MPa) after specimen preparation were found to be well within the range exhibited
by many high-copper amalgams. The creep values and dimensional change of the
gallium alloys were comparable to those of leading amalgams, except for the
dimensional change value of one alloy. The set gallium alloys consisted of a
multi-phase structure including beta-Sn, CuGa2, In4Ag9, Ag72Ga28, and Ga5Pd
(except for one product that did not contain Pd) that was more complicated than
the structure of dental amalgams. Although the gallium alloys had physical and
mechanical properties comparable to those of high-copper amalgams, the
microstructure, coupled with the instability of the element gallium itself, could
make these materials more prone to corrosive attack compared to amalgams.
PMID- 10786153
TI - The effect of primers on bond strength of polyacid-modified resin composites
(compomers).
AB - This study evaluated the effect of primer on shear bond strength and marginal
gaps of six new compomers immediately after light-activation. A resin-modified
glass ionomer cement, a conventional glass-ionomer cement and a microfilled
composite were used for comparison. The marginal gap widths of each of the four
compomers and a microfilled composite used with the primer were significantly
smaller compared with those used without the primer. The bond strength values of
five compomers used with the primer were significantly higher than those used
without the primer. The bond strength of conventional glass-ionomer was not
affected by the primer (or the conditioner).
PMID- 10786154
TI - Effect of functional monomer in commercial dentin bonding agents use of an
experimental dentin bonding system.
AB - The objective of the present study was to understand the role of the functional
monomers in dentin bonding agents of an experimental dentin bonding system by
measuring the wall-to-wall contraction gap and tensile bond strength measurement.
The efficacy of three commercial dentin bonding agents after using EDTA for
conditioning and GM for priming was evaluated by measuring the contraction gap of
the resin composite in a cylindrical dentin cavity, and by measuring the tensile
bond strength of the composite to a flat dentin surface. The effect of the
functional monomers was demonstrated by the contraction gap measurement alone.
The value of the contraction gap was significantly different between the
commercial dentin bonding agents and these agents without functional monomers (p
< 0.05). It was concluded that the functional monomers were essential to
obtaining the marginal integrity of the resin composite in the dentin cavities.
PMID- 10786155
TI - Formulation of glutaraldehyde disinfectant for alginate impressions.
AB - The effect of buffer agents incorporated in glutaraldehyde disinfectants on the
surface quality of dental models was examined by the measurement of surface
roughness, X-ray diffraction analysis and SEM observation. Seven experimental
glutaraldehyde disinfectants were prepared using two buffer agents, potassium
acetate alone or potassium acetate and sodium hydrogen carbonate in combination.
Four kinds of sulfate--zinc, calcium, potassium and magnesium sulfate--were added
to these disinfectants in order to accelerate the hydration of calcium sulfate
hemihydrate. The impressions treated with the experimental disinfectants for 1 h
produced stone surfaces which had significantly lower surface roughness values
than those treated with the commercial disinfectants (p < 0.05). The X-ray
diffraction analysis and SEM observation showed that these superior surfaces were
produced as a result of significant reductions in the amount of residual calcium
sulfate hemihydrate. Replacement of buffer agents in commercial glutaraldehyde
disinfectants with chemicals such as those studied in the present study will
improve the surface quality of dental stone.
PMID- 10786156
TI - Release and recharge of fluoride by restorative materials.
AB - This study investigated the release and recharge of fluoride by restorative
materials. Resin-modified glass ionomers (RGIs), polyacid-modified composite
resins (PMCRs) and resin composite containing fluoride were used for comparison
of fluoride release. Non-fluoride-releasing resin composite was used as a
control. The amounts of fluoride release from RGIs and PMCRs remarkably increased
in the citrate-phosphate acid buffer compared with distilled water. The amounts
of fluoride recharged in RGIs increased with the concentration of NaF solution,
but those of PMCRs exposed to all concentrations of NaF solutions were less than
1.5 ppm. Neither resin composite containing fluoride and non-fluoride-releasing
resin composite gave any evidence of recharge. RGIs and PMCRs affected by acid
buffer solution could not recharge much fluoride even if they were immersed in
the 1000 ppmF NaF solution. The results suggested that the matrix of RGIs and
PMCRs functioned as a reservoir of fluoride, but the functions were lost by acid
attack.
PMID- 10786157
TI - Development of a new high-speed measuring system to analyze the dental cast form.
AB - A new non-contact measurement system employing of a line laser and CCD camera was
developed to rapidly measure maloccluded dental casts with large depth and high
accuracy. In this system, the measuring interval along the line laser and the
model scanning direction perpendicular to the line laser were both 0.2 mm. By
averaging the raw data through repetitious input and smoothing by local
filtering, the noise was effectively decreased. Sub-pixel processing, which
calculates the pixel position with the largest brightness within one pixel,
improved the accuracy in the measurement to 22 microns compared with 65 microns
before sub-pixel processing. Dental casts with malocclusion were measured with
this system. The time and the depth for the measurement were about 10 minutes and
60 mm, respectively. This was a vast improvement compared with our previous
system employing a point laser. In the CG of the measured dental casts, smooth
and detailed surface morphology were sufficiently reproduced, and recognition of
the characteristic points in the cast could be accomplished with the accuracy of
30 microns. This measurement system will be helpful to analyze the dental cast
form with malocclusion in progress.
PMID- 10786158
TI - Gold alloys for resin bonding including small amount base metals--structural
changes of alloy surface by the high-temperature oxidation.
AB - To achieve durable bonding with adhesive resin, the surface roughness and the
kinds of oxides, respectively to increase mechanical retention to enhance the
chemical affinity of adhesive monomer with the gold alloy, were regulated by high
temperature oxidation together with the addition of small amounts of base metals.
Alloys containing 2 mass% of Ni, In, or Cr with Cu were oxidized at 800 degrees C
for 20 min in air, pickled in thioglycolic acid, and subsequently oxidized at 500
degrees C for 10 min in air. The morphology of the internal oxidation zone
changed markedly according to the added base metals. Although the internal oxide
particle composed of only Cu2O was removed by pickling, NiO, In2O3, and chromium
oxides could not removed and remained on the alloy surface. The surface roughness
was increased by addition of Ni, In, or Cr. Applying the present method can
control the roughness and chemical states on a gold alloy surface to increase its
adhesive ability with adhesive resins.
PMID- 10786160
TI - Effect of polishing on cyclic fatigue strength of CAD/CAM ceramics.
AB - The biaxial flexural strength and cyclic fatigue biaxial flexural strength of
CAD/CAM ceramics polished with #220, 400, 600 and 1000 diamond pads were measured
in an effort to determine the effect of surface roughness on fatigue behavior of
dental ceramics. The surface roughness was improved after polishing with a
smaller diamond grain pad. The flexural strengths of the specimens polished with
#220, 400, 600 and 1000 diamond pad were 75.2, 76.6, 82.2, and 83.3 MPa,
respectively; the fatigue flexural strength of those with #220, 400, 600 and 1000
were 53.0, 58.1, 60.0, and 61.5 MPa, respectively. Both the flexural and fatigue
flexural strengths increased with improvement of surface profile. These results
suggest the importance of polishing of dental ceramics for not only the static
strength but also the cyclic fatigue strength.
PMID- 10786159
TI - Lattice parameter changes of leucite by incorporation of various cations
substituted for potassium.
AB - Leucite crystals having modified compositions from stoichiometry were prepared by
the incorporation of Na+, Rb+, Cs+, Ca2+, Ba2+, and Sb3+ substituted for 5-50 at%
of K+ in the leucite. The lattice parameters of the a- and c-axes of these
tetragonal leucite were derived from the diffraction angles of (400) and (004)
peaks due to tetragonal leucite, respectively. Both lattice parameters of the a-
and c-axes of the leucites except Rb and Cs were slightly smaller than those of
stoichiometric leucite. The lattice parameters of the a-axis of the leucites
containing Rb and Cs were larger than those of stoichiometric leucite (p < 0.01)
and increased with the content of Rb and Cs. It was concluded that the crystal
lattice of leucite was deformed by the incorporation of cations substituted for K
and their variations mainly depend upon the kind of cation, namely ionic size and
substitution site in the lattice.
PMID- 10786161
TI - Relationship between Af temperature and load changes in Ni-Ti orthodontic wire
under different thermomechanical conditions.
AB - Simple three point bending tests were performed on Ni-Ti wires with three
different Af points (1 degree C, 13 degrees C and 34 degrees C) to clarify the
relationship between Af temperature and load changes under constant deformation.
Each wire was deformed at 37 degrees C and then thermal changes were imposed by
temperatures of 2 degrees C or 60 degrees C. The load changes with thermal
changes from 37 degrees C to 2 degrees C or 60 degrees C showed the same tendency
on the wires with different Af points: In the loading stage, the load became
lower than the initial level at 37 degrees C and in the unloading stage, the load
became higher than the initial load. The largest load change in the unloading
stage was measured with the 13 degrees C Af point wire. Care must be taken when
handling Ni-Ti wire with an Af point of less than 1 degree C in order to prevent
it from reaching the limit of critical stress of slip deformation when the
temperature in the mouth rises to above 40 degrees C.
PMID- 10786162
TI - Utility of Ni-Ti shape memory orthodontic wire.
AB - The characteristic temperature dependence of recovery force was evaluated for a
Cu-containing Ni-Ti shape memory wire with the nominal Af point being 40 degrees
C. It exerted mild recovery force within the range of the proposed optimum force
at the usual oral temperature. Larger forces were generated when it was heated to
temperatures above Af: 40, 50 or 60 degrees C. By subsequently cooling to
temperatures below Af, the force decreased again, and vice versa. The excellent
reversibility, reproducibility and durability of the recovery force were also
confirmed. These results indicate that the shape memory wire may be a reasonable
material for a new concept of intermittent orthodontic treatment, in which mild
force will be applied to the tooth for most of the daily hours and the tooth
movement will be intermittently accelerated by larger forces generated only when
the patient has hot foods or drinks.
PMID- 10786163
TI - Analysis of major components contained in Bis-GMA monomer.
AB - The major components contained in commercial Bis-GMA monomer were isolated by
thin layer chromatography (TLC) and identified by NMR and high resolution mass
spectroscopy. In addition to the two major components already known (Bis-GMA and
Iso-bis-GMA), an unknown hydrophilic third major component was isolated and
identified as 2,2-[4-(2-hydroxy-3- methacryloyloxy-1-propoxy)-4'-(2,3-dihydroxy-1
propoxy)]dipheny lpropane. This compound was designated as BIS-GMA-H, because it
has a structure of Bis-GMA with one of which methacrylic ester bond hydrolyzed.
PMID- 10786164
TI - Effects of thermal cycling on dynamic viscoelastic properties of four commercial
resins for crown and bridge.
AB - To elucidate the effects of thermal cycling on the viscoelastic properties of
four commercial resins for crown and bridge, dynamic shear modulus (G'),
mechanical loss tangent (tan delta), Knoop hardness, water sorption and
appearance of specimen surfaces before and after thermal cycling test were
determined. The changes of G' and tan delta for two materials were insignificant
with increased repetitions of thermal cycling. Those of the other two materials
were statistically significant: in particular, G' at temperatures above 60
degrees C was inclined to increase slightly and tan delta decreased considerably.
While the Knoop hardness of the materials was a little decreased over a number of
75,000 thermal cycles, the water sorption almost attained an equilibrium in
uptake after 14,000 thermal cycles. Furthermore, cracks on the specimen surface
were observed after 37,500 to 75,000 thermal cycles. From these results, the
deterioration of materials was observed as damage to the specimen surface.
Moreover, it could be presumed that the materials would be further polymerized
during the period of thermal cycling.
PMID- 10786165
TI - Adhesion of a new commercial self-etching/self-priming bonding resin to human
caries-infected dentin.
AB - We have examined the adhesive properties of a new commercial self-etching/self
priming bonding resin (Unifil Bond, UB) to normal and caries-infected dentin of
human extracted molars using scanning electron microscopy (SEM) and a micto
tensile bonding strength (MTBS) test. In this study, 7 human extracted molars
with moderate occlusal caries were used, and flat surfaces including occlusal
dentin caries were prepared from the teeth. After the application of UB to the
surfaces, a composite resin was built up, and subjected to the measurement of
MTBS and SEM observation of the interfacial morphology between UB and dentin. The
MTBS of UB to normal dentin was 33.4 MPa, but that to caries-infected dentin was
11.0 MPa. There was a significant difference between the MTBS to normal and
carious dentin. SEM observation revealed that the typical hybrid layer was not
formed in caries-infected dentin. These results suggested that resin infiltration
into caries-infected dentin was not sufficient to allow perfect sealing of the
restoration.
PMID- 10786166
TI - Firing shrinkage of porcelain-resin composites prepared by laser lithography.
AB - Using porcelain and resin-mixed composites as experimental materials, cubic
polymerized composites were prepared by the accumulation of thin slices cured by
laser scanning. The composites were then fired, and bulk ceramic bodies were
made. The optimal firing conditions of polymerized composites and firing
shrinkage were investigated. The results showed that cubic ceramic bodies in a
form homologous to that before firing could be reproduced. The volume shrinkage
of fired ceramic bodies consisting of 1 g of ceramic powders and 0.3 g of epoxy
resin was about 30% under all firing conditions, and there were no significant
differences between specimens. It was suggested that with further research and
development, three-dimensional forms for clinical use in dentistry could be
manufactured by the proposed method.
PMID- 10786167
TI - Influence of filler content and gap dimension on wear resistance of resin
composite luting cements around a CAD/CAM ceramic inlay restoration.
AB - We investigated the influence of filler content and gap dimension on the wear
resistance of composite luting cement around CAD/CAM ceramic inlay restorations.
Experimental hybrid dual-cured composite luting cements containing 60, 70, 72, 74
and 80 wt% of silanated barium-silica fillers were used for cementing CAD/CAM
ceramic inlay into the cavity. The specimens involving inlay-cement-tooth
interfaces were subjected to a three-body wear test. The relation between the
interfacial gap dimension and wear loss was also investigated using 60, 70 and 80
wt% filled cements. The cements containing more than 70 wt% filler presented
significantly higher wear resistance than 60 wt% filled cement. There was a
positive linear relationship between gap dimension and wear loss, and the
inclination of the regression line decreased with increasing filler content.
These results indicated that the higher filler content of the cement increased
the wear resistance and this desirable influence appeared more remarkably in the
wider horizontal gap dimension.
PMID- 10786168
TI - Experimental impression tray fabricated with a NiTi shape memory alloy plate.
AB - A small experimental impression tray was fabricated with a NiTi shape memory
alloy plate. After recovery of the shape memory effect, the upper rims of the
tray holding the impression were opened to some extent, the resistance during
removal of the model from the impression was significantly decreased compared to
a commercially available tray and the tray before recovery of the shape memory
effect. The pull-out force of the model from the impression was 23.5(0.2)N for
the commercially available tray, 23.5(3.9)N for the experimental tray before
recovery of the shape memory effect and 14.7(4.0)N after recovery of the shape
memory effect (heated for 15 min at 70 degrees C). Therefore the tray should be
useful in teeth fracture free modeling.
PMID- 10786169
TI - Conservative restorations with powerful capabilities, Part 1.
PMID- 10786170
TI - A predictable, conservative, technique for natural-looking posterior composite
placement.
PMID- 10786171
TI - Enhanced aesthetics using pressed ceramics.
PMID- 10786172
TI - Direct composite veneers to create a mature smile.
PMID- 10786173
TI - Best of both worlds: stainless steel and nickel titanium.
AB - The integration of the Quantec (0.06 taper 0.25-mm tip) rotary NiTi file and the
standard stainless steel K-file (ISO 0.02 taper) synergistically simplifies
instrumentation of the canal. The rotary NiTi file is primarily used to flare the
coronal and midportion of the canal. Its flexibility enables clinicians to do so
without ledging and perforation. Because of its effective cutting ability, the
stainless steel file is used to clean and shape the apical area of the canal and
blend the apical portion into the flare. Ultimately, this simplifies the
obturation process. When familiar with this technique, dentists may find it
easier to work with sequential tapers offered in the Quantec series of
instruments. This series has a of tapers from 0.02 to 1.2. Understanding the
crown-down concept and using quality and reliable instruments facilitates
improved productivity.
PMID- 10786174
TI - Implant-level transfer impressions.
PMID- 10786175
TI - Prosthetic joints, dental treatment, and antibiotic prophylaxis.
AB - Dentists should be familiar with the newest antibiotic prophylaxis
recommendations for joint prosthesis patients undergoing dental treatment. The
guidelines identify physical conditions that place joint patients at the highest
risk for joint sepsis. They also stratify dental procedures into higher- and
lower-risk categories. Combining these two groupings clarifies the dentist's
strategy for antibiotic prophylaxis regimens, which are greatly simplified. Of
notable importance is the elimination of posttreatment antibiotic dosing. A large
group of patients who do not require antibiotic prophylaxis prior to dental
treatment are also identified by the guidelines. Every dentist must use clinical
judgment, knowledge of the patient, and consultation with the attending physician
to determine the appropriate treatment plan.
PMID- 10786176
TI - Bridging the gaps.
PMID- 10786177
TI - The link between periodontal disease and systemic health: a scientific update.
Interview by Phillip Bonner.
PMID- 10786178
TI - Marketing profit centers in a cosmetic practice: power bleaching.
PMID- 10786179
TI - The importance of technique in preventing postoperative sensitivity when placing
bonded restorations.
AB - This article has focused on what are thought to be some of the common causes of
postoperative sensitivity following placement of adhesive restorations. Of
course, there can be many other factors. There are an infinite number of roads or
combinations of roads that won't get dentists where they want to go. However,
there is a specific road or roads, when taken carefully in the proper sequence,
that will predictably get dentists to their destinations. The same is true for
bonding. Adhesive dentistry is by no means difficult, but it is exacting. If the
rules are understood and followed precisely, dentists will find the results are
well worth the effort.
PMID- 10786180
TI - Predictable, aesthetic, full-mouth reconstruction.
PMID- 10786181
TI - Ultimate aesthetics with composites: when art and science merge.
PMID- 10786182
TI - Managing soft tissue using a laser: a 5-year retrospective.
PMID- 10786183
TI - Advanced adhesive technology.
PMID- 10786184
TI - Creating exceptional soft tissue contours for fixed anterior bridges and veneers.
PMID- 10786185
TI - Restoring anterior aesthetics and occlusion.
AB - The use of Empress2 material in this specific case produced the strong
restoration desired and allowed reproduction of natural vitality and
translucency. The results offered by the material exceeded patient as well as
doctor expectations.
PMID- 10786186
TI - Orascopy: a vision for the new millennium, Part 2.
AB - The advent of orascopy as a cutting edge technique has changed the way
endodontists visualize as well as think about endodontics. As practitioners begin
to see and understand endodontic etiology, it will enable oral physicians to
provide treatment based on visual confirmation rather than radiographic
estimates. In the future, conventional orascopic endodontics will be done very
much like physicians provide treatment. It will be more qualitative rather than
quantitative. Dentists will not need to make measurements of canals from
radiographs; they will use orascopy to instrument, irrigate, and obturate while
viewing the root canal system in real time. Surgical orascopic endodontics will
continue to improve surgical treatment results because enhanced visualization has
enabled endodontic surgeons to identify and treat endodontic etiology.
PMID- 10786187
TI - Prosthetic considerations with periodontal root resective therapy, Part 2.
Hemisections.
AB - When a root and the overlying anatomic crown are removed as a unit, this
procedure is referred to as a hemisection. Hemisection of a maxillary or
mandibular molar is often a means of retaining teeth needed for restorative
abutments or occlusal support. This treatment can yield predictable results using
proper diagnostic, endodontic, surgical, and prosthetic techniques.
PMID- 10786188
TI - Full-mouth restoration with TMJ involvement: a case report.
PMID- 10786190
TI - Extreme hygiene: taking the hygiene department beyond recall.
PMID- 10786189
TI - Clinical findings using a self-etching primer.
PMID- 10786191
TI - Six-month adult aesthetic orthodontic treatment.
PMID- 10786192
TI - Achieving high-quality comprehensive dentistry with i.v. sedation.
AB - This comprehensive approach requires a high-tech/touch staff environment and a
dedication to excellence in all areas of patient care. Its rewards are financial
and personal because it creates a highly satisfied and appreciative patient.
PMID- 10786193
TI - [Topotecan: a new discovery and future prospects].
PMID- 10786194
TI - [Preclinical pharmacology and clinical uses of topotecan].
AB - Topotecan, a soluble semisynthetic derivative of camptothecin, is a specific
inhibitor of topoisomerase I and is endowed of potent antiproliferative effect in
vitro and in vivo on tumoral cell lines as well as on endothelial cells.
Moreover, topotecan is able to interfere with the development of blood vessels in
many in vivo experimental models. During the last years, several phase I clinical
studies have demonstrated that the five-daily schedule is the most effective for
the treatment of neoplastic diseases of children and adults. In particular, the
best clinical results have been obtained in patients affected by metastatic
ovarian cancer, small cell (SCLC) and non-small cell lung carcinoma (NSCLC), as
well as mammary and gastrointestinal neoplasms. High response rates have been
observed in myelodysplastic syndromes and myeloma. The clinical effectiveness of
topotecan has been also demonstrated in ovarian carcinoma, even after failure of
first or second line chemotherapy and in SCLC, where the response rate is 39%,
while the percentage decreases up to 7% in case of drug resistance, with a median
survival of 5.4 months. Toxicologic profile of topotecan is foreseeable and
manageable, and the most frequent and severe toxicity is represented by
myelosuppression. Leukopenia and neutropenia, which follow the administration of
topotecan, are non-cumulative and self-limiting and unfrequently complicated by
infections, whereas non-hematologic toxicities are uncommon and generally of mild
to-moderate degree. Topotecan is under continuous clinical evaluation for the
treatment of neoplasms other than those reported above, alone or in combination
with antineoplastic drugs in poly-chemotherapeutic protocols.
PMID- 10786195
TI - [Topotecan: prospects for using it in combination therapy for ovarian carcinoma].
AB - Topotecan is a semi-synthetic, water soluble topoisomerase I inhibitor which has
recently been approved for the treatment of ovarian cancers after failure of
first-line therapy. A number of different dosing schedules are being investigated
in clinical trials including oral administration, a daily infusion on 5- or 3
consecutive days and a continuous infusion for 21 days. A 30-minute infusion of
topotecan 1.5 mg/m2 on 5 consecutive days every 3 weeks, as standard schedule,
produced response rates of 13.8 to 20.5% in the 3 largest phase II/III studies in
women with advanced ovarian cancers who had either failed to respond or had
relapsed after an initial response to platinum-based chemotherapy (N = 92 to
139), continuous 21-day infusion of topotecan 0.3 to 0.5 mg/m2 has shown efficacy
in 2 small phase II studies. There were no statistically significant difference
in efficacy between topotecan (1.5 mg/m2/day for 5 consecutive days every 21
days) and paclitaxel (175 mg/m2/day given over 3-h every 21 days) in the
randomized phase III study. In 3 large clinical trials, response to topotecan was
higher in patients who were platinum sensitive (19.2 to 29%) than in those whose
disease was platinum resistant or refractory (11.3 to 13.3%) not statistically
significant in 1 study, statistical analysis not reported in the other 2 trials.
Myelosuppression, particularly neutropenia, is the dose-limiting toxicity of
topotecan. It is reversible, dose-related and non-cumulative. In 2 large studies,
topotecan produced grade 4 neutropenia in 78 and 79% of patients and in 40 and
37% of all treatment courses (febrile neutropenia occurred during 3% of 552
courses in 1 study). Grade 4 thrombocytopenia was seen in 18 and 25% of patients
and in 6 and 10% of all courses, respectively. Grade 4 neutropenia was
significantly more common in patients receiving topotecan than in those receiving
paclitaxel (79 vs 23%), as was grade 4 thrombocytopenia (25 vs 2%), in a single
randomized clinical trial. Non-hematological adverse events during topotecan
therapy were mostly mild. A step beyond is the combination treatment including
topotecan as a 3- or 5 days schedule plus a platinum compounds or topoisomerase
II inhibitor. These associations of drugs are based on the preclinical data of
the in vitro studies showing a synergy of the anti-tumor activity. A novel
schedule of topotecan is also the "alternating" chemotherapy consisting of
different doublet of drugs given as a sequential way or as a really sequential
topotecan therapy. Both methods of combining topotecan as second/salvage
treatment or front line therapy are being investigated by numerous authors.
Preliminary data suggest interesting results in terms of efficacy, manageable
toxicity and new schedules of treatment for topotecan. Low dosages of drug in
combination with other agent do not seem to influence the well-known data of
efficacy or safety of topotecan literature. Probably the 3-day schedule allows a
combination treatment, otherwise not feasible with the standard 5-day
administration.
PMID- 10786196
TI - [Topotecan, a recent discovery and prospects for treating tumors of the lung].
AB - Topotecan is a new active drug in the treatment of lung cancer. In advanced non
small cell lung cancer (NSCLC) it showed 0-15% of objective response (OR) with
15% in the largest phase II study performed on 40 patients at the M.D. Anderson
Cancer Center. Interesting results have been reported in combination chemotherapy
with new drugs, in particular with gemcitabine. However, the role of topotecan in
NSCLC must be developed in further trials. Topotecan is one of the most active
drug in small cell lung cancer (SCLC). Particularly, it showed active in
sensitive pretreated patients with 14%-38% OR. In a phase III randomized trial
performed in pretreated patients, single agent topotecan showed similar OR and
survival but better palliative effect compared to the CAV regimen
(cyclophosphamide + adryamicin + vincristine). In first line chemotherapy
topotecan showed 39% OR as single agent. Interesting results have been showed in
combination chemotherapy in particular with taxol. Several studies are ongoing.
Topotecan as first line chemotherapy could be developed in old doublet
combinations (such as cisplatin or carboplatin + topotecan), new doublet
combinations (such as taxol or vinorelbine or gemcitabine + topotecan), triplet
chemotherapy combinations (such as cisplatin or carboplatin + taxol + topotecan)
and sequential or alternate chemotherapy regimens. Topotecan reaches high drug
concentration in the brain. It showed activity in brain metastases of SCLC with
40%-63% OR and 13%-43% of complete response in pretreated patients. This
particular activity could be considered in first line chemotherapy as prophylaxis
of brain metastases or to treat patients with brain metastases at diagnosis. Oral
topotecan is a very interesting drug. It showed 36% OR in outfit untreated SCLC
patients and 23% in pretreated patients, respectively. Oral formulation seems to
induce less toxicity when compared to the intravenous drug. In the future
topotecan should be developed as first line combined radio-chemotherapy treatment
to make the best of its radiosensitizer effect. The activity on brain metastases
also must be developed. Oral formulation is interesting because it is less toxic
and could be considered in less toxic regimens in particular in outfit or elderly
patients. However in the next years the role of topotecan will be better defined
performing phase III randomized trials.
PMID- 10786197
TI - [Topotecan: a new field of use].
AB - Topotecan, a semi-synthetic derivative of the alkaloid camptothecin is an
antitumor drug that like other camptothecin derivatives, targets DNA
topoisomerase I, an enzyme that is present in cells in concentration relatively
independent of the stage in the cell cycle. Topotecan stabilizes the complex
formed between topoisomerase I and DNA, leading to DNA strand breakage and cell
death. In accordance with preclinical studies, clinical efficacy of topotecan was
documented in ovarian carcinoma, in small cell lung cancer and in childhood solid
tumors. Myelosuppression is the dose-limiting toxicity and nonhematologic side
effects are generally mild. The activity of topotecan against a number of
hematological malignancies is now increasingly exploited as well as its role in
high-dose chemotherapy programs with stem cell support. In both lymphoblastic and
myeloid acute leukemias, topotecan has been widely utilised both as single agent
or associated to other cytostatic drugs with proven efficacy in these diseases.
Most of the published phase II studies demonstrated that heavily pre-treated,
relapsing patients achieve a high percentage of overall responses with manageable
toxicity. In myelodisplastic syndromes and acute myelomonocitic leukemias a
recently published study shows positive results for the combination of topotecan
and cytarabin. Topotecan seems to preferentially affect the abnormal cytogenetic
clones and in patients achieving a complete response, a conversion from an
aneuploid to a diploid karyotipe was documented. In non-Hodgkin lymphomas,
several schedules have been tested in the phase I setting. When utilized alone
and at very low dosage, the drug yielded 15% of objective responses and a lack of
extrahematologic toxicity. Of particular interest seems to be the association of
topotecan with taxanes that needs to be supported by growth factors. In multiple
myeloma Topotecan has been utilized as single agent in heavily pre-treated
patients. The obtained results show good activity and again myelosuppression as
preminent toxicity. The use of topotecan in high-dose chemotherapy regimens for
multiple myeloma has been proposed. The utilization of topotecan in high-dose
chemotherapy is one of the newer and more interesting applications. Solid tumors
(i.e. ovarian cancer and small cell lung cancer) are actually investigated by
many authors, who have indicated that this drug can be used preferentially as a
part of diversified programs containing overlimit dosages of different
cytostatics. Furthermore, topotecan demonstrated to be an effective drug to
mobilize CD34+ cells for autografting. A general conclusion is that topotecan is
an interesting addition to the actual chemotherapy scenario, both because of its
mechanism of action and its toxicity profile. The present review of the new
possibility of utilization, give us the idea that topotecan has activity in
several hematologic neoplasias; further investigations in these diseases (i.e.,
induction treatment, combination chemotherapy) are then warranted. The broad
spectrum of antitumor activity and the characteristics of toxicity make it also
interesting for use in both the circulating progenitor cell mobilization and in
the consolidation phase of high-dose chemotherapy programs.
PMID- 10786198
TI - Algorithm for assessment of the oxygen, acid-base and electrolyte status (ALBOA
BEACH).
AB - To achieve accurate interpretation of blood gas analysis data in intensive care
units, the oxygen, acid-base and electrolyte-metabolite profile of arterial blood
should be comprehensively and adequately monitored and assessed. A number of
diagnostic software programmes have been developed to assist clinicians in this
and to help improve instruction in this field. In the present study we describe
an algorithm and a programme for assessment of the oxygen, acid-base and
electrolyte status of the arterial blood. The algorithm, as well as the software
programme, is named ALBOA BEACH, which is an acronym of the programme's full name
-ALgorithm for Blood Oxygen, Acid-Base, Electrolyte And respective CHarts. The
algorithm takes account of the latest achievements in blood-gas analysis; it can
be used both in on-line and off-line modes and is useful in the laboratory and
pathophysiological assessment of blood-gas disorders. The algorithm is based on a
rigorous pathophysiological analysis and the interpretation achieved as a result
is much more accurate than usual. Thus it provides a most reliable basis for
taking the right clinical decision and making the proper prognosis of the
possible critical conditions. The algorithm also provides additional bases for
interpretations of data in the borderline zones, with due warnings in cases of
absence of physiological coherence between the various parameters and modules.
The programme is designed to be used with the modern multifunctional blood-gas
analysers; it can be of assistance in making diagnoses, in the training and
research activity in the intensive care units and specialised blood gas
laboratories.
PMID- 10786199
TI - Comprehensive assessment of ventilatory functions of patients with chronic heart
failure.
AB - OBJECTIVE: A comprehensive assessment of the ventilatory functions of patients
with chronic heart failure (CHF) both at rest and during a cardiopulmonary
exercise test (CPET). We studied 42 males, divided into two groups--patients with
CHF (n = 21) and age, weight, height and BMI matched healthy controls (n = 21).
All subjects underwent a symptom-limited ramp CPET, arterial blood gas analysis,
and complex functional examination of the pulmonary system. Subjective rating of
dyspnea and exertion were measured by the Borg and ATS dyspnea scales. CHF
patients showed a slight, but statistically significant decrease of the
spirographic and diffusion parameters, as well as of the indices of respiratory
muscle strength. There were no changes in blood gases and in tidal breathing
parameters. The exercise capacity was markedly reduced (VO2peak ml.min-1 1352 +/-
335 CHF patients vs 2077 +/- 276 healthy controls; p < 0.001) and the anaerobic
threshold occurred earlier (< 40% of predicted VO2peak) during CPET in CHF
patients. The increase in VE/VCO2 in CHF patients (35.7 +/- 5.1 CHF; 28.9 +/- 2.5
HC, p < 0.001) indicates a compromised ventilatory efficiency which leads to a
higher dyspneic cost of exercise (Borg peak 9.5 +/- 1.03 CHF; 6.0 +/- 1.28 HC; p
< 0.001) as compared with healthy controls.
PMID- 10786200
TI - Plasma levels of branched chain amino acids in patients on regular hemodialysis
before and after including a high-protein supplement in their diet.
AB - Chronic renal failure (CRF) patients on hemodialysis have low plasma level of the
branched chain amino acids (BCAA) leucine, isoleucine, and valine. The
abnormalities in the plasma amino acid pool can be corrected with appropriate
high-protein supplements. The present study was designed to evaluate the effect
of a balanced protein nutritional supplement on the plasma level of BCAA. Twenty
eight CRF patients who received hemodialysis treatment three times in a week were
enrolled in the trial. The initial plasma levels of BCAA were as follows--leucine
15.46 +/- 3.88 mcg/ml, isoleucine 9.08 +/- 1.97 mcg/ml, and valine 24.05 +/- 5.06
mcg/ml. For a period of 6 months the patients received a balanced nutritional
supplement (58-59% total protein content, leucine--8.6, isoleucine--4.8, and
valine--5.7 g/100 g protein) on the day of hemodialysis at a dose 1.0 g/kg body
weight. Three months after beginning of supplementation the plasma level of BCAA
was found to be elevated--leucine by 36% (P < 0.001), valine by 30% (P < 0.001),
and isoleucine by 27% (P < 0.001). The body mass index of the patients was also
above the initial values. The plasma BCAA levels were maintained high until the
sixth month from the beginning of trial and even a month after withdrawal of the
supplement. The results obtained allow us to recommend inclusion of protein
supplements with balanced amino acid content in the diet of these patients.
PMID- 10786201
TI - Metabolic changes in children with severe traumatic injuries.
AB - INTRODUCTION: Combined traumatic injuries are the leading cause for more than
half the cases of lethal outcome in childhood. Trauma triggers a series of
endocrinic and metabolic changes commonly known as acute metabolic stress. The
hypermetabolic and hypercatabolic condition which develops as a result
contributes to the high morbidity and mortality rates in children with traumatic
injuries. METHODS: Twenty five children (16 boys and 9 girls aged 4-15 years)
were recruited from the patients admitted for treatment to the Department of
Pediatric Anesthesia and Intensive Care at the Clinic of Pediatric Surgery in the
Higher Medical Institute--Plovdiv, between 1994 and 1998. All children had severe
combined trauma. Of these 20 (80%) presented with severe craniocerebral trauma;
they were comatose with Glasgow Coma Scale Score of 7.3 +/- 4.3 (Sx = 3.59); the
children were on mechanical ventilation and total parenteral nutrition. Energy
expenditure was measured using computerised metabolic monitor Deltatrac II. VO2,
VCO2, RQ, energy expenditure (MEE), oxygen consumption and nitrogen excretion
levels were monitored. RESULTS: The mean energy expenditure measured during the
first, second and third 24-hour period was 50.04 kcal/kg/d-1, 50.54 kcal/kg/d-1
and 51.38 kcal/kg/d-1, respectively; the respiratory quotient was 0.81 +/- 0.0114
Sd, the oxygen consumption index 7.32 +/- 0.08 Sd ml/min/m2. The energy
expenditure calculated by the Fleisch formula was 42.38 +/- 1.24 kcal/kg/d-1, (Sx
= 6.19); this value differed statistically significantly from the value we
measured (50.63 +/- 1.31, Sx = 6.57, p < 0.0001), the injury correction factor
(ICF) was calculated to be 1.22 +/- 0.02 Sd. CONCLUSIONS: Actual energy
expenditure in children with severe traumatic injuries is considerably higher
than that calculated by formulae. Based on our results we recommend that the
energy and substrate intake to be increased above the values calculated by
formulae by a coefficient of 1.22 which is the measured correction factor. Thus
the increased energy requirements will be met and the patients' prognosis will be
improved.
PMID- 10786202
TI - Our experience in the treatment of acute Amanita phalloides poisoning.
AB - INTRODUCTION: The present study aimed at investigating phalloid mushroom
poisoning and the toxicological aid services in Plovdiv region as this pathology
shows in this country high mortality rate (40-100%) and increasing incidence; it
is difficult to diagnose and is far from featuring adequately in the literature
in our country. MATERIAL AND METHODS: A caseload of 270 patients with mushroom
poisoning from Plovdiv region, Bulgaria, admitted for treatment to the Clinic of
Toxicology, Higher Medical Institute, Plovdiv, for the period 1991-1998 was
studied. Of these 270 patients 25 (9.26%) had an acute phalloid poisoning. The
following indicators were registered: gender, age, reported type of consumed
mushrooms, time of appearance of the first complaints after the mushroom
consumption, time of medical aid, disease outcome. The diagnosis and the applied
treatment was based on our own diagnostic-therapeutic protocol for phalloid
intoxication. RESULTS: All phalloid poisoning cases were accidental by character.
The most frequently reported type of ingested mushroom was unidentified wild
edible mushrooms. Of all the patients males were 56%, females--44% with mean age
of 47.71 years (SD = 17.53). From 25 phalloid poisoning cases 15 survived (60%),
10 died (40%). The summer-fall seasonal pattern of phalloid poisoning occurrence
was apparent. The mean duration of the latency period was 12 hours (SD--6.66). In
4 (16%) patients the disease exhibited an unusually early onset--up to 2 hours
after the mushroom ingestion. The mean time period from the mushroom ingestion to
the presentation in a medical institution for first medical aid was 32 hours (SD-
21.69), for men--27.59 hours, for women--43.75 hours. Almost one third (32%) of
the diseased presented for medical help more than 36 hours after the poisoning.
CONCLUSIONS: The acute mushroom poisoning cases in adults comprise 7.01% of the
total acute poisoning caseload. The phalloid poisoning accounts for 9.26% of the
total number of patients with mushroom poisoning admitted for treatment. The
application of contemporary diagnostic-therapeutic protocol lowers the hospital
lethality rate from phalloid poisoning to 40%. There were no statistically
significant differences in the compared parameters between the subgroups of
patients with favorable and lethal outcome and between the subgroups of men and
women--most probably due to the small sample. In order to lower the incidence and
mortality rate from phalloid mushroom poisoning the authors recommend preventive
health education on the problem, targeting the population at risk and the
introduction of contemporary diagnostic and treatment methods--determining the
amatoxins, intravenous application of Silibinin and liver transplantation.
PMID- 10786203
TI - Trends in the incidence of colorectal carcinoma in three regions of south
Bulgaria for the period 1985-1998.
AB - The purpose of the present study was to evaluate the increase of colorectal
carcinoma incidence in three regions of South Bulgaria (a total population of
1,269,464 persons) over a 14-year period (1985-1998). The data about the
incidence rate are retrieved from the oncological hospital records of the
patients and Bulgarian National Oncological Register. The census data are
provided by the National Institute of Statistics, Sofia. The results show that
the incidence rate of colorectal carcinoma for the studied period increased
steadily from 22.14/100,000 to 37.18/100,000 (an increment of 15.04/100,000)
which is almost twice the average for the country. Compared to the baseline year
of 1985 the increase in these three regions is 67.93% or approximately 5%
annually. The incidence rate in Plovdiv region was almost twice that of Smolyan
region. The incidence rate of colorectal carcinoma in both genders was greater
than that of stomach cancer. The highest incidence rate was found in the 70-79
year-age group (193.5/100,000). A major part of our study was to find the stage
in which colorectal carcinoma (CRC) is detected. In 1985 only 0.57% of the
patients were diagnosed as being in the I-st clinical stage, 37.76%--in the II
nd, and 61.67%--in III-IV clinical stages. This unfavorable trend was preserved
in 1998, when only 3.17% were diagnosed as having the first clinical stage,
38.62%--the II-nd and 58.21%--the III-IV clinical stages. The 14-year pronounced
trend of increase of the prevalence rate (a 2.91 times increment) and the
mortality rate (a 2.50 times increment) of colorectal carcinoma is especially
alarming. We propose screening of the asymptomatic patients and high-risk persons
which gives considerable results in the timely diagnostics of colorectal
carcinoma.
PMID- 10786205
TI - Immunocytochemical expression of p75LNGFR and trkA in Leydig cells of the human
testis.
AB - The authors demonstrate for the first time the immunocytochemical expression of
the low-affinity neurotrophic growth factor (NGF) receptor p75LNGFR and the high
affinity NGF receptor trkA in the human testis. Employing the polyclonal anti
p75LNGFR antibody and the polyclonal anti-trkA antibody they report strong
immunoreactivity for those antigens in the interstitial Leydig cells. Sertoli
cells and some cellular elements of the germinative epithelium were also trkA
positive. These findings implicate the neurotrophic factor NGF and its receptors
p75LNGFR and trkA in the autocrine and paracrine regulation of the steroidogenic
activity of Leydig cells of the human testis.
PMID- 10786206
TI - Frequency and clinical characteristics of mycoplasma urinary tract infections in
the early post-transplantation period in renal allograft patients.
AB - Using a highly sensitive and specific polymerase chain reaction (PCR) protocol,
we studied 36 renal allograft recipients and 30 healthy controls. Midstream urine
samples were analyzed using routine microbiological methods and the Mycoplasma
IST (BioMerieux, France). Mycoplasma infections of the upper urinary tract were
found in 9 patients. In three of them E.coli and Proteus were also present. We
discuss the clinical characteristics of mycoplasma infections in the early post
transplantation period and its possible implications for graft rejection.
PMID- 10786204
TI - Individual results of treatment of COPD with low doses of fenoterol compared with
treatment with ipratropium bromide.
AB - We compared the effects of 30-day treatments with fenoterol in low doses (4 x 100
mcg) and ipratropium bromide (4 x 40 mcg) on the lung function parameters (LFP),
dyspnea and physical capacity of patients with severe chronic obstructive
pulmonary disease (COPD) (FEV1 < 35% pred.) and analysed the individual response
of patients to the administered therapy. The study included two groups of
patients treated with fenoterol (n = 22) and ipratropium bromide (n = 22). The
patients were matched by functional characteristics (age: 60 +/- 7 and 57 +/- 9
years; ATS Dyspnea Scale: 2.7 +/- 0.8 and 2.4 +/- 0.9; FEV1%: 25 +/- 7% and 23 +/
6%; pO2: 62.4 +/- 5.3 mm Hg and 61.0 +/- 9.5 mm Hg; all values mean +/- SD).
After 30 days of treatment we measured the lung function parameters (FEV1, FVC),
dyspnea indices (ATS dyspnea scale, Borg scale) and the physical capacity of the
patients (6-minute walking distance test). The results showed that in an open
experiment fenoterol (4 x 100 mcg daily), unlike ipratropium bromide (4 x 40 mcg
daily), cannot improve statistically and clinically significantly the lung
function parameters, dyspnea and the physical capacity of the group as a whole.
However, when the findings were assessed for each patient individually, 32% of
the patients proved to have responded positively to the treatment. Therefore
efficaciousness of fenoterol in low doses should be determined by assessing the
lung function parameters, dyspnea and the physical capacity individually for each
patient.
PMID- 10786207
TI - Somatotyping of schizophrenic and affective disorder patients.
AB - INTRODUCTION: Constitutional traits have been found to show a distinct relevance
to major psychiatric disorders. Syndromal modified expressivity is also closely
related to somatotypic constitution. In this view somatotyping appears valuable
in diagnosis and prognosis of mental disorders. AIM: The present study was
conducted in an attempt to outline somatotypic characteristics of schizophrenia
and affective disorders with the aim of providing a logical basis for diagnosis
of these major psychiatric disorders. MATERIAL AND METHODS: The somatotype of 54
schizophrenic and 68 affective disorder inpatients who fulfil the DSM-IV criteria
for schizophrenia (subjects with schizophreniform, schizoaffective, schizoid and
schizotypal personality disorders were excluded from the sample) and affective
disorder (bipolar and unipolar) was assessed using the Health-Carter
anthropometric method. RESULTS: The overall assessment of the somatotypes
determined both groups as endomorphs mesomorphs with somatotype components 4.50
4.44-1.90 for schizophrenic patients and 5.87-5.40-0.36 for affective disorder
patients. The difference between the two groups was statistically significant for
any of the somatotype components. CONCLUSION: It is suggested that the
constitutional and somatotypic characterization appears reasonable element in the
multifactorial analysis of diagnostic decisions in these major psychiatric
disorders.
PMID- 10786208
TI - Antifungal prophylaxis with low doses fluconazole in patients with hematological
malignancies.
AB - INTRODUCTION: The incidence of mycotic infections in immunocompromised patients
has reached a 20-fold rise for the last two decades. AIM: The goal of the study
was to evaluate fluconazole efficacy as antifungal prophylaxis in patients with
hematological malignancies. MATERIAL AND METHODS: Sixty nine patients with
hematological malignancies and neutrophil count less than 1.0 x 10(9)/L received
fluconazole orally at a dose of 150 mg every other day. Fluconazole was
discontinued when a neutrophil count above 1.5 x 10(9)/L was maintained. Duration
of neutropenic periods, afebrile cycles, and incidence of mycotic infections were
assessed. The same variables were observed in a control group of 41 patients who
did not receive antifungal prophylactic therapy. RESULTS: Both groups were
similar in the mean duration of neutropenic period but the afebrile cycles in the
patients receiving antifungal prophylaxis were longer by 5 days compared to these
in the patients without prophylaxis. The mycotic infections had lower incidence
in the patients on antifungal prophylaxis and the difference was statistically
significant (p < 0.01). The superficial mycotic infections composed the majority
of the clinically and/or microbiologically verified infections. These were
presented by oropharyngeal infection (61%), esophageal (22%), and single cases of
skin, genital or rectal infections. Candida albicans was isolated in 85% of the
cases. The adverse reactions of fluconazole therapy were mild, transient, and
easily manageable. No signs of liver and renal dysfunction were observed.
CONCLUSION: Lower dose of fluconazole, 150 mg every other day p.o., has the same
antifungal effect as a dose of 200 mg/day p.o. in neutropenic patients with
hematological malignancies which lowers the cost of treatment.
PMID- 10786209
TI - Epidemiologic studies of leptospiroses in the Plovdiv region of Bulgaria.
AB - BACKGROUND: The natural habitat of leptospira along the Maritsa river, the high
level of development of the land-cultivation and cattle-raising underscore the
importance of establishing the exact prevalence of leptospiroses ranking it among
the highest in the country. The changes occurring in the economy and land-making
of the country following 1990 are reflected in the prevalence of leptospiroses
during this period. MATERIAL AND METHODS: We studied 95 patients of the
Infectious Disease Clinic of the Higher Medical Institute of Plovdiv with
serological evidence for leptospirosis for the period 1987-1998. The patients
were analyzed based on the following criteria: morbidity, age, gender, season,
etiologic structure, mechanism and factors for the transmission of disease etc.
RESULTS: The morbidity rate of Leptospira has shown a clear tendency towards
increase since 1992. In terms of etiology L. pomona ranked first accounting for
44.22% of the cases as compared with the prevalence of L. tsalapitsa--22.10%. The
isolation rates of those who had been infected during contact with animals (swine
predominantly) was 40.44%, during plant watering--38.95%, and 17.89% resulted
from bathing in the Maritsa river or its tributaries. Patients in the high-risk
groups were characteristically 20-39 years old, cattle-raisers, fishermen, land
workers. The highest number of registered cases occurred in July through August.
CONCLUSIONS: Based on these results from the epidemiologic study effective
measures aimed at the reservoir, mechanism of transmission of the infection and
the risk groups can be implemented so that the epidemiologic and epizootic
control of leptospiroses can be improved.
PMID- 10786210
TI - A rare case of fibrosarcoma of the inferior vena cava expanding into the right
atrium.
AB - The authors report in detail a case of fibrosarcoma of the inferior vena cava. A
53-year-old female presented with echographic and computed tomographic evidence
of a solid formation in the porta hepatis that fused with the inferior vena cava.
Because of appearance and rapid development of symptoms of right cardiac failure,
the patient was transferred to the Clinic of Cardiac Surgery and underwent an
emergency operation. A solid formation arising from the inferior vena cava and
expanding into the right atrium was found during the operation. The operation
performed was not a radical one. Fibrosarcoma of the inferior vena cava was
proved on histological examination. A single therapeutic course with vincristine
and farmorubicin was administered. The patient died from recurrence of the
malignancy 26 months after the operation. The epidemiologic, diagnostic, and
therapeutic aspects of the case are discussed in relation with the literature
data.
PMID- 10786211
TI - [Deformation and mutability of family and society picture in paranoid
schizophrenia].
AB - The aim of the study was to show how the frequency of special subjects of
delusions and hallucinations changes in time. A group of 400 in-patients with the
diagnosis of paranoid schizophrenia divided into four equal groups from the years
1932, 1952, 1972 and 1992 was examined. Data were obtained from case histories
from the archives of Neuropsychiatric Hospital in Lubliniec. Results of this
study allowed for establishing the following conclusions: the character of
paranoid picture of a family and a society is hostile, this feature is expressed
mainly in the time after the Second Word War; delusions of jealousy are more
frequent in women and they are more variable than in men--they prevail in the
postwar period.
PMID- 10786212
TI - [The therapy of families of patients suffering from schizophrenia].
AB - The development of pharmacotherapy, social psychiatry and the new patterns of
comprehensive treatment of patients suffering from schizophrenia make most of
psychiatrists believe that hospitalisations should be reduced to minimum. There
has been a change in the roles and tasks of parents and spouses of the patients
during their ambulatory therapy. Apart from outpatient clinics, daily wards, and
hostels, there is a significant role of the therapy of families of the patients
in the posthospital treatment. The patterns of schizophrenia as a disease and the
relating indications concerning basic therapeutic management are of significant
importance. The work presented here discusses two basic therapies of the families
of patients suffering from schizophrenia, namely psychoeducation and systemic
family therapy. The work draws attention to aims, forms and concepts of these
therapies. However, an appropriate pharmacotherapy of patients suffering from
schizophrenia is necessary regardless of their positive response to the families.
PMID- 10786214
TI - [Clozapine treatment: possibilities and limitations].
AB - The purpose of this article--based on the recent years literature--is discussing
the principles of the use of clozapine in schizophrenia, with the special
attention to treatment-resistance as a main indication, dose selection and
duration of the trial. In spite of dynamic development of pharmacotherapy of
schizophrenia, clozapine, registered in Europe 25 years ago, still remains a drug
of choice in treatment-resistant schizophrenia, that is in 5-25% of patients,
bringing a substantial clinical improvement in 30-50% of the group. The main
factor limiting the possibility of the use of clozapine is the increased risk of
neutropenia and agranulocytosis, what demands the WBC monitoring. Old age and
female sex are considered to be potential risk factors. In both classical
neuroleptics and clozapine, no clear linear correlation was noticed between the
dose and clinical effect. It seems, however, that only in case of clozapine a
noticeable correlation exists between the plasma level and clinical improvement.
Many authors try to define a threshold level sufficient/necessary to achieve
improvement. Suggested amounts are between 250-420 ng/ml. With fixed doses used,
extremely different levels of clozapine are observed (from a few, to thousands
ng/ml), so measuring plasma level is suggested as a routine procedure in cases of
clozapine-resistance. The duration of the trial creates real controversy. Most
authors agree that six weeks time, sufficient to diagnose treatment resistance in
case of typical neuroleptics, may be too short for clozapine. At the same time,
the postulated prolongation of the trial to a few months or even one year,
explained by the presence of late improvements, is not well and generally
accepted. It seems that time of 2-4 months is in most cases sufficient to notice
the potential advantage. The problem of clozapine-resistance still remains open.
Many strategies are being proposed (augmentation with lithium, valproate,
sulpiride and benzodiazepines), but they demand further examination.
PMID- 10786213
TI - [Subjective aspects of psychopharmacology in schizophrenia].
AB - The authors discuss the subjective and psychodynamic aspects of pharmacotherapy
in schizophrenia which are important for compliance. A large number of different
factors connected with psychopharmacotherapy are of particular importance when we
consider their impact on compliance. Those factors are psychopathology of
patient's disease, insight, and his her intrapsychic structure as well as the
great number of factors which are based on social and cultural environment of the
patient. One of the most important factors is associated with the patient's
family and the question how the family estimate the changes in the patient's
health under the influence of medication. Other important factors include those
which are rooted in the therapeutic environment of mental health service
institutions and particularly in the therapeutic relationship between the patient
and the treating psychiatrist. Those factors, including transference and counter
transference, may cause specific impact or even distortions ona
farmacotherapeutic action of the antipsychotic drugs. The attempts to classify
this compound area as well as some remarks concerning meaning of psychodynamic
aspects of farmacotherapy for different groups of mental health professionals are
presented in the article. The psychodynamic and subjective factors of
psychopharmacotherapy are seen here as a part of a more complex field of
compliance but also as those which determine a successful therapeutic outcome in
the care of schizophrenic patients.
PMID- 10786215
TI - [Clozapine withdrawal. A review].
AB - The article describes the symptoms of withdrawal of clozapine and their possible
causes as well as research on switching from clozapine to another antipsychotic
drug. A computerised search was conducted using MEDLINE (1966-1997) to retrieve
reports of clozapine withdrawal. Fifteen case reports and sixteen withdrawal
studies (only one of them double-blind and two single-blind) were identified.
Clozapine multi-receptors profile seems to be responsible for withdrawal symptoms
-several specific mechanisms are suggested: cholinergic supersensitivity,
dopaminergic supersensivity, special role of D4 receptors, possibilities of
serotonergic, noradrenergic and GABA-ergic involvement. Risk of relapse after
withdrawal of clozapine seems to be greater than after withdrawal of classical
neuroleptics. Some patients might become de novo neuroleptic resistant for at
least several weeks after withdrawal. Therefore, clozapine should be stopped only
due to strong clinical indications, and if only possible, the withdrawal should
be slow (50 mg/week). To prevent relapse of psychosis some experts advocate
starting new antipsychotic drugs in therapeutic dosage before withdrawal of
clozapine is completed. In case of emergency, when clozapine (high dosage) must
be withdrawn immediately, patient must be hospitalised and cholinergics might be
considered to prevent, cholinergic rebound". There are no established guidelines
which antipsychotic to choose after withdrawal of clozapine. In general,
classical antipsychotics are ineffective. Thioridazine is suggested because of
its prominent anticholinergic activity, but there is no clinical evidence of
advantage of this treatment in comparison to classical drugs. Risperidon and
especially olanzapine are promising possibilities, but initial data are
disappointing. Benzamides might be another possibility but clinical data are
scarce. These important issues require further studies.
PMID- 10786216
TI - [The risk of neuroleptic discontinuation in schizophrenia].
AB - The most effective method to maintain clinical improvement in the course of
schizophrenia is the continuation of neuroleptic therapy. Sometimes we face the
dilemma whether neuroleptic administration could be discontinued. There are some
unconditional indications for treatment cessation (signs of intolerance,
complications, general medical conditions); all other situations can be
considered as relative indications. The risk and benefit of treatment
discontinuation should be carefully evaluated. Neuroleptic withdrawal seems to be
safer among older patients, with single episode of the psychosis of mild
severity, with no family history of schizophrenia. It is necessary to achieve a
stable clinical improvement before neuroleptic withdrawal. Worsening of the
clinical status creates the most important risk of treatment discontinuation.
Other risk factors include unacceptable threatening behavior, increase of family
burden. The appearance of withdrawal symptoms such as nausea, vomiting,
dyskinesia, insomnia, anxiety, etc. are to be considered. These symptoms are
rare, and the risk of relapse is smaller when patients were treated with depot
neuroleptics before treatment discontinuation than in the case of treatment with
oral neuroleptics. Neuroleptic discontinuation and introduction of placebo cause
more risk of relapse than continuation of active treatment.
PMID- 10786217
TI - [Treatment of catatonic syndrome with fluoxetine. Case report].
AB - The case of catatonic syndrome in 34-years old male patient is described. The
patient's initial complaints regarded somatic distress. Previously, because of
persistence of somatic complaints and depressed mood, the patient was treated
with classic antidepressants with no clinical effect. Consequently, before
admission to our clinic, the patient received neuroleptic treatment without any
improvement. To our clinic he was referred as drug-resistant schizoaffective
psychosis. He was completely inactive, had hipochondriac delusions and blunted
affect. Further on, severe psychomotor inhibition and negativism prevailed.
Initial treatment with fluphenazine did not bring any clinical effect. Because of
presence of depressed mood and lack of activity, fluoxetine was administered
concomitantly with fluphenazine. After 8 weeks administration of fluoxetine 20 mg
daily showed substantial clinical improvement, especially in regard to the
patient's mood and activity. The dose of fluoxetine was increased to 40 mg daily,
and the patient was discharged from the clinic. The follow-up revealed that the
patient reassumed his professional career. He was still on fluoxetine 20 mg daily
and showed substantial clinical improvement. His overall tolerance of fluoxetine
20-40 mg daily was very good.
PMID- 10786218
TI - [CYP2D6 gene polymorphism in psychiatric patients resistant to standard
pharmacotherapy].
AB - The debrisoquine polymorphism is a genetic variation in oxidative drug metabolism
mediated by CYP2D6 gene, characterized by two phenotypes, the extensive
metabolizer (EM) and poor metabolizer (PM). PM phenotype is inherited as
autosomal recessive trait and occurs in 5-10% of Caucasian population. It is
associated with the inefficient metabolism of over 30 drugs, including many
psychotropic drugs. Clinical studies shown that PM are at higher risk than EM of
adverse reactions to these drugs. We genotyped 22 psychiatric patients in whom
standard pharmacotherapy had failed or drug adverse events occurred and in 14
patients in whom standard therapy was successful. CYP2D6 polymorphic alleles were
identified using allele specific nested PCR reaction. The PM genotype was found
in 4 of 22 (18%) patients resistant to standard pharmacotherapy and in none of 14
patients with improvement after standard therapy. Unsuccessful standard
psychotropic drugs therapy in psychiatric patients may be associated with PM
phenotype.
PMID- 10786219
TI - [Cortical atrophy in computerized tomography of the brain and clinical
characteristics of schizophrenia].
AB - The aim of this paper was searching for correlates of cortical atrophy in
schizophrenia. Schizophrenic patients with cortical prefrontal atrophy had more
negative symptoms than patients with generalized cortical atrophy and patients
without cortical atrophy (the difference was not statistically significant). They
also had less positive symptoms than patients without atrophy (the difference was
statistically significant) and patients with generalized cortical atrophy.
PMID- 10786220
TI - [A moment of reflection: dramatic path of Polish psychiatry].
AB - In the inauguration speech of the Congress stages of the path taken by the Polish
Psychiatric Society were described in short: 1--The period from its establishment
till 1939; 2--Tragic years of the war, 1939-1945, with extermination of ca.
20,000 patients and many psychiatrists; 3--Reconstruction after the war,
accompanied by the attempts to impose Soviet ideology, which induced finally
effective resistance and intense development of the science and practice.
PMID- 10786221
TI - [Polish paranoia].
AB - The article describes clinical experience with patients suffering from paranoid
states during adaptation to new country and culture. The complex of symptoms in
polish immigrants was called polish paranoia. It is a pathological way of coping,
resulting from new culture, ignorance of language, irrational expectations of
emigration profits. We think that reasons of this syndrome are polish nation
experiences, one's own history and family history.
PMID- 10786222
TI - [Medical student curriculum in psychiatry in Poland].
AB - The author describes present medical student curricula in psychiatry in Polish
medical schools based on the questionnaire sent to all the lecturers of the
subject in Poland. The questionnaire contained questions concerning the schedule
of lectures, seminars and classes (the list of topics) as well as the number of
hours of the forms of activities like interpersonal training, discussion groups,
internship, etc. We also asked on which year of studies the course in psychiatry
took place. The questionnaire included our request to describe the level of
integration of psychiatry and other pre-clinical and clinical subjects as well as
to enclose a recommended reading list (handbooks and other items of literature).
The last question dealt with the problem of assessment of lectures and classes by
students. The results of the questionnaire reveal great differences in the
curricula of psychiatry in various schools in Poland. The differences lie both in
the courses and the number of hours devoted to teaching psychiatry (in most
schools it was 120 hours or less). In 7 schools students learn psychiatry in the
6th i.e. the last year of their studies. In 2 schools lectures in psychiatry are
given in the th year. In Krakow and Gdansk the courses in psychiatry consist of
150 and 160 hours respectively. The author proposes unification of the curricula
in psychiatry concerning both the number of hours of classes and lectures, and
topics as well as introducing the diagnostic and classifying criteria ICD-10
(WHO) since Poland is going to join EU.
PMID- 10786223
TI - [Psychiatry in undergraduate training of physicians in Poland. Ideas and
reality].
AB - History of undergraduate training in psychiatry at medical schools in Poland was
briefly reviewed showing a traditional independence of chairpersons of psychiatry
in forming programmes and deciding about forms of education. Since 1990 this
independence has been controlled by the faculties and, to some extent only,
regulated by the national curriculum in medicine. Goals, contents and forms of
undergraduate training in psychiatry were examined (following Bilikiewicz's study
in 1994) with the author's own questionnaire. Professors of psychiatry,
respondents to the questionnaire were of very similar opinions in regard to the
goals of training. At the same time, meaningful differences were found in the
methods used, position of the subject in the curriculum and even time designed
for psychiatry training (at some schools below the national minimum). There were
also significant differences in the contents of the programme. The most important
problem seems to be absence of child and adolescent psychiatry at some schools.
Integration of psychiatry with other pre-clinical and clinical subjects was
assessed too. The information received suggests that Polish professors of
psychiatry approved of the way their subject had been integrated with others.
This seems to be overestimation, especially if compared with the Krakow
experience presented in a more detailed way.
PMID- 10786224
TI - [CDT (desialylated transferrin)--a new biochemical marker of alcohol abuse].
AB - Serum concentration of carbohydrate-deficient transferrin (CDT) is used for
laboratory diagnosis of chronic alcohol abuse. Several earlier studies reported
sensitivities of 90% or above for CDT, with a specificity of 90-100%, although
other investigators found lower sensitivities. In general, CDT has been reported
to be highly specific (92%) and relatively sensitive (80%) for the detection and
monitoring of alcoholism. There are no correlation between CDT concentration and
gamma-GT activity. Any alteration in serum total transferrin concentration
markedly decreases the CDT assay specificity. This should be considered when
interpreting the assay results in patients with elevated serum transferrin. There
are differences between the CDT isoforms (asialo-Tf and monosialo-Tf) in males
and females relative to alcohol consumption. Alcohol consumption increases the
levels of asialo-Tf and monosialo-Tf in women more strongly than in men.
Sensitivity of CDT assay is also related to age of patients. There is a
significantly higher sensitivity of CDT in patients above 40 years of age as
compared to younger patients. The measurement of carbohydrate-deficient
transferrin may be used as a marker of excessive alcohol abuse in patients with
liver diseases (also in cirrhosis). The specificity of CDT in patients with non
alcoholic liver disease was consistently higher than that of gamma-GT (80% vs
60%). Disulfiram therapy during detoxification does not influence the serum level
of CDT.
PMID- 10786225
TI - [Evaluation of psychomotor agility during the period of withdrawal symptom
dissipation in patients with alcohol dependence type 1 and 2 or Cloninger's].
AB - 28 alcohol dependent men were examined three times (on the 1st, 3rd or 4th and
7th day of withdrawal). The results confirmed the reported differences in the
course of withdrawal syndrome in type 1 and type 2 alcoholics. Patients with type
2 alcoholism had more pronounced psychophysiological and cognitive disturbances.
Tremor was more intensive in these patients and their reaction time was slower.
Also, impaired estimation of passing time lasted longer, but at the same time
their mood improved faster with the diminished intensity of withdrawal symptoms
than in patients with type 1 alcoholism. The results confirm the possibility of
diverse etiology in alcohol dependence.
PMID- 10786227
TI - [Interesting case of alcoholic psychotic disorder].
AB - In the paper a case of psychotic disorder connected with alcohol abuse is
presented. It is interesting because of its abundant symptomatology,
classification and typical chronology of events. Worth mentioning is also
coexistence of events that unambiguously show psychotic disorders comorbid with
those, which may be properly assessed only after objective data are obtained.
Case description is provided with appropriate comments.
PMID- 10786226
TI - [Use of urinary beta-hexosaminidase for diagnosing alcoholism in persons with
opiate dependency in a methadone substitution program].
AB - Usefulness of urinary beta-hexosaminidase determinations in patients on methadone
substitution to pinpoint cases of alcohol abuse was studied. It was found that
methadone, illegal drugs and HIV seropositivity had no effect upon the activity
of this enzyme. The enzyme activity was significantly higher in patients who
admitted to occasional heavy drinking than in those who declared abstinence (p =
0.014), and in healthy controls (p = 5*10(-8)), but still lower than in alcohol
dependent persons undergoing detoxification (p = 0.024). In the group of opiate
dependent persons in methadone substitution program the sensitivity of the test
was 87% and the specificity--80%.
PMID- 10786228
TI - [Psychoimmunology and disease based on certain research results].
AB - The paper presents the results of researches in psychoimmunology. This new
science creates an integrated model of man, and immunologic, endocrinological or
nervous systems are very closely connected with personality. The findings show
that health or disease depend on complex, psychophysiological mechanisms. Factors
very important for health are: genetic factor, personality, stress and coping,
economic and social situation, work, family, etc. The immunity unites with
personality, thinking, attitudes, emotions, whose kind, strength and adjustment
depend on the sense of coherence.
PMID- 10786229
TI - [Neuroborreliosis: a psychiatric problem?].
AB - The authors review the literature concerning clinical characteristics of
neuroborreliosis with special focus on mental disorders. The patients develop
mental disorders during the acute phase of the disease and even after several
years. These disorders are often accompanied with various neurological syndromes.
The authors discuss the most common mental disorders connected with
neuroborreliosis: encephalopathy, cognitive disorders, dementia, depression,
anxiety disorders. The paper describes the problem of neuroborreliosis in
psychiatry, especially in the endemic regions.
PMID- 10786230
TI - [Legal obligation to outpatient psychiatric treatment of mentally ill
perpetrators of crimes: necessity or restriction of liberty?].
AB - Considerations, concerning legal obligation to psychiatric treatment in case of
criminal offenders declared as insane by court, are presented in the paper.
Necessity of some changes in the legal system is pointed out. It is suggested
that, after preventive measures in the form of compulsory psychiatric
hospitalization, there should be a possibility of enforced out-patient treatment.
This should apply to persons who committed serious crimes (e.g. murder).
Suggestions contained in the paper are illustrated by a description of a
meaningful clinical case.
PMID- 10786231
TI - [Disturbances in interpersonal functioning and levels of anxiety, depression and
aggression in persons persecuted for political reasons in Poland in the years
1944-1956].
AB - The article presents the results of comparison of 30 victims of political
persecution in Poland in the years 1944-1956 (with a diagnosis of PTSD) with a
control group in regard to the styles of interpersonal functioning, anxiety,
depression and aggression. The examined persons manifest changes in the quality
of social contacts--increased results on the scales of hostility syndrome,
helplessness, and appeal for help, and decreased results on the scales examining
pro-social tendencies. The examined persons are characterized by low affiliation,
high level of indifference as well as features developed on the ground of
anxiety: lack of self-acceptance, suspiciousness, aggression and negative self
evaluation in comparison with others. They are also characterized by high level
of depression, readiness to react with fear or anxiety as the actual state during
examination. These categories determine the psychological results of injuries
suffered by the examined persons in the past.
PMID- 10786232
TI - [To cast a spell on reality. On actions of Soviet authorities in connection with
the 6th Congress of the World Psychiatric Association at Honolulu].
AB - At the 6th Congress of the World Psychiatric Association, held at Honolulu in
August 1977, its participants accepted by acclamation a--so called--"Hawaiian
Declaration" and a Resolution of the Royal College of Psychiatrists. The
Declaration condemned all kinds of abuse in psychiatry, and the Resolution
condemned the abuses in the Soviet psychiatry in particular. The Congress of
Honolulu carried out, at last, the action initiated at the Congress of Mexico
City six years earlier. But by then there was a lack of courage yet to take these
measures, and the counter-action of the Soviet authorities proved to be
effective. Aware of the fact that this time the pressure to condemn the misuses
practiced in the Soviet psychiatry would be ever stronger, the KGB and the
Ministry of Health of the USSR began their "preparations" for the next Congress
as early as in 1976. This article describes the tactics of action promoted by the
Soviet authorities in order to prevent the condemnation. The Author made a proper
use of some documents that he had recovered at the Moscow "Centre for Storing the
Contemporary Archives".
PMID- 10786234
TI - [The prevalence of dementia in old age].
AB - The risk of manifestation of dementia increases as the population grows older.
The prevalence of dementia increases from 0.7% in age group 60-64 years to 38.8%
in age group 90-94 years. Over 60, the prevalence rate doubles every 5.1 years.
The most common types of dementia are Alzheimer's dementia and vascular dementia.
PMID- 10786233
TI - [Trials and perspectives in pharmacotherapy of Alzheimer's disease].
AB - The paper discusses therapeutical approaches to Alzheimer's disease on the basis
of pathological mechanisms responsible for neurodegeneration. Amyloid plaques
called also senile plaques situated extracellularly cause loss of neurons,
especially cholinergic neurons, that begin in Nucleus of Meynert. However, recent
evidence from postmortem brain and fibroblast studies suggests that both adenylyl
cyclase and phosphatidylinositol hydrolysis signal transduction cascades are
disrupted in AD. Such disruption may limit cholinergic pharmacotherapy. Other
disorders, like disturbances in releasing Neuronal Growth Factor (NGF), oxidative
stress, free Ca 2+, neuroimmunologic reactions are also important in AD brain
changer. Only use of acetylcholine inhibitors: tacrine, donepezil and Gingko
Biloba as well as nimodipine improved mental functions (MMSE screening).
Neuroprotection of selegiline and NGF was observed. Behavioral symptoms often
associated with dementia, like depression, anxiety, irritability, delusions,
aggressiveness were treated with: olazepine, risperidone, haloperidol, clozapine,
fluoxetine, paroxetine, sertraline, trazodon, dezypramine, lithium,
benzodiazepines, carbamazepine and valproic acid. Drugs with strong
anticholinergic effects, such as amitriptyline or imipramine should not be
administered. Future studies on therapy to regulate metabolism of amyloid
precursor-beta-APP are necessary to discover new efficient strategies.
PMID- 10786235
TI - [The prevalence of dementia in the population of the Warsaw district of Mokotow
from 65 to 84 years of age].
AB - The aim of the two-phase population based study was to estimate the prevalence of
dementia. Among the population aged 65-84 years of the Warsaw district Mokotow,
the stratified sample consisted of 1,000 persons taken randomly. The first
screening phase (MMSE) was conducted by raters among 893 persons. 92 subjects
with disturbances of cognitive functions were qualified to the second-diagnostic
phase and 89 were given a diagnostic examination with the Cambridge Mental
Disorders of the Elderly Examination. The following age-specific prevalences of
dementia were found in the age-groups 65-69, 70-74, 75-79, 80-84: 1.9, 5.8, 8.6
and 16.5% respectively. Rates for vascular dementia (2.7) were higher than those
for dementia of the Alzheimer's type (2.3), mixed dementia (0.5), and secondary
dementia (0.2%). In the younger subgroups (65-74 y), vascular dementia was the
most frequent and in the older subgroups (75-84 y) the most frequent was
Alzheimer's type. The rates of dementia were quite similar to those found in
other European studies.
PMID- 10786236
TI - [Psychiatric rehabilitation in a secure treatment setting].
AB - Working with severely mentally ill persons within the locked environment of a
secure residential treatment facility presents a provocative challenge in
attempting to establish a rehabilitative program. The author describes the
mission, goals and methods of one of Oregon's newly organized facilities for
"hard to place" former state hospital patients. The value of teaching the
residents self-control is emphasized. Clinical vignettes illustrate how the staff
involve the residents in real-life tasks, apply natural consequences to problem
behaviors, and make attempts at minimizing the potential sources of
confrontation.
PMID- 10786237
TI - [Present views on pathogenesis of schizophrenia].
AB - Schizophrenia is recognized as a disorder of complex etiology including
biological and environmental factors. The paper describes, first of all,
biological abnormalities. It uses neurodevelopmental model assuming the existence
of neuropathological process. The process starts in the pre-natal period,
undergoes changes under the influence of developmental factors, and, finally,
manifests itself in psychotic symptoms. Particularly, the author suggests that
diathesis for schizophrenia involves functional excess of dopamine activity in
the basal ganglia. It causes disruption in neuronal circuits, thus releasing
psychotic symptoms. Additionally, the paper describes anatomic changes, neuronal
circuitry malfunctions and impairments in metabolic activity of brain detected in
numerous studies on schizophrenic patients.
PMID- 10786238
TI - [The study of candidates' genes in psychiatric diseases. I. Schizophrenia].
AB - The study concerning the importance of genetic factors in etiopathogenesis of
schizophrenia is presented below. In molecular genetics research there are two
most frequently applied strategies: searching of the whole genome in order to
find new genes; and molecular analysis of a candidate gene. Candidate gene
analysis consist in choosing a gene which could theoretically have a connection
with a given certain disease. The presented reference review includes the results
of study concerning candidate genes analysis referring to biochemical hypothesis
of schizophrenia. The aim of the study is to find changes at the level of
nucleotide sequence in DNA, which have a connection with the disease. It was
stated in many medical centres that in case of schizophrenia the polymorphism of
gene's receptor D3 and gene's receptor 5HT2A can be of etiological importance. It
was also proved that the clinical effect of clozapine could be connected with
polymorphism of gene's receptor 5HT2A.
PMID- 10786239
TI - [Disorders in cognition and language vs. communication deviances in families of
schizophrenics].
AB - This paper shortly reviews the findings of studies about cognitive and language
dysfunctions in schizophrenic patients and their parents. It also presents the
main concepts about communication deficits in families of schizophrenics--double
bind, communication deviance, egocentric communication, disconfirmatory feedback
and some aspects of expressed emotion. The influences and relationships between
cognition, language and communication are emphasised. There are also some
suggestions about the treatment.
PMID- 10786240
TI - [Assessment of ability to transmit and receive information in schizophrenics and
their mothers].
AB - The cloze procedure was used to examine: predictability in speech samples from
schizophrenics and their mothers as well as their ability to gain from the
redundancy of language. Schizophrenic patients were found to be less predictable
than normals, both schizophrenics and their mothers were less able to make use of
the language context than controls did. The impact of disturbances in information
processing on the family interactions was considered.
PMID- 10786241
TI - [Catatonic syndrome and neuroleptic malignant syndrome].
AB - Several clinical reports suggest that neuroleptic malignant syndrome (NMS) is not
a distinct clinical entity but an acute form of catatonic syndrome (CS). They
both share many clinical features and it is impossible to differentiate them on
the basis of biochemical findings. Both respond similarly to treatment. The
article describes some case reports from the literature and our own case report
of NMS as a form of CS.
PMID- 10786243
TI - [The costs of treatment and rehabilitation of long-term psychiatric patients].
AB - The cost of treatment of mentally ill patients is taking an ever more important
place in the health care systems of many countries. This is caused by an
increasing interest of the taxpayers who want to know where their money goes in
relation to medical expenses. It is logical that taxpayers' expectations include
improvement of the health care system. Medicine cannot be considered in the
category of a profit making economy because some of the fields of medicine are
not and cannot be profitable. At the borderline between economy and medicine,
pharmaco-economy was born. This new science considers the cost of treatment of
various sicknesses; furthermore it tests the comparative costs and the use of
pharmaceutical products. In pharmaco-economy we distinguish three different types
of costs: the continuous cost (consequent to medical treatment), the indirect
cost (related to losses on support of patients and their family members), the
unassessable cost (psychological losses). A correct economical analysis is multi
factual and refers to different sides of our lives. With this understanding we
can only consider the general economical results, that is, the so called
"economical treatment result". It is believed that this way of thinking can cause
an intensive development in the rehabilitation of chronic mentally ill patients
in Poland. This rehabilitation can be a classical example of modern economy:
hypothetically high initial costs cause their substantial reduction in the
progressive development of the programme until they reach their effective
reduction at the end, i.e. the progressive improvement of the patients
functioning within their natural environment.
PMID- 10786242
TI - [The role of health insurance in mental health care in Germany].
AB - An outline of the German system of mental health care is given. A description of
its organization, funding streams and service set-up is provided. Strengths and
weaknesses are highlighted, and the system is contrasted with the organisation of
mental health care in England and Wales.
PMID- 10786244
TI - [Community specialized social help services for patients with mental disorders:
one year experience].
AB - This article describes one year's experiences of Foundation of Supporting
Psychiatric Department Medical Academy of Warsaw in care of patients with mental
disorders in two districts of Warsaw. The service was provided for open group of
about 70-80 patients with the diagnosis of schizophrenia and depressive disorder
recurrent. Introducing of this type of care resulted in reducing of the number of
patient admitted to the hospital and in shortening of the mean hospitalization
time. Moreover, last but not least, improved patient's life quality. The article
contains also care reports illustrations successes and defeats in this type of
care.
PMID- 10786245
TI - [The diagnostic questionnaires and their use in epidemiological studies in
psychiatry].
AB - The paper presents diagnostic instruments employed in psychiatric; brief history
of their development with regard to their importance for progress in psychiatric
epidemiology, the characteristic of the most important diagnostic questionnaire
(Present State Examination--PSE, Composite International Diagnostic Interview-
CIDI, Schedules for Clinical Assessment In Neuropsychiatry--SCAN, Structured
Clinical Interview for DSM IV--SCID, Schedule for Affective Disorders and
Schizophrenia--SADS, Diagnostic Interview Schedule--DIS). It also describes some
features that should be considered while choosing a proper instrument for a given
study. The authors call attention to some differences between instruments, e.g.,
those related to the structure of the questionnaire, involving diagnostic
categories, the sort of information that an instrument allows to collect,
competence of interviewers and their training, and also population for which the
instrument is assigned. Presenting advantages and disadvantages of instruments,
the authors emphasize that there is no best instrument. The choice of
questionnaire depends, first of all, on the purpose of the study and the funds
that the researches have at their disposal.
PMID- 10786247
TI - [The study of candidate genes in psychiatric disease. II. Affective disorders].
AB - The results of research concerning the importance of genetic factors in
etiopathogenesis of affective diseases are presented. In molecular genetics
research there are two most frequently applied strategies: searching of the whole
genome in order to find new genes and molecular analysis of candidate genes.
Candidate gene analysis consist in choosing a gene which could theoretically have
a connection with the disease. The polymorphism of a chosen gene is estimated and
then its connection with the disease is defined. The presented reference review
concerns the results of candidate genes research, which refer to biochemical
hypothesis of affective diseases. In many medical centers it was found that in
affective disorders the polymorphism of gene's receptor D4, GABA and serotonin
transporter could be of etiological importance.
PMID- 10786246
TI - [Epidemiological studies on neurotic disturbances, anxiety and depression
disorders in a population living near an overhead high voltage transmission line
(400 kV)].
AB - Epidemiological studies indicate an increased incidence of depression and
neurotic disorders in persons long exposed to influence of electromagnetic
fields. The examinations covered a selected population of several suburban
neighborhoods of Cracow living not farther than 50 m from a 400 kV high-voltage
transmission line. A group of 70 persons (35 men and 35 women) living near the
transmission line for longer than 10 years was examined. A control group
consisted of 37 persons not subjected to an influence of similar transmission
line. Instruments used in the examination included: Symptom Checklist "0",
Spielberge's Self-assessment Questionnaire and Beck's Inventory. Also, a modified
life-history questionnaire was applied. In the examined households we found
significantly increased values of intensity of the electric component (by the so
called "ecological" Swedish norms). The population resident in the closest
neighborhood of the examined transmission-line manifested high level of
psychopathology, significantly different than that in the control group. However,
the obtained results do not allow us to state univocally whether the observed
psychopathology remains in causal nexus with the exposure to electromagnetic
field. Other factors, like noise, may also be responsible for these results. The
hypothesis that electromagnetic fields generated by high-voltage transmission
lines may evoke depressive disorders and depression requires further clinical and
experimental studies.
PMID- 10786248
TI - [Children and parental depression. An investigation on adult offspring of
depressed patients].
AB - The aim of our study was to assess the perception of parental depression by their
adult offspring. Twenty nine offsprings aged 22.5 +/- 3.9 years were examined
with the use of Parental Bonding Instrument, Beck Depression Inventory, Resenberg
Scale, Hopelessness Scale, Automatic Thoughts Questionnaire and our own
semistructured inventory. The offsprings of depressed patients reported negative
impact of the illness on various aspects of life, especially when mother was ill.
Surprisingly, the offsprings did not reveal disturbances in their thinking style,
neither did they have depressive symptoms.
PMID- 10786249
TI - [Religiosity and intensity of endogenous depression symptoms. A follow-up study].
AB - The aim of our study was to determine if the quality of remission in unipolar
affective disorder correlates with patient's religiosity. We have investigated 63
patients who were hospitalised in the Department of Psychiatry CMUJ between 1991
and 1997. The quality of remission has been assessed by Beck Depression Inventory
(BDI), Rosenberg Self-esteem Scale (RS), Automatic Thoughts Questionnaire (ATQ),
Hopelessness Scale (HS). Religiosity has been tested by the Scale of Individual
Religiosity, and Religious Life Inventory. Patients were also assessed with the
use of our own questionnaire, answering the following questions: 1. Do you
believe?, 2. Does the disease influence the faith?, 3. Does your faith help in
the disease?. Religiosity did not correlate with the quality of remission in
depression in a statistically significant manner. There is only one statistically
significant correlation: patients who answered positively the question number 3
(41 patients), have better remission. It is impossible to describe simple
correlation between religiosity and remission in unipolar affective disorder.
Patients who found their faith helpful have better remission.
PMID- 10786250
TI - [Regional cerebral blood flow in depression].
AB - In the review article, the results of studies on regional cerebral blood flow
(rCBF) in major depression are presented. Most studies have reported global and
regional deficits in cerebral blood flow in major depression as compared to
healthy controls. Longitudinal studies show that after recovery from depression
an increase of CBF has been observed. The influence of different biological
treatment methods on rCBF is also discussed. Findings regarding lateral
asymmetries of cerebral function in patients with major depression are
inconclusive but the deficit of rCBF is often more pronounced in the left
hemisphere. The nature of regional brain flow abnormalities in depression is
unclear. Structural changes of the brain and biochemical abnormalities are under
consideration.
PMID- 10786251
TI - [Tomographic cerebral blood flow scanning in diagnosis of psychiatric disorders].
AB - The paper summarises the role of tomographic cerebral blood flow SPECT scanning
in psychiatric diagnostics, its' physical and radiopharmaceutical basis,
pathological physiology of cerebrovascular circulation in psychiatric disorders
and interpretation of cerebral blood flow scanning results by the clinician.
Cerebral blood flow scanning is, to some extent, a functional equivalent of
CT/MRI scanning. In psychiatry cerebral blood flow SPECT scanning's basic
application is the differentiation of dementia and cognitive impairment, in
particular Alzheimer's disease, frontotemporal lobar degeneration and multi
infarct dementia. The other indications for brain SPECT scanning involve the
organic brain lesions and medico-legal diagnostics, including the sequelae of
cranio-cerebral trauma. Contraindications and economical aspects are underlined.
PMID- 10786252
TI - [Clomipramine in the treatment of obsessive-compulsive disorder. An open 8-week
trial].
AB - Among many drugs used for treatment of obsessive-compulsive disorder clomipramine
is still considered as model drug though serotoninergic mechanism is common for
many antidepressants. The study was carried out in order to assess the potential
and dynamic of antiobsessive and anticompulsive efficacy of clomipramine used in
normal therapeutic doses during eight week trial. The study was carried out with
the help of Asta Medica company and trade name of the used drug was Hydiphen. The
severity of obsessive-compulsive disorder was evaluated at the moment of
inclusion to the study and then once every week. The obsessive-compulsive scale Y
BOCS was employed. 27 patietnts (16 women and 11 men) at aged 18-64, from
different mental health care centers in Poland participated in this study. The
study was completed by 67% of patients--due to lack of therapeutical effect the
treatment of others patients was stopped. Among the patients who responded well
to clomipramine therapy, improvement was observed after the first week and then
the dynamic of improvement decreased after 4 weeks. During the 7th week the drug
reached its maximal efficacy level with statistically significant reduction in
scores of Y-BOCS scale. The range of therapeutic doses was 75-250 mg. In this
range no seriouse adverse events were observed and some of mild ones that
occurred at the beginning of the therapy diminished during the next week.
PMID- 10786253
TI - Doxazosin dropped from ALLHAT study.
PMID- 10786254
TI - PBMs could manage Medicare drug benefit but need flexibility, guidelines.
PMID- 10786256
TI - Report compares treatments for stable angina.
PMID- 10786255
TI - Study documents benefits of beta-blockers in heart failure.
PMID- 10786257
TI - Psychotropic drug use rising among preschoolers.
PMID- 10786258
TI - CDC alters recommendations on rifamycin-antiretroviral drug use.
PMID- 10786259
TI - Candesartan cilexetil: an angiotensin II-receptor blocker.
AB - The mechanism of action, pharmacokinetics, pharmacodynamics, clinical efficacy,
and adverse effects of candesartan cilexetil are reviewed. Candesartan is an
angiotensin II-receptor blocker (ARB). It is administered as a pro-drug that
undergoes activation during gastrointestinal absorption. The agent is excreted
mostly unchanged and has a terminal half-life of about nine hours (slightly
longer in the elderly). Candesartan differs from other agents in its class in
that it is tightly bound to angiotensin II type 1 receptors, allowing prolonged
activity. In clinical trials, candesartan cilexetil has produced a dose-dependent
effect when given in dosages of 2-32 mg/day. Observed trough-to-peak blood
pressure ratios support a once-daily dosage regimen. The antihypertensive effect
of candesartan cilexetil 4-16 mg/day was as great as that of enalapril 10-20
mg/day and amlodipine 5 mg/day and larger than that of losartan potassium 50
mg/day. Adding candesartan cilexetil to hydrochlorothiazide 12.5-25 mg/day and
amlodipine 5 mg/day led to enhanced blood-pressure reductions and was well
tolerated. It appears that candesartan can decrease renal perfusion without
adversely affecting renal blood flow and may mediate a decrease in albuminuria in
hypertensive patients with type 2 diabetes. No clinically important drug
interactions have been reported. Adverse effects include headache, dizziness,
nausea, diarrhea, and transient elevations in liver transaminases. The frequency
of cough is similar to that seen with placebo. Candesartan cilexetil is an
effective antihypertensive agent that can be used alone or in combination with
other antihypertensive drugs. It is generally well tolerated and may be an option
for patients who cannot tolerate angiotensin-converting-enzyme inhibitors because
of cough.
PMID- 10786260
TI - Community pharmacist outreach program directed at physicians treating congestive
heart failure.
AB - The predictive value of digoxin and furosemide treatment for identifying patients
receiving treatment for congestive heart failure (CHF), the use of angiotensin
converting-enzyme (ACE) inhibitors in this population, and the ability of a
pharmacist outreach program to address underutilization of ACE inhibitors were
studied. All physicians and owner-managers of community pharmacies on
Newfoundland's Avalon Peninsula were asked to participate in the study.
Pharmacists who agreed to participate were asked to list patients of the
participating physicians with prescriptions for (1) furosemide and digoxin with
and without an ACE inhibitor or angiotensin II-receptor inhibitor and (2) an ACE
inhibitor. Physicians were visited by a pharmacist and asked whether each of
their patients receiving digoxin and furosemide was being treated for CHF and to
identify further cases of CHF among their patients receiving an ACE inhibitor.
Intervention-group physicians received academic detailing on the use and dosage
of ACE inhibitors and angiotensin II-receptor inhibitors for CHF. Both groups
were reinterviewed after three months to establish what if any changes in therapy
had occurred for each patient discussed during the first visit. The positive
predictive value of digoxin and furosemide treatment for identifying patients
receiving treatment for CHF was 94%. Seventy-six percent of patients identified
by physicians as CHF patients who were taking digoxin and furosemide were treated
with an ACE inhibitor. Thirty-six percent of patients treated with an ACE
inhibitor for CHF received the targeted dosage. Four physicians stated that the
outreach visit influenced their prescribing, but there was no significant
difference in ACE inhibitor prescribing between the intervention and control
groups. A pharmacist outreach program involving the use of prescription records
and academic detailing did not affect prescribing or dosages of ACE inhibitors
but demonstrated value as a quality assurance tool.
PMID- 10786262
TI - Refill program using pharmacy student interns in a primary care clinic.
PMID- 10786261
TI - Economics of using pharmacists as advisers to physicians in risk-sharing
contracts.
AB - An educational program designed to help physicians control the overall cost of
drugs and total health care is described, along with its effectiveness at one
managed health care plan. Prime Therapeutics, Inc., developed and manages an
ongoing physician education program designed to help primary care physicians
control drug and total health care costs. Physician education initiatives in the
program are developed by using peer-reviewed literature; selections of preferred
drugs are based on evidence of their safety, efficacy, uniqueness, and cost
effectiveness. For a typical educational initiative, a pharmacist meets with the
physicians identified as being among the top 20% of prescribers of high-cost
drugs addressed by the initiative and delivers a 20-minute presentation. One-on
one meetings with the physicians are then held quarterly to review their
prescribing. Each physician is shown comparisons with the prescribing patterns of
other physicians in the organization. The clinic chooses to present the
clinicwide data as either blinded or nonblinded data. The program was evaluated
by comparing per member per month (PMPM) total health care and drug costs for
1996 and 1997 at 12 general medicine clinics in a managed health care plan. Five
clinics received no interventions, three clinics allowed the initial presentation
and the quarterly face-to-face meetings, and four clinics allowed only the
presentation and barred ongoing meetings. In general, the clinics with more
interaction between pharmacists and physicians had lower PMPM costs for total
health care and drugs than the clinics with less interaction. Pharmacists acting
as advisers to primary care physicians in general medicine clinics helped lower
PMPM costs for drugs and total health care.
PMID- 10786263
TI - Activity of dalteparin sodium in polypropylene syringes.
PMID- 10786264
TI - Survey of home infusion care in England.
PMID- 10786265
TI - Patient education role of a pharmacist on a transplant service.
PMID- 10786266
TI - More than a matter of law enforcement.
PMID- 10786267
TI - [Severe exacerbation of asthma].
PMID- 10786268
TI - [Acute respiratory failure in chronic obstructive pulmonary disease].
PMID- 10786269
TI - [Thoracic injuries].
PMID- 10786270
TI - [Acute respiratory distress].
PMID- 10786271
TI - [Hemodynamically unstable pulmonary thromboembolism].
PMID- 10786272
TI - [Respiratory failure in scuba diving].
PMID- 10786273
TI - [Fibrinolysis in pleural effusion].
PMID- 10786274
TI - [Bronchoscopy emergencies].
PMID- 10786275
TI - [Interventional radiologic techniques in thoracic emergencies].
PMID- 10786276
TI - [Laryngotracheobronchial injuries].
PMID- 10786277
TI - Characterization of a generic monoclonal antibody harvesting system for
adsorption of DNA by depth filters and various membranes.
AB - The physical parameters governing adsorption of DNA by various positively charged
depth filters and membranes have been assessed. Buffers that reduced or
neutralised the depth filter or membrane charge, and those that impeded
hydrophobic interactions were shown to affect their operational capacity,
demonstrating that DNA was adsorbed by a combination of electrostatic and
hydrophobic interactions. The adsorption profile of DNA by a Sartobind Q anion
exchange membrane showed immediate breakthrough, irrespective of challenge DNA
concentration or flow rate, and in this case adsorption was by electrostatic
interactions only. The production-scale removal of DNA from harvest broths
containing therapeutic protein by partitioning of cells and debris from protein
in sequential centrifugation and filtration steps, and the concentration of DNA
in process supernatant were assessed. Centrifugation reduced the quantity of DNA
in the process material from 79.8 micrograms ml-1 to 9.3 micrograms ml-1 whereas
the concentration of DNA in the supernatant of pre- and post-filtration samples
had only marginally reduced DNA content: from 6.3 to 6.0 micrograms ml-1
respectively. DNA was concentrated to 27.3 micrograms ml-1 along with monoclonal
antibody in the ultrafiltration step. Similar effects were observed in the
harvest step for a second antibody.
PMID- 10786279
TI - Purification of Lac repressor protein using polymer displacement and
immobilization of the protein.
AB - Lac repressor protein was purified from E. coli BMH8117 harboring plasmid pWB1000
and E. coli K12BMH 71-18 strains. Displacement of the protein with
poly(ethyleneimine) (PEI) from phosphocellulose cation exchange column was shown
to be an effective elution strategy. It resulted in better recoveries and sharper
elution profiles than traditional salt elution without effecting the purity of
the protein. The elution is assumed to proceed via displacement of bound protein
by PEI when the polymer binds to the ion exchanger. The minor impurities in the
protein solution were finally removed by chromatography on immobilized metal
affinity column. The repressor protein undergoes distinct conformational changes
upon addition of specific inducer isopropyl-beta-D-thiogalactoside (IPTG), which
is evidenced by changes in ultraviolet absorption spectrum. The protein was
immobilized covalently to the Sepharose matrix. The intact biological activity of
the protein after immobilization was shown by binding of genomic DNA and lac
operator plasmid DNA from E. coli to the immobilized lac repressor.
PMID- 10786278
TI - Purification of alpha-glucosidae and invertase from bakers' yeast on modified
polymeric supports.
AB - In the present work Amberlite XAD-16 and Indion NPA-1, Polystyrene Divinylbenzene
macroreticular spherical resins, have been evaluated quantitatively as supports
for the adsorption and isolation of the yeast proteins and the enzymes, invertase
and alpha-glucosidase. Modification of these supports has been carried out by
surface grafting using acrylate polymers to reduce the hydrophobicity and
nonspecific adsorption of proteins. Good grafting efficiency, in excess of 90%,
has been obtained using ultrasonic irradiation for the surface activation of
polystyrene resins. XAD-16 has higher adsorption capacities for the total yeast
proteins as well as for both the enzymes, alpha-glucosidase and invertase, than
NPA-1 in its respective native and grafted form. Adsorption capacities of XAD-16
and NPA-1 in their respective native and grafted forms for alpha-glucosidase are
higher than the capacities for invertase. Nonspecific adsorption of total
proteins has been reduced considerably after the grafting of acrylate polymers on
hydrophobic supports. At the same time selectivity for the adsorption of both the
enzymes has been enhanced on grafted supports. The overall solid-liquid
adsorption mass transfer coefficient values (Kla) estimated for adsorption of
invertase on XAD are lower than those for alpha-glucosidase. Native and grafted
resins could be regenerated and reused for adsorption of alpha-glucosidase for
two regeneration cycles studied. Storage stability of invertase and alpha
glucosidase is the same on native and grafted form of XAD-16 and is more than the
enzymes in the free form.
PMID- 10786280
TI - Crystallographic threading.
AB - Crystallographic studies play a major role in current efforts towards protein
structure determination. Despite recent advances in computational tools for
molecular modeling and graphics, the construction of a three-dimensional protein
backbone model from crystallographic data remains complex and time-consuming.
This paper describes a unique contribution to an automated approach to protein
model construction and evaluation, where a model is represented as an annotated
trace (or partial trace) of a structure. Candidate models are derived through a
topological analysis of the electron density map of a protein. Using sequence
alignment techniques, we determine an optimal threading of the known sequence
onto the candidate protein structure models. In this threading, connected nodes
on the model are associated with adjacent amino acids in the sequence and a
fitness score is assigned based on features extracted from the electron density
map for the protein. Experimental results demonstrate that crystallographic
threading provides an effective means for evaluating the "goodness" of
experimentally derived protein models.
PMID- 10786281
TI - A phylogenetic approach to RNA structure prediction.
AB - Methods based on the Mutual Information statistic (MI methods) predict structure
by looking for statistical correlations between sequence positions in a set of
aligned sequences. Although MI methods are often quite effective, these methods
ignore the underlying phylogenetic relationships of the sequences they analyze.
Thus, they cannot distinguish between correlations due to structural
interactions, and spurious correlations resulting from phylogenetic history. In
this paper, we introduce a method analogous to MI that incorporates phylogenetic
information. We show that this method accurately recovers the structures of well
known RNA molecules. We also demonstrate, with both real and simulated data, that
this phylogenetically-based method outperforms standard MI methods, and improves
the ability to distinguish interacting from non-interacting positions in RNA.
This method is flexible, and may be applied to the prediction of protein
structure given the appropriate evolutionary model. Because this method
incorporates phylogenetic data, it also has the potential to be improved with the
addition of more accurate phylogenetic information, although we show that even
approximate phylogenies are helpful.
PMID- 10786283
TI - Position-specific annotation of protein function based on multiple homologs.
AB - I present in this work an algorithm for deriving protein functional annotations
which are position-specific. The input is based on the results of a sequence
similarity search of the query sequence against a sequence database. Strings of
words are extracted from the descriptions of the proteins, and the correlation
between proteins having the same descriptors and the amino acid conservation is
used to compute a score that indicates which descriptor is likely to describe
better the function of each particular residue. Analysis of the score curves and
comparison of different functions allows an easy detection of parts of the
sequence associated to different function. Different levels of functional
specificity can be compared, allowing to choose the one that suits better the
function of the protein. Immediate applications of this algorithm are, support
for (automated) methods of protein functional annotation, and database coherence
check.
PMID- 10786282
TI - Genomics via optical mapping. III: Contiging genomic DNA.
AB - In this paper, we describe our algorithmic approach to constructing an alignment
of (contiging) a set of restriction maps created from the images of individual
genomic (uncloned) DNA molecules digested by restriction enzymes. Generally,
these DNA segments are sized in the range of 1-4 Mb. The goal is to devise
contiging algorithms capable of producing high-quality composite maps rapidly and
in a scaleable manner. The resulting software is a key component of our physical
mapping automation tools and has been used to create complete maps of various
microorganisms (E. coli, P. falciparum and D. radiodurans). Experimental results
match known sequence data.
PMID- 10786284
TI - Nearest neighbor classification in 3D protein databases.
AB - In molecular databases, structural classification is a basic task that can be
successfully approached by nearest neighbor methods. The underlying similarity
models consider spatial properties such as shape and extension as well as
thematic attributes. We introduce 3D shape histograms as an intuitive and
powerful approach to model similarity for solid objects such as molecules. Errors
of measurement, sampling, and numerical rounding may result in small
displacements of atomic coordinates. These effects may be handled by using
quadratic form distance functions. An efficient processing of similarity queries
based on quadratic forms is supported by a filter-refinement architecture.
Experiments on our 3D protein database demonstrate the high classification
accuracy of more than 90% and the good performance of the technique.
PMID- 10786285
TI - Reconstructing the duplication history of a tandem repeat.
AB - One of the less well understood mutational transformations that act upon DNA is
tandem duplication. In this process, a stretch of DNA is duplicated to produce
two or more adjacent copies, resulting in a tandem repeat. Over time, the copies
undergo additional mutations so that typically, multiple approximate tandem
copies are present. An interesting feature of tandem repeats is that the
duplicated copies are preserved together, making it possible to do "phylogenetic
analysis" on a single sequence. This involves using the pattern of mutations
among the copies to determine a minimal or a most likely history for the repeat.
A history tries to describe the interwoven pattern of substitutions, indels, and
duplication events in such a way as to minimize the number of identical mutations
that arise independently. Because the copies are adjacent and ordered, the
history problem can not be solved by standard phylogeny algorithms. In this
paper, we introduce several versions of the tandem repeat history problem,
develop algorithmic solutions and evaluate their performance. We also develop
ways to visualize important features of a history with the goal of discovering
properties of the duplication mechanism.
PMID- 10786286
TI - Identity by descent genome segmentation based on single nucleotide polymorphism
distributions.
AB - In the course of our efforts to build extended regions of human genomic sequence
by assembling individual BAC sequences, we have encountered several instances
where a region of the genome has been sequenced independently using reagents
derived from two different individuals. Comparing these sequences allows us to
analyze the frequency and distribution of single nucleotide polymorphisms (SNPs)
in the human genome. The observed transition/transversion frequencies are
consistent with a biological origin for the sequence discrepancies, and this
suggests that the data produced by large sequencing centers are accurate enough
to be used as the basis for SNP analysis. The observed distribution of single
nucleotide polymorphisms in the human genome is not uniform. An apparent
duplication in the human genome extending over more than 130 kb between
chromosomes 1p34 and 16p13 is reported. Independently derived sequences covering
these regions are more than 99.9% identical, indicating that this duplication
event must have occurred quite recently. FISH mapping results reported by the
relevant laboratories indicate that the human population may be polymorphic for
this duplication. We present a population genetic theory for the expected
distribution of SNPs and derive an algorithm for probabilistically segmenting
genomic sequence into regions that are identical by descent (IBD) between two
individuals based on this theory and the observed locations of polymorphisms.
Based on these methods and a random mating model for the human population,
estimates are made for the mutation rate in the human genome.
PMID- 10786287
TI - Automatic extraction of biological information from scientific text: protein
protein interactions.
AB - We describe the basic design of a system for automatic detection of protein
protein interactions extracted from scientific abstracts. By restricting the
problem domain and imposing a number of strong assumptions which include pre
specified protein names and a limited set of verbs that represent actions, we
show that it is possible to perform accurate information extraction. The
performance of the system is evaluated with different cases of real-world
interaction networks, including the Drosophila cell cycle control. The results
obtained computationally are in good agreement with current biological knowledge
and demonstrate the feasibility of developing a fully automated system able to
describe networks of protein interactions with sufficient accuracy.
PMID- 10786288
TI - A data base of minimally frustrated alpha helical segments extracted from
proteins according to an entropy criterion.
AB - A data base of minimally frustrated alpha helical segments is defined by
filtering a set comprising 822 non redundant proteins, which contain 4783 alpha
helical structures. The data base definition is performed using a neural network
based alpha helix predictor, whose outputs are rated according to an entropy
criterion. A comparison with the presently available experimental results
indicates that a subset of the data base contains the initiation sites of protein
folding experimentally detected and also protein fragments which fold into stable
isolated alpha helices. This suggests the usage of the data base (and/or of the
predictor) to highlight patterns which govern the stability of alpha helices in
proteins and the helical behavior of isolated protein fragments.
PMID- 10786289
TI - Constructing biological knowledge bases by extracting information from text
sources.
AB - Recently, there has been much effort in making databases for molecular biology
more accessible and interoperable. However, information in text form, such as
MEDLINE records, remains a greatly underutilized source of biological
information. We have begun a research effort aimed at automatically mapping
information from text sources into structured representations, such as knowledge
bases. Our approach to this task is to use machine-learning methods to induce
routines for extracting facts from text. We describe two learning methods that we
have applied to this task--a statistical text classification method, and a
relational learning method--and our initial experiments in learning such
information-extraction routines. We also present an approach to decreasing the
cost of learning information-extraction routines by learning from "weakly"
labeled training data.
PMID- 10786290
TI - INTERACT: an object oriented protein-protein interaction database.
AB - MOTIVATION: Protein-protein interactions provide vital information concerning the
function of proteins, complexes and networks. Currently there is no widely
accepted repository of this interaction information. Our aim is to provide a
single database with the necessary architecture to fully store, query and analyse
interaction data. RESULTS: An object oriented database has been created which
provides scientists with a resource for examining existing protein-protein
interactions and inferring possible interactions from the data stored. It also
provides a basis for examining networks of interacting proteins, via analysis of
the data stored. The database contains over a thousand interactions. CONTACT:
k.eilbeck@stud.man.ac.uk
PMID- 10786291
TI - Using sequence motifs for enhanced neural network prediction of protein distance
constraints.
AB - Correlations between sequence separation (in residues) and distance (in Angstrom)
of any pair of amino acids in polypeptide chains are investigated. For each
sequence separation we define a distance threshold. For pairs of amino acids
where the distance between C alpha atoms is smaller than the threshold, a
characteristic sequence (logo) motif, is found. The motifs change as the sequence
separation increases: for small separations they consist of one peak located in
between the two residues, then additional peaks at these residues appear, and
finally the center peak smears out for very large separations. We also find
correlations between the residues in the center of the motif. This and other
statistical analysis are used to design neural networks with enhanced performance
compared to earlier work. Importantly, the statistical analysis explains why
neural networks perform better than simple statistical data-driven approaches
such as pair probability density functions. The statistical results also explain
characteristics of the network performance for increasing sequence separation.
The improvement of the new network design is significant in the sequence
separation range 10-30 residues. Finally, we find that the performance curve for
increasing sequence separation is directly correlated to the corresponding
information content. A WWW server, distanceP, is available at
http://www.cbs.dtu.dk/services/distanceP/.
PMID- 10786292
TI - Protein fold class prediction: new methods of statistical classification.
AB - Feed forward neural networks are compared with standard and new statistical
classification procedures for the classification of proteins. We applied logistic
regression, an additive model and projection pursuit regression from the methods
based on a posterior probabilities; linear, quadratic and a flexible discriminant
analysis from the methods based on class conditional probabilities, and the K
nearest-neighbors classification rule. Both, the apparent error rate obtained
with the training sample (n = 143) and the test error rate obtained with the test
sample (n = 125) and the 10-fold cross validation error were calculated. We
conclude that some of the standard statistical methods are potent competitors to
the more flexible tools of machine learning.
PMID- 10786293
TI - Fidelity probes for DNA arrays.
AB - One current approach to quality control in DNA array manufacturing is to
synthesize a small set of test probes that detect variation in the manufacturing
process. These fidelity probes consist of identical copies of the same probe, but
they are deliberately manufactured using different steps of the manufacturing
process. A known target is hybridized to these probes, and those hybridization
results are indicative of the quality of the manufacturing process. It is not
only desirable to detect variations, but also to analyze the variations that
occur, indicating in what process step the manufacture changed. We describe a
combinatorial approach which constructs a small set of fidelity probes that not
only detect variations, but also point out the manufacturing step in which a
variation has occurred. This algorithm is currently being used in mass-production
of DNA arrays at Affyetrix.
PMID- 10786294
TI - Solving large scale phylogenetic problems using DCM2.
AB - In an earlier paper, we described a new method for phylogenetic tree
reconstruction called the Disk Covering Method, or DCM. This is a general method
which can be used with any existing phylogenetic method in order to improve its
performance. We showed analytically and experimentally that when DCM is used in
conjunction with polynomial time distance-based methods, it improves the accuracy
of the trees reconstructed. In this paper, we discuss a variant on DCM, that we
call DCM2. DCM2 is designed to be used with phylogenetic methods whose objective
is the solution of NP-hard optimization problems. We show that DCM2 can be used
to accelerate searches for Maximum Parsimony trees. We also motivate the need for
solutions to NP-hard optimization problems by showing that on some very large and
important datasets, the most popular (and presumably best performing) polynomial
time distance methods have poor accuracy.
PMID- 10786295
TI - TEXTAL: a pattern recognition system for interpreting electron density maps.
AB - X-ray crystallography is the most widely used method for determining the three
dimensional structures of proteins and other macromolecules. One of the most
difficult steps in crystallography is interpreting the electron density map to
build the final model. This is often done manually by crystallographers and is
very time-consuming and error-prone. In this paper, we introduce a new automated
system called TEXTAL for interpreting electron density maps using pattern
recognition. Given a map to be modeled, TEXTAL divides the map into small regions
and then finds regions with a similar pattern of density in a database of maps
for proteins whose structures have already been solved. When a match is found,
the coordinates of atoms in the region are inferred by analogy. The key to making
the database lookup efficient is to extract numeric features that represent the
patterns in each region and to compare feature values using a weighted Euclidean
distance metric. It is crucial that the features be rotation-invariant, since
regions with similar patterns of density can be oriented in any arbitrary way.
This pattern-recognition approach can take advantage of data accumulated in large
crystallographic databases to effectively learn the association between electron
density and molecular structure by example.
PMID- 10786296
TI - ESTScan: a program for detecting, evaluating, and reconstructing potential coding
regions in EST sequences.
AB - One of the problems associated with the large-scale analysis of unannotated, low
quality EST sequences is the detection of coding regions and the correction of
frameshift errors that they often contain. We introduce a new type of hidden
Markov model that explicitly deals with the possibility of errors in the sequence
to analyze, and incorporates a method for correcting these errors. This model was
implemented in an efficient and robust program, ESTScan. We show that ESTScan can
detect and extract coding regions from low-quality sequences with high
selectivity and sensitivity, and is able to accurately correct frameshift errors.
In the framework of genome sequencing projects, ESTScan could become a very
useful tool for gene discovery, for quality control, and for the assembly of
contigs representing the coding regions of genes.
PMID- 10786297
TI - Using the Fisher kernel method to detect remote protein homologies.
AB - A new method, called the Fisher kernel method, for detecting remote protein
homologies is introduced and shown to perform well in classifying protein domains
by SCOP superfamily. The method is a variant of support vector machines using a
new kernel function. The kernel function is derived from a hidden Markov model.
The general approach of combining generative models like HMMs with discriminative
methods such as support vector machines may have applications in other areas of
biosequence analysis as well.
PMID- 10786298
TI - An algorithm combining discrete and continuous methods for optical mapping.
AB - Optical mapping is a novel technique for generating the restriction map of a DNA
molecule by observing many single, partially digested, copies of it, using
fluorescence microscopy. The real-life problem is complicated by numerous
factors: false positive and false negative cut observations, inaccurate location
measurements, unknown orientations and faulty molecules. We present an algorithm
for solving the real-life problem. The algorithm combines continuous optimization
and combinatorial algorithms, applied to a non-uniform discretization of the
data. We present encouraging results on real experimental data.
PMID- 10786299
TI - Multiple structural alignment and core detection by geometric hashing.
AB - A Multiple Structural Alignment algorithm is presented. The algorithm accepts an
ensemble of protein structures and finds the largest substructure (core) of C
alpha atoms whose geometric configuration appear in all the molecules of the
ensemble (core). Both the detection of this core and the resulting structural
alignment are done simultaneously. Other large enough multistructural
superimpositions are detected as well. Our method is based on the Geometric
Hashing paradigm and a superimposition clustering technique which represents
superimpositions by sets of matching atoms. The algorithm proved to be efficient
on real data in a series of experiments. The same method can be applied to any
ensemble of molecules (not necessarily proteins) since our basic technique is
sequence order independent.
PMID- 10786300
TI - Metrics and similarity measures for hidden Markov models.
AB - Hidden Markov models were introduced in the beginning of the 1970's as a tool in
speech recognition. During the last decade they have been found useful in
addressing problems in computational biology such as characterising sequence
families, gene finding, structure prediction and phylogenetic analysis. In this
paper we propose several measures between hidden Markov models. We give an
efficient algorithm that computes the measures for left-right models, e.g.
profile hidden Markov models, and briefly discuss how to extend the algorithm to
other types of models. We present an experiment using the measures to compare
hidden Markov models for three classes of signal peptides.
PMID- 10786301
TI - Quantitative, scalable discrete-event simulation of metabolic pathways.
AB - DMSS (Discrete Metabolic Simulation System) is a framework for modelling and
simulating metabolic pathways. Quantitative simulation of metabolic pathways is
achieved using discrete-event techniques. The approach differs from most
quantitative simulators of metabolism which employ either time-differentiated
functions or mathematical modelling techniques. Instead, models are constructed
from biochemical data and biological knowledge, with accessibility and relevance
to biologists serving as key features of the system.
PMID- 10786302
TI - Spatio-temporal registration of the expression patterns of Drosophila
segmentation genes.
AB - The application of image registration techniques resulted in the construction of
an integrated atlas of Drosophila segmentation gene expression in both space and
time. The registration method was based on a quadratic spline approximation with
flexible knots. A classifier for automatic attribution of an embryo to one of the
temporal classes according to its gene expression pattern was developed.)
PMID- 10786303
TI - A dataset generator for whole genome shotgun sequencing.
AB - Simulated data sets have been found to be useful in developing software systems
because (1) they allow one to study the effect of a particular phenomenon in
isolation, and (2) one has complete information about the true solution against
which to measure the results of the software. In developing a software suite for
assembling a whole human genome shotgun data set, we have developed a simulator,
celsim, that permits one to describe and stochastically generate a target DNA
sequence with a variety of repeat structures, to further generate polymorphic
variants if desired, and to generate a shotgun data set that might be sampled
from the target sequence(s). We have found the tool invaluable and quite
powerful, yet the design is extremely simple, employing a special type of
stochastic grammar.
PMID- 10786304
TI - Rapid assessment of extremal statistics for gapped local alignment.
AB - The statistical significance of gapped local alignments is characterized by
analyzing the extremal statistics of the scores obtained from the alignment of
random amino acid sequences. By identifying a complete set of linked clusters,
"islands," we devise a method which accurately predicts the extremal score
statistics by using only one to a few pairwise alignments. The success of our
method relies crucially on the link between the statistics of island scores and
extremal score statistics. This link is motivated by heuristic arguments, and
firmly established by extensive numerical simulations for a variety of scoring
parameter settings and sequence lengths. Our approach is several orders of
magnitude faster than the widely used shuffling method, since island counting is
trivially incorporated into the basic Smith-Waterman alignment algorithm with
minimal computational cost, and all islands are counted in a single alignment.
The availability of a rapid and accurate significance estimation method gives one
the flexibility to fine tune scoring parameters to detect weakly homologous
sequences and obtain optimal alignment fidelity.
PMID- 10786305
TI - Building dictionaries of 1D and 3D motifs by mining the Unaligned 1D sequences of
17 archaeal and bacterial genomes.
AB - We have used the Teiresias algorithm to carry out unsupervised pattern discovery
in a database containing the unaligned ORFs from the 17 publicly available
complete archaeal and bacterial genomes and build a 1D dictionary of motifs.
These motifs which we refer to as seqlets account for and cover 97.88% of this
genomic input at the level of amino acid positions. Each of the seqlets in this
1D dictionary was located among the sequences in Release 38.0 of the Protein Data
Bank and the structural fragments corresponding to each seqlet's instances were
identified and aligned in three dimensions: those of the seqlets that resulted in
RMSD errors below a pre-selected threshold of 2.5 Angstroms were entered in a 3D
dictionary of structurally conserved seqlets. These two dictionaries can be
thought of as cross-indices that facilitate the tackling of tasks such as
automated functional annotation of genomic sequences, local homology
identification, local structure characterization, comparative genomics, etc.
PMID- 10786306
TI - A linear time algorithm for finding all maximal scoring subsequences.
AB - Given a sequence of real numbers ("scores"), we present a practical linear time
algorithm to find those nonoverlapping, contiguous subsequences having greatest
total scores. This improves on the best previously known algorithm, which
requires quadratic time in the worst case. The problem arises in biological
sequence analysis, where the high-scoring subsequences correspond to regions of
unusual composition in a nucleic acid or protein sequence. For instance,
Altschul, Karlin, and others have used this approach to identify transmembrane
regions, DNA binding domains, and regions of high charge in proteins.
PMID- 10786307
TI - Database screening for HIV protease ligands: the influence of binding-site
conformation and representation on ligand selectivity.
AB - Screening for potential ligands and docking them into the binding sites of
proteins is one of the main tasks in computer-aided drug design. Despite the
progress in computational power, it remains infeasible to model all the factors
involved in molecular recognition, especially when screening databases of more
than 100,000 compounds. While ligand flexibility is considered in most
approaches, the model of the binding site is rather simplistic, with neither
solvation nor induced complementary usually taken into consideration. We present
results for screening different databases for HIV-1 protease ligands with our
tool Slide, and investigate the extent to which binding-site conformation,
solvation, and template representation generate bias. The results suggest a
strategy for selecting the optimal binding-site conformation, for cases in which
more than one independent structure is available, and selecting a representation
of that binding site that yields reproducible results and the identification of
known ligands.
PMID- 10786308
TI - A motion planning approach to flexible ligand binding.
AB - Most computational models of protein-ligand interactions consider only the
energetics of the final bound state of the complex and do not examine the
dynamics of the ligand as it enters the binding site. We have developed a novel
technique for studying the dynamics of protein-ligand interactions based on
motion planning algorithms from the field of robotics. Our algorithm uses
electrostatic and van der Waals potentials to compute the most energetically
favorable path between any given initial and goal ligand configurations. We use
probabilistic motion planning to sample the distribution of possible paths to a
given goal configuration and compute an energy-based "difficulty weight" for each
path. By statistically averaging this weight over several randomly generated
starting configurations, we compute the relative difficulty of entering and
leaving a given binding configuration. This approach yields details of the energy
contours around the binding site and can be used to characterize and predict good
binding sites. Results from tests with three protein-ligand complexes indicate
that our algorithm is able to detect energy barriers around the true binding site
that distinguish this site from other predicted low-energy binding sites.
PMID- 10786309
TI - An exact method for finding short motifs in sequences, with application to the
ribosome binding site problem.
AB - This is an investigation of methods for finding short motifs that only occur in a
fraction of the input sequences. Unlike local search techniques that may not
reach a global optimum, the method proposed here is guaranteed to produce the
motifs with greatest z-scores. This method is illustrated for the Ribosome
Binding Site Problem, which is to identify the short mRNA 5' untranslated
sequence that is recognized by the ribosome during initiation of protein
synthesis. Experiments were performed to solve this problem for each of fourteen
sequenced prokaryotes, by applying the method to the full complement of genes
from each. One of the interesting results of this experimentation is evidence
that the recognized sequence of the thermophilic archaea A. fulgidus, M.
jannaschii, M. thermoautotrophicum, and P. horikoshii may be somewhat different
than the well known Shine-Dalgarno sequence.
PMID- 10786310
TI - Seamless integration of biological applications within a database framework.
AB - There are more than two hundred biological data repositories available for public
access, and a vast number of applications to process and interpret biological
data. A major challenge for bioinformaticians is to extract and process data from
multiple data sources using a variety of query interfaces and analytical tools.
In this paper, we describe tools that respond to this challenge by providing
support for cross-database queries and for integrating analytical tools in a
query processing environment. In particular, we describe two alternative methods
for integrating biological data processing within traditional database queries:
(a) "light-weight" application integration based on Application Specific Data
Types (ASDTs) and (b) "heavy-duty" integration of analytical tools based on
mediators and wrappers. These methods are supported by the Object-Protocol Model
(OPM) suite of tools for managing biological databases.
PMID- 10786311
TI - Pharmaceutical target discovery using Guilt-by-Association: schizophrenia and
Parkinson's disease genes.
AB - We wish to identify genes associated with disease. To do so, we look for novel
genes whose expression patterns mimic those of known disease-associated genes, a
method we call Guilt-by-Association (GBA). GBA uses a combinatoric measure of
association that provides superior results to those from correlation measures
used in previous expression analyses. Using GBA, we have examined the expression
of 40,000 human genes in 522 cDNA libraries, and have identified several hundred
genes associated with known cancer, inflammation, steroid-synthesis, insulin
synthesis, neurotransmitter processing, matrix remodeling and other disease
genes. The majority of the genes thus discovered show no significant sequence
similarity to known genes, and thus could not have been identified by homology
searches. We present here an example of the discovery of five genes associated
with schizophrenia and Parkinson's disease. Of the 40,000 most-abundant human
genes, these five genes are the most closely linked to the known disease genes,
and thus are prime targets for pharmaceutical intervention.
PMID- 10786312
TI - Analysis of ribosomal RNA sequences by combinatorial clustering.
AB - We present an analysis of multi-aligned eukaryotic and procaryotic small subunit
rRNA sequences using a novel segmentation and clustering procedure capable of
extracting subsets of sequences that share common sequence features. This
procedure consists of: i) segmentation of aligned sequences using a dynamic
programming procedure, and subsequent identification of likely conserved
segments; ii) for each putative conserved segment, extraction of a locall
homogeneous cluster using a novel polynomial procedure; and iii) intersection of
clusters associated with each conserved segment. Aside from their utilit in
processing large gap-filled multi-alignments, these algorithms can be applied to
a broad spectrum of rRNA analysis functions such as subalignment, phylogenetic
subtree extraction and construction, and organism tree-placement, and can serve
as a framework to organize sequence data in an efficient and easily searchable
manner. The sequence classification we obtained using the method presented here
shows a remarkable consistency with the independently constructed eukaryotic
phylogenetic tree.
PMID- 10786313
TI - Database search based on Bayesian alignment.
AB - The size of protein sequence database is getting larger each day. One common
challenge is to predict protein structures or functions of the sequences in
databases. It is easy when a sequence shares direct similarity to a well
characterized protein. If there is no direct similarity, we have to rely on a
third sequence or a model as intermediate to link two proteins together. We
developed a new model based method, called Bayesian search, as a means to connect
two distantly related proteins. We compared this Bayesian search model with
pairwise and multiple sequence comparison methods on structural databases using
structural similarity as the criteria for relationship. The results show that the
Bayesian search can link more distantly related sequence pairs than other
methods, collectively and consistently over large protein families. If each query
made one error on average against SCOP database PDB40D-B, Bayesian search found
36.5% of related pairs, PSI-Blast found 32.6%, and Smith-Waterman method found
25%. Examples are presented to show that the alignments predicted by the Bayesian
search agree well with structural alignments. Also false positives found by
Bayesian search at low cutoff values are analyzed.
PMID- 10786315
TI - White coat ceremonies for new medical students.
PMID- 10786314
TI - [Efficacy and safety of cefozopran (CZOP) monotherapy and combination therapy
with CZOP and amikacin (AMK) for infections accompanying hematological diseases].
AB - We evaluated efficacy and safety of monotherapy with CZOP (1-2 g x 2/day) and
combination therapy with CZOP (1-2 g x 2/day) and AMK (200 mg x 2/day) for
infections in patients with hematological diseases. Efficacy was evaluated in 71
patients of monotherapy group and 70 patients of combination therapy group.
Underlying diseases were mostly leukemia and lymphoma. Infections included
sepsis, suspected sepsis, pneumonia and so on. Efficacy in CZOP monotherapy was
excellent in 21 patients (31.3%), good in 23 patients (34.3%), fair in 5 patients
(7.5%) and the efficacy rate was 65.7%. On the other hand, in combination
therapy, each was 14 patients (21.2%), 23 patients (34.8%), 12 patients (18.2%)
and the efficacy rate was 56.1%. Side effects such as eruption were noted in 2
patients. Abnormal laboratory findings were noted in 9 patients. All side effects
as well as abnormal laboratory findings were minimal. It was concluded that CZOP
monotherapy was effective in the treatment of various infections accompanying
hematological diseases.
PMID- 10786316
TI - Health professionals have an ethical duty...
PMID- 10786317
TI - Disability, gene therapy and eugenics--a challenge to John Harris.
AB - This article challenges the view of disability presented by Harris in his
article, "Is gene therapy a form of eugenics?" It is argued that his definition
of disability rests on an individual model of disability, where disability is
regarded as a product of biological determinism or "personal tragedy" in the
individual. Within disability theory this view is often called "the medical
model" and it has been criticised for not being able to deal with the term
"disability", but only with impairment. The individual model of disability
presupposes a necessary causal link between a certain condition in the individual
and disablement. The shortcomings of such a view of disability are stated and it
is argued that in order to have an adequate ethical discourse on gene therapy
perspectives from disability research need to be taken into consideration.
PMID- 10786318
TI - Is there a coherent social conception of disability?
AB - Is there such a thing as a social conception of disability? Recently two writers
in this journal have suggested not only that there is a coherent social
conception of disability but that all non-social conceptions, or "medical models"
of disability are fatally flawed. One serious and worrying dimension of their
claims is that once the social dimensions of disability have been resolved no
seriously "disabling" features remain. This paper examines and rejects
conceptions of disability based on social factors but notes that physical and
mental conditions which disadvantage the individual have social dimensions.
PMID- 10786319
TI - Parental consent to cosmetic facial surgery in Down's syndrome.
AB - It is suggested that the practice of attempting to normalise children with Down's
syndrome by subjecting them to major facial plastic surgery has no therapeutic
benefit, and should be seen as multilating surgery comparable to female
circumcision.
PMID- 10786320
TI - The morality of abortion and the deprivation of futures.
AB - In an influential essay entitled Why abortion is wrong, Donald Marquis argues
that killing actual persons is wrong because it unjustly deprives victims of
their future; that the fetus has a future similar in morally relevant respects to
the future lost by competent adult homicide victims, and that, as consequence,
abortion is justifiable only in the same circumstances in which killing competent
adult human beings is justifiable. The metaphysical claim implicit in the first
premise, that actual persons have a future of value, is ambiguous. The Future
Like Ours argument (FLO) would be valid if "future of value" were used
consistently to mean either "potential future of value" or "self-represented
future of value", and FLO would be sound if one or the other interpretation
supported both the moral claim and the metaphysical claim, but if, as I argue,
any interpretation which makes the argument valid renders it unsound, then FLO
must be rejected. Its apparent strength derives from equivocation on the concept
of "a future of value".
PMID- 10786321
TI - Would you like to know what is wrong with you? On telling the truth to patients
with dementia.
AB - OBJECTIVES: To discover what dementia sufferers feel is wrong with them; what
they have been told and by whom, and what they wish to know about their illness.
BACKGROUND: Ethical guidelines regarding telling truth appear to be equivocal.
Declarations of cognitively intact subjects, attitudes of family members and
current psychiatric practice all vary, but no previous research has been
published concerning what patients with dementia would in fact like to know about
their diagnosis and prognosis. DESIGN: Questionnaire study of the patients'
opinions. SETTING: Old Age Psychiatry Service in Worcester. PARTICIPANTS: 30
consecutive patients with dementia. RESULTS: The quality of information received
has been poor and many patients have no opportunity to discuss their illness with
anybody. Despite that almost half of the participants in this study had adequate
insight and a majority declared that they would like to know more about their
predicament. CONCLUSIONS: Although many patients would like to know the truth,
the rights of those who do not want to know should also be respected. Therefore
the diagnosis of dementia should not be routinely disclosed but (just as in other
disorders) health care professionals should seek to understand their patients'
preferences and act appropriately according to their choice.
PMID- 10786322
TI - Decisions to treat or not to treat pneumonia in demented psychogeriatric nursing
home patients: development of a guideline.
AB - Non-treatment decisions concerning demented patients are complex: in addition to
issues concerning the health of patients, ethical and legal issues are involved.
This paper describes a method for the development of a guideline that clarifies
the steps to be taken in the decision making process whether to forgo curative
treatment of pneumonia in psychogeriatric nursing home patients. The method of
development consisted of seven steps. Step 1 was a literature study from which
ethical, juridical and medical factors concerning the patient's health and
prognosis were identified. In step 2, a questionnaire was sent to 26 nursing home
physicians to determine the relative importance of these factors in clinical
practice. In a meeting of nine experienced physicians (step 3), the factors
identified in step 2 were confirmed by most of these professionals. To prevent
the final guideline being too directive, a concept guideline that included
ethical and legal aspects was designed in the form of a "checklist of
considerations" (step 4). Experts in the fields of nursing home medicine, ethics
and law reviewed and commented on the concept guideline (step 5). The accordingly
adapted "checklist of considerations" was tested in a pilot study (step 6), after
which all experts endorsed the checklist (step 7). The resulting "checklist of
considerations" structures the decision making process according to three primary
domains: medical aspects, patient's autonomy, and patient's best interest (see
annex at end of paper).
PMID- 10786323
TI - Death--whose decision? Euthanasia and the terminally ill.
AB - In Australia and Oregon, USA, legislation to permit statutory sanctioned
physician-assisted dying was enacted. However, opponents, many of whom held
strong religious views, were successful with repeal in Australia. Similar
opposition in Oregon was formidable, but ultimately lost in a 60-40% vote
reaffirming physician-assisted dying. This paper examines the human dilemma which
arises when technological advances in end-of-life medicine conflict with
traditional and religious sanctity-of-life values. Society places high value on
personal autonomy, particularly in the United States. We compare the potential
for inherent contradictions and arbitrary decisions where patient autonomy is
either permitted or forbidden. The broader implications for human experience
resulting from new legislation in both Australia and Oregon are discussed. We
conclude that allowing autonomy for the terminally ill, within circumscribed
options, results in fewer ethical contradictions and greater preservation of
dignity.
PMID- 10786324
TI - Paying research subjects: participants' perspectives.
AB - OBJECTIVE: To explore the opinions of unpaid healthy volunteers on the payment of
research subjects. DESIGN: Prospective cohort. SETTING: Southern Alberta, Canada.
PARTICIPANTS: Medically eligible persons responding to recruiting advertisements
for a randomised vaccine trial were invited to take part in a study of informed
consent at the point at which they formally consented or refused trial
participation. Of 72 invited, 67 (62 trial consenters, 5 trial refusers) returned
questionnaires at baseline and 54 at follow-up. OUTCOME MEASURES: Proportions of
persons who agreed or disagreed with three close-ended statements on the payment
of research subjects; themes and categories identified by content analysis of
responses to an open-ended question. RESULTS: A minority (43.3%) agreed with
paying either patient or healthy volunteer participants. Opinions did not change
over time. Participants' comments addressed: benefits and drawbacks to research
participation; benefits and drawbacks to paying research participants; conditions
under which payment of research subjects would be acceptable, and the nature of
acceptable recognition. Acceptable conditions were to improve problematic
recruitment, to reimburse costs, and to recognise participants, particularly for
their time investment. Both non-monetary and monetary recognition of volunteers
were thought to be appropriate. CONCLUSIONS: Most unpaid volunteers disagreed
with paying research participants. The themes arising from their comments are
similar to those that have been raised by ethicists and suggest that recognising
the time and effort of participants should receive greater emphasis than
presently occurs.
PMID- 10786325
TI - Talking about cases in bioethics: the effect of an intensive course on health
care professionals.
AB - Educational efforts in bioethics are prevalent, but little is known about their
efficacy. Although previous work indicates that courses in bioethics have a
demonstrable effect on medical students, it has not examined their effect on
health care professionals. In this report, we describe a study designed to
investigate the effect of bioethics education on health care professionals. At
the Intensive Bioethics Course, a six-day course held annually at Georgetown
University, we administered a questionnaire requiring open-ended responses to
vignettes both before and after the course. Following the course, respondents
defended their responses more carefully and articulated their thoughts more
clearly. In addition, after the course respondents seemed to have a more subtle
understanding of the relevant issues in the cases and applied theory to these
cases more frequently. These findings help to formulate an understanding of the
effect of bioethics education on health care professionals.
PMID- 10786327
TI - Autonomy and identity.
PMID- 10786326
TI - The man who claimed to be a paedophile.
AB - A psychiatrist recounts a case of a man presenting with severe depression who
claimed to have abused children and his pet dog. Clinical management of the case
hinged on whether this claim was true, a lie or delusional. The uncertainty over
this raised complex ethical dilemmas regarding confidentiality and protection of
the public (and animals).
PMID- 10786328
TI - Japanese physicians and the care of adult patients in persistent vegetative
state.
PMID- 10786329
TI - Ethical ethics committees?
PMID- 10786330
TI - [Prognostic significance of advanced atrioventricular block in patients with
acute myocardial infarction].
AB - BACKGROUND: Advanced atrioventricular block (AB) during acute myocardial
infarction (AMI), characterizes a high-risk subgroup of patients. Our aim was to
determine the prognostic significance of AB and its possible peculiarities in
relation to infarction localization and/or the thrombolytic therapy. PATIENTS AND
METHODS: The prospective study involved 1,239 patients with AMI. We studied
clinical characteristics, as well as indexes of infarct size, short and long-term
complications. RESULTS: AB was present in 85 (6.8%) patients and was more often
associated with: previous treatment with diuretics, diabetes, inferior
localisation, higher number of ECG leads with elevated ST segment, and higher
peak of CK. The AB was associated with a higher mortality: in-hospital (27% vs
10.6%; p < 0.01)) and after one-year (31.7% vs 19.4%; p < 0.05). Patients with AB
had a different in-hospital mortality depending on anterior or inferior infarct
localization (66% vs 18.5%; p < 0.001, respectively). In patients receiving
thrombolytic treatment (n = 681), the duration of AB was shorter and in-hospital
mortality was lower (13.7% vs 47%, p < 0.11) than that occurred in patients
without this treatment (n = 558). AB had independent value for predicting in
hospital mortality (OR: 3.56; 95% CI: 1.84-6.90) and one-year mortality (OR:
2.77; 95% CI: 1.52-5.04). CONCLUSIONS: AB is associated with larger infarcts and
higher incidence of complications. The prognosis is especially poor when it is
presented associated with anterior infarction and/or in patients without
thrombolytic treatment. AB is a variable with independent prognostic value on the
mortality.
PMID- 10786331
TI - [High prevalence of vitamin D deficiency in postmenopausal women at a
rheumatology office in Madrid. Evaluation of 2 vitamin D prescription regimens].
AB - BACKGROUND: Vitamin D deficiency has been frequently observed in the elderly
population in Europe. However few information is available about the vitamin D
status in postmenopausal women in the Mediterranean countries. The aim of this
study was to evaluate the vitamin D status assessed by serum 25(OH)D3 (calcidiol)
in postmenopausal women who attended a Rheumatology practice in Madrid area, and
to evaluate calcidiol serum levels through one year after two forms of vitamin D
administration. PATIENTS AND METHODS: Calcidiol serum levels were measured in 171
postmenopausal women (111 with osteoporosis and 60 without osteoporosis). 82
women with calcidiol serum levels < 10 ng/ml were distributed in two groups:
Group I received 800 U/day of vitamin D3 associated with calcium (1 g/day) and
group II, one dose of 80,000 U vitamin D orally as calcidiol and latter a daily
dose of 800 U vitamin D3 plus 1 g calcium. Calcidiol serum levels were measured
by RIA in both groups at basal condition and after three, six and twelve months
under treatment. RESULTS: Three cut-offs were considered: 10, 15 and 20 ng/ml of
calcidiol. Percentages of postmenopausal women with vitamin D deficiency for such
cut-offs were: 35.3%, 64.1% and 87.1%, respectively. After three months of
treatment, women from group II showed calcidiol serum levels higher than group I.
At six and twelve months calcidiol serum levels were similar in both groups.
CONCLUSIONS: A high prevalence of vitamin D deficiency was observed in a group of
postmenopausal women who attended a rheumatology practice in Madrid area. Both
forms of vitamin D administration seem not sufficient to maintain the adequate
calcidiol serum levels in postmenopausal deficient women. A dose of 80,000 U of
calcidiol twice a year should be considered.
PMID- 10786332
TI - [Variability of polyphenol content in different types of wine and its potential
application in the understanding of its biologic effects].
AB - BACKGROUND: Wine polyphenols have antioxidant properties. Different polyphenols
have various biological activities on atherogenesis and carcinogenesis. MATERIAL
AND METHODS: The composition on 5 polyphenols of 16 wines of Castilla (Spain) is
determined by HPLC. RESULTS: Polyphenols concentrations varied largely among the
different wines. Most red wines had higher amounts of polyphenols than white
wines. CONCLUSIONS: The diverse composition on polyphenols of each wine allows to
suggest different biological effects.
PMID- 10786334
TI - [Videothoracoscopic surgery in the year 2000].
PMID- 10786333
TI - [Localization of lung nodules with CT-guided hookwire before videothoracoscopic
surgery].
AB - PURPOSE: To localize peripheral lung nodules under CT guidance using hookwires,
prior to video-assisted thoracic surgery (VATS). PATIENTS AND METHODS: Twenty-two
pulmonary nodules were localized with a hookwire under CT guidance. The visceral
pleura was stained with methylene blue. VATS was performed thereafter. RESULTS:
All nodules were successfully localized and resected without significant
complications. CONCLUSIONS: In select cases, localization of pulmonary nodules
with hook wire and methylene blue allows the thoracoscopic resection of
unaccessible lesions.
PMID- 10786335
TI - [Myths and reality about scientific publication].
PMID- 10786336
TI - [Genetically engineered animals as organ donors in xenotransplantation].
PMID- 10786337
TI - [Severe liver failure and lesions located in liver space in a 33-year-old
patient].
PMID- 10786338
TI - [Safety of antidepressive agents in pregnancy].
PMID- 10786339
TI - [Neurologic manifestations of Schoenlein-Henoch purpura].
PMID- 10786340
TI - [Adequacy of pharmaceutic dosage forms of antiretroviral therapy].
PMID- 10786341
TI - [Lung infection caused by Aspergillus fumigatus and Nocardia asteroides as
complication of glucocorticoid treatment].
PMID- 10786342
TI - [Indiscretion and right to privacy in the health system].
PMID- 10786343
TI - [Withdrawal syndrome and cytalopram].
PMID- 10786344
TI - [Cytokeratins (UBC and CYFRA 21-1) and nuclear matrix proteins (NMP22) as urine
tumor markers in the diagnosis of bladder cancer].
AB - BACKGROUND: The development of urinary tumor markers such as UBC, CYFRA 21-1 and
NMP22 appeared to be non invasive alternative methods for the detection of
bladder cancer. We compared the individual and combined sensitivity of the
urinary tumor markers in the detection of bladder cancer, contrasting them with
the conventional diagnostic procedures. PATIENTS AND METHODS: 237 voided urines
from subjects under risk for bladder cancer were collected immediately before the
endoscopic examinations: 44 patients under suspicion of a primary bladder tumor
and 193 patients under follow-up of a previous bladder cancer were included. UBC
and NMP22 were measured by enzyme-immunoabsorbent-assays and CYFRA 21-1 by an
electro-chemiluminescense-immunoassay. RESULTS: Taking the cutoffs of 9.7
micrograms/l for UBC, 5.4 ng/ml for CYFRA 21-1 and 10.0 U/ml for NMP22
sensitivities were 70%, 69% and 67% for UBC, CYFRA 21-1 and NMP22 at
specificities of 95%, 94% y 80%, respectively. All tumor markers showed higher
sensitivities than urinary cytology (7%), microhematuria (62%) and gross
hematuria (10%) at specificities of 99%, 78% and 99%, respectively. The
combinations of NMP22 plus CYFRA 21-1 reached the highest sensitivity (79%),
slightly lower than simultaneously measuring the three tumor markers (80%).
CONCLUSIONS: The sensitivities of the urinary markers UBC, CYFRA 21-1 and NMP22
appeared to be high enough so as to substitute urinary cytology. The diagnostic
similarity between cytokeratins individually and in each type of patients might
not recommend their simultaneous determination. The combined measurement of NMP22
and one cytokeratin marker (CYFRA 21-1 or UBC) appeared to be the most
recommended.
PMID- 10786345
TI - [Prevalence and clinical significance of antiphospholipid antibodies in chronic
hepatitis C].
AB - BACKGROUND: To know the prevalence of antiphospholipid antibodies in chronic
hepatitis C and their relationship with disease progression. METHODS: One hundred
and twenty-eight patients with chronic hepatitis C and 93 healthy controls were
enrolled up. We determined platelets, ALT, gamma GT, RNAHCV in serum and liver
and non-organ specific antibodies, grade and stage in liver biopsy, risk factors,
duration of disease and alcohol intake were also included. Portal hypertension
and liver function parameters were studied. Antiphospholipid antibodies (APA):
lupus anticoagulant (LA) and anticardiolipin antibodies (ACA) (IgG and IgM) were
measured by EIA. Anti-beta 2 glycoprotein I antibodies were also detected by EIA
in ACA positive patients. RESULTS: Thirty one out of 128 (25%; 95% CI: 17.8%
33.4%) showed positive antiphospholipid antibodies. Positive ACA-IgG was higher
in patients than controls (22% vs 3.2%; p < 0.05), whereas, ACA-IgM was similar
(5% vs 3.2%; p = NS), and LA was absent in both groups. ALT levels, viraemia,
viral load in liver, platelets, or ANA titre were similar in patients with and
without positive ACA-IgG. Risk factors, duration of disease or alcohol intake
were not related yet. Patients with staging F1 showed positive ACA-IgG 4 of 44
(9%; 95% CI: 2.5%-21.7%), in staging F2 7 of 39 (18%; 95% CI: 7.5%-33.5%) and in
staging F4 17 of 45 (38%; 95% CI: 23.8%-53.5%; p < 0.005). ACA-IgG was
significantly related to portal hypertension, Child-Pugh stage and presence of
cirrhosis complications. Anti-beta 2 glycoprotein I antibodies were detected in
ten (43.5%; CI 95%: 23.2%-65.5%) out of 23 ACA positive patients. CONCLUSIONS:
ACA-IgG seems to be associated with chronic hepatitis C, and could play a
potential role in fibrosis progression and liver disease in these patients.
PMID- 10786346
TI - [Effect of topical and oral diclofenac on superficial thrombophlebitis caused by
intravenous infusion].
AB - BACKGROUND: Until present time, suggested treatments for superficial
thrombophlebitis induced by intravenous infusion (TFSI), are of uncertain
effectiveness and most of them or empirical and not fully researched. The aim of
this report is to study the effectiveness and safety of the topical and oral
administration of diclofenac in the treatment of TFSI. PATIENTS AND METHODS: In
this prospective study 120 patients both female and male were included. All of
them developed TFSI during hospitalization and at the same time they were
assigned at random to one of the following groups: G-control (n = 40), without
treatment; G-topical (n = 40), diclofenac emulsion gel used in a topical way on
the concerned area every 8 hours during 48 hours; G-oral (n = 40), diclofenac 75
mg p.o. every 12 hours during 48 hours. The measurements were done at the moment
of diagnosis of TFSI (T0) and 48 hours later (T2). Registries of intensity of
TFSI were done by quantifying flushing, tumor, heatness and pain. These data were
compared considering the averages of differences registered in T2 with respect to
T0. A decrease of intensity of TFSI > or = 30% was considered a positive answer
to this treatment. The quantitative variables were studied with ANOVA, Kruskal
Wallis test or general linear model and the qualitative with the chi 2 test with
Yates correction. The level of significance used was alpha = 0.05. RESULTS: The
averages of differences in the intensity of TFSI that were registered in the
groups G-control, G-topical and G-oral in T2 compared to T0 are: -0.12 (4.89),
5.70 (3.13), -4.82 (3.14) (p = 0.000). The favorable answers in G-control, G
topical and G-oral were: 20, 60 and 60%, respectively (p = 0.0001). The adverse
reactions in G-topical and G-oral were: headache 9-5 (p = 0.2), epigastric pain 4
17 (p = 0.0009), nausea 6-16 (p = 0.01) and local pruritus 5-2 (p = 0.2). The
treatment did not report serious adverse reactions in either of the groups.
CONCLUSION: The topical treatment of diclofenac can be recommended as an
alternative simple, effective and safe therapy for patients who develop TFSI.
PMID- 10786347
TI - [Selection of pharmacologic treatment of arterial hypertension in primary care.
Task force on Pharmacologic Approach of Hypertension in Primary Care (AFHAP)].
AB - BACKGROUND: To assess whether patients' clinical characteristics, and more
specifically contraindications to diuretics or beta-blockers have an influence on
the prescription patterns of antihypertensive drugs. PATIENTS AND METHODS: Cross
sectional descriptive study of consecutive hypertensive patients attending 28
Primary Health Care Centres in Barcelona between November 1997 and February 1998.
Information on patients' clinical characteristics and prescribed antihypertensive
and other drugs was recorded. Hyperuricemia, a previous adverse drug reaction and
potential drug interactions were considered as contraindications to diuretics.
Asthma, chronic obstructive airway disease, peripheral arteriopathy, bradycardia,
atrio-ventricular blockade, type 1 diabetes, a previous adverse drug reaction,
and potential drug interactions were considered as contraindications to beta
blockers. RESULTS: Eighty-three general practitioners and 29 nurses collected
data on 1,813 patients (66% were women and mean age was 68 years). Dyslipemia was
present in 746 patients (41.1%), diabetes in 385 (21.2%), hyperuricemia in 251
(13.8%), coronary heart disease in 218 (12%), and heart failure in 128 (7.1%).
Diuretics were contraindicated in 350 patients (19.3%) and beta-blockers in 537
(29.6%). Eight-hundred seventy-nine patients (48.5%) were prescribed an
angiotensin-converting-enzyme (ACE) inhibitor, 803 (44.3%) a diuretic, 521
(28.7%) a calcium-channel blocker, and 246 (13.6%) a beta-blocker. The
prescription pattern was similar in both patients with existing contraindications
to diuretics or beta-blockers, or without them, and in those with and without
diabetes, heart failure or coronary heart disease and in those whose clinical
characteristics would make the prescription of a diuretic, a beta-blocker or an
ACE-inhibitor a first choice option. Prescription of a diuretic was associated to
age and to existing contraindications to a beta-blocker, whereas the prescription
of a beta-blocker was associated with a history of coronary heart disease.
CONCLUSIONS: The present study suggests that contraindications to diuretics or
beta-blockers are not considered when prescribing antihypertensive drugs. The
results of clinical trials are not applied to clinical practice, and this results
in a high proportion of patients not being offered the benefit of cardiovascular
risk prevention.
PMID- 10786348
TI - [Tumor markers of bladder cancer].
PMID- 10786349
TI - [Arterial hypertension: the better we know it, the worse we treat it].
PMID- 10786350
TI - [Rationale for the need of social planning in the training of new physicians].
PMID- 10786351
TI - [Infective complications in recipients of swine xenotransplant].
PMID- 10786352
TI - [Malignant hypertension, adrenal gland lesions with positive iodomethyl-benzyl
guanidine test in a 30-year-old patient with renal agenesis and kidney transplant
which functioned for 6 years, and subsequent hemodialysis].
PMID- 10786353
TI - [Lansoprazole-induced gynecomastia].
PMID- 10786354
TI - [Gestational diabetes mellitus: systematic or selective screening? The debate
continues].
PMID- 10786355
TI - [ANCA-positive vasculitis associated with propylthiouracil].
PMID- 10786356
TI - [Methadone withdrawal syndrome induced by nevirapine].
PMID- 10786357
TI - [Factors associated with the accumulation of abdominal fat estimated with
anthropometric indexes].
AB - BACKGROUND: To evaluate lifestyle and dietary intake factors influencing the
accumulation of abdominal fat in a Mediterranean population. SUBJECTS AND METHOD:
A cross-sectional study was carried-out in Spain (Asturias, Granada, Murcia,
Navarra and Guipuzkoa) among 23,228 women and 14,332 men aged 29-69 years,
participants of a large European prospective cohort (EPIC). Information on usual
food intake and other non-dietary factors were collected by interviews. Height,
weight, waist circumference and hip circumference were taken by previously
trained interviewers. RESULTS: In a multiple-linear regression analysis sports
activities and educational level were negatively associated with abdominal
obesity, while body mass index, age, tobacco and alcohol consumption, saturated
fat intake and increased prevalence of hypertension, diabetes and myocardial
infarction were positively associated. All dietary and non-dietary variables
accounted for 22 and 27% of variance in the waist/hip ratio and 74 and 66% of
variance in the waist circumference, in women and men respectively. CONCLUSIONS:
Body mass index and age are the most important factors influencing the
accumulation of abdominal fat. Dietary factors and other lifestyle factors seem
to play a minor role in increasing abdominal obesity.
PMID- 10786358
TI - [Laboratory diagnosis and serologic course in patients with tularemia].
AB - BACKGROUND: Tularemia was practically unknown in Spain until the end of 1997,
when an epidemic outbreak was declared. This paper presents the data on
microbiological diagnosis of 55 patients who suffered from tularemia. PATIENTS
AND METHODS: Thirty-two samples from 19 patients and 151 serum samples from 55
patients were obtained for culture. Serologic diagnosis was performed by tube
sero-agglutination and microagglutination. Three types of tests were performed on
all sera: Wright sero-agglutination (WSA), Coombs test against Brucella spp. and
sero-agglutination against Yersinia enterocolitica O:3, Yersinia enterocolitica
O:3, and Proteus OX 19. RESULTS: F. tularensis was found in two samples (6.25%)
of the 32 received. Titers > or = 1/160 were obtained in 78.2% and 74.5% of the
initial sera by tube sero-agglutination and microagglutination, respectively.
Correlation between the two tests was 0.80 (p < 0.001). Prozone phenomenon was
observed in 59.9% of the sera, while crossed reactivity to Brucella spp. and
Proteus spp. was found in 9.3% and 22.8%, respectively. No crossed reactivity was
observed with Yersinia spp. CONCLUSIONS: Culture of F. tularensis has low
sensitivity. The correlation obtained between tube sero-agglutination and
microagglutination is good. Both techniques are useful in routine diagnosis of
tularemia, although microagglutination has some advantages over tube
agglutination.
PMID- 10786359
TI - [Hodgkin's disease. Etiopathogenic role of Epstein-Barr virus in Tarragona].
AB - BACKGROUND: The aim of this study is to assess the proportion of Hodgkin disease
(HD) expressing Epstein-Barr virus (EBV) in our area (Tarragona-Spain). PATIENTS
AND METHODS: A retrospective study was performed on paraffin embedded HD tissues
from 49 patients to examine the presence of latent membrane protein (LMP-1) by
immunohistochemistry and for EBER-1 in situ hybridization. RESULTS: Overall, EBV
(EBER-1 and/or LMP positive) was expressed in 20 cases (40.8%). This percentage
was higher, but not significant, in mixed cellularity, and significant higher in
patients over 55 years old. No differences between sexes were observed.
CONCLUSIONS: EBV is associated with 40.8% of HD in area of Tarragona.
PMID- 10786360
TI - [Folic acid ingestion and associated factors in adult women 15-44 years of age in
the Valencian Community].
AB - BACKGROUND: A low folic acid (FA) intake may increase the risk of neural tube
defects (NTD). We estimated the proportion of women with a FA intake < 400
micrograms/day, at the Valencian Region, exploring those factors associated with
a FA intake < 400 micrograms/day. SUBJECTS AND METHOD: Daily FA intake was
estimated for 538 women aged 15 to 44 years participants in the Nutrition Survey
of Valencian Region in 1994, and factors associated with an intake lower than 400
micrograms/day were analyzed. RESULTS: The average FA intake was 392
micrograms/day. A 57.6% of women presented a low FA intake. A higher prevalence
of low FA intake was found among youngest women with low sports practice, low
body mass index and early menarche. CONCLUSIONS: A high proportion of women with
a FA intake considered at risk for NTD was observed, particularly among the
youngest with low sports practice.
PMID- 10786361
TI - [Abdominal obesity: is the waist/hip ratio useful?].
PMID- 10786362
TI - [What can we expect from continuing medical education? Myths and reality].
PMID- 10786363
TI - [Angiostatin and its antitumor activity].
PMID- 10786364
TI - [Incidence of tuberculous infection in a Spanish prison].
PMID- 10786365
TI - [Gordon's syndrome, type II pseudohypoaldosteronism, Spitzer-Weinstein syndrome,
and chloride shunt syndrome, or the 4-name disease].
PMID- 10786366
TI - [Treatment of amyloidosis secondary to rheumatoid arthritis with methotrexate].
PMID- 10786367
TI - [Telomerase and cancer].
PMID- 10786368
TI - [Integrins and their role in malignant neoplasm progression].
PMID- 10786369
TI - [Antigen CD44: does the presence of its isoforms have significance for diagnosis
for diagnosis of colorectal cancer?].
PMID- 10786370
TI - [Actin isoforms--functional differentiation, changes in cell pathology].
PMID- 10786371
TI - [Transport of proteins and RNA between the nucleus and the cytoplasm].
PMID- 10786372
TI - [The significance of thrombomodulin in regulation of coagulation and
fibrinolysis].
PMID- 10786373
TI - [Eukaryotic plasmids].
PMID- 10786374
TI - [Mechanism of arsenic compound resistance in prokaryotes and eukaryotes].
PMID- 10786375
TI - [Mutagenicity an carcinogenicity of aflatoxin AFB1].
PMID- 10786376
TI - [Combinatorial biosynthesis of novel macrolides and other complex polyketides].
PMID- 10786377
TI - [Induced chlorophyll fluorescence as a source of information about photosynthesis
processes in plants and their environmental conditions].
PMID- 10786378
TI - ATSDR evaluation of health effects of chemicals. VI. Di(2-ethylhexyl)phthalate.
Agency for Toxic Substances and Disease Registry.
AB - Di(2-ethylhexyl)phthalate (also known as DEHP, bis(2-ethylhexyl)phthalate, or
BEHP; CAS Registry Number 117-81-7) is a widely-used plasticizer. It is found in
numerous plastic articles, such as paints, inks, floor tiles, upholstery, shower
curtains, footwear, plastic bags, food-packaging materials, toys, and medical
tubing. Not surprisingly, DEHP appears at many waste sites. As part of its
mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares
toxicological profiles on hazardous chemicals that are of greatest public health
concern at Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) National Priority List (NPL) sites. These profiles comprehensively
summarize toxicological and environmental information. This article constitutes
the release of the bulk of ATSDR's profile for DEHP (ATSDR, 1993) into the
mainstream scientific literature. An extensive listing of human and animal health
effects, organized by route, duration, and endpoint, is presented. Toxicological
information on toxicokinetics, biomarkers, interactions, sensitive
subpopulations, reducing toxicity after exposure, and relevance to public health
is also included. Environmental information encompasses physical properties,
production and use, environmental fate, levels seen in the environment,
analytical methods, and a listing of regulations. ATSDR, at the behest of
Congress and therefore the citizenry, prepares these profiles to inform the
public about site contaminants.
PMID- 10786379
TI - Congenital anomaly: middle ear malformation.
PMID- 10786380
TI - Anatomy of the uncinate process.
PMID- 10786381
TI - Vocal fold hemangioma.
PMID- 10786382
TI - Osteogenesis imperfecta.
PMID- 10786383
TI - A patient with Meniere's syndrome: ear-under nystagmus is opposite of clinical
findings; caloric result shows directional preponderance.
PMID- 10786384
TI - Intralesional cidofovir for recurrent laryngeal papillomas: preliminary report.
AB - This is a preliminary report of an ongoing study to test the efficacy of
intralesional injections of the antiviral drug cidofovir in adults with recurrent
laryngeal papillomas in whom multiple other treatments have previously failed.
This study has been designed to include 10 to 20 patients, a number sufficient to
either prove or disprove the safety and efficacy of this agent. This report
conveys information on the first three patients enrolled in the trial. Each
patient received an overall dose of 5 to 10 ml of cidofovir, at a concentration
of 4.17 mg/ml, intralesionally at 2- to 4-week intervals. The approximate volume
injected into each wart was 0.2 to 0.5 ml. Biopsies of the lesion sites were
obtained at the initiation and completion of therapy. No other treatment was
given. Resolution of lesions was monitored by videolaryngoscopy and still
photography 1 to 2 weeks after each treatment. In time, the lesions resolved in
all three patients, although all three later experienced a minor recurrence. We
conclude that intralesional cidofovir appears to be a promising new treatment for
controlling--and perhaps at higher dosages curing--refractory laryngeal
papillomas, while causing little or no injury to laryngeal structures.
PMID- 10786385
TI - Professionalism, where are you?
AB - The practice of medicine continues to evolve in ways that are not always
compatible with good patient care, and physicians now control less and less of
their practices. One of the casualties of the new health economics is the concept
of professionalism, which becomes more difficult to adhere to in the face of
restrictions placed by outside forces. Nevertheless, physicians can maintain a
sense of professionalism despite all the difficulties. Indeed, we must do so in
order to remain true to our ideals.
PMID- 10786386
TI - A case of squamous papilloma after uvulopalatopharyngoplasty.
AB - We report the case of an adult who developed an isolated-solitary papilloma on
the margin of the soft palate 1 month after he had undergone a
uvulopalatopharyngoplasty. We describe the clinical and cellular characteristics
of this common lesion.
PMID- 10786387
TI - Loratadine/pseudoephedrine for nasal symptoms in seasonal allergic rhinitis: a
double-blind, placebo-controlled study.
AB - In this double-blind, placebo-controlled, crossover, parallel study, we treated
20 adults who had seasonal allergic rhinitis with once-daily fixed-combination
loratadine/pseudoephedrine sulfate to observe its effect on relieving symptoms,
primarily nasal congestion. Acoustic rhinometry detected a trend toward
improvement in nasal patency, although the difference between pre- and post
treatment measures was not statistically significant. Endoscopic inferior
turbinate photography documented that treatment led to statistically significant
reductions in the amount of nasal edema and nasal secretions. The results of a
quality-of-life questionnaire suggested that treatment alleviated nasal and
ocular symptoms of rhinoconjunctivitis. An analysis of subjective visual analog
scale scores showed a trend toward improvement in most but not all nasal
symptoms. We conclude that once-a-day fixed-combination
loratadine/pseudoephedrine is effective in relieving nasal congestion in patients
with seasonal allergic rhinitis.
PMID- 10786388
TI - eMedicine Otolaryngology: an online textbook for ENT specialists.
AB - A new online publishing effort, eMedicine Otolaryngology-Facial Plastic Surgery
(FPS), is a comprehensive textbook now being developed on the Internet
(www.emedicine.com). This book is one of a series of 15 electronic textbooks
written by a worldwide panel of authors and editors, and it is distributed free
of charge to anyone with a computer and a modem. Advantages of online textbooks
such as eMedicine Otolaryngology-FPS are that they provide readers with easy
accessibility to reliable, up-to-date information, and they allow authors to
quickly edit and revise editorial content and supplement traditional text with
sound, graphics, and video. An ambitious undertaking, eMedicine Otolaryngology
FPS represents a significant advance in the way medical information is written,
edited, and distributed. Although it is unlikely that electronic textbooks will
replace traditional textbooks any time soon, these types of publishing efforts
will continue to proliferate.
PMID- 10786389
TI - Bilateral laryngoceles in a young trumpet player: case report.
AB - We report the case of a 16-year-old trumpet player who was referred for an
otolaryngologic consultation after his band leader noticed that a neck mass would
protrude while the boy was playing. X-rays revealed the presence of bilateral
laryngoceles, and computed tomography demonstrated bilateral, air-filled
outpouchings of the laryngeal saccules during forced expiration. There was no
evidence of any other intra-laryngeal or cervical pathology. Surgery was deferred
while the laryngoceles remained reducible and asymptomatic, and the boy was
cleared to continue playing.
PMID- 10786390
TI - Rebuilding the inferior turbinate with hydroxyapatite cement.
AB - This article describes a method of reconstructing a totally resected inferior
turbinate with hydroxyapatite cement in patients who experience symptoms often
associated with an overzealous resection of the turbinate (the "empty nose"
syndrome).
PMID- 10786391
TI - Aggressive combination treatment for invasive fungal sinusitis in
immunocompromised patients.
AB - Invasive sinonasal fungal disease is a potentially fatal complication of
chemotherapy-induced immunosuppression and neutropenia. We reviewed the outcomes
of seven cancer patients who had been diagnosed with invasive fungal sinusitis;
six patients had hematologic malignancies and one had breast cancer. At the time
of their sinus diagnosis, all patients had been hospitalized and were receiving
combination chemotherapy for their underlying malignancy. Impairment of their
immune function was characterized by an absolute neutrophil count of less than
1,000/mm3. Aggressive management of their sinonasal fungal disease consisted of
surgical debridement and systemic amphotericin B for all patients, and treatment
with granulocyte colony-stimulating factor for two patients. Invasive Aspergillus
infection was identified in six patients and invasive Candida albicans infection
in one. Although the prognosis for these patients was poor and two patients died
of the fungal infection, the aggressive treatment strategy resulted in long-term
survival for the remaining five patients.
PMID- 10786392
TI - Transient speech compromise following sublabial transsphenoidal surgery: a case
report and findings of a small preliminary study.
AB - Sublabial transsphenoidal surgical removal of pituitary tumors is a common
procedure with minimal complications. Although many investigators have reported
oral sensory compromises following surgery, none has reported any postoperative
compromise in speaking ability. In this article, we describe the case of a 33
year-old woman who developed transient but severe speech symptoms after she
underwent sublabial transsphenoidal surgery. This case prompted us to undertake a
brief retrospective analysis of our experience with this procedure in other
patients, which revealed that speech compromise is far more common than
heretofore realized.
PMID- 10786393
TI - Treatment of otitis media with effusion based on politzerization with an
automated device.
AB - This study evaluated the efficacy of politzerization with an automated, hand-held
device that controls volume velocity (airflow) in the treatment of 20 children
with otitis media with effusion. These patients underwent politzerization twice a
week for up to 6 weeks. Another 20 children with otitis media with effusion who
were not treated with politzerization served as controls. Following treatment,
resolution of the average air-bone gap to within normal limits was achieved in
70% of the treated group and 20% of the controls, which eliminated the need for
grommet insertion in these patients. Improvement in tympanometric peak pressure
was also significantly greater in the treated group. Politzerization was
efficiently and successfully performed in all patients. The automated device's
ease of administration and its ability to control airflow suggests that it has
the potential to be an effective home treatment that can be administered by the
parents or guardians of children who have otitis media with effusion.
PMID- 10786394
TI - Superior adenoidectomy in children with palatal abnormalities.
AB - When treating a child with a palatal abnormality for otitis media or a nasal
obstruction, otolaryngologists often face the question of whether the benefits of
adenoidectomy are worth the risk of the development of velopharyngeal
insufficiency. Treatment options for these patients include a complete
adenoidectomy, a partial adenoidectomy, or no surgical intervention. In this
retrospective study, we describe the outcomes of 22 such patients who were
treated with a superior adenoidectomy performed with a St. Clair adenoidforceps
under indirect vision with a laryngeal mirror. All patients experienced a
complete or near-complete resolution of their nasal obstruction, and none
developed permanent velopharyngeal insufficiency. Only three patients experienced
a recurrence of otitis media. Our experience suggests that superior adenoidectomy
is a safe and effective procedure.
PMID- 10786395
TI - Management of the unknown primary in patients with metastatic cancer of the head
and neck.
AB - The evaluation of the patient with metastatic cervical lymph node squamous cell
carcinoma and an unknown primary tumor frequently involves the use of guided
biopsies as a diagnostic tool. This study was performed to assess the
effectiveness of these biopsies. Using a retrospective chart review, we
identified 25 patients who had undergone a total of 100 guided biopsies to
evaluate an unknown primary malignancy of the head and neck. We found that 99 of
the 100 biopsies were negative for malignancy. Although guided biopsies were
obviously not helpful in these cases, we believe this might be attributable to
the fact that the method of performing them is inconsistent among surgeons.
Therefore, we present an algorithm for the management of the unknown primary head
and neck malignancy, including recommendations regarding the use of guided
biopsies.
PMID- 10786396
TI - Removal of a fish bone in the thyroid gland without the need for thyroid
lobectomy.
AB - We report the first published case of the removal of a migratory fish bone from
the thyroid gland that did not necessitate a thyroid lobectomy.
PMID- 10786397
TI - Pneumoparotid: a case report and review of its pathogenesis, diagnosis, and
management.
AB - Pneumoparotid is considered to be a rare entity, but the diagnosis might not be
as uncommon as reported. We report a case in which computed tomography
incidentally revealed air in the parotid ducts bilaterally. Treatment is aimed at
the elimination of predisposing and causative factors, but because our patient
denied any symptoms or precipitating factors and had a benign presentation, no
immediate intervention was initiated.
PMID- 10786398
TI - [HPV viral typing].
PMID- 10786399
TI - [The Human Genome Project and the genetics of infertility].
AB - Nine years after the beginning and five years before the expected end of the
Human Genome Project, we will have access in several months to 90% of the human
genome sequence. This data certainly opens promising vistas to the better
understanding of gametogenesis. This will allow the different types of sterility
to be studied through new approaches. The aim of the current review is to
describe how the Human Genome Project has proceeded in the last ten years. We
also discuss to what extent the knowledge of the human genome sequence is
important in understanding the genetic basis of some diseases, such as human
infertility. Finally, we review the different methodologies to use this
information and their limits.
PMID- 10786401
TI - [Therapeutic management of ovarian dystrophy and insufficiency in abortion
disorders: recent data].
AB - Many reports suggested that the high rate of miscarriage in women with polycystic
ovaries may be due to increased urine and/or plasma LH concentration. In fact,
with the exception of pulsatile GnRH, any treatment likely to increase the plasma
LH level results in unchanged or rather low miscarriage rates. Conversely, a
reduction in this rate by GnRH agonists is not conclusive. Excess weight may also
increase the risk of miscarriage. In women with incipient ovarian failure, the
miscarriage rate is mainly linked to age. No stimulation has been found to be
effective in these patients. There is a need for more extensive evaluation in
GnRH analog microdoses, recombinant FSH and GnRH antagonists. Oocyte donations
from younger women are difficult to obtain because of the lack of donors in
France.
PMID- 10786400
TI - [Hormone replacement therapy after endometrial or ovarian cancer].
AB - Use of hormonal replacement therapy after treatment of ovarian or endometrial
cancer remains a matter of debate. Novel adjuvant therapies tend to increase the
survival of these patients, who are exposed to risk factors of hormonal
deficiency subsequent to primary therapy. Therefore, the aims of the present
review of literature was to analyse epidemiologic and clinical parameters on
behalf on hormonal replacement therapy in this population.
PMID- 10786402
TI - [Future perspectives: oocyte cryopreservation and in vitro maturation].
AB - After treatment for neoplasia, a young patient can nowadays hope to be pregnant.
The aim of this paper is to establish a review of the literature about
cryopreservation of oocytes and ovarian tissue, and in vitro maturation of
oocytes. These studies also concern patients for which ovarian stimulation is
difficult, such as PCOS. These techniques could also facilitate the creation of
an oocyte bank as the one already existing for sperm. So far the main studies
published, in spite of very timid first results, allow us to look to a great
future for cryopreservation and in vitro maturation of oocytes.
PMID- 10786403
TI - [Prognostic factors for survival of ovarian epithelial cancers: apropos of 287
cases].
AB - OBJECTIVES: To evaluate survival and assess prognostic factors in patients with
epithelial ovarian cancer. METHODS: Retrospective analysis of 287 patients
treated between 1975 and 1995. All operations were performed by senior surgeons.
Histologic sections were reviewed by the same pathologist. Successive adjuvant
chemotherapy regimens are described. Survival was evaluated in 1997. Follow-up
lasted 25-260 months (median 90). Statistical methods included Kaplan-Meier
survival curves, logrank test and multivariate analysis. RESULTS: The five-year
survival rates 76%, 42%, 21% and 6% for patients with stage I, II, III and IV
disease, respectively. Age, FIGO stage, cytology of ascites, histologic type and
grade, extent of surgery and number of residual tumors were significant
prognostic indicators in univariate analysis. Multivariate analysis showed that
the risk of mortality was reduced by 57% for patients whose tumor distribution
permitted optimal surgery (RR = 0.43, 95% CI [0.29-0.64]; P < 0.001). The risk of
mortality according to FIGO stage was 2.8 (95% CI [1.2-6.3]; P = 0.01) for FIGO
II, 5.6 (95% CI [2.9-10.8]; P < 0.001) for FIGO III and 10.5 (95% CI [4.9-22.1];
P < 0.001) for FIGO IV in comparison with FIGO I. The risk of mortality for
patients treated with alkylating agents, platinum-based combination chemotherapy
taxanes or carboplatin plus paclitaxel regimen compared with patients who did not
receive treatment was reduced by 47% (95% CI [8%-69%]; P = 0.025), 55% (95% CI
[22%-74%]; P = 0.005) and 70% (95% CI [35%-86%]; P = 0.002), respectively.
Patients with a serous epithelial carcinoma had a 1.7-fold higher risk of
mortality than patients with other histologic types (RR = 1.7, 95% CI [1.1-2.8];
P = 0.02). CONCLUSION: Our study confirms the benefit of cytoreductive surgery
and the efficacy of platinum plus paclitaxel first-line chemotherapy, which has
recently been recognized as the standard treatment for advanced epithelial
ovarian cancer.
PMID- 10786404
TI - [Laparoscopy and bladder endometriosis].
AB - Partial cystectomy is in the great majority of the cases the treatment of choice
for patients with bladder endometriosis. The aim is to assess the methods,
indications and results of operative laparoscopy for patients presenting with
bladder endometriosis. We perform a descriptive retrospective study of 13 cases.
All patients presenting with bladder endometriosis infiltrating the bladder
muscularis between January 1, 1993 and June 30, 1998 were included in this
series. It was possible to treat bladder endometriosis in all the patients by
performing a laparoscopic partial cystectomy. With an average follow-up of 29.3
+/- 24.6 months (range 4-77) the results are satisfactory. Neither peri- nor
postoperative complications were observed. The patients experienced an
improvement in their condition, with complete disappearance of the urinary
symptoms in every case. No recurrence of the functional urological symptoms
occurred. Provided the surgeons are skilled and the lesions require no ureteral
reimplantation, operative laparoscopy is a valid alternative to laparotomy for
partial cystectomy.
PMID- 10786406
TI - [Vaginal dryness in the menopausal woman (physiological and psychological
aspects)].
PMID- 10786405
TI - [Evaluation of the efficacity and speed of action of sertaconazole nitrate
suppository and cream combined treatment for vulvovaginal candidiasis].
AB - OBJECTIVE: To assess efficacy and speed of action of a monodose sertaconazole
vaginal suppository administered as a single treatment or combined with
sertaconazole cream applied to the vulvar area. METHODS: This prospective,
multicentric, randomised open study was conducted on 77 women with vulvovaginal
candidiasis confirmed by mycological examination. They were either treated with
one sertaconazole monodose vaginal suppository only (group O) or treated with the
suppository combined with sertaconazole cream applied to the vulvar area for 7
days (group OC). The patients who were not clinically cured at D7 received a
second phase of treatment. RESULTS: Clinical cure rates were higher in group OC
than in group O at D7 (76% versus 68%), and D14 (100% versus 80%). The efficacy
on symptoms was faster in group OC, with 78% of the patients relieved of pruritus
as early as D2 versus 61% in group O, although these differences were not
significant. Clinical local tolerance was very good, with 95% of patients not
experiencing any local side effects. CONCLUSION: When candidiasis is both vulvar
and vaginal, the combination of sertaconazole cream with a monodose sertaconazole
vaginal suppository tends to improve clinical cure at D7 and D14 and to relieve
more patients as early as D2 than the vaginal suppository used as a single
treatment.
PMID- 10786407
TI - [Cervico-uterine cytology in liquid media: procedures and results of the ThinPrep
Pap Test].
PMID- 10786408
TI - [How should we consider luteal insufficiency in fertility?].
PMID- 10786409
TI - Peer-led and adult-led programs--student perceptions.
AB - This research examines whether peer-led prevention programs are preferable to
adult-led programs. Participants were 2,447 students in 94 classes, from 31
schools running drug prevention programs. The schools were divided into two
groups according to the model they used in their program: fifteen schools used
peer-led model, while sixteen used the adult-led model. A 46-item questionnaire
was constructed in order to examine the students' perception of the programs. The
results show that all the input measures (content, atmosphere, openness,
discipline, facilitators' competence) and the outcome measures (satisfaction,
knowledge, avoidance, curiosity, personal relationship) were perceived as more
positive in the peer-led model. The differences were small, but significant.
While the findings suggest that the peer-led model has a somewhat greater
potential for primary prevention, the differences found do not enable us to state
with certainty that this model is preferable for primary prevention purposes.
PMID- 10786410
TI - "I'Ve had too much done to my heart": the dilemma of addiction and recovery as
seen through seven youngsters' lives.
AB - Aware of the dearth of in-depth studies on recovering adolescent
addict/alcoholics, we conducted a year-long qualitative study of seven formerly
addicted youth committed to recovery. The research question was: how do addicted
youth become and remain sober? Bending to social stress, including racism and
ethnic prejudice, three participants relapsed. However, personal commitment
augmented by familial, community, spiritual, and educational support encouraged
four to remain sober. Learning from both those who failed and succeeded, the
theoretical concepts of surrender, social stress, and resiliency helped to
interpret the participants' patterns of response and better understand adolescent
recovery.
PMID- 10786411
TI - Preventing alcohol abuse: an examination of the "Downward Spiral" game and
educational videos.
AB - Downward Spiral is a board game developed by the authors to illustrate the
dangers of continued substance abuse. Previous work has found that college
students and probationers find the game interesting, enjoyable, useful, and
realistic [1]. In the current study, college students either played Downward
Spiral, watched educational videos on substance abuse, or completed a set of
questionnaires unrelated to alcohol and drug abuse. Those students who either
played the game or watched the videos rated both as beneficial. However, students
who watched videos had somewhat higher levels of consumer satisfaction. Students
who played the game rated it as smoother, and they felt more positive following
the session than students who watched videos. Both videos and the game increased
students' intentions to limit alcohol consumption compared to students who served
as controls. Individuals in the game group also indicated significantly greater
intentions to change their alcohol behavior than those in the other groups.
PMID- 10786412
TI - Factors in marijuana cessation among high-risk youth.
AB - The rise in marijuana use among high school students has generated considerable
concern. The apparent failure of current marijuana control efforts may be due in
part to ignorance about why students use marijuana and what influences them to
consider quitting. This article utilized both open-ended and multiple-choice
surveys as well as health educator-led focus groups to assess issues related to
marijuana use and cessation among a population of high-risk youth. A total of 842
students participated, assessed as two separate samples from eleven continuation
high schools in southern California. Approximately 70 percent of the students are
current marijuana users. Interpreting results across both samples, it is apparent
that interest in quitting marijuana use among continuation high school students
is high. Over half of the marijuana users surveyed have tried to quit and failed.
Still, several social images associated with marijuana smokers are positive and
subjects express a lack of confidence in the efficacy of marijuana cessation
clinic programs. Subjects believe that either self-help or punitive methods are
the most effective types of marijuana cessation activities. A reportedly high
rate of failed quit attempts suggests that effective marijuana cessation programs
are needed in this population. Future programs must address both reasons users
resist change, including use of marijuana as a stress reliever, and the
particular motivations that subjects report regarding why they desire to quit
using marijuana, including legal, vocational, and health consequences.
PMID- 10786413
TI - Effectiveness of refusal skills software.
AB - This research explores the potential of making social skills training more
accessible to schools by the use of computer-aided instruction. An easy-to-use
software program called Refusal Challenges, which targets important social skills
with effective training methods, was tested. The dependent measure was
demonstration of refusal skills strategies. One-hundred-eighty-eight male and
female eighth-grade students were stratified according to pre-treatment refusal
skill level, gender, and teacher. They were then randomly assigned from the
stratified blocks to either the computer-based refusal skills training group or a
control group. Repeated measures analyses of variance indicated a significant and
meaningful time by treatment interaction for refusal skills scores. The
difference between treatment and control groups remained significant and
meaningful at both the post-test and follow-up testing.
PMID- 10786414
TI - Prevention training of paraprofessionals in the schools: an examination of
relevancy and effectiveness.
AB - Prevention training programs for paraprofessional school personnel are examined
in this article. Prevention training for the reduction of student alcohol and
other drug use, incorporating a student well-being model, is described and
evaluated. The prevention training, entitled "Enhancing Student Well-Being," took
place in two urban school districts with over 200 paraprofessional school
personnel participating. The training was evaluated using measures of knowledge
gained, self-efficacy, and participant satisfaction. Pre- and post-training
differences showed consistent gains in participant efficacy expectations but less
consistent gains in outcome expectations and knowledge. Participant satisfaction
and self-reports of knowledge enhanced and skill improvement were uniformly high
across all training programs. Implications for inservice prevention training of
paraprofessionals are discussed.
PMID- 10786415
TI - Favourable outcome of a case of pulmonary Langerhans' cell histiocytosis.
AB - Pulmonary Langerhans' cell histiocytosis and eosinophilic granuloma are the terms
used to describe a Langerhans' cell granulomatous interstitial lung disease of
unknown aetiology, occurring predominantly in smokers and involving primarily
lungs, bones, skin and lymph nodes. In this report a patient with fever, fatigue,
dyspnoea, nocturnal perspiration and thoracic pain is described. The high
resolution computed tomography of the chest and histological examination of lung
biopsies suggested the diagnosis of pulmonary Langerhans' cell histiocytosis. The
disease was limited to the lung, since further investigations did not show any
other localization. The patient had a good clinical outcome with avoidance of
smoking and steroid therapy. The computed tomography scan follow-up showed a
partial resolution of pulmonary lesions.
PMID- 10786416
TI - Endobronchial metastasis from stomach carcinoma.
AB - We describe the case of a 57-yr-old female with endobronchial metastasis from
stomach carcinoma. Respiratory symptoms began 3 months before the diagnosis of
the gastric cancer. Chest computed tomography revealed a reticular lymphangitic
carcinomatosis pattern with hilar and mediastinal lymphadenopathy. Fibreoptic
bronchoscopy showed a spread submucosal infiltration which narrowed the apical
segment of the left lower lobar bronchus. The biopsy specimen at that level was
histologically identical to the gastric primitive cancer. To the authors'
knowledge, stomach carcinoma has rarely been reported to give rise to airway
metastases.
PMID- 10786418
TI - Investigating pleural disease.
PMID- 10786417
TI - Commercial polymerase chain reaction test (Amplicor set) in the diagnosis of
smear-negative pulmonary tuberculosis from sputum and bronchoalveolar lavage.
AB - The study presents experience with polymerase chain reaction (PCR) in the
diagnosis of tuberculosis (TB) and compares the results obtained in sputum and
bronchoalveolar lavage fluid (BALF). A total of 1,097 samples from 846 smear
negative patients with suspected TB was examined using PCR and culture during a
period of 40 months. TB was the final diagnosis in 160 patients, based on the
evidence of mycobacteria in 90 patients and on clinical criteria in the remaining
70. The PCR test had high specificity (98% and 99%, respectively) but poor
sensitivity (37% and 34%, respectively) regardless of whether sputum or BALF was
examined. Surprisingly, the sensitivity of culture (44% and 35% in sputum and
BALF, respectively) was higher than that of PCR in this group. The contribution
of BAL to establishing the diagnosis of tuberculosis was rather limited, yet
substantial in some patients. The results obtained in this study were compared
with the results published in the literature, and it was concluded that further
clinical studies are necessary to establish an appropriate role for the
polymerase chain reaction in the diagnosis of tuberculosis.
PMID- 10786419
TI - Malignant pleural diseases.
AB - The incidence of malignant pleural effusions has been increasing over the last
few decades (mainly due to the absolute increase in several types of cancers,
especially those of lung and breast origin) and they account for up to 50% of the
exudates in many clinical series. Although pleural malignancies are thought to
present most frequently with a pleural effusion, several autopsy series,
including the current one, found a pleural effusion present in little more than
half of the cases of malignant pleural involvement (55% in this series). Thus,
many pleural malignancies without effusion might pass unnoticed in clinical
practice, especially in metastatic disease. Primary malignancies of the pleura
(mesotheliomas) are associated with asbestos exposure in about two-thirds of
cases, and they frequently present with chest pain, sometimes associated with a
pleural effusion. Benign pleural plaques can coexist with malignant mesothelioma,
and this association should be suspected when long-standing plaques change in
shape or size over the years, and especially if chest pain develops in a
previously asymptomatic patient. Metastatic pleural involvement is much more
frequent than mesotheliomas, and its most frequent mechanism is the vascular
spreading of tumour cells from distant organs to the lungs, and on to the
visceral and parietal pleura. The visceral pleura was involved in up to 87% of
the current metastatic cases, whereas the parietal zone in only 47% of the
autopsy series. The diagnostic work-up lies in cytology, whose average yield is
approximately 50%, and a biopsy technique (either by blind needle biopsy or
thoracoscopy) is recommended when the effusion persists, for > 2 weeks, and the
first cytology has been negative. Thoracoscopy has the additional advantage of
allowing pleurodesis with talc poudrage if clear tumour lesions are found in the
pleura. In cases of malignant effusion which are not sensitive to chemotherapy,
pleurodesis is the treatment of choice for palliation of symptoms, and talc is
the most effective agent. It can be used either in suspension ("slurry") or in
dry aerosolized form ("talc poudrage"), but it seems that this last technique
achieves the best effects. However, it requires thoracoscopy for a proper
application, and this is its main drawback when that technique is not readily
available.
PMID- 10786420
TI - Management of infectious pleural diseases.
PMID- 10786422
TI - Transbronchial needle aspiration of mediastinal lesions.
PMID- 10786421
TI - Tracheobronchial stents.
PMID- 10786423
TI - Bronchoscopic early detection of lung cancer.
PMID- 10786424
TI - Endobronchial ultrasound of the airways and the mediastinum.
PMID- 10786425
TI - Nasal ventilation: where are we?
PMID- 10786426
TI - Noninvasive ventilation in intensive care unit patients.
PMID- 10786427
TI - Noninvasive ventilation in COPD patients with chronic respiratory failure--pro.
PMID- 10786428
TI - Lung involvement in organic dust exposure.
PMID- 10786429
TI - Early detection of occupational asthma and reactive airways dysfunction syndrome.
PMID- 10786430
TI - Dynamics and clinical effects of nonferrous metals in the human body.
AB - Pollution from toxic metal fumes and dusts occurs in many industrial situations.
Exposed workers may experience occupational diseases directly related to
poisoning from metallic elements. Studies have shown that the major route of
absorption of metals is by inhalation. Once absorbed, distribution to various
tissues and excretion from the body differ between metals. Multiphasic retention
times have been described for many metals with a proportion of the body burden
being eliminated very slowly. Biological half-lives range across many years.
Whilst blood or urine levels of metals may reflect current exposure, once
exposure ceases these levels may not be good indicators of remaining body burden.
Acute and chronic health effects occur after exposure. A wide range of chronic
disease including many respiratory diseases (emphysema, lung cancer, chronic
obstructive pulmonary disease, fibrosis and asthma), together with neurological,
haematological, hepatotoxic and nephrotoxic effects, has been reported.
PMID- 10786431
TI - How to set the ventilator in asthma.
AB - All patients with bronchial asthma are at risk of developing severe episodes of
airway narrowing that do not respond to the usual medical treatment, a life
threatening situation referred to as status asthmaticus. In some cases,
ventilatory failure occurs, necessitating mechanical ventilation to support gas
exchange and to unload the respiratory muscles, giving time for other therapeutic
interventions to improve the functional status of the patient. Mechanical
ventilatory support poses additional risks to the patients, due to interaction
between the pathophysiology of the disease and the process of mechanical
ventilation. Dynamic hyperinflation, a cardinal feature of the pathophysiology,
may cause serious complications during mechanical ventilation. Setting the
ventilator, such as to minimize the dynamic hyperinflation, is a key point in the
management of mechanically ventilated patients with status asthmaticus.
Strategies to reduce dynamic hyperinflation, such as hypoventilation (permissive
hypercapnia), increase of expiratory time and promotion of patient-ventilator
synchrony are mandatory and significantly decrease the morbidity and mortality of
the disease. Continuous monitoring of the effectiveness of these strategies, as
well as the functional status of the patient, is crucial in order to limit
complications associated with mechanical ventilation and to identify the time
that weaning can start.
PMID- 10786432
TI - Ventilator settings in acute respiratory failure/acute respiratory distress
syndrome.
PMID- 10786433
TI - Medical and nursing boards adopt CRNP regs.
PMID- 10786434
TI - Medicare HMO capitation plan affects physicians in many counties.
PMID- 10786435
TI - Pointing out simple truths.
PMID- 10786436
TI - Cancer care challenge.
PMID- 10786437
TI - Serotonin syndrome.
PMID- 10786438
TI - Cut out the middleman.
PMID- 10786439
TI - Giving back to medicine.
PMID- 10786440
TI - Suggestions for clarity in medical writing.
PMID- 10786441
TI - Guidelines for young child feeding in the Caribbean--Part I. Caribbean Food and
Nutrition Institute.
AB - The guidelines for young child feeding have been developed and prepared as a
supportive-tool primarily for health personnel involved in the care of infants
and children in Caribbean countries. The recommendations address some practical
aspects of nutrition before, during and after pregnancy. These are: The benefits
of breastfeeding and strategies for its promotion, protection and support; review
of infant feeding options for mothers with HIV and other infections; nutrition of
the newborn; feeding of low birth weight infants and those with special
requirements; replacement feeding for infants who are not breastfed;
complementary feeding with emphasis on the continuation of breastfeeding for two
years and beyond; guidelines on vitamin and mineral supplementation; management
of feeding-related problems in early childhood; policy issues and nutrition
education in relation to the promotion of adequate nutrition in early childhood.
PMID- 10786442
TI - Measurement of lung inflammation in asthmatics. Reason for optimism.
AB - It is recognized that bronchial asthma is an inflammatory disease. However,
aggressive anti-inflammatory therapy is not guided by the degree of lung
inflammation. This is of particular concern in children in whom over-aggressive
therapy with corticosteroid may lead to growth retardation. Analysis of breath
exhaled nitric oxide levels may be an indirect measurement of lung inflammation.
Since exhaled nitric oxide levels and inflammation decrease after steroid
therapy, measurement of exhaled nitric oxide levels may provide a rationale for
optimization of steroid therapy and possible reduction of side effects.
Measurement of exhaled nitric oxide levels is not available for routine use but
may be so in the near future. This will likely herald a new dawn in the
management of asthma, a disease with increasing frequency, mortality and
morbidity.
PMID- 10786443
TI - The University of the West Indies. Research limitations, research imperatives.
Whither the faculty of medical sciences?
PMID- 10786444
TI - The University of the West Indies School of Dentistry.
PMID- 10786445
TI - The vegetarian/vegan lifestyle.
PMID- 10786446
TI - An experimental mouse model to study the pathogenicity of Prevotella bivia and
investigations of possible virulence.
AB - Induction of subcutaneous abscesses in mice was used to study the pathogenicity
of Prevotella bivia both in mono-infection and in mixed cultures with Escherichia
coli and Peptostreptococcus spp. Virulence factors such as coaggregation and
aggregate formation of cells, haemagglutination activity and tolerance to serum
bactericidal activity were investigated for their possible role in P bivia
pathogenicity. Monocultures of P bivia, E coli and Peptostreptococcus spp did not
induce subcutaneous abscess at concentrations as high as 10(9) colony forming
units/millilitre (cfu/ml). Only E coli persisted at the infection site for up to
7 days post infection but with a marked decline in cell count (8.0 x 10(2)
cfu/ml). The anaerobic organisms did not persist at the infection sites beyond
the fifth day. In contrast, mixed cultures of P bivia and E coli or all three
organisms potentiated for infective abscess two weeks after infection. Viable
cells were recovered from abscesses in greater numbers as the infection
progressed. Prevotella bivia was the predominant organism in chronic abscesses
while E coli predominated in abscesses in the acute stage of the infection.
Prevotella bivia lacked haemagglutination activity against human and sheep
erythrocytes and showed marked susceptibility to 50 per cent human serum. These
may limit its haematogenous spread. Its ability to form aggregates in molar salt
solutions and coaggregate with facultative organisms may account for its
persistence in pathological sites.
PMID- 10786447
TI - The antihypertensive effects of the Jamaican Cho-Cho (Sechium edule).
AB - The experiments reported in this study constitute a preliminary investigation
into the possible hypotensive effect of the Jamaican Cho-Cho (Sechium edule).
Experiments were conducted in a random and blind fashion on two sub species of
Sechium edule. Both the pulp and the peel were examined for hypotensive activity.
Water-soluble extracts were prepared from these components of the fruit and
injected into anaesthetised rats. Various cardiovascular parameters were measured
including heart rate, mean arterial pressure (MAP) and several ECG intervals. We
report that all extracts tested produced a fall in blood pressure with little
change in ECG intervals. Extract B produced the least change in heart rate with a
fall in MAP of approximately 23 mmHg. Changes in heart rate with all extracts
appeared to be minimal as an ED25 value could only be determined for extract A,
and ED10 values could not be evaluated for extracts C and D. The mechanism(s) by
which these extracts produce their hypotensive effects could not be determined in
these preliminary experiments. However, it appears not to involve direct effects
on cardiac tissue. This conclusion is based on the finding that it took a minimum
of 10 to 15 seconds for the hypotensive action to manifest post bolus. Future
experiments will be aimed at delineating the mechanism(s) involved in decreasing
MAP.
PMID- 10786448
TI - Topical use of papaya in chronic skin ulcer therapy in Jamaica.
AB - The objective of the study was to determine the prevalence of the use of the
fruit (papaya) of Carica papaya as topical ulcer dressings by registered nurses
in the Spanish Town Hospital (STH), Kingston Public Hospital (KPH) and the
University Hospital of the West Indies (UHWI), Jamaica. A ten-item pretested self
administered questionnaire was distributed to 285 randomly selected registered
nurses at the UHWI, KPH and STH. There was a 72% response rate. The prevalence of
topical papaya use among the respondents was 75%. Comments from the users of
papaya suggested that topical application of the unripe fruit promoted
desloughing, granulation and healing and reduced odour in chronic skin ulcers. It
was cost effective. Papaya was considered to be more effective than other topical
applications in the treatment of chronic ulcers. There was some difficulty in
preparation of the fruit and occasionally a sensation of burning was reported by
the patients. There was concern about the use of a non-sterile, non-standardised
procedure but there were no reports of wound infection from its use. Papaya is
widely used by nurses as a form of dressing for chronic ulcers and there is need
for standardisation of its preparation and application.
PMID- 10786450
TI - Formal handling routines in Jamaican infants. Knowledge, attitudes and behaviour.
AB - This study aimed to determine the frequency of use and the knowledge, attitudes
and behaviour regarding the Formal Handling Routines (FHR) in rural and urban
Jamaican infants. Analysis was made of the area of residence and educational
level of the caregivers. The study included 194 caregivers, thirty-three
community rehabilitation workers (CRWs) and 30 health care workers (HCWs).
Depending on the level of understanding of the respondents, questionnaires were
either self-administered or a personal interview was conducted. Caregivers with
tertiary education differed significantly from the other caregivers both in
frequency of use of the FHR and knowledge, attitudes and behaviour. Caregivers
with tertiary education used the routine much less and had more negative
attitudes towards it. This might be due to their better financial position, which
allowed them to have helpers who cared for their children. HCWs also had
significantly more negative beliefs about the FHR than CRWs and caregivers. It is
possible that HCWs carried over their knowledge, attitudes and behaviour to the
caregivers but if they did, it did not influence the majority of caregivers.
PMID- 10786449
TI - Dialysis adequacy at two haemodialysis units in Jamaica.
AB - A prospective study on adequacy of dialysis was conducted at the haemodialysis
units of Kingston Public Hospital (KPH) and the University Hospital of the West
Indies (UHWI). Dialysis adequacy was better at KPH and morbidity, as measured by
patient admission days, was increased at UHWI. Diabetics had a lower mean serum
albumin and urea reduction ratio (URR) than non-diabetics. Multiple regression
analyses revealed that age of patient (F = 5.30; p = 0.0241) and hospital (F =
7.85; p = 0.007) were the variables significantly associated with serum albumin
level when the effect of other variables was controlled (F = 2.12; p = 0.34).
Similar analyses showed that the hospital at which dialysis was done was the only
factor which accounted for significantly higher URR, with KPH having higher rates
(F = 13; p = 0.006). The differences between hospitals necessitate further
investigations, explanations and intervention strategies. The study provides
opportunities for improving patient care and for dialysis health care
professionals to assess clinical performance measures and reduce variation
between dialysis centres.
PMID- 10786451
TI - HIV infection among children in Barbados.
AB - We studied a cohort of children with the human immunodeficiency virus (HIV)
infection in Barbados in order to determine the prevalence of HIV infection, the
clinical course including morbidity and mortality and the magnitude of the health
care and social problems. Forty-seven children were diagnosed with HIV infection
during the study period. The number of HIV infected children increased from 5
during 1981-85, to 14 during 1986-90, and to 21 during the 1991-95 period. The
majority (91.5%) of infections resulted from perinatal transmission. Six (12.8%)
cases remained asymptomatic and 41 (87.2%) were symptomatic with 19(46.3%)
presenting in infancy, while 22 (53.5%) presented post-infancy. The median age at
diagnosis (class P-2) was 13 months. Generalized lymphadenopathy (47.5%),
hepatosplenomegaly (40.0%), failure to thrive (27.5%), persistent recurrent
diarrhoea (15.0%), oral candidiasis (37.5%), Pneumocystis carinii pneumonia
(37.5%), lymphoid interstitial pneumonia (12.5%) and progressive neurological
disease (10.0%) were common HIV related conditions. Two children developed non
hodgkin's lymphoma. The median age at death for 23 children was 12 months,
whereas the median survival after diagnosis was 4 months. Mortality was higher
among those diagnosed in infancy (73.7%) as compared to those diagnosed post
infancy (42.8%). Pneumocystis carinii pneumonia was the most common (65.2%) cause
of death. Paediatric HIV infection is rising and contributes considerably to
infant mortality. In this study, children took longer to be symptomatic when
compared to other reports. However, once symptomatic, they died early.
PMID- 10786452
TI - Children's response to hospitalization at the University Hospital of the West
Indies.
AB - The results of this study indicated that patients aged 3-13 years who had a
history of previous hospitalization appeared to be significantly more distressed
than patients without such previous history (p < 0.05). Previously hospitalized
children were more uncooperative and displayed anxious, immature behaviour
patterns. Children who were hospitalized for more than a month were also
interviewed about their concerns and response to hospitalization. The study
highlighted the need for hospitalized children to be better prepared for
hospitalization, to have greater parental involvement in the management of their
behaviour and to have efficiently run programmes geared at addressing their
educational and emotional needs.
PMID- 10786453
TI - Psychological distress among younger siblings of patients with homozygous sickle
cell disease in the Jamaican cohort study.
AB - The presence of a chronically ill family member may adversely affect the
psychological health of siblings. This study used the General Health
Questionnaire and the Modified Social Adjustment Scale to assess psychological
distress in 20 younger siblings (4 AA, 16 AS genotypes), aged 16-19 years, of
patients with homozygous sickle cell (SS) disease. The results were compared with
those previously obtained in the 20 older siblings with SS disease and in 89
controls with a normal haemoglobin (AA) genotype. High levels of psychological
distress occurred among all three groups. Greater psychological distress and
poorer social adjustment occurred among siblings compared to AA controls but
these differences disappeared after adjusting for the reduced age of siblings.
The two measures were similar in SS patients and AA controls. The level of
psychological distress among siblings of SS patients did not differ from that in
SS patients or AA controls.
PMID- 10786454
TI - Knowledge, attitudes and practices of anabolic steroid usage among gym users in
Trinidad.
AB - Self-administered questionnaires were completed by 1062 gym-users in 14 gyms in
Trinidad from February 1997 to July 1997 to determine the knowledge, attitudes
and practices regarding anabolic steroids (AS). Five hundred and sixty (52.7%)
females and 502 (48.3%) males completed the questionnaire. Half of the total
sample were individuals in the 20 to 29 year age group. From the 17 questions
that tested knowledge about AS, the median number of correct responses was 7 with
a mode of 8. Increased muscle mass was correctly identified as one of the effects
of AS by 841 respondents (79.2%), while 249 (23.6%) of the total sample thought
asthma was treated with AS. Most (872 or 82.1%) felt that their knowledge about
AS was inadequate and 700 (66.0%) were of the opinion that AS should be banned
from use in competitive sports. Similarly, 733 (70.0%) of the gym-users thought
AS should only be available by prescription. Thirty respondents reported having
used AS (2.9%, 95% CI 2.0-4.1). The prevalence of AS use was higher among males
than females (p < 0.001). Improvement of physical appearance and not competitive
advantage in sport was the main reason cited for AS use. Anabolic steroid users
knew more about the adverse effects of AS than non-AS users but the therapeutic
uses of AS were comparatively less well known. This study demonstrated a general
lack of knowledge concerning AS use and that a small but significant proportion
of persons using gyms admitted to abusing AS.
PMID- 10786456
TI - A retrospective analysis of invasive Streptococcus pneumoniae infections in
Trinidad.
AB - A retrospective analysis of culture-positive cases of S pneumoniae from normally
sterile body fluids is reported. Over 40% of patients were 5 years old or less
while 28% of patients were 50 years old or more. Meningitis (44%) was the
commonest clinical presentation followed closely by pneumonia (31%). The
commonest predisposing disorder was human immunodeficiency virus infection though
there were no identifiable risk factors in the majority of patients. Mortality
from invasive pneumococcal disease was significantly higher in elderly patients
compared with other age groups (p = 0.0003). In this study, all S pneumoniae
isolates, for which there were antibiotic sensitivity data, were penicillin
and/or amoxycillin sensitive.
PMID- 10786455
TI - Solid and papillary epithelial neoplasm. Ultrasound and CT features of an unusual
pancreatic tumour.
AB - The ultrasonographic and computed tomography features of four cases of solid and
papillary epithelial neoplasm (SPEN)--a rare pancreatic tumour--are described.
Although not diagnostic, the presence of these imaging features in the typical
clinical setting may permit pre-operative radiological diagnosis and facilitate
planning for curative surgery for this malignant tumour which has an excellent
prognosis even without further adjuvant therapy.
PMID- 10786457
TI - Images and diagnoses. Phaeochromocytoma from paraganglia of the urinary bladder
wall.
PMID- 10786458
TI - Images and diagnoses. Ainhum.
PMID- 10786459
TI - Malignant meningioma with extension into the neck.
AB - One per cent of all brain tumours and twenty per cent of meningiomas eventually
develop an extracranial extension. The least common site is the neck. We report a
case of malignant meningioma with extension into the neck of a 39-year-old male.
PMID- 10786460
TI - Tuberculous encephalopathy. A rare complication of pulmonary tuberculosis.
AB - A case of tuberculous encephalopathy, a rare form of neuro-tuberculosis, is
reported in a 16-year-old girl who had pulmonary tuberculosis and extensive
cerebral demyelination. The clinical, laboratory and pathological features of
this entity are highlighted and the pathogenesis discussed.
PMID- 10786461
TI - Use of magnesium sulphate as adjunctive therapy for resection of
phaeochromocytoma.
AB - The intraoperative control of cardiovascular disturbances associated with the
resection of phaeochromocytoma is traditionally achieved by the use of deep
anaesthesia in conjunction with alpha and beta blockers, calcium antagonists,
nitroglycerine or sodium nitroprusside. We report the successful use of magnesium
sulphate as adjunctive therapy in the control of the cardiovascular consequences
associated with surgical resection of a phaeochromocytoma in a patient.
PMID- 10786462
TI - Extraadrenal retroperitoneal paraganglioma causing malignant hypertension and
permanent visual loss in an eleven-year-old girl.
AB - We report a secretory paraganglioma in an eleven-year-old Trinidadian girl of
East Indian descent who presented with malignant hypertension, proteinuria and
modest elevation of urinary vanillylmandelic acid levels. The extra-adrenal mass
was surgically removed without complications. The patient has been normotensive
without evidence of recurrence of disease but with persistent visual sequel two
years later. This case reinforces the observation that extraadrenal
retroperitoneal paragangliomas can be functionally very active and early computed
tomography or other imaging procedure is necessary for rapid noninvasive
evaluation, timely surgery and prevention of permanent morbidity.
PMID- 10786463
TI - Systemic phaeohyphomycosis in pregnancy and the puerperium.
AB - Systemic fungal infections are rare. In pregnancy, treatment is problematic
because of the risk of possible teratogenic effects of the antifungal drugs. We
present the case of a 32 year-old woman who presented during pregnancy with a two
month history of painless subcutaneous nodules. Excision biopsy of one lesion
showed dematiaceous fungal elements. Anti-fungal treatment was deferred and the
pregnancy proceeded uneventfully. The remaining nodules were excised at the time
of caesarean section delivery. Three weeks into the puerperium, she developed
generalised seizures and investigations indicated systemic fungal infection with
positive cultures for Aureobasidium spp which responded to appropriate antifungal
therapy of flucytosine and itraconazole.
PMID- 10786464
TI - An abdominal mass in an eleven-year old boy.
PMID- 10786465
TI - Emerging drug resistant Mycobacterium tuberculosis in the Caribbean.
PMID- 10786466
TI - Research-based practice: reducing bedrest following cardiac catheterization.
AB - Patient discomfort with prolonged bedrest following femoral arterial puncture for
cardiac catheterization is a significant nursing problem. Safely reducing the
time required for supine bedrest could improve patient comfort and reduce nursing
care needs. Reducing bedrest also has the potential to improve organizational
resource utilization. A review of the literature was conducted and a decision was
made to implement 2 hours of bedrest, a significant decrease from the previous
practice of 6 hours. Vascular complications were closely monitored in the first
50 patients, as a means of implementing the research-based change in practice. No
significant vascular complications occurred and the practice change has expanded
to all inpatient and outpatient areas caring for patients undergoing cardiac
catheterization. This experience with utilizing research to change practice has
created a positive environment for future research-based initiatives.
PMID- 10786468
TI - The International Normalized Ratio (INR): a review.
PMID- 10786467
TI - Evaluation of 3-hour ambulation post cardiac catheterization.
AB - There is much variation in the length of immobilization for patients post cardiac
catheterization. While it is generally agreed that a period of time on bedrest is
necessary to prevent post procedural complications, the optimal duration remains
unknown. The purpose of this study was to evaluate the effects of 3-hour
ambulation post cardiac catheterization with a 7 french (F) arterial catheter on
bleeding, hematoma formation, and vascular complications. Retrospective chart
data were gathered for a period of 8 months for patients who were on the
traditional 5-hour ambulation protocol, and prospective data were gathered for a
period of 7 months for patients who received the 3-hour protocol. A total of 880
patients were included in the study, with 472 in the 5-hour ambulation group and
408 in the 3-hour ambulation group. The overall incidence of delayed bleeding and
hematoma formation for the 15 month study period was 19.1%, with no occurrence of
vascular complications in either group. Patients who received the 3-hour
ambulation protocol experienced a significantly lower rate of bleeding and
hematoma formation (13%) than patients who received the 5-hour ambulation
protocol (24.4%) (p < 0.001). Ambulating patients 3 hours post cardiac
catheterization with a 7F catheter was found to be safe, and thus has the
potential to decrease hospital length of stay, as well as increase patient
comfort.
PMID- 10786469
TI - The Canadian Institutes of Health Research: what will they bring to
cardiovascular nursing research?
PMID- 10786470
TI - Receiving feedback from reviewers: how to make the most of criticism.
PMID- 10786471
TI - Important issues in clinical practice: perspectives of oncology nurses.
AB - As the 1990's draw to a close, the cancer care environment is undergoing rapid
change. Many issues exist within the complex environment of cancer care that
could create a challenge in providing quality nursing care to patients. This
study examined the current challenges oncology nurses face in their daily
practice. Surveys were mailed to members of the Canadian Association of Nurses in
Oncology asking them to indicate on a list of 80 issues which were problems in
their daily practice. From the responses of 249 oncology nurses, the following
items were ranked as the top 10 problems: anxiety, coping/stress management,
bereavement/death, fatigue, metastatic disease, comfort, pain control and
management, quality of life, recurrence of primary cancer, and nurse burn-out.
Principal component analysis was conducted to determine if patterns existed in
the way problems had been rated. Five components explained 42% of the variance in
the data set: comprehensive cancer care, communication, experience of loss,
terminal illness, and signs and symptoms. Implications for nursing practice,
education and research are highlighted.
PMID- 10786472
TI - Description of the caregiver's educational needs and the degree of her
dissatisfaction.
AB - This study emphasized the learning needs of caregivers whose husbands have cancer
and describes their level of dissatisfaction concerning these needs. A
convenience sample of 30 women caregivers was used. The results demonstrate that
caregivers possess initial acquired knowledge as learners and have 26 specific
learning needs. The existence of a learning need produces a level of
dissatisfaction among the female caregivers. Among these learning needs, the most
likely to generate the greatest dissatisfaction are the learning needs associated
with personal concerns. The results encourage nurses to play a more active role
in learning by assessing whether the information the caregivers are receiving is
understood well enough to meet their learning needs.
PMID- 10786473
TI - Ovarian cancer treatment: the benefit of patient telephone follow-up post
chemotherapy.
AB - Approximately 2,500 women in Canada were diagnosed with cancer of the ovary in
1997 (NCIC, 1997). Standard therapy consists of surgical tumour debulking and
cytotoxic chemotherapy. Very little data are available examining the most
appropriate outpatient management of patients receiving chemotherapy. The
objective of this study was to assess the impact of and benefit received from
telephone follow-up between chemotherapy treatments for patients with cancer of
the ovary. Patients with cancer of the ovary were treated every three to four
weeks with a cisplatin-based chemotherapy. Telephone follow-up was performed five
to seven days post-treatment by the gynaecology oncology liaison nurse. Follow-up
addressed issues pertinent to treatment and disease side effects. A patient
survey addressing the impact of telephone follow-up was performed on a sample of
the patient population. Thirty-one patients responded to the survey: Eighty-seven
per cent found that receiving a call post-chemotherapy was reassuring and
helpful. Eighty-three per cent stated that medications could be adjusted
according to the severity of side effects. Eighty per cent of patients agreed
that most issues had been dealt with at the time of telephone follow-up. Sixty
four per cent felt that their concerns had been addressed during the phone calls,
and only 22% had suggestions on how to improve follow-up. Telephone follow-up
during chemotherapy was a valuable tool in assessing patient needs, side effects,
and concerns experienced during treatments. Telephone follow-up may facilitate
early identification of patient problems allowing appropriate and timely
intervention.
PMID- 10786474
TI - Chemotherapy audit--a confidence builder.
PMID- 10786475
TI - Supportive Care in Oncology: Partnerships in Education (SCOPE)--a pilot program
offered by the London Regional Cancer Centre.
PMID- 10786476
TI - Implantable loop monitor for detection of syncope.
AB - A precise correlation of patient symptoms and rhythm disturbances is a formidable
task, especially when the rhythm disturbances are infrequent and unexpected. An
ILR device that can record events over a longer period of time may be the most
effective way of making a diagnosis and of ultimately determining an appropriate
treatment plan. The Reveal ILR can establish patient symptom/rhythm correlation
during a spontaneous event, leading to a diagnosis of the underlying condition.
Additionally, the device may reduce the need for repetitive low-yielding testing
and decrease the time and costs associated with the diagnosis of unexplained
recurrent syncope.
PMID- 10786477
TI - The evolution of internal defibrillators.
AB - ICDs have reduced mortality from SCD to 2% per year, which is a record unmatched
by any other form of therapy. With continued evolution, ICD systems should become
easier to implant, smaller, more effective in managing a variety of abnormal
rhythms, and more comfortable for the patient. Implementation of technological
innovations in future-generation devices should continue to extend the frontiers
as clinicians consider ICDs for an expanding range of therapeutic applications.
PMID- 10786478
TI - Highlights from the past decade of interventional device research.
AB - The last decade of research and implementation in the interventional device arena
has brought about an unprecedented improvement in the ability to safely and
effectively treat coronary artery disease. This explosion of technology is not
over; there remain questions to be answered and patient subsets whose care can be
improved upon. Our understanding of the restenosis process has helped guide
research in the appropriate directions, and by 2010 restenosis after a coronary
intervention will most likely be of historic interest only. With the addition of
thrombus removal catheters and protection devices, treatment of problematic high
risk lesions will also be improved upon. The effect of these devices on acute
patient care and long-term outcomes, including quality of life, will be profound.
PMID- 10786479
TI - Percutaneous transluminal myocardial revascularization. A new treatment for
angina.
AB - PTMR is a new and exciting alternative treatment for patients with class III or
IV angina who have been treated unsuccessfully with conventional medical
treatments and who have no other treatment options available. It is hoped that
PTMR can decrease or completely relieve these patients' symptoms and improve
their quality of life. Early results with PTMR appear promising, but further
investigation and long-term assessment of patients who have been participants in
PTMR studies need to be undertaken.
PMID- 10786480
TI - Brachytherapy. Savior or tease.
AB - Dating from the inception of percutaneous coronary angioplasty, restenosis has
been the postprocedural Achilles heel. Despite a decade of research, with a
myriad of mechanical devices and pharmacologic agents, this vexing problem has
yet to be resolved. Although intracoronary stents have proved effective at
restenosis reduction, they have yet to achieve an acceptable level and, in some
cases, remain resistant to any treatment. Intracoronary radiation using gamma or
beta isotopes, has generated tremendous excitement with promising results.
Indeed, the SCRIPPS (Scripps Coronary Radiation to Inhibit Proliferation Post
Stenting) trial, which employed gamma radiation, showed a statistically
significant reduction in restenosis in a small patient population. Further
studies with a variety of isotopes and delivery modalities are currently
underway, bringing with them their own assemblage of issues.
PMID- 10786481
TI - Gene therapy for the treatment of cardiovascular disease.
AB - Although still experimental at the present time, gene therapy for the treatment
of cardiovascular disease is on the horizon. Numerous clinical trials in patients
with flow-limiting coronary artery disease are in progress. In order to keep up
with advances in gene therapy, critical care nurses must develop a background in
this discipline. This challenge rests in the hands of nursing educators to
incorporate a sufficient amount of genetic content into the curriculum. Genetics
in the curriculum is essential because it is the central science of health care.
Genetic discoveries are changing our understanding of the mechanisms of disease
and the diagnosis, treatment, and prevention of cardiovascular disease in
particular. Gene therapy is likely to influence our daily nursing practice, and
nurses must have an adequate knowledge of genetics to provide accurate
information to patients and families so that they can make informed decisions
about their health care.
PMID- 10786482
TI - New adjunctive therapy for ischemic syndromes.
AB - Because anticoagulant and GP IIb/IIIa inhibitors reduce mortality, myocardial
ischemia, AMI, and reintervention, these agents are now becoming the standard of
care for patients with USA and NQWMI. Unanswered questions remain about the best
treatment regimen, appropriate dosing, long-term benefit, and cost-effectiveness
of these agents, however, and many additional trials are ongoing or planned. As
nurses administer these drugs, assess the patients' responses to therapy, and
educate patients and families about these agents, they contribute to recent
advances in preventing ischemic heart disease.
PMID- 10786483
TI - Ventricular arrhythmias, electrophysiologic studies, and devices
AB - Because of the high incidence of heart disease in the elderly, ventricular
tachyarrhythmias are not infrequent. Determining the nature and extent of the
underlying heart disease and identifying precipitating causes is required prior
to instituting long-term therapy. Recent studies suggest that for hemodynamically
unstable ventricular tachyarrhythmias, mortality is lower with the implantable
cardioverter-defibrillator compared with pharmacologic therapy. This benefit is
likely to be more modest in the elderly because of competing cardiac and
noncardiac causes of death. For similar reasons, the favorable results reported
with the prophylactic use of the implantable cardioverter-defibrillator are
likely to be attenuated in the elderly.
PMID- 10786484
TI - MR coronary angiography
AB - Coronary MR angiography is a new noninvasive diagnostic method in rapid
evolution. It has the potential to combine structural information with functional
assessment of coronary blood flow. Advances in technology will undoubtedly lead
to enhanced resolution, improved accuracy, and shorter scan times. It is certain
that coronary MR angiography will be a prominent diagnostic clinical tool in the
years to come.
PMID- 10786485
TI - Provision of counselling for the dying patient.
AB - The majority of doctors and nurses clearly recognise their responsibility to
provide palliative care to the dying patient, and also the need for effective
communication, counselling and support for this group of patients. This paper
explores some of the issues preventing patient and significant others from being
referred to the counselling service at this stage, and demonstrates that the
nursing staff feel both inadequate and ill prepared to deliver quality care to
the dying patient and use avoidance as a coping mechanism.
PMID- 10786486
TI - Self perception affecting adherence to drug regimen following renal
transplantation.
AB - The patient, a chronic cannabis user, found it increasingly difficult to tolerate
the side effects of the medication on her appearance. Rejection in the early post
transplant period meant that immunosuppression could not be further reduced. We
were able to avoid a catastrophic self-initiated cut in immunosuppression, and
withdrawal of steroids was carried out according to a schedule supervised by the
clinic. Cellular rejection resulted and was treated with i.v. methyl prednisolone
and conversion from cyclosporin micro-emulsion (Neoral, Novartis) to tacrolimus
(Prograf, Fujisawa) and from azathioprine to mycophenolate mofetil (CellCept,
Roche).
PMID- 10786487
TI - Adherence to treatment and personality in renal failure.
AB - Adherence of individual treatment and personality dimension of locus of control
was analysed. Evidence suggests that locus of control and other personality
dimensions can influence adherence behaviour to treatment. The aim of this study
was to examine the impact of social-clinical factors over personality dimensions
and to provide empirical evidence of the relationship between internal locus of
control experience and higher level of the compliance to treatment and diet. The
results have shown the low level of adherence of patients to treatment and we
found a tendency to correlate the dimension locus of internal control with
adherence to treatment.
PMID- 10786488
TI - The dark side of the moon: how clients face dialysis.
AB - Patients requiring haemodialysis experience various problems, some of which are
caused by the medical treatment. We explored various aspects of a haemodialysis
patients life, to focus on the effects that their treatment had on their daily
life. The aim of this study was "to know the life of the respondent, in order to
improve the quality of the assistance." This pilot study allowed the staff to
plan arrangements in order that the patient could pursue a "normal life".
PMID- 10786489
TI - The psychosocial implications of live-related kidney donation.
AB - The aim of the study was to explore the donor's experience of the live related
transplantation process whilst seeking to identify the external and internal
resources and ethical considerations which were reflected in the decision-making
process. The outcome would indicate that altruism and a sense of moral obligation
were the prime motivational influences with the spontaneity of decision-making
casting doubt on the ability to give informed consent. These findings are also
discussed in relation to implications for professional practice and would suggest
that potential donors benefit from having access to a counsellor during the donor
search and throughout the transplant work up programme.
PMID- 10786490
TI - Assessment of problems: which study design?
AB - Evidence-based medicine has gained recognition in recent years, necessitating a
large amount of conclusive results derived from a large number of experimental
and epidemiological studies. Renal nurses are preferable investigators in this
field because of their close relationship with the renal patient. Apart from
clinical studies, with an experimental study design varying a single factor
between two groups of patients, epidemiological studies are needed to assess
actual problems. Epidemiological studies are purely based on observation, without
altering any factor. The choice of study design will depend on the available
knowledge about the problem and available resources.
PMID- 10786491
TI - Comparative evaluation of CAPD and PD-plus effectiveness.
AB - Decline in residual renal function in CAPD patients often leads to reduced
overall solute clearances. Inadequate dialysis has been linked to malnutrition
and increased morbidity and mortality rates. Achieving dialysis adequacy targets
is often difficult by the conventional method of increasing CAPD exchange
volumes. In comparison, substantial increases in solute clearances can be
achieved with the use of automated peritoneal dialysis with large fill volumes
and an extra daytime exchange.
PMID- 10786492
TI - Stay.safe. A new PVC free system in long-term CAPD treatment.
AB - Stay.safe is a new PVC free double bag PD system that was introduced two years
ago for CAPD. The system has been evaluated by three target groups, patients,
nurses and physicians in 2 different studies. In the pilot study stay.safe was
compared to the previous system and in the multi centre study, new patients
judged stay.safe over a longer period of time. The pilot study showed better
handling and function judgement by experienced patients of the new system
compared to previous. In the multi centre study the overall satisfaction with the
new system including use with disabled patients was very good and this high
valuation was maintained over time.
PMID- 10786493
TI - Increasing the safety of volumetric ultrafiltration control.
AB - Deviations in ultrafiltration volume can cause various problems for patients
undergoing a haemodialysis treatment. With the introduction of high flux
dialysers, closed systems with volumetric fluid balancing became the systems of
choice, because control of transmembrane pressure used previously is too
inaccurate and unsafe to be used with such filters. In this article, a reliable
and cost effective test method is described to increase the safety of a closed
system. The test is carried out by simply analysing the dialysate pressure while
the dialyser is isolated from the system for typically 7.2 seconds. No additional
sensors and components other then a valve combination used to isolate the
dialyser are required.
PMID- 10786494
TI - Results of a national epidemiological investigation of HCV infection in dialysis
patients.
AB - The Italian Branch of EDTNA/ERCA organised a national, epidemiological,
retrospective study to collect data and implement preventative measures for the
spread of HCV infection in dialysis units. A questionnaire was sent to staff in
830 dialysis centres to collect information relating to 1996. Data are presented
on incidence/prevalence of HCV infection, antibodies, viraemia and mortality, and
comparison of the management of HCV between centres. At variance with the
recommendations of the Official Health Organisations, dedicated machines and
separate rooms are used in many centres and this paper concludes with
recommendations for units, in particular those units with a low prevalence of
anti HCV positive patients.
PMID- 10786495
TI - Haemodialysis in acute renal failure.
AB - Haemodialysis in acute renal failure differs from chronic uraemia. We describe
our clinical experience comparing tolerance to dialysis and dialysis efficacy of
bicarbonate haemodialysis in comparison to haemofiltration. Both provide adequate
treatment for ARF, Kt/v 0.6 +/- 0.1, URR 56% in bicarbonate haemodialysis
compared to Kt/v 0.4 +/- 0.06, URR 60% in haemofiltration. Clinical outcome was
the same in both groups, in particular the overall survival was satisfactory at
about 70%. These results are likely to reflect close control of these patients by
nursing staff committed to haemodialysis in acute renal failure.
PMID- 10786496
TI - Renal nursing education: an innovative difference.
AB - The purpose of this paper is to describe the Master of Nursing (Renal) course
that is offered to internal and distance education nephrology nurses in
Australia. The challenging demand of offering this innovative curriculum will be
discussed, and analysis of the first cohort of students will be made. Finally,
future directions for renal nursing education will be discussed.
PMID- 10786497
TI - Buyer's guide and pharmaceutical reference.
PMID- 10786498
TI - Midwives act. Important changes secured by the OIIQ.
PMID- 10786499
TI - [Baby Friendly Hospital initiative].
PMID- 10786500
TI - [Spirituality and nursing care].
PMID- 10786502
TI - Values and critical care--back to basics.
PMID- 10786501
TI - [Therapeutic touch].
AB - In the advanced stages of dementia of the Alzheimer's type (DAT), affected
persons present body language and various behaviours expressing discomfort:
shouting, agitation, irritability, aggressiveness, tense movements. Nursing, up
until now, has had few available means to ease this discomfort. The authors of
the following article have conducted an experimental study measuring the
alleviating effects of therapeutic touch on the discomfort of persons in the
advanced stages of DAT. Experimental group subjects (n = 16) received 5 sessions
of therapeutic touch lasting 12.4 minutes. Control group subjects (n = 11)
received 5 sessions of simple presence lasting 10.3 minutes. The authors measured
subject discomfort levels using the Discomfort Scale for Dementias of the
Alzheimer's Type (DS-DAT). Results show that discomfort levels of persons in the
advanced stages of DAT decreased significantly after 5 therapeutic touch
sessions, becoming significantly lower than levels in the control group. If care
was focused on the whole person and his or her comfort, tools like therapeutic
touch would become available to nurses, allowing them to enhance the quality of
life of the people in their care.
PMID- 10786503
TI - Patients' and relatives' opinions and feelings about diaries kept by nurses in an
intensive care unit: pilot study.
AB - The underlying aim of this study was to obtain knowledge about the questions
which could be of interest for a qualitative interview study, and for the
planning and construction of a comparative study. The immediate aim was, however,
to investigate whether the diary was of importance to patients after their
discharge from the ICU or for relatives, following patients' deaths in the ICU. A
diary was kept for nine months concerning ten patients together with eight
patients who later died in the ICU. All of the ten patients, and four of the
eight deceased patients' relatives, answered a questionnaire consisting of five
close-ended and two open-ended questions. The participants were encouraged to
comment upon all the questions. All participants read the diary. Seven patients
stated that it helped them to remember their ICU stay and two that it did not. It
helped them to re-live and come to terms with their serious illness/injury and
recall what had happened. For those who could not recollect their ICU stay, the
diary helped them to remember 'the lost time'. All the relatives except one
stated that it helped them to return and adjust to everyday life; made it easier
to accept what had happened; and to understand the seriousness of the patient's
injury or disease.
PMID- 10786504
TI - Use of the prone position in the management of acute respiratory distress
syndrome.
AB - The positioning of patients is usually within the domain of nursing practice,
whether this is to achieve increased comfort or as a therapeutic intervention to
avoid the occurrence of pressure sores. The use of the prone position to improve
oxygenation, in the acute respiratory distress syndrome, has become increasingly
popular in intensive care over the past decade (Thomas 1997). A systematic review
was, therefore, undertaken to ascertain if the prone position did, in fact,
improve oxygenation, leading to decreased mortality, or if the effects were
merely transitory. Review findings indicate that use of the prone position does
improve oxygenation, as measured by PaO2/FiO2 indices, and appears to reduce
mortality. However, caution should be taken in applying these results to
practice. First, the studies available for review demonstrated various
methodological flaws. It is also apparent that untoward incidences associated
with the prone position have yet to be investigated systematically.
PMID- 10786505
TI - Critical analysis of access to and availability of intensive care.
AB - In intensive care, there appears to be an ever-increasing demand for resources
and it is widely recognized that there is often a shortage of vacant beds
available, compounded by an inadequate level of appropriately qualified nursing
staff. Either of these deficiencies may lead to delayed or even refused admission
for a patient who is critically ill. This review of the literature contains
examination of the access and availability of intensive care facilities within
the National Health Service and discussion of the problems that arise in gaining
admission to such facilities. Being refused admission to the local intensive care
unit may have important implications for a critically ill patient, resulting in
transfer to another hospital, perhaps many miles away, or inadequate treatment
and care in a general ward. These issues are also examined and strategies for
action are proposed.
PMID- 10786506
TI - Clinical governance and intensive care: what does it mean?
PMID- 10786507
TI - Effects on oxygen saturation levels of handling premature infants within the
concepts of kinaesthetic infant handling: pilot study.
AB - Preterm infants are exposed to many stressors within the neonatal intensive care
environment. Since these are associated with medical and developmental problems,
a reduction of stress factors is desirable. Handling is a very common occurrence
and is associated with stress. Kinaesthetic infant handling (KIH) offers
practical guidance on handling for nurses and has been widely implemented in
Germany, although there is no direct experimental evidence to support its use.
The findings of this pilot study suggest a beneficial effect on the SpO2 for
infants who were handled using KIH. Since this was a pilot study with a small
sample size, caution has to be exercised with this finding. Therefore, the main
purpose of the study was: (1) to identify the weaknesses and strengths of the
chosen study design; and (2) to perform a power analysis in order to determine a
sufficient sample size for the full experiment.
PMID- 10786508
TI - Respiratory assessment in critical care units.
AB - As healthcare delivery changes in critical care, nursing continues to extend its
practice base. Nursing practice is expanding to incorporate skills once seen as
the remit of the medical profession. Critical care nurses are equipping
themselves with evidence-based knowledge and skills that can enhance the care
they provide to their patients. Assessment of patients is a major role in nursing
and, by expanding assessment techniques, nurses can ensure patients receive the
care most appropriate to their needs. Nurses in critical care are well placed to
perform a more detailed assessment which can help to focus nursing care. This
article describes the step-by-step process of undertaking a full and
comprehensive respiratory assessment in critical care settings. It identifies
many of the problems that patients may have and the signs and symptoms that a
nurse may not whilst undertaking the assessment and preparing to prescribe care.
PMID- 10786509
TI - Costing of consumables: use in an intensive care unit.
AB - In 1991, the Intensive Care Unit (ICU) at Middlemore Hospital manually costed the
treatment and care of asthmatic patients. This was long-winded and labour
intensive, but provided hard data to support anecdotal beliefs that intensive
care patients are more expensive than was currently believed or accepted. It is a
known problem that funder and provider organizations see a huge disparity on the
funding issue. With additional accurate information on the actual cost of
individual patients, which can be grouped into disease categories, funding
applications can be backed with accurate, up-to-date quantitative data. After a
long preparation time, we are now costing individual patient stays in the ICU.
Each individual resource was established, costed and entered into an MS ACCESS
computerized database. Schedules have been prepared for updating prices, as these
change. The final report available gives a detailed list of resource use within
certain categories. Some items proved to be impractical to cost on an individual
patient basis, and these have been grouped together, costed, and divided by the
number of patient days for the last year, and assigned to each individual patient
as an hourly unit cost. Believed to be a world-first, this information now forms
the basis for variance reporting and pricing.
PMID- 10786510
TI - New antibiotics for gram positive infections: linezolid and combination
quinapristin/dalfopristin.
AB - Considerable research over the past decade has thrown up two novel antibiotic
preparations which are effective in 'difficult' Gram positive infections. Their
imminent arrival is welcomed at a time when the emergence of resistance to last
line drugs is rapidly spreading. Their careful use is, however, crucial if long
term value is to be preserved.
PMID- 10786511
TI - Chest X-ray quiz. A pericardial effusion.
PMID- 10786512
TI - Philosophy of integrity or integrity of philosophy?
PMID- 10786513
TI - Measuring the compliance behavior of adolescents wearing orthopedic braces.
AB - This paper reports the observed difference between two measures of compliance in
wearing an orthopedic brace among teenagers affected by idiopathic scoliosis. The
first measure was obtained with a small device called a "compli-o-meter" that was
developed specifically for this purpose. When fastened to an orthopedic brace,
this instrument determines the brace's actual wearing time. The second compliance
measure was derived from a questionnaire-interview administered to the
participants. The subjects were 40 female teenagers aged between 10 and 16 years
who had been wearing an orthopedic brace for 18 months or less. While the
compliance rate reported by the participants averaged 88%, the actual rate
measured by the compli-o-meter was only 33%. Pearson's correlation was r = .33,
with a significance of p < .05 between these two measurements. Care should be
exerted in assessing the therapeutic efficiency of an orthopedic brace based
exclusively on a patient's reported compliance level. In particular, basing a
recommendation to change the brace based solely on this information may result in
erroneous and serious therapeutic actions. The efficiency of orthopedic braces
should be assessed on objective measures of the actual compliance rate wherever
possible.
PMID- 10786514
TI - Self-esteem changes in children enrolled in weight management programs.
AB - The purpose of this study was to examine self-esteem changes in school aged
children enrolled in weight management programs. The study group was comprised of
54 obese children ages 10-15 enrolled in a weight management program. The control
group was comprised of 60 obese children who had never been enrolled in a weight
management program. Each child was measured for body mass index (BMI) and weight.
All the children filled out the Pier-Harris Children's Self-Concept Scale at the
beginning of the study and 12 weeks later following the study group's completion
of the weight management program. The groups were similar in average age, weight,
BMI, and self-concept score at the beginning of the study. At the end of the 12
weeks, there was no significant change in the average weight or BMI in either the
study or control group. There was a significant decrease in the self-concept
score in the study group but not in the control group. The greatest score changes
came from the physical appearance subscale. Participation in weight management
programs may put children at risk for lower self-esteem (self-concept) while
producing limited weight loss results.
PMID- 10786515
TI - "Good little girls": reports of pregnant adolescents and those who know them
best.
AB - A qualitative descriptive study was conducted to identify characteristics and
themes in the lives of pregnant adolescents. Eight pregnant adolescents between
the ages of 16 and 18 years of age were recruited from a large public prenatal
clinic. Half the adolescents were African-American and half were European
American. Fully 75% lived in middle-income families and 25% in lower income
families. At the time of participation in the study, 75% remained in high school
and 25% had dropped out. The girls identified their mothers as "the person who
knows me best." The eight dyads participated in individual interviews. The
adolescents' views of themselves, of their characteristics and behavior, and
their mothers' perceptions of the adolescents' characteristics and behaviors were
elicited. Home observation notes and demographic data also were collected. The
template method of content analysis and a codebook from two preliminary pilot
studies were used to analyze the interview data. Findings included reports that
these pregnant adolescents had adult responsibilities at an early age, which
frequently included child care of younger siblings. The families viewed the girls
as mature and obedient, and the mothers did not think the adolescents were
sexually active prior to the pregnancy. It is significant that these teenagers
were frequently reported to be "good little girls," and others did not view them
as at-risk. The findings from this study can be used for early identification of
adolescents at risk for becoming pregnant and to develop specific preventive
measures.
PMID- 10786516
TI - The measurement of child characteristics from infancy to toddlerhood:
temperament, developmental competence, self-concept, and social competence.
AB - Maternal report on four characteristics was obtained for 126 infants at 8, 12,
24, and 36 months of age. Temperament was assessed using the Revised Infant and
Toddler Temperament Scales; the Infant/Child Monitoring Questionnaires were used
to screen developmental competence. The Self-Concept Questionnaire and the
Adaptive Social Behavior Inventory were outcome measures at 12, 24, and 36
months. Temperament and developmental competence were found to be relatively
stable but unrelated over time. The second year, 12-24 months, was a salient
period of development in which the greatest increases in self-concept and social
competence were observed. Correlation analyses revealed temperament difficulty
was negatively related to social competence yet unrelated to self-concept;
developmental competence was more strongly related to the developing self-concept
than social competence. The strongest relationships between social competence and
self-concept were obtained by earlier social competence in relation to subsequent
self-concept.
PMID- 10786518
TI - Book reviews--keeping up to date in the era of the information super highway.
PMID- 10786517
TI - Early adolescents' sexual behaviors.
AB - The purpose of this study was to analyze changes in early adolescents' intimate
behaviors and the initiation of sexual intercourse over a one-year time period.
The changes are interpreted within the context of recent progress in
understanding the development of early adolescents. Public school students in
sixth and ninth grades of selected schools in a midwestern industrial city were
studied in two waves of data collection. A total of 106 students provided data
for the second year, allowing comparisons of their Time 2 with their Time 1
responses. Five of eight intimate behaviors studied increased in frequency during
the year. Also, the adolescents' perceived benefits of having sexual intercourse
increased and perceived costs decreased during the follow-up year. Increases in
the frequency of intimate behaviors but not changes in their perceptions of the
benefits and costs predicted whether or not students had initiated sexual
intercourse during the follow-up period. These findings support current
understanding of early adolescence as a time of incremental learning about
intimacy and about sexual relationships. The findings suggest that preventing
early sexual intercourse may require understanding the specific behavioral
competencies related to healthful development of intimacy. Pediatric nurses can
be leaders in providing the necessary counseling and education to young
adolescents, their families, and their communities.
PMID- 10786519
TI - Nurses' perceptions of caring as documented in theory and research.
AB - Caring represents an essential human need and the fundamental component of the
nursing profession. A deep understanding of caring and the way it is expressed
will help nurses to provide high-quality services and, more importantly, to
understand nursing itself. This review of the literature indicates the importance
of examining caring both conceptually and operationally. Based on theoretical and
research accounts, it also presents the wide variety of ways in which caring is
conceived and expressed within the professional field. Caring is examined from
anthropological, philosophical and psychosocial perspectives. In this paper
implications for practice and research are outlined.
PMID- 10786521
TI - Core competencies for clinical nurse specialists: a usable framework.
AB - This article describes a framework of generic core competencies for assessing the
role of the Clinical Nurse Specialist (CNS). It was devised by a group of CNSs at
Kingston Hospital NHS Trust, over a two year period. Currently, there is
considerable confusion surrounding the role of the CNS. The UKCC is in the
process of clarifying what is meant by specialist practice, with the aim of
formally recognizing its status on the register. There does not seem to be a
consensus opinion on the standards of competence required to practise as a CNS.
This article seeks to address this issue by demonstrating a means of competency
based assessment for the role of the CNS.
PMID- 10786520
TI - Factors contributing to medication errors: a literature review.
AB - Drug administration is an integral part of the nurse's role. Responsibility for
correct administration of medication rests with the nurse, yet medication errors
are a persistent problem associated with nursing practice. This review examines
what constitutes a medication error and documents contributory factors in
medication errors. These factors have been derived from reported medication
errors and opinions of nurses as to factors which predispose to errors. A number
of definitions exist as to what constitutes a medication error. The definition
used should facilitate interpretation and comparison of a wide range of research
reports. Medication errors are a multidisciplinary problem and a
multidisciplinary approach is required in order to reduce the incidence of
errors.
PMID- 10786522
TI - Nurse specialists' perceptions of their role and function in relation to starting
an adult diabetic on insulin.
AB - The purpose of this study was to describe how diabetes nurse specialists
perceived their role and function in relation to starting adult patients with
insulin dependent diabetes on insulin. Using Heideggerian hermeneutic
phenomenology as a research method, six diabetes nurse specialists were
interviewed and the interviews were analysed according to Colaizzi's method of
phenomenological inquiry. Results showed that the diabetes nurses perceived their
role to be composed of six themes: educator; promoter of physical skill
acquisition; psychological supporter; advocate of individualized care; promoter
of self-care; 'safeguard' in assessing and ensuring patient safety. These results
support findings from other studies, that the diabetes nurse specialist role
seems to be more complex than descriptions in the nursing literature offer.
PMID- 10786523
TI - The success of an integrated care programme for patients with ischaemic heart
disease: the practice nurses' perspective of SHIP.
AB - Follow-up care of patients with angina and myocardial infarction after hospital
discharge is known to be suboptimal across the UK. The employment of cardiac
liaison nurses ensured timely notification of hospital discharge and good
communication of each patient's current and planned care. The direct ongoing
support of the liaison nurse was valued by more practice nurses than educational
support meetings and the initial counselling skills course. The most important
factor which enabled practice nurses to expand their role to provide post
hospital follow-up care was the support of the doctors in the practice. After the
conclusion of the Southampton Heart Integrated Care Project (SHIP) and the
withdrawal of cardiac liaison nurses, the lack of hospital discharge notification
was the most important reason for practice nurses discontinuing follow-up care.
PMID- 10786524
TI - Identifying approaches to meet assessed needs in health visiting.
AB - An action research project, based in a single fundholding practice on the south
coast of England, aimed to identify the health needs of families with resident
children, then use the contracting system to redirect health visiting services to
meet those needs. After assessing the health needs, it was necessary to assess
the potential of a range of health visiting approaches that might be proposed to
meet those needs. This paper explains how the approaches were assessed for use in
the local area and why funding for two additional, innovative posts was deemed
necessary. Despite the unsophisticated evidence base for health visiting
interventions, a case can be made for commissioning particular service approaches
by using a combination of survey data and results from controlled and
uncontrolled service evaluations. The supportive focus of health visitor home
visiting remains an appropriate use of existing resources, but the usual
intensity of visiting may be insufficient for full effectiveness. To rationalize
such services by targeting them only at individuals with established needs risks
an exacerbation of deteriorating health trends across an area. Alternatively,
augmenting home visiting with a community development approach to improve the
adverse social environments in which families live may help to change the
underlying factors that contribute to ill-health and prove more widely cost
effective.
PMID- 10786525
TI - An exploration of the stroke co-ordinator role.
AB - Although there is knowledge of the substantial benefits of collaborative
approaches to stroke rehabilitation, information on alternative management
strategies is sparse. This paper describes an exploratory survey, undertaken in
the north-west of England, to highlight features of the stroke co-ordinator role.
The role is explored in terms of rehabilitation management and service
development. Some strategies to support practitioners in the role, and areas for
role development, are suggested.
PMID- 10786526
TI - 'Going to the bathroom four or five times a night ...': seven men talk about
their experiences of benign prostatic hyperplasia and the perioperative period.
AB - This study describes ageing men's experiences of benign prostatic hyperplasia and
transurethral resection. The experiences of ageing men participating in this
study vary in different periods of their treatment. It is evident that
experiences are attached to feelings, cognitive thinking and responses.
PMID- 10786527
TI - Identifying strategies for managing urinary incontinence with women who have
multiple sclerosis.
AB - The aim of this pilot project was to identify strategies for managing
incontinence with women who have multiple sclerosis (MS). The project used the
formation of a group in which eight women with MS and four Continence Nurse
Advisers (CNAs) and the first author were brought together. In the course of the
research process, the women found a voice on a topic previously thought of as
taboo. When they realized that they had suffered alone and in silence they felt
empowered to act. In this way, the methodology evolved from group work into a
participatory action research process (PAR), as the group initiated action.
Participants formed a self-help group, and continued to meet with each other
after the research had run its course.
PMID- 10786528
TI - Studying the careers of nurse diplomates: the importance of branch-specific
questionnaires.
AB - Questionnaire design is considered in the context of a longitudinal panel study
focusing on the careers of people qualifying from all four branches of the UK
nurse diploma course. Separate, but comparable, questionnaires were developed for
each branch in order to produce information which reflected the differences
between branches, and the experiences of the cohort as a whole. This approach
ensured that participants from the smaller branches did not feel their interests
and concerns were overshadowed by those of the largest (adult) branch, as is
often the case during the diploma course's Common Foundation Programme. The
elements that needed to be tailored to each branch emerged during a three-stage
piloting process used to develop and test the questionnaires. Differences were
found between branches in their use of terminology; in certain issues being more
relevant to some branches than others; and in questions which concerned all
branches benefiting from the inclusion of branch-specific examples. The
effectiveness of this approach to questionnaire design is borne out by the
study's high response rates.
PMID- 10786530
TI - Information point: Colaizzi's framework for analysing qualitative data.
PMID- 10786529
TI - Implementing supernumerary learning in a pre-registration diploma in nursing
programme: an action research study.
AB - The purpose of this study was to develop a framework for implementing
supernumerary learning in a preregistration Diploma in Nursing programme in an
Irish hospital. Experiences of student nurses (n = 31), clinical nursing staff (n
= 8) and nurse teachers (n = 4) were explored, regarding the introduction of
supernumerary status in this programme. An action research approach, employing
phenomenological methods for gathering and analysing the data, was used to carry
out the study. A framework for implementing supernumerary learning in a Diploma
in Nursing programme was developed, based on the study. This framework reflects
the level of knowledge, skills and attitudes of individuals partaking in
supernumerary learning, and the role of the supervisor in the clinical area at
each level. Possible implications of the changing role of the student nurse for
nursing practice for education, management and research are suggested.
PMID- 10786531
TI - Effect of education on evidence-based care and handling of peripheral intravenous
lines.
AB - Deficient routines in use, care, handling and documentation of peripheral
intravenous vein cannulae (PIV) have previously been reported, and complications
have been noted in 50-75% of the patients. The aim of the study was to examine
whether specially trained nurses change their actions to decrease complications
when using cannulae. The study included 36 nurses assigned to experimental and
control groups. The experimental group followed an education programme explaining
how to use and take care of a PIV. To evaluate the intervention document
analysis, observations and patient interviews were performed in 99 patients with
172 PIVs in situ for less than 24 h. After the education programme, fewer
complications, more carefully performed care and handling, and better
documentation and information were found in the experimental group. Nurses in the
control group followed current routines, which resulted in a greater degree of
complications. Education in evidence-based care and handling gives nurses the
opportunity to improve their ability to use theoretical knowledge in clinical
problems.
PMID- 10786532
TI - Strategies for feeling secure influence parents' participation in care.
AB - This study investigates what makes parents of hospitalized children feel secure
and factors influencing their level of participation. It also studies, whether
the degree to which parents participate affects their child's pain and sleep
during hospitalization. Questionnaires were distributed to a series of parents
whose children were discharged from two paediatric surgical wards and one
paediatric medical-surgical ward at two university hospitals in Sweden. Parental
security is almost equally distributed among three given alternatives: security
derived from trusting that professionals know how to take care of the child;
security derived from having control over what is happening to the child; and
security derived from being the one who knows the child best. Depending upon the
strategy chosen, parents want to participate at different levels in their child's
care. The results indicate a relationship between parental participation and
their estimation of their child's pain. The study confirms a pattern, developed
in a previous study, in how parents adopt different strategies affecting their
participation during their child's hospitalization. Some parents who wanted to
participate in more aspects of their child's care seemed to think that their
child had less pain than parents who preferred more limited participation.
PMID- 10786533
TI - Blood transfusion from the recipient's perspective.
AB - This paper reports on an interpretative research study that set out to develop a
rich description of patients' experiences of the process of preparing for and
receiving a blood transfusion. The themes of information-giving and receiving;
reactions, both physical and emotional; and the care and treatment participants
received through the experience are presented.
PMID- 10786535
TI - Parents' experiences of general hospital admission for adults with learning
disabilities.
AB - General hospital care for people with learning disabilities is strongly
emphasized in recent health policy. Ten sets of parents were interviewed about
their experiences of general hospital inpatient care for their adult sons and
daughters with learning disabilities. Findings in the areas of placement,
occupation, basic nursing care, feeding, toileting, nursing attitudes, staffing
and procedures are presented. Recommendations are made for changes to reported
nursing practice to improve the quality of general hospital care for people with
learning disabilities.
PMID- 10786534
TI - Women's experiences of obtaining emergency contraception: a phenomenological
study.
AB - Emergency contraception (EC) has been available since 1984 but has been labelled
the 'best kept secret' (Winfield, 1995). Because EC was originally termed 'the
morning after pill', many people interpreted this literally and missed an
opportunity to use the method. More recent publicity has dropped this term and
emphasized that the method is effective up to 72 h after unprotected intercourse
or contraceptive failure (Burton & Salvage, 1990). Uptake of EC has steadily
increased since 1985 but there is still evidence that younger women in particular
are least aware of its existence.
PMID- 10786536
TI - Palliative care nurses' feelings about death rattle.
PMID- 10786538
TI - Information point: confidence interval.
PMID- 10786537
TI - Perceptions of caring among nurses: the relationship to clinical area.
PMID- 10786539
TI - A social work imperative: recruiting African American males into the profession.
AB - This article outlines why it is important that the social work profession take
affirmative steps toward recruiting African American males into the field. Also
described are the results of a qualitative research project on factors related to
a social work career choice by African American male undergraduate students.
Implications for the profession and African American families are discussed.
PMID- 10786540
TI - Common human needs in the context of diversity: integrating schools of thought.
AB - In this article we argue that effective social work practice which honors
cultural diversity is best informed through an integration of the strengths
associated with modern and postmodern schools of thought. This integration
provides a lens for simultaneously seeing common human needs and individual
differences, a vision that neither school of thought alone can provide. Aspects
of Virginia Satir's growth model are presented as an example of a practice
approach that incorporates this simultaneous attention to similarities and
differences.
PMID- 10786541
TI - Somatization and depression among former Soviet immigrants.
AB - This study investigated the prevalence of pure and overlapping forms of
somatization and depression in a sample of former Soviet immigrants and whether
pure somatization or pure depression could be differentiated using the study
variables. Study respondents completed a demographic questionnaire, the Demands
of Immigration Scale, and the Symptom Checklist 90R. Respondents were classified
as (a) neither depressed nor somatic, (b) only somatic, (c) only depressed, or
(d) both depressed and somatic. Univariate analyses and logistical regression
were used to compare these four groups and to predict the likelihood of being
only depressed or only somatic. The four groups differed in terms of immigration
demands, age, education, employment, and years in the U.S. A logistic regression
analysis was able to classify 75% of the participants as only somatic or only
depressed on the basis of certain demographic characteristics. Age, being
unemployed and not looking for work, and not having a college education increased
the risk of being somatic rather than depressed.
PMID- 10786542
TI - African American women and substance abuse: an overview.
AB - Contemporary trends and forces suggest that drug use and drug abuse among women
may be rooted in a cultural context. Cultural patterns and experiences provide
situations out of which women forge their sense of self, their identity, their
concept of race and ethnicity, their notion of gender, and their sense of class.
A woman's life experience and situation, and cultural roles and beliefs generally
influence drug abuse. This paper builds on the cultural context of drug use by
analyzing the socialization of women, and the life circumstances and socio
demographic experiences women face. Specifically, this cultural context framework
forms the foundation for the prevention of drug abuse and the extent to which
health professionals need to understand drug abuse and to treat women effectively
across class, and racial and ethnic differences.
PMID- 10786543
TI - Preventing premature death: part strategy, part window dressing?
PMID- 10786544
TI - Towards practice development--a vision in reality or a reality without vision?
AB - This paper describes the development of a conceptual framework for practice
development. Drawing on the authors' combined experiences of facilitating
developments in practice, a conceptual framework is proposed. It is argued that
much practice development in health care today lacks a systematic approach and is
often undertaken by individual practitioners who are poorly prepared for their
roles. A short history of practice development is outlined to contextualize
current development activities. The proposed framework is located in a critical
social science philosophy and it is suggested that such a philosophy enables
individual growth and development, empowerment of practitioners and the
generation of cultural change that sustains continuous growth and innovation in
practice. An example of the framework in use is described and recommendations
proposed to enable organizations to embrace a systematic approach to practice
development.
PMID- 10786545
TI - Identifying, evaluating and implementing cost-effective skill mix.
AB - BACKGROUND: The British National Health Service (NHS) employs a large number of
individuals, at great monetary cost, to provide direct care to patients. Changes
in the combinations of staff, including nurses, nurse practitioners and midwives,
delivering this care have been shown to be effective in many settings. FINDINGS:
The (opportunity) cost implications of such changes in the skill mix are rarely
evaluated adequately. The impact of releasing professionals' time has not been
estimated and therefore determining whether changes are cost-effective is
difficult; these difficulties have often been increased by poor study design.
CONCLUSIONS: Economic evaluation has been under-utilized in studies of skill mix.
If economic evaluation demonstrates that skill mix changes reduce cost and
improve or maintain patient outcomes, this is strong evidence that these changes
should be implemented. Incentives may be required to attract the necessary
personnel. This in itself may influence the cost of changing the skill mix and
therefore the situation should be monitored as both costs and effectiveness can
alter over time.
PMID- 10786546
TI - Factors that influence nurses' customer orientation.
AB - BACKGROUND: Hospital care mostly involves complex processes that are continuously
adjusted to match individual client needs. As most patients cannot evaluate the
technology used, they focus on personal interactions with care providers when
making judgements about the care received. Nurses are the care team members that
primarily provide ongoing care. AIMS: This study aims to further understand
factors that influence the way nursing staff relate to their patients. A model is
presented of the contextual and self-perceptual factors that influence the level
of customer/client orientation of nursing services in an Australian hospital
setting along with details of a quantitative study. METHODS: Nurses completed an
anonymous questionnaire, which was then mailed directly to the researchers.
Analysis of the data included factor analysis, regression and path analysis.
FINDINGS: The results show that contextual elements such as management commitment
to service quality and self-perceptual factors such as role stress impact on the
nurses' client service orientation. However, the variables being studied commonly
have both direct and indirect effects with feelings about commitment to the
organization having a notable mediating influence. The scales adapted from use in
other industries are able to measure the perceptual and outcome variables in a
health institutional setting. CONCLUSIONS: The managerial implications are that
both a comprehensive programme of organizational culture and individual staff
member development is needed if an enhanced customer orientation and the
consequent improvement in client satisfaction with nursing care is to occur.
PMID- 10786547
TI - Go the extra mile--use the Delphi Technique.
AB - AIM: The Delphi Technique is reviewed and its potential contribution to the
management of change assessed. BACKGROUND: Change management is an essential
skill required, not just by managers, but by all staff working in health care.
Modern theories advocate participation and free communication to engender
commitment and ensure successful change. Data collection methods associated with
surveys--interviews and questionnaires--are regularly used to obtain information
for service development. Indications of likely resistance are more difficult to
obtain. KEY ISSUES: The Delphi Technique is critiqued and found to incorporate
many attributes that can produce information which would be otherwise difficult
or impossible to obtain. A recently published study performed by the author
illustrates this potentiality. An indication of the impact of the findings on the
subsequent implementation of change by service managers is provided. CONCLUSION:
The Delphi Technique is a useful management tool that can provide data that are
difficult to obtain by other means.
PMID- 10786548
TI - The staff's experience of structural changes in the health and medical service in
western Sweden.
AB - BACKGROUND: The structure and contents of the health and medical service have
changed in recent years. The merger of Norra Alvsborgs and Uddevalla hospitals
into one local district under one leadership (the NU medical service) is a
Swedish example of a structural change. AIMS: This study intends to describe and
analyse the staff's experience of a recently accomplished structural change in
the local district NU medical service in the western part of Sweden. METHODS:
This study has been carried out from a qualitative point of view inspired by
grounded theory. From a theme guide with specific questions, 31 interviews were
carried out with staff working in the NU medical service. FINDINGS: Four
categories emerged from the body of interviews: 'participation', 'doubts',
'anxiety' and 'faith'. 'Participation' was defined as an overall core category,
and was related to the other categories. The categories 'doubts', 'anxiety' and
'faith' were related to sub-categories and affected by the overall category
'participation'. CONCLUSIONS: The overall results point to the importance of
participation of staff members concerned. The role of the leadership when
undergoing structural changes is considered as a major factor to make other staff
members participate.
PMID- 10786549
TI - Conceptions of oral health among nurse managers. A qualitative analysis.
AB - AIM: The aim of this study was to describe how nurse managers perceive oral
health in general and the oral health of the care-receiver in particular.
BACKGROUND: Oral health and general health are independent and influence each
other through biological, psychological, emotional and developmental factors. To
most adults, oral health is a natural daily routine of hygiene, whereas to people
who are dependent on other people's assistance, it is a procedure carried out by
nursing personnel. METHODS: Data were collected through interviews and analysed
according to the phenomenographical method. FINDINGS: Five categories emerged
describing how nurse managers perceive oral health: maintaining patients' well
being, having knowledge about oral health, behaviour towards the patient, feeling
of being insufficient and creating the necessary conditions. CONCLUSION: The
nurses considered oral health an important and obvious, but neglected, part of
nursing. They expressed the wish to be updated in the knowledge area concerned,
both for themselves and for their personnel. A majority called for standards for
oral care, including documentation, which was considered necessary for the
successful implementation. IMPLICATIONS: A suggestion for further research is to
study whether the creation of national standards may increase its status and
quality.
PMID- 10786550
TI - Finding the advocacy in yourself.
PMID- 10786551
TI - Telephone protocol.
PMID- 10786552
TI - HIV postexposure prophylaxis after blood exposure in school.
PMID- 10786553
TI - Case study: family stress and Alzheimer's disease.
PMID- 10786554
TI - Factors associated with nursing diagnosis utilization in Canada.
AB - PURPOSE: To investigate factors associated with nursing diagnosis utilization.
METHODS: A retrospective chart audit was conducted on four hospital units over a
5-month period and linked to the nurses (N = 65) who participated in a survey on
attitudes toward nursing diagnosis. FINDINGS: Computer-generated nursing care
plans resulted in the greatest frequency of nursing diagnosis documentation.
Nurses who did not document nursing diagnoses, and nurses employed in hospitals
without nursing diagnosis implementation programs, had more positive attitudes
toward the value of nursing diagnosis in practice compared with nurses who
documented nursing diagnoses and nurses employed in hospitals with implementation
programs. CONCLUSIONS: Nurses have a greater tendency to document nursing
diagnoses when institutions have formal educational programs and computer
generated care plans.
PMID- 10786555
TI - From risk for trauma to unintentional injury risk: falls--a concept analysis.
Nursing Diagnosis Extension and Classification Research Team.
AB - TOPIC: Concept analysis of the nursing diagnosis risk for trauma. PURPOSE: To
examine the nursing diagnosis risk for trauma and to specify the risk factors for
falling. SOURCES: Research and informational articles on falling, and NANDA
Nursing Diagnoses: Definitions and Classification, 1999-2000. CONCLUSIONS:
Replace the current nursing diagnosis risk for trauma with the more specific
nursing diagnosis unintentional injury risk: falls. The other risks included in
risk for trauma (e.g., burns) also will need to be developed.
PMID- 10786558
TI - Factors affecting quality assurance in nursing care.
PMID- 10786556
TI - Clinical validation of characteristics of the alcoholic family.
AB - PURPOSE: To validate, from a client and family perspective, the defining
characteristics for the nursing diagnosis altered family processes: alcoholism;
and to identify demographic, family, and selected treatment information from
clients and family members. METHODS: Subjects (N = 150) completed Fehring's
(1987) Clinical Diagnostic Validation (CVD) Index for 110 defining
characteristics of the nursing diagnosis altered family processes: alcoholism.
FINDINGS: Alcoholic families display behaviors of alcohol abuse, loss of control
of drinking, denial, nicotine addiction, impaired communication, inappropriate
expression of anger, and enabling behaviors. Family feelings indicate the
presence of unhappiness, hurt, frustration, guilt, moodiness, powerlessness,
loneliness, mistrust, anger, anxiety, and hopelessness. CONCLUSIONS: These
clinically validated characteristics will complete the assessment phase of this
research and direct the path to future studies to determine appropriate
goals/outcomes and interventions related to alcoholic families.
PMID- 10786557
TI - A critical time for nursing diagnosis research.
PMID- 10786559
TI - Inter-sex. Newer concepts, surgical and nursing management.
PMID- 10786561
TI - Prevention of child marriages: a report on awareness in rural Andhra Pradesh.
PMID- 10786560
TI - Relationship between sex roles and mental disorders.
AB - The present study "Relationship between sex roles and mental disorders" analyses
the various findings of research regarding the sex roles and mental problems. All
these findings reveal that the women whether they work outside or not, face
various mental problems especially functional psychosis and neurosis. This
finding is also proved by the research of National Institute of Mental Health
(NIMH) of U.S.A. They analysed the admissions and the treatment give for the
psychologically affected persons in various hospitals and came across more women
patients than the men. The research also formulates some possible suggestions to
curb the mental disorders among the women.
PMID- 10786562
TI - Issues and perspective of nursing in Gujarat.
PMID- 10786563
TI - If you don't do it, it won't happen!
PMID- 10786564
TI - Continuous quality improvement initiatives. A new philosophical approach to
quality assurance?
PMID- 10786565
TI - Continuous quality improvement. Cult or science?
PMID- 10786566
TI - Designing successful learning programs.
AB - This article gives an overview of the opportunities in distance learning for
degree-granting programs in schools of nursing. The focus is on the unparalleled
innovations in technology and the centrality of that technology to nursing
education. One of the important aspects of the use of technology is the
development of sound educational programs and practices. Schools of nursing
embarking on a distance learning model should determine the approach that will be
used and examine critical success factors to ensure a quality program and
economically successful outcome. The promise of interactive communication as a
pedagogical strategy has potential and promise for the future.
PMID- 10786567
TI - Credentialing. A paradox for the 21st century.
AB - As a result of mixed and seemingly contradictory forces in the sociopolitical,
economic, and health care environments, credentialing has taken on new momentum
and direction in the United States and abroad. The nursing profession, including
the American Nurses Credentialing Center, is meeting the challenge through new
approaches and partnership endeavors among nursing organizations and with other
health care providers and consumer groups.
PMID- 10786568
TI - Invisible inventors. A historical overview of creative midwives and nurses.
AB - This historical overview documents women's inventions for providing nursing care
dating from 1608 to 1928. The word invention is broadly defined and includes
ideas that created therapeutic activities, caregiving environments, and specific
devices for care. It focuses on the creative contributions of early outstanding
midwives and other practicing nurses around the late 19th and early 20th
centuries. Sources include illustrations of patented items, practical hints
published in early issues of the American Journal of Nursing (AJN), published
translations of original documents from Europe, original historical research on
women in Europe and America, and records from the U.S. Government Patent Office.
The role of nurses in creating and developing tools and methods for providing
nursing care has gone unrecognized. It is important to clarify the record of
women's and nurses' inventiveness.
PMID- 10786570
TI - Pay review must be fair.
PMID- 10786569
TI - Strategies for successful research project management.
AB - Beginning researchers may not fully appreciate the complexity of implementing a
study, or the degree of rigor and precision involved. Successful project
management requires careful planning, conscientious follow-through, and
continuous monitoring. Several aspects of project implementation are discussed:
defining roles and responsibilities of project personnel, overseeing progress of
the project, planning and managing the budget, and record keeping. Concrete
strategies are provided, with the emphasis being on proactive approaches that
prevent problems rather than on reactive crisis management.
PMID- 10786571
TI - Maybe, just maybe....
PMID- 10786573
TI - Moving on and moving up. Interview by Charlotte Alderman.
PMID- 10786572
TI - Lost continence.
PMID- 10786574
TI - In the driving seat.
PMID- 10786575
TI - Inside out.
PMID- 10786577
TI - There's no place like home.
PMID- 10786576
TI - Something worth saying? Then say it.
PMID- 10786578
TI - Supporting research.
PMID- 10786579
TI - Bacterial contamination of curtains in clinical areas.
AB - A small-scale study carried out by student nurses revealed ward curtains to be a
source of contaminants and bacteria, including MRSA. Patients and medical staff
can contaminate and be contaminated by bacteria which may be a source of cross
infection. Recommendations from the study included the promotion of further
research in this area and more frequent laundering of curtains.
PMID- 10786580
TI - Filming in hospitals: ethical and methodological issues.
AB - Filming people in hospital poses ethical problems for researchers, film-makers
and healthcare staff. This article describes the safeguards which need to be put
in place to protect patients and those who may be filmed during the course of
their work.
PMID- 10786581
TI - The trouble with specialised language for nursing.
AB - Liam Clarke continues the discussion about the need for a specialised nursing
language and argues that the ordinary social and moral rules governing everyday
speech should suffice.
PMID- 10786582
TI - Getting into business: how nurses can make a difference.
AB - In this article, the authors explore some of the key concepts and practices
associated with the 'business of nursing' and look at the opportunities presented
to nurses for taking a greater role in important business decisions.
PMID- 10786583
TI - Infection control.
PMID- 10786584
TI - Playing to the crowd.
PMID- 10786585
TI - Clearing the first hurdle.
PMID- 10786586
TI - Second level should not mean second class.
PMID- 10786587
TI - Dark side of the law.
PMID- 10786588
TI - Prejudicial conduct.
PMID- 10786589
TI - Army dreamers.
PMID- 10786590
TI - What is the mental health national service framework?
PMID- 10786592
TI - England's newly appointed chief nurse has a job description fit for superwoman.
PMID- 10786591
TI - Pooling power.
PMID- 10786593
TI - Spread the word: you are the tops.
PMID- 10786594
TI - Nurse heroes of the century. Interview by Jeannette Davidson.
PMID- 10786595
TI - Shared learning. Together we can do it.
PMID- 10786596
TI - Stand up and be counted.
PMID- 10786597
TI - Nursing strategy. In for the big catch.
PMID- 10786598
TI - Public health. Safe as houses.
PMID- 10786599
TI - Gain from pain.
PMID- 10786600
TI - People with impaired memory often lack self-confidence and have high anxiety
levels.
PMID- 10786601
TI - Bladder cancer: its diagnosis and treatment.
PMID- 10786602
TI - Take the medical model out of the menopause.
PMID- 10786604
TI - New, but hardly improved.
PMID- 10786603
TI - Tetanus--death by toxin.
PMID- 10786605
TI - And so to beds.
PMID- 10786606
TI - Respiratory care. The outsider.
PMID- 10786607
TI - Respiratory care. Air apparent.
PMID- 10786608
TI - Alert to allergies.
PMID- 10786609
TI - Theatre nursing takes centre stage.
PMID- 10786610
TI - Digital rectal examination--2.
PMID- 10786611
TI - Properties of the delayed rectifier potassium current in porcine sino-atrial node
cells.
AB - 1. Whole-cell currents were recorded in single, spontaneously active cells
dissociated from porcine sino-atrial node, and the conductance and gating
properties of the delayed rectifier K+ current (I(K)) were investigated. 2. The
isolated cells exhibited spontaneous action potentials at a rate of 80.5 +/- 5.4
min(-1) (mean +/- S.E.M., n = 11). Under Ca2+ current block, (depolarization from
-40 mV to various potentials activated a time-dependent outward current (I(K)).
The activation curve of I(K) showed a half-activation potential (V1/2) of 20.5 +/
2.1 mV and a slope factor (S) of 16.4 +/- 1.2 mV (n = 8). 3. As the duration of
the depolarizing pulse to either +10 or +60 mV was prolonged, the amplitude of
the tail current increased in proportion to that of the activated outward current
during depolarization. 4. E4031 (2-5 microM), a selective blocker for the rapidly
activating component of I(K) (I(K,r)), hardly affected I(K), but chromanol 293B,
a selective blocker for the slowly activating component (I(K,s)), inhibited I(K)
with an IC(50) of 8.79 microM. 5. The reversal potential of I(K) was -75.2 +/-
2.3 mV with 5.4 mM external and 150 mM internal K+. The time courses of
activation and deactivation of I(K) were fitted by the sum of two exponential
functions at various potentials. The relationship between the time constants and
membrane potential showed a bell-shaped curve with a peak at around -10 mV for
both fast and slow components. 6. The results indicate that in porcine sino
atrial node cells I(K) is largely derived from I(K,s) and that I(K,s) plays a
functional role in in the slow diastolic depolarization. I(K,s) may, in part,
account for the relatively slower heart rate of pigs than that of rabbit in which
I(K,r) is a functionally dominant component of I(K).
PMID- 10786612
TI - The stability and maturation of the H2A histone mRNAs from Trypanosoma cruzi are
implicated in their post-transcriptional regulation.
AB - We have recently described that the Trypanosoma cruzi histone H2A genes are
actively transcribed as two sized classes of polyadenylated transcripts and that
they differ in the 3'-UTRs due to the insertion of a partial SINE sequence in the
3'-end of some of H2A gene units. The expression of the H2A genes in the non
replicative trypomastigote forms is very low, whereas in the replicative forms,
there is significant and constitutive transcription of the H2A genes probably
regulated in a posttranscriptional way and associated to DNA replication. The
data presented in this paper reveal that in epimastigotes, the steady-state
levels of the H2A mRNAs are determined by controlling the stability of the
messengers in the cytoplasm, most likely mediated by a nuclease attack. The data
also indicate that there must be an additional control, associated to the
parasite growth phase, which may act at the maturation step of the transcripts.
The data suggest, moreover; that the cytoplasmic level of the H2A protein might
be involved in the regulation of its own synthesis by controlling translation of
existing messengers.
PMID- 10786613
TI - Identification of the copper chaperone SAH in Ovis aries: expression analysis and
in vitro interaction of SAH with ATP7B.
AB - A clone encoding the putative copper chaperone protein Sheep Atx1 Homologue (SAH)
was isolated from a sheep liver cDNA library. The 466-bp cDNA encoded a predicted
protein of 68 amino acids, with 44 and 81% amino acid identity to the yeast Atx1
and human Atox1 copper chaperone proteins, respectively. The characteristic
MTCxxC and KTGK motifs were conserved in SAH. Northern blot analysis revealed an
abundant 0.5-kb mRNA in all tissues examined. Elevated hepatic copper content did
not affect the level of SAH mRNA in the liver. Analysis of SAH mRNA in the
developing liver revealed low levels of expression in the foetal period, with a
steady increase to adult levels occurring during development. In vitro two-hybrid
analysis demonstrated SAH interacted with the amino terminal portion of the sheep
Wilson's disease protein (ATP7B). The extent of this interaction was
significantly reduced by the addition of the copper chelator bathocuproine
disulfonic acid to the media. These results suggest SAH is a functional copper
chaperone that is able to interact with ATP7B in a copper-dependent manner to
facilitate copper transport into the secretory pathway.
PMID- 10786614
TI - Primary structure, chromosomal mapping, expression and transcriptional activity
of murine hepatocyte nuclear factor 4gamma.
AB - We demonstrate the presence of a new member of the orphan nuclear receptor
hepatocyte nuclear factor 4 (HNF4) subfamily in mouse which is genetically
distinct from the previously characterized mouse HNF4alpha gene. The new member
of the HNF4 subfamily shows highest amino acid identity, similar tissue
distribution and syntenous chromosomal localization to the recently described
human HNF4gamma (NR2A2), we therefore classify it as mouse HNF4gamma
(mHNF4gamma). A combination of RT-PCR and immunohistochemical analysis showed
expression of mHNF4gamma mRNA and protein in the endocrine pancreas, testes,
kidney and gut. By co-transfection experiments, we show that mHNF4gamma is able
to activate transcription, acting through binding sites that have been previously
characterized as HNF4alpha binding sites. The presence of HNFgamma in human and
mouse implies that a complex transcriptional network exists in higher vertebrates
involving a number of HNF4 members with overlapping yet distinct function and
tissue distribution.
PMID- 10786615
TI - Differential regulation of glutaredoxin gene expression in response to stress
conditions in the yeast Saccharomyces cerevisiae.
AB - Glutaredoxins are small heat-stable proteins that are active as glutathione
dependent oxidoreductases and are encoded by two genes, designated GRX1 and GRX2,
in the yeast Saccharomyces cerevisiae. We report here that the expression of both
genes is induced in response to various stress conditions including oxidative,
osmotic, and heat stress and in response to stationary phase growth and growth on
non-fermentable carbon sources. Furthermore, both genes are activated by the high
osmolarity glycerol pathway and negatively regulated by the Ras-protein kinase A
pathway via stress-responsive STRE elements. GRX1 contains a single STRE element
and is induced to significantly higher levels compared to GRX2 following heat and
osmotic shock. GRX2 contains two STRE elements, and is rapidly induced in
response to reactive oxygen species and upon entry into stationary phase growth.
Thus, these data support the idea that the two glutaredoxin isoforms in yeast
play distinct roles during normal cellular growth and in response to stress
conditions.
PMID- 10786616
TI - Functional expression in Pichia pastoris of human and rat intrinsic factor.
AB - Intrinsic factor (IF) has been expressed previously in Baculovirus with a yield
(0.1-1 mg/l) that was inadequate for structural and metabolic studies. IF cDNAs
were cloned into the shuttle vector pPIC9 of P. pastoris, and the proteins were
induced and purified by cobalamin (Cbl) affinity chromatography. Expression of
recombinant proteins revealed a major band of 49 kDa for both human and rat IF.
Expression of human IF was achieved at 1040 mg/l, but of rat IF at only 1-2 mg/l.
Reaction of human IF with a photo-activatable derivative of Cbl was demonstrated
by Western blotting, and detection of IF fragments by anti-Cbl monoclonal
antibody and by amino-terminal sequencing revealed at least three regions
(residues 129-151, 234-254, and +294) linked to Cbl. Both recombinant human and
rat [125I]IF-Cbl bound to rat and guinea pig brush border membranes with similar
affinity, but the binding capacity of human IF for the rat receptor was only 10%
compared with rat IF. All six amino acids within the previously identified N
terminal binding region of human IF were mutated to be identical to rat IF, but
the resulting chimeric IF still bound poorly to rat membranes. Mutations of
residues 26/27 (Glu26 to Asp and Asn27 to Gln) and 32/34 (Ser32 to Thr and Tyr34
to Arg) showed changes in both Ka and Vmax, with great effects on Vmax. In
conclusion, P. pastoris is an expression system that produces functional human IF
at a higher yield than in the baculovirus system. Cbl binding was directly
demonstrated at multiple sites along the linear sequence of human IF. The
receptor binding function of the amino terminal sequence 25 62 has been
confirmed, but it is insufficient to reproduce all the features of IF-Cbl
binding.
PMID- 10786617
TI - Molecular characterization of a murine, major A/B type hnRNP protein: mBx.
AB - We have previously identified a discrete hnRNP polypeptide of the A/B type, named
mBx, as an abundant protein species in murine cells. The molecular
characterization of this protein is now accomplished. From all evidence provided,
mBx polypeptide represents a new gene product, distinct from the known members of
the A/B family A1 and A2/B1. It is, instead, mostly related to a still
hypothetical human protein of A/B type, as well as to the Xenopus hnRNPA3 protein
species.
PMID- 10786618
TI - Induction of hepatitis B virus gene expression at low temperature.
AB - There is a limited understanding of the cellular regulation of HBV gene
expression in differentiated hepatocytes. We previously demonstrated that HBV
replication inversely correlates with cell proliferation and DNA synthesis. In
this report, temperature-induced modulation of cell growth was used as a novel
approach to study HBV gene expression in the absence of indirect effects from
drugs or serum deprivation. We observed markedly elevated levels of hepatic HBV
mRNA expression from integrated and episomal HBV DNA at 32 degrees C.
Additionally, hepatoblastoma cells cultured at 32 degrees C expressed increased
levels of albumin mRNA and decreased levels of c-myc mRNA, which demonstrates
that liver-derived cells cultured at low temperature exhibit characteristics of
functional and differentiated hepatocytes. In transiently transfected HepG2 cells
cultured at 32 degrees C, the HBV enhancer 1 activated the X promoter and
core/pregenomic promoter by 7.3- and 28-fold, respectively. In the absence of
enhancer 1, core/pregenomic promoter activity was 2.4-fold higher than the X
promoter in HepG2 cells at 32 degrees C. In contrast, enhancer 1 exclusively
activated the X promoter in transfected non-liver cells at 32 degrees C.
Therefore, the core/pregenomic promoter exhibits strict liver-specificity at low
temperature. This work supports the hypothesis that HBV replication and gene
expression are optimal in non-activated hepatocytes, and provides a novel system
for delineating molecular aspects of the HBV replication process.
PMID- 10786619
TI - Intron 1 rather than 5' flanking sequence mediates cell type-specific expression
of c-myb at level of transcription elongation.
AB - Previous studies have shown that expression of steady-state c-myb mRNA was
regulated primarily by a block in intron 1 during transcription elongation. This
study shows that the block site maps approximately 1700 bp from the start of the
intron. Studies based on a reporter construct containing c-myb flanking region
and intron 1 suggest that the flanking region is not important in the regulation
of the cell type-specific expression of c-myb. RNA splicing of intron 1 may
enhance the expression in a non-cell type-specific manner. A conserved intron
domain comprising the block site is required for defining this site, but this
function of the domain is independent of cell type. The cell type-specific
regulation of c-myb transcription elongation is mediated by a 5' intron sequence.
A mechanism for down regulation of c-myb gene expression by the block to
transcription elongation has been proposed.
PMID- 10786620
TI - Molecular characterization of a new arcelin-5 gene.
AB - Arcelins are insecticidal proteins found in some wild accessions of the common
bean, Phaseolus vulgaris. They are grouped in six allelic variants and arcelin-5
is the variant with the highest inhibitory effect on the development of Zabrotes
subfasciatus larvae. Characterization of the protein and its genes resulted in
the identification of three polypeptides and the isolation of two genes that
encode the Arc5a and Arc5b polypeptides. Here we describe a new gene, Arc5-III.
The protein it encodes has 81% amino acid identity with the derived amino acid
sequences of Arc5-I and Arc5-II. The Arc5-III gene is highly expressed in
developing seeds and at a much lower level in roots. Data obtained by a
combination of two-dimensional gel electrophoresis, protein sequencing and MALDI
TOF mass spectrometry analysis support the conclusion that Arc5-III encodes a
polypeptide present in Arc5c band. Using ion-exchange chromatography, three
fractions containing arcelin-5 polypeptides were eluted by increasing the salt
concentration. The three fractions contain various amounts of the three arc-5
polypeptides and inhibit the growth of Zabrotes subfasciatus larvae
differentially, suggesting differences in insecticidal activity among the arcelin
5 isoforms.
PMID- 10786621
TI - Promoter activity of the 5' flanking region of the complement receptor type 1
(CR1) gene: basal and induced transcription.
AB - The luciferase reporter gene system was used to assay the basal and Ara-C induced
promoter activity of the human CR1 gene in K-562 erythroleukemia cells. Based on
the results from clones of nested deletions, both basal and induced reporter gene
activity fell to promoterless levels between constructs containing 79 bp (-79)
and 41 bp (-41) upstream of the transcription start site. The -79 fragment was
shifted in electrophoretic mobility assays using nuclear extracts from Ara-C
induced and non-induced cells while the -41 bp fragment was not shifted. These
data suggest that the 38 bp region between these constructs is necessary for the
transcriptional activity of the CR1 gene and is involved in specifically binding
transcription factors from the nuclei of induced and non-induced cells. Several
potential transcription factor binding sites in this region were identified.
PMID- 10786622
TI - cDNA cloning of the mammalian sterol C5-desaturase and the expression in yeast
mutant.
AB - Sterol C5-desaturase (SC5D) cDNA is an enzyme that catalyzes the dehydrogenation
to introduce C5-6 double bond into lathosterol in cholesterol biosynthesis. We
have isolated and sequenced the cDNA clones encoding human and mouse SC5D. The
functional complementation of a defective yeast mutant proves that the human and
mouse cDNA clones encode SC5D. Mammalian SC5D was presumed as an integral
membrane protein containing histidine residues conserved also in yeasts and
plant.
PMID- 10786623
TI - cDNA cloning and chromosomal mapping of the gene encoding adenylate kinase 2 from
Drosophila melanogaster.
AB - As a step toward understanding of the role of adenylate kinase (AK) in energy
metabolism, we analyzed this enzyme in Drosophila melanogaster. The enzyme
activities of all three AK isozymes were determined in cell-free extracts of
flies, and their proteins were detected by Western blot analysis using polyclonal
antibodies against the mammalian isozymes. A cDNA encoding adenylate kinase was
isolated from D. melanogaster cDNA library. The cDNA encodes a 240-amino acid
protein, which shows high similarity to bovine, human and rat AK2, and hence was
named DAK2. Preliminary subcellular fractionation analysis indicated that DAK2 is
localized in both cytoplasm and mitochondria. In situ hybridization to salivary
gland polytene chromosomes revealed that the Dak2 gene is located at 60B on the
right arm of the second chromosome.
PMID- 10786624
TI - Identification of archaeal genes encoding a novel stationary phase-response
protein.
AB - A novel stationary phase-response protein has been identified in the acid-soluble
protein extract of the thermophilic archaeon, Thermococcus zilligii. N-Terminal
sequencing data were used to identify likely genes for homologues of the protein
in the complete genome sequences of various archaeal species. The corresponding
genes were identified and analysed. The genes encode a protein ranging from 83 to
92 amino acids in length, with a calculated pI ranging from 4.6 to 9.7. The amino
acid sequences of the genes were highly conserved, even between members belonging
to the different archaeal kingdoms. The computed secondary structure of the
protein indicates it consists of four large helical regions separated by short
coiled regions. We propose this protein as a candidate regulator of gene
expression in stationary phase.
PMID- 10786625
TI - Stage-specific expression of a novel isoform of mouse FGF-14 (FHF-4) in
spermatocytes.
PMID- 10786626
TI - A cDNA from the green alga Spermatozopsis similis encodes a protein with homology
to the newly discovered Roadblock/LC7 family of dynein-associated proteins.
AB - A clone, designated as B15, was isolated from a cDNA library of the unicellular
green alga Spermatozopsis similis and characterised. The deduced amino acid
sequence of its open reading frame exhibits high homology to members of the
recently discovered roadblock/LC7 protein family (robl/LC7) of dynein-associated
proteins. Homologies were highest to a robl/LC7-member from human testis (86%,
identity 56%) and to the roadblock protein of Drosophila (88%, identity 52%).
Data bank analyses revealed no homologies to known higher plant proteins. B15 is
a single copy gene in the genome of Sperm-latozopsis and its transcript was
detectable throughout the cell cycle.
PMID- 10786627
TI - Characterisation of a novel murine intestinal serine protease, DISP.
AB - A putative novel murine serine protease, DISP, was identified by cDNA indexing
and shown to be expressed primarily in distal gut. FISH analysis showed it to be
localised to mouse chromosome 17A3. A possible human homologue for DISP has been
identified. DISP is a novel member of clan SA/family S1 of the serine proteases,
at present of unknown function.
PMID- 10786628
TI - Characterization of three new manganese peroxidase genes from the ligninolytic
basidiomycete Ceriporiopsis subvermispora.
AB - Three new genes (Cs-mnp2A, Cs-mnp2B and Cs-mnp3) coding for manganese-dependent
peroxidase (MnP) have been identified in the white-rot basidiomycete
Ceriporiopsis subvermispora. The mature proteins contain 366 (MnP2A and MnP2B)
and 364 (MnP3) amino acids, which are preceded by leader sequences of 21 and 24
amino acids, respectively. Cs-mnp2A and Cs-mnp2B appear to be alleles, since the
corresponding protein sequences differ in only five residues. The upstream region
of Cs-mnp2B contains a TATA box, AP-1 and AP-2 sites, as well as sites for
transcription regulation by metals (two), cAMP (two) and xenobiotics (one). Some
of these elements are also found in the regulatory region of Cs-MnP3.
Transcription of Cs-mnp2A and Cs-mnp2B, but not that of Cs-mnp3, is activated by
manganese.
PMID- 10786629
TI - cDNA cloning and expression of a novel estrogen receptor beta-subtype in goldfish
(Carassius auratus).
AB - We have isolated a second goldfish estrogen receptor (ER) beta-subtype (gfER
beta2) cDNA which is distinct from the liver-derived ER-beta (gfER-beta1) cDNA
reported previously. The 2650-bp cDNA, isolated from a goldfish pituitary and
brain cDNA library, encodes a 610 amino acid (aa) protein which shows only a 53%
aa sequence identity with gfER-beta1 in overall structure. RT-PCR analysis showed
that mRNA of gfER-beta2, in contrast to that of gfER-beta1, was predominantly
expressed in pituitary, telencephalon and hypothalamus as well as in liver of
female goldfish. The existence of a second distinct ER-beta subtype opens new
dimensions for studying tissue-specific regulation of gene expression by estrogen
in the tetraploid goldfish.
PMID- 10786630
TI - Characterisation, chromosomal localisation and expression of the mouse Kid3 gene.
AB - Kid1 encodes a transcriptional repressor implicated in the differentiation of
renal epithelial cells. Here we report the characterisation of Kid3, a novel
mouse gene related to Kid1. Kid3 encodes a C2H2 zinc finger protein with an N
terminal KRAB transcriptional repression domain. It maps to chromosome 11,
adjacent to Kid1 and another related gene Kid2. Northern analysis shows that Kid3
is highly expressed in embryonic and adult brain, with lower levels in adult and
embryonic (E16.5) kidney, gut, lung and heart. Expression of Kid3 in the kidney
is developmentally regulated and suggests a role for Kid3 in the early stages of
nephrogenesis.
PMID- 10786631
TI - Identification and expression of the gene encoding phosphonopyruvate
decarboxylase of Streptomyces hygroscopicus.
AB - The first step of C-P compound biosynthesis is a C-P bond formation reaction
catalyzed by phosphoenolpyruvate phosphomutase, but this reaction favors the
cleavage of the C-P bond. This C-P bond forming reaction is driven by the
following reaction catalyzed by phosphonopyruvate (PnPy) decarboxylase. We have
cloned and sequenced the gene (bcpC) encoding PnPy decarboxylase, a key enzyme of
C-P compound biosynthesis, from the bialaphos (BA) producing microorganism
Streptomyces hygroscopicus by complementation methods using Streptomyces
wedmorensis NP-7, which is a mutant of a fosfomycin producing strain deficient in
this step. The location of this gene in the BA biosynthetic gene cluster was
determined by using the expression system in Streptomyces lividans. DNA
sequencing of this gene revealed a 1203-bp open reading frame encoding a
polypeptide of 401 amino acids.
PMID- 10786632
TI - Molecular cloning and characterization of a novel human gene (HERNA) which
encodes a putative RNA-helicase.
AB - A full-length cDNA encoding a novel protein was isolated and sequenced from a
human hepatocellular cDNA library. This cDNA consists of 7037 base pairs and has
a predicted open reading frame encoding 1924 amino acids. It possesses an RNA
helicase motif containing a DEXH-box in its amino-terminus and an RNase motif in
the carboxy-terminus. From a striking homology to Caenorhabditis elegans K12H4.8,
it might be a human homolog of the K12H4.8. PCR-based mapping with both a
monochromosomal hybrid panel and radiation hybrid cell panels placed the gene to
human chromosome 14q31 near the marker D14S605.
PMID- 10786633
TI - A new human member of the MYST family of histone acetyl transferases with high
sequence similarity to Drosophila MOF.
AB - We have identified a novel human gene product, hMOF, which exhibits significant
similarity to the Drosophila dosage compensation regulator, MOF. A recombinant C
terminal portion of hMOF has histone acetyltransferase activity directed toward
histones H3, H2A and H4, a specificity characteristic of other MYST family
histone acetyltransferases. Based on hMOF's chromodomain, we discuss possible
interactions with other proteins.
PMID- 10786635
TI - Sequencing, tissue distribution and chromosomal assignment of a novel ubiquitin
specific protease USP23.
AB - We have identified human and mouse cDNAs encoding a novel ubiquitin-specific
protease designated USP23. Both cDNAs encode a 62-kDa protein containing the
highly conserved His and Cys domains characteristic of the C19 cysteine protease
family of ubiquitin-specific processing proteases (UCH-2). Human tissue Northern
blots revealed USP23 to be ubiquitously expressed, whereas USP12, its closest
human paralogue, displayed a more restricted expression pattern. The human USP23
gene mapped to chromosome 1q22.
PMID- 10786634
TI - Nucleotide sequence of a cDNA clone coding for an intestinal-type fatty acid
binding protein and its tissue-specific expression in zebrafish (Danio rerio).
AB - We have cloned a cDNA from zebrafish (Danio rerio) that contains an open-reading
frame of 132 amino acids coding for a fatty acid binding protein (FABP) of
approximately 15 kDa. Multiple sequence alignment revealed extensive amino acid
identity between this zebrafish FABP and intestinal-like FABPs (I-FABP) from
other species. The zebrafish I-FABP cDNA hybridized to single restriction
fragments of total zebrafish genomic DNA digested with the restriction
endonucleases PstI Bg/II or EcoRI suggesting that a single copy of the I-FABP
gene is present in the zebrafish genome. An oligonucleotide probe complementary
to the zebrafish I-FABP mRNA hybridized to an mRNA of approximately 800 bases in
Northern blot analysis. In situ hybridization revealed that the I-FABP mRNA was
expressed exclusively in the intestine of the adult zebrafish.
PMID- 10786636
TI - Nuclear receptor binding factor-2 (NRBF-2), a possible gene activator protein
interacting with nuclear hormone receptors.
AB - A protein named nuclear receptor binding factor-2 (NRBF-2) was identified by
yeast two-hybrid screening, as an interaction partner of peroxisome proliferator
activated receptor alpha as well as several other nuclear receptors. NRBF-2
exhibited a gene activation function, when tethered to a heterologous DNA binding
domain, in both mammalian cells and yeast.
PMID- 10786637
TI - Molecular cloning of a homologue of dad-1 gene in citrus: distinctive expression
during fruit development.
AB - A cDNA homologue to the human defender against apoptotic death gene (dad-1),
which is involved in programmed cell death, was isolated from satsuma mandarin
(Citrus unshiu Marc.) fruit. It (Citdad-1-1) was 345 bp long, with a deduced
protein sequence of 115 amino acids. Southern hybridization suggests that dad-1
related sequences are present as a small gene family in the citrus genome.
Expression of Citdad-1-1 was progressively down-regulated in leaves as they
matured, but not in juice sac/segment epidermis (edible part) towards fruit
ripening. The role of dad-1 during citrus development is also discussed.
PMID- 10786638
TI - Isolation and characterization of isoforms of HspBP1, inhibitors of Hsp70.
AB - The protein sequences derived from cDNA sequences for Hsp70 binding proteins from
human (HspBP2) and rat tissues (HspBPR) are presented in this paper. The derived
amino acid sequences of these proteins differ from human HspBP1 in the number of
consecutive glycines near the amino-terminus. These differences, however, do not
alter the inhibitory activity.
PMID- 10786639
TI - A region of the Agrobacterium tumefaciens chromosome containing genes required
for virulence and attachment to host cells.
AB - A 29 kb region of the circular chromosome of Agrobacterium tumefaciens containing
genes required for bacterial attachment to host cells and virulence has been
sequenced. Transposon mutants in many of the genes have been obtained. The
mutants can be divided into two groups: those which can be complemented by
conditioned medium and those whose phenotype is unaffected by conditioned medium.
The first group includes mutants in genes with homology to ABC transporters, one
possible transcriptional regulator, and some closely linked genes immediately
downstream. The second group includes mutants in two possible transcriptional
regulators, one ATPase, and a number of biosynthetic genes including a
transacetylase required for the formation of an acetylated capsular
polysaccharide. There are also several genes with no homology to genes of
identified function. The presence of such a large number of genes required for
attachment to host cells suggests that the ability of A. tumefaciens to bind to
plant cells may play an important role in the life of these bacteria.
PMID- 10786640
TI - Reduced maximal cardiac output at altitude--mechanisms and significance.
AB - When a lowlander ascends to altitude and acclimatizes over days to weeks, both
maximal exercise capacity and maximal cardiac output are reduced compared to sea
level. Of the several possible mechanisms underlying this reduction of maximal
cardiac output, the available data are interpreted as supporting the simplest
hypothesis--that this merely reflects the reduced requirement for muscle blood
flow that results from the arterial hypoxemia of altitude (which reduces muscle
O2 availability and thus maximal muscle function). The competing hypotheses, that
increased blood viscosity, reduced blood volume, autonomic nervous system changes
or myocardial hypoxic dysfunction reduce maximal cardiac output, are not well
supported by existing data. However, critical tests of some of these hypotheses
remain to be devised and undertaken. When it comes to the question of the
importance of reduced maximal cardiac output to V(O2) MAX at altitude, the
available evidence suggests that cardiac output is not a major limiting variable.
This is because as cardiac output rises, gains in convective flow of O2 in the
circulation are offset by losses from greater diffusion impairment of O2 transfer
in the lungs and muscles, and vice versa. However, just as with the mechanism of
cardiac output reduction itself, clear-cut experimental tests of its role in
limiting exercise at altitude remain to be conducted.
PMID- 10786641
TI - A model of the chemoreflex control of breathing in humans: model parameters
measurement.
AB - We reviewed the ventilatory responses obtained from rebreathing experiments on a
population of 22 subjects. Our aim was to derive parameter estimates for an
'average subject' so as to model the respiratory chemoreflex control system. The
rebreathing technique used was modified to include a prior hyperventilation, so
that rebreathing started at a hypocapnic P(CO2) and ended at a hypercapnic
P(CO2). In addition, oxygen was added to the rebreathing bag in a controlled
manner to maintain iso-oxia during rebreathing, which allowed determination of
the response at several iso-oxic P(O2) levels. The breath-by-breath responses
were analysed in terms of tidal volume, breathing frequency and ventilation. As
P(CO2) rose, ventilation was first steady at a basal value, then increased as
P(CO2) exceeded a breakpoint. We interpreted this first breakpoint as the
threshold of the combined central and peripheral chemoreflex responses. Above,
ventilation increased linearly with P(CO2), with tidal volume usually
contributing more than frequency to the increase. When breathing was driven
strongly, such as in hypoxia, a second breakpoint P(CO2) was often observed.
Beyond the second breakpoint, ventilation continued to increase linearly with
P(CO2) at a different slope, with frequency usually contributing more than tidal
volume to the increase. We defined the parameters of the variation of tidal
volume, frequency and ventilation with P(O2) and P(CO2) for an average subject
based on a three-segment linear fit of the individual responses. These were
incorporated into a model of the respiratory chemoreflex control system based on
the general scheme of the 'Oxford' model. However, instead of considering
ventilatory responses alone, the model also incorporates tidal volume and
frequency responses.
PMID- 10786642
TI - Autoreceptor mechanism regulating carotid body dopamine release from adult and 10
day-old rabbits.
AB - Dopamine (DA) release (r) from the carotid body (CB) is thought to be modulated
by feedback inhibition mediated by DA D2 autoreceptors. We tested the hypothesis
that CB DAr is autoregulated in a concentration and age dependent manner. Using
an in vitro CB infusion model [Bairam, A., Marchal. F., Cottet-Emard, J.M.,
Basson, H., Pequignot, J.M., Hascoet, J.M., Lahiri, S., 1996b. Effects of hypoxia
on carotid body dopamine content and release in developing rabbits. J. Appl.
Physiol. 80, 20-24.], we evaluated under unstimulated conditions the effects of
0.001, 0.01, 0.1, 1.0 and 10.0 microM of the specific DA D2 receptor antagonist
domperidone on CB DAr in adult rabbits. In 10-day-old rabbit pups, concentrations
of 0.01, 0.1, 1.0 microM were studied. In adult CBs, domperidone increased DAr in
a concentration-dependent manner. DAr (pmol/h) was significantly greater compared
to control (without domperidone) starting at a domperidone concentration of 0.1
microM (P<0.01). In 10-day-old pup CBs, 1.0 microM domperidone was required to
produce a significant increase of DAr (pmol/h) compared to control (P<0.005).
However, control DAr (as % of total catecholamine) was about 40%; significantly
higher than 24% observed in adult CBs (P<0.001). We conclude that in rabbit CB,
DAr is controlled by an autoreceptor mechanism in a concentration-dependent
manner and this mechanism is less developed in pups than in adults.
PMID- 10786643
TI - Respiratory function in a newborn marsupial with skin gas exchange.
AB - The Julia Creek dunnart (Sminthopsis douglasi) is a marsupial born after
approximately 12 days of gestation. At birth, the newborn is approximately 4 mm
long and weighs approximately 15 mg. Gaseous metabolism (oxygen consumption rate,
V(O2), rate of carbon dioxide production, V(CO2) was measured separately across
the airways (lungs) and the rest of the body (skin). At pouch temperature (36
degrees C) total V(O2) (i.e. skin + lungs) averaged 15 +/- 2 S.E.M. ml x kg(-1) x
min(-1). At birth the skin contributed almost the total gaseous metabolism, and
at 3 weeks approximately 1/3 of the total. The compliance of the respiratory
system, per unit of body weight, was similar to that of other newborn mammals.
During the first postnatal days breathing was an occasional event determined by
gross body movements. Artificial expansion of the lungs temporarily stopped
breathing, presumably a manifestation of the Hering-Breuer reflex. By the 2nd-3rd
week breathing was regular, pulmonary ventilation (V(E)) averaged 263 ml x kg(-1)
x min(-1), tidal volume (V(T)) 3.4 ml x kg(-1), breathing frequency (f) 87
breaths x min(-1). Lowering ambient temperature in steps from 36 to 20 degrees C
reduced both lung and skin gaseous metabolism. V(E) and f, at first, were little
affected but eventually they dropped in approximate proportion to metabolism,
whereas V(T) remained unchanged. In conclusion, for the newborn dunnart gas
exchange through the skin is a requirement because of the inefficient V(E). To
what extent the V(E) adjustments to changes in metabolic rate reflect mechanisms
of regulation remains unresolved.
PMID- 10786644
TI - Cardiovascular and respiratory reflexes in the tropical fish, traira (Hoplias
malabaricus): CO2/pH chemoresponses.
AB - To examine the distribution and physiological role of CO2/pH-sensitive
chemoreceptors in the gills of the tropical fish, traira (Hoplias malabaricus),
fish were exposed to acute environmental hypercarbia (1.25, 2.5 and 5.0% CO2 in
air) and subjected to injections of HCl into the ventral aorta and buccal cavity.
This was done before and after selective denervation of branchial branches of the
IXth and Xth cranial nerves to various gills arches. Hypercarbia produced a
significant decrease in heart rate, a mild hypotension as well as increases in
both ventilation rate and ventilation amplitude. The data suggest that the
hypercarbic bradycardia and increase in ventilation frequency arise from
receptors exclusively within the gills but present on more than the first gill
arch, while extra-branchial receptors may also be involved in controlling the
increase in ventilation amplitude. With the exception of a decrease in heart rate
in response to HCl injected into the ventral aorta, the acid injections (internal
and external) did not mimic the cardiorespiratory responses observed during
hypercarbia suggesting that changes in CO2 are more important than changes in pH
in producing cardiorespiratory responses. Finally, the data indicate that
chemoreceptors sensitive to CO2/pH and to O2 in the gills of this species
involved in producing ventilatory responses are distributed in a similar fashion,
but that those involved in producing the bradycardia are not.
PMID- 10786645
TI - Effect of hydrocortisone on platelet activating factor induced lung edema in
isolated rabbit lungs.
AB - The effect of hydrocortisone on platelet activating factor (PAF)-induced
pulmonary edema is studied. Thirty four isolated and perfused rabbit lung
preparations were used: eight control preparations, eight PAF preparations with
two doses of PAF called low dose (LD = 0.5 microg/kg of rabbit weight) and high
dose (HD = 1 microg/kg of rabbit weight). Eighteen preparations divided in three
groups of six were pretreated with doses of 20, 200 and 2000 mg of hydrocortisone
and later given the same doses of PAF as described above. Hydrocortisone
significantly decreased (P < 0.05) the effect of PAF LD over the pulmonary
arterial pressure (Ppa) in the 200 and 2000 mg groups (58 and 89% decrease,
respectively) and it significantly decreased (P < 0.05) the effect of PAF HD over
Ppa in all hydrocortisone pretreated groups (48, 70 and 96% decrease,
respectively). Fluid filtration rate (FFR) increases mediated by PAF HD were
significantly inhibited (P < 0.05) in the 200 and 2000 mg groups (64 and 96%
decrease, respectively). We conclude that hydrocortisone inhibits the effect of
PAF over the pulmonary circulation.
PMID- 10786646
TI - Pulmonary artery remodeling modifies pulmonary hypertension during exercise in
severe emphysema.
AB - To clarify the relation between the vessel remodeling and the physiology of
pulmonary circulation in chronic obstructive pulmonary disease (COPD), we studied
the pulmonary hemodynamics at rest and during exercise (25W) and the morphology
of pulmonary arteries with external diameters of 100-200 microm in ten patients
with severe emphysema. The wall thickness (WT) was defined as the intima plus
media. The percent WT of the external diameter (% WT) in emphysema (36.0 +/-
4.3%) was significantly increased compared with that (22.6 +/- 3.3%) in five
control lungs. The % WT was not related to pulmonary arterial pressure (Ppa) at
rest, but was highly correlated with exercise Ppa (r = 0.721, P = 0.02) and with
deltaPpa (Ppa during exercise-Ppa at rest) (r = 0.899, P = 0.0004). These
findings suggest that pulmonary artery remodeling leads to reduced recruitability
and distensibility of pulmonary vessels and is closely related to exercise
pulmonary hypertension.
PMID- 10786647
TI - Respiration and gas exchange during recovery from exercise in the American
alligator.
AB - Low respiratory exchange ratios (R) occur in reptiles. In crocodilians they have
been attributed to the loss of respiratory CO2 into the urine and to the
immediate exercise-history of an animal. In this study, expired ventilation
(V(E)), oxygen consumption (V(O2)), and carbon dioxide excretion (V(CO2)) were
measured during recovery from treadmill-exercise in the American alligator. Both
V(O2) and V(CO2) decreased exponentially during recovery, but the decrease of
V(CO2) was greater than that of V(O2). By 55 min into recovery R fell to 0.3 +/-
0.02 (mean +/- S.E.M). These low values of R may be partially attributable to
hyperventilation that occurred during exercise. These data suggest that both
hyperventilation during exercise and a metabolic acidosis deplete blood
bicarbonate stores, contributing to a low R during recovery. We propose that the
right to left cardiac shunt could facilitate restoration of these alkaline
reserves and blood pH.
PMID- 10786648
TI - Emerging role of apoptosis in the pathogenesis of severe neutropenia.
PMID- 10786649
TI - Measurement of KIT ligand/stem cell factor: clinical and biochemical
significance.
AB - Stem cell factor (SCF) and its receptor KIT play an important role in various
biologic phases, such as hematopoiesis, reproduction, and regeneration. It has
been possible to measure both soluble SCF and soluble KIT using enzyme-linked
immunosorbent assay since 1993 and 1995, respectively. Although the significance
of interaction of soluble SCF with soluble KIT has not yet been elucidated, in
certain diseases proteins fluctuate in human sera. We found that serum SCF levels
were fivefold higher in patients with chronic renal failure than levels in
healthy controls. We review the results of the analysis of SCF. In addition,
possible pathologic mechanisms in various clinical abnormalities and the clinical
potential for recombinant human SCF are discussed.
PMID- 10786650
TI - Measurement of thrombopoietic levels: clinical and biological relationships.
AB - Platelet production is primarily regulated by the thrombopoietic cytokine
thrombopoietin (TPO). In most cases thrombopoietin serum levels are determined by
the rate of c-mpl receptor-mediated degradation after TPO uptake into platelets
and megakaryocytes. The contribution of increased TPO protein synthesis by a
translational mechanism was recently appreciated as the cause for hereditary
thrombocythemia and will have to be elucidated in other conditions of
thrombocytosis in association with increased TPO levels.
PMID- 10786651
TI - Granulocyte colony-stimulating factor versus granulocyte-macrophage colony
stimulating factor for collection of peripheral blood progenitor cells from
healthy donors.
AB - The harvesting of peripheral blood progenitor cells (PBPCs) after granulocyte
colony-stimulating factor or granulocyte-macrophage colony-stimulating factor
stimulation instead of bone marrow in healthy donors has become increasingly
popular. Donors, given the choice between bone marrow and PBPC donation, often
prefer cytapheresis because of the easier access, no necessity for general
anesthesia, and no multiple bone marrow punctures. In addition, accelerated
engraftment and immunomodulation by granulocyte colony-stimulating factor
mobilized PBPCs are advantageous for the recipient. However, because of donor
inconvenience and poor mobilization, there is a need to develop improved
procedures. Aspects such as durability of hematopoietic engraftment,
characterization of the earliest stem cell, and composition of PBPCs are not yet
well defined, and international donor registration and follow-up must be
considered when evaluating long-term safety profiles in healthy donors. This
review concentrates on the most significant developments on mobilization of PBPCs
published during the past year.
PMID- 10786652
TI - Cytokine therapy for myelodysplastic syndrome.
AB - The myelodysplastic syndromes are a heterogeneous family of hematologic disorders
characterized by ineffective hematopoiesis. Because of the interpatient
variability regarding prognosis and morbidity, management of myelodysplastic
syndromes continues to be a challenge to clinical hematologists. Pancytopenia and
defective function of neutrophils and platelets carry a high risk of infectious
or hemorrhagic complications. Erythropoietin is perhaps the most commonly used
therapeutic option, second only to transfusion; improvement of erythropoiesis is
seen in approximately 20% of patients, mainly in those with relatively preserved
erythroid function and no or low transfusion requirements. Coadministration of
erythropoietin with either granulocyte colony-stimulating factor or granulocyte
macrophage colony-stimulating factor may increase the response rate up to 50%.
Although prophylactic administration of granulocyte- or granulocyte-macrophage
colony-stimulating factor cannot be recommended, treatment of febrile neutropenia
might benefit from administration of granulocyte- or granulocyte-macrophage
colony-stimulating factor in addition to antibiotics.
PMID- 10786653
TI - Expression of hematopoietic growth factor receptors on early hematopoietic
precursors: detection and regulation.
AB - Since the original isolation of colony-stimulating factors from human serum,
conditioned medium of murine or human cell lines, or freshly isolated human
mononuclear cells, a revolutionary explosion of ideas has occurred in our
understanding of molecular controls of the hematopoietic stem cell self-renewal
and differentiation. With the availability of techniques of molecular cloning in
the early 1 980s, the first hematopoietically activated cytokines led to
molecular clones expressed in bacteria, yeast, or mammalian cellular systems.
There then followed a development of techniques leading to the molecular cloning
and expression of many hematopoietic growth factors and their receptors, as well
as the primary, secondary, and tertiary molecules in signal transduction into
activation of specific genes for differentiation or self-renewal. The clinical
use of these factors in the diagnosis, treatment, and incorporation into new cell
therapies for a variety of diseases is a subject of current interest.
PMID- 10786654
TI - Uses of granulocyte-macrophage colony-stimulating factor in vaccine development.
AB - Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent cytokine
capable of inducing differentiation, proliferation, and activation of a variety
of immunologically active cell populations. In addition to its effects on
stimulating granulocytic hematopoiesis, it also facilitates development of both
humoral and cellular mediated immunity. Accordingly, strategies involving the use
of GM-CSF as a vaccine adjuvant have attracted considerable attention. These
strategies include the systemic administration of soluble GM-CSF with an
immunogen, and also its use as part of gene therapy approaches to immunization.
Because of the potency of this cytokine as an immune adjuvant, particular
interest has focused on its use to overcome poorly immunogenic antigens such as
those associated with intracellular infections and cancer. This review focuses on
recent advances in the use of GM-CSF as a vaccine adjuvant.
PMID- 10786655
TI - Interleukin-15 and its impact on neutrophil function.
AB - Interleukin-15 is a recently discovered cytokine produced by several cell types
(including fibroblasts, keratinocytes, endothelial cells, and macrophages) in
response to endotoxin or microbial infection. In turn, interleukin-15 has been
shown to act on various cells of the immune system, including T and B
lymphocytes, natural killer cells, monocytes, eosinophils, and circulating
neutrophils. In the latter instance, interleukin-15 was initially observed to
induce cytoskeletal rearrangements, to enhance phagocytosis, to increase the
synthesis of several cellular proteins, and to delay apoptosis. Recently,
interleukin-15 has been found to elicit other functional responses in
neutrophils, such as chemokine production. This review recapitulates advances
made in the area of interleukin-15/neutrophil interactions.
PMID- 10786656
TI - Role of interleukin-8 in neutrophil signaling.
AB - Interleukin-8 was originally discovered as one of the first chemokines activating
neutrophil granulocytes (neutrophils) after secretion by lipopolysaccharide
stimulated monocytes. A wealth of information has been gathered concerning the
intracellular events mediated by interleukin-8 and the role of interleukin-8 in
numerous physiologic and pathophysiologic processes. We discuss recent advances
in the understanding of the initial intracellular signals elicited by interleukin
8. Detailed investigation of these events has led to the identification of subtle
but significant differences in the signal transduction processes evoked by
interleukin-8 receptors. In particular, much has been learned concerning
differences in the cellular mechanisms leading to desensitization,
internalization, and recycling of interleukin-8 receptors, and functional
consequences of interleukin-8 receptor diversity are now being unraveled.
PMID- 10786657
TI - Role of thrombopoietin in hematopoietic stem cell and progenitor regulation.
AB - Thrombopoietin performs an essential role during hematopoiesis by regulating the
expansion and maturation of megakaryocytes. In keeping with this function,
megakaryocytes, platelets, and their precursors all express the thrombopoietin
receptor, Mpl, on their cell surface. However, Mpl is also expressed on
primitive, pluripotent hematopoietic progenitors and plays an important role in
the regulation of lineages other than megakaryocytes as well as primitive
progenitors. Recently, the ability of thrombopoietin to maintain and expand
repopulating stem cells has been demonstrated. Thus, thrombopoietin is unique
among the hematopoietic cytokines because it is necessary both for terminal
maturation and regulation of lineage-specific megakaryocytes and also for
maintenance of the most primitive hematopoietic stem cells. Many new strategies
are evolving to exploit the activity of thrombopoietin on primitive progenitors.
This may lead to faster hematopoietic recovery from marrow-suppressive therapy,
effective methods of ex vivo expansion of hematopoietic stem cells, and
retroviral transduction of stem cells to facilitate gene therapy.
PMID- 10786658
TI - Selection and use of chemotherapy with hematopoietic growth factors for
mobilization of peripheral blood progenitor cells.
AB - Peripheral blood progenitor cells (PBPCs) have become the preferred means of stem
cell support for high-dose chemotherapy in recent years. The biology of PBPC
mobilization is complex and may be influenced by several variables. Signals from
both stromal and hemopoietic cells may induce downregulation of adhesion
molecules and upregulate the expression of metalloproteinases. Cytokines alone
can mobilize PBPCs but a synergistic effect has been shown when they are used in
conjunction with chemotherapy. Disease-specific mobilization strategies appear to
have the advantage of less toxicity, greater stem cell yield, and enhanced
antitumor activity. Studies have demonstrated that the number of peripheral blood
CD34+ cells can be used as a predictor for the timing of apheresis and for
estimating PBPC yield. Similarly the CD34+ cell dose is the strongest predictor
of hematologic recovery after PBPC transplant. Age, prior radiotherapy, marrow
involvement, and prior chemotherapy (especially with alkylating agents) are
important factors influencing the yield of stem cells.
PMID- 10786659
TI - Concurrent use of growth factors and chemotherapy in acute leukemia.
AB - During the past decade, investigators have evaluated the role of hematopoietic
growth factors as cytokines that could potentiate the cytotoxic action of certain
chemotherapeutic agents when administered simultaneously with induction therapy.
Such cytokines included granulocyte-macrophage colony-stimulating factor,
granulocyte colony-stimulating factor, interleukin 3, and stem cell factor. Phase
I and II studies have confirmed a significant biologic activity of such priming
therapy, and the aggregate of subsequent controlled studies have also established
the safety of such manipulations. However, despite the plethora of clinical
trials, data regarding clinical efficacy remain uncertain. It is fair to say that
little progress in our clinical understanding has occurred during the past 24
months and at the present time, the concurrent use of growth factors with
chemotherapy, as a method of enhancing the antileukemic action of cytotoxic
therapy, remains very investigational.
PMID- 10786660
TI - Bibliography. Current world literature. Hematopoietic growth factors.
PMID- 10786661
TI - Nuclear structure-gene expression interrelationships: implications for aberrant
gene expression in cancer.
AB - There is long-standing recognition that transformed and tumor cells exhibit
striking alterations in nuclear morphology as well as in the representation and
intranuclear distribution of nucleic acids and regulatory factors. Parameters of
nuclear structure support cell growth and phenotypic properties of cells by
facilitating the organization of genes, replication and transcription sites,
chromatin remodeling complexes, transcripts, and regulatory factors in
structurally and functionally definable subnuclear domains within the three
dimensional context of nuclear architecture. The emerging evidence for functional
interrelationships of nuclear structure and gene expression is consistent with
linkage of tumor-related modifications in nuclear organization to compromised
gene regulation during the onset and progression of cancer.
PMID- 10786662
TI - Adenoma-specific alterations of protein kinase C isozyme expression in Apc(MIN)
mice.
AB - Members of the protein kinase C (PKC) family appear to play important roles in
colorectal carcinogenesis. To investigate the potential involvement of PKC
isozymes in adenomatous transformation induced by inactivation of the adenomatous
polyposis coli (APC) gene product, we examined protein levels and localizations
of ten PKC isozymes by immunohistochemistry in normal and adenomatous ileal
epithelium of ApcMIN mice. Compared with surrounding normal epithelium, adenomas
showed dramatically reduced staining for PKCs a, beta1, and zeta, as well as
dysplasia-specific punctate nuclear staining of PKC mu. We conclude that reduced
protein expression of PKC alpha, beta1, and zeta, and nuclear localization of PKC
mu are markers of, and are perhaps involved in, adenomatous transformation
induced by APC inactivation in ApcMIN mice.
PMID- 10786663
TI - Flt3-ligand induces transient tumor regression in an ectopic treatment model of
major histocompatibility complex-negative prostate cancer.
AB - We assessed the in vivo efficacy of Flt3-ligand (Flt3-L) treatment in C57BL/6
mice bearing a well-established MHC class I-negative prostate carcinoma TRAMP-C1.
Flt3-L immunotherapy was initiated approximately 30 days after tumor inoculation,
a time when > or =80% of the mice had palpable TRAMP-C1 tumors. Treatment with
Flt3-L at 10 microg/day for 21 consecutive days suppressed TRAMP-C1 tumor growth
and induced tumor stabilization (P = 0.0337). Enhanced tumor regression was
demonstrated at a higher dose of 30 microg/day (P < 0.0001). Tumors excised from
mice treated with Flt3-L were smaller than carrier-treated controls and contained
a more pronounced mixed inflammatory cell infiltrate primarily composed of mphi.
In regressor nice, tumors reappeared at the site of injection when Flt3-L therapy
was terminated. When the experiment was repeated with MHC class I-positive TRAMP
C1 cells, tumor stabilization and/or regression was again observed after
treatment (P < 0.0001); however, once again, tumors reappeared after the
termination of therapy despite an extended treatment schedule (35 days). MHC
class I-negative variants were present in tumors isolated from carrier- and Flt3
L-treated mice, and this phenotype could be reversed by IFN-gamma treatment in
vitro. Thus, Flt3-L treatment of mice with preexisting transplantable prostate
tumors results in tumor regression that is dose-dependent and accompanied by a
pronounced mixed-cell inflammatory tumor infiltrate. However, disease relapse was
invariably observed after the termination of therapy, which suggests that Flt3-L
treatment of advanced MHC- prostate cancers will require adjuvant modalities to
achieve a durable response.
PMID- 10786664
TI - Sulindac and exisulind exhibit a significant antiproliferative effect and induce
apoptosis in human hepatocellular carcinoma cell lines.
AB - This is the first report enumerating a superb antiproliferative effect of both
sulindac and exisulind on hepatocellular cancer cell lines. The growth inhibition
and cytotoxicity of sulindac in human hepatocellular carcinoma cell lines HepG2,
Huh-7, and KYN-2 were investigated by studying cell growth, cell cycle
distribution, and induction of apoptosis. In the presence of sulindac, there was
a marked time- and dose-dependent decrease in cell proliferation and viability.
Also, exisulind exhibited a similar growth-inhibitory effect on the KYN-2 cell
line. The findings of this study suggest that sulindac exhibits a growth
inhibitory effect on human hepatocellular carcinoma cell lines; therefore, these
drugs might serve as an effective tool for hepatocellular carcinoma
chemoprevention.
PMID- 10786665
TI - Identification of a geldanamycin dimer that induces the selective degradation of
HER-family tyrosine kinases.
AB - Geldanamycin (GM) is a natural antibiotic that binds Hsp90 and induces the
degradation of receptor tyrosine kinases, steroid receptors, and Raf. It is a
potent inhibitor of cancer cells that overexpress HER-kinases, but its effects on
other important proteins may cause significant toxicity and limit its clinical
use. We report the synthesis and identification of a GM dimer, GMD-4c, which had
selective activity against HER-kinases. Selectivity was a function of linker
length and required two intact GM moieties. GMD-4c is a potent inducer of G1
block and apoptosis of breast cancer cell lines that overexpress HER2, but does
not appreciably inhibit the growth of 32D cells that lack HER-kinases. GMD-4c
could be useful in the treatment of carcinomas dependent on HER-kinases.
PMID- 10786666
TI - Regulation of TCL1 expression in B- and T-cell lymphomas and reactive lymphoid
tissues.
AB - Chromosomal rearrangements observed in T-cell prolymphocytic leukemia involve the
translocation of one T-cell receptor gene to either chromosome 14q32 or Xq28,
deregulating the expression of cellular protooncogenes of unknown function, such
as TCL1 or its homologue, MTCP1. In the human hematopoietic system, TCL1
expression is predominantly observed in developing B lymphocytes, whereas its
overexpression in T cells causes mature T-cell proliferation in transgenic mice.
In this study, using a newly generated monoclonal antibody against recombinant
TCL1 protein, we extended our analysis mainly by immunohistochemistry and also by
fluorescence-activated cell sorting and Western blot to a large tumor lymphoma
data bank including 194 cases of lymphoproliferative disorders of B- and T-cell
origin as well as reactive lymphoid tissues. The results obtained show that in
reactive lymphoid tissues, TCL1 is strongly expressed by a subset of mantle zone
B lymphocytes and is expressed to a lesser extent by follicle center cells and by
scattered interfollicular small lymphocytes. In B-cell neoplasia, TCL1 was
expressed in the majority of the cases, including lymphoblastic lymphoma, chronic
lymphocytic leukemia, mantle cell lymphoma, follicular lymphoma, Burkitt
lymphoma, diffuse large B-cell lymphoma (60%), and primary cutaneous B cell
lymphoma (55%). TCL1 expression was observed in both the cytoplasmic and nuclear
compartments, as confirmed by Western blot analysis. Conversely, TCL1 was not
expressed in Hodgkin/Reed-Sternberg cells, multiple myelomas, marginal zone B
cell lymphomas, CD30+ anaplastic large cell lymphoma, lymphoblastic T-cell
lymphoma, peripheral T-cell lymphoma, and mycosis fungoides. These data indicate
that TCL1 is expressed in more differentiated B cells, under both reactive and
neoplastic conditions, from antigen committed B cells and in germinal center B
cells and is down-regulated in the latest stage of B-cell differentiation.
PMID- 10786667
TI - Chemoprevention of breast cancer in rats by celecoxib, a cyclooxygenase 2
inhibitor.
AB - Nonsteroidal anti-inflammatory drugs (NSAIDs) have been observed to reduce the
relative risk of breast cancer. This prompted our investigation of the
chemopreventive potential of celecoxib, a specific cyclooxygenase 2 blocker,
against mammary carcinogenesis induced by 7,12-dimethyl-benz(a)anthracene in
female Sprague Dawley rats. Treatment with celecoxib was examined and compared to
treatment with the general NSAID, ibuprofen, and to a control group receiving
only dimethylbenz(a)anthracene. Dietary administration of celecoxib (1500 ppm)
produced striking reductions in the incidence, multiplicity, and volume of breast
tumors relative to the control group (68%, 86%, and 81%, respectively; P <
0.001). Ibuprofen also produced significant effects, but of lesser magnitude
(40%, 52%, and 57%, respectively; P < 0.001). These results help confirm the
chemopreventive activity of NSAIDs against breast cancer and provide the first
evidence that a cyclooxygenase 2 blocking agent, celecoxib, possesses strong
chemopreventive activity against mammary carcinogenesis.
PMID- 10786668
TI - U0126 reverses Ki-ras-mediated transformation by blocking both mitogen-activated
protein kinase and p70 S6 kinase pathways.
AB - U0126, a recently introduced mitogen-activated protein kinase [corrected]
(MAPK)/extracellular signal-regulated kinase kinase inhibitor reversed morphology
and inhibited anchorage-independent growth of Ki-ras-transformed rat fibroblasts.
Immunoblot analyses with phosphospecific antibodies indicated that in addition to
MAPK, U0126 suppressed activation of p70(S6K), but not Akt, at concentrations at
which it normalized the transformed phenotypes. Another MAPK/extracellular signal
regulated kinase kinase inhibitor, PD98059, showed only marginal effects on
p70S6K phosphorylation and did not effectively block Ki-ras-induced
transformation. However, simultaneous inhibition of the MAPK pathway and the
p70S6K pathway by PD98059 in conjunction with the p70S6K inhibitor rapamycin
essentially restored the normal phenotype. U0126 or the combination of PD98059
and rapamycin flattened morphology of v-src-transformed cells, but did not
reverse anchorage independence, although activation of both MAPK and p706K was
blocked. The results suggest that normalization of Ki-ras-induced transformed
phenotypes by U0126 is a consequence of concurrent inhibition of the MAPK and
p70S6K pathways. Intervention of other pathway(s) appears to be required to
completely antagonize transformation by v-src. Simultaneous blockade of more than
one signal transduction pathway by combining selective inhibitors might be
effective in suppressing uncontrolled tumorigenic growth.
PMID- 10786670
TI - Alterations of the INK4a/ARF locus in human intracranial germ cell tumors.
AB - Little is known about the molecular mechanisms responsible for the development of
intracranial germ cell tumors (ICGTs). Recently, we demonstrated that the balance
of the p53-mdm2 interactions is disrupted in ICGTs. The p14ARF product, a tumor
suppresser gene located on the INK4a/ARF locus, acts as one of the major factors
affecting p53-mdm2 interactions via its binding to mdm2 and the stimulation of
mdm2 degradation. To evaluate whether genetic alterations of the INK4a/ARF locus
occur in the genesis of ICGTs, we analyzed the INK4a/ARF genes in 21 ICGTs-10
pure germinomas and 11 nongerminomatous germ cell tumors. Fifteen (71%) of the 21
ICGTs displayed genetic alterations, including 14 homozygous deletions and 1
frameshift mutation. Furthermore, the frequency of the alterations was higher in
pure germinomas [9 (90%) of the 10] than in nongerminomatous germ cell tumors [6
(55%) of the 11; P = 0.09]. These data suggested that INK4a/ARF gene
abnormalities could play an important role in the genesis of ICGTs, especially in
pure germinoma.
PMID- 10786669
TI - The radiosensitizing agent 7-hydroxystaurosporine (UCN-01) inhibits the DNA
damage checkpoint kinase hChk1.
AB - The investigational anticancer agent 7-hydroxystaurosporine (UCN-01) abrogates
the G2 checkpoint in tumor cells and sensitizes them to the lethal effects of
genotoxic anticancer agents. On the basis of the role of the Cdc25C phosphatase
in maintenance of this damage-inducible checkpoint, we hypothesized that UCN-01
inhibits a component of the signal transduction pathway that modulates Cdc25C
phosphorylation. Of the three kinases known to phosphorylate Cdc25C on Ser216,
both checkpoint kinase 1 (hChk1) and Cdc25C-associated protein kinase 1 (cTAK1)
were potently inhibited by UCN-01 with IC50s of 11 and 27 nM, respectively.
Treatment of K562 erythroblastoid leukemia cells with similar drug concentrations
resulted in decreased levels of Ser216 phosphorylation of Cdc25C and complete
disruption of the y-radiation-induced G2 checkpoint. In contrast to hChk1, the
hChk2 kinase was 100-fold more resistant to inhibition by UCN-01 (IC50, 1040 nM).
These results suggest that disruption of the DNA damage-induced G2 checkpoint by
UCN-01 is mediated through the inhibition of the Cdc25C kinases, hChk1 and cTAK1,
and that hChk2 activity is not sufficient to enforce the G2 checkpoint in cells
treated with a pharmacological inhibitor of hChk1.
PMID- 10786671
TI - Expression of the hTERT gene is regulated at the level of transcriptional
initiation and repressed by Mad1.
AB - Telomerase, an enzymatic activity responsible for the replication of chromosome
end structures, is strongly upregulated in most human cancers. In contrast, most
differentiated tissues are telomerase negative. The rate-limiting step for
telomerase activity seems to be the expression of the catalytic subunit of the
enzyme, encoded by the human telomerase reverse transcriptase (hTERT) gene. The
precise mechanism of how hTERT is regulated has not been elucidated yet. We show
here that the down-regulation of hTERT mRNA during 12-O-tetradecanoylphorbol-13
acetate-induced differentiation of human U937 cells is a consequence of a fast
decrease in the rate of transcription rather than changes in its half-life. The
only transcription factor that has so far been implicated in the regulation of
hTERT expression is the c-Myc oncoprotein. Our analysis shows that another member
of the myc/marx/mad network, mad1, encoding a transcriptional repressor that is
significantly increased by 12-O-tetra-decanoylphorbol-13-acetate treatment,
represses hTERT promoter-driven reporter gene activity in transient transfection
assays. This effect is dependent on the NH2 terminal domain of Madl, which
mediates the association with the transcriptional corepressor mSin3. Our findings
suggest the involvement of an additional transcription factor in the regulation
of hTERT expression and may provide a model for how hTERT activity is controlled
during the differentiation process in human somatic tissues.
PMID- 10786672
TI - Metabolites of 2'-fluoro-2'-deoxy-D-glucose detected by 19F magnetic resonance
spectroscopy in vivo predict response of murine RIF-1 tumors to 5-fluorouracil.
AB - There is a clinical need for early detection of tumor response to therapy. This
study aimed to determine whether metabolites of fluorodeoxyglucose (FDG) detected
in solid mouse tumors in situ by I9F magnetic resonance spectroscopy (19F MRS)
correlated with response to 5-fluorouracil chemotherapy. After injection of FDG
(1.4 mmol/kg i.p.), uptake and metabolism was monitored for 2 h in RIF-1 tumors.
FDG was detectable immediately, and after 10 min, a second broad peak was
detected 5-6 ppm upfield. 19F MRS analysis of cell and tumor extracts in vitro
showed that the upfield peak (> or =15% of the total detectable 19F signal)
consisted of the epimer alpha-fluorodeoxymannose (FDM) and various conjugates.
Mice treated with 5-fluorouracil (130 mg/kg) received, 48 h later, a repeat dose
of FDG. The change in the rate of FDM formation, but not the FDG or total 19F
signal, correlated significantly with the response to 5-fluorouracil (P = 0.032),
suggesting that 19F MRS of FDM metabolism in vivo may be a novel means of
predicting tumor response.
PMID- 10786673
TI - Irradiation of a primary tumor, unlike surgical removal, enhances angiogenesis
suppression at a distal site: potential role of host-tumor interaction.
AB - Changes in distal angiogenesis in response to irradiation of primary tumors are
not known. To this end, PC-3, a human prostate carcinoma, and FSA-II, a murine
fibrosarcoma, were grown in the gastrocnemius muscles of male nude mice. Distal
angiogenesis was measured in gel containing human recombinant basic fibroblast
growth factor placed in the cranial windows of these mice. PC-3-bearing mice
showed inhibition of distal angiogenesis, as compared with non-tumor-bearing
controls. Surgical removal of tumors tended to accelerate distal angiogenesis; in
comparison, after irradiation of the PC-3 primary tumor, rates of angiogenesis in
the cranial window were retarded. Irradiation of the non-tumor-bearing leg or of
non-tumor-bearing animals showed no measurable effect on rate of growth of
vessels in the cranial window. Similar results were found with the FSA-II tumors,
with slowed distal angiogenesis in tumor-bearing animals and further suppression
in animals with irradiated tumors. These results demonstrate that the effect of
irradiation of a primary tumor on angiogenesis at a distal site may differ from
the effect of surgical removal of the primary tumor. Unlike surgery, irradiation
of a tumor may enhance angiogenic suppression at a distal site, and this
difference may involve host-tumor interaction.
PMID- 10786674
TI - Interleukin 6 activates androgen receptor-mediated gene expression through a
signal transducer and activator of transcription 3-dependent pathway in LNCaP
prostate cancer cells.
AB - Interleukin 6 (IL-6) is a cytokine that regulates not only immune and
inflammatory responses but also the growth of some tumors, including prostate
carcinomas. IL-6 signals through Janus kinase, signal transducer and activator of
transcription 3 (STAT3), and mitogen-activated protein kinase and is also able to
induce androgen receptor (AR)-mediated gene activation in prostate cancer, which
is an important process in prostate cancer androgen-independent progression. We
now show that IL-6-induced AR-mediated gene activation requires the activation of
STAT3 by IL-6 in LNCaP prostate cancer cells. In particular, STAT3 associates
with AR in an androgen-independent but IL-6-dependent manner. Inhibition of STAT3
rather than mitogen-activated protein kinase results in inhibition of AR-mediated
gene activation in response to IL-6. These findings not only identify STAT3 as an
important signaling molecule required for IL-6-signaling to induce AR-mediated
gene activation in prostate carcinoma cells but also reveal the importance of
activated STAT3 in human tumor development and progression.
PMID- 10786675
TI - Cdr2, a target antigen of naturally occuring human tumor immunity, is widely
expressed in gynecological tumors.
AB - The paraneoplastic neurological disorders provide perhaps the best known example
of naturally occurring tumor immunity in humans. For example, patients with
paraneoplastic cerebellar degeneration (PCD) appear to suppress the growth of
occult breast or ovarian tumors that express a neuronal antigen termed cdr2. PCD
patients harbor cdr2-specific CTLs in their peripheral blood, and these cells are
likely mediators of the tumor suppression. Whereas cdr2 therefore appears to be
the target of an effective immune response in patients with PCD, the general
relevance to cancer patients has been unclear, due in part to reports indicating
that cdr2 is not expressed in tumors obtained from neurologically normal
patients. We have reexamined this question, and we find that cdr2 is widely
expressed in such tumors, indicating that cdr2 is in fact an important tumor
antigen in the general population of breast and ovarian cancer patients.
PMID- 10786676
TI - WWOX, a novel WW domain-containing protein mapping to human chromosome 16q23.3
24.1, a region frequently affected in breast cancer.
AB - Studies were conducted with the final goal of identifying genes of interest
mapping to the chromosome region 16q23.3-24.1, an area commonly affected by
allelic losses in breast cancer. To this end we generated a detailed physical map
of the genomic region spanning between sequence-tagged site markers D16S518 and
D16S516. To identify candidate genes, we used shotgun genomic sequencing as well
as isolation and analysis of transcripts mapping to the area of interest. We
identified and cloned a novel gene, the genomic structure of which spans the
whole region of interest. We named this gene WWOX because it contains two WW
domains coupled to a region with high homology to the short-chain
dehydrogenase/reductase family of enzymes. The ORF of WWOX is 1245 bp long,
encoding a 414-amino acid protein. This gene is composed of nine exons. We
performed a mutation screening of WWOX exons in a panel of breast cancer lines,
most of which are hemizygous for the 16q genomic region indicated. We found no
evidence of mutations, thus indicating that WWOX is probably not a tumor
suppressor gene. However, we observed that one case of homozygous deletion as
well as two previously described translocation breakpoints map to intronic
regions of this gene. We speculate that WWOX may span the yet uncharacterized
common fragile site FRA16D region. In expression studies we found overexpression
of WWOX in breast cancer cell lines when compared with normal breast cells and
tissues. The highest normal expression of WWOX was observed in hormonally
regulated tissues such as testis, ovary, and prostate. This expression pattern
and the presence of a short-chain dehydrogenase/reductase domain and specific
amino acid features suggest a role for WWOX in steroid metabolism. Interestingly,
the presence of WW domains in the structure of WWOX indicate the likelihood that
this protein physically interacts with other proteins. The unique features of
WWOX and its possible association with cancer processes make it an interesting
target for further investigation.
PMID- 10786677
TI - Expression of proteins coincident with inducible radioprotection in human lung
epithelial cells.
AB - Human lung epithelial cells and many other cell lines are hypersensitive to low
doses of ionizing radiation (<0.2 Gy). However, above a threshold dose of 0.4-0.6
Gy, an induced radioprotective response is triggered that protects cells at
higher radiation doses. At 4 h, when maximal induced radioprotection is seen in
these cells after low-dose priming, the two-dimensional gel protein expression
pattern in 0.5-Gy-exposed cells is subtly altered, with seven proteins being 2-
to 5-fold down-regulated and one being 2-fold up-regulated. They include: (a) the
protein kinase C inhibitor 1, or histidine triad nucleotide-binding motif (HINT)
protein; (b) substrates for protein kinase C activity including the chloride
intracellular channel protein 1; and (c) a cytoskeletal protein degraded during
apoptosis. In addition, a lung cancer-specific protein that binds to both
telomeres and nascent mRNA molecules is down-regulated, as is interleukin 1alpha.
Therefore, at least in human lung epithelial cells, radioprotection may be the
result of signaling pathway switching, which results in the removal of damaged
cells and the preparation for enhanced general transcription in surviving cells
during a period in which cell proliferation is repressed. This combination of
events may be cell-type-specific and may have implications for the protection of
normal lung tissue during unavoidable radiation exposure such as in radiotherapy.
PMID- 10786678
TI - Prognosis of primary testicular seminoma: a report on 57 new cases.
AB - Most urologists perform adjuvant radiation therapy for stage 1 (TxN0M0)
testicular seminoma after orchiectomy, although the majority of patients with
clinical stage 1 seminoma do not have occult metastases and therefore do not
require elective nodal irradiation. However, there are currently no clinical or
histological parameters that can be used to distinguish patients who need
radiation therapy from those who do not. We reported previously that estimates of
volume-weighted mean nuclear volume (MNV) were a better predictor of the
prognosis of prostate cancer and renal cell carcinoma than subjective
histological grading. Here, we examined the usefulness of estimation of MNV for
predicting the prognosis of primary testicular seminoma. A retrospective study of
57 patients with testicular seminoma diagnosed between April 1981 and March 1997
at Kobe City General Hospital was performed. Unbiased estimates of MNV data were
compared for prognostic value with the level of beta-human chorionic gonadotropin
(beta-HCG), alpha-fetoprotein (AFP), alkaline phosphatase (ALP), and lactate
dehydrogenase (LDH). Fifty patients were stage 1 (TxNoMo), and 7 patients were
stage 2 (TxN1-2M0). All patients received orchiectomy, followed by radiation
therapy. Estimates of MNV of stage 2 patients were significantly larger than that
of stage 1 patients (P = 0.0142). Although the LDH level was also significantly
higher in stage 2 (P = 0.001), there were no significant differences between
stages 1 and 2 with respect to beta-HCG (P = 0.997), ALP (P = 0.226), and AFP (P
= 0.467). Multivariate logistic regression analysis revealed that the estimate of
MNV was the only variable predicting lymph node metastasis (P = 0.0315). In stage
1 patients, only the estimate of MNV was significantly correlated with
progression-free survival (P = 0.0118). These findings indicate that the estimate
of MNV may be an important prognostic indicator for testicular seminoma.
Estimates of MNV may also be useful for excluding patients from surveillance
protocols.
PMID- 10786679
TI - Complete sequencing of TP53 predicts poor response to systemic therapy of
advanced breast cancer.
AB - TP53 has been implicated in regulation of the cell cycle, DNA repair, and
apoptosis. We studied, in primary breast tumors through direct cDNA sequencing of
exons 2-11, whether TP53 gene mutations can predict response in patients with
advanced disease to either first-line tamoxifen therapy (202 patients, of whom
55% responded) or up-front (poly)chemotherapy (41 patients, of whom 46%
responded). TP53 mutations were detected in 90 of 243 (37%) tumors, and one
fourth of these mutations resulted in a premature termination of the protein. The
mutations were observed in 32% (65 of 202) of the primary tumors of tamoxifen
treated patients and in 61% (25 of 41) of the primary tumors of the chemotherapy
patients. TP53 mutation was significantly associated with a poor response to
tamoxifen [31% versus 66%; odds ratio (OR), 0.22; 95% confidence interval (CI),
0.12-0.42; P < 0.0001]. Patients with TP53 gene mutations in codons that directly
contact DNA or with mutations in the zinc-binding domain loop L3 showed the
lowest response to tamoxifen (18% and 15% response rates, respectively). TP53
mutations were related, although not significantly, to a poor response to up
front chemotherapy (36% versus 63%; OR, 0.34; 95% CI, 0.09-1.24). In multivariate
analysis for response including the classical parameters age and menopausal
status, disease-free interval, dominant site of relapse, and levels of estrogen
receptor and progesterone receptor, TP53 mutation was a significant predictor of
poor response in the tamoxifen-treated group (OR, 0.29; 95% CI, 0.13-0.63; P =
0.0014). TP53-mutated and estrogen receptor-negative (<10 fmol/mg protein) tumors
appeared to be the most resistant phenotype. Interestingly, the response of
patients with TP53 mutations to chemotherapy after tamoxifen was not worse than
that of patients without these mutations (50% versus 42%; OR, 1.35,
nonsignificant). The median progression-free survival after systemic treatment
was shorter for patients with a TP53 mutation than for patients with wild-type
TP53 (6.6 and 0.6 months less for tamoxifen and up-front chemotherapy,
respectively). In conclusion, TP53 gene mutation of the primary tumor is helpful
in predicting the response of patients with metastatic breast disease to
tamoxifen therapy. The type of mutation and its biological function should be
considered in the analyses of the predictive value of TP53.
PMID- 10786680
TI - Cytochrome c is involved in Fas-mediated apoptosis of prostatic carcinoma cell
lines.
AB - We have shown previously that the pathways leading to Fas-mediated apoptosis in
prostatic carcinoma cell lines are intact, because apoptosis can be triggered
either by Fas ligation alone in the Fas-sensitive cell lines PC3 and ALVA31 or by
rendering the Fas-resistant cell lines DU145 and JCA1 Fas-sensitive by combined
treatment with anti-Fas monoclonal antibody and cycloheximide (O. W. Rokhlin et
al., Cancer Res., 57: 1758-1768, 1997). In this study, we demonstrate that two of
the early events after Fas ligation are the release of cytochrome c from the
mitochondria and activation of caspase-9. We also found that Bid is processed
after Fas ligation and thus might activate the mitochondria-dependent apoptotic
cascade. In a cell-free system, cytochrome c induced caspase-3-like activity in
cytoplasmic extracts from all four cell lines studied, although differences in
the level of enzymatic activity were observed. Western blot analysis revealed
that caspase-7 is activated by cytochrome c at the same level in all extracts,
whereas expression and activation of caspase-3 varied considerably. Cytochrome c
activated extracts displayed different abilities in the induction of apoptotic
features in isolated nuclei such as morphological changes and DNA fragmentation.
However, differences in nuclear apoptotic activity induced by cytochrome c did
not correlate with the level of caspase-3 like activity in the different
extracts. These results suggest that the mitochondrial pathway is involved in Fas
mediated apoptosis in prostatic carcinoma cell lines and that, in addition to
caspase-7 and caspase-3, there are other factors that confer nuclear apoptotic
activity.
PMID- 10786681
TI - Suppression of tumor angiogenesis and growth by gene transfer of a soluble form
of vascular endothelial growth factor receptor into a remote organ.
AB - Antiangiogenic therapy shows promise as a strategy for cancer treatment. We
constructed an adenovirus (AdVEGF-ExR) expressing the entire extracellular domain
of the human vascular endothelial growth factor (VEGF) receptor (flt-1) fused to
the Fc portion of human IgG. The soluble receptor secreted from AdVEGF-ExR
infected cells bound to VEGF and inhibited VEGF-induced DNA synthesis in
endothelial cells. When human lung cancer cell line H157, which produces not only
VEGF but also fibroblast growth factor 2 and interleukin 8 at substantial levels,
was infected with AdVEGF-ExR, cell growth in vitro was not affected. However,
when H157 cells infected with AdVEGF-ExR were injected s.c. into nude mice, tumor
formation stopped on the 10th day after reaching a certain size (about 100 mm3),
and tumor size declined gradually thereafter. When AdVEGF-ExR was injected into
skeletal muscle and uninfected H157 cells were injected s.c., the soluble
receptor was detectable in the circulating blood for 3 weeks, tumor growth ceased
after 10 days, and tumor size declined thereafter. Histological examination
revealed that intratumor angiogenesis was markedly suppressed, and apoptosis was
enhanced. Using the same experimental protocol, a significant suppression of
tumor growth was also seen in four of five other lung cancer cell lines, some of
which secreted VEGF at nominal levels, at least under normoxic conditions in
vitro. Our results demonstrate that adenovirus-mediated expression of a soluble
VEGF receptor in a remote organ could inhibit tumor angiogenesis and enhance
apoptosis and thereby suppress tumor growth in vivo. Adenovirus-mediated
overexpression of a soluble VEGF receptor in a remote organ may have the
potential to be a feasible and effective strategy for cancer treatment.
PMID- 10786682
TI - PTK787/ZK 222584, a novel and potent inhibitor of vascular endothelial growth
factor receptor tyrosine kinases, impairs vascular endothelial growth factor
induced responses and tumor growth after oral administration.
AB - PTK787/ZK 222584 (1-[4-chloroanilino]-4-[4-pyridylmethyl] phthalazine succinate)
is a potent inhibitor of vascular endothelial growth factor (VEGF) receptor
tyrosine kinases, active in the submicromolar range. It also inhibits other class
III kinases, such as the platelet-derived growth factor (PDGF) receptor beta
tyrosine kinase, c-Kit, and c-Fms, but at higher concentrations. It is not active
against kinases from other receptor families, such as epidermal growth factor
receptor, fibroblast growth factor receptor-1, c-Met, and Tie-2, or intracellular
kinases such as c-Src, c-Abl, and protein kinase C-alpha. PTK787/ZK 222584
inhibits VEGF-induced autophosphorylation of kinase insert domain-containing
receptor (KDR), endothelial cell proliferation, migration, and survival in the
nanomolar range in cell-based assays. In concentrations up to 1 microM, PTK787/ZK
222584 does not have any cytotoxic or antiproliferative effect on cells that do
not express VEGF receptors. After oral dosing (50 mg/kg) to mice, plasma
concentrations of PTK787/ZK 222584 remain above 1 microM for more than 8 h.
PTK787/ZK 222584 induces dose-dependent inhibition of VEGF and PDGF-induced
angiogenesis in a growth factor implant model, as well as a tumor cell-driven
angiogenesis model after once-daily oral dosing (25-100 mg/kg). In the same dose
range, it also inhibits the growth of several human carcinomas, grown s.c. in
nude mice, as well as a murine renal carcinoma and its metastases in a syngeneic,
orthotopic model. Histological examination of tumors revealed inhibition of
microvessel formation in the interior of the tumor. PTK787/ZK 222584 is very well
tolerated and does not impair wound healing. It also does not have any
significant effects on circulating blood cells or bone marrow leukocytes as a
single agent or impair hematopoetic recovery after concomitant cytotoxic anti
cancer agent challenge. This novel compound has therapeutic potential for the
treatment of solid tumors and other diseases where angiogenesis plays an
important role.
PMID- 10786683
TI - Synergy between angiostatin and endostatin: inhibition of ovarian cancer growth.
AB - Ovarian cancer is the leading cause of fatality among gynecological malignancies.
Ovarian cancer growth is angiogenesis-dependent, and an increased production of
angiogenic growth factors such as vascular endothelial growth factor is
prognostically significant even during early stages of the disease. Therefore, we
investigated whether antiangiogenic treatment can be used to inhibit the growth
of ovarian cancer in an experimental model system. Mouse angiostatin (kringle 1
4) and endostatin were expressed in yeast. Purified angiostatin and endostatin
were then used to treat established ovarian cancers in athymic mice. These
studies showed that both angiostatin and endostatin inhibited tumor growth.
However, angiostatin treatment was more effective in inhibiting ovarian cancer
growth when compared with endostatin in parallel experiments. Residual tumors
obtained from angiostatin- and endostatin-treated animals showed decreased number
of blood vessels and, as a consequence, increased apoptosis of tumor cells.
Subsequently, the efficacy of a combined treatment with angiostatin and
endostatin was investigated. In the presence of both angiostatic proteins,
endothelial cell proliferation was synergistically inhibited. Similarly, a
combination regimen using equal amounts of angiostatin and endostatin showed more
than additive effect in tumor growth inhibition when compared with treatment with
individual angiostatic protein. These studies demonstrate synergism between two
angiostatic molecules and that antiangiogenic therapy can be used to inhibit
ovarian cancer growth.
PMID- 10786684
TI - Epidermal growth factor-mediated targeting of chlorin e6 selectively potentiates
its photodynamic activity.
AB - Certain tumor cells, such as squamous carcinoma cells, express an increased
number of epidermal growth factor (EGF) receptors. Therefore, we studied the
targeted delivery of the photocytotoxic compound Sn-(IV)chlorin e6
monoethylenediamine [SnCe6(ED)] to tumors that overexpress the EGF receptor. EGF
was conjugated to SnCe6(ED) through a carrier, such as dextran (Dex) and human
serum albumin (HSA), and the photocytotoxicity on the EGF receptor-overexpressing
MDA-MB-468 breast adenocarcinoma cell line was evaluated. The photobiological
activities of these EGF conjugates, of the conjugates of the photosensitizer to
HSA or Dex, or of the photosensitizer alone were compared. The affinity of EGF
for its receptor was substantially impaired when conjugated in EGF-Dex-SnCe6(ED),
in contrast to EGF-HSA-SnCe6(ED). In corresponding results, EGF-HSA-SnCe6(ED)
displayed a high photocytotoxicity (IC50, 63 nM) on MDA-MB-468 cells at a light
dose of 27 kJ/m2, whereas EGF-Dex-SnCe6(ED) showed very limited
photocytotoxicity. EGF-HSA-SnCe6(ED) was no longer photocytotoxic in the presence
of a competing EGF concentration. The high photocytotoxicity of EGF-HSA-SnCe6(ED)
was shown to be the result of a high intracellular concentration in MDA-MB-468
cells, which could be lowered dramatically by incubating the conjugate with a
competing EGF concentration. In contrast, EGF-Dex-SnCe6(ED) accumulated poorly in
MDA-MB-468 cells, in agreement with its low EGF receptor affinity and
photocytotoxicity. EGF-HSA-SnCe6(ED) produced much more intracellular reactive
oxygen species on light irradiation than EGF-Dex-SnCe6(ED). It is concluded that
the photodynamic activity of the EGF-HSA conjugate of SnCe6(ED) on MDA-MB-468
breast adenocarcinoma cells is EGF specific and is much more potent than EGF-Dex
SnCe6(ED) or free SnCe6.
PMID- 10786685
TI - E-7869 (R-flurbiprofen) inhibits progression of prostate cancer in the TRAMP
mouse.
AB - E-7869 (R-flurbiprofen) is a single enantiomer of a racemic nonsteroidal anti
inflammatory drug. E-7869 does not inhibit either cyclooxygenase-1 or
cyclooxygenase-2. We used the transgenic adenocarcinoma mouse prostate (TRAMP)
mouse, a prostate cancer model, to evaluate the effect of this drug on prostate
cancer progression. Sixty 12-week-old male TRAMP mice were placed randomly into
five groups. The animals were treated by daily oral gavage with vehicle (1%
carboxymethylcellulose) or E-7869 for 18-weeks. During the course of the study,
two diets were used. Three groups (vehicle, 15-mg/kg, and 20-mg/kg drug
treatments) received a Teklad diet containing 2.4% saturated fat [a high
saturated fat (HSF) diet], and two groups (vehicle and 20 mg/kg drug treatment)
received an AIN-93G diet containing 1.05% saturated fat [a low saturated fat
(LSF) diet]. At necropsy, the urogenital system and periaortic lymph nodes were
removed and weighed. The prostate lobes, seminal vesicles, lungs, and periaortic
lymph nodes were preserved and sectioned for histological evaluation. The lung
and periaortic lymph nodes were graded as to the presence (+) or absence (-) of
metastasis; the urogenital tissues were graded on a 1-6 scale for degree of
neoplasia/carcinoma. For both diets, the urogenital wet weights and lymph node
wet weights in the 20-mg/kg treatment groups were significantly lower as compared
to vehicle control groups. In addition, treatment with 20 mg/kg E-7869 in the LSF
diet group resulted in a significantly lower primary tumor incidence (P < 0.05)
and reduced incidence of metastasis. In this treatment group, the reduced
incidence of metastasis was not statistically significant because the LSF diet
itself resulted in a remarkably lower incidence of metastasis in the vehicle
control group (10% LSF versus 40% HSF). Treatment with 20 mg/kg E-7869 on the HSF
diet resulted in a significantly lower incidence of metastasis (P < 0.05) and a
reduction in the primary tumor incidence. These results suggest that E-7869 is a
promising chemopreventive and treatment for human prostate cancer.
PMID- 10786686
TI - CC chemokine receptor-7 on dendritic cells is induced after interaction with
apoptotic tumor cells: critical role in migration from the tumor site to draining
lymph nodes.
AB - Dendritic cells (DCs) are very potent antigen-presenting cells and play critical
roles in regulating immune responses in cancer. The migrating of DCs from the
tumor site to the lymphoid organs is believed to be one of the critical events.
To examine this important DC function in tumor situations, bone marrow-derived
DCs, cultured for 6 days with granulocyte macrophage colony-stimulating factor
and interleukin 4, were inoculated at the tumor site. We have shown (Y. Nishioka
et al., Cancer Res., 59: 40354041, 1999) that DCs can migrate from tumor site to
the draining lymph nodes within 24 h (approximately 0.1% of administrated DCs).
The DCs then form clusters with adjacent lymphoid cells, which produce IFN-gamma
(1500-3200pg/10(6) cells/48 h) in response to tumor stimulation. The number of
the DCs migrating into lymph nodes were greater when they were inoculated into
the tumor rather than the skin. Coculture of DCs and apoptotic tumor cells
resulted in decreased expression of CC chemokine receptor (CCR) 1 and increased
CCR7 expression at mRNA level without alteration in other phenotypical markers on
DCs. Chemotaxis assay showed that CCR7 ligands, macrophage inflammatory protein
3beta and secondary lymphoid-tissue chemokine significantly (P < 0.05) induced
the migration of DCs when cocultured with apoptotic tumor cells. To directly
examine the involvement of CCR7 expression in DC migration, we investigated the
functions of DCs genetically modified to express high levels of CCR7. CCR7
transduction promotes DC migration in response to relevant ligands in vitro and
in vivo. These results suggest that the CCR7 expression of DCs is enhanced with
direct contact with apoptotic tumor cells and may have a critical role for DC
migrating to regional lymph nodes. The means to promote DC delivery to tumor and
to nodal sites represent novel targets for the biological therapy of cancer.
PMID- 10786687
TI - Immune deviation and Fas-mediated deletion limit antitumor activity after
multiple dendritic cell vaccinations in mice.
AB - Genetic immunization with a single injection of dendritic cells (DCs) expressing
a model melanoma antigen generates antigen-specific, MHC-restricted, protective
immune responses. After initiating the immune response, additional vaccinations
may increase the protection or conversely downregulate the immune response.
Groups of mice were vaccinated several times with DCs transduced with the MART-1
gene, and the anti-tumor protection was compared with that of mice receiving a
single vaccination. C3H mice had poorer protection from a syngeneic MART-1
expressing tumor challenge with multiple vaccinations. This was accompanied by
lower levels of splenic CTL effectors and a shift from a type 1 to a type 2
cytokine profile. On the contrary, multiple vaccinations in C57BL/6 mice
generated greater in vivo antitumor protection with no decrease in splenic CTLs
and no cytokine shift. Antiadenoviral humoral or cellular immune responses did
not seem to contribute to these effects. When studies were performed in Fas
receptor-negative C3H.(lpr) mice, the adverse effect of multiple vaccinations
disappeared, and there was no cytokine shift pattern. In conclusion, C3H mice but
not C57BL/6 mice receiving multiple vaccinations with DCs expressing the MART-1
tumor antigen show decreased protection associated with deviation from a type 1
to a type 2 cytokine response attributable to a Fas-receptor mediated clearance
of antigen-specific IFN-gamma-producing cells.
PMID- 10786688
TI - HMSH6 alterations in patients with microsatellite instability-low colorectal
cancer.
AB - Two microsatellite instability (MSI) phenotypes have been described in colorectal
cancer (CRC): MSI-H (instability at >30% of the loci examined) and MSI-L (MSI at
1-30% of the loci examined). The MSI-H phenotype, observed in both hereditary
nonpolyposis colon cancer-associated CRC and approximately 15% of sporadic CRC,
generally results from mutational or epigenetic inactivation of the DNA mismatch
repair (MMR) genes hMSH2 or hMLH1. The genetic basis for the MSI-L phenotype,
however, is unknown. Several other proteins, including hMSH3 and hMSH6, also
participate in DNA MMR. Inactivating mutations of MSH6 in yeast and human tumor
cell lines are associated with an impaired ability to repair single-base mispairs
and small insertion-deletion loops but not large insertion-deletion loops. This
suggests that hMSH6 mutations are more likely to be associated with a MSI-L
phenotype than a MSI-H phenotype in CRC. To explore this possibility, we screened
tumors from 41 patients with MSI-L CRC for hMSH6 mutations with conformation
sensitive gel electrophoresis (CSGE) and for hMSH6 protein expression by
immunohistochemistry. Alterations found with CSGE were confirmed by DNA
sequencing of normal and tumor tissue. One somatic (Asp389Asn) and 15 germ-line
changes were found. Of the 15 germ-line changes, 9 were found in an intron (none
involving splice junctions), and 6 were found in an exon (Gly39Glu, Leu395Val,
and 4 silent alterations). Immunohistochemical staining for hMSH6 performed on 34
of the 41 tumors revealed strong nuclear hMSH6 expression in all of the cases.
Overall, our results suggest that hMSH6 mutations do not play a major role in the
development of sporadic CRC with a MSI-L phenotype.
PMID- 10786689
TI - Linking gene expression patterns to therapeutic groups in breast cancer.
AB - A major objective of current cancer research is to develop a detailed molecular
characterization of tumor cells and tissues that is linked to clinical
information. Toward this end, we have identified approximately one-quarter of all
genes that were aberrantly expressed in a breast cancer cell line using
differential display. The cancer cells lost the expression of many genes involved
in cell adhesion, communication, and maintenance of cell shape, while they gained
the expression of many synthetic and metabolic enzymes important for cell
proliferation. High-density, membrane-based hybridization arrays were used to
study mRNA expression patterns of these genes in cultured cells and archived
tumor tissue. Cluster analysis was then used to identify groups of genes, the
expression patterns of which correlated with clinical information. Two clusters
of genes, represented by p53 and maspin, had expression patterns that strongly
associated with estrogen receptor status. A third cluster that included HSP-90
tended to be associated with clinical tumor stage, whereas a forth cluster that
included keratin 14 tended to be associated with tumor size. Expression levels of
these clinically relevant gene clusters allowed breast tumors to be grouped into
distinct categories. Gene expression fingerprints that include these four gene
clusters have the potential to improve prognostic accuracy and therapeutic
outcomes for breast cancer patients.
PMID- 10786691
TI - Ubiquitin/proteasome pathway regulates levels of retinoic acid receptor gamma and
retinoid X receptor alpha in human keratinocytes.
AB - Repeated exposure of human skin to solar UV radiation leads to premature aging
(photoaging) and skin cancer. UV-induced skin damage can be ameliorated by all
trans retinoic acid treatment. The actions of retinoic acid in skin keratinocytes
are mediated primarily by nuclear retinoic acid receptor gamma (RARgamma) and
retinoid X receptor alpha (RXRalpha). We found that exposure of cultured primary
human keratinocytes to UV irradiation (30 mJ/cm2) substantially reduced (50-90%)
RARgamma and RXRalpha mRNA and protein within 8 h. The rates of disappearance of
RARgamma and RXRalpha proteins after UV exposure or treatment with the protein
synthesis inhibitor cycloheximide were similar. UV irradiation did not increase
the rate of breakdown of RARgamma or RXRalpha but rather reduced their rate of
synthesis. The addition of proteasome inhibitors MG132 and LLvL, but not the
lysosomal inhibitor E64, prevented loss of RARgamma and RXRalpha proteins after
exposure of keratinocytes to either UV radiation or cycloheximide. Soluble
extracts from nonirradiated or UV-irradiated keratinocytes possessed similar
levels of proteasome activity that degraded RARgamma and RXRalpha proteins in
vitro. Furthermore, RARgamma and RXRalpha were polyubiquitinated in intact cells.
RXRalpha was found to contain two proline, glutamate/aspartate, serine, and
threonine (PEST) motifs, which confer rapid turnover of many short-lived
regulatory proteins that are degraded by the ubiquitin/proteasome pathway.
However, the PEST motifs in RXRalpha did not function to regulate its stability,
because deletion of the PEST motifs individually or together did not alter
ubiquitination or proteasome-mediated degradation of RXRalpha. These results
demonstrate that loss of RARgamma and RXRalpha proteins after UV irradiation
results from degradation via the ubiquitin/proteasome pathway. Taken together,
the data here indicate that ubiquitin/proteasome-mediated breakdown is an
important mechanism regulating the levels of nuclear retinoid receptors.
PMID- 10786690
TI - The normal patched allele is expressed in medulloblastomas from mice with
heterozygous germ-line mutation of patched.
AB - Defects in a developmental signaling pathway involving mammalian homologues of
the Drosophila segment polarity gene, patched (ptc) and its ligand, sonic
hedgehog (shh), contribute to tumor formation in several tissues. Recently, a
subset of medulloblastoma, the most common malignant brain tumor in children, was
found to contain somatic mutations in the human ptc gene. In addition, basal cell
nevus syndrome (BCNS), or Gorlin syndrome, which is characterized by
developmental anomalies and a predisposition to skin and nervous system
malignancies, is associated with germ-line mutation of ptc. Targeted disruption
of both alleles of ptc in mice results in embryonic lethality. However, ptc+/-
mice survive and develop spontaneous cerebellar brain tumors, suggesting that ptc
may function as a tumor suppressor gene. Therefore, we investigated ptc+/-mice as
a model for human medulloblastoma. We report that 14% of ptc+/- mice develop
central nervous system tumors in the posterior fossa by 10 months of age, with
peak tumor incidence occurring between 16 and 24 weeks of age. The tumors
exhibited several characteristics of human medulloblastoma, including expression
of intermediate filament proteins specific for neurons and glia. Full-length ptc
mRNA was present in all tumors analyzed, indicating that there was no loss of
heterozygosity at the ptc locus. Nucleotide sequence of ptc mRNA from four tumors
failed to identify any mutations. However, a comparison of the normal ptc
sequence from C57BL/6 and 129Sv mice did reveal several polymorphisms. High
levels of glil mRNA and protein were detected in the tumors, suggesting that the
shh/ptc pathway was activated despite the persistence of ptc expression. These
data indicate that haploinsufficiency of ptc is sufficient to promote oncogenesis
in the central nervous system.
PMID- 10786692
TI - Molecular markers in blood as surrogate prognostic indicators of melanoma
recurrence.
AB - Improvement is needed in the ability to evaluate the prognosis of melanoma
patients who are clinically disease-free but likely to develop recurrent
metastatic disease. The detection of circulating melanoma cells in blood is a
potential surrogate marker of subclinical residual disease. We assessed the
prognostic clinical utility of a multimarker melanoma reverse transcriptase-PCR
(RT-PCR) assay using blood of 46 patients who were clinically disease-free. All
patients were followed up for more than 4 years for disease recurrence. There was
a significant correlation between number of RT-PCR markers present in blood and
American Joint Committee on Cancer stage (P = 0.009). The number of RT-PCR
markers detected in blood was an independent prediction factor of disease
recurrence in a Cox proportional hazard model (P = 0.02). A risk factor model
using American Joint Committee on Cancer stage and number of positive RT-PCR
markers significantly predicted disease recurrence in 2, 3, and 4 years of follow
up. These studies demonstrate that molecular detection of circulating melanoma
cells may be of significant prognostic value in determining early disease
recurrence and may be useful for stratifying patients for adjuvant therapy.
PMID- 10786693
TI - Dihydrotestosterone as a selective cellular/nuclear localization vector for anti
gene peptide nucleic acid in prostatic carcinoma cells.
AB - Peptide nucleic acids (PNAs) are synthetic structural analogues of DNA and RNA
that, if allowed to enter the cell, bind to the complementary polynucleotide
sequence and inhibit DNA transcription and mRNA translation. Although PNAs have a
very limited ability in penetrating nuclei of living cells, there are indications
that covalent linkage of the PNA to appropriate vectors, e.g., a nuclear
localization signal, permits access to the genome. Here we test the ability of
dihydrotestosterone (T) covalently linked to PNA to act as a vector for targeting
c-myc DNA to prostatic cancer cell nuclei. LNCaP cells, which express the
androgen receptor gene, and DU145 cells, in which the androgen receptor gene is
silent, offer a model to test this biologically active hormone as a cell-specific
vector. T vector was covalently linked to the NH2-terminal position of a PNA
complementary to a unique sequence of c-myc oncogene (PNAmyc-T). To localize
PNAmyc-T and vector-free PNA within the cells, a rhodamine (R) group was attached
at the COOH-terminal position (PNAmyc-R, PNAmyc-TR); cellular uptake was
monitored by confocal fluorescence microscopy. PNAmyc-R was detected only in the
cytoplasm of both prostatic cell lines, whereas PNAmyc-TR was localized in nuclei
as well as in cytoplasm of LNCaP cells. In contrast, PNAmyc-TR uptake in DU145
cells was minimal and exclusively cytoplasmic. In LNCaP cells, MYC protein
remained unchanged by exposure to vector-free PNAmyc, whereas a significant and
persistent decrease was induced by PNAmyc-T. In DU145 cells, MYC expression was
unaltered by PNAmyc with or without the T vector. Our data show that the T vector
facilitates cell-selective nuclear localization of PNA and its consequent
inhibition of c-myc expression. These findings suggest a strategy for targeting
of cell-specific anti-gene therapy in prostatic carcinoma.
PMID- 10786694
TI - Insulin-like growth factor I receptor signaling in differentiation of neuronal
H19-7 cells.
AB - The type I insulin-like growth factor receptor (IGF-IR) is known to send two
seemingly contradictory signals inducing either cell proliferation or cell
differentiation, depending on cell type and/or conditions. H19-7 cells are rat
hippocampal neuronal cells immortalized by a temperature-sensitive SV40 large T
antigen that grow at 34 degrees C in epidermal growth factor or serum but
differentiate at 39 degrees C when induced by basic fibroblast growth factor. At
39 degrees C, expression of the human IGF-IR in H19-7 cells induces an insulin
like growth factor (IGF) I-dependent differentiation. We have investigated the
domains of the IGF-IR required for differentiation of H19-7 cells. The tyrosine
950 residue and serines 1280-1283 in the COOH terminus of the receptor are
required for IGF-I-induced differentiation at 39 degrees C, although they are
dispensable for IGF-I-mediated growth at 34 degrees C. Both domains have to be
mutated to inactivate the differentiating function. The inability of these mutant
receptors to induce differentiation correlates with mitogen-activated protein
kinase activation. In contrast, inhibitors of phosphatidylinositol 3'-kinase have
no effect on IGF-I-mediated differentiation of H19-7 cells, although they do
inhibit the mitogenic response.
PMID- 10786696
TI - Thioredoxin reductase, a redox-active selenoprotein, is secreted by normal and
neoplastic cells: presence in human plasma.
AB - Thioredoxin (Trx) and Trx reductase (TrxR) are redox-active proteins that
participate in multiple cellular events, including growth promotion, apoptosis,
and cytoprotection. Studies on overexpression of Trx and TrxR in human cancers
have indicated a role of these proteins in tumor development. In this study, we
analyzed the expression of TrxR in peripheral blood cells, tumor-transformed
leukemia, and melanoma cells and found, in addition to abundant plasma membrane
localization, that TrxR was released from these cells. Secretory cells were
observed at the single cell level using a sensitive enzyme-linked immunospot
assay. The release was inducible, and physiological stimulation of human
monocytes by IFN-gamma, lipopolysaccharide, and interleukin 1alpha significantly
increased the number of TrxR-secreting cells (P = 0.004). Secretion of TrxR
followed the classical Golgi pathway, and it was confirmed by metabolic labeling
using [35S]methionine and [35S]cysteine. TrxR was also detected for the first
time in fresh healthy blood donor plasma (n = 21; median concentration, 18.0
ng/ml), with biological activity as determined by insulin reduction assay. These
results highlight the role of extracellular Trx and TrxR during inflammation and
tumor progression. Released Trx, with its active site motif containing amino
acids Cys-X-X-Cys, was recently shown to have chemoattractant properties beside
its previously described antioxidant and cocytokine activities. Regeneration of
oxidized Trx requires available TrxR outside the cell, the presence and induction
of which is described in this paper for normal and transformed cells.
PMID- 10786695
TI - Enhanced sensitivity to anti-benzo(a)pyrene-diol-epoxide DNA damage correlates
with decreased global genomic repair attributable to abrogated p53 function in
human cells.
AB - DNA damage from exposure to environmental chemical carcinogens and failure of
repair systems to eliminate these lesions from the genome are considered as the
crucial initial steps in the development of various human malignancies. Many
cellular proteins are known to play vital roles to overcome the effects of DNA
damage. Among such proteins, p53 is known to respond to DNA damage by
accumulating in the nucleus and inhibiting cell cycle progression to facilitate
DNA repair and the maintenance of genomic stability. In this study, we have
investigated the role of p53 protein in modulating nucleotide excision repair of
anti-benzo-(a)pyrene-diol-epoxide (BPDE)-DNA adducts and related effects using
human fibroblasts with normal (p53-WT) and altered p53 protein (p53Mut and p53
Null). Interestingly, irrespective of the presence or absence of p53, the anti
BPDE dose-dependent p21 protein induction response was qualitatively comparable
in all of the three cell lines. However, cells with defective p53 function were
deficient for the removal of anti-BPDE-DNA adducts from the overall genome
compared to cells with wild-type p53 activity. Strand-specific repair analysis
within the individual strands of the p53 gene revealed decreased repair of
adducts from the nontranscribed strand in p53-Mut and p53-Null cells. However,
the repair of the transcribed strand appeared to be identical in all of the three
cell lines. Furthermore, p53-Mut and p53-Null cells were more sensitive than p53
WT cells and displayed increased levels of anti-BPDE-induced apoptosis. Thus,
wild-type p53 is required for the efficient global genomic repair of anti-BPDE
induced DNA adducts from the overall genome, but not for transcription-coupled
repair of actively transcribed genes. These findings indicate that inefficient
DNA repair of potentially cytotoxic and mutagenic lesions from the nontranscribed
strand due to the loss of p53, but not the loss of p21, function might be
responsible for enhanced cytotoxicity and apoptosis in human cells upon DNA
damage.
PMID- 10786697
TI - Interleukin 8 expression regulates tumorigenicity and metastasis in human bladder
cancer.
AB - Interleukin 8 (IL-8) is mitogenic and chemotactic for endothelial cells. Within a
neoplasm, IL-8 is secreted by inflammatory and neoplastic cells. The highly
tumorigenic and highly metastatic human transitional cell carcinoma (TCC) cell
line 253J B-V overexpresses IL-8 relative to the nontumorigenic and nometastatic
253J-P cell line. To determine whether IL-8 expression regulates tumorigenicity
and metastasis in human TCC, 253J B-V cells were transfected with the full
sequence antisense (AS) cDNA for IL-8, whereas 253J-P cells were transfected with
the full-length IL-8 cDNA, and control cells for each were transfected with the
neomycin resistance (Neo) gene. In vitro, sense-transfected 253J-P cells
overexpressed IL-8-specific mRNA and protein, whereas both of these were markedly
reduced in AS-IL-8-transfected 253J B-V cells relative to controls. Moreover,
sense-transfected cells showed up-regulation in matrix metalloproteinase type 9
mRNA, collagenase activity, and increased invasiveness through Matrigel-coated
filters, whereas these measures were lower in AS-transfected cells relative to
controls. After implantation into the bladders of athymic nude mice, the sense
transfected 253J-P cells acquired increased tumorigenicity and metastasis,
whereas the AS-transfected cells significantly inhibited tumorigenicity and
metastases in the 253J B-V cell lines. This effect was accompanied by reduced IL
8 expression and microvessel density. These studies demonstrate that IL-8
expression enhances angiogenic activity through the induction of matrix
metalloproteinase type 9 and subsequently regulates the tumorigenesis and
production of spontaneous metastases of human TCC.
PMID- 10786698
TI - Human glioblastoma cell lines: levels of low-density lipoprotein receptor and low
density lipoprotein receptor-related protein.
AB - The status of the low-density lipoprotein (LDL) receptor and LDL receptor-related
protein (LRP) in seven human glioma cell lines was evaluated to extend our
knowledge of human glioblastoma multiforme tumor metabolism for future drug
design. Cell lines SF-767, SF-763, A-172, U-87 MG, U-251 MG, U-343 MG, and SF-539
were used. Binding of 125I-labeled LDL to these cells at 4 degrees C was carried
out to determine the number of LDL receptors on cells and the affinity of LDL for
these receptors. The content of LRP was measured by immunoblotting. The presence
of specific saturable LDL receptors was proven in six of the cell lines
investigated. SF-767 cells revealed high-affinity LDL binding (equilibrium
dissociation constant, Kd = 7 nM) and maximum binding capacity approximating
300,000 receptors/cell. Most of the remaining cell lines had relatively lower
affinity (Kd = 38-62 nM) but also had very high numbers of receptors (128,000
950,000/cell). All cell lines exhibited LRP, but the expression was variable. The
cell lines SF-539, U-87 MG, and U-343 MG were particularly rich in this protein.
The data suggest that glioblastoma cells have high numbers of LDL receptors;
however, there is considerable variation in binding affinity. Overall, this
finding suggests that LDL receptors on glioblastoma cells could potentially be
useful for targeting antitumor agents. LRP, a multifunctional receptor expressed
on glioblastoma cells, also has the possibility for serving as a therapeutic
target.
PMID- 10786699
TI - Apoptosis is induced by the active metabolite of vitamin D3 and its analogue
EB1089 in colorectal adenoma and carcinoma cells: possible implications for
prevention and therapy.
AB - Vitamin D3 is believed to reduce the risk of colon cancer, and serum levels
inversely correlate with colorectal cancer incidence. The active metabolite,
1alpha,25-dihydroxyvitamin D3, has previously been shown to inhibit growth and
promote differentiation of colon cancer cells. The vitamin D analogue, EB1089, is
currently under clinical trial in a variety of cancers because of its growth
inhibitory effects in vitro and reduced hypercalcemic effects in vivo. The
mechanism of growth inhibition by EB1089, however, remained to be determined. In
this study we examined the effects of alpha,25-dihydroxyvitamin D3 and EB1089 on
five colorectal tumor cell lines (two adenoma and three carcinoma) to determine
the mechanism of growth inhibition and to ascertain whether premalignant adenoma
cells were responsive to these agents. 1alpha,25-Dihydroxyvitamin D3 and EB1089
induced p53-independent apoptosis in adenoma and carcinoma cell lines in a dose
dependent manner between 10(-10) and 10(-6) M. EB1089, as well as inducing
apoptosis, increased the proportion of cells in the G1 phase, particularly in the
adenoma cell lines. In two of the three carcinoma cell lines (SW620 and PC/JW),
levels of apoptosis induced by EB1089 were similar or greater than those induced
by 1alpha,25-dihydroxyvitamin D3. Although the carcinoma cell line HT29 was
relatively resistant to apoptosis induced by EB1089 compared with 1alpha,25
dihydroxyvitamin D3, EB1089 markedly inhibited cell yields. These observations
offer promise for the clinical use of EB1089. To determine whether the induction
of apoptosis by 1alpha,25-dihydroxyvitamin D3 and EB1089 was potentially via a
differentiation pathway, alkaline phosphatase activity was measured as a marker
of differentiation. Induction of alkaline phosphatase was observed in the
floating apoptotic cells as well as in the adherent population. A link between
the induction of differentiation and apoptosis by 1alpha,25-dihydroxyvitamin D3
and EB1089 is suggested by the occurrence of apoptosis subsequent to the
induction of differentiation. To investigate the molecular pathway to apoptosis
induction, members of the Bcl-2 family of proteins were examined (Bcl-2, Bcl-x,
Bax, and Bak). Decreased Bcl-2 was observed in some cell lines, particularly in
response to EB1089, but was not essential for apoptosis. Levels of the
proapoptotic protein Bak, however, were consistently increased in all of the five
cell lines in association with apoptosis induced by either agent. The results
implicate Bak protein in the induction of apoptosis by 1alpha,25-dihydroxyvitamin
D3 or its analogue EB1089. The ability of EB1089 to induce apoptosis in
colorectal carcinoma cells suggests that this or other vitamin D analogues may
prove clinically effective for the treatment of colorectal cancer. Furthermore,
the fact that it induces cell cycle arrest and apoptosis in the premalignant
adenoma cells may suggest an application in colorectal cancer chemoprevention.
PMID- 10786700
TI - Interaction of adenosine and guanine derivatives in the rat hippocampus: effects
on cyclic AMP levels and on the binding of adenosine analogues and GMP.
AB - Guanine nucleotides (GN) have been implicated in many intracellular mechanisms.
Extracellular actions, probably as glutamate receptor antagonists, have also been
recently attributed to these compounds. GN may have a neuroprotective role by
inhibiting excitotoxic events evoked by glutamate. Effects of extracellular GN on
adenosine-evoked cellular responses have also been reported. However, the exact
mechanism of such interaction is not known. In the present study, we showed that
GN potentiated adenosine-induced cAMP accumulation in slices of hippocampus from
young rats. However, neither GMP nor the metabotropic glutamate receptor agonist,
1S,3R-ACPD, inhibited the binding of the adenosine receptor agonist [3H]NECA
(when binding to adenosine A2 receptors), or the binding of the adenosine A2a
receptor agonist [3H]CGS 21680 in hippocampal membrane preparations. GppNHp,
probably by interacting with G-proteins, decreased [3H]CGS 21680 binding. [3H]GMP
binding was assayed in order to evaluate the GN sites which are not G-proteins.
[3H]GMP binding was inhibited by GMP and GppNHp, but not by IS,3R-ACPD. The
interaction of endogenous adenosine with the GMP-binding sites was determined by
incubating membranes in the presence or absence of adenosine deaminase (ADA).
NECA, CADO, CGS 21680 and CPA (only at the highest concentration used) increased
GMP binding in the presence of ADA. However, in the absence of ADA, the control
levels of GMP binding were as high as in the presence of added ADA plus adenosine
agonists, indicating that endogenous adenosine modulates the binding of GMP. If
this site has a neuroprotective role, adenosine may be increasing its
neuromodulator and proposed protective action.
PMID- 10786701
TI - Aggregated beta amyloid peptide 1-40 decreases Ca2+- and cholinergic receptor
mediated phosphoinositide degradation by alteration of membrane and cytosolic
phospholipase C in brain cortex.
AB - The effects of full-length amyloid beta protein, A(beta) (1-40), on
phosphoinositide-specific phospholipase C (PLC) were investigated in synaptic
plasma membranes (SPM) and cytosol prepared from the cerebral cortex of adult
rats. Moreover, the role of A(beta) (1-40) on the activation of lipid
peroxidation was evaluated. The activity of phospholipase C (PLC) acting on
phosphatidylinositol (PI) and phosphatidylinositol-4,5-bisphosphate (PIP2) was
determined using exogenous labeled substrates. The subcellular fractions were the
source of enzyme(s). The radioactivity of lipid messengers derived from
degradation of [14C- arachidonoyl] PI was also determined. The stable aggregated
form of beta-amyloid peptide (1-40) at 25 microM concentration exerted
reproducible effects. The aggregated form of A(beta) (1-40) inhibited Ca(2+)
regulated PI and PIP2 degradation by SPM and cytosolic enzymes. Aggregated
A(beta) also decreased significantly the level of diacylglycerol, the product of
PLC. This additionally supports the inhibitory effect of A(beta) on membrane
bound and cytosolic PLC. Moreover, A(beta) (1-40) significantly decreased the
basal activity of the PIP2-PLC in SPM and the enzyme activity regulated through
cholinergic receptors. However, in spite of the lower enzyme activity, the
percentage distribution of inositol (1,4,5) P3 radioactivity (IP3) in the total
pool of inositol metabolites was not significantly changed. The aggregated
neurotoxic fragment, A(beta) (25-35), mimicked the effect of full-length A(beta)
(1-40). A(beta) (1-40) enhanced the level of malondialdehyde indicating an
activation of free radical stimulated membrane lipid peroxidation that may be
involved in alteration of phospholipase(s) activity. Our results indicated that
aggregated A(beta) (1-40) alters Ca(2+)-dependent phosphoinositide degradation
affecting synaptic plasma membrane and cytosolic phospholipase(s) activity.
Moreover, this peptide significantly decreased the phosphoinositide-dependent
signal transduction mediated by cholinergic receptors. The effect of aggregated
A(beta) (1-40) is more pronounced than that of the neurotoxic fragment A(beta)
(25-35). Our study suggests that the deposition of aggregated A(beta) may alter
phosphoinositide signaling in brain.
PMID- 10786702
TI - Isolation and biochemical characterization of peroxisomes from cultured rat glial
cells.
AB - Peroxisomes are now recognized to play important cellular functions and its
dysfunction leads to a group of neurological disorders. This study reports
peroxisomal enzyme activities in cultured glial cells and peroxisomes isolated
from cultured oligodendrocytes and C6 glial cells. Peroxisomal enzyme activities
were found to be higher in oligodendroglial cells than in astrocytes or mixed
glial cells. We also developed a method for the isolation of peroxisomes from
glial cells by a combination of differential and density gradient centrifugation
techniques. Peroxisomes from oligodendrocytes in nycodenz gradient were isolated
at a density of 1.165 g/ml +/- 0.011. Activities of dihydroxyacetone phosphate
acyl transferase, beta-oxidation of lignoceric acid and alpha-oxidation of
phytanic acid were almost exclusively associated with the distribution of
catalase activity (a marker enzyme for peroxisomes) in the gradient. This
protocol should be a resource for studies designed to investigate the structure
and function of peroxisomes in brain cells.
PMID- 10786703
TI - Protective effect of oren-gedoku-to against induction of neuronal death by
transient cerebral ischemia in the C57BL/6 mouse.
AB - We examined the neuroprotective effects of oren-gedoku-to (TJ15), a herbal
medicine, after transient forebrain ischemia. Transient forebrain ischemia was
induced by occlusion of both common carotid arteries for 15 min in C57BL/6 mice
treated with TJ15. In the control ischemic group without TJ15 treatment,
histologic examination of brain tissue collected seven days after reperfusion
showed death of pyramidal cells in CA2-3 area of the hippocampus, unilaterally or
bilaterally. In mice treated with oral TJ15 (845 mg/kg/day) for five weeks, the
frequency of ischemic neuronal death was significantly lower.
Immunohistochemistry for Cu/Zn-superoxide dismutase (Cu/Zn-SOD) showed strongly
reactive astrocytes in the hippocampus of ischemic mice treated with TJ15. Damage
to nerve cells by free radicals plays an important role in the induction of
neuronal death by ischemia-reperfusion injury. Our results suggest that TJ15
protects against ischemic neuronal death by increasing the expression of Cu/Zn
SOD and suggest that oren-gedoku-to reduces the exposure of hippocampal neurons
to oxidative stress.
PMID- 10786704
TI - Compounds extracted from Phyllantus and Jatropha elliptica inhibit the binding of
[3H]glutamate and [3H]GMP-PNP in rat cerebral cortex membrane.
AB - Glutamate is to be considered a nociceptive neurotransmitter and glutamatergic
antagonists present antinoceptive activity. In this study we investigated the
effects of the naturally occurring antinociceptive compounds rutin, geraniin and
quercetine extracted from Phyllanthus, as well as the diterpene jatrophone,
extracted from Jatropha elliptica on the binding of [3H]glutamate and [3H]GMP-PNP
[a GTP analogue which binds to extracellular site(s), modulating the
glutamatergic transmission] in rat brain membrane. Jatrophone inhibited
[3H]glutamate binding and geraniin inhibited [3H]GMP-PNP binding. Quercetine
inhibited the binding of both ligands. These results may indicate a neurochemical
parameter possibly related to the antinoceptive activity of these natural
compounds.
PMID- 10786706
TI - Intrastriatal administration of methylmercury increases in vivo dopamine release.
AB - Mercury is a neurotoxin that exists in a number of physical and chemical forms,
producing different effects in the brain. In the present work, we have studied
the effects of intrastriatal administration of different doses (40 microM, 400
microM, and 4 mM) of organic mercury (methyl-mercury, MeHg) on the dopaminergic
system of rat striatum, in conscious and freely-moving animals, using
microdialysis coupled to Liquid Chromatography. In previous works, we have
discussed the effects of chronic and acute administration of MeHg on striatal
dopaminergic system assessing changes in both release and metabolism of striatal
dopamine (DA). In the present study we report that the intrastriatal
administration of different doses of MeHg (40 microM, 400 microM, and 4 mM)
produced significant increases (907 +/- 31%, 2324 +/- 156%, and 9032 +/- 70% of
basal levels, respectively for the different doses) in DA release from rat
striatal tissue associated with significant decreases in extracellular levels of
its main metabolites dihydroxyphenylacetic acid (DOPAC) and homovallinic acid
(HVA) using the dose of 4 mM MeHg (35 +/- 3% and 48 +/- 1%, respectively),
whereas non-significant changes in metabolite levels were observed with the doses
of 40 microM and 400 microM MeHg. We explain these effects as a result of
stimulated DA release and/or decreased DA intraneuronal degradation.
PMID- 10786705
TI - The role of taurine in neuronal protection following transient global forebrain
ischemia.
AB - Osmoregulation and post ischemic glutamate surge suppression (PIGSS) are
important mechanisms in the neuroprotective properties of taurine. We studied the
role of taurine in PIGSS following transient global forebrain ischemia (TGFI). A
group of gerbils received a high dose of continuous intracerebral taurine during
the peri-ischemic period. Beta-alanine was given similarly to a negative control
group. The control group consisted of animals undergoing only TGFI. On the fourth
day following commencement of drug administration, TGFI was induced.
Concurrently, half the animals from each group receiving an agent had
intracerebral microdialysis. All animals underwent histological assessment at day
7. The microdialysis and histological data was analyzed. Our results showed that
taurine treatment did not cause PIGSS. The histological difference between the
three groups was statistically insignificant. We conclude that intracerebral
taurine in the dosage administered during peri-ischemic period, does not result
in PIGSS or histologically evident neuroprotection.
PMID- 10786707
TI - A new subdivision, marginal division, in the neostriatum of the monkey brain.
AB - A new subdivision, the "marginal division" (MrD), was discovered at the caudal
border of the striatum and surrounds the rostral edge of the globus pallidus in
the rat brain in our previous studies. The neuronal somata of the MrD are mostly
fusiform in shape with their long axes lining dorsoventrally. The MrD is more
densely filled with substance P (SP)-, Leucine-enkephalin (L-Enk)-, dynorphin B-,
neurotensin-, somatostatin- and cholecystokinin (CCK)-immunoreactive fibers and
terminal-like structures than the rest of the striatum. The MrD was confirmed in
the cat neostriatum as well. The present study intended to explore whether the
MrD exists in the monkey neostriatum (putamen) with Nissl, histochemical and
immunohistochemical methods. A band of fusiform neurons were obviously identified
at the caudomedial edge of the putamen. These neurons lie outside the lateral
medullary lamina and indirectly surround the rostrolateral border of the globus
pallidus. The abundance of SP-, L-Enk-, neuropeptide Y-, CCK-, dopamine- and
serotonin-positive fibers and terminal-like structures with a few positive
fusiform neurons accumulating at the caudomedial border of the putamen obviously
distinguishes this zone from the rest of neostriatum and globus pallidus. The
acetylcholinesterase (AChE) positive and nicotinamide adenine dinucleotide
phosphate diaphorase (NADPH-d) containing fusiform neurons are distinctly
visualized in the same zone. The morphological figure and the location of these
neurons, and the histochemical and immunohistochemical characteristics of this
area coincide well with those of the MrD in the rat and cat striatum. This study
thus convincingly identifies the existence of the MrD in the monkey neostriatum.
It is fairly asserted that the MrD is a universal structure in the mammalian
brain.
PMID- 10786708
TI - Decreased phosphorylation levels of TrkB neurotrophin receptor in the spinal
cords from patients with amyotrophic lateral sclerosis.
AB - Amyotrophic lateral sclerosis (ALS) is characterized by the selective
degeneration of specific populations of cranial and spinal motor neurons. In this
study, we examined the expression of the high affinity functional receptor for
BDNF, TrkB, and assessed the functional state of TrkB by examining the level of
phosphorylation on tyrosine residues in ALS spinal cords. The data showed that
TrkB-immunoprecipitates prepared from cell-free lysates of ALS spinal cords by
use of an anti-TrkB antibody contained much more TrkB protein than from controls.
These TrkB proteins expressed in ALS spinal cords, however, are much less
phosphorylated on tyrosine residues than those of controls. Moreover, RT-PCR
analysis of TrkB mRNA in ALS spinal cords demonstrated that the expression of Trk
B mRNA is also upregulated in ALS spinal cords compared with those of controls.
These data strongly suggest that there exists an abnormality in TrkB-mediated
intracellular signaling in ALS spinal cords and shed a light on the possibility
of the therapeutic intervention by normalizing this intracellular signaling.
PMID- 10786709
TI - Degradation of soluble amyloid beta-peptides 1-40, 1-42, and the Dutch variant 1
40Q by insulin degrading enzyme from Alzheimer disease and control brains.
AB - Insulin degrading enzyme (IDE) is a metalloprotease that has been involved in
amyloid beta peptide (A(beta)) degradation in the brain. We analyzed the ability
of human brain soluble fraction to degrade A(beta) analogs 1-40, 1-42 and the
Dutch variant 1-40Q at physiological concentrations (1 nM). The rate of synthetic
125I-A(beta) degradation was similar among the A(beta) analogs, as demonstrated
by trichloroacetic acid precipitation and SDS-PAGE. A 110 kDa protein,
corresponding to the molecular mass of IDE, was affinity labeled with either 125I
insulin, 125I-Abeta 1-40 or 125I-A(beta) 1-42 and both A(beta) degradation and
cross-linking were specifically inhibited by an excess of each peptide.
Sensitivity to inhibitors was consistent with the reported inhibitor profile of
IDE. Taken together, these results suggested that the degradation of A(beta)
analogs was due to IDE or a closely related protease. The apparent Km, as
determined using partially purified IDE from rat liver, were 2.2 +/- 0.4, 2.0 +/-
0.1 and 2.3 +/- 0.3 microM for A(beta) 1-40, A(beta) 1-42 and A(beta) 1-40Q,
respectively. Comparison of IDE activity from seven AD brain cytosolic fractions
and six age-matched controls revealed a significant decrease in A(beta) degrading
activity in the first group, supporting the hypothesis that a reduced IDE
activity may contribute to A(beta) accumulation in the brain.
PMID- 10786711
TI - Effects of protonophores on membrane electrical characteristics in NG108-15
cells.
AB - Studies were conducted to determine the effects of bath application of the
protonophores carbonyl cyanide m-chlorophenylhydrazone (CCCP) and carbonyl
cyanide p-(trifluoromethoxy)-phenylhydrazone (FCCP) on membrane electrical
characteristics of differentiated NG108-15 (neuroblastoma X glioma hybrid) cells.
Membrane resting potential (Vm), input resistance (R(in)) and electrically
induced action potential generation were measured using intracellular micro
electrode techniques. Both compounds produced concentration-dependent
depolarization rather than the hyperpolarization commonly found with other
central mammalian neurons. CCCP and FCCP also reduced R(in) and disrupted the
generation of action potentials in a concentration-dependent manner. The
contribution of the observed alterations to the in vivo toxicity of these
compounds remains to be established.
PMID- 10786710
TI - Effects of chronic ethanol administration on serotonin metabolism in the various
regions of the rat brain.
AB - Changes in serotonin (5-HT) and 5-hydroxy indole acetic acid (5-HIAA), its major
metabolite, in cerebral cortex, corpus striatum and hippocampus were investigated
at 10th and 21st days of chronic ethanol ingestion in Wistar rats. Ethanol (7.2%
v/v) was given to rats in a modified liquid diet. Biochemical analysis was
performed in two groups of ethanol-treated and control rats (n = 6 for each
group). Rats in each group were decapitated at the 10th and 21st days of ethanol
consumption. Brains were removed and cerebral cortex, corpus striatum and
hippocampus were dissected. 5-HT and 5-HIAA levels were measured in respective
brain regions by using high performance liquid chromatography. In cerebral cortex
and corpus striatum, 5-HT levels were significantly lower than control at the
10th day of ethanol consumption. At the 21st day, the levels tended to remain
low, but not significantly different statistically. In hippocampus, 5-HIAA levels
were significantly higher than control at 10th day of ethanol consumption.
Increased 5-HIAA level returned to control values at the 21 st day of ethanol
consumption. Our results suggest that, 5-HT clearly seems to play a critical role
in the brain at the 10th day of chronic ethanol consumption.
PMID- 10786712
TI - Cortical impact injury in rats promotes a rapid and sustained increase in
polyunsaturated free fatty acids and diacylglycerols.
AB - Neurotrauma activates the release of membrane phospholipid-derived second
messengers, such as free arachidonic acid (20:4n-6, AA) and diacylglycerols
(DAGs). In the present study, we analyze the effect of cortical impact injury of
low-grade severity applied to the rat frontal right sensory-motor cortex (FRC) on
the accumulation of free fatty acids (FFAs) and DAGs in eight brain areas 30 min
and 24 hours after the insult. At these times, accumulation of FFAs and DAGs
occurred mainly in the damaged FRC. The cerebellum was the only other brain area
that displayed a significant accumulation of DAGs by day one post-injury. By 30
min, accumulation of free AA in the FRC displayed the greatest relative increase
(300% over sham value), followed by free docosahexaenoic acid (22:6n-3, DHA,
150%), while both 20:4-DAGs and 22:6-DAGs were increased 100% over sham values.
At day one, free 22:6 and 22:6-DAGs showed the greatest increase (590% and 230%,
respectively). These results suggest that TBI elicits the hydrolysis of
phospholipids enriched in excitable membranes, targeting early on 20:4
phospholipids (by 30 min post- trauma) and followed 24 hours later by
preferential hydrolysis of DHA-phospholipids. These lipid metabolic changes may
contribute to the initiation and maturation of neuronal and fiber track
degeneration observed following cortical impact injury.
PMID- 10786713
TI - Responses in primary astrocytes and C6-glioma cells to ammonium chloride and
dibutyryl cyclic-AMP.
AB - Elevated brain ammonia levels are a major factor in the genesis of hepatic
encephalopathy (HE). The mechanism of ammonium chloride (NH4Cl) neurotoxicity
involves interruption of oxidative metabolism. This leads to decreased levels of
ATP concentration and subsequent glial fibrillary acidic protein (GFAP)
degradation of astrocytes and fibrous C6-glioma cells. Our study investigates
NH4Cl toxicity by evaluating changes in ATP concentration and mitochondrial
function as well as by evaluating alterations in GFAP expression. NH4Cl induced
decreases in ATP were detected after 15 minutes in C6-glioma cells and 24 hours
in both cell types. Mitochondrial function, assessed by MTT (2-4,5
dimethylthiazol A-yl)-2, 5-diphenyltetrazolium bromide) assay, was impaired in
both cell types at 24 hours following NH4Cl treatment. GFAP was also
significantly decreased in both cell types. Morphologic and metabolic toxicities
were greater in C6-glioma cells. The data clearly indicate that NH4Cl interrupts
oxidative metabolism. The greater toxicity seen in C6-glioma cells may be due to
their greater dependence on oxidative metabolism. Lastly, the decrease in GFAP is
probably a consequence of diminished ATP.
PMID- 10786714
TI - Ischemia-induced inhibition of active calcium transport into gerbil brain
microsomes: effect of anesthetics and models of ischemia.
AB - The excessive increase in intracellular Ca2+ concentration is associated with
events linking cerebral blood flow reduction to neuronal cell damage. We have
investigated the possible effect of ischemia and ischemia-reperfusion injury on
endoplasmic reticulum (ER) Ca2+ transport. Two different models of ischemia as
well as two different anesthetics were used. 5 min and 15 min of global forebrain
ischemia caused significant depression of the rate of microsomal Ca2+
accumulation in pentobarbital anesthetised gerbils. The Ca2+ uptake activity
recovered partially after 1 hour of reperfusion. Unlike pentobarbital
anesthetised gerbils, no significant changes were detected in the active
microsomal Ca(2+)-transport after 10 min of global forebrain ischemia in gerbil
forebrain and hippocampus under halothane anesthesia. In addition, using the
model of decapitation ischemia, we observed significant changes of the Ca2+
uptake in both halothane and pentobarbital anesthetised gerbils. These findings
indicate that ischemic insult alters the brain microsomal Ca2+ transport which is
not due to inhibition of the Ca(2+)-ATPase activity. However, the effect of
ischemia on this transport system is dependent on the model of ischemia and on
the type of anesthetics.
PMID- 10786715
TI - Differential utilization of the ethanolamine moiety of phosphatidylethanolamine
derived from serine and ethanolamine during NGF-induced neuritogenesis of PC12
cells.
AB - Neurite elongation involves the expansion of the plasma membrane and phospholipid
synthesis. We investigated membrane phosphatidylethanolamine (PE) biosynthesis in
PC12 cells during neurite outgrowth induced by nerve growth factor (NGF). When PE
was prelabeled with [3H]ethanolamine and the radioactivity was chased by
incubation with 1 mM unlabeled ethanolamine, the radioactivity of [3H]PE steadily
declined and [3H]ethanolamine was released into the medium in NGF-treated cells
during neurite outgrowth; in the absence of unlabeled ethanolamine, the
radioactivity of [3H]PE remained relatively constant for at least 24 hr. In
undifferentiated cells but not in NGF-treated cells, [3H]phosphoethanolamine
accumulated in significant amounts during pulse labeling, and was converted
partly to PE but largely released into the medium irrespective of incubation with
unlabeled ethanolamine. The decline in the radioactivity of [3H]PE and release of
[3H]ethanolamine following incubation with unlabeled ethanolamine were also
observed in undifferentiated cells. Thus, the ethanolamine moiety of PE derived
from ethanolamine is actively recycled in both differentiated and
undifferentiated cells. When PE was derived from [3H]serine through
phosphatidylserine (PS) decarboxylation, the decrease in radioactivity of [3H]PE
and release of [3H]ethanolamine into the medium following incubation with
unlabeled ethanolamine were observed only in NGF-treated cells, but not in
undifferentiated cells, indicating that the ethanolamine moiety of PE derived
from PS is actively recycled only in the cells undergoing NGF-induced
neuritogenesis. Thus, in PC12 cells, the ethanolamine moiety of PE derived from
PS is regulated differently from that of PE derived from ethanolamine.
PMID- 10786717
TI - Chronic cerebral hypoperfusion induces transient reversible monoaminergic changes
in the rat brain.
AB - Chronic restriction of cerebral blood flow in hypoperfused Wistar rats has been
proposed as a new model of cerebrovascular-type dementia. Using this model, we
have investigated central monoaminergic neuronal systems that are closely related
to higher brain function. Monoamine and monoamine-metabolite levels were
determined, as relative monoaminergic markers, at 1 day and 1,3,6 and 12 weeks
after the bilateral occlusion of common carotid arteries. Dopaminergic changes in
the frontal cortex and striatum were observed in hypoperfused rats at 1-3 weeks
following occlusion. Serotonergic changes were recognized at four brain regions
examined (frontal cortex, hippocampus, striatum and thalamus+midbrain). In
particular, the immediate enhancement of serotonin turnover in the striatum
appeared to influence the reaction to the acute ischemic attack such as
vasoconstriction produced by hypoperfusion. Our findings suggest that chronic
cerebral hypoperfusion induces transient reversible changes in central
monoaminergic neuronal function within three weeks of ligation of carotid
arteries. This time interval seems to represent a turning point in the process of
chronic cerebral hypoperfusion-induced progressive brain injury.
PMID- 10786718
TI - Patterns of body weight in the Baltic Republics.
AB - OBJECTIVE: Previously recorded rates of obesity in the Baltic Republics have been
among the highest in the world although little is known about how they vary
within the population. This study investigates the distribution of body mass
index (BMI) and obesity in these countries. DESIGN: Three cross-sectional surveys
conducted in the summer of 1997. SETTING: Estonia, Latvia and Lithuania.
SUBJECTS: Representative national samples of adults with measured weight and
height (Estonia: n=1154; Latvia: n=2292; Lithuania: n=2096). RESULTS: Between
country differences are particularly large among women: women from Latvia and
Lithuania are approximately three times as likely to be obese as those from
Estonia (17.4%, 18.3%, 6.0% respectively); only about one-third of this
difference is explained by the sociodemographic and behavioural factors studied.
In men, the prevalence of obesity varied only slightly among countries (Estonia:
9.9%; Latvia: 9.5%; Lithuania: 11.4%). While the prevalence of obesity increases
with age within each republic, particularly in women, it is not associated with
nationality or urban/rural region, and no consistent association is observed with
income. Obesity is inversely related to education in Latvia and in Lithuanian
women. Latvian men and women and Lithuanian men who smoked had a lower prevalence
of obesity than non-smokers. Leisure time physical activity was not associated
with obesity. CONCLUSIONS: Obesity is a major health problem in the Baltic
Republics, particularly among Latvian and Lithuanian women. The lack of
association between obesity and most demographic, socioeconomic and behavioural
factors suggests that the problem is generalized. Health promotion strategies
aiming at preventing and controlling excess weight gain in the Baltic Republics
will need to target the general population.
PMID- 10786719
TI - Lifetime alcohol consumption and breast cancer: a case-control study in Finland.
AB - OBJECTIVE: To study the association between lifetime alcohol consumption and the
risk of breast cancer. DESIGN AND SETTING: A case-control study carried out in
eastern Finland. Information about alcohol consumption was obtained by two
methods: a self-administered food frequency questionnaire (FFQ) including alcohol
consumption during the previous 12 months, and a lifetime alcohol consumption
questionnaire (AQ) which was administered by the study nurse. SUBJECTS: The study
consisted of 301 breast cancer cases (25-75 years old) and 443 population
controls. RESULTS: The subjects reported higher current alcohol consumption in
the AQ compared to the FFQ. According to the AQ, premenopausal cases consumed on
average 28 g and controls 24 g alcohol week(-1); in postmenopausal women the
values were 15 and 14 g, respectively. About 30% of premenopausal and 60% of
postmenopausal women were classified as non-drinkers. The correlation for current
alcohol consumption between the FFQ and the AQ was 0.80 in premenopausal women
but only 0.40 in postmenopausal women. Current alcohol consumption seemed to
influence the reporting of total lifetime alcohol consumption. Current alcohol
consumption was not associated with the risk of breast cancer either in
premenopausal or postmenopausal women; neither were associations found between
alcohol consumption at age of first use, use before the age of 30, or total
lifetime alcohol consumption and the risk of breast cancer. CONCLUSIONS: On
average, one to three drinks per week did not increase the risk of breast cancer
in this study. Consumption levels were, however, too low to exclude increased
risk with high regular consumption. Further research is necessary on lifetime
alcohol consumption.
PMID- 10786716
TI - Amyloid beta peptide impaired carbachol but not glutamate-mediated
phosphoinositide pathways in cultured rat cortical neurons.
AB - Signal transduction systems, including cholinergic pathways, which are likely to
be of pathophysiological significance are altered in Alzheimer's disease (AD).
Muscarinic cholinergic receptors are linked to the hydrolysis of
phosphoinositide, involving the production of inositol 1,4,5-trisphosphate
[Ins(1,4,5)P3] and the mobilization of cytosolic free calcium concentrations
([Ca2+]i). Effects of amyloid peptide (A(beta)) on these signals prior to
neuronal degeneration were examined in cultured rat cortical cells. A(beta)
increased the release of lactate dehydrogenase (LDH) in a concentration-dependent
manner, however, it was blocked by B27 supplement. Prolonged exposure to a
sublethal dose of A(beta) 25-35 or 1-42 disrupted carbachol-mediated release of
Ins(1,4,5)P3 and [Ca2+]i, which was inhibited in media supplemented with B27 or
the antioxidant vitamin E. In order to determine the specificity of the effect of
A(beta), various agonists glutamate or KCl but not bradykinin which utilize the
phosphoinositide cascade were investigated. Our results indicated that A(beta)
did not affect the stimulation of glutamate or KCl-mediated production of
Ins(1,4,5)P3 or cause elevation in [Ca2+]i. Furthermore, metabotropic agonist
trans-1-amino-cyclopentane-1,3,-dicarboxylate (ACPD) elevated calcium level was
not inhibited by A(beta) pre-treatment. Taken together, the results demonstrate
that a sublethal dose of A(beta) selectively impaired cholinergic receptor
mediated signal transduction pathways, and antioxidant or B27 supplement
attenuated this effect of A(beta). Alterations of cholinergic signaling by
prolonged exposure to A(beta) could be involved in cortical neurodegeneration
that occurs in AD. Because functional loss of cholinergic pathways is an
important aspect of AD, the differences in susceptibility of these two types of
receptors prior to other signs of A(beta) action is important and requires
further investigation.
PMID- 10786720
TI - Seasonal consumption of salad vegetables and fresh fruit in relation to the
development of cardiovascular disease and cancer.
AB - OBJECTIVE: To investigate the protective association between seasonality of
consumption of fresh fruit or salad vegetables and cancer and cardiovascular
disease (CVD) development. DESIGN AND SETTING: Face-to-face interviews, including
a food frequency questionnaire, were conducted on 1489 men and 1900 women, aged
35-75 years, who were respondents in the British Health and Lifestyle Survey
1984/85 (HALS1). CVD and cancer morbidity and mortality were determined from the
1991/92 British Health and Lifestyle Survey (HALS2) and by NHS Register
'flagging'. RESULTS: Risk was assessed by odds ratio (OR) for trend per frequency
category. In men, frequent winter salad vegetable consumption was more closely
protective than that in summer for cancer (winter OR=0.79 [0.62-0.99], P=0.045,
summer OR=0.83 [0.69-1.01], NS) and CVD (winter OR=0.85 [0.72-1.00], P=0.049,
summer OR=0.95 [0.82-1.10], NS). Fresh fruit consumption showed no significant
protection. In women, frequent salad vegetable consumption at any season was
significantly protective of CVD (winter OR=0.76 [0.65-0.89], P<0.001, summer
OR=0.76 [0.65-0.89], P<0.001), although not of cancer. Frequent fresh fruit
consumption in women was significantly protective of CVD (winter OR=0.84 [0.74
0.94], P=0.004, summer OR=0.85 [0.74-0.97], P=0.014) but not quite significant,
and only in winter, for cancer (winter OR=0.87 [0.76-1.00], P=0.052, summer
OR=0.88 [0.75-1.02], P=0.097). Maintenance of salad vegetable consumption from
summer to winter, to within one frequency category, was associated with further
protection for cancer in men (P=0.050) and CVD in women (P=0.024). CONCLUSIONS:
Diets high in fresh fruit and salad vegetables appear protective against cancer
and CVD. It is important to take into account the seasonality of consumption in
estimating and establishing significance of risk.
PMID- 10786721
TI - Mapping access to food in a deprived area: the development of price and
availability indices.
AB - OBJECTIVE: To develop and map indices to illustrate variation in the cost and
availability of healthy food. DESIGN: Two contiguous wards in London were
selected by virtue of their high Carstairs deprivation scores. A 2-km area was
defined around a randomly chosen central point. All retail outlets selling food
within the area were visited and their location recorded. A list of foods,
acceptable to the local ethnically diverse population, which met current dietary
guidelines, was devised. Data on the availability and price of 71 food items were
collected. Indices were developed using SPSS and mapped using Geographic
Information System (GIS) software. RESULTS: Information on availability and
prices were collected from 199 outlets. The mean price index shows how expensive
a shop is relative to other shops in the area. The least cost index shows the
relative expense of a shop using the cheapest ways of buying their range of
foods. Shorthand indices were tested, using data on 19 of the 71 prices.
Availability indices are also discussed, including a green availability index and
a fresh green availability index. Illustrative maps of the shop locations and the
mean price index and fresh green availability index are shown. CONCLUSIONS: Data
can be collected and indices developed which indicate geographic variation in
shop 'expensiveness', and in the price and availability of healthy food. GIS
software can be used to map these indices, to identify areas with high food
prices or low availability.
PMID- 10786722
TI - Economic crisis and malnutrition: socioeconomic determinants of anthropometric
status of preschool children and their mothers in an African urban area.
AB - OBJECTIVE: To assess the relative importance of socioeconomic and
maternal/prenatal determinants of the nutritional situation of children < 6 years
old in an urban African area after several years of economic crisis. DESIGN:
Cross-sectional cluster sample survey. SETTING: Brazzaville, capital city of the
Congo. SUBJECTS: Information on socioeconomic characteristics was gathered from a
random sample of 1368 households by house visits and anthropometric measurements
were performed using standardized procedures on preschool children (n = 2373) and
their mothers (n = 1512). RESULTS: The influence of socioeconomic factors on the
nutritional status of children, taking into account adjustment variables such as
mother's age and child's age and sex was assessed. For stunting, as well as for
the mean height-for-age index among children, the main determinants were economic
level of the household (P = 0.048 and P = 0.004, respectively), schooling of the
mother (P = 0.004 and P < 10(-3)) and living in the peripheral district (P =
0.005 and P < 10(-3)). The influence of socioeconomic determinants on weight-for
age and wasting was less straightforward. When adjusting, in addition, for
maternal and prenatal factors (mother's height and body mass index (BMI) and
birth weight), most of the effects of the socioeconomic determinants on the
nutritional status of children persisted somewhat, but the effect of the economic
level on the stunting became not significant (P = 0.11). The mean BMI of mothers
appeared to be related to the economic level of the household (P < 10(-4)), to
the marital status (P = 0.01) and to the occupation of the mother (P < 10(-4)).
CONCLUSIONS: Among the socioeconomic determinants of malnutrition in children,
some, such as economic level of the household or schooling of the mother, seem to
act mainly through prenatal factors, whereas others, mainly dwelling district
characteristics, seem to influence more directly the children's nutritional
status.
PMID- 10786723
TI - Nutrition policy in the Chilean transition.
AB - OBJECTIVE: This paper examines socioeconomic, demographic, epidemiological and
nutrition changes that have occurred in Chile in the last decades using concepts
of epidemiological and nutrition transition, and discusses policies related to
nutrition. DESIGN AND SETTING: This is a descriptive, population-based study to
analyse changes in the Chilean diet and nutrition situation including some of the
main demographic, socioeconomic and epidemiological variables. Data came from the
FAO, the National Institute of Statistics, the Ministry of Health and national
surveys. RESULTS AND POLICY IMPLICATIONS: In Chile, the epidemiological and
nutrition situation shifted from a pretransition stage with high rates of
undernutrition to a post-transition stage with increasing rates of obesity in all
groups aged less than 20 years. However, changes were not accompanied by
modifications in nutrition policy, which had been successful in reducing
undernutrition. Despite changes in diet to a 'western' diet and in nutritional
status of the population from undernutrition to obesity, food and nutrition
programmes have been maintained unaltered. Governmental and university
organizations were created in 1994 and 1995 to address the current food and
nutrition problems. The accomplishments of these institutions have been the
elaboration of dietary guidelines, reformulating the food and nutrition
programmes and the promulgation of the Food Sanitary Regulations for Chile.
CONCLUSIONS: Education for the prevention of nutrition excess problems should be
a main food and nutrition policy in developing countries.
PMID- 10786724
TI - Food variety, socioeconomic status and nutritional status in urban and rural
areas in Koutiala (Mali).
AB - OBJECTIVE: The purpose of this study was to analyse the associations between the
food variety score (FVS), dietary diversity score (DDS) and nutritional status of
children, and to assess the associations between FVS, DDS and socioeconomic
status (SES) on a household level. The study also assessed urban and rural
differences in FVS and DDS. DESIGN: Cross-sectional studies in 1994/95, including
a simplified food frequency questionnaire on food items used in the household the
previous day. A socioeconomic score was generated, based on possessions in the
households. Weight and height were measured for all children aged 6-59 months in
the households, and anthropometric indices were generated. SUBJECTS AND SETTING:
Three hundred and twenty-nine urban and 488 rural households with 526 urban and
1789 rural children aged 6-59 months in Koutiala County, Sikasso Region, Mali.
RESULTS: Children from urban households with a low FVS or DDS had a doubled risk
(OR>2) for being stunted and underweight. Those relations were not found in the
rural area. There was an association between SES and both FVS and DDS on the
household level in both areas. The FVS and DDS in urban households with the
lowest SES were higher than the FVS and DDS among the rural households with the
highest SES. CONCLUSIONS: Food variety and dietary diversity seem to be
associated with nutritional status (weight/age and height/age) of children in
heterogeneous communities, as our data from urban areas showed. In rural areas,
however, this association could not be shown. Socioeconomic factors seem to be
important determinants for FVS and DDS both in urban and rural areas. FVS and DDS
are useful variables in assessing the nutritional situation of households,
particular in urban areas.
PMID- 10786725
TI - Sociodemographic determinants of energy, fat and dietary fibre intake in
Australian adults.
AB - OBJECTIVE: To examine the relationship between sociodemographic factors (sex,
age, education, occupation and region of birth) and absolute levels of energy,
fat and fibre intake in adults at the national level. DESIGN, SETTING AND
SUBJECTS: The 1983 National Dietary Survey of Adults (NDSA), covering six
Australian capital cities, collected food and nutrient intake data using the 24
hour recall method, from subjects aged 25-64 years (n=6255). RESULTS:
Interactions of variables occurred, especially for males. The greatest effect on
male intake of all three dietary components was a combination of age and
education. For females, the main explanatory variable for fat and energy intake
was age, but that for fibre was a combination of region of birth and education.
Both education (alone or in combination) and region of birth (alone or in
combination) had a greater effect than occupation (alone or in combination).
CONCLUSIONS: Energy, fat and fibre intakes vary considerably between
sociodemographic groups. Such variability must be taken into account in
formulating policy and planning decisions and in assessing temporal change.
PMID- 10786726
TI - Short stature and hypertension in the city of Rio de Janeiro, Brazil.
AB - OBJECTIVE: Stature is a powerful indicator of poor nutrition early in life in
nations where undernutrition is a public health problem. Hypertension in adults
has been associated with factors present early in life such as low birth weight.
We tested the hypothesis that short stature is associated with hypertension among
adults. DESIGN AND SETTING: A household survey of representative adults in Rio de
Janeiro city, Brazil was carried out in 1996. SUBJECTS: Blood pressure and
anthropometric measures were collected from 2802 adults in their own households.
Prevalence estimates and modelling incorporated the sample design and weights.
RESULTS: Age-adjusted prevalence of hypertension for both sexes was lower in the
third quartile of stature distribution. In women, but not in men, the odds ratio
comparing the first quartile of stature with the fourth quartile was
statistically significant with an odds ratio of 1.68 (95%CI 1.02-2.76). Adjusting
for known risk factors for hypertension such as age, income, smoking, sodium and
alcohol intake and race, the association among women, comparing the first with
the fourth quartile for stature, was 1.84 (95%CI 1.03-3.30). With further
adjustment for residual of weight on height the ratio reduced to 1.76 (95% CI
0.97-3.19, P value of trend = 0.03). Systolic blood pressure showed a U-shaped
association with quartiles of stature, mainly among women, with a beta
coefficient significantly lower at the third quartile. CONCLUSIONS: This
association of stature with hypertension supports the theory of an important
ontogenetic dependence of adult blood pressure, at least among women.
PMID- 10786727
TI - Relationships between vitamin A, iron status and helminthiasis in Bangladeshi
school children.
AB - OBJECTIVE: To explore the relationships between biochemical indicators of vitamin
A and iron status and the intestinal helminths Ascaris lumbricoides and hookworm
in primary school children. SETTING: Two rural governmental schools in
northwestern Bangladesh. DESIGN: Cross-sectional study. SUBJECTS: The sample
consisted of 164 children in grades 3-5. METHODS: Serum retinol and beta-carotene
(by high-performance liquid chromatography, HPLC), haemoglobin (HemoCue),
ferritin (enzyme-linked immunoadsorbent assay, ELIZA) and height and weight were
measured. Dietary intake of vitamin A was assessed using a food frequency
questionnaire and faecal analyses were done using Stoll's egg-count technique.
RESULTS: The mean serum retinol was 26.8 microg dl(-1) and 20% had a level of <
20 microg dl(-1), the cut-off value for low vitamin A status. There was a strong
positive association between serum beta-carotene and serum retinol (r = 0.44, P <
0.001), suggesting those with higher retinol levels had a higher carotene intake.
Thirty-one per cent were anaemic (Hb < 11.5 g dl(-1)), 30% had iron deficiency
(serum ferritin < 12.0 microg l(-1)) and 14% were suffering from iron deficiency
anaemia. Children with a serum retinol level of 20 microg dl(-1) had
significantly lower ferritin (14.0 compared to 26.0 microg l(-1), P = 0.005) and
Hb levels (11.7 compared to 12.4 g dl(-1), P = 0.005) than those with higher
levels. The proportion of iron deficiency anaemia was significantly greater among
children with hookworm. Our data suggest that hookworm exerts its impact on iron
status independently of the vitamin A status of the host. CONCLUSIONS: Programmes
to improve iron status should consider including both vitamin A prevention
programmes and deworming.
PMID- 10786728
TI - N-3 fatty acids from fish and coronary artery disease: implications for public
health.
AB - OBJECTIVE: To review and discuss the effect of n-3 polyunsaturated fatty acids
(PUFA) from fish in the prevention and, primarily, in the treatment of coronary
artery disease (CAD). DESIGN: Overview of the literature. SETTING: Denmark.
RESULTS: There is good evidence that fish consumption may reduce the risk of CAD.
CONCLUSIONS: Fish can be recommended to reduce the risk of CAD both in healthy
subjects and in patients with a high risk of CAD or with documented CAD. The use
of fish oil concentrates can not be recommended in general, but may be considered
in patients after a myocardial infarction or in patients with
hypertriglyceridaemia. An increased intake of n-3 polyunsaturated fatty acids
from fish may have substantial implications for public health and health economy
by decreasing the risk of coronary events and sudden cardiac death.
PMID- 10786729
TI - WHO tackles food inequalities: Europe's first comprehensive Food and Nutrition
Action Plan debate, 8-10 November 1999, Malta.
PMID- 10786730
TI - Fruits and vegetables in the prevention of cancer and cardiovascular disease.
AB - OBJECTIVE: We quantified the public health benefit of fruits and vegetables on
the prevention of cancer and cardiovascular disease (CVD), using currently
available human data. DESIGN: We reviewed over 250 observational studies on
cancer and CVD. Relative risks (RRs) for high versus low intake of fruits and
vegetables were obtained. The preventable proportion of chronic diseases, i.e.
the per cent of cases attributable to low consumption of fruits and vegetables,
was estimated using three scenarios: best guess, optimistic (using stronger RRs)
and conservative (using weaker RRs and eliminating the contribution of smoking
and/or drinking). The preventable proportion was calculated for increasing
average intake from the current 250 g day(-1) to the recommended 400 g day(-1)
among the general Dutch population. RESULTS: It is estimated that in the
Netherlands cancer incidence could be reduced by 19% (12,000 cases annually, best
guess), ranging from 6% (conservative) to 28% (optimistic). Cardiovascular deaths
could be reduced by 16% (8000 deaths annually, best guess), ranging from 6% to
22%. Evidence is most abundant for gastrointestinal cancers, followed by hormone
related cancers, but limited for other sites and CVD. CONCLUSIONS: Increasing
consumption of fruits and vegetables carries a large public health potential.
Population trials and biological mechanisms should eventually provide scientific
proof of their efficacy. The available evidence is sufficient to justify public
health education and promotion aimed at a substantial increase in the consumption
of fruits and vegetables.
PMID- 10786731
TI - Silently sings the larynx its secret.
PMID- 10786732
TI - Effects of vecuronium and rocuronium in antagonistic laryngeal muscles and the
anterior tibial muscle in the cat.
AB - BACKGROUND: Adequate vocal cord paralysis and full recovery of laryngeal muscle
function are important when muscle relaxants are used perioperatively. This study
was designed to compare the effects of vecuronium and rocuronium at the vocal
cord abductor and adductor muscles and the anterior tibial muscle in cats.
METHODS: Twelve adult cats were studied under pentobarbitone-N2O/O2-anesthesia.
After supramaximal electrical stimulation of the peroneal nerve and the recurrent
laryngeal nerve (0.1 Hz and intermittent train-of-four) evoked electromyographic
responses were obtained from the anterior tibial muscle, the posterior
cricoarytenoid muscle (vocal cord abductor) and two vocal cord adductor muscles,
the lateral cricoarytenoid and the vocal muscle. Six cats received bolus doses of
increasing size of vecuronium (ED90 22.5 microg x kg(-1)) and six cats rocuronium
(ED90 90 microg x kg(-1)). RESULTS: Equipotent doses of vecuronium and rocuronium
caused a similar degree of paralysis in all muscles (vecuronium ED90: 70%
blockade at the posterior cricoarytenoid, 83% at the lateral cricoarytenoid, 84%
at the vocal muscle and 90% at the anterior tibial muscle; rocuronium ED90: 71%
at the posterior cricoarytenoid, 67% at the lateral cricoarytenoid, 78% at the
vocal muscle and 90% at the anterior tibial muscle; vecuronium 2 x ED90: 93%
blockade at the posterior cricoarytenoid, 95% at the lateral cricoarytenoid, 97%
at the vocal muscle and 99% at the anterior tibial muscle; rocuronium 2 x ED90:
89% blockade at the posterior and lateral cricoarytenoid, 93% at the vocal muscle
and 100% at the anterior tibial muscle). Onset time was significantly shorter at
the posterior cricoarytenoid muscle (290 s) compared to the lateral
cricoarytenoid muscle (400 s) after vecuronium ED90 and to the vocal muscle (150
s versus 210 s) after rocuronium ED90. Compared to the anterior tibial muscle
(interval 25-75%: 6.5 min after vecuronium 2 x ED90 and 3.3 min after rocuronium
2 x ED90 and to the posterior cricoarytenoid muscle (interval 25-75%: 7 min after
vecuronium 2 x ED90 and 4.3 min after rocuronium 2 x ED90), recovery of laryngeal
adductor muscle function was markedly delayed with both neuromuscular blocking
drugs (interval 25-75% at the lateral cricoarytenoid and vocal muscle: 14 min and
15.8 min after vecuronium 2 x ED90 and 10.3 min and 11.6 min after rocuronium 2 x
ED90 respectively). CONCLUSION: In cats, the time course of neuromuscular
blockade after vecuronium and rocuronium differs in antagonistic laryngeal
muscles. The protective laryngeal function of glottis closure recovers later than
vocal cord abduction after both vecuronium and rocuronium.
PMID- 10786733
TI - Local anaesthesia for awake fibreoptic nasotracheal intubation.
AB - BACKGROUND: Awake fibreoptic nasotracheal intubation (FNI) is performed in
potentially difficult airways under local anaesthesia. This observer-blinded
study was designed to evaluate the efficacy of upper airway anaesthesia produced
by nebulized lignocaine against combined regional block (CRB) for awake FNI.
METHODS: Forty-eight ASA 1 adults were randomly allocated to receive 4 ml of 4%
nebulized lignocaine (nebulization group) or translaryngeal block, bilateral
superior laryngeal nerve block and three 4% lignocaine-soaked cotton swabs in the
nose (CRB group). Facial grimace and patient comfort were assessed by grimace and
airway reactivity scores. Patients reported their discomfort on a 4-point score.
RESULTS: All patients underwent successful FNI without significant discomfort;
79% in the nebulization group and 83% of the patients in the CRB group reported
the procedure to be comfortable. A higher grimace score was recorded on insertion
of the endotracheal tube (ETT) through the nostril in the nebulization group when
compared to the CRB group, P<0.005. Similarly, patients in the CRB group were
more comfortable during passage of the ETT into the glottis, as compared to the
nebulization group. A progressive increase in heart rate was observed in all
patients from the beginning of the procedure, but the rise in the nebulization
group was greater, (P<0.05) and also lasted longer than in the CRB group
(P<0.05). Mean arterial pressure was higher in the nebulization group when
compared to the CRB group (P<0.05), with patients belonging to the CRB group
demonstrating considerable haemodynamic stability. CONCLUSIONS: Both nebulization
and CRB produced satisfactory anaesthesia of the upper airway, but CRB provided
better patient comfort and haemodynamic stability.
PMID- 10786734
TI - Movement of the endotracheal tube during laparoscopic hernia repair.
AB - BACKGROUND: Laparoscopic surgery is not without its problems, and one of the less
known is cephalad displacement of the carina and relative movement of the
endotracheal tube in the trachea. The aetiology of this is presumably a
consequence of both pneumoperitoneum and the Trendelenburg position frequently
adopted during laparoscopic surgery. METHOD: We studied 30 patients undergoing
laparoscopic hernia repair utilising 10 degrees of Trendelenburg position and an
intra-abdominal inflation pressure of between 12 and 15 mm Hg (mean 13.6 mm Hg).
We measured the distance between the tip of the endotracheal tube and the carina
using a fibreoptic bronchoscope. RESULT: This distance decreased only slightly,
from a mean (SD) of 39.6 (13) mm after intubation, to 38.9 (12.6) mm after
adoption of Trendelenburg tilt and pneumoperitoneum. This did not represent a
statistically significant change (P=0.09). CONCLUSION: We conclude that the
endotracheal tube does not routinely migrate towards the carina when laparoscopic
hernia repair is performed under these conditions.
PMID- 10786735
TI - Injection of morphine loco dolenti recommended as early as 1876.
AB - The peripheral site of action of opioids was proved some 20 years ago. The
concept of the peripheral action of morphine, however, appears to be over 100
years older. We report on the contents of a paper, presented on 28 April 1876 at
the meeting of the Finnish Medical Association ("Finska Lakarsallskapet"), on the
use of morphine and its sites of action. The author was Professor Knut Felix von
Willebrand, whose details are included. Prof. v. Willebrand starts by focusing on
several unwanted side effects, often seen in connection with morphine
administration, and advises how they can be avoided by using the pupils of the
eye as a manometer for tolerance of morphine, as suggested by Vibert. After
having presented four case reports which illustrate the use of morphine in his
own practice, Prof. v. Willebrand explains his conception of the sites of action
of morphine. The paper gives a lively picture of the use of morphine about 125
years ago. Furthermore, it indicates that Prof. v. Willebrand believed firmly in
the peripheral site of action of morphine and recommended to inject morphine loco
dolenti whenever possible.
PMID- 10786736
TI - The place of THAM in the management of acidemia in clinical practice.
PMID- 10786737
TI - Perioperative use of dihydropyridine calcium channel blockers.
PMID- 10786738
TI - Day-case laparoscopy: a comparison of prophylactic opioid, NSAID or local
anesthesia for postoperative analgesia.
AB - BACKGROUND: The study was aimed to evaluate the analgesic efficacy, postoperative
comfort, recovery characteristics and side effects of three different analgesic
agents administered prophylactically. METHODS: Eighty patients undergoing day
case minor operative laparoscopy were randomly allocated into four groups to
receive tenoxicam 20 mg i.v. (Group T), fentanyl 100 microg i.v. (Group F), 5 ml
of bupivacaine 2.5 mg/ml for infiltration of trocar sites (Group B), 30, 10 and 5
min before incision respectively. Bupivacaine, 35 ml, 2.5 mg/ml was also
administered into the pelvic cavity in Group B. Group P received only placebo.
Postoperative pain, analgesic requirements, first response to verbal stimulus,
first analgesic requirement, ability to walk without help, to drink and to void,
blood pressures, SpO2 and respiration rates were recorded in the PACU.
Postoperative pain was evaluated by verbal rating scale. Pain scores, analgesic
requirements and side effects were evaluated by telephone calls until the 48th
postoperative hour. RESULTS: Postoperative pain scores were lower and time to
requirement of rescue analgesics was longer in groups F and B compared to Group
P. In the PACU, analgesic requirements were lower in Group B, compared to Group
P. Nausea and vomiting were increased in Group F. CONCLUSION: Tenoxicam 20 mg
i.v. was found to be ineffective whereas bupivacaine was superior to other groups
in reducing pain and analgesic requirements. Bupivacaine also increased time to
first analgesics and obtained better recovery characteristics, underlining its
value in prophylactic pain management compared to the other two agents.
PMID- 10786739
TI - Regional anaesthesia for outpatient knee arthroscopy: a randomized clinical
comparison of two different anaesthetic techniques.
AB - BACKGROUND: The purpose of this prospective, randomized study was to evaluate the
time required to perform anaesthesia, achieve surgical block and fulfil
standardized discharge criteria in outpatients receiving knee arthroscopy with
either spinal anaesthesia or combined sciatic-femoral nerve block. METHODS: After
a standard midazolam/ketoprofen premedication and baseline measurement of
cardiovascular parameters, 50 ASA I-II patients scheduled for elective outpatient
knee arthroscopy were randomized to receive spinal anaesthesia with 8 mg of 0.5%
hyperbaric bupivacaine (group Spinal, n=25), or combined sciatic-femoral nerve
block with 25 ml of mepivacaine 20 mg ml(-1) and a multiple injection technique
(15 ml for femoral nerve block and 10 ml for sciatic nerve block). Times lasting
from skin disinfection to the end of local anaesthetic injection (preparation
time) and then to achieve surgical anaesthesia (readiness for surgery), as well
as times required for block resolution, micturition, unassisted ambulation, and
home discharge were recorded by a blinded observer. Occurrence of adverse events
was also recorded. RESULTS: Preparation time (mean+/-SD) was longer with sciatic
femoral block (8+/-2.7 min) than spinal anaesthesia (5+/-2.1 min) (P=0.0002)
while no differences were observed in the time required to achieve readiness for
surgery (14+/-5 min and 15+/-6 min in the Spinal and Sciatic-femoral groups,
respectively). No differences in haemodynamic side effects and need for
intraoperative additional analgesia were observed. Patients receiving spinal
anaesthesia showed a faster resolution of nerve block and longer time to
micturition (137+/-49 min and 231+/-101 min) than patients receiving peripheral
nerve blockade (206+/-51 min and 145+/-36 min) (P<0.0005 and P=0.002,
respectively); however, no differences were observed in the time required to
fulfil standardized discharge criteria (241+/-101 min in group Spinal and 209+/
70 min in group Sciatic-femoral; P=0.86). CONCLUSION: In patients receiving
elective outpatient knee arthroscopy, using a combined sciatic-femoral nerve
block with 25 ml of mepivacaine 20 mg ml(-1) and a multiple injection technique
results in a slightly longer preoperative time but provides similarly effective
anaesthesia with no differences in home discharge times as compared to spinal
anaesthesia with 8 mg hyperbaric bupivacaine.
PMID- 10786740
TI - No difference between bupivacaine in 0.9% and 8% glucose for spinal anaesthesia
in small children.
AB - BACKGROUND: Baricity is one of the most important factors to influence the
characteristics of distribution of the local anaesthetic and hence success and
spread of the blockade. Bupivacaine is rendered hyperbaric by adding glucose. The
effect of differing degrees of hyperbaricity remains to be evaluated. METHODS:
Two hyperbaric bupivacaine solutions, in 0.9% and in 8% glucose, for spinal
anaesthesia were investigated in 60 children, aged 1-7 years, in a double-blind,
randomised, parallel group, prospective study. The children were premedicated
with diazepam orally. Bupivacaine 5 mg ml(-1) in either 0.9% or 8% glucose was
injected in a dose of 0.4 mg kg(-1). Maximum cephalad extent and regression of
sensory block were tested by transcutaneous electrical stimulation. RESULTS:
Success rate, spread and duration of sensory block were similar in both groups.
Only one child required a single dose of fentanyl during surgery. The highest
median level of sensory block was T3 (T2-T7) (median (10th/90th percentiles)) in
both groups. Time to reach T10 did not differ between the groups. The incidence
of adverse effects was similar. Atropine was administered to one child in each
group to treat bradycardia and 6 children (10%) experienced shivering. One child
in each group vomited once. CONCLUSION: These results demonstrate that
bupivacaine in 0.9% glucose and in 8% glucose solutions are equally suitable for
spinal anaesthesia in small children. Similar success rate, spread and duration
of the sensory and motor block are achieved with both baricities of bupivacaine.
PMID- 10786741
TI - Need for a reliable pain evaluation scale in the newborn in Sweden.
AB - BACKGROUND: A major problem in pain treatment in the newborn is the ability to
assess the degree of experienced pain. Several different methods for estimating
pain in the newborn have been introduced in recent years. The objectives of this
study were to see whether pain scoring was used in Swedish neonatal units, and by
which method, and furthermore to observe whether any changes had occurred between
1993 and 1998. METHOD: A questionnaire was distributed to all Swedish neonatal
units in 1993 and 1998. RESULTS: In both 1993 and 1998, 86% of all clinics
answered the questionnaire. Two-thirds of these clinics used some method for
estimating pain in the newborn at both times. Eight clinics used a structured
method in the latter period compared to one in the earlier period. A higher
proportion of units having full intensive care measured pain compared to other
units. CONCLUSION: The study shows that an unchanging low proportion of neonatal
units in Sweden attempt to assess pain. There is a minor increase in the number
of departments that use a structured method for pain scoring. Documentation of
pain intensity is still inadequate and should be improved.
PMID- 10786742
TI - Effect of i.v. tenoxicam during caesarean delivery on platelet activity.
AB - BACKGROUND: Non-steroidal anti-inflammatory drugs inhibit platelet aggregation
and prolong bleeding time in healthy subjects. We have studied the effect of i.v.
tenoxicam during caesarean delivery on skin bleeding time, operative, and
postoperative blood loss, and beta-thromboglobulin and platelet factor 4 as
specific molecular markers for platelet activity. METHODS: Fifty women were
studied. Twenty-five were given tenoxicam 20 mg i.v. 10 min before induction of
general anaesthesia, and 25 formed a control group. Skin bleeding time and
platelet markers were determined the day before and 1 h after induction of
anaesthesia. RESULTS: In the tenoxicam group, there was an slight increase in
skin bleeding time with no statistically significant changes in platelet marker
levels. In the control group, platelet markers increased 1 h after surgery. The
surgeon's assessment of uterine relaxation, using a visual analogue score,
operating theatre blood loss, and the frequency of bleeding over 24 h after
operation, showed no significant difference between the two groups. CONCLUSION:
During caesarean delivery i.v. tenoxicam causes a slight increase in bleeding
time with no significant changes in platelet marker levels.
PMID- 10786743
TI - The effect of paracetamol (acetaminophen) on fentanyl metabolism in vitro.
AB - BACKGROUND: Fentanyl is a synthetic opioid widely used in anesthesia and
analgesia. In experimental animals and in humans it has been shown that most
fentanyl biotransformation occurs in the liver, where this opioid is converted
primarily to its N-dealkylated derivative, norfentanyl. Recent studies have shown
that fentanyl is metabolized to norfentanyl via cytochrome P-450 3A4 (CYP3A4).
CYP3A4 is responsible for the metabolism of numerous other therapeutic agents,
including those administered concurrently with fentanyl (e.g., nifedipine,
lidocaine, erythromycin and cyclosporine). Paracetamol is also metabolized by the
CYP3A family, with a Km that is nearly equal to therapeutic blood concentrations.
Since paracetamol is widely used, its potential interaction with fentanyl
metabolism would be of great interest. METHODS: In the present study, rat and
human liver microsomes were used to assess the ability of paracetamol to inhibit
fentanyl metabolism. RESULTS: In both sets of microsomes, paracetamol produced a
concentration-dependent inhibition of fentanyl oxidation to norfentanyl. Kinetic
analysis of the data showed that 0.5-5 mM paracetamol inhibited fentanyl
metabolism in a noncompetitive fashion. A Dixon plot revealed that the Ki for
paracetamol inhibition of fentanyl metabolism is approximately 3.2 mM and 2.8 mM
for human and rat liver microsomes, respectively. CONCLUSIONS: Since these
concentrations of paracetamol are approximately one order of magnitude greater
than therapeutic concentrations, it would appear that potentially important and
possibly harmful fentanyl-paracetamol drug interactions do not occur with
therapeutic concentrations of paracetamol.
PMID- 10786744
TI - The effect of dopexamine on regional tissue oxygenation, systemic inflammation
and amino acid exchange in major abdominal surgery.
AB - BACKGROUND: Beta-adrenergic agents are frequently used to improve cardiac
performance in surgical and intensive care patients. Beta-adrenergic agents have
metabolic and anti-inflammatory effects in addition to their cardiovascular
effects. Splanchnic metabolic activity increases in response to surgery and
inflammation. Dopexamine is believed to favor blood flow distribution to the
splanchnic region. METHODS: We investigated the effect of dopexamine, started
before major abdominal surgery, on postoperative patterns of systemic and
regional blood flow, metabolic response, and markers of inflammation. Twenty-one
patients undergoing major abdominal surgery were studied. All patients were
stabilized preoperatively to predefined hemodynamic endpoints with fluids. After
preoperative measurement of systemic and splanchnic oxygen transport and
splanchnic lactate, glutamine and alanine exchange and blood levels of tumor
necrosis factor (TNF) and interleukin-6 (IL-6), the patients were randomized to
receive an infusion of dopexamine at 0.5 microg kg(-1) min(-1) (group 1) or 2.0
microg kg(-1) min(-1) (group 2) or placebo. Measurements were repeated at 6 h and
24 h after the end of the operation and the blood levels of cytokines also at 36
h postoperatively. RESULTS: Dopexamine evoked an increase in cardiac index
preoperatively. Postoperatively, there was no difference between the groups in
systemic and regional hemodynamics or oxygen transport: cardiac index, splanchnic
blood flow and oxygen delivery increased similarly in each group. Accordingly,
systemic oxygen extraction decreased. Glutamine, alanine and lactate exchange did
not differ between the groups. The only metabolic change was an increased
splanchnic uptake of alanine, which also was unaffected by dopexamine. There was
no difference between the groups in TNF and IL-6 levels; TNF level did not
change, while IL-6 level increased in response to surgery. CONCLUSIONS:
Dopexamine, when added to a preoperative stabilization protocol with fluids, did
not augment the postoperative hemodynamic response, and had no effect on
postoperative metabolic and inflammatory responses.
PMID- 10786745
TI - Evaluation of pressure/volume loops based on intratracheal pressure measurements
during dynamic conditions.
AB - BACKGROUND: The aim of this study was to evaluate and compare information about
lung mechanics obtained by dynamic pressure/volume loops based on Y-piece and
intratracheal airway pressure. METHODS: Airway pressure was measured
simultaneously at the Y-piece and trachea. Flow/tidal volume was measured by
sidestream spirometry at the Y-piece. The effect of an intraluminal catheter in
the tube was evaluated in a lung model. Ten adults with acute lung injury and
mechanical ventilation were studied. Measurements were performed during volume
(VC) and pressure-controlled (PC) ventilation at different ventilator settings.
RESULTS: Lung model: There was a statistically significant difference (P<0.001)
between trachea and Y-piece pressure/volume loop areas during both VC and PC
ventilation. The ratio trachea area/Y-piece area decreased with increased
endotracheal tube resistance (r=0.96). PATIENTS: The difference between trachea
and Y-piece P/V-loops was statistically significant at all 21 ventilatory
settings (P<0.05-0.001). The tracheal loop revealed clearly intrinsic PEEP and
lowered compliance during overinflation, which was difficult or impossible to see
in the Y-piece pressure/volume loop. CONCLUSION: By measuring airway pressure at
the trachea the effect of endotracheal tube resistance during inspiration is
excluded while it is included during expiration, yielding correct end-points of
inspiration and expiration. This makes it possible to calculate accurately total
compliance of the respiratory system during dynamic conditions. By monitoring of
airway pressure in the trachea, respiratory mechanics can be assessed more
accurately and ventilatory settings adjusted to attenuate ventilator induced lung
injury.
PMID- 10786746
TI - A new method for non-invasive, manoeuvre-free determination of "static" pressure
volume curves during dynamic/therapeutic mechanical ventilation.
AB - BACKGROUND: Lung mechanics are usually measured using static or quasistatic
methods, abandoning normal ventilatory treatment. We have developed a method to
calculate the alveolar pressure during dynamic/therapeutic conditions, "the
dynostatic pressure" (P(dyn)), using airway pressure (P) measured in the trachea
and volume (V) and flow (V) at the Y-piece. METHODS: P(dyn) is calculated
according to the formula P(dyn)= (P(insp) x V(exp)-P(exp) x V(insp))/(V(exp)
V(insp)), making the assumption that inspiratory and expiratory resistances are
equal at isovolume. The method was evaluated in a lung model during dynamic
conditions comparing measured alveolar pressure (P(alv)) and P(dyn) at equal and
unequal inspiratory and expiratory resistances and P/V-curves obtained during
static and dynamic conditions. The algorithm was then applied in patients with
acute lung injury (ALI). RESULTS: When inspiratory and expiratory resistances
were equal there was an excellent agreement between the P(dyn) and the P(alv),
irrespective of ventilator settings, r(2)=0.995 (range 0.981-0.999). P(dyn)
derived compliance was equal to static values. When the ratio between inspiratory
and expiratory resistance was varied between 2.3:1 and 1:2.3 the r(2) was above
0.95 (range 0.952-0.996). Development of intrinsic PEEP and overdistension was
easily revealed in patients, as shown by the dynostatic P/V-curve. CONCLUSION:
The dynostatic method gives a breath-by-breath reflection of the interaction
between ventilatory settings and lung mechanics in patients during ordinary
ventilator treatment. It is only marginally affected by the moderate differences
in inspiratory versus expiratory resistances present in patients with ALI.
PMID- 10786747
TI - Pulsatility does not change cerebral oxygenation during cardiopulmonary bypass.
AB - BACKGROUND: To determine the effect of pulsatility during cardiopulmonary bypass
(CPB) on cerebral oxygenation, we measured oxyhaemoglobin (HbO2),
deoxyhaemoglobin (Hb) and oxidised cytochrome aa3 (CtO2) with near-infrared
spectroscopy (NIRS) in 14 patients electively scheduled for cardiac surgery.
METHODS: Cerebral oxygenation was measured during steady state CPB at a core
temperature of 32 degrees C. Non-pulsatile flow and pulsatile flow were performed
for 10 min each. RESULTS: After 14 min of CPB, HbO2, Hb and CtO2 were
significantly below prebypass values. HbO2 and CtO2 did not alter with changing
flow patterns. Hb significantly increased both during the period of nonpulsatile
(median: -0.7 vs. 0.25 micromol/l; P<0.05) and pulsatile flow (median: 0.25 vs.
0.5 micromol/l; P<0.001). This increase was independent of flow pattern.
CONCLUSIONS: Neither oxygenated haemoglobin, nor intracellular oxygenation,
represented by CtO2, indicated a beneficial effect of pulsatile perfusion during
hypothermic CPB. These results, however, are only valid for short time effects
within 10 min before rewarming from CPB and patients without flow-limiting
stenoses of the carotid artery.
PMID- 10786748
TI - Cardiac troponin I is reliable with immediate but not medium-term cardiac
complications after abdominal aortic repair.
AB - BACKGROUND: The diagnosis of cardiac complications is particularly challenging in
the postoperative course of non-cardiac surgery. Follow-up of patients suggests
that silent or symptomatic postoperative myocardial infarction have similar short
term outcomes. Cardiac troponin I (cTnI) has been reported as being a sensitive
and specific marker of these complications. METHODS: We conducted a prospective
study to determine the cut-off values of cTnI which may predict cardiac
complications, i: in the postoperative period until discharge, and ii: during a 1
year period after aortic surgery. Three hundred and twenty-nine consecutive
patients undergoing infrarenal aortic surgery were included over a 2-year period
in a single center. cTnI was measured at recovery and on the 1st, 2nd and 3rd
postoperative days. The presence or absence of cardiac complications was
classified by reviewers who had no knowledge of cTnI. For evaluation of the ideal
discrimination value of cTnI between the complicated and uncomplicated patient
groups, we calculated receiver-operator characteristics for the mean values of
the peak of cTnI. RESULTS: Thirteen patients (4%) developed 19 postoperative
cardiac complications. Thirteen patients (4%) died in the postoperative period.
Nine patients (3%) developed 10 cardiac complications during the 1-year follow-up
in 316 patients. In 280 patients, cTnI was below 0.5 ng/ml, in 22 patients
between 0.5 and 1.5 ng/ml and the 27 remaining patients had a cTnI higher than
1.5 ng/ml. The area under the curve for postoperative cardiac complications was
0.84 (SD=0.21). A limit value of 0.54 ng/ml yielded a sensitivity of 75% and a
specificity of 89%. The area under the curve for late cardiac complications was
0.45 (SD= 0.13). CONCLUSION: A cTnI level greater than 0.54 ng/ml appears to be
correlated with the occurrence of cardiac complications in the period until
discharge, but no value of cTnI is predictive of late cardiac complications
occurring in the 1st year after aortic surgery.
PMID- 10786749
TI - Accurate monitoring of blood loss: thoracic electrical impedance during
hemorrhage in the pig.
AB - BACKGROUND: Cardiovascular variables are closely regulated in that they remain
relatively stable during minor hemorrhage. We considered that such stability
would make these variables less accurate for monitoring a blood loss. In
contrast, thoracic electrical impedance would be unlikely to be a regulated
variable and could serve as a non-invasive monitor of a volume deficit. METHODS:
In 10 pigs bled (0-24 ml kg(-1)) and retransfused (to 28 ml kg(-1)) during
halothane anesthesia, the magnitude of the electrical impedance, cardiovascular,
blood gas and temperature variables, atrial natriuretic peptide and near infrared
spectroscopy of the leg muscles were recorded. RESULTS: During hemorrhage and
retransfusion, the median correlations between changes in the magnitude of the
thoracic impedance and the external blood loss ranged from 0.97 to 0.98 with an
individual range from 0.80 to 1.0. These correlation coefficients were higher and
their ranges were lower than correlations established for any other measured
parameter. CONCLUSION: During hemorrhage and retransfusion in the halothane
anesthetized pig, a change in the magnitude of thoracic electrical impedance
appears to be an accurate and also non-invasive monitor of a blood volume
deficit.
PMID- 10786750
TI - Effect of intra-aortic magnesium on renal function during and after abdominal
aortic surgery: a pilot study.
AB - BACKGROUND: Infrarenal aortic cross-clamping causes renal vasoconstriction.
Magnesium may protect against renal deterioration through its vasodilatory
properties. METHODS: Thirty patients with normal preoperative renal function
undergoing infrarenal aortic cross-clamping for elective aortic surgery received
magnesium (4 mmol) or saline into the aorta immediately after aortic cross
clamping and again just before unclamping in a double-blind fashion. Pulmonary
artery occlusion pressure was maintained 215 mmHg. Five patients with magnesium
were excluded due to need for intravenous nitroglycerine because of myocardial
ischaemia during the study. RESULTS: Postoperative creatinine clearance remained
unchanged in both groups. Urinary N-acetyl-beta-D-glucosaminidase excretion
increased before and decreased after aortic cross-clamping in both groups. The
concentrations of glutathione peroxidase in serum were identical between the two
groups. CONCLUSIONS: These data indicate that intra-aortic magnesium had no
effect on renal function during or after aortic cross-clamping.
PMID- 10786751
TI - Aerosolized surfactant in lung-lavaged adult rats: factors influencing the
therapeutic response.
AB - OBJECTIVE: To evaluate the effect of aerosolized modified natural surfactant in
adult rats with respiratory failure. METHODS: Lung-lavaged adult rats were
treated with aerosolized surfactant, aerosolized saline or a bolus of surfactant.
Surfactant was labelled with dimyristoylphosphatidylcholine (DMPC) and human
serum albumin was given intravenously for evaluation of lung protein leakage.
Blood gases and dynamic compliance were measured intermittently. At the end of
ventilation, the lungs were either fixed by vascular perfusion for histological
examination or washed for determination of total phospholipids, DMPC and human
albumin in the lavage fluid. RESULTS: Treatment with bolus surfactant led to a
quick and sustained restoration of pre-lavage blood gas values in most animals.
The response to aerosolized surfactant varied considerably, with an overall
moderate improvement of gas exchange. The saline-treated group failed to show any
significant recovery of lung function. No histopathological differences were
found between any of the groups. On average 0.46% of total administered
aerosolized surfactant could be recovered. Vascular-to-alveolar leakage of human
albumin averaged 11%, with no significant differences between the groups. Final
values for PaO2 were significantly correlated with total phospholipids in the
lavage fluid, and inversely related to the vascular-to-alveolar leakage of
albumin. CONCLUSION: Neither bolus nor aerosolized surfactant influenced lung
morphology. Nebulized surfactant improved lung function but the effect was
inferior to that obtained with bolus surfactant, and the outcome depended on the
balance between the combined pool size of exogenous and endogenous surfactant and
the vascular-to-alveolar leakage of serum protein.
PMID- 10786752
TI - Two instances of central nervous system toxicity in the same patient following
repeated ropivacaine-induced brachial plexus block.
AB - We describe two instances of central nervous system (CNS) toxicity in the same
patient following repeated brachial plexus blocks induced by high doses of
ropivacaine (6 mg x kg(-1) and 4.5 mg x kg(-1), respectively). Although very high
total and free plasma concentrations of ropivacaine were found up to 98 min after
induction of the blocks, no signs of cardiovascular toxicity apart from
hypertension and sinus tachycardia were observed. The measured plasma
concentrations are the highest so far reported in the literature. We conclude
that this case demonstrates the high cardiovascular safety level of ropivacaine.
These high doses, however, resulted in severe toxic CNS symptoms. Therefore, it
is stressed that the dose in relation to the weight of the patient must be
calculated when administering a large volume of local anesthetic.
PMID- 10786753
TI - Use of sevoflurane in difficult airways.
AB - Inhalational induction is one of the recognized methods for the management of
difficult airway. Halothane is the usual choice of agent for this purpose. The
relatively new agent sevoflurane, which is the least irritant of all the
available agents, is emerging as a choice of inhalational agent for both adult
and pediatric populations. There are various reports for and against the use of
sevoflurane for the management of difficult airway. We describe the use of
sevoflurane for the management of difficult airway in four patients presenting
with airway problems.
PMID- 10786754
TI - Reciprocating tachycardia during central venous cannulation in a patient with
Wolff-Parkinson-White syndrome.
AB - Wolff-Parkinson-White syndrome is important for the anesthesiologist because the
sudden development of tachyarrhythmias may result in deleterious hemodynamic
changes. We describe an episode of reciprocating tachycardia triggered by the
insertion of the guide wire during central venous cannulation in a patient with
this syndrome.
PMID- 10786755
TI - Infraclavicular approach to the brachial plexus.
PMID- 10786756
TI - Postoperative analgesia and rectal drug administration.
PMID- 10786758
TI - Affirmative action ignored
PMID- 10786757
TI - The effect of halothane on calcium release from human skinned masseter fiber is
not an artifact.
PMID- 10786759
TI - Wellcome in the dock.
PMID- 10786760
TI - Clean-up strategy at Australian nuclear site called into question
PMID- 10786761
TI - Middle East's synchrotron heads for Jordan.
PMID- 10786762
TI - Top physicist crosses to Boston in search of like minds
PMID- 10786763
TI - Critics blast US missile defence system as flawed
PMID- 10786764
TI - Women and ethnic minorities needed for US skills gap...
PMID- 10786765
TI - US energy agency sequences human chromosome trio.
PMID- 10786766
TI - Wellcome shoulders its share of blame for Oxford debacle.
PMID- 10786767
TI - A silence that speaks volumes.
PMID- 10786768
TI - Open-source work even more vital to genome project than to software.
PMID- 10786769
TI - Mayo and the mouse.
PMID- 10786771
TI - The paradigm and the pendulum
PMID- 10786770
TI - Mighty mice.
PMID- 10786772
TI - Respiration in the balance.
PMID- 10786773
TI - Cognitive neuroscience. Seeing in the sound zone.
PMID- 10786774
TI - Oxide-ion conductors by design
PMID- 10786775
TI - New guardians of the genome.
PMID- 10786776
TI - Neurobiology. A moving experience.
PMID- 10786777
TI - William Donald Hamilton (1936-2000)
PMID- 10786778
TI - Small bodies of the Solar System
PMID- 10786779
TI - Euler's disk and its finite-time singularity
PMID- 10786780
TI - Potential modulations along carbon nanotubes
PMID- 10786783
TI - Turbulent convection at very high Rayleigh numbers
AB - Turbulent convection occurs when the Rayleigh number (Ra)--which quantifies the
relative magnitude of thermal driving to dissipative forces in the fluid motion-
becomes sufficiently high. Although many theoretical and experimental studies of
turbulent convection exist, the basic properties of heat transport remain
unclear. One important question concerns the existence of an asymptotic regime
that is supposed to occur at very high Ra. Theory predicts that in such a state
the Nusselt number (Nu), representing the global heat transport, should scale as
Nu proportional to Ra(beta) with beta = 1/2. Here we investigate thermal
transport over eleven orders of magnitude of the Rayleigh number (10(6) < or = Ra
< or = 10(7)), using cryogenic helium gas as the working fluid. Our data, over
the entire range of Ra, can be described to the lowest order by a single power
law with scaling exponent beta close to 0.31. In particular, we find no evidence
for a transition to the Ra(1/2) regime. We also study the variation of internal
temperature fluctuations with Ra, and probe velocity statistics indirectly.
PMID- 10786782
TI - Rainforest fragmentation kills big trees.
PMID- 10786781
TI - Microbial essentials at hydrothermal vents.
PMID- 10786784
TI - Induction of visual orientation modules in auditory cortex.
AB - Modules of neurons sharing a common property are a basic organizational feature
of mammalian sensory cortex. Primary visual cortex (V1) is characterized by
orientation modules--groups of cells that share a preferred stimulus orientation-
which are organized into a highly ordered orientation map. Here we show that in
ferrets in which retinal projections are routed into the auditory pathway,
visually responsive neurons in 'rewired' primary auditory cortex are also
organized into orientation modules. The orientation tuning of neurons within
these modules is comparable to the tuning of cells in V1 but the orientation map
is less orderly. Horizontal connections in rewired cortex are more patchy and
periodic than connections in normal auditory cortex, but less so than connections
in V1. These data show that afferent activity has a profound influence on diverse
components of cortical circuitry, including thalamocortical and local
intracortical connections, which are involved in the generation of orientation
tuning, and long-range horizontal connections, which are important in creating an
orientation map.
PMID- 10786785
TI - Extended magnetic reconnection at the Earth's magnetopause from detection of bi
directional jets
AB - Magnetic reconnection is a process that converts magnetic energy into bi
directional plasma jets; it is believed to be the dominant process by which solar
wind energy enters the Earth's magnetosphere. This energy is subsequently
dissipated by magnetic storms and aurorae. Previous single-spacecraft
observations revealed only single jets at the magnetopause--while the existence
of a counter-streaming jet was implicitly assumed, no experimental confirmation
was available. Here we report in situ two-spacecraft observations of bi
directional jets at the magnetopause, finding evidence for a stable and extended
reconnection line; the latter implies substantial entry of the solar wind into
the magnetosphere. We conclude that reconnection is determined by large-scale
interactions between the solar wind and the magnetosphere, rather than by local
conditions at the magnetopause.
PMID- 10786786
TI - Statistical signatures of photon localization
AB - The realization that electron localization in disordered systems (Anderson
localization) is ultimately a wave phenomenon has led to the suggestion that
photons could be similarly localized by disorder. This conjecture attracted wide
interest because the differences between photons and electrons--in their
interactions, spin statistics, and methods of injection and detection--may open a
new realm of optical and microwave phenomena, and allow a detailed study of the
Anderson localization transition undisturbed by the Coulomb interaction. To date,
claims of three-dimensional photon localization have been based on observations
of the exponential decay of the electromagnetic wave as it propagates through the
disordered medium. But these reports have come under close scrutiny because of
the possibility that the decay observed may be due to residual absorption, and
because absorption itself may suppress localization. Here we show that the extent
of photon localization can be determined by a different approach--measurement of
the relative size of fluctuations of certain transmission quantities. The
variance of relative fluctuations accurately reflects the extent of localization,
even in the presence of absorption. Using this approach, we demonstrate photon
localization in both weakly and strongly scattering quasi-one-dimensional
dielectric samples and in periodic metallic wire meshes containing metallic
scatterers, while ruling it out in three-dimensional mixtures of aluminium
spheres.
PMID- 10786787
TI - Spontaneous macroscopic magnetization at the superconducting transition
temperature of YBa2Cu3O(7-delta)
AB - A noteworthy feature of the high-temperature superconductors is the
unconventional symmetry of the superconducting order parameter. Several
experiments have established that the order parameter has a four-fold d(x2 - y2)
symmetry under rotation of the lattice (the order parameter of conventional
superconductors is, in contrast, isotropic). An intriguing and much debated
possibility is that, in certain cases, an additional imaginary component might be
present, having an isotropic s-wave or d(xy) symmetry. A consequence of a complex
order parameter of the form d(x2 - y2) + id(xy) is that it would break both
reflection (parity, P) symmetry and time-reversal (T) symmetry, a clear signature
of which would be the spontaneous appearance of a macroscopic magnetization at
the superconducting transition temperature. Broken T symmetry has been reported,
but searches for the effects of combined P and T symmetry breaking have so far
yielded null results. Here we report the observation of a weak (approximately 10(
5) gauss) magnetic field that appears spontaneously at the superconducting
transition temperature of epitaxial thin films of YBa2Cu3O(7-delta). The magnetic
signal originates near the edges of the samples. One interpretation for this
observation is that the order parameter carries an intrinsic angular momentum,
related to the breaking of P and T symmetries, but other possibilities cannot yet
be excluded.
PMID- 10786788
TI - Designing fast oxide-ion conductors based on La2Mo2O9
AB - The ability of solid oxides to conduct oxide ions has been known for more than a
century, and fast oxide-ion conductors (or oxide electrolytes) are now being used
for applications ranging from oxide fuel cells to oxygen pumping devices. To be
technologically viable, these oxide electrolytes must exhibit high oxide-ion
mobility at low operating temperatures. Because of the size and interaction of
oxygen ions with the cationic network, high mobility can only be achieved with
classes of materials with suitable structural features. So far, high mobility has
been observed in only a small number of structural families, such as fluorite,
perovskites, intergrowth perovskite/Bi2O2 layers and pyrochlores. Here we report
a family of solid oxides based on the parent compound La2Mo2O9 (with a different
crystal structure from all known oxide electrolytes) which exhibits fast oxide
ion conducting properties. Like other ionic conductors, this material undergoes a
structural transition around 580 degrees C resulting in an increase of conduction
by almost two orders of magnitude. Its conductivity is about 6 x 10(-2) S cm(-1)
at 800 degrees C, which is comparable to that of stabilized zirconia, the most
widely used oxide electrolyte. The structural similarity of La2Mo2O9 with beta
SnWO4 (ref. 14) suggests a structural model for the origin of the oxide-ion
conduction. More generally, substitution of a cation that has a lone pair of
electrons by a different cation that does not have a lone pair--and which has a
higher oxidation state--could be used as an original way to design other oxide
ion conductors.
PMID- 10786789
TI - Evidence that decomposition rates of organic carbon in mineral soil do not vary
with temperature.
AB - It has been suggested that increases in temperature can accelerate the
decomposition of organic carbon contained in forest mineral soil (Cs), and,
therefore, that global warming should increase the release of soil organic carbon
to the atmosphere. These predictions assume, however, that decay constants can be
accurately derived from short-term laboratory incubations of soil or that in situ
incubations of fresh litter accurately represent the temperature sensitivity of
Cs decomposition. But our limited understanding of the biophysical factors that
control Cs decomposition rates, and observations of only minor increases in Cs
decomposition rate with temperature in longer-term forest soil heating
experiments and in latitudinal comparisons of Cs decomposition rates bring these
predictions into question. Here we have compiled Cs decomposition data from 82
sites on five continents. We found that Cs decomposition rates were remarkably
constant across a global-scale gradient in mean annual temperature. These data
suggest that Cs decomposition rates for forest soils are not controlled by
temperature limitations to microbial activity, and that increased temperature
alone will not stimulate the decomposition of forest-derived carbon in mineral
soil.
PMID- 10786790
TI - Respiration as the main determinant of carbon balance in European forests.
AB - Carbon exchange between the terrestrial biosphere and the atmosphere is one of
the key processes that need to be assessed in the context of the Kyoto Protocol.
Several studies suggest that the terrestrial biosphere is gaining carbon, but
these estimates are obtained primarily by indirect methods, and the factors that
control terrestrial carbon exchange, its magnitude and primary locations, are
under debate. Here we present data of net ecosystem carbon exchange, collected
between 1996 and 1998 from 15 European forests, which confirm that many European
forest ecosystems act as carbon sinks. The annual carbon balances range from an
uptake of 6.6 tonnes of carbon per hectare per year to a release of nearly 1 t C
ha(-1) yr(-1), with a large variability between forests. The data show a
significant increase of carbon uptake with decreasing latitude, whereas the gross
primary production seems to be largely independent of latitude. Our observations
indicate that, in general, ecosystem respiration determines net ecosystem carbon
exchange. Also, for an accurate assessment of the carbon balance in a particular
forest ecosystem, remote sensing of the normalized difference vegetation index or
estimates based on forest inventories may not be sufficient.
PMID- 10786791
TI - Determination of relative growth rates of natural quartz crystals
AB - Although the theory describing crystal growth in the geological environment is
well established, there are few quantitative studies that delimit the absolute
time involved in the growth of natural crystals. The actual mechanisms
responsible for the variation in size and shape of individual crystal faces are,
in fact, not well understood. Here we describe a micro-infrared spectroscopic
study of a single, gem-quality quartz crystal that allows us to measure the size,
shape and relative growth rate of each of the crystal faces that are active
throughout its growth history. We demonstrate that the abundances of hydrogen
bearing impurities can serve as 'speedometers' to monitor the growth rate of
advancing crystal faces. Our technique can be applied to crystals from a variety
of geological environments to determine their growth histories. Within the
electronics industry, the technique might facilitate the production of defect
free synthetic crystals required for high-quality resonators and, ultimately,
might allow determination of the absolute time involved in geological processes
such as the crystallization of magmas, fluid flow in metamorphism and the sealing
of open cracks in earthquake rupture zones.
PMID- 10786792
TI - Insurance-based advantage to helpers in a tropical hover wasp.
AB - The origin and maintenance of eusociality is a central problem in evolutionary
biology. Eusocial groups contain individuals that forfeit their own reproduction
in order to help others reproduce. In facultatively eusocial taxa, offspring can
choose whether to found new nests or become helpers in their natal groups. In
many facultatively eusocial insects, offspring need continuous care during
development, but adult carers have life expectancies shorter than the
developmental period. When a lone foundress dies, her partly reared brood are
usually doomed. Here, we show that helpers in a tropical hover wasp
(Liostenogaster flavolineata) have an insurance-based advantage over lone
foundresses because after a helper dies, most of the brood that she has partly
reared will be brought to maturity by surviving nest-mates. After some of the
helpers are experimentally removed from a multi-female nest, the reduced group is
left with more brood than it would normally rear. We found that larger, more
valuable extra brood were reared through to maturity, but not smaller, less
valuable brood. Smaller brood may be sacrificed to feed larger brood, and reduced
groups probably benefited from increased short-term helper recruitment. Rearing
extra brood did not increase adult mortality or brood development time.
PMID- 10786793
TI - Visual behaviour mediated by retinal projections directed to the auditory
pathway.
AB - An unresolved issue in cortical development concerns the relative contributions
of intrinsic and extrinsic factors to the functional specification of different
cortical areas. Ferrets in which retinal projections are redirected neonatally to
the auditory thalamus have visually responsive cells in auditory thalamus and
cortex, form a retinotopic map in auditory cortex and have visual receptive field
properties in auditory cortex that are typical of cells in visual cortex. Here we
report that this cross-modal projection and its representation in auditory cortex
can mediate visual behaviour. When light stimuli are presented in the portion of
the visual field that is 'seen' only by this projection, 'rewired' ferrets
respond as though they perceive the stimuli to be visual rather than auditory.
Thus the perceptual modality of a neocortical region is instructed to a
significant extent by its extrinsic inputs. In addition, gratings of different
spatial frequencies can be discriminated by the rewired pathway, although the
grating acuity is lower than that of the normal visual pathway.
PMID- 10786795
TI - Ion permeation mechanism of the potassium channel.
AB - Ion-selective channels enable the specific permeation of ions through cell
membranes and provide the basis of several important biological functions; for
example, electric signalling in the nervous system. Although a large amount of
electrophysiological data is available, the molecular mechanisms by which these
channels can mediate ion transport remain a significant unsolved problem. With
the recently determined crystal structure of the representative K+ channel (KcsA)
from Streptomyces lividans, it becomes possible to examine ion conduction
pathways on a microscopic level. K+ channels utilize multi-ion conduction
mechanisms, and the three-dimensional structure also shows several ions present
in the channel. Here we report results from molecular dynamics free energy
perturbation calculations that both establish the nature of the multiple ion
conduction mechanism and yield the correct ion selectivity of the channel. By
evaluating the energetics of all relevant occupancy states of the selectivity
filter, we find that the favoured conduction pathway involves transitions only
between two main states with a free difference of about 5 kcal mol(-1). Other
putative permeation pathways can be excluded because they would involve states
that are too high in energy.
PMID- 10786794
TI - Experience-dependent plasticity of dendritic spines in the developing rat barrel
cortex in vivo.
AB - Do changes in neuronal structure underlie cortical plasticity? Here we used time
lapse two-photon microscopy of pyramidal neurons in layer 2/3 of developing rat
barrel cortex to image the structural dynamics of dendritic spines and filopodia.
We found that these protrusions were highly motile: spines and filopodia
appeared, disappeared or changed shape over tens of minutes. To test whether
sensory experience drives this motility we trimmed whiskers one to three days
before imaging. Sensory deprivation markedly (approximately 40%) reduced
protrusive motility in deprived regions of the barrel cortex during a critical
period around postnatal days (P)11-13, but had no effect in younger (P8-10) or
older (P14-16) animals. Unexpectedly, whisker trimming did not change the
density, length or shape of spines and filopodia. However, sensory deprivation
during the critical period degraded the tuning of layer 2/3 receptive fields.
Thus sensory experience drives structural plasticity in dendrites, which may
underlie the reorganization of neural circuits.
PMID- 10786796
TI - CD1c-mediated T-cell recognition of isoprenoid glycolipids in Mycobacterium
tuberculosis infection.
AB - The discovery of the CD1 antigen presentation pathway has expanded the spectrum
of T-cell antigens to include lipids, but the range of natural lipid antigens and
functions of CD1-restricted T cells in vivo remain poorly understood. Here we
show that the T-cell antigen receptor and the CD1c protein mediate recognition of
an evolutionarily conserved family of isoprenoid glycolipids whose members
include essential components of protein glycosylation and cell-wall synthesis
pathways. A CD1c-restricted, mycobacteria-specific T-cell line recognized two
previously unknown mycobacterial hexosyl-1-phosphoisoprenoids and structurally
related mannosyl-beta1-phosphodolichols. Responses to mannosyl-beta1
phosphodolichols were common among CD1c-restricted T-cell lines and peripheral
blood T lymphocytes of human subjects recently infected with M. tuberculosis, but
were not seen in naive control subjects. These results define a new class of
broadly distributed lipid antigens presented by the CD1 system during infection
in vivo and suggest an immune mechanism for recognition of senescent or
transformed cells that are known to have altered dolichol lipids.
PMID- 10786797
TI - Integration of floral inductive signals in Arabidopsis.
AB - Flowering of Arabidopsis is regulated by a daylength-dependent pathway that
accelerates flowering in long days and a daylength-independent pathway that
ensures flowering in the absence of inductive conditions. These pathways are
genetically separable, as there are mutations that delay flowering in long but
not short days. Conversely, mutations that block synthesis of the hormone
gibberellin abolish flowering in short days, but have on their own only a minor
effect in long days. A third pathway, the autonomous pathway, probably acts by
modulating the other two pathways. Understanding where and how these pathways are
integrated is a prerequisite for understanding why similar environmental or
endogenous cues can elicit opposite flowering responses in different plants. In
Arabidopsis, floral induction leads ultimately to the upregulation of floral
meristem-identity genes such as LEAFY, indicating that floral inductive signals
are integrated upstream of LEAFY Here we show that gibberellins activate the
LEAFY promoter through cis elements that are different from those that are
sufficient for the daylength response, demonstrating that the LEAFY promoter
integrates environmental and endogenous signals controlling flowering time.
PMID- 10786800
TI - Single-molecule analysis of DNA uncoiling by a type II topoisomerase.
AB - Type II DNA topoisomerases are ubiquitous ATP-dependent enzymes capable of
transporting a DNA through a transient double-strand break in a second DNA
segment. This enables them to untangle DNA and relax the interwound supercoils
(plectonemes) that arise in twisted DNA. In vivo, they are responsible for
untangling replicated chromosomes and their absence at mitosis or meiosis
ultimately causes cell death. Here we describe a micromanipulation experiment in
which we follow in real time a single Drosophila melanogaster topoisomerase II
acting on a linear DNA molecule which is mechanically stretched and supercoiled.
By monitoring the DNA's extension in the presence of ATP, we directly observe the
relaxation of two supercoils during a single catalytic turnover. By controlling
the force pulling on the molecule, we determine the variation of the reaction
rate with the applied stress. Finally, in the absence of ATP, we observe the
damping of a DNA crossover by a single topoisomerase on at least two different
timescales (configurations). These results show that single molecule experiments
are a powerful new tool for the study of topoisomerases.
PMID- 10786798
TI - Role of NF-kappaB in p53-mediated programmed cell death.
AB - The tumour suppressor p53 inhibits cell growth through activation of cell-cycle
arrest and apoptosis, and most cancers have either mutation within the p53 gene
or defects in the ability to induce p53. Activation or re-introduction of p53
induces apoptosis in many tumour cells and may provide effective cancer therapy.
One of the key proteins that modulates the apoptotic response is NF-kappaB, a
transcription factor that can protect or contribute to apoptosis. Here we show
that induction of p53 causes an activation of NF-kappaB that correlates with the
ability of p53 to induce apoptosis. Inhibition or loss of NF-kappaB activity
abrogated p53-induced apoptosis, indicating that NF-kappaB is essential in p53
mediated cell death. Activation of NF-kappaB by p53 was distinct from that
mediated by tumour-necrosis factor-alpha and involved MEK1 and the activation of
pp90rsk. Inhibition of MEK1 blocked activation of NF-kappaB by p53 and completely
abrogated p53-induced cell death. We conclude that inhibition of NF-kappaB in
tumours that retain wild-type p53 may diminish, rather than augment, a
therapeutic response.
PMID- 10786801
TI - Histopathologic features of Burkholderia cepacia pneumonia in patients without
cystic fibrosis.
AB - We present the histopathologic features of fatal Burkholderia cepacia pneumonia
in three adults (one man [age 44 years] and two women [aged 40 and 43 years]). In
all patients, the pulmonary infiltrates initially were localized (right middle
lobe, left upper lobe, and right middle lobe) but rapidly progressed. Two open
lung biopsies and one pneumonectomy specimen showed necrotizing granulomatous
inflammation merging with areas of more conventional necrotizing bronchopneumonia
In one patient, a mediastinal lymph node also showed stellate necrotizing
granulomas. Vasculitis was absent. B. cepacia was cultured from the open-lung
biopsies and bronchial wash specimens in two patients and from postmortem
cultures of lung, subcarinal lymph nodes, and blood in the third. The
histopathology in these patients resembles that of melioidosis, which is caused
by a related organism, Burkholderia pseudomallei. B. cepacia needs to be
considered in the differential diagnosis of necrotizing granulomatous
inflammation. In addition, given the rarity with which B. cepacia is identified
as a cause of pneumonia in the immunocompetent host, isolation of B. cepacia
should trigger a workup for underlying immunodeficiency or lead to an
investigation to exclude the possibility of a nosocomial infection.
PMID- 10786799
TI - Interplay of p53 and DNA-repair protein XRCC4 in tumorigenesis, genomic stability
and development.
AB - XRCC4 is a non-homologous end-joining protein employed in DNA double strand break
repair and in V(D)J recombination. In mice, XRCC4-deficiency causes a pleiotropic
phenotype, which includes embryonic lethality and massive neuronal apoptosis.
When DNA damage is not repaired, activation of the cell cycle checkpoint protein
p53 can lead to apoptosis. Here we show that p53-deficiency rescues several
aspects of the XRCC4-deficient phenotype, including embryonic lethality, neuronal
apoptosis, and impaired cellular proliferation. However, there was no significant
rescue of impaired V(D)J recombination or lymphocyte development. Although p53
deficiency allowed postnatal survival of XRCC4-deficient mice, they routinely
succumbed to pro-B-cell lymphomas which had chromosomal translocations linking
amplified c-myc oncogene and IgH locus sequences. Moreover, even XRCC4-deficient
embryonic fibroblasts exhibited marked genomic instability including chromosomal
translocations. Our findings support a crucial role for the non-homologous end
joining pathway as a caretaker of the mammalian genome, a role required both for
normal development and for suppression of tumours.
PMID- 10786802
TI - Polymorphism at codon 72 of p53 is not associated with cervical cancer risk.
AB - P53 allelic polymorphism at codon 72 has been studied as a possible predisposing
factor for cervical carcinogenesis with inconsistent results. Storey and
colleagues recently published the interesting finding of a 7-fold increased risk
for cervical cancer in women homozygous for the arginine allele at codon 72. This
stimulated a number of independent investigations, the majority of which found no
association of cervical cancer and arginine homozygosity. With the use of a
modified Storey method for determining codon 72 allelotypes, DNA was examined
from 431 microdissected, formalin-fixed, archival cervical conization specimens
ranging from low-grade squamous lesions to invasive cancer. An alternative
independent method using restriction fragment length polymorphism analysis was
performed on all arginine homozygotes and all indeterminate cases for
confirmation and final allelotype assignment. With the use of Storey's method
alone, logistic regression suggested an association (odds ratio, 1.42) between
arginine homozygosity and invasive disease. However, with the use of the combined
method for accurate allelotyping, this trend disappeared (odds ratio, 1.00), the
discordance was clearly resolvable as being due to methodologic variables. With
the use of two separate methods for codon 72 allelotyping and accounting for a
number of the issues raised in previously published reports, there is no
increased risk for invasive cervical cancer associated with arginine homozygosity
at codon 72 of p53.
PMID- 10786804
TI - Metallothionein in pancreatic endocrine neoplasms.
AB - Metallothioneins (MTs) are intracellular proteins that bind to metal ions and are
involved in heavy metal homeostasis and detoxification. Pancreatic islets were
shown to be positive for zinc-containing matrix metalloproteinase-2 and -9 by
immunocytochemical staining. The immunolocalization of matrix metalloproteinases
in pancreatic islets prompted us to study further the link between zinc and MT in
34 cases of pancreatic endocrine neoplasms, including insulinomas, glucagonomas,
gastrinomas, pancreatic polypeptide-omas, and non-functioning endocrine
neoplasms. Four types of islet cells were found to be positive for MT, whereas
pancreatic endocrine neoplasms mostly were either weakly positive or negative for
MT. The presence of MT in normal islet cells and pancreatic endocrine neoplasms
is consistent with the notion that MTs modulate zinc homeostasis and metabolism
in pancreatic islet cells and pancreatic endocrine neoplasms as those tissues
contain zinc-containing matrix metalloproteinases.
PMID- 10786803
TI - Immunohistochemical profile of endometrial adenocarcinoma: a study of 61 cases
and review of the literature.
AB - The differences in immunohistochemical expression of p53, bcl-2, bax, estrogen
receptor (ER), and progesterone receptor (PR) were evaluated in 40 endometrioid
and 21 papillary serous carcinomas of endometrium and correlated with known
predictors of survival, such as grade and stage. Uterine papillary serous
adenocarcinomas (UPSA) showed significantly higher p53 expression than did
uterine endometrioid adenocarcinomas (UEA) (76.2% versus 35%), whereas both ER
and PR were more often positive in endometrioid than in serous tumors (p = .005
and .0005). No significant difference was found in bcl-2 and bax expression
between both histologic types. However, there was definite decrease in intensity
of bcl-2 in UPSA compared with UEA. In endometrioid carcinoma, p53 overexpression
was associated with high-grade and advanced-stage tumors (p = .0006 and .006),
whereas ER and PR expression was associated with low-grade and early-stage tumors
(p = .0006 and .0001; p = .003 and .0006). Bcl-2 immunopositivity was more common
in low-grade, early-stage rather than in high-grade, advanced-stage
adenocarcinomas, but the difference was not statistically significant (p = .24
and .07). Bax immunopositivity was associated with well-differentiated (p = .04)
and early-stage tumors. Furthermore, a significant inverse relationship between
bax and p53 reactivity was defined (p = .05), especially in tumors of
endometrioid type. Bax and PR immunoexpression correlated near the limit of
statistical significance (p = .08), whereas no relationship was found among bax,
bcl-2, and ER immunopositivity. Our results indicate that the differences in
immunohistochemical profiles of endometrioid and serous carcinomas support the
existence of different molecular pathways of their development. The correlation
of immunohistochemical findings with histologic grade and clinical stage could
help in predicting biologic behavior and planning treatment in patients who are
diagnosed as having these tumors.
PMID- 10786806
TI - Assessing the expression of two genes simultaneously in surgical specimens using
polymerase chain reaction.
AB - We developed a novel polymerase chain reaction (PCR)-based method to analyze
simultaneously the relative expression of two genes in a single PCR reaction. The
method, relational PCR (R-PCR), utilizes special PCR primers that enable a PCR
reaction to be converted from a standard uniplex reaction to a multiplex reaction
in which all products are dependent on the same reaction components for
amplification. We show that the quantitative ability of R-PCR is unaffected by
sample nucleic acid input concentration over a range of 25-fold (30 to 750 ng of
total RNA) and demonstrate excellent interexperimental reproducibility. We used R
PCR to analyze estrogen receptor gene expression in a series of invasive breast
carcinomas, and our results show an excellent correlation between estrogen
receptor mRNA expression and protein product accumulation determined by standard
immunocytochemistry on paraffin sections.
PMID- 10786805
TI - Expression of DNA topoisomerase IIalpha in thyroid neoplasia.
AB - Topoisomerase II (topo II) is an enzyme that affects replication, transcription,
and chromosome segregation. It serves as a target for several useful
antichemotherapeutic agents, such as etoposide (VP-16) and teniposide (VM26).
Monoclonal antibody topo IIalpha (Clone JH2.7; Neomarkers, Union City, CA)
specifically identifies the alpha isoform of topo II. Using this antibody in an
immunohistochemical analysis, we studied differential expression of topo II in a
variety of thyroid lesions. The topo II labeling index is defined as the number
of topo II staining positive nuclei divided by the total number of tumor cells
counted multiplied by 100. An average of 1,000 cells were counted in each case.
The average labeling indexes for anaplastic carcinoma (7.8), tall cell variant of
papillary carcinoma (4.8), follicular carcinoma (2.6), Hurthle cell carcinoma
(3.4), and medullary carcinoma (2.4) were much higher than for papillary
carcinoma (0.76), follicular adenoma (0.65), Hurthle cell adenoma (0.32), and
normal thyroid (0.1). This study suggests that immunohistochemical analysis of
topo II correlates with thyroid tumor histology; it is more frequently expressed
in tumors that are associated with aggressive clinical behavior. It may help to
define a role for anti-topoisomerase drugs in treatment of aggressive thyroid
neoplasms.
PMID- 10786807
TI - Effects of multidrug resistance gene expression in acute erythroleukemia.
AB - Acute erythroleukemia is a relatively rare disorder of a multilineal nature.
Patients with this type of leukemia traditionally have been treated with a
standard myeloid protocol, with a wide variation in prognosis between M6a, which
has a similar prognosis to acute myelogenous leukemias, and M6b, with an
extremely poor outcome despite aggressive therapy. Forty-eight archival cases of
acute erythroleukemia, subtypes M6a (the traditional FAB-M6), M6b (pure
erythroleukemia), and M6c (>30% myeloblasts and >30% pronormoblasts by FAB
exclusion criteria), were evaluated for multidrug resistance gene (MDR-1) status.
Findings were correlated with clinical course and karyotypes. Immunohistochemical
stain for the protein product of MDR-1, P-glycoprotein, was variably positive in
11 of 23 patients with M6a, as well as in all of the patients with M6b (strongly
positive) and M6c (weakly positive). P-glycoprotein expression positively
correlated with unfavorable cytogenetic aberrations, poor response to
chemotherapeutic agents, and short survival. Most significant was that P
glycoprotein expression demonstrated a negative additive effect on response to
treatment and prognosis with unfavorable cytogenetic anomalies. P-glycoprotein
expression and multiple cytogenetic anomalies most probably contribute to the
resistance to chemotherapy and poor survival characteristic of the patients with
M6b (mean survival, 3.15 +/- 4.2 mo) and M6c (mean survival, 10.5 +/- 12.7 mo).
Because patients with M6b and M6c have increased numbers of pronormoblasts in
their bone marrow and past chemotherapeutic attempts have failed, chemotherapy
directed at these cells is appropriate. Additional therapy directed toward the
MDR-1 gene and its protein product seems indicated from our findings.
PMID- 10786808
TI - Sinus histiocytosis with massive lymphadenopathy and malignant lymphoma involving
the same lymph node: a report of four cases and review of the literature.
AB - Sinus histiocytosis with massive lymphadenopathy (SHML), also known as Rosai
Dorfman disease, is a disorder of unknown cause. Rarely, patients with SHML also
have malignant lymphoma, usually involving anatomic sites different from those
involved by SHML We report four patients in whom SHML and malignant lymphoma were
identified in the same lymph node biopsy specimen. The SHML in each case was
present as a small focus, less than 1 cm. Immunohistochemical studies showed that
the abnormal histiocytes were positive for S-100 and negative for CD1a. The
malignant lymphomas included two cases of follicular lymphoma and two cases of
Hodgkin's disease, nodular lymphocyte predominant type. The presence of SHML in
these patients did not impact clinical decisions, and there was no evidence of
SHML elsewhere. Thus, the presence of focal SHML associated with malignant
lymphoma in these cases was an incidental histologic finding that seems not to
have had any clinical significance.
PMID- 10786810
TI - Comparison of oncostatin M expression in keratoacanthoma and squamous cell
carcinoma.
AB - Oncostatin M (OSM) is a 28-kDa glycoprotein, produced by stimulated macrophages
and T lymphocytes, that inhibits the proliferation and induces differentiation of
a number of different cell lines derived from solid tumors. To determine whether
keratoacanthoma (KA) is unique or a variant of squamous cell carcinoma (SCC), we
compared the immunohistochemical expression of OSM in the tumor cells and peri-
and intratumoral macrophages of 21 mature KAs, 7 regressing KAs, and 27 SCCs. An
inverse correlation was identified between OSM tumor labeling and the density of
OSM-labeled tumor-associated macrophages for KAs (r = -.4; P = .09). OSM tumor
expression was significantly more frequent and more intense in KAs than in SCCs
(95% versus 63%; P < .01). In contrast, the density of OSM-labeled macrophages
was significantly higher in SCCs compared with mature KAs (7/3 high power fields
versus 4/3 high power fields; P = .02). These OSM-positive macrophages were
predominantly located at the advancing, infiltrative margins of both neoplasms.
Regressing KAs demonstrated a decreased level of OSM tumor expression compared
with mature KAs (53% versus 95%; P = .001), but there was no difference in
density of OSM-labeled macrophages. Both the above differences and the
overlapping patterns of OSM expression suggest that KAs are a variant of SCC
where OSM, possibly as an autocrine factor, may mediate KA's overwhelming but not
absolute tendency to involute.
PMID- 10786812
TI - Immunohistochemical detection of Bcl-2 in Kaposi's sarcoma lesions varies
according to histopathologic stage, whereas expression of Bcl-x and Mcl-1 differs
according to human immunodeficiency virus serologic status of patients.
AB - Expression of Bcl-2, Bcl-x, and Mcl-1 was immunohistochemically evaluated in 33
cases of Kaposi's sarcoma (KS) of the skin. Of these, classic KS (C-KS) accounted
for 17 cases (10 in plaque stage and 7 in tumor stage) and acquired
immunodeficiency syndrome-associated KS (AIDS-KS) accounted for 16 cases (8 in
plaque stage and 8 in tumor stage). In both C-KS and AIDS-KS, Bcl-2
immunoreaction correlated with progression stage, its average score intensity
being more than 2-fold in tumors than in plaques. In contrast, Bcl-x and Mcl-1
staining intensity was unrelated to progression stage but was dependent on human
immunodeficiency virus infection status. Thus, whereas Bcl-x expression was
stronger in C-KS cases, Mcl-1 immunostaining was more intense in AIDS-KS
instances. These findings indicate that in cutaneous KS, some Bcl-2 family
proteins exhibit differential expressions that are dependent on either
progression stage or human immunodeficiency virus infection status.
PMID- 10786811
TI - FGF4 and INT2 oncogenes are amplified and expressed in Kaposi's sarcoma.
AB - Kaposi's sarcoma (KS) is a vascular tumor, the pathogenesis of which has been
suggested to include human herpesvirus 8 (HHV-8) as well as various cytokines and
growth factors. Very little is known about cytogenetic and molecular genetic
changes in KS. We studied DNA copy number changes in KS and found a recurrent
gain at 11q13. We then analyzed the amplification and expression status of two
known oncogenes, FGF4 and INT2, residing at 11q13. Comparative genomic
hybridization, interphase fluorescence in situ hybridization with yeast
artificial chromosome probes containing FGF4 and INT2, and immunoperoxidase
immunostaining with anti-FGF4 and -INT2 antibodies were used on 12 KS samples.
All samples tested were shown by polymerase chain reaction to be HHV-8 positive.
A recurrent gain at 11q13 was shown by comparative genomic hybridization in 4 of
10 cases studied. Of six cases studied by interphase fluorescence in situ
hybridization, four showed a 3- to 4-fold amplification with the probes
containing FGF4 and INT2. Expression of FGF4 and INT2 was found in nine and three
cases, respectively, of nine studied. Amplification and expression of these genes
is particularly interesting in the context of oncovirus involvement, because INT2
is a homolog of mouse int2 which causes mammary carcinoma in mice when activated
by integration of retrovirus mouse mammary tumor virus. This raises the question
of whether HHV-8 represents an integrating oncovirus that causes amplification
and activation of genomic oncogenes in humans.
PMID- 10786809
TI - Ubiquitin immunochemistry as a diagnostic aid for community pathologists
evaluating patients who have dementia.
AB - Alzheimer's disease is the most common cause of dementia It is associated with
genetic risk factors and at least three autosomal dominant mutations. Community
pathologists are frequently asked by families to evaluate autopsy material for
Alzheimer's disease. Neuropathologic diagnosis is based on technically difficult
silver impregnation stains that may not be readily available to community-based
pathologists. Because immunohistochemical techniques are more widely accessible,
we evaluated the practical utility of using a single immunohistochemical stain
for diagnosing Alzheimer's disease. The ubiquitin antigen was selected because of
its presence in morphologically distinct deposits characteristic of several
neurodegenerative diseases. Paraffin blocks were obtained from the Bryan
Alzheimer's Disease Research Center Brain Bank, a repository of approximately 900
brains. Tissues from 16 individuals who exhibited the entire range of Alzheimer's
type neuropathology were selected. Ubiquitin immunostains, evaluated blindly and
independently by four pathologists ranging from first-year resident trainee to
experienced neuropathologist, reliably stained both neuritic plaques and
neurofibrillary tangles essential for diagnosing and staging Alzheimer's disease.
Nondemented controls with early Alzheimer's-type changes were easily
distinguished from cases of definitive Alzheimer's disease. The stains also
highlighted characteristic inclusions of Parkinson's disease or Lewy body
dementia Ubiquitin immunohistochemistry is a reliable, reproducible, and readily
available diagnostic aid for distinguishing Alzheimer's disease from other causes
of dementia.
PMID- 10786814
TI - Immunoreactivity of MIC2 (CD99) in acute myelogenous leukemia and related
diseases.
AB - MIC2 is characteristically expressed in lymphoblastic lesions and
Ewing's/primitive neuroectodermal tumor sarcomas. Although MIC2 has recently been
reported in chloroma and rare terminal deoxynucleotidyl transferase-positive
acute myelogenous leukemia (AML), the incidence and the significance of MIC2
(CD99) immunoreactivity in myeloid lesions is not clear. In this study, we
evaluated MIC2 positivity in a variety of myeloid diseases and normal marrow to
determine its incidence and distribution in myeloid diseases; its correlation
with flow cytometric and cytogenetic data in AML; and its association with
leukemic transformation, relapse, and chloroma formation. Paraffin sections of 11
chloromas and 94 bone marrow core biopsies from 66 patients were stained with
CD99 monoclonal antibody 12E7. Of 94 bone marrow core biopsies, there were 30 AML
(fragment antigen binding M0 to M6), 23 remissions, 5 relapses, 12
myeloproliferative disorders, 13 myelodysplastic syndromes, and 11 normal marrows
from patients who did not have leukemia. CD99 immunoreactivity was evaluated with
light microscopy. MIC2 expression was seen in leukemic blasts in 6 of 11
chloromas (55%) and 13 of 30 AML (43%) but rarely in myeloproliferative
disorders, myelodysplastic syndromes, remission, and normal marrow. CD99 tended
to be positive in M1-, M3-, and HLA-Dr-negative AML and negative in AML with
relapse. MIC2 expression did not correlate with the karyotype independent of
French-American-British Cooperative Group classification and the disease
remission or occurrence of chloroma in AML. We concluded that MIC2 is commonly
expressed in leukemic blasts of AML and is not predictive of leukemic
transformation from myeloproliferative disorders and myelodysplastic syndromes or
chloroma formation. Caution should be taken when using MIC2 as a marker for
Ewing's sarcoma/ primitive neuroectodermal tumor or lymphoblastic lymphoma on
paraffin sections of either soft tissue or bone marrow specimens.
PMID- 10786813
TI - Immunohistochemical analysis of CD30-positive lymphoproliferative disorders for
expression of CD95 and CD95L.
AB - Primary cutaneous (PC) CD30-positive large cell lymphoma and lymphomatoid
papulosis (LyP) represent the spectrum of PC CD30-positive lymphoproliferative
disorders (LPDs) associated with a favorable prognosis. Noncutaneous CD30
positive anaplastic large cell lymphoma (ALCL), although morphologically similar
to PC CD30-positive LPDs, seems to be a biologically distinct entity. Cell lines
derived from noncutaneous ALCL express CD95 and undergo CD95-induced apoptosis.
Little is known about expression or function of CD95/CD95L in cutaneous lesions.
We examined a series of PC CD30-positive LPDs and noncutaneous ALCL for
expression of CD95/CD95L to investigate possible differences between these
histologically similar but biologically distinct entities. Paraffin-embedded,
formalin-fixed tissue sections from 25 cases of CD30-positive LPDs (10
noncutaneous ALCL, 15 PC CD30-positive LPDs) were immunostained for CD3, CD20
(L26), CD43 (Leu22), CD30 (BerH2), anaplastic lymphoma kinase (ALK-1), CD95, and
CD95L (C-33). One hundred large atypical cells and 100 small lymphocytes were
counted to determine the percentage of CD95/ CD95L-positive cells. Statistical
analysis using the Mann-Whitney U test was performed. CD95 expression was
slightly higher in the large atypical cells of noncutaneous ALCL compared with PC
CD30-positive LPDs (median, 100% versus 94%; P = .003) because of the lower
expression of CD95 in LyP. CD95L expression was higher in the surrounding small
lymphocytes in PC CD30-positive LPDs (median, 3% versus 13%; P = .002).
Expression of CD95 in the small lymphocytes and CD95L in the large atypical cells
was not significantly different. These results support the biologic distinction
between cutaneous and noncutaneous CD30-positive LPDs and may have implications
in the differing clinical behavior of these entities. Further study of expression
and function of apoptosis-related proteins in these entities is warranted.
PMID- 10786815
TI - Immunoreactivity with the anti-MAGE antibody 57B in malignant melanoma: frequency
of expression and correlation with prognostic parameters.
AB - The melanoma-associated antigen (MAGE) family consists of a number of antigens
initially recognized by cytotoxic T lymphocytes, which are currently being
investigated for immunotherapy of patients with metastatic melanoma and other
tumor types. Expression of MAGE mRNA in melanocytic tumors is said to be
restricted to invasive malignant tumors and absent in nevi. Recently, a
monoclonal antibody (57B) has become available to examine MAGE protein expression
in archival material. In this study, we performed immunohistochemical analysis on
132 melanocytic nevi and 205 melanomas (85 primary cutaneous melanomas and 120
metastatic tumors) to determine the frequency of MAGE expression and to explore a
potential correlation with various prognostic parameters. None of the melanocytic
nevi and none of the 20 in situ melanomas was immunopositive with the antibody
57B. Immunoreactivity was present in 17 of 65 (26%) primary invasive melanomas of
the skin and in 30 of 120 (25%) metastatic tumors. Positive immunostaining did
not correlate with tumor stage (P = .66), Breslow thickness (P = .39), Clark
level (P = .5), or the histologic type of melanoma (P = .23) but was associated
with a brisk infiltrate of lymphocytes involving the vertical growth phase of
melanomas (P = .01). Because tumor-infiltrating lymphocytes in melanoma are
associated with longer survival, our findings suggest a potential prognostic role
for MAGE. Furthermore, the seeming restriction of immunopositivity to invasive
malignant tumors suggests a potential diagnostic role for the antibody 57B in
confirming the malignant potential of a melanocytic tumor.
PMID- 10786816
TI - Malignant ovarian sex cord tumor with annular tubules in a patient with Peutz
Jeghers syndrome: a case report.
AB - The majority of ovarian sex cord tumors with annular tubules (SCTAT) are benign
neoplasms that arise sporadically. In patients who have Peutz-Jeghers syndrome
(PJS), ovarian SCTAT is often an incidental finding. Malignant behavior in SCTAT
has heretofore been reported only in sporadic cases. We report a case of
bilateral, malignant SCTAT developing in a 47-year-old woman who had PJS,
originally diagnosed as adenocarcinoma on cervicovaginal cytology. Cervicovaginal
and peritoneal fluid cytologic preparations were characterized by pseudopapillary
clusters and three-dimensional tubes of tumor cells with scanty cytoplasm and
high nuclear: cytoplasmic ratio. Examination of surgical resection specimens
revealed bilateral, solid ovarian tumors composed of simple and complex annular
tubules with hyaline cores, typical of SCTAT. Tumor emboli were present within
salpingeal lymphovascular spaces and in both right and left pelvic lymph nodes.
Flow cytometry of tumor cells demonstrated a diploid phenotype. This case
represents the first documented example of bilateral, malignant SCTAT arising in
a patient who had PJS, presenting with an atypical cervicovaginal smear.
PMID- 10786817
TI - Role of glycosylation in function of follicle-stimulating hormone.
AB - The oligosaccharide structures of heterodimeric glycoprotein hormones, such as
follicle-stimulating hormone (FSH), have been shown to play an important role in
the biosynthesis, secretion, metabolic fate, and regulation of potency of the
hormone. The oligosaccharide structures attached to each subunit of the protein
seem to exhibit distinct roles in some of these functions. Glycans attached to
the alpha-subunit are critical for dimer assembly, integrity, and secretion, as
well as for signal transduction; although beta-subunit glycans are also important
for dimer assembly and secretion, they play a crucial role in clearance of the
dimer from the circulation. Alternative glycosylation on FSH and other
glycoprotein hormones not only may affect the metabolic clearance and net in vivo
biopotency of the hormone, but also offers the interesting possibility that some
glycosylation variants of the hormone may provoke differential or even unique
effects at the target cell level. Glycosylation of FSH is regulated by
hypothalamic and/or end products from the glands under the control of this
hormone. In particular, estrogens regulate terminal sialylation and thus some
functional properties of the gonadotropin influenced by sialic acid. Through
these extrapituitary inputs, the gonadotroph may regulate not only the amount but
also the intensity of the gonadotropin signal to be secreted by the pituitary in
a given physiological condition.
PMID- 10786819
TI - Effect of okadaic acid and calyculin-A, two protein phosphatase inhibitors, on
thyrotropin-stimulated triiodothyronine secretion in cultured sheep thyroid
cells.
AB - We have studied the effect of two protein phosphatase inhibitors on thyrotropin
(TSH)-stimulated triiodothyronine (T3) production by sheep thyroid cells grown in
primary culture. Incubation of sheep thyrocytes with okadaic acid (OA) and
calyculin-A (CL-A), two potent inhibitors of type 1 (PP1) and type 2A (PP2A)
protein phosphatases, resulted in an increase of TSH-stimulated T3 production.
This effect was detected using concentrations as low as 0.1 pM with OA and 1 fM
with CL-A. An inhibitory effect on T3 production, due to cellular death, was
observed with 6 nM OA and 1 nM CL-A. In the absence of TSH, OA or CL-A had no
effect on T3 production by thyrocytes. Forskoline (10 microM), an activator of
adenylate cyclase, increased the basal and TSH-stimulated T3 release by sheep
thyroid cells; this effect was increased by OA in cells grown in the basal state
but not in the presence of TSH. These results suggest that the marine toxins OA
and CL-A, two potent inhibitors of PP-1 and PP-2A, have significant stimulatory
effects on T3 secretion promoted by TSH and FK. These observations indicate that
these proteins could be important mediators of thyroid hormone production.
PMID- 10786818
TI - Estrogen action in the regulation of cell proliferation, cell survival, and
tumorigenesis in the rat anterior pituitary gland.
AB - Estrogens act as important regulators of cell proliferation, cell survival, and
differentiation in a variety of organ systems and tissues and have been
implicated in the etiology of a variety of malignant cancers and benign tumors.
The anterior pituitary gland of the rat provides an excellent model for the study
of estrogen action in the regulation of cell proliferation and survival.
Estrogens stimulate proliferation of the prolactin (PRL)-producing lactotroph and
enhance lactotroph survival. Through these actions on lactotroph proliferation
and survival, estrogens induce or contribute to the development of PRL-producing
pituitary tumors in several rat strains. Data from our laboratory and others
indicate that estrogen-induced pituitary growth is rat strain specific and
segregates as a quantitative genetic trait in crosses between different rat
strains. The purpose of this review is to summarize current knowledge pertaining
to estrogen action in the regulation of cell proliferation, cell survival, and
tumorigenesis in the anterior pituitary gland of the rat species, Rattus
norvegicus, and to illustrate the advantages of the rat pituitary gland as a
model for elucidating the mechanisms through which estrogens regulate these
processes.
PMID- 10786821
TI - Stimulation of anterior pituitary galanin and prolactin gene expression in
suckling rats.
AB - Recent evidence suggests that galanin may regulate prolactin (PRL) secretion
during lactation. In this article, we describe the regulation of anterior
pituitary galanin and PRL gene expression during pregnancy and after parturition
in the rat. Expression of galanin and PRL in the anterior pituitary were
significantly higher at d 20 of pregnancy compared to diestrus. One day after
parturition, galanin mRNA levels increased a further 4.5-fold. This post partum
increase in gene expression was not observed for PRL. The increase in galanin
gene expression was maintained above the diestrous level for at least 10 d after
parturition. PRL mRNA expression, on the other hand, was largely unchanged after
parturition. Although the increase in galanin gene expression 1 d after
parturition was independent of suckling, subsequently, galanin gene expression
was significantly higher in nursing mothers. Anterior pituitary galanin gene
expression was 12-fold higher in nursing mothers compared with those that were
not, 3 d after parturition. Similarly, PRL gene expression was significantly
lower in mothers who were not suckling their pups 3 d after parturition.
Initiation of suckling alone was insufficient to stimulate galanin and PRL
expression. Despite suckling for 2 d, removal of the suckling stimulus
subsequently resulted in a rapid decrease in galanin gene expression. Hence, the
stimulatory effect of suckling on galanin expression requires a sustained
suckling stimulus. In conclusion, the data support the hypothesis that anterior
pituitary galanin plays an important role during lactation, likely acting to
amplify lactotroph stimulation through paracrine and autocrine mechanisms.
PMID- 10786820
TI - Transforming growth factor-beta1 modulates chondrocyte responsiveness to 17beta
estradiol.
AB - This study examined the interrelationship between transforming growth factor
beta1 (TGF-beta1) and 17beta-estradiol (E2) in the regulation of growth plate
chondrocytes. To determine whether TGF-beta1 modulates chondrocyte response to
E2, we used cells isolated from the resting zone (RC) and growth zone (GC) of
costochondral cartilage. Confluent, fourth-passage cultures were pretreated with
rhTGF-beta1 for 24 h, followed by treatment with E2 for 24 h. The effect of TGF
beta1 and E2 alone, or the sequential combination, were examined by measuring
[3H]-thymidine incorporation (proliferation), alkaline phosphatase (AP) specific
activity (differentiation), and [35S]-sulfate incorporation (matrix synthesis).
TGF-beta1 alone increased [3H]-thymidine incorporation in both female and male RC
and GC cells, but E2 affected this parameter only in RC cells, causing a dose
dependent decrease. At the highest concentration of TGF-beta1 and E2, [3H]
thymidine incorporation in female GC cells was the same as seen in untreated
control cultures. In male GC cells, [3H]-thymidine incorporation in cultures
treated with TGF-beta1 and E2 exhibited a comparable increase, as was seen in
cultures treated with TGF-beta1 alone. TGF-beta1 caused a biphasic stimulation in
AP that was maximal at 0.22 ng/mL, in both female and male RC and GC cells. E2,
however, affected only female cells. Whereas the effect of TGF-beta1 predominated
in RC and GC male cells, the biphasic stimulation caused by E2, maximal at 109 M,
predominated in female RC cells. In female GC cells, however, TGF-beta1 caused a
synergistic response, resulting in enhanced AP specific activity in cultures
pretreated with 0.22 ng/mL of TGF-beta1 and 10(-8) M E2. TGF-beta1 alone caused
dose-dependent increases in [35S]-sulfate incorporation in female RC and GC
cells, as well as in male GC cells, but had no effect on male RC cells. E2
affected only female cells. TGF-beta1 potentiated the effect of E2 on this
parameter, resulting in synergistic increases in the female cells. This is the
first demonstration of a gender-specific response to TGF-beta1 in chondrocytes.
These results suggest that chondrocyte response to a systemic hormone such as E2
can be modulated by local regulatory agents such as TGF-beta1.
PMID- 10786822
TI - Ovarian steroid action on tryptophan hydroxylase protein and serotonin compared
to localization of ovarian steroid receptors in midbrain of guinea pigs.
AB - The effect of estrogen (E) and progesterone (P) on the protein expression of the
rate-limiting enzyme in serotonin synthesis, tryptophan hydroxylase (TPH), and
the level of serotonin in the hypothalamic terminal field was examined in guinea
pigs. In addition, we questioned whether serotonin neurons of guinea pigs contain
ovarian steroid receptors (estrogen receptoralpha[ERalpha], estrogen receptor
beta[ERbeta], progestin receptors [PRs]) that could directly mediate the actions
of E or P. Western blot and densitometric analysis for TPH were used on raphe
extracts from untreated-ovariectomized (OVX), OVX-E-treated (28 d), and OVX-E+P
treated (14 d E+14 d E+P) guinea pigs. The medial basal hypothalami from the same
animals were extracted and subjected to high-performance liquid chromatography
analysis for serotonin, dopamine, 5-hydroxyindole acetic acid, and homovanillic
acid. The brains from other animals treated in an identical manner were perfusion
fixed and examined for the colocalization of ERalpha plus serotonin and PR plus
serotonin with double immunohistochemistry or for expression of ERbeta mRNA with
in situ hybridization. E and E+P treatment significantly increased TPH protein
levels compared to the untreated control group (p < 0.05), but TPH levels were
similar in the E and E+P-treated groups. By contrast, serotonin
(nanogram/milligram of protein) in the hypothalamus was significantly increased
by E+P treatment, but not by E alone. Neither ERalpha nor PR proteins were
detected within serotonin neurons of the guinea pig raphe nucleus. However,
ERbeta mRNA was expressed in the dorsal raphe. In summary, E alone increased TPH
protein expression and the addition of P had no further effect, whereas E+P
increased hypothalamic serotonin and E alone had no effect. The localization of
ERbeta, but not ERalpha or PR, in the dorsal raphe nucleus suggests that E acting
via ERbeta within serotonin neurons increases expression of TPH, but that P
acting via other neurons and transsynaptic stimulation may effect changes in TPH
enzymatic activity, which in turn, would lead to an increase in serotonin
synthesis.
PMID- 10786825
TI - Reevaluation of the determinants of tyrosine sulfation.
AB - The posttranslational sulfation of tyrosine has been thought to be initiated by
the recognition of specific consensus features by the sulfating enzyme
tyrosylprotein sulfotransferase (TPST). However, using these recognition features
to identify new tyrosine sulfation sites misses recently characterized sites that
lack these features. Rigorous analysis of the amino acids surrounding the target
tyrosine using the position-specific scoring matrix (PSSM) demonstrates that a
consensus sequence does not contain all the information necessary to predict
tyrosine sulfation. Instead, accurate prediction requires consideration of all
residues within five amino acids on either side of the target tyrosine. These
results support the notion that secondary structure is the major determinant of
sulfation and that other residues within the sulfation site can compensate for
deviations from commonly observed features. This view implies that specific
consensus features are not critical for TPST substrate recognition but that TPST
may instead broadly recognize any sufficiently exposed tyrosine residue.
PMID- 10786823
TI - Rat ovarian interleukin-1alpha: interleukin-1-dependent in vitro expression.
AB - Evidence exists supporting the possibility that intraovarian interleukin-1 (IL-1)
may play an intermediary role in the periovulatory cascade. Although the
existence of a mammalian intraovarian IL-1 system has been convincingly
demonstrated, most efforts have focused on the possibility that the mammalian
ovary is a site of IL-1b production, reception, and action. The objective of this
study was to explore the possibility of ovarian IL-1a expression, characterize
its pattern of expression by cultured ovarian cells, and study its hormonal
regulation. The basal in vitro expression of IL-1a by cultured whole ovarian
dispersates from immature rats increased spontaneously, reaching a peak (sixfold
increase over untreated controls) at 4 h. Treatment with an IL-1 receptor
antagonist (IL-1RA), human chorionic gonadorropin, or IL-1b failed to attenuate
the initial 4-h burst of IL-1a expression. By contrast, treatment of whole
ovarian dispersates with IL-1b for 48 h resulted in significant upregulation of
IL-1a transcripts (60-fold increase). This IL-1b effect was completely blocked by
cotreatment with IL-1RA, thereby suggesting mediation via a specific IL-1
receptor. The IL-1b effect proved to be protein biosynthesis and eicosanoid
dependent, nitric oxide independent, and relatively specific in that it was not
reproduced by a select series of other granulosa cell agonists.
PMID- 10786826
TI - Possible participation of an islet B-cell calcium-sensing receptor in insulin
release.
AB - The calcium-sensing receptor gene was recently shown to be expressed in rat
pancreatic islets and purified islet B-cells. In this study, we investigated the
possible role of this receptor in the regulation of insulin release from isolated
rat pancreatic islets. Poly-L-arginine (0.2-0.3 microM) and poly-L-lysine (0.03
0.1 microM) increased insulin output evoked by D-glucose (8.3 mM). This positive
effect faded out at higher concentrations of the basic peptides. Likewise, the
release of insulin evoked by 8.3 mM D-glucose was significantly lower at high
(1.0 mM) than low (0.05-0.1 mM) concentrations of neomycin. The insulinotropic
action of Ba2+ in Ca2+-deprived islets was potentiated in rats pretreated with
pertussis toxin. However, Gd3+ inhibited insulin release evoked by D-glucose in
islets prepared from normal rats or animals pretreated with pertussis toxin and
incubated in the absence or presence of either theophylline or forskolin. Gd3+
(0.3 mM) failed to affect effluent radioactivity from islets prelabeled with myo
[2-3H]inositol and cyclic AMP net production in islets incubated in the absence
or presence of forskolin. Gd3+ decreased, however, 45Ca efflux from prelabeled
islets perifused in the absence or presence of extracellular Ca2+. It is
speculated that a negative insulinotropic action mediated by the calcium-sensing
receptor, and possibly attributable to a fall in cytosolic Ca2+ concentration,
may prevent excessive insulin secretion in pathological situations of
hypercalcemia.
PMID- 10786827
TI - Characterization of 11beta-hydroxysteroid dehydrogenase activities in the renal
cell line LLC-PK1: evidence for a third isoform?
AB - We studied 11beta-hydroxysteroid dehydrogenase activities in the renal cell line
LLC-PK1 and the effects of different steroids on them. Cortisol was oxidized in
the presence of NAD as well as NADP, reflecting the presence of two different
11beta-HSD forms. Enzyme kinetics for cortisol 11beta-oxidation were: Vmax = 5.9
pmol/(min x mg), Km = 0.2 microM with NAD, and Vmax = 4.5 pmol/(min x mg), Km =
1.0 microM with NADP. Interestingly, no reverse reaction was observed when using
cortisone and NADPH as substrate and cosubstrate, respectively. Exposure of cells
to a variety of steroids had different effects on cortisol 11beta-oxidation rates
with NADP compared to those with NAD. Dexamethasone initially (3-60 min of
exposure) decreased the NAD-dependent 11beta-HSD activity to about 60%, which was
no longer evident after 2 h or longer. By contrast, the 11beta-oxidation of
cortisol with NADP increased by dexamethasone treatment of the cells, after a
lagtime of about 2 h, and this effect was still evident after 32 h. The increase
of 11beta-HSD activity with NADP by dexamethasone was concentration dependent
(estimated EC50:125 nM). The antiglucocorticoid RU486 did not antagonize
dexamethasone induction. Exposure of cells for 19 h to 1 microM cortisol,
cortisone, progesterone, and estradiol also increased NADP-dependent cortisol
11beta-oxidation, but had no effect on the NAD-dependent 11beta-HSD activity.
Immunoblot and reverse transcriptase-polymerase chain reaction experiments failed
to detect any 11beta-HSD 1 protein or mRNA in these cells. Our observations
suggest that in LLC-PK1 cells, two forms of 11beta-HSD exist, which differ in
cosubstrate dependency, kinetics for cortisol, and modulation by steroids.
Whereas the NAD-dependent form seems identical to renal 11beta-HSD 2, the NADP
dependent 11beta-HSD possibly resembles an as yet unknown third isoform.
PMID- 10786824
TI - Impact and reversibility of chronic ethanol feeding on the reproductive axis in
the peripubertal male rat.
AB - Teenage drinking continues to be a major problem in the United States as well as
abroad. A significant depression in serum testosterone in adolescents who consume
EtOH has been well described. In the male rodent model, a similar fall in
testosterone has been reported, and prevention with the opiate blocker naltrexone
has been demonstrated. To explore further the impact of chronic EtOH exposure on
the reproductive axis in peripubertal rats, we designed this study specifically
to define whether or not there was recovery after abstinence by examining
reproductive hormones and their genes during and after EtOH exposure.
Peripubertal male rats 35 d old were fed an EtOH-containing diet or a calorically
matched control diet for 60 d. A third group was fed the control liquid diet ab
libitum. EtOH was then withdrawn and all animals were fed standard rat chow and
water ad libitum for an additional 3 mo. The EtOH-imbibing animals were found
consistently to weigh less than their pair-fed mates and liquid diet ad libitum
animals. Serum testosterone levels and testicular weights were significantly
decreased by EtOH whereas serum estradiol levels were higher, suggesting enhanced
peripheral conversion by EtOH. Spermatogenesis, assessed by histological
parameters, was unaltered by EtOH. Serum luteinizing hormone levels were not
different among the groups. Hypothalamic luteinizing hormone-releasing hormone
mRNA levels were unaffected by EtOH. During the 3-mo recovery period, all the
changes reversed, with a significant increase noted in testosterone. All other
parameters remained the same among the groups. Thus, although chronic EtOH
exposure in the peripubertal age period results in significant reproductive
alterations, there is complete recovery on withdrawal.
PMID- 10786829
TI - Roles of testosterone in the growth of keratinocytes through bald frontal dermal
papilla cells.
AB - A coculture of dermal papilla cells (DPCs) from the bald frontal scalp of
stumptailed macaques with keratinocytes derived from human neonatal foreskin
revealed that testosterone inhibited keratinocyte proliferation, and that the
antiandrogen RU58841 abolished this response. This testosterone-induced
keratinocyte growth inhibition was not observed when either type of cells was
cultured alone. We also examined conditioned media from the coculture system and
demonstrated the identical testosterone-induced growth inhibition on
keratinocytes, and this inhibitory effect was conditioned media concentration
dependent. These results suggested that the testosterone-mediated suppression on
keratinocyte proliferation might proceed through some diffusible growth mediators
in conditioned media. Differential display reverse transcriptase polymerase chain
reaction allowed us to isolate several genes from frontal DPCs that can be either
suppressed or induced by testosterone. Supervillin, a membrane-associated, F
actin-binding protein, was identified as one of the testosterone downregulated
genes in frontal DPCs. Further characterization of these testosterone-target
genes may reveal the mechanism by which testosterone inhibits the growth of
follicular cells in androgenetic alopecia.
PMID- 10786828
TI - Skeletal resistance to 1,25-dihydroxyvitamin D3 in osteopetrotic rats.
AB - The osteopetrotic (op/op) rat mutation is a lethal mutation in which decreased
osteoclast function (bone resorption) coexists with markedly elevated serum
levels of 1 ,25-dihydroxyvitamin D3[1,25(OH)2D3]. Increased circulating levels of
1,25(OH)2D3 have been reported in other osteopetrotic animal mutations and in
some osteopetrotic children. This study examined the effects of 1,25(OH)2D3
infusions on serum and skeletal parameters in normal and mutant rats of op stock.
We also examined vitamin D receptor expression and binding in bone cells from op
normal and mutant animals. Four-week-old normal and mutant rats were infused
either with propylene glycol (used as controls) or with 12.5-125 ng of
1,25(OH)2D3/d using osmotic minipumps implanted subcutaneously for 1 wk. Sera
were analyzed for calcium, phosphorus, and 1,25(OH)2D3 levels. Histomorphometric
analyses of proximal tibiae from treated normal (50 ng/d) and op mutant (125
ng/d) rats and their vehicle-infused controls were performed. Normal animals
infused with 1,25(OH)2D3 exhibited a dose-dependent increase in serum calcium
levels. Histomorphometric analyses of metaphyseal bone within the primary
spongiosae region showed that 1,25(OH)2D3 increased osteoclast number with a
reduction in osteoblast surface associated with a decrease in growth plate
cartilage thickness. However, similar analyses on secondary spongiosae showed a
decrease in osteoclast number and surface associated with an anabolic response.
Op mutants infused with 1,25(OH)2D3 did not exhibit any change in serum calcium
levels or histomorphometric parameters related to growth plate cartilage and
metaphyseal bone compared with mutant controls. Vitamin D mRNA and protein levels
were increased twoto threefold in op mutants compared to age-matched normal rats.
However, binding affinity of 1,25(OH)2D3 to its receptor was similar between op
mutant and normal animals. High dose calcitriol therapy, under the conditions and
period of treatment used in this study, failed to stimulate bone turnover in op
rats, suggesting that they are resistant to the skeletal effects of 1,25(OH)2D3.
The failure of osteoclast activation in response to 1,25(OH)2D3 treatment may be
associated with osteoblast incompetence in this mutation.
PMID- 10786830
TI - New animal models for Parkinson's disease.
PMID- 10786831
TI - Getting newly synthesized proteins into shape.
PMID- 10786833
TI - HIV-1 genome nuclear import is mediated by a central DNA flap.
AB - HIV-1 and other lentiviruses have the unique property among retroviruses to
replicate in nondividing cells. This property relies on the use of a nuclear
import pathway enabling the viral DNA to cross the nuclear membrane of the host
cell. In HIV-1 reverse transcription, a central strand displacement event
consecutive to central initiation and termination of plus strand synthesis
creates a plus strand overlap: the central DNA flap. We show here that the
central DNA flap acts as a cis-determinant of HIV-1 DNA nuclear import. Wild-type
viral linear DNA is almost entirely imported into the nucleus where it integrates
or circularizes. In contrast, mutant viral DNA, which lacks the DNA flap,
accumulates in infected cells as unintegrated linear DNA, at the vicinity of the
nuclear membrane. Consistently, HIV-1 vectors devoid of DNA flap exhibit a strong
defect of nuclear import, which can be corrected to wild-type levels by
reinsertion of the DNA flap sequence.
PMID- 10786832
TI - Transcription-coupled repair of 8-oxoguanine: requirement for XPG, TFIIH, and CSB
and implications for Cockayne syndrome.
AB - Analysis of transcription-coupled repair (TCR) of oxidative lesions here reveals
strand-specific removal of 8-oxo-guanine (8-oxoG) and thymine glycol both in
normal human cells and xeroderma pigmentosum (XP) cells defective in nucleotide
excision repair. In contrast, Cockayne syndrome (CS) cells including CS-B, XP
B/CS, XP-D/CS, and XP-G/CS not only lack TCR but cannot remove 8-oxoG in a
transcribed sequence, despite its proficient repair when not transcribed. The XP
G/CS defect uniquely slows lesion removal in nontranscribed sequences. Defective
TCR leads to a mutation frequency at 8-oxoG of 30%-40% compared to the normal 1%
4%. Surprisingly, unrepaired 8-oxoG blocks transcription by RNA polymerase II.
These data imply that TCR is required for polymerase release to allow repair and
that CS results from defects in TCR of oxidative lesions.
PMID- 10786834
TI - PHAX, a mediator of U snRNA nuclear export whose activity is regulated by
phosphorylation.
AB - In metazoa, assembly of spliceosomal U snRNPs requires nuclear export of U snRNA
precursors. Export depends upon the RNA cap structure, nuclear cap-binding
complex (CBC), the export receptor CRM1/Xpo1, and RanGTP. These components are
however insufficient to support U snRNA export. We identify PHAX (phosphorylated
adaptor for RNA export) as the additional factor required for U snRNA export
complex assembly in vitro. In vivo, PHAX is required for U snRNA export but not
for CRM1-mediated export in general. PHAX is phosphorylated in the nucleus and
then exported with RNA to the cytoplasm, where it is dephosphorylated. PHAX
phosphorylation is essential for export complex assembly while its
dephosphorylation causes export complex disassembly. The compartmentalized PHAX
phosphorylation cycle can contribute to the directionality of export.
PMID- 10786835
TI - Structure of TPR domain-peptide complexes: critical elements in the assembly of
the Hsp70-Hsp90 multichaperone machine.
AB - The adaptor protein Hop mediates the association of the molecular chaperones
Hsp70 and Hsp90. The TPR1 domain of Hop specifically recognizes the C-terminal
heptapeptide of Hsp70 while the TPR2A domain binds the C-terminal pentapeptide of
Hsp90. Both sequences end with the motif EEVD. The crystal structures of the TPR
peptide complexes show the peptides in an extended conformation, spanning a
groove in the TPR domains. Peptide binding is mediated by electrostatic
interactions with the EEVD motif, with the C-terminal aspartate acting as a two
carboxylate anchor, and by hydrophobic interactions with residues upstream of
EEVD. The hydrophobic contacts with the peptide are critical for specificity.
These results explain how TPR domains participate in the ordered assembly of
Hsp70-Hsp90 multichaperone complexes.
PMID- 10786836
TI - Pachytene exit controlled by reversal of Mek1-dependent phosphorylation.
AB - During yeast meiosis, a checkpoint prevents exit from pachytene in response to
defects in meiotic recombination and chromosome synapsis. This pachytene
checkpoint requires two meiotic chromosomal proteins, Red1 and Mek1; Mek1 is a
kinase that phosphorylates Red1. In mutants that undergo checkpoint-mediated
pachytene arrest, Mek1 is active and Red1 remains phosphorylated. Activation of
Mek1 requires the initiation of meiotic recombination and certain DNA damage
checkpoint proteins. Mek1 kinase activity and checkpoint-induced pachytene arrest
are counteracted by protein phosphatase type 1 (Glc7). Glc7 coimmunoprecipitates
with Red1, colocalizes with Red1 on chromosomes, and dephosphorylates Red1 in
vitro. We speculate that phosphorylated Red1 prevents exit from pachytene and
that completion of meiotic recombination triggers Glc7-dependent
dephosphorylation of Red1.
PMID- 10786837
TI - A kaiC-interacting sensory histidine kinase, SasA, necessary to sustain robust
circadian oscillation in cyanobacteria.
AB - Both regulated expression of the clock genes kaiA, kaiB, and kaiC and
interactions among the Kai proteins are proposed to be important for circadian
function in the cyanobacterium Synechococcus sp. strain PCC 7942. We have
identified the histidine kinase SasA as a KaiC-interacting protein. SasA contains
a KaiB-like sensory domain, which appears sufficient for interaction with KaiC.
Disruption of the sasA gene lowered kaiBC expression and dramatically reduced
amplitude of the kai expression rhythms while shortening the period. Accordingly,
sasA disruption attenuated circadian expression patterns of all tested genes,
some of which became arrhythmic. Continuous sasA overexpression eliminated
circadian rhythms, whereas temporal overexpression changed the phase of kaiBC
expression rhythm. Thus, SasA is a close associate of the cyanobacterial clock
that is necessary to sustain robust circadian rhythms.
PMID- 10786838
TI - Evolutionary and functional aspects of C-to-U editing at position 28 of
tRNA(Cys)(GCA) in plant mitochondria.
PMID- 10786839
TI - RNA-ligand chemistry: a testable source for the genetic code.
AB - In the genetic code, triplet codons and amino acids can be shown to be related by
chemical principles. Such chemical regularities could be created either during
the code's origin or during later evolution. One such chemical principle can now
be shown experimentally. Natural or particularly selected RNA binding sites for
at least three disparate amino acids (arginine, isoleucine, and tyrosine) are
enriched in codons for the cognate amino acid. Currently, in 517 total
nucleotides, binding sites contain 2.4-fold more codon sequences than surrounding
nucleotides. The aggregate probability of this enrichment is 10(-7) to 10(-8),
had codons and binding site sequences been independent. Thus, at least some
primordial coding assignments appear to have exploited triplets from amino acid
binding sites as codons.
PMID- 10786840
TI - The scene of a frozen accident.
AB - It has been suggested that in vitro selection experiments can provide information
not only on what might have occurred during the evolution of the RNA world, but
can in fact yield insights into particular features of the RNA world. In
particular, it has been suggested that the sequences of anti-amino acid aptamers
can provide clues to the origin of the genetic code, and that there is a
statistically significant association between motifs found in aptamers and
codons. We argue that the suggested connections between modern motifs and ancient
sequences are logically tenuous, and show that there is no statistically
meaningful association between motifs found in aptamers and codons.
PMID- 10786841
TI - Guilt by association: the arginine case revisited.
AB - If the genetic code arose in an RNA world, present codon assignments may reflect
primordial RNA-amino acid affinities. Whether aptamers selected from random pools
to bind free amino acids do so using the cognate codons at their binding sites
has been controversial. Here we defend and extend our previous analysis of
arginine binding sites, and propose a model for the maintenance of codon-amino
acid interactions through the evolution of amino acids from ribozyme cofactors
into the building blocks of proteins.
PMID- 10786842
TI - Helix P4 is a divalent metal ion binding site in the conserved core of the
ribonuclease P ribozyme.
AB - The ribonuclease P ribozyme (RNase P RNA), like other large ribozymes, requires
magnesium ions for folding and catalytic function; however, specific sites of
metal ion coordination in RNase P RNA are not well defined. To identify and
characterize individual nucleotide functional groups in the RNase P ribozyme that
participate in catalytic function, we employed self-cleaving ribozyme-substrate
conjugates that facilitate measurement of the effects of individual functional
group modifications. The self-cleavage rates and pH dependence of two different
ribozyme-substrate conjugates were determined and found to be similar to the
single turnover kinetics of the native ribozyme. Using site-specific
phosphorothioate substitutions, we provide evidence for metal ion coordination at
the pro-Rp phosphate oxygen of A67, in the highly conserved helix P4, that was
previously suggested by modification-interference experiments. In addition, we
detect a new metal ion coordination site at the pro-Sp phosphate oxygen of A67.
These findings, in combination with the proximity of A67 to the pre-tRNA cleavage
site, support the conclusion that an important role of helix P4 in the RNase P
ribozyme is to position divalent metal ions that are required for catalysis.
PMID- 10786843
TI - Molecular recognition of amino acids by RNA aptamers: the evolution into an L
tyrosine binder of a dopamine-binding RNA motif.
AB - We report the evolution of an RNA aptamer to change its binding specificity. RNA
aptamers that bind the free amino acid tyrosine were in vitro selected from a
degenerate pool derived from a previously selected dopamine aptamer. Three
independent sequences bind tyrosine in solution, the winner of the selection
binding with a dissociation constant of 35 microM. Competitive affinity
chromatography with tyrosine-related ligands indicated that the selected aptamers
are highly L-stereo selective and also recognize L-tryptophan and L-dopa with
similar affinity. The binding site was localized by sequence comparison, analysis
of minimal boundaries, and structural probing upon ligand binding. Tyrosine
binding sites are characterized by the presence of both tyrosine (UAU and UAC)
and termination (UAG and UAA) triplets.
PMID- 10786845
TI - Chloroplast ribonuclease P does not utilize the ribozyme-type pre-tRNA cleavage
mechanism.
AB - The transfer RNA 5' maturation enzyme RNase P has been characterized in Bacteria,
Archaea, and Eukarya. The purified enzyme from all three kingdoms is a
ribonucleoprotein containing an essential RNA subunit; indeed, the RNA subunit of
bacterial RNase P RNA is the sole catalytic component. In contrast, the RNase P
activity isolated from spinach chloroplasts lacks an RNA component and appears to
function as a catalytic protein. Nonetheless, the chloroplast enzyme recognizes a
pre-tRNA substrate for E. coli RNase P and cleaves it as efficiently and
precisely as does the bacterial enzyme. To ascertain whether there are
differences in catalytic mechanism between an all-RNA and an all-protein RNase P,
we took advantage of the fact that phosphodiester bond selection and hydrolysis
by the E. coli RNase P ribozyme is directed by a Mg2+ ion coordinated to the
nonbridging pro-Rp oxygen of the scissile bond, and is blocked by sulfur
replacement of this oxygen. We therefore tested the ability of the chloroplast
enzyme to process a precursor tRNA containing this sulfur substitution. Partially
purified RNase P from spinach chloroplasts can accurately and efficiently process
phosphorothioate-substituted pre-tRNAs; cleavage occurs exclusively at the thio
containing scissile bond. The enzymatic throughput is fivefold slower, consistent
with a general chemical effect of the phosphorothioate substitution rather than
with a metal coordination deficiency. The chloroplast RNase P reaction mechanism
therefore does not involve a catalytic Mg2+ bonded to the pro-Rp phosphate
oxygen, and hence is distinct from the mechanism of the bacterial ribozyme RNase
P.
PMID- 10786848
TI - In vitro selection of novel RNA ligands that bind human cytomegalovirus and block
viral infection.
AB - Ribonuclease-resistant RNA molecules that bind to infectious human
cytomegalovirus (HCMV) were isolated in vitro from a pool of randomized sequences
after 16 cycles of selection and amplification. The two ligands (L13 and L19)
characterized exhibited high HCMV-binding affinity in vitro and effectively
inhibited viral infection in tissue culture. Their antiviral activity was also
specific as they only reacted with two different strains of HCMV but not with the
related herpes simplex virus 1 and human cells. These two ligands appeared to
function as antivirals by blocking viral entry. Ultraviolet (UV) crosslinking
studies suggested that L13 and L19 bind to HCMV essential glycoproteins B and H,
respectively. Thus, RNA ligands that bind to different surface antigens of HCMV
can be simultaneously isolated by the selection procedure. Our study demonstrates
the feasibility of using these RNA ligands as a research tool to identify viral
proteins required for infectivity and as an antiviral agent to block viral
infection.
PMID- 10786846
TI - Evidence for an RNA-based catalytic mechanism in eukaryotic nuclear ribonuclease
P.
AB - Ribonuclease P is the enzyme responsible for removing the 5'-leader segment of
precursor transfer RNAs in all organisms. All eukaryotic nuclear RNase Ps are
ribonucleoproteins in which multiple protein components and a single RNA species
are required for activity in vitro as well as in vivo. It is not known, however,
which subunits participate directly in phosphodiester-bond hydrolysis. The RNA
subunit of nuclear RNase P is evolutionarily related to its catalytically active
bacterial counterpart, prompting speculation that in eukaryotes the RNA may be
the catalytic component. In the bacterial RNase P reaction, Mg(II) is required to
coordinate the nonbridging phosphodiester oxygen(s) of the scissile bond. As a
consequence, bacterial RNase P cannot cleave pre-tRNA in which the pro-Rp
nonbridging oxygen of the scissile bond is replaced by sulfur. In contrast, the
RNase P reaction in plant chloroplasts is catalyzed by a protein enzyme whose
mechanism does not involve Mg(II) coordinated by the pro-Rp oxygen. To determine
whether the mechanism of nuclear RNase P resembles more closely an RNA- or a
protein-catalyzed reaction, we analyzed the ability of Saccharomyces cerevisiae
nuclear RNase P to cleave pre-tRNA containing a sulfur substitution of the pro-Rp
oxygen at the cleavage site. Sulfur substitution at this position prohibits
correct cleavage of pre-tRNA. Cleavage by eukaryotic RNase P thus depends on the
presence of a thio-sensitive ligand to the pro-Rp oxygen of the scissile bond,
and is consistent with a common, RNA-based mechanism for the bacterial and
eukaryal enzymes.
PMID- 10786847
TI - Determination of preferential binding sites for anti-dsRNA antibodies on double
stranded RNA by scanning force microscopy.
AB - The monoclonal anti-dsRNA antibody J2 binds double-stranded RNAs (dsRNA) in an
apparently sequence-nonspecific way. The mAb only recognizes antigens with double
stranded regions of at least 40 bp and its affinity to poly(A) poly(U) and to
dsRNAs with mixed base pair composition is about tenfold higher than to poly(I)
poly(C). Because no specific binding site could be determined, the number, the
exact dimensions, and other distinct features of the binding sites on a given
antigen are difficult to evaluate by biochemical methods. We therefore employed
scanning force microscopy (SFM) as a method to analyze antibody-dsRNA interaction
and protein-RNA binding in general. Several in vitro-synthesized dsRNA
substrates, generated from the Dictyostelium PSV-A gene, were used. In addition
to the expected sequence-nonspecific binding, imaging of the complexes indicated
preferential binding of antibodies to the ends of dsRNA molecules as well as to
certain internal sites. Analysis of 2,000 bound antibodies suggested that the
consensus sequence of a preferential internal binding site is A2N9A3N9A2, thus
presenting A residues on one face of the helix. The site was verified by site
directed mutagenesis, which abolished preferential binding to this region. The
data demonstrate that SFM can be efficiently used to identify and characterize
binding sites for proteins with no or incomplete sequence specificity. This is
especially the case for many proteins involved in RNA metabolism.
PMID- 10786844
TI - Characterization of human RNA splice signals by iterative functional selection of
splice sites.
AB - An iterative in vitro splicing strategy was employed to select for optimal 3'
splicing signals from a pool of pre-mRNAs containing randomized regions.
Selection of functional branchpoint sequences in HeLa cell nuclear extract
yielded a sequence motif that evolved from UAA after one round of splicing toward
a UACUAAC consensus after seven rounds. A significant part of the selected
sequences contained a conserved AAUAAAG motif that proved to be functional both
as a polyadenylation signal and a branch site in a competitive manner.
Characterization of the branchpoint in these clones to either the upstream or
downstream adenosines of the AAUAAAG sequence revealed that the branching process
proceeded efficiently but quite promiscuously. Surprisingly, the conserved
guanosine, adjacent to the common AAUAAA polyadenylation motif, was found to be
required only for polyadenylation. In an independent experiment, sequences
surrounding an optimal branchpoint sequence were selected from two randomized 20
nt regions. The clones selected after six rounds of splicing revealed an extended
polypyrimidine tract with a high frequency of UCCU motifs and a highly conserved
YAG sequence in the extreme 3' end of the randomized insert. Mutating the 3'
terminal guanosine of the intron strongly affects complex A formation, implying
that the invariant AG is recognized early in spliceosome assembly.
PMID- 10786849
TI - Complementarity between the mRNA 5' untranslated region and 18S ribosomal RNA can
inhibit translation.
AB - In eubacteria, base pairing between the 3' end of 16S rRNA and the ribosome
binding site of mRNA is required for efficient initiation of translation. An
interaction between the 18S rRNA and the mRNA was also proposed for translation
initiation in eukaryotes. Here, we used an antisense RNA approach in vivo to
identify the regions of 18S rRNA that might interact with the mRNA 5'
untranslated region (5' UTR). Various fragments covering the entire mouse 18S
rRNA gene were cloned 5' of a cat reporter gene in a eukaryotic vector, and
translation products were analyzed after transient expression in human cells. For
the largest part of 18S rRNA, we show that the insertion of complementary
fragments in the mRNA 5' UTR do not impair translation of the downstream open
reading frame (ORF). When translation inhibition is observed, reduction of the
size of the complementary sequence to less than 200 nt alleviates the inhibitory
effect. A single fragment complementary to the 18S rRNA 3' domain retains its
inhibitory potential when reduced to 100 nt. Deletion analyses show that two
distinct sequences of approximately 25 nt separated by a spacer sequence of 50 nt
are required for the inhibitory effect. Sucrose gradient fractionation of
polysomes reveals that mRNAs containing the inhibitory sequences accumulate in
the fractions with 40S ribosomal subunits, suggesting that translation is blocked
due to stalling of initiation complexes. Our results support an mRNA-rRNA base
pairing to explain the translation inhibition observed and suggest that this
region of 18S rRNA is properly located for interacting with mRNA.
PMID- 10786850
TI - Polyadenylation of three classes of chloroplast RNA in Chlamydomonas reinhadtii.
AB - Three classes of RNA, represented by atpB and petD mRNAs, Arg and Glu tRNAs, and
5S rRNA, were found to exist in polyadenylated form in Chlamydomonas reinhardtii
chloroplasts. Sequence analysis of cDNA clones derived from reverse transcriptase
polymerase chain reaction protocols used to select polyadenylated RNAs revealed
that, at least for the mRNAs and tRNAs, there are three apparent types of
polyadenylation. In the first case, the poly(A) tail is added at or near the
mature 3' end, even when this follows a strong secondary structure. In the second
case, the tail is added to pre-mRNA or pre-tRNA, suggesting a possible
competition between polyadenylation and RNA-processing pathways. Finally, in all
cases, the poly(A) tail can be added internally, possibly as a part of an RNA
decay pathway. The tails found in Chlamydomonas chloroplasts differ from those of
spinach chloroplasts in adenine content, being nearly homopolymeric (>98%
adenine) versus 70% in spinach, and are similar in length to those of Escherichia
coli, being mostly between 20 and 50 nt. In vitro assays using a Chlamydomonas
chloroplast protein extract showed that a 3' end A25 tail was sufficient to
stimulate rapid degradation of atpB RNA in vitro, with a lesser effect for petD,
and only minor effects on trnE. We therefore propose that polyadenylation
contributes to mRNA degradation in Chlamydomonas chloroplasts, but that its
effect may vary.
PMID- 10786851
TI - A test of the model to predict unusually stable RNA hairpin loop stability.
AB - To investigate the accuracy of a model [Giese et al., 1998, Biochemistry37:1094
1100 and Mathews et al., 1999, JMol Biol 288:911-940] that predicts the stability
of RNA hairpin loops, optical melting studies were conducted on sets of hairpins
previously determined to have unusually stable thermodynamic parameters. Included
were the tetraloops GNRA and UNCG (where N is any nucleotide and R is a purine),
hexaloops with UU first mismatches, and the hairpin loop of the iron responsive
element, CAGUGC. The experimental values for the GNRA loops are in excellent
agreement (deltaG degrees 37 within 0.2 kcal/mol and melting temperature (TM)
within 4 degrees C) with the values predicted by the model. When the UNCG hairpin
loops are treated as tetraloops, and a bonus of 0.8 kcal/mol included in the
prediction to account for the extra stable first mismatch (UG), the measured and
predicted values are also in good agreement (deltaG degrees 37 within 0.7
kcal/mol and TM within 3 degrees C). Six hairpins with unusually stable UU first
mismatches also gave good agreement with the predictions (deltaG degrees 37
within 0.5 kcal/mol and TM within 8 degrees C), except for hairpins closed by
wobble base pairs. For these hairpins, exclusion of the additional stabilization
term for UU first mismatches improved the prediction (AG degrees 37 within 0.1
kcal/mol and TM within 3 degrees C). Hairpins with the iron-responsive element
loop were not predicted well by the model, as measured deltaG degrees 37 values
were at least 1 kcal/mol greater than predicted.
PMID- 10786852
TI - Expression of the Naegleria intron endonuclease is dependent on a functional
group I self-cleaving ribozyme.
AB - NaSSU1 is a complex nuclear group I intron found in several species of Naegleria,
consisting of a large self-splicing group I ribozyme (NaGIR2), which itself is
interrupted by a small, group I-like ribozyme (NaGIR1) and an open reading frame
(ORF) coding for a homing endonuclease. The GIR1 ribozyme cleaves in vitro
transcripts of NaSSU1 at two internal processing sites about 400 nt downstream of
the 5' end of the intron, proximal to the endonuclease ORF. Here we demonstrate
that self-cleavage of the excised intron also occurs in vivo in Naegleria
gruberi, generating an ORF-containing RNA that possesses a short leader with a
sequence element likely to be involved in gene expression. To assess the
functional significance of self-cleavage, we constructed a genetic system in
Saccharomyces cerevisiae. First, a mutant yeast strain was selected with a
mutation in all the rRNA genes, rendering the rDNA resistant to cleavage by the
Naegleria endonuclease. Active endonuclease, which is otherwise lethal, could be
expressed readily in these cells. Endonuclease activity also could be detected in
extracts of yeast harboring plasmids in which the endonuclease ORF was embedded
in its native context in the intron. Analysis of the RNA from these yeast cells
showed that the excised intron RNA was processed as in N. gruberi. A mutant
intron constructed to prevent self-cleavage of the RNA failed to express
endonuclease activity. These results support the hypothesis that the NaGIR1
catalyzed self-cleavage of the intron RNA is a key event in expression of the
endonuclease.
PMID- 10786853
TI - Intracellular ribozyme-catalyzed trans-cleavage of RNA monitored by fluorescence
resonance energy transfer.
AB - Small catalytic RNAs like the hairpin ribozyme are proving to be useful
intracellular tools; however, most attempts to demonstrate trans-cleavage of RNA
by ribozymes in cells have been frustrated by rapid cellular degradation of the
cleavage products. Here, we describe a fluorescence resonance energy transfer
(FRET) assay that directly monitors cleavage of target RNA in tissue-culture
cells. An oligoribonucleotide substrate was modified to inhibit cellular
ribonuclease degradation without interfering with ribozyme cleavage, and donor
(fluorescein) and acceptor (tetramethylrhodamine) fluorophores were introduced at
positions flanking the cleavage site. In simple buffers, the intact substrate
produces a strong FRET signal that is lost upon cleavage, resulting in a red-to
green shift in dominant fluorescence emission. Hairpin ribozyme and fluorescent
substrate were microinjected into murine fibroblasts under conditions in which
substrate cleavage can occur only inside the cell. A strong FRET signal was
observed by fluorescence microscopy when substrate was injected, but rapid decay
of the FRET signal occurred when an active, cognate ribozyme was introduced with
the substrate. No acceleration in cleavage rates was observed in control
experiments utilizing a noncleavable substrate, inactive ribozyme, or an active
ribozyme with altered substrate specificity. Subsequently, the fluorescent
substrates were injected into clonal cell lines that expressed cognate or
noncognate ribozymes. A decrease in FRET signal was observed only when substrate
was microinjected into cells expressing its cognate ribozyme. These results
demonstrate trans-cleavage of RNA within mammalian cells, and provide an
experimental basis for quantitative analysis of ribozyme activity and specificity
within the cell.
PMID- 10786856
TI - Tragedy in sport and trial by tabloid.
PMID- 10786857
TI - Snowboarding injuries.
PMID- 10786855
TI - Warm up.
PMID- 10786858
TI - "You don't have to...": walking to a healthier nation.
PMID- 10786859
TI - Role of exercise counselling in health promotion.
PMID- 10786860
TI - Where is the pain coming from in tendinopathy? It may be biochemical, not only
structural, in origin.
PMID- 10786854
TI - REF, an evolutionary conserved family of hnRNP-like proteins, interacts with
TAP/Mex67p and participates in mRNA nuclear export.
AB - Vertebrate TAP and its yeast ortholog Mex67p are involved in the export of
messenger RNAs from the nucleus. TAP has also been implicated in the export of
simian type D viral RNAs bearing the constitutive transport element (CTE).
Although TAP directly interacts with CTE-bearing RNAs, the mode of interaction of
TAP/Mex67p with cellular mRNAs is different from that with the CTE RNA and is
likely to be mediated by protein-protein interactions. Here we show that Mex67p
directly interacts with Yra1p, an essential yeast hnRNP-like protein. This
interaction is evolutionarily conserved as Yra1p also interacts with TAP.
Conditional expression in yeast cells implicates Yra1 p in the export of cellular
mRNAs. Database searches revealed that Yra1p belongs to an evolutionarily
conserved family of hnRNP-like proteins having more than one member in Mus
musculus, Xenopus laevis, Caenorhabditis elegans, and Schizosaccharomyces pombe
and at least one member in several species including plants. The murine members
of the family directly interact with TAP. Because members of this protein family
are characterized by the presence of one RNP-motif RNA-binding domain and exhibit
RNA-binding activity, we called these proteins REF-bps for RNA and export factor
binding proteins. Thus, Yra1p and members of the REF family of hnRNP-like
proteins may facilitate the interaction of TAP/Mex67p with cellular mRNAs.
PMID- 10786865
TI - A pilot study examining injuries in elite gaelic footballers.
AB - OBJECTIVES: To quantify injuries in elite gaelic footballers and to determine the
nature, sites, and outcome of injuries and the possible risk factors involved.
METHODS: Information on injuries was collected from six elite gaelic football
teams by a questionnaire. The footballers were asked to recall injuries over the
preceding six month period. RESULTS: A total of 88 out of 107 subjects sustained
injuries over the study period. Ninety five injuries were recorded, giving an
incidence rate of 1.78 injuries per subject per year, of which 35% were
recurring. It was found that 35% of injuries were sustained during training
sessions. Lower body injuries predominated (77%), the ankle being the most
commonly injured anatomic site. Most injuries were soft tissue in nature: muscle,
33%; ligament, 32%; tendon, 16%. The most common situations giving rise to
injuries were collision (22%) and twist/turn (19%). Foul play only accounted for
about 6% of injuries. Mean time off play as a result of injury was 17.3 days, and
hospital admission was necessary for 15% of the injuries. CONCLUSION: Despite the
limitations of a retrospective of this nature, the study provides useful and
important information on injuries in gaelic footballers.
PMID- 10786864
TI - Incidence, site, and nature of injuries in amateur rugby league over three
consecutive seasons.
AB - OBJECTIVES: To report the incidence, site, and nature of injuries in amateur
rugby league over three consecutive seasons. METHODS: Six hundred players
registered with an amateur rugby league organisation were studied over three
consecutive seasons. All injuries sustained during the amateur rugby league
matches were recorded. Information recorded included the date and time of injury,
name of injured player, anatomical site and nature of injury, and position of the
player. RESULTS: The incidence of injury was 160.6 per 1000 player-position game
hours, with forwards having a significantly higher incidence of injury than backs
(182.3 per 1000 v 142.0 per 1000, chi2 = 14.60, df = 1, p<0.001). Over 25% of the
total injuries (40.6 per 1000) sustained during the three year period were to the
head and neck, while injuries to the face (21.3 per 1000, 13.3%), abdomen and
thorax (21.3 per 1000, 13.3%), and knee (17.8 per 1000, 11.1%) were less common
(chi2 = 21.83, df = 8, p<0.01). Muscular injuries (haematomas and strains) were
the most common type of injury (45.7 per 1000, 28.5%, chi2 = 17.98, df = 7,
p<0.05). Significantly more injuries occurred in the latter stages of the season
(chi2 = 22.94, df = 1, p<0.001), with most injuries (70.8%, chi2 = 162.29, df =
1, p<0.001) sustained in the second half of matches. CONCLUSIONS: The results
show that muscular injuries and injuries to the head and neck are the most
commonly sustained injuries in amateur rugby league. Furthermore, injuries are
more often sustained in the latter stages of the season and during the second
half of matches. These findings suggest that fatigue or accumulative microtrauma,
or both, may contribute to injuries in amateur rugby league players.
PMID- 10786861
TI - VO2 slow component and performance in endurance sports.
PMID- 10786862
TI - Physical activity mediates a healthier body weight in the presence of obesity.
PMID- 10786863
TI - Incidence and nature of the most common rugby injuries sustained in Argentina
(1991-1997).
AB - OBJECTIVE: To study the incidence of the most commonly sustained injuries in
Argentine rugby and analyse them according to type, position and age of the
players, and phase and time of play. METHODS: A prospective registry of injuries
was constructed in different provincial unions of Argentina. Data were collected
during a whole weekend each year from 1991 to 1997. Chi2 with Yates correction
test, contingency tables, odds ratios (OR), and 95% confidence intervals (CI)
were calculated (Epi Info Version 6.04a). RESULTS: A total of 924 injuries were
registered in 1296 rugby games, involving 38 933 players. The mean (SD) incidence
per weekend was 2.4 (0.2)% (95% CI 2.22 to 2.53), and the number of injuries per
season was 24,188. Overall, senior players suffered more injuries than those in
younger divisions (OR = 1.53; 95% CI 1.34 to 1.76; p<0.0001). The most common
type of injury was pulled muscles of the lower limbs (11.7%, p<0.0001). Overall,
the knee was the most susceptible to injury (14.1%, p<0.0001). Senior players
suffered more pulled muscles of the lower limbs (OR = 2.99; 95% CI 2.01 to 4.46;
p<0.0001), ankle ligament distension (OR = 1.69; 95% CI 1.12 to 2.53; p = 0.01),
knee trauma (OR = 1.69; 95% CI 1.06 to 2.68; p = 0.02), bleeding wounds on the
face (OR = 3.86; 95% CI 2.24 to 6.70; p<0.0001), and knee ligament distension (OR
= 2.14; 95% CI 1.16 to 3.96; p = 0.01). Younger players had a greater risk of
suffering muscular or ligament injuries of the cervical column (OR = 3.0; 95% CI
1.05 to 10.08; p = 0.04). The forwards had a higher risk of injury (OR = 1.41;
95% CI 1.23 to 1.61; p<0.0001). The most commonly injured player was the flanker
(15.5%, p<0.01), and the most common mechanism was in open play (33%). More
injuries were sustained in the second half (OR = 1.17; 95% CI 1.03 to 1.34; p =
0.01). CONCLUSIONS: Injuries are the cause of significant morbidity among rugby
players in Argentina. A more thorough investigation and a greater understanding
of the mechanisms are crucial in order to update the rugby laws and reduce this
high injury incidence.
PMID- 10786866
TI - Effects of massage on physiological restoration, perceived recovery, and repeated
sports performance.
AB - BACKGROUND: Despite massage being widely used by athletes, little scientific
evidence exists to confirm the efficacy of massage for promoting both
physiological and psychological recovery after exercise and massage effects on
performance. AIM: To investigate the effect of massage on perceived recovery and
blood lactate removal, and also to examine massage effects on repeated boxing
performance. METHODS: Eight amateur boxers completed two performances on a boxing
ergometer on two occasions in a counterbalanced design. Boxers initially
completed performance 1, after which they received a massage or passive rest
intervention. Each boxer then gave perceived recovery ratings before completing a
second performance, which was a repeated simulation of the first. Heart rates and
blood lactate and glucose levels were also assessed before, during, and after all
performances. RESULTS: A repeated measures analysis of variance showed no
significant group differences for either performance, although a main effect was
found showing a decrement in punching force from performance 1 to performance 2
(p<0.05). A Wilcoxon matched pairs test showed that the massage intervention
significantly increased perceptions of recovery (p<0.01) compared with the
passive rest intervention. A doubly multivariate multiple analysis of variance
showed no differences in blood lactate or glucose following massage or passive
rest interventions, although the blood lactate concentration after the second
performance was significantly higher following massage (p<0.05). CONCLUSIONS:
These findings provide some support for the psychological benefits of massage,
but raise questions about the benefit of massage for physiological restoration
and repeated sports performance.
PMID- 10786867
TI - Does physical activity reduce the risk of developing peptic ulcers?
AB - BACKGROUND: Although Helicobacter pylori has been identified as a major cause of
chronic gastritis, not all infected patients develop ulcers, suggesting that
other factors such as lifestyle may be critical to the development of ulcer
disease. AIM: To investigate the role physical activity may play in the incidence
of peptic ulcer disease. METHODS: The subjects were men (8529) and women (2884)
who attended the Cooper Clinic in Dallas between 1970 and 1990. The presence of
gastric or duodenal ulcer disease diagnosed by a doctor was determined from a
mail survey in 1990. Subjects were classified into three physical activity groups
according to information provided at the baseline clinic visit (before 1990):
active, those who walked or ran 10 miles or more a week; moderately active, those
who walked or ran less than 10 miles a week or did another regular activity; the
referent group consisting of those who reported no regular physical activity.
RESULTS: With the use of gender specific proportional hazards regression models
that could be adjusted for age, smoking, alcohol use, body mass index, and self
reported tension, active men were found to have a significant reduction in risk
for duodenal ulcers (relative hazard (95% confidence interval) for the active
group was 0.38 (0.15 to 0.94) and 0.54 (0.30 to 0.96) for the moderately active
group). No association was found between physical activity and gastric ulcers for
men or for either type of ulcer for women. CONCLUSIONS: Physical activity may
provide a non-pharmacological method of reducing the incidence of duodenal ulcers
among men.
PMID- 10786868
TI - Recurrent haematomas of the thigh: a case of von Willebrand's disease presenting
to a sports clinic.
AB - Von Willebrand's disease is a relatively common mild form of haemophilia. It
should be suspected in assessing sports injuries when excessive bleeding occurs
in response to relatively mild trauma. Those with the disease should remain
active but avoid contact sports. They should not take aspirin or non-steroidal
anti-inflammatory drugs, which may exacerbate bleeding, and should be given
supportive treatment to cover dental extraction, surgery, or significant bleeding
episodes.
PMID- 10786869
TI - The pathological status of exercise dependence.
AB - OBJECTIVES: This study was concerned with the concept of exercise dependence.
Levels of psychological morbidity, personality profiles, and exercise beliefs
were compared among subjects screened for exercise dependence and eating
disorders. METHOD: Adult female exercisers were allocated on the basis of
questionnaire screening to one of the following groups: primary exercise
dependence (n = 43); secondary exercise dependence, where there was the
coincidence of exercise dependence and an eating disorder (n = 27); eating
disorder (n =14); control, where there was no evidence of either exercise
dependence or eating disorder (n = 110). Questionnaire assessment was undertaken
of psychological morbidity, self esteem, weight and body shape dissatisfaction,
personality, and exercise beliefs. RESULTS: Aside from a higher incidence of
reported menstrual abnormalities, the primary exercise dependence group was
largely indistinguishable from the controls. In stark contrast, the secondary
exercise dependence group reported higher levels of psychological morbidity,
neuroticism, dispositional addictiveness, and impulsiveness, lower self esteem,
greater concern with body shape and weight, as well as with the social,
psychological, and aesthetic costs of not exercising than the controls, but
differed little from the eating disorder group. CONCLUSIONS: In the absence of an
eating disorder, women identified as being exercise dependent do not exhibit the
sorts of personality characteristics and levels of psychological distress that
warrant the construction of primary exercise dependence as a widespread
pathology.
PMID- 10786870
TI - Sports injury incidence.
PMID- 10786871
TI - Sudden cardiac death in sport--spectre or preventable risk?
PMID- 10786872
TI - Basic life support.
PMID- 10786873
TI - If jogging is a joke, who should have the last laugh?
PMID- 10786875
TI - Water jet skiing, a dangerous sport with inadequate policing!
PMID- 10786876
TI - Electrocardiographic changes in "elite" athletes.
PMID- 10786877
TI - The genetics of physical fitness.
PMID- 10786880
TI - Membrane proteins and proteomics: un amour impossible?
AB - Proteome analysis implies the ability to separate proteins as a first step prior
to characterization. Thus, the overall performance of the analysis strongly
depends on the performance of the separation tool, usually two-dimensional
electrophoresis. This review shows how two-dimensional electrophoresis performs
with membrane proteins from bacteria or animal or vegetable cells and tissues,
the recent progress in this field, and it examines future prospects in this area.
PMID- 10786879
TI - The current state of two-dimensional electrophoresis with immobilized pH
gradients.
AB - The original protocol of two-dimensional electrophoresis with immobilized pH
gradient (IPG-Dalt; Gorg et al., Electrophoresis 1988, 9, 531-546) is updated.
Merits and limits of different methods for sample solubilization, sample
application (by cup-loading or ingel rehydration) with respect to the pH interval
used for IPG-isoelectric focusing are critically discussed. Guidelines for
running conditions of analytical and micropreparative IPG-Dalt, using wide IPGs
up to pH 12 for overview patterns, or narrow IPGs for zoom-in gels for optimum
resolution and detection of minor components, are stated. Results with extended
separation distances as well as automated procedures are demonstrated, and a
comparison between protein detection by silver staining and fluorescent dyes is
given. A brief trouble shooting guide is also included.
PMID- 10786881
TI - Proteomics: capacity versus utility.
AB - Until recently scientists studied genes or proteins one at a time. With
improvements in technology, new tools have become available to study the complex
interactions that occur in biological systems. Global studies are required to do
this, and these will involve genomic and proteomic approaches. High-throughput
methods are necessary in each case because the number of genes and proteins in
even the simplest of organisms are immense. In the developmental phase of
genomics, the emphasis was on the generation and assembly of large amounts of
nucleic acid sequence data. Proteomics is currently in a phase of technological
development and establishment, and demonstrating the capacity for high throughput
is a major challenge. However, funding bodies (both in the public and private
sector) are increasingly focused on the usefulness of this capacity. Here we
review the current state of proteome research in terms of capacity and utility.
PMID- 10786878
TI - Performance enhancing drugs; damned if you do, and damned if you don't.
PMID- 10786874
TI - Acute injury incidence in professional county club cricket players (1985-1995).
AB - BACKGROUND: There is a dearth of evidenced based research into sports injury in
professional cricket. AIM: To investigate the incidence, nature, and site of
acute injuries sustained by professional cricketers at one English county club
over the period 1985-1995. METHODS: Injuries in a sample of 54 cricketers who had
played in the first team for the same county cricket club in any or all seasons
between 1985 and 1995 were investigated. Injury was defined as the onset of pain
or a disability resulting from either training for or playing cricket, which
caused the player to seek medical attention. RESULTS: An acute injury rate of
57.4 injuries per 1000 days of cricket played was found, with most injuries
sustained during April, the month in which the least number of days were played.
The lower limb was the region most vulnerable to injury, accounting for 44.9% of
all injuries, followed by the upper limb (29.4%), the trunk (20.0%), and the head
and neck (5.7%). No significant difference in injury incidence among player
positions was found. CONCLUSION: There is a need for a system of epidemiological
data collection and development of a national cricket injury database to help
predict, reduce, and prevent injury at all levels of the game.
PMID- 10786884
TI - The dynamic range of protein expression: a challenge for proteomic research.
AB - Proteomic research, for its part, is benefiting enormously from the last decade
of genomic research as we now have archived, annotated and audited sequence
databases to correlate and query experimental data. While the two-dimensional
electrophoresis (2-DE) gels are still a central part of proteomics, we reflect on
the possibilities and realities of the current 2-DE technology with regard to
displaying and analysing proteomes. Limitations of analysing whole cell/tissue
lysates by 2-DE alone are discussed, and we investigate whether extremely narrow
p/ranges (1 pH unit/25 cm) provide a solution to display comprehensive protein
expression profiles. We are confronted with a challenging task: the dynamic range
of protein expression. We believe that most of the existing technology is capable
of displaying many more proteins than is currently achievable by integrating
existing and new techniques to prefractionate samples prior to 2-DE display or
analysis. The availability of a "proteomics toolbox", consisting of defined
reagents, methods, and equipment, would assist a comprehensive analysis of
defined biological systems.
PMID- 10786889
TI - Recent advancements in surface-enhanced laser desorption/ionization-time of
flight-mass spectrometry.
AB - The overall history and recent advances in surface enhanced laser
desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS) technology
is reviewed herein. Fundamentals of SELDI-TOF analysis are presented while
drawing comparisons with other laser-based mass spectrometry techniques. The
application of SELDI-TOF-MS to functional genomics and biomarker discovery is
discussed and exemplified by elucidating a biomarker candidate for prostatic
carcinoma. Finally, a short discussion regarding future SELDI requirements and
developments is supplied.
PMID- 10786882
TI - Better approaches to finding the needle in a haystack: optimizing proteome
analysis through automation.
AB - Recent evidence has demonstrated a lack of correlation between transcriptional
profiles and actual protein levels in cells. Proteome analysis has therefore
become indispensable and complementary to genomic analysis for an accurate
picture of cellular metabolism. Although proteomics is a relatively young
discipline, technology for increasing throughput in proteomic projects is rapidly
being developed. The operating paradigm in proteome analysis today is a
combination of two-dimensional (2-D) gel electrophoresis (for protein resolution)
with mass spectrometry (for protein identification). All the intermediary steps
in the procedure including gel staining, image analysis, protein spot excision,
digestion and mass spectrometry can be automated to increase efficiency and save
time. This report reviews the current state of the proteomics technology and
discusses approaches to enhance the sensitivity of 2-D gels with fractionation
techniques.
PMID- 10786883
TI - Subproteomics based upon protein cellular location and relative solubilities in
conjunction with composite two-dimensional electrophoresis gels.
AB - Progress in the field of proteomics is dependent upon an ability to visualise
close to an entire protein complement via a given array technology. These efforts
have previously centred upon two-dimensional gel electrophoresis in association
with immobilised pH gradients in the first dimension. However, limitations in
this technology, including the inability to separate hydrophobic, basic, and low
copy number proteins have hindered the analysis of complete proteomes. The
challenge is now to overcome these limitations through access to new technology
and improvements in existing methodologies. Proteomics can no longer be equated
with a single two-dimensional electrophoresis gel. Greater information can be
obtained using targeted biological approaches based upon sample prefractionation
into specific cellular compartments to determine protein location, while novel
immobilised pH gradients spanning single pH units can be used to display poorly
abundant proteins due to their increased resolving power and loading capacity. In
this study, we show the effectiveness of a combined use of two differential
subproteomes (as defined by relative solubilities, cellular location and narrow
range immobilised pH gradients) to increase the resolution of proteins contained
on two-dimensional gels. We also present new results confirming that this method
is capable of displaying up to a further 45% of a given microbial proteome.
Subproteomics, utilising up to 40 two-dimensional gels per sample will become a
powerful tool for near-to-total proteome analysis in the postgenome era.
Furthermore, this new approach can direct biological focus towards molecules of
specific interest within complex cells and thus simplify efforts in discovery
based proteome research.
PMID- 10786885
TI - Combination of electrophoretic techniques for comprehensive analysis of complex
protein systems.
AB - Analysis of proteins in complex mixtures such as cell lysates is presently
performed by two-dimensional polyacrylamide gel electrophoresis under denaturing
conditions (denaturing 2-D PAGE) followed by extraction of proteins from gel
pieces and structural analysis of the proteins. This type of protein analysis is
contributing to the correlation of information stored in DNA sequences with the
structure of the product polypeptides. However, denaturing 2-D PAGE has its own
limitations and it is necessary to develop various methods of protein analysis to
reconstruct the total structure and function of proteins in complex systems. This
review article summarizes the work in our laboratory to explore proteins in human
plasma combining various electrophoretic techniques: nondenaturing and denaturing
2-D PAGE, capillary electrophoresis, and agarose gel isoelectric focusing.
PMID- 10786888
TI - Biosensor chip mass spectrometry: a chip-based proteomics approach.
AB - Rapid advances in genomic sequencing, bioinformatics, and analytical
instrumentation have created the field of proteomics, which at present is based
largely on two-dimensional electrophoresis (2-DE) separation of complex protein
mixtures and identification of individual proteins using mass spectrometry. These
analyses provide a wealth of data, which upon further evaluation leads to many
questions regarding the structure and function of the proteins. The challenge of
answering these questions create a need for high-specificity approaches that may
be used in the analysis of biomolecular recognition events and interacting
partners, and thereby places great demands on general protein characterization
instrumentation and the types of analyses they need to perform. Over the past
five years we have been actively involved in interfacing two general,
instrumental techniques, surface plasmon resonance-biomolecular interaction
analysis (SPR-BIA) and matrix-assisted laser desorption/ionization time-of-flight
(MALDI-TOF) mass spectrometry, into a single concerted approach for use in the
functional and structural characterization of proteins. Reviewed here is the
recent progress made using biomolecular interaction analysis - mass spectrometry
(BIA-MS) in the detailed characterization of proteins and protein-protein
interactions and the development of biosensor chip mass spectrometry (BCMS) as a
new chip-based proteomics approach.
PMID- 10786886
TI - A thousand points of light: the application of fluorescence detection
technologies to two-dimensional gel electrophoresis and proteomics.
AB - As proteomics evolves into a high-throughput technology for the study of global
protein regulation, new demands are continually being placed upon protein
visualization and quantitation methods. Chief among these are increased detection
sensitivity, broad linear dynamic range and compatibility with modern methods of
microchemical analyses. The limitations of conventional protein staining
techniques are increasingly being encountered as high sensitivity electrophoresis
methods are interfaced with automated gel stainers, image analysis workstations,
robotic spot excision instruments, protein digestion work stations, and mass
spectrometers. Three approaches to fluorescence detection of proteins in two
dimensional (2-D) gels are currently practiced: covalent derivatization of
proteins with fluorophores, intercalation of fluorophores into the sodium dodecyl
sulfate (SDS) micelle, and direct electrostatic interaction with proteins by a
Coomassie Brilliant Blue-type mechanism. This review discusses problems
encountered in the analysis of proteins visualized with conventional stains and
addresses advances in fluorescence protein detection, including immunoblotting,
as well as the use of charge-coupled device (CCD) camera-based and laser-scanner
based image acquisition devices in proteomics.
PMID- 10786887
TI - Protein identification methods in proteomics.
AB - A combination of high-resolution two-dimensional (2-D) polyacrylamide gel
electrophoresis, highly sensitive biological mass spectrometry, and the rapidly
growing protein and DNA databases has paved the way for high-throughput
proteomics. This review concentrates on protein identification. We first discuss
the use of protein electroblotting and Edman sequencing as tools for de novo
sequencing and protein identification. In the second part, we highlight matrix
assisted laser desorption/ionization mass spectrometry (MALDI-MS) as one of the
main contemporary analytical methods for linking gel-separated proteins to
entries in sequence databases. In this context we describe the two main MALDI-MS
based identification methods: (i) peptide mass fingerprinting, and (ii) post
source decay (PSD) analysis. In the last part, we briefly emphasize the
importance of sample preparation for obtaining highly sensitive and high-quality
MALDI-MS spectra.
PMID- 10786893
TI - Cancer proteomics: from identification of novel markers to creation of artifical
learning models for tumor classification.
AB - Studies of global protein expression in human tumors have led to the
identification of various polypeptide markers, potentially useful as diagnostic
tools. Many changes in gene expression recorded between benign and malignant
human tumors are due to post-translational modifications, not detected by
analyses of RNA. Proteome analyses have also yielded information about tumor
heterogeneity and the degree of relatedness between primary tumors and their
metastases. Results from our own studies have shown a similar pattern of changes
in protein expression in different epithelial tumors, such as decreases in
tropomyosin and cytokeratin expression and increases in proliferating cell
nuclear antigen (PCNA) and heat shock protein expression. Such information has
been used to create artificial learning models for tumor classification. The
artificial learning approach has potential to improve tumor diagnosis and cancer
treatment prediction.
PMID- 10786890
TI - The analysis of microbial proteomes: strategies and data exploitation.
AB - Microbes present special opportunities for proteomic analysis that are not yet
available for other types of organisms, due mainly to the relative abundance of
information on their genomes, their low levels of functional redundancy and their
experimental tractability. They are also being used to develop and validate
powerful new experimental approaches that surmount some important current
limitations in this field. The review surveys the different proteomic procedures
that are available and considers the advantages and disadvantages of different
experimental strategies. The ways in which microbiologists - and others - can
exploit proteomic data are also discussed.
PMID- 10786892
TI - Biomedical applications of two-dimensional electrophoresis using immobilized pH
gradients: current status.
AB - There is currently much interest, as we enter the postgenome era, in studying
gene expression at the protein level. Two-dimensional electrophoresis (2-DE)
using immobilized pH gradients (IPG), coupled with mass spectrometry (MS), is
currently the most widely utilized approach for the analysis of whole tissue
proteins. The methodology for IPG-based 2-DE, since the introduction of the
technique in the 1980s, is reviewed. In its present form the IPG methodology is
mostly useful as a research tool. In general, high reproducibility and high
resolution have been achieved. However, the lack of substantial automation and
the limited sensitivity of the current overall methodology continue to represent
drawbacks for biomedical applications. Further developments to increase
throughput and to reduce sample requirement would substantially benefit the
application of IPG-based 2-DE to biomedicine and would enhance the prospects for
introducing the methodology into the clinical laboratory.
PMID- 10786894
TI - Heat shock proteins in human cancer.
AB - The heat shock proteins (hsp) are ubiquitous molecules induced in cells exposed
to sublethal heat shock, present in all living cells, and highly conserved during
evolution. Their function is to protect cells from environmental stress damage by
binding to partially denatured proteins, dissociating protein aggregates, to
regulate the correct folding, and to cooperate in transporting newly synthesized
polypeptides to the target organelles. The molecular chaperones are involved in
numerous diseases, including cancer, revealing changes of expression. In this
review, we mainly describe the relationship of hsp expression with human cancer,
and discuss what is known about their post-translational modifications according
to malignancies.
PMID- 10786891
TI - Proteomics in medical microbiology.
AB - The techniques of proteomics (high resolution two-dimensional electrophoresis and
protein characterisation) are widely used for microbiological research to analyse
global protein synthesis as an indicator of gene expression. The rapid progress
in microbial proteomics has been achieved through the wide availability of whole
genome sequences for a number of bacterial groups. Beyond providing a basic
understanding of microbial gene expression, proteomics has also played a role in
medical areas of microbiology. Progress has been made in the use of the
techniques for investigating the epidemiology and taxonomy of human microbial
pathogens, the identification of novel pathogenic mechanisms and the analysis of
drug resistance. In each of these areas, proteomics has provided new insights
that complement genomic-based investigations. This review describes the current
progress in these research fields and highlights some of the technical challenges
existing for the application of proteomics in medical microbiology. The latter
concern the analysis of genetically heterogeneous bacterial populations and the
integration of the proteomic and genomic data for these bacteria. The
characterisation of the proteomes of bacterial pathogens growing in their natural
hosts remains a future challenge.
PMID- 10786895
TI - Proteomics in molecular medicine: applications in central nervous systems
disorders.
AB - Bodily fluids such as cerebrospinal fluid (CSF) and serum can be analysed at the
time of presentation and throughout the course of the disease. Changes in the
protein composition of CSF may be indicative of altered CNS protein expression
pattern with a causative or diagnostic disease link. These findings can be
strengthened through subsequent proteomic analysis of specific brain areas
implicated in the pathology. New isolation strategies of clinically relevant
cellular material such as laser capture microdissection, protein enrichment
procedures and proteomic approaches to neuropeptide and neurotransmitter analysis
give us the opportunity to map out complex cellular interaction at an
unprecedented level of detail. In neurological disorders multiple underlying
pathogenic mechanisms as well as an acute and a chronic CNS disease components
may require a selective repertoire of molecular targets and biomarkers rather
than an individual protein to better define a complex disease. The resulting
proteome database bypasses many ambiguities of experimental models and may
facilitate pre- and clinical development of more specific disease markers and new
selective fast acting therapeutics.
PMID- 10786901
TI - An investigation of the reactions of H3O+ and O2+ with NO, NO2, N2O and HNO2 in
support of selected ion flow tube mass spectrometry
AB - A selected ion flow tube (SIFT) experimental investigation has been carried out
of the reactions of H3O+, NO+ and O2+ with NO, NO2, N2O and HNO2, in order to
obtain the essential kinetic data for the analyses of these compounds in air
using selected ion flow tube mass spectrometry (SIFT-MS). These investigations
show that NO+ ions do not react at a significant rate with any of these NOx
compounds and that H3O+ ions react only with HNO2 (product ions H2NO2+ (75%) and
NO+ (25%)). O2+ ions react with NO (product ion NO+), NO2 (product ion NO2+) and
HNO2 (product ions NO+ (75%), NO2+ (25%)), but not with N2O. We conclude that
both NO and NO2 can be accurately quantified in air using only O2+ precursor ions
and SIFT-MS when HNO2 is not present. However, when HNO2 is present it invariably
co-exists with both NO and NO2 and then both H3O+ and O2+ precursor ions are
needed to determine the partial pressures of NO, NO2 and HNO2 in the air mixture.
We also conclude that currently N2O cannot be analysed in air using SIFT-MS.
PMID- 10786896
TI - Analysis of methylphenidate and its metabolite ritalinic acid in monkey plasma by
liquid chromatography/electrospray ionization mass spectrometry.
AB - Methylphenidate (MP, Ritalin) is a psychotropic drug widely prescribed to
children for treating the symptoms of attention deficit disorder with and without
hyperactivity. Because little information exists about the effects of chronic MP
administration on cognitive function in children, measures of behavior changes in
non-human primates are important surrogates. An essential component of such
studies is the determination of MP plasma levels under chronic and acute dosing
conditions. An analytical method was developed that provided sufficient
sensitivity to measure low levels of the active parent drug (lower limit of
quantitation = 0.25 ng/mL) and the inactive metabolite, ritalinic acid (RA), in
monkey plasma as well as the ability to conveniently analyze large numbers of
samples. The method uses a polymeric reversed-phase sorbent for solid phase
extraction, an efficient reverse-phase high performance liquid chromatography
(HPLC) separation, deuterated internal standards for isotope dilution
quantification of MP and RA, and detection by sensitive electrospray ionization
mass spectrometry (ES-MS) with a single quadrupole instrument. The method
responses are linear over the range of plasma concentrations of MP and RA
observed in monkeys, gives respective analyte recoveries of 75 and 60% with
reasonable precision and accuracy, and demonstrates robust MS performance for
rapid determination of MP/RA plasma levels. The average peak MP concentration
(ca. 16 ng/mL) and half-lives for MP and RA elimination in monkeys (1.79 and 2.31
h, respectively) were not significantly different under acute vs. chronic dosing
conditions and were comparable to values previously reported from human studies.
PMID- 10786899
TI - Electron impact mass spectral fragmentation of 2a,4-disubstituted 2-chloro/2,2
dichloro-2,2a,3,4-tetrahydro-1H-azeto[2,1-d][1,5]benzothia zepin-1-ones.
AB - The mass spectrometric behaviour of nine 2a,4-disubstituted 2-chloro/2,2-dichloro
2,2a,3,4-tetrahydro-1H-azeto[2,1-d][1,5]b enzothiazepin-1-ones has been studied
with the aid of mass-analysed ion kinetic energy spectrometry and accurate mass
measurements under electron impact ionization. All compounds show a tendency to
eliminate a neutral chlorine atom, or a chloroketene, or neutral propene, or
styrene or substituted styrene molecule, plus Cl and/or H (or Cl) atom(s), to
yield [M-Cl]+ ions, 2,3-dihydro-1,5-benzothiazepine derivative ions, 4,5-dihydro
5H-1,5-benzothiazepin-4-one ions which can further lose CO to give 1,4
benzothiazine ions. Both molecular ions and [M-Cl]+ ions show a tendency to
eliminate an ethyl or benzyl/substituted benzyl radical to produce 2,2a-dihydro
1H-azeto[2,1-c][1,4]benzothiazin-1-one ions. The [M-Cl]+ ions could undergo
rearrangement to yield 2,2a-dihydro-1H-azeto[2,1-d][1,5]benzothiazepin-1-one
ions, 2,2a,3,4-tetrahydro-1H-azeto[1,2-a]quinoline ions or 1,1a,2,3-tetrahydro
azirino[2,1-d][1,5]benzothiazepine ions by loss of an ethane or a
benzene/substituted benzene, a SH radical or a CO molecule. The molecular ions
could also undergo rearrangement reactions to form other small fragment ions.
PMID- 10786898
TI - Electron impact mass spectral fragmentation patterns of 2a,4-disubstituted 5
benzoyl-2-chloro-2a,3,4,5-tetrahydroazeto[1,2-a][1,5]benzodiazepin-1( 2H)-ones.
AB - The mass spectrometric behaviour of six 2a,4-disubstituted 5-benzoyl-2-chloro
2a,3,4,5-tetrahydroazeto[1,2-a][1,5]benzodia zepin-1(2H)-ones has been studied
with the aid of mass-analysed ion kinetic energy spectrometry and accurate mass
measurements under electron impact ionization. All compounds show a tendency to
eliminate a chlorine atom, a chlorine atom plus benzaldehyde, benzoyl radical,
chloroketene or chlorine atom plus CO and H2O molecules to yield, respectively,
[M-Cl]+ ions, 2a,4-disubstituted 2a,3-dihydroazeto[1,2-a][1,5]benzodiazepin-1(2H)
one ions, [M-PhCO]+ ions, 2,4-disubstituted 1-benzoyl-2,3-dihydro-1H-1,5
benzodiazepine ions, or 1,2,4-trisubstituted 1H-1,7-benzodiazonine ions, which
could also be formed from [M-Cl]+ ions by loss of CO and H2O molecules
simultaneously. The [M-Cl]+ ions could further lose benzoyl radical to form [M-Cl
PhCO]+ ions, or lose benzoyl amide and undergo a rearrangement to form 4,6
disubstituted 1-benzoazocine-2(1H)-one ions. The [M-PhCO]+ ions could eliminate
NH to produce 2a,4-disubstituted 2,2a,3,4-tetrahydroazeto[1,2,-a]quinolin-1-one
ions, which could further eliminate chloroketene, CO and/or HCl to produce some
important ions, respectively. 2,4-Disubstituted 1-benzoyl-2,3-dihydro-1H-1,5
benzodiazepine ions could lose benzoyl radical to yield 2,4-disubstituted 2,3
dihydro-1H-1,5-benzodiazepine ions, which could further yield other small
fragment ions by loss of propene/styrene or small fragments.
PMID- 10786900
TI - Liquid chromatography electrospray mass spectrometry with variable fragmentor
voltages gives simultaneous elemental and molecular detection of arsenic
compounds.
AB - A single quadrupole high performance liquid chromatography electrospray mass
spectrometry system with a variable fragmentor voltage facility was used in the
positive ion mode for simultaneous recording of elemental and molecular mass
spectral data for arsenic compounds. The method was applicable to the seven
organoarsenic compounds tested: four arsenic-containing carbohydrates
(arsenosugars), a quaternary arsonium compound (arsenobetaine), dimethylarsinic
acid, and dimethylarsinoylacetic acid. It was not suitable for the two inorganic
arsenic species arsenite and arsenate. In the case of arsenosugars, qualifying
ion data for a characteristic common fragment (m/z 237) was also simultaneously
obtained. The method was used to identify and quantify the major arsenosugars in
crude extracts of two brown algae.
PMID- 10786897
TI - Comparison of cyclodextrin-barbiturate noncovalent complexes using electrospray
ionization mass spectrometry and capillary electrophoresis.
AB - Various noncovalent complexes between native and derivatized cyclodextrins (CDs)
and barbiturates were studied using capillary electrophoresis (CE) and
electrospray ionization mass spectrometry (ESI-MS). This paper involves the study
of four aspects of CD-barbiturate noncovalent inclusion complexes. The first
study focused on determining the formation of CD-barbiturate inclusion complexes
in ESI-MS. This determination was accomplished by the comparison of migration
data from CE with ESI-MS inclusion complex peak abundances, which were found to
be complementary. The second study found the possibility of predicting native
beta-CD mediated CE elution orders for barbiturates using data from ESI-MS. A
third study focused on the formation of barbiturate inclusion complexes with
derivatized beta-CD and gamma-CD. As part of this study, the effect of the extent
of side chain substitution on native CD complexation behavior was investigated.
The results indicated that the number of side chains on the CD does not affect
the formation of barbiturate complexes with the hydrophobic CD cavity. Finally, a
comparison of the hydroxypropyl-beta-CD-barbiturate and hydroxypropyl-gamma-CD
barbiturate complexes in CE and ESI-MS was made to study the relationship between
strength of drug-CD binding and enantioresolution. The results from the above
studies indicated that the gas phase and the solution state complexes showed
comparable behavior indicating that similar interactions played a role in
stabilizing these complexes. While it was possible to use the ESI-MS data to
determine drug binding to the CDs, it was not possible to predict whether a
separation of the enantiomers of a chiral barbiturate would occur. However, the
ESI-MS data could be used to eliminate certain CDs from consideration as chiral
selectors.
PMID- 10786902
TI - Characterization of exogenous testosterone in livestock by gas
chromatography/combustion/isotope ratio mass spectrometry: influence of feeding
and age.
AB - The detection of exogenous testosterone in bovine urine was investigated by using
gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). The
carbon isotopic ratio measurement of epitestosterone, etiocholanolone
(testosterone metabolite) and DHEA (testosterone precursor) in female bovine
urines after testosterone enanthate administration was carried out. An important
modification in the 13C/12C ratio of testosterone metabolites was observed, such
that significant differences between precursor and metabolites of testosterone
occurred until three weeks after intramuscular administration of testosterone
enanthate. The factors influencing the 13C/12C of endogenous steroids were
studied especially through cattle feeding and age. The DHEA mean delta13C value
was found to vary between -25 and -26/1000 when hay and concentrate diet were
used for fattening. On the other hand the delta13C value observed when maize
silage was used increased to -20/1000. Testosterone metabolites showed the same
delta13C increase as their precursor. Moreover, we observed a clear relationship
between age and efficiency of misuse determination. Indeed, because of the lower
concentration of natural hormones in young animals, the contribution of exogenous
molecules increases significantly compared with older subjects. Consequently,
demonstration of administration is easier to achieve in calves than in mature
animals.
PMID- 10786904
TI - Electrospray ionization in the study of the polycondensation of Ti(O-i-C3H7)4 and
Ti(O-n-C4H9)4
AB - The polycondensation of Ti(O-i-C3H7)4 (1) and Ti(O-n-C4H9)4 (2), precursors
widely employed in sol-gel processes, has been investigated by electrospray
ionization mass spectrometry. By analysis of 10(-6) M methanol solutions of
compounds 1 and 2, the same ionic species are detected, proving that the first
step in the polycondensation reaction is the i-propyl (or n-butyl) alcohol
methanol complete exchange. This reaction leads to the Ti(OCH3)4 (3) species,
representing the synthon of the polycondensation. Various oligomers of 3 have
been detected and characterized by MS/MS experiments, and the related mechanisms
have been discussed. A minor oligomeric series due to hydroxyl-containing
polycondensation products has also been characterized.
PMID- 10786905
TI - Effects of ion mode and matrix additives in the identification of bacteria by
intact cell mass spectrometry.
AB - Protocols for the identification of bacterial cells by intact cell matrix
assisted laser desorption/ionisation time-of-flight mass spectrometry (ICM-TOFMS)
are presented. A mass range of 500 to 10,000 m/z is used. The use of formic acid
and the crown ether 1, 4, 7, 10, 13, 16-hexaoxacyclooctadecane (18-crown-6) is
described. Crown ether is useful for removing metal ion adducts, which degrade
spectral purity, and formic acid promotes positive ions, improves spectral
signal, and, hence, increases identification certainty.
PMID- 10786907
TI - Mass spectrometrically detected directly coupled high performance liquid
chromatography/nuclear magnetic resonance spectroscopy/mass spectrometry for the
identification of xenobiotic metabolites in maize plants.
AB - Reconstructed ion chromatograms have been used to identify relevant high
performance liquid chromatography (HPLC) peaks in a directly coupled high
performance liquid chromatography/nuclear magnetic resonance spectroscopy/mass
spectrometry (HPLC/NMR/MS) experiment. This has been applied to a study of the
metabolism of a model compound, 5-nitropyridone (2-hydroxy-5-nitropyridine), in
maize plants grown hydroponically. By monitoring the on-flow reconstructed ion
chromatogram corresponding to the 5-nitropyridone fragment at m/z 143, and
additional molecular ions corresponding to metabolites identified as products
from similar compounds, relevant peaks were identified rapidly for subsequent
stopped-flow 1H NMR spectroscopic analysis. The combination of coupled
HPLC/NMR/MS enabled the direct identification of three metabolites, namely the N
glucoside, N-malonylglucoside, and O-malonylglucoside. This work demonstrates the
power of HPLC/NMR/MS for the structural elucidation of xenobiotic metabolites in
complex biological matrices (such as plant material) with minimal sample
preparation. In particular, using mass spectrometry for the initial
identification of relevant HPLC peaks allows the analysis of complex samples
without the necessity for other spectroscopic markers, such as 19F NMR signal for
fluorinated compounds or UV spectroscopy for molecules with strong UV
chromophores.
PMID- 10786903
TI - Tandem mass spectrometry and accurate mass analysis of some N-arylphthalimides.
IV
AB - The mass spectral studies of six N-arylphthalimides are reported. The low
resolution spectra in conjunction with tandem mass spectrometry (MS/MS) and
accurate mass measurements have provided valuable information, and established
the fragmentation modes of the title compounds more precisely.
PMID- 10786909
TI - Differentiation of enantiomers using matrix-assisted laser desorption/ionization
mass spectrometry.
AB - Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has
successfully been used to differentiate pseudo-enantiomeric (isotopically
labelled) amino acids by using cyclodextrin as complexing host. By using
different pseudo-enantiomeric mixtures (i.e. R(Dn) + S; and R + S(Dn)), it has
been demonstrated that the preference of cyclodextrin for S-enantiomers is not
due to the size differences caused by the hydrogen/deuterium substitution. It is
postulated that this method can be extended to differentiate enantiomers (and
determine enantiomeric excess) by using a pair of enantiomeric hosts, as
demonstrated previously using other ionization techniques, but with much higher
sensitivity.
PMID- 10786906
TI - On-line sample preparation using restricted-access media in the analysis of the
soy isoflavones, genistein and daidzein, in rat serum using liquid chromatography
electrospray mass spectrometry.
AB - Soy isoflavones are the subject of many investigations in experimental animals
and humans regarding possible modulation of endocrine activity and
chemoprevention of carcinogenesis. Genistein and daidzein, the principal
biologically active isoflavones in soy, were measured using on-line solid-phase
extraction (SPE) and liquid chromatography electrospray mass spectrometry (LC/ES
MS) detection in serum of rats consuming a common open-formula (NIH 31) chow that
contained approximately 30 microg each of genistein and daidzein per gram of feed
and a specially designed 'soy-free' chow that contained approximately 60-fold
lower isoflavones. The use of a restricted-access/reverse phase trap cartridge
and automated column switching permitted rapid and robust analytical performance
with many injections of plasma onto a reverse phase LC column. Enzymatic
deconjugation and a single centrifugation step were the only sample preparation
steps required. The limit of detection for the isoflavones, based on the MS
responses observed in serum from male and female rats consuming the soy-free
chow, was 0.020 microM. The method, which uses deuterated isoflavones as internal
standards, was determined to be accurate using spiked control serum (102-110% of
added amounts) and precise using spiked control serum and incurred serum (<6%
relative standard deviation). The average genistein and daidzein levels were
determined in female (0.62 and 0.25 microM, respectively) and male rats (0.35 and
0.20 microM, respectively) consuming the standard diet. The sex difference
observed for serum genistein concentrations was statistically significant (p <
0.0001). These results underscore the potential impact of standard open-formula
diets on the results from rodent bioassays of biological activity.
PMID- 10786912
TI - Comment on 'New mass spectrometric approaches to structural analysis in
mixtures', Rapid Commun. Mass Spectrom. 1999; 13: 1797
PMID- 10786910
TI - Error-systematics of determining elemental isotopic abundance ratios by the
molecular ion beam method: a case study for the simultaneous isotopic analysis of
lithium and boron as Li2BO2+
AB - The simultaneous isotopic analysis of lithium and boron by the Li2BO2+ ion beam
method involves measurements of two different molecular abundance ratios (say,
Rj+/-delta(j) and Rk+/-delta(k)), and subsequently extensive calculations to
arrive at the analyte isotopic ratios (say, L and Y). It is not presently known
how the measurement errors (delta(j) and delta(k)) are transformed into the
errors of analysis (deltaL and deltaY). This work addresses this question from
fundamental considerations. In the literature, the calculations are sometimes
simplified using Ri formulae based on Li2B16O2+ ions and then applying correction
factors for the actual Li2BO2+ ions, but this procedure is not generally
applicable. We show how equations based on true Li2BO2+ ions (with full isotopic
variations of all the constituent elements) can be solved, and illustrate the
procedure with several examples. These studies show that accuracy of analysis
depends not only on the accuracies of measurements, delta(j) and delta(k), but
also on the particular isotopic Li2BO2+ ion-pairs (j and k) used as the monitor
pairs. Moreover, this dependence is shown to be different for the different
isotopic ratios (L and Y) to be determined simultaneously. Therefore, proper
selection of monitor molecular pairs is a requirement for avoiding larger
(propagated) errors in the analysis. Similar arguments would, in fact, apply to
any arbitrarily chosen case of determining two or an even greater number of
isotopic abundance ratios (Ei's) by the molecular ion beam method, irrespective
of whether the different analyte ratios, Ei's, relate to a single multi-isotopic
element, or different elements.
PMID- 10786911
TI - Error-systematics of determining simultaneously the isotopic abundance ratios of
natural lithium and natural boron as Li2BO2+
AB - Recently, we have shown how the errors delta(j) and delta(k), that occur when
measuring the two different isotopic molecular abundance ratios required for
analysis, are transformed into the actual errors of elemental isotopic analysis,
(deltaEi/Ei)'s. With a view to gain further understanding as to how the errors
(deltaEi/Ei)'s are governed, we now evaluate theoretically the effects of
selecting different isotopic molecular pairs as the monitor pairs (j and k) for
measurements, and of the measurement errors (delta(j) and delta(k)), on the
results of analysis (the 6Li/7Li and the 10B/11B abundance ratios), by
considering all the constituent elements of Li2BO2+ at their natural isotopic
abundances. It is shown that the ratio of measurement errors, delta(j)/delta(k),
is a more fundamental parameter than either the individual errors (delta(j) and
delta(k)), or their sum, absolute value(delta(j)) + absolute value(delta(k)), in
governing deltaEi/Ei. The important implication of this observation is that it
reveals the possibility of achieving not only a desired level of accuracy in
analysis, but even absolute accuracy (i.e. deltaEi/Ei = 0) by causing mutual
cancellation of the effects of individual measurement errors delta(j) and
delta(k), through proper regulation of measurement parameters. However, as the
measurement errors cannot be pre-set, it is shown how selection of proper monitor
pairs (j and k) can help achieve the desired accuracy in analysis. The present
work sets guidelines for the more general problem of selecting monitor pairs to
avoid larger errors in analysis.
PMID- 10786915
TI - Sepsis due to Clostridium septicum: case report.
PMID- 10786914
TI - Should technologists perform barium enemas?
PMID- 10786913
TI - Electroelution and passive elution of gamma-globulins from sodium dodecyl
sulphate polyacrylamide gel electrophoresis gels for matrix-assisted laser
desorption/ionisation time-of-flight mass spectrometry.
PMID- 10786908
TI - Determination of methotrexate in environmental samples by solid phase extraction
and high performance liquid chromatography: ultraviolet or tandem mass
spectrometry detection?
AB - In order to assess exposure levels of hospital personnel involved in the
preparation and administration of antineoplastic drugs, environmental monitoring
should be carried out. Wipe samples, pads, gloves and air samples should be
collected at the end of each work shift, properly treated and then analysed using
instrumental techniques which are sufficiently sensitive and specific to detect
even trace amounts of drug. In this study, a method using high performance liquid
chromatography/tandem mass spectrometry (HPLC/MS/MS), incorporating solid phase
extraction (SPE), was validated for determination of methotrexate (MTX) in wipe
and air samples. Each step of the method was first developed and optimised using
ultraviolet detection (UV), and afterwards tandem mass spectrometry was used to
obtain a lower limit of quantitation when the expected drug level was less than
the analytical UV detection limit. SPE enabled a 20-fold preconcentration of the
analyte when using HPLC/UV and a further 30-fold preconcentration was obtained
when analysing samples by HPLC/MS/MS. For example, the limit of quantitation
(LLQ) was lowered from 3000 ng on wipe (direct injection onto an HPLC/UV system)
to 5 ng on wipe (SPE plus HPLC/MS/MS). 7-hydroxymethotrexate was used as internal
standard to assess precision and accuracy.
PMID- 10786919
TI - Ultrasound-guided renal biopsy: experience using an automated core biopsy system.
AB - OBJECTIVE: To assess the safety and efficacy of ultrasound-guided percutaneous
renal biopsy using an automated core biopsy system, and to determine
radiologists' accuracy in predicting sample adequacy. METHODS: Ninety-five
biopsies were performed on 25 native kidneys and 70 renal allografts using a 16
gauge automated, spring-loaded core biopsy device under real-time sonographic
guidance. Radiologists performing the biopsy estimated the number of core samples
needed to obtain an adequate specimen, based on visual inspection of each core.
The final determination of the number of samples was made by a pathology
technologist who attended each biopsy, based on preliminary microscopic
examination of tissue cores. After each biopsy, an ultrasonographic examination
was performed to search for biopsy-related hemorrhage, and a questionnaire was
given to the patient to determine biopsy-related complications, which were
categorized as either minor or major. RESULTS: The main indication for biopsy was
acute renal failure (in 43.2% of biopsies). An average of 3 tissue cores per
biopsy were obtained. Of the 94 patients in whom a biopsy was conducted to
exclude diffuse renal disease, a mean of 12.5 glomeruli were present in each
specimen. Overall, adequate tissue for diagnosis was obtained in 98.9% of cases.
The radiologists' estimate of the number of core samples needed concurred with
the pathology technologists' determination of sample adequacy in 88.4% of cases.
A total of 26 complications occurred (in 27.4% of biopsies), consisting of 23
minor (24.2%) and 3 major (3.2%) complications. CONCLUSIONS: Real-time
sonographic guidance in conjunction with an automated core biopsy system is a
safe and accurate method of performing percutaneous renal biopsy. Routine use of
sonographic examinations to search for biopsy-related complications is not
indicated. Radiologists are accurate in estimating sample adequacy in most cases;
however, the presence of a pathology technologist at the biopsy procedure
virtually eliminates the possibility of obtaining insufficient tissue for
histologic diagnosis.
PMID- 10786917
TI - Computed tomographic abnormalities in Mycobacterium avium complex lung disease
include the mosaic pattern of reduced lung attenuation.
AB - OBJECTIVE: To describe the range and frequency of abnormalities on computed
tomographic (CT) scans in patients who met the American Thoracic Society (ATS)
case definition of Mycobacterium avium complex (MAC) lung disease. Further, to
report the effect of time and treatment on the progression of these
abnormalities. METHODS: The demographic, clinical and radiologic features of 10
patients with proven MAC lung disease (mean age 71 years, standard deviation 12
years) were described. The presence or absence of 14 CT abnormalities was
recorded in each of 10 lung zones. The effects of time and treatment on the
abnormalities were recorded. RESULTS: The patients' lung function was minimally
impaired. Pretreatment CT scans showed small nodules in 47% of the lung zones,
reduced lung attenuation in 41%, and bronchiectasis in 27%. Bronchiectasis was
associated with nodules in 20 zones from 9 patients and with no nodules in 7
zones from 1 patient. Reduced attenuation was associated with bronchiectasis
alone in 8 zones, with nodules alone in 25 zones and with both bronchiectasis and
nodules in 8 zones. In patients without treatment, or with non-curative
treatment, bronchiectasis developed or worsened in 12 of 26 zones and resolved or
improved in none. In contrast, after curative treatment, small nodules
disappeared completely in 10 of 21 zones and developed in none. Of 7 zones with
only nodules and reduced attenuation before treatment, 6 had no abnormalities
after treatment. CONCLUSIONS: Our data suggest that the 3 leading CT
abnormalities in nodular-bronchiectatic MAC lung disease are small nodules,
reduced attenuation and bronchiectasis. Reduced attenuation appeared to result
from gas trapping and hypoxic vasoconstriction due to bronchiolocentric
inflammatory nodules. Bronchiectasis appeared to be secondary to this bronchiolar
disease.
PMID- 10786924
TI - Case of the month #77. A 14-year-old boy presented with long-standing anemia and
a recent history of vomiting and abdominal pain.
PMID- 10786916
TI - Button sequestrum in a case of localized Langerhans' cell histiocytosis of the
ilium: case report.
PMID- 10786922
TI - Answer to case of the month #75. Renal angiomyolipoma with intratumoral
hemorrhage and local nodal extension.
PMID- 10786918
TI - Bronchiolitis obliterans after lung transplantation: appearance on expiratory
minimum intensity projection images.
AB - OBJECTIVE: Bronchiolitis obliterans can manifest as a mosaic pattern of lung
attenuation on computed tomographic (CT) scans. This study was conducted to
investigate image enhancement using expiratory minimum intensity projection
images and to compare these with thin-section scans. METHODS: Eleven patients (21
transplanted lungs) with biopsy-proven bronchiolitis obliterans were studied. Ten
1-mm thin-section scans were acquired helically at the level of the carina after
full expiration. Expiratory minimum intensity projection images 10 mm thick were
generated from a multiplanar reconstruction of data. Two thoracic radiologists
analyzed the images. RESULTS: In comparison with thin-section scans, expiratory
minimum intensity projection images demonstrated a greater (in 17 lungs) or equal
(in 4 lungs) percentage area of air trapping, with greater conspicuity (in all 21
lungs). Air trapping involved an average of 52% of the cross-sectional area of 1
lung. CONCLUSIONS: Air trapping due to bronchiolitis obliterans is accentuated by
forced expiration; minimum intensity projection images improve the detection of
differences in lung attenuation. Therefore, expiratory minimum intensity
projection images are very useful in demonstrating the mosaic pattern of lung
attenuation caused by bronchiolitis obliterans.
PMID- 10786920
TI - Extraprostatic biopsy improves the staging of localized prostate cancer.
AB - OBJECTIVE: To evaluate the role and safety of biopsy of the seminal vesicles and
neurovascular bundles in determining the pathologic stage of prostatic carcinoma.
METHODS: Eighty-one consecutive patients were enrolled in a comprehensive
cryosurgical biopsy protocol that included sextant intraprostatic plus
extraprostatic biopsy. The pathologic stage, determined after biopsy, was
compared with the clinical stage, determined by digital rectal examination (DRE)
and transrectal ultrasonographic (TRUS) evaluation. As well, complication rates
for these patients were compared with rates for a separate group that underwent
sextant intraprostatic biopsy alone. RESULTS: Of the 81 patients, 61 (75%) were
confirmed to have cancer by biopsy. None of these patients was considered to have
extraprostatic extension by clinical evaluation (DRE and TRUS), but 16 of 61
(26%) were identified to have extraprostatic cancer in the seminal vesicles (8 of
61, 13%) or in the neurovascular bundles (8 of 61, 13%) by extraprostatic biopsy.
There was no significant difference in the complication rates between sextant
intraprostatic biopsy and sextant intraprostatic plus extraprostatic biopsy
(p>0.97). CONCLUSIONS: Extraprostatic biopsy identifies extension of carcinoma in
a large proportion of patients in whom clinical evaluation by DRE and TRUS
indicates organ-confined disease. Extraprostatic biopsy is therefore warranted as
routine evaluation before surgery in order to correctly stage prostatic carcinoma
and select appropriate therapy.
PMID- 10786923
TI - Answer to case of the month #76. Amniotic band syndrome.
PMID- 10786921
TI - Metallic stents in the treatment of duodenal obstruction: technical issues and
results.
AB - OBJECTIVE: To evaluate the efficacy of duodenal stenting procedures and to review
technical issues with these procedures in a series of cases over a 1-year period.
METHODS: Expandable metallic stents (Wallstents) of varying sizes were introduced
and deployed in 4 patients (1 man and 3 women 42 to 81 years of age). Each
patient underwent a separate method of stent introduction with either
fluoroscopic or endoscopic guidance, either perorally, transgastrically and
transhepatically. RESULTS: All procedures were technically successful, allowing
patients to continue eating normally. In 1 patient, stent foreshortening
necessitated the introduction of a second stent. Another patient experienced
transient stent obstruction by food; this resolved spontaneously and required no
additional intervention. Based on the patients' continuing ability to tolerate
food, it was believed that the stents remained patent until the time of death
(from 3 days to 9 weeks with a mean of 5.25 weeks). CONCLUSIONS: Duodenal
stenting procedures provide a relatively new, technically feasible and
efficacious method of managing duodenal obstructions, especially in patients who
are poor candidates for surgery.
PMID- 10786925
TI - Metabolic effects of L-carnitine on prepubertal rat Sertoli cells.
AB - The role of carnitine on Sertoli cell metabolism was investigated. Carnitine
effects on Sertoli cell lipid metabolism were evaluated by measuring the
intracellular levels of non-esterified fatty acids (NEFA) and ketone bodies. The
concentration of NEFA in Sertoli cell cultured in the presence of carnitine is
significantly reduced as compared to control, while, no significant changes were
observed in the concentration of ketone bodies. The functional parameters
evaluated to assess the influence of carnitine on Sertoli cell carbohydrate
metabolism, i.e., lactate and pyruvate production, lactate dehydrogenase activity
and hexose transport, were all significantly increased following carnitine in
vitro supplementation. Thus, carnitine appears to drive Sertoli cell intermediary
metabolism in an intimately interrelated way, stimulating both fatty acid
breakdown and glycolysis. Our results indicate that Sertoli cells are a possible
target for a widespread metabolic action of carnitine and strongly support the
involvement of carnitine in the regulation of Sertoli cell functions which are
related with germ cell "nutrition", convincingly suggesting a direct influence of
the compound at testis level.
PMID- 10786926
TI - Mutated human beta3-adrenergic receptor (Trp64Arg) lowers the response to beta3
adrenergic agonists in transfected 3T3-L1 preadipocytes.
AB - Wild-type or mutated human beta3-adrenergic receptor (Trp64Arg) cDNAs were stably
expressed in mouse 3T3-L1 cells. Saturation binding study using a beta-adrenergic
ligand revealed that there was no significant difference in the receptor density
and the equilibrium dissociation constant between the two cell lines. However,
the ability of the mutant beta3-adrenergic receptor to accumulate cyclic AMP
(cAMP) in response to isoproterenol was much reduced and Kact for cAMP
accumulation was lowered as compared to the wild type receptor. The amount of
alpha subunit of stimulatory GTP-binding protein (GSalpha) and adenylyl cyclase
activity in response to forskolin were not different in the two cell lines. The
responses of the mutant receptor to epinephrine, norepinephrine and L-755,507, a
highly specific agonist for human beta3-adrenergic receptor, were also reduced,
but the reduction of Kact for L-755,507 was more evident than other agonists
tested. The cAMP accumulation in response to some conventional beta3 agonists was
less than 10% of that to isoproterenol even in the cells expressing the wild type
receptor. These results suggest that the Trp64Arg mutant beta3-adrenergic
receptor has less ability to stimulate adenylyl cyclase, and that lipolytic
activity through the beta3-adrenergic receptor by catecholamines in subjects
carrying this mutation might be suppressed.
PMID- 10786927
TI - Immaturity of glucose-induced insulin secretion in fetal rat islets is due to low
glucokinase activity.
AB - Fetal pancreatic islets show a deficiency in insulin secretion in response to
glucose, but the underlying mechanism is disputed. By isolating pancreatic islets
from 21-day pregnant rats and culturing them with 2.8 or 11.1 mM glucose for 7
days, we attempted to clarify the involvement of low glucokinase activity in the
poor glucose response in islets cultured with 2.8 mM glucose relative to the
response obtained from those cultured with 11.1 mM glucose. The insulin secretion
induced by 10 mM glyceraldehyde or 15 mM leucine, but not that induced by 20 mM
glucose, from islets cultured with 2.8 mM glucose was higher than the basal
insulin secretion, suggesting that the defect in glucose stimulation in fetal
islets may be localized somewhere before the glyceraldehyde 3-phosphate step in
the glycolytic pathway. When islets cultured with 11.1 mM glucose as distinct
from those cultured with 2.8 mM glucose were incubated with glucose, the
glycolytic intermediate contents were increased in a concentration- and time
dependent manner. Utilization of glucose at 20 mM, but not at 5 mM, in islets
cultured with 11.1 mM glucose was higher than that in islets cultured with 2.8 mM
glucose. The Vmax value of glucokinase, but not that of hexokinase or aldolase,
in islets cultured with 11.1 mM glucose was higher by 150% than that in islets
cultured with 2.8 mM glucose. The results suggest that the poor secretion of
insulin in response to glucose can be explained by insufficient glucose
metabolism due to the low glucokinase activity.
PMID- 10786928
TI - Glucose-induced insulin mRNA accumulation is impaired in islets from neonatal
streptozotocin-treated rats.
AB - According to the glucose toxicity hypothesis, hyperglycemia contributes to
defective beta-cell function in type 2, non-insulin-dependent diabetes mellitus.
This concept is supported by substantial data in rodent models of diabetes.
However, the ability of glucose to stimulate the accumulation of insulin mRNA, a
critical feature of normal beta-cell physiology, has not been investigated in in
vivo models of chronic hyperglycemia. The aim of this study was to determine
whether glucose-induced insulin mRNA accumulation is impaired in the neonatal
streptozotocin-treated rat (n0-STZ rat), a model of non-obese, non-insulin
dependent diabetes mellitus. Islets of Langerhans isolated from n0-STZ and
control rats were cultured for 24 h in the presence of 2.8 or 16.7 mmol/L
glucose, and insulin mRNA levels were measured by Northern analysis. Insulin mRNA
levels were increased more than twofold by glucose in control islets. In
contrast, no significant effect of glucose was found on insulin mRNA levels in n0
STZ islets. We conclude that insulin gene regulation by glucose is impaired in n0
STZ rat islets.
PMID- 10786929
TI - Zinc effects on hyperglycemia and hypoleptinemia in streptozotocin-induced
diabetic mice.
AB - Zinc has an antihyperglycemic effect. Zinc can also influence the production of
leptin, a satiety factor that reduces appetite and blood sugar level. In this
study, we investigated the effect of zinc supplementation on food intake and
circulating leptin and glucose concentrations in streptozotocin-induced diabetic
mice. Male diabetic mice received zinc supplementation (20 ppm) from drinking
water for two weeks. The results showed that zinc treatment did not affect body
weight gain, body fat content or food intake in these diabetic mice. However,
zinc supplementation markedly ameliorated the hyperglycemia of diabetic mice.
After zinc treatment, serum leptin concentrations tended to increase in the
diabetic mice. This study suggests that zinc is a mediator of leptin production.
PMID- 10786930
TI - Insulin sensitivity in normotensive offspring of hypertensive parents.
AB - OBJECTIVES: To investigate the insulin sensitivity in normotensive offspring of
hypertensive parents. SUBJECTS: Fifteen young normotensive offspring of
hypertensive parents were paired with 15 controls matched for age, sex and body
mass index. METHODS: The insulin sensitivity was investigated by 75 g oral
glucose tolerance test (OGTT) and modified insulin suppression test. A high-fat
mixed meal was administered to observe the changes of TG levels. RESULTS: The
plasma glucose and serum insulin responses to oral glucose challenge were
comparable between both groups. High-fat mixed meal made no difference in the
plasma glucose, serum triglyceride or insulin between the 2 groups. With the
modified insulin suppression test, the steady-state plasma glucose levels (SSPG)
were higher in the offspring of parents with essential hypertension (138+/-43
mg/dl) than in the control group (95+/-26 mg/dl). The diastolic blood pressure
and heart rate of the offspring of hypertensive parents are also higher than the
control group. CONCLUSIONS: Insulin resistance exists in young normotensive
offspring of hypertensive parents, and the impairment of insulin-mediated glucose
uptake in these subjects develop before any alteration of fasting and
postprandial triglyceride.
PMID- 10786931
TI - Reversibility of autonomic nerve function in relation to rapid improvement of
glycemic control.
AB - To determine the reversibility of autonomic nerve function in relation to the
rapid improvement of glycemic control, we studied 54 patients with type 2
diabetes mellitus (33 men and 21 women; mean age, 49+/-8 years; mean duration of
diabetes, 10+/-7 years). For 4 weeks of admission, the subjects were placed on
strict dietary therapy, and 10 of them were under dietary therapy, 16 initially
continued treatment with oral hypoglycemic agents, while 28 were treated with
insulin. We measured the dark-adapted pupillary area (DAPA) by infrared
photography, an indicator of diabetic autonomic neuropathy, on the second and
28th day after hospitalization. The change in FPG (delta FPG = - 111+/-49 mg/dl;
mean +/- SD, p<0.001) and the change in HbA1c (delta HbA1c = -1.3+/-0.3%,
p<0.001) were significantly improved. We observed significant improvements in the
change in DAPA (delta DAPA) of all patients (25.1+/-11.0 vs. 25.7+/-11.6 mm2,
delta DAPA = 0.6+/-1.4 mm2, p<0.01) and in those of patients without retinopathy
(delta DAPA = 1.0+/-0.6 mm2, p<0.01). No change was observed in those of patients
with retinopathy (delta DAPA= -0.02+/-0.3 mm2, NS). The delta DAPA was related to
the delta HbA1c (r = -0.479, p<0.001) and also to the diabetic duration (years, r
= -0.517, p<0.001). These findings suggest that a rapid improvement of glycemic
control improves autonomic nerve function observed in type 2 diabetes with
shorter duration. Particular attention should be paid to maintaining strict
glycemic control at the stage of diabetic patients without retinopathy and those
with shorter duration.
PMID- 10786932
TI - Stimulation of insulin synthesis and release by alpha-D-glucose pentaacetate in
pancreatic islets from human subjects.
PMID- 10786933
TI - Cancer chemoprevention by tea polyphenols.
AB - Tea is one of the most widely consumed beverages, second only to water. Many
experimental researches in laboratory animals demonstrated that tea components
had an inhibitory effect on carcinogenesis at a number of organ sites. The
inhibitory effects of tea against carcinogenesis have been attributed to the
biologic activities of the polyphenol fraction in tea. This review summarizes
experimental data on chemopreventive effects of tea polyphenols in various tumor
bioassay systems. Many laboratory studies have demonstrated the inhibitory
effects of green tea polyphenols, especially (-)-epigallocatechin-3-gallate
(EGCG), on carcinogenesis in animals models. The majority of these studies have
been conducted in mouse skin tumor models, where tea polyphenols were used either
as oral feeding in drinking water or in direct local application. Most studies
used 12-O-tetradecanoylphorbol-13-acetate (TPA) or ultraviolet (UV) radiation as
the tumor promoter and found anticarcinogenic effects caused by green tea
polyphenols. Black tea was also found to be effective, although the activity was
weaker than that of green tea in some experiments. Other studies showed that
black tea polyphenols-theaflavins exhibited stronger anticarcinogenic activity
than did EGCG. Caffeine in tea was also important for tea to prevent
tumorigenesis. The molecular mechanisms of the cancer chemopreventive effects of
tea polyphenols are not completely understood. They are most likely related to
the mechanisms of biochemical actions of tea polyphenols, which include
antioxidative activities, modulation of xenobiotic metabolite enzymes and
inhibition of tumor promotion. In addition, we have also proposed that tea
polyphenols function as cancer chemopreventive agents through modulation of
mitotic signal transduction. However, the molecular mechanisms involved in this
modulation need further investigation.
PMID- 10786934
TI - Immunohistochemical study of opioid receptors after chronic morphine treatment in
rats.
AB - Previously, we have used the biochemical receptor binding method to investigate
whether down-regulation of the opioid receptor is a mechanism for morphine
tolerance, and we were led to a negative conclusion. In the current study, we
further used immunohistochemistry to reinvestigate this issue. Male Sprague
Dawley rats (250-300 g) were chronically treated with morphine s.c. for 2, 4 or 6
days, using an escalating dosage paradigm (5-45 mg), which resulted in a 1.8 to
4.0-fold increase in AD50. Rat brains were removed, frozen, coronally sectioned
(14 microm) and processed for mu- or delta-opioid receptor immunohistochemistry
using the Avidin-Biotin Complex (ABC) method. No significant decrease in mu
opioid receptor (MOR) immunodensity was found in most of the brain regions, which
were enriched with MOR after chronic treatment with morphine except for the
anteroventral thalamic nucleus in the ventrolateral part (AVVL). No significant
change in delta-opioid receptor (DOR) immunodensity after chronic treatment with
morphine was found either. Therefore, our conclusion is that down regulation of
opioid receptors may not be an important mechanism for morphine tolerance.
PMID- 10786935
TI - Characterization of novel 10-substituted 1,8-dihydroxy-9(10H)-anthracenone
derivatives by mass spectrometry.
AB - Anthralin and its derivatives containing a variety of simple or functionalized
aliphatic and aromatic substituents are of special interest in research on
psoriasis. In this connection, 10-arylthio-1,8-dihydroxy-9(10H)-anthracenones
were synthesized and examined by means of mass spectrometry. In general, the
molecules in question fragmented upon electron impact into ions at m/z 225 (C-S
bond cleavage and charge retention at the anthralin component) and into ions of
unknown structure at m/z 226, requiring H-migration from the S-bound substituent
R into the anthralin moiety. Since mass spectrometry methods furnished us
elegant, matchless means of tracing the amounts of material in the analysis,
especially in the case of physiologically active compounds, we decided to use
mass spectrometry procedures for unequivocal identification and purity
determination of 10-arylthio-anthralins.
PMID- 10786936
TI - Influences on water intake in the rat after lesions of the septal subareas.
AB - It has been suggested that the septum plays an inhibitory role in the behavioral
function. Recent work has shown that the septum is heterogeneous from the
neuroanatomical perspective. The present study examined the water intake of rats
lesioned with kainic acid (0.5 microg/0.5 microl/site) on three septal
subregions: anterior medial (MSa), posterior medial (MSp), and lateral (LS)
sites. Drinking volume was enhanced mostly in rats with the MSp lesion, and so
was locomotor activity. However, these two measures were not significantly
correlated. This polydipsia induced by MSp lesion was also found in a chronic
domain. Another experiment further determined the dipsogenic effects of
polyethylene glycol (PEG; 20%) and hypertonic saline (1 M NaCl) in MSp lesioned
rats. Water intake increased significantly after administration of the hypertonic
saline treatment, but not after injection of PEG. However, this disparity
approached a nonsignificant level 8 hr after thirst challenges were conducted. In
addition to revealing septal hyperdipsia. these data suggest that the septal
subareas can be functionally heterogeneous in drinking behavior. The dipsogenic
response profiles for the cellular and extracellular thirst challenges could be
differentially affected by kainate lesion in the MSp.
PMID- 10786938
TI - Male-specific band in random amplified microsatellite polymorphism fingerprints
of Holstein cattle.
AB - A total of 65 blood samples collected from Holstein cattle were employed for DNA
extraction. Genomic DNA were amplified by means of random amplified polymorphic
DNA (RAPD). One hundred and one random primers (Operon kits OPAA, OPAO, OPAV,
OPC, OPE and OPA-06) were used for polymerase chain reactions (PCR). The PCR
products were size fractionated by means of electrophoresis in agarose gel,
transferred to a nylon membrane, and then hybridized with a alpha-32P-labeled
microsatellite probe for random amplified microsatellite polymorphism (RAMPO)
analysis. All the primers produced many amplification patterns in RAMPO
fingerprints, but only OPE-01 (5'-CCCAAGGTCC-3') yielded a male-specific strong
signal. Among the 65 cases, the specific band could be observed in the RAMPO
fingerprints of the 24 male samples but not in the 41 female samples. Therefore,
this specific band is peculiar to male cattle.
PMID- 10786937
TI - Gel-filtrated fractions of alveolar bone extract contain factors promoting cell
attachment and a mitogenic effect on periodontal ligament fibroblasts.
AB - The purpose of this study was to investigate the effect of acetic acid-extracted
bone proteins on human periodontal ligament fibroblasts (hPF) with respect to
mitogenic and cell attachment promoting activity. Alveolar bone was harvested
from healthy donors and subjected to 0.5 M acetic acid extraction, dialysis and
lyophilization, and gel filtration. Promotion of cell attachment and stimulation
of DNA synthesis by the crude extract and gel-filtrated fractions were studied in
cultured hPE Many protein components, varying in molecular weight from 10-14 to
120 kDa, were detectable in 10% SDS-PAGE of the extract. Gel filtration of bone
extract disclosed four fractions with molecular weights of 55, 34, 29 and 19-20
kDa. Both the 34 and 55 kDa fractions at a concentration of 5 microg/ml, but not
the 29- or 19-20 kDa fractions, were found to promote cell attachment while only
the 55 kDa fraction (5 microg/ml) stimulated DNA synthesis of hPF, Both mitogenic
activity and the promotion of the cell attachment by gel-filtrated active
fractions were resistant to thermal treatment (70 degrees C) and pH (4 to
approximately 8) changes. These findings suggest that acetic acid extract of
alveolar bone may contain components which are capable of modulating cell
attachment and mitogenesis of hPF.
PMID- 10786939
TI - Chemical signaling processes in the marine environment.
AB - Understanding the mechanisms by which environmental chemical signals, chemical
defenses, and other chemical agents mediate various life-history processes can
lead to important insights about the forces driving the ecology and evolution of
marine systems. For chemical signals released into the environment, establishing
the principles that mediate chemical production and transport is critical for
interpreting biological responses to these stimuli within appropriate natural,
historical contexts. Recent technological advancements provide outstanding
opportunities for new discoveries, thus allowing quantification of interactions
between hydrodynamic, chemical, and biological factors at numerous spatial and
temporal scales. Past work on chemically mediated processes involving organisms
and their environment have emphasized habitat colonization by larvae and trophic
relationships. Future research priorities should include these topics as well as
courtship and mating, fertilization, competition, symbiosis, and microbial
chemical ecology. There are now vast new opportunities for determining how
organisms respond to chemical signals and employ chemical defenses under
environmentally realistic conditions. Integrating these findings within a larger
ecological and evolutionary framework should lead to improved understanding of
natural physicochemical phenomena that constrain biological responses at the
individual, population, and community levels of organization.
PMID- 10786940
TI - The fluid dynamical context of chemosensory behavior.
AB - The fluid mechanical environment provides the context in which denizens of
aquatic realms, as well as terrestrial creatures, use chemoperception to search
for objects. Our ability to understand the nature of olfactory-guided navigation
rests on our proficiency at characterizing the fluid dynamic setting and at
relating properties of flow to behavioral and sensory mechanisms. This work
reviews some fluid dynamical concepts that are particularly useful in describing
aspects of flow relevant to chemosensory navigation, and it considers studies of
orientation in animals in light of these principles. Comparisons across broadly
different fluid environments suggest that particular sensory and behavioral
mechanisms may be tailored to specific flow regimes and stimulus environments.
This is clearly evident when examining animals that operate in high vs. low
Reynolds number flows. In other cases, animals may converge on common solutions
in given flow regimes in spite of differences in taxonomic class or size.
Potential parallels may include behavior of aquatic vs. terrestrial arthropods,
and animals without fixed reference points in flows dominated by molecular vs.
turbulent diffusion. In an effort to add further fluid dynamical underpinnings to
navigational strategies, I suggest how simple nondimensional categorization of
behavior in relation to flow may aid in identifying the forces underlying common
elements, even across animals of seemingly disparate size and scale.
PMID- 10786941
TI - Mechanisms of animal navigation in odor plumes.
AB - Chemical signals mediate many of life's processes. For organisms that use these
signals to orient and navigate in their environment, where and when these cues
are encountered is crucial in determining behavioral responses. In air and water,
fluid mechanics impinge directly upon the distribution of odorous molecules in
time and space. Animals frequently employ behavioral mechanisms that allow them
to take advantage of both chemical and fluid dynamic information in order to move
toward the source. In turbulent plumes, where odor is patchily distributed,
animals are exposed to a highly intermittent signal. The most detailed studies
that have attempted to measure fluid dynamic conditions, odor plume structure,
and resultant orientation behavior have involved moths, crabs, and lobsters. The
behavioral mechanisms employed by these organisms are different but generally
integrate some form of chemically modulated orientation (chemotaxis) with a
visual or mechanical assessment of flow conditions in order to steer up-current
or upwind (rheo- or anemo-taxis, respectively). Across-stream turns are another
conspicuous feature of odor-modulated tracks of a variety of organisms in
different fluid conditions. In some cases, turning is initiated by detection of
the lateral edges of a well-defined plume (crabs), whereas in other animals
turning appears to be steered according to an internally generated program
modulated by odor contacts (moth counterturning). Other organisms such as birds
and fish may use similar mechanisms, but the experimental data for these
organisms is not yet as convincing. The behavioral strategies employed by a
variety of animals result in orientation responses that are appropriate for the
dispersed, intermittent plumes dictated by the fluid-mechanical conditions in the
environments that these different macroscopic organisms inhabit.
PMID- 10786942
TI - Life in transition: balancing inertial and viscous forces by planktonic copepods.
AB - Copepods (1-10 mm aquatic crustaceans moving at 1-1000 mm s(-1)) live at Reynolds
numbers that vary over 5 orders of magnitude, from 10(-2) to 10(3). Hence, they
live at the interface between laminar and turbulent regimes and are subject to
the physical constraints imposed by both viscous and inertial realms. At large
scales, the inertially driven system enforces the dominance of physically derived
fluid motion; plankton, advected by currents, adjust their life histories to the
changing oceanic environment. At Kolmogorov scales, a careful interplay of evenly
matched forces of biology and physics occurs. Copepods conform or deform the
local physical environment for their survival, using morphological and behavioral
adaptations to shift the balance in their favor. Examples of these balances and
transitions are observed when copepods engage in their various survival tasks of
feeding, predator avoidance, mating, and signaling. Quantitative analyses of
their behavior give measures of such physical properties of their fluid medium as
energy dissipation rates, molecular diffusion rates, eddy size, and eddy
packaging. Understanding the micromechanics of small-scale biological-physical
chemical interactions gives insight into factors influencing large-scale dynamics
of copepod distribution, patchiness, and encounter probabilities in the sea.
PMID- 10786943
TI - The chemical defense ecology of marine unicellular plankton: constraints,
mechanisms, and impacts.
AB - The activities of unicellular microbes dominate the ecology of the marine
environment, but the chemical signals that determine behavioral interactions are
poorly known. In particular, chemical signals between microbial predators and
prey contribute to food selection or avoidance and to defense, factors that
probably affect trophic structure and such large-scale features as algal blooms.
Using defense as an example, I consider physical constraints on the transmission
of chemical information, and strategies and mechanisms that microbes might use to
send chemical signals. Chemical signals in a low Re, viscosity-dominated physical
environment are transferred by molecular diffusion and laminar advection, and may
be perceived at nanomolar levels or lower. Events that occur on small temporal
and physical scales in the "near-field" of prey are likely to play a role in cell
cell interactions. On the basis of cost-benefit optimization and the need for
rapid activation, I suggest that microbial defense system strategies might be
highly dynamic. These strategies include compartmented and activated reactions,
utilizing both pulsed release of dissolved signals and contact-activated signals
at the cell surface. Bioluminescence and extrusome discharge are two visible
manifestations of rapidly activated microbial defenses that may serve as models
for other chemical reactions as yet undetected due to the technical problems of
measuring transient chemical gradients around single cells. As an example, I
detail an algal dimethylsulfoniopropionate (DMSP) cleavage reaction that appears
to deter protozoan feeding and explore it as a possible model for a rapidly
activated, short-range chemical defense system. Although the exploration of
chemical interactions among planktonic microbes is in its infancy, ecological
models from macroorganisms provide useful hints of the complexity likely to be
found.
PMID- 10786944
TI - Olfactory foraging by Antarctic procellariiform seabirds: life at high Reynolds
numbers.
AB - Antarctic procellariiform seabirds forage over vast stretches of open ocean in
search of patchily distributed prey resources. These seabirds are unique in that
most species have anatomically well-developed olfactory systems and are thought
to have an excellent sense of smell. Results from controlled experiments
performed at sea near South Georgia Island in the South Atlantic indicate that
different species of procellariiforms are sensitive to a variety of scented
compounds associated with their primary prey. These include krill-related odors
(pyrazines and trimethylamine) as well as odors more closely associated with
phytoplankton (dimethyl sulfide, DMS). Data collected in the context of global
climatic regulation suggest that at least one of these odors (DMS) tends to be
associated with predictable bathymetry, including upwelling zones and seamounts.
Such odor features are not ephemeral but can be present for days or weeks. I
suggest that procellariiforms foraging over vast distances may be able to
recognize these features reflected in the olfactory landscape over the ocean. On
the large scale, such features may aid seabirds in navigation or in locating
profitable foraging grounds. Once in a profitable foraging area, procellariiforms
may use olfactory cues on a small scale to assist them in locating prey patches.
PMID- 10786945
TI - Endolithic fungi in reef-building corals (Order : Scleractinia) are common,
cosmopolitan, and potentially pathogenic.
PMID- 10786946
TI - Impact of a castrating trematode, Neophasis sp., on the common whelk, Buccinum
undatum, in the northern Gulf of St. Lawrence.
AB - We observed heavy trematode infections of whelks, Buccinum undatum, from the
Mingan Islands, eastern Canada, by larval stages of a species of Neophasis. Only
sexually mature whelks were infected, 23% of mature females and 15% of mature
males, and prevalence increased rapidly with whelk size. In most cases the
parasite completely occupied the gonad, causing castration. The digestive gland
was also infected, although to a lesser degree (0% to 50% occupation), and a
marked reduction in the mass of the penis was associated with the infection. A
decrease in the proportion of whelks with a highly infected digestive gland
between May and August 1994 suggested mortality of infected individuals. Whelks
held for 12 to 15 months in the laboratory retained the infection but did not
show significant mortalities (possibly because food was abundant and predators
absent). The larval stage of Neophasis sp. found in whelks was a cercaria;
however, the tail easily detached. The putative infective stage (metacercaria)
was not observed but may be present in whelks in late winter and early spring.
Other trematode parasites observed were adult Steringophorus furciger in the
stomach and larval Renicola sp. in the digestive gland.
PMID- 10786947
TI - Vacuolar-type ATPase in the accessory boring organ of Nucella lamellosa (Gmelin)
(Mollusca : Gastropoda): role in shell penetration.
AB - The structure and function of the accessory boring organ (ABO) of muricid
gastropods has been described in numerous studies, and the ABO of Nucella
lamellosa was found to be similar to those of other muricid species. The active
cap region of the ABO is composed of tall, mitochondria-rich cells with distinct
brush borders at their apicies, surrounding a hemolymph-containing central sinus.
Using antibodies specific for vacuolar-type ATPase (V-ATPase), enzyme
immunoreactivity was found to be limited to the brush border of the epithelial
cells. Electron immunohistochemistry revealed that V-ATPase immunoreactivity
resides in the plasma membranes of the microvilli. Immunodot blotting using yeast
V-ATPase as a positive control confirmed the specificity of the reactions. SDS
PAGE of membrane suspensions from the ABO revealed protein bands of the requisite
molecular weight for V-ATPase subunits. Western blots suggest that antibodies
raised against mammalian V-ATPase subunits recognize subunits of the molluscan V
ATPase. The molecular weights of these identified subunits are similar to those
in mammals. The V-ATPase-specific inhibitor bafilomycin A1 inhibited ATPase
activity in samples of ABO homogenate by about 10% relative to control, providing
further evidence for the presence of V-ATPase. Specific V-ATPase activity was
about 67 picomoles of inorganic phosphate per microgram of protein per minute in
the homogenate. Collectively this evidence strongly suggests that a vacuolar-type
proton transporting ATPase is present in the brush border of the accessory boring
organ of Nucella lamellosa, and is responsible for acidifying secretions from
this gland. Similarities between the ABO, osteoclasts, and the mantle of
freshwater bivalves also suggest that the mechanism for decalcification of
calcareous substrates is conserved.
PMID- 10786949
TI - Phylogeny of Gastrotricha: a morphology-based framework of gastrotrich
relationships.
AB - Currently, the phylum Gastrotricha is divided into the orders Macrodasyida and
Chaetonotida, with the structure of the myoepithelial pharynx being an important
distinguishing feature. Macrodasyida currently has six recognized families, and
Chaetonotida comprises seven families. However, within-group relationships are
poorly understood. To arrive at a better understanding of gastrotrich systematics
and phylogeny, we performed the first cladistic analysis of nearly all known
gastrotrich genera using 71 morphological characters. Results suggest that the
Gastrotricha is a monophyletic group (supported by 82% of bootstrap replications)
with its most primitive taxa distributed among the families Dactylopodolidae and
Neodasyidae. Monophyly of Macrodasyida and Chaetonotida was supported by 90% and
52% bootstrap replications, respectively. Within the Macrodasyida, the families
Dactylopodolidae, Turbanellidae, Macrodasyidae, and Thaumastodermatidae all
formed monophyletic clades. The families Planodasyidae and Lepidodasyidae were
paraphyletic. Among the Chaetonotida, the marine family Xenotrichulidae was
monophyletic, supported by 51% of bootstrap replications. A second clade
containing all freshwater families was supported by 62% bootstrap values.
However, Chaetonotidae were paraphyletic. Using this analysis as a framework, we
now can explore possible patterns of evolution within it, and arrive at a
consensus of the gastrotrich ground pattern. Moreover, in future molecular
studies of metazoan phylogeny, we will be able to select gastrotrich species that
are more appropriate representatives of the phylum.
PMID- 10786948
TI - Light-limitation on predator-prey interactions: consequences for metabolism and
locomotion of deep-sea cephalopods.
AB - The present study attempts to correlate the metabolism and locomotory behavior of
25 species of midwater Cephalopoda from California and Hawaii with the maximal
activities of key metabolic enzymes in various locomotory muscle tissues. Citrate
synthase (CS) and octopine dehydrogenase (ODH) activities were used as indicators
of aerobic and anaerobic metabolic potential respectively. CS activity in mantle
muscle is highly correlated with whole-animal rates of oxygen consumption,
whereas ODH activity in mantle muscle is significantly correlated with a species'
ability to buffer the acidic end-products of anaerobic metabolism. Both CS and
ODH activities in mantle muscle declined strongly with a species' habitat depth.
For example, CS and ODH activities ranged respectively from 0.04 units g(-1) and
0.03 units g(-1) in the deep-living squid Joubiniteuthis portieri, to 8.13 units
g(-1) and 420 units g(-1) in the epipelagic squid Sthenoteuthis oualaniensis. The
relationships between enzymatic activities and depth are consistent with similar
patterns observed for whole-animal oxygen consumption. This pattern is believed
to result from a relaxation, among deep-living species, in the need for strong
locomotory abilities for visual predator/prey interactions; the relaxation is due
to light-limitation in the deep sea. Intraspecific scaling patterns for ODH
activities may, for species that migrate ontogenetically to great depths, reflect
the counteracting effects of body size and light on predator-prey detection
distances. When scaled allometrically, enzymatic activities for the giant squid,
Architeuthis sp., suggest a fairly active aerobic metabolism but little burst
swimming capacity. Interspecific differences in the relative distributions of
enzymatic activities in fin, mantle, and arm tissue suggest an increased reliance
on fin and arm muscle for locomotion among deep-living species. We suggest that,
where high-speed locomotion is not required, more efficient means of locomotion,
such as fin swimming or medusoid arm propulsion, are more prevalent.
PMID- 10786950
TI - Introduction--infection and critical illness: genetic and environmental aspects
of susceptibility and resistance.
PMID- 10786952
TI - Mechanisms of resistance to antibiotics.
PMID- 10786951
TI - Microbial resistance: lessons from the EPIC study. European Prevalence of
Infection.
AB - In 1992, a one day point prevalence study (EPIC) was conducted in European
intensive care units (ICUs) to determine the prevalence of nosocomial infection
among ICU patients. Of the 10,038 patients included, 45% were infected and 21%
had a nosocomial ICU-acquired infection. Many of the organisms responsible for
these infections were resistant to commonly used antibiotics. For example, 60% of
the Staphylococcus aureus isolated were resistant to methicillin and 46% of
Pseudomonas aeruginosa were resistant to gentamicin. The incidence of nosocomial
infection varied between countries as did the incidence of antibiotic resistance.
Mortality rates were higher in countries with higher rates of nosocomial
infection and higher again in those countries with higher rates of resistant
organisms. Antibiotic resistance is rising and clearly efforts to contain its
development and spread are vital. Basic infection control procedures such as hand
washing must be developed and implemented, and antibiotic prescribing needs to be
rationalized. The international variations in resistance rates, even within
Europe, highlight the importance of being familiar with local resistance patterns
when prescribing. The assistance of an infectious diseases specialist can be
invaluable in providing a global overview of the local microbial milieu and of
antibiotic resistance patterns. Epidemiological studies of this sort can provide
useful information which can be used to stimulate debate on the reasons behind
regional differences in infection and help in the development of strategies to
combat the rising tide of microbial antibiotic resistance.
PMID- 10786953
TI - Epidemiology of antibiotic resistance.
AB - Three biological processes contribute to the accumulation of bacterial drug
resistance: new selection, gene epidemics and strain epidemics. New resistance
emerges by (i) the advantaging of entire species, (ii) by mutation, and (iii) by
the escape of resistance genes to mobile DNA. Organisms to have 'benefited' from
modern patterns of cephalosporins and quinolone use include enterococci,
Clostridium difficile, coagulase-negative staphylococci and Enterobacter spp.
Mutational resistance notoriously occurs with certain antibiotic/organism
combinations and allows rapid multifocal accumulation of resistance. At worst,
therapy can fail when resistant mutants are selected in individual patients.
Escape of new genes to mobile DNA is rare but, having occurred, permits massive
'gene epidemics', as the same genes and plasmids spread into diverse pathogens.
Strain epidemics notoriously occur in individual units, reflecting break-downs of
hygiene. Some strains achieve a much wider distribution: thus, much of the MRSA
problem in the UK depends on the dissemination of two epidemic strains, EMRSA15
and 16; penicillin resistant pneumococci of serotypes 6 and 23 have disseminated
internationally from Spain and a serotype K25 strain of Klebsiella pneumoniae
with SHV-4 beta-lactamase has spread widely in France. It remains unknown why
some strains and genes achieve wide spread whereas others, equally resistant,
fail to do so. There is no simple cure for resistance but the best opportunities
for control lie in lesser and better use of antibiotics backed by swifter and
more accurate microbiology; in developing new antibiotics; and in protecting old
ones from resistance determinants. All this must be supported by good local
knowledge of the epidemiology of infections and resistance and of the likelihood
of particular antibiotics to select resistance.
PMID- 10786954
TI - Prevention and control of infections in intensive care.
AB - Small intensive care units (ICUs) functioning within their capacity and caring
mainly for post-operative patients have fewer problems with infection control
than larger ICUs with a varied case mix, sub-optimal staffing levels, and high
levels of antibiotic consumption. Under these circumstances chronic cross
colonisation and infection are inevitable and outbreaks may occur. Little can be
done to reduce the risks of infection which arise as a direct result of the
patient's clinical condition and prior colonisation status. However, selection
pressure from antibiotic usage can be modified, as can environmental hygiene,
ventilation and architectural design. One of the simplest measures for reducing
cross infection remains one of the most intractable: compliance by staff with
protocols and standards for maintaining hand hygiene. Simplification of
procedures by the ready availability of alcohol hand rub preparations with or
without chlorhexidine may improve matters.
PMID- 10786955
TI - Antibiotic usage and prescribing policies in the intensive care unit.
PMID- 10786956
TI - Ventilator associated pneumonia: perspectives on the burden of illness.
AB - OBJECTIVE: The objective of this narrative review is to summarize selected
current concepts and clinical evidence regarding the burden of illness of VAP,
including its epidemiology, diagnosis, attributable mortality and risk factors.
DATA SOURCES & SELECTION: Studies were identified through MEDLINE, EMBASE,
bibliographies of primary and review articles and personal files. RESULTS: While
cross sectional studies inform us about VAP prevalence, longitudinal studies
inform us of the cumulative risk and conditional risk of developing VAP. Reported
VAP rates are modulated by factors related to case mix, causative microorganisms,
interventions that influence risk over time, and VAP definitions employed.
Population-specific and organism-specific VAP rates are needed to avoid
misleading benchmarking between different ICUs, and to minimize inappropriate
between-study comparisons. Observational studies have shown that invasive
sampling techniques versus non-invasive approaches to diagnose VAP facilitates
more targeted antibiotic treatment; however, the influence of the diagnostic
method on endpoints such as mortality is less clear. VAP is associated with
approximately a 4 day increase in length of ICU stay and an attributable
mortality of approximately 20-30%. Fixed VAP risk factors include underlying
cardiorespiratory disease, neurologic injury and trauma. Modifiable VAP risk
factors include supine body position, witnessed aspiration, paralytic agents and
antibiotic exposure. If modifiable risk factors tested in randomized trials lower
VAP rates, such as semirecumbency versus supine positioning, these represent
effective VAP prevention strategies. CONCLUSIONS: Ventilator-associated pneumonia
is a major morbid outcome among critically ill patients. Studies evaluating more
effective prevention and treatment strategies are needed.
PMID- 10786957
TI - Antibiotic prophylaxis in intensive care units: meta-analyses versus clinical
practice.
AB - OBJECTIVE: At least 7 meta-analyses (MA) have been published since 1991 on the
effectiveness of antibiotic prophylaxis in Intensive care units (ICU) patients,
but controversy still remains about the overall effectiveness and risk-benefits
profile of the treatment. This paper aims to summarise available data on
effectiveness and discuss reasons why the controversy is still open and possible
directions for future research. DESIGN: Review of available published MA on the
effectiveness of various regimens of antibiotic prophylaxis with particular
emphasis on the results of the individual patient data analysis published in
1998. SETTING: MA or randomised control trials (RCTs), published and unpublished,
conducted anywhere in the world. PATIENTS AND PARTICIPANTS: Unselected adult ICU
populations included in studies, published and unpublished, comparing different
forms of antibiotic prophylaxis. MAIN OUTCOME MEASURE: Respiratory tract
infections (RTIs) - however defined in individual studies - and total mortality.
DATA SOURCES: General information from the 7 MAs published between 1991 and 1999
and detailed information from the MA published in the British Medical Journal in
1998 that reported data on 5727 patients enrolled in 33 RCTs; access to
individual patients data could be obtained from 25 of 33 RCTs and allowed a
confirmatory individual patient MA on 4343 patients. RESULTS: Pooled estimates
from 16 RCTs (including 3361 patients) testing the effect of the topical and
systemic antibiotic combination indicates a significant reduction of both RTIs
(OR=0.35, 95% CI=0.29-0.41) and total mortality (OR=0.80, 95% CI=0.69-0.93). Five
and 23 patients need to be treated to prevent one infection and one death,
respectively, using this treatment. Pooled data from the 17 RCTs (including 2366
patients) testing the effect of a regimen based on topical antimicrobials
indicated a statistically significant reduction in RTIs (OR=0.57, 95% CI=0.46
0.69) but not in total mortality (OR=1.01; 95% CI=0.84-1.22). Individual patient
data analyses confirmed these results. CONCLUSIONS: After over 30 RCTs and seven
MAs, there is strong evidence that antibiotic prophylaxis can reduce both RTIs
and total mortality in ICUs patients in a statistically and clinically
significant way. Concerns about the possible occurrence of antimicrobial
resistance are not supported by available data but cannot, at the same time, be
ruled out due to methodologic inadequacies of the studies carried out so far.
Whether new trials are needed, and how they should be designed to answer the
question of the potential for antibiotic resistance following widespread use of
the treatment, are now the main issues to be settled. Convening an international
panel of clinical experts and methodologists could be appropriate, in order to
explore the best way to resolve the controversy that seems to be preventing the
widespread use of a treatment that the best analysis of available data now
indicates is effective.
PMID- 10786958
TI - Intravascular catheter-related sepsis--novel methods of prevention.
AB - Intravascular catheter-related sepsis continues to cause a significant degree of
morbidity and mortality, and accounts for the majority of staphylococcal
bacteraemias and septicaemias in hospitalised patients. Methods designed to
prevent these infections include those directed at aseptic techniques involving
the patient and improvements in catheter design. More recently catheters which
are either coated or have incorporated into their polymers antimicrobial agents
have been developed. The antimicrobial agents have included both antimicrobials
which are used to treat infections as well as antiseptics. The antimicrobial
catheters currently available appear to only give protection for relatively short
periods of time (approximately 14 days). The use of these antimicrobial catheters
needs to be restricted to the situation where infection rates and the risk to the
patient of sepsis are relatively high. Further novel approaches for the
prevention of these infections include the combination of low voltage electric
current together with antimicrobials; these await clinical evaluation.
PMID- 10786959
TI - The detection and interpretation of endotoxaemia.
AB - A considerable body of evidence has accumulated that implicates endotoxin in the
pathogenesis of the sepsis syndrome. This has raised interest in the possibility
of measuring endotoxin as a surrogate marker of Gram negative infection,
particularly since conventional microbiological tests have an inevitable delay.
The Limulus amoebocyte lysate (LAL) assay has been used most widely to measure
endotoxin in clinical samples. However, there are several important limitations
that need to be borne in mind. These include the dangers of contamination, lack
of precision and accuracy, and both false positive and false negative results.
Endotoxaemia is present in the blood of about 30% of patients with bacteraemia,
but endotoxaemia does not predict either Gram negative bacteraemia or Gram
negative infection, nor does it predict survival from sepsis. There is some
correlation with severity of sepsis, but the level of precision is poor. At the
present time, there is no place for routine endotoxin testing in clinical
practice. In particular, the positive predictive value of the test is
insufficiently high to be of clinical use. It may be that the LAL assay, or one
of the newer developments, may be more useful in excluding Gram negative
infection, but that remains to be shown.
PMID- 10786960
TI - Susceptibility to critical illness: reserve, response and therapy.
AB - Risk of critical illness is determined both by genetic and environmental
influences, particularly those relating to infectious and cardiovascular
diseases. Physiologically-based scoring systems cannot measure prior risk because
they do not quantify physiological reserve independently of the acute illness.
Genetic profiling could be useful for risk assessment. Early detection of
critical illness involves identifying physiological 'triggers' for referral; this
requires the education of nursing and medical staff in their significance.
Analysis of the relationship between risk factors and interventions may need
complex modelling techniques. Therapeutic strategies depend on the nature of the
underlying problem: the most useful are likely to be those which enhance tissue
oxygen delivery and resistance to infection.
PMID- 10786962
TI - Clinical trials of mediator-directed therapy in sepsis: what have we learned?
AB - Almost 60 randomized controlled clinical trials have been undertaken, testing the
hypothesis that modulation of the endogenous host inflammatory response can
improve survival for patients with a clinical diagnosis of sepsis. The results
have been tantalizing, but frustrating, and no new agent has been introduced into
clinical practice. Analysis of pooled data from studies of the use of an
neutralizing antibody to tumor necrosis factor, or recombinant interleukin 1
receptor antagonist, show that these two approaches yield a statistically
significant, but small improvement in 28 day all-cause mortality. However
variability in results from one study to the next, the small absolute mortality
reduction, the emerging evidence of a substantial potential for harm, and the
predicted costs of recombinant biologic agents has engendered a climate of
caution and pessimism. The challenge is to find methods of refining investigative
approaches to maximize benefit and minimize harm. This paper reviews the recent
history of sepsis clinical trials, focussing on emerging insights into the
limitations of study entry criteria and measures of biologic activity and
clinical benefit that may inform and direct future investigations. The biologic
complexity of systemic inflammation, and the multiple interactions between
clinical biology and the process of care suggest that future success in clinical
research in sepsis will occur through the conduct of highly focussed
investigations in a small number of dedicated centres of excellence.
PMID- 10786961
TI - The epidemiology of the systemic inflammatory response.
AB - OBJECTIVE: To examine the incidence, risk factors, aetiologies and outcome of the
various forms of the septic syndromes (the systemic inflammatory response
syndrome [SIRS] sepsis, severe sepsis, and septic shock) and their relationships
with infection. DESIGN: Review of published cohort studies examining the
epidemiology of the septic syndromes, with emphasis on intensive care unit (ICU)
patients. RESULTS: The prevalence of SIRS is very high, affecting one-third of
all in-hospital patients, and >50% of all ICU patients; in surgical ICU patients,
SIRS occurs in >80% patients. Trauma patients are at particularly high risk of
SIRS, and most these patients do not have infection documented. The prevalence of
infection and bacteraemia increases with the number of SIRS criteria met, and
with increasing severity of the septic syndromes. About one-third of patients
with SIRS have or evolve to sepsis. Sepsis may occur in approximately 25% of ICU
patients, and bacteraemic sepsis in 10%. In such patients, sepsis evolves to
severe sepsis in >50% of cases, whereas evolution to severe sepsis in non-ICU
patients is about 25%. Severe sepsis and septic shock occur in 2%-3% of ward
patients and 10%-15% or more ICU patients, depending on the case-mix; 25% of
patients with severe sepsis have shock. There is a graded severity from SIRS to
sepsis, severe sepsis and septic shock, with an associated 28-d mortality of
approximately 10%, 20%, 20%-40%, and 40%-60%, respectively. Mortality rates are
similar within each stage, whether infection is documented or not, and
microbiological characteristics of infection do not substantially influence
outcome, although the source of infection does. While about three of four deaths
occur during the first months after sepsis, the septic syndromes significantly
impact on long-term outcome, with an estimated 50% reduction of life expectancy
over the following five years. The major determinants of outcome, both short-term
and long-term, of patients with sepsis are the severity of underlying diseases
and comorbidities, the presence of shock and organ failures at onset of sepsis or
evolving thereafter. It has been estimated that two-thirds of the overall
mortality can be attributed to sepsis. CONCLUSIONS: The prevalence of sepsis in
ICU patients is very high, and most patients have clinically or microbiologically
documented infection, except in specific subset of patients. The prognosis of
septic syndromes is related to underlying diseases and the severity of the
inflammatory response and its sequelae, reflected in shock and organ
dysfunction/failures.
PMID- 10786963
TI - Monitoring and evaluating clinical trials data.
AB - This paper presents an overview of recent developments in statistical methods for
the design of clinical trials. Whilst the methods are suitable for application in
a wide range of therapeutic areas, they are of particular value in intensive care
medicine due to its high levels of mortality and short periods of follow-up. The
paper reviews the calculation of the sample size necessary to achieve a given
power requirement, and then describes the operation of a Data and Safety
Monitoring Board, the mid-trial reassessment of sample size and the use of
stopping rules to terminate a study as soon as sufficient evidence is available.
The purpose of the paper is to encourage investigators to consider the wide range
of design options which have recently become available, when planning a new
clinical study.
PMID- 10786964
TI - Genetic dissection of the molecular pathogenesis of severe infection.
AB - A fundamental question for the intensivist is why some individuals but not others
succumb to life-threatening infection. A growing body of evidence indicates that
both the risk of acquiring infection and the risk of developing severe
complications are determined by host genetic factors. These include a number of
single gene defects with devastating consequences, e. g. interferon-gamma
receptor mutations that lead to fatal infections with ubiquitous mycobacteria,
but such examples are relatively rare. Of greater importance for routine clinical
practice is the potentially vast number of genetic variants with subtle effects
on the regulation or function of specific immunological, physiological and
metabolic mediators. Such polygenic traits do not obey simple patterns of
familial segregation seen for monogenic disorders, and their clinical
investigation is further complicated by the environmental variability of
infectious exposure. Recent advances in this field have therefore largely stemmed
from hospital-based case-controlled studies that have uncovered disease
associations with specific DNA polymorphisms in candidate gene regions. For
example, tumour necrosis factor polymorphisms have been associated with
susceptibility to malaria and other infections; chemokine receptor polymorphisms
with susceptibility to HIV; natural resistance-associated macrophage protein 1
with tuberculosis; and mannose binding lectin polymorphisms with meningococcal
disease. A much greater number of genetic associations will emerge as the full
extent of human genomic diversity becomes known. The challenge for clinical
investigators is to generate an epidemiological framework for population- and
family-based association studies, which is sufficiently robust to exclude
population artifacts and sufficiently powerful to be able to dissect true disease
causing polymorphisms from linked genetic markers. In the long term this approach
promises to identify host mediators that are critical for pathogenesis and
immunity and to yield molecular insights into the complex processes of human gene
regulation. This information is likely to be of considerable value in designing
more effective approaches to the treatment and prevention of life-threatening
infectious disease.
PMID- 10786965
TI - Cytokine and cytokine receptor polymorphisms in infectious disease.
AB - Host immune responses strongly control the outcome of infectious disease, and the
resistance to bacterial infections in humans is in part genetically determined.
Responses to Gram-negative bacterial endotoxin are affected by the concentration
of plasma lipoproteins and lipid transport proteins that are genetically
controlled. Alterations of plasma lipid profiles by genetic manipulation in mice
indeed strongly modify resistance to bacterial infections. Recently, the TLR-4
receptor has been identified as the endotoxin receptor, and TLR-4 mutations are
the cause of endotoxin resistance in mice. It is probable that such defects also
exist in humans, although they must be rare. The capacity of monocytes to produce
TNFalpha varies more than tenfold, and several polymorphisms within the TNFalpha
gene have been associated with increased TNFalpha production and increased
mortality of sepsis. However, these associations most likely result from linkage
disequilibrium with other immune response genes on chromosome 6. Polymorphisms
within the IL-1beta and the IL-1RA genes (located on chromosome 2) are associated
with altered protein production rates, and certain haplotypes have been linked to
inflammatory disease (no studies in bacterial infectious disease have been
published). Mutations in the receptors for IL-12 and IFNgamma, both critical for
clearance of intracellular infectious pathogens, occur in consanguineous
populations and are associated with severe recurrent infections with Salmonella
species and mycobacteria. In conclusion, no human cytokine deficiency syndromes
are known, and it remains uncertain whether genetically determined differences in
the production rate of pro-inflammatory cytokines alter the outcome of sepsis. In
contrast, mutations in the IL-12 and IFNgamma receptor (and possibly the
endotoxin receptor) genes are associated with recurrent bacterial infections,
whereas TNFR1 mutations cause fever of unknown origin.
PMID- 10786966
TI - Neutropenia: clinical implications and modulation.
PMID- 10786967
TI - Leukocytes: friend or foe.
AB - Leukocytes have a fundamental role in innate and adaptive immunity, wound
healing, tumour surveillance and in tissue remodelling. It is their function in
the inflammatory response however that is of most interest to us in the intensive
care setting. Over the last three decades we have gained significant insights
into leukocyte activation, recruitment and mediator secretion and the
contribution of these agents to both the onset and resolution of sepsis and
inflammation. The body relies on the inflammatory response for protection.
Leukocytes occupy a pivotal position in this but to maintain these cells in a
state of permanent activation would be unsustainable, with widespread
microvascular plugging, uncontrolled free radical release and an excessive
metabolic demand. Leukocytes thus circulate in a quiescent state and are rapidly
activated by invading pathogens and other stimuli. A direct consequence of this
protective strategy is that the inflammatory response may be inadequate, with the
risk of overwhelming sepsis, or excessive, leading to rampant systemic
inflammation and consequent multiple organ damage. It is now becoming apparent
however that in addition to leukocytes other cells have important roles both in
defence against invading pathogens and in driving malignant inflammation. This
review will focus on two new facets of the innate immune system, the Toll family
of proteins as the signal transduction element for endotoxin, and the
antimicrobial peptides. These exemplify potential damaging and protective
response elements but importantly neither are restricted to leukocytes. The
capacity of cells and tissues other than the leukocytes to participate and even
lead in the inflammatory responses will also be explored.
PMID- 10786968
TI - Gene therapy for acute lung injury.
AB - The remarkable transition of biological science into the age of molecular biology
held great promise for development of new therapies for treatment of human
disease. The fact that the technology exists for analyzing genetic material in
exquisite detail and constructing DNA in virtually any desired form was the basis
for promising rapid translation into clinical medicine and the final cure for
genetically determined diseases; cystic fibrosis is the prime example of such a
lung disease. The promise was not kept, at least not in a time frame which was
expected. That result is neither because the rationale was faulty nor because the
tools of molecular biology were wanting. The devil was and is in the details. How
do you deliver DNA to the desired cell targets in amounts sufficient to
accomplish the desired effect? Viral vectors have received the most attention,
but viral vectors have proven to have both theoretical and practical problems. In
the lungs, these vectors have not fulfilled their original promise. Non-viral
based strategies work in a general sense, but efficiency of gene delivery in vivo
has been a limitation. In addition, the experimental end points in both clinical
and preclinical investigation have been most often designed to demonstrate
phenomenology rather than potential efficacy. And, why limit the potential of
gene therapy to inherited disease? In fact, treatment of acquired diseases by
increasing or decreasing expression of a given gene in the lungs that would
hasten recovery from an acquired disease might be easier than treating inherited
disease because the requirements for duration of transgene expression would be
less stringent. Over the past two decades, we have learned enough about the
pathogenesis of acute lung injury to predict that increased (or decreased)
production of certain biologically active mediators should be beneficial. Genes
encoding some of these mediators have been cloned and constructs made which
express the genes. It is now possible using either viral or non-viral strategies
to deliver expression constructs to the lungs and, since acute lung injury has a
dismal prognosis and no effective drugs have been identified, this seems a good
clinical target for gene therapy. In preclinical studies, we have shown that
increased expression of the gene encoding the constitutive form of the
cyclooxygenase gene (COX-1) results in increased production of prostacyclin and
PGE2 by the lungs and inhibits endotoxin induced pulmonary hypertension and
edema. Additional studies demonstrate that increased expression of the alpha-1
antitrypsin gene in human respiratory epithelium in culture and in vivo has anti
viral and anti-inflammatory effects that are not predicted by extracellular
concentrations of the transgene product. Thus, acute lung injury is a reasonable
target for gene therapy, and evidence to date indicates that current technology
is sufficiently robust to pursue this novel area for treatment of this
devastating disease.
PMID- 10786969
TI - Immunomodulatory therapies in sepsis.
AB - Despite advances in critical care medicine, mortality from sepsis in ICU patients
remains high. In response to several infectious and non-infectious stimuli,
monocytes/ macrophages release a number of mediators, including cytokines,
involved in the proinflammatory response that underlies sepsis. The excessive
release of these mediators results in the development of whole body inflammation,
and plays an important role in the pathogenesis of sepsis and septic shock. In
addition, patients with sepsis also undergo an anti-inflammatory phase (the
compensatory anti-inflammatory response syndrome) and at times, a mixed response
with both pro-and anti-inflammatory components (the mixed antagonistic response
syndrome). The initial systemic hyperinflammation is caused by production of
inflammatory cytokines, especially tumour necrosis factor-a (TNF-alpha), and also
interleukin-1 (IL-1), IL-6, and interferon gamma, which act synergistically with
TNF-alpha in inducing shock in animal models. However, clinical trials aimed at
downregulating these mediators using antibodies against endotoxin, TNF-alpha,
antagonists of IL-1 or platelet activating factor have proved to be uniformly
disappointing. Not only have these agents been found to have no effect, but they
may also increase mortality. One of the reasons for such failure may be the lack
of precise immunological monitoring during the course of sepsis. We have recently
demonstrated that sepsis shows a biphasic immunological pattern during the
initial and later phase: the early hyperinflammatory phase is counterbalanced by
an anti-inflammatory response which may lead to a hypoinflammatory state. The
latter is associated with immunodeficiency that is characterised by monocytic
deactivation, so-called immunoparalysis. Interferon gamma-1 b has an
immunoregulatory effect in patients with immunoparalysis during the compensatory
anti-inflammatory response syndrome, not only restoring levels of HLA-DR
expression but also reestablishing the ability of monocytes to secrete cytokines
such as TNF-alpha. By monitoring immune status in septic patients, targeted
intervention may lead to more success in immunomodulation of sepsis.
PMID- 10786971
TI - Cardiac reserve: linking physiology and genetics.
PMID- 10786970
TI - Endotoxin immunization.
PMID- 10786973
TI - Regulation of bacterial translocation by nitric oxide.
AB - Nitric oxide (NO) appears to play a paradoxical role in intestinal physiology.
Although NO has potent bactericidal effects, a growing body of evidence suggests
that it mediates intestinal injury and breakdown of gut barrier function. Data
from our lab and others show an increased incidence of bacterial translocation
following endotoxin challenge, and upregulation of inducible NO synthase (iNOS)
mRNA and protein in the intestine. These phenomena co-localize with enterocyte
apoptosis at the tips of the intestinal villi and immunoreactivity to
nitrotyrosine. Electron microscopy reveals swollen mitochondria, implicating
these organelles as putative targets for NO or its reactive nitrogen
intermediates. We review some of the literature and discuss our current work in
trying to define this mechanism.
PMID- 10786972
TI - "Gut-feeling" or evidence-based approaches in the evaluation and treatment of
human short-bowel syndrome.
AB - Short bowel syndrome is the malabsorptive state that often follows extensive
resection of the small intestine. Long-term survival without parenteral nutrition
depends on the process of intestinal adaptation, through which the remaining
small bowel gradually increases its absorptive capacity. The process of
intestinal adaptation is almost exclusively luminal nutrient dependent. To date
the clinical management of short bowel patients is mostly based on a 'trial and
error' regimen because human data and randomised trials using trophic substances
are lacking due to the small number of patients annually present in pediatric
surgical centres. We evaluate here the currently available as well as some more
recently developed methods of measuring intestinal absorption and adaptation in
short bowel patients. New techniques such as measurements of (1) intestinal
permeability and carbohydrate absorption using the sugar absorption test, (2)
gastrointestinal hormone production of gastrin, cholecystokinin and peptide YY,
(3) transmural potential difference of the gastrointestinal tract using
electrophysiology and (4) mucosal enzyme expression of lactase and sucrase
isomaltase using immunohistochemistry were evaluated. These new techniques are
promising in monitoring the process of adaptation of the remaining intestine and
evaluating the effect of therapeutic interventions in patients with short bowel
syndrome.
PMID- 10786974
TI - The effects of intravenous epidermal growth factor on bacterial translocation and
central venous catheter infection in the rat total parenteral nutrition model.
AB - Sepsis is a major complication of total parenteral nutrition (TPN) in children.
Gut mucosal atrophy (GMA) and bacterial translocation (BT) occur in patients
receiving TPN, and the translocated enteric organisms may cause central venous
catheter (CVC) infection. Epidermal growth factor (EGF) has a trophic effect on
the gut mucosa and may reduce BT, thereby reducing catheter infection. Using a
rat TPN model, the relationship between GMA, BT, and catheter sepsis was examined
and the effect on these of intravenous EGF was studied. There were four
experimental groups. Group 1 had no CVC, Groups 2, 3, and 4 had a continuous
central venous infusion as follows: group 2, saline; group 3, TPN; group 4, TPN
with EGF. Groups 1 and 2 had free access to chow, groups 3 and 4 had no enteral
feeds. After killing at 1 week, blood, tissue, and catheter specimens were
cultured and mucosal morphology analysed. BT was defined as the presence of the
same organism in cultures from the gut lumen and mesenteric lymph nodes (MLN).
TPN only (group 3) resulted in GMA and BT, and 5 of 12 animals with BT had the
same gut bacteria in blood and/or catheter cultures. The addition of EGF to the
TPN significantly reduced GMA, BT to the MLN, and blood and/or catheter
infections (P = <0.05). In animals carrying enterococci, there was a significant
reduction in translocation of enterococci (group 3: 8/14; group 4: 0/11; P<0.05)
and catheter infection by enterococci was prevented (group 3: 3/14; group 4:
0/11). EGF thus reduced GMA, BT, and blood and/or catheter infection when given
IV to rats receiving TPN. Enterococcal translocation and subsequent blood and/or
catheter infection was completely prevented, suggesting a selective effect of
EGF.
PMID- 10786975
TI - Growth-factor enhancement of compromised gut function following massive small
bowel resection.
AB - Our laboratory has shown that epidermal growth factor (EGF) and hepatocyte growth
factor (HGF) can improve the function of normal rat small intestine. This study
was designed to evaluate the role of these growth factors on the residual small
intestine following massive (80%) small bowel resection. Our data demonstrate
that EGF and HGF can enhance intestinal substrate absorption and mucosal mass
beyond that which occurs with intestinal adaptation. These growth factors may be
beneficial in the management of children with short bowel syndrome.
PMID- 10786976
TI - Maternal cocaine abuse resulting in necrotizing enterocolitis. An experimental
study in a rat model. II. Results of perfusion studies.
AB - During the last decade, several publications have appeared associating the
maternal use of cocaine and subsequent development of necrotizing enterocolitis
(NEC). In 1994, the effects of cocaine in pregnant rats had been reported by this
group: a significant decrease in the number of live births, mean birth weight and
mean placental weight. In addition, histopathologic examinations revealed severe
inflammation and degenerative vascular changes in the uterus and placenta. Severe
histopathologic changes resembling NEC such as focal necrosis, necrobiosis, and
hemorrhagic inflammatory changes in the gastrointestinal tract of the embryos
were also reported. The aim of the second part of this study was to assess the
hemodynamic effects of cocaine HCI in pregnant rats and the results of perfusion
studies in the uterus, placenta, and fetuses to determine a relation between the
dose of drug, hemodynamic changes, and degree of histopathologic findings. Forty
seven Wistar albino rats and 91 rat fetuses were studied: group A (pregnant
rats), 16 rats and 91 rat fetuses, group B (nonpregnant rats), 31 rats. Each
group was divided into subgroups of cocaine-abused and non-cocaine-abused rats.
In each group 2-3 mCi technetium Tc-99m methoxyisobutyl-isonitryl (Sesta MIBI)
was injected into the tail vein. Radioactivity counts per g tissue (cps/g) in the
uterus, placenta, and fetus were assessed by gamma counter. Cocaine 75 mg/kg per
day severely decreased the perfusion of the uterus, placenta, and fetuses. These
impairments were statistically significant. In lower doses (30-50 mg/kg per day)
no statistically significant changes were observed in the perfusion of the uterus
and placenta, but a significant decrease in fetal perfusion was seen. In group B,
no significant changes in the perfusion of the uterus due to cocaine were seen.
Thus, maternal cocaine abuse results in a reduction in perfusion of the uterus,
placenta, and fetus. There was a dose-dependent correlation between the perfusion
changes and the development of NEC-like histopathologic changes: the higher the
cocaine dose received by the mother, the higher the level of placental and fetal
injury. We suggest that perinatal cocaine exposure should be considered a high
risk for development of NEC in rat fetuses and embryos. For this reason, infants
with a history of possible maternal cocaine abuse or positive urinary cocaine
metabolites have to be followed very carefully for NEC.
PMID- 10786977
TI - Fiberoptic bronchoscopy in children using the laryngeal mask airway.
AB - We describe our experience using the laryngeal mask airway (LMA) in children to
facilitate diagnostic procedures in fiberoptic bronchoscopy (FOB). Two cases of
stridor, two cases of protracted pneumonia, and one case of laryngotracheomalacia
were studied. Intravenous atropine (0.02 mg/kg) was given, and induction was
carried out by either inhalation of a mixture of halothane-nitrous oxide-oxygen
(n = 3) or IV injection of propofol (n = 2). After an adequate depth of
anesthesia was obtained, a LMA was introduced. A 2.7-mm-OD flexible fiberoptic
bronchoscope was introduced through the LMA and the diagnostic procedure was
performed. Ventilation and oxygenation were maintained, and no serious morbidity
was associated with the procedure. We found the use of the LMA to facilitate FOB
to be useful, easy to perform, and safe, avoiding nasal trauma and providing a
patent airway.
PMID- 10786978
TI - Peritonitis in childhood: aspects of pathogenesis and therapy.
AB - The pathogenesis of peritonitis due to hollow-viscus perforation is currently
accepted as being mainly based on the local and systemic release of pro- and anti
inflammatory mediators triggered by the presence of bacteria and bacterial
products in the abdominal cavity. Therefore, treatment consists in focal
restoration, intraoperative debridement and lavage, and postoperative measures
such as drainage, continuous peritoneal lavage, or scheduled reoperation aiming
at the removal of infectious agents from the peritoneal cavity to prevent
persisting peritonitis and sepsis. In order to evaluate the pathophysiologic
relevance of the bacterial and endotoxin load of the peritoneal exudate, we
examined the peritoneal fluid of 20 children with perforated appendicitis for
qualitative and quantitative analysis of bacteria, antibiotic concentrations, and
endotoxin content. The time period ranged in 12-h intervals from intraoperatively
to day 5. Eighteen of 20 fluid specimens (90%) showed endotoxin levels above 1.5
endotoxin units EU/ml (standard <0.1 EU/ml). The most common bacterial species
isolated was Escherichia coli, mostly in high concentrations. Despite persisting
high endotoxin concentrations and bacterial loads in the peritoneal cavity during
the 5 postoperative days, the children recovered uneventfully and the systemic
signs of infection disappeared rapidly. In conclusion, neither the bacterial nor
the endotoxin load of the peritoneal cavity proved to be associated with the
clinical course. Therefore, we hypothesize that during peritonitis
compartmentalization of the focus of infection prevents further systemic
reactions and ultimately leads to removal of the infectious agents by endogenous
mechanisms. At least in peritonitis due to perforated appendicitis in children,
adjuvant surgical measures in addition to appendectomy and intraoperative
debridement are not necessary.
PMID- 10786980
TI - Factors responsible for successful primary closure in bladder exstrophy.
AB - To assess the important factors for successful primary closure in staged
reconstruction of bladder exstrophy, 25 patients (18 males, 7 females) underwent
primary bladder closure during the years 1993-1997. Twenty-one were more than 72
h old; all of these underwent bilateral posterior iliac osteotomies followed by
primary bladder closure during the same anesthetic. Bladder closure was done in a
double layer. The ureteric catheters were removed after 2 weeks and the bladder
catheter after 3.5-4 weeks. Only 1 patient had a bladder dehiscence on the 10th
postoperative day due to infection; 3 had partial wound dehiscences but no
bladder dehiscence. One had a partial bladder prolapse. The osteotomies needed no
drainage, and no complications occurred. One patient needed a urinary diversion 3
years after surgery as the bladder capacity did not increase. Eleven important
factors play a pivotal role for successful primary bladder closure: (1) Proper
patient selection; (2) A staged approach; (3) Anterior approximation of the pubic
bones with placement of the bladder and urethra in the true pelvis; (4) Posterior
bilateral iliac osteotomies in all indicated cases; (5) Double-layered closure of
the bladder; (6) Two weeks' proper ureteric catheter drainage; (7) Prevention of
infection; (8) Prolonged and proper postoperative immobilization; (9) Prompt
treatment of bladder prolapse; (10) Prevention of abdominal distension
postoperatively; and (11) Ruling out bladder-outlet obstruction before removing
the bladder catheter.
PMID- 10786979
TI - Outcome analysis of pyeloplasty in infants.
AB - The study examined the outcome of pyeloplasties done for decompensated
ureteropelvic junction (UPJ) obstruction in infancy over a 13-year period. In a
retrospective study, 186 children who underwent pyeloplasty in infancy were
analysed with particular emphasis on the pre- and postoperative findings of 123I
hippuran scintigraphy/diuretic renograms. The pre- and postoperative management
is outlined in detail. The 186 patients underwent a total of 203 pyeloplasties
during the period from January 1983 to 31 December 1996. Three children died; one
required a nephrectomy. The postoperative scintigrapic results of 156 children
(85%) done about 12 months after surgery were available for evaluation: 101 (64%)
showed stable renal function and 43 (27%) revealed more than 5% improvement of
renal function. In 12 cases (7%) renal function deteriorated after pyeloplasty by
more than 5% compared to the preoperative scintigram. It is concluded that
pyeloplasty in infants is a low-risk procedure. The encouraging results of this
series support early correction of UPJ obstruction.
PMID- 10786981
TI - Surgical management of enlarged prostatic utricle.
AB - The prostatic utricle (PU), or prostatic pouch, is a rudimentary structure
present in the male prostatic urethra, and is derived from both the mullerian and
wolffian ducts. As the PU is of mixed origin, a patient with an enlarged utricle
should be carefully examined to ascertain whether it is associated with female
internal organs. The clinical presentation, diagnostic evaluation, and a new
surgical approach, posterior sagittal rectum retracting, are discussed. A plan
for management of PU with proximal hypospadias is suggested.
PMID- 10786982
TI - Antenatal identification of a cervical oesophageal duplication.
AB - Duplications of the alimentary tract can occur from mouth to anus, and often are
undetected until they present with complications. We report duplication of the
cervical oesophagus presenting as dyspnoea and stridor in a two year old. In
retrospect, this had been detected on ultrasound antenatally, but no specific
diagnosis had been made. We review the present literature to raise awareness of
duplication as one cause of cysts identified antenatally in this region.
PMID- 10786983
TI - Congenital pyloric atresia and junctional epidermolysis bullosa: a report of two
cases.
AB - The association between epidermolysis bullosa (EB) and congenital pyloric atresia
(CPA) is rare, but is known distinct clinical entity with autosomal recessive
inheritance. The outcome of such an association was universally fatal. This is a
report of two newborns with EB and CPA, associated with additional aplasia cutis
congenita in one case. One patient was treated postoperatively with phenytoin and
survived. Aspects of the diagnosis, pathogenesis, and management are also
discussed.
PMID- 10786984
TI - Extra-hepatic biliary-ductal necrosis in acute pancreatitis: a rare complication.
AB - An 8-year-old male presented with an acute abdomen. Exploration revealed bilious
ascites, oedematous pancreatitis with areas of necrosis, and omentum showing
patches of fat necrosis. The common bile duct and almost all of the common
hepatic duct were gangrenous and had sloughed, with bile leaking from the
junctional stump of the right and left hepatic ducts. The patient was managed
successfully by Roux-en-Y hepaticojejunostomy. This is a rare case showing
necrosis and sloughing of the extrahepatic bile ducts in acute pancreatitis.
PMID- 10786985
TI - Multiple gastrointestinal atresias with cystic dilatation of the biliary duct.
AB - A term newborn developed signs and symptoms of an upper-intestinal obstruction. A
palpable transverse upper-abdominal mass was identified. An ultrasound
examination demonstrated a cystic mass with massive dilatation of the biliary
tree. At laparotomy, dozens of segmental intestinal atresias (IA) from the
jejunum to the rectum were identified. The cystic mass was the duodenum,
obstructed distally from the atresias and proximally from an antral web. The
biliary dilatation was due to normal drainage into a closed-loop duodenal
obstruction, and was relieved by division of the web. The multiple atresias were
explored, but establishment of intestinal continuity was impossible. The entity
of multiple segmental IAs in association with cystic biliary dilation has been
previously described, but there are no recorded survivors; 35 patients have been
reported in the world literature. Our patient was the longest survivor; she
finally died after 2 years of gastrostomy-tube drainage and total parenteral
nutrition while awaiting intestinal transplantation. Only 5 patients other than
ours had documented immune-system abnormalities. We review the findings and
management of this rare syndrome.
PMID- 10786986
TI - An antenatally-diagnosed solitary, non-parasitic hepatic cyst with duodenal
obstruction.
AB - Congenital solitary, non-parasitic liver cysts are uncommon lesions that are
rarely diagnosed antenatally. The cystic nature of the antenatally-diagnosed
abdominal cyst in our case was confirmed postnatally by ultrasound. Partial
excision with marsupialisation and release of extrinsic bands on the second part
of the duodenum was done.
PMID- 10786987
TI - Macrodystrophia lipomatosa with associated fibrolipomatous hamartoma of the
median nerve.
AB - Macrodystrophia lipomatosa (MDL) is a rare disease typically causing localized
gigantism and is often associated with a fibrolipomatous hamartoma (FH) of the
median or plantar nerve. A previously unreported case of MDL with associated FH
of the median nerve is presented.
PMID- 10786988
TI - Abdominal expansion using a polytetrafluoroethylene prosthesis in the treatment
of Pepper syndrome.
AB - The authors report three cases of stage IV-S neuroblastoma in infants aged 4, 6,
and 8 weeks, who despite chemo- and radiotherapy required surgical intervention
to urgently relieve major thoracoabdominal compression secondary to massive
hepatomegaly. The results were successful, with abdominal expansion being
achieved by the introduction of a polytetrafluoroethylene prosthesis, which was
removed during the 2nd, 3rd and 7th postoperative month, respectively, after
tumor regression. Two children were in complete remission 32 and 38 months later,
the 3rd died after 16 months of tumor progression.
PMID- 10786989
TI - Renal salvage procedure for synchronous bilateral Wilms' tumor.
AB - This report describes a renal salvage procedure performed in a 2-year-old girl
with bilateral renal tumors comprising a multilocular, cystic tumor of the right
kidney and a solid and cystic nephroblastoma of the left kidney after
chemotherapy. Surgery was performed because the right kidney became
hydronephrotic due to compression by the enlarged cysts, while the left tumor
showed only minimal shrinkage even after three courses of chemotherapy. The right
sided cysts were simply unroofed and the left-sided tumor was extirpated by
partial nephrectomy. Her postoperative course was uneventful with considerable
recovery of the function of each kidney. This procedure should be considered if
the pathological features of the tumor are relatively favourable.
PMID- 10786991
TI - Preterm and particularly, pre-labour cesarean section to avoid complications of
gastroschisis.
PMID- 10786990
TI - Penoscrotal hypospadias and coarctation of the aorta with mixed gonadal
dysgenesis.
AB - A 45,X/46,Xidic(Y)(q11.2) mosaicism was found in a 4-year-old boy. The clinical
appearance was characterized by bilateral cryptorchidism, penoscrotal
hypospadias, short penis, and coarctation of the aorta. The latter is the only
abnormality also seen in Turner syndrome. A biopsy of the gonads revealed normal
prepubertal testicular tissue. A chromosome analysis in all boys with
penoscrotal, scrotal, or perineal hypospadias and a thorough examination of the
heart in children with 45,X/46,XY mosaicism are recommended.
PMID- 10786992
TI - 1999 pioneer in neurovirology: Richard T Johnson, MD.
PMID- 10786993
TI - Molecular circuitry regulating herpes simplex virus type 1 latency in neurons.
AB - Herpes simplex virus (HSV) type 1 (HSV-1) enters nerve endings during a primary
infection, is transported to sensory ganglia, and establishes latency within
nuclei of a subpopulation of neurons. The latent state is characterized by
absence of detectable HSV-1 antigen, minimal transcription of productive cycle
genes, and high expression of 1.5- and 2-kb viral transcripts, termed the major
latency-associated transcripts (LATs), within nuclei of a subpopulation of
infected neurons. Transcription within the HSV-1 LAT genomic locus has been
reported to both facilitate the establishment of latency in additional neurons
and to increase the frequency of spontaneous and induced viral reactivation in
animal model systems. More recent evidence suggests some possible mechanisms that
may explain the relationship between LATs and both reactivation and establishment
of latency. This review summarizes general aspects of latency, but focuses on the
structure, expression, and function of LATs, and the interaction between host
transcriptional regulators and viral gene expression that may impact latency and
reactivation. A model that incorporates evidence from a number of experimental
studies is proposed that summarizes the involvement of the LAT locus in the
biology of HSV-1 latency.
PMID- 10786994
TI - Herpes simplex replication and dissemination is not increased by corticosteroid
treatment in a rat model of focal Herpes encephalitis.
AB - Neurological damage in Herpes simplex type 1 encephalitis results from neuronal
cell death secondary to viral invasion, and from inflammatory changes and
cerebral oedema secondary to the immune response to the virus. Corticosteroids
could have an important role in the management of Herpes simplex encephalitis
because their anti-inflammatory action reduces cerebral oedema. However their use
has been limited by concerns that their immunosuppressive actions could increase
viral replication and spread. The present study examined this issue in a rat
model in which injection of HSV-1 into the cervical vagus nerve produced a well
defined focal encephalitis, characterised by an orderly progression of the virus
through central neural pathways connected with vagal afferent termination sites
in the medulla oblongata. After injection of HSV-1, rats were treated twice a
day, either with vehicle (saline, 400 microl i.p.), with acyclovir (30 mg/kg
i.p.), with dexamethasone (5 mg/kg i.p.), or with both acyclovir and
dexamethasone. Animals were sacrificed after 72 h, and viral load in different
brain regions was quantified by computer-assisted measurement of the area
occupied by immunohistochemical reaction product. Treatment with acyclovir
reduced viral load to 17 +/- 5% of the saline value (P < 0.01). After
dexamethasone treatment, the viral load (63 +/- 13% of the saline value) was also
reduced (P < 0.05). Treatment with both acyclovir and dexamethasone reduced viral
load to 26 +/- 8% of the saline value (P < 0.01 compared with saline, and P >
0.05 compared to acyclovir alone). Our results confirm the effectiveness of
acyclovir in a new model of HSV-1 infection, and provide evidence that
corticosteroids do not inhibit the antiviral action of acyclovir. In addition
corticosteroids may decrease the extent of infection in their own right. The
acute time course studied in our model parallels the time course of acute Herpes
simplex encephalitis in humans. Our data suggests that corticosteroids are not
detrimental when combined with acyclovir in the management of this condition.
PMID- 10786995
TI - A multi-mutant herpes simplex virus vector has minimal cytotoxic effects on the
distribution of filamentous actin, alpha-actinin 2 and a glutamate receptor in
differentiated PC12 cells.
AB - To develop effective gene therapy techniques that target populations of neurons
in the spinal cord, suitable vectors must be developed that will undergo
efficient, retrograde transport from an appropriate peripheral site and will not
be cytotoxic. Our previous work (LeVatte et al, 1998a) has demonstrated that a
replication defective herpes simplex virus vector 14Hdelta3vhsZ, that has been
substantially detoxified, is retrogradely transported from peripheral sites and
can infect large numbers of the targeted spinal neurons. We plan to develop
targeted gene therapy approaches designed to modulate the excitatory
glutamatergic methyl-D-aspartate (NMDA) receptor in spinal cord neurons as a
means of ameliorating a form of episodic high blood pressure that occurs after
spinal cord injury. In this report, we demonstrate that, in differentiated PC12
cells, a neuronal-like cell line, the virus vector does not appear to alter
aspects of the cytoskeletal architecture important to the proper distribution of
the NMDA receptor. In turn, the distribution of endogenous NMDA receptor 1
subunit protein (NMDAR1) or a transfected NMDAR1-green fluorescent fusion protein
was also found to be unaltered after vector infection. However, whereas
endogenous NMDAR1 distribution was maintained, vector infection did tend to
reduce the level of its expression. This drop in endogenous NMDAR1 expression
coincided with the expression of the HSV immediate early genes ICP0 and ICP27
over the first 24-48 h. These results indicate that the 14Hdelta3vhsZ herpes
simplex virus vector is suitable to use in future strategies to alter the level
of gene expression in targeted populations of spinal cord neurons.
PMID- 10786996
TI - Etiology of microglial nodules in brains of patients with acquired
immunodeficiency syndrome.
AB - Microglial nodules associated with opportunistic and HIV-related lesions are
frequently found in the brains of AIDS patients. However, in many cases, the
causative agent is only presumptively suspected. We reviewed 199 brains of AIDS
patients with micronodular lesions to clarify their etiology by
immunohistochemistry (to Toxoplasma gondii, cytomegalovirus, herpes simplex virus
I/II, varicella zoster virus and HIV-p24 core protein), PCR (for herpetic viruses
and Mycobacterium tuberculosis) and electron microscopy. Productive HIV infection
was observed in 110 cases (55.1%): 30 cases with Toxoplasma gondii encephalitis,
30 with cytomegalovirus encephalitis, eight with multiple cerebral diseases,
while in the remaining 42 cases HIV was the only pathogenetic agent.
Multinucleated giant cells (hallmark of HIV infection) were found in the MGNs of
85/110 cases with HIV-related lesions; the remaining 25 cases had only p24
positive cells but no multinucleated giant cells. In these latter cases the
micronodular lesions had been initially attributed to the main opportunistic
agent found in the brain, or defined as subacute encephalitis. Individual
microglial nodules positive for an opportunistic pathogen were generally negative
for HIV antigens. In 13 cases no opportunistic agent or HIV productive infection
was found. In these cases, PCR and electron microscopy examination for HIV and
other viral infections were negative. Our data suggest that HIV
immunohistochemistry should be used for the etiological diagnosis of micronodular
lesions in AIDS brains, even in the presence of other pathogens. After extensive
search, the etiology of the microglial nodules remains unknown in only a small
percentage of cases.
PMID- 10786997
TI - Expression of complement inhibitor protein CD59 in human neuronal and glial cell
lines treated with HIV-1 gp41 peptides.
AB - In attempts to elucidate the pathogenic mechanisms involved in neurodegeneration
in AIDS patients with cognitive deficits, the possible effect of HIV-1
transmembrane envelope protein gp41 on expression of the membrane inhibitor of
complement mediated cytolysis (CD59) was assessed in human neuronal (SK-N-SH) and
astroglial (T98G) cell lines. Western blotting analyses demonstrated that an
immunodominant (ID, aa 598-613) gp41 peptide as well as the recombinant gp41
protein encompassing this domain markedly reduced CD59 level in a dose dependent
manner whereas p24 and control peptide had little effect. RT-PCR showed that ID
peptide also elicited a reduction in the expressed CD59 mRNA level. This gp41
peptide apparently down-regulated phorbol 12,13-dibutyrate induced elevation of
CD59 at the protein and mRNA levels in a manner similar to that conferred by
protein kinase C inhibitor, H-7 or staurosporine in SK-N-SH. Interestingly,
proinflammatory cytokines such as IL-1beta or IFN-gamma as well as LPS greatly
decreased CD59 in SK-N-SH and to a lesser extent in T98G whereas TNF-alpha did
not significantly alter it. In contrast, antioxidants and anti-inflammatory
agents enhanced CD59 expression reversing gp41 peptide mediated inhibitory effect
in SK-N-SH. Our data suggest that high level of gp41 or its metabolites as well
as impaired protein kinase response, chronic inflammation or antioxidant
depletion within HIV-1 infected brains may be associated with a diminished
expression of CD59 which would render neuronal cells to susceptible to indirect
bystander lysis in the presence of autologous complement.
PMID- 10786998
TI - High sensitivity detection of JC-virus DNA in postmortem brain tissue by in situ
PCR.
AB - Opportunistic infection of the central nervous system by human polyomavirus JC
can cause a devastating disease, progressive multifocal leukoencephalopathy
(PML). To gain new neuropathological insights into JC-virus (JCV) infection
patterns in PML at the light microscopic level, the highly sensitive indirect in
situ polymerase chain reaction (in situ PCR) was employed in up to 15-year old
formalin-fixed and paraffin-embedded postmortem brain tissue derived from nine
AIDS patients with PML. In situ PCR, in which target DNA is amplified
intracellularly and detected by a specific labelled probe in morphologically
intact tissue, was compared with conventional in situ hybridization (ISH).
Validity was ensured by the inclusion of 13 controls. JCV detection with in situ
PCR proved to be highly sensitive since in all nine brain samples the number of
positive cells exceeded the ISH results by 2-3-fold. Whereas by routine staining
the brain tissue of each individual patient showed regions with severe, mild or
no involvement by PML, improved detection of JCV DNA by in situ PCR allowed a
regrading into five different degrees of JCV infection. Significant myelin
staining was observed, suggesting that cell-to-cell contact may not be the only
means of virus spread but that new cells could also be infected by virus released
after cell lysis. Furthermore, using in situ PCR hitherto unreported
intracellular distribution patterns of JCV DNA in oligodendro- and astrocytes
were observed by light microscopy.
PMID- 10786999
TI - Upregulated expression of interleukin-8, RANTES and chemokine receptors in human
astrocytic cells infected with HIV-1.
AB - Human immunodeficiency virus (HIV) infection of the central nervous system (CNS)
affects primarily microglial cells and astrocytes. Infection of these latter
cells occurs independently of CD4 and is characterised by preferential
accumulation of 2 Kb mRNA, encoding mostly Nef, and by low levels of 4.5 and 9 Kb
RNAs. We have investigated the potential role of chronic HIV infection of human
astrocytic cells on the expression of pro-inflammatory cytokines, chemokines and
their receptors by comparing the infected TH4-7-5 with its parental uninfected
85HG66 cell lines. Upregulated levels of tumour necrosis factor-alpha (TNF-alpha)
and of certain chemokines, namely interleukin-8 (IL-8) and regulated upon
activation normal T cell expressed and secreted (RANTES), were observed in the
infected versus uninfected cells, whereas monocyte chemotactic protein-1 (MCP-1)
was comparably expressed in both cell lines. This pattern of expression was
confirmed in primary foetal astrocytes transiently transfected with HIV. In
addition, CXCR1, CXCR2 and CCR2b, receptors for IL-8 and MCP-1, respectively,
were also found to be upregulated in TH4-7-5 versus 85HG66. CXCR4, the receptor
of stromal cell derived factor-1 (SDF-1) and co-receptor for syncytium inducing
HIVs, was comparably expressed in infected and uninfected astrocytic cells,
whereas CCR5 was not detected in either cell line. Furthermore, treatment of TH4
7-5 cells with TNF-alpha or IL-1beta stimulated RNA and protein secretion of IL
8, MCP-1, and RANTES as well as HIV expression. Thus, our findings suggest that
HIV infection of astrocytic cells can contribute to the establishment of a
chronic inflammatory state in the CNS, eventually resulting in HIV encephalitis,
by increasing the secretion of pro-inflammatory cytokines, such as TNF-alpha and
several chemokines. Overexpression of chemokine receptors including CCR2b, CXCR1
and CXCR2 in infected astrocytic cells may contribute to HIV-induced damage of
the CNS via autocrine/paracrine activation of astrocytes.
PMID- 10787000
TI - Improvement in HIV-associated motor slowing after antiretroviral therapy
including protease inhibitors.
AB - A study of neuropsychological performance was conducted in 33 HIV+ patients
initiating highly active antiretroviral therapy (HAART). Grooved Pegboard (GP)
non-dominant hand performance improved in 23/33 (70%) subjects (P=0.002). Among
23 patients with motor slowing (GP non-dominant hand z score < -1.0) at baseline,
18 (78%) improved on the GP non-dominant hand test after initiating HAART
(P=0.001). GP non-dominant hand performance improved longitudinally in HIV+
patients initiating HAART, while matched HIV+ controls not on HAART did not
change (P=0.045). Significant improvement in motor performance can occur after
HAART in HIV+ patients with impairment.
PMID- 10787002
TI - Is there a role for quinacrine (Atabrine) in the new millennium?
PMID- 10787001
TI - Analysis of the Fv1 alleles involved in the susceptibility of mice to lactate
dehydrogenase-elevating virus-induced polioencephalomyelitis.
AB - Development of polioencephalomyelitis in mice infected with lactate dehydrogenase
elevating virus (LDV) requires expression of N-tropic ecotropic MuLV
retroviruses. 129/Sv mice are resistant to N-tropic MuLV expression and therefore
do not develop LDV-induced polioencephalomyelitis. The Fv1 gene determines the
susceptibility to retrovirus replication. We sequenced the open reading frame of
the Fv1nr allele of 129/Sv mice. It differs by only one nucleotide, modifying one
amino acid in the encoded protein, from the Fv1n allele of susceptible AKR and
C58 animals. We excluded that the resistance of 129/Sv mice to LDV-induced
polioencephalomyelitis resulted from the absence of endogenous N-tropic
retrovirus, by infecting (129/Sv x C58/J) F1 animals. Therefore it is possible
that the amino acid that defines the Fv1nr allele is responsible for resistance
of 129/Sv mice to N-tropic MuLV expression and to LDV-induced
polioencephalomyelitis.
PMID- 10787003
TI - Mixed cryoglobulinemia: new concepts.
AB - The most documented extrahepatic manifestation of hepatitis C virus (HCV)
infection is mixed cryoglobulinemia (MC). MC is characterised by the presence of
temperature-sensitive protein complexes: in type II MC, cryoglobulins are
composed of a monoclonal rheumatoid factor (usually, IgMkappa) against polyclonal
IgG. In type III MC, all components are polyclonal. The presence of
microheterogeneity and other new types of cryoglobulins is a novel and recent
observation. The production of different autoantibodies and circulating immune
complexes, including the cryoglobulins, are responsible for systemic vasculitis
and various organ damage. In a limited number of MC patients, a malignancy, that
is B-cell non-Hodgkin's lymphoma or hepatocellular carcinoma, may also develop.
Finally, results of interferon and/or ribavirin treatments in MC patients
represent an indirect proof for the pathogenetic link between MC and HVC
infection. The discovery of the relation between HCV infection and MC shows the
striking association between a viral infection and an autoimmune disease and,
thus, a potential link between the systemic autoimmune and lymphoproliferative
disorders.
PMID- 10787004
TI - The benefit of combining hydroxychloroquine with quinacrine in the treatment of
SLE patients.
AB - BACKGROUND: Although the benefit of antimalarials in the treatment of cutaneous
LE is well established, the effect of combined hydroxychloroquine and quinacrine
treatment in systemic lupus erythematosus with major organ involvement remains
underappreciated. PATIENTS: Six active SLE patients (SLEDAI score > 5 points),
with a mean duration of illness 9.1 yr (range 2-17 yr) were started on quinacrine
(100 mg/d) following failure to achieve clinical remission on a therapeutic
regimen which included a maintenance dose of hydroxychloroquine (400 mg/d)
together with prednisone (either 10-20 mg/d or higher daily doses of this agent
for short periods) and azathioprine (150 mg/d) or methotrexate (7.5 mg/week).
OUTCOME: In 5/6 of the patients the addition of quinacrine to the previous
treatment resulted in complete remission (SLEDAI 0-2 points), which persisted
over the follow-up period [mean +/- 2.2 yr (range 0.5-3.5)]. During this period
hydroxychloroquine and azathioprine were reduced to 200 mg/d and 100 mg/d
respectively, whereas prednisone was modified as follows: in 2 patients daily
administration was discontinued; in one the dose was reduced to 2.5 mg/d (from
that of > or = 20 mg/d); in 2 others the previous need for an intermittent course
was avoided. However, in one out of the six patients the addition for 3 months of
quinacrine to the therapeutic protocol did not result in clinical improvement and
was therefore discontinued. CONCLUSIONS: The promising results of this
preliminary investigation encourages the combined use of the two antimalarial
drugs in appropriate candidates. This modality may induce remission, seems to be
safe and possesses a steroid sparing effect.
PMID- 10787005
TI - The clinical features and prognosis of lupus with disease onset at age 65 and
older.
AB - Systemic lupus erythematosus (SLE) in the elderly is uncommon and rarely reported
with disease onset at age 65 and older. The aim of this study is to
retrospectively analyze the influence of age at disease onset on the clinical
features and prognosis of SLE. From 1988 to 1998, we encountered 21 lupus
patients with disease onset at age 65 and older (all are included in group A).
For comparison, 21 lupus patients with disease onset between 50-64 years of age
(group B) and 152 lupus patients with disease onset before 50 years of age (group
C) were obtained by a simple random sampling method from the hospital registry.
Clinical features as included in the 1982 ARA revised criteria for classification
of SLE and survival rate were analyzed and compared among these three groups.
Group A had a smaller female to male ratio, longer duration from disease onset to
diagnosis, less malar rash, more discoid lupus, and shorter survival rate that
group C. There was no statistically significant difference in clinical features
and survival between groups A and B, as well as between female and male patients
of these two groups. The main cause of death in group A was septic shock. In
conclusion, the clinical features and prognosis of SLE were influenced by the age
at disease onset. However, clinical features and prognosis of SLE were similar in
both late-onset lupus groups.
PMID- 10787006
TI - Systemic lupus erythematosus in three ethnic groups. VI: Factors associated with
fatigue within 5 years of criteria diagnosis. LUMINA Study Group. LUpus in
MInority populations: NAture vs Nurture.
AB - OBJECTIVE: To determine the frequency, degree and associated features of fatigue
among Hispanic (H), African American (AA) and Caucasian (C) patients with recent
onset (< or = 5 yr) systemic lupus erythematosus (SLE) at their baseline
evaluation. METHODS: H (n = 69), AA (n = 83) and C (n = 71) patients from the
LUMINA (LUpus in MInority populations: NAture vs Nurture) cohort were studied.
Fatigue [Fatigue Severity Scale (FSS)] was defined as present if FSS score > or =
3.0. Variables from functional, clinical, sociodemographic, health behaviors,
behavioral and psychological and immunogenetics domains were ascertained at study
entry. Associations were examined using regression models. RESULTS: Eighty-six
percent (85.7%) of patients reported having fatigue (82.6% H; 85.5% AA; 88.7% C);
median FSS score, 5.3. Factors from the psychological and clinical domains were
primarily associated with FSS; immunogenetic (HLA Class II phenotypes) features
were not. Increased fatigue was strongly associated with decreasing function,
both physical and mental. Variables associated with significantly greater degree
of fatigue at baseline in the multivariable stepwise model in order of decreasing
additional partial R2 explained included: abnormal illness-related behaviors,
older age, higher self-reported pain, greater degree of helplessness, greater
disease activity, Caucasian race, and lacking health insurance (model R2 = 37%).
CONCLUSIONS: Fatigue is one of the most prevalent clinical manifestations of SLE
across all ethnic groups. The perception of fatigue severity in SLE may be
multifactorial in origin, including psychosocial factors and disease activity. If
these prove causal, knowledge of their contribution may suggest therapeutic
and/or behavioral interventions, which could ameliorate this pervasive and often
incapacitating symptom of SLE.
PMID- 10787007
TI - Clinical outcome and predictors of disease evolution in patients with incomplete
lupus erythematosus.
AB - To determine the outcome and identify risk factors for evolution into systemic
lupus erythematosus (SLE) in a population of incomplete lupus erythematosus (ILE)
patients, we studied the clinical and serologic manifestations in a cohort of 87
ILE patients. ILE patients had at least one but less than four of the American
College of Rheumatology (ACR) classification criteria of SLE and did not present
distinctive clinical features or meet classification criteria of other connective
tissue diseases. The patients that remained with ILE were compared with patients
that evolved into SLE and with a cohort of 94 SLE patients. The mean disease
duration and follow up of ILE patients were 4.4 +/- 4.1 and 2.2 +/- 2.4 years
respectively. Eight patients evolved into SLE, but none presented major organ
damage. At baseline, patients that remained with ILE were less likely to have
photosensitivity, elevated anti-dsDNA and decreased C3 complement than patients
that evolved into SLE. At the end of the study, malar rash and oral ulcerations
were also less frequent in the ILE group. Compared with all SLE cases, ILE
patients were less likely to have photosensitivity, malar rash, oral ulcers,
Raynaud's phenomenon, arthritis, low C3, low C4, positive anti-dsDNA, anti-Sm,
anti-RNP, anti-Ro and anti-La antibodies at baseline. Hazard analyses showed that
malar rash, oral ulcers, elevated anti-dsDNA and decreased C4 were associated
with SLE occurrence. In conclusion, this study suggests that ILE represents a
mild spectrum of lupus in which mucocutaneous and serological abnormalities are
associated with progression into SLE.
PMID- 10787008
TI - ANA negative systemic lupus erythematosus sera revisited serologically.
AB - OBJECTIVE: To better define the serology of a panel of sera from patients with a
clinical diagnosis of systemic lupus erythematosus (SLE) or subacute cutaneous
lupus erythematosus (SCLE) with a negative antinuclear antibody (ANA) test on
mouse liver. METHODS: Sensitive ELISA methods for anti-Ro/SSA, anti-La/SSB, and
anti-U1RNP were applied to a panel of 76 sera with either SLE or SCLE and a
negative ANA test on mouse liver. RESULTS: These sera had previously been shown
to have a high prevalence of anti-Ro/SSA (68%) and anti-La/SSB (27%) precipitins
respectively. None had precipitins to U1RNP or Sm. ELISA methodology revealed
that all of the sera 76/76 (100%) had elevated levels (> mean +/- 2 SD of a panel
of 21 normal sera) of anti-Ro/SSA, 36/76 (46%) had elevated levels of anti
La/SSB, and 27 of 76 (35%) had elevated levels of anti-U1RNP. CONCLUSION: The
subset of patients with SLE and SCLE with a negative ANA test on mouse liver
almost uniformly have antibodies to the Ro/SSA antigen by a sensitive ELISA. This
adds evidence to the idea that this is a more homogeneous disease subset within
the spectrum of SLE.
PMID- 10787009
TI - A longitudinal study of human cytomegalovirus serology and viruria fails to
detect active viral infection in 20 systemic lupus erythematosus patients.
AB - In this study, we investigated whether active human cytomegalovirus infection
could be detected in 20 systemic lupus erythematosus (SLE) patients over a one
year observation period by polymerase chain reaction on serial urine specimens
and by monitoring of IgG and IgM HCMV-specific antibody profiles in serial serum
samples. Of 788 urine samples analysed for the presence of human cytomegalovirus
DNA, only 2 specimens (0.25%) collected from two different patients contained
genuine human cytomegalovirus sequences as determined by polymerase chain
reaction and subsequent sequencing of the PCR products. These two patients had
one positive sample out of 36 samples or 40 samples, respectively. Nineteen of
the patients (95%) possessed IgG antibodies against human cytomegalovirus, while
9 (45%) produced IgM antibodies. However, none of the patients showed signs of an
active virus infection as judged by the stable anti-HCMV IgG or IgM antibody
levels during the observation period, nor was any correlation between disease
activity and HCMV serology/viruria observed. Of single serum samples of 26 age-
and sex-matched blood donors, 21 (81%) were HCMV IgG positive and 1 (3.8%) was
IgM seropositive. In conclusion, our data fail to establish an active human
cytomegalovirus infection in SLE patients.
PMID- 10787010
TI - Expression of complement regulatory proteins in diffuse proliferative
glomerulonephritis.
AB - This study assessed the expression of complement receptor 1 (CR1), decay
accelerating factor (DAF) and membrane inhibitor of reactive lysis (CD59) on the
erythrocytes and glomerulus of diffuse proliferative glomerulonephritis (DPGN) of
systemic lupus erythematosus (SLE) patients using flow cytometry and
immunofluorescence techniques to elucidate their role in the pathogenesis of
DPGN. Expression of CR1 on the erythrocytes and glomerulus of DPGN patients was
reduced compared with expression in normal subjects. However, expression of DAF
and CD59 was increased on both erythrocytes and glomerulus of DPGN patients,
suggesting the generation of a protective response against complement-mediated
injury.
PMID- 10787012
TI - Extensive lymphadenopathy as the first clinical manifestation in systemic lupus
erythematosus.
AB - Lymphadenopathy (LAP) is a frequent sign of systemic lupus erythematosus (SLE).
The lymph nodes are usually soft, nontender, varying in size from 0.5 cm to
several centimeters. However, generalized LAP in SLE is extremely rare, while to
our knowledge, the presentation of extensive LAP with blocks of retrosternal,
mesenteric, and retroperitoneal nodes has not been previously reported as the
first clinical manifestation of the disease. In this report we describe a patient
with extensive LAP and active SLE and we point out that generalized LAP should be
included among the clinical findings indicating disease activity in SLE patients.
PMID- 10787011
TI - Serum levels of soluble Fas correlate with indices of organ damage in systemic
lupus erythematosus.
AB - OBJECTIVE: To evaluate whether the levels of soluble form of the Fas apoptosis
antigen (sCD95/sFas) varied from those of healthy control subjects in a group of
patients with systemic lupus erythematosus (SLE). This was done to determine
whether sFas has a role in either the disease activity or the organ damage in
SLE. METHODS: Serum levels of sFas were measured over a period of 4 y (277
determinations) in 39 Arab patients with SLE and 22 age-, gender-, and race
matched healthy controls using double antibody ELISA. SLEDAI scores for disease
activity and SLICC/ACR scores for cumulative organ damage were determined. Serum
levels of acute phase reactants, complement, inflammatory cell counts, levels of
autoantibodies, and kidney and liver function test results were obtained
retrospectively from clinical records. RESULTS: sFas levels were significantly
higher in patients with SLE (n = 39, 277 determinations) (0.60 ng/ml +/- 0.38)
than in healthy controls (n = 22) (0.26 ng/ml +/- 0.11) (P < 0.00001). The levels
of sFas correlated with SLICC/ACR (r = 0.36; P < 0.02), but not with SLEDAI. sFas
correlated with renal and liver function tests measured by s-creatinine (r =
0.38; P < 0.0001), creatinine clearance (r = -0.30, P < 0.001), s-albumin (r =
0.28, P < 0.0001), and ALT (r = 0.35; P < 0.00001), but did not correlate with
the levels of acute phase reactants. CONCLUSION: sFas is elevated in sera of SLE
patient. Since sFas correlates with indices of organ damage but not with disease
activity, it may be a marker of organ damage in SLE and may act to protect
certain organs from further damage by inhibiting Fas-mediated apoptosis.
PMID- 10787013
TI - Systemic lupus erythematosus presenting with a reticular erythematous mucinosis
like condition.
AB - We report the case of a woman with clinical and histopathological features of
reticular erythematous mucinosis syndrome (REM) who six years later developed
diagnostic criteria for systemic lupus erythematosus (SLE). Two biopsies
performed at the same area initially showed mucin dermal deposits and further
development of characteristic dermo-epidermal changes of lupus erythematosus. Our
findings suggest that SLE may present with an REM-like condition.
PMID- 10787014
TI - Intramedullary tuberculosis manifested as Brown-Sequard syndrome in a patient
with systemic lupus erythematosus.
AB - A 25-year-old girl presented with progressive deterioration of right side
weakness with decreased sensation on the left trunk. She had been treated with
high dose steroid due to autoimmune thrombocytopenia for 2 months. Clinical,
laboratory and immunologic studies revealed that she had systemic lupus
erythematosus (SLE), MRI of spinal cord showed marginal contrast enhancing and
fluid containing mass in the cord of the C5-6 level, suggesting intramedullary
abscess. She underwent surgery of mass removal with biopsy. The pathologic
findings from cord tissues revealed numerous acid fast bacilli (AFB) in necrotic
tissues. After surgery and anti-tuberculous treatment, her neurologic symptoms
were markedly improved with restoration of right side motor weakness. To our
knowledge, this is the first case report of intramedullary tuberculosis in a
patient with SLE. Since intramedullary tuberculosis may sometimes mimic
neurologic complication of SLE itself, it may pose diagnostic and therapeutic
confusion for clinicians. We report a case of spinal cord tuberculosis affecting
C5, 6 level which was manifested as Brown-Sequard syndrome in a patient with SLE.
PMID- 10787015
TI - Thymoma associated with systemic lupus erythematosus and immunologic
abnormalities.
AB - The association between Systemic Lupus Erythematosus (SLE) and thymoma occurs
with a greater frequency than dictated by coincidence alone. The immunologic
effects of thymectomy on the appearance and/or the course of SLE are still to be
elucidated. We report one case of SLE diagnosed at the same time as thymoma, and
two cases of thymoma associated with immunologic disorders in the absence of
clinical signs and symptoms diagnostic of SLE.
PMID- 10787016
TI - The possible role of interleukin-16 in the low incidence of HIV infection in
patients with systemic lupus erythematosus.
PMID- 10787017
TI - Coexistence of systemic lupus erythematosus and myasthenia gravis.
PMID- 10787019
TI - Appropriateness of hospital utilisation in Italy.
AB - The purpose of this study was to determine the extent of inappropriate hospital
admission and inappropriate days of stay and the effect of variables on such
inappropriateness on an adult population in Italy. A review was made of medical
records of patients admitted to any one of the following specialities: medicine,
surgery, gynaecology or traumatology/orthopaedics at one of five hospitals
located respectively in Siena, Frosinone, Rome and Catanzaro, and who were in
patients during one of four pre-selected index days. To determine the
appropriateness of hospital admission and length of hospitalisation, a
retrospective application was made using the Italian version of Appropriateness
Evaluation Protocol (AEP). A total of 1299 patient days were reviewed. 14.2% of
the hospital admissions and 37.3% of the number of hospitalisation days were
judged to be inappropriate. Multiple logistic regression analysis showed that
inappropriate admission was significantly increased with relation to: greater
distance from hospital to patient's home; admission to a medical ward; planned
admissions; and admission over a weekend. Multiple logistic regression analysis
indicated that the inappropriate number of days of hospitalisation was
significantly higher for medicine and for patients who were inappropriately
admitted. The main reason for categorising an admission as inappropriate was that
the patient's problems could be treated on an out-patient basis, and, for
inappropriate days of care, the physician was overtly cautious in the management
of a patient. Changing the physicians' behaviour and the organisation of hospital
activities may be effective in improving the quality and efficiency of hospital
care.
PMID- 10787018
TI - Two boys and a girl please and hold the mustard.
PMID- 10787020
TI - Geographical variations of place of death among Italian communities suggest an
inappropriate hospital use in the terminal phase of cancer disease.
AB - This study aimed to assess geographic variations of place of death among Italian
communities, to investigate the determinants of home death, and to examine trends
in the proportion of home deaths over a period of 8 y. A cross-sectional analysis
was performed on 13 provinces from two Italian regions (Liguria and Toscana), and
the geographic variations and determinants of home death were studied for the
17,597 residents, who died of cancer in 1991. Trends for both the regions of the
proportion of home deaths were examined for the period 1987 and 1995. A
remarkable heterogeneity in the observed proportion of home deaths among the 13
provinces was observed, ranging between 31.4 and 40.4% in Liguria and between
37.7 and 73.3% in Toscana. The estimated proportion of home deaths after
adjustment for age, gender, marital status, education, place of birth,
characteristics of the living area, and cancer site remained substantially the
same. The proportion of home deaths significantly increased with increasing age,
and years of education. It was higher among females, married and widowed
patients, native patients, and for residents in a semi-urban or rural areas. A
significant decrease in the percentage of patients who died at home between 1987
and 1995 in both regions was observed. The wide geographical and social
differences observed between and within the communities for the frequency of home
deaths are not explained by the distribution of known determinants, and possibly
suggest patterns of inappropriate hospital admissions in the terminal phase of
disease.
PMID- 10787021
TI - Which is the best deprivation predictor of foetal and infant mortality rates?
AB - This study investigates which, if any, population-based indicator of deprivation
best predicts foetal and infant mortality rates in England. For the year 1995,
the deprivation levels of 364 English Local Authorities were compared; using the
three commonly used indicators, Jarman score, Townsend score and percentage
unemployed. The predictive value of these for stillbirth, neonatal and infant
mortality rates was then calculated. The three deprivation indicators were highly
inter-correlated (r=0.866-0.924). For each mortality rate, the correlation with
deprivation did not differ significantly for the three indicators of deprivation.
We conclude, when comparing these outcomes in different areas of England, that
any of the three deprivation indicators may be used to adjust for deprivation.
PMID- 10787022
TI - Health hazards of unemployment--only a boom phenomenon? A study of young men and
women during times of prosperity and times of recession.
AB - BACKGROUND: It has been suggested that high unemployment rates in society may be
less harmful to the health of people than low unemployment rates. Therefore, a
study was carried out to compare, among young men and women, the relationship
between health and long-term unemployment during periods of rapid economic growth
'boom' and economic recession. METHODS: Two study groups were chosen at age 21 y
(5 y after compulsory schooling ended) from an industrial town in northern
Sweden. The first group (number 1083) was chosen and surveyed in 1986 (under
'boom' conditions); the second (number 898) was chosen in 1994 (under economic
recession conditions). The non-response rate was 2% for the boom group and 10%
for the recession group. The main outcome measurements examined were somatic and
psychological symptoms. RESULTS: Health criteria for general health among long
term unemployed young men and women did not differ between the group surveyed in
boom conditions and the group surveyed in recession conditions. The only
exception was for psychological symptoms, which scored lower among the men in the
recession group. Individual unemployment had a high explanatory power for poor
health, in particular, psychological ill health. CONCLUSIONS: When comparing
periods of boom and recession there was no difference in somatic and
psychological symptoms for those who were long-term unemployed. Thus, the trade
cycle appeared to have had no impact on their health.
PMID- 10787023
TI - Inequalities in health: raising awareness among health authority staff.
AB - A postal survey of all staff working for Bro Taf Health Authority (n = 237) was
carried out during August and September 1998. The survey was concerned with
tackling inequalities in health in terms of involvement, information needs,
priorities and working patterns. The aim was to raise awareness of the Health
Authority's commitment to tackling inequalities in health and to collect
employees' opinions on methods of working effectively towards greater equity. The
response rate was higher for senior grades (63%) than for basic grades (26%). Not
all employees had access to background documents and many expressed a need for
more information. There was a strong feeling that a change in working patterns
would be beneficial and staff were particularly concerned that internal
communications should be improved. The survey provided a good opportunity to
raise awareness of health inequality issues and was beneficial in providing an
opportunity for staff to express their opinions anonymously. Some suggestions
have already been implemented and others are incorporated in the Health
Authority's Equity Strategy.
PMID- 10787024
TI - Causes and effects of road traffic accidents in Saudi Arabia.
AB - In Saudi Arabia the motor vehicle is the main means of transportation. Between
1971 and 1997; 564,762 people died or were injured in road traffic accidents, a
figure equivalent to 3.5% of the total population in Saudi Arabia. During this
period 66,914 people have died on the roads in Saudi Arabia due to road
accidents, amounting to one person killed and four injured every hour. Over 65%
of accidents occur because of vehicles travelling at excess speed and/or drivers
disobeying traffic signals. Of deaths in Ministry of Health hospitals, 81% are
due to road traffic accidents and 20% of their beds are occupied by traffic
accidents victims. Also, 79.2% of patients admitted to Riyadh Armed Forces
Hospital with spinal injuries has sustained their injuries as a result of a motor
vehicle accident. We recommend compulsory use of safety seat belts in vehicles
and the setting up of a new database to collect, store and analyse information
relating to the road traffic accidents.
PMID- 10787025
TI - Chemical incident management: gaseous emissions from a stockpile of coal.
AB - Spontaneous combustion of coal releases a wide range of airborne pollutants
which, in high concentrations, may be hazardous to health. Little is known about
how the effects on health change in relation to the release of multiple
substances. This article reports an incident in which a stockpile of coal
released potentially harmful gases into the environment. Although the resultant
health effects reported were few, the co-ordinated response by local authorities
and health authorities highlighted the advantage of a multidisciplinary approach.
Public health departments need to be aware of major chemical hazards within their
district. Prompt environmental monitoring and exposure measurement needs to be
arranged as this is crucial to making an appropriate response. Updated registers
are needed from private companies and public bodies; who can provide timely
measurements of chemical hazards. Health districts with more than one local
authority may benefit from pooling resources and knowledge in order to prepare
for such an incident.
PMID- 10787026
TI - Psychiatric ill health and distribution of body fat mass among female immigrants
in Sweden.
AB - Given the association between psychiatric factors and obesity, the aims of the
present study were to identify these variables among native Swedish as well as
immigrant women, and to compare the prevalence of psychiatric ill health in women
of foreign ethnicity with Swedish women. Information on melancholia, life
satisfaction, sleeping problems, and use of psychoactive drugs as well as alcohol
and smoking habits was obtained from questionnaires in a randomly selected
population (n = 1464, participation rate 78%, aged 40 y). Height, body weight and
circumferences of waist and hip were self-measured, so allowing calculations of
the body mass index (BMI) and the waist to hip ratio (WHR) to be made. Among
those who responded 246 (21.9%) were immigrants, divided into the following
demographic clusters Nordic countries; Rest of Europe; and Non-European. Among
native Swedes, use of psychoactive drugs and melancholy were associated with both
BMI and WHR. BMI-associated with use of antidepressants in women from Nordic
countries with a short duration of stay, and in subjects with a long duration of
residence, was related to life satisfaction. Among subjects from the Rest of
Europe, the use of hypnotics was negatively related to BMI, and life satisfaction
was positively associated with WHR. Among Non-Europeans with a long duration of
residence, BMI was positively connected to the use of anxiolytics and,
negatively, to life satisfaction. Furthermore, melancholy was positively
associated with WHR (borderline, P=0.086) in Non-Europeans. Subjects from Nordic
countries were characterised by a relatively low use of psychoactive drugs and
infrequent insomnia. In contrast, subjects from the Rest of Europe with short
duration of stay showed a relatively extensive use of psychoactive drugs, and the
Non-European group with short duration of stay experienced frequent insomnia, and
a low degree of life satisfaction as well as high degree of melancholy. The
association between psychiatric factors and obesity is not uniform across ethnic
groups, suggesting a combination of genetic predisposition and psychosocial
vulnerability. The high prevalence of psychiatric ill health among some ethnic
groups should be a matter of public health concern.
PMID- 10787027
TI - A study of colo-rectal carcinoma in the Asian and European populations in the
city of Leicester from 1981 to 1991.
AB - For many years clinical reports have suggested that colo-rectal cancer is
uncommon in the Asian population resident in England and a report in 1990
confirmed this in Asians living in Bradford. This study aims to establish the
incidence of colo-rectal cancer in the Asian population resident in the city of
Leicester during the 11 y period 1 January 1981-31 December 1991. The relative
frequency of colo-rectal carcinoma in Asians compared to Europeans over the
period studied was 0.16 (Asian/European, 95% confidence interval (CI) 0.04-0.75).
This difference was statistically significant and further analysis showed that
there was a real trend with an increased relative frequency amongst the younger
age groups. Although there was a significantly lower incidence of colo-rectal
carcinoma in the Asian population in Leicester city over the period studied it is
unknown whether this is due to environmental or genetic factors. During the next
decade it is likely to become clearer as to whether this difference will persist
or whether there will be an increase in the incidence of colo-rectal carcinoma in
Asians in Leicestershire.
PMID- 10787028
TI - Issues arising from two related cases of childhood tuberculous meningitis.
AB - Two cases of childhood meningitis occurred in the same school within two weeks.
The cases were cousins. The first case died and the aetiology was confirmed as
tuberculous following a gene probe of a culture from the meningeal tissues at
postmortem. The second case, with similar life threatening clinical features
compatible with tuberculous meningitis, recovered. Seventy-seven contacts of the
two cases among the immediate and extended families were screened. The adult
sources of the infection were found to be two aunts of the second case, who were
nurses working in the same nursing home. A further 73 contacts of the adult cases
were identified. A total of eight close contacts to the aunts were given
chemoprophylaxis and three were treated for tuberculosis. Contact tracing was
also undertaken in the nursing home but no further cases were identified. These
two cases highlight the difficulties in making a rapid diagnosis in tuberculous
meningitis, the difficulties in handling media and public concern with limited
information, and deciding on the appropriate level of contact tracing in special
circumstances.
PMID- 10787029
TI - Community paediatrics moves on--an analysis of changing work patterns 1994-97.
AB - OBJECTIVES: To describe the current clinical workload of the modern community
paediatrician; to outline the changes in this role over recent years and examine
the reasons for these. DESIGN AND SETTING: The design is a retrospective analysis
of data routinely collected for contracting purposes. Nottingham community
paediatric service 1994-97 is the setting. MAIN OUTCOME MEASURES: These are the
characteristics of patients seen, sources of referral, locations of clinical
contact, referral rates by area. RESULTS: 36,710 appointments were offered over
the time period studied. The non-attendance rate was 17%. Pre-school children
made up the largest group seen. Most referrals were from health visitors (23%)
and school nurses (29%). There has been a small but significant increase in the
numbers of children seen who have developmental problems and disability, and due
to child protection issues between the time periods. There has been a shift in
the proportions of children seen in a local health centre referral clinic (9.8%
increase during 1994-97) rather than in a school setting. Twice as many children
are referred to the community paediatrician from inner city areas than from the
surrounding county areas. CONCLUSION: The transfer of child health surveillance
to the primary health care team and the increased training of community
paediatricians, has resulted in community paediatricians developing an
increasingly specialised role particularly in the areas of child growth and
development, disability, social and behavioural paediatrics.
PMID- 10787030
TI - N-[4-(3-ethoxy-2-hydropropoxy)phenyl] acrylamide selectively induces apoptosis of
cerebellar granule cells in vivo and in vitro in rats.
AB - Oral administration of N-[4-(3-ethoxy-2-hydropropoxy)phenyl] acrylamide (EHA)
induced selective granule cell destruction in the granular layer of the
cerebellar cortex together with neurological signs, such as delayed righting
reflex, gait or truncal ataxia, and convulsion. Neuropathologically, it caused
multifocal granule cell destruction with nuclear pyknosis and spongiosis of the
neuropile in the granular layer. Other neurons, including Purkinje cells, were
spared. Ultrastructurally, damaged granule cells showed aggregation of nuclear
chromatin and cytoplasmic edema, but cytoplasmic organelles were preserved. The
brain uptake index of 14C-labeled EHA was similar to that of H2O. When EHA was
added to rat cerebellar tissue cultures, only the granule cells showed nuclear
pyknosis, aggregation of nuclear chromatin, and karyorrhexis with cytoplasmic
swelling. These granule cells were positive for DNA fragmentation by the TUNEL
method. These results suggest that EHA permeates the blood vessel wall and
directly affects the cerebellar granule cells, resulting in selective granule
cell apoptosis.
PMID- 10787031
TI - Characterization of chromosome 17 abnormalities in medulloblastomas.
AB - Loss of portions of chromosome 17p, usually through the formation of i(17qp) is a
well-known finding in medulloblastomas. Loss of heterozygosity (LOH) studies,
however, occasionally demonstrate loss of the more distal portions of 17p, a
pattern which is more consistent with a terminal deletion. Here we use a
combination of routine karyotyping, fluorescence in situ hybridization (FISH) and
LOH studies on four medulloblastoma cell lines and one xenograft to demonstrate
the spectrum of chromosome 17 abnormalities which occur in these tumors. Cell
line D-556 Med showed a typical dicentric i(17q) and cell line D-721 Med showed
two normal copies of chromosome 17 by all methods. Cell line D-425 Med showed
loss of terminal 17p by LOH, while the karyotype showed what appeared to be an
i(17q). FISH and chromosome 17 painting, however, demonstrated that the abnormal
chromosome 17 was actually formed through an unbalanced translocation involving
two copies of chromosome 17, with breakpoints at p12 and q11-1, an explanation
which reconciled the cytogenetic and LOH findings. Cell line D 581 Med had a
terminal deletion at 17p11.2. The finding of two cells with i(17q) in this case
by interphase FISH suggests that the terminal deletion arose from breakage of an
i(17q). Finally, xenograft D 690 Med showed LOH for regions distal to 17p12,
whereas karyotyping, FISH using probes on 17p, and chromosome 17 painting showed
two intact copies of chromosome 17. This pattern can be explained by homologous
recombination. These data support the concept that the critical deletion of 17p
can occur through a variety of mechanisms in the medulloblastoma. The losses may
occur through typical i(17q), as well as other mechanisms such as terminal
deletions, possibly through breakage of i(17q), unbalanced translocations and
homologous recombination.
PMID- 10787033
TI - Retrospective study of Creutzfeldt-Jakob disease in Belgium: neuropathological
findings.
AB - Creutzfeldt-Jakob disease (CJD) is a spongiform encephalopathy that affects about
1 in 10(6) inhabitants in most countries. Recently, a new variant of CJD has been
linked to the epidemic of bovine spongiform encephalopathy. Therefore, vigilance
concerning the disease's incidence has been increased. We conducted a
comprehensive, nation-wide and retrospective study. In 79 Belgian autopsies, we
found the characteristic triad of spongiosis, neuronal loss and reactive gliosis.
The occipital cortex was most affected, while the cerebellum was mostly spared.
Immunohistochemistry was performed using hydrated autoclave pretreatment and
several monoclonal antibodies directed against the prion protein. We identified
prion-immunoreactive patterns and locations reflecting the important
heterogeneity, independently of the antibody that was used. Granular prion
immunoreactivity was observed in astrocytes. We studied the regional intensity of
the prion immunostaining and determined that the frontal cortex with 95% positive
immunoreactivity was best suited for a biopsy. We studied the disease duration in
sporadic CJD patients who showed neuropathological lesions of other
neurodegenerative disorders (such as Alzheimer's disease). The study shapes the
framework in which a prospective neuropathological registry will be able to
function.
PMID- 10787032
TI - alpha-Synuclein immunoreactivity in dementia with Lewy bodies: morphological
staging and comparison with ubiquitin immunostaining.
AB - alpha-Synuclein is a presynaptic protein recently identified as a specific
component of Lewy bodies (LB) and Lewy neurites. The aim of this study was to
assess the morphology and distribution of alpha-synuclein immunoreactivity in
cases of dementia with LB (DLB), and to compare alpha-synuclein with ubiquitin
immunostaining. We examined substantia nigra, paralimbic regions (entorhinal
cortex, cingulate gyrus, insula and hippocampus), and neocortex (frontal and
occipital association cortices) with double alpha-synuclein and ubiquitin
immunostaining in 25 cases meeting neuropathological criteria for DLB. alpha
Synuclein immunostaining was more specific than ubiquitin immunostaining in that
it differentiated LB from globose tangles. It was also slightly more sensitive,
staining 4-5% more intracytoplasmic structures, especially diffuse alpha
synuclein deposits that were ubiquitin negative. In addition to LB, alpha
synuclein staining showed filiform and globose neurites in the substantia nigra,
CA2-3 regions of the hippocampus, and entorhinal cortex. A spectrum of alpha
synuclein staining was seen in substantia nigra: from diffuse "cloud-like"
inclusions to aggregated intracytoplasmic inclusions with variable ubiquitin
staining to classic LB. We hypothesize that these represent different stages in
LB formation.
PMID- 10787034
TI - Degeneration of the cerebellar dentate nucleus in corticobasal degeneration:
neuropathological and morphometric investigations.
AB - To resolve the controversy regarding the involvement of the dentate nucleus in
corticobasal degeneration (CBD), an entire profile of the dentate nucleus was
exposed in a sagittal plane and divided into four fields, and the number of
neurons in each filed was counted separately using a computer-assisted analyzer
in five cases of CBD and compared to those from seven age-matched controls. The
size of the nucleus and the number of neurons were significantly reduced in all
five cases of CBD. The neuronal loss had a definite regional predilection, more
severe in the caudolateral neodentatum than in the rostromedial palaeodentatum,
and was accompanied by grumose degeneration and astrogliosis which paralleled the
severity of the neuronal loss. Thus, the dentate nucleus appears to be a cardinal
target in CBD.
PMID- 10787035
TI - Severe hypoplasia of medullary arcuate nucleus: quantitative analysis in sudden
infant death syndrome.
AB - The human arcuate nucleus (ARCn) is postulated to be homologous to ventral
medullary cells involved in chemoreception, and respiratory and blood pressure
responses. Abnormalities in central respiratory control may result from
dysfunction of this anatomic ventral area. We evaluated the changes of the
neuronal population of the medullary ARCn in infants victims of the sudden infant
death syndrome (SIDS). In this study we tested the hypothesis that anatomical
deficiency of the ARCn is associated with SIDS. The volume and neuronal density
of the ARCn were morphometrically quantified with an image analyzer in 36 cases
of SIDS and 12 age-matched controls. We found a marked hypoplasia in the SIDS
ARCn compared to controls and, particularly, in 11 SIDS cases (30%) in which the
ARCn exhibited a severe hypoplasia, being almost totally absent. Three
dimensional reconstructions and morphometric measurements of ARCn confirmed this
marked hypoplasia in all the serial sections examined (P = 0.0001) and the
reduced neuronal density (P = 0.0025) in relation to control cases. In conclusion
these abnormalities observed in the ARCn are consistent with the idea that ARCn
dysfunction plays an important role among the causative factors of sudden infant
death. The hypoplasia of the ARCn represents the most frequent congenital
abnormality in our experience, and can be a plausible morphological substrate for
a subset of SIDS.
PMID- 10787036
TI - Neuronal damage of the substantia nigra in HIV-1 infected brains.
AB - Extrapyramidal motor disorders are frequently noted in HIV-1-infected patients.
In the present study, the substantia nigra was analyzed morphometrically to
detect neuronal changes which might contribute to the pathogenetic mechanisms
causing extrapyramidal motor dysfunction in HIV-1-infected patients. The
numerical density and the size of pigmented, non-pigmented small, and non
pigmented large neurons in four nuclei of the substantia nigra pars compacta
(antero-medial, antero-intermediolateral, postero-lateral, and postero-medial
nuclei) in HIV-1-infected patients and in age-matched normal controls were
determined. In HIV-1-infected brains, the numerical density of total neurons
(i.e., pigmented and non-pigmented) as well as of pigmented neurons was
significantly decreased, whereas that of non-pigmented neurons was not
significantly changed in all investigated nuclei of the substantia nigra as
compared to normal controls. A specific pattern of increase and decrease of
nonpigmented large and non-pigmented small neurons was observed. The size of
total neurons (pigmented and nonpigmented neurons) and of pigmented neurons was
significantly reduced in all investigated nuclei of HIV-1-infected brains. The
results suggest that neuronal degeneration in the substantia nigra commonly
occurs and may be related to extrapyramidal symptoms in HIV-1-infected patients.
PMID- 10787037
TI - Blood-brain barrier permeability in the periventricular areas of the normal mouse
brain.
AB - The main objective of this study was to assess the blood-brain barrier (BBB)
permeability in periventricular areas of the normal mouse brain to test the
hypothesis that the fragility of the BBB in periventricular areas may play a role
in periventricular white matter lesions. Vascular permeability to intravenously
injected horseradish peroxidase (HRP) was examined in the periventricular areas
of adult mouse brain using light and electron microscopy. Staining for HRP
appeared in the periventricular area adjacent to medial side of the lateral
ventricle as well as in BBB-free areas, in the lateral septal nucleus, in the
medial portion of the hippocampus and in the dorsal portion of the thalamus. In
addition, the staining for HRP appeared in ependymal cell layer located near the
choroid plexus and was found early after HRP injection in the wall of some
vessels located at medial side of the optic tract. Ultrastructural examination of
the vessel wall revealed that staining for HRP in the perfusion-fixed mice after
circulation of the tracer for 5 min appeared in the perivascular space, in the
basal lamina, in several vesicular profiles of the endothelial cell cytoplasm
including abluminal pits, in vesicular profiles of perivascular cells and in the
adjacent extracellular space. In the mice perfusion-fixed after HRP circulation
for 90 min, staining for HRP in the vessels at medial side of the optic tract
appeared in the cytoplasm of the perivascular cells, in vesicular structures of
the endothelial cell cytoplasm such as plasmalemmal vesicles, endosomes and
multivesicular bodies and occasionally in the vascular basal lamina. No clear
staining reaction for HRP was found in the periventricular areas adjacent to
lateral side of the lateral ventricles. These findings indicate that the BBB in
the periventricular area adjacent to medial side of the lateral ventricle near
the root of the choroid plexus is not so tight as it is in the cortex or in the
lateral periventricular areas, and suggest that the perivascular cells play a
scavenger role in the periventricular area as a component of the BBB. In
addition, they indicate that blood-borne macromolecules can also invade the areas
adjacent to the ventricles such as the lateral septal nucleus, the medial portion
of the hippocampus and the dorsal portion of the thalamus.
PMID- 10787038
TI - Expression of the alpha and beta subunits of Ca2+/calmodulin kinase II in the
cerebellum of jaundiced Gunn rats during development: a quantitative light
microscopic analysis.
AB - The homozygous (jj) jaundiced Gunn rat model for hyperbilirubinemia displays
pronounced cerebellar hypoplasia. To examine the cellular mechanisms involved in
bilirubin toxicity, this study focused on the effect of hyperbilirubinemia on
calcium/calmodulin-dependent kinase II (CaM kinase II). CaM kinase II is a
neuronally enriched enzyme which performs several important functions.
Immunohistochemical analysis of alternating serial sections were performed using
monoclonal antibodies for the alpha and beta subunits of CaM kinase II.
Measurements were made of the total numbers of stained cells in each of the deep
cerebellar nuclei and of Purkinje and granule cell densities in cerebellar
lobules II, VI, and IX. The beta subunit was present in Purkinje cells and deep
cerebellar nuclei of both groups at all ages, but only granule cells which had
migrated through the Purkinje cell layer showed staining for beta subunit;
external granule cells were completely negative. Many Purkinje cells had
degenerated in the older animals, and the percent of granule cells stained for
beta subunit was significantly reduced. The alpha subunit was found exclusively
in Purkinje cells, although its appearance was delayed in the jaundiced animals.
Sulfadimethoxine was administered to some jj rats 24 h or 15 days prior to
sacrifice to increase brain bilirubin concentration. Results showed that
bilirubin exposure modulated both alpha and beta CaM kinase II subunit expression
in selective neuronal populations, but sulfadimethoxine had no acute effect on
enzyme immunoreactivity. Thus, developmental expression of the alpha and beta
subunits of CaM kinase II was affected by chronic bilirubin exposure during early
postnatal development of jaundiced Gunn rats.
PMID- 10787039
TI - Neuronal nuclear DNA fragmentation in the aged canine brain: apoptosis or nuclear
DNA fragility?
AB - Neuronal DNA fragmentation, as revealed with the method of in situ end-labeling
of nuclear DNA fragmentation (TUNEL), has been reported in both the canine and
human brains in normal ageing, and in some human age-related neurodegenerative
diseases. These results have suggested that apoptosis plays an important role in
age-related neuronal loss. It is not clear, however, whether the TUNEL method is
highly specific for apoptosis, as DNA fragmentation also occurs in the late
stages o necrosis. In this study we have examined 27 dogs aged from 8 to 18
years, to investigate the occurrence of nuclear DNA fragmentation. An autolysis
index based on current histological criteria was assigned to each animal to
evaluate the effects of autolysis on nuclear DNA integrity. Our results have
shown that neuronal nuclear DNA fragmentation is frequent in aged dogs, although
it is not accompanied by apoptotic morphology. Yet, a positive relation between
TUNEL labelling and the degree of tissue autolysis was observed. In contrast, no
TUNEL labelling was detected in young control dogs despite autolysis indices
being similar to those in aged dogs. Taken together, these results suggest that
neuronal nuclear DNA fragmentation is an age-related phenomenon, not due to
apoptosis, whenever other factors render neuronal DNA more susceptible to
autolytic fragmentation. We confirm the effect of autolysis in a subpopulation of
neurons in the aged canine brain, inducing nuclear DNA fragmentation.
PMID- 10787040
TI - Age-related plaque morphology and C-terminal heterogeneity of amyloid beta in
Dutch-type hereditary cerebral hemorrhage with amyloidosis.
AB - The evolvement of amyloid beta (Abeta) deposition in the frontal cerebral cortex
of 24 patients of increasing age with Dutch-type hereditary cerebral hemorrhage
with amyloidosis (HCHWA-D) was studied using end-specific monoclonal antibodies
to Abetax-42 (Abeta42) or Abetax-40 (Abeta40) and markers for degenerating
neurites. Abeta42 immunostaining revealed parenchymal Abeta deposits with a
heterogeneous morphology and distribution, i.e., clouds, fine/dense diffuse,
coarse, and homogeneous plaques. Clouds and diffuse plaques were associated with
glial Abeta granules. Abeta40 labeling was absent in clouds/fine diffuse plaques,
inconsistent and variably intense in dense diffuse/coarse plaques and consistent
in homogeneous plaques. In a subset of Abeta40-positive plaques, degenerating
neurites--without tauopathy--and/or amyloid cores were observed. Electron
microscopy revealed no apparent amyloid fibrils in fine diffuse plaques, small
bundles of fibrils in dense diffuse/homogeneous plaques, and amyloid masses in
coarse plaques. The parenchymal Abeta pathology was age-related: the ratio of
fine to dense diffuse plaques decreased with age, clouds were limited to younger
patients; coarse plaques to the oldest old. Homogeneous/cored plaques were
present most consistently in older patients. Plaque density did not increase with
age. Vascular Abeta deposits stained for both Abeta species, but exclusively
Abeta42-positive, presumably recent deposits were also observed. This study
suggests that HCHWA-D is a model of plaque evolution in which clouds leave fine
diffuse plaques, which may become dense diffuse and ultimately coarse or
homogeneous plaques.
PMID- 10787041
TI - Neuroaxonal leukodystrophy associated with congenital cutis laxa: report of an
autopsy case.
AB - A male patient, who was born with congenital cutis laxa characterized by
cutaneous laxity due to the degeneration of elastic fibers, presented with an
arrest of mental and motor development at the age of 3 years. The progressive
decline of the psychomotor abilities led to the patient's death at the age of 4
years and 9 months. An autopsy revealed extensive white matter degeneration,
characterized by the formation of numerous neuroaxonal spheroids and a diffuse
loss of axons and myelin sheaths. The centrum semiovale and the cerebellar white
matter were the most severely affected. The ultrastructure of the spheroids was
consistent with a dystrophic type of axonal swelling. Neurons of the cerebral
cortex, cerebellar cortex, and some brain stem nuclei were lost in moderate to
severe degrees, and there were relatively few neuroaxonal spheroids in the gray
matter. The pallidum and substantia nigra were well preserved. Neuroaxonal
leukodystrophy, in which the spheroid formation predominantly affects the white
matter, is the rarest variant of primary neuroaxonal dystrophies, and there are
very few reports of autopsied cases. Among the reported cases, two Japanese
siblings had congenital skin lesions similar to those of our case. The unique
association of neuroaxonal leukodystrophy and congenital cutis laxa may form a
distinct variant in this disease category.
PMID- 10787042
TI - A case of Miller-Dieker syndrome in a family with neurofibromatosis type I.
AB - The Miller-Dieker syndrome (type I lissencephaly) is a neuronal migration
disorder which is associated with microdeletions in the short arm of chromosome
17. Neurofibromatosis type I (NF1) is an autosomal dominant condition associated
with mutations in the long arm of chromosome 17, and characterised by
neurofibromas, cafe-au-lait spots and axillary freckling. The neonatal period for
a female infant born at 39 weeks gestation by emergency Caesarean section was
complicated by frequent epileptic seizures as well as hypotonia. A computed
tomography scan revealed evidence of lissencephaly, and chromosomal analysis
showed a microdeletion on the short arm of chromosome 17 (17p13.3), confirming
the diagnosis as Miller-Dieker syndrome. The child died at the age of 4 years and
examination of the brain confirmed lissencephaly with a thickened cortex,
deficient white matter, and grey matter heteropias. The mother had cafe-au-lait
spots, and axillary freckling. In addition, the mother's and maternal
grandmother's genetic analysis showed identical mutations in the
neurofibromatosis I gene on the long arm of chromosome 17, confirming the
diagnosis of NF1. The child did not possess the mutation. This case illustrates a
rare neuronal migration disorder appearing in a child from a family with a
history of NF1.
PMID- 10787043
TI - Pathology of Madras type of motor neuron disease (MMND)--a histological and
immunohistochemical study.
AB - A neuropathological report of Madras type of motor neuron disease (MMND) is
presented and the differences from other forms of MND are discussed. An 18-year
old girl presented with nerve deafness and slowly progressive bulbo-spinal
muscular atrophy, characteristic of MMND. Post-mortem examination of the spinal
cord showed a severe loss of anterior horn cells, prominent dilatation of
vessels, diffuse, but sparse sprinkling of microglial cells and lymphocytes, and
demyelination and sclerosis of the ventrolateral columns. Neuronal depletion and
marked gliosis was noted in the cochlear nucleus on both sides, while other
bulbar motor nuclei were also involved. The cochlear nerve showed demyelination
and axonal loss. Trigeminal and vestibular ganglia revealed features of
ganglionitis. The possibility of an inflammatory aetiology for MMND needs to be
considered.
PMID- 10787045
TI - Microinjection of heme oxygenase genes rescues phytochrome-chromophore-deficient
mutants of the moss Ceratodon purpureus.
AB - In protonemal tip cells of the moss Ceratodon purpureus (Hedw.) Brid.,
phototropism and chlorophyll accumulation are regulated by the photoreceptor
phytochrome. The mutant ptr116 lacks both responses as a result of a defect in
the biosynthesis of phytochromobilin, the chromophore of phytochrome, at the
point of biliverdin formation. The rescue of the phototropic response and of
chlorophyll synthesis were tested by injecting different substances into tip
cells of ptr116. Microinjection was first optimised with the use of fluorescent
dyes and an expression plasmid containing a green fluorescent protein (GFP) gene.
Injected phycocyanobilin, which substitutes for phytochromobilin, rescued both
the phototropic response and light-induced chlorophyll accumulation in ptr116.
The same results were obtained when expression plasmids with heme oxygenase genes
of rat (HO-1) and Arabidopsis thaliana (L.) Heynh. (HY1) were injected. Heme
oxygenase catalyses the conversion of heme into biliverdin. Whereas HY1 has a
plastid target sequence and is presumably transferred to plastids, HO-1 is
proposed to be cytosolic. The data show that ptr116 lacks heme oxygenase enzyme
activity and indicate that heme oxygenases of various origin are active in
Ceratodon bilin synthesis. In addition, it can be inferred from the data that the
intracellular localisation of the expressed heme oxygenase is not important since
the plastid enzyme can be replaced by a cytosolic one.
PMID- 10787044
TI - Developmentally regulated expression of two MADS-box genes, MdMADS3 and MdMADS4,
in the morphogenesis of flower buds and fruits in apple.
AB - Two MADS-box genes, MdMADS3 and MdMADS4, were isolated from the apple (Malus x
domestica Borkh.) cultivar Fuji, and their spatial and temporal expression
patterns were studied during morphological differentiation of the flower buds and
the fruits. Both MdMADS3 and MdMADS4 showed high sequence similarities to FBP2
from petunia, TM5 from tomato, and AGL2, AGL4 from Arabidopsis. Although MdMADS3
was expressed in the inner three whorls of the floral primordium, its expression
was hardly detectable in developing fruit. The second gene, MdMADS4, was
ubiquitously expressed in the inflorescence meristem, floral meristem, all four
floral organs, and fruit. Moreover, MdMADS4 expression was high in the vascular
bundles assigned to the floral tube and the carpellary vascular bundles in fruit
at early developmental stages. The MdMADS4 transcript also accumulated in embryos
of the developing seeds. These results suggest that MdMADS3 and MdMADS4 are
involved in different functions, and that MdMADS4 may function in the important
events controlling flower and fruit development.
PMID- 10787046
TI - Heteroblasty in Arabidopsis thaliana (L.) Heynh.
AB - Heteroblasty in Arabidopsis thaliana was analyzed in a variety of plants with
mutations in leaf morphology using a tissue-specific beta-glucuronidase gene
marker. Some mutants exhibited their mutant phenotypes specifically in foliage
leaves. The phenotypes associated with the foliage-leaf-specific mutations were
also found to be induced ectopically in cotyledons in the presence of the lec1
mutation. Moreover, the features of an emfl lec1 double mutant showed that
cotyledons can be partially converted into carpelloids. When heteroblastic traits
were examined in foliage leaves in the presence of certain mutations or natural
deviations by histochemical analysis of the expression of the tissue-specific
marker gene, it was found that ectopic expression of the developmental program
for the first foliage leaves in lec1 cotyledons seemed to affect the
heteroblastic features of the first set of foliage leaves, while foliage leaves
beyond the third position appeared normal. Similarly, in wild-type plants,
discrepancies in heteroblastic features, relative to standard features, of
foliage leaves at early positions seemed to be eliminated in foliage leaves at
later positions. These results suggest that heteroblasty in foliage leaves might
be affected in part by the heteroblastic stage of the preceding foliage leaves
but is finally controlled autonomously at each leaf position.
PMID- 10787047
TI - The Lupinus albus class-III chitinase gene, IF3, is constitutively expressed in
vegetative organs and developing seeds.
AB - A cDNA fragment encoding a Lupinus albus. L. class-III chitinase, IF3, was
isolated, using a cDNA probe from Cucumis sativus L., by in-situ plaque
hybridization from a cDNA library constructed in the Uni-ZAP XR vector, with
mRNAs isolated from mature lupin leaves. The cDNA had a coding sequence of 293
amino acids including a 27-residue N-terminal signal peptide. A class-III
chitinase gene was detected by Southern analysis in the L. albus genome. Western
blotting experiments showed that the IF3 protein was constitutively present
during seed development and in all the studied vegetative lupin organs (i.e.,
roots, hypocotyls and leaves) at two growth stages (7- and 20-d-old plants).
Accumulation of both the IF3 mRNA and IF3 protein was triggered by salicylic acid
treatment as well as by abiotic (UV-C light and wounding) and biotic stress
conditions (Colletotrichum gloeosporioides infection). In necrotic leaves, IF3
chitinase mRNA was present at a higher level than that of another mRNA encoding a
pathogenesis-related (PR) protein from L. albus (a PR-10) and that of the rRNAs.
We suggest that one role of the IF3 chitinase could be in the defense of the
plant against fungal infection, though our results do not exclude other functions
for this protein.
PMID- 10787048
TI - The Golgi apparatus of the scaly green flagellate Scherffelia dubia: uncoupling
of glycoprotein and polysaccharide synthesis during flagellar regeneration.
AB - The flagella of the green alga Scherffelia dubia are covered by scales which
consist of acidic polysaccharides and glycoproteins. Experimental deflagellation
results in the regeneration of flagella complete with scales. During flagellar
regeneration, scales are newly synthesized in the Golgi apparatus, exocytosed and
deposited on the growing flagella. Flagellar regeneration is dependent upon
protein synthesis and N-glycosylation, as it is blocked by cycloheximide and
partially inhibited by tunicamycin. Metabolic labeling with
[35S]methionine/cysteine demonstrated that scale-associated proteins were not
newly synthesized during flagellar regeneration, suggesting that the proteins
deposited on regenerating flagella were drawn from a pool. Quantitative
immunoelectron microscopy using a monospecific antibody directed against a scale
associated protein of 126 kDa (SAP126) revealed that the pool of SAP126 was
primarily located at the plasma membrane, with minor labeling of the scale
reticulum and trans-Golgi cisternae, both before deflagellation and during
flagellar regeneration. Since SAP126 was sequestered during flagellar
regeneration into secretory vesicles together with newly synthesized scales, it
is concluded that the persistent presence of SAP126 in the trans-Golgi cisternae
during scale biogenesis requires retrograde transport of the protein from the
plasma membrane to the Golgi apparatus.
PMID- 10787049
TI - Leucine aminopeptidases: the ubiquity of LAP-N and the specificity of LAP-A.
AB - The wound-induced leucine aminopeptidase (EC 3.4.11.1) genes, LapA1 and LapA2,
from tomato (Lycopersicon esculentum Mill.) were isolated and characterized. The
genes were organized in a tandem array with approximately 6 kb separating their
coding regions. Quantitation of LapA mRNA levels in conjunction with nuclear run
on experiments indicated that LapA genes were primarily under transcriptional
control after wounding and infection with Pseudomonas syringae pv. tomato. In
contrast, actin genes were down-regulated after pathogen infection. The sequences
of the LapA1 and LapA2 5'-flanking regions were determined and several potential
regulatory motifs were identified. Ribonuclease protection studies revealed that
LapA1 and LapA2 had short 18-bp 5'-untranslated regions (UTR), both genes were
expressed after wounding, and LapA1 mRNAs were 3.3-fold more abundant than LapA2
transcripts. While the region surrounding LapA1 was conserved, the 3'-UTRs and 3'
flanking regions of LapA2 had diverged in two inbred tomato lines. The
accumulation of LapA mRNAs and of LAP-A (acidic pI), LAP-N (neutral pI) and LAP
related proteins were examined in two monocot and five dicot species. The LAP-N
and 66- and 77-kDa LAP-related proteins were detected in healthy and wounded
leaves of all plants examined. The LAP-A proteins were only detected in
nightshade and their accumulation was distinct from that observed in tomato.
PMID- 10787050
TI - A barley gene (rsh1) encoding a ribonuclease S-like homologue specifically
expressed in young light-grown leaves.
AB - A group of frequent cDNA clones from a young-leaf cDNA library was found to code
for a homologue of S-ribonucleases (S-RNases) involved in gametophytic
incompatibility and the so-called S-like RNases active in flowers and in
vegetative tissues. The derived amino acid sequence starts with a signal peptide
and has a 27-amino-acid C-terminal extension of unknown function. The barley
(Hordeum vulgare L.) gene, rsh1 (for RNase S-like homologue) corresponding to the
cDNA clones was isolated. The gene has three introns and the position of one
intron corresponds to the site of the single, small intron in the S-RNase genes.
The deduced amino acid sequence of mature RSH1 shares 35% identical and 58%
similar amino acid residues with an S-like RNase from tomato, RNase LE. However,
two active-site histidine residues, conserved between all S and S-like RNases are
replaced by serine residues in RSH1. The new barley RNase S-like homologue is
clearly related to the family of active RNases but is probably not active as an
RNase. Sequences from the same class of presumably inactive RNases have been
recorded in maize, rice and sorghum. The barley gene is exclusively expressed in
young leaf tissue and is substantially induced by light.
PMID- 10787051
TI - Inhibitors of the carrier-mediated influx of auxin in suspension-cultured tobacco
cells.
AB - Active auxin transport in plant cells is catalyzed by two carriers working in
opposite directions at the plasma membrane, the influx and efflux carriers. A
role for the efflux carrier in polar auxin transport (PAT) in plants has been
shown from studies using phytotropins. Phytotropins have been invaluable in
demonstrating that PAT is essential to ensure polarized and coordinated growth
and to provide plants with the capacity to respond to environmental stimuli.
However, the function of the influx carrier at the whole-plant level is unknown.
Our work aims to identify new auxin-transport inhibitors which could be employed
to investigate its function. Thirty-five aryl and aryloxyalkylcarboxylic acids
were assayed for their ability to perturb the accumulation of 2,4
dichlorophenoxyacetic acid (2,4-D) and naphthalene-1-acetic acid (1-NAA) in
suspension-cultured tobacco (Nicotiana tabacum L.) cells. As 2,4-D and 1-NAA are
preferentially transported by the influx and efflux carriers, respectively,
accumulation experiments utilizing synthetic auxins provide independant
information on the activities of both carriers. The majority (60%) of compounds
half-inhibited the carrier-mediated influx of [14C]2,4-D at concentrations of
less than 10 microM. Most failed to interfere with [3H]NAA efflux, at least in
the short term. Even though they increasingly perturbed auxin efflux when given a
prolonged treatment, several compounds were much better at discriminating between
influx and efflux carrier activities than naphthalene-2-acetic acid which is
commonly employed to investigate influx-carrier properties. Structure-activity
relationships and factors influencing ligand specificity with regard to auxin
carriers are discussed.
PMID- 10787052
TI - Wood formation in poplar: identification, characterization, and seasonal
variation of xylem proteins.
AB - Proteins that are preferentially produced in developing xylem may play a
substantial role in xylogenesis. To reveal the identity of these proteins,
comparative two-dimensional polyacrylamide gel electrophoresis was performed on
young differentiating xylem, mature xylem, and bark of poplar (Populus
trichocarpa Hook. cv. 'Trichobel') harvested at different times of the year. The
most-abundant xylem proteins were identified by microsequence analysis. For 17 of
these proteins a putative function could be assigned based on similarity with
previously characterized proteins, and for 15 out of these corresponding
expressed sequence tags (ESTs) were found in the poplar EST database. The
identified xylem-preferential proteins, defined by comparing the protein patterns
from xylem and bark, were all involved in the phenylpropanoid pathway: two
caffeoyl-coenzyme A O-methyltransferases (CCoAOMT), one phenylcoumaran benzylic
ether reductase (PCBER), one bispecific caffeic acid/5-hydroxyferulic acid O
methyltransferase (COMT), five S-adenosyl-L-methionine synthetases, and one
homologue of glycine hydroxymethyltransferase (GHMT). Remarkably, the biological
function of the two most-abundant xylem-preferential proteins (PCBER and a GHMT
homologue) remains unclear. In addition, several housekeeping enzymes were
identified: two enolases, two glutamine synthetases, one 70-kDa heat-shock
cognate, one calreticulin, and one alpha-tubulin. In comparison to the xylem
preferential proteins, the housekeeping proteins were expressed at significant
levels in the bark as well. Also, several additional protein spots were detected
for CCoAOMT, PCBER, and COMT by immunoblot. Our data show that for the study of
xylogenesis, two-dimensional protein gel comparisons combined with systematic
protein sequencing may yield information complementary to that from EST
sequencing strategies.
PMID- 10787053
TI - Salicylic acid-independent induction of pathogenesis-related gene expression by
fusicoccin.
AB - Treatment of tomato plants (Lycopersicon esculentum Mill.) with fusicoccin (FC),
an activator of the plasma-membrane H+-ATPase which maintains an electrochemical
gradient across the plasma membrane, resulted in a dose-dependent accumulation of
transcripts for intra- and extracellular pathogenesis-related (PR) proteins. The
accumulation of PR protein transcripts was paralleled by an increase in leaf
salicylic acid (SA) content. Transcripts of PR proteins and SA started to
accumulate 3 h after FC treatment. 2-Aminoindan-2-phosphonic acid, an inhibitor
of SA synthesis, was used to assess the role of SA in FC-mediated induction of PR
gene expression. 2-Aminoindan-2-phosphonic acid was found to suppress the
accumulation of SA but not the induction of PR gene expression in response to FC
treatment. Furthermore, in transgenic tobacco plants overexpressing a bacterial
salicylate hydroxylase gene (nahG-tobacco), PR transcripts accumulated after FC
treatment to levels similar to those observed in control tobacco plants. The data
indicate a role for the proton gradient across the plasma membrane in the SA
independent induction of PR gene expression.
PMID- 10787054
TI - Gravity-directed calcium current in germinating spores of Ceratopteris richardii.
AB - Gravity directs the early polar development in single cells of Ceratopteris
richardii Brogn. It acts over a limited period of time during which it
irreversibly determines the axis of the spore cell's development. A self
referencing calcium selective electrode was utilized to record the net movement
of calcium across the cell membrane at different positions around the periphery
of the spore during the period in which gravity orients the polarity of the
spore. A movement of calcium into the cell along the bottom and out of the cell
along the top was detected. This movement was specific, polarized, and strongest
in a direction that opposed the vector of gravity. Treatment with nifedipine, a
calcium-channel blocker, diminished the calcium current and caused the cell to
lose its responsiveness to the orienting influence of gravity. Results shown
suggest that calcium plays a crucial role in the ability of a single cell to
respond to gravity and in the subsequent establishment of its polarity.
PMID- 10787055
TI - Species variation in the intracellular localization of pyruvate, Pi dikinase in
leaves of crassulacean-acid-metabolism plants: an immunogold electron-microscope
study.
AB - In malic enzyme-dependent crassulacean-acid-metabolism (ME-CAM) plants, malic
acid is decarboxylated by NADP-ME and NAD-ME and generates pyruvate with CO2.
Pyruvate is phosphorylated to phosphoenolpyruvate by pyruvate, Pi dikinase (PPDK)
and is then conserved in gluconeogenesis. Although PPDK was considered to be
located in chloroplasts (e.g., Mesembryanthemum crystallinum), it has recently
been found to accumulate in both the chloroplasts and the cytosol in two
Kalanchoe species. In this study, the intracellular localization of PPDK was
investigated in 22 ME-CAM species in 13 genera of 5 families by immunogold
labeling and electron microscopy. This revealed that the pattern of intracellular
localization of PPDK varies among the ME-CAM plants and is divided into three
types: Chlt, in which PPDK accumulates only in the chloroplasts; Cyt-Chlt, in
which PPDK accumulates in both chloroplasts and cytosol; and Cyt, in which PPDK
accumulates predominantly in the cytosol. Members of a particular genus tend to
have a common PPDK-localization type. In the Cactaceae, all species from seven
genera were classified as Cyt. The photosynthetic tissues of all ME-CAM species,
including the Cyt type, had substantial PPDK activity, suggesting that PPDK in
the cytosol is active and probably plays a functional role. In the Chlt species,
NADP-ME activity was relatively greater than NAD-ME activity. In the Cyt-Chlt and
Cyt species, however, either the activity of NAD-ME was higher than that of NADP
ME or they were approximately the same. The species variation in the
intracellular localization of PPDK is discussed in relation to CAM function and
to molecular and phylogenetic aspects.
PMID- 10787056
TI - In vitro biosynthesis of 1,4-beta-galactan attached to rhamnogalacturonan I.
AB - The biosynthesis of galactan was investigated using microsomal membranes isolated
from suspension-cultured cells of potato (Solanum tuberosum L. var. AZY).
Incubation of the microsomal membranes in the presence of UDP-[14C]galactose
resulted in a radioactive product insoluble in 70% methanol. The product released
only [14C]galactose upon acid hydrolysis. Treatment of the product with
Aspergillus niger endo-1,4-beta-galactanase released 65-70% of the radioactivity
to a 70%-methanol-soluble fraction. To a minor extent, [14C]galactose was also
incorporated into proteins, however these galactoproteins were not a substrate
for Aspergillus niger endo-1,4-beta-galactanase. Thus, the majority of the 14C
labelled product was 1,4-beta-galactan. Compounds released by the endo-1,4-beta
galactanase treatment were mainly [14C]galactose and [14C]galactobiose,
indicating that the synthesized 1,4-beta-galactan was longer than a trimer. In
vitro synthesis of 1,4-beta-galactan was most active with 6-d-old cells, which
are in the middle of the linear growth phase. The optimal synthesis occurred at
pH 6.0 in the presence of 7.5 mM Mn2+. Aspergillus aculeatus rhamnogalacturonase
A digested at least 50% of the labelled product to smaller fragments of approx.
14 kDa, suggesting that the synthesized [14C]galactan was attached to the
endogenous rhamnogalacturonan I. When rhamnogalacturonase A digests of the
labelled product were subsequently treated with endo-1,4-beta-galactanase,
radioactivity was not only found as [14C]galactose or [14C]galactobiose but also
as larger fragments. The larger fragments were likely the [14C]galactose or
[14C]galactobiose still attached to the rhamnogalacturonan backbone since
treatment with beta-galactosidase together with endo-1,4-beta-galactanase
digested all radioactivity to the fraction eluting as [14C]galactose. The data
indicate that the majority of the [14C]galactan was attached directly to the
rhamnose residues in rhamnogalacturonan I. Thus, isolated microsomal membranes
contain enzyme activities to both initiate and elongate 1,4-beta-galactan
sidechains in the endogenous pectic rhamnogalacturonan I.
PMID- 10787057
TI - Localization of pectins in the pollen tube wall of Ornithogalum virens L. Does
the pattern of pectin distribution depend on the growth rate of the pollen tube?
AB - Monoclonal antibodies that recognize pectins were used for the localization of
esterified (JIM7) and acidic, unesterified (JIM5) forms of pectin in pollen tube
walls of Ornithogalum virens L. (x = n = 3). The results indicated that the
distribution of the two forms of pectin in the pollen tube wall depended on the
medium (liquid or solid) used for pollen germination. In pollen tubes grown in
the liquid medium, the localization of JIM7 was limited to the very tip of the
pollen tube, whereas the localization of JIM5 indicated a uniform distribution of
unesterified pectins in the very tip of the tube and along the subapical parts of
the tube wall. In tubes germinated on the medium stabilized with agar (1-2%) the
localization of JIM7 and JIM5 indicated the presence of both forms of pectin in
the tube tip and along the whole length of the pollen tube wall in a ring-like
pattern. Thus, the localization of esterified pectins in the sub-apical part of
the pollen tube wall, below the apex of the tube, is described for the first
time. Measurements of the growth rates of pollen tubes growing on the two types
of medium indicated that oscillations in tube growth rate occur but these do not
coincide with the pattern of pectin distribution in the tube wall. Our results
complement the previous data obtained for the localization of JIM5 and JIM7 in
pollen tube walls of other plant species. (Y.-Q. Li et al. 1994, Sex Plant Reprod
7: 145-150) and provide new insight into an understanding of the construction of
the pollen tube wall and the physiology of pollen grain germination.
PMID- 10787058
TI - Hormonal regulation of fruitlet abscission induced by carbohydrate shortage in
citrus.
AB - The hormonal signals controlling fruitlet abscission induced by sugar shortage in
citrus were identified in Satsuma mandarin, Citrus unshiu (Mak.) Marc, cv.
Clausellina and cv. Okitsu. Sugar supply, hormonal responses and fruitlet
abscission were manipulated through full, partial or selective leaf removals at
anthesis and thereafter. In developing fruitlets, defoliations reduced soluble
sugars (up to 98%), but did not induce nitrogen and water deficiencies.
Defoliation-induced abscission was preceded by rises (up to 20-fold) in the
levels of abscisic acid (ABA) and 1-aminocyclopropane-1-carboxylic acid (ACC) in
fruitlets. Applications to defoliated plants showed that ABA increased ACC levels
(2-fold) and accelerated fruitlet abscission, whereas norflurazon and 2
aminoethoxyvinyl glycine reduced ACC (up to 65%) and fruitlet abscission (up to
40%). Only the full defoliation treatment reduced endogenous gibberellin A1 (4
fold), whereas exogenous gibberellins had no effect on abscission. The data
indicate that fruitlet abscission induced by carbon shortage in citrus is
regulated by ABA and ACC originating in the fruits, while gibberellins are
apparently implicated in the maintenance of growth. In this system, ABA may act
as a sensor of the intensity of the nutrient shortage that modulates the levels
of ACC and ethylene, the activator of abscission. This proposal identifies ABA
and ACC as components of the self-regulatory mechanism that adjusts fruit load to
carbon supply, and offers a physiological basis for the photoassimilate
competition-induced abscission occurring under natural conditions.
PMID- 10787059
TI - Expression pattern of (+)-delta-cadinene synthase genes and biosynthesis of
sesquiterpene aldehydes in plants of Gossypium arboreum L.
AB - The cotton (+)-delta-cadinene synthase, a sesquiterpene cyclase, is encoded by a
complex gene family which, based on homology, can be divided into two
subfamilies: cad1-A and cad1-C. Southern blots revealed several members of the
cad1-C subfamily, and a single member of the cad1-A subfamily, in the diploid
Gossypium arboreum genome. One of the cad1-C genes, cad1-C3, was isolated from
this species. According to reverse transcriptase-polymerase chain reaction,
transcripts of both cad1-C and cad1-A genes appeared in roots from the second day
post germination and in 1-d-old cotyledons, whereas the transcription levels were
too low to be detected in the hypocotyls. Initially, sesquiterpene cyclase
activities were found to be high in the seedlings, then dropped in aerial organs
but increased in roots during development. Sesquiterpene aldehyde contents
followed the same pattern. In fully developed plants, the transcripts of cad1-C
were detected in stems, leaves and pericarps, as well as in the sepals and petals
3 d before anthesis, but not at the day of anthesis. In contrast, cad1-A
transcripts were not detected in any of these aerial organs. The sesquiterpene
aldehyde contents increased in petals but decreased in sepals after anthesis.
Treatment of G. arboreum stems with a Verticillium dahliae elicitor-preparation
activated cad1-A transcription, but a significant level of cad1-C transcripts was
detected both before and after elicitation. In G. hirsutum cv. GL-5, a glandless
cultivar, the cad1-C gene was activated by the same fungal elicitor, followed by
the synthesis of the sesquiterpene cyclase, and accumulation of sesquiterpene
aldehydes. The cad1 gene expression during development and in response to
elicitation, as well as the spatial and temporal pattern of sesquiterpene
biosynthesis, constitute a chemical defense machinery in cotton plants.
PMID- 10787060
TI - Arginine degradation by arginase in mitochondria of soybean seedling cotyledons.
AB - Arginase (EC 3.5.3.1) localization was studied in soybean (Glycine max L.)
seedling cotyledons. Subcellular fractionation in a discontinuous Percoll
gradient showed that arginase was localized in the mitochondrion. Arginine (Arg)
uptake by mitochondria was demonstrated by co-sedimentation of [3H]Arg-derived
label and the mitochondrial marker enzyme cytochrome c oxidase. Arginine uptake
was complete in about 10 min. Since detergent but not NaCl released most label,
we conclude that Arg was taken up and not bound to the organellar surface.
Arginine transport was not saturable, at least up to 20 mM. Basic amino acids
were the best inhibitors of Arg uptake. The uncoupler 2,4-dinitrophenol did not
inhibit Arg uptake. At least 30% of L-[guanido-14C]Arg taken up by mitochondria
was degraded by arginase in seedling cotyledons, while little or no degradation
was detected in mitochondria from developing embryos, even though the Arg uptake
level was similar in both mitochondrial preparations. These results are
consistent with our previously reported pattern of arginase expression and urea
accumulation during embryo development and seed germination (A. Goldraij and J.C.
Polacco, 1999, Plant Physiol. 119: 297-303). The lack of Arg degradation allows
developing embryos to conserve Arg, the main N-reserve amino acid utilized by
germinating soybean.
PMID- 10787061
TI - O-Acetylation of plant cell wall polysaccharides: identification and partial
characterization of a rhamnogalacturonan O-acetyl-transferase from potato
suspension-cultured cells.
AB - A microsomal preparation from suspension-cultured potato stem cells (Solanum
tuberosum L. cv. AZY) was incubated with [14C]acetyl-CoA resulting in a
precipitable radiolabeled product. Analysis of the product revealed that it
consisted mostly of acetylated proteins and cell wall polysaccharides, including
xyloglucan, homogalacturonan and rhamnogalacturonan I. Thus, acetyl-CoA is a
donor-substrate for the O-acetylation of wall polysaccharides. A
rhamnogalacturonan acetylesterase was used to develop an assay to measure and
characterize rhamnogalacturonan O-acetyl transferase activity in the microsomal
preparation. Using this assay, it was shown that the transferase activity was
highest during the linear growth phase of the cells, had a pH-optimum at pH 7.0,
a temperature optimum at 30 degrees C, an apparent Km of 35 microM and an
apparent Vmax of 0.9 pkat per mg protein. Further analysis of the radiolabeled
acetylated product revealed that it had a molecular mass > 500 kDa.
PMID- 10787062
TI - Role of extensin peroxidase in tomato (Lycopersicon esculentum Mill.) seedling
growth.
AB - It is proposed that inhibition of extensin peroxidase activity leads to a less
rigid cell wall and thus promotes cell expansion and plant growth. A low
molecular-weight inhibitor derived from the cell walls of suspension-cultured
tomato cells was found to completely inhibit extensin peroxidase-mediated
extensin cross-linking in vitro at a concentration of 260 microg/ml. The
inhibitor had no effect upon guaiacol oxidation catalyzed by extensin peroxidase
or horseradish peroxidase. We have demonstrated that the light-irradiated
inhibition of plant growth may be partially offset by inhibition of endogenous
extensin peroxidase activity. Overall plant growth was enhanced by up to 15% in
the presence of inhibitor relative to control plants. Inhibitor-treated and
illuminated tomato hypocotyls grew up to 15% taller than untreated controls. The
inhibitor had no effect upon etiolated plants over a 15-d period, suggesting that
only low levels of peroxidase-mediated cross-linking can be found in the cell
walls of etiolated plants. SDS-PAGE/Western blots of ionically bound protein from
both etiolated and illuminated hypocotyls identified a doublet at 57/58.5 kDa
which is immunoreactive with antibodies raised to tomato extensin peroxidase.
Levels of the 58.5-kDa protein, determined by SDS-PAGE, were at least threefold
higher in illuminated tomato hypocotyls than in etiolated hypocotyls. Three fold
higher levels of extensin peroxidase, elevated in-vitro extensin cross-linking
activity and 15% higher levels of cross-linked, non-extractable extensin were
observed in illuminated tomato hypocotyls compared with etiolated tomato
hypocotyls. This suggests that white-light inhibition of tomato hypocotyl growth
appears to be mediated, at least partially, by deposition of cell wall extensin,
a process regulated by Mr-58,500 extensin peroxidase. Our results indicate that
the contribution of peroxidase-mediated extensin deposition to plant cell wall
architecture may have an important role in plant growth.
PMID- 10787063
TI - Mutations causing defects in the biosynthesis and response to gibberellins,
abscisic acid and phytochrome B do not inhibit vernalization in Arabidopsis fca
1.
AB - The roles of gibberellins, abscisic acid and phytochrome B in the vernalization
response were investigated by combining mutations causing defects in their
biosynthesis and response with the Arabidopsis thaliana (L.) Heynh. fca-1
mutation. The fca-1 mutation confers a very late-flowering phenotype which can be
reversed to wild-type flowering if the seedlings are vernalized. Vernalization
was unaffected in ga1-3, gai, abi1-1, abi2-1, abi3-1 and phyB-1 backgrounds,
suggesting that gibberellin action mediated via GA1 and GAI, abscisic acid action
mediated through ABI1 and ABI2, and phytochrome B, function independently of
vernalization. However, the mutations did interact with fca-1 to change flowering
time in the absence of vernalization. The abi1 fca-1 and abi2 fca-1 double
mutants flowered earlier than fca-1 implying a role for abscisic acid in floral
repression. Combination of ga1-3 or gai with fca-1 unexpectedly resulted in
opposite interactions, with gai partially suppressing the late flowering of fca
1.
PMID- 10787064
TI - Isolation and characterization of two acyl-CoA-binding proteins from
proembryogenic masses of Digitalis lanata Ehrh.
AB - Two acyl-CoA-binding-protein (ACBP) isoforms were isolated from proembryogenic
masses of Digitalis lanata Ehrh. by column chromatography and preparative HPLC.
The ACBPs had molecular masses of 9926 and 9997 Da, respectively. Partial
sequence data indicated high similarity to each other and to ACBPs of other plant
species such as Ricinus communis, Brassica napus and Arabidopsis thaliana. The
isolated ACBPs bound palmitoyl-CoA with high affinity as determined by
isoelectric-point shift.
PMID- 10787065
TI - Purification and cloning of an arabinogalactan-protein from xylem of loblolly
pine.
AB - An arabinogalactan-protein (AGP) was purified from differentiating xylem of
loblolly pine (Pinus taeda L.) and the N-terminal sequence used to identify a
cDNA clone. The protein, PtaAGP3, was not coded for by any previously identified
AGP-like genes. Moreover, PtaAGP3 was abundantly and preferentially expressed in
differentiating xylem. The encoded protein contains four domains, a signal
peptide, a cleaved hydrophilic region, a region rich in serine, alanine, and
proline/hydroxyproline, and a hydrophobic C-terminus. It is postulated to contain
a GPI (glycosylphosphatidylinositol) anchor site. If the protein is cleaved at
the putative GPI anchor site, as has been observed in other classical AGPs, all
but the Ser-Ala-Pro/Hyp-rich domain may be missing from the mature protein. Xylem
specific AGPs are hypothesized to be involved in xylem development.
PMID- 10787066
TI - Release of endotoxin-binding proteins during major elective surgery: role of
soluble CD14 in phagocytic activation.
AB - Our previous study demonstrated that soluble CD14 (sCD14) modulates the biologic
activity of circulating endotoxin, which appears after surgery. In this study, we
examined the behavior of endotoxin-binding proteins, such as sCD14,
lipopolysaccharide-binding protein (LBP), and bactericidal/permeability
increasing protein (BPI), in patients' plasma after major abdominal surgery and
the phagocytic secretion of sCD14 from peripheral blood mononuclear cells (PBMCs)
throughout the observation period. In a prospective study, 15 patients undergoing
major abdominal surgery (gastrectomy, n = 3; pancreatectomy, n = 10: colectomy, n
= 2) were involved in this study. The endotoxin-binding proteins were
perioperatively (preoperatively; postoperative hour 6; days 1, 2, 3, 4, 5, 7, and
10) measured by an enzyme-linked immunosorbent assay (ELISA). To exclude the
hemodilution effect of samples, each parameter was corrected by dividing the
respective value by the albumin concentration. The phagocytic activity at each
time point was tested as an ex vivo sCD14 secretion from PBMCs in the presence
and absence of exogenously added endotoxin, Escherichia coli 055B5 (1 ng/ml).
Significant endotoxemia (0.35 +/- 0.13 EU/ml; p < 0.05) was observed 6 hours
after the beginning of surgery. The sCD14/albumin value rapidly increased at 6
hours after surgery, peaked on day 1, and sequentially declined, whereas the
BPI/albumin and LBP/albumin ratios increased more gradually and peaked on day 2.
The secretion of sCD14 from 2 x 10(6) PBMCs was significantly enhanced from 6
hours after operation. The increased plasma level of sCD14 may be explained by
the parallel-enhanced sCD14 PBMC production. Activated secretion of these
endotoxin-binding proteins may play a role in regulating the biologic activity of
circulating endotoxin.
PMID- 10787067
TI - Does hyperthermia induce peritoneal damage in continuous hyperthermic peritoneal
perfusion?
AB - To investigate the mechanisms of the peritoneal damage induced by continuous
hyperthermic peritoneal perfusion (CHPP), protein and fluid loss during and after
CHPP and continuous normothermic peritoneal perfusion (CNPP) was studied. Sixteen
patients with advanced gastric cancer underwent peritoneal perfusion therapy with
saline solution containing 150 to 300 mg cisplatin and 30 to 60 mg mitomycin C
for 60 minutes. The temperature in Douglas' pouch was maintained at 42.0 degrees
C in the CHPP group (n = 9) and 37.0 degrees C in the CNPP group (n = 7) during
perfusion. No statistical differences were found in patients' characteristics
between the groups except the maximum temperature in Douglas' pouch during
perfusion (41.6 degrees +/- 0.4 degrees C and 37.6 degrees +/- 0.4 degrees C in
CHPP and CNPP groups, respectively, p < 0.05). The amount of protein lost into
the perfusate was 0.35 +/- 0.22 g/kg body weight in the CHPP group and 0.37 +/-
0.19 g/kg in the CNPP group, showing no significant difference. On the day of
surgery, there was no significant difference in the amount of protein and fluid
lost through the abdominal drains between the CHPP group (27.9 +/- 24.6 mg/kg/hr
and 0.94 +/- 0.63 ml/kg/hr, respectively) and the CNPP group (25.9 +/- 8.6
mg/kg/hr and 1.03 +/- 0.31 ml/kg/hr, respectively). We could not find any
significant differences in postoperative protein and fluid loss between the
groups on the following 3 days either. We conclude that the peritoneal damage by
CHPP is not caused by the hyperthermia but by the peritoneal perfusion with
saline solution containing anticancer drugs.
PMID- 10787068
TI - Preincisional dextromethorphan treatment for postoperative pain management after
upper abdominal surgery.
AB - Previous studies showed that ketamine, an N-methyl-D-aspartate (NMDA) receptor
antagonist, provides a preemptive analgesic effect and preemptive analgesia
improves postoperative pain management. The aim of this study was to examine
whether premedication with dextromethorphan (DM) improves postoperative pain
management after upper abdominal surgery. Sixty (American Society of
Anesthesiologists class 1 and 2 of either gender) patients scheduled for upper
abdominal surgery were included in the study. Patients were randomly assigned to
one of four groups: control, DM-10, DM-20, and DM-40. In the control group,
chlorpheniramine maleate (CPM, 20 mg) was injected immediately before induction
of anesthesia intramuscularly (IM). In the DM-10, DM-20, and DM-40 groups,
patients were premedicated with DM 10 mg, 20 mg, and 40 mg IM, respectively.
After operation, patient-controlled analgesia (PCA) with morphine was given for
pain relief. The time to the first PCA trigger, morphine consumption, pain
scores, and analgesic-related side effects were recorded at 1, 2, 4, 24, 48, and
72 hours after surgery. The time to first PCA trigger for the control group was
17.8 +/- 1.4 minutes, for group DM-10 20.2 +/- 1.6 minutes, for group DM-20 32.4
+/- 1.9 minutes, and for DM-40 77.9 +/- 6.5 minutes. The morphine delivered and
PCA triggering frequency were 5.5 +/- 0.5/11.3 +/- 0.8 times for the controls,
5.5 +/- 0.4/ 14.1 +/- 1.3 times for DM-10, 3.1 +/- 0.3/6.3 +/- 1.2 times for DM
20, and 0.2 +/- 0.1/0.3 +/- 0.2 times for DM-40 during the first hour after
operation. For the first day, the figures are 19.9 +/- 1.2/23.9 +/- 1.4 for the
controls, 15.6 +/- 1.2/17.3 +/- 2.4 for DM-10, 12.6 +/- 0.7/15.9 +/- 1.6 for DM
20, and 5.0 +/- 0.21/5.6 +/- 0.9 for DM-40. On the first day, the cough pain
scores were 6.67 +/- 0.23, 6.53 +/- 0.16, 6.67 +/- 0.23, and 5.73 +/- 0.18 for
the controls, DM-10, DM-20, and DM-40 groups, respectively. All data showed dose
dependent better pain relief in DM-premedicated patients. We conclude that DM
premedication offers preemptive analgesia and reduces postoperative pain and
morphine requirement.
PMID- 10787069
TI - Topical formalin for management of bleeding malignant ulcers.
AB - Hemorrhage, an infrequent but serious complication of malignant ulceration, can
be difficult to manage. Although many methods exist for treatment, none is wholly
satisfactory. The use of topical formalin was studied in a group of patients with
bleeding from malignant ulcers, and the results show that the agent achieved
control of bleeding in 86% of the patients after two applications. There were no
significant complications arising from the treatment. Topical formalin is a safe,
inexpensive, effective agent for control of bleeding from malignant ulcers.
PMID- 10787070
TI - Intraperitoneal gossypibomas: the need to count sponges.
AB - Intraperitoneal forgotten foreign bodies are prone to create adhesions and to
encapsulate, or to provoke an exudative response, with or without accompanying
bacterial infection. Often a process of self-extrusion is initiated. This is also
true for gossypibomas, retained surgical sponges. Presentation is possible as a
pseudotumoral, occlusive, or septic syndrome; several cases, however, have
remained asymptomatic for as long as several decades. Ultrasonography and
radiology (especially computed tomography) contribute significantly to the
detection of gossypibomas; magnetic resonance imaging is a less used technique.
Detection by plain radiography is difficult. Ultrasonography demonstrates a
hyperreflective mass with hypoechoic rim and a strong posterior shadow. Computed
tomography shows a well defined mass with internal heterogeneous densities.
Therapy consists of operative removal of the foreign body in association with
resolving its complications. Adding a series of five cases to the existing
literature reports, the fate of intraperitoneal forgotten surgical sponges is
reviewed.
PMID- 10787071
TI - Ultrastructural alterations of polytetrafluoroethylene prostheses implanted in
abdominal wall provoked by infection: clinical and experimental study.
AB - Infection of an expanded polytetrafluoroethylene (ePTFE) prosthesis after implant
is a major drawback of its use in current clinical practice. The aim of the
present study was to compare the behavior of such prostheses implanted into New
Zealand rabbits with that of prostheses infected after clinical implant.
Experimental implants of ePTFE Soft Tissue Patch were performed to repair defects
(7 x 5 cm) created in the abdominal wall of 10 rabbits. Prior to implant the
prostheses were contaminated with Staphylococcus aureus. Five animals implanted
with noncontaminated ePTFE prostheses served as controls. All the animals were
sacrificed at 30 days after implant. For the clinical study, specimens were taken
from three ePTFE implants that had been found to be infected after intervention.
The clinical and experimental implant specimens were processed for light
microscopy and scanning electron microscopy. Macroscopic and microscopic
examination of experimental and clinical implants revealed alterations to the
ePTFE structure, such as areas of fragmentation, fracture lines, and detachment
of fine layers of ePTFE that harbored numerous Staphylococcus colonies. Neoformed
tissue around contaminated implants was arranged more loosely, and on occasion
large spaces between fibers gave rise to an "unknitted" appearance with respect
to the control implants. It may be concluded that microporous ePTFE prostheses
show similar behavior following experimental or clinical implant in the presence
of infection. Irreversible changes to the structure of the prosthesis are
produced owing to colonization of the biomaterial by microorganisms, which in
most cases necessitates total replacement of the prosthesis.
PMID- 10787073
TI - Angiographic embolization for intraperitoneal and retroperitoneal injuries.
AB - Angiographic embolization (AE) has been used extensively for bleeding control
after injuries to the face and neck. Its role in abdominal trauma requires
further exploration. We reviewed the medical records of 137 consecutive patients
who underwent angiography with the intent to embolize bleeding sites within the
abdomen. Of them, 97 (71%) had blunt and 40 (29%) had penetrating trauma. AE was
performed for hemorrhage associated with pelvic fractures (97 patients), liver
lacerations (n = 26), renal lacerations (n = 12), splenic lacerations (n = 5),
other injuries (n = 9), and multiple injuries (n = 12). On angiography, 102
patients were found to have bleeding sites and underwent AE, with angiographic
and clinical bleeding control in 93 (91%). The rate of successful hemostasis by
AE was identical in blunt and penetrating trauma patients. There was no major
morbidity after AE. No factors predicted patients with a high likelihood to have
a positive angiogram. Patients who had AE before or after a period of attempted
hemodynamic stabilization in the intensive care unit were no different with
respect to hemodynamic parameters immediately before AE or effectiveness of AE
for bleeding control. AE is a safe and effective method for controlling bleeding
after blunt and penetrating intra- and retroperitoneal injuries. Early AE may be
used in selected patients as a front-line therapeutic intervention that offers
expeditious hemostasis and prevents delays in definitive bleeding control.
PMID- 10787072
TI - Complicated enterocutaneous fistulas: failure of octreotide to improve healing.
AB - Octreotide has been promoted as a potential aid during closure of enterocutaneous
fistulas (ECFs) on the basis of clinical and experimental evidence that it can
reduce gastrointestinal secretions. We retrospectively reviewed the records of
patients admitted with ECF to our tertiary referral center to ascertain whether
use of octreotide affected fistula duration, length of hospitalization, closure
rate, and morbidity. Of 60 patients diagnosed and treated for ECF over a 4-year
period, 13 underwent a therapeutic trial with octreotide. Thirteen patients from
the group who did not receive octreotide were matched by cause, location, and
output of the fistula, age, and primary diagnosis to the treatment group.
Octreotide was administered in therapeutic dosage for a mean course of 57 +/- 29
days, resulting in a substantial acute decrease (84.7 +/- 4.8%) in fistula
output. Prolonged therapy nevertheless failed to affect the outcome parameters
studied, particularly fistula duration, spontaneous closure rate, and length of
hospitalization. There was a significantly higher incidence of septic and
thrombotic complications associated with octreotide use. In this patient
population with complicated ECFs, use of octreotide showed no benefit and was
associated with increased morbidity.
PMID- 10787074
TI - Axillary lymph nodes in breast cancer: is size related to metastatic involvement?
AB - Usually when using imaging procedures, such as axillary mammography or
ultrasonography, a cutoff level of 5 mm for lymph node size is postulated to be
not only the limit of lymph node visibility but also a sign of metastatic
involvement. The aim of this study was to evaluate whether this assumption, used
as a basic hypothesis in many reports, is true. A series of 72 axillary specimens
from 71 breast carcinoma patients operated at the university hospital of Vienna
were analyzed. A comparison of histologically noninvolved axillary specimens with
those showing metastatic involvement revealed that the two groups did not differ
significantly according to the number or size of lymph nodes per axilla. For
lymph nodes <5 mm the probability of being metastatically involved was still 10%.
Enlarged lymph nodes (5-20 mm) had a slightly higher risk of being malignant
(20%). In contrast, the probability of metastatic involvement for lymph nodes >20
mm was only 40%. We suggest that many reports dealing with the prediction of
malignancy in axillary lymph nodes may have used misleading basic assumptions, so
the results of these studies must be viewed critically.
PMID- 10787075
TI - Prospective case-controlled trial of adjuvant chemotherapy after resection of
hepatocellular carcinoma.
AB - Recurrence of hepatocellular carcinoma (HCC) after curative hepatic resection is
frequent and is an important factor adversely influencing long-term survival. The
role of postoperative chemotherapy in the reduction of tumor recurrence rate is
still controversial. During the period of 1992-1995 a series of 49 patients who
underwent curative resection of HCC and had at least one risk factor of tumor
recurrence were followed in this prospective study. Patients were allocated to
adjuvant chemotherapy and control groups. Twenty-four patients received a
combination of low dose intravenous epirubicin (20 mg/m2) and mitomycin (5 mg)
monthly for seven courses starting 5 to 6 weeks after surgery. Twenty-five
patients had no adjuvant treatment. The disease-free and overall survivals were
compared for the two groups. A total of 154 courses of chemotherapy were given to
the 24 patients. The chemotherapy-related side effects were mild and tolerable
with no mortality. At a median follow-up of 39 months (range 9-71 months), 9
patients in the adjuvant chemotherapy group and 16 patients in the control group
developed tumor recurrence. The respective 1-, 2-, 3-, and 5-year disease-free
survival rates were 75%, 67%, 63%, and 63% for patients in the adjuvant
chemotherapy group and 68%, 42%, 37%, and 32% for patients in the control group
(p = 0.0575). The 1-, 2-, 3-, and 5-year overall survival rates were 100%, 96%,
77%, and 72% in the adjuvant chemotherapy group and 92%, 67%, 63%, and 51% in the
control group (p = 0.0746). In conclusion, postoperative adjuvant chemotherapy
using the present regimen has a tendency to reduce tumor recurrence rate and may
improve long-term survival for high risk patients.
PMID- 10787076
TI - Intraoperative parathormone measurement in patients with multiple endocrine
neoplasia type I syndrome and hyperparathyroidism.
AB - Total or subtotal parathyroidectomy is considered the treatment of choice for
multiple endocrine neoplasia type I (MEN-I)-associated primary
hyperparathyroidism (HPT). However, persistent or recurrent HPT is frequently
observed. The development of a rapid two-site immunoradiometric assay (IRMA)
method for measuring intact parathormone (PTH) has provided a valuable tool for
recognizing possible surgical failures. Our experience includes 16 MEN-I patients
(10 females, 6 males) of mean age 35.5 years operated on between 1990 and 1996.
Total parathyroidectomy (TPTX) with autotransplantation of parathyroid tissue was
the standard treatment. Blood samples for PTH measurement were drawn at the
induction of anesthesia (basal value), 10 and 20 minutes after the removal of
each gland, and 60 minutes after TPTX. Rapid PTH measurement, which required only
15 minutes of incubation at 37 degrees C, showed a highly significant correlation
(p < 0.0001) with the standard method. Circulating PTH levels exhibited a
stepwise decrease during TPTX, reaching a mean value of 22.3% of the baseline 20
minutes after removal of the last gland. Two patients showed a prompt decrease of
PTH after removal of the single enlarged gland, featuring the kinetics observed
in the adenomas. One of these two patients was successfully treated with more
conservative surgery. None of the patients showed persistence or recurrence of
HPT. In our experience, intraoperative measurement of PTH seems to be a valuable
adjunct in both the diagnosis of multiglandular involvement and the prediction of
surgical treatment in patients with primary parathyroid hyperplasia.
PMID- 10787077
TI - Outcome after surgery for primary hyperparathyroidism: ten-year prospective
follow-up study.
AB - Clinical outcome after surgery for primary hyperparathyroidism was evaluated in a
prospective long-term, follow-up study. From August 1, 1987 to August 31, 1998 a
total of 360 patients were prospectively investigated and included in a follow-up
study. All patients underwent follow-up examinations at regular surveillance
intervals. The postoperative course is known for 94.5% of all patients. Follow-up
was 1 month to 10 years (median 24 months; mean 34.5 +/- 29.8 months).
Asymptomatic primary hyperparathyroidism was rare (6%), and its true frequency
could be confirmed only postoperatively because some of the patients were unaware
of mild symptoms of hypercalcemic syndrome prior to surgery. Surgical cure was
obtained in 97.7% of patients after initial cervical exploration; and successful
parathyroidectomy provided long-term relief of symptoms. Within 2 years
postoperatively, 84% of the patients recovered fully from hypercalcemic syndrome:
in 58% of these patients recovery occurred within the first month after surgery.
Skeletal symptoms persisted in 24% of patients 2 years postoperatively. To date
no patient has developed recurrence of primary hyperparathyroidism. During follow
up in our study population mortality was significantly higher than the expected
mortality risk for the German population as a whole (p = 0.00024). The present
prospective follow-up study yielded conclusive outcome research data after
operative therapy for primary hyperparathyroidism. The high cure rate and low
morbidity, as well as the increased mortality, in our study population during
follow-up after successful operative therapy for the disease emphasize the
importance of early diagnosis and early surgical treatment for primary
hyperparathyroidism, even in the absence of manifest symptoms.
PMID- 10787078
TI - Palpatory method used to identify the recurrent laryngeal nerve during
thyroidectomy.
AB - The major complication of thyroid surgery, occurring in 1% to 6% of cases, is
injury to the recurrent laryngeal nerve (RLN). A simple method to identify the
RLN during thyroid surgery is described by the authors. It consists in palpation
of the nerve caudally to the inferior pole of the thyroid, after the nerve has
been made taut by the upward and medial traction of the thyroid gland. This
method was used on 47 human cadavers and 45 patients with benign thyroid
diseases. It made it possible to identify the RLN in all of the cadavers and 52
of the 55 identifications during 45 thyroidectomies (in 10 total thyroidectomies
the identification was bilateral). Laryngeal motility was normal in all patients
at postoperative laryngoscopy. Using the palpation before dissection in the
region of the inferior thyroid artery, the traditional viewing method became
easier and safer, reducing the risk of injury where it is most likely to occur to
the nerve.
PMID- 10787079
TI - Comparison of the hemodynamic parameters of open and laparoscopic adrenalectomy
for pheochromocytoma.
AB - Laparoscopic adrenalectomy has gained widespread popularity for treating a
variety of adrenal disorders including pheochromocytoma, but the effects of
pneumoperitoneum on the hemodynamics of patients with catecholamine-secreting
tumors are poorly understood. The goal of this study was to compare the effects
of carbon dioxide pneumoperitoneum and tumor manipulation on the hemodynamic
parameters in two groups of patients with sporadic pheochromocytomas less than 7
cm in size. Group 1 patients (n = 11) underwent lateral transabdominal
laparoscopic adrenalectomy, and group 2 (n = 11) underwent adrenalectomy by the
open anterior approach. The mean follow-up was 37 months in group 1 (range 26-51
months) and 52 months in group 2 (range 27-72 months). All patients undergoing
laparoscopic adrenalectomy experienced intraoperative hypertension (blood
pressure > or = 200/90 mmHg), as did 73% with the open approach, but the
difference was not significantly different. Intraoperative hypotension (systolic
blood pressure < 80 mmHg) occurred in four group 1 patients compared to six
patients in group 2. Mean arterial pressure, central venous pressure, and
pulmonary capillary wedge pressure were significantly higher in group 1 patients
prior to tumor excision, but there was no difference in pulse, cardiac index, or
left ventricle work index at any point during the procedure. There were no
conversions or complications in the laparoscopic group; one patient in group 2
developed an incisional hernia. Although laparoscopic adrenalectomy for
pheochromocytoma is associated with a greater increase in mean arterial pressure,
central venous pressure, and pulmonary capillary wedge pressure, the creation of
pneumoperitoneum does not significantly change the cardiac index or left
ventricle work index. Carbon dioxide pneumoperitoneum is well tolerated in
patients with pheochromocytoma.
PMID- 10787080
TI - Natural course of adrenal incidentalomas: seven-year follow-up study.
AB - Most adrenal incidentalomas are nonfunctioning cortical adenomas that do not
require surgery. Operative treatment is indicated if the incidentaloma has
malignant features as seen during the radiologic workup, is hormonally active, or
grows during follow-up. A conservative attitude is justified in asymptomatic
patients if we know that the natural course of these tumors is not
disadvantageous. We followed a group of patients treated by observation to
determine the natural course of adrenal incidentalomas. Altogether 30
incidentalomas in 27 patients were detected in the Helsinki University Central
Hospital from June 1981 through December 1992 and were re-examined during 1997.
The patients were evaluated clinically, and hormonal testing was done by
performing a 1-mg overnight dexamethasone suppression test; the next day we
measured the 24-hour urinary excretion of vanillylmandelic acid, metanephrines
and normetanephrines, and serum potassium. Magnetic resonance imaging (MRI) was
used to determine the size of the tumor. If the patient had died during the
follow-up period, the causes of death from the death certificates and autopsy
reports were reviewed. The mean follow-up was 7 years. Nine patients had died,
with none of deaths related to the incidentaloma. Sixteen patients were evaluated
clinically and by the basic hormonal tests and MRI; none showed any signs of
hormonal activity or features of malignancy. Two patients did not want to be
reexamined but stated that they were asymptomatic. This follow-up study supports
the conclusion that conservative therapy is justified because the growth tendency
of adrenal incidentalomas is slow and they seem to remain hormonally inactive.
PMID- 10787081
TI - Early gastric cancer: unrecognized indicator of multiple malignancies.
AB - The aim of this study was to evaluate the postoperative outcome and occurrence of
second primary malignancies in patients who underwent radical resection for early
gastric cancer. Altogether 105 patients with early gastric cancer underwent
radical resection and were followed up for a median period of 71 months. Overall
lethality was analyzed with regard to mortality due to gastric cancer or other
causes. Standardized mortality and morbidity ratios were calculated using data
from the Tumor Registry of Lombardy. The 5-year survival rate was 82.8%
(operative mortality excluded), which was not different from that expected from
an age- and sex-matched Italian population. Ten second primary malignancies were
identified, giving a standardized mortality ratio of 1.12 and a standardized
morbidity ratio of 1.50. Patients undergoing surgery for early gastric cancer
(especially the intestinal type) may have a circa 50% higher risk of a second
tumor and should be periodically checked for other tumors, mainly in the
supramesocolic area.
PMID- 10787082
TI - Long-term survival of transmural advanced gastric carcinoma following curative
resection: multivariate analysis of prognostic factors.
AB - Patients with transmural (T2N0-T3N2) advanced gastric carcinoma comprise the
largest group with uncertain outcome. These patients must be stratified according
to the prognostic variables so the high risk group can be precisely identified. A
total of 152 patients with transmural advanced gastric carcinomas were uniformly
treated with a curative intent between 1979 and 1989 with at least a 7-year
follow-up. Results and prognostic factors of long-term survival were analyzed by
univariate and multivariate analyses. Seventy-five (49%) patients with advanced
gastric carcinoma survived more than 7 years, which indicates the curative nature
of surgery for gastric carcinoma. Seventeen variables were evaluated by
univariate analysis. In the multivariate analysis, patient's age [>70 years,
relative risk (RR) 2.4)], intraoperative blood loss (>500 ml, RR 1.7), blood
vessel invasion (RR 2.3), ratio of invaded dissected lymph nodes (>0.2, RR 3.0),
and tumors penetrating the serosa (RR 3.9) were the independent prognostic
variables. The results of this study indicate that extensive lymphadenectomy and
minimal intraoperative blood loss might be helpful for improving patient survival
following a curative resection. Patients with vessel invasion, serosal
involvement, and those >70 years of age should be considered at high risk and
require appropriate adjuvant therapy to prolong survival.
PMID- 10787083
TI - Surgery for ductal adenocarcinoma of the pancreatic head: staging, complications,
and survival after regional versus extended lymphadenectomy.
AB - The purpose of this study was to evaluate the influence of regional versus
extended lymphadenectomy on survival after partial pancreaticoduodenectomy for
pancreatic cancer. From October 1988 to December 1991 (Department of Surgery,
University of Hamburg) and from January 1992 to March 1998 (Department of
Surgery, University of Kiel) 72 patients with histologically proven ductal
adenocarcinoma of the pancreatic head were treated. Partial
pancreaticoduodenectomy with regional lymphadenectomy was performed in 26
patients. In 46 patients lymphadenectomy was expanded to include extended
retroperitoneal lymphatic and connective tissue clearance. Comparing these two
groups and including only patients with R0 resections (n = 58) no significant
differences in long-term survival could be shown. The following parameters were
shown to have a significant or nearly significant influence on long-term
survival: (1) stage of the disease: The 5-year survival of patients with stage
I/II pancreatic head cancer was 63%, compared to 15% in patients with stage
III/IV a + b of the disease (p = 0.0087). (2) Grading: The 1-year survival of
patients with well or moderately differentiated tumors was 55%, compared to 0%
for patients with poorly differentiated ductal adenocarcinoma (p = 0.0022). (3) N
stage: The 5-year survival of patients in N0 stage was 46.9%, compared with 15%
for N1 stage patients. The difference was not quite significant (p = 0.081). (4)
Portal vein involvement: The 1-year survival was 0% in patients with R0
resections and histologically proven tumor infiltration of the portal vein,
compared to 63% for patients with curative resections without portal vein
involvement (p = 0.0063). In conclusion our data indicate that extensive
retroperitoneal tissue clearance during pancreaticoduodenectomy for ductal
pancreatic cancer does not improve survival compared to regional lymphadenectomy
restricted to the right side of the mesenteric artery.
PMID- 10787084
TI - Measuring the tumor volume of gastric carcinoma by computer image analysis:
clinical significance.
AB - The tumor diameter of gastric carcinoma, measured by gross or histologic
examination, is a rough indicator of actual tumor size. Therefore we investigated
the utility of three-dimensional reconstruction of tumors in gastric carcinoma.
Altogether 105 primary gastric carcinoma lesions, consisting of 16 advanced and
89 early carcinomas, were analyzed. A total of 942 lesion tissue sections,
comprising 2 to 37 sections per lesion (mean 9 sections), were examined
histologically. Surface rendering using a computer graphics analysis program was
then performed from serial sections to create a three-dimensional reconstruction
of tumor morphology from which to measure tumor volume. For the 105 lesions the
tumor diameter ranged between 4 and 106 mm (average +/- SE: 32.4 +/- 2.0 mm), and
tumor volume ranged between 4 and 5853 mm3 (average +/- SE: 773.0 +/- 104.6 mm3).
A significant correlation was found between tumor diameter and the log of the
tumor volume (r = 0.733, p < 0.0001). Although the logs of tumor volume for
advanced carcinomas were all > 2.5, in 11 of these 16 patients (66%) the tumor
diameter was < 4 cm, and in one patient < 2 cm. In addition, tumor diameter did
not differ significantly between the 16 advanced and the 89 early gastric
carcinomas (p = 0.114), whereas the log of the tumor volume did (p < 0.0001). In
conclusion, conventional measurements of tumor diameter as a rough indicator of
tumor size can predict the actual tumor size of a gastric carcinoma. Three
dimensional reconstruction using computer graphics provides a better estimation
of true tumor size and extent of progression than tumor diameter.
PMID- 10787085
TI - Protein expression of bax, bcl-2, and p53 in patients with non-Hodgkin's gastric
lymphoma: prognostic significance.
AB - The biologic significance of bcl-2, bax, and p53 gene expression in patients with
non-Hodgkin's gastric lymphoma is unknown. We examined the prognostic value of
these genes in 36 patients with gastric lymphoma treated in our clinic between
1990 and 1995. Paraffin-embedded specimens from 36 patients who underwent primary
resection of the stomach for gastric lymphoma were analyzed immunohistochemically
for p53, bax, and bcl-2 gene expression. Expression of bax was seen in 24 of 36
patients (66.7%), p53 expression was found in 8 of 36 tumors (22.2%), and bcl-2
cytoplasmic staining was detected in 6 of 36 patients (16.7%). We performed a
univariate analysis to examine the possible correlation between the expression of
these genes and the survival of our patients. Expression of bax protein proved to
be a statistically significant prognostic factor (p = 0.049). Protein expression
of p53 and bcl-2 did not statistically correlate with survival. In the bcl-2
negative (-) patient group (30 patients), those who were bax-positive had a
statistically significant better survival than those who were bax-negative (63.3%
vs. 36.7%, p = 0.03). There was also a statistically significant correlation
between p53 expression and the grade of the tumor (p = 0.0014). P53 protein
expression increased along with the grade. Expression of bax is a significant
prognostic factor in patients with gastric lymphoma. Its prognostic value
increases significantly when studied in bcl-2-negative patients; but expression
of bax failed to be an independent prognostic factor. Expression of bcl-2 and p53
has no prognostic significance. Expression of p53 seems to represent a marker for
loss of differentiation.
PMID- 10787086
TI - Fatal wounding of the Byzantine Emperor Julian the Apostate (361-363 A.D.):
approach to the contribution of ancient surgery.
AB - Byzantine surgery flourished from the early stages of the Byzantine empire (324
1453 A.D.). The first great Byzantine physicians, among the most eminent being
Oribasius from Pergamun (fourth century), not only compiled anthologies of the
works of ancient Greek, Alexandrian, and Roman physicians but added their own
personal practical experience and observations. The circumstances surrounding,
and the treatment of, the fatal abdominal wounding of one of the most renowned
emperors of Byzantium, Julian the Apostate (361-363 A.D.), is examined based on
historical accounts unknown in the broader medical bibliography, namely, the
histories and chronicles of Byzantine writers. From this analysis it can be
concluded that the emperor's physician, Oribasius, in all probability, applied
knowledge of ancient Greek and Roman surgery to save his famous patient. The
techniques of "gastrorrhaphy" and pharmaceutical confrontation of the wound in
that era, adopted later by the surgeons of the Medieval West, seem to constitute
noteworthy roots of modern surgery.
PMID- 10787087
TI - Hepatectomy for colorectal hepatic metastases.
PMID- 10787088
TI - The incidence of infection in dirty surgical wounds.
PMID- 10787089
TI - The historical review on gastric surgery by Weil and Buchberger.
PMID- 10787090
TI - Dehalogenation of xenobiotics as a consequence of binding to humic materials.
AB - Chlorinated phenols and anilines were transformed by oxidoreductive catalysts
with release of chloride ions in both the absence and the presence of humic
substances (syringaldehyde, catechol, and humic acid). Dehalogenation of these
xenobiotics resulted from oxidative coupling reactions occurring at the
chlorinated sites of the substrates. The effect of humic substances on
dehalogenation depended on the mechanism of oxidative coupling. In a free-radical
reaction mediated by peroxidase, laccase, or birnessite (delta-MnO2),
syringaldehyde enhanced the dehalogenation of most of the chlorinated phenols,
but it did not enhance the dehalogenation of the chloroanilines. With catechol,
which does not form free radicals, dehalogenation was reduced or remained the
same for both the chlorophenols and the chloroanilines. However, in tyrosinase
mediated reactions controlled by nucleophilic addition, catechol enhanced the
dehalogenation of most of the chlorophenols, whereas syringaldehyde had little
effect. Humic acid in most cases enhanced the dehalogenation of the
chlorophenols, but it had little effect on the dehalogenation of the
chloroanilines. On a molar basis, changes in dehalogenation caused by humic
substances were proportional to the respective changes in substrate
transformation. Only syringaldehyde was capable of releasing disproportionately
high amounts of chloride ions from chlorophenols, apparently as a result of
multiple crosscouplings to one molecule of the substrate.
PMID- 10787091
TI - A multidisciplinary approach to assess history, environmental risks, and
remediation feasability of soils contaminated by metallurgical activities. Part
A: chemical and physical properties of metals and leaching ability.
AB - Three soils contaminated by heavy metals (HMs) and aliphatic hydrocarbons
originating from different industrial sources were characterized in a
multidisciplinary study combining chemical, physical (Part A), and mineralogical
(Part B) approaches to define history, environmental risks, and remediation
feasibility. These were an agricultural soil located nearby a Zn/Pb smelter and
two soils from a steel metallurgical (siderurgy) waste land. High Pb and Zn
contents were reported for all, and high Cr, Cd, and aliphatic hydrocarbons were
present in different combinations in two out of three soils. Carbonate matrixes
more strongly cemented fine particles in the agricultural soil than in both
siderurgical ones, but buffering capacities were stronger in the latter. After
the disruption of these cements by ultrasounds, HM were concentrated in the <50
microm fraction of the agricultural and of one siderurgical soil. Sequential
extractions indicated for all the soils a preferential association of HM with
carbonates, Fe-Mn oxides, organic matter, and sulfides. The stirring of one
siderurgical soil with water resulted in an immediate leaching of hexavalent
chromium (0.3 mg x L(-1)) involving potential ecotoxicological risks.
PMID- 10787092
TI - A multidisciplinary approach to assess history, environmental risks, and
remediation feasability of soils contaminated by metallurgical activities. Part
B: direct metal speciation in the solid phase.
AB - Three soils contaminated by industrial smelting activities previously
characterized using chemical and physical approaches (Part A, Venditti et al.
[2000] Arch Environ Contam Toxicol [in press]) were further investigated through
a complementary mineralogical approach. X-ray diffraction allowed identification
of the main mineral components: carbonates (calcite, siderite) and iron oxides
(magnetite, hematite, goethite) prevailed in both siderurgical soils, and
siliceous compounds were more abundant in the agricultural soil. Scanning
electron microscopy coupled with energy dispersive x-ray microanalysis showed
that carbonates and oxides contained low amounts of heavy metals (HMs), but the
potential solubility of such species under acidic conditions associated to their
abundance may result in a high mobility of associated contaminants. Microanalysis
also revealed peculiar minor mineral forms (metallic nodules, alloys, ore
residues) that were highly informative about the history of soil contamination.
Small metal-rich particles were observed (brass, lead and zinc oxides). In such
compounds, HMs showed high chemical stability and were consequently poorly mobile
and toxic, but also poorly removable through chemical leaching. A risk of
mechanical dispersion was suggested for these particles, particularly after the
chemical and/or mechanical disruption of carbonate cements. These features
allowed completion and confirmation of the conclusions achieved after chemical
and physical investigations, providing accurate information about the history,
environmental risks and remediation feasability of industrial soil contamination.
PMID- 10787093
TI - Characterization of selected element concentrations and enrichment ratios in
background and anthropogenically impacted roadside areas.
AB - Previous research by the National Contaminant Biomonitoring Program found fish
from Manoa Stream, Hawaii, to have the highest concentrations of Pb in the
nation. To explore possible source linkages we sampled background
(uncontaminated) soil, roadside soil, and road deposited sediment in Manoa
watershed and analyzed them for total and extractable concentrations of Al, Co,
Cu, Fe, Mn, Ni, Pb, and Zn. Our concentration and enrichment ratio data indicate
that Al, Co, Fe, Mn, and Ni were controlled by natural source variations, and Cu,
Zn, and particularly Pb were anthropogenically enhanced. Labile Pb
concentrations, extracted with either dilute HCl or EDTA, reached a maximum of
3,560 mg/kg compared to background values of <10 mg/kg. Additionally, 25% of the
169 contaminated samples analyzed had EDTA-extractable Pb enrichment ratios > or
=11.5, where a value of 1 separates uncontaminated from contaminated media. Given
the proximity of most samples to roadways it is reasonable to conclude that
automotive emissions plus vehicle wear were the primary contributors of trace
metals to the roadside system. These data are discussed in context with previous
work on the fluvial bed sediments in this watershed in an attempt to examine the
potential linkage with the biological accumulation of Pb in fish from Manoa
watershed.
PMID- 10787094
TI - Influence of petroleum hydrocarbon contamination on microalgae and microbial
activities in a long-term contaminated soil.
AB - Petroleum hydrocarbons are widespread environmental pollutants. Although
biodegradation of petroleum hydrocarbons has been the subject of numerous
investigations, information on their toxicity to microorganisms in soil is
limited, with virtually no work conducted on soil algae. We carried out a
screening experiment for total petroleum hydrocarbons (TPH) and their toxicity to
soil algal populations, microbial biomass, and soil enzymes (dehydrogenase and
urease) in a long-term TPH-polluted site with reference to an adjacent unpolluted
site. Microbial biomass, soil enzyme activity, and microalgae declined in medium
to high-level (5,200-21,430 mg kg(-1) soil) TPH-polluted soils, whereas low-level
(<2,120 mg kg(-1) soil) pollution stimulated the algal populations and showed no
effect on microbial biomass and enzymes. However, inhibition of all the tested
parameters was more severe in soil considered to have medium-level pollution than
in soils that were highly polluted. This result could not be explained by
chemical analysis alone. Of particular interest was an observed shift in the
species composition of algae in polluted soils with elimination of sensitive
species in the medium to high polluted soils. Also, an algal growth inhibition
test carried out using aqueous eluates prepared from polluted soils supported
these results. Given the sensitivity of algae to synthetic pollutants, alteration
in the algal species composition can serve as a useful bioindicator of pollution.
The results of this experiment suggest that chemical analysis alone is not
adequate for toxicological estimations and should be used in conjunction with
bioassays. Furthermore, changes in species composition of algae proved to be more
sensitive than microbial biomass and soil enzyme activity measurements.
PMID- 10787095
TI - The role of ingestion as a route of contaminant bioaccumulation in a deposit
feeding polychaete.
AB - A mass-balance bioaccumulation model was used to examine the bioaccumulation of
benzo[a]pyrene (BaP) from ingested sediment by the deposit-feeding polychaete
Abarenicola pacifica over a series of experiments employing nine different
sediments. Through selective ingestion of fine-grained material, the worm was
able to increase the BaP content of ingested sediment by 10-35% above that of the
bulk material. During digestion, an average of 5-21% of the ingested BaP was
absorbed from gut contents. The relative importance of ingestion as a route of
BaP uptake was dependent on the time period of observation. Initial uptake of BaP
was postulated to come from absorption of dissolved BaP across the body wall
since, after short periods of exposure (<24 h), only 3-38% of observed BaP tissue
concentrations could have been derived from ingested material. With time and with
increased feeding activity, however, ingested sediment became the major source of
BaP to the organism. After 72 h of exposure, 36-119% of the tissue BaP (mean =
77%) was estimated to have been derived from dietary absorption of ingested
material, and with continued exposure the dietary route is likely to be as great
or greater as the relative significance of the initial uptake from the dissolved
phase diminishes. This work and other studies indicate that for many deposit
feeders, ingested sediment can be the primary source for the bioaccumulation of
hydrophobic toxicants.
PMID- 10787096
TI - Effects of cadmium and phenol on motility and ultrastructure of sea urchin and
mussel spermatozoa.
AB - Computer-assisted sperm analysis (CASA) was used to study the effects of Cd(II)
and phenol on sperm motility of sea urchin and mussel. In parallel,
ultrastructural changes of sperm induced by these two toxicants were also
investigated and related to motility impairment. Spermatozoa of sea urchin were
more sensitive than mussel spermatozoa to both toxicants. Sea urchin sperm
motility showed a good dose-response relationship to Cd(II) levels as well as
exposure time. Exposure to the two toxicants changed the size and shape of the
midpiece, which might affect the balance of spermatozoa in their swimming. The
plasma membrane became more convoluted, and such a change might affect the
streamlining and integrity of spermatozoa and hinder their normal movement
patterns. Most important, disorganization of mitochondrial membranes and cristae
was observed, suggesting disruption of ATP supply for sperm movement. Cadmium
also induced greater ultrastructural damages in sea urchin spermatozoa.
PMID- 10787098
TI - Ultrastructural localization of heavy metals (Hg, Ag, Pb, and Cu) in gills and
digestive gland of mussels, Mytilus galloprovincialis (L.).
AB - The intracellular localization of heavy metals using autometallography (AUM) was
studied in the gills and the digestive gland of the common mussel Mytilus
galloprovincialis, after an experimental exposure to 0.1 mg L(-1) of Hg, 0.1 mg
L(-1) of Ag, 0.1 mg L(-1) of Pb, and 0.1 mg L(-1) of Cu for 98 days. In the
gills, autometallographical black silver deposits (BSDs) were localized in the
dense bodies observed in the apical and in the basal part of the cells. Among
metals, Hg presented the highest accumulation, followed by Ag, Pb, and Cu. BSDs
were more prominent in the abfrontal part of the gill filament in the case of Hg
exposure and in the frontal part in the case of Ag and Pb exposure. In the
digestive gland, Hg and Ag were localized in the heterolysosomes and the residual
bodies of the digestive cells, as well as in the dense bodies of the basophilic
cells. The heavy metal exposure also affected the gross morphology of the
examined tissues and resulted in the fusion of residual bodies in the digestive
cells, the fragmentation or vacuolization of the rough endoplasmic reticulum, and
the increase in the number of granules in the basophilic cells. In the gills,
fusion of the gill filaments was also noted.
PMID- 10787097
TI - Polychlorinated biphenyls and metals in marine species from French Frigate
Shoals, North Pacific Ocean.
AB - Polychlorinated biphenyls (PCBs) and metals were analyzed in coral (Porites
lobata), fish (Stegastes fasciolatus), crab (Grapsus tenuicrustatus), and
sediment samples collected from Tern Island, and the reference samples from Trig
and La Perouse Islands. All three islands are part of French Frigate Shoals, a
national wildlife refuge in the North Pacific Ocean. Average concentrations of
total PCBs ranged from 154 to 274 ng/g in the sediments, from 120 to 267 ng/g in
the corals, from 387 to 4,500 ng/g in the crabs, and 1,340 to 46,000 ng/g, dry
weight, in the fishes. High concentrations in marine species indicate there is
PCB source(s) in French Frigate Shoals, especially Tern Island. Tetra- and
pentachlorobiphenyls were 64-66% of the total PCB levels in the sediments, and
they accounted for 57-65% of total PCBs in the corals. Penta- and
hexachlorobiphenyls were 76-84% of total PCBs in the fishes, and they accounted
for 79-85% in the crab samples. The sediment and coral were predominated by lower
chlorinated PCB congeners, whereas the fish and crab bioaccumulated mainly higher
chlorinated congeners. Selenium concentrations (16-23 microg/g) in sediments were
much higher than some reported baseline values (0.4-2.5 microg/g). The average
concentrations of arsenic, cadmium, lead, and selenium in the coral and fish were
about equal to or less than those in the sediments. Concentrations of arsenic and
cadmium in the crabs (49-51 and 3-4 microg/g, respectively) were approximately
twofold of those in the sediments.
PMID- 10787099
TI - Selenium concentrations in the Colorado pikeminnow (Ptychocheilus lucius):
relationship with flows in the upper Colorado River.
AB - A Department of the Interior (DOI) irrigation drainwater study of the Uncompahgre
Project area and the Grand Valley in western Colorado revealed high selenium
concentrations in water, sediment, and biota samples. The lower Gunnison River
and the Colorado River in the study area are designated critical habitat for the
endangered Colorado pikeminnow (Ptychocheilus lucius) and razorback sucker
(Xyrauchen texanus). Because of the endangered status of these fish, sacrificing
individuals for tissue residue analysis has been avoided; consequently, little
information existed regarding selenium tissue residues. In 1994, muscle plugs
were collected from a total of 39 Colorado pikeminnow captured at various
Colorado River sites in the Grand Valley for selenium residue analysis. The
muscle plugs collected from 16 Colorado pikeminnow captured at Walter Walker
State Wildlife Area (WWSWA) contained a mean selenium concentration of 17
microg/g dry weight, which was over twice the recommended toxic threshold
guideline concentration of 8 microg/g dry weight in muscle tissue for freshwater
fish. Because of elevated selenium concentrations in muscle plugs in 1994, a
total of 52 muscle plugs were taken during 1995 from Colorado pikeminnow staging
at WWSWA. Eleven of these plugs were from fish previously sampled in 1994.
Selenium concentrations in 9 of the 11 recaptured fish were significantly lower
in 1995 than in 1994. Reduced selenium in fish may in part be attributed to
higher instream flows in 1995 and lower water selenium concentrations in the
Colorado River in the Grand Valley. In 1996, muscle plugs were taken from 35
Colorado squawfish captured at WWSWA, and no difference in mean selenium
concentrations were detected from those sampled in 1995. Colorado River flows
during 1996 were intermediate to those measured in 1994 and 1995.
PMID- 10787101
TI - Vitellogenin induction and other biochemical responses in carp, Cyprinus carpio,
after experimental injection with 17 alpha-ethynylestradiol.
AB - Prespawning, adult male and female carp, Cyprinus carpio, were intraperitoneally
injected with a single dose of 500 microg/kg of 17alpha-ethynylestradiol (EE2).
Blood samples were taken and vitellogenin levels were recorded previous to the
injection and 8 days afterward. Western blot analysis of plasma VTG showed a
marked response in both males (90-fold) and females (67-fold) after EE2
injection. Also, a significant inhibition of the cytochrome P450 monooxygenase
system, namely, 7-ethoxyresorufin O-deethylase (EROD) activity, as well as
immunodetected CYP1A protein was observed in the EE2-injected fish. Other
cytochrome P450 isozymes, such as CYP3A or NADH cyt (b5) reductase, did not
indicate any particular trend; whereas NADPH cyt (P450) reductase was
significantly induced in EE2-injected animals. Total cytochrome P450, glutathion
S-transferase (GST), and total glutathion peroxidase (GPX) fluctuated in a
similar manner, but differences among treated and nontreated animals were not
statistically significant. UDP glucuronyl transferase (UDPGT), similar to the
antioxidant enzymes catalase, superoxide dismutase (SOD), and Se-GPX,
progressively decreased in carrier and injected animals in comparison to the
controls, although this trend did not reach statistical significance either.
PMID- 10787100
TI - Ecotoxicological assessment of persistent organic and heavy metal contamination
in Hong Kong coastal sediment.
AB - The aim of the present project is to determine the feasibility of measuring
hepatic cytochrome P4501A1 (CYP1A1) and metallothionein (MT) mRNA in fish as an
integrative measurement of persistent organic pollutants (POPs) and heavy metal
contamination in sediment arising in Hong Kong. Sediment samples were collected
from different sites, including Victoria Harbour (VS6), Yim Tin Tsai (YTT) at
Tolo Harbour, Mai Po marshes (MPM) at Deep Bay, and Southern Waters (SS6) of
coastal waters. The samples were analyzed for total and extractable
concentrations of Cd, Cu, Ni, Zn, and Pb, as well as PCBs and PAHs. In addition,
biomarker responses were studied in tilapia exposed experimentally to coastal
sediment for 7 days. Using RT-PCR technique, hepatic CYP1A1 and MT mRNA were
measured. Three control groups were used, including one negative control group
maintained in sea water only; the second and third positive control groups were
in sea water but were intraperitoneally injected with either beta-naphthoflavone
(40 microg/g body weight) or cadmium chloride (10 microg/g body weight),
respectively. The chemical data showed that VS6, YTT, and MPM were classified as
Class C sediment according to the sediment quality criteria defined by the Hong
Kong Environmental Protection Department, indicating the sites were heavily
polluted. The exposure of tilapia to the sediment induced hepatic CYP1A1 (VS6 >
YTT > MPM > SS6) and MT (VS6 > MPM > YTT > SS6) levels. The induction patterns
were comparable to the levels of POPs and metal contamination in the sediment,
indicating that the biomarker responses could be used to differentiate low to
high levels of contamination among sediment.
PMID- 10787102
TI - Metals and metalloids in tissues of American alligators in three Florida lakes.
AB - Concentrations of metals and selenium were examined in tissues of American
alligators (Alligator mississippiensis) from three lakes in central Florida, in
one of which alligators have exhibited reproductive or developmental defects. Our
overall objective was to determine whether the levels of metals were sufficiently
high to confound the association between chlorinated hydrocarbons, which are
elevated in eggs and juvenile plasma, and reproductive impairment. The
concentrations of all metals were relatively low compared to those reported for
alligators from elsewhere in Florida and the southeastern United States,
suggesting that reproductive impairment is not due to metals and that metals pose
no health risk to the alligators. We also wanted to determine whether skin,
biopsied tail muscle, or tail tip tissue, all easily collected from live
alligators, could be used as surrogate measures of internal tissue loads.
Concentrations of arsenic, cadmium, chromium, lead, manganese, mercury, and
selenium in liver were highly correlated with at least one of the three biopsied
tissues. Only tin showed no significant positive correlation. No single tissue
gave a high prediction of liver levels for all metals, although skin gave the
highest correlation for mercury, and tail muscle gave the best overall
correlation for lead and cadmium.
PMID- 10787103
TI - Toxic assessment of PCBs by the 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent in
common cormorant (Phalacrocorax carbo) from Japan.
AB - Common cormorants collected from three colonies and their fish diet were analyzed
for PCB congeners and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) were
estimated. The highest total PCBs (40 microg/g wet weight) found in adult
cormorants from Shinobazu Pond located in Central Tokyo, was sevenfold higher
than that from Lake Biwa. IUPAC 153 was the most abundant congener in adults and
eggs, whereas IUPAC 28 + 31 was higher in some chicks and exhibited growth
related congeneric enrichment. The estimated metabolic index (MI) for PCB
congeners revealed that monoand non-ortho coplanars had higher bioaccumulation in
cormorant liver and were expected to cause toxic effects. Among non-ortho
coplanars, IUPAC 126 was predominant, and total non-ortho coplanars and TEQs in
cormorants were threefold higher in Shinobazu Pond than those from Lake Biwa. The
non-ortho IUPAC 126 contributed a higher portion to the total TEQs followed by
IUPAC 105 and IUPAC 77. The hepatic IUPAC 169/126 ratio increased significantly
with TEQs, implying a potential induction of drug-metabolizing enzymes in
Shinobazu Pond cormorants. Based on the available data, PCB contamination in
cormorants is enough to pose sublethal effects, especially in Shinobazu Pond and
Godaiba Island, Tokyo, Japan. This could be a reason for recently observed high
chick and juvenile mortality in those colonies in Tokyo.
PMID- 10787104
TI - Mixed-function oxygenases, oxidative stress, and chromosomal damage measured in
lesser scaup wintering on the Indiana Harbor Canal.
AB - During the winter of 1993-1994, male lesser scaup (Aythya affinis) were collected
on the heavily polluted Indiana Harbor Canal, East Chicago, Indiana, and examined
for several bioindicators of chemical exposure. Livers were analyzed for
activities of three cytochrome P450-associated monooxygenases and four measures
of oxidative stress. Blood and spleen were analyzed by flow cytometry for
chromosomal damage. In a concurrent study, scaup tissues were analyzed for
organic and inorganic contaminants. Ethoxyresorufin-O-dealkylase (EROD) activity
in livers of scaup collected in January 1994 was significantly higher than in
livers of scaup collected in March 1994 or in livers of reference birds. Three
hepatic monooxygenase activities were each significantly correlated with
polycyclic aromatic hydrocarbon (PAH) concentrations in scaup carcasses.
Thiobarbituric acid (TBA) activity in scaup livers was positively correlated with
iron, boron, and lead concentrations in livers and polychlorinated biphenyl
concentrations in carcasses. TBA activity was negatively correlated with protein
bound thiol activity and mercury concentrations in livers. The coefficient of
variation of DNA content in scaup blood cells was correlated with PAH
concentrations in scaup carcasses. This is the first field study with birds to
demonstrate a correlation between liver monooxygenase activity and carcass PAH
concentrations and to show a direct correlation between PAH concentrations in
tissues and somatic chromosomal damage in blood.
PMID- 10787106
TI - Sensitivity of a standard host resistance assay using Streptococcus agalactiae
for assessing exposure to immunotoxicants in wild cotton rats (Sigmodon
hispidus).
AB - Resident small mammals have been used for in situ biomonitoring of contaminated
waste sites containing suspected immunotoxicants. Host resistance assays, which
involve challenging animals with an actual pathogen, allow for testing of overall
immune system function in animals. Because such assays have not been evaluated
for use with wild rodent species, it was our objective to assess the efficacy of
Streptococcus agalactiae as a pathogenic model for use in a host resistance assay
for detecting alterations in immune system function in wild cotton rats (Sigmodon
hispidus). The ability of the assay to detect immunosuppression was evaluated by
inducing immunosuppression chemically (cyclophosphamide or dexamethasone) and by
protein malnutrition. The estimated lethal dose of S. agalactiae that killed 50%
of challenged animals (LD50) was 5.76x10(7) colony-forming units (CFUs). Although
bacterial agglutination titers indicated that animals developed an antibody
response when immunized, immunization was not sufficient to adequately protect
animals from a subsequent pathogenic challenge. Sensitivity of the host
resistance assay was only suitable for detecting substantial immunosuppression,
such as that induced by protein malnutrition or dexamethasone administration.
PMID- 10787105
TI - Strychnine alkaloid and avian reproduction: effects occur at lower dietary
concentrations with mallard ducks than with bobwhite quail.
AB - Separate subchronic reproductive toxicity studies were conducted using mallard
ducks (Anas platyrhynchos) and northern bobwhite quail (Colinus virginianus).
Three groups (32/group; 16 male-female pairs) of 17-week-old ducks (F0
generation) were fed Purina Game Bird Breeder Layena diets containing mean (+/
SD) 33.2 (+/-2.7), 68.9 (+/-1.8), and 140.9 (+/-5.1) microg/g strychnine for 20
weeks, with some pairs in each group fed control diet during a subsequent 3-week
recovery period. Three groups (32/group; 16 male-female pairs) of 19-week-old
quail (F0 generation) were fed similar diets containing mean (+/-SD) 279.2 (+/
10.1), 557.4 (+/-43.5), and 1,113.6 (+/-46.6) microg/g strychnine for 22 weeks
without a recovery period. Separate groups of ducks and quail (32/group; 16 male
female pairs) were also fed control diets (0.0 microg/g strychnine) in each
study. There were 16 weekly collections of eggs for the mallard study (13 for the
diet-exposure period and 3 for the recovery period), and 11 collections for the
quail study. Eggs laid during the last 13 and 10 weeks of the diet-exposure
periods for ducks (plus 3 weeks of the recovery period) and quail, respectively,
were incubated. Each hatch of F1 generation ducklings and chicks was observed for
14 days. Key results were: (1) the no observed adverse effect levels (NOAELs) for
F0 ducks and quail were 33.2 and 1,113.6 microg/g strychnine, respectively--quail
showed no reproductive effects at the current doses; (2) decreased egg production
and hatching success occurred for mallard hens fed mean 140.9 microg/g strychnine
diets; and (3) "normal-hatching" ducklings from eggs of F0 mallards fed mean
140.9 microg/g strychnine diets suffered greater mortality than ducklings from
the other diet groups. Possible mechanisms of strychnine action on avian
reproduction are discussed.
PMID- 10787107
TI - Malathion deposition, metabolite clearance, and cholinesterase status of date
dusters and harvesters in California.
AB - Date gardens in the Coachella Valley in California typically receive multiple
treatments of malathion to control major insect pests. Variable amounts of
malathion dust retention by skin and clothing and individual work behaviors limit
the usefulness of clothing as an exposure dosimeter in date dusters and
harvesters. To determine malathion absorption in workers, urine clearance of
dimethyl phosphates (alkyl phosphates; AP) and malathion mono- (MCA) and di-
(DCA) acids were estimated from date dusters (loaders/applicators) and harvesters
(both on ground and high in trees). A series of self-administered doses of
malathion were either ingested in gelatin capsules or applied to the volar
surface of the forearm to guide biomonitoring. Each of the dimethyl phosphates
(dimethylthio> dimethyldithio > dimethyl-) and both malathion mono- and diacids
were present in urine as soon as 2-3 h of work. On a micromole basis
dimethylthiophosphate and the malathion acids (MCA > DCA) were the most prominent
metabolites in urine. Applicator exposures ranged from 95-210 mg equivalents per
day (1-3 mg/kg-day). Harvester exposures ranged from 1-270 microg/kg-day. Mid
season Monday morning urine specimens before work contained low or unmeasurable
levels of malathion acids, indicating that malathion is rapidly metabolized and
cleared from the body in the urine. Saliva was not useful for biomonitoring. No
inhibition of cholinesterase activity was measured in any members of two separate
crews of harvesters who had previous prolonged dust exposure (1 and 2 months).
PMID- 10787108
TI - Therapeutic options in dementia.
AB - Dementia is the final common path of various pathogenetic mechanisms that may
lead to a number of different clinical forms, with primary degenerative and
vascular dementias accounting for more than 80% of cases. Dementia is a complex
clinical condition that includes cognitive, personality, and behavioral changes.
Therefore a therapeutic approach to dementia should be based from the beginning
on a comprehensive intervention plan, both pharmacological and
nonpharmacological. This should not be aimed at obtaining a complete (impossible)
recover but at achieving the best day-to-day management of a chronic,
progressive, disabling disease involving numerous domains and showing impairments
with varying rates of progression. Deterioration in functional abilities of daily
living has a major impact on the quality of life of those suffering from
dementia, and this is a critical predictor for institutionalization. Increasingly
necessary for optimizing intervention strategies are studies to: (a) measure
changes in functional abilities over the course of dementia (namely Alzheimer's
disease), (b) evaluate the relationship between functional abilities and
cognition, and (c) quantify the effect of various therapeutic approaches on
functional decline. Symptomatic drugs affecting cognitive abilities and
psychoactive drugs for behavioral disturbances should be considered. For the
cognitive domain positive results have been obtained with acetylcholinesterase
inhibitors. Among the psychoactive drugs indicated for behavioral disorders,
significant improvement in terms of both efficacy and tolerability can be
expected from the use of new antipsychotic drugs.
PMID- 10787109
TI - Distal myopathies.
AB - Distal myopathies are classified according to clinical, histopathological, and
genetic patterns into the following: late adult onset type 1, or Welander
myopathy, the first recognized distal myopathy with autosomal dominant
inheritance and very recently linked to chromosome 2p; late adult onset type 2,
or Markesbery-Griggs/Udd myopathy, autosomal dominant with linkage to chromosome
2q; early adult onset type 1, or Nonaka myopathy, an autosomal recessive disease
linked to 9p1-q1 and considered indistinguishable from hereditary inclusion body
myopathy; early adult onset type 2, or Miyoshi myopathy, with autosomal recessive
inheritance linked to chromosome 2p12-p14; and early adult onset type 3, or Laing
myopathy, autosomal dominant with linkage to chromosome 14. Very recently,
dysferlin, a novel skeletal muscle gene, has been found mutated in Miyoshi
myopathy and also in the limb girdle muscular dystrophy 2B, a disease with a
completely different phenotype. This indicates that the classification of the
distal and other genetically determined muscle diseases will probably change when
these myopathies are understood at the molecular level. For example, it would be
reasonable to use the term dysferlinopathies to describe all the diseases due to
dysferlin mutations.
PMID- 10787110
TI - Genomic HLA profiles of MS in Hokkaido, Japan: important role of DPB1*0501
allele.
AB - The polymorphism of the HLA class II genes was investigated in 97 patients with
multiple sclerosis (MS) in Hokkaido, the northernmost main island of Japan. Of
these, 80 patients were classified as having conventional MS and 17 as having
opticospinal MS (OS-MS). Our findings confirmed a previous report that the DPB
1*0501 allele is positively associated with OS-MS (P = 0.0043). The frequency of
DPB 1*0501 was also found to be higher in conventional MS patients than in
controls (79% vs. 58%, P = 0.0084), although the differences were not
statistically significant. Our results indicate that OS-MS is a DPB 1*0501
associated subgroup of MS, and that DPB1*0501 is also correlated with risk of
conventional MS in Japanese.
PMID- 10787111
TI - Antisaccades and remembered saccades in mild traumatic brain injury.
AB - The most common site of focal lesions after mild traumatic brain injury (MTBI) is
the frontal lobe. This lobe, however, is difficult to examine clinically.
Neuroimaging is not performed routinely and usually shows normal results in
uncomplicated trauma. Antisaccades (AS) and remembered saccades (RS) are neuro
ophthalmological tests of frontal function. This study examined whether there are
disturbances of latency time or error rate of AS and RS in patients within 24 h
after MTBI. Eye movements were studied with infrared-oculography. Data were
obtained prospectively from 25 patients. An additional group of 6 patients with
MTBI and alcohol intoxication were also examined. No statistical differences in
AS or RS, either for errors or for latency time, were found between a group of
age-matched controls and the patients, except in the group of alcohol-intoxicated
MTBI patients. Our findings indicate that visual reflex inhibition and initiation
of voluntary saccades were not disturbed in the nonintoxicated patients. It is
hypothesized that the responsible frontal area was not affected. It is concluded
that error rate and latency time of AS and RS are inappropriate measures for
evaluating acute MTBI.
PMID- 10787112
TI - Placebo effect in the acute treatment of migraine: subcutaneous placebos are
better than oral placebos.
AB - We carried out a meta-analysis of 22 trials to determine the comparative placebo
effect of (a) subcutaneous vs. oral and (b) in-hospital vs. at-home
administration in the treatment of migraine. The headache relief rates were
combined from the placebo arms of these randomised clinical trials assessing the
value of sumatriptan in acute treatment of migraine. The main outcome measure was
the proportion of patients reclassified from severe or moderate headache severity
to no or mild headache severity 2 h after the beginning of treatment. In the oral
regimen 222 of 865 patients (25.7%) reported no or mild headache severity after 2
h, compared to 279 of 862 patients (32.4%) of those receiving subcutaneous
placebo (6.7% difference; 95% CI 2.4-11.0%). Adjusting for treatment setting and
severity of headache at baseline did not change the observed difference. After
placebo treatment at home 285 of 1,054 patients (27.0%) reported no or mild
headache severity after 2 h, compared to 216 of 673 patients (32.1%) among those
receiving placebo in hospital (5.1 % difference; 95% CI 0.6-9.5%). When adjusted
for route of administration and severity of headache at baseline, the difference
in relief rates between home and hospital setting disappeared. These findings
indicate that subcutaneous administration enhances the placebo effect of acute
treatment of migraine. Future trials of antimigraine drugs assessing the relative
efficacy of various routes of administration should use a double-dummy technique.
The interpreting of placebo-controlled trial results must therefore consider that
the effect in the drug arm of the trial depends in part on the route of
administration.
PMID- 10787113
TI - Neurophysiological features of fasciculation potentials evoked by transcranial
magnetic stimulation in amyotrophic lateral sclerosis.
AB - We report 13 patients with amyotrophic lateral sclerosis in whom fasciculation
potentials (FPs) driven by transcranial magnetic stimulation (TMS) were recorded.
A total of 18 different FPs were analyzed. TMS-driven fasciculations had a simple
morphology and were stable. Complex potentials were never cortically driven.
Recruitment by a slight voluntary contraction was verified in 7 of 13 tested FPs.
FPs were driven by threshold stimuli in 7 of 10 patients and by stimuli 5% below
threshold in 3 of 6. Mapping demonstrated that FPs were driven in an area close
to the center of gravity of the muscle cortical area. In one case FPs were evoked
from most of the cortical representation area of a very weak muscle. Three other
patients with profuse fasciculations associated with other clinical conditions
were also studied. No TMS evoked fasciculation was observed in this group. The
results of this systematic study suggest that cortically evoked FPs arise
centrally, at spinal cord or even more proximally, and can represent a marker of
increased corticomotor excitability, which is predominant at an earlier phase but
can persist as the disease progresses.
PMID- 10787114
TI - Quality of life in patients with axonal polyneuropathy.
AB - "Quality of life" (QOL) measurement reflects the impact of a disease on the daily
life of a patient, and this can be used as an outcome measure in clinical trials.
QOL measurements are rarely used in patients with neuromuscular disease. The aim
of this study was to determine whether QOL is reduced in chronic polyneuropathy,
whether there is a relationship between QOL and objective measures of disease
severity, and whether measuring QOL is a useful addition to the assessment of
severity of polyneuropathy. We measured QOL in 90 patients with chronic axonal
polyneuropathy (33 with hereditary motor and sensory neuropathy type II and 57
with chronic idiopathic axonal polyneuropathy) using the RAND 36-item Health
Survey questionnaire (RAND-36). We compared the results with the QOL of a
reference population, with summed motor and sensory scores, and with the Rankin
scale for handicap. Patients had worse scores than the reference population on
seven of eight areas of the RAND-36. Patients with both low motor and low sensory
scores rated lower in physical and emotional areas than less impaired patients. A
low Rankin score was related only to physical domains. We conclude that in
patients with chronic axonal polyneuropathy the severity of disease can be
assessed with a general QOL instrument, and that this provides additional
information, particularly on areas related to emotional and social functioning.
PMID- 10787115
TI - Constantin von Monakow's formative years in Pfafers.
AB - Constantin von Monakow was the first professor of neurology in Switzerland and
founder of the Swiss Neurological Society and of the Swiss Archives of Neurology
and Psychiatry. He gained worldwide reputation as a neuroscientist mainly through
his monumental work on neuropathology and cortical localization. His concept of
diaschisis has been verified only in recent years by modern network concepts and
imaging techniques. The basis of his work was developed with ingenious animal
experiments and careful clinico-pathological comparisons during his early years,
which he spent as assistant physician in the psychiatric clinic at St.
Pirminsberg in Pfafers, Canton St. Gallen, Switzerland from 1878 to 1885.
PMID- 10787116
TI - Progressive supranuclear palsy: earlier age of onset in patients with the tau
protein A0/A0 genotype.
AB - Genetic studies have detected an association between the presence of the tau gene
A0 allele and patients with progressive supranuclear palsy (PSP). This study
examined whether patients with this polymorphism exhibit distinct demographic or
clinical characteristics. We studied 26 patients who fulfilled clinical criteria
for the diagnosis of PSP, 20 who had the A0/A0 genotype and 6 who had other
genotypes. A questionnaire on demographic data, past medical history, familial
history, and initial symptoms was completed as part of the consultation. A
complete neurological examination was performed and PSP symptoms were quantified
following Golbe's PSP disability scale. We found a significant difference in the
age at onset of PSP symptoms, which was 65.9 +/- 5.3 years in the A0/A0 group and
71.2 +/- 5.6 in the non-A0/A0 group (P = 0.016). There were no significant
differences in the years from disease onset between the two groups. Symptom
severity did not differ significantly in patients with the different A0/A0
genotypes. The detection of significantly lower age at onset with the A0/A0
alleles is consistent with the known association of this genotype as a risk
factor for PSP. No significant differences were detected in symptom severity
between the two groups of patients.
PMID- 10787117
TI - Managing the therapeutic dilemma: patients with spontaneous intracerebral
hemorrhage and urgent need for anticoagulation.
AB - Physicians face a therapeutic dilemma in patients with acute hemorrhagic stroke
requiring long-term, high-intensity anticoagulants because this treatment
increases the risk of intracranial hemorrhage (ICH) 8- to 11-fold. We
retrospectively studied 15 patients with ICH which occurred under anticoagulation
with phenprocoumon, with an international norrmalized ratio (INR) of 2.5-6.5 on
admission. Hemispheric, thalamic, cerebellar, intraventricular, or subarachnoid
hemorrhage without aneurysm occurred. Absolute indications for anticoagulation
were double, mitral, or aortic valve replacement, combined mitral valve failure
with atrial fibrillation and atrial enlargement, internal carotid artery-jugular
vein graft, frequently recurring deep vein thrombosis with risk of pulmonary
embolism, and severe nontreatable ischemic heart disease. As soon as the
diagnosis of ICH was established, INR normalization was attempted in all patients
by administration of prothrombin complex, fresh frozen plasma, or vitamin K.
After giving phenprocoumon antagonists (and neurosurgical therapy in four
patients) heparin administration was started. Nine patients received full-dose
intravenous and six low-dose subcutaneous heparin. The following observations
were made: (a) All patients with effective, full-dose heparin treatment with a
1.5- to 2-fold elevation in partial thromboplastin time after normalization of
the INR were discharged without complication. (b) Three of four of the patients
with only incomplete correction of the INR (> 1.35) experienced relevant
rebleeding within 3 days (all patients with an INR higher than 1.5), two of whom
were on full-dose heparin. (c) Three of seven of the patients with normalized INR
and without significant PTT elevation developed severe cerebral embolism.
Although our data are based on a retrospective analysis, they support treatment
with intravenous heparin (partial thromboplastin time 1.5-2 times baseline value)
after normalization of the INR in patients with an ICH and an urgent need for
anticoagulation.
PMID- 10787119
TI - Bickerstaff's brainstem encephalitis associated with shingles.
PMID- 10787118
TI - Idiopathic autonomic neuropathy associated with esophageal dilatation.
PMID- 10787120
TI - Localized lipoatrophy after prolonged treatment with copolymer 1.
PMID- 10787121
TI - Involvement of the visual pathway in hereditary neuropathy with liability to
pressure palsies.
PMID- 10787122
TI - Multifocal cerebral demyelination after magic mushroom abuse.
PMID- 10787123
TI - Evidence of diffuse brain pathology and unspecific genetic characterization in a
patient with an atypical form of adult-onset Krabbe disease.
PMID- 10787124
TI - Autonomic failure preceding dementia with Lewy bodies.
PMID- 10787125
TI - Diffusion magnetic resonance imaging findings in cerebritis and brain abscesses
in a patient with septic encephalopathy.
PMID- 10787126
TI - Andre-Thomas (1867-1963).
PMID- 10787127
TI - Nogo-A is the inhibitor of CNS axon regeneration.
PMID- 10787128
TI - Occupational and environmental medicine in Colombia.
AB - Colombia is a country rich in natural resources, with a steadily developing
economy. Occupational and environmental medicine (OEM) education and practice
have developed relatively recently in Colombia, mainly in response to a series of
long overdue (and still partially implemented) reforms to the health care, social
benefits, and education systems. Expansion in general and occupational health
coverage of the Colombian population and development of OEM education and
training were to be achieved through a clear stimulus to private sector
initiatives. Despite some measurable overall progress, the goals remain elusive.
This article discusses several aspects and the perspectives for further
development of the specialty in this country, in the context of the socioeconomic
factors involved in that process.
PMID- 10787129
TI - Pathophysiology and classification of the vibration white finger.
AB - Skin, arteries and nerves of the upper extremities can be affected by vibration
exposure. Recent advances in skin and vascular biology as well as new
investigative methods, have shown that neurovascular symptoms may be due to
different vascular and neurological disorders which should be differentiated if
proper management is to be evaluated. Three types of vascular disorder can be
observed in the vibration white finger: digital organic microangiopathy, a
digital vasospastic phenomenon and arterial thrombosis in the upper extremities.
An imbalance between endothelin-1 and calcitonin-gene-related peptide is probably
responsible for the vasospastic phenomenon. Moreover, paresthesiae can be due to
either a diffuse vibration neuropathy or a carpal tunnel syndrome. A precise
diagnosis is then necessary to adapt the treatment to individual cases. A
classification describing the type and severity of the vascular lesions is
presented. Asymptomatic lesions are included for adequate epidemiological studies
and risk assessment of vibrating tools. Monitoring of vibration exposed workers
should include not only a questionnaire about symptoms, but also a clinical
evaluation including diagnostic tests for the screening of early asymptomatic
neurovascular injuries.
PMID- 10787130
TI - Fractionation of nickel species from airborne aerosols: practical improvements
and industrial applications.
AB - Presently recommended methods for fractionation of airborne nickel dusts are
laborious and time-consuming. A new method has been developed based on existing
procedures of leaching nickel fractions from sample filters, and based on the
principles of flow-injection analysis. A special sample filter holder has been
constructed to be used in conjunction with the flow-injection system. In this
system, soluble nickel compounds are extracted from the filter with ammonium
citrate buffer, sulphidic nickel by peroxycitric acid, and metallic nickel by
CuCl2/KCl. The final dissolution of the filter by HNO3/HCl results in the oxidic
fraction. Endpoint determination of these fractions is performed by use of
graphite-furnace atomic absorption spectrometry (GF-AAS). The analytical criteria
of this method have been established, and the suitability of the method for
application in the practice of industrial hygiene has been demonstrated.
PMID- 10787131
TI - Correlation between urine and blood concentrations, and dietary intake of cadmium
and lead among women in the general population of Japan.
AB - OBJECTIVE: To examine whether lead (Pb) in urine and cadmium (Cd) in blood,
especially the former, can be used as markers of environmental exposure of
general populations to these metals. METHODS: Between 1991 and 1998, spot urine
and peripheral blood samples, together with 24 h duplicates of food intake were
collected from 607 non-smoking adult women in 30 survey sites (SS) in seven
administrative regions all over Japan. Urine, blood and food duplicate samples
were analyzed by inductively-coupled plasma spectrometry, for Cd and Pb in urine
(Cd-U and Pb-U), in blood (Cd-B and Pb-B) and in food duplicates (Cd-F and Pb-F).
Correlation between the measurements was examined by regression analysis.
RESULTS: The Cd-B correlated closely with Cd-U, and both Cd-B and Cd-U with Cd-F,
on an individual basis (n = 607), on an SS basis (n = 30) and on a regional basis
(n = 7). The Pb-U however did not correlate with Pb-B on a regional basis
although they correlated with each other when analyzed on an individual as well
as SS basis. Moreover, the correlation coefficients between Pb-U and Pb-B were
much smaller than those between Cd-U and Cd-B. Neither Pb-U nor Pb-B showed
significant correlation with Pb-F on any levels of statistical analysis.
CONCLUSIONS: Both Cd-B and Cd-U can be employed as biomarkers of environmental Cd
exposure. The reliability of Pb-U for use in place of Pb-B appeared to be small.
PMID- 10787132
TI - Risk of lung cancer in workers producing stainless steel and metallic alloys.
AB - OBJECTIVES: The mortality of workers involved in the production of stainless and
alloyed steel from 1968 to 1992 was studied, in order to investigate the risk of
lung cancer due to exposure to metals, i.e. iron oxides, chromium and/or nickel
compounds. METHODS: The study design was a historical cohort mortality study and
a nested case-control study concerning lung cancer. Standardized mortality ratios
(SMRs) were computed using regional mortality rates as an external reference for
comparing observed and expected numbers of deaths, adjusting for age, sex and
calendar time. Conditional logistic regression was used to estimate odds ratios
(ORs). Occupational exposure was assessed through the complete job histories of
cases and controls and a specific job-exposure matrix. RESULTS: The cohort
comprised 4,288 male and 609 female workers. The observed overall mortality was
significantly lower than expected [649 deaths; SMR = 0.91; 95% confidence
interval (CI) 0.84-0.98]. No significant SMR was observed for mortality from lung
cancer (54 deaths; SMR = 1.19; CI 0.88-1.55). The case-control study was based on
54 cases and 162 individually matched controls. Smoking habits were available for
71%. No lung cancer excess was observed for exposure to (1) metals and/or their
compounds, i.e. iron (OR = 0.94, CI 0.48-1.86), chromium and/or nickel (OR =
1.18, CI 0.62-2.25), and cobalt (OR =0.64, CI 0.33-1.25), (2) acid mists (OR =
0.43, CI 0.17-1.10), and (3) asbestos (OR = 1.00, CI 0.54-1.86). With respect to
exposure to polycyclic aromatic hydrocarbons (PAHs) and silica, which are often
found together in workplaces, (1) high and statistically significant lung cancer
excesses were observed, the ORs being 1.95 (CI 1.03-3.72) and 2.47 (CI 1.28-4.77)
respectively, (2) quantitative exposure parameters revealed upward trends
reaching statistical significance (P < 0.05), and (3) adjustments for tobacco
consumption did not reveal any confounding factors from smoking. CONCLUSION: This
study failed to detect any relationship between lung cancer and exposure to iron,
chromium, nickel and/or their compounds. High and statistically significant
relative risks, along with increasing trends, were observed for simultaneous
exposure to PAHs and silica.
PMID- 10787133
TI - Challenge from methacholine, natural rubber latex, or 4,4-diphenylmethane
diisocyanate in workers with suspected sensitization affects exhaled nitric oxide
[change in exhaled NO levels after allergen challenges].
AB - OBJECTIVE: Nitric oxide (NO) levels in the exhaled air of asthmatic patients have
been shown to be increased. This observation has also been reported in workers
who are allergic to laboratory animals. To determine if a challenge test with
natural rubber latex (NRL) or 4,4'-diphenylmethane diisocyanate (MDI) would also
produce an increase of NO exhalation in sensitized patients, we carried out this
study. METHODS: Nine subjects with suspected occupational asthma were exposed to
MDI, and 18 took part in a challenge test with gloves powdered with NRL. Nineteen
subjects underwent a challenge test with methacholine (MCh). Exhaled NO was
measured by a modified chemiluminescence analyzer according to the European
Respiratory Society guidelines. RESULTS: We found that there was a decrease in
exhaled NO concentrations 16-18 h after MCh challenge testing and subsequent
bronchodilation with salbutamol, in three subjects. Three of nine participants
had a significant immediate bronchial obstruction after exposure to MDI, of those
three, two had MDI-specific IgE antibodies. After 22 h, their levels of exhaled
NO had increased > 10 parts per billion (ppb). Eight of the 18 subjects
participating in the NRL challenge test displayed an NO concentration increase of
at least 10 ppb after 22 h (seven had NRL-specific IgE antibodies). A significant
decrease in the one-second forced expiratory volume (FEV1) was documented in four
of those eight participants after NRL challenge. CONCLUSIONS: There was no clear
relationship between bronchial response, substance-specific IgE antibodies and an
increase in exhaled NO levels. However, there was a tendency for subjects with
substance-specific IgE antibodies and bronchial reaction to develop an increase
in exhaled NO concentration. Further studies are needed to determine if analysis
of NO from the lower respiratory tract can become a useful non-invasive tool for
detecting lower airway inflammatory response even before clinical symptoms occur.
PMID- 10787134
TI - Improvement of thermophysiological stress in participants wearing protective
clothing for spraying pesticide, and its application in the field.
AB - Thermoregulatory responses were compared under two experimental conditions, in
the laboratory (Experiment I), and in the field (Experiment II), between two
kinds of protective clothing for spraying pesticides. One was currently being
used (Type A), and was composed of ready made Gore-Tex clothing, mask,
polyurethane gloves and rubber boots. The other one was newly designed (Type B),
and was composed of pesticide-proof clothing (100% cotton with water repellent
finish), mask, Gore-Tex gloves, and special boots consisting of rubber for the
feet and ankle and Gore-Tex around the legs. In addition, the head and chest were
cooled by frozen gel strips fixed in the cap and undershirt. In Experiment I,
five female adults took part, in a climate-chamber controlled at an ambient
temperature of 28 degrees C and a relative humidity of 60%. In Experiment II,
five farmers (one male and four female) were tested in an apple orchard in July,
August and September. The main results are summarized as follows: (1) change of
rectal temperature was inhibited more effectively in Type B in Experiment I, (2)
change of heart rate tended to be lower in Type B than in Type A in both
experiments, (3) salivary lactic acid concentration at the end of the first
exercise was significantly higher in Type A than in Type B in Experiment I, (4)
the number of contractions in the handgrip exercise which was performed
immediately after the third exercise, was significantly smaller in Type A than in
Type B in Experiment I, (5) subjective comfort sensation was significantly
improved in Type B in Experiments I and II. Thus, it was concluded that the newly
designed protective clothing could reduce thermal stress during the spraying of
pesticides in an apple orchard in summer.
PMID- 10787135
TI - Methylmercury exposure affects motor performance of a riverine population of the
Tapajos river, Brazilian Amazon.
AB - Gold mining and deforestation in the Brazilian Amazon are increasing mercury
pollution of the extensive water system, exposing riverine populations to organic
mercury through fish-eating. The aim of the present study was to evaluate the
effect of such exposure on motor performance. This cross-sectional study was
carried out in May 1996, in a village located on the banks of the Tapajos river
in the Amazonian Basin, Brazil. Information concerning sociodemographics, health,
smoking habits, alcohol drinking, dietary habits and work history were collected
using an interview-administered questionnaire. Mercury concentrations were
measured by cold vapor atomic absorption in blood and hair of each participant,
of whom those aged between 15 and 79 years were assessed for motor performance (n
= 84). Psychomotor performance was evaluated using the Santa Ana manual dexterity
test, the Grooved Pegboard Fine motor test and the fingertapping motor speed
test. Motor strength was measured by dynamometry for grip and pinch strength.
Following the exclusion of 16 persons for previous head injury, working with
mercury in the goldmining sites, or for diabetes, the relationship between
performance and bioindicators of mercury was examined using multivariate
statistical analyses, taking into account covariables. All participants in the
study reported eating fish, which comprised 61.8% of the total meals eaten during
the preceding week. The median hair total mercury concentration was 9 microg/g.
Organic mercury accounted for 94.4 = 1.9% of the total mercury levels.
Multivariate analysis of variance indicated that hair mercury was inversely
associated with overall performance on the psychomotor tests, while a tendency
was observed with blood mercury. Semipartial regression analyses showed that hair
total mercury accounted for 8% to 16% of the variance of psychomotor performance.
Neither hair nor blood total mercury was associated with the results of the
strength tests in women and men. Although dose-effect relationships were observed
in this cross-sectional study, they may reflect higher exposure levels in the
past. The findings of this study demonstrated neurobehavioral manifestations of
subtle neurotoxic effects on motor functions, associated with low-level
methylmercury exposure.
PMID- 10787136
TI - Miscarriages and stillbirths in women with a high intake of fish contaminated
with persistent organochlorine compounds.
AB - OBJECTIVES: The purpose of the present study was to assess the effect, on
miscarriages and stillbirths, of persistent organochlorine compounds (POC)
through dietary intake of fatty fish from the Baltic Sea. METHODS: Information on
miscarriages and stillbirths was collected retrospectively by a self-administered
questionnaire in a cohort of fishermen's wives from the Swedish east coast (by
the Baltic Sea) and in a referent cohort of west coast fishermen's wives. Current
fish consumption was used as a proxy for exposure within the east coast cohort.
RESULTS: No increase in miscarriages or stillbirths was found in the east coast
cohort compared with the west coast group, in fact a decrease in early
miscarriages was found (OR 0.48 [95% CI 0.26-0.92]). Moreover, no increase in
risk was found for current high consumers of fatty fish within the east coast
cohort. CONCLUSIONS: The present data provided no evidence that dietary POC
exposure increases miscarriage and stillbirth rates.
PMID- 10787137
TI - Dust exposure in Munich public transportation: a comprehensive 4-year survey in
buses and trams.
AB - OBJECTIVES: Published data obtained from outdoor stationary sampling stations
cannot be applied directly to the exposure situation in vehicles. The aim of this
study, therefore, was to assess the dust exposure relevant to passengers and
drivers in public buses and trams. METHOD: In the years 1993 to 1996, PM10
samples were taken during 201 journeys of typically 4 h duration on 14 routes
(nine bus routes, five tramways) which were representative for the overall Munich
transportation system with respect to area characteristics and traffic density.
The concentrations of the samples were compared with those collected at the same
time at sampling stations of the Bavarian State Office for Environmental
Protection (OEP). Dust exposure was continuously and synchronously recorded by
means of a tyndallometric device. Traffic and passenger density, weather
conditions, special events, etc. were noted by our personnel, travelling on every
journey. RESULTS: The average PM10 dust concentration for all rides was 155
microg/m3 (single journey max. 686 microg/m3, min. 13 microg/m3). Interior
concentrations were 1.7 to 4.0 times above those collected at the static outdoor
stations. We found only minor associations between dust concentrations and
traffic density or time of day. During several journeys continuous recording
disclosed anomalies, dependence on weather conditions and cyclic track
characteristics. CONCLUSIONS: Interior PM10 particulate concentrations were
comparable to those found elsewhere in truck drivers' cabs and are in the region
of German regulative limits established for the general population's long term
outdoor exposure. Indoor concentrations were well above the values found at
stationary outdoor stations. Additional continuous recording of dust
concentrations proved to be helpful in unveiling anomalies and dependencies on
external effectors.
PMID- 10787138
TI - Litigation and the Canadian Pap test: perspectives from a single-payer system.
PMID- 10787139
TI - Fine-needle aspiration cytology findings in 214 cases of nonparotid lesions of
the head.
AB - The use and limitations of fine-needle aspiration (FNA) of lesions of the parotid
gland are known, but those of nonparotid lesions of the head have been described
only sporadically. We conducted this study to evaluate the utility of FNA and to
analyze the causes of diagnostic discrepancies for these lesions. A total of
6,898 FNAs of different sites was performed at our institutions between January
1991-August 1998, and 214 (3.1%) of the cases were FNAs of nonparotid lesions of
the head. The most common diagnosis of nonparotid lesions was squamous-cell
carcinoma, in 22% (n = 48), and the most common site aspirated was the scalp, in
34% (n = 73). Lipomas and keratinous cysts comprised 5% (n = 9) of the total. A
statistical analysis was conducted on 98 paired cytology and histology (n = 83)
and cytology and flow cytometry (n = 15) specimens (70 malignant and 28 benign).
FNA recognized the malignant and benign nature of the lesion in 60 and 26 cases,
respectively with 86% sensitivity 93% specificity and 88% accuracy. Causes of
false-negative FNA diagnoses (n = 10) included sampling error (n = 6), bloody
smears with scant cellularity (n = 3), and bland cytomorphology (n = 1). Florid
granulation tissue and a mucocele of the tongue accounted for the two false
positive cases. We conclude that FNA is an effective tool for triage of surgery
candidates with nonparotid lesions of the head. Adequate samples with sufficient
cellularity are required for avoiding false-negative diagnoses. Occasionally,
tissue biopsy is needed for diagnosis of equivocal cases.
PMID- 10787140
TI - Pre- and postresection thoracic washings in non-small cell carcinoma of the lung:
a cytological study of 44 patients without pleural effusion.
AB - The presence of malignant pleural effusion in patients with non-small cell
bronchogenic cancer has a poor prognostic significance and is indicative of
advanced disease (T4, IIIB). The present study will investigate the role of
cytology and identify the various cellular components seen in thoracic washings,
in the absence of an effusion, and will identify the potential pitfalls in
diagnosing these specimens. The sensitivity, specificity, and positive and
negative predictive values will be determined, as well as the associated
predictive factors. From November 1996 to July 1997, 96 thoracic washings were
performed on 44 patients with non-small cell carcinoma of the lung prior to and
following resection. The specimens were processed routinely. To assess the false
negative or false-positive cases, all cases were rescreened and then correlated
with the surgical pathology. Seven (15.9%) patients had positive findings
detected on the pre- and/or postresection thoracic washings. One (2.3%) patient
had a negative preresection, but cytologically atypical cells were found on the
postresection. Thirty-six (81.8%) patients had negative pre- and postresection
thoracic washings. There were no false-positive diagnoses in the study; however,
two false-negative diagnoses were made. The finding of positive cytology in 7 of
44 (15.9%) patients appears significant. Thoracic washings may provide evidence
of cancer beyond the pleura in patients without pleural effusion which may be
indicative of advanced disease.
PMID- 10787141
TI - Successful grading of renal-cell carcinoma in fine-needle aspirates.
AB - Early-stage renal-cell carcinoma is more frequently diagnosed due to more
frequent use of advanced radiologic techniques. Partial nephrectomy may be
curative for small tumors and may sometimes be necessary if the opposite kidney
is functionally compromised. This therapeutic option is however not possible in
high-grade neoplasms. In the current study, we attempted to grade cases of renal
cell carcinoma on smears obtained from preoperative fine-needle aspirates (FNA).
Eighteen cases of histologically proven renal-cell carcinoma formed the basis of
this study. FNAs were performed prior to nephrectomy. FNA smears were blindly
reviewed, and the cases were evaluated for cellularity, nuclear to cytoplasmic
(N/C) ratios, nuclear pleomorphism, and the presence of naked nuclei and
prominent nucleoli; cases were graded according to the presence or absence of
these criteria and their combination. The cases were cytologically graded from
grade I-IV and then were given a low grade if the tumor was considered grade I or
II, or high grade if the tumor was considered grade III or IV. The histology of
the neoplasms was reviewed, and the tumors were graded according to the Fuhrman
nuclear grading system. Correlation between the cytologic and histologic grades
within the same histologic grade was seen in 13 of the 18 cases (72.2%). The
difference was no more than one grade for each discrepancy. When grading as high
or low grade was used, agreement was seen in 100% of the cases. The most reliable
cytologic features seen on cytology distinguishing low- from high-grade tumors
were the N/C ratio and the presence or absence of nucleoli. Pleomorphism, naked
nuclei, and increased cellularity were less distinguishing features. We conclude
that grading of renal-cell carcinoma can be reliably achieved in FNA material.
Preoperative FNAs can thus be performed on small renal neoplasms with subsequent
conservative treatment if the tumor proves to be low grade.
PMID- 10787142
TI - Cytology of columnar-cell variant of papillary thyroid carcinoma.
AB - Columnar cell variant of papillary carcinoma (CCV-PC) thyroid is a rare and
aggressive tumor composed of tall columnar cells that form papillae, glands and
solid structures. This paper describes fine needle aspiration (FNA) cytologic
features in a case of CCV-PC occurring in the right thyroid lobe of a 27-year-old
female. Smears showed tall columnar cells in monolayered, three-dimensional,
acinar and occasional papillary clusters. Nuclei were oval or elongated and
monomorphic. Nuclear pseudostratification, resembling that seen in respiratory
epithelial cells, was present in some of the cell clusters. Occasional cells
showed squamous or Hurthle cell metaplasia. Nuclear grooves and intranuclear
cytoplasmic inclusions were not seen. Sections of the right lobectomy specimen
showed an well-encapsulated CCV-PC with capsular and vascular permeation. Tall
cell variant of papillary carcinoma (TCV-PC) can be distinguished from CCV-PC by
the oxyphilia of the tumor cells and the absence of nuclear pseudostratification.
Colorectal and endometrial adenocarcinomas metastatic to the thyroid may be
difficult to distinguish from CCV-PC.
PMID- 10787143
TI - Cytologic demonstration of "dysplastic" follicular dendritic cells in a case of
hyaline-vascular Castleman's disease.
AB - Large atypical follicular dendritic cells, considered dysplastic by some authors,
were first described in association with Castleman's disease in 1991, but until
now there has been no cytologic account regarding these cells. We report the
cytologic and histologic findings of a case of hyaline-vascular Castleman's
disease associated with "dysplastic "follicular dendritic cells which presented
as a mediastinal mass in a young man. The presence of giant cells within the
preoperative fine-needle aspirate specimen caused initial diagnostic uncertainty
and their true nature was only confirmed retrospectively following application of
an immunostain for CD21 to direct smears. Awareness of "dysplastic" follicular
dendritic cells within aspirates of Castleman's disease will result in less
cytological confusion in the future and may help to avoid the possibility of
misdiagnosing Hodgkin's lymphoma which has certain cytologic similarities.
PMID- 10787144
TI - Fetal rhabdomyomatous nephroblastoma: diagnosis by fine-needle aspiration
cytology--a case report.
AB - The present report describes the case of a 21-mo-old boy with a fetal
rhabdomyomatous nephroblastoma (FRN) diagnosed by fine-needle aspiration cytology
(FNAC). The smears contained numerous isolated or clustered, deeply eosinophilic,
thin, elongated rhabdomyoblasts with oval nuclei. Some of these cells presented
cross-striations. Peculiar clusters of small, deeply eosinophilic, round cells
with and without rounded nuclei in a mosaic pattern were interpreted as
representing transversally oriented rhabdomyoblasts. Fetal rhabdomyoblasts were
by far the predominant type of cell. Histology of the surgical specimen proved
90% of the mass to be constituted of fetal rhadomyomatous tissue. Adequate
recognition of FRN is useful for the planning of treatment.
PMID- 10787146
TI - Malignant phyllodes tumor metastatic to the forearm: a case report.
AB - We describe the cytological features of a malignant phyllodes tumor, in a 40-yr
old female, that metastasized to the forearm, and we correlate these findings
with the criteria suggested by other authors for predicting the clinical and
metastatic behavior of this tumor. The diagnosis of metastasis was based on fine
needle aspiration (FNA) cytology. One year prior, the patient had undergone
mastectomy of the left breast for malignant phyllodes tumor, as proven by
histopathology. The patient then presented with right forearm swelling, 1 yr
later. FNA cytology was performed, and the diagnosis was metastatic malignant
phyllodes tumor. Histologic review of the breast tumor revealed stromal
overgrowth, which is the most important histologic criterion for predicting the
metastatic behavior of malignant phyllodes tumor as reported by some authors.
PMID- 10787145
TI - Fine-needle aspiration of a follicular dendritic-cell tumor: report of a case and
review of the literature.
AB - Follicular dendritic-cell tumors (FDCT) are rare neoplasms, well-characterized in
surgical pathology material. There are, however, few cytopathology reports. We
describe the fine-needle aspiration (FNA) findings of a histologically confirmed
FDCT. Conventional smears and a cell block showed large spindle to oval
neoplastic cells admixed with small mature lymphocytes. The neoplastic cells were
present mainly in small syncytial clusters. Immunostains for CD21 and CD35,
performed on the cell block, were positive in the neoplastic cells. The diagnosis
was fully confirmed by the presence of typical immunohistochemical and
ultrastructural features on the surgically removed tumor. The differential
diagnosis of FDCT is broad and includes other tumors characterized by an
admixture of large neoplastic cells and small mature lymphocytes, such as
thymomas, lymphoepithelioma-like carcinomas, and interdigitating dendritic-cell
tumors. It may not be possible to diagnose FDCT based on FNA material without the
use of immunocytochemical and electron microscopic studies. Certain
cytomorphological characteristics, however, might suggest its diagnosis and allow
the practicing cytopathologist to perform confirmatory studies.
PMID- 10787147
TI - A case of amelanotic spindle-cell melanoma presenting as metastases to breast and
axillary lymph node: diagnosis by FNA cytology.
AB - Metastatic neoplasms to the breast are relatively rare. Spindle-cell lesions of
the breast are also uncommon. Here we present a case of fine-needle aspiration
(FNA) of an amelanotic, spindle-cell melanoma metastatic to the breast and
axillary lymph node. The patient was a 47-yr-old female who presented with a
right breast mass, left axillary adenopathy, and a pigmented skin lesion on the
back. FNA of the right breast and left axilla showed malignant, nonpigmented
spindle cells that were weakly positive for HMB-45 on immunocytochemistry. The
skin biopsy showed a pigmented malignant melanoma with epithelioid features, and
also weak positivity for HMB-45. Although malignant melanoma is one of the more
common tumors to metastasize to the breast, this is the first known case that
showed exclusive spindle-cell morphology. History and physical examination were
crucial in making the correct FNA diagnosis. The cytologic differential diagnosis
of spindle-cell tumors of breast and the discordant morphology between the
primary and metastatic melanotic lesions observed in this case are discussed.
PMID- 10787148
TI - Fine-needle aspiration cytology of mesenchymal hamartoma of the liver.
AB - The cytologic appearance of mesenchymal hepatic hamartoma in a 2-yr-old boy is
described. Smears disclosed small groups and isolated, benign-appearing spindle
cells admixed with scarce amounts of myxoid stroma and normal ductal cells and
hepatocytes. Although the findings were nonspecific, cytology may rule out many
other diagnostic possibilities and increases the preoperative capacity of
clinical and image studies, leading to a more rational therapeutic decision.
PMID- 10787149
TI - Freeze-drying method for stable preservation in cellular specimens for the
detection of apoptotic cells.
AB - We describe a method of cytologic specimens for the detection of apoptotic cells
by immunostaining after long-term storage (>6 mo) using TdT-mediated dUTP-biotin
nick end labelling (TUNEL) technique. The application of the TUNEL method on
freeze-drying cellular sample will eliminate the need for fresh material and will
provide several advantages.
PMID- 10787150
TI - Processing of noninflammatory synovial fluids with hyaluronidase for cytospin
preparations improves the accuracy of differential counts.
AB - Differential leukocyte counts on noninflammatory synovial fluids (NISF) are not
widely reported or used in research, apparently due to technical difficulties
related to either high viscosity or low numbers of cells. We describe an
evaluation of a technique using hyaluronidase and cytospin preparations to study
NISF. Twenty-three consecutive synovial fluids (SF) with less than 2,000 white
blood cells (WBC)/mm3 were studied either by the usual smear of a single drop or
by adding two drops of hyaluronidase (150 USP units/ml) to 0.25 cc of SF and
cytocentrifuging at 800 rpm for 10 min. Both preparations were stained with
Wright's stain. Cytospin preparations gave better morphology, and in 22/23
specimens we could count 100 cells on one slide. Smeared preparations gave dark
cells and required 2-3 slides to count 100 cells. Differential counts on the
cytospin preparations consistently showed higher percentages of monocytes,
suggesting that these cells were underdetected and misinterpreted as lymphocytes
on the routine smears. Polymorphonuclear leukocytes (PMN) were significantly less
frequent (P 0.005) in osteoarthritis (OA) fluids than in the other diseases with
NISF. Relatively more PMN may suggest consideration of a diagnosis other than OA.
Cytospin preparations of hyaluronidase-treated NISF may open up an important area
for investigation of the role of SF cells in less inflammatory diseases.
PMID- 10787151
TI - Coexistence of carcinoma of the breast with microfilariasis.
PMID- 10787154
TI - Intensity of nest defence is related to offspring sex ratio in the great tit
Parus major.
AB - Nest-defence behaviour of passerines is a form of parental investment. Parents
are selected, therefore, to vary the intensity of their nest defence with respect
to the value of their offspring. Great tit, Parus major, males were tested for
their defence response to both a nest predator and playback of a great tit chick
distress call. The results from the two trials were similar; males gave more
alarm calls and made more perch changes if they had larger broods and if they had
a greater proportion of sons in their brood. This is the first evidence for a
relationship between nest-defence intensity and offspring sex ratio. Paternal
quality, size, age and condition, lay date and chick condition did not
significantly influence any of the measured nest-defence parameters.
PMID- 10787152
TI - C-erbB-2 expression and DNA ploidy in breast cancer on fine-needle aspiration
cytology material.
PMID- 10787153
TI - Sperm velocity and longevity trade off each other and influence fertilization in
the sea urchin Lytechinus variegatus.
AB - The theoretical prediction that fast sperm should be more effective at
fertilizing eggs has never been documented empirically. Interspecific comparisons
suggest an inverse relationship between sperm velocity and sperm longevity but
this trade-off has never been demonstrated within a species. Here I investigate
how sperm velocity and sperm longevity influence the patterns of fertilization in
the sea urchin Lytechinus variegatus. In the laboratory I examined 11 male female
pairs of sea urchins for variation in sperm velocity and sperm longevity, and
determined the correlations of these traits with the percentage of eggs
fertilized with serially diluted sperm. Males with faster sperm had higher rates
of fertilization than males with slower sperm. Within individual males, as sperm
aged they slowed down and showed a reduced percentage activity and lower rates of
fertilization. Across males, the average velocity of freshly spawned sperm was
inversely related to sperm longevity. These results establish the possibility
that sperm traits are adapted for varying conditions along a continuum from sperm
limitation to sperm competition.
PMID- 10787155
TI - Sex-ratio optimization with helpers at the nest.
AB - In many cooperatively breeding animals, offspring produced earlier in life assist
their parents in raising subsequent broods. Such helping behaviour is often
confined to offspring of one sex. Sex-allocation theory predicts that parents
overproduce offspring of the helping sex, but the expected degree of sex-ratio
bias was thought to depend on specific details of female and male life histories,
hampering empirical tests of the theory. Here we demonstrate the following two
theories. (i) If all parents produce the same sex ratio, the evolutionarily
stable sex ratio obeys a very simple rule that is valid for a general class of
life histories. The rule predicts that the expected sex-ratio bias depends on the
product of only two parameters which are relatively easily measured: the average
number of helping offspring per nest and the relative contribution to offspring
production per helper. (ii) If the benefit of helping varies between parents, and
parents facultatively adjust the sex ratio accordingly, then the population sex
ratio is not necessarily biased towards the helping sex. For example, in line
with empirical evidence, if helpers are produced under favourable conditions and
parents do not adjust their clutch size to the number of helpers, then a surplus
of the non-helping sex is expected.
PMID- 10787156
TI - Parentage, reproductive success and breeding behaviour in the greater horseshoe
bat (Rhinolophus ferrumequinum).
AB - Female greater horseshoe bats form maternity colonies each summer in order to
give birth and raise young. During the mating period, females visit males
occupying territorial sites, copulation takes place and sperm are stored until
ovulation occurs, normally in April. Using microsatellite markers and a
likelihood method of parentage analysis, we studied breeding behaviour and male
reproductive success over a five-year period in a population of bats in south
west Britain. Paternity was assigned with 80% confidence to 44% of young born in
five successive cohorts. While a small annual skew in male reproductive success
was detected, the variance increased over five years due to the repeated success
of a few individuals. Mating was polygynous, although some females gave birth to
offspring sired by the same male in separate years. Such repeated partnerships
probably result from fidelity for either mating sites or individuals or from
sperm competition. Females mated with males born both within and outside their
own natal colony; however, relatedness between parents was no less than the
average recorded for male female pairs. Gene flow between colonies is likely to
be primarily mediated by both female and male dispersal during the mating period
rather than more permanent movements.
PMID- 10787157
TI - Persistence of bat defence reactions in high Arctic moths (Lepidoptera).
AB - We investigated the bat defence reactions of three species of moths (Gynaephora
groenlandica, Gynaephora rossi (Lymantriidae) and Psychophora sabini
(Geometridae)) in the Canadian Arctic archipelago. Since these moths inhabit the
Arctic tundra and, therefore, are most probably spatially isolated from bats,
their hearing and associated defensive reactions are probably useless and would
therefore be expected to disappear with ongoing adaptation to Arctic conditions.
When exposed to bat-like ultrasound (26 kHz and 110 dB sound pressure level root
mean square at 1 m) flying male Gynaephora spp. always reacted defensively by
rapidly reversing their flight course. They could hear the sound and reacted at
least 15-25 m away. Psychophora sabini walking on a surface froze at distances of
at least 5-7 m from the sound source. However, two out of three individuals of
this species (all males) did not respond in any way to the sound while in flight.
Hence, we found evidence of degeneration of bat defence reactions, i.e.
adaptation to the bat-free environment, in P. sabini but not in Gynaephora spp.
Some Arctic moths (Gynaephora spp.) still possess defensive reactions against
bats, possibly because the selection pressure for the loss of the trait is such
that it declines only very slowly (perhaps by genetic drift; and there may not
have been enough time for the trait to disappear. One possible reason may be that
Arctic moths have long generation times.
PMID- 10787158
TI - Copulatory courtship and cryptic female choice in red flour beetles Tribolium
castaneum.
AB - Males of many animal species engage in courtship behaviours during and after
copulation that appear to be solely aimed at stimulating the female. It has been
suggested that these behaviours have evolved by cryptic female choice, whereby
females are thought to impose biases on male postmating paternity success. Males
of the red flour beetle Tribolium castaneum rub the lateral edges of the females'
elytra with their tarsi during copulation. We manipulated female perception of
this behaviour by tarsal ablation in males, thus preventing males from reaching
the edge of the female elytra with their manipulated legs, and by subsequently
performing a series of double-mating experiments where the copulatory behaviour
was quantified. We found a positive relationship between the intensity of the
copulatory courtship behaviour and relative fertilization success among
unmanipulated males. This pattern, however, was absent in manipulated males,
where female perception of male behaviour differed from that actually performed.
Thus, female perception of male copulatory courtship behaviour, rather than male
behaviour per se, apparently governs the fate of sperm competing over
fertilizations within the female, showing that copulatory courtship is under
selection by cryptic female choice.
PMID- 10787159
TI - Web tuning of an orb-web spider, Octonoba sybotides, regulates prey-catching
behaviour.
AB - An uloborid spider (Oclonoba sybotides constructs two types of web which are
distinguished by linear or spiral stabilimenta. Food-deprived spiders tend to
construct webs with spiral stabilimenta and food-satiated spiders tend to
construct webs with linear stabilimenta. I experimentally examined the influence
of web type on the speed of a spider's response to small and large flies. The
results indicated that web type rather than the spiders' energetic condition
influences the response speed to small or large Drosophila flies. I also examined
whether thread tension affects the response speed of spiders by increasing the
tension of the radial threads. The results showed that spiders on an expanded web
responded to small prey as quickly as spiders on webs with spiral stabilimenta.
The tension of the radial threads may be regulated by the degree of distortion of
the radial threads at the hub. O. sybotides seems to construct orb webs which
induce different responses for smaller, less-profitable prey according to its
energetic state. The spider appears to increase the tension of the radial threads
so that it can sense smaller prey better when hungry.
PMID- 10787160
TI - Sensory compensation and the detection of predators: the interaction between
chemical and visual information.
AB - Recent evidence suggests that environmental conditions may affect whether fishes
do or do not respond to the presence of chemical alarm cues in water. We present
a simple model which suggests that the combination of risk of predation and
information from other sources will determine when fishes should react to these
chemical cues. We tested this model with a laboratory experiment which
manipulated the risk of predation by altering the animals (hungry or well fed),
or their environment (presence or absence of cover). We also altered the
availability of visual information by manipulating the water clarity. Consistent
with our model, fishes were most likely to react to chemical alarm cues in the
absence of visual information and when the perceived risk of predation was high.
The manipulation of either parameter was able to extinguish this response.
PMID- 10787161
TI - Acoustic preference functions and song variability in the Hawaiian cricket
Laupala cerasina.
AB - Female preference functions for different sexual traits can differ significantly,
from 'unimodal' to 'open ended'. Through the study of acoustic communication in
anurans, several studies have reported an association between static
(stereotyped) traits versus dynamic (variable) traits and preference function
shape (unimodal versus open ended, respectively). Observing a similar pattern in
a phylogenetically independent group would suggest that deterministic forces have
caused a relationship between signal variability and preference function shape in
acoustic signalling systems. We examined this phenomenon in crickets, another
animal characterized by intersexual acoustic communication. We measured the
within-male variability for three acoustic features of the male calling song in
Laupala cerasina and the corresponding shape of the female preference function
for each of these features. We offer support for the generalization that open
ended preference functions correspond to relatively dynamic courtship traits and
unimodal preference functions correspond to relatively static courtship traits.
We discuss the evolutionary significance of these findings in the context of the
natural history of the Laupala species radiation.
PMID- 10787162
TI - A long photoperiod overrides non-photoperiodic factors in blue tits' timing of
reproduction.
AB - Endocrinological studies have contributed considerably to the development of
theory concerning the proximate aspects of the timing of reproduction. In non
domesticated, avian species, the relative importance of the photoperiodic and non
photoperiodic factors influencing later stages of the breeding cycle, such as the
onset of egg laying, remains unclear because egg laying is difficult to obtain
with captive populations and laboratory experiments of breeding are rarely
carried out in the framework of long-term field studies. We set up a special
experimental design such that captive Mediterranean blue tits (Parus caeruleus)
can breed with success in large outdoor aviaries at similar latitudes and
altitudes to their wild counterparts. Here we demonstrate experimentally that the
non-photoperiodic factors responsible for large and consistent differences in the
expression of natural breeding responses between three captive outdoor blue tit
populations are ignored during long-day treatment. Based on these findings, an
evolutionary explanation is provided for why the relative importance of the non
photoperiodic factors decreases with the progress of the season. The hypothesis
can explain observed maladapted breeding dates in free-living populations and
could possibly be used to increase the success of breeding programmes with some
endangered, captive, non-domesticated, photoperiodic species.
PMID- 10787163
TI - Individual state controls temperature dependence in a butterfly (Lasiommata
maera).
AB - In ectotherms there is typically a strong and positive correlation between growth
rate and ambient temperature when food is not limiting. However, the exact
relationship between growth rate and temperature varies among populations in many
species. As a consequence, it has been suggested that selection for a rapid
increase in growth rate with temperature should be stronger in populations
experiencing a high degree of time-stress, compared with populations experiencing
little time-stress. In the present study we take this adaptive hypothesis further
and investigate if variation in time-stress among individuals of a single
population may affect the relationship between growth rate and ambient
temperature. Time-stress was manipulated by rearing larvae of the butterfly
Lasiommata maera in different day-length regimes. The results show that
individuals experiencing a higher degree of time-stress increase their growth
rates more in higher temperatures compared with individuals under less time
stress. Hence, the adaptive hypothesis was supported and the relationship between
growth rate and temperature was highly state dependent. These findings may be of
general importance for understanding the evolution of life histories in seasonal
environments.
PMID- 10787165
TI - Effective population size may limit the power of laboratory experiments to
demonstrate sympatric and parapatric speciation.
AB - Laboratory experiments designed to elucidate the mechanisms of sympatric and
parapatric speciation may have been handicapped by too small population sizes,
although this possibility has seldom been discussed. In this paper we review the
published records of sympatric and parapatric speciation experiments to test the
relative importance of selection intensity applied, duration of experiment and
effective population size. Our results show that among these factors only
effective population size has had a general effect on the generation of
assortative mating. Reduced interbreeding is less likely to develop in small
populations where the selection process often seems to have been opposed by
inbreeding depression or loss of genetic variation. This study demonstrates that
the experimental evidence frequently used as an argument against sympatric and
parapatric speciation models is not as strong as previously believed.
PMID- 10787164
TI - Relationships between root density of the African grass Hyparrhenia diplandra and
nitrification at the decimetric scale: an inhibition-stimulation balance
hypothesis.
AB - Previous studies have shown that Lamto savannah exhibits two different types of
nitrogen cycle with high and low nitrification sites and suggested that the
perennial grass Hyparrhenia diplandra is responsible for this duality at a
subpopulation level, with one ecotype being thought to be able to inhibit
nitrification. The present work aimed to investigate the relationships between
nitrification and the roots of H. diplandra at two scales. (i) Site-scale
experiments gave new insight into the hypothesized control of nitrification by H.
diplandra tussocks: the two ecotypes exhibited opposite influences, inhibition in
a low nitrification site (A) and stimulation in a high nitrification site (B).
(ii) Decimetric-scale experiments demonstrated close negative or positive
relationships (in sites A or B, respectively) between the roots and nitrification
(in the 0-10 cm soil layer), showing an unexpectedly high sensitivity of the
nitrification process to root density. In both soils, the correlation between the
roots and nitrification decreased with depth and practically disappeared in the
20-30 cm soil layer (where the nitrification potential was found to be very low).
Therefore, the impact of H. diplandra on nitrification may be viewed as an
inhibition-stimulation balance.
PMID- 10787166
TI - Field data do not support a textbook example of convergent character
displacement.
AB - Experimental evidence supporting convergent character displacement is rare; only
one example exists and it is in the form of orientation and territory competition
experiments performed in the laboratory. However, outcomes of laboratory
experiments involving behaviour or competition can be artefacts of unnatural
conditions and, therefore, the results of the previous experiments supporting
convergent character displacement are equivocal. In this study, we re-examine the
evolution of melanic nuptial coloration in male three-spined stickleback
(Gasterosteus aculeatus) inhabiting the Chehalis River drainage in Washington
State. This novel nuptial coloration has been thought to have evolved in response
to competition for nesting territories with the co-distributed Olympic mudminnow
(Norzumbra hubbsi), which is also melanic and breeds at the same time. I found
that melanic stickleback males did not have an advantage over their red
counterparts from typical populations when competing for nesting territories with
Olympic mudminnows. Additionally competitive interactions between sticklebacks
and mudminnows were rare in both cage experiments and naturally breeding
sticklebacks. Finally, melanic coloration in the Chehalis populations did not
develop until males were parental, well after the hypothesized territory
establishment period. These results refute the only experimental support for
convergent character displacement and emphasize the importance of conducting
behavioural experiments and observations under natural conditions.
PMID- 10787167
TI - Phylogenetically patterned speciation rates and extinction risks change the loss
of evolutionary history during extinctions.
AB - If we are to plan conservation strategies that minimize the loss of evolutionary
history through human-caused extinctions, we must understand how this loss is
related to phylogenetic patterns in current extinction risks and past speciation
rates. Nee & May (1997, Science 278, 692-694) showed that for a randomly evolving
clade (i) a single round of random extinction removed relatively little
evolutionary history, and (ii) extinction management (choosing which taxa to
sacrifice) offered only marginal improvement. However, both speciation rates and
extinction risks vary across lineages within real clades. We simulated
evolutionary trees with phylogenetically patterned speciation rates and
extinction risks (closely related lineages having similar rates and risks) and
then subjected them to several biologically informed models of extinction.
Increasing speciation rate variation increases the extinction-management pay-off.
When extinction risks vary among lineages but are uncorrelated with speciation
rates, extinction removes more history (compared with random trees), but the
difference is small. When extinction risks vary and are correlated with
speciation rates, history loss can dramatically increase (negative correlation)
or decrease (positive correlation) with speciation rate variation. The loss of
evolutionary history via human-caused extinctions may therefore be more severe,
yet more manageable, than first suggested.
PMID- 10787169
TI - Least-inclusive taxonomic unit: a new taxonomic concept for biology.
AB - Phylogenetic taxonomy has been introduced as a replacement for the Linnaean
system. It differs from traditional nomenclature in defining taxon names with
reference to phylogenetic trees and in not employing ranks for supraspecific
taxa. However, 'species' are currently kept distinct. Within a system of
phylogenetic taxonomy we believe that taxon names should refer to monophyletic
groups only and that species should not be recognized as taxa. To distinguish the
smallest identified taxa, we here introduce the least-inclusive taxonomic unit
(LITU), which are differentiated from more inclusive taxa by initial lower-case
letters. LITUs imply nothing absolute about inclusiveness, only that subdivisions
are not presently recognized.
PMID- 10787168
TI - Estimating the time to extinction in an island population of song sparrows.
AB - We estimated and modelled how uncertainties in stochastic population dynamics and
biases in parameter estimates affect the accuracy of the projections of a small
island population of song sparrows which was enumerated every spring for 24
years. The estimate of the density regulation in a theta-logistic model (theta =
1.09 suggests that the dynamics are nearly logistic, with specific growth rate r1
= 0.99 and carrying capacity K = 41.54. The song sparrow population was strongly
influenced by demographic (sigma2(d) = 0.66) and environmental (sigma2(d) = 0.41)
stochasticity. Bootstrap replicates of the different parameters revealed that the
uncertainties in the estimates of the specific growth rate r1 and the density
regulation theta were larger than the uncertainties in the environmental variance
sigma2(e) and the carrying capacity K. We introduce the concept of the population
prediction interval (PPI), which is a stochastic interval which includes the
unknown population size with probability (1 - alpha). The width of the PPI
increased rapidly with time because of uncertainties in the estimates of density
regulation as well as demographic and environmental variance in the stochastic
population dynamics. Accepting a 10% probability of extinction within 100 years,
neglecting uncertainties in the parameters will lead to a 33% overestimation of
the time it takes for the extinction barrier (population size X = 1) to be
included into the PPI. This study shows that ignoring uncertainties in population
dynamics produces a substantial underestimation of the extinction risk.
PMID- 10787170
TI - Old and new players in the lipoprotein system.
PMID- 10787171
TI - Structure and function of apolipoprotein A-I and high-density lipoprotein.
AB - Structural biology and molecular modeling have provided intriguing insights into
the atomic details of the lipid-associated structure of the major protein
component of HDL, apo A-I. For the first time, an atomic resolution map is
available for future studies of the molecular interactions of HDL in such
biological processes as ABC1-regulated HDL assembly, LCAT activation, receptor
binding, reverse lipid transport and HDL heterogeneity. Within the context of
this paradigm, the current review summarizes the state of HDL research.
PMID- 10787172
TI - Cholesterol efflux regulatory protein, Tangier disease and familial high-density
lipoprotein deficiency.
AB - Cellular cholesterol efflux, by which cholesterol is transported from peripheral
cells to HDL acceptor molecules for transport to the liver, is the first step of
reverse cholesterol transport. Two genetic disorders, Tangier disease and some
cases of familial HDL deficiency, have defects of cellular cholesterol efflux.
The recent discovery of mutations in the ABC1 gene, which encodes the cholesterol
efflux regulatory protein, in both these disorders establishes cholesterol efflux
regulatory protein as a rate-limiting factor in reverse cholesterol transport.
PMID- 10787173
TI - The role of the high-density lipoprotein receptor SR-BI in cholesterol
metabolism.
AB - The HDL receptor scavenger receptor class B type I (SR-BI), which mediates
selective HDL cholesterol uptake, plays a role in murine HDL metabolism, reverse
cholesterol transport and whole-body cholesterol homeostasis. SR-BI is found in
the liver, where its expression is regulated by estrogen, dietary cholesterol and
fat, and controls murine plasma HDL cholesterol levels and bile cholesterol
secretion. SR-BI is also highly expressed in rodent steroidogenic cells, where it
facilitates cholesterol uptake for storage or steroid hormone synthesis and where
its expression is regulated by trophic hormones. The detailed mechanism(s)
underlying SR-BI-mediated selective cholesterol uptake have not yet been
elucidated. Further analysis of the molecular and cellular bases of SR-BI
regulation and function should provide new insights into the physiology and
pathophysiology of cholesterol metabolism.
PMID- 10787174
TI - Cubilin, a high-density lipoprotein receptor.
AB - The metabolism of HDL particles is a complex biological process involving various
regulating factors in plasma and different cellular receptors. In addition to the
well-established scavenger receptor BI-mediated selective HDL-cholesteryl ester
uptake in liver and steroidogenic tissues, evidence has been provided that HDL
also undergoes holoparticle endocytosis in different tissues. Recently, a novel
receptor expressed in various absorptive epithelia was disclosed as a high
affinity receptor for endocytosis of HDL and lipid-poor apolipoprotein AI. This
receptor, designated cubilin, may play an important role in the renal clearance
of filterable apolipoprotein AI/HDL and in the maternal-fetal transport of
cholesterol.
PMID- 10787175
TI - Endothelial lipase: a new member of the triglyceride lipase gene family.
AB - The triglyceride lipase gene family plays a central role in intestinal lipid
absorption, energy homeostasis, lipoprotein metabolism, and atherosclerosis. A
new member of this gene family, termed endothelial lipase, was recently reported.
The presence of key functional motifs, the endothelial synthesis, the enzymatic
profile, and the in-vivo metabolic effects of endothelial lipase suggest that,
like other members of this gene family, endothelial lipase may play a role in
energy delivery to tissues and in modulating lipoprotein metabolism, and could
impact on atherogenesis.
PMID- 10787176
TI - Transgenic animals with altered high-density lipoprotein composition and
functions.
AB - Our understanding of HDL metabolism in vivo has greatly advanced from studies
with transgenic animals. Interactions between HDL apolipoproteins, transfer
proteins, lipolytic enzymes and receptors modulate HDL size, particle number and
fractional catabolic rate. The protective effect of HDL on atherosclerosis
depends on the combined actions of HDL proteins and the metabolism of apo B
lipoproteins.
PMID- 10787177
TI - Structure and function of lecithin cholesterol acyl transferase: new insights
from structural predictions and animal models.
AB - The enzyme lecithin cholesterol acyl transferase is responsible for the synthesis
of most of the cholesteryl esters in plasma, and therefore plays a key role in
lipoprotein metabolism. The relationship between the structure and function of
lecithin cholesterol acyl transferase has been extensively studied in the past
years, and new data appeared in 1999 documenting the substrate specificity and
physiological role of lecithin cholesterol acyl transferase. The discovery of
natural mutants, together with the proposal of a three-dimensional model for the
enzyme, has provided new tools to unravel the function of specific residues of
lecithin cholesterol acyl transferase. The use of transgenic animals and the
production of knock-out lecithin cholesterol acyl transferase mice has further
contributed to the understanding of the lecithin cholesterol acyl transferase 'in
vivo' function. Evidence for a protective role of lecithin cholesterol acyl
transferase against the development of atherosclerosis through the hydrolysis of
oxidized lipids was recently proposed. Lecithin cholesterol acyl transferase
patterns in several pathologies were further clarified. These newer developments
are reviewed here.
PMID- 10787179
TI - Signalling pathways in vascular endothelium activated by shear stress: relevance
to atherosclerosis.
AB - Major advances in our understanding of how endothelial cells sense and respond to
haemodynamic forces and, more specifically, to fluid shear stress have been
achieved during the past 3 years. These include definition of potential shear
stress receptors and multiple signalling pathways that mediate shear stress
regulation of gene expression. A few studies have also pointed to the unique
effects of complex shear stress on endothelial activation, thus leading to better
understanding of the mechanisms that lead to the development of atherosclerosis.
PMID- 10787178
TI - Cellular signalling by lipoprotein receptors.
AB - Lipoprotein receptors are commonly thought merely to mediate the internalization
of lipoprotein particles or the exchange of lipids at the cell surface. Recent
findings have now implicated these multifunctional receptors in cellular
signalling mechanisms that extend beyond simple ligand endocytosis. By mediating
the cellular uptake of lipophilic vitamins and hormones, megalin, a member of the
LDL receptor gene family, regulates critical hormonal and metabolic processes.
Other members of the LDL receptor family interact with cytoplasmic adaptor and
scaffold proteins, which allows them to transmit signals directly across the
plasma membrane of the target cell. This sheds a new light on the emerging roles
of lipoprotein receptors in pathologic disease processes such as Alzheimer's
disease.
PMID- 10787181
TI - Bibliography. Current world literature. Genetics and molecular biology.
PMID- 10787180
TI - Recent advances in liver-directed gene therapy: implications for the treatment of
dyslipidemia.
AB - Somatic gene therapy for the treatment of dyslipidemia is an area of active
investigation. A substantial body of data indicates that the transfer of various
lipid-lowering genes to the liver is an effective method of restoring normal
plasma lipids in animal models of dyslipidemia. Most studies have used adenoviral
vectors because of their excellent gene-transfer efficiency. However, the first
and second-generation adenoviral vectors used in these experiments are highly
toxic and are associated with substantial morbidity and mortality. This article
reviews current data on the properties of two novel vectors, the adeno-associated
virus and the helper-dependent adenovirus that is devoid of all protein-encoding
genes. Each type of vector has its advantages and drawbacks. They appear to be
the most promising vectors to date for liver-directed gene transfer in the
treatment of dyslipidemia.
PMID- 10787182
TI - Nutrition and therapeutics.
PMID- 10787184
TI - Lipid metabolism.
PMID- 10787185
TI - Hyperlipidaemia and cardiovascular disease.
PMID- 10787183
TI - Genetics and molecular biology.
PMID- 10787186
TI - Atherosclerosis: cell biology and lipoproteins.
PMID- 10787187
TI - Therapy and clinical trials.
PMID- 10787188
TI - The changing role of scintigraphy in the evaluation of thyroid nodules.
AB - Nodular thyroid disease is common. Most nodules are asymptomatic and benign, but
some are malignant. Fine needle aspiration (FNA) biopsy should be the cornerstone
of the evaluation of thyroid nodules. Radionuclide scans and other imaging
procedures should be considered adjunctive tests and should not be performed
until after determination of thyroid function and results of cytology are
available.
PMID- 10787189
TI - Therapeutic options in the management of toxic and nontoxic nodular goiter.
AB - Nodular goiter is present in 500 to 600 million people and is usually secondary
to endemic iodine deficiency. Despite adequate iodine intake, 4% to 6% of
American adults are goitrous. Sporadic nodular goiter ensues from the natural
heterogeneity of thyroid follicular cells, which, when amplified by yet
unidentified trophic stimuli, results in episodes of proliferating, rapidly
dividing micronodules. The initial small diffuse goiter evolves into a
multinodular goiter (MNG) with 1 or more dominant nodules that may or may not be
autonomous. An autonomous functioning thyroid adenoma (AFTA) usually possesses a
somatic gain-of-function mutation of the thyrotropin (TSH) receptor associated
with rapid growth, hemorrhagic necrosis, and reparative fibrosis that accentuate
goiter nodularity. Diagnostic evaluation consists of patient history and physical
examination, serum TSH determination, free thyroxine and free triiodothyronine
measurements, and imaging studies assessing goiter function, size, and anatomy.
If treatment is required, L-thyroxine, thionamides, surgery, radioiodine (I-131),
and percutaneous ethanol injection (PEI) are effective in selected patients. In
euthyroid patients, L-thyroxine reduces goiter size in some patients, but
continued therapy is required to prevent regrowth. Thionamides control the
hyperthyroidism of toxic nodular goiter in preparation for more definitive
therapy, but are rarely used long term. Surgery and I-131 are most commonly
selected for definitive therapy for the toxic AFTA, and the toxic or euthyroid
MNG, but PEI is effective in selected toxic AFTAs.
PMID- 10787190
TI - Recombinant thyrotropin versus thyroid hormone withdrawal in evaluating patients
with thyroid carcinoma.
AB - Patients with previously treated thyroid carcinoma require lifelong monitoring
for recurrent disease. Two diagnostic tests that play a central role in follow-up
of these patients--radioiodine whole body scanning and serum thyroglobulin
measurement--are most accurate during thyroid-stimulating hormone (TSH)
stimulation. Temporary discontinuation of thyroid hormone therapy was previously
the sole effective approach for TSH-stimulated testing. However, hormone
withdrawal was associated with the morbidity of hypothyroidism and occasional
tumor progression. The introduction of recombinant TSH (rTSH)-stimulated testing
offers an alternative therapy. Recent clinical trials have shown that the
sensitivity of combined rTSH-stimulated radioiodine scanning and serum
thyroglobulin measurement has equivalent sensitivity to testing after thyroid
hormone withdrawal. Furthermore, measurement of the rTSH-stimulated thyroglobulin
concentration is a more sensitive way to detect residual thyroid cancer or normal
tissue than thyroglobulin measurement on thyroid hormone therapy alone. The
results of these trials are reviewed and strategies for implementing rTSH
mediated testing are presented.
PMID- 10787191
TI - Treating the patient with differentiated thyroid cancer with thyroglobulin
positive iodine-131 diagnostic scan-negative metastases: including comments on
the role of serum thyroglobulin monitoring in tumor surveillance.
AB - Differentiated thyroid cancer (DTC) patients, especially the 10% to 15% at high
risk of cancer-related death, should have long-term monitoring for detection of
recurrence or metastasis. Conventional radiologic and ultrasonographic imaging is
useful for localization of recurrent or persistent disease. For patients who have
had ablation of residual thyroid tissue, measurement of serum thyroglobulin (Tg)
levels and radioactive iodine (RAI) imaging provide highly sensitive tools for
early detection. Serum Tg is reliable only in the absence of Tg autoantibodies.
Sensitivity increases with TSH stimulation, either by withdrawal of thyroxine
(T4) therapy, or administration of recombinant TSH (rTSH). In some patients,
serum Tg levels are positive but the RAI whole body scan (WBS) is negative. In
these patients, either the recurrent tumor is too small and below the sensitivity
of the diagnostic scan, or there is a dissociation between Tg synthesis and the
iodine-trapping mechanism. Recent literature suggests that empiric high-dose RAI
therapy of Tg-positive diagnostic scan-negative patients may result in a high
rate of visualization of uptake in posttherapy scans (PTS). Evidence for
subsequent improvement of parameters of disease activity has also been presented.
Almost all such reported cases had micrometastases that were not visualized by
conventional imaging. In our experience, aggressive macrometastases with negative
diagnostic WBS do not show significant uptake after therapeutic doses of RAI. The
small size of micrometastases in the first group of patients and a possible
defect of the iodine-trapping mechanism in the second group may explain this
apparent discrepancy. Based on presently available information, a generalized
recommendation for RAI therapy of Tg-positive, diagnostic scan-negative patients
should await further studies. Meanwhile, in some high-risk patients, in the
absence of alternative therapies, empiric RAI therapy is justified.
PMID- 10787192
TI - Artifacts, anatomical and physiological variants, and unrelated diseases that
might cause false-positive whole-body 131-I scans in patients with thyroid
cancer.
AB - The whole body 131-I scan remains an important component in the postoperative
treatment of patients with well-differentiated thyroid cancer. Because normal
thyroid tissue remnants and residual or metastatic foci of well-differentiated
thyroid cancer have the unique ability to concentrate, organify, and store 131-I,
the whole body scan provides a depiction of those tissues that can be ablated
with therapeutic doses of 131-I. Over time, it has become obvious that the whole
body scan may also reveal foci of 131-i uptake owing to a wide variety of other
causes. We provide a detailed pathophysiological classification of the artifacts,
anatomic and physiological variants, and nonthyroidal diseases that may give rise
to false-positive whole body scans in postoperative patients with thyroid cancer.
These include ectopic foci of normal thyroid tissue; nonthyroidal physiological
sites (eg, choroid plexus, salivary glands, gastric mucosa, urinary tract);
contamination by physiological sections; ectopic gastric mucosa; other
gastrointestinal abnormalities; urinary tract abnormalities; mammary
abnormalities; serous cavities and cysts; inflammation and infection;
nonthyroidal neoplasms; and currently unexplained causes. This article also
provides a detailed review of the widely scattered English language literature in
which these phenomena were originally described.
PMID- 10787193
TI - The Chernobyl accident and its consequences: update at the millennium.
AB - A marked increase in the incidence of papillary thyroid cancer in children has
been documented in regions of the former Soviet Union most heavily contaminated
by radioactive fallout from the Chernobyl nuclear power plant accident in April
1986. Accumulation of radioactive iodines by normal iodine trapping mechanisms
resulted in significant radiation doses to the thyroid gland. Although it has
long been known that thyroidal radiation resulted in nuclear and chromosomal
abnormalities visible by light microscopy, modern molecular biology techniques
are beginning to identify much smaller alterations in chromosomal coding
sequences that are associated with malignant transformation. Although stable
chromosomal abnormalities can be detected in Chernobyl-associated thyroid
cancers, they are much less prevalent than in thyroid cancers developing after
external beam irradiation. However, several unique chromosomal breakpoints have
been described in radiation-associated thyroid cancers that are not commonly
found in spontaneously occurring thyroid cancer. Furthermore, activation of
specific subtypes of the ret/PTC tyrosine kinase oncogene appears to be more
common in radiation-associated thyroid cancers than in spontaneous thyroid
cancers. In summary, thyroid cancers developing in the aftermath of the Chernobyl
accident provide a unique opportunity to search for chromosomal abnormalities
that may be specific for radiation-induced thyroid cancer.
PMID- 10787194
TI - Continually rising renogram without imaging of collecting system (parenchymal
renal retention).
PMID- 10787195
TI - Symmetrically increased uptake of Ga-67 citrate in the breasts: a patient with
liver cirrhosis.
PMID- 10787196
TI - Disparate results between I-131 and Tc-99m pertechnetate owing to administration
of iodine-containing radiographic contrast material.
PMID- 10787197
TI - Opportunity and responsibility: SCVIR's role with uterine artery embolization.
Society of Cardiovascular & Interventional Radiology.
PMID- 10787198
TI - Evolving strategies for thrombolytic therapy of peripheral vascular occlusion.
PMID- 10787199
TI - Endovascular treatment of iliac limb stenoses or occlusions in 31 patients
treated with the ancure endograft.
AB - PURPOSE: The authors report their experience with treatment of iliac limb
complications in patients treated with the Ancure endograft with Wallstents to
provide additional support and thrombolysis when needed. MATERIALS AND METHODS:
From February 1996 to October 1999, 88 patients were treated for abdominal aortic
aneurysm with use of the Ancure endograft. Of the 88 devices used, 20 were tube
grafts and the remaining 68 devices had a total of 130 iliac limbs (bifurcated, n
= 62; aortoiliac, n = 6). After graft deployment, all patients underwent
intraoperative aortography; since July 1997, intravascular ultrasound (IVUS) has
also been used. RESULTS: Thirty-one patients (46%) required treatment of 47 (36%)
limbs with Wallstents. Graft narrowing was observed in 41 limbs (27 patients)
with IVUS immediately after graft deployment. All were successfully treated with
placement of Wallstents. Before routine use of intraoperative IVUS, three
patients presented between 2 and 6 weeks postoperatively with iliac limb
thrombosis. All three limbs were successfully treated with thrombolysis and
Wallstent placement to correct the underlying iliac problem. Additionally, two
contralateral limbs in these three patients were also noted to have stenosis and
were treated with use of Wallstents. The last patient required placement of a
Wallstent to treat stenosis of surgical anastomosis of the iliac limb of an
aortoiliac endograft at 3 days. All Wallstent-reinforced Ancure endografts
remained patent from 1 to 36 months (mean, 14 months). CONCLUSION: After
placement of an Ancure bifurcated or aortoiliac endograft, iliac limb stenosis is
easily detected with use of intraoperative IVUS. Such complications can be safely
corrected with Wallstent placement. Postoperative limb occlusion at the authors'
institution has been eliminated with such intervention.
PMID- 10787200
TI - Endovascular repair of the abdominal aortic aneurysm with the ancure endograft:
CT follow-up of perigraft flow and aneurysm size at 6 months.
AB - PURPOSE: Perigraft flow--flow outside the graft lumen but contained within the
abdominal aortic aneurysm (AAA)--is a potential complication after endovascular
repair of AAA. Such flow may permit AAA growth and rupture. The purpose of this
study is to evaluate with computed tomography (CT) the rate of spontaneous
closure of perigraft flow and the effect of persistent flow on AAA diameter.
MATERIALS AND METHODS: During a 30-month period, the authors evaluated all CT
scans in 50 patients who underwent AAA repair using the Ancure endograft system.
CT was performed at discharge, 6, 12, and 24 months, and at 3 months if there was
perigraft flow at discharge. Scans were reviewed for the presence, size, and
location of perigraft flow, and measurement of AAA diameter. Transcatheter
embolization was performed on those patients with persistent leak at 6 months.
RESULTS: Sixteen (32%) of 50 patients demonstrated perigraft flow on CT performed
within 72 hours of placement. Resolution of perigraft flow by 6 months was found
in nine (56%) of the 16 patients, in whom AAA size had decreased in five, had
increased in none, and was unchanged in four. Seven patients had persistent leaks
at 6-month CT; AAA size had decreased in one, had increased in one, and was
unchanged in five. In 34 patients without leaks, AAA size had decreased in nine,
had increased in one, and was unchanged on 24. There was no statistically
significant difference for the relationship between resolution or persistence of
perigraft flow and subsequent course of AAA diameter (P = .16). CONCLUSIONS:
Although perigraft flow is frequently seen (32%) early after repair of AAA with
the Ancure system, spontaneous resolution by 6 months occurs in 56% of cases. AAA
size decreased in a larger percentage of patients in whom perigraft leak was
absent or resolved by 6 months compared with those in whom perigraft leak
persisted at 6 months.
PMID- 10787202
TI - Direct graft puncture with use of a crossed catheter technique for thrombolysis
of peripheral bypass grafts.
AB - PURPOSE: To determine the efficacy and safety of direct graft puncture of
peripheral arterial bypass grafts with placement of retrograde and antegrade
catheters within the graft for thrombolytic therapy. This study also evaluated
potential clinical benefit to patients. MATERIALS AND METHODS: A retrospective
study was performed on 19 patients with 24 peripheral bypass grafts and lower
extremity ischemia of less than 1 month duration. Thrombolysis was performed with
a continuous high-dose infusion of urokinase. Successful lysis was defined as
greater than 95% clot dissolution with antegrade flow within the graft. RESULTS:
Technical success was achieved in 17 of 19 patients (89%). The complexity of
operative intervention was diminished in 12 of 19 patients (63%). The major
complication rate (16%) was significantly higher and, therefore, this technique
has a role for patients in whom traditional access is not optimal, such as in
those in whom access cannot be achieved or in those with long bypass grafts.
CONCLUSION: Direct graft puncture with placement of catheters across the proximal
and distal anastomoses of bypass grafts is a safe method of access, with a major
complication rate similar to conventional access techniques. This mode of graft
access demonstrates efficacious thrombolysis and acts as a conduit for ancillary
procedures.
PMID- 10787201
TI - Accuracy of CO2 angiography in vessel diameter assessment: a comparative study of
CO2 versus iodinated contrast material in an aortoiliac flow model.
AB - PURPOSE: Precise vessel sizing prior to endovascular intervention is critical to
achievement of technical success. Diameter measurements obtained with CO2 and
iodinated contrast material in an aortoiliac flow model were compared. MATERIALS
AND METHODS: Aortoiliac flow was simulated in a compliant, silicone elastomer
phantom of the aortoiliac system using an autoperfusion pump (flow volume,
approximately 1100 mL/min; mean arterial pressure, 70-80 mm Hg at 80-90
cycles/minute) and a glycerol solution (40% by weight; viscosity 3.7 centipoise
at 20 degrees C). Digital subtraction angiography was performed with the phantom
in the anteroposterior (AP) plane and in three oblique planes with both CO2 and
iodinated contrast material. Five sets of images for both CO2 and iodinated
contrast material were obtained for each projection. Two readers independently
performed vessel diameter measurements at seven sites (distal abdominal aorta,
bilateral proximal and distal common iliac, and mid-external iliac arteries). The
model was then evaluated with intravascular ultrasound (IVUS) using a 20-MHz
imaging catheter. Actual diameter measurements were taken from the inner wall to
inner wall in orthogonal planes at the same locations within the model, as
described previously. Analysis was performed to determine local difference in
measurements (t tests), difference when compared to the standard AP projection
with iodinated contrast material (Dunnett's test) and inter-reader variability
(Pitman's test). RESULTS: The contralateral iliac vessel segment did not opacify
when imaging with CO2 in the 45 degrees obliquities; thus, 22 of 28 sites were
available for comparison. At 18 of 22 (81.8%) sites, there was significant
difference in vessel measurements (P < .01), with CO2 yielding a significantly
larger diameter at 17 of 22 (77.3%) of the sites. The difference in mean diameter
ranged from -1.28 to 4.47 mm. With use of the AP iodinated contrast material run
as the standard, there were significant differences (P < .05) in vessel diameter
at 17 of 22 (77.3%) and four of 21 (19%) sites for CO2 and iodinated contrast
material respectively, with CO2 tending toward greater diameter measurements.
Significant differences (P < .05) in variance between the two readers were
present but occurred primarily with CO2 in the AP projection and iodinated
contrast material in the 45 degrees left obliquity. With use of IVUS as the
standard, there were significant differences (P < .05) in the measured vessel
diameters with CO2 at nine of 22 (40.9%) of the sites and with iodinated contrast
material at 17 of 28 (60.7%) of the sites. Of the measurements made with CO2,
seven of nine (77.8%) of the measurements were of larger diameter than those
obtained with IVUS. By contrast, of the measurements made with iodinated contrast
material angiography, IVUS measured larger diameters in 16 of 17 (94.1%).
CONCLUSION: CO2 angiography consistently yielded significantly larger vessel
measurements when compared to both iodinated contrast angiography and WVUS. These
results have important implications in regards to planning intervention based
solely on CO2 angiography. Further evaluation is needed before recommending CO2
for vessel sizing in clinical practice.
PMID- 10787203
TI - Hepatic artery embolization: factors predisposing to postembolization pain and
nausea.
AB - PURPOSE: Analysis of preprocedural factors that may be helpful in predicting the
severity of pain and nausea after hepatic arterial embolization (HAE) for liver
neoplasms. MATERIALS AND METHODS: During a 2-year period, 62 patients (33 men, 29
women) underwent 130 palliative lobar HAEs for unresectable liver neoplasms. The
hepatic lobe was embolized with 150-250-microm polyvinyl alcohol particulates
with or without lipiodol and/or chemotherapeutic agents. Postembolization pain
was rated at rest and during movement with use of an 11-point verbal pain scale,
and postembolization nausea was assessed with use of a four-point verbal scale,
each at two separate time periods. Daily morphine use was also recorded. Primary
analysis was made using the first embolization procedure. One-way analysis of
variance and Spearman correlation coefficients were used to identify associated
predictors. Plots of the outcomes versus the pre-embolization liver function
tests and sensitivities and specificities were used to identify the strength of
the associations for prediction purposes. A secondary analysis was performed in
patients who underwent multiple embolizations. RESULTS: No strong categorical
predictors were found from the ANOVA on the severity of postembolization pain or
nausea. There were significant (P < .05) associations between the pre
embolization liver function tests and the pain outcomes only. However, while
these laboratory values demonstrate strong associations with resultant pain, they
are not strong predictors of pain and morphine requirements for any individual
patient. The morphine requirements were highly associated (P < .0001) with the
pain scores at rest and with movement. The authors did not find significant
differences on any of the pain outcomes or morphine requirements between the
first and second embolizations. CONCLUSION: Laboratory values and patient age are
not predictors for the severity of postembolization pain and nausea.
Postembolization pain is a significant complication and poses a continuing
challenge to the physician with regards to patient management.
PMID- 10787204
TI - US-guided percutaneous thrombin injection: a new method of repair of superficial
temporal artery pseudoaneurysm.
PMID- 10787205
TI - Endovascular treatment of an unusual arterioportal fistula caused by the rupture
of a giant hepatic artery aneurysm into the superior mesenteric vein in Behcet
disease.
PMID- 10787206
TI - Percutaneous thrombin injection of splanchnic artery aneurysms: two case reports.
PMID- 10787207
TI - US-guided percutaneous catheter drainage of parotid abscesses.
PMID- 10787208
TI - Comparison of C-arm CT fluoroscopy and conventional fluoroscopy for percutaneous
biliary drainage procedures.
AB - PURPOSE: To conduct a prospective randomized evaluation of C-arm computed
tomography (CT) fluoroscopy for external biliary drainage procedures in
comparison with conventional fluoroscopic guidance to reduce the number of
transhepatic punctures as a primary endpoint. MATERIALS AND METHODS: In 18
patients with biliary obstructions, 20 external percutaneous biliary drainage
procedures were prospectively performed with use of either C-arm CT fluoroscopy
or conventional fluoroscopy alone. The number of hepatic punctures, procedure
time, and fluoroscopy time, were analyzed separately for both methods. RESULTS: C
arm CT fluoroscopy resulted in a reduced number of transhepatic punctures, with
decreased procedure and fluoroscopy times (P < .05; t test). When compared with
conventional external biliary drainage procedures, a mean of 1.8+/-1 versus 4.8+/
2.8 hepatic punctures at a fluoroscopy time of 3.4+/-1.5 versus 11.4+/-7.4
minutes was required for C-arm CT fluoroscopy, while procedure times were 11+/
3.6 versus 16.2+/-9.3 minutes. CONCLUSIONS: C-arm CT fluoroscopy is associated
with decreased procedure and fluoroscopy times, while fewer transhepatic
punctures are required to establish external biliary drainage.
PMID- 10787209
TI - Assessment of a polyester-covered nitinol stent in an atherosclerotic swine
model.
AB - PURPOSE: To evaluate the short-term patency and healing characteristics of the
Cragg EndoPro covered stent in an atherosclerotic model as one of the Food and
Drug Administration requirements before possible approval of the device for human
use in the United States. MATERIALS AND METHODS: Seventeen self-expanding stent
grafts were placed in the aorta and right and left iliac arteries of six Yucatan
microswine exposed to a regimen of accelerated atherosclerosis. The stent-grafts
were constructed from nitinol wire formed into a tubular zigzag configuration.
The stent frame was covered by a thin woven polyester fabric tube, with medium
permeability, available in multiple diameters and lengths. The animals were
killed at 24 hours, 3 months, and 6 months. Assessment was done by angiography
and histology. RESULTS: All stents were patent immediately after deployment. Two
stents were occluded at follow-up, indicating an 88% patency rate. Minor lumen
narrowing was found at the follow-up intervals. Histologic examination revealed a
mixture of mature and immature endothelial cells lining both the native and
stented regions in all vessels examined. The new endoluminal surface was composed
primarily of fibrocollagen and elastic fibers and smooth muscle cells. Intimal
thickness was inversely correlated to medial thickness. Medial compression with
atrophy was observed routinely with rare necrosis. Complete tissue ingrowth was
seen by 3 months. The degree of vascular inflammation increased over time, as
well as the foreign body giant cell reaction to the polyester fabric. CONCLUSION:
The patency rate does not appear to be better than that with angioplasty or
noncovered stent placement in the studied time frame. The progressive vascular
inflammatory changes noted should be further investigated in longer-term animal
trials to ensure its safety in humans because this device is meant to be
permanent.
PMID- 10787211
TI - Pharmacomechanical thrombolysis with use of the brush catheter in canine
thrombosed femoropopliteal arterial PTFE bypass grafts.
AB - PURPOSE: To assess the efficacy, acute endothelial changes, and distal arterial
emboli after use of the Cragg thrombolytic brush catheter in mature thrombosed
polytetrafluoroethylene (PTFE) femoropopliteal arterial grafts in canines.
MATERIALS AND METHODS: PTFE femoropopliteal arterial grafts were implanted in 10
canines and were allowed to mature for approximately 4 weeks. The grafts were
thrombosed by mechanical means and allowed to remain thrombosed for 24-72 hours.
Through a left carotid cut-down, standard Seldinger arterial puncture was
performed, followed by catheterization of the thrombosed graft. A soft, low
speed, brush (6 mm in diameter) aided by preprocedure pulse-spray urokinase
infusion was utilized for thrombolysis. The native vessels, just proximal and
distal to the anastomosis, were evaluated microscopically for endothelial damage.
Arteriography was used for assessment of distal embolus. RESULTS: All grafts were
successfully thrombosed before thrombolysis. One graft could not be traversed
with a wire and catheter and was, therefore, not treated. Immediate preprocedure
pulse-spray urokinase infusion in the remaining nine grafts did not reconstitute
antegrade flow in any instance and left significant amounts of residual thrombus
in all treated grafts. Mechanical brush thrombolysis reconstituted antegrade flow
in all nine treated grafts and complete graft thrombolysis was obtained in most.
This was accomplished in a mean time of less than 4 minutes. Emboli were noted
angiographically in 67% of cases. Histologic studies showed vessel wall damage
limited to the intima or media in 67% of anastomoses. CONCLUSION: This method
offers a simple and rapid means of recanalizing thrombosed PTFE femoropopliteal
arterial grafts in the studied model. This technique provides a means of rapidly
"debulking" most intragraft thrombi. This may result in a shorter course of
thrombolytic infusion. Potential benefits may include shortening the total
treatment time and decreasing morbidity and cost associated with percutaneous
thrombolysis. The occurrence of distal emboli in a majority of cases is a
concerning limitation of this technique.
PMID- 10787210
TI - Comparison of two stent-grafts with different porosity: in vivo studies in a
sheep model.
AB - PURPOSE: To compare two stent-grafts with a polyurethane-carbonate (PUC) polymer
lining of different pore size and water permeability in the iliac arteries of
sheep. MATERIALS AND METHODS: Two stent-grafts with an inner PUC-lining of normal
and low water permeability (normal, 1,200 mL/min/cm2; low, 280 mL/min/cm2;
pressure gradient, 20 mm Hg) were implanted in each of 16 sheep. Hoop strength
was two times higher in low-permeable than in normal-permeable stent-grafts.
Patency was monitored with use of angiography and intravascular ultrasound (IVUS)
after 1, 3, and 6 months. The sheep were killed after 1 or 6 months. Specimens
were studied histologically. IVUS and histologic data were analyzed
statistically. RESULTS: IVUS measurements showed a wider patent lumen of the low-
compared to the normal-permeable prostheses at all time points (P < .03). This is
likely due to the greater hoop strength of the low-permeable stent-graft. After 1
month, both types of prostheses demonstrated complete transprosthetic tissue
penetration and were covered with neointima and endothelium. The neointimal area
was greater in low- than in normal-permeable stent-grafts (1 month, P < .005; 6
months, P < .03). CONCLUSIONS: Presumably, the higher permeability of the normal
permeable stent-grafts led to the reduced neointimal area by improving
transprosthetic capillary ingrowth and endothelialization.
PMID- 10787212
TI - An agenda for research into uterine artery embolization: results of an expert
panel conference.
AB - PURPOSE: To develop a research agenda for uterine artery embolization (UAE) for
the treatment of symptomatic leiomyomata. MATERIALS AND METHODS: An expert panel
was convened to examine data and develop a consensus for UAE research. Panelists
reviewed data from articles about UAE and data on hysterectomy and myomectomy,
which were abstracted into evidence tables. A modified Delphi process was used to
rate the importance of measuring specific outcomes and a nominal group process
was used to develop ideas for study designs. RESULTS: Panelists agreed that UAE
studies would have to examine certain key measures. Outcomes identified as either
"important to measure" or "essential to measure" were death, reoperation,
operative injury, menorrhagia, premature menopause, recurrence of myomata, and
satisfaction. The panel proposed four areas for research: randomized trial,
prospective registry, disease-specific quality-of-life instrument, and cost
analysis. CONCLUSIONS: Symptomatic uterine leiomyomata are a major health concern
for women. New techniques that promise to provide symptom relief deserve careful
consideration. Traditionally, surgical procedures have been poorly studied until
after they have been widely used. If the process described in this article can
guide the acquisition of knowledge in this field, it may serve as a model for
evaluating other new technologies before they become widely adopted.
PMID- 10787213
TI - SCVIR annual meeting film panel session: diagnosis and discussion of case 1.
PMID- 10787214
TI - SCVIR annual meeting film panel session: diagnosis and discussion of case 2.
PMID- 10787215
TI - SCVIR annual meeting film panel session: diagnosis and discussion of case 3.
PMID- 10787216
TI - SCVIR annual meeting film panel session: diagnosis and discussion of case 4.
PMID- 10787218
TI - Cloning and the politics of women's health.
PMID- 10787217
TI - Ovarian artery supply of uterine fibroid.
PMID- 10787219
TI - Toward optimal health: the experts respond to the art of diagnosis. Interview by
Jodi Godfrey Meisler.
PMID- 10787220
TI - Should women at increased risk for breast and ovarian cancer be randomized to
prophylactic surgery? An ethical and empirical assessment.
AB - More information is needed about the relative effectiveness of prophylactic
surgery, chemoprevention, and surveillance in reducing breast and ovarian cancer
risk in women with an inherited susceptibility mutation. We assessed practical
and ethical barriers to conducting randomized clinical trials (RCTs) to compare
preventive interventions for breast and ovarian cancer. Eighty-seven at-risk
women who attended an education and counseling session about BRCA1/2 testing were
asked about their willingness to participate in hypothetical research studies for
breast and ovarian cancer risk reduction. In addition, 247 Maryland physicians
from five specialties completed a mail survey including a question about their
likelihood of recommending RCT participation to an at-risk woman. Nineteen
percent of at-risk women reported willingness to participate in a hypothetical
RCT for breast cancer risk reduction and 17% for ovarian cancer risk reduction.
Women with children and women likely to have a prophylactic mastectomy if found
to have a susceptibility mutation were significantly more willing to participate
in an RCT. A majority of women would be willing to participate in nonrandomized
trials or registries. Fifty-two percent of physicians responded that they would
be likely to recommend RCT participation to a woman carrying a breast cancer
susceptibility mutation. Oncologists were the most likely to recommend an RCT.
Although the results of nonrandomized trials may be difficult to interpret
because of such issues as selection bias. Greater feasibility combined with fewer
ethical concerns make nonrandomized trials a more viable alternative to
randomized trials for evaluation of preventive interventions for breast and
ovarian cancer when prophylactic surgery is one of the treatments being
evaluated.
PMID- 10787221
TI - Lipid management and control of other coronary risk factors in the postmenopausal
woman.
AB - This review identifies coronary heart disease (CHD) as the leading cause of
mortality among postmenopausal women and highlights the well-documented problem
of underrecognition and undertreatment of women who are at risk for or who
already have CHD. This undertreatment encompasses both preventive care (i.e.,
drug treatment for lipid management) and more invasive treatments (e.g.,
revascularization procedures). Preventive interventions to reduce dyslipidemia
and control other coronary risk factors can lessen CHD mortality and morbidity in
the postmenopausal woman.
PMID- 10787222
TI - Women's health and the environment: innovations in science and policy.
AB - Current scientific findings indicate that environmental factors affect women's
health. Specifically, evidence has accumulated on the effects of the environment
on reproductive health, cancer, injury, respiratory problems, autoimmune
diseases, and other health problems. To review the current state of the science
and policies related to women's health and the environment, the Federal
Interagency Working Group on Women's Health and the Environment of the Department
of Health and Human Services and the Society for Women's Health Research jointly
sponsored a conference in 1998 entitled Women's Health and the Environment:
Innovations in Science and Policy. The aim of the conference was to provide a
forum for scientists to share recent findings, promising avenues of research,
methodological barriers, and data gaps about women's susceptibility to
environmental agents. The conference generated 22 recommendations for policy, 17
recommendations for communication and training, and 48 recommendations for
research to be considered by the federal government. The purpose of this review
is to bring to the attention of the scientific community and policymakers the
breadth of the women's health implications associated with environmental factors
by highlighting key research findings presented at the conference. This review
summarizes the current status of science in women's health, it describes relevant
activities by the federal government, and it suggests recommendations for future
research and policy initiatives in the context of women's health and the
environment.
PMID- 10787223
TI - Identification of premature ovarian failure patients with underlying
autoimmunity.
AB - Although known causes of premature ovarian failure (POF) include X chromosome
deletions, radiation and chemotherapy, and genetic defects of the gonadotropin
hormones or receptors, at least one third to one half of cases remain idiopathic.
A significant proportion of patients with apparently idiopathic POF have some
evidence for an autoimmune etiology. However, the only gold standard for
detecting autoimmune causes of immune ovarian destruction has been invasive
ovarian biopsy. Serum antibodies to ovarian and other self-tissue have been
described in up to one third of women with POF, but the tests are not well
standardized, not well correlated with ovarian histology, and highly variable.
Recently, specific defects of expression of cell surface markers on peripheral
blood lymphocytes have been shown to identify, in population-based studies,
individuals destined to develop autoimmune pancreatic destruction and type I
diabetes mellitus, even before any other evidence of autoimmunity. We, therefore,
sought to test the ability of cell surface marker expression in women with POF to
identify autoimmune defects. Seventeen women with POF, 11 of whom had positive
antibody titers to ovary, thyroid, or antinuclear antibody, were studied on at
least two occasions and compared in blinded fashion with normal controls and
patients with autoimmune type I diabetes mellitus. The most useful marker for
identifying autoimmunity was the surface density of conformationally correct HLA
class I molecules on macrophages, a structure essential for T cell education.
Using this marker, 7 of the 9 patients with autoantibodies and 3 of the 8
patients without autoantibodies were identified as having evidence of a defect in
self-antigen presentation similar to that of type I diabetics (chi-square, p =
0.03). Subsequent testing identified antismooth muscle antibodies in 1 of the
women with a defect of HLA class I molecules but no previously identified
autoimmunity. In addition, there were increased numbers of CD8 T cells in both
autoimmune POF and insulin-dependent diabetes mellitus (IDDM) patients. Exclusive
to POF patients was a statistically significant increase in CD8 density on T
cells. This was most prominent in POF patients with an underlying autoimmune
etiology. These data further support a role for autoimmunity in POF patients and
suggest that the further development of cell surface markers in combination with
other diagnostic tests could result in diagnosis before the development of
complete ovarian failure. The possibility for disease-specific therapy to prevent
further autoimmune ovarian damage in selected POF patients is also envisioned.
PMID- 10787224
TI - The use of abusable prescription drugs: the role of gender.
AB - It is well documented that women face greater medical exposure to psychotropic
drugs than do men, but little research examines whether women also have increased
use of prescription drugs with abuse potential. The objectives were to examine
gender differences in the use of abusable prescription drugs and to assess how
use varies by gender and if patterns of use vary across therapeutic drug classes.
With data from the 1987 National Medical Expenditures Survey (NMES), logistic
regression analysis is used to model the influence of gender and other
sociodemographic and diagnostic variables on the probability of drug use. Women
are 48% more likely than men to use any abusable prescription drug, controlling
for demographics, health status, economic status, and diagnosis. Additional
analyses reveal that being female is a statistically significant predictor of
anxiolytic and narcotic analgesic use but not of sedative-hypnotic or stimulant
use. Marital status, age, urbanicity, employment status, and having a regular
source of care explain gender differences in the use of abusable prescription
drugs. Both healthcare and substance abuse treatment providers should be
cognizant that women may have greater exposure to these potent prescription
medicines.
PMID- 10787225
TI - Early normal menstrual cycle pattern and the development of uterine leiomyomas.
AB - It is unclear if women who develop uterine leiomyomas have had menstrual
regularity or irregularity in their reproductive life. This case-control study
examines the recalled menstrual cycle patterns throughout the reproductive life
among women requiring hysterectomy for myomas. One hundred twenty-two women with
myomas and 244 age-matched healthy controls without myomas were enrolled in
Japan. The incidence of normal menstrual cycle pattern in their teens among
patients with myoma was significantly higher than that among healthy controls (p
< 0.01). The subset results for parous women were the same as those for all
subjects. The size of the uterus in myoma patients with teenage menstrual
regularity was not larger than in those with teenage menstrual irregularity.
Women who developed myomas later in life tended to have early normal menstrual
cycle pattern. Early menstrual regularity may enhance leiomyoma growth in early
reproductive life.
PMID- 10787226
TI - Tubal sterilization and use of an IUD and risk of cervical cancer.
AB - The relationship of tubal sterilization and use of an intrauterine device (IUD)
to the risk of invasive squamous cell cervical cancer was evaluated in a case
control study carried out in Shandong, China, from 1989 to 1991. Patients (cases)
were 272 women aged 30-77 years with newly diagnosed invasive squamous cell
cervical cancer in Shandong Province Tumor Hospital. Controls were 893 randomly
selected screened women matched to the cases by age (within 2 years) and county.
A decrease in risk was observed in uses of an IUD, especially in long-term users
under age 33. A nonsignificant decrease in risk in women under age 33 who had had
a tubal ligation was also observed, especially in the first 10 years since the
procedure. Tubal ligation and IUD insertion and removal provide opportunities to
screen women for cervical cancer and reduce the risk of invasive disease.
PMID- 10787227
TI - Breast self-examination in women in two primary care settings: an evaluation of
the impact of insurance status.
AB - Breast cancer is one of the most common cancers diagnosed among women in the
United States. Screening tools available for breast cancer detection include
breast self-examination (BSE), clinical breast examination, and mammography.
Various studies have indicated that women may inconsistently perform BSE. This
investigation evaluated the potential impact of insurance status on BSE. Women
with health insurance receiving primary healthcare at a health maintenance
organization (HMO) and women without health insurance receiving primary
healthcare at a free clinic completed anonymous questionnaires that obtained
information about the frequency of BSE performance, whether instruction was given
about performing BSE, age at learning BSE, and confidence in performing BSE. One
hundred fifty-five (82%) of 200 questionnaires at the HMO and 92 (92%) of 100
questionnaires at the free clinic were completed. Thirty-five percent of women
(32% at the HMO, 39% at the free clinic) reported performing BSE. There were no
significant differences in the rate of monthly BSE, receiving instruction about
performing BSE, age at learning BSE, or confidence in performing BSE in women at
the HMO and free clinic. Insurance status did not affect BSE. However, further
study is needed to evaluate factors that potentially influence performance of BSE
and could encourage compliance with BSE recommendations.
PMID- 10787228
TI - Treatment of premenstrual syndrome with a phytopharmaceutical formulation
containing Vitex agnus castus.
AB - A multicentric noninterventional trial (open study without control) to
investigate the efficacy and tolerance of a drug in a large number of patients
under routine medical conditions was performed for a new solid preparation from
an extract of the fruit of Vitex agnus castus (VAC, Vitex, chaste tree,
Chasteberry) in 1634 patients suffering from premenstrual syndrome (PMS). A
specific questionnaire was developed for determining the effect of Vitex on
psychic and somatic complaints, on the four characteristic PMS symptom complexes
depression, anxiety, craving, and hyperhydration (DACH), and on single groups of
symptoms. After a treatment period of three menstrual cycles 93% of patients
reported a decrease in the number of symptoms or even cessation of PMS
complaints. To a certain extent, this effect was observed within all symptom
complexes and correlated with the global assessment of therapeutic efficacy.
Whereas 85% of physicians rated it as good or very good, 81% of patients assessed
their status after treatment as very much or much better. Analysis of frequency
and severity of mastodynia as the predominant symptom revealed that complaints
still present after 3 months of therapy were mostly less severe. Ninety-four
percent of patients assessed the tolerance of Vitex treatment as good or very
good. Adverse drug reactions were suspected by physicians in 1.2% of patients,
but there were no serious adverse drug reactions. Hence, the risk/benefit ratio
of the new Vitex preparation can be rated as very good, with significant efficacy
for all aspects of the multifaceted and inhomogeneous clinical picture of PMS,
with a safety profile comparable to other Vitex preparations.
PMID- 10787229
TI - Resting energy expenditure in asymptomatic HIV-infected females.
AB - The purpose of this study was to investigate whether resting energy expenditure
(REE) is elevated in early, asymptomatic human immunodeficiency virus (HIV)
infected females and to study the contribution of a cytokine, tumor necrosis
factor-alpha (TNF-alpha), to hypermetabolism. Cross-sectional comparison of REE
in asymptomatic HIV+ females and a control group matched for age, body mass index
(BMI), and fat-free mass (FFM). Twenty-six females aged 35 +/- 7 years (10 HIV+
[mean CD4+ T cell count 636/mm3] and 16 healthy controls) participated in this
study. REE was measured by indirect calorimeter using a Deltatrac ventilated hood
with a continuous rate of 40 L/min for 30 minutes after a 40-minute equilibrium
period. All tests were performed after a 12-hour overnight fast. Twenty-four-hour
urinary nitrogen was calculated to correct for respiratory quotient. Body
composition was measured by bioelectrical impedance (BioAnalogics, Beaverton,
OR). TNF-alpha was measured by ELISA (R & D Systems, Minneapolis, MN). Absolute
REE was 17% higher (1755 kcal/kg +/- 410 versus 1497 kcal/kg +/- 197) in the HIV+
group compared with the control group (p < 0.05). REE remained significantly
higher in the HIV+ group when REE was adjusted for body composition differences
(p = 0.04). Results revealed a 23% higher level of TNF-alpha in the HIV+ subjects
(p < 0.01); however, only a weak correlation existed between TNF-alpha and REE (r
= .352). This study documented that hypermetabolism and elevated TNF-alpha exist
in HIV+ females in the early stages of disease.
PMID- 10787230
TI - Infertility.
PMID- 10787231
TI - Integrating cosmetic dentistry into the general dental practice. Interview by
Phillip Bonner, DDS.
PMID- 10787232
TI - The mechanism of coupling: a role for the vasculature.
PMID- 10787233
TI - XVI Annual Meeting of the Argentine Association of Bone and Mineral Metabolism
(AAOMM). October 28-29, 1999. Abstracts.
PMID- 10787234
TI - Bone ultrasonometry in Polish men and women.
PMID- 10787235
TI - Mycophenolate mofetil may induce apoptosis in duodenal villi.
PMID- 10787236
TI - Cause of hypercalciuria in X-linked chloride channel gene mutations.
PMID- 10787237
TI - Familial crescentic glomerulonephritis.
PMID- 10787238
TI - Notice of plagiarized text.
PMID- 10787239
TI - Are Mpl glycosylation defects in polycythemia vera secondary to artifactual
hypoglycemia?
PMID- 10787240
TI - HFE polymorphism and accurate diagnosis of C282Y hereditary hemochromatosis
carriers.
PMID- 10787241
TI - Immunoglobulin V genes and CD38 expression in CLL.
PMID- 10787242
TI - Blair demands reform of the NHS.
PMID- 10787244
TI - UK government wants GMC to be given stronger powers.
PMID- 10787243
TI - NICE issues guidelines on wisdom teeth. National Institute for Clinical
Excellence.
PMID- 10787245
TI - NHS bill for negligence set to soar again.
PMID- 10787246
TI - Spain faces massive decline in population.
PMID- 10787247
TI - NHS board appointments criticised.
PMID- 10787248
TI - Study explores Internet as a tool for care of diabetic patients.
PMID- 10787249
TI - More services needed for bereaved children.
PMID- 10787250
TI - Mrs Clinton aims to reduce psychoactive drugs in young children.
PMID- 10787251
TI - Twenty countries pledge to wipe out TB.
PMID- 10787253
TI - Supreme Court rules that FDA cannot regulate tobacco industry.
PMID- 10787252
TI - Australia to consider a class action against tobacco industry.
PMID- 10787254
TI - Surrogacy should pay.
PMID- 10787255
TI - Recommendations for using MMR vaccine in children allergic to eggs.
PMID- 10787256
TI - Future directions for geriatric medicine. More geriatricians will be needed to
satisfy increasing demand in community.
PMID- 10787257
TI - Unexpected beneficial effects of measles immunisation. Other conditions with
reduced mortality could have been specified.
PMID- 10787258
TI - Unexpected beneficial effects of measles immunization. Socioeconomic confounding
may also play a part.
PMID- 10787259
TI - Unexpected beneficial effects of measles immunisation. Number of squint
operations has decreased.
PMID- 10787260
TI - Unexpected beneficial effects of measles immunisation. Who brought measles?
PMID- 10787261
TI - Making decisions about screening for ovarian cancer. Mass screening may not prove
to be sound public health policy.
PMID- 10787262
TI - 3rd Annual Meeting of the Hungarian STD Society and the 4th Alpe-Adria-Danube STD
Workshop. Budapest, Hungary, 12-14 November 1998. Abstracts.
PMID- 10787264
TI - Introduction to this special issue on neurourology. Urinary incontinence.
PMID- 10787263
TI - Urinary incontinence: pathophysiology, diagnosis and treatment in clinical (neuro
)urological practice of patients with Chronic Impairment of Voiding and
Continence Activities (CIVCA)
PMID- 10787265
TI - Report of the Society for Pediatric Anesthesia 13th annual meeting.
PMID- 10787267
TI - Don't rely on the surgical airway: a case of impossible tracheostomy.
PMID- 10787266
TI - Clonidine in paediatric anaesthesia.
PMID- 10787268
TI - Lumbar epidurals via the midline approach.
PMID- 10787269
TI - An unusual cause of difficult intubation.
PMID- 10787270
TI - Heart block following propofol in a child.
PMID- 10787271
TI - A bougie for a 2.5mm tracheal tube.
PMID- 10787272
TI - Sevoflurane use in Tetralogy of Fallot: is it the best choice?
PMID- 10787273
TI - Estrogen and progesterone: receptors and ligands in the next millennium.
Proceedings of a course at the annual meeting of the Society for Gynecologic
Investigation. March 10, 1999.
PMID- 10787274
TI - The AAGL classification system for laparoscopic hysterectomy. Classification
committee of the American Association of Gynecologic Laparoscopists.
PMID- 10787276
TI - Proceedings of the 3rd International Meeting on Current Topics in Breast Cancer
Research: Cell Death and Breast Cancer. Cambridge, United Kingdom, September
1998.
PMID- 10787275
TI - Re: "The effects of cognitive rehabilitation on outcomes for persons with
traumatic brain injury: a systematic review".
PMID- 10787277
TI - Proceedings of the 2nd International Conference on Therapies for Viral Hepatitis.
Kona, Hawaii, USA. 15-19 December 1997.
PMID- 10787278
TI - Who needs needs?
PMID- 10787279
TI - Definition of arterial compliance. Re: Hardt et al., "Aortic pressure-diameter
relationship assessed by intravascular ultrasound: experimental validation in
dogs.".
PMID- 10787280
TI - Deaths after living related liver transplantation.
PMID- 10787281
TI - Donor safety in living donor liver transplantation.
PMID- 10787282
TI - "I shall please".
PMID- 10787283
TI - [Euphoria and setbacks--early radioactive cancer treatment].
PMID- 10787284
TI - [Elevated values of creatine kinase].
PMID- 10787285
TI - [Urticaria factitia].
PMID- 10787286
TI - Oral Chemotherapy: Past, Present and Future Directions. Proceedings of a
conference. Cancun, Mexico, February 26-28, 1998.
PMID- 10787287
TI - Photoparoxysmal response and the assessment of seizure control.
PMID- 10787288
TI - Sperm quality and FSH therapy?
PMID- 10787289
TI - Does preimplantation genetic diagnosis (PGD) need a new name?
PMID- 10787290
TI - Selection of summary measures for ART?
PMID- 10787291
TI - The selection of summary measures for ART outcome data-"reveal codes".
PMID- 10787292
TI - Blastocyst transfer for couples with multiple IVF failures?
PMID- 10787293
TI - Clarifications and relationships between estrogen and prostaglandins.
PMID- 10787294
TI - Proceedings of the Symposium Current Status of Sexing Mammalian Sperm.
Maastricht, The Netherlands, January 8, 2000.
PMID- 10787295
TI - R. Yanagimachi, recipient of the 2000 Embryo Transfer Pioneer Award.
PMID- 10787296
TI - Proceedings of the annual conference of the International Embryo Transfer
Society. Maastricht, The Netherlands, January 9-11, 2000.
PMID- 10787297
TI - Colorectal neoplasm detection using virtual colonoscopy: a feasibility study.
PMID- 10787298
TI - Assessment of innate ability and skills for endoscopic manipulations by the
advanced Dundee endoscopic psychomotor tester: predictive and concurrent
validity.
PMID- 10787299
TI - Early administration of somatostatin and efficacy of sclerotherapy in acute
oesophageal variceal bleeds: the European Acute Bleeding Oesophageal Variceal
Episodes (ABOVE) randomised trial.
PMID- 10787301
TI - Focus on posttraumatic stress disorder. 4th meeting of the International
Consensus Group on Depression and Anxiety. Montecatini, Italy, April 1999.
PMID- 10787300
TI - Implications of left-to-right lung ventilation heterogeneity.
PMID- 10787302
TI - New doors to open...and so many!
PMID- 10787303
TI - Avoid unfavorable consequences: dextromethorpan can bring about a false-positive
phencyclidine urine drug screen.
PMID- 10787304
TI - Intravenous saline has no effect on blood ethanol clearance.
PMID- 10787305
TI - Familial Creutzfeldt-Jakob disease with D178N-129M mutation of PRNP presenting as
cerebellar ataxia without insomnia.
PMID- 10787306
TI - Postmalaria neurological syndrome: a case of acute disseminated
encephalomyelitis?
PMID- 10787307
TI - Trigeminal sensory neuropathy: anatomico-physiological correction.
PMID- 10787308
TI - Unilateral eyelid retraction.
PMID- 10787309
TI - Behcet's syndrome may present with partial seizures.
PMID- 10787310
TI - Morphological abnormalities of hepatic mitochondria in two patients with
spinocerebellar ataxia type 7.
PMID- 10787311
TI - Cervical syringomyelia at the C7-C8 level presenting with bilateral scapular
winging.
PMID- 10787312
TI - Focal neuropathy associated with cutaneous necrosis at the site of interferon
beta injection for multiple sclerosis.
PMID- 10787313
TI - Treatment with intravenous prednisone and immunoglobin in a case of progressive
encephalomyelitis with rigidity.
PMID- 10787315
TI - Predicting survival using simple clinical variables: a case study in traumatic
brain injury.
PMID- 10787314
TI - Benign multiple sclerosis? Clinical course, long term follow up, and assessment
of prognostic factors.
PMID- 10787316
TI - Distinctions between critical illness polyneuropathy and axonal Guillain-Barre
syndrome.
PMID- 10787317
TI - New hope for patients with pure lower motor neurons syndromes.
PMID- 10787318
TI - International Symposium on Glutamate. Proceedings of a symposium held October 12
14, 1998 in Bergamo, Italy.
PMID- 10787319
TI - Ciliary body detachment caused by capsule contraction.
PMID- 10787320
TI - Inflammation and blood-aqueous barrier disruption.
PMID- 10787322
TI - Piggyback intraocular lenses.
PMID- 10787321
TI - Astigmatic corneas--oblate and prolate meridians.
PMID- 10787323
TI - Surgical treatment of pellucid marginal degeneration associated with cataract.
PMID- 10787324
TI - When to perform LASIK in contact lens wearers.
PMID- 10787325
TI - Consultation section. Cataract surgical problem.
PMID- 10787326
TI - [Facial palsy, enhancement of cranial nerves and Lyme disease].
AB - Lyme disease involves multiple organ systems including in 10-15% of cases, the
nervous system. Cranial neuropathies are observed in the second stage of the
disease. The facial nerve is the most frequently affected nerve (20-30%). Facial
nerve enhancement may be associated with cochleovestibular nerve abnormalities
and can mimick an intracanalicular pseudomass. We present post-gadolinium
enhancement of multiple cranial nerves associated to an intracanicular
enhancement illustrated in a patient referred for a facial nerve palsy and
presenting a Lyme disease. We discuss the differential diagnosis.
PMID- 10787327
TI - Effect of calcium chromate dust, influenza virus, and 100 R whole-body x
radiation on lung tumor incidence in mice.
PMID- 10787328
TI - Medical professionalism--focusing on the real issues.
PMID- 10787329
TI - Medical professionalism in society.
PMID- 10787330
TI - Medical professionalism in society.
PMID- 10787331
TI - Medical professionalism in society.
PMID- 10787332
TI - Efavirenz in HIV infection.
PMID- 10787333
TI - Prevention of sudden death in patients with coronary artery disease.
PMID- 10787334
TI - Prevention of sudden death in patients with coronary artery disease.
PMID- 10787335
TI - Treatment of allergic asthma with monoclonal anti-IgE antibody.
PMID- 10787336
TI - Disorders of iron metabolism.
PMID- 10787337
TI - Disorders of iron metabolism.
PMID- 10787338
TI - Disorders of iron metabolism.
PMID- 10787339
TI - Epoetin for severe anemia in hepatoerythropoietic porphyria.
PMID- 10787340
TI - German researchers seek legal backing for stem cell work.
PMID- 10787341
TI - Giant tortoises come home.
PMID- 10787342
TI - Japan sets tissue donor guidelines.
PMID- 10787343
TI - US geneticists encouraged to play by the book.
PMID- 10787344
TI - Varmus tells Congress to grasp thorny policy issues.
PMID- 10787345
TI - Monsanto makes rice genome public.
PMID- 10787346
TI - Hypothalamic haemorrhage and thalamus degeneration in a case of Nasu-Hakola
disease with hallucinatory symptoms and central hypothermia.
PMID- 10787347
TI - Anterior sacrospinous vaginal vault suspension for prolapse.
PMID- 10787348
TI - Combination antiretroviral therapy in human immunodeficiency virus-infected
pregnant women.
PMID- 10787349
TI - Cervical ripening and labor induction with a controlled-release dinoprostone
vaginal insert.
PMID- 10787350
TI - Index of suspicion. Case 2. Cystic hygroma.
PMID- 10787351
TI - Index of suspicion. Case 3. Congenital diaphragmatic hernia.
PMID- 10787352
TI - [Risk of stillbirths and paternal occupational exposure to ionizing radiation].
PMID- 10787353
TI - [DEA research summaries on Epidemiology and Public Health].
PMID- 10787354
TI - Once more: Light's criteria revisited.
PMID- 10787355
TI - Lignocaine for topical anesthesia in fiberoptic bronchoscopy.
PMID- 10787356
TI - Transfusion of buffy coat-depleted blood components and risk of postoperative
infection in orthopedic patients.
PMID- 10787357
TI - Proceedings of the 5th International Veterinary Immunology Symposium. Ludhiana,
India, November 8-13, 1998.
PMID- 10787358
TI - Sporadic microsatellite instability is specific to neoplastic and preneoplastic
endometrial tissues.
AB - Microsatellite instability is a frequent (13%-24%) finding in sporadic
endometrial adenocarcinoma and its precursor lesions, but most studies are
limited to patients who already have malignant or premalignant endometrial
disease. We performed retrospective testing for microsatellite instability in
women in whom cancers showing microsatellite instability developed later and
prospective testing in randomly selected normal and anovular endometrial biopsy
specimens. Microsatellite instability in cancer-bearing biopsy specimens
accurately reflected that seen in matched malignant tissues obtained at
hysterectomy. In 1 patient, microsatellite instability developed in a scanty
sample of fragmented endometrial tissues 7 years before the onset of endometrial
cancer. Prospective testing for microsatellite instability in the endometria of
women unselected for subsequent appearance of endometrial cancer showed a very
low rate of microsatellite instability. Only 1 endometrial specimen showing
microsatellite instability was found among 75 anovulatory endometrial specimens,
and none were found in 377 normal endometrial specimens and 46 polyps examined.
Microsatellite instability may precede the onset of histologically diagnosed
carcinoma but is rare in randomly sampled histologically normal endometrial
tissues.
PMID- 10787359
TI - C-terminal sequence analysis of peptides and proteins using carboxypeptidases and
mass spectrometry after derivatization of Lys and Cys residues.
AB - C-Terminal sequence analysis of peptides and proteins using carboxypeptidase
digestion in combination with matrix-assisted laser desorption/ionization mass
spectrometry (MALDI-MS) is convenient for protein and peptide characterization.
After a short digestion, a sequence up to 20 residues can be identified, but the
total number depends on the individual sequence. Due to the accuracy limits of
the MALDI time-of-flight arrangement, the assignment of several residues with
close mass values, including Lys/Glx, may remain ambiguous. We have used
derivatization of lysine residues by guanidination to overcome the problem of Lys
identification. The reaction is rapid and specific and results in full
derivatization. In the case of Cys-containing peptides, problems arise from the
fact that carboxypeptidases Y and P do not cleave peptides that contain
nonderivatized cystine, cysteic acid, or (carboxymethyl)cysteine. Successful
identification of Cys residues within the sequence is instead achieved by
conversion of Cys to 4-thialaminine by (trimethylamino)-ethylation. The two
derivatizations of Lys and Cys side chains provide opportunities for proton
attachment and therefore facilitate the analysis by MALDI-MS. This C-terminal
sequence analysis method is also useful for large proteins after fragmentation
with specific enzymes.
PMID- 10787360
TI - National Highway Traffic Safety Administration (NHTSA) notes. Commentary: Drugged
driving--different spin on an old problem.
PMID- 10787361
TI - Postmenopausal hormone therapy increases risk for venous thromboembolic disease.
The Heart and Estrogen/progestin Replacement Study.
AB - BACKGROUND: Oral contraceptive use increases risk for venous thromboembolism, but
data on the effect of postmenopausal hormone therapy are limited. OBJECTIVE: To
determine the effect of therapy with estrogen plus progestin on risk for venous
thromboembolic events in postmenopausal women. DESIGN: Randomized, double-blind,
placebo-controlled trial. SETTING: 20 clinical centers in the United States.
PARTICIPANTS: 2763 postmenopausal women younger than 80 years of age (mean age,
67 years) who had coronary heart disease but no previous venous thromboembolism
and had not had a hysterectomy. INTERVENTION: Conjugated equine estrogens, 0.625
mg, plus medroxyprogesterone acetate, 2.5 mg, in one tablet (n = 1380) or placebo
that was identical in appearance (n = 1383). MEASUREMENTS: Documented deep venous
thrombosis or pulmonary embolism. RESULTS: During an average of 4.1 years of
follow-up, 34 women in the hormone therapy group and 13 in the placebo group
experienced venous thromboembolic events (relative hazard, 2.7 [95% CI, 1.4 to
5.0] [P = 0.003]; excess risk, 3.9 per 1000 woman-years [CI, 1.4 to 6.4 per 1000
woman-years]; number needed to treat for harm, 256 [CI, 157 to 692]). In
multivariate analysis, the risk for venous thromboembolism was increased among
women who had lower-extremity fractures (relative hazard, 18.1 [CI, 5.4 to 60.4])
or cancer (relative hazard, 3.9 [CI, 1.6 to 9.4]) and for 90 days after inpatient
surgery (relative hazard, 4.9 [CI, 2.4 to 9.8]) or nonsurgical hospitalization
(relative hazard, 5.7 [CI, 3.0 to 10.8]). Risk was decreased with aspirin
(relative hazard, 0.5 [CI, 0.2 to 0.8]) or statin use (relative hazard, 0.5 [CI,
0.2 to 0.9]). CONCLUSIONS: Postmenopausal therapy with estrogen plus progestin
increases risk for venous thromboembolism in women with coronary heart disease.
This risk should be considered when the risks and benefits of therapy are being
weighed.
PMID- 10787362
TI - Screening for cervical and breast cancer: is obesity an unrecognized barrier to
preventive care?
AB - BACKGROUND: Compared with thinner women, obese women have higher mortality rates
for breast and cervical cancer. In addition, obesity leads to adverse social and
psychological consequences. Whether obesity limits access to screening for breast
and cervical cancer is unclear. OBJECTIVE: To examine the relation between
obesity and screening with Papanicolaou (Pap) smears and mammography. DESIGN:
Population-based survey. SETTING: United States. PARTICIPANTS: 11 435 women who
responded to the "Year 2000 Supplement" of the 1994 National Health Interview
Survey. MEASUREMENTS: Screening with Pap smears and mammography was assessed by
questionnaire. RESULTS: In women 18 to 75 years of age who had not previously
undergone hysterectomy (n = 8394), fewer overweight women (78%) and obese women
(78%) than normal-weight women (84%) had had Pap smears in the previous 3 years
(P < 0.001). After adjustment for sociodemographic information, insurance and
access to care, illness burden, and provider specialty, rate differences for
screening with Pap smears were still seen among overweight (-3.5% [95% CI, -5.9%
to -1.1%]) and obese women (-5.3% [CI, -8.0% to -2.6%]). In women 50 to 75 years
of age (n = 3502), fewer overweight women (64%) and obese women (62%) than normal
weight women (68%) had had mammography in the previous 2 years (P < 0.002). After
adjustment, rate differences were -2.8% (CI, -6.7% to 0.9%) for overweight women
and -5.4% (CI, -10.8% to -0.1%) for obese women. CONCLUSIONS: Overweight and
obese women were less likely to be screened for cervical and breast cancer with
Pap smears and mammography, even after adjustment for other known barriers to
care. Because overweight and obese women have higher mortality rates for cervical
and breast cancer, they should be targeted for increased screening.
PMID- 10787363
TI - Determining the quality of breast cancer care: do tumor registries measure up?
AB - BACKGROUND: Hospital tumor registries, which provide data that inform health
services research and cancer control policies, may be a source of information
about quality of cancer care. However, the accuracy of data from such registries
is unknown. OBJECTIVE: To determine the accuracy of tumor registry data by
comparing it with data collected from numerous sources for a breast cancer
quality improvement project. DESIGN: Retrospective cohort study. SETTING: Three
teaching hospitals with tumor registries in the New York metropolitan area that
had participated in the quality improvement project. PATIENTS: All women with
newly diagnosed primary breast cancer (stage I or stage II) who were surgically
treated at the study hospitals between 1 November 1994 and 31 August 1996.
MEASUREMENTS: Sensitivity and specificity were calculated, and data from the
quality improvement project were used as the gold standard. RESULTS: The tumor
registries and the quality improvement project had similar information on tumor
stage and surgery type. Sensitivity ranged from 0.91 to 0.96, and specificity
ranged from 0.93 to 0.97. When both sources were used to calculate quality
measures, the overall rate of radiation therapy after breast-conserving surgery
was 80% in the quality improvement project and 48% in the tumor registries
(sensitivity, 0.58; specificity, 0.94). For receipt of adjuvant systemic
treatment, the rate was 78% in the quality improvement project and 22% in the
tumor registries (sensitivity, 0.27; specificity, 0.97). CONCLUSIONS: Data from
tumor registries provide accurate measures for hospital-based surgical treatments
but not for outpatient treatments. Unverified tumor registry data should not be
used to measure quality of care.
PMID- 10787364
TI - Hyponatremia, cerebral edema, and noncardiogenic pulmonary edema in marathon
runners.
AB - BACKGROUND: Noncardiogenic pulmonary edema is often associated with increased
intracranial pressure and can be the initial manifestation of hyponatremic
encephalopathy. Marathon runners tend to develop conditions that lead to
hyponatremia. OBJECTIVE: To describe the development and treatment of
noncardiogenic pulmonary edema in marathon runners that was associated with
hyponatremic encephalopathy. DESIGN: Case series. SETTING: One university
hospital and two community hospitals. PATIENTS: Seven healthy marathon runners
who had a history of nonsteroidal anti-inflammatory drug use. The runners
collapsed after competing in a marathon and were hospitalized with pulmonary
edema. MEASUREMENTS: Plasma sodium levels, chest radiograph, electrocardiogram,
cardiac enzyme levels, and magnetic resonance imaging or computed tomographic
scans of the brain. RESULTS: Patients had nausea, emesis, and obtundation. The
mean (+/-SD) plasma sodium level was 121 +/- 3 mmol/L, and oxygen saturation was
less than 70%. Electrocardiograms and echocardiograms were normal. Chest
radiographs showed pulmonary edema with a normal heart. Creatine phosphokinase-MB
bands, troponin levels, and pulmonary wedge pressure were not elevated. Scanning
of the brain showed cerebral edema. All patients were intubated and mechanically
ventilated. Treatment with intravenous NaCl, 514 mmol/L, increased plasma sodium
levels by 10 mmol/L in 12 hours. Pulmonary and cerebral edema resolved as the
sodium level increased. One patient had unsuspected hyponatremic encephalopathy
and died of cardiopulmonary arrest caused by brainstem herniation. All six
treated patients recovered and were well after 1 year of follow-up. CONCLUSIONS:
In healthy marathon runners, noncardiogenic pulmonary edema can be associated
with hyponatremic encephalopathy. The condition may be fatal if undiagnosed and
can be successfully treated with hypertonic NaCl.
PMID- 10787365
TI - Claims of equivalence in medical research: are they supported by the evidence?
AB - BACKGROUND: Most clinical studies are done to show comparative superiority, but
many reports now claim equivalence between the investigated entities. These
assertions may not always be supported by the methods used and the results
obtained. PURPOSE: To assess the justification and support for claims of clinical
or therapeutic equivalence in medical journals. DATA SOURCES: A search of MEDLINE
for articles published from 1992 through 1996. STUDY SELECTION: From 1209
citations that contained the word equivalence in the title or abstract or
contained the Medical Subject Heading therapeutic equivalency, we excluded 1121
studies reporting nonoriginal research, purely laboratory or other nonhuman
research, and studies in which equivalence was not the main claim. The remaining
88 eligible papers were evaluated for five methodologic attributes. DATA
SYNTHESIS: Only 45 (51%) of the 88 reports were specifically aimed at studying
equivalence; the others either tried to show superiority or did not state a
research aim. The quantitative distinctions regarded as "equivalent" ranged from
0% to 21% for direct increments and from 0% to 76% for proportionate differences.
An equivalence boundary was set and confirmed with an appropriate statistical
test in only 23% of reports. In 67% of reports, equivalence was declared after a
failed test for comparative superiority, and in 10%, the claim of equivalence was
not statistically evaluated. The sample size needed to confirm results had been
calculated in advance for only 33% of reports. Sample size was 20 patients per
group or fewer in 25% of reports. CONCLUSIONS: Many studies of clinical
equivalence do not set boundaries for equivalence. Claims of "difference" or
"similarity" are often made not by thoughtful examination of the data but by
tests of statistical significance that are often misapplied or accompanied by
inadequate sample sizes. These methodologic flaws can lead to false claims,
inconsistencies, and harm to patients.
PMID- 10787366
TI - Chronic hepatitis B virus infection: treatment strategies for the next
millennium.
AB - Chronic hepatitis B virus (HBV) infection is a leading cause of cirrhosis and
hepatocellular carcinoma worldwide. Its prevalence approaches 10% in hyperendemic
areas, such as southeast Asia, China, and Africa. Although chronic HBV infection
is seen less frequently in North America and Europe, an estimated 1.25 million
persons in the United States are infected. In the past decade, revolutionary
strides have been made toward the treatment of chronic HBV infection. Interferon
alpha was once the only available therapy but has recently been joined by the
nucleoside analogues, the most extensively studied of which is lamivudine.
Interferon therapy continues to have a role in the treatment of a carefully
selected group of patients. Lamivudine therapy, which has less stringent
selection criteria, suppresses HBV DNA in almost all treated patients: Seventeen
percent to 33% experience loss of hepatitis B e antigen, and 53% to 56% have a
histologic response. Extended lamivudine treatment leads to the development of a
specific lamivudine-resistant virus with base-pair substitutions at the YMDD
locus of the DNA polymerase. Newer nucleoside analogues and other immunomodulator
therapies are being investigated. In the future, combination therapy with
different classes of agents may yield improved response rates and delay the
development of resistance.
PMID- 10787367
TI - What is the right cancer screening rate?
PMID- 10787368
TI - The role of bisphosphonates in multiple myeloma.
PMID- 10787369
TI - Pharmacologic treatment of acute major depression and dysthymia. American College
of Physicians-American Society of Internal Medicine.
PMID- 10787370
TI - A systematic review of newer pharmacotherapies for depression in adults: evidence
report summary.
AB - BACKGROUND: Depressive disorders are persistent, recurring illnesses that cause
great suffering for patients and their families. PURPOSE: To evaluate the
benefits and adverse effects of newer pharmacotherapies and herbal treatments for
depressive disorders in adults and adolescents. DATA SOURCES: English-language
and non-English-language literature from 1980 to January 1998 was identified from
a specialized registry of controlled trials, meta-analyses, and experts. STUDY
SELECTION: Randomized trials evaluating newer antidepressants (such as serotonin
reuptake inhibitors, serotonin norepinephrine reuptake inhibitors, and St. John's
wort) that reported clinical outcomes were selected. DATA EXTRACTION: Two persons
independently abstracted data that were then synthesized descriptively; some data
were pooled by using a random-effects model. DATA SYNTHESIS: Of 315 eligible
trials, most evaluated antidepressants in adults with major depression, were
conducted among outpatients, and examined acute-phase treatment. Newer
antidepressants were more effective than placebo for major depression (relative
benefit, 1.6 [95% CI, 1.5 to 1.7]) and dysthymia (relative benefit, 1.7 [CI, 1.3
to 2.3]). They were effective among older adults and primary care patients.
Efficacy did not differ among newer agents or between newer and older agents.
Hypericum (St. John's wort) was more effective than placebo for mild to moderate
depression (risk ratio, 1.9 [CI, 1.2 to 2.8]), but publication bias may have
inflated the estimate of benefit. Newer and older antidepressants did not differ
for overall discontinuation rates, but side effect profiles varied significantly.
Data were insufficient for determining the efficacy of newer antidepressants for
subsyndromal depression, depression with coexisting medical or psychiatric
illness, or depression in adolescents. CONCLUSIONS: Newer antidepressants are
clearly effective in treating depressive disorders in diverse settings. Because
of similar efficacy, both newer and older antidepressants should be considered
when making treatment decisions. Better information is urgently needed on the
efficacy of newer antidepressants in patients with nonmajor depression and in
special populations, including adolescents.
PMID- 10787371
TI - Simple gifts.